1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 88, 92-98, 1999, 2000 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
21 /*@@ This file should be rewritten to use an arbitrary precision
22 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
23 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
24 @@ The routines that translate from the ap rep should
25 @@ warn if precision et. al. is lost.
26 @@ This would also make life easier when this technology is used
27 @@ 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 PROTO((HOST_WIDE_INT *,
56 HOST_WIDE_INT, HOST_WIDE_INT));
57 static void decode PROTO((HOST_WIDE_INT *,
58 HOST_WIDE_INT *, HOST_WIDE_INT *));
59 int div_and_round_double PROTO((enum tree_code, int, HOST_WIDE_INT,
60 HOST_WIDE_INT, HOST_WIDE_INT,
61 HOST_WIDE_INT, HOST_WIDE_INT *,
62 HOST_WIDE_INT *, HOST_WIDE_INT *,
64 static tree negate_expr PROTO((tree));
65 static tree split_tree PROTO((tree, enum tree_code, tree *, tree *,
67 static tree associate_trees PROTO((tree, tree, enum tree_code, tree));
68 static tree int_const_binop PROTO((enum tree_code, tree, tree, int, int));
69 static void const_binop_1 PROTO((PTR));
70 static tree const_binop PROTO((enum tree_code, tree, tree, int));
71 static void fold_convert_1 PROTO((PTR));
72 static tree fold_convert PROTO((tree, tree));
73 static enum tree_code invert_tree_comparison PROTO((enum tree_code));
74 static enum tree_code swap_tree_comparison PROTO((enum tree_code));
75 static int truth_value_p PROTO((enum tree_code));
76 static int operand_equal_for_comparison_p PROTO((tree, tree, tree));
77 static int twoval_comparison_p PROTO((tree, tree *, tree *, int *));
78 static tree eval_subst PROTO((tree, tree, tree, tree, tree));
79 static tree omit_one_operand PROTO((tree, tree, tree));
80 static tree pedantic_omit_one_operand PROTO((tree, tree, tree));
81 static tree distribute_bit_expr PROTO((enum tree_code, tree, tree, tree));
82 static tree make_bit_field_ref PROTO((tree, tree, int, int, int));
83 static tree optimize_bit_field_compare PROTO((enum tree_code, tree,
85 static tree decode_field_reference PROTO((tree, int *, int *,
86 enum machine_mode *, int *,
87 int *, tree *, tree *));
88 static int all_ones_mask_p PROTO((tree, int));
89 static int simple_operand_p PROTO((tree));
90 static tree range_binop PROTO((enum tree_code, tree, tree, int,
92 static tree make_range PROTO((tree, int *, tree *, tree *));
93 static tree build_range_check PROTO((tree, tree, int, tree, tree));
94 static int merge_ranges PROTO((int *, tree *, tree *, int, tree, tree,
96 static tree fold_range_test PROTO((tree));
97 static tree unextend PROTO((tree, int, int, tree));
98 static tree fold_truthop PROTO((enum tree_code, tree, tree, tree));
99 static tree optimize_minmax_comparison PROTO((tree));
100 static tree extract_muldiv PROTO((tree, tree, enum tree_code, tree));
101 static tree strip_compound_expr PROTO((tree, tree));
102 static int multiple_of_p PROTO((tree, tree, tree));
103 static tree constant_boolean_node PROTO((int, tree));
104 static int count_cond PROTO((tree, int));
107 #define BRANCH_COST 1
110 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
111 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
112 and SUM1. Then this yields nonzero if overflow occurred during the
115 Overflow occurs if A and B have the same sign, but A and SUM differ in
116 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
118 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
120 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
121 We do that by representing the two-word integer in 4 words, with only
122 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
123 number. The value of the word is LOWPART + HIGHPART * BASE. */
126 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
127 #define HIGHPART(x) \
128 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
129 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
131 /* Unpack a two-word integer into 4 words.
132 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
133 WORDS points to the array of HOST_WIDE_INTs. */
136 encode (words, low, hi)
137 HOST_WIDE_INT *words;
138 HOST_WIDE_INT low, hi;
140 words[0] = LOWPART (low);
141 words[1] = HIGHPART (low);
142 words[2] = LOWPART (hi);
143 words[3] = HIGHPART (hi);
146 /* Pack an array of 4 words into a two-word integer.
147 WORDS points to the array of words.
148 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
151 decode (words, low, hi)
152 HOST_WIDE_INT *words;
153 HOST_WIDE_INT *low, *hi;
155 *low = words[0] + words[1] * BASE;
156 *hi = words[2] + words[3] * BASE;
159 /* Make the integer constant T valid for its type by setting to 0 or 1 all
160 the bits in the constant that don't belong in the type.
162 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
163 nonzero, a signed overflow has already occurred in calculating T, so
166 Make the real constant T valid for its type by calling CHECK_FLOAT_VALUE,
170 force_fit_type (t, overflow)
174 HOST_WIDE_INT low, high;
177 if (TREE_CODE (t) == REAL_CST)
179 #ifdef CHECK_FLOAT_VALUE
180 CHECK_FLOAT_VALUE (TYPE_MODE (TREE_TYPE (t)), TREE_REAL_CST (t),
186 else if (TREE_CODE (t) != INTEGER_CST)
189 low = TREE_INT_CST_LOW (t);
190 high = TREE_INT_CST_HIGH (t);
192 if (POINTER_TYPE_P (TREE_TYPE (t)))
195 prec = TYPE_PRECISION (TREE_TYPE (t));
197 /* First clear all bits that are beyond the type's precision. */
199 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
201 else if (prec > HOST_BITS_PER_WIDE_INT)
202 TREE_INT_CST_HIGH (t)
203 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
206 TREE_INT_CST_HIGH (t) = 0;
207 if (prec < HOST_BITS_PER_WIDE_INT)
208 TREE_INT_CST_LOW (t) &= ~((HOST_WIDE_INT) (-1) << prec);
211 /* Unsigned types do not suffer sign extension or overflow. */
212 if (TREE_UNSIGNED (TREE_TYPE (t)))
215 /* If the value's sign bit is set, extend the sign. */
216 if (prec != 2 * HOST_BITS_PER_WIDE_INT
217 && (prec > HOST_BITS_PER_WIDE_INT
218 ? (TREE_INT_CST_HIGH (t)
219 & ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
220 : TREE_INT_CST_LOW (t) & ((HOST_WIDE_INT) 1 << (prec - 1))))
222 /* Value is negative:
223 set to 1 all the bits that are outside this type's precision. */
224 if (prec > HOST_BITS_PER_WIDE_INT)
225 TREE_INT_CST_HIGH (t)
226 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
229 TREE_INT_CST_HIGH (t) = -1;
230 if (prec < HOST_BITS_PER_WIDE_INT)
231 TREE_INT_CST_LOW (t) |= ((HOST_WIDE_INT) (-1) << prec);
235 /* Return nonzero if signed overflow occurred. */
237 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
241 /* Add two doubleword integers with doubleword result.
242 Each argument is given as two `HOST_WIDE_INT' pieces.
243 One argument is L1 and H1; the other, L2 and H2.
244 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
247 add_double (l1, h1, l2, h2, lv, hv)
248 HOST_WIDE_INT l1, h1, l2, h2;
249 HOST_WIDE_INT *lv, *hv;
254 h = h1 + h2 + ((unsigned HOST_WIDE_INT) l < l1);
258 return OVERFLOW_SUM_SIGN (h1, h2, h);
261 /* Negate a doubleword integer with doubleword result.
262 Return nonzero if the operation overflows, assuming it's signed.
263 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
264 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
267 neg_double (l1, h1, lv, hv)
268 HOST_WIDE_INT l1, h1;
269 HOST_WIDE_INT *lv, *hv;
275 return (*hv & h1) < 0;
285 /* Multiply two doubleword integers with doubleword result.
286 Return nonzero if the operation overflows, assuming it's signed.
287 Each argument is given as two `HOST_WIDE_INT' pieces.
288 One argument is L1 and H1; the other, L2 and H2.
289 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
292 mul_double (l1, h1, l2, h2, lv, hv)
293 HOST_WIDE_INT l1, h1, l2, h2;
294 HOST_WIDE_INT *lv, *hv;
296 HOST_WIDE_INT arg1[4];
297 HOST_WIDE_INT arg2[4];
298 HOST_WIDE_INT prod[4 * 2];
299 register unsigned HOST_WIDE_INT carry;
300 register int i, j, k;
301 HOST_WIDE_INT toplow, tophigh, neglow, neghigh;
303 encode (arg1, l1, h1);
304 encode (arg2, l2, h2);
306 bzero ((char *) prod, sizeof prod);
308 for (i = 0; i < 4; i++)
311 for (j = 0; j < 4; j++)
314 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
315 carry += arg1[i] * arg2[j];
316 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
318 prod[k] = LOWPART (carry);
319 carry = HIGHPART (carry);
324 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
326 /* Check for overflow by calculating the top half of the answer in full;
327 it should agree with the low half's sign bit. */
328 decode (prod+4, &toplow, &tophigh);
331 neg_double (l2, h2, &neglow, &neghigh);
332 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
336 neg_double (l1, h1, &neglow, &neghigh);
337 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
339 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
342 /* Shift the doubleword integer in L1, H1 left by COUNT places
343 keeping only PREC bits of result.
344 Shift right if COUNT is negative.
345 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
346 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
349 lshift_double (l1, h1, count, prec, lv, hv, arith)
350 HOST_WIDE_INT l1, h1, count;
352 HOST_WIDE_INT *lv, *hv;
357 rshift_double (l1, h1, - count, prec, lv, hv, arith);
361 #ifdef SHIFT_COUNT_TRUNCATED
362 if (SHIFT_COUNT_TRUNCATED)
366 if (count >= HOST_BITS_PER_WIDE_INT)
368 *hv = (unsigned HOST_WIDE_INT) l1 << (count - HOST_BITS_PER_WIDE_INT);
373 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
374 | ((unsigned HOST_WIDE_INT) l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
375 *lv = (unsigned HOST_WIDE_INT) l1 << count;
379 /* Shift the doubleword integer in L1, H1 right by COUNT places
380 keeping only PREC bits of result. COUNT must be positive.
381 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
382 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
385 rshift_double (l1, h1, count, prec, lv, hv, arith)
386 HOST_WIDE_INT l1, h1, count;
387 int prec ATTRIBUTE_UNUSED;
388 HOST_WIDE_INT *lv, *hv;
391 unsigned HOST_WIDE_INT signmask;
393 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
396 #ifdef SHIFT_COUNT_TRUNCATED
397 if (SHIFT_COUNT_TRUNCATED)
401 if (count >= HOST_BITS_PER_WIDE_INT)
404 *lv = ((signmask << (2 * HOST_BITS_PER_WIDE_INT - count - 1) << 1)
405 | ((unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT)));
409 *lv = (((unsigned HOST_WIDE_INT) l1 >> count)
410 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
411 *hv = ((signmask << (HOST_BITS_PER_WIDE_INT - count))
412 | ((unsigned HOST_WIDE_INT) h1 >> count));
416 /* Rotate the doubleword integer in L1, H1 left by COUNT places
417 keeping only PREC bits of result.
418 Rotate right if COUNT is negative.
419 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
422 lrotate_double (l1, h1, count, prec, lv, hv)
423 HOST_WIDE_INT l1, h1, count;
425 HOST_WIDE_INT *lv, *hv;
427 HOST_WIDE_INT s1l, s1h, s2l, s2h;
433 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
434 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
439 /* Rotate the doubleword integer in L1, H1 left by COUNT places
440 keeping only PREC bits of result. COUNT must be positive.
441 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
444 rrotate_double (l1, h1, count, prec, lv, hv)
445 HOST_WIDE_INT l1, h1, count;
447 HOST_WIDE_INT *lv, *hv;
449 HOST_WIDE_INT s1l, s1h, s2l, s2h;
455 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
456 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
461 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
462 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
463 CODE is a tree code for a kind of division, one of
464 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
466 It controls how the quotient is rounded to a integer.
467 Return nonzero if the operation overflows.
468 UNS nonzero says do unsigned division. */
471 div_and_round_double (code, uns,
472 lnum_orig, hnum_orig, lden_orig, hden_orig,
473 lquo, hquo, lrem, hrem)
476 HOST_WIDE_INT lnum_orig, hnum_orig; /* num == numerator == dividend */
477 HOST_WIDE_INT lden_orig, hden_orig; /* den == denominator == divisor */
478 HOST_WIDE_INT *lquo, *hquo, *lrem, *hrem;
481 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
482 HOST_WIDE_INT den[4], quo[4];
484 unsigned HOST_WIDE_INT work;
485 register unsigned HOST_WIDE_INT carry = 0;
486 HOST_WIDE_INT lnum = lnum_orig;
487 HOST_WIDE_INT hnum = hnum_orig;
488 HOST_WIDE_INT lden = lden_orig;
489 HOST_WIDE_INT hden = hden_orig;
492 if ((hden == 0) && (lden == 0))
493 overflow = 1, lden = 1;
495 /* calculate quotient sign and convert operands to unsigned. */
501 /* (minimum integer) / (-1) is the only overflow case. */
502 if (neg_double (lnum, hnum, &lnum, &hnum) && (lden & hden) == -1)
508 neg_double (lden, hden, &lden, &hden);
512 if (hnum == 0 && hden == 0)
513 { /* single precision */
515 /* This unsigned division rounds toward zero. */
516 *lquo = lnum / (unsigned HOST_WIDE_INT) lden;
521 { /* trivial case: dividend < divisor */
522 /* hden != 0 already checked. */
529 bzero ((char *) quo, sizeof quo);
531 bzero ((char *) num, sizeof num); /* to zero 9th element */
532 bzero ((char *) den, sizeof den);
534 encode (num, lnum, hnum);
535 encode (den, lden, hden);
537 /* Special code for when the divisor < BASE. */
538 if (hden == 0 && lden < (HOST_WIDE_INT) BASE)
540 /* hnum != 0 already checked. */
541 for (i = 4 - 1; i >= 0; i--)
543 work = num[i] + carry * BASE;
544 quo[i] = work / (unsigned HOST_WIDE_INT) lden;
545 carry = work % (unsigned HOST_WIDE_INT) lden;
550 /* Full double precision division,
551 with thanks to Don Knuth's "Seminumerical Algorithms". */
552 int num_hi_sig, den_hi_sig;
553 unsigned HOST_WIDE_INT quo_est, scale;
555 /* Find the highest non-zero divisor digit. */
556 for (i = 4 - 1; ; i--)
562 /* Insure that the first digit of the divisor is at least BASE/2.
563 This is required by the quotient digit estimation algorithm. */
565 scale = BASE / (den[den_hi_sig] + 1);
566 if (scale > 1) { /* scale divisor and dividend */
568 for (i = 0; i <= 4 - 1; i++) {
569 work = (num[i] * scale) + carry;
570 num[i] = LOWPART (work);
571 carry = HIGHPART (work);
574 for (i = 0; i <= 4 - 1; i++) {
575 work = (den[i] * scale) + carry;
576 den[i] = LOWPART (work);
577 carry = HIGHPART (work);
578 if (den[i] != 0) den_hi_sig = i;
585 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--) {
586 /* guess the next quotient digit, quo_est, by dividing the first
587 two remaining dividend digits by the high order quotient digit.
588 quo_est is never low and is at most 2 high. */
589 unsigned HOST_WIDE_INT tmp;
591 num_hi_sig = i + den_hi_sig + 1;
592 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
593 if (num[num_hi_sig] != den[den_hi_sig])
594 quo_est = work / den[den_hi_sig];
598 /* refine quo_est so it's usually correct, and at most one high. */
599 tmp = work - quo_est * den[den_hi_sig];
601 && den[den_hi_sig - 1] * quo_est > (tmp * BASE + num[num_hi_sig - 2]))
604 /* Try QUO_EST as the quotient digit, by multiplying the
605 divisor by QUO_EST and subtracting from the remaining dividend.
606 Keep in mind that QUO_EST is the I - 1st digit. */
609 for (j = 0; j <= den_hi_sig; j++)
611 work = quo_est * den[j] + carry;
612 carry = HIGHPART (work);
613 work = num[i + j] - LOWPART (work);
614 num[i + j] = LOWPART (work);
615 carry += HIGHPART (work) != 0;
618 /* if quo_est was high by one, then num[i] went negative and
619 we need to correct things. */
621 if (num[num_hi_sig] < carry)
624 carry = 0; /* add divisor back in */
625 for (j = 0; j <= den_hi_sig; j++)
627 work = num[i + j] + den[j] + carry;
628 carry = HIGHPART (work);
629 num[i + j] = LOWPART (work);
631 num [num_hi_sig] += carry;
634 /* store the quotient digit. */
639 decode (quo, lquo, hquo);
642 /* if result is negative, make it so. */
644 neg_double (*lquo, *hquo, lquo, hquo);
646 /* compute trial remainder: rem = num - (quo * den) */
647 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
648 neg_double (*lrem, *hrem, lrem, hrem);
649 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
654 case TRUNC_MOD_EXPR: /* round toward zero */
655 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
659 case FLOOR_MOD_EXPR: /* round toward negative infinity */
660 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
663 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
666 else return overflow;
670 case CEIL_MOD_EXPR: /* round toward positive infinity */
671 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
673 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
676 else return overflow;
680 case ROUND_MOD_EXPR: /* round to closest integer */
682 HOST_WIDE_INT labs_rem = *lrem, habs_rem = *hrem;
683 HOST_WIDE_INT labs_den = lden, habs_den = hden, ltwice, htwice;
685 /* get absolute values */
686 if (*hrem < 0) neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
687 if (hden < 0) neg_double (lden, hden, &labs_den, &habs_den);
689 /* if (2 * abs (lrem) >= abs (lden)) */
690 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
691 labs_rem, habs_rem, <wice, &htwice);
692 if (((unsigned HOST_WIDE_INT) habs_den
693 < (unsigned HOST_WIDE_INT) htwice)
694 || (((unsigned HOST_WIDE_INT) habs_den
695 == (unsigned HOST_WIDE_INT) htwice)
696 && ((HOST_WIDE_INT unsigned) labs_den
697 < (unsigned HOST_WIDE_INT) ltwice)))
701 add_double (*lquo, *hquo,
702 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
705 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
708 else return overflow;
716 /* compute true remainder: rem = num - (quo * den) */
717 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
718 neg_double (*lrem, *hrem, lrem, hrem);
719 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
723 #ifndef REAL_ARITHMETIC
724 /* Effectively truncate a real value to represent the nearest possible value
725 in a narrower mode. The result is actually represented in the same data
726 type as the argument, but its value is usually different.
728 A trap may occur during the FP operations and it is the responsibility
729 of the calling function to have a handler established. */
732 real_value_truncate (mode, arg)
733 enum machine_mode mode;
736 return REAL_VALUE_TRUNCATE (mode, arg);
739 #if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
741 /* Check for infinity in an IEEE double precision number. */
747 /* The IEEE 64-bit double format. */
752 unsigned exponent : 11;
753 unsigned mantissa1 : 20;
758 unsigned mantissa1 : 20;
759 unsigned exponent : 11;
765 if (u.big_endian.sign == 1)
768 return (u.big_endian.exponent == 2047
769 && u.big_endian.mantissa1 == 0
770 && u.big_endian.mantissa2 == 0);
775 return (u.little_endian.exponent == 2047
776 && u.little_endian.mantissa1 == 0
777 && u.little_endian.mantissa2 == 0);
781 /* Check whether an IEEE double precision number is a NaN. */
787 /* The IEEE 64-bit double format. */
792 unsigned exponent : 11;
793 unsigned mantissa1 : 20;
798 unsigned mantissa1 : 20;
799 unsigned exponent : 11;
805 if (u.big_endian.sign == 1)
808 return (u.big_endian.exponent == 2047
809 && (u.big_endian.mantissa1 != 0
810 || u.big_endian.mantissa2 != 0));
815 return (u.little_endian.exponent == 2047
816 && (u.little_endian.mantissa1 != 0
817 || u.little_endian.mantissa2 != 0));
821 /* Check for a negative IEEE double precision number. */
827 /* The IEEE 64-bit double format. */
832 unsigned exponent : 11;
833 unsigned mantissa1 : 20;
838 unsigned mantissa1 : 20;
839 unsigned exponent : 11;
845 if (u.big_endian.sign == 1)
848 return u.big_endian.sign;
853 return u.little_endian.sign;
856 #else /* Target not IEEE */
858 /* Let's assume other float formats don't have infinity.
859 (This can be overridden by redefining REAL_VALUE_ISINF.) */
868 /* Let's assume other float formats don't have NaNs.
869 (This can be overridden by redefining REAL_VALUE_ISNAN.) */
878 /* Let's assume other float formats don't have minus zero.
879 (This can be overridden by redefining REAL_VALUE_NEGATIVE.) */
887 #endif /* Target not IEEE */
889 /* Try to change R into its exact multiplicative inverse in machine mode
890 MODE. Return nonzero function value if successful. */
893 exact_real_inverse (mode, r)
894 enum machine_mode mode;
905 /* Usually disable if bounds checks are not reliable. */
906 if ((HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT) && !flag_pretend_float)
909 /* Set array index to the less significant bits in the unions, depending
910 on the endian-ness of the host doubles.
911 Disable if insufficient information on the data structure. */
912 #if HOST_FLOAT_FORMAT == UNKNOWN_FLOAT_FORMAT
915 #if HOST_FLOAT_FORMAT == VAX_FLOAT_FORMAT
918 #if HOST_FLOAT_FORMAT == IBM_FLOAT_FORMAT
921 #define K (2 * HOST_FLOAT_WORDS_BIG_ENDIAN)
926 if (setjmp (float_error))
928 /* Don't do the optimization if there was an arithmetic error. */
930 set_float_handler (NULL_PTR);
933 set_float_handler (float_error);
935 /* Domain check the argument. */
941 if (REAL_VALUE_ISINF (x.d) || REAL_VALUE_ISNAN (x.d))
945 /* Compute the reciprocal and check for numerical exactness.
946 It is unnecessary to check all the significand bits to determine
947 whether X is a power of 2. If X is not, then it is impossible for
948 the bottom half significand of both X and 1/X to be all zero bits.
949 Hence we ignore the data structure of the top half and examine only
950 the low order bits of the two significands. */
952 if (x.i[K] != 0 || x.i[K + 1] != 0 || t.i[K] != 0 || t.i[K + 1] != 0)
955 /* Truncate to the required mode and range-check the result. */
956 y.d = REAL_VALUE_TRUNCATE (mode, t.d);
957 #ifdef CHECK_FLOAT_VALUE
959 if (CHECK_FLOAT_VALUE (mode, y.d, i))
963 /* Fail if truncation changed the value. */
964 if (y.d != t.d || y.d == 0.0)
968 if (REAL_VALUE_ISINF (y.d) || REAL_VALUE_ISNAN (y.d))
972 /* Output the reciprocal and return success flag. */
973 set_float_handler (NULL_PTR);
978 /* Convert C9X hexadecimal floating point string constant S. Return
979 real value type in mode MODE. This function uses the host computer's
980 floating point arithmetic when there is no REAL_ARITHMETIC. */
983 real_hex_to_f (s, mode)
985 enum machine_mode mode;
989 unsigned HOST_WIDE_INT low, high;
990 int shcount, nrmcount, k;
991 int sign, expsign, isfloat;
992 int lost = 0;/* Nonzero low order bits shifted out and discarded. */
993 int frexpon = 0; /* Bits after the decimal point. */
994 int expon = 0; /* Value of exponent. */
995 int decpt = 0; /* How many decimal points. */
996 int gotp = 0; /* How many P's. */
1003 while (*p == ' ' || *p == '\t')
1006 /* Sign, if any, comes first. */
1014 /* The string is supposed to start with 0x or 0X . */
1018 if (*p == 'x' || *p == 'X')
1032 while ((c = *p) != '\0')
1034 if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F')
1035 || (c >= 'a' && c <= 'f'))
1045 if ((high & 0xf0000000) == 0)
1047 high = (high << 4) + ((low >> 28) & 15);
1048 low = (low << 4) + k;
1055 /* Record nonzero lost bits. */
1068 else if (c == 'p' || c == 'P')
1072 /* Sign of exponent. */
1079 /* Value of exponent.
1080 The exponent field is a decimal integer. */
1083 k = (*p++ & 0x7f) - '0';
1084 expon = 10 * expon + k;
1088 /* F suffix is ambiguous in the significand part
1089 so it must appear after the decimal exponent field. */
1090 if (*p == 'f' || *p == 'F')
1098 else if (c == 'l' || c == 'L')
1107 /* Abort if last character read was not legitimate. */
1109 if ((c != '\0' && c != ' ' && c != '\n' && c != '\r') || (decpt > 1))
1112 /* There must be either one decimal point or one p. */
1113 if (decpt == 0 && gotp == 0)
1117 if (high == 0 && low == 0)
1129 /* Leave a high guard bit for carry-out. */
1130 if ((high & 0x80000000) != 0)
1133 low = (low >> 1) | (high << 31);
1138 if ((high & 0xffff8000) == 0)
1140 high = (high << 16) + ((low >> 16) & 0xffff);
1145 while ((high & 0xc0000000) == 0)
1147 high = (high << 1) + ((low >> 31) & 1);
1152 if (isfloat || GET_MODE_SIZE(mode) == UNITS_PER_WORD)
1154 /* Keep 24 bits precision, bits 0x7fffff80.
1155 Rounding bit is 0x40. */
1156 lost = lost | low | (high & 0x3f);
1160 if ((high & 0x80) || lost)
1167 /* We need real.c to do long double formats, so here default
1168 to double precision. */
1169 #if HOST_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
1171 Keep 53 bits precision, bits 0x7fffffff fffffc00.
1172 Rounding bit is low word 0x200. */
1173 lost = lost | (low & 0x1ff);
1176 if ((low & 0x400) || lost)
1178 low = (low + 0x200) & 0xfffffc00;
1185 /* Assume it's a VAX with 56-bit significand,
1186 bits 0x7fffffff ffffff80. */
1187 lost = lost | (low & 0x7f);
1190 if ((low & 0x80) || lost)
1192 low = (low + 0x40) & 0xffffff80;
1202 ip = REAL_VALUE_LDEXP (ip, 32) + (double) low;
1203 /* Apply shifts and exponent value as power of 2. */
1204 ip = REAL_VALUE_LDEXP (ip, expon - (nrmcount + frexpon));
1211 #endif /* no REAL_ARITHMETIC */
1213 /* Given T, an expression, return the negation of T. Allow for T to be
1214 null, in which case return null. */
1226 type = TREE_TYPE (t);
1227 STRIP_SIGN_NOPS (t);
1229 switch (TREE_CODE (t))
1233 if (! TREE_UNSIGNED (type)
1234 && 0 != (tem = fold (build1 (NEGATE_EXPR, type, t)))
1235 && ! TREE_OVERFLOW (tem))
1240 return convert (type, TREE_OPERAND (t, 0));
1243 /* - (A - B) -> B - A */
1244 if (! FLOAT_TYPE_P (type) || flag_fast_math)
1245 return convert (type,
1246 fold (build (MINUS_EXPR, TREE_TYPE (t),
1247 TREE_OPERAND (t, 1),
1248 TREE_OPERAND (t, 0))));
1255 return convert (type, build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1258 /* Split a tree IN into a constant, literal and variable parts that could be
1259 combined with CODE to make IN. "constant" means an expression with
1260 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1261 commutative arithmetic operation. Store the constant part into *CONP,
1262 the literal in &LITP and return the variable part. If a part isn't
1263 present, set it to null. If the tree does not decompose in this way,
1264 return the entire tree as the variable part and the other parts as null.
1266 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1267 case, we negate an operand that was subtracted. If NEGATE_P is true, we
1268 are negating all of IN.
1270 If IN is itself a literal or constant, return it as appropriate.
1272 Note that we do not guarantee that any of the three values will be the
1273 same type as IN, but they will have the same signedness and mode. */
1276 split_tree (in, code, conp, litp, negate_p)
1278 enum tree_code code;
1287 /* Strip any conversions that don't change the machine mode or signedness. */
1288 STRIP_SIGN_NOPS (in);
1290 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1292 else if (TREE_CONSTANT (in))
1295 else if (TREE_CODE (in) == code
1296 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1297 /* We can associate addition and subtraction together (even
1298 though the C standard doesn't say so) for integers because
1299 the value is not affected. For reals, the value might be
1300 affected, so we can't. */
1301 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1302 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1304 tree op0 = TREE_OPERAND (in, 0);
1305 tree op1 = TREE_OPERAND (in, 1);
1306 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1307 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1309 /* First see if either of the operands is a literal, then a constant. */
1310 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1311 *litp = op0, op0 = 0;
1312 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1313 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1315 if (op0 != 0 && TREE_CONSTANT (op0))
1316 *conp = op0, op0 = 0;
1317 else if (op1 != 0 && TREE_CONSTANT (op1))
1318 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1320 /* If we haven't dealt with either operand, this is not a case we can
1321 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1322 if (op0 != 0 && op1 != 0)
1327 var = op1, neg_var_p = neg1_p;
1329 /* Now do any needed negations. */
1330 if (neg_litp_p) *litp = negate_expr (*litp);
1331 if (neg_conp_p) *conp = negate_expr (*conp);
1332 if (neg_var_p) var = negate_expr (var);
1339 var = negate_expr (var);
1340 *conp = negate_expr (*conp);
1341 *litp = negate_expr (*litp);
1347 /* Re-associate trees split by the above function. T1 and T2 are either
1348 expressions to associate or null. Return the new expression, if any. If
1349 we build an operation, do it in TYPE and with CODE, except if CODE is a
1350 MINUS_EXPR, in which case we use PLUS_EXPR since split_tree will already
1351 have taken care of the negations. */
1354 associate_trees (t1, t2, code, type)
1356 enum tree_code code;
1364 if (code == MINUS_EXPR)
1367 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1368 try to fold this since we will have infinite recursion. But do
1369 deal with any NEGATE_EXPRs. */
1370 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1371 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1373 if (TREE_CODE (t1) == NEGATE_EXPR)
1374 return build (MINUS_EXPR, type, convert (type, t2),
1375 convert (type, TREE_OPERAND (t1, 0)));
1376 else if (TREE_CODE (t2) == NEGATE_EXPR)
1377 return build (MINUS_EXPR, type, convert (type, t1),
1378 convert (type, TREE_OPERAND (t2, 0)));
1380 return build (code, type, convert (type, t1), convert (type, t2));
1383 return fold (build (code, type, convert (type, t1), convert (type, t2)));
1386 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1387 to produce a new constant.
1389 If NOTRUNC is nonzero, do not truncate the result to fit the data type.
1390 If FORSIZE is nonzero, compute overflow for unsigned types. */
1393 int_const_binop (code, arg1, arg2, notrunc, forsize)
1394 enum tree_code code;
1395 register tree arg1, arg2;
1396 int notrunc, forsize;
1398 HOST_WIDE_INT int1l, int1h, int2l, int2h;
1399 HOST_WIDE_INT low, hi;
1400 HOST_WIDE_INT garbagel, garbageh;
1402 int uns = TREE_UNSIGNED (TREE_TYPE (arg1));
1404 int no_overflow = 0;
1406 int1l = TREE_INT_CST_LOW (arg1);
1407 int1h = TREE_INT_CST_HIGH (arg1);
1408 int2l = TREE_INT_CST_LOW (arg2);
1409 int2h = TREE_INT_CST_HIGH (arg2);
1414 low = int1l | int2l, hi = int1h | int2h;
1418 low = int1l ^ int2l, hi = int1h ^ int2h;
1422 low = int1l & int2l, hi = int1h & int2h;
1425 case BIT_ANDTC_EXPR:
1426 low = int1l & ~int2l, hi = int1h & ~int2h;
1432 /* It's unclear from the C standard whether shifts can overflow.
1433 The following code ignores overflow; perhaps a C standard
1434 interpretation ruling is needed. */
1435 lshift_double (int1l, int1h, int2l,
1436 TYPE_PRECISION (TREE_TYPE (arg1)),
1445 lrotate_double (int1l, int1h, int2l,
1446 TYPE_PRECISION (TREE_TYPE (arg1)),
1451 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1455 neg_double (int2l, int2h, &low, &hi);
1456 add_double (int1l, int1h, low, hi, &low, &hi);
1457 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1461 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1464 case TRUNC_DIV_EXPR:
1465 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1466 case EXACT_DIV_EXPR:
1467 /* This is a shortcut for a common special case. */
1468 if (int2h == 0 && int2l > 0
1469 && ! TREE_CONSTANT_OVERFLOW (arg1)
1470 && ! TREE_CONSTANT_OVERFLOW (arg2)
1471 && int1h == 0 && int1l >= 0)
1473 if (code == CEIL_DIV_EXPR)
1475 low = int1l / int2l, hi = 0;
1479 /* ... fall through ... */
1481 case ROUND_DIV_EXPR:
1482 if (int2h == 0 && int2l == 1)
1484 low = int1l, hi = int1h;
1487 if (int1l == int2l && int1h == int2h
1488 && ! (int1l == 0 && int1h == 0))
1493 overflow = div_and_round_double (code, uns,
1494 int1l, int1h, int2l, int2h,
1495 &low, &hi, &garbagel, &garbageh);
1498 case TRUNC_MOD_EXPR:
1499 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1500 /* This is a shortcut for a common special case. */
1501 if (int2h == 0 && int2l > 0
1502 && ! TREE_CONSTANT_OVERFLOW (arg1)
1503 && ! TREE_CONSTANT_OVERFLOW (arg2)
1504 && int1h == 0 && int1l >= 0)
1506 if (code == CEIL_MOD_EXPR)
1508 low = int1l % int2l, hi = 0;
1512 /* ... fall through ... */
1514 case ROUND_MOD_EXPR:
1515 overflow = div_and_round_double (code, uns,
1516 int1l, int1h, int2l, int2h,
1517 &garbagel, &garbageh, &low, &hi);
1523 low = (((unsigned HOST_WIDE_INT) int1h
1524 < (unsigned HOST_WIDE_INT) int2h)
1525 || (((unsigned HOST_WIDE_INT) int1h
1526 == (unsigned HOST_WIDE_INT) int2h)
1527 && ((unsigned HOST_WIDE_INT) int1l
1528 < (unsigned HOST_WIDE_INT) int2l)));
1530 low = ((int1h < int2h)
1531 || ((int1h == int2h)
1532 && ((unsigned HOST_WIDE_INT) int1l
1533 < (unsigned HOST_WIDE_INT) int2l)));
1535 if (low == (code == MIN_EXPR))
1536 low = int1l, hi = int1h;
1538 low = int2l, hi = int2h;
1545 if (TREE_TYPE (arg1) == sizetype && hi == 0
1547 && (TYPE_MAX_VALUE (sizetype) == NULL
1548 || low <= TREE_INT_CST_LOW (TYPE_MAX_VALUE (sizetype)))
1550 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1554 t = build_int_2 (low, hi);
1555 TREE_TYPE (t) = TREE_TYPE (arg1);
1559 = ((notrunc ? (!uns || forsize) && overflow
1560 : force_fit_type (t, (!uns || forsize) && overflow) && ! no_overflow)
1561 | TREE_OVERFLOW (arg1)
1562 | TREE_OVERFLOW (arg2));
1564 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1565 So check if force_fit_type truncated the value. */
1567 && ! TREE_OVERFLOW (t)
1568 && (TREE_INT_CST_HIGH (t) != hi
1569 || TREE_INT_CST_LOW (t) != low))
1570 TREE_OVERFLOW (t) = 1;
1572 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1573 | TREE_CONSTANT_OVERFLOW (arg1)
1574 | TREE_CONSTANT_OVERFLOW (arg2));
1578 /* Define input and output argument for const_binop_1. */
1581 enum tree_code code; /* Input: tree code for operation*/
1582 tree type; /* Input: tree type for operation. */
1583 REAL_VALUE_TYPE d1, d2; /* Input: floating point operands. */
1584 tree t; /* Output: constant for result. */
1587 /* Do the real arithmetic for const_binop while protected by a
1588 float overflow handler. */
1591 const_binop_1 (data)
1594 struct cb_args *args = (struct cb_args *) data;
1595 REAL_VALUE_TYPE value;
1597 #ifdef REAL_ARITHMETIC
1598 REAL_ARITHMETIC (value, args->code, args->d1, args->d2);
1603 value = args->d1 + args->d2;
1607 value = args->d1 - args->d2;
1611 value = args->d1 * args->d2;
1615 #ifndef REAL_INFINITY
1620 value = args->d1 / args->d2;
1624 value = MIN (args->d1, args->d2);
1628 value = MAX (args->d1, args->d2);
1634 #endif /* no REAL_ARITHMETIC */
1637 = build_real (args->type,
1638 real_value_truncate (TYPE_MODE (args->type), value));
1641 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1642 constant. We assume ARG1 and ARG2 have the same data type, or at least
1643 are the same kind of constant and the same machine mode.
1645 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1648 const_binop (code, arg1, arg2, notrunc)
1649 enum tree_code code;
1650 register tree arg1, arg2;
1653 STRIP_NOPS (arg1); STRIP_NOPS (arg2);
1655 if (TREE_CODE (arg1) == INTEGER_CST)
1656 return int_const_binop (code, arg1, arg2, notrunc, 0);
1658 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1659 if (TREE_CODE (arg1) == REAL_CST)
1665 struct cb_args args;
1667 d1 = TREE_REAL_CST (arg1);
1668 d2 = TREE_REAL_CST (arg2);
1670 /* If either operand is a NaN, just return it. Otherwise, set up
1671 for floating-point trap; we return an overflow. */
1672 if (REAL_VALUE_ISNAN (d1))
1674 else if (REAL_VALUE_ISNAN (d2))
1677 /* Setup input for const_binop_1() */
1678 args.type = TREE_TYPE (arg1);
1683 if (do_float_handler (const_binop_1, (PTR) &args))
1684 /* Receive output from const_binop_1. */
1688 /* We got an exception from const_binop_1. */
1689 t = copy_node (arg1);
1694 = (force_fit_type (t, overflow)
1695 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1696 TREE_CONSTANT_OVERFLOW (t)
1698 | TREE_CONSTANT_OVERFLOW (arg1)
1699 | TREE_CONSTANT_OVERFLOW (arg2);
1702 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1703 if (TREE_CODE (arg1) == COMPLEX_CST)
1705 register tree type = TREE_TYPE (arg1);
1706 register tree r1 = TREE_REALPART (arg1);
1707 register tree i1 = TREE_IMAGPART (arg1);
1708 register tree r2 = TREE_REALPART (arg2);
1709 register tree i2 = TREE_IMAGPART (arg2);
1715 t = build_complex (type,
1716 const_binop (PLUS_EXPR, r1, r2, notrunc),
1717 const_binop (PLUS_EXPR, i1, i2, notrunc));
1721 t = build_complex (type,
1722 const_binop (MINUS_EXPR, r1, r2, notrunc),
1723 const_binop (MINUS_EXPR, i1, i2, notrunc));
1727 t = build_complex (type,
1728 const_binop (MINUS_EXPR,
1729 const_binop (MULT_EXPR,
1731 const_binop (MULT_EXPR,
1734 const_binop (PLUS_EXPR,
1735 const_binop (MULT_EXPR,
1737 const_binop (MULT_EXPR,
1744 register tree magsquared
1745 = const_binop (PLUS_EXPR,
1746 const_binop (MULT_EXPR, r2, r2, notrunc),
1747 const_binop (MULT_EXPR, i2, i2, notrunc),
1750 t = build_complex (type,
1752 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1753 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1754 const_binop (PLUS_EXPR,
1755 const_binop (MULT_EXPR, r1, r2,
1757 const_binop (MULT_EXPR, i1, i2,
1760 magsquared, notrunc),
1762 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1763 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1764 const_binop (MINUS_EXPR,
1765 const_binop (MULT_EXPR, i1, r2,
1767 const_binop (MULT_EXPR, r1, i2,
1770 magsquared, notrunc));
1782 /* Return an INTEGER_CST with value whose HOST_BITS_PER_WIDE_INT bits are
1783 given by HIGH and whose HOST_BITS_PER_WIDE_INT bits are given by NUMBER.
1785 If BIT_P is nonzero, this represents a size in bit and the type of the
1786 result will be bitsizetype, othewise it represents a size in bytes and
1787 the type of the result will be sizetype. */
1790 size_int_wide (number, high, bit_p)
1791 unsigned HOST_WIDE_INT number, high;
1794 /* Type-size nodes already made for small sizes. */
1795 static tree size_table[2 * HOST_BITS_PER_WIDE_INT + 1][2];
1796 static int init_p = 0;
1799 if (ggc_p && ! init_p)
1801 ggc_add_tree_root ((tree *) size_table,
1802 sizeof size_table / sizeof (tree));
1806 if (number < 2*HOST_BITS_PER_WIDE_INT + 1 && high == 0
1807 && size_table[number][bit_p] != 0)
1808 return size_table[number][bit_p];
1810 if (number < 2*HOST_BITS_PER_WIDE_INT + 1 && high == 0)
1814 /* Make this a permanent node. */
1815 push_obstacks_nochange ();
1816 end_temporary_allocation ();
1819 t = build_int_2 (number, 0);
1820 TREE_TYPE (t) = bit_p ? bitsizetype : sizetype;
1821 size_table[number][bit_p] = t;
1829 t = build_int_2 (number, high);
1830 TREE_TYPE (t) = bit_p ? bitsizetype : sizetype;
1831 TREE_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (t) = force_fit_type (t, 0);
1835 /* Combine operands OP1 and OP2 with arithmetic operation CODE.
1836 CODE is a tree code. Data type is taken from `sizetype',
1837 If the operands are constant, so is the result. */
1840 size_binop (code, arg0, arg1)
1841 enum tree_code code;
1844 /* Handle the special case of two integer constants faster. */
1845 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1847 /* And some specific cases even faster than that. */
1848 if (code == PLUS_EXPR && integer_zerop (arg0))
1850 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1851 && integer_zerop (arg1))
1853 else if (code == MULT_EXPR && integer_onep (arg0))
1856 /* Handle general case of two integer constants. */
1857 return int_const_binop (code, arg0, arg1, 0, 1);
1860 if (arg0 == error_mark_node || arg1 == error_mark_node)
1861 return error_mark_node;
1863 return fold (build (code, sizetype, arg0, arg1));
1866 /* Combine operands OP1 and OP2 with arithmetic operation CODE.
1867 CODE is a tree code. Data type is taken from `ssizetype',
1868 If the operands are constant, so is the result. */
1871 ssize_binop (code, arg0, arg1)
1872 enum tree_code code;
1875 /* Handle the special case of two integer constants faster. */
1876 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1878 /* And some specific cases even faster than that. */
1879 if (code == PLUS_EXPR && integer_zerop (arg0))
1881 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1882 && integer_zerop (arg1))
1884 else if (code == MULT_EXPR && integer_onep (arg0))
1887 /* Handle general case of two integer constants. We convert
1888 arg0 to ssizetype because int_const_binop uses its type for the
1890 arg0 = convert (ssizetype, arg0);
1891 return int_const_binop (code, arg0, arg1, 0, 0);
1894 if (arg0 == error_mark_node || arg1 == error_mark_node)
1895 return error_mark_node;
1897 return fold (build (code, ssizetype, arg0, arg1));
1900 /* This structure is used to communicate arguments to fold_convert_1. */
1903 tree arg1; /* Input: value to convert. */
1904 tree type; /* Input: type to convert value to. */
1905 tree t; /* Ouput: result of conversion. */
1908 /* Function to convert floating-point constants, protected by floating
1909 point exception handler. */
1912 fold_convert_1 (data)
1915 struct fc_args * args = (struct fc_args *) data;
1917 args->t = build_real (args->type,
1918 real_value_truncate (TYPE_MODE (args->type),
1919 TREE_REAL_CST (args->arg1)));
1922 /* Given T, a tree representing type conversion of ARG1, a constant,
1923 return a constant tree representing the result of conversion. */
1926 fold_convert (t, arg1)
1930 register tree type = TREE_TYPE (t);
1933 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1935 if (TREE_CODE (arg1) == INTEGER_CST)
1937 /* If we would build a constant wider than GCC supports,
1938 leave the conversion unfolded. */
1939 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1942 /* Given an integer constant, make new constant with new type,
1943 appropriately sign-extended or truncated. */
1944 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1945 TREE_INT_CST_HIGH (arg1));
1946 TREE_TYPE (t) = type;
1947 /* Indicate an overflow if (1) ARG1 already overflowed,
1948 or (2) force_fit_type indicates an overflow.
1949 Tell force_fit_type that an overflow has already occurred
1950 if ARG1 is a too-large unsigned value and T is signed.
1951 But don't indicate an overflow if converting a pointer. */
1953 = ((force_fit_type (t,
1954 (TREE_INT_CST_HIGH (arg1) < 0
1955 && (TREE_UNSIGNED (type)
1956 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
1957 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1958 || TREE_OVERFLOW (arg1));
1959 TREE_CONSTANT_OVERFLOW (t)
1960 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1962 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1963 else if (TREE_CODE (arg1) == REAL_CST)
1965 /* Don't initialize these, use assignments.
1966 Initialized local aggregates don't work on old compilers. */
1970 tree type1 = TREE_TYPE (arg1);
1973 x = TREE_REAL_CST (arg1);
1974 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
1976 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
1977 if (!no_upper_bound)
1978 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
1980 /* See if X will be in range after truncation towards 0.
1981 To compensate for truncation, move the bounds away from 0,
1982 but reject if X exactly equals the adjusted bounds. */
1983 #ifdef REAL_ARITHMETIC
1984 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
1985 if (!no_upper_bound)
1986 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
1989 if (!no_upper_bound)
1992 /* If X is a NaN, use zero instead and show we have an overflow.
1993 Otherwise, range check. */
1994 if (REAL_VALUE_ISNAN (x))
1995 overflow = 1, x = dconst0;
1996 else if (! (REAL_VALUES_LESS (l, x)
1998 && REAL_VALUES_LESS (x, u)))
2001 #ifndef REAL_ARITHMETIC
2003 HOST_WIDE_INT low, high;
2004 HOST_WIDE_INT half_word
2005 = (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2);
2010 high = (HOST_WIDE_INT) (x / half_word / half_word);
2011 x -= (REAL_VALUE_TYPE) high * half_word * half_word;
2012 if (x >= (REAL_VALUE_TYPE) half_word * half_word / 2)
2014 low = x - (REAL_VALUE_TYPE) half_word * half_word / 2;
2015 low |= (HOST_WIDE_INT) -1 << (HOST_BITS_PER_WIDE_INT - 1);
2018 low = (HOST_WIDE_INT) x;
2019 if (TREE_REAL_CST (arg1) < 0)
2020 neg_double (low, high, &low, &high);
2021 t = build_int_2 (low, high);
2025 HOST_WIDE_INT low, high;
2026 REAL_VALUE_TO_INT (&low, &high, x);
2027 t = build_int_2 (low, high);
2030 TREE_TYPE (t) = type;
2032 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
2033 TREE_CONSTANT_OVERFLOW (t)
2034 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2036 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2037 TREE_TYPE (t) = type;
2039 else if (TREE_CODE (type) == REAL_TYPE)
2041 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2042 if (TREE_CODE (arg1) == INTEGER_CST)
2043 return build_real_from_int_cst (type, arg1);
2044 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2045 if (TREE_CODE (arg1) == REAL_CST)
2047 struct fc_args args;
2049 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
2052 TREE_TYPE (arg1) = type;
2056 /* Setup input for fold_convert_1() */
2060 if (do_float_handler (fold_convert_1, (PTR) &args))
2062 /* Receive output from fold_convert_1() */
2067 /* We got an exception from fold_convert_1() */
2069 t = copy_node (arg1);
2073 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
2074 TREE_CONSTANT_OVERFLOW (t)
2075 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2079 TREE_CONSTANT (t) = 1;
2083 /* Return an expr equal to X but certainly not valid as an lvalue. */
2091 /* These things are certainly not lvalues. */
2092 if (TREE_CODE (x) == NON_LVALUE_EXPR
2093 || TREE_CODE (x) == INTEGER_CST
2094 || TREE_CODE (x) == REAL_CST
2095 || TREE_CODE (x) == STRING_CST
2096 || TREE_CODE (x) == ADDR_EXPR)
2099 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2100 TREE_CONSTANT (result) = TREE_CONSTANT (x);
2104 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2105 Zero means allow extended lvalues. */
2107 int pedantic_lvalues;
2109 /* When pedantic, return an expr equal to X but certainly not valid as a
2110 pedantic lvalue. Otherwise, return X. */
2113 pedantic_non_lvalue (x)
2116 if (pedantic_lvalues)
2117 return non_lvalue (x);
2122 /* Given a tree comparison code, return the code that is the logical inverse
2123 of the given code. It is not safe to do this for floating-point
2124 comparisons, except for NE_EXPR and EQ_EXPR. */
2126 static enum tree_code
2127 invert_tree_comparison (code)
2128 enum tree_code code;
2149 /* Similar, but return the comparison that results if the operands are
2150 swapped. This is safe for floating-point. */
2152 static enum tree_code
2153 swap_tree_comparison (code)
2154 enum tree_code code;
2174 /* Return nonzero if CODE is a tree code that represents a truth value. */
2177 truth_value_p (code)
2178 enum tree_code code;
2180 return (TREE_CODE_CLASS (code) == '<'
2181 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2182 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2183 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2186 /* Return nonzero if two operands are necessarily equal.
2187 If ONLY_CONST is non-zero, only return non-zero for constants.
2188 This function tests whether the operands are indistinguishable;
2189 it does not test whether they are equal using C's == operation.
2190 The distinction is important for IEEE floating point, because
2191 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2192 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
2195 operand_equal_p (arg0, arg1, only_const)
2199 /* If both types don't have the same signedness, then we can't consider
2200 them equal. We must check this before the STRIP_NOPS calls
2201 because they may change the signedness of the arguments. */
2202 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
2208 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2209 /* This is needed for conversions and for COMPONENT_REF.
2210 Might as well play it safe and always test this. */
2211 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2212 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2213 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2216 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2217 We don't care about side effects in that case because the SAVE_EXPR
2218 takes care of that for us. In all other cases, two expressions are
2219 equal if they have no side effects. If we have two identical
2220 expressions with side effects that should be treated the same due
2221 to the only side effects being identical SAVE_EXPR's, that will
2222 be detected in the recursive calls below. */
2223 if (arg0 == arg1 && ! only_const
2224 && (TREE_CODE (arg0) == SAVE_EXPR
2225 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2228 /* Next handle constant cases, those for which we can return 1 even
2229 if ONLY_CONST is set. */
2230 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2231 switch (TREE_CODE (arg0))
2234 return (! TREE_CONSTANT_OVERFLOW (arg0)
2235 && ! TREE_CONSTANT_OVERFLOW (arg1)
2236 && TREE_INT_CST_LOW (arg0) == TREE_INT_CST_LOW (arg1)
2237 && TREE_INT_CST_HIGH (arg0) == TREE_INT_CST_HIGH (arg1));
2240 return (! TREE_CONSTANT_OVERFLOW (arg0)
2241 && ! TREE_CONSTANT_OVERFLOW (arg1)
2242 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2243 TREE_REAL_CST (arg1)));
2246 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2248 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2252 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2253 && ! memcmp (TREE_STRING_POINTER (arg0),
2254 TREE_STRING_POINTER (arg1),
2255 TREE_STRING_LENGTH (arg0)));
2258 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2267 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2270 /* Two conversions are equal only if signedness and modes match. */
2271 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2272 && (TREE_UNSIGNED (TREE_TYPE (arg0))
2273 != TREE_UNSIGNED (TREE_TYPE (arg1))))
2276 return operand_equal_p (TREE_OPERAND (arg0, 0),
2277 TREE_OPERAND (arg1, 0), 0);
2281 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
2282 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
2286 /* For commutative ops, allow the other order. */
2287 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
2288 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
2289 || TREE_CODE (arg0) == BIT_IOR_EXPR
2290 || TREE_CODE (arg0) == BIT_XOR_EXPR
2291 || TREE_CODE (arg0) == BIT_AND_EXPR
2292 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
2293 && operand_equal_p (TREE_OPERAND (arg0, 0),
2294 TREE_OPERAND (arg1, 1), 0)
2295 && operand_equal_p (TREE_OPERAND (arg0, 1),
2296 TREE_OPERAND (arg1, 0), 0));
2299 /* If either of the pointer (or reference) expressions we are dereferencing
2300 contain a side effect, these cannot be equal. */
2301 if (TREE_SIDE_EFFECTS (arg0)
2302 || TREE_SIDE_EFFECTS (arg1))
2305 switch (TREE_CODE (arg0))
2308 return operand_equal_p (TREE_OPERAND (arg0, 0),
2309 TREE_OPERAND (arg1, 0), 0);
2313 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2314 TREE_OPERAND (arg1, 0), 0)
2315 && operand_equal_p (TREE_OPERAND (arg0, 1),
2316 TREE_OPERAND (arg1, 1), 0));
2319 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2320 TREE_OPERAND (arg1, 0), 0)
2321 && operand_equal_p (TREE_OPERAND (arg0, 1),
2322 TREE_OPERAND (arg1, 1), 0)
2323 && operand_equal_p (TREE_OPERAND (arg0, 2),
2324 TREE_OPERAND (arg1, 2), 0));
2330 if (TREE_CODE (arg0) == RTL_EXPR)
2331 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2339 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2340 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2342 When in doubt, return 0. */
2345 operand_equal_for_comparison_p (arg0, arg1, other)
2349 int unsignedp1, unsignedpo;
2350 tree primarg0, primarg1, primother;
2351 unsigned correct_width;
2353 if (operand_equal_p (arg0, arg1, 0))
2356 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2357 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2360 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2361 and see if the inner values are the same. This removes any
2362 signedness comparison, which doesn't matter here. */
2363 primarg0 = arg0, primarg1 = arg1;
2364 STRIP_NOPS (primarg0); STRIP_NOPS (primarg1);
2365 if (operand_equal_p (primarg0, primarg1, 0))
2368 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2369 actual comparison operand, ARG0.
2371 First throw away any conversions to wider types
2372 already present in the operands. */
2374 primarg1 = get_narrower (arg1, &unsignedp1);
2375 primother = get_narrower (other, &unsignedpo);
2377 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2378 if (unsignedp1 == unsignedpo
2379 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2380 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2382 tree type = TREE_TYPE (arg0);
2384 /* Make sure shorter operand is extended the right way
2385 to match the longer operand. */
2386 primarg1 = convert (signed_or_unsigned_type (unsignedp1,
2387 TREE_TYPE (primarg1)),
2390 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2397 /* See if ARG is an expression that is either a comparison or is performing
2398 arithmetic on comparisons. The comparisons must only be comparing
2399 two different values, which will be stored in *CVAL1 and *CVAL2; if
2400 they are non-zero it means that some operands have already been found.
2401 No variables may be used anywhere else in the expression except in the
2402 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2403 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2405 If this is true, return 1. Otherwise, return zero. */
2408 twoval_comparison_p (arg, cval1, cval2, save_p)
2410 tree *cval1, *cval2;
2413 enum tree_code code = TREE_CODE (arg);
2414 char class = TREE_CODE_CLASS (code);
2416 /* We can handle some of the 'e' cases here. */
2417 if (class == 'e' && code == TRUTH_NOT_EXPR)
2419 else if (class == 'e'
2420 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2421 || code == COMPOUND_EXPR))
2424 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2425 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2427 /* If we've already found a CVAL1 or CVAL2, this expression is
2428 two complex to handle. */
2429 if (*cval1 || *cval2)
2439 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2442 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2443 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2444 cval1, cval2, save_p));
2450 if (code == COND_EXPR)
2451 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2452 cval1, cval2, save_p)
2453 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2454 cval1, cval2, save_p)
2455 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2456 cval1, cval2, save_p));
2460 /* First see if we can handle the first operand, then the second. For
2461 the second operand, we know *CVAL1 can't be zero. It must be that
2462 one side of the comparison is each of the values; test for the
2463 case where this isn't true by failing if the two operands
2466 if (operand_equal_p (TREE_OPERAND (arg, 0),
2467 TREE_OPERAND (arg, 1), 0))
2471 *cval1 = TREE_OPERAND (arg, 0);
2472 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2474 else if (*cval2 == 0)
2475 *cval2 = TREE_OPERAND (arg, 0);
2476 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2481 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2483 else if (*cval2 == 0)
2484 *cval2 = TREE_OPERAND (arg, 1);
2485 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2497 /* ARG is a tree that is known to contain just arithmetic operations and
2498 comparisons. Evaluate the operations in the tree substituting NEW0 for
2499 any occurrence of OLD0 as an operand of a comparison and likewise for
2503 eval_subst (arg, old0, new0, old1, new1)
2505 tree old0, new0, old1, new1;
2507 tree type = TREE_TYPE (arg);
2508 enum tree_code code = TREE_CODE (arg);
2509 char class = TREE_CODE_CLASS (code);
2511 /* We can handle some of the 'e' cases here. */
2512 if (class == 'e' && code == TRUTH_NOT_EXPR)
2514 else if (class == 'e'
2515 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2521 return fold (build1 (code, type,
2522 eval_subst (TREE_OPERAND (arg, 0),
2523 old0, new0, old1, new1)));
2526 return fold (build (code, type,
2527 eval_subst (TREE_OPERAND (arg, 0),
2528 old0, new0, old1, new1),
2529 eval_subst (TREE_OPERAND (arg, 1),
2530 old0, new0, old1, new1)));
2536 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2539 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2542 return fold (build (code, type,
2543 eval_subst (TREE_OPERAND (arg, 0),
2544 old0, new0, old1, new1),
2545 eval_subst (TREE_OPERAND (arg, 1),
2546 old0, new0, old1, new1),
2547 eval_subst (TREE_OPERAND (arg, 2),
2548 old0, new0, old1, new1)));
2552 /* fall through - ??? */
2556 tree arg0 = TREE_OPERAND (arg, 0);
2557 tree arg1 = TREE_OPERAND (arg, 1);
2559 /* We need to check both for exact equality and tree equality. The
2560 former will be true if the operand has a side-effect. In that
2561 case, we know the operand occurred exactly once. */
2563 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2565 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2568 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2570 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2573 return fold (build (code, type, arg0, arg1));
2581 /* Return a tree for the case when the result of an expression is RESULT
2582 converted to TYPE and OMITTED was previously an operand of the expression
2583 but is now not needed (e.g., we folded OMITTED * 0).
2585 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2586 the conversion of RESULT to TYPE. */
2589 omit_one_operand (type, result, omitted)
2590 tree type, result, omitted;
2592 tree t = convert (type, result);
2594 if (TREE_SIDE_EFFECTS (omitted))
2595 return build (COMPOUND_EXPR, type, omitted, t);
2597 return non_lvalue (t);
2600 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2603 pedantic_omit_one_operand (type, result, omitted)
2604 tree type, result, omitted;
2606 tree t = convert (type, result);
2608 if (TREE_SIDE_EFFECTS (omitted))
2609 return build (COMPOUND_EXPR, type, omitted, t);
2611 return pedantic_non_lvalue (t);
2616 /* Return a simplified tree node for the truth-negation of ARG. This
2617 never alters ARG itself. We assume that ARG is an operation that
2618 returns a truth value (0 or 1). */
2621 invert_truthvalue (arg)
2624 tree type = TREE_TYPE (arg);
2625 enum tree_code code = TREE_CODE (arg);
2627 if (code == ERROR_MARK)
2630 /* If this is a comparison, we can simply invert it, except for
2631 floating-point non-equality comparisons, in which case we just
2632 enclose a TRUTH_NOT_EXPR around what we have. */
2634 if (TREE_CODE_CLASS (code) == '<')
2636 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2637 && !flag_fast_math && code != NE_EXPR && code != EQ_EXPR)
2638 return build1 (TRUTH_NOT_EXPR, type, arg);
2640 return build (invert_tree_comparison (code), type,
2641 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2647 return convert (type, build_int_2 (TREE_INT_CST_LOW (arg) == 0
2648 && TREE_INT_CST_HIGH (arg) == 0, 0));
2650 case TRUTH_AND_EXPR:
2651 return build (TRUTH_OR_EXPR, type,
2652 invert_truthvalue (TREE_OPERAND (arg, 0)),
2653 invert_truthvalue (TREE_OPERAND (arg, 1)));
2656 return build (TRUTH_AND_EXPR, type,
2657 invert_truthvalue (TREE_OPERAND (arg, 0)),
2658 invert_truthvalue (TREE_OPERAND (arg, 1)));
2660 case TRUTH_XOR_EXPR:
2661 /* Here we can invert either operand. We invert the first operand
2662 unless the second operand is a TRUTH_NOT_EXPR in which case our
2663 result is the XOR of the first operand with the inside of the
2664 negation of the second operand. */
2666 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2667 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2668 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2670 return build (TRUTH_XOR_EXPR, type,
2671 invert_truthvalue (TREE_OPERAND (arg, 0)),
2672 TREE_OPERAND (arg, 1));
2674 case TRUTH_ANDIF_EXPR:
2675 return build (TRUTH_ORIF_EXPR, type,
2676 invert_truthvalue (TREE_OPERAND (arg, 0)),
2677 invert_truthvalue (TREE_OPERAND (arg, 1)));
2679 case TRUTH_ORIF_EXPR:
2680 return build (TRUTH_ANDIF_EXPR, type,
2681 invert_truthvalue (TREE_OPERAND (arg, 0)),
2682 invert_truthvalue (TREE_OPERAND (arg, 1)));
2684 case TRUTH_NOT_EXPR:
2685 return TREE_OPERAND (arg, 0);
2688 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2689 invert_truthvalue (TREE_OPERAND (arg, 1)),
2690 invert_truthvalue (TREE_OPERAND (arg, 2)));
2693 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2694 invert_truthvalue (TREE_OPERAND (arg, 1)));
2696 case WITH_RECORD_EXPR:
2697 return build (WITH_RECORD_EXPR, type,
2698 invert_truthvalue (TREE_OPERAND (arg, 0)),
2699 TREE_OPERAND (arg, 1));
2701 case NON_LVALUE_EXPR:
2702 return invert_truthvalue (TREE_OPERAND (arg, 0));
2707 return build1 (TREE_CODE (arg), type,
2708 invert_truthvalue (TREE_OPERAND (arg, 0)));
2711 if (!integer_onep (TREE_OPERAND (arg, 1)))
2713 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2716 return build1 (TRUTH_NOT_EXPR, type, arg);
2718 case CLEANUP_POINT_EXPR:
2719 return build1 (CLEANUP_POINT_EXPR, type,
2720 invert_truthvalue (TREE_OPERAND (arg, 0)));
2725 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2727 return build1 (TRUTH_NOT_EXPR, type, arg);
2730 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2731 operands are another bit-wise operation with a common input. If so,
2732 distribute the bit operations to save an operation and possibly two if
2733 constants are involved. For example, convert
2734 (A | B) & (A | C) into A | (B & C)
2735 Further simplification will occur if B and C are constants.
2737 If this optimization cannot be done, 0 will be returned. */
2740 distribute_bit_expr (code, type, arg0, arg1)
2741 enum tree_code code;
2748 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2749 || TREE_CODE (arg0) == code
2750 || (TREE_CODE (arg0) != BIT_AND_EXPR
2751 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2754 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2756 common = TREE_OPERAND (arg0, 0);
2757 left = TREE_OPERAND (arg0, 1);
2758 right = TREE_OPERAND (arg1, 1);
2760 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2762 common = TREE_OPERAND (arg0, 0);
2763 left = TREE_OPERAND (arg0, 1);
2764 right = TREE_OPERAND (arg1, 0);
2766 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2768 common = TREE_OPERAND (arg0, 1);
2769 left = TREE_OPERAND (arg0, 0);
2770 right = TREE_OPERAND (arg1, 1);
2772 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2774 common = TREE_OPERAND (arg0, 1);
2775 left = TREE_OPERAND (arg0, 0);
2776 right = TREE_OPERAND (arg1, 0);
2781 return fold (build (TREE_CODE (arg0), type, common,
2782 fold (build (code, type, left, right))));
2785 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2786 starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */
2789 make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp)
2792 int bitsize, bitpos;
2795 tree result = build (BIT_FIELD_REF, type, inner,
2796 size_int (bitsize), bitsize_int (bitpos, 0L));
2798 TREE_UNSIGNED (result) = unsignedp;
2803 /* Optimize a bit-field compare.
2805 There are two cases: First is a compare against a constant and the
2806 second is a comparison of two items where the fields are at the same
2807 bit position relative to the start of a chunk (byte, halfword, word)
2808 large enough to contain it. In these cases we can avoid the shift
2809 implicit in bitfield extractions.
2811 For constants, we emit a compare of the shifted constant with the
2812 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2813 compared. For two fields at the same position, we do the ANDs with the
2814 similar mask and compare the result of the ANDs.
2816 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2817 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2818 are the left and right operands of the comparison, respectively.
2820 If the optimization described above can be done, we return the resulting
2821 tree. Otherwise we return zero. */
2824 optimize_bit_field_compare (code, compare_type, lhs, rhs)
2825 enum tree_code code;
2829 int lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2830 tree type = TREE_TYPE (lhs);
2831 tree signed_type, unsigned_type;
2832 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2833 enum machine_mode lmode, rmode, nmode;
2834 int lunsignedp, runsignedp;
2835 int lvolatilep = 0, rvolatilep = 0;
2837 tree linner, rinner = NULL_TREE;
2841 /* Get all the information about the extractions being done. If the bit size
2842 if the same as the size of the underlying object, we aren't doing an
2843 extraction at all and so can do nothing. We also don't want to
2844 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2845 then will no longer be able to replace it. */
2846 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2847 &lunsignedp, &lvolatilep, &alignment);
2848 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2849 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2854 /* If this is not a constant, we can only do something if bit positions,
2855 sizes, and signedness are the same. */
2856 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2857 &runsignedp, &rvolatilep, &alignment);
2859 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2860 || lunsignedp != runsignedp || offset != 0
2861 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2865 /* See if we can find a mode to refer to this field. We should be able to,
2866 but fail if we can't. */
2867 nmode = get_best_mode (lbitsize, lbitpos,
2868 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2869 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2870 TYPE_ALIGN (TREE_TYPE (rinner))),
2871 word_mode, lvolatilep || rvolatilep);
2872 if (nmode == VOIDmode)
2875 /* Set signed and unsigned types of the precision of this mode for the
2877 signed_type = type_for_mode (nmode, 0);
2878 unsigned_type = type_for_mode (nmode, 1);
2880 /* Compute the bit position and size for the new reference and our offset
2881 within it. If the new reference is the same size as the original, we
2882 won't optimize anything, so return zero. */
2883 nbitsize = GET_MODE_BITSIZE (nmode);
2884 nbitpos = lbitpos & ~ (nbitsize - 1);
2886 if (nbitsize == lbitsize)
2889 if (BYTES_BIG_ENDIAN)
2890 lbitpos = nbitsize - lbitsize - lbitpos;
2892 /* Make the mask to be used against the extracted field. */
2893 mask = build_int_2 (~0, ~0);
2894 TREE_TYPE (mask) = unsigned_type;
2895 force_fit_type (mask, 0);
2896 mask = convert (unsigned_type, mask);
2897 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2898 mask = const_binop (RSHIFT_EXPR, mask,
2899 size_int (nbitsize - lbitsize - lbitpos), 0);
2902 /* If not comparing with constant, just rework the comparison
2904 return build (code, compare_type,
2905 build (BIT_AND_EXPR, unsigned_type,
2906 make_bit_field_ref (linner, unsigned_type,
2907 nbitsize, nbitpos, 1),
2909 build (BIT_AND_EXPR, unsigned_type,
2910 make_bit_field_ref (rinner, unsigned_type,
2911 nbitsize, nbitpos, 1),
2914 /* Otherwise, we are handling the constant case. See if the constant is too
2915 big for the field. Warn and return a tree of for 0 (false) if so. We do
2916 this not only for its own sake, but to avoid having to test for this
2917 error case below. If we didn't, we might generate wrong code.
2919 For unsigned fields, the constant shifted right by the field length should
2920 be all zero. For signed fields, the high-order bits should agree with
2925 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2926 convert (unsigned_type, rhs),
2927 size_int (lbitsize), 0)))
2929 warning ("comparison is always %d due to width of bitfield",
2931 return convert (compare_type,
2933 ? integer_one_node : integer_zero_node));
2938 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
2939 size_int (lbitsize - 1), 0);
2940 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2942 warning ("comparison is always %d due to width of bitfield",
2944 return convert (compare_type,
2946 ? integer_one_node : integer_zero_node));
2950 /* Single-bit compares should always be against zero. */
2951 if (lbitsize == 1 && ! integer_zerop (rhs))
2953 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2954 rhs = convert (type, integer_zero_node);
2957 /* Make a new bitfield reference, shift the constant over the
2958 appropriate number of bits and mask it with the computed mask
2959 (in case this was a signed field). If we changed it, make a new one. */
2960 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
2963 TREE_SIDE_EFFECTS (lhs) = 1;
2964 TREE_THIS_VOLATILE (lhs) = 1;
2967 rhs = fold (const_binop (BIT_AND_EXPR,
2968 const_binop (LSHIFT_EXPR,
2969 convert (unsigned_type, rhs),
2970 size_int (lbitpos), 0),
2973 return build (code, compare_type,
2974 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2978 /* Subroutine for fold_truthop: decode a field reference.
2980 If EXP is a comparison reference, we return the innermost reference.
2982 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2983 set to the starting bit number.
2985 If the innermost field can be completely contained in a mode-sized
2986 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2988 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2989 otherwise it is not changed.
2991 *PUNSIGNEDP is set to the signedness of the field.
2993 *PMASK is set to the mask used. This is either contained in a
2994 BIT_AND_EXPR or derived from the width of the field.
2996 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2998 Return 0 if this is not a component reference or is one that we can't
2999 do anything with. */
3002 decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp,
3003 pvolatilep, pmask, pand_mask)
3005 int *pbitsize, *pbitpos;
3006 enum machine_mode *pmode;
3007 int *punsignedp, *pvolatilep;
3012 tree mask, inner, offset;
3017 /* All the optimizations using this function assume integer fields.
3018 There are problems with FP fields since the type_for_size call
3019 below can fail for, e.g., XFmode. */
3020 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3025 if (TREE_CODE (exp) == BIT_AND_EXPR)
3027 and_mask = TREE_OPERAND (exp, 1);
3028 exp = TREE_OPERAND (exp, 0);
3029 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3030 if (TREE_CODE (and_mask) != INTEGER_CST)
3035 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3036 punsignedp, pvolatilep, &alignment);
3037 if ((inner == exp && and_mask == 0)
3038 || *pbitsize < 0 || offset != 0
3039 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3042 /* Compute the mask to access the bitfield. */
3043 unsigned_type = type_for_size (*pbitsize, 1);
3044 precision = TYPE_PRECISION (unsigned_type);
3046 mask = build_int_2 (~0, ~0);
3047 TREE_TYPE (mask) = unsigned_type;
3048 force_fit_type (mask, 0);
3049 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3050 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3052 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3054 mask = fold (build (BIT_AND_EXPR, unsigned_type,
3055 convert (unsigned_type, and_mask), mask));
3058 *pand_mask = and_mask;
3062 /* Return non-zero if MASK represents a mask of SIZE ones in the low-order
3066 all_ones_mask_p (mask, size)
3070 tree type = TREE_TYPE (mask);
3071 int precision = TYPE_PRECISION (type);
3074 tmask = build_int_2 (~0, ~0);
3075 TREE_TYPE (tmask) = signed_type (type);
3076 force_fit_type (tmask, 0);
3078 tree_int_cst_equal (mask,
3079 const_binop (RSHIFT_EXPR,
3080 const_binop (LSHIFT_EXPR, tmask,
3081 size_int (precision - size),
3083 size_int (precision - size), 0));
3086 /* Subroutine for fold_truthop: determine if an operand is simple enough
3087 to be evaluated unconditionally. */
3090 simple_operand_p (exp)
3093 /* Strip any conversions that don't change the machine mode. */
3094 while ((TREE_CODE (exp) == NOP_EXPR
3095 || TREE_CODE (exp) == CONVERT_EXPR)
3096 && (TYPE_MODE (TREE_TYPE (exp))
3097 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
3098 exp = TREE_OPERAND (exp, 0);
3100 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
3101 || (TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
3102 && ! TREE_ADDRESSABLE (exp)
3103 && ! TREE_THIS_VOLATILE (exp)
3104 && ! DECL_NONLOCAL (exp)
3105 /* Don't regard global variables as simple. They may be
3106 allocated in ways unknown to the compiler (shared memory,
3107 #pragma weak, etc). */
3108 && ! TREE_PUBLIC (exp)
3109 && ! DECL_EXTERNAL (exp)
3110 /* Loading a static variable is unduly expensive, but global
3111 registers aren't expensive. */
3112 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3115 /* The following functions are subroutines to fold_range_test and allow it to
3116 try to change a logical combination of comparisons into a range test.
3119 X == 2 && X == 3 && X == 4 && X == 5
3123 (unsigned) (X - 2) <= 3
3125 We describe each set of comparisons as being either inside or outside
3126 a range, using a variable named like IN_P, and then describe the
3127 range with a lower and upper bound. If one of the bounds is omitted,
3128 it represents either the highest or lowest value of the type.
3130 In the comments below, we represent a range by two numbers in brackets
3131 preceded by a "+" to designate being inside that range, or a "-" to
3132 designate being outside that range, so the condition can be inverted by
3133 flipping the prefix. An omitted bound is represented by a "-". For
3134 example, "- [-, 10]" means being outside the range starting at the lowest
3135 possible value and ending at 10, in other words, being greater than 10.
3136 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3139 We set up things so that the missing bounds are handled in a consistent
3140 manner so neither a missing bound nor "true" and "false" need to be
3141 handled using a special case. */
3143 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3144 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3145 and UPPER1_P are nonzero if the respective argument is an upper bound
3146 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3147 must be specified for a comparison. ARG1 will be converted to ARG0's
3148 type if both are specified. */
3151 range_binop (code, type, arg0, upper0_p, arg1, upper1_p)
3152 enum tree_code code;
3155 int upper0_p, upper1_p;
3161 /* If neither arg represents infinity, do the normal operation.
3162 Else, if not a comparison, return infinity. Else handle the special
3163 comparison rules. Note that most of the cases below won't occur, but
3164 are handled for consistency. */
3166 if (arg0 != 0 && arg1 != 0)
3168 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
3169 arg0, convert (TREE_TYPE (arg0), arg1)));
3171 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3174 if (TREE_CODE_CLASS (code) != '<')
3177 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3178 for neither. In real maths, we cannot assume open ended ranges are
3179 the same. But, this is computer arithmetic, where numbers are finite.
3180 We can therefore make the transformation of any unbounded range with
3181 the value Z, Z being greater than any representable number. This permits
3182 us to treat unbounded ranges as equal. */
3183 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3184 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3188 result = sgn0 == sgn1;
3191 result = sgn0 != sgn1;
3194 result = sgn0 < sgn1;
3197 result = sgn0 <= sgn1;
3200 result = sgn0 > sgn1;
3203 result = sgn0 >= sgn1;
3209 return convert (type, result ? integer_one_node : integer_zero_node);
3212 /* Given EXP, a logical expression, set the range it is testing into
3213 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3214 actually being tested. *PLOW and *PHIGH will have be made the same type
3215 as the returned expression. If EXP is not a comparison, we will most
3216 likely not be returning a useful value and range. */
3219 make_range (exp, pin_p, plow, phigh)
3224 enum tree_code code;
3225 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
3226 tree orig_type = NULL_TREE;
3228 tree low, high, n_low, n_high;
3230 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3231 and see if we can refine the range. Some of the cases below may not
3232 happen, but it doesn't seem worth worrying about this. We "continue"
3233 the outer loop when we've changed something; otherwise we "break"
3234 the switch, which will "break" the while. */
3236 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
3240 code = TREE_CODE (exp);
3242 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3244 arg0 = TREE_OPERAND (exp, 0);
3245 if (TREE_CODE_CLASS (code) == '<'
3246 || TREE_CODE_CLASS (code) == '1'
3247 || TREE_CODE_CLASS (code) == '2')
3248 type = TREE_TYPE (arg0);
3249 if (TREE_CODE_CLASS (code) == '2'
3250 || TREE_CODE_CLASS (code) == '<'
3251 || (TREE_CODE_CLASS (code) == 'e'
3252 && tree_code_length[(int) code] > 1))
3253 arg1 = TREE_OPERAND (exp, 1);
3256 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3257 lose a cast by accident. */
3258 if (type != NULL_TREE && orig_type == NULL_TREE)
3263 case TRUTH_NOT_EXPR:
3264 in_p = ! in_p, exp = arg0;
3267 case EQ_EXPR: case NE_EXPR:
3268 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3269 /* We can only do something if the range is testing for zero
3270 and if the second operand is an integer constant. Note that
3271 saying something is "in" the range we make is done by
3272 complementing IN_P since it will set in the initial case of
3273 being not equal to zero; "out" is leaving it alone. */
3274 if (low == 0 || high == 0
3275 || ! integer_zerop (low) || ! integer_zerop (high)
3276 || TREE_CODE (arg1) != INTEGER_CST)
3281 case NE_EXPR: /* - [c, c] */
3284 case EQ_EXPR: /* + [c, c] */
3285 in_p = ! in_p, low = high = arg1;
3287 case GT_EXPR: /* - [-, c] */
3288 low = 0, high = arg1;
3290 case GE_EXPR: /* + [c, -] */
3291 in_p = ! in_p, low = arg1, high = 0;
3293 case LT_EXPR: /* - [c, -] */
3294 low = arg1, high = 0;
3296 case LE_EXPR: /* + [-, c] */
3297 in_p = ! in_p, low = 0, high = arg1;
3305 /* If this is an unsigned comparison, we also know that EXP is
3306 greater than or equal to zero. We base the range tests we make
3307 on that fact, so we record it here so we can parse existing
3309 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3311 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3312 1, convert (type, integer_zero_node),
3316 in_p = n_in_p, low = n_low, high = n_high;
3318 /* If the high bound is missing, but we
3319 have a low bound, reverse the range so
3320 it goes from zero to the low bound minus 1. */
3321 if (high == 0 && low)
3324 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3325 integer_one_node, 0);
3326 low = convert (type, integer_zero_node);
3332 /* (-x) IN [a,b] -> x in [-b, -a] */
3333 n_low = range_binop (MINUS_EXPR, type,
3334 convert (type, integer_zero_node), 0, high, 1);
3335 n_high = range_binop (MINUS_EXPR, type,
3336 convert (type, integer_zero_node), 0, low, 0);
3337 low = n_low, high = n_high;
3343 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3344 convert (type, integer_one_node));
3347 case PLUS_EXPR: case MINUS_EXPR:
3348 if (TREE_CODE (arg1) != INTEGER_CST)
3351 /* If EXP is signed, any overflow in the computation is undefined,
3352 so we don't worry about it so long as our computations on
3353 the bounds don't overflow. For unsigned, overflow is defined
3354 and this is exactly the right thing. */
3355 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3356 type, low, 0, arg1, 0);
3357 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3358 type, high, 1, arg1, 0);
3359 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3360 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3363 /* Check for an unsigned range which has wrapped around the maximum
3364 value thus making n_high < n_low, and normalize it. */
3365 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3367 low = range_binop (PLUS_EXPR, type, n_high, 0,
3368 integer_one_node, 0);
3369 high = range_binop (MINUS_EXPR, type, n_low, 0,
3370 integer_one_node, 0);
3374 low = n_low, high = n_high;
3379 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3380 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3383 if (! INTEGRAL_TYPE_P (type)
3384 || (low != 0 && ! int_fits_type_p (low, type))
3385 || (high != 0 && ! int_fits_type_p (high, type)))
3388 n_low = low, n_high = high;
3391 n_low = convert (type, n_low);
3394 n_high = convert (type, n_high);
3396 /* If we're converting from an unsigned to a signed type,
3397 we will be doing the comparison as unsigned. The tests above
3398 have already verified that LOW and HIGH are both positive.
3400 So we have to make sure that the original unsigned value will
3401 be interpreted as positive. */
3402 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3404 tree equiv_type = type_for_mode (TYPE_MODE (type), 1);
3407 /* A range without an upper bound is, naturally, unbounded.
3408 Since convert would have cropped a very large value, use
3409 the max value for the destination type. */
3411 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3412 : TYPE_MAX_VALUE (type);
3414 high_positive = fold (build (RSHIFT_EXPR, type,
3415 convert (type, high_positive),
3416 convert (type, integer_one_node)));
3418 /* If the low bound is specified, "and" the range with the
3419 range for which the original unsigned value will be
3423 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3425 1, convert (type, integer_zero_node),
3429 in_p = (n_in_p == in_p);
3433 /* Otherwise, "or" the range with the range of the input
3434 that will be interpreted as negative. */
3435 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3437 1, convert (type, integer_zero_node),
3441 in_p = (in_p != n_in_p);
3446 low = n_low, high = n_high;
3456 /* If EXP is a constant, we can evaluate whether this is true or false. */
3457 if (TREE_CODE (exp) == INTEGER_CST)
3459 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3461 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3467 *pin_p = in_p, *plow = low, *phigh = high;
3471 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3472 type, TYPE, return an expression to test if EXP is in (or out of, depending
3473 on IN_P) the range. */
3476 build_range_check (type, exp, in_p, low, high)
3482 tree etype = TREE_TYPE (exp);
3486 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3487 return invert_truthvalue (value);
3489 else if (low == 0 && high == 0)
3490 return convert (type, integer_one_node);
3493 return fold (build (LE_EXPR, type, exp, high));
3496 return fold (build (GE_EXPR, type, exp, low));
3498 else if (operand_equal_p (low, high, 0))
3499 return fold (build (EQ_EXPR, type, exp, low));
3501 else if (TREE_UNSIGNED (etype) && integer_zerop (low))
3502 return build_range_check (type, exp, 1, 0, high);
3504 else if (integer_zerop (low))
3506 utype = unsigned_type (etype);
3507 return build_range_check (type, convert (utype, exp), 1, 0,
3508 convert (utype, high));
3511 else if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3512 && ! TREE_OVERFLOW (value))
3513 return build_range_check (type,
3514 fold (build (MINUS_EXPR, etype, exp, low)),
3515 1, convert (etype, integer_zero_node), value);
3520 /* Given two ranges, see if we can merge them into one. Return 1 if we
3521 can, 0 if we can't. Set the output range into the specified parameters. */
3524 merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
3528 tree low0, high0, low1, high1;
3536 int lowequal = ((low0 == 0 && low1 == 0)
3537 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3538 low0, 0, low1, 0)));
3539 int highequal = ((high0 == 0 && high1 == 0)
3540 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3541 high0, 1, high1, 1)));
3543 /* Make range 0 be the range that starts first, or ends last if they
3544 start at the same value. Swap them if it isn't. */
3545 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3548 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3549 high1, 1, high0, 1))))
3551 temp = in0_p, in0_p = in1_p, in1_p = temp;
3552 tem = low0, low0 = low1, low1 = tem;
3553 tem = high0, high0 = high1, high1 = tem;
3556 /* Now flag two cases, whether the ranges are disjoint or whether the
3557 second range is totally subsumed in the first. Note that the tests
3558 below are simplified by the ones above. */
3559 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3560 high0, 1, low1, 0));
3561 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3562 high1, 1, high0, 1));
3564 /* We now have four cases, depending on whether we are including or
3565 excluding the two ranges. */
3568 /* If they don't overlap, the result is false. If the second range
3569 is a subset it is the result. Otherwise, the range is from the start
3570 of the second to the end of the first. */
3572 in_p = 0, low = high = 0;
3574 in_p = 1, low = low1, high = high1;
3576 in_p = 1, low = low1, high = high0;
3579 else if (in0_p && ! in1_p)
3581 /* If they don't overlap, the result is the first range. If they are
3582 equal, the result is false. If the second range is a subset of the
3583 first, and the ranges begin at the same place, we go from just after
3584 the end of the first range to the end of the second. If the second
3585 range is not a subset of the first, or if it is a subset and both
3586 ranges end at the same place, the range starts at the start of the
3587 first range and ends just before the second range.
3588 Otherwise, we can't describe this as a single range. */
3590 in_p = 1, low = low0, high = high0;
3591 else if (lowequal && highequal)
3592 in_p = 0, low = high = 0;
3593 else if (subset && lowequal)
3595 in_p = 1, high = high0;
3596 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3597 integer_one_node, 0);
3599 else if (! subset || highequal)
3601 in_p = 1, low = low0;
3602 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3603 integer_one_node, 0);
3609 else if (! in0_p && in1_p)
3611 /* If they don't overlap, the result is the second range. If the second
3612 is a subset of the first, the result is false. Otherwise,
3613 the range starts just after the first range and ends at the
3614 end of the second. */
3616 in_p = 1, low = low1, high = high1;
3617 else if (subset || highequal)
3618 in_p = 0, low = high = 0;
3621 in_p = 1, high = high1;
3622 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3623 integer_one_node, 0);
3629 /* The case where we are excluding both ranges. Here the complex case
3630 is if they don't overlap. In that case, the only time we have a
3631 range is if they are adjacent. If the second is a subset of the
3632 first, the result is the first. Otherwise, the range to exclude
3633 starts at the beginning of the first range and ends at the end of the
3637 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3638 range_binop (PLUS_EXPR, NULL_TREE,
3640 integer_one_node, 1),
3642 in_p = 0, low = low0, high = high1;
3647 in_p = 0, low = low0, high = high0;
3649 in_p = 0, low = low0, high = high1;
3652 *pin_p = in_p, *plow = low, *phigh = high;
3656 /* EXP is some logical combination of boolean tests. See if we can
3657 merge it into some range test. Return the new tree if so. */
3660 fold_range_test (exp)
3663 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3664 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3665 int in0_p, in1_p, in_p;
3666 tree low0, low1, low, high0, high1, high;
3667 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3668 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3671 /* If this is an OR operation, invert both sides; we will invert
3672 again at the end. */
3674 in0_p = ! in0_p, in1_p = ! in1_p;
3676 /* If both expressions are the same, if we can merge the ranges, and we
3677 can build the range test, return it or it inverted. If one of the
3678 ranges is always true or always false, consider it to be the same
3679 expression as the other. */
3680 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3681 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3683 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3685 : rhs != 0 ? rhs : integer_zero_node,
3687 return or_op ? invert_truthvalue (tem) : tem;
3689 /* On machines where the branch cost is expensive, if this is a
3690 short-circuited branch and the underlying object on both sides
3691 is the same, make a non-short-circuit operation. */
3692 else if (BRANCH_COST >= 2
3693 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3694 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3695 && operand_equal_p (lhs, rhs, 0))
3697 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3698 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3699 which cases we can't do this. */
3700 if (simple_operand_p (lhs))
3701 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3702 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3703 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3704 TREE_OPERAND (exp, 1));
3706 else if (global_bindings_p () == 0
3707 && ! contains_placeholder_p (lhs))
3709 tree common = save_expr (lhs);
3711 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3712 or_op ? ! in0_p : in0_p,
3714 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3715 or_op ? ! in1_p : in1_p,
3717 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3718 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3719 TREE_TYPE (exp), lhs, rhs);
3726 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3727 bit value. Arrange things so the extra bits will be set to zero if and
3728 only if C is signed-extended to its full width. If MASK is nonzero,
3729 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3732 unextend (c, p, unsignedp, mask)
3738 tree type = TREE_TYPE (c);
3739 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3742 if (p == modesize || unsignedp)
3745 /* We work by getting just the sign bit into the low-order bit, then
3746 into the high-order bit, then sign-extend. We then XOR that value
3748 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3749 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3751 /* We must use a signed type in order to get an arithmetic right shift.
3752 However, we must also avoid introducing accidental overflows, so that
3753 a subsequent call to integer_zerop will work. Hence we must
3754 do the type conversion here. At this point, the constant is either
3755 zero or one, and the conversion to a signed type can never overflow.
3756 We could get an overflow if this conversion is done anywhere else. */
3757 if (TREE_UNSIGNED (type))
3758 temp = convert (signed_type (type), temp);
3760 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3761 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3763 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3764 /* If necessary, convert the type back to match the type of C. */
3765 if (TREE_UNSIGNED (type))
3766 temp = convert (type, temp);
3768 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3771 /* Find ways of folding logical expressions of LHS and RHS:
3772 Try to merge two comparisons to the same innermost item.
3773 Look for range tests like "ch >= '0' && ch <= '9'".
3774 Look for combinations of simple terms on machines with expensive branches
3775 and evaluate the RHS unconditionally.
3777 For example, if we have p->a == 2 && p->b == 4 and we can make an
3778 object large enough to span both A and B, we can do this with a comparison
3779 against the object ANDed with the a mask.
3781 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3782 operations to do this with one comparison.
3784 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3785 function and the one above.
3787 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3788 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3790 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3793 We return the simplified tree or 0 if no optimization is possible. */
3796 fold_truthop (code, truth_type, lhs, rhs)
3797 enum tree_code code;
3798 tree truth_type, lhs, rhs;
3800 /* If this is the "or" of two comparisons, we can do something if we
3801 the comparisons are NE_EXPR. If this is the "and", we can do something
3802 if the comparisons are EQ_EXPR. I.e.,
3803 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3805 WANTED_CODE is this operation code. For single bit fields, we can
3806 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3807 comparison for one-bit fields. */
3809 enum tree_code wanted_code;
3810 enum tree_code lcode, rcode;
3811 tree ll_arg, lr_arg, rl_arg, rr_arg;
3812 tree ll_inner, lr_inner, rl_inner, rr_inner;
3813 int ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3814 int rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3815 int xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3816 int lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3817 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3818 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3819 enum machine_mode lnmode, rnmode;
3820 tree ll_mask, lr_mask, rl_mask, rr_mask;
3821 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3822 tree l_const, r_const;
3823 tree lntype, rntype, result;
3824 int first_bit, end_bit;
3827 /* Start by getting the comparison codes. Fail if anything is volatile.
3828 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3829 it were surrounded with a NE_EXPR. */
3831 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3834 lcode = TREE_CODE (lhs);
3835 rcode = TREE_CODE (rhs);
3837 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3838 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3840 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3841 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3843 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3846 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3847 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3849 ll_arg = TREE_OPERAND (lhs, 0);
3850 lr_arg = TREE_OPERAND (lhs, 1);
3851 rl_arg = TREE_OPERAND (rhs, 0);
3852 rr_arg = TREE_OPERAND (rhs, 1);
3854 /* If the RHS can be evaluated unconditionally and its operands are
3855 simple, it wins to evaluate the RHS unconditionally on machines
3856 with expensive branches. In this case, this isn't a comparison
3857 that can be merged. Avoid doing this if the RHS is a floating-point
3858 comparison since those can trap. */
3860 if (BRANCH_COST >= 2
3861 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
3862 && simple_operand_p (rl_arg)
3863 && simple_operand_p (rr_arg))
3864 return build (code, truth_type, lhs, rhs);
3866 /* See if the comparisons can be merged. Then get all the parameters for
3869 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3870 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3874 ll_inner = decode_field_reference (ll_arg,
3875 &ll_bitsize, &ll_bitpos, &ll_mode,
3876 &ll_unsignedp, &volatilep, &ll_mask,
3878 lr_inner = decode_field_reference (lr_arg,
3879 &lr_bitsize, &lr_bitpos, &lr_mode,
3880 &lr_unsignedp, &volatilep, &lr_mask,
3882 rl_inner = decode_field_reference (rl_arg,
3883 &rl_bitsize, &rl_bitpos, &rl_mode,
3884 &rl_unsignedp, &volatilep, &rl_mask,
3886 rr_inner = decode_field_reference (rr_arg,
3887 &rr_bitsize, &rr_bitpos, &rr_mode,
3888 &rr_unsignedp, &volatilep, &rr_mask,
3891 /* It must be true that the inner operation on the lhs of each
3892 comparison must be the same if we are to be able to do anything.
3893 Then see if we have constants. If not, the same must be true for
3895 if (volatilep || ll_inner == 0 || rl_inner == 0
3896 || ! operand_equal_p (ll_inner, rl_inner, 0))
3899 if (TREE_CODE (lr_arg) == INTEGER_CST
3900 && TREE_CODE (rr_arg) == INTEGER_CST)
3901 l_const = lr_arg, r_const = rr_arg;
3902 else if (lr_inner == 0 || rr_inner == 0
3903 || ! operand_equal_p (lr_inner, rr_inner, 0))
3906 l_const = r_const = 0;
3908 /* If either comparison code is not correct for our logical operation,
3909 fail. However, we can convert a one-bit comparison against zero into
3910 the opposite comparison against that bit being set in the field. */
3912 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
3913 if (lcode != wanted_code)
3915 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
3917 /* Make the left operand unsigned, since we are only interested
3918 in the value of one bit. Otherwise we are doing the wrong
3927 /* This is analogous to the code for l_const above. */
3928 if (rcode != wanted_code)
3930 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
3939 /* See if we can find a mode that contains both fields being compared on
3940 the left. If we can't, fail. Otherwise, update all constants and masks
3941 to be relative to a field of that size. */
3942 first_bit = MIN (ll_bitpos, rl_bitpos);
3943 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
3944 lnmode = get_best_mode (end_bit - first_bit, first_bit,
3945 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
3947 if (lnmode == VOIDmode)
3950 lnbitsize = GET_MODE_BITSIZE (lnmode);
3951 lnbitpos = first_bit & ~ (lnbitsize - 1);
3952 lntype = type_for_size (lnbitsize, 1);
3953 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
3955 if (BYTES_BIG_ENDIAN)
3957 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
3958 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
3961 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
3962 size_int (xll_bitpos), 0);
3963 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
3964 size_int (xrl_bitpos), 0);
3968 l_const = convert (lntype, l_const);
3969 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
3970 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
3971 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
3972 fold (build1 (BIT_NOT_EXPR,
3976 warning ("comparison is always %d", wanted_code == NE_EXPR);
3978 return convert (truth_type,
3979 wanted_code == NE_EXPR
3980 ? integer_one_node : integer_zero_node);
3985 r_const = convert (lntype, r_const);
3986 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
3987 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
3988 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
3989 fold (build1 (BIT_NOT_EXPR,
3993 warning ("comparison is always %d", wanted_code == NE_EXPR);
3995 return convert (truth_type,
3996 wanted_code == NE_EXPR
3997 ? integer_one_node : integer_zero_node);
4001 /* If the right sides are not constant, do the same for it. Also,
4002 disallow this optimization if a size or signedness mismatch occurs
4003 between the left and right sides. */
4006 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4007 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4008 /* Make sure the two fields on the right
4009 correspond to the left without being swapped. */
4010 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4013 first_bit = MIN (lr_bitpos, rr_bitpos);
4014 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4015 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4016 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4018 if (rnmode == VOIDmode)
4021 rnbitsize = GET_MODE_BITSIZE (rnmode);
4022 rnbitpos = first_bit & ~ (rnbitsize - 1);
4023 rntype = type_for_size (rnbitsize, 1);
4024 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4026 if (BYTES_BIG_ENDIAN)
4028 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4029 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4032 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
4033 size_int (xlr_bitpos), 0);
4034 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
4035 size_int (xrr_bitpos), 0);
4037 /* Make a mask that corresponds to both fields being compared.
4038 Do this for both items being compared. If the operands are the
4039 same size and the bits being compared are in the same position
4040 then we can do this by masking both and comparing the masked
4042 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4043 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4044 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4046 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4047 ll_unsignedp || rl_unsignedp);
4048 if (! all_ones_mask_p (ll_mask, lnbitsize))
4049 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
4051 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4052 lr_unsignedp || rr_unsignedp);
4053 if (! all_ones_mask_p (lr_mask, rnbitsize))
4054 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
4056 return build (wanted_code, truth_type, lhs, rhs);
4059 /* There is still another way we can do something: If both pairs of
4060 fields being compared are adjacent, we may be able to make a wider
4061 field containing them both.
4063 Note that we still must mask the lhs/rhs expressions. Furthermore,
4064 the mask must be shifted to account for the shift done by
4065 make_bit_field_ref. */
4066 if ((ll_bitsize + ll_bitpos == rl_bitpos
4067 && lr_bitsize + lr_bitpos == rr_bitpos)
4068 || (ll_bitpos == rl_bitpos + rl_bitsize
4069 && lr_bitpos == rr_bitpos + rr_bitsize))
4073 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4074 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4075 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4076 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4078 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4079 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4080 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4081 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4083 /* Convert to the smaller type before masking out unwanted bits. */
4085 if (lntype != rntype)
4087 if (lnbitsize > rnbitsize)
4089 lhs = convert (rntype, lhs);
4090 ll_mask = convert (rntype, ll_mask);
4093 else if (lnbitsize < rnbitsize)
4095 rhs = convert (lntype, rhs);
4096 lr_mask = convert (lntype, lr_mask);
4101 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4102 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
4104 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4105 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
4107 return build (wanted_code, truth_type, lhs, rhs);
4113 /* Handle the case of comparisons with constants. If there is something in
4114 common between the masks, those bits of the constants must be the same.
4115 If not, the condition is always false. Test for this to avoid generating
4116 incorrect code below. */
4117 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4118 if (! integer_zerop (result)
4119 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4120 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4122 if (wanted_code == NE_EXPR)
4124 warning ("`or' of unmatched not-equal tests is always 1");
4125 return convert (truth_type, integer_one_node);
4129 warning ("`and' of mutually exclusive equal-tests is always 0");
4130 return convert (truth_type, integer_zero_node);
4134 /* Construct the expression we will return. First get the component
4135 reference we will make. Unless the mask is all ones the width of
4136 that field, perform the mask operation. Then compare with the
4138 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4139 ll_unsignedp || rl_unsignedp);
4141 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4142 if (! all_ones_mask_p (ll_mask, lnbitsize))
4143 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
4145 return build (wanted_code, truth_type, result,
4146 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4149 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4153 optimize_minmax_comparison (t)
4156 tree type = TREE_TYPE (t);
4157 tree arg0 = TREE_OPERAND (t, 0);
4158 enum tree_code op_code;
4159 tree comp_const = TREE_OPERAND (t, 1);
4161 int consts_equal, consts_lt;
4164 STRIP_SIGN_NOPS (arg0);
4166 op_code = TREE_CODE (arg0);
4167 minmax_const = TREE_OPERAND (arg0, 1);
4168 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4169 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4170 inner = TREE_OPERAND (arg0, 0);
4172 /* If something does not permit us to optimize, return the original tree. */
4173 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4174 || TREE_CODE (comp_const) != INTEGER_CST
4175 || TREE_CONSTANT_OVERFLOW (comp_const)
4176 || TREE_CODE (minmax_const) != INTEGER_CST
4177 || TREE_CONSTANT_OVERFLOW (minmax_const))
4180 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4181 and GT_EXPR, doing the rest with recursive calls using logical
4183 switch (TREE_CODE (t))
4185 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4187 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4191 fold (build (TRUTH_ORIF_EXPR, type,
4192 optimize_minmax_comparison
4193 (build (EQ_EXPR, type, arg0, comp_const)),
4194 optimize_minmax_comparison
4195 (build (GT_EXPR, type, arg0, comp_const))));
4198 if (op_code == MAX_EXPR && consts_equal)
4199 /* MAX (X, 0) == 0 -> X <= 0 */
4200 return fold (build (LE_EXPR, type, inner, comp_const));
4202 else if (op_code == MAX_EXPR && consts_lt)
4203 /* MAX (X, 0) == 5 -> X == 5 */
4204 return fold (build (EQ_EXPR, type, inner, comp_const));
4206 else if (op_code == MAX_EXPR)
4207 /* MAX (X, 0) == -1 -> false */
4208 return omit_one_operand (type, integer_zero_node, inner);
4210 else if (consts_equal)
4211 /* MIN (X, 0) == 0 -> X >= 0 */
4212 return fold (build (GE_EXPR, type, inner, comp_const));
4215 /* MIN (X, 0) == 5 -> false */
4216 return omit_one_operand (type, integer_zero_node, inner);
4219 /* MIN (X, 0) == -1 -> X == -1 */
4220 return fold (build (EQ_EXPR, type, inner, comp_const));
4223 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4224 /* MAX (X, 0) > 0 -> X > 0
4225 MAX (X, 0) > 5 -> X > 5 */
4226 return fold (build (GT_EXPR, type, inner, comp_const));
4228 else if (op_code == MAX_EXPR)
4229 /* MAX (X, 0) > -1 -> true */
4230 return omit_one_operand (type, integer_one_node, inner);
4232 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4233 /* MIN (X, 0) > 0 -> false
4234 MIN (X, 0) > 5 -> false */
4235 return omit_one_operand (type, integer_zero_node, inner);
4238 /* MIN (X, 0) > -1 -> X > -1 */
4239 return fold (build (GT_EXPR, type, inner, comp_const));
4246 /* T is an integer expression that is being multiplied, divided, or taken a
4247 modulus (CODE says which and what kind of divide or modulus) by a
4248 constant C. See if we can eliminate that operation by folding it with
4249 other operations already in T. WIDE_TYPE, if non-null, is a type that
4250 should be used for the computation if wider than our type.
4252 For example, if we are dividing (X * 8) + (Y + 16) by 4, we can return
4253 (X * 2) + (Y + 4). We also canonicalize (X + 7) * 4 into X * 4 + 28
4254 in the hope that either the machine has a multiply-accumulate insn
4255 or that this is part of an addressing calculation.
4257 If we return a non-null expression, it is an equivalent form of the
4258 original computation, but need not be in the original type. */
4261 extract_muldiv (t, c, code, wide_type)
4264 enum tree_code code;
4267 tree type = TREE_TYPE (t);
4268 enum tree_code tcode = TREE_CODE (t);
4269 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4270 > GET_MODE_SIZE (TYPE_MODE (type)))
4271 ? wide_type : type);
4273 int same_p = tcode == code;
4274 tree op0 = NULL_TREE, op1 = NULL_TREE;
4276 /* Don't deal with constants of zero here; they confuse the code below. */
4277 if (integer_zerop (c))
4280 if (TREE_CODE_CLASS (tcode) == '1')
4281 op0 = TREE_OPERAND (t, 0);
4283 if (TREE_CODE_CLASS (tcode) == '2')
4284 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4286 /* Note that we need not handle conditional operations here since fold
4287 already handles those cases. So just do arithmetic here. */
4291 /* For a constant, we can always simplify if we are a multiply
4292 or (for divide and modulus) if it is a multiple of our constant. */
4293 if (code == MULT_EXPR
4294 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4295 return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
4298 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4300 /* Pass the constant down and see if we can make a simplification. If
4301 we can, replace this expression with the inner simplification for
4302 possible later conversion to our or some other type. */
4303 if (0 != (t1 = extract_muldiv (op0, convert (TREE_TYPE (op0), c), code,
4304 code == MULT_EXPR ? ctype : NULL_TREE)))
4308 case NEGATE_EXPR: case ABS_EXPR:
4309 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4310 return fold (build1 (tcode, ctype, convert (ctype, t1)));
4313 case MIN_EXPR: case MAX_EXPR:
4314 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4315 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4316 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4318 if (tree_int_cst_sgn (c) < 0)
4319 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4321 return fold (build (tcode, ctype, convert (ctype, t1),
4322 convert (ctype, t2)));
4326 case WITH_RECORD_EXPR:
4327 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4328 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4329 TREE_OPERAND (t, 1));
4333 /* If this has not been evaluated and the operand has no side effects,
4334 we can see if we can do something inside it and make a new one.
4335 Note that this test is overly conservative since we can do this
4336 if the only reason it had side effects is that it was another
4337 similar SAVE_EXPR, but that isn't worth bothering with. */
4338 if (SAVE_EXPR_RTL (t) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
4339 && 0 != (t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code,
4341 return save_expr (t1);
4344 case LSHIFT_EXPR: case RSHIFT_EXPR:
4345 /* If the second operand is constant, this is a multiplication
4346 or floor division, by a power of two, so we can treat it that
4347 way unless the multiplier or divisor overflows. */
4348 if (TREE_CODE (op1) == INTEGER_CST
4349 && 0 != (t1 = convert (ctype,
4350 const_binop (LSHIFT_EXPR, size_one_node,
4352 && ! TREE_OVERFLOW (t1))
4353 return extract_muldiv (build (tcode == LSHIFT_EXPR
4354 ? MULT_EXPR : FLOOR_DIV_EXPR,
4355 ctype, convert (ctype, op0), t1),
4356 c, code, wide_type);
4359 case PLUS_EXPR: case MINUS_EXPR:
4360 /* See if we can eliminate the operation on both sides. If we can, we
4361 can return a new PLUS or MINUS. If we can't, the only remaining
4362 cases where we can do anything are if the second operand is a
4364 t1 = extract_muldiv (op0, c, code, wide_type);
4365 t2 = extract_muldiv (op1, c, code, wide_type);
4366 if (t1 != 0 && t2 != 0)
4367 return fold (build (tcode, ctype, convert (ctype, t1),
4368 convert (ctype, t2)));
4370 /* If this was a subtraction, negate OP1 and set it to be an addition.
4371 This simplifies the logic below. */
4372 if (tcode == MINUS_EXPR)
4373 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4375 if (TREE_CODE (op1) != INTEGER_CST)
4378 /* If either OP1 or C are negative, this optimization is not safe for
4379 some of the division and remainder types while for others we need
4380 to change the code. */
4381 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4383 if (code == CEIL_DIV_EXPR)
4384 code = FLOOR_DIV_EXPR;
4385 else if (code == CEIL_MOD_EXPR)
4386 code = FLOOR_MOD_EXPR;
4387 else if (code == FLOOR_DIV_EXPR)
4388 code = CEIL_DIV_EXPR;
4389 else if (code == FLOOR_MOD_EXPR)
4390 code = CEIL_MOD_EXPR;
4391 else if (code != MULT_EXPR)
4395 /* Now do the operation and verify it doesn't overflow. */
4396 op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
4397 if (op1 == 0 || TREE_OVERFLOW (op1))
4400 /* If we were able to eliminate our operation from the first side,
4401 apply our operation to the second side and reform the PLUS. */
4402 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4403 return fold (build (tcode, ctype, convert (ctype, t1), op1));
4405 /* The last case is if we are a multiply. In that case, we can
4406 apply the distributive law to commute the multiply and addition
4407 if the multiplication of the constants doesn't overflow. */
4408 if (code == MULT_EXPR)
4409 return fold (build (tcode, ctype, fold (build (code, ctype,
4410 convert (ctype, op0),
4411 convert (ctype, c))),
4417 /* We have a special case here if we are doing something like
4418 (C * 8) % 4 since we know that's zero. */
4419 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4420 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4421 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4422 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4423 return omit_one_operand (type, integer_zero_node, op0);
4425 /* ... fall through ... */
4427 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4428 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4429 /* If we can extract our operation from the LHS, do so and return a
4430 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4431 do something only if the second operand is a constant. */
4433 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4434 return fold (build (tcode, ctype, convert (ctype, t1),
4435 convert (ctype, op1)));
4436 else if (tcode == MULT_EXPR && code == MULT_EXPR
4437 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4438 return fold (build (tcode, ctype, convert (ctype, op0),
4439 convert (ctype, t1)));
4440 else if (TREE_CODE (op1) != INTEGER_CST)
4443 /* If these are the same operation types, we can associate them
4444 assuming no overflow. */
4446 && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
4447 convert (ctype, c), 0))
4448 && ! TREE_OVERFLOW (t1))
4449 return fold (build (tcode, ctype, convert (ctype, op0), t1));
4451 /* If these operations "cancel" each other, we have the main
4452 optimizations of this pass, which occur when either constant is a
4453 multiple of the other, in which case we replace this with either an
4454 operation or CODE or TCODE. */
4455 if ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4456 || (tcode == MULT_EXPR
4457 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4458 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR))
4460 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4461 return fold (build (tcode, ctype, convert (ctype, op0),
4463 const_binop (TRUNC_DIV_EXPR,
4465 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4466 return fold (build (code, ctype, convert (ctype, op0),
4468 const_binop (TRUNC_DIV_EXPR,
4480 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4481 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4482 that we may sometimes modify the tree. */
4485 strip_compound_expr (t, s)
4489 enum tree_code code = TREE_CODE (t);
4491 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4492 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4493 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4494 return TREE_OPERAND (t, 1);
4496 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4497 don't bother handling any other types. */
4498 else if (code == COND_EXPR)
4500 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4501 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4502 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4504 else if (TREE_CODE_CLASS (code) == '1')
4505 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4506 else if (TREE_CODE_CLASS (code) == '<'
4507 || TREE_CODE_CLASS (code) == '2')
4509 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4510 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4516 /* Return a node which has the indicated constant VALUE (either 0 or
4517 1), and is of the indicated TYPE. */
4520 constant_boolean_node (value, type)
4524 if (type == integer_type_node)
4525 return value ? integer_one_node : integer_zero_node;
4526 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4527 return truthvalue_conversion (value ? integer_one_node :
4531 tree t = build_int_2 (value, 0);
4533 TREE_TYPE (t) = type;
4538 /* Utility function for the following routine, to see how complex a nesting of
4539 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4540 we don't care (to avoid spending too much time on complex expressions.). */
4543 count_cond (expr, lim)
4549 if (TREE_CODE (expr) != COND_EXPR)
4554 true = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4555 false = count_cond (TREE_OPERAND (expr, 2), lim - 1 - true);
4556 return MIN (lim, 1 + true + false);
4559 /* Perform constant folding and related simplification of EXPR.
4560 The related simplifications include x*1 => x, x*0 => 0, etc.,
4561 and application of the associative law.
4562 NOP_EXPR conversions may be removed freely (as long as we
4563 are careful not to change the C type of the overall expression)
4564 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4565 but we can constant-fold them if they have constant operands. */
4571 register tree t = expr;
4572 tree t1 = NULL_TREE;
4574 tree type = TREE_TYPE (expr);
4575 register tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4576 register enum tree_code code = TREE_CODE (t);
4579 /* WINS will be nonzero when the switch is done
4580 if all operands are constant. */
4583 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4584 Likewise for a SAVE_EXPR that's already been evaluated. */
4585 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t)) != 0)
4588 /* Return right away if already constant. */
4589 if (TREE_CONSTANT (t))
4591 if (code == CONST_DECL)
4592 return DECL_INITIAL (t);
4596 #ifdef MAX_INTEGER_COMPUTATION_MODE
4597 check_max_integer_computation_mode (expr);
4600 kind = TREE_CODE_CLASS (code);
4601 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4605 /* Special case for conversion ops that can have fixed point args. */
4606 arg0 = TREE_OPERAND (t, 0);
4608 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4610 STRIP_SIGN_NOPS (arg0);
4612 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4613 subop = TREE_REALPART (arg0);
4617 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4618 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4619 && TREE_CODE (subop) != REAL_CST
4620 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4622 /* Note that TREE_CONSTANT isn't enough:
4623 static var addresses are constant but we can't
4624 do arithmetic on them. */
4627 else if (kind == 'e' || kind == '<'
4628 || kind == '1' || kind == '2' || kind == 'r')
4630 register int len = tree_code_length[(int) code];
4632 for (i = 0; i < len; i++)
4634 tree op = TREE_OPERAND (t, i);
4638 continue; /* Valid for CALL_EXPR, at least. */
4640 if (kind == '<' || code == RSHIFT_EXPR)
4642 /* Signedness matters here. Perhaps we can refine this
4644 STRIP_SIGN_NOPS (op);
4648 /* Strip any conversions that don't change the mode. */
4652 if (TREE_CODE (op) == COMPLEX_CST)
4653 subop = TREE_REALPART (op);
4657 if (TREE_CODE (subop) != INTEGER_CST
4658 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4659 && TREE_CODE (subop) != REAL_CST
4660 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4662 /* Note that TREE_CONSTANT isn't enough:
4663 static var addresses are constant but we can't
4664 do arithmetic on them. */
4674 /* If this is a commutative operation, and ARG0 is a constant, move it
4675 to ARG1 to reduce the number of tests below. */
4676 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
4677 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
4678 || code == BIT_AND_EXPR)
4679 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
4681 tem = arg0; arg0 = arg1; arg1 = tem;
4683 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
4684 TREE_OPERAND (t, 1) = tem;
4687 /* Now WINS is set as described above,
4688 ARG0 is the first operand of EXPR,
4689 and ARG1 is the second operand (if it has more than one operand).
4691 First check for cases where an arithmetic operation is applied to a
4692 compound, conditional, or comparison operation. Push the arithmetic
4693 operation inside the compound or conditional to see if any folding
4694 can then be done. Convert comparison to conditional for this purpose.
4695 The also optimizes non-constant cases that used to be done in
4698 Before we do that, see if this is a BIT_AND_EXPR or a BIT_OR_EXPR,
4699 one of the operands is a comparison and the other is a comparison, a
4700 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
4701 code below would make the expression more complex. Change it to a
4702 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
4703 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
4705 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
4706 || code == EQ_EXPR || code == NE_EXPR)
4707 && ((truth_value_p (TREE_CODE (arg0))
4708 && (truth_value_p (TREE_CODE (arg1))
4709 || (TREE_CODE (arg1) == BIT_AND_EXPR
4710 && integer_onep (TREE_OPERAND (arg1, 1)))))
4711 || (truth_value_p (TREE_CODE (arg1))
4712 && (truth_value_p (TREE_CODE (arg0))
4713 || (TREE_CODE (arg0) == BIT_AND_EXPR
4714 && integer_onep (TREE_OPERAND (arg0, 1)))))))
4716 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
4717 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
4721 if (code == EQ_EXPR)
4722 t = invert_truthvalue (t);
4727 if (TREE_CODE_CLASS (code) == '1')
4729 if (TREE_CODE (arg0) == COMPOUND_EXPR)
4730 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4731 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
4732 else if (TREE_CODE (arg0) == COND_EXPR)
4734 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
4735 fold (build1 (code, type, TREE_OPERAND (arg0, 1))),
4736 fold (build1 (code, type, TREE_OPERAND (arg0, 2)))));
4738 /* If this was a conversion, and all we did was to move into
4739 inside the COND_EXPR, bring it back out. But leave it if
4740 it is a conversion from integer to integer and the
4741 result precision is no wider than a word since such a
4742 conversion is cheap and may be optimized away by combine,
4743 while it couldn't if it were outside the COND_EXPR. Then return
4744 so we don't get into an infinite recursion loop taking the
4745 conversion out and then back in. */
4747 if ((code == NOP_EXPR || code == CONVERT_EXPR
4748 || code == NON_LVALUE_EXPR)
4749 && TREE_CODE (t) == COND_EXPR
4750 && TREE_CODE (TREE_OPERAND (t, 1)) == code
4751 && TREE_CODE (TREE_OPERAND (t, 2)) == code
4752 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
4753 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
4754 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
4756 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
4757 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
4758 t = build1 (code, type,
4760 TREE_TYPE (TREE_OPERAND
4761 (TREE_OPERAND (t, 1), 0)),
4762 TREE_OPERAND (t, 0),
4763 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
4764 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
4767 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
4768 return fold (build (COND_EXPR, type, arg0,
4769 fold (build1 (code, type, integer_one_node)),
4770 fold (build1 (code, type, integer_zero_node))));
4772 else if (TREE_CODE_CLASS (code) == '2'
4773 || TREE_CODE_CLASS (code) == '<')
4775 if (TREE_CODE (arg1) == COMPOUND_EXPR)
4776 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4777 fold (build (code, type,
4778 arg0, TREE_OPERAND (arg1, 1))));
4779 else if ((TREE_CODE (arg1) == COND_EXPR
4780 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
4781 && TREE_CODE_CLASS (code) != '<'))
4782 && (TREE_CODE (arg0) != COND_EXPR
4783 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4784 && (! TREE_SIDE_EFFECTS (arg0)
4785 || (global_bindings_p () == 0
4786 && ! contains_placeholder_p (arg0))))
4788 tree test, true_value, false_value;
4789 tree lhs = 0, rhs = 0;
4791 if (TREE_CODE (arg1) == COND_EXPR)
4793 test = TREE_OPERAND (arg1, 0);
4794 true_value = TREE_OPERAND (arg1, 1);
4795 false_value = TREE_OPERAND (arg1, 2);
4799 tree testtype = TREE_TYPE (arg1);
4801 true_value = convert (testtype, integer_one_node);
4802 false_value = convert (testtype, integer_zero_node);
4805 /* If ARG0 is complex we want to make sure we only evaluate
4806 it once. Though this is only required if it is volatile, it
4807 might be more efficient even if it is not. However, if we
4808 succeed in folding one part to a constant, we do not need
4809 to make this SAVE_EXPR. Since we do this optimization
4810 primarily to see if we do end up with constant and this
4811 SAVE_EXPR interferes with later optimizations, suppressing
4812 it when we can is important.
4814 If we are not in a function, we can't make a SAVE_EXPR, so don't
4815 try to do so. Don't try to see if the result is a constant
4816 if an arm is a COND_EXPR since we get exponential behavior
4819 if (TREE_CODE (arg0) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4820 && global_bindings_p () == 0
4821 && ((TREE_CODE (arg0) != VAR_DECL
4822 && TREE_CODE (arg0) != PARM_DECL)
4823 || TREE_SIDE_EFFECTS (arg0)))
4825 if (TREE_CODE (true_value) != COND_EXPR)
4826 lhs = fold (build (code, type, arg0, true_value));
4828 if (TREE_CODE (false_value) != COND_EXPR)
4829 rhs = fold (build (code, type, arg0, false_value));
4831 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4832 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4833 arg0 = save_expr (arg0), lhs = rhs = 0;
4837 lhs = fold (build (code, type, arg0, true_value));
4839 rhs = fold (build (code, type, arg0, false_value));
4841 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4843 if (TREE_CODE (arg0) == SAVE_EXPR)
4844 return build (COMPOUND_EXPR, type,
4845 convert (void_type_node, arg0),
4846 strip_compound_expr (test, arg0));
4848 return convert (type, test);
4851 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
4852 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4853 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4854 else if ((TREE_CODE (arg0) == COND_EXPR
4855 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
4856 && TREE_CODE_CLASS (code) != '<'))
4857 && (TREE_CODE (arg1) != COND_EXPR
4858 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4859 && (! TREE_SIDE_EFFECTS (arg1)
4860 || (global_bindings_p () == 0
4861 && ! contains_placeholder_p (arg1))))
4863 tree test, true_value, false_value;
4864 tree lhs = 0, rhs = 0;
4866 if (TREE_CODE (arg0) == COND_EXPR)
4868 test = TREE_OPERAND (arg0, 0);
4869 true_value = TREE_OPERAND (arg0, 1);
4870 false_value = TREE_OPERAND (arg0, 2);
4874 tree testtype = TREE_TYPE (arg0);
4876 true_value = convert (testtype, integer_one_node);
4877 false_value = convert (testtype, integer_zero_node);
4880 if (TREE_CODE (arg1) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4881 && global_bindings_p () == 0
4882 && ((TREE_CODE (arg1) != VAR_DECL
4883 && TREE_CODE (arg1) != PARM_DECL)
4884 || TREE_SIDE_EFFECTS (arg1)))
4886 if (TREE_CODE (true_value) != COND_EXPR)
4887 lhs = fold (build (code, type, true_value, arg1));
4889 if (TREE_CODE (false_value) != COND_EXPR)
4890 rhs = fold (build (code, type, false_value, arg1));
4892 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4893 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4894 arg1 = save_expr (arg1), lhs = rhs = 0;
4898 lhs = fold (build (code, type, true_value, arg1));
4901 rhs = fold (build (code, type, false_value, arg1));
4903 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4904 if (TREE_CODE (arg1) == SAVE_EXPR)
4905 return build (COMPOUND_EXPR, type,
4906 convert (void_type_node, arg1),
4907 strip_compound_expr (test, arg1));
4909 return convert (type, test);
4912 else if (TREE_CODE_CLASS (code) == '<'
4913 && TREE_CODE (arg0) == COMPOUND_EXPR)
4914 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4915 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4916 else if (TREE_CODE_CLASS (code) == '<'
4917 && TREE_CODE (arg1) == COMPOUND_EXPR)
4918 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4919 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
4931 return fold (DECL_INITIAL (t));
4936 case FIX_TRUNC_EXPR:
4937 /* Other kinds of FIX are not handled properly by fold_convert. */
4939 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
4940 return TREE_OPERAND (t, 0);
4942 /* Handle cases of two conversions in a row. */
4943 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
4944 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
4946 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4947 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
4948 tree final_type = TREE_TYPE (t);
4949 int inside_int = INTEGRAL_TYPE_P (inside_type);
4950 int inside_ptr = POINTER_TYPE_P (inside_type);
4951 int inside_float = FLOAT_TYPE_P (inside_type);
4952 int inside_prec = TYPE_PRECISION (inside_type);
4953 int inside_unsignedp = TREE_UNSIGNED (inside_type);
4954 int inter_int = INTEGRAL_TYPE_P (inter_type);
4955 int inter_ptr = POINTER_TYPE_P (inter_type);
4956 int inter_float = FLOAT_TYPE_P (inter_type);
4957 int inter_prec = TYPE_PRECISION (inter_type);
4958 int inter_unsignedp = TREE_UNSIGNED (inter_type);
4959 int final_int = INTEGRAL_TYPE_P (final_type);
4960 int final_ptr = POINTER_TYPE_P (final_type);
4961 int final_float = FLOAT_TYPE_P (final_type);
4962 int final_prec = TYPE_PRECISION (final_type);
4963 int final_unsignedp = TREE_UNSIGNED (final_type);
4965 /* In addition to the cases of two conversions in a row
4966 handled below, if we are converting something to its own
4967 type via an object of identical or wider precision, neither
4968 conversion is needed. */
4969 if (inside_type == final_type
4970 && ((inter_int && final_int) || (inter_float && final_float))
4971 && inter_prec >= final_prec)
4972 return TREE_OPERAND (TREE_OPERAND (t, 0), 0);
4974 /* Likewise, if the intermediate and final types are either both
4975 float or both integer, we don't need the middle conversion if
4976 it is wider than the final type and doesn't change the signedness
4977 (for integers). Avoid this if the final type is a pointer
4978 since then we sometimes need the inner conversion. Likewise if
4979 the outer has a precision not equal to the size of its mode. */
4980 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
4981 || (inter_float && inside_float))
4982 && inter_prec >= inside_prec
4983 && (inter_float || inter_unsignedp == inside_unsignedp)
4984 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
4985 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
4987 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4989 /* If we have a sign-extension of a zero-extended value, we can
4990 replace that by a single zero-extension. */
4991 if (inside_int && inter_int && final_int
4992 && inside_prec < inter_prec && inter_prec < final_prec
4993 && inside_unsignedp && !inter_unsignedp)
4994 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4996 /* Two conversions in a row are not needed unless:
4997 - some conversion is floating-point (overstrict for now), or
4998 - the intermediate type is narrower than both initial and
5000 - the intermediate type and innermost type differ in signedness,
5001 and the outermost type is wider than the intermediate, or
5002 - the initial type is a pointer type and the precisions of the
5003 intermediate and final types differ, or
5004 - the final type is a pointer type and the precisions of the
5005 initial and intermediate types differ. */
5006 if (! inside_float && ! inter_float && ! final_float
5007 && (inter_prec > inside_prec || inter_prec > final_prec)
5008 && ! (inside_int && inter_int
5009 && inter_unsignedp != inside_unsignedp
5010 && inter_prec < final_prec)
5011 && ((inter_unsignedp && inter_prec > inside_prec)
5012 == (final_unsignedp && final_prec > inter_prec))
5013 && ! (inside_ptr && inter_prec != final_prec)
5014 && ! (final_ptr && inside_prec != inter_prec)
5015 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5016 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5018 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5021 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5022 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5023 /* Detect assigning a bitfield. */
5024 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5025 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5027 /* Don't leave an assignment inside a conversion
5028 unless assigning a bitfield. */
5029 tree prev = TREE_OPERAND (t, 0);
5030 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5031 /* First do the assignment, then return converted constant. */
5032 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5038 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
5041 return fold_convert (t, arg0);
5043 #if 0 /* This loses on &"foo"[0]. */
5048 /* Fold an expression like: "foo"[2] */
5049 if (TREE_CODE (arg0) == STRING_CST
5050 && TREE_CODE (arg1) == INTEGER_CST
5051 && !TREE_INT_CST_HIGH (arg1)
5052 && (i = TREE_INT_CST_LOW (arg1)) < TREE_STRING_LENGTH (arg0))
5054 t = build_int_2 (TREE_STRING_POINTER (arg0)[i], 0);
5055 TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (arg0));
5056 force_fit_type (t, 0);
5063 if (TREE_CODE (arg0) == CONSTRUCTOR)
5065 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5072 TREE_CONSTANT (t) = wins;
5078 if (TREE_CODE (arg0) == INTEGER_CST)
5080 HOST_WIDE_INT low, high;
5081 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5082 TREE_INT_CST_HIGH (arg0),
5084 t = build_int_2 (low, high);
5085 TREE_TYPE (t) = type;
5087 = (TREE_OVERFLOW (arg0)
5088 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
5089 TREE_CONSTANT_OVERFLOW (t)
5090 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5092 else if (TREE_CODE (arg0) == REAL_CST)
5093 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5095 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5096 return TREE_OPERAND (arg0, 0);
5098 /* Convert - (a - b) to (b - a) for non-floating-point. */
5099 else if (TREE_CODE (arg0) == MINUS_EXPR
5100 && (! FLOAT_TYPE_P (type) || flag_fast_math))
5101 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
5102 TREE_OPERAND (arg0, 0));
5109 if (TREE_CODE (arg0) == INTEGER_CST)
5111 if (! TREE_UNSIGNED (type)
5112 && TREE_INT_CST_HIGH (arg0) < 0)
5114 HOST_WIDE_INT low, high;
5115 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5116 TREE_INT_CST_HIGH (arg0),
5118 t = build_int_2 (low, high);
5119 TREE_TYPE (t) = type;
5121 = (TREE_OVERFLOW (arg0)
5122 | force_fit_type (t, overflow));
5123 TREE_CONSTANT_OVERFLOW (t)
5124 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5127 else if (TREE_CODE (arg0) == REAL_CST)
5129 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5130 t = build_real (type,
5131 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5134 else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR)
5135 return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
5139 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5141 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5142 return build (COMPLEX_EXPR, TREE_TYPE (arg0),
5143 TREE_OPERAND (arg0, 0),
5144 negate_expr (TREE_OPERAND (arg0, 1)));
5145 else if (TREE_CODE (arg0) == COMPLEX_CST)
5146 return build_complex (type, TREE_OPERAND (arg0, 0),
5147 negate_expr (TREE_OPERAND (arg0, 1)));
5148 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5149 return fold (build (TREE_CODE (arg0), type,
5150 fold (build1 (CONJ_EXPR, type,
5151 TREE_OPERAND (arg0, 0))),
5152 fold (build1 (CONJ_EXPR,
5153 type, TREE_OPERAND (arg0, 1)))));
5154 else if (TREE_CODE (arg0) == CONJ_EXPR)
5155 return TREE_OPERAND (arg0, 0);
5161 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5162 ~ TREE_INT_CST_HIGH (arg0));
5163 TREE_TYPE (t) = type;
5164 force_fit_type (t, 0);
5165 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5166 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5168 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5169 return TREE_OPERAND (arg0, 0);
5173 /* A + (-B) -> A - B */
5174 if (TREE_CODE (arg1) == NEGATE_EXPR)
5175 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5176 /* (-A) + B -> B - A */
5177 if (TREE_CODE (arg0) == NEGATE_EXPR)
5178 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5179 else if (! FLOAT_TYPE_P (type))
5181 if (integer_zerop (arg1))
5182 return non_lvalue (convert (type, arg0));
5184 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5185 with a constant, and the two constants have no bits in common,
5186 we should treat this as a BIT_IOR_EXPR since this may produce more
5188 if (TREE_CODE (arg0) == BIT_AND_EXPR
5189 && TREE_CODE (arg1) == BIT_AND_EXPR
5190 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5191 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5192 && integer_zerop (const_binop (BIT_AND_EXPR,
5193 TREE_OPERAND (arg0, 1),
5194 TREE_OPERAND (arg1, 1), 0)))
5196 code = BIT_IOR_EXPR;
5200 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5201 (plus (plus (mult) (mult)) (foo)) so that we can
5202 take advantage of the factoring cases below. */
5203 if ((TREE_CODE (arg0) == PLUS_EXPR
5204 && TREE_CODE (arg1) == MULT_EXPR)
5205 || (TREE_CODE (arg1) == PLUS_EXPR
5206 && TREE_CODE (arg0) == MULT_EXPR))
5208 tree parg0, parg1, parg, marg;
5210 if (TREE_CODE (arg0) == PLUS_EXPR)
5211 parg = arg0, marg = arg1;
5213 parg = arg1, marg = arg0;
5214 parg0 = TREE_OPERAND (parg, 0);
5215 parg1 = TREE_OPERAND (parg, 1);
5219 if (TREE_CODE (parg0) == MULT_EXPR
5220 && TREE_CODE (parg1) != MULT_EXPR)
5221 return fold (build (PLUS_EXPR, type,
5222 fold (build (PLUS_EXPR, type, parg0, marg)),
5224 if (TREE_CODE (parg0) != MULT_EXPR
5225 && TREE_CODE (parg1) == MULT_EXPR)
5226 return fold (build (PLUS_EXPR, type,
5227 fold (build (PLUS_EXPR, type, parg1, marg)),
5231 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5233 tree arg00, arg01, arg10, arg11;
5234 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5236 /* (A * C) + (B * C) -> (A+B) * C.
5237 We are most concerned about the case where C is a constant,
5238 but other combinations show up during loop reduction. Since
5239 it is not difficult, try all four possibilities. */
5241 arg00 = TREE_OPERAND (arg0, 0);
5242 arg01 = TREE_OPERAND (arg0, 1);
5243 arg10 = TREE_OPERAND (arg1, 0);
5244 arg11 = TREE_OPERAND (arg1, 1);
5247 if (operand_equal_p (arg01, arg11, 0))
5248 same = arg01, alt0 = arg00, alt1 = arg10;
5249 else if (operand_equal_p (arg00, arg10, 0))
5250 same = arg00, alt0 = arg01, alt1 = arg11;
5251 else if (operand_equal_p (arg00, arg11, 0))
5252 same = arg00, alt0 = arg01, alt1 = arg10;
5253 else if (operand_equal_p (arg01, arg10, 0))
5254 same = arg01, alt0 = arg00, alt1 = arg11;
5256 /* No identical multiplicands; see if we can find a common
5257 power-of-two factor in non-power-of-two multiplies. This
5258 can help in multi-dimensional array access. */
5259 else if (TREE_CODE (arg01) == INTEGER_CST
5260 && TREE_CODE (arg11) == INTEGER_CST
5261 && TREE_INT_CST_HIGH (arg01) == 0
5262 && TREE_INT_CST_HIGH (arg11) == 0)
5264 HOST_WIDE_INT int01, int11, tmp;
5265 int01 = TREE_INT_CST_LOW (arg01);
5266 int11 = TREE_INT_CST_LOW (arg11);
5268 /* Move min of absolute values to int11. */
5269 if ((int01 >= 0 ? int01 : -int01)
5270 < (int11 >= 0 ? int11 : -int11))
5272 tmp = int01, int01 = int11, int11 = tmp;
5273 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5274 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5277 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5279 alt0 = fold (build (MULT_EXPR, type, arg00,
5280 build_int_2 (int01 / int11, 0)));
5287 return fold (build (MULT_EXPR, type,
5288 fold (build (PLUS_EXPR, type, alt0, alt1)),
5292 /* In IEEE floating point, x+0 may not equal x. */
5293 else if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5295 && real_zerop (arg1))
5296 return non_lvalue (convert (type, arg0));
5297 /* x+(-0) equals x, even for IEEE. */
5298 else if (TREE_CODE (arg1) == REAL_CST
5299 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
5300 return non_lvalue (convert (type, arg0));
5303 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5304 is a rotate of A by C1 bits. */
5305 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5306 is a rotate of A by B bits. */
5308 register enum tree_code code0, code1;
5309 code0 = TREE_CODE (arg0);
5310 code1 = TREE_CODE (arg1);
5311 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5312 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5313 && operand_equal_p (TREE_OPERAND (arg0, 0),
5314 TREE_OPERAND (arg1,0), 0)
5315 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5317 register tree tree01, tree11;
5318 register enum tree_code code01, code11;
5320 tree01 = TREE_OPERAND (arg0, 1);
5321 tree11 = TREE_OPERAND (arg1, 1);
5322 STRIP_NOPS (tree01);
5323 STRIP_NOPS (tree11);
5324 code01 = TREE_CODE (tree01);
5325 code11 = TREE_CODE (tree11);
5326 if (code01 == INTEGER_CST
5327 && code11 == INTEGER_CST
5328 && TREE_INT_CST_HIGH (tree01) == 0
5329 && TREE_INT_CST_HIGH (tree11) == 0
5330 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5331 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5332 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5333 code0 == LSHIFT_EXPR ? tree01 : tree11);
5334 else if (code11 == MINUS_EXPR)
5336 tree tree110, tree111;
5337 tree110 = TREE_OPERAND (tree11, 0);
5338 tree111 = TREE_OPERAND (tree11, 1);
5339 STRIP_NOPS (tree110);
5340 STRIP_NOPS (tree111);
5341 if (TREE_CODE (tree110) == INTEGER_CST
5342 && TREE_INT_CST_HIGH (tree110) == 0
5343 && (TREE_INT_CST_LOW (tree110)
5344 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5345 && operand_equal_p (tree01, tree111, 0))
5346 return build ((code0 == LSHIFT_EXPR
5349 type, TREE_OPERAND (arg0, 0), tree01);
5351 else if (code01 == MINUS_EXPR)
5353 tree tree010, tree011;
5354 tree010 = TREE_OPERAND (tree01, 0);
5355 tree011 = TREE_OPERAND (tree01, 1);
5356 STRIP_NOPS (tree010);
5357 STRIP_NOPS (tree011);
5358 if (TREE_CODE (tree010) == INTEGER_CST
5359 && TREE_INT_CST_HIGH (tree010) == 0
5360 && (TREE_INT_CST_LOW (tree010)
5361 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5362 && operand_equal_p (tree11, tree011, 0))
5363 return build ((code0 != LSHIFT_EXPR
5366 type, TREE_OPERAND (arg0, 0), tree11);
5373 /* In most languages, can't associate operations on floats through
5374 parentheses. Rather than remember where the parentheses were, we
5375 don't associate floats at all. It shouldn't matter much. However,
5376 associating multiplications is only very slightly inaccurate, so do
5377 that if -ffast-math is specified. */
5380 && (! FLOAT_TYPE_P (type)
5381 || (flag_fast_math && code != MULT_EXPR)))
5383 tree var0, con0, lit0, var1, con1, lit1;
5385 /* Split both trees into variables, constants, and literals. Then
5386 associate each group together, the constants with literals,
5387 then the result with variables. This increases the chances of
5388 literals being recombined later and of generating relocatable
5389 expressions for the sum of a constant and literal. */
5390 var0 = split_tree (arg0, code, &con0, &lit0, 0);
5391 var1 = split_tree (arg1, code, &con1, &lit1, code == MINUS_EXPR);
5393 /* Only do something if we found more than two objects. Otherwise,
5394 nothing has changed and we risk infinite recursion. */
5395 if (2 < ((var0 != 0) + (var1 != 0) + (con0 != 0) + (con1 != 0)
5396 + (lit0 != 0) + (lit1 != 0)))
5398 var0 = associate_trees (var0, var1, code, type);
5399 con0 = associate_trees (con0, con1, code, type);
5400 lit0 = associate_trees (lit0, lit1, code, type);
5401 con0 = associate_trees (con0, lit0, code, type);
5402 return convert (type, associate_trees (var0, con0, code, type));
5407 #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
5408 if (TREE_CODE (arg1) == REAL_CST)
5410 #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
5412 t1 = const_binop (code, arg0, arg1, 0);
5413 if (t1 != NULL_TREE)
5415 /* The return value should always have
5416 the same type as the original expression. */
5417 if (TREE_TYPE (t1) != TREE_TYPE (t))
5418 t1 = convert (TREE_TYPE (t), t1);
5425 /* A - (-B) -> A + B */
5426 if (TREE_CODE (arg1) == NEGATE_EXPR)
5427 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5428 /* (-A) - CST -> (-CST) - A for floating point (what about ints ?) */
5429 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
5431 fold (build (MINUS_EXPR, type,
5432 build_real (TREE_TYPE (arg1),
5433 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1))),
5434 TREE_OPERAND (arg0, 0)));
5436 if (! FLOAT_TYPE_P (type))
5438 if (! wins && integer_zerop (arg0))
5439 return negate_expr (arg1);
5440 if (integer_zerop (arg1))
5441 return non_lvalue (convert (type, arg0));
5443 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5444 about the case where C is a constant, just try one of the
5445 four possibilities. */
5447 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5448 && operand_equal_p (TREE_OPERAND (arg0, 1),
5449 TREE_OPERAND (arg1, 1), 0))
5450 return fold (build (MULT_EXPR, type,
5451 fold (build (MINUS_EXPR, type,
5452 TREE_OPERAND (arg0, 0),
5453 TREE_OPERAND (arg1, 0))),
5454 TREE_OPERAND (arg0, 1)));
5457 else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5460 /* Except with IEEE floating point, 0-x equals -x. */
5461 if (! wins && real_zerop (arg0))
5462 return negate_expr (arg1);
5463 /* Except with IEEE floating point, x-0 equals x. */
5464 if (real_zerop (arg1))
5465 return non_lvalue (convert (type, arg0));
5468 /* Fold &x - &x. This can happen from &x.foo - &x.
5469 This is unsafe for certain floats even in non-IEEE formats.
5470 In IEEE, it is unsafe because it does wrong for NaNs.
5471 Also note that operand_equal_p is always false if an operand
5474 if ((! FLOAT_TYPE_P (type) || flag_fast_math)
5475 && operand_equal_p (arg0, arg1, 0))
5476 return convert (type, integer_zero_node);
5481 /* (-A) * (-B) -> A * B */
5482 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5483 return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
5484 TREE_OPERAND (arg1, 0)));
5486 if (! FLOAT_TYPE_P (type))
5488 if (integer_zerop (arg1))
5489 return omit_one_operand (type, arg1, arg0);
5490 if (integer_onep (arg1))
5491 return non_lvalue (convert (type, arg0));
5493 /* (a * (1 << b)) is (a << b) */
5494 if (TREE_CODE (arg1) == LSHIFT_EXPR
5495 && integer_onep (TREE_OPERAND (arg1, 0)))
5496 return fold (build (LSHIFT_EXPR, type, arg0,
5497 TREE_OPERAND (arg1, 1)));
5498 if (TREE_CODE (arg0) == LSHIFT_EXPR
5499 && integer_onep (TREE_OPERAND (arg0, 0)))
5500 return fold (build (LSHIFT_EXPR, type, arg1,
5501 TREE_OPERAND (arg0, 1)));
5503 if (TREE_CODE (arg1) == INTEGER_CST
5504 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5506 return convert (type, tem);
5511 /* x*0 is 0, except for IEEE floating point. */
5512 if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5514 && real_zerop (arg1))
5515 return omit_one_operand (type, arg1, arg0);
5516 /* In IEEE floating point, x*1 is not equivalent to x for snans.
5517 However, ANSI says we can drop signals,
5518 so we can do this anyway. */
5519 if (real_onep (arg1))
5520 return non_lvalue (convert (type, arg0));
5522 if (! wins && real_twop (arg1) && global_bindings_p () == 0
5523 && ! contains_placeholder_p (arg0))
5525 tree arg = save_expr (arg0);
5526 return build (PLUS_EXPR, type, arg, arg);
5533 if (integer_all_onesp (arg1))
5534 return omit_one_operand (type, arg1, arg0);
5535 if (integer_zerop (arg1))
5536 return non_lvalue (convert (type, arg0));
5537 t1 = distribute_bit_expr (code, type, arg0, arg1);
5538 if (t1 != NULL_TREE)
5541 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
5543 This results in more efficient code for machines without a NAND
5544 instruction. Combine will canonicalize to the first form
5545 which will allow use of NAND instructions provided by the
5546 backend if they exist. */
5547 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5548 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5550 return fold (build1 (BIT_NOT_EXPR, type,
5551 build (BIT_AND_EXPR, type,
5552 TREE_OPERAND (arg0, 0),
5553 TREE_OPERAND (arg1, 0))));
5556 /* See if this can be simplified into a rotate first. If that
5557 is unsuccessful continue in the association code. */
5561 if (integer_zerop (arg1))
5562 return non_lvalue (convert (type, arg0));
5563 if (integer_all_onesp (arg1))
5564 return fold (build1 (BIT_NOT_EXPR, type, arg0));
5566 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
5567 with a constant, and the two constants have no bits in common,
5568 we should treat this as a BIT_IOR_EXPR since this may produce more
5570 if (TREE_CODE (arg0) == BIT_AND_EXPR
5571 && TREE_CODE (arg1) == BIT_AND_EXPR
5572 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5573 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5574 && integer_zerop (const_binop (BIT_AND_EXPR,
5575 TREE_OPERAND (arg0, 1),
5576 TREE_OPERAND (arg1, 1), 0)))
5578 code = BIT_IOR_EXPR;
5582 /* See if this can be simplified into a rotate first. If that
5583 is unsuccessful continue in the association code. */
5588 if (integer_all_onesp (arg1))
5589 return non_lvalue (convert (type, arg0));
5590 if (integer_zerop (arg1))
5591 return omit_one_operand (type, arg1, arg0);
5592 t1 = distribute_bit_expr (code, type, arg0, arg1);
5593 if (t1 != NULL_TREE)
5595 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5596 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == NOP_EXPR
5597 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0))))
5599 int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0)));
5600 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5601 && (~TREE_INT_CST_LOW (arg0)
5602 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5603 return build1 (NOP_EXPR, type, TREE_OPERAND (arg1, 0));
5605 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
5606 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5608 int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
5609 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5610 && (~TREE_INT_CST_LOW (arg1)
5611 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5612 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
5615 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
5617 This results in more efficient code for machines without a NOR
5618 instruction. Combine will canonicalize to the first form
5619 which will allow use of NOR instructions provided by the
5620 backend if they exist. */
5621 if (TREE_CODE (arg0) == BIT_NOT_EXPR
5622 && TREE_CODE (arg1) == BIT_NOT_EXPR)
5624 return fold (build1 (BIT_NOT_EXPR, type,
5625 build (BIT_IOR_EXPR, type,
5626 TREE_OPERAND (arg0, 0),
5627 TREE_OPERAND (arg1, 0))));
5632 case BIT_ANDTC_EXPR:
5633 if (integer_all_onesp (arg0))
5634 return non_lvalue (convert (type, arg1));
5635 if (integer_zerop (arg0))
5636 return omit_one_operand (type, arg0, arg1);
5637 if (TREE_CODE (arg1) == INTEGER_CST)
5639 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
5640 code = BIT_AND_EXPR;
5646 /* In most cases, do nothing with a divide by zero. */
5647 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5648 #ifndef REAL_INFINITY
5649 if (TREE_CODE (arg1) == REAL_CST && real_zerop (arg1))
5652 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5654 /* (-A) / (-B) -> A / B */
5655 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5656 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
5657 TREE_OPERAND (arg1, 0)));
5659 /* In IEEE floating point, x/1 is not equivalent to x for snans.
5660 However, ANSI says we can drop signals, so we can do this anyway. */
5661 if (real_onep (arg1))
5662 return non_lvalue (convert (type, arg0));
5664 /* If ARG1 is a constant, we can convert this to a multiply by the
5665 reciprocal. This does not have the same rounding properties,
5666 so only do this if -ffast-math. We can actually always safely
5667 do it if ARG1 is a power of two, but it's hard to tell if it is
5668 or not in a portable manner. */
5669 if (TREE_CODE (arg1) == REAL_CST)
5672 && 0 != (tem = const_binop (code, build_real (type, dconst1),
5674 return fold (build (MULT_EXPR, type, arg0, tem));
5675 /* Find the reciprocal if optimizing and the result is exact. */
5679 r = TREE_REAL_CST (arg1);
5680 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
5682 tem = build_real (type, r);
5683 return fold (build (MULT_EXPR, type, arg0, tem));
5689 case TRUNC_DIV_EXPR:
5690 case ROUND_DIV_EXPR:
5691 case FLOOR_DIV_EXPR:
5693 case EXACT_DIV_EXPR:
5694 if (integer_onep (arg1))
5695 return non_lvalue (convert (type, arg0));
5696 if (integer_zerop (arg1))
5699 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
5700 operation, EXACT_DIV_EXPR.
5702 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
5703 At one time others generated faster code, it's not clear if they do
5704 after the last round to changes to the DIV code in expmed.c. */
5705 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
5706 && multiple_of_p (type, arg0, arg1))
5707 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
5709 if (TREE_CODE (arg1) == INTEGER_CST
5710 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5712 return convert (type, tem);
5717 case FLOOR_MOD_EXPR:
5718 case ROUND_MOD_EXPR:
5719 case TRUNC_MOD_EXPR:
5720 if (integer_onep (arg1))
5721 return omit_one_operand (type, integer_zero_node, arg0);
5722 if (integer_zerop (arg1))
5725 if (TREE_CODE (arg1) == INTEGER_CST
5726 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
5728 return convert (type, tem);
5736 if (integer_zerop (arg1))
5737 return non_lvalue (convert (type, arg0));
5738 /* Since negative shift count is not well-defined,
5739 don't try to compute it in the compiler. */
5740 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
5742 /* Rewrite an LROTATE_EXPR by a constant into an
5743 RROTATE_EXPR by a new constant. */
5744 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
5746 TREE_SET_CODE (t, RROTATE_EXPR);
5747 code = RROTATE_EXPR;
5748 TREE_OPERAND (t, 1) = arg1
5751 convert (TREE_TYPE (arg1),
5752 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
5754 if (tree_int_cst_sgn (arg1) < 0)
5758 /* If we have a rotate of a bit operation with the rotate count and
5759 the second operand of the bit operation both constant,
5760 permute the two operations. */
5761 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5762 && (TREE_CODE (arg0) == BIT_AND_EXPR
5763 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
5764 || TREE_CODE (arg0) == BIT_IOR_EXPR
5765 || TREE_CODE (arg0) == BIT_XOR_EXPR)
5766 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5767 return fold (build (TREE_CODE (arg0), type,
5768 fold (build (code, type,
5769 TREE_OPERAND (arg0, 0), arg1)),
5770 fold (build (code, type,
5771 TREE_OPERAND (arg0, 1), arg1))));
5773 /* Two consecutive rotates adding up to the width of the mode can
5775 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5776 && TREE_CODE (arg0) == RROTATE_EXPR
5777 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5778 && TREE_INT_CST_HIGH (arg1) == 0
5779 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
5780 && ((TREE_INT_CST_LOW (arg1)
5781 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
5782 == GET_MODE_BITSIZE (TYPE_MODE (type))))
5783 return TREE_OPERAND (arg0, 0);
5788 if (operand_equal_p (arg0, arg1, 0))
5790 if (INTEGRAL_TYPE_P (type)
5791 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
5792 return omit_one_operand (type, arg1, arg0);
5796 if (operand_equal_p (arg0, arg1, 0))
5798 if (INTEGRAL_TYPE_P (type)
5799 && TYPE_MAX_VALUE (type)
5800 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
5801 return omit_one_operand (type, arg1, arg0);
5804 case TRUTH_NOT_EXPR:
5805 /* Note that the operand of this must be an int
5806 and its values must be 0 or 1.
5807 ("true" is a fixed value perhaps depending on the language,
5808 but we don't handle values other than 1 correctly yet.) */
5809 tem = invert_truthvalue (arg0);
5810 /* Avoid infinite recursion. */
5811 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
5813 return convert (type, tem);
5815 case TRUTH_ANDIF_EXPR:
5816 /* Note that the operands of this must be ints
5817 and their values must be 0 or 1.
5818 ("true" is a fixed value perhaps depending on the language.) */
5819 /* If first arg is constant zero, return it. */
5820 if (integer_zerop (arg0))
5822 case TRUTH_AND_EXPR:
5823 /* If either arg is constant true, drop it. */
5824 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5825 return non_lvalue (arg1);
5826 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5827 return non_lvalue (arg0);
5828 /* If second arg is constant zero, result is zero, but first arg
5829 must be evaluated. */
5830 if (integer_zerop (arg1))
5831 return omit_one_operand (type, arg1, arg0);
5832 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
5833 case will be handled here. */
5834 if (integer_zerop (arg0))
5835 return omit_one_operand (type, arg0, arg1);
5838 /* We only do these simplifications if we are optimizing. */
5842 /* Check for things like (A || B) && (A || C). We can convert this
5843 to A || (B && C). Note that either operator can be any of the four
5844 truth and/or operations and the transformation will still be
5845 valid. Also note that we only care about order for the
5846 ANDIF and ORIF operators. If B contains side effects, this
5847 might change the truth-value of A. */
5848 if (TREE_CODE (arg0) == TREE_CODE (arg1)
5849 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
5850 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
5851 || TREE_CODE (arg0) == TRUTH_AND_EXPR
5852 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
5853 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
5855 tree a00 = TREE_OPERAND (arg0, 0);
5856 tree a01 = TREE_OPERAND (arg0, 1);
5857 tree a10 = TREE_OPERAND (arg1, 0);
5858 tree a11 = TREE_OPERAND (arg1, 1);
5859 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
5860 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
5861 && (code == TRUTH_AND_EXPR
5862 || code == TRUTH_OR_EXPR));
5864 if (operand_equal_p (a00, a10, 0))
5865 return fold (build (TREE_CODE (arg0), type, a00,
5866 fold (build (code, type, a01, a11))));
5867 else if (commutative && operand_equal_p (a00, a11, 0))
5868 return fold (build (TREE_CODE (arg0), type, a00,
5869 fold (build (code, type, a01, a10))));
5870 else if (commutative && operand_equal_p (a01, a10, 0))
5871 return fold (build (TREE_CODE (arg0), type, a01,
5872 fold (build (code, type, a00, a11))));
5874 /* This case if tricky because we must either have commutative
5875 operators or else A10 must not have side-effects. */
5877 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
5878 && operand_equal_p (a01, a11, 0))
5879 return fold (build (TREE_CODE (arg0), type,
5880 fold (build (code, type, a00, a10)),
5884 /* See if we can build a range comparison. */
5885 if (0 != (tem = fold_range_test (t)))
5888 /* Check for the possibility of merging component references. If our
5889 lhs is another similar operation, try to merge its rhs with our
5890 rhs. Then try to merge our lhs and rhs. */
5891 if (TREE_CODE (arg0) == code
5892 && 0 != (tem = fold_truthop (code, type,
5893 TREE_OPERAND (arg0, 1), arg1)))
5894 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
5896 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
5901 case TRUTH_ORIF_EXPR:
5902 /* Note that the operands of this must be ints
5903 and their values must be 0 or true.
5904 ("true" is a fixed value perhaps depending on the language.) */
5905 /* If first arg is constant true, return it. */
5906 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5909 /* If either arg is constant zero, drop it. */
5910 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
5911 return non_lvalue (arg1);
5912 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1))
5913 return non_lvalue (arg0);
5914 /* If second arg is constant true, result is true, but we must
5915 evaluate first arg. */
5916 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5917 return omit_one_operand (type, arg1, arg0);
5918 /* Likewise for first arg, but note this only occurs here for
5920 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5921 return omit_one_operand (type, arg0, arg1);
5924 case TRUTH_XOR_EXPR:
5925 /* If either arg is constant zero, drop it. */
5926 if (integer_zerop (arg0))
5927 return non_lvalue (arg1);
5928 if (integer_zerop (arg1))
5929 return non_lvalue (arg0);
5930 /* If either arg is constant true, this is a logical inversion. */
5931 if (integer_onep (arg0))
5932 return non_lvalue (invert_truthvalue (arg1));
5933 if (integer_onep (arg1))
5934 return non_lvalue (invert_truthvalue (arg0));
5943 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
5945 /* (-a) CMP (-b) -> b CMP a */
5946 if (TREE_CODE (arg0) == NEGATE_EXPR
5947 && TREE_CODE (arg1) == NEGATE_EXPR)
5948 return fold (build (code, type, TREE_OPERAND (arg1, 0),
5949 TREE_OPERAND (arg0, 0)));
5950 /* (-a) CMP CST -> a swap(CMP) (-CST) */
5951 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST)
5954 (swap_tree_comparison (code), type,
5955 TREE_OPERAND (arg0, 0),
5956 build_real (TREE_TYPE (arg1),
5957 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1)))));
5958 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
5959 /* a CMP (-0) -> a CMP 0 */
5960 if (TREE_CODE (arg1) == REAL_CST
5961 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
5962 return fold (build (code, type, arg0,
5963 build_real (TREE_TYPE (arg1), dconst0)));
5967 /* If one arg is a constant integer, put it last. */
5968 if (TREE_CODE (arg0) == INTEGER_CST
5969 && TREE_CODE (arg1) != INTEGER_CST)
5971 TREE_OPERAND (t, 0) = arg1;
5972 TREE_OPERAND (t, 1) = arg0;
5973 arg0 = TREE_OPERAND (t, 0);
5974 arg1 = TREE_OPERAND (t, 1);
5975 code = swap_tree_comparison (code);
5976 TREE_SET_CODE (t, code);
5979 /* Convert foo++ == CONST into ++foo == CONST + INCR.
5980 First, see if one arg is constant; find the constant arg
5981 and the other one. */
5983 tree constop = 0, varop = NULL_TREE;
5984 int constopnum = -1;
5986 if (TREE_CONSTANT (arg1))
5987 constopnum = 1, constop = arg1, varop = arg0;
5988 if (TREE_CONSTANT (arg0))
5989 constopnum = 0, constop = arg0, varop = arg1;
5991 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
5993 /* This optimization is invalid for ordered comparisons
5994 if CONST+INCR overflows or if foo+incr might overflow.
5995 This optimization is invalid for floating point due to rounding.
5996 For pointer types we assume overflow doesn't happen. */
5997 if (POINTER_TYPE_P (TREE_TYPE (varop))
5998 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
5999 && (code == EQ_EXPR || code == NE_EXPR)))
6002 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
6003 constop, TREE_OPERAND (varop, 1)));
6004 TREE_SET_CODE (varop, PREINCREMENT_EXPR);
6006 /* If VAROP is a reference to a bitfield, we must mask
6007 the constant by the width of the field. */
6008 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6009 && DECL_BIT_FIELD(TREE_OPERAND
6010 (TREE_OPERAND (varop, 0), 1)))
6013 = TREE_INT_CST_LOW (DECL_SIZE
6015 (TREE_OPERAND (varop, 0), 1)));
6016 tree mask, unsigned_type;
6018 tree folded_compare;
6020 /* First check whether the comparison would come out
6021 always the same. If we don't do that we would
6022 change the meaning with the masking. */
6023 if (constopnum == 0)
6024 folded_compare = fold (build (code, type, constop,
6025 TREE_OPERAND (varop, 0)));
6027 folded_compare = fold (build (code, type,
6028 TREE_OPERAND (varop, 0),
6030 if (integer_zerop (folded_compare)
6031 || integer_onep (folded_compare))
6032 return omit_one_operand (type, folded_compare, varop);
6034 unsigned_type = type_for_size (size, 1);
6035 precision = TYPE_PRECISION (unsigned_type);
6036 mask = build_int_2 (~0, ~0);
6037 TREE_TYPE (mask) = unsigned_type;
6038 force_fit_type (mask, 0);
6039 mask = const_binop (RSHIFT_EXPR, mask,
6040 size_int (precision - size), 0);
6041 newconst = fold (build (BIT_AND_EXPR,
6042 TREE_TYPE (varop), newconst,
6043 convert (TREE_TYPE (varop),
6048 t = build (code, type, TREE_OPERAND (t, 0),
6049 TREE_OPERAND (t, 1));
6050 TREE_OPERAND (t, constopnum) = newconst;
6054 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
6056 if (POINTER_TYPE_P (TREE_TYPE (varop))
6057 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6058 && (code == EQ_EXPR || code == NE_EXPR)))
6061 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
6062 constop, TREE_OPERAND (varop, 1)));
6063 TREE_SET_CODE (varop, PREDECREMENT_EXPR);
6065 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6066 && DECL_BIT_FIELD(TREE_OPERAND
6067 (TREE_OPERAND (varop, 0), 1)))
6070 = TREE_INT_CST_LOW (DECL_SIZE
6072 (TREE_OPERAND (varop, 0), 1)));
6073 tree mask, unsigned_type;
6075 tree folded_compare;
6077 if (constopnum == 0)
6078 folded_compare = fold (build (code, type, constop,
6079 TREE_OPERAND (varop, 0)));
6081 folded_compare = fold (build (code, type,
6082 TREE_OPERAND (varop, 0),
6084 if (integer_zerop (folded_compare)
6085 || integer_onep (folded_compare))
6086 return omit_one_operand (type, folded_compare, varop);
6088 unsigned_type = type_for_size (size, 1);
6089 precision = TYPE_PRECISION (unsigned_type);
6090 mask = build_int_2 (~0, ~0);
6091 TREE_TYPE (mask) = TREE_TYPE (varop);
6092 force_fit_type (mask, 0);
6093 mask = const_binop (RSHIFT_EXPR, mask,
6094 size_int (precision - size), 0);
6095 newconst = fold (build (BIT_AND_EXPR,
6096 TREE_TYPE (varop), newconst,
6097 convert (TREE_TYPE (varop),
6102 t = build (code, type, TREE_OPERAND (t, 0),
6103 TREE_OPERAND (t, 1));
6104 TREE_OPERAND (t, constopnum) = newconst;
6110 /* Change X >= CST to X > (CST - 1) if CST is positive. */
6111 if (TREE_CODE (arg1) == INTEGER_CST
6112 && TREE_CODE (arg0) != INTEGER_CST
6113 && tree_int_cst_sgn (arg1) > 0)
6115 switch (TREE_CODE (t))
6119 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6120 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6125 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6126 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6134 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6135 a MINUS_EXPR of a constant, we can convert it into a comparison with
6136 a revised constant as long as no overflow occurs. */
6137 if ((code == EQ_EXPR || code == NE_EXPR)
6138 && TREE_CODE (arg1) == INTEGER_CST
6139 && (TREE_CODE (arg0) == PLUS_EXPR
6140 || TREE_CODE (arg0) == MINUS_EXPR)
6141 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6142 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6143 ? MINUS_EXPR : PLUS_EXPR,
6144 arg1, TREE_OPERAND (arg0, 1), 0))
6145 && ! TREE_CONSTANT_OVERFLOW (tem))
6146 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6148 /* Similarly for a NEGATE_EXPR. */
6149 else if ((code == EQ_EXPR || code == NE_EXPR)
6150 && TREE_CODE (arg0) == NEGATE_EXPR
6151 && TREE_CODE (arg1) == INTEGER_CST
6152 && 0 != (tem = negate_expr (arg1))
6153 && TREE_CODE (tem) == INTEGER_CST
6154 && ! TREE_CONSTANT_OVERFLOW (tem))
6155 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6157 /* If we have X - Y == 0, we can convert that to X == Y and similarly
6158 for !=. Don't do this for ordered comparisons due to overflow. */
6159 else if ((code == NE_EXPR || code == EQ_EXPR)
6160 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
6161 return fold (build (code, type,
6162 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
6164 /* If we are widening one operand of an integer comparison,
6165 see if the other operand is similarly being widened. Perhaps we
6166 can do the comparison in the narrower type. */
6167 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
6168 && TREE_CODE (arg0) == NOP_EXPR
6169 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
6170 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
6171 && (TREE_TYPE (t1) == TREE_TYPE (tem)
6172 || (TREE_CODE (t1) == INTEGER_CST
6173 && int_fits_type_p (t1, TREE_TYPE (tem)))))
6174 return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
6176 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
6177 constant, we can simplify it. */
6178 else if (TREE_CODE (arg1) == INTEGER_CST
6179 && (TREE_CODE (arg0) == MIN_EXPR
6180 || TREE_CODE (arg0) == MAX_EXPR)
6181 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6182 return optimize_minmax_comparison (t);
6184 /* If we are comparing an ABS_EXPR with a constant, we can
6185 convert all the cases into explicit comparisons, but they may
6186 well not be faster than doing the ABS and one comparison.
6187 But ABS (X) <= C is a range comparison, which becomes a subtraction
6188 and a comparison, and is probably faster. */
6189 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6190 && TREE_CODE (arg0) == ABS_EXPR
6191 && ! TREE_SIDE_EFFECTS (arg0)
6192 && (0 != (tem = negate_expr (arg1)))
6193 && TREE_CODE (tem) == INTEGER_CST
6194 && ! TREE_CONSTANT_OVERFLOW (tem))
6195 return fold (build (TRUTH_ANDIF_EXPR, type,
6196 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
6197 build (LE_EXPR, type,
6198 TREE_OPERAND (arg0, 0), arg1)));
6200 /* If this is an EQ or NE comparison with zero and ARG0 is
6201 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
6202 two operations, but the latter can be done in one less insn
6203 on machines that have only two-operand insns or on which a
6204 constant cannot be the first operand. */
6205 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
6206 && TREE_CODE (arg0) == BIT_AND_EXPR)
6208 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
6209 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
6211 fold (build (code, type,
6212 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6214 TREE_TYPE (TREE_OPERAND (arg0, 0)),
6215 TREE_OPERAND (arg0, 1),
6216 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
6217 convert (TREE_TYPE (arg0),
6220 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
6221 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
6223 fold (build (code, type,
6224 build (BIT_AND_EXPR, TREE_TYPE (arg0),
6226 TREE_TYPE (TREE_OPERAND (arg0, 1)),
6227 TREE_OPERAND (arg0, 0),
6228 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
6229 convert (TREE_TYPE (arg0),
6234 /* If this is an NE or EQ comparison of zero against the result of a
6235 signed MOD operation whose second operand is a power of 2, make
6236 the MOD operation unsigned since it is simpler and equivalent. */
6237 if ((code == NE_EXPR || code == EQ_EXPR)
6238 && integer_zerop (arg1)
6239 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
6240 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
6241 || TREE_CODE (arg0) == CEIL_MOD_EXPR
6242 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
6243 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
6244 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6246 tree newtype = unsigned_type (TREE_TYPE (arg0));
6247 tree newmod = build (TREE_CODE (arg0), newtype,
6248 convert (newtype, TREE_OPERAND (arg0, 0)),
6249 convert (newtype, TREE_OPERAND (arg0, 1)));
6251 return build (code, type, newmod, convert (newtype, arg1));
6254 /* If this is an NE comparison of zero with an AND of one, remove the
6255 comparison since the AND will give the correct value. */
6256 if (code == NE_EXPR && integer_zerop (arg1)
6257 && TREE_CODE (arg0) == BIT_AND_EXPR
6258 && integer_onep (TREE_OPERAND (arg0, 1)))
6259 return convert (type, arg0);
6261 /* If we have (A & C) == C where C is a power of 2, convert this into
6262 (A & C) != 0. Similarly for NE_EXPR. */
6263 if ((code == EQ_EXPR || code == NE_EXPR)
6264 && TREE_CODE (arg0) == BIT_AND_EXPR
6265 && integer_pow2p (TREE_OPERAND (arg0, 1))
6266 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
6267 return build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
6268 arg0, integer_zero_node);
6270 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
6271 and similarly for >= into !=. */
6272 if ((code == LT_EXPR || code == GE_EXPR)
6273 && TREE_UNSIGNED (TREE_TYPE (arg0))
6274 && TREE_CODE (arg1) == LSHIFT_EXPR
6275 && integer_onep (TREE_OPERAND (arg1, 0)))
6276 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6277 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6278 TREE_OPERAND (arg1, 1)),
6279 convert (TREE_TYPE (arg0), integer_zero_node));
6281 else if ((code == LT_EXPR || code == GE_EXPR)
6282 && TREE_UNSIGNED (TREE_TYPE (arg0))
6283 && (TREE_CODE (arg1) == NOP_EXPR
6284 || TREE_CODE (arg1) == CONVERT_EXPR)
6285 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
6286 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
6288 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
6289 convert (TREE_TYPE (arg0),
6290 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
6291 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
6292 convert (TREE_TYPE (arg0), integer_zero_node));
6294 /* Simplify comparison of something with itself. (For IEEE
6295 floating-point, we can only do some of these simplifications.) */
6296 if (operand_equal_p (arg0, arg1, 0))
6303 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
6304 return constant_boolean_node (1, type);
6306 TREE_SET_CODE (t, code);
6310 /* For NE, we can only do this simplification if integer. */
6311 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
6313 /* ... fall through ... */
6316 return constant_boolean_node (0, type);
6322 /* An unsigned comparison against 0 can be simplified. */
6323 if (integer_zerop (arg1)
6324 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6325 || POINTER_TYPE_P (TREE_TYPE (arg1)))
6326 && TREE_UNSIGNED (TREE_TYPE (arg1)))
6328 switch (TREE_CODE (t))
6332 TREE_SET_CODE (t, NE_EXPR);
6336 TREE_SET_CODE (t, EQ_EXPR);
6339 return omit_one_operand (type,
6340 convert (type, integer_one_node),
6343 return omit_one_operand (type,
6344 convert (type, integer_zero_node),
6351 /* Comparisons with the highest or lowest possible integer of
6352 the specified size will have known values and an unsigned
6353 <= 0x7fffffff can be simplified. */
6355 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
6357 if (TREE_CODE (arg1) == INTEGER_CST
6358 && ! TREE_CONSTANT_OVERFLOW (arg1)
6359 && width <= HOST_BITS_PER_WIDE_INT
6360 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6361 || POINTER_TYPE_P (TREE_TYPE (arg1))))
6363 if (TREE_INT_CST_HIGH (arg1) == 0
6364 && (TREE_INT_CST_LOW (arg1)
6365 == ((HOST_WIDE_INT) 1 << (width - 1)) - 1)
6366 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6367 switch (TREE_CODE (t))
6370 return omit_one_operand (type,
6371 convert (type, integer_zero_node),
6374 TREE_SET_CODE (t, EQ_EXPR);
6378 return omit_one_operand (type,
6379 convert (type, integer_one_node),
6382 TREE_SET_CODE (t, NE_EXPR);
6389 else if (TREE_INT_CST_HIGH (arg1) == -1
6390 && (- TREE_INT_CST_LOW (arg1)
6391 == ((HOST_WIDE_INT) 1 << (width - 1)))
6392 && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
6393 switch (TREE_CODE (t))
6396 return omit_one_operand (type,
6397 convert (type, integer_zero_node),
6400 TREE_SET_CODE (t, EQ_EXPR);
6404 return omit_one_operand (type,
6405 convert (type, integer_one_node),
6408 TREE_SET_CODE (t, NE_EXPR);
6415 else if (TREE_INT_CST_HIGH (arg1) == 0
6416 && (TREE_INT_CST_LOW (arg1)
6417 == ((HOST_WIDE_INT) 1 << (width - 1)) - 1)
6418 && TREE_UNSIGNED (TREE_TYPE (arg1)))
6420 switch (TREE_CODE (t))
6423 return fold (build (GE_EXPR, type,
6424 convert (signed_type (TREE_TYPE (arg0)),
6426 convert (signed_type (TREE_TYPE (arg1)),
6427 integer_zero_node)));
6429 return fold (build (LT_EXPR, type,
6430 convert (signed_type (TREE_TYPE (arg0)),
6432 convert (signed_type (TREE_TYPE (arg1)),
6433 integer_zero_node)));
6441 /* If we are comparing an expression that just has comparisons
6442 of two integer values, arithmetic expressions of those comparisons,
6443 and constants, we can simplify it. There are only three cases
6444 to check: the two values can either be equal, the first can be
6445 greater, or the second can be greater. Fold the expression for
6446 those three values. Since each value must be 0 or 1, we have
6447 eight possibilities, each of which corresponds to the constant 0
6448 or 1 or one of the six possible comparisons.
6450 This handles common cases like (a > b) == 0 but also handles
6451 expressions like ((x > y) - (y > x)) > 0, which supposedly
6452 occur in macroized code. */
6454 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
6456 tree cval1 = 0, cval2 = 0;
6459 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
6460 /* Don't handle degenerate cases here; they should already
6461 have been handled anyway. */
6462 && cval1 != 0 && cval2 != 0
6463 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
6464 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
6465 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
6466 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
6467 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
6468 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
6469 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
6471 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
6472 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
6474 /* We can't just pass T to eval_subst in case cval1 or cval2
6475 was the same as ARG1. */
6478 = fold (build (code, type,
6479 eval_subst (arg0, cval1, maxval, cval2, minval),
6482 = fold (build (code, type,
6483 eval_subst (arg0, cval1, maxval, cval2, maxval),
6486 = fold (build (code, type,
6487 eval_subst (arg0, cval1, minval, cval2, maxval),
6490 /* All three of these results should be 0 or 1. Confirm they
6491 are. Then use those values to select the proper code
6494 if ((integer_zerop (high_result)
6495 || integer_onep (high_result))
6496 && (integer_zerop (equal_result)
6497 || integer_onep (equal_result))
6498 && (integer_zerop (low_result)
6499 || integer_onep (low_result)))
6501 /* Make a 3-bit mask with the high-order bit being the
6502 value for `>', the next for '=', and the low for '<'. */
6503 switch ((integer_onep (high_result) * 4)
6504 + (integer_onep (equal_result) * 2)
6505 + integer_onep (low_result))
6509 return omit_one_operand (type, integer_zero_node, arg0);
6530 return omit_one_operand (type, integer_one_node, arg0);
6533 t = build (code, type, cval1, cval2);
6535 return save_expr (t);
6542 /* If this is a comparison of a field, we may be able to simplify it. */
6543 if ((TREE_CODE (arg0) == COMPONENT_REF
6544 || TREE_CODE (arg0) == BIT_FIELD_REF)
6545 && (code == EQ_EXPR || code == NE_EXPR)
6546 /* Handle the constant case even without -O
6547 to make sure the warnings are given. */
6548 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
6550 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
6554 /* If this is a comparison of complex values and either or both sides
6555 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6556 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6557 This may prevent needless evaluations. */
6558 if ((code == EQ_EXPR || code == NE_EXPR)
6559 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
6560 && (TREE_CODE (arg0) == COMPLEX_EXPR
6561 || TREE_CODE (arg1) == COMPLEX_EXPR
6562 || TREE_CODE (arg0) == COMPLEX_CST
6563 || TREE_CODE (arg1) == COMPLEX_CST))
6565 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
6566 tree real0, imag0, real1, imag1;
6568 arg0 = save_expr (arg0);
6569 arg1 = save_expr (arg1);
6570 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
6571 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
6572 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
6573 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
6575 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
6578 fold (build (code, type, real0, real1)),
6579 fold (build (code, type, imag0, imag1))));
6582 /* From here on, the only cases we handle are when the result is
6583 known to be a constant.
6585 To compute GT, swap the arguments and do LT.
6586 To compute GE, do LT and invert the result.
6587 To compute LE, swap the arguments, do LT and invert the result.
6588 To compute NE, do EQ and invert the result.
6590 Therefore, the code below must handle only EQ and LT. */
6592 if (code == LE_EXPR || code == GT_EXPR)
6594 tem = arg0, arg0 = arg1, arg1 = tem;
6595 code = swap_tree_comparison (code);
6598 /* Note that it is safe to invert for real values here because we
6599 will check below in the one case that it matters. */
6603 if (code == NE_EXPR || code == GE_EXPR)
6606 code = invert_tree_comparison (code);
6609 /* Compute a result for LT or EQ if args permit;
6610 otherwise return T. */
6611 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
6613 if (code == EQ_EXPR)
6614 t1 = build_int_2 ((TREE_INT_CST_LOW (arg0)
6615 == TREE_INT_CST_LOW (arg1))
6616 && (TREE_INT_CST_HIGH (arg0)
6617 == TREE_INT_CST_HIGH (arg1)),
6620 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
6621 ? INT_CST_LT_UNSIGNED (arg0, arg1)
6622 : INT_CST_LT (arg0, arg1)),
6626 #if 0 /* This is no longer useful, but breaks some real code. */
6627 /* Assume a nonexplicit constant cannot equal an explicit one,
6628 since such code would be undefined anyway.
6629 Exception: on sysvr4, using #pragma weak,
6630 a label can come out as 0. */
6631 else if (TREE_CODE (arg1) == INTEGER_CST
6632 && !integer_zerop (arg1)
6633 && TREE_CONSTANT (arg0)
6634 && TREE_CODE (arg0) == ADDR_EXPR
6636 t1 = build_int_2 (0, 0);
6638 /* Two real constants can be compared explicitly. */
6639 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
6641 /* If either operand is a NaN, the result is false with two
6642 exceptions: First, an NE_EXPR is true on NaNs, but that case
6643 is already handled correctly since we will be inverting the
6644 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6645 or a GE_EXPR into a LT_EXPR, we must return true so that it
6646 will be inverted into false. */
6648 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
6649 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
6650 t1 = build_int_2 (invert && code == LT_EXPR, 0);
6652 else if (code == EQ_EXPR)
6653 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
6654 TREE_REAL_CST (arg1)),
6657 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
6658 TREE_REAL_CST (arg1)),
6662 if (t1 == NULL_TREE)
6666 TREE_INT_CST_LOW (t1) ^= 1;
6668 TREE_TYPE (t1) = type;
6669 if (TREE_CODE (type) == BOOLEAN_TYPE)
6670 return truthvalue_conversion (t1);
6674 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
6675 so all simple results must be passed through pedantic_non_lvalue. */
6676 if (TREE_CODE (arg0) == INTEGER_CST)
6677 return pedantic_non_lvalue
6678 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
6679 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
6680 return pedantic_omit_one_operand (type, arg1, arg0);
6682 /* If the second operand is zero, invert the comparison and swap
6683 the second and third operands. Likewise if the second operand
6684 is constant and the third is not or if the third operand is
6685 equivalent to the first operand of the comparison. */
6687 if (integer_zerop (arg1)
6688 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
6689 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6690 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6691 TREE_OPERAND (t, 2),
6692 TREE_OPERAND (arg0, 1))))
6694 /* See if this can be inverted. If it can't, possibly because
6695 it was a floating-point inequality comparison, don't do
6697 tem = invert_truthvalue (arg0);
6699 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6701 t = build (code, type, tem,
6702 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6704 /* arg1 should be the first argument of the new T. */
6705 arg1 = TREE_OPERAND (t, 1);
6710 /* If we have A op B ? A : C, we may be able to convert this to a
6711 simpler expression, depending on the operation and the values
6712 of B and C. IEEE floating point prevents this though,
6713 because A or B might be -0.0 or a NaN. */
6715 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6716 && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
6717 || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0)))
6719 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6720 arg1, TREE_OPERAND (arg0, 1)))
6722 tree arg2 = TREE_OPERAND (t, 2);
6723 enum tree_code comp_code = TREE_CODE (arg0);
6727 /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
6728 depending on the comparison operation. */
6729 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
6730 ? real_zerop (TREE_OPERAND (arg0, 1))
6731 : integer_zerop (TREE_OPERAND (arg0, 1)))
6732 && TREE_CODE (arg2) == NEGATE_EXPR
6733 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
6737 return pedantic_non_lvalue (negate_expr (arg1));
6739 return pedantic_non_lvalue (convert (type, arg1));
6742 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6743 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6744 return pedantic_non_lvalue
6745 (convert (type, fold (build1 (ABS_EXPR,
6746 TREE_TYPE (arg1), arg1))));
6749 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6750 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6751 return pedantic_non_lvalue
6752 (negate_expr (convert (type,
6753 fold (build1 (ABS_EXPR,
6760 /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
6763 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
6765 if (comp_code == NE_EXPR)
6766 return pedantic_non_lvalue (convert (type, arg1));
6767 else if (comp_code == EQ_EXPR)
6768 return pedantic_non_lvalue (convert (type, integer_zero_node));
6771 /* If this is A op B ? A : B, this is either A, B, min (A, B),
6772 or max (A, B), depending on the operation. */
6774 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
6775 arg2, TREE_OPERAND (arg0, 0)))
6777 tree comp_op0 = TREE_OPERAND (arg0, 0);
6778 tree comp_op1 = TREE_OPERAND (arg0, 1);
6779 tree comp_type = TREE_TYPE (comp_op0);
6784 return pedantic_non_lvalue (convert (type, arg2));
6786 return pedantic_non_lvalue (convert (type, arg1));
6789 /* In C++ a ?: expression can be an lvalue, so put the
6790 operand which will be used if they are equal first
6791 so that we can convert this back to the
6792 corresponding COND_EXPR. */
6793 return pedantic_non_lvalue
6794 (convert (type, (fold (build (MIN_EXPR, comp_type,
6795 (comp_code == LE_EXPR
6796 ? comp_op0 : comp_op1),
6797 (comp_code == LE_EXPR
6798 ? comp_op1 : comp_op0))))));
6802 return pedantic_non_lvalue
6803 (convert (type, fold (build (MAX_EXPR, comp_type,
6804 (comp_code == GE_EXPR
6805 ? comp_op0 : comp_op1),
6806 (comp_code == GE_EXPR
6807 ? comp_op1 : comp_op0)))));
6814 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
6815 we might still be able to simplify this. For example,
6816 if C1 is one less or one more than C2, this might have started
6817 out as a MIN or MAX and been transformed by this function.
6818 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
6820 if (INTEGRAL_TYPE_P (type)
6821 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6822 && TREE_CODE (arg2) == INTEGER_CST)
6826 /* We can replace A with C1 in this case. */
6827 arg1 = convert (type, TREE_OPERAND (arg0, 1));
6828 t = build (code, type, TREE_OPERAND (t, 0), arg1,
6829 TREE_OPERAND (t, 2));
6833 /* If C1 is C2 + 1, this is min(A, C2). */
6834 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6835 && operand_equal_p (TREE_OPERAND (arg0, 1),
6836 const_binop (PLUS_EXPR, arg2,
6837 integer_one_node, 0), 1))
6838 return pedantic_non_lvalue
6839 (fold (build (MIN_EXPR, type, arg1, arg2)));
6843 /* If C1 is C2 - 1, this is min(A, C2). */
6844 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6845 && operand_equal_p (TREE_OPERAND (arg0, 1),
6846 const_binop (MINUS_EXPR, arg2,
6847 integer_one_node, 0), 1))
6848 return pedantic_non_lvalue
6849 (fold (build (MIN_EXPR, type, arg1, arg2)));
6853 /* If C1 is C2 - 1, this is max(A, C2). */
6854 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6855 && operand_equal_p (TREE_OPERAND (arg0, 1),
6856 const_binop (MINUS_EXPR, arg2,
6857 integer_one_node, 0), 1))
6858 return pedantic_non_lvalue
6859 (fold (build (MAX_EXPR, type, arg1, arg2)));
6863 /* If C1 is C2 + 1, this is max(A, C2). */
6864 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6865 && operand_equal_p (TREE_OPERAND (arg0, 1),
6866 const_binop (PLUS_EXPR, arg2,
6867 integer_one_node, 0), 1))
6868 return pedantic_non_lvalue
6869 (fold (build (MAX_EXPR, type, arg1, arg2)));
6878 /* If the second operand is simpler than the third, swap them
6879 since that produces better jump optimization results. */
6880 if ((TREE_CONSTANT (arg1) || TREE_CODE_CLASS (TREE_CODE (arg1)) == 'd'
6881 || TREE_CODE (arg1) == SAVE_EXPR)
6882 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
6883 || TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (t, 2))) == 'd'
6884 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
6886 /* See if this can be inverted. If it can't, possibly because
6887 it was a floating-point inequality comparison, don't do
6889 tem = invert_truthvalue (arg0);
6891 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6893 t = build (code, type, tem,
6894 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6896 /* arg1 should be the first argument of the new T. */
6897 arg1 = TREE_OPERAND (t, 1);
6902 /* Convert A ? 1 : 0 to simply A. */
6903 if (integer_onep (TREE_OPERAND (t, 1))
6904 && integer_zerop (TREE_OPERAND (t, 2))
6905 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
6906 call to fold will try to move the conversion inside
6907 a COND, which will recurse. In that case, the COND_EXPR
6908 is probably the best choice, so leave it alone. */
6909 && type == TREE_TYPE (arg0))
6910 return pedantic_non_lvalue (arg0);
6912 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
6913 operation is simply A & 2. */
6915 if (integer_zerop (TREE_OPERAND (t, 2))
6916 && TREE_CODE (arg0) == NE_EXPR
6917 && integer_zerop (TREE_OPERAND (arg0, 1))
6918 && integer_pow2p (arg1)
6919 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
6920 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
6922 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
6927 /* When pedantic, a compound expression can be neither an lvalue
6928 nor an integer constant expression. */
6929 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
6931 /* Don't let (0, 0) be null pointer constant. */
6932 if (integer_zerop (arg1))
6933 return build1 (NOP_EXPR, TREE_TYPE (arg1), arg1);
6938 return build_complex (type, arg0, arg1);
6942 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6944 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6945 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
6946 TREE_OPERAND (arg0, 1));
6947 else if (TREE_CODE (arg0) == COMPLEX_CST)
6948 return TREE_REALPART (arg0);
6949 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6950 return fold (build (TREE_CODE (arg0), type,
6951 fold (build1 (REALPART_EXPR, type,
6952 TREE_OPERAND (arg0, 0))),
6953 fold (build1 (REALPART_EXPR,
6954 type, TREE_OPERAND (arg0, 1)))));
6958 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6959 return convert (type, integer_zero_node);
6960 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6961 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
6962 TREE_OPERAND (arg0, 0));
6963 else if (TREE_CODE (arg0) == COMPLEX_CST)
6964 return TREE_IMAGPART (arg0);
6965 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6966 return fold (build (TREE_CODE (arg0), type,
6967 fold (build1 (IMAGPART_EXPR, type,
6968 TREE_OPERAND (arg0, 0))),
6969 fold (build1 (IMAGPART_EXPR, type,
6970 TREE_OPERAND (arg0, 1)))));
6973 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
6975 case CLEANUP_POINT_EXPR:
6976 if (! has_cleanups (arg0))
6977 return TREE_OPERAND (t, 0);
6980 enum tree_code code0 = TREE_CODE (arg0);
6981 int kind0 = TREE_CODE_CLASS (code0);
6982 tree arg00 = TREE_OPERAND (arg0, 0);
6985 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
6986 return fold (build1 (code0, type,
6987 fold (build1 (CLEANUP_POINT_EXPR,
6988 TREE_TYPE (arg00), arg00))));
6990 if (kind0 == '<' || kind0 == '2'
6991 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
6992 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
6993 || code0 == TRUTH_XOR_EXPR)
6995 arg01 = TREE_OPERAND (arg0, 1);
6997 if (TREE_CONSTANT (arg00)
6998 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
6999 && ! has_cleanups (arg00)))
7000 return fold (build (code0, type, arg00,
7001 fold (build1 (CLEANUP_POINT_EXPR,
7002 TREE_TYPE (arg01), arg01))));
7004 if (TREE_CONSTANT (arg01))
7005 return fold (build (code0, type,
7006 fold (build1 (CLEANUP_POINT_EXPR,
7007 TREE_TYPE (arg00), arg00)),
7016 } /* switch (code) */
7019 /* Determine if first argument is a multiple of second argument. Return 0 if
7020 it is not, or we cannot easily determined it to be.
7022 An example of the sort of thing we care about (at this point; this routine
7023 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7024 fold cases do now) is discovering that
7026 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7032 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7034 This code also handles discovering that
7036 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7038 is a multiple of 8 so we don't have to worry about dealing with a
7041 Note that we *look* inside a SAVE_EXPR only to determine how it was
7042 calculated; it is not safe for fold to do much of anything else with the
7043 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7044 at run time. For example, the latter example above *cannot* be implemented
7045 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7046 evaluation time of the original SAVE_EXPR is not necessarily the same at
7047 the time the new expression is evaluated. The only optimization of this
7048 sort that would be valid is changing
7050 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7054 SAVE_EXPR (I) * SAVE_EXPR (J)
7056 (where the same SAVE_EXPR (J) is used in the original and the
7057 transformed version). */
7060 multiple_of_p (type, top, bottom)
7065 if (operand_equal_p (top, bottom, 0))
7068 if (TREE_CODE (type) != INTEGER_TYPE)
7071 switch (TREE_CODE (top))
7074 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7075 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7079 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7080 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7083 /* Can't handle conversions from non-integral or wider integral type. */
7084 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
7085 || (TYPE_PRECISION (type)
7086 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
7089 /* .. fall through ... */
7092 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
7095 if ((TREE_CODE (bottom) != INTEGER_CST)
7096 || (tree_int_cst_sgn (top) < 0)
7097 || (tree_int_cst_sgn (bottom) < 0))
7099 return integer_zerop (const_binop (TRUNC_MOD_EXPR,