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));
847 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
848 return ! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations;
856 /* Given T, an expression, return the negation of T. Allow for T to be
857 null, in which case return null. */
868 type = TREE_TYPE (t);
871 switch (TREE_CODE (t))
875 if (! TREE_UNSIGNED (type)
876 && 0 != (tem = fold (build1 (NEGATE_EXPR, type, t)))
877 && ! TREE_OVERFLOW (tem))
882 return convert (type, TREE_OPERAND (t, 0));
885 /* - (A - B) -> B - A */
886 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
887 return convert (type,
888 fold (build (MINUS_EXPR, TREE_TYPE (t),
890 TREE_OPERAND (t, 0))));
897 return convert (type, fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t)));
900 /* Split a tree IN into a constant, literal and variable parts that could be
901 combined with CODE to make IN. "constant" means an expression with
902 TREE_CONSTANT but that isn't an actual constant. CODE must be a
903 commutative arithmetic operation. Store the constant part into *CONP,
904 the literal in *LITP and return the variable part. If a part isn't
905 present, set it to null. If the tree does not decompose in this way,
906 return the entire tree as the variable part and the other parts as null.
908 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
909 case, we negate an operand that was subtracted. Except if it is a
910 literal for which we use *MINUS_LITP instead.
912 If NEGATE_P is true, we are negating all of IN, again except a literal
913 for which we use *MINUS_LITP instead.
915 If IN is itself a literal or constant, return it as appropriate.
917 Note that we do not guarantee that any of the three values will be the
918 same type as IN, but they will have the same signedness and mode. */
921 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
922 tree *minus_litp, int negate_p)
930 /* Strip any conversions that don't change the machine mode or signedness. */
931 STRIP_SIGN_NOPS (in);
933 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
935 else if (TREE_CODE (in) == code
936 || (! FLOAT_TYPE_P (TREE_TYPE (in))
937 /* We can associate addition and subtraction together (even
938 though the C standard doesn't say so) for integers because
939 the value is not affected. For reals, the value might be
940 affected, so we can't. */
941 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
942 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
944 tree op0 = TREE_OPERAND (in, 0);
945 tree op1 = TREE_OPERAND (in, 1);
946 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
947 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
949 /* First see if either of the operands is a literal, then a constant. */
950 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
951 *litp = op0, op0 = 0;
952 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
953 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
955 if (op0 != 0 && TREE_CONSTANT (op0))
956 *conp = op0, op0 = 0;
957 else if (op1 != 0 && TREE_CONSTANT (op1))
958 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
960 /* If we haven't dealt with either operand, this is not a case we can
961 decompose. Otherwise, VAR is either of the ones remaining, if any. */
962 if (op0 != 0 && op1 != 0)
967 var = op1, neg_var_p = neg1_p;
969 /* Now do any needed negations. */
971 *minus_litp = *litp, *litp = 0;
973 *conp = negate_expr (*conp);
975 var = negate_expr (var);
977 else if (TREE_CONSTANT (in))
985 *minus_litp = *litp, *litp = 0;
986 else if (*minus_litp)
987 *litp = *minus_litp, *minus_litp = 0;
988 *conp = negate_expr (*conp);
989 var = negate_expr (var);
995 /* Re-associate trees split by the above function. T1 and T2 are either
996 expressions to associate or null. Return the new expression, if any. If
997 we build an operation, do it in TYPE and with CODE. */
1000 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1007 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1008 try to fold this since we will have infinite recursion. But do
1009 deal with any NEGATE_EXPRs. */
1010 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1011 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1013 if (code == PLUS_EXPR)
1015 if (TREE_CODE (t1) == NEGATE_EXPR)
1016 return build (MINUS_EXPR, type, convert (type, t2),
1017 convert (type, TREE_OPERAND (t1, 0)));
1018 else if (TREE_CODE (t2) == NEGATE_EXPR)
1019 return build (MINUS_EXPR, type, convert (type, t1),
1020 convert (type, TREE_OPERAND (t2, 0)));
1022 return build (code, type, convert (type, t1), convert (type, t2));
1025 return fold (build (code, type, convert (type, t1), convert (type, t2)));
1028 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1029 to produce a new constant.
1031 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1034 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1036 unsigned HOST_WIDE_INT int1l, int2l;
1037 HOST_WIDE_INT int1h, int2h;
1038 unsigned HOST_WIDE_INT low;
1040 unsigned HOST_WIDE_INT garbagel;
1041 HOST_WIDE_INT garbageh;
1043 tree type = TREE_TYPE (arg1);
1044 int uns = TREE_UNSIGNED (type);
1046 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1048 int no_overflow = 0;
1050 int1l = TREE_INT_CST_LOW (arg1);
1051 int1h = TREE_INT_CST_HIGH (arg1);
1052 int2l = TREE_INT_CST_LOW (arg2);
1053 int2h = TREE_INT_CST_HIGH (arg2);
1058 low = int1l | int2l, hi = int1h | int2h;
1062 low = int1l ^ int2l, hi = int1h ^ int2h;
1066 low = int1l & int2l, hi = int1h & int2h;
1069 case BIT_ANDTC_EXPR:
1070 low = int1l & ~int2l, hi = int1h & ~int2h;
1076 /* It's unclear from the C standard whether shifts can overflow.
1077 The following code ignores overflow; perhaps a C standard
1078 interpretation ruling is needed. */
1079 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1087 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1092 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1096 neg_double (int2l, int2h, &low, &hi);
1097 add_double (int1l, int1h, low, hi, &low, &hi);
1098 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1102 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1105 case TRUNC_DIV_EXPR:
1106 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1107 case EXACT_DIV_EXPR:
1108 /* This is a shortcut for a common special case. */
1109 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1110 && ! TREE_CONSTANT_OVERFLOW (arg1)
1111 && ! TREE_CONSTANT_OVERFLOW (arg2)
1112 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1114 if (code == CEIL_DIV_EXPR)
1117 low = int1l / int2l, hi = 0;
1121 /* ... fall through ... */
1123 case ROUND_DIV_EXPR:
1124 if (int2h == 0 && int2l == 1)
1126 low = int1l, hi = int1h;
1129 if (int1l == int2l && int1h == int2h
1130 && ! (int1l == 0 && int1h == 0))
1135 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1136 &low, &hi, &garbagel, &garbageh);
1139 case TRUNC_MOD_EXPR:
1140 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1141 /* This is a shortcut for a common special case. */
1142 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1143 && ! TREE_CONSTANT_OVERFLOW (arg1)
1144 && ! TREE_CONSTANT_OVERFLOW (arg2)
1145 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1147 if (code == CEIL_MOD_EXPR)
1149 low = int1l % int2l, hi = 0;
1153 /* ... fall through ... */
1155 case ROUND_MOD_EXPR:
1156 overflow = div_and_round_double (code, uns,
1157 int1l, int1h, int2l, int2h,
1158 &garbagel, &garbageh, &low, &hi);
1164 low = (((unsigned HOST_WIDE_INT) int1h
1165 < (unsigned HOST_WIDE_INT) int2h)
1166 || (((unsigned HOST_WIDE_INT) int1h
1167 == (unsigned HOST_WIDE_INT) int2h)
1170 low = (int1h < int2h
1171 || (int1h == int2h && int1l < int2l));
1173 if (low == (code == MIN_EXPR))
1174 low = int1l, hi = int1h;
1176 low = int2l, hi = int2h;
1183 /* If this is for a sizetype, can be represented as one (signed)
1184 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1187 && ((hi == 0 && (HOST_WIDE_INT) low >= 0)
1188 || (hi == -1 && (HOST_WIDE_INT) low < 0))
1189 && overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1190 return size_int_type_wide (low, type);
1193 t = build_int_2 (low, hi);
1194 TREE_TYPE (t) = TREE_TYPE (arg1);
1199 ? (!uns || is_sizetype) && overflow
1200 : (force_fit_type (t, (!uns || is_sizetype) && overflow)
1202 | TREE_OVERFLOW (arg1)
1203 | TREE_OVERFLOW (arg2));
1205 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1206 So check if force_fit_type truncated the value. */
1208 && ! TREE_OVERFLOW (t)
1209 && (TREE_INT_CST_HIGH (t) != hi
1210 || TREE_INT_CST_LOW (t) != low))
1211 TREE_OVERFLOW (t) = 1;
1213 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1214 | TREE_CONSTANT_OVERFLOW (arg1)
1215 | TREE_CONSTANT_OVERFLOW (arg2));
1219 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1220 constant. We assume ARG1 and ARG2 have the same data type, or at least
1221 are the same kind of constant and the same machine mode.
1223 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1226 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1231 if (TREE_CODE (arg1) == INTEGER_CST)
1232 return int_const_binop (code, arg1, arg2, notrunc);
1234 if (TREE_CODE (arg1) == REAL_CST)
1236 enum machine_mode mode;
1239 REAL_VALUE_TYPE value;
1242 d1 = TREE_REAL_CST (arg1);
1243 d2 = TREE_REAL_CST (arg2);
1245 type = TREE_TYPE (arg1);
1246 mode = TYPE_MODE (type);
1248 /* Don't perform operation if we honor signaling NaNs and
1249 either operand is a NaN. */
1250 if (HONOR_SNANS (mode)
1251 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1254 /* Don't perform operation if it would raise a division
1255 by zero exception. */
1256 if (code == RDIV_EXPR
1257 && REAL_VALUES_EQUAL (d2, dconst0)
1258 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1261 /* If either operand is a NaN, just return it. Otherwise, set up
1262 for floating-point trap; we return an overflow. */
1263 if (REAL_VALUE_ISNAN (d1))
1265 else if (REAL_VALUE_ISNAN (d2))
1268 REAL_ARITHMETIC (value, code, d1, d2);
1270 t = build_real (type, real_value_truncate (mode, value));
1273 = (force_fit_type (t, 0)
1274 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1275 TREE_CONSTANT_OVERFLOW (t)
1277 | TREE_CONSTANT_OVERFLOW (arg1)
1278 | TREE_CONSTANT_OVERFLOW (arg2);
1281 if (TREE_CODE (arg1) == COMPLEX_CST)
1283 tree type = TREE_TYPE (arg1);
1284 tree r1 = TREE_REALPART (arg1);
1285 tree i1 = TREE_IMAGPART (arg1);
1286 tree r2 = TREE_REALPART (arg2);
1287 tree i2 = TREE_IMAGPART (arg2);
1293 t = build_complex (type,
1294 const_binop (PLUS_EXPR, r1, r2, notrunc),
1295 const_binop (PLUS_EXPR, i1, i2, notrunc));
1299 t = build_complex (type,
1300 const_binop (MINUS_EXPR, r1, r2, notrunc),
1301 const_binop (MINUS_EXPR, i1, i2, notrunc));
1305 t = build_complex (type,
1306 const_binop (MINUS_EXPR,
1307 const_binop (MULT_EXPR,
1309 const_binop (MULT_EXPR,
1312 const_binop (PLUS_EXPR,
1313 const_binop (MULT_EXPR,
1315 const_binop (MULT_EXPR,
1323 = const_binop (PLUS_EXPR,
1324 const_binop (MULT_EXPR, r2, r2, notrunc),
1325 const_binop (MULT_EXPR, i2, i2, notrunc),
1328 t = build_complex (type,
1330 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1331 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1332 const_binop (PLUS_EXPR,
1333 const_binop (MULT_EXPR, r1, r2,
1335 const_binop (MULT_EXPR, i1, i2,
1338 magsquared, notrunc),
1340 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1341 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1342 const_binop (MINUS_EXPR,
1343 const_binop (MULT_EXPR, i1, r2,
1345 const_binop (MULT_EXPR, r1, i2,
1348 magsquared, notrunc));
1360 /* These are the hash table functions for the hash table of INTEGER_CST
1361 nodes of a sizetype. */
1363 /* Return the hash code code X, an INTEGER_CST. */
1366 size_htab_hash (const void *x)
1370 return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
1371 ^ htab_hash_pointer (TREE_TYPE (t))
1372 ^ (TREE_OVERFLOW (t) << 20));
1375 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1376 is the same as that given by *Y, which is the same. */
1379 size_htab_eq (const void *x, const void *y)
1384 return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
1385 && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt)
1386 && TREE_TYPE (xt) == TREE_TYPE (yt)
1387 && TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt));
1390 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1391 bits are given by NUMBER and of the sizetype represented by KIND. */
1394 size_int_wide (HOST_WIDE_INT number, enum size_type_kind kind)
1396 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1399 /* Likewise, but the desired type is specified explicitly. */
1401 static GTY (()) tree new_const;
1402 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
1406 size_int_type_wide (HOST_WIDE_INT number, tree type)
1412 size_htab = htab_create_ggc (1024, size_htab_hash, size_htab_eq, NULL);
1413 new_const = make_node (INTEGER_CST);
1416 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1417 hash table, we return the value from the hash table. Otherwise, we
1418 place that in the hash table and make a new node for the next time. */
1419 TREE_INT_CST_LOW (new_const) = number;
1420 TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0;
1421 TREE_TYPE (new_const) = type;
1422 TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const)
1423 = force_fit_type (new_const, 0);
1425 slot = htab_find_slot (size_htab, new_const, INSERT);
1431 new_const = make_node (INTEGER_CST);
1435 return (tree) *slot;
1438 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1439 is a tree code. The type of the result is taken from the operands.
1440 Both must be the same type integer type and it must be a size type.
1441 If the operands are constant, so is the result. */
1444 size_binop (enum tree_code code, tree arg0, tree arg1)
1446 tree type = TREE_TYPE (arg0);
1448 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1449 || type != TREE_TYPE (arg1))
1452 /* Handle the special case of two integer constants faster. */
1453 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1455 /* And some specific cases even faster than that. */
1456 if (code == PLUS_EXPR && integer_zerop (arg0))
1458 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1459 && integer_zerop (arg1))
1461 else if (code == MULT_EXPR && integer_onep (arg0))
1464 /* Handle general case of two integer constants. */
1465 return int_const_binop (code, arg0, arg1, 0);
1468 if (arg0 == error_mark_node || arg1 == error_mark_node)
1469 return error_mark_node;
1471 return fold (build (code, type, arg0, arg1));
1474 /* Given two values, either both of sizetype or both of bitsizetype,
1475 compute the difference between the two values. Return the value
1476 in signed type corresponding to the type of the operands. */
1479 size_diffop (tree arg0, tree arg1)
1481 tree type = TREE_TYPE (arg0);
1484 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1485 || type != TREE_TYPE (arg1))
1488 /* If the type is already signed, just do the simple thing. */
1489 if (! TREE_UNSIGNED (type))
1490 return size_binop (MINUS_EXPR, arg0, arg1);
1492 ctype = (type == bitsizetype || type == ubitsizetype
1493 ? sbitsizetype : ssizetype);
1495 /* If either operand is not a constant, do the conversions to the signed
1496 type and subtract. The hardware will do the right thing with any
1497 overflow in the subtraction. */
1498 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1499 return size_binop (MINUS_EXPR, convert (ctype, arg0),
1500 convert (ctype, arg1));
1502 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1503 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1504 overflow) and negate (which can't either). Special-case a result
1505 of zero while we're here. */
1506 if (tree_int_cst_equal (arg0, arg1))
1507 return convert (ctype, integer_zero_node);
1508 else if (tree_int_cst_lt (arg1, arg0))
1509 return convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1511 return size_binop (MINUS_EXPR, convert (ctype, integer_zero_node),
1512 convert (ctype, size_binop (MINUS_EXPR, arg1, arg0)));
1516 /* Given T, a tree representing type conversion of ARG1, a constant,
1517 return a constant tree representing the result of conversion. */
1520 fold_convert (tree t, tree arg1)
1522 tree type = TREE_TYPE (t);
1525 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1527 if (TREE_CODE (arg1) == INTEGER_CST)
1529 /* If we would build a constant wider than GCC supports,
1530 leave the conversion unfolded. */
1531 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1534 /* If we are trying to make a sizetype for a small integer, use
1535 size_int to pick up cached types to reduce duplicate nodes. */
1536 if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1537 && !TREE_CONSTANT_OVERFLOW (arg1)
1538 && compare_tree_int (arg1, 10000) < 0)
1539 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
1541 /* Given an integer constant, make new constant with new type,
1542 appropriately sign-extended or truncated. */
1543 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1544 TREE_INT_CST_HIGH (arg1));
1545 TREE_TYPE (t) = type;
1546 /* Indicate an overflow if (1) ARG1 already overflowed,
1547 or (2) force_fit_type indicates an overflow.
1548 Tell force_fit_type that an overflow has already occurred
1549 if ARG1 is a too-large unsigned value and T is signed.
1550 But don't indicate an overflow if converting a pointer. */
1552 = ((force_fit_type (t,
1553 (TREE_INT_CST_HIGH (arg1) < 0
1554 && (TREE_UNSIGNED (type)
1555 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
1556 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1557 || TREE_OVERFLOW (arg1));
1558 TREE_CONSTANT_OVERFLOW (t)
1559 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1561 else if (TREE_CODE (arg1) == REAL_CST)
1563 /* Don't initialize these, use assignments.
1564 Initialized local aggregates don't work on old compilers. */
1568 tree type1 = TREE_TYPE (arg1);
1571 x = TREE_REAL_CST (arg1);
1572 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
1574 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
1575 if (!no_upper_bound)
1576 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
1578 /* See if X will be in range after truncation towards 0.
1579 To compensate for truncation, move the bounds away from 0,
1580 but reject if X exactly equals the adjusted bounds. */
1581 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
1582 if (!no_upper_bound)
1583 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
1584 /* If X is a NaN, use zero instead and show we have an overflow.
1585 Otherwise, range check. */
1586 if (REAL_VALUE_ISNAN (x))
1587 overflow = 1, x = dconst0;
1588 else if (! (REAL_VALUES_LESS (l, x)
1590 && REAL_VALUES_LESS (x, u)))
1594 HOST_WIDE_INT low, high;
1595 REAL_VALUE_TO_INT (&low, &high, x);
1596 t = build_int_2 (low, high);
1598 TREE_TYPE (t) = type;
1600 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1601 TREE_CONSTANT_OVERFLOW (t)
1602 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1604 TREE_TYPE (t) = type;
1606 else if (TREE_CODE (type) == REAL_TYPE)
1608 if (TREE_CODE (arg1) == INTEGER_CST)
1609 return build_real_from_int_cst (type, arg1);
1610 if (TREE_CODE (arg1) == REAL_CST)
1612 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1614 /* We make a copy of ARG1 so that we don't modify an
1615 existing constant tree. */
1616 t = copy_node (arg1);
1617 TREE_TYPE (t) = type;
1621 t = build_real (type,
1622 real_value_truncate (TYPE_MODE (type),
1623 TREE_REAL_CST (arg1)));
1626 = TREE_OVERFLOW (arg1) | force_fit_type (t, 0);
1627 TREE_CONSTANT_OVERFLOW (t)
1628 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1632 TREE_CONSTANT (t) = 1;
1636 /* Return an expr equal to X but certainly not valid as an lvalue. */
1643 /* These things are certainly not lvalues. */
1644 if (TREE_CODE (x) == NON_LVALUE_EXPR
1645 || TREE_CODE (x) == INTEGER_CST
1646 || TREE_CODE (x) == REAL_CST
1647 || TREE_CODE (x) == STRING_CST
1648 || TREE_CODE (x) == ADDR_EXPR)
1651 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
1652 TREE_CONSTANT (result) = TREE_CONSTANT (x);
1656 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1657 Zero means allow extended lvalues. */
1659 int pedantic_lvalues;
1661 /* When pedantic, return an expr equal to X but certainly not valid as a
1662 pedantic lvalue. Otherwise, return X. */
1665 pedantic_non_lvalue (tree x)
1667 if (pedantic_lvalues)
1668 return non_lvalue (x);
1673 /* Given a tree comparison code, return the code that is the logical inverse
1674 of the given code. It is not safe to do this for floating-point
1675 comparisons, except for NE_EXPR and EQ_EXPR. */
1677 static enum tree_code
1678 invert_tree_comparison (enum tree_code code)
1699 /* Similar, but return the comparison that results if the operands are
1700 swapped. This is safe for floating-point. */
1702 static enum tree_code
1703 swap_tree_comparison (enum tree_code code)
1724 /* Convert a comparison tree code from an enum tree_code representation
1725 into a compcode bit-based encoding. This function is the inverse of
1726 compcode_to_comparison. */
1729 comparison_to_compcode (enum tree_code code)
1750 /* Convert a compcode bit-based encoding of a comparison operator back
1751 to GCC's enum tree_code representation. This function is the
1752 inverse of comparison_to_compcode. */
1754 static enum tree_code
1755 compcode_to_comparison (int code)
1776 /* Return nonzero if CODE is a tree code that represents a truth value. */
1779 truth_value_p (enum tree_code code)
1781 return (TREE_CODE_CLASS (code) == '<'
1782 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
1783 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
1784 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
1787 /* Return nonzero if two operands are necessarily equal.
1788 If ONLY_CONST is nonzero, only return nonzero for constants.
1789 This function tests whether the operands are indistinguishable;
1790 it does not test whether they are equal using C's == operation.
1791 The distinction is important for IEEE floating point, because
1792 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
1793 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
1796 operand_equal_p (tree arg0, tree arg1, int only_const)
1798 /* If both types don't have the same signedness, then we can't consider
1799 them equal. We must check this before the STRIP_NOPS calls
1800 because they may change the signedness of the arguments. */
1801 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
1807 if (TREE_CODE (arg0) != TREE_CODE (arg1)
1808 /* This is needed for conversions and for COMPONENT_REF.
1809 Might as well play it safe and always test this. */
1810 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
1811 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
1812 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
1815 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
1816 We don't care about side effects in that case because the SAVE_EXPR
1817 takes care of that for us. In all other cases, two expressions are
1818 equal if they have no side effects. If we have two identical
1819 expressions with side effects that should be treated the same due
1820 to the only side effects being identical SAVE_EXPR's, that will
1821 be detected in the recursive calls below. */
1822 if (arg0 == arg1 && ! only_const
1823 && (TREE_CODE (arg0) == SAVE_EXPR
1824 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
1827 /* Next handle constant cases, those for which we can return 1 even
1828 if ONLY_CONST is set. */
1829 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
1830 switch (TREE_CODE (arg0))
1833 return (! TREE_CONSTANT_OVERFLOW (arg0)
1834 && ! TREE_CONSTANT_OVERFLOW (arg1)
1835 && tree_int_cst_equal (arg0, arg1));
1838 return (! TREE_CONSTANT_OVERFLOW (arg0)
1839 && ! TREE_CONSTANT_OVERFLOW (arg1)
1840 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
1841 TREE_REAL_CST (arg1)));
1847 if (TREE_CONSTANT_OVERFLOW (arg0)
1848 || TREE_CONSTANT_OVERFLOW (arg1))
1851 v1 = TREE_VECTOR_CST_ELTS (arg0);
1852 v2 = TREE_VECTOR_CST_ELTS (arg1);
1855 if (!operand_equal_p (v1, v2, only_const))
1857 v1 = TREE_CHAIN (v1);
1858 v2 = TREE_CHAIN (v2);
1865 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
1867 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
1871 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
1872 && ! memcmp (TREE_STRING_POINTER (arg0),
1873 TREE_STRING_POINTER (arg1),
1874 TREE_STRING_LENGTH (arg0)));
1877 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
1886 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
1889 /* Two conversions are equal only if signedness and modes match. */
1890 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
1891 && (TREE_UNSIGNED (TREE_TYPE (arg0))
1892 != TREE_UNSIGNED (TREE_TYPE (arg1))))
1895 return operand_equal_p (TREE_OPERAND (arg0, 0),
1896 TREE_OPERAND (arg1, 0), 0);
1900 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
1901 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
1905 /* For commutative ops, allow the other order. */
1906 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
1907 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
1908 || TREE_CODE (arg0) == BIT_IOR_EXPR
1909 || TREE_CODE (arg0) == BIT_XOR_EXPR
1910 || TREE_CODE (arg0) == BIT_AND_EXPR
1911 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
1912 && operand_equal_p (TREE_OPERAND (arg0, 0),
1913 TREE_OPERAND (arg1, 1), 0)
1914 && operand_equal_p (TREE_OPERAND (arg0, 1),
1915 TREE_OPERAND (arg1, 0), 0));
1918 /* If either of the pointer (or reference) expressions we are
1919 dereferencing contain a side effect, these cannot be equal. */
1920 if (TREE_SIDE_EFFECTS (arg0)
1921 || TREE_SIDE_EFFECTS (arg1))
1924 switch (TREE_CODE (arg0))
1927 return operand_equal_p (TREE_OPERAND (arg0, 0),
1928 TREE_OPERAND (arg1, 0), 0);
1932 case ARRAY_RANGE_REF:
1933 return (operand_equal_p (TREE_OPERAND (arg0, 0),
1934 TREE_OPERAND (arg1, 0), 0)
1935 && operand_equal_p (TREE_OPERAND (arg0, 1),
1936 TREE_OPERAND (arg1, 1), 0));
1939 return (operand_equal_p (TREE_OPERAND (arg0, 0),
1940 TREE_OPERAND (arg1, 0), 0)
1941 && operand_equal_p (TREE_OPERAND (arg0, 1),
1942 TREE_OPERAND (arg1, 1), 0)
1943 && operand_equal_p (TREE_OPERAND (arg0, 2),
1944 TREE_OPERAND (arg1, 2), 0));
1950 switch (TREE_CODE (arg0))
1953 case TRUTH_NOT_EXPR:
1954 return operand_equal_p (TREE_OPERAND (arg0, 0),
1955 TREE_OPERAND (arg1, 0), 0);
1958 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
1961 /* If the CALL_EXPRs call different functions, then they
1962 clearly can not be equal. */
1963 if (! operand_equal_p (TREE_OPERAND (arg0, 0),
1964 TREE_OPERAND (arg1, 0), 0))
1967 /* Only consider const functions equivalent. */
1968 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == ADDR_EXPR)
1970 tree fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
1971 if (! (flags_from_decl_or_type (fndecl) & ECF_CONST))
1977 /* Now see if all the arguments are the same. operand_equal_p
1978 does not handle TREE_LIST, so we walk the operands here
1979 feeding them to operand_equal_p. */
1980 arg0 = TREE_OPERAND (arg0, 1);
1981 arg1 = TREE_OPERAND (arg1, 1);
1982 while (arg0 && arg1)
1984 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1), 0))
1987 arg0 = TREE_CHAIN (arg0);
1988 arg1 = TREE_CHAIN (arg1);
1991 /* If we get here and both argument lists are exhausted
1992 then the CALL_EXPRs are equal. */
1993 return ! (arg0 || arg1);
2000 /* Consider __builtin_sqrt equal to sqrt. */
2001 return TREE_CODE (arg0) == FUNCTION_DECL
2002 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2003 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2004 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1);
2011 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2012 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2014 When in doubt, return 0. */
2017 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2019 int unsignedp1, unsignedpo;
2020 tree primarg0, primarg1, primother;
2021 unsigned int correct_width;
2023 if (operand_equal_p (arg0, arg1, 0))
2026 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2027 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2030 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2031 and see if the inner values are the same. This removes any
2032 signedness comparison, which doesn't matter here. */
2033 primarg0 = arg0, primarg1 = arg1;
2034 STRIP_NOPS (primarg0);
2035 STRIP_NOPS (primarg1);
2036 if (operand_equal_p (primarg0, primarg1, 0))
2039 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2040 actual comparison operand, ARG0.
2042 First throw away any conversions to wider types
2043 already present in the operands. */
2045 primarg1 = get_narrower (arg1, &unsignedp1);
2046 primother = get_narrower (other, &unsignedpo);
2048 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2049 if (unsignedp1 == unsignedpo
2050 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2051 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2053 tree type = TREE_TYPE (arg0);
2055 /* Make sure shorter operand is extended the right way
2056 to match the longer operand. */
2057 primarg1 = convert ((*lang_hooks.types.signed_or_unsigned_type)
2058 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2060 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2067 /* See if ARG is an expression that is either a comparison or is performing
2068 arithmetic on comparisons. The comparisons must only be comparing
2069 two different values, which will be stored in *CVAL1 and *CVAL2; if
2070 they are nonzero it means that some operands have already been found.
2071 No variables may be used anywhere else in the expression except in the
2072 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2073 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2075 If this is true, return 1. Otherwise, return zero. */
2078 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2080 enum tree_code code = TREE_CODE (arg);
2081 char class = TREE_CODE_CLASS (code);
2083 /* We can handle some of the 'e' cases here. */
2084 if (class == 'e' && code == TRUTH_NOT_EXPR)
2086 else if (class == 'e'
2087 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2088 || code == COMPOUND_EXPR))
2091 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2092 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2094 /* If we've already found a CVAL1 or CVAL2, this expression is
2095 two complex to handle. */
2096 if (*cval1 || *cval2)
2106 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2109 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2110 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2111 cval1, cval2, save_p));
2117 if (code == COND_EXPR)
2118 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2119 cval1, cval2, save_p)
2120 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2121 cval1, cval2, save_p)
2122 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2123 cval1, cval2, save_p));
2127 /* First see if we can handle the first operand, then the second. For
2128 the second operand, we know *CVAL1 can't be zero. It must be that
2129 one side of the comparison is each of the values; test for the
2130 case where this isn't true by failing if the two operands
2133 if (operand_equal_p (TREE_OPERAND (arg, 0),
2134 TREE_OPERAND (arg, 1), 0))
2138 *cval1 = TREE_OPERAND (arg, 0);
2139 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2141 else if (*cval2 == 0)
2142 *cval2 = TREE_OPERAND (arg, 0);
2143 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2148 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2150 else if (*cval2 == 0)
2151 *cval2 = TREE_OPERAND (arg, 1);
2152 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2164 /* ARG is a tree that is known to contain just arithmetic operations and
2165 comparisons. Evaluate the operations in the tree substituting NEW0 for
2166 any occurrence of OLD0 as an operand of a comparison and likewise for
2170 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2172 tree type = TREE_TYPE (arg);
2173 enum tree_code code = TREE_CODE (arg);
2174 char class = TREE_CODE_CLASS (code);
2176 /* We can handle some of the 'e' cases here. */
2177 if (class == 'e' && code == TRUTH_NOT_EXPR)
2179 else if (class == 'e'
2180 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2186 return fold (build1 (code, type,
2187 eval_subst (TREE_OPERAND (arg, 0),
2188 old0, new0, old1, new1)));
2191 return fold (build (code, type,
2192 eval_subst (TREE_OPERAND (arg, 0),
2193 old0, new0, old1, new1),
2194 eval_subst (TREE_OPERAND (arg, 1),
2195 old0, new0, old1, new1)));
2201 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2204 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2207 return fold (build (code, type,
2208 eval_subst (TREE_OPERAND (arg, 0),
2209 old0, new0, old1, new1),
2210 eval_subst (TREE_OPERAND (arg, 1),
2211 old0, new0, old1, new1),
2212 eval_subst (TREE_OPERAND (arg, 2),
2213 old0, new0, old1, new1)));
2217 /* Fall through - ??? */
2221 tree arg0 = TREE_OPERAND (arg, 0);
2222 tree arg1 = TREE_OPERAND (arg, 1);
2224 /* We need to check both for exact equality and tree equality. The
2225 former will be true if the operand has a side-effect. In that
2226 case, we know the operand occurred exactly once. */
2228 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2230 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2233 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2235 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2238 return fold (build (code, type, arg0, arg1));
2246 /* Return a tree for the case when the result of an expression is RESULT
2247 converted to TYPE and OMITTED was previously an operand of the expression
2248 but is now not needed (e.g., we folded OMITTED * 0).
2250 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2251 the conversion of RESULT to TYPE. */
2254 omit_one_operand (tree type, tree result, tree omitted)
2256 tree t = convert (type, result);
2258 if (TREE_SIDE_EFFECTS (omitted))
2259 return build (COMPOUND_EXPR, type, omitted, t);
2261 return non_lvalue (t);
2264 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2267 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2269 tree t = convert (type, result);
2271 if (TREE_SIDE_EFFECTS (omitted))
2272 return build (COMPOUND_EXPR, type, omitted, t);
2274 return pedantic_non_lvalue (t);
2277 /* Return a simplified tree node for the truth-negation of ARG. This
2278 never alters ARG itself. We assume that ARG is an operation that
2279 returns a truth value (0 or 1). */
2282 invert_truthvalue (tree arg)
2284 tree type = TREE_TYPE (arg);
2285 enum tree_code code = TREE_CODE (arg);
2287 if (code == ERROR_MARK)
2290 /* If this is a comparison, we can simply invert it, except for
2291 floating-point non-equality comparisons, in which case we just
2292 enclose a TRUTH_NOT_EXPR around what we have. */
2294 if (TREE_CODE_CLASS (code) == '<')
2296 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2297 && !flag_unsafe_math_optimizations
2300 return build1 (TRUTH_NOT_EXPR, type, arg);
2302 return build (invert_tree_comparison (code), type,
2303 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2309 return convert (type, build_int_2 (integer_zerop (arg), 0));
2311 case TRUTH_AND_EXPR:
2312 return build (TRUTH_OR_EXPR, type,
2313 invert_truthvalue (TREE_OPERAND (arg, 0)),
2314 invert_truthvalue (TREE_OPERAND (arg, 1)));
2317 return build (TRUTH_AND_EXPR, type,
2318 invert_truthvalue (TREE_OPERAND (arg, 0)),
2319 invert_truthvalue (TREE_OPERAND (arg, 1)));
2321 case TRUTH_XOR_EXPR:
2322 /* Here we can invert either operand. We invert the first operand
2323 unless the second operand is a TRUTH_NOT_EXPR in which case our
2324 result is the XOR of the first operand with the inside of the
2325 negation of the second operand. */
2327 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2328 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2329 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2331 return build (TRUTH_XOR_EXPR, type,
2332 invert_truthvalue (TREE_OPERAND (arg, 0)),
2333 TREE_OPERAND (arg, 1));
2335 case TRUTH_ANDIF_EXPR:
2336 return build (TRUTH_ORIF_EXPR, type,
2337 invert_truthvalue (TREE_OPERAND (arg, 0)),
2338 invert_truthvalue (TREE_OPERAND (arg, 1)));
2340 case TRUTH_ORIF_EXPR:
2341 return build (TRUTH_ANDIF_EXPR, type,
2342 invert_truthvalue (TREE_OPERAND (arg, 0)),
2343 invert_truthvalue (TREE_OPERAND (arg, 1)));
2345 case TRUTH_NOT_EXPR:
2346 return TREE_OPERAND (arg, 0);
2349 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2350 invert_truthvalue (TREE_OPERAND (arg, 1)),
2351 invert_truthvalue (TREE_OPERAND (arg, 2)));
2354 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2355 invert_truthvalue (TREE_OPERAND (arg, 1)));
2357 case WITH_RECORD_EXPR:
2358 return build (WITH_RECORD_EXPR, type,
2359 invert_truthvalue (TREE_OPERAND (arg, 0)),
2360 TREE_OPERAND (arg, 1));
2362 case NON_LVALUE_EXPR:
2363 return invert_truthvalue (TREE_OPERAND (arg, 0));
2368 return build1 (TREE_CODE (arg), type,
2369 invert_truthvalue (TREE_OPERAND (arg, 0)));
2372 if (!integer_onep (TREE_OPERAND (arg, 1)))
2374 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2377 return build1 (TRUTH_NOT_EXPR, type, arg);
2379 case CLEANUP_POINT_EXPR:
2380 return build1 (CLEANUP_POINT_EXPR, type,
2381 invert_truthvalue (TREE_OPERAND (arg, 0)));
2386 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2388 return build1 (TRUTH_NOT_EXPR, type, arg);
2391 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2392 operands are another bit-wise operation with a common input. If so,
2393 distribute the bit operations to save an operation and possibly two if
2394 constants are involved. For example, convert
2395 (A | B) & (A | C) into A | (B & C)
2396 Further simplification will occur if B and C are constants.
2398 If this optimization cannot be done, 0 will be returned. */
2401 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
2406 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2407 || TREE_CODE (arg0) == code
2408 || (TREE_CODE (arg0) != BIT_AND_EXPR
2409 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2412 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2414 common = TREE_OPERAND (arg0, 0);
2415 left = TREE_OPERAND (arg0, 1);
2416 right = TREE_OPERAND (arg1, 1);
2418 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2420 common = TREE_OPERAND (arg0, 0);
2421 left = TREE_OPERAND (arg0, 1);
2422 right = TREE_OPERAND (arg1, 0);
2424 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2426 common = TREE_OPERAND (arg0, 1);
2427 left = TREE_OPERAND (arg0, 0);
2428 right = TREE_OPERAND (arg1, 1);
2430 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2432 common = TREE_OPERAND (arg0, 1);
2433 left = TREE_OPERAND (arg0, 0);
2434 right = TREE_OPERAND (arg1, 0);
2439 return fold (build (TREE_CODE (arg0), type, common,
2440 fold (build (code, type, left, right))));
2443 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2444 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2447 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
2450 tree result = build (BIT_FIELD_REF, type, inner,
2451 size_int (bitsize), bitsize_int (bitpos));
2453 TREE_UNSIGNED (result) = unsignedp;
2458 /* Optimize a bit-field compare.
2460 There are two cases: First is a compare against a constant and the
2461 second is a comparison of two items where the fields are at the same
2462 bit position relative to the start of a chunk (byte, halfword, word)
2463 large enough to contain it. In these cases we can avoid the shift
2464 implicit in bitfield extractions.
2466 For constants, we emit a compare of the shifted constant with the
2467 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2468 compared. For two fields at the same position, we do the ANDs with the
2469 similar mask and compare the result of the ANDs.
2471 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2472 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2473 are the left and right operands of the comparison, respectively.
2475 If the optimization described above can be done, we return the resulting
2476 tree. Otherwise we return zero. */
2479 optimize_bit_field_compare (enum tree_code code, tree compare_type,
2482 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2483 tree type = TREE_TYPE (lhs);
2484 tree signed_type, unsigned_type;
2485 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2486 enum machine_mode lmode, rmode, nmode;
2487 int lunsignedp, runsignedp;
2488 int lvolatilep = 0, rvolatilep = 0;
2489 tree linner, rinner = NULL_TREE;
2493 /* Get all the information about the extractions being done. If the bit size
2494 if the same as the size of the underlying object, we aren't doing an
2495 extraction at all and so can do nothing. We also don't want to
2496 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2497 then will no longer be able to replace it. */
2498 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2499 &lunsignedp, &lvolatilep);
2500 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2501 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2506 /* If this is not a constant, we can only do something if bit positions,
2507 sizes, and signedness are the same. */
2508 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2509 &runsignedp, &rvolatilep);
2511 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2512 || lunsignedp != runsignedp || offset != 0
2513 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2517 /* See if we can find a mode to refer to this field. We should be able to,
2518 but fail if we can't. */
2519 nmode = get_best_mode (lbitsize, lbitpos,
2520 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2521 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2522 TYPE_ALIGN (TREE_TYPE (rinner))),
2523 word_mode, lvolatilep || rvolatilep);
2524 if (nmode == VOIDmode)
2527 /* Set signed and unsigned types of the precision of this mode for the
2529 signed_type = (*lang_hooks.types.type_for_mode) (nmode, 0);
2530 unsigned_type = (*lang_hooks.types.type_for_mode) (nmode, 1);
2532 /* Compute the bit position and size for the new reference and our offset
2533 within it. If the new reference is the same size as the original, we
2534 won't optimize anything, so return zero. */
2535 nbitsize = GET_MODE_BITSIZE (nmode);
2536 nbitpos = lbitpos & ~ (nbitsize - 1);
2538 if (nbitsize == lbitsize)
2541 if (BYTES_BIG_ENDIAN)
2542 lbitpos = nbitsize - lbitsize - lbitpos;
2544 /* Make the mask to be used against the extracted field. */
2545 mask = build_int_2 (~0, ~0);
2546 TREE_TYPE (mask) = unsigned_type;
2547 force_fit_type (mask, 0);
2548 mask = convert (unsigned_type, mask);
2549 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2550 mask = const_binop (RSHIFT_EXPR, mask,
2551 size_int (nbitsize - lbitsize - lbitpos), 0);
2554 /* If not comparing with constant, just rework the comparison
2556 return build (code, compare_type,
2557 build (BIT_AND_EXPR, unsigned_type,
2558 make_bit_field_ref (linner, unsigned_type,
2559 nbitsize, nbitpos, 1),
2561 build (BIT_AND_EXPR, unsigned_type,
2562 make_bit_field_ref (rinner, unsigned_type,
2563 nbitsize, nbitpos, 1),
2566 /* Otherwise, we are handling the constant case. See if the constant is too
2567 big for the field. Warn and return a tree of for 0 (false) if so. We do
2568 this not only for its own sake, but to avoid having to test for this
2569 error case below. If we didn't, we might generate wrong code.
2571 For unsigned fields, the constant shifted right by the field length should
2572 be all zero. For signed fields, the high-order bits should agree with
2577 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2578 convert (unsigned_type, rhs),
2579 size_int (lbitsize), 0)))
2581 warning ("comparison is always %d due to width of bit-field",
2583 return convert (compare_type,
2585 ? integer_one_node : integer_zero_node));
2590 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
2591 size_int (lbitsize - 1), 0);
2592 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2594 warning ("comparison is always %d due to width of bit-field",
2596 return convert (compare_type,
2598 ? integer_one_node : integer_zero_node));
2602 /* Single-bit compares should always be against zero. */
2603 if (lbitsize == 1 && ! integer_zerop (rhs))
2605 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2606 rhs = convert (type, integer_zero_node);
2609 /* Make a new bitfield reference, shift the constant over the
2610 appropriate number of bits and mask it with the computed mask
2611 (in case this was a signed field). If we changed it, make a new one. */
2612 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
2615 TREE_SIDE_EFFECTS (lhs) = 1;
2616 TREE_THIS_VOLATILE (lhs) = 1;
2619 rhs = fold (const_binop (BIT_AND_EXPR,
2620 const_binop (LSHIFT_EXPR,
2621 convert (unsigned_type, rhs),
2622 size_int (lbitpos), 0),
2625 return build (code, compare_type,
2626 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2630 /* Subroutine for fold_truthop: decode a field reference.
2632 If EXP is a comparison reference, we return the innermost reference.
2634 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2635 set to the starting bit number.
2637 If the innermost field can be completely contained in a mode-sized
2638 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2640 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2641 otherwise it is not changed.
2643 *PUNSIGNEDP is set to the signedness of the field.
2645 *PMASK is set to the mask used. This is either contained in a
2646 BIT_AND_EXPR or derived from the width of the field.
2648 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2650 Return 0 if this is not a component reference or is one that we can't
2651 do anything with. */
2654 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
2655 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
2656 int *punsignedp, int *pvolatilep,
2657 tree *pmask, tree *pand_mask)
2659 tree outer_type = 0;
2661 tree mask, inner, offset;
2663 unsigned int precision;
2665 /* All the optimizations using this function assume integer fields.
2666 There are problems with FP fields since the type_for_size call
2667 below can fail for, e.g., XFmode. */
2668 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
2671 /* We are interested in the bare arrangement of bits, so strip everything
2672 that doesn't affect the machine mode. However, record the type of the
2673 outermost expression if it may matter below. */
2674 if (TREE_CODE (exp) == NOP_EXPR
2675 || TREE_CODE (exp) == CONVERT_EXPR
2676 || TREE_CODE (exp) == NON_LVALUE_EXPR)
2677 outer_type = TREE_TYPE (exp);
2680 if (TREE_CODE (exp) == BIT_AND_EXPR)
2682 and_mask = TREE_OPERAND (exp, 1);
2683 exp = TREE_OPERAND (exp, 0);
2684 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
2685 if (TREE_CODE (and_mask) != INTEGER_CST)
2689 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
2690 punsignedp, pvolatilep);
2691 if ((inner == exp && and_mask == 0)
2692 || *pbitsize < 0 || offset != 0
2693 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
2696 /* If the number of bits in the reference is the same as the bitsize of
2697 the outer type, then the outer type gives the signedness. Otherwise
2698 (in case of a small bitfield) the signedness is unchanged. */
2699 if (outer_type && *pbitsize == tree_low_cst (TYPE_SIZE (outer_type), 1))
2700 *punsignedp = TREE_UNSIGNED (outer_type);
2702 /* Compute the mask to access the bitfield. */
2703 unsigned_type = (*lang_hooks.types.type_for_size) (*pbitsize, 1);
2704 precision = TYPE_PRECISION (unsigned_type);
2706 mask = build_int_2 (~0, ~0);
2707 TREE_TYPE (mask) = unsigned_type;
2708 force_fit_type (mask, 0);
2709 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2710 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2712 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
2714 mask = fold (build (BIT_AND_EXPR, unsigned_type,
2715 convert (unsigned_type, and_mask), mask));
2718 *pand_mask = and_mask;
2722 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
2726 all_ones_mask_p (tree mask, int size)
2728 tree type = TREE_TYPE (mask);
2729 unsigned int precision = TYPE_PRECISION (type);
2732 tmask = build_int_2 (~0, ~0);
2733 TREE_TYPE (tmask) = (*lang_hooks.types.signed_type) (type);
2734 force_fit_type (tmask, 0);
2736 tree_int_cst_equal (mask,
2737 const_binop (RSHIFT_EXPR,
2738 const_binop (LSHIFT_EXPR, tmask,
2739 size_int (precision - size),
2741 size_int (precision - size), 0));
2744 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
2745 represents the sign bit of EXP's type. If EXP represents a sign
2746 or zero extension, also test VAL against the unextended type.
2747 The return value is the (sub)expression whose sign bit is VAL,
2748 or NULL_TREE otherwise. */
2751 sign_bit_p (tree exp, tree val)
2753 unsigned HOST_WIDE_INT mask_lo, lo;
2754 HOST_WIDE_INT mask_hi, hi;
2758 /* Tree EXP must have an integral type. */
2759 t = TREE_TYPE (exp);
2760 if (! INTEGRAL_TYPE_P (t))
2763 /* Tree VAL must be an integer constant. */
2764 if (TREE_CODE (val) != INTEGER_CST
2765 || TREE_CONSTANT_OVERFLOW (val))
2768 width = TYPE_PRECISION (t);
2769 if (width > HOST_BITS_PER_WIDE_INT)
2771 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
2774 mask_hi = ((unsigned HOST_WIDE_INT) -1
2775 >> (2 * HOST_BITS_PER_WIDE_INT - width));
2781 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
2784 mask_lo = ((unsigned HOST_WIDE_INT) -1
2785 >> (HOST_BITS_PER_WIDE_INT - width));
2788 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
2789 treat VAL as if it were unsigned. */
2790 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
2791 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
2794 /* Handle extension from a narrower type. */
2795 if (TREE_CODE (exp) == NOP_EXPR
2796 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
2797 return sign_bit_p (TREE_OPERAND (exp, 0), val);
2802 /* Subroutine for fold_truthop: determine if an operand is simple enough
2803 to be evaluated unconditionally. */
2806 simple_operand_p (tree exp)
2808 /* Strip any conversions that don't change the machine mode. */
2809 while ((TREE_CODE (exp) == NOP_EXPR
2810 || TREE_CODE (exp) == CONVERT_EXPR)
2811 && (TYPE_MODE (TREE_TYPE (exp))
2812 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
2813 exp = TREE_OPERAND (exp, 0);
2815 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
2817 && ! TREE_ADDRESSABLE (exp)
2818 && ! TREE_THIS_VOLATILE (exp)
2819 && ! DECL_NONLOCAL (exp)
2820 /* Don't regard global variables as simple. They may be
2821 allocated in ways unknown to the compiler (shared memory,
2822 #pragma weak, etc). */
2823 && ! TREE_PUBLIC (exp)
2824 && ! DECL_EXTERNAL (exp)
2825 /* Loading a static variable is unduly expensive, but global
2826 registers aren't expensive. */
2827 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
2830 /* The following functions are subroutines to fold_range_test and allow it to
2831 try to change a logical combination of comparisons into a range test.
2834 X == 2 || X == 3 || X == 4 || X == 5
2838 (unsigned) (X - 2) <= 3
2840 We describe each set of comparisons as being either inside or outside
2841 a range, using a variable named like IN_P, and then describe the
2842 range with a lower and upper bound. If one of the bounds is omitted,
2843 it represents either the highest or lowest value of the type.
2845 In the comments below, we represent a range by two numbers in brackets
2846 preceded by a "+" to designate being inside that range, or a "-" to
2847 designate being outside that range, so the condition can be inverted by
2848 flipping the prefix. An omitted bound is represented by a "-". For
2849 example, "- [-, 10]" means being outside the range starting at the lowest
2850 possible value and ending at 10, in other words, being greater than 10.
2851 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
2854 We set up things so that the missing bounds are handled in a consistent
2855 manner so neither a missing bound nor "true" and "false" need to be
2856 handled using a special case. */
2858 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
2859 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
2860 and UPPER1_P are nonzero if the respective argument is an upper bound
2861 and zero for a lower. TYPE, if nonzero, is the type of the result; it
2862 must be specified for a comparison. ARG1 will be converted to ARG0's
2863 type if both are specified. */
2866 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
2867 tree arg1, int upper1_p)
2873 /* If neither arg represents infinity, do the normal operation.
2874 Else, if not a comparison, return infinity. Else handle the special
2875 comparison rules. Note that most of the cases below won't occur, but
2876 are handled for consistency. */
2878 if (arg0 != 0 && arg1 != 0)
2880 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
2881 arg0, convert (TREE_TYPE (arg0), arg1)));
2883 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
2886 if (TREE_CODE_CLASS (code) != '<')
2889 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
2890 for neither. In real maths, we cannot assume open ended ranges are
2891 the same. But, this is computer arithmetic, where numbers are finite.
2892 We can therefore make the transformation of any unbounded range with
2893 the value Z, Z being greater than any representable number. This permits
2894 us to treat unbounded ranges as equal. */
2895 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
2896 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
2900 result = sgn0 == sgn1;
2903 result = sgn0 != sgn1;
2906 result = sgn0 < sgn1;
2909 result = sgn0 <= sgn1;
2912 result = sgn0 > sgn1;
2915 result = sgn0 >= sgn1;
2921 return convert (type, result ? integer_one_node : integer_zero_node);
2924 /* Given EXP, a logical expression, set the range it is testing into
2925 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
2926 actually being tested. *PLOW and *PHIGH will be made of the same type
2927 as the returned expression. If EXP is not a comparison, we will most
2928 likely not be returning a useful value and range. */
2931 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
2933 enum tree_code code;
2934 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
2935 tree orig_type = NULL_TREE;
2937 tree low, high, n_low, n_high;
2939 /* Start with simply saying "EXP != 0" and then look at the code of EXP
2940 and see if we can refine the range. Some of the cases below may not
2941 happen, but it doesn't seem worth worrying about this. We "continue"
2942 the outer loop when we've changed something; otherwise we "break"
2943 the switch, which will "break" the while. */
2945 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
2949 code = TREE_CODE (exp);
2951 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
2953 if (first_rtl_op (code) > 0)
2954 arg0 = TREE_OPERAND (exp, 0);
2955 if (TREE_CODE_CLASS (code) == '<'
2956 || TREE_CODE_CLASS (code) == '1'
2957 || TREE_CODE_CLASS (code) == '2')
2958 type = TREE_TYPE (arg0);
2959 if (TREE_CODE_CLASS (code) == '2'
2960 || TREE_CODE_CLASS (code) == '<'
2961 || (TREE_CODE_CLASS (code) == 'e'
2962 && TREE_CODE_LENGTH (code) > 1))
2963 arg1 = TREE_OPERAND (exp, 1);
2966 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
2967 lose a cast by accident. */
2968 if (type != NULL_TREE && orig_type == NULL_TREE)
2973 case TRUTH_NOT_EXPR:
2974 in_p = ! in_p, exp = arg0;
2977 case EQ_EXPR: case NE_EXPR:
2978 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
2979 /* We can only do something if the range is testing for zero
2980 and if the second operand is an integer constant. Note that
2981 saying something is "in" the range we make is done by
2982 complementing IN_P since it will set in the initial case of
2983 being not equal to zero; "out" is leaving it alone. */
2984 if (low == 0 || high == 0
2985 || ! integer_zerop (low) || ! integer_zerop (high)
2986 || TREE_CODE (arg1) != INTEGER_CST)
2991 case NE_EXPR: /* - [c, c] */
2994 case EQ_EXPR: /* + [c, c] */
2995 in_p = ! in_p, low = high = arg1;
2997 case GT_EXPR: /* - [-, c] */
2998 low = 0, high = arg1;
3000 case GE_EXPR: /* + [c, -] */
3001 in_p = ! in_p, low = arg1, high = 0;
3003 case LT_EXPR: /* - [c, -] */
3004 low = arg1, high = 0;
3006 case LE_EXPR: /* + [-, c] */
3007 in_p = ! in_p, low = 0, high = arg1;
3015 /* If this is an unsigned comparison, we also know that EXP is
3016 greater than or equal to zero. We base the range tests we make
3017 on that fact, so we record it here so we can parse existing
3019 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3021 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3022 1, convert (type, integer_zero_node),
3026 in_p = n_in_p, low = n_low, high = n_high;
3028 /* If the high bound is missing, but we
3029 have a low bound, reverse the range so
3030 it goes from zero to the low bound minus 1. */
3031 if (high == 0 && low)
3034 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3035 integer_one_node, 0);
3036 low = convert (type, integer_zero_node);
3042 /* (-x) IN [a,b] -> x in [-b, -a] */
3043 n_low = range_binop (MINUS_EXPR, type,
3044 convert (type, integer_zero_node), 0, high, 1);
3045 n_high = range_binop (MINUS_EXPR, type,
3046 convert (type, integer_zero_node), 0, low, 0);
3047 low = n_low, high = n_high;
3053 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3054 convert (type, integer_one_node));
3057 case PLUS_EXPR: case MINUS_EXPR:
3058 if (TREE_CODE (arg1) != INTEGER_CST)
3061 /* If EXP is signed, any overflow in the computation is undefined,
3062 so we don't worry about it so long as our computations on
3063 the bounds don't overflow. For unsigned, overflow is defined
3064 and this is exactly the right thing. */
3065 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3066 type, low, 0, arg1, 0);
3067 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3068 type, high, 1, arg1, 0);
3069 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3070 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3073 /* Check for an unsigned range which has wrapped around the maximum
3074 value thus making n_high < n_low, and normalize it. */
3075 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3077 low = range_binop (PLUS_EXPR, type, n_high, 0,
3078 integer_one_node, 0);
3079 high = range_binop (MINUS_EXPR, type, n_low, 0,
3080 integer_one_node, 0);
3082 /* If the range is of the form +/- [ x+1, x ], we won't
3083 be able to normalize it. But then, it represents the
3084 whole range or the empty set, so make it
3086 if (tree_int_cst_equal (n_low, low)
3087 && tree_int_cst_equal (n_high, high))
3093 low = n_low, high = n_high;
3098 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3099 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3102 if (! INTEGRAL_TYPE_P (type)
3103 || (low != 0 && ! int_fits_type_p (low, type))
3104 || (high != 0 && ! int_fits_type_p (high, type)))
3107 n_low = low, n_high = high;
3110 n_low = convert (type, n_low);
3113 n_high = convert (type, n_high);
3115 /* If we're converting from an unsigned to a signed type,
3116 we will be doing the comparison as unsigned. The tests above
3117 have already verified that LOW and HIGH are both positive.
3119 So we have to make sure that the original unsigned value will
3120 be interpreted as positive. */
3121 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3123 tree equiv_type = (*lang_hooks.types.type_for_mode)
3124 (TYPE_MODE (type), 1);
3127 /* A range without an upper bound is, naturally, unbounded.
3128 Since convert would have cropped a very large value, use
3129 the max value for the destination type. */
3131 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3132 : TYPE_MAX_VALUE (type);
3134 if (TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (exp)))
3135 high_positive = fold (build (RSHIFT_EXPR, type,
3136 convert (type, high_positive),
3137 convert (type, integer_one_node)));
3139 /* If the low bound is specified, "and" the range with the
3140 range for which the original unsigned value will be
3144 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3146 1, convert (type, integer_zero_node),
3150 in_p = (n_in_p == in_p);
3154 /* Otherwise, "or" the range with the range of the input
3155 that will be interpreted as negative. */
3156 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3158 1, convert (type, integer_zero_node),
3162 in_p = (in_p != n_in_p);
3167 low = n_low, high = n_high;
3177 /* If EXP is a constant, we can evaluate whether this is true or false. */
3178 if (TREE_CODE (exp) == INTEGER_CST)
3180 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3182 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3188 *pin_p = in_p, *plow = low, *phigh = high;
3192 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3193 type, TYPE, return an expression to test if EXP is in (or out of, depending
3194 on IN_P) the range. */
3197 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3199 tree etype = TREE_TYPE (exp);
3203 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3204 return invert_truthvalue (value);
3206 if (low == 0 && high == 0)
3207 return convert (type, integer_one_node);
3210 return fold (build (LE_EXPR, type, exp, high));
3213 return fold (build (GE_EXPR, type, exp, low));
3215 if (operand_equal_p (low, high, 0))
3216 return fold (build (EQ_EXPR, type, exp, low));
3218 if (integer_zerop (low))
3220 if (! TREE_UNSIGNED (etype))
3222 etype = (*lang_hooks.types.unsigned_type) (etype);
3223 high = convert (etype, high);
3224 exp = convert (etype, exp);
3226 return build_range_check (type, exp, 1, 0, high);
3229 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3230 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3232 unsigned HOST_WIDE_INT lo;
3236 prec = TYPE_PRECISION (etype);
3237 if (prec <= HOST_BITS_PER_WIDE_INT)
3240 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3244 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3245 lo = (unsigned HOST_WIDE_INT) -1;
3248 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3250 if (TREE_UNSIGNED (etype))
3252 etype = (*lang_hooks.types.signed_type) (etype);
3253 exp = convert (etype, exp);
3255 return fold (build (GT_EXPR, type, exp,
3256 convert (etype, integer_zero_node)));
3260 if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3261 && ! TREE_OVERFLOW (value))
3262 return build_range_check (type,
3263 fold (build (MINUS_EXPR, etype, exp, low)),
3264 1, convert (etype, integer_zero_node), value);
3269 /* Given two ranges, see if we can merge them into one. Return 1 if we
3270 can, 0 if we can't. Set the output range into the specified parameters. */
3273 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
3274 tree high0, int in1_p, tree low1, tree high1)
3282 int lowequal = ((low0 == 0 && low1 == 0)
3283 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3284 low0, 0, low1, 0)));
3285 int highequal = ((high0 == 0 && high1 == 0)
3286 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3287 high0, 1, high1, 1)));
3289 /* Make range 0 be the range that starts first, or ends last if they
3290 start at the same value. Swap them if it isn't. */
3291 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3294 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3295 high1, 1, high0, 1))))
3297 temp = in0_p, in0_p = in1_p, in1_p = temp;
3298 tem = low0, low0 = low1, low1 = tem;
3299 tem = high0, high0 = high1, high1 = tem;
3302 /* Now flag two cases, whether the ranges are disjoint or whether the
3303 second range is totally subsumed in the first. Note that the tests
3304 below are simplified by the ones above. */
3305 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3306 high0, 1, low1, 0));
3307 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3308 high1, 1, high0, 1));
3310 /* We now have four cases, depending on whether we are including or
3311 excluding the two ranges. */
3314 /* If they don't overlap, the result is false. If the second range
3315 is a subset it is the result. Otherwise, the range is from the start
3316 of the second to the end of the first. */
3318 in_p = 0, low = high = 0;
3320 in_p = 1, low = low1, high = high1;
3322 in_p = 1, low = low1, high = high0;
3325 else if (in0_p && ! in1_p)
3327 /* If they don't overlap, the result is the first range. If they are
3328 equal, the result is false. If the second range is a subset of the
3329 first, and the ranges begin at the same place, we go from just after
3330 the end of the first range to the end of the second. If the second
3331 range is not a subset of the first, or if it is a subset and both
3332 ranges end at the same place, the range starts at the start of the
3333 first range and ends just before the second range.
3334 Otherwise, we can't describe this as a single range. */
3336 in_p = 1, low = low0, high = high0;
3337 else if (lowequal && highequal)
3338 in_p = 0, low = high = 0;
3339 else if (subset && lowequal)
3341 in_p = 1, high = high0;
3342 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3343 integer_one_node, 0);
3345 else if (! subset || highequal)
3347 in_p = 1, low = low0;
3348 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3349 integer_one_node, 0);
3355 else if (! in0_p && in1_p)
3357 /* If they don't overlap, the result is the second range. If the second
3358 is a subset of the first, the result is false. Otherwise,
3359 the range starts just after the first range and ends at the
3360 end of the second. */
3362 in_p = 1, low = low1, high = high1;
3363 else if (subset || highequal)
3364 in_p = 0, low = high = 0;
3367 in_p = 1, high = high1;
3368 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3369 integer_one_node, 0);
3375 /* The case where we are excluding both ranges. Here the complex case
3376 is if they don't overlap. In that case, the only time we have a
3377 range is if they are adjacent. If the second is a subset of the
3378 first, the result is the first. Otherwise, the range to exclude
3379 starts at the beginning of the first range and ends at the end of the
3383 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3384 range_binop (PLUS_EXPR, NULL_TREE,
3386 integer_one_node, 1),
3388 in_p = 0, low = low0, high = high1;
3393 in_p = 0, low = low0, high = high0;
3395 in_p = 0, low = low0, high = high1;
3398 *pin_p = in_p, *plow = low, *phigh = high;
3402 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
3403 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
3406 /* EXP is some logical combination of boolean tests. See if we can
3407 merge it into some range test. Return the new tree if so. */
3410 fold_range_test (tree exp)
3412 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3413 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3414 int in0_p, in1_p, in_p;
3415 tree low0, low1, low, high0, high1, high;
3416 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3417 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3420 /* If this is an OR operation, invert both sides; we will invert
3421 again at the end. */
3423 in0_p = ! in0_p, in1_p = ! in1_p;
3425 /* If both expressions are the same, if we can merge the ranges, and we
3426 can build the range test, return it or it inverted. If one of the
3427 ranges is always true or always false, consider it to be the same
3428 expression as the other. */
3429 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3430 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3432 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3434 : rhs != 0 ? rhs : integer_zero_node,
3436 return or_op ? invert_truthvalue (tem) : tem;
3438 /* On machines where the branch cost is expensive, if this is a
3439 short-circuited branch and the underlying object on both sides
3440 is the same, make a non-short-circuit operation. */
3441 else if (RANGE_TEST_NON_SHORT_CIRCUIT
3442 && lhs != 0 && rhs != 0
3443 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3444 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3445 && operand_equal_p (lhs, rhs, 0))
3447 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3448 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3449 which cases we can't do this. */
3450 if (simple_operand_p (lhs))
3451 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3452 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3453 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3454 TREE_OPERAND (exp, 1));
3456 else if ((*lang_hooks.decls.global_bindings_p) () == 0
3457 && ! CONTAINS_PLACEHOLDER_P (lhs))
3459 tree common = save_expr (lhs);
3461 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3462 or_op ? ! in0_p : in0_p,
3464 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3465 or_op ? ! in1_p : in1_p,
3467 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3468 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3469 TREE_TYPE (exp), lhs, rhs);
3476 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3477 bit value. Arrange things so the extra bits will be set to zero if and
3478 only if C is signed-extended to its full width. If MASK is nonzero,
3479 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3482 unextend (tree c, int p, int unsignedp, tree mask)
3484 tree type = TREE_TYPE (c);
3485 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3488 if (p == modesize || unsignedp)
3491 /* We work by getting just the sign bit into the low-order bit, then
3492 into the high-order bit, then sign-extend. We then XOR that value
3494 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3495 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3497 /* We must use a signed type in order to get an arithmetic right shift.
3498 However, we must also avoid introducing accidental overflows, so that
3499 a subsequent call to integer_zerop will work. Hence we must
3500 do the type conversion here. At this point, the constant is either
3501 zero or one, and the conversion to a signed type can never overflow.
3502 We could get an overflow if this conversion is done anywhere else. */
3503 if (TREE_UNSIGNED (type))
3504 temp = convert ((*lang_hooks.types.signed_type) (type), temp);
3506 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3507 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3509 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3510 /* If necessary, convert the type back to match the type of C. */
3511 if (TREE_UNSIGNED (type))
3512 temp = convert (type, temp);
3514 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3517 /* Find ways of folding logical expressions of LHS and RHS:
3518 Try to merge two comparisons to the same innermost item.
3519 Look for range tests like "ch >= '0' && ch <= '9'".
3520 Look for combinations of simple terms on machines with expensive branches
3521 and evaluate the RHS unconditionally.
3523 For example, if we have p->a == 2 && p->b == 4 and we can make an
3524 object large enough to span both A and B, we can do this with a comparison
3525 against the object ANDed with the a mask.
3527 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3528 operations to do this with one comparison.
3530 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3531 function and the one above.
3533 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3534 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3536 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3539 We return the simplified tree or 0 if no optimization is possible. */
3542 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
3544 /* If this is the "or" of two comparisons, we can do something if
3545 the comparisons are NE_EXPR. If this is the "and", we can do something
3546 if the comparisons are EQ_EXPR. I.e.,
3547 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3549 WANTED_CODE is this operation code. For single bit fields, we can
3550 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3551 comparison for one-bit fields. */
3553 enum tree_code wanted_code;
3554 enum tree_code lcode, rcode;
3555 tree ll_arg, lr_arg, rl_arg, rr_arg;
3556 tree ll_inner, lr_inner, rl_inner, rr_inner;
3557 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3558 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3559 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3560 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3561 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3562 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3563 enum machine_mode lnmode, rnmode;
3564 tree ll_mask, lr_mask, rl_mask, rr_mask;
3565 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3566 tree l_const, r_const;
3567 tree lntype, rntype, result;
3568 int first_bit, end_bit;
3571 /* Start by getting the comparison codes. Fail if anything is volatile.
3572 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3573 it were surrounded with a NE_EXPR. */
3575 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3578 lcode = TREE_CODE (lhs);
3579 rcode = TREE_CODE (rhs);
3581 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3582 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3584 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3585 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3587 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3590 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3591 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3593 ll_arg = TREE_OPERAND (lhs, 0);
3594 lr_arg = TREE_OPERAND (lhs, 1);
3595 rl_arg = TREE_OPERAND (rhs, 0);
3596 rr_arg = TREE_OPERAND (rhs, 1);
3598 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
3599 if (simple_operand_p (ll_arg)
3600 && simple_operand_p (lr_arg)
3601 && !FLOAT_TYPE_P (TREE_TYPE (ll_arg)))
3605 if (operand_equal_p (ll_arg, rl_arg, 0)
3606 && operand_equal_p (lr_arg, rr_arg, 0))
3608 int lcompcode, rcompcode;
3610 lcompcode = comparison_to_compcode (lcode);
3611 rcompcode = comparison_to_compcode (rcode);
3612 compcode = (code == TRUTH_AND_EXPR)
3613 ? lcompcode & rcompcode
3614 : lcompcode | rcompcode;
3616 else if (operand_equal_p (ll_arg, rr_arg, 0)
3617 && operand_equal_p (lr_arg, rl_arg, 0))
3619 int lcompcode, rcompcode;
3621 rcode = swap_tree_comparison (rcode);
3622 lcompcode = comparison_to_compcode (lcode);
3623 rcompcode = comparison_to_compcode (rcode);
3624 compcode = (code == TRUTH_AND_EXPR)
3625 ? lcompcode & rcompcode
3626 : lcompcode | rcompcode;
3631 if (compcode == COMPCODE_TRUE)
3632 return convert (truth_type, integer_one_node);
3633 else if (compcode == COMPCODE_FALSE)
3634 return convert (truth_type, integer_zero_node);
3635 else if (compcode != -1)
3636 return build (compcode_to_comparison (compcode),
3637 truth_type, ll_arg, lr_arg);
3640 /* If the RHS can be evaluated unconditionally and its operands are
3641 simple, it wins to evaluate the RHS unconditionally on machines
3642 with expensive branches. In this case, this isn't a comparison
3643 that can be merged. Avoid doing this if the RHS is a floating-point
3644 comparison since those can trap. */
3646 if (BRANCH_COST >= 2
3647 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
3648 && simple_operand_p (rl_arg)
3649 && simple_operand_p (rr_arg))
3651 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
3652 if (code == TRUTH_OR_EXPR
3653 && lcode == NE_EXPR && integer_zerop (lr_arg)
3654 && rcode == NE_EXPR && integer_zerop (rr_arg)
3655 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
3656 return build (NE_EXPR, truth_type,
3657 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
3661 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
3662 if (code == TRUTH_AND_EXPR
3663 && lcode == EQ_EXPR && integer_zerop (lr_arg)
3664 && rcode == EQ_EXPR && integer_zerop (rr_arg)
3665 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
3666 return build (EQ_EXPR, truth_type,
3667 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
3671 return build (code, truth_type, lhs, rhs);
3674 /* See if the comparisons can be merged. Then get all the parameters for
3677 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3678 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3682 ll_inner = decode_field_reference (ll_arg,
3683 &ll_bitsize, &ll_bitpos, &ll_mode,
3684 &ll_unsignedp, &volatilep, &ll_mask,
3686 lr_inner = decode_field_reference (lr_arg,
3687 &lr_bitsize, &lr_bitpos, &lr_mode,
3688 &lr_unsignedp, &volatilep, &lr_mask,
3690 rl_inner = decode_field_reference (rl_arg,
3691 &rl_bitsize, &rl_bitpos, &rl_mode,
3692 &rl_unsignedp, &volatilep, &rl_mask,
3694 rr_inner = decode_field_reference (rr_arg,
3695 &rr_bitsize, &rr_bitpos, &rr_mode,
3696 &rr_unsignedp, &volatilep, &rr_mask,
3699 /* It must be true that the inner operation on the lhs of each
3700 comparison must be the same if we are to be able to do anything.
3701 Then see if we have constants. If not, the same must be true for
3703 if (volatilep || ll_inner == 0 || rl_inner == 0
3704 || ! operand_equal_p (ll_inner, rl_inner, 0))
3707 if (TREE_CODE (lr_arg) == INTEGER_CST
3708 && TREE_CODE (rr_arg) == INTEGER_CST)
3709 l_const = lr_arg, r_const = rr_arg;
3710 else if (lr_inner == 0 || rr_inner == 0
3711 || ! operand_equal_p (lr_inner, rr_inner, 0))
3714 l_const = r_const = 0;
3716 /* If either comparison code is not correct for our logical operation,
3717 fail. However, we can convert a one-bit comparison against zero into
3718 the opposite comparison against that bit being set in the field. */
3720 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
3721 if (lcode != wanted_code)
3723 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
3725 /* Make the left operand unsigned, since we are only interested
3726 in the value of one bit. Otherwise we are doing the wrong
3735 /* This is analogous to the code for l_const above. */
3736 if (rcode != wanted_code)
3738 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
3747 /* After this point all optimizations will generate bit-field
3748 references, which we might not want. */
3749 if (! (*lang_hooks.can_use_bit_fields_p) ())
3752 /* See if we can find a mode that contains both fields being compared on
3753 the left. If we can't, fail. Otherwise, update all constants and masks
3754 to be relative to a field of that size. */
3755 first_bit = MIN (ll_bitpos, rl_bitpos);
3756 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
3757 lnmode = get_best_mode (end_bit - first_bit, first_bit,
3758 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
3760 if (lnmode == VOIDmode)
3763 lnbitsize = GET_MODE_BITSIZE (lnmode);
3764 lnbitpos = first_bit & ~ (lnbitsize - 1);
3765 lntype = (*lang_hooks.types.type_for_size) (lnbitsize, 1);
3766 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
3768 if (BYTES_BIG_ENDIAN)
3770 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
3771 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
3774 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
3775 size_int (xll_bitpos), 0);
3776 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
3777 size_int (xrl_bitpos), 0);
3781 l_const = convert (lntype, l_const);
3782 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
3783 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
3784 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
3785 fold (build1 (BIT_NOT_EXPR,
3789 warning ("comparison is always %d", wanted_code == NE_EXPR);
3791 return convert (truth_type,
3792 wanted_code == NE_EXPR
3793 ? integer_one_node : integer_zero_node);
3798 r_const = convert (lntype, r_const);
3799 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
3800 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
3801 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
3802 fold (build1 (BIT_NOT_EXPR,
3806 warning ("comparison is always %d", wanted_code == NE_EXPR);
3808 return convert (truth_type,
3809 wanted_code == NE_EXPR
3810 ? integer_one_node : integer_zero_node);
3814 /* If the right sides are not constant, do the same for it. Also,
3815 disallow this optimization if a size or signedness mismatch occurs
3816 between the left and right sides. */
3819 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
3820 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
3821 /* Make sure the two fields on the right
3822 correspond to the left without being swapped. */
3823 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
3826 first_bit = MIN (lr_bitpos, rr_bitpos);
3827 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
3828 rnmode = get_best_mode (end_bit - first_bit, first_bit,
3829 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
3831 if (rnmode == VOIDmode)
3834 rnbitsize = GET_MODE_BITSIZE (rnmode);
3835 rnbitpos = first_bit & ~ (rnbitsize - 1);
3836 rntype = (*lang_hooks.types.type_for_size) (rnbitsize, 1);
3837 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
3839 if (BYTES_BIG_ENDIAN)
3841 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
3842 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
3845 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
3846 size_int (xlr_bitpos), 0);
3847 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
3848 size_int (xrr_bitpos), 0);
3850 /* Make a mask that corresponds to both fields being compared.
3851 Do this for both items being compared. If the operands are the
3852 same size and the bits being compared are in the same position
3853 then we can do this by masking both and comparing the masked
3855 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3856 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
3857 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
3859 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
3860 ll_unsignedp || rl_unsignedp);
3861 if (! all_ones_mask_p (ll_mask, lnbitsize))
3862 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
3864 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
3865 lr_unsignedp || rr_unsignedp);
3866 if (! all_ones_mask_p (lr_mask, rnbitsize))
3867 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
3869 return build (wanted_code, truth_type, lhs, rhs);
3872 /* There is still another way we can do something: If both pairs of
3873 fields being compared are adjacent, we may be able to make a wider
3874 field containing them both.
3876 Note that we still must mask the lhs/rhs expressions. Furthermore,
3877 the mask must be shifted to account for the shift done by
3878 make_bit_field_ref. */
3879 if ((ll_bitsize + ll_bitpos == rl_bitpos
3880 && lr_bitsize + lr_bitpos == rr_bitpos)
3881 || (ll_bitpos == rl_bitpos + rl_bitsize
3882 && lr_bitpos == rr_bitpos + rr_bitsize))
3886 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
3887 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
3888 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
3889 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
3891 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
3892 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
3893 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
3894 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
3896 /* Convert to the smaller type before masking out unwanted bits. */
3898 if (lntype != rntype)
3900 if (lnbitsize > rnbitsize)
3902 lhs = convert (rntype, lhs);
3903 ll_mask = convert (rntype, ll_mask);
3906 else if (lnbitsize < rnbitsize)
3908 rhs = convert (lntype, rhs);
3909 lr_mask = convert (lntype, lr_mask);
3914 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
3915 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
3917 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
3918 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
3920 return build (wanted_code, truth_type, lhs, rhs);
3926 /* Handle the case of comparisons with constants. If there is something in
3927 common between the masks, those bits of the constants must be the same.
3928 If not, the condition is always false. Test for this to avoid generating
3929 incorrect code below. */
3930 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
3931 if (! integer_zerop (result)
3932 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
3933 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
3935 if (wanted_code == NE_EXPR)
3937 warning ("`or' of unmatched not-equal tests is always 1");
3938 return convert (truth_type, integer_one_node);
3942 warning ("`and' of mutually exclusive equal-tests is always 0");
3943 return convert (truth_type, integer_zero_node);
3947 /* Construct the expression we will return. First get the component
3948 reference we will make. Unless the mask is all ones the width of
3949 that field, perform the mask operation. Then compare with the
3951 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
3952 ll_unsignedp || rl_unsignedp);
3954 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3955 if (! all_ones_mask_p (ll_mask, lnbitsize))
3956 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
3958 return build (wanted_code, truth_type, result,
3959 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
3962 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
3966 optimize_minmax_comparison (tree t)
3968 tree type = TREE_TYPE (t);
3969 tree arg0 = TREE_OPERAND (t, 0);
3970 enum tree_code op_code;
3971 tree comp_const = TREE_OPERAND (t, 1);
3973 int consts_equal, consts_lt;
3976 STRIP_SIGN_NOPS (arg0);
3978 op_code = TREE_CODE (arg0);
3979 minmax_const = TREE_OPERAND (arg0, 1);
3980 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
3981 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
3982 inner = TREE_OPERAND (arg0, 0);
3984 /* If something does not permit us to optimize, return the original tree. */
3985 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
3986 || TREE_CODE (comp_const) != INTEGER_CST
3987 || TREE_CONSTANT_OVERFLOW (comp_const)
3988 || TREE_CODE (minmax_const) != INTEGER_CST
3989 || TREE_CONSTANT_OVERFLOW (minmax_const))
3992 /* Now handle all the various comparison codes. We only handle EQ_EXPR
3993 and GT_EXPR, doing the rest with recursive calls using logical
3995 switch (TREE_CODE (t))
3997 case NE_EXPR: case LT_EXPR: case LE_EXPR:
3999 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4003 fold (build (TRUTH_ORIF_EXPR, type,
4004 optimize_minmax_comparison
4005 (build (EQ_EXPR, type, arg0, comp_const)),
4006 optimize_minmax_comparison
4007 (build (GT_EXPR, type, arg0, comp_const))));
4010 if (op_code == MAX_EXPR && consts_equal)
4011 /* MAX (X, 0) == 0 -> X <= 0 */
4012 return fold (build (LE_EXPR, type, inner, comp_const));
4014 else if (op_code == MAX_EXPR && consts_lt)
4015 /* MAX (X, 0) == 5 -> X == 5 */
4016 return fold (build (EQ_EXPR, type, inner, comp_const));
4018 else if (op_code == MAX_EXPR)
4019 /* MAX (X, 0) == -1 -> false */
4020 return omit_one_operand (type, integer_zero_node, inner);
4022 else if (consts_equal)
4023 /* MIN (X, 0) == 0 -> X >= 0 */
4024 return fold (build (GE_EXPR, type, inner, comp_const));
4027 /* MIN (X, 0) == 5 -> false */
4028 return omit_one_operand (type, integer_zero_node, inner);
4031 /* MIN (X, 0) == -1 -> X == -1 */
4032 return fold (build (EQ_EXPR, type, inner, comp_const));
4035 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4036 /* MAX (X, 0) > 0 -> X > 0
4037 MAX (X, 0) > 5 -> X > 5 */
4038 return fold (build (GT_EXPR, type, inner, comp_const));
4040 else if (op_code == MAX_EXPR)
4041 /* MAX (X, 0) > -1 -> true */
4042 return omit_one_operand (type, integer_one_node, inner);
4044 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4045 /* MIN (X, 0) > 0 -> false
4046 MIN (X, 0) > 5 -> false */
4047 return omit_one_operand (type, integer_zero_node, inner);
4050 /* MIN (X, 0) > -1 -> X > -1 */
4051 return fold (build (GT_EXPR, type, inner, comp_const));
4058 /* T is an integer expression that is being multiplied, divided, or taken a
4059 modulus (CODE says which and what kind of divide or modulus) by a
4060 constant C. See if we can eliminate that operation by folding it with
4061 other operations already in T. WIDE_TYPE, if non-null, is a type that
4062 should be used for the computation if wider than our type.
4064 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4065 (X * 2) + (Y * 4). We must, however, be assured that either the original
4066 expression would not overflow or that overflow is undefined for the type
4067 in the language in question.
4069 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4070 the machine has a multiply-accumulate insn or that this is part of an
4071 addressing calculation.
4073 If we return a non-null expression, it is an equivalent form of the
4074 original computation, but need not be in the original type. */
4077 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
4079 /* To avoid exponential search depth, refuse to allow recursion past
4080 three levels. Beyond that (1) it's highly unlikely that we'll find
4081 something interesting and (2) we've probably processed it before
4082 when we built the inner expression. */
4091 ret = extract_muldiv_1 (t, c, code, wide_type);
4098 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
4100 tree type = TREE_TYPE (t);
4101 enum tree_code tcode = TREE_CODE (t);
4102 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4103 > GET_MODE_SIZE (TYPE_MODE (type)))
4104 ? wide_type : type);
4106 int same_p = tcode == code;
4107 tree op0 = NULL_TREE, op1 = NULL_TREE;
4109 /* Don't deal with constants of zero here; they confuse the code below. */
4110 if (integer_zerop (c))
4113 if (TREE_CODE_CLASS (tcode) == '1')
4114 op0 = TREE_OPERAND (t, 0);
4116 if (TREE_CODE_CLASS (tcode) == '2')
4117 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4119 /* Note that we need not handle conditional operations here since fold
4120 already handles those cases. So just do arithmetic here. */
4124 /* For a constant, we can always simplify if we are a multiply
4125 or (for divide and modulus) if it is a multiple of our constant. */
4126 if (code == MULT_EXPR
4127 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4128 return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
4131 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4132 /* If op0 is an expression ... */
4133 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
4134 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
4135 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
4136 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
4137 /* ... and is unsigned, and its type is smaller than ctype,
4138 then we cannot pass through as widening. */
4139 && ((TREE_UNSIGNED (TREE_TYPE (op0))
4140 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
4141 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
4142 && (GET_MODE_SIZE (TYPE_MODE (ctype))
4143 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
4144 /* ... or its type is larger than ctype,
4145 then we cannot pass through this truncation. */
4146 || (GET_MODE_SIZE (TYPE_MODE (ctype))
4147 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
4148 /* ... or signedness changes for division or modulus,
4149 then we cannot pass through this conversion. */
4150 || (code != MULT_EXPR
4151 && (TREE_UNSIGNED (ctype)
4152 != TREE_UNSIGNED (TREE_TYPE (op0))))))
4155 /* Pass the constant down and see if we can make a simplification. If
4156 we can, replace this expression with the inner simplification for
4157 possible later conversion to our or some other type. */
4158 if ((t2 = convert (TREE_TYPE (op0), c)) != 0
4159 && TREE_CODE (t2) == INTEGER_CST
4160 && ! TREE_CONSTANT_OVERFLOW (t2)
4161 && (0 != (t1 = extract_muldiv (op0, t2, code,
4163 ? ctype : NULL_TREE))))
4167 case NEGATE_EXPR: case ABS_EXPR:
4168 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4169 return fold (build1 (tcode, ctype, convert (ctype, t1)));
4172 case MIN_EXPR: case MAX_EXPR:
4173 /* If widening the type changes the signedness, then we can't perform
4174 this optimization as that changes the result. */
4175 if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
4178 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4179 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4180 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4182 if (tree_int_cst_sgn (c) < 0)
4183 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4185 return fold (build (tcode, ctype, convert (ctype, t1),
4186 convert (ctype, t2)));
4190 case WITH_RECORD_EXPR:
4191 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4192 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4193 TREE_OPERAND (t, 1));
4196 case LSHIFT_EXPR: case RSHIFT_EXPR:
4197 /* If the second operand is constant, this is a multiplication
4198 or floor division, by a power of two, so we can treat it that
4199 way unless the multiplier or divisor overflows. */
4200 if (TREE_CODE (op1) == INTEGER_CST
4201 /* const_binop may not detect overflow correctly,
4202 so check for it explicitly here. */
4203 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
4204 && TREE_INT_CST_HIGH (op1) == 0
4205 && 0 != (t1 = convert (ctype,
4206 const_binop (LSHIFT_EXPR, size_one_node,
4208 && ! TREE_OVERFLOW (t1))
4209 return extract_muldiv (build (tcode == LSHIFT_EXPR
4210 ? MULT_EXPR : FLOOR_DIV_EXPR,
4211 ctype, convert (ctype, op0), t1),
4212 c, code, wide_type);
4215 case PLUS_EXPR: case MINUS_EXPR:
4216 /* See if we can eliminate the operation on both sides. If we can, we
4217 can return a new PLUS or MINUS. If we can't, the only remaining
4218 cases where we can do anything are if the second operand is a
4220 t1 = extract_muldiv (op0, c, code, wide_type);
4221 t2 = extract_muldiv (op1, c, code, wide_type);
4222 if (t1 != 0 && t2 != 0
4223 && (code == MULT_EXPR
4224 /* If not multiplication, we can only do this if both operands
4225 are divisible by c. */
4226 || (multiple_of_p (ctype, op0, c)
4227 && multiple_of_p (ctype, op1, c))))
4228 return fold (build (tcode, ctype, convert (ctype, t1),
4229 convert (ctype, t2)));
4231 /* If this was a subtraction, negate OP1 and set it to be an addition.
4232 This simplifies the logic below. */
4233 if (tcode == MINUS_EXPR)
4234 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4236 if (TREE_CODE (op1) != INTEGER_CST)
4239 /* If either OP1 or C are negative, this optimization is not safe for
4240 some of the division and remainder types while for others we need
4241 to change the code. */
4242 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4244 if (code == CEIL_DIV_EXPR)
4245 code = FLOOR_DIV_EXPR;
4246 else if (code == FLOOR_DIV_EXPR)
4247 code = CEIL_DIV_EXPR;
4248 else if (code != MULT_EXPR
4249 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
4253 /* If it's a multiply or a division/modulus operation of a multiple
4254 of our constant, do the operation and verify it doesn't overflow. */
4255 if (code == MULT_EXPR
4256 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4258 op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
4259 if (op1 == 0 || TREE_OVERFLOW (op1))
4265 /* If we have an unsigned type is not a sizetype, we cannot widen
4266 the operation since it will change the result if the original
4267 computation overflowed. */
4268 if (TREE_UNSIGNED (ctype)
4269 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
4273 /* If we were able to eliminate our operation from the first side,
4274 apply our operation to the second side and reform the PLUS. */
4275 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4276 return fold (build (tcode, ctype, convert (ctype, t1), op1));
4278 /* The last case is if we are a multiply. In that case, we can
4279 apply the distributive law to commute the multiply and addition
4280 if the multiplication of the constants doesn't overflow. */
4281 if (code == MULT_EXPR)
4282 return fold (build (tcode, ctype, fold (build (code, ctype,
4283 convert (ctype, op0),
4284 convert (ctype, c))),
4290 /* We have a special case here if we are doing something like
4291 (C * 8) % 4 since we know that's zero. */
4292 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4293 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4294 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4295 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4296 return omit_one_operand (type, integer_zero_node, op0);
4298 /* ... fall through ... */
4300 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4301 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4302 /* If we can extract our operation from the LHS, do so and return a
4303 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4304 do something only if the second operand is a constant. */
4306 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4307 return fold (build (tcode, ctype, convert (ctype, t1),
4308 convert (ctype, op1)));
4309 else if (tcode == MULT_EXPR && code == MULT_EXPR
4310 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4311 return fold (build (tcode, ctype, convert (ctype, op0),
4312 convert (ctype, t1)));
4313 else if (TREE_CODE (op1) != INTEGER_CST)
4316 /* If these are the same operation types, we can associate them
4317 assuming no overflow. */
4319 && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
4320 convert (ctype, c), 0))
4321 && ! TREE_OVERFLOW (t1))
4322 return fold (build (tcode, ctype, convert (ctype, op0), t1));
4324 /* If these operations "cancel" each other, we have the main
4325 optimizations of this pass, which occur when either constant is a
4326 multiple of the other, in which case we replace this with either an
4327 operation or CODE or TCODE.
4329 If we have an unsigned type that is not a sizetype, we cannot do
4330 this since it will change the result if the original computation
4332 if ((! TREE_UNSIGNED (ctype)
4333 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
4335 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4336 || (tcode == MULT_EXPR
4337 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4338 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
4340 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4341 return fold (build (tcode, ctype, convert (ctype, op0),
4343 const_binop (TRUNC_DIV_EXPR,
4345 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4346 return fold (build (code, ctype, convert (ctype, op0),
4348 const_binop (TRUNC_DIV_EXPR,
4360 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4361 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4362 that we may sometimes modify the tree. */
4365 strip_compound_expr (tree t, tree s)
4367 enum tree_code code = TREE_CODE (t);
4369 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4370 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4371 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4372 return TREE_OPERAND (t, 1);
4374 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4375 don't bother handling any other types. */
4376 else if (code == COND_EXPR)
4378 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4379 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4380 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4382 else if (TREE_CODE_CLASS (code) == '1')
4383 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4384 else if (TREE_CODE_CLASS (code) == '<'
4385 || TREE_CODE_CLASS (code) == '2')
4387 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4388 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4394 /* Return a node which has the indicated constant VALUE (either 0 or
4395 1), and is of the indicated TYPE. */
4398 constant_boolean_node (int value, tree type)
4400 if (type == integer_type_node)
4401 return value ? integer_one_node : integer_zero_node;
4402 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4403 return (*lang_hooks.truthvalue_conversion) (value ? integer_one_node :
4407 tree t = build_int_2 (value, 0);
4409 TREE_TYPE (t) = type;
4414 /* Utility function for the following routine, to see how complex a nesting of
4415 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4416 we don't care (to avoid spending too much time on complex expressions.). */
4419 count_cond (tree expr, int lim)
4423 if (TREE_CODE (expr) != COND_EXPR)
4428 ctrue = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4429 cfalse = count_cond (TREE_OPERAND (expr, 2), lim - 1 - ctrue);
4430 return MIN (lim, 1 + ctrue + cfalse);
4433 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
4434 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4435 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4436 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
4437 COND is the first argument to CODE; otherwise (as in the example
4438 given here), it is the second argument. TYPE is the type of the
4439 original expression. */
4442 fold_binary_op_with_conditional_arg (enum tree_code code, tree type,
4443 tree cond, tree arg, int cond_first_p)
4445 tree test, true_value, false_value;
4446 tree lhs = NULL_TREE;
4447 tree rhs = NULL_TREE;
4448 /* In the end, we'll produce a COND_EXPR. Both arms of the
4449 conditional expression will be binary operations. The left-hand
4450 side of the expression to be executed if the condition is true
4451 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4452 of the expression to be executed if the condition is true will be
4453 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4454 but apply to the expression to be executed if the conditional is
4460 /* These are the codes to use for the left-hand side and right-hand
4461 side of the COND_EXPR. Normally, they are the same as CODE. */
4462 enum tree_code lhs_code = code;
4463 enum tree_code rhs_code = code;
4464 /* And these are the types of the expressions. */
4465 tree lhs_type = type;
4466 tree rhs_type = type;
4471 true_rhs = false_rhs = &arg;
4472 true_lhs = &true_value;
4473 false_lhs = &false_value;
4477 true_lhs = false_lhs = &arg;
4478 true_rhs = &true_value;
4479 false_rhs = &false_value;
4482 if (TREE_CODE (cond) == COND_EXPR)
4484 test = TREE_OPERAND (cond, 0);
4485 true_value = TREE_OPERAND (cond, 1);
4486 false_value = TREE_OPERAND (cond, 2);
4487 /* If this operand throws an expression, then it does not make
4488 sense to try to perform a logical or arithmetic operation
4489 involving it. Instead of building `a + throw 3' for example,
4490 we simply build `a, throw 3'. */
4491 if (VOID_TYPE_P (TREE_TYPE (true_value)))
4495 lhs_code = COMPOUND_EXPR;
4496 lhs_type = void_type_node;
4501 if (VOID_TYPE_P (TREE_TYPE (false_value)))
4505 rhs_code = COMPOUND_EXPR;
4506 rhs_type = void_type_node;
4514 tree testtype = TREE_TYPE (cond);
4516 true_value = convert (testtype, integer_one_node);
4517 false_value = convert (testtype, integer_zero_node);
4520 /* If ARG is complex we want to make sure we only evaluate it once. Though
4521 this is only required if it is volatile, it might be more efficient even
4522 if it is not. However, if we succeed in folding one part to a constant,
4523 we do not need to make this SAVE_EXPR. Since we do this optimization
4524 primarily to see if we do end up with constant and this SAVE_EXPR
4525 interferes with later optimizations, suppressing it when we can is
4528 If we are not in a function, we can't make a SAVE_EXPR, so don't try to
4529 do so. Don't try to see if the result is a constant if an arm is a
4530 COND_EXPR since we get exponential behavior in that case. */
4532 if (saved_expr_p (arg))
4534 else if (lhs == 0 && rhs == 0
4535 && !TREE_CONSTANT (arg)
4536 && (*lang_hooks.decls.global_bindings_p) () == 0
4537 && ((TREE_CODE (arg) != VAR_DECL && TREE_CODE (arg) != PARM_DECL)
4538 || TREE_SIDE_EFFECTS (arg)))
4540 if (TREE_CODE (true_value) != COND_EXPR)
4541 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4543 if (TREE_CODE (false_value) != COND_EXPR)
4544 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4546 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4547 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4549 arg = save_expr (arg);
4556 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4558 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4560 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4563 return build (COMPOUND_EXPR, type,
4564 convert (void_type_node, arg),
4565 strip_compound_expr (test, arg));
4567 return convert (type, test);
4571 /* Subroutine of fold() that checks for the addition of +/- 0.0.
4573 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
4574 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
4575 ADDEND is the same as X.
4577 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
4578 and finite. The problematic cases are when X is zero, and its mode
4579 has signed zeros. In the case of rounding towards -infinity,
4580 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
4581 modes, X + 0 is not the same as X because -0 + 0 is 0. */
4584 fold_real_zero_addition_p (tree type, tree addend, int negate)
4586 if (!real_zerop (addend))
4589 /* Don't allow the fold with -fsignaling-nans. */
4590 if (HONOR_SNANS (TYPE_MODE (type)))
4593 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
4594 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
4597 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
4598 if (TREE_CODE (addend) == REAL_CST
4599 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
4602 /* The mode has signed zeros, and we have to honor their sign.
4603 In this situation, there is only one case we can return true for.
4604 X - 0 is the same as X unless rounding towards -infinity is
4606 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
4609 /* Subroutine of fold() that checks comparisons of built-in math
4610 functions against real constants.
4612 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
4613 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
4614 is the type of the result and ARG0 and ARG1 are the operands of the
4615 comparison. ARG1 must be a TREE_REAL_CST.
4617 The function returns the constant folded tree if a simplification
4618 can be made, and NULL_TREE otherwise. */
4621 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
4622 tree type, tree arg0, tree arg1)
4626 if (fcode == BUILT_IN_SQRT
4627 || fcode == BUILT_IN_SQRTF
4628 || fcode == BUILT_IN_SQRTL)
4630 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
4631 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
4633 c = TREE_REAL_CST (arg1);
4634 if (REAL_VALUE_NEGATIVE (c))
4636 /* sqrt(x) < y is always false, if y is negative. */
4637 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
4638 return omit_one_operand (type,
4639 convert (type, integer_zero_node),
4642 /* sqrt(x) > y is always true, if y is negative and we
4643 don't care about NaNs, i.e. negative values of x. */
4644 if (code == NE_EXPR || !HONOR_NANS (mode))
4645 return omit_one_operand (type,
4646 convert (type, integer_one_node),
4649 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
4650 return fold (build (GE_EXPR, type, arg,
4651 build_real (TREE_TYPE (arg), dconst0)));
4653 else if (code == GT_EXPR || code == GE_EXPR)
4657 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
4658 real_convert (&c2, mode, &c2);
4660 if (REAL_VALUE_ISINF (c2))
4662 /* sqrt(x) > y is x == +Inf, when y is very large. */
4663 if (HONOR_INFINITIES (mode))
4664 return fold (build (EQ_EXPR, type, arg,
4665 build_real (TREE_TYPE (arg), c2)));
4667 /* sqrt(x) > y is always false, when y is very large
4668 and we don't care about infinities. */
4669 return omit_one_operand (type,
4670 convert (type, integer_zero_node),
4674 /* sqrt(x) > c is the same as x > c*c. */
4675 return fold (build (code, type, arg,
4676 build_real (TREE_TYPE (arg), c2)));
4678 else if (code == LT_EXPR || code == LE_EXPR)
4682 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
4683 real_convert (&c2, mode, &c2);
4685 if (REAL_VALUE_ISINF (c2))
4687 /* sqrt(x) < y is always true, when y is a very large
4688 value and we don't care about NaNs or Infinities. */
4689 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
4690 return omit_one_operand (type,
4691 convert (type, integer_one_node),
4694 /* sqrt(x) < y is x != +Inf when y is very large and we
4695 don't care about NaNs. */
4696 if (! HONOR_NANS (mode))
4697 return fold (build (NE_EXPR, type, arg,
4698 build_real (TREE_TYPE (arg), c2)));
4700 /* sqrt(x) < y is x >= 0 when y is very large and we
4701 don't care about Infinities. */
4702 if (! HONOR_INFINITIES (mode))
4703 return fold (build (GE_EXPR, type, arg,
4704 build_real (TREE_TYPE (arg), dconst0)));
4706 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
4707 if ((*lang_hooks.decls.global_bindings_p) () != 0
4708 || CONTAINS_PLACEHOLDER_P (arg))
4711 arg = save_expr (arg);
4712 return fold (build (TRUTH_ANDIF_EXPR, type,
4713 fold (build (GE_EXPR, type, arg,
4714 build_real (TREE_TYPE (arg),
4716 fold (build (NE_EXPR, type, arg,
4717 build_real (TREE_TYPE (arg),
4721 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
4722 if (! HONOR_NANS (mode))
4723 return fold (build (code, type, arg,
4724 build_real (TREE_TYPE (arg), c2)));
4726 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
4727 if ((*lang_hooks.decls.global_bindings_p) () == 0
4728 && ! CONTAINS_PLACEHOLDER_P (arg))
4730 arg = save_expr (arg);
4731 return fold (build (TRUTH_ANDIF_EXPR, type,
4732 fold (build (GE_EXPR, type, arg,
4733 build_real (TREE_TYPE (arg),
4735 fold (build (code, type, arg,
4736 build_real (TREE_TYPE (arg),
4745 /* Subroutine of fold() that optimizes comparisons against Infinities,
4746 either +Inf or -Inf.
4748 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
4749 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
4750 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
4752 The function returns the constant folded tree if a simplification
4753 can be made, and NULL_TREE otherwise. */
4756 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
4758 enum machine_mode mode;
4759 REAL_VALUE_TYPE max;
4763 mode = TYPE_MODE (TREE_TYPE (arg0));
4765 /* For negative infinity swap the sense of the comparison. */
4766 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
4768 code = swap_tree_comparison (code);
4773 /* x > +Inf is always false, if with ignore sNANs. */
4774 if (HONOR_SNANS (mode))
4776 return omit_one_operand (type,
4777 convert (type, integer_zero_node),
4781 /* x <= +Inf is always true, if we don't case about NaNs. */
4782 if (! HONOR_NANS (mode))
4783 return omit_one_operand (type,
4784 convert (type, integer_one_node),
4787 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
4788 if ((*lang_hooks.decls.global_bindings_p) () == 0
4789 && ! CONTAINS_PLACEHOLDER_P (arg0))
4791 arg0 = save_expr (arg0);
4792 return fold (build (EQ_EXPR, type, arg0, arg0));
4798 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
4799 real_maxval (&max, neg, mode);
4800 return fold (build (neg ? LT_EXPR : GT_EXPR, type,
4801 arg0, build_real (TREE_TYPE (arg0), max)));
4804 /* x < +Inf is always equal to x <= DBL_MAX. */
4805 real_maxval (&max, neg, mode);
4806 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
4807 arg0, build_real (TREE_TYPE (arg0), max)));
4810 /* x != +Inf is always equal to !(x > DBL_MAX). */
4811 real_maxval (&max, neg, mode);
4812 if (! HONOR_NANS (mode))
4813 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
4814 arg0, build_real (TREE_TYPE (arg0), max)));
4815 temp = fold (build (neg ? LT_EXPR : GT_EXPR, type,
4816 arg0, build_real (TREE_TYPE (arg0), max)));
4817 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
4826 /* If CODE with arguments ARG0 and ARG1 represents a single bit
4827 equality/inequality test, then return a simplified form of
4828 the test using shifts and logical operations. Otherwise return
4829 NULL. TYPE is the desired result type. */
4832 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
4835 /* If this is a TRUTH_NOT_EXPR, it may have a single bit test inside
4837 if (code == TRUTH_NOT_EXPR)
4839 code = TREE_CODE (arg0);
4840 if (code != NE_EXPR && code != EQ_EXPR)
4843 /* Extract the arguments of the EQ/NE. */
4844 arg1 = TREE_OPERAND (arg0, 1);
4845 arg0 = TREE_OPERAND (arg0, 0);
4847 /* This requires us to invert the code. */
4848 code = (code == EQ_EXPR ? NE_EXPR : EQ_EXPR);
4851 /* If this is testing a single bit, we can optimize the test. */
4852 if ((code == NE_EXPR || code == EQ_EXPR)
4853 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
4854 && integer_pow2p (TREE_OPERAND (arg0, 1)))
4856 tree inner = TREE_OPERAND (arg0, 0);
4857 tree type = TREE_TYPE (arg0);
4858 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
4859 enum machine_mode operand_mode = TYPE_MODE (type);
4861 tree signed_type, unsigned_type;
4864 /* If we have (A & C) != 0 where C is the sign bit of A, convert
4865 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
4866 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
4867 if (arg00 != NULL_TREE)
4869 tree stype = (*lang_hooks.types.signed_type) (TREE_TYPE (arg00));
4870 return fold (build (code == EQ_EXPR ? GE_EXPR : LT_EXPR, result_type,
4871 convert (stype, arg00),
4872 convert (stype, integer_zero_node)));
4875 /* At this point, we know that arg0 is not testing the sign bit. */
4876 if (TYPE_PRECISION (type) - 1 == bitnum)
4879 /* Otherwise we have (A & C) != 0 where C is a single bit,
4880 convert that into ((A >> C2) & 1). Where C2 = log2(C).
4881 Similarly for (A & C) == 0. */
4883 /* If INNER is a right shift of a constant and it plus BITNUM does
4884 not overflow, adjust BITNUM and INNER. */
4885 if (TREE_CODE (inner) == RSHIFT_EXPR
4886 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
4887 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
4888 && bitnum < TYPE_PRECISION (type)
4889 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
4890 bitnum - TYPE_PRECISION (type)))
4892 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
4893 inner = TREE_OPERAND (inner, 0);
4896 /* If we are going to be able to omit the AND below, we must do our
4897 operations as unsigned. If we must use the AND, we have a choice.
4898 Normally unsigned is faster, but for some machines signed is. */
4899 #ifdef LOAD_EXTEND_OP
4900 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND ? 0 : 1);
4905 signed_type = (*lang_hooks.types.type_for_mode) (operand_mode, 0);
4906 unsigned_type = (*lang_hooks.types.type_for_mode) (operand_mode, 1);
4909 inner = build (RSHIFT_EXPR, ops_unsigned ? unsigned_type : signed_type,
4910 inner, size_int (bitnum));
4912 if (code == EQ_EXPR)
4913 inner = build (BIT_XOR_EXPR, ops_unsigned ? unsigned_type : signed_type,
4914 inner, integer_one_node);
4916 /* Put the AND last so it can combine with more things. */
4917 inner = build (BIT_AND_EXPR, ops_unsigned ? unsigned_type : signed_type,
4918 inner, integer_one_node);
4920 /* Make sure to return the proper type. */
4921 if (TREE_TYPE (inner) != result_type)
4922 inner = convert (result_type, inner);
4929 /* Perform constant folding and related simplification of EXPR.
4930 The related simplifications include x*1 => x, x*0 => 0, etc.,
4931 and application of the associative law.
4932 NOP_EXPR conversions may be removed freely (as long as we
4933 are careful not to change the C type of the overall expression)
4934 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4935 but we can constant-fold them if they have constant operands. */
4937 #ifdef ENABLE_FOLD_CHECKING
4938 # define fold(x) fold_1 (x)
4939 static tree fold_1 (tree);
4945 tree t = expr, orig_t;
4946 tree t1 = NULL_TREE;
4948 tree type = TREE_TYPE (expr);
4949 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4950 enum tree_code code = TREE_CODE (t);
4951 int kind = TREE_CODE_CLASS (code);
4953 /* WINS will be nonzero when the switch is done
4954 if all operands are constant. */
4957 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4958 Likewise for a SAVE_EXPR that's already been evaluated. */
4959 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0))
4962 /* Return right away if a constant. */
4966 #ifdef MAX_INTEGER_COMPUTATION_MODE
4967 check_max_integer_computation_mode (expr);
4971 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4975 /* Special case for conversion ops that can have fixed point args. */
4976 arg0 = TREE_OPERAND (t, 0);
4978 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4980 STRIP_SIGN_NOPS (arg0);
4982 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4983 subop = TREE_REALPART (arg0);
4987 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4988 && TREE_CODE (subop) != REAL_CST
4990 /* Note that TREE_CONSTANT isn't enough:
4991 static var addresses are constant but we can't
4992 do arithmetic on them. */
4995 else if (IS_EXPR_CODE_CLASS (kind) || kind == 'r')
4997 int len = first_rtl_op (code);
4999 for (i = 0; i < len; i++)
5001 tree op = TREE_OPERAND (t, i);
5005 continue; /* Valid for CALL_EXPR, at least. */
5007 if (kind == '<' || code == RSHIFT_EXPR)
5009 /* Signedness matters here. Perhaps we can refine this
5011 STRIP_SIGN_NOPS (op);
5014 /* Strip any conversions that don't change the mode. */
5017 if (TREE_CODE (op) == COMPLEX_CST)
5018 subop = TREE_REALPART (op);
5022 if (TREE_CODE (subop) != INTEGER_CST
5023 && TREE_CODE (subop) != REAL_CST)
5024 /* Note that TREE_CONSTANT isn't enough:
5025 static var addresses are constant but we can't
5026 do arithmetic on them. */
5036 /* If this is a commutative operation, and ARG0 is a constant, move it
5037 to ARG1 to reduce the number of tests below. */
5038 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
5039 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
5040 || code == BIT_AND_EXPR)
5041 && ((TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) != INTEGER_CST)
5042 || (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) != REAL_CST)))
5044 tem = arg0; arg0 = arg1; arg1 = tem;
5048 TREE_OPERAND (t, 0) = arg0;
5049 TREE_OPERAND (t, 1) = arg1;
5052 /* Now WINS is set as described above,
5053 ARG0 is the first operand of EXPR,
5054 and ARG1 is the second operand (if it has more than one operand).
5056 First check for cases where an arithmetic operation is applied to a
5057 compound, conditional, or comparison operation. Push the arithmetic
5058 operation inside the compound or conditional to see if any folding
5059 can then be done. Convert comparison to conditional for this purpose.
5060 The also optimizes non-constant cases that used to be done in
5063 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
5064 one of the operands is a comparison and the other is a comparison, a
5065 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
5066 code below would make the expression more complex. Change it to a
5067 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
5068 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
5070 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
5071 || code == EQ_EXPR || code == NE_EXPR)
5072 && ((truth_value_p (TREE_CODE (arg0))
5073 && (truth_value_p (TREE_CODE (arg1))
5074 || (TREE_CODE (arg1) == BIT_AND_EXPR
5075 && integer_onep (TREE_OPERAND (arg1, 1)))))
5076 || (truth_value_p (TREE_CODE (arg1))
5077 && (truth_value_p (TREE_CODE (arg0))
5078 || (TREE_CODE (arg0) == BIT_AND_EXPR
5079 && integer_onep (TREE_OPERAND (arg0, 1)))))))
5081 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
5082 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
5086 if (code == EQ_EXPR)
5087 t = invert_truthvalue (t);
5092 if (TREE_CODE_CLASS (code) == '1')
5094 if (TREE_CODE (arg0) == COMPOUND_EXPR)
5095 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5096 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
5097 else if (TREE_CODE (arg0) == COND_EXPR)
5099 tree arg01 = TREE_OPERAND (arg0, 1);
5100 tree arg02 = TREE_OPERAND (arg0, 2);
5101 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
5102 arg01 = fold (build1 (code, type, arg01));
5103 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
5104 arg02 = fold (build1 (code, type, arg02));
5105 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
5108 /* If this was a conversion, and all we did was to move into
5109 inside the COND_EXPR, bring it back out. But leave it if
5110 it is a conversion from integer to integer and the
5111 result precision is no wider than a word since such a
5112 conversion is cheap and may be optimized away by combine,
5113 while it couldn't if it were outside the COND_EXPR. Then return
5114 so we don't get into an infinite recursion loop taking the
5115 conversion out and then back in. */
5117 if ((code == NOP_EXPR || code == CONVERT_EXPR
5118 || code == NON_LVALUE_EXPR)
5119 && TREE_CODE (t) == COND_EXPR
5120 && TREE_CODE (TREE_OPERAND (t, 1)) == code
5121 && TREE_CODE (TREE_OPERAND (t, 2)) == code
5122 && ! VOID_TYPE_P (TREE_OPERAND (t, 1))
5123 && ! VOID_TYPE_P (TREE_OPERAND (t, 2))
5124 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
5125 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
5126 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
5128 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
5129 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
5130 t = build1 (code, type,
5132 TREE_TYPE (TREE_OPERAND
5133 (TREE_OPERAND (t, 1), 0)),
5134 TREE_OPERAND (t, 0),
5135 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
5136 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
5139 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
5140 return fold (build (COND_EXPR, type, arg0,
5141 fold (build1 (code, type, integer_one_node)),
5142 fold (build1 (code, type, integer_zero_node))));
5144 else if (TREE_CODE_CLASS (code) == '<'
5145 && TREE_CODE (arg0) == COMPOUND_EXPR)
5146 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5147 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5148 else if (TREE_CODE_CLASS (code) == '<'
5149 && TREE_CODE (arg1) == COMPOUND_EXPR)
5150 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5151 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
5152 else if (TREE_CODE_CLASS (code) == '2'
5153 || TREE_CODE_CLASS (code) == '<')
5155 if (TREE_CODE (arg1) == COMPOUND_EXPR
5156 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1, 0))
5157 && ! TREE_SIDE_EFFECTS (arg0))
5158 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5159 fold (build (code, type,
5160 arg0, TREE_OPERAND (arg1, 1))));
5161 else if ((TREE_CODE (arg1) == COND_EXPR
5162 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
5163 && TREE_CODE_CLASS (code) != '<'))
5164 && (TREE_CODE (arg0) != COND_EXPR
5165 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5166 && (! TREE_SIDE_EFFECTS (arg0)
5167 || ((*lang_hooks.decls.global_bindings_p) () == 0
5168 && ! CONTAINS_PLACEHOLDER_P (arg0))))
5170 fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
5171 /*cond_first_p=*/0);
5172 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
5173 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5174 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5175 else if ((TREE_CODE (arg0) == COND_EXPR
5176 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
5177 && TREE_CODE_CLASS (code) != '<'))
5178 && (TREE_CODE (arg1) != COND_EXPR
5179 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5180 && (! TREE_SIDE_EFFECTS (arg1)
5181 || ((*lang_hooks.decls.global_bindings_p) () == 0
5182 && ! CONTAINS_PLACEHOLDER_P (arg1))))
5184 fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
5185 /*cond_first_p=*/1);
5199 return fold (DECL_INITIAL (t));
5204 case FIX_TRUNC_EXPR:
5205 /* Other kinds of FIX are not handled properly by fold_convert. */
5207 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
5208 return TREE_OPERAND (t, 0);
5210 /* Handle cases of two conversions in a row. */
5211 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
5212 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
5214 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5215 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
5216 tree final_type = TREE_TYPE (t);
5217 int inside_int = INTEGRAL_TYPE_P (inside_type);
5218 int inside_ptr = POINTER_TYPE_P (inside_type);
5219 int inside_float = FLOAT_TYPE_P (inside_type);
5220 unsigned int inside_prec = TYPE_PRECISION (inside_type);
5221 int inside_unsignedp = TREE_UNSIGNED (inside_type);
5222 int inter_int = INTEGRAL_TYPE_P (inter_type);
5223 int inter_ptr = POINTER_TYPE_P (inter_type);
5224 int inter_float = FLOAT_TYPE_P (inter_type);
5225 unsigned int inter_prec = TYPE_PRECISION (inter_type);
5226 int inter_unsignedp = TREE_UNSIGNED (inter_type);
5227 int final_int = INTEGRAL_TYPE_P (final_type);
5228 int final_ptr = POINTER_TYPE_P (final_type);
5229 int final_float = FLOAT_TYPE_P (final_type);
5230 unsigned int final_prec = TYPE_PRECISION (final_type);
5231 int final_unsignedp = TREE_UNSIGNED (final_type);
5233 /* In addition to the cases of two conversions in a row
5234 handled below, if we are converting something to its own
5235 type via an object of identical or wider precision, neither
5236 conversion is needed. */
5237 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (final_type)
5238 && ((inter_int && final_int) || (inter_float && final_float))
5239 && inter_prec >= final_prec)
5240 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5242 /* Likewise, if the intermediate and final types are either both
5243 float or both integer, we don't need the middle conversion if
5244 it is wider than the final type and doesn't change the signedness
5245 (for integers). Avoid this if the final type is a pointer
5246 since then we sometimes need the inner conversion. Likewise if
5247 the outer has a precision not equal to the size of its mode. */
5248 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
5249 || (inter_float && inside_float))
5250 && inter_prec >= inside_prec
5251 && (inter_float || inter_unsignedp == inside_unsignedp)
5252 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5253 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5255 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5257 /* If we have a sign-extension of a zero-extended value, we can
5258 replace that by a single zero-extension. */
5259 if (inside_int && inter_int && final_int
5260 && inside_prec < inter_prec && inter_prec < final_prec
5261 && inside_unsignedp && !inter_unsignedp)
5262 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5264 /* Two conversions in a row are not needed unless:
5265 - some conversion is floating-point (overstrict for now), or
5266 - the intermediate type is narrower than both initial and
5268 - the intermediate type and innermost type differ in signedness,
5269 and the outermost type is wider than the intermediate, or
5270 - the initial type is a pointer type and the precisions of the
5271 intermediate and final types differ, or
5272 - the final type is a pointer type and the precisions of the
5273 initial and intermediate types differ. */
5274 if (! inside_float && ! inter_float && ! final_float
5275 && (inter_prec > inside_prec || inter_prec > final_prec)
5276 && ! (inside_int && inter_int
5277 && inter_unsignedp != inside_unsignedp
5278 && inter_prec < final_prec)
5279 && ((inter_unsignedp && inter_prec > inside_prec)
5280 == (final_unsignedp && final_prec > inter_prec))
5281 && ! (inside_ptr && inter_prec != final_prec)
5282 && ! (final_ptr && inside_prec != inter_prec)
5283 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5284 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5286 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5289 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5290 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5291 /* Detect assigning a bitfield. */
5292 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5293 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5295 /* Don't leave an assignment inside a conversion
5296 unless assigning a bitfield. */
5297 tree prev = TREE_OPERAND (t, 0);
5300 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5301 /* First do the assignment, then return converted constant. */
5302 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5307 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
5308 constants (if x has signed type, the sign bit cannot be set
5309 in c). This folds extension into the BIT_AND_EXPR. */
5310 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
5311 && TREE_CODE (TREE_TYPE (t)) != BOOLEAN_TYPE
5312 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
5313 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
5315 tree and = TREE_OPERAND (t, 0);
5316 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
5319 if (TREE_UNSIGNED (TREE_TYPE (and))
5320 || (TYPE_PRECISION (TREE_TYPE (t))
5321 <= TYPE_PRECISION (TREE_TYPE (and))))
5323 else if (TYPE_PRECISION (TREE_TYPE (and1))
5324 <= HOST_BITS_PER_WIDE_INT
5325 && host_integerp (and1, 1))
5327 unsigned HOST_WIDE_INT cst;
5329 cst = tree_low_cst (and1, 1);
5330 cst &= (HOST_WIDE_INT) -1
5331 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
5332 change = (cst == 0);
5333 #ifdef LOAD_EXTEND_OP
5335 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
5338 tree uns = (*lang_hooks.types.unsigned_type) (TREE_TYPE (and0));
5339 and0 = convert (uns, and0);
5340 and1 = convert (uns, and1);
5345 return fold (build (BIT_AND_EXPR, TREE_TYPE (t),
5346 convert (TREE_TYPE (t), and0),
5347 convert (TREE_TYPE (t), and1)));
5352 if (TREE_CONSTANT (t) != TREE_CONSTANT (arg0))
5356 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
5360 return fold_convert (t, arg0);
5362 case VIEW_CONVERT_EXPR:
5363 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
5364 return build1 (VIEW_CONVERT_EXPR, type,
5365 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5369 if (TREE_CODE (arg0) == CONSTRUCTOR
5370 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
5372 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5379 if (TREE_CONSTANT (t) != wins)
5383 TREE_CONSTANT (t) = wins;
5390 if (TREE_CODE (arg0) == INTEGER_CST)
5392 unsigned HOST_WIDE_INT low;
5394 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5395 TREE_INT_CST_HIGH (arg0),
5397 t = build_int_2 (low, high);
5398 TREE_TYPE (t) = type;
5400 = (TREE_OVERFLOW (arg0)
5401 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
5402 TREE_CONSTANT_OVERFLOW (t)
5403 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5405 else if (TREE_CODE (arg0) == REAL_CST)
5406 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5408 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5409 return TREE_OPERAND (arg0, 0);
5410 /* Convert -((double)float) into (double)(-float). */
5411 else if (TREE_CODE (arg0) == NOP_EXPR
5412 && TREE_CODE (type) == REAL_TYPE)
5414 tree targ0 = strip_float_extensions (arg0);
5416 return convert (type, build1 (NEGATE_EXPR, TREE_TYPE (targ0), targ0));
5420 /* Convert - (a - b) to (b - a) for non-floating-point. */
5421 else if (TREE_CODE (arg0) == MINUS_EXPR
5422 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
5423 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
5424 TREE_OPERAND (arg0, 0));
5426 /* Convert -f(x) into f(-x) where f is sin, tan or atan. */
5427 switch (builtin_mathfn_code (arg0))
5436 case BUILT_IN_ATANF:
5437 case BUILT_IN_ATANL:
5438 if (negate_expr_p (TREE_VALUE (TREE_OPERAND (arg0, 1))))
5440 tree fndecl, arg, arglist;
5442 fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5443 arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5444 arg = fold (build1 (NEGATE_EXPR, type, arg));
5445 arglist = build_tree_list (NULL_TREE, arg);
5446 return build_function_call_expr (fndecl, arglist);
5458 if (TREE_CODE (arg0) == INTEGER_CST)
5460 /* If the value is unsigned, then the absolute value is
5461 the same as the ordinary value. */
5462 if (TREE_UNSIGNED (type))
5464 /* Similarly, if the value is non-negative. */
5465 else if (INT_CST_LT (integer_minus_one_node, arg0))
5467 /* If the value is negative, then the absolute value is
5471 unsigned HOST_WIDE_INT low;
5473 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5474 TREE_INT_CST_HIGH (arg0),
5476 t = build_int_2 (low, high);
5477 TREE_TYPE (t) = type;
5479 = (TREE_OVERFLOW (arg0)
5480 | force_fit_type (t, overflow));
5481 TREE_CONSTANT_OVERFLOW (t)
5482 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5485 else if (TREE_CODE (arg0) == REAL_CST)
5487 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5488 t = build_real (type,
5489 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5492 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5493 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
5494 /* Convert fabs((double)float) into (double)fabsf(float). */
5495 else if (TREE_CODE (arg0) == NOP_EXPR
5496 && TREE_CODE (type) == REAL_TYPE)
5498 tree targ0 = strip_float_extensions (arg0);
5500 return convert (type, fold (build1 (ABS_EXPR, TREE_TYPE (targ0),
5503 else if (tree_expr_nonnegative_p (arg0))
5508 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5509 return convert (type, arg0);
5510 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5511 return build (COMPLEX_EXPR, type,
5512 TREE_OPERAND (arg0, 0),
5513 negate_expr (TREE_OPERAND (arg0, 1)));
5514 else if (TREE_CODE (arg0) == COMPLEX_CST)
5515 return build_complex (type, TREE_REALPART (arg0),
5516 negate_expr (TREE_IMAGPART (arg0)));
5517 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5518 return fold (build (TREE_CODE (arg0), type,
5519 fold (build1 (CONJ_EXPR, type,
5520 TREE_OPERAND (arg0, 0))),
5521 fold (build1 (CONJ_EXPR,
5522 type, TREE_OPERAND (arg0, 1)))));
5523 else if (TREE_CODE (arg0) == CONJ_EXPR)
5524 return TREE_OPERAND (arg0, 0);
5530 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5531 ~ TREE_INT_CST_HIGH (arg0));
5532 TREE_TYPE (t) = type;
5533 force_fit_type (t, 0);
5534 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5535 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5537 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5538 return TREE_OPERAND (arg0, 0);
5542 /* A + (-B) -> A - B */
5543 if (TREE_CODE (arg1) == NEGATE_EXPR)
5544 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5545 /* (-A) + B -> B - A */
5546 if (TREE_CODE (arg0) == NEGATE_EXPR)
5547 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5548 else if (! FLOAT_TYPE_P (type))
5550 if (integer_zerop (arg1))
5551 return non_lvalue (convert (type, arg0));
5553 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5554 with a constant, and the two constants have no bits in common,
5555 we should treat this as a BIT_IOR_EXPR since this may produce more
5557 if (TREE_CODE (arg0) == BIT_AND_EXPR
5558 && TREE_CODE (arg1) == BIT_AND_EXPR
5559 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5560 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5561 && integer_zerop (const_binop (BIT_AND_EXPR,
5562 TREE_OPERAND (arg0, 1),
5563 TREE_OPERAND (arg1, 1), 0)))
5565 code = BIT_IOR_EXPR;
5569 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5570 (plus (plus (mult) (mult)) (foo)) so that we can
5571 take advantage of the factoring cases below. */
5572 if ((TREE_CODE (arg0) == PLUS_EXPR
5573 && TREE_CODE (arg1) == MULT_EXPR)
5574 || (TREE_CODE (arg1) == PLUS_EXPR
5575 && TREE_CODE (arg0) == MULT_EXPR))
5577 tree parg0, parg1, parg, marg;
5579 if (TREE_CODE (arg0) == PLUS_EXPR)
5580 parg = arg0, marg = arg1;
5582 parg = arg1, marg = arg0;
5583 parg0 = TREE_OPERAND (parg, 0);
5584 parg1 = TREE_OPERAND (parg, 1);
5588 if (TREE_CODE (parg0) == MULT_EXPR
5589 && TREE_CODE (parg1) != MULT_EXPR)
5590 return fold (build (PLUS_EXPR, type,
5591 fold (build (PLUS_EXPR, type,
5592 convert (type, parg0),
5593 convert (type, marg))),
5594 convert (type, parg1)));
5595 if (TREE_CODE (parg0) != MULT_EXPR
5596 && TREE_CODE (parg1) == MULT_EXPR)
5597 return fold (build (PLUS_EXPR, type,
5598 fold (build (PLUS_EXPR, type,
5599 convert (type, parg1),
5600 convert (type, marg))),
5601 convert (type, parg0)));
5604 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5606 tree arg00, arg01, arg10, arg11;
5607 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5609 /* (A * C) + (B * C) -> (A+B) * C.
5610 We are most concerned about the case where C is a constant,
5611 but other combinations show up during loop reduction. Since
5612 it is not difficult, try all four possibilities. */
5614 arg00 = TREE_OPERAND (arg0, 0);
5615 arg01 = TREE_OPERAND (arg0, 1);
5616 arg10 = TREE_OPERAND (arg1, 0);
5617 arg11 = TREE_OPERAND (arg1, 1);
5620 if (operand_equal_p (arg01, arg11, 0))
5621 same = arg01, alt0 = arg00, alt1 = arg10;
5622 else if (operand_equal_p (arg00, arg10, 0))
5623 same = arg00, alt0 = arg01, alt1 = arg11;
5624 else if (operand_equal_p (arg00, arg11, 0))
5625 same = arg00, alt0 = arg01, alt1 = arg10;
5626 else if (operand_equal_p (arg01, arg10, 0))
5627 same = arg01, alt0 = arg00, alt1 = arg11;
5629 /* No identical multiplicands; see if we can find a common
5630 power-of-two factor in non-power-of-two multiplies. This
5631 can help in multi-dimensional array access. */
5632 else if (TREE_CODE (arg01) == INTEGER_CST
5633 && TREE_CODE (arg11) == INTEGER_CST
5634 && TREE_INT_CST_HIGH (arg01) == 0
5635 && TREE_INT_CST_HIGH (arg11) == 0)
5637 HOST_WIDE_INT int01, int11, tmp;
5638 int01 = TREE_INT_CST_LOW (arg01);
5639 int11 = TREE_INT_CST_LOW (arg11);
5641 /* Move min of absolute values to int11. */
5642 if ((int01 >= 0 ? int01 : -int01)
5643 < (int11 >= 0 ? int11 : -int11))
5645 tmp = int01, int01 = int11, int11 = tmp;
5646 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5647 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5650 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5652 alt0 = fold (build (MULT_EXPR, type, arg00,
5653 build_int_2 (int01 / int11, 0)));
5660 return fold (build (MULT_EXPR, type,
5661 fold (build (PLUS_EXPR, type, alt0, alt1)),
5667 /* See if ARG1 is zero and X + ARG1 reduces to X. */
5668 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
5669 return non_lvalue (convert (type, arg0));
5671 /* Likewise if the operands are reversed. */
5672 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
5673 return non_lvalue (convert (type, arg1));
5675 /* Convert x+x into x*2.0. */
5676 if (operand_equal_p (arg0, arg1, 0))
5677 return fold (build (MULT_EXPR, type, arg0,
5678 build_real (type, dconst2)));
5680 /* Convert x*c+x into x*(c+1). */
5681 if (flag_unsafe_math_optimizations
5682 && TREE_CODE (arg0) == MULT_EXPR
5683 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
5684 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
5685 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
5689 c = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
5690 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
5691 return fold (build (MULT_EXPR, type, arg1,
5692 build_real (type, c)));
5695 /* Convert x+x*c into x*(c+1). */
5696 if (flag_unsafe_math_optimizations
5697 && TREE_CODE (arg1) == MULT_EXPR
5698 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
5699 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
5700 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
5704 c = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
5705 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
5706 return fold (build (MULT_EXPR, type, arg0,
5707 build_real (type, c)));
5710 /* Convert x*c1+x*c2 into x*(c1+c2). */
5711 if (flag_unsafe_math_optimizations
5712 && TREE_CODE (arg0) == MULT_EXPR
5713 && TREE_CODE (arg1) == MULT_EXPR
5714 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
5715 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
5716 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
5717 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
5718 && operand_equal_p (TREE_OPERAND (arg0, 0),
5719 TREE_OPERAND (arg1, 0), 0))
5721 REAL_VALUE_TYPE c1, c2;
5723 c1 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
5724 c2 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
5725 real_arithmetic (&c1, PLUS_EXPR, &c1, &c2);
5726 return fold (build (MULT_EXPR, type,
5727 TREE_OPERAND (arg0, 0),
5728 build_real (type, c1)));
5733 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5734 is a rotate of A by C1 bits. */
5735 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5736 is a rotate of A by B bits. */
5738 enum tree_code code0, code1;
5739 code0 = TREE_CODE (arg0);
5740 code1 = TREE_CODE (arg1);
5741 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5742 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5743 && operand_equal_p (TREE_OPERAND (arg0, 0),
5744 TREE_OPERAND (arg1, 0), 0)
5745 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5747 tree tree01, tree11;
5748 enum tree_code code01, code11;
5750 tree01 = TREE_OPERAND (arg0, 1);
5751 tree11 = TREE_OPERAND (arg1, 1);
5752 STRIP_NOPS (tree01);
5753 STRIP_NOPS (tree11);
5754 code01 = TREE_CODE (tree01);
5755 code11 = TREE_CODE (tree11);
5756 if (code01 == INTEGER_CST
5757 && code11 == INTEGER_CST
5758 && TREE_INT_CST_HIGH (tree01) == 0
5759 && TREE_INT_CST_HIGH (tree11) == 0
5760 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5761 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5762 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5763 code0 == LSHIFT_EXPR ? tree01 : tree11);
5764 else if (code11 == MINUS_EXPR)
5766 tree tree110, tree111;
5767 tree110 = TREE_OPERAND (tree11, 0);
5768 tree111 = TREE_OPERAND (tree11, 1);
5769 STRIP_NOPS (tree110);
5770 STRIP_NOPS (tree111);
5771 if (TREE_CODE (tree110) == INTEGER_CST
5772 && 0 == compare_tree_int (tree110,
5774 (TREE_TYPE (TREE_OPERAND
5776 && operand_equal_p (tree01, tree111, 0))
5777 return build ((code0 == LSHIFT_EXPR
5780 type, TREE_OPERAND (arg0, 0), tree01);
5782 else if (code01 == MINUS_EXPR)
5784 tree tree010, tree011;
5785 tree010 = TREE_OPERAND (tree01, 0);
5786 tree011 = TREE_OPERAND (tree01, 1);
5787 STRIP_NOPS (tree010);
5788 STRIP_NOPS (tree011);
5789 if (TREE_CODE (tree010) == INTEGER_CST
5790 && 0 == compare_tree_int (tree010,
5792 (TREE_TYPE (TREE_OPERAND
5794 && operand_equal_p (tree11, tree011, 0))
5795 return build ((code0 != LSHIFT_EXPR
5798 type, TREE_OPERAND (arg0, 0), tree11);
5804 /* In most languages, can't associate operations on floats through
5805 parentheses. Rather than remember where the parentheses were, we
5806 don't associate floats at all. It shouldn't matter much. However,
5807 associating multiplications is only very slightly inaccurate, so do
5808 that if -funsafe-math-optimizations is specified. */
5811 && (! FLOAT_TYPE_P (type)
5812 || (flag_unsafe_math_optimizations && code == MULT_EXPR)))
5814 tree var0, con0, lit0, minus_lit0;
5815 tree var1, con1, lit1, minus_lit1;
5817 /* Split both trees into variables, constants, and literals. Then
5818 associate each group together, the constants with literals,
5819 then the result with variables. This increases the chances of
5820 literals being recombined later and of generating relocatable
5821 expressions for the sum of a constant and literal. */
5822 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
5823 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
5824 code == MINUS_EXPR);
5826 /* Only do something if we found more than two objects. Otherwise,
5827 nothing has changed and we risk infinite recursion. */
5828 if (2 < ((var0 != 0) + (var1 != 0)
5829 + (con0 != 0) + (con1 != 0)
5830 + (lit0 != 0) + (lit1 != 0)
5831 + (minus_lit0 != 0) + (minus_lit1 != 0)))
5833 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
5834 if (code == MINUS_EXPR)
5837 var0 = associate_trees (var0, var1, code, type);
5838 con0 = associate_trees (con0, con1, code, type);
5839 lit0 = associate_trees (lit0, lit1, code, type);
5840 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
5842 /* Preserve the MINUS_EXPR if the negative part of the literal is
5843 greater than the positive part. Otherwise, the multiplicative
5844 folding code (i.e extract_muldiv) may be fooled in case
5845 unsigned constants are subtracted, like in the following
5846 example: ((X*2 + 4) - 8U)/2. */
5847 if (minus_lit0 && lit0)
5849 if (tree_int_cst_lt (lit0, minus_lit0))
5851 minus_lit0 = associate_trees (minus_lit0, lit0,
5857 lit0 = associate_trees (lit0, minus_lit0,
5865 return convert (type, associate_trees (var0, minus_lit0,
5869 con0 = associate_trees (con0, minus_lit0,
5871 return convert (type, associate_trees (var0, con0,
5876 con0 = associate_trees (con0, lit0, code, type);
5877 return convert (type, associate_trees (var0, con0, code, type));
5883 t1 = const_binop (code, arg0, arg1, 0);
5884 if (t1 != NULL_TREE)
5886 /* The return value should always have
5887 the same type as the original expression. */
5888 if (TREE_TYPE (t1) != TREE_TYPE (t))
5889 t1 = convert (TREE_TYPE (t), t1);
5896 /* A - (-B) -> A + B */
5897 if (TREE_CODE (arg1) == NEGATE_EXPR)
5898 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5899 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
5900 if (TREE_CODE (arg0) == NEGATE_EXPR
5901 && (FLOAT_TYPE_P (type)
5902 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
5903 && negate_expr_p (arg1)
5904 && (! TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
5905 && (! TREE_SIDE_EFFECTS (arg1) || TREE_CONSTANT (arg0)))
5906 return fold (build (MINUS_EXPR, type, negate_expr (arg1),
5907 TREE_OPERAND (arg0, 0)));
5909 if (! FLOAT_TYPE_P (type))
5911 if (! wins && integer_zerop (arg0))
5912 return negate_expr (convert (type, arg1));
5913 if (integer_zerop (arg1))
5914 return non_lvalue (convert (type, arg0));
5916 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5917 about the case where C is a constant, just try one of the
5918 four possibilities. */
5920 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5921 && operand_equal_p (TREE_OPERAND (arg0, 1),
5922 TREE_OPERAND (arg1, 1), 0))
5923 return fold (build (MULT_EXPR, type,
5924 fold (build (MINUS_EXPR, type,
5925 TREE_OPERAND (arg0, 0),
5926 TREE_OPERAND (arg1, 0))),
5927 TREE_OPERAND (arg0, 1)));
5929 /* Fold A - (A & B) into ~B & A. */
5930 if (!TREE_SIDE_EFFECTS (arg0)
5931 && TREE_CODE (arg1) == BIT_AND_EXPR)
5933 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
5934 return fold (build (BIT_AND_EXPR, type,
5935 fold (build1 (BIT_NOT_EXPR, type,
5936 TREE_OPERAND (arg1, 0))),
5938 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
5939 return fold (build (BIT_AND_EXPR, type,
5940 fold (build1 (BIT_NOT_EXPR, type,
5941 TREE_OPERAND (arg1, 1))),
5946 /* See if ARG1 is zero and X - ARG1 reduces to X. */
5947 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
5948 return non_lvalue (convert (type, arg0));
5950 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
5951 ARG0 is zero and X + ARG0 reduces to X, since that would mean
5952 (-ARG1 + ARG0) reduces to -ARG1. */
5953 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
5954 return negate_expr (convert (type, arg1));
5956 /* Fold &x - &x. This can happen from &x.foo - &x.
5957 This is unsafe for certain floats even in non-IEEE formats.
5958 In IEEE, it is unsafe because it does wrong for NaNs.
5959 Also note that operand_equal_p is always false if an operand
5962 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
5963 && operand_equal_p (arg0, arg1, 0))
5964 return convert (type, integer_zero_node);
5969 /* (-A) * (-B) -> A * B */
5970 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5971 return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
5972 TREE_OPERAND (arg1, 0)));
5974 if (! FLOAT_TYPE_P (type))
5976 if (integer_zerop (arg1))
5977 return omit_one_operand (type, arg1, arg0);
5978 if (integer_onep (arg1))
5979 return non_lvalue (convert (type, arg0));
5981 /* (a * (1 << b)) is (a << b) */
5982 if (TREE_CODE (arg1) == LSHIFT_EXPR
5983 && integer_onep (TREE_OPERAND (arg1, 0)))
5984 return fold (build (LSHIFT_EXPR, type, arg0,
5985 TREE_OPERAND (arg1, 1)));
5986 if (TREE_CODE (arg0) == LSHIFT_EXPR
5987 && integer_onep (TREE_OPERAND (arg0, 0)))
5988 return fold (build (LSHIFT_EXPR, type, arg1,
5989 TREE_OPERAND (arg0, 1)));
5991 if (TREE_CODE (arg1) == INTEGER_CST
5992 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
5993 convert (type, arg1),
5995 return convert (type, tem);
6000 /* Maybe fold x * 0 to 0. The expressions aren't the same
6001 when x is NaN, since x * 0 is also NaN. Nor are they the
6002 same in modes with signed zeros, since multiplying a
6003 negative value by 0 gives -0, not +0. */
6004 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
6005 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
6006 && real_zerop (arg1))
6007 return omit_one_operand (type, arg1, arg0);
6008 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
6009 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6010 && real_onep (arg1))
6011 return non_lvalue (convert (type, arg0));
6013 /* Transform x * -1.0 into -x. */
6014 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6015 && real_minus_onep (arg1))
6016 return fold (build1 (NEGATE_EXPR, type, arg0));
6018 if (flag_unsafe_math_optimizations)
6020 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
6021 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
6023 /* Optimizations of sqrt(...)*sqrt(...). */
6024 if ((fcode0 == BUILT_IN_SQRT && fcode1 == BUILT_IN_SQRT)
6025 || (fcode0 == BUILT_IN_SQRTF && fcode1 == BUILT_IN_SQRTF)
6026 || (fcode0 == BUILT_IN_SQRTL && fcode1 == BUILT_IN_SQRTL))
6028 tree sqrtfn, arg, arglist;
6029 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6030 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6032 /* Optimize sqrt(x)*sqrt(x) as x. */
6033 if (operand_equal_p (arg00, arg10, 0)
6034 && ! HONOR_SNANS (TYPE_MODE (type)))
6037 /* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */
6038 sqrtfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6039 arg = fold (build (MULT_EXPR, type, arg00, arg10));
6040 arglist = build_tree_list (NULL_TREE, arg);
6041 return build_function_call_expr (sqrtfn, arglist);
6044 /* Optimize exp(x)*exp(y) as exp(x+y). */
6045 if ((fcode0 == BUILT_IN_EXP && fcode1 == BUILT_IN_EXP)
6046 || (fcode0 == BUILT_IN_EXPF && fcode1 == BUILT_IN_EXPF)
6047 || (fcode0 == BUILT_IN_EXPL && fcode1 == BUILT_IN_EXPL))
6049 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6050 tree arg = build (PLUS_EXPR, type,
6051 TREE_VALUE (TREE_OPERAND (arg0, 1)),
6052 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6053 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6054 return build_function_call_expr (expfn, arglist);
6057 /* Optimizations of pow(...)*pow(...). */
6058 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
6059 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
6060 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
6062 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6063 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
6065 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6066 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
6069 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
6070 if (operand_equal_p (arg01, arg11, 0))
6072 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6073 tree arg = build (MULT_EXPR, type, arg00, arg10);
6074 tree arglist = tree_cons (NULL_TREE, fold (arg),
6075 build_tree_list (NULL_TREE,
6077 return build_function_call_expr (powfn, arglist);
6080 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
6081 if (operand_equal_p (arg00, arg10, 0))
6083 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6084 tree arg = fold (build (PLUS_EXPR, type, arg01, arg11));
6085 tree arglist = tree_cons (NULL_TREE, arg00,
6086 build_tree_list (NULL_TREE,
6088 return build_function_call_expr (powfn, arglist);
6092 /* Optimize tan(x)*cos(x) as sin(x). */
6093 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
6094 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
6095 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
6096 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
6097 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
6098 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
6099 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6100 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6108 sinfn = implicit_built_in_decls[BUILT_IN_SIN];
6112 sinfn = implicit_built_in_decls[BUILT_IN_SINF];
6116 sinfn = implicit_built_in_decls[BUILT_IN_SINL];
6122 if (sinfn != NULL_TREE)
6123 return build_function_call_expr (sinfn,
6124 TREE_OPERAND (arg0, 1));
6127 /* Optimize x*pow(x,c) as pow(x,c+1). */
6128 if (fcode1 == BUILT_IN_POW
6129 || fcode1 == BUILT_IN_POWF
6130 || fcode1 == BUILT_IN_POWL)
6132 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6133 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
6135 if (TREE_CODE (arg11) == REAL_CST
6136 && ! TREE_CONSTANT_OVERFLOW (arg11)
6137 && operand_equal_p (arg0, arg10, 0))
6139 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6143 c = TREE_REAL_CST (arg11);
6144 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6145 arg = build_real (type, c);
6146 arglist = build_tree_list (NULL_TREE, arg);
6147 arglist = tree_cons (NULL_TREE, arg0, arglist);
6148 return build_function_call_expr (powfn, arglist);
6152 /* Optimize pow(x,c)*x as pow(x,c+1). */
6153 if (fcode0 == BUILT_IN_POW
6154 || fcode0 == BUILT_IN_POWF
6155 || fcode0 == BUILT_IN_POWL)
6157 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6158 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
6160 if (TREE_CODE (arg01) == REAL_CST
6161 && ! TREE_CONSTANT_OVERFLOW (arg01)
6162 && operand_equal_p (arg1, arg00, 0))
6164 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6168 c = TREE_REAL_CST (arg01);
6169 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6170 arg = build_real (type, c);
6171 arglist = build_tree_list (NULL_TREE, arg);
6172 arglist = tree_cons (NULL_TREE, arg1, arglist);
6173 return build_function_call_expr (powfn, arglist);
6177 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
6179 && operand_equal_p (arg0, arg1, 0))
6183 if (type == double_type_node)
6184 powfn = implicit_built_in_decls[BUILT_IN_POW];
6185 else if (type == float_type_node)
6186 powfn = implicit_built_in_decls[BUILT_IN_POWF];
6187 else if (type == long_double_type_node)
6188 powfn = implicit_built_in_decls[BUILT_IN_POWL];
6194 tree arg = build_real (type, dconst2);
6195 tree arglist = build_tree_list (NULL_TREE, arg);
6196 arglist = tree_cons (NULL_TREE, arg0, arglist);
6197 return build_function_call_expr (powfn, arglist);
6206 if (integer_all_onesp (arg1))
6207 return omit_one_operand (type, arg1, arg0);
6208 if (integer_zerop (arg1))
6209 return non_lvalue (convert (type, arg0));
6210 t1 = distribute_bit_expr (code, type, arg0, arg1);
6211 if (t1 != NULL_TREE)
6214 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
6216 This results in more efficient code for machines without a NAND
6217 instruction. Combine will canonicalize to the first form
6218 which will allow use of NAND instructions provided by the
6219 backend if they exist. */
6220 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6221 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6223 return fold (build1 (BIT_NOT_EXPR, type,
6224 build (BIT_AND_EXPR, type,
6225 TREE_OPERAND (arg0, 0),
6226 TREE_OPERAND (arg1, 0))));
6229 /* See if this can be simplified into a rotate first. If that
6230 is unsuccessful continue in the association code. */
6234 if (integer_zerop (arg1))
6235 return non_lvalue (convert (type, arg0));
6236 if (integer_all_onesp (arg1))
6237 return fold (build1 (BIT_NOT_EXPR, type, arg0));
6239 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
6240 with a constant, and the two constants have no bits in common,
6241 we should treat this as a BIT_IOR_EXPR since this may produce more
6243 if (TREE_CODE (arg0) == BIT_AND_EXPR
6244 && TREE_CODE (arg1) == BIT_AND_EXPR
6245 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6246 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
6247 && integer_zerop (const_binop (BIT_AND_EXPR,
6248 TREE_OPERAND (arg0, 1),
6249 TREE_OPERAND (arg1, 1), 0)))
6251 code = BIT_IOR_EXPR;
6255 /* See if this can be simplified into a rotate first. If that
6256 is unsuccessful continue in the association code. */
6261 if (integer_all_onesp (arg1))
6262 return non_lvalue (convert (type, arg0));
6263 if (integer_zerop (arg1))
6264 return omit_one_operand (type, arg1, arg0);
6265 t1 = distribute_bit_expr (code, type, arg0, arg1);
6266 if (t1 != NULL_TREE)
6268 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
6269 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
6270 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6273 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
6275 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
6276 && (~TREE_INT_CST_LOW (arg1)
6277 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
6278 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
6281 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
6283 This results in more efficient code for machines without a NOR
6284 instruction. Combine will canonicalize to the first form
6285 which will allow use of NOR instructions provided by the
6286 backend if they exist. */
6287 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6288 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6290 return fold (build1 (BIT_NOT_EXPR, type,
6291 build (BIT_IOR_EXPR, type,
6292 TREE_OPERAND (arg0, 0),
6293 TREE_OPERAND (arg1, 0))));
6298 case BIT_ANDTC_EXPR:
6299 if (integer_all_onesp (arg0))
6300 return non_lvalue (convert (type, arg1));
6301 if (integer_zerop (arg0))
6302 return omit_one_operand (type, arg0, arg1);
6303 if (TREE_CODE (arg1) == INTEGER_CST)
6305 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
6306 code = BIT_AND_EXPR;
6312 /* Don't touch a floating-point divide by zero unless the mode
6313 of the constant can represent infinity. */
6314 if (TREE_CODE (arg1) == REAL_CST
6315 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
6316 && real_zerop (arg1))
6319 /* (-A) / (-B) -> A / B */
6320 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
6321 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
6322 TREE_OPERAND (arg1, 0)));
6324 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
6325 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6326 && real_onep (arg1))
6327 return non_lvalue (convert (type, arg0));
6329 /* If ARG1 is a constant, we can convert this to a multiply by the
6330 reciprocal. This does not have the same rounding properties,
6331 so only do this if -funsafe-math-optimizations. We can actually
6332 always safely do it if ARG1 is a power of two, but it's hard to
6333 tell if it is or not in a portable manner. */
6334 if (TREE_CODE (arg1) == REAL_CST)
6336 if (flag_unsafe_math_optimizations
6337 && 0 != (tem = const_binop (code, build_real (type, dconst1),
6339 return fold (build (MULT_EXPR, type, arg0, tem));
6340 /* Find the reciprocal if optimizing and the result is exact. */
6344 r = TREE_REAL_CST (arg1);
6345 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
6347 tem = build_real (type, r);
6348 return fold (build (MULT_EXPR, type, arg0, tem));
6352 /* Convert A/B/C to A/(B*C). */
6353 if (flag_unsafe_math_optimizations
6354 && TREE_CODE (arg0) == RDIV_EXPR)
6356 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
6357 build (MULT_EXPR, type, TREE_OPERAND (arg0, 1),
6360 /* Convert A/(B/C) to (A/B)*C. */
6361 if (flag_unsafe_math_optimizations
6362 && TREE_CODE (arg1) == RDIV_EXPR)
6364 return fold (build (MULT_EXPR, type,
6365 build (RDIV_EXPR, type, arg0,
6366 TREE_OPERAND (arg1, 0)),
6367 TREE_OPERAND (arg1, 1)));
6370 if (flag_unsafe_math_optimizations)
6372 enum built_in_function fcode = builtin_mathfn_code (arg1);
6373 /* Optimize x/exp(y) into x*exp(-y). */
6374 if (fcode == BUILT_IN_EXP
6375 || fcode == BUILT_IN_EXPF
6376 || fcode == BUILT_IN_EXPL)
6378 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6379 tree arg = build1 (NEGATE_EXPR, type,
6380 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6381 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6382 arg1 = build_function_call_expr (expfn, arglist);
6383 return fold (build (MULT_EXPR, type, arg0, arg1));
6386 /* Optimize x/pow(y,z) into x*pow(y,-z). */
6387 if (fcode == BUILT_IN_POW
6388 || fcode == BUILT_IN_POWF
6389 || fcode == BUILT_IN_POWL)
6391 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6392 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6393 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
6394 tree neg11 = fold (build1 (NEGATE_EXPR, type, arg11));
6395 tree arglist = tree_cons(NULL_TREE, arg10,
6396 build_tree_list (NULL_TREE, neg11));
6397 arg1 = build_function_call_expr (powfn, arglist);
6398 return fold (build (MULT_EXPR, type, arg0, arg1));
6402 if (flag_unsafe_math_optimizations)
6404 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
6405 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
6407 /* Optimize sin(x)/cos(x) as tan(x). */
6408 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
6409 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
6410 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
6411 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6412 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6416 if (fcode0 == BUILT_IN_SIN)
6417 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6418 else if (fcode0 == BUILT_IN_SINF)
6419 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6420 else if (fcode0 == BUILT_IN_SINL)
6421 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6425 if (tanfn != NULL_TREE)
6426 return build_function_call_expr (tanfn,
6427 TREE_OPERAND (arg0, 1));
6430 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
6431 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
6432 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
6433 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
6434 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6435 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6439 if (fcode0 == BUILT_IN_COS)
6440 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6441 else if (fcode0 == BUILT_IN_COSF)
6442 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6443 else if (fcode0 == BUILT_IN_COSL)
6444 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6448 if (tanfn != NULL_TREE)
6450 tree tmp = TREE_OPERAND (arg0, 1);
6451 tmp = build_function_call_expr (tanfn, tmp);
6452 return fold (build (RDIV_EXPR, type,
6453 build_real (type, dconst1),
6458 /* Optimize pow(x,c)/x as pow(x,c-1). */
6459 if (fcode0 == BUILT_IN_POW
6460 || fcode0 == BUILT_IN_POWF
6461 || fcode0 == BUILT_IN_POWL)
6463 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6464 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
6465 if (TREE_CODE (arg01) == REAL_CST
6466 && ! TREE_CONSTANT_OVERFLOW (arg01)
6467 && operand_equal_p (arg1, arg00, 0))
6469 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6473 c = TREE_REAL_CST (arg01);
6474 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
6475 arg = build_real (type, c);
6476 arglist = build_tree_list (NULL_TREE, arg);
6477 arglist = tree_cons (NULL_TREE, arg1, arglist);
6478 return build_function_call_expr (powfn, arglist);
6484 case TRUNC_DIV_EXPR:
6485 case ROUND_DIV_EXPR:
6486 case FLOOR_DIV_EXPR:
6488 case EXACT_DIV_EXPR:
6489 if (integer_onep (arg1))
6490 return non_lvalue (convert (type, arg0));
6491 if (integer_zerop (arg1))
6494 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
6495 operation, EXACT_DIV_EXPR.
6497 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
6498 At one time others generated faster code, it's not clear if they do
6499 after the last round to changes to the DIV code in expmed.c. */
6500 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
6501 && multiple_of_p (type, arg0, arg1))
6502 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
6504 if (TREE_CODE (arg1) == INTEGER_CST
6505 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6507 return convert (type, tem);
6512 case FLOOR_MOD_EXPR:
6513 case ROUND_MOD_EXPR:
6514 case TRUNC_MOD_EXPR:
6515 if (integer_onep (arg1))
6516 return omit_one_operand (type, integer_zero_node, arg0);
6517 if (integer_zerop (arg1))
6520 if (TREE_CODE (arg1) == INTEGER_CST
6521 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6523 return convert (type, tem);
6529 if (integer_all_onesp (arg0))
6530 return omit_one_operand (type, arg0, arg1);
6534 /* Optimize -1 >> x for arithmetic right shifts. */
6535 if (integer_all_onesp (arg0) && ! TREE_UNSIGNED (type))
6536 return omit_one_operand (type, arg0, arg1);
6537 /* ... fall through ... */
6541 if (integer_zerop (arg1))
6542 return non_lvalue (convert (type, arg0));
6543 if (integer_zerop (arg0))
6544 return omit_one_operand (type, arg0, arg1);
6546 /* Since negative shift count is not well-defined,
6547 don't try to compute it in the compiler. */
6548 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
6550 /* Rewrite an LROTATE_EXPR by a constant into an
6551 RROTATE_EXPR by a new constant. */
6552 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
6556 TREE_SET_CODE (t, RROTATE_EXPR);
6557 code = RROTATE_EXPR;
6558 TREE_OPERAND (t, 1) = arg1
6561 convert (TREE_TYPE (arg1),
6562 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
6564 if (tree_int_cst_sgn (arg1) < 0)
6568 /* If we have a rotate of a bit operation with the rotate count and
6569 the second operand of the bit operation both constant,
6570 permute the two operations. */
6571 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6572 && (TREE_CODE (arg0) == BIT_AND_EXPR
6573 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
6574 || TREE_CODE (arg0) == BIT_IOR_EXPR
6575 || TREE_CODE (arg0) == BIT_XOR_EXPR)
6576 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6577 return fold (build (TREE_CODE (arg0), type,
6578 fold (build (code, type,
6579 TREE_OPERAND (arg0, 0), arg1)),
6580 fold (build (code, type,
6581 TREE_OPERAND (arg0, 1), arg1))));
6583 /* Two consecutive rotates adding up to the width of the mode can
6585 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6586 && TREE_CODE (arg0) == RROTATE_EXPR
6587 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6588 && TREE_INT_CST_HIGH (arg1) == 0
6589 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
6590 && ((TREE_INT_CST_LOW (arg1)
6591 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
6592 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
6593 return TREE_OPERAND (arg0, 0);
6598 if (operand_equal_p (arg0, arg1, 0))
6599 return omit_one_operand (type, arg0, arg1);
6600 if (INTEGRAL_TYPE_P (type)
6601 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
6602 return omit_one_operand (type, arg1, arg0);
6606 if (operand_equal_p (arg0, arg1, 0))
6607 return omit_one_operand (type, arg0, arg1);
6608 if (INTEGRAL_TYPE_P (type)
6609 && TYPE_MAX_VALUE (type)
6610 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
6611 return omit_one_operand (type, arg1, arg0);
6614 case TRUTH_NOT_EXPR:
6615 /* Note that the operand of this must be an int
6616 and its values must be 0 or 1.
6617 ("true" is a fixed value perhaps depending on the language,
6618 but we don't handle values other than 1 correctly yet.) */
6619 tem = invert_truthvalue (arg0);
6620 /* Avoid infinite recursion. */
6621 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
6623 tem = fold_single_bit_test (code, arg0, arg1, type);
6628 return convert (type, tem);
6630 case TRUTH_ANDIF_EXPR:
6631 /* Note that the operands of this must be ints
6632 and their values must be 0 or 1.
6633 ("true" is a fixed value perhaps depending on the language.) */
6634 /* If first arg is constant zero, return it. */
6635 if (integer_zerop (arg0))
6636 return convert (type, arg0);
6637 case TRUTH_AND_EXPR:
6638 /* If either arg is constant true, drop it. */
6639 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6640 return non_lvalue (convert (type, arg1));
6641 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
6642 /* Preserve sequence points. */
6643 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6644 return non_lvalue (convert (type, arg0));
6645 /* If second arg is constant zero, result is zero, but first arg
6646 must be evaluated. */
6647 if (integer_zerop (arg1))
6648 return omit_one_operand (type, arg1, arg0);
6649 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
6650 case will be handled here. */
6651 if (integer_zerop (arg0))
6652 return omit_one_operand (type, arg0, arg1);
6655 /* We only do these simplifications if we are optimizing. */
6659 /* Check for things like (A || B) && (A || C). We can convert this
6660 to A || (B && C). Note that either operator can be any of the four
6661 truth and/or operations and the transformation will still be
6662 valid. Also note that we only care about order for the
6663 ANDIF and ORIF operators. If B contains side effects, this
6664 might change the truth-value of A. */
6665 if (TREE_CODE (arg0) == TREE_CODE (arg1)
6666 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
6667 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
6668 || TREE_CODE (arg0) == TRUTH_AND_EXPR
6669 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
6670 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
6672 tree a00 = TREE_OPERAND (arg0, 0);
6673 tree a01 = TREE_OPERAND (arg0, 1);
6674 tree a10 = TREE_OPERAND (arg1, 0);
6675 tree a11 = TREE_OPERAND (arg1, 1);
6676 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
6677 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
6678 && (code == TRUTH_AND_EXPR
6679 || code == TRUTH_OR_EXPR));
6681 if (operand_equal_p (a00, a10, 0))
6682 return fold (build (TREE_CODE (arg0), type, a00,
6683 fold (build (code, type, a01, a11))));
6684 else if (commutative && operand_equal_p (a00, a11, 0))
6685 return fold (build (TREE_CODE (arg0), type, a00,
6686 fold (build (code, type, a01, a10))));
6687 else if (commutative && operand_equal_p (a01, a10, 0))
6688 return fold (build (TREE_CODE (arg0), type, a01,
6689 fold (build (code, type, a00, a11))));
6691 /* This case if tricky because we must either have commutative
6692 operators or else A10 must not have side-effects. */
6694 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
6695 && operand_equal_p (a01, a11, 0))
6696 return fold (build (TREE_CODE (arg0), type,
6697 fold (build (code, type, a00, a10)),
6701 /* See if we can build a range comparison. */
6702 if (0 != (tem = fold_range_test (t)))
6705 /* Check for the possibility of merging component references. If our
6706 lhs is another similar operation, try to merge its rhs with our
6707 rhs. Then try to merge our lhs and rhs. */
6708 if (TREE_CODE (arg0) == code
6709 && 0 != (tem = fold_truthop (code, type,
6710 TREE_OPERAND (arg0, 1), arg1)))
6711 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6713 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
6718 case TRUTH_ORIF_EXPR:
6719 /* Note that the operands of this must be ints
6720 and their values must be 0 or true.
6721 ("true" is a fixed value perhaps depending on the language.) */
6722 /* If first arg is constant true, return it. */
6723 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6724 return convert (type, arg0);
6726 /* If either arg is constant zero, drop it. */
6727 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
6728 return non_lvalue (convert (type, arg1));
6729 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
6730 /* Preserve sequence points. */
6731 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6732 return non_lvalue (convert (type, arg0));
6733 /* If second arg is constant true, result is true, but we must
6734 evaluate first arg. */
6735 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
6736 return omit_one_operand (type, arg1, arg0);
6737 /* Likewise for first arg, but note this only occurs here for
6739 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6740 return omit_one_operand (type, arg0, arg1);
6743 case TRUTH_XOR_EXPR:
6744 /* If either arg is constant zero, drop it. */
6745 if (integer_zerop (arg0))
6746 return non_lvalue (convert (type, arg1));
6747 if (integer_zerop (arg1))
6748 return non_lvalue (convert (type, arg0));
6749 /* If either arg is constant true, this is a logical inversion. */
6750 if (integer_onep (arg0))
6751 return non_lvalue (convert (type, invert_truthvalue (arg1)));
6752 if (integer_onep (arg1))
6753 return non_lvalue (convert (type, invert_truthvalue (arg0)));
6762 /* If one arg is a real or integer constant, put it last. */
6763 if ((TREE_CODE (arg0) == INTEGER_CST
6764 && TREE_CODE (arg1) != INTEGER_CST)
6765 || (TREE_CODE (arg0) == REAL_CST
6766 && TREE_CODE (arg0) != REAL_CST))
6770 TREE_OPERAND (t, 0) = arg1;
6771 TREE_OPERAND (t, 1) = arg0;
6772 arg0 = TREE_OPERAND (t, 0);
6773 arg1 = TREE_OPERAND (t, 1);
6774 code = swap_tree_comparison (code);
6775 TREE_SET_CODE (t, code);
6778 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
6780 tree targ0 = strip_float_extensions (arg0);
6781 tree targ1 = strip_float_extensions (arg1);
6782 tree newtype = TREE_TYPE (targ0);
6784 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
6785 newtype = TREE_TYPE (targ1);
6787 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
6788 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
6789 return fold (build (code, type, convert (newtype, targ0),
6790 convert (newtype, targ1)));
6792 /* (-a) CMP (-b) -> b CMP a */
6793 if (TREE_CODE (arg0) == NEGATE_EXPR
6794 && TREE_CODE (arg1) == NEGATE_EXPR)
6795 return fold (build (code, type, TREE_OPERAND (arg1, 0),
6796 TREE_OPERAND (arg0, 0)));
6798 if (TREE_CODE (arg1) == REAL_CST)
6800 REAL_VALUE_TYPE cst;
6801 cst = TREE_REAL_CST (arg1);
6803 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6804 if (TREE_CODE (arg0) == NEGATE_EXPR)
6806 fold (build (swap_tree_comparison (code), type,
6807 TREE_OPERAND (arg0, 0),
6808 build_real (TREE_TYPE (arg1),
6809 REAL_VALUE_NEGATE (cst))));
6811 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6812 /* a CMP (-0) -> a CMP 0 */
6813 if (REAL_VALUE_MINUS_ZERO (cst))
6814 return fold (build (code, type, arg0,
6815 build_real (TREE_TYPE (arg1), dconst0)));
6817 /* x != NaN is always true, other ops are always false. */
6818 if (REAL_VALUE_ISNAN (cst)
6819 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
6821 t = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
6822 return omit_one_operand (type, convert (type, t), arg0);
6825 /* Fold comparisons against infinity. */
6826 if (REAL_VALUE_ISINF (cst))
6828 tem = fold_inf_compare (code, type, arg0, arg1);
6829 if (tem != NULL_TREE)
6834 /* If this is a comparison of a real constant with a PLUS_EXPR
6835 or a MINUS_EXPR of a real constant, we can convert it into a
6836 comparison with a revised real constant as long as no overflow
6837 occurs when unsafe_math_optimizations are enabled. */
6838 if (flag_unsafe_math_optimizations
6839 && TREE_CODE (arg1) == REAL_CST
6840 && (TREE_CODE (arg0) == PLUS_EXPR
6841 || TREE_CODE (arg0) == MINUS_EXPR)
6842 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6843 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6844 ? MINUS_EXPR : PLUS_EXPR,
6845 arg1, TREE_OPERAND (arg0, 1), 0))
6846 && ! TREE_CONSTANT_OVERFLOW (tem))
6847 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6849 /* Likewise, we can simplify a comparison of a real constant with
6850 a MINUS_EXPR whose first operand is also a real constant, i.e.
6851 (c1 - x) < c2 becomes x > c1-c2. */
6852 if (flag_unsafe_math_optimizations
6853 && TREE_CODE (arg1) == REAL_CST
6854 && TREE_CODE (arg0) == MINUS_EXPR
6855 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
6856 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
6858 && ! TREE_CONSTANT_OVERFLOW (tem))
6859 return fold (build (swap_tree_comparison (code), type,
6860 TREE_OPERAND (arg0, 1), tem));
6862 /* Fold comparisons against built-in math functions. */
6863 if (TREE_CODE (arg1) == REAL_CST
6864 && flag_unsafe_math_optimizations
6865 && ! flag_errno_math)
6867 enum built_in_function fcode = builtin_mathfn_code (arg0);
6869 if (fcode != END_BUILTINS)
6871 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
6872 if (tem != NULL_TREE)
6878 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6879 First, see if one arg is constant; find the constant arg
6880 and the other one. */
6882 tree constop = 0, varop = NULL_TREE;
6883 int constopnum = -1;
6885 if (TREE_CONSTANT (arg1))
6886 constopnum = 1, constop = arg1, varop = arg0;
6887 if (TREE_CONSTANT (arg0))
6888 constopnum = 0, constop = arg0, varop = arg1;
6890 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
6892 /* This optimization is invalid for ordered comparisons
6893 if CONST+INCR overflows or if foo+incr might overflow.
6894 This optimization is invalid for floating point due to rounding.
6895 For pointer types we assume overflow doesn't happen. */
6896 if (POINTER_TYPE_P (TREE_TYPE (varop))
6897 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6898 && (code == EQ_EXPR || code == NE_EXPR)))
6901 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
6902 constop, TREE_OPERAND (varop, 1)));
6904 /* Do not overwrite the current varop to be a preincrement,
6905 create a new node so that we won't confuse our caller who
6906 might create trees and throw them away, reusing the
6907 arguments that they passed to build. This shows up in
6908 the THEN or ELSE parts of ?: being postincrements. */
6909 varop = build (PREINCREMENT_EXPR, TREE_TYPE (varop),
6910 TREE_OPERAND (varop, 0),
6911 TREE_OPERAND (varop, 1));
6913 /* If VAROP is a reference to a bitfield, we must mask
6914 the constant by the width of the field. */
6915 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6916 && DECL_BIT_FIELD(TREE_OPERAND
6917 (TREE_OPERAND (varop, 0), 1)))
6920 = TREE_INT_CST_LOW (DECL_SIZE
6922 (TREE_OPERAND (varop, 0), 1)));
6923 tree mask, unsigned_type;
6924 unsigned int precision;
6925 tree folded_compare;
6927 /* First check whether the comparison would come out
6928 always the same. If we don't do that we would
6929 change the meaning with the masking. */
6930 if (constopnum == 0)
6931 folded_compare = fold (build (code, type, constop,
6932 TREE_OPERAND (varop, 0)));
6934 folded_compare = fold (build (code, type,
6935 TREE_OPERAND (varop, 0),
6937 if (integer_zerop (folded_compare)
6938 || integer_onep (folded_compare))
6939 return omit_one_operand (type, folded_compare, varop);
6941 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
6942 precision = TYPE_PRECISION (unsigned_type);
6943 mask = build_int_2 (~0, ~0);
6944 TREE_TYPE (mask) = unsigned_type;
6945 force_fit_type (mask, 0);
6946 mask = const_binop (RSHIFT_EXPR, mask,
6947 size_int (precision - size), 0);
6948 newconst = fold (build (BIT_AND_EXPR,
6949 TREE_TYPE (varop), newconst,
6950 convert (TREE_TYPE (varop),
6954 t = build (code, type,
6955 (constopnum == 0) ? newconst : varop,
6956 (constopnum == 1) ? newconst : varop);
6960 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
6962 if (POINTER_TYPE_P (TREE_TYPE (varop))
6963 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6964 && (code == EQ_EXPR || code == NE_EXPR)))
6967 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
6968 constop, TREE_OPERAND (varop, 1)));
6970 /* Do not overwrite the current varop to be a predecrement,
6971 create a new node so that we won't confuse our caller who
6972 might create trees and throw them away, reusing the
6973 arguments that they passed to build. This shows up in
6974 the THEN or ELSE parts of ?: being postdecrements. */
6975 varop = build (PREDECREMENT_EXPR, TREE_TYPE (varop),
6976 TREE_OPERAND (varop, 0),
6977 TREE_OPERAND (varop, 1));
6979 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6980 && DECL_BIT_FIELD(TREE_OPERAND
6981 (TREE_OPERAND (varop, 0), 1)))
6984 = TREE_INT_CST_LOW (DECL_SIZE
6986 (TREE_OPERAND (varop, 0), 1)));
6987 tree mask, unsigned_type;
6988 unsigned int precision;
6989 tree folded_compare;
6991 if (constopnum == 0)
6992 folded_compare = fold (build (code, type, constop,
6993 TREE_OPERAND (varop, 0)));
6995 folded_compare = fold (build (code, type,
6996 TREE_OPERAND (varop, 0),
6998 if (integer_zerop (folded_compare)
6999 || integer_onep (folded_compare))
7000 return omit_one_operand (type, folded_compare, varop);
7002 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
7003 precision = TYPE_PRECISION (unsigned_type);
7004 mask = build_int_2 (~0, ~0);
7005 TREE_TYPE (mask) = TREE_TYPE (varop);
7006 force_fit_type (mask, 0);
7007 mask = const_binop (RSHIFT_EXPR, mask,
7008 size_int (precision - size), 0);
7009 newconst = fold (build (BIT_AND_EXPR,
7010 TREE_TYPE (varop), newconst,
7011 convert (TREE_TYPE (varop),
7015 t = build (code, type,
7016 (constopnum == 0) ? newconst : varop,
7017 (constopnum == 1) ? newconst : varop);
7023 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
7024 This transformation affects the cases which are handled in later
7025 optimizations involving comparisons with non-negative constants. */
7026 if (TREE_CODE (arg1) == INTEGER_CST
7027 && TREE_CODE (arg0) != INTEGER_CST
7028 && tree_int_cst_sgn (arg1) > 0)
7034 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7035 t = build (code, type, TREE_OPERAND (t, 0), arg1);
7040 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7041 t = build (code, type, TREE_OPERAND (t, 0), arg1);
7049 /* Comparisons with the highest or lowest possible integer of
7050 the specified size will have known values. */
7052 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
7054 if (TREE_CODE (arg1) == INTEGER_CST
7055 && ! TREE_CONSTANT_OVERFLOW (arg1)
7056 && width <= HOST_BITS_PER_WIDE_INT
7057 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
7058 || POINTER_TYPE_P (TREE_TYPE (arg1))))
7060 unsigned HOST_WIDE_INT signed_max;
7061 unsigned HOST_WIDE_INT max, min;
7063 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
7065 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7067 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
7073 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
7076 if (TREE_INT_CST_HIGH (arg1) == 0
7077 && TREE_INT_CST_LOW (arg1) == max)
7081 return omit_one_operand (type,
7082 convert (type, integer_zero_node),
7088 TREE_SET_CODE (t, EQ_EXPR);
7091 return omit_one_operand (type,
7092 convert (type, integer_one_node),
7098 TREE_SET_CODE (t, NE_EXPR);
7101 /* The GE_EXPR and LT_EXPR cases above are not normally
7102 reached because of previous transformations. */
7107 else if (TREE_INT_CST_HIGH (arg1) == 0
7108 && TREE_INT_CST_LOW (arg1) == max - 1)
7113 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
7114 t = build (code, type, TREE_OPERAND (t, 0), arg1);
7118 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
7119 t = build (code, type, TREE_OPERAND (t, 0), arg1);
7124 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
7125 && TREE_INT_CST_LOW (arg1) == min)
7129 return omit_one_operand (type,
7130 convert (type, integer_zero_node),
7136 TREE_SET_CODE (t, EQ_EXPR);
7140 return omit_one_operand (type,
7141 convert (type, integer_one_node),
7147 TREE_SET_CODE (t, NE_EXPR);
7153 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
7154 && TREE_INT_CST_LOW (arg1) == min + 1)
7159 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7160 t = build (code, type, TREE_OPERAND (t, 0), arg1);
7164 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7165 t = build (code, type, TREE_OPERAND (t, 0), arg1);
7171 else if (TREE_INT_CST_HIGH (arg1) == 0
7172 && TREE_INT_CST_LOW (arg1) == signed_max
7173 && TREE_UNSIGNED (TREE_TYPE (arg1))
7174 /* signed_type does not work on pointer types. */
7175 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
7177 /* The following case also applies to X < signed_max+1
7178 and X >= signed_max+1 because previous transformations. */
7179 if (code == LE_EXPR || code == GT_EXPR)
7182 st0 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg0));
7183 st1 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg1));
7185 (build (code == LE_EXPR ? GE_EXPR: LT_EXPR,
7186 type, convert (st0, arg0),
7187 convert (st1, integer_zero_node)));
7193 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
7194 a MINUS_EXPR of a constant, we can convert it into a comparison with
7195 a revised constant as long as no overflow occurs. */
7196 if ((code == EQ_EXPR || code == NE_EXPR)
7197 && TREE_CODE (arg1) == INTEGER_CST
7198 && (TREE_CODE (arg0) == PLUS_EXPR
7199 || TREE_CODE (arg0) == MINUS_EXPR)
7200 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7201 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
7202 ? MINUS_EXPR : PLUS_EXPR,
7203 arg1, TREE_OPERAND (arg0, 1), 0))
7204 && ! TREE_CONSTANT_OVERFLOW (tem))
7205 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7207 /* Similarly for a NEGATE_EXPR. */
7208 else if ((code == EQ_EXPR || code == NE_EXPR)
7209 && TREE_CODE (arg0) == NEGATE_EXPR
7210 && TREE_CODE (arg1) == INTEGER_CST
7211 && 0 != (tem = negate_expr (arg1))
7212 && TREE_CODE (tem) == INTEGER_CST
7213 && ! TREE_CONSTANT_OVERFLOW (tem))
7214 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7216 /* If we have X - Y == 0, we can convert that to X == Y and similarly
7217 for !=. Don't do this for ordered comparisons due to overflow. */
7218 else if ((code == NE_EXPR || code == EQ_EXPR)
7219 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
7220 return fold (build (code, type,
7221 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
7223 /* If we are widening one operand of an integer comparison,
7224 see if the other operand is similarly being widened. Perhaps we
7225 can do the comparison in the narrower type. */
7226 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
7227 && TREE_CODE (arg0) == NOP_EXPR
7228 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
7229 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
7230 && (TREE_TYPE (t1) == TREE_TYPE (tem)
7231 || (TREE_CODE (t1) == INTEGER_CST
7232 && int_fits_type_p (t1, TREE_TYPE (tem)))))
7233 return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
7235 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
7236 constant, we can simplify it. */
7237 else if (TREE_CODE (arg1) == INTEGER_CST
7238 && (TREE_CODE (arg0) == MIN_EXPR
7239 || TREE_CODE (arg0) == MAX_EXPR)
7240 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7241 return optimize_minmax_comparison (t);
7243 /* If we are comparing an ABS_EXPR with a constant, we can
7244 convert all the cases into explicit comparisons, but they may
7245 well not be faster than doing the ABS and one comparison.
7246 But ABS (X) <= C is a range comparison, which becomes a subtraction
7247 and a comparison, and is probably faster. */
7248 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7249 && TREE_CODE (arg0) == ABS_EXPR
7250 && ! TREE_SIDE_EFFECTS (arg0)
7251 && (0 != (tem = negate_expr (arg1)))
7252 && TREE_CODE (tem) == INTEGER_CST
7253 && ! TREE_CONSTANT_OVERFLOW (tem))
7254 return fold (build (TRUTH_ANDIF_EXPR, type,
7255 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
7256 build (LE_EXPR, type,
7257 TREE_OPERAND (arg0, 0), arg1)));
7259 /* If this is an EQ or NE comparison with zero and ARG0 is
7260 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
7261 two operations, but the latter can be done in one less insn
7262 on machines that have only two-operand insns or on which a
7263 constant cannot be the first operand. */
7264 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
7265 && TREE_CODE (arg0) == BIT_AND_EXPR)
7267 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
7268 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
7270 fold (build (code, type,
7271 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7273 TREE_TYPE (TREE_OPERAND (arg0, 0)),
7274 TREE_OPERAND (arg0, 1),
7275 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
7276 convert (TREE_TYPE (arg0),
7279 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
7280 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
7282 fold (build (code, type,
7283 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7285 TREE_TYPE (TREE_OPERAND (arg0, 1)),
7286 TREE_OPERAND (arg0, 0),
7287 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
7288 convert (TREE_TYPE (arg0),
7293 /* If this is an NE or EQ comparison of zero against the result of a
7294 signed MOD operation whose second operand is a power of 2, make
7295 the MOD operation unsigned since it is simpler and equivalent. */
7296 if ((code == NE_EXPR || code == EQ_EXPR)
7297 && integer_zerop (arg1)
7298 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
7299 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
7300 || TREE_CODE (arg0) == CEIL_MOD_EXPR
7301 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
7302 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
7303 && integer_pow2p (TREE_OPERAND (arg0, 1)))
7305 tree newtype = (*lang_hooks.types.unsigned_type) (TREE_TYPE (arg0));
7306 tree newmod = build (TREE_CODE (arg0), newtype,
7307 convert (newtype, TREE_OPERAND (arg0, 0)),
7308 convert (newtype, TREE_OPERAND (arg0, 1)));
7310 return build (code, type, newmod, convert (newtype, arg1));
7313 /* If this is an NE comparison of zero with an AND of one, remove the
7314 comparison since the AND will give the correct value. */
7315 if (code == NE_EXPR && integer_zerop (arg1)
7316 && TREE_CODE (arg0) == BIT_AND_EXPR
7317 && integer_onep (TREE_OPERAND (arg0, 1)))
7318 return convert (type, arg0);
7320 /* If we have (A & C) == C where C is a power of 2, convert this into
7321 (A & C) != 0. Similarly for NE_EXPR. */
7322 if ((code == EQ_EXPR || code == NE_EXPR)
7323 && TREE_CODE (arg0) == BIT_AND_EXPR
7324 && integer_pow2p (TREE_OPERAND (arg0, 1))
7325 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
7326 return fold (build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
7327 arg0, integer_zero_node));
7329 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
7330 2, then fold the expression into shifts and logical operations. */
7331 tem = fold_single_bit_test (code, arg0, arg1, type);
7335 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
7336 Similarly for NE_EXPR. */
7337 if ((code == EQ_EXPR || code == NE_EXPR)
7338 && TREE_CODE (arg0) == BIT_AND_EXPR
7339 && TREE_CODE (arg1) == INTEGER_CST
7340 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7342 tree dandnotc = fold (build (BIT_ANDTC_EXPR, TREE_TYPE (arg0),
7343 arg1, TREE_OPERAND (arg0, 1)));
7344 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
7345 if (!integer_zerop (dandnotc))
7346 return omit_one_operand (type, rslt, arg0);
7349 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
7350 Similarly for NE_EXPR. */
7351 if ((code == EQ_EXPR || code == NE_EXPR)
7352 && TREE_CODE (arg0) == BIT_IOR_EXPR
7353 && TREE_CODE (arg1) == INTEGER_CST
7354 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7356 tree candnotd = fold (build (BIT_ANDTC_EXPR, TREE_TYPE (arg0),
7357 TREE_OPERAND (arg0, 1), arg1));
7358 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
7359 if (!integer_zerop (candnotd))
7360 return omit_one_operand (type, rslt, arg0);
7363 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
7364 and similarly for >= into !=. */
7365 if ((code == LT_EXPR || code == GE_EXPR)
7366 && TREE_UNSIGNED (TREE_TYPE (arg0))
7367 && TREE_CODE (arg1) == LSHIFT_EXPR
7368 && integer_onep (TREE_OPERAND (arg1, 0)))
7369 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7370 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7371 TREE_OPERAND (arg1, 1)),
7372 convert (TREE_TYPE (arg0), integer_zero_node));
7374 else if ((code == LT_EXPR || code == GE_EXPR)
7375 && TREE_UNSIGNED (TREE_TYPE (arg0))
7376 && (TREE_CODE (arg1) == NOP_EXPR
7377 || TREE_CODE (arg1) == CONVERT_EXPR)
7378 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
7379 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
7381 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7382 convert (TREE_TYPE (arg0),
7383 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7384 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
7385 convert (TREE_TYPE (arg0), integer_zero_node));
7387 /* Simplify comparison of something with itself. (For IEEE
7388 floating-point, we can only do some of these simplifications.) */
7389 if (operand_equal_p (arg0, arg1, 0))
7396 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
7397 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7398 return constant_boolean_node (1, type);
7402 TREE_SET_CODE (t, code);
7406 /* For NE, we can only do this simplification if integer
7407 or we don't honor IEEE floating point NaNs. */
7408 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
7409 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7411 /* ... fall through ... */
7414 return constant_boolean_node (0, type);
7420 /* If we are comparing an expression that just has comparisons
7421 of two integer values, arithmetic expressions of those comparisons,
7422 and constants, we can simplify it. There are only three cases
7423 to check: the two values can either be equal, the first can be
7424 greater, or the second can be greater. Fold the expression for
7425 those three values. Since each value must be 0 or 1, we have
7426 eight possibilities, each of which corresponds to the constant 0
7427 or 1 or one of the six possible comparisons.
7429 This handles common cases like (a > b) == 0 but also handles
7430 expressions like ((x > y) - (y > x)) > 0, which supposedly
7431 occur in macroized code. */
7433 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
7435 tree cval1 = 0, cval2 = 0;
7438 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
7439 /* Don't handle degenerate cases here; they should already
7440 have been handled anyway. */
7441 && cval1 != 0 && cval2 != 0
7442 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
7443 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
7444 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
7445 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
7446 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
7447 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
7448 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
7450 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
7451 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
7453 /* We can't just pass T to eval_subst in case cval1 or cval2
7454 was the same as ARG1. */
7457 = fold (build (code, type,
7458 eval_subst (arg0, cval1, maxval, cval2, minval),
7461 = fold (build (code, type,
7462 eval_subst (arg0, cval1, maxval, cval2, maxval),
7465 = fold (build (code, type,
7466 eval_subst (arg0, cval1, minval, cval2, maxval),
7469 /* All three of these results should be 0 or 1. Confirm they
7470 are. Then use those values to select the proper code
7473 if ((integer_zerop (high_result)
7474 || integer_onep (high_result))
7475 && (integer_zerop (equal_result)
7476 || integer_onep (equal_result))
7477 && (integer_zerop (low_result)
7478 || integer_onep (low_result)))
7480 /* Make a 3-bit mask with the high-order bit being the
7481 value for `>', the next for '=', and the low for '<'. */
7482 switch ((integer_onep (high_result) * 4)
7483 + (integer_onep (equal_result) * 2)
7484 + integer_onep (low_result))
7488 return omit_one_operand (type, integer_zero_node, arg0);
7509 return omit_one_operand (type, integer_one_node, arg0);
7512 t = build (code, type, cval1, cval2);
7514 return save_expr (t);
7521 /* If this is a comparison of a field, we may be able to simplify it. */
7522 if (((TREE_CODE (arg0) == COMPONENT_REF
7523 && (*lang_hooks.can_use_bit_fields_p) ())
7524 || TREE_CODE (arg0) == BIT_FIELD_REF)
7525 && (code == EQ_EXPR || code == NE_EXPR)
7526 /* Handle the constant case even without -O
7527 to make sure the warnings are given. */
7528 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
7530 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
7534 /* If this is a comparison of complex values and either or both sides
7535 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
7536 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
7537 This may prevent needless evaluations. */
7538 if ((code == EQ_EXPR || code == NE_EXPR)
7539 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
7540 && (TREE_CODE (arg0) == COMPLEX_EXPR
7541 || TREE_CODE (arg1) == COMPLEX_EXPR
7542 || TREE_CODE (arg0) == COMPLEX_CST
7543 || TREE_CODE (arg1) == COMPLEX_CST))
7545 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
7546 tree real0, imag0, real1, imag1;
7548 arg0 = save_expr (arg0);
7549 arg1 = save_expr (arg1);
7550 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
7551 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
7552 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
7553 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
7555 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
7558 fold (build (code, type, real0, real1)),
7559 fold (build (code, type, imag0, imag1))));
7562 /* Optimize comparisons of strlen vs zero to a compare of the
7563 first character of the string vs zero. To wit,
7564 strlen(ptr) == 0 => *ptr == 0
7565 strlen(ptr) != 0 => *ptr != 0
7566 Other cases should reduce to one of these two (or a constant)
7567 due to the return value of strlen being unsigned. */
7568 if ((code == EQ_EXPR || code == NE_EXPR)
7569 && integer_zerop (arg1)
7570 && TREE_CODE (arg0) == CALL_EXPR
7571 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ADDR_EXPR)
7573 tree fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7576 if (TREE_CODE (fndecl) == FUNCTION_DECL
7577 && DECL_BUILT_IN (fndecl)
7578 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
7579 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
7580 && (arglist = TREE_OPERAND (arg0, 1))
7581 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
7582 && ! TREE_CHAIN (arglist))
7583 return fold (build (code, type,
7584 build1 (INDIRECT_REF, char_type_node,
7585 TREE_VALUE(arglist)),
7586 integer_zero_node));
7589 /* From here on, the only cases we handle are when the result is
7590 known to be a constant.
7592 To compute GT, swap the arguments and do LT.
7593 To compute GE, do LT and invert the result.
7594 To compute LE, swap the arguments, do LT and invert the result.
7595 To compute NE, do EQ and invert the result.
7597 Therefore, the code below must handle only EQ and LT. */
7599 if (code == LE_EXPR || code == GT_EXPR)
7601 tem = arg0, arg0 = arg1, arg1 = tem;
7602 code = swap_tree_comparison (code);
7605 /* Note that it is safe to invert for real values here because we
7606 will check below in the one case that it matters. */
7610 if (code == NE_EXPR || code == GE_EXPR)
7613 code = invert_tree_comparison (code);
7616 /* Compute a result for LT or EQ if args permit;
7617 otherwise return T. */
7618 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
7620 if (code == EQ_EXPR)
7621 t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0);
7623 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
7624 ? INT_CST_LT_UNSIGNED (arg0, arg1)
7625 : INT_CST_LT (arg0, arg1)),
7629 #if 0 /* This is no longer useful, but breaks some real code. */
7630 /* Assume a nonexplicit constant cannot equal an explicit one,
7631 since such code would be undefined anyway.
7632 Exception: on sysvr4, using #pragma weak,
7633 a label can come out as 0. */
7634 else if (TREE_CODE (arg1) == INTEGER_CST
7635 && !integer_zerop (arg1)
7636 && TREE_CONSTANT (arg0)
7637 && TREE_CODE (arg0) == ADDR_EXPR
7639 t1 = build_int_2 (0, 0);
7641 /* Two real constants can be compared explicitly. */
7642 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
7644 /* If either operand is a NaN, the result is false with two
7645 exceptions: First, an NE_EXPR is true on NaNs, but that case
7646 is already handled correctly since we will be inverting the
7647 result for NE_EXPR. Second, if we had inverted a LE_EXPR
7648 or a GE_EXPR into a LT_EXPR, we must return true so that it
7649 will be inverted into false. */
7651 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
7652 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
7653 t1 = build_int_2 (invert && code == LT_EXPR, 0);
7655 else if (code == EQ_EXPR)
7656 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
7657 TREE_REAL_CST (arg1)),
7660 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
7661 TREE_REAL_CST (arg1)),
7665 if (t1 == NULL_TREE)
7669 TREE_INT_CST_LOW (t1) ^= 1;
7671 TREE_TYPE (t1) = type;
7672 if (TREE_CODE (type) == BOOLEAN_TYPE)
7673 return (*lang_hooks.truthvalue_conversion) (t1);
7677 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
7678 so all simple results must be passed through pedantic_non_lvalue. */
7679 if (TREE_CODE (arg0) == INTEGER_CST)
7680 return pedantic_non_lvalue
7681 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
7682 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
7683 return pedantic_omit_one_operand (type, arg1, arg0);
7685 /* If the second operand is zero, invert the comparison and swap
7686 the second and third operands. Likewise if the second operand
7687 is constant and the third is not or if the third operand is
7688 equivalent to the first operand of the comparison. */
7690 if (integer_zerop (arg1)
7691 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
7692 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
7693 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
7694 TREE_OPERAND (t, 2),
7695 TREE_OPERAND (arg0, 1))))
7697 /* See if this can be inverted. If it can't, possibly because
7698 it was a floating-point inequality comparison, don't do
7700 tem = invert_truthvalue (arg0);
7702 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7704 t = build (code, type, tem,
7705 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7707 /* arg1 should be the first argument of the new T. */
7708 arg1 = TREE_OPERAND (t, 1);
7713 /* If we have A op B ? A : C, we may be able to convert this to a
7714 simpler expression, depending on the operation and the values
7715 of B and C. Signed zeros prevent all of these transformations,
7716 for reasons given above each one. */
7718 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
7719 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
7720 arg1, TREE_OPERAND (arg0, 1))
7721 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
7723 tree arg2 = TREE_OPERAND (t, 2);
7724 enum tree_code comp_code = TREE_CODE (arg0);
7728 /* If we have A op 0 ? A : -A, consider applying the following
7731 A == 0? A : -A same as -A
7732 A != 0? A : -A same as A
7733 A >= 0? A : -A same as abs (A)
7734 A > 0? A : -A same as abs (A)
7735 A <= 0? A : -A same as -abs (A)
7736 A < 0? A : -A same as -abs (A)
7738 None of these transformations work for modes with signed
7739 zeros. If A is +/-0, the first two transformations will
7740 change the sign of the result (from +0 to -0, or vice
7741 versa). The last four will fix the sign of the result,
7742 even though the original expressions could be positive or
7743 negative, depending on the sign of A.
7745 Note that all these transformations are correct if A is
7746 NaN, since the two alternatives (A and -A) are also NaNs. */
7747 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
7748 ? real_zerop (TREE_OPERAND (arg0, 1))
7749 : integer_zerop (TREE_OPERAND (arg0, 1)))
7750 && TREE_CODE (arg2) == NEGATE_EXPR
7751 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
7759 (convert (TREE_TYPE (TREE_OPERAND (t, 1)),
7762 return pedantic_non_lvalue (convert (type, arg1));
7765 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7766 arg1 = convert ((*lang_hooks.types.signed_type)
7767 (TREE_TYPE (arg1)), arg1);
7768 return pedantic_non_lvalue
7769 (convert (type, fold (build1 (ABS_EXPR,
7770 TREE_TYPE (arg1), arg1))));
7773 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7774 arg1 = convert ((lang_hooks.types.signed_type)
7775 (TREE_TYPE (arg1)), arg1);
7776 return pedantic_non_lvalue
7777 (negate_expr (convert (type,
7778 fold (build1 (ABS_EXPR,
7785 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
7786 A == 0 ? A : 0 is always 0 unless A is -0. Note that
7787 both transformations are correct when A is NaN: A != 0
7788 is then true, and A == 0 is false. */
7790 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
7792 if (comp_code == NE_EXPR)
7793 return pedantic_non_lvalue (convert (type, arg1));
7794 else if (comp_code == EQ_EXPR)
7795 return pedantic_non_lvalue (convert (type, integer_zero_node));
7798 /* Try some transformations of A op B ? A : B.
7800 A == B? A : B same as B
7801 A != B? A : B same as A
7802 A >= B? A : B same as max (A, B)
7803 A > B? A : B same as max (B, A)
7804 A <= B? A : B same as min (A, B)
7805 A < B? A : B same as min (B, A)
7807 As above, these transformations don't work in the presence
7808 of signed zeros. For example, if A and B are zeros of
7809 opposite sign, the first two transformations will change
7810 the sign of the result. In the last four, the original
7811 expressions give different results for (A=+0, B=-0) and
7812 (A=-0, B=+0), but the transformed expressions do not.
7814 The first two transformations are correct if either A or B
7815 is a NaN. In the first transformation, the condition will
7816 be false, and B will indeed be chosen. In the case of the
7817 second transformation, the condition A != B will be true,
7818 and A will be chosen.
7820 The conversions to max() and min() are not correct if B is
7821 a number and A is not. The conditions in the original
7822 expressions will be false, so all four give B. The min()
7823 and max() versions would give a NaN instead. */
7824 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
7825 arg2, TREE_OPERAND (arg0, 0)))
7827 tree comp_op0 = TREE_OPERAND (arg0, 0);
7828 tree comp_op1 = TREE_OPERAND (arg0, 1);
7829 tree comp_type = TREE_TYPE (comp_op0);
7831 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
7832 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
7842 return pedantic_non_lvalue (convert (type, arg2));
7844 return pedantic_non_lvalue (convert (type, arg1));
7847 /* In C++ a ?: expression can be an lvalue, so put the
7848 operand which will be used if they are equal first
7849 so that we can convert this back to the
7850 corresponding COND_EXPR. */
7851 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
7852 return pedantic_non_lvalue
7853 (convert (type, fold (build (MIN_EXPR, comp_type,
7854 (comp_code == LE_EXPR
7855 ? comp_op0 : comp_op1),
7856 (comp_code == LE_EXPR
7857 ? comp_op1 : comp_op0)))));
7861 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
7862 return pedantic_non_lvalue
7863 (convert (type, fold (build (MAX_EXPR, comp_type,
7864 (comp_code == GE_EXPR
7865 ? comp_op0 : comp_op1),
7866 (comp_code == GE_EXPR
7867 ? comp_op1 : comp_op0)))));
7874 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
7875 we might still be able to simplify this. For example,
7876 if C1 is one less or one more than C2, this might have started
7877 out as a MIN or MAX and been transformed by this function.
7878 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
7880 if (INTEGRAL_TYPE_P (type)
7881 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7882 && TREE_CODE (arg2) == INTEGER_CST)
7886 /* We can replace A with C1 in this case. */
7887 arg1 = convert (type, TREE_OPERAND (arg0, 1));
7888 t = build (code, type, TREE_OPERAND (t, 0), arg1,
7889 TREE_OPERAND (t, 2));
7893 /* If C1 is C2 + 1, this is min(A, C2). */
7894 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7895 && operand_equal_p (TREE_OPERAND (arg0, 1),
7896 const_binop (PLUS_EXPR, arg2,
7897 integer_one_node, 0), 1))
7898 return pedantic_non_lvalue
7899 (fold (build (MIN_EXPR, type, arg1, arg2)));
7903 /* If C1 is C2 - 1, this is min(A, C2). */
7904 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7905 && operand_equal_p (TREE_OPERAND (arg0, 1),
7906 const_binop (MINUS_EXPR, arg2,
7907 integer_one_node, 0), 1))
7908 return pedantic_non_lvalue
7909 (fold (build (MIN_EXPR, type, arg1, arg2)));
7913 /* If C1 is C2 - 1, this is max(A, C2). */
7914 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7915 && operand_equal_p (TREE_OPERAND (arg0, 1),
7916 const_binop (MINUS_EXPR, arg2,
7917 integer_one_node, 0), 1))
7918 return pedantic_non_lvalue
7919 (fold (build (MAX_EXPR, type, arg1, arg2)));
7923 /* If C1 is C2 + 1, this is max(A, C2). */
7924 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7925 && operand_equal_p (TREE_OPERAND (arg0, 1),
7926 const_binop (PLUS_EXPR, arg2,
7927 integer_one_node, 0), 1))
7928 return pedantic_non_lvalue
7929 (fold (build (MAX_EXPR, type, arg1, arg2)));
7938 /* If the second operand is simpler than the third, swap them
7939 since that produces better jump optimization results. */
7940 if ((TREE_CONSTANT (arg1) || DECL_P (arg1)
7941 || TREE_CODE (arg1) == SAVE_EXPR)
7942 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
7943 || DECL_P (TREE_OPERAND (t, 2))
7944 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
7946 /* See if this can be inverted. If it can't, possibly because
7947 it was a floating-point inequality comparison, don't do
7949 tem = invert_truthvalue (arg0);
7951 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7953 t = build (code, type, tem,
7954 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7956 /* arg1 should be the first argument of the new T. */
7957 arg1 = TREE_OPERAND (t, 1);
7962 /* Convert A ? 1 : 0 to simply A. */
7963 if (integer_onep (TREE_OPERAND (t, 1))
7964 && integer_zerop (TREE_OPERAND (t, 2))
7965 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7966 call to fold will try to move the conversion inside
7967 a COND, which will recurse. In that case, the COND_EXPR
7968 is probably the best choice, so leave it alone. */
7969 && type == TREE_TYPE (arg0))
7970 return pedantic_non_lvalue (arg0);
7972 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
7973 over COND_EXPR in cases such as floating point comparisons. */
7974 if (integer_zerop (TREE_OPERAND (t, 1))
7975 && integer_onep (TREE_OPERAND (t, 2))
7976 && truth_value_p (TREE_CODE (arg0)))
7977 return pedantic_non_lvalue (convert (type,
7978 invert_truthvalue (arg0)));
7980 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7981 operation is simply A & 2. */
7983 if (integer_zerop (TREE_OPERAND (t, 2))
7984 && TREE_CODE (arg0) == NE_EXPR
7985 && integer_zerop (TREE_OPERAND (arg0, 1))
7986 && integer_pow2p (arg1)
7987 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
7988 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
7990 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
7992 /* Convert A ? B : 0 into A && B if A and B are truth values. */
7993 if (integer_zerop (TREE_OPERAND (t, 2))
7994 && truth_value_p (TREE_CODE (arg0))
7995 && truth_value_p (TREE_CODE (arg1)))
7996 return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR, type,
7999 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
8000 if (integer_onep (TREE_OPERAND (t, 2))
8001 && truth_value_p (TREE_CODE (arg0))
8002 && truth_value_p (TREE_CODE (arg1)))
8004 /* Only perform transformation if ARG0 is easily inverted. */
8005 tem = invert_truthvalue (arg0);
8006 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8007 return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR, type,
8014 /* When pedantic, a compound expression can be neither an lvalue
8015 nor an integer constant expression. */
8016 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
8018 /* Don't let (0, 0) be null pointer constant. */
8019 if (integer_zerop (arg1))
8020 return build1 (NOP_EXPR, type, arg1);
8021 return convert (type, arg1);
8025 return build_complex (type, arg0, arg1);
8029 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8031 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8032 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8033 TREE_OPERAND (arg0, 1));
8034 else if (TREE_CODE (arg0) == COMPLEX_CST)
8035 return TREE_REALPART (arg0);
8036 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8037 return fold (build (TREE_CODE (arg0), type,
8038 fold (build1 (REALPART_EXPR, type,
8039 TREE_OPERAND (arg0, 0))),
8040 fold (build1 (REALPART_EXPR,
8041 type, TREE_OPERAND (arg0, 1)))));
8045 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8046 return convert (type, integer_zero_node);
8047 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8048 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8049 TREE_OPERAND (arg0, 0));
8050 else if (TREE_CODE (arg0) == COMPLEX_CST)
8051 return TREE_IMAGPART (arg0);
8052 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8053 return fold (build (TREE_CODE (arg0), type,
8054 fold (build1 (IMAGPART_EXPR, type,
8055 TREE_OPERAND (arg0, 0))),
8056 fold (build1 (IMAGPART_EXPR, type,
8057 TREE_OPERAND (arg0, 1)))));
8060 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
8062 case CLEANUP_POINT_EXPR:
8063 if (! has_cleanups (arg0))
8064 return TREE_OPERAND (t, 0);
8067 enum tree_code code0 = TREE_CODE (arg0);
8068 int kind0 = TREE_CODE_CLASS (code0);
8069 tree arg00 = TREE_OPERAND (arg0, 0);
8072 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
8073 return fold (build1 (code0, type,
8074 fold (build1 (CLEANUP_POINT_EXPR,
8075 TREE_TYPE (arg00), arg00))));
8077 if (kind0 == '<' || kind0 == '2'
8078 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
8079 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
8080 || code0 == TRUTH_XOR_EXPR)
8082 arg01 = TREE_OPERAND (arg0, 1);
8084 if (TREE_CONSTANT (arg00)
8085 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
8086 && ! has_cleanups (arg00)))
8087 return fold (build (code0, type, arg00,
8088 fold (build1 (CLEANUP_POINT_EXPR,
8089 TREE_TYPE (arg01), arg01))));
8091 if (TREE_CONSTANT (arg01))
8092 return fold (build (code0, type,
8093 fold (build1 (CLEANUP_POINT_EXPR,
8094 TREE_TYPE (arg00), arg00)),
8102 /* Check for a built-in function. */
8103 if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR
8104 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr, 0), 0))
8106 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr, 0), 0)))
8108 tree tmp = fold_builtin (expr);
8116 } /* switch (code) */
8119 #ifdef ENABLE_FOLD_CHECKING
8122 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
8123 static void fold_check_failed (tree, tree);
8124 void print_fold_checksum (tree);
8126 /* When --enable-checking=fold, compute a digest of expr before
8127 and after actual fold call to see if fold did not accidentally
8128 change original expr. */
8135 unsigned char checksum_before[16], checksum_after[16];
8138 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
8139 md5_init_ctx (&ctx);
8140 fold_checksum_tree (expr, &ctx, ht);
8141 md5_finish_ctx (&ctx, checksum_before);
8144 ret = fold_1 (expr);
8146 md5_init_ctx (&ctx);
8147 fold_checksum_tree (expr, &ctx, ht);
8148 md5_finish_ctx (&ctx, checksum_after);
8151 if (memcmp (checksum_before, checksum_after, 16))
8152 fold_check_failed (expr, ret);
8158 print_fold_checksum (tree expr)
8161 unsigned char checksum[16], cnt;
8164 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
8165 md5_init_ctx (&ctx);
8166 fold_checksum_tree (expr, &ctx, ht);
8167 md5_finish_ctx (&ctx, checksum);
8169 for (cnt = 0; cnt < 16; ++cnt)
8170 fprintf (stderr, "%02x", checksum[cnt]);
8171 putc ('\n', stderr);
8175 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
8177 internal_error ("fold check: original tree changed by fold");
8181 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
8184 enum tree_code code;
8185 char buf[sizeof (struct tree_decl)];
8188 if (sizeof (struct tree_exp) + 5 * sizeof (tree)
8189 > sizeof (struct tree_decl)
8190 || sizeof (struct tree_type) > sizeof (struct tree_decl))
8194 slot = htab_find_slot (ht, expr, INSERT);
8198 code = TREE_CODE (expr);
8199 if (code == SAVE_EXPR && SAVE_EXPR_NOPLACEHOLDER (expr))
8201 /* Allow SAVE_EXPR_NOPLACEHOLDER flag to be modified. */
8202 memcpy (buf, expr, tree_size (expr));
8204 SAVE_EXPR_NOPLACEHOLDER (expr) = 0;
8206 else if (TREE_CODE_CLASS (code) == 'd' && DECL_ASSEMBLER_NAME_SET_P (expr))
8208 /* Allow DECL_ASSEMBLER_NAME to be modified. */
8209 memcpy (buf, expr, tree_size (expr));
8211 SET_DECL_ASSEMBLER_NAME (expr, NULL);
8213 else if (TREE_CODE_CLASS (code) == 't'
8214 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)))
8216 /* Allow TYPE_POINTER_TO and TYPE_REFERENCE_TO to be modified. */
8217 memcpy (buf, expr, tree_size (expr));
8219 TYPE_POINTER_TO (expr) = NULL;
8220 TYPE_REFERENCE_TO (expr) = NULL;
8222 md5_process_bytes (expr, tree_size (expr), ctx);
8223 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
8224 if (TREE_CODE_CLASS (code) != 't' && TREE_CODE_CLASS (code) != 'd')
8225 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
8226 len = TREE_CODE_LENGTH (code);
8227 switch (TREE_CODE_CLASS (code))
8233 md5_process_bytes (TREE_STRING_POINTER (expr),
8234 TREE_STRING_LENGTH (expr), ctx);
8237 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
8238 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
8241 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
8251 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
8252 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
8255 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
8256 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
8265 case SAVE_EXPR: len = 2; break;
8266 case GOTO_SUBROUTINE_EXPR: len = 0; break;
8267 case RTL_EXPR: len = 0; break;
8268 case WITH_CLEANUP_EXPR: len = 2; break;
8277 for (i = 0; i < len; ++i)
8278 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
8281 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
8282 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
8283 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
8284 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
8285 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
8286 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
8287 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
8288 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
8289 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
8290 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
8291 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
8294 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
8295 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
8296 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
8297 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
8298 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
8299 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
8300 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
8301 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
8302 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
8303 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
8312 /* Perform constant folding and related simplification of intializer
8313 expression EXPR. This behaves identically to "fold" but ignores
8314 potential run-time traps and exceptions that fold must preserve. */
8317 fold_initializer (tree expr)
8319 int saved_signaling_nans = flag_signaling_nans;
8320 int saved_trapping_math = flag_trapping_math;
8321 int saved_trapv = flag_trapv;
8324 flag_signaling_nans = 0;
8325 flag_trapping_math = 0;
8328 result = fold (expr);
8330 flag_signaling_nans = saved_signaling_nans;
8331 flag_trapping_math = saved_trapping_math;
8332 flag_trapv = saved_trapv;
8337 /* Determine if first argument is a multiple of second argument. Return 0 if
8338 it is not, or we cannot easily determined it to be.
8340 An example of the sort of thing we care about (at this point; this routine
8341 could surely be made more general, and expanded to do what the *_DIV_EXPR's
8342 fold cases do now) is discovering that
8344 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
8350 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
8352 This code also handles discovering that
8354 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
8356 is a multiple of 8 so we don't have to worry about dealing with a
8359 Note that we *look* inside a SAVE_EXPR only to determine how it was
8360 calculated; it is not safe for fold to do much of anything else with the
8361 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
8362 at run time. For example, the latter example above *cannot* be implemented
8363 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
8364 evaluation time of the original SAVE_EXPR is not necessarily the same at
8365 the time the new expression is evaluated. The only optimization of this
8366 sort that would be valid is changing
8368 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
8372 SAVE_EXPR (I) * SAVE_EXPR (J)
8374 (where the same SAVE_EXPR (J) is used in the original and the
8375 transformed version). */
8378 multiple_of_p (tree type, tree top, tree bottom)
8380 if (operand_equal_p (top, bottom, 0))
8383 if (TREE_CODE (type) != INTEGER_TYPE)
8386 switch (TREE_CODE (top))
8389 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
8390 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
8394 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
8395 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
8398 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
8402 op1 = TREE_OPERAND (top, 1);
8403 /* const_binop may not detect overflow correctly,
8404 so check for it explicitly here. */
8405 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
8406 > TREE_INT_CST_LOW (op1)
8407 && TREE_INT_CST_HIGH (op1) == 0
8408 && 0 != (t1 = convert (type,
8409 const_binop (LSHIFT_EXPR, size_one_node,
8411 && ! TREE_OVERFLOW (t1))
8412 return multiple_of_p (type, t1, bottom);
8417 /* Can't handle conversions from non-integral or wider integral type. */
8418 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
8419 || (TYPE_PRECISION (type)
8420 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
8423 /* .. fall through ... */
8426 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
8429 if (TREE_CODE (bottom) != INTEGER_CST
8430 || (TREE_UNSIGNED (type)
8431 && (tree_int_cst_sgn (top) < 0
8432 || tree_int_cst_sgn (bottom) < 0)))
8434 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
8442 /* Return true if `t' is known to be non-negative. */
8445 tree_expr_nonnegative_p (tree t)
8447 switch (TREE_CODE (t))
8457 /* These are undefined at zero. This is true even if
8458 C[LT]Z_DEFINED_VALUE_AT_ZERO is set, since what we're
8459 computing here is a user-visible property. */
8463 return tree_int_cst_sgn (t) >= 0;
8466 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
8469 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8470 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8471 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8473 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
8474 both unsigned and at least 2 bits shorter than the result. */
8475 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8476 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8477 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8479 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8480 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8481 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8482 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8484 unsigned int prec = MAX (TYPE_PRECISION (inner1),
8485 TYPE_PRECISION (inner2)) + 1;
8486 return prec < TYPE_PRECISION (TREE_TYPE (t));
8492 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8494 /* x * x for floating point x is always non-negative. */
8495 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
8497 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8498 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8501 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
8502 both unsigned and their total bits is shorter than the result. */
8503 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8504 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8505 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8507 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8508 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8509 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8510 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8511 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
8512 < TYPE_PRECISION (TREE_TYPE (t));
8516 case TRUNC_DIV_EXPR:
8518 case FLOOR_DIV_EXPR:
8519 case ROUND_DIV_EXPR:
8520 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8521 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8523 case TRUNC_MOD_EXPR:
8525 case FLOOR_MOD_EXPR:
8526 case ROUND_MOD_EXPR:
8527 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8530 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8531 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8535 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
8536 tree outer_type = TREE_TYPE (t);
8538 if (TREE_CODE (outer_type) == REAL_TYPE)
8540 if (TREE_CODE (inner_type) == REAL_TYPE)
8541 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8542 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8544 if (TREE_UNSIGNED (inner_type))
8546 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8549 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
8551 if (TREE_CODE (inner_type) == REAL_TYPE)
8552 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
8553 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8554 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
8555 && TREE_UNSIGNED (inner_type);
8561 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
8562 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
8564 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8566 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8567 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8569 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8570 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8572 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8574 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8576 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8577 case NON_LVALUE_EXPR:
8578 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8580 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8582 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
8585 if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR)
8587 tree fndecl = TREE_OPERAND (TREE_OPERAND (t, 0), 0);
8588 tree arglist = TREE_OPERAND (t, 1);
8589 if (TREE_CODE (fndecl) == FUNCTION_DECL
8590 && DECL_BUILT_IN (fndecl)
8591 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD)
8592 switch (DECL_FUNCTION_CODE (fndecl))
8595 case BUILT_IN_CABSL:
8596 case BUILT_IN_CABSF:
8601 case BUILT_IN_FABSF:
8602 case BUILT_IN_FABSL:
8604 case BUILT_IN_SQRTF:
8605 case BUILT_IN_SQRTL:
8609 case BUILT_IN_ATANF:
8610 case BUILT_IN_ATANL:
8612 case BUILT_IN_CEILF:
8613 case BUILT_IN_CEILL:
8614 case BUILT_IN_FLOOR:
8615 case BUILT_IN_FLOORF:
8616 case BUILT_IN_FLOORL:
8617 case BUILT_IN_NEARBYINT:
8618 case BUILT_IN_NEARBYINTF:
8619 case BUILT_IN_NEARBYINTL:
8620 case BUILT_IN_ROUND:
8621 case BUILT_IN_ROUNDF:
8622 case BUILT_IN_ROUNDL:
8623 case BUILT_IN_TRUNC:
8624 case BUILT_IN_TRUNCF:
8625 case BUILT_IN_TRUNCL:
8626 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
8631 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
8638 /* ... fall through ... */
8641 if (truth_value_p (TREE_CODE (t)))
8642 /* Truth values evaluate to 0 or 1, which is nonnegative. */
8646 /* We don't know sign of `t', so be conservative and return false. */
8650 /* Return true if `r' is known to be non-negative.
8651 Only handles constants at the moment. */
8654 rtl_expr_nonnegative_p (rtx r)
8656 switch (GET_CODE (r))
8659 return INTVAL (r) >= 0;
8662 if (GET_MODE (r) == VOIDmode)
8663 return CONST_DOUBLE_HIGH (r) >= 0;
8671 units = CONST_VECTOR_NUNITS (r);
8673 for (i = 0; i < units; ++i)
8675 elt = CONST_VECTOR_ELT (r, i);
8676 if (!rtl_expr_nonnegative_p (elt))
8685 /* These are always nonnegative. */
8693 #include "gt-fold-const.h"