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 PARAMS ((HOST_WIDE_INT *,
61 unsigned HOST_WIDE_INT,
63 static void decode PARAMS ((HOST_WIDE_INT *,
64 unsigned HOST_WIDE_INT *,
66 static bool negate_expr_p PARAMS ((tree));
67 static tree negate_expr PARAMS ((tree));
68 static tree split_tree PARAMS ((tree, enum tree_code, tree *, tree *,
70 static tree associate_trees PARAMS ((tree, tree, enum tree_code, tree));
71 static tree int_const_binop PARAMS ((enum tree_code, tree, tree, int));
72 static tree const_binop PARAMS ((enum tree_code, tree, tree, int));
73 static hashval_t size_htab_hash PARAMS ((const void *));
74 static int size_htab_eq PARAMS ((const void *, const void *));
75 static tree fold_convert PARAMS ((tree, tree));
76 static enum tree_code invert_tree_comparison PARAMS ((enum tree_code));
77 static enum tree_code swap_tree_comparison PARAMS ((enum tree_code));
78 static int comparison_to_compcode PARAMS ((enum tree_code));
79 static enum tree_code compcode_to_comparison PARAMS ((int));
80 static int truth_value_p PARAMS ((enum tree_code));
81 static int operand_equal_for_comparison_p PARAMS ((tree, tree, tree));
82 static int twoval_comparison_p PARAMS ((tree, tree *, tree *, int *));
83 static tree eval_subst PARAMS ((tree, tree, tree, tree, tree));
84 static tree pedantic_omit_one_operand PARAMS ((tree, tree, tree));
85 static tree distribute_bit_expr PARAMS ((enum tree_code, tree, tree, tree));
86 static tree make_bit_field_ref PARAMS ((tree, tree, int, int, int));
87 static tree optimize_bit_field_compare PARAMS ((enum tree_code, tree,
89 static tree decode_field_reference PARAMS ((tree, HOST_WIDE_INT *,
91 enum machine_mode *, int *,
92 int *, tree *, tree *));
93 static int all_ones_mask_p PARAMS ((tree, int));
94 static tree sign_bit_p PARAMS ((tree, tree));
95 static int simple_operand_p PARAMS ((tree));
96 static tree range_binop PARAMS ((enum tree_code, tree, tree, int,
98 static tree make_range PARAMS ((tree, int *, tree *, tree *));
99 static tree build_range_check PARAMS ((tree, tree, int, tree, tree));
100 static int merge_ranges PARAMS ((int *, tree *, tree *, int, tree, tree,
102 static tree fold_range_test PARAMS ((tree));
103 static tree unextend PARAMS ((tree, int, int, tree));
104 static tree fold_truthop PARAMS ((enum tree_code, tree, tree, tree));
105 static tree optimize_minmax_comparison PARAMS ((tree));
106 static tree extract_muldiv PARAMS ((tree, tree, enum tree_code, tree));
107 static tree extract_muldiv_1 PARAMS ((tree, tree, enum tree_code, tree));
108 static tree strip_compound_expr PARAMS ((tree, tree));
109 static int multiple_of_p PARAMS ((tree, tree, tree));
110 static tree constant_boolean_node PARAMS ((int, tree));
111 static int count_cond PARAMS ((tree, int));
112 static tree fold_binary_op_with_conditional_arg
113 PARAMS ((enum tree_code, tree, tree, tree, int));
114 static bool fold_real_zero_addition_p PARAMS ((tree, tree, int));
115 static tree fold_mathfn_compare PARAMS ((enum built_in_function,
116 enum tree_code, tree, tree, tree));
117 static tree fold_inf_compare PARAMS ((enum tree_code, tree, tree, tree));
119 /* The following constants represent a bit based encoding of GCC's
120 comparison operators. This encoding simplifies transformations
121 on relational comparison operators, such as AND and OR. */
122 #define COMPCODE_FALSE 0
123 #define COMPCODE_LT 1
124 #define COMPCODE_EQ 2
125 #define COMPCODE_LE 3
126 #define COMPCODE_GT 4
127 #define COMPCODE_NE 5
128 #define COMPCODE_GE 6
129 #define COMPCODE_TRUE 7
131 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
132 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
133 and SUM1. Then this yields nonzero if overflow occurred during the
136 Overflow occurs if A and B have the same sign, but A and SUM differ in
137 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
139 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
141 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
142 We do that by representing the two-word integer in 4 words, with only
143 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
144 number. The value of the word is LOWPART + HIGHPART * BASE. */
147 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
148 #define HIGHPART(x) \
149 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
150 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
152 /* Unpack a two-word integer into 4 words.
153 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
154 WORDS points to the array of HOST_WIDE_INTs. */
157 encode (words, low, hi)
158 HOST_WIDE_INT *words;
159 unsigned HOST_WIDE_INT low;
162 words[0] = LOWPART (low);
163 words[1] = HIGHPART (low);
164 words[2] = LOWPART (hi);
165 words[3] = HIGHPART (hi);
168 /* Pack an array of 4 words into a two-word integer.
169 WORDS points to the array of words.
170 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
173 decode (words, low, hi)
174 HOST_WIDE_INT *words;
175 unsigned HOST_WIDE_INT *low;
178 *low = words[0] + words[1] * BASE;
179 *hi = words[2] + words[3] * BASE;
182 /* Make the integer constant T valid for its type by setting to 0 or 1 all
183 the bits in the constant that don't belong in the type.
185 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
186 nonzero, a signed overflow has already occurred in calculating T, so
190 force_fit_type (t, overflow)
194 unsigned HOST_WIDE_INT low;
198 if (TREE_CODE (t) == REAL_CST)
200 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
201 Consider doing it via real_convert now. */
205 else if (TREE_CODE (t) != INTEGER_CST)
208 low = TREE_INT_CST_LOW (t);
209 high = TREE_INT_CST_HIGH (t);
211 if (POINTER_TYPE_P (TREE_TYPE (t)))
214 prec = TYPE_PRECISION (TREE_TYPE (t));
216 /* First clear all bits that are beyond the type's precision. */
218 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
220 else if (prec > HOST_BITS_PER_WIDE_INT)
221 TREE_INT_CST_HIGH (t)
222 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
225 TREE_INT_CST_HIGH (t) = 0;
226 if (prec < HOST_BITS_PER_WIDE_INT)
227 TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
230 /* Unsigned types do not suffer sign extension or overflow unless they
232 if (TREE_UNSIGNED (TREE_TYPE (t))
233 && ! (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
234 && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
237 /* If the value's sign bit is set, extend the sign. */
238 if (prec != 2 * HOST_BITS_PER_WIDE_INT
239 && (prec > HOST_BITS_PER_WIDE_INT
240 ? 0 != (TREE_INT_CST_HIGH (t)
242 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
243 : 0 != (TREE_INT_CST_LOW (t)
244 & ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
246 /* Value is negative:
247 set to 1 all the bits that are outside this type's precision. */
248 if (prec > HOST_BITS_PER_WIDE_INT)
249 TREE_INT_CST_HIGH (t)
250 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
253 TREE_INT_CST_HIGH (t) = -1;
254 if (prec < HOST_BITS_PER_WIDE_INT)
255 TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
259 /* Return nonzero if signed overflow occurred. */
261 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
265 /* Add two doubleword integers with doubleword result.
266 Each argument is given as two `HOST_WIDE_INT' pieces.
267 One argument is L1 and H1; the other, L2 and H2.
268 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
271 add_double (l1, h1, l2, h2, lv, hv)
272 unsigned HOST_WIDE_INT l1, l2;
273 HOST_WIDE_INT h1, h2;
274 unsigned HOST_WIDE_INT *lv;
277 unsigned HOST_WIDE_INT l;
281 h = h1 + h2 + (l < l1);
285 return OVERFLOW_SUM_SIGN (h1, h2, h);
288 /* Negate a doubleword integer with doubleword result.
289 Return nonzero if the operation overflows, assuming it's signed.
290 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
291 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
294 neg_double (l1, h1, lv, hv)
295 unsigned HOST_WIDE_INT l1;
297 unsigned HOST_WIDE_INT *lv;
304 return (*hv & h1) < 0;
314 /* Multiply two doubleword integers with doubleword result.
315 Return nonzero if the operation overflows, assuming it's signed.
316 Each argument is given as two `HOST_WIDE_INT' pieces.
317 One argument is L1 and H1; the other, L2 and H2.
318 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
321 mul_double (l1, h1, l2, h2, lv, hv)
322 unsigned HOST_WIDE_INT l1, l2;
323 HOST_WIDE_INT h1, h2;
324 unsigned HOST_WIDE_INT *lv;
327 HOST_WIDE_INT arg1[4];
328 HOST_WIDE_INT arg2[4];
329 HOST_WIDE_INT prod[4 * 2];
330 unsigned HOST_WIDE_INT carry;
332 unsigned HOST_WIDE_INT toplow, neglow;
333 HOST_WIDE_INT tophigh, neghigh;
335 encode (arg1, l1, h1);
336 encode (arg2, l2, h2);
338 memset ((char *) prod, 0, sizeof prod);
340 for (i = 0; i < 4; i++)
343 for (j = 0; j < 4; j++)
346 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
347 carry += arg1[i] * arg2[j];
348 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
350 prod[k] = LOWPART (carry);
351 carry = HIGHPART (carry);
356 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
358 /* Check for overflow by calculating the top half of the answer in full;
359 it should agree with the low half's sign bit. */
360 decode (prod + 4, &toplow, &tophigh);
363 neg_double (l2, h2, &neglow, &neghigh);
364 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
368 neg_double (l1, h1, &neglow, &neghigh);
369 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
371 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
374 /* Shift the doubleword integer in L1, H1 left by COUNT places
375 keeping only PREC bits of result.
376 Shift right if COUNT is negative.
377 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
378 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
381 lshift_double (l1, h1, count, prec, lv, hv, arith)
382 unsigned HOST_WIDE_INT l1;
383 HOST_WIDE_INT h1, count;
385 unsigned HOST_WIDE_INT *lv;
389 unsigned HOST_WIDE_INT signmask;
393 rshift_double (l1, h1, -count, prec, lv, hv, arith);
397 #ifdef SHIFT_COUNT_TRUNCATED
398 if (SHIFT_COUNT_TRUNCATED)
402 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
404 /* Shifting by the host word size is undefined according to the
405 ANSI standard, so we must handle this as a special case. */
409 else if (count >= HOST_BITS_PER_WIDE_INT)
411 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
416 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
417 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
421 /* Sign extend all bits that are beyond the precision. */
423 signmask = -((prec > HOST_BITS_PER_WIDE_INT
424 ? ((unsigned HOST_WIDE_INT) *hv
425 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
426 : (*lv >> (prec - 1))) & 1);
428 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
430 else if (prec >= HOST_BITS_PER_WIDE_INT)
432 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
433 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
438 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
439 *lv |= signmask << prec;
443 /* Shift the doubleword integer in L1, H1 right by COUNT places
444 keeping only PREC bits of result. COUNT must be positive.
445 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
446 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
449 rshift_double (l1, h1, count, prec, lv, hv, arith)
450 unsigned HOST_WIDE_INT l1;
451 HOST_WIDE_INT h1, count;
453 unsigned HOST_WIDE_INT *lv;
457 unsigned HOST_WIDE_INT signmask;
460 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
463 #ifdef SHIFT_COUNT_TRUNCATED
464 if (SHIFT_COUNT_TRUNCATED)
468 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
470 /* Shifting by the host word size is undefined according to the
471 ANSI standard, so we must handle this as a special case. */
475 else if (count >= HOST_BITS_PER_WIDE_INT)
478 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
482 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
484 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
487 /* Zero / sign extend all bits that are beyond the precision. */
489 if (count >= (HOST_WIDE_INT)prec)
494 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
496 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
498 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
499 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
504 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
505 *lv |= signmask << (prec - count);
509 /* Rotate the doubleword integer in L1, H1 left by COUNT places
510 keeping only PREC bits of result.
511 Rotate right if COUNT is negative.
512 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
515 lrotate_double (l1, h1, count, prec, lv, hv)
516 unsigned HOST_WIDE_INT l1;
517 HOST_WIDE_INT h1, count;
519 unsigned HOST_WIDE_INT *lv;
522 unsigned HOST_WIDE_INT s1l, s2l;
523 HOST_WIDE_INT s1h, s2h;
529 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
530 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
535 /* Rotate the doubleword integer in L1, H1 left by COUNT places
536 keeping only PREC bits of result. COUNT must be positive.
537 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
540 rrotate_double (l1, h1, count, prec, lv, hv)
541 unsigned HOST_WIDE_INT l1;
542 HOST_WIDE_INT h1, count;
544 unsigned HOST_WIDE_INT *lv;
547 unsigned HOST_WIDE_INT s1l, s2l;
548 HOST_WIDE_INT s1h, s2h;
554 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
555 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
560 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
561 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
562 CODE is a tree code for a kind of division, one of
563 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
565 It controls how the quotient is rounded to an integer.
566 Return nonzero if the operation overflows.
567 UNS nonzero says do unsigned division. */
570 div_and_round_double (code, uns,
571 lnum_orig, hnum_orig, lden_orig, hden_orig,
572 lquo, hquo, lrem, hrem)
575 unsigned HOST_WIDE_INT lnum_orig; /* num == numerator == dividend */
576 HOST_WIDE_INT hnum_orig;
577 unsigned HOST_WIDE_INT lden_orig; /* den == denominator == divisor */
578 HOST_WIDE_INT hden_orig;
579 unsigned HOST_WIDE_INT *lquo, *lrem;
580 HOST_WIDE_INT *hquo, *hrem;
583 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
584 HOST_WIDE_INT den[4], quo[4];
586 unsigned HOST_WIDE_INT work;
587 unsigned HOST_WIDE_INT carry = 0;
588 unsigned HOST_WIDE_INT lnum = lnum_orig;
589 HOST_WIDE_INT hnum = hnum_orig;
590 unsigned HOST_WIDE_INT lden = lden_orig;
591 HOST_WIDE_INT hden = hden_orig;
594 if (hden == 0 && lden == 0)
595 overflow = 1, lden = 1;
597 /* calculate quotient sign and convert operands to unsigned. */
603 /* (minimum integer) / (-1) is the only overflow case. */
604 if (neg_double (lnum, hnum, &lnum, &hnum)
605 && ((HOST_WIDE_INT) lden & hden) == -1)
611 neg_double (lden, hden, &lden, &hden);
615 if (hnum == 0 && hden == 0)
616 { /* single precision */
618 /* This unsigned division rounds toward zero. */
624 { /* trivial case: dividend < divisor */
625 /* hden != 0 already checked. */
632 memset ((char *) quo, 0, sizeof quo);
634 memset ((char *) num, 0, sizeof num); /* to zero 9th element */
635 memset ((char *) den, 0, sizeof den);
637 encode (num, lnum, hnum);
638 encode (den, lden, hden);
640 /* Special code for when the divisor < BASE. */
641 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
643 /* hnum != 0 already checked. */
644 for (i = 4 - 1; i >= 0; i--)
646 work = num[i] + carry * BASE;
647 quo[i] = work / lden;
653 /* Full double precision division,
654 with thanks to Don Knuth's "Seminumerical Algorithms". */
655 int num_hi_sig, den_hi_sig;
656 unsigned HOST_WIDE_INT quo_est, scale;
658 /* Find the highest nonzero divisor digit. */
659 for (i = 4 - 1;; i--)
666 /* Insure that the first digit of the divisor is at least BASE/2.
667 This is required by the quotient digit estimation algorithm. */
669 scale = BASE / (den[den_hi_sig] + 1);
671 { /* scale divisor and dividend */
673 for (i = 0; i <= 4 - 1; i++)
675 work = (num[i] * scale) + carry;
676 num[i] = LOWPART (work);
677 carry = HIGHPART (work);
682 for (i = 0; i <= 4 - 1; i++)
684 work = (den[i] * scale) + carry;
685 den[i] = LOWPART (work);
686 carry = HIGHPART (work);
687 if (den[i] != 0) den_hi_sig = i;
694 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
696 /* Guess the next quotient digit, quo_est, by dividing the first
697 two remaining dividend digits by the high order quotient digit.
698 quo_est is never low and is at most 2 high. */
699 unsigned HOST_WIDE_INT tmp;
701 num_hi_sig = i + den_hi_sig + 1;
702 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
703 if (num[num_hi_sig] != den[den_hi_sig])
704 quo_est = work / den[den_hi_sig];
708 /* Refine quo_est so it's usually correct, and at most one high. */
709 tmp = work - quo_est * den[den_hi_sig];
711 && (den[den_hi_sig - 1] * quo_est
712 > (tmp * BASE + num[num_hi_sig - 2])))
715 /* Try QUO_EST as the quotient digit, by multiplying the
716 divisor by QUO_EST and subtracting from the remaining dividend.
717 Keep in mind that QUO_EST is the I - 1st digit. */
720 for (j = 0; j <= den_hi_sig; j++)
722 work = quo_est * den[j] + carry;
723 carry = HIGHPART (work);
724 work = num[i + j] - LOWPART (work);
725 num[i + j] = LOWPART (work);
726 carry += HIGHPART (work) != 0;
729 /* If quo_est was high by one, then num[i] went negative and
730 we need to correct things. */
731 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
734 carry = 0; /* add divisor back in */
735 for (j = 0; j <= den_hi_sig; j++)
737 work = num[i + j] + den[j] + carry;
738 carry = HIGHPART (work);
739 num[i + j] = LOWPART (work);
742 num [num_hi_sig] += carry;
745 /* Store the quotient digit. */
750 decode (quo, lquo, hquo);
753 /* if result is negative, make it so. */
755 neg_double (*lquo, *hquo, lquo, hquo);
757 /* compute trial remainder: rem = num - (quo * den) */
758 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
759 neg_double (*lrem, *hrem, lrem, hrem);
760 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
765 case TRUNC_MOD_EXPR: /* round toward zero */
766 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
770 case FLOOR_MOD_EXPR: /* round toward negative infinity */
771 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
774 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
782 case CEIL_MOD_EXPR: /* round toward positive infinity */
783 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
785 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
793 case ROUND_MOD_EXPR: /* round to closest integer */
795 unsigned HOST_WIDE_INT labs_rem = *lrem;
796 HOST_WIDE_INT habs_rem = *hrem;
797 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
798 HOST_WIDE_INT habs_den = hden, htwice;
800 /* Get absolute values */
802 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
804 neg_double (lden, hden, &labs_den, &habs_den);
806 /* If (2 * abs (lrem) >= abs (lden)) */
807 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
808 labs_rem, habs_rem, <wice, &htwice);
810 if (((unsigned HOST_WIDE_INT) habs_den
811 < (unsigned HOST_WIDE_INT) htwice)
812 || (((unsigned HOST_WIDE_INT) habs_den
813 == (unsigned HOST_WIDE_INT) htwice)
814 && (labs_den < ltwice)))
818 add_double (*lquo, *hquo,
819 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
822 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
834 /* compute true remainder: rem = num - (quo * den) */
835 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
836 neg_double (*lrem, *hrem, lrem, hrem);
837 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
841 /* Determine whether an expression T can be cheaply negated using
842 the function negate_expr. */
848 unsigned HOST_WIDE_INT val;
855 type = TREE_TYPE (t);
858 switch (TREE_CODE (t))
861 if (TREE_UNSIGNED (type))
864 /* Check that -CST will not overflow type. */
865 prec = TYPE_PRECISION (type);
866 if (prec > HOST_BITS_PER_WIDE_INT)
868 if (TREE_INT_CST_LOW (t) != 0)
870 prec -= HOST_BITS_PER_WIDE_INT;
871 val = TREE_INT_CST_HIGH (t);
874 val = TREE_INT_CST_LOW (t);
875 if (prec < HOST_BITS_PER_WIDE_INT)
876 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
877 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
890 /* Given T, an expression, return the negation of T. Allow for T to be
891 null, in which case return null. */
903 type = TREE_TYPE (t);
906 switch (TREE_CODE (t))
910 if (! TREE_UNSIGNED (type)
911 && 0 != (tem = fold (build1 (NEGATE_EXPR, type, t)))
912 && ! TREE_OVERFLOW (tem))
917 return convert (type, TREE_OPERAND (t, 0));
920 /* - (A - B) -> B - A */
921 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
922 return convert (type,
923 fold (build (MINUS_EXPR, TREE_TYPE (t),
925 TREE_OPERAND (t, 0))));
932 return convert (type, fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t)));
935 /* Split a tree IN into a constant, literal and variable parts that could be
936 combined with CODE to make IN. "constant" means an expression with
937 TREE_CONSTANT but that isn't an actual constant. CODE must be a
938 commutative arithmetic operation. Store the constant part into *CONP,
939 the literal in *LITP and return the variable part. If a part isn't
940 present, set it to null. If the tree does not decompose in this way,
941 return the entire tree as the variable part and the other parts as null.
943 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
944 case, we negate an operand that was subtracted. Except if it is a
945 literal for which we use *MINUS_LITP instead.
947 If NEGATE_P is true, we are negating all of IN, again except a literal
948 for which we use *MINUS_LITP instead.
950 If IN is itself a literal or constant, return it as appropriate.
952 Note that we do not guarantee that any of the three values will be the
953 same type as IN, but they will have the same signedness and mode. */
956 split_tree (in, code, conp, litp, minus_litp, negate_p)
959 tree *conp, *litp, *minus_litp;
968 /* Strip any conversions that don't change the machine mode or signedness. */
969 STRIP_SIGN_NOPS (in);
971 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
973 else if (TREE_CODE (in) == code
974 || (! FLOAT_TYPE_P (TREE_TYPE (in))
975 /* We can associate addition and subtraction together (even
976 though the C standard doesn't say so) for integers because
977 the value is not affected. For reals, the value might be
978 affected, so we can't. */
979 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
980 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
982 tree op0 = TREE_OPERAND (in, 0);
983 tree op1 = TREE_OPERAND (in, 1);
984 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
985 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
987 /* First see if either of the operands is a literal, then a constant. */
988 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
989 *litp = op0, op0 = 0;
990 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
991 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
993 if (op0 != 0 && TREE_CONSTANT (op0))
994 *conp = op0, op0 = 0;
995 else if (op1 != 0 && TREE_CONSTANT (op1))
996 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
998 /* If we haven't dealt with either operand, this is not a case we can
999 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1000 if (op0 != 0 && op1 != 0)
1005 var = op1, neg_var_p = neg1_p;
1007 /* Now do any needed negations. */
1009 *minus_litp = *litp, *litp = 0;
1011 *conp = negate_expr (*conp);
1013 var = negate_expr (var);
1015 else if (TREE_CONSTANT (in))
1023 *minus_litp = *litp, *litp = 0;
1024 else if (*minus_litp)
1025 *litp = *minus_litp, *minus_litp = 0;
1026 *conp = negate_expr (*conp);
1027 var = negate_expr (var);
1033 /* Re-associate trees split by the above function. T1 and T2 are either
1034 expressions to associate or null. Return the new expression, if any. If
1035 we build an operation, do it in TYPE and with CODE. */
1038 associate_trees (t1, t2, code, type)
1040 enum tree_code code;
1048 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1049 try to fold this since we will have infinite recursion. But do
1050 deal with any NEGATE_EXPRs. */
1051 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1052 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1054 if (code == PLUS_EXPR)
1056 if (TREE_CODE (t1) == NEGATE_EXPR)
1057 return build (MINUS_EXPR, type, convert (type, t2),
1058 convert (type, TREE_OPERAND (t1, 0)));
1059 else if (TREE_CODE (t2) == NEGATE_EXPR)
1060 return build (MINUS_EXPR, type, convert (type, t1),
1061 convert (type, TREE_OPERAND (t2, 0)));
1063 return build (code, type, convert (type, t1), convert (type, t2));
1066 return fold (build (code, type, convert (type, t1), convert (type, t2)));
1069 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1070 to produce a new constant.
1072 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1075 int_const_binop (code, arg1, arg2, notrunc)
1076 enum tree_code code;
1080 unsigned HOST_WIDE_INT int1l, int2l;
1081 HOST_WIDE_INT int1h, int2h;
1082 unsigned HOST_WIDE_INT low;
1084 unsigned HOST_WIDE_INT garbagel;
1085 HOST_WIDE_INT garbageh;
1087 tree type = TREE_TYPE (arg1);
1088 int uns = TREE_UNSIGNED (type);
1090 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1092 int no_overflow = 0;
1094 int1l = TREE_INT_CST_LOW (arg1);
1095 int1h = TREE_INT_CST_HIGH (arg1);
1096 int2l = TREE_INT_CST_LOW (arg2);
1097 int2h = TREE_INT_CST_HIGH (arg2);
1102 low = int1l | int2l, hi = int1h | int2h;
1106 low = int1l ^ int2l, hi = int1h ^ int2h;
1110 low = int1l & int2l, hi = int1h & int2h;
1113 case BIT_ANDTC_EXPR:
1114 low = int1l & ~int2l, hi = int1h & ~int2h;
1120 /* It's unclear from the C standard whether shifts can overflow.
1121 The following code ignores overflow; perhaps a C standard
1122 interpretation ruling is needed. */
1123 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1131 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1136 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1140 neg_double (int2l, int2h, &low, &hi);
1141 add_double (int1l, int1h, low, hi, &low, &hi);
1142 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1146 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1149 case TRUNC_DIV_EXPR:
1150 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1151 case EXACT_DIV_EXPR:
1152 /* This is a shortcut for a common special case. */
1153 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1154 && ! TREE_CONSTANT_OVERFLOW (arg1)
1155 && ! TREE_CONSTANT_OVERFLOW (arg2)
1156 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1158 if (code == CEIL_DIV_EXPR)
1161 low = int1l / int2l, hi = 0;
1165 /* ... fall through ... */
1167 case ROUND_DIV_EXPR:
1168 if (int2h == 0 && int2l == 1)
1170 low = int1l, hi = int1h;
1173 if (int1l == int2l && int1h == int2h
1174 && ! (int1l == 0 && int1h == 0))
1179 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1180 &low, &hi, &garbagel, &garbageh);
1183 case TRUNC_MOD_EXPR:
1184 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1185 /* This is a shortcut for a common special case. */
1186 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1187 && ! TREE_CONSTANT_OVERFLOW (arg1)
1188 && ! TREE_CONSTANT_OVERFLOW (arg2)
1189 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1191 if (code == CEIL_MOD_EXPR)
1193 low = int1l % int2l, hi = 0;
1197 /* ... fall through ... */
1199 case ROUND_MOD_EXPR:
1200 overflow = div_and_round_double (code, uns,
1201 int1l, int1h, int2l, int2h,
1202 &garbagel, &garbageh, &low, &hi);
1208 low = (((unsigned HOST_WIDE_INT) int1h
1209 < (unsigned HOST_WIDE_INT) int2h)
1210 || (((unsigned HOST_WIDE_INT) int1h
1211 == (unsigned HOST_WIDE_INT) int2h)
1214 low = (int1h < int2h
1215 || (int1h == int2h && int1l < int2l));
1217 if (low == (code == MIN_EXPR))
1218 low = int1l, hi = int1h;
1220 low = int2l, hi = int2h;
1227 /* If this is for a sizetype, can be represented as one (signed)
1228 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1231 && ((hi == 0 && (HOST_WIDE_INT) low >= 0)
1232 || (hi == -1 && (HOST_WIDE_INT) low < 0))
1233 && overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1234 return size_int_type_wide (low, type);
1237 t = build_int_2 (low, hi);
1238 TREE_TYPE (t) = TREE_TYPE (arg1);
1243 ? (!uns || is_sizetype) && overflow
1244 : (force_fit_type (t, (!uns || is_sizetype) && overflow)
1246 | TREE_OVERFLOW (arg1)
1247 | TREE_OVERFLOW (arg2));
1249 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1250 So check if force_fit_type truncated the value. */
1252 && ! TREE_OVERFLOW (t)
1253 && (TREE_INT_CST_HIGH (t) != hi
1254 || TREE_INT_CST_LOW (t) != low))
1255 TREE_OVERFLOW (t) = 1;
1257 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1258 | TREE_CONSTANT_OVERFLOW (arg1)
1259 | TREE_CONSTANT_OVERFLOW (arg2));
1263 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1264 constant. We assume ARG1 and ARG2 have the same data type, or at least
1265 are the same kind of constant and the same machine mode.
1267 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1270 const_binop (code, arg1, arg2, notrunc)
1271 enum tree_code code;
1278 if (TREE_CODE (arg1) == INTEGER_CST)
1279 return int_const_binop (code, arg1, arg2, notrunc);
1281 if (TREE_CODE (arg1) == REAL_CST)
1285 REAL_VALUE_TYPE value;
1288 d1 = TREE_REAL_CST (arg1);
1289 d2 = TREE_REAL_CST (arg2);
1291 /* If either operand is a NaN, just return it. Otherwise, set up
1292 for floating-point trap; we return an overflow. */
1293 if (REAL_VALUE_ISNAN (d1))
1295 else if (REAL_VALUE_ISNAN (d2))
1298 REAL_ARITHMETIC (value, code, d1, d2);
1300 t = build_real (TREE_TYPE (arg1),
1301 real_value_truncate (TYPE_MODE (TREE_TYPE (arg1)),
1305 = (force_fit_type (t, 0)
1306 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1307 TREE_CONSTANT_OVERFLOW (t)
1309 | TREE_CONSTANT_OVERFLOW (arg1)
1310 | TREE_CONSTANT_OVERFLOW (arg2);
1313 if (TREE_CODE (arg1) == COMPLEX_CST)
1315 tree type = TREE_TYPE (arg1);
1316 tree r1 = TREE_REALPART (arg1);
1317 tree i1 = TREE_IMAGPART (arg1);
1318 tree r2 = TREE_REALPART (arg2);
1319 tree i2 = TREE_IMAGPART (arg2);
1325 t = build_complex (type,
1326 const_binop (PLUS_EXPR, r1, r2, notrunc),
1327 const_binop (PLUS_EXPR, i1, i2, notrunc));
1331 t = build_complex (type,
1332 const_binop (MINUS_EXPR, r1, r2, notrunc),
1333 const_binop (MINUS_EXPR, i1, i2, notrunc));
1337 t = build_complex (type,
1338 const_binop (MINUS_EXPR,
1339 const_binop (MULT_EXPR,
1341 const_binop (MULT_EXPR,
1344 const_binop (PLUS_EXPR,
1345 const_binop (MULT_EXPR,
1347 const_binop (MULT_EXPR,
1355 = const_binop (PLUS_EXPR,
1356 const_binop (MULT_EXPR, r2, r2, notrunc),
1357 const_binop (MULT_EXPR, i2, i2, notrunc),
1360 t = build_complex (type,
1362 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1363 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1364 const_binop (PLUS_EXPR,
1365 const_binop (MULT_EXPR, r1, r2,
1367 const_binop (MULT_EXPR, i1, i2,
1370 magsquared, notrunc),
1372 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1373 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1374 const_binop (MINUS_EXPR,
1375 const_binop (MULT_EXPR, i1, r2,
1377 const_binop (MULT_EXPR, r1, i2,
1380 magsquared, notrunc));
1392 /* These are the hash table functions for the hash table of INTEGER_CST
1393 nodes of a sizetype. */
1395 /* Return the hash code code X, an INTEGER_CST. */
1403 return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
1404 ^ htab_hash_pointer (TREE_TYPE (t))
1405 ^ (TREE_OVERFLOW (t) << 20));
1408 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1409 is the same as that given by *Y, which is the same. */
1419 return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
1420 && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt)
1421 && TREE_TYPE (xt) == TREE_TYPE (yt)
1422 && TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt));
1425 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1426 bits are given by NUMBER and of the sizetype represented by KIND. */
1429 size_int_wide (number, kind)
1430 HOST_WIDE_INT number;
1431 enum size_type_kind kind;
1433 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1436 /* Likewise, but the desired type is specified explicitly. */
1438 static GTY (()) tree new_const;
1439 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
1443 size_int_type_wide (number, type)
1444 HOST_WIDE_INT number;
1451 size_htab = htab_create_ggc (1024, size_htab_hash, size_htab_eq, NULL);
1452 new_const = make_node (INTEGER_CST);
1455 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1456 hash table, we return the value from the hash table. Otherwise, we
1457 place that in the hash table and make a new node for the next time. */
1458 TREE_INT_CST_LOW (new_const) = number;
1459 TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0;
1460 TREE_TYPE (new_const) = type;
1461 TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const)
1462 = force_fit_type (new_const, 0);
1464 slot = htab_find_slot (size_htab, new_const, INSERT);
1469 *slot = (PTR) new_const;
1470 new_const = make_node (INTEGER_CST);
1474 return (tree) *slot;
1477 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1478 is a tree code. The type of the result is taken from the operands.
1479 Both must be the same type integer type and it must be a size type.
1480 If the operands are constant, so is the result. */
1483 size_binop (code, arg0, arg1)
1484 enum tree_code code;
1487 tree type = TREE_TYPE (arg0);
1489 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1490 || type != TREE_TYPE (arg1))
1493 /* Handle the special case of two integer constants faster. */
1494 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1496 /* And some specific cases even faster than that. */
1497 if (code == PLUS_EXPR && integer_zerop (arg0))
1499 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1500 && integer_zerop (arg1))
1502 else if (code == MULT_EXPR && integer_onep (arg0))
1505 /* Handle general case of two integer constants. */
1506 return int_const_binop (code, arg0, arg1, 0);
1509 if (arg0 == error_mark_node || arg1 == error_mark_node)
1510 return error_mark_node;
1512 return fold (build (code, type, arg0, arg1));
1515 /* Given two values, either both of sizetype or both of bitsizetype,
1516 compute the difference between the two values. Return the value
1517 in signed type corresponding to the type of the operands. */
1520 size_diffop (arg0, arg1)
1523 tree type = TREE_TYPE (arg0);
1526 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1527 || type != TREE_TYPE (arg1))
1530 /* If the type is already signed, just do the simple thing. */
1531 if (! TREE_UNSIGNED (type))
1532 return size_binop (MINUS_EXPR, arg0, arg1);
1534 ctype = (type == bitsizetype || type == ubitsizetype
1535 ? sbitsizetype : ssizetype);
1537 /* If either operand is not a constant, do the conversions to the signed
1538 type and subtract. The hardware will do the right thing with any
1539 overflow in the subtraction. */
1540 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1541 return size_binop (MINUS_EXPR, convert (ctype, arg0),
1542 convert (ctype, arg1));
1544 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1545 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1546 overflow) and negate (which can't either). Special-case a result
1547 of zero while we're here. */
1548 if (tree_int_cst_equal (arg0, arg1))
1549 return convert (ctype, integer_zero_node);
1550 else if (tree_int_cst_lt (arg1, arg0))
1551 return convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1553 return size_binop (MINUS_EXPR, convert (ctype, integer_zero_node),
1554 convert (ctype, size_binop (MINUS_EXPR, arg1, arg0)));
1558 /* Given T, a tree representing type conversion of ARG1, a constant,
1559 return a constant tree representing the result of conversion. */
1562 fold_convert (t, arg1)
1566 tree type = TREE_TYPE (t);
1569 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1571 if (TREE_CODE (arg1) == INTEGER_CST)
1573 /* If we would build a constant wider than GCC supports,
1574 leave the conversion unfolded. */
1575 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1578 /* If we are trying to make a sizetype for a small integer, use
1579 size_int to pick up cached types to reduce duplicate nodes. */
1580 if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1581 && !TREE_CONSTANT_OVERFLOW (arg1)
1582 && compare_tree_int (arg1, 10000) < 0)
1583 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
1585 /* Given an integer constant, make new constant with new type,
1586 appropriately sign-extended or truncated. */
1587 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1588 TREE_INT_CST_HIGH (arg1));
1589 TREE_TYPE (t) = type;
1590 /* Indicate an overflow if (1) ARG1 already overflowed,
1591 or (2) force_fit_type indicates an overflow.
1592 Tell force_fit_type that an overflow has already occurred
1593 if ARG1 is a too-large unsigned value and T is signed.
1594 But don't indicate an overflow if converting a pointer. */
1596 = ((force_fit_type (t,
1597 (TREE_INT_CST_HIGH (arg1) < 0
1598 && (TREE_UNSIGNED (type)
1599 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
1600 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1601 || TREE_OVERFLOW (arg1));
1602 TREE_CONSTANT_OVERFLOW (t)
1603 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1605 else if (TREE_CODE (arg1) == REAL_CST)
1607 /* Don't initialize these, use assignments.
1608 Initialized local aggregates don't work on old compilers. */
1612 tree type1 = TREE_TYPE (arg1);
1615 x = TREE_REAL_CST (arg1);
1616 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
1618 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
1619 if (!no_upper_bound)
1620 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
1622 /* See if X will be in range after truncation towards 0.
1623 To compensate for truncation, move the bounds away from 0,
1624 but reject if X exactly equals the adjusted bounds. */
1625 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
1626 if (!no_upper_bound)
1627 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
1628 /* If X is a NaN, use zero instead and show we have an overflow.
1629 Otherwise, range check. */
1630 if (REAL_VALUE_ISNAN (x))
1631 overflow = 1, x = dconst0;
1632 else if (! (REAL_VALUES_LESS (l, x)
1634 && REAL_VALUES_LESS (x, u)))
1638 HOST_WIDE_INT low, high;
1639 REAL_VALUE_TO_INT (&low, &high, x);
1640 t = build_int_2 (low, high);
1642 TREE_TYPE (t) = type;
1644 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1645 TREE_CONSTANT_OVERFLOW (t)
1646 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1648 TREE_TYPE (t) = type;
1650 else if (TREE_CODE (type) == REAL_TYPE)
1652 if (TREE_CODE (arg1) == INTEGER_CST)
1653 return build_real_from_int_cst (type, arg1);
1654 if (TREE_CODE (arg1) == REAL_CST)
1656 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1658 /* We make a copy of ARG1 so that we don't modify an
1659 existing constant tree. */
1660 t = copy_node (arg1);
1661 TREE_TYPE (t) = type;
1665 t = build_real (type,
1666 real_value_truncate (TYPE_MODE (type),
1667 TREE_REAL_CST (arg1)));
1670 = TREE_OVERFLOW (arg1) | force_fit_type (t, 0);
1671 TREE_CONSTANT_OVERFLOW (t)
1672 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1676 TREE_CONSTANT (t) = 1;
1680 /* Return an expr equal to X but certainly not valid as an lvalue. */
1688 /* These things are certainly not lvalues. */
1689 if (TREE_CODE (x) == NON_LVALUE_EXPR
1690 || TREE_CODE (x) == INTEGER_CST
1691 || TREE_CODE (x) == REAL_CST
1692 || TREE_CODE (x) == STRING_CST
1693 || TREE_CODE (x) == ADDR_EXPR)
1696 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
1697 TREE_CONSTANT (result) = TREE_CONSTANT (x);
1701 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1702 Zero means allow extended lvalues. */
1704 int pedantic_lvalues;
1706 /* When pedantic, return an expr equal to X but certainly not valid as a
1707 pedantic lvalue. Otherwise, return X. */
1710 pedantic_non_lvalue (x)
1713 if (pedantic_lvalues)
1714 return non_lvalue (x);
1719 /* Given a tree comparison code, return the code that is the logical inverse
1720 of the given code. It is not safe to do this for floating-point
1721 comparisons, except for NE_EXPR and EQ_EXPR. */
1723 static enum tree_code
1724 invert_tree_comparison (code)
1725 enum tree_code code;
1746 /* Similar, but return the comparison that results if the operands are
1747 swapped. This is safe for floating-point. */
1749 static enum tree_code
1750 swap_tree_comparison (code)
1751 enum tree_code code;
1772 /* Convert a comparison tree code from an enum tree_code representation
1773 into a compcode bit-based encoding. This function is the inverse of
1774 compcode_to_comparison. */
1777 comparison_to_compcode (code)
1778 enum tree_code code;
1799 /* Convert a compcode bit-based encoding of a comparison operator back
1800 to GCC's enum tree_code representation. This function is the
1801 inverse of comparison_to_compcode. */
1803 static enum tree_code
1804 compcode_to_comparison (code)
1826 /* Return nonzero if CODE is a tree code that represents a truth value. */
1829 truth_value_p (code)
1830 enum tree_code code;
1832 return (TREE_CODE_CLASS (code) == '<'
1833 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
1834 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
1835 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
1838 /* Return nonzero if two operands are necessarily equal.
1839 If ONLY_CONST is nonzero, only return nonzero for constants.
1840 This function tests whether the operands are indistinguishable;
1841 it does not test whether they are equal using C's == operation.
1842 The distinction is important for IEEE floating point, because
1843 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
1844 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
1847 operand_equal_p (arg0, arg1, only_const)
1851 /* If both types don't have the same signedness, then we can't consider
1852 them equal. We must check this before the STRIP_NOPS calls
1853 because they may change the signedness of the arguments. */
1854 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
1860 if (TREE_CODE (arg0) != TREE_CODE (arg1)
1861 /* This is needed for conversions and for COMPONENT_REF.
1862 Might as well play it safe and always test this. */
1863 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
1864 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
1865 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
1868 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
1869 We don't care about side effects in that case because the SAVE_EXPR
1870 takes care of that for us. In all other cases, two expressions are
1871 equal if they have no side effects. If we have two identical
1872 expressions with side effects that should be treated the same due
1873 to the only side effects being identical SAVE_EXPR's, that will
1874 be detected in the recursive calls below. */
1875 if (arg0 == arg1 && ! only_const
1876 && (TREE_CODE (arg0) == SAVE_EXPR
1877 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
1880 /* Next handle constant cases, those for which we can return 1 even
1881 if ONLY_CONST is set. */
1882 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
1883 switch (TREE_CODE (arg0))
1886 return (! TREE_CONSTANT_OVERFLOW (arg0)
1887 && ! TREE_CONSTANT_OVERFLOW (arg1)
1888 && tree_int_cst_equal (arg0, arg1));
1891 return (! TREE_CONSTANT_OVERFLOW (arg0)
1892 && ! TREE_CONSTANT_OVERFLOW (arg1)
1893 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
1894 TREE_REAL_CST (arg1)));
1900 if (TREE_CONSTANT_OVERFLOW (arg0)
1901 || TREE_CONSTANT_OVERFLOW (arg1))
1904 v1 = TREE_VECTOR_CST_ELTS (arg0);
1905 v2 = TREE_VECTOR_CST_ELTS (arg1);
1908 if (!operand_equal_p (v1, v2, only_const))
1910 v1 = TREE_CHAIN (v1);
1911 v2 = TREE_CHAIN (v2);
1918 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
1920 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
1924 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
1925 && ! memcmp (TREE_STRING_POINTER (arg0),
1926 TREE_STRING_POINTER (arg1),
1927 TREE_STRING_LENGTH (arg0)));
1930 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
1939 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
1942 /* Two conversions are equal only if signedness and modes match. */
1943 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
1944 && (TREE_UNSIGNED (TREE_TYPE (arg0))
1945 != TREE_UNSIGNED (TREE_TYPE (arg1))))
1948 return operand_equal_p (TREE_OPERAND (arg0, 0),
1949 TREE_OPERAND (arg1, 0), 0);
1953 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
1954 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
1958 /* For commutative ops, allow the other order. */
1959 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
1960 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
1961 || TREE_CODE (arg0) == BIT_IOR_EXPR
1962 || TREE_CODE (arg0) == BIT_XOR_EXPR
1963 || TREE_CODE (arg0) == BIT_AND_EXPR
1964 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
1965 && operand_equal_p (TREE_OPERAND (arg0, 0),
1966 TREE_OPERAND (arg1, 1), 0)
1967 && operand_equal_p (TREE_OPERAND (arg0, 1),
1968 TREE_OPERAND (arg1, 0), 0));
1971 /* If either of the pointer (or reference) expressions we are dereferencing
1972 contain a side effect, these cannot be equal. */
1973 if (TREE_SIDE_EFFECTS (arg0)
1974 || TREE_SIDE_EFFECTS (arg1))
1977 switch (TREE_CODE (arg0))
1980 return operand_equal_p (TREE_OPERAND (arg0, 0),
1981 TREE_OPERAND (arg1, 0), 0);
1985 case ARRAY_RANGE_REF:
1986 return (operand_equal_p (TREE_OPERAND (arg0, 0),
1987 TREE_OPERAND (arg1, 0), 0)
1988 && operand_equal_p (TREE_OPERAND (arg0, 1),
1989 TREE_OPERAND (arg1, 1), 0));
1992 return (operand_equal_p (TREE_OPERAND (arg0, 0),
1993 TREE_OPERAND (arg1, 0), 0)
1994 && operand_equal_p (TREE_OPERAND (arg0, 1),
1995 TREE_OPERAND (arg1, 1), 0)
1996 && operand_equal_p (TREE_OPERAND (arg0, 2),
1997 TREE_OPERAND (arg1, 2), 0));
2003 if (TREE_CODE (arg0) == RTL_EXPR)
2004 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2012 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2013 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2015 When in doubt, return 0. */
2018 operand_equal_for_comparison_p (arg0, arg1, other)
2022 int unsignedp1, unsignedpo;
2023 tree primarg0, primarg1, primother;
2024 unsigned int correct_width;
2026 if (operand_equal_p (arg0, arg1, 0))
2029 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2030 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2033 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2034 and see if the inner values are the same. This removes any
2035 signedness comparison, which doesn't matter here. */
2036 primarg0 = arg0, primarg1 = arg1;
2037 STRIP_NOPS (primarg0);
2038 STRIP_NOPS (primarg1);
2039 if (operand_equal_p (primarg0, primarg1, 0))
2042 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2043 actual comparison operand, ARG0.
2045 First throw away any conversions to wider types
2046 already present in the operands. */
2048 primarg1 = get_narrower (arg1, &unsignedp1);
2049 primother = get_narrower (other, &unsignedpo);
2051 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2052 if (unsignedp1 == unsignedpo
2053 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2054 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2056 tree type = TREE_TYPE (arg0);
2058 /* Make sure shorter operand is extended the right way
2059 to match the longer operand. */
2060 primarg1 = convert ((*lang_hooks.types.signed_or_unsigned_type)
2061 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2063 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2070 /* See if ARG is an expression that is either a comparison or is performing
2071 arithmetic on comparisons. The comparisons must only be comparing
2072 two different values, which will be stored in *CVAL1 and *CVAL2; if
2073 they are nonzero it means that some operands have already been found.
2074 No variables may be used anywhere else in the expression except in the
2075 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2076 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2078 If this is true, return 1. Otherwise, return zero. */
2081 twoval_comparison_p (arg, cval1, cval2, save_p)
2083 tree *cval1, *cval2;
2086 enum tree_code code = TREE_CODE (arg);
2087 char class = TREE_CODE_CLASS (code);
2089 /* We can handle some of the 'e' cases here. */
2090 if (class == 'e' && code == TRUTH_NOT_EXPR)
2092 else if (class == 'e'
2093 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2094 || code == COMPOUND_EXPR))
2097 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2098 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2100 /* If we've already found a CVAL1 or CVAL2, this expression is
2101 two complex to handle. */
2102 if (*cval1 || *cval2)
2112 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2115 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2116 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2117 cval1, cval2, save_p));
2123 if (code == COND_EXPR)
2124 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2125 cval1, cval2, save_p)
2126 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2127 cval1, cval2, save_p)
2128 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2129 cval1, cval2, save_p));
2133 /* First see if we can handle the first operand, then the second. For
2134 the second operand, we know *CVAL1 can't be zero. It must be that
2135 one side of the comparison is each of the values; test for the
2136 case where this isn't true by failing if the two operands
2139 if (operand_equal_p (TREE_OPERAND (arg, 0),
2140 TREE_OPERAND (arg, 1), 0))
2144 *cval1 = TREE_OPERAND (arg, 0);
2145 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2147 else if (*cval2 == 0)
2148 *cval2 = TREE_OPERAND (arg, 0);
2149 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2154 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2156 else if (*cval2 == 0)
2157 *cval2 = TREE_OPERAND (arg, 1);
2158 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2170 /* ARG is a tree that is known to contain just arithmetic operations and
2171 comparisons. Evaluate the operations in the tree substituting NEW0 for
2172 any occurrence of OLD0 as an operand of a comparison and likewise for
2176 eval_subst (arg, old0, new0, old1, new1)
2178 tree old0, new0, old1, new1;
2180 tree type = TREE_TYPE (arg);
2181 enum tree_code code = TREE_CODE (arg);
2182 char class = TREE_CODE_CLASS (code);
2184 /* We can handle some of the 'e' cases here. */
2185 if (class == 'e' && code == TRUTH_NOT_EXPR)
2187 else if (class == 'e'
2188 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2194 return fold (build1 (code, type,
2195 eval_subst (TREE_OPERAND (arg, 0),
2196 old0, new0, old1, new1)));
2199 return fold (build (code, type,
2200 eval_subst (TREE_OPERAND (arg, 0),
2201 old0, new0, old1, new1),
2202 eval_subst (TREE_OPERAND (arg, 1),
2203 old0, new0, old1, new1)));
2209 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2212 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2215 return fold (build (code, type,
2216 eval_subst (TREE_OPERAND (arg, 0),
2217 old0, new0, old1, new1),
2218 eval_subst (TREE_OPERAND (arg, 1),
2219 old0, new0, old1, new1),
2220 eval_subst (TREE_OPERAND (arg, 2),
2221 old0, new0, old1, new1)));
2225 /* fall through - ??? */
2229 tree arg0 = TREE_OPERAND (arg, 0);
2230 tree arg1 = TREE_OPERAND (arg, 1);
2232 /* We need to check both for exact equality and tree equality. The
2233 former will be true if the operand has a side-effect. In that
2234 case, we know the operand occurred exactly once. */
2236 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2238 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2241 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2243 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2246 return fold (build (code, type, arg0, arg1));
2254 /* Return a tree for the case when the result of an expression is RESULT
2255 converted to TYPE and OMITTED was previously an operand of the expression
2256 but is now not needed (e.g., we folded OMITTED * 0).
2258 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2259 the conversion of RESULT to TYPE. */
2262 omit_one_operand (type, result, omitted)
2263 tree type, result, omitted;
2265 tree t = convert (type, result);
2267 if (TREE_SIDE_EFFECTS (omitted))
2268 return build (COMPOUND_EXPR, type, omitted, t);
2270 return non_lvalue (t);
2273 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2276 pedantic_omit_one_operand (type, result, omitted)
2277 tree type, result, omitted;
2279 tree t = convert (type, result);
2281 if (TREE_SIDE_EFFECTS (omitted))
2282 return build (COMPOUND_EXPR, type, omitted, t);
2284 return pedantic_non_lvalue (t);
2287 /* Return a simplified tree node for the truth-negation of ARG. This
2288 never alters ARG itself. We assume that ARG is an operation that
2289 returns a truth value (0 or 1). */
2292 invert_truthvalue (arg)
2295 tree type = TREE_TYPE (arg);
2296 enum tree_code code = TREE_CODE (arg);
2298 if (code == ERROR_MARK)
2301 /* If this is a comparison, we can simply invert it, except for
2302 floating-point non-equality comparisons, in which case we just
2303 enclose a TRUTH_NOT_EXPR around what we have. */
2305 if (TREE_CODE_CLASS (code) == '<')
2307 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2308 && !flag_unsafe_math_optimizations
2311 return build1 (TRUTH_NOT_EXPR, type, arg);
2313 return build (invert_tree_comparison (code), type,
2314 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2320 return convert (type, build_int_2 (integer_zerop (arg), 0));
2322 case TRUTH_AND_EXPR:
2323 return build (TRUTH_OR_EXPR, type,
2324 invert_truthvalue (TREE_OPERAND (arg, 0)),
2325 invert_truthvalue (TREE_OPERAND (arg, 1)));
2328 return build (TRUTH_AND_EXPR, type,
2329 invert_truthvalue (TREE_OPERAND (arg, 0)),
2330 invert_truthvalue (TREE_OPERAND (arg, 1)));
2332 case TRUTH_XOR_EXPR:
2333 /* Here we can invert either operand. We invert the first operand
2334 unless the second operand is a TRUTH_NOT_EXPR in which case our
2335 result is the XOR of the first operand with the inside of the
2336 negation of the second operand. */
2338 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2339 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2340 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2342 return build (TRUTH_XOR_EXPR, type,
2343 invert_truthvalue (TREE_OPERAND (arg, 0)),
2344 TREE_OPERAND (arg, 1));
2346 case TRUTH_ANDIF_EXPR:
2347 return build (TRUTH_ORIF_EXPR, type,
2348 invert_truthvalue (TREE_OPERAND (arg, 0)),
2349 invert_truthvalue (TREE_OPERAND (arg, 1)));
2351 case TRUTH_ORIF_EXPR:
2352 return build (TRUTH_ANDIF_EXPR, type,
2353 invert_truthvalue (TREE_OPERAND (arg, 0)),
2354 invert_truthvalue (TREE_OPERAND (arg, 1)));
2356 case TRUTH_NOT_EXPR:
2357 return TREE_OPERAND (arg, 0);
2360 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2361 invert_truthvalue (TREE_OPERAND (arg, 1)),
2362 invert_truthvalue (TREE_OPERAND (arg, 2)));
2365 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2366 invert_truthvalue (TREE_OPERAND (arg, 1)));
2368 case WITH_RECORD_EXPR:
2369 return build (WITH_RECORD_EXPR, type,
2370 invert_truthvalue (TREE_OPERAND (arg, 0)),
2371 TREE_OPERAND (arg, 1));
2373 case NON_LVALUE_EXPR:
2374 return invert_truthvalue (TREE_OPERAND (arg, 0));
2379 return build1 (TREE_CODE (arg), type,
2380 invert_truthvalue (TREE_OPERAND (arg, 0)));
2383 if (!integer_onep (TREE_OPERAND (arg, 1)))
2385 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2388 return build1 (TRUTH_NOT_EXPR, type, arg);
2390 case CLEANUP_POINT_EXPR:
2391 return build1 (CLEANUP_POINT_EXPR, type,
2392 invert_truthvalue (TREE_OPERAND (arg, 0)));
2397 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2399 return build1 (TRUTH_NOT_EXPR, type, arg);
2402 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2403 operands are another bit-wise operation with a common input. If so,
2404 distribute the bit operations to save an operation and possibly two if
2405 constants are involved. For example, convert
2406 (A | B) & (A | C) into A | (B & C)
2407 Further simplification will occur if B and C are constants.
2409 If this optimization cannot be done, 0 will be returned. */
2412 distribute_bit_expr (code, type, arg0, arg1)
2413 enum tree_code code;
2420 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2421 || TREE_CODE (arg0) == code
2422 || (TREE_CODE (arg0) != BIT_AND_EXPR
2423 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2426 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2428 common = TREE_OPERAND (arg0, 0);
2429 left = TREE_OPERAND (arg0, 1);
2430 right = TREE_OPERAND (arg1, 1);
2432 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2434 common = TREE_OPERAND (arg0, 0);
2435 left = TREE_OPERAND (arg0, 1);
2436 right = TREE_OPERAND (arg1, 0);
2438 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2440 common = TREE_OPERAND (arg0, 1);
2441 left = TREE_OPERAND (arg0, 0);
2442 right = TREE_OPERAND (arg1, 1);
2444 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2446 common = TREE_OPERAND (arg0, 1);
2447 left = TREE_OPERAND (arg0, 0);
2448 right = TREE_OPERAND (arg1, 0);
2453 return fold (build (TREE_CODE (arg0), type, common,
2454 fold (build (code, type, left, right))));
2457 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2458 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2461 make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp)
2464 int bitsize, bitpos;
2467 tree result = build (BIT_FIELD_REF, type, inner,
2468 size_int (bitsize), bitsize_int (bitpos));
2470 TREE_UNSIGNED (result) = unsignedp;
2475 /* Optimize a bit-field compare.
2477 There are two cases: First is a compare against a constant and the
2478 second is a comparison of two items where the fields are at the same
2479 bit position relative to the start of a chunk (byte, halfword, word)
2480 large enough to contain it. In these cases we can avoid the shift
2481 implicit in bitfield extractions.
2483 For constants, we emit a compare of the shifted constant with the
2484 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2485 compared. For two fields at the same position, we do the ANDs with the
2486 similar mask and compare the result of the ANDs.
2488 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2489 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2490 are the left and right operands of the comparison, respectively.
2492 If the optimization described above can be done, we return the resulting
2493 tree. Otherwise we return zero. */
2496 optimize_bit_field_compare (code, compare_type, lhs, rhs)
2497 enum tree_code code;
2501 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2502 tree type = TREE_TYPE (lhs);
2503 tree signed_type, unsigned_type;
2504 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2505 enum machine_mode lmode, rmode, nmode;
2506 int lunsignedp, runsignedp;
2507 int lvolatilep = 0, rvolatilep = 0;
2508 tree linner, rinner = NULL_TREE;
2512 /* Get all the information about the extractions being done. If the bit size
2513 if the same as the size of the underlying object, we aren't doing an
2514 extraction at all and so can do nothing. We also don't want to
2515 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2516 then will no longer be able to replace it. */
2517 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2518 &lunsignedp, &lvolatilep);
2519 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2520 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2525 /* If this is not a constant, we can only do something if bit positions,
2526 sizes, and signedness are the same. */
2527 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2528 &runsignedp, &rvolatilep);
2530 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2531 || lunsignedp != runsignedp || offset != 0
2532 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2536 /* See if we can find a mode to refer to this field. We should be able to,
2537 but fail if we can't. */
2538 nmode = get_best_mode (lbitsize, lbitpos,
2539 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2540 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2541 TYPE_ALIGN (TREE_TYPE (rinner))),
2542 word_mode, lvolatilep || rvolatilep);
2543 if (nmode == VOIDmode)
2546 /* Set signed and unsigned types of the precision of this mode for the
2548 signed_type = (*lang_hooks.types.type_for_mode) (nmode, 0);
2549 unsigned_type = (*lang_hooks.types.type_for_mode) (nmode, 1);
2551 /* Compute the bit position and size for the new reference and our offset
2552 within it. If the new reference is the same size as the original, we
2553 won't optimize anything, so return zero. */
2554 nbitsize = GET_MODE_BITSIZE (nmode);
2555 nbitpos = lbitpos & ~ (nbitsize - 1);
2557 if (nbitsize == lbitsize)
2560 if (BYTES_BIG_ENDIAN)
2561 lbitpos = nbitsize - lbitsize - lbitpos;
2563 /* Make the mask to be used against the extracted field. */
2564 mask = build_int_2 (~0, ~0);
2565 TREE_TYPE (mask) = unsigned_type;
2566 force_fit_type (mask, 0);
2567 mask = convert (unsigned_type, mask);
2568 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2569 mask = const_binop (RSHIFT_EXPR, mask,
2570 size_int (nbitsize - lbitsize - lbitpos), 0);
2573 /* If not comparing with constant, just rework the comparison
2575 return build (code, compare_type,
2576 build (BIT_AND_EXPR, unsigned_type,
2577 make_bit_field_ref (linner, unsigned_type,
2578 nbitsize, nbitpos, 1),
2580 build (BIT_AND_EXPR, unsigned_type,
2581 make_bit_field_ref (rinner, unsigned_type,
2582 nbitsize, nbitpos, 1),
2585 /* Otherwise, we are handling the constant case. See if the constant is too
2586 big for the field. Warn and return a tree of for 0 (false) if so. We do
2587 this not only for its own sake, but to avoid having to test for this
2588 error case below. If we didn't, we might generate wrong code.
2590 For unsigned fields, the constant shifted right by the field length should
2591 be all zero. For signed fields, the high-order bits should agree with
2596 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2597 convert (unsigned_type, rhs),
2598 size_int (lbitsize), 0)))
2600 warning ("comparison is always %d due to width of bit-field",
2602 return convert (compare_type,
2604 ? integer_one_node : integer_zero_node));
2609 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
2610 size_int (lbitsize - 1), 0);
2611 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2613 warning ("comparison is always %d due to width of bit-field",
2615 return convert (compare_type,
2617 ? integer_one_node : integer_zero_node));
2621 /* Single-bit compares should always be against zero. */
2622 if (lbitsize == 1 && ! integer_zerop (rhs))
2624 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2625 rhs = convert (type, integer_zero_node);
2628 /* Make a new bitfield reference, shift the constant over the
2629 appropriate number of bits and mask it with the computed mask
2630 (in case this was a signed field). If we changed it, make a new one. */
2631 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
2634 TREE_SIDE_EFFECTS (lhs) = 1;
2635 TREE_THIS_VOLATILE (lhs) = 1;
2638 rhs = fold (const_binop (BIT_AND_EXPR,
2639 const_binop (LSHIFT_EXPR,
2640 convert (unsigned_type, rhs),
2641 size_int (lbitpos), 0),
2644 return build (code, compare_type,
2645 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2649 /* Subroutine for fold_truthop: decode a field reference.
2651 If EXP is a comparison reference, we return the innermost reference.
2653 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2654 set to the starting bit number.
2656 If the innermost field can be completely contained in a mode-sized
2657 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2659 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2660 otherwise it is not changed.
2662 *PUNSIGNEDP is set to the signedness of the field.
2664 *PMASK is set to the mask used. This is either contained in a
2665 BIT_AND_EXPR or derived from the width of the field.
2667 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2669 Return 0 if this is not a component reference or is one that we can't
2670 do anything with. */
2673 decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp,
2674 pvolatilep, pmask, pand_mask)
2676 HOST_WIDE_INT *pbitsize, *pbitpos;
2677 enum machine_mode *pmode;
2678 int *punsignedp, *pvolatilep;
2683 tree mask, inner, offset;
2685 unsigned int precision;
2687 /* All the optimizations using this function assume integer fields.
2688 There are problems with FP fields since the type_for_size call
2689 below can fail for, e.g., XFmode. */
2690 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
2695 if (TREE_CODE (exp) == BIT_AND_EXPR)
2697 and_mask = TREE_OPERAND (exp, 1);
2698 exp = TREE_OPERAND (exp, 0);
2699 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
2700 if (TREE_CODE (and_mask) != INTEGER_CST)
2704 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
2705 punsignedp, pvolatilep);
2706 if ((inner == exp && and_mask == 0)
2707 || *pbitsize < 0 || offset != 0
2708 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
2711 /* Compute the mask to access the bitfield. */
2712 unsigned_type = (*lang_hooks.types.type_for_size) (*pbitsize, 1);
2713 precision = TYPE_PRECISION (unsigned_type);
2715 mask = build_int_2 (~0, ~0);
2716 TREE_TYPE (mask) = unsigned_type;
2717 force_fit_type (mask, 0);
2718 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2719 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2721 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
2723 mask = fold (build (BIT_AND_EXPR, unsigned_type,
2724 convert (unsigned_type, and_mask), mask));
2727 *pand_mask = and_mask;
2731 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
2735 all_ones_mask_p (mask, size)
2739 tree type = TREE_TYPE (mask);
2740 unsigned int precision = TYPE_PRECISION (type);
2743 tmask = build_int_2 (~0, ~0);
2744 TREE_TYPE (tmask) = (*lang_hooks.types.signed_type) (type);
2745 force_fit_type (tmask, 0);
2747 tree_int_cst_equal (mask,
2748 const_binop (RSHIFT_EXPR,
2749 const_binop (LSHIFT_EXPR, tmask,
2750 size_int (precision - size),
2752 size_int (precision - size), 0));
2755 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
2756 represents the sign bit of EXP's type. If EXP represents a sign
2757 or zero extension, also test VAL against the unextended type.
2758 The return value is the (sub)expression whose sign bit is VAL,
2759 or NULL_TREE otherwise. */
2762 sign_bit_p (exp, val)
2766 unsigned HOST_WIDE_INT lo;
2771 /* Tree EXP must have an integral type. */
2772 t = TREE_TYPE (exp);
2773 if (! INTEGRAL_TYPE_P (t))
2776 /* Tree VAL must be an integer constant. */
2777 if (TREE_CODE (val) != INTEGER_CST
2778 || TREE_CONSTANT_OVERFLOW (val))
2781 width = TYPE_PRECISION (t);
2782 if (width > HOST_BITS_PER_WIDE_INT)
2784 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
2790 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
2793 if (TREE_INT_CST_HIGH (val) == hi && TREE_INT_CST_LOW (val) == lo)
2796 /* Handle extension from a narrower type. */
2797 if (TREE_CODE (exp) == NOP_EXPR
2798 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
2799 return sign_bit_p (TREE_OPERAND (exp, 0), val);
2804 /* Subroutine for fold_truthop: determine if an operand is simple enough
2805 to be evaluated unconditionally. */
2808 simple_operand_p (exp)
2811 /* Strip any conversions that don't change the machine mode. */
2812 while ((TREE_CODE (exp) == NOP_EXPR
2813 || TREE_CODE (exp) == CONVERT_EXPR)
2814 && (TYPE_MODE (TREE_TYPE (exp))
2815 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
2816 exp = TREE_OPERAND (exp, 0);
2818 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
2820 && ! TREE_ADDRESSABLE (exp)
2821 && ! TREE_THIS_VOLATILE (exp)
2822 && ! DECL_NONLOCAL (exp)
2823 /* Don't regard global variables as simple. They may be
2824 allocated in ways unknown to the compiler (shared memory,
2825 #pragma weak, etc). */
2826 && ! TREE_PUBLIC (exp)
2827 && ! DECL_EXTERNAL (exp)
2828 /* Loading a static variable is unduly expensive, but global
2829 registers aren't expensive. */
2830 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
2833 /* The following functions are subroutines to fold_range_test and allow it to
2834 try to change a logical combination of comparisons into a range test.
2837 X == 2 || X == 3 || X == 4 || X == 5
2841 (unsigned) (X - 2) <= 3
2843 We describe each set of comparisons as being either inside or outside
2844 a range, using a variable named like IN_P, and then describe the
2845 range with a lower and upper bound. If one of the bounds is omitted,
2846 it represents either the highest or lowest value of the type.
2848 In the comments below, we represent a range by two numbers in brackets
2849 preceded by a "+" to designate being inside that range, or a "-" to
2850 designate being outside that range, so the condition can be inverted by
2851 flipping the prefix. An omitted bound is represented by a "-". For
2852 example, "- [-, 10]" means being outside the range starting at the lowest
2853 possible value and ending at 10, in other words, being greater than 10.
2854 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
2857 We set up things so that the missing bounds are handled in a consistent
2858 manner so neither a missing bound nor "true" and "false" need to be
2859 handled using a special case. */
2861 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
2862 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
2863 and UPPER1_P are nonzero if the respective argument is an upper bound
2864 and zero for a lower. TYPE, if nonzero, is the type of the result; it
2865 must be specified for a comparison. ARG1 will be converted to ARG0's
2866 type if both are specified. */
2869 range_binop (code, type, arg0, upper0_p, arg1, upper1_p)
2870 enum tree_code code;
2873 int upper0_p, upper1_p;
2879 /* If neither arg represents infinity, do the normal operation.
2880 Else, if not a comparison, return infinity. Else handle the special
2881 comparison rules. Note that most of the cases below won't occur, but
2882 are handled for consistency. */
2884 if (arg0 != 0 && arg1 != 0)
2886 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
2887 arg0, convert (TREE_TYPE (arg0), arg1)));
2889 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
2892 if (TREE_CODE_CLASS (code) != '<')
2895 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
2896 for neither. In real maths, we cannot assume open ended ranges are
2897 the same. But, this is computer arithmetic, where numbers are finite.
2898 We can therefore make the transformation of any unbounded range with
2899 the value Z, Z being greater than any representable number. This permits
2900 us to treat unbounded ranges as equal. */
2901 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
2902 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
2906 result = sgn0 == sgn1;
2909 result = sgn0 != sgn1;
2912 result = sgn0 < sgn1;
2915 result = sgn0 <= sgn1;
2918 result = sgn0 > sgn1;
2921 result = sgn0 >= sgn1;
2927 return convert (type, result ? integer_one_node : integer_zero_node);
2930 /* Given EXP, a logical expression, set the range it is testing into
2931 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
2932 actually being tested. *PLOW and *PHIGH will be made of the same type
2933 as the returned expression. If EXP is not a comparison, we will most
2934 likely not be returning a useful value and range. */
2937 make_range (exp, pin_p, plow, phigh)
2942 enum tree_code code;
2943 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
2944 tree orig_type = NULL_TREE;
2946 tree low, high, n_low, n_high;
2948 /* Start with simply saying "EXP != 0" and then look at the code of EXP
2949 and see if we can refine the range. Some of the cases below may not
2950 happen, but it doesn't seem worth worrying about this. We "continue"
2951 the outer loop when we've changed something; otherwise we "break"
2952 the switch, which will "break" the while. */
2954 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
2958 code = TREE_CODE (exp);
2960 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
2962 arg0 = TREE_OPERAND (exp, 0);
2963 if (TREE_CODE_CLASS (code) == '<'
2964 || TREE_CODE_CLASS (code) == '1'
2965 || TREE_CODE_CLASS (code) == '2')
2966 type = TREE_TYPE (arg0);
2967 if (TREE_CODE_CLASS (code) == '2'
2968 || TREE_CODE_CLASS (code) == '<'
2969 || (TREE_CODE_CLASS (code) == 'e'
2970 && TREE_CODE_LENGTH (code) > 1))
2971 arg1 = TREE_OPERAND (exp, 1);
2974 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
2975 lose a cast by accident. */
2976 if (type != NULL_TREE && orig_type == NULL_TREE)
2981 case TRUTH_NOT_EXPR:
2982 in_p = ! in_p, exp = arg0;
2985 case EQ_EXPR: case NE_EXPR:
2986 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
2987 /* We can only do something if the range is testing for zero
2988 and if the second operand is an integer constant. Note that
2989 saying something is "in" the range we make is done by
2990 complementing IN_P since it will set in the initial case of
2991 being not equal to zero; "out" is leaving it alone. */
2992 if (low == 0 || high == 0
2993 || ! integer_zerop (low) || ! integer_zerop (high)
2994 || TREE_CODE (arg1) != INTEGER_CST)
2999 case NE_EXPR: /* - [c, c] */
3002 case EQ_EXPR: /* + [c, c] */
3003 in_p = ! in_p, low = high = arg1;
3005 case GT_EXPR: /* - [-, c] */
3006 low = 0, high = arg1;
3008 case GE_EXPR: /* + [c, -] */
3009 in_p = ! in_p, low = arg1, high = 0;
3011 case LT_EXPR: /* - [c, -] */
3012 low = arg1, high = 0;
3014 case LE_EXPR: /* + [-, c] */
3015 in_p = ! in_p, low = 0, high = arg1;
3023 /* If this is an unsigned comparison, we also know that EXP is
3024 greater than or equal to zero. We base the range tests we make
3025 on that fact, so we record it here so we can parse existing
3027 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3029 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3030 1, convert (type, integer_zero_node),
3034 in_p = n_in_p, low = n_low, high = n_high;
3036 /* If the high bound is missing, but we
3037 have a low bound, reverse the range so
3038 it goes from zero to the low bound minus 1. */
3039 if (high == 0 && low)
3042 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3043 integer_one_node, 0);
3044 low = convert (type, integer_zero_node);
3050 /* (-x) IN [a,b] -> x in [-b, -a] */
3051 n_low = range_binop (MINUS_EXPR, type,
3052 convert (type, integer_zero_node), 0, high, 1);
3053 n_high = range_binop (MINUS_EXPR, type,
3054 convert (type, integer_zero_node), 0, low, 0);
3055 low = n_low, high = n_high;
3061 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3062 convert (type, integer_one_node));
3065 case PLUS_EXPR: case MINUS_EXPR:
3066 if (TREE_CODE (arg1) != INTEGER_CST)
3069 /* If EXP is signed, any overflow in the computation is undefined,
3070 so we don't worry about it so long as our computations on
3071 the bounds don't overflow. For unsigned, overflow is defined
3072 and this is exactly the right thing. */
3073 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3074 type, low, 0, arg1, 0);
3075 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3076 type, high, 1, arg1, 0);
3077 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3078 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3081 /* Check for an unsigned range which has wrapped around the maximum
3082 value thus making n_high < n_low, and normalize it. */
3083 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3085 low = range_binop (PLUS_EXPR, type, n_high, 0,
3086 integer_one_node, 0);
3087 high = range_binop (MINUS_EXPR, type, n_low, 0,
3088 integer_one_node, 0);
3090 /* If the range is of the form +/- [ x+1, x ], we won't
3091 be able to normalize it. But then, it represents the
3092 whole range or the empty set, so make it
3094 if (tree_int_cst_equal (n_low, low)
3095 && tree_int_cst_equal (n_high, high))
3101 low = n_low, high = n_high;
3106 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3107 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3110 if (! INTEGRAL_TYPE_P (type)
3111 || (low != 0 && ! int_fits_type_p (low, type))
3112 || (high != 0 && ! int_fits_type_p (high, type)))
3115 n_low = low, n_high = high;
3118 n_low = convert (type, n_low);
3121 n_high = convert (type, n_high);
3123 /* If we're converting from an unsigned to a signed type,
3124 we will be doing the comparison as unsigned. The tests above
3125 have already verified that LOW and HIGH are both positive.
3127 So we have to make sure that the original unsigned value will
3128 be interpreted as positive. */
3129 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3131 tree equiv_type = (*lang_hooks.types.type_for_mode)
3132 (TYPE_MODE (type), 1);
3135 /* A range without an upper bound is, naturally, unbounded.
3136 Since convert would have cropped a very large value, use
3137 the max value for the destination type. */
3139 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3140 : TYPE_MAX_VALUE (type);
3142 if (TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (exp)))
3143 high_positive = fold (build (RSHIFT_EXPR, type,
3144 convert (type, high_positive),
3145 convert (type, integer_one_node)));
3147 /* If the low bound is specified, "and" the range with the
3148 range for which the original unsigned value will be
3152 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3154 1, convert (type, integer_zero_node),
3158 in_p = (n_in_p == in_p);
3162 /* Otherwise, "or" the range with the range of the input
3163 that will be interpreted as negative. */
3164 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3166 1, convert (type, integer_zero_node),
3170 in_p = (in_p != n_in_p);
3175 low = n_low, high = n_high;
3185 /* If EXP is a constant, we can evaluate whether this is true or false. */
3186 if (TREE_CODE (exp) == INTEGER_CST)
3188 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3190 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3196 *pin_p = in_p, *plow = low, *phigh = high;
3200 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3201 type, TYPE, return an expression to test if EXP is in (or out of, depending
3202 on IN_P) the range. */
3205 build_range_check (type, exp, in_p, low, high)
3211 tree etype = TREE_TYPE (exp);
3215 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3216 return invert_truthvalue (value);
3218 if (low == 0 && high == 0)
3219 return convert (type, integer_one_node);
3222 return fold (build (LE_EXPR, type, exp, high));
3225 return fold (build (GE_EXPR, type, exp, low));
3227 if (operand_equal_p (low, high, 0))
3228 return fold (build (EQ_EXPR, type, exp, low));
3230 if (integer_zerop (low))
3232 if (! TREE_UNSIGNED (etype))
3234 etype = (*lang_hooks.types.unsigned_type) (etype);
3235 high = convert (etype, high);
3236 exp = convert (etype, exp);
3238 return build_range_check (type, exp, 1, 0, high);
3241 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3242 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3244 unsigned HOST_WIDE_INT lo;
3248 prec = TYPE_PRECISION (etype);
3249 if (prec <= HOST_BITS_PER_WIDE_INT)
3252 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3256 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3257 lo = (unsigned HOST_WIDE_INT) -1;
3260 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3262 if (TREE_UNSIGNED (etype))
3264 etype = (*lang_hooks.types.signed_type) (etype);
3265 exp = convert (etype, exp);
3267 return fold (build (GT_EXPR, type, exp,
3268 convert (etype, integer_zero_node)));
3272 if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3273 && ! TREE_OVERFLOW (value))
3274 return build_range_check (type,
3275 fold (build (MINUS_EXPR, etype, exp, low)),
3276 1, convert (etype, integer_zero_node), value);
3281 /* Given two ranges, see if we can merge them into one. Return 1 if we
3282 can, 0 if we can't. Set the output range into the specified parameters. */
3285 merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
3289 tree low0, high0, low1, high1;
3297 int lowequal = ((low0 == 0 && low1 == 0)
3298 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3299 low0, 0, low1, 0)));
3300 int highequal = ((high0 == 0 && high1 == 0)
3301 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3302 high0, 1, high1, 1)));
3304 /* Make range 0 be the range that starts first, or ends last if they
3305 start at the same value. Swap them if it isn't. */
3306 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3309 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3310 high1, 1, high0, 1))))
3312 temp = in0_p, in0_p = in1_p, in1_p = temp;
3313 tem = low0, low0 = low1, low1 = tem;
3314 tem = high0, high0 = high1, high1 = tem;
3317 /* Now flag two cases, whether the ranges are disjoint or whether the
3318 second range is totally subsumed in the first. Note that the tests
3319 below are simplified by the ones above. */
3320 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3321 high0, 1, low1, 0));
3322 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3323 high1, 1, high0, 1));
3325 /* We now have four cases, depending on whether we are including or
3326 excluding the two ranges. */
3329 /* If they don't overlap, the result is false. If the second range
3330 is a subset it is the result. Otherwise, the range is from the start
3331 of the second to the end of the first. */
3333 in_p = 0, low = high = 0;
3335 in_p = 1, low = low1, high = high1;
3337 in_p = 1, low = low1, high = high0;
3340 else if (in0_p && ! in1_p)
3342 /* If they don't overlap, the result is the first range. If they are
3343 equal, the result is false. If the second range is a subset of the
3344 first, and the ranges begin at the same place, we go from just after
3345 the end of the first range to the end of the second. If the second
3346 range is not a subset of the first, or if it is a subset and both
3347 ranges end at the same place, the range starts at the start of the
3348 first range and ends just before the second range.
3349 Otherwise, we can't describe this as a single range. */
3351 in_p = 1, low = low0, high = high0;
3352 else if (lowequal && highequal)
3353 in_p = 0, low = high = 0;
3354 else if (subset && lowequal)
3356 in_p = 1, high = high0;
3357 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3358 integer_one_node, 0);
3360 else if (! subset || highequal)
3362 in_p = 1, low = low0;
3363 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3364 integer_one_node, 0);
3370 else if (! in0_p && in1_p)
3372 /* If they don't overlap, the result is the second range. If the second
3373 is a subset of the first, the result is false. Otherwise,
3374 the range starts just after the first range and ends at the
3375 end of the second. */
3377 in_p = 1, low = low1, high = high1;
3378 else if (subset || highequal)
3379 in_p = 0, low = high = 0;
3382 in_p = 1, high = high1;
3383 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3384 integer_one_node, 0);
3390 /* The case where we are excluding both ranges. Here the complex case
3391 is if they don't overlap. In that case, the only time we have a
3392 range is if they are adjacent. If the second is a subset of the
3393 first, the result is the first. Otherwise, the range to exclude
3394 starts at the beginning of the first range and ends at the end of the
3398 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3399 range_binop (PLUS_EXPR, NULL_TREE,
3401 integer_one_node, 1),
3403 in_p = 0, low = low0, high = high1;
3408 in_p = 0, low = low0, high = high0;
3410 in_p = 0, low = low0, high = high1;
3413 *pin_p = in_p, *plow = low, *phigh = high;
3417 /* EXP is some logical combination of boolean tests. See if we can
3418 merge it into some range test. Return the new tree if so. */
3421 fold_range_test (exp)
3424 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3425 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3426 int in0_p, in1_p, in_p;
3427 tree low0, low1, low, high0, high1, high;
3428 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3429 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3432 /* If this is an OR operation, invert both sides; we will invert
3433 again at the end. */
3435 in0_p = ! in0_p, in1_p = ! in1_p;
3437 /* If both expressions are the same, if we can merge the ranges, and we
3438 can build the range test, return it or it inverted. If one of the
3439 ranges is always true or always false, consider it to be the same
3440 expression as the other. */
3441 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3442 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3444 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3446 : rhs != 0 ? rhs : integer_zero_node,
3448 return or_op ? invert_truthvalue (tem) : tem;
3450 /* On machines where the branch cost is expensive, if this is a
3451 short-circuited branch and the underlying object on both sides
3452 is the same, make a non-short-circuit operation. */
3453 else if (BRANCH_COST >= 2
3454 && lhs != 0 && rhs != 0
3455 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3456 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3457 && operand_equal_p (lhs, rhs, 0))
3459 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3460 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3461 which cases we can't do this. */
3462 if (simple_operand_p (lhs))
3463 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3464 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3465 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3466 TREE_OPERAND (exp, 1));
3468 else if ((*lang_hooks.decls.global_bindings_p) () == 0
3469 && ! contains_placeholder_p (lhs))
3471 tree common = save_expr (lhs);
3473 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3474 or_op ? ! in0_p : in0_p,
3476 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3477 or_op ? ! in1_p : in1_p,
3479 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3480 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3481 TREE_TYPE (exp), lhs, rhs);
3488 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3489 bit value. Arrange things so the extra bits will be set to zero if and
3490 only if C is signed-extended to its full width. If MASK is nonzero,
3491 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3494 unextend (c, p, unsignedp, mask)
3500 tree type = TREE_TYPE (c);
3501 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3504 if (p == modesize || unsignedp)
3507 /* We work by getting just the sign bit into the low-order bit, then
3508 into the high-order bit, then sign-extend. We then XOR that value
3510 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3511 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3513 /* We must use a signed type in order to get an arithmetic right shift.
3514 However, we must also avoid introducing accidental overflows, so that
3515 a subsequent call to integer_zerop will work. Hence we must
3516 do the type conversion here. At this point, the constant is either
3517 zero or one, and the conversion to a signed type can never overflow.
3518 We could get an overflow if this conversion is done anywhere else. */
3519 if (TREE_UNSIGNED (type))
3520 temp = convert ((*lang_hooks.types.signed_type) (type), temp);
3522 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3523 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3525 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3526 /* If necessary, convert the type back to match the type of C. */
3527 if (TREE_UNSIGNED (type))
3528 temp = convert (type, temp);
3530 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3533 /* Find ways of folding logical expressions of LHS and RHS:
3534 Try to merge two comparisons to the same innermost item.
3535 Look for range tests like "ch >= '0' && ch <= '9'".
3536 Look for combinations of simple terms on machines with expensive branches
3537 and evaluate the RHS unconditionally.
3539 For example, if we have p->a == 2 && p->b == 4 and we can make an
3540 object large enough to span both A and B, we can do this with a comparison
3541 against the object ANDed with the a mask.
3543 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3544 operations to do this with one comparison.
3546 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3547 function and the one above.
3549 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3550 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3552 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3555 We return the simplified tree or 0 if no optimization is possible. */
3558 fold_truthop (code, truth_type, lhs, rhs)
3559 enum tree_code code;
3560 tree truth_type, lhs, rhs;
3562 /* If this is the "or" of two comparisons, we can do something if
3563 the comparisons are NE_EXPR. If this is the "and", we can do something
3564 if the comparisons are EQ_EXPR. I.e.,
3565 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3567 WANTED_CODE is this operation code. For single bit fields, we can
3568 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3569 comparison for one-bit fields. */
3571 enum tree_code wanted_code;
3572 enum tree_code lcode, rcode;
3573 tree ll_arg, lr_arg, rl_arg, rr_arg;
3574 tree ll_inner, lr_inner, rl_inner, rr_inner;
3575 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3576 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3577 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3578 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3579 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3580 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3581 enum machine_mode lnmode, rnmode;
3582 tree ll_mask, lr_mask, rl_mask, rr_mask;
3583 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3584 tree l_const, r_const;
3585 tree lntype, rntype, result;
3586 int first_bit, end_bit;
3589 /* Start by getting the comparison codes. Fail if anything is volatile.
3590 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3591 it were surrounded with a NE_EXPR. */
3593 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3596 lcode = TREE_CODE (lhs);
3597 rcode = TREE_CODE (rhs);
3599 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3600 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3602 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3603 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3605 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3608 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3609 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3611 ll_arg = TREE_OPERAND (lhs, 0);
3612 lr_arg = TREE_OPERAND (lhs, 1);
3613 rl_arg = TREE_OPERAND (rhs, 0);
3614 rr_arg = TREE_OPERAND (rhs, 1);
3616 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
3617 if (simple_operand_p (ll_arg)
3618 && simple_operand_p (lr_arg)
3619 && !FLOAT_TYPE_P (TREE_TYPE (ll_arg)))
3623 if (operand_equal_p (ll_arg, rl_arg, 0)
3624 && operand_equal_p (lr_arg, rr_arg, 0))
3626 int lcompcode, rcompcode;
3628 lcompcode = comparison_to_compcode (lcode);
3629 rcompcode = comparison_to_compcode (rcode);
3630 compcode = (code == TRUTH_AND_EXPR)
3631 ? lcompcode & rcompcode
3632 : lcompcode | rcompcode;
3634 else if (operand_equal_p (ll_arg, rr_arg, 0)
3635 && operand_equal_p (lr_arg, rl_arg, 0))
3637 int lcompcode, rcompcode;
3639 rcode = swap_tree_comparison (rcode);
3640 lcompcode = comparison_to_compcode (lcode);
3641 rcompcode = comparison_to_compcode (rcode);
3642 compcode = (code == TRUTH_AND_EXPR)
3643 ? lcompcode & rcompcode
3644 : lcompcode | rcompcode;
3649 if (compcode == COMPCODE_TRUE)
3650 return convert (truth_type, integer_one_node);
3651 else if (compcode == COMPCODE_FALSE)
3652 return convert (truth_type, integer_zero_node);
3653 else if (compcode != -1)
3654 return build (compcode_to_comparison (compcode),
3655 truth_type, ll_arg, lr_arg);
3658 /* If the RHS can be evaluated unconditionally and its operands are
3659 simple, it wins to evaluate the RHS unconditionally on machines
3660 with expensive branches. In this case, this isn't a comparison
3661 that can be merged. Avoid doing this if the RHS is a floating-point
3662 comparison since those can trap. */
3664 if (BRANCH_COST >= 2
3665 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
3666 && simple_operand_p (rl_arg)
3667 && simple_operand_p (rr_arg))
3669 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
3670 if (code == TRUTH_OR_EXPR
3671 && lcode == NE_EXPR && integer_zerop (lr_arg)
3672 && rcode == NE_EXPR && integer_zerop (rr_arg)
3673 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
3674 return build (NE_EXPR, truth_type,
3675 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
3679 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
3680 if (code == TRUTH_AND_EXPR
3681 && lcode == EQ_EXPR && integer_zerop (lr_arg)
3682 && rcode == EQ_EXPR && integer_zerop (rr_arg)
3683 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
3684 return build (EQ_EXPR, truth_type,
3685 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
3689 return build (code, truth_type, lhs, rhs);
3692 /* See if the comparisons can be merged. Then get all the parameters for
3695 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3696 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3700 ll_inner = decode_field_reference (ll_arg,
3701 &ll_bitsize, &ll_bitpos, &ll_mode,
3702 &ll_unsignedp, &volatilep, &ll_mask,
3704 lr_inner = decode_field_reference (lr_arg,
3705 &lr_bitsize, &lr_bitpos, &lr_mode,
3706 &lr_unsignedp, &volatilep, &lr_mask,
3708 rl_inner = decode_field_reference (rl_arg,
3709 &rl_bitsize, &rl_bitpos, &rl_mode,
3710 &rl_unsignedp, &volatilep, &rl_mask,
3712 rr_inner = decode_field_reference (rr_arg,
3713 &rr_bitsize, &rr_bitpos, &rr_mode,
3714 &rr_unsignedp, &volatilep, &rr_mask,
3717 /* It must be true that the inner operation on the lhs of each
3718 comparison must be the same if we are to be able to do anything.
3719 Then see if we have constants. If not, the same must be true for
3721 if (volatilep || ll_inner == 0 || rl_inner == 0
3722 || ! operand_equal_p (ll_inner, rl_inner, 0))
3725 if (TREE_CODE (lr_arg) == INTEGER_CST
3726 && TREE_CODE (rr_arg) == INTEGER_CST)
3727 l_const = lr_arg, r_const = rr_arg;
3728 else if (lr_inner == 0 || rr_inner == 0
3729 || ! operand_equal_p (lr_inner, rr_inner, 0))
3732 l_const = r_const = 0;
3734 /* If either comparison code is not correct for our logical operation,
3735 fail. However, we can convert a one-bit comparison against zero into
3736 the opposite comparison against that bit being set in the field. */
3738 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
3739 if (lcode != wanted_code)
3741 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
3743 /* Make the left operand unsigned, since we are only interested
3744 in the value of one bit. Otherwise we are doing the wrong
3753 /* This is analogous to the code for l_const above. */
3754 if (rcode != wanted_code)
3756 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
3765 /* After this point all optimizations will generate bit-field
3766 references, which we might not want. */
3767 if (! (*lang_hooks.can_use_bit_fields_p) ())
3770 /* See if we can find a mode that contains both fields being compared on
3771 the left. If we can't, fail. Otherwise, update all constants and masks
3772 to be relative to a field of that size. */
3773 first_bit = MIN (ll_bitpos, rl_bitpos);
3774 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
3775 lnmode = get_best_mode (end_bit - first_bit, first_bit,
3776 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
3778 if (lnmode == VOIDmode)
3781 lnbitsize = GET_MODE_BITSIZE (lnmode);
3782 lnbitpos = first_bit & ~ (lnbitsize - 1);
3783 lntype = (*lang_hooks.types.type_for_size) (lnbitsize, 1);
3784 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
3786 if (BYTES_BIG_ENDIAN)
3788 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
3789 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
3792 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
3793 size_int (xll_bitpos), 0);
3794 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
3795 size_int (xrl_bitpos), 0);
3799 l_const = convert (lntype, l_const);
3800 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
3801 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
3802 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
3803 fold (build1 (BIT_NOT_EXPR,
3807 warning ("comparison is always %d", wanted_code == NE_EXPR);
3809 return convert (truth_type,
3810 wanted_code == NE_EXPR
3811 ? integer_one_node : integer_zero_node);
3816 r_const = convert (lntype, r_const);
3817 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
3818 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
3819 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
3820 fold (build1 (BIT_NOT_EXPR,
3824 warning ("comparison is always %d", wanted_code == NE_EXPR);
3826 return convert (truth_type,
3827 wanted_code == NE_EXPR
3828 ? integer_one_node : integer_zero_node);
3832 /* If the right sides are not constant, do the same for it. Also,
3833 disallow this optimization if a size or signedness mismatch occurs
3834 between the left and right sides. */
3837 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
3838 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
3839 /* Make sure the two fields on the right
3840 correspond to the left without being swapped. */
3841 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
3844 first_bit = MIN (lr_bitpos, rr_bitpos);
3845 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
3846 rnmode = get_best_mode (end_bit - first_bit, first_bit,
3847 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
3849 if (rnmode == VOIDmode)
3852 rnbitsize = GET_MODE_BITSIZE (rnmode);
3853 rnbitpos = first_bit & ~ (rnbitsize - 1);
3854 rntype = (*lang_hooks.types.type_for_size) (rnbitsize, 1);
3855 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
3857 if (BYTES_BIG_ENDIAN)
3859 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
3860 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
3863 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
3864 size_int (xlr_bitpos), 0);
3865 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
3866 size_int (xrr_bitpos), 0);
3868 /* Make a mask that corresponds to both fields being compared.
3869 Do this for both items being compared. If the operands are the
3870 same size and the bits being compared are in the same position
3871 then we can do this by masking both and comparing the masked
3873 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3874 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
3875 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
3877 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
3878 ll_unsignedp || rl_unsignedp);
3879 if (! all_ones_mask_p (ll_mask, lnbitsize))
3880 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
3882 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
3883 lr_unsignedp || rr_unsignedp);
3884 if (! all_ones_mask_p (lr_mask, rnbitsize))
3885 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
3887 return build (wanted_code, truth_type, lhs, rhs);
3890 /* There is still another way we can do something: If both pairs of
3891 fields being compared are adjacent, we may be able to make a wider
3892 field containing them both.
3894 Note that we still must mask the lhs/rhs expressions. Furthermore,
3895 the mask must be shifted to account for the shift done by
3896 make_bit_field_ref. */
3897 if ((ll_bitsize + ll_bitpos == rl_bitpos
3898 && lr_bitsize + lr_bitpos == rr_bitpos)
3899 || (ll_bitpos == rl_bitpos + rl_bitsize
3900 && lr_bitpos == rr_bitpos + rr_bitsize))
3904 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
3905 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
3906 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
3907 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
3909 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
3910 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
3911 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
3912 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
3914 /* Convert to the smaller type before masking out unwanted bits. */
3916 if (lntype != rntype)
3918 if (lnbitsize > rnbitsize)
3920 lhs = convert (rntype, lhs);
3921 ll_mask = convert (rntype, ll_mask);
3924 else if (lnbitsize < rnbitsize)
3926 rhs = convert (lntype, rhs);
3927 lr_mask = convert (lntype, lr_mask);
3932 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
3933 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
3935 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
3936 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
3938 return build (wanted_code, truth_type, lhs, rhs);
3944 /* Handle the case of comparisons with constants. If there is something in
3945 common between the masks, those bits of the constants must be the same.
3946 If not, the condition is always false. Test for this to avoid generating
3947 incorrect code below. */
3948 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
3949 if (! integer_zerop (result)
3950 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
3951 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
3953 if (wanted_code == NE_EXPR)
3955 warning ("`or' of unmatched not-equal tests is always 1");
3956 return convert (truth_type, integer_one_node);
3960 warning ("`and' of mutually exclusive equal-tests is always 0");
3961 return convert (truth_type, integer_zero_node);
3965 /* Construct the expression we will return. First get the component
3966 reference we will make. Unless the mask is all ones the width of
3967 that field, perform the mask operation. Then compare with the
3969 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
3970 ll_unsignedp || rl_unsignedp);
3972 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3973 if (! all_ones_mask_p (ll_mask, lnbitsize))
3974 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
3976 return build (wanted_code, truth_type, result,
3977 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
3980 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
3984 optimize_minmax_comparison (t)
3987 tree type = TREE_TYPE (t);
3988 tree arg0 = TREE_OPERAND (t, 0);
3989 enum tree_code op_code;
3990 tree comp_const = TREE_OPERAND (t, 1);
3992 int consts_equal, consts_lt;
3995 STRIP_SIGN_NOPS (arg0);
3997 op_code = TREE_CODE (arg0);
3998 minmax_const = TREE_OPERAND (arg0, 1);
3999 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4000 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4001 inner = TREE_OPERAND (arg0, 0);
4003 /* If something does not permit us to optimize, return the original tree. */
4004 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4005 || TREE_CODE (comp_const) != INTEGER_CST
4006 || TREE_CONSTANT_OVERFLOW (comp_const)
4007 || TREE_CODE (minmax_const) != INTEGER_CST
4008 || TREE_CONSTANT_OVERFLOW (minmax_const))
4011 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4012 and GT_EXPR, doing the rest with recursive calls using logical
4014 switch (TREE_CODE (t))
4016 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4018 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4022 fold (build (TRUTH_ORIF_EXPR, type,
4023 optimize_minmax_comparison
4024 (build (EQ_EXPR, type, arg0, comp_const)),
4025 optimize_minmax_comparison
4026 (build (GT_EXPR, type, arg0, comp_const))));
4029 if (op_code == MAX_EXPR && consts_equal)
4030 /* MAX (X, 0) == 0 -> X <= 0 */
4031 return fold (build (LE_EXPR, type, inner, comp_const));
4033 else if (op_code == MAX_EXPR && consts_lt)
4034 /* MAX (X, 0) == 5 -> X == 5 */
4035 return fold (build (EQ_EXPR, type, inner, comp_const));
4037 else if (op_code == MAX_EXPR)
4038 /* MAX (X, 0) == -1 -> false */
4039 return omit_one_operand (type, integer_zero_node, inner);
4041 else if (consts_equal)
4042 /* MIN (X, 0) == 0 -> X >= 0 */
4043 return fold (build (GE_EXPR, type, inner, comp_const));
4046 /* MIN (X, 0) == 5 -> false */
4047 return omit_one_operand (type, integer_zero_node, inner);
4050 /* MIN (X, 0) == -1 -> X == -1 */
4051 return fold (build (EQ_EXPR, type, inner, comp_const));
4054 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4055 /* MAX (X, 0) > 0 -> X > 0
4056 MAX (X, 0) > 5 -> X > 5 */
4057 return fold (build (GT_EXPR, type, inner, comp_const));
4059 else if (op_code == MAX_EXPR)
4060 /* MAX (X, 0) > -1 -> true */
4061 return omit_one_operand (type, integer_one_node, inner);
4063 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4064 /* MIN (X, 0) > 0 -> false
4065 MIN (X, 0) > 5 -> false */
4066 return omit_one_operand (type, integer_zero_node, inner);
4069 /* MIN (X, 0) > -1 -> X > -1 */
4070 return fold (build (GT_EXPR, type, inner, comp_const));
4077 /* T is an integer expression that is being multiplied, divided, or taken a
4078 modulus (CODE says which and what kind of divide or modulus) by a
4079 constant C. See if we can eliminate that operation by folding it with
4080 other operations already in T. WIDE_TYPE, if non-null, is a type that
4081 should be used for the computation if wider than our type.
4083 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4084 (X * 2) + (Y * 4). We must, however, be assured that either the original
4085 expression would not overflow or that overflow is undefined for the type
4086 in the language in question.
4088 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4089 the machine has a multiply-accumulate insn or that this is part of an
4090 addressing calculation.
4092 If we return a non-null expression, it is an equivalent form of the
4093 original computation, but need not be in the original type. */
4096 extract_muldiv (t, c, code, wide_type)
4099 enum tree_code code;
4102 /* To avoid exponential search depth, refuse to allow recursion past
4103 three levels. Beyond that (1) it's highly unlikely that we'll find
4104 something interesting and (2) we've probably processed it before
4105 when we built the inner expression. */
4114 ret = extract_muldiv_1 (t, c, code, wide_type);
4121 extract_muldiv_1 (t, c, code, wide_type)
4124 enum tree_code code;
4127 tree type = TREE_TYPE (t);
4128 enum tree_code tcode = TREE_CODE (t);
4129 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4130 > GET_MODE_SIZE (TYPE_MODE (type)))
4131 ? wide_type : type);
4133 int same_p = tcode == code;
4134 tree op0 = NULL_TREE, op1 = NULL_TREE;
4136 /* Don't deal with constants of zero here; they confuse the code below. */
4137 if (integer_zerop (c))
4140 if (TREE_CODE_CLASS (tcode) == '1')
4141 op0 = TREE_OPERAND (t, 0);
4143 if (TREE_CODE_CLASS (tcode) == '2')
4144 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4146 /* Note that we need not handle conditional operations here since fold
4147 already handles those cases. So just do arithmetic here. */
4151 /* For a constant, we can always simplify if we are a multiply
4152 or (for divide and modulus) if it is a multiple of our constant. */
4153 if (code == MULT_EXPR
4154 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4155 return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
4158 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4159 /* If op0 is an expression ... */
4160 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
4161 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
4162 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
4163 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
4164 /* ... and is unsigned, and its type is smaller than ctype,
4165 then we cannot pass through as widening. */
4166 && ((TREE_UNSIGNED (TREE_TYPE (op0))
4167 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
4168 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
4169 && (GET_MODE_SIZE (TYPE_MODE (ctype))
4170 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
4171 /* ... or its type is larger than ctype,
4172 then we cannot pass through this truncation. */
4173 || (GET_MODE_SIZE (TYPE_MODE (ctype))
4174 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
4175 /* ... or signedness changes for division or modulus,
4176 then we cannot pass through this conversion. */
4177 || (code != MULT_EXPR
4178 && (TREE_UNSIGNED (ctype)
4179 != TREE_UNSIGNED (TREE_TYPE (op0))))))
4182 /* Pass the constant down and see if we can make a simplification. If
4183 we can, replace this expression with the inner simplification for
4184 possible later conversion to our or some other type. */
4185 if (0 != (t1 = extract_muldiv (op0, convert (TREE_TYPE (op0), c), code,
4186 code == MULT_EXPR ? ctype : NULL_TREE)))
4190 case NEGATE_EXPR: case ABS_EXPR:
4191 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4192 return fold (build1 (tcode, ctype, convert (ctype, t1)));
4195 case MIN_EXPR: case MAX_EXPR:
4196 /* If widening the type changes the signedness, then we can't perform
4197 this optimization as that changes the result. */
4198 if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
4201 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4202 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4203 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4205 if (tree_int_cst_sgn (c) < 0)
4206 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4208 return fold (build (tcode, ctype, convert (ctype, t1),
4209 convert (ctype, t2)));
4213 case WITH_RECORD_EXPR:
4214 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4215 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4216 TREE_OPERAND (t, 1));
4220 /* If this has not been evaluated and the operand has no side effects,
4221 we can see if we can do something inside it and make a new one.
4222 Note that this test is overly conservative since we can do this
4223 if the only reason it had side effects is that it was another
4224 similar SAVE_EXPR, but that isn't worth bothering with. */
4225 if (SAVE_EXPR_RTL (t) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
4226 && 0 != (t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code,
4229 t1 = save_expr (t1);
4230 if (SAVE_EXPR_PERSISTENT_P (t) && TREE_CODE (t1) == SAVE_EXPR)
4231 SAVE_EXPR_PERSISTENT_P (t1) = 1;
4232 if (is_pending_size (t))
4233 put_pending_size (t1);
4238 case LSHIFT_EXPR: case RSHIFT_EXPR:
4239 /* If the second operand is constant, this is a multiplication
4240 or floor division, by a power of two, so we can treat it that
4241 way unless the multiplier or divisor overflows. */
4242 if (TREE_CODE (op1) == INTEGER_CST
4243 /* const_binop may not detect overflow correctly,
4244 so check for it explicitly here. */
4245 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
4246 && TREE_INT_CST_HIGH (op1) == 0
4247 && 0 != (t1 = convert (ctype,
4248 const_binop (LSHIFT_EXPR, size_one_node,
4250 && ! TREE_OVERFLOW (t1))
4251 return extract_muldiv (build (tcode == LSHIFT_EXPR
4252 ? MULT_EXPR : FLOOR_DIV_EXPR,
4253 ctype, convert (ctype, op0), t1),
4254 c, code, wide_type);
4257 case PLUS_EXPR: case MINUS_EXPR:
4258 /* See if we can eliminate the operation on both sides. If we can, we
4259 can return a new PLUS or MINUS. If we can't, the only remaining
4260 cases where we can do anything are if the second operand is a
4262 t1 = extract_muldiv (op0, c, code, wide_type);
4263 t2 = extract_muldiv (op1, c, code, wide_type);
4264 if (t1 != 0 && t2 != 0
4265 && (code == MULT_EXPR
4266 /* If not multiplication, we can only do this if both operands
4267 are divisible by c. */
4268 || (multiple_of_p (ctype, op0, c)
4269 && multiple_of_p (ctype, op1, c))))
4270 return fold (build (tcode, ctype, convert (ctype, t1),
4271 convert (ctype, t2)));
4273 /* If this was a subtraction, negate OP1 and set it to be an addition.
4274 This simplifies the logic below. */
4275 if (tcode == MINUS_EXPR)
4276 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4278 if (TREE_CODE (op1) != INTEGER_CST)
4281 /* If either OP1 or C are negative, this optimization is not safe for
4282 some of the division and remainder types while for others we need
4283 to change the code. */
4284 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4286 if (code == CEIL_DIV_EXPR)
4287 code = FLOOR_DIV_EXPR;
4288 else if (code == FLOOR_DIV_EXPR)
4289 code = CEIL_DIV_EXPR;
4290 else if (code != MULT_EXPR
4291 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
4295 /* If it's a multiply or a division/modulus operation of a multiple
4296 of our constant, do the operation and verify it doesn't overflow. */
4297 if (code == MULT_EXPR
4298 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4300 op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
4301 if (op1 == 0 || TREE_OVERFLOW (op1))
4307 /* If we have an unsigned type is not a sizetype, we cannot widen
4308 the operation since it will change the result if the original
4309 computation overflowed. */
4310 if (TREE_UNSIGNED (ctype)
4311 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
4315 /* If we were able to eliminate our operation from the first side,
4316 apply our operation to the second side and reform the PLUS. */
4317 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4318 return fold (build (tcode, ctype, convert (ctype, t1), op1));
4320 /* The last case is if we are a multiply. In that case, we can
4321 apply the distributive law to commute the multiply and addition
4322 if the multiplication of the constants doesn't overflow. */
4323 if (code == MULT_EXPR)
4324 return fold (build (tcode, ctype, fold (build (code, ctype,
4325 convert (ctype, op0),
4326 convert (ctype, c))),
4332 /* We have a special case here if we are doing something like
4333 (C * 8) % 4 since we know that's zero. */
4334 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4335 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4336 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4337 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4338 return omit_one_operand (type, integer_zero_node, op0);
4340 /* ... fall through ... */
4342 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4343 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4344 /* If we can extract our operation from the LHS, do so and return a
4345 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4346 do something only if the second operand is a constant. */
4348 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4349 return fold (build (tcode, ctype, convert (ctype, t1),
4350 convert (ctype, op1)));
4351 else if (tcode == MULT_EXPR && code == MULT_EXPR
4352 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4353 return fold (build (tcode, ctype, convert (ctype, op0),
4354 convert (ctype, t1)));
4355 else if (TREE_CODE (op1) != INTEGER_CST)
4358 /* If these are the same operation types, we can associate them
4359 assuming no overflow. */
4361 && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
4362 convert (ctype, c), 0))
4363 && ! TREE_OVERFLOW (t1))
4364 return fold (build (tcode, ctype, convert (ctype, op0), t1));
4366 /* If these operations "cancel" each other, we have the main
4367 optimizations of this pass, which occur when either constant is a
4368 multiple of the other, in which case we replace this with either an
4369 operation or CODE or TCODE.
4371 If we have an unsigned type that is not a sizetype, we cannot do
4372 this since it will change the result if the original computation
4374 if ((! TREE_UNSIGNED (ctype)
4375 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
4376 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4377 || (tcode == MULT_EXPR
4378 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4379 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
4381 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4382 return fold (build (tcode, ctype, convert (ctype, op0),
4384 const_binop (TRUNC_DIV_EXPR,
4386 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4387 return fold (build (code, ctype, convert (ctype, op0),
4389 const_binop (TRUNC_DIV_EXPR,
4401 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4402 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4403 that we may sometimes modify the tree. */
4406 strip_compound_expr (t, s)
4410 enum tree_code code = TREE_CODE (t);
4412 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4413 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4414 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4415 return TREE_OPERAND (t, 1);
4417 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4418 don't bother handling any other types. */
4419 else if (code == COND_EXPR)
4421 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4422 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4423 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4425 else if (TREE_CODE_CLASS (code) == '1')
4426 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4427 else if (TREE_CODE_CLASS (code) == '<'
4428 || TREE_CODE_CLASS (code) == '2')
4430 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4431 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4437 /* Return a node which has the indicated constant VALUE (either 0 or
4438 1), and is of the indicated TYPE. */
4441 constant_boolean_node (value, type)
4445 if (type == integer_type_node)
4446 return value ? integer_one_node : integer_zero_node;
4447 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4448 return (*lang_hooks.truthvalue_conversion) (value ? integer_one_node :
4452 tree t = build_int_2 (value, 0);
4454 TREE_TYPE (t) = type;
4459 /* Utility function for the following routine, to see how complex a nesting of
4460 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4461 we don't care (to avoid spending too much time on complex expressions.). */
4464 count_cond (expr, lim)
4470 if (TREE_CODE (expr) != COND_EXPR)
4475 ctrue = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4476 cfalse = count_cond (TREE_OPERAND (expr, 2), lim - 1 - ctrue);
4477 return MIN (lim, 1 + ctrue + cfalse);
4480 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
4481 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4482 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4483 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
4484 COND is the first argument to CODE; otherwise (as in the example
4485 given here), it is the second argument. TYPE is the type of the
4486 original expression. */
4489 fold_binary_op_with_conditional_arg (code, type, cond, arg, cond_first_p)
4490 enum tree_code code;
4496 tree test, true_value, false_value;
4497 tree lhs = NULL_TREE;
4498 tree rhs = NULL_TREE;
4499 /* In the end, we'll produce a COND_EXPR. Both arms of the
4500 conditional expression will be binary operations. The left-hand
4501 side of the expression to be executed if the condition is true
4502 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4503 of the expression to be executed if the condition is true will be
4504 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4505 but apply to the expression to be executed if the conditional is
4511 /* These are the codes to use for the left-hand side and right-hand
4512 side of the COND_EXPR. Normally, they are the same as CODE. */
4513 enum tree_code lhs_code = code;
4514 enum tree_code rhs_code = code;
4515 /* And these are the types of the expressions. */
4516 tree lhs_type = type;
4517 tree rhs_type = type;
4522 true_rhs = false_rhs = &arg;
4523 true_lhs = &true_value;
4524 false_lhs = &false_value;
4528 true_lhs = false_lhs = &arg;
4529 true_rhs = &true_value;
4530 false_rhs = &false_value;
4533 if (TREE_CODE (cond) == COND_EXPR)
4535 test = TREE_OPERAND (cond, 0);
4536 true_value = TREE_OPERAND (cond, 1);
4537 false_value = TREE_OPERAND (cond, 2);
4538 /* If this operand throws an expression, then it does not make
4539 sense to try to perform a logical or arithmetic operation
4540 involving it. Instead of building `a + throw 3' for example,
4541 we simply build `a, throw 3'. */
4542 if (VOID_TYPE_P (TREE_TYPE (true_value)))
4546 lhs_code = COMPOUND_EXPR;
4547 lhs_type = void_type_node;
4552 if (VOID_TYPE_P (TREE_TYPE (false_value)))
4556 rhs_code = COMPOUND_EXPR;
4557 rhs_type = void_type_node;
4565 tree testtype = TREE_TYPE (cond);
4567 true_value = convert (testtype, integer_one_node);
4568 false_value = convert (testtype, integer_zero_node);
4571 /* If ARG is complex we want to make sure we only evaluate
4572 it once. Though this is only required if it is volatile, it
4573 might be more efficient even if it is not. However, if we
4574 succeed in folding one part to a constant, we do not need
4575 to make this SAVE_EXPR. Since we do this optimization
4576 primarily to see if we do end up with constant and this
4577 SAVE_EXPR interferes with later optimizations, suppressing
4578 it when we can is important.
4580 If we are not in a function, we can't make a SAVE_EXPR, so don't
4581 try to do so. Don't try to see if the result is a constant
4582 if an arm is a COND_EXPR since we get exponential behavior
4585 if (TREE_CODE (arg) == SAVE_EXPR)
4587 else if (lhs == 0 && rhs == 0
4588 && !TREE_CONSTANT (arg)
4589 && (*lang_hooks.decls.global_bindings_p) () == 0
4590 && ((TREE_CODE (arg) != VAR_DECL && TREE_CODE (arg) != PARM_DECL)
4591 || TREE_SIDE_EFFECTS (arg)))
4593 if (TREE_CODE (true_value) != COND_EXPR)
4594 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4596 if (TREE_CODE (false_value) != COND_EXPR)
4597 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4599 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4600 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4602 arg = save_expr (arg);
4609 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4611 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4613 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4616 return build (COMPOUND_EXPR, type,
4617 convert (void_type_node, arg),
4618 strip_compound_expr (test, arg));
4620 return convert (type, test);
4624 /* Subroutine of fold() that checks for the addition of +/- 0.0.
4626 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
4627 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
4628 ADDEND is the same as X.
4630 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
4631 and finite. The problematic cases are when X is zero, and its mode
4632 has signed zeros. In the case of rounding towards -infinity,
4633 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
4634 modes, X + 0 is not the same as X because -0 + 0 is 0. */
4637 fold_real_zero_addition_p (type, addend, negate)
4641 if (!real_zerop (addend))
4644 /* Don't allow the fold with -fsignaling-nans. */
4645 if (HONOR_SNANS (TYPE_MODE (type)))
4648 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
4649 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
4652 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
4653 if (TREE_CODE (addend) == REAL_CST
4654 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
4657 /* The mode has signed zeros, and we have to honor their sign.
4658 In this situation, there is only one case we can return true for.
4659 X - 0 is the same as X unless rounding towards -infinity is
4661 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
4664 /* Subroutine of fold() that checks comparisons of built-in math
4665 functions against real constants.
4667 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
4668 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
4669 is the type of the result and ARG0 and ARG1 are the operands of the
4670 comparison. ARG1 must be a TREE_REAL_CST.
4672 The function returns the constant folded tree if a simplification
4673 can be made, and NULL_TREE otherwise. */
4676 fold_mathfn_compare (fcode, code, type, arg0, arg1)
4677 enum built_in_function fcode;
4678 enum tree_code code;
4679 tree type, arg0, arg1;
4683 if (fcode == BUILT_IN_SQRT
4684 || fcode == BUILT_IN_SQRTF
4685 || fcode == BUILT_IN_SQRTL)
4687 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
4688 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
4690 c = TREE_REAL_CST (arg1);
4691 if (REAL_VALUE_NEGATIVE (c))
4693 /* sqrt(x) < y is always false, if y is negative. */
4694 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
4695 return omit_one_operand (type,
4696 convert (type, integer_zero_node),
4699 /* sqrt(x) > y is always true, if y is negative and we
4700 don't care about NaNs, i.e. negative values of x. */
4701 if (code == NE_EXPR || !HONOR_NANS (mode))
4702 return omit_one_operand (type,
4703 convert (type, integer_one_node),
4706 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
4707 return fold (build (GE_EXPR, type, arg,
4708 build_real (TREE_TYPE (arg), dconst0)));
4710 else if (code == GT_EXPR || code == GE_EXPR)
4714 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
4715 real_convert (&c2, mode, &c2);
4717 if (REAL_VALUE_ISINF (c2))
4719 /* sqrt(x) > y is x == +Inf, when y is very large. */
4720 if (HONOR_INFINITIES (mode))
4721 return fold (build (EQ_EXPR, type, arg,
4722 build_real (TREE_TYPE (arg), c2)));
4724 /* sqrt(x) > y is always false, when y is very large
4725 and we don't care about infinities. */
4726 return omit_one_operand (type,
4727 convert (type, integer_zero_node),
4731 /* sqrt(x) > c is the same as x > c*c. */
4732 return fold (build (code, type, arg,
4733 build_real (TREE_TYPE (arg), c2)));
4735 else if (code == LT_EXPR || code == LE_EXPR)
4739 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
4740 real_convert (&c2, mode, &c2);
4742 if (REAL_VALUE_ISINF (c2))
4744 /* sqrt(x) < y is always true, when y is a very large
4745 value and we don't care about NaNs or Infinities. */
4746 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
4747 return omit_one_operand (type,
4748 convert (type, integer_one_node),
4751 /* sqrt(x) < y is x != +Inf when y is very large and we
4752 don't care about NaNs. */
4753 if (! HONOR_NANS (mode))
4754 return fold (build (NE_EXPR, type, arg,
4755 build_real (TREE_TYPE (arg), c2)));
4757 /* sqrt(x) < y is x >= 0 when y is very large and we
4758 don't care about Infinities. */
4759 if (! HONOR_INFINITIES (mode))
4760 return fold (build (GE_EXPR, type, arg,
4761 build_real (TREE_TYPE (arg), dconst0)));
4763 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
4764 if ((*lang_hooks.decls.global_bindings_p) () != 0
4765 || contains_placeholder_p (arg))
4768 arg = save_expr (arg);
4769 return fold (build (TRUTH_ANDIF_EXPR, type,
4770 fold (build (GE_EXPR, type, arg,
4771 build_real (TREE_TYPE (arg),
4773 fold (build (NE_EXPR, type, arg,
4774 build_real (TREE_TYPE (arg),
4778 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
4779 if (! HONOR_NANS (mode))
4780 return fold (build (code, type, arg,
4781 build_real (TREE_TYPE (arg), c2)));
4783 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
4784 if ((*lang_hooks.decls.global_bindings_p) () == 0
4785 && ! contains_placeholder_p (arg))
4787 arg = save_expr (arg);
4788 return fold (build (TRUTH_ANDIF_EXPR, type,
4789 fold (build (GE_EXPR, type, arg,
4790 build_real (TREE_TYPE (arg),
4792 fold (build (code, type, arg,
4793 build_real (TREE_TYPE (arg),
4802 /* Subroutine of fold() that optimizes comparisons against Infinities,
4803 either +Inf or -Inf.
4805 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
4806 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
4807 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
4809 The function returns the constant folded tree if a simplification
4810 can be made, and NULL_TREE otherwise. */
4813 fold_inf_compare (code, type, arg0, arg1)
4814 enum tree_code code;
4815 tree type, arg0, arg1;
4817 /* For negative infinity swap the sense of the comparison. */
4818 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
4819 code = swap_tree_comparison (code);
4824 /* x > +Inf is always false, if with ignore sNANs. */
4825 if (HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
4827 return omit_one_operand (type,
4828 convert (type, integer_zero_node),
4832 /* x <= +Inf is always true, if we don't case about NaNs. */
4833 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
4834 return omit_one_operand (type,
4835 convert (type, integer_one_node),
4838 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
4839 if ((*lang_hooks.decls.global_bindings_p) () == 0
4840 && ! contains_placeholder_p (arg0))
4842 arg0 = save_expr (arg0);
4843 return fold (build (EQ_EXPR, type, arg0, arg0));
4847 case EQ_EXPR: /* ??? x == +Inf is x > DBL_MAX */
4848 case GE_EXPR: /* ??? x >= +Inf is x > DBL_MAX */
4849 case LT_EXPR: /* ??? x < +Inf is x <= DBL_MAX */
4850 case NE_EXPR: /* ??? x != +Inf is !(x > DBL_MAX) */
4859 /* Perform constant folding and related simplification of EXPR.
4860 The related simplifications include x*1 => x, x*0 => 0, etc.,
4861 and application of the associative law.
4862 NOP_EXPR conversions may be removed freely (as long as we
4863 are careful not to change the C type of the overall expression)
4864 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4865 but we can constant-fold them if they have constant operands. */
4872 tree t1 = NULL_TREE;
4874 tree type = TREE_TYPE (expr);
4875 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4876 enum tree_code code = TREE_CODE (t);
4877 int kind = TREE_CODE_CLASS (code);
4879 /* WINS will be nonzero when the switch is done
4880 if all operands are constant. */
4883 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4884 Likewise for a SAVE_EXPR that's already been evaluated. */
4885 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0))
4888 /* Return right away if a constant. */
4892 #ifdef MAX_INTEGER_COMPUTATION_MODE
4893 check_max_integer_computation_mode (expr);
4896 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4900 /* Special case for conversion ops that can have fixed point args. */
4901 arg0 = TREE_OPERAND (t, 0);
4903 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4905 STRIP_SIGN_NOPS (arg0);
4907 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4908 subop = TREE_REALPART (arg0);
4912 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4913 && TREE_CODE (subop) != REAL_CST
4915 /* Note that TREE_CONSTANT isn't enough:
4916 static var addresses are constant but we can't
4917 do arithmetic on them. */
4920 else if (IS_EXPR_CODE_CLASS (kind) || kind == 'r')
4922 int len = first_rtl_op (code);
4924 for (i = 0; i < len; i++)
4926 tree op = TREE_OPERAND (t, i);
4930 continue; /* Valid for CALL_EXPR, at least. */
4932 if (kind == '<' || code == RSHIFT_EXPR)
4934 /* Signedness matters here. Perhaps we can refine this
4936 STRIP_SIGN_NOPS (op);
4939 /* Strip any conversions that don't change the mode. */
4942 if (TREE_CODE (op) == COMPLEX_CST)
4943 subop = TREE_REALPART (op);
4947 if (TREE_CODE (subop) != INTEGER_CST
4948 && TREE_CODE (subop) != REAL_CST)
4949 /* Note that TREE_CONSTANT isn't enough:
4950 static var addresses are constant but we can't
4951 do arithmetic on them. */
4961 /* If this is a commutative operation, and ARG0 is a constant, move it
4962 to ARG1 to reduce the number of tests below. */
4963 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
4964 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
4965 || code == BIT_AND_EXPR)
4966 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
4968 tem = arg0; arg0 = arg1; arg1 = tem;
4970 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
4971 TREE_OPERAND (t, 1) = tem;
4974 /* Now WINS is set as described above,
4975 ARG0 is the first operand of EXPR,
4976 and ARG1 is the second operand (if it has more than one operand).
4978 First check for cases where an arithmetic operation is applied to a
4979 compound, conditional, or comparison operation. Push the arithmetic
4980 operation inside the compound or conditional to see if any folding
4981 can then be done. Convert comparison to conditional for this purpose.
4982 The also optimizes non-constant cases that used to be done in
4985 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
4986 one of the operands is a comparison and the other is a comparison, a
4987 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
4988 code below would make the expression more complex. Change it to a
4989 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
4990 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
4992 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
4993 || code == EQ_EXPR || code == NE_EXPR)
4994 && ((truth_value_p (TREE_CODE (arg0))
4995 && (truth_value_p (TREE_CODE (arg1))
4996 || (TREE_CODE (arg1) == BIT_AND_EXPR
4997 && integer_onep (TREE_OPERAND (arg1, 1)))))
4998 || (truth_value_p (TREE_CODE (arg1))
4999 && (truth_value_p (TREE_CODE (arg0))
5000 || (TREE_CODE (arg0) == BIT_AND_EXPR
5001 && integer_onep (TREE_OPERAND (arg0, 1)))))))
5003 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
5004 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
5008 if (code == EQ_EXPR)
5009 t = invert_truthvalue (t);
5014 if (TREE_CODE_CLASS (code) == '1')
5016 if (TREE_CODE (arg0) == COMPOUND_EXPR)
5017 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5018 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
5019 else if (TREE_CODE (arg0) == COND_EXPR)
5021 tree arg01 = TREE_OPERAND (arg0, 1);
5022 tree arg02 = TREE_OPERAND (arg0, 2);
5023 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
5024 arg01 = fold (build1 (code, type, arg01));
5025 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
5026 arg02 = fold (build1 (code, type, arg02));
5027 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
5030 /* If this was a conversion, and all we did was to move into
5031 inside the COND_EXPR, bring it back out. But leave it if
5032 it is a conversion from integer to integer and the
5033 result precision is no wider than a word since such a
5034 conversion is cheap and may be optimized away by combine,
5035 while it couldn't if it were outside the COND_EXPR. Then return
5036 so we don't get into an infinite recursion loop taking the
5037 conversion out and then back in. */
5039 if ((code == NOP_EXPR || code == CONVERT_EXPR
5040 || code == NON_LVALUE_EXPR)
5041 && TREE_CODE (t) == COND_EXPR
5042 && TREE_CODE (TREE_OPERAND (t, 1)) == code
5043 && TREE_CODE (TREE_OPERAND (t, 2)) == code
5044 && ! VOID_TYPE_P (TREE_OPERAND (t, 1))
5045 && ! VOID_TYPE_P (TREE_OPERAND (t, 2))
5046 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
5047 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
5048 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
5050 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
5051 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
5052 t = build1 (code, type,
5054 TREE_TYPE (TREE_OPERAND
5055 (TREE_OPERAND (t, 1), 0)),
5056 TREE_OPERAND (t, 0),
5057 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
5058 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
5061 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
5062 return fold (build (COND_EXPR, type, arg0,
5063 fold (build1 (code, type, integer_one_node)),
5064 fold (build1 (code, type, integer_zero_node))));
5066 else if (TREE_CODE_CLASS (code) == '<'
5067 && TREE_CODE (arg0) == COMPOUND_EXPR)
5068 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5069 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5070 else if (TREE_CODE_CLASS (code) == '<'
5071 && TREE_CODE (arg1) == COMPOUND_EXPR)
5072 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5073 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
5074 else if (TREE_CODE_CLASS (code) == '2'
5075 || TREE_CODE_CLASS (code) == '<')
5077 if (TREE_CODE (arg1) == COMPOUND_EXPR
5078 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1, 0))
5079 && ! TREE_SIDE_EFFECTS (arg0))
5080 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5081 fold (build (code, type,
5082 arg0, TREE_OPERAND (arg1, 1))));
5083 else if ((TREE_CODE (arg1) == COND_EXPR
5084 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
5085 && TREE_CODE_CLASS (code) != '<'))
5086 && (TREE_CODE (arg0) != COND_EXPR
5087 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5088 && (! TREE_SIDE_EFFECTS (arg0)
5089 || ((*lang_hooks.decls.global_bindings_p) () == 0
5090 && ! contains_placeholder_p (arg0))))
5092 fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
5093 /*cond_first_p=*/0);
5094 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
5095 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5096 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5097 else if ((TREE_CODE (arg0) == COND_EXPR
5098 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
5099 && TREE_CODE_CLASS (code) != '<'))
5100 && (TREE_CODE (arg1) != COND_EXPR
5101 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5102 && (! TREE_SIDE_EFFECTS (arg1)
5103 || ((*lang_hooks.decls.global_bindings_p) () == 0
5104 && ! contains_placeholder_p (arg1))))
5106 fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
5107 /*cond_first_p=*/1);
5121 return fold (DECL_INITIAL (t));
5126 case FIX_TRUNC_EXPR:
5127 /* Other kinds of FIX are not handled properly by fold_convert. */
5129 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
5130 return TREE_OPERAND (t, 0);
5132 /* Handle cases of two conversions in a row. */
5133 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
5134 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
5136 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5137 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
5138 tree final_type = TREE_TYPE (t);
5139 int inside_int = INTEGRAL_TYPE_P (inside_type);
5140 int inside_ptr = POINTER_TYPE_P (inside_type);
5141 int inside_float = FLOAT_TYPE_P (inside_type);
5142 unsigned int inside_prec = TYPE_PRECISION (inside_type);
5143 int inside_unsignedp = TREE_UNSIGNED (inside_type);
5144 int inter_int = INTEGRAL_TYPE_P (inter_type);
5145 int inter_ptr = POINTER_TYPE_P (inter_type);
5146 int inter_float = FLOAT_TYPE_P (inter_type);
5147 unsigned int inter_prec = TYPE_PRECISION (inter_type);
5148 int inter_unsignedp = TREE_UNSIGNED (inter_type);
5149 int final_int = INTEGRAL_TYPE_P (final_type);
5150 int final_ptr = POINTER_TYPE_P (final_type);
5151 int final_float = FLOAT_TYPE_P (final_type);
5152 unsigned int final_prec = TYPE_PRECISION (final_type);
5153 int final_unsignedp = TREE_UNSIGNED (final_type);
5155 /* In addition to the cases of two conversions in a row
5156 handled below, if we are converting something to its own
5157 type via an object of identical or wider precision, neither
5158 conversion is needed. */
5159 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (final_type)
5160 && ((inter_int && final_int) || (inter_float && final_float))
5161 && inter_prec >= final_prec)
5162 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5164 /* Likewise, if the intermediate and final types are either both
5165 float or both integer, we don't need the middle conversion if
5166 it is wider than the final type and doesn't change the signedness
5167 (for integers). Avoid this if the final type is a pointer
5168 since then we sometimes need the inner conversion. Likewise if
5169 the outer has a precision not equal to the size of its mode. */
5170 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
5171 || (inter_float && inside_float))
5172 && inter_prec >= inside_prec
5173 && (inter_float || inter_unsignedp == inside_unsignedp)
5174 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5175 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5177 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5179 /* If we have a sign-extension of a zero-extended value, we can
5180 replace that by a single zero-extension. */
5181 if (inside_int && inter_int && final_int
5182 && inside_prec < inter_prec && inter_prec < final_prec
5183 && inside_unsignedp && !inter_unsignedp)
5184 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5186 /* Two conversions in a row are not needed unless:
5187 - some conversion is floating-point (overstrict for now), or
5188 - the intermediate type is narrower than both initial and
5190 - the intermediate type and innermost type differ in signedness,
5191 and the outermost type is wider than the intermediate, or
5192 - the initial type is a pointer type and the precisions of the
5193 intermediate and final types differ, or
5194 - the final type is a pointer type and the precisions of the
5195 initial and intermediate types differ. */
5196 if (! inside_float && ! inter_float && ! final_float
5197 && (inter_prec > inside_prec || inter_prec > final_prec)
5198 && ! (inside_int && inter_int
5199 && inter_unsignedp != inside_unsignedp
5200 && inter_prec < final_prec)
5201 && ((inter_unsignedp && inter_prec > inside_prec)
5202 == (final_unsignedp && final_prec > inter_prec))
5203 && ! (inside_ptr && inter_prec != final_prec)
5204 && ! (final_ptr && inside_prec != inter_prec)
5205 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5206 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5208 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5211 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5212 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5213 /* Detect assigning a bitfield. */
5214 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5215 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5217 /* Don't leave an assignment inside a conversion
5218 unless assigning a bitfield. */
5219 tree prev = TREE_OPERAND (t, 0);
5220 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5221 /* First do the assignment, then return converted constant. */
5222 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5227 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
5228 constants (if x has signed type, the sign bit cannot be set
5229 in c). This folds extension into the BIT_AND_EXPR. */
5230 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
5231 && TREE_CODE (TREE_TYPE (t)) != BOOLEAN_TYPE
5232 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
5233 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
5235 tree and = TREE_OPERAND (t, 0);
5236 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
5239 if (TREE_UNSIGNED (TREE_TYPE (and))
5240 || (TYPE_PRECISION (TREE_TYPE (t))
5241 <= TYPE_PRECISION (TREE_TYPE (and))))
5243 else if (TYPE_PRECISION (TREE_TYPE (and1))
5244 <= HOST_BITS_PER_WIDE_INT
5245 && host_integerp (and1, 1))
5247 unsigned HOST_WIDE_INT cst;
5249 cst = tree_low_cst (and1, 1);
5250 cst &= (HOST_WIDE_INT) -1
5251 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
5252 change = (cst == 0);
5253 #ifdef LOAD_EXTEND_OP
5255 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
5258 tree uns = (*lang_hooks.types.unsigned_type) (TREE_TYPE (and0));
5259 and0 = convert (uns, and0);
5260 and1 = convert (uns, and1);
5265 return fold (build (BIT_AND_EXPR, TREE_TYPE (t),
5266 convert (TREE_TYPE (t), and0),
5267 convert (TREE_TYPE (t), and1)));
5272 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
5275 return fold_convert (t, arg0);
5277 case VIEW_CONVERT_EXPR:
5278 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
5279 return build1 (VIEW_CONVERT_EXPR, type,
5280 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5284 if (TREE_CODE (arg0) == CONSTRUCTOR)
5286 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5293 TREE_CONSTANT (t) = wins;
5299 if (TREE_CODE (arg0) == INTEGER_CST)
5301 unsigned HOST_WIDE_INT low;
5303 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5304 TREE_INT_CST_HIGH (arg0),
5306 t = build_int_2 (low, high);
5307 TREE_TYPE (t) = type;
5309 = (TREE_OVERFLOW (arg0)
5310 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
5311 TREE_CONSTANT_OVERFLOW (t)
5312 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5314 else if (TREE_CODE (arg0) == REAL_CST)
5315 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5317 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5318 return TREE_OPERAND (arg0, 0);
5319 /* Convert -((double)float) into (double)(-float). */
5320 else if (TREE_CODE (arg0) == NOP_EXPR
5321 && TREE_CODE (type) == REAL_TYPE)
5323 tree targ0 = strip_float_extensions (arg0);
5325 return convert (type, build1 (NEGATE_EXPR, TREE_TYPE (targ0), targ0));
5329 /* Convert - (a - b) to (b - a) for non-floating-point. */
5330 else if (TREE_CODE (arg0) == MINUS_EXPR
5331 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
5332 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
5333 TREE_OPERAND (arg0, 0));
5340 if (TREE_CODE (arg0) == INTEGER_CST)
5342 /* If the value is unsigned, then the absolute value is
5343 the same as the ordinary value. */
5344 if (TREE_UNSIGNED (type))
5346 /* Similarly, if the value is non-negative. */
5347 else if (INT_CST_LT (integer_minus_one_node, arg0))
5349 /* If the value is negative, then the absolute value is
5353 unsigned HOST_WIDE_INT low;
5355 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5356 TREE_INT_CST_HIGH (arg0),
5358 t = build_int_2 (low, high);
5359 TREE_TYPE (t) = type;
5361 = (TREE_OVERFLOW (arg0)
5362 | force_fit_type (t, overflow));
5363 TREE_CONSTANT_OVERFLOW (t)
5364 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5367 else if (TREE_CODE (arg0) == REAL_CST)
5369 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5370 t = build_real (type,
5371 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5374 else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR)
5375 return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
5376 /* Convert fabs((double)float) into (double)fabsf(float). */
5377 else if (TREE_CODE (arg0) == NOP_EXPR
5378 && TREE_CODE (type) == REAL_TYPE)
5380 tree targ0 = strip_float_extensions (arg0);
5382 return convert (type, build1 (ABS_EXPR, TREE_TYPE (targ0), targ0));
5387 /* fabs(sqrt(x)) = sqrt(x) and fabs(exp(x)) = exp(x). */
5388 enum built_in_function fcode = builtin_mathfn_code (arg0);
5389 if (fcode == BUILT_IN_SQRT
5390 || fcode == BUILT_IN_SQRTF
5391 || fcode == BUILT_IN_SQRTL
5392 || fcode == BUILT_IN_EXP
5393 || fcode == BUILT_IN_EXPF
5394 || fcode == BUILT_IN_EXPL)
5400 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5401 return convert (type, arg0);
5402 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5403 return build (COMPLEX_EXPR, type,
5404 TREE_OPERAND (arg0, 0),
5405 negate_expr (TREE_OPERAND (arg0, 1)));
5406 else if (TREE_CODE (arg0) == COMPLEX_CST)
5407 return build_complex (type, TREE_REALPART (arg0),
5408 negate_expr (TREE_IMAGPART (arg0)));
5409 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5410 return fold (build (TREE_CODE (arg0), type,
5411 fold (build1 (CONJ_EXPR, type,
5412 TREE_OPERAND (arg0, 0))),
5413 fold (build1 (CONJ_EXPR,
5414 type, TREE_OPERAND (arg0, 1)))));
5415 else if (TREE_CODE (arg0) == CONJ_EXPR)
5416 return TREE_OPERAND (arg0, 0);
5422 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5423 ~ TREE_INT_CST_HIGH (arg0));
5424 TREE_TYPE (t) = type;
5425 force_fit_type (t, 0);
5426 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5427 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5429 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5430 return TREE_OPERAND (arg0, 0);
5434 /* A + (-B) -> A - B */
5435 if (TREE_CODE (arg1) == NEGATE_EXPR)
5436 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5437 /* (-A) + B -> B - A */
5438 if (TREE_CODE (arg0) == NEGATE_EXPR)
5439 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5440 else if (! FLOAT_TYPE_P (type))
5442 if (integer_zerop (arg1))
5443 return non_lvalue (convert (type, arg0));
5445 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5446 with a constant, and the two constants have no bits in common,
5447 we should treat this as a BIT_IOR_EXPR since this may produce more
5449 if (TREE_CODE (arg0) == BIT_AND_EXPR
5450 && TREE_CODE (arg1) == BIT_AND_EXPR
5451 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5452 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5453 && integer_zerop (const_binop (BIT_AND_EXPR,
5454 TREE_OPERAND (arg0, 1),
5455 TREE_OPERAND (arg1, 1), 0)))
5457 code = BIT_IOR_EXPR;
5461 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5462 (plus (plus (mult) (mult)) (foo)) so that we can
5463 take advantage of the factoring cases below. */
5464 if ((TREE_CODE (arg0) == PLUS_EXPR
5465 && TREE_CODE (arg1) == MULT_EXPR)
5466 || (TREE_CODE (arg1) == PLUS_EXPR
5467 && TREE_CODE (arg0) == MULT_EXPR))
5469 tree parg0, parg1, parg, marg;
5471 if (TREE_CODE (arg0) == PLUS_EXPR)
5472 parg = arg0, marg = arg1;
5474 parg = arg1, marg = arg0;
5475 parg0 = TREE_OPERAND (parg, 0);
5476 parg1 = TREE_OPERAND (parg, 1);
5480 if (TREE_CODE (parg0) == MULT_EXPR
5481 && TREE_CODE (parg1) != MULT_EXPR)
5482 return fold (build (PLUS_EXPR, type,
5483 fold (build (PLUS_EXPR, type, parg0, marg)),
5485 if (TREE_CODE (parg0) != MULT_EXPR
5486 && TREE_CODE (parg1) == MULT_EXPR)
5487 return fold (build (PLUS_EXPR, type,
5488 fold (build (PLUS_EXPR, type, parg1, marg)),
5492 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5494 tree arg00, arg01, arg10, arg11;
5495 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5497 /* (A * C) + (B * C) -> (A+B) * C.
5498 We are most concerned about the case where C is a constant,
5499 but other combinations show up during loop reduction. Since
5500 it is not difficult, try all four possibilities. */
5502 arg00 = TREE_OPERAND (arg0, 0);
5503 arg01 = TREE_OPERAND (arg0, 1);
5504 arg10 = TREE_OPERAND (arg1, 0);
5505 arg11 = TREE_OPERAND (arg1, 1);
5508 if (operand_equal_p (arg01, arg11, 0))
5509 same = arg01, alt0 = arg00, alt1 = arg10;
5510 else if (operand_equal_p (arg00, arg10, 0))
5511 same = arg00, alt0 = arg01, alt1 = arg11;
5512 else if (operand_equal_p (arg00, arg11, 0))
5513 same = arg00, alt0 = arg01, alt1 = arg10;
5514 else if (operand_equal_p (arg01, arg10, 0))
5515 same = arg01, alt0 = arg00, alt1 = arg11;
5517 /* No identical multiplicands; see if we can find a common
5518 power-of-two factor in non-power-of-two multiplies. This
5519 can help in multi-dimensional array access. */
5520 else if (TREE_CODE (arg01) == INTEGER_CST
5521 && TREE_CODE (arg11) == INTEGER_CST
5522 && TREE_INT_CST_HIGH (arg01) == 0
5523 && TREE_INT_CST_HIGH (arg11) == 0)
5525 HOST_WIDE_INT int01, int11, tmp;
5526 int01 = TREE_INT_CST_LOW (arg01);
5527 int11 = TREE_INT_CST_LOW (arg11);
5529 /* Move min of absolute values to int11. */
5530 if ((int01 >= 0 ? int01 : -int01)
5531 < (int11 >= 0 ? int11 : -int11))
5533 tmp = int01, int01 = int11, int11 = tmp;
5534 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5535 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5538 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5540 alt0 = fold (build (MULT_EXPR, type, arg00,
5541 build_int_2 (int01 / int11, 0)));
5548 return fold (build (MULT_EXPR, type,
5549 fold (build (PLUS_EXPR, type, alt0, alt1)),
5554 /* See if ARG1 is zero and X + ARG1 reduces to X. */
5555 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
5556 return non_lvalue (convert (type, arg0));
5558 /* Likewise if the operands are reversed. */
5559 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
5560 return non_lvalue (convert (type, arg1));
5563 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5564 is a rotate of A by C1 bits. */
5565 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5566 is a rotate of A by B bits. */
5568 enum tree_code code0, code1;
5569 code0 = TREE_CODE (arg0);
5570 code1 = TREE_CODE (arg1);
5571 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5572 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5573 && operand_equal_p (TREE_OPERAND (arg0, 0),
5574 TREE_OPERAND (arg1, 0), 0)
5575 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5577 tree tree01, tree11;
5578 enum tree_code code01, code11;
5580 tree01 = TREE_OPERAND (arg0, 1);
5581 tree11 = TREE_OPERAND (arg1, 1);
5582 STRIP_NOPS (tree01);
5583 STRIP_NOPS (tree11);
5584 code01 = TREE_CODE (tree01);
5585 code11 = TREE_CODE (tree11);
5586 if (code01 == INTEGER_CST
5587 && code11 == INTEGER_CST
5588 && TREE_INT_CST_HIGH (tree01) == 0
5589 && TREE_INT_CST_HIGH (tree11) == 0
5590 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5591 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5592 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5593 code0 == LSHIFT_EXPR ? tree01 : tree11);
5594 else if (code11 == MINUS_EXPR)
5596 tree tree110, tree111;
5597 tree110 = TREE_OPERAND (tree11, 0);
5598 tree111 = TREE_OPERAND (tree11, 1);
5599 STRIP_NOPS (tree110);
5600 STRIP_NOPS (tree111);
5601 if (TREE_CODE (tree110) == INTEGER_CST
5602 && 0 == compare_tree_int (tree110,
5604 (TREE_TYPE (TREE_OPERAND
5606 && operand_equal_p (tree01, tree111, 0))
5607 return build ((code0 == LSHIFT_EXPR
5610 type, TREE_OPERAND (arg0, 0), tree01);
5612 else if (code01 == MINUS_EXPR)
5614 tree tree010, tree011;
5615 tree010 = TREE_OPERAND (tree01, 0);
5616 tree011 = TREE_OPERAND (tree01, 1);
5617 STRIP_NOPS (tree010);
5618 STRIP_NOPS (tree011);
5619 if (TREE_CODE (tree010) == INTEGER_CST
5620 && 0 == compare_tree_int (tree010,
5622 (TREE_TYPE (TREE_OPERAND
5624 && operand_equal_p (tree11, tree011, 0))
5625 return build ((code0 != LSHIFT_EXPR
5628 type, TREE_OPERAND (arg0, 0), tree11);
5634 /* In most languages, can't associate operations on floats through
5635 parentheses. Rather than remember where the parentheses were, we
5636 don't associate floats at all. It shouldn't matter much. However,
5637 associating multiplications is only very slightly inaccurate, so do
5638 that if -funsafe-math-optimizations is specified. */
5641 && (! FLOAT_TYPE_P (type)
5642 || (flag_unsafe_math_optimizations && code == MULT_EXPR)))
5644 tree var0, con0, lit0, minus_lit0;
5645 tree var1, con1, lit1, minus_lit1;
5647 /* Split both trees into variables, constants, and literals. Then
5648 associate each group together, the constants with literals,
5649 then the result with variables. This increases the chances of
5650 literals being recombined later and of generating relocatable
5651 expressions for the sum of a constant and literal. */
5652 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
5653 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
5654 code == MINUS_EXPR);
5656 /* Only do something if we found more than two objects. Otherwise,
5657 nothing has changed and we risk infinite recursion. */
5658 if (2 < ((var0 != 0) + (var1 != 0)
5659 + (con0 != 0) + (con1 != 0)
5660 + (lit0 != 0) + (lit1 != 0)
5661 + (minus_lit0 != 0) + (minus_lit1 != 0)))
5663 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
5664 if (code == MINUS_EXPR)
5667 var0 = associate_trees (var0, var1, code, type);
5668 con0 = associate_trees (con0, con1, code, type);
5669 lit0 = associate_trees (lit0, lit1, code, type);
5670 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
5672 /* Preserve the MINUS_EXPR if the negative part of the literal is
5673 greater than the positive part. Otherwise, the multiplicative
5674 folding code (i.e extract_muldiv) may be fooled in case
5675 unsigned constants are substracted, like in the following
5676 example: ((X*2 + 4) - 8U)/2. */
5677 if (minus_lit0 && lit0)
5679 if (tree_int_cst_lt (lit0, minus_lit0))
5681 minus_lit0 = associate_trees (minus_lit0, lit0,
5687 lit0 = associate_trees (lit0, minus_lit0,
5695 return convert (type, associate_trees (var0, minus_lit0,
5699 con0 = associate_trees (con0, minus_lit0,
5701 return convert (type, associate_trees (var0, con0,
5706 con0 = associate_trees (con0, lit0, code, type);
5707 return convert (type, associate_trees (var0, con0, code, type));
5713 t1 = const_binop (code, arg0, arg1, 0);
5714 if (t1 != NULL_TREE)
5716 /* The return value should always have
5717 the same type as the original expression. */
5718 if (TREE_TYPE (t1) != TREE_TYPE (t))
5719 t1 = convert (TREE_TYPE (t), t1);
5726 /* A - (-B) -> A + B */
5727 if (TREE_CODE (arg1) == NEGATE_EXPR)
5728 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5729 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
5730 if (TREE_CODE (arg0) == NEGATE_EXPR
5731 && FLOAT_TYPE_P (type)
5732 && negate_expr_p (arg1)
5733 && (! TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
5734 && (! TREE_SIDE_EFFECTS (arg1) || TREE_CONSTANT (arg0)))
5735 return fold (build (MINUS_EXPR, type, negate_expr (arg1),
5736 TREE_OPERAND (arg0, 0)));
5738 if (! FLOAT_TYPE_P (type))
5740 if (! wins && integer_zerop (arg0))
5741 return negate_expr (convert (type, arg1));
5742 if (integer_zerop (arg1))
5743 return non_lvalue (convert (type, arg0));
5745 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5746 about the case where C is a constant, just try one of the
5747 four possibilities. */
5749 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5750 && operand_equal_p (TREE_OPERAND (arg0, 1),
5751 TREE_OPERAND (arg1, 1), 0))
5752 return fold (build (MULT_EXPR, type,
5753 fold (build (MINUS_EXPR, type,
5754 TREE_OPERAND (arg0, 0),
5755 TREE_OPERAND (arg1, 0))),
5756 TREE_OPERAND (arg0, 1)));
5758 /* Fold A - (A & B) into ~B & A. */
5759 if (!TREE_SIDE_EFFECTS (arg0)
5760 && TREE_CODE (arg1) == BIT_AND_EXPR)
5762 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
5763 return fold (build (BIT_AND_EXPR, type,
5764 fold (build1 (BIT_NOT_EXPR, type,
5765 TREE_OPERAND (arg1, 0))),
5767 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
5768 return fold (build (BIT_AND_EXPR, type,
5769 fold (build1 (BIT_NOT_EXPR, type,
5770 TREE_OPERAND (arg1, 1))),
5775 /* See if ARG1 is zero and X - ARG1 reduces to X. */
5776 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
5777 return non_lvalue (convert (type, arg0));
5779 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
5780 ARG0 is zero and X + ARG0 reduces to X, since that would mean
5781 (-ARG1 + ARG0) reduces to -ARG1. */
5782 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
5783 return negate_expr (convert (type, arg1));
5785 /* Fold &x - &x. This can happen from &x.foo - &x.
5786 This is unsafe for certain floats even in non-IEEE formats.
5787 In IEEE, it is unsafe because it does wrong for NaNs.
5788 Also note that operand_equal_p is always false if an operand
5791 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
5792 && operand_equal_p (arg0, arg1, 0))
5793 return convert (type, integer_zero_node);
5798 /* (-A) * (-B) -> A * B */
5799 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5800 return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
5801 TREE_OPERAND (arg1, 0)));
5803 if (! FLOAT_TYPE_P (type))
5805 if (integer_zerop (arg1))
5806 return omit_one_operand (type, arg1, arg0);
5807 if (integer_onep (arg1))
5808 return non_lvalue (convert (type, arg0));
5810 /* (a * (1 << b)) is (a << b) */
5811 if (TREE_CODE (arg1) == LSHIFT_EXPR
5812 && integer_onep (TREE_OPERAND (arg1, 0)))
5813 return fold (build (LSHIFT_EXPR, type, arg0,
5814 TREE_OPERAND (arg1, 1)));
5815 if (TREE_CODE (arg0) == LSHIFT_EXPR
5816 && integer_onep (TREE_OPERAND (arg0, 0)))
5817 return fold (build (LSHIFT_EXPR, type, arg1,
5818 TREE_OPERAND (arg0, 1)));
5820 if (TREE_CODE (arg1) == INTEGER_CST
5821 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5823 return convert (type, tem);
5828 /* Maybe fold x * 0 to 0. The expressions aren't the same
5829 when x is NaN, since x * 0 is also NaN. Nor are they the
5830 same in modes with signed zeros, since multiplying a
5831 negative value by 0 gives -0, not +0. */
5832 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
5833 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
5834 && real_zerop (arg1))
5835 return omit_one_operand (type, arg1, arg0);
5836 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
5837 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
5838 && real_onep (arg1))
5839 return non_lvalue (convert (type, arg0));
5841 /* Transform x * -1.0 into -x. */
5842 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
5843 && real_minus_onep (arg1))
5844 return fold (build1 (NEGATE_EXPR, type, arg0));
5847 if (! wins && real_twop (arg1)
5848 && (*lang_hooks.decls.global_bindings_p) () == 0
5849 && ! contains_placeholder_p (arg0))
5851 tree arg = save_expr (arg0);
5852 return fold (build (PLUS_EXPR, type, arg, arg));
5855 if (flag_unsafe_math_optimizations)
5857 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
5858 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
5860 /* Optimizations of sqrt(...)*sqrt(...). */
5861 if ((fcode0 == BUILT_IN_SQRT && fcode1 == BUILT_IN_SQRT)
5862 || (fcode0 == BUILT_IN_SQRTF && fcode1 == BUILT_IN_SQRTF)
5863 || (fcode0 == BUILT_IN_SQRTL && fcode1 == BUILT_IN_SQRTL))
5865 tree sqrtfn, arg, arglist;
5866 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
5867 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
5869 /* Optimize sqrt(x)*sqrt(x) as x. */
5870 if (operand_equal_p (arg00, arg10, 0)
5871 && ! HONOR_SNANS (TYPE_MODE (type)))
5874 /* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */
5875 sqrtfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5876 arg = fold (build (MULT_EXPR, type, arg00, arg10));
5877 arglist = build_tree_list (NULL_TREE, arg);
5878 return build_function_call_expr (sqrtfn, arglist);
5881 /* Optimize exp(x)*exp(y) as exp(x+y). */
5882 if ((fcode0 == BUILT_IN_EXP && fcode1 == BUILT_IN_EXP)
5883 || (fcode0 == BUILT_IN_EXPF && fcode1 == BUILT_IN_EXPF)
5884 || (fcode0 == BUILT_IN_EXPL && fcode1 == BUILT_IN_EXPL))
5886 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5887 tree arg = build (PLUS_EXPR, type,
5888 TREE_VALUE (TREE_OPERAND (arg0, 1)),
5889 TREE_VALUE (TREE_OPERAND (arg1, 1)));
5890 tree arglist = build_tree_list (NULL_TREE, fold (arg));
5891 return build_function_call_expr (expfn, arglist);
5894 /* Optimizations of pow(...)*pow(...). */
5895 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
5896 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
5897 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
5899 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
5900 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
5902 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
5903 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
5906 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
5907 if (operand_equal_p (arg01, arg11, 0))
5909 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5910 tree arg = build (MULT_EXPR, type, arg00, arg10);
5911 tree arglist = tree_cons (NULL_TREE, fold (arg),
5912 build_tree_list (NULL_TREE,
5914 return build_function_call_expr (powfn, arglist);
5917 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
5918 if (operand_equal_p (arg00, arg10, 0))
5920 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5921 tree arg = fold (build (PLUS_EXPR, type, arg01, arg11));
5922 tree arglist = tree_cons (NULL_TREE, arg00,
5923 build_tree_list (NULL_TREE,
5925 return build_function_call_expr (powfn, arglist);
5934 if (integer_all_onesp (arg1))
5935 return omit_one_operand (type, arg1, arg0);
5936 if (integer_zerop (arg1))
5937 return non_lvalue (convert (type, arg0));
5938 t1 = distribute_bit_expr (code, type, arg0, arg1);
5939 if (t1 != NULL_TREE)
5942 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
5944 This results in more efficient code for machines without a NAND
5945 instruction. Combine will canonicalize to the first form
5946 which will allow use of NAND instructions provided by the
5947 backend if they exist. */
5948 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5949 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5951 return fold (build1 (BIT_NOT_EXPR, type,
5952 build (BIT_AND_EXPR, type,
5953 TREE_OPERAND (arg0, 0),
5954 TREE_OPERAND (arg1, 0))));
5957 /* See if this can be simplified into a rotate first. If that
5958 is unsuccessful continue in the association code. */
5962 if (integer_zerop (arg1))
5963 return non_lvalue (convert (type, arg0));
5964 if (integer_all_onesp (arg1))
5965 return fold (build1 (BIT_NOT_EXPR, type, arg0));
5967 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
5968 with a constant, and the two constants have no bits in common,
5969 we should treat this as a BIT_IOR_EXPR since this may produce more
5971 if (TREE_CODE (arg0) == BIT_AND_EXPR
5972 && TREE_CODE (arg1) == BIT_AND_EXPR
5973 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5974 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5975 && integer_zerop (const_binop (BIT_AND_EXPR,
5976 TREE_OPERAND (arg0, 1),
5977 TREE_OPERAND (arg1, 1), 0)))
5979 code = BIT_IOR_EXPR;
5983 /* See if this can be simplified into a rotate first. If that
5984 is unsuccessful continue in the association code. */
5989 if (integer_all_onesp (arg1))
5990 return non_lvalue (convert (type, arg0));
5991 if (integer_zerop (arg1))
5992 return omit_one_operand (type, arg1, arg0);
5993 t1 = distribute_bit_expr (code, type, arg0, arg1);
5994 if (t1 != NULL_TREE)
5996 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5997 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
5998 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6001 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
6003 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
6004 && (~TREE_INT_CST_LOW (arg1)
6005 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
6006 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
6009 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
6011 This results in more efficient code for machines without a NOR
6012 instruction. Combine will canonicalize to the first form
6013 which will allow use of NOR instructions provided by the
6014 backend if they exist. */
6015 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6016 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6018 return fold (build1 (BIT_NOT_EXPR, type,
6019 build (BIT_IOR_EXPR, type,
6020 TREE_OPERAND (arg0, 0),
6021 TREE_OPERAND (arg1, 0))));
6026 case BIT_ANDTC_EXPR:
6027 if (integer_all_onesp (arg0))
6028 return non_lvalue (convert (type, arg1));
6029 if (integer_zerop (arg0))
6030 return omit_one_operand (type, arg0, arg1);
6031 if (TREE_CODE (arg1) == INTEGER_CST)
6033 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
6034 code = BIT_AND_EXPR;
6040 /* Don't touch a floating-point divide by zero unless the mode
6041 of the constant can represent infinity. */
6042 if (TREE_CODE (arg1) == REAL_CST
6043 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
6044 && real_zerop (arg1))
6047 /* (-A) / (-B) -> A / B */
6048 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
6049 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
6050 TREE_OPERAND (arg1, 0)));
6052 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
6053 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6054 && real_onep (arg1))
6055 return non_lvalue (convert (type, arg0));
6057 /* If ARG1 is a constant, we can convert this to a multiply by the
6058 reciprocal. This does not have the same rounding properties,
6059 so only do this if -funsafe-math-optimizations. We can actually
6060 always safely do it if ARG1 is a power of two, but it's hard to
6061 tell if it is or not in a portable manner. */
6062 if (TREE_CODE (arg1) == REAL_CST)
6064 if (flag_unsafe_math_optimizations
6065 && 0 != (tem = const_binop (code, build_real (type, dconst1),
6067 return fold (build (MULT_EXPR, type, arg0, tem));
6068 /* Find the reciprocal if optimizing and the result is exact. */
6072 r = TREE_REAL_CST (arg1);
6073 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
6075 tem = build_real (type, r);
6076 return fold (build (MULT_EXPR, type, arg0, tem));
6080 /* Convert A/B/C to A/(B*C). */
6081 if (flag_unsafe_math_optimizations
6082 && TREE_CODE (arg0) == RDIV_EXPR)
6084 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
6085 build (MULT_EXPR, type, TREE_OPERAND (arg0, 1),
6088 /* Convert A/(B/C) to (A/B)*C. */
6089 if (flag_unsafe_math_optimizations
6090 && TREE_CODE (arg1) == RDIV_EXPR)
6092 return fold (build (MULT_EXPR, type,
6093 build (RDIV_EXPR, type, arg0,
6094 TREE_OPERAND (arg1, 0)),
6095 TREE_OPERAND (arg1, 1)));
6098 if (flag_unsafe_math_optimizations)
6100 enum built_in_function fcode = builtin_mathfn_code (arg1);
6101 /* Optimize x/exp(y) into x*exp(-y). */
6102 if (fcode == BUILT_IN_EXP
6103 || fcode == BUILT_IN_EXPF
6104 || fcode == BUILT_IN_EXPL)
6106 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6107 tree arg = build1 (NEGATE_EXPR, type,
6108 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6109 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6110 arg1 = build_function_call_expr (expfn, arglist);
6111 return fold (build (MULT_EXPR, type, arg0, arg1));
6114 /* Optimize x/pow(y,z) into x*pow(y,-z). */
6115 if (fcode == BUILT_IN_POW
6116 || fcode == BUILT_IN_POWF
6117 || fcode == BUILT_IN_POWL)
6119 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6120 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6121 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
6122 tree neg11 = fold (build1 (NEGATE_EXPR, type, arg11));
6123 tree arglist = tree_cons(NULL_TREE, arg10,
6124 build_tree_list (NULL_TREE, neg11));
6125 arg1 = build_function_call_expr (powfn, arglist);
6126 return fold (build (MULT_EXPR, type, arg0, arg1));
6131 case TRUNC_DIV_EXPR:
6132 case ROUND_DIV_EXPR:
6133 case FLOOR_DIV_EXPR:
6135 case EXACT_DIV_EXPR:
6136 if (integer_onep (arg1))
6137 return non_lvalue (convert (type, arg0));
6138 if (integer_zerop (arg1))
6141 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
6142 operation, EXACT_DIV_EXPR.
6144 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
6145 At one time others generated faster code, it's not clear if they do
6146 after the last round to changes to the DIV code in expmed.c. */
6147 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
6148 && multiple_of_p (type, arg0, arg1))
6149 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
6151 if (TREE_CODE (arg1) == INTEGER_CST
6152 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6154 return convert (type, tem);
6159 case FLOOR_MOD_EXPR:
6160 case ROUND_MOD_EXPR:
6161 case TRUNC_MOD_EXPR:
6162 if (integer_onep (arg1))
6163 return omit_one_operand (type, integer_zero_node, arg0);
6164 if (integer_zerop (arg1))
6167 if (TREE_CODE (arg1) == INTEGER_CST
6168 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6170 return convert (type, tem);
6176 if (integer_all_onesp (arg0))
6177 return omit_one_operand (type, arg0, arg1);
6181 /* Optimize -1 >> x for arithmetic right shifts. */
6182 if (integer_all_onesp (arg0) && ! TREE_UNSIGNED (type))
6183 return omit_one_operand (type, arg0, arg1);
6184 /* ... fall through ... */
6188 if (integer_zerop (arg1))
6189 return non_lvalue (convert (type, arg0));
6190 if (integer_zerop (arg0))
6191 return omit_one_operand (type, arg0, arg1);
6193 /* Since negative shift count is not well-defined,
6194 don't try to compute it in the compiler. */
6195 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
6197 /* Rewrite an LROTATE_EXPR by a constant into an
6198 RROTATE_EXPR by a new constant. */
6199 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
6201 TREE_SET_CODE (t, RROTATE_EXPR);
6202 code = RROTATE_EXPR;
6203 TREE_OPERAND (t, 1) = arg1
6206 convert (TREE_TYPE (arg1),
6207 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
6209 if (tree_int_cst_sgn (arg1) < 0)
6213 /* If we have a rotate of a bit operation with the rotate count and
6214 the second operand of the bit operation both constant,
6215 permute the two operations. */
6216 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6217 && (TREE_CODE (arg0) == BIT_AND_EXPR
6218 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
6219 || TREE_CODE (arg0) == BIT_IOR_EXPR
6220 || TREE_CODE (arg0) == BIT_XOR_EXPR)
6221 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6222 return fold (build (TREE_CODE (arg0), type,
6223 fold (build (code, type,
6224 TREE_OPERAND (arg0, 0), arg1)),
6225 fold (build (code, type,
6226 TREE_OPERAND (arg0, 1), arg1))));
6228 /* Two consecutive rotates adding up to the width of the mode can
6230 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6231 && TREE_CODE (arg0) == RROTATE_EXPR
6232 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6233 && TREE_INT_CST_HIGH (arg1) == 0
6234 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
6235 && ((TREE_INT_CST_LOW (arg1)
6236 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
6237 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
6238 return TREE_OPERAND (arg0, 0);
6243 if (operand_equal_p (arg0, arg1, 0))
6244 return omit_one_operand (type, arg0, arg1);
6245 if (INTEGRAL_TYPE_P (type)
6246 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
6247 return omit_one_operand (type, arg1, arg0);
6251 if (operand_equal_p (arg0, arg1, 0))
6252 return omit_one_operand (type, arg0, arg1);
6253 if (INTEGRAL_TYPE_P (type)
6254 && TYPE_MAX_VALUE (type)
6255 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
6256 return omit_one_operand (type, arg1, arg0);
6259 case TRUTH_NOT_EXPR:
6260 /* Note that the operand of this must be an int
6261 and its values must be 0 or 1.
6262 ("true" is a fixed value perhaps depending on the language,
6263 but we don't handle values other than 1 correctly yet.) */
6264 tem = invert_truthvalue (arg0);
6265 /* Avoid infinite recursion. */
6266 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
6268 return convert (type, tem);
6270 case TRUTH_ANDIF_EXPR:
6271 /* Note that the operands of this must be ints
6272 and their values must be 0 or 1.
6273 ("true" is a fixed value perhaps depending on the language.) */
6274 /* If first arg is constant zero, return it. */
6275 if (integer_zerop (arg0))
6276 return convert (type, arg0);
6277 case TRUTH_AND_EXPR:
6278 /* If either arg is constant true, drop it. */
6279 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6280 return non_lvalue (convert (type, arg1));
6281 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
6282 /* Preserve sequence points. */
6283 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6284 return non_lvalue (convert (type, arg0));
6285 /* If second arg is constant zero, result is zero, but first arg
6286 must be evaluated. */
6287 if (integer_zerop (arg1))
6288 return omit_one_operand (type, arg1, arg0);
6289 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
6290 case will be handled here. */
6291 if (integer_zerop (arg0))
6292 return omit_one_operand (type, arg0, arg1);
6295 /* We only do these simplifications if we are optimizing. */
6299 /* Check for things like (A || B) && (A || C). We can convert this
6300 to A || (B && C). Note that either operator can be any of the four
6301 truth and/or operations and the transformation will still be
6302 valid. Also note that we only care about order for the
6303 ANDIF and ORIF operators. If B contains side effects, this
6304 might change the truth-value of A. */
6305 if (TREE_CODE (arg0) == TREE_CODE (arg1)
6306 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
6307 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
6308 || TREE_CODE (arg0) == TRUTH_AND_EXPR
6309 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
6310 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
6312 tree a00 = TREE_OPERAND (arg0, 0);
6313 tree a01 = TREE_OPERAND (arg0, 1);
6314 tree a10 = TREE_OPERAND (arg1, 0);
6315 tree a11 = TREE_OPERAND (arg1, 1);
6316 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
6317 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
6318 && (code == TRUTH_AND_EXPR
6319 || code == TRUTH_OR_EXPR));
6321 if (operand_equal_p (a00, a10, 0))
6322 return fold (build (TREE_CODE (arg0), type, a00,
6323 fold (build (code, type, a01, a11))));
6324 else if (commutative && operand_equal_p (a00, a11, 0))
6325 return fold (build (TREE_CODE (arg0), type, a00,
6326 fold (build (code, type, a01, a10))));
6327 else if (commutative && operand_equal_p (a01, a10, 0))
6328 return fold (build (TREE_CODE (arg0), type, a01,
6329 fold (build (code, type, a00, a11))));
6331 /* This case if tricky because we must either have commutative
6332 operators or else A10 must not have side-effects. */
6334 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
6335 && operand_equal_p (a01, a11, 0))
6336 return fold (build (TREE_CODE (arg0), type,
6337 fold (build (code, type, a00, a10)),
6341 /* See if we can build a range comparison. */
6342 if (0 != (tem = fold_range_test (t)))
6345 /* Check for the possibility of merging component references. If our
6346 lhs is another similar operation, try to merge its rhs with our
6347 rhs. Then try to merge our lhs and rhs. */
6348 if (TREE_CODE (arg0) == code
6349 && 0 != (tem = fold_truthop (code, type,
6350 TREE_OPERAND (arg0, 1), arg1)))
6351 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6353 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
6358 case TRUTH_ORIF_EXPR:
6359 /* Note that the operands of this must be ints
6360 and their values must be 0 or true.
6361 ("true" is a fixed value perhaps depending on the language.) */
6362 /* If first arg is constant true, return it. */
6363 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6364 return convert (type, arg0);
6366 /* If either arg is constant zero, drop it. */
6367 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
6368 return non_lvalue (convert (type, arg1));
6369 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
6370 /* Preserve sequence points. */
6371 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6372 return non_lvalue (convert (type, arg0));
6373 /* If second arg is constant true, result is true, but we must
6374 evaluate first arg. */
6375 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
6376 return omit_one_operand (type, arg1, arg0);
6377 /* Likewise for first arg, but note this only occurs here for
6379 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6380 return omit_one_operand (type, arg0, arg1);
6383 case TRUTH_XOR_EXPR:
6384 /* If either arg is constant zero, drop it. */
6385 if (integer_zerop (arg0))
6386 return non_lvalue (convert (type, arg1));
6387 if (integer_zerop (arg1))
6388 return non_lvalue (convert (type, arg0));
6389 /* If either arg is constant true, this is a logical inversion. */
6390 if (integer_onep (arg0))
6391 return non_lvalue (convert (type, invert_truthvalue (arg1)));
6392 if (integer_onep (arg1))
6393 return non_lvalue (convert (type, invert_truthvalue (arg0)));
6402 /* If one arg is a real or integer constant, put it last. */
6403 if ((TREE_CODE (arg0) == INTEGER_CST
6404 && TREE_CODE (arg1) != INTEGER_CST)
6405 || (TREE_CODE (arg0) == REAL_CST
6406 && TREE_CODE (arg0) != REAL_CST))
6408 TREE_OPERAND (t, 0) = arg1;
6409 TREE_OPERAND (t, 1) = arg0;
6410 arg0 = TREE_OPERAND (t, 0);
6411 arg1 = TREE_OPERAND (t, 1);
6412 code = swap_tree_comparison (code);
6413 TREE_SET_CODE (t, code);
6416 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
6418 tree targ0 = strip_float_extensions (arg0);
6419 tree targ1 = strip_float_extensions (arg1);
6420 tree newtype = TREE_TYPE (targ0);
6422 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
6423 newtype = TREE_TYPE (targ1);
6425 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
6426 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
6427 return fold (build (code, type, convert (newtype, targ0),
6428 convert (newtype, targ1)));
6430 /* (-a) CMP (-b) -> b CMP a */
6431 if (TREE_CODE (arg0) == NEGATE_EXPR
6432 && TREE_CODE (arg1) == NEGATE_EXPR)
6433 return fold (build (code, type, TREE_OPERAND (arg1, 0),
6434 TREE_OPERAND (arg0, 0)));
6436 if (TREE_CODE (arg1) == REAL_CST)
6438 REAL_VALUE_TYPE cst;
6439 cst = TREE_REAL_CST (arg1);
6441 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6442 if (TREE_CODE (arg0) == NEGATE_EXPR)
6444 fold (build (swap_tree_comparison (code), type,
6445 TREE_OPERAND (arg0, 0),
6446 build_real (TREE_TYPE (arg1),
6447 REAL_VALUE_NEGATE (cst))));
6449 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6450 /* a CMP (-0) -> a CMP 0 */
6451 if (REAL_VALUE_MINUS_ZERO (cst))
6452 return fold (build (code, type, arg0,
6453 build_real (TREE_TYPE (arg1), dconst0)));
6455 /* x != NaN is always true, other ops are always false. */
6456 if (REAL_VALUE_ISNAN (cst)
6457 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
6459 t = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
6460 return omit_one_operand (type, convert (type, t), arg0);
6463 /* Fold comparisons against infinity. */
6464 if (REAL_VALUE_ISINF (cst))
6466 tem = fold_inf_compare (code, type, arg0, arg1);
6467 if (tem != NULL_TREE)
6472 /* If this is a comparison of a real constant with a PLUS_EXPR
6473 or a MINUS_EXPR of a real constant, we can convert it into a
6474 comparison with a revised real constant as long as no overflow
6475 occurs when unsafe_math_optimizations are enabled. */
6476 if (flag_unsafe_math_optimizations
6477 && TREE_CODE (arg1) == REAL_CST
6478 && (TREE_CODE (arg0) == PLUS_EXPR
6479 || TREE_CODE (arg0) == MINUS_EXPR)
6480 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6481 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6482 ? MINUS_EXPR : PLUS_EXPR,
6483 arg1, TREE_OPERAND (arg0, 1), 0))
6484 && ! TREE_CONSTANT_OVERFLOW (tem))
6485 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6487 /* Likewise, we can simplify a comparison of a real constant with
6488 a MINUS_EXPR whose first operand is also a real constant, i.e.
6489 (c1 - x) < c2 becomes x > c1-c2. */
6490 if (flag_unsafe_math_optimizations
6491 && TREE_CODE (arg1) == REAL_CST
6492 && TREE_CODE (arg0) == MINUS_EXPR
6493 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
6494 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
6496 && ! TREE_CONSTANT_OVERFLOW (tem))
6497 return fold (build (swap_tree_comparison (code), type,
6498 TREE_OPERAND (arg0, 1), tem));
6500 /* Fold comparisons against built-in math functions. */
6501 if (TREE_CODE (arg1) == REAL_CST
6502 && flag_unsafe_math_optimizations
6503 && ! flag_errno_math)
6505 enum built_in_function fcode = builtin_mathfn_code (arg0);
6507 if (fcode != END_BUILTINS)
6509 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
6510 if (tem != NULL_TREE)
6516 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6517 First, see if one arg is constant; find the constant arg
6518 and the other one. */
6520 tree constop = 0, varop = NULL_TREE;
6521 int constopnum = -1;
6523 if (TREE_CONSTANT (arg1))
6524 constopnum = 1, constop = arg1, varop = arg0;
6525 if (TREE_CONSTANT (arg0))
6526 constopnum = 0, constop = arg0, varop = arg1;
6528 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
6530 /* This optimization is invalid for ordered comparisons
6531 if CONST+INCR overflows or if foo+incr might overflow.
6532 This optimization is invalid for floating point due to rounding.
6533 For pointer types we assume overflow doesn't happen. */
6534 if (POINTER_TYPE_P (TREE_TYPE (varop))
6535 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6536 && (code == EQ_EXPR || code == NE_EXPR)))
6539 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
6540 constop, TREE_OPERAND (varop, 1)));
6542 /* Do not overwrite the current varop to be a preincrement,
6543 create a new node so that we won't confuse our caller who
6544 might create trees and throw them away, reusing the
6545 arguments that they passed to build. This shows up in
6546 the THEN or ELSE parts of ?: being postincrements. */
6547 varop = build (PREINCREMENT_EXPR, TREE_TYPE (varop),
6548 TREE_OPERAND (varop, 0),
6549 TREE_OPERAND (varop, 1));
6551 /* If VAROP is a reference to a bitfield, we must mask
6552 the constant by the width of the field. */
6553 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6554 && DECL_BIT_FIELD(TREE_OPERAND
6555 (TREE_OPERAND (varop, 0), 1)))
6558 = TREE_INT_CST_LOW (DECL_SIZE
6560 (TREE_OPERAND (varop, 0), 1)));
6561 tree mask, unsigned_type;
6562 unsigned int precision;
6563 tree folded_compare;
6565 /* First check whether the comparison would come out
6566 always the same. If we don't do that we would
6567 change the meaning with the masking. */
6568 if (constopnum == 0)
6569 folded_compare = fold (build (code, type, constop,
6570 TREE_OPERAND (varop, 0)));
6572 folded_compare = fold (build (code, type,
6573 TREE_OPERAND (varop, 0),
6575 if (integer_zerop (folded_compare)
6576 || integer_onep (folded_compare))
6577 return omit_one_operand (type, folded_compare, varop);
6579 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
6580 precision = TYPE_PRECISION (unsigned_type);
6581 mask = build_int_2 (~0, ~0);
6582 TREE_TYPE (mask) = unsigned_type;
6583 force_fit_type (mask, 0);
6584 mask = const_binop (RSHIFT_EXPR, mask,
6585 size_int (precision - size), 0);
6586 newconst = fold (build (BIT_AND_EXPR,
6587 TREE_TYPE (varop), newconst,
6588 convert (TREE_TYPE (varop),
6592 t = build (code, type,
6593 (constopnum == 0) ? newconst : varop,
6594 (constopnum == 1) ? newconst : varop);
6598 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
6600 if (POINTER_TYPE_P (TREE_TYPE (varop))
6601 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6602 && (code == EQ_EXPR || code == NE_EXPR)))
6605 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
6606 constop, TREE_OPERAND (varop, 1)));
6608 /* Do not overwrite the current varop to be a predecrement,
6609 create a new node so that we won't confuse our caller who
6610 might create trees and throw them away, reusing the
6611 arguments that they passed to build. This shows up in
6612 the THEN or ELSE parts of ?: being postdecrements. */
6613 varop = build (PREDECREMENT_EXPR, TREE_TYPE (varop),
6614 TREE_OPERAND (varop, 0),
6615 TREE_OPERAND (varop, 1));
6617 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6618 && DECL_BIT_FIELD(TREE_OPERAND
6619 (TREE_OPERAND (varop, 0), 1)))
6622 = TREE_INT_CST_LOW (DECL_SIZE
6624 (TREE_OPERAND (varop, 0), 1)));
6625 tree mask, unsigned_type;
6626 unsigned int precision;
6627 tree folded_compare;
6629 if (constopnum == 0)
6630 folded_compare = fold (build (code, type, constop,
6631 TREE_OPERAND (varop, 0)));
6633 folded_compare = fold (build (code, type,
6634 TREE_OPERAND (varop, 0),
6636 if (integer_zerop (folded_compare)
6637 || integer_onep (folded_compare))
6638 return omit_one_operand (type, folded_compare, varop);
6640 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
6641 precision = TYPE_PRECISION (unsigned_type);
6642 mask = build_int_2 (~0, ~0);
6643 TREE_TYPE (mask) = TREE_TYPE (varop);
6644 force_fit_type (mask, 0);
6645 mask = const_binop (RSHIFT_EXPR, mask,
6646 size_int (precision - size), 0);
6647 newconst = fold (build (BIT_AND_EXPR,
6648 TREE_TYPE (varop), newconst,
6649 convert (TREE_TYPE (varop),
6653 t = build (code, type,
6654 (constopnum == 0) ? newconst : varop,
6655 (constopnum == 1) ? newconst : varop);
6661 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
6662 This transformation affects the cases which are handled in later
6663 optimizations involving comparisons with non-negative constants. */
6664 if (TREE_CODE (arg1) == INTEGER_CST
6665 && TREE_CODE (arg0) != INTEGER_CST
6666 && tree_int_cst_sgn (arg1) > 0)
6672 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6673 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6678 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6679 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6687 /* Comparisons with the highest or lowest possible integer of
6688 the specified size will have known values. */
6690 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
6692 if (TREE_CODE (arg1) == INTEGER_CST
6693 && ! TREE_CONSTANT_OVERFLOW (arg1)
6694 && width <= HOST_BITS_PER_WIDE_INT
6695 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6696 || POINTER_TYPE_P (TREE_TYPE (arg1))))
6698 unsigned HOST_WIDE_INT signed_max;
6699 unsigned HOST_WIDE_INT max, min;
6701 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
6703 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6705 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
6711 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
6714 if (TREE_INT_CST_HIGH (arg1) == 0
6715 && TREE_INT_CST_LOW (arg1) == max)
6719 return omit_one_operand (type,
6720 convert (type, integer_zero_node),
6724 TREE_SET_CODE (t, EQ_EXPR);
6727 return omit_one_operand (type,
6728 convert (type, integer_one_node),
6732 TREE_SET_CODE (t, NE_EXPR);
6735 /* The GE_EXPR and LT_EXPR cases above are not normally
6736 reached because of previous transformations. */
6741 else if (TREE_INT_CST_HIGH (arg1) == 0
6742 && TREE_INT_CST_LOW (arg1) == max - 1)
6747 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
6748 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6752 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
6753 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6758 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
6759 && TREE_INT_CST_LOW (arg1) == min)
6763 return omit_one_operand (type,
6764 convert (type, integer_zero_node),
6768 TREE_SET_CODE (t, EQ_EXPR);
6772 return omit_one_operand (type,
6773 convert (type, integer_one_node),
6777 TREE_SET_CODE (t, NE_EXPR);
6783 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
6784 && TREE_INT_CST_LOW (arg1) == min + 1)
6789 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6790 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6794 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6795 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6801 else if (TREE_INT_CST_HIGH (arg1) == 0
6802 && TREE_INT_CST_LOW (arg1) == signed_max
6803 && TREE_UNSIGNED (TREE_TYPE (arg1))
6804 /* signed_type does not work on pointer types. */
6805 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
6807 /* The following case also applies to X < signed_max+1
6808 and X >= signed_max+1 because previous transformations. */
6809 if (code == LE_EXPR || code == GT_EXPR)
6812 st0 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg0));
6813 st1 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg1));
6815 (build (code == LE_EXPR ? GE_EXPR: LT_EXPR,
6816 type, convert (st0, arg0),
6817 convert (st1, integer_zero_node)));
6823 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6824 a MINUS_EXPR of a constant, we can convert it into a comparison with
6825 a revised constant as long as no overflow occurs. */
6826 if ((code == EQ_EXPR || code == NE_EXPR)
6827 && TREE_CODE (arg1) == INTEGER_CST
6828 && (TREE_CODE (arg0) == PLUS_EXPR
6829 || TREE_CODE (arg0) == MINUS_EXPR)
6830 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6831 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6832 ? MINUS_EXPR : PLUS_EXPR,
6833 arg1, TREE_OPERAND (arg0, 1), 0))
6834 && ! TREE_CONSTANT_OVERFLOW (tem))
6835 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6837 /* Similarly for a NEGATE_EXPR. */
6838 else if ((code == EQ_EXPR || code == NE_EXPR)
6839 && TREE_CODE (arg0) == NEGATE_EXPR
6840 && TREE_CODE (arg1) == INTEGER_CST
6841 && 0 != (tem = negate_expr (arg1))
6842 && TREE_CODE (tem) == INTEGER_CST
6843 && ! TREE_CONSTANT_OVERFLOW (tem))
6844 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6846 /* If we have X - Y == 0, we can convert that to X == Y and similarly
6847 for !=. Don't do this for ordered comparisons due to overflow. */
6848 else if ((code == NE_EXPR || code == EQ_EXPR)
6849 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
6850 return fold (build (code, type,
6851 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
6853 /* If we are widening one operand of an integer comparison,
6854 see if the other operand is similarly being widened. Perhaps we
6855 can do the comparison in the narrower type. */
6856 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
6857 && TREE_CODE (arg0) == NOP_EXPR
6858 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
6859 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
6860 && (TREE_TYPE (t1) == TREE_TYPE (tem)
6861 || (TREE_CODE (t1) == INTEGER_CST
6862 && int_fits_type_p (t1, TREE_TYPE (tem)))))
6863 return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
6865 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
6866 constant, we can simplify it. */
6867 else if (TREE_CODE (arg1) == INTEGER_CST
6868 && (TREE_CODE (arg0) == MIN_EXPR
6869 || TREE_CODE (arg0) == MAX_EXPR)
6870 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6871 return optimize_minmax_comparison (t);
6873 /* If we are comparing an ABS_EXPR with a constant, we can
6874 convert all the cases into explicit comparisons, but they may
6875 well not be faster than doing the ABS and one comparison.
6876 But ABS (X) <= C is a range comparison, which becomes a subtraction
6877 and a comparison, and is probably faster. */
6878 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6879 && TREE_CODE (arg0) == ABS_EXPR
6880 && ! TREE_SIDE_EFFECTS (arg0)
6881 && (0 != (tem = negate_expr (arg1)))
6882 && TREE_CODE (tem) == INTEGER_CST
6883 && ! TREE_CONSTANT_OVERFLOW (tem))
6884 return fold (build (TRUTH_ANDIF_EXPR, type,
6885 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
6886 build (LE_EXPR, type,
6887 TREE_OPERAND (arg0, 0), arg1)));
6889 /* If this is an EQ or NE comparison with zero and ARG0 is
6890 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
6891 two operations, but the latter can be done in one less insn
6892 on machines that have only two-operand insns or on which a
6893 constant cannot be the first operand. */
6894 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
6895 && TREE_CODE (arg0) == BIT_AND_EXPR)
6897 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
6898 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
6900 fold (build (code, type,
6901 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6903 TREE_TYPE (TREE_OPERAND (arg0, 0)),
6904 TREE_OPERAND (arg0, 1),
6905 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
6906 convert (TREE_TYPE (arg0),
6909 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
6910 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
6912 fold (build (code, type,
6913 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6915 TREE_TYPE (TREE_OPERAND (arg0, 1)),
6916 TREE_OPERAND (arg0, 0),
6917 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
6918 convert (TREE_TYPE (arg0),
6923 /* If this is an NE or EQ comparison of zero against the result of a
6924 signed MOD operation whose second operand is a power of 2, make
6925 the MOD operation unsigned since it is simpler and equivalent. */
6926 if ((code == NE_EXPR || code == EQ_EXPR)
6927 && integer_zerop (arg1)
6928 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
6929 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
6930 || TREE_CODE (arg0) == CEIL_MOD_EXPR
6931 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
6932 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
6933 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6935 tree newtype = (*lang_hooks.types.unsigned_type) (TREE_TYPE (arg0));
6936 tree newmod = build (TREE_CODE (arg0), newtype,
6937 convert (newtype, TREE_OPERAND (arg0, 0)),
6938 convert (newtype, TREE_OPERAND (arg0, 1)));
6940 return build (code, type, newmod, convert (newtype, arg1));
6943 /* If this is an NE comparison of zero with an AND of one, remove the
6944 comparison since the AND will give the correct value. */
6945 if (code == NE_EXPR && integer_zerop (arg1)
6946 && TREE_CODE (arg0) == BIT_AND_EXPR
6947 && integer_onep (TREE_OPERAND (arg0, 1)))
6948 return convert (type, arg0);
6950 /* If we have (A & C) == C where C is a power of 2, convert this into
6951 (A & C) != 0. Similarly for NE_EXPR. */
6952 if ((code == EQ_EXPR || code == NE_EXPR)
6953 && TREE_CODE (arg0) == BIT_AND_EXPR
6954 && integer_pow2p (TREE_OPERAND (arg0, 1))
6955 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
6956 return fold (build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
6957 arg0, integer_zero_node));
6959 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6960 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6961 if ((code == EQ_EXPR || code == NE_EXPR)
6962 && TREE_CODE (arg0) == BIT_AND_EXPR
6963 && integer_zerop (arg1))
6965 tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0),
6966 TREE_OPERAND (arg0, 1));
6967 if (arg00 != NULL_TREE)
6969 tree stype = (*lang_hooks.types.signed_type) (TREE_TYPE (arg00));
6970 return fold (build (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
6971 convert (stype, arg00),
6972 convert (stype, integer_zero_node)));
6976 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
6977 and similarly for >= into !=. */
6978 if ((code == LT_EXPR || code == GE_EXPR)
6979 && TREE_UNSIGNED (TREE_TYPE (arg0))
6980 && TREE_CODE (arg1) == LSHIFT_EXPR
6981 && integer_onep (TREE_OPERAND (arg1, 0)))
6982 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6983 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6984 TREE_OPERAND (arg1, 1)),
6985 convert (TREE_TYPE (arg0), integer_zero_node));
6987 else if ((code == LT_EXPR || code == GE_EXPR)
6988 && TREE_UNSIGNED (TREE_TYPE (arg0))
6989 && (TREE_CODE (arg1) == NOP_EXPR
6990 || TREE_CODE (arg1) == CONVERT_EXPR)
6991 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
6992 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
6994 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6995 convert (TREE_TYPE (arg0),
6996 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6997 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
6998 convert (TREE_TYPE (arg0), integer_zero_node));
7000 /* Simplify comparison of something with itself. (For IEEE
7001 floating-point, we can only do some of these simplifications.) */
7002 if (operand_equal_p (arg0, arg1, 0))
7009 if (! FLOAT_TYPE_P (TREE_TYPE (arg0)))
7010 return constant_boolean_node (1, type);
7012 TREE_SET_CODE (t, code);
7016 /* For NE, we can only do this simplification if integer. */
7017 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
7019 /* ... fall through ... */
7022 return constant_boolean_node (0, type);
7028 /* If we are comparing an expression that just has comparisons
7029 of two integer values, arithmetic expressions of those comparisons,
7030 and constants, we can simplify it. There are only three cases
7031 to check: the two values can either be equal, the first can be
7032 greater, or the second can be greater. Fold the expression for
7033 those three values. Since each value must be 0 or 1, we have
7034 eight possibilities, each of which corresponds to the constant 0
7035 or 1 or one of the six possible comparisons.
7037 This handles common cases like (a > b) == 0 but also handles
7038 expressions like ((x > y) - (y > x)) > 0, which supposedly
7039 occur in macroized code. */
7041 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
7043 tree cval1 = 0, cval2 = 0;
7046 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
7047 /* Don't handle degenerate cases here; they should already
7048 have been handled anyway. */
7049 && cval1 != 0 && cval2 != 0
7050 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
7051 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
7052 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
7053 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
7054 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
7055 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
7056 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
7058 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
7059 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
7061 /* We can't just pass T to eval_subst in case cval1 or cval2
7062 was the same as ARG1. */
7065 = fold (build (code, type,
7066 eval_subst (arg0, cval1, maxval, cval2, minval),
7069 = fold (build (code, type,
7070 eval_subst (arg0, cval1, maxval, cval2, maxval),
7073 = fold (build (code, type,
7074 eval_subst (arg0, cval1, minval, cval2, maxval),
7077 /* All three of these results should be 0 or 1. Confirm they
7078 are. Then use those values to select the proper code
7081 if ((integer_zerop (high_result)
7082 || integer_onep (high_result))
7083 && (integer_zerop (equal_result)
7084 || integer_onep (equal_result))
7085 && (integer_zerop (low_result)
7086 || integer_onep (low_result)))
7088 /* Make a 3-bit mask with the high-order bit being the
7089 value for `>', the next for '=', and the low for '<'. */
7090 switch ((integer_onep (high_result) * 4)
7091 + (integer_onep (equal_result) * 2)
7092 + integer_onep (low_result))
7096 return omit_one_operand (type, integer_zero_node, arg0);
7117 return omit_one_operand (type, integer_one_node, arg0);
7120 t = build (code, type, cval1, cval2);
7122 return save_expr (t);
7129 /* If this is a comparison of a field, we may be able to simplify it. */
7130 if (((TREE_CODE (arg0) == COMPONENT_REF
7131 && (*lang_hooks.can_use_bit_fields_p) ())
7132 || TREE_CODE (arg0) == BIT_FIELD_REF)
7133 && (code == EQ_EXPR || code == NE_EXPR)
7134 /* Handle the constant case even without -O
7135 to make sure the warnings are given. */
7136 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
7138 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
7142 /* If this is a comparison of complex values and either or both sides
7143 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
7144 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
7145 This may prevent needless evaluations. */
7146 if ((code == EQ_EXPR || code == NE_EXPR)
7147 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
7148 && (TREE_CODE (arg0) == COMPLEX_EXPR
7149 || TREE_CODE (arg1) == COMPLEX_EXPR
7150 || TREE_CODE (arg0) == COMPLEX_CST
7151 || TREE_CODE (arg1) == COMPLEX_CST))
7153 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
7154 tree real0, imag0, real1, imag1;
7156 arg0 = save_expr (arg0);
7157 arg1 = save_expr (arg1);
7158 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
7159 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
7160 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
7161 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
7163 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
7166 fold (build (code, type, real0, real1)),
7167 fold (build (code, type, imag0, imag1))));
7170 /* Optimize comparisons of strlen vs zero to a compare of the
7171 first character of the string vs zero. To wit,
7172 strlen(ptr) == 0 => *ptr == 0
7173 strlen(ptr) != 0 => *ptr != 0
7174 Other cases should reduce to one of these two (or a constant)
7175 due to the return value of strlen being unsigned. */
7176 if ((code == EQ_EXPR || code == NE_EXPR)
7177 && integer_zerop (arg1)
7178 && TREE_CODE (arg0) == CALL_EXPR
7179 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ADDR_EXPR)
7181 tree fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7184 if (TREE_CODE (fndecl) == FUNCTION_DECL
7185 && DECL_BUILT_IN (fndecl)
7186 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
7187 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
7188 && (arglist = TREE_OPERAND (arg0, 1))
7189 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
7190 && ! TREE_CHAIN (arglist))
7191 return fold (build (code, type,
7192 build1 (INDIRECT_REF, char_type_node,
7193 TREE_VALUE(arglist)),
7194 integer_zero_node));
7197 /* From here on, the only cases we handle are when the result is
7198 known to be a constant.
7200 To compute GT, swap the arguments and do LT.
7201 To compute GE, do LT and invert the result.
7202 To compute LE, swap the arguments, do LT and invert the result.
7203 To compute NE, do EQ and invert the result.
7205 Therefore, the code below must handle only EQ and LT. */
7207 if (code == LE_EXPR || code == GT_EXPR)
7209 tem = arg0, arg0 = arg1, arg1 = tem;
7210 code = swap_tree_comparison (code);
7213 /* Note that it is safe to invert for real values here because we
7214 will check below in the one case that it matters. */
7218 if (code == NE_EXPR || code == GE_EXPR)
7221 code = invert_tree_comparison (code);
7224 /* Compute a result for LT or EQ if args permit;
7225 otherwise return T. */
7226 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
7228 if (code == EQ_EXPR)
7229 t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0);
7231 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
7232 ? INT_CST_LT_UNSIGNED (arg0, arg1)
7233 : INT_CST_LT (arg0, arg1)),
7237 #if 0 /* This is no longer useful, but breaks some real code. */
7238 /* Assume a nonexplicit constant cannot equal an explicit one,
7239 since such code would be undefined anyway.
7240 Exception: on sysvr4, using #pragma weak,
7241 a label can come out as 0. */
7242 else if (TREE_CODE (arg1) == INTEGER_CST
7243 && !integer_zerop (arg1)
7244 && TREE_CONSTANT (arg0)
7245 && TREE_CODE (arg0) == ADDR_EXPR
7247 t1 = build_int_2 (0, 0);
7249 /* Two real constants can be compared explicitly. */
7250 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
7252 /* If either operand is a NaN, the result is false with two
7253 exceptions: First, an NE_EXPR is true on NaNs, but that case
7254 is already handled correctly since we will be inverting the
7255 result for NE_EXPR. Second, if we had inverted a LE_EXPR
7256 or a GE_EXPR into a LT_EXPR, we must return true so that it
7257 will be inverted into false. */
7259 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
7260 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
7261 t1 = build_int_2 (invert && code == LT_EXPR, 0);
7263 else if (code == EQ_EXPR)
7264 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
7265 TREE_REAL_CST (arg1)),
7268 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
7269 TREE_REAL_CST (arg1)),
7273 if (t1 == NULL_TREE)
7277 TREE_INT_CST_LOW (t1) ^= 1;
7279 TREE_TYPE (t1) = type;
7280 if (TREE_CODE (type) == BOOLEAN_TYPE)
7281 return (*lang_hooks.truthvalue_conversion) (t1);
7285 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
7286 so all simple results must be passed through pedantic_non_lvalue. */
7287 if (TREE_CODE (arg0) == INTEGER_CST)
7288 return pedantic_non_lvalue
7289 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
7290 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
7291 return pedantic_omit_one_operand (type, arg1, arg0);
7293 /* If the second operand is zero, invert the comparison and swap
7294 the second and third operands. Likewise if the second operand
7295 is constant and the third is not or if the third operand is
7296 equivalent to the first operand of the comparison. */
7298 if (integer_zerop (arg1)
7299 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
7300 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
7301 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
7302 TREE_OPERAND (t, 2),
7303 TREE_OPERAND (arg0, 1))))
7305 /* See if this can be inverted. If it can't, possibly because
7306 it was a floating-point inequality comparison, don't do
7308 tem = invert_truthvalue (arg0);
7310 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7312 t = build (code, type, tem,
7313 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7315 /* arg1 should be the first argument of the new T. */
7316 arg1 = TREE_OPERAND (t, 1);
7321 /* If we have A op B ? A : C, we may be able to convert this to a
7322 simpler expression, depending on the operation and the values
7323 of B and C. Signed zeros prevent all of these transformations,
7324 for reasons given above each one. */
7326 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
7327 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
7328 arg1, TREE_OPERAND (arg0, 1))
7329 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
7331 tree arg2 = TREE_OPERAND (t, 2);
7332 enum tree_code comp_code = TREE_CODE (arg0);
7336 /* If we have A op 0 ? A : -A, consider applying the following
7339 A == 0? A : -A same as -A
7340 A != 0? A : -A same as A
7341 A >= 0? A : -A same as abs (A)
7342 A > 0? A : -A same as abs (A)
7343 A <= 0? A : -A same as -abs (A)
7344 A < 0? A : -A same as -abs (A)
7346 None of these transformations work for modes with signed
7347 zeros. If A is +/-0, the first two transformations will
7348 change the sign of the result (from +0 to -0, or vice
7349 versa). The last four will fix the sign of the result,
7350 even though the original expressions could be positive or
7351 negative, depending on the sign of A.
7353 Note that all these transformations are correct if A is
7354 NaN, since the two alternatives (A and -A) are also NaNs. */
7355 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
7356 ? real_zerop (TREE_OPERAND (arg0, 1))
7357 : integer_zerop (TREE_OPERAND (arg0, 1)))
7358 && TREE_CODE (arg2) == NEGATE_EXPR
7359 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
7367 (convert (TREE_TYPE (TREE_OPERAND (t, 1)),
7370 return pedantic_non_lvalue (convert (type, arg1));
7373 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7374 arg1 = convert ((*lang_hooks.types.signed_type)
7375 (TREE_TYPE (arg1)), arg1);
7376 return pedantic_non_lvalue
7377 (convert (type, fold (build1 (ABS_EXPR,
7378 TREE_TYPE (arg1), arg1))));
7381 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7382 arg1 = convert ((lang_hooks.types.signed_type)
7383 (TREE_TYPE (arg1)), arg1);
7384 return pedantic_non_lvalue
7385 (negate_expr (convert (type,
7386 fold (build1 (ABS_EXPR,
7393 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
7394 A == 0 ? A : 0 is always 0 unless A is -0. Note that
7395 both transformations are correct when A is NaN: A != 0
7396 is then true, and A == 0 is false. */
7398 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
7400 if (comp_code == NE_EXPR)
7401 return pedantic_non_lvalue (convert (type, arg1));
7402 else if (comp_code == EQ_EXPR)
7403 return pedantic_non_lvalue (convert (type, integer_zero_node));
7406 /* Try some transformations of A op B ? A : B.
7408 A == B? A : B same as B
7409 A != B? A : B same as A
7410 A >= B? A : B same as max (A, B)
7411 A > B? A : B same as max (B, A)
7412 A <= B? A : B same as min (A, B)
7413 A < B? A : B same as min (B, A)
7415 As above, these transformations don't work in the presence
7416 of signed zeros. For example, if A and B are zeros of
7417 opposite sign, the first two transformations will change
7418 the sign of the result. In the last four, the original
7419 expressions give different results for (A=+0, B=-0) and
7420 (A=-0, B=+0), but the transformed expressions do not.
7422 The first two transformations are correct if either A or B
7423 is a NaN. In the first transformation, the condition will
7424 be false, and B will indeed be chosen. In the case of the
7425 second transformation, the condition A != B will be true,
7426 and A will be chosen.
7428 The conversions to max() and min() are not correct if B is
7429 a number and A is not. The conditions in the original
7430 expressions will be false, so all four give B. The min()
7431 and max() versions would give a NaN instead. */
7432 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
7433 arg2, TREE_OPERAND (arg0, 0)))
7435 tree comp_op0 = TREE_OPERAND (arg0, 0);
7436 tree comp_op1 = TREE_OPERAND (arg0, 1);
7437 tree comp_type = TREE_TYPE (comp_op0);
7439 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
7440 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
7450 return pedantic_non_lvalue (convert (type, arg2));
7452 return pedantic_non_lvalue (convert (type, arg1));
7455 /* In C++ a ?: expression can be an lvalue, so put the
7456 operand which will be used if they are equal first
7457 so that we can convert this back to the
7458 corresponding COND_EXPR. */
7459 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
7460 return pedantic_non_lvalue
7461 (convert (type, fold (build (MIN_EXPR, comp_type,
7462 (comp_code == LE_EXPR
7463 ? comp_op0 : comp_op1),
7464 (comp_code == LE_EXPR
7465 ? comp_op1 : comp_op0)))));
7469 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
7470 return pedantic_non_lvalue
7471 (convert (type, fold (build (MAX_EXPR, comp_type,
7472 (comp_code == GE_EXPR
7473 ? comp_op0 : comp_op1),
7474 (comp_code == GE_EXPR
7475 ? comp_op1 : comp_op0)))));
7482 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
7483 we might still be able to simplify this. For example,
7484 if C1 is one less or one more than C2, this might have started
7485 out as a MIN or MAX and been transformed by this function.
7486 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
7488 if (INTEGRAL_TYPE_P (type)
7489 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7490 && TREE_CODE (arg2) == INTEGER_CST)
7494 /* We can replace A with C1 in this case. */
7495 arg1 = convert (type, TREE_OPERAND (arg0, 1));
7496 t = build (code, type, TREE_OPERAND (t, 0), arg1,
7497 TREE_OPERAND (t, 2));
7501 /* If C1 is C2 + 1, this is min(A, C2). */
7502 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7503 && operand_equal_p (TREE_OPERAND (arg0, 1),
7504 const_binop (PLUS_EXPR, arg2,
7505 integer_one_node, 0), 1))
7506 return pedantic_non_lvalue
7507 (fold (build (MIN_EXPR, type, arg1, arg2)));
7511 /* If C1 is C2 - 1, this is min(A, C2). */
7512 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7513 && operand_equal_p (TREE_OPERAND (arg0, 1),
7514 const_binop (MINUS_EXPR, arg2,
7515 integer_one_node, 0), 1))
7516 return pedantic_non_lvalue
7517 (fold (build (MIN_EXPR, type, arg1, arg2)));
7521 /* If C1 is C2 - 1, this is max(A, C2). */
7522 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7523 && operand_equal_p (TREE_OPERAND (arg0, 1),
7524 const_binop (MINUS_EXPR, arg2,
7525 integer_one_node, 0), 1))
7526 return pedantic_non_lvalue
7527 (fold (build (MAX_EXPR, type, arg1, arg2)));
7531 /* If C1 is C2 + 1, this is max(A, C2). */
7532 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7533 && operand_equal_p (TREE_OPERAND (arg0, 1),
7534 const_binop (PLUS_EXPR, arg2,
7535 integer_one_node, 0), 1))
7536 return pedantic_non_lvalue
7537 (fold (build (MAX_EXPR, type, arg1, arg2)));
7546 /* If the second operand is simpler than the third, swap them
7547 since that produces better jump optimization results. */
7548 if ((TREE_CONSTANT (arg1) || DECL_P (arg1)
7549 || TREE_CODE (arg1) == SAVE_EXPR)
7550 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
7551 || DECL_P (TREE_OPERAND (t, 2))
7552 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
7554 /* See if this can be inverted. If it can't, possibly because
7555 it was a floating-point inequality comparison, don't do
7557 tem = invert_truthvalue (arg0);
7559 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7561 t = build (code, type, tem,
7562 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7564 /* arg1 should be the first argument of the new T. */
7565 arg1 = TREE_OPERAND (t, 1);
7570 /* Convert A ? 1 : 0 to simply A. */
7571 if (integer_onep (TREE_OPERAND (t, 1))
7572 && integer_zerop (TREE_OPERAND (t, 2))
7573 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7574 call to fold will try to move the conversion inside
7575 a COND, which will recurse. In that case, the COND_EXPR
7576 is probably the best choice, so leave it alone. */
7577 && type == TREE_TYPE (arg0))
7578 return pedantic_non_lvalue (arg0);
7580 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
7581 over COND_EXPR in cases such as floating point comparisons. */
7582 if (integer_zerop (TREE_OPERAND (t, 1))
7583 && integer_onep (TREE_OPERAND (t, 2))
7584 && truth_value_p (TREE_CODE (arg0)))
7585 return pedantic_non_lvalue (convert (type,
7586 invert_truthvalue (arg0)));
7588 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7589 operation is simply A & 2. */
7591 if (integer_zerop (TREE_OPERAND (t, 2))
7592 && TREE_CODE (arg0) == NE_EXPR
7593 && integer_zerop (TREE_OPERAND (arg0, 1))
7594 && integer_pow2p (arg1)
7595 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
7596 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
7598 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
7600 /* Convert A ? B : 0 into A && B if A and B are truth values. */
7601 if (integer_zerop (TREE_OPERAND (t, 2))
7602 && truth_value_p (TREE_CODE (arg0))
7603 && truth_value_p (TREE_CODE (arg1)))
7604 return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR, type,
7607 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
7608 if (integer_onep (TREE_OPERAND (t, 2))
7609 && truth_value_p (TREE_CODE (arg0))
7610 && truth_value_p (TREE_CODE (arg1)))
7612 /* Only perform transformation if ARG0 is easily inverted. */
7613 tem = invert_truthvalue (arg0);
7614 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7615 return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR, type,
7622 /* When pedantic, a compound expression can be neither an lvalue
7623 nor an integer constant expression. */
7624 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
7626 /* Don't let (0, 0) be null pointer constant. */
7627 if (integer_zerop (arg1))
7628 return build1 (NOP_EXPR, type, arg1);
7629 return convert (type, arg1);
7633 return build_complex (type, arg0, arg1);
7637 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7639 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7640 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7641 TREE_OPERAND (arg0, 1));
7642 else if (TREE_CODE (arg0) == COMPLEX_CST)
7643 return TREE_REALPART (arg0);
7644 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7645 return fold (build (TREE_CODE (arg0), type,
7646 fold (build1 (REALPART_EXPR, type,
7647 TREE_OPERAND (arg0, 0))),
7648 fold (build1 (REALPART_EXPR,
7649 type, TREE_OPERAND (arg0, 1)))));
7653 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7654 return convert (type, integer_zero_node);
7655 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7656 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7657 TREE_OPERAND (arg0, 0));
7658 else if (TREE_CODE (arg0) == COMPLEX_CST)
7659 return TREE_IMAGPART (arg0);
7660 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7661 return fold (build (TREE_CODE (arg0), type,
7662 fold (build1 (IMAGPART_EXPR, type,
7663 TREE_OPERAND (arg0, 0))),
7664 fold (build1 (IMAGPART_EXPR, type,
7665 TREE_OPERAND (arg0, 1)))));
7668 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7670 case CLEANUP_POINT_EXPR:
7671 if (! has_cleanups (arg0))
7672 return TREE_OPERAND (t, 0);
7675 enum tree_code code0 = TREE_CODE (arg0);
7676 int kind0 = TREE_CODE_CLASS (code0);
7677 tree arg00 = TREE_OPERAND (arg0, 0);
7680 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
7681 return fold (build1 (code0, type,
7682 fold (build1 (CLEANUP_POINT_EXPR,
7683 TREE_TYPE (arg00), arg00))));
7685 if (kind0 == '<' || kind0 == '2'
7686 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
7687 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
7688 || code0 == TRUTH_XOR_EXPR)
7690 arg01 = TREE_OPERAND (arg0, 1);
7692 if (TREE_CONSTANT (arg00)
7693 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
7694 && ! has_cleanups (arg00)))
7695 return fold (build (code0, type, arg00,
7696 fold (build1 (CLEANUP_POINT_EXPR,
7697 TREE_TYPE (arg01), arg01))));
7699 if (TREE_CONSTANT (arg01))
7700 return fold (build (code0, type,
7701 fold (build1 (CLEANUP_POINT_EXPR,
7702 TREE_TYPE (arg00), arg00)),
7710 /* Check for a built-in function. */
7711 if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR
7712 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr, 0), 0))
7714 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr, 0), 0)))
7716 tree tmp = fold_builtin (expr);
7724 } /* switch (code) */
7727 /* Determine if first argument is a multiple of second argument. Return 0 if
7728 it is not, or we cannot easily determined it to be.
7730 An example of the sort of thing we care about (at this point; this routine
7731 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7732 fold cases do now) is discovering that
7734 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7740 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7742 This code also handles discovering that
7744 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7746 is a multiple of 8 so we don't have to worry about dealing with a
7749 Note that we *look* inside a SAVE_EXPR only to determine how it was
7750 calculated; it is not safe for fold to do much of anything else with the
7751 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7752 at run time. For example, the latter example above *cannot* be implemented
7753 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7754 evaluation time of the original SAVE_EXPR is not necessarily the same at
7755 the time the new expression is evaluated. The only optimization of this
7756 sort that would be valid is changing
7758 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7762 SAVE_EXPR (I) * SAVE_EXPR (J)
7764 (where the same SAVE_EXPR (J) is used in the original and the
7765 transformed version). */
7768 multiple_of_p (type, top, bottom)
7773 if (operand_equal_p (top, bottom, 0))
7776 if (TREE_CODE (type) != INTEGER_TYPE)
7779 switch (TREE_CODE (top))
7782 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7783 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7787 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7788 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7791 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
7795 op1 = TREE_OPERAND (top, 1);
7796 /* const_binop may not detect overflow correctly,
7797 so check for it explicitly here. */
7798 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
7799 > TREE_INT_CST_LOW (op1)
7800 && TREE_INT_CST_HIGH (op1) == 0
7801 && 0 != (t1 = convert (type,
7802 const_binop (LSHIFT_EXPR, size_one_node,
7804 && ! TREE_OVERFLOW (t1))
7805 return multiple_of_p (type, t1, bottom);
7810 /* Can't handle conversions from non-integral or wider integral type. */
7811 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
7812 || (TYPE_PRECISION (type)
7813 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
7816 /* .. fall through ... */
7819 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
7822 if (TREE_CODE (bottom) != INTEGER_CST
7823 || (TREE_UNSIGNED (type)
7824 && (tree_int_cst_sgn (top) < 0
7825 || tree_int_cst_sgn (bottom) < 0)))
7827 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
7835 /* Return true if `t' is known to be non-negative. */
7838 tree_expr_nonnegative_p (t)
7841 switch (TREE_CODE (t))
7851 /* These are undefined at zero. This is true even if
7852 C[LT]Z_DEFINED_VALUE_AT_ZERO is set, since what we're
7853 computing here is a user-visible property. */
7857 return tree_int_cst_sgn (t) >= 0;
7858 case TRUNC_DIV_EXPR:
7860 case FLOOR_DIV_EXPR:
7861 case ROUND_DIV_EXPR:
7862 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
7863 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7864 case TRUNC_MOD_EXPR:
7866 case FLOOR_MOD_EXPR:
7867 case ROUND_MOD_EXPR:
7868 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
7870 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
7871 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
7873 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7875 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
7876 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7878 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
7879 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7881 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7883 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7885 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
7886 case NON_LVALUE_EXPR:
7887 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
7889 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
7892 if (truth_value_p (TREE_CODE (t)))
7893 /* Truth values evaluate to 0 or 1, which is nonnegative. */
7896 /* We don't know sign of `t', so be conservative and return false. */
7901 /* Return true if `r' is known to be non-negative.
7902 Only handles constants at the moment. */
7905 rtl_expr_nonnegative_p (r)
7908 switch (GET_CODE (r))
7911 return INTVAL (r) >= 0;
7914 if (GET_MODE (r) == VOIDmode)
7915 return CONST_DOUBLE_HIGH (r) >= 0;
7923 units = CONST_VECTOR_NUNITS (r);
7925 for (i = 0; i < units; ++i)
7927 elt = CONST_VECTOR_ELT (r, i);
7928 if (!rtl_expr_nonnegative_p (elt))
7937 /* These are always nonnegative. */
7945 #include "gt-fold-const.h"