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 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2095 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2096 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2099 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2100 We don't care about side effects in that case because the SAVE_EXPR
2101 takes care of that for us. In all other cases, two expressions are
2102 equal if they have no side effects. If we have two identical
2103 expressions with side effects that should be treated the same due
2104 to the only side effects being identical SAVE_EXPR's, that will
2105 be detected in the recursive calls below. */
2106 if (arg0 == arg1 && ! only_const
2107 && (TREE_CODE (arg0) == SAVE_EXPR
2108 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2111 /* Next handle constant cases, those for which we can return 1 even
2112 if ONLY_CONST is set. */
2113 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2114 switch (TREE_CODE (arg0))
2117 return (! TREE_CONSTANT_OVERFLOW (arg0)
2118 && ! TREE_CONSTANT_OVERFLOW (arg1)
2119 && TREE_INT_CST_LOW (arg0) == TREE_INT_CST_LOW (arg1)
2120 && TREE_INT_CST_HIGH (arg0) == TREE_INT_CST_HIGH (arg1));
2123 return (! TREE_CONSTANT_OVERFLOW (arg0)
2124 && ! TREE_CONSTANT_OVERFLOW (arg1)
2125 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2126 TREE_REAL_CST (arg1)));
2129 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2131 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2135 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2136 && ! strncmp (TREE_STRING_POINTER (arg0),
2137 TREE_STRING_POINTER (arg1),
2138 TREE_STRING_LENGTH (arg0)));
2141 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2150 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2153 /* Two conversions are equal only if signedness and modes match. */
2154 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2155 && (TREE_UNSIGNED (TREE_TYPE (arg0))
2156 != TREE_UNSIGNED (TREE_TYPE (arg1))))
2159 return operand_equal_p (TREE_OPERAND (arg0, 0),
2160 TREE_OPERAND (arg1, 0), 0);
2164 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
2165 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
2169 /* For commutative ops, allow the other order. */
2170 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
2171 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
2172 || TREE_CODE (arg0) == BIT_IOR_EXPR
2173 || TREE_CODE (arg0) == BIT_XOR_EXPR
2174 || TREE_CODE (arg0) == BIT_AND_EXPR
2175 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
2176 && operand_equal_p (TREE_OPERAND (arg0, 0),
2177 TREE_OPERAND (arg1, 1), 0)
2178 && operand_equal_p (TREE_OPERAND (arg0, 1),
2179 TREE_OPERAND (arg1, 0), 0));
2182 switch (TREE_CODE (arg0))
2185 return operand_equal_p (TREE_OPERAND (arg0, 0),
2186 TREE_OPERAND (arg1, 0), 0);
2190 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2191 TREE_OPERAND (arg1, 0), 0)
2192 && operand_equal_p (TREE_OPERAND (arg0, 1),
2193 TREE_OPERAND (arg1, 1), 0));
2196 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2197 TREE_OPERAND (arg1, 0), 0)
2198 && operand_equal_p (TREE_OPERAND (arg0, 1),
2199 TREE_OPERAND (arg1, 1), 0)
2200 && operand_equal_p (TREE_OPERAND (arg0, 2),
2201 TREE_OPERAND (arg1, 2), 0));
2207 if (TREE_CODE (arg0) == RTL_EXPR)
2208 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2216 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2217 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2219 When in doubt, return 0. */
2222 operand_equal_for_comparison_p (arg0, arg1, other)
2226 int unsignedp1, unsignedpo;
2227 tree primarg0, primarg1, primother;
2228 unsigned correct_width;
2230 if (operand_equal_p (arg0, arg1, 0))
2233 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2234 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2237 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2238 and see if the inner values are the same. This removes any
2239 signedness comparison, which doesn't matter here. */
2240 primarg0 = arg0, primarg1 = arg1;
2241 STRIP_NOPS (primarg0); STRIP_NOPS (primarg1);
2242 if (operand_equal_p (primarg0, primarg1, 0))
2245 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2246 actual comparison operand, ARG0.
2248 First throw away any conversions to wider types
2249 already present in the operands. */
2251 primarg1 = get_narrower (arg1, &unsignedp1);
2252 primother = get_narrower (other, &unsignedpo);
2254 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2255 if (unsignedp1 == unsignedpo
2256 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2257 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2259 tree type = TREE_TYPE (arg0);
2261 /* Make sure shorter operand is extended the right way
2262 to match the longer operand. */
2263 primarg1 = convert (signed_or_unsigned_type (unsignedp1,
2264 TREE_TYPE (primarg1)),
2267 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2274 /* See if ARG is an expression that is either a comparison or is performing
2275 arithmetic on comparisons. The comparisons must only be comparing
2276 two different values, which will be stored in *CVAL1 and *CVAL2; if
2277 they are non-zero it means that some operands have already been found.
2278 No variables may be used anywhere else in the expression except in the
2279 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2280 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2282 If this is true, return 1. Otherwise, return zero. */
2285 twoval_comparison_p (arg, cval1, cval2, save_p)
2287 tree *cval1, *cval2;
2290 enum tree_code code = TREE_CODE (arg);
2291 char class = TREE_CODE_CLASS (code);
2293 /* We can handle some of the 'e' cases here. */
2294 if (class == 'e' && code == TRUTH_NOT_EXPR)
2296 else if (class == 'e'
2297 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2298 || code == COMPOUND_EXPR))
2301 /* ??? Disable this since the SAVE_EXPR might already be in use outside
2302 the expression. There may be no way to make this work, but it needs
2303 to be looked at again for 2.6. */
2305 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0)
2307 /* If we've already found a CVAL1 or CVAL2, this expression is
2308 two complex to handle. */
2309 if (*cval1 || *cval2)
2320 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2323 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2324 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2325 cval1, cval2, save_p));
2331 if (code == COND_EXPR)
2332 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2333 cval1, cval2, save_p)
2334 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2335 cval1, cval2, save_p)
2336 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2337 cval1, cval2, save_p));
2341 /* First see if we can handle the first operand, then the second. For
2342 the second operand, we know *CVAL1 can't be zero. It must be that
2343 one side of the comparison is each of the values; test for the
2344 case where this isn't true by failing if the two operands
2347 if (operand_equal_p (TREE_OPERAND (arg, 0),
2348 TREE_OPERAND (arg, 1), 0))
2352 *cval1 = TREE_OPERAND (arg, 0);
2353 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2355 else if (*cval2 == 0)
2356 *cval2 = TREE_OPERAND (arg, 0);
2357 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2362 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2364 else if (*cval2 == 0)
2365 *cval2 = TREE_OPERAND (arg, 1);
2366 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2378 /* ARG is a tree that is known to contain just arithmetic operations and
2379 comparisons. Evaluate the operations in the tree substituting NEW0 for
2380 any occurrence of OLD0 as an operand of a comparison and likewise for
2384 eval_subst (arg, old0, new0, old1, new1)
2386 tree old0, new0, old1, new1;
2388 tree type = TREE_TYPE (arg);
2389 enum tree_code code = TREE_CODE (arg);
2390 char class = TREE_CODE_CLASS (code);
2392 /* We can handle some of the 'e' cases here. */
2393 if (class == 'e' && code == TRUTH_NOT_EXPR)
2395 else if (class == 'e'
2396 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2402 return fold (build1 (code, type,
2403 eval_subst (TREE_OPERAND (arg, 0),
2404 old0, new0, old1, new1)));
2407 return fold (build (code, type,
2408 eval_subst (TREE_OPERAND (arg, 0),
2409 old0, new0, old1, new1),
2410 eval_subst (TREE_OPERAND (arg, 1),
2411 old0, new0, old1, new1)));
2417 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2420 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2423 return fold (build (code, type,
2424 eval_subst (TREE_OPERAND (arg, 0),
2425 old0, new0, old1, new1),
2426 eval_subst (TREE_OPERAND (arg, 1),
2427 old0, new0, old1, new1),
2428 eval_subst (TREE_OPERAND (arg, 2),
2429 old0, new0, old1, new1)));
2433 /* fall through - ??? */
2437 tree arg0 = TREE_OPERAND (arg, 0);
2438 tree arg1 = TREE_OPERAND (arg, 1);
2440 /* We need to check both for exact equality and tree equality. The
2441 former will be true if the operand has a side-effect. In that
2442 case, we know the operand occurred exactly once. */
2444 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2446 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2449 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2451 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2454 return fold (build (code, type, arg0, arg1));
2462 /* Return a tree for the case when the result of an expression is RESULT
2463 converted to TYPE and OMITTED was previously an operand of the expression
2464 but is now not needed (e.g., we folded OMITTED * 0).
2466 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2467 the conversion of RESULT to TYPE. */
2470 omit_one_operand (type, result, omitted)
2471 tree type, result, omitted;
2473 tree t = convert (type, result);
2475 if (TREE_SIDE_EFFECTS (omitted))
2476 return build (COMPOUND_EXPR, type, omitted, t);
2478 return non_lvalue (t);
2481 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2484 pedantic_omit_one_operand (type, result, omitted)
2485 tree type, result, omitted;
2487 tree t = convert (type, result);
2489 if (TREE_SIDE_EFFECTS (omitted))
2490 return build (COMPOUND_EXPR, type, omitted, t);
2492 return pedantic_non_lvalue (t);
2497 /* Return a simplified tree node for the truth-negation of ARG. This
2498 never alters ARG itself. We assume that ARG is an operation that
2499 returns a truth value (0 or 1). */
2502 invert_truthvalue (arg)
2505 tree type = TREE_TYPE (arg);
2506 enum tree_code code = TREE_CODE (arg);
2508 if (code == ERROR_MARK)
2511 /* If this is a comparison, we can simply invert it, except for
2512 floating-point non-equality comparisons, in which case we just
2513 enclose a TRUTH_NOT_EXPR around what we have. */
2515 if (TREE_CODE_CLASS (code) == '<')
2517 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2518 && !flag_fast_math && code != NE_EXPR && code != EQ_EXPR)
2519 return build1 (TRUTH_NOT_EXPR, type, arg);
2521 return build (invert_tree_comparison (code), type,
2522 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2528 return convert (type, build_int_2 (TREE_INT_CST_LOW (arg) == 0
2529 && TREE_INT_CST_HIGH (arg) == 0, 0));
2531 case TRUTH_AND_EXPR:
2532 return build (TRUTH_OR_EXPR, type,
2533 invert_truthvalue (TREE_OPERAND (arg, 0)),
2534 invert_truthvalue (TREE_OPERAND (arg, 1)));
2537 return build (TRUTH_AND_EXPR, type,
2538 invert_truthvalue (TREE_OPERAND (arg, 0)),
2539 invert_truthvalue (TREE_OPERAND (arg, 1)));
2541 case TRUTH_XOR_EXPR:
2542 /* Here we can invert either operand. We invert the first operand
2543 unless the second operand is a TRUTH_NOT_EXPR in which case our
2544 result is the XOR of the first operand with the inside of the
2545 negation of the second operand. */
2547 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2548 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2549 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2551 return build (TRUTH_XOR_EXPR, type,
2552 invert_truthvalue (TREE_OPERAND (arg, 0)),
2553 TREE_OPERAND (arg, 1));
2555 case TRUTH_ANDIF_EXPR:
2556 return build (TRUTH_ORIF_EXPR, type,
2557 invert_truthvalue (TREE_OPERAND (arg, 0)),
2558 invert_truthvalue (TREE_OPERAND (arg, 1)));
2560 case TRUTH_ORIF_EXPR:
2561 return build (TRUTH_ANDIF_EXPR, type,
2562 invert_truthvalue (TREE_OPERAND (arg, 0)),
2563 invert_truthvalue (TREE_OPERAND (arg, 1)));
2565 case TRUTH_NOT_EXPR:
2566 return TREE_OPERAND (arg, 0);
2569 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2570 invert_truthvalue (TREE_OPERAND (arg, 1)),
2571 invert_truthvalue (TREE_OPERAND (arg, 2)));
2574 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2575 invert_truthvalue (TREE_OPERAND (arg, 1)));
2577 case NON_LVALUE_EXPR:
2578 return invert_truthvalue (TREE_OPERAND (arg, 0));
2583 return build1 (TREE_CODE (arg), type,
2584 invert_truthvalue (TREE_OPERAND (arg, 0)));
2587 if (!integer_onep (TREE_OPERAND (arg, 1)))
2589 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2592 return build1 (TRUTH_NOT_EXPR, type, arg);
2594 case CLEANUP_POINT_EXPR:
2595 return build1 (CLEANUP_POINT_EXPR, type,
2596 invert_truthvalue (TREE_OPERAND (arg, 0)));
2601 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2603 return build1 (TRUTH_NOT_EXPR, type, arg);
2606 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2607 operands are another bit-wise operation with a common input. If so,
2608 distribute the bit operations to save an operation and possibly two if
2609 constants are involved. For example, convert
2610 (A | B) & (A | C) into A | (B & C)
2611 Further simplification will occur if B and C are constants.
2613 If this optimization cannot be done, 0 will be returned. */
2616 distribute_bit_expr (code, type, arg0, arg1)
2617 enum tree_code code;
2624 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2625 || TREE_CODE (arg0) == code
2626 || (TREE_CODE (arg0) != BIT_AND_EXPR
2627 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2630 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2632 common = TREE_OPERAND (arg0, 0);
2633 left = TREE_OPERAND (arg0, 1);
2634 right = TREE_OPERAND (arg1, 1);
2636 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2638 common = TREE_OPERAND (arg0, 0);
2639 left = TREE_OPERAND (arg0, 1);
2640 right = TREE_OPERAND (arg1, 0);
2642 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2644 common = TREE_OPERAND (arg0, 1);
2645 left = TREE_OPERAND (arg0, 0);
2646 right = TREE_OPERAND (arg1, 1);
2648 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2650 common = TREE_OPERAND (arg0, 1);
2651 left = TREE_OPERAND (arg0, 0);
2652 right = TREE_OPERAND (arg1, 0);
2657 return fold (build (TREE_CODE (arg0), type, common,
2658 fold (build (code, type, left, right))));
2661 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2662 starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */
2665 make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp)
2668 int bitsize, bitpos;
2671 tree result = build (BIT_FIELD_REF, type, inner,
2672 size_int (bitsize), bitsize_int (bitpos, 0L));
2674 TREE_UNSIGNED (result) = unsignedp;
2679 /* Optimize a bit-field compare.
2681 There are two cases: First is a compare against a constant and the
2682 second is a comparison of two items where the fields are at the same
2683 bit position relative to the start of a chunk (byte, halfword, word)
2684 large enough to contain it. In these cases we can avoid the shift
2685 implicit in bitfield extractions.
2687 For constants, we emit a compare of the shifted constant with the
2688 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2689 compared. For two fields at the same position, we do the ANDs with the
2690 similar mask and compare the result of the ANDs.
2692 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2693 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2694 are the left and right operands of the comparison, respectively.
2696 If the optimization described above can be done, we return the resulting
2697 tree. Otherwise we return zero. */
2700 optimize_bit_field_compare (code, compare_type, lhs, rhs)
2701 enum tree_code code;
2705 int lbitpos, lbitsize, rbitpos, rbitsize;
2706 int lnbitpos, lnbitsize, rnbitpos = 0, rnbitsize = 0;
2707 tree type = TREE_TYPE (lhs);
2708 tree signed_type, unsigned_type;
2709 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2710 enum machine_mode lmode, rmode, lnmode, rnmode = VOIDmode;
2711 int lunsignedp, runsignedp;
2712 int lvolatilep = 0, rvolatilep = 0;
2714 tree linner, rinner = NULL_TREE;
2718 /* Get all the information about the extractions being done. If the bit size
2719 if the same as the size of the underlying object, we aren't doing an
2720 extraction at all and so can do nothing. */
2721 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2722 &lunsignedp, &lvolatilep, &alignment);
2723 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2729 /* If this is not a constant, we can only do something if bit positions,
2730 sizes, and signedness are the same. */
2731 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2732 &runsignedp, &rvolatilep, &alignment);
2734 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2735 || lunsignedp != runsignedp || offset != 0)
2739 /* See if we can find a mode to refer to this field. We should be able to,
2740 but fail if we can't. */
2741 lnmode = get_best_mode (lbitsize, lbitpos,
2742 TYPE_ALIGN (TREE_TYPE (linner)), word_mode,
2744 if (lnmode == VOIDmode)
2747 /* Set signed and unsigned types of the precision of this mode for the
2749 signed_type = type_for_mode (lnmode, 0);
2750 unsigned_type = type_for_mode (lnmode, 1);
2754 rnmode = get_best_mode (rbitsize, rbitpos,
2755 TYPE_ALIGN (TREE_TYPE (rinner)), word_mode,
2757 if (rnmode == VOIDmode)
2761 /* Compute the bit position and size for the new reference and our offset
2762 within it. If the new reference is the same size as the original, we
2763 won't optimize anything, so return zero. */
2764 lnbitsize = GET_MODE_BITSIZE (lnmode);
2765 lnbitpos = lbitpos & ~ (lnbitsize - 1);
2766 lbitpos -= lnbitpos;
2767 if (lnbitsize == lbitsize)
2772 rnbitsize = GET_MODE_BITSIZE (rnmode);
2773 rnbitpos = rbitpos & ~ (rnbitsize - 1);
2774 rbitpos -= rnbitpos;
2775 if (rnbitsize == rbitsize)
2779 if (BYTES_BIG_ENDIAN)
2780 lbitpos = lnbitsize - lbitsize - lbitpos;
2782 /* Make the mask to be used against the extracted field. */
2783 mask = build_int_2 (~0, ~0);
2784 TREE_TYPE (mask) = unsigned_type;
2785 force_fit_type (mask, 0);
2786 mask = convert (unsigned_type, mask);
2787 mask = const_binop (LSHIFT_EXPR, mask, size_int (lnbitsize - lbitsize), 0);
2788 mask = const_binop (RSHIFT_EXPR, mask,
2789 size_int (lnbitsize - lbitsize - lbitpos), 0);
2792 /* If not comparing with constant, just rework the comparison
2794 return build (code, compare_type,
2795 build (BIT_AND_EXPR, unsigned_type,
2796 make_bit_field_ref (linner, unsigned_type,
2797 lnbitsize, lnbitpos, 1),
2799 build (BIT_AND_EXPR, unsigned_type,
2800 make_bit_field_ref (rinner, unsigned_type,
2801 rnbitsize, rnbitpos, 1),
2804 /* Otherwise, we are handling the constant case. See if the constant is too
2805 big for the field. Warn and return a tree of for 0 (false) if so. We do
2806 this not only for its own sake, but to avoid having to test for this
2807 error case below. If we didn't, we might generate wrong code.
2809 For unsigned fields, the constant shifted right by the field length should
2810 be all zero. For signed fields, the high-order bits should agree with
2815 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2816 convert (unsigned_type, rhs),
2817 size_int (lbitsize), 0)))
2819 warning ("comparison is always %d due to width of bitfield",
2821 return convert (compare_type,
2823 ? integer_one_node : integer_zero_node));
2828 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
2829 size_int (lbitsize - 1), 0);
2830 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2832 warning ("comparison is always %d due to width of bitfield",
2834 return convert (compare_type,
2836 ? integer_one_node : integer_zero_node));
2840 /* Single-bit compares should always be against zero. */
2841 if (lbitsize == 1 && ! integer_zerop (rhs))
2843 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2844 rhs = convert (type, integer_zero_node);
2847 /* Make a new bitfield reference, shift the constant over the
2848 appropriate number of bits and mask it with the computed mask
2849 (in case this was a signed field). If we changed it, make a new one. */
2850 lhs = make_bit_field_ref (linner, unsigned_type, lnbitsize, lnbitpos, 1);
2853 TREE_SIDE_EFFECTS (lhs) = 1;
2854 TREE_THIS_VOLATILE (lhs) = 1;
2857 rhs = fold (const_binop (BIT_AND_EXPR,
2858 const_binop (LSHIFT_EXPR,
2859 convert (unsigned_type, rhs),
2860 size_int (lbitpos), 0),
2863 return build (code, compare_type,
2864 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2868 /* Subroutine for fold_truthop: decode a field reference.
2870 If EXP is a comparison reference, we return the innermost reference.
2872 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2873 set to the starting bit number.
2875 If the innermost field can be completely contained in a mode-sized
2876 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2878 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2879 otherwise it is not changed.
2881 *PUNSIGNEDP is set to the signedness of the field.
2883 *PMASK is set to the mask used. This is either contained in a
2884 BIT_AND_EXPR or derived from the width of the field.
2886 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2888 Return 0 if this is not a component reference or is one that we can't
2889 do anything with. */
2892 decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp,
2893 pvolatilep, pmask, pand_mask)
2895 int *pbitsize, *pbitpos;
2896 enum machine_mode *pmode;
2897 int *punsignedp, *pvolatilep;
2902 tree mask, inner, offset;
2907 /* All the optimizations using this function assume integer fields.
2908 There are problems with FP fields since the type_for_size call
2909 below can fail for, e.g., XFmode. */
2910 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
2915 if (TREE_CODE (exp) == BIT_AND_EXPR)
2917 and_mask = TREE_OPERAND (exp, 1);
2918 exp = TREE_OPERAND (exp, 0);
2919 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
2920 if (TREE_CODE (and_mask) != INTEGER_CST)
2925 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
2926 punsignedp, pvolatilep, &alignment);
2927 if ((inner == exp && and_mask == 0)
2928 || *pbitsize < 0 || offset != 0)
2931 /* Compute the mask to access the bitfield. */
2932 unsigned_type = type_for_size (*pbitsize, 1);
2933 precision = TYPE_PRECISION (unsigned_type);
2935 mask = build_int_2 (~0, ~0);
2936 TREE_TYPE (mask) = unsigned_type;
2937 force_fit_type (mask, 0);
2938 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2939 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2941 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
2943 mask = fold (build (BIT_AND_EXPR, unsigned_type,
2944 convert (unsigned_type, and_mask), mask));
2947 *pand_mask = and_mask;
2951 /* Return non-zero if MASK represents a mask of SIZE ones in the low-order
2955 all_ones_mask_p (mask, size)
2959 tree type = TREE_TYPE (mask);
2960 int precision = TYPE_PRECISION (type);
2963 tmask = build_int_2 (~0, ~0);
2964 TREE_TYPE (tmask) = signed_type (type);
2965 force_fit_type (tmask, 0);
2967 tree_int_cst_equal (mask,
2968 const_binop (RSHIFT_EXPR,
2969 const_binop (LSHIFT_EXPR, tmask,
2970 size_int (precision - size),
2972 size_int (precision - size), 0));
2975 /* Subroutine for fold_truthop: determine if an operand is simple enough
2976 to be evaluated unconditionally. */
2979 simple_operand_p (exp)
2982 /* Strip any conversions that don't change the machine mode. */
2983 while ((TREE_CODE (exp) == NOP_EXPR
2984 || TREE_CODE (exp) == CONVERT_EXPR)
2985 && (TYPE_MODE (TREE_TYPE (exp))
2986 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
2987 exp = TREE_OPERAND (exp, 0);
2989 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
2990 || (TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
2991 && ! TREE_ADDRESSABLE (exp)
2992 && ! TREE_THIS_VOLATILE (exp)
2993 && ! DECL_NONLOCAL (exp)
2994 /* Don't regard global variables as simple. They may be
2995 allocated in ways unknown to the compiler (shared memory,
2996 #pragma weak, etc). */
2997 && ! TREE_PUBLIC (exp)
2998 && ! DECL_EXTERNAL (exp)
2999 /* Loading a static variable is unduly expensive, but global
3000 registers aren't expensive. */
3001 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3004 /* The following functions are subroutines to fold_range_test and allow it to
3005 try to change a logical combination of comparisons into a range test.
3008 X == 2 && X == 3 && X == 4 && X == 5
3012 (unsigned) (X - 2) <= 3
3014 We describe each set of comparisons as being either inside or outside
3015 a range, using a variable named like IN_P, and then describe the
3016 range with a lower and upper bound. If one of the bounds is omitted,
3017 it represents either the highest or lowest value of the type.
3019 In the comments below, we represent a range by two numbers in brackets
3020 preceded by a "+" to designate being inside that range, or a "-" to
3021 designate being outside that range, so the condition can be inverted by
3022 flipping the prefix. An omitted bound is represented by a "-". For
3023 example, "- [-, 10]" means being outside the range starting at the lowest
3024 possible value and ending at 10, in other words, being greater than 10.
3025 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3028 We set up things so that the missing bounds are handled in a consistent
3029 manner so neither a missing bound nor "true" and "false" need to be
3030 handled using a special case. */
3032 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3033 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3034 and UPPER1_P are nonzero if the respective argument is an upper bound
3035 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3036 must be specified for a comparison. ARG1 will be converted to ARG0's
3037 type if both are specified. */
3040 range_binop (code, type, arg0, upper0_p, arg1, upper1_p)
3041 enum tree_code code;
3044 int upper0_p, upper1_p;
3050 /* If neither arg represents infinity, do the normal operation.
3051 Else, if not a comparison, return infinity. Else handle the special
3052 comparison rules. Note that most of the cases below won't occur, but
3053 are handled for consistency. */
3055 if (arg0 != 0 && arg1 != 0)
3057 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
3058 arg0, convert (TREE_TYPE (arg0), arg1)));
3060 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3063 if (TREE_CODE_CLASS (code) != '<')
3066 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3067 for neither. In real maths, we cannot assume open ended ranges are
3068 the same. But, this is computer arithmetic, where numbers are finite.
3069 We can therefore make the transformation of any unbounded range with
3070 the value Z, Z being greater than any representable number. This permits
3071 us to treat unbounded ranges as equal. */
3072 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3073 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3077 result = sgn0 == sgn1;
3080 result = sgn0 != sgn1;
3083 result = sgn0 < sgn1;
3086 result = sgn0 <= sgn1;
3089 result = sgn0 > sgn1;
3092 result = sgn0 >= sgn1;
3098 return convert (type, result ? integer_one_node : integer_zero_node);
3101 /* Given EXP, a logical expression, set the range it is testing into
3102 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3103 actually being tested. *PLOW and *PHIGH will have be made the same type
3104 as the returned expression. If EXP is not a comparison, we will most
3105 likely not be returning a useful value and range. */
3108 make_range (exp, pin_p, plow, phigh)
3113 enum tree_code code;
3114 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
3115 tree orig_type = NULL_TREE;
3117 tree low, high, n_low, n_high;
3119 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3120 and see if we can refine the range. Some of the cases below may not
3121 happen, but it doesn't seem worth worrying about this. We "continue"
3122 the outer loop when we've changed something; otherwise we "break"
3123 the switch, which will "break" the while. */
3125 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
3129 code = TREE_CODE (exp);
3131 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3133 arg0 = TREE_OPERAND (exp, 0);
3134 if (TREE_CODE_CLASS (code) == '<'
3135 || TREE_CODE_CLASS (code) == '1'
3136 || TREE_CODE_CLASS (code) == '2')
3137 type = TREE_TYPE (arg0);
3138 if (TREE_CODE_CLASS (code) == '2'
3139 || TREE_CODE_CLASS (code) == '<'
3140 || (TREE_CODE_CLASS (code) == 'e'
3141 && tree_code_length[(int) code] > 1))
3142 arg1 = TREE_OPERAND (exp, 1);
3145 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3146 lose a cast by accident. */
3147 if (type != NULL_TREE && orig_type == NULL_TREE)
3152 case TRUTH_NOT_EXPR:
3153 in_p = ! in_p, exp = arg0;
3156 case EQ_EXPR: case NE_EXPR:
3157 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3158 /* We can only do something if the range is testing for zero
3159 and if the second operand is an integer constant. Note that
3160 saying something is "in" the range we make is done by
3161 complementing IN_P since it will set in the initial case of
3162 being not equal to zero; "out" is leaving it alone. */
3163 if (low == 0 || high == 0
3164 || ! integer_zerop (low) || ! integer_zerop (high)
3165 || TREE_CODE (arg1) != INTEGER_CST)
3170 case NE_EXPR: /* - [c, c] */
3173 case EQ_EXPR: /* + [c, c] */
3174 in_p = ! in_p, low = high = arg1;
3176 case GT_EXPR: /* - [-, c] */
3177 low = 0, high = arg1;
3179 case GE_EXPR: /* + [c, -] */
3180 in_p = ! in_p, low = arg1, high = 0;
3182 case LT_EXPR: /* - [c, -] */
3183 low = arg1, high = 0;
3185 case LE_EXPR: /* + [-, c] */
3186 in_p = ! in_p, low = 0, high = arg1;
3194 /* If this is an unsigned comparison, we also know that EXP is
3195 greater than or equal to zero. We base the range tests we make
3196 on that fact, so we record it here so we can parse existing
3198 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3200 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3201 1, convert (type, integer_zero_node),
3205 in_p = n_in_p, low = n_low, high = n_high;
3207 /* If the high bound is missing, reverse the range so it
3208 goes from zero to the low bound minus 1. */
3212 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3213 integer_one_node, 0);
3214 low = convert (type, integer_zero_node);
3220 /* (-x) IN [a,b] -> x in [-b, -a] */
3221 n_low = range_binop (MINUS_EXPR, type,
3222 convert (type, integer_zero_node), 0, high, 1);
3223 n_high = range_binop (MINUS_EXPR, type,
3224 convert (type, integer_zero_node), 0, low, 0);
3225 low = n_low, high = n_high;
3231 exp = build (MINUS_EXPR, type, build1 (NEGATE_EXPR, type, arg0),
3232 convert (type, integer_one_node));
3235 case PLUS_EXPR: case MINUS_EXPR:
3236 if (TREE_CODE (arg1) != INTEGER_CST)
3239 /* If EXP is signed, any overflow in the computation is undefined,
3240 so we don't worry about it so long as our computations on
3241 the bounds don't overflow. For unsigned, overflow is defined
3242 and this is exactly the right thing. */
3243 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3244 type, low, 0, arg1, 0);
3245 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3246 type, high, 1, arg1, 0);
3247 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3248 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3251 /* Check for an unsigned range which has wrapped around the maximum
3252 value thus making n_high < n_low, and normalize it. */
3253 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3255 low = range_binop (PLUS_EXPR, type, n_high, 0,
3256 integer_one_node, 0);
3257 high = range_binop (MINUS_EXPR, type, n_low, 0,
3258 integer_one_node, 0);
3262 low = n_low, high = n_high;
3267 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3268 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3271 if (! INTEGRAL_TYPE_P (type)
3272 || (low != 0 && ! int_fits_type_p (low, type))
3273 || (high != 0 && ! int_fits_type_p (high, type)))
3276 n_low = low, n_high = high;
3279 n_low = convert (type, n_low);
3282 n_high = convert (type, n_high);
3284 /* If we're converting from an unsigned to a signed type,
3285 we will be doing the comparison as unsigned. The tests above
3286 have already verified that LOW and HIGH are both positive.
3288 So we have to make sure that the original unsigned value will
3289 be interpreted as positive. */
3290 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3292 tree equiv_type = type_for_mode (TYPE_MODE (type), 1);
3295 /* A range without an upper bound is, naturally, unbounded.
3296 Since convert would have cropped a very large value, use
3297 the max value for the destination type. */
3299 high_positive = TYPE_MAX_VALUE (equiv_type);
3302 high_positive = TYPE_MAX_VALUE (type);
3306 high_positive = fold (build (RSHIFT_EXPR, type,
3307 convert (type, high_positive),
3308 convert (type, integer_one_node)));
3310 /* If the low bound is specified, "and" the range with the
3311 range for which the original unsigned value will be
3315 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3317 1, convert (type, integer_zero_node),
3321 in_p = (n_in_p == in_p);
3325 /* Otherwise, "or" the range with the range of the input
3326 that will be interpreted as negative. */
3327 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3329 1, convert (type, integer_zero_node),
3333 in_p = (in_p != n_in_p);
3338 low = n_low, high = n_high;
3348 /* If EXP is a constant, we can evaluate whether this is true or false. */
3349 if (TREE_CODE (exp) == INTEGER_CST)
3351 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3353 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3359 *pin_p = in_p, *plow = low, *phigh = high;
3363 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3364 type, TYPE, return an expression to test if EXP is in (or out of, depending
3365 on IN_P) the range. */
3368 build_range_check (type, exp, in_p, low, high)
3374 tree etype = TREE_TYPE (exp);
3378 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3379 return invert_truthvalue (value);
3381 else if (low == 0 && high == 0)
3382 return convert (type, integer_one_node);
3385 return fold (build (LE_EXPR, type, exp, high));
3388 return fold (build (GE_EXPR, type, exp, low));
3390 else if (operand_equal_p (low, high, 0))
3391 return fold (build (EQ_EXPR, type, exp, low));
3393 else if (TREE_UNSIGNED (etype) && integer_zerop (low))
3394 return build_range_check (type, exp, 1, 0, high);
3396 else if (integer_zerop (low))
3398 utype = unsigned_type (etype);
3399 return build_range_check (type, convert (utype, exp), 1, 0,
3400 convert (utype, high));
3403 else if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3404 && ! TREE_OVERFLOW (value))
3405 return build_range_check (type,
3406 fold (build (MINUS_EXPR, etype, exp, low)),
3407 1, convert (etype, integer_zero_node), value);
3412 /* Given two ranges, see if we can merge them into one. Return 1 if we
3413 can, 0 if we can't. Set the output range into the specified parameters. */
3416 merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
3420 tree low0, high0, low1, high1;
3428 int lowequal = ((low0 == 0 && low1 == 0)
3429 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3430 low0, 0, low1, 0)));
3431 int highequal = ((high0 == 0 && high1 == 0)
3432 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3433 high0, 1, high1, 1)));
3435 /* Make range 0 be the range that starts first, or ends last if they
3436 start at the same value. Swap them if it isn't. */
3437 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3440 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3441 high1, 1, high0, 1))))
3443 temp = in0_p, in0_p = in1_p, in1_p = temp;
3444 tem = low0, low0 = low1, low1 = tem;
3445 tem = high0, high0 = high1, high1 = tem;
3448 /* Now flag two cases, whether the ranges are disjoint or whether the
3449 second range is totally subsumed in the first. Note that the tests
3450 below are simplified by the ones above. */
3451 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3452 high0, 1, low1, 0));
3453 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3454 high1, 1, high0, 1));
3456 /* We now have four cases, depending on whether we are including or
3457 excluding the two ranges. */
3460 /* If they don't overlap, the result is false. If the second range
3461 is a subset it is the result. Otherwise, the range is from the start
3462 of the second to the end of the first. */
3464 in_p = 0, low = high = 0;
3466 in_p = 1, low = low1, high = high1;
3468 in_p = 1, low = low1, high = high0;
3471 else if (in0_p && ! in1_p)
3473 /* If they don't overlap, the result is the first range. If they are
3474 equal, the result is false. If the second range is a subset of the
3475 first, and the ranges begin at the same place, we go from just after
3476 the end of the first range to the end of the second. If the second
3477 range is not a subset of the first, or if it is a subset and both
3478 ranges end at the same place, the range starts at the start of the
3479 first range and ends just before the second range.
3480 Otherwise, we can't describe this as a single range. */
3482 in_p = 1, low = low0, high = high0;
3483 else if (lowequal && highequal)
3484 in_p = 0, low = high = 0;
3485 else if (subset && lowequal)
3487 in_p = 1, high = high0;
3488 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3489 integer_one_node, 0);
3491 else if (! subset || highequal)
3493 in_p = 1, low = low0;
3494 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3495 integer_one_node, 0);
3501 else if (! in0_p && in1_p)
3503 /* If they don't overlap, the result is the second range. If the second
3504 is a subset of the first, the result is false. Otherwise,
3505 the range starts just after the first range and ends at the
3506 end of the second. */
3508 in_p = 1, low = low1, high = high1;
3510 in_p = 0, low = high = 0;
3513 in_p = 1, high = high1;
3514 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3515 integer_one_node, 0);
3521 /* The case where we are excluding both ranges. Here the complex case
3522 is if they don't overlap. In that case, the only time we have a
3523 range is if they are adjacent. If the second is a subset of the
3524 first, the result is the first. Otherwise, the range to exclude
3525 starts at the beginning of the first range and ends at the end of the
3529 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3530 range_binop (PLUS_EXPR, NULL_TREE,
3532 integer_one_node, 1),
3534 in_p = 0, low = low0, high = high1;
3539 in_p = 0, low = low0, high = high0;
3541 in_p = 0, low = low0, high = high1;
3544 *pin_p = in_p, *plow = low, *phigh = high;
3548 /* EXP is some logical combination of boolean tests. See if we can
3549 merge it into some range test. Return the new tree if so. */
3552 fold_range_test (exp)
3555 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3556 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3557 int in0_p, in1_p, in_p;
3558 tree low0, low1, low, high0, high1, high;
3559 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3560 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3563 /* Fail if anything is volatile. */
3564 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3567 /* If this is an OR operation, invert both sides; we will invert
3568 again at the end. */
3570 in0_p = ! in0_p, in1_p = ! in1_p;
3572 /* If both expressions are the same, if we can merge the ranges, and we
3573 can build the range test, return it or it inverted. If one of the
3574 ranges is always true or always false, consider it to be the same
3575 expression as the other. */
3576 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3577 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3579 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3581 : rhs != 0 ? rhs : integer_zero_node,
3583 return or_op ? invert_truthvalue (tem) : tem;
3585 /* On machines where the branch cost is expensive, if this is a
3586 short-circuited branch and the underlying object on both sides
3587 is the same, make a non-short-circuit operation. */
3588 else if (BRANCH_COST >= 2
3589 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3590 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3591 && operand_equal_p (lhs, rhs, 0))
3593 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3594 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3595 which cases we can't do this. */
3596 if (simple_operand_p (lhs))
3597 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3598 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3599 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3600 TREE_OPERAND (exp, 1));
3602 else if (current_function_decl != 0
3603 && ! contains_placeholder_p (lhs))
3605 tree common = save_expr (lhs);
3607 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3608 or_op ? ! in0_p : in0_p,
3610 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3611 or_op ? ! in1_p : in1_p,
3613 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3614 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3615 TREE_TYPE (exp), lhs, rhs);
3622 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3623 bit value. Arrange things so the extra bits will be set to zero if and
3624 only if C is signed-extended to its full width. If MASK is nonzero,
3625 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3628 unextend (c, p, unsignedp, mask)
3634 tree type = TREE_TYPE (c);
3635 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3638 if (p == modesize || unsignedp)
3641 /* We work by getting just the sign bit into the low-order bit, then
3642 into the high-order bit, then sign-extend. We then XOR that value
3644 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3645 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3647 /* We must use a signed type in order to get an arithmetic right shift.
3648 However, we must also avoid introducing accidental overflows, so that
3649 a subsequent call to integer_zerop will work. Hence we must
3650 do the type conversion here. At this point, the constant is either
3651 zero or one, and the conversion to a signed type can never overflow.
3652 We could get an overflow if this conversion is done anywhere else. */
3653 if (TREE_UNSIGNED (type))
3654 temp = convert (signed_type (type), temp);
3656 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3657 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3659 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3660 /* If necessary, convert the type back to match the type of C. */
3661 if (TREE_UNSIGNED (type))
3662 temp = convert (type, temp);
3664 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3667 /* Find ways of folding logical expressions of LHS and RHS:
3668 Try to merge two comparisons to the same innermost item.
3669 Look for range tests like "ch >= '0' && ch <= '9'".
3670 Look for combinations of simple terms on machines with expensive branches
3671 and evaluate the RHS unconditionally.
3673 For example, if we have p->a == 2 && p->b == 4 and we can make an
3674 object large enough to span both A and B, we can do this with a comparison
3675 against the object ANDed with the a mask.
3677 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3678 operations to do this with one comparison.
3680 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3681 function and the one above.
3683 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3684 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3686 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3689 We return the simplified tree or 0 if no optimization is possible. */
3692 fold_truthop (code, truth_type, lhs, rhs)
3693 enum tree_code code;
3694 tree truth_type, lhs, rhs;
3696 /* If this is the "or" of two comparisons, we can do something if we
3697 the comparisons are NE_EXPR. If this is the "and", we can do something
3698 if the comparisons are EQ_EXPR. I.e.,
3699 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3701 WANTED_CODE is this operation code. For single bit fields, we can
3702 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3703 comparison for one-bit fields. */
3705 enum tree_code wanted_code;
3706 enum tree_code lcode, rcode;
3707 tree ll_arg, lr_arg, rl_arg, rr_arg;
3708 tree ll_inner, lr_inner, rl_inner, rr_inner;
3709 int ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3710 int rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3711 int xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3712 int lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3713 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3714 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3715 enum machine_mode lnmode, rnmode;
3716 tree ll_mask, lr_mask, rl_mask, rr_mask;
3717 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3718 tree l_const, r_const;
3719 tree lntype, rntype, result;
3720 int first_bit, end_bit;
3723 /* Start by getting the comparison codes. Fail if anything is volatile.
3724 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3725 it were surrounded with a NE_EXPR. */
3727 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3730 lcode = TREE_CODE (lhs);
3731 rcode = TREE_CODE (rhs);
3733 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3734 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3736 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3737 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3739 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3742 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3743 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3745 ll_arg = TREE_OPERAND (lhs, 0);
3746 lr_arg = TREE_OPERAND (lhs, 1);
3747 rl_arg = TREE_OPERAND (rhs, 0);
3748 rr_arg = TREE_OPERAND (rhs, 1);
3750 /* If the RHS can be evaluated unconditionally and its operands are
3751 simple, it wins to evaluate the RHS unconditionally on machines
3752 with expensive branches. In this case, this isn't a comparison
3753 that can be merged. */
3755 /* @@ I'm not sure it wins on the m88110 to do this if the comparisons
3756 are with zero (tmw). */
3758 if (BRANCH_COST >= 2
3759 && INTEGRAL_TYPE_P (TREE_TYPE (rhs))
3760 && simple_operand_p (rl_arg)
3761 && simple_operand_p (rr_arg))
3762 return build (code, truth_type, lhs, rhs);
3764 /* See if the comparisons can be merged. Then get all the parameters for
3767 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3768 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3772 ll_inner = decode_field_reference (ll_arg,
3773 &ll_bitsize, &ll_bitpos, &ll_mode,
3774 &ll_unsignedp, &volatilep, &ll_mask,
3776 lr_inner = decode_field_reference (lr_arg,
3777 &lr_bitsize, &lr_bitpos, &lr_mode,
3778 &lr_unsignedp, &volatilep, &lr_mask,
3780 rl_inner = decode_field_reference (rl_arg,
3781 &rl_bitsize, &rl_bitpos, &rl_mode,
3782 &rl_unsignedp, &volatilep, &rl_mask,
3784 rr_inner = decode_field_reference (rr_arg,
3785 &rr_bitsize, &rr_bitpos, &rr_mode,
3786 &rr_unsignedp, &volatilep, &rr_mask,
3789 /* It must be true that the inner operation on the lhs of each
3790 comparison must be the same if we are to be able to do anything.
3791 Then see if we have constants. If not, the same must be true for
3793 if (volatilep || ll_inner == 0 || rl_inner == 0
3794 || ! operand_equal_p (ll_inner, rl_inner, 0))
3797 if (TREE_CODE (lr_arg) == INTEGER_CST
3798 && TREE_CODE (rr_arg) == INTEGER_CST)
3799 l_const = lr_arg, r_const = rr_arg;
3800 else if (lr_inner == 0 || rr_inner == 0
3801 || ! operand_equal_p (lr_inner, rr_inner, 0))
3804 l_const = r_const = 0;
3806 /* If either comparison code is not correct for our logical operation,
3807 fail. However, we can convert a one-bit comparison against zero into
3808 the opposite comparison against that bit being set in the field. */
3810 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
3811 if (lcode != wanted_code)
3813 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
3815 /* Make the left operand unsigned, since we are only interested
3816 in the value of one bit. Otherwise we are doing the wrong
3825 /* This is analogous to the code for l_const above. */
3826 if (rcode != wanted_code)
3828 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
3837 /* See if we can find a mode that contains both fields being compared on
3838 the left. If we can't, fail. Otherwise, update all constants and masks
3839 to be relative to a field of that size. */
3840 first_bit = MIN (ll_bitpos, rl_bitpos);
3841 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
3842 lnmode = get_best_mode (end_bit - first_bit, first_bit,
3843 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
3845 if (lnmode == VOIDmode)
3848 lnbitsize = GET_MODE_BITSIZE (lnmode);
3849 lnbitpos = first_bit & ~ (lnbitsize - 1);
3850 lntype = type_for_size (lnbitsize, 1);
3851 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
3853 if (BYTES_BIG_ENDIAN)
3855 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
3856 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
3859 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
3860 size_int (xll_bitpos), 0);
3861 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
3862 size_int (xrl_bitpos), 0);
3866 l_const = convert (lntype, l_const);
3867 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
3868 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
3869 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
3870 fold (build1 (BIT_NOT_EXPR,
3874 warning ("comparison is always %d", wanted_code == NE_EXPR);
3876 return convert (truth_type,
3877 wanted_code == NE_EXPR
3878 ? integer_one_node : integer_zero_node);
3883 r_const = convert (lntype, r_const);
3884 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
3885 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
3886 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
3887 fold (build1 (BIT_NOT_EXPR,
3891 warning ("comparison is always %d", wanted_code == NE_EXPR);
3893 return convert (truth_type,
3894 wanted_code == NE_EXPR
3895 ? integer_one_node : integer_zero_node);
3899 /* If the right sides are not constant, do the same for it. Also,
3900 disallow this optimization if a size or signedness mismatch occurs
3901 between the left and right sides. */
3904 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
3905 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
3906 /* Make sure the two fields on the right
3907 correspond to the left without being swapped. */
3908 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
3911 first_bit = MIN (lr_bitpos, rr_bitpos);
3912 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
3913 rnmode = get_best_mode (end_bit - first_bit, first_bit,
3914 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
3916 if (rnmode == VOIDmode)
3919 rnbitsize = GET_MODE_BITSIZE (rnmode);
3920 rnbitpos = first_bit & ~ (rnbitsize - 1);
3921 rntype = type_for_size (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 (rntype, lr_mask),
3931 size_int (xlr_bitpos), 0);
3932 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, 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 operands are the
3937 same size and the bits being compared are in the same position
3938 then 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 (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
3944 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
3945 ll_unsignedp || rl_unsignedp);
3946 if (! all_ones_mask_p (ll_mask, lnbitsize))
3947 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
3949 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
3950 lr_unsignedp || rr_unsignedp);
3951 if (! all_ones_mask_p (lr_mask, rnbitsize))
3952 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_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.
3961 Note that we still must mask the lhs/rhs expressions. Furthermore,
3962 the mask must be shifted to account for the shift done by
3963 make_bit_field_ref. */
3964 if ((ll_bitsize + ll_bitpos == rl_bitpos
3965 && lr_bitsize + lr_bitpos == rr_bitpos)
3966 || (ll_bitpos == rl_bitpos + rl_bitsize
3967 && lr_bitpos == rr_bitpos + rr_bitsize))
3971 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
3972 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
3973 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
3974 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
3976 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
3977 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
3978 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
3979 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
3981 /* Convert to the smaller type before masking out unwanted bits. */
3983 if (lntype != rntype)
3985 if (lnbitsize > rnbitsize)
3987 lhs = convert (rntype, lhs);
3988 ll_mask = convert (rntype, ll_mask);
3991 else if (lnbitsize < rnbitsize)
3993 rhs = convert (lntype, rhs);
3994 lr_mask = convert (lntype, lr_mask);
3999 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4000 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
4002 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4003 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
4005 return build (wanted_code, truth_type, lhs, rhs);
4011 /* Handle the case of comparisons with constants. If there is something in
4012 common between the masks, those bits of the constants must be the same.
4013 If not, the condition is always false. Test for this to avoid generating
4014 incorrect code below. */
4015 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4016 if (! integer_zerop (result)
4017 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4018 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4020 if (wanted_code == NE_EXPR)
4022 warning ("`or' of unmatched not-equal tests is always 1");
4023 return convert (truth_type, integer_one_node);
4027 warning ("`and' of mutually exclusive equal-tests is always 0");
4028 return convert (truth_type, integer_zero_node);
4032 /* Construct the expression we will return. First get the component
4033 reference we will make. Unless the mask is all ones the width of
4034 that field, perform the mask operation. Then compare with the
4036 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4037 ll_unsignedp || rl_unsignedp);
4039 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4040 if (! all_ones_mask_p (ll_mask, lnbitsize))
4041 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
4043 return build (wanted_code, truth_type, result,
4044 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4047 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4048 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4049 that we may sometimes modify the tree. */
4052 strip_compound_expr (t, s)
4056 enum tree_code code = TREE_CODE (t);
4058 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4059 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4060 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4061 return TREE_OPERAND (t, 1);
4063 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4064 don't bother handling any other types. */
4065 else if (code == COND_EXPR)
4067 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4068 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4069 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4071 else if (TREE_CODE_CLASS (code) == '1')
4072 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4073 else if (TREE_CODE_CLASS (code) == '<'
4074 || TREE_CODE_CLASS (code) == '2')
4076 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4077 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4083 /* Return a node which has the indicated constant VALUE (either 0 or
4084 1), and is of the indicated TYPE. */
4087 constant_boolean_node (value, type)
4091 if (type == integer_type_node)
4092 return value ? integer_one_node : integer_zero_node;
4093 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4094 return truthvalue_conversion (value ? integer_one_node :
4098 tree t = build_int_2 (value, 0);
4099 TREE_TYPE (t) = type;
4104 /* Utility function for the following routine, to see how complex a nesting of
4105 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4106 we don't care (to avoid spending too much time on complex expressions.). */
4109 count_cond (expr, lim)
4115 if (TREE_CODE (expr) != COND_EXPR)
4120 true = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4121 false = count_cond (TREE_OPERAND (expr, 2), lim - 1 - true);
4122 return MIN (lim, 1 + true + false);
4125 /* Perform constant folding and related simplification of EXPR.
4126 The related simplifications include x*1 => x, x*0 => 0, etc.,
4127 and application of the associative law.
4128 NOP_EXPR conversions may be removed freely (as long as we
4129 are careful not to change the C type of the overall expression)
4130 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4131 but we can constant-fold them if they have constant operands. */
4137 register tree t = expr;
4138 tree t1 = NULL_TREE;
4140 tree type = TREE_TYPE (expr);
4141 register tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4142 register enum tree_code code = TREE_CODE (t);
4146 /* WINS will be nonzero when the switch is done
4147 if all operands are constant. */
4151 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4152 Likewise for a SAVE_EXPR that's already been evaluated. */
4153 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t)) != 0)
4156 /* Return right away if already constant. */
4157 if (TREE_CONSTANT (t))
4159 if (code == CONST_DECL)
4160 return DECL_INITIAL (t);
4164 #ifdef MAX_INTEGER_COMPUTATION_MODE
4165 check_max_integer_computation_mode (expr);
4168 kind = TREE_CODE_CLASS (code);
4169 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4173 /* Special case for conversion ops that can have fixed point args. */
4174 arg0 = TREE_OPERAND (t, 0);
4176 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4178 STRIP_TYPE_NOPS (arg0);
4180 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4181 subop = TREE_REALPART (arg0);
4185 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4186 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4187 && TREE_CODE (subop) != REAL_CST
4188 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4190 /* Note that TREE_CONSTANT isn't enough:
4191 static var addresses are constant but we can't
4192 do arithmetic on them. */
4195 else if (kind == 'e' || kind == '<'
4196 || kind == '1' || kind == '2' || kind == 'r')
4198 register int len = tree_code_length[(int) code];
4200 for (i = 0; i < len; i++)
4202 tree op = TREE_OPERAND (t, i);
4206 continue; /* Valid for CALL_EXPR, at least. */
4208 if (kind == '<' || code == RSHIFT_EXPR)
4210 /* Signedness matters here. Perhaps we can refine this
4212 STRIP_TYPE_NOPS (op);
4216 /* Strip any conversions that don't change the mode. */
4220 if (TREE_CODE (op) == COMPLEX_CST)
4221 subop = TREE_REALPART (op);
4225 if (TREE_CODE (subop) != INTEGER_CST
4226 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4227 && TREE_CODE (subop) != REAL_CST
4228 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4230 /* Note that TREE_CONSTANT isn't enough:
4231 static var addresses are constant but we can't
4232 do arithmetic on them. */
4242 /* If this is a commutative operation, and ARG0 is a constant, move it
4243 to ARG1 to reduce the number of tests below. */
4244 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
4245 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
4246 || code == BIT_AND_EXPR)
4247 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
4249 tem = arg0; arg0 = arg1; arg1 = tem;
4251 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
4252 TREE_OPERAND (t, 1) = tem;
4255 /* Now WINS is set as described above,
4256 ARG0 is the first operand of EXPR,
4257 and ARG1 is the second operand (if it has more than one operand).
4259 First check for cases where an arithmetic operation is applied to a
4260 compound, conditional, or comparison operation. Push the arithmetic
4261 operation inside the compound or conditional to see if any folding
4262 can then be done. Convert comparison to conditional for this purpose.
4263 The also optimizes non-constant cases that used to be done in
4266 Before we do that, see if this is a BIT_AND_EXPR or a BIT_OR_EXPR,
4267 one of the operands is a comparison and the other is a comparison, a
4268 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
4269 code below would make the expression more complex. Change it to a
4270 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
4271 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
4273 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
4274 || code == EQ_EXPR || code == NE_EXPR)
4275 && ((truth_value_p (TREE_CODE (arg0))
4276 && (truth_value_p (TREE_CODE (arg1))
4277 || (TREE_CODE (arg1) == BIT_AND_EXPR
4278 && integer_onep (TREE_OPERAND (arg1, 1)))))
4279 || (truth_value_p (TREE_CODE (arg1))
4280 && (truth_value_p (TREE_CODE (arg0))
4281 || (TREE_CODE (arg0) == BIT_AND_EXPR
4282 && integer_onep (TREE_OPERAND (arg0, 1)))))))
4284 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
4285 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
4289 if (code == EQ_EXPR)
4290 t = invert_truthvalue (t);
4295 if (TREE_CODE_CLASS (code) == '1')
4297 if (TREE_CODE (arg0) == COMPOUND_EXPR)
4298 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4299 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
4300 else if (TREE_CODE (arg0) == COND_EXPR)
4302 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
4303 fold (build1 (code, type, TREE_OPERAND (arg0, 1))),
4304 fold (build1 (code, type, TREE_OPERAND (arg0, 2)))));
4306 /* If this was a conversion, and all we did was to move into
4307 inside the COND_EXPR, bring it back out. But leave it if
4308 it is a conversion from integer to integer and the
4309 result precision is no wider than a word since such a
4310 conversion is cheap and may be optimized away by combine,
4311 while it couldn't if it were outside the COND_EXPR. Then return
4312 so we don't get into an infinite recursion loop taking the
4313 conversion out and then back in. */
4315 if ((code == NOP_EXPR || code == CONVERT_EXPR
4316 || code == NON_LVALUE_EXPR)
4317 && TREE_CODE (t) == COND_EXPR
4318 && TREE_CODE (TREE_OPERAND (t, 1)) == code
4319 && TREE_CODE (TREE_OPERAND (t, 2)) == code
4320 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
4321 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
4322 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
4323 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0)))
4324 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
4325 t = build1 (code, type,
4327 TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0)),
4328 TREE_OPERAND (t, 0),
4329 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
4330 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
4333 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
4334 return fold (build (COND_EXPR, type, arg0,
4335 fold (build1 (code, type, integer_one_node)),
4336 fold (build1 (code, type, integer_zero_node))));
4338 else if (TREE_CODE_CLASS (code) == '2'
4339 || TREE_CODE_CLASS (code) == '<')
4341 if (TREE_CODE (arg1) == COMPOUND_EXPR)
4342 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4343 fold (build (code, type,
4344 arg0, TREE_OPERAND (arg1, 1))));
4345 else if ((TREE_CODE (arg1) == COND_EXPR
4346 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
4347 && TREE_CODE_CLASS (code) != '<'))
4348 && (TREE_CODE (arg0) != COND_EXPR
4349 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4350 && (! TREE_SIDE_EFFECTS (arg0)
4351 || (current_function_decl != 0
4352 && ! contains_placeholder_p (arg0))))
4354 tree test, true_value, false_value;
4355 tree lhs = 0, rhs = 0;
4357 if (TREE_CODE (arg1) == COND_EXPR)
4359 test = TREE_OPERAND (arg1, 0);
4360 true_value = TREE_OPERAND (arg1, 1);
4361 false_value = TREE_OPERAND (arg1, 2);
4365 tree testtype = TREE_TYPE (arg1);
4367 true_value = convert (testtype, integer_one_node);
4368 false_value = convert (testtype, integer_zero_node);
4371 /* If ARG0 is complex we want to make sure we only evaluate
4372 it once. Though this is only required if it is volatile, it
4373 might be more efficient even if it is not. However, if we
4374 succeed in folding one part to a constant, we do not need
4375 to make this SAVE_EXPR. Since we do this optimization
4376 primarily to see if we do end up with constant and this
4377 SAVE_EXPR interferes with later optimizations, suppressing
4378 it when we can is important.
4380 If we are not in a function, we can't make a SAVE_EXPR, so don't
4381 try to do so. Don't try to see if the result is a constant
4382 if an arm is a COND_EXPR since we get exponential behavior
4385 if (TREE_CODE (arg0) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4386 && current_function_decl != 0
4387 && ((TREE_CODE (arg0) != VAR_DECL
4388 && TREE_CODE (arg0) != PARM_DECL)
4389 || TREE_SIDE_EFFECTS (arg0)))
4391 if (TREE_CODE (true_value) != COND_EXPR)
4392 lhs = fold (build (code, type, arg0, true_value));
4394 if (TREE_CODE (false_value) != COND_EXPR)
4395 rhs = fold (build (code, type, arg0, false_value));
4397 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4398 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4399 arg0 = save_expr (arg0), lhs = rhs = 0;
4403 lhs = fold (build (code, type, arg0, true_value));
4405 rhs = fold (build (code, type, arg0, false_value));
4407 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4409 if (TREE_CODE (arg0) == SAVE_EXPR)
4410 return build (COMPOUND_EXPR, type,
4411 convert (void_type_node, arg0),
4412 strip_compound_expr (test, arg0));
4414 return convert (type, test);
4417 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
4418 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4419 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4420 else if ((TREE_CODE (arg0) == COND_EXPR
4421 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
4422 && TREE_CODE_CLASS (code) != '<'))
4423 && (TREE_CODE (arg1) != COND_EXPR
4424 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
4425 && (! TREE_SIDE_EFFECTS (arg1)
4426 || (current_function_decl != 0
4427 && ! contains_placeholder_p (arg1))))
4429 tree test, true_value, false_value;
4430 tree lhs = 0, rhs = 0;
4432 if (TREE_CODE (arg0) == COND_EXPR)
4434 test = TREE_OPERAND (arg0, 0);
4435 true_value = TREE_OPERAND (arg0, 1);
4436 false_value = TREE_OPERAND (arg0, 2);
4440 tree testtype = TREE_TYPE (arg0);
4442 true_value = convert (testtype, integer_one_node);
4443 false_value = convert (testtype, integer_zero_node);
4446 if (TREE_CODE (arg1) != SAVE_EXPR && ! TREE_CONSTANT (arg0)
4447 && current_function_decl != 0
4448 && ((TREE_CODE (arg1) != VAR_DECL
4449 && TREE_CODE (arg1) != PARM_DECL)
4450 || TREE_SIDE_EFFECTS (arg1)))
4452 if (TREE_CODE (true_value) != COND_EXPR)
4453 lhs = fold (build (code, type, true_value, arg1));
4455 if (TREE_CODE (false_value) != COND_EXPR)
4456 rhs = fold (build (code, type, false_value, arg1));
4458 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4459 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4460 arg1 = save_expr (arg1), lhs = rhs = 0;
4464 lhs = fold (build (code, type, true_value, arg1));
4467 rhs = fold (build (code, type, false_value, arg1));
4469 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4470 if (TREE_CODE (arg1) == SAVE_EXPR)
4471 return build (COMPOUND_EXPR, type,
4472 convert (void_type_node, arg1),
4473 strip_compound_expr (test, arg1));
4475 return convert (type, test);
4478 else if (TREE_CODE_CLASS (code) == '<'
4479 && TREE_CODE (arg0) == COMPOUND_EXPR)
4480 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
4481 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
4482 else if (TREE_CODE_CLASS (code) == '<'
4483 && TREE_CODE (arg1) == COMPOUND_EXPR)
4484 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
4485 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
4497 return fold (DECL_INITIAL (t));
4502 case FIX_TRUNC_EXPR:
4503 /* Other kinds of FIX are not handled properly by fold_convert. */
4505 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
4506 return TREE_OPERAND (t, 0);
4508 /* Handle cases of two conversions in a row. */
4509 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
4510 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
4512 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4513 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
4514 tree final_type = TREE_TYPE (t);
4515 int inside_int = INTEGRAL_TYPE_P (inside_type);
4516 int inside_ptr = POINTER_TYPE_P (inside_type);
4517 int inside_float = FLOAT_TYPE_P (inside_type);
4518 int inside_prec = TYPE_PRECISION (inside_type);
4519 int inside_unsignedp = TREE_UNSIGNED (inside_type);
4520 int inter_int = INTEGRAL_TYPE_P (inter_type);
4521 int inter_ptr = POINTER_TYPE_P (inter_type);
4522 int inter_float = FLOAT_TYPE_P (inter_type);
4523 int inter_prec = TYPE_PRECISION (inter_type);
4524 int inter_unsignedp = TREE_UNSIGNED (inter_type);
4525 int final_int = INTEGRAL_TYPE_P (final_type);
4526 int final_ptr = POINTER_TYPE_P (final_type);
4527 int final_float = FLOAT_TYPE_P (final_type);
4528 int final_prec = TYPE_PRECISION (final_type);
4529 int final_unsignedp = TREE_UNSIGNED (final_type);
4531 /* In addition to the cases of two conversions in a row
4532 handled below, if we are converting something to its own
4533 type via an object of identical or wider precision, neither
4534 conversion is needed. */
4535 if (inside_type == final_type
4536 && ((inter_int && final_int) || (inter_float && final_float))
4537 && inter_prec >= final_prec)
4538 return TREE_OPERAND (TREE_OPERAND (t, 0), 0);
4540 /* Likewise, if the intermediate and final types are either both
4541 float or both integer, we don't need the middle conversion if
4542 it is wider than the final type and doesn't change the signedness
4543 (for integers). Avoid this if the final type is a pointer
4544 since then we sometimes need the inner conversion. Likewise if
4545 the outer has a precision not equal to the size of its mode. */
4546 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
4547 || (inter_float && inside_float))
4548 && inter_prec >= inside_prec
4549 && (inter_float || inter_unsignedp == inside_unsignedp)
4550 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
4551 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
4553 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4555 /* If we have a sign-extension of a zero-extended value, we can
4556 replace that by a single zero-extension. */
4557 if (inside_int && inter_int && final_int
4558 && inside_prec < inter_prec && inter_prec < final_prec
4559 && inside_unsignedp && !inter_unsignedp)
4560 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4562 /* Two conversions in a row are not needed unless:
4563 - some conversion is floating-point (overstrict for now), or
4564 - the intermediate type is narrower than both initial and
4566 - the intermediate type and innermost type differ in signedness,
4567 and the outermost type is wider than the intermediate, or
4568 - the initial type is a pointer type and the precisions of the
4569 intermediate and final types differ, or
4570 - the final type is a pointer type and the precisions of the
4571 initial and intermediate types differ. */
4572 if (! inside_float && ! inter_float && ! final_float
4573 && (inter_prec > inside_prec || inter_prec > final_prec)
4574 && ! (inside_int && inter_int
4575 && inter_unsignedp != inside_unsignedp
4576 && inter_prec < final_prec)
4577 && ((inter_unsignedp && inter_prec > inside_prec)
4578 == (final_unsignedp && final_prec > inter_prec))
4579 && ! (inside_ptr && inter_prec != final_prec)
4580 && ! (final_ptr && inside_prec != inter_prec)
4581 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
4582 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
4584 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
4587 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
4588 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
4589 /* Detect assigning a bitfield. */
4590 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
4591 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
4593 /* Don't leave an assignment inside a conversion
4594 unless assigning a bitfield. */
4595 tree prev = TREE_OPERAND (t, 0);
4596 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
4597 /* First do the assignment, then return converted constant. */
4598 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
4604 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
4607 return fold_convert (t, arg0);
4609 #if 0 /* This loses on &"foo"[0]. */
4614 /* Fold an expression like: "foo"[2] */
4615 if (TREE_CODE (arg0) == STRING_CST
4616 && TREE_CODE (arg1) == INTEGER_CST
4617 && !TREE_INT_CST_HIGH (arg1)
4618 && (i = TREE_INT_CST_LOW (arg1)) < TREE_STRING_LENGTH (arg0))
4620 t = build_int_2 (TREE_STRING_POINTER (arg0)[i], 0);
4621 TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (arg0));
4622 force_fit_type (t, 0);
4629 if (TREE_CODE (arg0) == CONSTRUCTOR)
4631 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
4638 TREE_CONSTANT (t) = wins;
4644 if (TREE_CODE (arg0) == INTEGER_CST)
4646 HOST_WIDE_INT low, high;
4647 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
4648 TREE_INT_CST_HIGH (arg0),
4650 t = build_int_2 (low, high);
4651 TREE_TYPE (t) = type;
4653 = (TREE_OVERFLOW (arg0)
4654 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
4655 TREE_CONSTANT_OVERFLOW (t)
4656 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
4658 else if (TREE_CODE (arg0) == REAL_CST)
4659 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
4661 else if (TREE_CODE (arg0) == NEGATE_EXPR)
4662 return TREE_OPERAND (arg0, 0);
4664 /* Convert - (a - b) to (b - a) for non-floating-point. */
4665 else if (TREE_CODE (arg0) == MINUS_EXPR && ! FLOAT_TYPE_P (type))
4666 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
4667 TREE_OPERAND (arg0, 0));
4674 if (TREE_CODE (arg0) == INTEGER_CST)
4676 if (! TREE_UNSIGNED (type)
4677 && TREE_INT_CST_HIGH (arg0) < 0)
4679 HOST_WIDE_INT low, high;
4680 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
4681 TREE_INT_CST_HIGH (arg0),
4683 t = build_int_2 (low, high);
4684 TREE_TYPE (t) = type;
4686 = (TREE_OVERFLOW (arg0)
4687 | force_fit_type (t, overflow));
4688 TREE_CONSTANT_OVERFLOW (t)
4689 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
4692 else if (TREE_CODE (arg0) == REAL_CST)
4694 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
4695 t = build_real (type,
4696 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
4699 else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR)
4700 return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
4704 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
4706 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
4707 return build (COMPLEX_EXPR, TREE_TYPE (arg0),
4708 TREE_OPERAND (arg0, 0),
4709 fold (build1 (NEGATE_EXPR,
4710 TREE_TYPE (TREE_TYPE (arg0)),
4711 TREE_OPERAND (arg0, 1))));
4712 else if (TREE_CODE (arg0) == COMPLEX_CST)
4713 return build_complex (type, TREE_OPERAND (arg0, 0),
4714 fold (build1 (NEGATE_EXPR,
4715 TREE_TYPE (TREE_TYPE (arg0)),
4716 TREE_OPERAND (arg0, 1))));
4717 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
4718 return fold (build (TREE_CODE (arg0), type,
4719 fold (build1 (CONJ_EXPR, type,
4720 TREE_OPERAND (arg0, 0))),
4721 fold (build1 (CONJ_EXPR,
4722 type, TREE_OPERAND (arg0, 1)))));
4723 else if (TREE_CODE (arg0) == CONJ_EXPR)
4724 return TREE_OPERAND (arg0, 0);
4730 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
4731 ~ TREE_INT_CST_HIGH (arg0));
4732 TREE_TYPE (t) = type;
4733 force_fit_type (t, 0);
4734 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
4735 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
4737 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
4738 return TREE_OPERAND (arg0, 0);
4742 /* A + (-B) -> A - B */
4743 if (TREE_CODE (arg1) == NEGATE_EXPR)
4744 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
4745 else if (! FLOAT_TYPE_P (type))
4747 if (integer_zerop (arg1))
4748 return non_lvalue (convert (type, arg0));
4750 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
4751 with a constant, and the two constants have no bits in common,
4752 we should treat this as a BIT_IOR_EXPR since this may produce more
4754 if (TREE_CODE (arg0) == BIT_AND_EXPR
4755 && TREE_CODE (arg1) == BIT_AND_EXPR
4756 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
4757 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
4758 && integer_zerop (const_binop (BIT_AND_EXPR,
4759 TREE_OPERAND (arg0, 1),
4760 TREE_OPERAND (arg1, 1), 0)))
4762 code = BIT_IOR_EXPR;
4766 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
4767 (plus (plus (mult) (mult)) (foo)) so that we can
4768 take advantage of the factoring cases below. */
4769 if ((TREE_CODE (arg0) == PLUS_EXPR
4770 && TREE_CODE (arg1) == MULT_EXPR)
4771 || (TREE_CODE (arg1) == PLUS_EXPR
4772 && TREE_CODE (arg0) == MULT_EXPR))
4774 tree parg0, parg1, parg, marg;
4776 if (TREE_CODE (arg0) == PLUS_EXPR)
4777 parg = arg0, marg = arg1;
4779 parg = arg1, marg = arg0;
4780 parg0 = TREE_OPERAND (parg, 0);
4781 parg1 = TREE_OPERAND (parg, 1);
4785 if (TREE_CODE (parg0) == MULT_EXPR
4786 && TREE_CODE (parg1) != MULT_EXPR)
4787 return fold (build (PLUS_EXPR, type,
4788 fold (build (PLUS_EXPR, type, parg0, marg)),
4790 if (TREE_CODE (parg0) != MULT_EXPR
4791 && TREE_CODE (parg1) == MULT_EXPR)
4792 return fold (build (PLUS_EXPR, type,
4793 fold (build (PLUS_EXPR, type, parg1, marg)),
4797 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
4799 tree arg00, arg01, arg10, arg11;
4800 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
4802 /* (A * C) + (B * C) -> (A+B) * C.
4803 We are most concerned about the case where C is a constant,
4804 but other combinations show up during loop reduction. Since
4805 it is not difficult, try all four possibilities. */
4807 arg00 = TREE_OPERAND (arg0, 0);
4808 arg01 = TREE_OPERAND (arg0, 1);
4809 arg10 = TREE_OPERAND (arg1, 0);
4810 arg11 = TREE_OPERAND (arg1, 1);
4813 if (operand_equal_p (arg01, arg11, 0))
4814 same = arg01, alt0 = arg00, alt1 = arg10;
4815 else if (operand_equal_p (arg00, arg10, 0))
4816 same = arg00, alt0 = arg01, alt1 = arg11;
4817 else if (operand_equal_p (arg00, arg11, 0))
4818 same = arg00, alt0 = arg01, alt1 = arg10;
4819 else if (operand_equal_p (arg01, arg10, 0))
4820 same = arg01, alt0 = arg00, alt1 = arg11;
4822 /* No identical multiplicands; see if we can find a common
4823 power-of-two factor in non-power-of-two multiplies. This
4824 can help in multi-dimensional array access. */
4825 else if (TREE_CODE (arg01) == INTEGER_CST
4826 && TREE_CODE (arg11) == INTEGER_CST
4827 && TREE_INT_CST_HIGH (arg01) == 0
4828 && TREE_INT_CST_HIGH (arg11) == 0)
4830 HOST_WIDE_INT int01, int11, tmp;
4831 int01 = TREE_INT_CST_LOW (arg01);
4832 int11 = TREE_INT_CST_LOW (arg11);
4834 /* Move min of absolute values to int11. */
4835 if ((int01 >= 0 ? int01 : -int01)
4836 < (int11 >= 0 ? int11 : -int11))
4838 tmp = int01, int01 = int11, int11 = tmp;
4839 alt0 = arg00, arg00 = arg10, arg10 = alt0;
4840 alt0 = arg01, arg01 = arg11, arg11 = alt0;
4843 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
4845 alt0 = fold (build (MULT_EXPR, type, arg00,
4846 build_int_2 (int01 / int11, 0)));
4853 return fold (build (MULT_EXPR, type,
4854 fold (build (PLUS_EXPR, type, alt0, alt1)),
4858 /* In IEEE floating point, x+0 may not equal x. */
4859 else if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
4861 && real_zerop (arg1))
4862 return non_lvalue (convert (type, arg0));
4864 /* In most languages, can't associate operations on floats
4865 through parentheses. Rather than remember where the parentheses
4866 were, we don't associate floats at all. It shouldn't matter much.
4867 However, associating multiplications is only very slightly
4868 inaccurate, so do that if -ffast-math is specified. */
4869 if (FLOAT_TYPE_P (type)
4870 && ! (flag_fast_math && code == MULT_EXPR))
4873 /* The varsign == -1 cases happen only for addition and subtraction.
4874 It says that the arg that was split was really CON minus VAR.
4875 The rest of the code applies to all associative operations. */
4881 if (split_tree (arg0, code, &var, &con, &varsign))
4885 /* EXPR is (CON-VAR) +- ARG1. */
4886 /* If it is + and VAR==ARG1, return just CONST. */
4887 if (code == PLUS_EXPR && operand_equal_p (var, arg1, 0))
4888 return convert (TREE_TYPE (t), con);
4890 /* If ARG0 is a constant, don't change things around;
4891 instead keep all the constant computations together. */
4893 if (TREE_CONSTANT (arg0))
4896 /* Otherwise return (CON +- ARG1) - VAR. */
4897 t = build (MINUS_EXPR, type,
4898 fold (build (code, type, con, arg1)), var);
4902 /* EXPR is (VAR+CON) +- ARG1. */
4903 /* If it is - and VAR==ARG1, return just CONST. */
4904 if (code == MINUS_EXPR && operand_equal_p (var, arg1, 0))
4905 return convert (TREE_TYPE (t), con);
4907 /* If ARG0 is a constant, don't change things around;
4908 instead keep all the constant computations together. */
4910 if (TREE_CONSTANT (arg0))
4913 /* Otherwise return VAR +- (ARG1 +- CON). */
4914 tem = fold (build (code, type, arg1, con));
4915 t = build (code, type, var, tem);
4917 if (integer_zerop (tem)
4918 && (code == PLUS_EXPR || code == MINUS_EXPR))
4919 return convert (type, var);
4920 /* If we have x +/- (c - d) [c an explicit integer]
4921 change it to x -/+ (d - c) since if d is relocatable
4922 then the latter can be a single immediate insn
4923 and the former cannot. */
4924 if (TREE_CODE (tem) == MINUS_EXPR
4925 && TREE_CODE (TREE_OPERAND (tem, 0)) == INTEGER_CST)
4927 tree tem1 = TREE_OPERAND (tem, 1);
4928 TREE_OPERAND (tem, 1) = TREE_OPERAND (tem, 0);
4929 TREE_OPERAND (tem, 0) = tem1;
4931 (code == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR));
4937 if (split_tree (arg1, code, &var, &con, &varsign))
4939 if (TREE_CONSTANT (arg1))
4944 (code == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR));
4946 /* EXPR is ARG0 +- (CON +- VAR). */
4947 if (TREE_CODE (t) == MINUS_EXPR
4948 && operand_equal_p (var, arg0, 0))
4950 /* If VAR and ARG0 cancel, return just CON or -CON. */
4951 if (code == PLUS_EXPR)
4952 return convert (TREE_TYPE (t), con);
4953 return fold (build1 (NEGATE_EXPR, TREE_TYPE (t),
4954 convert (TREE_TYPE (t), con)));
4957 t = build (TREE_CODE (t), type,
4958 fold (build (code, TREE_TYPE (t), arg0, con)), var);
4960 if (integer_zerop (TREE_OPERAND (t, 0))
4961 && TREE_CODE (t) == PLUS_EXPR)
4962 return convert (TREE_TYPE (t), var);
4967 #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
4968 if (TREE_CODE (arg1) == REAL_CST)
4970 #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
4972 t1 = const_binop (code, arg0, arg1, 0);
4973 if (t1 != NULL_TREE)
4975 /* The return value should always have
4976 the same type as the original expression. */
4977 if (TREE_TYPE (t1) != TREE_TYPE (t))
4978 t1 = convert (TREE_TYPE (t), t1);
4985 if (! FLOAT_TYPE_P (type))
4987 if (! wins && integer_zerop (arg0))
4988 return build1 (NEGATE_EXPR, type, arg1);
4989 if (integer_zerop (arg1))
4990 return non_lvalue (convert (type, arg0));
4992 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
4993 about the case where C is a constant, just try one of the
4994 four possibilities. */
4996 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
4997 && operand_equal_p (TREE_OPERAND (arg0, 1),
4998 TREE_OPERAND (arg1, 1), 0))
4999 return fold (build (MULT_EXPR, type,
5000 fold (build (MINUS_EXPR, type,
5001 TREE_OPERAND (arg0, 0),
5002 TREE_OPERAND (arg1, 0))),
5003 TREE_OPERAND (arg0, 1)));
5005 /* Convert A - (-B) to A + B. */
5006 else if (TREE_CODE (arg1) == NEGATE_EXPR)
5007 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5009 else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5012 /* Except with IEEE floating point, 0-x equals -x. */
5013 if (! wins && real_zerop (arg0))
5014 return build1 (NEGATE_EXPR, type, arg1);
5015 /* Except with IEEE floating point, x-0 equals x. */
5016 if (real_zerop (arg1))
5017 return non_lvalue (convert (type, arg0));
5020 /* Fold &x - &x. This can happen from &x.foo - &x.
5021 This is unsafe for certain floats even in non-IEEE formats.
5022 In IEEE, it is unsafe because it does wrong for NaNs.
5023 Also note that operand_equal_p is always false if an operand
5026 if ((! FLOAT_TYPE_P (type) || flag_fast_math)
5027 && operand_equal_p (arg0, arg1, 0))
5028 return convert (type, integer_zero_node);
5033 if (! FLOAT_TYPE_P (type))
5035 if (integer_zerop (arg1))
5036 return omit_one_operand (type, arg1, arg0);
5037 if (integer_onep (arg1))
5038 return non_lvalue (convert (type, arg0));
5040 /* ((A / C) * C) is A if the division is an
5041 EXACT_DIV_EXPR. Since C is normally a constant,
5042 just check for one of the four possibilities. */
5044 if (TREE_CODE (arg0) == EXACT_DIV_EXPR
5045 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
5046 return TREE_OPERAND (arg0, 0);
5048 /* (a * (1 << b)) is (a << b) */
5049 if (TREE_CODE (arg1) == LSHIFT_EXPR
5050 && integer_onep (TREE_OPERAND (arg1, 0)))
5051 return fold (build (LSHIFT_EXPR, type, arg0,
5052 TREE_OPERAND (arg1, 1)));
5053 if (TREE_CODE (arg0) == LSHIFT_EXPR
5054 && integer_onep (TREE_OPERAND (arg0, 0)))
5055 return fold (build (LSHIFT_EXPR, type, arg1,
5056 TREE_OPERAND (arg0, 1)));
5060 /* x*0 is 0, except for IEEE floating point. */
5061 if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
5063 && real_zerop (arg1))
5064 return omit_one_operand (type, arg1, arg0);
5065 /* In IEEE floating point, x*1 is not equivalent to x for snans.
5066 However, ANSI says we can drop signals,
5067 so we can do this anyway. */
5068 if (real_onep (arg1))
5069 return non_lvalue (convert (type, arg0));
5071 if (! wins && real_twop (arg1) && current_function_decl != 0
5072 && ! contains_placeholder_p (arg0))
5074 tree arg = save_expr (arg0);
5075 return build (PLUS_EXPR, type, arg, arg);
5083 register enum tree_code code0, code1;
5085 if (integer_all_onesp (arg1))
5086 return omit_one_operand (type, arg1, arg0);
5087 if (integer_zerop (arg1))
5088 return non_lvalue (convert (type, arg0));
5089 t1 = distribute_bit_expr (code, type, arg0, arg1);
5090 if (t1 != NULL_TREE)
5093 /* (A << C1) | (A >> C2) if A is unsigned and C1+C2 is the size of A
5094 is a rotate of A by C1 bits. */
5095 /* (A << B) | (A >> (Z - B)) if A is unsigned and Z is the size of A
5096 is a rotate of A by B bits. */
5098 code0 = TREE_CODE (arg0);
5099 code1 = TREE_CODE (arg1);
5100 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5101 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5102 && operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1,0), 0)
5103 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5105 register tree tree01, tree11;
5106 register enum tree_code code01, code11;
5108 tree01 = TREE_OPERAND (arg0, 1);
5109 tree11 = TREE_OPERAND (arg1, 1);
5110 STRIP_NOPS (tree01);
5111 STRIP_NOPS (tree11);
5112 code01 = TREE_CODE (tree01);
5113 code11 = TREE_CODE (tree11);
5114 if (code01 == INTEGER_CST
5115 && code11 == INTEGER_CST
5116 && TREE_INT_CST_HIGH (tree01) == 0
5117 && TREE_INT_CST_HIGH (tree11) == 0
5118 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5119 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5120 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5121 code0 == LSHIFT_EXPR ? tree01 : tree11);
5122 else if (code11 == MINUS_EXPR)
5124 tree tree110, tree111;
5125 tree110 = TREE_OPERAND (tree11, 0);
5126 tree111 = TREE_OPERAND (tree11, 1);
5127 STRIP_NOPS (tree110);
5128 STRIP_NOPS (tree111);
5129 if (TREE_CODE (tree110) == INTEGER_CST
5130 && TREE_INT_CST_HIGH (tree110) == 0
5131 && (TREE_INT_CST_LOW (tree110)
5132 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5133 && operand_equal_p (tree01, tree111, 0))
5134 return build ((code0 == LSHIFT_EXPR
5137 type, TREE_OPERAND (arg0, 0), tree01);
5139 else if (code01 == MINUS_EXPR)
5141 tree tree010, tree011;
5142 tree010 = TREE_OPERAND (tree01, 0);
5143 tree011 = TREE_OPERAND (tree01, 1);
5144 STRIP_NOPS (tree010);
5145 STRIP_NOPS (tree011);
5146 if (TREE_CODE (tree010) == INTEGER_CST
5147 && TREE_INT_CST_HIGH (tree010) == 0
5148 && (TREE_INT_CST_LOW (tree010)
5149 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5150 && operand_equal_p (tree11, tree011, 0))
5151 return build ((code0 != LSHIFT_EXPR
5154 type, TREE_OPERAND (arg0, 0), tree11);
5162 if (integer_zerop (arg1))
5163 return non_lvalue (convert (type, arg0));
5164 if (integer_all_onesp (arg1))
5165 return fold (build1 (BIT_NOT_EXPR, type, arg0));
5170 if (integer_all_onesp (arg1))
5171 return non_lvalue (convert (type, arg0));
5172 if (integer_zerop (arg1))
5173 return omit_one_operand (type, arg1, arg0);
5174 t1 = distribute_bit_expr (code, type, arg0, arg1);
5175 if (t1 != NULL_TREE)
5177 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5178 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == NOP_EXPR
5179 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0))))
5181 int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0)));
5182 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5183 && (~TREE_INT_CST_LOW (arg0)
5184 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5185 return build1 (NOP_EXPR, type, TREE_OPERAND (arg1, 0));
5187 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
5188 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5190 int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
5191 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
5192 && (~TREE_INT_CST_LOW (arg1)
5193 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
5194 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
5198 case BIT_ANDTC_EXPR:
5199 if (integer_all_onesp (arg0))
5200 return non_lvalue (convert (type, arg1));
5201 if (integer_zerop (arg0))
5202 return omit_one_operand (type, arg0, arg1);
5203 if (TREE_CODE (arg1) == INTEGER_CST)
5205 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
5206 code = BIT_AND_EXPR;
5212 /* In most cases, do nothing with a divide by zero. */
5213 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5214 #ifndef REAL_INFINITY
5215 if (TREE_CODE (arg1) == REAL_CST && real_zerop (arg1))
5218 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5220 /* In IEEE floating point, x/1 is not equivalent to x for snans.
5221 However, ANSI says we can drop signals, so we can do this anyway. */
5222 if (real_onep (arg1))
5223 return non_lvalue (convert (type, arg0));
5225 /* If ARG1 is a constant, we can convert this to a multiply by the
5226 reciprocal. This does not have the same rounding properties,
5227 so only do this if -ffast-math. We can actually always safely
5228 do it if ARG1 is a power of two, but it's hard to tell if it is
5229 or not in a portable manner. */
5230 if (TREE_CODE (arg1) == REAL_CST)
5233 && 0 != (tem = const_binop (code, build_real (type, dconst1),
5235 return fold (build (MULT_EXPR, type, arg0, tem));
5236 /* Find the reciprocal if optimizing and the result is exact. */
5240 r = TREE_REAL_CST (arg1);
5241 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
5243 tem = build_real (type, r);
5244 return fold (build (MULT_EXPR, type, arg0, tem));
5250 case TRUNC_DIV_EXPR:
5251 case ROUND_DIV_EXPR:
5252 case FLOOR_DIV_EXPR:
5254 case EXACT_DIV_EXPR:
5255 if (integer_onep (arg1))
5256 return non_lvalue (convert (type, arg0));
5257 if (integer_zerop (arg1))
5260 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
5261 operation, EXACT_DIV_EXPR.
5263 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
5264 At one time others generated faster code, it's not clear if they do
5265 after the last round to changes to the DIV code in expmed.c. */
5266 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
5267 && multiple_of_p (type, arg0, arg1))
5268 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
5270 /* If we have ((a / C1) / C2) where both division are the same type, try
5271 to simplify. First see if C1 * C2 overflows or not. */
5272 if (TREE_CODE (arg0) == code && TREE_CODE (arg1) == INTEGER_CST
5273 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5277 new_divisor = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 1), arg1, 0);
5278 tem = const_binop (FLOOR_DIV_EXPR, new_divisor, arg1, 0);
5280 if (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) == TREE_INT_CST_LOW (tem)
5281 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == TREE_INT_CST_HIGH (tem))
5283 /* If no overflow, divide by C1*C2. */
5284 return fold (build (code, type, TREE_OPERAND (arg0, 0), new_divisor));
5288 /* Look for ((a * C1) / C3) or (((a * C1) + C2) / C3),
5289 where C1 % C3 == 0 or C3 % C1 == 0. We can simplify these
5290 expressions, which often appear in the offsets or sizes of
5291 objects with a varying size. Only deal with positive divisors
5292 and multiplicands. If C2 is negative, we must have C2 % C3 == 0.
5294 Look for NOPs and SAVE_EXPRs inside. */
5296 if (TREE_CODE (arg1) == INTEGER_CST
5297 && tree_int_cst_sgn (arg1) >= 0)
5299 int have_save_expr = 0;
5300 tree c2 = integer_zero_node;
5303 if (TREE_CODE (xarg0) == SAVE_EXPR && SAVE_EXPR_RTL (xarg0) == 0)
5304 have_save_expr = 1, xarg0 = TREE_OPERAND (xarg0, 0);
5308 /* Look inside the dividend and simplify using EXACT_DIV_EXPR
5310 if (TREE_CODE (xarg0) == MULT_EXPR
5311 && multiple_of_p (type, TREE_OPERAND (xarg0, 0), arg1))
5315 t = fold (build (MULT_EXPR, type,
5316 fold (build (EXACT_DIV_EXPR, type,
5317 TREE_OPERAND (xarg0, 0), arg1)),
5318 TREE_OPERAND (xarg0, 1)));
5325 if (TREE_CODE (xarg0) == MULT_EXPR
5326 && multiple_of_p (type, TREE_OPERAND (xarg0, 1), arg1))
5330 t = fold (build (MULT_EXPR, type,
5331 fold (build (EXACT_DIV_EXPR, type,
5332 TREE_OPERAND (xarg0, 1), arg1)),
5333 TREE_OPERAND (xarg0, 0)));
5339 if (TREE_CODE (xarg0) == PLUS_EXPR
5340 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST)
5341 c2 = TREE_OPERAND (xarg0, 1), xarg0 = TREE_OPERAND (xarg0, 0);
5342 else if (TREE_CODE (xarg0) == MINUS_EXPR
5343 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5344 /* If we are doing this computation unsigned, the negate
5346 && ! TREE_UNSIGNED (type))
5348 c2 = fold (build1 (NEGATE_EXPR, type, TREE_OPERAND (xarg0, 1)));
5349 xarg0 = TREE_OPERAND (xarg0, 0);
5352 if (TREE_CODE (xarg0) == SAVE_EXPR && SAVE_EXPR_RTL (xarg0) == 0)
5353 have_save_expr = 1, xarg0 = TREE_OPERAND (xarg0, 0);
5357 if (TREE_CODE (xarg0) == MULT_EXPR
5358 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5359 && tree_int_cst_sgn (TREE_OPERAND (xarg0, 1)) >= 0
5360 && (integer_zerop (const_binop (TRUNC_MOD_EXPR,
5361 TREE_OPERAND (xarg0, 1), arg1, 1))
5362 || integer_zerop (const_binop (TRUNC_MOD_EXPR, arg1,
5363 TREE_OPERAND (xarg0, 1), 1)))
5364 && (tree_int_cst_sgn (c2) >= 0
5365 || integer_zerop (const_binop (TRUNC_MOD_EXPR, c2,
5368 tree outer_div = integer_one_node;
5369 tree c1 = TREE_OPERAND (xarg0, 1);
5372 /* If C3 > C1, set them equal and do a divide by
5373 C3/C1 at the end of the operation. */
5374 if (tree_int_cst_lt (c1, c3))
5375 outer_div = const_binop (code, c3, c1, 0), c3 = c1;
5377 /* The result is A * (C1/C3) + (C2/C3). */
5378 t = fold (build (PLUS_EXPR, type,
5379 fold (build (MULT_EXPR, type,
5380 TREE_OPERAND (xarg0, 0),
5381 const_binop (code, c1, c3, 1))),
5382 const_binop (code, c2, c3, 1)));
5384 if (! integer_onep (outer_div))
5385 t = fold (build (code, type, t, convert (type, outer_div)));
5397 case FLOOR_MOD_EXPR:
5398 case ROUND_MOD_EXPR:
5399 case TRUNC_MOD_EXPR:
5400 if (integer_onep (arg1))
5401 return omit_one_operand (type, integer_zero_node, arg0);
5402 if (integer_zerop (arg1))
5405 /* Look for ((a * C1) % C3) or (((a * C1) + C2) % C3),
5406 where C1 % C3 == 0. Handle similarly to the division case,
5407 but don't bother with SAVE_EXPRs. */
5409 if (TREE_CODE (arg1) == INTEGER_CST
5410 && ! integer_zerop (arg1))
5412 tree c2 = integer_zero_node;
5415 if (TREE_CODE (xarg0) == PLUS_EXPR
5416 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST)
5417 c2 = TREE_OPERAND (xarg0, 1), xarg0 = TREE_OPERAND (xarg0, 0);
5418 else if (TREE_CODE (xarg0) == MINUS_EXPR
5419 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5420 && ! TREE_UNSIGNED (type))
5422 c2 = fold (build1 (NEGATE_EXPR, type, TREE_OPERAND (xarg0, 1)));
5423 xarg0 = TREE_OPERAND (xarg0, 0);
5428 if (TREE_CODE (xarg0) == MULT_EXPR
5429 && TREE_CODE (TREE_OPERAND (xarg0, 1)) == INTEGER_CST
5430 && integer_zerop (const_binop (TRUNC_MOD_EXPR,
5431 TREE_OPERAND (xarg0, 1),
5433 && tree_int_cst_sgn (c2) >= 0)
5434 /* The result is (C2%C3). */
5435 return omit_one_operand (type, const_binop (code, c2, arg1, 1),
5436 TREE_OPERAND (xarg0, 0));
5445 if (integer_zerop (arg1))
5446 return non_lvalue (convert (type, arg0));
5447 /* Since negative shift count is not well-defined,
5448 don't try to compute it in the compiler. */
5449 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
5451 /* Rewrite an LROTATE_EXPR by a constant into an
5452 RROTATE_EXPR by a new constant. */
5453 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
5455 TREE_SET_CODE (t, RROTATE_EXPR);
5456 code = RROTATE_EXPR;
5457 TREE_OPERAND (t, 1) = arg1
5460 convert (TREE_TYPE (arg1),
5461 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
5463 if (tree_int_cst_sgn (arg1) < 0)
5467 /* If we have a rotate of a bit operation with the rotate count and
5468 the second operand of the bit operation both constant,
5469 permute the two operations. */
5470 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5471 && (TREE_CODE (arg0) == BIT_AND_EXPR
5472 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
5473 || TREE_CODE (arg0) == BIT_IOR_EXPR
5474 || TREE_CODE (arg0) == BIT_XOR_EXPR)
5475 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
5476 return fold (build (TREE_CODE (arg0), type,
5477 fold (build (code, type,
5478 TREE_OPERAND (arg0, 0), arg1)),
5479 fold (build (code, type,
5480 TREE_OPERAND (arg0, 1), arg1))));
5482 /* Two consecutive rotates adding up to the width of the mode can
5484 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
5485 && TREE_CODE (arg0) == RROTATE_EXPR
5486 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5487 && TREE_INT_CST_HIGH (arg1) == 0
5488 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
5489 && ((TREE_INT_CST_LOW (arg1)
5490 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
5491 == GET_MODE_BITSIZE (TYPE_MODE (type))))
5492 return TREE_OPERAND (arg0, 0);
5497 if (operand_equal_p (arg0, arg1, 0))
5499 if (INTEGRAL_TYPE_P (type)
5500 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
5501 return omit_one_operand (type, arg1, arg0);
5505 if (operand_equal_p (arg0, arg1, 0))
5507 if (INTEGRAL_TYPE_P (type)
5508 && TYPE_MAX_VALUE (type)
5509 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
5510 return omit_one_operand (type, arg1, arg0);
5513 case TRUTH_NOT_EXPR:
5514 /* Note that the operand of this must be an int
5515 and its values must be 0 or 1.
5516 ("true" is a fixed value perhaps depending on the language,
5517 but we don't handle values other than 1 correctly yet.) */
5518 tem = invert_truthvalue (arg0);
5519 /* Avoid infinite recursion. */
5520 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
5522 return convert (type, tem);
5524 case TRUTH_ANDIF_EXPR:
5525 /* Note that the operands of this must be ints
5526 and their values must be 0 or 1.
5527 ("true" is a fixed value perhaps depending on the language.) */
5528 /* If first arg is constant zero, return it. */
5529 if (integer_zerop (arg0))
5531 case TRUTH_AND_EXPR:
5532 /* If either arg is constant true, drop it. */
5533 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5534 return non_lvalue (arg1);
5535 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5536 return non_lvalue (arg0);
5537 /* If second arg is constant zero, result is zero, but first arg
5538 must be evaluated. */
5539 if (integer_zerop (arg1))
5540 return omit_one_operand (type, arg1, arg0);
5541 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
5542 case will be handled here. */
5543 if (integer_zerop (arg0))
5544 return omit_one_operand (type, arg0, arg1);
5547 /* We only do these simplifications if we are optimizing. */
5551 /* Check for things like (A || B) && (A || C). We can convert this
5552 to A || (B && C). Note that either operator can be any of the four
5553 truth and/or operations and the transformation will still be
5554 valid. Also note that we only care about order for the
5555 ANDIF and ORIF operators. If B contains side effects, this
5556 might change the truth-value of A. */
5557 if (TREE_CODE (arg0) == TREE_CODE (arg1)
5558 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
5559 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
5560 || TREE_CODE (arg0) == TRUTH_AND_EXPR
5561 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
5562 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
5564 tree a00 = TREE_OPERAND (arg0, 0);
5565 tree a01 = TREE_OPERAND (arg0, 1);
5566 tree a10 = TREE_OPERAND (arg1, 0);
5567 tree a11 = TREE_OPERAND (arg1, 1);
5568 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
5569 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
5570 && (code == TRUTH_AND_EXPR
5571 || code == TRUTH_OR_EXPR));
5573 if (operand_equal_p (a00, a10, 0))
5574 return fold (build (TREE_CODE (arg0), type, a00,
5575 fold (build (code, type, a01, a11))));
5576 else if (commutative && operand_equal_p (a00, a11, 0))
5577 return fold (build (TREE_CODE (arg0), type, a00,
5578 fold (build (code, type, a01, a10))));
5579 else if (commutative && operand_equal_p (a01, a10, 0))
5580 return fold (build (TREE_CODE (arg0), type, a01,
5581 fold (build (code, type, a00, a11))));
5583 /* This case if tricky because we must either have commutative
5584 operators or else A10 must not have side-effects. */
5586 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
5587 && operand_equal_p (a01, a11, 0))
5588 return fold (build (TREE_CODE (arg0), type,
5589 fold (build (code, type, a00, a10)),
5593 /* See if we can build a range comparison. */
5594 if (0 != (tem = fold_range_test (t)))
5597 /* Check for the possibility of merging component references. If our
5598 lhs is another similar operation, try to merge its rhs with our
5599 rhs. Then try to merge our lhs and rhs. */
5600 if (TREE_CODE (arg0) == code
5601 && 0 != (tem = fold_truthop (code, type,
5602 TREE_OPERAND (arg0, 1), arg1)))
5603 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
5605 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
5610 case TRUTH_ORIF_EXPR:
5611 /* Note that the operands of this must be ints
5612 and their values must be 0 or true.
5613 ("true" is a fixed value perhaps depending on the language.) */
5614 /* If first arg is constant true, return it. */
5615 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5618 /* If either arg is constant zero, drop it. */
5619 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
5620 return non_lvalue (arg1);
5621 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1))
5622 return non_lvalue (arg0);
5623 /* If second arg is constant true, result is true, but we must
5624 evaluate first arg. */
5625 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
5626 return omit_one_operand (type, arg1, arg0);
5627 /* Likewise for first arg, but note this only occurs here for
5629 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
5630 return omit_one_operand (type, arg0, arg1);
5633 case TRUTH_XOR_EXPR:
5634 /* If either arg is constant zero, drop it. */
5635 if (integer_zerop (arg0))
5636 return non_lvalue (arg1);
5637 if (integer_zerop (arg1))
5638 return non_lvalue (arg0);
5639 /* If either arg is constant true, this is a logical inversion. */
5640 if (integer_onep (arg0))
5641 return non_lvalue (invert_truthvalue (arg1));
5642 if (integer_onep (arg1))
5643 return non_lvalue (invert_truthvalue (arg0));
5652 /* If one arg is a constant integer, put it last. */
5653 if (TREE_CODE (arg0) == INTEGER_CST
5654 && TREE_CODE (arg1) != INTEGER_CST)
5656 TREE_OPERAND (t, 0) = arg1;
5657 TREE_OPERAND (t, 1) = arg0;
5658 arg0 = TREE_OPERAND (t, 0);
5659 arg1 = TREE_OPERAND (t, 1);
5660 code = swap_tree_comparison (code);
5661 TREE_SET_CODE (t, code);
5664 /* Convert foo++ == CONST into ++foo == CONST + INCR.
5665 First, see if one arg is constant; find the constant arg
5666 and the other one. */
5668 tree constop = 0, varop = NULL_TREE;
5669 int constopnum = -1;
5671 if (TREE_CONSTANT (arg1))
5672 constopnum = 1, constop = arg1, varop = arg0;
5673 if (TREE_CONSTANT (arg0))
5674 constopnum = 0, constop = arg0, varop = arg1;
5676 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
5678 /* This optimization is invalid for ordered comparisons
5679 if CONST+INCR overflows or if foo+incr might overflow.
5680 This optimization is invalid for floating point due to rounding.
5681 For pointer types we assume overflow doesn't happen. */
5682 if (POINTER_TYPE_P (TREE_TYPE (varop))
5683 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
5684 && (code == EQ_EXPR || code == NE_EXPR)))
5687 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
5688 constop, TREE_OPERAND (varop, 1)));
5689 TREE_SET_CODE (varop, PREINCREMENT_EXPR);
5691 /* If VAROP is a reference to a bitfield, we must mask
5692 the constant by the width of the field. */
5693 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
5694 && DECL_BIT_FIELD(TREE_OPERAND
5695 (TREE_OPERAND (varop, 0), 1)))
5698 = TREE_INT_CST_LOW (DECL_SIZE
5700 (TREE_OPERAND (varop, 0), 1)));
5701 tree mask, unsigned_type;
5703 tree folded_compare;
5705 /* First check whether the comparison would come out
5706 always the same. If we don't do that we would
5707 change the meaning with the masking. */
5708 if (constopnum == 0)
5709 folded_compare = fold (build (code, type, constop,
5710 TREE_OPERAND (varop, 0)));
5712 folded_compare = fold (build (code, type,
5713 TREE_OPERAND (varop, 0),
5715 if (integer_zerop (folded_compare)
5716 || integer_onep (folded_compare))
5717 return omit_one_operand (type, folded_compare, varop);
5719 unsigned_type = type_for_size (size, 1);
5720 precision = TYPE_PRECISION (unsigned_type);
5721 mask = build_int_2 (~0, ~0);
5722 TREE_TYPE (mask) = unsigned_type;
5723 force_fit_type (mask, 0);
5724 mask = const_binop (RSHIFT_EXPR, mask,
5725 size_int (precision - size), 0);
5726 newconst = fold (build (BIT_AND_EXPR,
5727 TREE_TYPE (varop), newconst,
5728 convert (TREE_TYPE (varop),
5733 t = build (code, type, TREE_OPERAND (t, 0),
5734 TREE_OPERAND (t, 1));
5735 TREE_OPERAND (t, constopnum) = newconst;
5739 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
5741 if (POINTER_TYPE_P (TREE_TYPE (varop))
5742 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
5743 && (code == EQ_EXPR || code == NE_EXPR)))
5746 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
5747 constop, TREE_OPERAND (varop, 1)));
5748 TREE_SET_CODE (varop, PREDECREMENT_EXPR);
5750 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
5751 && DECL_BIT_FIELD(TREE_OPERAND
5752 (TREE_OPERAND (varop, 0), 1)))
5755 = TREE_INT_CST_LOW (DECL_SIZE
5757 (TREE_OPERAND (varop, 0), 1)));
5758 tree mask, unsigned_type;
5760 tree folded_compare;
5762 if (constopnum == 0)
5763 folded_compare = fold (build (code, type, constop,
5764 TREE_OPERAND (varop, 0)));
5766 folded_compare = fold (build (code, type,
5767 TREE_OPERAND (varop, 0),
5769 if (integer_zerop (folded_compare)
5770 || integer_onep (folded_compare))
5771 return omit_one_operand (type, folded_compare, varop);
5773 unsigned_type = type_for_size (size, 1);
5774 precision = TYPE_PRECISION (unsigned_type);
5775 mask = build_int_2 (~0, ~0);
5776 TREE_TYPE (mask) = TREE_TYPE (varop);
5777 force_fit_type (mask, 0);
5778 mask = const_binop (RSHIFT_EXPR, mask,
5779 size_int (precision - size), 0);
5780 newconst = fold (build (BIT_AND_EXPR,
5781 TREE_TYPE (varop), newconst,
5782 convert (TREE_TYPE (varop),
5787 t = build (code, type, TREE_OPERAND (t, 0),
5788 TREE_OPERAND (t, 1));
5789 TREE_OPERAND (t, constopnum) = newconst;
5795 /* Change X >= CST to X > (CST - 1) if CST is positive. */
5796 if (TREE_CODE (arg1) == INTEGER_CST
5797 && TREE_CODE (arg0) != INTEGER_CST
5798 && tree_int_cst_sgn (arg1) > 0)
5800 switch (TREE_CODE (t))
5804 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
5805 t = build (code, type, TREE_OPERAND (t, 0), arg1);
5810 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
5811 t = build (code, type, TREE_OPERAND (t, 0), arg1);
5819 /* If this is an EQ or NE comparison with zero and ARG0 is
5820 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
5821 two operations, but the latter can be done in one less insn
5822 on machines that have only two-operand insns or on which a
5823 constant cannot be the first operand. */
5824 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
5825 && TREE_CODE (arg0) == BIT_AND_EXPR)
5827 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
5828 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
5830 fold (build (code, type,
5831 build (BIT_AND_EXPR, TREE_TYPE (arg0),
5833 TREE_TYPE (TREE_OPERAND (arg0, 0)),
5834 TREE_OPERAND (arg0, 1),
5835 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
5836 convert (TREE_TYPE (arg0),
5839 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
5840 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
5842 fold (build (code, type,
5843 build (BIT_AND_EXPR, TREE_TYPE (arg0),
5845 TREE_TYPE (TREE_OPERAND (arg0, 1)),
5846 TREE_OPERAND (arg0, 0),
5847 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
5848 convert (TREE_TYPE (arg0),
5853 /* If this is an NE or EQ comparison of zero against the result of a
5854 signed MOD operation whose second operand is a power of 2, make
5855 the MOD operation unsigned since it is simpler and equivalent. */
5856 if ((code == NE_EXPR || code == EQ_EXPR)
5857 && integer_zerop (arg1)
5858 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
5859 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
5860 || TREE_CODE (arg0) == CEIL_MOD_EXPR
5861 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
5862 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
5863 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5865 tree newtype = unsigned_type (TREE_TYPE (arg0));
5866 tree newmod = build (TREE_CODE (arg0), newtype,
5867 convert (newtype, TREE_OPERAND (arg0, 0)),
5868 convert (newtype, TREE_OPERAND (arg0, 1)));
5870 return build (code, type, newmod, convert (newtype, arg1));
5873 /* If this is an NE comparison of zero with an AND of one, remove the
5874 comparison since the AND will give the correct value. */
5875 if (code == NE_EXPR && integer_zerop (arg1)
5876 && TREE_CODE (arg0) == BIT_AND_EXPR
5877 && integer_onep (TREE_OPERAND (arg0, 1)))
5878 return convert (type, arg0);
5880 /* If we have (A & C) == C where C is a power of 2, convert this into
5881 (A & C) != 0. Similarly for NE_EXPR. */
5882 if ((code == EQ_EXPR || code == NE_EXPR)
5883 && TREE_CODE (arg0) == BIT_AND_EXPR
5884 && integer_pow2p (TREE_OPERAND (arg0, 1))
5885 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
5886 return build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
5887 arg0, integer_zero_node);
5889 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
5890 and similarly for >= into !=. */
5891 if ((code == LT_EXPR || code == GE_EXPR)
5892 && TREE_UNSIGNED (TREE_TYPE (arg0))
5893 && TREE_CODE (arg1) == LSHIFT_EXPR
5894 && integer_onep (TREE_OPERAND (arg1, 0)))
5895 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
5896 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
5897 TREE_OPERAND (arg1, 1)),
5898 convert (TREE_TYPE (arg0), integer_zero_node));
5900 else if ((code == LT_EXPR || code == GE_EXPR)
5901 && TREE_UNSIGNED (TREE_TYPE (arg0))
5902 && (TREE_CODE (arg1) == NOP_EXPR
5903 || TREE_CODE (arg1) == CONVERT_EXPR)
5904 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
5905 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
5907 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
5908 convert (TREE_TYPE (arg0),
5909 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
5910 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
5911 convert (TREE_TYPE (arg0), integer_zero_node));
5913 /* Simplify comparison of something with itself. (For IEEE
5914 floating-point, we can only do some of these simplifications.) */
5915 if (operand_equal_p (arg0, arg1, 0))
5922 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
5923 return constant_boolean_node (1, type);
5925 TREE_SET_CODE (t, code);
5929 /* For NE, we can only do this simplification if integer. */
5930 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
5932 /* ... fall through ... */
5935 return constant_boolean_node (0, type);
5941 /* An unsigned comparison against 0 can be simplified. */
5942 if (integer_zerop (arg1)
5943 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
5944 || POINTER_TYPE_P (TREE_TYPE (arg1)))
5945 && TREE_UNSIGNED (TREE_TYPE (arg1)))
5947 switch (TREE_CODE (t))
5951 TREE_SET_CODE (t, NE_EXPR);
5955 TREE_SET_CODE (t, EQ_EXPR);
5958 return omit_one_operand (type,
5959 convert (type, integer_one_node),
5962 return omit_one_operand (type,
5963 convert (type, integer_zero_node),
5970 /* An unsigned <= 0x7fffffff can be simplified. */
5972 int width = TYPE_PRECISION (TREE_TYPE (arg1));
5973 if (TREE_CODE (arg1) == INTEGER_CST
5974 && ! TREE_CONSTANT_OVERFLOW (arg1)
5975 && width <= HOST_BITS_PER_WIDE_INT
5976 && TREE_INT_CST_LOW (arg1) == ((HOST_WIDE_INT) 1 << (width - 1)) - 1
5977 && TREE_INT_CST_HIGH (arg1) == 0
5978 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
5979 || POINTER_TYPE_P (TREE_TYPE (arg1)))
5980 && TREE_UNSIGNED (TREE_TYPE (arg1)))
5982 switch (TREE_CODE (t))
5985 return fold (build (GE_EXPR, type,
5986 convert (signed_type (TREE_TYPE (arg0)),
5988 convert (signed_type (TREE_TYPE (arg1)),
5989 integer_zero_node)));
5991 return fold (build (LT_EXPR, type,
5992 convert (signed_type (TREE_TYPE (arg0)),
5994 convert (signed_type (TREE_TYPE (arg1)),
5995 integer_zero_node)));
6002 /* If we are comparing an expression that just has comparisons
6003 of two integer values, arithmetic expressions of those comparisons,
6004 and constants, we can simplify it. There are only three cases
6005 to check: the two values can either be equal, the first can be
6006 greater, or the second can be greater. Fold the expression for
6007 those three values. Since each value must be 0 or 1, we have
6008 eight possibilities, each of which corresponds to the constant 0
6009 or 1 or one of the six possible comparisons.
6011 This handles common cases like (a > b) == 0 but also handles
6012 expressions like ((x > y) - (y > x)) > 0, which supposedly
6013 occur in macroized code. */
6015 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
6017 tree cval1 = 0, cval2 = 0;
6020 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
6021 /* Don't handle degenerate cases here; they should already
6022 have been handled anyway. */
6023 && cval1 != 0 && cval2 != 0
6024 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
6025 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
6026 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
6027 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
6028 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
6029 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
6030 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
6032 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
6033 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
6035 /* We can't just pass T to eval_subst in case cval1 or cval2
6036 was the same as ARG1. */
6039 = fold (build (code, type,
6040 eval_subst (arg0, cval1, maxval, cval2, minval),
6043 = fold (build (code, type,
6044 eval_subst (arg0, cval1, maxval, cval2, maxval),
6047 = fold (build (code, type,
6048 eval_subst (arg0, cval1, minval, cval2, maxval),
6051 /* All three of these results should be 0 or 1. Confirm they
6052 are. Then use those values to select the proper code
6055 if ((integer_zerop (high_result)
6056 || integer_onep (high_result))
6057 && (integer_zerop (equal_result)
6058 || integer_onep (equal_result))
6059 && (integer_zerop (low_result)
6060 || integer_onep (low_result)))
6062 /* Make a 3-bit mask with the high-order bit being the
6063 value for `>', the next for '=', and the low for '<'. */
6064 switch ((integer_onep (high_result) * 4)
6065 + (integer_onep (equal_result) * 2)
6066 + integer_onep (low_result))
6070 return omit_one_operand (type, integer_zero_node, arg0);
6091 return omit_one_operand (type, integer_one_node, arg0);
6094 t = build (code, type, cval1, cval2);
6096 return save_expr (t);
6103 /* If this is a comparison of a field, we may be able to simplify it. */
6104 if ((TREE_CODE (arg0) == COMPONENT_REF
6105 || TREE_CODE (arg0) == BIT_FIELD_REF)
6106 && (code == EQ_EXPR || code == NE_EXPR)
6107 /* Handle the constant case even without -O
6108 to make sure the warnings are given. */
6109 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
6111 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
6115 /* If this is a comparison of complex values and either or both sides
6116 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6117 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6118 This may prevent needless evaluations. */
6119 if ((code == EQ_EXPR || code == NE_EXPR)
6120 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
6121 && (TREE_CODE (arg0) == COMPLEX_EXPR
6122 || TREE_CODE (arg1) == COMPLEX_EXPR
6123 || TREE_CODE (arg0) == COMPLEX_CST
6124 || TREE_CODE (arg1) == COMPLEX_CST))
6126 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
6127 tree real0, imag0, real1, imag1;
6129 arg0 = save_expr (arg0);
6130 arg1 = save_expr (arg1);
6131 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
6132 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
6133 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
6134 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
6136 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
6139 fold (build (code, type, real0, real1)),
6140 fold (build (code, type, imag0, imag1))));
6143 /* From here on, the only cases we handle are when the result is
6144 known to be a constant.
6146 To compute GT, swap the arguments and do LT.
6147 To compute GE, do LT and invert the result.
6148 To compute LE, swap the arguments, do LT and invert the result.
6149 To compute NE, do EQ and invert the result.
6151 Therefore, the code below must handle only EQ and LT. */
6153 if (code == LE_EXPR || code == GT_EXPR)
6155 tem = arg0, arg0 = arg1, arg1 = tem;
6156 code = swap_tree_comparison (code);
6159 /* Note that it is safe to invert for real values here because we
6160 will check below in the one case that it matters. */
6163 if (code == NE_EXPR || code == GE_EXPR)
6166 code = invert_tree_comparison (code);
6169 /* Compute a result for LT or EQ if args permit;
6170 otherwise return T. */
6171 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
6173 if (code == EQ_EXPR)
6174 t1 = build_int_2 ((TREE_INT_CST_LOW (arg0)
6175 == TREE_INT_CST_LOW (arg1))
6176 && (TREE_INT_CST_HIGH (arg0)
6177 == TREE_INT_CST_HIGH (arg1)),
6180 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
6181 ? INT_CST_LT_UNSIGNED (arg0, arg1)
6182 : INT_CST_LT (arg0, arg1)),
6186 #if 0 /* This is no longer useful, but breaks some real code. */
6187 /* Assume a nonexplicit constant cannot equal an explicit one,
6188 since such code would be undefined anyway.
6189 Exception: on sysvr4, using #pragma weak,
6190 a label can come out as 0. */
6191 else if (TREE_CODE (arg1) == INTEGER_CST
6192 && !integer_zerop (arg1)
6193 && TREE_CONSTANT (arg0)
6194 && TREE_CODE (arg0) == ADDR_EXPR
6196 t1 = build_int_2 (0, 0);
6198 /* Two real constants can be compared explicitly. */
6199 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
6201 /* If either operand is a NaN, the result is false with two
6202 exceptions: First, an NE_EXPR is true on NaNs, but that case
6203 is already handled correctly since we will be inverting the
6204 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6205 or a GE_EXPR into a LT_EXPR, we must return true so that it
6206 will be inverted into false. */
6208 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
6209 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
6210 t1 = build_int_2 (invert && code == LT_EXPR, 0);
6212 else if (code == EQ_EXPR)
6213 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
6214 TREE_REAL_CST (arg1)),
6217 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
6218 TREE_REAL_CST (arg1)),
6222 if (t1 == NULL_TREE)
6226 TREE_INT_CST_LOW (t1) ^= 1;
6228 TREE_TYPE (t1) = type;
6229 if (TREE_CODE (type) == BOOLEAN_TYPE)
6230 return truthvalue_conversion (t1);
6234 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
6235 so all simple results must be passed through pedantic_non_lvalue. */
6236 if (TREE_CODE (arg0) == INTEGER_CST)
6237 return pedantic_non_lvalue
6238 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
6239 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
6240 return pedantic_omit_one_operand (type, arg1, arg0);
6242 /* If the second operand is zero, invert the comparison and swap
6243 the second and third operands. Likewise if the second operand
6244 is constant and the third is not or if the third operand is
6245 equivalent to the first operand of the comparison. */
6247 if (integer_zerop (arg1)
6248 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
6249 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6250 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6251 TREE_OPERAND (t, 2),
6252 TREE_OPERAND (arg0, 1))))
6254 /* See if this can be inverted. If it can't, possibly because
6255 it was a floating-point inequality comparison, don't do
6257 tem = invert_truthvalue (arg0);
6259 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6261 t = build (code, type, tem,
6262 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6264 /* arg1 should be the first argument of the new T. */
6265 arg1 = TREE_OPERAND (t, 1);
6270 /* If we have A op B ? A : C, we may be able to convert this to a
6271 simpler expression, depending on the operation and the values
6272 of B and C. IEEE floating point prevents this though,
6273 because A or B might be -0.0 or a NaN. */
6275 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
6276 && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
6277 || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0)))
6279 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
6280 arg1, TREE_OPERAND (arg0, 1)))
6282 tree arg2 = TREE_OPERAND (t, 2);
6283 enum tree_code comp_code = TREE_CODE (arg0);
6287 /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
6288 depending on the comparison operation. */
6289 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
6290 ? real_zerop (TREE_OPERAND (arg0, 1))
6291 : integer_zerop (TREE_OPERAND (arg0, 1)))
6292 && TREE_CODE (arg2) == NEGATE_EXPR
6293 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
6297 return pedantic_non_lvalue
6298 (fold (build1 (NEGATE_EXPR, type, arg1)));
6300 return pedantic_non_lvalue (convert (type, arg1));
6303 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6304 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6305 return pedantic_non_lvalue
6306 (convert (type, fold (build1 (ABS_EXPR,
6307 TREE_TYPE (arg1), arg1))));
6310 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6311 arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
6312 return pedantic_non_lvalue
6313 (fold (build1 (NEGATE_EXPR, type,
6315 fold (build1 (ABS_EXPR,
6322 /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
6325 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
6327 if (comp_code == NE_EXPR)
6328 return pedantic_non_lvalue (convert (type, arg1));
6329 else if (comp_code == EQ_EXPR)
6330 return pedantic_non_lvalue (convert (type, integer_zero_node));
6333 /* If this is A op B ? A : B, this is either A, B, min (A, B),
6334 or max (A, B), depending on the operation. */
6336 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
6337 arg2, TREE_OPERAND (arg0, 0)))
6339 tree comp_op0 = TREE_OPERAND (arg0, 0);
6340 tree comp_op1 = TREE_OPERAND (arg0, 1);
6341 tree comp_type = TREE_TYPE (comp_op0);
6346 return pedantic_non_lvalue (convert (type, arg2));
6348 return pedantic_non_lvalue (convert (type, arg1));
6351 /* In C++ a ?: expression can be an lvalue, so put the
6352 operand which will be used if they are equal first
6353 so that we can convert this back to the
6354 corresponding COND_EXPR. */
6355 return pedantic_non_lvalue
6356 (convert (type, (fold (build (MIN_EXPR, comp_type,
6357 (comp_code == LE_EXPR
6358 ? comp_op0 : comp_op1),
6359 (comp_code == LE_EXPR
6360 ? comp_op1 : comp_op0))))));
6364 return pedantic_non_lvalue
6365 (convert (type, fold (build (MAX_EXPR, comp_type,
6366 (comp_code == GE_EXPR
6367 ? comp_op0 : comp_op1),
6368 (comp_code == GE_EXPR
6369 ? comp_op1 : comp_op0)))));
6376 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
6377 we might still be able to simplify this. For example,
6378 if C1 is one less or one more than C2, this might have started
6379 out as a MIN or MAX and been transformed by this function.
6380 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
6382 if (INTEGRAL_TYPE_P (type)
6383 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6384 && TREE_CODE (arg2) == INTEGER_CST)
6388 /* We can replace A with C1 in this case. */
6389 arg1 = convert (type, TREE_OPERAND (arg0, 1));
6390 t = build (code, type, TREE_OPERAND (t, 0), arg1,
6391 TREE_OPERAND (t, 2));
6395 /* If C1 is C2 + 1, this is min(A, C2). */
6396 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6397 && operand_equal_p (TREE_OPERAND (arg0, 1),
6398 const_binop (PLUS_EXPR, arg2,
6399 integer_one_node, 0), 1))
6400 return pedantic_non_lvalue
6401 (fold (build (MIN_EXPR, type, arg1, arg2)));
6405 /* If C1 is C2 - 1, this is min(A, C2). */
6406 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6407 && operand_equal_p (TREE_OPERAND (arg0, 1),
6408 const_binop (MINUS_EXPR, arg2,
6409 integer_one_node, 0), 1))
6410 return pedantic_non_lvalue
6411 (fold (build (MIN_EXPR, type, arg1, arg2)));
6415 /* If C1 is C2 - 1, this is max(A, C2). */
6416 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
6417 && operand_equal_p (TREE_OPERAND (arg0, 1),
6418 const_binop (MINUS_EXPR, arg2,
6419 integer_one_node, 0), 1))
6420 return pedantic_non_lvalue
6421 (fold (build (MAX_EXPR, type, arg1, arg2)));
6425 /* If C1 is C2 + 1, this is max(A, C2). */
6426 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
6427 && operand_equal_p (TREE_OPERAND (arg0, 1),
6428 const_binop (PLUS_EXPR, arg2,
6429 integer_one_node, 0), 1))
6430 return pedantic_non_lvalue
6431 (fold (build (MAX_EXPR, type, arg1, arg2)));
6440 /* If the second operand is simpler than the third, swap them
6441 since that produces better jump optimization results. */
6442 if ((TREE_CONSTANT (arg1) || TREE_CODE_CLASS (TREE_CODE (arg1)) == 'd'
6443 || TREE_CODE (arg1) == SAVE_EXPR)
6444 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
6445 || TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (t, 2))) == 'd'
6446 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
6448 /* See if this can be inverted. If it can't, possibly because
6449 it was a floating-point inequality comparison, don't do
6451 tem = invert_truthvalue (arg0);
6453 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
6455 t = build (code, type, tem,
6456 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
6458 /* arg1 should be the first argument of the new T. */
6459 arg1 = TREE_OPERAND (t, 1);
6464 /* Convert A ? 1 : 0 to simply A. */
6465 if (integer_onep (TREE_OPERAND (t, 1))
6466 && integer_zerop (TREE_OPERAND (t, 2))
6467 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
6468 call to fold will try to move the conversion inside
6469 a COND, which will recurse. In that case, the COND_EXPR
6470 is probably the best choice, so leave it alone. */
6471 && type == TREE_TYPE (arg0))
6472 return pedantic_non_lvalue (arg0);
6474 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
6475 operation is simply A & 2. */
6477 if (integer_zerop (TREE_OPERAND (t, 2))
6478 && TREE_CODE (arg0) == NE_EXPR
6479 && integer_zerop (TREE_OPERAND (arg0, 1))
6480 && integer_pow2p (arg1)
6481 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
6482 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
6484 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
6489 /* When pedantic, a compound expression can be neither an lvalue
6490 nor an integer constant expression. */
6491 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
6493 /* Don't let (0, 0) be null pointer constant. */
6494 if (integer_zerop (arg1))
6495 return build1 (NOP_EXPR, TREE_TYPE (arg1), arg1);
6500 return build_complex (type, arg0, arg1);
6504 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6506 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6507 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
6508 TREE_OPERAND (arg0, 1));
6509 else if (TREE_CODE (arg0) == COMPLEX_CST)
6510 return TREE_REALPART (arg0);
6511 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6512 return fold (build (TREE_CODE (arg0), type,
6513 fold (build1 (REALPART_EXPR, type,
6514 TREE_OPERAND (arg0, 0))),
6515 fold (build1 (REALPART_EXPR,
6516 type, TREE_OPERAND (arg0, 1)))));
6520 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6521 return convert (type, integer_zero_node);
6522 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6523 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
6524 TREE_OPERAND (arg0, 0));
6525 else if (TREE_CODE (arg0) == COMPLEX_CST)
6526 return TREE_IMAGPART (arg0);
6527 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6528 return fold (build (TREE_CODE (arg0), type,
6529 fold (build1 (IMAGPART_EXPR, type,
6530 TREE_OPERAND (arg0, 0))),
6531 fold (build1 (IMAGPART_EXPR, type,
6532 TREE_OPERAND (arg0, 1)))));
6535 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
6537 case CLEANUP_POINT_EXPR:
6538 if (! has_cleanups (arg0))
6539 return TREE_OPERAND (t, 0);
6542 enum tree_code code0 = TREE_CODE (arg0);
6543 int kind0 = TREE_CODE_CLASS (code0);
6544 tree arg00 = TREE_OPERAND (arg0, 0);
6547 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
6548 return fold (build1 (code0, type,
6549 fold (build1 (CLEANUP_POINT_EXPR,
6550 TREE_TYPE (arg00), arg00))));
6552 if (kind0 == '<' || kind0 == '2'
6553 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
6554 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
6555 || code0 == TRUTH_XOR_EXPR)
6557 arg01 = TREE_OPERAND (arg0, 1);
6559 if (TREE_CONSTANT (arg00)
6560 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
6561 && ! has_cleanups (arg00)))
6562 return fold (build (code0, type, arg00,
6563 fold (build1 (CLEANUP_POINT_EXPR,
6564 TREE_TYPE (arg01), arg01))));
6566 if (TREE_CONSTANT (arg01))
6567 return fold (build (code0, type,
6568 fold (build1 (CLEANUP_POINT_EXPR,
6569 TREE_TYPE (arg00), arg00)),
6578 } /* switch (code) */
6581 /* Determine if first argument is a multiple of second argument.
6582 Return 0 if it is not, or is not easily determined to so be.
6584 An example of the sort of thing we care about (at this point --
6585 this routine could surely be made more general, and expanded
6586 to do what the *_DIV_EXPR's fold() cases do now) is discovering
6589 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
6595 when we know that the two `SAVE_EXPR (J * 8)' nodes are the
6596 same node (which means they will have the same value at run
6597 time, even though we don't know when they'll be assigned).
6599 This code also handles discovering that
6601 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
6607 (of course) so we don't have to worry about dealing with a
6610 Note that we _look_ inside a SAVE_EXPR only to determine
6611 how it was calculated; it is not safe for fold() to do much
6612 of anything else with the internals of a SAVE_EXPR, since
6613 fold() cannot know when it will be evaluated at run time.
6614 For example, the latter example above _cannot_ be implemented
6619 or any variant thereof, since the value of J at evaluation time
6620 of the original SAVE_EXPR is not necessarily the same at the time
6621 the new expression is evaluated. The only optimization of this
6622 sort that would be valid is changing
6624 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
6630 SAVE_EXPR (I) * SAVE_EXPR (J)
6632 (where the same SAVE_EXPR (J) is used in the original and the
6633 transformed version). */
6636 multiple_of_p (type, top, bottom)
6641 if (operand_equal_p (top, bottom, 0))
6644 if (TREE_CODE (type) != INTEGER_TYPE)
6647 switch (TREE_CODE (top))
6650 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
6651 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
6655 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
6656 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
6659 /* Punt if conversion from non-integral or wider integral type. */
6660 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
6661 || (TYPE_PRECISION (type)
6662 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
6666 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
6669 if ((TREE_CODE (bottom) != INTEGER_CST)
6670 || (tree_int_cst_sgn (top) < 0)
6671 || (tree_int_cst_sgn (bottom) < 0))
6673 return integer_zerop (const_binop (TRUNC_MOD_EXPR,