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. */
53 static void encode PROTO((HOST_WIDE_INT *,
54 HOST_WIDE_INT, HOST_WIDE_INT));
55 static void decode PROTO((HOST_WIDE_INT *,
56 HOST_WIDE_INT *, HOST_WIDE_INT *));
57 int div_and_round_double PROTO((enum tree_code, int, HOST_WIDE_INT,
58 HOST_WIDE_INT, HOST_WIDE_INT,
59 HOST_WIDE_INT, HOST_WIDE_INT *,
60 HOST_WIDE_INT *, HOST_WIDE_INT *,
62 static int split_tree PROTO((tree, enum tree_code, tree *,
64 static tree int_const_binop PROTO((enum tree_code, tree, tree, int, int));
65 static tree const_binop PROTO((enum tree_code, tree, tree, int));
66 static tree fold_convert PROTO((tree, tree));
67 static enum tree_code invert_tree_comparison PROTO((enum tree_code));
68 static enum tree_code swap_tree_comparison PROTO((enum tree_code));
69 static int truth_value_p PROTO((enum tree_code));
70 static int operand_equal_for_comparison_p PROTO((tree, tree, tree));
71 static int twoval_comparison_p PROTO((tree, tree *, tree *, int *));
72 static tree eval_subst PROTO((tree, tree, tree, tree, tree));
73 static tree omit_one_operand PROTO((tree, tree, tree));
74 static tree pedantic_omit_one_operand PROTO((tree, tree, tree));
75 static tree distribute_bit_expr PROTO((enum tree_code, tree, tree, tree));
76 static tree make_bit_field_ref PROTO((tree, tree, int, int, int));
77 static tree optimize_bit_field_compare PROTO((enum tree_code, tree,
79 static tree decode_field_reference PROTO((tree, int *, int *,
80 enum machine_mode *, int *,
81 int *, tree *, tree *));
82 static int all_ones_mask_p PROTO((tree, int));
83 static int simple_operand_p PROTO((tree));
84 static tree range_binop PROTO((enum tree_code, tree, tree, int,
86 static tree make_range PROTO((tree, int *, tree *, tree *));
87 static tree build_range_check PROTO((tree, tree, int, tree, tree));
88 static int merge_ranges PROTO((int *, tree *, tree *, int, tree, tree,
90 static tree fold_range_test PROTO((tree));
91 static tree unextend PROTO((tree, int, int, tree));
92 static tree fold_truthop PROTO((enum tree_code, tree, tree, tree));
93 static tree strip_compound_expr PROTO((tree, tree));
94 static int multiple_of_p PROTO((tree, tree, tree));
95 static tree constant_boolean_node PROTO((int, tree));
96 static int count_cond PROTO((tree, int));
97 static void const_binop_1 PROTO((PTR));
98 static void fold_convert_1 PROTO((PTR));
101 #define BRANCH_COST 1
104 /* Suppose A1 + B1 = SUM1, using 2's complement arithmetic ignoring overflow.
105 Suppose A, B and SUM have the same respective signs as A1, B1, and SUM1.
106 Then this yields nonzero if overflow occurred during the addition.
107 Overflow occurs if A and B have the same sign, but A and SUM differ in sign.
108 Use `^' to test whether signs differ, and `< 0' to isolate the sign. */
109 #define overflow_sum_sign(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
111 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
112 We do that by representing the two-word integer in 4 words, with only
113 HOST_BITS_PER_WIDE_INT/2 bits stored in each word, as a positive number. */
116 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT/2)) - 1))
117 #define HIGHPART(x) \
118 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT/2)
119 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT/2)
121 /* Unpack a two-word integer into 4 words.
122 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
123 WORDS points to the array of HOST_WIDE_INTs. */
126 encode (words, low, hi)
127 HOST_WIDE_INT *words;
128 HOST_WIDE_INT low, hi;
130 words[0] = LOWPART (low);
131 words[1] = HIGHPART (low);
132 words[2] = LOWPART (hi);
133 words[3] = HIGHPART (hi);
136 /* Pack an array of 4 words into a two-word integer.
137 WORDS points to the array of words.
138 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
141 decode (words, low, hi)
142 HOST_WIDE_INT *words;
143 HOST_WIDE_INT *low, *hi;
145 *low = words[0] | words[1] * BASE;
146 *hi = words[2] | words[3] * BASE;
149 /* Make the integer constant T valid for its type
150 by setting to 0 or 1 all the bits in the constant
151 that don't belong in the type.
152 Yield 1 if a signed overflow occurs, 0 otherwise.
153 If OVERFLOW is nonzero, a signed overflow has already occurred
154 in calculating T, so propagate it.
156 Make the real constant T valid for its type by calling CHECK_FLOAT_VALUE,
160 force_fit_type (t, overflow)
164 HOST_WIDE_INT low, high;
167 if (TREE_CODE (t) == REAL_CST)
169 #ifdef CHECK_FLOAT_VALUE
170 CHECK_FLOAT_VALUE (TYPE_MODE (TREE_TYPE (t)), TREE_REAL_CST (t),
176 else if (TREE_CODE (t) != INTEGER_CST)
179 low = TREE_INT_CST_LOW (t);
180 high = TREE_INT_CST_HIGH (t);
182 if (POINTER_TYPE_P (TREE_TYPE (t)))
185 prec = TYPE_PRECISION (TREE_TYPE (t));
187 /* First clear all bits that are beyond the type's precision. */
189 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
191 else if (prec > HOST_BITS_PER_WIDE_INT)
193 TREE_INT_CST_HIGH (t)
194 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
198 TREE_INT_CST_HIGH (t) = 0;
199 if (prec < HOST_BITS_PER_WIDE_INT)
200 TREE_INT_CST_LOW (t) &= ~((HOST_WIDE_INT) (-1) << prec);
203 /* Unsigned types do not suffer sign extension or overflow. */
204 if (TREE_UNSIGNED (TREE_TYPE (t)))
207 /* If the value's sign bit is set, extend the sign. */
208 if (prec != 2 * HOST_BITS_PER_WIDE_INT
209 && (prec > HOST_BITS_PER_WIDE_INT
210 ? (TREE_INT_CST_HIGH (t)
211 & ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
212 : TREE_INT_CST_LOW (t) & ((HOST_WIDE_INT) 1 << (prec - 1))))
214 /* Value is negative:
215 set to 1 all the bits that are outside this type's precision. */
216 if (prec > HOST_BITS_PER_WIDE_INT)
218 TREE_INT_CST_HIGH (t)
219 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
223 TREE_INT_CST_HIGH (t) = -1;
224 if (prec < HOST_BITS_PER_WIDE_INT)
225 TREE_INT_CST_LOW (t) |= ((HOST_WIDE_INT) (-1) << prec);
229 /* Yield nonzero if signed overflow occurred. */
231 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
235 /* Add two doubleword integers with doubleword result.
236 Each argument is given as two `HOST_WIDE_INT' pieces.
237 One argument is L1 and H1; the other, L2 and H2.
238 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
241 add_double (l1, h1, l2, h2, lv, hv)
242 HOST_WIDE_INT l1, h1, l2, h2;
243 HOST_WIDE_INT *lv, *hv;
248 h = h1 + h2 + ((unsigned HOST_WIDE_INT) l < l1);
252 return overflow_sum_sign (h1, h2, h);
255 /* Negate a doubleword integer with doubleword result.
256 Return nonzero if the operation overflows, assuming it's signed.
257 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
258 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
261 neg_double (l1, h1, lv, hv)
262 HOST_WIDE_INT l1, h1;
263 HOST_WIDE_INT *lv, *hv;
269 return (*hv & h1) < 0;
279 /* Multiply two doubleword integers with doubleword result.
280 Return nonzero if the operation overflows, assuming it's signed.
281 Each argument is given as two `HOST_WIDE_INT' pieces.
282 One argument is L1 and H1; the other, L2 and H2.
283 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
286 mul_double (l1, h1, l2, h2, lv, hv)
287 HOST_WIDE_INT l1, h1, l2, h2;
288 HOST_WIDE_INT *lv, *hv;
290 HOST_WIDE_INT arg1[4];
291 HOST_WIDE_INT arg2[4];
292 HOST_WIDE_INT prod[4 * 2];
293 register unsigned HOST_WIDE_INT carry;
294 register int i, j, k;
295 HOST_WIDE_INT toplow, tophigh, neglow, neghigh;
297 encode (arg1, l1, h1);
298 encode (arg2, l2, h2);
300 bzero ((char *) prod, sizeof prod);
302 for (i = 0; i < 4; i++)
305 for (j = 0; j < 4; j++)
308 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
309 carry += arg1[i] * arg2[j];
310 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
312 prod[k] = LOWPART (carry);
313 carry = HIGHPART (carry);
318 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
320 /* Check for overflow by calculating the top half of the answer in full;
321 it should agree with the low half's sign bit. */
322 decode (prod+4, &toplow, &tophigh);
325 neg_double (l2, h2, &neglow, &neghigh);
326 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
330 neg_double (l1, h1, &neglow, &neghigh);
331 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
333 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
336 /* Shift the doubleword integer in L1, H1 left by COUNT places
337 keeping only PREC bits of result.
338 Shift right if COUNT is negative.
339 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
340 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
343 lshift_double (l1, h1, count, prec, lv, hv, arith)
344 HOST_WIDE_INT l1, h1, count;
346 HOST_WIDE_INT *lv, *hv;
351 rshift_double (l1, h1, - count, prec, lv, hv, arith);
355 #ifdef SHIFT_COUNT_TRUNCATED
356 if (SHIFT_COUNT_TRUNCATED)
360 if (count >= HOST_BITS_PER_WIDE_INT)
362 *hv = (unsigned HOST_WIDE_INT) l1 << (count - HOST_BITS_PER_WIDE_INT);
367 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
368 | ((unsigned HOST_WIDE_INT) l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
369 *lv = (unsigned HOST_WIDE_INT) l1 << count;
373 /* Shift the doubleword integer in L1, H1 right by COUNT places
374 keeping only PREC bits of result. COUNT must be positive.
375 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
376 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
379 rshift_double (l1, h1, count, prec, lv, hv, arith)
380 HOST_WIDE_INT l1, h1, count;
381 int prec ATTRIBUTE_UNUSED;
382 HOST_WIDE_INT *lv, *hv;
385 unsigned HOST_WIDE_INT signmask;
387 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
390 #ifdef SHIFT_COUNT_TRUNCATED
391 if (SHIFT_COUNT_TRUNCATED)
395 if (count >= HOST_BITS_PER_WIDE_INT)
398 *lv = ((signmask << (2 * HOST_BITS_PER_WIDE_INT - count - 1) << 1)
399 | ((unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT)));
403 *lv = (((unsigned HOST_WIDE_INT) l1 >> count)
404 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
405 *hv = ((signmask << (HOST_BITS_PER_WIDE_INT - count))
406 | ((unsigned HOST_WIDE_INT) h1 >> count));
410 /* Rotate the doubleword integer in L1, H1 left by COUNT places
411 keeping only PREC bits of result.
412 Rotate right if COUNT is negative.
413 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
416 lrotate_double (l1, h1, count, prec, lv, hv)
417 HOST_WIDE_INT l1, h1, count;
419 HOST_WIDE_INT *lv, *hv;
421 HOST_WIDE_INT s1l, s1h, s2l, s2h;
427 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
428 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
433 /* Rotate the doubleword integer in L1, H1 left by COUNT places
434 keeping only PREC bits of result. COUNT must be positive.
435 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
438 rrotate_double (l1, h1, count, prec, lv, hv)
439 HOST_WIDE_INT l1, h1, count;
441 HOST_WIDE_INT *lv, *hv;
443 HOST_WIDE_INT s1l, s1h, s2l, s2h;
449 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
450 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
455 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
456 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
457 CODE is a tree code for a kind of division, one of
458 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
460 It controls how the quotient is rounded to a integer.
461 Return nonzero if the operation overflows.
462 UNS nonzero says do unsigned division. */
465 div_and_round_double (code, uns,
466 lnum_orig, hnum_orig, lden_orig, hden_orig,
467 lquo, hquo, lrem, hrem)
470 HOST_WIDE_INT lnum_orig, hnum_orig; /* num == numerator == dividend */
471 HOST_WIDE_INT lden_orig, hden_orig; /* den == denominator == divisor */
472 HOST_WIDE_INT *lquo, *hquo, *lrem, *hrem;
475 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
476 HOST_WIDE_INT den[4], quo[4];
478 unsigned HOST_WIDE_INT work;
479 register unsigned HOST_WIDE_INT carry = 0;
480 HOST_WIDE_INT lnum = lnum_orig;
481 HOST_WIDE_INT hnum = hnum_orig;
482 HOST_WIDE_INT lden = lden_orig;
483 HOST_WIDE_INT hden = hden_orig;
486 if ((hden == 0) && (lden == 0))
487 overflow = 1, lden = 1;
489 /* calculate quotient sign and convert operands to unsigned. */
495 /* (minimum integer) / (-1) is the only overflow case. */
496 if (neg_double (lnum, hnum, &lnum, &hnum) && (lden & hden) == -1)
502 neg_double (lden, hden, &lden, &hden);
506 if (hnum == 0 && hden == 0)
507 { /* single precision */
509 /* This unsigned division rounds toward zero. */
510 *lquo = lnum / (unsigned HOST_WIDE_INT) lden;
515 { /* trivial case: dividend < divisor */
516 /* hden != 0 already checked. */
523 bzero ((char *) quo, sizeof quo);
525 bzero ((char *) num, sizeof num); /* to zero 9th element */
526 bzero ((char *) den, sizeof den);
528 encode (num, lnum, hnum);
529 encode (den, lden, hden);
531 /* Special code for when the divisor < BASE. */
532 if (hden == 0 && lden < (HOST_WIDE_INT) BASE)
534 /* hnum != 0 already checked. */
535 for (i = 4 - 1; i >= 0; i--)
537 work = num[i] + carry * BASE;
538 quo[i] = work / (unsigned HOST_WIDE_INT) lden;
539 carry = work % (unsigned HOST_WIDE_INT) lden;
544 /* Full double precision division,
545 with thanks to Don Knuth's "Seminumerical Algorithms". */
546 int num_hi_sig, den_hi_sig;
547 unsigned HOST_WIDE_INT quo_est, scale;
549 /* Find the highest non-zero divisor digit. */
550 for (i = 4 - 1; ; i--)
556 /* Insure that the first digit of the divisor is at least BASE/2.
557 This is required by the quotient digit estimation algorithm. */
559 scale = BASE / (den[den_hi_sig] + 1);
560 if (scale > 1) { /* scale divisor and dividend */
562 for (i = 0; i <= 4 - 1; i++) {
563 work = (num[i] * scale) + carry;
564 num[i] = LOWPART (work);
565 carry = HIGHPART (work);
568 for (i = 0; i <= 4 - 1; i++) {
569 work = (den[i] * scale) + carry;
570 den[i] = LOWPART (work);
571 carry = HIGHPART (work);
572 if (den[i] != 0) den_hi_sig = i;
579 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--) {
580 /* guess the next quotient digit, quo_est, by dividing the first
581 two remaining dividend digits by the high order quotient digit.
582 quo_est is never low and is at most 2 high. */
583 unsigned HOST_WIDE_INT tmp;
585 num_hi_sig = i + den_hi_sig + 1;
586 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
587 if (num[num_hi_sig] != den[den_hi_sig])
588 quo_est = work / den[den_hi_sig];
592 /* refine quo_est so it's usually correct, and at most one high. */
593 tmp = work - quo_est * den[den_hi_sig];
595 && den[den_hi_sig - 1] * quo_est > (tmp * BASE + num[num_hi_sig - 2]))
598 /* Try QUO_EST as the quotient digit, by multiplying the
599 divisor by QUO_EST and subtracting from the remaining dividend.
600 Keep in mind that QUO_EST is the I - 1st digit. */
603 for (j = 0; j <= den_hi_sig; j++)
605 work = quo_est * den[j] + carry;
606 carry = HIGHPART (work);
607 work = num[i + j] - LOWPART (work);
608 num[i + j] = LOWPART (work);
609 carry += HIGHPART (work) != 0;
612 /* if quo_est was high by one, then num[i] went negative and
613 we need to correct things. */
615 if (num[num_hi_sig] < carry)
618 carry = 0; /* add divisor back in */
619 for (j = 0; j <= den_hi_sig; j++)
621 work = num[i + j] + den[j] + carry;
622 carry = HIGHPART (work);
623 num[i + j] = LOWPART (work);
625 num [num_hi_sig] += carry;
628 /* store the quotient digit. */
633 decode (quo, lquo, hquo);
636 /* if result is negative, make it so. */
638 neg_double (*lquo, *hquo, lquo, hquo);
640 /* compute trial remainder: rem = num - (quo * den) */
641 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
642 neg_double (*lrem, *hrem, lrem, hrem);
643 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
648 case TRUNC_MOD_EXPR: /* round toward zero */
649 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
653 case FLOOR_MOD_EXPR: /* round toward negative infinity */
654 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
657 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
660 else return overflow;
664 case CEIL_MOD_EXPR: /* round toward positive infinity */
665 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
667 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
670 else return overflow;
674 case ROUND_MOD_EXPR: /* round to closest integer */
676 HOST_WIDE_INT labs_rem = *lrem, habs_rem = *hrem;
677 HOST_WIDE_INT labs_den = lden, habs_den = hden, ltwice, htwice;
679 /* get absolute values */
680 if (*hrem < 0) neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
681 if (hden < 0) neg_double (lden, hden, &labs_den, &habs_den);
683 /* if (2 * abs (lrem) >= abs (lden)) */
684 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
685 labs_rem, habs_rem, <wice, &htwice);
686 if (((unsigned HOST_WIDE_INT) habs_den
687 < (unsigned HOST_WIDE_INT) htwice)
688 || (((unsigned HOST_WIDE_INT) habs_den
689 == (unsigned HOST_WIDE_INT) htwice)
690 && ((HOST_WIDE_INT unsigned) labs_den
691 < (unsigned HOST_WIDE_INT) ltwice)))
695 add_double (*lquo, *hquo,
696 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
699 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
702 else return overflow;
710 /* compute true remainder: rem = num - (quo * den) */
711 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
712 neg_double (*lrem, *hrem, lrem, hrem);
713 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
717 #ifndef REAL_ARITHMETIC
718 /* Effectively truncate a real value to represent the nearest possible value
719 in a narrower mode. The result is actually represented in the same data
720 type as the argument, but its value is usually different.
722 A trap may occur during the FP operations and it is the responsibility
723 of the calling function to have a handler established. */
726 real_value_truncate (mode, arg)
727 enum machine_mode mode;
730 return REAL_VALUE_TRUNCATE (mode, arg);
733 #if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
735 /* Check for infinity in an IEEE double precision number. */
741 /* The IEEE 64-bit double format. */
746 unsigned exponent : 11;
747 unsigned mantissa1 : 20;
752 unsigned mantissa1 : 20;
753 unsigned exponent : 11;
759 if (u.big_endian.sign == 1)
762 return (u.big_endian.exponent == 2047
763 && u.big_endian.mantissa1 == 0
764 && u.big_endian.mantissa2 == 0);
769 return (u.little_endian.exponent == 2047
770 && u.little_endian.mantissa1 == 0
771 && u.little_endian.mantissa2 == 0);
775 /* Check whether an IEEE double precision number is a NaN. */
781 /* The IEEE 64-bit double format. */
786 unsigned exponent : 11;
787 unsigned mantissa1 : 20;
792 unsigned mantissa1 : 20;
793 unsigned exponent : 11;
799 if (u.big_endian.sign == 1)
802 return (u.big_endian.exponent == 2047
803 && (u.big_endian.mantissa1 != 0
804 || u.big_endian.mantissa2 != 0));
809 return (u.little_endian.exponent == 2047
810 && (u.little_endian.mantissa1 != 0
811 || u.little_endian.mantissa2 != 0));
815 /* Check for a negative IEEE double precision number. */
821 /* The IEEE 64-bit double format. */
826 unsigned exponent : 11;
827 unsigned mantissa1 : 20;
832 unsigned mantissa1 : 20;
833 unsigned exponent : 11;
839 if (u.big_endian.sign == 1)
842 return u.big_endian.sign;
847 return u.little_endian.sign;
850 #else /* Target not IEEE */
852 /* Let's assume other float formats don't have infinity.
853 (This can be overridden by redefining REAL_VALUE_ISINF.) */
861 /* Let's assume other float formats don't have NaNs.
862 (This can be overridden by redefining REAL_VALUE_ISNAN.) */
870 /* Let's assume other float formats don't have minus zero.
871 (This can be overridden by redefining REAL_VALUE_NEGATIVE.) */
878 #endif /* Target not IEEE */
880 /* Try to change R into its exact multiplicative inverse in machine mode
881 MODE. Return nonzero function value if successful. */
884 exact_real_inverse (mode, r)
885 enum machine_mode mode;
896 /* Usually disable if bounds checks are not reliable. */
897 if ((HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT) && !flag_pretend_float)
900 /* Set array index to the less significant bits in the unions, depending
901 on the endian-ness of the host doubles.
902 Disable if insufficient information on the data structure. */
903 #if HOST_FLOAT_FORMAT == UNKNOWN_FLOAT_FORMAT
906 #if HOST_FLOAT_FORMAT == VAX_FLOAT_FORMAT
909 #if HOST_FLOAT_FORMAT == IBM_FLOAT_FORMAT
912 #define K (2 * HOST_FLOAT_WORDS_BIG_ENDIAN)
917 if (setjmp (float_error))
919 /* Don't do the optimization if there was an arithmetic error. */
921 set_float_handler (NULL_PTR);
924 set_float_handler (float_error);
926 /* Domain check the argument. */
932 if (REAL_VALUE_ISINF (x.d) || REAL_VALUE_ISNAN (x.d))
936 /* Compute the reciprocal and check for numerical exactness.
937 It is unnecessary to check all the significand bits to determine
938 whether X is a power of 2. If X is not, then it is impossible for
939 the bottom half significand of both X and 1/X to be all zero bits.
940 Hence we ignore the data structure of the top half and examine only
941 the low order bits of the two significands. */
943 if (x.i[K] != 0 || x.i[K + 1] != 0 || t.i[K] != 0 || t.i[K + 1] != 0)
946 /* Truncate to the required mode and range-check the result. */
947 y.d = REAL_VALUE_TRUNCATE (mode, t.d);
948 #ifdef CHECK_FLOAT_VALUE
950 if (CHECK_FLOAT_VALUE (mode, y.d, i))
954 /* Fail if truncation changed the value. */
955 if (y.d != t.d || y.d == 0.0)
959 if (REAL_VALUE_ISINF (y.d) || REAL_VALUE_ISNAN (y.d))
963 /* Output the reciprocal and return success flag. */
964 set_float_handler (NULL_PTR);
970 /* Convert C9X hexadecimal floating point string constant S. Return
971 real value type in mode MODE. This function uses the host computer's
972 fp arithmetic when there is no REAL_ARITHMETIC. */
975 real_hex_to_f (s, mode)
977 enum machine_mode mode;
981 unsigned HOST_WIDE_INT low, high;
982 int frexpon, expon, shcount, nrmcount, k;
983 int sign, expsign, decpt, isfloat, isldouble, gotp, lost;
993 while (*p == ' ' || *p == '\t')
996 /* Sign, if any, comes first. */
1004 /* The string is supposed to start with 0x or 0X . */
1008 if (*p == 'x' || *p == 'X')
1021 lost = 0; /* Nonzero low order bits shifted out and discarded. */
1022 frexpon = 0; /* Bits after the decimal point. */
1023 expon = 0; /* Value of exponent. */
1024 decpt = 0; /* How many decimal points. */
1025 gotp = 0; /* How many P's. */
1027 while ((c = *p) != '\0')
1029 if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F')
1030 || (c >= 'a' && c <= 'f'))
1040 if ((high & 0xf0000000) == 0)
1042 high = (high << 4) + ((low >> 28) & 15);
1043 low = (low << 4) + k;
1050 /* Record nonzero lost bits. */
1062 else if (c == 'p' || c == 'P')
1066 /* Sign of exponent. */
1072 /* Value of exponent.
1073 The exponent field is a decimal integer. */
1076 k = (*p++ & 0x7f) - '0';
1077 expon = 10 * expon + k;
1080 /* F suffix is ambiguous in the significand part
1081 so it must appear after the decimal exponent field. */
1082 if (*p == 'f' || *p == 'F')
1089 else if (c == 'l' || c == 'L')
1098 /* Abort if last character read was not legitimate. */
1100 if ((c != '\0' && c != ' ' && c != '\n' && c != '\r') || (decpt > 1))
1102 /* There must be either one decimal point or one p. */
1103 if (decpt == 0 && gotp == 0)
1106 if ((high == 0) && (low == 0))
1119 /* Leave a high guard bit for carry-out. */
1120 if ((high & 0x80000000) != 0)
1123 low = (low >> 1) | (high << 31);
1127 if ((high & 0xffff8000) == 0)
1129 high = (high << 16) + ((low >> 16) & 0xffff);
1133 while ((high & 0xc0000000) == 0)
1135 high = (high << 1) + ((low >> 31) & 1);
1139 if (isfloat || GET_MODE_SIZE(mode) == UNITS_PER_WORD)
1141 /* Keep 24 bits precision, bits 0x7fffff80.
1142 Rounding bit is 0x40. */
1143 lost = lost | low | (high & 0x3f);
1147 if ((high & 0x80) || lost)
1154 /* We need real.c to do long double formats, so here default
1155 to double precision. */
1156 #if HOST_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
1158 Keep 53 bits precision, bits 0x7fffffff fffffc00.
1159 Rounding bit is low word 0x200. */
1160 lost = lost | (low & 0x1ff);
1163 if ((low & 0x400) || lost)
1165 low = (low + 0x200) & 0xfffffc00;
1172 /* Assume it's a VAX with 56-bit significand,
1173 bits 0x7fffffff ffffff80. */
1174 lost = lost | (low & 0x7f);
1177 if ((low & 0x80) || lost)
1179 low = (low + 0x40) & 0xffffff80;
1188 ip = REAL_VALUE_LDEXP (ip, 32) + (double) low;
1189 /* Apply shifts and exponent value as power of 2. */
1190 ip = REAL_VALUE_LDEXP (ip, expon - (nrmcount + frexpon));
1197 #endif /* no REAL_ARITHMETIC */
1199 /* Split a tree IN into a constant and a variable part
1200 that could be combined with CODE to make IN.
1201 CODE must be a commutative arithmetic operation.
1202 Store the constant part into *CONP and the variable in &VARP.
1203 Return 1 if this was done; zero means the tree IN did not decompose
1206 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR.
1207 Therefore, we must tell the caller whether the variable part
1208 was subtracted. We do this by storing 1 or -1 into *VARSIGNP.
1209 The value stored is the coefficient for the variable term.
1210 The constant term we return should always be added;
1211 we negate it if necessary. */
1214 split_tree (in, code, varp, conp, varsignp)
1216 enum tree_code code;
1220 register tree outtype = TREE_TYPE (in);
1224 /* Strip any conversions that don't change the machine mode. */
1225 while ((TREE_CODE (in) == NOP_EXPR
1226 || TREE_CODE (in) == CONVERT_EXPR)
1227 && (TYPE_MODE (TREE_TYPE (in))
1228 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (in, 0)))))
1229 in = TREE_OPERAND (in, 0);
1231 if (TREE_CODE (in) == code
1232 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1233 /* We can associate addition and subtraction together
1234 (even though the C standard doesn't say so)
1235 for integers because the value is not affected.
1236 For reals, the value might be affected, so we can't. */
1237 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1238 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1240 enum tree_code code = TREE_CODE (TREE_OPERAND (in, 0));
1241 if (code == INTEGER_CST)
1243 *conp = TREE_OPERAND (in, 0);
1244 *varp = TREE_OPERAND (in, 1);
1245 if (TYPE_MODE (TREE_TYPE (*varp)) != TYPE_MODE (outtype)
1246 && TREE_TYPE (*varp) != outtype)
1247 *varp = convert (outtype, *varp);
1248 *varsignp = (TREE_CODE (in) == MINUS_EXPR) ? -1 : 1;
1251 if (TREE_CONSTANT (TREE_OPERAND (in, 1)))
1253 *conp = TREE_OPERAND (in, 1);
1254 *varp = TREE_OPERAND (in, 0);
1256 if (TYPE_MODE (TREE_TYPE (*varp)) != TYPE_MODE (outtype)
1257 && TREE_TYPE (*varp) != outtype)
1258 *varp = convert (outtype, *varp);
1259 if (TREE_CODE (in) == MINUS_EXPR)
1261 /* If operation is subtraction and constant is second,
1262 must negate it to get an additive constant.
1263 And this cannot be done unless it is a manifest constant.
1264 It could also be the address of a static variable.
1265 We cannot negate that, so give up. */
1266 if (TREE_CODE (*conp) == INTEGER_CST)
1267 /* Subtracting from integer_zero_node loses for long long. */
1268 *conp = fold (build1 (NEGATE_EXPR, TREE_TYPE (*conp), *conp));
1274 if (TREE_CONSTANT (TREE_OPERAND (in, 0)))
1276 *conp = TREE_OPERAND (in, 0);
1277 *varp = TREE_OPERAND (in, 1);
1278 if (TYPE_MODE (TREE_TYPE (*varp)) != TYPE_MODE (outtype)
1279 && TREE_TYPE (*varp) != outtype)
1280 *varp = convert (outtype, *varp);
1281 *varsignp = (TREE_CODE (in) == MINUS_EXPR) ? -1 : 1;
1288 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1289 to produce a new constant.
1291 If NOTRUNC is nonzero, do not truncate the result to fit the data type.
1292 If FORSIZE is nonzero, compute overflow for unsigned types. */
1295 int_const_binop (code, arg1, arg2, notrunc, forsize)
1296 enum tree_code code;
1297 register tree arg1, arg2;
1298 int notrunc, forsize;
1300 HOST_WIDE_INT int1l, int1h, int2l, int2h;
1301 HOST_WIDE_INT low, hi;
1302 HOST_WIDE_INT garbagel, garbageh;
1304 int uns = TREE_UNSIGNED (TREE_TYPE (arg1));
1306 int no_overflow = 0;
1308 int1l = TREE_INT_CST_LOW (arg1);
1309 int1h = TREE_INT_CST_HIGH (arg1);
1310 int2l = TREE_INT_CST_LOW (arg2);
1311 int2h = TREE_INT_CST_HIGH (arg2);
1316 low = int1l | int2l, hi = int1h | int2h;
1320 low = int1l ^ int2l, hi = int1h ^ int2h;
1324 low = int1l & int2l, hi = int1h & int2h;
1327 case BIT_ANDTC_EXPR:
1328 low = int1l & ~int2l, hi = int1h & ~int2h;
1334 /* It's unclear from the C standard whether shifts can overflow.
1335 The following code ignores overflow; perhaps a C standard
1336 interpretation ruling is needed. */
1337 lshift_double (int1l, int1h, int2l,
1338 TYPE_PRECISION (TREE_TYPE (arg1)),
1347 lrotate_double (int1l, int1h, int2l,
1348 TYPE_PRECISION (TREE_TYPE (arg1)),
1353 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1357 neg_double (int2l, int2h, &low, &hi);
1358 add_double (int1l, int1h, low, hi, &low, &hi);
1359 overflow = overflow_sum_sign (hi, int2h, int1h);
1363 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1366 case TRUNC_DIV_EXPR:
1367 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1368 case EXACT_DIV_EXPR:
1369 /* This is a shortcut for a common special case. */
1370 if (int2h == 0 && int2l > 0
1371 && ! TREE_CONSTANT_OVERFLOW (arg1)
1372 && ! TREE_CONSTANT_OVERFLOW (arg2)
1373 && int1h == 0 && int1l >= 0)
1375 if (code == CEIL_DIV_EXPR)
1377 low = int1l / int2l, hi = 0;
1381 /* ... fall through ... */
1383 case ROUND_DIV_EXPR:
1384 if (int2h == 0 && int2l == 1)
1386 low = int1l, hi = int1h;
1389 if (int1l == int2l && int1h == int2h
1390 && ! (int1l == 0 && int1h == 0))
1395 overflow = div_and_round_double (code, uns,
1396 int1l, int1h, int2l, int2h,
1397 &low, &hi, &garbagel, &garbageh);
1400 case TRUNC_MOD_EXPR:
1401 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1402 /* This is a shortcut for a common special case. */
1403 if (int2h == 0 && int2l > 0
1404 && ! TREE_CONSTANT_OVERFLOW (arg1)
1405 && ! TREE_CONSTANT_OVERFLOW (arg2)
1406 && int1h == 0 && int1l >= 0)
1408 if (code == CEIL_MOD_EXPR)
1410 low = int1l % int2l, hi = 0;
1414 /* ... fall through ... */
1416 case ROUND_MOD_EXPR:
1417 overflow = div_and_round_double (code, uns,
1418 int1l, int1h, int2l, int2h,
1419 &garbagel, &garbageh, &low, &hi);
1426 low = (((unsigned HOST_WIDE_INT) int1h
1427 < (unsigned HOST_WIDE_INT) int2h)
1428 || (((unsigned HOST_WIDE_INT) int1h
1429 == (unsigned HOST_WIDE_INT) int2h)
1430 && ((unsigned HOST_WIDE_INT) int1l
1431 < (unsigned HOST_WIDE_INT) int2l)));
1435 low = ((int1h < int2h)
1436 || ((int1h == int2h)
1437 && ((unsigned HOST_WIDE_INT) int1l
1438 < (unsigned HOST_WIDE_INT) int2l)));
1440 if (low == (code == MIN_EXPR))
1441 low = int1l, hi = int1h;
1443 low = int2l, hi = int2h;
1450 if (TREE_TYPE (arg1) == sizetype && hi == 0
1452 && (TYPE_MAX_VALUE (sizetype) == NULL
1453 || low <= TREE_INT_CST_LOW (TYPE_MAX_VALUE (sizetype)))
1455 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1459 t = build_int_2 (low, hi);
1460 TREE_TYPE (t) = TREE_TYPE (arg1);
1464 = ((notrunc ? (!uns || forsize) && overflow
1465 : force_fit_type (t, (!uns || forsize) && overflow) && ! no_overflow)
1466 | TREE_OVERFLOW (arg1)
1467 | TREE_OVERFLOW (arg2));
1468 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1469 So check if force_fit_type truncated the value. */
1471 && ! TREE_OVERFLOW (t)
1472 && (TREE_INT_CST_HIGH (t) != hi
1473 || TREE_INT_CST_LOW (t) != low))
1474 TREE_OVERFLOW (t) = 1;
1475 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1476 | TREE_CONSTANT_OVERFLOW (arg1)
1477 | TREE_CONSTANT_OVERFLOW (arg2));
1485 REAL_VALUE_TYPE d1, d2;
1486 enum tree_code code;
1492 const_binop_1 (data)
1495 struct cb_args * args = (struct cb_args *) data;
1496 REAL_VALUE_TYPE value;
1498 #ifdef REAL_ARITHMETIC
1499 REAL_ARITHMETIC (value, args->code, args->d1, args->d2);
1504 value = args->d1 + args->d2;
1508 value = args->d1 - args->d2;
1512 value = args->d1 * args->d2;
1516 #ifndef REAL_INFINITY
1521 value = args->d1 / args->d2;
1525 value = MIN (args->d1, args->d2);
1529 value = MAX (args->d1, args->d2);
1535 #endif /* no REAL_ARITHMETIC */
1537 build_real (TREE_TYPE (args->arg1),
1538 real_value_truncate (TYPE_MODE (TREE_TYPE (args->arg1)),
1542 /* Combine two constants ARG1 and ARG2 under operation CODE
1543 to produce a new constant.
1544 We assume ARG1 and ARG2 have the same data type,
1545 or at least are the same kind of constant and the same machine mode.
1547 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1550 const_binop (code, arg1, arg2, notrunc)
1551 enum tree_code code;
1552 register tree arg1, arg2;
1555 STRIP_NOPS (arg1); STRIP_NOPS (arg2);
1557 if (TREE_CODE (arg1) == INTEGER_CST)
1558 return int_const_binop (code, arg1, arg2, notrunc, 0);
1560 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1561 if (TREE_CODE (arg1) == REAL_CST)
1567 struct cb_args args;
1569 d1 = TREE_REAL_CST (arg1);
1570 d2 = TREE_REAL_CST (arg2);
1572 /* If either operand is a NaN, just return it. Otherwise, set up
1573 for floating-point trap; we return an overflow. */
1574 if (REAL_VALUE_ISNAN (d1))
1576 else if (REAL_VALUE_ISNAN (d2))
1579 /* Setup input for const_binop_1() */
1585 if (do_float_handler (const_binop_1, (PTR) &args))
1587 /* Receive output from const_binop_1() */
1592 /* We got an exception from const_binop_1() */
1593 t = copy_node (arg1);
1598 = (force_fit_type (t, overflow)
1599 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1600 TREE_CONSTANT_OVERFLOW (t)
1602 | TREE_CONSTANT_OVERFLOW (arg1)
1603 | TREE_CONSTANT_OVERFLOW (arg2);
1606 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1607 if (TREE_CODE (arg1) == COMPLEX_CST)
1609 register tree type = TREE_TYPE (arg1);
1610 register tree r1 = TREE_REALPART (arg1);
1611 register tree i1 = TREE_IMAGPART (arg1);
1612 register tree r2 = TREE_REALPART (arg2);
1613 register tree i2 = TREE_IMAGPART (arg2);
1619 t = build_complex (type,
1620 const_binop (PLUS_EXPR, r1, r2, notrunc),
1621 const_binop (PLUS_EXPR, i1, i2, notrunc));
1625 t = build_complex (type,
1626 const_binop (MINUS_EXPR, r1, r2, notrunc),
1627 const_binop (MINUS_EXPR, i1, i2, notrunc));
1631 t = build_complex (type,
1632 const_binop (MINUS_EXPR,
1633 const_binop (MULT_EXPR,
1635 const_binop (MULT_EXPR,
1638 const_binop (PLUS_EXPR,
1639 const_binop (MULT_EXPR,
1641 const_binop (MULT_EXPR,
1648 register tree magsquared
1649 = const_binop (PLUS_EXPR,
1650 const_binop (MULT_EXPR, r2, r2, notrunc),
1651 const_binop (MULT_EXPR, i2, i2, notrunc),
1654 t = build_complex (type,
1656 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1657 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1658 const_binop (PLUS_EXPR,
1659 const_binop (MULT_EXPR, r1, r2,
1661 const_binop (MULT_EXPR, i1, i2,
1664 magsquared, notrunc),
1666 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1667 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1668 const_binop (MINUS_EXPR,
1669 const_binop (MULT_EXPR, i1, r2,
1671 const_binop (MULT_EXPR, r1, i2,
1674 magsquared, notrunc));
1686 /* Return an INTEGER_CST with value V . The type is determined by bit_p:
1687 if it is zero, the type is taken from sizetype; if it is one, the type
1688 is taken from bitsizetype. */
1691 size_int_wide (number, high, bit_p)
1692 unsigned HOST_WIDE_INT number, high;
1696 /* Type-size nodes already made for small sizes. */
1697 static tree size_table[2*HOST_BITS_PER_WIDE_INT + 1][2];
1699 if (number < 2*HOST_BITS_PER_WIDE_INT + 1 && ! high
1700 && size_table[number][bit_p] != 0)
1701 return size_table[number][bit_p];
1702 if (number < 2*HOST_BITS_PER_WIDE_INT + 1 && ! high)
1704 push_obstacks_nochange ();
1705 /* Make this a permanent node. */
1706 end_temporary_allocation ();
1707 t = build_int_2 (number, 0);
1708 TREE_TYPE (t) = bit_p ? bitsizetype : sizetype;
1709 size_table[number][bit_p] = t;
1714 t = build_int_2 (number, high);
1715 TREE_TYPE (t) = bit_p ? bitsizetype : sizetype;
1716 TREE_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (t) = force_fit_type (t, 0);
1721 /* Combine operands OP1 and OP2 with arithmetic operation CODE.
1722 CODE is a tree code. Data type is taken from `sizetype',
1723 If the operands are constant, so is the result. */
1726 size_binop (code, arg0, arg1)
1727 enum tree_code code;
1730 /* Handle the special case of two integer constants faster. */
1731 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1733 /* And some specific cases even faster than that. */
1734 if (code == PLUS_EXPR && integer_zerop (arg0))
1736 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1737 && integer_zerop (arg1))
1739 else if (code == MULT_EXPR && integer_onep (arg0))
1742 /* Handle general case of two integer constants. */
1743 return int_const_binop (code, arg0, arg1, 0, 1);
1746 if (arg0 == error_mark_node || arg1 == error_mark_node)
1747 return error_mark_node;
1749 return fold (build (code, sizetype, arg0, arg1));
1752 /* Combine operands OP1 and OP2 with arithmetic operation CODE.
1753 CODE is a tree code. Data type is taken from `ssizetype',
1754 If the operands are constant, so is the result. */
1757 ssize_binop (code, arg0, arg1)
1758 enum tree_code code;
1761 /* Handle the special case of two integer constants faster. */
1762 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1764 /* And some specific cases even faster than that. */
1765 if (code == PLUS_EXPR && integer_zerop (arg0))
1767 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1768 && integer_zerop (arg1))
1770 else if (code == MULT_EXPR && integer_onep (arg0))
1773 /* Handle general case of two integer constants. We convert
1774 arg0 to ssizetype because int_const_binop uses its type for the
1776 arg0 = convert (ssizetype, arg0);
1777 return int_const_binop (code, arg0, arg1, 0, 0);
1780 if (arg0 == error_mark_node || arg1 == error_mark_node)
1781 return error_mark_node;
1783 return fold (build (code, ssizetype, arg0, arg1));
1795 fold_convert_1 (data)
1798 struct fc_args * args = (struct fc_args *) data;
1800 args->t = build_real (args->type,
1801 real_value_truncate (TYPE_MODE (args->type),
1802 TREE_REAL_CST (args->arg1)));
1805 /* Given T, a tree representing type conversion of ARG1, a constant,
1806 return a constant tree representing the result of conversion. */
1809 fold_convert (t, arg1)
1813 register tree type = TREE_TYPE (t);
1816 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1818 if (TREE_CODE (arg1) == INTEGER_CST)
1820 /* If we would build a constant wider than GCC supports,
1821 leave the conversion unfolded. */
1822 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1825 /* Given an integer constant, make new constant with new type,
1826 appropriately sign-extended or truncated. */
1827 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1828 TREE_INT_CST_HIGH (arg1));
1829 TREE_TYPE (t) = type;
1830 /* Indicate an overflow if (1) ARG1 already overflowed,
1831 or (2) force_fit_type indicates an overflow.
1832 Tell force_fit_type that an overflow has already occurred
1833 if ARG1 is a too-large unsigned value and T is signed.
1834 But don't indicate an overflow if converting a pointer. */
1836 = ((force_fit_type (t,
1837 (TREE_INT_CST_HIGH (arg1) < 0
1838 && (TREE_UNSIGNED (type)
1839 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
1840 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1841 || TREE_OVERFLOW (arg1));
1842 TREE_CONSTANT_OVERFLOW (t)
1843 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1845 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1846 else if (TREE_CODE (arg1) == REAL_CST)
1848 /* Don't initialize these, use assignments.
1849 Initialized local aggregates don't work on old compilers. */
1853 tree type1 = TREE_TYPE (arg1);
1856 x = TREE_REAL_CST (arg1);
1857 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
1859 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
1860 if (!no_upper_bound)
1861 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
1863 /* See if X will be in range after truncation towards 0.
1864 To compensate for truncation, move the bounds away from 0,
1865 but reject if X exactly equals the adjusted bounds. */
1866 #ifdef REAL_ARITHMETIC
1867 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
1868 if (!no_upper_bound)
1869 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
1872 if (!no_upper_bound)
1875 /* If X is a NaN, use zero instead and show we have an overflow.
1876 Otherwise, range check. */
1877 if (REAL_VALUE_ISNAN (x))
1878 overflow = 1, x = dconst0;
1879 else if (! (REAL_VALUES_LESS (l, x)
1881 && REAL_VALUES_LESS (x, u)))
1884 #ifndef REAL_ARITHMETIC
1886 HOST_WIDE_INT low, high;
1887 HOST_WIDE_INT half_word
1888 = (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2);
1893 high = (HOST_WIDE_INT) (x / half_word / half_word);
1894 x -= (REAL_VALUE_TYPE) high * half_word * half_word;
1895 if (x >= (REAL_VALUE_TYPE) half_word * half_word / 2)
1897 low = x - (REAL_VALUE_TYPE) half_word * half_word / 2;
1898 low |= (HOST_WIDE_INT) -1 << (HOST_BITS_PER_WIDE_INT - 1);
1901 low = (HOST_WIDE_INT) x;
1902 if (TREE_REAL_CST (arg1) < 0)
1903 neg_double (low, high, &low, &high);
1904 t = build_int_2 (low, high);
1908 HOST_WIDE_INT low, high;
1909 REAL_VALUE_TO_INT (&low, &high, x);
1910 t = build_int_2 (low, high);
1913 TREE_TYPE (t) = type;
1915 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1916 TREE_CONSTANT_OVERFLOW (t)
1917 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1919 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1920 TREE_TYPE (t) = type;
1922 else if (TREE_CODE (type) == REAL_TYPE)
1924 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1925 if (TREE_CODE (arg1) == INTEGER_CST)
1926 return build_real_from_int_cst (type, arg1);
1927 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1928 if (TREE_CODE (arg1) == REAL_CST)
1930 struct fc_args args;
1932 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1935 TREE_TYPE (arg1) = type;
1939 /* Setup input for fold_convert_1() */
1943 if (do_float_handler (fold_convert_1, (PTR) &args))
1945 /* Receive output from fold_convert_1() */
1950 /* We got an exception from fold_convert_1() */
1952 t = copy_node (arg1);
1956 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1957 TREE_CONSTANT_OVERFLOW (t)
1958 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1962 TREE_CONSTANT (t) = 1;
1966 /* Return an expr equal to X but certainly not valid as an lvalue. */
1974 /* These things are certainly not lvalues. */
1975 if (TREE_CODE (x) == NON_LVALUE_EXPR
1976 || TREE_CODE (x) == INTEGER_CST
1977 || TREE_CODE (x) == REAL_CST
1978 || TREE_CODE (x) == STRING_CST
1979 || TREE_CODE (x) == ADDR_EXPR)
1982 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
1983 TREE_CONSTANT (result) = TREE_CONSTANT (x);
1987 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1988 Zero means allow extended lvalues. */
1990 int pedantic_lvalues;
1992 /* When pedantic, return an expr equal to X but certainly not valid as a
1993 pedantic lvalue. Otherwise, return X. */
1996 pedantic_non_lvalue (x)
1999 if (pedantic_lvalues)
2000 return non_lvalue (x);
2005 /* Given a tree comparison code, return the code that is the logical inverse
2006 of the given code. It is not safe to do this for floating-point
2007 comparisons, except for NE_EXPR and EQ_EXPR. */
2009 static enum tree_code
2010 invert_tree_comparison (code)
2011 enum tree_code code;
2032 /* Similar, but return the comparison that results if the operands are
2033 swapped. This is safe for floating-point. */
2035 static enum tree_code
2036 swap_tree_comparison (code)
2037 enum tree_code code;
2057 /* Return nonzero if CODE is a tree code that represents a truth value. */
2060 truth_value_p (code)
2061 enum tree_code code;
2063 return (TREE_CODE_CLASS (code) == '<'
2064 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2065 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2066 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2069 /* Return nonzero if two operands are necessarily equal.
2070 If ONLY_CONST is non-zero, only return non-zero for constants.
2071 This function tests whether the operands are indistinguishable;
2072 it does not test whether they are equal using C's == operation.
2073 The distinction is important for IEEE floating point, because
2074 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2075 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
2078 operand_equal_p (arg0, arg1, only_const)
2082 /* If both types don't have the same signedness, then we can't consider
2083 them equal. We must check this before the STRIP_NOPS calls
2084 because they may change the signedness of the arguments. */
2085 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
2091 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2092 /* This is needed for conversions and for COMPONENT_REF.
2093 Might as well play it safe and always test this. */
2094 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2097 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2098 We don't care about side effects in that case because the SAVE_EXPR
2099 takes care of that for us. In all other cases, two expressions are
2100 equal if they have no side effects. If we have two identical
2101 expressions with side effects that should be treated the same due
2102 to the only side effects being identical SAVE_EXPR's, that will
2103 be detected in the recursive calls below. */
2104 if (arg0 == arg1 && ! only_const
2105 && (TREE_CODE (arg0) == SAVE_EXPR
2106 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2109 /* Next handle constant cases, those for which we can return 1 even
2110 if ONLY_CONST is set. */
2111 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2112 switch (TREE_CODE (arg0))
2115 return (! TREE_CONSTANT_OVERFLOW (arg0)
2116 && ! TREE_CONSTANT_OVERFLOW (arg1)
2117 && TREE_INT_CST_LOW (arg0) == TREE_INT_CST_LOW (arg1)
2118 && TREE_INT_CST_HIGH (arg0) == TREE_INT_CST_HIGH (arg1));
2121 return (! TREE_CONSTANT_OVERFLOW (arg0)
2122 && ! TREE_CONSTANT_OVERFLOW (arg1)
2123 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2124 TREE_REAL_CST (arg1)));
2127 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2129 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2133 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2134 && ! strncmp (TREE_STRING_POINTER (arg0),
2135 TREE_STRING_POINTER (arg1),
2136 TREE_STRING_LENGTH (arg0)));
2139 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2148 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2151 /* Two conversions are equal only if signedness and modes match. */
2152 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2153 && (TREE_UNSIGNED (TREE_TYPE (arg0))
2154 != TREE_UNSIGNED (TREE_TYPE (arg1))))
2157 return operand_equal_p (TREE_OPERAND (arg0, 0),
2158 TREE_OPERAND (arg1, 0), 0);
2162 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
2163 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
2167 /* For commutative ops, allow the other order. */
2168 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
2169 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
2170 || TREE_CODE (arg0) == BIT_IOR_EXPR
2171 || TREE_CODE (arg0) == BIT_XOR_EXPR
2172 || TREE_CODE (arg0) == BIT_AND_EXPR
2173 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
2174 && operand_equal_p (TREE_OPERAND (arg0, 0),
2175 TREE_OPERAND (arg1, 1), 0)
2176 && operand_equal_p (TREE_OPERAND (arg0, 1),
2177 TREE_OPERAND (arg1, 0), 0));
2180 switch (TREE_CODE (arg0))
2183 return operand_equal_p (TREE_OPERAND (arg0, 0),
2184 TREE_OPERAND (arg1, 0), 0);
2188 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2189 TREE_OPERAND (arg1, 0), 0)
2190 && operand_equal_p (TREE_OPERAND (arg0, 1),
2191 TREE_OPERAND (arg1, 1), 0));
2194 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2195 TREE_OPERAND (arg1, 0), 0)
2196 && operand_equal_p (TREE_OPERAND (arg0, 1),
2197 TREE_OPERAND (arg1, 1), 0)
2198 && operand_equal_p (TREE_OPERAND (arg0, 2),
2199 TREE_OPERAND (arg1, 2), 0));
2205 if (TREE_CODE (arg0) == RTL_EXPR)
2206 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2214 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2215 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2217 When in doubt, return 0. */
2220 operand_equal_for_comparison_p (arg0, arg1, other)
2224 int unsignedp1, unsignedpo;
2225 tree primarg0, primarg1, primother;
2226 unsigned correct_width;
2228 if (operand_equal_p (arg0, arg1, 0))
2231 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2232 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2235 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2236 and see if the inner values are the same. This removes any
2237 signedness comparison, which doesn't matter here. */
2238 primarg0 = arg0, primarg1 = arg1;
2239 STRIP_NOPS (primarg0); STRIP_NOPS (primarg1);
2240 if (operand_equal_p (primarg0, primarg1, 0))
2243 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2244 actual comparison operand, ARG0.
2246 First throw away any conversions to wider types
2247 already present in the operands. */
2249 primarg1 = get_narrower (arg1, &unsignedp1);
2250 primother = get_narrower (other, &unsignedpo);
2252 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2253 if (unsignedp1 == unsignedpo
2254 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2255 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2257 tree type = TREE_TYPE (arg0);
2259 /* Make sure shorter operand is extended the right way
2260 to match the longer operand. */
2261 primarg1 = convert (signed_or_unsigned_type (unsignedp1,
2262 TREE_TYPE (primarg1)),
2265 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2272 /* See if ARG is an expression that is either a comparison or is performing
2273 arithmetic on comparisons. The comparisons must only be comparing
2274 two different values, which will be stored in *CVAL1 and *CVAL2; if
2275 they are non-zero it means that some operands have already been found.
2276 No variables may be used anywhere else in the expression except in the
2277 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2278 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2280 If this is true, return 1. Otherwise, return zero. */
2283 twoval_comparison_p (arg, cval1, cval2, save_p)
2285 tree *cval1, *cval2;
2288 enum tree_code code = TREE_CODE (arg);
2289 char class = TREE_CODE_CLASS (code);
2291 /* We can handle some of the 'e' cases here. */
2292 if (class == 'e' && code == TRUTH_NOT_EXPR)
2294 else if (class == 'e'
2295 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2296 || code == COMPOUND_EXPR))
2299 /* ??? Disable this since the SAVE_EXPR might already be in use outside
2300 the expression. There may be no way to make this work, but it needs
2301 to be looked at again for 2.6. */
2303 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0)
2305 /* If we've already found a CVAL1 or CVAL2, this expression is
2306 two complex to handle. */
2307 if (*cval1 || *cval2)
2318 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2321 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2322 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2323 cval1, cval2, save_p));
2329 if (code == COND_EXPR)
2330 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2331 cval1, cval2, save_p)
2332 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2333 cval1, cval2, save_p)
2334 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2335 cval1, cval2, save_p));
2339 /* First see if we can handle the first operand, then the second. For
2340 the second operand, we know *CVAL1 can't be zero. It must be that
2341 one side of the comparison is each of the values; test for the
2342 case where this isn't true by failing if the two operands
2345 if (operand_equal_p (TREE_OPERAND (arg, 0),
2346 TREE_OPERAND (arg, 1), 0))
2350 *cval1 = TREE_OPERAND (arg, 0);
2351 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2353 else if (*cval2 == 0)
2354 *cval2 = TREE_OPERAND (arg, 0);
2355 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2360 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2362 else if (*cval2 == 0)
2363 *cval2 = TREE_OPERAND (arg, 1);
2364 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2376 /* ARG is a tree that is known to contain just arithmetic operations and
2377 comparisons. Evaluate the operations in the tree substituting NEW0 for
2378 any occurrence of OLD0 as an operand of a comparison and likewise for
2382 eval_subst (arg, old0, new0, old1, new1)
2384 tree old0, new0, old1, new1;
2386 tree type = TREE_TYPE (arg);
2387 enum tree_code code = TREE_CODE (arg);
2388 char class = TREE_CODE_CLASS (code);
2390 /* We can handle some of the 'e' cases here. */
2391 if (class == 'e' && code == TRUTH_NOT_EXPR)
2393 else if (class == 'e'
2394 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2400 return fold (build1 (code, type,
2401 eval_subst (TREE_OPERAND (arg, 0),
2402 old0, new0, old1, new1)));
2405 return fold (build (code, type,
2406 eval_subst (TREE_OPERAND (arg, 0),
2407 old0, new0, old1, new1),
2408 eval_subst (TREE_OPERAND (arg, 1),
2409 old0, new0, old1, new1)));
2415 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2418 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2421 return fold (build (code, type,
2422 eval_subst (TREE_OPERAND (arg, 0),
2423 old0, new0, old1, new1),
2424 eval_subst (TREE_OPERAND (arg, 1),
2425 old0, new0, old1, new1),
2426 eval_subst (TREE_OPERAND (arg, 2),
2427 old0, new0, old1, new1)));
2431 /* fall through - ??? */
2435 tree arg0 = TREE_OPERAND (arg, 0);
2436 tree arg1 = TREE_OPERAND (arg, 1);
2438 /* We need to check both for exact equality and tree equality. The
2439 former will be true if the operand has a side-effect. In that
2440 case, we know the operand occurred exactly once. */
2442 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2444 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2447 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2449 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2452 return fold (build (code, type, arg0, arg1));
2460 /* Return a tree for the case when the result of an expression is RESULT
2461 converted to TYPE and OMITTED was previously an operand of the expression
2462 but is now not needed (e.g., we folded OMITTED * 0).
2464 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2465 the conversion of RESULT to TYPE. */
2468 omit_one_operand (type, result, omitted)
2469 tree type, result, omitted;
2471 tree t = convert (type, result);
2473 if (TREE_SIDE_EFFECTS (omitted))
2474 return build (COMPOUND_EXPR, type, omitted, t);
2476 return non_lvalue (t);
2479 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2482 pedantic_omit_one_operand (type, result, omitted)
2483 tree type, result, omitted;
2485 tree t = convert (type, result);
2487 if (TREE_SIDE_EFFECTS (omitted))
2488 return build (COMPOUND_EXPR, type, omitted, t);
2490 return pedantic_non_lvalue (t);
2495 /* Return a simplified tree node for the truth-negation of ARG. This
2496 never alters ARG itself. We assume that ARG is an operation that
2497 returns a truth value (0 or 1). */
2500 invert_truthvalue (arg)
2503 tree type = TREE_TYPE (arg);
2504 enum tree_code code = TREE_CODE (arg);
2506 if (code == ERROR_MARK)
2509 /* If this is a comparison, we can simply invert it, except for
2510 floating-point non-equality comparisons, in which case we just
2511 enclose a TRUTH_NOT_EXPR around what we have. */
2513 if (TREE_CODE_CLASS (code) == '<')
2515 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2516 && !flag_fast_math && code != NE_EXPR && code != EQ_EXPR)
2517 return build1 (TRUTH_NOT_EXPR, type, arg);
2519 return build (invert_tree_comparison (code), type,
2520 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2526 return convert (type, build_int_2 (TREE_INT_CST_LOW (arg) == 0
2527 && TREE_INT_CST_HIGH (arg) == 0, 0));
2529 case TRUTH_AND_EXPR:
2530 return build (TRUTH_OR_EXPR, type,
2531 invert_truthvalue (TREE_OPERAND (arg, 0)),
2532 invert_truthvalue (TREE_OPERAND (arg, 1)));
2535 return build (TRUTH_AND_EXPR, type,
2536 invert_truthvalue (TREE_OPERAND (arg, 0)),
2537 invert_truthvalue (TREE_OPERAND (arg, 1)));
2539 case TRUTH_XOR_EXPR:
2540 /* Here we can invert either operand. We invert the first operand
2541 unless the second operand is a TRUTH_NOT_EXPR in which case our
2542 result is the XOR of the first operand with the inside of the
2543 negation of the second operand. */
2545 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2546 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2547 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2549 return build (TRUTH_XOR_EXPR, type,
2550 invert_truthvalue (TREE_OPERAND (arg, 0)),
2551 TREE_OPERAND (arg, 1));
2553 case TRUTH_ANDIF_EXPR:
2554 return build (TRUTH_ORIF_EXPR, type,
2555 invert_truthvalue (TREE_OPERAND (arg, 0)),
2556 invert_truthvalue (TREE_OPERAND (arg, 1)));
2558 case TRUTH_ORIF_EXPR:
2559 return build (TRUTH_ANDIF_EXPR, type,
2560 invert_truthvalue (TREE_OPERAND (arg, 0)),
2561 invert_truthvalue (TREE_OPERAND (arg, 1)));
2563 case TRUTH_NOT_EXPR:
2564 return TREE_OPERAND (arg, 0);
2567 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2568 invert_truthvalue (TREE_OPERAND (arg, 1)),
2569 invert_truthvalue (TREE_OPERAND (arg, 2)));
2572 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2573 invert_truthvalue (TREE_OPERAND (arg, 1)));
2575 case NON_LVALUE_EXPR:
2576 return invert_truthvalue (TREE_OPERAND (arg, 0));
2581 return build1 (TREE_CODE (arg), type,
2582 invert_truthvalue (TREE_OPERAND (arg, 0)));
2585 if (!integer_onep (TREE_OPERAND (arg, 1)))
2587 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2590 return build1 (TRUTH_NOT_EXPR, type, arg);
2592 case CLEANUP_POINT_EXPR:
2593 return build1 (CLEANUP_POINT_EXPR, type,
2594 invert_truthvalue (TREE_OPERAND (arg, 0)));
2599 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2601 return build1 (TRUTH_NOT_EXPR, type, arg);
2604 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2605 operands are another bit-wise operation with a common input. If so,
2606 distribute the bit operations to save an operation and possibly two if
2607 constants are involved. For example, convert
2608 (A | B) & (A | C) into A | (B & C)
2609 Further simplification will occur if B and C are constants.
2611 If this optimization cannot be done, 0 will be returned. */
2614 distribute_bit_expr (code, type, arg0, arg1)
2615 enum tree_code code;
2622 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2623 || TREE_CODE (arg0) == code
2624 || (TREE_CODE (arg0) != BIT_AND_EXPR
2625 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2628 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2630 common = TREE_OPERAND (arg0, 0);
2631 left = TREE_OPERAND (arg0, 1);
2632 right = TREE_OPERAND (arg1, 1);
2634 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2636 common = TREE_OPERAND (arg0, 0);
2637 left = TREE_OPERAND (arg0, 1);
2638 right = TREE_OPERAND (arg1, 0);
2640 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2642 common = TREE_OPERAND (arg0, 1);
2643 left = TREE_OPERAND (arg0, 0);
2644 right = TREE_OPERAND (arg1, 1);
2646 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2648 common = TREE_OPERAND (arg0, 1);
2649 left = TREE_OPERAND (arg0, 0);
2650 right = TREE_OPERAND (arg1, 0);
2655 return fold (build (TREE_CODE (arg0), type, common,
2656 fold (build (code, type, left, right))));
2659 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2660 starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */
2663 make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp)
2666 int bitsize, bitpos;
2669 tree result = build (BIT_FIELD_REF, type, inner,
2670 size_int (bitsize), bitsize_int (bitpos, 0L));
2672 TREE_UNSIGNED (result) = unsignedp;
2677 /* Optimize a bit-field compare.
2679 There are two cases: First is a compare against a constant and the
2680 second is a comparison of two items where the fields are at the same
2681 bit position relative to the start of a chunk (byte, halfword, word)
2682 large enough to contain it. In these cases we can avoid the shift
2683 implicit in bitfield extractions.
2685 For constants, we emit a compare of the shifted constant with the
2686 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2687 compared. For two fields at the same position, we do the ANDs with the
2688 similar mask and compare the result of the ANDs.
2690 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2691 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2692 are the left and right operands of the comparison, respectively.
2694 If the optimization described above can be done, we return the resulting
2695 tree. Otherwise we return zero. */
2698 optimize_bit_field_compare (code, compare_type, lhs, rhs)
2699 enum tree_code code;
2703 int lbitpos, lbitsize, rbitpos, rbitsize;
2704 int lnbitpos, lnbitsize, rnbitpos = 0, rnbitsize = 0;
2705 tree type = TREE_TYPE (lhs);
2706 tree signed_type, unsigned_type;
2707 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2708 enum machine_mode lmode, rmode, lnmode, rnmode = VOIDmode;
2709 int lunsignedp, runsignedp;
2710 int lvolatilep = 0, rvolatilep = 0;
2712 tree linner, rinner = NULL_TREE;
2716 /* Get all the information about the extractions being done. If the bit size
2717 if the same as the size of the underlying object, we aren't doing an
2718 extraction at all and so can do nothing. */
2719 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2720 &lunsignedp, &lvolatilep, &alignment);
2721 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2727 /* If this is not a constant, we can only do something if bit positions,
2728 sizes, and signedness are the same. */
2729 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2730 &runsignedp, &rvolatilep, &alignment);
2732 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2733 || lunsignedp != runsignedp || offset != 0)
2737 /* See if we can find a mode to refer to this field. We should be able to,
2738 but fail if we can't. */
2739 lnmode = get_best_mode (lbitsize, lbitpos,
2740 TYPE_ALIGN (TREE_TYPE (linner)), word_mode,
2742 if (lnmode == VOIDmode)
2745 /* Set signed and unsigned types of the precision of this mode for the
2747 signed_type = type_for_mode (lnmode, 0);
2748 unsigned_type = type_for_mode (lnmode, 1);
2752 rnmode = get_best_mode (rbitsize, rbitpos,
2753 TYPE_ALIGN (TREE_TYPE (rinner)), word_mode,
2755 if (rnmode == VOIDmode)
2759 /* Compute the bit position and size for the new reference and our offset
2760 within it. If the new reference is the same size as the original, we
2761 won't optimize anything, so return zero. */
2762 lnbitsize = GET_MODE_BITSIZE (lnmode);
2763 lnbitpos = lbitpos & ~ (lnbitsize - 1);
2764 lbitpos -= lnbitpos;
2765 if (lnbitsize == lbitsize)
2770 rnbitsize = GET_MODE_BITSIZE (rnmode);
2771 rnbitpos = rbitpos & ~ (rnbitsize - 1);
2772 rbitpos -= rnbitpos;
2773 if (rnbitsize == rbitsize)
2777 if (BYTES_BIG_ENDIAN)
2778 lbitpos = lnbitsize - lbitsize - lbitpos;
2780 /* Make the mask to be used against the extracted field. */
2781 mask = build_int_2 (~0, ~0);
2782 TREE_TYPE (mask) = unsigned_type;
2783 force_fit_type (mask, 0);
2784 mask = convert (unsigned_type, mask);
2785 mask = const_binop (LSHIFT_EXPR, mask, size_int (lnbitsize - lbitsize), 0);
2786 mask = const_binop (RSHIFT_EXPR, mask,
2787 size_int (lnbitsize - lbitsize - lbitpos), 0);
2790 /* If not comparing with constant, just rework the comparison
2792 return build (code, compare_type,
2793 build (BIT_AND_EXPR, unsigned_type,
2794 make_bit_field_ref (linner, unsigned_type,
2795 lnbitsize, lnbitpos, 1),
2797 build (BIT_AND_EXPR, unsigned_type,
2798 make_bit_field_ref (rinner, unsigned_type,
2799 rnbitsize, rnbitpos, 1),
2802 /* Otherwise, we are handling the constant case. See if the constant is too
2803 big for the field. Warn and return a tree of for 0 (false) if so. We do
2804 this not only for its own sake, but to avoid having to test for this
2805 error case below. If we didn't, we might generate wrong code.
2807 For unsigned fields, the constant shifted right by the field length should
2808 be all zero. For signed fields, the high-order bits should agree with
2813 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2814 convert (unsigned_type, rhs),
2815 size_int (lbitsize), 0)))
2817 warning ("comparison is always %d due to width of bitfield",
2819 return convert (compare_type,
2821 ? integer_one_node : integer_zero_node));
2826 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
2827 size_int (lbitsize - 1), 0);
2828 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2830 warning ("comparison is always %d due to width of bitfield",
2832 return convert (compare_type,
2834 ? integer_one_node : integer_zero_node));
2838 /* Single-bit compares should always be against zero. */
2839 if (lbitsize == 1 && ! integer_zerop (rhs))
2841 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2842 rhs = convert (type, integer_zero_node);
2845 /* Make a new bitfield reference, shift the constant over the
2846 appropriate number of bits and mask it with the computed mask
2847 (in case this was a signed field). If we changed it, make a new one. */
2848 lhs = make_bit_field_ref (linner, unsigned_type, lnbitsize, lnbitpos, 1);
2851 TREE_SIDE_EFFECTS (lhs) = 1;
2852 TREE_THIS_VOLATILE (lhs) = 1;
2855 rhs = fold (const_binop (BIT_AND_EXPR,
2856 const_binop (LSHIFT_EXPR,
2857 convert (unsigned_type, rhs),
2858 size_int (lbitpos), 0),
2861 return build (code, compare_type,
2862 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2866 /* Subroutine for fold_truthop: decode a field reference.
2868 If EXP is a comparison reference, we return the innermost reference.
2870 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2871 set to the starting bit number.
2873 If the innermost field can be completely contained in a mode-sized
2874 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2876 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2877 otherwise it is not changed.
2879 *PUNSIGNEDP is set to the signedness of the field.
2881 *PMASK is set to the mask used. This is either contained in a
2882 BIT_AND_EXPR or derived from the width of the field.
2884 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2886 Return 0 if this is not a component reference or is one that we can't
2887 do anything with. */
2890 decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp,
2891 pvolatilep, pmask, pand_mask)
2893 int *pbitsize, *pbitpos;
2894 enum machine_mode *pmode;
2895 int *punsignedp, *pvolatilep;
2900 tree mask, inner, offset;
2905 /* All the optimizations using this function assume integer fields.
2906 There are problems with FP fields since the type_for_size call
2907 below can fail for, e.g., XFmode. */
2908 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
2913 if (TREE_CODE (exp) == BIT_AND_EXPR)
2915 and_mask = TREE_OPERAND (exp, 1);
2916 exp = TREE_OPERAND (exp, 0);
2917 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
2918 if (TREE_CODE (and_mask) != INTEGER_CST)
2923 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
2924 punsignedp, pvolatilep, &alignment);
2925 if ((inner == exp && and_mask == 0)
2926 || *pbitsize < 0 || offset != 0)
2929 /* Compute the mask to access the bitfield. */
2930 unsigned_type = type_for_size (*pbitsize, 1);
2931 precision = TYPE_PRECISION (unsigned_type);
2933 mask = build_int_2 (~0, ~0);
2934 TREE_TYPE (mask) = unsigned_type;
2935 force_fit_type (mask, 0);
2936 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2937 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2939 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
2941 mask = fold (build (BIT_AND_EXPR, unsigned_type,
2942 convert (unsigned_type, and_mask), mask));
2945 *pand_mask = and_mask;
2949 /* Return non-zero if MASK represents a mask of SIZE ones in the low-order
2953 all_ones_mask_p (mask, size)
2957 tree type = TREE_TYPE (mask);
2958 int precision = TYPE_PRECISION (type);
2961 tmask = build_int_2 (~0, ~0);
2962 TREE_TYPE (tmask) = signed_type (type);
2963 force_fit_type (tmask, 0);
2965 tree_int_cst_equal (mask,
2966 const_binop (RSHIFT_EXPR,
2967 const_binop (LSHIFT_EXPR, tmask,
2968 size_int (precision - size),
2970 size_int (precision - size), 0));
2973 /* Subroutine for fold_truthop: determine if an operand is simple enough
2974 to be evaluated unconditionally. */
2977 simple_operand_p (exp)
2980 /* Strip any conversions that don't change the machine mode. */
2981 while ((TREE_CODE (exp) == NOP_EXPR
2982 || TREE_CODE (exp) == CONVERT_EXPR)
2983 && (TYPE_MODE (TREE_TYPE (exp))
2984 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
2985 exp = TREE_OPERAND (exp, 0);
2987 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
2988 || (TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
2989 && ! TREE_ADDRESSABLE (exp)
2990 && ! TREE_THIS_VOLATILE (exp)
2991 && ! DECL_NONLOCAL (exp)
2992 /* Don't regard global variables as simple. They may be
2993 allocated in ways unknown to the compiler (shared memory,
2994 #pragma weak, etc). */
2995 && ! TREE_PUBLIC (exp)
2996 && ! DECL_EXTERNAL (exp)
2997 /* Loading a static variable is unduly expensive, but global
2998 registers aren't expensive. */
2999 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3002 /* The following functions are subroutines to fold_range_test and allow it to
3003 try to change a logical combination of comparisons into a range test.
3006 X == 2 && X == 3 && X == 4 && X == 5
3010 (unsigned) (X - 2) <= 3
3012 We describe each set of comparisons as being either inside or outside
3013 a range, using a variable named like IN_P, and then describe the
3014 range with a lower and upper bound. If one of the bounds is omitted,
3015 it represents either the highest or lowest value of the type.
3017 In the comments below, we represent a range by two numbers in brackets
3018 preceded by a "+" to designate being inside that range, or a "-" to
3019 designate being outside that range, so the condition can be inverted by
3020 flipping the prefix. An omitted bound is represented by a "-". For
3021 example, "- [-, 10]" means being outside the range starting at the lowest
3022 possible value and ending at 10, in other words, being greater than 10.
3023 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3026 We set up things so that the missing bounds are handled in a consistent
3027 manner so neither a missing bound nor "true" and "false" need to be
3028 handled using a special case. */
3030 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3031 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3032 and UPPER1_P are nonzero if the respective argument is an upper bound
3033 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3034 must be specified for a comparison. ARG1 will be converted to ARG0's
3035 type if both are specified. */
3038 range_binop (code, type, arg0, upper0_p, arg1, upper1_p)
3039 enum tree_code code;
3042 int upper0_p, upper1_p;
3048 /* If neither arg represents infinity, do the normal operation.
3049 Else, if not a comparison, return infinity. Else handle the special
3050 comparison rules. Note that most of the cases below won't occur, but
3051 are handled for consistency. */
3053 if (arg0 != 0 && arg1 != 0)
3055 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
3056 arg0, convert (TREE_TYPE (arg0), arg1)));
3058 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3061 if (TREE_CODE_CLASS (code) != '<')
3064 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3065 for neither. In real maths, we cannot assume open ended ranges are
3066 the same. But, this is computer arithmetic, where numbers are finite.
3067 We can therefore make the transformation of any unbounded range with
3068 the value Z, Z being greater than any representable number. This permits
3069 us to treat unbounded ranges as equal. */
3070 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3071 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3075 result = sgn0 == sgn1;
3078 result = sgn0 != sgn1;
3081 result = sgn0 < sgn1;
3084 result = sgn0 <= sgn1;
3087 result = sgn0 > sgn1;
3090 result = sgn0 >= sgn1;
3096 return convert (type, result ? integer_one_node : integer_zero_node);
3099 /* Given EXP, a logical expression, set the range it is testing into
3100 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3101 actually being tested. *PLOW and *PHIGH will have be made the same type
3102 as the returned expression. If EXP is not a comparison, we will most
3103 likely not be returning a useful value and range. */
3106 make_range (exp, pin_p, plow, phigh)
3111 enum tree_code code;
3112 tree arg0, arg1, type = NULL_TREE;
3113 tree orig_type = NULL_TREE;
3115 tree low, high, n_low, n_high;
3117 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3118 and see if we can refine the range. Some of the cases below may not
3119 happen, but it doesn't seem worth worrying about this. We "continue"
3120 the outer loop when we've changed something; otherwise we "break"
3121 the switch, which will "break" the while. */
3123 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
3127 code = TREE_CODE (exp);
3129 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3131 arg0 = TREE_OPERAND (exp, 0);
3132 if (TREE_CODE_CLASS (code) == '<'
3133 || TREE_CODE_CLASS (code) == '1'
3134 || TREE_CODE_CLASS (code) == '2')
3135 type = TREE_TYPE (arg0);
3136 if (TREE_CODE_CLASS (code) == '2'
3137 || TREE_CODE_CLASS (code) == '<'
3138 || (TREE_CODE_CLASS (code) == 'e'
3139 && tree_code_length[(int) code] > 1))
3140 arg1 = TREE_OPERAND (exp, 1);
3143 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3144 lose a cast by accident. */
3145 if (type != NULL_TREE && orig_type == NULL_TREE)
3150 case TRUTH_NOT_EXPR:
3151 in_p = ! in_p, exp = arg0;
3154 case EQ_EXPR: case NE_EXPR:
3155 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3156 /* We can only do something if the range is testing for zero
3157 and if the second operand is an integer constant. Note that
3158 saying something is "in" the range we make is done by
3159 complementing IN_P since it will set in the initial case of
3160 being not equal to zero; "out" is leaving it alone. */
3161 if (low == 0 || high == 0
3162 || ! integer_zerop (low) || ! integer_zerop (high)
3163 || TREE_CODE (arg1) != INTEGER_CST)
3168 case NE_EXPR: /* - [c, c] */
3171 case EQ_EXPR: /* + [c, c] */
3172 in_p = ! in_p, low = high = arg1;
3174 case GT_EXPR: /* - [-, c] */
3175 low = 0, high = arg1;
3177 case GE_EXPR: /* + [c, -] */
3178 in_p = ! in_p, low = arg1, high = 0;
3180 case LT_EXPR: /* - [c, -] */
3181 low = arg1, high = 0;
3183 case LE_EXPR: /* + [-, c] */
3184 in_p = ! in_p, low = 0, high = arg1;
3192 /* If this is an unsigned comparison, we also know that EXP is
3193 greater than or equal to zero. We base the range tests we make
3194 on that fact, so we record it here so we can parse existing
3196 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3198 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3199 1, convert (type, integer_zero_node),
3203 in_p = n_in_p, low = n_low, high = n_high;
3205 /* If the high bound is missing, reverse the range so it
3206 goes from zero to the low bound minus 1. */
3210 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3211 integer_one_node, 0);
3212 low = convert (type, integer_zero_node);
3218 /* (-x) IN [a,b] -> x in [-b, -a] */
3219 n_low = range_binop (MINUS_EXPR, type,
3220 convert (type, integer_zero_node), 0, high, 1);
3221 n_high = range_binop (MINUS_EXPR, type,
3222 convert (type, integer_zero_node), 0, low, 0);
3223 low = n_low, high = n_high;
3229 exp = build (MINUS_EXPR, type, build1 (NEGATE_EXPR, type, arg0),
3230 convert (type, integer_one_node));
3233 case PLUS_EXPR: case MINUS_EXPR:
3234 if (TREE_CODE (arg1) != INTEGER_CST)
3237 /* If EXP is signed, any overflow in the computation is undefined,
3238 so we don't worry about it so long as our computations on
3239 the bounds don't overflow. For unsigned, overflow is defined
3240 and this is exactly the right thing. */
3241 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3242 type, low, 0, arg1, 0);
3243 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3244 type, high, 1, arg1, 0);
3245 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3246 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3249 /* Check for an unsigned range which has wrapped around the maximum
3250 value thus making n_high < n_low, and normalize it. */
3251 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3253 low = range_binop (PLUS_EXPR, type, n_high, 0,
3254 integer_one_node, 0);
3255 high = range_binop (MINUS_EXPR, type, n_low, 0,
3256 integer_one_node, 0);
3260 low = n_low, high = n_high;
3265 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3266 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3269 if (! INTEGRAL_TYPE_P (type)
3270 || (low != 0 && ! int_fits_type_p (low, type))
3271 || (high != 0 && ! int_fits_type_p (high, type)))
3274 n_low = low, n_high = high;
3277 n_low = convert (type, n_low);
3280 n_high = convert (type, n_high);
3282 /* If we're converting from an unsigned to a signed type,
3283 we will be doing the comparison as unsigned. The tests above
3284 have already verified that LOW and HIGH are both positive.
3286 So we have to make sure that the original unsigned value will
3287 be interpreted as positive. */
3288 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3290 tree equiv_type = type_for_mode (TYPE_MODE (type), 1);
3293 /* A range without an upper bound is, naturally, unbounded.
3294 Since convert would have cropped a very large value, use
3295 the max value for the destination type. */
3297 high_positive = TYPE_MAX_VALUE (equiv_type);
3300 high_positive = TYPE_MAX_VALUE (type);
3304 high_positive = fold (build (RSHIFT_EXPR, type,
3305 convert (type, high_positive),
3306 convert (type, integer_one_node)));
3308 /* If the low bound is specified, "and" the range with the
3309 range for which the original unsigned value will be
3313 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3315 1, convert (type, integer_zero_node),
3319 in_p = (n_in_p == in_p);
3323 /* Otherwise, "or" the range with the range of the input
3324 that will be interpreted as negative. */
3325 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3327 1, convert (type, integer_zero_node),
3331 in_p = (in_p != n_in_p);
3336 low = n_low, high = n_high;
3346 /* If EXP is a constant, we can evaluate whether this is true or false. */
3347 if (TREE_CODE (exp) == INTEGER_CST)
3349 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3351 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3357 *pin_p = in_p, *plow = low, *phigh = high;
3361 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3362 type, TYPE, return an expression to test if EXP is in (or out of, depending
3363 on IN_P) the range. */
3366 build_range_check (type, exp, in_p, low, high)
3372 tree etype = TREE_TYPE (exp);
3376 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3377 return invert_truthvalue (value);
3379 else if (low == 0 && high == 0)
3380 return convert (type, integer_one_node);
3383 return fold (build (LE_EXPR, type, exp, high));
3386 return fold (build (GE_EXPR, type, exp, low));
3388 else if (operand_equal_p (low, high, 0))
3389 return fold (build (EQ_EXPR, type, exp, low));
3391 else if (TREE_UNSIGNED (etype) && integer_zerop (low))
3392 return build_range_check (type, exp, 1, 0, high);
3394 else if (integer_zerop (low))
3396 utype = unsigned_type (etype);
3397 return build_range_check (type, convert (utype, exp), 1, 0,
3398 convert (utype, high));
3401 else if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3402 && ! TREE_OVERFLOW (value))
3403 return build_range_check (type,
3404 fold (build (MINUS_EXPR, etype, exp, low)),
3405 1, convert (etype, integer_zero_node), value);
3410 /* Given two ranges, see if we can merge them into one. Return 1 if we
3411 can, 0 if we can't. Set the output range into the specified parameters. */
3414 merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
3418 tree low0, high0, low1, high1;
3426 int lowequal = ((low0 == 0 && low1 == 0)
3427 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3428 low0, 0, low1, 0)));
3429 int highequal = ((high0 == 0 && high1 == 0)
3430 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3431 high0, 1, high1, 1)));
3433 /* Make range 0 be the range that starts first, or ends last if they
3434 start at the same value. Swap them if it isn't. */
3435 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3438 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3439 high1, 1, high0, 1))))
3441 temp = in0_p, in0_p = in1_p, in1_p = temp;
3442 tem = low0, low0 = low1, low1 = tem;
3443 tem = high0, high0 = high1, high1 = tem;
3446 /* Now flag two cases, whether the ranges are disjoint or whether the
3447 second range is totally subsumed in the first. Note that the tests
3448 below are simplified by the ones above. */
3449 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3450 high0, 1, low1, 0));
3451 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3452 high1, 1, high0, 1));
3454 /* We now have four cases, depending on whether we are including or
3455 excluding the two ranges. */
3458 /* If they don't overlap, the result is false. If the second range
3459 is a subset it is the result. Otherwise, the range is from the start
3460 of the second to the end of the first. */
3462 in_p = 0, low = high = 0;
3464 in_p = 1, low = low1, high = high1;
3466 in_p = 1, low = low1, high = high0;
3469 else if (in0_p && ! in1_p)
3471 /* If they don't overlap, the result is the first range. If they are
3472 equal, the result is false. If the second range is a subset of the
3473 first, and the ranges begin at the same place, we go from just after
3474 the end of the first range to the end of the second. If the second
3475 range is not a subset of the first, or if it is a subset and both
3476 ranges end at the same place, the range starts at the start of the
3477 first range and ends just before the second range.
3478 Otherwise, we can't describe this as a single range. */
3480 in_p = 1, low = low0, high = high0;
3481 else if (lowequal && highequal)
3482 in_p = 0, low = high = 0;
3483 else if (subset && lowequal)
3485 in_p = 1, high = high0;
3486 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3487 integer_one_node, 0);
3489 else if (! subset || highequal)
3491 in_p = 1, low = low0;
3492 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3493 integer_one_node, 0);
3499 else if (! in0_p && in1_p)
3501 /* If they don't overlap, the result is the second range. If the second
3502 is a subset of the first, the result is false. Otherwise,
3503 the range starts just after the first range and ends at the
3504 end of the second. */
3506 in_p = 1, low = low1, high = high1;
3508 in_p = 0, low = high = 0;
3511 in_p = 1, high = high1;
3512 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3513 integer_one_node, 0);
3519 /* The case where we are excluding both ranges. Here the complex case
3520 is if they don't overlap. In that case, the only time we have a
3521 range is if they are adjacent. If the second is a subset of the
3522 first, the result is the first. Otherwise, the range to exclude
3523 starts at the beginning of the first range and ends at the end of the
3527 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3528 range_binop (PLUS_EXPR, NULL_TREE,
3530 integer_one_node, 1),
3532 in_p = 0, low = low0, high = high1;
3537 in_p = 0, low = low0, high = high0;
3539 in_p = 0, low = low0, high = high1;
3542 *pin_p = in_p, *plow = low, *phigh = high;
3546 /* EXP is some logical combination of boolean tests. See if we can
3547 merge it into some range test. Return the new tree if so. */
3550 fold_range_test (exp)
3553 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3554 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3555 int in0_p, in1_p, in_p;
3556 tree low0, low1, low, high0, high1, high;
3557 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3558 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3561 /* If this is an OR operation, invert both sides; we will invert
3562 again at the end. */
3564 in0_p = ! in0_p, in1_p = ! in1_p;
3566 /* If both expressions are the same, if we can merge the ranges, and we
3567 can build the range test, return it or it inverted. If one of the
3568 ranges is always true or always false, consider it to be the same
3569 expression as the other. */
3570 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3571 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3573 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3575 : rhs != 0 ? rhs : integer_zero_node,
3577 return or_op ? invert_truthvalue (tem) : tem;
3579 /* On machines where the branch cost is expensive, if this is a
3580 short-circuited branch and the underlying object on both sides
3581 is the same, make a non-short-circuit operation. */
3582 else if (BRANCH_COST >= 2
3583 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3584 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3585 && operand_equal_p (lhs, rhs, 0))
3587 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3588 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3589 which cases we can't do this. */
3590 if (simple_operand_p (lhs))
3591 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3592 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3593 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3594 TREE_OPERAND (exp, 1));
3596 else if (current_function_decl != 0
3597 && ! contains_placeholder_p (lhs))
3599 tree common = save_expr (lhs);
3601 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3602 or_op ? ! in0_p : in0_p,
3604 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3605 or_op ? ! in1_p : in1_p,
3607 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3608 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3609 TREE_TYPE (exp), lhs, rhs);
3616 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3617 bit value. Arrange things so the extra bits will be set to zero if and
3618 only if C is signed-extended to its full width. If MASK is nonzero,
3619 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3622 unextend (c, p, unsignedp, mask)
3628 tree type = TREE_TYPE (c);
3629 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3632 if (p == modesize || unsignedp)
3635 /* We work by getting just the sign bit into the low-order bit, then
3636 into the high-order bit, then sign-extend. We then XOR that value
3638 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3639 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3641 /* We must use a signed type in order to get an arithmetic right shift.
3642 However, we must also avoid introducing accidental overflows, so that
3643 a subsequent call to integer_zerop will work. Hence we must
3644 do the type conversion here. At this point, the constant is either
3645 zero or one, and the conversion to a signed type can never overflow.
3646 We could get an overflow if this conversion is done anywhere else. */
3647 if (TREE_UNSIGNED (type))
3648 temp = convert (signed_type (type), temp);
3650 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3651 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3653 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3654 /* If necessary, convert the type back to match the type of C. */
3655 if (TREE_UNSIGNED (type))
3656 temp = convert (type, temp);
3658 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3661 /* Find ways of folding logical expressions of LHS and RHS:
3662 Try to merge two comparisons to the same innermost item.
3663 Look for range tests like "ch >= '0' && ch <= '9'".
3664 Look for combinations of simple terms on machines with expensive branches
3665 and evaluate the RHS unconditionally.
3667 For example, if we have p->a == 2 && p->b == 4 and we can make an
3668 object large enough to span both A and B, we can do this with a comparison
3669 against the object ANDed with the a mask.
3671 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3672 operations to do this with one comparison.
3674 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3675 function and the one above.
3677 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3678 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3680 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3683 We return the simplified tree or 0 if no optimization is possible. */
3686 fold_truthop (code, truth_type, lhs, rhs)
3687 enum tree_code code;
3688 tree truth_type, lhs, rhs;
3690 /* If this is the "or" of two comparisons, we can do something if we
3691 the comparisons are NE_EXPR. If this is the "and", we can do something
3692 if the comparisons are EQ_EXPR. I.e.,
3693 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3695 WANTED_CODE is this operation code. For single bit fields, we can
3696 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3697 comparison for one-bit fields. */
3699 enum tree_code wanted_code;
3700 enum tree_code lcode, rcode;
3701 tree ll_arg, lr_arg, rl_arg, rr_arg;
3702 tree ll_inner, lr_inner, rl_inner, rr_inner;
3703 int ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3704 int rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3705 int xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3706 int lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3707 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3708 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3709 enum machine_mode lnmode, rnmode;
3710 tree ll_mask, lr_mask, rl_mask, rr_mask;
3711 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3712 tree l_const, r_const;
3714 int first_bit, end_bit;
3717 /* Start by getting the comparison codes. Fail if anything is volatile.
3718 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3719 it were surrounded with a NE_EXPR. */
3721 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3724 lcode = TREE_CODE (lhs);
3725 rcode = TREE_CODE (rhs);
3727 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3728 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3730 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3731 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3733 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3736 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3737 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3739 ll_arg = TREE_OPERAND (lhs, 0);
3740 lr_arg = TREE_OPERAND (lhs, 1);
3741 rl_arg = TREE_OPERAND (rhs, 0);
3742 rr_arg = TREE_OPERAND (rhs, 1);
3744 /* If the RHS can be evaluated unconditionally and its operands are
3745 simple, it wins to evaluate the RHS unconditionally on machines
3746 with expensive branches. In this case, this isn't a comparison
3747 that can be merged. */
3749 /* @@ I'm not sure it wins on the m88110 to do this if the comparisons
3750 are with zero (tmw). */
3752 if (BRANCH_COST >= 2
3753 && INTEGRAL_TYPE_P (TREE_TYPE (rhs))
3754 && simple_operand_p (rl_arg)
3755 && simple_operand_p (rr_arg))
3756 return build (code, truth_type, lhs, rhs);
3758 /* See if the comparisons can be merged. Then get all the parameters for
3761 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3762 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3766 ll_inner = decode_field_reference (ll_arg,
3767 &ll_bitsize, &ll_bitpos, &ll_mode,
3768 &ll_unsignedp, &volatilep, &ll_mask,
3770 lr_inner = decode_field_reference (lr_arg,
3771 &lr_bitsize, &lr_bitpos, &lr_mode,
3772 &lr_unsignedp, &volatilep, &lr_mask,
3774 rl_inner = decode_field_reference (rl_arg,
3775 &rl_bitsize, &rl_bitpos, &rl_mode,
3776 &rl_unsignedp, &volatilep, &rl_mask,
3778 rr_inner = decode_field_reference (rr_arg,
3779 &rr_bitsize, &rr_bitpos, &rr_mode,
3780 &rr_unsignedp, &volatilep, &rr_mask,
3783 /* It must be true that the inner operation on the lhs of each
3784 comparison must be the same if we are to be able to do anything.
3785 Then see if we have constants. If not, the same must be true for
3787 if (volatilep || ll_inner == 0 || rl_inner == 0
3788 || ! operand_equal_p (ll_inner, rl_inner, 0))
3791 if (TREE_CODE (lr_arg) == INTEGER_CST
3792 && TREE_CODE (rr_arg) == INTEGER_CST)
3793 l_const = lr_arg, r_const = rr_arg;
3794 else if (lr_inner == 0 || rr_inner == 0
3795 || ! operand_equal_p (lr_inner, rr_inner, 0))
3798 l_const = r_const = 0;
3800 /* If either comparison code is not correct for our logical operation,
3801 fail. However, we can convert a one-bit comparison against zero into
3802 the opposite comparison against that bit being set in the field. */
3804 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
3805 if (lcode != wanted_code)
3807 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
3809 if (ll_unsignedp || tree_log2 (ll_mask) + 1 < ll_bitsize)
3812 /* Since ll_arg is a single bit bit mask, we can sign extend
3813 it appropriately with a NEGATE_EXPR.
3814 l_const is made a signed value here, but since for l_const != NULL
3815 lr_unsignedp is not used, we don't need to clear the latter. */
3816 l_const = fold (build1 (NEGATE_EXPR, TREE_TYPE (ll_arg),
3817 convert (TREE_TYPE (ll_arg), ll_mask)));
3823 if (rcode != wanted_code)
3825 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
3827 if (rl_unsignedp || tree_log2 (rl_mask) + 1 < rl_bitsize)
3830 /* This is analogous to the code for l_const above. */
3831 r_const = fold (build1 (NEGATE_EXPR, TREE_TYPE (rl_arg),
3832 convert (TREE_TYPE (rl_arg), rl_mask)));
3838 /* See if we can find a mode that contains both fields being compared on
3839 the left. If we can't, fail. Otherwise, update all constants and masks
3840 to be relative to a field of that size. */
3841 first_bit = MIN (ll_bitpos, rl_bitpos);
3842 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
3843 lnmode = get_best_mode (end_bit - first_bit, first_bit,
3844 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
3846 if (lnmode == VOIDmode)
3849 lnbitsize = GET_MODE_BITSIZE (lnmode);
3850 lnbitpos = first_bit & ~ (lnbitsize - 1);
3851 type = type_for_size (lnbitsize, 1);
3852 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
3854 if (BYTES_BIG_ENDIAN)
3856 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
3857 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
3860 ll_mask = const_binop (LSHIFT_EXPR, convert (type, ll_mask),
3861 size_int (xll_bitpos), 0);
3862 rl_mask = const_binop (LSHIFT_EXPR, convert (type, rl_mask),
3863 size_int (xrl_bitpos), 0);
3867 l_const = convert (type, l_const);
3868 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
3869 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
3870 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
3871 fold (build1 (BIT_NOT_EXPR,
3875 warning ("comparison is always %d", wanted_code == NE_EXPR);
3877 return convert (truth_type,
3878 wanted_code == NE_EXPR
3879 ? integer_one_node : integer_zero_node);
3884 r_const = convert (type, r_const);
3885 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
3886 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
3887 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
3888 fold (build1 (BIT_NOT_EXPR,
3892 warning ("comparison is always %d", wanted_code == NE_EXPR);
3894 return convert (truth_type,
3895 wanted_code == NE_EXPR
3896 ? integer_one_node : integer_zero_node);
3900 /* If the right sides are not constant, do the same for it. Also,
3901 disallow this optimization if a size or signedness mismatch occurs
3902 between the left and right sides. */
3905 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
3906 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
3907 /* Make sure the two fields on the right
3908 correspond to the left without being swapped. */
3909 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
3912 first_bit = MIN (lr_bitpos, rr_bitpos);
3913 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
3914 rnmode = get_best_mode (end_bit - first_bit, first_bit,
3915 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
3917 if (rnmode == VOIDmode)
3920 rnbitsize = GET_MODE_BITSIZE (rnmode);
3921 rnbitpos = first_bit & ~ (rnbitsize - 1);
3922 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
3924 if (BYTES_BIG_ENDIAN)
3926 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
3927 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
3930 lr_mask = const_binop (LSHIFT_EXPR, convert (type, lr_mask),
3931 size_int (xlr_bitpos), 0);
3932 rr_mask = const_binop (LSHIFT_EXPR, convert (type, rr_mask),
3933 size_int (xrr_bitpos), 0);
3935 /* Make a mask that corresponds to both fields being compared.
3936 Do this for both items being compared. If the masks agree,
3937 and the bits being compared are in the same position, then
3938 we can do this by masking both and comparing the masked
3940 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3941 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
3942 if (operand_equal_p (ll_mask, lr_mask, 0)
3943 && lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
3945 lhs = make_bit_field_ref (ll_inner, type, lnbitsize, lnbitpos,
3946 ll_unsignedp || rl_unsignedp);
3947 rhs = make_bit_field_ref (lr_inner, type, rnbitsize, rnbitpos,
3948 lr_unsignedp || rr_unsignedp);
3949 if (! all_ones_mask_p (ll_mask, lnbitsize))
3951 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
3952 rhs = build (BIT_AND_EXPR, type, rhs, ll_mask);
3954 return build (wanted_code, truth_type, lhs, rhs);
3957 /* There is still another way we can do something: If both pairs of
3958 fields being compared are adjacent, we may be able to make a wider
3959 field containing them both. */
3960 if ((ll_bitsize + ll_bitpos == rl_bitpos
3961 && lr_bitsize + lr_bitpos == rr_bitpos)
3962 || (ll_bitpos == rl_bitpos + rl_bitsize
3963 && lr_bitpos == rr_bitpos + rr_bitsize))
3964 return build (wanted_code, truth_type,
3965 make_bit_field_ref (ll_inner, type,
3966 ll_bitsize + rl_bitsize,
3967 MIN (ll_bitpos, rl_bitpos),
3969 make_bit_field_ref (lr_inner, type,
3970 lr_bitsize + rr_bitsize,
3971 MIN (lr_bitpos, rr_bitpos),
3977 /* Handle the case of comparisons with constants. If there is something in
3978 common between the masks, those bits of the constants must be the same.
3979 If not, the condition is always false. Test for this to avoid generating
3980 incorrect code below. */
3981 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
3982 if (! integer_zerop (result)
3983 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
3984 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
3986 if (wanted_code == NE_EXPR)
3988 warning ("`or' of unmatched not-equal tests is always 1");
3989 return convert (truth_type, integer_one_node);
3993 warning ("`and' of mutually exclusive equal-tests is always 0");
3994 return convert (truth_type, integer_zero_node);
3998 /* Construct the expression we will return. First get the component
3999 reference we will make. Unless the mask is all ones the width of
4000 that field, perform the mask operation. Then compare with the
4002 result = make_bit_field_ref (ll_inner, type, lnbitsize, lnbitpos,
4003 ll_unsignedp || rl_unsignedp);
4005 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4006 if (! all_ones_mask_p (ll_mask, lnbitsize))
4007 result = build (BIT_AND_EXPR, type, result, ll_mask);
4009 return build (wanted_code, truth_type, result,
4010 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4013 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4014 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4015 that we may sometimes modify the tree. */
4018 strip_compound_expr (t, s)
4022 enum tree_code code = TREE_CODE (t);
4024 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4025 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4026 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4027 return TREE_OPERAND (t, 1);
4029 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4030 don't bother handling any other types. */
4031 else if (code == COND_EXPR)
4033 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4034 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4035 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4037 else if (TREE_CODE_CLASS (code) == '1')
4038 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4039 else if (TREE_CODE_CLASS (code) == '<'
4040 || TREE_CODE_CLASS (code) == '2')
4042 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4043 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4049 /* Return a node which has the indicated constant VALUE (either 0 or
4050 1), and is of the indicated TYPE. */
4053 constant_boolean_node (value, type)
4057 if (type == integer_type_node)
4058 return value ? integer_one_node : integer_zero_node;
4059 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4060 return truthvalue_conversion (value ? integer_one_node :
4064 tree t = build_int_2 (value, 0);
4065 TREE_TYPE (t) = type;
4070 /* Utility function for the following routine, to see how complex a nesting of
4071 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4072 we don't care (to avoid spending too much time on complex expressions.). */
4075 count_cond (expr, lim)
4081 if (TREE_CODE (expr) != COND_EXPR)
4086 true = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4087 false = count_cond (TREE_OPERAND (expr, 2), lim - 1 - true);
4088 return MIN (lim, 1 + true + false);
4091 /* Perform constant folding and related simplification of EXPR.
4092 The related simplifications include x*1 => x, x*0 => 0, etc.,
4093 and application of the associative law.
4094 NOP_EXPR conversions may be removed freely (as long as we
4095 are careful not to change the C type of the overall expression)
4096 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4097 but we can constant-fold them if they have constant operands. */
4103 register tree t = expr;
4104 tree t1 = NULL_TREE;
4106 tree type = TREE_TYPE (expr);
4107 register tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4108 register enum tree_code code = TREE_CODE (t);
4112 /* WINS will be nonzero when the switch is done
4113 if all operands are constant. */
4117 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4118 Likewise for a SAVE_EXPR that's already been evaluated. */
4119 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t)) != 0)
4122 /* Return right away if already constant. */
4123 if (TREE_CONSTANT (t))
4125 if (code == CONST_DECL)
4126 return DECL_INITIAL (t);
4130 #ifdef MAX_INTEGER_COMPUTATION_MODE
4131 check_max_integer_computation_mode (expr);
4134 kind = TREE_CODE_CLASS (code);
4135 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4139 /* Special case for conversion ops that can have fixed point args. */
4140 arg0 = TREE_OPERAND (t, 0);
4142 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4144 STRIP_TYPE_NOPS (arg0);
4146 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4147 subop = TREE_REALPART (arg0);
4151 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4152 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4153 && TREE_CODE (subop) != REAL_CST
4154 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4156 /* Note that TREE_CONSTANT isn't enough:
4157 static var addresses are constant but we can't
4158 do arithmetic on them. */
4161 else if (kind == 'e' || kind == '<'
4162 || kind == '1' || kind == '2' || kind == 'r')
4164 register int len = tree_code_length[(int) code];
4166 for (i = 0; i < len; i++)
4168 tree op = TREE_OPERAND (t, i);
4172 continue; /* Valid for CALL_EXPR, at least. */
4174 if (kind == '<' || code == RSHIFT_EXPR)
4176 /* Signedness matters here. Perhaps we can refine this
4178 STRIP_TYPE_NOPS (op);
4182 /* Strip any conversions that don't change the mode. */
4186 if (TREE_CODE (op) == COMPLEX_CST)
4187 subop = TREE_REALPART (op);
4191 if (TREE_CODE (subop) != INTEGER_CST
4192 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4193 && TREE_CODE (subop) != REAL_CST
4194 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4196 /* Note that TREE_CONSTANT isn't enough:
4197 static var addresses are constant but we can't
4198 do arithmetic on them. */
4208 /* If this is a commutative operation, and ARG0 is a constant, move it
4209 to ARG1 to reduce the number of tests below. */
4210 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
4211 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
4212 || code == BIT_AND_EXPR)
4213 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
4215 tem = arg0; arg0 = arg1; arg1 = tem;
4217 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
4218 TREE_OPERAND (t, 1) = tem;
4221 /* Now WINS is set as described above,
4222 ARG0 is the first operand of EXPR,
4223 and ARG1 is the second operand (if it has more than one operand).
4225 First check for cases where an arithmetic operation is applied to a
4226 compound, conditional, or comparison operation. Push the arithmetic
4227 operation inside the compound or conditional to see if any folding
4228 can then be done. Convert comparison to conditional for this purpose.
4229 The also optimizes non-constant cases that used to be done in
4232 Before we do that, see if this is a BIT_AND_EXPR or a BIT_OR_EXPR,
4233 one of the operands is a comparison and the other is a comparison, a
4234 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
4235 code below would make the expression more complex. Change it to a
4236 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
4237 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
4239 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
4240 || code == EQ_EXPR || code == NE_EXPR)
4241 && ((truth_value_p (TREE_CODE (arg0))
4242 && (truth_value_p (TREE_CODE (arg1))
4243 || (TREE_CODE (arg1) == BIT_AND_EXPR
4244 && integer_onep (TREE_OPERAND (arg1, 1)))))
4245 || (truth_value_p (TREE_CODE (arg1))
4246 && (truth_value_p (TREE_CODE (arg0))
4247 || (TREE_CODE (arg0) == BIT_AND_EXPR
4248 && integer_onep (TREE_OPERAND (arg0, 1)))))))
4250 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
4251 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
4255 if (code == EQ_EXPR)
4256 t = invert_truthvalue (t);
4261 if (TREE_CODE_CLASS (code) == '1')
4263 if (TREE_CODE (arg0) == COMPOUND_EXPR)
4264 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4265 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
4266 else if (TREE_CODE (arg0) == COND_EXPR)
4268 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
4269 fold (build1 (code, type, TREE_OPERAND (arg0, 1))),
4270 fold (build1 (code, type, TREE_OPERAND (arg0, 2)))));
4272 /* If this was a conversion, and all we did was to move into
4273 inside the COND_EXPR, bring it back out. But leave it if
4274 it is a conversion from integer to integer and the
4275 result precision is no wider than a word since such a
4276 conversion is cheap and may be optimized away by combine,
4277 while it couldn't if it were outside the COND_EXPR. Then return
4278 so we don't get into an infinite recursion loop taking the
4279 conversion out and then back in. */
4281 if ((code == NOP_EXPR || code == CONVERT_EXPR
4282 || code == NON_LVALUE_EXPR)
4283 && TREE_CODE (t) == COND_EXPR
4284 && TREE_CODE (TREE_OPERAND (t, 1)) == code
4285 && TREE_CODE (TREE_OPERAND (t, 2)) == code
4286 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
4287 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
4288 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
4289 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0)))
4290 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
4291 t = build1 (code, type,
4293 TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0)),
4294 TREE_OPERAND (t, 0),
4295 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
4296 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
4299 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
4300 return fold (build (COND_EXPR, type, arg0,
4301 fold (build1 (code, type, integer_one_node)),
4302 fold (build1 (code, type, integer_zero_node))));
4304 else if (TREE_CODE_CLASS (code) == '2'
4305 || TREE_CODE_CLASS (code) == '<')
4307 if (TREE_CODE (arg1) == COMPOUND_EXPR)
4308 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4309 fold (build (code, type,
4310 arg0, TREE_OPERAND (arg1, 1))));
4311 else if ((TREE_CODE (arg1) == COND_EXPR
4312 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
4313 && TREE_CODE_CLASS (code) != '<'))
4314 && (TREE_CODE (arg0) != COND_EXPR
4315 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4316 && (! TREE_SIDE_EFFECTS (arg0)
4317 || (current_function_decl != 0
4318 && ! contains_placeholder_p (arg0))))
4320 tree test, true_value, false_value;
4321 tree lhs = 0, rhs = 0;
4323 if (TREE_CODE (arg1) == COND_EXPR)
4325 test = TREE_OPERAND (arg1, 0);
4326 true_value = TREE_OPERAND (arg1, 1);
4327 false_value = TREE_OPERAND (arg1, 2);
4331 tree testtype = TREE_TYPE (arg1);
4333 true_value = convert (testtype, integer_one_node);
4334 false_value = convert (testtype, integer_zero_node);
4337 /* If ARG0 is complex we want to make sure we only evaluate
4338 it once. Though this is only required if it is volatile, it
4339 might be more efficient even if it is not. However, if we
4340 succeed in folding one part to a constant, we do not need
4341 to make this SAVE_EXPR. Since we do this optimization
4342 primarily to see if we do end up with constant and this
4343 SAVE_EXPR interferes with later optimizations, suppressing
4344 it when we can is important.
4346 If we are not in a function, we can't make a SAVE_EXPR, so don't
4347 try to do so. Don't try to see if the result is a constant
4348 if an arm is a COND_EXPR since we get exponential behavior
4351 if (TREE_CODE (arg0) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4352 && current_function_decl != 0
4353 && ((TREE_CODE (arg0) != VAR_DECL
4354 && TREE_CODE (arg0) != PARM_DECL)
4355 || TREE_SIDE_EFFECTS (arg0)))
4357 if (TREE_CODE (true_value) != COND_EXPR)
4358 lhs = fold (build (code, type, arg0, true_value));
4360 if (TREE_CODE (false_value) != COND_EXPR)
4361 rhs = fold (build (code, type, arg0, false_value));
4363 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4364 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4365 arg0 = save_expr (arg0), lhs = rhs = 0;
4369 lhs = fold (build (code, type, arg0, true_value));
4371 rhs = fold (build (code, type, arg0, false_value));
4373 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4375 if (TREE_CODE (arg0) == SAVE_EXPR)
4376 return build (COMPOUND_EXPR, type,
4377 convert (void_type_node, arg0),
4378 strip_compound_expr (test, arg0));
4380 return convert (type, test);
4383 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
4384 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4385 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4386 else if ((TREE_CODE (arg0) == COND_EXPR
4387 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
4388 && TREE_CODE_CLASS (code) != '<'))
4389 && (TREE_CODE (arg1) != COND_EXPR
4390 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4391 && (! TREE_SIDE_EFFECTS (arg1)
4392 || (current_function_decl != 0
4393 && ! contains_placeholder_p (arg1))))
4395 tree test, true_value, false_value;
4396 tree lhs = 0, rhs = 0;
4398 if (TREE_CODE (arg0) == COND_EXPR)
4400 test = TREE_OPERAND (arg0, 0);
4401 true_value = TREE_OPERAND (arg0, 1);
4402 false_value = TREE_OPERAND (arg0, 2);
4406 tree testtype = TREE_TYPE (arg0);
4408 true_value = convert (testtype, integer_one_node);
4409 false_value = convert (testtype, integer_zero_node);
4412 if (TREE_CODE (arg1) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4413 && current_function_decl != 0
4414 && ((TREE_CODE (arg1) != VAR_DECL
4415 && TREE_CODE (arg1) != PARM_DECL)
4416 || TREE_SIDE_EFFECTS (arg1)))
4418 if (TREE_CODE (true_value) != COND_EXPR)
4419 lhs = fold (build (code, type, true_value, arg1));
4421 if (TREE_CODE (false_value) != COND_EXPR)
4422 rhs = fold (build (code, type, false_value, arg1));
4424 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4425 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4426 arg1 = save_expr (arg1), lhs = rhs = 0;
4430 lhs = fold (build (code, type, true_value, arg1));
4433 rhs = fold (build (code, type, false_value, arg1));
4435 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4436 if (TREE_CODE (arg1) == SAVE_EXPR)
4437 return build (COMPOUND_EXPR, type,
4438 convert (void_type_node, arg1),
4439 strip_compound_expr (test, arg1));
4441 return convert (type, test);
4444 else if (TREE_CODE_CLASS (code) == '<'
4445 && TREE_CODE (arg0) == COMPOUND_EXPR)
4446 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4447 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4448 else if (TREE_CODE_CLASS (code) == '<'
4449 && TREE_CODE (arg1) == COMPOUND_EXPR)
4450 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4451 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
4463 return fold (DECL_INITIAL (t));
4468 case FIX_TRUNC_EXPR:
4469 /* Other kinds of FIX are not handled properly by fold_convert. */
4471 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
4472 return TREE_OPERAND (t, 0);
4474 /* Handle cases of two conversions in a row. */
4475 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
4476 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
4478 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4479 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
4480 tree final_type = TREE_TYPE (t);
4481 int inside_int = INTEGRAL_TYPE_P (inside_type);
4482 int inside_ptr = POINTER_TYPE_P (inside_type);
4483 int inside_float = FLOAT_TYPE_P (inside_type);
4484 int inside_prec = TYPE_PRECISION (inside_type);
4485 int inside_unsignedp = TREE_UNSIGNED (inside_type);
4486 int inter_int = INTEGRAL_TYPE_P (inter_type);
4487 int inter_ptr = POINTER_TYPE_P (inter_type);
4488 int inter_float = FLOAT_TYPE_P (inter_type);
4489 int inter_prec = TYPE_PRECISION (inter_type);
4490 int inter_unsignedp = TREE_UNSIGNED (inter_type);
4491 int final_int = INTEGRAL_TYPE_P (final_type);
4492 int final_ptr = POINTER_TYPE_P (final_type);
4493 int final_float = FLOAT_TYPE_P (final_type);
4494 int final_prec = TYPE_PRECISION (final_type);
4495 int final_unsignedp = TREE_UNSIGNED (final_type);
4497 /* In addition to the cases of two conversions in a row
4498 handled below, if we are converting something to its own
4499 type via an object of identical or wider precision, neither
4500 conversion is needed. */
4501 if (inside_type == final_type
4502 && ((inter_int && final_int) || (inter_float && final_float))
4503 && inter_prec >= final_prec)
4504 return TREE_OPERAND (TREE_OPERAND (t, 0), 0);
4506 /* Likewise, if the intermediate and final types are either both
4507 float or both integer, we don't need the middle conversion if
4508 it is wider than the final type and doesn't change the signedness
4509 (for integers). Avoid this if the final type is a pointer
4510 since then we sometimes need the inner conversion. Likewise if
4511 the outer has a precision not equal to the size of its mode. */
4512 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
4513 || (inter_float && inside_float))
4514 && inter_prec >= inside_prec
4515 && (inter_float || inter_unsignedp == inside_unsignedp)
4516 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
4517 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
4519 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4521 /* If we have a sign-extension of a zero-extended value, we can
4522 replace that by a single zero-extension. */
4523 if (inside_int && inter_int && final_int
4524 && inside_prec < inter_prec && inter_prec < final_prec
4525 && inside_unsignedp && !inter_unsignedp)
4526 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4528 /* Two conversions in a row are not needed unless:
4529 - some conversion is floating-point (overstrict for now), or
4530 - the intermediate type is narrower than both initial and
4532 - the intermediate type and innermost type differ in signedness,
4533 and the outermost type is wider than the intermediate, or
4534 - the initial type is a pointer type and the precisions of the
4535 intermediate and final types differ, or
4536 - the final type is a pointer type and the precisions of the
4537 initial and intermediate types differ. */
4538 if (! inside_float && ! inter_float && ! final_float
4539 && (inter_prec > inside_prec || inter_prec > final_prec)
4540 && ! (inside_int && inter_int
4541 && inter_unsignedp != inside_unsignedp
4542 && inter_prec < final_prec)
4543 && ((inter_unsignedp && inter_prec > inside_prec)
4544 == (final_unsignedp && final_prec > inter_prec))
4545 && ! (inside_ptr && inter_prec != final_prec)
4546 && ! (final_ptr && inside_prec != inter_prec)
4547 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
4548 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
4550 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4553 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
4554 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
4555 /* Detect assigning a bitfield. */
4556 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
4557 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
4559 /* Don't leave an assignment inside a conversion
4560 unless assigning a bitfield. */
4561 tree prev = TREE_OPERAND (t, 0);
4562 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
4563 /* First do the assignment, then return converted constant. */
4564 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
4570 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
4573 return fold_convert (t, arg0);
4575 #if 0 /* This loses on &"foo"[0]. */
4580 /* Fold an expression like: "foo"[2] */
4581 if (TREE_CODE (arg0) == STRING_CST
4582 && TREE_CODE (arg1) == INTEGER_CST
4583 && !TREE_INT_CST_HIGH (arg1)
4584 && (i = TREE_INT_CST_LOW (arg1)) < TREE_STRING_LENGTH (arg0))
4586 t = build_int_2 (TREE_STRING_POINTER (arg0)[i], 0);
4587 TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (arg0));
4588 force_fit_type (t, 0);
4595 if (TREE_CODE (arg0) == CONSTRUCTOR)
4597 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
4604 TREE_CONSTANT (t) = wins;
4610 if (TREE_CODE (arg0) == INTEGER_CST)
4612 HOST_WIDE_INT low, high;
4613 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
4614 TREE_INT_CST_HIGH (arg0),
4616 t = build_int_2 (low, high);
4617 TREE_TYPE (t) = type;
4619 = (TREE_OVERFLOW (arg0)
4620 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
4621 TREE_CONSTANT_OVERFLOW (t)
4622 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
4624 else if (TREE_CODE (arg0) == REAL_CST)
4625 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
4627 else if (TREE_CODE (arg0) == NEGATE_EXPR)
4628 return TREE_OPERAND (arg0, 0);
4630 /* Convert - (a - b) to (b - a) for non-floating-point. */
4631 else if (TREE_CODE (arg0) == MINUS_EXPR && ! FLOAT_TYPE_P (type))
4632 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
4633 TREE_OPERAND (arg0, 0));
4640 if (TREE_CODE (arg0) == INTEGER_CST)
4642 if (! TREE_UNSIGNED (type)
4643 && TREE_INT_CST_HIGH (arg0) < 0)
4645 HOST_WIDE_INT low, high;
4646 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
4647 TREE_INT_CST_HIGH (arg0),
4649 t = build_int_2 (low, high);
4650 TREE_TYPE (t) = type;
4652 = (TREE_OVERFLOW (arg0)
4653 | force_fit_type (t, overflow));
4654 TREE_CONSTANT_OVERFLOW (t)
4655 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
4658 else if (TREE_CODE (arg0) == REAL_CST)
4660 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
4661 t = build_real (type,
4662 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
4665 else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR)
4666 return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
4670 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
4672 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
4673 return build (COMPLEX_EXPR, TREE_TYPE (arg0),
4674 TREE_OPERAND (arg0, 0),
4675 fold (build1 (NEGATE_EXPR,
4676 TREE_TYPE (TREE_TYPE (arg0)),
4677 TREE_OPERAND (arg0, 1))));
4678 else if (TREE_CODE (arg0) == COMPLEX_CST)
4679 return build_complex (type, TREE_OPERAND (arg0, 0),
4680 fold (build1 (NEGATE_EXPR,
4681 TREE_TYPE (TREE_TYPE (arg0)),
4682 TREE_OPERAND (arg0, 1))));
4683 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
4684 return fold (build (TREE_CODE (arg0), type,
4685 fold (build1 (CONJ_EXPR, type,
4686 TREE_OPERAND (arg0, 0))),
4687 fold (build1 (CONJ_EXPR,
4688 type, TREE_OPERAND (arg0, 1)))));
4689 else if (TREE_CODE (arg0) == CONJ_EXPR)
4690 return TREE_OPERAND (arg0, 0);
4696 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
4697 ~ TREE_INT_CST_HIGH (arg0));
4698 TREE_TYPE (t) = type;
4699 force_fit_type (t, 0);
4700 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
4701 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
4703 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
4704 return TREE_OPERAND (arg0, 0);
4708 /* A + (-B) -> A - B */
4709 if (TREE_CODE (arg1) == NEGATE_EXPR)
4710 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
4711 else if (! FLOAT_TYPE_P (type))
4713 if (integer_zerop (arg1))
4714 return non_lvalue (convert (type, arg0));
4716 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
4717 with a constant, and the two constants have no bits in common,
4718 we should treat this as a BIT_IOR_EXPR since this may produce more
4720 if (TREE_CODE (arg0) == BIT_AND_EXPR
4721 && TREE_CODE (arg1) == BIT_AND_EXPR
4722 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
4723 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
4724 && integer_zerop (const_binop (BIT_AND_EXPR,
4725 TREE_OPERAND (arg0, 1),
4726 TREE_OPERAND (arg1, 1), 0)))
4728 code = BIT_IOR_EXPR;
4732 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
4734 tree arg00, arg01, arg10, arg11;
4735 tree alt0, alt1, same;
4737 /* (A * C) + (B * C) -> (A+B) * C.
4738 We are most concerned about the case where C is a constant,
4739 but other combinations show up during loop reduction. Since
4740 it is not difficult, try all four possibilities. */
4742 arg00 = TREE_OPERAND (arg0, 0);
4743 arg01 = TREE_OPERAND (arg0, 1);
4744 arg10 = TREE_OPERAND (arg1, 0);
4745 arg11 = TREE_OPERAND (arg1, 1);
4748 if (operand_equal_p (arg01, arg11, 0))
4749 same = arg01, alt0 = arg00, alt1 = arg10;
4750 else if (operand_equal_p (arg00, arg10, 0))
4751 same = arg00, alt0 = arg01, alt1 = arg11;
4752 else if (operand_equal_p (arg00, arg11, 0))
4753 same = arg00, alt0 = arg01, alt1 = arg10;
4754 else if (operand_equal_p (arg01, arg10, 0))
4755 same = arg01, alt0 = arg00, alt1 = arg11;
4758 return fold (build (MULT_EXPR, type,
4759 fold (build (PLUS_EXPR, type, alt0, alt1)),
4763 /* In IEEE floating point, x+0 may not equal x. */
4764 else if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
4766 && real_zerop (arg1))
4767 return non_lvalue (convert (type, arg0));
4769 /* In most languages, can't associate operations on floats
4770 through parentheses. Rather than remember where the parentheses
4771 were, we don't associate floats at all. It shouldn't matter much.
4772 However, associating multiplications is only very slightly
4773 inaccurate, so do that if -ffast-math is specified. */
4774 if (FLOAT_TYPE_P (type)
4775 && ! (flag_fast_math && code == MULT_EXPR))
4778 /* The varsign == -1 cases happen only for addition and subtraction.
4779 It says that the arg that was split was really CON minus VAR.
4780 The rest of the code applies to all associative operations. */
4786 if (split_tree (arg0, code, &var, &con, &varsign))
4790 /* EXPR is (CON-VAR) +- ARG1. */
4791 /* If it is + and VAR==ARG1, return just CONST. */
4792 if (code == PLUS_EXPR && operand_equal_p (var, arg1, 0))
4793 return convert (TREE_TYPE (t), con);
4795 /* If ARG0 is a constant, don't change things around;
4796 instead keep all the constant computations together. */
4798 if (TREE_CONSTANT (arg0))
4801 /* Otherwise return (CON +- ARG1) - VAR. */
4802 t = build (MINUS_EXPR, type,
4803 fold (build (code, type, con, arg1)), var);
4807 /* EXPR is (VAR+CON) +- ARG1. */
4808 /* If it is - and VAR==ARG1, return just CONST. */
4809 if (code == MINUS_EXPR && operand_equal_p (var, arg1, 0))
4810 return convert (TREE_TYPE (t), con);
4812 /* If ARG0 is a constant, don't change things around;
4813 instead keep all the constant computations together. */
4815 if (TREE_CONSTANT (arg0))
4818 /* Otherwise return VAR +- (ARG1 +- CON). */
4819 tem = fold (build (code, type, arg1, con));
4820 t = build (code, type, var, tem);
4822 if (integer_zerop (tem)
4823 && (code == PLUS_EXPR || code == MINUS_EXPR))
4824 return convert (type, var);
4825 /* If we have x +/- (c - d) [c an explicit integer]
4826 change it to x -/+ (d - c) since if d is relocatable
4827 then the latter can be a single immediate insn
4828 and the former cannot. */
4829 if (TREE_CODE (tem) == MINUS_EXPR
4830 && TREE_CODE (TREE_OPERAND (tem, 0)) == INTEGER_CST)
4832 tree tem1 = TREE_OPERAND (tem, 1);
4833 TREE_OPERAND (tem, 1) = TREE_OPERAND (tem, 0);
4834 TREE_OPERAND (tem, 0) = tem1;
4836 (code == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR));
4842 if (split_tree (arg1, code, &var, &con, &varsign))
4844 if (TREE_CONSTANT (arg1))
4849 (code == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR));
4851 /* EXPR is ARG0 +- (CON +- VAR). */
4852 if (TREE_CODE (t) == MINUS_EXPR
4853 && operand_equal_p (var, arg0, 0))
4855 /* If VAR and ARG0 cancel, return just CON or -CON. */
4856 if (code == PLUS_EXPR)
4857 return convert (TREE_TYPE (t), con);
4858 return fold (build1 (NEGATE_EXPR, TREE_TYPE (t),
4859 convert (TREE_TYPE (t), con)));
4862 t = build (TREE_CODE (t), type,
4863 fold (build (code, TREE_TYPE (t), arg0, con)), var);
4865 if (integer_zerop (TREE_OPERAND (t, 0))
4866 && TREE_CODE (t) == PLUS_EXPR)
4867 return convert (TREE_TYPE (t), var);
4872 #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
4873 if (TREE_CODE (arg1) == REAL_CST)
4875 #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
4877 t1 = const_binop (code, arg0, arg1, 0);
4878 if (t1 != NULL_TREE)
4880 /* The return value should always have
4881 the same type as the original expression. */
4882 if (TREE_TYPE (t1) != TREE_TYPE (t))
4883 t1 = convert (TREE_TYPE (t), t1);
4890 if (! FLOAT_TYPE_P (type))
4892 if (! wins && integer_zerop (arg0))
4893 return build1 (NEGATE_EXPR, type, arg1);
4894 if (integer_zerop (arg1))
4895 return non_lvalue (convert (type, arg0));
4897 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
4898 about the case where C is a constant, just try one of the
4899 four possibilities. */
4901 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
4902 && operand_equal_p (TREE_OPERAND (arg0, 1),
4903 TREE_OPERAND (arg1, 1), 0))
4904 return fold (build (MULT_EXPR, type,
4905 fold (build (MINUS_EXPR, type,
4906 TREE_OPERAND (arg0, 0),
4907 TREE_OPERAND (arg1, 0))),
4908 TREE_OPERAND (arg0, 1)));
4910 /* Convert A - (-B) to A + B. */
4911 else if (TREE_CODE (arg1) == NEGATE_EXPR)
4912 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
4914 else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
4917 /* Except with IEEE floating point, 0-x equals -x. */
4918 if (! wins && real_zerop (arg0))
4919 return build1 (NEGATE_EXPR, type, arg1);
4920 /* Except with IEEE floating point, x-0 equals x. */
4921 if (real_zerop (arg1))
4922 return non_lvalue (convert (type, arg0));
4925 /* Fold &x - &x. This can happen from &x.foo - &x.
4926 This is unsafe for certain floats even in non-IEEE formats.
4927 In IEEE, it is unsafe because it does wrong for NaNs.
4928 Also note that operand_equal_p is always false if an operand
4931 if ((! FLOAT_TYPE_P (type) || flag_fast_math)
4932 && operand_equal_p (arg0, arg1, 0))
4933 return convert (type, integer_zero_node);
4938 if (! FLOAT_TYPE_P (type))
4940 if (integer_zerop (arg1))
4941 return omit_one_operand (type, arg1, arg0);
4942 if (integer_onep (arg1))
4943 return non_lvalue (convert (type, arg0));
4945 /* ((A / C) * C) is A if the division is an
4946 EXACT_DIV_EXPR. Since C is normally a constant,
4947 just check for one of the four possibilities. */
4949 if (TREE_CODE (arg0) == EXACT_DIV_EXPR
4950 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
4951 return TREE_OPERAND (arg0, 0);
4953 /* (a * (1 << b)) is (a << b) */
4954 if (TREE_CODE (arg1) == LSHIFT_EXPR
4955 && integer_onep (TREE_OPERAND (arg1, 0)))
4956 return fold (build (LSHIFT_EXPR, type, arg0,
4957 TREE_OPERAND (arg1, 1)));
4958 if (TREE_CODE (arg0) == LSHIFT_EXPR
4959 && integer_onep (TREE_OPERAND (arg0, 0)))
4960 return fold (build (LSHIFT_EXPR, type, arg1,
4961 TREE_OPERAND (arg0, 1)));
4965 /* x*0 is 0, except for IEEE floating point. */
4966 if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
4968 && real_zerop (arg1))
4969 return omit_one_operand (type, arg1, arg0);
4970 /* In IEEE floating point, x*1 is not equivalent to x for snans.
4971 However, ANSI says we can drop signals,
4972 so we can do this anyway. */
4973 if (real_onep (arg1))
4974 return non_lvalue (convert (type, arg0));
4976 if (! wins && real_twop (arg1) && current_function_decl != 0
4977 && ! contains_placeholder_p (arg0))
4979 tree arg = save_expr (arg0);
4980 return build (PLUS_EXPR, type, arg, arg);
4988 register enum tree_code code0, code1;
4990 if (integer_all_onesp (arg1))
4991 return omit_one_operand (type, arg1, arg0);
4992 if (integer_zerop (arg1))
4993 return non_lvalue (convert (type, arg0));
4994 t1 = distribute_bit_expr (code, type, arg0, arg1);
4995 if (t1 != NULL_TREE)
4998 /* (A << C1) | (A >> C2) if A is unsigned and C1+C2 is the size of A
4999 is a rotate of A by C1 bits. */
5000 /* (A << B) | (A >> (Z - B)) if A is unsigned and Z is the size of A
5001 is a rotate of A by B bits. */
5003 code0 = TREE_CODE (arg0);
5004 code1 = TREE_CODE (arg1);
5005 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5006 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5007 && operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1,0), 0)
5008 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5010 register tree tree01, tree11;
5011 register enum tree_code code01, code11;
5013 tree01 = TREE_OPERAND (arg0, 1);
5014 tree11 = TREE_OPERAND (arg1, 1);
5015 STRIP_NOPS (tree01);
5016 STRIP_NOPS (tree11);
5017 code01 = TREE_CODE (tree01);
5018 code11 = TREE_CODE (tree11);
5019 if (code01 == INTEGER_CST
5020 && code11 == INTEGER_CST
5021 && TREE_INT_CST_HIGH (tree01) == 0
5022 && TREE_INT_CST_HIGH (tree11) == 0
5023 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5024 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5025 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5026 code0 == LSHIFT_EXPR ? tree01 : tree11);
5027 else if (code11 == MINUS_EXPR)
5029 tree tree110, tree111;
5030 tree110 = TREE_OPERAND (tree11, 0);
5031 tree111 = TREE_OPERAND (tree11, 1);
5032 STRIP_NOPS (tree110);
5033 STRIP_NOPS (tree111);
5034 if (TREE_CODE (tree110) == INTEGER_CST
5035 && TREE_INT_CST_HIGH (tree110) == 0
5036 && (TREE_INT_CST_LOW (tree110)
5037 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5038 && operand_equal_p (tree01, tree111, 0))
5039 return build ((code0 == LSHIFT_EXPR
5042 type, TREE_OPERAND (arg0, 0), tree01);
5044 else if (code01 == MINUS_EXPR)
5046 tree tree010, tree011;
5047 tree010 = TREE_OPERAND (tree01, 0);
5048 tree011 = TREE_OPERAND (tree01, 1);
5049 STRIP_NOPS (tree010);
5050 STRIP_NOPS (tree011);
5051 if (TREE_CODE (tree010) == INTEGER_CST
5052 && TREE_INT_CST_HIGH (tree010) == 0
5053 && (TREE_INT_CST_LOW (tree010)
5054 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5055 && operand_equal_p (tree11, tree011, 0))
5056 return build ((code0 != LSHIFT_EXPR
5059 type, TREE_OPERAND (arg0, 0), tree11);
5067 if (integer_zerop (arg1))
5068 return non_lvalue (convert (type, arg0));
5069 if (integer_all_onesp (arg1))
5070 return fold (build1 (BIT_NOT_EXPR, type, arg0));
5075 if (integer_all_onesp (arg1))
5076 return non_lvalue (convert (type, arg0));
5077 if (integer_zerop (arg1))
5078 return omit_one_operand (type, arg1, arg0);
5079 t1 = distribute_bit_expr (code, type, arg0, arg1);
5080 if (t1 != NULL_TREE)
5082 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5083 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == NOP_EXPR
5084 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0))))
5086 int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0)));
5087 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5088 && (~TREE_INT_CST_LOW (arg0)
5089 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5090 return build1 (NOP_EXPR, type, TREE_OPERAND (arg1, 0));
5092 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
5093 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5095 int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
5096 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5097 && (~TREE_INT_CST_LOW (arg1)
5098 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5099 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
5103 case BIT_ANDTC_EXPR:
5104 if (integer_all_onesp (arg0))
5105 return non_lvalue (convert (type, arg1));
5106 if (integer_zerop (arg0))
5107 return omit_one_operand (type, arg0, arg1);
5108 if (TREE_CODE (arg1) == INTEGER_CST)
5110 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
5111 code = BIT_AND_EXPR;
5117 /* In most cases, do nothing with a divide by zero. */
5118 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5119 #ifndef REAL_INFINITY
5120 if (TREE_CODE (arg1) == REAL_CST && real_zerop (arg1))
5123 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5125 /* In IEEE floating point, x/1 is not equivalent to x for snans.
5126 However, ANSI says we can drop signals, so we can do this anyway. */
5127 if (real_onep (arg1))
5128 return non_lvalue (convert (type, arg0));
5130 /* If ARG1 is a constant, we can convert this to a multiply by the
5131 reciprocal. This does not have the same rounding properties,
5132 so only do this if -ffast-math. We can actually always safely
5133 do it if ARG1 is a power of two, but it's hard to tell if it is
5134 or not in a portable manner. */
5135 if (TREE_CODE (arg1) == REAL_CST)
5138 && 0 != (tem = const_binop (code, build_real (type, dconst1),
5140 return fold (build (MULT_EXPR, type, arg0, tem));
5141 /* Find the reciprocal if optimizing and the result is exact. */
5145 r = TREE_REAL_CST (arg1);
5146 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
5148 tem = build_real (type, r);
5149 return fold (build (MULT_EXPR, type, arg0, tem));
5155 case TRUNC_DIV_EXPR:
5156 case ROUND_DIV_EXPR:
5157 case FLOOR_DIV_EXPR:
5159 case EXACT_DIV_EXPR:
5160 if (integer_onep (arg1))
5161 return non_lvalue (convert (type, arg0));
5162 if (integer_zerop (arg1))
5165 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
5166 operation, EXACT_DIV_EXPR.
5168 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
5169 At one time others generated faster code, it's not clear if they do
5170 after the last round to changes to the DIV code in expmed.c. */
5171 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
5172 && multiple_of_p (type, arg0, arg1))
5173 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
5175 /* If we have ((a / C1) / C2) where both division are the same type, try
5176 to simplify. First see if C1 * C2 overflows or not. */
5177 if (TREE_CODE (arg0) == code && TREE_CODE (arg1) == INTEGER_CST
5178 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5182 new_divisor = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 1), arg1, 0);
5183 tem = const_binop (FLOOR_DIV_EXPR, new_divisor, arg1, 0);
5185 if (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) == TREE_INT_CST_LOW (tem)
5186 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == TREE_INT_CST_HIGH (tem))
5188 /* If no overflow, divide by C1*C2. */
5189 return fold (build (code, type, TREE_OPERAND (arg0, 0), new_divisor));
5193 /* Look for ((a * C1) / C3) or (((a * C1) + C2) / C3),
5194 where C1 % C3 == 0 or C3 % C1 == 0. We can simplify these
5195 expressions, which often appear in the offsets or sizes of
5196 objects with a varying size. Only deal with positive divisors
5197 and multiplicands. If C2 is negative, we must have C2 % C3 == 0.
5199 Look for NOPs and SAVE_EXPRs inside. */
5201 if (TREE_CODE (arg1) == INTEGER_CST
5202 && tree_int_cst_sgn (arg1) >= 0)
5204 int have_save_expr = 0;
5205 tree c2 = integer_zero_node;
5208 if (TREE_CODE (xarg0) == SAVE_EXPR && SAVE_EXPR_RTL (xarg0) == 0)
5209 have_save_expr = 1, xarg0 = TREE_OPERAND (xarg0, 0);
5213 /* Look inside the dividend and simplify using EXACT_DIV_EXPR
5215 if (TREE_CODE (xarg0) == MULT_EXPR
5216 && multiple_of_p (type, TREE_OPERAND (xarg0, 0), arg1))
5220 t = fold (build (MULT_EXPR, type,
5221 fold (build (EXACT_DIV_EXPR, type,
5222 TREE_OPERAND (xarg0, 0), arg1)),
5223 TREE_OPERAND (xarg0, 1)));
5230 if (TREE_CODE (xarg0) == MULT_EXPR
5231 && multiple_of_p (type, TREE_OPERAND (xarg0, 1), arg1))
5235 t = fold (build (MULT_EXPR, type,
5236 fold (build (EXACT_DIV_EXPR, type,
5237 TREE_OPERAND (xarg0, 1), arg1)),
5238 TREE_OPERAND (xarg0, 0)));
5244 if (TREE_CODE (xarg0) == PLUS_EXPR
5245 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST)
5246 c2 = TREE_OPERAND (xarg0, 1), xarg0 = TREE_OPERAND (xarg0, 0);
5247 else if (TREE_CODE (xarg0) == MINUS_EXPR
5248 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5249 /* If we are doing this computation unsigned, the negate
5251 && ! TREE_UNSIGNED (type))
5253 c2 = fold (build1 (NEGATE_EXPR, type, TREE_OPERAND (xarg0, 1)));
5254 xarg0 = TREE_OPERAND (xarg0, 0);
5257 if (TREE_CODE (xarg0) == SAVE_EXPR && SAVE_EXPR_RTL (xarg0) == 0)
5258 have_save_expr = 1, xarg0 = TREE_OPERAND (xarg0, 0);
5262 if (TREE_CODE (xarg0) == MULT_EXPR
5263 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5264 && tree_int_cst_sgn (TREE_OPERAND (xarg0, 1)) >= 0
5265 && (integer_zerop (const_binop (TRUNC_MOD_EXPR,
5266 TREE_OPERAND (xarg0, 1), arg1, 1))
5267 || integer_zerop (const_binop (TRUNC_MOD_EXPR, arg1,
5268 TREE_OPERAND (xarg0, 1), 1)))
5269 && (tree_int_cst_sgn (c2) >= 0
5270 || integer_zerop (const_binop (TRUNC_MOD_EXPR, c2,
5273 tree outer_div = integer_one_node;
5274 tree c1 = TREE_OPERAND (xarg0, 1);
5277 /* If C3 > C1, set them equal and do a divide by
5278 C3/C1 at the end of the operation. */
5279 if (tree_int_cst_lt (c1, c3))
5280 outer_div = const_binop (code, c3, c1, 0), c3 = c1;
5282 /* The result is A * (C1/C3) + (C2/C3). */
5283 t = fold (build (PLUS_EXPR, type,
5284 fold (build (MULT_EXPR, type,
5285 TREE_OPERAND (xarg0, 0),
5286 const_binop (code, c1, c3, 1))),
5287 const_binop (code, c2, c3, 1)));
5289 if (! integer_onep (outer_div))
5290 t = fold (build (code, type, t, convert (type, outer_div)));
5302 case FLOOR_MOD_EXPR:
5303 case ROUND_MOD_EXPR:
5304 case TRUNC_MOD_EXPR:
5305 if (integer_onep (arg1))
5306 return omit_one_operand (type, integer_zero_node, arg0);
5307 if (integer_zerop (arg1))
5310 /* Look for ((a * C1) % C3) or (((a * C1) + C2) % C3),
5311 where C1 % C3 == 0. Handle similarly to the division case,
5312 but don't bother with SAVE_EXPRs. */
5314 if (TREE_CODE (arg1) == INTEGER_CST
5315 && ! integer_zerop (arg1))
5317 tree c2 = integer_zero_node;
5320 if (TREE_CODE (xarg0) == PLUS_EXPR
5321 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST)
5322 c2 = TREE_OPERAND (xarg0, 1), xarg0 = TREE_OPERAND (xarg0, 0);
5323 else if (TREE_CODE (xarg0) == MINUS_EXPR
5324 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5325 && ! TREE_UNSIGNED (type))
5327 c2 = fold (build1 (NEGATE_EXPR, type, TREE_OPERAND (xarg0, 1)));
5328 xarg0 = TREE_OPERAND (xarg0, 0);
5333 if (TREE_CODE (xarg0) == MULT_EXPR
5334 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5335 && integer_zerop (const_binop (TRUNC_MOD_EXPR,
5336 TREE_OPERAND (xarg0, 1),
5338 && tree_int_cst_sgn (c2) >= 0)
5339 /* The result is (C2%C3). */
5340 return omit_one_operand (type, const_binop (code, c2, arg1, 1),
5341 TREE_OPERAND (xarg0, 0));
5350 if (integer_zerop (arg1))
5351 return non_lvalue (convert (type, arg0));
5352 /* Since negative shift count is not well-defined,
5353 don't try to compute it in the compiler. */
5354 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
5356 /* Rewrite an LROTATE_EXPR by a constant into an
5357 RROTATE_EXPR by a new constant. */
5358 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
5360 TREE_SET_CODE (t, RROTATE_EXPR);
5361 code = RROTATE_EXPR;
5362 TREE_OPERAND (t, 1) = arg1
5365 convert (TREE_TYPE (arg1),
5366 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
5368 if (tree_int_cst_sgn (arg1) < 0)
5372 /* If we have a rotate of a bit operation with the rotate count and
5373 the second operand of the bit operation both constant,
5374 permute the two operations. */
5375 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5376 && (TREE_CODE (arg0) == BIT_AND_EXPR
5377 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
5378 || TREE_CODE (arg0) == BIT_IOR_EXPR
5379 || TREE_CODE (arg0) == BIT_XOR_EXPR)
5380 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5381 return fold (build (TREE_CODE (arg0), type,
5382 fold (build (code, type,
5383 TREE_OPERAND (arg0, 0), arg1)),
5384 fold (build (code, type,
5385 TREE_OPERAND (arg0, 1), arg1))));
5387 /* Two consecutive rotates adding up to the width of the mode can
5389 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5390 && TREE_CODE (arg0) == RROTATE_EXPR
5391 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5392 && TREE_INT_CST_HIGH (arg1) == 0
5393 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
5394 && ((TREE_INT_CST_LOW (arg1)
5395 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
5396 == GET_MODE_BITSIZE (TYPE_MODE (type))))
5397 return TREE_OPERAND (arg0, 0);
5402 if (operand_equal_p (arg0, arg1, 0))
5404 if (INTEGRAL_TYPE_P (type)
5405 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
5406 return omit_one_operand (type, arg1, arg0);
5410 if (operand_equal_p (arg0, arg1, 0))
5412 if (INTEGRAL_TYPE_P (type)
5413 && TYPE_MAX_VALUE (type)
5414 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
5415 return omit_one_operand (type, arg1, arg0);
5418 case TRUTH_NOT_EXPR:
5419 /* Note that the operand of this must be an int
5420 and its values must be 0 or 1.
5421 ("true" is a fixed value perhaps depending on the language,
5422 but we don't handle values other than 1 correctly yet.) */
5423 tem = invert_truthvalue (arg0);
5424 /* Avoid infinite recursion. */
5425 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
5427 return convert (type, tem);
5429 case TRUTH_ANDIF_EXPR:
5430 /* Note that the operands of this must be ints
5431 and their values must be 0 or 1.
5432 ("true" is a fixed value perhaps depending on the language.) */
5433 /* If first arg is constant zero, return it. */
5434 if (integer_zerop (arg0))
5436 case TRUTH_AND_EXPR:
5437 /* If either arg is constant true, drop it. */
5438 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5439 return non_lvalue (arg1);
5440 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5441 return non_lvalue (arg0);
5442 /* If second arg is constant zero, result is zero, but first arg
5443 must be evaluated. */
5444 if (integer_zerop (arg1))
5445 return omit_one_operand (type, arg1, arg0);
5446 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
5447 case will be handled here. */
5448 if (integer_zerop (arg0))
5449 return omit_one_operand (type, arg0, arg1);
5452 /* We only do these simplifications if we are optimizing. */
5456 /* Check for things like (A || B) && (A || C). We can convert this
5457 to A || (B && C). Note that either operator can be any of the four
5458 truth and/or operations and the transformation will still be
5459 valid. Also note that we only care about order for the
5460 ANDIF and ORIF operators. If B contains side effects, this
5461 might change the truth-value of A. */
5462 if (TREE_CODE (arg0) == TREE_CODE (arg1)
5463 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
5464 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
5465 || TREE_CODE (arg0) == TRUTH_AND_EXPR
5466 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
5467 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
5469 tree a00 = TREE_OPERAND (arg0, 0);
5470 tree a01 = TREE_OPERAND (arg0, 1);
5471 tree a10 = TREE_OPERAND (arg1, 0);
5472 tree a11 = TREE_OPERAND (arg1, 1);
5473 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
5474 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
5475 && (code == TRUTH_AND_EXPR
5476 || code == TRUTH_OR_EXPR));
5478 if (operand_equal_p (a00, a10, 0))
5479 return fold (build (TREE_CODE (arg0), type, a00,
5480 fold (build (code, type, a01, a11))));
5481 else if (commutative && operand_equal_p (a00, a11, 0))
5482 return fold (build (TREE_CODE (arg0), type, a00,
5483 fold (build (code, type, a01, a10))));
5484 else if (commutative && operand_equal_p (a01, a10, 0))
5485 return fold (build (TREE_CODE (arg0), type, a01,
5486 fold (build (code, type, a00, a11))));
5488 /* This case if tricky because we must either have commutative
5489 operators or else A10 must not have side-effects. */
5491 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
5492 && operand_equal_p (a01, a11, 0))
5493 return fold (build (TREE_CODE (arg0), type,
5494 fold (build (code, type, a00, a10)),
5498 /* See if we can build a range comparison. */
5499 if (0 != (tem = fold_range_test (t)))
5502 /* Check for the possibility of merging component references. If our
5503 lhs is another similar operation, try to merge its rhs with our
5504 rhs. Then try to merge our lhs and rhs. */
5505 if (TREE_CODE (arg0) == code
5506 && 0 != (tem = fold_truthop (code, type,
5507 TREE_OPERAND (arg0, 1), arg1)))
5508 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
5510 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
5515 case TRUTH_ORIF_EXPR:
5516 /* Note that the operands of this must be ints
5517 and their values must be 0 or true.
5518 ("true" is a fixed value perhaps depending on the language.) */
5519 /* If first arg is constant true, return it. */
5520 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5523 /* If either arg is constant zero, drop it. */
5524 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
5525 return non_lvalue (arg1);
5526 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1))
5527 return non_lvalue (arg0);
5528 /* If second arg is constant true, result is true, but we must
5529 evaluate first arg. */
5530 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5531 return omit_one_operand (type, arg1, arg0);
5532 /* Likewise for first arg, but note this only occurs here for
5534 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5535 return omit_one_operand (type, arg0, arg1);
5538 case TRUTH_XOR_EXPR:
5539 /* If either arg is constant zero, drop it. */
5540 if (integer_zerop (arg0))
5541 return non_lvalue (arg1);
5542 if (integer_zerop (arg1))
5543 return non_lvalue (arg0);
5544 /* If either arg is constant true, this is a logical inversion. */
5545 if (integer_onep (arg0))
5546 return non_lvalue (invert_truthvalue (arg1));
5547 if (integer_onep (arg1))
5548 return non_lvalue (invert_truthvalue (arg0));
5557 /* If one arg is a constant integer, put it last. */
5558 if (TREE_CODE (arg0) == INTEGER_CST
5559 && TREE_CODE (arg1) != INTEGER_CST)
5561 TREE_OPERAND (t, 0) = arg1;
5562 TREE_OPERAND (t, 1) = arg0;
5563 arg0 = TREE_OPERAND (t, 0);
5564 arg1 = TREE_OPERAND (t, 1);
5565 code = swap_tree_comparison (code);
5566 TREE_SET_CODE (t, code);
5569 /* Convert foo++ == CONST into ++foo == CONST + INCR.
5570 First, see if one arg is constant; find the constant arg
5571 and the other one. */
5573 tree constop = 0, varop = NULL_TREE;
5574 int constopnum = -1;
5576 if (TREE_CONSTANT (arg1))
5577 constopnum = 1, constop = arg1, varop = arg0;
5578 if (TREE_CONSTANT (arg0))
5579 constopnum = 0, constop = arg0, varop = arg1;
5581 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
5583 /* This optimization is invalid for ordered comparisons
5584 if CONST+INCR overflows or if foo+incr might overflow.
5585 This optimization is invalid for floating point due to rounding.
5586 For pointer types we assume overflow doesn't happen. */
5587 if (POINTER_TYPE_P (TREE_TYPE (varop))
5588 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
5589 && (code == EQ_EXPR || code == NE_EXPR)))
5592 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
5593 constop, TREE_OPERAND (varop, 1)));
5594 TREE_SET_CODE (varop, PREINCREMENT_EXPR);
5596 /* If VAROP is a reference to a bitfield, we must mask
5597 the constant by the width of the field. */
5598 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
5599 && DECL_BIT_FIELD(TREE_OPERAND
5600 (TREE_OPERAND (varop, 0), 1)))
5603 = TREE_INT_CST_LOW (DECL_SIZE
5605 (TREE_OPERAND (varop, 0), 1)));
5606 tree mask, unsigned_type;
5608 tree folded_compare;
5610 /* First check whether the comparison would come out
5611 always the same. If we don't do that we would
5612 change the meaning with the masking. */
5613 if (constopnum == 0)
5614 folded_compare = fold (build (code, type, constop,
5615 TREE_OPERAND (varop, 0)));
5617 folded_compare = fold (build (code, type,
5618 TREE_OPERAND (varop, 0),
5620 if (integer_zerop (folded_compare)
5621 || integer_onep (folded_compare))
5622 return omit_one_operand (type, folded_compare, varop);
5624 unsigned_type = type_for_size (size, 1);
5625 precision = TYPE_PRECISION (unsigned_type);
5626 mask = build_int_2 (~0, ~0);
5627 TREE_TYPE (mask) = unsigned_type;
5628 force_fit_type (mask, 0);
5629 mask = const_binop (RSHIFT_EXPR, mask,
5630 size_int (precision - size), 0);
5631 newconst = fold (build (BIT_AND_EXPR,
5632 TREE_TYPE (varop), newconst,
5633 convert (TREE_TYPE (varop),
5638 t = build (code, type, TREE_OPERAND (t, 0),
5639 TREE_OPERAND (t, 1));
5640 TREE_OPERAND (t, constopnum) = newconst;
5644 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
5646 if (POINTER_TYPE_P (TREE_TYPE (varop))
5647 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
5648 && (code == EQ_EXPR || code == NE_EXPR)))
5651 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
5652 constop, TREE_OPERAND (varop, 1)));
5653 TREE_SET_CODE (varop, PREDECREMENT_EXPR);
5655 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
5656 && DECL_BIT_FIELD(TREE_OPERAND
5657 (TREE_OPERAND (varop, 0), 1)))
5660 = TREE_INT_CST_LOW (DECL_SIZE
5662 (TREE_OPERAND (varop, 0), 1)));
5663 tree mask, unsigned_type;
5665 tree folded_compare;
5667 if (constopnum == 0)
5668 folded_compare = fold (build (code, type, constop,
5669 TREE_OPERAND (varop, 0)));
5671 folded_compare = fold (build (code, type,
5672 TREE_OPERAND (varop, 0),
5674 if (integer_zerop (folded_compare)
5675 || integer_onep (folded_compare))
5676 return omit_one_operand (type, folded_compare, varop);
5678 unsigned_type = type_for_size (size, 1);
5679 precision = TYPE_PRECISION (unsigned_type);
5680 mask = build_int_2 (~0, ~0);
5681 TREE_TYPE (mask) = TREE_TYPE (varop);
5682 force_fit_type (mask, 0);
5683 mask = const_binop (RSHIFT_EXPR, mask,
5684 size_int (precision - size), 0);
5685 newconst = fold (build (BIT_AND_EXPR,
5686 TREE_TYPE (varop), newconst,
5687 convert (TREE_TYPE (varop),
5692 t = build (code, type, TREE_OPERAND (t, 0),
5693 TREE_OPERAND (t, 1));
5694 TREE_OPERAND (t, constopnum) = newconst;
5700 /* Change X >= CST to X > (CST - 1) if CST is positive. */
5701 if (TREE_CODE (arg1) == INTEGER_CST
5702 && TREE_CODE (arg0) != INTEGER_CST
5703 && tree_int_cst_sgn (arg1) > 0)
5705 switch (TREE_CODE (t))
5709 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
5710 t = build (code, type, TREE_OPERAND (t, 0), arg1);
5715 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
5716 t = build (code, type, TREE_OPERAND (t, 0), arg1);
5724 /* If this is an EQ or NE comparison with zero and ARG0 is
5725 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
5726 two operations, but the latter can be done in one less insn
5727 on machines that have only two-operand insns or on which a
5728 constant cannot be the first operand. */
5729 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
5730 && TREE_CODE (arg0) == BIT_AND_EXPR)
5732 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
5733 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
5735 fold (build (code, type,
5736 build (BIT_AND_EXPR, TREE_TYPE (arg0),
5738 TREE_TYPE (TREE_OPERAND (arg0, 0)),
5739 TREE_OPERAND (arg0, 1),
5740 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
5741 convert (TREE_TYPE (arg0),
5744 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
5745 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
5747 fold (build (code, type,
5748 build (BIT_AND_EXPR, TREE_TYPE (arg0),
5750 TREE_TYPE (TREE_OPERAND (arg0, 1)),
5751 TREE_OPERAND (arg0, 0),
5752 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
5753 convert (TREE_TYPE (arg0),
5758 /* If this is an NE or EQ comparison of zero against the result of a
5759 signed MOD operation whose second operand is a power of 2, make
5760 the MOD operation unsigned since it is simpler and equivalent. */
5761 if ((code == NE_EXPR || code == EQ_EXPR)
5762 && integer_zerop (arg1)
5763 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
5764 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
5765 || TREE_CODE (arg0) == CEIL_MOD_EXPR
5766 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
5767 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
5768 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5770 tree newtype = unsigned_type (TREE_TYPE (arg0));
5771 tree newmod = build (TREE_CODE (arg0), newtype,
5772 convert (newtype, TREE_OPERAND (arg0, 0)),
5773 convert (newtype, TREE_OPERAND (arg0, 1)));
5775 return build (code, type, newmod, convert (newtype, arg1));
5778 /* If this is an NE comparison of zero with an AND of one, remove the
5779 comparison since the AND will give the correct value. */
5780 if (code == NE_EXPR && integer_zerop (arg1)
5781 && TREE_CODE (arg0) == BIT_AND_EXPR
5782 && integer_onep (TREE_OPERAND (arg0, 1)))
5783 return convert (type, arg0);
5785 /* If we have (A & C) == C where C is a power of 2, convert this into
5786 (A & C) != 0. Similarly for NE_EXPR. */
5787 if ((code == EQ_EXPR || code == NE_EXPR)
5788 && TREE_CODE (arg0) == BIT_AND_EXPR
5789 && integer_pow2p (TREE_OPERAND (arg0, 1))
5790 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
5791 return build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
5792 arg0, integer_zero_node);
5794 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
5795 and similarly for >= into !=. */
5796 if ((code == LT_EXPR || code == GE_EXPR)
5797 && TREE_UNSIGNED (TREE_TYPE (arg0))
5798 && TREE_CODE (arg1) == LSHIFT_EXPR
5799 && integer_onep (TREE_OPERAND (arg1, 0)))
5800 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
5801 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
5802 TREE_OPERAND (arg1, 1)),
5803 convert (TREE_TYPE (arg0), integer_zero_node));
5805 else if ((code == LT_EXPR || code == GE_EXPR)
5806 && TREE_UNSIGNED (TREE_TYPE (arg0))
5807 && (TREE_CODE (arg1) == NOP_EXPR
5808 || TREE_CODE (arg1) == CONVERT_EXPR)
5809 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
5810 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
5812 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
5813 convert (TREE_TYPE (arg0),
5814 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
5815 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
5816 convert (TREE_TYPE (arg0), integer_zero_node));
5818 /* Simplify comparison of something with itself. (For IEEE
5819 floating-point, we can only do some of these simplifications.) */
5820 if (operand_equal_p (arg0, arg1, 0))
5827 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
5828 return constant_boolean_node (1, type);
5830 TREE_SET_CODE (t, code);
5834 /* For NE, we can only do this simplification if integer. */
5835 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
5837 /* ... fall through ... */
5840 return constant_boolean_node (0, type);
5846 /* An unsigned comparison against 0 can be simplified. */
5847 if (integer_zerop (arg1)
5848 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
5849 || POINTER_TYPE_P (TREE_TYPE (arg1)))
5850 && TREE_UNSIGNED (TREE_TYPE (arg1)))
5852 switch (TREE_CODE (t))
5856 TREE_SET_CODE (t, NE_EXPR);
5860 TREE_SET_CODE (t, EQ_EXPR);
5863 return omit_one_operand (type,
5864 convert (type, integer_one_node),
5867 return omit_one_operand (type,
5868 convert (type, integer_zero_node),
5875 /* An unsigned <= 0x7fffffff can be simplified. */
5877 int width = TYPE_PRECISION (TREE_TYPE (arg1));
5878 if (TREE_CODE (arg1) == INTEGER_CST
5879 && ! TREE_CONSTANT_OVERFLOW (arg1)
5880 && width <= HOST_BITS_PER_WIDE_INT
5881 && TREE_INT_CST_LOW (arg1) == ((HOST_WIDE_INT) 1 << (width - 1)) - 1
5882 && TREE_INT_CST_HIGH (arg1) == 0
5883 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
5884 || POINTER_TYPE_P (TREE_TYPE (arg1)))
5885 && TREE_UNSIGNED (TREE_TYPE (arg1)))
5887 switch (TREE_CODE (t))
5890 return fold (build (GE_EXPR, type,
5891 convert (signed_type (TREE_TYPE (arg0)),
5893 convert (signed_type (TREE_TYPE (arg1)),
5894 integer_zero_node)));
5896 return fold (build (LT_EXPR, type,
5897 convert (signed_type (TREE_TYPE (arg0)),
5899 convert (signed_type (TREE_TYPE (arg1)),
5900 integer_zero_node)));
5907 /* If we are comparing an expression that just has comparisons
5908 of two integer values, arithmetic expressions of those comparisons,
5909 and constants, we can simplify it. There are only three cases
5910 to check: the two values can either be equal, the first can be
5911 greater, or the second can be greater. Fold the expression for
5912 those three values. Since each value must be 0 or 1, we have
5913 eight possibilities, each of which corresponds to the constant 0
5914 or 1 or one of the six possible comparisons.
5916 This handles common cases like (a > b) == 0 but also handles
5917 expressions like ((x > y) - (y > x)) > 0, which supposedly
5918 occur in macroized code. */
5920 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
5922 tree cval1 = 0, cval2 = 0;
5925 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
5926 /* Don't handle degenerate cases here; they should already
5927 have been handled anyway. */
5928 && cval1 != 0 && cval2 != 0
5929 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
5930 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
5931 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
5932 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
5933 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
5934 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
5935 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
5937 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
5938 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
5940 /* We can't just pass T to eval_subst in case cval1 or cval2
5941 was the same as ARG1. */
5944 = fold (build (code, type,
5945 eval_subst (arg0, cval1, maxval, cval2, minval),
5948 = fold (build (code, type,
5949 eval_subst (arg0, cval1, maxval, cval2, maxval),
5952 = fold (build (code, type,
5953 eval_subst (arg0, cval1, minval, cval2, maxval),
5956 /* All three of these results should be 0 or 1. Confirm they
5957 are. Then use those values to select the proper code
5960 if ((integer_zerop (high_result)
5961 || integer_onep (high_result))
5962 && (integer_zerop (equal_result)
5963 || integer_onep (equal_result))
5964 && (integer_zerop (low_result)
5965 || integer_onep (low_result)))
5967 /* Make a 3-bit mask with the high-order bit being the
5968 value for `>', the next for '=', and the low for '<'. */
5969 switch ((integer_onep (high_result) * 4)
5970 + (integer_onep (equal_result) * 2)
5971 + integer_onep (low_result))
5975 return omit_one_operand (type, integer_zero_node, arg0);
5996 return omit_one_operand (type, integer_one_node, arg0);
5999 t = build (code, type, cval1, cval2);
6001 return save_expr (t);
6008 /* If this is a comparison of a field, we may be able to simplify it. */
6009 if ((TREE_CODE (arg0) == COMPONENT_REF
6010 || TREE_CODE (arg0) == BIT_FIELD_REF)
6011 && (code == EQ_EXPR || code == NE_EXPR)
6012 /* Handle the constant case even without -O
6013 to make sure the warnings are given. */
6014 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
6016 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
6020 /* If this is a comparison of complex values and either or both sides
6021 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6022 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6023 This may prevent needless evaluations. */
6024 if ((code == EQ_EXPR || code == NE_EXPR)
6025 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
6026 && (TREE_CODE (arg0) == COMPLEX_EXPR
6027 || TREE_CODE (arg1) == COMPLEX_EXPR
6028 || TREE_CODE (arg0) == COMPLEX_CST
6029 || TREE_CODE (arg1) == COMPLEX_CST))
6031 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
6032 tree real0, imag0, real1, imag1;
6034 arg0 = save_expr (arg0);
6035 arg1 = save_expr (arg1);
6036 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
6037 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
6038 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
6039 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
6041 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
6044 fold (build (code, type, real0, real1)),
6045 fold (build (code, type, imag0, imag1))));
6048 /* From here on, the only cases we handle are when the result is
6049 known to be a constant.
6051 To compute GT, swap the arguments and do LT.
6052 To compute GE, do LT and invert the result.
6053 To compute LE, swap the arguments, do LT and invert the result.
6054 To compute NE, do EQ and invert the result.
6056 Therefore, the code below must handle only EQ and LT. */
6058 if (code == LE_EXPR || code == GT_EXPR)
6060 tem = arg0, arg0 = arg1, arg1 = tem;
6061 code = swap_tree_comparison (code);
6064 /* Note that it is safe to invert for real values here because we
6065 will check below in the one case that it matters. */
6068 if (code == NE_EXPR || code == GE_EXPR)
6071 code = invert_tree_comparison (code);
6074 /* Compute a result for LT or EQ if args permit;
6075 otherwise return T. */
6076 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
6078 if (code == EQ_EXPR)
6079 t1 = build_int_2 ((TREE_INT_CST_LOW (arg0)
6080 == TREE_INT_CST_LOW (arg1))
6081 && (TREE_INT_CST_HIGH (arg0)
6082 == TREE_INT_CST_HIGH (arg1)),
6085 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
6086 ? INT_CST_LT_UNSIGNED (arg0, arg1)
6087 : INT_CST_LT (arg0, arg1)),
6091 #if 0 /* This is no longer useful, but breaks some real code. */
6092 /* Assume a nonexplicit constant cannot equal an explicit one,
6093 since such code would be undefined anyway.
6094 Exception: on sysvr4, using #pragma weak,
6095 a label can come out as 0. */
6096 else if (TREE_CODE (arg1) == INTEGER_CST
6097 && !integer_zerop (arg1)
6098 && TREE_CONSTANT (arg0)
6099 && TREE_CODE (arg0) == ADDR_EXPR
6101 t1 = build_int_2 (0, 0);
6103 /* Two real constants can be compared explicitly. */
6104 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
6106 /* If either operand is a NaN, the result is false with two
6107 exceptions: First, an NE_EXPR is true on NaNs, but that case
6108 is already handled correctly since we will be inverting the
6109 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6110 or a GE_EXPR into a LT_EXPR, we must return true so that it
6111 will be inverted into false. */
6113 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
6114 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
6115 t1 = build_int_2 (invert && code == LT_EXPR, 0);
6117 else if (code == EQ_EXPR)
6118 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
6119 TREE_REAL_CST (arg1)),
6122 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
6123 TREE_REAL_CST (arg1)),
6127 if (t1 == NULL_TREE)
6131 TREE_INT_CST_LOW (t1) ^= 1;
6133 TREE_TYPE (t1) = type;
6134 if (TREE_CODE (type) == BOOLEAN_TYPE)
6135 return truthvalue_conversion (t1);
6139 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
6140 so all simple results must be passed through pedantic_non_lvalue. */
6141 if (TREE_CODE (arg0) == INTEGER_CST)
6142 return pedantic_non_lvalue
6143 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
6144 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
6145 return pedantic_omit_one_operand (type, arg1, arg0);
6147 /* If the second operand is zero, invert the comparison and swap
6148 the second and third operands. Likewise if the second operand
6149 is constant and the third is not or if the third operand is
6150 equivalent to the first operand of the comparison. */
6152 if (integer_zerop (arg1)
6153 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
6154 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6155 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6156 TREE_OPERAND (t, 2),
6157 TREE_OPERAND (arg0, 1))))
6159 /* See if this can be inverted. If it can't, possibly because
6160 it was a floating-point inequality comparison, don't do
6162 tem = invert_truthvalue (arg0);
6164 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6166 t = build (code, type, tem,
6167 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6169 /* arg1 should be the first argument of the new T. */
6170 arg1 = TREE_OPERAND (t, 1);
6175 /* If we have A op B ? A : C, we may be able to convert this to a
6176 simpler expression, depending on the operation and the values
6177 of B and C. IEEE floating point prevents this though,
6178 because A or B might be -0.0 or a NaN. */
6180 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6181 && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
6182 || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0)))
6184 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6185 arg1, TREE_OPERAND (arg0, 1)))
6187 tree arg2 = TREE_OPERAND (t, 2);
6188 enum tree_code comp_code = TREE_CODE (arg0);
6192 /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
6193 depending on the comparison operation. */
6194 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
6195 ? real_zerop (TREE_OPERAND (arg0, 1))
6196 : integer_zerop (TREE_OPERAND (arg0, 1)))
6197 && TREE_CODE (arg2) == NEGATE_EXPR
6198 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
6202 return pedantic_non_lvalue
6203 (fold (build1 (NEGATE_EXPR, type, arg1)));
6205 return pedantic_non_lvalue (convert (type, arg1));
6208 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6209 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6210 return pedantic_non_lvalue
6211 (convert (type, fold (build1 (ABS_EXPR,
6212 TREE_TYPE (arg1), arg1))));
6215 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6216 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6217 return pedantic_non_lvalue
6218 (fold (build1 (NEGATE_EXPR, type,
6220 fold (build1 (ABS_EXPR,
6227 /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
6230 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
6232 if (comp_code == NE_EXPR)
6233 return pedantic_non_lvalue (convert (type, arg1));
6234 else if (comp_code == EQ_EXPR)
6235 return pedantic_non_lvalue (convert (type, integer_zero_node));
6238 /* If this is A op B ? A : B, this is either A, B, min (A, B),
6239 or max (A, B), depending on the operation. */
6241 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
6242 arg2, TREE_OPERAND (arg0, 0)))
6244 tree comp_op0 = TREE_OPERAND (arg0, 0);
6245 tree comp_op1 = TREE_OPERAND (arg0, 1);
6246 tree comp_type = TREE_TYPE (comp_op0);
6251 return pedantic_non_lvalue (convert (type, arg2));
6253 return pedantic_non_lvalue (convert (type, arg1));
6256 /* In C++ a ?: expression can be an lvalue, so put the
6257 operand which will be used if they are equal first
6258 so that we can convert this back to the
6259 corresponding COND_EXPR. */
6260 return pedantic_non_lvalue
6261 (convert (type, (fold (build (MIN_EXPR, comp_type,
6262 (comp_code == LE_EXPR
6263 ? comp_op0 : comp_op1),
6264 (comp_code == LE_EXPR
6265 ? comp_op1 : comp_op0))))));
6269 return pedantic_non_lvalue
6270 (convert (type, fold (build (MAX_EXPR, comp_type,
6271 (comp_code == GE_EXPR
6272 ? comp_op0 : comp_op1),
6273 (comp_code == GE_EXPR
6274 ? comp_op1 : comp_op0)))));
6281 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
6282 we might still be able to simplify this. For example,
6283 if C1 is one less or one more than C2, this might have started
6284 out as a MIN or MAX and been transformed by this function.
6285 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
6287 if (INTEGRAL_TYPE_P (type)
6288 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6289 && TREE_CODE (arg2) == INTEGER_CST)
6293 /* We can replace A with C1 in this case. */
6294 arg1 = convert (type, TREE_OPERAND (arg0, 1));
6295 t = build (code, type, TREE_OPERAND (t, 0), arg1,
6296 TREE_OPERAND (t, 2));
6300 /* If C1 is C2 + 1, this is min(A, C2). */
6301 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6302 && operand_equal_p (TREE_OPERAND (arg0, 1),
6303 const_binop (PLUS_EXPR, arg2,
6304 integer_one_node, 0), 1))
6305 return pedantic_non_lvalue
6306 (fold (build (MIN_EXPR, type, arg1, arg2)));
6310 /* If C1 is C2 - 1, this is min(A, C2). */
6311 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6312 && operand_equal_p (TREE_OPERAND (arg0, 1),
6313 const_binop (MINUS_EXPR, arg2,
6314 integer_one_node, 0), 1))
6315 return pedantic_non_lvalue
6316 (fold (build (MIN_EXPR, type, arg1, arg2)));
6320 /* If C1 is C2 - 1, this is max(A, C2). */
6321 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6322 && operand_equal_p (TREE_OPERAND (arg0, 1),
6323 const_binop (MINUS_EXPR, arg2,
6324 integer_one_node, 0), 1))
6325 return pedantic_non_lvalue
6326 (fold (build (MAX_EXPR, type, arg1, arg2)));
6330 /* If C1 is C2 + 1, this is max(A, C2). */
6331 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6332 && operand_equal_p (TREE_OPERAND (arg0, 1),
6333 const_binop (PLUS_EXPR, arg2,
6334 integer_one_node, 0), 1))
6335 return pedantic_non_lvalue
6336 (fold (build (MAX_EXPR, type, arg1, arg2)));
6345 /* If the second operand is simpler than the third, swap them
6346 since that produces better jump optimization results. */
6347 if ((TREE_CONSTANT (arg1) || TREE_CODE_CLASS (TREE_CODE (arg1)) == 'd'
6348 || TREE_CODE (arg1) == SAVE_EXPR)
6349 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
6350 || TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (t, 2))) == 'd'
6351 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
6353 /* See if this can be inverted. If it can't, possibly because
6354 it was a floating-point inequality comparison, don't do
6356 tem = invert_truthvalue (arg0);
6358 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6360 t = build (code, type, tem,
6361 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6363 /* arg1 should be the first argument of the new T. */
6364 arg1 = TREE_OPERAND (t, 1);
6369 /* Convert A ? 1 : 0 to simply A. */
6370 if (integer_onep (TREE_OPERAND (t, 1))
6371 && integer_zerop (TREE_OPERAND (t, 2))
6372 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
6373 call to fold will try to move the conversion inside
6374 a COND, which will recurse. In that case, the COND_EXPR
6375 is probably the best choice, so leave it alone. */
6376 && type == TREE_TYPE (arg0))
6377 return pedantic_non_lvalue (arg0);
6379 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
6380 operation is simply A & 2. */
6382 if (integer_zerop (TREE_OPERAND (t, 2))
6383 && TREE_CODE (arg0) == NE_EXPR
6384 && integer_zerop (TREE_OPERAND (arg0, 1))
6385 && integer_pow2p (arg1)
6386 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
6387 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
6389 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
6394 /* When pedantic, a compound expression can be neither an lvalue
6395 nor an integer constant expression. */
6396 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
6398 /* Don't let (0, 0) be null pointer constant. */
6399 if (integer_zerop (arg1))
6400 return build1 (NOP_EXPR, TREE_TYPE (arg1), arg1);
6405 return build_complex (type, arg0, arg1);
6409 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6411 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6412 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
6413 TREE_OPERAND (arg0, 1));
6414 else if (TREE_CODE (arg0) == COMPLEX_CST)
6415 return TREE_REALPART (arg0);
6416 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6417 return fold (build (TREE_CODE (arg0), type,
6418 fold (build1 (REALPART_EXPR, type,
6419 TREE_OPERAND (arg0, 0))),
6420 fold (build1 (REALPART_EXPR,
6421 type, TREE_OPERAND (arg0, 1)))));
6425 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6426 return convert (type, integer_zero_node);
6427 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6428 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
6429 TREE_OPERAND (arg0, 0));
6430 else if (TREE_CODE (arg0) == COMPLEX_CST)
6431 return TREE_IMAGPART (arg0);
6432 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6433 return fold (build (TREE_CODE (arg0), type,
6434 fold (build1 (IMAGPART_EXPR, type,
6435 TREE_OPERAND (arg0, 0))),
6436 fold (build1 (IMAGPART_EXPR, type,
6437 TREE_OPERAND (arg0, 1)))));
6440 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
6442 case CLEANUP_POINT_EXPR:
6443 if (! has_cleanups (arg0))
6444 return TREE_OPERAND (t, 0);
6447 enum tree_code code0 = TREE_CODE (arg0);
6448 int kind0 = TREE_CODE_CLASS (code0);
6449 tree arg00 = TREE_OPERAND (arg0, 0);
6452 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
6453 return fold (build1 (code0, type,
6454 fold (build1 (CLEANUP_POINT_EXPR,
6455 TREE_TYPE (arg00), arg00))));
6457 if (kind0 == '<' || kind0 == '2'
6458 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
6459 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
6460 || code0 == TRUTH_XOR_EXPR)
6462 arg01 = TREE_OPERAND (arg0, 1);
6464 if (TREE_CONSTANT (arg00)
6465 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
6466 && ! has_cleanups (arg00)))
6467 return fold (build (code0, type, arg00,
6468 fold (build1 (CLEANUP_POINT_EXPR,
6469 TREE_TYPE (arg01), arg01))));
6471 if (TREE_CONSTANT (arg01))
6472 return fold (build (code0, type,
6473 fold (build1 (CLEANUP_POINT_EXPR,
6474 TREE_TYPE (arg00), arg00)),
6483 } /* switch (code) */
6486 /* Determine if first argument is a multiple of second argument.
6487 Return 0 if it is not, or is not easily determined to so be.
6489 An example of the sort of thing we care about (at this point --
6490 this routine could surely be made more general, and expanded
6491 to do what the *_DIV_EXPR's fold() cases do now) is discovering
6494 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
6500 when we know that the two `SAVE_EXPR (J * 8)' nodes are the
6501 same node (which means they will have the same value at run
6502 time, even though we don't know when they'll be assigned).
6504 This code also handles discovering that
6506 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
6512 (of course) so we don't have to worry about dealing with a
6515 Note that we _look_ inside a SAVE_EXPR only to determine
6516 how it was calculated; it is not safe for fold() to do much
6517 of anything else with the internals of a SAVE_EXPR, since
6518 fold() cannot know when it will be evaluated at run time.
6519 For example, the latter example above _cannot_ be implemented
6524 or any variant thereof, since the value of J at evaluation time
6525 of the original SAVE_EXPR is not necessarily the same at the time
6526 the new expression is evaluated. The only optimization of this
6527 sort that would be valid is changing
6529 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
6535 SAVE_EXPR (I) * SAVE_EXPR (J)
6537 (where the same SAVE_EXPR (J) is used in the original and the
6538 transformed version). */
6541 multiple_of_p (type, top, bottom)
6546 if (operand_equal_p (top, bottom, 0))
6549 if (TREE_CODE (type) != INTEGER_TYPE)
6552 switch (TREE_CODE (top))
6555 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
6556 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
6560 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
6561 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
6564 /* Punt if conversion from non-integral or wider integral type. */
6565 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
6566 || (TYPE_PRECISION (type)
6567 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
6571 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
6574 if ((TREE_CODE (bottom) != INTEGER_CST)
6575 || (tree_int_cst_sgn (top) < 0)
6576 || (tree_int_cst_sgn (bottom) < 0))
6578 return integer_zerop (const_binop (TRUNC_MOD_EXPR,