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"
61 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
62 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
63 static bool negate_expr_p (tree);
64 static tree negate_expr (tree);
65 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
66 static tree associate_trees (tree, tree, enum tree_code, tree);
67 static tree int_const_binop (enum tree_code, tree, tree, int);
68 static tree const_binop (enum tree_code, tree, tree, int);
69 static hashval_t size_htab_hash (const void *);
70 static int size_htab_eq (const void *, const void *);
71 static tree fold_convert (tree, tree);
72 static enum tree_code invert_tree_comparison (enum tree_code);
73 static enum tree_code swap_tree_comparison (enum tree_code);
74 static int comparison_to_compcode (enum tree_code);
75 static enum tree_code compcode_to_comparison (int);
76 static int truth_value_p (enum tree_code);
77 static int operand_equal_for_comparison_p (tree, tree, tree);
78 static int twoval_comparison_p (tree, tree *, tree *, int *);
79 static tree eval_subst (tree, tree, tree, tree, tree);
80 static tree pedantic_omit_one_operand (tree, tree, tree);
81 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
82 static tree make_bit_field_ref (tree, tree, int, int, int);
83 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
84 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
85 enum machine_mode *, int *, int *,
87 static int all_ones_mask_p (tree, int);
88 static tree sign_bit_p (tree, tree);
89 static int simple_operand_p (tree);
90 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
91 static tree make_range (tree, int *, tree *, tree *);
92 static tree build_range_check (tree, tree, int, tree, tree);
93 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
95 static tree fold_range_test (tree);
96 static tree unextend (tree, int, int, tree);
97 static tree fold_truthop (enum tree_code, tree, tree, tree);
98 static tree optimize_minmax_comparison (tree);
99 static tree extract_muldiv (tree, tree, enum tree_code, tree);
100 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree);
101 static tree strip_compound_expr (tree, tree);
102 static int multiple_of_p (tree, tree, tree);
103 static tree constant_boolean_node (int, tree);
104 static int count_cond (tree, int);
105 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree, tree,
107 static bool fold_real_zero_addition_p (tree, tree, int);
108 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
110 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
112 /* The following constants represent a bit based encoding of GCC's
113 comparison operators. This encoding simplifies transformations
114 on relational comparison operators, such as AND and OR. */
115 #define COMPCODE_FALSE 0
116 #define COMPCODE_LT 1
117 #define COMPCODE_EQ 2
118 #define COMPCODE_LE 3
119 #define COMPCODE_GT 4
120 #define COMPCODE_NE 5
121 #define COMPCODE_GE 6
122 #define COMPCODE_TRUE 7
124 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
125 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
126 and SUM1. Then this yields nonzero if overflow occurred during the
129 Overflow occurs if A and B have the same sign, but A and SUM differ in
130 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
132 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
134 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
135 We do that by representing the two-word integer in 4 words, with only
136 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
137 number. The value of the word is LOWPART + HIGHPART * BASE. */
140 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
141 #define HIGHPART(x) \
142 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
143 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
145 /* Unpack a two-word integer into 4 words.
146 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
147 WORDS points to the array of HOST_WIDE_INTs. */
150 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
152 words[0] = LOWPART (low);
153 words[1] = HIGHPART (low);
154 words[2] = LOWPART (hi);
155 words[3] = HIGHPART (hi);
158 /* Pack an array of 4 words into a two-word integer.
159 WORDS points to the array of words.
160 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
163 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
166 *low = words[0] + words[1] * BASE;
167 *hi = words[2] + words[3] * BASE;
170 /* Make the integer constant T valid for its type by setting to 0 or 1 all
171 the bits in the constant that don't belong in the type.
173 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
174 nonzero, a signed overflow has already occurred in calculating T, so
178 force_fit_type (tree t, int overflow)
180 unsigned HOST_WIDE_INT low;
184 if (TREE_CODE (t) == REAL_CST)
186 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
187 Consider doing it via real_convert now. */
191 else if (TREE_CODE (t) != INTEGER_CST)
194 low = TREE_INT_CST_LOW (t);
195 high = TREE_INT_CST_HIGH (t);
197 if (POINTER_TYPE_P (TREE_TYPE (t))
198 || TREE_CODE (TREE_TYPE (t)) == OFFSET_TYPE)
201 prec = TYPE_PRECISION (TREE_TYPE (t));
203 /* First clear all bits that are beyond the type's precision. */
205 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
207 else if (prec > HOST_BITS_PER_WIDE_INT)
208 TREE_INT_CST_HIGH (t)
209 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
212 TREE_INT_CST_HIGH (t) = 0;
213 if (prec < HOST_BITS_PER_WIDE_INT)
214 TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
217 /* Unsigned types do not suffer sign extension or overflow unless they
219 if (TREE_UNSIGNED (TREE_TYPE (t))
220 && ! (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
221 && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
224 /* If the value's sign bit is set, extend the sign. */
225 if (prec != 2 * HOST_BITS_PER_WIDE_INT
226 && (prec > HOST_BITS_PER_WIDE_INT
227 ? 0 != (TREE_INT_CST_HIGH (t)
229 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
230 : 0 != (TREE_INT_CST_LOW (t)
231 & ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
233 /* Value is negative:
234 set to 1 all the bits that are outside this type's precision. */
235 if (prec > HOST_BITS_PER_WIDE_INT)
236 TREE_INT_CST_HIGH (t)
237 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
240 TREE_INT_CST_HIGH (t) = -1;
241 if (prec < HOST_BITS_PER_WIDE_INT)
242 TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
246 /* Return nonzero if signed overflow occurred. */
248 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
252 /* Add two doubleword integers with doubleword result.
253 Each argument is given as two `HOST_WIDE_INT' pieces.
254 One argument is L1 and H1; the other, L2 and H2.
255 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
258 add_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
259 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
260 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
262 unsigned HOST_WIDE_INT l;
266 h = h1 + h2 + (l < l1);
270 return OVERFLOW_SUM_SIGN (h1, h2, h);
273 /* Negate a doubleword integer with doubleword result.
274 Return nonzero if the operation overflows, assuming it's signed.
275 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
276 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
279 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
280 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
286 return (*hv & h1) < 0;
296 /* Multiply two doubleword integers with doubleword result.
297 Return nonzero if the operation overflows, assuming it's signed.
298 Each argument is given as two `HOST_WIDE_INT' pieces.
299 One argument is L1 and H1; the other, L2 and H2.
300 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
303 mul_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
304 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
305 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
307 HOST_WIDE_INT arg1[4];
308 HOST_WIDE_INT arg2[4];
309 HOST_WIDE_INT prod[4 * 2];
310 unsigned HOST_WIDE_INT carry;
312 unsigned HOST_WIDE_INT toplow, neglow;
313 HOST_WIDE_INT tophigh, neghigh;
315 encode (arg1, l1, h1);
316 encode (arg2, l2, h2);
318 memset (prod, 0, sizeof prod);
320 for (i = 0; i < 4; i++)
323 for (j = 0; j < 4; j++)
326 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
327 carry += arg1[i] * arg2[j];
328 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
330 prod[k] = LOWPART (carry);
331 carry = HIGHPART (carry);
336 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
338 /* Check for overflow by calculating the top half of the answer in full;
339 it should agree with the low half's sign bit. */
340 decode (prod + 4, &toplow, &tophigh);
343 neg_double (l2, h2, &neglow, &neghigh);
344 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
348 neg_double (l1, h1, &neglow, &neghigh);
349 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
351 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
354 /* Shift the doubleword integer in L1, H1 left by COUNT places
355 keeping only PREC bits of result.
356 Shift right if COUNT is negative.
357 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
358 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
361 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
362 HOST_WIDE_INT count, unsigned int prec,
363 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
365 unsigned HOST_WIDE_INT signmask;
369 rshift_double (l1, h1, -count, prec, lv, hv, arith);
373 #ifdef SHIFT_COUNT_TRUNCATED
374 if (SHIFT_COUNT_TRUNCATED)
378 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
380 /* Shifting by the host word size is undefined according to the
381 ANSI standard, so we must handle this as a special case. */
385 else if (count >= HOST_BITS_PER_WIDE_INT)
387 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
392 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
393 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
397 /* Sign extend all bits that are beyond the precision. */
399 signmask = -((prec > HOST_BITS_PER_WIDE_INT
400 ? ((unsigned HOST_WIDE_INT) *hv
401 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
402 : (*lv >> (prec - 1))) & 1);
404 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
406 else if (prec >= HOST_BITS_PER_WIDE_INT)
408 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
409 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
414 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
415 *lv |= signmask << prec;
419 /* Shift the doubleword integer in L1, H1 right by COUNT places
420 keeping only PREC bits of result. COUNT must be positive.
421 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
422 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
425 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
426 HOST_WIDE_INT count, unsigned int prec,
427 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
430 unsigned HOST_WIDE_INT signmask;
433 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
436 #ifdef SHIFT_COUNT_TRUNCATED
437 if (SHIFT_COUNT_TRUNCATED)
441 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
443 /* Shifting by the host word size is undefined according to the
444 ANSI standard, so we must handle this as a special case. */
448 else if (count >= HOST_BITS_PER_WIDE_INT)
451 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
455 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
457 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
460 /* Zero / sign extend all bits that are beyond the precision. */
462 if (count >= (HOST_WIDE_INT)prec)
467 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
469 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
471 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
472 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
477 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
478 *lv |= signmask << (prec - count);
482 /* Rotate the doubleword integer in L1, H1 left by COUNT places
483 keeping only PREC bits of result.
484 Rotate right if COUNT is negative.
485 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
488 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
489 HOST_WIDE_INT count, unsigned int prec,
490 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
492 unsigned HOST_WIDE_INT s1l, s2l;
493 HOST_WIDE_INT s1h, s2h;
499 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
500 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
505 /* Rotate the doubleword integer in L1, H1 left by COUNT places
506 keeping only PREC bits of result. COUNT must be positive.
507 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
510 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
511 HOST_WIDE_INT count, unsigned int prec,
512 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
514 unsigned HOST_WIDE_INT s1l, s2l;
515 HOST_WIDE_INT s1h, s2h;
521 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
522 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
527 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
528 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
529 CODE is a tree code for a kind of division, one of
530 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
532 It controls how the quotient is rounded to an integer.
533 Return nonzero if the operation overflows.
534 UNS nonzero says do unsigned division. */
537 div_and_round_double (enum tree_code code, int uns,
538 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
539 HOST_WIDE_INT hnum_orig,
540 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
541 HOST_WIDE_INT hden_orig,
542 unsigned HOST_WIDE_INT *lquo,
543 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
547 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
548 HOST_WIDE_INT den[4], quo[4];
550 unsigned HOST_WIDE_INT work;
551 unsigned HOST_WIDE_INT carry = 0;
552 unsigned HOST_WIDE_INT lnum = lnum_orig;
553 HOST_WIDE_INT hnum = hnum_orig;
554 unsigned HOST_WIDE_INT lden = lden_orig;
555 HOST_WIDE_INT hden = hden_orig;
558 if (hden == 0 && lden == 0)
559 overflow = 1, lden = 1;
561 /* calculate quotient sign and convert operands to unsigned. */
567 /* (minimum integer) / (-1) is the only overflow case. */
568 if (neg_double (lnum, hnum, &lnum, &hnum)
569 && ((HOST_WIDE_INT) lden & hden) == -1)
575 neg_double (lden, hden, &lden, &hden);
579 if (hnum == 0 && hden == 0)
580 { /* single precision */
582 /* This unsigned division rounds toward zero. */
588 { /* trivial case: dividend < divisor */
589 /* hden != 0 already checked. */
596 memset (quo, 0, sizeof quo);
598 memset (num, 0, sizeof num); /* to zero 9th element */
599 memset (den, 0, sizeof den);
601 encode (num, lnum, hnum);
602 encode (den, lden, hden);
604 /* Special code for when the divisor < BASE. */
605 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
607 /* hnum != 0 already checked. */
608 for (i = 4 - 1; i >= 0; i--)
610 work = num[i] + carry * BASE;
611 quo[i] = work / lden;
617 /* Full double precision division,
618 with thanks to Don Knuth's "Seminumerical Algorithms". */
619 int num_hi_sig, den_hi_sig;
620 unsigned HOST_WIDE_INT quo_est, scale;
622 /* Find the highest nonzero divisor digit. */
623 for (i = 4 - 1;; i--)
630 /* Insure that the first digit of the divisor is at least BASE/2.
631 This is required by the quotient digit estimation algorithm. */
633 scale = BASE / (den[den_hi_sig] + 1);
635 { /* scale divisor and dividend */
637 for (i = 0; i <= 4 - 1; i++)
639 work = (num[i] * scale) + carry;
640 num[i] = LOWPART (work);
641 carry = HIGHPART (work);
646 for (i = 0; i <= 4 - 1; i++)
648 work = (den[i] * scale) + carry;
649 den[i] = LOWPART (work);
650 carry = HIGHPART (work);
651 if (den[i] != 0) den_hi_sig = i;
658 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
660 /* Guess the next quotient digit, quo_est, by dividing the first
661 two remaining dividend digits by the high order quotient digit.
662 quo_est is never low and is at most 2 high. */
663 unsigned HOST_WIDE_INT tmp;
665 num_hi_sig = i + den_hi_sig + 1;
666 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
667 if (num[num_hi_sig] != den[den_hi_sig])
668 quo_est = work / den[den_hi_sig];
672 /* Refine quo_est so it's usually correct, and at most one high. */
673 tmp = work - quo_est * den[den_hi_sig];
675 && (den[den_hi_sig - 1] * quo_est
676 > (tmp * BASE + num[num_hi_sig - 2])))
679 /* Try QUO_EST as the quotient digit, by multiplying the
680 divisor by QUO_EST and subtracting from the remaining dividend.
681 Keep in mind that QUO_EST is the I - 1st digit. */
684 for (j = 0; j <= den_hi_sig; j++)
686 work = quo_est * den[j] + carry;
687 carry = HIGHPART (work);
688 work = num[i + j] - LOWPART (work);
689 num[i + j] = LOWPART (work);
690 carry += HIGHPART (work) != 0;
693 /* If quo_est was high by one, then num[i] went negative and
694 we need to correct things. */
695 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
698 carry = 0; /* add divisor back in */
699 for (j = 0; j <= den_hi_sig; j++)
701 work = num[i + j] + den[j] + carry;
702 carry = HIGHPART (work);
703 num[i + j] = LOWPART (work);
706 num [num_hi_sig] += carry;
709 /* Store the quotient digit. */
714 decode (quo, lquo, hquo);
717 /* If result is negative, make it so. */
719 neg_double (*lquo, *hquo, lquo, hquo);
721 /* compute trial remainder: rem = num - (quo * den) */
722 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
723 neg_double (*lrem, *hrem, lrem, hrem);
724 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
729 case TRUNC_MOD_EXPR: /* round toward zero */
730 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
734 case FLOOR_MOD_EXPR: /* round toward negative infinity */
735 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
738 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
746 case CEIL_MOD_EXPR: /* round toward positive infinity */
747 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
749 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
757 case ROUND_MOD_EXPR: /* round to closest integer */
759 unsigned HOST_WIDE_INT labs_rem = *lrem;
760 HOST_WIDE_INT habs_rem = *hrem;
761 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
762 HOST_WIDE_INT habs_den = hden, htwice;
764 /* Get absolute values. */
766 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
768 neg_double (lden, hden, &labs_den, &habs_den);
770 /* If (2 * abs (lrem) >= abs (lden)) */
771 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
772 labs_rem, habs_rem, <wice, &htwice);
774 if (((unsigned HOST_WIDE_INT) habs_den
775 < (unsigned HOST_WIDE_INT) htwice)
776 || (((unsigned HOST_WIDE_INT) habs_den
777 == (unsigned HOST_WIDE_INT) htwice)
778 && (labs_den < ltwice)))
782 add_double (*lquo, *hquo,
783 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
786 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
798 /* compute true remainder: rem = num - (quo * den) */
799 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
800 neg_double (*lrem, *hrem, lrem, hrem);
801 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
805 /* Determine whether an expression T can be cheaply negated using
806 the function negate_expr. */
809 negate_expr_p (tree t)
811 unsigned HOST_WIDE_INT val;
818 type = TREE_TYPE (t);
821 switch (TREE_CODE (t))
824 if (TREE_UNSIGNED (type))
827 /* Check that -CST will not overflow type. */
828 prec = TYPE_PRECISION (type);
829 if (prec > HOST_BITS_PER_WIDE_INT)
831 if (TREE_INT_CST_LOW (t) != 0)
833 prec -= HOST_BITS_PER_WIDE_INT;
834 val = TREE_INT_CST_HIGH (t);
837 val = TREE_INT_CST_LOW (t);
838 if (prec < HOST_BITS_PER_WIDE_INT)
839 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
840 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
853 /* Given T, an expression, return the negation of T. Allow for T to be
854 null, in which case return null. */
865 type = TREE_TYPE (t);
868 switch (TREE_CODE (t))
872 if (! TREE_UNSIGNED (type)
873 && 0 != (tem = fold (build1 (NEGATE_EXPR, type, t)))
874 && ! TREE_OVERFLOW (tem))
879 return convert (type, TREE_OPERAND (t, 0));
882 /* - (A - B) -> B - A */
883 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
884 return convert (type,
885 fold (build (MINUS_EXPR, TREE_TYPE (t),
887 TREE_OPERAND (t, 0))));
894 return convert (type, fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t)));
897 /* Split a tree IN into a constant, literal and variable parts that could be
898 combined with CODE to make IN. "constant" means an expression with
899 TREE_CONSTANT but that isn't an actual constant. CODE must be a
900 commutative arithmetic operation. Store the constant part into *CONP,
901 the literal in *LITP and return the variable part. If a part isn't
902 present, set it to null. If the tree does not decompose in this way,
903 return the entire tree as the variable part and the other parts as null.
905 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
906 case, we negate an operand that was subtracted. Except if it is a
907 literal for which we use *MINUS_LITP instead.
909 If NEGATE_P is true, we are negating all of IN, again except a literal
910 for which we use *MINUS_LITP instead.
912 If IN is itself a literal or constant, return it as appropriate.
914 Note that we do not guarantee that any of the three values will be the
915 same type as IN, but they will have the same signedness and mode. */
918 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
919 tree *minus_litp, int negate_p)
927 /* Strip any conversions that don't change the machine mode or signedness. */
928 STRIP_SIGN_NOPS (in);
930 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
932 else if (TREE_CODE (in) == code
933 || (! FLOAT_TYPE_P (TREE_TYPE (in))
934 /* We can associate addition and subtraction together (even
935 though the C standard doesn't say so) for integers because
936 the value is not affected. For reals, the value might be
937 affected, so we can't. */
938 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
939 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
941 tree op0 = TREE_OPERAND (in, 0);
942 tree op1 = TREE_OPERAND (in, 1);
943 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
944 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
946 /* First see if either of the operands is a literal, then a constant. */
947 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
948 *litp = op0, op0 = 0;
949 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
950 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
952 if (op0 != 0 && TREE_CONSTANT (op0))
953 *conp = op0, op0 = 0;
954 else if (op1 != 0 && TREE_CONSTANT (op1))
955 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
957 /* If we haven't dealt with either operand, this is not a case we can
958 decompose. Otherwise, VAR is either of the ones remaining, if any. */
959 if (op0 != 0 && op1 != 0)
964 var = op1, neg_var_p = neg1_p;
966 /* Now do any needed negations. */
968 *minus_litp = *litp, *litp = 0;
970 *conp = negate_expr (*conp);
972 var = negate_expr (var);
974 else if (TREE_CONSTANT (in))
982 *minus_litp = *litp, *litp = 0;
983 else if (*minus_litp)
984 *litp = *minus_litp, *minus_litp = 0;
985 *conp = negate_expr (*conp);
986 var = negate_expr (var);
992 /* Re-associate trees split by the above function. T1 and T2 are either
993 expressions to associate or null. Return the new expression, if any. If
994 we build an operation, do it in TYPE and with CODE. */
997 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1004 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1005 try to fold this since we will have infinite recursion. But do
1006 deal with any NEGATE_EXPRs. */
1007 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1008 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1010 if (code == PLUS_EXPR)
1012 if (TREE_CODE (t1) == NEGATE_EXPR)
1013 return build (MINUS_EXPR, type, convert (type, t2),
1014 convert (type, TREE_OPERAND (t1, 0)));
1015 else if (TREE_CODE (t2) == NEGATE_EXPR)
1016 return build (MINUS_EXPR, type, convert (type, t1),
1017 convert (type, TREE_OPERAND (t2, 0)));
1019 return build (code, type, convert (type, t1), convert (type, t2));
1022 return fold (build (code, type, convert (type, t1), convert (type, t2)));
1025 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1026 to produce a new constant.
1028 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1031 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1033 unsigned HOST_WIDE_INT int1l, int2l;
1034 HOST_WIDE_INT int1h, int2h;
1035 unsigned HOST_WIDE_INT low;
1037 unsigned HOST_WIDE_INT garbagel;
1038 HOST_WIDE_INT garbageh;
1040 tree type = TREE_TYPE (arg1);
1041 int uns = TREE_UNSIGNED (type);
1043 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1045 int no_overflow = 0;
1047 int1l = TREE_INT_CST_LOW (arg1);
1048 int1h = TREE_INT_CST_HIGH (arg1);
1049 int2l = TREE_INT_CST_LOW (arg2);
1050 int2h = TREE_INT_CST_HIGH (arg2);
1055 low = int1l | int2l, hi = int1h | int2h;
1059 low = int1l ^ int2l, hi = int1h ^ int2h;
1063 low = int1l & int2l, hi = int1h & int2h;
1066 case BIT_ANDTC_EXPR:
1067 low = int1l & ~int2l, hi = int1h & ~int2h;
1073 /* It's unclear from the C standard whether shifts can overflow.
1074 The following code ignores overflow; perhaps a C standard
1075 interpretation ruling is needed. */
1076 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1084 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1089 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1093 neg_double (int2l, int2h, &low, &hi);
1094 add_double (int1l, int1h, low, hi, &low, &hi);
1095 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1099 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1102 case TRUNC_DIV_EXPR:
1103 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1104 case EXACT_DIV_EXPR:
1105 /* This is a shortcut for a common special case. */
1106 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1107 && ! TREE_CONSTANT_OVERFLOW (arg1)
1108 && ! TREE_CONSTANT_OVERFLOW (arg2)
1109 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1111 if (code == CEIL_DIV_EXPR)
1114 low = int1l / int2l, hi = 0;
1118 /* ... fall through ... */
1120 case ROUND_DIV_EXPR:
1121 if (int2h == 0 && int2l == 1)
1123 low = int1l, hi = int1h;
1126 if (int1l == int2l && int1h == int2h
1127 && ! (int1l == 0 && int1h == 0))
1132 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1133 &low, &hi, &garbagel, &garbageh);
1136 case TRUNC_MOD_EXPR:
1137 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1138 /* This is a shortcut for a common special case. */
1139 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1140 && ! TREE_CONSTANT_OVERFLOW (arg1)
1141 && ! TREE_CONSTANT_OVERFLOW (arg2)
1142 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1144 if (code == CEIL_MOD_EXPR)
1146 low = int1l % int2l, hi = 0;
1150 /* ... fall through ... */
1152 case ROUND_MOD_EXPR:
1153 overflow = div_and_round_double (code, uns,
1154 int1l, int1h, int2l, int2h,
1155 &garbagel, &garbageh, &low, &hi);
1161 low = (((unsigned HOST_WIDE_INT) int1h
1162 < (unsigned HOST_WIDE_INT) int2h)
1163 || (((unsigned HOST_WIDE_INT) int1h
1164 == (unsigned HOST_WIDE_INT) int2h)
1167 low = (int1h < int2h
1168 || (int1h == int2h && int1l < int2l));
1170 if (low == (code == MIN_EXPR))
1171 low = int1l, hi = int1h;
1173 low = int2l, hi = int2h;
1180 /* If this is for a sizetype, can be represented as one (signed)
1181 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1184 && ((hi == 0 && (HOST_WIDE_INT) low >= 0)
1185 || (hi == -1 && (HOST_WIDE_INT) low < 0))
1186 && overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1187 return size_int_type_wide (low, type);
1190 t = build_int_2 (low, hi);
1191 TREE_TYPE (t) = TREE_TYPE (arg1);
1196 ? (!uns || is_sizetype) && overflow
1197 : (force_fit_type (t, (!uns || is_sizetype) && overflow)
1199 | TREE_OVERFLOW (arg1)
1200 | TREE_OVERFLOW (arg2));
1202 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1203 So check if force_fit_type truncated the value. */
1205 && ! TREE_OVERFLOW (t)
1206 && (TREE_INT_CST_HIGH (t) != hi
1207 || TREE_INT_CST_LOW (t) != low))
1208 TREE_OVERFLOW (t) = 1;
1210 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1211 | TREE_CONSTANT_OVERFLOW (arg1)
1212 | TREE_CONSTANT_OVERFLOW (arg2));
1216 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1217 constant. We assume ARG1 and ARG2 have the same data type, or at least
1218 are the same kind of constant and the same machine mode.
1220 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1223 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1228 if (TREE_CODE (arg1) == INTEGER_CST)
1229 return int_const_binop (code, arg1, arg2, notrunc);
1231 if (TREE_CODE (arg1) == REAL_CST)
1233 enum machine_mode mode;
1236 REAL_VALUE_TYPE value;
1239 d1 = TREE_REAL_CST (arg1);
1240 d2 = TREE_REAL_CST (arg2);
1242 type = TREE_TYPE (arg1);
1243 mode = TYPE_MODE (type);
1245 /* Don't perform operation if we honor signaling NaNs and
1246 either operand is a NaN. */
1247 if (HONOR_SNANS (mode)
1248 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1251 /* Don't perform operation if it would raise a division
1252 by zero exception. */
1253 if (code == RDIV_EXPR
1254 && REAL_VALUES_EQUAL (d2, dconst0)
1255 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1258 /* If either operand is a NaN, just return it. Otherwise, set up
1259 for floating-point trap; we return an overflow. */
1260 if (REAL_VALUE_ISNAN (d1))
1262 else if (REAL_VALUE_ISNAN (d2))
1265 REAL_ARITHMETIC (value, code, d1, d2);
1267 t = build_real (type, real_value_truncate (mode, value));
1270 = (force_fit_type (t, 0)
1271 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1272 TREE_CONSTANT_OVERFLOW (t)
1274 | TREE_CONSTANT_OVERFLOW (arg1)
1275 | TREE_CONSTANT_OVERFLOW (arg2);
1278 if (TREE_CODE (arg1) == COMPLEX_CST)
1280 tree type = TREE_TYPE (arg1);
1281 tree r1 = TREE_REALPART (arg1);
1282 tree i1 = TREE_IMAGPART (arg1);
1283 tree r2 = TREE_REALPART (arg2);
1284 tree i2 = TREE_IMAGPART (arg2);
1290 t = build_complex (type,
1291 const_binop (PLUS_EXPR, r1, r2, notrunc),
1292 const_binop (PLUS_EXPR, i1, i2, notrunc));
1296 t = build_complex (type,
1297 const_binop (MINUS_EXPR, r1, r2, notrunc),
1298 const_binop (MINUS_EXPR, i1, i2, notrunc));
1302 t = build_complex (type,
1303 const_binop (MINUS_EXPR,
1304 const_binop (MULT_EXPR,
1306 const_binop (MULT_EXPR,
1309 const_binop (PLUS_EXPR,
1310 const_binop (MULT_EXPR,
1312 const_binop (MULT_EXPR,
1320 = const_binop (PLUS_EXPR,
1321 const_binop (MULT_EXPR, r2, r2, notrunc),
1322 const_binop (MULT_EXPR, i2, i2, notrunc),
1325 t = build_complex (type,
1327 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1328 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1329 const_binop (PLUS_EXPR,
1330 const_binop (MULT_EXPR, r1, r2,
1332 const_binop (MULT_EXPR, i1, i2,
1335 magsquared, notrunc),
1337 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1338 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1339 const_binop (MINUS_EXPR,
1340 const_binop (MULT_EXPR, i1, r2,
1342 const_binop (MULT_EXPR, r1, i2,
1345 magsquared, notrunc));
1357 /* These are the hash table functions for the hash table of INTEGER_CST
1358 nodes of a sizetype. */
1360 /* Return the hash code code X, an INTEGER_CST. */
1363 size_htab_hash (const void *x)
1367 return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
1368 ^ htab_hash_pointer (TREE_TYPE (t))
1369 ^ (TREE_OVERFLOW (t) << 20));
1372 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1373 is the same as that given by *Y, which is the same. */
1376 size_htab_eq (const void *x, const void *y)
1381 return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
1382 && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt)
1383 && TREE_TYPE (xt) == TREE_TYPE (yt)
1384 && TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt));
1387 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1388 bits are given by NUMBER and of the sizetype represented by KIND. */
1391 size_int_wide (HOST_WIDE_INT number, enum size_type_kind kind)
1393 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1396 /* Likewise, but the desired type is specified explicitly. */
1398 static GTY (()) tree new_const;
1399 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
1403 size_int_type_wide (HOST_WIDE_INT number, tree type)
1409 size_htab = htab_create_ggc (1024, size_htab_hash, size_htab_eq, NULL);
1410 new_const = make_node (INTEGER_CST);
1413 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1414 hash table, we return the value from the hash table. Otherwise, we
1415 place that in the hash table and make a new node for the next time. */
1416 TREE_INT_CST_LOW (new_const) = number;
1417 TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0;
1418 TREE_TYPE (new_const) = type;
1419 TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const)
1420 = force_fit_type (new_const, 0);
1422 slot = htab_find_slot (size_htab, new_const, INSERT);
1428 new_const = make_node (INTEGER_CST);
1432 return (tree) *slot;
1435 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1436 is a tree code. The type of the result is taken from the operands.
1437 Both must be the same type integer type and it must be a size type.
1438 If the operands are constant, so is the result. */
1441 size_binop (enum tree_code code, tree arg0, tree arg1)
1443 tree type = TREE_TYPE (arg0);
1445 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1446 || type != TREE_TYPE (arg1))
1449 /* Handle the special case of two integer constants faster. */
1450 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1452 /* And some specific cases even faster than that. */
1453 if (code == PLUS_EXPR && integer_zerop (arg0))
1455 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1456 && integer_zerop (arg1))
1458 else if (code == MULT_EXPR && integer_onep (arg0))
1461 /* Handle general case of two integer constants. */
1462 return int_const_binop (code, arg0, arg1, 0);
1465 if (arg0 == error_mark_node || arg1 == error_mark_node)
1466 return error_mark_node;
1468 return fold (build (code, type, arg0, arg1));
1471 /* Given two values, either both of sizetype or both of bitsizetype,
1472 compute the difference between the two values. Return the value
1473 in signed type corresponding to the type of the operands. */
1476 size_diffop (tree arg0, tree arg1)
1478 tree type = TREE_TYPE (arg0);
1481 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1482 || type != TREE_TYPE (arg1))
1485 /* If the type is already signed, just do the simple thing. */
1486 if (! TREE_UNSIGNED (type))
1487 return size_binop (MINUS_EXPR, arg0, arg1);
1489 ctype = (type == bitsizetype || type == ubitsizetype
1490 ? sbitsizetype : ssizetype);
1492 /* If either operand is not a constant, do the conversions to the signed
1493 type and subtract. The hardware will do the right thing with any
1494 overflow in the subtraction. */
1495 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1496 return size_binop (MINUS_EXPR, convert (ctype, arg0),
1497 convert (ctype, arg1));
1499 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1500 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1501 overflow) and negate (which can't either). Special-case a result
1502 of zero while we're here. */
1503 if (tree_int_cst_equal (arg0, arg1))
1504 return convert (ctype, integer_zero_node);
1505 else if (tree_int_cst_lt (arg1, arg0))
1506 return convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1508 return size_binop (MINUS_EXPR, convert (ctype, integer_zero_node),
1509 convert (ctype, size_binop (MINUS_EXPR, arg1, arg0)));
1513 /* Given T, a tree representing type conversion of ARG1, a constant,
1514 return a constant tree representing the result of conversion. */
1517 fold_convert (tree t, tree arg1)
1519 tree type = TREE_TYPE (t);
1522 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1524 if (TREE_CODE (arg1) == INTEGER_CST)
1526 /* If we would build a constant wider than GCC supports,
1527 leave the conversion unfolded. */
1528 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1531 /* If we are trying to make a sizetype for a small integer, use
1532 size_int to pick up cached types to reduce duplicate nodes. */
1533 if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1534 && !TREE_CONSTANT_OVERFLOW (arg1)
1535 && compare_tree_int (arg1, 10000) < 0)
1536 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
1538 /* Given an integer constant, make new constant with new type,
1539 appropriately sign-extended or truncated. */
1540 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1541 TREE_INT_CST_HIGH (arg1));
1542 TREE_TYPE (t) = type;
1543 /* Indicate an overflow if (1) ARG1 already overflowed,
1544 or (2) force_fit_type indicates an overflow.
1545 Tell force_fit_type that an overflow has already occurred
1546 if ARG1 is a too-large unsigned value and T is signed.
1547 But don't indicate an overflow if converting a pointer. */
1549 = ((force_fit_type (t,
1550 (TREE_INT_CST_HIGH (arg1) < 0
1551 && (TREE_UNSIGNED (type)
1552 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
1553 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1554 || TREE_OVERFLOW (arg1));
1555 TREE_CONSTANT_OVERFLOW (t)
1556 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1558 else if (TREE_CODE (arg1) == REAL_CST)
1560 /* Don't initialize these, use assignments.
1561 Initialized local aggregates don't work on old compilers. */
1565 tree type1 = TREE_TYPE (arg1);
1568 x = TREE_REAL_CST (arg1);
1569 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
1571 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
1572 if (!no_upper_bound)
1573 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
1575 /* See if X will be in range after truncation towards 0.
1576 To compensate for truncation, move the bounds away from 0,
1577 but reject if X exactly equals the adjusted bounds. */
1578 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
1579 if (!no_upper_bound)
1580 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
1581 /* If X is a NaN, use zero instead and show we have an overflow.
1582 Otherwise, range check. */
1583 if (REAL_VALUE_ISNAN (x))
1584 overflow = 1, x = dconst0;
1585 else if (! (REAL_VALUES_LESS (l, x)
1587 && REAL_VALUES_LESS (x, u)))
1591 HOST_WIDE_INT low, high;
1592 REAL_VALUE_TO_INT (&low, &high, x);
1593 t = build_int_2 (low, high);
1595 TREE_TYPE (t) = type;
1597 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1598 TREE_CONSTANT_OVERFLOW (t)
1599 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1601 TREE_TYPE (t) = type;
1603 else if (TREE_CODE (type) == REAL_TYPE)
1605 if (TREE_CODE (arg1) == INTEGER_CST)
1606 return build_real_from_int_cst (type, arg1);
1607 if (TREE_CODE (arg1) == REAL_CST)
1609 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1611 /* We make a copy of ARG1 so that we don't modify an
1612 existing constant tree. */
1613 t = copy_node (arg1);
1614 TREE_TYPE (t) = type;
1618 t = build_real (type,
1619 real_value_truncate (TYPE_MODE (type),
1620 TREE_REAL_CST (arg1)));
1623 = TREE_OVERFLOW (arg1) | force_fit_type (t, 0);
1624 TREE_CONSTANT_OVERFLOW (t)
1625 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1629 TREE_CONSTANT (t) = 1;
1633 /* Return an expr equal to X but certainly not valid as an lvalue. */
1640 /* These things are certainly not lvalues. */
1641 if (TREE_CODE (x) == NON_LVALUE_EXPR
1642 || TREE_CODE (x) == INTEGER_CST
1643 || TREE_CODE (x) == REAL_CST
1644 || TREE_CODE (x) == STRING_CST
1645 || TREE_CODE (x) == ADDR_EXPR)
1648 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
1649 TREE_CONSTANT (result) = TREE_CONSTANT (x);
1653 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1654 Zero means allow extended lvalues. */
1656 int pedantic_lvalues;
1658 /* When pedantic, return an expr equal to X but certainly not valid as a
1659 pedantic lvalue. Otherwise, return X. */
1662 pedantic_non_lvalue (tree x)
1664 if (pedantic_lvalues)
1665 return non_lvalue (x);
1670 /* Given a tree comparison code, return the code that is the logical inverse
1671 of the given code. It is not safe to do this for floating-point
1672 comparisons, except for NE_EXPR and EQ_EXPR. */
1674 static enum tree_code
1675 invert_tree_comparison (enum tree_code code)
1696 /* Similar, but return the comparison that results if the operands are
1697 swapped. This is safe for floating-point. */
1699 static enum tree_code
1700 swap_tree_comparison (enum tree_code code)
1721 /* Convert a comparison tree code from an enum tree_code representation
1722 into a compcode bit-based encoding. This function is the inverse of
1723 compcode_to_comparison. */
1726 comparison_to_compcode (enum tree_code code)
1747 /* Convert a compcode bit-based encoding of a comparison operator back
1748 to GCC's enum tree_code representation. This function is the
1749 inverse of comparison_to_compcode. */
1751 static enum tree_code
1752 compcode_to_comparison (int code)
1773 /* Return nonzero if CODE is a tree code that represents a truth value. */
1776 truth_value_p (enum tree_code code)
1778 return (TREE_CODE_CLASS (code) == '<'
1779 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
1780 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
1781 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
1784 /* Return nonzero if two operands are necessarily equal.
1785 If ONLY_CONST is nonzero, only return nonzero for constants.
1786 This function tests whether the operands are indistinguishable;
1787 it does not test whether they are equal using C's == operation.
1788 The distinction is important for IEEE floating point, because
1789 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
1790 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
1793 operand_equal_p (tree arg0, tree arg1, int only_const)
1795 /* If both types don't have the same signedness, then we can't consider
1796 them equal. We must check this before the STRIP_NOPS calls
1797 because they may change the signedness of the arguments. */
1798 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
1804 if (TREE_CODE (arg0) != TREE_CODE (arg1)
1805 /* This is needed for conversions and for COMPONENT_REF.
1806 Might as well play it safe and always test this. */
1807 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
1808 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
1809 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
1812 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
1813 We don't care about side effects in that case because the SAVE_EXPR
1814 takes care of that for us. In all other cases, two expressions are
1815 equal if they have no side effects. If we have two identical
1816 expressions with side effects that should be treated the same due
1817 to the only side effects being identical SAVE_EXPR's, that will
1818 be detected in the recursive calls below. */
1819 if (arg0 == arg1 && ! only_const
1820 && (TREE_CODE (arg0) == SAVE_EXPR
1821 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
1824 /* Next handle constant cases, those for which we can return 1 even
1825 if ONLY_CONST is set. */
1826 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
1827 switch (TREE_CODE (arg0))
1830 return (! TREE_CONSTANT_OVERFLOW (arg0)
1831 && ! TREE_CONSTANT_OVERFLOW (arg1)
1832 && tree_int_cst_equal (arg0, arg1));
1835 return (! TREE_CONSTANT_OVERFLOW (arg0)
1836 && ! TREE_CONSTANT_OVERFLOW (arg1)
1837 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
1838 TREE_REAL_CST (arg1)));
1844 if (TREE_CONSTANT_OVERFLOW (arg0)
1845 || TREE_CONSTANT_OVERFLOW (arg1))
1848 v1 = TREE_VECTOR_CST_ELTS (arg0);
1849 v2 = TREE_VECTOR_CST_ELTS (arg1);
1852 if (!operand_equal_p (v1, v2, only_const))
1854 v1 = TREE_CHAIN (v1);
1855 v2 = TREE_CHAIN (v2);
1862 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
1864 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
1868 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
1869 && ! memcmp (TREE_STRING_POINTER (arg0),
1870 TREE_STRING_POINTER (arg1),
1871 TREE_STRING_LENGTH (arg0)));
1874 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
1883 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
1886 /* Two conversions are equal only if signedness and modes match. */
1887 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
1888 && (TREE_UNSIGNED (TREE_TYPE (arg0))
1889 != TREE_UNSIGNED (TREE_TYPE (arg1))))
1892 return operand_equal_p (TREE_OPERAND (arg0, 0),
1893 TREE_OPERAND (arg1, 0), 0);
1897 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
1898 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
1902 /* For commutative ops, allow the other order. */
1903 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
1904 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
1905 || TREE_CODE (arg0) == BIT_IOR_EXPR
1906 || TREE_CODE (arg0) == BIT_XOR_EXPR
1907 || TREE_CODE (arg0) == BIT_AND_EXPR
1908 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
1909 && operand_equal_p (TREE_OPERAND (arg0, 0),
1910 TREE_OPERAND (arg1, 1), 0)
1911 && operand_equal_p (TREE_OPERAND (arg0, 1),
1912 TREE_OPERAND (arg1, 0), 0));
1915 /* If either of the pointer (or reference) expressions we are
1916 dereferencing contain a side effect, these cannot be equal. */
1917 if (TREE_SIDE_EFFECTS (arg0)
1918 || TREE_SIDE_EFFECTS (arg1))
1921 switch (TREE_CODE (arg0))
1924 return operand_equal_p (TREE_OPERAND (arg0, 0),
1925 TREE_OPERAND (arg1, 0), 0);
1929 case ARRAY_RANGE_REF:
1930 return (operand_equal_p (TREE_OPERAND (arg0, 0),
1931 TREE_OPERAND (arg1, 0), 0)
1932 && operand_equal_p (TREE_OPERAND (arg0, 1),
1933 TREE_OPERAND (arg1, 1), 0));
1936 return (operand_equal_p (TREE_OPERAND (arg0, 0),
1937 TREE_OPERAND (arg1, 0), 0)
1938 && operand_equal_p (TREE_OPERAND (arg0, 1),
1939 TREE_OPERAND (arg1, 1), 0)
1940 && operand_equal_p (TREE_OPERAND (arg0, 2),
1941 TREE_OPERAND (arg1, 2), 0));
1947 switch (TREE_CODE (arg0))
1950 case TRUTH_NOT_EXPR:
1951 return operand_equal_p (TREE_OPERAND (arg0, 0),
1952 TREE_OPERAND (arg1, 0), 0);
1955 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
1958 /* If the CALL_EXPRs call different functions, then they
1959 clearly can not be equal. */
1960 if (! operand_equal_p (TREE_OPERAND (arg0, 0),
1961 TREE_OPERAND (arg1, 0), 0))
1964 /* Only consider const functions equivalent. */
1965 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == ADDR_EXPR)
1967 tree fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
1968 if (! (flags_from_decl_or_type (fndecl) & ECF_CONST))
1974 /* Now see if all the arguments are the same. operand_equal_p
1975 does not handle TREE_LIST, so we walk the operands here
1976 feeding them to operand_equal_p. */
1977 arg0 = TREE_OPERAND (arg0, 1);
1978 arg1 = TREE_OPERAND (arg1, 1);
1979 while (arg0 && arg1)
1981 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1), 0))
1984 arg0 = TREE_CHAIN (arg0);
1985 arg1 = TREE_CHAIN (arg1);
1988 /* If we get here and both argument lists are exhausted
1989 then the CALL_EXPRs are equal. */
1990 return ! (arg0 || arg1);
1997 /* Consider __builtin_sqrt equal to sqrt. */
1998 return TREE_CODE (arg0) == FUNCTION_DECL
1999 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2000 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2001 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1);
2008 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2009 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2011 When in doubt, return 0. */
2014 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2016 int unsignedp1, unsignedpo;
2017 tree primarg0, primarg1, primother;
2018 unsigned int correct_width;
2020 if (operand_equal_p (arg0, arg1, 0))
2023 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2024 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2027 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2028 and see if the inner values are the same. This removes any
2029 signedness comparison, which doesn't matter here. */
2030 primarg0 = arg0, primarg1 = arg1;
2031 STRIP_NOPS (primarg0);
2032 STRIP_NOPS (primarg1);
2033 if (operand_equal_p (primarg0, primarg1, 0))
2036 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2037 actual comparison operand, ARG0.
2039 First throw away any conversions to wider types
2040 already present in the operands. */
2042 primarg1 = get_narrower (arg1, &unsignedp1);
2043 primother = get_narrower (other, &unsignedpo);
2045 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2046 if (unsignedp1 == unsignedpo
2047 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2048 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2050 tree type = TREE_TYPE (arg0);
2052 /* Make sure shorter operand is extended the right way
2053 to match the longer operand. */
2054 primarg1 = convert ((*lang_hooks.types.signed_or_unsigned_type)
2055 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2057 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2064 /* See if ARG is an expression that is either a comparison or is performing
2065 arithmetic on comparisons. The comparisons must only be comparing
2066 two different values, which will be stored in *CVAL1 and *CVAL2; if
2067 they are nonzero it means that some operands have already been found.
2068 No variables may be used anywhere else in the expression except in the
2069 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2070 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2072 If this is true, return 1. Otherwise, return zero. */
2075 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2077 enum tree_code code = TREE_CODE (arg);
2078 char class = TREE_CODE_CLASS (code);
2080 /* We can handle some of the 'e' cases here. */
2081 if (class == 'e' && code == TRUTH_NOT_EXPR)
2083 else if (class == 'e'
2084 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2085 || code == COMPOUND_EXPR))
2088 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2089 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2091 /* If we've already found a CVAL1 or CVAL2, this expression is
2092 two complex to handle. */
2093 if (*cval1 || *cval2)
2103 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2106 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2107 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2108 cval1, cval2, save_p));
2114 if (code == COND_EXPR)
2115 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2116 cval1, cval2, save_p)
2117 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2118 cval1, cval2, save_p)
2119 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2120 cval1, cval2, save_p));
2124 /* First see if we can handle the first operand, then the second. For
2125 the second operand, we know *CVAL1 can't be zero. It must be that
2126 one side of the comparison is each of the values; test for the
2127 case where this isn't true by failing if the two operands
2130 if (operand_equal_p (TREE_OPERAND (arg, 0),
2131 TREE_OPERAND (arg, 1), 0))
2135 *cval1 = TREE_OPERAND (arg, 0);
2136 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2138 else if (*cval2 == 0)
2139 *cval2 = TREE_OPERAND (arg, 0);
2140 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2145 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2147 else if (*cval2 == 0)
2148 *cval2 = TREE_OPERAND (arg, 1);
2149 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2161 /* ARG is a tree that is known to contain just arithmetic operations and
2162 comparisons. Evaluate the operations in the tree substituting NEW0 for
2163 any occurrence of OLD0 as an operand of a comparison and likewise for
2167 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2169 tree type = TREE_TYPE (arg);
2170 enum tree_code code = TREE_CODE (arg);
2171 char class = TREE_CODE_CLASS (code);
2173 /* We can handle some of the 'e' cases here. */
2174 if (class == 'e' && code == TRUTH_NOT_EXPR)
2176 else if (class == 'e'
2177 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2183 return fold (build1 (code, type,
2184 eval_subst (TREE_OPERAND (arg, 0),
2185 old0, new0, old1, new1)));
2188 return fold (build (code, type,
2189 eval_subst (TREE_OPERAND (arg, 0),
2190 old0, new0, old1, new1),
2191 eval_subst (TREE_OPERAND (arg, 1),
2192 old0, new0, old1, new1)));
2198 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2201 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2204 return fold (build (code, type,
2205 eval_subst (TREE_OPERAND (arg, 0),
2206 old0, new0, old1, new1),
2207 eval_subst (TREE_OPERAND (arg, 1),
2208 old0, new0, old1, new1),
2209 eval_subst (TREE_OPERAND (arg, 2),
2210 old0, new0, old1, new1)));
2214 /* Fall through - ??? */
2218 tree arg0 = TREE_OPERAND (arg, 0);
2219 tree arg1 = TREE_OPERAND (arg, 1);
2221 /* We need to check both for exact equality and tree equality. The
2222 former will be true if the operand has a side-effect. In that
2223 case, we know the operand occurred exactly once. */
2225 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2227 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2230 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2232 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2235 return fold (build (code, type, arg0, arg1));
2243 /* Return a tree for the case when the result of an expression is RESULT
2244 converted to TYPE and OMITTED was previously an operand of the expression
2245 but is now not needed (e.g., we folded OMITTED * 0).
2247 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2248 the conversion of RESULT to TYPE. */
2251 omit_one_operand (tree type, tree result, tree omitted)
2253 tree t = convert (type, result);
2255 if (TREE_SIDE_EFFECTS (omitted))
2256 return build (COMPOUND_EXPR, type, omitted, t);
2258 return non_lvalue (t);
2261 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2264 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2266 tree t = convert (type, result);
2268 if (TREE_SIDE_EFFECTS (omitted))
2269 return build (COMPOUND_EXPR, type, omitted, t);
2271 return pedantic_non_lvalue (t);
2274 /* Return a simplified tree node for the truth-negation of ARG. This
2275 never alters ARG itself. We assume that ARG is an operation that
2276 returns a truth value (0 or 1). */
2279 invert_truthvalue (tree arg)
2281 tree type = TREE_TYPE (arg);
2282 enum tree_code code = TREE_CODE (arg);
2284 if (code == ERROR_MARK)
2287 /* If this is a comparison, we can simply invert it, except for
2288 floating-point non-equality comparisons, in which case we just
2289 enclose a TRUTH_NOT_EXPR around what we have. */
2291 if (TREE_CODE_CLASS (code) == '<')
2293 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2294 && !flag_unsafe_math_optimizations
2297 return build1 (TRUTH_NOT_EXPR, type, arg);
2299 return build (invert_tree_comparison (code), type,
2300 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2306 return convert (type, build_int_2 (integer_zerop (arg), 0));
2308 case TRUTH_AND_EXPR:
2309 return build (TRUTH_OR_EXPR, type,
2310 invert_truthvalue (TREE_OPERAND (arg, 0)),
2311 invert_truthvalue (TREE_OPERAND (arg, 1)));
2314 return build (TRUTH_AND_EXPR, type,
2315 invert_truthvalue (TREE_OPERAND (arg, 0)),
2316 invert_truthvalue (TREE_OPERAND (arg, 1)));
2318 case TRUTH_XOR_EXPR:
2319 /* Here we can invert either operand. We invert the first operand
2320 unless the second operand is a TRUTH_NOT_EXPR in which case our
2321 result is the XOR of the first operand with the inside of the
2322 negation of the second operand. */
2324 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2325 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2326 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2328 return build (TRUTH_XOR_EXPR, type,
2329 invert_truthvalue (TREE_OPERAND (arg, 0)),
2330 TREE_OPERAND (arg, 1));
2332 case TRUTH_ANDIF_EXPR:
2333 return build (TRUTH_ORIF_EXPR, type,
2334 invert_truthvalue (TREE_OPERAND (arg, 0)),
2335 invert_truthvalue (TREE_OPERAND (arg, 1)));
2337 case TRUTH_ORIF_EXPR:
2338 return build (TRUTH_ANDIF_EXPR, type,
2339 invert_truthvalue (TREE_OPERAND (arg, 0)),
2340 invert_truthvalue (TREE_OPERAND (arg, 1)));
2342 case TRUTH_NOT_EXPR:
2343 return TREE_OPERAND (arg, 0);
2346 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2347 invert_truthvalue (TREE_OPERAND (arg, 1)),
2348 invert_truthvalue (TREE_OPERAND (arg, 2)));
2351 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2352 invert_truthvalue (TREE_OPERAND (arg, 1)));
2354 case WITH_RECORD_EXPR:
2355 return build (WITH_RECORD_EXPR, type,
2356 invert_truthvalue (TREE_OPERAND (arg, 0)),
2357 TREE_OPERAND (arg, 1));
2359 case NON_LVALUE_EXPR:
2360 return invert_truthvalue (TREE_OPERAND (arg, 0));
2365 return build1 (TREE_CODE (arg), type,
2366 invert_truthvalue (TREE_OPERAND (arg, 0)));
2369 if (!integer_onep (TREE_OPERAND (arg, 1)))
2371 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2374 return build1 (TRUTH_NOT_EXPR, type, arg);
2376 case CLEANUP_POINT_EXPR:
2377 return build1 (CLEANUP_POINT_EXPR, type,
2378 invert_truthvalue (TREE_OPERAND (arg, 0)));
2383 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2385 return build1 (TRUTH_NOT_EXPR, type, arg);
2388 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2389 operands are another bit-wise operation with a common input. If so,
2390 distribute the bit operations to save an operation and possibly two if
2391 constants are involved. For example, convert
2392 (A | B) & (A | C) into A | (B & C)
2393 Further simplification will occur if B and C are constants.
2395 If this optimization cannot be done, 0 will be returned. */
2398 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
2403 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2404 || TREE_CODE (arg0) == code
2405 || (TREE_CODE (arg0) != BIT_AND_EXPR
2406 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2409 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2411 common = TREE_OPERAND (arg0, 0);
2412 left = TREE_OPERAND (arg0, 1);
2413 right = TREE_OPERAND (arg1, 1);
2415 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2417 common = TREE_OPERAND (arg0, 0);
2418 left = TREE_OPERAND (arg0, 1);
2419 right = TREE_OPERAND (arg1, 0);
2421 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2423 common = TREE_OPERAND (arg0, 1);
2424 left = TREE_OPERAND (arg0, 0);
2425 right = TREE_OPERAND (arg1, 1);
2427 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2429 common = TREE_OPERAND (arg0, 1);
2430 left = TREE_OPERAND (arg0, 0);
2431 right = TREE_OPERAND (arg1, 0);
2436 return fold (build (TREE_CODE (arg0), type, common,
2437 fold (build (code, type, left, right))));
2440 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2441 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2444 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
2447 tree result = build (BIT_FIELD_REF, type, inner,
2448 size_int (bitsize), bitsize_int (bitpos));
2450 TREE_UNSIGNED (result) = unsignedp;
2455 /* Optimize a bit-field compare.
2457 There are two cases: First is a compare against a constant and the
2458 second is a comparison of two items where the fields are at the same
2459 bit position relative to the start of a chunk (byte, halfword, word)
2460 large enough to contain it. In these cases we can avoid the shift
2461 implicit in bitfield extractions.
2463 For constants, we emit a compare of the shifted constant with the
2464 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2465 compared. For two fields at the same position, we do the ANDs with the
2466 similar mask and compare the result of the ANDs.
2468 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2469 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2470 are the left and right operands of the comparison, respectively.
2472 If the optimization described above can be done, we return the resulting
2473 tree. Otherwise we return zero. */
2476 optimize_bit_field_compare (enum tree_code code, tree compare_type,
2479 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2480 tree type = TREE_TYPE (lhs);
2481 tree signed_type, unsigned_type;
2482 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2483 enum machine_mode lmode, rmode, nmode;
2484 int lunsignedp, runsignedp;
2485 int lvolatilep = 0, rvolatilep = 0;
2486 tree linner, rinner = NULL_TREE;
2490 /* Get all the information about the extractions being done. If the bit size
2491 if the same as the size of the underlying object, we aren't doing an
2492 extraction at all and so can do nothing. We also don't want to
2493 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2494 then will no longer be able to replace it. */
2495 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2496 &lunsignedp, &lvolatilep);
2497 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2498 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2503 /* If this is not a constant, we can only do something if bit positions,
2504 sizes, and signedness are the same. */
2505 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2506 &runsignedp, &rvolatilep);
2508 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2509 || lunsignedp != runsignedp || offset != 0
2510 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2514 /* See if we can find a mode to refer to this field. We should be able to,
2515 but fail if we can't. */
2516 nmode = get_best_mode (lbitsize, lbitpos,
2517 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2518 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2519 TYPE_ALIGN (TREE_TYPE (rinner))),
2520 word_mode, lvolatilep || rvolatilep);
2521 if (nmode == VOIDmode)
2524 /* Set signed and unsigned types of the precision of this mode for the
2526 signed_type = (*lang_hooks.types.type_for_mode) (nmode, 0);
2527 unsigned_type = (*lang_hooks.types.type_for_mode) (nmode, 1);
2529 /* Compute the bit position and size for the new reference and our offset
2530 within it. If the new reference is the same size as the original, we
2531 won't optimize anything, so return zero. */
2532 nbitsize = GET_MODE_BITSIZE (nmode);
2533 nbitpos = lbitpos & ~ (nbitsize - 1);
2535 if (nbitsize == lbitsize)
2538 if (BYTES_BIG_ENDIAN)
2539 lbitpos = nbitsize - lbitsize - lbitpos;
2541 /* Make the mask to be used against the extracted field. */
2542 mask = build_int_2 (~0, ~0);
2543 TREE_TYPE (mask) = unsigned_type;
2544 force_fit_type (mask, 0);
2545 mask = convert (unsigned_type, mask);
2546 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2547 mask = const_binop (RSHIFT_EXPR, mask,
2548 size_int (nbitsize - lbitsize - lbitpos), 0);
2551 /* If not comparing with constant, just rework the comparison
2553 return build (code, compare_type,
2554 build (BIT_AND_EXPR, unsigned_type,
2555 make_bit_field_ref (linner, unsigned_type,
2556 nbitsize, nbitpos, 1),
2558 build (BIT_AND_EXPR, unsigned_type,
2559 make_bit_field_ref (rinner, unsigned_type,
2560 nbitsize, nbitpos, 1),
2563 /* Otherwise, we are handling the constant case. See if the constant is too
2564 big for the field. Warn and return a tree of for 0 (false) if so. We do
2565 this not only for its own sake, but to avoid having to test for this
2566 error case below. If we didn't, we might generate wrong code.
2568 For unsigned fields, the constant shifted right by the field length should
2569 be all zero. For signed fields, the high-order bits should agree with
2574 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2575 convert (unsigned_type, rhs),
2576 size_int (lbitsize), 0)))
2578 warning ("comparison is always %d due to width of bit-field",
2580 return convert (compare_type,
2582 ? integer_one_node : integer_zero_node));
2587 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
2588 size_int (lbitsize - 1), 0);
2589 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2591 warning ("comparison is always %d due to width of bit-field",
2593 return convert (compare_type,
2595 ? integer_one_node : integer_zero_node));
2599 /* Single-bit compares should always be against zero. */
2600 if (lbitsize == 1 && ! integer_zerop (rhs))
2602 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2603 rhs = convert (type, integer_zero_node);
2606 /* Make a new bitfield reference, shift the constant over the
2607 appropriate number of bits and mask it with the computed mask
2608 (in case this was a signed field). If we changed it, make a new one. */
2609 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
2612 TREE_SIDE_EFFECTS (lhs) = 1;
2613 TREE_THIS_VOLATILE (lhs) = 1;
2616 rhs = fold (const_binop (BIT_AND_EXPR,
2617 const_binop (LSHIFT_EXPR,
2618 convert (unsigned_type, rhs),
2619 size_int (lbitpos), 0),
2622 return build (code, compare_type,
2623 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2627 /* Subroutine for fold_truthop: decode a field reference.
2629 If EXP is a comparison reference, we return the innermost reference.
2631 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2632 set to the starting bit number.
2634 If the innermost field can be completely contained in a mode-sized
2635 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2637 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2638 otherwise it is not changed.
2640 *PUNSIGNEDP is set to the signedness of the field.
2642 *PMASK is set to the mask used. This is either contained in a
2643 BIT_AND_EXPR or derived from the width of the field.
2645 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2647 Return 0 if this is not a component reference or is one that we can't
2648 do anything with. */
2651 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
2652 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
2653 int *punsignedp, int *pvolatilep,
2654 tree *pmask, tree *pand_mask)
2656 tree outer_type = 0;
2658 tree mask, inner, offset;
2660 unsigned int precision;
2662 /* All the optimizations using this function assume integer fields.
2663 There are problems with FP fields since the type_for_size call
2664 below can fail for, e.g., XFmode. */
2665 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
2668 /* We are interested in the bare arrangement of bits, so strip everything
2669 that doesn't affect the machine mode. However, record the type of the
2670 outermost expression if it may matter below. */
2671 if (TREE_CODE (exp) == NOP_EXPR
2672 || TREE_CODE (exp) == CONVERT_EXPR
2673 || TREE_CODE (exp) == NON_LVALUE_EXPR)
2674 outer_type = TREE_TYPE (exp);
2677 if (TREE_CODE (exp) == BIT_AND_EXPR)
2679 and_mask = TREE_OPERAND (exp, 1);
2680 exp = TREE_OPERAND (exp, 0);
2681 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
2682 if (TREE_CODE (and_mask) != INTEGER_CST)
2686 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
2687 punsignedp, pvolatilep);
2688 if ((inner == exp && and_mask == 0)
2689 || *pbitsize < 0 || offset != 0
2690 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
2693 /* If the number of bits in the reference is the same as the bitsize of
2694 the outer type, then the outer type gives the signedness. Otherwise
2695 (in case of a small bitfield) the signedness is unchanged. */
2696 if (outer_type && *pbitsize == tree_low_cst (TYPE_SIZE (outer_type), 1))
2697 *punsignedp = TREE_UNSIGNED (outer_type);
2699 /* Compute the mask to access the bitfield. */
2700 unsigned_type = (*lang_hooks.types.type_for_size) (*pbitsize, 1);
2701 precision = TYPE_PRECISION (unsigned_type);
2703 mask = build_int_2 (~0, ~0);
2704 TREE_TYPE (mask) = unsigned_type;
2705 force_fit_type (mask, 0);
2706 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2707 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2709 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
2711 mask = fold (build (BIT_AND_EXPR, unsigned_type,
2712 convert (unsigned_type, and_mask), mask));
2715 *pand_mask = and_mask;
2719 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
2723 all_ones_mask_p (tree mask, int size)
2725 tree type = TREE_TYPE (mask);
2726 unsigned int precision = TYPE_PRECISION (type);
2729 tmask = build_int_2 (~0, ~0);
2730 TREE_TYPE (tmask) = (*lang_hooks.types.signed_type) (type);
2731 force_fit_type (tmask, 0);
2733 tree_int_cst_equal (mask,
2734 const_binop (RSHIFT_EXPR,
2735 const_binop (LSHIFT_EXPR, tmask,
2736 size_int (precision - size),
2738 size_int (precision - size), 0));
2741 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
2742 represents the sign bit of EXP's type. If EXP represents a sign
2743 or zero extension, also test VAL against the unextended type.
2744 The return value is the (sub)expression whose sign bit is VAL,
2745 or NULL_TREE otherwise. */
2748 sign_bit_p (tree exp, tree val)
2750 unsigned HOST_WIDE_INT mask_lo, lo;
2751 HOST_WIDE_INT mask_hi, hi;
2755 /* Tree EXP must have an integral type. */
2756 t = TREE_TYPE (exp);
2757 if (! INTEGRAL_TYPE_P (t))
2760 /* Tree VAL must be an integer constant. */
2761 if (TREE_CODE (val) != INTEGER_CST
2762 || TREE_CONSTANT_OVERFLOW (val))
2765 width = TYPE_PRECISION (t);
2766 if (width > HOST_BITS_PER_WIDE_INT)
2768 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
2771 mask_hi = ((unsigned HOST_WIDE_INT) -1
2772 >> (2 * HOST_BITS_PER_WIDE_INT - width));
2778 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
2781 mask_lo = ((unsigned HOST_WIDE_INT) -1
2782 >> (HOST_BITS_PER_WIDE_INT - width));
2785 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
2786 treat VAL as if it were unsigned. */
2787 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
2788 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
2791 /* Handle extension from a narrower type. */
2792 if (TREE_CODE (exp) == NOP_EXPR
2793 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
2794 return sign_bit_p (TREE_OPERAND (exp, 0), val);
2799 /* Subroutine for fold_truthop: determine if an operand is simple enough
2800 to be evaluated unconditionally. */
2803 simple_operand_p (tree exp)
2805 /* Strip any conversions that don't change the machine mode. */
2806 while ((TREE_CODE (exp) == NOP_EXPR
2807 || TREE_CODE (exp) == CONVERT_EXPR)
2808 && (TYPE_MODE (TREE_TYPE (exp))
2809 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
2810 exp = TREE_OPERAND (exp, 0);
2812 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
2814 && ! TREE_ADDRESSABLE (exp)
2815 && ! TREE_THIS_VOLATILE (exp)
2816 && ! DECL_NONLOCAL (exp)
2817 /* Don't regard global variables as simple. They may be
2818 allocated in ways unknown to the compiler (shared memory,
2819 #pragma weak, etc). */
2820 && ! TREE_PUBLIC (exp)
2821 && ! DECL_EXTERNAL (exp)
2822 /* Loading a static variable is unduly expensive, but global
2823 registers aren't expensive. */
2824 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
2827 /* The following functions are subroutines to fold_range_test and allow it to
2828 try to change a logical combination of comparisons into a range test.
2831 X == 2 || X == 3 || X == 4 || X == 5
2835 (unsigned) (X - 2) <= 3
2837 We describe each set of comparisons as being either inside or outside
2838 a range, using a variable named like IN_P, and then describe the
2839 range with a lower and upper bound. If one of the bounds is omitted,
2840 it represents either the highest or lowest value of the type.
2842 In the comments below, we represent a range by two numbers in brackets
2843 preceded by a "+" to designate being inside that range, or a "-" to
2844 designate being outside that range, so the condition can be inverted by
2845 flipping the prefix. An omitted bound is represented by a "-". For
2846 example, "- [-, 10]" means being outside the range starting at the lowest
2847 possible value and ending at 10, in other words, being greater than 10.
2848 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
2851 We set up things so that the missing bounds are handled in a consistent
2852 manner so neither a missing bound nor "true" and "false" need to be
2853 handled using a special case. */
2855 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
2856 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
2857 and UPPER1_P are nonzero if the respective argument is an upper bound
2858 and zero for a lower. TYPE, if nonzero, is the type of the result; it
2859 must be specified for a comparison. ARG1 will be converted to ARG0's
2860 type if both are specified. */
2863 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
2864 tree arg1, int upper1_p)
2870 /* If neither arg represents infinity, do the normal operation.
2871 Else, if not a comparison, return infinity. Else handle the special
2872 comparison rules. Note that most of the cases below won't occur, but
2873 are handled for consistency. */
2875 if (arg0 != 0 && arg1 != 0)
2877 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
2878 arg0, convert (TREE_TYPE (arg0), arg1)));
2880 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
2883 if (TREE_CODE_CLASS (code) != '<')
2886 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
2887 for neither. In real maths, we cannot assume open ended ranges are
2888 the same. But, this is computer arithmetic, where numbers are finite.
2889 We can therefore make the transformation of any unbounded range with
2890 the value Z, Z being greater than any representable number. This permits
2891 us to treat unbounded ranges as equal. */
2892 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
2893 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
2897 result = sgn0 == sgn1;
2900 result = sgn0 != sgn1;
2903 result = sgn0 < sgn1;
2906 result = sgn0 <= sgn1;
2909 result = sgn0 > sgn1;
2912 result = sgn0 >= sgn1;
2918 return convert (type, result ? integer_one_node : integer_zero_node);
2921 /* Given EXP, a logical expression, set the range it is testing into
2922 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
2923 actually being tested. *PLOW and *PHIGH will be made of the same type
2924 as the returned expression. If EXP is not a comparison, we will most
2925 likely not be returning a useful value and range. */
2928 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
2930 enum tree_code code;
2931 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
2932 tree orig_type = NULL_TREE;
2934 tree low, high, n_low, n_high;
2936 /* Start with simply saying "EXP != 0" and then look at the code of EXP
2937 and see if we can refine the range. Some of the cases below may not
2938 happen, but it doesn't seem worth worrying about this. We "continue"
2939 the outer loop when we've changed something; otherwise we "break"
2940 the switch, which will "break" the while. */
2942 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
2946 code = TREE_CODE (exp);
2948 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
2950 if (first_rtl_op (code) > 0)
2951 arg0 = TREE_OPERAND (exp, 0);
2952 if (TREE_CODE_CLASS (code) == '<'
2953 || TREE_CODE_CLASS (code) == '1'
2954 || TREE_CODE_CLASS (code) == '2')
2955 type = TREE_TYPE (arg0);
2956 if (TREE_CODE_CLASS (code) == '2'
2957 || TREE_CODE_CLASS (code) == '<'
2958 || (TREE_CODE_CLASS (code) == 'e'
2959 && TREE_CODE_LENGTH (code) > 1))
2960 arg1 = TREE_OPERAND (exp, 1);
2963 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
2964 lose a cast by accident. */
2965 if (type != NULL_TREE && orig_type == NULL_TREE)
2970 case TRUTH_NOT_EXPR:
2971 in_p = ! in_p, exp = arg0;
2974 case EQ_EXPR: case NE_EXPR:
2975 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
2976 /* We can only do something if the range is testing for zero
2977 and if the second operand is an integer constant. Note that
2978 saying something is "in" the range we make is done by
2979 complementing IN_P since it will set in the initial case of
2980 being not equal to zero; "out" is leaving it alone. */
2981 if (low == 0 || high == 0
2982 || ! integer_zerop (low) || ! integer_zerop (high)
2983 || TREE_CODE (arg1) != INTEGER_CST)
2988 case NE_EXPR: /* - [c, c] */
2991 case EQ_EXPR: /* + [c, c] */
2992 in_p = ! in_p, low = high = arg1;
2994 case GT_EXPR: /* - [-, c] */
2995 low = 0, high = arg1;
2997 case GE_EXPR: /* + [c, -] */
2998 in_p = ! in_p, low = arg1, high = 0;
3000 case LT_EXPR: /* - [c, -] */
3001 low = arg1, high = 0;
3003 case LE_EXPR: /* + [-, c] */
3004 in_p = ! in_p, low = 0, high = arg1;
3012 /* If this is an unsigned comparison, we also know that EXP is
3013 greater than or equal to zero. We base the range tests we make
3014 on that fact, so we record it here so we can parse existing
3016 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3018 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3019 1, convert (type, integer_zero_node),
3023 in_p = n_in_p, low = n_low, high = n_high;
3025 /* If the high bound is missing, but we
3026 have a low bound, reverse the range so
3027 it goes from zero to the low bound minus 1. */
3028 if (high == 0 && low)
3031 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3032 integer_one_node, 0);
3033 low = convert (type, integer_zero_node);
3039 /* (-x) IN [a,b] -> x in [-b, -a] */
3040 n_low = range_binop (MINUS_EXPR, type,
3041 convert (type, integer_zero_node), 0, high, 1);
3042 n_high = range_binop (MINUS_EXPR, type,
3043 convert (type, integer_zero_node), 0, low, 0);
3044 low = n_low, high = n_high;
3050 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3051 convert (type, integer_one_node));
3054 case PLUS_EXPR: case MINUS_EXPR:
3055 if (TREE_CODE (arg1) != INTEGER_CST)
3058 /* If EXP is signed, any overflow in the computation is undefined,
3059 so we don't worry about it so long as our computations on
3060 the bounds don't overflow. For unsigned, overflow is defined
3061 and this is exactly the right thing. */
3062 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3063 type, low, 0, arg1, 0);
3064 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3065 type, high, 1, arg1, 0);
3066 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3067 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3070 /* Check for an unsigned range which has wrapped around the maximum
3071 value thus making n_high < n_low, and normalize it. */
3072 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3074 low = range_binop (PLUS_EXPR, type, n_high, 0,
3075 integer_one_node, 0);
3076 high = range_binop (MINUS_EXPR, type, n_low, 0,
3077 integer_one_node, 0);
3079 /* If the range is of the form +/- [ x+1, x ], we won't
3080 be able to normalize it. But then, it represents the
3081 whole range or the empty set, so make it
3083 if (tree_int_cst_equal (n_low, low)
3084 && tree_int_cst_equal (n_high, high))
3090 low = n_low, high = n_high;
3095 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3096 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3099 if (! INTEGRAL_TYPE_P (type)
3100 || (low != 0 && ! int_fits_type_p (low, type))
3101 || (high != 0 && ! int_fits_type_p (high, type)))
3104 n_low = low, n_high = high;
3107 n_low = convert (type, n_low);
3110 n_high = convert (type, n_high);
3112 /* If we're converting from an unsigned to a signed type,
3113 we will be doing the comparison as unsigned. The tests above
3114 have already verified that LOW and HIGH are both positive.
3116 So we have to make sure that the original unsigned value will
3117 be interpreted as positive. */
3118 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3120 tree equiv_type = (*lang_hooks.types.type_for_mode)
3121 (TYPE_MODE (type), 1);
3124 /* A range without an upper bound is, naturally, unbounded.
3125 Since convert would have cropped a very large value, use
3126 the max value for the destination type. */
3128 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3129 : TYPE_MAX_VALUE (type);
3131 if (TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (exp)))
3132 high_positive = fold (build (RSHIFT_EXPR, type,
3133 convert (type, high_positive),
3134 convert (type, integer_one_node)));
3136 /* If the low bound is specified, "and" the range with the
3137 range for which the original unsigned value will be
3141 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3143 1, convert (type, integer_zero_node),
3147 in_p = (n_in_p == in_p);
3151 /* Otherwise, "or" the range with the range of the input
3152 that will be interpreted as negative. */
3153 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3155 1, convert (type, integer_zero_node),
3159 in_p = (in_p != n_in_p);
3164 low = n_low, high = n_high;
3174 /* If EXP is a constant, we can evaluate whether this is true or false. */
3175 if (TREE_CODE (exp) == INTEGER_CST)
3177 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3179 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3185 *pin_p = in_p, *plow = low, *phigh = high;
3189 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3190 type, TYPE, return an expression to test if EXP is in (or out of, depending
3191 on IN_P) the range. */
3194 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3196 tree etype = TREE_TYPE (exp);
3200 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3201 return invert_truthvalue (value);
3203 if (low == 0 && high == 0)
3204 return convert (type, integer_one_node);
3207 return fold (build (LE_EXPR, type, exp, high));
3210 return fold (build (GE_EXPR, type, exp, low));
3212 if (operand_equal_p (low, high, 0))
3213 return fold (build (EQ_EXPR, type, exp, low));
3215 if (integer_zerop (low))
3217 if (! TREE_UNSIGNED (etype))
3219 etype = (*lang_hooks.types.unsigned_type) (etype);
3220 high = convert (etype, high);
3221 exp = convert (etype, exp);
3223 return build_range_check (type, exp, 1, 0, high);
3226 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3227 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3229 unsigned HOST_WIDE_INT lo;
3233 prec = TYPE_PRECISION (etype);
3234 if (prec <= HOST_BITS_PER_WIDE_INT)
3237 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3241 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3242 lo = (unsigned HOST_WIDE_INT) -1;
3245 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3247 if (TREE_UNSIGNED (etype))
3249 etype = (*lang_hooks.types.signed_type) (etype);
3250 exp = convert (etype, exp);
3252 return fold (build (GT_EXPR, type, exp,
3253 convert (etype, integer_zero_node)));
3257 if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3258 && ! TREE_OVERFLOW (value))
3259 return build_range_check (type,
3260 fold (build (MINUS_EXPR, etype, exp, low)),
3261 1, convert (etype, integer_zero_node), value);
3266 /* Given two ranges, see if we can merge them into one. Return 1 if we
3267 can, 0 if we can't. Set the output range into the specified parameters. */
3270 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
3271 tree high0, int in1_p, tree low1, tree high1)
3279 int lowequal = ((low0 == 0 && low1 == 0)
3280 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3281 low0, 0, low1, 0)));
3282 int highequal = ((high0 == 0 && high1 == 0)
3283 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3284 high0, 1, high1, 1)));
3286 /* Make range 0 be the range that starts first, or ends last if they
3287 start at the same value. Swap them if it isn't. */
3288 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3291 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3292 high1, 1, high0, 1))))
3294 temp = in0_p, in0_p = in1_p, in1_p = temp;
3295 tem = low0, low0 = low1, low1 = tem;
3296 tem = high0, high0 = high1, high1 = tem;
3299 /* Now flag two cases, whether the ranges are disjoint or whether the
3300 second range is totally subsumed in the first. Note that the tests
3301 below are simplified by the ones above. */
3302 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3303 high0, 1, low1, 0));
3304 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3305 high1, 1, high0, 1));
3307 /* We now have four cases, depending on whether we are including or
3308 excluding the two ranges. */
3311 /* If they don't overlap, the result is false. If the second range
3312 is a subset it is the result. Otherwise, the range is from the start
3313 of the second to the end of the first. */
3315 in_p = 0, low = high = 0;
3317 in_p = 1, low = low1, high = high1;
3319 in_p = 1, low = low1, high = high0;
3322 else if (in0_p && ! in1_p)
3324 /* If they don't overlap, the result is the first range. If they are
3325 equal, the result is false. If the second range is a subset of the
3326 first, and the ranges begin at the same place, we go from just after
3327 the end of the first range to the end of the second. If the second
3328 range is not a subset of the first, or if it is a subset and both
3329 ranges end at the same place, the range starts at the start of the
3330 first range and ends just before the second range.
3331 Otherwise, we can't describe this as a single range. */
3333 in_p = 1, low = low0, high = high0;
3334 else if (lowequal && highequal)
3335 in_p = 0, low = high = 0;
3336 else if (subset && lowequal)
3338 in_p = 1, high = high0;
3339 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3340 integer_one_node, 0);
3342 else if (! subset || highequal)
3344 in_p = 1, low = low0;
3345 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3346 integer_one_node, 0);
3352 else if (! in0_p && in1_p)
3354 /* If they don't overlap, the result is the second range. If the second
3355 is a subset of the first, the result is false. Otherwise,
3356 the range starts just after the first range and ends at the
3357 end of the second. */
3359 in_p = 1, low = low1, high = high1;
3360 else if (subset || highequal)
3361 in_p = 0, low = high = 0;
3364 in_p = 1, high = high1;
3365 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3366 integer_one_node, 0);
3372 /* The case where we are excluding both ranges. Here the complex case
3373 is if they don't overlap. In that case, the only time we have a
3374 range is if they are adjacent. If the second is a subset of the
3375 first, the result is the first. Otherwise, the range to exclude
3376 starts at the beginning of the first range and ends at the end of the
3380 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3381 range_binop (PLUS_EXPR, NULL_TREE,
3383 integer_one_node, 1),
3385 in_p = 0, low = low0, high = high1;
3390 in_p = 0, low = low0, high = high0;
3392 in_p = 0, low = low0, high = high1;
3395 *pin_p = in_p, *plow = low, *phigh = high;
3399 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
3400 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
3403 /* EXP is some logical combination of boolean tests. See if we can
3404 merge it into some range test. Return the new tree if so. */
3407 fold_range_test (tree exp)
3409 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3410 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3411 int in0_p, in1_p, in_p;
3412 tree low0, low1, low, high0, high1, high;
3413 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3414 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3417 /* If this is an OR operation, invert both sides; we will invert
3418 again at the end. */
3420 in0_p = ! in0_p, in1_p = ! in1_p;
3422 /* If both expressions are the same, if we can merge the ranges, and we
3423 can build the range test, return it or it inverted. If one of the
3424 ranges is always true or always false, consider it to be the same
3425 expression as the other. */
3426 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3427 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3429 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3431 : rhs != 0 ? rhs : integer_zero_node,
3433 return or_op ? invert_truthvalue (tem) : tem;
3435 /* On machines where the branch cost is expensive, if this is a
3436 short-circuited branch and the underlying object on both sides
3437 is the same, make a non-short-circuit operation. */
3438 else if (RANGE_TEST_NON_SHORT_CIRCUIT
3439 && lhs != 0 && rhs != 0
3440 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3441 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3442 && operand_equal_p (lhs, rhs, 0))
3444 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3445 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3446 which cases we can't do this. */
3447 if (simple_operand_p (lhs))
3448 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3449 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3450 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3451 TREE_OPERAND (exp, 1));
3453 else if ((*lang_hooks.decls.global_bindings_p) () == 0
3454 && ! CONTAINS_PLACEHOLDER_P (lhs))
3456 tree common = save_expr (lhs);
3458 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3459 or_op ? ! in0_p : in0_p,
3461 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3462 or_op ? ! in1_p : in1_p,
3464 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3465 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3466 TREE_TYPE (exp), lhs, rhs);
3473 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3474 bit value. Arrange things so the extra bits will be set to zero if and
3475 only if C is signed-extended to its full width. If MASK is nonzero,
3476 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3479 unextend (tree c, int p, int unsignedp, tree mask)
3481 tree type = TREE_TYPE (c);
3482 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3485 if (p == modesize || unsignedp)
3488 /* We work by getting just the sign bit into the low-order bit, then
3489 into the high-order bit, then sign-extend. We then XOR that value
3491 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3492 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3494 /* We must use a signed type in order to get an arithmetic right shift.
3495 However, we must also avoid introducing accidental overflows, so that
3496 a subsequent call to integer_zerop will work. Hence we must
3497 do the type conversion here. At this point, the constant is either
3498 zero or one, and the conversion to a signed type can never overflow.
3499 We could get an overflow if this conversion is done anywhere else. */
3500 if (TREE_UNSIGNED (type))
3501 temp = convert ((*lang_hooks.types.signed_type) (type), temp);
3503 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3504 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3506 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3507 /* If necessary, convert the type back to match the type of C. */
3508 if (TREE_UNSIGNED (type))
3509 temp = convert (type, temp);
3511 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3514 /* Find ways of folding logical expressions of LHS and RHS:
3515 Try to merge two comparisons to the same innermost item.
3516 Look for range tests like "ch >= '0' && ch <= '9'".
3517 Look for combinations of simple terms on machines with expensive branches
3518 and evaluate the RHS unconditionally.
3520 For example, if we have p->a == 2 && p->b == 4 and we can make an
3521 object large enough to span both A and B, we can do this with a comparison
3522 against the object ANDed with the a mask.
3524 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3525 operations to do this with one comparison.
3527 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3528 function and the one above.
3530 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3531 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3533 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3536 We return the simplified tree or 0 if no optimization is possible. */
3539 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
3541 /* If this is the "or" of two comparisons, we can do something if
3542 the comparisons are NE_EXPR. If this is the "and", we can do something
3543 if the comparisons are EQ_EXPR. I.e.,
3544 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3546 WANTED_CODE is this operation code. For single bit fields, we can
3547 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3548 comparison for one-bit fields. */
3550 enum tree_code wanted_code;
3551 enum tree_code lcode, rcode;
3552 tree ll_arg, lr_arg, rl_arg, rr_arg;
3553 tree ll_inner, lr_inner, rl_inner, rr_inner;
3554 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3555 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3556 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3557 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3558 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3559 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3560 enum machine_mode lnmode, rnmode;
3561 tree ll_mask, lr_mask, rl_mask, rr_mask;
3562 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3563 tree l_const, r_const;
3564 tree lntype, rntype, result;
3565 int first_bit, end_bit;
3568 /* Start by getting the comparison codes. Fail if anything is volatile.
3569 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3570 it were surrounded with a NE_EXPR. */
3572 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3575 lcode = TREE_CODE (lhs);
3576 rcode = TREE_CODE (rhs);
3578 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3579 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3581 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3582 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3584 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3587 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3588 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3590 ll_arg = TREE_OPERAND (lhs, 0);
3591 lr_arg = TREE_OPERAND (lhs, 1);
3592 rl_arg = TREE_OPERAND (rhs, 0);
3593 rr_arg = TREE_OPERAND (rhs, 1);
3595 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
3596 if (simple_operand_p (ll_arg)
3597 && simple_operand_p (lr_arg)
3598 && !FLOAT_TYPE_P (TREE_TYPE (ll_arg)))
3602 if (operand_equal_p (ll_arg, rl_arg, 0)
3603 && operand_equal_p (lr_arg, rr_arg, 0))
3605 int lcompcode, rcompcode;
3607 lcompcode = comparison_to_compcode (lcode);
3608 rcompcode = comparison_to_compcode (rcode);
3609 compcode = (code == TRUTH_AND_EXPR)
3610 ? lcompcode & rcompcode
3611 : lcompcode | rcompcode;
3613 else if (operand_equal_p (ll_arg, rr_arg, 0)
3614 && operand_equal_p (lr_arg, rl_arg, 0))
3616 int lcompcode, rcompcode;
3618 rcode = swap_tree_comparison (rcode);
3619 lcompcode = comparison_to_compcode (lcode);
3620 rcompcode = comparison_to_compcode (rcode);
3621 compcode = (code == TRUTH_AND_EXPR)
3622 ? lcompcode & rcompcode
3623 : lcompcode | rcompcode;
3628 if (compcode == COMPCODE_TRUE)
3629 return convert (truth_type, integer_one_node);
3630 else if (compcode == COMPCODE_FALSE)
3631 return convert (truth_type, integer_zero_node);
3632 else if (compcode != -1)
3633 return build (compcode_to_comparison (compcode),
3634 truth_type, ll_arg, lr_arg);
3637 /* If the RHS can be evaluated unconditionally and its operands are
3638 simple, it wins to evaluate the RHS unconditionally on machines
3639 with expensive branches. In this case, this isn't a comparison
3640 that can be merged. Avoid doing this if the RHS is a floating-point
3641 comparison since those can trap. */
3643 if (BRANCH_COST >= 2
3644 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
3645 && simple_operand_p (rl_arg)
3646 && simple_operand_p (rr_arg))
3648 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
3649 if (code == TRUTH_OR_EXPR
3650 && lcode == NE_EXPR && integer_zerop (lr_arg)
3651 && rcode == NE_EXPR && integer_zerop (rr_arg)
3652 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
3653 return build (NE_EXPR, truth_type,
3654 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
3658 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
3659 if (code == TRUTH_AND_EXPR
3660 && lcode == EQ_EXPR && integer_zerop (lr_arg)
3661 && rcode == EQ_EXPR && integer_zerop (rr_arg)
3662 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
3663 return build (EQ_EXPR, truth_type,
3664 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
3668 return build (code, truth_type, lhs, rhs);
3671 /* See if the comparisons can be merged. Then get all the parameters for
3674 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3675 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3679 ll_inner = decode_field_reference (ll_arg,
3680 &ll_bitsize, &ll_bitpos, &ll_mode,
3681 &ll_unsignedp, &volatilep, &ll_mask,
3683 lr_inner = decode_field_reference (lr_arg,
3684 &lr_bitsize, &lr_bitpos, &lr_mode,
3685 &lr_unsignedp, &volatilep, &lr_mask,
3687 rl_inner = decode_field_reference (rl_arg,
3688 &rl_bitsize, &rl_bitpos, &rl_mode,
3689 &rl_unsignedp, &volatilep, &rl_mask,
3691 rr_inner = decode_field_reference (rr_arg,
3692 &rr_bitsize, &rr_bitpos, &rr_mode,
3693 &rr_unsignedp, &volatilep, &rr_mask,
3696 /* It must be true that the inner operation on the lhs of each
3697 comparison must be the same if we are to be able to do anything.
3698 Then see if we have constants. If not, the same must be true for
3700 if (volatilep || ll_inner == 0 || rl_inner == 0
3701 || ! operand_equal_p (ll_inner, rl_inner, 0))
3704 if (TREE_CODE (lr_arg) == INTEGER_CST
3705 && TREE_CODE (rr_arg) == INTEGER_CST)
3706 l_const = lr_arg, r_const = rr_arg;
3707 else if (lr_inner == 0 || rr_inner == 0
3708 || ! operand_equal_p (lr_inner, rr_inner, 0))
3711 l_const = r_const = 0;
3713 /* If either comparison code is not correct for our logical operation,
3714 fail. However, we can convert a one-bit comparison against zero into
3715 the opposite comparison against that bit being set in the field. */
3717 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
3718 if (lcode != wanted_code)
3720 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
3722 /* Make the left operand unsigned, since we are only interested
3723 in the value of one bit. Otherwise we are doing the wrong
3732 /* This is analogous to the code for l_const above. */
3733 if (rcode != wanted_code)
3735 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
3744 /* After this point all optimizations will generate bit-field
3745 references, which we might not want. */
3746 if (! (*lang_hooks.can_use_bit_fields_p) ())
3749 /* See if we can find a mode that contains both fields being compared on
3750 the left. If we can't, fail. Otherwise, update all constants and masks
3751 to be relative to a field of that size. */
3752 first_bit = MIN (ll_bitpos, rl_bitpos);
3753 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
3754 lnmode = get_best_mode (end_bit - first_bit, first_bit,
3755 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
3757 if (lnmode == VOIDmode)
3760 lnbitsize = GET_MODE_BITSIZE (lnmode);
3761 lnbitpos = first_bit & ~ (lnbitsize - 1);
3762 lntype = (*lang_hooks.types.type_for_size) (lnbitsize, 1);
3763 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
3765 if (BYTES_BIG_ENDIAN)
3767 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
3768 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
3771 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
3772 size_int (xll_bitpos), 0);
3773 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
3774 size_int (xrl_bitpos), 0);
3778 l_const = convert (lntype, l_const);
3779 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
3780 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
3781 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
3782 fold (build1 (BIT_NOT_EXPR,
3786 warning ("comparison is always %d", wanted_code == NE_EXPR);
3788 return convert (truth_type,
3789 wanted_code == NE_EXPR
3790 ? integer_one_node : integer_zero_node);
3795 r_const = convert (lntype, r_const);
3796 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
3797 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
3798 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
3799 fold (build1 (BIT_NOT_EXPR,
3803 warning ("comparison is always %d", wanted_code == NE_EXPR);
3805 return convert (truth_type,
3806 wanted_code == NE_EXPR
3807 ? integer_one_node : integer_zero_node);
3811 /* If the right sides are not constant, do the same for it. Also,
3812 disallow this optimization if a size or signedness mismatch occurs
3813 between the left and right sides. */
3816 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
3817 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
3818 /* Make sure the two fields on the right
3819 correspond to the left without being swapped. */
3820 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
3823 first_bit = MIN (lr_bitpos, rr_bitpos);
3824 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
3825 rnmode = get_best_mode (end_bit - first_bit, first_bit,
3826 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
3828 if (rnmode == VOIDmode)
3831 rnbitsize = GET_MODE_BITSIZE (rnmode);
3832 rnbitpos = first_bit & ~ (rnbitsize - 1);
3833 rntype = (*lang_hooks.types.type_for_size) (rnbitsize, 1);
3834 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
3836 if (BYTES_BIG_ENDIAN)
3838 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
3839 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
3842 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
3843 size_int (xlr_bitpos), 0);
3844 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
3845 size_int (xrr_bitpos), 0);
3847 /* Make a mask that corresponds to both fields being compared.
3848 Do this for both items being compared. If the operands are the
3849 same size and the bits being compared are in the same position
3850 then we can do this by masking both and comparing the masked
3852 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3853 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
3854 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
3856 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
3857 ll_unsignedp || rl_unsignedp);
3858 if (! all_ones_mask_p (ll_mask, lnbitsize))
3859 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
3861 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
3862 lr_unsignedp || rr_unsignedp);
3863 if (! all_ones_mask_p (lr_mask, rnbitsize))
3864 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
3866 return build (wanted_code, truth_type, lhs, rhs);
3869 /* There is still another way we can do something: If both pairs of
3870 fields being compared are adjacent, we may be able to make a wider
3871 field containing them both.
3873 Note that we still must mask the lhs/rhs expressions. Furthermore,
3874 the mask must be shifted to account for the shift done by
3875 make_bit_field_ref. */
3876 if ((ll_bitsize + ll_bitpos == rl_bitpos
3877 && lr_bitsize + lr_bitpos == rr_bitpos)
3878 || (ll_bitpos == rl_bitpos + rl_bitsize
3879 && lr_bitpos == rr_bitpos + rr_bitsize))
3883 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
3884 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
3885 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
3886 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
3888 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
3889 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
3890 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
3891 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
3893 /* Convert to the smaller type before masking out unwanted bits. */
3895 if (lntype != rntype)
3897 if (lnbitsize > rnbitsize)
3899 lhs = convert (rntype, lhs);
3900 ll_mask = convert (rntype, ll_mask);
3903 else if (lnbitsize < rnbitsize)
3905 rhs = convert (lntype, rhs);
3906 lr_mask = convert (lntype, lr_mask);
3911 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
3912 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
3914 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
3915 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
3917 return build (wanted_code, truth_type, lhs, rhs);
3923 /* Handle the case of comparisons with constants. If there is something in
3924 common between the masks, those bits of the constants must be the same.
3925 If not, the condition is always false. Test for this to avoid generating
3926 incorrect code below. */
3927 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
3928 if (! integer_zerop (result)
3929 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
3930 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
3932 if (wanted_code == NE_EXPR)
3934 warning ("`or' of unmatched not-equal tests is always 1");
3935 return convert (truth_type, integer_one_node);
3939 warning ("`and' of mutually exclusive equal-tests is always 0");
3940 return convert (truth_type, integer_zero_node);
3944 /* Construct the expression we will return. First get the component
3945 reference we will make. Unless the mask is all ones the width of
3946 that field, perform the mask operation. Then compare with the
3948 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
3949 ll_unsignedp || rl_unsignedp);
3951 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3952 if (! all_ones_mask_p (ll_mask, lnbitsize))
3953 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
3955 return build (wanted_code, truth_type, result,
3956 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
3959 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
3963 optimize_minmax_comparison (tree t)
3965 tree type = TREE_TYPE (t);
3966 tree arg0 = TREE_OPERAND (t, 0);
3967 enum tree_code op_code;
3968 tree comp_const = TREE_OPERAND (t, 1);
3970 int consts_equal, consts_lt;
3973 STRIP_SIGN_NOPS (arg0);
3975 op_code = TREE_CODE (arg0);
3976 minmax_const = TREE_OPERAND (arg0, 1);
3977 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
3978 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
3979 inner = TREE_OPERAND (arg0, 0);
3981 /* If something does not permit us to optimize, return the original tree. */
3982 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
3983 || TREE_CODE (comp_const) != INTEGER_CST
3984 || TREE_CONSTANT_OVERFLOW (comp_const)
3985 || TREE_CODE (minmax_const) != INTEGER_CST
3986 || TREE_CONSTANT_OVERFLOW (minmax_const))
3989 /* Now handle all the various comparison codes. We only handle EQ_EXPR
3990 and GT_EXPR, doing the rest with recursive calls using logical
3992 switch (TREE_CODE (t))
3994 case NE_EXPR: case LT_EXPR: case LE_EXPR:
3996 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4000 fold (build (TRUTH_ORIF_EXPR, type,
4001 optimize_minmax_comparison
4002 (build (EQ_EXPR, type, arg0, comp_const)),
4003 optimize_minmax_comparison
4004 (build (GT_EXPR, type, arg0, comp_const))));
4007 if (op_code == MAX_EXPR && consts_equal)
4008 /* MAX (X, 0) == 0 -> X <= 0 */
4009 return fold (build (LE_EXPR, type, inner, comp_const));
4011 else if (op_code == MAX_EXPR && consts_lt)
4012 /* MAX (X, 0) == 5 -> X == 5 */
4013 return fold (build (EQ_EXPR, type, inner, comp_const));
4015 else if (op_code == MAX_EXPR)
4016 /* MAX (X, 0) == -1 -> false */
4017 return omit_one_operand (type, integer_zero_node, inner);
4019 else if (consts_equal)
4020 /* MIN (X, 0) == 0 -> X >= 0 */
4021 return fold (build (GE_EXPR, type, inner, comp_const));
4024 /* MIN (X, 0) == 5 -> false */
4025 return omit_one_operand (type, integer_zero_node, inner);
4028 /* MIN (X, 0) == -1 -> X == -1 */
4029 return fold (build (EQ_EXPR, type, inner, comp_const));
4032 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4033 /* MAX (X, 0) > 0 -> X > 0
4034 MAX (X, 0) > 5 -> X > 5 */
4035 return fold (build (GT_EXPR, type, inner, comp_const));
4037 else if (op_code == MAX_EXPR)
4038 /* MAX (X, 0) > -1 -> true */
4039 return omit_one_operand (type, integer_one_node, inner);
4041 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4042 /* MIN (X, 0) > 0 -> false
4043 MIN (X, 0) > 5 -> false */
4044 return omit_one_operand (type, integer_zero_node, inner);
4047 /* MIN (X, 0) > -1 -> X > -1 */
4048 return fold (build (GT_EXPR, type, inner, comp_const));
4055 /* T is an integer expression that is being multiplied, divided, or taken a
4056 modulus (CODE says which and what kind of divide or modulus) by a
4057 constant C. See if we can eliminate that operation by folding it with
4058 other operations already in T. WIDE_TYPE, if non-null, is a type that
4059 should be used for the computation if wider than our type.
4061 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4062 (X * 2) + (Y * 4). We must, however, be assured that either the original
4063 expression would not overflow or that overflow is undefined for the type
4064 in the language in question.
4066 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4067 the machine has a multiply-accumulate insn or that this is part of an
4068 addressing calculation.
4070 If we return a non-null expression, it is an equivalent form of the
4071 original computation, but need not be in the original type. */
4074 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
4076 /* To avoid exponential search depth, refuse to allow recursion past
4077 three levels. Beyond that (1) it's highly unlikely that we'll find
4078 something interesting and (2) we've probably processed it before
4079 when we built the inner expression. */
4088 ret = extract_muldiv_1 (t, c, code, wide_type);
4095 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
4097 tree type = TREE_TYPE (t);
4098 enum tree_code tcode = TREE_CODE (t);
4099 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4100 > GET_MODE_SIZE (TYPE_MODE (type)))
4101 ? wide_type : type);
4103 int same_p = tcode == code;
4104 tree op0 = NULL_TREE, op1 = NULL_TREE;
4106 /* Don't deal with constants of zero here; they confuse the code below. */
4107 if (integer_zerop (c))
4110 if (TREE_CODE_CLASS (tcode) == '1')
4111 op0 = TREE_OPERAND (t, 0);
4113 if (TREE_CODE_CLASS (tcode) == '2')
4114 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4116 /* Note that we need not handle conditional operations here since fold
4117 already handles those cases. So just do arithmetic here. */
4121 /* For a constant, we can always simplify if we are a multiply
4122 or (for divide and modulus) if it is a multiple of our constant. */
4123 if (code == MULT_EXPR
4124 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4125 return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
4128 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4129 /* If op0 is an expression ... */
4130 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
4131 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
4132 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
4133 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
4134 /* ... and is unsigned, and its type is smaller than ctype,
4135 then we cannot pass through as widening. */
4136 && ((TREE_UNSIGNED (TREE_TYPE (op0))
4137 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
4138 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
4139 && (GET_MODE_SIZE (TYPE_MODE (ctype))
4140 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
4141 /* ... or its type is larger than ctype,
4142 then we cannot pass through this truncation. */
4143 || (GET_MODE_SIZE (TYPE_MODE (ctype))
4144 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
4145 /* ... or signedness changes for division or modulus,
4146 then we cannot pass through this conversion. */
4147 || (code != MULT_EXPR
4148 && (TREE_UNSIGNED (ctype)
4149 != TREE_UNSIGNED (TREE_TYPE (op0))))))
4152 /* Pass the constant down and see if we can make a simplification. If
4153 we can, replace this expression with the inner simplification for
4154 possible later conversion to our or some other type. */
4155 if ((t2 = convert (TREE_TYPE (op0), c)) != 0
4156 && TREE_CODE (t2) == INTEGER_CST
4157 && ! TREE_CONSTANT_OVERFLOW (t2)
4158 && (0 != (t1 = extract_muldiv (op0, t2, code,
4160 ? ctype : NULL_TREE))))
4164 case NEGATE_EXPR: case ABS_EXPR:
4165 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4166 return fold (build1 (tcode, ctype, convert (ctype, t1)));
4169 case MIN_EXPR: case MAX_EXPR:
4170 /* If widening the type changes the signedness, then we can't perform
4171 this optimization as that changes the result. */
4172 if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
4175 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4176 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4177 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4179 if (tree_int_cst_sgn (c) < 0)
4180 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4182 return fold (build (tcode, ctype, convert (ctype, t1),
4183 convert (ctype, t2)));
4187 case WITH_RECORD_EXPR:
4188 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4189 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4190 TREE_OPERAND (t, 1));
4193 case LSHIFT_EXPR: case RSHIFT_EXPR:
4194 /* If the second operand is constant, this is a multiplication
4195 or floor division, by a power of two, so we can treat it that
4196 way unless the multiplier or divisor overflows. */
4197 if (TREE_CODE (op1) == INTEGER_CST
4198 /* const_binop may not detect overflow correctly,
4199 so check for it explicitly here. */
4200 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
4201 && TREE_INT_CST_HIGH (op1) == 0
4202 && 0 != (t1 = convert (ctype,
4203 const_binop (LSHIFT_EXPR, size_one_node,
4205 && ! TREE_OVERFLOW (t1))
4206 return extract_muldiv (build (tcode == LSHIFT_EXPR
4207 ? MULT_EXPR : FLOOR_DIV_EXPR,
4208 ctype, convert (ctype, op0), t1),
4209 c, code, wide_type);
4212 case PLUS_EXPR: case MINUS_EXPR:
4213 /* See if we can eliminate the operation on both sides. If we can, we
4214 can return a new PLUS or MINUS. If we can't, the only remaining
4215 cases where we can do anything are if the second operand is a
4217 t1 = extract_muldiv (op0, c, code, wide_type);
4218 t2 = extract_muldiv (op1, c, code, wide_type);
4219 if (t1 != 0 && t2 != 0
4220 && (code == MULT_EXPR
4221 /* If not multiplication, we can only do this if both operands
4222 are divisible by c. */
4223 || (multiple_of_p (ctype, op0, c)
4224 && multiple_of_p (ctype, op1, c))))
4225 return fold (build (tcode, ctype, convert (ctype, t1),
4226 convert (ctype, t2)));
4228 /* If this was a subtraction, negate OP1 and set it to be an addition.
4229 This simplifies the logic below. */
4230 if (tcode == MINUS_EXPR)
4231 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4233 if (TREE_CODE (op1) != INTEGER_CST)
4236 /* If either OP1 or C are negative, this optimization is not safe for
4237 some of the division and remainder types while for others we need
4238 to change the code. */
4239 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4241 if (code == CEIL_DIV_EXPR)
4242 code = FLOOR_DIV_EXPR;
4243 else if (code == FLOOR_DIV_EXPR)
4244 code = CEIL_DIV_EXPR;
4245 else if (code != MULT_EXPR
4246 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
4250 /* If it's a multiply or a division/modulus operation of a multiple
4251 of our constant, do the operation and verify it doesn't overflow. */
4252 if (code == MULT_EXPR
4253 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4255 op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
4256 if (op1 == 0 || TREE_OVERFLOW (op1))
4262 /* If we have an unsigned type is not a sizetype, we cannot widen
4263 the operation since it will change the result if the original
4264 computation overflowed. */
4265 if (TREE_UNSIGNED (ctype)
4266 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
4270 /* If we were able to eliminate our operation from the first side,
4271 apply our operation to the second side and reform the PLUS. */
4272 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4273 return fold (build (tcode, ctype, convert (ctype, t1), op1));
4275 /* The last case is if we are a multiply. In that case, we can
4276 apply the distributive law to commute the multiply and addition
4277 if the multiplication of the constants doesn't overflow. */
4278 if (code == MULT_EXPR)
4279 return fold (build (tcode, ctype, fold (build (code, ctype,
4280 convert (ctype, op0),
4281 convert (ctype, c))),
4287 /* We have a special case here if we are doing something like
4288 (C * 8) % 4 since we know that's zero. */
4289 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4290 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4291 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4292 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4293 return omit_one_operand (type, integer_zero_node, op0);
4295 /* ... fall through ... */
4297 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4298 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4299 /* If we can extract our operation from the LHS, do so and return a
4300 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4301 do something only if the second operand is a constant. */
4303 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4304 return fold (build (tcode, ctype, convert (ctype, t1),
4305 convert (ctype, op1)));
4306 else if (tcode == MULT_EXPR && code == MULT_EXPR
4307 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4308 return fold (build (tcode, ctype, convert (ctype, op0),
4309 convert (ctype, t1)));
4310 else if (TREE_CODE (op1) != INTEGER_CST)
4313 /* If these are the same operation types, we can associate them
4314 assuming no overflow. */
4316 && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
4317 convert (ctype, c), 0))
4318 && ! TREE_OVERFLOW (t1))
4319 return fold (build (tcode, ctype, convert (ctype, op0), t1));
4321 /* If these operations "cancel" each other, we have the main
4322 optimizations of this pass, which occur when either constant is a
4323 multiple of the other, in which case we replace this with either an
4324 operation or CODE or TCODE.
4326 If we have an unsigned type that is not a sizetype, we cannot do
4327 this since it will change the result if the original computation
4329 if ((! TREE_UNSIGNED (ctype)
4330 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
4332 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4333 || (tcode == MULT_EXPR
4334 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4335 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
4337 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4338 return fold (build (tcode, ctype, convert (ctype, op0),
4340 const_binop (TRUNC_DIV_EXPR,
4342 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4343 return fold (build (code, ctype, convert (ctype, op0),
4345 const_binop (TRUNC_DIV_EXPR,
4357 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4358 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4359 that we may sometimes modify the tree. */
4362 strip_compound_expr (tree t, tree s)
4364 enum tree_code code = TREE_CODE (t);
4366 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4367 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4368 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4369 return TREE_OPERAND (t, 1);
4371 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4372 don't bother handling any other types. */
4373 else if (code == COND_EXPR)
4375 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4376 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4377 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4379 else if (TREE_CODE_CLASS (code) == '1')
4380 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4381 else if (TREE_CODE_CLASS (code) == '<'
4382 || TREE_CODE_CLASS (code) == '2')
4384 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4385 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4391 /* Return a node which has the indicated constant VALUE (either 0 or
4392 1), and is of the indicated TYPE. */
4395 constant_boolean_node (int value, tree type)
4397 if (type == integer_type_node)
4398 return value ? integer_one_node : integer_zero_node;
4399 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4400 return (*lang_hooks.truthvalue_conversion) (value ? integer_one_node :
4404 tree t = build_int_2 (value, 0);
4406 TREE_TYPE (t) = type;
4411 /* Utility function for the following routine, to see how complex a nesting of
4412 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4413 we don't care (to avoid spending too much time on complex expressions.). */
4416 count_cond (tree expr, int lim)
4420 if (TREE_CODE (expr) != COND_EXPR)
4425 ctrue = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4426 cfalse = count_cond (TREE_OPERAND (expr, 2), lim - 1 - ctrue);
4427 return MIN (lim, 1 + ctrue + cfalse);
4430 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
4431 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4432 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4433 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
4434 COND is the first argument to CODE; otherwise (as in the example
4435 given here), it is the second argument. TYPE is the type of the
4436 original expression. */
4439 fold_binary_op_with_conditional_arg (enum tree_code code, tree type,
4440 tree cond, tree arg, int cond_first_p)
4442 tree test, true_value, false_value;
4443 tree lhs = NULL_TREE;
4444 tree rhs = NULL_TREE;
4445 /* In the end, we'll produce a COND_EXPR. Both arms of the
4446 conditional expression will be binary operations. The left-hand
4447 side of the expression to be executed if the condition is true
4448 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4449 of the expression to be executed if the condition is true will be
4450 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4451 but apply to the expression to be executed if the conditional is
4457 /* These are the codes to use for the left-hand side and right-hand
4458 side of the COND_EXPR. Normally, they are the same as CODE. */
4459 enum tree_code lhs_code = code;
4460 enum tree_code rhs_code = code;
4461 /* And these are the types of the expressions. */
4462 tree lhs_type = type;
4463 tree rhs_type = type;
4468 true_rhs = false_rhs = &arg;
4469 true_lhs = &true_value;
4470 false_lhs = &false_value;
4474 true_lhs = false_lhs = &arg;
4475 true_rhs = &true_value;
4476 false_rhs = &false_value;
4479 if (TREE_CODE (cond) == COND_EXPR)
4481 test = TREE_OPERAND (cond, 0);
4482 true_value = TREE_OPERAND (cond, 1);
4483 false_value = TREE_OPERAND (cond, 2);
4484 /* If this operand throws an expression, then it does not make
4485 sense to try to perform a logical or arithmetic operation
4486 involving it. Instead of building `a + throw 3' for example,
4487 we simply build `a, throw 3'. */
4488 if (VOID_TYPE_P (TREE_TYPE (true_value)))
4492 lhs_code = COMPOUND_EXPR;
4493 lhs_type = void_type_node;
4498 if (VOID_TYPE_P (TREE_TYPE (false_value)))
4502 rhs_code = COMPOUND_EXPR;
4503 rhs_type = void_type_node;
4511 tree testtype = TREE_TYPE (cond);
4513 true_value = convert (testtype, integer_one_node);
4514 false_value = convert (testtype, integer_zero_node);
4517 /* If ARG is complex we want to make sure we only evaluate it once. Though
4518 this is only required if it is volatile, it might be more efficient even
4519 if it is not. However, if we succeed in folding one part to a constant,
4520 we do not need to make this SAVE_EXPR. Since we do this optimization
4521 primarily to see if we do end up with constant and this SAVE_EXPR
4522 interferes with later optimizations, suppressing it when we can is
4525 If we are not in a function, we can't make a SAVE_EXPR, so don't try to
4526 do so. Don't try to see if the result is a constant if an arm is a
4527 COND_EXPR since we get exponential behavior in that case. */
4529 if (saved_expr_p (arg))
4531 else if (lhs == 0 && rhs == 0
4532 && !TREE_CONSTANT (arg)
4533 && (*lang_hooks.decls.global_bindings_p) () == 0
4534 && ((TREE_CODE (arg) != VAR_DECL && TREE_CODE (arg) != PARM_DECL)
4535 || TREE_SIDE_EFFECTS (arg)))
4537 if (TREE_CODE (true_value) != COND_EXPR)
4538 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4540 if (TREE_CODE (false_value) != COND_EXPR)
4541 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4543 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4544 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4546 arg = save_expr (arg);
4553 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4555 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4557 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4560 return build (COMPOUND_EXPR, type,
4561 convert (void_type_node, arg),
4562 strip_compound_expr (test, arg));
4564 return convert (type, test);
4568 /* Subroutine of fold() that checks for the addition of +/- 0.0.
4570 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
4571 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
4572 ADDEND is the same as X.
4574 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
4575 and finite. The problematic cases are when X is zero, and its mode
4576 has signed zeros. In the case of rounding towards -infinity,
4577 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
4578 modes, X + 0 is not the same as X because -0 + 0 is 0. */
4581 fold_real_zero_addition_p (tree type, tree addend, int negate)
4583 if (!real_zerop (addend))
4586 /* Don't allow the fold with -fsignaling-nans. */
4587 if (HONOR_SNANS (TYPE_MODE (type)))
4590 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
4591 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
4594 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
4595 if (TREE_CODE (addend) == REAL_CST
4596 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
4599 /* The mode has signed zeros, and we have to honor their sign.
4600 In this situation, there is only one case we can return true for.
4601 X - 0 is the same as X unless rounding towards -infinity is
4603 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
4606 /* Subroutine of fold() that checks comparisons of built-in math
4607 functions against real constants.
4609 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
4610 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
4611 is the type of the result and ARG0 and ARG1 are the operands of the
4612 comparison. ARG1 must be a TREE_REAL_CST.
4614 The function returns the constant folded tree if a simplification
4615 can be made, and NULL_TREE otherwise. */
4618 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
4619 tree type, tree arg0, tree arg1)
4623 if (fcode == BUILT_IN_SQRT
4624 || fcode == BUILT_IN_SQRTF
4625 || fcode == BUILT_IN_SQRTL)
4627 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
4628 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
4630 c = TREE_REAL_CST (arg1);
4631 if (REAL_VALUE_NEGATIVE (c))
4633 /* sqrt(x) < y is always false, if y is negative. */
4634 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
4635 return omit_one_operand (type,
4636 convert (type, integer_zero_node),
4639 /* sqrt(x) > y is always true, if y is negative and we
4640 don't care about NaNs, i.e. negative values of x. */
4641 if (code == NE_EXPR || !HONOR_NANS (mode))
4642 return omit_one_operand (type,
4643 convert (type, integer_one_node),
4646 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
4647 return fold (build (GE_EXPR, type, arg,
4648 build_real (TREE_TYPE (arg), dconst0)));
4650 else if (code == GT_EXPR || code == GE_EXPR)
4654 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
4655 real_convert (&c2, mode, &c2);
4657 if (REAL_VALUE_ISINF (c2))
4659 /* sqrt(x) > y is x == +Inf, when y is very large. */
4660 if (HONOR_INFINITIES (mode))
4661 return fold (build (EQ_EXPR, type, arg,
4662 build_real (TREE_TYPE (arg), c2)));
4664 /* sqrt(x) > y is always false, when y is very large
4665 and we don't care about infinities. */
4666 return omit_one_operand (type,
4667 convert (type, integer_zero_node),
4671 /* sqrt(x) > c is the same as x > c*c. */
4672 return fold (build (code, type, arg,
4673 build_real (TREE_TYPE (arg), c2)));
4675 else if (code == LT_EXPR || code == LE_EXPR)
4679 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
4680 real_convert (&c2, mode, &c2);
4682 if (REAL_VALUE_ISINF (c2))
4684 /* sqrt(x) < y is always true, when y is a very large
4685 value and we don't care about NaNs or Infinities. */
4686 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
4687 return omit_one_operand (type,
4688 convert (type, integer_one_node),
4691 /* sqrt(x) < y is x != +Inf when y is very large and we
4692 don't care about NaNs. */
4693 if (! HONOR_NANS (mode))
4694 return fold (build (NE_EXPR, type, arg,
4695 build_real (TREE_TYPE (arg), c2)));
4697 /* sqrt(x) < y is x >= 0 when y is very large and we
4698 don't care about Infinities. */
4699 if (! HONOR_INFINITIES (mode))
4700 return fold (build (GE_EXPR, type, arg,
4701 build_real (TREE_TYPE (arg), dconst0)));
4703 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
4704 if ((*lang_hooks.decls.global_bindings_p) () != 0
4705 || CONTAINS_PLACEHOLDER_P (arg))
4708 arg = save_expr (arg);
4709 return fold (build (TRUTH_ANDIF_EXPR, type,
4710 fold (build (GE_EXPR, type, arg,
4711 build_real (TREE_TYPE (arg),
4713 fold (build (NE_EXPR, type, arg,
4714 build_real (TREE_TYPE (arg),
4718 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
4719 if (! HONOR_NANS (mode))
4720 return fold (build (code, type, arg,
4721 build_real (TREE_TYPE (arg), c2)));
4723 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
4724 if ((*lang_hooks.decls.global_bindings_p) () == 0
4725 && ! CONTAINS_PLACEHOLDER_P (arg))
4727 arg = save_expr (arg);
4728 return fold (build (TRUTH_ANDIF_EXPR, type,
4729 fold (build (GE_EXPR, type, arg,
4730 build_real (TREE_TYPE (arg),
4732 fold (build (code, type, arg,
4733 build_real (TREE_TYPE (arg),
4742 /* Subroutine of fold() that optimizes comparisons against Infinities,
4743 either +Inf or -Inf.
4745 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
4746 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
4747 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
4749 The function returns the constant folded tree if a simplification
4750 can be made, and NULL_TREE otherwise. */
4753 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
4755 enum machine_mode mode;
4756 REAL_VALUE_TYPE max;
4760 mode = TYPE_MODE (TREE_TYPE (arg0));
4762 /* For negative infinity swap the sense of the comparison. */
4763 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
4765 code = swap_tree_comparison (code);
4770 /* x > +Inf is always false, if with ignore sNANs. */
4771 if (HONOR_SNANS (mode))
4773 return omit_one_operand (type,
4774 convert (type, integer_zero_node),
4778 /* x <= +Inf is always true, if we don't case about NaNs. */
4779 if (! HONOR_NANS (mode))
4780 return omit_one_operand (type,
4781 convert (type, integer_one_node),
4784 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
4785 if ((*lang_hooks.decls.global_bindings_p) () == 0
4786 && ! CONTAINS_PLACEHOLDER_P (arg0))
4788 arg0 = save_expr (arg0);
4789 return fold (build (EQ_EXPR, type, arg0, arg0));
4795 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
4796 real_maxval (&max, neg, mode);
4797 return fold (build (neg ? LT_EXPR : GT_EXPR, type,
4798 arg0, build_real (TREE_TYPE (arg0), max)));
4801 /* x < +Inf is always equal to x <= DBL_MAX. */
4802 real_maxval (&max, neg, mode);
4803 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
4804 arg0, build_real (TREE_TYPE (arg0), max)));
4807 /* x != +Inf is always equal to !(x > DBL_MAX). */
4808 real_maxval (&max, neg, mode);
4809 if (! HONOR_NANS (mode))
4810 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
4811 arg0, build_real (TREE_TYPE (arg0), max)));
4812 temp = fold (build (neg ? LT_EXPR : GT_EXPR, type,
4813 arg0, build_real (TREE_TYPE (arg0), max)));
4814 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
4823 /* If CODE with arguments ARG0 and ARG1 represents a single bit
4824 equality/inequality test, then return a simplified form of
4825 the test using shifts and logical operations. Otherwise return
4826 NULL. TYPE is the desired result type. */
4829 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
4832 /* If this is a TRUTH_NOT_EXPR, it may have a single bit test inside
4834 if (code == TRUTH_NOT_EXPR)
4836 code = TREE_CODE (arg0);
4837 if (code != NE_EXPR && code != EQ_EXPR)
4840 /* Extract the arguments of the EQ/NE. */
4841 arg1 = TREE_OPERAND (arg0, 1);
4842 arg0 = TREE_OPERAND (arg0, 0);
4844 /* This requires us to invert the code. */
4845 code = (code == EQ_EXPR ? NE_EXPR : EQ_EXPR);
4848 /* If this is testing a single bit, we can optimize the test. */
4849 if ((code == NE_EXPR || code == EQ_EXPR)
4850 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
4851 && integer_pow2p (TREE_OPERAND (arg0, 1)))
4853 tree inner = TREE_OPERAND (arg0, 0);
4854 tree type = TREE_TYPE (arg0);
4855 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
4856 enum machine_mode operand_mode = TYPE_MODE (type);
4858 tree signed_type, unsigned_type;
4861 /* If we have (A & C) != 0 where C is the sign bit of A, convert
4862 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
4863 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
4864 if (arg00 != NULL_TREE)
4866 tree stype = (*lang_hooks.types.signed_type) (TREE_TYPE (arg00));
4867 return fold (build (code == EQ_EXPR ? GE_EXPR : LT_EXPR, result_type,
4868 convert (stype, arg00),
4869 convert (stype, integer_zero_node)));
4872 /* At this point, we know that arg0 is not testing the sign bit. */
4873 if (TYPE_PRECISION (type) - 1 == bitnum)
4876 /* Otherwise we have (A & C) != 0 where C is a single bit,
4877 convert that into ((A >> C2) & 1). Where C2 = log2(C).
4878 Similarly for (A & C) == 0. */
4880 /* If INNER is a right shift of a constant and it plus BITNUM does
4881 not overflow, adjust BITNUM and INNER. */
4882 if (TREE_CODE (inner) == RSHIFT_EXPR
4883 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
4884 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
4885 && bitnum < TYPE_PRECISION (type)
4886 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
4887 bitnum - TYPE_PRECISION (type)))
4889 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
4890 inner = TREE_OPERAND (inner, 0);
4893 /* If we are going to be able to omit the AND below, we must do our
4894 operations as unsigned. If we must use the AND, we have a choice.
4895 Normally unsigned is faster, but for some machines signed is. */
4896 #ifdef LOAD_EXTEND_OP
4897 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND ? 0 : 1);
4902 signed_type = (*lang_hooks.types.type_for_mode) (operand_mode, 0);
4903 unsigned_type = (*lang_hooks.types.type_for_mode) (operand_mode, 1);
4906 inner = build (RSHIFT_EXPR, ops_unsigned ? unsigned_type : signed_type,
4907 inner, size_int (bitnum));
4909 if (code == EQ_EXPR)
4910 inner = build (BIT_XOR_EXPR, ops_unsigned ? unsigned_type : signed_type,
4911 inner, integer_one_node);
4913 /* Put the AND last so it can combine with more things. */
4914 inner = build (BIT_AND_EXPR, ops_unsigned ? unsigned_type : signed_type,
4915 inner, integer_one_node);
4917 /* Make sure to return the proper type. */
4918 if (TREE_TYPE (inner) != result_type)
4919 inner = convert (result_type, inner);
4926 /* Perform constant folding and related simplification of EXPR.
4927 The related simplifications include x*1 => x, x*0 => 0, etc.,
4928 and application of the associative law.
4929 NOP_EXPR conversions may be removed freely (as long as we
4930 are careful not to change the C type of the overall expression)
4931 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4932 but we can constant-fold them if they have constant operands. */
4934 #ifdef ENABLE_FOLD_CHECKING
4935 # define fold(x) fold_1 (x)
4936 static tree fold_1 (tree);
4942 tree t = expr, orig_t;
4943 tree t1 = NULL_TREE;
4945 tree type = TREE_TYPE (expr);
4946 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4947 enum tree_code code = TREE_CODE (t);
4948 int kind = TREE_CODE_CLASS (code);
4950 /* WINS will be nonzero when the switch is done
4951 if all operands are constant. */
4954 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4955 Likewise for a SAVE_EXPR that's already been evaluated. */
4956 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0))
4959 /* Return right away if a constant. */
4963 #ifdef MAX_INTEGER_COMPUTATION_MODE
4964 check_max_integer_computation_mode (expr);
4968 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4972 /* Special case for conversion ops that can have fixed point args. */
4973 arg0 = TREE_OPERAND (t, 0);
4975 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4977 STRIP_SIGN_NOPS (arg0);
4979 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4980 subop = TREE_REALPART (arg0);
4984 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4985 && TREE_CODE (subop) != REAL_CST
4987 /* Note that TREE_CONSTANT isn't enough:
4988 static var addresses are constant but we can't
4989 do arithmetic on them. */
4992 else if (IS_EXPR_CODE_CLASS (kind) || kind == 'r')
4994 int len = first_rtl_op (code);
4996 for (i = 0; i < len; i++)
4998 tree op = TREE_OPERAND (t, i);
5002 continue; /* Valid for CALL_EXPR, at least. */
5004 if (kind == '<' || code == RSHIFT_EXPR)
5006 /* Signedness matters here. Perhaps we can refine this
5008 STRIP_SIGN_NOPS (op);
5011 /* Strip any conversions that don't change the mode. */
5014 if (TREE_CODE (op) == COMPLEX_CST)
5015 subop = TREE_REALPART (op);
5019 if (TREE_CODE (subop) != INTEGER_CST
5020 && TREE_CODE (subop) != REAL_CST)
5021 /* Note that TREE_CONSTANT isn't enough:
5022 static var addresses are constant but we can't
5023 do arithmetic on them. */
5033 /* If this is a commutative operation, and ARG0 is a constant, move it
5034 to ARG1 to reduce the number of tests below. */
5035 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
5036 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
5037 || code == BIT_AND_EXPR)
5038 && ((TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) != INTEGER_CST)
5039 || (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) != REAL_CST)))
5041 tem = arg0; arg0 = arg1; arg1 = tem;
5045 TREE_OPERAND (t, 0) = arg0;
5046 TREE_OPERAND (t, 1) = arg1;
5049 /* Now WINS is set as described above,
5050 ARG0 is the first operand of EXPR,
5051 and ARG1 is the second operand (if it has more than one operand).
5053 First check for cases where an arithmetic operation is applied to a
5054 compound, conditional, or comparison operation. Push the arithmetic
5055 operation inside the compound or conditional to see if any folding
5056 can then be done. Convert comparison to conditional for this purpose.
5057 The also optimizes non-constant cases that used to be done in
5060 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
5061 one of the operands is a comparison and the other is a comparison, a
5062 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
5063 code below would make the expression more complex. Change it to a
5064 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
5065 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
5067 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
5068 || code == EQ_EXPR || code == NE_EXPR)
5069 && ((truth_value_p (TREE_CODE (arg0))
5070 && (truth_value_p (TREE_CODE (arg1))
5071 || (TREE_CODE (arg1) == BIT_AND_EXPR
5072 && integer_onep (TREE_OPERAND (arg1, 1)))))
5073 || (truth_value_p (TREE_CODE (arg1))
5074 && (truth_value_p (TREE_CODE (arg0))
5075 || (TREE_CODE (arg0) == BIT_AND_EXPR
5076 && integer_onep (TREE_OPERAND (arg0, 1)))))))
5078 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
5079 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
5083 if (code == EQ_EXPR)
5084 t = invert_truthvalue (t);
5089 if (TREE_CODE_CLASS (code) == '1')
5091 if (TREE_CODE (arg0) == COMPOUND_EXPR)
5092 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5093 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
5094 else if (TREE_CODE (arg0) == COND_EXPR)
5096 tree arg01 = TREE_OPERAND (arg0, 1);
5097 tree arg02 = TREE_OPERAND (arg0, 2);
5098 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
5099 arg01 = fold (build1 (code, type, arg01));
5100 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
5101 arg02 = fold (build1 (code, type, arg02));
5102 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
5105 /* If this was a conversion, and all we did was to move into
5106 inside the COND_EXPR, bring it back out. But leave it if
5107 it is a conversion from integer to integer and the
5108 result precision is no wider than a word since such a
5109 conversion is cheap and may be optimized away by combine,
5110 while it couldn't if it were outside the COND_EXPR. Then return
5111 so we don't get into an infinite recursion loop taking the
5112 conversion out and then back in. */
5114 if ((code == NOP_EXPR || code == CONVERT_EXPR
5115 || code == NON_LVALUE_EXPR)
5116 && TREE_CODE (t) == COND_EXPR
5117 && TREE_CODE (TREE_OPERAND (t, 1)) == code
5118 && TREE_CODE (TREE_OPERAND (t, 2)) == code
5119 && ! VOID_TYPE_P (TREE_OPERAND (t, 1))
5120 && ! VOID_TYPE_P (TREE_OPERAND (t, 2))
5121 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
5122 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
5123 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
5125 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
5126 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
5127 t = build1 (code, type,
5129 TREE_TYPE (TREE_OPERAND
5130 (TREE_OPERAND (t, 1), 0)),
5131 TREE_OPERAND (t, 0),
5132 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
5133 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
5136 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
5137 return fold (build (COND_EXPR, type, arg0,
5138 fold (build1 (code, type, integer_one_node)),
5139 fold (build1 (code, type, integer_zero_node))));
5141 else if (TREE_CODE_CLASS (code) == '<'
5142 && TREE_CODE (arg0) == COMPOUND_EXPR)
5143 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5144 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5145 else if (TREE_CODE_CLASS (code) == '<'
5146 && TREE_CODE (arg1) == COMPOUND_EXPR)
5147 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5148 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
5149 else if (TREE_CODE_CLASS (code) == '2'
5150 || TREE_CODE_CLASS (code) == '<')
5152 if (TREE_CODE (arg1) == COMPOUND_EXPR
5153 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1, 0))
5154 && ! TREE_SIDE_EFFECTS (arg0))
5155 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5156 fold (build (code, type,
5157 arg0, TREE_OPERAND (arg1, 1))));
5158 else if ((TREE_CODE (arg1) == COND_EXPR
5159 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
5160 && TREE_CODE_CLASS (code) != '<'))
5161 && (TREE_CODE (arg0) != COND_EXPR
5162 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5163 && (! TREE_SIDE_EFFECTS (arg0)
5164 || ((*lang_hooks.decls.global_bindings_p) () == 0
5165 && ! CONTAINS_PLACEHOLDER_P (arg0))))
5167 fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
5168 /*cond_first_p=*/0);
5169 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
5170 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5171 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5172 else if ((TREE_CODE (arg0) == COND_EXPR
5173 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
5174 && TREE_CODE_CLASS (code) != '<'))
5175 && (TREE_CODE (arg1) != COND_EXPR
5176 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5177 && (! TREE_SIDE_EFFECTS (arg1)
5178 || ((*lang_hooks.decls.global_bindings_p) () == 0
5179 && ! CONTAINS_PLACEHOLDER_P (arg1))))
5181 fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
5182 /*cond_first_p=*/1);
5196 return fold (DECL_INITIAL (t));
5201 case FIX_TRUNC_EXPR:
5202 /* Other kinds of FIX are not handled properly by fold_convert. */
5204 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
5205 return TREE_OPERAND (t, 0);
5207 /* Handle cases of two conversions in a row. */
5208 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
5209 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
5211 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5212 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
5213 tree final_type = TREE_TYPE (t);
5214 int inside_int = INTEGRAL_TYPE_P (inside_type);
5215 int inside_ptr = POINTER_TYPE_P (inside_type);
5216 int inside_float = FLOAT_TYPE_P (inside_type);
5217 unsigned int inside_prec = TYPE_PRECISION (inside_type);
5218 int inside_unsignedp = TREE_UNSIGNED (inside_type);
5219 int inter_int = INTEGRAL_TYPE_P (inter_type);
5220 int inter_ptr = POINTER_TYPE_P (inter_type);
5221 int inter_float = FLOAT_TYPE_P (inter_type);
5222 unsigned int inter_prec = TYPE_PRECISION (inter_type);
5223 int inter_unsignedp = TREE_UNSIGNED (inter_type);
5224 int final_int = INTEGRAL_TYPE_P (final_type);
5225 int final_ptr = POINTER_TYPE_P (final_type);
5226 int final_float = FLOAT_TYPE_P (final_type);
5227 unsigned int final_prec = TYPE_PRECISION (final_type);
5228 int final_unsignedp = TREE_UNSIGNED (final_type);
5230 /* In addition to the cases of two conversions in a row
5231 handled below, if we are converting something to its own
5232 type via an object of identical or wider precision, neither
5233 conversion is needed. */
5234 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (final_type)
5235 && ((inter_int && final_int) || (inter_float && final_float))
5236 && inter_prec >= final_prec)
5237 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5239 /* Likewise, if the intermediate and final types are either both
5240 float or both integer, we don't need the middle conversion if
5241 it is wider than the final type and doesn't change the signedness
5242 (for integers). Avoid this if the final type is a pointer
5243 since then we sometimes need the inner conversion. Likewise if
5244 the outer has a precision not equal to the size of its mode. */
5245 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
5246 || (inter_float && inside_float))
5247 && inter_prec >= inside_prec
5248 && (inter_float || inter_unsignedp == inside_unsignedp)
5249 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5250 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5252 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5254 /* If we have a sign-extension of a zero-extended value, we can
5255 replace that by a single zero-extension. */
5256 if (inside_int && inter_int && final_int
5257 && inside_prec < inter_prec && inter_prec < final_prec
5258 && inside_unsignedp && !inter_unsignedp)
5259 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5261 /* Two conversions in a row are not needed unless:
5262 - some conversion is floating-point (overstrict for now), or
5263 - the intermediate type is narrower than both initial and
5265 - the intermediate type and innermost type differ in signedness,
5266 and the outermost type is wider than the intermediate, or
5267 - the initial type is a pointer type and the precisions of the
5268 intermediate and final types differ, or
5269 - the final type is a pointer type and the precisions of the
5270 initial and intermediate types differ. */
5271 if (! inside_float && ! inter_float && ! final_float
5272 && (inter_prec > inside_prec || inter_prec > final_prec)
5273 && ! (inside_int && inter_int
5274 && inter_unsignedp != inside_unsignedp
5275 && inter_prec < final_prec)
5276 && ((inter_unsignedp && inter_prec > inside_prec)
5277 == (final_unsignedp && final_prec > inter_prec))
5278 && ! (inside_ptr && inter_prec != final_prec)
5279 && ! (final_ptr && inside_prec != inter_prec)
5280 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5281 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5283 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5286 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5287 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5288 /* Detect assigning a bitfield. */
5289 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5290 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5292 /* Don't leave an assignment inside a conversion
5293 unless assigning a bitfield. */
5294 tree prev = TREE_OPERAND (t, 0);
5297 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5298 /* First do the assignment, then return converted constant. */
5299 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5304 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
5305 constants (if x has signed type, the sign bit cannot be set
5306 in c). This folds extension into the BIT_AND_EXPR. */
5307 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
5308 && TREE_CODE (TREE_TYPE (t)) != BOOLEAN_TYPE
5309 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
5310 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
5312 tree and = TREE_OPERAND (t, 0);
5313 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
5316 if (TREE_UNSIGNED (TREE_TYPE (and))
5317 || (TYPE_PRECISION (TREE_TYPE (t))
5318 <= TYPE_PRECISION (TREE_TYPE (and))))
5320 else if (TYPE_PRECISION (TREE_TYPE (and1))
5321 <= HOST_BITS_PER_WIDE_INT
5322 && host_integerp (and1, 1))
5324 unsigned HOST_WIDE_INT cst;
5326 cst = tree_low_cst (and1, 1);
5327 cst &= (HOST_WIDE_INT) -1
5328 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
5329 change = (cst == 0);
5330 #ifdef LOAD_EXTEND_OP
5332 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
5335 tree uns = (*lang_hooks.types.unsigned_type) (TREE_TYPE (and0));
5336 and0 = convert (uns, and0);
5337 and1 = convert (uns, and1);
5342 return fold (build (BIT_AND_EXPR, TREE_TYPE (t),
5343 convert (TREE_TYPE (t), and0),
5344 convert (TREE_TYPE (t), and1)));
5349 if (TREE_CONSTANT (t) != TREE_CONSTANT (arg0))
5353 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
5357 return fold_convert (t, arg0);
5359 case VIEW_CONVERT_EXPR:
5360 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
5361 return build1 (VIEW_CONVERT_EXPR, type,
5362 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5366 if (TREE_CODE (arg0) == CONSTRUCTOR
5367 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
5369 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5376 if (TREE_CONSTANT (t) != wins)
5380 TREE_CONSTANT (t) = wins;
5387 if (TREE_CODE (arg0) == INTEGER_CST)
5389 unsigned HOST_WIDE_INT low;
5391 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5392 TREE_INT_CST_HIGH (arg0),
5394 t = build_int_2 (low, high);
5395 TREE_TYPE (t) = type;
5397 = (TREE_OVERFLOW (arg0)
5398 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
5399 TREE_CONSTANT_OVERFLOW (t)
5400 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5402 else if (TREE_CODE (arg0) == REAL_CST)
5403 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5405 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5406 return TREE_OPERAND (arg0, 0);
5407 /* Convert -((double)float) into (double)(-float). */
5408 else if (TREE_CODE (arg0) == NOP_EXPR
5409 && TREE_CODE (type) == REAL_TYPE)
5411 tree targ0 = strip_float_extensions (arg0);
5413 return convert (type, build1 (NEGATE_EXPR, TREE_TYPE (targ0), targ0));
5417 /* Convert - (a - b) to (b - a) for non-floating-point. */
5418 else if (TREE_CODE (arg0) == MINUS_EXPR
5419 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
5420 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
5421 TREE_OPERAND (arg0, 0));
5423 /* Convert -f(x) into f(-x) where f is sin, tan or atan. */
5424 switch (builtin_mathfn_code (arg0))
5433 case BUILT_IN_ATANF:
5434 case BUILT_IN_ATANL:
5435 if (negate_expr_p (TREE_VALUE (TREE_OPERAND (arg0, 1))))
5437 tree fndecl, arg, arglist;
5439 fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5440 arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5441 arg = fold (build1 (NEGATE_EXPR, type, arg));
5442 arglist = build_tree_list (NULL_TREE, arg);
5443 return build_function_call_expr (fndecl, arglist);
5455 if (TREE_CODE (arg0) == INTEGER_CST)
5457 /* If the value is unsigned, then the absolute value is
5458 the same as the ordinary value. */
5459 if (TREE_UNSIGNED (type))
5461 /* Similarly, if the value is non-negative. */
5462 else if (INT_CST_LT (integer_minus_one_node, arg0))
5464 /* If the value is negative, then the absolute value is
5468 unsigned HOST_WIDE_INT low;
5470 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5471 TREE_INT_CST_HIGH (arg0),
5473 t = build_int_2 (low, high);
5474 TREE_TYPE (t) = type;
5476 = (TREE_OVERFLOW (arg0)
5477 | force_fit_type (t, overflow));
5478 TREE_CONSTANT_OVERFLOW (t)
5479 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5482 else if (TREE_CODE (arg0) == REAL_CST)
5484 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5485 t = build_real (type,
5486 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5489 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5490 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
5491 /* Convert fabs((double)float) into (double)fabsf(float). */
5492 else if (TREE_CODE (arg0) == NOP_EXPR
5493 && TREE_CODE (type) == REAL_TYPE)
5495 tree targ0 = strip_float_extensions (arg0);
5497 return convert (type, fold (build1 (ABS_EXPR, TREE_TYPE (targ0),
5500 else if (tree_expr_nonnegative_p (arg0))
5505 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5506 return convert (type, arg0);
5507 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5508 return build (COMPLEX_EXPR, type,
5509 TREE_OPERAND (arg0, 0),
5510 negate_expr (TREE_OPERAND (arg0, 1)));
5511 else if (TREE_CODE (arg0) == COMPLEX_CST)
5512 return build_complex (type, TREE_REALPART (arg0),
5513 negate_expr (TREE_IMAGPART (arg0)));
5514 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5515 return fold (build (TREE_CODE (arg0), type,
5516 fold (build1 (CONJ_EXPR, type,
5517 TREE_OPERAND (arg0, 0))),
5518 fold (build1 (CONJ_EXPR,
5519 type, TREE_OPERAND (arg0, 1)))));
5520 else if (TREE_CODE (arg0) == CONJ_EXPR)
5521 return TREE_OPERAND (arg0, 0);
5527 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5528 ~ TREE_INT_CST_HIGH (arg0));
5529 TREE_TYPE (t) = type;
5530 force_fit_type (t, 0);
5531 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5532 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5534 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5535 return TREE_OPERAND (arg0, 0);
5539 /* A + (-B) -> A - B */
5540 if (TREE_CODE (arg1) == NEGATE_EXPR)
5541 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5542 /* (-A) + B -> B - A */
5543 if (TREE_CODE (arg0) == NEGATE_EXPR)
5544 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5545 else if (! FLOAT_TYPE_P (type))
5547 if (integer_zerop (arg1))
5548 return non_lvalue (convert (type, arg0));
5550 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5551 with a constant, and the two constants have no bits in common,
5552 we should treat this as a BIT_IOR_EXPR since this may produce more
5554 if (TREE_CODE (arg0) == BIT_AND_EXPR
5555 && TREE_CODE (arg1) == BIT_AND_EXPR
5556 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5557 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5558 && integer_zerop (const_binop (BIT_AND_EXPR,
5559 TREE_OPERAND (arg0, 1),
5560 TREE_OPERAND (arg1, 1), 0)))
5562 code = BIT_IOR_EXPR;
5566 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5567 (plus (plus (mult) (mult)) (foo)) so that we can
5568 take advantage of the factoring cases below. */
5569 if ((TREE_CODE (arg0) == PLUS_EXPR
5570 && TREE_CODE (arg1) == MULT_EXPR)
5571 || (TREE_CODE (arg1) == PLUS_EXPR
5572 && TREE_CODE (arg0) == MULT_EXPR))
5574 tree parg0, parg1, parg, marg;
5576 if (TREE_CODE (arg0) == PLUS_EXPR)
5577 parg = arg0, marg = arg1;
5579 parg = arg1, marg = arg0;
5580 parg0 = TREE_OPERAND (parg, 0);
5581 parg1 = TREE_OPERAND (parg, 1);
5585 if (TREE_CODE (parg0) == MULT_EXPR
5586 && TREE_CODE (parg1) != MULT_EXPR)
5587 return fold (build (PLUS_EXPR, type,
5588 fold (build (PLUS_EXPR, type,
5589 convert (type, parg0),
5590 convert (type, marg))),
5591 convert (type, parg1)));
5592 if (TREE_CODE (parg0) != MULT_EXPR
5593 && TREE_CODE (parg1) == MULT_EXPR)
5594 return fold (build (PLUS_EXPR, type,
5595 fold (build (PLUS_EXPR, type,
5596 convert (type, parg1),
5597 convert (type, marg))),
5598 convert (type, parg0)));
5601 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5603 tree arg00, arg01, arg10, arg11;
5604 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5606 /* (A * C) + (B * C) -> (A+B) * C.
5607 We are most concerned about the case where C is a constant,
5608 but other combinations show up during loop reduction. Since
5609 it is not difficult, try all four possibilities. */
5611 arg00 = TREE_OPERAND (arg0, 0);
5612 arg01 = TREE_OPERAND (arg0, 1);
5613 arg10 = TREE_OPERAND (arg1, 0);
5614 arg11 = TREE_OPERAND (arg1, 1);
5617 if (operand_equal_p (arg01, arg11, 0))
5618 same = arg01, alt0 = arg00, alt1 = arg10;
5619 else if (operand_equal_p (arg00, arg10, 0))
5620 same = arg00, alt0 = arg01, alt1 = arg11;
5621 else if (operand_equal_p (arg00, arg11, 0))
5622 same = arg00, alt0 = arg01, alt1 = arg10;
5623 else if (operand_equal_p (arg01, arg10, 0))
5624 same = arg01, alt0 = arg00, alt1 = arg11;
5626 /* No identical multiplicands; see if we can find a common
5627 power-of-two factor in non-power-of-two multiplies. This
5628 can help in multi-dimensional array access. */
5629 else if (TREE_CODE (arg01) == INTEGER_CST
5630 && TREE_CODE (arg11) == INTEGER_CST
5631 && TREE_INT_CST_HIGH (arg01) == 0
5632 && TREE_INT_CST_HIGH (arg11) == 0)
5634 HOST_WIDE_INT int01, int11, tmp;
5635 int01 = TREE_INT_CST_LOW (arg01);
5636 int11 = TREE_INT_CST_LOW (arg11);
5638 /* Move min of absolute values to int11. */
5639 if ((int01 >= 0 ? int01 : -int01)
5640 < (int11 >= 0 ? int11 : -int11))
5642 tmp = int01, int01 = int11, int11 = tmp;
5643 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5644 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5647 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5649 alt0 = fold (build (MULT_EXPR, type, arg00,
5650 build_int_2 (int01 / int11, 0)));
5657 return fold (build (MULT_EXPR, type,
5658 fold (build (PLUS_EXPR, type, alt0, alt1)),
5663 /* See if ARG1 is zero and X + ARG1 reduces to X. */
5664 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
5665 return non_lvalue (convert (type, arg0));
5667 /* Likewise if the operands are reversed. */
5668 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
5669 return non_lvalue (convert (type, arg1));
5672 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5673 is a rotate of A by C1 bits. */
5674 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5675 is a rotate of A by B bits. */
5677 enum tree_code code0, code1;
5678 code0 = TREE_CODE (arg0);
5679 code1 = TREE_CODE (arg1);
5680 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5681 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5682 && operand_equal_p (TREE_OPERAND (arg0, 0),
5683 TREE_OPERAND (arg1, 0), 0)
5684 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5686 tree tree01, tree11;
5687 enum tree_code code01, code11;
5689 tree01 = TREE_OPERAND (arg0, 1);
5690 tree11 = TREE_OPERAND (arg1, 1);
5691 STRIP_NOPS (tree01);
5692 STRIP_NOPS (tree11);
5693 code01 = TREE_CODE (tree01);
5694 code11 = TREE_CODE (tree11);
5695 if (code01 == INTEGER_CST
5696 && code11 == INTEGER_CST
5697 && TREE_INT_CST_HIGH (tree01) == 0
5698 && TREE_INT_CST_HIGH (tree11) == 0
5699 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5700 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5701 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5702 code0 == LSHIFT_EXPR ? tree01 : tree11);
5703 else if (code11 == MINUS_EXPR)
5705 tree tree110, tree111;
5706 tree110 = TREE_OPERAND (tree11, 0);
5707 tree111 = TREE_OPERAND (tree11, 1);
5708 STRIP_NOPS (tree110);
5709 STRIP_NOPS (tree111);
5710 if (TREE_CODE (tree110) == INTEGER_CST
5711 && 0 == compare_tree_int (tree110,
5713 (TREE_TYPE (TREE_OPERAND
5715 && operand_equal_p (tree01, tree111, 0))
5716 return build ((code0 == LSHIFT_EXPR
5719 type, TREE_OPERAND (arg0, 0), tree01);
5721 else if (code01 == MINUS_EXPR)
5723 tree tree010, tree011;
5724 tree010 = TREE_OPERAND (tree01, 0);
5725 tree011 = TREE_OPERAND (tree01, 1);
5726 STRIP_NOPS (tree010);
5727 STRIP_NOPS (tree011);
5728 if (TREE_CODE (tree010) == INTEGER_CST
5729 && 0 == compare_tree_int (tree010,
5731 (TREE_TYPE (TREE_OPERAND
5733 && operand_equal_p (tree11, tree011, 0))
5734 return build ((code0 != LSHIFT_EXPR
5737 type, TREE_OPERAND (arg0, 0), tree11);
5743 /* In most languages, can't associate operations on floats through
5744 parentheses. Rather than remember where the parentheses were, we
5745 don't associate floats at all. It shouldn't matter much. However,
5746 associating multiplications is only very slightly inaccurate, so do
5747 that if -funsafe-math-optimizations is specified. */
5750 && (! FLOAT_TYPE_P (type)
5751 || (flag_unsafe_math_optimizations && code == MULT_EXPR)))
5753 tree var0, con0, lit0, minus_lit0;
5754 tree var1, con1, lit1, minus_lit1;
5756 /* Split both trees into variables, constants, and literals. Then
5757 associate each group together, the constants with literals,
5758 then the result with variables. This increases the chances of
5759 literals being recombined later and of generating relocatable
5760 expressions for the sum of a constant and literal. */
5761 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
5762 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
5763 code == MINUS_EXPR);
5765 /* Only do something if we found more than two objects. Otherwise,
5766 nothing has changed and we risk infinite recursion. */
5767 if (2 < ((var0 != 0) + (var1 != 0)
5768 + (con0 != 0) + (con1 != 0)
5769 + (lit0 != 0) + (lit1 != 0)
5770 + (minus_lit0 != 0) + (minus_lit1 != 0)))
5772 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
5773 if (code == MINUS_EXPR)
5776 var0 = associate_trees (var0, var1, code, type);
5777 con0 = associate_trees (con0, con1, code, type);
5778 lit0 = associate_trees (lit0, lit1, code, type);
5779 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
5781 /* Preserve the MINUS_EXPR if the negative part of the literal is
5782 greater than the positive part. Otherwise, the multiplicative
5783 folding code (i.e extract_muldiv) may be fooled in case
5784 unsigned constants are subtracted, like in the following
5785 example: ((X*2 + 4) - 8U)/2. */
5786 if (minus_lit0 && lit0)
5788 if (tree_int_cst_lt (lit0, minus_lit0))
5790 minus_lit0 = associate_trees (minus_lit0, lit0,
5796 lit0 = associate_trees (lit0, minus_lit0,
5804 return convert (type, associate_trees (var0, minus_lit0,
5808 con0 = associate_trees (con0, minus_lit0,
5810 return convert (type, associate_trees (var0, con0,
5815 con0 = associate_trees (con0, lit0, code, type);
5816 return convert (type, associate_trees (var0, con0, code, type));
5822 t1 = const_binop (code, arg0, arg1, 0);
5823 if (t1 != NULL_TREE)
5825 /* The return value should always have
5826 the same type as the original expression. */
5827 if (TREE_TYPE (t1) != TREE_TYPE (t))
5828 t1 = convert (TREE_TYPE (t), t1);
5835 /* A - (-B) -> A + B */
5836 if (TREE_CODE (arg1) == NEGATE_EXPR)
5837 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5838 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
5839 if (TREE_CODE (arg0) == NEGATE_EXPR
5840 && (FLOAT_TYPE_P (type)
5841 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
5842 && negate_expr_p (arg1)
5843 && (! TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
5844 && (! TREE_SIDE_EFFECTS (arg1) || TREE_CONSTANT (arg0)))
5845 return fold (build (MINUS_EXPR, type, negate_expr (arg1),
5846 TREE_OPERAND (arg0, 0)));
5848 if (! FLOAT_TYPE_P (type))
5850 if (! wins && integer_zerop (arg0))
5851 return negate_expr (convert (type, arg1));
5852 if (integer_zerop (arg1))
5853 return non_lvalue (convert (type, arg0));
5855 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5856 about the case where C is a constant, just try one of the
5857 four possibilities. */
5859 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5860 && operand_equal_p (TREE_OPERAND (arg0, 1),
5861 TREE_OPERAND (arg1, 1), 0))
5862 return fold (build (MULT_EXPR, type,
5863 fold (build (MINUS_EXPR, type,
5864 TREE_OPERAND (arg0, 0),
5865 TREE_OPERAND (arg1, 0))),
5866 TREE_OPERAND (arg0, 1)));
5868 /* Fold A - (A & B) into ~B & A. */
5869 if (!TREE_SIDE_EFFECTS (arg0)
5870 && TREE_CODE (arg1) == BIT_AND_EXPR)
5872 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
5873 return fold (build (BIT_AND_EXPR, type,
5874 fold (build1 (BIT_NOT_EXPR, type,
5875 TREE_OPERAND (arg1, 0))),
5877 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
5878 return fold (build (BIT_AND_EXPR, type,
5879 fold (build1 (BIT_NOT_EXPR, type,
5880 TREE_OPERAND (arg1, 1))),
5885 /* See if ARG1 is zero and X - ARG1 reduces to X. */
5886 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
5887 return non_lvalue (convert (type, arg0));
5889 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
5890 ARG0 is zero and X + ARG0 reduces to X, since that would mean
5891 (-ARG1 + ARG0) reduces to -ARG1. */
5892 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
5893 return negate_expr (convert (type, arg1));
5895 /* Fold &x - &x. This can happen from &x.foo - &x.
5896 This is unsafe for certain floats even in non-IEEE formats.
5897 In IEEE, it is unsafe because it does wrong for NaNs.
5898 Also note that operand_equal_p is always false if an operand
5901 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
5902 && operand_equal_p (arg0, arg1, 0))
5903 return convert (type, integer_zero_node);
5908 /* (-A) * (-B) -> A * B */
5909 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5910 return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
5911 TREE_OPERAND (arg1, 0)));
5913 if (! FLOAT_TYPE_P (type))
5915 if (integer_zerop (arg1))
5916 return omit_one_operand (type, arg1, arg0);
5917 if (integer_onep (arg1))
5918 return non_lvalue (convert (type, arg0));
5920 /* (a * (1 << b)) is (a << b) */
5921 if (TREE_CODE (arg1) == LSHIFT_EXPR
5922 && integer_onep (TREE_OPERAND (arg1, 0)))
5923 return fold (build (LSHIFT_EXPR, type, arg0,
5924 TREE_OPERAND (arg1, 1)));
5925 if (TREE_CODE (arg0) == LSHIFT_EXPR
5926 && integer_onep (TREE_OPERAND (arg0, 0)))
5927 return fold (build (LSHIFT_EXPR, type, arg1,
5928 TREE_OPERAND (arg0, 1)));
5930 if (TREE_CODE (arg1) == INTEGER_CST
5931 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
5932 convert (type, arg1),
5934 return convert (type, tem);
5939 /* Maybe fold x * 0 to 0. The expressions aren't the same
5940 when x is NaN, since x * 0 is also NaN. Nor are they the
5941 same in modes with signed zeros, since multiplying a
5942 negative value by 0 gives -0, not +0. */
5943 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
5944 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
5945 && real_zerop (arg1))
5946 return omit_one_operand (type, arg1, arg0);
5947 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
5948 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
5949 && real_onep (arg1))
5950 return non_lvalue (convert (type, arg0));
5952 /* Transform x * -1.0 into -x. */
5953 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
5954 && real_minus_onep (arg1))
5955 return fold (build1 (NEGATE_EXPR, type, arg0));
5958 if (! wins && real_twop (arg1)
5959 && (*lang_hooks.decls.global_bindings_p) () == 0
5960 && ! CONTAINS_PLACEHOLDER_P (arg0))
5962 tree arg = save_expr (arg0);
5963 return fold (build (PLUS_EXPR, type, arg, arg));
5966 if (flag_unsafe_math_optimizations)
5968 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
5969 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
5971 /* Optimizations of sqrt(...)*sqrt(...). */
5972 if ((fcode0 == BUILT_IN_SQRT && fcode1 == BUILT_IN_SQRT)
5973 || (fcode0 == BUILT_IN_SQRTF && fcode1 == BUILT_IN_SQRTF)
5974 || (fcode0 == BUILT_IN_SQRTL && fcode1 == BUILT_IN_SQRTL))
5976 tree sqrtfn, arg, arglist;
5977 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
5978 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
5980 /* Optimize sqrt(x)*sqrt(x) as x. */
5981 if (operand_equal_p (arg00, arg10, 0)
5982 && ! HONOR_SNANS (TYPE_MODE (type)))
5985 /* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */
5986 sqrtfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5987 arg = fold (build (MULT_EXPR, type, arg00, arg10));
5988 arglist = build_tree_list (NULL_TREE, arg);
5989 return build_function_call_expr (sqrtfn, arglist);
5992 /* Optimize exp(x)*exp(y) as exp(x+y). */
5993 if ((fcode0 == BUILT_IN_EXP && fcode1 == BUILT_IN_EXP)
5994 || (fcode0 == BUILT_IN_EXPF && fcode1 == BUILT_IN_EXPF)
5995 || (fcode0 == BUILT_IN_EXPL && fcode1 == BUILT_IN_EXPL))
5997 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5998 tree arg = build (PLUS_EXPR, type,
5999 TREE_VALUE (TREE_OPERAND (arg0, 1)),
6000 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6001 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6002 return build_function_call_expr (expfn, arglist);
6005 /* Optimizations of pow(...)*pow(...). */
6006 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
6007 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
6008 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
6010 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6011 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
6013 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6014 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
6017 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
6018 if (operand_equal_p (arg01, arg11, 0))
6020 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6021 tree arg = build (MULT_EXPR, type, arg00, arg10);
6022 tree arglist = tree_cons (NULL_TREE, fold (arg),
6023 build_tree_list (NULL_TREE,
6025 return build_function_call_expr (powfn, arglist);
6028 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
6029 if (operand_equal_p (arg00, arg10, 0))
6031 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6032 tree arg = fold (build (PLUS_EXPR, type, arg01, arg11));
6033 tree arglist = tree_cons (NULL_TREE, arg00,
6034 build_tree_list (NULL_TREE,
6036 return build_function_call_expr (powfn, arglist);
6040 /* Optimize tan(x)*cos(x) as sin(x). */
6041 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
6042 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
6043 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
6044 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
6045 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
6046 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
6047 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6048 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6056 sinfn = implicit_built_in_decls[BUILT_IN_SIN];
6060 sinfn = implicit_built_in_decls[BUILT_IN_SINF];
6064 sinfn = implicit_built_in_decls[BUILT_IN_SINL];
6070 if (sinfn != NULL_TREE)
6071 return build_function_call_expr (sinfn,
6072 TREE_OPERAND (arg0, 1));
6080 if (integer_all_onesp (arg1))
6081 return omit_one_operand (type, arg1, arg0);
6082 if (integer_zerop (arg1))
6083 return non_lvalue (convert (type, arg0));
6084 t1 = distribute_bit_expr (code, type, arg0, arg1);
6085 if (t1 != NULL_TREE)
6088 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
6090 This results in more efficient code for machines without a NAND
6091 instruction. Combine will canonicalize to the first form
6092 which will allow use of NAND instructions provided by the
6093 backend if they exist. */
6094 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6095 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6097 return fold (build1 (BIT_NOT_EXPR, type,
6098 build (BIT_AND_EXPR, type,
6099 TREE_OPERAND (arg0, 0),
6100 TREE_OPERAND (arg1, 0))));
6103 /* See if this can be simplified into a rotate first. If that
6104 is unsuccessful continue in the association code. */
6108 if (integer_zerop (arg1))
6109 return non_lvalue (convert (type, arg0));
6110 if (integer_all_onesp (arg1))
6111 return fold (build1 (BIT_NOT_EXPR, type, arg0));
6113 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
6114 with a constant, and the two constants have no bits in common,
6115 we should treat this as a BIT_IOR_EXPR since this may produce more
6117 if (TREE_CODE (arg0) == BIT_AND_EXPR
6118 && TREE_CODE (arg1) == BIT_AND_EXPR
6119 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6120 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
6121 && integer_zerop (const_binop (BIT_AND_EXPR,
6122 TREE_OPERAND (arg0, 1),
6123 TREE_OPERAND (arg1, 1), 0)))
6125 code = BIT_IOR_EXPR;
6129 /* See if this can be simplified into a rotate first. If that
6130 is unsuccessful continue in the association code. */
6135 if (integer_all_onesp (arg1))
6136 return non_lvalue (convert (type, arg0));
6137 if (integer_zerop (arg1))
6138 return omit_one_operand (type, arg1, arg0);
6139 t1 = distribute_bit_expr (code, type, arg0, arg1);
6140 if (t1 != NULL_TREE)
6142 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
6143 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
6144 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6147 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
6149 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
6150 && (~TREE_INT_CST_LOW (arg1)
6151 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
6152 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
6155 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
6157 This results in more efficient code for machines without a NOR
6158 instruction. Combine will canonicalize to the first form
6159 which will allow use of NOR instructions provided by the
6160 backend if they exist. */
6161 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6162 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6164 return fold (build1 (BIT_NOT_EXPR, type,
6165 build (BIT_IOR_EXPR, type,
6166 TREE_OPERAND (arg0, 0),
6167 TREE_OPERAND (arg1, 0))));
6172 case BIT_ANDTC_EXPR:
6173 if (integer_all_onesp (arg0))
6174 return non_lvalue (convert (type, arg1));
6175 if (integer_zerop (arg0))
6176 return omit_one_operand (type, arg0, arg1);
6177 if (TREE_CODE (arg1) == INTEGER_CST)
6179 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
6180 code = BIT_AND_EXPR;
6186 /* Don't touch a floating-point divide by zero unless the mode
6187 of the constant can represent infinity. */
6188 if (TREE_CODE (arg1) == REAL_CST
6189 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
6190 && real_zerop (arg1))
6193 /* (-A) / (-B) -> A / B */
6194 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
6195 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
6196 TREE_OPERAND (arg1, 0)));
6198 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
6199 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6200 && real_onep (arg1))
6201 return non_lvalue (convert (type, arg0));
6203 /* If ARG1 is a constant, we can convert this to a multiply by the
6204 reciprocal. This does not have the same rounding properties,
6205 so only do this if -funsafe-math-optimizations. We can actually
6206 always safely do it if ARG1 is a power of two, but it's hard to
6207 tell if it is or not in a portable manner. */
6208 if (TREE_CODE (arg1) == REAL_CST)
6210 if (flag_unsafe_math_optimizations
6211 && 0 != (tem = const_binop (code, build_real (type, dconst1),
6213 return fold (build (MULT_EXPR, type, arg0, tem));
6214 /* Find the reciprocal if optimizing and the result is exact. */
6218 r = TREE_REAL_CST (arg1);
6219 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
6221 tem = build_real (type, r);
6222 return fold (build (MULT_EXPR, type, arg0, tem));
6226 /* Convert A/B/C to A/(B*C). */
6227 if (flag_unsafe_math_optimizations
6228 && TREE_CODE (arg0) == RDIV_EXPR)
6230 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
6231 build (MULT_EXPR, type, TREE_OPERAND (arg0, 1),
6234 /* Convert A/(B/C) to (A/B)*C. */
6235 if (flag_unsafe_math_optimizations
6236 && TREE_CODE (arg1) == RDIV_EXPR)
6238 return fold (build (MULT_EXPR, type,
6239 build (RDIV_EXPR, type, arg0,
6240 TREE_OPERAND (arg1, 0)),
6241 TREE_OPERAND (arg1, 1)));
6244 if (flag_unsafe_math_optimizations)
6246 enum built_in_function fcode = builtin_mathfn_code (arg1);
6247 /* Optimize x/exp(y) into x*exp(-y). */
6248 if (fcode == BUILT_IN_EXP
6249 || fcode == BUILT_IN_EXPF
6250 || fcode == BUILT_IN_EXPL)
6252 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6253 tree arg = build1 (NEGATE_EXPR, type,
6254 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6255 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6256 arg1 = build_function_call_expr (expfn, arglist);
6257 return fold (build (MULT_EXPR, type, arg0, arg1));
6260 /* Optimize x/pow(y,z) into x*pow(y,-z). */
6261 if (fcode == BUILT_IN_POW
6262 || fcode == BUILT_IN_POWF
6263 || fcode == BUILT_IN_POWL)
6265 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6266 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6267 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
6268 tree neg11 = fold (build1 (NEGATE_EXPR, type, arg11));
6269 tree arglist = tree_cons(NULL_TREE, arg10,
6270 build_tree_list (NULL_TREE, neg11));
6271 arg1 = build_function_call_expr (powfn, arglist);
6272 return fold (build (MULT_EXPR, type, arg0, arg1));
6276 if (flag_unsafe_math_optimizations)
6278 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
6279 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
6281 /* Optimize sin(x)/cos(x) as tan(x). */
6282 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
6283 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
6284 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
6285 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6286 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6290 if (fcode0 == BUILT_IN_SIN)
6291 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6292 else if (fcode0 == BUILT_IN_SINF)
6293 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6294 else if (fcode0 == BUILT_IN_SINL)
6295 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6299 if (tanfn != NULL_TREE)
6300 return build_function_call_expr (tanfn,
6301 TREE_OPERAND (arg0, 1));
6304 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
6305 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
6306 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
6307 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
6308 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6309 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6313 if (fcode0 == BUILT_IN_COS)
6314 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6315 else if (fcode0 == BUILT_IN_COSF)
6316 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6317 else if (fcode0 == BUILT_IN_COSL)
6318 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6322 if (tanfn != NULL_TREE)
6324 tree tmp = TREE_OPERAND (arg0, 1);
6325 tmp = build_function_call_expr (tanfn, tmp);
6326 return fold (build (RDIV_EXPR, type,
6327 build_real (type, dconst1),
6334 case TRUNC_DIV_EXPR:
6335 case ROUND_DIV_EXPR:
6336 case FLOOR_DIV_EXPR:
6338 case EXACT_DIV_EXPR:
6339 if (integer_onep (arg1))
6340 return non_lvalue (convert (type, arg0));
6341 if (integer_zerop (arg1))
6344 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
6345 operation, EXACT_DIV_EXPR.
6347 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
6348 At one time others generated faster code, it's not clear if they do
6349 after the last round to changes to the DIV code in expmed.c. */
6350 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
6351 && multiple_of_p (type, arg0, arg1))
6352 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
6354 if (TREE_CODE (arg1) == INTEGER_CST
6355 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6357 return convert (type, tem);
6362 case FLOOR_MOD_EXPR:
6363 case ROUND_MOD_EXPR:
6364 case TRUNC_MOD_EXPR:
6365 if (integer_onep (arg1))
6366 return omit_one_operand (type, integer_zero_node, arg0);
6367 if (integer_zerop (arg1))
6370 if (TREE_CODE (arg1) == INTEGER_CST
6371 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6373 return convert (type, tem);
6379 if (integer_all_onesp (arg0))
6380 return omit_one_operand (type, arg0, arg1);
6384 /* Optimize -1 >> x for arithmetic right shifts. */
6385 if (integer_all_onesp (arg0) && ! TREE_UNSIGNED (type))
6386 return omit_one_operand (type, arg0, arg1);
6387 /* ... fall through ... */
6391 if (integer_zerop (arg1))
6392 return non_lvalue (convert (type, arg0));
6393 if (integer_zerop (arg0))
6394 return omit_one_operand (type, arg0, arg1);
6396 /* Since negative shift count is not well-defined,
6397 don't try to compute it in the compiler. */
6398 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
6400 /* Rewrite an LROTATE_EXPR by a constant into an
6401 RROTATE_EXPR by a new constant. */
6402 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
6406 TREE_SET_CODE (t, RROTATE_EXPR);
6407 code = RROTATE_EXPR;
6408 TREE_OPERAND (t, 1) = arg1
6411 convert (TREE_TYPE (arg1),
6412 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
6414 if (tree_int_cst_sgn (arg1) < 0)
6418 /* If we have a rotate of a bit operation with the rotate count and
6419 the second operand of the bit operation both constant,
6420 permute the two operations. */
6421 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6422 && (TREE_CODE (arg0) == BIT_AND_EXPR
6423 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
6424 || TREE_CODE (arg0) == BIT_IOR_EXPR
6425 || TREE_CODE (arg0) == BIT_XOR_EXPR)
6426 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6427 return fold (build (TREE_CODE (arg0), type,
6428 fold (build (code, type,
6429 TREE_OPERAND (arg0, 0), arg1)),
6430 fold (build (code, type,
6431 TREE_OPERAND (arg0, 1), arg1))));
6433 /* Two consecutive rotates adding up to the width of the mode can
6435 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6436 && TREE_CODE (arg0) == RROTATE_EXPR
6437 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6438 && TREE_INT_CST_HIGH (arg1) == 0
6439 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
6440 && ((TREE_INT_CST_LOW (arg1)
6441 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
6442 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
6443 return TREE_OPERAND (arg0, 0);
6448 if (operand_equal_p (arg0, arg1, 0))
6449 return omit_one_operand (type, arg0, arg1);
6450 if (INTEGRAL_TYPE_P (type)
6451 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
6452 return omit_one_operand (type, arg1, arg0);
6456 if (operand_equal_p (arg0, arg1, 0))
6457 return omit_one_operand (type, arg0, arg1);
6458 if (INTEGRAL_TYPE_P (type)
6459 && TYPE_MAX_VALUE (type)
6460 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
6461 return omit_one_operand (type, arg1, arg0);
6464 case TRUTH_NOT_EXPR:
6465 /* Note that the operand of this must be an int
6466 and its values must be 0 or 1.
6467 ("true" is a fixed value perhaps depending on the language,
6468 but we don't handle values other than 1 correctly yet.) */
6469 tem = invert_truthvalue (arg0);
6470 /* Avoid infinite recursion. */
6471 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
6473 tem = fold_single_bit_test (code, arg0, arg1, type);
6478 return convert (type, tem);
6480 case TRUTH_ANDIF_EXPR:
6481 /* Note that the operands of this must be ints
6482 and their values must be 0 or 1.
6483 ("true" is a fixed value perhaps depending on the language.) */
6484 /* If first arg is constant zero, return it. */
6485 if (integer_zerop (arg0))
6486 return convert (type, arg0);
6487 case TRUTH_AND_EXPR:
6488 /* If either arg is constant true, drop it. */
6489 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6490 return non_lvalue (convert (type, arg1));
6491 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
6492 /* Preserve sequence points. */
6493 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6494 return non_lvalue (convert (type, arg0));
6495 /* If second arg is constant zero, result is zero, but first arg
6496 must be evaluated. */
6497 if (integer_zerop (arg1))
6498 return omit_one_operand (type, arg1, arg0);
6499 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
6500 case will be handled here. */
6501 if (integer_zerop (arg0))
6502 return omit_one_operand (type, arg0, arg1);
6505 /* We only do these simplifications if we are optimizing. */
6509 /* Check for things like (A || B) && (A || C). We can convert this
6510 to A || (B && C). Note that either operator can be any of the four
6511 truth and/or operations and the transformation will still be
6512 valid. Also note that we only care about order for the
6513 ANDIF and ORIF operators. If B contains side effects, this
6514 might change the truth-value of A. */
6515 if (TREE_CODE (arg0) == TREE_CODE (arg1)
6516 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
6517 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
6518 || TREE_CODE (arg0) == TRUTH_AND_EXPR
6519 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
6520 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
6522 tree a00 = TREE_OPERAND (arg0, 0);
6523 tree a01 = TREE_OPERAND (arg0, 1);
6524 tree a10 = TREE_OPERAND (arg1, 0);
6525 tree a11 = TREE_OPERAND (arg1, 1);
6526 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
6527 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
6528 && (code == TRUTH_AND_EXPR
6529 || code == TRUTH_OR_EXPR));
6531 if (operand_equal_p (a00, a10, 0))
6532 return fold (build (TREE_CODE (arg0), type, a00,
6533 fold (build (code, type, a01, a11))));
6534 else if (commutative && operand_equal_p (a00, a11, 0))
6535 return fold (build (TREE_CODE (arg0), type, a00,
6536 fold (build (code, type, a01, a10))));
6537 else if (commutative && operand_equal_p (a01, a10, 0))
6538 return fold (build (TREE_CODE (arg0), type, a01,
6539 fold (build (code, type, a00, a11))));
6541 /* This case if tricky because we must either have commutative
6542 operators or else A10 must not have side-effects. */
6544 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
6545 && operand_equal_p (a01, a11, 0))
6546 return fold (build (TREE_CODE (arg0), type,
6547 fold (build (code, type, a00, a10)),
6551 /* See if we can build a range comparison. */
6552 if (0 != (tem = fold_range_test (t)))
6555 /* Check for the possibility of merging component references. If our
6556 lhs is another similar operation, try to merge its rhs with our
6557 rhs. Then try to merge our lhs and rhs. */
6558 if (TREE_CODE (arg0) == code
6559 && 0 != (tem = fold_truthop (code, type,
6560 TREE_OPERAND (arg0, 1), arg1)))
6561 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6563 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
6568 case TRUTH_ORIF_EXPR:
6569 /* Note that the operands of this must be ints
6570 and their values must be 0 or true.
6571 ("true" is a fixed value perhaps depending on the language.) */
6572 /* If first arg is constant true, return it. */
6573 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6574 return convert (type, arg0);
6576 /* If either arg is constant zero, drop it. */
6577 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
6578 return non_lvalue (convert (type, arg1));
6579 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
6580 /* Preserve sequence points. */
6581 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6582 return non_lvalue (convert (type, arg0));
6583 /* If second arg is constant true, result is true, but we must
6584 evaluate first arg. */
6585 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
6586 return omit_one_operand (type, arg1, arg0);
6587 /* Likewise for first arg, but note this only occurs here for
6589 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6590 return omit_one_operand (type, arg0, arg1);
6593 case TRUTH_XOR_EXPR:
6594 /* If either arg is constant zero, drop it. */
6595 if (integer_zerop (arg0))
6596 return non_lvalue (convert (type, arg1));
6597 if (integer_zerop (arg1))
6598 return non_lvalue (convert (type, arg0));
6599 /* If either arg is constant true, this is a logical inversion. */
6600 if (integer_onep (arg0))
6601 return non_lvalue (convert (type, invert_truthvalue (arg1)));
6602 if (integer_onep (arg1))
6603 return non_lvalue (convert (type, invert_truthvalue (arg0)));
6612 /* If one arg is a real or integer constant, put it last. */
6613 if ((TREE_CODE (arg0) == INTEGER_CST
6614 && TREE_CODE (arg1) != INTEGER_CST)
6615 || (TREE_CODE (arg0) == REAL_CST
6616 && TREE_CODE (arg0) != REAL_CST))
6620 TREE_OPERAND (t, 0) = arg1;
6621 TREE_OPERAND (t, 1) = arg0;
6622 arg0 = TREE_OPERAND (t, 0);
6623 arg1 = TREE_OPERAND (t, 1);
6624 code = swap_tree_comparison (code);
6625 TREE_SET_CODE (t, code);
6628 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
6630 tree targ0 = strip_float_extensions (arg0);
6631 tree targ1 = strip_float_extensions (arg1);
6632 tree newtype = TREE_TYPE (targ0);
6634 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
6635 newtype = TREE_TYPE (targ1);
6637 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
6638 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
6639 return fold (build (code, type, convert (newtype, targ0),
6640 convert (newtype, targ1)));
6642 /* (-a) CMP (-b) -> b CMP a */
6643 if (TREE_CODE (arg0) == NEGATE_EXPR
6644 && TREE_CODE (arg1) == NEGATE_EXPR)
6645 return fold (build (code, type, TREE_OPERAND (arg1, 0),
6646 TREE_OPERAND (arg0, 0)));
6648 if (TREE_CODE (arg1) == REAL_CST)
6650 REAL_VALUE_TYPE cst;
6651 cst = TREE_REAL_CST (arg1);
6653 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6654 if (TREE_CODE (arg0) == NEGATE_EXPR)
6656 fold (build (swap_tree_comparison (code), type,
6657 TREE_OPERAND (arg0, 0),
6658 build_real (TREE_TYPE (arg1),
6659 REAL_VALUE_NEGATE (cst))));
6661 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6662 /* a CMP (-0) -> a CMP 0 */
6663 if (REAL_VALUE_MINUS_ZERO (cst))
6664 return fold (build (code, type, arg0,
6665 build_real (TREE_TYPE (arg1), dconst0)));
6667 /* x != NaN is always true, other ops are always false. */
6668 if (REAL_VALUE_ISNAN (cst)
6669 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
6671 t = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
6672 return omit_one_operand (type, convert (type, t), arg0);
6675 /* Fold comparisons against infinity. */
6676 if (REAL_VALUE_ISINF (cst))
6678 tem = fold_inf_compare (code, type, arg0, arg1);
6679 if (tem != NULL_TREE)
6684 /* If this is a comparison of a real constant with a PLUS_EXPR
6685 or a MINUS_EXPR of a real constant, we can convert it into a
6686 comparison with a revised real constant as long as no overflow
6687 occurs when unsafe_math_optimizations are enabled. */
6688 if (flag_unsafe_math_optimizations
6689 && TREE_CODE (arg1) == REAL_CST
6690 && (TREE_CODE (arg0) == PLUS_EXPR
6691 || TREE_CODE (arg0) == MINUS_EXPR)
6692 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6693 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6694 ? MINUS_EXPR : PLUS_EXPR,
6695 arg1, TREE_OPERAND (arg0, 1), 0))
6696 && ! TREE_CONSTANT_OVERFLOW (tem))
6697 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6699 /* Likewise, we can simplify a comparison of a real constant with
6700 a MINUS_EXPR whose first operand is also a real constant, i.e.
6701 (c1 - x) < c2 becomes x > c1-c2. */
6702 if (flag_unsafe_math_optimizations
6703 && TREE_CODE (arg1) == REAL_CST
6704 && TREE_CODE (arg0) == MINUS_EXPR
6705 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
6706 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
6708 && ! TREE_CONSTANT_OVERFLOW (tem))
6709 return fold (build (swap_tree_comparison (code), type,
6710 TREE_OPERAND (arg0, 1), tem));
6712 /* Fold comparisons against built-in math functions. */
6713 if (TREE_CODE (arg1) == REAL_CST
6714 && flag_unsafe_math_optimizations
6715 && ! flag_errno_math)
6717 enum built_in_function fcode = builtin_mathfn_code (arg0);
6719 if (fcode != END_BUILTINS)
6721 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
6722 if (tem != NULL_TREE)
6728 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6729 First, see if one arg is constant; find the constant arg
6730 and the other one. */
6732 tree constop = 0, varop = NULL_TREE;
6733 int constopnum = -1;
6735 if (TREE_CONSTANT (arg1))
6736 constopnum = 1, constop = arg1, varop = arg0;
6737 if (TREE_CONSTANT (arg0))
6738 constopnum = 0, constop = arg0, varop = arg1;
6740 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
6742 /* This optimization is invalid for ordered comparisons
6743 if CONST+INCR overflows or if foo+incr might overflow.
6744 This optimization is invalid for floating point due to rounding.
6745 For pointer types we assume overflow doesn't happen. */
6746 if (POINTER_TYPE_P (TREE_TYPE (varop))
6747 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6748 && (code == EQ_EXPR || code == NE_EXPR)))
6751 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
6752 constop, TREE_OPERAND (varop, 1)));
6754 /* Do not overwrite the current varop to be a preincrement,
6755 create a new node so that we won't confuse our caller who
6756 might create trees and throw them away, reusing the
6757 arguments that they passed to build. This shows up in
6758 the THEN or ELSE parts of ?: being postincrements. */
6759 varop = build (PREINCREMENT_EXPR, TREE_TYPE (varop),
6760 TREE_OPERAND (varop, 0),
6761 TREE_OPERAND (varop, 1));
6763 /* If VAROP is a reference to a bitfield, we must mask
6764 the constant by the width of the field. */
6765 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6766 && DECL_BIT_FIELD(TREE_OPERAND
6767 (TREE_OPERAND (varop, 0), 1)))
6770 = TREE_INT_CST_LOW (DECL_SIZE
6772 (TREE_OPERAND (varop, 0), 1)));
6773 tree mask, unsigned_type;
6774 unsigned int precision;
6775 tree folded_compare;
6777 /* First check whether the comparison would come out
6778 always the same. If we don't do that we would
6779 change the meaning with the masking. */
6780 if (constopnum == 0)
6781 folded_compare = fold (build (code, type, constop,
6782 TREE_OPERAND (varop, 0)));
6784 folded_compare = fold (build (code, type,
6785 TREE_OPERAND (varop, 0),
6787 if (integer_zerop (folded_compare)
6788 || integer_onep (folded_compare))
6789 return omit_one_operand (type, folded_compare, varop);
6791 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
6792 precision = TYPE_PRECISION (unsigned_type);
6793 mask = build_int_2 (~0, ~0);
6794 TREE_TYPE (mask) = unsigned_type;
6795 force_fit_type (mask, 0);
6796 mask = const_binop (RSHIFT_EXPR, mask,
6797 size_int (precision - size), 0);
6798 newconst = fold (build (BIT_AND_EXPR,
6799 TREE_TYPE (varop), newconst,
6800 convert (TREE_TYPE (varop),
6804 t = build (code, type,
6805 (constopnum == 0) ? newconst : varop,
6806 (constopnum == 1) ? newconst : varop);
6810 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
6812 if (POINTER_TYPE_P (TREE_TYPE (varop))
6813 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6814 && (code == EQ_EXPR || code == NE_EXPR)))
6817 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
6818 constop, TREE_OPERAND (varop, 1)));
6820 /* Do not overwrite the current varop to be a predecrement,
6821 create a new node so that we won't confuse our caller who
6822 might create trees and throw them away, reusing the
6823 arguments that they passed to build. This shows up in
6824 the THEN or ELSE parts of ?: being postdecrements. */
6825 varop = build (PREDECREMENT_EXPR, TREE_TYPE (varop),
6826 TREE_OPERAND (varop, 0),
6827 TREE_OPERAND (varop, 1));
6829 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6830 && DECL_BIT_FIELD(TREE_OPERAND
6831 (TREE_OPERAND (varop, 0), 1)))
6834 = TREE_INT_CST_LOW (DECL_SIZE
6836 (TREE_OPERAND (varop, 0), 1)));
6837 tree mask, unsigned_type;
6838 unsigned int precision;
6839 tree folded_compare;
6841 if (constopnum == 0)
6842 folded_compare = fold (build (code, type, constop,
6843 TREE_OPERAND (varop, 0)));
6845 folded_compare = fold (build (code, type,
6846 TREE_OPERAND (varop, 0),
6848 if (integer_zerop (folded_compare)
6849 || integer_onep (folded_compare))
6850 return omit_one_operand (type, folded_compare, varop);
6852 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
6853 precision = TYPE_PRECISION (unsigned_type);
6854 mask = build_int_2 (~0, ~0);
6855 TREE_TYPE (mask) = TREE_TYPE (varop);
6856 force_fit_type (mask, 0);
6857 mask = const_binop (RSHIFT_EXPR, mask,
6858 size_int (precision - size), 0);
6859 newconst = fold (build (BIT_AND_EXPR,
6860 TREE_TYPE (varop), newconst,
6861 convert (TREE_TYPE (varop),
6865 t = build (code, type,
6866 (constopnum == 0) ? newconst : varop,
6867 (constopnum == 1) ? newconst : varop);
6873 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
6874 This transformation affects the cases which are handled in later
6875 optimizations involving comparisons with non-negative constants. */
6876 if (TREE_CODE (arg1) == INTEGER_CST
6877 && TREE_CODE (arg0) != INTEGER_CST
6878 && tree_int_cst_sgn (arg1) > 0)
6884 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6885 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6890 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6891 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6899 /* Comparisons with the highest or lowest possible integer of
6900 the specified size will have known values. */
6902 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
6904 if (TREE_CODE (arg1) == INTEGER_CST
6905 && ! TREE_CONSTANT_OVERFLOW (arg1)
6906 && width <= HOST_BITS_PER_WIDE_INT
6907 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6908 || POINTER_TYPE_P (TREE_TYPE (arg1))))
6910 unsigned HOST_WIDE_INT signed_max;
6911 unsigned HOST_WIDE_INT max, min;
6913 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
6915 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6917 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
6923 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
6926 if (TREE_INT_CST_HIGH (arg1) == 0
6927 && TREE_INT_CST_LOW (arg1) == max)
6931 return omit_one_operand (type,
6932 convert (type, integer_zero_node),
6938 TREE_SET_CODE (t, EQ_EXPR);
6941 return omit_one_operand (type,
6942 convert (type, integer_one_node),
6948 TREE_SET_CODE (t, NE_EXPR);
6951 /* The GE_EXPR and LT_EXPR cases above are not normally
6952 reached because of previous transformations. */
6957 else if (TREE_INT_CST_HIGH (arg1) == 0
6958 && TREE_INT_CST_LOW (arg1) == max - 1)
6963 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
6964 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6968 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
6969 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6974 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
6975 && TREE_INT_CST_LOW (arg1) == min)
6979 return omit_one_operand (type,
6980 convert (type, integer_zero_node),
6986 TREE_SET_CODE (t, EQ_EXPR);
6990 return omit_one_operand (type,
6991 convert (type, integer_one_node),
6997 TREE_SET_CODE (t, NE_EXPR);
7003 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
7004 && TREE_INT_CST_LOW (arg1) == min + 1)
7009 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7010 t = build (code, type, TREE_OPERAND (t, 0), arg1);
7014 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7015 t = build (code, type, TREE_OPERAND (t, 0), arg1);
7021 else if (TREE_INT_CST_HIGH (arg1) == 0
7022 && TREE_INT_CST_LOW (arg1) == signed_max
7023 && TREE_UNSIGNED (TREE_TYPE (arg1))
7024 /* signed_type does not work on pointer types. */
7025 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
7027 /* The following case also applies to X < signed_max+1
7028 and X >= signed_max+1 because previous transformations. */
7029 if (code == LE_EXPR || code == GT_EXPR)
7032 st0 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg0));
7033 st1 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg1));
7035 (build (code == LE_EXPR ? GE_EXPR: LT_EXPR,
7036 type, convert (st0, arg0),
7037 convert (st1, integer_zero_node)));
7043 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
7044 a MINUS_EXPR of a constant, we can convert it into a comparison with
7045 a revised constant as long as no overflow occurs. */
7046 if ((code == EQ_EXPR || code == NE_EXPR)
7047 && TREE_CODE (arg1) == INTEGER_CST
7048 && (TREE_CODE (arg0) == PLUS_EXPR
7049 || TREE_CODE (arg0) == MINUS_EXPR)
7050 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7051 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
7052 ? MINUS_EXPR : PLUS_EXPR,
7053 arg1, TREE_OPERAND (arg0, 1), 0))
7054 && ! TREE_CONSTANT_OVERFLOW (tem))
7055 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7057 /* Similarly for a NEGATE_EXPR. */
7058 else if ((code == EQ_EXPR || code == NE_EXPR)
7059 && TREE_CODE (arg0) == NEGATE_EXPR
7060 && TREE_CODE (arg1) == INTEGER_CST
7061 && 0 != (tem = negate_expr (arg1))
7062 && TREE_CODE (tem) == INTEGER_CST
7063 && ! TREE_CONSTANT_OVERFLOW (tem))
7064 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7066 /* If we have X - Y == 0, we can convert that to X == Y and similarly
7067 for !=. Don't do this for ordered comparisons due to overflow. */
7068 else if ((code == NE_EXPR || code == EQ_EXPR)
7069 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
7070 return fold (build (code, type,
7071 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
7073 /* If we are widening one operand of an integer comparison,
7074 see if the other operand is similarly being widened. Perhaps we
7075 can do the comparison in the narrower type. */
7076 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
7077 && TREE_CODE (arg0) == NOP_EXPR
7078 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
7079 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
7080 && (TREE_TYPE (t1) == TREE_TYPE (tem)
7081 || (TREE_CODE (t1) == INTEGER_CST
7082 && int_fits_type_p (t1, TREE_TYPE (tem)))))
7083 return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
7085 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
7086 constant, we can simplify it. */
7087 else if (TREE_CODE (arg1) == INTEGER_CST
7088 && (TREE_CODE (arg0) == MIN_EXPR
7089 || TREE_CODE (arg0) == MAX_EXPR)
7090 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7091 return optimize_minmax_comparison (t);
7093 /* If we are comparing an ABS_EXPR with a constant, we can
7094 convert all the cases into explicit comparisons, but they may
7095 well not be faster than doing the ABS and one comparison.
7096 But ABS (X) <= C is a range comparison, which becomes a subtraction
7097 and a comparison, and is probably faster. */
7098 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7099 && TREE_CODE (arg0) == ABS_EXPR
7100 && ! TREE_SIDE_EFFECTS (arg0)
7101 && (0 != (tem = negate_expr (arg1)))
7102 && TREE_CODE (tem) == INTEGER_CST
7103 && ! TREE_CONSTANT_OVERFLOW (tem))
7104 return fold (build (TRUTH_ANDIF_EXPR, type,
7105 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
7106 build (LE_EXPR, type,
7107 TREE_OPERAND (arg0, 0), arg1)));
7109 /* If this is an EQ or NE comparison with zero and ARG0 is
7110 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
7111 two operations, but the latter can be done in one less insn
7112 on machines that have only two-operand insns or on which a
7113 constant cannot be the first operand. */
7114 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
7115 && TREE_CODE (arg0) == BIT_AND_EXPR)
7117 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
7118 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
7120 fold (build (code, type,
7121 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7123 TREE_TYPE (TREE_OPERAND (arg0, 0)),
7124 TREE_OPERAND (arg0, 1),
7125 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
7126 convert (TREE_TYPE (arg0),
7129 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
7130 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
7132 fold (build (code, type,
7133 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7135 TREE_TYPE (TREE_OPERAND (arg0, 1)),
7136 TREE_OPERAND (arg0, 0),
7137 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
7138 convert (TREE_TYPE (arg0),
7143 /* If this is an NE or EQ comparison of zero against the result of a
7144 signed MOD operation whose second operand is a power of 2, make
7145 the MOD operation unsigned since it is simpler and equivalent. */
7146 if ((code == NE_EXPR || code == EQ_EXPR)
7147 && integer_zerop (arg1)
7148 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
7149 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
7150 || TREE_CODE (arg0) == CEIL_MOD_EXPR
7151 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
7152 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
7153 && integer_pow2p (TREE_OPERAND (arg0, 1)))
7155 tree newtype = (*lang_hooks.types.unsigned_type) (TREE_TYPE (arg0));
7156 tree newmod = build (TREE_CODE (arg0), newtype,
7157 convert (newtype, TREE_OPERAND (arg0, 0)),
7158 convert (newtype, TREE_OPERAND (arg0, 1)));
7160 return build (code, type, newmod, convert (newtype, arg1));
7163 /* If this is an NE comparison of zero with an AND of one, remove the
7164 comparison since the AND will give the correct value. */
7165 if (code == NE_EXPR && integer_zerop (arg1)
7166 && TREE_CODE (arg0) == BIT_AND_EXPR
7167 && integer_onep (TREE_OPERAND (arg0, 1)))
7168 return convert (type, arg0);
7170 /* If we have (A & C) == C where C is a power of 2, convert this into
7171 (A & C) != 0. Similarly for NE_EXPR. */
7172 if ((code == EQ_EXPR || code == NE_EXPR)
7173 && TREE_CODE (arg0) == BIT_AND_EXPR
7174 && integer_pow2p (TREE_OPERAND (arg0, 1))
7175 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
7176 return fold (build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
7177 arg0, integer_zero_node));
7179 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
7180 2, then fold the expression into shifts and logical operations. */
7181 tem = fold_single_bit_test (code, arg0, arg1, type);
7185 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
7186 and similarly for >= into !=. */
7187 if ((code == LT_EXPR || code == GE_EXPR)
7188 && TREE_UNSIGNED (TREE_TYPE (arg0))
7189 && TREE_CODE (arg1) == LSHIFT_EXPR
7190 && integer_onep (TREE_OPERAND (arg1, 0)))
7191 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7192 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7193 TREE_OPERAND (arg1, 1)),
7194 convert (TREE_TYPE (arg0), integer_zero_node));
7196 else if ((code == LT_EXPR || code == GE_EXPR)
7197 && TREE_UNSIGNED (TREE_TYPE (arg0))
7198 && (TREE_CODE (arg1) == NOP_EXPR
7199 || TREE_CODE (arg1) == CONVERT_EXPR)
7200 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
7201 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
7203 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7204 convert (TREE_TYPE (arg0),
7205 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7206 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
7207 convert (TREE_TYPE (arg0), integer_zero_node));
7209 /* Simplify comparison of something with itself. (For IEEE
7210 floating-point, we can only do some of these simplifications.) */
7211 if (operand_equal_p (arg0, arg1, 0))
7218 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
7219 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7220 return constant_boolean_node (1, type);
7224 TREE_SET_CODE (t, code);
7228 /* For NE, we can only do this simplification if integer
7229 or we don't honor IEEE floating point NaNs. */
7230 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
7231 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7233 /* ... fall through ... */
7236 return constant_boolean_node (0, type);
7242 /* If we are comparing an expression that just has comparisons
7243 of two integer values, arithmetic expressions of those comparisons,
7244 and constants, we can simplify it. There are only three cases
7245 to check: the two values can either be equal, the first can be
7246 greater, or the second can be greater. Fold the expression for
7247 those three values. Since each value must be 0 or 1, we have
7248 eight possibilities, each of which corresponds to the constant 0
7249 or 1 or one of the six possible comparisons.
7251 This handles common cases like (a > b) == 0 but also handles
7252 expressions like ((x > y) - (y > x)) > 0, which supposedly
7253 occur in macroized code. */
7255 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
7257 tree cval1 = 0, cval2 = 0;
7260 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
7261 /* Don't handle degenerate cases here; they should already
7262 have been handled anyway. */
7263 && cval1 != 0 && cval2 != 0
7264 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
7265 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
7266 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
7267 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
7268 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
7269 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
7270 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
7272 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
7273 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
7275 /* We can't just pass T to eval_subst in case cval1 or cval2
7276 was the same as ARG1. */
7279 = fold (build (code, type,
7280 eval_subst (arg0, cval1, maxval, cval2, minval),
7283 = fold (build (code, type,
7284 eval_subst (arg0, cval1, maxval, cval2, maxval),
7287 = fold (build (code, type,
7288 eval_subst (arg0, cval1, minval, cval2, maxval),
7291 /* All three of these results should be 0 or 1. Confirm they
7292 are. Then use those values to select the proper code
7295 if ((integer_zerop (high_result)
7296 || integer_onep (high_result))
7297 && (integer_zerop (equal_result)
7298 || integer_onep (equal_result))
7299 && (integer_zerop (low_result)
7300 || integer_onep (low_result)))
7302 /* Make a 3-bit mask with the high-order bit being the
7303 value for `>', the next for '=', and the low for '<'. */
7304 switch ((integer_onep (high_result) * 4)
7305 + (integer_onep (equal_result) * 2)
7306 + integer_onep (low_result))
7310 return omit_one_operand (type, integer_zero_node, arg0);
7331 return omit_one_operand (type, integer_one_node, arg0);
7334 t = build (code, type, cval1, cval2);
7336 return save_expr (t);
7343 /* If this is a comparison of a field, we may be able to simplify it. */
7344 if (((TREE_CODE (arg0) == COMPONENT_REF
7345 && (*lang_hooks.can_use_bit_fields_p) ())
7346 || TREE_CODE (arg0) == BIT_FIELD_REF)
7347 && (code == EQ_EXPR || code == NE_EXPR)
7348 /* Handle the constant case even without -O
7349 to make sure the warnings are given. */
7350 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
7352 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
7356 /* If this is a comparison of complex values and either or both sides
7357 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
7358 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
7359 This may prevent needless evaluations. */
7360 if ((code == EQ_EXPR || code == NE_EXPR)
7361 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
7362 && (TREE_CODE (arg0) == COMPLEX_EXPR
7363 || TREE_CODE (arg1) == COMPLEX_EXPR
7364 || TREE_CODE (arg0) == COMPLEX_CST
7365 || TREE_CODE (arg1) == COMPLEX_CST))
7367 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
7368 tree real0, imag0, real1, imag1;
7370 arg0 = save_expr (arg0);
7371 arg1 = save_expr (arg1);
7372 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
7373 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
7374 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
7375 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
7377 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
7380 fold (build (code, type, real0, real1)),
7381 fold (build (code, type, imag0, imag1))));
7384 /* Optimize comparisons of strlen vs zero to a compare of the
7385 first character of the string vs zero. To wit,
7386 strlen(ptr) == 0 => *ptr == 0
7387 strlen(ptr) != 0 => *ptr != 0
7388 Other cases should reduce to one of these two (or a constant)
7389 due to the return value of strlen being unsigned. */
7390 if ((code == EQ_EXPR || code == NE_EXPR)
7391 && integer_zerop (arg1)
7392 && TREE_CODE (arg0) == CALL_EXPR
7393 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ADDR_EXPR)
7395 tree fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7398 if (TREE_CODE (fndecl) == FUNCTION_DECL
7399 && DECL_BUILT_IN (fndecl)
7400 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
7401 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
7402 && (arglist = TREE_OPERAND (arg0, 1))
7403 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
7404 && ! TREE_CHAIN (arglist))
7405 return fold (build (code, type,
7406 build1 (INDIRECT_REF, char_type_node,
7407 TREE_VALUE(arglist)),
7408 integer_zero_node));
7411 /* From here on, the only cases we handle are when the result is
7412 known to be a constant.
7414 To compute GT, swap the arguments and do LT.
7415 To compute GE, do LT and invert the result.
7416 To compute LE, swap the arguments, do LT and invert the result.
7417 To compute NE, do EQ and invert the result.
7419 Therefore, the code below must handle only EQ and LT. */
7421 if (code == LE_EXPR || code == GT_EXPR)
7423 tem = arg0, arg0 = arg1, arg1 = tem;
7424 code = swap_tree_comparison (code);
7427 /* Note that it is safe to invert for real values here because we
7428 will check below in the one case that it matters. */
7432 if (code == NE_EXPR || code == GE_EXPR)
7435 code = invert_tree_comparison (code);
7438 /* Compute a result for LT or EQ if args permit;
7439 otherwise return T. */
7440 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
7442 if (code == EQ_EXPR)
7443 t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0);
7445 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
7446 ? INT_CST_LT_UNSIGNED (arg0, arg1)
7447 : INT_CST_LT (arg0, arg1)),
7451 #if 0 /* This is no longer useful, but breaks some real code. */
7452 /* Assume a nonexplicit constant cannot equal an explicit one,
7453 since such code would be undefined anyway.
7454 Exception: on sysvr4, using #pragma weak,
7455 a label can come out as 0. */
7456 else if (TREE_CODE (arg1) == INTEGER_CST
7457 && !integer_zerop (arg1)
7458 && TREE_CONSTANT (arg0)
7459 && TREE_CODE (arg0) == ADDR_EXPR
7461 t1 = build_int_2 (0, 0);
7463 /* Two real constants can be compared explicitly. */
7464 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
7466 /* If either operand is a NaN, the result is false with two
7467 exceptions: First, an NE_EXPR is true on NaNs, but that case
7468 is already handled correctly since we will be inverting the
7469 result for NE_EXPR. Second, if we had inverted a LE_EXPR
7470 or a GE_EXPR into a LT_EXPR, we must return true so that it
7471 will be inverted into false. */
7473 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
7474 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
7475 t1 = build_int_2 (invert && code == LT_EXPR, 0);
7477 else if (code == EQ_EXPR)
7478 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
7479 TREE_REAL_CST (arg1)),
7482 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
7483 TREE_REAL_CST (arg1)),
7487 if (t1 == NULL_TREE)
7491 TREE_INT_CST_LOW (t1) ^= 1;
7493 TREE_TYPE (t1) = type;
7494 if (TREE_CODE (type) == BOOLEAN_TYPE)
7495 return (*lang_hooks.truthvalue_conversion) (t1);
7499 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
7500 so all simple results must be passed through pedantic_non_lvalue. */
7501 if (TREE_CODE (arg0) == INTEGER_CST)
7502 return pedantic_non_lvalue
7503 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
7504 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
7505 return pedantic_omit_one_operand (type, arg1, arg0);
7507 /* If the second operand is zero, invert the comparison and swap
7508 the second and third operands. Likewise if the second operand
7509 is constant and the third is not or if the third operand is
7510 equivalent to the first operand of the comparison. */
7512 if (integer_zerop (arg1)
7513 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
7514 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
7515 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
7516 TREE_OPERAND (t, 2),
7517 TREE_OPERAND (arg0, 1))))
7519 /* See if this can be inverted. If it can't, possibly because
7520 it was a floating-point inequality comparison, don't do
7522 tem = invert_truthvalue (arg0);
7524 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7526 t = build (code, type, tem,
7527 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7529 /* arg1 should be the first argument of the new T. */
7530 arg1 = TREE_OPERAND (t, 1);
7535 /* If we have A op B ? A : C, we may be able to convert this to a
7536 simpler expression, depending on the operation and the values
7537 of B and C. Signed zeros prevent all of these transformations,
7538 for reasons given above each one. */
7540 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
7541 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
7542 arg1, TREE_OPERAND (arg0, 1))
7543 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
7545 tree arg2 = TREE_OPERAND (t, 2);
7546 enum tree_code comp_code = TREE_CODE (arg0);
7550 /* If we have A op 0 ? A : -A, consider applying the following
7553 A == 0? A : -A same as -A
7554 A != 0? A : -A same as A
7555 A >= 0? A : -A same as abs (A)
7556 A > 0? A : -A same as abs (A)
7557 A <= 0? A : -A same as -abs (A)
7558 A < 0? A : -A same as -abs (A)
7560 None of these transformations work for modes with signed
7561 zeros. If A is +/-0, the first two transformations will
7562 change the sign of the result (from +0 to -0, or vice
7563 versa). The last four will fix the sign of the result,
7564 even though the original expressions could be positive or
7565 negative, depending on the sign of A.
7567 Note that all these transformations are correct if A is
7568 NaN, since the two alternatives (A and -A) are also NaNs. */
7569 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
7570 ? real_zerop (TREE_OPERAND (arg0, 1))
7571 : integer_zerop (TREE_OPERAND (arg0, 1)))
7572 && TREE_CODE (arg2) == NEGATE_EXPR
7573 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
7581 (convert (TREE_TYPE (TREE_OPERAND (t, 1)),
7584 return pedantic_non_lvalue (convert (type, arg1));
7587 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7588 arg1 = convert ((*lang_hooks.types.signed_type)
7589 (TREE_TYPE (arg1)), arg1);
7590 return pedantic_non_lvalue
7591 (convert (type, fold (build1 (ABS_EXPR,
7592 TREE_TYPE (arg1), arg1))));
7595 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7596 arg1 = convert ((lang_hooks.types.signed_type)
7597 (TREE_TYPE (arg1)), arg1);
7598 return pedantic_non_lvalue
7599 (negate_expr (convert (type,
7600 fold (build1 (ABS_EXPR,
7607 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
7608 A == 0 ? A : 0 is always 0 unless A is -0. Note that
7609 both transformations are correct when A is NaN: A != 0
7610 is then true, and A == 0 is false. */
7612 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
7614 if (comp_code == NE_EXPR)
7615 return pedantic_non_lvalue (convert (type, arg1));
7616 else if (comp_code == EQ_EXPR)
7617 return pedantic_non_lvalue (convert (type, integer_zero_node));
7620 /* Try some transformations of A op B ? A : B.
7622 A == B? A : B same as B
7623 A != B? A : B same as A
7624 A >= B? A : B same as max (A, B)
7625 A > B? A : B same as max (B, A)
7626 A <= B? A : B same as min (A, B)
7627 A < B? A : B same as min (B, A)
7629 As above, these transformations don't work in the presence
7630 of signed zeros. For example, if A and B are zeros of
7631 opposite sign, the first two transformations will change
7632 the sign of the result. In the last four, the original
7633 expressions give different results for (A=+0, B=-0) and
7634 (A=-0, B=+0), but the transformed expressions do not.
7636 The first two transformations are correct if either A or B
7637 is a NaN. In the first transformation, the condition will
7638 be false, and B will indeed be chosen. In the case of the
7639 second transformation, the condition A != B will be true,
7640 and A will be chosen.
7642 The conversions to max() and min() are not correct if B is
7643 a number and A is not. The conditions in the original
7644 expressions will be false, so all four give B. The min()
7645 and max() versions would give a NaN instead. */
7646 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
7647 arg2, TREE_OPERAND (arg0, 0)))
7649 tree comp_op0 = TREE_OPERAND (arg0, 0);
7650 tree comp_op1 = TREE_OPERAND (arg0, 1);
7651 tree comp_type = TREE_TYPE (comp_op0);
7653 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
7654 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
7664 return pedantic_non_lvalue (convert (type, arg2));
7666 return pedantic_non_lvalue (convert (type, arg1));
7669 /* In C++ a ?: expression can be an lvalue, so put the
7670 operand which will be used if they are equal first
7671 so that we can convert this back to the
7672 corresponding COND_EXPR. */
7673 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
7674 return pedantic_non_lvalue
7675 (convert (type, fold (build (MIN_EXPR, comp_type,
7676 (comp_code == LE_EXPR
7677 ? comp_op0 : comp_op1),
7678 (comp_code == LE_EXPR
7679 ? comp_op1 : comp_op0)))));
7683 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
7684 return pedantic_non_lvalue
7685 (convert (type, fold (build (MAX_EXPR, comp_type,
7686 (comp_code == GE_EXPR
7687 ? comp_op0 : comp_op1),
7688 (comp_code == GE_EXPR
7689 ? comp_op1 : comp_op0)))));
7696 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
7697 we might still be able to simplify this. For example,
7698 if C1 is one less or one more than C2, this might have started
7699 out as a MIN or MAX and been transformed by this function.
7700 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
7702 if (INTEGRAL_TYPE_P (type)
7703 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7704 && TREE_CODE (arg2) == INTEGER_CST)
7708 /* We can replace A with C1 in this case. */
7709 arg1 = convert (type, TREE_OPERAND (arg0, 1));
7710 t = build (code, type, TREE_OPERAND (t, 0), arg1,
7711 TREE_OPERAND (t, 2));
7715 /* If C1 is C2 + 1, this is min(A, C2). */
7716 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7717 && operand_equal_p (TREE_OPERAND (arg0, 1),
7718 const_binop (PLUS_EXPR, arg2,
7719 integer_one_node, 0), 1))
7720 return pedantic_non_lvalue
7721 (fold (build (MIN_EXPR, type, arg1, arg2)));
7725 /* If C1 is C2 - 1, this is min(A, C2). */
7726 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7727 && operand_equal_p (TREE_OPERAND (arg0, 1),
7728 const_binop (MINUS_EXPR, arg2,
7729 integer_one_node, 0), 1))
7730 return pedantic_non_lvalue
7731 (fold (build (MIN_EXPR, type, arg1, arg2)));
7735 /* If C1 is C2 - 1, this is max(A, C2). */
7736 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7737 && operand_equal_p (TREE_OPERAND (arg0, 1),
7738 const_binop (MINUS_EXPR, arg2,
7739 integer_one_node, 0), 1))
7740 return pedantic_non_lvalue
7741 (fold (build (MAX_EXPR, type, arg1, arg2)));
7745 /* If C1 is C2 + 1, this is max(A, C2). */
7746 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7747 && operand_equal_p (TREE_OPERAND (arg0, 1),
7748 const_binop (PLUS_EXPR, arg2,
7749 integer_one_node, 0), 1))
7750 return pedantic_non_lvalue
7751 (fold (build (MAX_EXPR, type, arg1, arg2)));
7760 /* If the second operand is simpler than the third, swap them
7761 since that produces better jump optimization results. */
7762 if ((TREE_CONSTANT (arg1) || DECL_P (arg1)
7763 || TREE_CODE (arg1) == SAVE_EXPR)
7764 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
7765 || DECL_P (TREE_OPERAND (t, 2))
7766 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
7768 /* See if this can be inverted. If it can't, possibly because
7769 it was a floating-point inequality comparison, don't do
7771 tem = invert_truthvalue (arg0);
7773 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7775 t = build (code, type, tem,
7776 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7778 /* arg1 should be the first argument of the new T. */
7779 arg1 = TREE_OPERAND (t, 1);
7784 /* Convert A ? 1 : 0 to simply A. */
7785 if (integer_onep (TREE_OPERAND (t, 1))
7786 && integer_zerop (TREE_OPERAND (t, 2))
7787 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7788 call to fold will try to move the conversion inside
7789 a COND, which will recurse. In that case, the COND_EXPR
7790 is probably the best choice, so leave it alone. */
7791 && type == TREE_TYPE (arg0))
7792 return pedantic_non_lvalue (arg0);
7794 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
7795 over COND_EXPR in cases such as floating point comparisons. */
7796 if (integer_zerop (TREE_OPERAND (t, 1))
7797 && integer_onep (TREE_OPERAND (t, 2))
7798 && truth_value_p (TREE_CODE (arg0)))
7799 return pedantic_non_lvalue (convert (type,
7800 invert_truthvalue (arg0)));
7802 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7803 operation is simply A & 2. */
7805 if (integer_zerop (TREE_OPERAND (t, 2))
7806 && TREE_CODE (arg0) == NE_EXPR
7807 && integer_zerop (TREE_OPERAND (arg0, 1))
7808 && integer_pow2p (arg1)
7809 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
7810 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
7812 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
7814 /* Convert A ? B : 0 into A && B if A and B are truth values. */
7815 if (integer_zerop (TREE_OPERAND (t, 2))
7816 && truth_value_p (TREE_CODE (arg0))
7817 && truth_value_p (TREE_CODE (arg1)))
7818 return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR, type,
7821 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
7822 if (integer_onep (TREE_OPERAND (t, 2))
7823 && truth_value_p (TREE_CODE (arg0))
7824 && truth_value_p (TREE_CODE (arg1)))
7826 /* Only perform transformation if ARG0 is easily inverted. */
7827 tem = invert_truthvalue (arg0);
7828 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7829 return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR, type,
7836 /* When pedantic, a compound expression can be neither an lvalue
7837 nor an integer constant expression. */
7838 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
7840 /* Don't let (0, 0) be null pointer constant. */
7841 if (integer_zerop (arg1))
7842 return build1 (NOP_EXPR, type, arg1);
7843 return convert (type, arg1);
7847 return build_complex (type, arg0, arg1);
7851 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7853 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7854 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7855 TREE_OPERAND (arg0, 1));
7856 else if (TREE_CODE (arg0) == COMPLEX_CST)
7857 return TREE_REALPART (arg0);
7858 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7859 return fold (build (TREE_CODE (arg0), type,
7860 fold (build1 (REALPART_EXPR, type,
7861 TREE_OPERAND (arg0, 0))),
7862 fold (build1 (REALPART_EXPR,
7863 type, TREE_OPERAND (arg0, 1)))));
7867 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7868 return convert (type, integer_zero_node);
7869 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7870 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7871 TREE_OPERAND (arg0, 0));
7872 else if (TREE_CODE (arg0) == COMPLEX_CST)
7873 return TREE_IMAGPART (arg0);
7874 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7875 return fold (build (TREE_CODE (arg0), type,
7876 fold (build1 (IMAGPART_EXPR, type,
7877 TREE_OPERAND (arg0, 0))),
7878 fold (build1 (IMAGPART_EXPR, type,
7879 TREE_OPERAND (arg0, 1)))));
7882 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7884 case CLEANUP_POINT_EXPR:
7885 if (! has_cleanups (arg0))
7886 return TREE_OPERAND (t, 0);
7889 enum tree_code code0 = TREE_CODE (arg0);
7890 int kind0 = TREE_CODE_CLASS (code0);
7891 tree arg00 = TREE_OPERAND (arg0, 0);
7894 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
7895 return fold (build1 (code0, type,
7896 fold (build1 (CLEANUP_POINT_EXPR,
7897 TREE_TYPE (arg00), arg00))));
7899 if (kind0 == '<' || kind0 == '2'
7900 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
7901 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
7902 || code0 == TRUTH_XOR_EXPR)
7904 arg01 = TREE_OPERAND (arg0, 1);
7906 if (TREE_CONSTANT (arg00)
7907 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
7908 && ! has_cleanups (arg00)))
7909 return fold (build (code0, type, arg00,
7910 fold (build1 (CLEANUP_POINT_EXPR,
7911 TREE_TYPE (arg01), arg01))));
7913 if (TREE_CONSTANT (arg01))
7914 return fold (build (code0, type,
7915 fold (build1 (CLEANUP_POINT_EXPR,
7916 TREE_TYPE (arg00), arg00)),
7924 /* Check for a built-in function. */
7925 if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR
7926 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr, 0), 0))
7928 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr, 0), 0)))
7930 tree tmp = fold_builtin (expr);
7938 } /* switch (code) */
7941 #ifdef ENABLE_FOLD_CHECKING
7944 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
7945 static void fold_check_failed (tree, tree);
7946 void print_fold_checksum (tree);
7948 /* When --enable-checking=fold, compute a digest of expr before
7949 and after actual fold call to see if fold did not accidentally
7950 change original expr. */
7957 unsigned char checksum_before[16], checksum_after[16];
7960 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
7961 md5_init_ctx (&ctx);
7962 fold_checksum_tree (expr, &ctx, ht);
7963 md5_finish_ctx (&ctx, checksum_before);
7966 ret = fold_1 (expr);
7968 md5_init_ctx (&ctx);
7969 fold_checksum_tree (expr, &ctx, ht);
7970 md5_finish_ctx (&ctx, checksum_after);
7973 if (memcmp (checksum_before, checksum_after, 16))
7974 fold_check_failed (expr, ret);
7980 print_fold_checksum (tree expr)
7983 unsigned char checksum[16], cnt;
7986 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
7987 md5_init_ctx (&ctx);
7988 fold_checksum_tree (expr, &ctx, ht);
7989 md5_finish_ctx (&ctx, checksum);
7991 for (cnt = 0; cnt < 16; ++cnt)
7992 fprintf (stderr, "%02x", checksum[cnt]);
7993 putc ('\n', stderr);
7997 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
7999 internal_error ("fold check: original tree changed by fold");
8003 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
8006 enum tree_code code;
8007 char buf[sizeof (struct tree_decl)];
8010 if (sizeof (struct tree_exp) + 5 * sizeof (tree)
8011 > sizeof (struct tree_decl)
8012 || sizeof (struct tree_type) > sizeof (struct tree_decl))
8016 slot = htab_find_slot (ht, expr, INSERT);
8020 code = TREE_CODE (expr);
8021 if (code == SAVE_EXPR && SAVE_EXPR_NOPLACEHOLDER (expr))
8023 /* Allow SAVE_EXPR_NOPLACEHOLDER flag to be modified. */
8024 memcpy (buf, expr, tree_size (expr));
8026 SAVE_EXPR_NOPLACEHOLDER (expr) = 0;
8028 else if (TREE_CODE_CLASS (code) == 'd' && DECL_ASSEMBLER_NAME_SET_P (expr))
8030 /* Allow DECL_ASSEMBLER_NAME to be modified. */
8031 memcpy (buf, expr, tree_size (expr));
8033 SET_DECL_ASSEMBLER_NAME (expr, NULL);
8035 else if (TREE_CODE_CLASS (code) == 't'
8036 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)))
8038 /* Allow TYPE_POINTER_TO and TYPE_REFERENCE_TO to be modified. */
8039 memcpy (buf, expr, tree_size (expr));
8041 TYPE_POINTER_TO (expr) = NULL;
8042 TYPE_REFERENCE_TO (expr) = NULL;
8044 md5_process_bytes (expr, tree_size (expr), ctx);
8045 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
8046 if (TREE_CODE_CLASS (code) != 't' && TREE_CODE_CLASS (code) != 'd')
8047 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
8048 len = TREE_CODE_LENGTH (code);
8049 switch (TREE_CODE_CLASS (code))
8055 md5_process_bytes (TREE_STRING_POINTER (expr),
8056 TREE_STRING_LENGTH (expr), ctx);
8059 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
8060 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
8063 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
8073 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
8074 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
8077 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
8078 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
8087 case SAVE_EXPR: len = 2; break;
8088 case GOTO_SUBROUTINE_EXPR: len = 0; break;
8089 case RTL_EXPR: len = 0; break;
8090 case WITH_CLEANUP_EXPR: len = 2; break;
8099 for (i = 0; i < len; ++i)
8100 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
8103 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
8104 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
8105 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
8106 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
8107 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
8108 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
8109 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
8110 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
8111 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
8112 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
8113 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
8116 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
8117 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
8118 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
8119 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
8120 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
8121 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
8122 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
8123 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
8124 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
8125 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
8134 /* Perform constant folding and related simplification of intializer
8135 expression EXPR. This behaves identically to "fold" but ignores
8136 potential run-time traps and exceptions that fold must preserve. */
8139 fold_initializer (tree expr)
8141 int saved_signaling_nans = flag_signaling_nans;
8142 int saved_trapping_math = flag_trapping_math;
8143 int saved_trapv = flag_trapv;
8146 flag_signaling_nans = 0;
8147 flag_trapping_math = 0;
8150 result = fold (expr);
8152 flag_signaling_nans = saved_signaling_nans;
8153 flag_trapping_math = saved_trapping_math;
8154 flag_trapv = saved_trapv;
8159 /* Determine if first argument is a multiple of second argument. Return 0 if
8160 it is not, or we cannot easily determined it to be.
8162 An example of the sort of thing we care about (at this point; this routine
8163 could surely be made more general, and expanded to do what the *_DIV_EXPR's
8164 fold cases do now) is discovering that
8166 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
8172 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
8174 This code also handles discovering that
8176 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
8178 is a multiple of 8 so we don't have to worry about dealing with a
8181 Note that we *look* inside a SAVE_EXPR only to determine how it was
8182 calculated; it is not safe for fold to do much of anything else with the
8183 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
8184 at run time. For example, the latter example above *cannot* be implemented
8185 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
8186 evaluation time of the original SAVE_EXPR is not necessarily the same at
8187 the time the new expression is evaluated. The only optimization of this
8188 sort that would be valid is changing
8190 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
8194 SAVE_EXPR (I) * SAVE_EXPR (J)
8196 (where the same SAVE_EXPR (J) is used in the original and the
8197 transformed version). */
8200 multiple_of_p (tree type, tree top, tree bottom)
8202 if (operand_equal_p (top, bottom, 0))
8205 if (TREE_CODE (type) != INTEGER_TYPE)
8208 switch (TREE_CODE (top))
8211 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
8212 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
8216 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
8217 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
8220 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
8224 op1 = TREE_OPERAND (top, 1);
8225 /* const_binop may not detect overflow correctly,
8226 so check for it explicitly here. */
8227 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
8228 > TREE_INT_CST_LOW (op1)
8229 && TREE_INT_CST_HIGH (op1) == 0
8230 && 0 != (t1 = convert (type,
8231 const_binop (LSHIFT_EXPR, size_one_node,
8233 && ! TREE_OVERFLOW (t1))
8234 return multiple_of_p (type, t1, bottom);
8239 /* Can't handle conversions from non-integral or wider integral type. */
8240 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
8241 || (TYPE_PRECISION (type)
8242 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
8245 /* .. fall through ... */
8248 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
8251 if (TREE_CODE (bottom) != INTEGER_CST
8252 || (TREE_UNSIGNED (type)
8253 && (tree_int_cst_sgn (top) < 0
8254 || tree_int_cst_sgn (bottom) < 0)))
8256 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
8264 /* Return true if `t' is known to be non-negative. */
8267 tree_expr_nonnegative_p (tree t)
8269 switch (TREE_CODE (t))
8279 /* These are undefined at zero. This is true even if
8280 C[LT]Z_DEFINED_VALUE_AT_ZERO is set, since what we're
8281 computing here is a user-visible property. */
8285 return tree_int_cst_sgn (t) >= 0;
8288 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
8291 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8292 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8293 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8295 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
8296 both unsigned and at least 2 bits shorter than the result. */
8297 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8298 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8299 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8301 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8302 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8303 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8304 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8306 unsigned int prec = MAX (TYPE_PRECISION (inner1),
8307 TYPE_PRECISION (inner2)) + 1;
8308 return prec < TYPE_PRECISION (TREE_TYPE (t));
8314 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8316 /* x * x for floating point x is always non-negative. */
8317 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
8319 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8320 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8323 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
8324 both unsigned and their total bits is shorter than the result. */
8325 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8326 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8327 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8329 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8330 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8331 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8332 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8333 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
8334 < TYPE_PRECISION (TREE_TYPE (t));
8338 case TRUNC_DIV_EXPR:
8340 case FLOOR_DIV_EXPR:
8341 case ROUND_DIV_EXPR:
8342 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8343 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8345 case TRUNC_MOD_EXPR:
8347 case FLOOR_MOD_EXPR:
8348 case ROUND_MOD_EXPR:
8349 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8352 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8353 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8357 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
8358 tree outer_type = TREE_TYPE (t);
8360 if (TREE_CODE (outer_type) == REAL_TYPE)
8362 if (TREE_CODE (inner_type) == REAL_TYPE)
8363 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8364 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8366 if (TREE_UNSIGNED (inner_type))
8368 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8371 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
8373 if (TREE_CODE (inner_type) == REAL_TYPE)
8374 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
8375 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8376 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
8377 && TREE_UNSIGNED (inner_type);
8383 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
8384 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
8386 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8388 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8389 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8391 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8392 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8394 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8396 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8398 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8399 case NON_LVALUE_EXPR:
8400 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8402 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8404 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
8407 if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR)
8409 tree fndecl = TREE_OPERAND (TREE_OPERAND (t, 0), 0);
8410 tree arglist = TREE_OPERAND (t, 1);
8411 if (TREE_CODE (fndecl) == FUNCTION_DECL
8412 && DECL_BUILT_IN (fndecl)
8413 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD)
8414 switch (DECL_FUNCTION_CODE (fndecl))
8417 case BUILT_IN_CABSL:
8418 case BUILT_IN_CABSF:
8423 case BUILT_IN_FABSF:
8424 case BUILT_IN_FABSL:
8426 case BUILT_IN_SQRTF:
8427 case BUILT_IN_SQRTL:
8431 case BUILT_IN_ATANF:
8432 case BUILT_IN_ATANL:
8434 case BUILT_IN_CEILF:
8435 case BUILT_IN_CEILL:
8436 case BUILT_IN_FLOOR:
8437 case BUILT_IN_FLOORF:
8438 case BUILT_IN_FLOORL:
8439 case BUILT_IN_NEARBYINT:
8440 case BUILT_IN_NEARBYINTF:
8441 case BUILT_IN_NEARBYINTL:
8442 case BUILT_IN_ROUND:
8443 case BUILT_IN_ROUNDF:
8444 case BUILT_IN_ROUNDL:
8445 case BUILT_IN_TRUNC:
8446 case BUILT_IN_TRUNCF:
8447 case BUILT_IN_TRUNCL:
8448 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
8453 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
8460 /* ... fall through ... */
8463 if (truth_value_p (TREE_CODE (t)))
8464 /* Truth values evaluate to 0 or 1, which is nonnegative. */
8468 /* We don't know sign of `t', so be conservative and return false. */
8472 /* Return true if `r' is known to be non-negative.
8473 Only handles constants at the moment. */
8476 rtl_expr_nonnegative_p (rtx r)
8478 switch (GET_CODE (r))
8481 return INTVAL (r) >= 0;
8484 if (GET_MODE (r) == VOIDmode)
8485 return CONST_DOUBLE_HIGH (r) >= 0;
8493 units = CONST_VECTOR_NUNITS (r);
8495 for (i = 0; i < units; ++i)
8497 elt = CONST_VECTOR_ELT (r, i);
8498 if (!rtl_expr_nonnegative_p (elt))
8507 /* These are always nonnegative. */
8515 #include "gt-fold-const.h"