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,
3 1999, 2000 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
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. */
55 static void encode PARAMS ((HOST_WIDE_INT *,
56 unsigned HOST_WIDE_INT,
58 static void decode PARAMS ((HOST_WIDE_INT *,
59 unsigned HOST_WIDE_INT *,
61 static tree negate_expr PARAMS ((tree));
62 static tree split_tree PARAMS ((tree, enum tree_code, tree *, tree *,
64 static tree associate_trees PARAMS ((tree, tree, enum tree_code, tree));
65 static tree int_const_binop PARAMS ((enum tree_code, tree, tree, int, int));
66 static void const_binop_1 PARAMS ((PTR));
67 static tree const_binop PARAMS ((enum tree_code, tree, tree, int));
68 static void fold_convert_1 PARAMS ((PTR));
69 static tree fold_convert PARAMS ((tree, tree));
70 static enum tree_code invert_tree_comparison PARAMS ((enum tree_code));
71 static enum tree_code swap_tree_comparison PARAMS ((enum tree_code));
72 static int truth_value_p PARAMS ((enum tree_code));
73 static int operand_equal_for_comparison_p PARAMS ((tree, tree, tree));
74 static int twoval_comparison_p PARAMS ((tree, tree *, tree *, int *));
75 static tree eval_subst PARAMS ((tree, tree, tree, tree, tree));
76 static tree omit_one_operand PARAMS ((tree, tree, tree));
77 static tree pedantic_omit_one_operand PARAMS ((tree, tree, tree));
78 static tree distribute_bit_expr PARAMS ((enum tree_code, tree, tree, tree));
79 static tree make_bit_field_ref PARAMS ((tree, tree, int, int, int));
80 static tree optimize_bit_field_compare PARAMS ((enum tree_code, tree,
82 static tree decode_field_reference PARAMS ((tree, HOST_WIDE_INT *,
84 enum machine_mode *, int *,
85 int *, tree *, tree *));
86 static int all_ones_mask_p PARAMS ((tree, int));
87 static int simple_operand_p PARAMS ((tree));
88 static tree range_binop PARAMS ((enum tree_code, tree, tree, int,
90 static tree make_range PARAMS ((tree, int *, tree *, tree *));
91 static tree build_range_check PARAMS ((tree, tree, int, tree, tree));
92 static int merge_ranges PARAMS ((int *, tree *, tree *, int, tree, tree,
94 static tree fold_range_test PARAMS ((tree));
95 static tree unextend PARAMS ((tree, int, int, tree));
96 static tree fold_truthop PARAMS ((enum tree_code, tree, tree, tree));
97 static tree optimize_minmax_comparison PARAMS ((tree));
98 static tree extract_muldiv PARAMS ((tree, tree, enum tree_code, tree));
99 static tree strip_compound_expr PARAMS ((tree, tree));
100 static int multiple_of_p PARAMS ((tree, tree, tree));
101 static tree constant_boolean_node PARAMS ((int, tree));
102 static int count_cond PARAMS ((tree, int));
105 #define BRANCH_COST 1
108 #if defined(HOST_EBCDIC)
109 /* bit 8 is significant in EBCDIC */
110 #define CHARMASK 0xff
112 #define CHARMASK 0x7f
115 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
116 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
117 and SUM1. Then this yields nonzero if overflow occurred during the
120 Overflow occurs if A and B have the same sign, but A and SUM differ in
121 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
123 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
125 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
126 We do that by representing the two-word integer in 4 words, with only
127 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
128 number. The value of the word is LOWPART + HIGHPART * BASE. */
131 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
132 #define HIGHPART(x) \
133 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
134 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
136 /* Unpack a two-word integer into 4 words.
137 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
138 WORDS points to the array of HOST_WIDE_INTs. */
141 encode (words, low, hi)
142 HOST_WIDE_INT *words;
143 unsigned HOST_WIDE_INT low;
146 words[0] = LOWPART (low);
147 words[1] = HIGHPART (low);
148 words[2] = LOWPART (hi);
149 words[3] = HIGHPART (hi);
152 /* Pack an array of 4 words into a two-word integer.
153 WORDS points to the array of words.
154 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
157 decode (words, low, hi)
158 HOST_WIDE_INT *words;
159 unsigned HOST_WIDE_INT *low;
162 *low = words[0] + words[1] * BASE;
163 *hi = words[2] + words[3] * BASE;
166 /* Make the integer constant T valid for its type by setting to 0 or 1 all
167 the bits in the constant that don't belong in the type.
169 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
170 nonzero, a signed overflow has already occurred in calculating T, so
173 Make the real constant T valid for its type by calling CHECK_FLOAT_VALUE,
177 force_fit_type (t, overflow)
181 unsigned HOST_WIDE_INT low;
185 if (TREE_CODE (t) == REAL_CST)
187 #ifdef CHECK_FLOAT_VALUE
188 CHECK_FLOAT_VALUE (TYPE_MODE (TREE_TYPE (t)), TREE_REAL_CST (t),
194 else if (TREE_CODE (t) != INTEGER_CST)
197 low = TREE_INT_CST_LOW (t);
198 high = TREE_INT_CST_HIGH (t);
200 if (POINTER_TYPE_P (TREE_TYPE (t)))
203 prec = TYPE_PRECISION (TREE_TYPE (t));
205 /* First clear all bits that are beyond the type's precision. */
207 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
209 else if (prec > HOST_BITS_PER_WIDE_INT)
210 TREE_INT_CST_HIGH (t)
211 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
214 TREE_INT_CST_HIGH (t) = 0;
215 if (prec < HOST_BITS_PER_WIDE_INT)
216 TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
219 /* Unsigned types do not suffer sign extension or overflow. */
220 if (TREE_UNSIGNED (TREE_TYPE (t)))
223 /* If the value's sign bit is set, extend the sign. */
224 if (prec != 2 * HOST_BITS_PER_WIDE_INT
225 && (prec > HOST_BITS_PER_WIDE_INT
226 ? 0 != (TREE_INT_CST_HIGH (t)
228 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
229 : 0 != (TREE_INT_CST_LOW (t)
230 & ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
232 /* Value is negative:
233 set to 1 all the bits that are outside this type's precision. */
234 if (prec > HOST_BITS_PER_WIDE_INT)
235 TREE_INT_CST_HIGH (t)
236 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
239 TREE_INT_CST_HIGH (t) = -1;
240 if (prec < HOST_BITS_PER_WIDE_INT)
241 TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
245 /* Return nonzero if signed overflow occurred. */
247 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
251 /* Add two doubleword integers with doubleword result.
252 Each argument is given as two `HOST_WIDE_INT' pieces.
253 One argument is L1 and H1; the other, L2 and H2.
254 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
257 add_double (l1, h1, l2, h2, lv, hv)
258 unsigned HOST_WIDE_INT l1, l2;
259 HOST_WIDE_INT h1, h2;
260 unsigned HOST_WIDE_INT *lv;
263 unsigned HOST_WIDE_INT l;
267 h = h1 + h2 + (l < l1);
271 return OVERFLOW_SUM_SIGN (h1, h2, h);
274 /* Negate a doubleword integer with doubleword result.
275 Return nonzero if the operation overflows, assuming it's signed.
276 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
277 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
280 neg_double (l1, h1, lv, hv)
281 unsigned HOST_WIDE_INT l1;
283 unsigned HOST_WIDE_INT *lv;
290 return (*hv & h1) < 0;
300 /* Multiply two doubleword integers with doubleword result.
301 Return nonzero if the operation overflows, assuming it's signed.
302 Each argument is given as two `HOST_WIDE_INT' pieces.
303 One argument is L1 and H1; the other, L2 and H2.
304 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
307 mul_double (l1, h1, l2, h2, lv, hv)
308 unsigned HOST_WIDE_INT l1, l2;
309 HOST_WIDE_INT h1, h2;
310 unsigned HOST_WIDE_INT *lv;
313 HOST_WIDE_INT arg1[4];
314 HOST_WIDE_INT arg2[4];
315 HOST_WIDE_INT prod[4 * 2];
316 register unsigned HOST_WIDE_INT carry;
317 register int i, j, k;
318 unsigned HOST_WIDE_INT toplow, neglow;
319 HOST_WIDE_INT tophigh, neghigh;
321 encode (arg1, l1, h1);
322 encode (arg2, l2, h2);
324 bzero ((char *) prod, sizeof prod);
326 for (i = 0; i < 4; i++)
329 for (j = 0; j < 4; j++)
332 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
333 carry += arg1[i] * arg2[j];
334 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
336 prod[k] = LOWPART (carry);
337 carry = HIGHPART (carry);
342 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
344 /* Check for overflow by calculating the top half of the answer in full;
345 it should agree with the low half's sign bit. */
346 decode (prod + 4, &toplow, &tophigh);
349 neg_double (l2, h2, &neglow, &neghigh);
350 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
354 neg_double (l1, h1, &neglow, &neghigh);
355 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
357 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
360 /* Shift the doubleword integer in L1, H1 left by COUNT places
361 keeping only PREC bits of result.
362 Shift right if COUNT is negative.
363 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
364 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
367 lshift_double (l1, h1, count, prec, lv, hv, arith)
368 unsigned HOST_WIDE_INT l1;
369 HOST_WIDE_INT h1, count;
371 unsigned HOST_WIDE_INT *lv;
377 rshift_double (l1, h1, -count, prec, lv, hv, arith);
381 #ifdef SHIFT_COUNT_TRUNCATED
382 if (SHIFT_COUNT_TRUNCATED)
386 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
388 /* Shifting by the host word size is undefined according to the
389 ANSI standard, so we must handle this as a special case. */
393 else if (count >= HOST_BITS_PER_WIDE_INT)
395 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
400 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
401 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
406 /* Shift the doubleword integer in L1, H1 right by COUNT places
407 keeping only PREC bits of result. COUNT must be positive.
408 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
409 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
412 rshift_double (l1, h1, count, prec, lv, hv, arith)
413 unsigned HOST_WIDE_INT l1;
414 HOST_WIDE_INT h1, count;
415 unsigned int prec ATTRIBUTE_UNUSED;
416 unsigned HOST_WIDE_INT *lv;
420 unsigned HOST_WIDE_INT signmask;
423 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
426 #ifdef SHIFT_COUNT_TRUNCATED
427 if (SHIFT_COUNT_TRUNCATED)
431 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
433 /* Shifting by the host word size is undefined according to the
434 ANSI standard, so we must handle this as a special case. */
438 else if (count >= HOST_BITS_PER_WIDE_INT)
441 *lv = ((signmask << (2 * HOST_BITS_PER_WIDE_INT - count - 1) << 1)
442 | ((unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT)));
447 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
448 *hv = ((signmask << (HOST_BITS_PER_WIDE_INT - count))
449 | ((unsigned HOST_WIDE_INT) h1 >> count));
453 /* Rotate the doubleword integer in L1, H1 left by COUNT places
454 keeping only PREC bits of result.
455 Rotate right if COUNT is negative.
456 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
459 lrotate_double (l1, h1, count, prec, lv, hv)
460 unsigned HOST_WIDE_INT l1;
461 HOST_WIDE_INT h1, count;
463 unsigned HOST_WIDE_INT *lv;
466 unsigned HOST_WIDE_INT s1l, s2l;
467 HOST_WIDE_INT s1h, s2h;
473 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
474 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
479 /* Rotate the doubleword integer in L1, H1 left by COUNT places
480 keeping only PREC bits of result. COUNT must be positive.
481 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
484 rrotate_double (l1, h1, count, prec, lv, hv)
485 unsigned HOST_WIDE_INT l1;
486 HOST_WIDE_INT h1, count;
488 unsigned HOST_WIDE_INT *lv;
491 unsigned HOST_WIDE_INT s1l, s2l;
492 HOST_WIDE_INT s1h, s2h;
498 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
499 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
504 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
505 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
506 CODE is a tree code for a kind of division, one of
507 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
509 It controls how the quotient is rounded to a integer.
510 Return nonzero if the operation overflows.
511 UNS nonzero says do unsigned division. */
514 div_and_round_double (code, uns,
515 lnum_orig, hnum_orig, lden_orig, hden_orig,
516 lquo, hquo, lrem, hrem)
519 unsigned HOST_WIDE_INT lnum_orig; /* num == numerator == dividend */
520 HOST_WIDE_INT hnum_orig;
521 unsigned HOST_WIDE_INT lden_orig; /* den == denominator == divisor */
522 HOST_WIDE_INT hden_orig;
523 unsigned HOST_WIDE_INT *lquo, *lrem;
524 HOST_WIDE_INT *hquo, *hrem;
527 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
528 HOST_WIDE_INT den[4], quo[4];
530 unsigned HOST_WIDE_INT work;
531 unsigned HOST_WIDE_INT carry = 0;
532 unsigned HOST_WIDE_INT lnum = lnum_orig;
533 HOST_WIDE_INT hnum = hnum_orig;
534 unsigned HOST_WIDE_INT lden = lden_orig;
535 HOST_WIDE_INT hden = hden_orig;
538 if (hden == 0 && lden == 0)
539 overflow = 1, lden = 1;
541 /* calculate quotient sign and convert operands to unsigned. */
547 /* (minimum integer) / (-1) is the only overflow case. */
548 if (neg_double (lnum, hnum, &lnum, &hnum)
549 && ((HOST_WIDE_INT) lden & hden) == -1)
555 neg_double (lden, hden, &lden, &hden);
559 if (hnum == 0 && hden == 0)
560 { /* single precision */
562 /* This unsigned division rounds toward zero. */
568 { /* trivial case: dividend < divisor */
569 /* hden != 0 already checked. */
576 bzero ((char *) quo, sizeof quo);
578 bzero ((char *) num, sizeof num); /* to zero 9th element */
579 bzero ((char *) den, sizeof den);
581 encode (num, lnum, hnum);
582 encode (den, lden, hden);
584 /* Special code for when the divisor < BASE. */
585 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
587 /* hnum != 0 already checked. */
588 for (i = 4 - 1; i >= 0; i--)
590 work = num[i] + carry * BASE;
591 quo[i] = work / lden;
597 /* Full double precision division,
598 with thanks to Don Knuth's "Seminumerical Algorithms". */
599 int num_hi_sig, den_hi_sig;
600 unsigned HOST_WIDE_INT quo_est, scale;
602 /* Find the highest non-zero divisor digit. */
603 for (i = 4 - 1;; i--)
610 /* Insure that the first digit of the divisor is at least BASE/2.
611 This is required by the quotient digit estimation algorithm. */
613 scale = BASE / (den[den_hi_sig] + 1);
615 { /* scale divisor and dividend */
617 for (i = 0; i <= 4 - 1; i++)
619 work = (num[i] * scale) + carry;
620 num[i] = LOWPART (work);
621 carry = HIGHPART (work);
626 for (i = 0; i <= 4 - 1; i++)
628 work = (den[i] * scale) + carry;
629 den[i] = LOWPART (work);
630 carry = HIGHPART (work);
631 if (den[i] != 0) den_hi_sig = i;
638 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
640 /* Guess the next quotient digit, quo_est, by dividing the first
641 two remaining dividend digits by the high order quotient digit.
642 quo_est is never low and is at most 2 high. */
643 unsigned HOST_WIDE_INT tmp;
645 num_hi_sig = i + den_hi_sig + 1;
646 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
647 if (num[num_hi_sig] != den[den_hi_sig])
648 quo_est = work / den[den_hi_sig];
652 /* Refine quo_est so it's usually correct, and at most one high. */
653 tmp = work - quo_est * den[den_hi_sig];
655 && (den[den_hi_sig - 1] * quo_est
656 > (tmp * BASE + num[num_hi_sig - 2])))
659 /* Try QUO_EST as the quotient digit, by multiplying the
660 divisor by QUO_EST and subtracting from the remaining dividend.
661 Keep in mind that QUO_EST is the I - 1st digit. */
664 for (j = 0; j <= den_hi_sig; j++)
666 work = quo_est * den[j] + carry;
667 carry = HIGHPART (work);
668 work = num[i + j] - LOWPART (work);
669 num[i + j] = LOWPART (work);
670 carry += HIGHPART (work) != 0;
673 /* If quo_est was high by one, then num[i] went negative and
674 we need to correct things. */
675 if (num[num_hi_sig] < carry)
678 carry = 0; /* add divisor back in */
679 for (j = 0; j <= den_hi_sig; j++)
681 work = num[i + j] + den[j] + carry;
682 carry = HIGHPART (work);
683 num[i + j] = LOWPART (work);
686 num [num_hi_sig] += carry;
689 /* Store the quotient digit. */
694 decode (quo, lquo, hquo);
697 /* if result is negative, make it so. */
699 neg_double (*lquo, *hquo, lquo, hquo);
701 /* compute trial remainder: rem = num - (quo * den) */
702 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
703 neg_double (*lrem, *hrem, lrem, hrem);
704 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
709 case TRUNC_MOD_EXPR: /* round toward zero */
710 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
714 case FLOOR_MOD_EXPR: /* round toward negative infinity */
715 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
718 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
726 case CEIL_MOD_EXPR: /* round toward positive infinity */
727 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
729 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
737 case ROUND_MOD_EXPR: /* round to closest integer */
739 unsigned HOST_WIDE_INT labs_rem = *lrem;
740 HOST_WIDE_INT habs_rem = *hrem;
741 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
742 HOST_WIDE_INT habs_den = hden, htwice;
744 /* Get absolute values */
746 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
748 neg_double (lden, hden, &labs_den, &habs_den);
750 /* If (2 * abs (lrem) >= abs (lden)) */
751 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
752 labs_rem, habs_rem, <wice, &htwice);
754 if (((unsigned HOST_WIDE_INT) habs_den
755 < (unsigned HOST_WIDE_INT) htwice)
756 || (((unsigned HOST_WIDE_INT) habs_den
757 == (unsigned HOST_WIDE_INT) htwice)
758 && (labs_den < ltwice)))
762 add_double (*lquo, *hquo,
763 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
766 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
778 /* compute true remainder: rem = num - (quo * den) */
779 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
780 neg_double (*lrem, *hrem, lrem, hrem);
781 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
785 #ifndef REAL_ARITHMETIC
786 /* Effectively truncate a real value to represent the nearest possible value
787 in a narrower mode. The result is actually represented in the same data
788 type as the argument, but its value is usually different.
790 A trap may occur during the FP operations and it is the responsibility
791 of the calling function to have a handler established. */
794 real_value_truncate (mode, arg)
795 enum machine_mode mode;
798 return REAL_VALUE_TRUNCATE (mode, arg);
801 #if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
803 /* Check for infinity in an IEEE double precision number. */
809 /* The IEEE 64-bit double format. */
814 unsigned exponent : 11;
815 unsigned mantissa1 : 20;
820 unsigned mantissa1 : 20;
821 unsigned exponent : 11;
827 if (u.big_endian.sign == 1)
830 return (u.big_endian.exponent == 2047
831 && u.big_endian.mantissa1 == 0
832 && u.big_endian.mantissa2 == 0);
837 return (u.little_endian.exponent == 2047
838 && u.little_endian.mantissa1 == 0
839 && u.little_endian.mantissa2 == 0);
843 /* Check whether an IEEE double precision number is a NaN. */
849 /* The IEEE 64-bit double format. */
854 unsigned exponent : 11;
855 unsigned mantissa1 : 20;
860 unsigned mantissa1 : 20;
861 unsigned exponent : 11;
867 if (u.big_endian.sign == 1)
870 return (u.big_endian.exponent == 2047
871 && (u.big_endian.mantissa1 != 0
872 || u.big_endian.mantissa2 != 0));
877 return (u.little_endian.exponent == 2047
878 && (u.little_endian.mantissa1 != 0
879 || u.little_endian.mantissa2 != 0));
883 /* Check for a negative IEEE double precision number. */
889 /* The IEEE 64-bit double format. */
894 unsigned exponent : 11;
895 unsigned mantissa1 : 20;
900 unsigned mantissa1 : 20;
901 unsigned exponent : 11;
907 if (u.big_endian.sign == 1)
910 return u.big_endian.sign;
915 return u.little_endian.sign;
918 #else /* Target not IEEE */
920 /* Let's assume other float formats don't have infinity.
921 (This can be overridden by redefining REAL_VALUE_ISINF.) */
925 REAL_VALUE_TYPE x ATTRIBUTE_UNUSED;
930 /* Let's assume other float formats don't have NaNs.
931 (This can be overridden by redefining REAL_VALUE_ISNAN.) */
935 REAL_VALUE_TYPE x ATTRIBUTE_UNUSED;
940 /* Let's assume other float formats don't have minus zero.
941 (This can be overridden by redefining REAL_VALUE_NEGATIVE.) */
949 #endif /* Target not IEEE */
951 /* Try to change R into its exact multiplicative inverse in machine mode
952 MODE. Return nonzero function value if successful. */
955 exact_real_inverse (mode, r)
956 enum machine_mode mode;
965 #ifdef CHECK_FLOAT_VALUE
969 /* Usually disable if bounds checks are not reliable. */
970 if ((HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT) && !flag_pretend_float)
973 /* Set array index to the less significant bits in the unions, depending
974 on the endian-ness of the host doubles.
975 Disable if insufficient information on the data structure. */
976 #if HOST_FLOAT_FORMAT == UNKNOWN_FLOAT_FORMAT
979 #if HOST_FLOAT_FORMAT == VAX_FLOAT_FORMAT
982 #if HOST_FLOAT_FORMAT == IBM_FLOAT_FORMAT
985 #define K (2 * HOST_FLOAT_WORDS_BIG_ENDIAN)
990 if (setjmp (float_error))
992 /* Don't do the optimization if there was an arithmetic error. */
994 set_float_handler (NULL_PTR);
997 set_float_handler (float_error);
999 /* Domain check the argument. */
1004 #ifdef REAL_INFINITY
1005 if (REAL_VALUE_ISINF (x.d) || REAL_VALUE_ISNAN (x.d))
1009 /* Compute the reciprocal and check for numerical exactness.
1010 It is unnecessary to check all the significand bits to determine
1011 whether X is a power of 2. If X is not, then it is impossible for
1012 the bottom half significand of both X and 1/X to be all zero bits.
1013 Hence we ignore the data structure of the top half and examine only
1014 the low order bits of the two significands. */
1016 if (x.i[K] != 0 || x.i[K + 1] != 0 || t.i[K] != 0 || t.i[K + 1] != 0)
1019 /* Truncate to the required mode and range-check the result. */
1020 y.d = REAL_VALUE_TRUNCATE (mode, t.d);
1021 #ifdef CHECK_FLOAT_VALUE
1023 if (CHECK_FLOAT_VALUE (mode, y.d, i))
1027 /* Fail if truncation changed the value. */
1028 if (y.d != t.d || y.d == 0.0)
1031 #ifdef REAL_INFINITY
1032 if (REAL_VALUE_ISINF (y.d) || REAL_VALUE_ISNAN (y.d))
1036 /* Output the reciprocal and return success flag. */
1037 set_float_handler (NULL_PTR);
1042 /* Convert C9X hexadecimal floating point string constant S. Return
1043 real value type in mode MODE. This function uses the host computer's
1044 floating point arithmetic when there is no REAL_ARITHMETIC. */
1047 real_hex_to_f (s, mode)
1049 enum machine_mode mode;
1053 unsigned HOST_WIDE_INT low, high;
1054 int shcount, nrmcount, k;
1055 int sign, expsign, isfloat;
1056 int lost = 0;/* Nonzero low order bits shifted out and discarded. */
1057 int frexpon = 0; /* Bits after the decimal point. */
1058 int expon = 0; /* Value of exponent. */
1059 int decpt = 0; /* How many decimal points. */
1060 int gotp = 0; /* How many P's. */
1067 while (*p == ' ' || *p == '\t')
1070 /* Sign, if any, comes first. */
1078 /* The string is supposed to start with 0x or 0X . */
1082 if (*p == 'x' || *p == 'X')
1096 while ((c = *p) != '\0')
1098 if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F')
1099 || (c >= 'a' && c <= 'f'))
1102 if (k >= 'a' && k <= 'f')
1109 if ((high & 0xf0000000) == 0)
1111 high = (high << 4) + ((low >> 28) & 15);
1112 low = (low << 4) + k;
1119 /* Record nonzero lost bits. */
1132 else if (c == 'p' || c == 'P')
1136 /* Sign of exponent. */
1143 /* Value of exponent.
1144 The exponent field is a decimal integer. */
1145 while (ISDIGIT (*p))
1147 k = (*p++ & CHARMASK) - '0';
1148 expon = 10 * expon + k;
1152 /* F suffix is ambiguous in the significand part
1153 so it must appear after the decimal exponent field. */
1154 if (*p == 'f' || *p == 'F')
1162 else if (c == 'l' || c == 'L')
1171 /* Abort if last character read was not legitimate. */
1173 if ((c != '\0' && c != ' ' && c != '\n' && c != '\r') || (decpt > 1))
1176 /* There must be either one decimal point or one p. */
1177 if (decpt == 0 && gotp == 0)
1181 if (high == 0 && low == 0)
1193 /* Leave a high guard bit for carry-out. */
1194 if ((high & 0x80000000) != 0)
1197 low = (low >> 1) | (high << 31);
1202 if ((high & 0xffff8000) == 0)
1204 high = (high << 16) + ((low >> 16) & 0xffff);
1209 while ((high & 0xc0000000) == 0)
1211 high = (high << 1) + ((low >> 31) & 1);
1216 if (isfloat || GET_MODE_SIZE (mode) == UNITS_PER_WORD)
1218 /* Keep 24 bits precision, bits 0x7fffff80.
1219 Rounding bit is 0x40. */
1220 lost = lost | low | (high & 0x3f);
1224 if ((high & 0x80) || lost)
1231 /* We need real.c to do long double formats, so here default
1232 to double precision. */
1233 #if HOST_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
1235 Keep 53 bits precision, bits 0x7fffffff fffffc00.
1236 Rounding bit is low word 0x200. */
1237 lost = lost | (low & 0x1ff);
1240 if ((low & 0x400) || lost)
1242 low = (low + 0x200) & 0xfffffc00;
1249 /* Assume it's a VAX with 56-bit significand,
1250 bits 0x7fffffff ffffff80. */
1251 lost = lost | (low & 0x7f);
1254 if ((low & 0x80) || lost)
1256 low = (low + 0x40) & 0xffffff80;
1266 ip = REAL_VALUE_LDEXP (ip, 32) + (double) low;
1267 /* Apply shifts and exponent value as power of 2. */
1268 ip = REAL_VALUE_LDEXP (ip, expon - (nrmcount + frexpon));
1275 #endif /* no REAL_ARITHMETIC */
1277 /* Given T, an expression, return the negation of T. Allow for T to be
1278 null, in which case return null. */
1290 type = TREE_TYPE (t);
1291 STRIP_SIGN_NOPS (t);
1293 switch (TREE_CODE (t))
1297 if (! TREE_UNSIGNED (type)
1298 && 0 != (tem = fold (build1 (NEGATE_EXPR, type, t)))
1299 && ! TREE_OVERFLOW (tem))
1304 return convert (type, TREE_OPERAND (t, 0));
1307 /* - (A - B) -> B - A */
1308 if (! FLOAT_TYPE_P (type) || flag_fast_math)
1309 return convert (type,
1310 fold (build (MINUS_EXPR, TREE_TYPE (t),
1311 TREE_OPERAND (t, 1),
1312 TREE_OPERAND (t, 0))));
1319 return convert (type, build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1322 /* Split a tree IN into a constant, literal and variable parts that could be
1323 combined with CODE to make IN. "constant" means an expression with
1324 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1325 commutative arithmetic operation. Store the constant part into *CONP,
1326 the literal in &LITP and return the variable part. If a part isn't
1327 present, set it to null. If the tree does not decompose in this way,
1328 return the entire tree as the variable part and the other parts as null.
1330 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1331 case, we negate an operand that was subtracted. If NEGATE_P is true, we
1332 are negating all of IN.
1334 If IN is itself a literal or constant, return it as appropriate.
1336 Note that we do not guarantee that any of the three values will be the
1337 same type as IN, but they will have the same signedness and mode. */
1340 split_tree (in, code, conp, litp, negate_p)
1342 enum tree_code code;
1351 /* Strip any conversions that don't change the machine mode or signedness. */
1352 STRIP_SIGN_NOPS (in);
1354 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1356 else if (TREE_CONSTANT (in))
1359 else if (TREE_CODE (in) == code
1360 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1361 /* We can associate addition and subtraction together (even
1362 though the C standard doesn't say so) for integers because
1363 the value is not affected. For reals, the value might be
1364 affected, so we can't. */
1365 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1366 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1368 tree op0 = TREE_OPERAND (in, 0);
1369 tree op1 = TREE_OPERAND (in, 1);
1370 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1371 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1373 /* First see if either of the operands is a literal, then a constant. */
1374 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1375 *litp = op0, op0 = 0;
1376 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1377 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1379 if (op0 != 0 && TREE_CONSTANT (op0))
1380 *conp = op0, op0 = 0;
1381 else if (op1 != 0 && TREE_CONSTANT (op1))
1382 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1384 /* If we haven't dealt with either operand, this is not a case we can
1385 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1386 if (op0 != 0 && op1 != 0)
1391 var = op1, neg_var_p = neg1_p;
1393 /* Now do any needed negations. */
1394 if (neg_litp_p) *litp = negate_expr (*litp);
1395 if (neg_conp_p) *conp = negate_expr (*conp);
1396 if (neg_var_p) var = negate_expr (var);
1403 var = negate_expr (var);
1404 *conp = negate_expr (*conp);
1405 *litp = negate_expr (*litp);
1411 /* Re-associate trees split by the above function. T1 and T2 are either
1412 expressions to associate or null. Return the new expression, if any. If
1413 we build an operation, do it in TYPE and with CODE, except if CODE is a
1414 MINUS_EXPR, in which case we use PLUS_EXPR since split_tree will already
1415 have taken care of the negations. */
1418 associate_trees (t1, t2, code, type)
1420 enum tree_code code;
1428 if (code == MINUS_EXPR)
1431 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1432 try to fold this since we will have infinite recursion. But do
1433 deal with any NEGATE_EXPRs. */
1434 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1435 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1437 if (TREE_CODE (t1) == NEGATE_EXPR)
1438 return build (MINUS_EXPR, type, convert (type, t2),
1439 convert (type, TREE_OPERAND (t1, 0)));
1440 else if (TREE_CODE (t2) == NEGATE_EXPR)
1441 return build (MINUS_EXPR, type, convert (type, t1),
1442 convert (type, TREE_OPERAND (t2, 0)));
1444 return build (code, type, convert (type, t1), convert (type, t2));
1447 return fold (build (code, type, convert (type, t1), convert (type, t2)));
1450 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1451 to produce a new constant.
1453 If NOTRUNC is nonzero, do not truncate the result to fit the data type.
1454 If FORSIZE is nonzero, compute overflow for unsigned types. */
1457 int_const_binop (code, arg1, arg2, notrunc, forsize)
1458 enum tree_code code;
1459 register tree arg1, arg2;
1460 int notrunc, forsize;
1462 unsigned HOST_WIDE_INT int1l, int2l;
1463 HOST_WIDE_INT int1h, int2h;
1464 unsigned HOST_WIDE_INT low;
1466 unsigned HOST_WIDE_INT garbagel;
1467 HOST_WIDE_INT garbageh;
1469 int uns = TREE_UNSIGNED (TREE_TYPE (arg1));
1471 int no_overflow = 0;
1473 int1l = TREE_INT_CST_LOW (arg1);
1474 int1h = TREE_INT_CST_HIGH (arg1);
1475 int2l = TREE_INT_CST_LOW (arg2);
1476 int2h = TREE_INT_CST_HIGH (arg2);
1481 low = int1l | int2l, hi = int1h | int2h;
1485 low = int1l ^ int2l, hi = int1h ^ int2h;
1489 low = int1l & int2l, hi = int1h & int2h;
1492 case BIT_ANDTC_EXPR:
1493 low = int1l & ~int2l, hi = int1h & ~int2h;
1499 /* It's unclear from the C standard whether shifts can overflow.
1500 The following code ignores overflow; perhaps a C standard
1501 interpretation ruling is needed. */
1502 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (TREE_TYPE (arg1)),
1510 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (TREE_TYPE (arg1)),
1515 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1519 neg_double (int2l, int2h, &low, &hi);
1520 add_double (int1l, int1h, low, hi, &low, &hi);
1521 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1525 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1528 case TRUNC_DIV_EXPR:
1529 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1530 case EXACT_DIV_EXPR:
1531 /* This is a shortcut for a common special case. */
1532 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1533 && ! TREE_CONSTANT_OVERFLOW (arg1)
1534 && ! TREE_CONSTANT_OVERFLOW (arg2)
1535 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1537 if (code == CEIL_DIV_EXPR)
1540 low = int1l / int2l, hi = 0;
1544 /* ... fall through ... */
1546 case ROUND_DIV_EXPR:
1547 if (int2h == 0 && int2l == 1)
1549 low = int1l, hi = int1h;
1552 if (int1l == int2l && int1h == int2h
1553 && ! (int1l == 0 && int1h == 0))
1558 overflow = div_and_round_double (code, uns,
1559 int1l, int1h, int2l, int2h,
1560 &low, &hi, &garbagel, &garbageh);
1563 case TRUNC_MOD_EXPR:
1564 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1565 /* This is a shortcut for a common special case. */
1566 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1567 && ! TREE_CONSTANT_OVERFLOW (arg1)
1568 && ! TREE_CONSTANT_OVERFLOW (arg2)
1569 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1571 if (code == CEIL_MOD_EXPR)
1573 low = int1l % int2l, hi = 0;
1577 /* ... fall through ... */
1579 case ROUND_MOD_EXPR:
1580 overflow = div_and_round_double (code, uns,
1581 int1l, int1h, int2l, int2h,
1582 &garbagel, &garbageh, &low, &hi);
1588 low = (((unsigned HOST_WIDE_INT) int1h
1589 < (unsigned HOST_WIDE_INT) int2h)
1590 || (((unsigned HOST_WIDE_INT) int1h
1591 == (unsigned HOST_WIDE_INT) int2h)
1594 low = (int1h < int2h
1595 || (int1h == int2h && int1l < int2l));
1597 if (low == (code == MIN_EXPR))
1598 low = int1l, hi = int1h;
1600 low = int2l, hi = int2h;
1607 if (forsize && hi == 0 && low < 10000)
1608 return size_int_type_wide (low, TREE_TYPE (arg1));
1611 t = build_int_2 (low, hi);
1612 TREE_TYPE (t) = TREE_TYPE (arg1);
1616 = ((notrunc ? (!uns || forsize) && overflow
1617 : force_fit_type (t, (!uns || forsize) && overflow) && ! no_overflow)
1618 | TREE_OVERFLOW (arg1)
1619 | TREE_OVERFLOW (arg2));
1621 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1622 So check if force_fit_type truncated the value. */
1624 && ! TREE_OVERFLOW (t)
1625 && (TREE_INT_CST_HIGH (t) != hi
1626 || TREE_INT_CST_LOW (t) != low))
1627 TREE_OVERFLOW (t) = 1;
1629 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1630 | TREE_CONSTANT_OVERFLOW (arg1)
1631 | TREE_CONSTANT_OVERFLOW (arg2));
1635 /* Define input and output argument for const_binop_1. */
1638 enum tree_code code; /* Input: tree code for operation. */
1639 tree type; /* Input: tree type for operation. */
1640 REAL_VALUE_TYPE d1, d2; /* Input: floating point operands. */
1641 tree t; /* Output: constant for result. */
1644 /* Do the real arithmetic for const_binop while protected by a
1645 float overflow handler. */
1648 const_binop_1 (data)
1651 struct cb_args *args = (struct cb_args *) data;
1652 REAL_VALUE_TYPE value;
1654 #ifdef REAL_ARITHMETIC
1655 REAL_ARITHMETIC (value, args->code, args->d1, args->d2);
1660 value = args->d1 + args->d2;
1664 value = args->d1 - args->d2;
1668 value = args->d1 * args->d2;
1672 #ifndef REAL_INFINITY
1677 value = args->d1 / args->d2;
1681 value = MIN (args->d1, args->d2);
1685 value = MAX (args->d1, args->d2);
1691 #endif /* no REAL_ARITHMETIC */
1694 = build_real (args->type,
1695 real_value_truncate (TYPE_MODE (args->type), value));
1698 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1699 constant. We assume ARG1 and ARG2 have the same data type, or at least
1700 are the same kind of constant and the same machine mode.
1702 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1705 const_binop (code, arg1, arg2, notrunc)
1706 enum tree_code code;
1707 register tree arg1, arg2;
1713 if (TREE_CODE (arg1) == INTEGER_CST)
1714 return int_const_binop (code, arg1, arg2, notrunc, 0);
1716 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1717 if (TREE_CODE (arg1) == REAL_CST)
1723 struct cb_args args;
1725 d1 = TREE_REAL_CST (arg1);
1726 d2 = TREE_REAL_CST (arg2);
1728 /* If either operand is a NaN, just return it. Otherwise, set up
1729 for floating-point trap; we return an overflow. */
1730 if (REAL_VALUE_ISNAN (d1))
1732 else if (REAL_VALUE_ISNAN (d2))
1735 /* Setup input for const_binop_1() */
1736 args.type = TREE_TYPE (arg1);
1741 if (do_float_handler (const_binop_1, (PTR) &args))
1742 /* Receive output from const_binop_1. */
1746 /* We got an exception from const_binop_1. */
1747 t = copy_node (arg1);
1752 = (force_fit_type (t, overflow)
1753 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1754 TREE_CONSTANT_OVERFLOW (t)
1756 | TREE_CONSTANT_OVERFLOW (arg1)
1757 | TREE_CONSTANT_OVERFLOW (arg2);
1760 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1761 if (TREE_CODE (arg1) == COMPLEX_CST)
1763 register tree type = TREE_TYPE (arg1);
1764 register tree r1 = TREE_REALPART (arg1);
1765 register tree i1 = TREE_IMAGPART (arg1);
1766 register tree r2 = TREE_REALPART (arg2);
1767 register tree i2 = TREE_IMAGPART (arg2);
1773 t = build_complex (type,
1774 const_binop (PLUS_EXPR, r1, r2, notrunc),
1775 const_binop (PLUS_EXPR, i1, i2, notrunc));
1779 t = build_complex (type,
1780 const_binop (MINUS_EXPR, r1, r2, notrunc),
1781 const_binop (MINUS_EXPR, i1, i2, notrunc));
1785 t = build_complex (type,
1786 const_binop (MINUS_EXPR,
1787 const_binop (MULT_EXPR,
1789 const_binop (MULT_EXPR,
1792 const_binop (PLUS_EXPR,
1793 const_binop (MULT_EXPR,
1795 const_binop (MULT_EXPR,
1802 register tree magsquared
1803 = const_binop (PLUS_EXPR,
1804 const_binop (MULT_EXPR, r2, r2, notrunc),
1805 const_binop (MULT_EXPR, i2, i2, notrunc),
1808 t = build_complex (type,
1810 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1811 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1812 const_binop (PLUS_EXPR,
1813 const_binop (MULT_EXPR, r1, r2,
1815 const_binop (MULT_EXPR, i1, i2,
1818 magsquared, notrunc),
1820 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1821 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1822 const_binop (MINUS_EXPR,
1823 const_binop (MULT_EXPR, i1, r2,
1825 const_binop (MULT_EXPR, r1, i2,
1828 magsquared, notrunc));
1840 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1841 bits are given by NUMBER and of the sizetype represented by KIND. */
1844 size_int_wide (number, kind)
1845 HOST_WIDE_INT number;
1846 enum size_type_kind kind;
1848 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1851 /* Likewise, but the desired type is specified explicitly. */
1854 size_int_type_wide (number, type)
1855 HOST_WIDE_INT number;
1858 /* Type-size nodes already made for small sizes. */
1859 static tree size_table[2048 + 1];
1860 static int init_p = 0;
1865 ggc_add_tree_root ((tree *) size_table,
1866 sizeof size_table / sizeof (tree));
1870 /* If this is a positive number that fits in the table we use to hold
1871 cached entries, see if it is already in the table and put it there
1873 if (number >= 0 && number < (int) ARRAY_SIZE (size_table))
1875 if (size_table[number] != 0)
1876 for (t = size_table[number]; t != 0; t = TREE_CHAIN (t))
1877 if (TREE_TYPE (t) == type)
1880 t = build_int_2 (number, 0);
1881 TREE_TYPE (t) = type;
1882 TREE_CHAIN (t) = size_table[number];
1883 size_table[number] = t;
1888 t = build_int_2 (number, number < 0 ? -1 : 0);
1889 TREE_TYPE (t) = type;
1890 TREE_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (t) = force_fit_type (t, 0);
1894 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1895 is a tree code. The type of the result is taken from the operands.
1896 Both must be the same type integer type and it must be a size type.
1897 If the operands are constant, so is the result. */
1900 size_binop (code, arg0, arg1)
1901 enum tree_code code;
1904 tree type = TREE_TYPE (arg0);
1906 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1907 || type != TREE_TYPE (arg1))
1910 /* Handle the special case of two integer constants faster. */
1911 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1913 /* And some specific cases even faster than that. */
1914 if (code == PLUS_EXPR && integer_zerop (arg0))
1916 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1917 && integer_zerop (arg1))
1919 else if (code == MULT_EXPR && integer_onep (arg0))
1922 /* Handle general case of two integer constants. */
1923 return int_const_binop (code, arg0, arg1, 0, 1);
1926 if (arg0 == error_mark_node || arg1 == error_mark_node)
1927 return error_mark_node;
1929 return fold (build (code, type, arg0, arg1));
1932 /* Given two values, either both of sizetype or both of bitsizetype,
1933 compute the difference between the two values. Return the value
1934 in signed type corresponding to the type of the operands. */
1937 size_diffop (arg0, arg1)
1940 tree type = TREE_TYPE (arg0);
1943 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1944 || type != TREE_TYPE (arg1))
1947 /* If the type is already signed, just do the simple thing. */
1948 if (! TREE_UNSIGNED (type))
1949 return size_binop (MINUS_EXPR, arg0, arg1);
1951 ctype = (type == bitsizetype || type == ubitsizetype
1952 ? sbitsizetype : ssizetype);
1954 /* If either operand is not a constant, do the conversions to the signed
1955 type and subtract. The hardware will do the right thing with any
1956 overflow in the subtraction. */
1957 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1958 return size_binop (MINUS_EXPR, convert (ctype, arg0),
1959 convert (ctype, arg1));
1961 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1962 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1963 overflow) and negate (which can't either). Special-case a result
1964 of zero while we're here. */
1965 if (tree_int_cst_equal (arg0, arg1))
1966 return convert (ctype, integer_zero_node);
1967 else if (tree_int_cst_lt (arg1, arg0))
1968 return convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1970 return size_binop (MINUS_EXPR, convert (ctype, integer_zero_node),
1971 convert (ctype, size_binop (MINUS_EXPR, arg1, arg0)));
1974 /* This structure is used to communicate arguments to fold_convert_1. */
1977 tree arg1; /* Input: value to convert. */
1978 tree type; /* Input: type to convert value to. */
1979 tree t; /* Ouput: result of conversion. */
1982 /* Function to convert floating-point constants, protected by floating
1983 point exception handler. */
1986 fold_convert_1 (data)
1989 struct fc_args *args = (struct fc_args *) data;
1991 args->t = build_real (args->type,
1992 real_value_truncate (TYPE_MODE (args->type),
1993 TREE_REAL_CST (args->arg1)));
1996 /* Given T, a tree representing type conversion of ARG1, a constant,
1997 return a constant tree representing the result of conversion. */
2000 fold_convert (t, arg1)
2004 register tree type = TREE_TYPE (t);
2007 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
2009 if (TREE_CODE (arg1) == INTEGER_CST)
2011 /* If we would build a constant wider than GCC supports,
2012 leave the conversion unfolded. */
2013 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
2016 /* If we are trying to make a sizetype for a small integer, use
2017 size_int to pick up cached types to reduce duplicate nodes. */
2018 if (TREE_CODE (type) == INTEGER_CST && TYPE_IS_SIZETYPE (type)
2019 && compare_tree_int (arg1, 10000) < 0)
2020 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
2022 /* Given an integer constant, make new constant with new type,
2023 appropriately sign-extended or truncated. */
2024 t = build_int_2 (TREE_INT_CST_LOW (arg1),
2025 TREE_INT_CST_HIGH (arg1));
2026 TREE_TYPE (t) = type;
2027 /* Indicate an overflow if (1) ARG1 already overflowed,
2028 or (2) force_fit_type indicates an overflow.
2029 Tell force_fit_type that an overflow has already occurred
2030 if ARG1 is a too-large unsigned value and T is signed.
2031 But don't indicate an overflow if converting a pointer. */
2033 = ((force_fit_type (t,
2034 (TREE_INT_CST_HIGH (arg1) < 0
2035 && (TREE_UNSIGNED (type)
2036 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
2037 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
2038 || TREE_OVERFLOW (arg1));
2039 TREE_CONSTANT_OVERFLOW (t)
2040 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2042 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2043 else if (TREE_CODE (arg1) == REAL_CST)
2045 /* Don't initialize these, use assignments.
2046 Initialized local aggregates don't work on old compilers. */
2050 tree type1 = TREE_TYPE (arg1);
2053 x = TREE_REAL_CST (arg1);
2054 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
2056 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
2057 if (!no_upper_bound)
2058 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
2060 /* See if X will be in range after truncation towards 0.
2061 To compensate for truncation, move the bounds away from 0,
2062 but reject if X exactly equals the adjusted bounds. */
2063 #ifdef REAL_ARITHMETIC
2064 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
2065 if (!no_upper_bound)
2066 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
2069 if (!no_upper_bound)
2072 /* If X is a NaN, use zero instead and show we have an overflow.
2073 Otherwise, range check. */
2074 if (REAL_VALUE_ISNAN (x))
2075 overflow = 1, x = dconst0;
2076 else if (! (REAL_VALUES_LESS (l, x)
2078 && REAL_VALUES_LESS (x, u)))
2081 #ifndef REAL_ARITHMETIC
2083 HOST_WIDE_INT low, high;
2084 HOST_WIDE_INT half_word
2085 = (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2);
2090 high = (HOST_WIDE_INT) (x / half_word / half_word);
2091 x -= (REAL_VALUE_TYPE) high * half_word * half_word;
2092 if (x >= (REAL_VALUE_TYPE) half_word * half_word / 2)
2094 low = x - (REAL_VALUE_TYPE) half_word * half_word / 2;
2095 low |= (HOST_WIDE_INT) -1 << (HOST_BITS_PER_WIDE_INT - 1);
2098 low = (HOST_WIDE_INT) x;
2099 if (TREE_REAL_CST (arg1) < 0)
2100 neg_double (low, high, &low, &high);
2101 t = build_int_2 (low, high);
2105 HOST_WIDE_INT low, high;
2106 REAL_VALUE_TO_INT (&low, &high, x);
2107 t = build_int_2 (low, high);
2110 TREE_TYPE (t) = type;
2112 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
2113 TREE_CONSTANT_OVERFLOW (t)
2114 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2116 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2117 TREE_TYPE (t) = type;
2119 else if (TREE_CODE (type) == REAL_TYPE)
2121 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2122 if (TREE_CODE (arg1) == INTEGER_CST)
2123 return build_real_from_int_cst (type, arg1);
2124 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2125 if (TREE_CODE (arg1) == REAL_CST)
2127 struct fc_args args;
2129 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
2132 TREE_TYPE (arg1) = type;
2136 /* Setup input for fold_convert_1() */
2140 if (do_float_handler (fold_convert_1, (PTR) &args))
2142 /* Receive output from fold_convert_1() */
2147 /* We got an exception from fold_convert_1() */
2149 t = copy_node (arg1);
2153 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
2154 TREE_CONSTANT_OVERFLOW (t)
2155 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2159 TREE_CONSTANT (t) = 1;
2163 /* Return an expr equal to X but certainly not valid as an lvalue. */
2171 /* These things are certainly not lvalues. */
2172 if (TREE_CODE (x) == NON_LVALUE_EXPR
2173 || TREE_CODE (x) == INTEGER_CST
2174 || TREE_CODE (x) == REAL_CST
2175 || TREE_CODE (x) == STRING_CST
2176 || TREE_CODE (x) == ADDR_EXPR)
2179 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2180 TREE_CONSTANT (result) = TREE_CONSTANT (x);
2184 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2185 Zero means allow extended lvalues. */
2187 int pedantic_lvalues;
2189 /* When pedantic, return an expr equal to X but certainly not valid as a
2190 pedantic lvalue. Otherwise, return X. */
2193 pedantic_non_lvalue (x)
2196 if (pedantic_lvalues)
2197 return non_lvalue (x);
2202 /* Given a tree comparison code, return the code that is the logical inverse
2203 of the given code. It is not safe to do this for floating-point
2204 comparisons, except for NE_EXPR and EQ_EXPR. */
2206 static enum tree_code
2207 invert_tree_comparison (code)
2208 enum tree_code code;
2229 /* Similar, but return the comparison that results if the operands are
2230 swapped. This is safe for floating-point. */
2232 static enum tree_code
2233 swap_tree_comparison (code)
2234 enum tree_code code;
2254 /* Return nonzero if CODE is a tree code that represents a truth value. */
2257 truth_value_p (code)
2258 enum tree_code code;
2260 return (TREE_CODE_CLASS (code) == '<'
2261 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2262 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2263 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2266 /* Return nonzero if two operands are necessarily equal.
2267 If ONLY_CONST is non-zero, only return non-zero for constants.
2268 This function tests whether the operands are indistinguishable;
2269 it does not test whether they are equal using C's == operation.
2270 The distinction is important for IEEE floating point, because
2271 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2272 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
2275 operand_equal_p (arg0, arg1, only_const)
2279 /* If both types don't have the same signedness, then we can't consider
2280 them equal. We must check this before the STRIP_NOPS calls
2281 because they may change the signedness of the arguments. */
2282 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
2288 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2289 /* This is needed for conversions and for COMPONENT_REF.
2290 Might as well play it safe and always test this. */
2291 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2292 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2293 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2296 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2297 We don't care about side effects in that case because the SAVE_EXPR
2298 takes care of that for us. In all other cases, two expressions are
2299 equal if they have no side effects. If we have two identical
2300 expressions with side effects that should be treated the same due
2301 to the only side effects being identical SAVE_EXPR's, that will
2302 be detected in the recursive calls below. */
2303 if (arg0 == arg1 && ! only_const
2304 && (TREE_CODE (arg0) == SAVE_EXPR
2305 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2308 /* Next handle constant cases, those for which we can return 1 even
2309 if ONLY_CONST is set. */
2310 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2311 switch (TREE_CODE (arg0))
2314 return (! TREE_CONSTANT_OVERFLOW (arg0)
2315 && ! TREE_CONSTANT_OVERFLOW (arg1)
2316 && tree_int_cst_equal (arg0, arg1));
2319 return (! TREE_CONSTANT_OVERFLOW (arg0)
2320 && ! TREE_CONSTANT_OVERFLOW (arg1)
2321 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2322 TREE_REAL_CST (arg1)));
2325 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2327 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2331 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2332 && ! memcmp (TREE_STRING_POINTER (arg0),
2333 TREE_STRING_POINTER (arg1),
2334 TREE_STRING_LENGTH (arg0)));
2337 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2346 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2349 /* Two conversions are equal only if signedness and modes match. */
2350 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2351 && (TREE_UNSIGNED (TREE_TYPE (arg0))
2352 != TREE_UNSIGNED (TREE_TYPE (arg1))))
2355 return operand_equal_p (TREE_OPERAND (arg0, 0),
2356 TREE_OPERAND (arg1, 0), 0);
2360 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
2361 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
2365 /* For commutative ops, allow the other order. */
2366 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
2367 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
2368 || TREE_CODE (arg0) == BIT_IOR_EXPR
2369 || TREE_CODE (arg0) == BIT_XOR_EXPR
2370 || TREE_CODE (arg0) == BIT_AND_EXPR
2371 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
2372 && operand_equal_p (TREE_OPERAND (arg0, 0),
2373 TREE_OPERAND (arg1, 1), 0)
2374 && operand_equal_p (TREE_OPERAND (arg0, 1),
2375 TREE_OPERAND (arg1, 0), 0));
2378 /* If either of the pointer (or reference) expressions we are dereferencing
2379 contain a side effect, these cannot be equal. */
2380 if (TREE_SIDE_EFFECTS (arg0)
2381 || TREE_SIDE_EFFECTS (arg1))
2384 switch (TREE_CODE (arg0))
2387 return operand_equal_p (TREE_OPERAND (arg0, 0),
2388 TREE_OPERAND (arg1, 0), 0);
2392 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2393 TREE_OPERAND (arg1, 0), 0)
2394 && operand_equal_p (TREE_OPERAND (arg0, 1),
2395 TREE_OPERAND (arg1, 1), 0));
2398 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2399 TREE_OPERAND (arg1, 0), 0)
2400 && operand_equal_p (TREE_OPERAND (arg0, 1),
2401 TREE_OPERAND (arg1, 1), 0)
2402 && operand_equal_p (TREE_OPERAND (arg0, 2),
2403 TREE_OPERAND (arg1, 2), 0));
2409 if (TREE_CODE (arg0) == RTL_EXPR)
2410 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2418 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2419 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2421 When in doubt, return 0. */
2424 operand_equal_for_comparison_p (arg0, arg1, other)
2428 int unsignedp1, unsignedpo;
2429 tree primarg0, primarg1, primother;
2430 unsigned int correct_width;
2432 if (operand_equal_p (arg0, arg1, 0))
2435 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2436 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2439 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2440 and see if the inner values are the same. This removes any
2441 signedness comparison, which doesn't matter here. */
2442 primarg0 = arg0, primarg1 = arg1;
2443 STRIP_NOPS (primarg0);
2444 STRIP_NOPS (primarg1);
2445 if (operand_equal_p (primarg0, primarg1, 0))
2448 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2449 actual comparison operand, ARG0.
2451 First throw away any conversions to wider types
2452 already present in the operands. */
2454 primarg1 = get_narrower (arg1, &unsignedp1);
2455 primother = get_narrower (other, &unsignedpo);
2457 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2458 if (unsignedp1 == unsignedpo
2459 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2460 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2462 tree type = TREE_TYPE (arg0);
2464 /* Make sure shorter operand is extended the right way
2465 to match the longer operand. */
2466 primarg1 = convert (signed_or_unsigned_type (unsignedp1,
2467 TREE_TYPE (primarg1)),
2470 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2477 /* See if ARG is an expression that is either a comparison or is performing
2478 arithmetic on comparisons. The comparisons must only be comparing
2479 two different values, which will be stored in *CVAL1 and *CVAL2; if
2480 they are non-zero it means that some operands have already been found.
2481 No variables may be used anywhere else in the expression except in the
2482 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2483 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2485 If this is true, return 1. Otherwise, return zero. */
2488 twoval_comparison_p (arg, cval1, cval2, save_p)
2490 tree *cval1, *cval2;
2493 enum tree_code code = TREE_CODE (arg);
2494 char class = TREE_CODE_CLASS (code);
2496 /* We can handle some of the 'e' cases here. */
2497 if (class == 'e' && code == TRUTH_NOT_EXPR)
2499 else if (class == 'e'
2500 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2501 || code == COMPOUND_EXPR))
2504 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2505 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2507 /* If we've already found a CVAL1 or CVAL2, this expression is
2508 two complex to handle. */
2509 if (*cval1 || *cval2)
2519 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2522 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2523 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2524 cval1, cval2, save_p));
2530 if (code == COND_EXPR)
2531 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2532 cval1, cval2, save_p)
2533 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2534 cval1, cval2, save_p)
2535 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2536 cval1, cval2, save_p));
2540 /* First see if we can handle the first operand, then the second. For
2541 the second operand, we know *CVAL1 can't be zero. It must be that
2542 one side of the comparison is each of the values; test for the
2543 case where this isn't true by failing if the two operands
2546 if (operand_equal_p (TREE_OPERAND (arg, 0),
2547 TREE_OPERAND (arg, 1), 0))
2551 *cval1 = TREE_OPERAND (arg, 0);
2552 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2554 else if (*cval2 == 0)
2555 *cval2 = TREE_OPERAND (arg, 0);
2556 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2561 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2563 else if (*cval2 == 0)
2564 *cval2 = TREE_OPERAND (arg, 1);
2565 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2577 /* ARG is a tree that is known to contain just arithmetic operations and
2578 comparisons. Evaluate the operations in the tree substituting NEW0 for
2579 any occurrence of OLD0 as an operand of a comparison and likewise for
2583 eval_subst (arg, old0, new0, old1, new1)
2585 tree old0, new0, old1, new1;
2587 tree type = TREE_TYPE (arg);
2588 enum tree_code code = TREE_CODE (arg);
2589 char class = TREE_CODE_CLASS (code);
2591 /* We can handle some of the 'e' cases here. */
2592 if (class == 'e' && code == TRUTH_NOT_EXPR)
2594 else if (class == 'e'
2595 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2601 return fold (build1 (code, type,
2602 eval_subst (TREE_OPERAND (arg, 0),
2603 old0, new0, old1, new1)));
2606 return fold (build (code, type,
2607 eval_subst (TREE_OPERAND (arg, 0),
2608 old0, new0, old1, new1),
2609 eval_subst (TREE_OPERAND (arg, 1),
2610 old0, new0, old1, new1)));
2616 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2619 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2622 return fold (build (code, type,
2623 eval_subst (TREE_OPERAND (arg, 0),
2624 old0, new0, old1, new1),
2625 eval_subst (TREE_OPERAND (arg, 1),
2626 old0, new0, old1, new1),
2627 eval_subst (TREE_OPERAND (arg, 2),
2628 old0, new0, old1, new1)));
2632 /* fall through - ??? */
2636 tree arg0 = TREE_OPERAND (arg, 0);
2637 tree arg1 = TREE_OPERAND (arg, 1);
2639 /* We need to check both for exact equality and tree equality. The
2640 former will be true if the operand has a side-effect. In that
2641 case, we know the operand occurred exactly once. */
2643 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2645 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2648 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2650 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2653 return fold (build (code, type, arg0, arg1));
2661 /* Return a tree for the case when the result of an expression is RESULT
2662 converted to TYPE and OMITTED was previously an operand of the expression
2663 but is now not needed (e.g., we folded OMITTED * 0).
2665 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2666 the conversion of RESULT to TYPE. */
2669 omit_one_operand (type, result, omitted)
2670 tree type, result, omitted;
2672 tree t = convert (type, result);
2674 if (TREE_SIDE_EFFECTS (omitted))
2675 return build (COMPOUND_EXPR, type, omitted, t);
2677 return non_lvalue (t);
2680 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2683 pedantic_omit_one_operand (type, result, omitted)
2684 tree type, result, omitted;
2686 tree t = convert (type, result);
2688 if (TREE_SIDE_EFFECTS (omitted))
2689 return build (COMPOUND_EXPR, type, omitted, t);
2691 return pedantic_non_lvalue (t);
2694 /* Return a simplified tree node for the truth-negation of ARG. This
2695 never alters ARG itself. We assume that ARG is an operation that
2696 returns a truth value (0 or 1). */
2699 invert_truthvalue (arg)
2702 tree type = TREE_TYPE (arg);
2703 enum tree_code code = TREE_CODE (arg);
2705 if (code == ERROR_MARK)
2708 /* If this is a comparison, we can simply invert it, except for
2709 floating-point non-equality comparisons, in which case we just
2710 enclose a TRUTH_NOT_EXPR around what we have. */
2712 if (TREE_CODE_CLASS (code) == '<')
2714 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2715 && !flag_fast_math && code != NE_EXPR && code != EQ_EXPR)
2716 return build1 (TRUTH_NOT_EXPR, type, arg);
2718 return build (invert_tree_comparison (code), type,
2719 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2725 return convert (type, build_int_2 (integer_zerop (arg), 0));
2727 case TRUTH_AND_EXPR:
2728 return build (TRUTH_OR_EXPR, type,
2729 invert_truthvalue (TREE_OPERAND (arg, 0)),
2730 invert_truthvalue (TREE_OPERAND (arg, 1)));
2733 return build (TRUTH_AND_EXPR, type,
2734 invert_truthvalue (TREE_OPERAND (arg, 0)),
2735 invert_truthvalue (TREE_OPERAND (arg, 1)));
2737 case TRUTH_XOR_EXPR:
2738 /* Here we can invert either operand. We invert the first operand
2739 unless the second operand is a TRUTH_NOT_EXPR in which case our
2740 result is the XOR of the first operand with the inside of the
2741 negation of the second operand. */
2743 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2744 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2745 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2747 return build (TRUTH_XOR_EXPR, type,
2748 invert_truthvalue (TREE_OPERAND (arg, 0)),
2749 TREE_OPERAND (arg, 1));
2751 case TRUTH_ANDIF_EXPR:
2752 return build (TRUTH_ORIF_EXPR, type,
2753 invert_truthvalue (TREE_OPERAND (arg, 0)),
2754 invert_truthvalue (TREE_OPERAND (arg, 1)));
2756 case TRUTH_ORIF_EXPR:
2757 return build (TRUTH_ANDIF_EXPR, type,
2758 invert_truthvalue (TREE_OPERAND (arg, 0)),
2759 invert_truthvalue (TREE_OPERAND (arg, 1)));
2761 case TRUTH_NOT_EXPR:
2762 return TREE_OPERAND (arg, 0);
2765 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2766 invert_truthvalue (TREE_OPERAND (arg, 1)),
2767 invert_truthvalue (TREE_OPERAND (arg, 2)));
2770 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2771 invert_truthvalue (TREE_OPERAND (arg, 1)));
2773 case WITH_RECORD_EXPR:
2774 return build (WITH_RECORD_EXPR, type,
2775 invert_truthvalue (TREE_OPERAND (arg, 0)),
2776 TREE_OPERAND (arg, 1));
2778 case NON_LVALUE_EXPR:
2779 return invert_truthvalue (TREE_OPERAND (arg, 0));
2784 return build1 (TREE_CODE (arg), type,
2785 invert_truthvalue (TREE_OPERAND (arg, 0)));
2788 if (!integer_onep (TREE_OPERAND (arg, 1)))
2790 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2793 return build1 (TRUTH_NOT_EXPR, type, arg);
2795 case CLEANUP_POINT_EXPR:
2796 return build1 (CLEANUP_POINT_EXPR, type,
2797 invert_truthvalue (TREE_OPERAND (arg, 0)));
2802 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2804 return build1 (TRUTH_NOT_EXPR, type, arg);
2807 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2808 operands are another bit-wise operation with a common input. If so,
2809 distribute the bit operations to save an operation and possibly two if
2810 constants are involved. For example, convert
2811 (A | B) & (A | C) into A | (B & C)
2812 Further simplification will occur if B and C are constants.
2814 If this optimization cannot be done, 0 will be returned. */
2817 distribute_bit_expr (code, type, arg0, arg1)
2818 enum tree_code code;
2825 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2826 || TREE_CODE (arg0) == code
2827 || (TREE_CODE (arg0) != BIT_AND_EXPR
2828 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2831 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2833 common = TREE_OPERAND (arg0, 0);
2834 left = TREE_OPERAND (arg0, 1);
2835 right = TREE_OPERAND (arg1, 1);
2837 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2839 common = TREE_OPERAND (arg0, 0);
2840 left = TREE_OPERAND (arg0, 1);
2841 right = TREE_OPERAND (arg1, 0);
2843 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2845 common = TREE_OPERAND (arg0, 1);
2846 left = TREE_OPERAND (arg0, 0);
2847 right = TREE_OPERAND (arg1, 1);
2849 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2851 common = TREE_OPERAND (arg0, 1);
2852 left = TREE_OPERAND (arg0, 0);
2853 right = TREE_OPERAND (arg1, 0);
2858 return fold (build (TREE_CODE (arg0), type, common,
2859 fold (build (code, type, left, right))));
2862 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2863 starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */
2866 make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp)
2869 int bitsize, bitpos;
2872 tree result = build (BIT_FIELD_REF, type, inner,
2873 size_int (bitsize), bitsize_int (bitpos));
2875 TREE_UNSIGNED (result) = unsignedp;
2880 /* Optimize a bit-field compare.
2882 There are two cases: First is a compare against a constant and the
2883 second is a comparison of two items where the fields are at the same
2884 bit position relative to the start of a chunk (byte, halfword, word)
2885 large enough to contain it. In these cases we can avoid the shift
2886 implicit in bitfield extractions.
2888 For constants, we emit a compare of the shifted constant with the
2889 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2890 compared. For two fields at the same position, we do the ANDs with the
2891 similar mask and compare the result of the ANDs.
2893 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2894 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2895 are the left and right operands of the comparison, respectively.
2897 If the optimization described above can be done, we return the resulting
2898 tree. Otherwise we return zero. */
2901 optimize_bit_field_compare (code, compare_type, lhs, rhs)
2902 enum tree_code code;
2906 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2907 tree type = TREE_TYPE (lhs);
2908 tree signed_type, unsigned_type;
2909 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2910 enum machine_mode lmode, rmode, nmode;
2911 int lunsignedp, runsignedp;
2912 int lvolatilep = 0, rvolatilep = 0;
2913 unsigned int alignment;
2914 tree linner, rinner = NULL_TREE;
2918 /* Get all the information about the extractions being done. If the bit size
2919 if the same as the size of the underlying object, we aren't doing an
2920 extraction at all and so can do nothing. We also don't want to
2921 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2922 then will no longer be able to replace it. */
2923 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2924 &lunsignedp, &lvolatilep, &alignment);
2925 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2926 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2931 /* If this is not a constant, we can only do something if bit positions,
2932 sizes, and signedness are the same. */
2933 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2934 &runsignedp, &rvolatilep, &alignment);
2936 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2937 || lunsignedp != runsignedp || offset != 0
2938 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2942 /* See if we can find a mode to refer to this field. We should be able to,
2943 but fail if we can't. */
2944 nmode = get_best_mode (lbitsize, lbitpos,
2945 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2946 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2947 TYPE_ALIGN (TREE_TYPE (rinner))),
2948 word_mode, lvolatilep || rvolatilep);
2949 if (nmode == VOIDmode)
2952 /* Set signed and unsigned types of the precision of this mode for the
2954 signed_type = type_for_mode (nmode, 0);
2955 unsigned_type = type_for_mode (nmode, 1);
2957 /* Compute the bit position and size for the new reference and our offset
2958 within it. If the new reference is the same size as the original, we
2959 won't optimize anything, so return zero. */
2960 nbitsize = GET_MODE_BITSIZE (nmode);
2961 nbitpos = lbitpos & ~ (nbitsize - 1);
2963 if (nbitsize == lbitsize)
2966 if (BYTES_BIG_ENDIAN)
2967 lbitpos = nbitsize - lbitsize - lbitpos;
2969 /* Make the mask to be used against the extracted field. */
2970 mask = build_int_2 (~0, ~0);
2971 TREE_TYPE (mask) = unsigned_type;
2972 force_fit_type (mask, 0);
2973 mask = convert (unsigned_type, mask);
2974 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2975 mask = const_binop (RSHIFT_EXPR, mask,
2976 size_int (nbitsize - lbitsize - lbitpos), 0);
2979 /* If not comparing with constant, just rework the comparison
2981 return build (code, compare_type,
2982 build (BIT_AND_EXPR, unsigned_type,
2983 make_bit_field_ref (linner, unsigned_type,
2984 nbitsize, nbitpos, 1),
2986 build (BIT_AND_EXPR, unsigned_type,
2987 make_bit_field_ref (rinner, unsigned_type,
2988 nbitsize, nbitpos, 1),
2991 /* Otherwise, we are handling the constant case. See if the constant is too
2992 big for the field. Warn and return a tree of for 0 (false) if so. We do
2993 this not only for its own sake, but to avoid having to test for this
2994 error case below. If we didn't, we might generate wrong code.
2996 For unsigned fields, the constant shifted right by the field length should
2997 be all zero. For signed fields, the high-order bits should agree with
3002 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3003 convert (unsigned_type, rhs),
3004 size_int (lbitsize), 0)))
3006 warning ("comparison is always %d due to width of bitfield",
3008 return convert (compare_type,
3010 ? integer_one_node : integer_zero_node));
3015 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
3016 size_int (lbitsize - 1), 0);
3017 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3019 warning ("comparison is always %d due to width of bitfield",
3021 return convert (compare_type,
3023 ? integer_one_node : integer_zero_node));
3027 /* Single-bit compares should always be against zero. */
3028 if (lbitsize == 1 && ! integer_zerop (rhs))
3030 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3031 rhs = convert (type, integer_zero_node);
3034 /* Make a new bitfield reference, shift the constant over the
3035 appropriate number of bits and mask it with the computed mask
3036 (in case this was a signed field). If we changed it, make a new one. */
3037 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
3040 TREE_SIDE_EFFECTS (lhs) = 1;
3041 TREE_THIS_VOLATILE (lhs) = 1;
3044 rhs = fold (const_binop (BIT_AND_EXPR,
3045 const_binop (LSHIFT_EXPR,
3046 convert (unsigned_type, rhs),
3047 size_int (lbitpos), 0),
3050 return build (code, compare_type,
3051 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
3055 /* Subroutine for fold_truthop: decode a field reference.
3057 If EXP is a comparison reference, we return the innermost reference.
3059 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3060 set to the starting bit number.
3062 If the innermost field can be completely contained in a mode-sized
3063 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3065 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3066 otherwise it is not changed.
3068 *PUNSIGNEDP is set to the signedness of the field.
3070 *PMASK is set to the mask used. This is either contained in a
3071 BIT_AND_EXPR or derived from the width of the field.
3073 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3075 Return 0 if this is not a component reference or is one that we can't
3076 do anything with. */
3079 decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp,
3080 pvolatilep, pmask, pand_mask)
3082 HOST_WIDE_INT *pbitsize, *pbitpos;
3083 enum machine_mode *pmode;
3084 int *punsignedp, *pvolatilep;
3089 tree mask, inner, offset;
3091 unsigned int precision;
3092 unsigned int alignment;
3094 /* All the optimizations using this function assume integer fields.
3095 There are problems with FP fields since the type_for_size call
3096 below can fail for, e.g., XFmode. */
3097 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3102 if (TREE_CODE (exp) == BIT_AND_EXPR)
3104 and_mask = TREE_OPERAND (exp, 1);
3105 exp = TREE_OPERAND (exp, 0);
3106 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3107 if (TREE_CODE (and_mask) != INTEGER_CST)
3111 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3112 punsignedp, pvolatilep, &alignment);
3113 if ((inner == exp && and_mask == 0)
3114 || *pbitsize < 0 || offset != 0
3115 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3118 /* Compute the mask to access the bitfield. */
3119 unsigned_type = type_for_size (*pbitsize, 1);
3120 precision = TYPE_PRECISION (unsigned_type);
3122 mask = build_int_2 (~0, ~0);
3123 TREE_TYPE (mask) = unsigned_type;
3124 force_fit_type (mask, 0);
3125 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3126 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3128 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3130 mask = fold (build (BIT_AND_EXPR, unsigned_type,
3131 convert (unsigned_type, and_mask), mask));
3134 *pand_mask = and_mask;
3138 /* Return non-zero if MASK represents a mask of SIZE ones in the low-order
3142 all_ones_mask_p (mask, size)
3146 tree type = TREE_TYPE (mask);
3147 unsigned int precision = TYPE_PRECISION (type);
3150 tmask = build_int_2 (~0, ~0);
3151 TREE_TYPE (tmask) = signed_type (type);
3152 force_fit_type (tmask, 0);
3154 tree_int_cst_equal (mask,
3155 const_binop (RSHIFT_EXPR,
3156 const_binop (LSHIFT_EXPR, tmask,
3157 size_int (precision - size),
3159 size_int (precision - size), 0));
3162 /* Subroutine for fold_truthop: determine if an operand is simple enough
3163 to be evaluated unconditionally. */
3166 simple_operand_p (exp)
3169 /* Strip any conversions that don't change the machine mode. */
3170 while ((TREE_CODE (exp) == NOP_EXPR
3171 || TREE_CODE (exp) == CONVERT_EXPR)
3172 && (TYPE_MODE (TREE_TYPE (exp))
3173 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
3174 exp = TREE_OPERAND (exp, 0);
3176 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
3178 && ! TREE_ADDRESSABLE (exp)
3179 && ! TREE_THIS_VOLATILE (exp)
3180 && ! DECL_NONLOCAL (exp)
3181 /* Don't regard global variables as simple. They may be
3182 allocated in ways unknown to the compiler (shared memory,
3183 #pragma weak, etc). */
3184 && ! TREE_PUBLIC (exp)
3185 && ! DECL_EXTERNAL (exp)
3186 /* Loading a static variable is unduly expensive, but global
3187 registers aren't expensive. */
3188 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3191 /* The following functions are subroutines to fold_range_test and allow it to
3192 try to change a logical combination of comparisons into a range test.
3195 X == 2 || X == 3 || X == 4 || X == 5
3199 (unsigned) (X - 2) <= 3
3201 We describe each set of comparisons as being either inside or outside
3202 a range, using a variable named like IN_P, and then describe the
3203 range with a lower and upper bound. If one of the bounds is omitted,
3204 it represents either the highest or lowest value of the type.
3206 In the comments below, we represent a range by two numbers in brackets
3207 preceded by a "+" to designate being inside that range, or a "-" to
3208 designate being outside that range, so the condition can be inverted by
3209 flipping the prefix. An omitted bound is represented by a "-". For
3210 example, "- [-, 10]" means being outside the range starting at the lowest
3211 possible value and ending at 10, in other words, being greater than 10.
3212 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3215 We set up things so that the missing bounds are handled in a consistent
3216 manner so neither a missing bound nor "true" and "false" need to be
3217 handled using a special case. */
3219 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3220 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3221 and UPPER1_P are nonzero if the respective argument is an upper bound
3222 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3223 must be specified for a comparison. ARG1 will be converted to ARG0's
3224 type if both are specified. */
3227 range_binop (code, type, arg0, upper0_p, arg1, upper1_p)
3228 enum tree_code code;
3231 int upper0_p, upper1_p;
3237 /* If neither arg represents infinity, do the normal operation.
3238 Else, if not a comparison, return infinity. Else handle the special
3239 comparison rules. Note that most of the cases below won't occur, but
3240 are handled for consistency. */
3242 if (arg0 != 0 && arg1 != 0)
3244 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
3245 arg0, convert (TREE_TYPE (arg0), arg1)));
3247 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3250 if (TREE_CODE_CLASS (code) != '<')
3253 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3254 for neither. In real maths, we cannot assume open ended ranges are
3255 the same. But, this is computer arithmetic, where numbers are finite.
3256 We can therefore make the transformation of any unbounded range with
3257 the value Z, Z being greater than any representable number. This permits
3258 us to treat unbounded ranges as equal. */
3259 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3260 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3264 result = sgn0 == sgn1;
3267 result = sgn0 != sgn1;
3270 result = sgn0 < sgn1;
3273 result = sgn0 <= sgn1;
3276 result = sgn0 > sgn1;
3279 result = sgn0 >= sgn1;
3285 return convert (type, result ? integer_one_node : integer_zero_node);
3288 /* Given EXP, a logical expression, set the range it is testing into
3289 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3290 actually being tested. *PLOW and *PHIGH will be made of the same type
3291 as the returned expression. If EXP is not a comparison, we will most
3292 likely not be returning a useful value and range. */
3295 make_range (exp, pin_p, plow, phigh)
3300 enum tree_code code;
3301 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
3302 tree orig_type = NULL_TREE;
3304 tree low, high, n_low, n_high;
3306 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3307 and see if we can refine the range. Some of the cases below may not
3308 happen, but it doesn't seem worth worrying about this. We "continue"
3309 the outer loop when we've changed something; otherwise we "break"
3310 the switch, which will "break" the while. */
3312 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
3316 code = TREE_CODE (exp);
3318 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3320 arg0 = TREE_OPERAND (exp, 0);
3321 if (TREE_CODE_CLASS (code) == '<'
3322 || TREE_CODE_CLASS (code) == '1'
3323 || TREE_CODE_CLASS (code) == '2')
3324 type = TREE_TYPE (arg0);
3325 if (TREE_CODE_CLASS (code) == '2'
3326 || TREE_CODE_CLASS (code) == '<'
3327 || (TREE_CODE_CLASS (code) == 'e'
3328 && TREE_CODE_LENGTH (code) > 1))
3329 arg1 = TREE_OPERAND (exp, 1);
3332 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3333 lose a cast by accident. */
3334 if (type != NULL_TREE && orig_type == NULL_TREE)
3339 case TRUTH_NOT_EXPR:
3340 in_p = ! in_p, exp = arg0;
3343 case EQ_EXPR: case NE_EXPR:
3344 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3345 /* We can only do something if the range is testing for zero
3346 and if the second operand is an integer constant. Note that
3347 saying something is "in" the range we make is done by
3348 complementing IN_P since it will set in the initial case of
3349 being not equal to zero; "out" is leaving it alone. */
3350 if (low == 0 || high == 0
3351 || ! integer_zerop (low) || ! integer_zerop (high)
3352 || TREE_CODE (arg1) != INTEGER_CST)
3357 case NE_EXPR: /* - [c, c] */
3360 case EQ_EXPR: /* + [c, c] */
3361 in_p = ! in_p, low = high = arg1;
3363 case GT_EXPR: /* - [-, c] */
3364 low = 0, high = arg1;
3366 case GE_EXPR: /* + [c, -] */
3367 in_p = ! in_p, low = arg1, high = 0;
3369 case LT_EXPR: /* - [c, -] */
3370 low = arg1, high = 0;
3372 case LE_EXPR: /* + [-, c] */
3373 in_p = ! in_p, low = 0, high = arg1;
3381 /* If this is an unsigned comparison, we also know that EXP is
3382 greater than or equal to zero. We base the range tests we make
3383 on that fact, so we record it here so we can parse existing
3385 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3387 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3388 1, convert (type, integer_zero_node),
3392 in_p = n_in_p, low = n_low, high = n_high;
3394 /* If the high bound is missing, but we
3395 have a low bound, reverse the range so
3396 it goes from zero to the low bound minus 1. */
3397 if (high == 0 && low)
3400 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3401 integer_one_node, 0);
3402 low = convert (type, integer_zero_node);
3408 /* (-x) IN [a,b] -> x in [-b, -a] */
3409 n_low = range_binop (MINUS_EXPR, type,
3410 convert (type, integer_zero_node), 0, high, 1);
3411 n_high = range_binop (MINUS_EXPR, type,
3412 convert (type, integer_zero_node), 0, low, 0);
3413 low = n_low, high = n_high;
3419 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3420 convert (type, integer_one_node));
3423 case PLUS_EXPR: case MINUS_EXPR:
3424 if (TREE_CODE (arg1) != INTEGER_CST)
3427 /* If EXP is signed, any overflow in the computation is undefined,
3428 so we don't worry about it so long as our computations on
3429 the bounds don't overflow. For unsigned, overflow is defined
3430 and this is exactly the right thing. */
3431 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3432 type, low, 0, arg1, 0);
3433 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3434 type, high, 1, arg1, 0);
3435 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3436 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3439 /* Check for an unsigned range which has wrapped around the maximum
3440 value thus making n_high < n_low, and normalize it. */
3441 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3443 low = range_binop (PLUS_EXPR, type, n_high, 0,
3444 integer_one_node, 0);
3445 high = range_binop (MINUS_EXPR, type, n_low, 0,
3446 integer_one_node, 0);
3448 /* If the range is of the form +/- [ x+1, x ], we won't
3449 be able to normalize it. But then, it represents the
3450 whole range or the empty set, so make it
3452 if (tree_int_cst_equal (n_low, low)
3453 && tree_int_cst_equal (n_high, high))
3459 low = n_low, high = n_high;
3464 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3465 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3468 if (! INTEGRAL_TYPE_P (type)
3469 || (low != 0 && ! int_fits_type_p (low, type))
3470 || (high != 0 && ! int_fits_type_p (high, type)))
3473 n_low = low, n_high = high;
3476 n_low = convert (type, n_low);
3479 n_high = convert (type, n_high);
3481 /* If we're converting from an unsigned to a signed type,
3482 we will be doing the comparison as unsigned. The tests above
3483 have already verified that LOW and HIGH are both positive.
3485 So we have to make sure that the original unsigned value will
3486 be interpreted as positive. */
3487 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3489 tree equiv_type = type_for_mode (TYPE_MODE (type), 1);
3492 /* A range without an upper bound is, naturally, unbounded.
3493 Since convert would have cropped a very large value, use
3494 the max value for the destination type. */
3496 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3497 : TYPE_MAX_VALUE (type);
3499 high_positive = fold (build (RSHIFT_EXPR, type,
3500 convert (type, high_positive),
3501 convert (type, integer_one_node)));
3503 /* If the low bound is specified, "and" the range with the
3504 range for which the original unsigned value will be
3508 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3510 1, convert (type, integer_zero_node),
3514 in_p = (n_in_p == in_p);
3518 /* Otherwise, "or" the range with the range of the input
3519 that will be interpreted as negative. */
3520 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3522 1, convert (type, integer_zero_node),
3526 in_p = (in_p != n_in_p);
3531 low = n_low, high = n_high;
3541 /* If EXP is a constant, we can evaluate whether this is true or false. */
3542 if (TREE_CODE (exp) == INTEGER_CST)
3544 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3546 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3552 *pin_p = in_p, *plow = low, *phigh = high;
3556 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3557 type, TYPE, return an expression to test if EXP is in (or out of, depending
3558 on IN_P) the range. */
3561 build_range_check (type, exp, in_p, low, high)
3567 tree etype = TREE_TYPE (exp);
3571 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3572 return invert_truthvalue (value);
3574 else if (low == 0 && high == 0)
3575 return convert (type, integer_one_node);
3578 return fold (build (LE_EXPR, type, exp, high));
3581 return fold (build (GE_EXPR, type, exp, low));
3583 else if (operand_equal_p (low, high, 0))
3584 return fold (build (EQ_EXPR, type, exp, low));
3586 else if (TREE_UNSIGNED (etype) && integer_zerop (low))
3587 return build_range_check (type, exp, 1, 0, high);
3589 else if (integer_zerop (low))
3591 utype = unsigned_type (etype);
3592 return build_range_check (type, convert (utype, exp), 1, 0,
3593 convert (utype, high));
3596 else if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3597 && ! TREE_OVERFLOW (value))
3598 return build_range_check (type,
3599 fold (build (MINUS_EXPR, etype, exp, low)),
3600 1, convert (etype, integer_zero_node), value);
3605 /* Given two ranges, see if we can merge them into one. Return 1 if we
3606 can, 0 if we can't. Set the output range into the specified parameters. */
3609 merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
3613 tree low0, high0, low1, high1;
3621 int lowequal = ((low0 == 0 && low1 == 0)
3622 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3623 low0, 0, low1, 0)));
3624 int highequal = ((high0 == 0 && high1 == 0)
3625 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3626 high0, 1, high1, 1)));
3628 /* Make range 0 be the range that starts first, or ends last if they
3629 start at the same value. Swap them if it isn't. */
3630 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3633 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3634 high1, 1, high0, 1))))
3636 temp = in0_p, in0_p = in1_p, in1_p = temp;
3637 tem = low0, low0 = low1, low1 = tem;
3638 tem = high0, high0 = high1, high1 = tem;
3641 /* Now flag two cases, whether the ranges are disjoint or whether the
3642 second range is totally subsumed in the first. Note that the tests
3643 below are simplified by the ones above. */
3644 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3645 high0, 1, low1, 0));
3646 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3647 high1, 1, high0, 1));
3649 /* We now have four cases, depending on whether we are including or
3650 excluding the two ranges. */
3653 /* If they don't overlap, the result is false. If the second range
3654 is a subset it is the result. Otherwise, the range is from the start
3655 of the second to the end of the first. */
3657 in_p = 0, low = high = 0;
3659 in_p = 1, low = low1, high = high1;
3661 in_p = 1, low = low1, high = high0;
3664 else if (in0_p && ! in1_p)
3666 /* If they don't overlap, the result is the first range. If they are
3667 equal, the result is false. If the second range is a subset of the
3668 first, and the ranges begin at the same place, we go from just after
3669 the end of the first range to the end of the second. If the second
3670 range is not a subset of the first, or if it is a subset and both
3671 ranges end at the same place, the range starts at the start of the
3672 first range and ends just before the second range.
3673 Otherwise, we can't describe this as a single range. */
3675 in_p = 1, low = low0, high = high0;
3676 else if (lowequal && highequal)
3677 in_p = 0, low = high = 0;
3678 else if (subset && lowequal)
3680 in_p = 1, high = high0;
3681 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3682 integer_one_node, 0);
3684 else if (! subset || highequal)
3686 in_p = 1, low = low0;
3687 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3688 integer_one_node, 0);
3694 else if (! in0_p && in1_p)
3696 /* If they don't overlap, the result is the second range. If the second
3697 is a subset of the first, the result is false. Otherwise,
3698 the range starts just after the first range and ends at the
3699 end of the second. */
3701 in_p = 1, low = low1, high = high1;
3702 else if (subset || highequal)
3703 in_p = 0, low = high = 0;
3706 in_p = 1, high = high1;
3707 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3708 integer_one_node, 0);
3714 /* The case where we are excluding both ranges. Here the complex case
3715 is if they don't overlap. In that case, the only time we have a
3716 range is if they are adjacent. If the second is a subset of the
3717 first, the result is the first. Otherwise, the range to exclude
3718 starts at the beginning of the first range and ends at the end of the
3722 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3723 range_binop (PLUS_EXPR, NULL_TREE,
3725 integer_one_node, 1),
3727 in_p = 0, low = low0, high = high1;
3732 in_p = 0, low = low0, high = high0;
3734 in_p = 0, low = low0, high = high1;
3737 *pin_p = in_p, *plow = low, *phigh = high;
3741 /* EXP is some logical combination of boolean tests. See if we can
3742 merge it into some range test. Return the new tree if so. */
3745 fold_range_test (exp)
3748 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3749 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3750 int in0_p, in1_p, in_p;
3751 tree low0, low1, low, high0, high1, high;
3752 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3753 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3756 /* If this is an OR operation, invert both sides; we will invert
3757 again at the end. */
3759 in0_p = ! in0_p, in1_p = ! in1_p;
3761 /* If both expressions are the same, if we can merge the ranges, and we
3762 can build the range test, return it or it inverted. If one of the
3763 ranges is always true or always false, consider it to be the same
3764 expression as the other. */
3765 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3766 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3768 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3770 : rhs != 0 ? rhs : integer_zero_node,
3772 return or_op ? invert_truthvalue (tem) : tem;
3774 /* On machines where the branch cost is expensive, if this is a
3775 short-circuited branch and the underlying object on both sides
3776 is the same, make a non-short-circuit operation. */
3777 else if (BRANCH_COST >= 2
3778 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3779 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3780 && operand_equal_p (lhs, rhs, 0))
3782 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3783 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3784 which cases we can't do this. */
3785 if (simple_operand_p (lhs))
3786 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3787 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3788 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3789 TREE_OPERAND (exp, 1));
3791 else if (global_bindings_p () == 0
3792 && ! contains_placeholder_p (lhs))
3794 tree common = save_expr (lhs);
3796 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3797 or_op ? ! in0_p : in0_p,
3799 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3800 or_op ? ! in1_p : in1_p,
3802 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3803 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3804 TREE_TYPE (exp), lhs, rhs);
3811 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3812 bit value. Arrange things so the extra bits will be set to zero if and
3813 only if C is signed-extended to its full width. If MASK is nonzero,
3814 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3817 unextend (c, p, unsignedp, mask)
3823 tree type = TREE_TYPE (c);
3824 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3827 if (p == modesize || unsignedp)
3830 /* We work by getting just the sign bit into the low-order bit, then
3831 into the high-order bit, then sign-extend. We then XOR that value
3833 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3834 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3836 /* We must use a signed type in order to get an arithmetic right shift.
3837 However, we must also avoid introducing accidental overflows, so that
3838 a subsequent call to integer_zerop will work. Hence we must
3839 do the type conversion here. At this point, the constant is either
3840 zero or one, and the conversion to a signed type can never overflow.
3841 We could get an overflow if this conversion is done anywhere else. */
3842 if (TREE_UNSIGNED (type))
3843 temp = convert (signed_type (type), temp);
3845 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3846 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3848 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3849 /* If necessary, convert the type back to match the type of C. */
3850 if (TREE_UNSIGNED (type))
3851 temp = convert (type, temp);
3853 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3856 /* Find ways of folding logical expressions of LHS and RHS:
3857 Try to merge two comparisons to the same innermost item.
3858 Look for range tests like "ch >= '0' && ch <= '9'".
3859 Look for combinations of simple terms on machines with expensive branches
3860 and evaluate the RHS unconditionally.
3862 For example, if we have p->a == 2 && p->b == 4 and we can make an
3863 object large enough to span both A and B, we can do this with a comparison
3864 against the object ANDed with the a mask.
3866 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3867 operations to do this with one comparison.
3869 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3870 function and the one above.
3872 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3873 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3875 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3878 We return the simplified tree or 0 if no optimization is possible. */
3881 fold_truthop (code, truth_type, lhs, rhs)
3882 enum tree_code code;
3883 tree truth_type, lhs, rhs;
3885 /* If this is the "or" of two comparisons, we can do something if
3886 the comparisons are NE_EXPR. If this is the "and", we can do something
3887 if the comparisons are EQ_EXPR. I.e.,
3888 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3890 WANTED_CODE is this operation code. For single bit fields, we can
3891 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3892 comparison for one-bit fields. */
3894 enum tree_code wanted_code;
3895 enum tree_code lcode, rcode;
3896 tree ll_arg, lr_arg, rl_arg, rr_arg;
3897 tree ll_inner, lr_inner, rl_inner, rr_inner;
3898 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3899 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3900 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3901 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3902 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3903 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3904 enum machine_mode lnmode, rnmode;
3905 tree ll_mask, lr_mask, rl_mask, rr_mask;
3906 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3907 tree l_const, r_const;
3908 tree lntype, rntype, result;
3909 int first_bit, end_bit;
3912 /* Start by getting the comparison codes. Fail if anything is volatile.
3913 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3914 it were surrounded with a NE_EXPR. */
3916 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3919 lcode = TREE_CODE (lhs);
3920 rcode = TREE_CODE (rhs);
3922 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3923 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3925 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3926 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3928 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3931 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3932 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3934 ll_arg = TREE_OPERAND (lhs, 0);
3935 lr_arg = TREE_OPERAND (lhs, 1);
3936 rl_arg = TREE_OPERAND (rhs, 0);
3937 rr_arg = TREE_OPERAND (rhs, 1);
3939 /* If the RHS can be evaluated unconditionally and its operands are
3940 simple, it wins to evaluate the RHS unconditionally on machines
3941 with expensive branches. In this case, this isn't a comparison
3942 that can be merged. Avoid doing this if the RHS is a floating-point
3943 comparison since those can trap. */
3945 if (BRANCH_COST >= 2
3946 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
3947 && simple_operand_p (rl_arg)
3948 && simple_operand_p (rr_arg))
3949 return build (code, truth_type, lhs, rhs);
3951 /* See if the comparisons can be merged. Then get all the parameters for
3954 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3955 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3959 ll_inner = decode_field_reference (ll_arg,
3960 &ll_bitsize, &ll_bitpos, &ll_mode,
3961 &ll_unsignedp, &volatilep, &ll_mask,
3963 lr_inner = decode_field_reference (lr_arg,
3964 &lr_bitsize, &lr_bitpos, &lr_mode,
3965 &lr_unsignedp, &volatilep, &lr_mask,
3967 rl_inner = decode_field_reference (rl_arg,
3968 &rl_bitsize, &rl_bitpos, &rl_mode,
3969 &rl_unsignedp, &volatilep, &rl_mask,
3971 rr_inner = decode_field_reference (rr_arg,
3972 &rr_bitsize, &rr_bitpos, &rr_mode,
3973 &rr_unsignedp, &volatilep, &rr_mask,
3976 /* It must be true that the inner operation on the lhs of each
3977 comparison must be the same if we are to be able to do anything.
3978 Then see if we have constants. If not, the same must be true for
3980 if (volatilep || ll_inner == 0 || rl_inner == 0
3981 || ! operand_equal_p (ll_inner, rl_inner, 0))
3984 if (TREE_CODE (lr_arg) == INTEGER_CST
3985 && TREE_CODE (rr_arg) == INTEGER_CST)
3986 l_const = lr_arg, r_const = rr_arg;
3987 else if (lr_inner == 0 || rr_inner == 0
3988 || ! operand_equal_p (lr_inner, rr_inner, 0))
3991 l_const = r_const = 0;
3993 /* If either comparison code is not correct for our logical operation,
3994 fail. However, we can convert a one-bit comparison against zero into
3995 the opposite comparison against that bit being set in the field. */
3997 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
3998 if (lcode != wanted_code)
4000 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
4002 /* Make the left operand unsigned, since we are only interested
4003 in the value of one bit. Otherwise we are doing the wrong
4012 /* This is analogous to the code for l_const above. */
4013 if (rcode != wanted_code)
4015 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
4024 /* See if we can find a mode that contains both fields being compared on
4025 the left. If we can't, fail. Otherwise, update all constants and masks
4026 to be relative to a field of that size. */
4027 first_bit = MIN (ll_bitpos, rl_bitpos);
4028 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
4029 lnmode = get_best_mode (end_bit - first_bit, first_bit,
4030 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
4032 if (lnmode == VOIDmode)
4035 lnbitsize = GET_MODE_BITSIZE (lnmode);
4036 lnbitpos = first_bit & ~ (lnbitsize - 1);
4037 lntype = type_for_size (lnbitsize, 1);
4038 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4040 if (BYTES_BIG_ENDIAN)
4042 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4043 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4046 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
4047 size_int (xll_bitpos), 0);
4048 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
4049 size_int (xrl_bitpos), 0);
4053 l_const = convert (lntype, l_const);
4054 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4055 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4056 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4057 fold (build1 (BIT_NOT_EXPR,
4061 warning ("comparison is always %d", wanted_code == NE_EXPR);
4063 return convert (truth_type,
4064 wanted_code == NE_EXPR
4065 ? integer_one_node : integer_zero_node);
4070 r_const = convert (lntype, r_const);
4071 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4072 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4073 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4074 fold (build1 (BIT_NOT_EXPR,
4078 warning ("comparison is always %d", wanted_code == NE_EXPR);
4080 return convert (truth_type,
4081 wanted_code == NE_EXPR
4082 ? integer_one_node : integer_zero_node);
4086 /* If the right sides are not constant, do the same for it. Also,
4087 disallow this optimization if a size or signedness mismatch occurs
4088 between the left and right sides. */
4091 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4092 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4093 /* Make sure the two fields on the right
4094 correspond to the left without being swapped. */
4095 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4098 first_bit = MIN (lr_bitpos, rr_bitpos);
4099 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4100 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4101 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4103 if (rnmode == VOIDmode)
4106 rnbitsize = GET_MODE_BITSIZE (rnmode);
4107 rnbitpos = first_bit & ~ (rnbitsize - 1);
4108 rntype = type_for_size (rnbitsize, 1);
4109 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4111 if (BYTES_BIG_ENDIAN)
4113 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4114 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4117 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
4118 size_int (xlr_bitpos), 0);
4119 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
4120 size_int (xrr_bitpos), 0);
4122 /* Make a mask that corresponds to both fields being compared.
4123 Do this for both items being compared. If the operands are the
4124 same size and the bits being compared are in the same position
4125 then we can do this by masking both and comparing the masked
4127 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4128 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4129 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4131 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4132 ll_unsignedp || rl_unsignedp);
4133 if (! all_ones_mask_p (ll_mask, lnbitsize))
4134 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
4136 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4137 lr_unsignedp || rr_unsignedp);
4138 if (! all_ones_mask_p (lr_mask, rnbitsize))
4139 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
4141 return build (wanted_code, truth_type, lhs, rhs);
4144 /* There is still another way we can do something: If both pairs of
4145 fields being compared are adjacent, we may be able to make a wider
4146 field containing them both.
4148 Note that we still must mask the lhs/rhs expressions. Furthermore,
4149 the mask must be shifted to account for the shift done by
4150 make_bit_field_ref. */
4151 if ((ll_bitsize + ll_bitpos == rl_bitpos
4152 && lr_bitsize + lr_bitpos == rr_bitpos)
4153 || (ll_bitpos == rl_bitpos + rl_bitsize
4154 && lr_bitpos == rr_bitpos + rr_bitsize))
4158 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4159 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4160 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4161 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4163 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4164 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4165 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4166 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4168 /* Convert to the smaller type before masking out unwanted bits. */
4170 if (lntype != rntype)
4172 if (lnbitsize > rnbitsize)
4174 lhs = convert (rntype, lhs);
4175 ll_mask = convert (rntype, ll_mask);
4178 else if (lnbitsize < rnbitsize)
4180 rhs = convert (lntype, rhs);
4181 lr_mask = convert (lntype, lr_mask);
4186 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4187 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
4189 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4190 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
4192 return build (wanted_code, truth_type, lhs, rhs);
4198 /* Handle the case of comparisons with constants. If there is something in
4199 common between the masks, those bits of the constants must be the same.
4200 If not, the condition is always false. Test for this to avoid generating
4201 incorrect code below. */
4202 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4203 if (! integer_zerop (result)
4204 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4205 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4207 if (wanted_code == NE_EXPR)
4209 warning ("`or' of unmatched not-equal tests is always 1");
4210 return convert (truth_type, integer_one_node);
4214 warning ("`and' of mutually exclusive equal-tests is always 0");
4215 return convert (truth_type, integer_zero_node);
4219 /* Construct the expression we will return. First get the component
4220 reference we will make. Unless the mask is all ones the width of
4221 that field, perform the mask operation. Then compare with the
4223 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4224 ll_unsignedp || rl_unsignedp);
4226 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4227 if (! all_ones_mask_p (ll_mask, lnbitsize))
4228 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
4230 return build (wanted_code, truth_type, result,
4231 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4234 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4238 optimize_minmax_comparison (t)
4241 tree type = TREE_TYPE (t);
4242 tree arg0 = TREE_OPERAND (t, 0);
4243 enum tree_code op_code;
4244 tree comp_const = TREE_OPERAND (t, 1);
4246 int consts_equal, consts_lt;
4249 STRIP_SIGN_NOPS (arg0);
4251 op_code = TREE_CODE (arg0);
4252 minmax_const = TREE_OPERAND (arg0, 1);
4253 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4254 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4255 inner = TREE_OPERAND (arg0, 0);
4257 /* If something does not permit us to optimize, return the original tree. */
4258 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4259 || TREE_CODE (comp_const) != INTEGER_CST
4260 || TREE_CONSTANT_OVERFLOW (comp_const)
4261 || TREE_CODE (minmax_const) != INTEGER_CST
4262 || TREE_CONSTANT_OVERFLOW (minmax_const))
4265 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4266 and GT_EXPR, doing the rest with recursive calls using logical
4268 switch (TREE_CODE (t))
4270 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4272 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4276 fold (build (TRUTH_ORIF_EXPR, type,
4277 optimize_minmax_comparison
4278 (build (EQ_EXPR, type, arg0, comp_const)),
4279 optimize_minmax_comparison
4280 (build (GT_EXPR, type, arg0, comp_const))));
4283 if (op_code == MAX_EXPR && consts_equal)
4284 /* MAX (X, 0) == 0 -> X <= 0 */
4285 return fold (build (LE_EXPR, type, inner, comp_const));
4287 else if (op_code == MAX_EXPR && consts_lt)
4288 /* MAX (X, 0) == 5 -> X == 5 */
4289 return fold (build (EQ_EXPR, type, inner, comp_const));
4291 else if (op_code == MAX_EXPR)
4292 /* MAX (X, 0) == -1 -> false */
4293 return omit_one_operand (type, integer_zero_node, inner);
4295 else if (consts_equal)
4296 /* MIN (X, 0) == 0 -> X >= 0 */
4297 return fold (build (GE_EXPR, type, inner, comp_const));
4300 /* MIN (X, 0) == 5 -> false */
4301 return omit_one_operand (type, integer_zero_node, inner);
4304 /* MIN (X, 0) == -1 -> X == -1 */
4305 return fold (build (EQ_EXPR, type, inner, comp_const));
4308 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4309 /* MAX (X, 0) > 0 -> X > 0
4310 MAX (X, 0) > 5 -> X > 5 */
4311 return fold (build (GT_EXPR, type, inner, comp_const));
4313 else if (op_code == MAX_EXPR)
4314 /* MAX (X, 0) > -1 -> true */
4315 return omit_one_operand (type, integer_one_node, inner);
4317 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4318 /* MIN (X, 0) > 0 -> false
4319 MIN (X, 0) > 5 -> false */
4320 return omit_one_operand (type, integer_zero_node, inner);
4323 /* MIN (X, 0) > -1 -> X > -1 */
4324 return fold (build (GT_EXPR, type, inner, comp_const));
4331 /* T is an integer expression that is being multiplied, divided, or taken a
4332 modulus (CODE says which and what kind of divide or modulus) by a
4333 constant C. See if we can eliminate that operation by folding it with
4334 other operations already in T. WIDE_TYPE, if non-null, is a type that
4335 should be used for the computation if wider than our type.
4337 For example, if we are dividing (X * 8) + (Y + 16) by 4, we can return
4338 (X * 2) + (Y + 4). We must, however, be assured that either the original
4339 expression would not overflow or that overflow is undefined for the type
4340 in the language in question.
4342 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4343 the machine has a multiply-accumulate insn or that this is part of an
4344 addressing calculation.
4346 If we return a non-null expression, it is an equivalent form of the
4347 original computation, but need not be in the original type. */
4350 extract_muldiv (t, c, code, wide_type)
4353 enum tree_code code;
4356 tree type = TREE_TYPE (t);
4357 enum tree_code tcode = TREE_CODE (t);
4358 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4359 > GET_MODE_SIZE (TYPE_MODE (type)))
4360 ? wide_type : type);
4362 int same_p = tcode == code;
4363 tree op0 = NULL_TREE, op1 = NULL_TREE;
4365 /* Don't deal with constants of zero here; they confuse the code below. */
4366 if (integer_zerop (c))
4369 if (TREE_CODE_CLASS (tcode) == '1')
4370 op0 = TREE_OPERAND (t, 0);
4372 if (TREE_CODE_CLASS (tcode) == '2')
4373 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4375 /* Note that we need not handle conditional operations here since fold
4376 already handles those cases. So just do arithmetic here. */
4380 /* For a constant, we can always simplify if we are a multiply
4381 or (for divide and modulus) if it is a multiple of our constant. */
4382 if (code == MULT_EXPR
4383 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4384 return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
4387 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4388 /* If op0 is an expression, and is unsigned, and the type is
4389 smaller than ctype, then we cannot widen the expression. */
4390 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
4391 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
4392 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
4393 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
4394 && TREE_UNSIGNED (TREE_TYPE (op0))
4395 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
4396 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
4397 && (GET_MODE_SIZE (TYPE_MODE (ctype))
4398 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
4401 /* Pass the constant down and see if we can make a simplification. If
4402 we can, replace this expression with the inner simplification for
4403 possible later conversion to our or some other type. */
4404 if (0 != (t1 = extract_muldiv (op0, convert (TREE_TYPE (op0), c), code,
4405 code == MULT_EXPR ? ctype : NULL_TREE)))
4409 case NEGATE_EXPR: case ABS_EXPR:
4410 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4411 return fold (build1 (tcode, ctype, convert (ctype, t1)));
4414 case MIN_EXPR: case MAX_EXPR:
4415 /* If widening the type changes the signedness, then we can't perform
4416 this optimization as that changes the result. */
4417 if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
4420 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4421 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4422 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4424 if (tree_int_cst_sgn (c) < 0)
4425 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4427 return fold (build (tcode, ctype, convert (ctype, t1),
4428 convert (ctype, t2)));
4432 case WITH_RECORD_EXPR:
4433 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4434 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4435 TREE_OPERAND (t, 1));
4439 /* If this has not been evaluated and the operand has no side effects,
4440 we can see if we can do something inside it and make a new one.
4441 Note that this test is overly conservative since we can do this
4442 if the only reason it had side effects is that it was another
4443 similar SAVE_EXPR, but that isn't worth bothering with. */
4444 if (SAVE_EXPR_RTL (t) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
4445 && 0 != (t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code,
4447 return save_expr (t1);
4450 case LSHIFT_EXPR: case RSHIFT_EXPR:
4451 /* If the second operand is constant, this is a multiplication
4452 or floor division, by a power of two, so we can treat it that
4453 way unless the multiplier or divisor overflows. */
4454 if (TREE_CODE (op1) == INTEGER_CST
4455 /* const_binop may not detect overflow correctly,
4456 so check for it explicitly here. */
4457 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
4458 && TREE_INT_CST_HIGH (op1) == 0
4459 && 0 != (t1 = convert (ctype,
4460 const_binop (LSHIFT_EXPR, size_one_node,
4462 && ! TREE_OVERFLOW (t1))
4463 return extract_muldiv (build (tcode == LSHIFT_EXPR
4464 ? MULT_EXPR : FLOOR_DIV_EXPR,
4465 ctype, convert (ctype, op0), t1),
4466 c, code, wide_type);
4469 case PLUS_EXPR: case MINUS_EXPR:
4470 /* See if we can eliminate the operation on both sides. If we can, we
4471 can return a new PLUS or MINUS. If we can't, the only remaining
4472 cases where we can do anything are if the second operand is a
4474 t1 = extract_muldiv (op0, c, code, wide_type);
4475 t2 = extract_muldiv (op1, c, code, wide_type);
4476 if (t1 != 0 && t2 != 0)
4477 return fold (build (tcode, ctype, convert (ctype, t1),
4478 convert (ctype, t2)));
4480 /* If this was a subtraction, negate OP1 and set it to be an addition.
4481 This simplifies the logic below. */
4482 if (tcode == MINUS_EXPR)
4483 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4485 if (TREE_CODE (op1) != INTEGER_CST)
4488 /* If either OP1 or C are negative, this optimization is not safe for
4489 some of the division and remainder types while for others we need
4490 to change the code. */
4491 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4493 if (code == CEIL_DIV_EXPR)
4494 code = FLOOR_DIV_EXPR;
4495 else if (code == CEIL_MOD_EXPR)
4496 code = FLOOR_MOD_EXPR;
4497 else if (code == FLOOR_DIV_EXPR)
4498 code = CEIL_DIV_EXPR;
4499 else if (code == FLOOR_MOD_EXPR)
4500 code = CEIL_MOD_EXPR;
4501 else if (code != MULT_EXPR)
4505 /* If it's a multiply or a division/modulus operation of a multiple
4506 of our constant, do the operation and verify it doesn't overflow. */
4507 if (code == MULT_EXPR
4508 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4510 op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
4511 if (op1 == 0 || TREE_OVERFLOW (op1))
4517 /* If we have an unsigned type is not a sizetype, we cannot widen
4518 the operation since it will change the result if the original
4519 computation overflowed. */
4520 if (TREE_UNSIGNED (ctype)
4521 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
4525 /* If we were able to eliminate our operation from the first side,
4526 apply our operation to the second side and reform the PLUS. */
4527 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4528 return fold (build (tcode, ctype, convert (ctype, t1), op1));
4530 /* The last case is if we are a multiply. In that case, we can
4531 apply the distributive law to commute the multiply and addition
4532 if the multiplication of the constants doesn't overflow. */
4533 if (code == MULT_EXPR)
4534 return fold (build (tcode, ctype, fold (build (code, ctype,
4535 convert (ctype, op0),
4536 convert (ctype, c))),
4542 /* We have a special case here if we are doing something like
4543 (C * 8) % 4 since we know that's zero. */
4544 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4545 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4546 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4547 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4548 return omit_one_operand (type, integer_zero_node, op0);
4550 /* ... fall through ... */
4552 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4553 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4554 /* If we can extract our operation from the LHS, do so and return a
4555 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4556 do something only if the second operand is a constant. */
4558 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4559 return fold (build (tcode, ctype, convert (ctype, t1),
4560 convert (ctype, op1)));
4561 else if (tcode == MULT_EXPR && code == MULT_EXPR
4562 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4563 return fold (build (tcode, ctype, convert (ctype, op0),
4564 convert (ctype, t1)));
4565 else if (TREE_CODE (op1) != INTEGER_CST)
4568 /* If these are the same operation types, we can associate them
4569 assuming no overflow. */
4571 && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
4572 convert (ctype, c), 0))
4573 && ! TREE_OVERFLOW (t1))
4574 return fold (build (tcode, ctype, convert (ctype, op0), t1));
4576 /* If these operations "cancel" each other, we have the main
4577 optimizations of this pass, which occur when either constant is a
4578 multiple of the other, in which case we replace this with either an
4579 operation or CODE or TCODE.
4581 If we have an unsigned type that is not a sizetype, we canot do
4582 this since it will change the result if the original computation
4584 if ((! TREE_UNSIGNED (ctype)
4585 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
4586 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4587 || (tcode == MULT_EXPR
4588 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4589 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
4591 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4592 return fold (build (tcode, ctype, convert (ctype, op0),
4594 const_binop (TRUNC_DIV_EXPR,
4596 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4597 return fold (build (code, ctype, convert (ctype, op0),
4599 const_binop (TRUNC_DIV_EXPR,
4611 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4612 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4613 that we may sometimes modify the tree. */
4616 strip_compound_expr (t, s)
4620 enum tree_code code = TREE_CODE (t);
4622 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4623 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4624 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4625 return TREE_OPERAND (t, 1);
4627 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4628 don't bother handling any other types. */
4629 else if (code == COND_EXPR)
4631 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4632 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4633 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4635 else if (TREE_CODE_CLASS (code) == '1')
4636 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4637 else if (TREE_CODE_CLASS (code) == '<'
4638 || TREE_CODE_CLASS (code) == '2')
4640 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4641 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4647 /* Return a node which has the indicated constant VALUE (either 0 or
4648 1), and is of the indicated TYPE. */
4651 constant_boolean_node (value, type)
4655 if (type == integer_type_node)
4656 return value ? integer_one_node : integer_zero_node;
4657 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4658 return truthvalue_conversion (value ? integer_one_node :
4662 tree t = build_int_2 (value, 0);
4664 TREE_TYPE (t) = type;
4669 /* Utility function for the following routine, to see how complex a nesting of
4670 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4671 we don't care (to avoid spending too much time on complex expressions.). */
4674 count_cond (expr, lim)
4680 if (TREE_CODE (expr) != COND_EXPR)
4685 true = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4686 false = count_cond (TREE_OPERAND (expr, 2), lim - 1 - true);
4687 return MIN (lim, 1 + true + false);
4690 /* Perform constant folding and related simplification of EXPR.
4691 The related simplifications include x*1 => x, x*0 => 0, etc.,
4692 and application of the associative law.
4693 NOP_EXPR conversions may be removed freely (as long as we
4694 are careful not to change the C type of the overall expression)
4695 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4696 but we can constant-fold them if they have constant operands. */
4702 register tree t = expr;
4703 tree t1 = NULL_TREE;
4705 tree type = TREE_TYPE (expr);
4706 register tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4707 register enum tree_code code = TREE_CODE (t);
4710 /* WINS will be nonzero when the switch is done
4711 if all operands are constant. */
4714 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4715 Likewise for a SAVE_EXPR that's already been evaluated. */
4716 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t)) != 0)
4719 /* Return right away if already constant. */
4720 if (TREE_CONSTANT (t))
4722 if (code == CONST_DECL)
4723 return DECL_INITIAL (t);
4727 #ifdef MAX_INTEGER_COMPUTATION_MODE
4728 check_max_integer_computation_mode (expr);
4731 kind = TREE_CODE_CLASS (code);
4732 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4736 /* Special case for conversion ops that can have fixed point args. */
4737 arg0 = TREE_OPERAND (t, 0);
4739 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4741 STRIP_SIGN_NOPS (arg0);
4743 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4744 subop = TREE_REALPART (arg0);
4748 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4749 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4750 && TREE_CODE (subop) != REAL_CST
4751 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4753 /* Note that TREE_CONSTANT isn't enough:
4754 static var addresses are constant but we can't
4755 do arithmetic on them. */
4758 else if (IS_EXPR_CODE_CLASS (kind) || kind == 'r')
4760 register int len = TREE_CODE_LENGTH (code);
4762 for (i = 0; i < len; i++)
4764 tree op = TREE_OPERAND (t, i);
4768 continue; /* Valid for CALL_EXPR, at least. */
4770 if (kind == '<' || code == RSHIFT_EXPR)
4772 /* Signedness matters here. Perhaps we can refine this
4774 STRIP_SIGN_NOPS (op);
4777 /* Strip any conversions that don't change the mode. */
4780 if (TREE_CODE (op) == COMPLEX_CST)
4781 subop = TREE_REALPART (op);
4785 if (TREE_CODE (subop) != INTEGER_CST
4786 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4787 && TREE_CODE (subop) != REAL_CST
4788 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4790 /* Note that TREE_CONSTANT isn't enough:
4791 static var addresses are constant but we can't
4792 do arithmetic on them. */
4802 /* If this is a commutative operation, and ARG0 is a constant, move it
4803 to ARG1 to reduce the number of tests below. */
4804 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
4805 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
4806 || code == BIT_AND_EXPR)
4807 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
4809 tem = arg0; arg0 = arg1; arg1 = tem;
4811 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
4812 TREE_OPERAND (t, 1) = tem;
4815 /* Now WINS is set as described above,
4816 ARG0 is the first operand of EXPR,
4817 and ARG1 is the second operand (if it has more than one operand).
4819 First check for cases where an arithmetic operation is applied to a
4820 compound, conditional, or comparison operation. Push the arithmetic
4821 operation inside the compound or conditional to see if any folding
4822 can then be done. Convert comparison to conditional for this purpose.
4823 The also optimizes non-constant cases that used to be done in
4826 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
4827 one of the operands is a comparison and the other is a comparison, a
4828 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
4829 code below would make the expression more complex. Change it to a
4830 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
4831 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
4833 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
4834 || code == EQ_EXPR || code == NE_EXPR)
4835 && ((truth_value_p (TREE_CODE (arg0))
4836 && (truth_value_p (TREE_CODE (arg1))
4837 || (TREE_CODE (arg1) == BIT_AND_EXPR
4838 && integer_onep (TREE_OPERAND (arg1, 1)))))
4839 || (truth_value_p (TREE_CODE (arg1))
4840 && (truth_value_p (TREE_CODE (arg0))
4841 || (TREE_CODE (arg0) == BIT_AND_EXPR
4842 && integer_onep (TREE_OPERAND (arg0, 1)))))))
4844 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
4845 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
4849 if (code == EQ_EXPR)
4850 t = invert_truthvalue (t);
4855 if (TREE_CODE_CLASS (code) == '1')
4857 if (TREE_CODE (arg0) == COMPOUND_EXPR)
4858 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4859 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
4860 else if (TREE_CODE (arg0) == COND_EXPR)
4862 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
4863 fold (build1 (code, type, TREE_OPERAND (arg0, 1))),
4864 fold (build1 (code, type, TREE_OPERAND (arg0, 2)))));
4866 /* If this was a conversion, and all we did was to move into
4867 inside the COND_EXPR, bring it back out. But leave it if
4868 it is a conversion from integer to integer and the
4869 result precision is no wider than a word since such a
4870 conversion is cheap and may be optimized away by combine,
4871 while it couldn't if it were outside the COND_EXPR. Then return
4872 so we don't get into an infinite recursion loop taking the
4873 conversion out and then back in. */
4875 if ((code == NOP_EXPR || code == CONVERT_EXPR
4876 || code == NON_LVALUE_EXPR)
4877 && TREE_CODE (t) == COND_EXPR
4878 && TREE_CODE (TREE_OPERAND (t, 1)) == code
4879 && TREE_CODE (TREE_OPERAND (t, 2)) == code
4880 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
4881 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
4882 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
4884 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
4885 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
4886 t = build1 (code, type,
4888 TREE_TYPE (TREE_OPERAND
4889 (TREE_OPERAND (t, 1), 0)),
4890 TREE_OPERAND (t, 0),
4891 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
4892 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
4895 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
4896 return fold (build (COND_EXPR, type, arg0,
4897 fold (build1 (code, type, integer_one_node)),
4898 fold (build1 (code, type, integer_zero_node))));
4900 else if (TREE_CODE_CLASS (code) == '2'
4901 || TREE_CODE_CLASS (code) == '<')
4903 if (TREE_CODE (arg1) == COMPOUND_EXPR)
4904 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4905 fold (build (code, type,
4906 arg0, TREE_OPERAND (arg1, 1))));
4907 else if ((TREE_CODE (arg1) == COND_EXPR
4908 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
4909 && TREE_CODE_CLASS (code) != '<'))
4910 && (TREE_CODE (arg0) != COND_EXPR
4911 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4912 && (! TREE_SIDE_EFFECTS (arg0)
4913 || (global_bindings_p () == 0
4914 && ! contains_placeholder_p (arg0))))
4916 tree test, true_value, false_value;
4917 tree lhs = 0, rhs = 0;
4919 if (TREE_CODE (arg1) == COND_EXPR)
4921 test = TREE_OPERAND (arg1, 0);
4922 true_value = TREE_OPERAND (arg1, 1);
4923 false_value = TREE_OPERAND (arg1, 2);
4927 tree testtype = TREE_TYPE (arg1);
4929 true_value = convert (testtype, integer_one_node);
4930 false_value = convert (testtype, integer_zero_node);
4933 /* If ARG0 is complex we want to make sure we only evaluate
4934 it once. Though this is only required if it is volatile, it
4935 might be more efficient even if it is not. However, if we
4936 succeed in folding one part to a constant, we do not need
4937 to make this SAVE_EXPR. Since we do this optimization
4938 primarily to see if we do end up with constant and this
4939 SAVE_EXPR interferes with later optimizations, suppressing
4940 it when we can is important.
4942 If we are not in a function, we can't make a SAVE_EXPR, so don't
4943 try to do so. Don't try to see if the result is a constant
4944 if an arm is a COND_EXPR since we get exponential behavior
4947 if (TREE_CODE (arg0) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4948 && global_bindings_p () == 0
4949 && ((TREE_CODE (arg0) != VAR_DECL
4950 && TREE_CODE (arg0) != PARM_DECL)
4951 || TREE_SIDE_EFFECTS (arg0)))
4953 if (TREE_CODE (true_value) != COND_EXPR)
4954 lhs = fold (build (code, type, arg0, true_value));
4956 if (TREE_CODE (false_value) != COND_EXPR)
4957 rhs = fold (build (code, type, arg0, false_value));
4959 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4960 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4961 arg0 = save_expr (arg0), lhs = rhs = 0;
4965 lhs = fold (build (code, type, arg0, true_value));
4967 rhs = fold (build (code, type, arg0, false_value));
4969 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4971 if (TREE_CODE (arg0) == SAVE_EXPR)
4972 return build (COMPOUND_EXPR, type,
4973 convert (void_type_node, arg0),
4974 strip_compound_expr (test, arg0));
4976 return convert (type, test);
4979 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
4980 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4981 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4982 else if ((TREE_CODE (arg0) == COND_EXPR
4983 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
4984 && TREE_CODE_CLASS (code) != '<'))
4985 && (TREE_CODE (arg1) != COND_EXPR
4986 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4987 && (! TREE_SIDE_EFFECTS (arg1)
4988 || (global_bindings_p () == 0
4989 && ! contains_placeholder_p (arg1))))
4991 tree test, true_value, false_value;
4992 tree lhs = 0, rhs = 0;
4994 if (TREE_CODE (arg0) == COND_EXPR)
4996 test = TREE_OPERAND (arg0, 0);
4997 true_value = TREE_OPERAND (arg0, 1);
4998 false_value = TREE_OPERAND (arg0, 2);
5002 tree testtype = TREE_TYPE (arg0);
5004 true_value = convert (testtype, integer_one_node);
5005 false_value = convert (testtype, integer_zero_node);
5008 if (TREE_CODE (arg1) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
5009 && global_bindings_p () == 0
5010 && ((TREE_CODE (arg1) != VAR_DECL
5011 && TREE_CODE (arg1) != PARM_DECL)
5012 || TREE_SIDE_EFFECTS (arg1)))
5014 if (TREE_CODE (true_value) != COND_EXPR)
5015 lhs = fold (build (code, type, true_value, arg1));
5017 if (TREE_CODE (false_value) != COND_EXPR)
5018 rhs = fold (build (code, type, false_value, arg1));
5020 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
5021 && (rhs == 0 || !TREE_CONSTANT (rhs)))
5022 arg1 = save_expr (arg1), lhs = rhs = 0;
5026 lhs = fold (build (code, type, true_value, arg1));
5029 rhs = fold (build (code, type, false_value, arg1));
5031 test = fold (build (COND_EXPR, type, test, lhs, rhs));
5032 if (TREE_CODE (arg1) == SAVE_EXPR)
5033 return build (COMPOUND_EXPR, type,
5034 convert (void_type_node, arg1),
5035 strip_compound_expr (test, arg1));
5037 return convert (type, test);
5040 else if (TREE_CODE_CLASS (code) == '<'
5041 && TREE_CODE (arg0) == COMPOUND_EXPR)
5042 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5043 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5044 else if (TREE_CODE_CLASS (code) == '<'
5045 && TREE_CODE (arg1) == COMPOUND_EXPR)
5046 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5047 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
5059 return fold (DECL_INITIAL (t));
5064 case FIX_TRUNC_EXPR:
5065 /* Other kinds of FIX are not handled properly by fold_convert. */
5067 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
5068 return TREE_OPERAND (t, 0);
5070 /* Handle cases of two conversions in a row. */
5071 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
5072 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
5074 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5075 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
5076 tree final_type = TREE_TYPE (t);
5077 int inside_int = INTEGRAL_TYPE_P (inside_type);
5078 int inside_ptr = POINTER_TYPE_P (inside_type);
5079 int inside_float = FLOAT_TYPE_P (inside_type);
5080 unsigned int inside_prec = TYPE_PRECISION (inside_type);
5081 int inside_unsignedp = TREE_UNSIGNED (inside_type);
5082 int inter_int = INTEGRAL_TYPE_P (inter_type);
5083 int inter_ptr = POINTER_TYPE_P (inter_type);
5084 int inter_float = FLOAT_TYPE_P (inter_type);
5085 unsigned int inter_prec = TYPE_PRECISION (inter_type);
5086 int inter_unsignedp = TREE_UNSIGNED (inter_type);
5087 int final_int = INTEGRAL_TYPE_P (final_type);
5088 int final_ptr = POINTER_TYPE_P (final_type);
5089 int final_float = FLOAT_TYPE_P (final_type);
5090 unsigned int final_prec = TYPE_PRECISION (final_type);
5091 int final_unsignedp = TREE_UNSIGNED (final_type);
5093 /* In addition to the cases of two conversions in a row
5094 handled below, if we are converting something to its own
5095 type via an object of identical or wider precision, neither
5096 conversion is needed. */
5097 if (inside_type == final_type
5098 && ((inter_int && final_int) || (inter_float && final_float))
5099 && inter_prec >= final_prec)
5100 return TREE_OPERAND (TREE_OPERAND (t, 0), 0);
5102 /* Likewise, if the intermediate and final types are either both
5103 float or both integer, we don't need the middle conversion if
5104 it is wider than the final type and doesn't change the signedness
5105 (for integers). Avoid this if the final type is a pointer
5106 since then we sometimes need the inner conversion. Likewise if
5107 the outer has a precision not equal to the size of its mode. */
5108 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
5109 || (inter_float && inside_float))
5110 && inter_prec >= inside_prec
5111 && (inter_float || inter_unsignedp == inside_unsignedp)
5112 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5113 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5115 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5117 /* If we have a sign-extension of a zero-extended value, we can
5118 replace that by a single zero-extension. */
5119 if (inside_int && inter_int && final_int
5120 && inside_prec < inter_prec && inter_prec < final_prec
5121 && inside_unsignedp && !inter_unsignedp)
5122 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5124 /* Two conversions in a row are not needed unless:
5125 - some conversion is floating-point (overstrict for now), or
5126 - the intermediate type is narrower than both initial and
5128 - the intermediate type and innermost type differ in signedness,
5129 and the outermost type is wider than the intermediate, or
5130 - the initial type is a pointer type and the precisions of the
5131 intermediate and final types differ, or
5132 - the final type is a pointer type and the precisions of the
5133 initial and intermediate types differ. */
5134 if (! inside_float && ! inter_float && ! final_float
5135 && (inter_prec > inside_prec || inter_prec > final_prec)
5136 && ! (inside_int && inter_int
5137 && inter_unsignedp != inside_unsignedp
5138 && inter_prec < final_prec)
5139 && ((inter_unsignedp && inter_prec > inside_prec)
5140 == (final_unsignedp && final_prec > inter_prec))
5141 && ! (inside_ptr && inter_prec != final_prec)
5142 && ! (final_ptr && inside_prec != inter_prec)
5143 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5144 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5146 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5149 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5150 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5151 /* Detect assigning a bitfield. */
5152 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5153 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5155 /* Don't leave an assignment inside a conversion
5156 unless assigning a bitfield. */
5157 tree prev = TREE_OPERAND (t, 0);
5158 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5159 /* First do the assignment, then return converted constant. */
5160 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5166 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
5169 return fold_convert (t, arg0);
5171 #if 0 /* This loses on &"foo"[0]. */
5176 /* Fold an expression like: "foo"[2] */
5177 if (TREE_CODE (arg0) == STRING_CST
5178 && TREE_CODE (arg1) == INTEGER_CST
5179 && compare_tree_int (arg1, TREE_STRING_LENGTH (arg0)) < 0)
5181 t = build_int_2 (TREE_STRING_POINTER (arg0)[TREE_INT_CST_LOW (arg))], 0);
5182 TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (arg0));
5183 force_fit_type (t, 0);
5190 if (TREE_CODE (arg0) == CONSTRUCTOR)
5192 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5199 TREE_CONSTANT (t) = wins;
5205 if (TREE_CODE (arg0) == INTEGER_CST)
5207 unsigned HOST_WIDE_INT low;
5209 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5210 TREE_INT_CST_HIGH (arg0),
5212 t = build_int_2 (low, high);
5213 TREE_TYPE (t) = type;
5215 = (TREE_OVERFLOW (arg0)
5216 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
5217 TREE_CONSTANT_OVERFLOW (t)
5218 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5220 else if (TREE_CODE (arg0) == REAL_CST)
5221 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5223 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5224 return TREE_OPERAND (arg0, 0);
5226 /* Convert - (a - b) to (b - a) for non-floating-point. */
5227 else if (TREE_CODE (arg0) == MINUS_EXPR
5228 && (! FLOAT_TYPE_P (type) || flag_fast_math))
5229 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
5230 TREE_OPERAND (arg0, 0));
5237 if (TREE_CODE (arg0) == INTEGER_CST)
5239 if (! TREE_UNSIGNED (type)
5240 && TREE_INT_CST_HIGH (arg0) < 0)
5242 unsigned HOST_WIDE_INT low;
5244 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5245 TREE_INT_CST_HIGH (arg0),
5247 t = build_int_2 (low, high);
5248 TREE_TYPE (t) = type;
5250 = (TREE_OVERFLOW (arg0)
5251 | force_fit_type (t, overflow));
5252 TREE_CONSTANT_OVERFLOW (t)
5253 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5256 else if (TREE_CODE (arg0) == REAL_CST)
5258 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5259 t = build_real (type,
5260 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5263 else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR)
5264 return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
5268 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5269 return convert (type, arg0);
5270 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5271 return build (COMPLEX_EXPR, type,
5272 TREE_OPERAND (arg0, 0),
5273 negate_expr (TREE_OPERAND (arg0, 1)));
5274 else if (TREE_CODE (arg0) == COMPLEX_CST)
5275 return build_complex (type, TREE_OPERAND (arg0, 0),
5276 negate_expr (TREE_OPERAND (arg0, 1)));
5277 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5278 return fold (build (TREE_CODE (arg0), type,
5279 fold (build1 (CONJ_EXPR, type,
5280 TREE_OPERAND (arg0, 0))),
5281 fold (build1 (CONJ_EXPR,
5282 type, TREE_OPERAND (arg0, 1)))));
5283 else if (TREE_CODE (arg0) == CONJ_EXPR)
5284 return TREE_OPERAND (arg0, 0);
5290 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5291 ~ TREE_INT_CST_HIGH (arg0));
5292 TREE_TYPE (t) = type;
5293 force_fit_type (t, 0);
5294 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5295 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5297 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5298 return TREE_OPERAND (arg0, 0);
5302 /* A + (-B) -> A - B */
5303 if (TREE_CODE (arg1) == NEGATE_EXPR)
5304 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5305 /* (-A) + B -> B - A */
5306 if (TREE_CODE (arg0) == NEGATE_EXPR)
5307 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5308 else if (! FLOAT_TYPE_P (type))
5310 if (integer_zerop (arg1))
5311 return non_lvalue (convert (type, arg0));
5313 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5314 with a constant, and the two constants have no bits in common,
5315 we should treat this as a BIT_IOR_EXPR since this may produce more
5317 if (TREE_CODE (arg0) == BIT_AND_EXPR
5318 && TREE_CODE (arg1) == BIT_AND_EXPR
5319 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5320 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5321 && integer_zerop (const_binop (BIT_AND_EXPR,
5322 TREE_OPERAND (arg0, 1),
5323 TREE_OPERAND (arg1, 1), 0)))
5325 code = BIT_IOR_EXPR;
5329 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5330 (plus (plus (mult) (mult)) (foo)) so that we can
5331 take advantage of the factoring cases below. */
5332 if ((TREE_CODE (arg0) == PLUS_EXPR
5333 && TREE_CODE (arg1) == MULT_EXPR)
5334 || (TREE_CODE (arg1) == PLUS_EXPR
5335 && TREE_CODE (arg0) == MULT_EXPR))
5337 tree parg0, parg1, parg, marg;
5339 if (TREE_CODE (arg0) == PLUS_EXPR)
5340 parg = arg0, marg = arg1;
5342 parg = arg1, marg = arg0;
5343 parg0 = TREE_OPERAND (parg, 0);
5344 parg1 = TREE_OPERAND (parg, 1);
5348 if (TREE_CODE (parg0) == MULT_EXPR
5349 && TREE_CODE (parg1) != MULT_EXPR)
5350 return fold (build (PLUS_EXPR, type,
5351 fold (build (PLUS_EXPR, type, parg0, marg)),
5353 if (TREE_CODE (parg0) != MULT_EXPR
5354 && TREE_CODE (parg1) == MULT_EXPR)
5355 return fold (build (PLUS_EXPR, type,
5356 fold (build (PLUS_EXPR, type, parg1, marg)),
5360 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5362 tree arg00, arg01, arg10, arg11;
5363 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5365 /* (A * C) + (B * C) -> (A+B) * C.
5366 We are most concerned about the case where C is a constant,
5367 but other combinations show up during loop reduction. Since
5368 it is not difficult, try all four possibilities. */
5370 arg00 = TREE_OPERAND (arg0, 0);
5371 arg01 = TREE_OPERAND (arg0, 1);
5372 arg10 = TREE_OPERAND (arg1, 0);
5373 arg11 = TREE_OPERAND (arg1, 1);
5376 if (operand_equal_p (arg01, arg11, 0))
5377 same = arg01, alt0 = arg00, alt1 = arg10;
5378 else if (operand_equal_p (arg00, arg10, 0))
5379 same = arg00, alt0 = arg01, alt1 = arg11;
5380 else if (operand_equal_p (arg00, arg11, 0))
5381 same = arg00, alt0 = arg01, alt1 = arg10;
5382 else if (operand_equal_p (arg01, arg10, 0))
5383 same = arg01, alt0 = arg00, alt1 = arg11;
5385 /* No identical multiplicands; see if we can find a common
5386 power-of-two factor in non-power-of-two multiplies. This
5387 can help in multi-dimensional array access. */
5388 else if (TREE_CODE (arg01) == INTEGER_CST
5389 && TREE_CODE (arg11) == INTEGER_CST
5390 && TREE_INT_CST_HIGH (arg01) == 0
5391 && TREE_INT_CST_HIGH (arg11) == 0)
5393 HOST_WIDE_INT int01, int11, tmp;
5394 int01 = TREE_INT_CST_LOW (arg01);
5395 int11 = TREE_INT_CST_LOW (arg11);
5397 /* Move min of absolute values to int11. */
5398 if ((int01 >= 0 ? int01 : -int01)
5399 < (int11 >= 0 ? int11 : -int11))
5401 tmp = int01, int01 = int11, int11 = tmp;
5402 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5403 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5406 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5408 alt0 = fold (build (MULT_EXPR, type, arg00,
5409 build_int_2 (int01 / int11, 0)));
5416 return fold (build (MULT_EXPR, type,
5417 fold (build (PLUS_EXPR, type, alt0, alt1)),
5421 /* In IEEE floating point, x+0 may not equal x. */
5422 else if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5424 && real_zerop (arg1))
5425 return non_lvalue (convert (type, arg0));
5426 /* x+(-0) equals x, even for IEEE. */
5427 else if (TREE_CODE (arg1) == REAL_CST
5428 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
5429 return non_lvalue (convert (type, arg0));
5432 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5433 is a rotate of A by C1 bits. */
5434 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5435 is a rotate of A by B bits. */
5437 register enum tree_code code0, code1;
5438 code0 = TREE_CODE (arg0);
5439 code1 = TREE_CODE (arg1);
5440 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5441 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5442 && operand_equal_p (TREE_OPERAND (arg0, 0),
5443 TREE_OPERAND (arg1, 0), 0)
5444 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5446 register tree tree01, tree11;
5447 register enum tree_code code01, code11;
5449 tree01 = TREE_OPERAND (arg0, 1);
5450 tree11 = TREE_OPERAND (arg1, 1);
5451 STRIP_NOPS (tree01);
5452 STRIP_NOPS (tree11);
5453 code01 = TREE_CODE (tree01);
5454 code11 = TREE_CODE (tree11);
5455 if (code01 == INTEGER_CST
5456 && code11 == INTEGER_CST
5457 && TREE_INT_CST_HIGH (tree01) == 0
5458 && TREE_INT_CST_HIGH (tree11) == 0
5459 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5460 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5461 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5462 code0 == LSHIFT_EXPR ? tree01 : tree11);
5463 else if (code11 == MINUS_EXPR)
5465 tree tree110, tree111;
5466 tree110 = TREE_OPERAND (tree11, 0);
5467 tree111 = TREE_OPERAND (tree11, 1);
5468 STRIP_NOPS (tree110);
5469 STRIP_NOPS (tree111);
5470 if (TREE_CODE (tree110) == INTEGER_CST
5471 && 0 == compare_tree_int (tree110,
5473 (TREE_TYPE (TREE_OPERAND
5475 && operand_equal_p (tree01, tree111, 0))
5476 return build ((code0 == LSHIFT_EXPR
5479 type, TREE_OPERAND (arg0, 0), tree01);
5481 else if (code01 == MINUS_EXPR)
5483 tree tree010, tree011;
5484 tree010 = TREE_OPERAND (tree01, 0);
5485 tree011 = TREE_OPERAND (tree01, 1);
5486 STRIP_NOPS (tree010);
5487 STRIP_NOPS (tree011);
5488 if (TREE_CODE (tree010) == INTEGER_CST
5489 && 0 == compare_tree_int (tree010,
5491 (TREE_TYPE (TREE_OPERAND
5493 && operand_equal_p (tree11, tree011, 0))
5494 return build ((code0 != LSHIFT_EXPR
5497 type, TREE_OPERAND (arg0, 0), tree11);
5503 /* In most languages, can't associate operations on floats through
5504 parentheses. Rather than remember where the parentheses were, we
5505 don't associate floats at all. It shouldn't matter much. However,
5506 associating multiplications is only very slightly inaccurate, so do
5507 that if -ffast-math is specified. */
5510 && (! FLOAT_TYPE_P (type)
5511 || (flag_fast_math && code != MULT_EXPR)))
5513 tree var0, con0, lit0, var1, con1, lit1;
5515 /* Split both trees into variables, constants, and literals. Then
5516 associate each group together, the constants with literals,
5517 then the result with variables. This increases the chances of
5518 literals being recombined later and of generating relocatable
5519 expressions for the sum of a constant and literal. */
5520 var0 = split_tree (arg0, code, &con0, &lit0, 0);
5521 var1 = split_tree (arg1, code, &con1, &lit1, code == MINUS_EXPR);
5523 /* Only do something if we found more than two objects. Otherwise,
5524 nothing has changed and we risk infinite recursion. */
5525 if (2 < ((var0 != 0) + (var1 != 0) + (con0 != 0) + (con1 != 0)
5526 + (lit0 != 0) + (lit1 != 0)))
5528 var0 = associate_trees (var0, var1, code, type);
5529 con0 = associate_trees (con0, con1, code, type);
5530 lit0 = associate_trees (lit0, lit1, code, type);
5531 con0 = associate_trees (con0, lit0, code, type);
5532 return convert (type, associate_trees (var0, con0, code, type));
5537 #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
5538 if (TREE_CODE (arg1) == REAL_CST)
5540 #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
5542 t1 = const_binop (code, arg0, arg1, 0);
5543 if (t1 != NULL_TREE)
5545 /* The return value should always have
5546 the same type as the original expression. */
5547 if (TREE_TYPE (t1) != TREE_TYPE (t))
5548 t1 = convert (TREE_TYPE (t), t1);
5555 /* A - (-B) -> A + B */
5556 if (TREE_CODE (arg1) == NEGATE_EXPR)
5557 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5558 /* (-A) - CST -> (-CST) - A for floating point (what about ints ?) */
5559 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
5561 fold (build (MINUS_EXPR, type,
5562 build_real (TREE_TYPE (arg1),
5563 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1))),
5564 TREE_OPERAND (arg0, 0)));
5566 if (! FLOAT_TYPE_P (type))
5568 if (! wins && integer_zerop (arg0))
5569 return negate_expr (convert (type, arg1));
5570 if (integer_zerop (arg1))
5571 return non_lvalue (convert (type, arg0));
5573 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5574 about the case where C is a constant, just try one of the
5575 four possibilities. */
5577 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5578 && operand_equal_p (TREE_OPERAND (arg0, 1),
5579 TREE_OPERAND (arg1, 1), 0))
5580 return fold (build (MULT_EXPR, type,
5581 fold (build (MINUS_EXPR, type,
5582 TREE_OPERAND (arg0, 0),
5583 TREE_OPERAND (arg1, 0))),
5584 TREE_OPERAND (arg0, 1)));
5587 else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5590 /* Except with IEEE floating point, 0-x equals -x. */
5591 if (! wins && real_zerop (arg0))
5592 return negate_expr (convert (type, arg1));
5593 /* Except with IEEE floating point, x-0 equals x. */
5594 if (real_zerop (arg1))
5595 return non_lvalue (convert (type, arg0));
5598 /* Fold &x - &x. This can happen from &x.foo - &x.
5599 This is unsafe for certain floats even in non-IEEE formats.
5600 In IEEE, it is unsafe because it does wrong for NaNs.
5601 Also note that operand_equal_p is always false if an operand
5604 if ((! FLOAT_TYPE_P (type) || flag_fast_math)
5605 && operand_equal_p (arg0, arg1, 0))
5606 return convert (type, integer_zero_node);
5611 /* (-A) * (-B) -> A * B */
5612 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5613 return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
5614 TREE_OPERAND (arg1, 0)));
5616 if (! FLOAT_TYPE_P (type))
5618 if (integer_zerop (arg1))
5619 return omit_one_operand (type, arg1, arg0);
5620 if (integer_onep (arg1))
5621 return non_lvalue (convert (type, arg0));
5623 /* (a * (1 << b)) is (a << b) */
5624 if (TREE_CODE (arg1) == LSHIFT_EXPR
5625 && integer_onep (TREE_OPERAND (arg1, 0)))
5626 return fold (build (LSHIFT_EXPR, type, arg0,
5627 TREE_OPERAND (arg1, 1)));
5628 if (TREE_CODE (arg0) == LSHIFT_EXPR
5629 && integer_onep (TREE_OPERAND (arg0, 0)))
5630 return fold (build (LSHIFT_EXPR, type, arg1,
5631 TREE_OPERAND (arg0, 1)));
5633 if (TREE_CODE (arg1) == INTEGER_CST
5634 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5636 return convert (type, tem);
5641 /* x*0 is 0, except for IEEE floating point. */
5642 if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5644 && real_zerop (arg1))
5645 return omit_one_operand (type, arg1, arg0);
5646 /* In IEEE floating point, x*1 is not equivalent to x for snans.
5647 However, ANSI says we can drop signals,
5648 so we can do this anyway. */
5649 if (real_onep (arg1))
5650 return non_lvalue (convert (type, arg0));
5652 if (! wins && real_twop (arg1) && global_bindings_p () == 0
5653 && ! contains_placeholder_p (arg0))
5655 tree arg = save_expr (arg0);
5656 return build (PLUS_EXPR, type, arg, arg);
5663 if (integer_all_onesp (arg1))
5664 return omit_one_operand (type, arg1, arg0);
5665 if (integer_zerop (arg1))
5666 return non_lvalue (convert (type, arg0));
5667 t1 = distribute_bit_expr (code, type, arg0, arg1);
5668 if (t1 != NULL_TREE)
5671 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
5673 This results in more efficient code for machines without a NAND
5674 instruction. Combine will canonicalize to the first form
5675 which will allow use of NAND instructions provided by the
5676 backend if they exist. */
5677 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5678 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5680 return fold (build1 (BIT_NOT_EXPR, type,
5681 build (BIT_AND_EXPR, type,
5682 TREE_OPERAND (arg0, 0),
5683 TREE_OPERAND (arg1, 0))));
5686 /* See if this can be simplified into a rotate first. If that
5687 is unsuccessful continue in the association code. */
5691 if (integer_zerop (arg1))
5692 return non_lvalue (convert (type, arg0));
5693 if (integer_all_onesp (arg1))
5694 return fold (build1 (BIT_NOT_EXPR, type, arg0));
5696 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
5697 with a constant, and the two constants have no bits in common,
5698 we should treat this as a BIT_IOR_EXPR since this may produce more
5700 if (TREE_CODE (arg0) == BIT_AND_EXPR
5701 && TREE_CODE (arg1) == BIT_AND_EXPR
5702 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5703 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5704 && integer_zerop (const_binop (BIT_AND_EXPR,
5705 TREE_OPERAND (arg0, 1),
5706 TREE_OPERAND (arg1, 1), 0)))
5708 code = BIT_IOR_EXPR;
5712 /* See if this can be simplified into a rotate first. If that
5713 is unsuccessful continue in the association code. */
5718 if (integer_all_onesp (arg1))
5719 return non_lvalue (convert (type, arg0));
5720 if (integer_zerop (arg1))
5721 return omit_one_operand (type, arg1, arg0);
5722 t1 = distribute_bit_expr (code, type, arg0, arg1);
5723 if (t1 != NULL_TREE)
5725 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5726 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == NOP_EXPR
5727 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0))))
5730 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0)));
5732 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5733 && (~TREE_INT_CST_LOW (arg0)
5734 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5735 return build1 (NOP_EXPR, type, TREE_OPERAND (arg1, 0));
5737 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
5738 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5741 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
5743 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5744 && (~TREE_INT_CST_LOW (arg1)
5745 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5746 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
5749 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
5751 This results in more efficient code for machines without a NOR
5752 instruction. Combine will canonicalize to the first form
5753 which will allow use of NOR instructions provided by the
5754 backend if they exist. */
5755 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5756 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5758 return fold (build1 (BIT_NOT_EXPR, type,
5759 build (BIT_IOR_EXPR, type,
5760 TREE_OPERAND (arg0, 0),
5761 TREE_OPERAND (arg1, 0))));
5766 case BIT_ANDTC_EXPR:
5767 if (integer_all_onesp (arg0))
5768 return non_lvalue (convert (type, arg1));
5769 if (integer_zerop (arg0))
5770 return omit_one_operand (type, arg0, arg1);
5771 if (TREE_CODE (arg1) == INTEGER_CST)
5773 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
5774 code = BIT_AND_EXPR;
5780 /* In most cases, do nothing with a divide by zero. */
5781 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5782 #ifndef REAL_INFINITY
5783 if (TREE_CODE (arg1) == REAL_CST && real_zerop (arg1))
5786 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5788 /* (-A) / (-B) -> A / B */
5789 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5790 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
5791 TREE_OPERAND (arg1, 0)));
5793 /* In IEEE floating point, x/1 is not equivalent to x for snans.
5794 However, ANSI says we can drop signals, so we can do this anyway. */
5795 if (real_onep (arg1))
5796 return non_lvalue (convert (type, arg0));
5798 /* If ARG1 is a constant, we can convert this to a multiply by the
5799 reciprocal. This does not have the same rounding properties,
5800 so only do this if -ffast-math. We can actually always safely
5801 do it if ARG1 is a power of two, but it's hard to tell if it is
5802 or not in a portable manner. */
5803 if (TREE_CODE (arg1) == REAL_CST)
5806 && 0 != (tem = const_binop (code, build_real (type, dconst1),
5808 return fold (build (MULT_EXPR, type, arg0, tem));
5809 /* Find the reciprocal if optimizing and the result is exact. */
5813 r = TREE_REAL_CST (arg1);
5814 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
5816 tem = build_real (type, r);
5817 return fold (build (MULT_EXPR, type, arg0, tem));
5823 case TRUNC_DIV_EXPR:
5824 case ROUND_DIV_EXPR:
5825 case FLOOR_DIV_EXPR:
5827 case EXACT_DIV_EXPR:
5828 if (integer_onep (arg1))
5829 return non_lvalue (convert (type, arg0));
5830 if (integer_zerop (arg1))
5833 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
5834 operation, EXACT_DIV_EXPR.
5836 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
5837 At one time others generated faster code, it's not clear if they do
5838 after the last round to changes to the DIV code in expmed.c. */
5839 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
5840 && multiple_of_p (type, arg0, arg1))
5841 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
5843 if (TREE_CODE (arg1) == INTEGER_CST
5844 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5846 return convert (type, tem);
5851 case FLOOR_MOD_EXPR:
5852 case ROUND_MOD_EXPR:
5853 case TRUNC_MOD_EXPR:
5854 if (integer_onep (arg1))
5855 return omit_one_operand (type, integer_zero_node, arg0);
5856 if (integer_zerop (arg1))
5859 if (TREE_CODE (arg1) == INTEGER_CST
5860 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5862 return convert (type, tem);
5870 if (integer_zerop (arg1))
5871 return non_lvalue (convert (type, arg0));
5872 /* Since negative shift count is not well-defined,
5873 don't try to compute it in the compiler. */
5874 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
5876 /* Rewrite an LROTATE_EXPR by a constant into an
5877 RROTATE_EXPR by a new constant. */
5878 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
5880 TREE_SET_CODE (t, RROTATE_EXPR);
5881 code = RROTATE_EXPR;
5882 TREE_OPERAND (t, 1) = arg1
5885 convert (TREE_TYPE (arg1),
5886 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
5888 if (tree_int_cst_sgn (arg1) < 0)
5892 /* If we have a rotate of a bit operation with the rotate count and
5893 the second operand of the bit operation both constant,
5894 permute the two operations. */
5895 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5896 && (TREE_CODE (arg0) == BIT_AND_EXPR
5897 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
5898 || TREE_CODE (arg0) == BIT_IOR_EXPR
5899 || TREE_CODE (arg0) == BIT_XOR_EXPR)
5900 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5901 return fold (build (TREE_CODE (arg0), type,
5902 fold (build (code, type,
5903 TREE_OPERAND (arg0, 0), arg1)),
5904 fold (build (code, type,
5905 TREE_OPERAND (arg0, 1), arg1))));
5907 /* Two consecutive rotates adding up to the width of the mode can
5909 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5910 && TREE_CODE (arg0) == RROTATE_EXPR
5911 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5912 && TREE_INT_CST_HIGH (arg1) == 0
5913 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
5914 && ((TREE_INT_CST_LOW (arg1)
5915 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
5916 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
5917 return TREE_OPERAND (arg0, 0);
5922 if (operand_equal_p (arg0, arg1, 0))
5923 return omit_one_operand (type, arg0, arg1);
5924 if (INTEGRAL_TYPE_P (type)
5925 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
5926 return omit_one_operand (type, arg1, arg0);
5930 if (operand_equal_p (arg0, arg1, 0))
5931 return omit_one_operand (type, arg0, arg1);
5932 if (INTEGRAL_TYPE_P (type)
5933 && TYPE_MAX_VALUE (type)
5934 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
5935 return omit_one_operand (type, arg1, arg0);
5938 case TRUTH_NOT_EXPR:
5939 /* Note that the operand of this must be an int
5940 and its values must be 0 or 1.
5941 ("true" is a fixed value perhaps depending on the language,
5942 but we don't handle values other than 1 correctly yet.) */
5943 tem = invert_truthvalue (arg0);
5944 /* Avoid infinite recursion. */
5945 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
5947 return convert (type, tem);
5949 case TRUTH_ANDIF_EXPR:
5950 /* Note that the operands of this must be ints
5951 and their values must be 0 or 1.
5952 ("true" is a fixed value perhaps depending on the language.) */
5953 /* If first arg is constant zero, return it. */
5954 if (integer_zerop (arg0))
5955 return convert (type, arg0);
5956 case TRUTH_AND_EXPR:
5957 /* If either arg is constant true, drop it. */
5958 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5959 return non_lvalue (convert (type, arg1));
5960 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5961 return non_lvalue (convert (type, arg0));
5962 /* If second arg is constant zero, result is zero, but first arg
5963 must be evaluated. */
5964 if (integer_zerop (arg1))
5965 return omit_one_operand (type, arg1, arg0);
5966 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
5967 case will be handled here. */
5968 if (integer_zerop (arg0))
5969 return omit_one_operand (type, arg0, arg1);
5972 /* We only do these simplifications if we are optimizing. */
5976 /* Check for things like (A || B) && (A || C). We can convert this
5977 to A || (B && C). Note that either operator can be any of the four
5978 truth and/or operations and the transformation will still be
5979 valid. Also note that we only care about order for the
5980 ANDIF and ORIF operators. If B contains side effects, this
5981 might change the truth-value of A. */
5982 if (TREE_CODE (arg0) == TREE_CODE (arg1)
5983 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
5984 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
5985 || TREE_CODE (arg0) == TRUTH_AND_EXPR
5986 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
5987 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
5989 tree a00 = TREE_OPERAND (arg0, 0);
5990 tree a01 = TREE_OPERAND (arg0, 1);
5991 tree a10 = TREE_OPERAND (arg1, 0);
5992 tree a11 = TREE_OPERAND (arg1, 1);
5993 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
5994 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
5995 && (code == TRUTH_AND_EXPR
5996 || code == TRUTH_OR_EXPR));
5998 if (operand_equal_p (a00, a10, 0))
5999 return fold (build (TREE_CODE (arg0), type, a00,
6000 fold (build (code, type, a01, a11))));
6001 else if (commutative && operand_equal_p (a00, a11, 0))
6002 return fold (build (TREE_CODE (arg0), type, a00,
6003 fold (build (code, type, a01, a10))));
6004 else if (commutative && operand_equal_p (a01, a10, 0))
6005 return fold (build (TREE_CODE (arg0), type, a01,
6006 fold (build (code, type, a00, a11))));
6008 /* This case if tricky because we must either have commutative
6009 operators or else A10 must not have side-effects. */
6011 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
6012 && operand_equal_p (a01, a11, 0))
6013 return fold (build (TREE_CODE (arg0), type,
6014 fold (build (code, type, a00, a10)),
6018 /* See if we can build a range comparison. */
6019 if (0 != (tem = fold_range_test (t)))
6022 /* Check for the possibility of merging component references. If our
6023 lhs is another similar operation, try to merge its rhs with our
6024 rhs. Then try to merge our lhs and rhs. */
6025 if (TREE_CODE (arg0) == code
6026 && 0 != (tem = fold_truthop (code, type,
6027 TREE_OPERAND (arg0, 1), arg1)))
6028 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6030 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
6035 case TRUTH_ORIF_EXPR:
6036 /* Note that the operands of this must be ints
6037 and their values must be 0 or true.
6038 ("true" is a fixed value perhaps depending on the language.) */
6039 /* If first arg is constant true, return it. */
6040 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6041 return convert (type, arg0);
6043 /* If either arg is constant zero, drop it. */
6044 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
6045 return non_lvalue (convert (type, arg1));
6046 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1))
6047 return non_lvalue (convert (type, arg0));
6048 /* If second arg is constant true, result is true, but we must
6049 evaluate first arg. */
6050 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
6051 return omit_one_operand (type, arg1, arg0);
6052 /* Likewise for first arg, but note this only occurs here for
6054 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6055 return omit_one_operand (type, arg0, arg1);
6058 case TRUTH_XOR_EXPR:
6059 /* If either arg is constant zero, drop it. */
6060 if (integer_zerop (arg0))
6061 return non_lvalue (convert (type, arg1));
6062 if (integer_zerop (arg1))
6063 return non_lvalue (convert (type, arg0));
6064 /* If either arg is constant true, this is a logical inversion. */
6065 if (integer_onep (arg0))
6066 return non_lvalue (convert (type, invert_truthvalue (arg1)));
6067 if (integer_onep (arg1))
6068 return non_lvalue (convert (type, invert_truthvalue (arg0)));
6077 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
6079 /* (-a) CMP (-b) -> b CMP a */
6080 if (TREE_CODE (arg0) == NEGATE_EXPR
6081 && TREE_CODE (arg1) == NEGATE_EXPR)
6082 return fold (build (code, type, TREE_OPERAND (arg1, 0),
6083 TREE_OPERAND (arg0, 0)));
6084 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6085 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
6088 (swap_tree_comparison (code), type,
6089 TREE_OPERAND (arg0, 0),
6090 build_real (TREE_TYPE (arg1),
6091 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1)))));
6092 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6093 /* a CMP (-0) -> a CMP 0 */
6094 if (TREE_CODE (arg1) == REAL_CST
6095 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
6096 return fold (build (code, type, arg0,
6097 build_real (TREE_TYPE (arg1), dconst0)));
6100 /* If one arg is a constant integer, put it last. */
6101 if (TREE_CODE (arg0) == INTEGER_CST
6102 && TREE_CODE (arg1) != INTEGER_CST)
6104 TREE_OPERAND (t, 0) = arg1;
6105 TREE_OPERAND (t, 1) = arg0;
6106 arg0 = TREE_OPERAND (t, 0);
6107 arg1 = TREE_OPERAND (t, 1);
6108 code = swap_tree_comparison (code);
6109 TREE_SET_CODE (t, code);
6112 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6113 First, see if one arg is constant; find the constant arg
6114 and the other one. */
6116 tree constop = 0, varop = NULL_TREE;
6117 int constopnum = -1;
6119 if (TREE_CONSTANT (arg1))
6120 constopnum = 1, constop = arg1, varop = arg0;
6121 if (TREE_CONSTANT (arg0))
6122 constopnum = 0, constop = arg0, varop = arg1;
6124 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
6126 /* This optimization is invalid for ordered comparisons
6127 if CONST+INCR overflows or if foo+incr might overflow.
6128 This optimization is invalid for floating point due to rounding.
6129 For pointer types we assume overflow doesn't happen. */
6130 if (POINTER_TYPE_P (TREE_TYPE (varop))
6131 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6132 && (code == EQ_EXPR || code == NE_EXPR)))
6135 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
6136 constop, TREE_OPERAND (varop, 1)));
6138 /* Do not overwrite the current varop to be a preincrement,
6139 create a new node so that we won't confuse our caller who
6140 might create trees and throw them away, reusing the
6141 arguments that they passed to build. This shows up in
6142 the THEN or ELSE parts of ?: being postincrements. */
6143 varop = build (PREINCREMENT_EXPR, TREE_TYPE (varop),
6144 TREE_OPERAND (varop, 0),
6145 TREE_OPERAND (varop, 1));
6147 /* If VAROP is a reference to a bitfield, we must mask
6148 the constant by the width of the field. */
6149 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6150 && DECL_BIT_FIELD(TREE_OPERAND
6151 (TREE_OPERAND (varop, 0), 1)))
6154 = TREE_INT_CST_LOW (DECL_SIZE
6156 (TREE_OPERAND (varop, 0), 1)));
6157 tree mask, unsigned_type;
6158 unsigned int precision;
6159 tree folded_compare;
6161 /* First check whether the comparison would come out
6162 always the same. If we don't do that we would
6163 change the meaning with the masking. */
6164 if (constopnum == 0)
6165 folded_compare = fold (build (code, type, constop,
6166 TREE_OPERAND (varop, 0)));
6168 folded_compare = fold (build (code, type,
6169 TREE_OPERAND (varop, 0),
6171 if (integer_zerop (folded_compare)
6172 || integer_onep (folded_compare))
6173 return omit_one_operand (type, folded_compare, varop);
6175 unsigned_type = type_for_size (size, 1);
6176 precision = TYPE_PRECISION (unsigned_type);
6177 mask = build_int_2 (~0, ~0);
6178 TREE_TYPE (mask) = unsigned_type;
6179 force_fit_type (mask, 0);
6180 mask = const_binop (RSHIFT_EXPR, mask,
6181 size_int (precision - size), 0);
6182 newconst = fold (build (BIT_AND_EXPR,
6183 TREE_TYPE (varop), newconst,
6184 convert (TREE_TYPE (varop),
6188 t = build (code, type,
6189 (constopnum == 0) ? newconst : varop,
6190 (constopnum == 1) ? newconst : varop);
6194 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
6196 if (POINTER_TYPE_P (TREE_TYPE (varop))
6197 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6198 && (code == EQ_EXPR || code == NE_EXPR)))
6201 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
6202 constop, TREE_OPERAND (varop, 1)));
6204 /* Do not overwrite the current varop to be a predecrement,
6205 create a new node so that we won't confuse our caller who
6206 might create trees and throw them away, reusing the
6207 arguments that they passed to build. This shows up in
6208 the THEN or ELSE parts of ?: being postdecrements. */
6209 varop = build (PREDECREMENT_EXPR, TREE_TYPE (varop),
6210 TREE_OPERAND (varop, 0),
6211 TREE_OPERAND (varop, 1));
6213 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6214 && DECL_BIT_FIELD(TREE_OPERAND
6215 (TREE_OPERAND (varop, 0), 1)))
6218 = TREE_INT_CST_LOW (DECL_SIZE
6220 (TREE_OPERAND (varop, 0), 1)));
6221 tree mask, unsigned_type;
6222 unsigned int precision;
6223 tree folded_compare;
6225 if (constopnum == 0)
6226 folded_compare = fold (build (code, type, constop,
6227 TREE_OPERAND (varop, 0)));
6229 folded_compare = fold (build (code, type,
6230 TREE_OPERAND (varop, 0),
6232 if (integer_zerop (folded_compare)
6233 || integer_onep (folded_compare))
6234 return omit_one_operand (type, folded_compare, varop);
6236 unsigned_type = type_for_size (size, 1);
6237 precision = TYPE_PRECISION (unsigned_type);
6238 mask = build_int_2 (~0, ~0);
6239 TREE_TYPE (mask) = TREE_TYPE (varop);
6240 force_fit_type (mask, 0);
6241 mask = const_binop (RSHIFT_EXPR, mask,
6242 size_int (precision - size), 0);
6243 newconst = fold (build (BIT_AND_EXPR,
6244 TREE_TYPE (varop), newconst,
6245 convert (TREE_TYPE (varop),
6249 t = build (code, type,
6250 (constopnum == 0) ? newconst : varop,
6251 (constopnum == 1) ? newconst : varop);
6257 /* Change X >= CST to X > (CST - 1) if CST is positive. */
6258 if (TREE_CODE (arg1) == INTEGER_CST
6259 && TREE_CODE (arg0) != INTEGER_CST
6260 && tree_int_cst_sgn (arg1) > 0)
6262 switch (TREE_CODE (t))
6266 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6267 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6272 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6273 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6281 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6282 a MINUS_EXPR of a constant, we can convert it into a comparison with
6283 a revised constant as long as no overflow occurs. */
6284 if ((code == EQ_EXPR || code == NE_EXPR)
6285 && TREE_CODE (arg1) == INTEGER_CST
6286 && (TREE_CODE (arg0) == PLUS_EXPR
6287 || TREE_CODE (arg0) == MINUS_EXPR)
6288 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6289 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6290 ? MINUS_EXPR : PLUS_EXPR,
6291 arg1, TREE_OPERAND (arg0, 1), 0))
6292 && ! TREE_CONSTANT_OVERFLOW (tem))
6293 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6295 /* Similarly for a NEGATE_EXPR. */
6296 else if ((code == EQ_EXPR || code == NE_EXPR)
6297 && TREE_CODE (arg0) == NEGATE_EXPR
6298 && TREE_CODE (arg1) == INTEGER_CST
6299 && 0 != (tem = negate_expr (arg1))
6300 && TREE_CODE (tem) == INTEGER_CST
6301 && ! TREE_CONSTANT_OVERFLOW (tem))
6302 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6304 /* If we have X - Y == 0, we can convert that to X == Y and similarly
6305 for !=. Don't do this for ordered comparisons due to overflow. */
6306 else if ((code == NE_EXPR || code == EQ_EXPR)
6307 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
6308 return fold (build (code, type,
6309 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
6311 /* If we are widening one operand of an integer comparison,
6312 see if the other operand is similarly being widened. Perhaps we
6313 can do the comparison in the narrower type. */
6314 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
6315 && TREE_CODE (arg0) == NOP_EXPR
6316 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
6317 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
6318 && (TREE_TYPE (t1) == TREE_TYPE (tem)
6319 || (TREE_CODE (t1) == INTEGER_CST
6320 && int_fits_type_p (t1, TREE_TYPE (tem)))))
6321 return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
6323 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
6324 constant, we can simplify it. */
6325 else if (TREE_CODE (arg1) == INTEGER_CST
6326 && (TREE_CODE (arg0) == MIN_EXPR
6327 || TREE_CODE (arg0) == MAX_EXPR)
6328 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6329 return optimize_minmax_comparison (t);
6331 /* If we are comparing an ABS_EXPR with a constant, we can
6332 convert all the cases into explicit comparisons, but they may
6333 well not be faster than doing the ABS and one comparison.
6334 But ABS (X) <= C is a range comparison, which becomes a subtraction
6335 and a comparison, and is probably faster. */
6336 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6337 && TREE_CODE (arg0) == ABS_EXPR
6338 && ! TREE_SIDE_EFFECTS (arg0)
6339 && (0 != (tem = negate_expr (arg1)))
6340 && TREE_CODE (tem) == INTEGER_CST
6341 && ! TREE_CONSTANT_OVERFLOW (tem))
6342 return fold (build (TRUTH_ANDIF_EXPR, type,
6343 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
6344 build (LE_EXPR, type,
6345 TREE_OPERAND (arg0, 0), arg1)));
6347 /* If this is an EQ or NE comparison with zero and ARG0 is
6348 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
6349 two operations, but the latter can be done in one less insn
6350 on machines that have only two-operand insns or on which a
6351 constant cannot be the first operand. */
6352 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
6353 && TREE_CODE (arg0) == BIT_AND_EXPR)
6355 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
6356 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
6358 fold (build (code, type,
6359 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6361 TREE_TYPE (TREE_OPERAND (arg0, 0)),
6362 TREE_OPERAND (arg0, 1),
6363 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
6364 convert (TREE_TYPE (arg0),
6367 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
6368 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
6370 fold (build (code, type,
6371 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6373 TREE_TYPE (TREE_OPERAND (arg0, 1)),
6374 TREE_OPERAND (arg0, 0),
6375 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
6376 convert (TREE_TYPE (arg0),
6381 /* If this is an NE or EQ comparison of zero against the result of a
6382 signed MOD operation whose second operand is a power of 2, make
6383 the MOD operation unsigned since it is simpler and equivalent. */
6384 if ((code == NE_EXPR || code == EQ_EXPR)
6385 && integer_zerop (arg1)
6386 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
6387 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
6388 || TREE_CODE (arg0) == CEIL_MOD_EXPR
6389 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
6390 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
6391 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6393 tree newtype = unsigned_type (TREE_TYPE (arg0));
6394 tree newmod = build (TREE_CODE (arg0), newtype,
6395 convert (newtype, TREE_OPERAND (arg0, 0)),
6396 convert (newtype, TREE_OPERAND (arg0, 1)));
6398 return build (code, type, newmod, convert (newtype, arg1));
6401 /* If this is an NE comparison of zero with an AND of one, remove the
6402 comparison since the AND will give the correct value. */
6403 if (code == NE_EXPR && integer_zerop (arg1)
6404 && TREE_CODE (arg0) == BIT_AND_EXPR
6405 && integer_onep (TREE_OPERAND (arg0, 1)))
6406 return convert (type, arg0);
6408 /* If we have (A & C) == C where C is a power of 2, convert this into
6409 (A & C) != 0. Similarly for NE_EXPR. */
6410 if ((code == EQ_EXPR || code == NE_EXPR)
6411 && TREE_CODE (arg0) == BIT_AND_EXPR
6412 && integer_pow2p (TREE_OPERAND (arg0, 1))
6413 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
6414 return build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
6415 arg0, integer_zero_node);
6417 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
6418 and similarly for >= into !=. */
6419 if ((code == LT_EXPR || code == GE_EXPR)
6420 && TREE_UNSIGNED (TREE_TYPE (arg0))
6421 && TREE_CODE (arg1) == LSHIFT_EXPR
6422 && integer_onep (TREE_OPERAND (arg1, 0)))
6423 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6424 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6425 TREE_OPERAND (arg1, 1)),
6426 convert (TREE_TYPE (arg0), integer_zero_node));
6428 else if ((code == LT_EXPR || code == GE_EXPR)
6429 && TREE_UNSIGNED (TREE_TYPE (arg0))
6430 && (TREE_CODE (arg1) == NOP_EXPR
6431 || TREE_CODE (arg1) == CONVERT_EXPR)
6432 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
6433 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
6435 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6436 convert (TREE_TYPE (arg0),
6437 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6438 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
6439 convert (TREE_TYPE (arg0), integer_zero_node));
6441 /* Simplify comparison of something with itself. (For IEEE
6442 floating-point, we can only do some of these simplifications.) */
6443 if (operand_equal_p (arg0, arg1, 0))
6450 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
6451 return constant_boolean_node (1, type);
6453 TREE_SET_CODE (t, code);
6457 /* For NE, we can only do this simplification if integer. */
6458 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
6460 /* ... fall through ... */
6463 return constant_boolean_node (0, type);
6469 /* An unsigned comparison against 0 can be simplified. */
6470 if (integer_zerop (arg1)
6471 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6472 || POINTER_TYPE_P (TREE_TYPE (arg1)))
6473 && TREE_UNSIGNED (TREE_TYPE (arg1)))
6475 switch (TREE_CODE (t))
6479 TREE_SET_CODE (t, NE_EXPR);
6483 TREE_SET_CODE (t, EQ_EXPR);
6486 return omit_one_operand (type,
6487 convert (type, integer_one_node),
6490 return omit_one_operand (type,
6491 convert (type, integer_zero_node),
6498 /* Comparisons with the highest or lowest possible integer of
6499 the specified size will have known values and an unsigned
6500 <= 0x7fffffff can be simplified. */
6502 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
6504 if (TREE_CODE (arg1) == INTEGER_CST
6505 && ! TREE_CONSTANT_OVERFLOW (arg1)
6506 && width <= HOST_BITS_PER_WIDE_INT
6507 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6508 || POINTER_TYPE_P (TREE_TYPE (arg1))))
6510 if (TREE_INT_CST_HIGH (arg1) == 0
6511 && (TREE_INT_CST_LOW (arg1)
6512 == ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1)
6513 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6514 switch (TREE_CODE (t))
6517 return omit_one_operand (type,
6518 convert (type, integer_zero_node),
6521 TREE_SET_CODE (t, EQ_EXPR);
6525 return omit_one_operand (type,
6526 convert (type, integer_one_node),
6529 TREE_SET_CODE (t, NE_EXPR);
6536 else if (TREE_INT_CST_HIGH (arg1) == -1
6537 && (- TREE_INT_CST_LOW (arg1)
6538 == ((unsigned HOST_WIDE_INT) 1 << (width - 1)))
6539 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6540 switch (TREE_CODE (t))
6543 return omit_one_operand (type,
6544 convert (type, integer_zero_node),
6547 TREE_SET_CODE (t, EQ_EXPR);
6551 return omit_one_operand (type,
6552 convert (type, integer_one_node),
6555 TREE_SET_CODE (t, NE_EXPR);
6562 else if (TREE_INT_CST_HIGH (arg1) == 0
6563 && (TREE_INT_CST_LOW (arg1)
6564 == ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1)
6565 && TREE_UNSIGNED (TREE_TYPE (arg1)))
6567 switch (TREE_CODE (t))
6570 return fold (build (GE_EXPR, type,
6571 convert (signed_type (TREE_TYPE (arg0)),
6573 convert (signed_type (TREE_TYPE (arg1)),
6574 integer_zero_node)));
6576 return fold (build (LT_EXPR, type,
6577 convert (signed_type (TREE_TYPE (arg0)),
6579 convert (signed_type (TREE_TYPE (arg1)),
6580 integer_zero_node)));
6588 /* If we are comparing an expression that just has comparisons
6589 of two integer values, arithmetic expressions of those comparisons,
6590 and constants, we can simplify it. There are only three cases
6591 to check: the two values can either be equal, the first can be
6592 greater, or the second can be greater. Fold the expression for
6593 those three values. Since each value must be 0 or 1, we have
6594 eight possibilities, each of which corresponds to the constant 0
6595 or 1 or one of the six possible comparisons.
6597 This handles common cases like (a > b) == 0 but also handles
6598 expressions like ((x > y) - (y > x)) > 0, which supposedly
6599 occur in macroized code. */
6601 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
6603 tree cval1 = 0, cval2 = 0;
6606 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
6607 /* Don't handle degenerate cases here; they should already
6608 have been handled anyway. */
6609 && cval1 != 0 && cval2 != 0
6610 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
6611 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
6612 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
6613 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
6614 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
6615 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
6616 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
6618 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
6619 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
6621 /* We can't just pass T to eval_subst in case cval1 or cval2
6622 was the same as ARG1. */
6625 = fold (build (code, type,
6626 eval_subst (arg0, cval1, maxval, cval2, minval),
6629 = fold (build (code, type,
6630 eval_subst (arg0, cval1, maxval, cval2, maxval),
6633 = fold (build (code, type,
6634 eval_subst (arg0, cval1, minval, cval2, maxval),
6637 /* All three of these results should be 0 or 1. Confirm they
6638 are. Then use those values to select the proper code
6641 if ((integer_zerop (high_result)
6642 || integer_onep (high_result))
6643 && (integer_zerop (equal_result)
6644 || integer_onep (equal_result))
6645 && (integer_zerop (low_result)
6646 || integer_onep (low_result)))
6648 /* Make a 3-bit mask with the high-order bit being the
6649 value for `>', the next for '=', and the low for '<'. */
6650 switch ((integer_onep (high_result) * 4)
6651 + (integer_onep (equal_result) * 2)
6652 + integer_onep (low_result))
6656 return omit_one_operand (type, integer_zero_node, arg0);
6677 return omit_one_operand (type, integer_one_node, arg0);
6680 t = build (code, type, cval1, cval2);
6682 return save_expr (t);
6689 /* If this is a comparison of a field, we may be able to simplify it. */
6690 if ((TREE_CODE (arg0) == COMPONENT_REF
6691 || TREE_CODE (arg0) == BIT_FIELD_REF)
6692 && (code == EQ_EXPR || code == NE_EXPR)
6693 /* Handle the constant case even without -O
6694 to make sure the warnings are given. */
6695 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
6697 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
6701 /* If this is a comparison of complex values and either or both sides
6702 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6703 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6704 This may prevent needless evaluations. */
6705 if ((code == EQ_EXPR || code == NE_EXPR)
6706 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
6707 && (TREE_CODE (arg0) == COMPLEX_EXPR
6708 || TREE_CODE (arg1) == COMPLEX_EXPR
6709 || TREE_CODE (arg0) == COMPLEX_CST
6710 || TREE_CODE (arg1) == COMPLEX_CST))
6712 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
6713 tree real0, imag0, real1, imag1;
6715 arg0 = save_expr (arg0);
6716 arg1 = save_expr (arg1);
6717 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
6718 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
6719 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
6720 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
6722 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
6725 fold (build (code, type, real0, real1)),
6726 fold (build (code, type, imag0, imag1))));
6729 /* From here on, the only cases we handle are when the result is
6730 known to be a constant.
6732 To compute GT, swap the arguments and do LT.
6733 To compute GE, do LT and invert the result.
6734 To compute LE, swap the arguments, do LT and invert the result.
6735 To compute NE, do EQ and invert the result.
6737 Therefore, the code below must handle only EQ and LT. */
6739 if (code == LE_EXPR || code == GT_EXPR)
6741 tem = arg0, arg0 = arg1, arg1 = tem;
6742 code = swap_tree_comparison (code);
6745 /* Note that it is safe to invert for real values here because we
6746 will check below in the one case that it matters. */
6750 if (code == NE_EXPR || code == GE_EXPR)
6753 code = invert_tree_comparison (code);
6756 /* Compute a result for LT or EQ if args permit;
6757 otherwise return T. */
6758 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
6760 if (code == EQ_EXPR)
6761 t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0);
6763 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
6764 ? INT_CST_LT_UNSIGNED (arg0, arg1)
6765 : INT_CST_LT (arg0, arg1)),
6769 #if 0 /* This is no longer useful, but breaks some real code. */
6770 /* Assume a nonexplicit constant cannot equal an explicit one,
6771 since such code would be undefined anyway.
6772 Exception: on sysvr4, using #pragma weak,
6773 a label can come out as 0. */
6774 else if (TREE_CODE (arg1) == INTEGER_CST
6775 && !integer_zerop (arg1)
6776 && TREE_CONSTANT (arg0)
6777 && TREE_CODE (arg0) == ADDR_EXPR
6779 t1 = build_int_2 (0, 0);
6781 /* Two real constants can be compared explicitly. */
6782 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
6784 /* If either operand is a NaN, the result is false with two
6785 exceptions: First, an NE_EXPR is true on NaNs, but that case
6786 is already handled correctly since we will be inverting the
6787 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6788 or a GE_EXPR into a LT_EXPR, we must return true so that it
6789 will be inverted into false. */
6791 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
6792 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
6793 t1 = build_int_2 (invert && code == LT_EXPR, 0);
6795 else if (code == EQ_EXPR)
6796 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
6797 TREE_REAL_CST (arg1)),
6800 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
6801 TREE_REAL_CST (arg1)),
6805 if (t1 == NULL_TREE)
6809 TREE_INT_CST_LOW (t1) ^= 1;
6811 TREE_TYPE (t1) = type;
6812 if (TREE_CODE (type) == BOOLEAN_TYPE)
6813 return truthvalue_conversion (t1);
6817 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
6818 so all simple results must be passed through pedantic_non_lvalue. */
6819 if (TREE_CODE (arg0) == INTEGER_CST)
6820 return pedantic_non_lvalue
6821 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
6822 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
6823 return pedantic_omit_one_operand (type, arg1, arg0);
6825 /* If the second operand is zero, invert the comparison and swap
6826 the second and third operands. Likewise if the second operand
6827 is constant and the third is not or if the third operand is
6828 equivalent to the first operand of the comparison. */
6830 if (integer_zerop (arg1)
6831 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
6832 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6833 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6834 TREE_OPERAND (t, 2),
6835 TREE_OPERAND (arg0, 1))))
6837 /* See if this can be inverted. If it can't, possibly because
6838 it was a floating-point inequality comparison, don't do
6840 tem = invert_truthvalue (arg0);
6842 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6844 t = build (code, type, tem,
6845 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6847 /* arg1 should be the first argument of the new T. */
6848 arg1 = TREE_OPERAND (t, 1);
6853 /* If we have A op B ? A : C, we may be able to convert this to a
6854 simpler expression, depending on the operation and the values
6855 of B and C. IEEE floating point prevents this though,
6856 because A or B might be -0.0 or a NaN. */
6858 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6859 && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
6860 || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0)))
6862 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6863 arg1, TREE_OPERAND (arg0, 1)))
6865 tree arg2 = TREE_OPERAND (t, 2);
6866 enum tree_code comp_code = TREE_CODE (arg0);
6870 /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
6871 depending on the comparison operation. */
6872 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
6873 ? real_zerop (TREE_OPERAND (arg0, 1))
6874 : integer_zerop (TREE_OPERAND (arg0, 1)))
6875 && TREE_CODE (arg2) == NEGATE_EXPR
6876 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
6884 (convert (TREE_TYPE (TREE_OPERAND (t, 1)),
6888 return pedantic_non_lvalue (convert (type, arg1));
6891 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6892 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6893 return pedantic_non_lvalue
6894 (convert (type, fold (build1 (ABS_EXPR,
6895 TREE_TYPE (arg1), arg1))));
6898 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6899 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6900 return pedantic_non_lvalue
6901 (negate_expr (convert (type,
6902 fold (build1 (ABS_EXPR,
6909 /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
6912 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
6914 if (comp_code == NE_EXPR)
6915 return pedantic_non_lvalue (convert (type, arg1));
6916 else if (comp_code == EQ_EXPR)
6917 return pedantic_non_lvalue (convert (type, integer_zero_node));
6920 /* If this is A op B ? A : B, this is either A, B, min (A, B),
6921 or max (A, B), depending on the operation. */
6923 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
6924 arg2, TREE_OPERAND (arg0, 0)))
6926 tree comp_op0 = TREE_OPERAND (arg0, 0);
6927 tree comp_op1 = TREE_OPERAND (arg0, 1);
6928 tree comp_type = TREE_TYPE (comp_op0);
6930 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
6931 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
6937 return pedantic_non_lvalue (convert (type, arg2));
6939 return pedantic_non_lvalue (convert (type, arg1));
6942 /* In C++ a ?: expression can be an lvalue, so put the
6943 operand which will be used if they are equal first
6944 so that we can convert this back to the
6945 corresponding COND_EXPR. */
6946 return pedantic_non_lvalue
6947 (convert (type, fold (build (MIN_EXPR, comp_type,
6948 (comp_code == LE_EXPR
6949 ? comp_op0 : comp_op1),
6950 (comp_code == LE_EXPR
6951 ? comp_op1 : comp_op0)))));
6955 return pedantic_non_lvalue
6956 (convert (type, fold (build (MAX_EXPR, comp_type,
6957 (comp_code == GE_EXPR
6958 ? comp_op0 : comp_op1),
6959 (comp_code == GE_EXPR
6960 ? comp_op1 : comp_op0)))));
6967 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
6968 we might still be able to simplify this. For example,
6969 if C1 is one less or one more than C2, this might have started
6970 out as a MIN or MAX and been transformed by this function.
6971 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
6973 if (INTEGRAL_TYPE_P (type)
6974 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6975 && TREE_CODE (arg2) == INTEGER_CST)
6979 /* We can replace A with C1 in this case. */
6980 arg1 = convert (type, TREE_OPERAND (arg0, 1));
6981 t = build (code, type, TREE_OPERAND (t, 0), arg1,
6982 TREE_OPERAND (t, 2));
6986 /* If C1 is C2 + 1, this is min(A, C2). */
6987 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6988 && operand_equal_p (TREE_OPERAND (arg0, 1),
6989 const_binop (PLUS_EXPR, arg2,
6990 integer_one_node, 0), 1))
6991 return pedantic_non_lvalue
6992 (fold (build (MIN_EXPR, type, arg1, arg2)));
6996 /* If C1 is C2 - 1, this is min(A, C2). */
6997 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6998 && operand_equal_p (TREE_OPERAND (arg0, 1),
6999 const_binop (MINUS_EXPR, arg2,
7000 integer_one_node, 0), 1))
7001 return pedantic_non_lvalue
7002 (fold (build (MIN_EXPR, type, arg1, arg2)));
7006 /* If C1 is C2 - 1, this is max(A, C2). */
7007 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7008 && operand_equal_p (TREE_OPERAND (arg0, 1),
7009 const_binop (MINUS_EXPR, arg2,
7010 integer_one_node, 0), 1))
7011 return pedantic_non_lvalue
7012 (fold (build (MAX_EXPR, type, arg1, arg2)));
7016 /* If C1 is C2 + 1, this is max(A, C2). */
7017 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7018 && operand_equal_p (TREE_OPERAND (arg0, 1),
7019 const_binop (PLUS_EXPR, arg2,
7020 integer_one_node, 0), 1))
7021 return pedantic_non_lvalue
7022 (fold (build (MAX_EXPR, type, arg1, arg2)));
7031 /* If the second operand is simpler than the third, swap them
7032 since that produces better jump optimization results. */
7033 if ((TREE_CONSTANT (arg1) || DECL_P (arg1)
7034 || TREE_CODE (arg1) == SAVE_EXPR)
7035 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
7036 || DECL_P (TREE_OPERAND (t, 2))
7037 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
7039 /* See if this can be inverted. If it can't, possibly because
7040 it was a floating-point inequality comparison, don't do
7042 tem = invert_truthvalue (arg0);
7044 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7046 t = build (code, type, tem,
7047 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7049 /* arg1 should be the first argument of the new T. */
7050 arg1 = TREE_OPERAND (t, 1);
7055 /* Convert A ? 1 : 0 to simply A. */
7056 if (integer_onep (TREE_OPERAND (t, 1))
7057 && integer_zerop (TREE_OPERAND (t, 2))
7058 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7059 call to fold will try to move the conversion inside
7060 a COND, which will recurse. In that case, the COND_EXPR
7061 is probably the best choice, so leave it alone. */
7062 && type == TREE_TYPE (arg0))
7063 return pedantic_non_lvalue (arg0);
7065 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7066 operation is simply A & 2. */
7068 if (integer_zerop (TREE_OPERAND (t, 2))
7069 && TREE_CODE (arg0) == NE_EXPR
7070 && integer_zerop (TREE_OPERAND (arg0, 1))
7071 && integer_pow2p (arg1)
7072 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
7073 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
7075 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
7080 /* When pedantic, a compound expression can be neither an lvalue
7081 nor an integer constant expression. */
7082 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
7084 /* Don't let (0, 0) be null pointer constant. */
7085 if (integer_zerop (arg1))
7086 return build1 (NOP_EXPR, type, arg1);
7087 return convert (type, arg1);
7091 return build_complex (type, arg0, arg1);
7095 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7097 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7098 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7099 TREE_OPERAND (arg0, 1));
7100 else if (TREE_CODE (arg0) == COMPLEX_CST)
7101 return TREE_REALPART (arg0);
7102 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7103 return fold (build (TREE_CODE (arg0), type,
7104 fold (build1 (REALPART_EXPR, type,
7105 TREE_OPERAND (arg0, 0))),
7106 fold (build1 (REALPART_EXPR,
7107 type, TREE_OPERAND (arg0, 1)))));
7111 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7112 return convert (type, integer_zero_node);
7113 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7114 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7115 TREE_OPERAND (arg0, 0));
7116 else if (TREE_CODE (arg0) == COMPLEX_CST)
7117 return TREE_IMAGPART (arg0);
7118 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7119 return fold (build (TREE_CODE (arg0), type,
7120 fold (build1 (IMAGPART_EXPR, type,
7121 TREE_OPERAND (arg0, 0))),
7122 fold (build1 (IMAGPART_EXPR, type,
7123 TREE_OPERAND (arg0, 1)))));
7126 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7128 case CLEANUP_POINT_EXPR:
7129 if (! has_cleanups (arg0))
7130 return TREE_OPERAND (t, 0);
7133 enum tree_code code0 = TREE_CODE (arg0);
7134 int kind0 = TREE_CODE_CLASS (code0);
7135 tree arg00 = TREE_OPERAND (arg0, 0);
7138 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
7139 return fold (build1 (code0, type,
7140 fold (build1 (CLEANUP_POINT_EXPR,
7141 TREE_TYPE (arg00), arg00))));
7143 if (kind0 == '<' || kind0 == '2'
7144 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
7145 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
7146 || code0 == TRUTH_XOR_EXPR)
7148 arg01 = TREE_OPERAND (arg0, 1);
7150 if (TREE_CONSTANT (arg00)
7151 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
7152 && ! has_cleanups (arg00)))
7153 return fold (build (code0, type, arg00,
7154 fold (build1 (CLEANUP_POINT_EXPR,
7155 TREE_TYPE (arg01), arg01))));
7157 if (TREE_CONSTANT (arg01))
7158 return fold (build (code0, type,
7159 fold (build1 (CLEANUP_POINT_EXPR,
7160 TREE_TYPE (arg00), arg00)),
7169 } /* switch (code) */
7172 /* Determine if first argument is a multiple of second argument. Return 0 if
7173 it is not, or we cannot easily determined it to be.
7175 An example of the sort of thing we care about (at this point; this routine
7176 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7177 fold cases do now) is discovering that
7179 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7185 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7187 This code also handles discovering that
7189 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7191 is a multiple of 8 so we don't have to worry about dealing with a
7194 Note that we *look* inside a SAVE_EXPR only to determine how it was
7195 calculated; it is not safe for fold to do much of anything else with the
7196 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7197 at run time. For example, the latter example above *cannot* be implemented
7198 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7199 evaluation time of the original SAVE_EXPR is not necessarily the same at
7200 the time the new expression is evaluated. The only optimization of this
7201 sort that would be valid is changing
7203 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7207 SAVE_EXPR (I) * SAVE_EXPR (J)
7209 (where the same SAVE_EXPR (J) is used in the original and the
7210 transformed version). */
7213 multiple_of_p (type, top, bottom)
7218 if (operand_equal_p (top, bottom, 0))
7221 if (TREE_CODE (type) != INTEGER_TYPE)
7224 switch (TREE_CODE (top))
7227 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7228 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7232 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7233 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7236 /* Can't handle conversions from non-integral or wider integral type. */
7237 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
7238 || (TYPE_PRECISION (type)
7239 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
7242 /* .. fall through ... */
7245 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
7248 if ((TREE_CODE (bottom) != INTEGER_CST)
7249 || (tree_int_cst_sgn (top) < 0)
7250 || (tree_int_cst_sgn (bottom) < 0))
7252 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
7260 /* Return true if `t' is known to be non-negative. */
7263 tree_expr_nonnegative_p (t)
7266 switch (TREE_CODE (t))
7269 return tree_int_cst_sgn (t) >= 0;
7271 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
7272 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
7274 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7276 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
7279 /* We don't know sign of `t', so be safe and return false. */
7284 /* Return true if `r' is known to be non-negative.
7285 Only handles constants at the moment. */
7288 rtl_expr_nonnegative_p (r)
7291 switch (GET_CODE (r))
7294 return INTVAL (r) >= 0;
7297 if (GET_MODE (r) == VOIDmode)
7298 return CONST_DOUBLE_HIGH (r) >= 0;
7303 /* These are always nonnegative. */