1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 88, 92-98, 1999 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. */
54 static void encode PROTO((HOST_WIDE_INT *,
55 HOST_WIDE_INT, HOST_WIDE_INT));
56 static void decode PROTO((HOST_WIDE_INT *,
57 HOST_WIDE_INT *, HOST_WIDE_INT *));
58 int div_and_round_double PROTO((enum tree_code, int, HOST_WIDE_INT,
59 HOST_WIDE_INT, HOST_WIDE_INT,
60 HOST_WIDE_INT, HOST_WIDE_INT *,
61 HOST_WIDE_INT *, HOST_WIDE_INT *,
63 static int split_tree PROTO((tree, enum tree_code, tree *,
65 static tree int_const_binop PROTO((enum tree_code, tree, tree, int, int));
66 static tree const_binop PROTO((enum tree_code, tree, tree, int));
67 static tree fold_convert PROTO((tree, tree));
68 static enum tree_code invert_tree_comparison PROTO((enum tree_code));
69 static enum tree_code swap_tree_comparison PROTO((enum tree_code));
70 static int truth_value_p PROTO((enum tree_code));
71 static int operand_equal_for_comparison_p PROTO((tree, tree, tree));
72 static int twoval_comparison_p PROTO((tree, tree *, tree *, int *));
73 static tree eval_subst PROTO((tree, tree, tree, tree, tree));
74 static tree omit_one_operand PROTO((tree, tree, tree));
75 static tree pedantic_omit_one_operand PROTO((tree, tree, tree));
76 static tree distribute_bit_expr PROTO((enum tree_code, tree, tree, tree));
77 static tree make_bit_field_ref PROTO((tree, tree, int, int, int));
78 static tree optimize_bit_field_compare PROTO((enum tree_code, tree,
80 static tree decode_field_reference PROTO((tree, int *, int *,
81 enum machine_mode *, int *,
82 int *, tree *, tree *));
83 static int all_ones_mask_p PROTO((tree, int));
84 static int simple_operand_p PROTO((tree));
85 static tree range_binop PROTO((enum tree_code, tree, tree, int,
87 static tree make_range PROTO((tree, int *, tree *, tree *));
88 static tree build_range_check PROTO((tree, tree, int, tree, tree));
89 static int merge_ranges PROTO((int *, tree *, tree *, int, tree, tree,
91 static tree fold_range_test PROTO((tree));
92 static tree unextend PROTO((tree, int, int, tree));
93 static tree fold_truthop PROTO((enum tree_code, tree, tree, tree));
94 static tree strip_compound_expr PROTO((tree, tree));
95 static int multiple_of_p PROTO((tree, tree, tree));
96 static tree constant_boolean_node PROTO((int, tree));
97 static int count_cond PROTO((tree, int));
98 static void const_binop_1 PROTO((PTR));
99 static void fold_convert_1 PROTO((PTR));
102 #define BRANCH_COST 1
105 /* Suppose A1 + B1 = SUM1, using 2's complement arithmetic ignoring overflow.
106 Suppose A, B and SUM have the same respective signs as A1, B1, and SUM1.
107 Then this yields nonzero if overflow occurred during the addition.
108 Overflow occurs if A and B have the same sign, but A and SUM differ in sign.
109 Use `^' to test whether signs differ, and `< 0' to isolate the sign. */
110 #define overflow_sum_sign(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
112 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
113 We do that by representing the two-word integer in 4 words, with only
114 HOST_BITS_PER_WIDE_INT/2 bits stored in each word, as a positive number. */
117 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT/2)) - 1))
118 #define HIGHPART(x) \
119 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT/2)
120 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT/2)
122 /* Unpack a two-word integer into 4 words.
123 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
124 WORDS points to the array of HOST_WIDE_INTs. */
127 encode (words, low, hi)
128 HOST_WIDE_INT *words;
129 HOST_WIDE_INT low, hi;
131 words[0] = LOWPART (low);
132 words[1] = HIGHPART (low);
133 words[2] = LOWPART (hi);
134 words[3] = HIGHPART (hi);
137 /* Pack an array of 4 words into a two-word integer.
138 WORDS points to the array of words.
139 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
142 decode (words, low, hi)
143 HOST_WIDE_INT *words;
144 HOST_WIDE_INT *low, *hi;
146 *low = words[0] | words[1] * BASE;
147 *hi = words[2] | words[3] * BASE;
150 /* Make the integer constant T valid for its type
151 by setting to 0 or 1 all the bits in the constant
152 that don't belong in the type.
153 Yield 1 if a signed overflow occurs, 0 otherwise.
154 If OVERFLOW is nonzero, a signed overflow has already occurred
155 in calculating T, so propagate it.
157 Make the real constant T valid for its type by calling CHECK_FLOAT_VALUE,
161 force_fit_type (t, overflow)
165 HOST_WIDE_INT low, high;
168 if (TREE_CODE (t) == REAL_CST)
170 #ifdef CHECK_FLOAT_VALUE
171 CHECK_FLOAT_VALUE (TYPE_MODE (TREE_TYPE (t)), TREE_REAL_CST (t),
177 else if (TREE_CODE (t) != INTEGER_CST)
180 low = TREE_INT_CST_LOW (t);
181 high = TREE_INT_CST_HIGH (t);
183 if (POINTER_TYPE_P (TREE_TYPE (t)))
186 prec = TYPE_PRECISION (TREE_TYPE (t));
188 /* First clear all bits that are beyond the type's precision. */
190 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
192 else if (prec > HOST_BITS_PER_WIDE_INT)
194 TREE_INT_CST_HIGH (t)
195 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
199 TREE_INT_CST_HIGH (t) = 0;
200 if (prec < HOST_BITS_PER_WIDE_INT)
201 TREE_INT_CST_LOW (t) &= ~((HOST_WIDE_INT) (-1) << prec);
204 /* Unsigned types do not suffer sign extension or overflow. */
205 if (TREE_UNSIGNED (TREE_TYPE (t)))
208 /* If the value's sign bit is set, extend the sign. */
209 if (prec != 2 * HOST_BITS_PER_WIDE_INT
210 && (prec > HOST_BITS_PER_WIDE_INT
211 ? (TREE_INT_CST_HIGH (t)
212 & ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
213 : TREE_INT_CST_LOW (t) & ((HOST_WIDE_INT) 1 << (prec - 1))))
215 /* Value is negative:
216 set to 1 all the bits that are outside this type's precision. */
217 if (prec > HOST_BITS_PER_WIDE_INT)
219 TREE_INT_CST_HIGH (t)
220 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
224 TREE_INT_CST_HIGH (t) = -1;
225 if (prec < HOST_BITS_PER_WIDE_INT)
226 TREE_INT_CST_LOW (t) |= ((HOST_WIDE_INT) (-1) << prec);
230 /* Yield nonzero if signed overflow occurred. */
232 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
236 /* Add two doubleword integers with doubleword result.
237 Each argument is given as two `HOST_WIDE_INT' pieces.
238 One argument is L1 and H1; the other, L2 and H2.
239 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
242 add_double (l1, h1, l2, h2, lv, hv)
243 HOST_WIDE_INT l1, h1, l2, h2;
244 HOST_WIDE_INT *lv, *hv;
249 h = h1 + h2 + ((unsigned HOST_WIDE_INT) l < l1);
253 return overflow_sum_sign (h1, h2, h);
256 /* Negate a doubleword integer with doubleword result.
257 Return nonzero if the operation overflows, assuming it's signed.
258 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
259 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
262 neg_double (l1, h1, lv, hv)
263 HOST_WIDE_INT l1, h1;
264 HOST_WIDE_INT *lv, *hv;
270 return (*hv & h1) < 0;
280 /* Multiply two doubleword integers with doubleword result.
281 Return nonzero if the operation overflows, assuming it's signed.
282 Each argument is given as two `HOST_WIDE_INT' pieces.
283 One argument is L1 and H1; the other, L2 and H2.
284 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
287 mul_double (l1, h1, l2, h2, lv, hv)
288 HOST_WIDE_INT l1, h1, l2, h2;
289 HOST_WIDE_INT *lv, *hv;
291 HOST_WIDE_INT arg1[4];
292 HOST_WIDE_INT arg2[4];
293 HOST_WIDE_INT prod[4 * 2];
294 register unsigned HOST_WIDE_INT carry;
295 register int i, j, k;
296 HOST_WIDE_INT toplow, tophigh, neglow, neghigh;
298 encode (arg1, l1, h1);
299 encode (arg2, l2, h2);
301 bzero ((char *) prod, sizeof prod);
303 for (i = 0; i < 4; i++)
306 for (j = 0; j < 4; j++)
309 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
310 carry += arg1[i] * arg2[j];
311 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
313 prod[k] = LOWPART (carry);
314 carry = HIGHPART (carry);
319 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
321 /* Check for overflow by calculating the top half of the answer in full;
322 it should agree with the low half's sign bit. */
323 decode (prod+4, &toplow, &tophigh);
326 neg_double (l2, h2, &neglow, &neghigh);
327 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
331 neg_double (l1, h1, &neglow, &neghigh);
332 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
334 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
337 /* Shift the doubleword integer in L1, H1 left by COUNT places
338 keeping only PREC bits of result.
339 Shift right if COUNT is negative.
340 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
341 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
344 lshift_double (l1, h1, count, prec, lv, hv, arith)
345 HOST_WIDE_INT l1, h1, count;
347 HOST_WIDE_INT *lv, *hv;
352 rshift_double (l1, h1, - count, prec, lv, hv, arith);
356 #ifdef SHIFT_COUNT_TRUNCATED
357 if (SHIFT_COUNT_TRUNCATED)
361 if (count >= HOST_BITS_PER_WIDE_INT)
363 *hv = (unsigned HOST_WIDE_INT) l1 << (count - HOST_BITS_PER_WIDE_INT);
368 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
369 | ((unsigned HOST_WIDE_INT) l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
370 *lv = (unsigned HOST_WIDE_INT) l1 << count;
374 /* Shift the doubleword integer in L1, H1 right by COUNT places
375 keeping only PREC bits of result. COUNT must be positive.
376 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
377 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
380 rshift_double (l1, h1, count, prec, lv, hv, arith)
381 HOST_WIDE_INT l1, h1, count;
382 int prec ATTRIBUTE_UNUSED;
383 HOST_WIDE_INT *lv, *hv;
386 unsigned HOST_WIDE_INT signmask;
388 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
391 #ifdef SHIFT_COUNT_TRUNCATED
392 if (SHIFT_COUNT_TRUNCATED)
396 if (count >= HOST_BITS_PER_WIDE_INT)
399 *lv = ((signmask << (2 * HOST_BITS_PER_WIDE_INT - count - 1) << 1)
400 | ((unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT)));
404 *lv = (((unsigned HOST_WIDE_INT) l1 >> count)
405 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
406 *hv = ((signmask << (HOST_BITS_PER_WIDE_INT - count))
407 | ((unsigned HOST_WIDE_INT) h1 >> count));
411 /* Rotate the doubleword integer in L1, H1 left by COUNT places
412 keeping only PREC bits of result.
413 Rotate right if COUNT is negative.
414 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
417 lrotate_double (l1, h1, count, prec, lv, hv)
418 HOST_WIDE_INT l1, h1, count;
420 HOST_WIDE_INT *lv, *hv;
422 HOST_WIDE_INT s1l, s1h, s2l, s2h;
428 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
429 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
434 /* Rotate the doubleword integer in L1, H1 left by COUNT places
435 keeping only PREC bits of result. COUNT must be positive.
436 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
439 rrotate_double (l1, h1, count, prec, lv, hv)
440 HOST_WIDE_INT l1, h1, count;
442 HOST_WIDE_INT *lv, *hv;
444 HOST_WIDE_INT s1l, s1h, s2l, s2h;
450 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
451 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
456 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
457 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
458 CODE is a tree code for a kind of division, one of
459 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
461 It controls how the quotient is rounded to a integer.
462 Return nonzero if the operation overflows.
463 UNS nonzero says do unsigned division. */
466 div_and_round_double (code, uns,
467 lnum_orig, hnum_orig, lden_orig, hden_orig,
468 lquo, hquo, lrem, hrem)
471 HOST_WIDE_INT lnum_orig, hnum_orig; /* num == numerator == dividend */
472 HOST_WIDE_INT lden_orig, hden_orig; /* den == denominator == divisor */
473 HOST_WIDE_INT *lquo, *hquo, *lrem, *hrem;
476 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
477 HOST_WIDE_INT den[4], quo[4];
479 unsigned HOST_WIDE_INT work;
480 register unsigned HOST_WIDE_INT carry = 0;
481 HOST_WIDE_INT lnum = lnum_orig;
482 HOST_WIDE_INT hnum = hnum_orig;
483 HOST_WIDE_INT lden = lden_orig;
484 HOST_WIDE_INT hden = hden_orig;
487 if ((hden == 0) && (lden == 0))
488 overflow = 1, lden = 1;
490 /* calculate quotient sign and convert operands to unsigned. */
496 /* (minimum integer) / (-1) is the only overflow case. */
497 if (neg_double (lnum, hnum, &lnum, &hnum) && (lden & hden) == -1)
503 neg_double (lden, hden, &lden, &hden);
507 if (hnum == 0 && hden == 0)
508 { /* single precision */
510 /* This unsigned division rounds toward zero. */
511 *lquo = lnum / (unsigned HOST_WIDE_INT) lden;
516 { /* trivial case: dividend < divisor */
517 /* hden != 0 already checked. */
524 bzero ((char *) quo, sizeof quo);
526 bzero ((char *) num, sizeof num); /* to zero 9th element */
527 bzero ((char *) den, sizeof den);
529 encode (num, lnum, hnum);
530 encode (den, lden, hden);
532 /* Special code for when the divisor < BASE. */
533 if (hden == 0 && lden < (HOST_WIDE_INT) BASE)
535 /* hnum != 0 already checked. */
536 for (i = 4 - 1; i >= 0; i--)
538 work = num[i] + carry * BASE;
539 quo[i] = work / (unsigned HOST_WIDE_INT) lden;
540 carry = work % (unsigned HOST_WIDE_INT) lden;
545 /* Full double precision division,
546 with thanks to Don Knuth's "Seminumerical Algorithms". */
547 int num_hi_sig, den_hi_sig;
548 unsigned HOST_WIDE_INT quo_est, scale;
550 /* Find the highest non-zero divisor digit. */
551 for (i = 4 - 1; ; i--)
557 /* Insure that the first digit of the divisor is at least BASE/2.
558 This is required by the quotient digit estimation algorithm. */
560 scale = BASE / (den[den_hi_sig] + 1);
561 if (scale > 1) { /* scale divisor and dividend */
563 for (i = 0; i <= 4 - 1; i++) {
564 work = (num[i] * scale) + carry;
565 num[i] = LOWPART (work);
566 carry = HIGHPART (work);
569 for (i = 0; i <= 4 - 1; i++) {
570 work = (den[i] * scale) + carry;
571 den[i] = LOWPART (work);
572 carry = HIGHPART (work);
573 if (den[i] != 0) den_hi_sig = i;
580 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--) {
581 /* guess the next quotient digit, quo_est, by dividing the first
582 two remaining dividend digits by the high order quotient digit.
583 quo_est is never low and is at most 2 high. */
584 unsigned HOST_WIDE_INT tmp;
586 num_hi_sig = i + den_hi_sig + 1;
587 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
588 if (num[num_hi_sig] != den[den_hi_sig])
589 quo_est = work / den[den_hi_sig];
593 /* refine quo_est so it's usually correct, and at most one high. */
594 tmp = work - quo_est * den[den_hi_sig];
596 && den[den_hi_sig - 1] * quo_est > (tmp * BASE + num[num_hi_sig - 2]))
599 /* Try QUO_EST as the quotient digit, by multiplying the
600 divisor by QUO_EST and subtracting from the remaining dividend.
601 Keep in mind that QUO_EST is the I - 1st digit. */
604 for (j = 0; j <= den_hi_sig; j++)
606 work = quo_est * den[j] + carry;
607 carry = HIGHPART (work);
608 work = num[i + j] - LOWPART (work);
609 num[i + j] = LOWPART (work);
610 carry += HIGHPART (work) != 0;
613 /* if quo_est was high by one, then num[i] went negative and
614 we need to correct things. */
616 if (num[num_hi_sig] < carry)
619 carry = 0; /* add divisor back in */
620 for (j = 0; j <= den_hi_sig; j++)
622 work = num[i + j] + den[j] + carry;
623 carry = HIGHPART (work);
624 num[i + j] = LOWPART (work);
626 num [num_hi_sig] += carry;
629 /* store the quotient digit. */
634 decode (quo, lquo, hquo);
637 /* if result is negative, make it so. */
639 neg_double (*lquo, *hquo, lquo, hquo);
641 /* compute trial remainder: rem = num - (quo * den) */
642 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
643 neg_double (*lrem, *hrem, lrem, hrem);
644 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
649 case TRUNC_MOD_EXPR: /* round toward zero */
650 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
654 case FLOOR_MOD_EXPR: /* round toward negative infinity */
655 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
658 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
661 else return overflow;
665 case CEIL_MOD_EXPR: /* round toward positive infinity */
666 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
668 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
671 else return overflow;
675 case ROUND_MOD_EXPR: /* round to closest integer */
677 HOST_WIDE_INT labs_rem = *lrem, habs_rem = *hrem;
678 HOST_WIDE_INT labs_den = lden, habs_den = hden, ltwice, htwice;
680 /* get absolute values */
681 if (*hrem < 0) neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
682 if (hden < 0) neg_double (lden, hden, &labs_den, &habs_den);
684 /* if (2 * abs (lrem) >= abs (lden)) */
685 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
686 labs_rem, habs_rem, <wice, &htwice);
687 if (((unsigned HOST_WIDE_INT) habs_den
688 < (unsigned HOST_WIDE_INT) htwice)
689 || (((unsigned HOST_WIDE_INT) habs_den
690 == (unsigned HOST_WIDE_INT) htwice)
691 && ((HOST_WIDE_INT unsigned) labs_den
692 < (unsigned HOST_WIDE_INT) ltwice)))
696 add_double (*lquo, *hquo,
697 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
700 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
703 else return overflow;
711 /* compute true remainder: rem = num - (quo * den) */
712 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
713 neg_double (*lrem, *hrem, lrem, hrem);
714 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
718 #ifndef REAL_ARITHMETIC
719 /* Effectively truncate a real value to represent the nearest possible value
720 in a narrower mode. The result is actually represented in the same data
721 type as the argument, but its value is usually different.
723 A trap may occur during the FP operations and it is the responsibility
724 of the calling function to have a handler established. */
727 real_value_truncate (mode, arg)
728 enum machine_mode mode;
731 return REAL_VALUE_TRUNCATE (mode, arg);
734 #if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
736 /* Check for infinity in an IEEE double precision number. */
742 /* The IEEE 64-bit double format. */
747 unsigned exponent : 11;
748 unsigned mantissa1 : 20;
753 unsigned mantissa1 : 20;
754 unsigned exponent : 11;
760 if (u.big_endian.sign == 1)
763 return (u.big_endian.exponent == 2047
764 && u.big_endian.mantissa1 == 0
765 && u.big_endian.mantissa2 == 0);
770 return (u.little_endian.exponent == 2047
771 && u.little_endian.mantissa1 == 0
772 && u.little_endian.mantissa2 == 0);
776 /* Check whether an IEEE double precision number is a NaN. */
782 /* The IEEE 64-bit double format. */
787 unsigned exponent : 11;
788 unsigned mantissa1 : 20;
793 unsigned mantissa1 : 20;
794 unsigned exponent : 11;
800 if (u.big_endian.sign == 1)
803 return (u.big_endian.exponent == 2047
804 && (u.big_endian.mantissa1 != 0
805 || u.big_endian.mantissa2 != 0));
810 return (u.little_endian.exponent == 2047
811 && (u.little_endian.mantissa1 != 0
812 || u.little_endian.mantissa2 != 0));
816 /* Check for a negative IEEE double precision number. */
822 /* The IEEE 64-bit double format. */
827 unsigned exponent : 11;
828 unsigned mantissa1 : 20;
833 unsigned mantissa1 : 20;
834 unsigned exponent : 11;
840 if (u.big_endian.sign == 1)
843 return u.big_endian.sign;
848 return u.little_endian.sign;
851 #else /* Target not IEEE */
853 /* Let's assume other float formats don't have infinity.
854 (This can be overridden by redefining REAL_VALUE_ISINF.) */
862 /* Let's assume other float formats don't have NaNs.
863 (This can be overridden by redefining REAL_VALUE_ISNAN.) */
871 /* Let's assume other float formats don't have minus zero.
872 (This can be overridden by redefining REAL_VALUE_NEGATIVE.) */
879 #endif /* Target not IEEE */
881 /* Try to change R into its exact multiplicative inverse in machine mode
882 MODE. Return nonzero function value if successful. */
885 exact_real_inverse (mode, r)
886 enum machine_mode mode;
897 /* Usually disable if bounds checks are not reliable. */
898 if ((HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT) && !flag_pretend_float)
901 /* Set array index to the less significant bits in the unions, depending
902 on the endian-ness of the host doubles.
903 Disable if insufficient information on the data structure. */
904 #if HOST_FLOAT_FORMAT == UNKNOWN_FLOAT_FORMAT
907 #if HOST_FLOAT_FORMAT == VAX_FLOAT_FORMAT
910 #if HOST_FLOAT_FORMAT == IBM_FLOAT_FORMAT
913 #define K (2 * HOST_FLOAT_WORDS_BIG_ENDIAN)
918 if (setjmp (float_error))
920 /* Don't do the optimization if there was an arithmetic error. */
922 set_float_handler (NULL_PTR);
925 set_float_handler (float_error);
927 /* Domain check the argument. */
933 if (REAL_VALUE_ISINF (x.d) || REAL_VALUE_ISNAN (x.d))
937 /* Compute the reciprocal and check for numerical exactness.
938 It is unnecessary to check all the significand bits to determine
939 whether X is a power of 2. If X is not, then it is impossible for
940 the bottom half significand of both X and 1/X to be all zero bits.
941 Hence we ignore the data structure of the top half and examine only
942 the low order bits of the two significands. */
944 if (x.i[K] != 0 || x.i[K + 1] != 0 || t.i[K] != 0 || t.i[K + 1] != 0)
947 /* Truncate to the required mode and range-check the result. */
948 y.d = REAL_VALUE_TRUNCATE (mode, t.d);
949 #ifdef CHECK_FLOAT_VALUE
951 if (CHECK_FLOAT_VALUE (mode, y.d, i))
955 /* Fail if truncation changed the value. */
956 if (y.d != t.d || y.d == 0.0)
960 if (REAL_VALUE_ISINF (y.d) || REAL_VALUE_ISNAN (y.d))
964 /* Output the reciprocal and return success flag. */
965 set_float_handler (NULL_PTR);
971 /* Convert C9X hexadecimal floating point string constant S. Return
972 real value type in mode MODE. This function uses the host computer's
973 fp arithmetic when there is no REAL_ARITHMETIC. */
976 real_hex_to_f (s, mode)
978 enum machine_mode mode;
982 unsigned HOST_WIDE_INT low, high;
983 int frexpon, expon, shcount, nrmcount, k;
984 int sign, expsign, decpt, isfloat, isldouble, gotp, lost;
994 while (*p == ' ' || *p == '\t')
997 /* Sign, if any, comes first. */
1005 /* The string is supposed to start with 0x or 0X . */
1009 if (*p == 'x' || *p == 'X')
1022 lost = 0; /* Nonzero low order bits shifted out and discarded. */
1023 frexpon = 0; /* Bits after the decimal point. */
1024 expon = 0; /* Value of exponent. */
1025 decpt = 0; /* How many decimal points. */
1026 gotp = 0; /* How many P's. */
1028 while ((c = *p) != '\0')
1030 if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F')
1031 || (c >= 'a' && c <= 'f'))
1041 if ((high & 0xf0000000) == 0)
1043 high = (high << 4) + ((low >> 28) & 15);
1044 low = (low << 4) + k;
1051 /* Record nonzero lost bits. */
1063 else if (c == 'p' || c == 'P')
1067 /* Sign of exponent. */
1073 /* Value of exponent.
1074 The exponent field is a decimal integer. */
1077 k = (*p++ & 0x7f) - '0';
1078 expon = 10 * expon + k;
1081 /* F suffix is ambiguous in the significand part
1082 so it must appear after the decimal exponent field. */
1083 if (*p == 'f' || *p == 'F')
1090 else if (c == 'l' || c == 'L')
1099 /* Abort if last character read was not legitimate. */
1101 if ((c != '\0' && c != ' ' && c != '\n' && c != '\r') || (decpt > 1))
1103 /* There must be either one decimal point or one p. */
1104 if (decpt == 0 && gotp == 0)
1107 if ((high == 0) && (low == 0))
1120 /* Leave a high guard bit for carry-out. */
1121 if ((high & 0x80000000) != 0)
1124 low = (low >> 1) | (high << 31);
1128 if ((high & 0xffff8000) == 0)
1130 high = (high << 16) + ((low >> 16) & 0xffff);
1134 while ((high & 0xc0000000) == 0)
1136 high = (high << 1) + ((low >> 31) & 1);
1140 if (isfloat || GET_MODE_SIZE(mode) == UNITS_PER_WORD)
1142 /* Keep 24 bits precision, bits 0x7fffff80.
1143 Rounding bit is 0x40. */
1144 lost = lost | low | (high & 0x3f);
1148 if ((high & 0x80) || lost)
1155 /* We need real.c to do long double formats, so here default
1156 to double precision. */
1157 #if HOST_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
1159 Keep 53 bits precision, bits 0x7fffffff fffffc00.
1160 Rounding bit is low word 0x200. */
1161 lost = lost | (low & 0x1ff);
1164 if ((low & 0x400) || lost)
1166 low = (low + 0x200) & 0xfffffc00;
1173 /* Assume it's a VAX with 56-bit significand,
1174 bits 0x7fffffff ffffff80. */
1175 lost = lost | (low & 0x7f);
1178 if ((low & 0x80) || lost)
1180 low = (low + 0x40) & 0xffffff80;
1189 ip = REAL_VALUE_LDEXP (ip, 32) + (double) low;
1190 /* Apply shifts and exponent value as power of 2. */
1191 ip = REAL_VALUE_LDEXP (ip, expon - (nrmcount + frexpon));
1198 #endif /* no REAL_ARITHMETIC */
1200 /* Split a tree IN into a constant and a variable part
1201 that could be combined with CODE to make IN.
1202 CODE must be a commutative arithmetic operation.
1203 Store the constant part into *CONP and the variable in &VARP.
1204 Return 1 if this was done; zero means the tree IN did not decompose
1207 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR.
1208 Therefore, we must tell the caller whether the variable part
1209 was subtracted. We do this by storing 1 or -1 into *VARSIGNP.
1210 The value stored is the coefficient for the variable term.
1211 The constant term we return should always be added;
1212 we negate it if necessary. */
1215 split_tree (in, code, varp, conp, varsignp)
1217 enum tree_code code;
1221 register tree outtype = TREE_TYPE (in);
1225 /* Strip any conversions that don't change the machine mode. */
1226 while ((TREE_CODE (in) == NOP_EXPR
1227 || TREE_CODE (in) == CONVERT_EXPR)
1228 && (TYPE_MODE (TREE_TYPE (in))
1229 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (in, 0)))))
1230 in = TREE_OPERAND (in, 0);
1232 if (TREE_CODE (in) == code
1233 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1234 /* We can associate addition and subtraction together
1235 (even though the C standard doesn't say so)
1236 for integers because the value is not affected.
1237 For reals, the value might be affected, so we can't. */
1238 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1239 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1241 enum tree_code code = TREE_CODE (TREE_OPERAND (in, 0));
1242 if (code == INTEGER_CST)
1244 *conp = TREE_OPERAND (in, 0);
1245 *varp = TREE_OPERAND (in, 1);
1246 if (TYPE_MODE (TREE_TYPE (*varp)) != TYPE_MODE (outtype)
1247 && TREE_TYPE (*varp) != outtype)
1248 *varp = convert (outtype, *varp);
1249 *varsignp = (TREE_CODE (in) == MINUS_EXPR) ? -1 : 1;
1252 if (TREE_CONSTANT (TREE_OPERAND (in, 1)))
1254 *conp = TREE_OPERAND (in, 1);
1255 *varp = TREE_OPERAND (in, 0);
1257 if (TYPE_MODE (TREE_TYPE (*varp)) != TYPE_MODE (outtype)
1258 && TREE_TYPE (*varp) != outtype)
1259 *varp = convert (outtype, *varp);
1260 if (TREE_CODE (in) == MINUS_EXPR)
1262 /* If operation is subtraction and constant is second,
1263 must negate it to get an additive constant.
1264 And this cannot be done unless it is a manifest constant.
1265 It could also be the address of a static variable.
1266 We cannot negate that, so give up. */
1267 if (TREE_CODE (*conp) == INTEGER_CST)
1268 /* Subtracting from integer_zero_node loses for long long. */
1269 *conp = fold (build1 (NEGATE_EXPR, TREE_TYPE (*conp), *conp));
1275 if (TREE_CONSTANT (TREE_OPERAND (in, 0)))
1277 *conp = TREE_OPERAND (in, 0);
1278 *varp = TREE_OPERAND (in, 1);
1279 if (TYPE_MODE (TREE_TYPE (*varp)) != TYPE_MODE (outtype)
1280 && TREE_TYPE (*varp) != outtype)
1281 *varp = convert (outtype, *varp);
1282 *varsignp = (TREE_CODE (in) == MINUS_EXPR) ? -1 : 1;
1289 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1290 to produce a new constant.
1292 If NOTRUNC is nonzero, do not truncate the result to fit the data type.
1293 If FORSIZE is nonzero, compute overflow for unsigned types. */
1296 int_const_binop (code, arg1, arg2, notrunc, forsize)
1297 enum tree_code code;
1298 register tree arg1, arg2;
1299 int notrunc, forsize;
1301 HOST_WIDE_INT int1l, int1h, int2l, int2h;
1302 HOST_WIDE_INT low, hi;
1303 HOST_WIDE_INT garbagel, garbageh;
1305 int uns = TREE_UNSIGNED (TREE_TYPE (arg1));
1307 int no_overflow = 0;
1309 int1l = TREE_INT_CST_LOW (arg1);
1310 int1h = TREE_INT_CST_HIGH (arg1);
1311 int2l = TREE_INT_CST_LOW (arg2);
1312 int2h = TREE_INT_CST_HIGH (arg2);
1317 low = int1l | int2l, hi = int1h | int2h;
1321 low = int1l ^ int2l, hi = int1h ^ int2h;
1325 low = int1l & int2l, hi = int1h & int2h;
1328 case BIT_ANDTC_EXPR:
1329 low = int1l & ~int2l, hi = int1h & ~int2h;
1335 /* It's unclear from the C standard whether shifts can overflow.
1336 The following code ignores overflow; perhaps a C standard
1337 interpretation ruling is needed. */
1338 lshift_double (int1l, int1h, int2l,
1339 TYPE_PRECISION (TREE_TYPE (arg1)),
1348 lrotate_double (int1l, int1h, int2l,
1349 TYPE_PRECISION (TREE_TYPE (arg1)),
1354 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1358 neg_double (int2l, int2h, &low, &hi);
1359 add_double (int1l, int1h, low, hi, &low, &hi);
1360 overflow = overflow_sum_sign (hi, int2h, int1h);
1364 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1367 case TRUNC_DIV_EXPR:
1368 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1369 case EXACT_DIV_EXPR:
1370 /* This is a shortcut for a common special case. */
1371 if (int2h == 0 && int2l > 0
1372 && ! TREE_CONSTANT_OVERFLOW (arg1)
1373 && ! TREE_CONSTANT_OVERFLOW (arg2)
1374 && int1h == 0 && int1l >= 0)
1376 if (code == CEIL_DIV_EXPR)
1378 low = int1l / int2l, hi = 0;
1382 /* ... fall through ... */
1384 case ROUND_DIV_EXPR:
1385 if (int2h == 0 && int2l == 1)
1387 low = int1l, hi = int1h;
1390 if (int1l == int2l && int1h == int2h
1391 && ! (int1l == 0 && int1h == 0))
1396 overflow = div_and_round_double (code, uns,
1397 int1l, int1h, int2l, int2h,
1398 &low, &hi, &garbagel, &garbageh);
1401 case TRUNC_MOD_EXPR:
1402 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1403 /* This is a shortcut for a common special case. */
1404 if (int2h == 0 && int2l > 0
1405 && ! TREE_CONSTANT_OVERFLOW (arg1)
1406 && ! TREE_CONSTANT_OVERFLOW (arg2)
1407 && int1h == 0 && int1l >= 0)
1409 if (code == CEIL_MOD_EXPR)
1411 low = int1l % int2l, hi = 0;
1415 /* ... fall through ... */
1417 case ROUND_MOD_EXPR:
1418 overflow = div_and_round_double (code, uns,
1419 int1l, int1h, int2l, int2h,
1420 &garbagel, &garbageh, &low, &hi);
1427 low = (((unsigned HOST_WIDE_INT) int1h
1428 < (unsigned HOST_WIDE_INT) int2h)
1429 || (((unsigned HOST_WIDE_INT) int1h
1430 == (unsigned HOST_WIDE_INT) int2h)
1431 && ((unsigned HOST_WIDE_INT) int1l
1432 < (unsigned HOST_WIDE_INT) int2l)));
1436 low = ((int1h < int2h)
1437 || ((int1h == int2h)
1438 && ((unsigned HOST_WIDE_INT) int1l
1439 < (unsigned HOST_WIDE_INT) int2l)));
1441 if (low == (code == MIN_EXPR))
1442 low = int1l, hi = int1h;
1444 low = int2l, hi = int2h;
1451 if (TREE_TYPE (arg1) == sizetype && hi == 0
1453 && (TYPE_MAX_VALUE (sizetype) == NULL
1454 || low <= TREE_INT_CST_LOW (TYPE_MAX_VALUE (sizetype)))
1456 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1460 t = build_int_2 (low, hi);
1461 TREE_TYPE (t) = TREE_TYPE (arg1);
1465 = ((notrunc ? (!uns || forsize) && overflow
1466 : force_fit_type (t, (!uns || forsize) && overflow) && ! no_overflow)
1467 | TREE_OVERFLOW (arg1)
1468 | TREE_OVERFLOW (arg2));
1469 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1470 So check if force_fit_type truncated the value. */
1472 && ! TREE_OVERFLOW (t)
1473 && (TREE_INT_CST_HIGH (t) != hi
1474 || TREE_INT_CST_LOW (t) != low))
1475 TREE_OVERFLOW (t) = 1;
1476 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1477 | TREE_CONSTANT_OVERFLOW (arg1)
1478 | TREE_CONSTANT_OVERFLOW (arg2));
1486 REAL_VALUE_TYPE d1, d2;
1487 enum tree_code code;
1493 const_binop_1 (data)
1496 struct cb_args * args = (struct cb_args *) data;
1497 REAL_VALUE_TYPE value;
1499 #ifdef REAL_ARITHMETIC
1500 REAL_ARITHMETIC (value, args->code, args->d1, args->d2);
1505 value = args->d1 + args->d2;
1509 value = args->d1 - args->d2;
1513 value = args->d1 * args->d2;
1517 #ifndef REAL_INFINITY
1522 value = args->d1 / args->d2;
1526 value = MIN (args->d1, args->d2);
1530 value = MAX (args->d1, args->d2);
1536 #endif /* no REAL_ARITHMETIC */
1538 build_real (TREE_TYPE (args->arg1),
1539 real_value_truncate (TYPE_MODE (TREE_TYPE (args->arg1)),
1543 /* Combine two constants ARG1 and ARG2 under operation CODE
1544 to produce a new constant.
1545 We assume ARG1 and ARG2 have the same data type,
1546 or at least are the same kind of constant and the same machine mode.
1548 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1551 const_binop (code, arg1, arg2, notrunc)
1552 enum tree_code code;
1553 register tree arg1, arg2;
1556 STRIP_NOPS (arg1); STRIP_NOPS (arg2);
1558 if (TREE_CODE (arg1) == INTEGER_CST)
1559 return int_const_binop (code, arg1, arg2, notrunc, 0);
1561 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1562 if (TREE_CODE (arg1) == REAL_CST)
1568 struct cb_args args;
1570 d1 = TREE_REAL_CST (arg1);
1571 d2 = TREE_REAL_CST (arg2);
1573 /* If either operand is a NaN, just return it. Otherwise, set up
1574 for floating-point trap; we return an overflow. */
1575 if (REAL_VALUE_ISNAN (d1))
1577 else if (REAL_VALUE_ISNAN (d2))
1580 /* Setup input for const_binop_1() */
1586 if (do_float_handler (const_binop_1, (PTR) &args))
1588 /* Receive output from const_binop_1() */
1593 /* We got an exception from const_binop_1() */
1594 t = copy_node (arg1);
1599 = (force_fit_type (t, overflow)
1600 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1601 TREE_CONSTANT_OVERFLOW (t)
1603 | TREE_CONSTANT_OVERFLOW (arg1)
1604 | TREE_CONSTANT_OVERFLOW (arg2);
1607 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1608 if (TREE_CODE (arg1) == COMPLEX_CST)
1610 register tree type = TREE_TYPE (arg1);
1611 register tree r1 = TREE_REALPART (arg1);
1612 register tree i1 = TREE_IMAGPART (arg1);
1613 register tree r2 = TREE_REALPART (arg2);
1614 register tree i2 = TREE_IMAGPART (arg2);
1620 t = build_complex (type,
1621 const_binop (PLUS_EXPR, r1, r2, notrunc),
1622 const_binop (PLUS_EXPR, i1, i2, notrunc));
1626 t = build_complex (type,
1627 const_binop (MINUS_EXPR, r1, r2, notrunc),
1628 const_binop (MINUS_EXPR, i1, i2, notrunc));
1632 t = build_complex (type,
1633 const_binop (MINUS_EXPR,
1634 const_binop (MULT_EXPR,
1636 const_binop (MULT_EXPR,
1639 const_binop (PLUS_EXPR,
1640 const_binop (MULT_EXPR,
1642 const_binop (MULT_EXPR,
1649 register tree magsquared
1650 = const_binop (PLUS_EXPR,
1651 const_binop (MULT_EXPR, r2, r2, notrunc),
1652 const_binop (MULT_EXPR, i2, i2, notrunc),
1655 t = build_complex (type,
1657 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1658 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1659 const_binop (PLUS_EXPR,
1660 const_binop (MULT_EXPR, r1, r2,
1662 const_binop (MULT_EXPR, i1, i2,
1665 magsquared, notrunc),
1667 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1668 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1669 const_binop (MINUS_EXPR,
1670 const_binop (MULT_EXPR, i1, r2,
1672 const_binop (MULT_EXPR, r1, i2,
1675 magsquared, notrunc));
1687 /* Return an INTEGER_CST with value V . The type is determined by bit_p:
1688 if it is zero, the type is taken from sizetype; if it is one, the type
1689 is taken from bitsizetype. */
1692 size_int_wide (number, high, bit_p)
1693 unsigned HOST_WIDE_INT number, high;
1700 /* Type-size nodes already made for small sizes. */
1701 static tree size_table[2*HOST_BITS_PER_WIDE_INT + 1][2];
1703 if (number < 2*HOST_BITS_PER_WIDE_INT + 1 && ! high
1704 && size_table[number][bit_p] != 0)
1705 return size_table[number][bit_p];
1706 if (number < 2*HOST_BITS_PER_WIDE_INT + 1 && ! high)
1708 push_obstacks_nochange ();
1709 /* Make this a permanent node. */
1710 end_temporary_allocation ();
1711 t = build_int_2 (number, 0);
1712 TREE_TYPE (t) = bit_p ? bitsizetype : sizetype;
1713 size_table[number][bit_p] = t;
1719 t = build_int_2 (number, high);
1720 TREE_TYPE (t) = bit_p ? bitsizetype : sizetype;
1721 TREE_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (t) = force_fit_type (t, 0);
1725 /* Combine operands OP1 and OP2 with arithmetic operation CODE.
1726 CODE is a tree code. Data type is taken from `sizetype',
1727 If the operands are constant, so is the result. */
1730 size_binop (code, arg0, arg1)
1731 enum tree_code code;
1734 /* Handle the special case of two integer constants faster. */
1735 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1737 /* And some specific cases even faster than that. */
1738 if (code == PLUS_EXPR && integer_zerop (arg0))
1740 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1741 && integer_zerop (arg1))
1743 else if (code == MULT_EXPR && integer_onep (arg0))
1746 /* Handle general case of two integer constants. */
1747 return int_const_binop (code, arg0, arg1, 0, 1);
1750 if (arg0 == error_mark_node || arg1 == error_mark_node)
1751 return error_mark_node;
1753 return fold (build (code, sizetype, arg0, arg1));
1756 /* Combine operands OP1 and OP2 with arithmetic operation CODE.
1757 CODE is a tree code. Data type is taken from `ssizetype',
1758 If the operands are constant, so is the result. */
1761 ssize_binop (code, arg0, arg1)
1762 enum tree_code code;
1765 /* Handle the special case of two integer constants faster. */
1766 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1768 /* And some specific cases even faster than that. */
1769 if (code == PLUS_EXPR && integer_zerop (arg0))
1771 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1772 && integer_zerop (arg1))
1774 else if (code == MULT_EXPR && integer_onep (arg0))
1777 /* Handle general case of two integer constants. We convert
1778 arg0 to ssizetype because int_const_binop uses its type for the
1780 arg0 = convert (ssizetype, arg0);
1781 return int_const_binop (code, arg0, arg1, 0, 0);
1784 if (arg0 == error_mark_node || arg1 == error_mark_node)
1785 return error_mark_node;
1787 return fold (build (code, ssizetype, arg0, arg1));
1799 fold_convert_1 (data)
1802 struct fc_args * args = (struct fc_args *) data;
1804 args->t = build_real (args->type,
1805 real_value_truncate (TYPE_MODE (args->type),
1806 TREE_REAL_CST (args->arg1)));
1809 /* Given T, a tree representing type conversion of ARG1, a constant,
1810 return a constant tree representing the result of conversion. */
1813 fold_convert (t, arg1)
1817 register tree type = TREE_TYPE (t);
1820 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1822 if (TREE_CODE (arg1) == INTEGER_CST)
1824 /* If we would build a constant wider than GCC supports,
1825 leave the conversion unfolded. */
1826 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1829 /* Given an integer constant, make new constant with new type,
1830 appropriately sign-extended or truncated. */
1831 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1832 TREE_INT_CST_HIGH (arg1));
1833 TREE_TYPE (t) = type;
1834 /* Indicate an overflow if (1) ARG1 already overflowed,
1835 or (2) force_fit_type indicates an overflow.
1836 Tell force_fit_type that an overflow has already occurred
1837 if ARG1 is a too-large unsigned value and T is signed.
1838 But don't indicate an overflow if converting a pointer. */
1840 = ((force_fit_type (t,
1841 (TREE_INT_CST_HIGH (arg1) < 0
1842 && (TREE_UNSIGNED (type)
1843 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
1844 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1845 || TREE_OVERFLOW (arg1));
1846 TREE_CONSTANT_OVERFLOW (t)
1847 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1849 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1850 else if (TREE_CODE (arg1) == REAL_CST)
1852 /* Don't initialize these, use assignments.
1853 Initialized local aggregates don't work on old compilers. */
1857 tree type1 = TREE_TYPE (arg1);
1860 x = TREE_REAL_CST (arg1);
1861 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
1863 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
1864 if (!no_upper_bound)
1865 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
1867 /* See if X will be in range after truncation towards 0.
1868 To compensate for truncation, move the bounds away from 0,
1869 but reject if X exactly equals the adjusted bounds. */
1870 #ifdef REAL_ARITHMETIC
1871 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
1872 if (!no_upper_bound)
1873 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
1876 if (!no_upper_bound)
1879 /* If X is a NaN, use zero instead and show we have an overflow.
1880 Otherwise, range check. */
1881 if (REAL_VALUE_ISNAN (x))
1882 overflow = 1, x = dconst0;
1883 else if (! (REAL_VALUES_LESS (l, x)
1885 && REAL_VALUES_LESS (x, u)))
1888 #ifndef REAL_ARITHMETIC
1890 HOST_WIDE_INT low, high;
1891 HOST_WIDE_INT half_word
1892 = (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2);
1897 high = (HOST_WIDE_INT) (x / half_word / half_word);
1898 x -= (REAL_VALUE_TYPE) high * half_word * half_word;
1899 if (x >= (REAL_VALUE_TYPE) half_word * half_word / 2)
1901 low = x - (REAL_VALUE_TYPE) half_word * half_word / 2;
1902 low |= (HOST_WIDE_INT) -1 << (HOST_BITS_PER_WIDE_INT - 1);
1905 low = (HOST_WIDE_INT) x;
1906 if (TREE_REAL_CST (arg1) < 0)
1907 neg_double (low, high, &low, &high);
1908 t = build_int_2 (low, high);
1912 HOST_WIDE_INT low, high;
1913 REAL_VALUE_TO_INT (&low, &high, x);
1914 t = build_int_2 (low, high);
1917 TREE_TYPE (t) = type;
1919 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1920 TREE_CONSTANT_OVERFLOW (t)
1921 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1923 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1924 TREE_TYPE (t) = type;
1926 else if (TREE_CODE (type) == REAL_TYPE)
1928 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1929 if (TREE_CODE (arg1) == INTEGER_CST)
1930 return build_real_from_int_cst (type, arg1);
1931 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1932 if (TREE_CODE (arg1) == REAL_CST)
1934 struct fc_args args;
1936 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1939 TREE_TYPE (arg1) = type;
1943 /* Setup input for fold_convert_1() */
1947 if (do_float_handler (fold_convert_1, (PTR) &args))
1949 /* Receive output from fold_convert_1() */
1954 /* We got an exception from fold_convert_1() */
1956 t = copy_node (arg1);
1960 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1961 TREE_CONSTANT_OVERFLOW (t)
1962 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1966 TREE_CONSTANT (t) = 1;
1970 /* Return an expr equal to X but certainly not valid as an lvalue. */
1978 /* These things are certainly not lvalues. */
1979 if (TREE_CODE (x) == NON_LVALUE_EXPR
1980 || TREE_CODE (x) == INTEGER_CST
1981 || TREE_CODE (x) == REAL_CST
1982 || TREE_CODE (x) == STRING_CST
1983 || TREE_CODE (x) == ADDR_EXPR)
1986 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
1987 TREE_CONSTANT (result) = TREE_CONSTANT (x);
1991 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1992 Zero means allow extended lvalues. */
1994 int pedantic_lvalues;
1996 /* When pedantic, return an expr equal to X but certainly not valid as a
1997 pedantic lvalue. Otherwise, return X. */
2000 pedantic_non_lvalue (x)
2003 if (pedantic_lvalues)
2004 return non_lvalue (x);
2009 /* Given a tree comparison code, return the code that is the logical inverse
2010 of the given code. It is not safe to do this for floating-point
2011 comparisons, except for NE_EXPR and EQ_EXPR. */
2013 static enum tree_code
2014 invert_tree_comparison (code)
2015 enum tree_code code;
2036 /* Similar, but return the comparison that results if the operands are
2037 swapped. This is safe for floating-point. */
2039 static enum tree_code
2040 swap_tree_comparison (code)
2041 enum tree_code code;
2061 /* Return nonzero if CODE is a tree code that represents a truth value. */
2064 truth_value_p (code)
2065 enum tree_code code;
2067 return (TREE_CODE_CLASS (code) == '<'
2068 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2069 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2070 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2073 /* Return nonzero if two operands are necessarily equal.
2074 If ONLY_CONST is non-zero, only return non-zero for constants.
2075 This function tests whether the operands are indistinguishable;
2076 it does not test whether they are equal using C's == operation.
2077 The distinction is important for IEEE floating point, because
2078 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2079 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
2082 operand_equal_p (arg0, arg1, only_const)
2086 /* If both types don't have the same signedness, then we can't consider
2087 them equal. We must check this before the STRIP_NOPS calls
2088 because they may change the signedness of the arguments. */
2089 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
2095 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2096 /* This is needed for conversions and for COMPONENT_REF.
2097 Might as well play it safe and always test this. */
2098 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2099 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2100 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2103 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2104 We don't care about side effects in that case because the SAVE_EXPR
2105 takes care of that for us. In all other cases, two expressions are
2106 equal if they have no side effects. If we have two identical
2107 expressions with side effects that should be treated the same due
2108 to the only side effects being identical SAVE_EXPR's, that will
2109 be detected in the recursive calls below. */
2110 if (arg0 == arg1 && ! only_const
2111 && (TREE_CODE (arg0) == SAVE_EXPR
2112 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2115 /* Next handle constant cases, those for which we can return 1 even
2116 if ONLY_CONST is set. */
2117 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2118 switch (TREE_CODE (arg0))
2121 return (! TREE_CONSTANT_OVERFLOW (arg0)
2122 && ! TREE_CONSTANT_OVERFLOW (arg1)
2123 && TREE_INT_CST_LOW (arg0) == TREE_INT_CST_LOW (arg1)
2124 && TREE_INT_CST_HIGH (arg0) == TREE_INT_CST_HIGH (arg1));
2127 return (! TREE_CONSTANT_OVERFLOW (arg0)
2128 && ! TREE_CONSTANT_OVERFLOW (arg1)
2129 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2130 TREE_REAL_CST (arg1)));
2133 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2135 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2139 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2140 && ! strncmp (TREE_STRING_POINTER (arg0),
2141 TREE_STRING_POINTER (arg1),
2142 TREE_STRING_LENGTH (arg0)));
2145 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2154 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2157 /* Two conversions are equal only if signedness and modes match. */
2158 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2159 && (TREE_UNSIGNED (TREE_TYPE (arg0))
2160 != TREE_UNSIGNED (TREE_TYPE (arg1))))
2163 return operand_equal_p (TREE_OPERAND (arg0, 0),
2164 TREE_OPERAND (arg1, 0), 0);
2168 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
2169 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
2173 /* For commutative ops, allow the other order. */
2174 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
2175 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
2176 || TREE_CODE (arg0) == BIT_IOR_EXPR
2177 || TREE_CODE (arg0) == BIT_XOR_EXPR
2178 || TREE_CODE (arg0) == BIT_AND_EXPR
2179 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
2180 && operand_equal_p (TREE_OPERAND (arg0, 0),
2181 TREE_OPERAND (arg1, 1), 0)
2182 && operand_equal_p (TREE_OPERAND (arg0, 1),
2183 TREE_OPERAND (arg1, 0), 0));
2186 /* If either of the pointer (or reference) expressions we are dereferencing
2187 contain a side effect, these cannot be equal. */
2188 if (TREE_SIDE_EFFECTS (arg0)
2189 || TREE_SIDE_EFFECTS (arg1))
2192 switch (TREE_CODE (arg0))
2195 return operand_equal_p (TREE_OPERAND (arg0, 0),
2196 TREE_OPERAND (arg1, 0), 0);
2200 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2201 TREE_OPERAND (arg1, 0), 0)
2202 && operand_equal_p (TREE_OPERAND (arg0, 1),
2203 TREE_OPERAND (arg1, 1), 0));
2206 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2207 TREE_OPERAND (arg1, 0), 0)
2208 && operand_equal_p (TREE_OPERAND (arg0, 1),
2209 TREE_OPERAND (arg1, 1), 0)
2210 && operand_equal_p (TREE_OPERAND (arg0, 2),
2211 TREE_OPERAND (arg1, 2), 0));
2217 if (TREE_CODE (arg0) == RTL_EXPR)
2218 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2226 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2227 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2229 When in doubt, return 0. */
2232 operand_equal_for_comparison_p (arg0, arg1, other)
2236 int unsignedp1, unsignedpo;
2237 tree primarg0, primarg1, primother;
2238 unsigned correct_width;
2240 if (operand_equal_p (arg0, arg1, 0))
2243 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2244 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2247 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2248 and see if the inner values are the same. This removes any
2249 signedness comparison, which doesn't matter here. */
2250 primarg0 = arg0, primarg1 = arg1;
2251 STRIP_NOPS (primarg0); STRIP_NOPS (primarg1);
2252 if (operand_equal_p (primarg0, primarg1, 0))
2255 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2256 actual comparison operand, ARG0.
2258 First throw away any conversions to wider types
2259 already present in the operands. */
2261 primarg1 = get_narrower (arg1, &unsignedp1);
2262 primother = get_narrower (other, &unsignedpo);
2264 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2265 if (unsignedp1 == unsignedpo
2266 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2267 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2269 tree type = TREE_TYPE (arg0);
2271 /* Make sure shorter operand is extended the right way
2272 to match the longer operand. */
2273 primarg1 = convert (signed_or_unsigned_type (unsignedp1,
2274 TREE_TYPE (primarg1)),
2277 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2284 /* See if ARG is an expression that is either a comparison or is performing
2285 arithmetic on comparisons. The comparisons must only be comparing
2286 two different values, which will be stored in *CVAL1 and *CVAL2; if
2287 they are non-zero it means that some operands have already been found.
2288 No variables may be used anywhere else in the expression except in the
2289 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2290 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2292 If this is true, return 1. Otherwise, return zero. */
2295 twoval_comparison_p (arg, cval1, cval2, save_p)
2297 tree *cval1, *cval2;
2300 enum tree_code code = TREE_CODE (arg);
2301 char class = TREE_CODE_CLASS (code);
2303 /* We can handle some of the 'e' cases here. */
2304 if (class == 'e' && code == TRUTH_NOT_EXPR)
2306 else if (class == 'e'
2307 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2308 || code == COMPOUND_EXPR))
2311 /* ??? Disable this since the SAVE_EXPR might already be in use outside
2312 the expression. There may be no way to make this work, but it needs
2313 to be looked at again for 2.6. */
2315 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0)
2317 /* If we've already found a CVAL1 or CVAL2, this expression is
2318 two complex to handle. */
2319 if (*cval1 || *cval2)
2330 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2333 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2334 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2335 cval1, cval2, save_p));
2341 if (code == COND_EXPR)
2342 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2343 cval1, cval2, save_p)
2344 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2345 cval1, cval2, save_p)
2346 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2347 cval1, cval2, save_p));
2351 /* First see if we can handle the first operand, then the second. For
2352 the second operand, we know *CVAL1 can't be zero. It must be that
2353 one side of the comparison is each of the values; test for the
2354 case where this isn't true by failing if the two operands
2357 if (operand_equal_p (TREE_OPERAND (arg, 0),
2358 TREE_OPERAND (arg, 1), 0))
2362 *cval1 = TREE_OPERAND (arg, 0);
2363 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2365 else if (*cval2 == 0)
2366 *cval2 = TREE_OPERAND (arg, 0);
2367 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2372 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2374 else if (*cval2 == 0)
2375 *cval2 = TREE_OPERAND (arg, 1);
2376 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2388 /* ARG is a tree that is known to contain just arithmetic operations and
2389 comparisons. Evaluate the operations in the tree substituting NEW0 for
2390 any occurrence of OLD0 as an operand of a comparison and likewise for
2394 eval_subst (arg, old0, new0, old1, new1)
2396 tree old0, new0, old1, new1;
2398 tree type = TREE_TYPE (arg);
2399 enum tree_code code = TREE_CODE (arg);
2400 char class = TREE_CODE_CLASS (code);
2402 /* We can handle some of the 'e' cases here. */
2403 if (class == 'e' && code == TRUTH_NOT_EXPR)
2405 else if (class == 'e'
2406 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2412 return fold (build1 (code, type,
2413 eval_subst (TREE_OPERAND (arg, 0),
2414 old0, new0, old1, new1)));
2417 return fold (build (code, type,
2418 eval_subst (TREE_OPERAND (arg, 0),
2419 old0, new0, old1, new1),
2420 eval_subst (TREE_OPERAND (arg, 1),
2421 old0, new0, old1, new1)));
2427 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2430 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2433 return fold (build (code, type,
2434 eval_subst (TREE_OPERAND (arg, 0),
2435 old0, new0, old1, new1),
2436 eval_subst (TREE_OPERAND (arg, 1),
2437 old0, new0, old1, new1),
2438 eval_subst (TREE_OPERAND (arg, 2),
2439 old0, new0, old1, new1)));
2443 /* fall through - ??? */
2447 tree arg0 = TREE_OPERAND (arg, 0);
2448 tree arg1 = TREE_OPERAND (arg, 1);
2450 /* We need to check both for exact equality and tree equality. The
2451 former will be true if the operand has a side-effect. In that
2452 case, we know the operand occurred exactly once. */
2454 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2456 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2459 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2461 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2464 return fold (build (code, type, arg0, arg1));
2472 /* Return a tree for the case when the result of an expression is RESULT
2473 converted to TYPE and OMITTED was previously an operand of the expression
2474 but is now not needed (e.g., we folded OMITTED * 0).
2476 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2477 the conversion of RESULT to TYPE. */
2480 omit_one_operand (type, result, omitted)
2481 tree type, result, omitted;
2483 tree t = convert (type, result);
2485 if (TREE_SIDE_EFFECTS (omitted))
2486 return build (COMPOUND_EXPR, type, omitted, t);
2488 return non_lvalue (t);
2491 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2494 pedantic_omit_one_operand (type, result, omitted)
2495 tree type, result, omitted;
2497 tree t = convert (type, result);
2499 if (TREE_SIDE_EFFECTS (omitted))
2500 return build (COMPOUND_EXPR, type, omitted, t);
2502 return pedantic_non_lvalue (t);
2507 /* Return a simplified tree node for the truth-negation of ARG. This
2508 never alters ARG itself. We assume that ARG is an operation that
2509 returns a truth value (0 or 1). */
2512 invert_truthvalue (arg)
2515 tree type = TREE_TYPE (arg);
2516 enum tree_code code = TREE_CODE (arg);
2518 if (code == ERROR_MARK)
2521 /* If this is a comparison, we can simply invert it, except for
2522 floating-point non-equality comparisons, in which case we just
2523 enclose a TRUTH_NOT_EXPR around what we have. */
2525 if (TREE_CODE_CLASS (code) == '<')
2527 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2528 && !flag_fast_math && code != NE_EXPR && code != EQ_EXPR)
2529 return build1 (TRUTH_NOT_EXPR, type, arg);
2531 return build (invert_tree_comparison (code), type,
2532 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2538 return convert (type, build_int_2 (TREE_INT_CST_LOW (arg) == 0
2539 && TREE_INT_CST_HIGH (arg) == 0, 0));
2541 case TRUTH_AND_EXPR:
2542 return build (TRUTH_OR_EXPR, type,
2543 invert_truthvalue (TREE_OPERAND (arg, 0)),
2544 invert_truthvalue (TREE_OPERAND (arg, 1)));
2547 return build (TRUTH_AND_EXPR, type,
2548 invert_truthvalue (TREE_OPERAND (arg, 0)),
2549 invert_truthvalue (TREE_OPERAND (arg, 1)));
2551 case TRUTH_XOR_EXPR:
2552 /* Here we can invert either operand. We invert the first operand
2553 unless the second operand is a TRUTH_NOT_EXPR in which case our
2554 result is the XOR of the first operand with the inside of the
2555 negation of the second operand. */
2557 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2558 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2559 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2561 return build (TRUTH_XOR_EXPR, type,
2562 invert_truthvalue (TREE_OPERAND (arg, 0)),
2563 TREE_OPERAND (arg, 1));
2565 case TRUTH_ANDIF_EXPR:
2566 return build (TRUTH_ORIF_EXPR, type,
2567 invert_truthvalue (TREE_OPERAND (arg, 0)),
2568 invert_truthvalue (TREE_OPERAND (arg, 1)));
2570 case TRUTH_ORIF_EXPR:
2571 return build (TRUTH_ANDIF_EXPR, type,
2572 invert_truthvalue (TREE_OPERAND (arg, 0)),
2573 invert_truthvalue (TREE_OPERAND (arg, 1)));
2575 case TRUTH_NOT_EXPR:
2576 return TREE_OPERAND (arg, 0);
2579 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2580 invert_truthvalue (TREE_OPERAND (arg, 1)),
2581 invert_truthvalue (TREE_OPERAND (arg, 2)));
2584 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2585 invert_truthvalue (TREE_OPERAND (arg, 1)));
2587 case NON_LVALUE_EXPR:
2588 return invert_truthvalue (TREE_OPERAND (arg, 0));
2593 return build1 (TREE_CODE (arg), type,
2594 invert_truthvalue (TREE_OPERAND (arg, 0)));
2597 if (!integer_onep (TREE_OPERAND (arg, 1)))
2599 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2602 return build1 (TRUTH_NOT_EXPR, type, arg);
2604 case CLEANUP_POINT_EXPR:
2605 return build1 (CLEANUP_POINT_EXPR, type,
2606 invert_truthvalue (TREE_OPERAND (arg, 0)));
2611 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2613 return build1 (TRUTH_NOT_EXPR, type, arg);
2616 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2617 operands are another bit-wise operation with a common input. If so,
2618 distribute the bit operations to save an operation and possibly two if
2619 constants are involved. For example, convert
2620 (A | B) & (A | C) into A | (B & C)
2621 Further simplification will occur if B and C are constants.
2623 If this optimization cannot be done, 0 will be returned. */
2626 distribute_bit_expr (code, type, arg0, arg1)
2627 enum tree_code code;
2634 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2635 || TREE_CODE (arg0) == code
2636 || (TREE_CODE (arg0) != BIT_AND_EXPR
2637 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2640 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2642 common = TREE_OPERAND (arg0, 0);
2643 left = TREE_OPERAND (arg0, 1);
2644 right = TREE_OPERAND (arg1, 1);
2646 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2648 common = TREE_OPERAND (arg0, 0);
2649 left = TREE_OPERAND (arg0, 1);
2650 right = TREE_OPERAND (arg1, 0);
2652 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2654 common = TREE_OPERAND (arg0, 1);
2655 left = TREE_OPERAND (arg0, 0);
2656 right = TREE_OPERAND (arg1, 1);
2658 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2660 common = TREE_OPERAND (arg0, 1);
2661 left = TREE_OPERAND (arg0, 0);
2662 right = TREE_OPERAND (arg1, 0);
2667 return fold (build (TREE_CODE (arg0), type, common,
2668 fold (build (code, type, left, right))));
2671 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2672 starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */
2675 make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp)
2678 int bitsize, bitpos;
2681 tree result = build (BIT_FIELD_REF, type, inner,
2682 size_int (bitsize), bitsize_int (bitpos, 0L));
2684 TREE_UNSIGNED (result) = unsignedp;
2689 /* Optimize a bit-field compare.
2691 There are two cases: First is a compare against a constant and the
2692 second is a comparison of two items where the fields are at the same
2693 bit position relative to the start of a chunk (byte, halfword, word)
2694 large enough to contain it. In these cases we can avoid the shift
2695 implicit in bitfield extractions.
2697 For constants, we emit a compare of the shifted constant with the
2698 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2699 compared. For two fields at the same position, we do the ANDs with the
2700 similar mask and compare the result of the ANDs.
2702 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2703 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2704 are the left and right operands of the comparison, respectively.
2706 If the optimization described above can be done, we return the resulting
2707 tree. Otherwise we return zero. */
2710 optimize_bit_field_compare (code, compare_type, lhs, rhs)
2711 enum tree_code code;
2715 int lbitpos, lbitsize, rbitpos, rbitsize;
2716 int lnbitpos, lnbitsize, rnbitpos = 0, rnbitsize = 0;
2717 tree type = TREE_TYPE (lhs);
2718 tree signed_type, unsigned_type;
2719 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2720 enum machine_mode lmode, rmode, lnmode, rnmode = VOIDmode;
2721 int lunsignedp, runsignedp;
2722 int lvolatilep = 0, rvolatilep = 0;
2724 tree linner, rinner = NULL_TREE;
2728 /* Get all the information about the extractions being done. If the bit size
2729 if the same as the size of the underlying object, we aren't doing an
2730 extraction at all and so can do nothing. */
2731 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2732 &lunsignedp, &lvolatilep, &alignment);
2733 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2739 /* If this is not a constant, we can only do something if bit positions,
2740 sizes, and signedness are the same. */
2741 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2742 &runsignedp, &rvolatilep, &alignment);
2744 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2745 || lunsignedp != runsignedp || offset != 0)
2749 /* See if we can find a mode to refer to this field. We should be able to,
2750 but fail if we can't. */
2751 lnmode = get_best_mode (lbitsize, lbitpos,
2752 TYPE_ALIGN (TREE_TYPE (linner)), word_mode,
2754 if (lnmode == VOIDmode)
2757 /* Set signed and unsigned types of the precision of this mode for the
2759 signed_type = type_for_mode (lnmode, 0);
2760 unsigned_type = type_for_mode (lnmode, 1);
2764 rnmode = get_best_mode (rbitsize, rbitpos,
2765 TYPE_ALIGN (TREE_TYPE (rinner)), word_mode,
2767 if (rnmode == VOIDmode)
2771 /* Compute the bit position and size for the new reference and our offset
2772 within it. If the new reference is the same size as the original, we
2773 won't optimize anything, so return zero. */
2774 lnbitsize = GET_MODE_BITSIZE (lnmode);
2775 lnbitpos = lbitpos & ~ (lnbitsize - 1);
2776 lbitpos -= lnbitpos;
2777 if (lnbitsize == lbitsize)
2782 rnbitsize = GET_MODE_BITSIZE (rnmode);
2783 rnbitpos = rbitpos & ~ (rnbitsize - 1);
2784 rbitpos -= rnbitpos;
2785 if (rnbitsize == rbitsize)
2789 if (BYTES_BIG_ENDIAN)
2790 lbitpos = lnbitsize - lbitsize - lbitpos;
2792 /* Make the mask to be used against the extracted field. */
2793 mask = build_int_2 (~0, ~0);
2794 TREE_TYPE (mask) = unsigned_type;
2795 force_fit_type (mask, 0);
2796 mask = convert (unsigned_type, mask);
2797 mask = const_binop (LSHIFT_EXPR, mask, size_int (lnbitsize - lbitsize), 0);
2798 mask = const_binop (RSHIFT_EXPR, mask,
2799 size_int (lnbitsize - lbitsize - lbitpos), 0);
2802 /* If not comparing with constant, just rework the comparison
2804 return build (code, compare_type,
2805 build (BIT_AND_EXPR, unsigned_type,
2806 make_bit_field_ref (linner, unsigned_type,
2807 lnbitsize, lnbitpos, 1),
2809 build (BIT_AND_EXPR, unsigned_type,
2810 make_bit_field_ref (rinner, unsigned_type,
2811 rnbitsize, rnbitpos, 1),
2814 /* Otherwise, we are handling the constant case. See if the constant is too
2815 big for the field. Warn and return a tree of for 0 (false) if so. We do
2816 this not only for its own sake, but to avoid having to test for this
2817 error case below. If we didn't, we might generate wrong code.
2819 For unsigned fields, the constant shifted right by the field length should
2820 be all zero. For signed fields, the high-order bits should agree with
2825 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2826 convert (unsigned_type, rhs),
2827 size_int (lbitsize), 0)))
2829 warning ("comparison is always %d due to width of bitfield",
2831 return convert (compare_type,
2833 ? integer_one_node : integer_zero_node));
2838 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
2839 size_int (lbitsize - 1), 0);
2840 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2842 warning ("comparison is always %d due to width of bitfield",
2844 return convert (compare_type,
2846 ? integer_one_node : integer_zero_node));
2850 /* Single-bit compares should always be against zero. */
2851 if (lbitsize == 1 && ! integer_zerop (rhs))
2853 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2854 rhs = convert (type, integer_zero_node);
2857 /* Make a new bitfield reference, shift the constant over the
2858 appropriate number of bits and mask it with the computed mask
2859 (in case this was a signed field). If we changed it, make a new one. */
2860 lhs = make_bit_field_ref (linner, unsigned_type, lnbitsize, lnbitpos, 1);
2863 TREE_SIDE_EFFECTS (lhs) = 1;
2864 TREE_THIS_VOLATILE (lhs) = 1;
2867 rhs = fold (const_binop (BIT_AND_EXPR,
2868 const_binop (LSHIFT_EXPR,
2869 convert (unsigned_type, rhs),
2870 size_int (lbitpos), 0),
2873 return build (code, compare_type,
2874 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2878 /* Subroutine for fold_truthop: decode a field reference.
2880 If EXP is a comparison reference, we return the innermost reference.
2882 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2883 set to the starting bit number.
2885 If the innermost field can be completely contained in a mode-sized
2886 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2888 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2889 otherwise it is not changed.
2891 *PUNSIGNEDP is set to the signedness of the field.
2893 *PMASK is set to the mask used. This is either contained in a
2894 BIT_AND_EXPR or derived from the width of the field.
2896 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2898 Return 0 if this is not a component reference or is one that we can't
2899 do anything with. */
2902 decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp,
2903 pvolatilep, pmask, pand_mask)
2905 int *pbitsize, *pbitpos;
2906 enum machine_mode *pmode;
2907 int *punsignedp, *pvolatilep;
2912 tree mask, inner, offset;
2917 /* All the optimizations using this function assume integer fields.
2918 There are problems with FP fields since the type_for_size call
2919 below can fail for, e.g., XFmode. */
2920 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
2925 if (TREE_CODE (exp) == BIT_AND_EXPR)
2927 and_mask = TREE_OPERAND (exp, 1);
2928 exp = TREE_OPERAND (exp, 0);
2929 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
2930 if (TREE_CODE (and_mask) != INTEGER_CST)
2935 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
2936 punsignedp, pvolatilep, &alignment);
2937 if ((inner == exp && and_mask == 0)
2938 || *pbitsize < 0 || offset != 0)
2941 /* Compute the mask to access the bitfield. */
2942 unsigned_type = type_for_size (*pbitsize, 1);
2943 precision = TYPE_PRECISION (unsigned_type);
2945 mask = build_int_2 (~0, ~0);
2946 TREE_TYPE (mask) = unsigned_type;
2947 force_fit_type (mask, 0);
2948 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2949 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2951 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
2953 mask = fold (build (BIT_AND_EXPR, unsigned_type,
2954 convert (unsigned_type, and_mask), mask));
2957 *pand_mask = and_mask;
2961 /* Return non-zero if MASK represents a mask of SIZE ones in the low-order
2965 all_ones_mask_p (mask, size)
2969 tree type = TREE_TYPE (mask);
2970 int precision = TYPE_PRECISION (type);
2973 tmask = build_int_2 (~0, ~0);
2974 TREE_TYPE (tmask) = signed_type (type);
2975 force_fit_type (tmask, 0);
2977 tree_int_cst_equal (mask,
2978 const_binop (RSHIFT_EXPR,
2979 const_binop (LSHIFT_EXPR, tmask,
2980 size_int (precision - size),
2982 size_int (precision - size), 0));
2985 /* Subroutine for fold_truthop: determine if an operand is simple enough
2986 to be evaluated unconditionally. */
2989 simple_operand_p (exp)
2992 /* Strip any conversions that don't change the machine mode. */
2993 while ((TREE_CODE (exp) == NOP_EXPR
2994 || TREE_CODE (exp) == CONVERT_EXPR)
2995 && (TYPE_MODE (TREE_TYPE (exp))
2996 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
2997 exp = TREE_OPERAND (exp, 0);
2999 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
3000 || (TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
3001 && ! TREE_ADDRESSABLE (exp)
3002 && ! TREE_THIS_VOLATILE (exp)
3003 && ! DECL_NONLOCAL (exp)
3004 /* Don't regard global variables as simple. They may be
3005 allocated in ways unknown to the compiler (shared memory,
3006 #pragma weak, etc). */
3007 && ! TREE_PUBLIC (exp)
3008 && ! DECL_EXTERNAL (exp)
3009 /* Loading a static variable is unduly expensive, but global
3010 registers aren't expensive. */
3011 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3014 /* The following functions are subroutines to fold_range_test and allow it to
3015 try to change a logical combination of comparisons into a range test.
3018 X == 2 && X == 3 && X == 4 && X == 5
3022 (unsigned) (X - 2) <= 3
3024 We describe each set of comparisons as being either inside or outside
3025 a range, using a variable named like IN_P, and then describe the
3026 range with a lower and upper bound. If one of the bounds is omitted,
3027 it represents either the highest or lowest value of the type.
3029 In the comments below, we represent a range by two numbers in brackets
3030 preceded by a "+" to designate being inside that range, or a "-" to
3031 designate being outside that range, so the condition can be inverted by
3032 flipping the prefix. An omitted bound is represented by a "-". For
3033 example, "- [-, 10]" means being outside the range starting at the lowest
3034 possible value and ending at 10, in other words, being greater than 10.
3035 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3038 We set up things so that the missing bounds are handled in a consistent
3039 manner so neither a missing bound nor "true" and "false" need to be
3040 handled using a special case. */
3042 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3043 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3044 and UPPER1_P are nonzero if the respective argument is an upper bound
3045 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3046 must be specified for a comparison. ARG1 will be converted to ARG0's
3047 type if both are specified. */
3050 range_binop (code, type, arg0, upper0_p, arg1, upper1_p)
3051 enum tree_code code;
3054 int upper0_p, upper1_p;
3060 /* If neither arg represents infinity, do the normal operation.
3061 Else, if not a comparison, return infinity. Else handle the special
3062 comparison rules. Note that most of the cases below won't occur, but
3063 are handled for consistency. */
3065 if (arg0 != 0 && arg1 != 0)
3067 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
3068 arg0, convert (TREE_TYPE (arg0), arg1)));
3070 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3073 if (TREE_CODE_CLASS (code) != '<')
3076 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3077 for neither. In real maths, we cannot assume open ended ranges are
3078 the same. But, this is computer arithmetic, where numbers are finite.
3079 We can therefore make the transformation of any unbounded range with
3080 the value Z, Z being greater than any representable number. This permits
3081 us to treat unbounded ranges as equal. */
3082 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3083 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3087 result = sgn0 == sgn1;
3090 result = sgn0 != sgn1;
3093 result = sgn0 < sgn1;
3096 result = sgn0 <= sgn1;
3099 result = sgn0 > sgn1;
3102 result = sgn0 >= sgn1;
3108 return convert (type, result ? integer_one_node : integer_zero_node);
3111 /* Given EXP, a logical expression, set the range it is testing into
3112 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3113 actually being tested. *PLOW and *PHIGH will have be made the same type
3114 as the returned expression. If EXP is not a comparison, we will most
3115 likely not be returning a useful value and range. */
3118 make_range (exp, pin_p, plow, phigh)
3123 enum tree_code code;
3124 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
3125 tree orig_type = NULL_TREE;
3127 tree low, high, n_low, n_high;
3129 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3130 and see if we can refine the range. Some of the cases below may not
3131 happen, but it doesn't seem worth worrying about this. We "continue"
3132 the outer loop when we've changed something; otherwise we "break"
3133 the switch, which will "break" the while. */
3135 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
3139 code = TREE_CODE (exp);
3141 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3143 arg0 = TREE_OPERAND (exp, 0);
3144 if (TREE_CODE_CLASS (code) == '<'
3145 || TREE_CODE_CLASS (code) == '1'
3146 || TREE_CODE_CLASS (code) == '2')
3147 type = TREE_TYPE (arg0);
3148 if (TREE_CODE_CLASS (code) == '2'
3149 || TREE_CODE_CLASS (code) == '<'
3150 || (TREE_CODE_CLASS (code) == 'e'
3151 && tree_code_length[(int) code] > 1))
3152 arg1 = TREE_OPERAND (exp, 1);
3155 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3156 lose a cast by accident. */
3157 if (type != NULL_TREE && orig_type == NULL_TREE)
3162 case TRUTH_NOT_EXPR:
3163 in_p = ! in_p, exp = arg0;
3166 case EQ_EXPR: case NE_EXPR:
3167 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3168 /* We can only do something if the range is testing for zero
3169 and if the second operand is an integer constant. Note that
3170 saying something is "in" the range we make is done by
3171 complementing IN_P since it will set in the initial case of
3172 being not equal to zero; "out" is leaving it alone. */
3173 if (low == 0 || high == 0
3174 || ! integer_zerop (low) || ! integer_zerop (high)
3175 || TREE_CODE (arg1) != INTEGER_CST)
3180 case NE_EXPR: /* - [c, c] */
3183 case EQ_EXPR: /* + [c, c] */
3184 in_p = ! in_p, low = high = arg1;
3186 case GT_EXPR: /* - [-, c] */
3187 low = 0, high = arg1;
3189 case GE_EXPR: /* + [c, -] */
3190 in_p = ! in_p, low = arg1, high = 0;
3192 case LT_EXPR: /* - [c, -] */
3193 low = arg1, high = 0;
3195 case LE_EXPR: /* + [-, c] */
3196 in_p = ! in_p, low = 0, high = arg1;
3204 /* If this is an unsigned comparison, we also know that EXP is
3205 greater than or equal to zero. We base the range tests we make
3206 on that fact, so we record it here so we can parse existing
3208 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3210 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3211 1, convert (type, integer_zero_node),
3215 in_p = n_in_p, low = n_low, high = n_high;
3217 /* If the high bound is missing, reverse the range so it
3218 goes from zero to the low bound minus 1. */
3222 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3223 integer_one_node, 0);
3224 low = convert (type, integer_zero_node);
3230 /* (-x) IN [a,b] -> x in [-b, -a] */
3231 n_low = range_binop (MINUS_EXPR, type,
3232 convert (type, integer_zero_node), 0, high, 1);
3233 n_high = range_binop (MINUS_EXPR, type,
3234 convert (type, integer_zero_node), 0, low, 0);
3235 low = n_low, high = n_high;
3241 exp = build (MINUS_EXPR, type, build1 (NEGATE_EXPR, type, arg0),
3242 convert (type, integer_one_node));
3245 case PLUS_EXPR: case MINUS_EXPR:
3246 if (TREE_CODE (arg1) != INTEGER_CST)
3249 /* If EXP is signed, any overflow in the computation is undefined,
3250 so we don't worry about it so long as our computations on
3251 the bounds don't overflow. For unsigned, overflow is defined
3252 and this is exactly the right thing. */
3253 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3254 type, low, 0, arg1, 0);
3255 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3256 type, high, 1, arg1, 0);
3257 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3258 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3261 /* Check for an unsigned range which has wrapped around the maximum
3262 value thus making n_high < n_low, and normalize it. */
3263 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3265 low = range_binop (PLUS_EXPR, type, n_high, 0,
3266 integer_one_node, 0);
3267 high = range_binop (MINUS_EXPR, type, n_low, 0,
3268 integer_one_node, 0);
3272 low = n_low, high = n_high;
3277 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3278 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3281 if (! INTEGRAL_TYPE_P (type)
3282 || (low != 0 && ! int_fits_type_p (low, type))
3283 || (high != 0 && ! int_fits_type_p (high, type)))
3286 n_low = low, n_high = high;
3289 n_low = convert (type, n_low);
3292 n_high = convert (type, n_high);
3294 /* If we're converting from an unsigned to a signed type,
3295 we will be doing the comparison as unsigned. The tests above
3296 have already verified that LOW and HIGH are both positive.
3298 So we have to make sure that the original unsigned value will
3299 be interpreted as positive. */
3300 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3302 tree equiv_type = type_for_mode (TYPE_MODE (type), 1);
3305 /* A range without an upper bound is, naturally, unbounded.
3306 Since convert would have cropped a very large value, use
3307 the max value for the destination type. */
3309 high_positive = TYPE_MAX_VALUE (equiv_type);
3312 high_positive = TYPE_MAX_VALUE (type);
3316 high_positive = fold (build (RSHIFT_EXPR, type,
3317 convert (type, high_positive),
3318 convert (type, integer_one_node)));
3320 /* If the low bound is specified, "and" the range with the
3321 range for which the original unsigned value will be
3325 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3327 1, convert (type, integer_zero_node),
3331 in_p = (n_in_p == in_p);
3335 /* Otherwise, "or" the range with the range of the input
3336 that will be interpreted as negative. */
3337 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3339 1, convert (type, integer_zero_node),
3343 in_p = (in_p != n_in_p);
3348 low = n_low, high = n_high;
3358 /* If EXP is a constant, we can evaluate whether this is true or false. */
3359 if (TREE_CODE (exp) == INTEGER_CST)
3361 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3363 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3369 *pin_p = in_p, *plow = low, *phigh = high;
3373 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3374 type, TYPE, return an expression to test if EXP is in (or out of, depending
3375 on IN_P) the range. */
3378 build_range_check (type, exp, in_p, low, high)
3384 tree etype = TREE_TYPE (exp);
3388 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3389 return invert_truthvalue (value);
3391 else if (low == 0 && high == 0)
3392 return convert (type, integer_one_node);
3395 return fold (build (LE_EXPR, type, exp, high));
3398 return fold (build (GE_EXPR, type, exp, low));
3400 else if (operand_equal_p (low, high, 0))
3401 return fold (build (EQ_EXPR, type, exp, low));
3403 else if (TREE_UNSIGNED (etype) && integer_zerop (low))
3404 return build_range_check (type, exp, 1, 0, high);
3406 else if (integer_zerop (low))
3408 utype = unsigned_type (etype);
3409 return build_range_check (type, convert (utype, exp), 1, 0,
3410 convert (utype, high));
3413 else if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3414 && ! TREE_OVERFLOW (value))
3415 return build_range_check (type,
3416 fold (build (MINUS_EXPR, etype, exp, low)),
3417 1, convert (etype, integer_zero_node), value);
3422 /* Given two ranges, see if we can merge them into one. Return 1 if we
3423 can, 0 if we can't. Set the output range into the specified parameters. */
3426 merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
3430 tree low0, high0, low1, high1;
3438 int lowequal = ((low0 == 0 && low1 == 0)
3439 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3440 low0, 0, low1, 0)));
3441 int highequal = ((high0 == 0 && high1 == 0)
3442 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3443 high0, 1, high1, 1)));
3445 /* Make range 0 be the range that starts first, or ends last if they
3446 start at the same value. Swap them if it isn't. */
3447 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3450 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3451 high1, 1, high0, 1))))
3453 temp = in0_p, in0_p = in1_p, in1_p = temp;
3454 tem = low0, low0 = low1, low1 = tem;
3455 tem = high0, high0 = high1, high1 = tem;
3458 /* Now flag two cases, whether the ranges are disjoint or whether the
3459 second range is totally subsumed in the first. Note that the tests
3460 below are simplified by the ones above. */
3461 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3462 high0, 1, low1, 0));
3463 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3464 high1, 1, high0, 1));
3466 /* We now have four cases, depending on whether we are including or
3467 excluding the two ranges. */
3470 /* If they don't overlap, the result is false. If the second range
3471 is a subset it is the result. Otherwise, the range is from the start
3472 of the second to the end of the first. */
3474 in_p = 0, low = high = 0;
3476 in_p = 1, low = low1, high = high1;
3478 in_p = 1, low = low1, high = high0;
3481 else if (in0_p && ! in1_p)
3483 /* If they don't overlap, the result is the first range. If they are
3484 equal, the result is false. If the second range is a subset of the
3485 first, and the ranges begin at the same place, we go from just after
3486 the end of the first range to the end of the second. If the second
3487 range is not a subset of the first, or if it is a subset and both
3488 ranges end at the same place, the range starts at the start of the
3489 first range and ends just before the second range.
3490 Otherwise, we can't describe this as a single range. */
3492 in_p = 1, low = low0, high = high0;
3493 else if (lowequal && highequal)
3494 in_p = 0, low = high = 0;
3495 else if (subset && lowequal)
3497 in_p = 1, high = high0;
3498 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3499 integer_one_node, 0);
3501 else if (! subset || highequal)
3503 in_p = 1, low = low0;
3504 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3505 integer_one_node, 0);
3511 else if (! in0_p && in1_p)
3513 /* If they don't overlap, the result is the second range. If the second
3514 is a subset of the first, the result is false. Otherwise,
3515 the range starts just after the first range and ends at the
3516 end of the second. */
3518 in_p = 1, low = low1, high = high1;
3520 in_p = 0, low = high = 0;
3523 in_p = 1, high = high1;
3524 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3525 integer_one_node, 0);
3531 /* The case where we are excluding both ranges. Here the complex case
3532 is if they don't overlap. In that case, the only time we have a
3533 range is if they are adjacent. If the second is a subset of the
3534 first, the result is the first. Otherwise, the range to exclude
3535 starts at the beginning of the first range and ends at the end of the
3539 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3540 range_binop (PLUS_EXPR, NULL_TREE,
3542 integer_one_node, 1),
3544 in_p = 0, low = low0, high = high1;
3549 in_p = 0, low = low0, high = high0;
3551 in_p = 0, low = low0, high = high1;
3554 *pin_p = in_p, *plow = low, *phigh = high;
3558 /* EXP is some logical combination of boolean tests. See if we can
3559 merge it into some range test. Return the new tree if so. */
3562 fold_range_test (exp)
3565 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3566 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3567 int in0_p, in1_p, in_p;
3568 tree low0, low1, low, high0, high1, high;
3569 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3570 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3573 /* Fail if anything is volatile. */
3574 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3577 /* If this is an OR operation, invert both sides; we will invert
3578 again at the end. */
3580 in0_p = ! in0_p, in1_p = ! in1_p;
3582 /* If both expressions are the same, if we can merge the ranges, and we
3583 can build the range test, return it or it inverted. If one of the
3584 ranges is always true or always false, consider it to be the same
3585 expression as the other. */
3586 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3587 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3589 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3591 : rhs != 0 ? rhs : integer_zero_node,
3593 return or_op ? invert_truthvalue (tem) : tem;
3595 /* On machines where the branch cost is expensive, if this is a
3596 short-circuited branch and the underlying object on both sides
3597 is the same, make a non-short-circuit operation. */
3598 else if (BRANCH_COST >= 2
3599 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3600 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3601 && operand_equal_p (lhs, rhs, 0))
3603 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3604 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3605 which cases we can't do this. */
3606 if (simple_operand_p (lhs))
3607 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3608 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3609 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3610 TREE_OPERAND (exp, 1));
3612 else if (global_bindings_p () == 0
3613 && ! contains_placeholder_p (lhs))
3615 tree common = save_expr (lhs);
3617 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3618 or_op ? ! in0_p : in0_p,
3620 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3621 or_op ? ! in1_p : in1_p,
3623 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3624 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3625 TREE_TYPE (exp), lhs, rhs);
3632 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3633 bit value. Arrange things so the extra bits will be set to zero if and
3634 only if C is signed-extended to its full width. If MASK is nonzero,
3635 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3638 unextend (c, p, unsignedp, mask)
3644 tree type = TREE_TYPE (c);
3645 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3648 if (p == modesize || unsignedp)
3651 /* We work by getting just the sign bit into the low-order bit, then
3652 into the high-order bit, then sign-extend. We then XOR that value
3654 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3655 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3657 /* We must use a signed type in order to get an arithmetic right shift.
3658 However, we must also avoid introducing accidental overflows, so that
3659 a subsequent call to integer_zerop will work. Hence we must
3660 do the type conversion here. At this point, the constant is either
3661 zero or one, and the conversion to a signed type can never overflow.
3662 We could get an overflow if this conversion is done anywhere else. */
3663 if (TREE_UNSIGNED (type))
3664 temp = convert (signed_type (type), temp);
3666 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3667 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3669 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3670 /* If necessary, convert the type back to match the type of C. */
3671 if (TREE_UNSIGNED (type))
3672 temp = convert (type, temp);
3674 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3677 /* Find ways of folding logical expressions of LHS and RHS:
3678 Try to merge two comparisons to the same innermost item.
3679 Look for range tests like "ch >= '0' && ch <= '9'".
3680 Look for combinations of simple terms on machines with expensive branches
3681 and evaluate the RHS unconditionally.
3683 For example, if we have p->a == 2 && p->b == 4 and we can make an
3684 object large enough to span both A and B, we can do this with a comparison
3685 against the object ANDed with the a mask.
3687 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3688 operations to do this with one comparison.
3690 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3691 function and the one above.
3693 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3694 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3696 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3699 We return the simplified tree or 0 if no optimization is possible. */
3702 fold_truthop (code, truth_type, lhs, rhs)
3703 enum tree_code code;
3704 tree truth_type, lhs, rhs;
3706 /* If this is the "or" of two comparisons, we can do something if we
3707 the comparisons are NE_EXPR. If this is the "and", we can do something
3708 if the comparisons are EQ_EXPR. I.e.,
3709 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3711 WANTED_CODE is this operation code. For single bit fields, we can
3712 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3713 comparison for one-bit fields. */
3715 enum tree_code wanted_code;
3716 enum tree_code lcode, rcode;
3717 tree ll_arg, lr_arg, rl_arg, rr_arg;
3718 tree ll_inner, lr_inner, rl_inner, rr_inner;
3719 int ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3720 int rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3721 int xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3722 int lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3723 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3724 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3725 enum machine_mode lnmode, rnmode;
3726 tree ll_mask, lr_mask, rl_mask, rr_mask;
3727 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3728 tree l_const, r_const;
3729 tree lntype, rntype, result;
3730 int first_bit, end_bit;
3733 /* Start by getting the comparison codes. Fail if anything is volatile.
3734 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3735 it were surrounded with a NE_EXPR. */
3737 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3740 lcode = TREE_CODE (lhs);
3741 rcode = TREE_CODE (rhs);
3743 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3744 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3746 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3747 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3749 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3752 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3753 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3755 ll_arg = TREE_OPERAND (lhs, 0);
3756 lr_arg = TREE_OPERAND (lhs, 1);
3757 rl_arg = TREE_OPERAND (rhs, 0);
3758 rr_arg = TREE_OPERAND (rhs, 1);
3760 /* If the RHS can be evaluated unconditionally and its operands are
3761 simple, it wins to evaluate the RHS unconditionally on machines
3762 with expensive branches. In this case, this isn't a comparison
3763 that can be merged. */
3765 /* @@ I'm not sure it wins on the m88110 to do this if the comparisons
3766 are with zero (tmw). */
3768 if (BRANCH_COST >= 2
3769 && INTEGRAL_TYPE_P (TREE_TYPE (rhs))
3770 && simple_operand_p (rl_arg)
3771 && simple_operand_p (rr_arg))
3772 return build (code, truth_type, lhs, rhs);
3774 /* See if the comparisons can be merged. Then get all the parameters for
3777 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3778 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3782 ll_inner = decode_field_reference (ll_arg,
3783 &ll_bitsize, &ll_bitpos, &ll_mode,
3784 &ll_unsignedp, &volatilep, &ll_mask,
3786 lr_inner = decode_field_reference (lr_arg,
3787 &lr_bitsize, &lr_bitpos, &lr_mode,
3788 &lr_unsignedp, &volatilep, &lr_mask,
3790 rl_inner = decode_field_reference (rl_arg,
3791 &rl_bitsize, &rl_bitpos, &rl_mode,
3792 &rl_unsignedp, &volatilep, &rl_mask,
3794 rr_inner = decode_field_reference (rr_arg,
3795 &rr_bitsize, &rr_bitpos, &rr_mode,
3796 &rr_unsignedp, &volatilep, &rr_mask,
3799 /* It must be true that the inner operation on the lhs of each
3800 comparison must be the same if we are to be able to do anything.
3801 Then see if we have constants. If not, the same must be true for
3803 if (volatilep || ll_inner == 0 || rl_inner == 0
3804 || ! operand_equal_p (ll_inner, rl_inner, 0))
3807 if (TREE_CODE (lr_arg) == INTEGER_CST
3808 && TREE_CODE (rr_arg) == INTEGER_CST)
3809 l_const = lr_arg, r_const = rr_arg;
3810 else if (lr_inner == 0 || rr_inner == 0
3811 || ! operand_equal_p (lr_inner, rr_inner, 0))
3814 l_const = r_const = 0;
3816 /* If either comparison code is not correct for our logical operation,
3817 fail. However, we can convert a one-bit comparison against zero into
3818 the opposite comparison against that bit being set in the field. */
3820 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
3821 if (lcode != wanted_code)
3823 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
3825 /* Make the left operand unsigned, since we are only interested
3826 in the value of one bit. Otherwise we are doing the wrong
3835 /* This is analogous to the code for l_const above. */
3836 if (rcode != wanted_code)
3838 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
3847 /* See if we can find a mode that contains both fields being compared on
3848 the left. If we can't, fail. Otherwise, update all constants and masks
3849 to be relative to a field of that size. */
3850 first_bit = MIN (ll_bitpos, rl_bitpos);
3851 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
3852 lnmode = get_best_mode (end_bit - first_bit, first_bit,
3853 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
3855 if (lnmode == VOIDmode)
3858 lnbitsize = GET_MODE_BITSIZE (lnmode);
3859 lnbitpos = first_bit & ~ (lnbitsize - 1);
3860 lntype = type_for_size (lnbitsize, 1);
3861 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
3863 if (BYTES_BIG_ENDIAN)
3865 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
3866 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
3869 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
3870 size_int (xll_bitpos), 0);
3871 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
3872 size_int (xrl_bitpos), 0);
3876 l_const = convert (lntype, l_const);
3877 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
3878 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
3879 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
3880 fold (build1 (BIT_NOT_EXPR,
3884 warning ("comparison is always %d", wanted_code == NE_EXPR);
3886 return convert (truth_type,
3887 wanted_code == NE_EXPR
3888 ? integer_one_node : integer_zero_node);
3893 r_const = convert (lntype, r_const);
3894 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
3895 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
3896 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
3897 fold (build1 (BIT_NOT_EXPR,
3901 warning ("comparison is always %d", wanted_code == NE_EXPR);
3903 return convert (truth_type,
3904 wanted_code == NE_EXPR
3905 ? integer_one_node : integer_zero_node);
3909 /* If the right sides are not constant, do the same for it. Also,
3910 disallow this optimization if a size or signedness mismatch occurs
3911 between the left and right sides. */
3914 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
3915 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
3916 /* Make sure the two fields on the right
3917 correspond to the left without being swapped. */
3918 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
3921 first_bit = MIN (lr_bitpos, rr_bitpos);
3922 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
3923 rnmode = get_best_mode (end_bit - first_bit, first_bit,
3924 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
3926 if (rnmode == VOIDmode)
3929 rnbitsize = GET_MODE_BITSIZE (rnmode);
3930 rnbitpos = first_bit & ~ (rnbitsize - 1);
3931 rntype = type_for_size (rnbitsize, 1);
3932 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
3934 if (BYTES_BIG_ENDIAN)
3936 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
3937 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
3940 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
3941 size_int (xlr_bitpos), 0);
3942 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
3943 size_int (xrr_bitpos), 0);
3945 /* Make a mask that corresponds to both fields being compared.
3946 Do this for both items being compared. If the operands are the
3947 same size and the bits being compared are in the same position
3948 then we can do this by masking both and comparing the masked
3950 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3951 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
3952 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
3954 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
3955 ll_unsignedp || rl_unsignedp);
3956 if (! all_ones_mask_p (ll_mask, lnbitsize))
3957 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
3959 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
3960 lr_unsignedp || rr_unsignedp);
3961 if (! all_ones_mask_p (lr_mask, rnbitsize))
3962 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
3964 return build (wanted_code, truth_type, lhs, rhs);
3967 /* There is still another way we can do something: If both pairs of
3968 fields being compared are adjacent, we may be able to make a wider
3969 field containing them both.
3971 Note that we still must mask the lhs/rhs expressions. Furthermore,
3972 the mask must be shifted to account for the shift done by
3973 make_bit_field_ref. */
3974 if ((ll_bitsize + ll_bitpos == rl_bitpos
3975 && lr_bitsize + lr_bitpos == rr_bitpos)
3976 || (ll_bitpos == rl_bitpos + rl_bitsize
3977 && lr_bitpos == rr_bitpos + rr_bitsize))
3981 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
3982 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
3983 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
3984 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
3986 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
3987 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
3988 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
3989 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
3991 /* Convert to the smaller type before masking out unwanted bits. */
3993 if (lntype != rntype)
3995 if (lnbitsize > rnbitsize)
3997 lhs = convert (rntype, lhs);
3998 ll_mask = convert (rntype, ll_mask);
4001 else if (lnbitsize < rnbitsize)
4003 rhs = convert (lntype, rhs);
4004 lr_mask = convert (lntype, lr_mask);
4009 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4010 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
4012 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4013 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
4015 return build (wanted_code, truth_type, lhs, rhs);
4021 /* Handle the case of comparisons with constants. If there is something in
4022 common between the masks, those bits of the constants must be the same.
4023 If not, the condition is always false. Test for this to avoid generating
4024 incorrect code below. */
4025 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4026 if (! integer_zerop (result)
4027 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4028 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4030 if (wanted_code == NE_EXPR)
4032 warning ("`or' of unmatched not-equal tests is always 1");
4033 return convert (truth_type, integer_one_node);
4037 warning ("`and' of mutually exclusive equal-tests is always 0");
4038 return convert (truth_type, integer_zero_node);
4042 /* Construct the expression we will return. First get the component
4043 reference we will make. Unless the mask is all ones the width of
4044 that field, perform the mask operation. Then compare with the
4046 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4047 ll_unsignedp || rl_unsignedp);
4049 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4050 if (! all_ones_mask_p (ll_mask, lnbitsize))
4051 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
4053 return build (wanted_code, truth_type, result,
4054 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4057 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4058 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4059 that we may sometimes modify the tree. */
4062 strip_compound_expr (t, s)
4066 enum tree_code code = TREE_CODE (t);
4068 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4069 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4070 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4071 return TREE_OPERAND (t, 1);
4073 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4074 don't bother handling any other types. */
4075 else if (code == COND_EXPR)
4077 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4078 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4079 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4081 else if (TREE_CODE_CLASS (code) == '1')
4082 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4083 else if (TREE_CODE_CLASS (code) == '<'
4084 || TREE_CODE_CLASS (code) == '2')
4086 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4087 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4093 /* Return a node which has the indicated constant VALUE (either 0 or
4094 1), and is of the indicated TYPE. */
4097 constant_boolean_node (value, type)
4101 if (type == integer_type_node)
4102 return value ? integer_one_node : integer_zero_node;
4103 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4104 return truthvalue_conversion (value ? integer_one_node :
4108 tree t = build_int_2 (value, 0);
4109 TREE_TYPE (t) = type;
4114 /* Utility function for the following routine, to see how complex a nesting of
4115 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4116 we don't care (to avoid spending too much time on complex expressions.). */
4119 count_cond (expr, lim)
4125 if (TREE_CODE (expr) != COND_EXPR)
4130 true = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4131 false = count_cond (TREE_OPERAND (expr, 2), lim - 1 - true);
4132 return MIN (lim, 1 + true + false);
4135 /* Perform constant folding and related simplification of EXPR.
4136 The related simplifications include x*1 => x, x*0 => 0, etc.,
4137 and application of the associative law.
4138 NOP_EXPR conversions may be removed freely (as long as we
4139 are careful not to change the C type of the overall expression)
4140 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4141 but we can constant-fold them if they have constant operands. */
4147 register tree t = expr;
4148 tree t1 = NULL_TREE;
4150 tree type = TREE_TYPE (expr);
4151 register tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4152 register enum tree_code code = TREE_CODE (t);
4156 /* WINS will be nonzero when the switch is done
4157 if all operands are constant. */
4161 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4162 Likewise for a SAVE_EXPR that's already been evaluated. */
4163 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t)) != 0)
4166 /* Return right away if already constant. */
4167 if (TREE_CONSTANT (t))
4169 if (code == CONST_DECL)
4170 return DECL_INITIAL (t);
4174 #ifdef MAX_INTEGER_COMPUTATION_MODE
4175 check_max_integer_computation_mode (expr);
4178 kind = TREE_CODE_CLASS (code);
4179 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4183 /* Special case for conversion ops that can have fixed point args. */
4184 arg0 = TREE_OPERAND (t, 0);
4186 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4188 STRIP_TYPE_NOPS (arg0);
4190 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4191 subop = TREE_REALPART (arg0);
4195 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4196 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4197 && TREE_CODE (subop) != REAL_CST
4198 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4200 /* Note that TREE_CONSTANT isn't enough:
4201 static var addresses are constant but we can't
4202 do arithmetic on them. */
4205 else if (kind == 'e' || kind == '<'
4206 || kind == '1' || kind == '2' || kind == 'r')
4208 register int len = tree_code_length[(int) code];
4210 for (i = 0; i < len; i++)
4212 tree op = TREE_OPERAND (t, i);
4216 continue; /* Valid for CALL_EXPR, at least. */
4218 if (kind == '<' || code == RSHIFT_EXPR)
4220 /* Signedness matters here. Perhaps we can refine this
4222 STRIP_TYPE_NOPS (op);
4226 /* Strip any conversions that don't change the mode. */
4230 if (TREE_CODE (op) == COMPLEX_CST)
4231 subop = TREE_REALPART (op);
4235 if (TREE_CODE (subop) != INTEGER_CST
4236 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4237 && TREE_CODE (subop) != REAL_CST
4238 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4240 /* Note that TREE_CONSTANT isn't enough:
4241 static var addresses are constant but we can't
4242 do arithmetic on them. */
4252 /* If this is a commutative operation, and ARG0 is a constant, move it
4253 to ARG1 to reduce the number of tests below. */
4254 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
4255 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
4256 || code == BIT_AND_EXPR)
4257 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
4259 tem = arg0; arg0 = arg1; arg1 = tem;
4261 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
4262 TREE_OPERAND (t, 1) = tem;
4265 /* Now WINS is set as described above,
4266 ARG0 is the first operand of EXPR,
4267 and ARG1 is the second operand (if it has more than one operand).
4269 First check for cases where an arithmetic operation is applied to a
4270 compound, conditional, or comparison operation. Push the arithmetic
4271 operation inside the compound or conditional to see if any folding
4272 can then be done. Convert comparison to conditional for this purpose.
4273 The also optimizes non-constant cases that used to be done in
4276 Before we do that, see if this is a BIT_AND_EXPR or a BIT_OR_EXPR,
4277 one of the operands is a comparison and the other is a comparison, a
4278 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
4279 code below would make the expression more complex. Change it to a
4280 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
4281 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
4283 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
4284 || code == EQ_EXPR || code == NE_EXPR)
4285 && ((truth_value_p (TREE_CODE (arg0))
4286 && (truth_value_p (TREE_CODE (arg1))
4287 || (TREE_CODE (arg1) == BIT_AND_EXPR
4288 && integer_onep (TREE_OPERAND (arg1, 1)))))
4289 || (truth_value_p (TREE_CODE (arg1))
4290 && (truth_value_p (TREE_CODE (arg0))
4291 || (TREE_CODE (arg0) == BIT_AND_EXPR
4292 && integer_onep (TREE_OPERAND (arg0, 1)))))))
4294 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
4295 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
4299 if (code == EQ_EXPR)
4300 t = invert_truthvalue (t);
4305 if (TREE_CODE_CLASS (code) == '1')
4307 if (TREE_CODE (arg0) == COMPOUND_EXPR)
4308 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4309 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
4310 else if (TREE_CODE (arg0) == COND_EXPR)
4312 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
4313 fold (build1 (code, type, TREE_OPERAND (arg0, 1))),
4314 fold (build1 (code, type, TREE_OPERAND (arg0, 2)))));
4316 /* If this was a conversion, and all we did was to move into
4317 inside the COND_EXPR, bring it back out. But leave it if
4318 it is a conversion from integer to integer and the
4319 result precision is no wider than a word since such a
4320 conversion is cheap and may be optimized away by combine,
4321 while it couldn't if it were outside the COND_EXPR. Then return
4322 so we don't get into an infinite recursion loop taking the
4323 conversion out and then back in. */
4325 if ((code == NOP_EXPR || code == CONVERT_EXPR
4326 || code == NON_LVALUE_EXPR)
4327 && TREE_CODE (t) == COND_EXPR
4328 && TREE_CODE (TREE_OPERAND (t, 1)) == code
4329 && TREE_CODE (TREE_OPERAND (t, 2)) == code
4330 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
4331 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
4332 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
4333 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0)))
4334 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
4335 t = build1 (code, type,
4337 TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0)),
4338 TREE_OPERAND (t, 0),
4339 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
4340 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
4343 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
4344 return fold (build (COND_EXPR, type, arg0,
4345 fold (build1 (code, type, integer_one_node)),
4346 fold (build1 (code, type, integer_zero_node))));
4348 else if (TREE_CODE_CLASS (code) == '2'
4349 || TREE_CODE_CLASS (code) == '<')
4351 if (TREE_CODE (arg1) == COMPOUND_EXPR)
4352 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4353 fold (build (code, type,
4354 arg0, TREE_OPERAND (arg1, 1))));
4355 else if ((TREE_CODE (arg1) == COND_EXPR
4356 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
4357 && TREE_CODE_CLASS (code) != '<'))
4358 && (TREE_CODE (arg0) != COND_EXPR
4359 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4360 && (! TREE_SIDE_EFFECTS (arg0)
4361 || (global_bindings_p () == 0
4362 && ! contains_placeholder_p (arg0))))
4364 tree test, true_value, false_value;
4365 tree lhs = 0, rhs = 0;
4367 if (TREE_CODE (arg1) == COND_EXPR)
4369 test = TREE_OPERAND (arg1, 0);
4370 true_value = TREE_OPERAND (arg1, 1);
4371 false_value = TREE_OPERAND (arg1, 2);
4375 tree testtype = TREE_TYPE (arg1);
4377 true_value = convert (testtype, integer_one_node);
4378 false_value = convert (testtype, integer_zero_node);
4381 /* If ARG0 is complex we want to make sure we only evaluate
4382 it once. Though this is only required if it is volatile, it
4383 might be more efficient even if it is not. However, if we
4384 succeed in folding one part to a constant, we do not need
4385 to make this SAVE_EXPR. Since we do this optimization
4386 primarily to see if we do end up with constant and this
4387 SAVE_EXPR interferes with later optimizations, suppressing
4388 it when we can is important.
4390 If we are not in a function, we can't make a SAVE_EXPR, so don't
4391 try to do so. Don't try to see if the result is a constant
4392 if an arm is a COND_EXPR since we get exponential behavior
4395 if (TREE_CODE (arg0) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4396 && global_bindings_p () == 0
4397 && ((TREE_CODE (arg0) != VAR_DECL
4398 && TREE_CODE (arg0) != PARM_DECL)
4399 || TREE_SIDE_EFFECTS (arg0)))
4401 if (TREE_CODE (true_value) != COND_EXPR)
4402 lhs = fold (build (code, type, arg0, true_value));
4404 if (TREE_CODE (false_value) != COND_EXPR)
4405 rhs = fold (build (code, type, arg0, false_value));
4407 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4408 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4409 arg0 = save_expr (arg0), lhs = rhs = 0;
4413 lhs = fold (build (code, type, arg0, true_value));
4415 rhs = fold (build (code, type, arg0, false_value));
4417 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4419 if (TREE_CODE (arg0) == SAVE_EXPR)
4420 return build (COMPOUND_EXPR, type,
4421 convert (void_type_node, arg0),
4422 strip_compound_expr (test, arg0));
4424 return convert (type, test);
4427 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
4428 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4429 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4430 else if ((TREE_CODE (arg0) == COND_EXPR
4431 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
4432 && TREE_CODE_CLASS (code) != '<'))
4433 && (TREE_CODE (arg1) != COND_EXPR
4434 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4435 && (! TREE_SIDE_EFFECTS (arg1)
4436 || (global_bindings_p () == 0
4437 && ! contains_placeholder_p (arg1))))
4439 tree test, true_value, false_value;
4440 tree lhs = 0, rhs = 0;
4442 if (TREE_CODE (arg0) == COND_EXPR)
4444 test = TREE_OPERAND (arg0, 0);
4445 true_value = TREE_OPERAND (arg0, 1);
4446 false_value = TREE_OPERAND (arg0, 2);
4450 tree testtype = TREE_TYPE (arg0);
4452 true_value = convert (testtype, integer_one_node);
4453 false_value = convert (testtype, integer_zero_node);
4456 if (TREE_CODE (arg1) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4457 && global_bindings_p () == 0
4458 && ((TREE_CODE (arg1) != VAR_DECL
4459 && TREE_CODE (arg1) != PARM_DECL)
4460 || TREE_SIDE_EFFECTS (arg1)))
4462 if (TREE_CODE (true_value) != COND_EXPR)
4463 lhs = fold (build (code, type, true_value, arg1));
4465 if (TREE_CODE (false_value) != COND_EXPR)
4466 rhs = fold (build (code, type, false_value, arg1));
4468 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4469 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4470 arg1 = save_expr (arg1), lhs = rhs = 0;
4474 lhs = fold (build (code, type, true_value, arg1));
4477 rhs = fold (build (code, type, false_value, arg1));
4479 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4480 if (TREE_CODE (arg1) == SAVE_EXPR)
4481 return build (COMPOUND_EXPR, type,
4482 convert (void_type_node, arg1),
4483 strip_compound_expr (test, arg1));
4485 return convert (type, test);
4488 else if (TREE_CODE_CLASS (code) == '<'
4489 && TREE_CODE (arg0) == COMPOUND_EXPR)
4490 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4491 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4492 else if (TREE_CODE_CLASS (code) == '<'
4493 && TREE_CODE (arg1) == COMPOUND_EXPR)
4494 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4495 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
4507 return fold (DECL_INITIAL (t));
4512 case FIX_TRUNC_EXPR:
4513 /* Other kinds of FIX are not handled properly by fold_convert. */
4515 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
4516 return TREE_OPERAND (t, 0);
4518 /* Handle cases of two conversions in a row. */
4519 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
4520 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
4522 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4523 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
4524 tree final_type = TREE_TYPE (t);
4525 int inside_int = INTEGRAL_TYPE_P (inside_type);
4526 int inside_ptr = POINTER_TYPE_P (inside_type);
4527 int inside_float = FLOAT_TYPE_P (inside_type);
4528 int inside_prec = TYPE_PRECISION (inside_type);
4529 int inside_unsignedp = TREE_UNSIGNED (inside_type);
4530 int inter_int = INTEGRAL_TYPE_P (inter_type);
4531 int inter_ptr = POINTER_TYPE_P (inter_type);
4532 int inter_float = FLOAT_TYPE_P (inter_type);
4533 int inter_prec = TYPE_PRECISION (inter_type);
4534 int inter_unsignedp = TREE_UNSIGNED (inter_type);
4535 int final_int = INTEGRAL_TYPE_P (final_type);
4536 int final_ptr = POINTER_TYPE_P (final_type);
4537 int final_float = FLOAT_TYPE_P (final_type);
4538 int final_prec = TYPE_PRECISION (final_type);
4539 int final_unsignedp = TREE_UNSIGNED (final_type);
4541 /* In addition to the cases of two conversions in a row
4542 handled below, if we are converting something to its own
4543 type via an object of identical or wider precision, neither
4544 conversion is needed. */
4545 if (inside_type == final_type
4546 && ((inter_int && final_int) || (inter_float && final_float))
4547 && inter_prec >= final_prec)
4548 return TREE_OPERAND (TREE_OPERAND (t, 0), 0);
4550 /* Likewise, if the intermediate and final types are either both
4551 float or both integer, we don't need the middle conversion if
4552 it is wider than the final type and doesn't change the signedness
4553 (for integers). Avoid this if the final type is a pointer
4554 since then we sometimes need the inner conversion. Likewise if
4555 the outer has a precision not equal to the size of its mode. */
4556 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
4557 || (inter_float && inside_float))
4558 && inter_prec >= inside_prec
4559 && (inter_float || inter_unsignedp == inside_unsignedp)
4560 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
4561 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
4563 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4565 /* If we have a sign-extension of a zero-extended value, we can
4566 replace that by a single zero-extension. */
4567 if (inside_int && inter_int && final_int
4568 && inside_prec < inter_prec && inter_prec < final_prec
4569 && inside_unsignedp && !inter_unsignedp)
4570 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4572 /* Two conversions in a row are not needed unless:
4573 - some conversion is floating-point (overstrict for now), or
4574 - the intermediate type is narrower than both initial and
4576 - the intermediate type and innermost type differ in signedness,
4577 and the outermost type is wider than the intermediate, or
4578 - the initial type is a pointer type and the precisions of the
4579 intermediate and final types differ, or
4580 - the final type is a pointer type and the precisions of the
4581 initial and intermediate types differ. */
4582 if (! inside_float && ! inter_float && ! final_float
4583 && (inter_prec > inside_prec || inter_prec > final_prec)
4584 && ! (inside_int && inter_int
4585 && inter_unsignedp != inside_unsignedp
4586 && inter_prec < final_prec)
4587 && ((inter_unsignedp && inter_prec > inside_prec)
4588 == (final_unsignedp && final_prec > inter_prec))
4589 && ! (inside_ptr && inter_prec != final_prec)
4590 && ! (final_ptr && inside_prec != inter_prec)
4591 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
4592 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
4594 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4597 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
4598 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
4599 /* Detect assigning a bitfield. */
4600 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
4601 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
4603 /* Don't leave an assignment inside a conversion
4604 unless assigning a bitfield. */
4605 tree prev = TREE_OPERAND (t, 0);
4606 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
4607 /* First do the assignment, then return converted constant. */
4608 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
4614 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
4617 return fold_convert (t, arg0);
4619 #if 0 /* This loses on &"foo"[0]. */
4624 /* Fold an expression like: "foo"[2] */
4625 if (TREE_CODE (arg0) == STRING_CST
4626 && TREE_CODE (arg1) == INTEGER_CST
4627 && !TREE_INT_CST_HIGH (arg1)
4628 && (i = TREE_INT_CST_LOW (arg1)) < TREE_STRING_LENGTH (arg0))
4630 t = build_int_2 (TREE_STRING_POINTER (arg0)[i], 0);
4631 TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (arg0));
4632 force_fit_type (t, 0);
4639 if (TREE_CODE (arg0) == CONSTRUCTOR)
4641 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
4648 TREE_CONSTANT (t) = wins;
4654 if (TREE_CODE (arg0) == INTEGER_CST)
4656 HOST_WIDE_INT low, high;
4657 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
4658 TREE_INT_CST_HIGH (arg0),
4660 t = build_int_2 (low, high);
4661 TREE_TYPE (t) = type;
4663 = (TREE_OVERFLOW (arg0)
4664 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
4665 TREE_CONSTANT_OVERFLOW (t)
4666 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
4668 else if (TREE_CODE (arg0) == REAL_CST)
4669 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
4671 else if (TREE_CODE (arg0) == NEGATE_EXPR)
4672 return TREE_OPERAND (arg0, 0);
4674 /* Convert - (a - b) to (b - a) for non-floating-point. */
4675 else if (TREE_CODE (arg0) == MINUS_EXPR && ! FLOAT_TYPE_P (type))
4676 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
4677 TREE_OPERAND (arg0, 0));
4684 if (TREE_CODE (arg0) == INTEGER_CST)
4686 if (! TREE_UNSIGNED (type)
4687 && TREE_INT_CST_HIGH (arg0) < 0)
4689 HOST_WIDE_INT low, high;
4690 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
4691 TREE_INT_CST_HIGH (arg0),
4693 t = build_int_2 (low, high);
4694 TREE_TYPE (t) = type;
4696 = (TREE_OVERFLOW (arg0)
4697 | force_fit_type (t, overflow));
4698 TREE_CONSTANT_OVERFLOW (t)
4699 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
4702 else if (TREE_CODE (arg0) == REAL_CST)
4704 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
4705 t = build_real (type,
4706 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
4709 else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR)
4710 return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
4714 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
4716 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
4717 return build (COMPLEX_EXPR, TREE_TYPE (arg0),
4718 TREE_OPERAND (arg0, 0),
4719 fold (build1 (NEGATE_EXPR,
4720 TREE_TYPE (TREE_TYPE (arg0)),
4721 TREE_OPERAND (arg0, 1))));
4722 else if (TREE_CODE (arg0) == COMPLEX_CST)
4723 return build_complex (type, TREE_OPERAND (arg0, 0),
4724 fold (build1 (NEGATE_EXPR,
4725 TREE_TYPE (TREE_TYPE (arg0)),
4726 TREE_OPERAND (arg0, 1))));
4727 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
4728 return fold (build (TREE_CODE (arg0), type,
4729 fold (build1 (CONJ_EXPR, type,
4730 TREE_OPERAND (arg0, 0))),
4731 fold (build1 (CONJ_EXPR,
4732 type, TREE_OPERAND (arg0, 1)))));
4733 else if (TREE_CODE (arg0) == CONJ_EXPR)
4734 return TREE_OPERAND (arg0, 0);
4740 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
4741 ~ TREE_INT_CST_HIGH (arg0));
4742 TREE_TYPE (t) = type;
4743 force_fit_type (t, 0);
4744 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
4745 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
4747 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
4748 return TREE_OPERAND (arg0, 0);
4752 /* A + (-B) -> A - B */
4753 if (TREE_CODE (arg1) == NEGATE_EXPR)
4754 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
4755 else if (! FLOAT_TYPE_P (type))
4757 if (integer_zerop (arg1))
4758 return non_lvalue (convert (type, arg0));
4760 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
4761 with a constant, and the two constants have no bits in common,
4762 we should treat this as a BIT_IOR_EXPR since this may produce more
4764 if (TREE_CODE (arg0) == BIT_AND_EXPR
4765 && TREE_CODE (arg1) == BIT_AND_EXPR
4766 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
4767 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
4768 && integer_zerop (const_binop (BIT_AND_EXPR,
4769 TREE_OPERAND (arg0, 1),
4770 TREE_OPERAND (arg1, 1), 0)))
4772 code = BIT_IOR_EXPR;
4776 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
4777 (plus (plus (mult) (mult)) (foo)) so that we can
4778 take advantage of the factoring cases below. */
4779 if ((TREE_CODE (arg0) == PLUS_EXPR
4780 && TREE_CODE (arg1) == MULT_EXPR)
4781 || (TREE_CODE (arg1) == PLUS_EXPR
4782 && TREE_CODE (arg0) == MULT_EXPR))
4784 tree parg0, parg1, parg, marg;
4786 if (TREE_CODE (arg0) == PLUS_EXPR)
4787 parg = arg0, marg = arg1;
4789 parg = arg1, marg = arg0;
4790 parg0 = TREE_OPERAND (parg, 0);
4791 parg1 = TREE_OPERAND (parg, 1);
4795 if (TREE_CODE (parg0) == MULT_EXPR
4796 && TREE_CODE (parg1) != MULT_EXPR)
4797 return fold (build (PLUS_EXPR, type,
4798 fold (build (PLUS_EXPR, type, parg0, marg)),
4800 if (TREE_CODE (parg0) != MULT_EXPR
4801 && TREE_CODE (parg1) == MULT_EXPR)
4802 return fold (build (PLUS_EXPR, type,
4803 fold (build (PLUS_EXPR, type, parg1, marg)),
4807 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
4809 tree arg00, arg01, arg10, arg11;
4810 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
4812 /* (A * C) + (B * C) -> (A+B) * C.
4813 We are most concerned about the case where C is a constant,
4814 but other combinations show up during loop reduction. Since
4815 it is not difficult, try all four possibilities. */
4817 arg00 = TREE_OPERAND (arg0, 0);
4818 arg01 = TREE_OPERAND (arg0, 1);
4819 arg10 = TREE_OPERAND (arg1, 0);
4820 arg11 = TREE_OPERAND (arg1, 1);
4823 if (operand_equal_p (arg01, arg11, 0))
4824 same = arg01, alt0 = arg00, alt1 = arg10;
4825 else if (operand_equal_p (arg00, arg10, 0))
4826 same = arg00, alt0 = arg01, alt1 = arg11;
4827 else if (operand_equal_p (arg00, arg11, 0))
4828 same = arg00, alt0 = arg01, alt1 = arg10;
4829 else if (operand_equal_p (arg01, arg10, 0))
4830 same = arg01, alt0 = arg00, alt1 = arg11;
4832 /* No identical multiplicands; see if we can find a common
4833 power-of-two factor in non-power-of-two multiplies. This
4834 can help in multi-dimensional array access. */
4835 else if (TREE_CODE (arg01) == INTEGER_CST
4836 && TREE_CODE (arg11) == INTEGER_CST
4837 && TREE_INT_CST_HIGH (arg01) == 0
4838 && TREE_INT_CST_HIGH (arg11) == 0)
4840 HOST_WIDE_INT int01, int11, tmp;
4841 int01 = TREE_INT_CST_LOW (arg01);
4842 int11 = TREE_INT_CST_LOW (arg11);
4844 /* Move min of absolute values to int11. */
4845 if ((int01 >= 0 ? int01 : -int01)
4846 < (int11 >= 0 ? int11 : -int11))
4848 tmp = int01, int01 = int11, int11 = tmp;
4849 alt0 = arg00, arg00 = arg10, arg10 = alt0;
4850 alt0 = arg01, arg01 = arg11, arg11 = alt0;
4853 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
4855 alt0 = fold (build (MULT_EXPR, type, arg00,
4856 build_int_2 (int01 / int11, 0)));
4863 return fold (build (MULT_EXPR, type,
4864 fold (build (PLUS_EXPR, type, alt0, alt1)),
4868 /* In IEEE floating point, x+0 may not equal x. */
4869 else if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
4871 && real_zerop (arg1))
4872 return non_lvalue (convert (type, arg0));
4874 /* In most languages, can't associate operations on floats
4875 through parentheses. Rather than remember where the parentheses
4876 were, we don't associate floats at all. It shouldn't matter much.
4877 However, associating multiplications is only very slightly
4878 inaccurate, so do that if -ffast-math is specified. */
4879 if (FLOAT_TYPE_P (type)
4880 && ! (flag_fast_math && code == MULT_EXPR))
4883 /* The varsign == -1 cases happen only for addition and subtraction.
4884 It says that the arg that was split was really CON minus VAR.
4885 The rest of the code applies to all associative operations. */
4891 if (split_tree (arg0, code, &var, &con, &varsign))
4895 /* EXPR is (CON-VAR) +- ARG1. */
4896 /* If it is + and VAR==ARG1, return just CONST. */
4897 if (code == PLUS_EXPR && operand_equal_p (var, arg1, 0))
4898 return convert (TREE_TYPE (t), con);
4900 /* If ARG0 is a constant, don't change things around;
4901 instead keep all the constant computations together. */
4903 if (TREE_CONSTANT (arg0))
4906 /* Otherwise return (CON +- ARG1) - VAR. */
4907 t = build (MINUS_EXPR, type,
4908 fold (build (code, type, con, arg1)), var);
4912 /* EXPR is (VAR+CON) +- ARG1. */
4913 /* If it is - and VAR==ARG1, return just CONST. */
4914 if (code == MINUS_EXPR && operand_equal_p (var, arg1, 0))
4915 return convert (TREE_TYPE (t), con);
4917 /* If ARG0 is a constant, don't change things around;
4918 instead keep all the constant computations together. */
4920 if (TREE_CONSTANT (arg0))
4923 /* Otherwise return VAR +- (ARG1 +- CON). */
4924 tem = fold (build (code, type, arg1, con));
4925 t = build (code, type, var, tem);
4927 if (integer_zerop (tem)
4928 && (code == PLUS_EXPR || code == MINUS_EXPR))
4929 return convert (type, var);
4930 /* If we have x +/- (c - d) [c an explicit integer]
4931 change it to x -/+ (d - c) since if d is relocatable
4932 then the latter can be a single immediate insn
4933 and the former cannot. */
4934 if (TREE_CODE (tem) == MINUS_EXPR
4935 && TREE_CODE (TREE_OPERAND (tem, 0)) == INTEGER_CST)
4937 tree tem1 = TREE_OPERAND (tem, 1);
4938 TREE_OPERAND (tem, 1) = TREE_OPERAND (tem, 0);
4939 TREE_OPERAND (tem, 0) = tem1;
4941 (code == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR));
4947 if (split_tree (arg1, code, &var, &con, &varsign))
4949 if (TREE_CONSTANT (arg1))
4954 (code == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR));
4956 /* EXPR is ARG0 +- (CON +- VAR). */
4957 if (TREE_CODE (t) == MINUS_EXPR
4958 && operand_equal_p (var, arg0, 0))
4960 /* If VAR and ARG0 cancel, return just CON or -CON. */
4961 if (code == PLUS_EXPR)
4962 return convert (TREE_TYPE (t), con);
4963 return fold (build1 (NEGATE_EXPR, TREE_TYPE (t),
4964 convert (TREE_TYPE (t), con)));
4967 t = build (TREE_CODE (t), type,
4968 fold (build (code, TREE_TYPE (t), arg0, con)), var);
4970 if (integer_zerop (TREE_OPERAND (t, 0))
4971 && TREE_CODE (t) == PLUS_EXPR)
4972 return convert (TREE_TYPE (t), var);
4977 #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
4978 if (TREE_CODE (arg1) == REAL_CST)
4980 #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
4982 t1 = const_binop (code, arg0, arg1, 0);
4983 if (t1 != NULL_TREE)
4985 /* The return value should always have
4986 the same type as the original expression. */
4987 if (TREE_TYPE (t1) != TREE_TYPE (t))
4988 t1 = convert (TREE_TYPE (t), t1);
4995 if (! FLOAT_TYPE_P (type))
4997 if (! wins && integer_zerop (arg0))
4998 return build1 (NEGATE_EXPR, type, arg1);
4999 if (integer_zerop (arg1))
5000 return non_lvalue (convert (type, arg0));
5002 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5003 about the case where C is a constant, just try one of the
5004 four possibilities. */
5006 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5007 && operand_equal_p (TREE_OPERAND (arg0, 1),
5008 TREE_OPERAND (arg1, 1), 0))
5009 return fold (build (MULT_EXPR, type,
5010 fold (build (MINUS_EXPR, type,
5011 TREE_OPERAND (arg0, 0),
5012 TREE_OPERAND (arg1, 0))),
5013 TREE_OPERAND (arg0, 1)));
5015 /* Convert A - (-B) to A + B. */
5016 else if (TREE_CODE (arg1) == NEGATE_EXPR)
5017 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5019 else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5022 /* Except with IEEE floating point, 0-x equals -x. */
5023 if (! wins && real_zerop (arg0))
5024 return build1 (NEGATE_EXPR, type, arg1);
5025 /* Except with IEEE floating point, x-0 equals x. */
5026 if (real_zerop (arg1))
5027 return non_lvalue (convert (type, arg0));
5030 /* Fold &x - &x. This can happen from &x.foo - &x.
5031 This is unsafe for certain floats even in non-IEEE formats.
5032 In IEEE, it is unsafe because it does wrong for NaNs.
5033 Also note that operand_equal_p is always false if an operand
5036 if ((! FLOAT_TYPE_P (type) || flag_fast_math)
5037 && operand_equal_p (arg0, arg1, 0))
5038 return convert (type, integer_zero_node);
5043 if (! FLOAT_TYPE_P (type))
5045 if (integer_zerop (arg1))
5046 return omit_one_operand (type, arg1, arg0);
5047 if (integer_onep (arg1))
5048 return non_lvalue (convert (type, arg0));
5050 /* ((A / C) * C) is A if the division is an
5051 EXACT_DIV_EXPR. Since C is normally a constant,
5052 just check for one of the four possibilities. */
5054 if (TREE_CODE (arg0) == EXACT_DIV_EXPR
5055 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
5056 return TREE_OPERAND (arg0, 0);
5058 /* (a * (1 << b)) is (a << b) */
5059 if (TREE_CODE (arg1) == LSHIFT_EXPR
5060 && integer_onep (TREE_OPERAND (arg1, 0)))
5061 return fold (build (LSHIFT_EXPR, type, arg0,
5062 TREE_OPERAND (arg1, 1)));
5063 if (TREE_CODE (arg0) == LSHIFT_EXPR
5064 && integer_onep (TREE_OPERAND (arg0, 0)))
5065 return fold (build (LSHIFT_EXPR, type, arg1,
5066 TREE_OPERAND (arg0, 1)));
5070 /* x*0 is 0, except for IEEE floating point. */
5071 if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5073 && real_zerop (arg1))
5074 return omit_one_operand (type, arg1, arg0);
5075 /* In IEEE floating point, x*1 is not equivalent to x for snans.
5076 However, ANSI says we can drop signals,
5077 so we can do this anyway. */
5078 if (real_onep (arg1))
5079 return non_lvalue (convert (type, arg0));
5081 if (! wins && real_twop (arg1) && global_bindings_p () == 0
5082 && ! contains_placeholder_p (arg0))
5084 tree arg = save_expr (arg0);
5085 return build (PLUS_EXPR, type, arg, arg);
5093 register enum tree_code code0, code1;
5095 if (integer_all_onesp (arg1))
5096 return omit_one_operand (type, arg1, arg0);
5097 if (integer_zerop (arg1))
5098 return non_lvalue (convert (type, arg0));
5099 t1 = distribute_bit_expr (code, type, arg0, arg1);
5100 if (t1 != NULL_TREE)
5103 /* (A << C1) | (A >> C2) if A is unsigned and C1+C2 is the size of A
5104 is a rotate of A by C1 bits. */
5105 /* (A << B) | (A >> (Z - B)) if A is unsigned and Z is the size of A
5106 is a rotate of A by B bits. */
5108 code0 = TREE_CODE (arg0);
5109 code1 = TREE_CODE (arg1);
5110 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5111 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5112 && operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1,0), 0)
5113 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5115 register tree tree01, tree11;
5116 register enum tree_code code01, code11;
5118 tree01 = TREE_OPERAND (arg0, 1);
5119 tree11 = TREE_OPERAND (arg1, 1);
5120 STRIP_NOPS (tree01);
5121 STRIP_NOPS (tree11);
5122 code01 = TREE_CODE (tree01);
5123 code11 = TREE_CODE (tree11);
5124 if (code01 == INTEGER_CST
5125 && code11 == INTEGER_CST
5126 && TREE_INT_CST_HIGH (tree01) == 0
5127 && TREE_INT_CST_HIGH (tree11) == 0
5128 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5129 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5130 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5131 code0 == LSHIFT_EXPR ? tree01 : tree11);
5132 else if (code11 == MINUS_EXPR)
5134 tree tree110, tree111;
5135 tree110 = TREE_OPERAND (tree11, 0);
5136 tree111 = TREE_OPERAND (tree11, 1);
5137 STRIP_NOPS (tree110);
5138 STRIP_NOPS (tree111);
5139 if (TREE_CODE (tree110) == INTEGER_CST
5140 && TREE_INT_CST_HIGH (tree110) == 0
5141 && (TREE_INT_CST_LOW (tree110)
5142 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5143 && operand_equal_p (tree01, tree111, 0))
5144 return build ((code0 == LSHIFT_EXPR
5147 type, TREE_OPERAND (arg0, 0), tree01);
5149 else if (code01 == MINUS_EXPR)
5151 tree tree010, tree011;
5152 tree010 = TREE_OPERAND (tree01, 0);
5153 tree011 = TREE_OPERAND (tree01, 1);
5154 STRIP_NOPS (tree010);
5155 STRIP_NOPS (tree011);
5156 if (TREE_CODE (tree010) == INTEGER_CST
5157 && TREE_INT_CST_HIGH (tree010) == 0
5158 && (TREE_INT_CST_LOW (tree010)
5159 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5160 && operand_equal_p (tree11, tree011, 0))
5161 return build ((code0 != LSHIFT_EXPR
5164 type, TREE_OPERAND (arg0, 0), tree11);
5172 if (integer_zerop (arg1))
5173 return non_lvalue (convert (type, arg0));
5174 if (integer_all_onesp (arg1))
5175 return fold (build1 (BIT_NOT_EXPR, type, arg0));
5180 if (integer_all_onesp (arg1))
5181 return non_lvalue (convert (type, arg0));
5182 if (integer_zerop (arg1))
5183 return omit_one_operand (type, arg1, arg0);
5184 t1 = distribute_bit_expr (code, type, arg0, arg1);
5185 if (t1 != NULL_TREE)
5187 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5188 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == NOP_EXPR
5189 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0))))
5191 int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0)));
5192 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5193 && (~TREE_INT_CST_LOW (arg0)
5194 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5195 return build1 (NOP_EXPR, type, TREE_OPERAND (arg1, 0));
5197 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
5198 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5200 int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
5201 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5202 && (~TREE_INT_CST_LOW (arg1)
5203 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5204 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
5208 case BIT_ANDTC_EXPR:
5209 if (integer_all_onesp (arg0))
5210 return non_lvalue (convert (type, arg1));
5211 if (integer_zerop (arg0))
5212 return omit_one_operand (type, arg0, arg1);
5213 if (TREE_CODE (arg1) == INTEGER_CST)
5215 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
5216 code = BIT_AND_EXPR;
5222 /* In most cases, do nothing with a divide by zero. */
5223 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5224 #ifndef REAL_INFINITY
5225 if (TREE_CODE (arg1) == REAL_CST && real_zerop (arg1))
5228 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5230 /* In IEEE floating point, x/1 is not equivalent to x for snans.
5231 However, ANSI says we can drop signals, so we can do this anyway. */
5232 if (real_onep (arg1))
5233 return non_lvalue (convert (type, arg0));
5235 /* If ARG1 is a constant, we can convert this to a multiply by the
5236 reciprocal. This does not have the same rounding properties,
5237 so only do this if -ffast-math. We can actually always safely
5238 do it if ARG1 is a power of two, but it's hard to tell if it is
5239 or not in a portable manner. */
5240 if (TREE_CODE (arg1) == REAL_CST)
5243 && 0 != (tem = const_binop (code, build_real (type, dconst1),
5245 return fold (build (MULT_EXPR, type, arg0, tem));
5246 /* Find the reciprocal if optimizing and the result is exact. */
5250 r = TREE_REAL_CST (arg1);
5251 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
5253 tem = build_real (type, r);
5254 return fold (build (MULT_EXPR, type, arg0, tem));
5260 case TRUNC_DIV_EXPR:
5261 case ROUND_DIV_EXPR:
5262 case FLOOR_DIV_EXPR:
5264 case EXACT_DIV_EXPR:
5265 if (integer_onep (arg1))
5266 return non_lvalue (convert (type, arg0));
5267 if (integer_zerop (arg1))
5270 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
5271 operation, EXACT_DIV_EXPR.
5273 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
5274 At one time others generated faster code, it's not clear if they do
5275 after the last round to changes to the DIV code in expmed.c. */
5276 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
5277 && multiple_of_p (type, arg0, arg1))
5278 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
5280 /* If we have ((a / C1) / C2) where both division are the same type, try
5281 to simplify. First see if C1 * C2 overflows or not. */
5282 if (TREE_CODE (arg0) == code && TREE_CODE (arg1) == INTEGER_CST
5283 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5287 new_divisor = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 1), arg1, 0);
5288 tem = const_binop (FLOOR_DIV_EXPR, new_divisor, arg1, 0);
5290 if (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) == TREE_INT_CST_LOW (tem)
5291 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == TREE_INT_CST_HIGH (tem))
5293 /* If no overflow, divide by C1*C2. */
5294 return fold (build (code, type, TREE_OPERAND (arg0, 0), new_divisor));
5298 /* Look for ((a * C1) / C3) or (((a * C1) + C2) / C3),
5299 where C1 % C3 == 0 or C3 % C1 == 0. We can simplify these
5300 expressions, which often appear in the offsets or sizes of
5301 objects with a varying size. Only deal with positive divisors
5302 and multiplicands. If C2 is negative, we must have C2 % C3 == 0.
5304 Look for NOPs and SAVE_EXPRs inside. */
5306 if (TREE_CODE (arg1) == INTEGER_CST
5307 && tree_int_cst_sgn (arg1) >= 0)
5309 int have_save_expr = 0;
5310 tree c2 = integer_zero_node;
5313 if (TREE_CODE (xarg0) == SAVE_EXPR && SAVE_EXPR_RTL (xarg0) == 0)
5314 have_save_expr = 1, xarg0 = TREE_OPERAND (xarg0, 0);
5318 /* Look inside the dividend and simplify using EXACT_DIV_EXPR
5320 if (TREE_CODE (xarg0) == MULT_EXPR
5321 && multiple_of_p (type, TREE_OPERAND (xarg0, 0), arg1))
5325 t = fold (build (MULT_EXPR, type,
5326 fold (build (EXACT_DIV_EXPR, type,
5327 TREE_OPERAND (xarg0, 0), arg1)),
5328 TREE_OPERAND (xarg0, 1)));
5335 if (TREE_CODE (xarg0) == MULT_EXPR
5336 && multiple_of_p (type, TREE_OPERAND (xarg0, 1), arg1))
5340 t = fold (build (MULT_EXPR, type,
5341 fold (build (EXACT_DIV_EXPR, type,
5342 TREE_OPERAND (xarg0, 1), arg1)),
5343 TREE_OPERAND (xarg0, 0)));
5349 if (TREE_CODE (xarg0) == PLUS_EXPR
5350 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST)
5351 c2 = TREE_OPERAND (xarg0, 1), xarg0 = TREE_OPERAND (xarg0, 0);
5352 else if (TREE_CODE (xarg0) == MINUS_EXPR
5353 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5354 /* If we are doing this computation unsigned, the negate
5356 && ! TREE_UNSIGNED (type))
5358 c2 = fold (build1 (NEGATE_EXPR, type, TREE_OPERAND (xarg0, 1)));
5359 xarg0 = TREE_OPERAND (xarg0, 0);
5362 if (TREE_CODE (xarg0) == SAVE_EXPR && SAVE_EXPR_RTL (xarg0) == 0)
5363 have_save_expr = 1, xarg0 = TREE_OPERAND (xarg0, 0);
5367 if (TREE_CODE (xarg0) == MULT_EXPR
5368 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5369 && tree_int_cst_sgn (TREE_OPERAND (xarg0, 1)) >= 0
5370 && (integer_zerop (const_binop (TRUNC_MOD_EXPR,
5371 TREE_OPERAND (xarg0, 1), arg1, 1))
5372 || integer_zerop (const_binop (TRUNC_MOD_EXPR, arg1,
5373 TREE_OPERAND (xarg0, 1), 1)))
5374 && (tree_int_cst_sgn (c2) >= 0
5375 || integer_zerop (const_binop (TRUNC_MOD_EXPR, c2,
5378 tree outer_div = integer_one_node;
5379 tree c1 = TREE_OPERAND (xarg0, 1);
5382 /* If C3 > C1, set them equal and do a divide by
5383 C3/C1 at the end of the operation. */
5384 if (tree_int_cst_lt (c1, c3))
5385 outer_div = const_binop (code, c3, c1, 0), c3 = c1;
5387 /* The result is A * (C1/C3) + (C2/C3). */
5388 t = fold (build (PLUS_EXPR, type,
5389 fold (build (MULT_EXPR, type,
5390 TREE_OPERAND (xarg0, 0),
5391 const_binop (code, c1, c3, 1))),
5392 const_binop (code, c2, c3, 1)));
5394 if (! integer_onep (outer_div))
5395 t = fold (build (code, type, t, convert (type, outer_div)));
5407 case FLOOR_MOD_EXPR:
5408 case ROUND_MOD_EXPR:
5409 case TRUNC_MOD_EXPR:
5410 if (integer_onep (arg1))
5411 return omit_one_operand (type, integer_zero_node, arg0);
5412 if (integer_zerop (arg1))
5415 /* Look for ((a * C1) % C3) or (((a * C1) + C2) % C3),
5416 where C1 % C3 == 0. Handle similarly to the division case,
5417 but don't bother with SAVE_EXPRs. */
5419 if (TREE_CODE (arg1) == INTEGER_CST
5420 && ! integer_zerop (arg1))
5422 tree c2 = integer_zero_node;
5425 if (TREE_CODE (xarg0) == PLUS_EXPR
5426 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST)
5427 c2 = TREE_OPERAND (xarg0, 1), xarg0 = TREE_OPERAND (xarg0, 0);
5428 else if (TREE_CODE (xarg0) == MINUS_EXPR
5429 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5430 && ! TREE_UNSIGNED (type))
5432 c2 = fold (build1 (NEGATE_EXPR, type, TREE_OPERAND (xarg0, 1)));
5433 xarg0 = TREE_OPERAND (xarg0, 0);
5438 if (TREE_CODE (xarg0) == MULT_EXPR
5439 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5440 && integer_zerop (const_binop (TRUNC_MOD_EXPR,
5441 TREE_OPERAND (xarg0, 1),
5443 && tree_int_cst_sgn (c2) >= 0)
5444 /* The result is (C2%C3). */
5445 return omit_one_operand (type, const_binop (code, c2, arg1, 1),
5446 TREE_OPERAND (xarg0, 0));
5455 if (integer_zerop (arg1))
5456 return non_lvalue (convert (type, arg0));
5457 /* Since negative shift count is not well-defined,
5458 don't try to compute it in the compiler. */
5459 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
5461 /* Rewrite an LROTATE_EXPR by a constant into an
5462 RROTATE_EXPR by a new constant. */
5463 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
5465 TREE_SET_CODE (t, RROTATE_EXPR);
5466 code = RROTATE_EXPR;
5467 TREE_OPERAND (t, 1) = arg1
5470 convert (TREE_TYPE (arg1),
5471 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
5473 if (tree_int_cst_sgn (arg1) < 0)
5477 /* If we have a rotate of a bit operation with the rotate count and
5478 the second operand of the bit operation both constant,
5479 permute the two operations. */
5480 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5481 && (TREE_CODE (arg0) == BIT_AND_EXPR
5482 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
5483 || TREE_CODE (arg0) == BIT_IOR_EXPR
5484 || TREE_CODE (arg0) == BIT_XOR_EXPR)
5485 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5486 return fold (build (TREE_CODE (arg0), type,
5487 fold (build (code, type,
5488 TREE_OPERAND (arg0, 0), arg1)),
5489 fold (build (code, type,
5490 TREE_OPERAND (arg0, 1), arg1))));
5492 /* Two consecutive rotates adding up to the width of the mode can
5494 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5495 && TREE_CODE (arg0) == RROTATE_EXPR
5496 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5497 && TREE_INT_CST_HIGH (arg1) == 0
5498 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
5499 && ((TREE_INT_CST_LOW (arg1)
5500 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
5501 == GET_MODE_BITSIZE (TYPE_MODE (type))))
5502 return TREE_OPERAND (arg0, 0);
5507 if (operand_equal_p (arg0, arg1, 0))
5509 if (INTEGRAL_TYPE_P (type)
5510 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
5511 return omit_one_operand (type, arg1, arg0);
5515 if (operand_equal_p (arg0, arg1, 0))
5517 if (INTEGRAL_TYPE_P (type)
5518 && TYPE_MAX_VALUE (type)
5519 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
5520 return omit_one_operand (type, arg1, arg0);
5523 case TRUTH_NOT_EXPR:
5524 /* Note that the operand of this must be an int
5525 and its values must be 0 or 1.
5526 ("true" is a fixed value perhaps depending on the language,
5527 but we don't handle values other than 1 correctly yet.) */
5528 tem = invert_truthvalue (arg0);
5529 /* Avoid infinite recursion. */
5530 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
5532 return convert (type, tem);
5534 case TRUTH_ANDIF_EXPR:
5535 /* Note that the operands of this must be ints
5536 and their values must be 0 or 1.
5537 ("true" is a fixed value perhaps depending on the language.) */
5538 /* If first arg is constant zero, return it. */
5539 if (integer_zerop (arg0))
5541 case TRUTH_AND_EXPR:
5542 /* If either arg is constant true, drop it. */
5543 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5544 return non_lvalue (arg1);
5545 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5546 return non_lvalue (arg0);
5547 /* If second arg is constant zero, result is zero, but first arg
5548 must be evaluated. */
5549 if (integer_zerop (arg1))
5550 return omit_one_operand (type, arg1, arg0);
5551 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
5552 case will be handled here. */
5553 if (integer_zerop (arg0))
5554 return omit_one_operand (type, arg0, arg1);
5557 /* We only do these simplifications if we are optimizing. */
5561 /* Check for things like (A || B) && (A || C). We can convert this
5562 to A || (B && C). Note that either operator can be any of the four
5563 truth and/or operations and the transformation will still be
5564 valid. Also note that we only care about order for the
5565 ANDIF and ORIF operators. If B contains side effects, this
5566 might change the truth-value of A. */
5567 if (TREE_CODE (arg0) == TREE_CODE (arg1)
5568 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
5569 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
5570 || TREE_CODE (arg0) == TRUTH_AND_EXPR
5571 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
5572 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
5574 tree a00 = TREE_OPERAND (arg0, 0);
5575 tree a01 = TREE_OPERAND (arg0, 1);
5576 tree a10 = TREE_OPERAND (arg1, 0);
5577 tree a11 = TREE_OPERAND (arg1, 1);
5578 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
5579 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
5580 && (code == TRUTH_AND_EXPR
5581 || code == TRUTH_OR_EXPR));
5583 if (operand_equal_p (a00, a10, 0))
5584 return fold (build (TREE_CODE (arg0), type, a00,
5585 fold (build (code, type, a01, a11))));
5586 else if (commutative && operand_equal_p (a00, a11, 0))
5587 return fold (build (TREE_CODE (arg0), type, a00,
5588 fold (build (code, type, a01, a10))));
5589 else if (commutative && operand_equal_p (a01, a10, 0))
5590 return fold (build (TREE_CODE (arg0), type, a01,
5591 fold (build (code, type, a00, a11))));
5593 /* This case if tricky because we must either have commutative
5594 operators or else A10 must not have side-effects. */
5596 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
5597 && operand_equal_p (a01, a11, 0))
5598 return fold (build (TREE_CODE (arg0), type,
5599 fold (build (code, type, a00, a10)),
5603 /* See if we can build a range comparison. */
5604 if (0 != (tem = fold_range_test (t)))
5607 /* Check for the possibility of merging component references. If our
5608 lhs is another similar operation, try to merge its rhs with our
5609 rhs. Then try to merge our lhs and rhs. */
5610 if (TREE_CODE (arg0) == code
5611 && 0 != (tem = fold_truthop (code, type,
5612 TREE_OPERAND (arg0, 1), arg1)))
5613 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
5615 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
5620 case TRUTH_ORIF_EXPR:
5621 /* Note that the operands of this must be ints
5622 and their values must be 0 or true.
5623 ("true" is a fixed value perhaps depending on the language.) */
5624 /* If first arg is constant true, return it. */
5625 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5628 /* If either arg is constant zero, drop it. */
5629 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
5630 return non_lvalue (arg1);
5631 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1))
5632 return non_lvalue (arg0);
5633 /* If second arg is constant true, result is true, but we must
5634 evaluate first arg. */
5635 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5636 return omit_one_operand (type, arg1, arg0);
5637 /* Likewise for first arg, but note this only occurs here for
5639 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5640 return omit_one_operand (type, arg0, arg1);
5643 case TRUTH_XOR_EXPR:
5644 /* If either arg is constant zero, drop it. */
5645 if (integer_zerop (arg0))
5646 return non_lvalue (arg1);
5647 if (integer_zerop (arg1))
5648 return non_lvalue (arg0);
5649 /* If either arg is constant true, this is a logical inversion. */
5650 if (integer_onep (arg0))
5651 return non_lvalue (invert_truthvalue (arg1));
5652 if (integer_onep (arg1))
5653 return non_lvalue (invert_truthvalue (arg0));
5662 /* If one arg is a constant integer, put it last. */
5663 if (TREE_CODE (arg0) == INTEGER_CST
5664 && TREE_CODE (arg1) != INTEGER_CST)
5666 TREE_OPERAND (t, 0) = arg1;
5667 TREE_OPERAND (t, 1) = arg0;
5668 arg0 = TREE_OPERAND (t, 0);
5669 arg1 = TREE_OPERAND (t, 1);
5670 code = swap_tree_comparison (code);
5671 TREE_SET_CODE (t, code);
5674 /* Convert foo++ == CONST into ++foo == CONST + INCR.
5675 First, see if one arg is constant; find the constant arg
5676 and the other one. */
5678 tree constop = 0, varop = NULL_TREE;
5679 int constopnum = -1;
5681 if (TREE_CONSTANT (arg1))
5682 constopnum = 1, constop = arg1, varop = arg0;
5683 if (TREE_CONSTANT (arg0))
5684 constopnum = 0, constop = arg0, varop = arg1;
5686 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
5688 /* This optimization is invalid for ordered comparisons
5689 if CONST+INCR overflows or if foo+incr might overflow.
5690 This optimization is invalid for floating point due to rounding.
5691 For pointer types we assume overflow doesn't happen. */
5692 if (POINTER_TYPE_P (TREE_TYPE (varop))
5693 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
5694 && (code == EQ_EXPR || code == NE_EXPR)))
5697 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
5698 constop, TREE_OPERAND (varop, 1)));
5699 TREE_SET_CODE (varop, PREINCREMENT_EXPR);
5701 /* If VAROP is a reference to a bitfield, we must mask
5702 the constant by the width of the field. */
5703 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
5704 && DECL_BIT_FIELD(TREE_OPERAND
5705 (TREE_OPERAND (varop, 0), 1)))
5708 = TREE_INT_CST_LOW (DECL_SIZE
5710 (TREE_OPERAND (varop, 0), 1)));
5711 tree mask, unsigned_type;
5713 tree folded_compare;
5715 /* First check whether the comparison would come out
5716 always the same. If we don't do that we would
5717 change the meaning with the masking. */
5718 if (constopnum == 0)
5719 folded_compare = fold (build (code, type, constop,
5720 TREE_OPERAND (varop, 0)));
5722 folded_compare = fold (build (code, type,
5723 TREE_OPERAND (varop, 0),
5725 if (integer_zerop (folded_compare)
5726 || integer_onep (folded_compare))
5727 return omit_one_operand (type, folded_compare, varop);
5729 unsigned_type = type_for_size (size, 1);
5730 precision = TYPE_PRECISION (unsigned_type);
5731 mask = build_int_2 (~0, ~0);
5732 TREE_TYPE (mask) = unsigned_type;
5733 force_fit_type (mask, 0);
5734 mask = const_binop (RSHIFT_EXPR, mask,
5735 size_int (precision - size), 0);
5736 newconst = fold (build (BIT_AND_EXPR,
5737 TREE_TYPE (varop), newconst,
5738 convert (TREE_TYPE (varop),
5743 t = build (code, type, TREE_OPERAND (t, 0),
5744 TREE_OPERAND (t, 1));
5745 TREE_OPERAND (t, constopnum) = newconst;
5749 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
5751 if (POINTER_TYPE_P (TREE_TYPE (varop))
5752 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
5753 && (code == EQ_EXPR || code == NE_EXPR)))
5756 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
5757 constop, TREE_OPERAND (varop, 1)));
5758 TREE_SET_CODE (varop, PREDECREMENT_EXPR);
5760 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
5761 && DECL_BIT_FIELD(TREE_OPERAND
5762 (TREE_OPERAND (varop, 0), 1)))
5765 = TREE_INT_CST_LOW (DECL_SIZE
5767 (TREE_OPERAND (varop, 0), 1)));
5768 tree mask, unsigned_type;
5770 tree folded_compare;
5772 if (constopnum == 0)
5773 folded_compare = fold (build (code, type, constop,
5774 TREE_OPERAND (varop, 0)));
5776 folded_compare = fold (build (code, type,
5777 TREE_OPERAND (varop, 0),
5779 if (integer_zerop (folded_compare)
5780 || integer_onep (folded_compare))
5781 return omit_one_operand (type, folded_compare, varop);
5783 unsigned_type = type_for_size (size, 1);
5784 precision = TYPE_PRECISION (unsigned_type);
5785 mask = build_int_2 (~0, ~0);
5786 TREE_TYPE (mask) = TREE_TYPE (varop);
5787 force_fit_type (mask, 0);
5788 mask = const_binop (RSHIFT_EXPR, mask,
5789 size_int (precision - size), 0);
5790 newconst = fold (build (BIT_AND_EXPR,
5791 TREE_TYPE (varop), newconst,
5792 convert (TREE_TYPE (varop),
5797 t = build (code, type, TREE_OPERAND (t, 0),
5798 TREE_OPERAND (t, 1));
5799 TREE_OPERAND (t, constopnum) = newconst;
5805 /* Change X >= CST to X > (CST - 1) if CST is positive. */
5806 if (TREE_CODE (arg1) == INTEGER_CST
5807 && TREE_CODE (arg0) != INTEGER_CST
5808 && tree_int_cst_sgn (arg1) > 0)
5810 switch (TREE_CODE (t))
5814 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
5815 t = build (code, type, TREE_OPERAND (t, 0), arg1);
5820 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
5821 t = build (code, type, TREE_OPERAND (t, 0), arg1);
5829 /* If this is an EQ or NE comparison with zero and ARG0 is
5830 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
5831 two operations, but the latter can be done in one less insn
5832 on machines that have only two-operand insns or on which a
5833 constant cannot be the first operand. */
5834 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
5835 && TREE_CODE (arg0) == BIT_AND_EXPR)
5837 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
5838 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
5840 fold (build (code, type,
5841 build (BIT_AND_EXPR, TREE_TYPE (arg0),
5843 TREE_TYPE (TREE_OPERAND (arg0, 0)),
5844 TREE_OPERAND (arg0, 1),
5845 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
5846 convert (TREE_TYPE (arg0),
5849 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
5850 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
5852 fold (build (code, type,
5853 build (BIT_AND_EXPR, TREE_TYPE (arg0),
5855 TREE_TYPE (TREE_OPERAND (arg0, 1)),
5856 TREE_OPERAND (arg0, 0),
5857 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
5858 convert (TREE_TYPE (arg0),
5863 /* If this is an NE or EQ comparison of zero against the result of a
5864 signed MOD operation whose second operand is a power of 2, make
5865 the MOD operation unsigned since it is simpler and equivalent. */
5866 if ((code == NE_EXPR || code == EQ_EXPR)
5867 && integer_zerop (arg1)
5868 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
5869 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
5870 || TREE_CODE (arg0) == CEIL_MOD_EXPR
5871 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
5872 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
5873 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5875 tree newtype = unsigned_type (TREE_TYPE (arg0));
5876 tree newmod = build (TREE_CODE (arg0), newtype,
5877 convert (newtype, TREE_OPERAND (arg0, 0)),
5878 convert (newtype, TREE_OPERAND (arg0, 1)));
5880 return build (code, type, newmod, convert (newtype, arg1));
5883 /* If this is an NE comparison of zero with an AND of one, remove the
5884 comparison since the AND will give the correct value. */
5885 if (code == NE_EXPR && integer_zerop (arg1)
5886 && TREE_CODE (arg0) == BIT_AND_EXPR
5887 && integer_onep (TREE_OPERAND (arg0, 1)))
5888 return convert (type, arg0);
5890 /* If we have (A & C) == C where C is a power of 2, convert this into
5891 (A & C) != 0. Similarly for NE_EXPR. */
5892 if ((code == EQ_EXPR || code == NE_EXPR)
5893 && TREE_CODE (arg0) == BIT_AND_EXPR
5894 && integer_pow2p (TREE_OPERAND (arg0, 1))
5895 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
5896 return build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
5897 arg0, integer_zero_node);
5899 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
5900 and similarly for >= into !=. */
5901 if ((code == LT_EXPR || code == GE_EXPR)
5902 && TREE_UNSIGNED (TREE_TYPE (arg0))
5903 && TREE_CODE (arg1) == LSHIFT_EXPR
5904 && integer_onep (TREE_OPERAND (arg1, 0)))
5905 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
5906 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
5907 TREE_OPERAND (arg1, 1)),
5908 convert (TREE_TYPE (arg0), integer_zero_node));
5910 else if ((code == LT_EXPR || code == GE_EXPR)
5911 && TREE_UNSIGNED (TREE_TYPE (arg0))
5912 && (TREE_CODE (arg1) == NOP_EXPR
5913 || TREE_CODE (arg1) == CONVERT_EXPR)
5914 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
5915 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
5917 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
5918 convert (TREE_TYPE (arg0),
5919 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
5920 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
5921 convert (TREE_TYPE (arg0), integer_zero_node));
5923 /* Simplify comparison of something with itself. (For IEEE
5924 floating-point, we can only do some of these simplifications.) */
5925 if (operand_equal_p (arg0, arg1, 0))
5932 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
5933 return constant_boolean_node (1, type);
5935 TREE_SET_CODE (t, code);
5939 /* For NE, we can only do this simplification if integer. */
5940 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
5942 /* ... fall through ... */
5945 return constant_boolean_node (0, type);
5951 /* An unsigned comparison against 0 can be simplified. */
5952 if (integer_zerop (arg1)
5953 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
5954 || POINTER_TYPE_P (TREE_TYPE (arg1)))
5955 && TREE_UNSIGNED (TREE_TYPE (arg1)))
5957 switch (TREE_CODE (t))
5961 TREE_SET_CODE (t, NE_EXPR);
5965 TREE_SET_CODE (t, EQ_EXPR);
5968 return omit_one_operand (type,
5969 convert (type, integer_one_node),
5972 return omit_one_operand (type,
5973 convert (type, integer_zero_node),
5980 /* An unsigned <= 0x7fffffff can be simplified. */
5982 int width = TYPE_PRECISION (TREE_TYPE (arg1));
5983 if (TREE_CODE (arg1) == INTEGER_CST
5984 && ! TREE_CONSTANT_OVERFLOW (arg1)
5985 && width <= HOST_BITS_PER_WIDE_INT
5986 && TREE_INT_CST_LOW (arg1) == ((HOST_WIDE_INT) 1 << (width - 1)) - 1
5987 && TREE_INT_CST_HIGH (arg1) == 0
5988 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
5989 || POINTER_TYPE_P (TREE_TYPE (arg1)))
5990 && TREE_UNSIGNED (TREE_TYPE (arg1)))
5992 switch (TREE_CODE (t))
5995 return fold (build (GE_EXPR, type,
5996 convert (signed_type (TREE_TYPE (arg0)),
5998 convert (signed_type (TREE_TYPE (arg1)),
5999 integer_zero_node)));
6001 return fold (build (LT_EXPR, type,
6002 convert (signed_type (TREE_TYPE (arg0)),
6004 convert (signed_type (TREE_TYPE (arg1)),
6005 integer_zero_node)));
6012 /* If we are comparing an expression that just has comparisons
6013 of two integer values, arithmetic expressions of those comparisons,
6014 and constants, we can simplify it. There are only three cases
6015 to check: the two values can either be equal, the first can be
6016 greater, or the second can be greater. Fold the expression for
6017 those three values. Since each value must be 0 or 1, we have
6018 eight possibilities, each of which corresponds to the constant 0
6019 or 1 or one of the six possible comparisons.
6021 This handles common cases like (a > b) == 0 but also handles
6022 expressions like ((x > y) - (y > x)) > 0, which supposedly
6023 occur in macroized code. */
6025 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
6027 tree cval1 = 0, cval2 = 0;
6030 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
6031 /* Don't handle degenerate cases here; they should already
6032 have been handled anyway. */
6033 && cval1 != 0 && cval2 != 0
6034 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
6035 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
6036 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
6037 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
6038 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
6039 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
6040 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
6042 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
6043 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
6045 /* We can't just pass T to eval_subst in case cval1 or cval2
6046 was the same as ARG1. */
6049 = fold (build (code, type,
6050 eval_subst (arg0, cval1, maxval, cval2, minval),
6053 = fold (build (code, type,
6054 eval_subst (arg0, cval1, maxval, cval2, maxval),
6057 = fold (build (code, type,
6058 eval_subst (arg0, cval1, minval, cval2, maxval),
6061 /* All three of these results should be 0 or 1. Confirm they
6062 are. Then use those values to select the proper code
6065 if ((integer_zerop (high_result)
6066 || integer_onep (high_result))
6067 && (integer_zerop (equal_result)
6068 || integer_onep (equal_result))
6069 && (integer_zerop (low_result)
6070 || integer_onep (low_result)))
6072 /* Make a 3-bit mask with the high-order bit being the
6073 value for `>', the next for '=', and the low for '<'. */
6074 switch ((integer_onep (high_result) * 4)
6075 + (integer_onep (equal_result) * 2)
6076 + integer_onep (low_result))
6080 return omit_one_operand (type, integer_zero_node, arg0);
6101 return omit_one_operand (type, integer_one_node, arg0);
6104 t = build (code, type, cval1, cval2);
6106 return save_expr (t);
6113 /* If this is a comparison of a field, we may be able to simplify it. */
6114 if ((TREE_CODE (arg0) == COMPONENT_REF
6115 || TREE_CODE (arg0) == BIT_FIELD_REF)
6116 && (code == EQ_EXPR || code == NE_EXPR)
6117 /* Handle the constant case even without -O
6118 to make sure the warnings are given. */
6119 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
6121 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
6125 /* If this is a comparison of complex values and either or both sides
6126 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6127 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6128 This may prevent needless evaluations. */
6129 if ((code == EQ_EXPR || code == NE_EXPR)
6130 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
6131 && (TREE_CODE (arg0) == COMPLEX_EXPR
6132 || TREE_CODE (arg1) == COMPLEX_EXPR
6133 || TREE_CODE (arg0) == COMPLEX_CST
6134 || TREE_CODE (arg1) == COMPLEX_CST))
6136 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
6137 tree real0, imag0, real1, imag1;
6139 arg0 = save_expr (arg0);
6140 arg1 = save_expr (arg1);
6141 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
6142 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
6143 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
6144 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
6146 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
6149 fold (build (code, type, real0, real1)),
6150 fold (build (code, type, imag0, imag1))));
6153 /* From here on, the only cases we handle are when the result is
6154 known to be a constant.
6156 To compute GT, swap the arguments and do LT.
6157 To compute GE, do LT and invert the result.
6158 To compute LE, swap the arguments, do LT and invert the result.
6159 To compute NE, do EQ and invert the result.
6161 Therefore, the code below must handle only EQ and LT. */
6163 if (code == LE_EXPR || code == GT_EXPR)
6165 tem = arg0, arg0 = arg1, arg1 = tem;
6166 code = swap_tree_comparison (code);
6169 /* Note that it is safe to invert for real values here because we
6170 will check below in the one case that it matters. */
6173 if (code == NE_EXPR || code == GE_EXPR)
6176 code = invert_tree_comparison (code);
6179 /* Compute a result for LT or EQ if args permit;
6180 otherwise return T. */
6181 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
6183 if (code == EQ_EXPR)
6184 t1 = build_int_2 ((TREE_INT_CST_LOW (arg0)
6185 == TREE_INT_CST_LOW (arg1))
6186 && (TREE_INT_CST_HIGH (arg0)
6187 == TREE_INT_CST_HIGH (arg1)),
6190 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
6191 ? INT_CST_LT_UNSIGNED (arg0, arg1)
6192 : INT_CST_LT (arg0, arg1)),
6196 #if 0 /* This is no longer useful, but breaks some real code. */
6197 /* Assume a nonexplicit constant cannot equal an explicit one,
6198 since such code would be undefined anyway.
6199 Exception: on sysvr4, using #pragma weak,
6200 a label can come out as 0. */
6201 else if (TREE_CODE (arg1) == INTEGER_CST
6202 && !integer_zerop (arg1)
6203 && TREE_CONSTANT (arg0)
6204 && TREE_CODE (arg0) == ADDR_EXPR
6206 t1 = build_int_2 (0, 0);
6208 /* Two real constants can be compared explicitly. */
6209 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
6211 /* If either operand is a NaN, the result is false with two
6212 exceptions: First, an NE_EXPR is true on NaNs, but that case
6213 is already handled correctly since we will be inverting the
6214 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6215 or a GE_EXPR into a LT_EXPR, we must return true so that it
6216 will be inverted into false. */
6218 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
6219 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
6220 t1 = build_int_2 (invert && code == LT_EXPR, 0);
6222 else if (code == EQ_EXPR)
6223 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
6224 TREE_REAL_CST (arg1)),
6227 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
6228 TREE_REAL_CST (arg1)),
6232 if (t1 == NULL_TREE)
6236 TREE_INT_CST_LOW (t1) ^= 1;
6238 TREE_TYPE (t1) = type;
6239 if (TREE_CODE (type) == BOOLEAN_TYPE)
6240 return truthvalue_conversion (t1);
6244 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
6245 so all simple results must be passed through pedantic_non_lvalue. */
6246 if (TREE_CODE (arg0) == INTEGER_CST)
6247 return pedantic_non_lvalue
6248 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
6249 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
6250 return pedantic_omit_one_operand (type, arg1, arg0);
6252 /* If the second operand is zero, invert the comparison and swap
6253 the second and third operands. Likewise if the second operand
6254 is constant and the third is not or if the third operand is
6255 equivalent to the first operand of the comparison. */
6257 if (integer_zerop (arg1)
6258 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
6259 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6260 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6261 TREE_OPERAND (t, 2),
6262 TREE_OPERAND (arg0, 1))))
6264 /* See if this can be inverted. If it can't, possibly because
6265 it was a floating-point inequality comparison, don't do
6267 tem = invert_truthvalue (arg0);
6269 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6271 t = build (code, type, tem,
6272 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6274 /* arg1 should be the first argument of the new T. */
6275 arg1 = TREE_OPERAND (t, 1);
6280 /* If we have A op B ? A : C, we may be able to convert this to a
6281 simpler expression, depending on the operation and the values
6282 of B and C. IEEE floating point prevents this though,
6283 because A or B might be -0.0 or a NaN. */
6285 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6286 && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
6287 || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0)))
6289 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6290 arg1, TREE_OPERAND (arg0, 1)))
6292 tree arg2 = TREE_OPERAND (t, 2);
6293 enum tree_code comp_code = TREE_CODE (arg0);
6297 /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
6298 depending on the comparison operation. */
6299 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
6300 ? real_zerop (TREE_OPERAND (arg0, 1))
6301 : integer_zerop (TREE_OPERAND (arg0, 1)))
6302 && TREE_CODE (arg2) == NEGATE_EXPR
6303 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
6307 return pedantic_non_lvalue
6308 (fold (build1 (NEGATE_EXPR, type, arg1)));
6310 return pedantic_non_lvalue (convert (type, arg1));
6313 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6314 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6315 return pedantic_non_lvalue
6316 (convert (type, fold (build1 (ABS_EXPR,
6317 TREE_TYPE (arg1), arg1))));
6320 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6321 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6322 return pedantic_non_lvalue
6323 (fold (build1 (NEGATE_EXPR, type,
6325 fold (build1 (ABS_EXPR,
6332 /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
6335 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
6337 if (comp_code == NE_EXPR)
6338 return pedantic_non_lvalue (convert (type, arg1));
6339 else if (comp_code == EQ_EXPR)
6340 return pedantic_non_lvalue (convert (type, integer_zero_node));
6343 /* If this is A op B ? A : B, this is either A, B, min (A, B),
6344 or max (A, B), depending on the operation. */
6346 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
6347 arg2, TREE_OPERAND (arg0, 0)))
6349 tree comp_op0 = TREE_OPERAND (arg0, 0);
6350 tree comp_op1 = TREE_OPERAND (arg0, 1);
6351 tree comp_type = TREE_TYPE (comp_op0);
6356 return pedantic_non_lvalue (convert (type, arg2));
6358 return pedantic_non_lvalue (convert (type, arg1));
6361 /* In C++ a ?: expression can be an lvalue, so put the
6362 operand which will be used if they are equal first
6363 so that we can convert this back to the
6364 corresponding COND_EXPR. */
6365 return pedantic_non_lvalue
6366 (convert (type, (fold (build (MIN_EXPR, comp_type,
6367 (comp_code == LE_EXPR
6368 ? comp_op0 : comp_op1),
6369 (comp_code == LE_EXPR
6370 ? comp_op1 : comp_op0))))));
6374 return pedantic_non_lvalue
6375 (convert (type, fold (build (MAX_EXPR, comp_type,
6376 (comp_code == GE_EXPR
6377 ? comp_op0 : comp_op1),
6378 (comp_code == GE_EXPR
6379 ? comp_op1 : comp_op0)))));
6386 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
6387 we might still be able to simplify this. For example,
6388 if C1 is one less or one more than C2, this might have started
6389 out as a MIN or MAX and been transformed by this function.
6390 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
6392 if (INTEGRAL_TYPE_P (type)
6393 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6394 && TREE_CODE (arg2) == INTEGER_CST)
6398 /* We can replace A with C1 in this case. */
6399 arg1 = convert (type, TREE_OPERAND (arg0, 1));
6400 t = build (code, type, TREE_OPERAND (t, 0), arg1,
6401 TREE_OPERAND (t, 2));
6405 /* If C1 is C2 + 1, this is min(A, C2). */
6406 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6407 && operand_equal_p (TREE_OPERAND (arg0, 1),
6408 const_binop (PLUS_EXPR, arg2,
6409 integer_one_node, 0), 1))
6410 return pedantic_non_lvalue
6411 (fold (build (MIN_EXPR, type, arg1, arg2)));
6415 /* If C1 is C2 - 1, this is min(A, C2). */
6416 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6417 && operand_equal_p (TREE_OPERAND (arg0, 1),
6418 const_binop (MINUS_EXPR, arg2,
6419 integer_one_node, 0), 1))
6420 return pedantic_non_lvalue
6421 (fold (build (MIN_EXPR, type, arg1, arg2)));
6425 /* If C1 is C2 - 1, this is max(A, C2). */
6426 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6427 && operand_equal_p (TREE_OPERAND (arg0, 1),
6428 const_binop (MINUS_EXPR, arg2,
6429 integer_one_node, 0), 1))
6430 return pedantic_non_lvalue
6431 (fold (build (MAX_EXPR, type, arg1, arg2)));
6435 /* If C1 is C2 + 1, this is max(A, C2). */
6436 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6437 && operand_equal_p (TREE_OPERAND (arg0, 1),
6438 const_binop (PLUS_EXPR, arg2,
6439 integer_one_node, 0), 1))
6440 return pedantic_non_lvalue
6441 (fold (build (MAX_EXPR, type, arg1, arg2)));
6450 /* If the second operand is simpler than the third, swap them
6451 since that produces better jump optimization results. */
6452 if ((TREE_CONSTANT (arg1) || TREE_CODE_CLASS (TREE_CODE (arg1)) == 'd'
6453 || TREE_CODE (arg1) == SAVE_EXPR)
6454 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
6455 || TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (t, 2))) == 'd'
6456 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
6458 /* See if this can be inverted. If it can't, possibly because
6459 it was a floating-point inequality comparison, don't do
6461 tem = invert_truthvalue (arg0);
6463 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6465 t = build (code, type, tem,
6466 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6468 /* arg1 should be the first argument of the new T. */
6469 arg1 = TREE_OPERAND (t, 1);
6474 /* Convert A ? 1 : 0 to simply A. */
6475 if (integer_onep (TREE_OPERAND (t, 1))
6476 && integer_zerop (TREE_OPERAND (t, 2))
6477 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
6478 call to fold will try to move the conversion inside
6479 a COND, which will recurse. In that case, the COND_EXPR
6480 is probably the best choice, so leave it alone. */
6481 && type == TREE_TYPE (arg0))
6482 return pedantic_non_lvalue (arg0);
6484 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
6485 operation is simply A & 2. */
6487 if (integer_zerop (TREE_OPERAND (t, 2))
6488 && TREE_CODE (arg0) == NE_EXPR
6489 && integer_zerop (TREE_OPERAND (arg0, 1))
6490 && integer_pow2p (arg1)
6491 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
6492 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
6494 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
6499 /* When pedantic, a compound expression can be neither an lvalue
6500 nor an integer constant expression. */
6501 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
6503 /* Don't let (0, 0) be null pointer constant. */
6504 if (integer_zerop (arg1))
6505 return build1 (NOP_EXPR, TREE_TYPE (arg1), arg1);
6510 return build_complex (type, arg0, arg1);
6514 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6516 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6517 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
6518 TREE_OPERAND (arg0, 1));
6519 else if (TREE_CODE (arg0) == COMPLEX_CST)
6520 return TREE_REALPART (arg0);
6521 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6522 return fold (build (TREE_CODE (arg0), type,
6523 fold (build1 (REALPART_EXPR, type,
6524 TREE_OPERAND (arg0, 0))),
6525 fold (build1 (REALPART_EXPR,
6526 type, TREE_OPERAND (arg0, 1)))));
6530 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6531 return convert (type, integer_zero_node);
6532 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6533 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
6534 TREE_OPERAND (arg0, 0));
6535 else if (TREE_CODE (arg0) == COMPLEX_CST)
6536 return TREE_IMAGPART (arg0);
6537 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6538 return fold (build (TREE_CODE (arg0), type,
6539 fold (build1 (IMAGPART_EXPR, type,
6540 TREE_OPERAND (arg0, 0))),
6541 fold (build1 (IMAGPART_EXPR, type,
6542 TREE_OPERAND (arg0, 1)))));
6545 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
6547 case CLEANUP_POINT_EXPR:
6548 if (! has_cleanups (arg0))
6549 return TREE_OPERAND (t, 0);
6552 enum tree_code code0 = TREE_CODE (arg0);
6553 int kind0 = TREE_CODE_CLASS (code0);
6554 tree arg00 = TREE_OPERAND (arg0, 0);
6557 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
6558 return fold (build1 (code0, type,
6559 fold (build1 (CLEANUP_POINT_EXPR,
6560 TREE_TYPE (arg00), arg00))));
6562 if (kind0 == '<' || kind0 == '2'
6563 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
6564 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
6565 || code0 == TRUTH_XOR_EXPR)
6567 arg01 = TREE_OPERAND (arg0, 1);
6569 if (TREE_CONSTANT (arg00)
6570 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
6571 && ! has_cleanups (arg00)))
6572 return fold (build (code0, type, arg00,
6573 fold (build1 (CLEANUP_POINT_EXPR,
6574 TREE_TYPE (arg01), arg01))));
6576 if (TREE_CONSTANT (arg01))
6577 return fold (build (code0, type,
6578 fold (build1 (CLEANUP_POINT_EXPR,
6579 TREE_TYPE (arg00), arg00)),
6588 } /* switch (code) */
6591 /* Determine if first argument is a multiple of second argument. Return 0 if
6592 it is not, or we cannot easily determined it to be.
6594 An example of the sort of thing we care about (at this point; this routine
6595 could surely be made more general, and expanded to do what the *_DIV_EXPR's
6596 fold cases do now) is discovering that
6598 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
6604 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
6606 This code also handles discovering that
6608 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
6610 is a multiple of 8 so we don't have to worry about dealing with a
6613 Note that we *look* inside a SAVE_EXPR only to determine how it was
6614 calculated; it is not safe for fold to do much of anything else with the
6615 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
6616 at run time. For example, the latter example above *cannot* be implemented
6617 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
6618 evaluation time of the original SAVE_EXPR is not necessarily the same at
6619 the time the new expression is evaluated. The only optimization of this
6620 sort that would be valid is changing
6622 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
6626 SAVE_EXPR (I) * SAVE_EXPR (J)
6628 (where the same SAVE_EXPR (J) is used in the original and the
6629 transformed version). */
6632 multiple_of_p (type, top, bottom)
6637 if (operand_equal_p (top, bottom, 0))
6640 if (TREE_CODE (type) != INTEGER_TYPE)
6643 switch (TREE_CODE (top))
6646 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
6647 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
6651 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
6652 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
6655 /* Can't handle conversions from non-integral or wider integral type. */
6656 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
6657 || (TYPE_PRECISION (type)
6658 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
6661 /* .. fall through ... */
6664 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
6667 if ((TREE_CODE (bottom) != INTEGER_CST)
6668 || (tree_int_cst_sgn (top) < 0)
6669 || (tree_int_cst_sgn (bottom) < 0))
6671 return integer_zerop (const_binop (TRUNC_MOD_EXPR,