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;
1863 if (ggc_p && ! init_p)
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) (sizeof size_table / sizeof size_table[0]))
1875 if (size_table[number] != 0)
1876 for (t = size_table[number]; t != 0; t = TREE_CHAIN (t))
1877 if (TREE_TYPE (t) == type)
1882 /* Make this a permanent node. */
1883 push_obstacks_nochange ();
1884 end_temporary_allocation ();
1887 t = build_int_2 (number, 0);
1888 TREE_TYPE (t) = type;
1889 TREE_CHAIN (t) = size_table[number];
1890 size_table[number] = t;
1898 t = build_int_2 (number, number < 0 ? -1 : 0);
1899 TREE_TYPE (t) = type;
1900 TREE_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (t) = force_fit_type (t, 0);
1904 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1905 is a tree code. The type of the result is taken from the operands.
1906 Both must be the same type integer type and it must be a size type.
1907 If the operands are constant, so is the result. */
1910 size_binop (code, arg0, arg1)
1911 enum tree_code code;
1914 tree type = TREE_TYPE (arg0);
1916 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1917 || type != TREE_TYPE (arg1))
1920 /* Handle the special case of two integer constants faster. */
1921 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1923 /* And some specific cases even faster than that. */
1924 if (code == PLUS_EXPR && integer_zerop (arg0))
1926 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1927 && integer_zerop (arg1))
1929 else if (code == MULT_EXPR && integer_onep (arg0))
1932 /* Handle general case of two integer constants. */
1933 return int_const_binop (code, arg0, arg1, 0, 1);
1936 if (arg0 == error_mark_node || arg1 == error_mark_node)
1937 return error_mark_node;
1939 return fold (build (code, type, arg0, arg1));
1942 /* Given two values, either both of sizetype or both of bitsizetype,
1943 compute the difference between the two values. Return the value
1944 in signed type corresponding to the type of the operands. */
1947 size_diffop (arg0, arg1)
1950 tree type = TREE_TYPE (arg0);
1953 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1954 || type != TREE_TYPE (arg1))
1957 /* If the type is already signed, just do the simple thing. */
1958 if (! TREE_UNSIGNED (type))
1959 return size_binop (MINUS_EXPR, arg0, arg1);
1961 ctype = (type == bitsizetype || type == ubitsizetype
1962 ? sbitsizetype : ssizetype);
1964 /* If either operand is not a constant, do the conversions to the signed
1965 type and subtract. The hardware will do the right thing with any
1966 overflow in the subtraction. */
1967 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1968 return size_binop (MINUS_EXPR, convert (ctype, arg0),
1969 convert (ctype, arg1));
1971 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1972 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1973 overflow) and negate (which can't either). Special-case a result
1974 of zero while we're here. */
1975 if (tree_int_cst_equal (arg0, arg1))
1976 return convert (ctype, integer_zero_node);
1977 else if (tree_int_cst_lt (arg1, arg0))
1978 return convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1980 return size_binop (MINUS_EXPR, convert (ctype, integer_zero_node),
1981 convert (ctype, size_binop (MINUS_EXPR, arg1, arg0)));
1984 /* This structure is used to communicate arguments to fold_convert_1. */
1987 tree arg1; /* Input: value to convert. */
1988 tree type; /* Input: type to convert value to. */
1989 tree t; /* Ouput: result of conversion. */
1992 /* Function to convert floating-point constants, protected by floating
1993 point exception handler. */
1996 fold_convert_1 (data)
1999 struct fc_args *args = (struct fc_args *) data;
2001 args->t = build_real (args->type,
2002 real_value_truncate (TYPE_MODE (args->type),
2003 TREE_REAL_CST (args->arg1)));
2006 /* Given T, a tree representing type conversion of ARG1, a constant,
2007 return a constant tree representing the result of conversion. */
2010 fold_convert (t, arg1)
2014 register tree type = TREE_TYPE (t);
2017 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
2019 if (TREE_CODE (arg1) == INTEGER_CST)
2021 /* If we would build a constant wider than GCC supports,
2022 leave the conversion unfolded. */
2023 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
2026 /* If we are trying to make a sizetype for a small integer, use
2027 size_int to pick up cached types to reduce duplicate nodes. */
2028 if (TREE_CODE (type) == INTEGER_CST && TYPE_IS_SIZETYPE (type)
2029 && compare_tree_int (arg1, 10000) < 0)
2030 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
2032 /* Given an integer constant, make new constant with new type,
2033 appropriately sign-extended or truncated. */
2034 t = build_int_2 (TREE_INT_CST_LOW (arg1),
2035 TREE_INT_CST_HIGH (arg1));
2036 TREE_TYPE (t) = type;
2037 /* Indicate an overflow if (1) ARG1 already overflowed,
2038 or (2) force_fit_type indicates an overflow.
2039 Tell force_fit_type that an overflow has already occurred
2040 if ARG1 is a too-large unsigned value and T is signed.
2041 But don't indicate an overflow if converting a pointer. */
2043 = ((force_fit_type (t,
2044 (TREE_INT_CST_HIGH (arg1) < 0
2045 && (TREE_UNSIGNED (type)
2046 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
2047 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
2048 || TREE_OVERFLOW (arg1));
2049 TREE_CONSTANT_OVERFLOW (t)
2050 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2052 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2053 else if (TREE_CODE (arg1) == REAL_CST)
2055 /* Don't initialize these, use assignments.
2056 Initialized local aggregates don't work on old compilers. */
2060 tree type1 = TREE_TYPE (arg1);
2063 x = TREE_REAL_CST (arg1);
2064 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
2066 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
2067 if (!no_upper_bound)
2068 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
2070 /* See if X will be in range after truncation towards 0.
2071 To compensate for truncation, move the bounds away from 0,
2072 but reject if X exactly equals the adjusted bounds. */
2073 #ifdef REAL_ARITHMETIC
2074 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
2075 if (!no_upper_bound)
2076 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
2079 if (!no_upper_bound)
2082 /* If X is a NaN, use zero instead and show we have an overflow.
2083 Otherwise, range check. */
2084 if (REAL_VALUE_ISNAN (x))
2085 overflow = 1, x = dconst0;
2086 else if (! (REAL_VALUES_LESS (l, x)
2088 && REAL_VALUES_LESS (x, u)))
2091 #ifndef REAL_ARITHMETIC
2093 HOST_WIDE_INT low, high;
2094 HOST_WIDE_INT half_word
2095 = (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2);
2100 high = (HOST_WIDE_INT) (x / half_word / half_word);
2101 x -= (REAL_VALUE_TYPE) high * half_word * half_word;
2102 if (x >= (REAL_VALUE_TYPE) half_word * half_word / 2)
2104 low = x - (REAL_VALUE_TYPE) half_word * half_word / 2;
2105 low |= (HOST_WIDE_INT) -1 << (HOST_BITS_PER_WIDE_INT - 1);
2108 low = (HOST_WIDE_INT) x;
2109 if (TREE_REAL_CST (arg1) < 0)
2110 neg_double (low, high, &low, &high);
2111 t = build_int_2 (low, high);
2115 HOST_WIDE_INT low, high;
2116 REAL_VALUE_TO_INT (&low, &high, x);
2117 t = build_int_2 (low, high);
2120 TREE_TYPE (t) = type;
2122 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
2123 TREE_CONSTANT_OVERFLOW (t)
2124 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2126 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2127 TREE_TYPE (t) = type;
2129 else if (TREE_CODE (type) == REAL_TYPE)
2131 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2132 if (TREE_CODE (arg1) == INTEGER_CST)
2133 return build_real_from_int_cst (type, arg1);
2134 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2135 if (TREE_CODE (arg1) == REAL_CST)
2137 struct fc_args args;
2139 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
2142 TREE_TYPE (arg1) = type;
2146 /* Setup input for fold_convert_1() */
2150 if (do_float_handler (fold_convert_1, (PTR) &args))
2152 /* Receive output from fold_convert_1() */
2157 /* We got an exception from fold_convert_1() */
2159 t = copy_node (arg1);
2163 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
2164 TREE_CONSTANT_OVERFLOW (t)
2165 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2169 TREE_CONSTANT (t) = 1;
2173 /* Return an expr equal to X but certainly not valid as an lvalue. */
2181 /* These things are certainly not lvalues. */
2182 if (TREE_CODE (x) == NON_LVALUE_EXPR
2183 || TREE_CODE (x) == INTEGER_CST
2184 || TREE_CODE (x) == REAL_CST
2185 || TREE_CODE (x) == STRING_CST
2186 || TREE_CODE (x) == ADDR_EXPR)
2189 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2190 TREE_CONSTANT (result) = TREE_CONSTANT (x);
2194 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2195 Zero means allow extended lvalues. */
2197 int pedantic_lvalues;
2199 /* When pedantic, return an expr equal to X but certainly not valid as a
2200 pedantic lvalue. Otherwise, return X. */
2203 pedantic_non_lvalue (x)
2206 if (pedantic_lvalues)
2207 return non_lvalue (x);
2212 /* Given a tree comparison code, return the code that is the logical inverse
2213 of the given code. It is not safe to do this for floating-point
2214 comparisons, except for NE_EXPR and EQ_EXPR. */
2216 static enum tree_code
2217 invert_tree_comparison (code)
2218 enum tree_code code;
2239 /* Similar, but return the comparison that results if the operands are
2240 swapped. This is safe for floating-point. */
2242 static enum tree_code
2243 swap_tree_comparison (code)
2244 enum tree_code code;
2264 /* Return nonzero if CODE is a tree code that represents a truth value. */
2267 truth_value_p (code)
2268 enum tree_code code;
2270 return (TREE_CODE_CLASS (code) == '<'
2271 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2272 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2273 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2276 /* Return nonzero if two operands are necessarily equal.
2277 If ONLY_CONST is non-zero, only return non-zero for constants.
2278 This function tests whether the operands are indistinguishable;
2279 it does not test whether they are equal using C's == operation.
2280 The distinction is important for IEEE floating point, because
2281 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2282 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
2285 operand_equal_p (arg0, arg1, only_const)
2289 /* If both types don't have the same signedness, then we can't consider
2290 them equal. We must check this before the STRIP_NOPS calls
2291 because they may change the signedness of the arguments. */
2292 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
2298 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2299 /* This is needed for conversions and for COMPONENT_REF.
2300 Might as well play it safe and always test this. */
2301 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2302 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2303 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2306 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2307 We don't care about side effects in that case because the SAVE_EXPR
2308 takes care of that for us. In all other cases, two expressions are
2309 equal if they have no side effects. If we have two identical
2310 expressions with side effects that should be treated the same due
2311 to the only side effects being identical SAVE_EXPR's, that will
2312 be detected in the recursive calls below. */
2313 if (arg0 == arg1 && ! only_const
2314 && (TREE_CODE (arg0) == SAVE_EXPR
2315 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2318 /* Next handle constant cases, those for which we can return 1 even
2319 if ONLY_CONST is set. */
2320 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2321 switch (TREE_CODE (arg0))
2324 return (! TREE_CONSTANT_OVERFLOW (arg0)
2325 && ! TREE_CONSTANT_OVERFLOW (arg1)
2326 && tree_int_cst_equal (arg0, arg1));
2329 return (! TREE_CONSTANT_OVERFLOW (arg0)
2330 && ! TREE_CONSTANT_OVERFLOW (arg1)
2331 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2332 TREE_REAL_CST (arg1)));
2335 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2337 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2341 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2342 && ! memcmp (TREE_STRING_POINTER (arg0),
2343 TREE_STRING_POINTER (arg1),
2344 TREE_STRING_LENGTH (arg0)));
2347 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2356 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2359 /* Two conversions are equal only if signedness and modes match. */
2360 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2361 && (TREE_UNSIGNED (TREE_TYPE (arg0))
2362 != TREE_UNSIGNED (TREE_TYPE (arg1))))
2365 return operand_equal_p (TREE_OPERAND (arg0, 0),
2366 TREE_OPERAND (arg1, 0), 0);
2370 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
2371 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
2375 /* For commutative ops, allow the other order. */
2376 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
2377 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
2378 || TREE_CODE (arg0) == BIT_IOR_EXPR
2379 || TREE_CODE (arg0) == BIT_XOR_EXPR
2380 || TREE_CODE (arg0) == BIT_AND_EXPR
2381 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
2382 && operand_equal_p (TREE_OPERAND (arg0, 0),
2383 TREE_OPERAND (arg1, 1), 0)
2384 && operand_equal_p (TREE_OPERAND (arg0, 1),
2385 TREE_OPERAND (arg1, 0), 0));
2388 /* If either of the pointer (or reference) expressions we are dereferencing
2389 contain a side effect, these cannot be equal. */
2390 if (TREE_SIDE_EFFECTS (arg0)
2391 || TREE_SIDE_EFFECTS (arg1))
2394 switch (TREE_CODE (arg0))
2397 return operand_equal_p (TREE_OPERAND (arg0, 0),
2398 TREE_OPERAND (arg1, 0), 0);
2402 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2403 TREE_OPERAND (arg1, 0), 0)
2404 && operand_equal_p (TREE_OPERAND (arg0, 1),
2405 TREE_OPERAND (arg1, 1), 0));
2408 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2409 TREE_OPERAND (arg1, 0), 0)
2410 && operand_equal_p (TREE_OPERAND (arg0, 1),
2411 TREE_OPERAND (arg1, 1), 0)
2412 && operand_equal_p (TREE_OPERAND (arg0, 2),
2413 TREE_OPERAND (arg1, 2), 0));
2419 if (TREE_CODE (arg0) == RTL_EXPR)
2420 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2428 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2429 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2431 When in doubt, return 0. */
2434 operand_equal_for_comparison_p (arg0, arg1, other)
2438 int unsignedp1, unsignedpo;
2439 tree primarg0, primarg1, primother;
2440 unsigned int correct_width;
2442 if (operand_equal_p (arg0, arg1, 0))
2445 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2446 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2449 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2450 and see if the inner values are the same. This removes any
2451 signedness comparison, which doesn't matter here. */
2452 primarg0 = arg0, primarg1 = arg1;
2453 STRIP_NOPS (primarg0);
2454 STRIP_NOPS (primarg1);
2455 if (operand_equal_p (primarg0, primarg1, 0))
2458 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2459 actual comparison operand, ARG0.
2461 First throw away any conversions to wider types
2462 already present in the operands. */
2464 primarg1 = get_narrower (arg1, &unsignedp1);
2465 primother = get_narrower (other, &unsignedpo);
2467 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2468 if (unsignedp1 == unsignedpo
2469 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2470 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2472 tree type = TREE_TYPE (arg0);
2474 /* Make sure shorter operand is extended the right way
2475 to match the longer operand. */
2476 primarg1 = convert (signed_or_unsigned_type (unsignedp1,
2477 TREE_TYPE (primarg1)),
2480 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2487 /* See if ARG is an expression that is either a comparison or is performing
2488 arithmetic on comparisons. The comparisons must only be comparing
2489 two different values, which will be stored in *CVAL1 and *CVAL2; if
2490 they are non-zero it means that some operands have already been found.
2491 No variables may be used anywhere else in the expression except in the
2492 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2493 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2495 If this is true, return 1. Otherwise, return zero. */
2498 twoval_comparison_p (arg, cval1, cval2, save_p)
2500 tree *cval1, *cval2;
2503 enum tree_code code = TREE_CODE (arg);
2504 char class = TREE_CODE_CLASS (code);
2506 /* We can handle some of the 'e' cases here. */
2507 if (class == 'e' && code == TRUTH_NOT_EXPR)
2509 else if (class == 'e'
2510 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2511 || code == COMPOUND_EXPR))
2514 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2515 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2517 /* If we've already found a CVAL1 or CVAL2, this expression is
2518 two complex to handle. */
2519 if (*cval1 || *cval2)
2529 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2532 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2533 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2534 cval1, cval2, save_p));
2540 if (code == COND_EXPR)
2541 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2542 cval1, cval2, save_p)
2543 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2544 cval1, cval2, save_p)
2545 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2546 cval1, cval2, save_p));
2550 /* First see if we can handle the first operand, then the second. For
2551 the second operand, we know *CVAL1 can't be zero. It must be that
2552 one side of the comparison is each of the values; test for the
2553 case where this isn't true by failing if the two operands
2556 if (operand_equal_p (TREE_OPERAND (arg, 0),
2557 TREE_OPERAND (arg, 1), 0))
2561 *cval1 = TREE_OPERAND (arg, 0);
2562 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2564 else if (*cval2 == 0)
2565 *cval2 = TREE_OPERAND (arg, 0);
2566 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2571 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2573 else if (*cval2 == 0)
2574 *cval2 = TREE_OPERAND (arg, 1);
2575 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2587 /* ARG is a tree that is known to contain just arithmetic operations and
2588 comparisons. Evaluate the operations in the tree substituting NEW0 for
2589 any occurrence of OLD0 as an operand of a comparison and likewise for
2593 eval_subst (arg, old0, new0, old1, new1)
2595 tree old0, new0, old1, new1;
2597 tree type = TREE_TYPE (arg);
2598 enum tree_code code = TREE_CODE (arg);
2599 char class = TREE_CODE_CLASS (code);
2601 /* We can handle some of the 'e' cases here. */
2602 if (class == 'e' && code == TRUTH_NOT_EXPR)
2604 else if (class == 'e'
2605 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2611 return fold (build1 (code, type,
2612 eval_subst (TREE_OPERAND (arg, 0),
2613 old0, new0, old1, new1)));
2616 return fold (build (code, type,
2617 eval_subst (TREE_OPERAND (arg, 0),
2618 old0, new0, old1, new1),
2619 eval_subst (TREE_OPERAND (arg, 1),
2620 old0, new0, old1, new1)));
2626 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2629 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2632 return fold (build (code, type,
2633 eval_subst (TREE_OPERAND (arg, 0),
2634 old0, new0, old1, new1),
2635 eval_subst (TREE_OPERAND (arg, 1),
2636 old0, new0, old1, new1),
2637 eval_subst (TREE_OPERAND (arg, 2),
2638 old0, new0, old1, new1)));
2642 /* fall through - ??? */
2646 tree arg0 = TREE_OPERAND (arg, 0);
2647 tree arg1 = TREE_OPERAND (arg, 1);
2649 /* We need to check both for exact equality and tree equality. The
2650 former will be true if the operand has a side-effect. In that
2651 case, we know the operand occurred exactly once. */
2653 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2655 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2658 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2660 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2663 return fold (build (code, type, arg0, arg1));
2671 /* Return a tree for the case when the result of an expression is RESULT
2672 converted to TYPE and OMITTED was previously an operand of the expression
2673 but is now not needed (e.g., we folded OMITTED * 0).
2675 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2676 the conversion of RESULT to TYPE. */
2679 omit_one_operand (type, result, omitted)
2680 tree type, result, omitted;
2682 tree t = convert (type, result);
2684 if (TREE_SIDE_EFFECTS (omitted))
2685 return build (COMPOUND_EXPR, type, omitted, t);
2687 return non_lvalue (t);
2690 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2693 pedantic_omit_one_operand (type, result, omitted)
2694 tree type, result, omitted;
2696 tree t = convert (type, result);
2698 if (TREE_SIDE_EFFECTS (omitted))
2699 return build (COMPOUND_EXPR, type, omitted, t);
2701 return pedantic_non_lvalue (t);
2704 /* Return a simplified tree node for the truth-negation of ARG. This
2705 never alters ARG itself. We assume that ARG is an operation that
2706 returns a truth value (0 or 1). */
2709 invert_truthvalue (arg)
2712 tree type = TREE_TYPE (arg);
2713 enum tree_code code = TREE_CODE (arg);
2715 if (code == ERROR_MARK)
2718 /* If this is a comparison, we can simply invert it, except for
2719 floating-point non-equality comparisons, in which case we just
2720 enclose a TRUTH_NOT_EXPR around what we have. */
2722 if (TREE_CODE_CLASS (code) == '<')
2724 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2725 && !flag_fast_math && code != NE_EXPR && code != EQ_EXPR)
2726 return build1 (TRUTH_NOT_EXPR, type, arg);
2728 return build (invert_tree_comparison (code), type,
2729 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2735 return convert (type, build_int_2 (integer_zerop (arg), 0));
2737 case TRUTH_AND_EXPR:
2738 return build (TRUTH_OR_EXPR, type,
2739 invert_truthvalue (TREE_OPERAND (arg, 0)),
2740 invert_truthvalue (TREE_OPERAND (arg, 1)));
2743 return build (TRUTH_AND_EXPR, type,
2744 invert_truthvalue (TREE_OPERAND (arg, 0)),
2745 invert_truthvalue (TREE_OPERAND (arg, 1)));
2747 case TRUTH_XOR_EXPR:
2748 /* Here we can invert either operand. We invert the first operand
2749 unless the second operand is a TRUTH_NOT_EXPR in which case our
2750 result is the XOR of the first operand with the inside of the
2751 negation of the second operand. */
2753 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2754 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2755 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2757 return build (TRUTH_XOR_EXPR, type,
2758 invert_truthvalue (TREE_OPERAND (arg, 0)),
2759 TREE_OPERAND (arg, 1));
2761 case TRUTH_ANDIF_EXPR:
2762 return build (TRUTH_ORIF_EXPR, type,
2763 invert_truthvalue (TREE_OPERAND (arg, 0)),
2764 invert_truthvalue (TREE_OPERAND (arg, 1)));
2766 case TRUTH_ORIF_EXPR:
2767 return build (TRUTH_ANDIF_EXPR, type,
2768 invert_truthvalue (TREE_OPERAND (arg, 0)),
2769 invert_truthvalue (TREE_OPERAND (arg, 1)));
2771 case TRUTH_NOT_EXPR:
2772 return TREE_OPERAND (arg, 0);
2775 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2776 invert_truthvalue (TREE_OPERAND (arg, 1)),
2777 invert_truthvalue (TREE_OPERAND (arg, 2)));
2780 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2781 invert_truthvalue (TREE_OPERAND (arg, 1)));
2783 case WITH_RECORD_EXPR:
2784 return build (WITH_RECORD_EXPR, type,
2785 invert_truthvalue (TREE_OPERAND (arg, 0)),
2786 TREE_OPERAND (arg, 1));
2788 case NON_LVALUE_EXPR:
2789 return invert_truthvalue (TREE_OPERAND (arg, 0));
2794 return build1 (TREE_CODE (arg), type,
2795 invert_truthvalue (TREE_OPERAND (arg, 0)));
2798 if (!integer_onep (TREE_OPERAND (arg, 1)))
2800 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2803 return build1 (TRUTH_NOT_EXPR, type, arg);
2805 case CLEANUP_POINT_EXPR:
2806 return build1 (CLEANUP_POINT_EXPR, type,
2807 invert_truthvalue (TREE_OPERAND (arg, 0)));
2812 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2814 return build1 (TRUTH_NOT_EXPR, type, arg);
2817 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2818 operands are another bit-wise operation with a common input. If so,
2819 distribute the bit operations to save an operation and possibly two if
2820 constants are involved. For example, convert
2821 (A | B) & (A | C) into A | (B & C)
2822 Further simplification will occur if B and C are constants.
2824 If this optimization cannot be done, 0 will be returned. */
2827 distribute_bit_expr (code, type, arg0, arg1)
2828 enum tree_code code;
2835 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2836 || TREE_CODE (arg0) == code
2837 || (TREE_CODE (arg0) != BIT_AND_EXPR
2838 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2841 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2843 common = TREE_OPERAND (arg0, 0);
2844 left = TREE_OPERAND (arg0, 1);
2845 right = TREE_OPERAND (arg1, 1);
2847 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2849 common = TREE_OPERAND (arg0, 0);
2850 left = TREE_OPERAND (arg0, 1);
2851 right = TREE_OPERAND (arg1, 0);
2853 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2855 common = TREE_OPERAND (arg0, 1);
2856 left = TREE_OPERAND (arg0, 0);
2857 right = TREE_OPERAND (arg1, 1);
2859 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2861 common = TREE_OPERAND (arg0, 1);
2862 left = TREE_OPERAND (arg0, 0);
2863 right = TREE_OPERAND (arg1, 0);
2868 return fold (build (TREE_CODE (arg0), type, common,
2869 fold (build (code, type, left, right))));
2872 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2873 starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */
2876 make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp)
2879 int bitsize, bitpos;
2882 tree result = build (BIT_FIELD_REF, type, inner,
2883 size_int (bitsize), bitsize_int (bitpos));
2885 TREE_UNSIGNED (result) = unsignedp;
2890 /* Optimize a bit-field compare.
2892 There are two cases: First is a compare against a constant and the
2893 second is a comparison of two items where the fields are at the same
2894 bit position relative to the start of a chunk (byte, halfword, word)
2895 large enough to contain it. In these cases we can avoid the shift
2896 implicit in bitfield extractions.
2898 For constants, we emit a compare of the shifted constant with the
2899 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2900 compared. For two fields at the same position, we do the ANDs with the
2901 similar mask and compare the result of the ANDs.
2903 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2904 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2905 are the left and right operands of the comparison, respectively.
2907 If the optimization described above can be done, we return the resulting
2908 tree. Otherwise we return zero. */
2911 optimize_bit_field_compare (code, compare_type, lhs, rhs)
2912 enum tree_code code;
2916 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2917 tree type = TREE_TYPE (lhs);
2918 tree signed_type, unsigned_type;
2919 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2920 enum machine_mode lmode, rmode, nmode;
2921 int lunsignedp, runsignedp;
2922 int lvolatilep = 0, rvolatilep = 0;
2923 unsigned int alignment;
2924 tree linner, rinner = NULL_TREE;
2928 /* Get all the information about the extractions being done. If the bit size
2929 if the same as the size of the underlying object, we aren't doing an
2930 extraction at all and so can do nothing. We also don't want to
2931 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2932 then will no longer be able to replace it. */
2933 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2934 &lunsignedp, &lvolatilep, &alignment);
2935 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2936 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2941 /* If this is not a constant, we can only do something if bit positions,
2942 sizes, and signedness are the same. */
2943 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2944 &runsignedp, &rvolatilep, &alignment);
2946 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2947 || lunsignedp != runsignedp || offset != 0
2948 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2952 /* See if we can find a mode to refer to this field. We should be able to,
2953 but fail if we can't. */
2954 nmode = get_best_mode (lbitsize, lbitpos,
2955 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2956 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2957 TYPE_ALIGN (TREE_TYPE (rinner))),
2958 word_mode, lvolatilep || rvolatilep);
2959 if (nmode == VOIDmode)
2962 /* Set signed and unsigned types of the precision of this mode for the
2964 signed_type = type_for_mode (nmode, 0);
2965 unsigned_type = type_for_mode (nmode, 1);
2967 /* Compute the bit position and size for the new reference and our offset
2968 within it. If the new reference is the same size as the original, we
2969 won't optimize anything, so return zero. */
2970 nbitsize = GET_MODE_BITSIZE (nmode);
2971 nbitpos = lbitpos & ~ (nbitsize - 1);
2973 if (nbitsize == lbitsize)
2976 if (BYTES_BIG_ENDIAN)
2977 lbitpos = nbitsize - lbitsize - lbitpos;
2979 /* Make the mask to be used against the extracted field. */
2980 mask = build_int_2 (~0, ~0);
2981 TREE_TYPE (mask) = unsigned_type;
2982 force_fit_type (mask, 0);
2983 mask = convert (unsigned_type, mask);
2984 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2985 mask = const_binop (RSHIFT_EXPR, mask,
2986 size_int (nbitsize - lbitsize - lbitpos), 0);
2989 /* If not comparing with constant, just rework the comparison
2991 return build (code, compare_type,
2992 build (BIT_AND_EXPR, unsigned_type,
2993 make_bit_field_ref (linner, unsigned_type,
2994 nbitsize, nbitpos, 1),
2996 build (BIT_AND_EXPR, unsigned_type,
2997 make_bit_field_ref (rinner, unsigned_type,
2998 nbitsize, nbitpos, 1),
3001 /* Otherwise, we are handling the constant case. See if the constant is too
3002 big for the field. Warn and return a tree of for 0 (false) if so. We do
3003 this not only for its own sake, but to avoid having to test for this
3004 error case below. If we didn't, we might generate wrong code.
3006 For unsigned fields, the constant shifted right by the field length should
3007 be all zero. For signed fields, the high-order bits should agree with
3012 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3013 convert (unsigned_type, rhs),
3014 size_int (lbitsize), 0)))
3016 warning ("comparison is always %d due to width of bitfield",
3018 return convert (compare_type,
3020 ? integer_one_node : integer_zero_node));
3025 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
3026 size_int (lbitsize - 1), 0);
3027 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3029 warning ("comparison is always %d due to width of bitfield",
3031 return convert (compare_type,
3033 ? integer_one_node : integer_zero_node));
3037 /* Single-bit compares should always be against zero. */
3038 if (lbitsize == 1 && ! integer_zerop (rhs))
3040 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3041 rhs = convert (type, integer_zero_node);
3044 /* Make a new bitfield reference, shift the constant over the
3045 appropriate number of bits and mask it with the computed mask
3046 (in case this was a signed field). If we changed it, make a new one. */
3047 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
3050 TREE_SIDE_EFFECTS (lhs) = 1;
3051 TREE_THIS_VOLATILE (lhs) = 1;
3054 rhs = fold (const_binop (BIT_AND_EXPR,
3055 const_binop (LSHIFT_EXPR,
3056 convert (unsigned_type, rhs),
3057 size_int (lbitpos), 0),
3060 return build (code, compare_type,
3061 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
3065 /* Subroutine for fold_truthop: decode a field reference.
3067 If EXP is a comparison reference, we return the innermost reference.
3069 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3070 set to the starting bit number.
3072 If the innermost field can be completely contained in a mode-sized
3073 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3075 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3076 otherwise it is not changed.
3078 *PUNSIGNEDP is set to the signedness of the field.
3080 *PMASK is set to the mask used. This is either contained in a
3081 BIT_AND_EXPR or derived from the width of the field.
3083 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3085 Return 0 if this is not a component reference or is one that we can't
3086 do anything with. */
3089 decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp,
3090 pvolatilep, pmask, pand_mask)
3092 HOST_WIDE_INT *pbitsize, *pbitpos;
3093 enum machine_mode *pmode;
3094 int *punsignedp, *pvolatilep;
3099 tree mask, inner, offset;
3101 unsigned int precision;
3102 unsigned int alignment;
3104 /* All the optimizations using this function assume integer fields.
3105 There are problems with FP fields since the type_for_size call
3106 below can fail for, e.g., XFmode. */
3107 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3112 if (TREE_CODE (exp) == BIT_AND_EXPR)
3114 and_mask = TREE_OPERAND (exp, 1);
3115 exp = TREE_OPERAND (exp, 0);
3116 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3117 if (TREE_CODE (and_mask) != INTEGER_CST)
3121 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3122 punsignedp, pvolatilep, &alignment);
3123 if ((inner == exp && and_mask == 0)
3124 || *pbitsize < 0 || offset != 0
3125 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3128 /* Compute the mask to access the bitfield. */
3129 unsigned_type = type_for_size (*pbitsize, 1);
3130 precision = TYPE_PRECISION (unsigned_type);
3132 mask = build_int_2 (~0, ~0);
3133 TREE_TYPE (mask) = unsigned_type;
3134 force_fit_type (mask, 0);
3135 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3136 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3138 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3140 mask = fold (build (BIT_AND_EXPR, unsigned_type,
3141 convert (unsigned_type, and_mask), mask));
3144 *pand_mask = and_mask;
3148 /* Return non-zero if MASK represents a mask of SIZE ones in the low-order
3152 all_ones_mask_p (mask, size)
3156 tree type = TREE_TYPE (mask);
3157 unsigned int precision = TYPE_PRECISION (type);
3160 tmask = build_int_2 (~0, ~0);
3161 TREE_TYPE (tmask) = signed_type (type);
3162 force_fit_type (tmask, 0);
3164 tree_int_cst_equal (mask,
3165 const_binop (RSHIFT_EXPR,
3166 const_binop (LSHIFT_EXPR, tmask,
3167 size_int (precision - size),
3169 size_int (precision - size), 0));
3172 /* Subroutine for fold_truthop: determine if an operand is simple enough
3173 to be evaluated unconditionally. */
3176 simple_operand_p (exp)
3179 /* Strip any conversions that don't change the machine mode. */
3180 while ((TREE_CODE (exp) == NOP_EXPR
3181 || TREE_CODE (exp) == CONVERT_EXPR)
3182 && (TYPE_MODE (TREE_TYPE (exp))
3183 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
3184 exp = TREE_OPERAND (exp, 0);
3186 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
3188 && ! TREE_ADDRESSABLE (exp)
3189 && ! TREE_THIS_VOLATILE (exp)
3190 && ! DECL_NONLOCAL (exp)
3191 /* Don't regard global variables as simple. They may be
3192 allocated in ways unknown to the compiler (shared memory,
3193 #pragma weak, etc). */
3194 && ! TREE_PUBLIC (exp)
3195 && ! DECL_EXTERNAL (exp)
3196 /* Loading a static variable is unduly expensive, but global
3197 registers aren't expensive. */
3198 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3201 /* The following functions are subroutines to fold_range_test and allow it to
3202 try to change a logical combination of comparisons into a range test.
3205 X == 2 || X == 3 || X == 4 || X == 5
3209 (unsigned) (X - 2) <= 3
3211 We describe each set of comparisons as being either inside or outside
3212 a range, using a variable named like IN_P, and then describe the
3213 range with a lower and upper bound. If one of the bounds is omitted,
3214 it represents either the highest or lowest value of the type.
3216 In the comments below, we represent a range by two numbers in brackets
3217 preceded by a "+" to designate being inside that range, or a "-" to
3218 designate being outside that range, so the condition can be inverted by
3219 flipping the prefix. An omitted bound is represented by a "-". For
3220 example, "- [-, 10]" means being outside the range starting at the lowest
3221 possible value and ending at 10, in other words, being greater than 10.
3222 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3225 We set up things so that the missing bounds are handled in a consistent
3226 manner so neither a missing bound nor "true" and "false" need to be
3227 handled using a special case. */
3229 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3230 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3231 and UPPER1_P are nonzero if the respective argument is an upper bound
3232 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3233 must be specified for a comparison. ARG1 will be converted to ARG0's
3234 type if both are specified. */
3237 range_binop (code, type, arg0, upper0_p, arg1, upper1_p)
3238 enum tree_code code;
3241 int upper0_p, upper1_p;
3247 /* If neither arg represents infinity, do the normal operation.
3248 Else, if not a comparison, return infinity. Else handle the special
3249 comparison rules. Note that most of the cases below won't occur, but
3250 are handled for consistency. */
3252 if (arg0 != 0 && arg1 != 0)
3254 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
3255 arg0, convert (TREE_TYPE (arg0), arg1)));
3257 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3260 if (TREE_CODE_CLASS (code) != '<')
3263 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3264 for neither. In real maths, we cannot assume open ended ranges are
3265 the same. But, this is computer arithmetic, where numbers are finite.
3266 We can therefore make the transformation of any unbounded range with
3267 the value Z, Z being greater than any representable number. This permits
3268 us to treat unbounded ranges as equal. */
3269 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3270 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3274 result = sgn0 == sgn1;
3277 result = sgn0 != sgn1;
3280 result = sgn0 < sgn1;
3283 result = sgn0 <= sgn1;
3286 result = sgn0 > sgn1;
3289 result = sgn0 >= sgn1;
3295 return convert (type, result ? integer_one_node : integer_zero_node);
3298 /* Given EXP, a logical expression, set the range it is testing into
3299 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3300 actually being tested. *PLOW and *PHIGH will be made of the same type
3301 as the returned expression. If EXP is not a comparison, we will most
3302 likely not be returning a useful value and range. */
3305 make_range (exp, pin_p, plow, phigh)
3310 enum tree_code code;
3311 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
3312 tree orig_type = NULL_TREE;
3314 tree low, high, n_low, n_high;
3316 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3317 and see if we can refine the range. Some of the cases below may not
3318 happen, but it doesn't seem worth worrying about this. We "continue"
3319 the outer loop when we've changed something; otherwise we "break"
3320 the switch, which will "break" the while. */
3322 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
3326 code = TREE_CODE (exp);
3328 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3330 arg0 = TREE_OPERAND (exp, 0);
3331 if (TREE_CODE_CLASS (code) == '<'
3332 || TREE_CODE_CLASS (code) == '1'
3333 || TREE_CODE_CLASS (code) == '2')
3334 type = TREE_TYPE (arg0);
3335 if (TREE_CODE_CLASS (code) == '2'
3336 || TREE_CODE_CLASS (code) == '<'
3337 || (TREE_CODE_CLASS (code) == 'e'
3338 && TREE_CODE_LENGTH (code) > 1))
3339 arg1 = TREE_OPERAND (exp, 1);
3342 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3343 lose a cast by accident. */
3344 if (type != NULL_TREE && orig_type == NULL_TREE)
3349 case TRUTH_NOT_EXPR:
3350 in_p = ! in_p, exp = arg0;
3353 case EQ_EXPR: case NE_EXPR:
3354 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3355 /* We can only do something if the range is testing for zero
3356 and if the second operand is an integer constant. Note that
3357 saying something is "in" the range we make is done by
3358 complementing IN_P since it will set in the initial case of
3359 being not equal to zero; "out" is leaving it alone. */
3360 if (low == 0 || high == 0
3361 || ! integer_zerop (low) || ! integer_zerop (high)
3362 || TREE_CODE (arg1) != INTEGER_CST)
3367 case NE_EXPR: /* - [c, c] */
3370 case EQ_EXPR: /* + [c, c] */
3371 in_p = ! in_p, low = high = arg1;
3373 case GT_EXPR: /* - [-, c] */
3374 low = 0, high = arg1;
3376 case GE_EXPR: /* + [c, -] */
3377 in_p = ! in_p, low = arg1, high = 0;
3379 case LT_EXPR: /* - [c, -] */
3380 low = arg1, high = 0;
3382 case LE_EXPR: /* + [-, c] */
3383 in_p = ! in_p, low = 0, high = arg1;
3391 /* If this is an unsigned comparison, we also know that EXP is
3392 greater than or equal to zero. We base the range tests we make
3393 on that fact, so we record it here so we can parse existing
3395 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3397 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3398 1, convert (type, integer_zero_node),
3402 in_p = n_in_p, low = n_low, high = n_high;
3404 /* If the high bound is missing, but we
3405 have a low bound, reverse the range so
3406 it goes from zero to the low bound minus 1. */
3407 if (high == 0 && low)
3410 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3411 integer_one_node, 0);
3412 low = convert (type, integer_zero_node);
3418 /* (-x) IN [a,b] -> x in [-b, -a] */
3419 n_low = range_binop (MINUS_EXPR, type,
3420 convert (type, integer_zero_node), 0, high, 1);
3421 n_high = range_binop (MINUS_EXPR, type,
3422 convert (type, integer_zero_node), 0, low, 0);
3423 low = n_low, high = n_high;
3429 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3430 convert (type, integer_one_node));
3433 case PLUS_EXPR: case MINUS_EXPR:
3434 if (TREE_CODE (arg1) != INTEGER_CST)
3437 /* If EXP is signed, any overflow in the computation is undefined,
3438 so we don't worry about it so long as our computations on
3439 the bounds don't overflow. For unsigned, overflow is defined
3440 and this is exactly the right thing. */
3441 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3442 type, low, 0, arg1, 0);
3443 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3444 type, high, 1, arg1, 0);
3445 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3446 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3449 /* Check for an unsigned range which has wrapped around the maximum
3450 value thus making n_high < n_low, and normalize it. */
3451 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3453 low = range_binop (PLUS_EXPR, type, n_high, 0,
3454 integer_one_node, 0);
3455 high = range_binop (MINUS_EXPR, type, n_low, 0,
3456 integer_one_node, 0);
3458 /* If the range is of the form +/- [ x+1, x ], we won't
3459 be able to normalize it. But then, it represents the
3460 whole range or the empty set, so make it
3462 if (tree_int_cst_equal (n_low, low)
3463 && tree_int_cst_equal (n_high, high))
3469 low = n_low, high = n_high;
3474 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3475 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3478 if (! INTEGRAL_TYPE_P (type)
3479 || (low != 0 && ! int_fits_type_p (low, type))
3480 || (high != 0 && ! int_fits_type_p (high, type)))
3483 n_low = low, n_high = high;
3486 n_low = convert (type, n_low);
3489 n_high = convert (type, n_high);
3491 /* If we're converting from an unsigned to a signed type,
3492 we will be doing the comparison as unsigned. The tests above
3493 have already verified that LOW and HIGH are both positive.
3495 So we have to make sure that the original unsigned value will
3496 be interpreted as positive. */
3497 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3499 tree equiv_type = type_for_mode (TYPE_MODE (type), 1);
3502 /* A range without an upper bound is, naturally, unbounded.
3503 Since convert would have cropped a very large value, use
3504 the max value for the destination type. */
3506 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3507 : TYPE_MAX_VALUE (type);
3509 high_positive = fold (build (RSHIFT_EXPR, type,
3510 convert (type, high_positive),
3511 convert (type, integer_one_node)));
3513 /* If the low bound is specified, "and" the range with the
3514 range for which the original unsigned value will be
3518 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3520 1, convert (type, integer_zero_node),
3524 in_p = (n_in_p == in_p);
3528 /* Otherwise, "or" the range with the range of the input
3529 that will be interpreted as negative. */
3530 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3532 1, convert (type, integer_zero_node),
3536 in_p = (in_p != n_in_p);
3541 low = n_low, high = n_high;
3551 /* If EXP is a constant, we can evaluate whether this is true or false. */
3552 if (TREE_CODE (exp) == INTEGER_CST)
3554 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3556 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3562 *pin_p = in_p, *plow = low, *phigh = high;
3566 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3567 type, TYPE, return an expression to test if EXP is in (or out of, depending
3568 on IN_P) the range. */
3571 build_range_check (type, exp, in_p, low, high)
3577 tree etype = TREE_TYPE (exp);
3581 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3582 return invert_truthvalue (value);
3584 else if (low == 0 && high == 0)
3585 return convert (type, integer_one_node);
3588 return fold (build (LE_EXPR, type, exp, high));
3591 return fold (build (GE_EXPR, type, exp, low));
3593 else if (operand_equal_p (low, high, 0))
3594 return fold (build (EQ_EXPR, type, exp, low));
3596 else if (TREE_UNSIGNED (etype) && integer_zerop (low))
3597 return build_range_check (type, exp, 1, 0, high);
3599 else if (integer_zerop (low))
3601 utype = unsigned_type (etype);
3602 return build_range_check (type, convert (utype, exp), 1, 0,
3603 convert (utype, high));
3606 else if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3607 && ! TREE_OVERFLOW (value))
3608 return build_range_check (type,
3609 fold (build (MINUS_EXPR, etype, exp, low)),
3610 1, convert (etype, integer_zero_node), value);
3615 /* Given two ranges, see if we can merge them into one. Return 1 if we
3616 can, 0 if we can't. Set the output range into the specified parameters. */
3619 merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
3623 tree low0, high0, low1, high1;
3631 int lowequal = ((low0 == 0 && low1 == 0)
3632 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3633 low0, 0, low1, 0)));
3634 int highequal = ((high0 == 0 && high1 == 0)
3635 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3636 high0, 1, high1, 1)));
3638 /* Make range 0 be the range that starts first, or ends last if they
3639 start at the same value. Swap them if it isn't. */
3640 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3643 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3644 high1, 1, high0, 1))))
3646 temp = in0_p, in0_p = in1_p, in1_p = temp;
3647 tem = low0, low0 = low1, low1 = tem;
3648 tem = high0, high0 = high1, high1 = tem;
3651 /* Now flag two cases, whether the ranges are disjoint or whether the
3652 second range is totally subsumed in the first. Note that the tests
3653 below are simplified by the ones above. */
3654 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3655 high0, 1, low1, 0));
3656 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3657 high1, 1, high0, 1));
3659 /* We now have four cases, depending on whether we are including or
3660 excluding the two ranges. */
3663 /* If they don't overlap, the result is false. If the second range
3664 is a subset it is the result. Otherwise, the range is from the start
3665 of the second to the end of the first. */
3667 in_p = 0, low = high = 0;
3669 in_p = 1, low = low1, high = high1;
3671 in_p = 1, low = low1, high = high0;
3674 else if (in0_p && ! in1_p)
3676 /* If they don't overlap, the result is the first range. If they are
3677 equal, the result is false. If the second range is a subset of the
3678 first, and the ranges begin at the same place, we go from just after
3679 the end of the first range to the end of the second. If the second
3680 range is not a subset of the first, or if it is a subset and both
3681 ranges end at the same place, the range starts at the start of the
3682 first range and ends just before the second range.
3683 Otherwise, we can't describe this as a single range. */
3685 in_p = 1, low = low0, high = high0;
3686 else if (lowequal && highequal)
3687 in_p = 0, low = high = 0;
3688 else if (subset && lowequal)
3690 in_p = 1, high = high0;
3691 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3692 integer_one_node, 0);
3694 else if (! subset || highequal)
3696 in_p = 1, low = low0;
3697 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3698 integer_one_node, 0);
3704 else if (! in0_p && in1_p)
3706 /* If they don't overlap, the result is the second range. If the second
3707 is a subset of the first, the result is false. Otherwise,
3708 the range starts just after the first range and ends at the
3709 end of the second. */
3711 in_p = 1, low = low1, high = high1;
3712 else if (subset || highequal)
3713 in_p = 0, low = high = 0;
3716 in_p = 1, high = high1;
3717 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3718 integer_one_node, 0);
3724 /* The case where we are excluding both ranges. Here the complex case
3725 is if they don't overlap. In that case, the only time we have a
3726 range is if they are adjacent. If the second is a subset of the
3727 first, the result is the first. Otherwise, the range to exclude
3728 starts at the beginning of the first range and ends at the end of the
3732 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3733 range_binop (PLUS_EXPR, NULL_TREE,
3735 integer_one_node, 1),
3737 in_p = 0, low = low0, high = high1;
3742 in_p = 0, low = low0, high = high0;
3744 in_p = 0, low = low0, high = high1;
3747 *pin_p = in_p, *plow = low, *phigh = high;
3751 /* EXP is some logical combination of boolean tests. See if we can
3752 merge it into some range test. Return the new tree if so. */
3755 fold_range_test (exp)
3758 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3759 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3760 int in0_p, in1_p, in_p;
3761 tree low0, low1, low, high0, high1, high;
3762 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3763 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3766 /* If this is an OR operation, invert both sides; we will invert
3767 again at the end. */
3769 in0_p = ! in0_p, in1_p = ! in1_p;
3771 /* If both expressions are the same, if we can merge the ranges, and we
3772 can build the range test, return it or it inverted. If one of the
3773 ranges is always true or always false, consider it to be the same
3774 expression as the other. */
3775 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3776 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3778 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3780 : rhs != 0 ? rhs : integer_zero_node,
3782 return or_op ? invert_truthvalue (tem) : tem;
3784 /* On machines where the branch cost is expensive, if this is a
3785 short-circuited branch and the underlying object on both sides
3786 is the same, make a non-short-circuit operation. */
3787 else if (BRANCH_COST >= 2
3788 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3789 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3790 && operand_equal_p (lhs, rhs, 0))
3792 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3793 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3794 which cases we can't do this. */
3795 if (simple_operand_p (lhs))
3796 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3797 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3798 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3799 TREE_OPERAND (exp, 1));
3801 else if (global_bindings_p () == 0
3802 && ! contains_placeholder_p (lhs))
3804 tree common = save_expr (lhs);
3806 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3807 or_op ? ! in0_p : in0_p,
3809 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3810 or_op ? ! in1_p : in1_p,
3812 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3813 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3814 TREE_TYPE (exp), lhs, rhs);
3821 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3822 bit value. Arrange things so the extra bits will be set to zero if and
3823 only if C is signed-extended to its full width. If MASK is nonzero,
3824 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3827 unextend (c, p, unsignedp, mask)
3833 tree type = TREE_TYPE (c);
3834 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3837 if (p == modesize || unsignedp)
3840 /* We work by getting just the sign bit into the low-order bit, then
3841 into the high-order bit, then sign-extend. We then XOR that value
3843 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3844 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3846 /* We must use a signed type in order to get an arithmetic right shift.
3847 However, we must also avoid introducing accidental overflows, so that
3848 a subsequent call to integer_zerop will work. Hence we must
3849 do the type conversion here. At this point, the constant is either
3850 zero or one, and the conversion to a signed type can never overflow.
3851 We could get an overflow if this conversion is done anywhere else. */
3852 if (TREE_UNSIGNED (type))
3853 temp = convert (signed_type (type), temp);
3855 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3856 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3858 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3859 /* If necessary, convert the type back to match the type of C. */
3860 if (TREE_UNSIGNED (type))
3861 temp = convert (type, temp);
3863 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3866 /* Find ways of folding logical expressions of LHS and RHS:
3867 Try to merge two comparisons to the same innermost item.
3868 Look for range tests like "ch >= '0' && ch <= '9'".
3869 Look for combinations of simple terms on machines with expensive branches
3870 and evaluate the RHS unconditionally.
3872 For example, if we have p->a == 2 && p->b == 4 and we can make an
3873 object large enough to span both A and B, we can do this with a comparison
3874 against the object ANDed with the a mask.
3876 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3877 operations to do this with one comparison.
3879 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3880 function and the one above.
3882 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3883 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3885 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3888 We return the simplified tree or 0 if no optimization is possible. */
3891 fold_truthop (code, truth_type, lhs, rhs)
3892 enum tree_code code;
3893 tree truth_type, lhs, rhs;
3895 /* If this is the "or" of two comparisons, we can do something if
3896 the comparisons are NE_EXPR. If this is the "and", we can do something
3897 if the comparisons are EQ_EXPR. I.e.,
3898 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3900 WANTED_CODE is this operation code. For single bit fields, we can
3901 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3902 comparison for one-bit fields. */
3904 enum tree_code wanted_code;
3905 enum tree_code lcode, rcode;
3906 tree ll_arg, lr_arg, rl_arg, rr_arg;
3907 tree ll_inner, lr_inner, rl_inner, rr_inner;
3908 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3909 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3910 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3911 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3912 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3913 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3914 enum machine_mode lnmode, rnmode;
3915 tree ll_mask, lr_mask, rl_mask, rr_mask;
3916 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3917 tree l_const, r_const;
3918 tree lntype, rntype, result;
3919 int first_bit, end_bit;
3922 /* Start by getting the comparison codes. Fail if anything is volatile.
3923 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3924 it were surrounded with a NE_EXPR. */
3926 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3929 lcode = TREE_CODE (lhs);
3930 rcode = TREE_CODE (rhs);
3932 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3933 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3935 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3936 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3938 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3941 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3942 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3944 ll_arg = TREE_OPERAND (lhs, 0);
3945 lr_arg = TREE_OPERAND (lhs, 1);
3946 rl_arg = TREE_OPERAND (rhs, 0);
3947 rr_arg = TREE_OPERAND (rhs, 1);
3949 /* If the RHS can be evaluated unconditionally and its operands are
3950 simple, it wins to evaluate the RHS unconditionally on machines
3951 with expensive branches. In this case, this isn't a comparison
3952 that can be merged. Avoid doing this if the RHS is a floating-point
3953 comparison since those can trap. */
3955 if (BRANCH_COST >= 2
3956 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
3957 && simple_operand_p (rl_arg)
3958 && simple_operand_p (rr_arg))
3959 return build (code, truth_type, lhs, rhs);
3961 /* See if the comparisons can be merged. Then get all the parameters for
3964 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3965 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3969 ll_inner = decode_field_reference (ll_arg,
3970 &ll_bitsize, &ll_bitpos, &ll_mode,
3971 &ll_unsignedp, &volatilep, &ll_mask,
3973 lr_inner = decode_field_reference (lr_arg,
3974 &lr_bitsize, &lr_bitpos, &lr_mode,
3975 &lr_unsignedp, &volatilep, &lr_mask,
3977 rl_inner = decode_field_reference (rl_arg,
3978 &rl_bitsize, &rl_bitpos, &rl_mode,
3979 &rl_unsignedp, &volatilep, &rl_mask,
3981 rr_inner = decode_field_reference (rr_arg,
3982 &rr_bitsize, &rr_bitpos, &rr_mode,
3983 &rr_unsignedp, &volatilep, &rr_mask,
3986 /* It must be true that the inner operation on the lhs of each
3987 comparison must be the same if we are to be able to do anything.
3988 Then see if we have constants. If not, the same must be true for
3990 if (volatilep || ll_inner == 0 || rl_inner == 0
3991 || ! operand_equal_p (ll_inner, rl_inner, 0))
3994 if (TREE_CODE (lr_arg) == INTEGER_CST
3995 && TREE_CODE (rr_arg) == INTEGER_CST)
3996 l_const = lr_arg, r_const = rr_arg;
3997 else if (lr_inner == 0 || rr_inner == 0
3998 || ! operand_equal_p (lr_inner, rr_inner, 0))
4001 l_const = r_const = 0;
4003 /* If either comparison code is not correct for our logical operation,
4004 fail. However, we can convert a one-bit comparison against zero into
4005 the opposite comparison against that bit being set in the field. */
4007 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
4008 if (lcode != wanted_code)
4010 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
4012 /* Make the left operand unsigned, since we are only interested
4013 in the value of one bit. Otherwise we are doing the wrong
4022 /* This is analogous to the code for l_const above. */
4023 if (rcode != wanted_code)
4025 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
4034 /* See if we can find a mode that contains both fields being compared on
4035 the left. If we can't, fail. Otherwise, update all constants and masks
4036 to be relative to a field of that size. */
4037 first_bit = MIN (ll_bitpos, rl_bitpos);
4038 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
4039 lnmode = get_best_mode (end_bit - first_bit, first_bit,
4040 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
4042 if (lnmode == VOIDmode)
4045 lnbitsize = GET_MODE_BITSIZE (lnmode);
4046 lnbitpos = first_bit & ~ (lnbitsize - 1);
4047 lntype = type_for_size (lnbitsize, 1);
4048 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4050 if (BYTES_BIG_ENDIAN)
4052 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4053 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4056 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
4057 size_int (xll_bitpos), 0);
4058 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
4059 size_int (xrl_bitpos), 0);
4063 l_const = convert (lntype, l_const);
4064 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4065 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4066 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4067 fold (build1 (BIT_NOT_EXPR,
4071 warning ("comparison is always %d", wanted_code == NE_EXPR);
4073 return convert (truth_type,
4074 wanted_code == NE_EXPR
4075 ? integer_one_node : integer_zero_node);
4080 r_const = convert (lntype, r_const);
4081 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4082 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4083 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4084 fold (build1 (BIT_NOT_EXPR,
4088 warning ("comparison is always %d", wanted_code == NE_EXPR);
4090 return convert (truth_type,
4091 wanted_code == NE_EXPR
4092 ? integer_one_node : integer_zero_node);
4096 /* If the right sides are not constant, do the same for it. Also,
4097 disallow this optimization if a size or signedness mismatch occurs
4098 between the left and right sides. */
4101 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4102 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4103 /* Make sure the two fields on the right
4104 correspond to the left without being swapped. */
4105 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4108 first_bit = MIN (lr_bitpos, rr_bitpos);
4109 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4110 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4111 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4113 if (rnmode == VOIDmode)
4116 rnbitsize = GET_MODE_BITSIZE (rnmode);
4117 rnbitpos = first_bit & ~ (rnbitsize - 1);
4118 rntype = type_for_size (rnbitsize, 1);
4119 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4121 if (BYTES_BIG_ENDIAN)
4123 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4124 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4127 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
4128 size_int (xlr_bitpos), 0);
4129 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
4130 size_int (xrr_bitpos), 0);
4132 /* Make a mask that corresponds to both fields being compared.
4133 Do this for both items being compared. If the operands are the
4134 same size and the bits being compared are in the same position
4135 then we can do this by masking both and comparing the masked
4137 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4138 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4139 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4141 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4142 ll_unsignedp || rl_unsignedp);
4143 if (! all_ones_mask_p (ll_mask, lnbitsize))
4144 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
4146 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4147 lr_unsignedp || rr_unsignedp);
4148 if (! all_ones_mask_p (lr_mask, rnbitsize))
4149 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
4151 return build (wanted_code, truth_type, lhs, rhs);
4154 /* There is still another way we can do something: If both pairs of
4155 fields being compared are adjacent, we may be able to make a wider
4156 field containing them both.
4158 Note that we still must mask the lhs/rhs expressions. Furthermore,
4159 the mask must be shifted to account for the shift done by
4160 make_bit_field_ref. */
4161 if ((ll_bitsize + ll_bitpos == rl_bitpos
4162 && lr_bitsize + lr_bitpos == rr_bitpos)
4163 || (ll_bitpos == rl_bitpos + rl_bitsize
4164 && lr_bitpos == rr_bitpos + rr_bitsize))
4168 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4169 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4170 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4171 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4173 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4174 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4175 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4176 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4178 /* Convert to the smaller type before masking out unwanted bits. */
4180 if (lntype != rntype)
4182 if (lnbitsize > rnbitsize)
4184 lhs = convert (rntype, lhs);
4185 ll_mask = convert (rntype, ll_mask);
4188 else if (lnbitsize < rnbitsize)
4190 rhs = convert (lntype, rhs);
4191 lr_mask = convert (lntype, lr_mask);
4196 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4197 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
4199 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4200 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
4202 return build (wanted_code, truth_type, lhs, rhs);
4208 /* Handle the case of comparisons with constants. If there is something in
4209 common between the masks, those bits of the constants must be the same.
4210 If not, the condition is always false. Test for this to avoid generating
4211 incorrect code below. */
4212 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4213 if (! integer_zerop (result)
4214 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4215 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4217 if (wanted_code == NE_EXPR)
4219 warning ("`or' of unmatched not-equal tests is always 1");
4220 return convert (truth_type, integer_one_node);
4224 warning ("`and' of mutually exclusive equal-tests is always 0");
4225 return convert (truth_type, integer_zero_node);
4229 /* Construct the expression we will return. First get the component
4230 reference we will make. Unless the mask is all ones the width of
4231 that field, perform the mask operation. Then compare with the
4233 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4234 ll_unsignedp || rl_unsignedp);
4236 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4237 if (! all_ones_mask_p (ll_mask, lnbitsize))
4238 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
4240 return build (wanted_code, truth_type, result,
4241 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4244 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4248 optimize_minmax_comparison (t)
4251 tree type = TREE_TYPE (t);
4252 tree arg0 = TREE_OPERAND (t, 0);
4253 enum tree_code op_code;
4254 tree comp_const = TREE_OPERAND (t, 1);
4256 int consts_equal, consts_lt;
4259 STRIP_SIGN_NOPS (arg0);
4261 op_code = TREE_CODE (arg0);
4262 minmax_const = TREE_OPERAND (arg0, 1);
4263 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4264 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4265 inner = TREE_OPERAND (arg0, 0);
4267 /* If something does not permit us to optimize, return the original tree. */
4268 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4269 || TREE_CODE (comp_const) != INTEGER_CST
4270 || TREE_CONSTANT_OVERFLOW (comp_const)
4271 || TREE_CODE (minmax_const) != INTEGER_CST
4272 || TREE_CONSTANT_OVERFLOW (minmax_const))
4275 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4276 and GT_EXPR, doing the rest with recursive calls using logical
4278 switch (TREE_CODE (t))
4280 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4282 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4286 fold (build (TRUTH_ORIF_EXPR, type,
4287 optimize_minmax_comparison
4288 (build (EQ_EXPR, type, arg0, comp_const)),
4289 optimize_minmax_comparison
4290 (build (GT_EXPR, type, arg0, comp_const))));
4293 if (op_code == MAX_EXPR && consts_equal)
4294 /* MAX (X, 0) == 0 -> X <= 0 */
4295 return fold (build (LE_EXPR, type, inner, comp_const));
4297 else if (op_code == MAX_EXPR && consts_lt)
4298 /* MAX (X, 0) == 5 -> X == 5 */
4299 return fold (build (EQ_EXPR, type, inner, comp_const));
4301 else if (op_code == MAX_EXPR)
4302 /* MAX (X, 0) == -1 -> false */
4303 return omit_one_operand (type, integer_zero_node, inner);
4305 else if (consts_equal)
4306 /* MIN (X, 0) == 0 -> X >= 0 */
4307 return fold (build (GE_EXPR, type, inner, comp_const));
4310 /* MIN (X, 0) == 5 -> false */
4311 return omit_one_operand (type, integer_zero_node, inner);
4314 /* MIN (X, 0) == -1 -> X == -1 */
4315 return fold (build (EQ_EXPR, type, inner, comp_const));
4318 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4319 /* MAX (X, 0) > 0 -> X > 0
4320 MAX (X, 0) > 5 -> X > 5 */
4321 return fold (build (GT_EXPR, type, inner, comp_const));
4323 else if (op_code == MAX_EXPR)
4324 /* MAX (X, 0) > -1 -> true */
4325 return omit_one_operand (type, integer_one_node, inner);
4327 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4328 /* MIN (X, 0) > 0 -> false
4329 MIN (X, 0) > 5 -> false */
4330 return omit_one_operand (type, integer_zero_node, inner);
4333 /* MIN (X, 0) > -1 -> X > -1 */
4334 return fold (build (GT_EXPR, type, inner, comp_const));
4341 /* T is an integer expression that is being multiplied, divided, or taken a
4342 modulus (CODE says which and what kind of divide or modulus) by a
4343 constant C. See if we can eliminate that operation by folding it with
4344 other operations already in T. WIDE_TYPE, if non-null, is a type that
4345 should be used for the computation if wider than our type.
4347 For example, if we are dividing (X * 8) + (Y + 16) by 4, we can return
4348 (X * 2) + (Y + 4). We must, however, be assured that either the original
4349 expression would not overflow or that overflow is undefined for the type
4350 in the language in question.
4352 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4353 the machine has a multiply-accumulate insn or that this is part of an
4354 addressing calculation.
4356 If we return a non-null expression, it is an equivalent form of the
4357 original computation, but need not be in the original type. */
4360 extract_muldiv (t, c, code, wide_type)
4363 enum tree_code code;
4366 tree type = TREE_TYPE (t);
4367 enum tree_code tcode = TREE_CODE (t);
4368 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4369 > GET_MODE_SIZE (TYPE_MODE (type)))
4370 ? wide_type : type);
4372 int same_p = tcode == code;
4373 tree op0 = NULL_TREE, op1 = NULL_TREE;
4375 /* Don't deal with constants of zero here; they confuse the code below. */
4376 if (integer_zerop (c))
4379 if (TREE_CODE_CLASS (tcode) == '1')
4380 op0 = TREE_OPERAND (t, 0);
4382 if (TREE_CODE_CLASS (tcode) == '2')
4383 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4385 /* Note that we need not handle conditional operations here since fold
4386 already handles those cases. So just do arithmetic here. */
4390 /* For a constant, we can always simplify if we are a multiply
4391 or (for divide and modulus) if it is a multiple of our constant. */
4392 if (code == MULT_EXPR
4393 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4394 return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
4397 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4398 /* If op0 is an expression, and is unsigned, and the type is
4399 smaller than ctype, then we cannot widen the expression. */
4400 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
4401 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
4402 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
4403 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
4404 && TREE_UNSIGNED (TREE_TYPE (op0))
4405 && ! TYPE_IS_SIZETYPE (TREE_TYPE (op0))
4406 && (GET_MODE_SIZE (TYPE_MODE (ctype))
4407 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
4410 /* Pass the constant down and see if we can make a simplification. If
4411 we can, replace this expression with the inner simplification for
4412 possible later conversion to our or some other type. */
4413 if (0 != (t1 = extract_muldiv (op0, convert (TREE_TYPE (op0), c), code,
4414 code == MULT_EXPR ? ctype : NULL_TREE)))
4418 case NEGATE_EXPR: case ABS_EXPR:
4419 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4420 return fold (build1 (tcode, ctype, convert (ctype, t1)));
4423 case MIN_EXPR: case MAX_EXPR:
4424 /* If widening the type changes the signedness, then we can't perform
4425 this optimization as that changes the result. */
4426 if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
4429 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4430 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4431 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4433 if (tree_int_cst_sgn (c) < 0)
4434 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4436 return fold (build (tcode, ctype, convert (ctype, t1),
4437 convert (ctype, t2)));
4441 case WITH_RECORD_EXPR:
4442 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4443 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4444 TREE_OPERAND (t, 1));
4448 /* If this has not been evaluated and the operand has no side effects,
4449 we can see if we can do something inside it and make a new one.
4450 Note that this test is overly conservative since we can do this
4451 if the only reason it had side effects is that it was another
4452 similar SAVE_EXPR, but that isn't worth bothering with. */
4453 if (SAVE_EXPR_RTL (t) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
4454 && 0 != (t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code,
4456 return save_expr (t1);
4459 case LSHIFT_EXPR: case RSHIFT_EXPR:
4460 /* If the second operand is constant, this is a multiplication
4461 or floor division, by a power of two, so we can treat it that
4462 way unless the multiplier or divisor overflows. */
4463 if (TREE_CODE (op1) == INTEGER_CST
4464 /* const_binop may not detect overflow correctly,
4465 so check for it explicitly here. */
4466 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
4467 && TREE_INT_CST_HIGH (op1) == 0
4468 && 0 != (t1 = convert (ctype,
4469 const_binop (LSHIFT_EXPR, size_one_node,
4471 && ! TREE_OVERFLOW (t1))
4472 return extract_muldiv (build (tcode == LSHIFT_EXPR
4473 ? MULT_EXPR : FLOOR_DIV_EXPR,
4474 ctype, convert (ctype, op0), t1),
4475 c, code, wide_type);
4478 case PLUS_EXPR: case MINUS_EXPR:
4479 /* See if we can eliminate the operation on both sides. If we can, we
4480 can return a new PLUS or MINUS. If we can't, the only remaining
4481 cases where we can do anything are if the second operand is a
4483 t1 = extract_muldiv (op0, c, code, wide_type);
4484 t2 = extract_muldiv (op1, c, code, wide_type);
4485 if (t1 != 0 && t2 != 0)
4486 return fold (build (tcode, ctype, convert (ctype, t1),
4487 convert (ctype, t2)));
4489 /* If this was a subtraction, negate OP1 and set it to be an addition.
4490 This simplifies the logic below. */
4491 if (tcode == MINUS_EXPR)
4492 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4494 if (TREE_CODE (op1) != INTEGER_CST)
4497 /* If either OP1 or C are negative, this optimization is not safe for
4498 some of the division and remainder types while for others we need
4499 to change the code. */
4500 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4502 if (code == CEIL_DIV_EXPR)
4503 code = FLOOR_DIV_EXPR;
4504 else if (code == CEIL_MOD_EXPR)
4505 code = FLOOR_MOD_EXPR;
4506 else if (code == FLOOR_DIV_EXPR)
4507 code = CEIL_DIV_EXPR;
4508 else if (code == FLOOR_MOD_EXPR)
4509 code = CEIL_MOD_EXPR;
4510 else if (code != MULT_EXPR)
4514 /* If it's a multiply or a division/modulus operation of a multiple
4515 of our constant, do the operation and verify it doesn't overflow. */
4516 if (code == MULT_EXPR
4517 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4519 op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
4520 if (op1 == 0 || TREE_OVERFLOW (op1))
4526 /* If we have an unsigned type is not a sizetype, we cannot widen
4527 the operation since it will change the result if the original
4528 computation overflowed. */
4529 if (TREE_UNSIGNED (ctype)
4530 && ! TYPE_IS_SIZETYPE (ctype)
4534 /* If we were able to eliminate our operation from the first side,
4535 apply our operation to the second side and reform the PLUS. */
4536 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4537 return fold (build (tcode, ctype, convert (ctype, t1), op1));
4539 /* The last case is if we are a multiply. In that case, we can
4540 apply the distributive law to commute the multiply and addition
4541 if the multiplication of the constants doesn't overflow. */
4542 if (code == MULT_EXPR)
4543 return fold (build (tcode, ctype, fold (build (code, ctype,
4544 convert (ctype, op0),
4545 convert (ctype, c))),
4551 /* We have a special case here if we are doing something like
4552 (C * 8) % 4 since we know that's zero. */
4553 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4554 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4555 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4556 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4557 return omit_one_operand (type, integer_zero_node, op0);
4559 /* ... fall through ... */
4561 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4562 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4563 /* If we can extract our operation from the LHS, do so and return a
4564 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4565 do something only if the second operand is a constant. */
4567 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4568 return fold (build (tcode, ctype, convert (ctype, t1),
4569 convert (ctype, op1)));
4570 else if (tcode == MULT_EXPR && code == MULT_EXPR
4571 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4572 return fold (build (tcode, ctype, convert (ctype, op0),
4573 convert (ctype, t1)));
4574 else if (TREE_CODE (op1) != INTEGER_CST)
4577 /* If these are the same operation types, we can associate them
4578 assuming no overflow. */
4580 && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
4581 convert (ctype, c), 0))
4582 && ! TREE_OVERFLOW (t1))
4583 return fold (build (tcode, ctype, convert (ctype, op0), t1));
4585 /* If these operations "cancel" each other, we have the main
4586 optimizations of this pass, which occur when either constant is a
4587 multiple of the other, in which case we replace this with either an
4588 operation or CODE or TCODE.
4590 If we have an unsigned type that is not a sizetype, we canot do
4591 this since it will change the result if the original computation
4593 if ((! TREE_UNSIGNED (ctype)
4594 || TYPE_IS_SIZETYPE (ctype))
4595 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4596 || (tcode == MULT_EXPR
4597 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4598 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
4600 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4601 return fold (build (tcode, ctype, convert (ctype, op0),
4603 const_binop (TRUNC_DIV_EXPR,
4605 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4606 return fold (build (code, ctype, convert (ctype, op0),
4608 const_binop (TRUNC_DIV_EXPR,
4620 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4621 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4622 that we may sometimes modify the tree. */
4625 strip_compound_expr (t, s)
4629 enum tree_code code = TREE_CODE (t);
4631 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4632 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4633 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4634 return TREE_OPERAND (t, 1);
4636 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4637 don't bother handling any other types. */
4638 else if (code == COND_EXPR)
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);
4642 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4644 else if (TREE_CODE_CLASS (code) == '1')
4645 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4646 else if (TREE_CODE_CLASS (code) == '<'
4647 || TREE_CODE_CLASS (code) == '2')
4649 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4650 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4656 /* Return a node which has the indicated constant VALUE (either 0 or
4657 1), and is of the indicated TYPE. */
4660 constant_boolean_node (value, type)
4664 if (type == integer_type_node)
4665 return value ? integer_one_node : integer_zero_node;
4666 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4667 return truthvalue_conversion (value ? integer_one_node :
4671 tree t = build_int_2 (value, 0);
4673 TREE_TYPE (t) = type;
4678 /* Utility function for the following routine, to see how complex a nesting of
4679 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4680 we don't care (to avoid spending too much time on complex expressions.). */
4683 count_cond (expr, lim)
4689 if (TREE_CODE (expr) != COND_EXPR)
4694 true = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4695 false = count_cond (TREE_OPERAND (expr, 2), lim - 1 - true);
4696 return MIN (lim, 1 + true + false);
4699 /* Perform constant folding and related simplification of EXPR.
4700 The related simplifications include x*1 => x, x*0 => 0, etc.,
4701 and application of the associative law.
4702 NOP_EXPR conversions may be removed freely (as long as we
4703 are careful not to change the C type of the overall expression)
4704 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4705 but we can constant-fold them if they have constant operands. */
4711 register tree t = expr;
4712 tree t1 = NULL_TREE;
4714 tree type = TREE_TYPE (expr);
4715 register tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4716 register enum tree_code code = TREE_CODE (t);
4719 /* WINS will be nonzero when the switch is done
4720 if all operands are constant. */
4723 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4724 Likewise for a SAVE_EXPR that's already been evaluated. */
4725 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t)) != 0)
4728 /* Return right away if already constant. */
4729 if (TREE_CONSTANT (t))
4731 if (code == CONST_DECL)
4732 return DECL_INITIAL (t);
4736 #ifdef MAX_INTEGER_COMPUTATION_MODE
4737 check_max_integer_computation_mode (expr);
4740 kind = TREE_CODE_CLASS (code);
4741 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4745 /* Special case for conversion ops that can have fixed point args. */
4746 arg0 = TREE_OPERAND (t, 0);
4748 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4750 STRIP_SIGN_NOPS (arg0);
4752 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4753 subop = TREE_REALPART (arg0);
4757 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4758 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4759 && TREE_CODE (subop) != REAL_CST
4760 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4762 /* Note that TREE_CONSTANT isn't enough:
4763 static var addresses are constant but we can't
4764 do arithmetic on them. */
4767 else if (IS_EXPR_CODE_CLASS (kind) || kind == 'r')
4769 register int len = TREE_CODE_LENGTH (code);
4771 for (i = 0; i < len; i++)
4773 tree op = TREE_OPERAND (t, i);
4777 continue; /* Valid for CALL_EXPR, at least. */
4779 if (kind == '<' || code == RSHIFT_EXPR)
4781 /* Signedness matters here. Perhaps we can refine this
4783 STRIP_SIGN_NOPS (op);
4786 /* Strip any conversions that don't change the mode. */
4789 if (TREE_CODE (op) == COMPLEX_CST)
4790 subop = TREE_REALPART (op);
4794 if (TREE_CODE (subop) != INTEGER_CST
4795 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4796 && TREE_CODE (subop) != REAL_CST
4797 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4799 /* Note that TREE_CONSTANT isn't enough:
4800 static var addresses are constant but we can't
4801 do arithmetic on them. */
4811 /* If this is a commutative operation, and ARG0 is a constant, move it
4812 to ARG1 to reduce the number of tests below. */
4813 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
4814 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
4815 || code == BIT_AND_EXPR)
4816 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
4818 tem = arg0; arg0 = arg1; arg1 = tem;
4820 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
4821 TREE_OPERAND (t, 1) = tem;
4824 /* Now WINS is set as described above,
4825 ARG0 is the first operand of EXPR,
4826 and ARG1 is the second operand (if it has more than one operand).
4828 First check for cases where an arithmetic operation is applied to a
4829 compound, conditional, or comparison operation. Push the arithmetic
4830 operation inside the compound or conditional to see if any folding
4831 can then be done. Convert comparison to conditional for this purpose.
4832 The also optimizes non-constant cases that used to be done in
4835 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
4836 one of the operands is a comparison and the other is a comparison, a
4837 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
4838 code below would make the expression more complex. Change it to a
4839 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
4840 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
4842 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
4843 || code == EQ_EXPR || code == NE_EXPR)
4844 && ((truth_value_p (TREE_CODE (arg0))
4845 && (truth_value_p (TREE_CODE (arg1))
4846 || (TREE_CODE (arg1) == BIT_AND_EXPR
4847 && integer_onep (TREE_OPERAND (arg1, 1)))))
4848 || (truth_value_p (TREE_CODE (arg1))
4849 && (truth_value_p (TREE_CODE (arg0))
4850 || (TREE_CODE (arg0) == BIT_AND_EXPR
4851 && integer_onep (TREE_OPERAND (arg0, 1)))))))
4853 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
4854 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
4858 if (code == EQ_EXPR)
4859 t = invert_truthvalue (t);
4864 if (TREE_CODE_CLASS (code) == '1')
4866 if (TREE_CODE (arg0) == COMPOUND_EXPR)
4867 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4868 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
4869 else if (TREE_CODE (arg0) == COND_EXPR)
4871 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
4872 fold (build1 (code, type, TREE_OPERAND (arg0, 1))),
4873 fold (build1 (code, type, TREE_OPERAND (arg0, 2)))));
4875 /* If this was a conversion, and all we did was to move into
4876 inside the COND_EXPR, bring it back out. But leave it if
4877 it is a conversion from integer to integer and the
4878 result precision is no wider than a word since such a
4879 conversion is cheap and may be optimized away by combine,
4880 while it couldn't if it were outside the COND_EXPR. Then return
4881 so we don't get into an infinite recursion loop taking the
4882 conversion out and then back in. */
4884 if ((code == NOP_EXPR || code == CONVERT_EXPR
4885 || code == NON_LVALUE_EXPR)
4886 && TREE_CODE (t) == COND_EXPR
4887 && TREE_CODE (TREE_OPERAND (t, 1)) == code
4888 && TREE_CODE (TREE_OPERAND (t, 2)) == code
4889 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
4890 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
4891 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
4893 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
4894 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
4895 t = build1 (code, type,
4897 TREE_TYPE (TREE_OPERAND
4898 (TREE_OPERAND (t, 1), 0)),
4899 TREE_OPERAND (t, 0),
4900 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
4901 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
4904 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
4905 return fold (build (COND_EXPR, type, arg0,
4906 fold (build1 (code, type, integer_one_node)),
4907 fold (build1 (code, type, integer_zero_node))));
4909 else if (TREE_CODE_CLASS (code) == '2'
4910 || TREE_CODE_CLASS (code) == '<')
4912 if (TREE_CODE (arg1) == COMPOUND_EXPR)
4913 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4914 fold (build (code, type,
4915 arg0, TREE_OPERAND (arg1, 1))));
4916 else if ((TREE_CODE (arg1) == COND_EXPR
4917 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
4918 && TREE_CODE_CLASS (code) != '<'))
4919 && (TREE_CODE (arg0) != COND_EXPR
4920 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4921 && (! TREE_SIDE_EFFECTS (arg0)
4922 || (global_bindings_p () == 0
4923 && ! contains_placeholder_p (arg0))))
4925 tree test, true_value, false_value;
4926 tree lhs = 0, rhs = 0;
4928 if (TREE_CODE (arg1) == COND_EXPR)
4930 test = TREE_OPERAND (arg1, 0);
4931 true_value = TREE_OPERAND (arg1, 1);
4932 false_value = TREE_OPERAND (arg1, 2);
4936 tree testtype = TREE_TYPE (arg1);
4938 true_value = convert (testtype, integer_one_node);
4939 false_value = convert (testtype, integer_zero_node);
4942 /* If ARG0 is complex we want to make sure we only evaluate
4943 it once. Though this is only required if it is volatile, it
4944 might be more efficient even if it is not. However, if we
4945 succeed in folding one part to a constant, we do not need
4946 to make this SAVE_EXPR. Since we do this optimization
4947 primarily to see if we do end up with constant and this
4948 SAVE_EXPR interferes with later optimizations, suppressing
4949 it when we can is important.
4951 If we are not in a function, we can't make a SAVE_EXPR, so don't
4952 try to do so. Don't try to see if the result is a constant
4953 if an arm is a COND_EXPR since we get exponential behavior
4956 if (TREE_CODE (arg0) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4957 && global_bindings_p () == 0
4958 && ((TREE_CODE (arg0) != VAR_DECL
4959 && TREE_CODE (arg0) != PARM_DECL)
4960 || TREE_SIDE_EFFECTS (arg0)))
4962 if (TREE_CODE (true_value) != COND_EXPR)
4963 lhs = fold (build (code, type, arg0, true_value));
4965 if (TREE_CODE (false_value) != COND_EXPR)
4966 rhs = fold (build (code, type, arg0, false_value));
4968 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4969 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4970 arg0 = save_expr (arg0), lhs = rhs = 0;
4974 lhs = fold (build (code, type, arg0, true_value));
4976 rhs = fold (build (code, type, arg0, false_value));
4978 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4980 if (TREE_CODE (arg0) == SAVE_EXPR)
4981 return build (COMPOUND_EXPR, type,
4982 convert (void_type_node, arg0),
4983 strip_compound_expr (test, arg0));
4985 return convert (type, test);
4988 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
4989 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4990 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4991 else if ((TREE_CODE (arg0) == COND_EXPR
4992 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
4993 && TREE_CODE_CLASS (code) != '<'))
4994 && (TREE_CODE (arg1) != COND_EXPR
4995 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4996 && (! TREE_SIDE_EFFECTS (arg1)
4997 || (global_bindings_p () == 0
4998 && ! contains_placeholder_p (arg1))))
5000 tree test, true_value, false_value;
5001 tree lhs = 0, rhs = 0;
5003 if (TREE_CODE (arg0) == COND_EXPR)
5005 test = TREE_OPERAND (arg0, 0);
5006 true_value = TREE_OPERAND (arg0, 1);
5007 false_value = TREE_OPERAND (arg0, 2);
5011 tree testtype = TREE_TYPE (arg0);
5013 true_value = convert (testtype, integer_one_node);
5014 false_value = convert (testtype, integer_zero_node);
5017 if (TREE_CODE (arg1) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
5018 && global_bindings_p () == 0
5019 && ((TREE_CODE (arg1) != VAR_DECL
5020 && TREE_CODE (arg1) != PARM_DECL)
5021 || TREE_SIDE_EFFECTS (arg1)))
5023 if (TREE_CODE (true_value) != COND_EXPR)
5024 lhs = fold (build (code, type, true_value, arg1));
5026 if (TREE_CODE (false_value) != COND_EXPR)
5027 rhs = fold (build (code, type, false_value, arg1));
5029 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
5030 && (rhs == 0 || !TREE_CONSTANT (rhs)))
5031 arg1 = save_expr (arg1), lhs = rhs = 0;
5035 lhs = fold (build (code, type, true_value, arg1));
5038 rhs = fold (build (code, type, false_value, arg1));
5040 test = fold (build (COND_EXPR, type, test, lhs, rhs));
5041 if (TREE_CODE (arg1) == SAVE_EXPR)
5042 return build (COMPOUND_EXPR, type,
5043 convert (void_type_node, arg1),
5044 strip_compound_expr (test, arg1));
5046 return convert (type, test);
5049 else if (TREE_CODE_CLASS (code) == '<'
5050 && TREE_CODE (arg0) == COMPOUND_EXPR)
5051 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5052 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5053 else if (TREE_CODE_CLASS (code) == '<'
5054 && TREE_CODE (arg1) == COMPOUND_EXPR)
5055 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5056 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
5068 return fold (DECL_INITIAL (t));
5073 case FIX_TRUNC_EXPR:
5074 /* Other kinds of FIX are not handled properly by fold_convert. */
5076 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
5077 return TREE_OPERAND (t, 0);
5079 /* Handle cases of two conversions in a row. */
5080 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
5081 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
5083 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5084 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
5085 tree final_type = TREE_TYPE (t);
5086 int inside_int = INTEGRAL_TYPE_P (inside_type);
5087 int inside_ptr = POINTER_TYPE_P (inside_type);
5088 int inside_float = FLOAT_TYPE_P (inside_type);
5089 unsigned int inside_prec = TYPE_PRECISION (inside_type);
5090 int inside_unsignedp = TREE_UNSIGNED (inside_type);
5091 int inter_int = INTEGRAL_TYPE_P (inter_type);
5092 int inter_ptr = POINTER_TYPE_P (inter_type);
5093 int inter_float = FLOAT_TYPE_P (inter_type);
5094 unsigned int inter_prec = TYPE_PRECISION (inter_type);
5095 int inter_unsignedp = TREE_UNSIGNED (inter_type);
5096 int final_int = INTEGRAL_TYPE_P (final_type);
5097 int final_ptr = POINTER_TYPE_P (final_type);
5098 int final_float = FLOAT_TYPE_P (final_type);
5099 unsigned int final_prec = TYPE_PRECISION (final_type);
5100 int final_unsignedp = TREE_UNSIGNED (final_type);
5102 /* In addition to the cases of two conversions in a row
5103 handled below, if we are converting something to its own
5104 type via an object of identical or wider precision, neither
5105 conversion is needed. */
5106 if (inside_type == final_type
5107 && ((inter_int && final_int) || (inter_float && final_float))
5108 && inter_prec >= final_prec)
5109 return TREE_OPERAND (TREE_OPERAND (t, 0), 0);
5111 /* Likewise, if the intermediate and final types are either both
5112 float or both integer, we don't need the middle conversion if
5113 it is wider than the final type and doesn't change the signedness
5114 (for integers). Avoid this if the final type is a pointer
5115 since then we sometimes need the inner conversion. Likewise if
5116 the outer has a precision not equal to the size of its mode. */
5117 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
5118 || (inter_float && inside_float))
5119 && inter_prec >= inside_prec
5120 && (inter_float || inter_unsignedp == inside_unsignedp)
5121 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5122 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5124 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5126 /* If we have a sign-extension of a zero-extended value, we can
5127 replace that by a single zero-extension. */
5128 if (inside_int && inter_int && final_int
5129 && inside_prec < inter_prec && inter_prec < final_prec
5130 && inside_unsignedp && !inter_unsignedp)
5131 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5133 /* Two conversions in a row are not needed unless:
5134 - some conversion is floating-point (overstrict for now), or
5135 - the intermediate type is narrower than both initial and
5137 - the intermediate type and innermost type differ in signedness,
5138 and the outermost type is wider than the intermediate, or
5139 - the initial type is a pointer type and the precisions of the
5140 intermediate and final types differ, or
5141 - the final type is a pointer type and the precisions of the
5142 initial and intermediate types differ. */
5143 if (! inside_float && ! inter_float && ! final_float
5144 && (inter_prec > inside_prec || inter_prec > final_prec)
5145 && ! (inside_int && inter_int
5146 && inter_unsignedp != inside_unsignedp
5147 && inter_prec < final_prec)
5148 && ((inter_unsignedp && inter_prec > inside_prec)
5149 == (final_unsignedp && final_prec > inter_prec))
5150 && ! (inside_ptr && inter_prec != final_prec)
5151 && ! (final_ptr && inside_prec != inter_prec)
5152 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5153 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5155 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5158 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5159 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5160 /* Detect assigning a bitfield. */
5161 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5162 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5164 /* Don't leave an assignment inside a conversion
5165 unless assigning a bitfield. */
5166 tree prev = TREE_OPERAND (t, 0);
5167 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5168 /* First do the assignment, then return converted constant. */
5169 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5175 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
5178 return fold_convert (t, arg0);
5180 #if 0 /* This loses on &"foo"[0]. */
5185 /* Fold an expression like: "foo"[2] */
5186 if (TREE_CODE (arg0) == STRING_CST
5187 && TREE_CODE (arg1) == INTEGER_CST
5188 && compare_tree_int (arg1, TREE_STRING_LENGTH (arg0)) < 0)
5190 t = build_int_2 (TREE_STRING_POINTER (arg0)[TREE_INT_CST_LOW (arg))], 0);
5191 TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (arg0));
5192 force_fit_type (t, 0);
5199 if (TREE_CODE (arg0) == CONSTRUCTOR)
5201 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5208 TREE_CONSTANT (t) = wins;
5214 if (TREE_CODE (arg0) == INTEGER_CST)
5216 unsigned HOST_WIDE_INT low;
5218 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5219 TREE_INT_CST_HIGH (arg0),
5221 t = build_int_2 (low, high);
5222 TREE_TYPE (t) = type;
5224 = (TREE_OVERFLOW (arg0)
5225 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
5226 TREE_CONSTANT_OVERFLOW (t)
5227 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5229 else if (TREE_CODE (arg0) == REAL_CST)
5230 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5232 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5233 return TREE_OPERAND (arg0, 0);
5235 /* Convert - (a - b) to (b - a) for non-floating-point. */
5236 else if (TREE_CODE (arg0) == MINUS_EXPR
5237 && (! FLOAT_TYPE_P (type) || flag_fast_math))
5238 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
5239 TREE_OPERAND (arg0, 0));
5246 if (TREE_CODE (arg0) == INTEGER_CST)
5248 if (! TREE_UNSIGNED (type)
5249 && TREE_INT_CST_HIGH (arg0) < 0)
5251 unsigned HOST_WIDE_INT low;
5253 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5254 TREE_INT_CST_HIGH (arg0),
5256 t = build_int_2 (low, high);
5257 TREE_TYPE (t) = type;
5259 = (TREE_OVERFLOW (arg0)
5260 | force_fit_type (t, overflow));
5261 TREE_CONSTANT_OVERFLOW (t)
5262 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5265 else if (TREE_CODE (arg0) == REAL_CST)
5267 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5268 t = build_real (type,
5269 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5272 else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR)
5273 return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
5277 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5278 return convert (type, arg0);
5279 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5280 return build (COMPLEX_EXPR, type,
5281 TREE_OPERAND (arg0, 0),
5282 negate_expr (TREE_OPERAND (arg0, 1)));
5283 else if (TREE_CODE (arg0) == COMPLEX_CST)
5284 return build_complex (type, TREE_OPERAND (arg0, 0),
5285 negate_expr (TREE_OPERAND (arg0, 1)));
5286 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5287 return fold (build (TREE_CODE (arg0), type,
5288 fold (build1 (CONJ_EXPR, type,
5289 TREE_OPERAND (arg0, 0))),
5290 fold (build1 (CONJ_EXPR,
5291 type, TREE_OPERAND (arg0, 1)))));
5292 else if (TREE_CODE (arg0) == CONJ_EXPR)
5293 return TREE_OPERAND (arg0, 0);
5299 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5300 ~ TREE_INT_CST_HIGH (arg0));
5301 TREE_TYPE (t) = type;
5302 force_fit_type (t, 0);
5303 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5304 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5306 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5307 return TREE_OPERAND (arg0, 0);
5311 /* A + (-B) -> A - B */
5312 if (TREE_CODE (arg1) == NEGATE_EXPR)
5313 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5314 /* (-A) + B -> B - A */
5315 if (TREE_CODE (arg0) == NEGATE_EXPR)
5316 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5317 else if (! FLOAT_TYPE_P (type))
5319 if (integer_zerop (arg1))
5320 return non_lvalue (convert (type, arg0));
5322 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5323 with a constant, and the two constants have no bits in common,
5324 we should treat this as a BIT_IOR_EXPR since this may produce more
5326 if (TREE_CODE (arg0) == BIT_AND_EXPR
5327 && TREE_CODE (arg1) == BIT_AND_EXPR
5328 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5329 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5330 && integer_zerop (const_binop (BIT_AND_EXPR,
5331 TREE_OPERAND (arg0, 1),
5332 TREE_OPERAND (arg1, 1), 0)))
5334 code = BIT_IOR_EXPR;
5338 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5339 (plus (plus (mult) (mult)) (foo)) so that we can
5340 take advantage of the factoring cases below. */
5341 if ((TREE_CODE (arg0) == PLUS_EXPR
5342 && TREE_CODE (arg1) == MULT_EXPR)
5343 || (TREE_CODE (arg1) == PLUS_EXPR
5344 && TREE_CODE (arg0) == MULT_EXPR))
5346 tree parg0, parg1, parg, marg;
5348 if (TREE_CODE (arg0) == PLUS_EXPR)
5349 parg = arg0, marg = arg1;
5351 parg = arg1, marg = arg0;
5352 parg0 = TREE_OPERAND (parg, 0);
5353 parg1 = TREE_OPERAND (parg, 1);
5357 if (TREE_CODE (parg0) == MULT_EXPR
5358 && TREE_CODE (parg1) != MULT_EXPR)
5359 return fold (build (PLUS_EXPR, type,
5360 fold (build (PLUS_EXPR, type, parg0, marg)),
5362 if (TREE_CODE (parg0) != MULT_EXPR
5363 && TREE_CODE (parg1) == MULT_EXPR)
5364 return fold (build (PLUS_EXPR, type,
5365 fold (build (PLUS_EXPR, type, parg1, marg)),
5369 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5371 tree arg00, arg01, arg10, arg11;
5372 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5374 /* (A * C) + (B * C) -> (A+B) * C.
5375 We are most concerned about the case where C is a constant,
5376 but other combinations show up during loop reduction. Since
5377 it is not difficult, try all four possibilities. */
5379 arg00 = TREE_OPERAND (arg0, 0);
5380 arg01 = TREE_OPERAND (arg0, 1);
5381 arg10 = TREE_OPERAND (arg1, 0);
5382 arg11 = TREE_OPERAND (arg1, 1);
5385 if (operand_equal_p (arg01, arg11, 0))
5386 same = arg01, alt0 = arg00, alt1 = arg10;
5387 else if (operand_equal_p (arg00, arg10, 0))
5388 same = arg00, alt0 = arg01, alt1 = arg11;
5389 else if (operand_equal_p (arg00, arg11, 0))
5390 same = arg00, alt0 = arg01, alt1 = arg10;
5391 else if (operand_equal_p (arg01, arg10, 0))
5392 same = arg01, alt0 = arg00, alt1 = arg11;
5394 /* No identical multiplicands; see if we can find a common
5395 power-of-two factor in non-power-of-two multiplies. This
5396 can help in multi-dimensional array access. */
5397 else if (TREE_CODE (arg01) == INTEGER_CST
5398 && TREE_CODE (arg11) == INTEGER_CST
5399 && TREE_INT_CST_HIGH (arg01) == 0
5400 && TREE_INT_CST_HIGH (arg11) == 0)
5402 HOST_WIDE_INT int01, int11, tmp;
5403 int01 = TREE_INT_CST_LOW (arg01);
5404 int11 = TREE_INT_CST_LOW (arg11);
5406 /* Move min of absolute values to int11. */
5407 if ((int01 >= 0 ? int01 : -int01)
5408 < (int11 >= 0 ? int11 : -int11))
5410 tmp = int01, int01 = int11, int11 = tmp;
5411 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5412 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5415 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5417 alt0 = fold (build (MULT_EXPR, type, arg00,
5418 build_int_2 (int01 / int11, 0)));
5425 return fold (build (MULT_EXPR, type,
5426 fold (build (PLUS_EXPR, type, alt0, alt1)),
5430 /* In IEEE floating point, x+0 may not equal x. */
5431 else if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5433 && real_zerop (arg1))
5434 return non_lvalue (convert (type, arg0));
5435 /* x+(-0) equals x, even for IEEE. */
5436 else if (TREE_CODE (arg1) == REAL_CST
5437 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
5438 return non_lvalue (convert (type, arg0));
5441 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5442 is a rotate of A by C1 bits. */
5443 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5444 is a rotate of A by B bits. */
5446 register enum tree_code code0, code1;
5447 code0 = TREE_CODE (arg0);
5448 code1 = TREE_CODE (arg1);
5449 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5450 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5451 && operand_equal_p (TREE_OPERAND (arg0, 0),
5452 TREE_OPERAND (arg1, 0), 0)
5453 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5455 register tree tree01, tree11;
5456 register enum tree_code code01, code11;
5458 tree01 = TREE_OPERAND (arg0, 1);
5459 tree11 = TREE_OPERAND (arg1, 1);
5460 STRIP_NOPS (tree01);
5461 STRIP_NOPS (tree11);
5462 code01 = TREE_CODE (tree01);
5463 code11 = TREE_CODE (tree11);
5464 if (code01 == INTEGER_CST
5465 && code11 == INTEGER_CST
5466 && TREE_INT_CST_HIGH (tree01) == 0
5467 && TREE_INT_CST_HIGH (tree11) == 0
5468 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5469 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5470 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5471 code0 == LSHIFT_EXPR ? tree01 : tree11);
5472 else if (code11 == MINUS_EXPR)
5474 tree tree110, tree111;
5475 tree110 = TREE_OPERAND (tree11, 0);
5476 tree111 = TREE_OPERAND (tree11, 1);
5477 STRIP_NOPS (tree110);
5478 STRIP_NOPS (tree111);
5479 if (TREE_CODE (tree110) == INTEGER_CST
5480 && 0 == compare_tree_int (tree110,
5482 (TREE_TYPE (TREE_OPERAND
5484 && operand_equal_p (tree01, tree111, 0))
5485 return build ((code0 == LSHIFT_EXPR
5488 type, TREE_OPERAND (arg0, 0), tree01);
5490 else if (code01 == MINUS_EXPR)
5492 tree tree010, tree011;
5493 tree010 = TREE_OPERAND (tree01, 0);
5494 tree011 = TREE_OPERAND (tree01, 1);
5495 STRIP_NOPS (tree010);
5496 STRIP_NOPS (tree011);
5497 if (TREE_CODE (tree010) == INTEGER_CST
5498 && 0 == compare_tree_int (tree010,
5500 (TREE_TYPE (TREE_OPERAND
5502 && operand_equal_p (tree11, tree011, 0))
5503 return build ((code0 != LSHIFT_EXPR
5506 type, TREE_OPERAND (arg0, 0), tree11);
5512 /* In most languages, can't associate operations on floats through
5513 parentheses. Rather than remember where the parentheses were, we
5514 don't associate floats at all. It shouldn't matter much. However,
5515 associating multiplications is only very slightly inaccurate, so do
5516 that if -ffast-math is specified. */
5519 && (! FLOAT_TYPE_P (type)
5520 || (flag_fast_math && code != MULT_EXPR)))
5522 tree var0, con0, lit0, var1, con1, lit1;
5524 /* Split both trees into variables, constants, and literals. Then
5525 associate each group together, the constants with literals,
5526 then the result with variables. This increases the chances of
5527 literals being recombined later and of generating relocatable
5528 expressions for the sum of a constant and literal. */
5529 var0 = split_tree (arg0, code, &con0, &lit0, 0);
5530 var1 = split_tree (arg1, code, &con1, &lit1, code == MINUS_EXPR);
5532 /* Only do something if we found more than two objects. Otherwise,
5533 nothing has changed and we risk infinite recursion. */
5534 if (2 < ((var0 != 0) + (var1 != 0) + (con0 != 0) + (con1 != 0)
5535 + (lit0 != 0) + (lit1 != 0)))
5537 var0 = associate_trees (var0, var1, code, type);
5538 con0 = associate_trees (con0, con1, code, type);
5539 lit0 = associate_trees (lit0, lit1, code, type);
5540 con0 = associate_trees (con0, lit0, code, type);
5541 return convert (type, associate_trees (var0, con0, code, type));
5546 #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
5547 if (TREE_CODE (arg1) == REAL_CST)
5549 #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
5551 t1 = const_binop (code, arg0, arg1, 0);
5552 if (t1 != NULL_TREE)
5554 /* The return value should always have
5555 the same type as the original expression. */
5556 if (TREE_TYPE (t1) != TREE_TYPE (t))
5557 t1 = convert (TREE_TYPE (t), t1);
5564 /* A - (-B) -> A + B */
5565 if (TREE_CODE (arg1) == NEGATE_EXPR)
5566 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5567 /* (-A) - CST -> (-CST) - A for floating point (what about ints ?) */
5568 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
5570 fold (build (MINUS_EXPR, type,
5571 build_real (TREE_TYPE (arg1),
5572 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1))),
5573 TREE_OPERAND (arg0, 0)));
5575 if (! FLOAT_TYPE_P (type))
5577 if (! wins && integer_zerop (arg0))
5578 return convert (type, negate_expr (arg1));
5579 if (integer_zerop (arg1))
5580 return non_lvalue (convert (type, arg0));
5582 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5583 about the case where C is a constant, just try one of the
5584 four possibilities. */
5586 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5587 && operand_equal_p (TREE_OPERAND (arg0, 1),
5588 TREE_OPERAND (arg1, 1), 0))
5589 return fold (build (MULT_EXPR, type,
5590 fold (build (MINUS_EXPR, type,
5591 TREE_OPERAND (arg0, 0),
5592 TREE_OPERAND (arg1, 0))),
5593 TREE_OPERAND (arg0, 1)));
5596 else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5599 /* Except with IEEE floating point, 0-x equals -x. */
5600 if (! wins && real_zerop (arg0))
5601 return convert (type, negate_expr (arg1));
5602 /* Except with IEEE floating point, x-0 equals x. */
5603 if (real_zerop (arg1))
5604 return non_lvalue (convert (type, arg0));
5607 /* Fold &x - &x. This can happen from &x.foo - &x.
5608 This is unsafe for certain floats even in non-IEEE formats.
5609 In IEEE, it is unsafe because it does wrong for NaNs.
5610 Also note that operand_equal_p is always false if an operand
5613 if ((! FLOAT_TYPE_P (type) || flag_fast_math)
5614 && operand_equal_p (arg0, arg1, 0))
5615 return convert (type, integer_zero_node);
5620 /* (-A) * (-B) -> A * B */
5621 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5622 return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
5623 TREE_OPERAND (arg1, 0)));
5625 if (! FLOAT_TYPE_P (type))
5627 if (integer_zerop (arg1))
5628 return omit_one_operand (type, arg1, arg0);
5629 if (integer_onep (arg1))
5630 return non_lvalue (convert (type, arg0));
5632 /* (a * (1 << b)) is (a << b) */
5633 if (TREE_CODE (arg1) == LSHIFT_EXPR
5634 && integer_onep (TREE_OPERAND (arg1, 0)))
5635 return fold (build (LSHIFT_EXPR, type, arg0,
5636 TREE_OPERAND (arg1, 1)));
5637 if (TREE_CODE (arg0) == LSHIFT_EXPR
5638 && integer_onep (TREE_OPERAND (arg0, 0)))
5639 return fold (build (LSHIFT_EXPR, type, arg1,
5640 TREE_OPERAND (arg0, 1)));
5642 if (TREE_CODE (arg1) == INTEGER_CST
5643 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5645 return convert (type, tem);
5650 /* x*0 is 0, except for IEEE floating point. */
5651 if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5653 && real_zerop (arg1))
5654 return omit_one_operand (type, arg1, arg0);
5655 /* In IEEE floating point, x*1 is not equivalent to x for snans.
5656 However, ANSI says we can drop signals,
5657 so we can do this anyway. */
5658 if (real_onep (arg1))
5659 return non_lvalue (convert (type, arg0));
5661 if (! wins && real_twop (arg1) && global_bindings_p () == 0
5662 && ! contains_placeholder_p (arg0))
5664 tree arg = save_expr (arg0);
5665 return build (PLUS_EXPR, type, arg, arg);
5672 if (integer_all_onesp (arg1))
5673 return omit_one_operand (type, arg1, arg0);
5674 if (integer_zerop (arg1))
5675 return non_lvalue (convert (type, arg0));
5676 t1 = distribute_bit_expr (code, type, arg0, arg1);
5677 if (t1 != NULL_TREE)
5680 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
5682 This results in more efficient code for machines without a NAND
5683 instruction. Combine will canonicalize to the first form
5684 which will allow use of NAND instructions provided by the
5685 backend if they exist. */
5686 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5687 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5689 return fold (build1 (BIT_NOT_EXPR, type,
5690 build (BIT_AND_EXPR, type,
5691 TREE_OPERAND (arg0, 0),
5692 TREE_OPERAND (arg1, 0))));
5695 /* See if this can be simplified into a rotate first. If that
5696 is unsuccessful continue in the association code. */
5700 if (integer_zerop (arg1))
5701 return non_lvalue (convert (type, arg0));
5702 if (integer_all_onesp (arg1))
5703 return fold (build1 (BIT_NOT_EXPR, type, arg0));
5705 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
5706 with a constant, and the two constants have no bits in common,
5707 we should treat this as a BIT_IOR_EXPR since this may produce more
5709 if (TREE_CODE (arg0) == BIT_AND_EXPR
5710 && TREE_CODE (arg1) == BIT_AND_EXPR
5711 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5712 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5713 && integer_zerop (const_binop (BIT_AND_EXPR,
5714 TREE_OPERAND (arg0, 1),
5715 TREE_OPERAND (arg1, 1), 0)))
5717 code = BIT_IOR_EXPR;
5721 /* See if this can be simplified into a rotate first. If that
5722 is unsuccessful continue in the association code. */
5727 if (integer_all_onesp (arg1))
5728 return non_lvalue (convert (type, arg0));
5729 if (integer_zerop (arg1))
5730 return omit_one_operand (type, arg1, arg0);
5731 t1 = distribute_bit_expr (code, type, arg0, arg1);
5732 if (t1 != NULL_TREE)
5734 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5735 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == NOP_EXPR
5736 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0))))
5739 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0)));
5741 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5742 && (~TREE_INT_CST_LOW (arg0)
5743 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5744 return build1 (NOP_EXPR, type, TREE_OPERAND (arg1, 0));
5746 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
5747 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5750 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
5752 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5753 && (~TREE_INT_CST_LOW (arg1)
5754 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5755 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
5758 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
5760 This results in more efficient code for machines without a NOR
5761 instruction. Combine will canonicalize to the first form
5762 which will allow use of NOR instructions provided by the
5763 backend if they exist. */
5764 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5765 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5767 return fold (build1 (BIT_NOT_EXPR, type,
5768 build (BIT_IOR_EXPR, type,
5769 TREE_OPERAND (arg0, 0),
5770 TREE_OPERAND (arg1, 0))));
5775 case BIT_ANDTC_EXPR:
5776 if (integer_all_onesp (arg0))
5777 return non_lvalue (convert (type, arg1));
5778 if (integer_zerop (arg0))
5779 return omit_one_operand (type, arg0, arg1);
5780 if (TREE_CODE (arg1) == INTEGER_CST)
5782 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
5783 code = BIT_AND_EXPR;
5789 /* In most cases, do nothing with a divide by zero. */
5790 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5791 #ifndef REAL_INFINITY
5792 if (TREE_CODE (arg1) == REAL_CST && real_zerop (arg1))
5795 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5797 /* (-A) / (-B) -> A / B */
5798 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5799 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
5800 TREE_OPERAND (arg1, 0)));
5802 /* In IEEE floating point, x/1 is not equivalent to x for snans.
5803 However, ANSI says we can drop signals, so we can do this anyway. */
5804 if (real_onep (arg1))
5805 return non_lvalue (convert (type, arg0));
5807 /* If ARG1 is a constant, we can convert this to a multiply by the
5808 reciprocal. This does not have the same rounding properties,
5809 so only do this if -ffast-math. We can actually always safely
5810 do it if ARG1 is a power of two, but it's hard to tell if it is
5811 or not in a portable manner. */
5812 if (TREE_CODE (arg1) == REAL_CST)
5815 && 0 != (tem = const_binop (code, build_real (type, dconst1),
5817 return fold (build (MULT_EXPR, type, arg0, tem));
5818 /* Find the reciprocal if optimizing and the result is exact. */
5822 r = TREE_REAL_CST (arg1);
5823 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
5825 tem = build_real (type, r);
5826 return fold (build (MULT_EXPR, type, arg0, tem));
5832 case TRUNC_DIV_EXPR:
5833 case ROUND_DIV_EXPR:
5834 case FLOOR_DIV_EXPR:
5836 case EXACT_DIV_EXPR:
5837 if (integer_onep (arg1))
5838 return non_lvalue (convert (type, arg0));
5839 if (integer_zerop (arg1))
5842 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
5843 operation, EXACT_DIV_EXPR.
5845 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
5846 At one time others generated faster code, it's not clear if they do
5847 after the last round to changes to the DIV code in expmed.c. */
5848 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
5849 && multiple_of_p (type, arg0, arg1))
5850 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
5852 if (TREE_CODE (arg1) == INTEGER_CST
5853 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5855 return convert (type, tem);
5860 case FLOOR_MOD_EXPR:
5861 case ROUND_MOD_EXPR:
5862 case TRUNC_MOD_EXPR:
5863 if (integer_onep (arg1))
5864 return omit_one_operand (type, integer_zero_node, arg0);
5865 if (integer_zerop (arg1))
5868 if (TREE_CODE (arg1) == INTEGER_CST
5869 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5871 return convert (type, tem);
5879 if (integer_zerop (arg1))
5880 return non_lvalue (convert (type, arg0));
5881 /* Since negative shift count is not well-defined,
5882 don't try to compute it in the compiler. */
5883 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
5885 /* Rewrite an LROTATE_EXPR by a constant into an
5886 RROTATE_EXPR by a new constant. */
5887 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
5889 TREE_SET_CODE (t, RROTATE_EXPR);
5890 code = RROTATE_EXPR;
5891 TREE_OPERAND (t, 1) = arg1
5894 convert (TREE_TYPE (arg1),
5895 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
5897 if (tree_int_cst_sgn (arg1) < 0)
5901 /* If we have a rotate of a bit operation with the rotate count and
5902 the second operand of the bit operation both constant,
5903 permute the two operations. */
5904 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5905 && (TREE_CODE (arg0) == BIT_AND_EXPR
5906 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
5907 || TREE_CODE (arg0) == BIT_IOR_EXPR
5908 || TREE_CODE (arg0) == BIT_XOR_EXPR)
5909 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5910 return fold (build (TREE_CODE (arg0), type,
5911 fold (build (code, type,
5912 TREE_OPERAND (arg0, 0), arg1)),
5913 fold (build (code, type,
5914 TREE_OPERAND (arg0, 1), arg1))));
5916 /* Two consecutive rotates adding up to the width of the mode can
5918 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5919 && TREE_CODE (arg0) == RROTATE_EXPR
5920 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5921 && TREE_INT_CST_HIGH (arg1) == 0
5922 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
5923 && ((TREE_INT_CST_LOW (arg1)
5924 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
5925 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
5926 return TREE_OPERAND (arg0, 0);
5931 if (operand_equal_p (arg0, arg1, 0))
5932 return omit_one_operand (type, arg0, arg1);
5933 if (INTEGRAL_TYPE_P (type)
5934 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
5935 return omit_one_operand (type, arg1, arg0);
5939 if (operand_equal_p (arg0, arg1, 0))
5940 return omit_one_operand (type, arg0, arg1);
5941 if (INTEGRAL_TYPE_P (type)
5942 && TYPE_MAX_VALUE (type)
5943 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
5944 return omit_one_operand (type, arg1, arg0);
5947 case TRUTH_NOT_EXPR:
5948 /* Note that the operand of this must be an int
5949 and its values must be 0 or 1.
5950 ("true" is a fixed value perhaps depending on the language,
5951 but we don't handle values other than 1 correctly yet.) */
5952 tem = invert_truthvalue (arg0);
5953 /* Avoid infinite recursion. */
5954 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
5956 return convert (type, tem);
5958 case TRUTH_ANDIF_EXPR:
5959 /* Note that the operands of this must be ints
5960 and their values must be 0 or 1.
5961 ("true" is a fixed value perhaps depending on the language.) */
5962 /* If first arg is constant zero, return it. */
5963 if (integer_zerop (arg0))
5964 return convert (type, arg0);
5965 case TRUTH_AND_EXPR:
5966 /* If either arg is constant true, drop it. */
5967 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5968 return non_lvalue (convert (type, arg1));
5969 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5970 return non_lvalue (convert (type, arg0));
5971 /* If second arg is constant zero, result is zero, but first arg
5972 must be evaluated. */
5973 if (integer_zerop (arg1))
5974 return omit_one_operand (type, arg1, arg0);
5975 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
5976 case will be handled here. */
5977 if (integer_zerop (arg0))
5978 return omit_one_operand (type, arg0, arg1);
5981 /* We only do these simplifications if we are optimizing. */
5985 /* Check for things like (A || B) && (A || C). We can convert this
5986 to A || (B && C). Note that either operator can be any of the four
5987 truth and/or operations and the transformation will still be
5988 valid. Also note that we only care about order for the
5989 ANDIF and ORIF operators. If B contains side effects, this
5990 might change the truth-value of A. */
5991 if (TREE_CODE (arg0) == TREE_CODE (arg1)
5992 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
5993 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
5994 || TREE_CODE (arg0) == TRUTH_AND_EXPR
5995 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
5996 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
5998 tree a00 = TREE_OPERAND (arg0, 0);
5999 tree a01 = TREE_OPERAND (arg0, 1);
6000 tree a10 = TREE_OPERAND (arg1, 0);
6001 tree a11 = TREE_OPERAND (arg1, 1);
6002 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
6003 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
6004 && (code == TRUTH_AND_EXPR
6005 || code == TRUTH_OR_EXPR));
6007 if (operand_equal_p (a00, a10, 0))
6008 return fold (build (TREE_CODE (arg0), type, a00,
6009 fold (build (code, type, a01, a11))));
6010 else if (commutative && operand_equal_p (a00, a11, 0))
6011 return fold (build (TREE_CODE (arg0), type, a00,
6012 fold (build (code, type, a01, a10))));
6013 else if (commutative && operand_equal_p (a01, a10, 0))
6014 return fold (build (TREE_CODE (arg0), type, a01,
6015 fold (build (code, type, a00, a11))));
6017 /* This case if tricky because we must either have commutative
6018 operators or else A10 must not have side-effects. */
6020 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
6021 && operand_equal_p (a01, a11, 0))
6022 return fold (build (TREE_CODE (arg0), type,
6023 fold (build (code, type, a00, a10)),
6027 /* See if we can build a range comparison. */
6028 if (0 != (tem = fold_range_test (t)))
6031 /* Check for the possibility of merging component references. If our
6032 lhs is another similar operation, try to merge its rhs with our
6033 rhs. Then try to merge our lhs and rhs. */
6034 if (TREE_CODE (arg0) == code
6035 && 0 != (tem = fold_truthop (code, type,
6036 TREE_OPERAND (arg0, 1), arg1)))
6037 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6039 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
6044 case TRUTH_ORIF_EXPR:
6045 /* Note that the operands of this must be ints
6046 and their values must be 0 or true.
6047 ("true" is a fixed value perhaps depending on the language.) */
6048 /* If first arg is constant true, return it. */
6049 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6050 return convert (type, arg0);
6052 /* If either arg is constant zero, drop it. */
6053 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
6054 return non_lvalue (convert (type, arg1));
6055 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1))
6056 return non_lvalue (convert (type, arg0));
6057 /* If second arg is constant true, result is true, but we must
6058 evaluate first arg. */
6059 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
6060 return omit_one_operand (type, arg1, arg0);
6061 /* Likewise for first arg, but note this only occurs here for
6063 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6064 return omit_one_operand (type, arg0, arg1);
6067 case TRUTH_XOR_EXPR:
6068 /* If either arg is constant zero, drop it. */
6069 if (integer_zerop (arg0))
6070 return non_lvalue (convert (type, arg1));
6071 if (integer_zerop (arg1))
6072 return non_lvalue (convert (type, arg0));
6073 /* If either arg is constant true, this is a logical inversion. */
6074 if (integer_onep (arg0))
6075 return non_lvalue (convert (type, invert_truthvalue (arg1)));
6076 if (integer_onep (arg1))
6077 return non_lvalue (convert (type, invert_truthvalue (arg0)));
6086 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
6088 /* (-a) CMP (-b) -> b CMP a */
6089 if (TREE_CODE (arg0) == NEGATE_EXPR
6090 && TREE_CODE (arg1) == NEGATE_EXPR)
6091 return fold (build (code, type, TREE_OPERAND (arg1, 0),
6092 TREE_OPERAND (arg0, 0)));
6093 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6094 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
6097 (swap_tree_comparison (code), type,
6098 TREE_OPERAND (arg0, 0),
6099 build_real (TREE_TYPE (arg1),
6100 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1)))));
6101 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6102 /* a CMP (-0) -> a CMP 0 */
6103 if (TREE_CODE (arg1) == REAL_CST
6104 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
6105 return fold (build (code, type, arg0,
6106 build_real (TREE_TYPE (arg1), dconst0)));
6109 /* If one arg is a constant integer, put it last. */
6110 if (TREE_CODE (arg0) == INTEGER_CST
6111 && TREE_CODE (arg1) != INTEGER_CST)
6113 TREE_OPERAND (t, 0) = arg1;
6114 TREE_OPERAND (t, 1) = arg0;
6115 arg0 = TREE_OPERAND (t, 0);
6116 arg1 = TREE_OPERAND (t, 1);
6117 code = swap_tree_comparison (code);
6118 TREE_SET_CODE (t, code);
6121 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6122 First, see if one arg is constant; find the constant arg
6123 and the other one. */
6125 tree constop = 0, varop = NULL_TREE;
6126 int constopnum = -1;
6128 if (TREE_CONSTANT (arg1))
6129 constopnum = 1, constop = arg1, varop = arg0;
6130 if (TREE_CONSTANT (arg0))
6131 constopnum = 0, constop = arg0, varop = arg1;
6133 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
6135 /* This optimization is invalid for ordered comparisons
6136 if CONST+INCR overflows or if foo+incr might overflow.
6137 This optimization is invalid for floating point due to rounding.
6138 For pointer types we assume overflow doesn't happen. */
6139 if (POINTER_TYPE_P (TREE_TYPE (varop))
6140 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6141 && (code == EQ_EXPR || code == NE_EXPR)))
6144 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
6145 constop, TREE_OPERAND (varop, 1)));
6147 /* Do not overwrite the current varop to be a preincrement,
6148 create a new node so that we won't confuse our caller who
6149 might create trees and throw them away, reusing the
6150 arguments that they passed to build. This shows up in
6151 the THEN or ELSE parts of ?: being postincrements. */
6152 varop = build (PREINCREMENT_EXPR, TREE_TYPE (varop),
6153 TREE_OPERAND (varop, 0),
6154 TREE_OPERAND (varop, 1));
6156 /* If VAROP is a reference to a bitfield, we must mask
6157 the constant by the width of the field. */
6158 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6159 && DECL_BIT_FIELD(TREE_OPERAND
6160 (TREE_OPERAND (varop, 0), 1)))
6163 = TREE_INT_CST_LOW (DECL_SIZE
6165 (TREE_OPERAND (varop, 0), 1)));
6166 tree mask, unsigned_type;
6167 unsigned int precision;
6168 tree folded_compare;
6170 /* First check whether the comparison would come out
6171 always the same. If we don't do that we would
6172 change the meaning with the masking. */
6173 if (constopnum == 0)
6174 folded_compare = fold (build (code, type, constop,
6175 TREE_OPERAND (varop, 0)));
6177 folded_compare = fold (build (code, type,
6178 TREE_OPERAND (varop, 0),
6180 if (integer_zerop (folded_compare)
6181 || integer_onep (folded_compare))
6182 return omit_one_operand (type, folded_compare, varop);
6184 unsigned_type = type_for_size (size, 1);
6185 precision = TYPE_PRECISION (unsigned_type);
6186 mask = build_int_2 (~0, ~0);
6187 TREE_TYPE (mask) = unsigned_type;
6188 force_fit_type (mask, 0);
6189 mask = const_binop (RSHIFT_EXPR, mask,
6190 size_int (precision - size), 0);
6191 newconst = fold (build (BIT_AND_EXPR,
6192 TREE_TYPE (varop), newconst,
6193 convert (TREE_TYPE (varop),
6197 t = build (code, type,
6198 (constopnum == 0) ? newconst : varop,
6199 (constopnum == 1) ? newconst : varop);
6203 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
6205 if (POINTER_TYPE_P (TREE_TYPE (varop))
6206 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6207 && (code == EQ_EXPR || code == NE_EXPR)))
6210 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
6211 constop, TREE_OPERAND (varop, 1)));
6213 /* Do not overwrite the current varop to be a predecrement,
6214 create a new node so that we won't confuse our caller who
6215 might create trees and throw them away, reusing the
6216 arguments that they passed to build. This shows up in
6217 the THEN or ELSE parts of ?: being postdecrements. */
6218 varop = build (PREDECREMENT_EXPR, TREE_TYPE (varop),
6219 TREE_OPERAND (varop, 0),
6220 TREE_OPERAND (varop, 1));
6222 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6223 && DECL_BIT_FIELD(TREE_OPERAND
6224 (TREE_OPERAND (varop, 0), 1)))
6227 = TREE_INT_CST_LOW (DECL_SIZE
6229 (TREE_OPERAND (varop, 0), 1)));
6230 tree mask, unsigned_type;
6231 unsigned int precision;
6232 tree folded_compare;
6234 if (constopnum == 0)
6235 folded_compare = fold (build (code, type, constop,
6236 TREE_OPERAND (varop, 0)));
6238 folded_compare = fold (build (code, type,
6239 TREE_OPERAND (varop, 0),
6241 if (integer_zerop (folded_compare)
6242 || integer_onep (folded_compare))
6243 return omit_one_operand (type, folded_compare, varop);
6245 unsigned_type = type_for_size (size, 1);
6246 precision = TYPE_PRECISION (unsigned_type);
6247 mask = build_int_2 (~0, ~0);
6248 TREE_TYPE (mask) = TREE_TYPE (varop);
6249 force_fit_type (mask, 0);
6250 mask = const_binop (RSHIFT_EXPR, mask,
6251 size_int (precision - size), 0);
6252 newconst = fold (build (BIT_AND_EXPR,
6253 TREE_TYPE (varop), newconst,
6254 convert (TREE_TYPE (varop),
6258 t = build (code, type,
6259 (constopnum == 0) ? newconst : varop,
6260 (constopnum == 1) ? newconst : varop);
6266 /* Change X >= CST to X > (CST - 1) if CST is positive. */
6267 if (TREE_CODE (arg1) == INTEGER_CST
6268 && TREE_CODE (arg0) != INTEGER_CST
6269 && tree_int_cst_sgn (arg1) > 0)
6271 switch (TREE_CODE (t))
6275 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6276 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6281 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6282 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6290 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6291 a MINUS_EXPR of a constant, we can convert it into a comparison with
6292 a revised constant as long as no overflow occurs. */
6293 if ((code == EQ_EXPR || code == NE_EXPR)
6294 && TREE_CODE (arg1) == INTEGER_CST
6295 && (TREE_CODE (arg0) == PLUS_EXPR
6296 || TREE_CODE (arg0) == MINUS_EXPR)
6297 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6298 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6299 ? MINUS_EXPR : PLUS_EXPR,
6300 arg1, TREE_OPERAND (arg0, 1), 0))
6301 && ! TREE_CONSTANT_OVERFLOW (tem))
6302 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6304 /* Similarly for a NEGATE_EXPR. */
6305 else if ((code == EQ_EXPR || code == NE_EXPR)
6306 && TREE_CODE (arg0) == NEGATE_EXPR
6307 && TREE_CODE (arg1) == INTEGER_CST
6308 && 0 != (tem = negate_expr (arg1))
6309 && TREE_CODE (tem) == INTEGER_CST
6310 && ! TREE_CONSTANT_OVERFLOW (tem))
6311 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6313 /* If we have X - Y == 0, we can convert that to X == Y and similarly
6314 for !=. Don't do this for ordered comparisons due to overflow. */
6315 else if ((code == NE_EXPR || code == EQ_EXPR)
6316 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
6317 return fold (build (code, type,
6318 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
6320 /* If we are widening one operand of an integer comparison,
6321 see if the other operand is similarly being widened. Perhaps we
6322 can do the comparison in the narrower type. */
6323 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
6324 && TREE_CODE (arg0) == NOP_EXPR
6325 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
6326 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
6327 && (TREE_TYPE (t1) == TREE_TYPE (tem)
6328 || (TREE_CODE (t1) == INTEGER_CST
6329 && int_fits_type_p (t1, TREE_TYPE (tem)))))
6330 return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
6332 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
6333 constant, we can simplify it. */
6334 else if (TREE_CODE (arg1) == INTEGER_CST
6335 && (TREE_CODE (arg0) == MIN_EXPR
6336 || TREE_CODE (arg0) == MAX_EXPR)
6337 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6338 return optimize_minmax_comparison (t);
6340 /* If we are comparing an ABS_EXPR with a constant, we can
6341 convert all the cases into explicit comparisons, but they may
6342 well not be faster than doing the ABS and one comparison.
6343 But ABS (X) <= C is a range comparison, which becomes a subtraction
6344 and a comparison, and is probably faster. */
6345 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6346 && TREE_CODE (arg0) == ABS_EXPR
6347 && ! TREE_SIDE_EFFECTS (arg0)
6348 && (0 != (tem = negate_expr (arg1)))
6349 && TREE_CODE (tem) == INTEGER_CST
6350 && ! TREE_CONSTANT_OVERFLOW (tem))
6351 return fold (build (TRUTH_ANDIF_EXPR, type,
6352 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
6353 build (LE_EXPR, type,
6354 TREE_OPERAND (arg0, 0), arg1)));
6356 /* If this is an EQ or NE comparison with zero and ARG0 is
6357 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
6358 two operations, but the latter can be done in one less insn
6359 on machines that have only two-operand insns or on which a
6360 constant cannot be the first operand. */
6361 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
6362 && TREE_CODE (arg0) == BIT_AND_EXPR)
6364 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
6365 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
6367 fold (build (code, type,
6368 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6370 TREE_TYPE (TREE_OPERAND (arg0, 0)),
6371 TREE_OPERAND (arg0, 1),
6372 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
6373 convert (TREE_TYPE (arg0),
6376 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
6377 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
6379 fold (build (code, type,
6380 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6382 TREE_TYPE (TREE_OPERAND (arg0, 1)),
6383 TREE_OPERAND (arg0, 0),
6384 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
6385 convert (TREE_TYPE (arg0),
6390 /* If this is an NE or EQ comparison of zero against the result of a
6391 signed MOD operation whose second operand is a power of 2, make
6392 the MOD operation unsigned since it is simpler and equivalent. */
6393 if ((code == NE_EXPR || code == EQ_EXPR)
6394 && integer_zerop (arg1)
6395 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
6396 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
6397 || TREE_CODE (arg0) == CEIL_MOD_EXPR
6398 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
6399 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
6400 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6402 tree newtype = unsigned_type (TREE_TYPE (arg0));
6403 tree newmod = build (TREE_CODE (arg0), newtype,
6404 convert (newtype, TREE_OPERAND (arg0, 0)),
6405 convert (newtype, TREE_OPERAND (arg0, 1)));
6407 return build (code, type, newmod, convert (newtype, arg1));
6410 /* If this is an NE comparison of zero with an AND of one, remove the
6411 comparison since the AND will give the correct value. */
6412 if (code == NE_EXPR && integer_zerop (arg1)
6413 && TREE_CODE (arg0) == BIT_AND_EXPR
6414 && integer_onep (TREE_OPERAND (arg0, 1)))
6415 return convert (type, arg0);
6417 /* If we have (A & C) == C where C is a power of 2, convert this into
6418 (A & C) != 0. Similarly for NE_EXPR. */
6419 if ((code == EQ_EXPR || code == NE_EXPR)
6420 && TREE_CODE (arg0) == BIT_AND_EXPR
6421 && integer_pow2p (TREE_OPERAND (arg0, 1))
6422 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
6423 return build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
6424 arg0, integer_zero_node);
6426 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
6427 and similarly for >= into !=. */
6428 if ((code == LT_EXPR || code == GE_EXPR)
6429 && TREE_UNSIGNED (TREE_TYPE (arg0))
6430 && TREE_CODE (arg1) == LSHIFT_EXPR
6431 && integer_onep (TREE_OPERAND (arg1, 0)))
6432 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6433 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6434 TREE_OPERAND (arg1, 1)),
6435 convert (TREE_TYPE (arg0), integer_zero_node));
6437 else if ((code == LT_EXPR || code == GE_EXPR)
6438 && TREE_UNSIGNED (TREE_TYPE (arg0))
6439 && (TREE_CODE (arg1) == NOP_EXPR
6440 || TREE_CODE (arg1) == CONVERT_EXPR)
6441 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
6442 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
6444 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6445 convert (TREE_TYPE (arg0),
6446 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6447 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
6448 convert (TREE_TYPE (arg0), integer_zero_node));
6450 /* Simplify comparison of something with itself. (For IEEE
6451 floating-point, we can only do some of these simplifications.) */
6452 if (operand_equal_p (arg0, arg1, 0))
6459 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
6460 return constant_boolean_node (1, type);
6462 TREE_SET_CODE (t, code);
6466 /* For NE, we can only do this simplification if integer. */
6467 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
6469 /* ... fall through ... */
6472 return constant_boolean_node (0, type);
6478 /* An unsigned comparison against 0 can be simplified. */
6479 if (integer_zerop (arg1)
6480 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6481 || POINTER_TYPE_P (TREE_TYPE (arg1)))
6482 && TREE_UNSIGNED (TREE_TYPE (arg1)))
6484 switch (TREE_CODE (t))
6488 TREE_SET_CODE (t, NE_EXPR);
6492 TREE_SET_CODE (t, EQ_EXPR);
6495 return omit_one_operand (type,
6496 convert (type, integer_one_node),
6499 return omit_one_operand (type,
6500 convert (type, integer_zero_node),
6507 /* Comparisons with the highest or lowest possible integer of
6508 the specified size will have known values and an unsigned
6509 <= 0x7fffffff can be simplified. */
6511 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
6513 if (TREE_CODE (arg1) == INTEGER_CST
6514 && ! TREE_CONSTANT_OVERFLOW (arg1)
6515 && width <= HOST_BITS_PER_WIDE_INT
6516 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6517 || POINTER_TYPE_P (TREE_TYPE (arg1))))
6519 if (TREE_INT_CST_HIGH (arg1) == 0
6520 && (TREE_INT_CST_LOW (arg1)
6521 == ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1)
6522 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6523 switch (TREE_CODE (t))
6526 return omit_one_operand (type,
6527 convert (type, integer_zero_node),
6530 TREE_SET_CODE (t, EQ_EXPR);
6534 return omit_one_operand (type,
6535 convert (type, integer_one_node),
6538 TREE_SET_CODE (t, NE_EXPR);
6545 else if (TREE_INT_CST_HIGH (arg1) == -1
6546 && (- TREE_INT_CST_LOW (arg1)
6547 == ((unsigned HOST_WIDE_INT) 1 << (width - 1)))
6548 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6549 switch (TREE_CODE (t))
6552 return omit_one_operand (type,
6553 convert (type, integer_zero_node),
6556 TREE_SET_CODE (t, EQ_EXPR);
6560 return omit_one_operand (type,
6561 convert (type, integer_one_node),
6564 TREE_SET_CODE (t, NE_EXPR);
6571 else if (TREE_INT_CST_HIGH (arg1) == 0
6572 && (TREE_INT_CST_LOW (arg1)
6573 == ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1)
6574 && TREE_UNSIGNED (TREE_TYPE (arg1)))
6576 switch (TREE_CODE (t))
6579 return fold (build (GE_EXPR, type,
6580 convert (signed_type (TREE_TYPE (arg0)),
6582 convert (signed_type (TREE_TYPE (arg1)),
6583 integer_zero_node)));
6585 return fold (build (LT_EXPR, type,
6586 convert (signed_type (TREE_TYPE (arg0)),
6588 convert (signed_type (TREE_TYPE (arg1)),
6589 integer_zero_node)));
6597 /* If we are comparing an expression that just has comparisons
6598 of two integer values, arithmetic expressions of those comparisons,
6599 and constants, we can simplify it. There are only three cases
6600 to check: the two values can either be equal, the first can be
6601 greater, or the second can be greater. Fold the expression for
6602 those three values. Since each value must be 0 or 1, we have
6603 eight possibilities, each of which corresponds to the constant 0
6604 or 1 or one of the six possible comparisons.
6606 This handles common cases like (a > b) == 0 but also handles
6607 expressions like ((x > y) - (y > x)) > 0, which supposedly
6608 occur in macroized code. */
6610 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
6612 tree cval1 = 0, cval2 = 0;
6615 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
6616 /* Don't handle degenerate cases here; they should already
6617 have been handled anyway. */
6618 && cval1 != 0 && cval2 != 0
6619 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
6620 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
6621 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
6622 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
6623 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
6624 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
6625 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
6627 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
6628 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
6630 /* We can't just pass T to eval_subst in case cval1 or cval2
6631 was the same as ARG1. */
6634 = fold (build (code, type,
6635 eval_subst (arg0, cval1, maxval, cval2, minval),
6638 = fold (build (code, type,
6639 eval_subst (arg0, cval1, maxval, cval2, maxval),
6642 = fold (build (code, type,
6643 eval_subst (arg0, cval1, minval, cval2, maxval),
6646 /* All three of these results should be 0 or 1. Confirm they
6647 are. Then use those values to select the proper code
6650 if ((integer_zerop (high_result)
6651 || integer_onep (high_result))
6652 && (integer_zerop (equal_result)
6653 || integer_onep (equal_result))
6654 && (integer_zerop (low_result)
6655 || integer_onep (low_result)))
6657 /* Make a 3-bit mask with the high-order bit being the
6658 value for `>', the next for '=', and the low for '<'. */
6659 switch ((integer_onep (high_result) * 4)
6660 + (integer_onep (equal_result) * 2)
6661 + integer_onep (low_result))
6665 return omit_one_operand (type, integer_zero_node, arg0);
6686 return omit_one_operand (type, integer_one_node, arg0);
6689 t = build (code, type, cval1, cval2);
6691 return save_expr (t);
6698 /* If this is a comparison of a field, we may be able to simplify it. */
6699 if ((TREE_CODE (arg0) == COMPONENT_REF
6700 || TREE_CODE (arg0) == BIT_FIELD_REF)
6701 && (code == EQ_EXPR || code == NE_EXPR)
6702 /* Handle the constant case even without -O
6703 to make sure the warnings are given. */
6704 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
6706 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
6710 /* If this is a comparison of complex values and either or both sides
6711 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6712 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6713 This may prevent needless evaluations. */
6714 if ((code == EQ_EXPR || code == NE_EXPR)
6715 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
6716 && (TREE_CODE (arg0) == COMPLEX_EXPR
6717 || TREE_CODE (arg1) == COMPLEX_EXPR
6718 || TREE_CODE (arg0) == COMPLEX_CST
6719 || TREE_CODE (arg1) == COMPLEX_CST))
6721 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
6722 tree real0, imag0, real1, imag1;
6724 arg0 = save_expr (arg0);
6725 arg1 = save_expr (arg1);
6726 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
6727 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
6728 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
6729 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
6731 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
6734 fold (build (code, type, real0, real1)),
6735 fold (build (code, type, imag0, imag1))));
6738 /* From here on, the only cases we handle are when the result is
6739 known to be a constant.
6741 To compute GT, swap the arguments and do LT.
6742 To compute GE, do LT and invert the result.
6743 To compute LE, swap the arguments, do LT and invert the result.
6744 To compute NE, do EQ and invert the result.
6746 Therefore, the code below must handle only EQ and LT. */
6748 if (code == LE_EXPR || code == GT_EXPR)
6750 tem = arg0, arg0 = arg1, arg1 = tem;
6751 code = swap_tree_comparison (code);
6754 /* Note that it is safe to invert for real values here because we
6755 will check below in the one case that it matters. */
6759 if (code == NE_EXPR || code == GE_EXPR)
6762 code = invert_tree_comparison (code);
6765 /* Compute a result for LT or EQ if args permit;
6766 otherwise return T. */
6767 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
6769 if (code == EQ_EXPR)
6770 t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0);
6772 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
6773 ? INT_CST_LT_UNSIGNED (arg0, arg1)
6774 : INT_CST_LT (arg0, arg1)),
6778 #if 0 /* This is no longer useful, but breaks some real code. */
6779 /* Assume a nonexplicit constant cannot equal an explicit one,
6780 since such code would be undefined anyway.
6781 Exception: on sysvr4, using #pragma weak,
6782 a label can come out as 0. */
6783 else if (TREE_CODE (arg1) == INTEGER_CST
6784 && !integer_zerop (arg1)
6785 && TREE_CONSTANT (arg0)
6786 && TREE_CODE (arg0) == ADDR_EXPR
6788 t1 = build_int_2 (0, 0);
6790 /* Two real constants can be compared explicitly. */
6791 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
6793 /* If either operand is a NaN, the result is false with two
6794 exceptions: First, an NE_EXPR is true on NaNs, but that case
6795 is already handled correctly since we will be inverting the
6796 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6797 or a GE_EXPR into a LT_EXPR, we must return true so that it
6798 will be inverted into false. */
6800 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
6801 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
6802 t1 = build_int_2 (invert && code == LT_EXPR, 0);
6804 else if (code == EQ_EXPR)
6805 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
6806 TREE_REAL_CST (arg1)),
6809 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
6810 TREE_REAL_CST (arg1)),
6814 if (t1 == NULL_TREE)
6818 TREE_INT_CST_LOW (t1) ^= 1;
6820 TREE_TYPE (t1) = type;
6821 if (TREE_CODE (type) == BOOLEAN_TYPE)
6822 return truthvalue_conversion (t1);
6826 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
6827 so all simple results must be passed through pedantic_non_lvalue. */
6828 if (TREE_CODE (arg0) == INTEGER_CST)
6829 return pedantic_non_lvalue
6830 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
6831 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
6832 return pedantic_omit_one_operand (type, arg1, arg0);
6834 /* If the second operand is zero, invert the comparison and swap
6835 the second and third operands. Likewise if the second operand
6836 is constant and the third is not or if the third operand is
6837 equivalent to the first operand of the comparison. */
6839 if (integer_zerop (arg1)
6840 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
6841 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6842 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6843 TREE_OPERAND (t, 2),
6844 TREE_OPERAND (arg0, 1))))
6846 /* See if this can be inverted. If it can't, possibly because
6847 it was a floating-point inequality comparison, don't do
6849 tem = invert_truthvalue (arg0);
6851 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6853 t = build (code, type, tem,
6854 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6856 /* arg1 should be the first argument of the new T. */
6857 arg1 = TREE_OPERAND (t, 1);
6862 /* If we have A op B ? A : C, we may be able to convert this to a
6863 simpler expression, depending on the operation and the values
6864 of B and C. IEEE floating point prevents this though,
6865 because A or B might be -0.0 or a NaN. */
6867 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6868 && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
6869 || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0)))
6871 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6872 arg1, TREE_OPERAND (arg0, 1)))
6874 tree arg2 = TREE_OPERAND (t, 2);
6875 enum tree_code comp_code = TREE_CODE (arg0);
6879 /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
6880 depending on the comparison operation. */
6881 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
6882 ? real_zerop (TREE_OPERAND (arg0, 1))
6883 : integer_zerop (TREE_OPERAND (arg0, 1)))
6884 && TREE_CODE (arg2) == NEGATE_EXPR
6885 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
6890 pedantic_non_lvalue (convert (type, negate_expr (arg1)));
6892 return pedantic_non_lvalue (convert (type, arg1));
6895 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6896 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6897 return pedantic_non_lvalue
6898 (convert (type, fold (build1 (ABS_EXPR,
6899 TREE_TYPE (arg1), arg1))));
6902 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6903 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6904 return pedantic_non_lvalue
6905 (negate_expr (convert (type,
6906 fold (build1 (ABS_EXPR,
6913 /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
6916 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
6918 if (comp_code == NE_EXPR)
6919 return pedantic_non_lvalue (convert (type, arg1));
6920 else if (comp_code == EQ_EXPR)
6921 return pedantic_non_lvalue (convert (type, integer_zero_node));
6924 /* If this is A op B ? A : B, this is either A, B, min (A, B),
6925 or max (A, B), depending on the operation. */
6927 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
6928 arg2, TREE_OPERAND (arg0, 0)))
6930 tree comp_op0 = TREE_OPERAND (arg0, 0);
6931 tree comp_op1 = TREE_OPERAND (arg0, 1);
6932 tree comp_type = TREE_TYPE (comp_op0);
6934 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
6935 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
6941 return pedantic_non_lvalue (convert (type, arg2));
6943 return pedantic_non_lvalue (convert (type, arg1));
6946 /* In C++ a ?: expression can be an lvalue, so put the
6947 operand which will be used if they are equal first
6948 so that we can convert this back to the
6949 corresponding COND_EXPR. */
6950 return pedantic_non_lvalue
6951 (convert (type, fold (build (MIN_EXPR, comp_type,
6952 (comp_code == LE_EXPR
6953 ? comp_op0 : comp_op1),
6954 (comp_code == LE_EXPR
6955 ? comp_op1 : comp_op0)))));
6959 return pedantic_non_lvalue
6960 (convert (type, fold (build (MAX_EXPR, comp_type,
6961 (comp_code == GE_EXPR
6962 ? comp_op0 : comp_op1),
6963 (comp_code == GE_EXPR
6964 ? comp_op1 : comp_op0)))));
6971 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
6972 we might still be able to simplify this. For example,
6973 if C1 is one less or one more than C2, this might have started
6974 out as a MIN or MAX and been transformed by this function.
6975 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
6977 if (INTEGRAL_TYPE_P (type)
6978 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6979 && TREE_CODE (arg2) == INTEGER_CST)
6983 /* We can replace A with C1 in this case. */
6984 arg1 = convert (type, TREE_OPERAND (arg0, 1));
6985 t = build (code, type, TREE_OPERAND (t, 0), arg1,
6986 TREE_OPERAND (t, 2));
6990 /* If C1 is C2 + 1, this is min(A, C2). */
6991 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6992 && operand_equal_p (TREE_OPERAND (arg0, 1),
6993 const_binop (PLUS_EXPR, arg2,
6994 integer_one_node, 0), 1))
6995 return pedantic_non_lvalue
6996 (fold (build (MIN_EXPR, type, arg1, arg2)));
7000 /* If C1 is C2 - 1, this is min(A, C2). */
7001 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7002 && operand_equal_p (TREE_OPERAND (arg0, 1),
7003 const_binop (MINUS_EXPR, arg2,
7004 integer_one_node, 0), 1))
7005 return pedantic_non_lvalue
7006 (fold (build (MIN_EXPR, type, arg1, arg2)));
7010 /* If C1 is C2 - 1, this is max(A, C2). */
7011 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7012 && operand_equal_p (TREE_OPERAND (arg0, 1),
7013 const_binop (MINUS_EXPR, arg2,
7014 integer_one_node, 0), 1))
7015 return pedantic_non_lvalue
7016 (fold (build (MAX_EXPR, type, arg1, arg2)));
7020 /* If C1 is C2 + 1, this is max(A, C2). */
7021 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7022 && operand_equal_p (TREE_OPERAND (arg0, 1),
7023 const_binop (PLUS_EXPR, arg2,
7024 integer_one_node, 0), 1))
7025 return pedantic_non_lvalue
7026 (fold (build (MAX_EXPR, type, arg1, arg2)));
7035 /* If the second operand is simpler than the third, swap them
7036 since that produces better jump optimization results. */
7037 if ((TREE_CONSTANT (arg1) || DECL_P (arg1)
7038 || TREE_CODE (arg1) == SAVE_EXPR)
7039 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
7040 || DECL_P (TREE_OPERAND (t, 2))
7041 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
7043 /* See if this can be inverted. If it can't, possibly because
7044 it was a floating-point inequality comparison, don't do
7046 tem = invert_truthvalue (arg0);
7048 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7050 t = build (code, type, tem,
7051 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7053 /* arg1 should be the first argument of the new T. */
7054 arg1 = TREE_OPERAND (t, 1);
7059 /* Convert A ? 1 : 0 to simply A. */
7060 if (integer_onep (TREE_OPERAND (t, 1))
7061 && integer_zerop (TREE_OPERAND (t, 2))
7062 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7063 call to fold will try to move the conversion inside
7064 a COND, which will recurse. In that case, the COND_EXPR
7065 is probably the best choice, so leave it alone. */
7066 && type == TREE_TYPE (arg0))
7067 return pedantic_non_lvalue (arg0);
7069 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7070 operation is simply A & 2. */
7072 if (integer_zerop (TREE_OPERAND (t, 2))
7073 && TREE_CODE (arg0) == NE_EXPR
7074 && integer_zerop (TREE_OPERAND (arg0, 1))
7075 && integer_pow2p (arg1)
7076 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
7077 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
7079 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
7084 /* When pedantic, a compound expression can be neither an lvalue
7085 nor an integer constant expression. */
7086 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
7088 /* Don't let (0, 0) be null pointer constant. */
7089 if (integer_zerop (arg1))
7090 return build1 (NOP_EXPR, type, arg1);
7091 return convert (type, arg1);
7095 return build_complex (type, arg0, arg1);
7099 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7101 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7102 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7103 TREE_OPERAND (arg0, 1));
7104 else if (TREE_CODE (arg0) == COMPLEX_CST)
7105 return TREE_REALPART (arg0);
7106 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7107 return fold (build (TREE_CODE (arg0), type,
7108 fold (build1 (REALPART_EXPR, type,
7109 TREE_OPERAND (arg0, 0))),
7110 fold (build1 (REALPART_EXPR,
7111 type, TREE_OPERAND (arg0, 1)))));
7115 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7116 return convert (type, integer_zero_node);
7117 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7118 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7119 TREE_OPERAND (arg0, 0));
7120 else if (TREE_CODE (arg0) == COMPLEX_CST)
7121 return TREE_IMAGPART (arg0);
7122 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7123 return fold (build (TREE_CODE (arg0), type,
7124 fold (build1 (IMAGPART_EXPR, type,
7125 TREE_OPERAND (arg0, 0))),
7126 fold (build1 (IMAGPART_EXPR, type,
7127 TREE_OPERAND (arg0, 1)))));
7130 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7132 case CLEANUP_POINT_EXPR:
7133 if (! has_cleanups (arg0))
7134 return TREE_OPERAND (t, 0);
7137 enum tree_code code0 = TREE_CODE (arg0);
7138 int kind0 = TREE_CODE_CLASS (code0);
7139 tree arg00 = TREE_OPERAND (arg0, 0);
7142 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
7143 return fold (build1 (code0, type,
7144 fold (build1 (CLEANUP_POINT_EXPR,
7145 TREE_TYPE (arg00), arg00))));
7147 if (kind0 == '<' || kind0 == '2'
7148 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
7149 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
7150 || code0 == TRUTH_XOR_EXPR)
7152 arg01 = TREE_OPERAND (arg0, 1);
7154 if (TREE_CONSTANT (arg00)
7155 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
7156 && ! has_cleanups (arg00)))
7157 return fold (build (code0, type, arg00,
7158 fold (build1 (CLEANUP_POINT_EXPR,
7159 TREE_TYPE (arg01), arg01))));
7161 if (TREE_CONSTANT (arg01))
7162 return fold (build (code0, type,
7163 fold (build1 (CLEANUP_POINT_EXPR,
7164 TREE_TYPE (arg00), arg00)),
7173 } /* switch (code) */
7176 /* Determine if first argument is a multiple of second argument. Return 0 if
7177 it is not, or we cannot easily determined it to be.
7179 An example of the sort of thing we care about (at this point; this routine
7180 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7181 fold cases do now) is discovering that
7183 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7189 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7191 This code also handles discovering that
7193 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7195 is a multiple of 8 so we don't have to worry about dealing with a
7198 Note that we *look* inside a SAVE_EXPR only to determine how it was
7199 calculated; it is not safe for fold to do much of anything else with the
7200 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7201 at run time. For example, the latter example above *cannot* be implemented
7202 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7203 evaluation time of the original SAVE_EXPR is not necessarily the same at
7204 the time the new expression is evaluated. The only optimization of this
7205 sort that would be valid is changing
7207 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7211 SAVE_EXPR (I) * SAVE_EXPR (J)
7213 (where the same SAVE_EXPR (J) is used in the original and the
7214 transformed version). */
7217 multiple_of_p (type, top, bottom)
7222 if (operand_equal_p (top, bottom, 0))
7225 if (TREE_CODE (type) != INTEGER_TYPE)
7228 switch (TREE_CODE (top))
7231 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7232 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7236 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7237 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7240 /* Can't handle conversions from non-integral or wider integral type. */
7241 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
7242 || (TYPE_PRECISION (type)
7243 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
7246 /* .. fall through ... */
7249 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
7252 if ((TREE_CODE (bottom) != INTEGER_CST)
7253 || (tree_int_cst_sgn (top) < 0)
7254 || (tree_int_cst_sgn (bottom) < 0))
7256 return integer_zerop (const_binop (TRUNC_MOD_EXPR,