1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /*@@ This file should be rewritten to use an arbitrary precision
23 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
24 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
25 @@ The routines that translate from the ap rep should
26 @@ warn if precision et. al. is lost.
27 @@ This would also make life easier when this technology is used
28 @@ for cross-compilers. */
30 /* The entry points in this file are fold, size_int_wide, size_binop
31 and force_fit_type_double.
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_double takes a constant, an overflowable flag and a
43 prior overflow indicator. It forces the value to fit the type and
46 Note: Since the folders get called on non-gimple code as well as
47 gimple code, we need to handle GIMPLE tuples as well as their
48 corresponding tree equivalents. */
52 #include "coretypes.h"
57 #include "fixed-value.h"
65 #include "langhooks.h"
68 /* Nonzero if we are folding constants inside an initializer; zero
70 int folding_initializer
= 0;
72 /* The following constants represent a bit based encoding of GCC's
73 comparison operators. This encoding simplifies transformations
74 on relational comparison operators, such as AND and OR. */
75 enum comparison_code
{
94 static void encode (HOST_WIDE_INT
*, unsigned HOST_WIDE_INT
, HOST_WIDE_INT
);
95 static void decode (HOST_WIDE_INT
*, unsigned HOST_WIDE_INT
*, HOST_WIDE_INT
*);
96 static bool negate_mathfn_p (enum built_in_function
);
97 static bool negate_expr_p (tree
);
98 static tree
negate_expr (tree
);
99 static tree
split_tree (tree
, enum tree_code
, tree
*, tree
*, tree
*, int);
100 static tree
associate_trees (tree
, tree
, enum tree_code
, tree
);
101 static tree
const_binop (enum tree_code
, tree
, tree
, int);
102 static enum comparison_code
comparison_to_compcode (enum tree_code
);
103 static enum tree_code
compcode_to_comparison (enum comparison_code
);
104 static tree
combine_comparisons (enum tree_code
, enum tree_code
,
105 enum tree_code
, tree
, tree
, tree
);
106 static int truth_value_p (enum tree_code
);
107 static int operand_equal_for_comparison_p (tree
, tree
, tree
);
108 static int twoval_comparison_p (tree
, tree
*, tree
*, int *);
109 static tree
eval_subst (tree
, tree
, tree
, tree
, tree
);
110 static tree
pedantic_omit_one_operand (tree
, tree
, tree
);
111 static tree
distribute_bit_expr (enum tree_code
, tree
, tree
, tree
);
112 static tree
make_bit_field_ref (tree
, tree
, int, int, int);
113 static tree
optimize_bit_field_compare (enum tree_code
, tree
, tree
, tree
);
114 static tree
decode_field_reference (tree
, HOST_WIDE_INT
*, HOST_WIDE_INT
*,
115 enum machine_mode
*, int *, int *,
117 static int all_ones_mask_p (tree
, int);
118 static tree
sign_bit_p (tree
, tree
);
119 static int simple_operand_p (tree
);
120 static tree
range_binop (enum tree_code
, tree
, tree
, int, tree
, int);
121 static tree
range_predecessor (tree
);
122 static tree
range_successor (tree
);
123 static tree
make_range (tree
, int *, tree
*, tree
*, bool *);
124 static tree
build_range_check (tree
, tree
, int, tree
, tree
);
125 static int merge_ranges (int *, tree
*, tree
*, int, tree
, tree
, int, tree
,
127 static tree
fold_range_test (enum tree_code
, tree
, tree
, tree
);
128 static tree
fold_cond_expr_with_comparison (tree
, tree
, tree
, tree
);
129 static tree
unextend (tree
, int, int, tree
);
130 static tree
fold_truthop (enum tree_code
, tree
, tree
, tree
);
131 static tree
optimize_minmax_comparison (enum tree_code
, tree
, tree
, tree
);
132 static tree
extract_muldiv (tree
, tree
, enum tree_code
, tree
, bool *);
133 static tree
extract_muldiv_1 (tree
, tree
, enum tree_code
, tree
, bool *);
134 static tree
fold_binary_op_with_conditional_arg (enum tree_code
, tree
,
137 static bool fold_real_zero_addition_p (tree
, tree
, int);
138 static tree
fold_mathfn_compare (enum built_in_function
, enum tree_code
,
140 static tree
fold_inf_compare (enum tree_code
, tree
, tree
, tree
);
141 static tree
fold_div_compare (enum tree_code
, tree
, tree
, tree
);
142 static bool reorder_operands_p (tree
, tree
);
143 static tree
fold_negate_const (tree
, tree
);
144 static tree
fold_not_const (tree
, tree
);
145 static tree
fold_relational_const (enum tree_code
, tree
, tree
, tree
);
148 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
149 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
150 and SUM1. Then this yields nonzero if overflow occurred during the
153 Overflow occurs if A and B have the same sign, but A and SUM differ in
154 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
156 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
158 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
159 We do that by representing the two-word integer in 4 words, with only
160 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
161 number. The value of the word is LOWPART + HIGHPART * BASE. */
164 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
165 #define HIGHPART(x) \
166 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
167 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
169 /* Unpack a two-word integer into 4 words.
170 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
171 WORDS points to the array of HOST_WIDE_INTs. */
174 encode (HOST_WIDE_INT
*words
, unsigned HOST_WIDE_INT low
, HOST_WIDE_INT hi
)
176 words
[0] = LOWPART (low
);
177 words
[1] = HIGHPART (low
);
178 words
[2] = LOWPART (hi
);
179 words
[3] = HIGHPART (hi
);
182 /* Pack an array of 4 words into a two-word integer.
183 WORDS points to the array of words.
184 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
187 decode (HOST_WIDE_INT
*words
, unsigned HOST_WIDE_INT
*low
,
190 *low
= words
[0] + words
[1] * BASE
;
191 *hi
= words
[2] + words
[3] * BASE
;
194 /* Force the double-word integer L1, H1 to be within the range of the
195 integer type TYPE. Stores the properly truncated and sign-extended
196 double-word integer in *LV, *HV. Returns true if the operation
197 overflows, that is, argument and result are different. */
200 fit_double_type (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
201 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
, const_tree type
)
203 unsigned HOST_WIDE_INT low0
= l1
;
204 HOST_WIDE_INT high0
= h1
;
206 int sign_extended_type
;
208 if (POINTER_TYPE_P (type
)
209 || TREE_CODE (type
) == OFFSET_TYPE
)
212 prec
= TYPE_PRECISION (type
);
214 /* Size types *are* sign extended. */
215 sign_extended_type
= (!TYPE_UNSIGNED (type
)
216 || (TREE_CODE (type
) == INTEGER_TYPE
217 && TYPE_IS_SIZETYPE (type
)));
219 /* First clear all bits that are beyond the type's precision. */
220 if (prec
>= 2 * HOST_BITS_PER_WIDE_INT
)
222 else if (prec
> HOST_BITS_PER_WIDE_INT
)
223 h1
&= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
227 if (prec
< HOST_BITS_PER_WIDE_INT
)
228 l1
&= ~((HOST_WIDE_INT
) (-1) << prec
);
231 /* Then do sign extension if necessary. */
232 if (!sign_extended_type
)
233 /* No sign extension */;
234 else if (prec
>= 2 * HOST_BITS_PER_WIDE_INT
)
235 /* Correct width already. */;
236 else if (prec
> HOST_BITS_PER_WIDE_INT
)
238 /* Sign extend top half? */
239 if (h1
& ((unsigned HOST_WIDE_INT
)1
240 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)))
241 h1
|= (HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
);
243 else if (prec
== HOST_BITS_PER_WIDE_INT
)
245 if ((HOST_WIDE_INT
)l1
< 0)
250 /* Sign extend bottom half? */
251 if (l1
& ((unsigned HOST_WIDE_INT
)1 << (prec
- 1)))
254 l1
|= (HOST_WIDE_INT
)(-1) << prec
;
261 /* If the value didn't fit, signal overflow. */
262 return l1
!= low0
|| h1
!= high0
;
265 /* We force the double-int HIGH:LOW to the range of the type TYPE by
266 sign or zero extending it.
267 OVERFLOWABLE indicates if we are interested
268 in overflow of the value, when >0 we are only interested in signed
269 overflow, for <0 we are interested in any overflow. OVERFLOWED
270 indicates whether overflow has already occurred. CONST_OVERFLOWED
271 indicates whether constant overflow has already occurred. We force
272 T's value to be within range of T's type (by setting to 0 or 1 all
273 the bits outside the type's range). We set TREE_OVERFLOWED if,
274 OVERFLOWED is nonzero,
275 or OVERFLOWABLE is >0 and signed overflow occurs
276 or OVERFLOWABLE is <0 and any overflow occurs
277 We return a new tree node for the extended double-int. The node
278 is shared if no overflow flags are set. */
281 force_fit_type_double (tree type
, unsigned HOST_WIDE_INT low
,
282 HOST_WIDE_INT high
, int overflowable
,
285 int sign_extended_type
;
288 /* Size types *are* sign extended. */
289 sign_extended_type
= (!TYPE_UNSIGNED (type
)
290 || (TREE_CODE (type
) == INTEGER_TYPE
291 && TYPE_IS_SIZETYPE (type
)));
293 overflow
= fit_double_type (low
, high
, &low
, &high
, type
);
295 /* If we need to set overflow flags, return a new unshared node. */
296 if (overflowed
|| overflow
)
300 || (overflowable
> 0 && sign_extended_type
))
302 tree t
= make_node (INTEGER_CST
);
303 TREE_INT_CST_LOW (t
) = low
;
304 TREE_INT_CST_HIGH (t
) = high
;
305 TREE_TYPE (t
) = type
;
306 TREE_OVERFLOW (t
) = 1;
311 /* Else build a shared node. */
312 return build_int_cst_wide (type
, low
, high
);
315 /* Add two doubleword integers with doubleword result.
316 Return nonzero if the operation overflows according to UNSIGNED_P.
317 Each argument is given as two `HOST_WIDE_INT' pieces.
318 One argument is L1 and H1; the other, L2 and H2.
319 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
322 add_double_with_sign (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
323 unsigned HOST_WIDE_INT l2
, HOST_WIDE_INT h2
,
324 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
,
327 unsigned HOST_WIDE_INT l
;
331 h
= h1
+ h2
+ (l
< l1
);
337 return (unsigned HOST_WIDE_INT
) h
< (unsigned HOST_WIDE_INT
) h1
;
339 return OVERFLOW_SUM_SIGN (h1
, h2
, h
);
342 /* Negate a doubleword integer with doubleword result.
343 Return nonzero if the operation overflows, assuming it's signed.
344 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
345 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
348 neg_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
349 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
355 return (*hv
& h1
) < 0;
365 /* Multiply two doubleword integers with doubleword result.
366 Return nonzero if the operation overflows according to UNSIGNED_P.
367 Each argument is given as two `HOST_WIDE_INT' pieces.
368 One argument is L1 and H1; the other, L2 and H2.
369 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
372 mul_double_with_sign (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
373 unsigned HOST_WIDE_INT l2
, HOST_WIDE_INT h2
,
374 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
,
377 HOST_WIDE_INT arg1
[4];
378 HOST_WIDE_INT arg2
[4];
379 HOST_WIDE_INT prod
[4 * 2];
380 unsigned HOST_WIDE_INT carry
;
382 unsigned HOST_WIDE_INT toplow
, neglow
;
383 HOST_WIDE_INT tophigh
, neghigh
;
385 encode (arg1
, l1
, h1
);
386 encode (arg2
, l2
, h2
);
388 memset (prod
, 0, sizeof prod
);
390 for (i
= 0; i
< 4; i
++)
393 for (j
= 0; j
< 4; j
++)
396 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
397 carry
+= arg1
[i
] * arg2
[j
];
398 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
400 prod
[k
] = LOWPART (carry
);
401 carry
= HIGHPART (carry
);
406 decode (prod
, lv
, hv
);
407 decode (prod
+ 4, &toplow
, &tophigh
);
409 /* Unsigned overflow is immediate. */
411 return (toplow
| tophigh
) != 0;
413 /* Check for signed overflow by calculating the signed representation of the
414 top half of the result; it should agree with the low half's sign bit. */
417 neg_double (l2
, h2
, &neglow
, &neghigh
);
418 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
422 neg_double (l1
, h1
, &neglow
, &neghigh
);
423 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
425 return (*hv
< 0 ? ~(toplow
& tophigh
) : toplow
| tophigh
) != 0;
428 /* Shift the doubleword integer in L1, H1 left by COUNT places
429 keeping only PREC bits of result.
430 Shift right if COUNT is negative.
431 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
432 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
435 lshift_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
436 HOST_WIDE_INT count
, unsigned int prec
,
437 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
, int arith
)
439 unsigned HOST_WIDE_INT signmask
;
443 rshift_double (l1
, h1
, -count
, prec
, lv
, hv
, arith
);
447 if (SHIFT_COUNT_TRUNCATED
)
450 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
452 /* Shifting by the host word size is undefined according to the
453 ANSI standard, so we must handle this as a special case. */
457 else if (count
>= HOST_BITS_PER_WIDE_INT
)
459 *hv
= l1
<< (count
- HOST_BITS_PER_WIDE_INT
);
464 *hv
= (((unsigned HOST_WIDE_INT
) h1
<< count
)
465 | (l1
>> (HOST_BITS_PER_WIDE_INT
- count
- 1) >> 1));
469 /* Sign extend all bits that are beyond the precision. */
471 signmask
= -((prec
> HOST_BITS_PER_WIDE_INT
472 ? ((unsigned HOST_WIDE_INT
) *hv
473 >> (prec
- HOST_BITS_PER_WIDE_INT
- 1))
474 : (*lv
>> (prec
- 1))) & 1);
476 if (prec
>= 2 * HOST_BITS_PER_WIDE_INT
)
478 else if (prec
>= HOST_BITS_PER_WIDE_INT
)
480 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
481 *hv
|= signmask
<< (prec
- HOST_BITS_PER_WIDE_INT
);
486 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << prec
);
487 *lv
|= signmask
<< prec
;
491 /* Shift the doubleword integer in L1, H1 right by COUNT places
492 keeping only PREC bits of result. COUNT must be positive.
493 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
494 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
497 rshift_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
498 HOST_WIDE_INT count
, unsigned int prec
,
499 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
,
502 unsigned HOST_WIDE_INT signmask
;
505 ? -((unsigned HOST_WIDE_INT
) h1
>> (HOST_BITS_PER_WIDE_INT
- 1))
508 if (SHIFT_COUNT_TRUNCATED
)
511 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
513 /* Shifting by the host word size is undefined according to the
514 ANSI standard, so we must handle this as a special case. */
518 else if (count
>= HOST_BITS_PER_WIDE_INT
)
521 *lv
= (unsigned HOST_WIDE_INT
) h1
>> (count
- HOST_BITS_PER_WIDE_INT
);
525 *hv
= (unsigned HOST_WIDE_INT
) h1
>> count
;
527 | ((unsigned HOST_WIDE_INT
) h1
<< (HOST_BITS_PER_WIDE_INT
- count
- 1) << 1));
530 /* Zero / sign extend all bits that are beyond the precision. */
532 if (count
>= (HOST_WIDE_INT
)prec
)
537 else if ((prec
- count
) >= 2 * HOST_BITS_PER_WIDE_INT
)
539 else if ((prec
- count
) >= HOST_BITS_PER_WIDE_INT
)
541 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- count
- HOST_BITS_PER_WIDE_INT
));
542 *hv
|= signmask
<< (prec
- count
- HOST_BITS_PER_WIDE_INT
);
547 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << (prec
- count
));
548 *lv
|= signmask
<< (prec
- count
);
552 /* Rotate the doubleword integer in L1, H1 left by COUNT places
553 keeping only PREC bits of result.
554 Rotate right if COUNT is negative.
555 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
558 lrotate_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
559 HOST_WIDE_INT count
, unsigned int prec
,
560 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
562 unsigned HOST_WIDE_INT s1l
, s2l
;
563 HOST_WIDE_INT s1h
, s2h
;
569 lshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
570 rshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
575 /* Rotate the doubleword integer in L1, H1 left by COUNT places
576 keeping only PREC bits of result. COUNT must be positive.
577 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
580 rrotate_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
581 HOST_WIDE_INT count
, unsigned int prec
,
582 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
584 unsigned HOST_WIDE_INT s1l
, s2l
;
585 HOST_WIDE_INT s1h
, s2h
;
591 rshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
592 lshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
597 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
598 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
599 CODE is a tree code for a kind of division, one of
600 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
602 It controls how the quotient is rounded to an integer.
603 Return nonzero if the operation overflows.
604 UNS nonzero says do unsigned division. */
607 div_and_round_double (enum tree_code code
, int uns
,
608 unsigned HOST_WIDE_INT lnum_orig
, /* num == numerator == dividend */
609 HOST_WIDE_INT hnum_orig
,
610 unsigned HOST_WIDE_INT lden_orig
, /* den == denominator == divisor */
611 HOST_WIDE_INT hden_orig
,
612 unsigned HOST_WIDE_INT
*lquo
,
613 HOST_WIDE_INT
*hquo
, unsigned HOST_WIDE_INT
*lrem
,
617 HOST_WIDE_INT num
[4 + 1]; /* extra element for scaling. */
618 HOST_WIDE_INT den
[4], quo
[4];
620 unsigned HOST_WIDE_INT work
;
621 unsigned HOST_WIDE_INT carry
= 0;
622 unsigned HOST_WIDE_INT lnum
= lnum_orig
;
623 HOST_WIDE_INT hnum
= hnum_orig
;
624 unsigned HOST_WIDE_INT lden
= lden_orig
;
625 HOST_WIDE_INT hden
= hden_orig
;
628 if (hden
== 0 && lden
== 0)
629 overflow
= 1, lden
= 1;
631 /* Calculate quotient sign and convert operands to unsigned. */
637 /* (minimum integer) / (-1) is the only overflow case. */
638 if (neg_double (lnum
, hnum
, &lnum
, &hnum
)
639 && ((HOST_WIDE_INT
) lden
& hden
) == -1)
645 neg_double (lden
, hden
, &lden
, &hden
);
649 if (hnum
== 0 && hden
== 0)
650 { /* single precision */
652 /* This unsigned division rounds toward zero. */
658 { /* trivial case: dividend < divisor */
659 /* hden != 0 already checked. */
666 memset (quo
, 0, sizeof quo
);
668 memset (num
, 0, sizeof num
); /* to zero 9th element */
669 memset (den
, 0, sizeof den
);
671 encode (num
, lnum
, hnum
);
672 encode (den
, lden
, hden
);
674 /* Special code for when the divisor < BASE. */
675 if (hden
== 0 && lden
< (unsigned HOST_WIDE_INT
) BASE
)
677 /* hnum != 0 already checked. */
678 for (i
= 4 - 1; i
>= 0; i
--)
680 work
= num
[i
] + carry
* BASE
;
681 quo
[i
] = work
/ lden
;
687 /* Full double precision division,
688 with thanks to Don Knuth's "Seminumerical Algorithms". */
689 int num_hi_sig
, den_hi_sig
;
690 unsigned HOST_WIDE_INT quo_est
, scale
;
692 /* Find the highest nonzero divisor digit. */
693 for (i
= 4 - 1;; i
--)
700 /* Insure that the first digit of the divisor is at least BASE/2.
701 This is required by the quotient digit estimation algorithm. */
703 scale
= BASE
/ (den
[den_hi_sig
] + 1);
705 { /* scale divisor and dividend */
707 for (i
= 0; i
<= 4 - 1; i
++)
709 work
= (num
[i
] * scale
) + carry
;
710 num
[i
] = LOWPART (work
);
711 carry
= HIGHPART (work
);
716 for (i
= 0; i
<= 4 - 1; i
++)
718 work
= (den
[i
] * scale
) + carry
;
719 den
[i
] = LOWPART (work
);
720 carry
= HIGHPART (work
);
721 if (den
[i
] != 0) den_hi_sig
= i
;
728 for (i
= num_hi_sig
- den_hi_sig
- 1; i
>= 0; i
--)
730 /* Guess the next quotient digit, quo_est, by dividing the first
731 two remaining dividend digits by the high order quotient digit.
732 quo_est is never low and is at most 2 high. */
733 unsigned HOST_WIDE_INT tmp
;
735 num_hi_sig
= i
+ den_hi_sig
+ 1;
736 work
= num
[num_hi_sig
] * BASE
+ num
[num_hi_sig
- 1];
737 if (num
[num_hi_sig
] != den
[den_hi_sig
])
738 quo_est
= work
/ den
[den_hi_sig
];
742 /* Refine quo_est so it's usually correct, and at most one high. */
743 tmp
= work
- quo_est
* den
[den_hi_sig
];
745 && (den
[den_hi_sig
- 1] * quo_est
746 > (tmp
* BASE
+ num
[num_hi_sig
- 2])))
749 /* Try QUO_EST as the quotient digit, by multiplying the
750 divisor by QUO_EST and subtracting from the remaining dividend.
751 Keep in mind that QUO_EST is the I - 1st digit. */
754 for (j
= 0; j
<= den_hi_sig
; j
++)
756 work
= quo_est
* den
[j
] + carry
;
757 carry
= HIGHPART (work
);
758 work
= num
[i
+ j
] - LOWPART (work
);
759 num
[i
+ j
] = LOWPART (work
);
760 carry
+= HIGHPART (work
) != 0;
763 /* If quo_est was high by one, then num[i] went negative and
764 we need to correct things. */
765 if (num
[num_hi_sig
] < (HOST_WIDE_INT
) carry
)
768 carry
= 0; /* add divisor back in */
769 for (j
= 0; j
<= den_hi_sig
; j
++)
771 work
= num
[i
+ j
] + den
[j
] + carry
;
772 carry
= HIGHPART (work
);
773 num
[i
+ j
] = LOWPART (work
);
776 num
[num_hi_sig
] += carry
;
779 /* Store the quotient digit. */
784 decode (quo
, lquo
, hquo
);
787 /* If result is negative, make it so. */
789 neg_double (*lquo
, *hquo
, lquo
, hquo
);
791 /* Compute trial remainder: rem = num - (quo * den) */
792 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
793 neg_double (*lrem
, *hrem
, lrem
, hrem
);
794 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
799 case TRUNC_MOD_EXPR
: /* round toward zero */
800 case EXACT_DIV_EXPR
: /* for this one, it shouldn't matter */
804 case FLOOR_MOD_EXPR
: /* round toward negative infinity */
805 if (quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio < 0 && rem != 0 */
808 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1,
816 case CEIL_MOD_EXPR
: /* round toward positive infinity */
817 if (!quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio > 0 && rem != 0 */
819 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
827 case ROUND_MOD_EXPR
: /* round to closest integer */
829 unsigned HOST_WIDE_INT labs_rem
= *lrem
;
830 HOST_WIDE_INT habs_rem
= *hrem
;
831 unsigned HOST_WIDE_INT labs_den
= lden
, ltwice
;
832 HOST_WIDE_INT habs_den
= hden
, htwice
;
834 /* Get absolute values. */
836 neg_double (*lrem
, *hrem
, &labs_rem
, &habs_rem
);
838 neg_double (lden
, hden
, &labs_den
, &habs_den
);
840 /* If (2 * abs (lrem) >= abs (lden)) */
841 mul_double ((HOST_WIDE_INT
) 2, (HOST_WIDE_INT
) 0,
842 labs_rem
, habs_rem
, <wice
, &htwice
);
844 if (((unsigned HOST_WIDE_INT
) habs_den
845 < (unsigned HOST_WIDE_INT
) htwice
)
846 || (((unsigned HOST_WIDE_INT
) habs_den
847 == (unsigned HOST_WIDE_INT
) htwice
)
848 && (labs_den
< ltwice
)))
852 add_double (*lquo
, *hquo
,
853 (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1, lquo
, hquo
);
856 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
868 /* Compute true remainder: rem = num - (quo * den) */
869 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
870 neg_double (*lrem
, *hrem
, lrem
, hrem
);
871 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
875 /* If ARG2 divides ARG1 with zero remainder, carries out the division
876 of type CODE and returns the quotient.
877 Otherwise returns NULL_TREE. */
880 div_if_zero_remainder (enum tree_code code
, tree arg1
, tree arg2
)
882 unsigned HOST_WIDE_INT int1l
, int2l
;
883 HOST_WIDE_INT int1h
, int2h
;
884 unsigned HOST_WIDE_INT quol
, reml
;
885 HOST_WIDE_INT quoh
, remh
;
886 tree type
= TREE_TYPE (arg1
);
887 int uns
= TYPE_UNSIGNED (type
);
889 int1l
= TREE_INT_CST_LOW (arg1
);
890 int1h
= TREE_INT_CST_HIGH (arg1
);
891 /* &obj[0] + -128 really should be compiled as &obj[-8] rather than
892 &obj[some_exotic_number]. */
893 if (POINTER_TYPE_P (type
))
896 type
= signed_type_for (type
);
897 fit_double_type (int1l
, int1h
, &int1l
, &int1h
,
901 fit_double_type (int1l
, int1h
, &int1l
, &int1h
, type
);
902 int2l
= TREE_INT_CST_LOW (arg2
);
903 int2h
= TREE_INT_CST_HIGH (arg2
);
905 div_and_round_double (code
, uns
, int1l
, int1h
, int2l
, int2h
,
906 &quol
, &quoh
, &reml
, &remh
);
907 if (remh
!= 0 || reml
!= 0)
910 return build_int_cst_wide (type
, quol
, quoh
);
913 /* This is nonzero if we should defer warnings about undefined
914 overflow. This facility exists because these warnings are a
915 special case. The code to estimate loop iterations does not want
916 to issue any warnings, since it works with expressions which do not
917 occur in user code. Various bits of cleanup code call fold(), but
918 only use the result if it has certain characteristics (e.g., is a
919 constant); that code only wants to issue a warning if the result is
922 static int fold_deferring_overflow_warnings
;
924 /* If a warning about undefined overflow is deferred, this is the
925 warning. Note that this may cause us to turn two warnings into
926 one, but that is fine since it is sufficient to only give one
927 warning per expression. */
929 static const char* fold_deferred_overflow_warning
;
931 /* If a warning about undefined overflow is deferred, this is the
932 level at which the warning should be emitted. */
934 static enum warn_strict_overflow_code fold_deferred_overflow_code
;
936 /* Start deferring overflow warnings. We could use a stack here to
937 permit nested calls, but at present it is not necessary. */
940 fold_defer_overflow_warnings (void)
942 ++fold_deferring_overflow_warnings
;
945 /* Stop deferring overflow warnings. If there is a pending warning,
946 and ISSUE is true, then issue the warning if appropriate. STMT is
947 the statement with which the warning should be associated (used for
948 location information); STMT may be NULL. CODE is the level of the
949 warning--a warn_strict_overflow_code value. This function will use
950 the smaller of CODE and the deferred code when deciding whether to
951 issue the warning. CODE may be zero to mean to always use the
955 fold_undefer_overflow_warnings (bool issue
, tree stmt
, int code
)
960 gcc_assert (fold_deferring_overflow_warnings
> 0);
961 --fold_deferring_overflow_warnings
;
962 if (fold_deferring_overflow_warnings
> 0)
964 if (fold_deferred_overflow_warning
!= NULL
966 && code
< (int) fold_deferred_overflow_code
)
967 fold_deferred_overflow_code
= code
;
971 warnmsg
= fold_deferred_overflow_warning
;
972 fold_deferred_overflow_warning
= NULL
;
974 if (!issue
|| warnmsg
== NULL
)
977 /* Use the smallest code level when deciding to issue the
979 if (code
== 0 || code
> (int) fold_deferred_overflow_code
)
980 code
= fold_deferred_overflow_code
;
982 if (!issue_strict_overflow_warning (code
))
985 if (stmt
== NULL_TREE
|| !expr_has_location (stmt
))
986 locus
= input_location
;
988 locus
= expr_location (stmt
);
989 warning (OPT_Wstrict_overflow
, "%H%s", &locus
, warnmsg
);
992 /* Stop deferring overflow warnings, ignoring any deferred
996 fold_undefer_and_ignore_overflow_warnings (void)
998 fold_undefer_overflow_warnings (false, NULL_TREE
, 0);
1001 /* Whether we are deferring overflow warnings. */
1004 fold_deferring_overflow_warnings_p (void)
1006 return fold_deferring_overflow_warnings
> 0;
1009 /* This is called when we fold something based on the fact that signed
1010 overflow is undefined. */
1013 fold_overflow_warning (const char* gmsgid
, enum warn_strict_overflow_code wc
)
1015 gcc_assert (!flag_wrapv
&& !flag_trapv
);
1016 if (fold_deferring_overflow_warnings
> 0)
1018 if (fold_deferred_overflow_warning
== NULL
1019 || wc
< fold_deferred_overflow_code
)
1021 fold_deferred_overflow_warning
= gmsgid
;
1022 fold_deferred_overflow_code
= wc
;
1025 else if (issue_strict_overflow_warning (wc
))
1026 warning (OPT_Wstrict_overflow
, gmsgid
);
1029 /* Return true if the built-in mathematical function specified by CODE
1030 is odd, i.e. -f(x) == f(-x). */
1033 negate_mathfn_p (enum built_in_function code
)
1037 CASE_FLT_FN (BUILT_IN_ASIN
):
1038 CASE_FLT_FN (BUILT_IN_ASINH
):
1039 CASE_FLT_FN (BUILT_IN_ATAN
):
1040 CASE_FLT_FN (BUILT_IN_ATANH
):
1041 CASE_FLT_FN (BUILT_IN_CASIN
):
1042 CASE_FLT_FN (BUILT_IN_CASINH
):
1043 CASE_FLT_FN (BUILT_IN_CATAN
):
1044 CASE_FLT_FN (BUILT_IN_CATANH
):
1045 CASE_FLT_FN (BUILT_IN_CBRT
):
1046 CASE_FLT_FN (BUILT_IN_CPROJ
):
1047 CASE_FLT_FN (BUILT_IN_CSIN
):
1048 CASE_FLT_FN (BUILT_IN_CSINH
):
1049 CASE_FLT_FN (BUILT_IN_CTAN
):
1050 CASE_FLT_FN (BUILT_IN_CTANH
):
1051 CASE_FLT_FN (BUILT_IN_ERF
):
1052 CASE_FLT_FN (BUILT_IN_LLROUND
):
1053 CASE_FLT_FN (BUILT_IN_LROUND
):
1054 CASE_FLT_FN (BUILT_IN_ROUND
):
1055 CASE_FLT_FN (BUILT_IN_SIN
):
1056 CASE_FLT_FN (BUILT_IN_SINH
):
1057 CASE_FLT_FN (BUILT_IN_TAN
):
1058 CASE_FLT_FN (BUILT_IN_TANH
):
1059 CASE_FLT_FN (BUILT_IN_TRUNC
):
1062 CASE_FLT_FN (BUILT_IN_LLRINT
):
1063 CASE_FLT_FN (BUILT_IN_LRINT
):
1064 CASE_FLT_FN (BUILT_IN_NEARBYINT
):
1065 CASE_FLT_FN (BUILT_IN_RINT
):
1066 return !flag_rounding_math
;
1074 /* Check whether we may negate an integer constant T without causing
1078 may_negate_without_overflow_p (const_tree t
)
1080 unsigned HOST_WIDE_INT val
;
1084 gcc_assert (TREE_CODE (t
) == INTEGER_CST
);
1086 type
= TREE_TYPE (t
);
1087 if (TYPE_UNSIGNED (type
))
1090 prec
= TYPE_PRECISION (type
);
1091 if (prec
> HOST_BITS_PER_WIDE_INT
)
1093 if (TREE_INT_CST_LOW (t
) != 0)
1095 prec
-= HOST_BITS_PER_WIDE_INT
;
1096 val
= TREE_INT_CST_HIGH (t
);
1099 val
= TREE_INT_CST_LOW (t
);
1100 if (prec
< HOST_BITS_PER_WIDE_INT
)
1101 val
&= ((unsigned HOST_WIDE_INT
) 1 << prec
) - 1;
1102 return val
!= ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1));
1105 /* Determine whether an expression T can be cheaply negated using
1106 the function negate_expr without introducing undefined overflow. */
1109 negate_expr_p (tree t
)
1116 type
= TREE_TYPE (t
);
1118 STRIP_SIGN_NOPS (t
);
1119 switch (TREE_CODE (t
))
1122 if (TYPE_OVERFLOW_WRAPS (type
))
1125 /* Check that -CST will not overflow type. */
1126 return may_negate_without_overflow_p (t
);
1128 return (INTEGRAL_TYPE_P (type
)
1129 && TYPE_OVERFLOW_WRAPS (type
));
1137 return negate_expr_p (TREE_REALPART (t
))
1138 && negate_expr_p (TREE_IMAGPART (t
));
1141 return negate_expr_p (TREE_OPERAND (t
, 0))
1142 && negate_expr_p (TREE_OPERAND (t
, 1));
1145 return negate_expr_p (TREE_OPERAND (t
, 0));
1148 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type
))
1149 || HONOR_SIGNED_ZEROS (TYPE_MODE (type
)))
1151 /* -(A + B) -> (-B) - A. */
1152 if (negate_expr_p (TREE_OPERAND (t
, 1))
1153 && reorder_operands_p (TREE_OPERAND (t
, 0),
1154 TREE_OPERAND (t
, 1)))
1156 /* -(A + B) -> (-A) - B. */
1157 return negate_expr_p (TREE_OPERAND (t
, 0));
1160 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
1161 return !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type
))
1162 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type
))
1163 && reorder_operands_p (TREE_OPERAND (t
, 0),
1164 TREE_OPERAND (t
, 1));
1167 if (TYPE_UNSIGNED (TREE_TYPE (t
)))
1173 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t
))))
1174 return negate_expr_p (TREE_OPERAND (t
, 1))
1175 || negate_expr_p (TREE_OPERAND (t
, 0));
1178 case TRUNC_DIV_EXPR
:
1179 case ROUND_DIV_EXPR
:
1180 case FLOOR_DIV_EXPR
:
1182 case EXACT_DIV_EXPR
:
1183 /* In general we can't negate A / B, because if A is INT_MIN and
1184 B is 1, we may turn this into INT_MIN / -1 which is undefined
1185 and actually traps on some architectures. But if overflow is
1186 undefined, we can negate, because - (INT_MIN / 1) is an
1188 if (INTEGRAL_TYPE_P (TREE_TYPE (t
))
1189 && !TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t
)))
1191 return negate_expr_p (TREE_OPERAND (t
, 1))
1192 || negate_expr_p (TREE_OPERAND (t
, 0));
1195 /* Negate -((double)float) as (double)(-float). */
1196 if (TREE_CODE (type
) == REAL_TYPE
)
1198 tree tem
= strip_float_extensions (t
);
1200 return negate_expr_p (tem
);
1205 /* Negate -f(x) as f(-x). */
1206 if (negate_mathfn_p (builtin_mathfn_code (t
)))
1207 return negate_expr_p (CALL_EXPR_ARG (t
, 0));
1211 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1212 if (TREE_CODE (TREE_OPERAND (t
, 1)) == INTEGER_CST
)
1214 tree op1
= TREE_OPERAND (t
, 1);
1215 if (TREE_INT_CST_HIGH (op1
) == 0
1216 && (unsigned HOST_WIDE_INT
) (TYPE_PRECISION (type
) - 1)
1217 == TREE_INT_CST_LOW (op1
))
1228 /* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
1229 simplification is possible.
1230 If negate_expr_p would return true for T, NULL_TREE will never be
1234 fold_negate_expr (tree t
)
1236 tree type
= TREE_TYPE (t
);
1239 switch (TREE_CODE (t
))
1241 /* Convert - (~A) to A + 1. */
1243 if (INTEGRAL_TYPE_P (type
))
1244 return fold_build2 (PLUS_EXPR
, type
, TREE_OPERAND (t
, 0),
1245 build_int_cst (type
, 1));
1249 tem
= fold_negate_const (t
, type
);
1250 if (TREE_OVERFLOW (tem
) == TREE_OVERFLOW (t
)
1251 || !TYPE_OVERFLOW_TRAPS (type
))
1256 tem
= fold_negate_const (t
, type
);
1257 /* Two's complement FP formats, such as c4x, may overflow. */
1258 if (!TREE_OVERFLOW (tem
) || !flag_trapping_math
)
1263 tem
= fold_negate_const (t
, type
);
1268 tree rpart
= negate_expr (TREE_REALPART (t
));
1269 tree ipart
= negate_expr (TREE_IMAGPART (t
));
1271 if ((TREE_CODE (rpart
) == REAL_CST
1272 && TREE_CODE (ipart
) == REAL_CST
)
1273 || (TREE_CODE (rpart
) == INTEGER_CST
1274 && TREE_CODE (ipart
) == INTEGER_CST
))
1275 return build_complex (type
, rpart
, ipart
);
1280 if (negate_expr_p (t
))
1281 return fold_build2 (COMPLEX_EXPR
, type
,
1282 fold_negate_expr (TREE_OPERAND (t
, 0)),
1283 fold_negate_expr (TREE_OPERAND (t
, 1)));
1287 if (negate_expr_p (t
))
1288 return fold_build1 (CONJ_EXPR
, type
,
1289 fold_negate_expr (TREE_OPERAND (t
, 0)));
1293 return TREE_OPERAND (t
, 0);
1296 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type
))
1297 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type
)))
1299 /* -(A + B) -> (-B) - A. */
1300 if (negate_expr_p (TREE_OPERAND (t
, 1))
1301 && reorder_operands_p (TREE_OPERAND (t
, 0),
1302 TREE_OPERAND (t
, 1)))
1304 tem
= negate_expr (TREE_OPERAND (t
, 1));
1305 return fold_build2 (MINUS_EXPR
, type
,
1306 tem
, TREE_OPERAND (t
, 0));
1309 /* -(A + B) -> (-A) - B. */
1310 if (negate_expr_p (TREE_OPERAND (t
, 0)))
1312 tem
= negate_expr (TREE_OPERAND (t
, 0));
1313 return fold_build2 (MINUS_EXPR
, type
,
1314 tem
, TREE_OPERAND (t
, 1));
1320 /* - (A - B) -> B - A */
1321 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type
))
1322 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type
))
1323 && reorder_operands_p (TREE_OPERAND (t
, 0), TREE_OPERAND (t
, 1)))
1324 return fold_build2 (MINUS_EXPR
, type
,
1325 TREE_OPERAND (t
, 1), TREE_OPERAND (t
, 0));
1329 if (TYPE_UNSIGNED (type
))
1335 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type
)))
1337 tem
= TREE_OPERAND (t
, 1);
1338 if (negate_expr_p (tem
))
1339 return fold_build2 (TREE_CODE (t
), type
,
1340 TREE_OPERAND (t
, 0), negate_expr (tem
));
1341 tem
= TREE_OPERAND (t
, 0);
1342 if (negate_expr_p (tem
))
1343 return fold_build2 (TREE_CODE (t
), type
,
1344 negate_expr (tem
), TREE_OPERAND (t
, 1));
1348 case TRUNC_DIV_EXPR
:
1349 case ROUND_DIV_EXPR
:
1350 case FLOOR_DIV_EXPR
:
1352 case EXACT_DIV_EXPR
:
1353 /* In general we can't negate A / B, because if A is INT_MIN and
1354 B is 1, we may turn this into INT_MIN / -1 which is undefined
1355 and actually traps on some architectures. But if overflow is
1356 undefined, we can negate, because - (INT_MIN / 1) is an
1358 if (!INTEGRAL_TYPE_P (type
) || TYPE_OVERFLOW_UNDEFINED (type
))
1360 const char * const warnmsg
= G_("assuming signed overflow does not "
1361 "occur when negating a division");
1362 tem
= TREE_OPERAND (t
, 1);
1363 if (negate_expr_p (tem
))
1365 if (INTEGRAL_TYPE_P (type
)
1366 && (TREE_CODE (tem
) != INTEGER_CST
1367 || integer_onep (tem
)))
1368 fold_overflow_warning (warnmsg
, WARN_STRICT_OVERFLOW_MISC
);
1369 return fold_build2 (TREE_CODE (t
), type
,
1370 TREE_OPERAND (t
, 0), negate_expr (tem
));
1372 tem
= TREE_OPERAND (t
, 0);
1373 if (negate_expr_p (tem
))
1375 if (INTEGRAL_TYPE_P (type
)
1376 && (TREE_CODE (tem
) != INTEGER_CST
1377 || tree_int_cst_equal (tem
, TYPE_MIN_VALUE (type
))))
1378 fold_overflow_warning (warnmsg
, WARN_STRICT_OVERFLOW_MISC
);
1379 return fold_build2 (TREE_CODE (t
), type
,
1380 negate_expr (tem
), TREE_OPERAND (t
, 1));
1386 /* Convert -((double)float) into (double)(-float). */
1387 if (TREE_CODE (type
) == REAL_TYPE
)
1389 tem
= strip_float_extensions (t
);
1390 if (tem
!= t
&& negate_expr_p (tem
))
1391 return fold_convert (type
, negate_expr (tem
));
1396 /* Negate -f(x) as f(-x). */
1397 if (negate_mathfn_p (builtin_mathfn_code (t
))
1398 && negate_expr_p (CALL_EXPR_ARG (t
, 0)))
1402 fndecl
= get_callee_fndecl (t
);
1403 arg
= negate_expr (CALL_EXPR_ARG (t
, 0));
1404 return build_call_expr (fndecl
, 1, arg
);
1409 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1410 if (TREE_CODE (TREE_OPERAND (t
, 1)) == INTEGER_CST
)
1412 tree op1
= TREE_OPERAND (t
, 1);
1413 if (TREE_INT_CST_HIGH (op1
) == 0
1414 && (unsigned HOST_WIDE_INT
) (TYPE_PRECISION (type
) - 1)
1415 == TREE_INT_CST_LOW (op1
))
1417 tree ntype
= TYPE_UNSIGNED (type
)
1418 ? signed_type_for (type
)
1419 : unsigned_type_for (type
);
1420 tree temp
= fold_convert (ntype
, TREE_OPERAND (t
, 0));
1421 temp
= fold_build2 (RSHIFT_EXPR
, ntype
, temp
, op1
);
1422 return fold_convert (type
, temp
);
1434 /* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T can not be
1435 negated in a simpler way. Also allow for T to be NULL_TREE, in which case
1436 return NULL_TREE. */
1439 negate_expr (tree t
)
1446 type
= TREE_TYPE (t
);
1447 STRIP_SIGN_NOPS (t
);
1449 tem
= fold_negate_expr (t
);
1451 tem
= build1 (NEGATE_EXPR
, TREE_TYPE (t
), t
);
1452 return fold_convert (type
, tem
);
1455 /* Split a tree IN into a constant, literal and variable parts that could be
1456 combined with CODE to make IN. "constant" means an expression with
1457 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1458 commutative arithmetic operation. Store the constant part into *CONP,
1459 the literal in *LITP and return the variable part. If a part isn't
1460 present, set it to null. If the tree does not decompose in this way,
1461 return the entire tree as the variable part and the other parts as null.
1463 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1464 case, we negate an operand that was subtracted. Except if it is a
1465 literal for which we use *MINUS_LITP instead.
1467 If NEGATE_P is true, we are negating all of IN, again except a literal
1468 for which we use *MINUS_LITP instead.
1470 If IN is itself a literal or constant, return it as appropriate.
1472 Note that we do not guarantee that any of the three values will be the
1473 same type as IN, but they will have the same signedness and mode. */
1476 split_tree (tree in
, enum tree_code code
, tree
*conp
, tree
*litp
,
1477 tree
*minus_litp
, int negate_p
)
1485 /* Strip any conversions that don't change the machine mode or signedness. */
1486 STRIP_SIGN_NOPS (in
);
1488 if (TREE_CODE (in
) == INTEGER_CST
|| TREE_CODE (in
) == REAL_CST
1489 || TREE_CODE (in
) == FIXED_CST
)
1491 else if (TREE_CODE (in
) == code
1492 || (! FLOAT_TYPE_P (TREE_TYPE (in
))
1493 && ! SAT_FIXED_POINT_TYPE_P (TREE_TYPE (in
))
1494 /* We can associate addition and subtraction together (even
1495 though the C standard doesn't say so) for integers because
1496 the value is not affected. For reals, the value might be
1497 affected, so we can't. */
1498 && ((code
== PLUS_EXPR
&& TREE_CODE (in
) == MINUS_EXPR
)
1499 || (code
== MINUS_EXPR
&& TREE_CODE (in
) == PLUS_EXPR
))))
1501 tree op0
= TREE_OPERAND (in
, 0);
1502 tree op1
= TREE_OPERAND (in
, 1);
1503 int neg1_p
= TREE_CODE (in
) == MINUS_EXPR
;
1504 int neg_litp_p
= 0, neg_conp_p
= 0, neg_var_p
= 0;
1506 /* First see if either of the operands is a literal, then a constant. */
1507 if (TREE_CODE (op0
) == INTEGER_CST
|| TREE_CODE (op0
) == REAL_CST
1508 || TREE_CODE (op0
) == FIXED_CST
)
1509 *litp
= op0
, op0
= 0;
1510 else if (TREE_CODE (op1
) == INTEGER_CST
|| TREE_CODE (op1
) == REAL_CST
1511 || TREE_CODE (op1
) == FIXED_CST
)
1512 *litp
= op1
, neg_litp_p
= neg1_p
, op1
= 0;
1514 if (op0
!= 0 && TREE_CONSTANT (op0
))
1515 *conp
= op0
, op0
= 0;
1516 else if (op1
!= 0 && TREE_CONSTANT (op1
))
1517 *conp
= op1
, neg_conp_p
= neg1_p
, op1
= 0;
1519 /* If we haven't dealt with either operand, this is not a case we can
1520 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1521 if (op0
!= 0 && op1
!= 0)
1526 var
= op1
, neg_var_p
= neg1_p
;
1528 /* Now do any needed negations. */
1530 *minus_litp
= *litp
, *litp
= 0;
1532 *conp
= negate_expr (*conp
);
1534 var
= negate_expr (var
);
1536 else if (TREE_CONSTANT (in
))
1544 *minus_litp
= *litp
, *litp
= 0;
1545 else if (*minus_litp
)
1546 *litp
= *minus_litp
, *minus_litp
= 0;
1547 *conp
= negate_expr (*conp
);
1548 var
= negate_expr (var
);
1554 /* Re-associate trees split by the above function. T1 and T2 are either
1555 expressions to associate or null. Return the new expression, if any. If
1556 we build an operation, do it in TYPE and with CODE. */
1559 associate_trees (tree t1
, tree t2
, enum tree_code code
, tree type
)
1566 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1567 try to fold this since we will have infinite recursion. But do
1568 deal with any NEGATE_EXPRs. */
1569 if (TREE_CODE (t1
) == code
|| TREE_CODE (t2
) == code
1570 || TREE_CODE (t1
) == MINUS_EXPR
|| TREE_CODE (t2
) == MINUS_EXPR
)
1572 if (code
== PLUS_EXPR
)
1574 if (TREE_CODE (t1
) == NEGATE_EXPR
)
1575 return build2 (MINUS_EXPR
, type
, fold_convert (type
, t2
),
1576 fold_convert (type
, TREE_OPERAND (t1
, 0)));
1577 else if (TREE_CODE (t2
) == NEGATE_EXPR
)
1578 return build2 (MINUS_EXPR
, type
, fold_convert (type
, t1
),
1579 fold_convert (type
, TREE_OPERAND (t2
, 0)));
1580 else if (integer_zerop (t2
))
1581 return fold_convert (type
, t1
);
1583 else if (code
== MINUS_EXPR
)
1585 if (integer_zerop (t2
))
1586 return fold_convert (type
, t1
);
1589 return build2 (code
, type
, fold_convert (type
, t1
),
1590 fold_convert (type
, t2
));
1593 return fold_build2 (code
, type
, fold_convert (type
, t1
),
1594 fold_convert (type
, t2
));
1597 /* Check whether TYPE1 and TYPE2 are equivalent integer types, suitable
1598 for use in int_const_binop, size_binop and size_diffop. */
1601 int_binop_types_match_p (enum tree_code code
, tree type1
, tree type2
)
1603 if (TREE_CODE (type1
) != INTEGER_TYPE
&& !POINTER_TYPE_P (type1
))
1605 if (TREE_CODE (type2
) != INTEGER_TYPE
&& !POINTER_TYPE_P (type2
))
1620 return TYPE_UNSIGNED (type1
) == TYPE_UNSIGNED (type2
)
1621 && TYPE_PRECISION (type1
) == TYPE_PRECISION (type2
)
1622 && TYPE_MODE (type1
) == TYPE_MODE (type2
);
1626 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1627 to produce a new constant. Return NULL_TREE if we don't know how
1628 to evaluate CODE at compile-time.
1630 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1633 int_const_binop (enum tree_code code
, const_tree arg1
, const_tree arg2
, int notrunc
)
1635 unsigned HOST_WIDE_INT int1l
, int2l
;
1636 HOST_WIDE_INT int1h
, int2h
;
1637 unsigned HOST_WIDE_INT low
;
1639 unsigned HOST_WIDE_INT garbagel
;
1640 HOST_WIDE_INT garbageh
;
1642 tree type
= TREE_TYPE (arg1
);
1643 int uns
= TYPE_UNSIGNED (type
);
1645 = (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
));
1648 int1l
= TREE_INT_CST_LOW (arg1
);
1649 int1h
= TREE_INT_CST_HIGH (arg1
);
1650 int2l
= TREE_INT_CST_LOW (arg2
);
1651 int2h
= TREE_INT_CST_HIGH (arg2
);
1656 low
= int1l
| int2l
, hi
= int1h
| int2h
;
1660 low
= int1l
^ int2l
, hi
= int1h
^ int2h
;
1664 low
= int1l
& int2l
, hi
= int1h
& int2h
;
1670 /* It's unclear from the C standard whether shifts can overflow.
1671 The following code ignores overflow; perhaps a C standard
1672 interpretation ruling is needed. */
1673 lshift_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1680 lrotate_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1685 overflow
= add_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1689 neg_double (int2l
, int2h
, &low
, &hi
);
1690 add_double (int1l
, int1h
, low
, hi
, &low
, &hi
);
1691 overflow
= OVERFLOW_SUM_SIGN (hi
, int2h
, int1h
);
1695 overflow
= mul_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1698 case TRUNC_DIV_EXPR
:
1699 case FLOOR_DIV_EXPR
: case CEIL_DIV_EXPR
:
1700 case EXACT_DIV_EXPR
:
1701 /* This is a shortcut for a common special case. */
1702 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1703 && !TREE_OVERFLOW (arg1
)
1704 && !TREE_OVERFLOW (arg2
)
1705 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1707 if (code
== CEIL_DIV_EXPR
)
1710 low
= int1l
/ int2l
, hi
= 0;
1714 /* ... fall through ... */
1716 case ROUND_DIV_EXPR
:
1717 if (int2h
== 0 && int2l
== 0)
1719 if (int2h
== 0 && int2l
== 1)
1721 low
= int1l
, hi
= int1h
;
1724 if (int1l
== int2l
&& int1h
== int2h
1725 && ! (int1l
== 0 && int1h
== 0))
1730 overflow
= div_and_round_double (code
, uns
, int1l
, int1h
, int2l
, int2h
,
1731 &low
, &hi
, &garbagel
, &garbageh
);
1734 case TRUNC_MOD_EXPR
:
1735 case FLOOR_MOD_EXPR
: case CEIL_MOD_EXPR
:
1736 /* This is a shortcut for a common special case. */
1737 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1738 && !TREE_OVERFLOW (arg1
)
1739 && !TREE_OVERFLOW (arg2
)
1740 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1742 if (code
== CEIL_MOD_EXPR
)
1744 low
= int1l
% int2l
, hi
= 0;
1748 /* ... fall through ... */
1750 case ROUND_MOD_EXPR
:
1751 if (int2h
== 0 && int2l
== 0)
1753 overflow
= div_and_round_double (code
, uns
,
1754 int1l
, int1h
, int2l
, int2h
,
1755 &garbagel
, &garbageh
, &low
, &hi
);
1761 low
= (((unsigned HOST_WIDE_INT
) int1h
1762 < (unsigned HOST_WIDE_INT
) int2h
)
1763 || (((unsigned HOST_WIDE_INT
) int1h
1764 == (unsigned HOST_WIDE_INT
) int2h
)
1767 low
= (int1h
< int2h
1768 || (int1h
== int2h
&& int1l
< int2l
));
1770 if (low
== (code
== MIN_EXPR
))
1771 low
= int1l
, hi
= int1h
;
1773 low
= int2l
, hi
= int2h
;
1782 t
= build_int_cst_wide (TREE_TYPE (arg1
), low
, hi
);
1784 /* Propagate overflow flags ourselves. */
1785 if (((!uns
|| is_sizetype
) && overflow
)
1786 | TREE_OVERFLOW (arg1
) | TREE_OVERFLOW (arg2
))
1789 TREE_OVERFLOW (t
) = 1;
1793 t
= force_fit_type_double (TREE_TYPE (arg1
), low
, hi
, 1,
1794 ((!uns
|| is_sizetype
) && overflow
)
1795 | TREE_OVERFLOW (arg1
) | TREE_OVERFLOW (arg2
));
1800 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1801 constant. We assume ARG1 and ARG2 have the same data type, or at least
1802 are the same kind of constant and the same machine mode. Return zero if
1803 combining the constants is not allowed in the current operating mode.
1805 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1808 const_binop (enum tree_code code
, tree arg1
, tree arg2
, int notrunc
)
1810 /* Sanity check for the recursive cases. */
1817 if (TREE_CODE (arg1
) == INTEGER_CST
)
1818 return int_const_binop (code
, arg1
, arg2
, notrunc
);
1820 if (TREE_CODE (arg1
) == REAL_CST
)
1822 enum machine_mode mode
;
1825 REAL_VALUE_TYPE value
;
1826 REAL_VALUE_TYPE result
;
1830 /* The following codes are handled by real_arithmetic. */
1845 d1
= TREE_REAL_CST (arg1
);
1846 d2
= TREE_REAL_CST (arg2
);
1848 type
= TREE_TYPE (arg1
);
1849 mode
= TYPE_MODE (type
);
1851 /* Don't perform operation if we honor signaling NaNs and
1852 either operand is a NaN. */
1853 if (HONOR_SNANS (mode
)
1854 && (REAL_VALUE_ISNAN (d1
) || REAL_VALUE_ISNAN (d2
)))
1857 /* Don't perform operation if it would raise a division
1858 by zero exception. */
1859 if (code
== RDIV_EXPR
1860 && REAL_VALUES_EQUAL (d2
, dconst0
)
1861 && (flag_trapping_math
|| ! MODE_HAS_INFINITIES (mode
)))
1864 /* If either operand is a NaN, just return it. Otherwise, set up
1865 for floating-point trap; we return an overflow. */
1866 if (REAL_VALUE_ISNAN (d1
))
1868 else if (REAL_VALUE_ISNAN (d2
))
1871 inexact
= real_arithmetic (&value
, code
, &d1
, &d2
);
1872 real_convert (&result
, mode
, &value
);
1874 /* Don't constant fold this floating point operation if
1875 the result has overflowed and flag_trapping_math. */
1876 if (flag_trapping_math
1877 && MODE_HAS_INFINITIES (mode
)
1878 && REAL_VALUE_ISINF (result
)
1879 && !REAL_VALUE_ISINF (d1
)
1880 && !REAL_VALUE_ISINF (d2
))
1883 /* Don't constant fold this floating point operation if the
1884 result may dependent upon the run-time rounding mode and
1885 flag_rounding_math is set, or if GCC's software emulation
1886 is unable to accurately represent the result. */
1887 if ((flag_rounding_math
1888 || (REAL_MODE_FORMAT_COMPOSITE_P (mode
)
1889 && !flag_unsafe_math_optimizations
))
1890 && (inexact
|| !real_identical (&result
, &value
)))
1893 t
= build_real (type
, result
);
1895 TREE_OVERFLOW (t
) = TREE_OVERFLOW (arg1
) | TREE_OVERFLOW (arg2
);
1899 if (TREE_CODE (arg1
) == FIXED_CST
)
1901 FIXED_VALUE_TYPE f1
;
1902 FIXED_VALUE_TYPE f2
;
1903 FIXED_VALUE_TYPE result
;
1908 /* The following codes are handled by fixed_arithmetic. */
1914 case TRUNC_DIV_EXPR
:
1915 f2
= TREE_FIXED_CST (arg2
);
1920 f2
.data
.high
= TREE_INT_CST_HIGH (arg2
);
1921 f2
.data
.low
= TREE_INT_CST_LOW (arg2
);
1929 f1
= TREE_FIXED_CST (arg1
);
1930 type
= TREE_TYPE (arg1
);
1931 sat_p
= TYPE_SATURATING (type
);
1932 overflow_p
= fixed_arithmetic (&result
, code
, &f1
, &f2
, sat_p
);
1933 t
= build_fixed (type
, result
);
1934 /* Propagate overflow flags. */
1935 if (overflow_p
| TREE_OVERFLOW (arg1
) | TREE_OVERFLOW (arg2
))
1937 TREE_OVERFLOW (t
) = 1;
1938 TREE_CONSTANT_OVERFLOW (t
) = 1;
1940 else if (TREE_CONSTANT_OVERFLOW (arg1
) | TREE_CONSTANT_OVERFLOW (arg2
))
1941 TREE_CONSTANT_OVERFLOW (t
) = 1;
1945 if (TREE_CODE (arg1
) == COMPLEX_CST
)
1947 tree type
= TREE_TYPE (arg1
);
1948 tree r1
= TREE_REALPART (arg1
);
1949 tree i1
= TREE_IMAGPART (arg1
);
1950 tree r2
= TREE_REALPART (arg2
);
1951 tree i2
= TREE_IMAGPART (arg2
);
1958 real
= const_binop (code
, r1
, r2
, notrunc
);
1959 imag
= const_binop (code
, i1
, i2
, notrunc
);
1963 real
= const_binop (MINUS_EXPR
,
1964 const_binop (MULT_EXPR
, r1
, r2
, notrunc
),
1965 const_binop (MULT_EXPR
, i1
, i2
, notrunc
),
1967 imag
= const_binop (PLUS_EXPR
,
1968 const_binop (MULT_EXPR
, r1
, i2
, notrunc
),
1969 const_binop (MULT_EXPR
, i1
, r2
, notrunc
),
1976 = const_binop (PLUS_EXPR
,
1977 const_binop (MULT_EXPR
, r2
, r2
, notrunc
),
1978 const_binop (MULT_EXPR
, i2
, i2
, notrunc
),
1981 = const_binop (PLUS_EXPR
,
1982 const_binop (MULT_EXPR
, r1
, r2
, notrunc
),
1983 const_binop (MULT_EXPR
, i1
, i2
, notrunc
),
1986 = const_binop (MINUS_EXPR
,
1987 const_binop (MULT_EXPR
, i1
, r2
, notrunc
),
1988 const_binop (MULT_EXPR
, r1
, i2
, notrunc
),
1991 if (INTEGRAL_TYPE_P (TREE_TYPE (r1
)))
1992 code
= TRUNC_DIV_EXPR
;
1994 real
= const_binop (code
, t1
, magsquared
, notrunc
);
1995 imag
= const_binop (code
, t2
, magsquared
, notrunc
);
2004 return build_complex (type
, real
, imag
);
2010 /* Create a size type INT_CST node with NUMBER sign extended. KIND
2011 indicates which particular sizetype to create. */
2014 size_int_kind (HOST_WIDE_INT number
, enum size_type_kind kind
)
2016 return build_int_cst (sizetype_tab
[(int) kind
], number
);
2019 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
2020 is a tree code. The type of the result is taken from the operands.
2021 Both must be equivalent integer types, ala int_binop_types_match_p.
2022 If the operands are constant, so is the result. */
2025 size_binop (enum tree_code code
, tree arg0
, tree arg1
)
2027 tree type
= TREE_TYPE (arg0
);
2029 if (arg0
== error_mark_node
|| arg1
== error_mark_node
)
2030 return error_mark_node
;
2032 gcc_assert (int_binop_types_match_p (code
, TREE_TYPE (arg0
),
2035 /* Handle the special case of two integer constants faster. */
2036 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
2038 /* And some specific cases even faster than that. */
2039 if (code
== PLUS_EXPR
)
2041 if (integer_zerop (arg0
) && !TREE_OVERFLOW (arg0
))
2043 if (integer_zerop (arg1
) && !TREE_OVERFLOW (arg1
))
2046 else if (code
== MINUS_EXPR
)
2048 if (integer_zerop (arg1
) && !TREE_OVERFLOW (arg1
))
2051 else if (code
== MULT_EXPR
)
2053 if (integer_onep (arg0
) && !TREE_OVERFLOW (arg0
))
2057 /* Handle general case of two integer constants. */
2058 return int_const_binop (code
, arg0
, arg1
, 0);
2061 return fold_build2 (code
, type
, arg0
, arg1
);
2064 /* Given two values, either both of sizetype or both of bitsizetype,
2065 compute the difference between the two values. Return the value
2066 in signed type corresponding to the type of the operands. */
2069 size_diffop (tree arg0
, tree arg1
)
2071 tree type
= TREE_TYPE (arg0
);
2074 gcc_assert (int_binop_types_match_p (MINUS_EXPR
, TREE_TYPE (arg0
),
2077 /* If the type is already signed, just do the simple thing. */
2078 if (!TYPE_UNSIGNED (type
))
2079 return size_binop (MINUS_EXPR
, arg0
, arg1
);
2081 if (type
== sizetype
)
2083 else if (type
== bitsizetype
)
2084 ctype
= sbitsizetype
;
2086 ctype
= signed_type_for (type
);
2088 /* If either operand is not a constant, do the conversions to the signed
2089 type and subtract. The hardware will do the right thing with any
2090 overflow in the subtraction. */
2091 if (TREE_CODE (arg0
) != INTEGER_CST
|| TREE_CODE (arg1
) != INTEGER_CST
)
2092 return size_binop (MINUS_EXPR
, fold_convert (ctype
, arg0
),
2093 fold_convert (ctype
, arg1
));
2095 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
2096 Otherwise, subtract the other way, convert to CTYPE (we know that can't
2097 overflow) and negate (which can't either). Special-case a result
2098 of zero while we're here. */
2099 if (tree_int_cst_equal (arg0
, arg1
))
2100 return build_int_cst (ctype
, 0);
2101 else if (tree_int_cst_lt (arg1
, arg0
))
2102 return fold_convert (ctype
, size_binop (MINUS_EXPR
, arg0
, arg1
));
2104 return size_binop (MINUS_EXPR
, build_int_cst (ctype
, 0),
2105 fold_convert (ctype
, size_binop (MINUS_EXPR
,
2109 /* A subroutine of fold_convert_const handling conversions of an
2110 INTEGER_CST to another integer type. */
2113 fold_convert_const_int_from_int (tree type
, tree arg1
)
2117 /* Given an integer constant, make new constant with new type,
2118 appropriately sign-extended or truncated. */
2119 t
= force_fit_type_double (type
, TREE_INT_CST_LOW (arg1
),
2120 TREE_INT_CST_HIGH (arg1
),
2121 /* Don't set the overflow when
2122 converting a pointer */
2123 !POINTER_TYPE_P (TREE_TYPE (arg1
)),
2124 (TREE_INT_CST_HIGH (arg1
) < 0
2125 && (TYPE_UNSIGNED (type
)
2126 < TYPE_UNSIGNED (TREE_TYPE (arg1
))))
2127 | TREE_OVERFLOW (arg1
));
2132 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2133 to an integer type. */
2136 fold_convert_const_int_from_real (enum tree_code code
, tree type
, tree arg1
)
2141 /* The following code implements the floating point to integer
2142 conversion rules required by the Java Language Specification,
2143 that IEEE NaNs are mapped to zero and values that overflow
2144 the target precision saturate, i.e. values greater than
2145 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
2146 are mapped to INT_MIN. These semantics are allowed by the
2147 C and C++ standards that simply state that the behavior of
2148 FP-to-integer conversion is unspecified upon overflow. */
2150 HOST_WIDE_INT high
, low
;
2152 REAL_VALUE_TYPE x
= TREE_REAL_CST (arg1
);
2156 case FIX_TRUNC_EXPR
:
2157 real_trunc (&r
, VOIDmode
, &x
);
2164 /* If R is NaN, return zero and show we have an overflow. */
2165 if (REAL_VALUE_ISNAN (r
))
2172 /* See if R is less than the lower bound or greater than the
2177 tree lt
= TYPE_MIN_VALUE (type
);
2178 REAL_VALUE_TYPE l
= real_value_from_int_cst (NULL_TREE
, lt
);
2179 if (REAL_VALUES_LESS (r
, l
))
2182 high
= TREE_INT_CST_HIGH (lt
);
2183 low
= TREE_INT_CST_LOW (lt
);
2189 tree ut
= TYPE_MAX_VALUE (type
);
2192 REAL_VALUE_TYPE u
= real_value_from_int_cst (NULL_TREE
, ut
);
2193 if (REAL_VALUES_LESS (u
, r
))
2196 high
= TREE_INT_CST_HIGH (ut
);
2197 low
= TREE_INT_CST_LOW (ut
);
2203 REAL_VALUE_TO_INT (&low
, &high
, r
);
2205 t
= force_fit_type_double (type
, low
, high
, -1,
2206 overflow
| TREE_OVERFLOW (arg1
));
2210 /* A subroutine of fold_convert_const handling conversions of a
2211 FIXED_CST to an integer type. */
2214 fold_convert_const_int_from_fixed (tree type
, tree arg1
)
2217 double_int temp
, temp_trunc
;
2220 /* Right shift FIXED_CST to temp by fbit. */
2221 temp
= TREE_FIXED_CST (arg1
).data
;
2222 mode
= TREE_FIXED_CST (arg1
).mode
;
2223 if (GET_MODE_FBIT (mode
) < 2 * HOST_BITS_PER_WIDE_INT
)
2225 lshift_double (temp
.low
, temp
.high
,
2226 - GET_MODE_FBIT (mode
), 2 * HOST_BITS_PER_WIDE_INT
,
2227 &temp
.low
, &temp
.high
, SIGNED_FIXED_POINT_MODE_P (mode
));
2229 /* Left shift temp to temp_trunc by fbit. */
2230 lshift_double (temp
.low
, temp
.high
,
2231 GET_MODE_FBIT (mode
), 2 * HOST_BITS_PER_WIDE_INT
,
2232 &temp_trunc
.low
, &temp_trunc
.high
,
2233 SIGNED_FIXED_POINT_MODE_P (mode
));
2240 temp_trunc
.high
= 0;
2243 /* If FIXED_CST is negative, we need to round the value toward 0.
2244 By checking if the fractional bits are not zero to add 1 to temp. */
2245 if (SIGNED_FIXED_POINT_MODE_P (mode
) && temp_trunc
.high
< 0
2246 && !double_int_equal_p (TREE_FIXED_CST (arg1
).data
, temp_trunc
))
2251 temp
= double_int_add (temp
, one
);
2254 /* Given a fixed-point constant, make new constant with new type,
2255 appropriately sign-extended or truncated. */
2256 t
= force_fit_type_double (type
, temp
.low
, temp
.high
, -1,
2258 && (TYPE_UNSIGNED (type
)
2259 < TYPE_UNSIGNED (TREE_TYPE (arg1
))))
2260 | TREE_OVERFLOW (arg1
));
2265 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2266 to another floating point type. */
2269 fold_convert_const_real_from_real (tree type
, tree arg1
)
2271 REAL_VALUE_TYPE value
;
2274 real_convert (&value
, TYPE_MODE (type
), &TREE_REAL_CST (arg1
));
2275 t
= build_real (type
, value
);
2277 TREE_OVERFLOW (t
) = TREE_OVERFLOW (arg1
);
2281 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2282 to a floating point type. */
2285 fold_convert_const_real_from_fixed (tree type
, tree arg1
)
2287 REAL_VALUE_TYPE value
;
2290 real_convert_from_fixed (&value
, TYPE_MODE (type
), &TREE_FIXED_CST (arg1
));
2291 t
= build_real (type
, value
);
2293 TREE_OVERFLOW (t
) = TREE_OVERFLOW (arg1
);
2294 TREE_CONSTANT_OVERFLOW (t
)
2295 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
2299 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2300 to another fixed-point type. */
2303 fold_convert_const_fixed_from_fixed (tree type
, tree arg1
)
2305 FIXED_VALUE_TYPE value
;
2309 overflow_p
= fixed_convert (&value
, TYPE_MODE (type
), &TREE_FIXED_CST (arg1
),
2310 TYPE_SATURATING (type
));
2311 t
= build_fixed (type
, value
);
2313 /* Propagate overflow flags. */
2314 if (overflow_p
| TREE_OVERFLOW (arg1
))
2316 TREE_OVERFLOW (t
) = 1;
2317 TREE_CONSTANT_OVERFLOW (t
) = 1;
2319 else if (TREE_CONSTANT_OVERFLOW (arg1
))
2320 TREE_CONSTANT_OVERFLOW (t
) = 1;
2324 /* A subroutine of fold_convert_const handling conversions an INTEGER_CST
2325 to a fixed-point type. */
2328 fold_convert_const_fixed_from_int (tree type
, tree arg1
)
2330 FIXED_VALUE_TYPE value
;
2334 overflow_p
= fixed_convert_from_int (&value
, TYPE_MODE (type
),
2335 TREE_INT_CST (arg1
),
2336 TYPE_UNSIGNED (TREE_TYPE (arg1
)),
2337 TYPE_SATURATING (type
));
2338 t
= build_fixed (type
, value
);
2340 /* Propagate overflow flags. */
2341 if (overflow_p
| TREE_OVERFLOW (arg1
))
2343 TREE_OVERFLOW (t
) = 1;
2344 TREE_CONSTANT_OVERFLOW (t
) = 1;
2346 else if (TREE_CONSTANT_OVERFLOW (arg1
))
2347 TREE_CONSTANT_OVERFLOW (t
) = 1;
2351 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2352 to a fixed-point type. */
2355 fold_convert_const_fixed_from_real (tree type
, tree arg1
)
2357 FIXED_VALUE_TYPE value
;
2361 overflow_p
= fixed_convert_from_real (&value
, TYPE_MODE (type
),
2362 &TREE_REAL_CST (arg1
),
2363 TYPE_SATURATING (type
));
2364 t
= build_fixed (type
, value
);
2366 /* Propagate overflow flags. */
2367 if (overflow_p
| TREE_OVERFLOW (arg1
))
2369 TREE_OVERFLOW (t
) = 1;
2370 TREE_CONSTANT_OVERFLOW (t
) = 1;
2372 else if (TREE_CONSTANT_OVERFLOW (arg1
))
2373 TREE_CONSTANT_OVERFLOW (t
) = 1;
2377 /* Attempt to fold type conversion operation CODE of expression ARG1 to
2378 type TYPE. If no simplification can be done return NULL_TREE. */
2381 fold_convert_const (enum tree_code code
, tree type
, tree arg1
)
2383 if (TREE_TYPE (arg1
) == type
)
2386 if (POINTER_TYPE_P (type
) || INTEGRAL_TYPE_P (type
))
2388 if (TREE_CODE (arg1
) == INTEGER_CST
)
2389 return fold_convert_const_int_from_int (type
, arg1
);
2390 else if (TREE_CODE (arg1
) == REAL_CST
)
2391 return fold_convert_const_int_from_real (code
, type
, arg1
);
2392 else if (TREE_CODE (arg1
) == FIXED_CST
)
2393 return fold_convert_const_int_from_fixed (type
, arg1
);
2395 else if (TREE_CODE (type
) == REAL_TYPE
)
2397 if (TREE_CODE (arg1
) == INTEGER_CST
)
2398 return build_real_from_int_cst (type
, arg1
);
2399 else if (TREE_CODE (arg1
) == REAL_CST
)
2400 return fold_convert_const_real_from_real (type
, arg1
);
2401 else if (TREE_CODE (arg1
) == FIXED_CST
)
2402 return fold_convert_const_real_from_fixed (type
, arg1
);
2404 else if (TREE_CODE (type
) == FIXED_POINT_TYPE
)
2406 if (TREE_CODE (arg1
) == FIXED_CST
)
2407 return fold_convert_const_fixed_from_fixed (type
, arg1
);
2408 else if (TREE_CODE (arg1
) == INTEGER_CST
)
2409 return fold_convert_const_fixed_from_int (type
, arg1
);
2410 else if (TREE_CODE (arg1
) == REAL_CST
)
2411 return fold_convert_const_fixed_from_real (type
, arg1
);
2416 /* Construct a vector of zero elements of vector type TYPE. */
2419 build_zero_vector (tree type
)
2424 elem
= fold_convert_const (NOP_EXPR
, TREE_TYPE (type
), integer_zero_node
);
2425 units
= TYPE_VECTOR_SUBPARTS (type
);
2428 for (i
= 0; i
< units
; i
++)
2429 list
= tree_cons (NULL_TREE
, elem
, list
);
2430 return build_vector (type
, list
);
2433 /* Returns true, if ARG is convertible to TYPE using a NOP_EXPR. */
2436 fold_convertible_p (const_tree type
, const_tree arg
)
2438 tree orig
= TREE_TYPE (arg
);
2443 if (TREE_CODE (arg
) == ERROR_MARK
2444 || TREE_CODE (type
) == ERROR_MARK
2445 || TREE_CODE (orig
) == ERROR_MARK
)
2448 if (TYPE_MAIN_VARIANT (type
) == TYPE_MAIN_VARIANT (orig
))
2451 switch (TREE_CODE (type
))
2453 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
2454 case POINTER_TYPE
: case REFERENCE_TYPE
:
2456 if (INTEGRAL_TYPE_P (orig
) || POINTER_TYPE_P (orig
)
2457 || TREE_CODE (orig
) == OFFSET_TYPE
)
2459 return (TREE_CODE (orig
) == VECTOR_TYPE
2460 && tree_int_cst_equal (TYPE_SIZE (type
), TYPE_SIZE (orig
)));
2463 return TREE_CODE (type
) == TREE_CODE (orig
);
2467 /* Convert expression ARG to type TYPE. Used by the middle-end for
2468 simple conversions in preference to calling the front-end's convert. */
2471 fold_convert (tree type
, tree arg
)
2473 tree orig
= TREE_TYPE (arg
);
2479 if (TREE_CODE (arg
) == ERROR_MARK
2480 || TREE_CODE (type
) == ERROR_MARK
2481 || TREE_CODE (orig
) == ERROR_MARK
)
2482 return error_mark_node
;
2484 if (TYPE_MAIN_VARIANT (type
) == TYPE_MAIN_VARIANT (orig
))
2485 return fold_build1 (NOP_EXPR
, type
, arg
);
2487 switch (TREE_CODE (type
))
2489 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
2490 case POINTER_TYPE
: case REFERENCE_TYPE
:
2492 if (TREE_CODE (arg
) == INTEGER_CST
)
2494 tem
= fold_convert_const (NOP_EXPR
, type
, arg
);
2495 if (tem
!= NULL_TREE
)
2498 if (INTEGRAL_TYPE_P (orig
) || POINTER_TYPE_P (orig
)
2499 || TREE_CODE (orig
) == OFFSET_TYPE
)
2500 return fold_build1 (NOP_EXPR
, type
, arg
);
2501 if (TREE_CODE (orig
) == COMPLEX_TYPE
)
2503 tem
= fold_build1 (REALPART_EXPR
, TREE_TYPE (orig
), arg
);
2504 return fold_convert (type
, tem
);
2506 gcc_assert (TREE_CODE (orig
) == VECTOR_TYPE
2507 && tree_int_cst_equal (TYPE_SIZE (type
), TYPE_SIZE (orig
)));
2508 return fold_build1 (NOP_EXPR
, type
, arg
);
2511 if (TREE_CODE (arg
) == INTEGER_CST
)
2513 tem
= fold_convert_const (FLOAT_EXPR
, type
, arg
);
2514 if (tem
!= NULL_TREE
)
2517 else if (TREE_CODE (arg
) == REAL_CST
)
2519 tem
= fold_convert_const (NOP_EXPR
, type
, arg
);
2520 if (tem
!= NULL_TREE
)
2523 else if (TREE_CODE (arg
) == FIXED_CST
)
2525 tem
= fold_convert_const (FIXED_CONVERT_EXPR
, type
, arg
);
2526 if (tem
!= NULL_TREE
)
2530 switch (TREE_CODE (orig
))
2533 case BOOLEAN_TYPE
: case ENUMERAL_TYPE
:
2534 case POINTER_TYPE
: case REFERENCE_TYPE
:
2535 return fold_build1 (FLOAT_EXPR
, type
, arg
);
2538 return fold_build1 (NOP_EXPR
, type
, arg
);
2540 case FIXED_POINT_TYPE
:
2541 return fold_build1 (FIXED_CONVERT_EXPR
, type
, arg
);
2544 tem
= fold_build1 (REALPART_EXPR
, TREE_TYPE (orig
), arg
);
2545 return fold_convert (type
, tem
);
2551 case FIXED_POINT_TYPE
:
2552 if (TREE_CODE (arg
) == FIXED_CST
|| TREE_CODE (arg
) == INTEGER_CST
2553 || TREE_CODE (arg
) == REAL_CST
)
2555 tem
= fold_convert_const (FIXED_CONVERT_EXPR
, type
, arg
);
2556 if (tem
!= NULL_TREE
)
2560 switch (TREE_CODE (orig
))
2562 case FIXED_POINT_TYPE
:
2567 return fold_build1 (FIXED_CONVERT_EXPR
, type
, arg
);
2570 tem
= fold_build1 (REALPART_EXPR
, TREE_TYPE (orig
), arg
);
2571 return fold_convert (type
, tem
);
2578 switch (TREE_CODE (orig
))
2581 case BOOLEAN_TYPE
: case ENUMERAL_TYPE
:
2582 case POINTER_TYPE
: case REFERENCE_TYPE
:
2584 case FIXED_POINT_TYPE
:
2585 return build2 (COMPLEX_EXPR
, type
,
2586 fold_convert (TREE_TYPE (type
), arg
),
2587 fold_convert (TREE_TYPE (type
), integer_zero_node
));
2592 if (TREE_CODE (arg
) == COMPLEX_EXPR
)
2594 rpart
= fold_convert (TREE_TYPE (type
), TREE_OPERAND (arg
, 0));
2595 ipart
= fold_convert (TREE_TYPE (type
), TREE_OPERAND (arg
, 1));
2596 return fold_build2 (COMPLEX_EXPR
, type
, rpart
, ipart
);
2599 arg
= save_expr (arg
);
2600 rpart
= fold_build1 (REALPART_EXPR
, TREE_TYPE (orig
), arg
);
2601 ipart
= fold_build1 (IMAGPART_EXPR
, TREE_TYPE (orig
), arg
);
2602 rpart
= fold_convert (TREE_TYPE (type
), rpart
);
2603 ipart
= fold_convert (TREE_TYPE (type
), ipart
);
2604 return fold_build2 (COMPLEX_EXPR
, type
, rpart
, ipart
);
2612 if (integer_zerop (arg
))
2613 return build_zero_vector (type
);
2614 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type
), TYPE_SIZE (orig
)));
2615 gcc_assert (INTEGRAL_TYPE_P (orig
) || POINTER_TYPE_P (orig
)
2616 || TREE_CODE (orig
) == VECTOR_TYPE
);
2617 return fold_build1 (VIEW_CONVERT_EXPR
, type
, arg
);
2620 tem
= fold_ignored_result (arg
);
2621 if (TREE_CODE (tem
) == GIMPLE_MODIFY_STMT
)
2623 return fold_build1 (NOP_EXPR
, type
, tem
);
2630 /* Return false if expr can be assumed not to be an lvalue, true
2634 maybe_lvalue_p (tree x
)
2636 /* We only need to wrap lvalue tree codes. */
2637 switch (TREE_CODE (x
))
2648 case ALIGN_INDIRECT_REF
:
2649 case MISALIGNED_INDIRECT_REF
:
2651 case ARRAY_RANGE_REF
:
2657 case PREINCREMENT_EXPR
:
2658 case PREDECREMENT_EXPR
:
2660 case TRY_CATCH_EXPR
:
2661 case WITH_CLEANUP_EXPR
:
2664 case GIMPLE_MODIFY_STMT
:
2673 /* Assume the worst for front-end tree codes. */
2674 if ((int)TREE_CODE (x
) >= NUM_TREE_CODES
)
2682 /* Return an expr equal to X but certainly not valid as an lvalue. */
2687 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2692 if (! maybe_lvalue_p (x
))
2694 return build1 (NON_LVALUE_EXPR
, TREE_TYPE (x
), x
);
2697 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2698 Zero means allow extended lvalues. */
2700 int pedantic_lvalues
;
2702 /* When pedantic, return an expr equal to X but certainly not valid as a
2703 pedantic lvalue. Otherwise, return X. */
2706 pedantic_non_lvalue (tree x
)
2708 if (pedantic_lvalues
)
2709 return non_lvalue (x
);
2714 /* Given a tree comparison code, return the code that is the logical inverse
2715 of the given code. It is not safe to do this for floating-point
2716 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2717 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2720 invert_tree_comparison (enum tree_code code
, bool honor_nans
)
2722 if (honor_nans
&& flag_trapping_math
)
2732 return honor_nans
? UNLE_EXPR
: LE_EXPR
;
2734 return honor_nans
? UNLT_EXPR
: LT_EXPR
;
2736 return honor_nans
? UNGE_EXPR
: GE_EXPR
;
2738 return honor_nans
? UNGT_EXPR
: GT_EXPR
;
2752 return UNORDERED_EXPR
;
2753 case UNORDERED_EXPR
:
2754 return ORDERED_EXPR
;
2760 /* Similar, but return the comparison that results if the operands are
2761 swapped. This is safe for floating-point. */
2764 swap_tree_comparison (enum tree_code code
)
2771 case UNORDERED_EXPR
:
2797 /* Convert a comparison tree code from an enum tree_code representation
2798 into a compcode bit-based encoding. This function is the inverse of
2799 compcode_to_comparison. */
2801 static enum comparison_code
2802 comparison_to_compcode (enum tree_code code
)
2819 return COMPCODE_ORD
;
2820 case UNORDERED_EXPR
:
2821 return COMPCODE_UNORD
;
2823 return COMPCODE_UNLT
;
2825 return COMPCODE_UNEQ
;
2827 return COMPCODE_UNLE
;
2829 return COMPCODE_UNGT
;
2831 return COMPCODE_LTGT
;
2833 return COMPCODE_UNGE
;
2839 /* Convert a compcode bit-based encoding of a comparison operator back
2840 to GCC's enum tree_code representation. This function is the
2841 inverse of comparison_to_compcode. */
2843 static enum tree_code
2844 compcode_to_comparison (enum comparison_code code
)
2861 return ORDERED_EXPR
;
2862 case COMPCODE_UNORD
:
2863 return UNORDERED_EXPR
;
2881 /* Return a tree for the comparison which is the combination of
2882 doing the AND or OR (depending on CODE) of the two operations LCODE
2883 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2884 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2885 if this makes the transformation invalid. */
2888 combine_comparisons (enum tree_code code
, enum tree_code lcode
,
2889 enum tree_code rcode
, tree truth_type
,
2890 tree ll_arg
, tree lr_arg
)
2892 bool honor_nans
= HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg
)));
2893 enum comparison_code lcompcode
= comparison_to_compcode (lcode
);
2894 enum comparison_code rcompcode
= comparison_to_compcode (rcode
);
2895 enum comparison_code compcode
;
2899 case TRUTH_AND_EXPR
: case TRUTH_ANDIF_EXPR
:
2900 compcode
= lcompcode
& rcompcode
;
2903 case TRUTH_OR_EXPR
: case TRUTH_ORIF_EXPR
:
2904 compcode
= lcompcode
| rcompcode
;
2913 /* Eliminate unordered comparisons, as well as LTGT and ORD
2914 which are not used unless the mode has NaNs. */
2915 compcode
&= ~COMPCODE_UNORD
;
2916 if (compcode
== COMPCODE_LTGT
)
2917 compcode
= COMPCODE_NE
;
2918 else if (compcode
== COMPCODE_ORD
)
2919 compcode
= COMPCODE_TRUE
;
2921 else if (flag_trapping_math
)
2923 /* Check that the original operation and the optimized ones will trap
2924 under the same condition. */
2925 bool ltrap
= (lcompcode
& COMPCODE_UNORD
) == 0
2926 && (lcompcode
!= COMPCODE_EQ
)
2927 && (lcompcode
!= COMPCODE_ORD
);
2928 bool rtrap
= (rcompcode
& COMPCODE_UNORD
) == 0
2929 && (rcompcode
!= COMPCODE_EQ
)
2930 && (rcompcode
!= COMPCODE_ORD
);
2931 bool trap
= (compcode
& COMPCODE_UNORD
) == 0
2932 && (compcode
!= COMPCODE_EQ
)
2933 && (compcode
!= COMPCODE_ORD
);
2935 /* In a short-circuited boolean expression the LHS might be
2936 such that the RHS, if evaluated, will never trap. For
2937 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2938 if neither x nor y is NaN. (This is a mixed blessing: for
2939 example, the expression above will never trap, hence
2940 optimizing it to x < y would be invalid). */
2941 if ((code
== TRUTH_ORIF_EXPR
&& (lcompcode
& COMPCODE_UNORD
))
2942 || (code
== TRUTH_ANDIF_EXPR
&& !(lcompcode
& COMPCODE_UNORD
)))
2945 /* If the comparison was short-circuited, and only the RHS
2946 trapped, we may now generate a spurious trap. */
2948 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
))
2951 /* If we changed the conditions that cause a trap, we lose. */
2952 if ((ltrap
|| rtrap
) != trap
)
2956 if (compcode
== COMPCODE_TRUE
)
2957 return constant_boolean_node (true, truth_type
);
2958 else if (compcode
== COMPCODE_FALSE
)
2959 return constant_boolean_node (false, truth_type
);
2961 return fold_build2 (compcode_to_comparison (compcode
),
2962 truth_type
, ll_arg
, lr_arg
);
2965 /* Return nonzero if CODE is a tree code that represents a truth value. */
2968 truth_value_p (enum tree_code code
)
2970 return (TREE_CODE_CLASS (code
) == tcc_comparison
2971 || code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
2972 || code
== TRUTH_OR_EXPR
|| code
== TRUTH_ORIF_EXPR
2973 || code
== TRUTH_XOR_EXPR
|| code
== TRUTH_NOT_EXPR
);
2976 /* Return nonzero if two operands (typically of the same tree node)
2977 are necessarily equal. If either argument has side-effects this
2978 function returns zero. FLAGS modifies behavior as follows:
2980 If OEP_ONLY_CONST is set, only return nonzero for constants.
2981 This function tests whether the operands are indistinguishable;
2982 it does not test whether they are equal using C's == operation.
2983 The distinction is important for IEEE floating point, because
2984 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2985 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2987 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2988 even though it may hold multiple values during a function.
2989 This is because a GCC tree node guarantees that nothing else is
2990 executed between the evaluation of its "operands" (which may often
2991 be evaluated in arbitrary order). Hence if the operands themselves
2992 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2993 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2994 unset means assuming isochronic (or instantaneous) tree equivalence.
2995 Unless comparing arbitrary expression trees, such as from different
2996 statements, this flag can usually be left unset.
2998 If OEP_PURE_SAME is set, then pure functions with identical arguments
2999 are considered the same. It is used when the caller has other ways
3000 to ensure that global memory is unchanged in between. */
3003 operand_equal_p (const_tree arg0
, const_tree arg1
, unsigned int flags
)
3005 /* If either is ERROR_MARK, they aren't equal. */
3006 if (TREE_CODE (arg0
) == ERROR_MARK
|| TREE_CODE (arg1
) == ERROR_MARK
)
3009 /* If both types don't have the same signedness, then we can't consider
3010 them equal. We must check this before the STRIP_NOPS calls
3011 because they may change the signedness of the arguments. */
3012 if (TYPE_UNSIGNED (TREE_TYPE (arg0
)) != TYPE_UNSIGNED (TREE_TYPE (arg1
)))
3015 /* If both types don't have the same precision, then it is not safe
3017 if (TYPE_PRECISION (TREE_TYPE (arg0
)) != TYPE_PRECISION (TREE_TYPE (arg1
)))
3023 /* In case both args are comparisons but with different comparison
3024 code, try to swap the comparison operands of one arg to produce
3025 a match and compare that variant. */
3026 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
3027 && COMPARISON_CLASS_P (arg0
)
3028 && COMPARISON_CLASS_P (arg1
))
3030 enum tree_code swap_code
= swap_tree_comparison (TREE_CODE (arg1
));
3032 if (TREE_CODE (arg0
) == swap_code
)
3033 return operand_equal_p (TREE_OPERAND (arg0
, 0),
3034 TREE_OPERAND (arg1
, 1), flags
)
3035 && operand_equal_p (TREE_OPERAND (arg0
, 1),
3036 TREE_OPERAND (arg1
, 0), flags
);
3039 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
3040 /* This is needed for conversions and for COMPONENT_REF.
3041 Might as well play it safe and always test this. */
3042 || TREE_CODE (TREE_TYPE (arg0
)) == ERROR_MARK
3043 || TREE_CODE (TREE_TYPE (arg1
)) == ERROR_MARK
3044 || TYPE_MODE (TREE_TYPE (arg0
)) != TYPE_MODE (TREE_TYPE (arg1
)))
3047 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
3048 We don't care about side effects in that case because the SAVE_EXPR
3049 takes care of that for us. In all other cases, two expressions are
3050 equal if they have no side effects. If we have two identical
3051 expressions with side effects that should be treated the same due
3052 to the only side effects being identical SAVE_EXPR's, that will
3053 be detected in the recursive calls below. */
3054 if (arg0
== arg1
&& ! (flags
& OEP_ONLY_CONST
)
3055 && (TREE_CODE (arg0
) == SAVE_EXPR
3056 || (! TREE_SIDE_EFFECTS (arg0
) && ! TREE_SIDE_EFFECTS (arg1
))))
3059 /* Next handle constant cases, those for which we can return 1 even
3060 if ONLY_CONST is set. */
3061 if (TREE_CONSTANT (arg0
) && TREE_CONSTANT (arg1
))
3062 switch (TREE_CODE (arg0
))
3065 return tree_int_cst_equal (arg0
, arg1
);
3068 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (arg0
),
3069 TREE_FIXED_CST (arg1
));
3072 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0
),
3073 TREE_REAL_CST (arg1
)))
3077 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0
))))
3079 /* If we do not distinguish between signed and unsigned zero,
3080 consider them equal. */
3081 if (real_zerop (arg0
) && real_zerop (arg1
))
3090 v1
= TREE_VECTOR_CST_ELTS (arg0
);
3091 v2
= TREE_VECTOR_CST_ELTS (arg1
);
3094 if (!operand_equal_p (TREE_VALUE (v1
), TREE_VALUE (v2
),
3097 v1
= TREE_CHAIN (v1
);
3098 v2
= TREE_CHAIN (v2
);
3105 return (operand_equal_p (TREE_REALPART (arg0
), TREE_REALPART (arg1
),
3107 && operand_equal_p (TREE_IMAGPART (arg0
), TREE_IMAGPART (arg1
),
3111 return (TREE_STRING_LENGTH (arg0
) == TREE_STRING_LENGTH (arg1
)
3112 && ! memcmp (TREE_STRING_POINTER (arg0
),
3113 TREE_STRING_POINTER (arg1
),
3114 TREE_STRING_LENGTH (arg0
)));
3117 return operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0),
3123 if (flags
& OEP_ONLY_CONST
)
3126 /* Define macros to test an operand from arg0 and arg1 for equality and a
3127 variant that allows null and views null as being different from any
3128 non-null value. In the latter case, if either is null, the both
3129 must be; otherwise, do the normal comparison. */
3130 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
3131 TREE_OPERAND (arg1, N), flags)
3133 #define OP_SAME_WITH_NULL(N) \
3134 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
3135 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
3137 switch (TREE_CODE_CLASS (TREE_CODE (arg0
)))
3140 /* Two conversions are equal only if signedness and modes match. */
3141 switch (TREE_CODE (arg0
))
3145 case FIX_TRUNC_EXPR
:
3146 if (TYPE_UNSIGNED (TREE_TYPE (arg0
))
3147 != TYPE_UNSIGNED (TREE_TYPE (arg1
)))
3157 case tcc_comparison
:
3159 if (OP_SAME (0) && OP_SAME (1))
3162 /* For commutative ops, allow the other order. */
3163 return (commutative_tree_code (TREE_CODE (arg0
))
3164 && operand_equal_p (TREE_OPERAND (arg0
, 0),
3165 TREE_OPERAND (arg1
, 1), flags
)
3166 && operand_equal_p (TREE_OPERAND (arg0
, 1),
3167 TREE_OPERAND (arg1
, 0), flags
));
3170 /* If either of the pointer (or reference) expressions we are
3171 dereferencing contain a side effect, these cannot be equal. */
3172 if (TREE_SIDE_EFFECTS (arg0
)
3173 || TREE_SIDE_EFFECTS (arg1
))
3176 switch (TREE_CODE (arg0
))
3179 case ALIGN_INDIRECT_REF
:
3180 case MISALIGNED_INDIRECT_REF
:
3186 case ARRAY_RANGE_REF
:
3187 /* Operands 2 and 3 may be null.
3188 Compare the array index by value if it is constant first as we
3189 may have different types but same value here. */
3191 && (tree_int_cst_equal (TREE_OPERAND (arg0
, 1),
3192 TREE_OPERAND (arg1
, 1))
3194 && OP_SAME_WITH_NULL (2)
3195 && OP_SAME_WITH_NULL (3));
3198 /* Handle operand 2 the same as for ARRAY_REF. Operand 0
3199 may be NULL when we're called to compare MEM_EXPRs. */
3200 return OP_SAME_WITH_NULL (0)
3202 && OP_SAME_WITH_NULL (2);
3205 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
3211 case tcc_expression
:
3212 switch (TREE_CODE (arg0
))
3215 case TRUTH_NOT_EXPR
:
3218 case TRUTH_ANDIF_EXPR
:
3219 case TRUTH_ORIF_EXPR
:
3220 return OP_SAME (0) && OP_SAME (1);
3222 case TRUTH_AND_EXPR
:
3224 case TRUTH_XOR_EXPR
:
3225 if (OP_SAME (0) && OP_SAME (1))
3228 /* Otherwise take into account this is a commutative operation. */
3229 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
3230 TREE_OPERAND (arg1
, 1), flags
)
3231 && operand_equal_p (TREE_OPERAND (arg0
, 1),
3232 TREE_OPERAND (arg1
, 0), flags
));
3239 switch (TREE_CODE (arg0
))
3242 /* If the CALL_EXPRs call different functions, then they
3243 clearly can not be equal. */
3244 if (! operand_equal_p (CALL_EXPR_FN (arg0
), CALL_EXPR_FN (arg1
),
3249 unsigned int cef
= call_expr_flags (arg0
);
3250 if (flags
& OEP_PURE_SAME
)
3251 cef
&= ECF_CONST
| ECF_PURE
;
3258 /* Now see if all the arguments are the same. */
3260 const_call_expr_arg_iterator iter0
, iter1
;
3262 for (a0
= first_const_call_expr_arg (arg0
, &iter0
),
3263 a1
= first_const_call_expr_arg (arg1
, &iter1
);
3265 a0
= next_const_call_expr_arg (&iter0
),
3266 a1
= next_const_call_expr_arg (&iter1
))
3267 if (! operand_equal_p (a0
, a1
, flags
))
3270 /* If we get here and both argument lists are exhausted
3271 then the CALL_EXPRs are equal. */
3272 return ! (a0
|| a1
);
3278 case tcc_declaration
:
3279 /* Consider __builtin_sqrt equal to sqrt. */
3280 return (TREE_CODE (arg0
) == FUNCTION_DECL
3281 && DECL_BUILT_IN (arg0
) && DECL_BUILT_IN (arg1
)
3282 && DECL_BUILT_IN_CLASS (arg0
) == DECL_BUILT_IN_CLASS (arg1
)
3283 && DECL_FUNCTION_CODE (arg0
) == DECL_FUNCTION_CODE (arg1
));
3290 #undef OP_SAME_WITH_NULL
3293 /* Similar to operand_equal_p, but see if ARG0 might have been made by
3294 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
3296 When in doubt, return 0. */
3299 operand_equal_for_comparison_p (tree arg0
, tree arg1
, tree other
)
3301 int unsignedp1
, unsignedpo
;
3302 tree primarg0
, primarg1
, primother
;
3303 unsigned int correct_width
;
3305 if (operand_equal_p (arg0
, arg1
, 0))
3308 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
3309 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
3312 /* Discard any conversions that don't change the modes of ARG0 and ARG1
3313 and see if the inner values are the same. This removes any
3314 signedness comparison, which doesn't matter here. */
3315 primarg0
= arg0
, primarg1
= arg1
;
3316 STRIP_NOPS (primarg0
);
3317 STRIP_NOPS (primarg1
);
3318 if (operand_equal_p (primarg0
, primarg1
, 0))
3321 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
3322 actual comparison operand, ARG0.
3324 First throw away any conversions to wider types
3325 already present in the operands. */
3327 primarg1
= get_narrower (arg1
, &unsignedp1
);
3328 primother
= get_narrower (other
, &unsignedpo
);
3330 correct_width
= TYPE_PRECISION (TREE_TYPE (arg1
));
3331 if (unsignedp1
== unsignedpo
3332 && TYPE_PRECISION (TREE_TYPE (primarg1
)) < correct_width
3333 && TYPE_PRECISION (TREE_TYPE (primother
)) < correct_width
)
3335 tree type
= TREE_TYPE (arg0
);
3337 /* Make sure shorter operand is extended the right way
3338 to match the longer operand. */
3339 primarg1
= fold_convert (signed_or_unsigned_type_for
3340 (unsignedp1
, TREE_TYPE (primarg1
)), primarg1
);
3342 if (operand_equal_p (arg0
, fold_convert (type
, primarg1
), 0))
3349 /* See if ARG is an expression that is either a comparison or is performing
3350 arithmetic on comparisons. The comparisons must only be comparing
3351 two different values, which will be stored in *CVAL1 and *CVAL2; if
3352 they are nonzero it means that some operands have already been found.
3353 No variables may be used anywhere else in the expression except in the
3354 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
3355 the expression and save_expr needs to be called with CVAL1 and CVAL2.
3357 If this is true, return 1. Otherwise, return zero. */
3360 twoval_comparison_p (tree arg
, tree
*cval1
, tree
*cval2
, int *save_p
)
3362 enum tree_code code
= TREE_CODE (arg
);
3363 enum tree_code_class
class = TREE_CODE_CLASS (code
);
3365 /* We can handle some of the tcc_expression cases here. */
3366 if (class == tcc_expression
&& code
== TRUTH_NOT_EXPR
)
3368 else if (class == tcc_expression
3369 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
3370 || code
== COMPOUND_EXPR
))
3373 else if (class == tcc_expression
&& code
== SAVE_EXPR
3374 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg
, 0)))
3376 /* If we've already found a CVAL1 or CVAL2, this expression is
3377 two complex to handle. */
3378 if (*cval1
|| *cval2
)
3388 return twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
);
3391 return (twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
)
3392 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
3393 cval1
, cval2
, save_p
));
3398 case tcc_expression
:
3399 if (code
== COND_EXPR
)
3400 return (twoval_comparison_p (TREE_OPERAND (arg
, 0),
3401 cval1
, cval2
, save_p
)
3402 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
3403 cval1
, cval2
, save_p
)
3404 && twoval_comparison_p (TREE_OPERAND (arg
, 2),
3405 cval1
, cval2
, save_p
));
3408 case tcc_comparison
:
3409 /* First see if we can handle the first operand, then the second. For
3410 the second operand, we know *CVAL1 can't be zero. It must be that
3411 one side of the comparison is each of the values; test for the
3412 case where this isn't true by failing if the two operands
3415 if (operand_equal_p (TREE_OPERAND (arg
, 0),
3416 TREE_OPERAND (arg
, 1), 0))
3420 *cval1
= TREE_OPERAND (arg
, 0);
3421 else if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 0), 0))
3423 else if (*cval2
== 0)
3424 *cval2
= TREE_OPERAND (arg
, 0);
3425 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 0), 0))
3430 if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 1), 0))
3432 else if (*cval2
== 0)
3433 *cval2
= TREE_OPERAND (arg
, 1);
3434 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 1), 0))
3446 /* ARG is a tree that is known to contain just arithmetic operations and
3447 comparisons. Evaluate the operations in the tree substituting NEW0 for
3448 any occurrence of OLD0 as an operand of a comparison and likewise for
3452 eval_subst (tree arg
, tree old0
, tree new0
, tree old1
, tree new1
)
3454 tree type
= TREE_TYPE (arg
);
3455 enum tree_code code
= TREE_CODE (arg
);
3456 enum tree_code_class
class = TREE_CODE_CLASS (code
);
3458 /* We can handle some of the tcc_expression cases here. */
3459 if (class == tcc_expression
&& code
== TRUTH_NOT_EXPR
)
3461 else if (class == tcc_expression
3462 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
))
3468 return fold_build1 (code
, type
,
3469 eval_subst (TREE_OPERAND (arg
, 0),
3470 old0
, new0
, old1
, new1
));
3473 return fold_build2 (code
, type
,
3474 eval_subst (TREE_OPERAND (arg
, 0),
3475 old0
, new0
, old1
, new1
),
3476 eval_subst (TREE_OPERAND (arg
, 1),
3477 old0
, new0
, old1
, new1
));
3479 case tcc_expression
:
3483 return eval_subst (TREE_OPERAND (arg
, 0), old0
, new0
, old1
, new1
);
3486 return eval_subst (TREE_OPERAND (arg
, 1), old0
, new0
, old1
, new1
);
3489 return fold_build3 (code
, type
,
3490 eval_subst (TREE_OPERAND (arg
, 0),
3491 old0
, new0
, old1
, new1
),
3492 eval_subst (TREE_OPERAND (arg
, 1),
3493 old0
, new0
, old1
, new1
),
3494 eval_subst (TREE_OPERAND (arg
, 2),
3495 old0
, new0
, old1
, new1
));
3499 /* Fall through - ??? */
3501 case tcc_comparison
:
3503 tree arg0
= TREE_OPERAND (arg
, 0);
3504 tree arg1
= TREE_OPERAND (arg
, 1);
3506 /* We need to check both for exact equality and tree equality. The
3507 former will be true if the operand has a side-effect. In that
3508 case, we know the operand occurred exactly once. */
3510 if (arg0
== old0
|| operand_equal_p (arg0
, old0
, 0))
3512 else if (arg0
== old1
|| operand_equal_p (arg0
, old1
, 0))
3515 if (arg1
== old0
|| operand_equal_p (arg1
, old0
, 0))
3517 else if (arg1
== old1
|| operand_equal_p (arg1
, old1
, 0))
3520 return fold_build2 (code
, type
, arg0
, arg1
);
3528 /* Return a tree for the case when the result of an expression is RESULT
3529 converted to TYPE and OMITTED was previously an operand of the expression
3530 but is now not needed (e.g., we folded OMITTED * 0).
3532 If OMITTED has side effects, we must evaluate it. Otherwise, just do
3533 the conversion of RESULT to TYPE. */
3536 omit_one_operand (tree type
, tree result
, tree omitted
)
3538 tree t
= fold_convert (type
, result
);
3540 /* If the resulting operand is an empty statement, just return the ommited
3541 statement casted to void. */
3542 if (IS_EMPTY_STMT (t
) && TREE_SIDE_EFFECTS (omitted
))
3543 return build1 (NOP_EXPR
, void_type_node
, fold_ignored_result (omitted
));
3545 if (TREE_SIDE_EFFECTS (omitted
))
3546 return build2 (COMPOUND_EXPR
, type
, fold_ignored_result (omitted
), t
);
3548 return non_lvalue (t
);
3551 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
3554 pedantic_omit_one_operand (tree type
, tree result
, tree omitted
)
3556 tree t
= fold_convert (type
, result
);
3558 /* If the resulting operand is an empty statement, just return the ommited
3559 statement casted to void. */
3560 if (IS_EMPTY_STMT (t
) && TREE_SIDE_EFFECTS (omitted
))
3561 return build1 (NOP_EXPR
, void_type_node
, fold_ignored_result (omitted
));
3563 if (TREE_SIDE_EFFECTS (omitted
))
3564 return build2 (COMPOUND_EXPR
, type
, fold_ignored_result (omitted
), t
);
3566 return pedantic_non_lvalue (t
);
3569 /* Return a tree for the case when the result of an expression is RESULT
3570 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
3571 of the expression but are now not needed.
3573 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
3574 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
3575 evaluated before OMITTED2. Otherwise, if neither has side effects,
3576 just do the conversion of RESULT to TYPE. */
3579 omit_two_operands (tree type
, tree result
, tree omitted1
, tree omitted2
)
3581 tree t
= fold_convert (type
, result
);
3583 if (TREE_SIDE_EFFECTS (omitted2
))
3584 t
= build2 (COMPOUND_EXPR
, type
, omitted2
, t
);
3585 if (TREE_SIDE_EFFECTS (omitted1
))
3586 t
= build2 (COMPOUND_EXPR
, type
, omitted1
, t
);
3588 return TREE_CODE (t
) != COMPOUND_EXPR
? non_lvalue (t
) : t
;
3592 /* Return a simplified tree node for the truth-negation of ARG. This
3593 never alters ARG itself. We assume that ARG is an operation that
3594 returns a truth value (0 or 1).
3596 FIXME: one would think we would fold the result, but it causes
3597 problems with the dominator optimizer. */
3600 fold_truth_not_expr (tree arg
)
3602 tree type
= TREE_TYPE (arg
);
3603 enum tree_code code
= TREE_CODE (arg
);
3605 /* If this is a comparison, we can simply invert it, except for
3606 floating-point non-equality comparisons, in which case we just
3607 enclose a TRUTH_NOT_EXPR around what we have. */
3609 if (TREE_CODE_CLASS (code
) == tcc_comparison
)
3611 tree op_type
= TREE_TYPE (TREE_OPERAND (arg
, 0));
3612 if (FLOAT_TYPE_P (op_type
)
3613 && flag_trapping_math
3614 && code
!= ORDERED_EXPR
&& code
!= UNORDERED_EXPR
3615 && code
!= NE_EXPR
&& code
!= EQ_EXPR
)
3619 code
= invert_tree_comparison (code
,
3620 HONOR_NANS (TYPE_MODE (op_type
)));
3621 if (code
== ERROR_MARK
)
3624 return build2 (code
, type
,
3625 TREE_OPERAND (arg
, 0), TREE_OPERAND (arg
, 1));
3632 return constant_boolean_node (integer_zerop (arg
), type
);
3634 case TRUTH_AND_EXPR
:
3635 return build2 (TRUTH_OR_EXPR
, type
,
3636 invert_truthvalue (TREE_OPERAND (arg
, 0)),
3637 invert_truthvalue (TREE_OPERAND (arg
, 1)));
3640 return build2 (TRUTH_AND_EXPR
, type
,
3641 invert_truthvalue (TREE_OPERAND (arg
, 0)),
3642 invert_truthvalue (TREE_OPERAND (arg
, 1)));
3644 case TRUTH_XOR_EXPR
:
3645 /* Here we can invert either operand. We invert the first operand
3646 unless the second operand is a TRUTH_NOT_EXPR in which case our
3647 result is the XOR of the first operand with the inside of the
3648 negation of the second operand. */
3650 if (TREE_CODE (TREE_OPERAND (arg
, 1)) == TRUTH_NOT_EXPR
)
3651 return build2 (TRUTH_XOR_EXPR
, type
, TREE_OPERAND (arg
, 0),
3652 TREE_OPERAND (TREE_OPERAND (arg
, 1), 0));
3654 return build2 (TRUTH_XOR_EXPR
, type
,
3655 invert_truthvalue (TREE_OPERAND (arg
, 0)),
3656 TREE_OPERAND (arg
, 1));
3658 case TRUTH_ANDIF_EXPR
:
3659 return build2 (TRUTH_ORIF_EXPR
, type
,
3660 invert_truthvalue (TREE_OPERAND (arg
, 0)),
3661 invert_truthvalue (TREE_OPERAND (arg
, 1)));
3663 case TRUTH_ORIF_EXPR
:
3664 return build2 (TRUTH_ANDIF_EXPR
, type
,
3665 invert_truthvalue (TREE_OPERAND (arg
, 0)),
3666 invert_truthvalue (TREE_OPERAND (arg
, 1)));
3668 case TRUTH_NOT_EXPR
:
3669 return TREE_OPERAND (arg
, 0);
3673 tree arg1
= TREE_OPERAND (arg
, 1);
3674 tree arg2
= TREE_OPERAND (arg
, 2);
3675 /* A COND_EXPR may have a throw as one operand, which
3676 then has void type. Just leave void operands
3678 return build3 (COND_EXPR
, type
, TREE_OPERAND (arg
, 0),
3679 VOID_TYPE_P (TREE_TYPE (arg1
))
3680 ? arg1
: invert_truthvalue (arg1
),
3681 VOID_TYPE_P (TREE_TYPE (arg2
))
3682 ? arg2
: invert_truthvalue (arg2
));
3686 return build2 (COMPOUND_EXPR
, type
, TREE_OPERAND (arg
, 0),
3687 invert_truthvalue (TREE_OPERAND (arg
, 1)));
3689 case NON_LVALUE_EXPR
:
3690 return invert_truthvalue (TREE_OPERAND (arg
, 0));
3693 if (TREE_CODE (TREE_TYPE (arg
)) == BOOLEAN_TYPE
)
3694 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
3698 return build1 (TREE_CODE (arg
), type
,
3699 invert_truthvalue (TREE_OPERAND (arg
, 0)));
3702 if (!integer_onep (TREE_OPERAND (arg
, 1)))
3704 return build2 (EQ_EXPR
, type
, arg
,
3705 build_int_cst (type
, 0));
3708 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
3710 case CLEANUP_POINT_EXPR
:
3711 return build1 (CLEANUP_POINT_EXPR
, type
,
3712 invert_truthvalue (TREE_OPERAND (arg
, 0)));
3721 /* Return a simplified tree node for the truth-negation of ARG. This
3722 never alters ARG itself. We assume that ARG is an operation that
3723 returns a truth value (0 or 1).
3725 FIXME: one would think we would fold the result, but it causes
3726 problems with the dominator optimizer. */
3729 invert_truthvalue (tree arg
)
3733 if (TREE_CODE (arg
) == ERROR_MARK
)
3736 tem
= fold_truth_not_expr (arg
);
3738 tem
= build1 (TRUTH_NOT_EXPR
, TREE_TYPE (arg
), arg
);
3743 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3744 operands are another bit-wise operation with a common input. If so,
3745 distribute the bit operations to save an operation and possibly two if
3746 constants are involved. For example, convert
3747 (A | B) & (A | C) into A | (B & C)
3748 Further simplification will occur if B and C are constants.
3750 If this optimization cannot be done, 0 will be returned. */
3753 distribute_bit_expr (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
3758 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
3759 || TREE_CODE (arg0
) == code
3760 || (TREE_CODE (arg0
) != BIT_AND_EXPR
3761 && TREE_CODE (arg0
) != BIT_IOR_EXPR
))
3764 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0))
3766 common
= TREE_OPERAND (arg0
, 0);
3767 left
= TREE_OPERAND (arg0
, 1);
3768 right
= TREE_OPERAND (arg1
, 1);
3770 else if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 1), 0))
3772 common
= TREE_OPERAND (arg0
, 0);
3773 left
= TREE_OPERAND (arg0
, 1);
3774 right
= TREE_OPERAND (arg1
, 0);
3776 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 0), 0))
3778 common
= TREE_OPERAND (arg0
, 1);
3779 left
= TREE_OPERAND (arg0
, 0);
3780 right
= TREE_OPERAND (arg1
, 1);
3782 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1), 0))
3784 common
= TREE_OPERAND (arg0
, 1);
3785 left
= TREE_OPERAND (arg0
, 0);
3786 right
= TREE_OPERAND (arg1
, 0);
3791 return fold_build2 (TREE_CODE (arg0
), type
, common
,
3792 fold_build2 (code
, type
, left
, right
));
3795 /* Knowing that ARG0 and ARG1 are both RDIV_EXPRs, simplify a binary operation
3796 with code CODE. This optimization is unsafe. */
3798 distribute_real_division (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
3800 bool mul0
= TREE_CODE (arg0
) == MULT_EXPR
;
3801 bool mul1
= TREE_CODE (arg1
) == MULT_EXPR
;
3803 /* (A / C) +- (B / C) -> (A +- B) / C. */
3805 && operand_equal_p (TREE_OPERAND (arg0
, 1),
3806 TREE_OPERAND (arg1
, 1), 0))
3807 return fold_build2 (mul0
? MULT_EXPR
: RDIV_EXPR
, type
,
3808 fold_build2 (code
, type
,
3809 TREE_OPERAND (arg0
, 0),
3810 TREE_OPERAND (arg1
, 0)),
3811 TREE_OPERAND (arg0
, 1));
3813 /* (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2). */
3814 if (operand_equal_p (TREE_OPERAND (arg0
, 0),
3815 TREE_OPERAND (arg1
, 0), 0)
3816 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == REAL_CST
3817 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == REAL_CST
)
3819 REAL_VALUE_TYPE r0
, r1
;
3820 r0
= TREE_REAL_CST (TREE_OPERAND (arg0
, 1));
3821 r1
= TREE_REAL_CST (TREE_OPERAND (arg1
, 1));
3823 real_arithmetic (&r0
, RDIV_EXPR
, &dconst1
, &r0
);
3825 real_arithmetic (&r1
, RDIV_EXPR
, &dconst1
, &r1
);
3826 real_arithmetic (&r0
, code
, &r0
, &r1
);
3827 return fold_build2 (MULT_EXPR
, type
,
3828 TREE_OPERAND (arg0
, 0),
3829 build_real (type
, r0
));
3835 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3836 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3839 make_bit_field_ref (tree inner
, tree type
, int bitsize
, int bitpos
,
3846 tree size
= TYPE_SIZE (TREE_TYPE (inner
));
3847 if ((INTEGRAL_TYPE_P (TREE_TYPE (inner
))
3848 || POINTER_TYPE_P (TREE_TYPE (inner
)))
3849 && host_integerp (size
, 0)
3850 && tree_low_cst (size
, 0) == bitsize
)
3851 return fold_convert (type
, inner
);
3854 result
= build3 (BIT_FIELD_REF
, type
, inner
,
3855 size_int (bitsize
), bitsize_int (bitpos
));
3857 BIT_FIELD_REF_UNSIGNED (result
) = unsignedp
;
3862 /* Optimize a bit-field compare.
3864 There are two cases: First is a compare against a constant and the
3865 second is a comparison of two items where the fields are at the same
3866 bit position relative to the start of a chunk (byte, halfword, word)
3867 large enough to contain it. In these cases we can avoid the shift
3868 implicit in bitfield extractions.
3870 For constants, we emit a compare of the shifted constant with the
3871 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3872 compared. For two fields at the same position, we do the ANDs with the
3873 similar mask and compare the result of the ANDs.
3875 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3876 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3877 are the left and right operands of the comparison, respectively.
3879 If the optimization described above can be done, we return the resulting
3880 tree. Otherwise we return zero. */
3883 optimize_bit_field_compare (enum tree_code code
, tree compare_type
,
3886 HOST_WIDE_INT lbitpos
, lbitsize
, rbitpos
, rbitsize
, nbitpos
, nbitsize
;
3887 tree type
= TREE_TYPE (lhs
);
3888 tree signed_type
, unsigned_type
;
3889 int const_p
= TREE_CODE (rhs
) == INTEGER_CST
;
3890 enum machine_mode lmode
, rmode
, nmode
;
3891 int lunsignedp
, runsignedp
;
3892 int lvolatilep
= 0, rvolatilep
= 0;
3893 tree linner
, rinner
= NULL_TREE
;
3897 /* Get all the information about the extractions being done. If the bit size
3898 if the same as the size of the underlying object, we aren't doing an
3899 extraction at all and so can do nothing. We also don't want to
3900 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3901 then will no longer be able to replace it. */
3902 linner
= get_inner_reference (lhs
, &lbitsize
, &lbitpos
, &offset
, &lmode
,
3903 &lunsignedp
, &lvolatilep
, false);
3904 if (linner
== lhs
|| lbitsize
== GET_MODE_BITSIZE (lmode
) || lbitsize
< 0
3905 || offset
!= 0 || TREE_CODE (linner
) == PLACEHOLDER_EXPR
)
3910 /* If this is not a constant, we can only do something if bit positions,
3911 sizes, and signedness are the same. */
3912 rinner
= get_inner_reference (rhs
, &rbitsize
, &rbitpos
, &offset
, &rmode
,
3913 &runsignedp
, &rvolatilep
, false);
3915 if (rinner
== rhs
|| lbitpos
!= rbitpos
|| lbitsize
!= rbitsize
3916 || lunsignedp
!= runsignedp
|| offset
!= 0
3917 || TREE_CODE (rinner
) == PLACEHOLDER_EXPR
)
3921 /* See if we can find a mode to refer to this field. We should be able to,
3922 but fail if we can't. */
3923 nmode
= get_best_mode (lbitsize
, lbitpos
,
3924 const_p
? TYPE_ALIGN (TREE_TYPE (linner
))
3925 : MIN (TYPE_ALIGN (TREE_TYPE (linner
)),
3926 TYPE_ALIGN (TREE_TYPE (rinner
))),
3927 word_mode
, lvolatilep
|| rvolatilep
);
3928 if (nmode
== VOIDmode
)
3931 /* Set signed and unsigned types of the precision of this mode for the
3933 signed_type
= lang_hooks
.types
.type_for_mode (nmode
, 0);
3934 unsigned_type
= lang_hooks
.types
.type_for_mode (nmode
, 1);
3936 /* Compute the bit position and size for the new reference and our offset
3937 within it. If the new reference is the same size as the original, we
3938 won't optimize anything, so return zero. */
3939 nbitsize
= GET_MODE_BITSIZE (nmode
);
3940 nbitpos
= lbitpos
& ~ (nbitsize
- 1);
3942 if (nbitsize
== lbitsize
)
3945 if (BYTES_BIG_ENDIAN
)
3946 lbitpos
= nbitsize
- lbitsize
- lbitpos
;
3948 /* Make the mask to be used against the extracted field. */
3949 mask
= build_int_cst_type (unsigned_type
, -1);
3950 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (nbitsize
- lbitsize
), 0);
3951 mask
= const_binop (RSHIFT_EXPR
, mask
,
3952 size_int (nbitsize
- lbitsize
- lbitpos
), 0);
3955 /* If not comparing with constant, just rework the comparison
3957 return fold_build2 (code
, compare_type
,
3958 fold_build2 (BIT_AND_EXPR
, unsigned_type
,
3959 make_bit_field_ref (linner
,
3964 fold_build2 (BIT_AND_EXPR
, unsigned_type
,
3965 make_bit_field_ref (rinner
,
3971 /* Otherwise, we are handling the constant case. See if the constant is too
3972 big for the field. Warn and return a tree of for 0 (false) if so. We do
3973 this not only for its own sake, but to avoid having to test for this
3974 error case below. If we didn't, we might generate wrong code.
3976 For unsigned fields, the constant shifted right by the field length should
3977 be all zero. For signed fields, the high-order bits should agree with
3982 if (! integer_zerop (const_binop (RSHIFT_EXPR
,
3983 fold_convert (unsigned_type
, rhs
),
3984 size_int (lbitsize
), 0)))
3986 warning (0, "comparison is always %d due to width of bit-field",
3988 return constant_boolean_node (code
== NE_EXPR
, compare_type
);
3993 tree tem
= const_binop (RSHIFT_EXPR
, fold_convert (signed_type
, rhs
),
3994 size_int (lbitsize
- 1), 0);
3995 if (! integer_zerop (tem
) && ! integer_all_onesp (tem
))
3997 warning (0, "comparison is always %d due to width of bit-field",
3999 return constant_boolean_node (code
== NE_EXPR
, compare_type
);
4003 /* Single-bit compares should always be against zero. */
4004 if (lbitsize
== 1 && ! integer_zerop (rhs
))
4006 code
= code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
;
4007 rhs
= build_int_cst (type
, 0);
4010 /* Make a new bitfield reference, shift the constant over the
4011 appropriate number of bits and mask it with the computed mask
4012 (in case this was a signed field). If we changed it, make a new one. */
4013 lhs
= make_bit_field_ref (linner
, unsigned_type
, nbitsize
, nbitpos
, 1);
4016 TREE_SIDE_EFFECTS (lhs
) = 1;
4017 TREE_THIS_VOLATILE (lhs
) = 1;
4020 rhs
= const_binop (BIT_AND_EXPR
,
4021 const_binop (LSHIFT_EXPR
,
4022 fold_convert (unsigned_type
, rhs
),
4023 size_int (lbitpos
), 0),
4026 return build2 (code
, compare_type
,
4027 build2 (BIT_AND_EXPR
, unsigned_type
, lhs
, mask
),
4031 /* Subroutine for fold_truthop: decode a field reference.
4033 If EXP is a comparison reference, we return the innermost reference.
4035 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
4036 set to the starting bit number.
4038 If the innermost field can be completely contained in a mode-sized
4039 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
4041 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
4042 otherwise it is not changed.
4044 *PUNSIGNEDP is set to the signedness of the field.
4046 *PMASK is set to the mask used. This is either contained in a
4047 BIT_AND_EXPR or derived from the width of the field.
4049 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
4051 Return 0 if this is not a component reference or is one that we can't
4052 do anything with. */
4055 decode_field_reference (tree exp
, HOST_WIDE_INT
*pbitsize
,
4056 HOST_WIDE_INT
*pbitpos
, enum machine_mode
*pmode
,
4057 int *punsignedp
, int *pvolatilep
,
4058 tree
*pmask
, tree
*pand_mask
)
4060 tree outer_type
= 0;
4062 tree mask
, inner
, offset
;
4064 unsigned int precision
;
4066 /* All the optimizations using this function assume integer fields.
4067 There are problems with FP fields since the type_for_size call
4068 below can fail for, e.g., XFmode. */
4069 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp
)))
4072 /* We are interested in the bare arrangement of bits, so strip everything
4073 that doesn't affect the machine mode. However, record the type of the
4074 outermost expression if it may matter below. */
4075 if (TREE_CODE (exp
) == NOP_EXPR
4076 || TREE_CODE (exp
) == CONVERT_EXPR
4077 || TREE_CODE (exp
) == NON_LVALUE_EXPR
)
4078 outer_type
= TREE_TYPE (exp
);
4081 if (TREE_CODE (exp
) == BIT_AND_EXPR
)
4083 and_mask
= TREE_OPERAND (exp
, 1);
4084 exp
= TREE_OPERAND (exp
, 0);
4085 STRIP_NOPS (exp
); STRIP_NOPS (and_mask
);
4086 if (TREE_CODE (and_mask
) != INTEGER_CST
)
4090 inner
= get_inner_reference (exp
, pbitsize
, pbitpos
, &offset
, pmode
,
4091 punsignedp
, pvolatilep
, false);
4092 if ((inner
== exp
&& and_mask
== 0)
4093 || *pbitsize
< 0 || offset
!= 0
4094 || TREE_CODE (inner
) == PLACEHOLDER_EXPR
)
4097 /* If the number of bits in the reference is the same as the bitsize of
4098 the outer type, then the outer type gives the signedness. Otherwise
4099 (in case of a small bitfield) the signedness is unchanged. */
4100 if (outer_type
&& *pbitsize
== TYPE_PRECISION (outer_type
))
4101 *punsignedp
= TYPE_UNSIGNED (outer_type
);
4103 /* Compute the mask to access the bitfield. */
4104 unsigned_type
= lang_hooks
.types
.type_for_size (*pbitsize
, 1);
4105 precision
= TYPE_PRECISION (unsigned_type
);
4107 mask
= build_int_cst_type (unsigned_type
, -1);
4109 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
4110 mask
= const_binop (RSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
4112 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
4114 mask
= fold_build2 (BIT_AND_EXPR
, unsigned_type
,
4115 fold_convert (unsigned_type
, and_mask
), mask
);
4118 *pand_mask
= and_mask
;
4122 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
4126 all_ones_mask_p (tree mask
, int size
)
4128 tree type
= TREE_TYPE (mask
);
4129 unsigned int precision
= TYPE_PRECISION (type
);
4132 tmask
= build_int_cst_type (signed_type_for (type
), -1);
4135 tree_int_cst_equal (mask
,
4136 const_binop (RSHIFT_EXPR
,
4137 const_binop (LSHIFT_EXPR
, tmask
,
4138 size_int (precision
- size
),
4140 size_int (precision
- size
), 0));
4143 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
4144 represents the sign bit of EXP's type. If EXP represents a sign
4145 or zero extension, also test VAL against the unextended type.
4146 The return value is the (sub)expression whose sign bit is VAL,
4147 or NULL_TREE otherwise. */
4150 sign_bit_p (tree exp
, tree val
)
4152 unsigned HOST_WIDE_INT mask_lo
, lo
;
4153 HOST_WIDE_INT mask_hi
, hi
;
4157 /* Tree EXP must have an integral type. */
4158 t
= TREE_TYPE (exp
);
4159 if (! INTEGRAL_TYPE_P (t
))
4162 /* Tree VAL must be an integer constant. */
4163 if (TREE_CODE (val
) != INTEGER_CST
4164 || TREE_OVERFLOW (val
))
4167 width
= TYPE_PRECISION (t
);
4168 if (width
> HOST_BITS_PER_WIDE_INT
)
4170 hi
= (unsigned HOST_WIDE_INT
) 1 << (width
- HOST_BITS_PER_WIDE_INT
- 1);
4173 mask_hi
= ((unsigned HOST_WIDE_INT
) -1
4174 >> (2 * HOST_BITS_PER_WIDE_INT
- width
));
4180 lo
= (unsigned HOST_WIDE_INT
) 1 << (width
- 1);
4183 mask_lo
= ((unsigned HOST_WIDE_INT
) -1
4184 >> (HOST_BITS_PER_WIDE_INT
- width
));
4187 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
4188 treat VAL as if it were unsigned. */
4189 if ((TREE_INT_CST_HIGH (val
) & mask_hi
) == hi
4190 && (TREE_INT_CST_LOW (val
) & mask_lo
) == lo
)
4193 /* Handle extension from a narrower type. */
4194 if (TREE_CODE (exp
) == NOP_EXPR
4195 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp
, 0))) < width
)
4196 return sign_bit_p (TREE_OPERAND (exp
, 0), val
);
4201 /* Subroutine for fold_truthop: determine if an operand is simple enough
4202 to be evaluated unconditionally. */
4205 simple_operand_p (tree exp
)
4207 /* Strip any conversions that don't change the machine mode. */
4210 return (CONSTANT_CLASS_P (exp
)
4211 || TREE_CODE (exp
) == SSA_NAME
4213 && ! TREE_ADDRESSABLE (exp
)
4214 && ! TREE_THIS_VOLATILE (exp
)
4215 && ! DECL_NONLOCAL (exp
)
4216 /* Don't regard global variables as simple. They may be
4217 allocated in ways unknown to the compiler (shared memory,
4218 #pragma weak, etc). */
4219 && ! TREE_PUBLIC (exp
)
4220 && ! DECL_EXTERNAL (exp
)
4221 /* Loading a static variable is unduly expensive, but global
4222 registers aren't expensive. */
4223 && (! TREE_STATIC (exp
) || DECL_REGISTER (exp
))));
4226 /* The following functions are subroutines to fold_range_test and allow it to
4227 try to change a logical combination of comparisons into a range test.
4230 X == 2 || X == 3 || X == 4 || X == 5
4234 (unsigned) (X - 2) <= 3
4236 We describe each set of comparisons as being either inside or outside
4237 a range, using a variable named like IN_P, and then describe the
4238 range with a lower and upper bound. If one of the bounds is omitted,
4239 it represents either the highest or lowest value of the type.
4241 In the comments below, we represent a range by two numbers in brackets
4242 preceded by a "+" to designate being inside that range, or a "-" to
4243 designate being outside that range, so the condition can be inverted by
4244 flipping the prefix. An omitted bound is represented by a "-". For
4245 example, "- [-, 10]" means being outside the range starting at the lowest
4246 possible value and ending at 10, in other words, being greater than 10.
4247 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
4250 We set up things so that the missing bounds are handled in a consistent
4251 manner so neither a missing bound nor "true" and "false" need to be
4252 handled using a special case. */
4254 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
4255 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
4256 and UPPER1_P are nonzero if the respective argument is an upper bound
4257 and zero for a lower. TYPE, if nonzero, is the type of the result; it
4258 must be specified for a comparison. ARG1 will be converted to ARG0's
4259 type if both are specified. */
4262 range_binop (enum tree_code code
, tree type
, tree arg0
, int upper0_p
,
4263 tree arg1
, int upper1_p
)
4269 /* If neither arg represents infinity, do the normal operation.
4270 Else, if not a comparison, return infinity. Else handle the special
4271 comparison rules. Note that most of the cases below won't occur, but
4272 are handled for consistency. */
4274 if (arg0
!= 0 && arg1
!= 0)
4276 tem
= fold_build2 (code
, type
!= 0 ? type
: TREE_TYPE (arg0
),
4277 arg0
, fold_convert (TREE_TYPE (arg0
), arg1
));
4279 return TREE_CODE (tem
) == INTEGER_CST
? tem
: 0;
4282 if (TREE_CODE_CLASS (code
) != tcc_comparison
)
4285 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
4286 for neither. In real maths, we cannot assume open ended ranges are
4287 the same. But, this is computer arithmetic, where numbers are finite.
4288 We can therefore make the transformation of any unbounded range with
4289 the value Z, Z being greater than any representable number. This permits
4290 us to treat unbounded ranges as equal. */
4291 sgn0
= arg0
!= 0 ? 0 : (upper0_p
? 1 : -1);
4292 sgn1
= arg1
!= 0 ? 0 : (upper1_p
? 1 : -1);
4296 result
= sgn0
== sgn1
;
4299 result
= sgn0
!= sgn1
;
4302 result
= sgn0
< sgn1
;
4305 result
= sgn0
<= sgn1
;
4308 result
= sgn0
> sgn1
;
4311 result
= sgn0
>= sgn1
;
4317 return constant_boolean_node (result
, type
);
4320 /* Given EXP, a logical expression, set the range it is testing into
4321 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
4322 actually being tested. *PLOW and *PHIGH will be made of the same
4323 type as the returned expression. If EXP is not a comparison, we
4324 will most likely not be returning a useful value and range. Set
4325 *STRICT_OVERFLOW_P to true if the return value is only valid
4326 because signed overflow is undefined; otherwise, do not change
4327 *STRICT_OVERFLOW_P. */
4330 make_range (tree exp
, int *pin_p
, tree
*plow
, tree
*phigh
,
4331 bool *strict_overflow_p
)
4333 enum tree_code code
;
4334 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
;
4335 tree exp_type
= NULL_TREE
, arg0_type
= NULL_TREE
;
4337 tree low
, high
, n_low
, n_high
;
4339 /* Start with simply saying "EXP != 0" and then look at the code of EXP
4340 and see if we can refine the range. Some of the cases below may not
4341 happen, but it doesn't seem worth worrying about this. We "continue"
4342 the outer loop when we've changed something; otherwise we "break"
4343 the switch, which will "break" the while. */
4346 low
= high
= build_int_cst (TREE_TYPE (exp
), 0);
4350 code
= TREE_CODE (exp
);
4351 exp_type
= TREE_TYPE (exp
);
4353 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code
)))
4355 if (TREE_OPERAND_LENGTH (exp
) > 0)
4356 arg0
= TREE_OPERAND (exp
, 0);
4357 if (TREE_CODE_CLASS (code
) == tcc_comparison
4358 || TREE_CODE_CLASS (code
) == tcc_unary
4359 || TREE_CODE_CLASS (code
) == tcc_binary
)
4360 arg0_type
= TREE_TYPE (arg0
);
4361 if (TREE_CODE_CLASS (code
) == tcc_binary
4362 || TREE_CODE_CLASS (code
) == tcc_comparison
4363 || (TREE_CODE_CLASS (code
) == tcc_expression
4364 && TREE_OPERAND_LENGTH (exp
) > 1))
4365 arg1
= TREE_OPERAND (exp
, 1);
4370 case TRUTH_NOT_EXPR
:
4371 in_p
= ! in_p
, exp
= arg0
;
4374 case EQ_EXPR
: case NE_EXPR
:
4375 case LT_EXPR
: case LE_EXPR
: case GE_EXPR
: case GT_EXPR
:
4376 /* We can only do something if the range is testing for zero
4377 and if the second operand is an integer constant. Note that
4378 saying something is "in" the range we make is done by
4379 complementing IN_P since it will set in the initial case of
4380 being not equal to zero; "out" is leaving it alone. */
4381 if (low
== 0 || high
== 0
4382 || ! integer_zerop (low
) || ! integer_zerop (high
)
4383 || TREE_CODE (arg1
) != INTEGER_CST
)
4388 case NE_EXPR
: /* - [c, c] */
4391 case EQ_EXPR
: /* + [c, c] */
4392 in_p
= ! in_p
, low
= high
= arg1
;
4394 case GT_EXPR
: /* - [-, c] */
4395 low
= 0, high
= arg1
;
4397 case GE_EXPR
: /* + [c, -] */
4398 in_p
= ! in_p
, low
= arg1
, high
= 0;
4400 case LT_EXPR
: /* - [c, -] */
4401 low
= arg1
, high
= 0;
4403 case LE_EXPR
: /* + [-, c] */
4404 in_p
= ! in_p
, low
= 0, high
= arg1
;
4410 /* If this is an unsigned comparison, we also know that EXP is
4411 greater than or equal to zero. We base the range tests we make
4412 on that fact, so we record it here so we can parse existing
4413 range tests. We test arg0_type since often the return type
4414 of, e.g. EQ_EXPR, is boolean. */
4415 if (TYPE_UNSIGNED (arg0_type
) && (low
== 0 || high
== 0))
4417 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
4419 build_int_cst (arg0_type
, 0),
4423 in_p
= n_in_p
, low
= n_low
, high
= n_high
;
4425 /* If the high bound is missing, but we have a nonzero low
4426 bound, reverse the range so it goes from zero to the low bound
4428 if (high
== 0 && low
&& ! integer_zerop (low
))
4431 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low
, 0,
4432 integer_one_node
, 0);
4433 low
= build_int_cst (arg0_type
, 0);
4441 /* (-x) IN [a,b] -> x in [-b, -a] */
4442 n_low
= range_binop (MINUS_EXPR
, exp_type
,
4443 build_int_cst (exp_type
, 0),
4445 n_high
= range_binop (MINUS_EXPR
, exp_type
,
4446 build_int_cst (exp_type
, 0),
4448 low
= n_low
, high
= n_high
;
4454 exp
= build2 (MINUS_EXPR
, exp_type
, negate_expr (arg0
),
4455 build_int_cst (exp_type
, 1));
4458 case PLUS_EXPR
: case MINUS_EXPR
:
4459 if (TREE_CODE (arg1
) != INTEGER_CST
)
4462 /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
4463 move a constant to the other side. */
4464 if (!TYPE_UNSIGNED (arg0_type
)
4465 && !TYPE_OVERFLOW_UNDEFINED (arg0_type
))
4468 /* If EXP is signed, any overflow in the computation is undefined,
4469 so we don't worry about it so long as our computations on
4470 the bounds don't overflow. For unsigned, overflow is defined
4471 and this is exactly the right thing. */
4472 n_low
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
4473 arg0_type
, low
, 0, arg1
, 0);
4474 n_high
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
4475 arg0_type
, high
, 1, arg1
, 0);
4476 if ((n_low
!= 0 && TREE_OVERFLOW (n_low
))
4477 || (n_high
!= 0 && TREE_OVERFLOW (n_high
)))
4480 if (TYPE_OVERFLOW_UNDEFINED (arg0_type
))
4481 *strict_overflow_p
= true;
4483 /* Check for an unsigned range which has wrapped around the maximum
4484 value thus making n_high < n_low, and normalize it. */
4485 if (n_low
&& n_high
&& tree_int_cst_lt (n_high
, n_low
))
4487 low
= range_binop (PLUS_EXPR
, arg0_type
, n_high
, 0,
4488 integer_one_node
, 0);
4489 high
= range_binop (MINUS_EXPR
, arg0_type
, n_low
, 0,
4490 integer_one_node
, 0);
4492 /* If the range is of the form +/- [ x+1, x ], we won't
4493 be able to normalize it. But then, it represents the
4494 whole range or the empty set, so make it
4496 if (tree_int_cst_equal (n_low
, low
)
4497 && tree_int_cst_equal (n_high
, high
))
4503 low
= n_low
, high
= n_high
;
4508 case NOP_EXPR
: case NON_LVALUE_EXPR
: case CONVERT_EXPR
:
4509 if (TYPE_PRECISION (arg0_type
) > TYPE_PRECISION (exp_type
))
4512 if (! INTEGRAL_TYPE_P (arg0_type
)
4513 || (low
!= 0 && ! int_fits_type_p (low
, arg0_type
))
4514 || (high
!= 0 && ! int_fits_type_p (high
, arg0_type
)))
4517 n_low
= low
, n_high
= high
;
4520 n_low
= fold_convert (arg0_type
, n_low
);
4523 n_high
= fold_convert (arg0_type
, n_high
);
4526 /* If we're converting arg0 from an unsigned type, to exp,
4527 a signed type, we will be doing the comparison as unsigned.
4528 The tests above have already verified that LOW and HIGH
4531 So we have to ensure that we will handle large unsigned
4532 values the same way that the current signed bounds treat
4535 if (!TYPE_UNSIGNED (exp_type
) && TYPE_UNSIGNED (arg0_type
))
4539 /* For fixed-point modes, we need to pass the saturating flag
4540 as the 2nd parameter. */
4541 if (ALL_FIXED_POINT_MODE_P (TYPE_MODE (arg0_type
)))
4542 equiv_type
= lang_hooks
.types
.type_for_mode
4543 (TYPE_MODE (arg0_type
),
4544 TYPE_SATURATING (arg0_type
));
4546 equiv_type
= lang_hooks
.types
.type_for_mode
4547 (TYPE_MODE (arg0_type
), 1);
4549 /* A range without an upper bound is, naturally, unbounded.
4550 Since convert would have cropped a very large value, use
4551 the max value for the destination type. */
4553 = TYPE_MAX_VALUE (equiv_type
) ? TYPE_MAX_VALUE (equiv_type
)
4554 : TYPE_MAX_VALUE (arg0_type
);
4556 if (TYPE_PRECISION (exp_type
) == TYPE_PRECISION (arg0_type
))
4557 high_positive
= fold_build2 (RSHIFT_EXPR
, arg0_type
,
4558 fold_convert (arg0_type
,
4560 build_int_cst (arg0_type
, 1));
4562 /* If the low bound is specified, "and" the range with the
4563 range for which the original unsigned value will be
4567 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
4568 1, n_low
, n_high
, 1,
4569 fold_convert (arg0_type
,
4574 in_p
= (n_in_p
== in_p
);
4578 /* Otherwise, "or" the range with the range of the input
4579 that will be interpreted as negative. */
4580 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
4581 0, n_low
, n_high
, 1,
4582 fold_convert (arg0_type
,
4587 in_p
= (in_p
!= n_in_p
);
4592 low
= n_low
, high
= n_high
;
4602 /* If EXP is a constant, we can evaluate whether this is true or false. */
4603 if (TREE_CODE (exp
) == INTEGER_CST
)
4605 in_p
= in_p
== (integer_onep (range_binop (GE_EXPR
, integer_type_node
,
4607 && integer_onep (range_binop (LE_EXPR
, integer_type_node
,
4613 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
4617 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
4618 type, TYPE, return an expression to test if EXP is in (or out of, depending
4619 on IN_P) the range. Return 0 if the test couldn't be created. */
4622 build_range_check (tree type
, tree exp
, int in_p
, tree low
, tree high
)
4624 tree etype
= TREE_TYPE (exp
);
4627 #ifdef HAVE_canonicalize_funcptr_for_compare
4628 /* Disable this optimization for function pointer expressions
4629 on targets that require function pointer canonicalization. */
4630 if (HAVE_canonicalize_funcptr_for_compare
4631 && TREE_CODE (etype
) == POINTER_TYPE
4632 && TREE_CODE (TREE_TYPE (etype
)) == FUNCTION_TYPE
)
4638 value
= build_range_check (type
, exp
, 1, low
, high
);
4640 return invert_truthvalue (value
);
4645 if (low
== 0 && high
== 0)
4646 return build_int_cst (type
, 1);
4649 return fold_build2 (LE_EXPR
, type
, exp
,
4650 fold_convert (etype
, high
));
4653 return fold_build2 (GE_EXPR
, type
, exp
,
4654 fold_convert (etype
, low
));
4656 if (operand_equal_p (low
, high
, 0))
4657 return fold_build2 (EQ_EXPR
, type
, exp
,
4658 fold_convert (etype
, low
));
4660 if (integer_zerop (low
))
4662 if (! TYPE_UNSIGNED (etype
))
4664 etype
= unsigned_type_for (etype
);
4665 high
= fold_convert (etype
, high
);
4666 exp
= fold_convert (etype
, exp
);
4668 return build_range_check (type
, exp
, 1, 0, high
);
4671 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
4672 if (integer_onep (low
) && TREE_CODE (high
) == INTEGER_CST
)
4674 unsigned HOST_WIDE_INT lo
;
4678 prec
= TYPE_PRECISION (etype
);
4679 if (prec
<= HOST_BITS_PER_WIDE_INT
)
4682 lo
= ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1)) - 1;
4686 hi
= ((HOST_WIDE_INT
) 1 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)) - 1;
4687 lo
= (unsigned HOST_WIDE_INT
) -1;
4690 if (TREE_INT_CST_HIGH (high
) == hi
&& TREE_INT_CST_LOW (high
) == lo
)
4692 if (TYPE_UNSIGNED (etype
))
4694 etype
= signed_type_for (etype
);
4695 exp
= fold_convert (etype
, exp
);
4697 return fold_build2 (GT_EXPR
, type
, exp
,
4698 build_int_cst (etype
, 0));
4702 /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
4703 This requires wrap-around arithmetics for the type of the expression. */
4704 switch (TREE_CODE (etype
))
4707 /* There is no requirement that LOW be within the range of ETYPE
4708 if the latter is a subtype. It must, however, be within the base
4709 type of ETYPE. So be sure we do the subtraction in that type. */
4710 if (TREE_TYPE (etype
))
4711 etype
= TREE_TYPE (etype
);
4716 etype
= lang_hooks
.types
.type_for_size (TYPE_PRECISION (etype
),
4717 TYPE_UNSIGNED (etype
));
4724 /* If we don't have wrap-around arithmetics upfront, try to force it. */
4725 if (TREE_CODE (etype
) == INTEGER_TYPE
4726 && !TYPE_OVERFLOW_WRAPS (etype
))
4728 tree utype
, minv
, maxv
;
4730 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
4731 for the type in question, as we rely on this here. */
4732 utype
= unsigned_type_for (etype
);
4733 maxv
= fold_convert (utype
, TYPE_MAX_VALUE (etype
));
4734 maxv
= range_binop (PLUS_EXPR
, NULL_TREE
, maxv
, 1,
4735 integer_one_node
, 1);
4736 minv
= fold_convert (utype
, TYPE_MIN_VALUE (etype
));
4738 if (integer_zerop (range_binop (NE_EXPR
, integer_type_node
,
4745 high
= fold_convert (etype
, high
);
4746 low
= fold_convert (etype
, low
);
4747 exp
= fold_convert (etype
, exp
);
4749 value
= const_binop (MINUS_EXPR
, high
, low
, 0);
4752 if (POINTER_TYPE_P (etype
))
4754 if (value
!= 0 && !TREE_OVERFLOW (value
))
4756 low
= fold_convert (sizetype
, low
);
4757 low
= fold_build1 (NEGATE_EXPR
, sizetype
, low
);
4758 return build_range_check (type
,
4759 fold_build2 (POINTER_PLUS_EXPR
, etype
, exp
, low
),
4760 1, build_int_cst (etype
, 0), value
);
4765 if (value
!= 0 && !TREE_OVERFLOW (value
))
4766 return build_range_check (type
,
4767 fold_build2 (MINUS_EXPR
, etype
, exp
, low
),
4768 1, build_int_cst (etype
, 0), value
);
4773 /* Return the predecessor of VAL in its type, handling the infinite case. */
4776 range_predecessor (tree val
)
4778 tree type
= TREE_TYPE (val
);
4780 if (INTEGRAL_TYPE_P (type
)
4781 && operand_equal_p (val
, TYPE_MIN_VALUE (type
), 0))
4784 return range_binop (MINUS_EXPR
, NULL_TREE
, val
, 0, integer_one_node
, 0);
4787 /* Return the successor of VAL in its type, handling the infinite case. */
4790 range_successor (tree val
)
4792 tree type
= TREE_TYPE (val
);
4794 if (INTEGRAL_TYPE_P (type
)
4795 && operand_equal_p (val
, TYPE_MAX_VALUE (type
), 0))
4798 return range_binop (PLUS_EXPR
, NULL_TREE
, val
, 0, integer_one_node
, 0);
4801 /* Given two ranges, see if we can merge them into one. Return 1 if we
4802 can, 0 if we can't. Set the output range into the specified parameters. */
4805 merge_ranges (int *pin_p
, tree
*plow
, tree
*phigh
, int in0_p
, tree low0
,
4806 tree high0
, int in1_p
, tree low1
, tree high1
)
4814 int lowequal
= ((low0
== 0 && low1
== 0)
4815 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
4816 low0
, 0, low1
, 0)));
4817 int highequal
= ((high0
== 0 && high1
== 0)
4818 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
4819 high0
, 1, high1
, 1)));
4821 /* Make range 0 be the range that starts first, or ends last if they
4822 start at the same value. Swap them if it isn't. */
4823 if (integer_onep (range_binop (GT_EXPR
, integer_type_node
,
4826 && integer_onep (range_binop (GT_EXPR
, integer_type_node
,
4827 high1
, 1, high0
, 1))))
4829 temp
= in0_p
, in0_p
= in1_p
, in1_p
= temp
;
4830 tem
= low0
, low0
= low1
, low1
= tem
;
4831 tem
= high0
, high0
= high1
, high1
= tem
;
4834 /* Now flag two cases, whether the ranges are disjoint or whether the
4835 second range is totally subsumed in the first. Note that the tests
4836 below are simplified by the ones above. */
4837 no_overlap
= integer_onep (range_binop (LT_EXPR
, integer_type_node
,
4838 high0
, 1, low1
, 0));
4839 subset
= integer_onep (range_binop (LE_EXPR
, integer_type_node
,
4840 high1
, 1, high0
, 1));
4842 /* We now have four cases, depending on whether we are including or
4843 excluding the two ranges. */
4846 /* If they don't overlap, the result is false. If the second range
4847 is a subset it is the result. Otherwise, the range is from the start
4848 of the second to the end of the first. */
4850 in_p
= 0, low
= high
= 0;
4852 in_p
= 1, low
= low1
, high
= high1
;
4854 in_p
= 1, low
= low1
, high
= high0
;
4857 else if (in0_p
&& ! in1_p
)
4859 /* If they don't overlap, the result is the first range. If they are
4860 equal, the result is false. If the second range is a subset of the
4861 first, and the ranges begin at the same place, we go from just after
4862 the end of the second range to the end of the first. If the second
4863 range is not a subset of the first, or if it is a subset and both
4864 ranges end at the same place, the range starts at the start of the
4865 first range and ends just before the second range.
4866 Otherwise, we can't describe this as a single range. */
4868 in_p
= 1, low
= low0
, high
= high0
;
4869 else if (lowequal
&& highequal
)
4870 in_p
= 0, low
= high
= 0;
4871 else if (subset
&& lowequal
)
4873 low
= range_successor (high1
);
4878 /* We are in the weird situation where high0 > high1 but
4879 high1 has no successor. Punt. */
4883 else if (! subset
|| highequal
)
4886 high
= range_predecessor (low1
);
4890 /* low0 < low1 but low1 has no predecessor. Punt. */
4898 else if (! in0_p
&& in1_p
)
4900 /* If they don't overlap, the result is the second range. If the second
4901 is a subset of the first, the result is false. Otherwise,
4902 the range starts just after the first range and ends at the
4903 end of the second. */
4905 in_p
= 1, low
= low1
, high
= high1
;
4906 else if (subset
|| highequal
)
4907 in_p
= 0, low
= high
= 0;
4910 low
= range_successor (high0
);
4915 /* high1 > high0 but high0 has no successor. Punt. */
4923 /* The case where we are excluding both ranges. Here the complex case
4924 is if they don't overlap. In that case, the only time we have a
4925 range is if they are adjacent. If the second is a subset of the
4926 first, the result is the first. Otherwise, the range to exclude
4927 starts at the beginning of the first range and ends at the end of the
4931 if (integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
4932 range_successor (high0
),
4934 in_p
= 0, low
= low0
, high
= high1
;
4937 /* Canonicalize - [min, x] into - [-, x]. */
4938 if (low0
&& TREE_CODE (low0
) == INTEGER_CST
)
4939 switch (TREE_CODE (TREE_TYPE (low0
)))
4942 if (TYPE_PRECISION (TREE_TYPE (low0
))
4943 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0
))))
4947 if (tree_int_cst_equal (low0
,
4948 TYPE_MIN_VALUE (TREE_TYPE (low0
))))
4952 if (TYPE_UNSIGNED (TREE_TYPE (low0
))
4953 && integer_zerop (low0
))
4960 /* Canonicalize - [x, max] into - [x, -]. */
4961 if (high1
&& TREE_CODE (high1
) == INTEGER_CST
)
4962 switch (TREE_CODE (TREE_TYPE (high1
)))
4965 if (TYPE_PRECISION (TREE_TYPE (high1
))
4966 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1
))))
4970 if (tree_int_cst_equal (high1
,
4971 TYPE_MAX_VALUE (TREE_TYPE (high1
))))
4975 if (TYPE_UNSIGNED (TREE_TYPE (high1
))
4976 && integer_zerop (range_binop (PLUS_EXPR
, NULL_TREE
,
4978 integer_one_node
, 1)))
4985 /* The ranges might be also adjacent between the maximum and
4986 minimum values of the given type. For
4987 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4988 return + [x + 1, y - 1]. */
4989 if (low0
== 0 && high1
== 0)
4991 low
= range_successor (high0
);
4992 high
= range_predecessor (low1
);
4993 if (low
== 0 || high
== 0)
5003 in_p
= 0, low
= low0
, high
= high0
;
5005 in_p
= 0, low
= low0
, high
= high1
;
5008 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
5013 /* Subroutine of fold, looking inside expressions of the form
5014 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
5015 of the COND_EXPR. This function is being used also to optimize
5016 A op B ? C : A, by reversing the comparison first.
5018 Return a folded expression whose code is not a COND_EXPR
5019 anymore, or NULL_TREE if no folding opportunity is found. */
5022 fold_cond_expr_with_comparison (tree type
, tree arg0
, tree arg1
, tree arg2
)
5024 enum tree_code comp_code
= TREE_CODE (arg0
);
5025 tree arg00
= TREE_OPERAND (arg0
, 0);
5026 tree arg01
= TREE_OPERAND (arg0
, 1);
5027 tree arg1_type
= TREE_TYPE (arg1
);
5033 /* If we have A op 0 ? A : -A, consider applying the following
5036 A == 0? A : -A same as -A
5037 A != 0? A : -A same as A
5038 A >= 0? A : -A same as abs (A)
5039 A > 0? A : -A same as abs (A)
5040 A <= 0? A : -A same as -abs (A)
5041 A < 0? A : -A same as -abs (A)
5043 None of these transformations work for modes with signed
5044 zeros. If A is +/-0, the first two transformations will
5045 change the sign of the result (from +0 to -0, or vice
5046 versa). The last four will fix the sign of the result,
5047 even though the original expressions could be positive or
5048 negative, depending on the sign of A.
5050 Note that all these transformations are correct if A is
5051 NaN, since the two alternatives (A and -A) are also NaNs. */
5052 if ((FLOAT_TYPE_P (TREE_TYPE (arg01
))
5053 ? real_zerop (arg01
)
5054 : integer_zerop (arg01
))
5055 && ((TREE_CODE (arg2
) == NEGATE_EXPR
5056 && operand_equal_p (TREE_OPERAND (arg2
, 0), arg1
, 0))
5057 /* In the case that A is of the form X-Y, '-A' (arg2) may
5058 have already been folded to Y-X, check for that. */
5059 || (TREE_CODE (arg1
) == MINUS_EXPR
5060 && TREE_CODE (arg2
) == MINUS_EXPR
5061 && operand_equal_p (TREE_OPERAND (arg1
, 0),
5062 TREE_OPERAND (arg2
, 1), 0)
5063 && operand_equal_p (TREE_OPERAND (arg1
, 1),
5064 TREE_OPERAND (arg2
, 0), 0))))
5069 tem
= fold_convert (arg1_type
, arg1
);
5070 return pedantic_non_lvalue (fold_convert (type
, negate_expr (tem
)));
5073 return pedantic_non_lvalue (fold_convert (type
, arg1
));
5076 if (flag_trapping_math
)
5081 if (TYPE_UNSIGNED (TREE_TYPE (arg1
)))
5082 arg1
= fold_convert (signed_type_for
5083 (TREE_TYPE (arg1
)), arg1
);
5084 tem
= fold_build1 (ABS_EXPR
, TREE_TYPE (arg1
), arg1
);
5085 return pedantic_non_lvalue (fold_convert (type
, tem
));
5088 if (flag_trapping_math
)
5092 if (TYPE_UNSIGNED (TREE_TYPE (arg1
)))
5093 arg1
= fold_convert (signed_type_for
5094 (TREE_TYPE (arg1
)), arg1
);
5095 tem
= fold_build1 (ABS_EXPR
, TREE_TYPE (arg1
), arg1
);
5096 return negate_expr (fold_convert (type
, tem
));
5098 gcc_assert (TREE_CODE_CLASS (comp_code
) == tcc_comparison
);
5102 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
5103 A == 0 ? A : 0 is always 0 unless A is -0. Note that
5104 both transformations are correct when A is NaN: A != 0
5105 is then true, and A == 0 is false. */
5107 if (integer_zerop (arg01
) && integer_zerop (arg2
))
5109 if (comp_code
== NE_EXPR
)
5110 return pedantic_non_lvalue (fold_convert (type
, arg1
));
5111 else if (comp_code
== EQ_EXPR
)
5112 return build_int_cst (type
, 0);
5115 /* Try some transformations of A op B ? A : B.
5117 A == B? A : B same as B
5118 A != B? A : B same as A
5119 A >= B? A : B same as max (A, B)
5120 A > B? A : B same as max (B, A)
5121 A <= B? A : B same as min (A, B)
5122 A < B? A : B same as min (B, A)
5124 As above, these transformations don't work in the presence
5125 of signed zeros. For example, if A and B are zeros of
5126 opposite sign, the first two transformations will change
5127 the sign of the result. In the last four, the original
5128 expressions give different results for (A=+0, B=-0) and
5129 (A=-0, B=+0), but the transformed expressions do not.
5131 The first two transformations are correct if either A or B
5132 is a NaN. In the first transformation, the condition will
5133 be false, and B will indeed be chosen. In the case of the
5134 second transformation, the condition A != B will be true,
5135 and A will be chosen.
5137 The conversions to max() and min() are not correct if B is
5138 a number and A is not. The conditions in the original
5139 expressions will be false, so all four give B. The min()
5140 and max() versions would give a NaN instead. */
5141 if (operand_equal_for_comparison_p (arg01
, arg2
, arg00
)
5142 /* Avoid these transformations if the COND_EXPR may be used
5143 as an lvalue in the C++ front-end. PR c++/19199. */
5145 || (strcmp (lang_hooks
.name
, "GNU C++") != 0
5146 && strcmp (lang_hooks
.name
, "GNU Objective-C++") != 0)
5147 || ! maybe_lvalue_p (arg1
)
5148 || ! maybe_lvalue_p (arg2
)))
5150 tree comp_op0
= arg00
;
5151 tree comp_op1
= arg01
;
5152 tree comp_type
= TREE_TYPE (comp_op0
);
5154 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
5155 if (TYPE_MAIN_VARIANT (comp_type
) == TYPE_MAIN_VARIANT (type
))
5165 return pedantic_non_lvalue (fold_convert (type
, arg2
));
5167 return pedantic_non_lvalue (fold_convert (type
, arg1
));
5172 /* In C++ a ?: expression can be an lvalue, so put the
5173 operand which will be used if they are equal first
5174 so that we can convert this back to the
5175 corresponding COND_EXPR. */
5176 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
5178 comp_op0
= fold_convert (comp_type
, comp_op0
);
5179 comp_op1
= fold_convert (comp_type
, comp_op1
);
5180 tem
= (comp_code
== LE_EXPR
|| comp_code
== UNLE_EXPR
)
5181 ? fold_build2 (MIN_EXPR
, comp_type
, comp_op0
, comp_op1
)
5182 : fold_build2 (MIN_EXPR
, comp_type
, comp_op1
, comp_op0
);
5183 return pedantic_non_lvalue (fold_convert (type
, tem
));
5190 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
5192 comp_op0
= fold_convert (comp_type
, comp_op0
);
5193 comp_op1
= fold_convert (comp_type
, comp_op1
);
5194 tem
= (comp_code
== GE_EXPR
|| comp_code
== UNGE_EXPR
)
5195 ? fold_build2 (MAX_EXPR
, comp_type
, comp_op0
, comp_op1
)
5196 : fold_build2 (MAX_EXPR
, comp_type
, comp_op1
, comp_op0
);
5197 return pedantic_non_lvalue (fold_convert (type
, tem
));
5201 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
5202 return pedantic_non_lvalue (fold_convert (type
, arg2
));
5205 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
5206 return pedantic_non_lvalue (fold_convert (type
, arg1
));
5209 gcc_assert (TREE_CODE_CLASS (comp_code
) == tcc_comparison
);
5214 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
5215 we might still be able to simplify this. For example,
5216 if C1 is one less or one more than C2, this might have started
5217 out as a MIN or MAX and been transformed by this function.
5218 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
5220 if (INTEGRAL_TYPE_P (type
)
5221 && TREE_CODE (arg01
) == INTEGER_CST
5222 && TREE_CODE (arg2
) == INTEGER_CST
)
5226 /* We can replace A with C1 in this case. */
5227 arg1
= fold_convert (type
, arg01
);
5228 return fold_build3 (COND_EXPR
, type
, arg0
, arg1
, arg2
);
5231 /* If C1 is C2 + 1, this is min(A, C2). */
5232 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
),
5234 && operand_equal_p (arg01
,
5235 const_binop (PLUS_EXPR
, arg2
,
5236 build_int_cst (type
, 1), 0),
5238 return pedantic_non_lvalue (fold_build2 (MIN_EXPR
,
5240 fold_convert (type
, arg1
),
5245 /* If C1 is C2 - 1, this is min(A, C2). */
5246 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
),
5248 && operand_equal_p (arg01
,
5249 const_binop (MINUS_EXPR
, arg2
,
5250 build_int_cst (type
, 1), 0),
5252 return pedantic_non_lvalue (fold_build2 (MIN_EXPR
,
5254 fold_convert (type
, arg1
),
5259 /* If C1 is C2 - 1, this is max(A, C2). */
5260 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
),
5262 && operand_equal_p (arg01
,
5263 const_binop (MINUS_EXPR
, arg2
,
5264 build_int_cst (type
, 1), 0),
5266 return pedantic_non_lvalue (fold_build2 (MAX_EXPR
,
5268 fold_convert (type
, arg1
),
5273 /* If C1 is C2 + 1, this is max(A, C2). */
5274 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
),
5276 && operand_equal_p (arg01
,
5277 const_binop (PLUS_EXPR
, arg2
,
5278 build_int_cst (type
, 1), 0),
5280 return pedantic_non_lvalue (fold_build2 (MAX_EXPR
,
5282 fold_convert (type
, arg1
),
5296 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
5297 #define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
5300 /* EXP is some logical combination of boolean tests. See if we can
5301 merge it into some range test. Return the new tree if so. */
5304 fold_range_test (enum tree_code code
, tree type
, tree op0
, tree op1
)
5306 int or_op
= (code
== TRUTH_ORIF_EXPR
5307 || code
== TRUTH_OR_EXPR
);
5308 int in0_p
, in1_p
, in_p
;
5309 tree low0
, low1
, low
, high0
, high1
, high
;
5310 bool strict_overflow_p
= false;
5311 tree lhs
= make_range (op0
, &in0_p
, &low0
, &high0
, &strict_overflow_p
);
5312 tree rhs
= make_range (op1
, &in1_p
, &low1
, &high1
, &strict_overflow_p
);
5314 const char * const warnmsg
= G_("assuming signed overflow does not occur "
5315 "when simplifying range test");
5317 /* If this is an OR operation, invert both sides; we will invert
5318 again at the end. */
5320 in0_p
= ! in0_p
, in1_p
= ! in1_p
;
5322 /* If both expressions are the same, if we can merge the ranges, and we
5323 can build the range test, return it or it inverted. If one of the
5324 ranges is always true or always false, consider it to be the same
5325 expression as the other. */
5326 if ((lhs
== 0 || rhs
== 0 || operand_equal_p (lhs
, rhs
, 0))
5327 && merge_ranges (&in_p
, &low
, &high
, in0_p
, low0
, high0
,
5329 && 0 != (tem
= (build_range_check (type
,
5331 : rhs
!= 0 ? rhs
: integer_zero_node
,
5334 if (strict_overflow_p
)
5335 fold_overflow_warning (warnmsg
, WARN_STRICT_OVERFLOW_COMPARISON
);
5336 return or_op
? invert_truthvalue (tem
) : tem
;
5339 /* On machines where the branch cost is expensive, if this is a
5340 short-circuited branch and the underlying object on both sides
5341 is the same, make a non-short-circuit operation. */
5342 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
5343 && lhs
!= 0 && rhs
!= 0
5344 && (code
== TRUTH_ANDIF_EXPR
5345 || code
== TRUTH_ORIF_EXPR
)
5346 && operand_equal_p (lhs
, rhs
, 0))
5348 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
5349 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
5350 which cases we can't do this. */
5351 if (simple_operand_p (lhs
))
5352 return build2 (code
== TRUTH_ANDIF_EXPR
5353 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
5356 else if (lang_hooks
.decls
.global_bindings_p () == 0
5357 && ! CONTAINS_PLACEHOLDER_P (lhs
))
5359 tree common
= save_expr (lhs
);
5361 if (0 != (lhs
= build_range_check (type
, common
,
5362 or_op
? ! in0_p
: in0_p
,
5364 && (0 != (rhs
= build_range_check (type
, common
,
5365 or_op
? ! in1_p
: in1_p
,
5368 if (strict_overflow_p
)
5369 fold_overflow_warning (warnmsg
,
5370 WARN_STRICT_OVERFLOW_COMPARISON
);
5371 return build2 (code
== TRUTH_ANDIF_EXPR
5372 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
5381 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
5382 bit value. Arrange things so the extra bits will be set to zero if and
5383 only if C is signed-extended to its full width. If MASK is nonzero,
5384 it is an INTEGER_CST that should be AND'ed with the extra bits. */
5387 unextend (tree c
, int p
, int unsignedp
, tree mask
)
5389 tree type
= TREE_TYPE (c
);
5390 int modesize
= GET_MODE_BITSIZE (TYPE_MODE (type
));
5393 if (p
== modesize
|| unsignedp
)
5396 /* We work by getting just the sign bit into the low-order bit, then
5397 into the high-order bit, then sign-extend. We then XOR that value
5399 temp
= const_binop (RSHIFT_EXPR
, c
, size_int (p
- 1), 0);
5400 temp
= const_binop (BIT_AND_EXPR
, temp
, size_int (1), 0);
5402 /* We must use a signed type in order to get an arithmetic right shift.
5403 However, we must also avoid introducing accidental overflows, so that
5404 a subsequent call to integer_zerop will work. Hence we must
5405 do the type conversion here. At this point, the constant is either
5406 zero or one, and the conversion to a signed type can never overflow.
5407 We could get an overflow if this conversion is done anywhere else. */
5408 if (TYPE_UNSIGNED (type
))
5409 temp
= fold_convert (signed_type_for (type
), temp
);
5411 temp
= const_binop (LSHIFT_EXPR
, temp
, size_int (modesize
- 1), 0);
5412 temp
= const_binop (RSHIFT_EXPR
, temp
, size_int (modesize
- p
- 1), 0);
5414 temp
= const_binop (BIT_AND_EXPR
, temp
,
5415 fold_convert (TREE_TYPE (c
), mask
), 0);
5416 /* If necessary, convert the type back to match the type of C. */
5417 if (TYPE_UNSIGNED (type
))
5418 temp
= fold_convert (type
, temp
);
5420 return fold_convert (type
, const_binop (BIT_XOR_EXPR
, c
, temp
, 0));
5423 /* Find ways of folding logical expressions of LHS and RHS:
5424 Try to merge two comparisons to the same innermost item.
5425 Look for range tests like "ch >= '0' && ch <= '9'".
5426 Look for combinations of simple terms on machines with expensive branches
5427 and evaluate the RHS unconditionally.
5429 For example, if we have p->a == 2 && p->b == 4 and we can make an
5430 object large enough to span both A and B, we can do this with a comparison
5431 against the object ANDed with the a mask.
5433 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
5434 operations to do this with one comparison.
5436 We check for both normal comparisons and the BIT_AND_EXPRs made this by
5437 function and the one above.
5439 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
5440 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
5442 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
5445 We return the simplified tree or 0 if no optimization is possible. */
5448 fold_truthop (enum tree_code code
, tree truth_type
, tree lhs
, tree rhs
)
5450 /* If this is the "or" of two comparisons, we can do something if
5451 the comparisons are NE_EXPR. If this is the "and", we can do something
5452 if the comparisons are EQ_EXPR. I.e.,
5453 (a->b == 2 && a->c == 4) can become (a->new == NEW).
5455 WANTED_CODE is this operation code. For single bit fields, we can
5456 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
5457 comparison for one-bit fields. */
5459 enum tree_code wanted_code
;
5460 enum tree_code lcode
, rcode
;
5461 tree ll_arg
, lr_arg
, rl_arg
, rr_arg
;
5462 tree ll_inner
, lr_inner
, rl_inner
, rr_inner
;
5463 HOST_WIDE_INT ll_bitsize
, ll_bitpos
, lr_bitsize
, lr_bitpos
;
5464 HOST_WIDE_INT rl_bitsize
, rl_bitpos
, rr_bitsize
, rr_bitpos
;
5465 HOST_WIDE_INT xll_bitpos
, xlr_bitpos
, xrl_bitpos
, xrr_bitpos
;
5466 HOST_WIDE_INT lnbitsize
, lnbitpos
, rnbitsize
, rnbitpos
;
5467 int ll_unsignedp
, lr_unsignedp
, rl_unsignedp
, rr_unsignedp
;
5468 enum machine_mode ll_mode
, lr_mode
, rl_mode
, rr_mode
;
5469 enum machine_mode lnmode
, rnmode
;
5470 tree ll_mask
, lr_mask
, rl_mask
, rr_mask
;
5471 tree ll_and_mask
, lr_and_mask
, rl_and_mask
, rr_and_mask
;
5472 tree l_const
, r_const
;
5473 tree lntype
, rntype
, result
;
5474 int first_bit
, end_bit
;
5476 tree orig_lhs
= lhs
, orig_rhs
= rhs
;
5477 enum tree_code orig_code
= code
;
5479 /* Start by getting the comparison codes. Fail if anything is volatile.
5480 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
5481 it were surrounded with a NE_EXPR. */
5483 if (TREE_SIDE_EFFECTS (lhs
) || TREE_SIDE_EFFECTS (rhs
))
5486 lcode
= TREE_CODE (lhs
);
5487 rcode
= TREE_CODE (rhs
);
5489 if (lcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (lhs
, 1)))
5491 lhs
= build2 (NE_EXPR
, truth_type
, lhs
,
5492 build_int_cst (TREE_TYPE (lhs
), 0));
5496 if (rcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (rhs
, 1)))
5498 rhs
= build2 (NE_EXPR
, truth_type
, rhs
,
5499 build_int_cst (TREE_TYPE (rhs
), 0));
5503 if (TREE_CODE_CLASS (lcode
) != tcc_comparison
5504 || TREE_CODE_CLASS (rcode
) != tcc_comparison
)
5507 ll_arg
= TREE_OPERAND (lhs
, 0);
5508 lr_arg
= TREE_OPERAND (lhs
, 1);
5509 rl_arg
= TREE_OPERAND (rhs
, 0);
5510 rr_arg
= TREE_OPERAND (rhs
, 1);
5512 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
5513 if (simple_operand_p (ll_arg
)
5514 && simple_operand_p (lr_arg
))
5517 if (operand_equal_p (ll_arg
, rl_arg
, 0)
5518 && operand_equal_p (lr_arg
, rr_arg
, 0))
5520 result
= combine_comparisons (code
, lcode
, rcode
,
5521 truth_type
, ll_arg
, lr_arg
);
5525 else if (operand_equal_p (ll_arg
, rr_arg
, 0)
5526 && operand_equal_p (lr_arg
, rl_arg
, 0))
5528 result
= combine_comparisons (code
, lcode
,
5529 swap_tree_comparison (rcode
),
5530 truth_type
, ll_arg
, lr_arg
);
5536 code
= ((code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
)
5537 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
);
5539 /* If the RHS can be evaluated unconditionally and its operands are
5540 simple, it wins to evaluate the RHS unconditionally on machines
5541 with expensive branches. In this case, this isn't a comparison
5542 that can be merged. Avoid doing this if the RHS is a floating-point
5543 comparison since those can trap. */
5545 if (BRANCH_COST
>= 2
5546 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg
))
5547 && simple_operand_p (rl_arg
)
5548 && simple_operand_p (rr_arg
))
5550 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
5551 if (code
== TRUTH_OR_EXPR
5552 && lcode
== NE_EXPR
&& integer_zerop (lr_arg
)
5553 && rcode
== NE_EXPR
&& integer_zerop (rr_arg
)
5554 && TREE_TYPE (ll_arg
) == TREE_TYPE (rl_arg
))
5555 return build2 (NE_EXPR
, truth_type
,
5556 build2 (BIT_IOR_EXPR
, TREE_TYPE (ll_arg
),
5558 build_int_cst (TREE_TYPE (ll_arg
), 0));
5560 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
5561 if (code
== TRUTH_AND_EXPR
5562 && lcode
== EQ_EXPR
&& integer_zerop (lr_arg
)
5563 && rcode
== EQ_EXPR
&& integer_zerop (rr_arg
)
5564 && TREE_TYPE (ll_arg
) == TREE_TYPE (rl_arg
))
5565 return build2 (EQ_EXPR
, truth_type
,
5566 build2 (BIT_IOR_EXPR
, TREE_TYPE (ll_arg
),
5568 build_int_cst (TREE_TYPE (ll_arg
), 0));
5570 if (LOGICAL_OP_NON_SHORT_CIRCUIT
)
5572 if (code
!= orig_code
|| lhs
!= orig_lhs
|| rhs
!= orig_rhs
)
5573 return build2 (code
, truth_type
, lhs
, rhs
);
5578 /* See if the comparisons can be merged. Then get all the parameters for
5581 if ((lcode
!= EQ_EXPR
&& lcode
!= NE_EXPR
)
5582 || (rcode
!= EQ_EXPR
&& rcode
!= NE_EXPR
))
5586 ll_inner
= decode_field_reference (ll_arg
,
5587 &ll_bitsize
, &ll_bitpos
, &ll_mode
,
5588 &ll_unsignedp
, &volatilep
, &ll_mask
,
5590 lr_inner
= decode_field_reference (lr_arg
,
5591 &lr_bitsize
, &lr_bitpos
, &lr_mode
,
5592 &lr_unsignedp
, &volatilep
, &lr_mask
,
5594 rl_inner
= decode_field_reference (rl_arg
,
5595 &rl_bitsize
, &rl_bitpos
, &rl_mode
,
5596 &rl_unsignedp
, &volatilep
, &rl_mask
,
5598 rr_inner
= decode_field_reference (rr_arg
,
5599 &rr_bitsize
, &rr_bitpos
, &rr_mode
,
5600 &rr_unsignedp
, &volatilep
, &rr_mask
,
5603 /* It must be true that the inner operation on the lhs of each
5604 comparison must be the same if we are to be able to do anything.
5605 Then see if we have constants. If not, the same must be true for
5607 if (volatilep
|| ll_inner
== 0 || rl_inner
== 0
5608 || ! operand_equal_p (ll_inner
, rl_inner
, 0))
5611 if (TREE_CODE (lr_arg
) == INTEGER_CST
5612 && TREE_CODE (rr_arg
) == INTEGER_CST
)
5613 l_const
= lr_arg
, r_const
= rr_arg
;
5614 else if (lr_inner
== 0 || rr_inner
== 0
5615 || ! operand_equal_p (lr_inner
, rr_inner
, 0))
5618 l_const
= r_const
= 0;
5620 /* If either comparison code is not correct for our logical operation,
5621 fail. However, we can convert a one-bit comparison against zero into
5622 the opposite comparison against that bit being set in the field. */
5624 wanted_code
= (code
== TRUTH_AND_EXPR
? EQ_EXPR
: NE_EXPR
);
5625 if (lcode
!= wanted_code
)
5627 if (l_const
&& integer_zerop (l_const
) && integer_pow2p (ll_mask
))
5629 /* Make the left operand unsigned, since we are only interested
5630 in the value of one bit. Otherwise we are doing the wrong
5639 /* This is analogous to the code for l_const above. */
5640 if (rcode
!= wanted_code
)
5642 if (r_const
&& integer_zerop (r_const
) && integer_pow2p (rl_mask
))
5651 /* See if we can find a mode that contains both fields being compared on
5652 the left. If we can't, fail. Otherwise, update all constants and masks
5653 to be relative to a field of that size. */
5654 first_bit
= MIN (ll_bitpos
, rl_bitpos
);
5655 end_bit
= MAX (ll_bitpos
+ ll_bitsize
, rl_bitpos
+ rl_bitsize
);
5656 lnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
5657 TYPE_ALIGN (TREE_TYPE (ll_inner
)), word_mode
,
5659 if (lnmode
== VOIDmode
)
5662 lnbitsize
= GET_MODE_BITSIZE (lnmode
);
5663 lnbitpos
= first_bit
& ~ (lnbitsize
- 1);
5664 lntype
= lang_hooks
.types
.type_for_size (lnbitsize
, 1);
5665 xll_bitpos
= ll_bitpos
- lnbitpos
, xrl_bitpos
= rl_bitpos
- lnbitpos
;
5667 if (BYTES_BIG_ENDIAN
)
5669 xll_bitpos
= lnbitsize
- xll_bitpos
- ll_bitsize
;
5670 xrl_bitpos
= lnbitsize
- xrl_bitpos
- rl_bitsize
;
5673 ll_mask
= const_binop (LSHIFT_EXPR
, fold_convert (lntype
, ll_mask
),
5674 size_int (xll_bitpos
), 0);
5675 rl_mask
= const_binop (LSHIFT_EXPR
, fold_convert (lntype
, rl_mask
),
5676 size_int (xrl_bitpos
), 0);
5680 l_const
= fold_convert (lntype
, l_const
);
5681 l_const
= unextend (l_const
, ll_bitsize
, ll_unsignedp
, ll_and_mask
);
5682 l_const
= const_binop (LSHIFT_EXPR
, l_const
, size_int (xll_bitpos
), 0);
5683 if (! integer_zerop (const_binop (BIT_AND_EXPR
, l_const
,
5684 fold_build1 (BIT_NOT_EXPR
,
5688 warning (0, "comparison is always %d", wanted_code
== NE_EXPR
);
5690 return constant_boolean_node (wanted_code
== NE_EXPR
, truth_type
);
5695 r_const
= fold_convert (lntype
, r_const
);
5696 r_const
= unextend (r_const
, rl_bitsize
, rl_unsignedp
, rl_and_mask
);
5697 r_const
= const_binop (LSHIFT_EXPR
, r_const
, size_int (xrl_bitpos
), 0);
5698 if (! integer_zerop (const_binop (BIT_AND_EXPR
, r_const
,
5699 fold_build1 (BIT_NOT_EXPR
,
5703 warning (0, "comparison is always %d", wanted_code
== NE_EXPR
);
5705 return constant_boolean_node (wanted_code
== NE_EXPR
, truth_type
);
5709 /* If the right sides are not constant, do the same for it. Also,
5710 disallow this optimization if a size or signedness mismatch occurs
5711 between the left and right sides. */
5714 if (ll_bitsize
!= lr_bitsize
|| rl_bitsize
!= rr_bitsize
5715 || ll_unsignedp
!= lr_unsignedp
|| rl_unsignedp
!= rr_unsignedp
5716 /* Make sure the two fields on the right
5717 correspond to the left without being swapped. */
5718 || ll_bitpos
- rl_bitpos
!= lr_bitpos
- rr_bitpos
)
5721 first_bit
= MIN (lr_bitpos
, rr_bitpos
);
5722 end_bit
= MAX (lr_bitpos
+ lr_bitsize
, rr_bitpos
+ rr_bitsize
);
5723 rnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
5724 TYPE_ALIGN (TREE_TYPE (lr_inner
)), word_mode
,
5726 if (rnmode
== VOIDmode
)
5729 rnbitsize
= GET_MODE_BITSIZE (rnmode
);
5730 rnbitpos
= first_bit
& ~ (rnbitsize
- 1);
5731 rntype
= lang_hooks
.types
.type_for_size (rnbitsize
, 1);
5732 xlr_bitpos
= lr_bitpos
- rnbitpos
, xrr_bitpos
= rr_bitpos
- rnbitpos
;
5734 if (BYTES_BIG_ENDIAN
)
5736 xlr_bitpos
= rnbitsize
- xlr_bitpos
- lr_bitsize
;
5737 xrr_bitpos
= rnbitsize
- xrr_bitpos
- rr_bitsize
;
5740 lr_mask
= const_binop (LSHIFT_EXPR
, fold_convert (rntype
, lr_mask
),
5741 size_int (xlr_bitpos
), 0);
5742 rr_mask
= const_binop (LSHIFT_EXPR
, fold_convert (rntype
, rr_mask
),
5743 size_int (xrr_bitpos
), 0);
5745 /* Make a mask that corresponds to both fields being compared.
5746 Do this for both items being compared. If the operands are the
5747 same size and the bits being compared are in the same position
5748 then we can do this by masking both and comparing the masked
5750 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
5751 lr_mask
= const_binop (BIT_IOR_EXPR
, lr_mask
, rr_mask
, 0);
5752 if (lnbitsize
== rnbitsize
&& xll_bitpos
== xlr_bitpos
)
5754 lhs
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
5755 ll_unsignedp
|| rl_unsignedp
);
5756 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
5757 lhs
= build2 (BIT_AND_EXPR
, lntype
, lhs
, ll_mask
);
5759 rhs
= make_bit_field_ref (lr_inner
, rntype
, rnbitsize
, rnbitpos
,
5760 lr_unsignedp
|| rr_unsignedp
);
5761 if (! all_ones_mask_p (lr_mask
, rnbitsize
))
5762 rhs
= build2 (BIT_AND_EXPR
, rntype
, rhs
, lr_mask
);
5764 return build2 (wanted_code
, truth_type
, lhs
, rhs
);
5767 /* There is still another way we can do something: If both pairs of
5768 fields being compared are adjacent, we may be able to make a wider
5769 field containing them both.
5771 Note that we still must mask the lhs/rhs expressions. Furthermore,
5772 the mask must be shifted to account for the shift done by
5773 make_bit_field_ref. */
5774 if ((ll_bitsize
+ ll_bitpos
== rl_bitpos
5775 && lr_bitsize
+ lr_bitpos
== rr_bitpos
)
5776 || (ll_bitpos
== rl_bitpos
+ rl_bitsize
5777 && lr_bitpos
== rr_bitpos
+ rr_bitsize
))
5781 lhs
= make_bit_field_ref (ll_inner
, lntype
, ll_bitsize
+ rl_bitsize
,
5782 MIN (ll_bitpos
, rl_bitpos
), ll_unsignedp
);
5783 rhs
= make_bit_field_ref (lr_inner
, rntype
, lr_bitsize
+ rr_bitsize
,
5784 MIN (lr_bitpos
, rr_bitpos
), lr_unsignedp
);
5786 ll_mask
= const_binop (RSHIFT_EXPR
, ll_mask
,
5787 size_int (MIN (xll_bitpos
, xrl_bitpos
)), 0);
5788 lr_mask
= const_binop (RSHIFT_EXPR
, lr_mask
,
5789 size_int (MIN (xlr_bitpos
, xrr_bitpos
)), 0);
5791 /* Convert to the smaller type before masking out unwanted bits. */
5793 if (lntype
!= rntype
)
5795 if (lnbitsize
> rnbitsize
)
5797 lhs
= fold_convert (rntype
, lhs
);
5798 ll_mask
= fold_convert (rntype
, ll_mask
);
5801 else if (lnbitsize
< rnbitsize
)
5803 rhs
= fold_convert (lntype
, rhs
);
5804 lr_mask
= fold_convert (lntype
, lr_mask
);
5809 if (! all_ones_mask_p (ll_mask
, ll_bitsize
+ rl_bitsize
))
5810 lhs
= build2 (BIT_AND_EXPR
, type
, lhs
, ll_mask
);
5812 if (! all_ones_mask_p (lr_mask
, lr_bitsize
+ rr_bitsize
))
5813 rhs
= build2 (BIT_AND_EXPR
, type
, rhs
, lr_mask
);
5815 return build2 (wanted_code
, truth_type
, lhs
, rhs
);
5821 /* Handle the case of comparisons with constants. If there is something in
5822 common between the masks, those bits of the constants must be the same.
5823 If not, the condition is always false. Test for this to avoid generating
5824 incorrect code below. */
5825 result
= const_binop (BIT_AND_EXPR
, ll_mask
, rl_mask
, 0);
5826 if (! integer_zerop (result
)
5827 && simple_cst_equal (const_binop (BIT_AND_EXPR
, result
, l_const
, 0),
5828 const_binop (BIT_AND_EXPR
, result
, r_const
, 0)) != 1)
5830 if (wanted_code
== NE_EXPR
)
5832 warning (0, "%<or%> of unmatched not-equal tests is always 1");
5833 return constant_boolean_node (true, truth_type
);
5837 warning (0, "%<and%> of mutually exclusive equal-tests is always 0");
5838 return constant_boolean_node (false, truth_type
);
5842 /* Construct the expression we will return. First get the component
5843 reference we will make. Unless the mask is all ones the width of
5844 that field, perform the mask operation. Then compare with the
5846 result
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
5847 ll_unsignedp
|| rl_unsignedp
);
5849 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
5850 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
5851 result
= build2 (BIT_AND_EXPR
, lntype
, result
, ll_mask
);
5853 return build2 (wanted_code
, truth_type
, result
,
5854 const_binop (BIT_IOR_EXPR
, l_const
, r_const
, 0));
5857 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
5861 optimize_minmax_comparison (enum tree_code code
, tree type
, tree op0
, tree op1
)
5864 enum tree_code op_code
;
5865 tree comp_const
= op1
;
5867 int consts_equal
, consts_lt
;
5870 STRIP_SIGN_NOPS (arg0
);
5872 op_code
= TREE_CODE (arg0
);
5873 minmax_const
= TREE_OPERAND (arg0
, 1);
5874 consts_equal
= tree_int_cst_equal (minmax_const
, comp_const
);
5875 consts_lt
= tree_int_cst_lt (minmax_const
, comp_const
);
5876 inner
= TREE_OPERAND (arg0
, 0);
5878 /* If something does not permit us to optimize, return the original tree. */
5879 if ((op_code
!= MIN_EXPR
&& op_code
!= MAX_EXPR
)
5880 || TREE_CODE (comp_const
) != INTEGER_CST
5881 || TREE_OVERFLOW (comp_const
)
5882 || TREE_CODE (minmax_const
) != INTEGER_CST
5883 || TREE_OVERFLOW (minmax_const
))
5886 /* Now handle all the various comparison codes. We only handle EQ_EXPR
5887 and GT_EXPR, doing the rest with recursive calls using logical
5891 case NE_EXPR
: case LT_EXPR
: case LE_EXPR
:
5893 tree tem
= optimize_minmax_comparison (invert_tree_comparison (code
, false),
5896 return invert_truthvalue (tem
);
5902 fold_build2 (TRUTH_ORIF_EXPR
, type
,
5903 optimize_minmax_comparison
5904 (EQ_EXPR
, type
, arg0
, comp_const
),
5905 optimize_minmax_comparison
5906 (GT_EXPR
, type
, arg0
, comp_const
));
5909 if (op_code
== MAX_EXPR
&& consts_equal
)
5910 /* MAX (X, 0) == 0 -> X <= 0 */
5911 return fold_build2 (LE_EXPR
, type
, inner
, comp_const
);
5913 else if (op_code
== MAX_EXPR
&& consts_lt
)
5914 /* MAX (X, 0) == 5 -> X == 5 */
5915 return fold_build2 (EQ_EXPR
, type
, inner
, comp_const
);
5917 else if (op_code
== MAX_EXPR
)
5918 /* MAX (X, 0) == -1 -> false */
5919 return omit_one_operand (type
, integer_zero_node
, inner
);
5921 else if (consts_equal
)
5922 /* MIN (X, 0) == 0 -> X >= 0 */
5923 return fold_build2 (GE_EXPR
, type
, inner
, comp_const
);
5926 /* MIN (X, 0) == 5 -> false */
5927 return omit_one_operand (type
, integer_zero_node
, inner
);
5930 /* MIN (X, 0) == -1 -> X == -1 */
5931 return fold_build2 (EQ_EXPR
, type
, inner
, comp_const
);
5934 if (op_code
== MAX_EXPR
&& (consts_equal
|| consts_lt
))
5935 /* MAX (X, 0) > 0 -> X > 0
5936 MAX (X, 0) > 5 -> X > 5 */
5937 return fold_build2 (GT_EXPR
, type
, inner
, comp_const
);
5939 else if (op_code
== MAX_EXPR
)
5940 /* MAX (X, 0) > -1 -> true */
5941 return omit_one_operand (type
, integer_one_node
, inner
);
5943 else if (op_code
== MIN_EXPR
&& (consts_equal
|| consts_lt
))
5944 /* MIN (X, 0) > 0 -> false
5945 MIN (X, 0) > 5 -> false */
5946 return omit_one_operand (type
, integer_zero_node
, inner
);
5949 /* MIN (X, 0) > -1 -> X > -1 */
5950 return fold_build2 (GT_EXPR
, type
, inner
, comp_const
);
5957 /* T is an integer expression that is being multiplied, divided, or taken a
5958 modulus (CODE says which and what kind of divide or modulus) by a
5959 constant C. See if we can eliminate that operation by folding it with
5960 other operations already in T. WIDE_TYPE, if non-null, is a type that
5961 should be used for the computation if wider than our type.
5963 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5964 (X * 2) + (Y * 4). We must, however, be assured that either the original
5965 expression would not overflow or that overflow is undefined for the type
5966 in the language in question.
5968 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5969 the machine has a multiply-accumulate insn or that this is part of an
5970 addressing calculation.
5972 If we return a non-null expression, it is an equivalent form of the
5973 original computation, but need not be in the original type.
5975 We set *STRICT_OVERFLOW_P to true if the return values depends on
5976 signed overflow being undefined. Otherwise we do not change
5977 *STRICT_OVERFLOW_P. */
5980 extract_muldiv (tree t
, tree c
, enum tree_code code
, tree wide_type
,
5981 bool *strict_overflow_p
)
5983 /* To avoid exponential search depth, refuse to allow recursion past
5984 three levels. Beyond that (1) it's highly unlikely that we'll find
5985 something interesting and (2) we've probably processed it before
5986 when we built the inner expression. */
5995 ret
= extract_muldiv_1 (t
, c
, code
, wide_type
, strict_overflow_p
);
6002 extract_muldiv_1 (tree t
, tree c
, enum tree_code code
, tree wide_type
,
6003 bool *strict_overflow_p
)
6005 tree type
= TREE_TYPE (t
);
6006 enum tree_code tcode
= TREE_CODE (t
);
6007 tree ctype
= (wide_type
!= 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type
))
6008 > GET_MODE_SIZE (TYPE_MODE (type
)))
6009 ? wide_type
: type
);
6011 int same_p
= tcode
== code
;
6012 tree op0
= NULL_TREE
, op1
= NULL_TREE
;
6013 bool sub_strict_overflow_p
;
6015 /* Don't deal with constants of zero here; they confuse the code below. */
6016 if (integer_zerop (c
))
6019 if (TREE_CODE_CLASS (tcode
) == tcc_unary
)
6020 op0
= TREE_OPERAND (t
, 0);
6022 if (TREE_CODE_CLASS (tcode
) == tcc_binary
)
6023 op0
= TREE_OPERAND (t
, 0), op1
= TREE_OPERAND (t
, 1);
6025 /* Note that we need not handle conditional operations here since fold
6026 already handles those cases. So just do arithmetic here. */
6030 /* For a constant, we can always simplify if we are a multiply
6031 or (for divide and modulus) if it is a multiple of our constant. */
6032 if (code
== MULT_EXPR
6033 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, t
, c
, 0)))
6034 return const_binop (code
, fold_convert (ctype
, t
),
6035 fold_convert (ctype
, c
), 0);
6038 case CONVERT_EXPR
: case NON_LVALUE_EXPR
: case NOP_EXPR
:
6039 /* If op0 is an expression ... */
6040 if ((COMPARISON_CLASS_P (op0
)
6041 || UNARY_CLASS_P (op0
)
6042 || BINARY_CLASS_P (op0
)
6043 || VL_EXP_CLASS_P (op0
)
6044 || EXPRESSION_CLASS_P (op0
))
6045 /* ... and is unsigned, and its type is smaller than ctype,
6046 then we cannot pass through as widening. */
6047 && ((TYPE_UNSIGNED (TREE_TYPE (op0
))
6048 && ! (TREE_CODE (TREE_TYPE (op0
)) == INTEGER_TYPE
6049 && TYPE_IS_SIZETYPE (TREE_TYPE (op0
)))
6050 && (GET_MODE_SIZE (TYPE_MODE (ctype
))
6051 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
)))))
6052 /* ... or this is a truncation (t is narrower than op0),
6053 then we cannot pass through this narrowing. */
6054 || (GET_MODE_SIZE (TYPE_MODE (type
))
6055 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
))))
6056 /* ... or signedness changes for division or modulus,
6057 then we cannot pass through this conversion. */
6058 || (code
!= MULT_EXPR
6059 && (TYPE_UNSIGNED (ctype
)
6060 != TYPE_UNSIGNED (TREE_TYPE (op0
))))))
6063 /* Pass the constant down and see if we can make a simplification. If
6064 we can, replace this expression with the inner simplification for
6065 possible later conversion to our or some other type. */
6066 if ((t2
= fold_convert (TREE_TYPE (op0
), c
)) != 0
6067 && TREE_CODE (t2
) == INTEGER_CST
6068 && !TREE_OVERFLOW (t2
)
6069 && (0 != (t1
= extract_muldiv (op0
, t2
, code
,
6071 ? ctype
: NULL_TREE
,
6072 strict_overflow_p
))))
6077 /* If widening the type changes it from signed to unsigned, then we
6078 must avoid building ABS_EXPR itself as unsigned. */
6079 if (TYPE_UNSIGNED (ctype
) && !TYPE_UNSIGNED (type
))
6081 tree cstype
= (*signed_type_for
) (ctype
);
6082 if ((t1
= extract_muldiv (op0
, c
, code
, cstype
, strict_overflow_p
))
6085 t1
= fold_build1 (tcode
, cstype
, fold_convert (cstype
, t1
));
6086 return fold_convert (ctype
, t1
);
6092 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
, strict_overflow_p
))
6094 return fold_build1 (tcode
, ctype
, fold_convert (ctype
, t1
));
6097 case MIN_EXPR
: case MAX_EXPR
:
6098 /* If widening the type changes the signedness, then we can't perform
6099 this optimization as that changes the result. */
6100 if (TYPE_UNSIGNED (ctype
) != TYPE_UNSIGNED (type
))
6103 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
6104 sub_strict_overflow_p
= false;
6105 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
,
6106 &sub_strict_overflow_p
)) != 0
6107 && (t2
= extract_muldiv (op1
, c
, code
, wide_type
,
6108 &sub_strict_overflow_p
)) != 0)
6110 if (tree_int_cst_sgn (c
) < 0)
6111 tcode
= (tcode
== MIN_EXPR
? MAX_EXPR
: MIN_EXPR
);
6112 if (sub_strict_overflow_p
)
6113 *strict_overflow_p
= true;
6114 return fold_build2 (tcode
, ctype
, fold_convert (ctype
, t1
),
6115 fold_convert (ctype
, t2
));
6119 case LSHIFT_EXPR
: case RSHIFT_EXPR
:
6120 /* If the second operand is constant, this is a multiplication
6121 or floor division, by a power of two, so we can treat it that
6122 way unless the multiplier or divisor overflows. Signed
6123 left-shift overflow is implementation-defined rather than
6124 undefined in C90, so do not convert signed left shift into
6126 if (TREE_CODE (op1
) == INTEGER_CST
6127 && (tcode
== RSHIFT_EXPR
|| TYPE_UNSIGNED (TREE_TYPE (op0
)))
6128 /* const_binop may not detect overflow correctly,
6129 so check for it explicitly here. */
6130 && TYPE_PRECISION (TREE_TYPE (size_one_node
)) > TREE_INT_CST_LOW (op1
)
6131 && TREE_INT_CST_HIGH (op1
) == 0
6132 && 0 != (t1
= fold_convert (ctype
,
6133 const_binop (LSHIFT_EXPR
,
6136 && !TREE_OVERFLOW (t1
))
6137 return extract_muldiv (build2 (tcode
== LSHIFT_EXPR
6138 ? MULT_EXPR
: FLOOR_DIV_EXPR
,
6139 ctype
, fold_convert (ctype
, op0
), t1
),
6140 c
, code
, wide_type
, strict_overflow_p
);
6143 case PLUS_EXPR
: case MINUS_EXPR
:
6144 /* See if we can eliminate the operation on both sides. If we can, we
6145 can return a new PLUS or MINUS. If we can't, the only remaining
6146 cases where we can do anything are if the second operand is a
6148 sub_strict_overflow_p
= false;
6149 t1
= extract_muldiv (op0
, c
, code
, wide_type
, &sub_strict_overflow_p
);
6150 t2
= extract_muldiv (op1
, c
, code
, wide_type
, &sub_strict_overflow_p
);
6151 if (t1
!= 0 && t2
!= 0
6152 && (code
== MULT_EXPR
6153 /* If not multiplication, we can only do this if both operands
6154 are divisible by c. */
6155 || (multiple_of_p (ctype
, op0
, c
)
6156 && multiple_of_p (ctype
, op1
, c
))))
6158 if (sub_strict_overflow_p
)
6159 *strict_overflow_p
= true;
6160 return fold_build2 (tcode
, ctype
, fold_convert (ctype
, t1
),
6161 fold_convert (ctype
, t2
));
6164 /* If this was a subtraction, negate OP1 and set it to be an addition.
6165 This simplifies the logic below. */
6166 if (tcode
== MINUS_EXPR
)
6167 tcode
= PLUS_EXPR
, op1
= negate_expr (op1
);
6169 if (TREE_CODE (op1
) != INTEGER_CST
)
6172 /* If either OP1 or C are negative, this optimization is not safe for
6173 some of the division and remainder types while for others we need
6174 to change the code. */
6175 if (tree_int_cst_sgn (op1
) < 0 || tree_int_cst_sgn (c
) < 0)
6177 if (code
== CEIL_DIV_EXPR
)
6178 code
= FLOOR_DIV_EXPR
;
6179 else if (code
== FLOOR_DIV_EXPR
)
6180 code
= CEIL_DIV_EXPR
;
6181 else if (code
!= MULT_EXPR
6182 && code
!= CEIL_MOD_EXPR
&& code
!= FLOOR_MOD_EXPR
)
6186 /* If it's a multiply or a division/modulus operation of a multiple
6187 of our constant, do the operation and verify it doesn't overflow. */
6188 if (code
== MULT_EXPR
6189 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
6191 op1
= const_binop (code
, fold_convert (ctype
, op1
),
6192 fold_convert (ctype
, c
), 0);
6193 /* We allow the constant to overflow with wrapping semantics. */
6195 || (TREE_OVERFLOW (op1
) && !TYPE_OVERFLOW_WRAPS (ctype
)))
6201 /* If we have an unsigned type is not a sizetype, we cannot widen
6202 the operation since it will change the result if the original
6203 computation overflowed. */
6204 if (TYPE_UNSIGNED (ctype
)
6205 && ! (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
))
6209 /* If we were able to eliminate our operation from the first side,
6210 apply our operation to the second side and reform the PLUS. */
6211 if (t1
!= 0 && (TREE_CODE (t1
) != code
|| code
== MULT_EXPR
))
6212 return fold_build2 (tcode
, ctype
, fold_convert (ctype
, t1
), op1
);
6214 /* The last case is if we are a multiply. In that case, we can
6215 apply the distributive law to commute the multiply and addition
6216 if the multiplication of the constants doesn't overflow. */
6217 if (code
== MULT_EXPR
)
6218 return fold_build2 (tcode
, ctype
,
6219 fold_build2 (code
, ctype
,
6220 fold_convert (ctype
, op0
),
6221 fold_convert (ctype
, c
)),
6227 /* We have a special case here if we are doing something like
6228 (C * 8) % 4 since we know that's zero. */
6229 if ((code
== TRUNC_MOD_EXPR
|| code
== CEIL_MOD_EXPR
6230 || code
== FLOOR_MOD_EXPR
|| code
== ROUND_MOD_EXPR
)
6231 && TREE_CODE (TREE_OPERAND (t
, 1)) == INTEGER_CST
6232 && integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
6233 return omit_one_operand (type
, integer_zero_node
, op0
);
6235 /* ... fall through ... */
6237 case TRUNC_DIV_EXPR
: case CEIL_DIV_EXPR
: case FLOOR_DIV_EXPR
:
6238 case ROUND_DIV_EXPR
: case EXACT_DIV_EXPR
:
6239 /* If we can extract our operation from the LHS, do so and return a
6240 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
6241 do something only if the second operand is a constant. */
6243 && (t1
= extract_muldiv (op0
, c
, code
, wide_type
,
6244 strict_overflow_p
)) != 0)
6245 return fold_build2 (tcode
, ctype
, fold_convert (ctype
, t1
),
6246 fold_convert (ctype
, op1
));
6247 else if (tcode
== MULT_EXPR
&& code
== MULT_EXPR
6248 && (t1
= extract_muldiv (op1
, c
, code
, wide_type
,
6249 strict_overflow_p
)) != 0)
6250 return fold_build2 (tcode
, ctype
, fold_convert (ctype
, op0
),
6251 fold_convert (ctype
, t1
));
6252 else if (TREE_CODE (op1
) != INTEGER_CST
)
6255 /* If these are the same operation types, we can associate them
6256 assuming no overflow. */
6258 && 0 != (t1
= const_binop (MULT_EXPR
, fold_convert (ctype
, op1
),
6259 fold_convert (ctype
, c
), 0))
6260 && !TREE_OVERFLOW (t1
))
6261 return fold_build2 (tcode
, ctype
, fold_convert (ctype
, op0
), t1
);
6263 /* If these operations "cancel" each other, we have the main
6264 optimizations of this pass, which occur when either constant is a
6265 multiple of the other, in which case we replace this with either an
6266 operation or CODE or TCODE.
6268 If we have an unsigned type that is not a sizetype, we cannot do
6269 this since it will change the result if the original computation
6271 if ((TYPE_OVERFLOW_UNDEFINED (ctype
)
6272 || (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
)))
6273 && ((code
== MULT_EXPR
&& tcode
== EXACT_DIV_EXPR
)
6274 || (tcode
== MULT_EXPR
6275 && code
!= TRUNC_MOD_EXPR
&& code
!= CEIL_MOD_EXPR
6276 && code
!= FLOOR_MOD_EXPR
&& code
!= ROUND_MOD_EXPR
)))
6278 if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
6280 if (TYPE_OVERFLOW_UNDEFINED (ctype
))
6281 *strict_overflow_p
= true;
6282 return fold_build2 (tcode
, ctype
, fold_convert (ctype
, op0
),
6283 fold_convert (ctype
,
6284 const_binop (TRUNC_DIV_EXPR
,
6287 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, c
, op1
, 0)))
6289 if (TYPE_OVERFLOW_UNDEFINED (ctype
))
6290 *strict_overflow_p
= true;
6291 return fold_build2 (code
, ctype
, fold_convert (ctype
, op0
),
6292 fold_convert (ctype
,
6293 const_binop (TRUNC_DIV_EXPR
,
6306 /* Return a node which has the indicated constant VALUE (either 0 or
6307 1), and is of the indicated TYPE. */
6310 constant_boolean_node (int value
, tree type
)
6312 if (type
== integer_type_node
)
6313 return value
? integer_one_node
: integer_zero_node
;
6314 else if (type
== boolean_type_node
)
6315 return value
? boolean_true_node
: boolean_false_node
;
6317 return build_int_cst (type
, value
);
6321 /* Return true if expr looks like an ARRAY_REF and set base and
6322 offset to the appropriate trees. If there is no offset,
6323 offset is set to NULL_TREE. Base will be canonicalized to
6324 something you can get the element type from using
6325 TREE_TYPE (TREE_TYPE (base)). Offset will be the offset
6326 in bytes to the base in sizetype. */
6329 extract_array_ref (tree expr
, tree
*base
, tree
*offset
)
6331 /* One canonical form is a PLUS_EXPR with the first
6332 argument being an ADDR_EXPR with a possible NOP_EXPR
6334 if (TREE_CODE (expr
) == POINTER_PLUS_EXPR
)
6336 tree op0
= TREE_OPERAND (expr
, 0);
6337 tree inner_base
, dummy1
;
6338 /* Strip NOP_EXPRs here because the C frontends and/or
6339 folders present us (int *)&x.a p+ 4 possibly. */
6341 if (extract_array_ref (op0
, &inner_base
, &dummy1
))
6344 *offset
= fold_convert (sizetype
, TREE_OPERAND (expr
, 1));
6345 if (dummy1
!= NULL_TREE
)
6346 *offset
= fold_build2 (PLUS_EXPR
, sizetype
,
6351 /* Other canonical form is an ADDR_EXPR of an ARRAY_REF,
6352 which we transform into an ADDR_EXPR with appropriate
6353 offset. For other arguments to the ADDR_EXPR we assume
6354 zero offset and as such do not care about the ADDR_EXPR
6355 type and strip possible nops from it. */
6356 else if (TREE_CODE (expr
) == ADDR_EXPR
)
6358 tree op0
= TREE_OPERAND (expr
, 0);
6359 if (TREE_CODE (op0
) == ARRAY_REF
)
6361 tree idx
= TREE_OPERAND (op0
, 1);
6362 *base
= TREE_OPERAND (op0
, 0);
6363 *offset
= fold_build2 (MULT_EXPR
, TREE_TYPE (idx
), idx
,
6364 array_ref_element_size (op0
));
6365 *offset
= fold_convert (sizetype
, *offset
);
6369 /* Handle array-to-pointer decay as &a. */
6370 if (TREE_CODE (TREE_TYPE (op0
)) == ARRAY_TYPE
)
6371 *base
= TREE_OPERAND (expr
, 0);
6374 *offset
= NULL_TREE
;
6378 /* The next canonical form is a VAR_DECL with POINTER_TYPE. */
6379 else if (SSA_VAR_P (expr
)
6380 && TREE_CODE (TREE_TYPE (expr
)) == POINTER_TYPE
)
6383 *offset
= NULL_TREE
;
6391 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
6392 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
6393 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
6394 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
6395 COND is the first argument to CODE; otherwise (as in the example
6396 given here), it is the second argument. TYPE is the type of the
6397 original expression. Return NULL_TREE if no simplification is
6401 fold_binary_op_with_conditional_arg (enum tree_code code
,
6402 tree type
, tree op0
, tree op1
,
6403 tree cond
, tree arg
, int cond_first_p
)
6405 tree cond_type
= cond_first_p
? TREE_TYPE (op0
) : TREE_TYPE (op1
);
6406 tree arg_type
= cond_first_p
? TREE_TYPE (op1
) : TREE_TYPE (op0
);
6407 tree test
, true_value
, false_value
;
6408 tree lhs
= NULL_TREE
;
6409 tree rhs
= NULL_TREE
;
6411 /* This transformation is only worthwhile if we don't have to wrap
6412 arg in a SAVE_EXPR, and the operation can be simplified on at least
6413 one of the branches once its pushed inside the COND_EXPR. */
6414 if (!TREE_CONSTANT (arg
))
6417 if (TREE_CODE (cond
) == COND_EXPR
)
6419 test
= TREE_OPERAND (cond
, 0);
6420 true_value
= TREE_OPERAND (cond
, 1);
6421 false_value
= TREE_OPERAND (cond
, 2);
6422 /* If this operand throws an expression, then it does not make
6423 sense to try to perform a logical or arithmetic operation
6425 if (VOID_TYPE_P (TREE_TYPE (true_value
)))
6427 if (VOID_TYPE_P (TREE_TYPE (false_value
)))
6432 tree testtype
= TREE_TYPE (cond
);
6434 true_value
= constant_boolean_node (true, testtype
);
6435 false_value
= constant_boolean_node (false, testtype
);
6438 arg
= fold_convert (arg_type
, arg
);
6441 true_value
= fold_convert (cond_type
, true_value
);
6443 lhs
= fold_build2 (code
, type
, true_value
, arg
);
6445 lhs
= fold_build2 (code
, type
, arg
, true_value
);
6449 false_value
= fold_convert (cond_type
, false_value
);
6451 rhs
= fold_build2 (code
, type
, false_value
, arg
);
6453 rhs
= fold_build2 (code
, type
, arg
, false_value
);
6456 test
= fold_build3 (COND_EXPR
, type
, test
, lhs
, rhs
);
6457 return fold_convert (type
, test
);
6461 /* Subroutine of fold() that checks for the addition of +/- 0.0.
6463 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
6464 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
6465 ADDEND is the same as X.
6467 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
6468 and finite. The problematic cases are when X is zero, and its mode
6469 has signed zeros. In the case of rounding towards -infinity,
6470 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
6471 modes, X + 0 is not the same as X because -0 + 0 is 0. */
6474 fold_real_zero_addition_p (tree type
, tree addend
, int negate
)
6476 if (!real_zerop (addend
))
6479 /* Don't allow the fold with -fsignaling-nans. */
6480 if (HONOR_SNANS (TYPE_MODE (type
)))
6483 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
6484 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type
)))
6487 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
6488 if (TREE_CODE (addend
) == REAL_CST
6489 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend
)))
6492 /* The mode has signed zeros, and we have to honor their sign.
6493 In this situation, there is only one case we can return true for.
6494 X - 0 is the same as X unless rounding towards -infinity is
6496 return negate
&& !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type
));
6499 /* Subroutine of fold() that checks comparisons of built-in math
6500 functions against real constants.
6502 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
6503 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
6504 is the type of the result and ARG0 and ARG1 are the operands of the
6505 comparison. ARG1 must be a TREE_REAL_CST.
6507 The function returns the constant folded tree if a simplification
6508 can be made, and NULL_TREE otherwise. */
6511 fold_mathfn_compare (enum built_in_function fcode
, enum tree_code code
,
6512 tree type
, tree arg0
, tree arg1
)
6516 if (BUILTIN_SQRT_P (fcode
))
6518 tree arg
= CALL_EXPR_ARG (arg0
, 0);
6519 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (arg0
));
6521 c
= TREE_REAL_CST (arg1
);
6522 if (REAL_VALUE_NEGATIVE (c
))
6524 /* sqrt(x) < y is always false, if y is negative. */
6525 if (code
== EQ_EXPR
|| code
== LT_EXPR
|| code
== LE_EXPR
)
6526 return omit_one_operand (type
, integer_zero_node
, arg
);
6528 /* sqrt(x) > y is always true, if y is negative and we
6529 don't care about NaNs, i.e. negative values of x. */
6530 if (code
== NE_EXPR
|| !HONOR_NANS (mode
))
6531 return omit_one_operand (type
, integer_one_node
, arg
);
6533 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
6534 return fold_build2 (GE_EXPR
, type
, arg
,
6535 build_real (TREE_TYPE (arg
), dconst0
));
6537 else if (code
== GT_EXPR
|| code
== GE_EXPR
)
6541 REAL_ARITHMETIC (c2
, MULT_EXPR
, c
, c
);
6542 real_convert (&c2
, mode
, &c2
);
6544 if (REAL_VALUE_ISINF (c2
))
6546 /* sqrt(x) > y is x == +Inf, when y is very large. */
6547 if (HONOR_INFINITIES (mode
))
6548 return fold_build2 (EQ_EXPR
, type
, arg
,
6549 build_real (TREE_TYPE (arg
), c2
));
6551 /* sqrt(x) > y is always false, when y is very large
6552 and we don't care about infinities. */
6553 return omit_one_operand (type
, integer_zero_node
, arg
);
6556 /* sqrt(x) > c is the same as x > c*c. */
6557 return fold_build2 (code
, type
, arg
,
6558 build_real (TREE_TYPE (arg
), c2
));
6560 else if (code
== LT_EXPR
|| code
== LE_EXPR
)
6564 REAL_ARITHMETIC (c2
, MULT_EXPR
, c
, c
);
6565 real_convert (&c2
, mode
, &c2
);
6567 if (REAL_VALUE_ISINF (c2
))
6569 /* sqrt(x) < y is always true, when y is a very large
6570 value and we don't care about NaNs or Infinities. */
6571 if (! HONOR_NANS (mode
) && ! HONOR_INFINITIES (mode
))
6572 return omit_one_operand (type
, integer_one_node
, arg
);
6574 /* sqrt(x) < y is x != +Inf when y is very large and we
6575 don't care about NaNs. */
6576 if (! HONOR_NANS (mode
))
6577 return fold_build2 (NE_EXPR
, type
, arg
,
6578 build_real (TREE_TYPE (arg
), c2
));
6580 /* sqrt(x) < y is x >= 0 when y is very large and we
6581 don't care about Infinities. */
6582 if (! HONOR_INFINITIES (mode
))
6583 return fold_build2 (GE_EXPR
, type
, arg
,
6584 build_real (TREE_TYPE (arg
), dconst0
));
6586 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
6587 if (lang_hooks
.decls
.global_bindings_p () != 0
6588 || CONTAINS_PLACEHOLDER_P (arg
))
6591 arg
= save_expr (arg
);
6592 return fold_build2 (TRUTH_ANDIF_EXPR
, type
,
6593 fold_build2 (GE_EXPR
, type
, arg
,
6594 build_real (TREE_TYPE (arg
),
6596 fold_build2 (NE_EXPR
, type
, arg
,
6597 build_real (TREE_TYPE (arg
),
6601 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
6602 if (! HONOR_NANS (mode
))
6603 return fold_build2 (code
, type
, arg
,
6604 build_real (TREE_TYPE (arg
), c2
));
6606 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
6607 if (lang_hooks
.decls
.global_bindings_p () == 0
6608 && ! CONTAINS_PLACEHOLDER_P (arg
))
6610 arg
= save_expr (arg
);
6611 return fold_build2 (TRUTH_ANDIF_EXPR
, type
,
6612 fold_build2 (GE_EXPR
, type
, arg
,
6613 build_real (TREE_TYPE (arg
),
6615 fold_build2 (code
, type
, arg
,
6616 build_real (TREE_TYPE (arg
),
6625 /* Subroutine of fold() that optimizes comparisons against Infinities,
6626 either +Inf or -Inf.
6628 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6629 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6630 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6632 The function returns the constant folded tree if a simplification
6633 can be made, and NULL_TREE otherwise. */
6636 fold_inf_compare (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
6638 enum machine_mode mode
;
6639 REAL_VALUE_TYPE max
;
6643 mode
= TYPE_MODE (TREE_TYPE (arg0
));
6645 /* For negative infinity swap the sense of the comparison. */
6646 neg
= REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1
));
6648 code
= swap_tree_comparison (code
);
6653 /* x > +Inf is always false, if with ignore sNANs. */
6654 if (HONOR_SNANS (mode
))
6656 return omit_one_operand (type
, integer_zero_node
, arg0
);
6659 /* x <= +Inf is always true, if we don't case about NaNs. */
6660 if (! HONOR_NANS (mode
))
6661 return omit_one_operand (type
, integer_one_node
, arg0
);
6663 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
6664 if (lang_hooks
.decls
.global_bindings_p () == 0
6665 && ! CONTAINS_PLACEHOLDER_P (arg0
))
6667 arg0
= save_expr (arg0
);
6668 return fold_build2 (EQ_EXPR
, type
, arg0
, arg0
);
6674 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
6675 real_maxval (&max
, neg
, mode
);
6676 return fold_build2 (neg
? LT_EXPR
: GT_EXPR
, type
,
6677 arg0
, build_real (TREE_TYPE (arg0
), max
));
6680 /* x < +Inf is always equal to x <= DBL_MAX. */
6681 real_maxval (&max
, neg
, mode
);
6682 return fold_build2 (neg
? GE_EXPR
: LE_EXPR
, type
,
6683 arg0
, build_real (TREE_TYPE (arg0
), max
));
6686 /* x != +Inf is always equal to !(x > DBL_MAX). */
6687 real_maxval (&max
, neg
, mode
);
6688 if (! HONOR_NANS (mode
))
6689 return fold_build2 (neg
? GE_EXPR
: LE_EXPR
, type
,
6690 arg0
, build_real (TREE_TYPE (arg0
), max
));
6692 temp
= fold_build2 (neg
? LT_EXPR
: GT_EXPR
, type
,
6693 arg0
, build_real (TREE_TYPE (arg0
), max
));
6694 return fold_build1 (TRUTH_NOT_EXPR
, type
, temp
);
6703 /* Subroutine of fold() that optimizes comparisons of a division by
6704 a nonzero integer constant against an integer constant, i.e.
6707 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6708 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6709 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6711 The function returns the constant folded tree if a simplification
6712 can be made, and NULL_TREE otherwise. */
6715 fold_div_compare (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
6717 tree prod
, tmp
, hi
, lo
;
6718 tree arg00
= TREE_OPERAND (arg0
, 0);
6719 tree arg01
= TREE_OPERAND (arg0
, 1);
6720 unsigned HOST_WIDE_INT lpart
;
6721 HOST_WIDE_INT hpart
;
6722 bool unsigned_p
= TYPE_UNSIGNED (TREE_TYPE (arg0
));
6726 /* We have to do this the hard way to detect unsigned overflow.
6727 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
6728 overflow
= mul_double_with_sign (TREE_INT_CST_LOW (arg01
),
6729 TREE_INT_CST_HIGH (arg01
),
6730 TREE_INT_CST_LOW (arg1
),
6731 TREE_INT_CST_HIGH (arg1
),
6732 &lpart
, &hpart
, unsigned_p
);
6733 prod
= force_fit_type_double (TREE_TYPE (arg00
), lpart
, hpart
,
6735 neg_overflow
= false;
6739 tmp
= int_const_binop (MINUS_EXPR
, arg01
,
6740 build_int_cst (TREE_TYPE (arg01
), 1), 0);
6743 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
6744 overflow
= add_double_with_sign (TREE_INT_CST_LOW (prod
),
6745 TREE_INT_CST_HIGH (prod
),
6746 TREE_INT_CST_LOW (tmp
),
6747 TREE_INT_CST_HIGH (tmp
),
6748 &lpart
, &hpart
, unsigned_p
);
6749 hi
= force_fit_type_double (TREE_TYPE (arg00
), lpart
, hpart
,
6750 -1, overflow
| TREE_OVERFLOW (prod
));
6752 else if (tree_int_cst_sgn (arg01
) >= 0)
6754 tmp
= int_const_binop (MINUS_EXPR
, arg01
,
6755 build_int_cst (TREE_TYPE (arg01
), 1), 0);
6756 switch (tree_int_cst_sgn (arg1
))
6759 neg_overflow
= true;
6760 lo
= int_const_binop (MINUS_EXPR
, prod
, tmp
, 0);
6765 lo
= fold_negate_const (tmp
, TREE_TYPE (arg0
));
6770 hi
= int_const_binop (PLUS_EXPR
, prod
, tmp
, 0);
6780 /* A negative divisor reverses the relational operators. */
6781 code
= swap_tree_comparison (code
);
6783 tmp
= int_const_binop (PLUS_EXPR
, arg01
,
6784 build_int_cst (TREE_TYPE (arg01
), 1), 0);
6785 switch (tree_int_cst_sgn (arg1
))
6788 hi
= int_const_binop (MINUS_EXPR
, prod
, tmp
, 0);
6793 hi
= fold_negate_const (tmp
, TREE_TYPE (arg0
));
6798 neg_overflow
= true;
6799 lo
= int_const_binop (PLUS_EXPR
, prod
, tmp
, 0);
6811 if (TREE_OVERFLOW (lo
) && TREE_OVERFLOW (hi
))
6812 return omit_one_operand (type
, integer_zero_node
, arg00
);
6813 if (TREE_OVERFLOW (hi
))
6814 return fold_build2 (GE_EXPR
, type
, arg00
, lo
);
6815 if (TREE_OVERFLOW (lo
))
6816 return fold_build2 (LE_EXPR
, type
, arg00
, hi
);
6817 return build_range_check (type
, arg00
, 1, lo
, hi
);
6820 if (TREE_OVERFLOW (lo
) && TREE_OVERFLOW (hi
))
6821 return omit_one_operand (type
, integer_one_node
, arg00
);
6822 if (TREE_OVERFLOW (hi
))
6823 return fold_build2 (LT_EXPR
, type
, arg00
, lo
);
6824 if (TREE_OVERFLOW (lo
))
6825 return fold_build2 (GT_EXPR
, type
, arg00
, hi
);
6826 return build_range_check (type
, arg00
, 0, lo
, hi
);
6829 if (TREE_OVERFLOW (lo
))
6831 tmp
= neg_overflow
? integer_zero_node
: integer_one_node
;
6832 return omit_one_operand (type
, tmp
, arg00
);
6834 return fold_build2 (LT_EXPR
, type
, arg00
, lo
);
6837 if (TREE_OVERFLOW (hi
))
6839 tmp
= neg_overflow
? integer_zero_node
: integer_one_node
;
6840 return omit_one_operand (type
, tmp
, arg00
);
6842 return fold_build2 (LE_EXPR
, type
, arg00
, hi
);
6845 if (TREE_OVERFLOW (hi
))
6847 tmp
= neg_overflow
? integer_one_node
: integer_zero_node
;
6848 return omit_one_operand (type
, tmp
, arg00
);
6850 return fold_build2 (GT_EXPR
, type
, arg00
, hi
);
6853 if (TREE_OVERFLOW (lo
))
6855 tmp
= neg_overflow
? integer_one_node
: integer_zero_node
;
6856 return omit_one_operand (type
, tmp
, arg00
);
6858 return fold_build2 (GE_EXPR
, type
, arg00
, lo
);
6868 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6869 equality/inequality test, then return a simplified form of the test
6870 using a sign testing. Otherwise return NULL. TYPE is the desired
6874 fold_single_bit_test_into_sign_test (enum tree_code code
, tree arg0
, tree arg1
,
6877 /* If this is testing a single bit, we can optimize the test. */
6878 if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
6879 && TREE_CODE (arg0
) == BIT_AND_EXPR
&& integer_zerop (arg1
)
6880 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
6882 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6883 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6884 tree arg00
= sign_bit_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg0
, 1));
6886 if (arg00
!= NULL_TREE
6887 /* This is only a win if casting to a signed type is cheap,
6888 i.e. when arg00's type is not a partial mode. */
6889 && TYPE_PRECISION (TREE_TYPE (arg00
))
6890 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00
))))
6892 tree stype
= signed_type_for (TREE_TYPE (arg00
));
6893 return fold_build2 (code
== EQ_EXPR
? GE_EXPR
: LT_EXPR
,
6894 result_type
, fold_convert (stype
, arg00
),
6895 build_int_cst (stype
, 0));
6902 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6903 equality/inequality test, then return a simplified form of
6904 the test using shifts and logical operations. Otherwise return
6905 NULL. TYPE is the desired result type. */
6908 fold_single_bit_test (enum tree_code code
, tree arg0
, tree arg1
,
6911 /* If this is testing a single bit, we can optimize the test. */
6912 if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
6913 && TREE_CODE (arg0
) == BIT_AND_EXPR
&& integer_zerop (arg1
)
6914 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
6916 tree inner
= TREE_OPERAND (arg0
, 0);
6917 tree type
= TREE_TYPE (arg0
);
6918 int bitnum
= tree_log2 (TREE_OPERAND (arg0
, 1));
6919 enum machine_mode operand_mode
= TYPE_MODE (type
);
6921 tree signed_type
, unsigned_type
, intermediate_type
;
6924 /* First, see if we can fold the single bit test into a sign-bit
6926 tem
= fold_single_bit_test_into_sign_test (code
, arg0
, arg1
,
6931 /* Otherwise we have (A & C) != 0 where C is a single bit,
6932 convert that into ((A >> C2) & 1). Where C2 = log2(C).
6933 Similarly for (A & C) == 0. */
6935 /* If INNER is a right shift of a constant and it plus BITNUM does
6936 not overflow, adjust BITNUM and INNER. */
6937 if (TREE_CODE (inner
) == RSHIFT_EXPR
6938 && TREE_CODE (TREE_OPERAND (inner
, 1)) == INTEGER_CST
6939 && TREE_INT_CST_HIGH (TREE_OPERAND (inner
, 1)) == 0
6940 && bitnum
< TYPE_PRECISION (type
)
6941 && 0 > compare_tree_int (TREE_OPERAND (inner
, 1),
6942 bitnum
- TYPE_PRECISION (type
)))
6944 bitnum
+= TREE_INT_CST_LOW (TREE_OPERAND (inner
, 1));
6945 inner
= TREE_OPERAND (inner
, 0);
6948 /* If we are going to be able to omit the AND below, we must do our
6949 operations as unsigned. If we must use the AND, we have a choice.
6950 Normally unsigned is faster, but for some machines signed is. */
6951 #ifdef LOAD_EXTEND_OP
6952 ops_unsigned
= (LOAD_EXTEND_OP (operand_mode
) == SIGN_EXTEND
6953 && !flag_syntax_only
) ? 0 : 1;
6958 signed_type
= lang_hooks
.types
.type_for_mode (operand_mode
, 0);
6959 unsigned_type
= lang_hooks
.types
.type_for_mode (operand_mode
, 1);
6960 intermediate_type
= ops_unsigned
? unsigned_type
: signed_type
;
6961 inner
= fold_convert (intermediate_type
, inner
);
6964 inner
= build2 (RSHIFT_EXPR
, intermediate_type
,
6965 inner
, size_int (bitnum
));
6967 one
= build_int_cst (intermediate_type
, 1);
6969 if (code
== EQ_EXPR
)
6970 inner
= fold_build2 (BIT_XOR_EXPR
, intermediate_type
, inner
, one
);
6972 /* Put the AND last so it can combine with more things. */
6973 inner
= build2 (BIT_AND_EXPR
, intermediate_type
, inner
, one
);
6975 /* Make sure to return the proper type. */
6976 inner
= fold_convert (result_type
, inner
);
6983 /* Check whether we are allowed to reorder operands arg0 and arg1,
6984 such that the evaluation of arg1 occurs before arg0. */
6987 reorder_operands_p (tree arg0
, tree arg1
)
6989 if (! flag_evaluation_order
)
6991 if (TREE_CONSTANT (arg0
) || TREE_CONSTANT (arg1
))
6993 return ! TREE_SIDE_EFFECTS (arg0
)
6994 && ! TREE_SIDE_EFFECTS (arg1
);
6997 /* Test whether it is preferable two swap two operands, ARG0 and
6998 ARG1, for example because ARG0 is an integer constant and ARG1
6999 isn't. If REORDER is true, only recommend swapping if we can
7000 evaluate the operands in reverse order. */
7003 tree_swap_operands_p (const_tree arg0
, const_tree arg1
, bool reorder
)
7005 STRIP_SIGN_NOPS (arg0
);
7006 STRIP_SIGN_NOPS (arg1
);
7008 if (TREE_CODE (arg1
) == INTEGER_CST
)
7010 if (TREE_CODE (arg0
) == INTEGER_CST
)
7013 if (TREE_CODE (arg1
) == REAL_CST
)
7015 if (TREE_CODE (arg0
) == REAL_CST
)
7018 if (TREE_CODE (arg1
) == FIXED_CST
)
7020 if (TREE_CODE (arg0
) == FIXED_CST
)
7023 if (TREE_CODE (arg1
) == COMPLEX_CST
)
7025 if (TREE_CODE (arg0
) == COMPLEX_CST
)
7028 if (TREE_CONSTANT (arg1
))
7030 if (TREE_CONSTANT (arg0
))
7036 if (reorder
&& flag_evaluation_order
7037 && (TREE_SIDE_EFFECTS (arg0
) || TREE_SIDE_EFFECTS (arg1
)))
7040 /* It is preferable to swap two SSA_NAME to ensure a canonical form
7041 for commutative and comparison operators. Ensuring a canonical
7042 form allows the optimizers to find additional redundancies without
7043 having to explicitly check for both orderings. */
7044 if (TREE_CODE (arg0
) == SSA_NAME
7045 && TREE_CODE (arg1
) == SSA_NAME
7046 && SSA_NAME_VERSION (arg0
) > SSA_NAME_VERSION (arg1
))
7049 /* Put SSA_NAMEs last. */
7050 if (TREE_CODE (arg1
) == SSA_NAME
)
7052 if (TREE_CODE (arg0
) == SSA_NAME
)
7055 /* Put variables last. */
7064 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
7065 ARG0 is extended to a wider type. */
7068 fold_widened_comparison (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
7070 tree arg0_unw
= get_unwidened (arg0
, NULL_TREE
);
7072 tree shorter_type
, outer_type
;
7076 if (arg0_unw
== arg0
)
7078 shorter_type
= TREE_TYPE (arg0_unw
);
7080 #ifdef HAVE_canonicalize_funcptr_for_compare
7081 /* Disable this optimization if we're casting a function pointer
7082 type on targets that require function pointer canonicalization. */
7083 if (HAVE_canonicalize_funcptr_for_compare
7084 && TREE_CODE (shorter_type
) == POINTER_TYPE
7085 && TREE_CODE (TREE_TYPE (shorter_type
)) == FUNCTION_TYPE
)
7089 if (TYPE_PRECISION (TREE_TYPE (arg0
)) <= TYPE_PRECISION (shorter_type
))
7092 arg1_unw
= get_unwidened (arg1
, shorter_type
);
7094 /* If possible, express the comparison in the shorter mode. */
7095 if ((code
== EQ_EXPR
|| code
== NE_EXPR
7096 || TYPE_UNSIGNED (TREE_TYPE (arg0
)) == TYPE_UNSIGNED (shorter_type
))
7097 && (TREE_TYPE (arg1_unw
) == shorter_type
7098 || (TREE_CODE (arg1_unw
) == INTEGER_CST
7099 && (TREE_CODE (shorter_type
) == INTEGER_TYPE
7100 || TREE_CODE (shorter_type
) == BOOLEAN_TYPE
)
7101 && int_fits_type_p (arg1_unw
, shorter_type
))))
7102 return fold_build2 (code
, type
, arg0_unw
,
7103 fold_convert (shorter_type
, arg1_unw
));
7105 if (TREE_CODE (arg1_unw
) != INTEGER_CST
7106 || TREE_CODE (shorter_type
) != INTEGER_TYPE
7107 || !int_fits_type_p (arg1_unw
, shorter_type
))
7110 /* If we are comparing with the integer that does not fit into the range
7111 of the shorter type, the result is known. */
7112 outer_type
= TREE_TYPE (arg1_unw
);
7113 min
= lower_bound_in_type (outer_type
, shorter_type
);
7114 max
= upper_bound_in_type (outer_type
, shorter_type
);
7116 above
= integer_nonzerop (fold_relational_const (LT_EXPR
, type
,
7118 below
= integer_nonzerop (fold_relational_const (LT_EXPR
, type
,
7125 return omit_one_operand (type
, integer_zero_node
, arg0
);
7130 return omit_one_operand (type
, integer_one_node
, arg0
);
7136 return omit_one_operand (type
, integer_one_node
, arg0
);
7138 return omit_one_operand (type
, integer_zero_node
, arg0
);
7143 return omit_one_operand (type
, integer_zero_node
, arg0
);
7145 return omit_one_operand (type
, integer_one_node
, arg0
);
7154 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
7155 ARG0 just the signedness is changed. */
7158 fold_sign_changed_comparison (enum tree_code code
, tree type
,
7159 tree arg0
, tree arg1
)
7162 tree inner_type
, outer_type
;
7164 if (TREE_CODE (arg0
) != NOP_EXPR
7165 && TREE_CODE (arg0
) != CONVERT_EXPR
)
7168 outer_type
= TREE_TYPE (arg0
);
7169 arg0_inner
= TREE_OPERAND (arg0
, 0);
7170 inner_type
= TREE_TYPE (arg0_inner
);
7172 #ifdef HAVE_canonicalize_funcptr_for_compare
7173 /* Disable this optimization if we're casting a function pointer
7174 type on targets that require function pointer canonicalization. */
7175 if (HAVE_canonicalize_funcptr_for_compare
7176 && TREE_CODE (inner_type
) == POINTER_TYPE
7177 && TREE_CODE (TREE_TYPE (inner_type
)) == FUNCTION_TYPE
)
7181 if (TYPE_PRECISION (inner_type
) != TYPE_PRECISION (outer_type
))
7184 if (TREE_CODE (arg1
) != INTEGER_CST
7185 && !((TREE_CODE (arg1
) == NOP_EXPR
7186 || TREE_CODE (arg1
) == CONVERT_EXPR
)
7187 && TREE_TYPE (TREE_OPERAND (arg1
, 0)) == inner_type
))
7190 if (TYPE_UNSIGNED (inner_type
) != TYPE_UNSIGNED (outer_type
)
7195 if (TREE_CODE (arg1
) == INTEGER_CST
)
7196 arg1
= force_fit_type_double (inner_type
, TREE_INT_CST_LOW (arg1
),
7197 TREE_INT_CST_HIGH (arg1
), 0,
7198 TREE_OVERFLOW (arg1
));
7200 arg1
= fold_convert (inner_type
, arg1
);
7202 return fold_build2 (code
, type
, arg0_inner
, arg1
);
7205 /* Tries to replace &a[idx] p+ s * delta with &a[idx + delta], if s is
7206 step of the array. Reconstructs s and delta in the case of s * delta
7207 being an integer constant (and thus already folded).
7208 ADDR is the address. MULT is the multiplicative expression.
7209 If the function succeeds, the new address expression is returned. Otherwise
7210 NULL_TREE is returned. */
7213 try_move_mult_to_index (tree addr
, tree op1
)
7215 tree s
, delta
, step
;
7216 tree ref
= TREE_OPERAND (addr
, 0), pref
;
7221 /* Strip the nops that might be added when converting op1 to sizetype. */
7224 /* Canonicalize op1 into a possibly non-constant delta
7225 and an INTEGER_CST s. */
7226 if (TREE_CODE (op1
) == MULT_EXPR
)
7228 tree arg0
= TREE_OPERAND (op1
, 0), arg1
= TREE_OPERAND (op1
, 1);
7233 if (TREE_CODE (arg0
) == INTEGER_CST
)
7238 else if (TREE_CODE (arg1
) == INTEGER_CST
)
7246 else if (TREE_CODE (op1
) == INTEGER_CST
)
7253 /* Simulate we are delta * 1. */
7255 s
= integer_one_node
;
7258 for (;; ref
= TREE_OPERAND (ref
, 0))
7260 if (TREE_CODE (ref
) == ARRAY_REF
)
7262 /* Remember if this was a multi-dimensional array. */
7263 if (TREE_CODE (TREE_OPERAND (ref
, 0)) == ARRAY_REF
)
7266 itype
= TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref
, 0)));
7270 step
= array_ref_element_size (ref
);
7271 if (TREE_CODE (step
) != INTEGER_CST
)
7276 if (! tree_int_cst_equal (step
, s
))
7281 /* Try if delta is a multiple of step. */
7282 tree tmp
= div_if_zero_remainder (EXACT_DIV_EXPR
, delta
, step
);
7288 /* Only fold here if we can verify we do not overflow one
7289 dimension of a multi-dimensional array. */
7294 if (TREE_CODE (TREE_OPERAND (ref
, 1)) != INTEGER_CST
7295 || !INTEGRAL_TYPE_P (itype
)
7296 || !TYPE_MAX_VALUE (itype
)
7297 || TREE_CODE (TYPE_MAX_VALUE (itype
)) != INTEGER_CST
)
7300 tmp
= fold_binary (PLUS_EXPR
, itype
,
7301 fold_convert (itype
,
7302 TREE_OPERAND (ref
, 1)),
7303 fold_convert (itype
, delta
));
7305 || TREE_CODE (tmp
) != INTEGER_CST
7306 || tree_int_cst_lt (TYPE_MAX_VALUE (itype
), tmp
))
7315 if (!handled_component_p (ref
))
7319 /* We found the suitable array reference. So copy everything up to it,
7320 and replace the index. */
7322 pref
= TREE_OPERAND (addr
, 0);
7323 ret
= copy_node (pref
);
7328 pref
= TREE_OPERAND (pref
, 0);
7329 TREE_OPERAND (pos
, 0) = copy_node (pref
);
7330 pos
= TREE_OPERAND (pos
, 0);
7333 TREE_OPERAND (pos
, 1) = fold_build2 (PLUS_EXPR
, itype
,
7334 fold_convert (itype
,
7335 TREE_OPERAND (pos
, 1)),
7336 fold_convert (itype
, delta
));
7338 return fold_build1 (ADDR_EXPR
, TREE_TYPE (addr
), ret
);
7342 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
7343 means A >= Y && A != MAX, but in this case we know that
7344 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
7347 fold_to_nonsharp_ineq_using_bound (tree ineq
, tree bound
)
7349 tree a
, typea
, type
= TREE_TYPE (ineq
), a1
, diff
, y
;
7351 if (TREE_CODE (bound
) == LT_EXPR
)
7352 a
= TREE_OPERAND (bound
, 0);
7353 else if (TREE_CODE (bound
) == GT_EXPR
)
7354 a
= TREE_OPERAND (bound
, 1);
7358 typea
= TREE_TYPE (a
);
7359 if (!INTEGRAL_TYPE_P (typea
)
7360 && !POINTER_TYPE_P (typea
))
7363 if (TREE_CODE (ineq
) == LT_EXPR
)
7365 a1
= TREE_OPERAND (ineq
, 1);
7366 y
= TREE_OPERAND (ineq
, 0);
7368 else if (TREE_CODE (ineq
) == GT_EXPR
)
7370 a1
= TREE_OPERAND (ineq
, 0);
7371 y
= TREE_OPERAND (ineq
, 1);
7376 if (TREE_TYPE (a1
) != typea
)
7379 if (POINTER_TYPE_P (typea
))
7381 /* Convert the pointer types into integer before taking the difference. */
7382 tree ta
= fold_convert (ssizetype
, a
);
7383 tree ta1
= fold_convert (ssizetype
, a1
);
7384 diff
= fold_binary (MINUS_EXPR
, ssizetype
, ta1
, ta
);
7387 diff
= fold_binary (MINUS_EXPR
, typea
, a1
, a
);
7389 if (!diff
|| !integer_onep (diff
))
7392 return fold_build2 (GE_EXPR
, type
, a
, y
);
7395 /* Fold a sum or difference of at least one multiplication.
7396 Returns the folded tree or NULL if no simplification could be made. */
7399 fold_plusminus_mult_expr (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
7401 tree arg00
, arg01
, arg10
, arg11
;
7402 tree alt0
= NULL_TREE
, alt1
= NULL_TREE
, same
;
7404 /* (A * C) +- (B * C) -> (A+-B) * C.
7405 (A * C) +- A -> A * (C+-1).
7406 We are most concerned about the case where C is a constant,
7407 but other combinations show up during loop reduction. Since
7408 it is not difficult, try all four possibilities. */
7410 if (TREE_CODE (arg0
) == MULT_EXPR
)
7412 arg00
= TREE_OPERAND (arg0
, 0);
7413 arg01
= TREE_OPERAND (arg0
, 1);
7415 else if (TREE_CODE (arg0
) == INTEGER_CST
)
7417 arg00
= build_one_cst (type
);
7422 /* We cannot generate constant 1 for fract. */
7423 if (ALL_FRACT_MODE_P (TYPE_MODE (type
)))
7426 arg01
= build_one_cst (type
);
7428 if (TREE_CODE (arg1
) == MULT_EXPR
)
7430 arg10
= TREE_OPERAND (arg1
, 0);
7431 arg11
= TREE_OPERAND (arg1
, 1);
7433 else if (TREE_CODE (arg1
) == INTEGER_CST
)
7435 arg10
= build_one_cst (type
);
7440 /* We cannot generate constant 1 for fract. */
7441 if (ALL_FRACT_MODE_P (TYPE_MODE (type
)))
7444 arg11
= build_one_cst (type
);
7448 if (operand_equal_p (arg01
, arg11
, 0))
7449 same
= arg01
, alt0
= arg00
, alt1
= arg10
;
7450 else if (operand_equal_p (arg00
, arg10
, 0))
7451 same
= arg00
, alt0
= arg01
, alt1
= arg11
;
7452 else if (operand_equal_p (arg00
, arg11
, 0))
7453 same
= arg00
, alt0
= arg01
, alt1
= arg10
;
7454 else if (operand_equal_p (arg01
, arg10
, 0))
7455 same
= arg01
, alt0
= arg00
, alt1
= arg11
;
7457 /* No identical multiplicands; see if we can find a common
7458 power-of-two factor in non-power-of-two multiplies. This
7459 can help in multi-dimensional array access. */
7460 else if (host_integerp (arg01
, 0)
7461 && host_integerp (arg11
, 0))
7463 HOST_WIDE_INT int01
, int11
, tmp
;
7466 int01
= TREE_INT_CST_LOW (arg01
);
7467 int11
= TREE_INT_CST_LOW (arg11
);
7469 /* Move min of absolute values to int11. */
7470 if ((int01
>= 0 ? int01
: -int01
)
7471 < (int11
>= 0 ? int11
: -int11
))
7473 tmp
= int01
, int01
= int11
, int11
= tmp
;
7474 alt0
= arg00
, arg00
= arg10
, arg10
= alt0
;
7481 if (exact_log2 (abs (int11
)) > 0 && int01
% int11
== 0)
7483 alt0
= fold_build2 (MULT_EXPR
, TREE_TYPE (arg00
), arg00
,
7484 build_int_cst (TREE_TYPE (arg00
),
7489 maybe_same
= alt0
, alt0
= alt1
, alt1
= maybe_same
;
7494 return fold_build2 (MULT_EXPR
, type
,
7495 fold_build2 (code
, type
,
7496 fold_convert (type
, alt0
),
7497 fold_convert (type
, alt1
)),
7498 fold_convert (type
, same
));
7503 /* Subroutine of native_encode_expr. Encode the INTEGER_CST
7504 specified by EXPR into the buffer PTR of length LEN bytes.
7505 Return the number of bytes placed in the buffer, or zero
7509 native_encode_int (const_tree expr
, unsigned char *ptr
, int len
)
7511 tree type
= TREE_TYPE (expr
);
7512 int total_bytes
= GET_MODE_SIZE (TYPE_MODE (type
));
7513 int byte
, offset
, word
, words
;
7514 unsigned char value
;
7516 if (total_bytes
> len
)
7518 words
= total_bytes
/ UNITS_PER_WORD
;
7520 for (byte
= 0; byte
< total_bytes
; byte
++)
7522 int bitpos
= byte
* BITS_PER_UNIT
;
7523 if (bitpos
< HOST_BITS_PER_WIDE_INT
)
7524 value
= (unsigned char) (TREE_INT_CST_LOW (expr
) >> bitpos
);
7526 value
= (unsigned char) (TREE_INT_CST_HIGH (expr
)
7527 >> (bitpos
- HOST_BITS_PER_WIDE_INT
));
7529 if (total_bytes
> UNITS_PER_WORD
)
7531 word
= byte
/ UNITS_PER_WORD
;
7532 if (WORDS_BIG_ENDIAN
)
7533 word
= (words
- 1) - word
;
7534 offset
= word
* UNITS_PER_WORD
;
7535 if (BYTES_BIG_ENDIAN
)
7536 offset
+= (UNITS_PER_WORD
- 1) - (byte
% UNITS_PER_WORD
);
7538 offset
+= byte
% UNITS_PER_WORD
;
7541 offset
= BYTES_BIG_ENDIAN
? (total_bytes
- 1) - byte
: byte
;
7542 ptr
[offset
] = value
;
7548 /* Subroutine of native_encode_expr. Encode the REAL_CST
7549 specified by EXPR into the buffer PTR of length LEN bytes.
7550 Return the number of bytes placed in the buffer, or zero
7554 native_encode_real (const_tree expr
, unsigned char *ptr
, int len
)
7556 tree type
= TREE_TYPE (expr
);
7557 int total_bytes
= GET_MODE_SIZE (TYPE_MODE (type
));
7558 int byte
, offset
, word
, words
, bitpos
;
7559 unsigned char value
;
7561 /* There are always 32 bits in each long, no matter the size of
7562 the hosts long. We handle floating point representations with
7566 if (total_bytes
> len
)
7568 words
= 32 / UNITS_PER_WORD
;
7570 real_to_target (tmp
, TREE_REAL_CST_PTR (expr
), TYPE_MODE (type
));
7572 for (bitpos
= 0; bitpos
< total_bytes
* BITS_PER_UNIT
;
7573 bitpos
+= BITS_PER_UNIT
)
7575 byte
= (bitpos
/ BITS_PER_UNIT
) & 3;
7576 value
= (unsigned char) (tmp
[bitpos
/ 32] >> (bitpos
& 31));
7578 if (UNITS_PER_WORD
< 4)
7580 word
= byte
/ UNITS_PER_WORD
;
7581 if (WORDS_BIG_ENDIAN
)
7582 word
= (words
- 1) - word
;
7583 offset
= word
* UNITS_PER_WORD
;
7584 if (BYTES_BIG_ENDIAN
)
7585 offset
+= (UNITS_PER_WORD
- 1) - (byte
% UNITS_PER_WORD
);
7587 offset
+= byte
% UNITS_PER_WORD
;
7590 offset
= BYTES_BIG_ENDIAN
? 3 - byte
: byte
;
7591 ptr
[offset
+ ((bitpos
/ BITS_PER_UNIT
) & ~3)] = value
;
7596 /* Subroutine of native_encode_expr. Encode the COMPLEX_CST
7597 specified by EXPR into the buffer PTR of length LEN bytes.
7598 Return the number of bytes placed in the buffer, or zero
7602 native_encode_complex (const_tree expr
, unsigned char *ptr
, int len
)
7607 part
= TREE_REALPART (expr
);
7608 rsize
= native_encode_expr (part
, ptr
, len
);
7611 part
= TREE_IMAGPART (expr
);
7612 isize
= native_encode_expr (part
, ptr
+rsize
, len
-rsize
);
7615 return rsize
+ isize
;
7619 /* Subroutine of native_encode_expr. Encode the VECTOR_CST
7620 specified by EXPR into the buffer PTR of length LEN bytes.
7621 Return the number of bytes placed in the buffer, or zero
7625 native_encode_vector (const_tree expr
, unsigned char *ptr
, int len
)
7627 int i
, size
, offset
, count
;
7628 tree itype
, elem
, elements
;
7631 elements
= TREE_VECTOR_CST_ELTS (expr
);
7632 count
= TYPE_VECTOR_SUBPARTS (TREE_TYPE (expr
));
7633 itype
= TREE_TYPE (TREE_TYPE (expr
));
7634 size
= GET_MODE_SIZE (TYPE_MODE (itype
));
7635 for (i
= 0; i
< count
; i
++)
7639 elem
= TREE_VALUE (elements
);
7640 elements
= TREE_CHAIN (elements
);
7647 if (native_encode_expr (elem
, ptr
+offset
, len
-offset
) != size
)
7652 if (offset
+ size
> len
)
7654 memset (ptr
+offset
, 0, size
);
7662 /* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST,
7663 REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
7664 buffer PTR of length LEN bytes. Return the number of bytes
7665 placed in the buffer, or zero upon failure. */
7668 native_encode_expr (const_tree expr
, unsigned char *ptr
, int len
)
7670 switch (TREE_CODE (expr
))
7673 return native_encode_int (expr
, ptr
, len
);
7676 return native_encode_real (expr
, ptr
, len
);
7679 return native_encode_complex (expr
, ptr
, len
);
7682 return native_encode_vector (expr
, ptr
, len
);
7690 /* Subroutine of native_interpret_expr. Interpret the contents of
7691 the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
7692 If the buffer cannot be interpreted, return NULL_TREE. */
7695 native_interpret_int (tree type
, const unsigned char *ptr
, int len
)
7697 int total_bytes
= GET_MODE_SIZE (TYPE_MODE (type
));
7698 int byte
, offset
, word
, words
;
7699 unsigned char value
;
7700 unsigned int HOST_WIDE_INT lo
= 0;
7701 HOST_WIDE_INT hi
= 0;
7703 if (total_bytes
> len
)
7705 if (total_bytes
* BITS_PER_UNIT
> 2 * HOST_BITS_PER_WIDE_INT
)
7707 words
= total_bytes
/ UNITS_PER_WORD
;
7709 for (byte
= 0; byte
< total_bytes
; byte
++)
7711 int bitpos
= byte
* BITS_PER_UNIT
;
7712 if (total_bytes
> UNITS_PER_WORD
)
7714 word
= byte
/ UNITS_PER_WORD
;
7715 if (WORDS_BIG_ENDIAN
)
7716 word
= (words
- 1) - word
;
7717 offset
= word
* UNITS_PER_WORD
;
7718 if (BYTES_BIG_ENDIAN
)
7719 offset
+= (UNITS_PER_WORD
- 1) - (byte
% UNITS_PER_WORD
);
7721 offset
+= byte
% UNITS_PER_WORD
;
7724 offset
= BYTES_BIG_ENDIAN
? (total_bytes
- 1) - byte
: byte
;
7725 value
= ptr
[offset
];
7727 if (bitpos
< HOST_BITS_PER_WIDE_INT
)
7728 lo
|= (unsigned HOST_WIDE_INT
) value
<< bitpos
;
7730 hi
|= (unsigned HOST_WIDE_INT
) value
7731 << (bitpos
- HOST_BITS_PER_WIDE_INT
);
7734 return build_int_cst_wide_type (type
, lo
, hi
);
7738 /* Subroutine of native_interpret_expr. Interpret the contents of
7739 the buffer PTR of length LEN as a REAL_CST of type TYPE.
7740 If the buffer cannot be interpreted, return NULL_TREE. */
7743 native_interpret_real (tree type
, const unsigned char *ptr
, int len
)
7745 enum machine_mode mode
= TYPE_MODE (type
);
7746 int total_bytes
= GET_MODE_SIZE (mode
);
7747 int byte
, offset
, word
, words
, bitpos
;
7748 unsigned char value
;
7749 /* There are always 32 bits in each long, no matter the size of
7750 the hosts long. We handle floating point representations with
7755 total_bytes
= GET_MODE_SIZE (TYPE_MODE (type
));
7756 if (total_bytes
> len
|| total_bytes
> 24)
7758 words
= 32 / UNITS_PER_WORD
;
7760 memset (tmp
, 0, sizeof (tmp
));
7761 for (bitpos
= 0; bitpos
< total_bytes
* BITS_PER_UNIT
;
7762 bitpos
+= BITS_PER_UNIT
)
7764 byte
= (bitpos
/ BITS_PER_UNIT
) & 3;
7765 if (UNITS_PER_WORD
< 4)
7767 word
= byte
/ UNITS_PER_WORD
;
7768 if (WORDS_BIG_ENDIAN
)
7769 word
= (words
- 1) - word
;
7770 offset
= word
* UNITS_PER_WORD
;
7771 if (BYTES_BIG_ENDIAN
)
7772 offset
+= (UNITS_PER_WORD
- 1) - (byte
% UNITS_PER_WORD
);
7774 offset
+= byte
% UNITS_PER_WORD
;
7777 offset
= BYTES_BIG_ENDIAN
? 3 - byte
: byte
;
7778 value
= ptr
[offset
+ ((bitpos
/ BITS_PER_UNIT
) & ~3)];
7780 tmp
[bitpos
/ 32] |= (unsigned long)value
<< (bitpos
& 31);
7783 real_from_target (&r
, tmp
, mode
);
7784 return build_real (type
, r
);
7788 /* Subroutine of native_interpret_expr. Interpret the contents of
7789 the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
7790 If the buffer cannot be interpreted, return NULL_TREE. */
7793 native_interpret_complex (tree type
, const unsigned char *ptr
, int len
)
7795 tree etype
, rpart
, ipart
;
7798 etype
= TREE_TYPE (type
);
7799 size
= GET_MODE_SIZE (TYPE_MODE (etype
));
7802 rpart
= native_interpret_expr (etype
, ptr
, size
);
7805 ipart
= native_interpret_expr (etype
, ptr
+size
, size
);
7808 return build_complex (type
, rpart
, ipart
);
7812 /* Subroutine of native_interpret_expr. Interpret the contents of
7813 the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
7814 If the buffer cannot be interpreted, return NULL_TREE. */
7817 native_interpret_vector (tree type
, const unsigned char *ptr
, int len
)
7819 tree etype
, elem
, elements
;
7822 etype
= TREE_TYPE (type
);
7823 size
= GET_MODE_SIZE (TYPE_MODE (etype
));
7824 count
= TYPE_VECTOR_SUBPARTS (type
);
7825 if (size
* count
> len
)
7828 elements
= NULL_TREE
;
7829 for (i
= count
- 1; i
>= 0; i
--)
7831 elem
= native_interpret_expr (etype
, ptr
+(i
*size
), size
);
7834 elements
= tree_cons (NULL_TREE
, elem
, elements
);
7836 return build_vector (type
, elements
);
7840 /* Subroutine of fold_view_convert_expr. Interpret the contents of
7841 the buffer PTR of length LEN as a constant of type TYPE. For
7842 INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
7843 we return a REAL_CST, etc... If the buffer cannot be interpreted,
7844 return NULL_TREE. */
7847 native_interpret_expr (tree type
, const unsigned char *ptr
, int len
)
7849 switch (TREE_CODE (type
))
7854 return native_interpret_int (type
, ptr
, len
);
7857 return native_interpret_real (type
, ptr
, len
);
7860 return native_interpret_complex (type
, ptr
, len
);
7863 return native_interpret_vector (type
, ptr
, len
);
7871 /* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
7872 TYPE at compile-time. If we're unable to perform the conversion
7873 return NULL_TREE. */
7876 fold_view_convert_expr (tree type
, tree expr
)
7878 /* We support up to 512-bit values (for V8DFmode). */
7879 unsigned char buffer
[64];
7882 /* Check that the host and target are sane. */
7883 if (CHAR_BIT
!= 8 || BITS_PER_UNIT
!= 8)
7886 len
= native_encode_expr (expr
, buffer
, sizeof (buffer
));
7890 return native_interpret_expr (type
, buffer
, len
);
7893 /* Build an expression for the address of T. Folds away INDIRECT_REF
7894 to avoid confusing the gimplify process. When IN_FOLD is true
7895 avoid modifications of T. */
7898 build_fold_addr_expr_with_type_1 (tree t
, tree ptrtype
, bool in_fold
)
7900 /* The size of the object is not relevant when talking about its address. */
7901 if (TREE_CODE (t
) == WITH_SIZE_EXPR
)
7902 t
= TREE_OPERAND (t
, 0);
7904 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
7905 if (TREE_CODE (t
) == INDIRECT_REF
7906 || TREE_CODE (t
) == MISALIGNED_INDIRECT_REF
)
7908 t
= TREE_OPERAND (t
, 0);
7910 if (TREE_TYPE (t
) != ptrtype
)
7911 t
= build1 (NOP_EXPR
, ptrtype
, t
);
7917 while (handled_component_p (base
))
7918 base
= TREE_OPERAND (base
, 0);
7921 TREE_ADDRESSABLE (base
) = 1;
7923 t
= build1 (ADDR_EXPR
, ptrtype
, t
);
7926 t
= build1 (ADDR_EXPR
, ptrtype
, t
);
7931 /* Build an expression for the address of T with type PTRTYPE. This
7932 function modifies the input parameter 'T' by sometimes setting the
7933 TREE_ADDRESSABLE flag. */
7936 build_fold_addr_expr_with_type (tree t
, tree ptrtype
)
7938 return build_fold_addr_expr_with_type_1 (t
, ptrtype
, false);
7941 /* Build an expression for the address of T. This function modifies
7942 the input parameter 'T' by sometimes setting the TREE_ADDRESSABLE
7943 flag. When called from fold functions, use fold_addr_expr instead. */
7946 build_fold_addr_expr (tree t
)
7948 return build_fold_addr_expr_with_type_1 (t
,
7949 build_pointer_type (TREE_TYPE (t
)),
7953 /* Same as build_fold_addr_expr, builds an expression for the address
7954 of T, but avoids touching the input node 't'. Fold functions
7955 should use this version. */
7958 fold_addr_expr (tree t
)
7960 tree ptrtype
= build_pointer_type (TREE_TYPE (t
));
7962 return build_fold_addr_expr_with_type_1 (t
, ptrtype
, true);
7965 /* Fold a unary expression of code CODE and type TYPE with operand
7966 OP0. Return the folded expression if folding is successful.
7967 Otherwise, return NULL_TREE. */
7970 fold_unary (enum tree_code code
, tree type
, tree op0
)
7974 enum tree_code_class kind
= TREE_CODE_CLASS (code
);
7976 gcc_assert (IS_EXPR_CODE_CLASS (kind
)
7977 && TREE_CODE_LENGTH (code
) == 1);
7982 if (code
== NOP_EXPR
|| code
== CONVERT_EXPR
7983 || code
== FLOAT_EXPR
|| code
== ABS_EXPR
)
7985 /* Don't use STRIP_NOPS, because signedness of argument type
7987 STRIP_SIGN_NOPS (arg0
);
7991 /* Strip any conversions that don't change the mode. This
7992 is safe for every expression, except for a comparison
7993 expression because its signedness is derived from its
7996 Note that this is done as an internal manipulation within
7997 the constant folder, in order to find the simplest
7998 representation of the arguments so that their form can be
7999 studied. In any cases, the appropriate type conversions
8000 should be put back in the tree that will get out of the
8006 if (TREE_CODE_CLASS (code
) == tcc_unary
)
8008 if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
8009 return build2 (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
8010 fold_build1 (code
, type
, TREE_OPERAND (arg0
, 1)));
8011 else if (TREE_CODE (arg0
) == COND_EXPR
)
8013 tree arg01
= TREE_OPERAND (arg0
, 1);
8014 tree arg02
= TREE_OPERAND (arg0
, 2);
8015 if (! VOID_TYPE_P (TREE_TYPE (arg01
)))
8016 arg01
= fold_build1 (code
, type
, arg01
);
8017 if (! VOID_TYPE_P (TREE_TYPE (arg02
)))
8018 arg02
= fold_build1 (code
, type
, arg02
);
8019 tem
= fold_build3 (COND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
8022 /* If this was a conversion, and all we did was to move into
8023 inside the COND_EXPR, bring it back out. But leave it if
8024 it is a conversion from integer to integer and the
8025 result precision is no wider than a word since such a
8026 conversion is cheap and may be optimized away by combine,
8027 while it couldn't if it were outside the COND_EXPR. Then return
8028 so we don't get into an infinite recursion loop taking the
8029 conversion out and then back in. */
8031 if ((code
== NOP_EXPR
|| code
== CONVERT_EXPR
8032 || code
== NON_LVALUE_EXPR
)
8033 && TREE_CODE (tem
) == COND_EXPR
8034 && TREE_CODE (TREE_OPERAND (tem
, 1)) == code
8035 && TREE_CODE (TREE_OPERAND (tem
, 2)) == code
8036 && ! VOID_TYPE_P (TREE_OPERAND (tem
, 1))
8037 && ! VOID_TYPE_P (TREE_OPERAND (tem
, 2))
8038 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem
, 1), 0))
8039 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem
, 2), 0)))
8040 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem
))
8042 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem
, 1), 0))))
8043 && TYPE_PRECISION (TREE_TYPE (tem
)) <= BITS_PER_WORD
)
8044 || flag_syntax_only
))
8045 tem
= build1 (code
, type
,
8047 TREE_TYPE (TREE_OPERAND
8048 (TREE_OPERAND (tem
, 1), 0)),
8049 TREE_OPERAND (tem
, 0),
8050 TREE_OPERAND (TREE_OPERAND (tem
, 1), 0),
8051 TREE_OPERAND (TREE_OPERAND (tem
, 2), 0)));
8054 else if (COMPARISON_CLASS_P (arg0
))
8056 if (TREE_CODE (type
) == BOOLEAN_TYPE
)
8058 arg0
= copy_node (arg0
);
8059 TREE_TYPE (arg0
) = type
;
8062 else if (TREE_CODE (type
) != INTEGER_TYPE
)
8063 return fold_build3 (COND_EXPR
, type
, arg0
,
8064 fold_build1 (code
, type
,
8066 fold_build1 (code
, type
,
8067 integer_zero_node
));
8076 case FIX_TRUNC_EXPR
:
8077 if (TREE_TYPE (op0
) == type
)
8080 /* If we have (type) (a CMP b) and type is an integral type, return
8081 new expression involving the new type. */
8082 if (COMPARISON_CLASS_P (op0
) && INTEGRAL_TYPE_P (type
))
8083 return fold_build2 (TREE_CODE (op0
), type
, TREE_OPERAND (op0
, 0),
8084 TREE_OPERAND (op0
, 1));
8086 /* Handle cases of two conversions in a row. */
8087 if (TREE_CODE (op0
) == NOP_EXPR
8088 || TREE_CODE (op0
) == CONVERT_EXPR
)
8090 tree inside_type
= TREE_TYPE (TREE_OPERAND (op0
, 0));
8091 tree inter_type
= TREE_TYPE (op0
);
8092 int inside_int
= INTEGRAL_TYPE_P (inside_type
);
8093 int inside_ptr
= POINTER_TYPE_P (inside_type
);
8094 int inside_float
= FLOAT_TYPE_P (inside_type
);
8095 int inside_vec
= TREE_CODE (inside_type
) == VECTOR_TYPE
;
8096 unsigned int inside_prec
= TYPE_PRECISION (inside_type
);
8097 int inside_unsignedp
= TYPE_UNSIGNED (inside_type
);
8098 int inter_int
= INTEGRAL_TYPE_P (inter_type
);
8099 int inter_ptr
= POINTER_TYPE_P (inter_type
);
8100 int inter_float
= FLOAT_TYPE_P (inter_type
);
8101 int inter_vec
= TREE_CODE (inter_type
) == VECTOR_TYPE
;
8102 unsigned int inter_prec
= TYPE_PRECISION (inter_type
);
8103 int inter_unsignedp
= TYPE_UNSIGNED (inter_type
);
8104 int final_int
= INTEGRAL_TYPE_P (type
);
8105 int final_ptr
= POINTER_TYPE_P (type
);
8106 int final_float
= FLOAT_TYPE_P (type
);
8107 int final_vec
= TREE_CODE (type
) == VECTOR_TYPE
;
8108 unsigned int final_prec
= TYPE_PRECISION (type
);
8109 int final_unsignedp
= TYPE_UNSIGNED (type
);
8111 /* In addition to the cases of two conversions in a row
8112 handled below, if we are converting something to its own
8113 type via an object of identical or wider precision, neither
8114 conversion is needed. */
8115 if (TYPE_MAIN_VARIANT (inside_type
) == TYPE_MAIN_VARIANT (type
)
8116 && (((inter_int
|| inter_ptr
) && final_int
)
8117 || (inter_float
&& final_float
))
8118 && inter_prec
>= final_prec
)
8119 return fold_build1 (code
, type
, TREE_OPERAND (op0
, 0));
8121 /* Likewise, if the intermediate and final types are either both
8122 float or both integer, we don't need the middle conversion if
8123 it is wider than the final type and doesn't change the signedness
8124 (for integers). Avoid this if the final type is a pointer
8125 since then we sometimes need the inner conversion. Likewise if
8126 the outer has a precision not equal to the size of its mode. */
8127 if ((((inter_int
|| inter_ptr
) && (inside_int
|| inside_ptr
))
8128 || (inter_float
&& inside_float
)
8129 || (inter_vec
&& inside_vec
))
8130 && inter_prec
>= inside_prec
8131 && (inter_float
|| inter_vec
8132 || inter_unsignedp
== inside_unsignedp
)
8133 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (type
))
8134 && TYPE_MODE (type
) == TYPE_MODE (inter_type
))
8136 && (! final_vec
|| inter_prec
== inside_prec
))
8137 return fold_build1 (code
, type
, TREE_OPERAND (op0
, 0));
8139 /* If we have a sign-extension of a zero-extended value, we can
8140 replace that by a single zero-extension. */
8141 if (inside_int
&& inter_int
&& final_int
8142 && inside_prec
< inter_prec
&& inter_prec
< final_prec
8143 && inside_unsignedp
&& !inter_unsignedp
)
8144 return fold_build1 (code
, type
, TREE_OPERAND (op0
, 0));
8146 /* Two conversions in a row are not needed unless:
8147 - some conversion is floating-point (overstrict for now), or
8148 - some conversion is a vector (overstrict for now), or
8149 - the intermediate type is narrower than both initial and
8151 - the intermediate type and innermost type differ in signedness,
8152 and the outermost type is wider than the intermediate, or
8153 - the initial type is a pointer type and the precisions of the
8154 intermediate and final types differ, or
8155 - the final type is a pointer type and the precisions of the
8156 initial and intermediate types differ.
8157 - the final type is a pointer type and the initial type not
8158 - the initial type is a pointer to an array and the final type
8160 if (! inside_float
&& ! inter_float
&& ! final_float
8161 && ! inside_vec
&& ! inter_vec
&& ! final_vec
8162 && (inter_prec
>= inside_prec
|| inter_prec
>= final_prec
)
8163 && ! (inside_int
&& inter_int
8164 && inter_unsignedp
!= inside_unsignedp
8165 && inter_prec
< final_prec
)
8166 && ((inter_unsignedp
&& inter_prec
> inside_prec
)
8167 == (final_unsignedp
&& final_prec
> inter_prec
))
8168 && ! (inside_ptr
&& inter_prec
!= final_prec
)
8169 && ! (final_ptr
&& inside_prec
!= inter_prec
)
8170 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (type
))
8171 && TYPE_MODE (type
) == TYPE_MODE (inter_type
))
8172 && final_ptr
== inside_ptr
8174 && TREE_CODE (TREE_TYPE (inside_type
)) == ARRAY_TYPE
8175 && TREE_CODE (TREE_TYPE (type
)) != ARRAY_TYPE
))
8176 return fold_build1 (code
, type
, TREE_OPERAND (op0
, 0));
8179 /* Handle (T *)&A.B.C for A being of type T and B and C
8180 living at offset zero. This occurs frequently in
8181 C++ upcasting and then accessing the base. */
8182 if (TREE_CODE (op0
) == ADDR_EXPR
8183 && POINTER_TYPE_P (type
)
8184 && handled_component_p (TREE_OPERAND (op0
, 0)))
8186 HOST_WIDE_INT bitsize
, bitpos
;
8188 enum machine_mode mode
;
8189 int unsignedp
, volatilep
;
8190 tree base
= TREE_OPERAND (op0
, 0);
8191 base
= get_inner_reference (base
, &bitsize
, &bitpos
, &offset
,
8192 &mode
, &unsignedp
, &volatilep
, false);
8193 /* If the reference was to a (constant) zero offset, we can use
8194 the address of the base if it has the same base type
8195 as the result type. */
8196 if (! offset
&& bitpos
== 0
8197 && TYPE_MAIN_VARIANT (TREE_TYPE (type
))
8198 == TYPE_MAIN_VARIANT (TREE_TYPE (base
)))
8199 return fold_convert (type
, fold_addr_expr (base
));
8202 if ((TREE_CODE (op0
) == MODIFY_EXPR
8203 || TREE_CODE (op0
) == GIMPLE_MODIFY_STMT
)
8204 && TREE_CONSTANT (GENERIC_TREE_OPERAND (op0
, 1))
8205 /* Detect assigning a bitfield. */
8206 && !(TREE_CODE (GENERIC_TREE_OPERAND (op0
, 0)) == COMPONENT_REF
8208 (TREE_OPERAND (GENERIC_TREE_OPERAND (op0
, 0), 1))))
8210 /* Don't leave an assignment inside a conversion
8211 unless assigning a bitfield. */
8212 tem
= fold_build1 (code
, type
, GENERIC_TREE_OPERAND (op0
, 1));
8213 /* First do the assignment, then return converted constant. */
8214 tem
= build2 (COMPOUND_EXPR
, TREE_TYPE (tem
), op0
, tem
);
8215 TREE_NO_WARNING (tem
) = 1;
8216 TREE_USED (tem
) = 1;
8220 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
8221 constants (if x has signed type, the sign bit cannot be set
8222 in c). This folds extension into the BIT_AND_EXPR. */
8223 if (INTEGRAL_TYPE_P (type
)
8224 && TREE_CODE (type
) != BOOLEAN_TYPE
8225 && TREE_CODE (op0
) == BIT_AND_EXPR
8226 && TREE_CODE (TREE_OPERAND (op0
, 1)) == INTEGER_CST
)
8229 tree and0
= TREE_OPERAND (and, 0), and1
= TREE_OPERAND (and, 1);
8232 if (TYPE_UNSIGNED (TREE_TYPE (and))
8233 || (TYPE_PRECISION (type
)
8234 <= TYPE_PRECISION (TREE_TYPE (and))))
8236 else if (TYPE_PRECISION (TREE_TYPE (and1
))
8237 <= HOST_BITS_PER_WIDE_INT
8238 && host_integerp (and1
, 1))
8240 unsigned HOST_WIDE_INT cst
;
8242 cst
= tree_low_cst (and1
, 1);
8243 cst
&= (HOST_WIDE_INT
) -1
8244 << (TYPE_PRECISION (TREE_TYPE (and1
)) - 1);
8245 change
= (cst
== 0);
8246 #ifdef LOAD_EXTEND_OP
8248 && !flag_syntax_only
8249 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0
)))
8252 tree uns
= unsigned_type_for (TREE_TYPE (and0
));
8253 and0
= fold_convert (uns
, and0
);
8254 and1
= fold_convert (uns
, and1
);
8260 tem
= force_fit_type_double (type
, TREE_INT_CST_LOW (and1
),
8261 TREE_INT_CST_HIGH (and1
), 0,
8262 TREE_OVERFLOW (and1
));
8263 return fold_build2 (BIT_AND_EXPR
, type
,
8264 fold_convert (type
, and0
), tem
);
8268 /* Convert (T1)(X p+ Y) into ((T1)X p+ Y), for pointer type,
8269 when one of the new casts will fold away. Conservatively we assume
8270 that this happens when X or Y is NOP_EXPR or Y is INTEGER_CST. */
8271 if (POINTER_TYPE_P (type
)
8272 && TREE_CODE (arg0
) == POINTER_PLUS_EXPR
8273 && (TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
8274 || TREE_CODE (TREE_OPERAND (arg0
, 0)) == NOP_EXPR
8275 || TREE_CODE (TREE_OPERAND (arg0
, 1)) == NOP_EXPR
))
8277 tree arg00
= TREE_OPERAND (arg0
, 0);
8278 tree arg01
= TREE_OPERAND (arg0
, 1);
8280 return fold_build2 (TREE_CODE (arg0
), type
, fold_convert (type
, arg00
),
8281 fold_convert (sizetype
, arg01
));
8284 /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
8285 of the same precision, and X is an integer type not narrower than
8286 types T1 or T2, i.e. the cast (T2)X isn't an extension. */
8287 if (INTEGRAL_TYPE_P (type
)
8288 && TREE_CODE (op0
) == BIT_NOT_EXPR
8289 && INTEGRAL_TYPE_P (TREE_TYPE (op0
))
8290 && (TREE_CODE (TREE_OPERAND (op0
, 0)) == NOP_EXPR
8291 || TREE_CODE (TREE_OPERAND (op0
, 0)) == CONVERT_EXPR
)
8292 && TYPE_PRECISION (type
) == TYPE_PRECISION (TREE_TYPE (op0
)))
8294 tem
= TREE_OPERAND (TREE_OPERAND (op0
, 0), 0);
8295 if (INTEGRAL_TYPE_P (TREE_TYPE (tem
))
8296 && TYPE_PRECISION (type
) <= TYPE_PRECISION (TREE_TYPE (tem
)))
8297 return fold_build1 (BIT_NOT_EXPR
, type
, fold_convert (type
, tem
));
8300 tem
= fold_convert_const (code
, type
, op0
);
8301 return tem
? tem
: NULL_TREE
;
8303 case FIXED_CONVERT_EXPR
:
8304 tem
= fold_convert_const (code
, type
, arg0
);
8305 return tem
? tem
: NULL_TREE
;
8307 case VIEW_CONVERT_EXPR
:
8308 if (TREE_TYPE (op0
) == type
)
8310 if (TREE_CODE (op0
) == VIEW_CONVERT_EXPR
)
8311 return fold_build1 (VIEW_CONVERT_EXPR
, type
, TREE_OPERAND (op0
, 0));
8312 return fold_view_convert_expr (type
, op0
);
8315 tem
= fold_negate_expr (arg0
);
8317 return fold_convert (type
, tem
);
8321 if (TREE_CODE (arg0
) == INTEGER_CST
|| TREE_CODE (arg0
) == REAL_CST
)
8322 return fold_abs_const (arg0
, type
);
8323 else if (TREE_CODE (arg0
) == NEGATE_EXPR
)
8324 return fold_build1 (ABS_EXPR
, type
, TREE_OPERAND (arg0
, 0));
8325 /* Convert fabs((double)float) into (double)fabsf(float). */
8326 else if (TREE_CODE (arg0
) == NOP_EXPR
8327 && TREE_CODE (type
) == REAL_TYPE
)
8329 tree targ0
= strip_float_extensions (arg0
);
8331 return fold_convert (type
, fold_build1 (ABS_EXPR
,
8335 /* ABS_EXPR<ABS_EXPR<x>> = ABS_EXPR<x> even if flag_wrapv is on. */
8336 else if (TREE_CODE (arg0
) == ABS_EXPR
)
8338 else if (tree_expr_nonnegative_p (arg0
))
8341 /* Strip sign ops from argument. */
8342 if (TREE_CODE (type
) == REAL_TYPE
)
8344 tem
= fold_strip_sign_ops (arg0
);
8346 return fold_build1 (ABS_EXPR
, type
, fold_convert (type
, tem
));
8351 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
8352 return fold_convert (type
, arg0
);
8353 if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
8355 tree itype
= TREE_TYPE (type
);
8356 tree rpart
= fold_convert (itype
, TREE_OPERAND (arg0
, 0));
8357 tree ipart
= fold_convert (itype
, TREE_OPERAND (arg0
, 1));
8358 return fold_build2 (COMPLEX_EXPR
, type
, rpart
, negate_expr (ipart
));
8360 if (TREE_CODE (arg0
) == COMPLEX_CST
)
8362 tree itype
= TREE_TYPE (type
);
8363 tree rpart
= fold_convert (itype
, TREE_REALPART (arg0
));
8364 tree ipart
= fold_convert (itype
, TREE_IMAGPART (arg0
));
8365 return build_complex (type
, rpart
, negate_expr (ipart
));
8367 if (TREE_CODE (arg0
) == CONJ_EXPR
)
8368 return fold_convert (type
, TREE_OPERAND (arg0
, 0));
8372 if (TREE_CODE (arg0
) == INTEGER_CST
)
8373 return fold_not_const (arg0
, type
);
8374 else if (TREE_CODE (arg0
) == BIT_NOT_EXPR
)
8375 return TREE_OPERAND (arg0
, 0);
8376 /* Convert ~ (-A) to A - 1. */
8377 else if (INTEGRAL_TYPE_P (type
) && TREE_CODE (arg0
) == NEGATE_EXPR
)
8378 return fold_build2 (MINUS_EXPR
, type
, TREE_OPERAND (arg0
, 0),
8379 build_int_cst (type
, 1));
8380 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
8381 else if (INTEGRAL_TYPE_P (type
)
8382 && ((TREE_CODE (arg0
) == MINUS_EXPR
8383 && integer_onep (TREE_OPERAND (arg0
, 1)))
8384 || (TREE_CODE (arg0
) == PLUS_EXPR
8385 && integer_all_onesp (TREE_OPERAND (arg0
, 1)))))
8386 return fold_build1 (NEGATE_EXPR
, type
, TREE_OPERAND (arg0
, 0));
8387 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
8388 else if (TREE_CODE (arg0
) == BIT_XOR_EXPR
8389 && (tem
= fold_unary (BIT_NOT_EXPR
, type
,
8391 TREE_OPERAND (arg0
, 0)))))
8392 return fold_build2 (BIT_XOR_EXPR
, type
, tem
,
8393 fold_convert (type
, TREE_OPERAND (arg0
, 1)));
8394 else if (TREE_CODE (arg0
) == BIT_XOR_EXPR
8395 && (tem
= fold_unary (BIT_NOT_EXPR
, type
,
8397 TREE_OPERAND (arg0
, 1)))))
8398 return fold_build2 (BIT_XOR_EXPR
, type
,
8399 fold_convert (type
, TREE_OPERAND (arg0
, 0)), tem
);
8400 /* Perform BIT_NOT_EXPR on each element individually. */
8401 else if (TREE_CODE (arg0
) == VECTOR_CST
)
8403 tree elements
= TREE_VECTOR_CST_ELTS (arg0
), elem
, list
= NULL_TREE
;
8404 int count
= TYPE_VECTOR_SUBPARTS (type
), i
;
8406 for (i
= 0; i
< count
; i
++)
8410 elem
= TREE_VALUE (elements
);
8411 elem
= fold_unary (BIT_NOT_EXPR
, TREE_TYPE (type
), elem
);
8412 if (elem
== NULL_TREE
)
8414 elements
= TREE_CHAIN (elements
);
8417 elem
= build_int_cst (TREE_TYPE (type
), -1);
8418 list
= tree_cons (NULL_TREE
, elem
, list
);
8421 return build_vector (type
, nreverse (list
));
8426 case TRUTH_NOT_EXPR
:
8427 /* The argument to invert_truthvalue must have Boolean type. */
8428 if (TREE_CODE (TREE_TYPE (arg0
)) != BOOLEAN_TYPE
)
8429 arg0
= fold_convert (boolean_type_node
, arg0
);
8431 /* Note that the operand of this must be an int
8432 and its values must be 0 or 1.
8433 ("true" is a fixed value perhaps depending on the language,
8434 but we don't handle values other than 1 correctly yet.) */
8435 tem
= fold_truth_not_expr (arg0
);
8438 return fold_convert (type
, tem
);
8441 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
8442 return fold_convert (type
, arg0
);
8443 if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
8444 return omit_one_operand (type
, TREE_OPERAND (arg0
, 0),
8445 TREE_OPERAND (arg0
, 1));
8446 if (TREE_CODE (arg0
) == COMPLEX_CST
)
8447 return fold_convert (type
, TREE_REALPART (arg0
));
8448 if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
8450 tree itype
= TREE_TYPE (TREE_TYPE (arg0
));
8451 tem
= fold_build2 (TREE_CODE (arg0
), itype
,
8452 fold_build1 (REALPART_EXPR
, itype
,
8453 TREE_OPERAND (arg0
, 0)),
8454 fold_build1 (REALPART_EXPR
, itype
,
8455 TREE_OPERAND (arg0
, 1)));
8456 return fold_convert (type
, tem
);
8458 if (TREE_CODE (arg0
) == CONJ_EXPR
)
8460 tree itype
= TREE_TYPE (TREE_TYPE (arg0
));
8461 tem
= fold_build1 (REALPART_EXPR
, itype
, TREE_OPERAND (arg0
, 0));
8462 return fold_convert (type
, tem
);
8464 if (TREE_CODE (arg0
) == CALL_EXPR
)
8466 tree fn
= get_callee_fndecl (arg0
);
8467 if (DECL_BUILT_IN_CLASS (fn
) == BUILT_IN_NORMAL
)
8468 switch (DECL_FUNCTION_CODE (fn
))
8470 CASE_FLT_FN (BUILT_IN_CEXPI
):
8471 fn
= mathfn_built_in (type
, BUILT_IN_COS
);
8473 return build_call_expr (fn
, 1, CALL_EXPR_ARG (arg0
, 0));
8483 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
8484 return fold_convert (type
, integer_zero_node
);
8485 if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
8486 return omit_one_operand (type
, TREE_OPERAND (arg0
, 1),
8487 TREE_OPERAND (arg0
, 0));
8488 if (TREE_CODE (arg0
) == COMPLEX_CST
)
8489 return fold_convert (type
, TREE_IMAGPART (arg0
));
8490 if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
8492 tree itype
= TREE_TYPE (TREE_TYPE (arg0
));
8493 tem
= fold_build2 (TREE_CODE (arg0
), itype
,
8494 fold_build1 (IMAGPART_EXPR
, itype
,
8495 TREE_OPERAND (arg0
, 0)),
8496 fold_build1 (IMAGPART_EXPR
, itype
,
8497 TREE_OPERAND (arg0
, 1)));
8498 return fold_convert (type
, tem
);
8500 if (TREE_CODE (arg0
) == CONJ_EXPR
)
8502 tree itype
= TREE_TYPE (TREE_TYPE (arg0
));
8503 tem
= fold_build1 (IMAGPART_EXPR
, itype
, TREE_OPERAND (arg0
, 0));
8504 return fold_convert (type
, negate_expr (tem
));
8506 if (TREE_CODE (arg0
) == CALL_EXPR
)
8508 tree fn
= get_callee_fndecl (arg0
);
8509 if (DECL_BUILT_IN_CLASS (fn
) == BUILT_IN_NORMAL
)
8510 switch (DECL_FUNCTION_CODE (fn
))
8512 CASE_FLT_FN (BUILT_IN_CEXPI
):
8513 fn
= mathfn_built_in (type
, BUILT_IN_SIN
);
8515 return build_call_expr (fn
, 1, CALL_EXPR_ARG (arg0
, 0));
8526 } /* switch (code) */
8529 /* Fold a binary expression of code CODE and type TYPE with operands
8530 OP0 and OP1, containing either a MIN-MAX or a MAX-MIN combination.
8531 Return the folded expression if folding is successful. Otherwise,
8532 return NULL_TREE. */
8535 fold_minmax (enum tree_code code
, tree type
, tree op0
, tree op1
)
8537 enum tree_code compl_code
;
8539 if (code
== MIN_EXPR
)
8540 compl_code
= MAX_EXPR
;
8541 else if (code
== MAX_EXPR
)
8542 compl_code
= MIN_EXPR
;
8546 /* MIN (MAX (a, b), b) == b. */
8547 if (TREE_CODE (op0
) == compl_code
8548 && operand_equal_p (TREE_OPERAND (op0
, 1), op1
, 0))
8549 return omit_one_operand (type
, op1
, TREE_OPERAND (op0
, 0));
8551 /* MIN (MAX (b, a), b) == b. */
8552 if (TREE_CODE (op0
) == compl_code
8553 && operand_equal_p (TREE_OPERAND (op0
, 0), op1
, 0)
8554 && reorder_operands_p (TREE_OPERAND (op0
, 1), op1
))
8555 return omit_one_operand (type
, op1
, TREE_OPERAND (op0
, 1));
8557 /* MIN (a, MAX (a, b)) == a. */
8558 if (TREE_CODE (op1
) == compl_code
8559 && operand_equal_p (op0
, TREE_OPERAND (op1
, 0), 0)
8560 && reorder_operands_p (op0
, TREE_OPERAND (op1
, 1)))
8561 return omit_one_operand (type
, op0
, TREE_OPERAND (op1
, 1));
8563 /* MIN (a, MAX (b, a)) == a. */
8564 if (TREE_CODE (op1
) == compl_code
8565 && operand_equal_p (op0
, TREE_OPERAND (op1
, 1), 0)
8566 && reorder_operands_p (op0
, TREE_OPERAND (op1
, 0)))
8567 return omit_one_operand (type
, op0
, TREE_OPERAND (op1
, 0));
8572 /* Helper that tries to canonicalize the comparison ARG0 CODE ARG1
8573 by changing CODE to reduce the magnitude of constants involved in
8574 ARG0 of the comparison.
8575 Returns a canonicalized comparison tree if a simplification was
8576 possible, otherwise returns NULL_TREE.
8577 Set *STRICT_OVERFLOW_P to true if the canonicalization is only
8578 valid if signed overflow is undefined. */
8581 maybe_canonicalize_comparison_1 (enum tree_code code
, tree type
,
8582 tree arg0
, tree arg1
,
8583 bool *strict_overflow_p
)
8585 enum tree_code code0
= TREE_CODE (arg0
);
8586 tree t
, cst0
= NULL_TREE
;
8590 /* Match A +- CST code arg1 and CST code arg1. */
8591 if (!(((code0
== MINUS_EXPR
8592 || code0
== PLUS_EXPR
)
8593 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
8594 || code0
== INTEGER_CST
))
8597 /* Identify the constant in arg0 and its sign. */
8598 if (code0
== INTEGER_CST
)
8601 cst0
= TREE_OPERAND (arg0
, 1);
8602 sgn0
= tree_int_cst_sgn (cst0
);
8604 /* Overflowed constants and zero will cause problems. */
8605 if (integer_zerop (cst0
)
8606 || TREE_OVERFLOW (cst0
))
8609 /* See if we can reduce the magnitude of the constant in
8610 arg0 by changing the comparison code. */
8611 if (code0
== INTEGER_CST
)
8613 /* CST <= arg1 -> CST-1 < arg1. */
8614 if (code
== LE_EXPR
&& sgn0
== 1)
8616 /* -CST < arg1 -> -CST-1 <= arg1. */
8617 else if (code
== LT_EXPR
&& sgn0
== -1)
8619 /* CST > arg1 -> CST-1 >= arg1. */
8620 else if (code
== GT_EXPR
&& sgn0
== 1)
8622 /* -CST >= arg1 -> -CST-1 > arg1. */
8623 else if (code
== GE_EXPR
&& sgn0
== -1)
8627 /* arg1 code' CST' might be more canonical. */
8632 /* A - CST < arg1 -> A - CST-1 <= arg1. */
8634 && code0
== ((sgn0
== -1) ? PLUS_EXPR
: MINUS_EXPR
))
8636 /* A + CST > arg1 -> A + CST-1 >= arg1. */
8637 else if (code
== GT_EXPR
8638 && code0
== ((sgn0
== -1) ? MINUS_EXPR
: PLUS_EXPR
))
8640 /* A + CST <= arg1 -> A + CST-1 < arg1. */
8641 else if (code
== LE_EXPR
8642 && code0
== ((sgn0
== -1) ? MINUS_EXPR
: PLUS_EXPR
))
8644 /* A - CST >= arg1 -> A - CST-1 > arg1. */
8645 else if (code
== GE_EXPR
8646 && code0
== ((sgn0
== -1) ? PLUS_EXPR
: MINUS_EXPR
))
8650 *strict_overflow_p
= true;
8653 /* Now build the constant reduced in magnitude. */
8654 t
= int_const_binop (sgn0
== -1 ? PLUS_EXPR
: MINUS_EXPR
,
8655 cst0
, build_int_cst (TREE_TYPE (cst0
), 1), 0);
8656 if (code0
!= INTEGER_CST
)
8657 t
= fold_build2 (code0
, TREE_TYPE (arg0
), TREE_OPERAND (arg0
, 0), t
);
8659 /* If swapping might yield to a more canonical form, do so. */
8661 return fold_build2 (swap_tree_comparison (code
), type
, arg1
, t
);
8663 return fold_build2 (code
, type
, t
, arg1
);
8666 /* Canonicalize the comparison ARG0 CODE ARG1 with type TYPE with undefined
8667 overflow further. Try to decrease the magnitude of constants involved
8668 by changing LE_EXPR and GE_EXPR to LT_EXPR and GT_EXPR or vice versa
8669 and put sole constants at the second argument position.
8670 Returns the canonicalized tree if changed, otherwise NULL_TREE. */
8673 maybe_canonicalize_comparison (enum tree_code code
, tree type
,
8674 tree arg0
, tree arg1
)
8677 bool strict_overflow_p
;
8678 const char * const warnmsg
= G_("assuming signed overflow does not occur "
8679 "when reducing constant in comparison");
8681 /* In principle pointers also have undefined overflow behavior,
8682 but that causes problems elsewhere. */
8683 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0
))
8684 || POINTER_TYPE_P (TREE_TYPE (arg0
)))
8687 /* Try canonicalization by simplifying arg0. */
8688 strict_overflow_p
= false;
8689 t
= maybe_canonicalize_comparison_1 (code
, type
, arg0
, arg1
,
8690 &strict_overflow_p
);
8693 if (strict_overflow_p
)
8694 fold_overflow_warning (warnmsg
, WARN_STRICT_OVERFLOW_MAGNITUDE
);
8698 /* Try canonicalization by simplifying arg1 using the swapped
8700 code
= swap_tree_comparison (code
);
8701 strict_overflow_p
= false;
8702 t
= maybe_canonicalize_comparison_1 (code
, type
, arg1
, arg0
,
8703 &strict_overflow_p
);
8704 if (t
&& strict_overflow_p
)
8705 fold_overflow_warning (warnmsg
, WARN_STRICT_OVERFLOW_MAGNITUDE
);
8709 /* Subroutine of fold_binary. This routine performs all of the
8710 transformations that are common to the equality/inequality
8711 operators (EQ_EXPR and NE_EXPR) and the ordering operators
8712 (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
8713 fold_binary should call fold_binary. Fold a comparison with
8714 tree code CODE and type TYPE with operands OP0 and OP1. Return
8715 the folded comparison or NULL_TREE. */
8718 fold_comparison (enum tree_code code
, tree type
, tree op0
, tree op1
)
8720 tree arg0
, arg1
, tem
;
8725 STRIP_SIGN_NOPS (arg0
);
8726 STRIP_SIGN_NOPS (arg1
);
8728 tem
= fold_relational_const (code
, type
, arg0
, arg1
);
8729 if (tem
!= NULL_TREE
)
8732 /* If one arg is a real or integer constant, put it last. */
8733 if (tree_swap_operands_p (arg0
, arg1
, true))
8734 return fold_build2 (swap_tree_comparison (code
), type
, op1
, op0
);
8736 /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */
8737 if ((TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
8738 && (TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
8739 && !TREE_OVERFLOW (TREE_OPERAND (arg0
, 1))
8740 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1
)))
8741 && (TREE_CODE (arg1
) == INTEGER_CST
8742 && !TREE_OVERFLOW (arg1
)))
8744 tree const1
= TREE_OPERAND (arg0
, 1);
8746 tree variable
= TREE_OPERAND (arg0
, 0);
8749 lhs_add
= TREE_CODE (arg0
) != PLUS_EXPR
;
8751 lhs
= fold_build2 (lhs_add
? PLUS_EXPR
: MINUS_EXPR
,
8752 TREE_TYPE (arg1
), const2
, const1
);
8754 /* If the constant operation overflowed this can be
8755 simplified as a comparison against INT_MAX/INT_MIN. */
8756 if (TREE_CODE (lhs
) == INTEGER_CST
8757 && TREE_OVERFLOW (lhs
))
8759 int const1_sgn
= tree_int_cst_sgn (const1
);
8760 enum tree_code code2
= code
;
8762 /* Get the sign of the constant on the lhs if the
8763 operation were VARIABLE + CONST1. */
8764 if (TREE_CODE (arg0
) == MINUS_EXPR
)
8765 const1_sgn
= -const1_sgn
;
8767 /* The sign of the constant determines if we overflowed
8768 INT_MAX (const1_sgn == -1) or INT_MIN (const1_sgn == 1).
8769 Canonicalize to the INT_MIN overflow by swapping the comparison
8771 if (const1_sgn
== -1)
8772 code2
= swap_tree_comparison (code
);
8774 /* We now can look at the canonicalized case
8775 VARIABLE + 1 CODE2 INT_MIN
8776 and decide on the result. */
8777 if (code2
== LT_EXPR
8779 || code2
== EQ_EXPR
)
8780 return omit_one_operand (type
, boolean_false_node
, variable
);
8781 else if (code2
== NE_EXPR
8783 || code2
== GT_EXPR
)
8784 return omit_one_operand (type
, boolean_true_node
, variable
);
8787 if (TREE_CODE (lhs
) == TREE_CODE (arg1
)
8788 && (TREE_CODE (lhs
) != INTEGER_CST
8789 || !TREE_OVERFLOW (lhs
)))
8791 fold_overflow_warning (("assuming signed overflow does not occur "
8792 "when changing X +- C1 cmp C2 to "
8794 WARN_STRICT_OVERFLOW_COMPARISON
);
8795 return fold_build2 (code
, type
, variable
, lhs
);
8799 /* For comparisons of pointers we can decompose it to a compile time
8800 comparison of the base objects and the offsets into the object.
8801 This requires at least one operand being an ADDR_EXPR to do more
8802 than the operand_equal_p test below. */
8803 if (POINTER_TYPE_P (TREE_TYPE (arg0
))
8804 && (TREE_CODE (arg0
) == ADDR_EXPR
8805 || TREE_CODE (arg1
) == ADDR_EXPR
))
8807 tree base0
, base1
, offset0
= NULL_TREE
, offset1
= NULL_TREE
;
8808 HOST_WIDE_INT bitsize
, bitpos0
= 0, bitpos1
= 0;
8809 enum machine_mode mode
;
8810 int volatilep
, unsignedp
;
8811 bool indirect_base0
= false;
8813 /* Get base and offset for the access. Strip ADDR_EXPR for
8814 get_inner_reference, but put it back by stripping INDIRECT_REF
8815 off the base object if possible. */
8817 if (TREE_CODE (arg0
) == ADDR_EXPR
)
8819 base0
= get_inner_reference (TREE_OPERAND (arg0
, 0),
8820 &bitsize
, &bitpos0
, &offset0
, &mode
,
8821 &unsignedp
, &volatilep
, false);
8822 if (TREE_CODE (base0
) == INDIRECT_REF
)
8823 base0
= TREE_OPERAND (base0
, 0);
8825 indirect_base0
= true;
8829 if (TREE_CODE (arg1
) == ADDR_EXPR
)
8831 base1
= get_inner_reference (TREE_OPERAND (arg1
, 0),
8832 &bitsize
, &bitpos1
, &offset1
, &mode
,
8833 &unsignedp
, &volatilep
, false);
8834 /* We have to make sure to have an indirect/non-indirect base1
8835 just the same as we did for base0. */
8836 if (TREE_CODE (base1
) == INDIRECT_REF
8838 base1
= TREE_OPERAND (base1
, 0);
8839 else if (!indirect_base0
)
8842 else if (indirect_base0
)
8845 /* If we have equivalent bases we might be able to simplify. */
8847 && operand_equal_p (base0
, base1
, 0))
8849 /* We can fold this expression to a constant if the non-constant
8850 offset parts are equal. */
8851 if (offset0
== offset1
8852 || (offset0
&& offset1
8853 && operand_equal_p (offset0
, offset1
, 0)))
8858 return build_int_cst (boolean_type_node
, bitpos0
== bitpos1
);
8860 return build_int_cst (boolean_type_node
, bitpos0
!= bitpos1
);
8862 return build_int_cst (boolean_type_node
, bitpos0
< bitpos1
);
8864 return build_int_cst (boolean_type_node
, bitpos0
<= bitpos1
);
8866 return build_int_cst (boolean_type_node
, bitpos0
>= bitpos1
);
8868 return build_int_cst (boolean_type_node
, bitpos0
> bitpos1
);
8872 /* We can simplify the comparison to a comparison of the variable
8873 offset parts if the constant offset parts are equal.
8874 Be careful to use signed size type here because otherwise we
8875 mess with array offsets in the wrong way. This is possible
8876 because pointer arithmetic is restricted to retain within an
8877 object and overflow on pointer differences is undefined as of
8878 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */
8879 else if (bitpos0
== bitpos1
)
8881 tree signed_size_type_node
;
8882 signed_size_type_node
= signed_type_for (size_type_node
);
8884 /* By converting to signed size type we cover middle-end pointer
8885 arithmetic which operates on unsigned pointer types of size
8886 type size and ARRAY_REF offsets which are properly sign or
8887 zero extended from their type in case it is narrower than
8889 if (offset0
== NULL_TREE
)
8890 offset0
= build_int_cst (signed_size_type_node
, 0);
8892 offset0
= fold_convert (signed_size_type_node
, offset0
);
8893 if (offset1
== NULL_TREE
)
8894 offset1
= build_int_cst (signed_size_type_node
, 0);
8896 offset1
= fold_convert (signed_size_type_node
, offset1
);
8898 return fold_build2 (code
, type
, offset0
, offset1
);
8903 /* If this is a comparison of two exprs that look like an ARRAY_REF of the
8904 same object, then we can fold this to a comparison of the two offsets in
8905 signed size type. This is possible because pointer arithmetic is
8906 restricted to retain within an object and overflow on pointer differences
8907 is undefined as of 6.5.6/8 and /9 with respect to the signed ptrdiff_t.
8909 We check flag_wrapv directly because pointers types are unsigned,
8910 and therefore TYPE_OVERFLOW_WRAPS returns true for them. That is
8911 normally what we want to avoid certain odd overflow cases, but
8913 if (POINTER_TYPE_P (TREE_TYPE (arg0
))
8915 && !TYPE_OVERFLOW_TRAPS (TREE_TYPE (arg0
)))
8917 tree base0
, offset0
, base1
, offset1
;
8919 if (extract_array_ref (arg0
, &base0
, &offset0
)
8920 && extract_array_ref (arg1
, &base1
, &offset1
)
8921 && operand_equal_p (base0
, base1
, 0))
8923 tree signed_size_type_node
;
8924 signed_size_type_node
= signed_type_for (size_type_node
);
8926 /* By converting to signed size type we cover middle-end pointer
8927 arithmetic which operates on unsigned pointer types of size
8928 type size and ARRAY_REF offsets which are properly sign or
8929 zero extended from their type in case it is narrower than
8931 if (offset0
== NULL_TREE
)
8932 offset0
= build_int_cst (signed_size_type_node
, 0);
8934 offset0
= fold_convert (signed_size_type_node
, offset0
);
8935 if (offset1
== NULL_TREE
)
8936 offset1
= build_int_cst (signed_size_type_node
, 0);
8938 offset1
= fold_convert (signed_size_type_node
, offset1
);
8940 return fold_build2 (code
, type
, offset0
, offset1
);
8944 /* Transform comparisons of the form X +- C1 CMP Y +- C2 to
8945 X CMP Y +- C2 +- C1 for signed X, Y. This is valid if
8946 the resulting offset is smaller in absolute value than the
8948 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0
))
8949 && (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
8950 && (TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
8951 && !TREE_OVERFLOW (TREE_OPERAND (arg0
, 1)))
8952 && (TREE_CODE (arg1
) == PLUS_EXPR
|| TREE_CODE (arg1
) == MINUS_EXPR
)
8953 && (TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
8954 && !TREE_OVERFLOW (TREE_OPERAND (arg1
, 1))))
8956 tree const1
= TREE_OPERAND (arg0
, 1);
8957 tree const2
= TREE_OPERAND (arg1
, 1);
8958 tree variable1
= TREE_OPERAND (arg0
, 0);
8959 tree variable2
= TREE_OPERAND (arg1
, 0);
8961 const char * const warnmsg
= G_("assuming signed overflow does not "
8962 "occur when combining constants around "
8965 /* Put the constant on the side where it doesn't overflow and is
8966 of lower absolute value than before. */
8967 cst
= int_const_binop (TREE_CODE (arg0
) == TREE_CODE (arg1
)
8968 ? MINUS_EXPR
: PLUS_EXPR
,
8970 if (!TREE_OVERFLOW (cst
)
8971 && tree_int_cst_compare (const2
, cst
) == tree_int_cst_sgn (const2
))
8973 fold_overflow_warning (warnmsg
, WARN_STRICT_OVERFLOW_COMPARISON
);
8974 return fold_build2 (code
, type
,
8976 fold_build2 (TREE_CODE (arg1
), TREE_TYPE (arg1
),
8980 cst
= int_const_binop (TREE_CODE (arg0
) == TREE_CODE (arg1
)
8981 ? MINUS_EXPR
: PLUS_EXPR
,
8983 if (!TREE_OVERFLOW (cst
)
8984 && tree_int_cst_compare (const1
, cst
) == tree_int_cst_sgn (const1
))
8986 fold_overflow_warning (warnmsg
, WARN_STRICT_OVERFLOW_COMPARISON
);
8987 return fold_build2 (code
, type
,
8988 fold_build2 (TREE_CODE (arg0
), TREE_TYPE (arg0
),
8994 /* Transform comparisons of the form X * C1 CMP 0 to X CMP 0 in the
8995 signed arithmetic case. That form is created by the compiler
8996 often enough for folding it to be of value. One example is in
8997 computing loop trip counts after Operator Strength Reduction. */
8998 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0
))
8999 && TREE_CODE (arg0
) == MULT_EXPR
9000 && (TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
9001 && !TREE_OVERFLOW (TREE_OPERAND (arg0
, 1)))
9002 && integer_zerop (arg1
))
9004 tree const1
= TREE_OPERAND (arg0
, 1);
9005 tree const2
= arg1
; /* zero */
9006 tree variable1
= TREE_OPERAND (arg0
, 0);
9007 enum tree_code cmp_code
= code
;
9009 gcc_assert (!integer_zerop (const1
));
9011 fold_overflow_warning (("assuming signed overflow does not occur when "
9012 "eliminating multiplication in comparison "
9014 WARN_STRICT_OVERFLOW_COMPARISON
);
9016 /* If const1 is negative we swap the sense of the comparison. */
9017 if (tree_int_cst_sgn (const1
) < 0)
9018 cmp_code
= swap_tree_comparison (cmp_code
);
9020 return fold_build2 (cmp_code
, type
, variable1
, const2
);
9023 tem
= maybe_canonicalize_comparison (code
, type
, op0
, op1
);
9027 if (FLOAT_TYPE_P (TREE_TYPE (arg0
)))
9029 tree targ0
= strip_float_extensions (arg0
);
9030 tree targ1
= strip_float_extensions (arg1
);
9031 tree newtype
= TREE_TYPE (targ0
);
9033 if (TYPE_PRECISION (TREE_TYPE (targ1
)) > TYPE_PRECISION (newtype
))
9034 newtype
= TREE_TYPE (targ1
);
9036 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
9037 if (TYPE_PRECISION (newtype
) < TYPE_PRECISION (TREE_TYPE (arg0
)))
9038 return fold_build2 (code
, type
, fold_convert (newtype
, targ0
),
9039 fold_convert (newtype
, targ1
));
9041 /* (-a) CMP (-b) -> b CMP a */
9042 if (TREE_CODE (arg0
) == NEGATE_EXPR
9043 && TREE_CODE (arg1
) == NEGATE_EXPR
)
9044 return fold_build2 (code
, type
, TREE_OPERAND (arg1
, 0),
9045 TREE_OPERAND (arg0
, 0));
9047 if (TREE_CODE (arg1
) == REAL_CST
)
9049 REAL_VALUE_TYPE cst
;
9050 cst
= TREE_REAL_CST (arg1
);
9052 /* (-a) CMP CST -> a swap(CMP) (-CST) */
9053 if (TREE_CODE (arg0
) == NEGATE_EXPR
)
9054 return fold_build2 (swap_tree_comparison (code
), type
,
9055 TREE_OPERAND (arg0
, 0),
9056 build_real (TREE_TYPE (arg1
),
9057 REAL_VALUE_NEGATE (cst
)));
9059 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
9060 /* a CMP (-0) -> a CMP 0 */
9061 if (REAL_VALUE_MINUS_ZERO (cst
))
9062 return fold_build2 (code
, type
, arg0
,
9063 build_real (TREE_TYPE (arg1
), dconst0
));
9065 /* x != NaN is always true, other ops are always false. */
9066 if (REAL_VALUE_ISNAN (cst
)
9067 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1
))))
9069 tem
= (code
== NE_EXPR
) ? integer_one_node
: integer_zero_node
;
9070 return omit_one_operand (type
, tem
, arg0
);
9073 /* Fold comparisons against infinity. */
9074 if (REAL_VALUE_ISINF (cst
))
9076 tem
= fold_inf_compare (code
, type
, arg0
, arg1
);
9077 if (tem
!= NULL_TREE
)
9082 /* If this is a comparison of a real constant with a PLUS_EXPR
9083 or a MINUS_EXPR of a real constant, we can convert it into a
9084 comparison with a revised real constant as long as no overflow
9085 occurs when unsafe_math_optimizations are enabled. */
9086 if (flag_unsafe_math_optimizations
9087 && TREE_CODE (arg1
) == REAL_CST
9088 && (TREE_CODE (arg0
) == PLUS_EXPR
9089 || TREE_CODE (arg0
) == MINUS_EXPR
)
9090 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == REAL_CST
9091 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
9092 ? MINUS_EXPR
: PLUS_EXPR
,
9093 arg1
, TREE_OPERAND (arg0
, 1), 0))
9094 && !TREE_OVERFLOW (tem
))
9095 return fold_build2 (code
, type
, TREE_OPERAND (arg0
, 0), tem
);
9097 /* Likewise, we can simplify a comparison of a real constant with
9098 a MINUS_EXPR whose first operand is also a real constant, i.e.
9099 (c1 - x) < c2 becomes x > c1-c2. */
9100 if (flag_unsafe_math_optimizations
9101 && TREE_CODE (arg1
) == REAL_CST
9102 && TREE_CODE (arg0
) == MINUS_EXPR
9103 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == REAL_CST
9104 && 0 != (tem
= const_binop (MINUS_EXPR
, TREE_OPERAND (arg0
, 0),
9106 && !TREE_OVERFLOW (tem
))
9107 return fold_build2 (swap_tree_comparison (code
), type
,
9108 TREE_OPERAND (arg0
, 1), tem
);
9110 /* Fold comparisons against built-in math functions. */
9111 if (TREE_CODE (arg1
) == REAL_CST
9112 && flag_unsafe_math_optimizations
9113 && ! flag_errno_math
)
9115 enum built_in_function fcode
= builtin_mathfn_code (arg0
);
9117 if (fcode
!= END_BUILTINS
)
9119 tem
= fold_mathfn_compare (fcode
, code
, type
, arg0
, arg1
);
9120 if (tem
!= NULL_TREE
)
9126 if (TREE_CODE (TREE_TYPE (arg0
)) == INTEGER_TYPE
9127 && (TREE_CODE (arg0
) == NOP_EXPR
9128 || TREE_CODE (arg0
) == CONVERT_EXPR
))
9130 /* If we are widening one operand of an integer comparison,
9131 see if the other operand is similarly being widened. Perhaps we
9132 can do the comparison in the narrower type. */
9133 tem
= fold_widened_comparison (code
, type
, arg0
, arg1
);
9137 /* Or if we are changing signedness. */
9138 tem
= fold_sign_changed_comparison (code
, type
, arg0
, arg1
);
9143 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
9144 constant, we can simplify it. */
9145 if (TREE_CODE (arg1
) == INTEGER_CST
9146 && (TREE_CODE (arg0
) == MIN_EXPR
9147 || TREE_CODE (arg0
) == MAX_EXPR
)
9148 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
9150 tem
= optimize_minmax_comparison (code
, type
, op0
, op1
);
9155 /* Simplify comparison of something with itself. (For IEEE
9156 floating-point, we can only do some of these simplifications.) */
9157 if (operand_equal_p (arg0
, arg1
, 0))
9162 if (! FLOAT_TYPE_P (TREE_TYPE (arg0
))
9163 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
))))
9164 return constant_boolean_node (1, type
);
9169 if (! FLOAT_TYPE_P (TREE_TYPE (arg0
))
9170 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
))))
9171 return constant_boolean_node (1, type
);
9172 return fold_build2 (EQ_EXPR
, type
, arg0
, arg1
);
9175 /* For NE, we can only do this simplification if integer
9176 or we don't honor IEEE floating point NaNs. */
9177 if (FLOAT_TYPE_P (TREE_TYPE (arg0
))
9178 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
))))
9180 /* ... fall through ... */
9183 return constant_boolean_node (0, type
);
9189 /* If we are comparing an expression that just has comparisons
9190 of two integer values, arithmetic expressions of those comparisons,
9191 and constants, we can simplify it. There are only three cases
9192 to check: the two values can either be equal, the first can be
9193 greater, or the second can be greater. Fold the expression for
9194 those three values. Since each value must be 0 or 1, we have
9195 eight possibilities, each of which corresponds to the constant 0
9196 or 1 or one of the six possible comparisons.
9198 This handles common cases like (a > b) == 0 but also handles
9199 expressions like ((x > y) - (y > x)) > 0, which supposedly
9200 occur in macroized code. */
9202 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) != INTEGER_CST
)
9204 tree cval1
= 0, cval2
= 0;
9207 if (twoval_comparison_p (arg0
, &cval1
, &cval2
, &save_p
)
9208 /* Don't handle degenerate cases here; they should already
9209 have been handled anyway. */
9210 && cval1
!= 0 && cval2
!= 0
9211 && ! (TREE_CONSTANT (cval1
) && TREE_CONSTANT (cval2
))
9212 && TREE_TYPE (cval1
) == TREE_TYPE (cval2
)
9213 && INTEGRAL_TYPE_P (TREE_TYPE (cval1
))
9214 && TYPE_MAX_VALUE (TREE_TYPE (cval1
))
9215 && TYPE_MAX_VALUE (TREE_TYPE (cval2
))
9216 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1
)),
9217 TYPE_MAX_VALUE (TREE_TYPE (cval2
)), 0))
9219 tree maxval
= TYPE_MAX_VALUE (TREE_TYPE (cval1
));
9220 tree minval
= TYPE_MIN_VALUE (TREE_TYPE (cval1
));
9222 /* We can't just pass T to eval_subst in case cval1 or cval2
9223 was the same as ARG1. */
9226 = fold_build2 (code
, type
,
9227 eval_subst (arg0
, cval1
, maxval
,
9231 = fold_build2 (code
, type
,
9232 eval_subst (arg0
, cval1
, maxval
,
9236 = fold_build2 (code
, type
,
9237 eval_subst (arg0
, cval1
, minval
,
9241 /* All three of these results should be 0 or 1. Confirm they are.
9242 Then use those values to select the proper code to use. */
9244 if (TREE_CODE (high_result
) == INTEGER_CST
9245 && TREE_CODE (equal_result
) == INTEGER_CST
9246 && TREE_CODE (low_result
) == INTEGER_CST
)
9248 /* Make a 3-bit mask with the high-order bit being the
9249 value for `>', the next for '=', and the low for '<'. */
9250 switch ((integer_onep (high_result
) * 4)
9251 + (integer_onep (equal_result
) * 2)
9252 + integer_onep (low_result
))
9256 return omit_one_operand (type
, integer_zero_node
, arg0
);
9277 return omit_one_operand (type
, integer_one_node
, arg0
);
9281 return save_expr (build2 (code
, type
, cval1
, cval2
));
9282 return fold_build2 (code
, type
, cval1
, cval2
);
9287 /* Fold a comparison of the address of COMPONENT_REFs with the same
9288 type and component to a comparison of the address of the base
9289 object. In short, &x->a OP &y->a to x OP y and
9290 &x->a OP &y.a to x OP &y */
9291 if (TREE_CODE (arg0
) == ADDR_EXPR
9292 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == COMPONENT_REF
9293 && TREE_CODE (arg1
) == ADDR_EXPR
9294 && TREE_CODE (TREE_OPERAND (arg1
, 0)) == COMPONENT_REF
)
9296 tree cref0
= TREE_OPERAND (arg0
, 0);
9297 tree cref1
= TREE_OPERAND (arg1
, 0);
9298 if (TREE_OPERAND (cref0
, 1) == TREE_OPERAND (cref1
, 1))
9300 tree op0
= TREE_OPERAND (cref0
, 0);
9301 tree op1
= TREE_OPERAND (cref1
, 0);
9302 return fold_build2 (code
, type
,
9303 fold_addr_expr (op0
),
9304 fold_addr_expr (op1
));
9308 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
9309 into a single range test. */
9310 if ((TREE_CODE (arg0
) == TRUNC_DIV_EXPR
9311 || TREE_CODE (arg0
) == EXACT_DIV_EXPR
)
9312 && TREE_CODE (arg1
) == INTEGER_CST
9313 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
9314 && !integer_zerop (TREE_OPERAND (arg0
, 1))
9315 && !TREE_OVERFLOW (TREE_OPERAND (arg0
, 1))
9316 && !TREE_OVERFLOW (arg1
))
9318 tem
= fold_div_compare (code
, type
, arg0
, arg1
);
9319 if (tem
!= NULL_TREE
)
9323 /* Fold ~X op ~Y as Y op X. */
9324 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
9325 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
9327 tree cmp_type
= TREE_TYPE (TREE_OPERAND (arg0
, 0));
9328 return fold_build2 (code
, type
,
9329 fold_convert (cmp_type
, TREE_OPERAND (arg1
, 0)),
9330 TREE_OPERAND (arg0
, 0));
9333 /* Fold ~X op C as X op' ~C, where op' is the swapped comparison. */
9334 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
9335 && TREE_CODE (arg1
) == INTEGER_CST
)
9337 tree cmp_type
= TREE_TYPE (TREE_OPERAND (arg0
, 0));
9338 return fold_build2 (swap_tree_comparison (code
), type
,
9339 TREE_OPERAND (arg0
, 0),
9340 fold_build1 (BIT_NOT_EXPR
, cmp_type
,
9341 fold_convert (cmp_type
, arg1
)));
9348 /* Subroutine of fold_binary. Optimize complex multiplications of the
9349 form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
9350 argument EXPR represents the expression "z" of type TYPE. */
9353 fold_mult_zconjz (tree type
, tree expr
)
9355 tree itype
= TREE_TYPE (type
);
9356 tree rpart
, ipart
, tem
;
9358 if (TREE_CODE (expr
) == COMPLEX_EXPR
)
9360 rpart
= TREE_OPERAND (expr
, 0);
9361 ipart
= TREE_OPERAND (expr
, 1);
9363 else if (TREE_CODE (expr
) == COMPLEX_CST
)
9365 rpart
= TREE_REALPART (expr
);
9366 ipart
= TREE_IMAGPART (expr
);
9370 expr
= save_expr (expr
);
9371 rpart
= fold_build1 (REALPART_EXPR
, itype
, expr
);
9372 ipart
= fold_build1 (IMAGPART_EXPR
, itype
, expr
);
9375 rpart
= save_expr (rpart
);
9376 ipart
= save_expr (ipart
);
9377 tem
= fold_build2 (PLUS_EXPR
, itype
,
9378 fold_build2 (MULT_EXPR
, itype
, rpart
, rpart
),
9379 fold_build2 (MULT_EXPR
, itype
, ipart
, ipart
));
9380 return fold_build2 (COMPLEX_EXPR
, type
, tem
,
9381 fold_convert (itype
, integer_zero_node
));
9385 /* Fold a binary expression of code CODE and type TYPE with operands
9386 OP0 and OP1. Return the folded expression if folding is
9387 successful. Otherwise, return NULL_TREE. */
9390 fold_binary (enum tree_code code
, tree type
, tree op0
, tree op1
)
9392 enum tree_code_class kind
= TREE_CODE_CLASS (code
);
9393 tree arg0
, arg1
, tem
;
9394 tree t1
= NULL_TREE
;
9395 bool strict_overflow_p
;
9397 gcc_assert ((IS_EXPR_CODE_CLASS (kind
)
9398 || IS_GIMPLE_STMT_CODE_CLASS (kind
))
9399 && TREE_CODE_LENGTH (code
) == 2
9401 && op1
!= NULL_TREE
);
9406 /* Strip any conversions that don't change the mode. This is
9407 safe for every expression, except for a comparison expression
9408 because its signedness is derived from its operands. So, in
9409 the latter case, only strip conversions that don't change the
9412 Note that this is done as an internal manipulation within the
9413 constant folder, in order to find the simplest representation
9414 of the arguments so that their form can be studied. In any
9415 cases, the appropriate type conversions should be put back in
9416 the tree that will get out of the constant folder. */
9418 if (kind
== tcc_comparison
)
9420 STRIP_SIGN_NOPS (arg0
);
9421 STRIP_SIGN_NOPS (arg1
);
9429 /* Note that TREE_CONSTANT isn't enough: static var addresses are
9430 constant but we can't do arithmetic on them. */
9431 if ((TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
9432 || (TREE_CODE (arg0
) == REAL_CST
&& TREE_CODE (arg1
) == REAL_CST
)
9433 || (TREE_CODE (arg0
) == FIXED_CST
&& TREE_CODE (arg1
) == FIXED_CST
)
9434 || (TREE_CODE (arg0
) == FIXED_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
9435 || (TREE_CODE (arg0
) == COMPLEX_CST
&& TREE_CODE (arg1
) == COMPLEX_CST
)
9436 || (TREE_CODE (arg0
) == VECTOR_CST
&& TREE_CODE (arg1
) == VECTOR_CST
))
9438 if (kind
== tcc_binary
)
9440 /* Make sure type and arg0 have the same saturating flag. */
9441 gcc_assert (TYPE_SATURATING (type
)
9442 == TYPE_SATURATING (TREE_TYPE (arg0
)));
9443 tem
= const_binop (code
, arg0
, arg1
, 0);
9445 else if (kind
== tcc_comparison
)
9446 tem
= fold_relational_const (code
, type
, arg0
, arg1
);
9450 if (tem
!= NULL_TREE
)
9452 if (TREE_TYPE (tem
) != type
)
9453 tem
= fold_convert (type
, tem
);
9458 /* If this is a commutative operation, and ARG0 is a constant, move it
9459 to ARG1 to reduce the number of tests below. */
9460 if (commutative_tree_code (code
)
9461 && tree_swap_operands_p (arg0
, arg1
, true))
9462 return fold_build2 (code
, type
, op1
, op0
);
9464 /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
9466 First check for cases where an arithmetic operation is applied to a
9467 compound, conditional, or comparison operation. Push the arithmetic
9468 operation inside the compound or conditional to see if any folding
9469 can then be done. Convert comparison to conditional for this purpose.
9470 The also optimizes non-constant cases that used to be done in
9473 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
9474 one of the operands is a comparison and the other is a comparison, a
9475 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
9476 code below would make the expression more complex. Change it to a
9477 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
9478 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
9480 if ((code
== BIT_AND_EXPR
|| code
== BIT_IOR_EXPR
9481 || code
== EQ_EXPR
|| code
== NE_EXPR
)
9482 && ((truth_value_p (TREE_CODE (arg0
))
9483 && (truth_value_p (TREE_CODE (arg1
))
9484 || (TREE_CODE (arg1
) == BIT_AND_EXPR
9485 && integer_onep (TREE_OPERAND (arg1
, 1)))))
9486 || (truth_value_p (TREE_CODE (arg1
))
9487 && (truth_value_p (TREE_CODE (arg0
))
9488 || (TREE_CODE (arg0
) == BIT_AND_EXPR
9489 && integer_onep (TREE_OPERAND (arg0
, 1)))))))
9491 tem
= fold_build2 (code
== BIT_AND_EXPR
? TRUTH_AND_EXPR
9492 : code
== BIT_IOR_EXPR
? TRUTH_OR_EXPR
9495 fold_convert (boolean_type_node
, arg0
),
9496 fold_convert (boolean_type_node
, arg1
));
9498 if (code
== EQ_EXPR
)
9499 tem
= invert_truthvalue (tem
);
9501 return fold_convert (type
, tem
);
9504 if (TREE_CODE_CLASS (code
) == tcc_binary
9505 || TREE_CODE_CLASS (code
) == tcc_comparison
)
9507 if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
9508 return build2 (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
9509 fold_build2 (code
, type
,
9510 TREE_OPERAND (arg0
, 1), op1
));
9511 if (TREE_CODE (arg1
) == COMPOUND_EXPR
9512 && reorder_operands_p (arg0
, TREE_OPERAND (arg1
, 0)))
9513 return build2 (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
9514 fold_build2 (code
, type
,
9515 op0
, TREE_OPERAND (arg1
, 1)));
9517 if (TREE_CODE (arg0
) == COND_EXPR
|| COMPARISON_CLASS_P (arg0
))
9519 tem
= fold_binary_op_with_conditional_arg (code
, type
, op0
, op1
,
9521 /*cond_first_p=*/1);
9522 if (tem
!= NULL_TREE
)
9526 if (TREE_CODE (arg1
) == COND_EXPR
|| COMPARISON_CLASS_P (arg1
))
9528 tem
= fold_binary_op_with_conditional_arg (code
, type
, op0
, op1
,
9530 /*cond_first_p=*/0);
9531 if (tem
!= NULL_TREE
)
9538 case POINTER_PLUS_EXPR
:
9539 /* 0 +p index -> (type)index */
9540 if (integer_zerop (arg0
))
9541 return non_lvalue (fold_convert (type
, arg1
));
9543 /* PTR +p 0 -> PTR */
9544 if (integer_zerop (arg1
))
9545 return non_lvalue (fold_convert (type
, arg0
));
9547 /* INT +p INT -> (PTR)(INT + INT). Stripping types allows for this. */
9548 if (INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
9549 && INTEGRAL_TYPE_P (TREE_TYPE (arg0
)))
9550 return fold_convert (type
, fold_build2 (PLUS_EXPR
, sizetype
,
9551 fold_convert (sizetype
, arg1
),
9552 fold_convert (sizetype
, arg0
)));
9554 /* index +p PTR -> PTR +p index */
9555 if (POINTER_TYPE_P (TREE_TYPE (arg1
))
9556 && INTEGRAL_TYPE_P (TREE_TYPE (arg0
)))
9557 return fold_build2 (POINTER_PLUS_EXPR
, type
,
9558 fold_convert (type
, arg1
),
9559 fold_convert (sizetype
, arg0
));
9561 /* (PTR +p B) +p A -> PTR +p (B + A) */
9562 if (TREE_CODE (arg0
) == POINTER_PLUS_EXPR
)
9565 tree arg01
= fold_convert (sizetype
, TREE_OPERAND (arg0
, 1));
9566 tree arg00
= TREE_OPERAND (arg0
, 0);
9567 inner
= fold_build2 (PLUS_EXPR
, sizetype
,
9568 arg01
, fold_convert (sizetype
, arg1
));
9569 return fold_convert (type
,
9570 fold_build2 (POINTER_PLUS_EXPR
,
9571 TREE_TYPE (arg00
), arg00
, inner
));
9574 /* PTR_CST +p CST -> CST1 */
9575 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
9576 return fold_build2 (PLUS_EXPR
, type
, arg0
, fold_convert (type
, arg1
));
9578 /* Try replacing &a[i1] +p c * i2 with &a[i1 + i2], if c is step
9579 of the array. Loop optimizer sometimes produce this type of
9581 if (TREE_CODE (arg0
) == ADDR_EXPR
)
9583 tem
= try_move_mult_to_index (arg0
, fold_convert (sizetype
, arg1
));
9585 return fold_convert (type
, tem
);
9591 /* PTR + INT -> (INT)(PTR p+ INT) */
9592 if (POINTER_TYPE_P (TREE_TYPE (arg0
))
9593 && INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
9594 return fold_convert (type
, fold_build2 (POINTER_PLUS_EXPR
,
9597 fold_convert (sizetype
, arg1
)));
9598 /* INT + PTR -> (INT)(PTR p+ INT) */
9599 if (POINTER_TYPE_P (TREE_TYPE (arg1
))
9600 && INTEGRAL_TYPE_P (TREE_TYPE (arg0
)))
9601 return fold_convert (type
, fold_build2 (POINTER_PLUS_EXPR
,
9604 fold_convert (sizetype
, arg0
)));
9605 /* A + (-B) -> A - B */
9606 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
9607 return fold_build2 (MINUS_EXPR
, type
,
9608 fold_convert (type
, arg0
),
9609 fold_convert (type
, TREE_OPERAND (arg1
, 0)));
9610 /* (-A) + B -> B - A */
9611 if (TREE_CODE (arg0
) == NEGATE_EXPR
9612 && reorder_operands_p (TREE_OPERAND (arg0
, 0), arg1
))
9613 return fold_build2 (MINUS_EXPR
, type
,
9614 fold_convert (type
, arg1
),
9615 fold_convert (type
, TREE_OPERAND (arg0
, 0)));
9617 if (INTEGRAL_TYPE_P (type
))
9619 /* Convert ~A + 1 to -A. */
9620 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
9621 && integer_onep (arg1
))
9622 return fold_build1 (NEGATE_EXPR
, type
, TREE_OPERAND (arg0
, 0));
9625 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
9626 && !TYPE_OVERFLOW_TRAPS (type
))
9628 tree tem
= TREE_OPERAND (arg0
, 0);
9631 if (operand_equal_p (tem
, arg1
, 0))
9633 t1
= build_int_cst_type (type
, -1);
9634 return omit_one_operand (type
, t1
, arg1
);
9639 if (TREE_CODE (arg1
) == BIT_NOT_EXPR
9640 && !TYPE_OVERFLOW_TRAPS (type
))
9642 tree tem
= TREE_OPERAND (arg1
, 0);
9645 if (operand_equal_p (arg0
, tem
, 0))
9647 t1
= build_int_cst_type (type
, -1);
9648 return omit_one_operand (type
, t1
, arg0
);
9653 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
9654 same or one. Make sure type is not saturating. */
9655 if ((TREE_CODE (arg0
) == MULT_EXPR
9656 || TREE_CODE (arg1
) == MULT_EXPR
)
9657 && !TYPE_SATURATING (type
)
9658 && (!FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
))
9660 tree tem
= fold_plusminus_mult_expr (code
, type
, arg0
, arg1
);
9665 if (! FLOAT_TYPE_P (type
))
9667 if (integer_zerop (arg1
))
9668 return non_lvalue (fold_convert (type
, arg0
));
9670 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
9671 with a constant, and the two constants have no bits in common,
9672 we should treat this as a BIT_IOR_EXPR since this may produce more
9674 if (TREE_CODE (arg0
) == BIT_AND_EXPR
9675 && TREE_CODE (arg1
) == BIT_AND_EXPR
9676 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
9677 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
9678 && integer_zerop (const_binop (BIT_AND_EXPR
,
9679 TREE_OPERAND (arg0
, 1),
9680 TREE_OPERAND (arg1
, 1), 0)))
9682 code
= BIT_IOR_EXPR
;
9686 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
9687 (plus (plus (mult) (mult)) (foo)) so that we can
9688 take advantage of the factoring cases below. */
9689 if (((TREE_CODE (arg0
) == PLUS_EXPR
9690 || TREE_CODE (arg0
) == MINUS_EXPR
)
9691 && TREE_CODE (arg1
) == MULT_EXPR
)
9692 || ((TREE_CODE (arg1
) == PLUS_EXPR
9693 || TREE_CODE (arg1
) == MINUS_EXPR
)
9694 && TREE_CODE (arg0
) == MULT_EXPR
))
9696 tree parg0
, parg1
, parg
, marg
;
9697 enum tree_code pcode
;
9699 if (TREE_CODE (arg1
) == MULT_EXPR
)
9700 parg
= arg0
, marg
= arg1
;
9702 parg
= arg1
, marg
= arg0
;
9703 pcode
= TREE_CODE (parg
);
9704 parg0
= TREE_OPERAND (parg
, 0);
9705 parg1
= TREE_OPERAND (parg
, 1);
9709 if (TREE_CODE (parg0
) == MULT_EXPR
9710 && TREE_CODE (parg1
) != MULT_EXPR
)
9711 return fold_build2 (pcode
, type
,
9712 fold_build2 (PLUS_EXPR
, type
,
9713 fold_convert (type
, parg0
),
9714 fold_convert (type
, marg
)),
9715 fold_convert (type
, parg1
));
9716 if (TREE_CODE (parg0
) != MULT_EXPR
9717 && TREE_CODE (parg1
) == MULT_EXPR
)
9718 return fold_build2 (PLUS_EXPR
, type
,
9719 fold_convert (type
, parg0
),
9720 fold_build2 (pcode
, type
,
9721 fold_convert (type
, marg
),
9728 /* See if ARG1 is zero and X + ARG1 reduces to X. */
9729 if (fold_real_zero_addition_p (TREE_TYPE (arg0
), arg1
, 0))
9730 return non_lvalue (fold_convert (type
, arg0
));
9732 /* Likewise if the operands are reversed. */
9733 if (fold_real_zero_addition_p (TREE_TYPE (arg1
), arg0
, 0))
9734 return non_lvalue (fold_convert (type
, arg1
));
9736 /* Convert X + -C into X - C. */
9737 if (TREE_CODE (arg1
) == REAL_CST
9738 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1
)))
9740 tem
= fold_negate_const (arg1
, type
);
9741 if (!TREE_OVERFLOW (arg1
) || !flag_trapping_math
)
9742 return fold_build2 (MINUS_EXPR
, type
,
9743 fold_convert (type
, arg0
),
9744 fold_convert (type
, tem
));
9747 /* Fold __complex__ ( x, 0 ) + __complex__ ( 0, y )
9748 to __complex__ ( x, y ). This is not the same for SNaNs or
9749 if signed zeros are involved. */
9750 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
9751 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0
)))
9752 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0
)))
9754 tree rtype
= TREE_TYPE (TREE_TYPE (arg0
));
9755 tree arg0r
= fold_unary (REALPART_EXPR
, rtype
, arg0
);
9756 tree arg0i
= fold_unary (IMAGPART_EXPR
, rtype
, arg0
);
9757 bool arg0rz
= false, arg0iz
= false;
9758 if ((arg0r
&& (arg0rz
= real_zerop (arg0r
)))
9759 || (arg0i
&& (arg0iz
= real_zerop (arg0i
))))
9761 tree arg1r
= fold_unary (REALPART_EXPR
, rtype
, arg1
);
9762 tree arg1i
= fold_unary (IMAGPART_EXPR
, rtype
, arg1
);
9763 if (arg0rz
&& arg1i
&& real_zerop (arg1i
))
9765 tree rp
= arg1r
? arg1r
9766 : build1 (REALPART_EXPR
, rtype
, arg1
);
9767 tree ip
= arg0i
? arg0i
9768 : build1 (IMAGPART_EXPR
, rtype
, arg0
);
9769 return fold_build2 (COMPLEX_EXPR
, type
, rp
, ip
);
9771 else if (arg0iz
&& arg1r
&& real_zerop (arg1r
))
9773 tree rp
= arg0r
? arg0r
9774 : build1 (REALPART_EXPR
, rtype
, arg0
);
9775 tree ip
= arg1i
? arg1i
9776 : build1 (IMAGPART_EXPR
, rtype
, arg1
);
9777 return fold_build2 (COMPLEX_EXPR
, type
, rp
, ip
);
9782 if (flag_unsafe_math_optimizations
9783 && (TREE_CODE (arg0
) == RDIV_EXPR
|| TREE_CODE (arg0
) == MULT_EXPR
)
9784 && (TREE_CODE (arg1
) == RDIV_EXPR
|| TREE_CODE (arg1
) == MULT_EXPR
)
9785 && (tem
= distribute_real_division (code
, type
, arg0
, arg1
)))
9788 /* Convert x+x into x*2.0. */
9789 if (operand_equal_p (arg0
, arg1
, 0)
9790 && SCALAR_FLOAT_TYPE_P (type
))
9791 return fold_build2 (MULT_EXPR
, type
, arg0
,
9792 build_real (type
, dconst2
));
9794 /* Convert a + (b*c + d*e) into (a + b*c) + d*e. */
9795 if (flag_unsafe_math_optimizations
9796 && TREE_CODE (arg1
) == PLUS_EXPR
9797 && TREE_CODE (arg0
) != MULT_EXPR
)
9799 tree tree10
= TREE_OPERAND (arg1
, 0);
9800 tree tree11
= TREE_OPERAND (arg1
, 1);
9801 if (TREE_CODE (tree11
) == MULT_EXPR
9802 && TREE_CODE (tree10
) == MULT_EXPR
)
9805 tree0
= fold_build2 (PLUS_EXPR
, type
, arg0
, tree10
);
9806 return fold_build2 (PLUS_EXPR
, type
, tree0
, tree11
);
9809 /* Convert (b*c + d*e) + a into b*c + (d*e +a). */
9810 if (flag_unsafe_math_optimizations
9811 && TREE_CODE (arg0
) == PLUS_EXPR
9812 && TREE_CODE (arg1
) != MULT_EXPR
)
9814 tree tree00
= TREE_OPERAND (arg0
, 0);
9815 tree tree01
= TREE_OPERAND (arg0
, 1);
9816 if (TREE_CODE (tree01
) == MULT_EXPR
9817 && TREE_CODE (tree00
) == MULT_EXPR
)
9820 tree0
= fold_build2 (PLUS_EXPR
, type
, tree01
, arg1
);
9821 return fold_build2 (PLUS_EXPR
, type
, tree00
, tree0
);
9827 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
9828 is a rotate of A by C1 bits. */
9829 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
9830 is a rotate of A by B bits. */
9832 enum tree_code code0
, code1
;
9833 code0
= TREE_CODE (arg0
);
9834 code1
= TREE_CODE (arg1
);
9835 if (((code0
== RSHIFT_EXPR
&& code1
== LSHIFT_EXPR
)
9836 || (code1
== RSHIFT_EXPR
&& code0
== LSHIFT_EXPR
))
9837 && operand_equal_p (TREE_OPERAND (arg0
, 0),
9838 TREE_OPERAND (arg1
, 0), 0)
9839 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
9841 tree tree01
, tree11
;
9842 enum tree_code code01
, code11
;
9844 tree01
= TREE_OPERAND (arg0
, 1);
9845 tree11
= TREE_OPERAND (arg1
, 1);
9846 STRIP_NOPS (tree01
);
9847 STRIP_NOPS (tree11
);
9848 code01
= TREE_CODE (tree01
);
9849 code11
= TREE_CODE (tree11
);
9850 if (code01
== INTEGER_CST
9851 && code11
== INTEGER_CST
9852 && TREE_INT_CST_HIGH (tree01
) == 0
9853 && TREE_INT_CST_HIGH (tree11
) == 0
9854 && ((TREE_INT_CST_LOW (tree01
) + TREE_INT_CST_LOW (tree11
))
9855 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)))))
9856 return build2 (LROTATE_EXPR
, type
, TREE_OPERAND (arg0
, 0),
9857 code0
== LSHIFT_EXPR
? tree01
: tree11
);
9858 else if (code11
== MINUS_EXPR
)
9860 tree tree110
, tree111
;
9861 tree110
= TREE_OPERAND (tree11
, 0);
9862 tree111
= TREE_OPERAND (tree11
, 1);
9863 STRIP_NOPS (tree110
);
9864 STRIP_NOPS (tree111
);
9865 if (TREE_CODE (tree110
) == INTEGER_CST
9866 && 0 == compare_tree_int (tree110
,
9868 (TREE_TYPE (TREE_OPERAND
9870 && operand_equal_p (tree01
, tree111
, 0))
9871 return build2 ((code0
== LSHIFT_EXPR
9874 type
, TREE_OPERAND (arg0
, 0), tree01
);
9876 else if (code01
== MINUS_EXPR
)
9878 tree tree010
, tree011
;
9879 tree010
= TREE_OPERAND (tree01
, 0);
9880 tree011
= TREE_OPERAND (tree01
, 1);
9881 STRIP_NOPS (tree010
);
9882 STRIP_NOPS (tree011
);
9883 if (TREE_CODE (tree010
) == INTEGER_CST
9884 && 0 == compare_tree_int (tree010
,
9886 (TREE_TYPE (TREE_OPERAND
9888 && operand_equal_p (tree11
, tree011
, 0))
9889 return build2 ((code0
!= LSHIFT_EXPR
9892 type
, TREE_OPERAND (arg0
, 0), tree11
);
9898 /* In most languages, can't associate operations on floats through
9899 parentheses. Rather than remember where the parentheses were, we
9900 don't associate floats at all, unless the user has specified
9901 -funsafe-math-optimizations.
9902 And, we need to make sure type is not saturating. */
9904 if ((! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
9905 && !TYPE_SATURATING (type
))
9907 tree var0
, con0
, lit0
, minus_lit0
;
9908 tree var1
, con1
, lit1
, minus_lit1
;
9911 /* Split both trees into variables, constants, and literals. Then
9912 associate each group together, the constants with literals,
9913 then the result with variables. This increases the chances of
9914 literals being recombined later and of generating relocatable
9915 expressions for the sum of a constant and literal. */
9916 var0
= split_tree (arg0
, code
, &con0
, &lit0
, &minus_lit0
, 0);
9917 var1
= split_tree (arg1
, code
, &con1
, &lit1
, &minus_lit1
,
9918 code
== MINUS_EXPR
);
9920 /* With undefined overflow we can only associate constants
9921 with one variable. */
9922 if ((POINTER_TYPE_P (type
)
9923 || (INTEGRAL_TYPE_P (type
) && !TYPE_OVERFLOW_WRAPS (type
)))
9929 if (TREE_CODE (tmp0
) == NEGATE_EXPR
)
9930 tmp0
= TREE_OPERAND (tmp0
, 0);
9931 if (TREE_CODE (tmp1
) == NEGATE_EXPR
)
9932 tmp1
= TREE_OPERAND (tmp1
, 0);
9933 /* The only case we can still associate with two variables
9934 is if they are the same, modulo negation. */
9935 if (!operand_equal_p (tmp0
, tmp1
, 0))
9939 /* Only do something if we found more than two objects. Otherwise,
9940 nothing has changed and we risk infinite recursion. */
9942 && (2 < ((var0
!= 0) + (var1
!= 0)
9943 + (con0
!= 0) + (con1
!= 0)
9944 + (lit0
!= 0) + (lit1
!= 0)
9945 + (minus_lit0
!= 0) + (minus_lit1
!= 0))))
9947 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
9948 if (code
== MINUS_EXPR
)
9951 var0
= associate_trees (var0
, var1
, code
, type
);
9952 con0
= associate_trees (con0
, con1
, code
, type
);
9953 lit0
= associate_trees (lit0
, lit1
, code
, type
);
9954 minus_lit0
= associate_trees (minus_lit0
, minus_lit1
, code
, type
);
9956 /* Preserve the MINUS_EXPR if the negative part of the literal is
9957 greater than the positive part. Otherwise, the multiplicative
9958 folding code (i.e extract_muldiv) may be fooled in case
9959 unsigned constants are subtracted, like in the following
9960 example: ((X*2 + 4) - 8U)/2. */
9961 if (minus_lit0
&& lit0
)
9963 if (TREE_CODE (lit0
) == INTEGER_CST
9964 && TREE_CODE (minus_lit0
) == INTEGER_CST
9965 && tree_int_cst_lt (lit0
, minus_lit0
))
9967 minus_lit0
= associate_trees (minus_lit0
, lit0
,
9973 lit0
= associate_trees (lit0
, minus_lit0
,
9981 return fold_convert (type
,
9982 associate_trees (var0
, minus_lit0
,
9986 con0
= associate_trees (con0
, minus_lit0
,
9988 return fold_convert (type
,
9989 associate_trees (var0
, con0
,
9994 con0
= associate_trees (con0
, lit0
, code
, type
);
9995 return fold_convert (type
, associate_trees (var0
, con0
,
10003 /* Pointer simplifications for subtraction, simple reassociations. */
10004 if (POINTER_TYPE_P (TREE_TYPE (arg1
)) && POINTER_TYPE_P (TREE_TYPE (arg0
)))
10006 /* (PTR0 p+ A) - (PTR1 p+ B) -> (PTR0 - PTR1) + (A - B) */
10007 if (TREE_CODE (arg0
) == POINTER_PLUS_EXPR
10008 && TREE_CODE (arg1
) == POINTER_PLUS_EXPR
)
10010 tree arg00
= fold_convert (type
, TREE_OPERAND (arg0
, 0));
10011 tree arg01
= fold_convert (type
, TREE_OPERAND (arg0
, 1));
10012 tree arg10
= fold_convert (type
, TREE_OPERAND (arg1
, 0));
10013 tree arg11
= fold_convert (type
, TREE_OPERAND (arg1
, 1));
10014 return fold_build2 (PLUS_EXPR
, type
,
10015 fold_build2 (MINUS_EXPR
, type
, arg00
, arg10
),
10016 fold_build2 (MINUS_EXPR
, type
, arg01
, arg11
));
10018 /* (PTR0 p+ A) - PTR1 -> (PTR0 - PTR1) + A, assuming PTR0 - PTR1 simplifies. */
10019 else if (TREE_CODE (arg0
) == POINTER_PLUS_EXPR
)
10021 tree arg00
= fold_convert (type
, TREE_OPERAND (arg0
, 0));
10022 tree arg01
= fold_convert (type
, TREE_OPERAND (arg0
, 1));
10023 tree tmp
= fold_binary (MINUS_EXPR
, type
, arg00
, fold_convert (type
, arg1
));
10025 return fold_build2 (PLUS_EXPR
, type
, tmp
, arg01
);
10028 /* A - (-B) -> A + B */
10029 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
10030 return fold_build2 (PLUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0));
10031 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
10032 if (TREE_CODE (arg0
) == NEGATE_EXPR
10033 && (FLOAT_TYPE_P (type
)
10034 || INTEGRAL_TYPE_P (type
))
10035 && negate_expr_p (arg1
)
10036 && reorder_operands_p (arg0
, arg1
))
10037 return fold_build2 (MINUS_EXPR
, type
, negate_expr (arg1
),
10038 TREE_OPERAND (arg0
, 0));
10039 /* Convert -A - 1 to ~A. */
10040 if (INTEGRAL_TYPE_P (type
)
10041 && TREE_CODE (arg0
) == NEGATE_EXPR
10042 && integer_onep (arg1
)
10043 && !TYPE_OVERFLOW_TRAPS (type
))
10044 return fold_build1 (BIT_NOT_EXPR
, type
,
10045 fold_convert (type
, TREE_OPERAND (arg0
, 0)));
10047 /* Convert -1 - A to ~A. */
10048 if (INTEGRAL_TYPE_P (type
)
10049 && integer_all_onesp (arg0
))
10050 return fold_build1 (BIT_NOT_EXPR
, type
, op1
);
10052 if (! FLOAT_TYPE_P (type
))
10054 if (integer_zerop (arg0
))
10055 return negate_expr (fold_convert (type
, arg1
));
10056 if (integer_zerop (arg1
))
10057 return non_lvalue (fold_convert (type
, arg0
));
10059 /* Fold A - (A & B) into ~B & A. */
10060 if (!TREE_SIDE_EFFECTS (arg0
)
10061 && TREE_CODE (arg1
) == BIT_AND_EXPR
)
10063 if (operand_equal_p (arg0
, TREE_OPERAND (arg1
, 1), 0))
10065 tree arg10
= fold_convert (type
, TREE_OPERAND (arg1
, 0));
10066 return fold_build2 (BIT_AND_EXPR
, type
,
10067 fold_build1 (BIT_NOT_EXPR
, type
, arg10
),
10068 fold_convert (type
, arg0
));
10070 if (operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
10072 tree arg11
= fold_convert (type
, TREE_OPERAND (arg1
, 1));
10073 return fold_build2 (BIT_AND_EXPR
, type
,
10074 fold_build1 (BIT_NOT_EXPR
, type
, arg11
),
10075 fold_convert (type
, arg0
));
10079 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
10080 any power of 2 minus 1. */
10081 if (TREE_CODE (arg0
) == BIT_AND_EXPR
10082 && TREE_CODE (arg1
) == BIT_AND_EXPR
10083 && operand_equal_p (TREE_OPERAND (arg0
, 0),
10084 TREE_OPERAND (arg1
, 0), 0))
10086 tree mask0
= TREE_OPERAND (arg0
, 1);
10087 tree mask1
= TREE_OPERAND (arg1
, 1);
10088 tree tem
= fold_build1 (BIT_NOT_EXPR
, type
, mask0
);
10090 if (operand_equal_p (tem
, mask1
, 0))
10092 tem
= fold_build2 (BIT_XOR_EXPR
, type
,
10093 TREE_OPERAND (arg0
, 0), mask1
);
10094 return fold_build2 (MINUS_EXPR
, type
, tem
, mask1
);
10099 /* See if ARG1 is zero and X - ARG1 reduces to X. */
10100 else if (fold_real_zero_addition_p (TREE_TYPE (arg0
), arg1
, 1))
10101 return non_lvalue (fold_convert (type
, arg0
));
10103 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
10104 ARG0 is zero and X + ARG0 reduces to X, since that would mean
10105 (-ARG1 + ARG0) reduces to -ARG1. */
10106 else if (fold_real_zero_addition_p (TREE_TYPE (arg1
), arg0
, 0))
10107 return negate_expr (fold_convert (type
, arg1
));
10109 /* Fold __complex__ ( x, 0 ) - __complex__ ( 0, y ) to
10110 __complex__ ( x, -y ). This is not the same for SNaNs or if
10111 signed zeros are involved. */
10112 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
10113 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0
)))
10114 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0
)))
10116 tree rtype
= TREE_TYPE (TREE_TYPE (arg0
));
10117 tree arg0r
= fold_unary (REALPART_EXPR
, rtype
, arg0
);
10118 tree arg0i
= fold_unary (IMAGPART_EXPR
, rtype
, arg0
);
10119 bool arg0rz
= false, arg0iz
= false;
10120 if ((arg0r
&& (arg0rz
= real_zerop (arg0r
)))
10121 || (arg0i
&& (arg0iz
= real_zerop (arg0i
))))
10123 tree arg1r
= fold_unary (REALPART_EXPR
, rtype
, arg1
);
10124 tree arg1i
= fold_unary (IMAGPART_EXPR
, rtype
, arg1
);
10125 if (arg0rz
&& arg1i
&& real_zerop (arg1i
))
10127 tree rp
= fold_build1 (NEGATE_EXPR
, rtype
,
10129 : build1 (REALPART_EXPR
, rtype
, arg1
));
10130 tree ip
= arg0i
? arg0i
10131 : build1 (IMAGPART_EXPR
, rtype
, arg0
);
10132 return fold_build2 (COMPLEX_EXPR
, type
, rp
, ip
);
10134 else if (arg0iz
&& arg1r
&& real_zerop (arg1r
))
10136 tree rp
= arg0r
? arg0r
10137 : build1 (REALPART_EXPR
, rtype
, arg0
);
10138 tree ip
= fold_build1 (NEGATE_EXPR
, rtype
,
10140 : build1 (IMAGPART_EXPR
, rtype
, arg1
));
10141 return fold_build2 (COMPLEX_EXPR
, type
, rp
, ip
);
10146 /* Fold &x - &x. This can happen from &x.foo - &x.
10147 This is unsafe for certain floats even in non-IEEE formats.
10148 In IEEE, it is unsafe because it does wrong for NaNs.
10149 Also note that operand_equal_p is always false if an operand
10152 if ((!FLOAT_TYPE_P (type
) || !HONOR_NANS (TYPE_MODE (type
)))
10153 && operand_equal_p (arg0
, arg1
, 0))
10154 return fold_convert (type
, integer_zero_node
);
10156 /* A - B -> A + (-B) if B is easily negatable. */
10157 if (negate_expr_p (arg1
)
10158 && ((FLOAT_TYPE_P (type
)
10159 /* Avoid this transformation if B is a positive REAL_CST. */
10160 && (TREE_CODE (arg1
) != REAL_CST
10161 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1
))))
10162 || INTEGRAL_TYPE_P (type
)))
10163 return fold_build2 (PLUS_EXPR
, type
,
10164 fold_convert (type
, arg0
),
10165 fold_convert (type
, negate_expr (arg1
)));
10167 /* Try folding difference of addresses. */
10169 HOST_WIDE_INT diff
;
10171 if ((TREE_CODE (arg0
) == ADDR_EXPR
10172 || TREE_CODE (arg1
) == ADDR_EXPR
)
10173 && ptr_difference_const (arg0
, arg1
, &diff
))
10174 return build_int_cst_type (type
, diff
);
10177 /* Fold &a[i] - &a[j] to i-j. */
10178 if (TREE_CODE (arg0
) == ADDR_EXPR
10179 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == ARRAY_REF
10180 && TREE_CODE (arg1
) == ADDR_EXPR
10181 && TREE_CODE (TREE_OPERAND (arg1
, 0)) == ARRAY_REF
)
10183 tree aref0
= TREE_OPERAND (arg0
, 0);
10184 tree aref1
= TREE_OPERAND (arg1
, 0);
10185 if (operand_equal_p (TREE_OPERAND (aref0
, 0),
10186 TREE_OPERAND (aref1
, 0), 0))
10188 tree op0
= fold_convert (type
, TREE_OPERAND (aref0
, 1));
10189 tree op1
= fold_convert (type
, TREE_OPERAND (aref1
, 1));
10190 tree esz
= array_ref_element_size (aref0
);
10191 tree diff
= build2 (MINUS_EXPR
, type
, op0
, op1
);
10192 return fold_build2 (MULT_EXPR
, type
, diff
,
10193 fold_convert (type
, esz
));
10198 if (flag_unsafe_math_optimizations
10199 && (TREE_CODE (arg0
) == RDIV_EXPR
|| TREE_CODE (arg0
) == MULT_EXPR
)
10200 && (TREE_CODE (arg1
) == RDIV_EXPR
|| TREE_CODE (arg1
) == MULT_EXPR
)
10201 && (tem
= distribute_real_division (code
, type
, arg0
, arg1
)))
10204 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the
10205 same or one. Make sure type is not saturating. */
10206 if ((TREE_CODE (arg0
) == MULT_EXPR
10207 || TREE_CODE (arg1
) == MULT_EXPR
)
10208 && !TYPE_SATURATING (type
)
10209 && (!FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
))
10211 tree tem
= fold_plusminus_mult_expr (code
, type
, arg0
, arg1
);
10219 /* (-A) * (-B) -> A * B */
10220 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& negate_expr_p (arg1
))
10221 return fold_build2 (MULT_EXPR
, type
,
10222 fold_convert (type
, TREE_OPERAND (arg0
, 0)),
10223 fold_convert (type
, negate_expr (arg1
)));
10224 if (TREE_CODE (arg1
) == NEGATE_EXPR
&& negate_expr_p (arg0
))
10225 return fold_build2 (MULT_EXPR
, type
,
10226 fold_convert (type
, negate_expr (arg0
)),
10227 fold_convert (type
, TREE_OPERAND (arg1
, 0)));
10229 if (! FLOAT_TYPE_P (type
))
10231 if (integer_zerop (arg1
))
10232 return omit_one_operand (type
, arg1
, arg0
);
10233 if (integer_onep (arg1
))
10234 return non_lvalue (fold_convert (type
, arg0
));
10235 /* Transform x * -1 into -x. */
10236 if (integer_all_onesp (arg1
))
10237 return fold_convert (type
, negate_expr (arg0
));
10238 /* Transform x * -C into -x * C if x is easily negatable. */
10239 if (TREE_CODE (arg1
) == INTEGER_CST
10240 && tree_int_cst_sgn (arg1
) == -1
10241 && negate_expr_p (arg0
)
10242 && (tem
= negate_expr (arg1
)) != arg1
10243 && !TREE_OVERFLOW (tem
))
10244 return fold_build2 (MULT_EXPR
, type
,
10245 negate_expr (arg0
), tem
);
10247 /* (a * (1 << b)) is (a << b) */
10248 if (TREE_CODE (arg1
) == LSHIFT_EXPR
10249 && integer_onep (TREE_OPERAND (arg1
, 0)))
10250 return fold_build2 (LSHIFT_EXPR
, type
, arg0
,
10251 TREE_OPERAND (arg1
, 1));
10252 if (TREE_CODE (arg0
) == LSHIFT_EXPR
10253 && integer_onep (TREE_OPERAND (arg0
, 0)))
10254 return fold_build2 (LSHIFT_EXPR
, type
, arg1
,
10255 TREE_OPERAND (arg0
, 1));
10257 strict_overflow_p
= false;
10258 if (TREE_CODE (arg1
) == INTEGER_CST
10259 && 0 != (tem
= extract_muldiv (op0
,
10260 fold_convert (type
, arg1
),
10262 &strict_overflow_p
)))
10264 if (strict_overflow_p
)
10265 fold_overflow_warning (("assuming signed overflow does not "
10266 "occur when simplifying "
10268 WARN_STRICT_OVERFLOW_MISC
);
10269 return fold_convert (type
, tem
);
10272 /* Optimize z * conj(z) for integer complex numbers. */
10273 if (TREE_CODE (arg0
) == CONJ_EXPR
10274 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
10275 return fold_mult_zconjz (type
, arg1
);
10276 if (TREE_CODE (arg1
) == CONJ_EXPR
10277 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
10278 return fold_mult_zconjz (type
, arg0
);
10282 /* Maybe fold x * 0 to 0. The expressions aren't the same
10283 when x is NaN, since x * 0 is also NaN. Nor are they the
10284 same in modes with signed zeros, since multiplying a
10285 negative value by 0 gives -0, not +0. */
10286 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
)))
10287 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0
)))
10288 && real_zerop (arg1
))
10289 return omit_one_operand (type
, arg1
, arg0
);
10290 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
10291 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
10292 && real_onep (arg1
))
10293 return non_lvalue (fold_convert (type
, arg0
));
10295 /* Transform x * -1.0 into -x. */
10296 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
10297 && real_minus_onep (arg1
))
10298 return fold_convert (type
, negate_expr (arg0
));
10300 /* Convert (C1/X)*C2 into (C1*C2)/X. */
10301 if (flag_unsafe_math_optimizations
10302 && TREE_CODE (arg0
) == RDIV_EXPR
10303 && TREE_CODE (arg1
) == REAL_CST
10304 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == REAL_CST
)
10306 tree tem
= const_binop (MULT_EXPR
, TREE_OPERAND (arg0
, 0),
10309 return fold_build2 (RDIV_EXPR
, type
, tem
,
10310 TREE_OPERAND (arg0
, 1));
10313 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
10314 if (operand_equal_p (arg0
, arg1
, 0))
10316 tree tem
= fold_strip_sign_ops (arg0
);
10317 if (tem
!= NULL_TREE
)
10319 tem
= fold_convert (type
, tem
);
10320 return fold_build2 (MULT_EXPR
, type
, tem
, tem
);
10324 /* Fold z * +-I to __complex__ (-+__imag z, +-__real z).
10325 This is not the same for NaNs or if signed zeros are
10327 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
)))
10328 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0
)))
10329 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0
))
10330 && TREE_CODE (arg1
) == COMPLEX_CST
10331 && real_zerop (TREE_REALPART (arg1
)))
10333 tree rtype
= TREE_TYPE (TREE_TYPE (arg0
));
10334 if (real_onep (TREE_IMAGPART (arg1
)))
10335 return fold_build2 (COMPLEX_EXPR
, type
,
10336 negate_expr (fold_build1 (IMAGPART_EXPR
,
10338 fold_build1 (REALPART_EXPR
, rtype
, arg0
));
10339 else if (real_minus_onep (TREE_IMAGPART (arg1
)))
10340 return fold_build2 (COMPLEX_EXPR
, type
,
10341 fold_build1 (IMAGPART_EXPR
, rtype
, arg0
),
10342 negate_expr (fold_build1 (REALPART_EXPR
,
10346 /* Optimize z * conj(z) for floating point complex numbers.
10347 Guarded by flag_unsafe_math_optimizations as non-finite
10348 imaginary components don't produce scalar results. */
10349 if (flag_unsafe_math_optimizations
10350 && TREE_CODE (arg0
) == CONJ_EXPR
10351 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
10352 return fold_mult_zconjz (type
, arg1
);
10353 if (flag_unsafe_math_optimizations
10354 && TREE_CODE (arg1
) == CONJ_EXPR
10355 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
10356 return fold_mult_zconjz (type
, arg0
);
10358 if (flag_unsafe_math_optimizations
)
10360 enum built_in_function fcode0
= builtin_mathfn_code (arg0
);
10361 enum built_in_function fcode1
= builtin_mathfn_code (arg1
);
10363 /* Optimizations of root(...)*root(...). */
10364 if (fcode0
== fcode1
&& BUILTIN_ROOT_P (fcode0
))
10367 tree arg00
= CALL_EXPR_ARG (arg0
, 0);
10368 tree arg10
= CALL_EXPR_ARG (arg1
, 0);
10370 /* Optimize sqrt(x)*sqrt(x) as x. */
10371 if (BUILTIN_SQRT_P (fcode0
)
10372 && operand_equal_p (arg00
, arg10
, 0)
10373 && ! HONOR_SNANS (TYPE_MODE (type
)))
10376 /* Optimize root(x)*root(y) as root(x*y). */
10377 rootfn
= TREE_OPERAND (CALL_EXPR_FN (arg0
), 0);
10378 arg
= fold_build2 (MULT_EXPR
, type
, arg00
, arg10
);
10379 return build_call_expr (rootfn
, 1, arg
);
10382 /* Optimize expN(x)*expN(y) as expN(x+y). */
10383 if (fcode0
== fcode1
&& BUILTIN_EXPONENT_P (fcode0
))
10385 tree expfn
= TREE_OPERAND (CALL_EXPR_FN (arg0
), 0);
10386 tree arg
= fold_build2 (PLUS_EXPR
, type
,
10387 CALL_EXPR_ARG (arg0
, 0),
10388 CALL_EXPR_ARG (arg1
, 0));
10389 return build_call_expr (expfn
, 1, arg
);
10392 /* Optimizations of pow(...)*pow(...). */
10393 if ((fcode0
== BUILT_IN_POW
&& fcode1
== BUILT_IN_POW
)
10394 || (fcode0
== BUILT_IN_POWF
&& fcode1
== BUILT_IN_POWF
)
10395 || (fcode0
== BUILT_IN_POWL
&& fcode1
== BUILT_IN_POWL
))
10397 tree arg00
= CALL_EXPR_ARG (arg0
, 0);
10398 tree arg01
= CALL_EXPR_ARG (arg0
, 1);
10399 tree arg10
= CALL_EXPR_ARG (arg1
, 0);
10400 tree arg11
= CALL_EXPR_ARG (arg1
, 1);
10402 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
10403 if (operand_equal_p (arg01
, arg11
, 0))
10405 tree powfn
= TREE_OPERAND (CALL_EXPR_FN (arg0
), 0);
10406 tree arg
= fold_build2 (MULT_EXPR
, type
, arg00
, arg10
);
10407 return build_call_expr (powfn
, 2, arg
, arg01
);
10410 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
10411 if (operand_equal_p (arg00
, arg10
, 0))
10413 tree powfn
= TREE_OPERAND (CALL_EXPR_FN (arg0
), 0);
10414 tree arg
= fold_build2 (PLUS_EXPR
, type
, arg01
, arg11
);
10415 return build_call_expr (powfn
, 2, arg00
, arg
);
10419 /* Optimize tan(x)*cos(x) as sin(x). */
10420 if (((fcode0
== BUILT_IN_TAN
&& fcode1
== BUILT_IN_COS
)
10421 || (fcode0
== BUILT_IN_TANF
&& fcode1
== BUILT_IN_COSF
)
10422 || (fcode0
== BUILT_IN_TANL
&& fcode1
== BUILT_IN_COSL
)
10423 || (fcode0
== BUILT_IN_COS
&& fcode1
== BUILT_IN_TAN
)
10424 || (fcode0
== BUILT_IN_COSF
&& fcode1
== BUILT_IN_TANF
)
10425 || (fcode0
== BUILT_IN_COSL
&& fcode1
== BUILT_IN_TANL
))
10426 && operand_equal_p (CALL_EXPR_ARG (arg0
, 0),
10427 CALL_EXPR_ARG (arg1
, 0), 0))
10429 tree sinfn
= mathfn_built_in (type
, BUILT_IN_SIN
);
10431 if (sinfn
!= NULL_TREE
)
10432 return build_call_expr (sinfn
, 1, CALL_EXPR_ARG (arg0
, 0));
10435 /* Optimize x*pow(x,c) as pow(x,c+1). */
10436 if (fcode1
== BUILT_IN_POW
10437 || fcode1
== BUILT_IN_POWF
10438 || fcode1
== BUILT_IN_POWL
)
10440 tree arg10
= CALL_EXPR_ARG (arg1
, 0);
10441 tree arg11
= CALL_EXPR_ARG (arg1
, 1);
10442 if (TREE_CODE (arg11
) == REAL_CST
10443 && !TREE_OVERFLOW (arg11
)
10444 && operand_equal_p (arg0
, arg10
, 0))
10446 tree powfn
= TREE_OPERAND (CALL_EXPR_FN (arg1
), 0);
10450 c
= TREE_REAL_CST (arg11
);
10451 real_arithmetic (&c
, PLUS_EXPR
, &c
, &dconst1
);
10452 arg
= build_real (type
, c
);
10453 return build_call_expr (powfn
, 2, arg0
, arg
);
10457 /* Optimize pow(x,c)*x as pow(x,c+1). */
10458 if (fcode0
== BUILT_IN_POW
10459 || fcode0
== BUILT_IN_POWF
10460 || fcode0
== BUILT_IN_POWL
)
10462 tree arg00
= CALL_EXPR_ARG (arg0
, 0);
10463 tree arg01
= CALL_EXPR_ARG (arg0
, 1);
10464 if (TREE_CODE (arg01
) == REAL_CST
10465 && !TREE_OVERFLOW (arg01
)
10466 && operand_equal_p (arg1
, arg00
, 0))
10468 tree powfn
= TREE_OPERAND (CALL_EXPR_FN (arg0
), 0);
10472 c
= TREE_REAL_CST (arg01
);
10473 real_arithmetic (&c
, PLUS_EXPR
, &c
, &dconst1
);
10474 arg
= build_real (type
, c
);
10475 return build_call_expr (powfn
, 2, arg1
, arg
);
10479 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
10480 if (! optimize_size
10481 && operand_equal_p (arg0
, arg1
, 0))
10483 tree powfn
= mathfn_built_in (type
, BUILT_IN_POW
);
10487 tree arg
= build_real (type
, dconst2
);
10488 return build_call_expr (powfn
, 2, arg0
, arg
);
10497 if (integer_all_onesp (arg1
))
10498 return omit_one_operand (type
, arg1
, arg0
);
10499 if (integer_zerop (arg1
))
10500 return non_lvalue (fold_convert (type
, arg0
));
10501 if (operand_equal_p (arg0
, arg1
, 0))
10502 return non_lvalue (fold_convert (type
, arg0
));
10504 /* ~X | X is -1. */
10505 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
10506 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
10508 t1
= fold_convert (type
, integer_zero_node
);
10509 t1
= fold_unary (BIT_NOT_EXPR
, type
, t1
);
10510 return omit_one_operand (type
, t1
, arg1
);
10513 /* X | ~X is -1. */
10514 if (TREE_CODE (arg1
) == BIT_NOT_EXPR
10515 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
10517 t1
= fold_convert (type
, integer_zero_node
);
10518 t1
= fold_unary (BIT_NOT_EXPR
, type
, t1
);
10519 return omit_one_operand (type
, t1
, arg0
);
10522 /* Canonicalize (X & C1) | C2. */
10523 if (TREE_CODE (arg0
) == BIT_AND_EXPR
10524 && TREE_CODE (arg1
) == INTEGER_CST
10525 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
10527 unsigned HOST_WIDE_INT hi1
, lo1
, hi2
, lo2
, mlo
, mhi
;
10528 int width
= TYPE_PRECISION (type
);
10529 hi1
= TREE_INT_CST_HIGH (TREE_OPERAND (arg0
, 1));
10530 lo1
= TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1));
10531 hi2
= TREE_INT_CST_HIGH (arg1
);
10532 lo2
= TREE_INT_CST_LOW (arg1
);
10534 /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
10535 if ((hi1
& hi2
) == hi1
&& (lo1
& lo2
) == lo1
)
10536 return omit_one_operand (type
, arg1
, TREE_OPERAND (arg0
, 0));
10538 if (width
> HOST_BITS_PER_WIDE_INT
)
10540 mhi
= (unsigned HOST_WIDE_INT
) -1
10541 >> (2 * HOST_BITS_PER_WIDE_INT
- width
);
10547 mlo
= (unsigned HOST_WIDE_INT
) -1
10548 >> (HOST_BITS_PER_WIDE_INT
- width
);
10551 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
10552 if ((~(hi1
| hi2
) & mhi
) == 0 && (~(lo1
| lo2
) & mlo
) == 0)
10553 return fold_build2 (BIT_IOR_EXPR
, type
,
10554 TREE_OPERAND (arg0
, 0), arg1
);
10556 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2. */
10559 if ((hi1
& ~hi2
) != hi1
|| (lo1
& ~lo2
) != lo1
)
10560 return fold_build2 (BIT_IOR_EXPR
, type
,
10561 fold_build2 (BIT_AND_EXPR
, type
,
10562 TREE_OPERAND (arg0
, 0),
10563 build_int_cst_wide (type
,
10569 /* (X & Y) | Y is (X, Y). */
10570 if (TREE_CODE (arg0
) == BIT_AND_EXPR
10571 && operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
10572 return omit_one_operand (type
, arg1
, TREE_OPERAND (arg0
, 0));
10573 /* (X & Y) | X is (Y, X). */
10574 if (TREE_CODE (arg0
) == BIT_AND_EXPR
10575 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0)
10576 && reorder_operands_p (TREE_OPERAND (arg0
, 1), arg1
))
10577 return omit_one_operand (type
, arg1
, TREE_OPERAND (arg0
, 1));
10578 /* X | (X & Y) is (Y, X). */
10579 if (TREE_CODE (arg1
) == BIT_AND_EXPR
10580 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0)
10581 && reorder_operands_p (arg0
, TREE_OPERAND (arg1
, 1)))
10582 return omit_one_operand (type
, arg0
, TREE_OPERAND (arg1
, 1));
10583 /* X | (Y & X) is (Y, X). */
10584 if (TREE_CODE (arg1
) == BIT_AND_EXPR
10585 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 1), 0)
10586 && reorder_operands_p (arg0
, TREE_OPERAND (arg1
, 0)))
10587 return omit_one_operand (type
, arg0
, TREE_OPERAND (arg1
, 0));
10589 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
10590 if (t1
!= NULL_TREE
)
10593 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
10595 This results in more efficient code for machines without a NAND
10596 instruction. Combine will canonicalize to the first form
10597 which will allow use of NAND instructions provided by the
10598 backend if they exist. */
10599 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
10600 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
10602 return fold_build1 (BIT_NOT_EXPR
, type
,
10603 build2 (BIT_AND_EXPR
, type
,
10604 TREE_OPERAND (arg0
, 0),
10605 TREE_OPERAND (arg1
, 0)));
10608 /* See if this can be simplified into a rotate first. If that
10609 is unsuccessful continue in the association code. */
10613 if (integer_zerop (arg1
))
10614 return non_lvalue (fold_convert (type
, arg0
));
10615 if (integer_all_onesp (arg1
))
10616 return fold_build1 (BIT_NOT_EXPR
, type
, op0
);
10617 if (operand_equal_p (arg0
, arg1
, 0))
10618 return omit_one_operand (type
, integer_zero_node
, arg0
);
10620 /* ~X ^ X is -1. */
10621 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
10622 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
10624 t1
= fold_convert (type
, integer_zero_node
);
10625 t1
= fold_unary (BIT_NOT_EXPR
, type
, t1
);
10626 return omit_one_operand (type
, t1
, arg1
);
10629 /* X ^ ~X is -1. */
10630 if (TREE_CODE (arg1
) == BIT_NOT_EXPR
10631 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
10633 t1
= fold_convert (type
, integer_zero_node
);
10634 t1
= fold_unary (BIT_NOT_EXPR
, type
, t1
);
10635 return omit_one_operand (type
, t1
, arg0
);
10638 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
10639 with a constant, and the two constants have no bits in common,
10640 we should treat this as a BIT_IOR_EXPR since this may produce more
10641 simplifications. */
10642 if (TREE_CODE (arg0
) == BIT_AND_EXPR
10643 && TREE_CODE (arg1
) == BIT_AND_EXPR
10644 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
10645 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
10646 && integer_zerop (const_binop (BIT_AND_EXPR
,
10647 TREE_OPERAND (arg0
, 1),
10648 TREE_OPERAND (arg1
, 1), 0)))
10650 code
= BIT_IOR_EXPR
;
10654 /* (X | Y) ^ X -> Y & ~ X*/
10655 if (TREE_CODE (arg0
) == BIT_IOR_EXPR
10656 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
10658 tree t2
= TREE_OPERAND (arg0
, 1);
10659 t1
= fold_build1 (BIT_NOT_EXPR
, TREE_TYPE (arg1
),
10661 t1
= fold_build2 (BIT_AND_EXPR
, type
, fold_convert (type
, t2
),
10662 fold_convert (type
, t1
));
10666 /* (Y | X) ^ X -> Y & ~ X*/
10667 if (TREE_CODE (arg0
) == BIT_IOR_EXPR
10668 && operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
10670 tree t2
= TREE_OPERAND (arg0
, 0);
10671 t1
= fold_build1 (BIT_NOT_EXPR
, TREE_TYPE (arg1
),
10673 t1
= fold_build2 (BIT_AND_EXPR
, type
, fold_convert (type
, t2
),
10674 fold_convert (type
, t1
));
10678 /* X ^ (X | Y) -> Y & ~ X*/
10679 if (TREE_CODE (arg1
) == BIT_IOR_EXPR
10680 && operand_equal_p (TREE_OPERAND (arg1
, 0), arg0
, 0))
10682 tree t2
= TREE_OPERAND (arg1
, 1);
10683 t1
= fold_build1 (BIT_NOT_EXPR
, TREE_TYPE (arg0
),
10685 t1
= fold_build2 (BIT_AND_EXPR
, type
, fold_convert (type
, t2
),
10686 fold_convert (type
, t1
));
10690 /* X ^ (Y | X) -> Y & ~ X*/
10691 if (TREE_CODE (arg1
) == BIT_IOR_EXPR
10692 && operand_equal_p (TREE_OPERAND (arg1
, 1), arg0
, 0))
10694 tree t2
= TREE_OPERAND (arg1
, 0);
10695 t1
= fold_build1 (BIT_NOT_EXPR
, TREE_TYPE (arg0
),
10697 t1
= fold_build2 (BIT_AND_EXPR
, type
, fold_convert (type
, t2
),
10698 fold_convert (type
, t1
));
10702 /* Convert ~X ^ ~Y to X ^ Y. */
10703 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
10704 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
10705 return fold_build2 (code
, type
,
10706 fold_convert (type
, TREE_OPERAND (arg0
, 0)),
10707 fold_convert (type
, TREE_OPERAND (arg1
, 0)));
10709 /* Convert ~X ^ C to X ^ ~C. */
10710 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
10711 && TREE_CODE (arg1
) == INTEGER_CST
)
10712 return fold_build2 (code
, type
,
10713 fold_convert (type
, TREE_OPERAND (arg0
, 0)),
10714 fold_build1 (BIT_NOT_EXPR
, type
, arg1
));
10716 /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
10717 if (TREE_CODE (arg0
) == BIT_AND_EXPR
10718 && integer_onep (TREE_OPERAND (arg0
, 1))
10719 && integer_onep (arg1
))
10720 return fold_build2 (EQ_EXPR
, type
, arg0
,
10721 build_int_cst (TREE_TYPE (arg0
), 0));
10723 /* Fold (X & Y) ^ Y as ~X & Y. */
10724 if (TREE_CODE (arg0
) == BIT_AND_EXPR
10725 && operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
10727 tem
= fold_convert (type
, TREE_OPERAND (arg0
, 0));
10728 return fold_build2 (BIT_AND_EXPR
, type
,
10729 fold_build1 (BIT_NOT_EXPR
, type
, tem
),
10730 fold_convert (type
, arg1
));
10732 /* Fold (X & Y) ^ X as ~Y & X. */
10733 if (TREE_CODE (arg0
) == BIT_AND_EXPR
10734 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0)
10735 && reorder_operands_p (TREE_OPERAND (arg0
, 1), arg1
))
10737 tem
= fold_convert (type
, TREE_OPERAND (arg0
, 1));
10738 return fold_build2 (BIT_AND_EXPR
, type
,
10739 fold_build1 (BIT_NOT_EXPR
, type
, tem
),
10740 fold_convert (type
, arg1
));
10742 /* Fold X ^ (X & Y) as X & ~Y. */
10743 if (TREE_CODE (arg1
) == BIT_AND_EXPR
10744 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
10746 tem
= fold_convert (type
, TREE_OPERAND (arg1
, 1));
10747 return fold_build2 (BIT_AND_EXPR
, type
,
10748 fold_convert (type
, arg0
),
10749 fold_build1 (BIT_NOT_EXPR
, type
, tem
));
10751 /* Fold X ^ (Y & X) as ~Y & X. */
10752 if (TREE_CODE (arg1
) == BIT_AND_EXPR
10753 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 1), 0)
10754 && reorder_operands_p (arg0
, TREE_OPERAND (arg1
, 0)))
10756 tem
= fold_convert (type
, TREE_OPERAND (arg1
, 0));
10757 return fold_build2 (BIT_AND_EXPR
, type
,
10758 fold_build1 (BIT_NOT_EXPR
, type
, tem
),
10759 fold_convert (type
, arg0
));
10762 /* See if this can be simplified into a rotate first. If that
10763 is unsuccessful continue in the association code. */
10767 if (integer_all_onesp (arg1
))
10768 return non_lvalue (fold_convert (type
, arg0
));
10769 if (integer_zerop (arg1
))
10770 return omit_one_operand (type
, arg1
, arg0
);
10771 if (operand_equal_p (arg0
, arg1
, 0))
10772 return non_lvalue (fold_convert (type
, arg0
));
10774 /* ~X & X is always zero. */
10775 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
10776 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
10777 return omit_one_operand (type
, integer_zero_node
, arg1
);
10779 /* X & ~X is always zero. */
10780 if (TREE_CODE (arg1
) == BIT_NOT_EXPR
10781 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
10782 return omit_one_operand (type
, integer_zero_node
, arg0
);
10784 /* Canonicalize (X | C1) & C2 as (X & C2) | (C1 & C2). */
10785 if (TREE_CODE (arg0
) == BIT_IOR_EXPR
10786 && TREE_CODE (arg1
) == INTEGER_CST
10787 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
10788 return fold_build2 (BIT_IOR_EXPR
, type
,
10789 fold_build2 (BIT_AND_EXPR
, type
,
10790 TREE_OPERAND (arg0
, 0), arg1
),
10791 fold_build2 (BIT_AND_EXPR
, type
,
10792 TREE_OPERAND (arg0
, 1), arg1
));
10794 /* (X | Y) & Y is (X, Y). */
10795 if (TREE_CODE (arg0
) == BIT_IOR_EXPR
10796 && operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
10797 return omit_one_operand (type
, arg1
, TREE_OPERAND (arg0
, 0));
10798 /* (X | Y) & X is (Y, X). */
10799 if (TREE_CODE (arg0
) == BIT_IOR_EXPR
10800 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0)
10801 && reorder_operands_p (TREE_OPERAND (arg0
, 1), arg1
))
10802 return omit_one_operand (type
, arg1
, TREE_OPERAND (arg0
, 1));
10803 /* X & (X | Y) is (Y, X). */
10804 if (TREE_CODE (arg1
) == BIT_IOR_EXPR
10805 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0)
10806 && reorder_operands_p (arg0
, TREE_OPERAND (arg1
, 1)))
10807 return omit_one_operand (type
, arg0
, TREE_OPERAND (arg1
, 1));
10808 /* X & (Y | X) is (Y, X). */
10809 if (TREE_CODE (arg1
) == BIT_IOR_EXPR
10810 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 1), 0)
10811 && reorder_operands_p (arg0
, TREE_OPERAND (arg1
, 0)))
10812 return omit_one_operand (type
, arg0
, TREE_OPERAND (arg1
, 0));
10814 /* Fold (X ^ 1) & 1 as (X & 1) == 0. */
10815 if (TREE_CODE (arg0
) == BIT_XOR_EXPR
10816 && integer_onep (TREE_OPERAND (arg0
, 1))
10817 && integer_onep (arg1
))
10819 tem
= TREE_OPERAND (arg0
, 0);
10820 return fold_build2 (EQ_EXPR
, type
,
10821 fold_build2 (BIT_AND_EXPR
, TREE_TYPE (tem
), tem
,
10822 build_int_cst (TREE_TYPE (tem
), 1)),
10823 build_int_cst (TREE_TYPE (tem
), 0));
10825 /* Fold ~X & 1 as (X & 1) == 0. */
10826 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
10827 && integer_onep (arg1
))
10829 tem
= TREE_OPERAND (arg0
, 0);
10830 return fold_build2 (EQ_EXPR
, type
,
10831 fold_build2 (BIT_AND_EXPR
, TREE_TYPE (tem
), tem
,
10832 build_int_cst (TREE_TYPE (tem
), 1)),
10833 build_int_cst (TREE_TYPE (tem
), 0));
10836 /* Fold (X ^ Y) & Y as ~X & Y. */
10837 if (TREE_CODE (arg0
) == BIT_XOR_EXPR
10838 && operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
10840 tem
= fold_convert (type
, TREE_OPERAND (arg0
, 0));
10841 return fold_build2 (BIT_AND_EXPR
, type
,
10842 fold_build1 (BIT_NOT_EXPR
, type
, tem
),
10843 fold_convert (type
, arg1
));
10845 /* Fold (X ^ Y) & X as ~Y & X. */
10846 if (TREE_CODE (arg0
) == BIT_XOR_EXPR
10847 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0)
10848 && reorder_operands_p (TREE_OPERAND (arg0
, 1), arg1
))
10850 tem
= fold_convert (type
, TREE_OPERAND (arg0
, 1));
10851 return fold_build2 (BIT_AND_EXPR
, type
,
10852 fold_build1 (BIT_NOT_EXPR
, type
, tem
),
10853 fold_convert (type
, arg1
));
10855 /* Fold X & (X ^ Y) as X & ~Y. */
10856 if (TREE_CODE (arg1
) == BIT_XOR_EXPR
10857 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
10859 tem
= fold_convert (type
, TREE_OPERAND (arg1
, 1));
10860 return fold_build2 (BIT_AND_EXPR
, type
,
10861 fold_convert (type
, arg0
),
10862 fold_build1 (BIT_NOT_EXPR
, type
, tem
));
10864 /* Fold X & (Y ^ X) as ~Y & X. */
10865 if (TREE_CODE (arg1
) == BIT_XOR_EXPR
10866 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 1), 0)
10867 && reorder_operands_p (arg0
, TREE_OPERAND (arg1
, 0)))
10869 tem
= fold_convert (type
, TREE_OPERAND (arg1
, 0));
10870 return fold_build2 (BIT_AND_EXPR
, type
,
10871 fold_build1 (BIT_NOT_EXPR
, type
, tem
),
10872 fold_convert (type
, arg0
));
10875 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
10876 if (t1
!= NULL_TREE
)
10878 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
10879 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) == NOP_EXPR
10880 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
10883 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)));
10885 if (prec
< BITS_PER_WORD
&& prec
< HOST_BITS_PER_WIDE_INT
10886 && (~TREE_INT_CST_LOW (arg1
)
10887 & (((HOST_WIDE_INT
) 1 << prec
) - 1)) == 0)
10888 return fold_convert (type
, TREE_OPERAND (arg0
, 0));
10891 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
10893 This results in more efficient code for machines without a NOR
10894 instruction. Combine will canonicalize to the first form
10895 which will allow use of NOR instructions provided by the
10896 backend if they exist. */
10897 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
10898 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
10900 return fold_build1 (BIT_NOT_EXPR
, type
,
10901 build2 (BIT_IOR_EXPR
, type
,
10902 TREE_OPERAND (arg0
, 0),
10903 TREE_OPERAND (arg1
, 0)));
10909 /* Don't touch a floating-point divide by zero unless the mode
10910 of the constant can represent infinity. */
10911 if (TREE_CODE (arg1
) == REAL_CST
10912 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1
)))
10913 && real_zerop (arg1
))
10916 /* Optimize A / A to 1.0 if we don't care about
10917 NaNs or Infinities. Skip the transformation
10918 for non-real operands. */
10919 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg0
))
10920 && ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
)))
10921 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg0
)))
10922 && operand_equal_p (arg0
, arg1
, 0))
10924 tree r
= build_real (TREE_TYPE (arg0
), dconst1
);
10926 return omit_two_operands (type
, r
, arg0
, arg1
);
10929 /* The complex version of the above A / A optimization. */
10930 if (COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0
))
10931 && operand_equal_p (arg0
, arg1
, 0))
10933 tree elem_type
= TREE_TYPE (TREE_TYPE (arg0
));
10934 if (! HONOR_NANS (TYPE_MODE (elem_type
))
10935 && ! HONOR_INFINITIES (TYPE_MODE (elem_type
)))
10937 tree r
= build_real (elem_type
, dconst1
);
10938 /* omit_two_operands will call fold_convert for us. */
10939 return omit_two_operands (type
, r
, arg0
, arg1
);
10943 /* (-A) / (-B) -> A / B */
10944 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& negate_expr_p (arg1
))
10945 return fold_build2 (RDIV_EXPR
, type
,
10946 TREE_OPERAND (arg0
, 0),
10947 negate_expr (arg1
));
10948 if (TREE_CODE (arg1
) == NEGATE_EXPR
&& negate_expr_p (arg0
))
10949 return fold_build2 (RDIV_EXPR
, type
,
10950 negate_expr (arg0
),
10951 TREE_OPERAND (arg1
, 0));
10953 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
10954 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
10955 && real_onep (arg1
))
10956 return non_lvalue (fold_convert (type
, arg0
));
10958 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
10959 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
10960 && real_minus_onep (arg1
))
10961 return non_lvalue (fold_convert (type
, negate_expr (arg0
)));
10963 /* If ARG1 is a constant, we can convert this to a multiply by the
10964 reciprocal. This does not have the same rounding properties,
10965 so only do this if -funsafe-math-optimizations. We can actually
10966 always safely do it if ARG1 is a power of two, but it's hard to
10967 tell if it is or not in a portable manner. */
10968 if (TREE_CODE (arg1
) == REAL_CST
)
10970 if (flag_unsafe_math_optimizations
10971 && 0 != (tem
= const_binop (code
, build_real (type
, dconst1
),
10973 return fold_build2 (MULT_EXPR
, type
, arg0
, tem
);
10974 /* Find the reciprocal if optimizing and the result is exact. */
10978 r
= TREE_REAL_CST (arg1
);
10979 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0
)), &r
))
10981 tem
= build_real (type
, r
);
10982 return fold_build2 (MULT_EXPR
, type
,
10983 fold_convert (type
, arg0
), tem
);
10987 /* Convert A/B/C to A/(B*C). */
10988 if (flag_unsafe_math_optimizations
10989 && TREE_CODE (arg0
) == RDIV_EXPR
)
10990 return fold_build2 (RDIV_EXPR
, type
, TREE_OPERAND (arg0
, 0),
10991 fold_build2 (MULT_EXPR
, type
,
10992 TREE_OPERAND (arg0
, 1), arg1
));
10994 /* Convert A/(B/C) to (A/B)*C. */
10995 if (flag_unsafe_math_optimizations
10996 && TREE_CODE (arg1
) == RDIV_EXPR
)
10997 return fold_build2 (MULT_EXPR
, type
,
10998 fold_build2 (RDIV_EXPR
, type
, arg0
,
10999 TREE_OPERAND (arg1
, 0)),
11000 TREE_OPERAND (arg1
, 1));
11002 /* Convert C1/(X*C2) into (C1/C2)/X. */
11003 if (flag_unsafe_math_optimizations
11004 && TREE_CODE (arg1
) == MULT_EXPR
11005 && TREE_CODE (arg0
) == REAL_CST
11006 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == REAL_CST
)
11008 tree tem
= const_binop (RDIV_EXPR
, arg0
,
11009 TREE_OPERAND (arg1
, 1), 0);
11011 return fold_build2 (RDIV_EXPR
, type
, tem
,
11012 TREE_OPERAND (arg1
, 0));
11015 if (flag_unsafe_math_optimizations
)
11017 enum built_in_function fcode0
= builtin_mathfn_code (arg0
);
11018 enum built_in_function fcode1
= builtin_mathfn_code (arg1
);
11020 /* Optimize sin(x)/cos(x) as tan(x). */
11021 if (((fcode0
== BUILT_IN_SIN
&& fcode1
== BUILT_IN_COS
)
11022 || (fcode0
== BUILT_IN_SINF
&& fcode1
== BUILT_IN_COSF
)
11023 || (fcode0
== BUILT_IN_SINL
&& fcode1
== BUILT_IN_COSL
))
11024 && operand_equal_p (CALL_EXPR_ARG (arg0
, 0),
11025 CALL_EXPR_ARG (arg1
, 0), 0))
11027 tree tanfn
= mathfn_built_in (type
, BUILT_IN_TAN
);
11029 if (tanfn
!= NULL_TREE
)
11030 return build_call_expr (tanfn
, 1, CALL_EXPR_ARG (arg0
, 0));
11033 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
11034 if (((fcode0
== BUILT_IN_COS
&& fcode1
== BUILT_IN_SIN
)
11035 || (fcode0
== BUILT_IN_COSF
&& fcode1
== BUILT_IN_SINF
)
11036 || (fcode0
== BUILT_IN_COSL
&& fcode1
== BUILT_IN_SINL
))
11037 && operand_equal_p (CALL_EXPR_ARG (arg0
, 0),
11038 CALL_EXPR_ARG (arg1
, 0), 0))
11040 tree tanfn
= mathfn_built_in (type
, BUILT_IN_TAN
);
11042 if (tanfn
!= NULL_TREE
)
11044 tree tmp
= build_call_expr (tanfn
, 1, CALL_EXPR_ARG (arg0
, 0));
11045 return fold_build2 (RDIV_EXPR
, type
,
11046 build_real (type
, dconst1
), tmp
);
11050 /* Optimize sin(x)/tan(x) as cos(x) if we don't care about
11051 NaNs or Infinities. */
11052 if (((fcode0
== BUILT_IN_SIN
&& fcode1
== BUILT_IN_TAN
)
11053 || (fcode0
== BUILT_IN_SINF
&& fcode1
== BUILT_IN_TANF
)
11054 || (fcode0
== BUILT_IN_SINL
&& fcode1
== BUILT_IN_TANL
)))
11056 tree arg00
= CALL_EXPR_ARG (arg0
, 0);
11057 tree arg01
= CALL_EXPR_ARG (arg1
, 0);
11059 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00
)))
11060 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00
)))
11061 && operand_equal_p (arg00
, arg01
, 0))
11063 tree cosfn
= mathfn_built_in (type
, BUILT_IN_COS
);
11065 if (cosfn
!= NULL_TREE
)
11066 return build_call_expr (cosfn
, 1, arg00
);
11070 /* Optimize tan(x)/sin(x) as 1.0/cos(x) if we don't care about
11071 NaNs or Infinities. */
11072 if (((fcode0
== BUILT_IN_TAN
&& fcode1
== BUILT_IN_SIN
)
11073 || (fcode0
== BUILT_IN_TANF
&& fcode1
== BUILT_IN_SINF
)
11074 || (fcode0
== BUILT_IN_TANL
&& fcode1
== BUILT_IN_SINL
)))
11076 tree arg00
= CALL_EXPR_ARG (arg0
, 0);
11077 tree arg01
= CALL_EXPR_ARG (arg1
, 0);
11079 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00
)))
11080 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00
)))
11081 && operand_equal_p (arg00
, arg01
, 0))
11083 tree cosfn
= mathfn_built_in (type
, BUILT_IN_COS
);
11085 if (cosfn
!= NULL_TREE
)
11087 tree tmp
= build_call_expr (cosfn
, 1, arg00
);
11088 return fold_build2 (RDIV_EXPR
, type
,
11089 build_real (type
, dconst1
),
11095 /* Optimize pow(x,c)/x as pow(x,c-1). */
11096 if (fcode0
== BUILT_IN_POW
11097 || fcode0
== BUILT_IN_POWF
11098 || fcode0
== BUILT_IN_POWL
)
11100 tree arg00
= CALL_EXPR_ARG (arg0
, 0);
11101 tree arg01
= CALL_EXPR_ARG (arg0
, 1);
11102 if (TREE_CODE (arg01
) == REAL_CST
11103 && !TREE_OVERFLOW (arg01
)
11104 && operand_equal_p (arg1
, arg00
, 0))
11106 tree powfn
= TREE_OPERAND (CALL_EXPR_FN (arg0
), 0);
11110 c
= TREE_REAL_CST (arg01
);
11111 real_arithmetic (&c
, MINUS_EXPR
, &c
, &dconst1
);
11112 arg
= build_real (type
, c
);
11113 return build_call_expr (powfn
, 2, arg1
, arg
);
11117 /* Optimize a/root(b/c) into a*root(c/b). */
11118 if (BUILTIN_ROOT_P (fcode1
))
11120 tree rootarg
= CALL_EXPR_ARG (arg1
, 0);
11122 if (TREE_CODE (rootarg
) == RDIV_EXPR
)
11124 tree rootfn
= TREE_OPERAND (CALL_EXPR_FN (arg1
), 0);
11125 tree b
= TREE_OPERAND (rootarg
, 0);
11126 tree c
= TREE_OPERAND (rootarg
, 1);
11128 tree tmp
= fold_build2 (RDIV_EXPR
, type
, c
, b
);
11130 tmp
= build_call_expr (rootfn
, 1, tmp
);
11131 return fold_build2 (MULT_EXPR
, type
, arg0
, tmp
);
11135 /* Optimize x/expN(y) into x*expN(-y). */
11136 if (BUILTIN_EXPONENT_P (fcode1
))
11138 tree expfn
= TREE_OPERAND (CALL_EXPR_FN (arg1
), 0);
11139 tree arg
= negate_expr (CALL_EXPR_ARG (arg1
, 0));
11140 arg1
= build_call_expr (expfn
, 1, fold_convert (type
, arg
));
11141 return fold_build2 (MULT_EXPR
, type
, arg0
, arg1
);
11144 /* Optimize x/pow(y,z) into x*pow(y,-z). */
11145 if (fcode1
== BUILT_IN_POW
11146 || fcode1
== BUILT_IN_POWF
11147 || fcode1
== BUILT_IN_POWL
)
11149 tree powfn
= TREE_OPERAND (CALL_EXPR_FN (arg1
), 0);
11150 tree arg10
= CALL_EXPR_ARG (arg1
, 0);
11151 tree arg11
= CALL_EXPR_ARG (arg1
, 1);
11152 tree neg11
= fold_convert (type
, negate_expr (arg11
));
11153 arg1
= build_call_expr (powfn
, 2, arg10
, neg11
);
11154 return fold_build2 (MULT_EXPR
, type
, arg0
, arg1
);
11159 case TRUNC_DIV_EXPR
:
11160 case FLOOR_DIV_EXPR
:
11161 /* Simplify A / (B << N) where A and B are positive and B is
11162 a power of 2, to A >> (N + log2(B)). */
11163 strict_overflow_p
= false;
11164 if (TREE_CODE (arg1
) == LSHIFT_EXPR
11165 && (TYPE_UNSIGNED (type
)
11166 || tree_expr_nonnegative_warnv_p (arg0
, &strict_overflow_p
)))
11168 tree sval
= TREE_OPERAND (arg1
, 0);
11169 if (integer_pow2p (sval
) && tree_int_cst_sgn (sval
) > 0)
11171 tree sh_cnt
= TREE_OPERAND (arg1
, 1);
11172 unsigned long pow2
= exact_log2 (TREE_INT_CST_LOW (sval
));
11174 if (strict_overflow_p
)
11175 fold_overflow_warning (("assuming signed overflow does not "
11176 "occur when simplifying A / (B << N)"),
11177 WARN_STRICT_OVERFLOW_MISC
);
11179 sh_cnt
= fold_build2 (PLUS_EXPR
, TREE_TYPE (sh_cnt
),
11180 sh_cnt
, build_int_cst (NULL_TREE
, pow2
));
11181 return fold_build2 (RSHIFT_EXPR
, type
,
11182 fold_convert (type
, arg0
), sh_cnt
);
11187 case ROUND_DIV_EXPR
:
11188 case CEIL_DIV_EXPR
:
11189 case EXACT_DIV_EXPR
:
11190 if (integer_onep (arg1
))
11191 return non_lvalue (fold_convert (type
, arg0
));
11192 if (integer_zerop (arg1
))
11194 /* X / -1 is -X. */
11195 if (!TYPE_UNSIGNED (type
)
11196 && TREE_CODE (arg1
) == INTEGER_CST
11197 && TREE_INT_CST_LOW (arg1
) == (unsigned HOST_WIDE_INT
) -1
11198 && TREE_INT_CST_HIGH (arg1
) == -1)
11199 return fold_convert (type
, negate_expr (arg0
));
11201 /* Convert -A / -B to A / B when the type is signed and overflow is
11203 if ((!INTEGRAL_TYPE_P (type
) || TYPE_OVERFLOW_UNDEFINED (type
))
11204 && TREE_CODE (arg0
) == NEGATE_EXPR
11205 && negate_expr_p (arg1
))
11207 if (INTEGRAL_TYPE_P (type
))
11208 fold_overflow_warning (("assuming signed overflow does not occur "
11209 "when distributing negation across "
11211 WARN_STRICT_OVERFLOW_MISC
);
11212 return fold_build2 (code
, type
,
11213 fold_convert (type
, TREE_OPERAND (arg0
, 0)),
11214 negate_expr (arg1
));
11216 if ((!INTEGRAL_TYPE_P (type
) || TYPE_OVERFLOW_UNDEFINED (type
))
11217 && TREE_CODE (arg1
) == NEGATE_EXPR
11218 && negate_expr_p (arg0
))
11220 if (INTEGRAL_TYPE_P (type
))
11221 fold_overflow_warning (("assuming signed overflow does not occur "
11222 "when distributing negation across "
11224 WARN_STRICT_OVERFLOW_MISC
);
11225 return fold_build2 (code
, type
, negate_expr (arg0
),
11226 TREE_OPERAND (arg1
, 0));
11229 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
11230 operation, EXACT_DIV_EXPR.
11232 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
11233 At one time others generated faster code, it's not clear if they do
11234 after the last round to changes to the DIV code in expmed.c. */
11235 if ((code
== CEIL_DIV_EXPR
|| code
== FLOOR_DIV_EXPR
)
11236 && multiple_of_p (type
, arg0
, arg1
))
11237 return fold_build2 (EXACT_DIV_EXPR
, type
, arg0
, arg1
);
11239 strict_overflow_p
= false;
11240 if (TREE_CODE (arg1
) == INTEGER_CST
11241 && 0 != (tem
= extract_muldiv (op0
, arg1
, code
, NULL_TREE
,
11242 &strict_overflow_p
)))
11244 if (strict_overflow_p
)
11245 fold_overflow_warning (("assuming signed overflow does not occur "
11246 "when simplifying division"),
11247 WARN_STRICT_OVERFLOW_MISC
);
11248 return fold_convert (type
, tem
);
11253 case CEIL_MOD_EXPR
:
11254 case FLOOR_MOD_EXPR
:
11255 case ROUND_MOD_EXPR
:
11256 case TRUNC_MOD_EXPR
:
11257 /* X % 1 is always zero, but be sure to preserve any side
11259 if (integer_onep (arg1
))
11260 return omit_one_operand (type
, integer_zero_node
, arg0
);
11262 /* X % 0, return X % 0 unchanged so that we can get the
11263 proper warnings and errors. */
11264 if (integer_zerop (arg1
))
11267 /* 0 % X is always zero, but be sure to preserve any side
11268 effects in X. Place this after checking for X == 0. */
11269 if (integer_zerop (arg0
))
11270 return omit_one_operand (type
, integer_zero_node
, arg1
);
11272 /* X % -1 is zero. */
11273 if (!TYPE_UNSIGNED (type
)
11274 && TREE_CODE (arg1
) == INTEGER_CST
11275 && TREE_INT_CST_LOW (arg1
) == (unsigned HOST_WIDE_INT
) -1
11276 && TREE_INT_CST_HIGH (arg1
) == -1)
11277 return omit_one_operand (type
, integer_zero_node
, arg0
);
11279 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
11280 i.e. "X % C" into "X & (C - 1)", if X and C are positive. */
11281 strict_overflow_p
= false;
11282 if ((code
== TRUNC_MOD_EXPR
|| code
== FLOOR_MOD_EXPR
)
11283 && (TYPE_UNSIGNED (type
)
11284 || tree_expr_nonnegative_warnv_p (arg0
, &strict_overflow_p
)))
11287 /* Also optimize A % (C << N) where C is a power of 2,
11288 to A & ((C << N) - 1). */
11289 if (TREE_CODE (arg1
) == LSHIFT_EXPR
)
11290 c
= TREE_OPERAND (arg1
, 0);
11292 if (integer_pow2p (c
) && tree_int_cst_sgn (c
) > 0)
11294 tree mask
= fold_build2 (MINUS_EXPR
, TREE_TYPE (arg1
), arg1
,
11295 build_int_cst (TREE_TYPE (arg1
), 1));
11296 if (strict_overflow_p
)
11297 fold_overflow_warning (("assuming signed overflow does not "
11298 "occur when simplifying "
11299 "X % (power of two)"),
11300 WARN_STRICT_OVERFLOW_MISC
);
11301 return fold_build2 (BIT_AND_EXPR
, type
,
11302 fold_convert (type
, arg0
),
11303 fold_convert (type
, mask
));
11307 /* X % -C is the same as X % C. */
11308 if (code
== TRUNC_MOD_EXPR
11309 && !TYPE_UNSIGNED (type
)
11310 && TREE_CODE (arg1
) == INTEGER_CST
11311 && !TREE_OVERFLOW (arg1
)
11312 && TREE_INT_CST_HIGH (arg1
) < 0
11313 && !TYPE_OVERFLOW_TRAPS (type
)
11314 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
11315 && !sign_bit_p (arg1
, arg1
))
11316 return fold_build2 (code
, type
, fold_convert (type
, arg0
),
11317 fold_convert (type
, negate_expr (arg1
)));
11319 /* X % -Y is the same as X % Y. */
11320 if (code
== TRUNC_MOD_EXPR
11321 && !TYPE_UNSIGNED (type
)
11322 && TREE_CODE (arg1
) == NEGATE_EXPR
11323 && !TYPE_OVERFLOW_TRAPS (type
))
11324 return fold_build2 (code
, type
, fold_convert (type
, arg0
),
11325 fold_convert (type
, TREE_OPERAND (arg1
, 0)));
11327 if (TREE_CODE (arg1
) == INTEGER_CST
11328 && 0 != (tem
= extract_muldiv (op0
, arg1
, code
, NULL_TREE
,
11329 &strict_overflow_p
)))
11331 if (strict_overflow_p
)
11332 fold_overflow_warning (("assuming signed overflow does not occur "
11333 "when simplifying modulos"),
11334 WARN_STRICT_OVERFLOW_MISC
);
11335 return fold_convert (type
, tem
);
11342 if (integer_all_onesp (arg0
))
11343 return omit_one_operand (type
, arg0
, arg1
);
11347 /* Optimize -1 >> x for arithmetic right shifts. */
11348 if (integer_all_onesp (arg0
) && !TYPE_UNSIGNED (type
))
11349 return omit_one_operand (type
, arg0
, arg1
);
11350 /* ... fall through ... */
11354 if (integer_zerop (arg1
))
11355 return non_lvalue (fold_convert (type
, arg0
));
11356 if (integer_zerop (arg0
))
11357 return omit_one_operand (type
, arg0
, arg1
);
11359 /* Since negative shift count is not well-defined,
11360 don't try to compute it in the compiler. */
11361 if (TREE_CODE (arg1
) == INTEGER_CST
&& tree_int_cst_sgn (arg1
) < 0)
11364 /* Turn (a OP c1) OP c2 into a OP (c1+c2). */
11365 if (TREE_CODE (op0
) == code
&& host_integerp (arg1
, false)
11366 && TREE_INT_CST_LOW (arg1
) < TYPE_PRECISION (type
)
11367 && host_integerp (TREE_OPERAND (arg0
, 1), false)
11368 && TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1)) < TYPE_PRECISION (type
))
11370 HOST_WIDE_INT low
= (TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1))
11371 + TREE_INT_CST_LOW (arg1
));
11373 /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
11374 being well defined. */
11375 if (low
>= TYPE_PRECISION (type
))
11377 if (code
== LROTATE_EXPR
|| code
== RROTATE_EXPR
)
11378 low
= low
% TYPE_PRECISION (type
);
11379 else if (TYPE_UNSIGNED (type
) || code
== LSHIFT_EXPR
)
11380 return build_int_cst (type
, 0);
11382 low
= TYPE_PRECISION (type
) - 1;
11385 return fold_build2 (code
, type
, TREE_OPERAND (arg0
, 0),
11386 build_int_cst (type
, low
));
11389 /* Transform (x >> c) << c into x & (-1<<c), or transform (x << c) >> c
11390 into x & ((unsigned)-1 >> c) for unsigned types. */
11391 if (((code
== LSHIFT_EXPR
&& TREE_CODE (arg0
) == RSHIFT_EXPR
)
11392 || (TYPE_UNSIGNED (type
)
11393 && code
== RSHIFT_EXPR
&& TREE_CODE (arg0
) == LSHIFT_EXPR
))
11394 && host_integerp (arg1
, false)
11395 && TREE_INT_CST_LOW (arg1
) < TYPE_PRECISION (type
)
11396 && host_integerp (TREE_OPERAND (arg0
, 1), false)
11397 && TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1)) < TYPE_PRECISION (type
))
11399 HOST_WIDE_INT low0
= TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1));
11400 HOST_WIDE_INT low1
= TREE_INT_CST_LOW (arg1
);
11406 arg00
= fold_convert (type
, TREE_OPERAND (arg0
, 0));
11408 lshift
= build_int_cst (type
, -1);
11409 lshift
= int_const_binop (code
, lshift
, arg1
, 0);
11411 return fold_build2 (BIT_AND_EXPR
, type
, arg00
, lshift
);
11415 /* Rewrite an LROTATE_EXPR by a constant into an
11416 RROTATE_EXPR by a new constant. */
11417 if (code
== LROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
)
11419 tree tem
= build_int_cst (TREE_TYPE (arg1
),
11420 GET_MODE_BITSIZE (TYPE_MODE (type
)));
11421 tem
= const_binop (MINUS_EXPR
, tem
, arg1
, 0);
11422 return fold_build2 (RROTATE_EXPR
, type
, arg0
, tem
);
11425 /* If we have a rotate of a bit operation with the rotate count and
11426 the second operand of the bit operation both constant,
11427 permute the two operations. */
11428 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
11429 && (TREE_CODE (arg0
) == BIT_AND_EXPR
11430 || TREE_CODE (arg0
) == BIT_IOR_EXPR
11431 || TREE_CODE (arg0
) == BIT_XOR_EXPR
)
11432 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
11433 return fold_build2 (TREE_CODE (arg0
), type
,
11434 fold_build2 (code
, type
,
11435 TREE_OPERAND (arg0
, 0), arg1
),
11436 fold_build2 (code
, type
,
11437 TREE_OPERAND (arg0
, 1), arg1
));
11439 /* Two consecutive rotates adding up to the width of the mode can
11441 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
11442 && TREE_CODE (arg0
) == RROTATE_EXPR
11443 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
11444 && TREE_INT_CST_HIGH (arg1
) == 0
11445 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0
, 1)) == 0
11446 && ((TREE_INT_CST_LOW (arg1
)
11447 + TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1)))
11448 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type
))))
11449 return TREE_OPERAND (arg0
, 0);
11454 if (operand_equal_p (arg0
, arg1
, 0))
11455 return omit_one_operand (type
, arg0
, arg1
);
11456 if (INTEGRAL_TYPE_P (type
)
11457 && operand_equal_p (arg1
, TYPE_MIN_VALUE (type
), OEP_ONLY_CONST
))
11458 return omit_one_operand (type
, arg1
, arg0
);
11459 tem
= fold_minmax (MIN_EXPR
, type
, arg0
, arg1
);
11465 if (operand_equal_p (arg0
, arg1
, 0))
11466 return omit_one_operand (type
, arg0
, arg1
);
11467 if (INTEGRAL_TYPE_P (type
)
11468 && TYPE_MAX_VALUE (type
)
11469 && operand_equal_p (arg1
, TYPE_MAX_VALUE (type
), OEP_ONLY_CONST
))
11470 return omit_one_operand (type
, arg1
, arg0
);
11471 tem
= fold_minmax (MAX_EXPR
, type
, arg0
, arg1
);
11476 case TRUTH_ANDIF_EXPR
:
11477 /* Note that the operands of this must be ints
11478 and their values must be 0 or 1.
11479 ("true" is a fixed value perhaps depending on the language.) */
11480 /* If first arg is constant zero, return it. */
11481 if (integer_zerop (arg0
))
11482 return fold_convert (type
, arg0
);
11483 case TRUTH_AND_EXPR
:
11484 /* If either arg is constant true, drop it. */
11485 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
11486 return non_lvalue (fold_convert (type
, arg1
));
11487 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
)
11488 /* Preserve sequence points. */
11489 && (code
!= TRUTH_ANDIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
11490 return non_lvalue (fold_convert (type
, arg0
));
11491 /* If second arg is constant zero, result is zero, but first arg
11492 must be evaluated. */
11493 if (integer_zerop (arg1
))
11494 return omit_one_operand (type
, arg1
, arg0
);
11495 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
11496 case will be handled here. */
11497 if (integer_zerop (arg0
))
11498 return omit_one_operand (type
, arg0
, arg1
);
11500 /* !X && X is always false. */
11501 if (TREE_CODE (arg0
) == TRUTH_NOT_EXPR
11502 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
11503 return omit_one_operand (type
, integer_zero_node
, arg1
);
11504 /* X && !X is always false. */
11505 if (TREE_CODE (arg1
) == TRUTH_NOT_EXPR
11506 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
11507 return omit_one_operand (type
, integer_zero_node
, arg0
);
11509 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
11510 means A >= Y && A != MAX, but in this case we know that
11513 if (!TREE_SIDE_EFFECTS (arg0
)
11514 && !TREE_SIDE_EFFECTS (arg1
))
11516 tem
= fold_to_nonsharp_ineq_using_bound (arg0
, arg1
);
11517 if (tem
&& !operand_equal_p (tem
, arg0
, 0))
11518 return fold_build2 (code
, type
, tem
, arg1
);
11520 tem
= fold_to_nonsharp_ineq_using_bound (arg1
, arg0
);
11521 if (tem
&& !operand_equal_p (tem
, arg1
, 0))
11522 return fold_build2 (code
, type
, arg0
, tem
);
11526 /* We only do these simplifications if we are optimizing. */
11530 /* Check for things like (A || B) && (A || C). We can convert this
11531 to A || (B && C). Note that either operator can be any of the four
11532 truth and/or operations and the transformation will still be
11533 valid. Also note that we only care about order for the
11534 ANDIF and ORIF operators. If B contains side effects, this
11535 might change the truth-value of A. */
11536 if (TREE_CODE (arg0
) == TREE_CODE (arg1
)
11537 && (TREE_CODE (arg0
) == TRUTH_ANDIF_EXPR
11538 || TREE_CODE (arg0
) == TRUTH_ORIF_EXPR
11539 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
11540 || TREE_CODE (arg0
) == TRUTH_OR_EXPR
)
11541 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0
, 1)))
11543 tree a00
= TREE_OPERAND (arg0
, 0);
11544 tree a01
= TREE_OPERAND (arg0
, 1);
11545 tree a10
= TREE_OPERAND (arg1
, 0);
11546 tree a11
= TREE_OPERAND (arg1
, 1);
11547 int commutative
= ((TREE_CODE (arg0
) == TRUTH_OR_EXPR
11548 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
)
11549 && (code
== TRUTH_AND_EXPR
11550 || code
== TRUTH_OR_EXPR
));
11552 if (operand_equal_p (a00
, a10
, 0))
11553 return fold_build2 (TREE_CODE (arg0
), type
, a00
,
11554 fold_build2 (code
, type
, a01
, a11
));
11555 else if (commutative
&& operand_equal_p (a00
, a11
, 0))
11556 return fold_build2 (TREE_CODE (arg0
), type
, a00
,
11557 fold_build2 (code
, type
, a01
, a10
));
11558 else if (commutative
&& operand_equal_p (a01
, a10
, 0))
11559 return fold_build2 (TREE_CODE (arg0
), type
, a01
,
11560 fold_build2 (code
, type
, a00
, a11
));
11562 /* This case if tricky because we must either have commutative
11563 operators or else A10 must not have side-effects. */
11565 else if ((commutative
|| ! TREE_SIDE_EFFECTS (a10
))
11566 && operand_equal_p (a01
, a11
, 0))
11567 return fold_build2 (TREE_CODE (arg0
), type
,
11568 fold_build2 (code
, type
, a00
, a10
),
11572 /* See if we can build a range comparison. */
11573 if (0 != (tem
= fold_range_test (code
, type
, op0
, op1
)))
11576 /* Check for the possibility of merging component references. If our
11577 lhs is another similar operation, try to merge its rhs with our
11578 rhs. Then try to merge our lhs and rhs. */
11579 if (TREE_CODE (arg0
) == code
11580 && 0 != (tem
= fold_truthop (code
, type
,
11581 TREE_OPERAND (arg0
, 1), arg1
)))
11582 return fold_build2 (code
, type
, TREE_OPERAND (arg0
, 0), tem
);
11584 if ((tem
= fold_truthop (code
, type
, arg0
, arg1
)) != 0)
11589 case TRUTH_ORIF_EXPR
:
11590 /* Note that the operands of this must be ints
11591 and their values must be 0 or true.
11592 ("true" is a fixed value perhaps depending on the language.) */
11593 /* If first arg is constant true, return it. */
11594 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
11595 return fold_convert (type
, arg0
);
11596 case TRUTH_OR_EXPR
:
11597 /* If either arg is constant zero, drop it. */
11598 if (TREE_CODE (arg0
) == INTEGER_CST
&& integer_zerop (arg0
))
11599 return non_lvalue (fold_convert (type
, arg1
));
11600 if (TREE_CODE (arg1
) == INTEGER_CST
&& integer_zerop (arg1
)
11601 /* Preserve sequence points. */
11602 && (code
!= TRUTH_ORIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
11603 return non_lvalue (fold_convert (type
, arg0
));
11604 /* If second arg is constant true, result is true, but we must
11605 evaluate first arg. */
11606 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
))
11607 return omit_one_operand (type
, arg1
, arg0
);
11608 /* Likewise for first arg, but note this only occurs here for
11610 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
11611 return omit_one_operand (type
, arg0
, arg1
);
11613 /* !X || X is always true. */
11614 if (TREE_CODE (arg0
) == TRUTH_NOT_EXPR
11615 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
11616 return omit_one_operand (type
, integer_one_node
, arg1
);
11617 /* X || !X is always true. */
11618 if (TREE_CODE (arg1
) == TRUTH_NOT_EXPR
11619 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
11620 return omit_one_operand (type
, integer_one_node
, arg0
);
11624 case TRUTH_XOR_EXPR
:
11625 /* If the second arg is constant zero, drop it. */
11626 if (integer_zerop (arg1
))
11627 return non_lvalue (fold_convert (type
, arg0
));
11628 /* If the second arg is constant true, this is a logical inversion. */
11629 if (integer_onep (arg1
))
11631 /* Only call invert_truthvalue if operand is a truth value. */
11632 if (TREE_CODE (TREE_TYPE (arg0
)) != BOOLEAN_TYPE
)
11633 tem
= fold_build1 (TRUTH_NOT_EXPR
, TREE_TYPE (arg0
), arg0
);
11635 tem
= invert_truthvalue (arg0
);
11636 return non_lvalue (fold_convert (type
, tem
));
11638 /* Identical arguments cancel to zero. */
11639 if (operand_equal_p (arg0
, arg1
, 0))
11640 return omit_one_operand (type
, integer_zero_node
, arg0
);
11642 /* !X ^ X is always true. */
11643 if (TREE_CODE (arg0
) == TRUTH_NOT_EXPR
11644 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
11645 return omit_one_operand (type
, integer_one_node
, arg1
);
11647 /* X ^ !X is always true. */
11648 if (TREE_CODE (arg1
) == TRUTH_NOT_EXPR
11649 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
11650 return omit_one_operand (type
, integer_one_node
, arg0
);
11656 tem
= fold_comparison (code
, type
, op0
, op1
);
11657 if (tem
!= NULL_TREE
)
11660 /* bool_var != 0 becomes bool_var. */
11661 if (TREE_CODE (TREE_TYPE (arg0
)) == BOOLEAN_TYPE
&& integer_zerop (arg1
)
11662 && code
== NE_EXPR
)
11663 return non_lvalue (fold_convert (type
, arg0
));
11665 /* bool_var == 1 becomes bool_var. */
11666 if (TREE_CODE (TREE_TYPE (arg0
)) == BOOLEAN_TYPE
&& integer_onep (arg1
)
11667 && code
== EQ_EXPR
)
11668 return non_lvalue (fold_convert (type
, arg0
));
11670 /* bool_var != 1 becomes !bool_var. */
11671 if (TREE_CODE (TREE_TYPE (arg0
)) == BOOLEAN_TYPE
&& integer_onep (arg1
)
11672 && code
== NE_EXPR
)
11673 return fold_build1 (TRUTH_NOT_EXPR
, type
, arg0
);
11675 /* bool_var == 0 becomes !bool_var. */
11676 if (TREE_CODE (TREE_TYPE (arg0
)) == BOOLEAN_TYPE
&& integer_zerop (arg1
)
11677 && code
== EQ_EXPR
)
11678 return fold_build1 (TRUTH_NOT_EXPR
, type
, arg0
);
11680 /* If this is an equality comparison of the address of two non-weak,
11681 unaliased symbols neither of which are extern (since we do not
11682 have access to attributes for externs), then we know the result. */
11683 if (TREE_CODE (arg0
) == ADDR_EXPR
11684 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0
, 0))
11685 && ! DECL_WEAK (TREE_OPERAND (arg0
, 0))
11686 && ! lookup_attribute ("alias",
11687 DECL_ATTRIBUTES (TREE_OPERAND (arg0
, 0)))
11688 && ! DECL_EXTERNAL (TREE_OPERAND (arg0
, 0))
11689 && TREE_CODE (arg1
) == ADDR_EXPR
11690 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg1
, 0))
11691 && ! DECL_WEAK (TREE_OPERAND (arg1
, 0))
11692 && ! lookup_attribute ("alias",
11693 DECL_ATTRIBUTES (TREE_OPERAND (arg1
, 0)))
11694 && ! DECL_EXTERNAL (TREE_OPERAND (arg1
, 0)))
11696 /* We know that we're looking at the address of two
11697 non-weak, unaliased, static _DECL nodes.
11699 It is both wasteful and incorrect to call operand_equal_p
11700 to compare the two ADDR_EXPR nodes. It is wasteful in that
11701 all we need to do is test pointer equality for the arguments
11702 to the two ADDR_EXPR nodes. It is incorrect to use
11703 operand_equal_p as that function is NOT equivalent to a
11704 C equality test. It can in fact return false for two
11705 objects which would test as equal using the C equality
11707 bool equal
= TREE_OPERAND (arg0
, 0) == TREE_OPERAND (arg1
, 0);
11708 return constant_boolean_node (equal
11709 ? code
== EQ_EXPR
: code
!= EQ_EXPR
,
11713 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
11714 a MINUS_EXPR of a constant, we can convert it into a comparison with
11715 a revised constant as long as no overflow occurs. */
11716 if (TREE_CODE (arg1
) == INTEGER_CST
11717 && (TREE_CODE (arg0
) == PLUS_EXPR
11718 || TREE_CODE (arg0
) == MINUS_EXPR
)
11719 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
11720 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
11721 ? MINUS_EXPR
: PLUS_EXPR
,
11722 fold_convert (TREE_TYPE (arg0
), arg1
),
11723 TREE_OPERAND (arg0
, 1), 0))
11724 && !TREE_OVERFLOW (tem
))
11725 return fold_build2 (code
, type
, TREE_OPERAND (arg0
, 0), tem
);
11727 /* Similarly for a NEGATE_EXPR. */
11728 if (TREE_CODE (arg0
) == NEGATE_EXPR
11729 && TREE_CODE (arg1
) == INTEGER_CST
11730 && 0 != (tem
= negate_expr (arg1
))
11731 && TREE_CODE (tem
) == INTEGER_CST
11732 && !TREE_OVERFLOW (tem
))
11733 return fold_build2 (code
, type
, TREE_OPERAND (arg0
, 0), tem
);
11735 /* Similarly for a BIT_XOR_EXPR; X ^ C1 == C2 is X == (C1 ^ C2). */
11736 if (TREE_CODE (arg0
) == BIT_XOR_EXPR
11737 && TREE_CODE (arg1
) == INTEGER_CST
11738 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
11739 return fold_build2 (code
, type
, TREE_OPERAND (arg0
, 0),
11740 fold_build2 (BIT_XOR_EXPR
, TREE_TYPE (arg0
),
11741 fold_convert (TREE_TYPE (arg0
), arg1
),
11742 TREE_OPERAND (arg0
, 1)));
11744 /* Transform comparisons of the form X +- C CMP X. */
11745 if ((TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
11746 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0)
11747 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
11748 && (INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
11749 || POINTER_TYPE_P (TREE_TYPE (arg0
))))
11751 tree cst
= TREE_OPERAND (arg0
, 1);
11753 if (code
== EQ_EXPR
11754 && !integer_zerop (cst
))
11755 return omit_two_operands (type
, boolean_false_node
,
11756 TREE_OPERAND (arg0
, 0), arg1
);
11758 return omit_two_operands (type
, boolean_true_node
,
11759 TREE_OPERAND (arg0
, 0), arg1
);
11762 /* If we have X - Y == 0, we can convert that to X == Y and similarly
11763 for !=. Don't do this for ordered comparisons due to overflow. */
11764 if (TREE_CODE (arg0
) == MINUS_EXPR
11765 && integer_zerop (arg1
))
11766 return fold_build2 (code
, type
,
11767 TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg0
, 1));
11769 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
11770 if (TREE_CODE (arg0
) == ABS_EXPR
11771 && (integer_zerop (arg1
) || real_zerop (arg1
)))
11772 return fold_build2 (code
, type
, TREE_OPERAND (arg0
, 0), arg1
);
11774 /* If this is an EQ or NE comparison with zero and ARG0 is
11775 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
11776 two operations, but the latter can be done in one less insn
11777 on machines that have only two-operand insns or on which a
11778 constant cannot be the first operand. */
11779 if (TREE_CODE (arg0
) == BIT_AND_EXPR
11780 && integer_zerop (arg1
))
11782 tree arg00
= TREE_OPERAND (arg0
, 0);
11783 tree arg01
= TREE_OPERAND (arg0
, 1);
11784 if (TREE_CODE (arg00
) == LSHIFT_EXPR
11785 && integer_onep (TREE_OPERAND (arg00
, 0)))
11787 fold_build2 (code
, type
,
11788 build2 (BIT_AND_EXPR
, TREE_TYPE (arg0
),
11789 build2 (RSHIFT_EXPR
, TREE_TYPE (arg00
),
11790 arg01
, TREE_OPERAND (arg00
, 1)),
11791 fold_convert (TREE_TYPE (arg0
),
11792 integer_one_node
)),
11794 else if (TREE_CODE (TREE_OPERAND (arg0
, 1)) == LSHIFT_EXPR
11795 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 1), 0)))
11797 fold_build2 (code
, type
,
11798 build2 (BIT_AND_EXPR
, TREE_TYPE (arg0
),
11799 build2 (RSHIFT_EXPR
, TREE_TYPE (arg01
),
11800 arg00
, TREE_OPERAND (arg01
, 1)),
11801 fold_convert (TREE_TYPE (arg0
),
11802 integer_one_node
)),
11806 /* If this is an NE or EQ comparison of zero against the result of a
11807 signed MOD operation whose second operand is a power of 2, make
11808 the MOD operation unsigned since it is simpler and equivalent. */
11809 if (integer_zerop (arg1
)
11810 && !TYPE_UNSIGNED (TREE_TYPE (arg0
))
11811 && (TREE_CODE (arg0
) == TRUNC_MOD_EXPR
11812 || TREE_CODE (arg0
) == CEIL_MOD_EXPR
11813 || TREE_CODE (arg0
) == FLOOR_MOD_EXPR
11814 || TREE_CODE (arg0
) == ROUND_MOD_EXPR
)
11815 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
11817 tree newtype
= unsigned_type_for (TREE_TYPE (arg0
));
11818 tree newmod
= fold_build2 (TREE_CODE (arg0
), newtype
,
11819 fold_convert (newtype
,
11820 TREE_OPERAND (arg0
, 0)),
11821 fold_convert (newtype
,
11822 TREE_OPERAND (arg0
, 1)));
11824 return fold_build2 (code
, type
, newmod
,
11825 fold_convert (newtype
, arg1
));
11828 /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
11829 C1 is a valid shift constant, and C2 is a power of two, i.e.
11831 if (TREE_CODE (arg0
) == BIT_AND_EXPR
11832 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == RSHIFT_EXPR
11833 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1))
11835 && integer_pow2p (TREE_OPERAND (arg0
, 1))
11836 && integer_zerop (arg1
))
11838 tree itype
= TREE_TYPE (arg0
);
11839 unsigned HOST_WIDE_INT prec
= TYPE_PRECISION (itype
);
11840 tree arg001
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1);
11842 /* Check for a valid shift count. */
11843 if (TREE_INT_CST_HIGH (arg001
) == 0
11844 && TREE_INT_CST_LOW (arg001
) < prec
)
11846 tree arg01
= TREE_OPERAND (arg0
, 1);
11847 tree arg000
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
11848 unsigned HOST_WIDE_INT log2
= tree_log2 (arg01
);
11849 /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
11850 can be rewritten as (X & (C2 << C1)) != 0. */
11851 if ((log2
+ TREE_INT_CST_LOW (arg001
)) < prec
)
11853 tem
= fold_build2 (LSHIFT_EXPR
, itype
, arg01
, arg001
);
11854 tem
= fold_build2 (BIT_AND_EXPR
, itype
, arg000
, tem
);
11855 return fold_build2 (code
, type
, tem
, arg1
);
11857 /* Otherwise, for signed (arithmetic) shifts,
11858 ((X >> C1) & C2) != 0 is rewritten as X < 0, and
11859 ((X >> C1) & C2) == 0 is rewritten as X >= 0. */
11860 else if (!TYPE_UNSIGNED (itype
))
11861 return fold_build2 (code
== EQ_EXPR
? GE_EXPR
: LT_EXPR
, type
,
11862 arg000
, build_int_cst (itype
, 0));
11863 /* Otherwise, of unsigned (logical) shifts,
11864 ((X >> C1) & C2) != 0 is rewritten as (X,false), and
11865 ((X >> C1) & C2) == 0 is rewritten as (X,true). */
11867 return omit_one_operand (type
,
11868 code
== EQ_EXPR
? integer_one_node
11869 : integer_zero_node
,
11874 /* If this is an NE comparison of zero with an AND of one, remove the
11875 comparison since the AND will give the correct value. */
11876 if (code
== NE_EXPR
11877 && integer_zerop (arg1
)
11878 && TREE_CODE (arg0
) == BIT_AND_EXPR
11879 && integer_onep (TREE_OPERAND (arg0
, 1)))
11880 return fold_convert (type
, arg0
);
11882 /* If we have (A & C) == C where C is a power of 2, convert this into
11883 (A & C) != 0. Similarly for NE_EXPR. */
11884 if (TREE_CODE (arg0
) == BIT_AND_EXPR
11885 && integer_pow2p (TREE_OPERAND (arg0
, 1))
11886 && operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
11887 return fold_build2 (code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
, type
,
11888 arg0
, fold_convert (TREE_TYPE (arg0
),
11889 integer_zero_node
));
11891 /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
11892 bit, then fold the expression into A < 0 or A >= 0. */
11893 tem
= fold_single_bit_test_into_sign_test (code
, arg0
, arg1
, type
);
11897 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
11898 Similarly for NE_EXPR. */
11899 if (TREE_CODE (arg0
) == BIT_AND_EXPR
11900 && TREE_CODE (arg1
) == INTEGER_CST
11901 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
11903 tree notc
= fold_build1 (BIT_NOT_EXPR
,
11904 TREE_TYPE (TREE_OPERAND (arg0
, 1)),
11905 TREE_OPERAND (arg0
, 1));
11906 tree dandnotc
= fold_build2 (BIT_AND_EXPR
, TREE_TYPE (arg0
),
11908 tree rslt
= code
== EQ_EXPR
? integer_zero_node
: integer_one_node
;
11909 if (integer_nonzerop (dandnotc
))
11910 return omit_one_operand (type
, rslt
, arg0
);
11913 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
11914 Similarly for NE_EXPR. */
11915 if (TREE_CODE (arg0
) == BIT_IOR_EXPR
11916 && TREE_CODE (arg1
) == INTEGER_CST
11917 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
11919 tree notd
= fold_build1 (BIT_NOT_EXPR
, TREE_TYPE (arg1
), arg1
);
11920 tree candnotd
= fold_build2 (BIT_AND_EXPR
, TREE_TYPE (arg0
),
11921 TREE_OPERAND (arg0
, 1), notd
);
11922 tree rslt
= code
== EQ_EXPR
? integer_zero_node
: integer_one_node
;
11923 if (integer_nonzerop (candnotd
))
11924 return omit_one_operand (type
, rslt
, arg0
);
11927 /* If this is a comparison of a field, we may be able to simplify it. */
11928 if ((TREE_CODE (arg0
) == COMPONENT_REF
11929 || TREE_CODE (arg0
) == BIT_FIELD_REF
)
11930 /* Handle the constant case even without -O
11931 to make sure the warnings are given. */
11932 && (optimize
|| TREE_CODE (arg1
) == INTEGER_CST
))
11934 t1
= optimize_bit_field_compare (code
, type
, arg0
, arg1
);
11939 /* Optimize comparisons of strlen vs zero to a compare of the
11940 first character of the string vs zero. To wit,
11941 strlen(ptr) == 0 => *ptr == 0
11942 strlen(ptr) != 0 => *ptr != 0
11943 Other cases should reduce to one of these two (or a constant)
11944 due to the return value of strlen being unsigned. */
11945 if (TREE_CODE (arg0
) == CALL_EXPR
11946 && integer_zerop (arg1
))
11948 tree fndecl
= get_callee_fndecl (arg0
);
11951 && DECL_BUILT_IN_CLASS (fndecl
) == BUILT_IN_NORMAL
11952 && DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STRLEN
11953 && call_expr_nargs (arg0
) == 1
11954 && TREE_CODE (TREE_TYPE (CALL_EXPR_ARG (arg0
, 0))) == POINTER_TYPE
)
11956 tree iref
= build_fold_indirect_ref (CALL_EXPR_ARG (arg0
, 0));
11957 return fold_build2 (code
, type
, iref
,
11958 build_int_cst (TREE_TYPE (iref
), 0));
11962 /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
11963 of X. Similarly fold (X >> C) == 0 into X >= 0. */
11964 if (TREE_CODE (arg0
) == RSHIFT_EXPR
11965 && integer_zerop (arg1
)
11966 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
11968 tree arg00
= TREE_OPERAND (arg0
, 0);
11969 tree arg01
= TREE_OPERAND (arg0
, 1);
11970 tree itype
= TREE_TYPE (arg00
);
11971 if (TREE_INT_CST_HIGH (arg01
) == 0
11972 && TREE_INT_CST_LOW (arg01
)
11973 == (unsigned HOST_WIDE_INT
) (TYPE_PRECISION (itype
) - 1))
11975 if (TYPE_UNSIGNED (itype
))
11977 itype
= signed_type_for (itype
);
11978 arg00
= fold_convert (itype
, arg00
);
11980 return fold_build2 (code
== EQ_EXPR
? GE_EXPR
: LT_EXPR
,
11981 type
, arg00
, build_int_cst (itype
, 0));
11985 /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y. */
11986 if (integer_zerop (arg1
)
11987 && TREE_CODE (arg0
) == BIT_XOR_EXPR
)
11988 return fold_build2 (code
, type
, TREE_OPERAND (arg0
, 0),
11989 TREE_OPERAND (arg0
, 1));
11991 /* (X ^ Y) == Y becomes X == 0. We know that Y has no side-effects. */
11992 if (TREE_CODE (arg0
) == BIT_XOR_EXPR
11993 && operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
11994 return fold_build2 (code
, type
, TREE_OPERAND (arg0
, 0),
11995 build_int_cst (TREE_TYPE (arg1
), 0));
11996 /* Likewise (X ^ Y) == X becomes Y == 0. X has no side-effects. */
11997 if (TREE_CODE (arg0
) == BIT_XOR_EXPR
11998 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0)
11999 && reorder_operands_p (TREE_OPERAND (arg0
, 1), arg1
))
12000 return fold_build2 (code
, type
, TREE_OPERAND (arg0
, 1),
12001 build_int_cst (TREE_TYPE (arg1
), 0));
12003 /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2). */
12004 if (TREE_CODE (arg0
) == BIT_XOR_EXPR
12005 && TREE_CODE (arg1
) == INTEGER_CST
12006 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
12007 return fold_build2 (code
, type
, TREE_OPERAND (arg0
, 0),
12008 fold_build2 (BIT_XOR_EXPR
, TREE_TYPE (arg1
),
12009 TREE_OPERAND (arg0
, 1), arg1
));
12011 /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
12012 (X & C) == 0 when C is a single bit. */
12013 if (TREE_CODE (arg0
) == BIT_AND_EXPR
12014 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == BIT_NOT_EXPR
12015 && integer_zerop (arg1
)
12016 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
12018 tem
= fold_build2 (BIT_AND_EXPR
, TREE_TYPE (arg0
),
12019 TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0),
12020 TREE_OPERAND (arg0
, 1));
12021 return fold_build2 (code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
,
12025 /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
12026 constant C is a power of two, i.e. a single bit. */
12027 if (TREE_CODE (arg0
) == BIT_XOR_EXPR
12028 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == BIT_AND_EXPR
12029 && integer_zerop (arg1
)
12030 && integer_pow2p (TREE_OPERAND (arg0
, 1))
12031 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1),
12032 TREE_OPERAND (arg0
, 1), OEP_ONLY_CONST
))
12034 tree arg00
= TREE_OPERAND (arg0
, 0);
12035 return fold_build2 (code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
, type
,
12036 arg00
, build_int_cst (TREE_TYPE (arg00
), 0));
12039 /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
12040 when is C is a power of two, i.e. a single bit. */
12041 if (TREE_CODE (arg0
) == BIT_AND_EXPR
12042 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == BIT_XOR_EXPR
12043 && integer_zerop (arg1
)
12044 && integer_pow2p (TREE_OPERAND (arg0
, 1))
12045 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1),
12046 TREE_OPERAND (arg0
, 1), OEP_ONLY_CONST
))
12048 tree arg000
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
12049 tem
= fold_build2 (BIT_AND_EXPR
, TREE_TYPE (arg000
),
12050 arg000
, TREE_OPERAND (arg0
, 1));
12051 return fold_build2 (code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
, type
,
12052 tem
, build_int_cst (TREE_TYPE (tem
), 0));
12055 if (integer_zerop (arg1
)
12056 && tree_expr_nonzero_p (arg0
))
12058 tree res
= constant_boolean_node (code
==NE_EXPR
, type
);
12059 return omit_one_operand (type
, res
, arg0
);
12062 /* Fold -X op -Y as X op Y, where op is eq/ne. */
12063 if (TREE_CODE (arg0
) == NEGATE_EXPR
12064 && TREE_CODE (arg1
) == NEGATE_EXPR
)
12065 return fold_build2 (code
, type
,
12066 TREE_OPERAND (arg0
, 0),
12067 TREE_OPERAND (arg1
, 0));
12069 /* Fold (X & C) op (Y & C) as (X ^ Y) & C op 0", and symmetries. */
12070 if (TREE_CODE (arg0
) == BIT_AND_EXPR
12071 && TREE_CODE (arg1
) == BIT_AND_EXPR
)
12073 tree arg00
= TREE_OPERAND (arg0
, 0);
12074 tree arg01
= TREE_OPERAND (arg0
, 1);
12075 tree arg10
= TREE_OPERAND (arg1
, 0);
12076 tree arg11
= TREE_OPERAND (arg1
, 1);
12077 tree itype
= TREE_TYPE (arg0
);
12079 if (operand_equal_p (arg01
, arg11
, 0))
12080 return fold_build2 (code
, type
,
12081 fold_build2 (BIT_AND_EXPR
, itype
,
12082 fold_build2 (BIT_XOR_EXPR
, itype
,
12085 build_int_cst (itype
, 0));
12087 if (operand_equal_p (arg01
, arg10
, 0))
12088 return fold_build2 (code
, type
,
12089 fold_build2 (BIT_AND_EXPR
, itype
,
12090 fold_build2 (BIT_XOR_EXPR
, itype
,
12093 build_int_cst (itype
, 0));
12095 if (operand_equal_p (arg00
, arg11
, 0))
12096 return fold_build2 (code
, type
,
12097 fold_build2 (BIT_AND_EXPR
, itype
,
12098 fold_build2 (BIT_XOR_EXPR
, itype
,
12101 build_int_cst (itype
, 0));
12103 if (operand_equal_p (arg00
, arg10
, 0))
12104 return fold_build2 (code
, type
,
12105 fold_build2 (BIT_AND_EXPR
, itype
,
12106 fold_build2 (BIT_XOR_EXPR
, itype
,
12109 build_int_cst (itype
, 0));
12112 if (TREE_CODE (arg0
) == BIT_XOR_EXPR
12113 && TREE_CODE (arg1
) == BIT_XOR_EXPR
)
12115 tree arg00
= TREE_OPERAND (arg0
, 0);
12116 tree arg01
= TREE_OPERAND (arg0
, 1);
12117 tree arg10
= TREE_OPERAND (arg1
, 0);
12118 tree arg11
= TREE_OPERAND (arg1
, 1);
12119 tree itype
= TREE_TYPE (arg0
);
12121 /* Optimize (X ^ Z) op (Y ^ Z) as X op Y, and symmetries.
12122 operand_equal_p guarantees no side-effects so we don't need
12123 to use omit_one_operand on Z. */
12124 if (operand_equal_p (arg01
, arg11
, 0))
12125 return fold_build2 (code
, type
, arg00
, arg10
);
12126 if (operand_equal_p (arg01
, arg10
, 0))
12127 return fold_build2 (code
, type
, arg00
, arg11
);
12128 if (operand_equal_p (arg00
, arg11
, 0))
12129 return fold_build2 (code
, type
, arg01
, arg10
);
12130 if (operand_equal_p (arg00
, arg10
, 0))
12131 return fold_build2 (code
, type
, arg01
, arg11
);
12133 /* Optimize (X ^ C1) op (Y ^ C2) as (X ^ (C1 ^ C2)) op Y. */
12134 if (TREE_CODE (arg01
) == INTEGER_CST
12135 && TREE_CODE (arg11
) == INTEGER_CST
)
12136 return fold_build2 (code
, type
,
12137 fold_build2 (BIT_XOR_EXPR
, itype
, arg00
,
12138 fold_build2 (BIT_XOR_EXPR
, itype
,
12143 /* Attempt to simplify equality/inequality comparisons of complex
12144 values. Only lower the comparison if the result is known or
12145 can be simplified to a single scalar comparison. */
12146 if ((TREE_CODE (arg0
) == COMPLEX_EXPR
12147 || TREE_CODE (arg0
) == COMPLEX_CST
)
12148 && (TREE_CODE (arg1
) == COMPLEX_EXPR
12149 || TREE_CODE (arg1
) == COMPLEX_CST
))
12151 tree real0
, imag0
, real1
, imag1
;
12154 if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
12156 real0
= TREE_OPERAND (arg0
, 0);
12157 imag0
= TREE_OPERAND (arg0
, 1);
12161 real0
= TREE_REALPART (arg0
);
12162 imag0
= TREE_IMAGPART (arg0
);
12165 if (TREE_CODE (arg1
) == COMPLEX_EXPR
)
12167 real1
= TREE_OPERAND (arg1
, 0);
12168 imag1
= TREE_OPERAND (arg1
, 1);
12172 real1
= TREE_REALPART (arg1
);
12173 imag1
= TREE_IMAGPART (arg1
);
12176 rcond
= fold_binary (code
, type
, real0
, real1
);
12177 if (rcond
&& TREE_CODE (rcond
) == INTEGER_CST
)
12179 if (integer_zerop (rcond
))
12181 if (code
== EQ_EXPR
)
12182 return omit_two_operands (type
, boolean_false_node
,
12184 return fold_build2 (NE_EXPR
, type
, imag0
, imag1
);
12188 if (code
== NE_EXPR
)
12189 return omit_two_operands (type
, boolean_true_node
,
12191 return fold_build2 (EQ_EXPR
, type
, imag0
, imag1
);
12195 icond
= fold_binary (code
, type
, imag0
, imag1
);
12196 if (icond
&& TREE_CODE (icond
) == INTEGER_CST
)
12198 if (integer_zerop (icond
))
12200 if (code
== EQ_EXPR
)
12201 return omit_two_operands (type
, boolean_false_node
,
12203 return fold_build2 (NE_EXPR
, type
, real0
, real1
);
12207 if (code
== NE_EXPR
)
12208 return omit_two_operands (type
, boolean_true_node
,
12210 return fold_build2 (EQ_EXPR
, type
, real0
, real1
);
12221 tem
= fold_comparison (code
, type
, op0
, op1
);
12222 if (tem
!= NULL_TREE
)
12225 /* Transform comparisons of the form X +- C CMP X. */
12226 if ((TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
12227 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0)
12228 && ((TREE_CODE (TREE_OPERAND (arg0
, 1)) == REAL_CST
12229 && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
))))
12230 || (TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
12231 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1
)))))
12233 tree arg01
= TREE_OPERAND (arg0
, 1);
12234 enum tree_code code0
= TREE_CODE (arg0
);
12237 if (TREE_CODE (arg01
) == REAL_CST
)
12238 is_positive
= REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01
)) ? -1 : 1;
12240 is_positive
= tree_int_cst_sgn (arg01
);
12242 /* (X - c) > X becomes false. */
12243 if (code
== GT_EXPR
12244 && ((code0
== MINUS_EXPR
&& is_positive
>= 0)
12245 || (code0
== PLUS_EXPR
&& is_positive
<= 0)))
12247 if (TREE_CODE (arg01
) == INTEGER_CST
12248 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1
)))
12249 fold_overflow_warning (("assuming signed overflow does not "
12250 "occur when assuming that (X - c) > X "
12251 "is always false"),
12252 WARN_STRICT_OVERFLOW_ALL
);
12253 return constant_boolean_node (0, type
);
12256 /* Likewise (X + c) < X becomes false. */
12257 if (code
== LT_EXPR
12258 && ((code0
== PLUS_EXPR
&& is_positive
>= 0)
12259 || (code0
== MINUS_EXPR
&& is_positive
<= 0)))
12261 if (TREE_CODE (arg01
) == INTEGER_CST
12262 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1
)))
12263 fold_overflow_warning (("assuming signed overflow does not "
12264 "occur when assuming that "
12265 "(X + c) < X is always false"),
12266 WARN_STRICT_OVERFLOW_ALL
);
12267 return constant_boolean_node (0, type
);
12270 /* Convert (X - c) <= X to true. */
12271 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
)))
12273 && ((code0
== MINUS_EXPR
&& is_positive
>= 0)
12274 || (code0
== PLUS_EXPR
&& is_positive
<= 0)))
12276 if (TREE_CODE (arg01
) == INTEGER_CST
12277 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1
)))
12278 fold_overflow_warning (("assuming signed overflow does not "
12279 "occur when assuming that "
12280 "(X - c) <= X is always true"),
12281 WARN_STRICT_OVERFLOW_ALL
);
12282 return constant_boolean_node (1, type
);
12285 /* Convert (X + c) >= X to true. */
12286 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
)))
12288 && ((code0
== PLUS_EXPR
&& is_positive
>= 0)
12289 || (code0
== MINUS_EXPR
&& is_positive
<= 0)))
12291 if (TREE_CODE (arg01
) == INTEGER_CST
12292 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1
)))
12293 fold_overflow_warning (("assuming signed overflow does not "
12294 "occur when assuming that "
12295 "(X + c) >= X is always true"),
12296 WARN_STRICT_OVERFLOW_ALL
);
12297 return constant_boolean_node (1, type
);
12300 if (TREE_CODE (arg01
) == INTEGER_CST
)
12302 /* Convert X + c > X and X - c < X to true for integers. */
12303 if (code
== GT_EXPR
12304 && ((code0
== PLUS_EXPR
&& is_positive
> 0)
12305 || (code0
== MINUS_EXPR
&& is_positive
< 0)))
12307 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1
)))
12308 fold_overflow_warning (("assuming signed overflow does "
12309 "not occur when assuming that "
12310 "(X + c) > X is always true"),
12311 WARN_STRICT_OVERFLOW_ALL
);
12312 return constant_boolean_node (1, type
);
12315 if (code
== LT_EXPR
12316 && ((code0
== MINUS_EXPR
&& is_positive
> 0)
12317 || (code0
== PLUS_EXPR
&& is_positive
< 0)))
12319 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1
)))
12320 fold_overflow_warning (("assuming signed overflow does "
12321 "not occur when assuming that "
12322 "(X - c) < X is always true"),
12323 WARN_STRICT_OVERFLOW_ALL
);
12324 return constant_boolean_node (1, type
);
12327 /* Convert X + c <= X and X - c >= X to false for integers. */
12328 if (code
== LE_EXPR
12329 && ((code0
== PLUS_EXPR
&& is_positive
> 0)
12330 || (code0
== MINUS_EXPR
&& is_positive
< 0)))
12332 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1
)))
12333 fold_overflow_warning (("assuming signed overflow does "
12334 "not occur when assuming that "
12335 "(X + c) <= X is always false"),
12336 WARN_STRICT_OVERFLOW_ALL
);
12337 return constant_boolean_node (0, type
);
12340 if (code
== GE_EXPR
12341 && ((code0
== MINUS_EXPR
&& is_positive
> 0)
12342 || (code0
== PLUS_EXPR
&& is_positive
< 0)))
12344 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1
)))
12345 fold_overflow_warning (("assuming signed overflow does "
12346 "not occur when assuming that "
12347 "(X - c) >= X is always false"),
12348 WARN_STRICT_OVERFLOW_ALL
);
12349 return constant_boolean_node (0, type
);
12354 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
12355 This transformation affects the cases which are handled in later
12356 optimizations involving comparisons with non-negative constants. */
12357 if (TREE_CODE (arg1
) == INTEGER_CST
12358 && TREE_CODE (arg0
) != INTEGER_CST
12359 && tree_int_cst_sgn (arg1
) > 0)
12361 if (code
== GE_EXPR
)
12363 arg1
= const_binop (MINUS_EXPR
, arg1
,
12364 build_int_cst (TREE_TYPE (arg1
), 1), 0);
12365 return fold_build2 (GT_EXPR
, type
, arg0
,
12366 fold_convert (TREE_TYPE (arg0
), arg1
));
12368 if (code
== LT_EXPR
)
12370 arg1
= const_binop (MINUS_EXPR
, arg1
,
12371 build_int_cst (TREE_TYPE (arg1
), 1), 0);
12372 return fold_build2 (LE_EXPR
, type
, arg0
,
12373 fold_convert (TREE_TYPE (arg0
), arg1
));
12377 /* Comparisons with the highest or lowest possible integer of
12378 the specified precision will have known values. */
12380 tree arg1_type
= TREE_TYPE (arg1
);
12381 unsigned int width
= TYPE_PRECISION (arg1_type
);
12383 if (TREE_CODE (arg1
) == INTEGER_CST
12384 && !TREE_OVERFLOW (arg1
)
12385 && width
<= 2 * HOST_BITS_PER_WIDE_INT
12386 && (INTEGRAL_TYPE_P (arg1_type
) || POINTER_TYPE_P (arg1_type
)))
12388 HOST_WIDE_INT signed_max_hi
;
12389 unsigned HOST_WIDE_INT signed_max_lo
;
12390 unsigned HOST_WIDE_INT max_hi
, max_lo
, min_hi
, min_lo
;
12392 if (width
<= HOST_BITS_PER_WIDE_INT
)
12394 signed_max_lo
= ((unsigned HOST_WIDE_INT
) 1 << (width
- 1))
12399 if (TYPE_UNSIGNED (arg1_type
))
12401 max_lo
= ((unsigned HOST_WIDE_INT
) 2 << (width
- 1)) - 1;
12407 max_lo
= signed_max_lo
;
12408 min_lo
= ((unsigned HOST_WIDE_INT
) -1 << (width
- 1));
12414 width
-= HOST_BITS_PER_WIDE_INT
;
12415 signed_max_lo
= -1;
12416 signed_max_hi
= ((unsigned HOST_WIDE_INT
) 1 << (width
- 1))
12421 if (TYPE_UNSIGNED (arg1_type
))
12423 max_hi
= ((unsigned HOST_WIDE_INT
) 2 << (width
- 1)) - 1;
12428 max_hi
= signed_max_hi
;
12429 min_hi
= ((unsigned HOST_WIDE_INT
) -1 << (width
- 1));
12433 if ((unsigned HOST_WIDE_INT
) TREE_INT_CST_HIGH (arg1
) == max_hi
12434 && TREE_INT_CST_LOW (arg1
) == max_lo
)
12438 return omit_one_operand (type
, integer_zero_node
, arg0
);
12441 return fold_build2 (EQ_EXPR
, type
, op0
, op1
);
12444 return omit_one_operand (type
, integer_one_node
, arg0
);
12447 return fold_build2 (NE_EXPR
, type
, op0
, op1
);
12449 /* The GE_EXPR and LT_EXPR cases above are not normally
12450 reached because of previous transformations. */
12455 else if ((unsigned HOST_WIDE_INT
) TREE_INT_CST_HIGH (arg1
)
12457 && TREE_INT_CST_LOW (arg1
) == max_lo
- 1)
12461 arg1
= const_binop (PLUS_EXPR
, arg1
,
12462 build_int_cst (TREE_TYPE (arg1
), 1), 0);
12463 return fold_build2 (EQ_EXPR
, type
,
12464 fold_convert (TREE_TYPE (arg1
), arg0
),
12467 arg1
= const_binop (PLUS_EXPR
, arg1
,
12468 build_int_cst (TREE_TYPE (arg1
), 1), 0);
12469 return fold_build2 (NE_EXPR
, type
,
12470 fold_convert (TREE_TYPE (arg1
), arg0
),
12475 else if ((unsigned HOST_WIDE_INT
) TREE_INT_CST_HIGH (arg1
)
12477 && TREE_INT_CST_LOW (arg1
) == min_lo
)
12481 return omit_one_operand (type
, integer_zero_node
, arg0
);
12484 return fold_build2 (EQ_EXPR
, type
, op0
, op1
);
12487 return omit_one_operand (type
, integer_one_node
, arg0
);
12490 return fold_build2 (NE_EXPR
, type
, op0
, op1
);
12495 else if ((unsigned HOST_WIDE_INT
) TREE_INT_CST_HIGH (arg1
)
12497 && TREE_INT_CST_LOW (arg1
) == min_lo
+ 1)
12501 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
12502 return fold_build2 (NE_EXPR
, type
,
12503 fold_convert (TREE_TYPE (arg1
), arg0
),
12506 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
12507 return fold_build2 (EQ_EXPR
, type
,
12508 fold_convert (TREE_TYPE (arg1
), arg0
),
12514 else if (TREE_INT_CST_HIGH (arg1
) == signed_max_hi
12515 && TREE_INT_CST_LOW (arg1
) == signed_max_lo
12516 && TYPE_UNSIGNED (arg1_type
)
12517 /* We will flip the signedness of the comparison operator
12518 associated with the mode of arg1, so the sign bit is
12519 specified by this mode. Check that arg1 is the signed
12520 max associated with this sign bit. */
12521 && width
== GET_MODE_BITSIZE (TYPE_MODE (arg1_type
))
12522 /* signed_type does not work on pointer types. */
12523 && INTEGRAL_TYPE_P (arg1_type
))
12525 /* The following case also applies to X < signed_max+1
12526 and X >= signed_max+1 because previous transformations. */
12527 if (code
== LE_EXPR
|| code
== GT_EXPR
)
12530 st
= signed_type_for (TREE_TYPE (arg1
));
12531 return fold_build2 (code
== LE_EXPR
? GE_EXPR
: LT_EXPR
,
12532 type
, fold_convert (st
, arg0
),
12533 build_int_cst (st
, 0));
12539 /* If we are comparing an ABS_EXPR with a constant, we can
12540 convert all the cases into explicit comparisons, but they may
12541 well not be faster than doing the ABS and one comparison.
12542 But ABS (X) <= C is a range comparison, which becomes a subtraction
12543 and a comparison, and is probably faster. */
12544 if (code
== LE_EXPR
12545 && TREE_CODE (arg1
) == INTEGER_CST
12546 && TREE_CODE (arg0
) == ABS_EXPR
12547 && ! TREE_SIDE_EFFECTS (arg0
)
12548 && (0 != (tem
= negate_expr (arg1
)))
12549 && TREE_CODE (tem
) == INTEGER_CST
12550 && !TREE_OVERFLOW (tem
))
12551 return fold_build2 (TRUTH_ANDIF_EXPR
, type
,
12552 build2 (GE_EXPR
, type
,
12553 TREE_OPERAND (arg0
, 0), tem
),
12554 build2 (LE_EXPR
, type
,
12555 TREE_OPERAND (arg0
, 0), arg1
));
12557 /* Convert ABS_EXPR<x> >= 0 to true. */
12558 strict_overflow_p
= false;
12559 if (code
== GE_EXPR
12560 && (integer_zerop (arg1
)
12561 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
)))
12562 && real_zerop (arg1
)))
12563 && tree_expr_nonnegative_warnv_p (arg0
, &strict_overflow_p
))
12565 if (strict_overflow_p
)
12566 fold_overflow_warning (("assuming signed overflow does not occur "
12567 "when simplifying comparison of "
12568 "absolute value and zero"),
12569 WARN_STRICT_OVERFLOW_CONDITIONAL
);
12570 return omit_one_operand (type
, integer_one_node
, arg0
);
12573 /* Convert ABS_EXPR<x> < 0 to false. */
12574 strict_overflow_p
= false;
12575 if (code
== LT_EXPR
12576 && (integer_zerop (arg1
) || real_zerop (arg1
))
12577 && tree_expr_nonnegative_warnv_p (arg0
, &strict_overflow_p
))
12579 if (strict_overflow_p
)
12580 fold_overflow_warning (("assuming signed overflow does not occur "
12581 "when simplifying comparison of "
12582 "absolute value and zero"),
12583 WARN_STRICT_OVERFLOW_CONDITIONAL
);
12584 return omit_one_operand (type
, integer_zero_node
, arg0
);
12587 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
12588 and similarly for >= into !=. */
12589 if ((code
== LT_EXPR
|| code
== GE_EXPR
)
12590 && TYPE_UNSIGNED (TREE_TYPE (arg0
))
12591 && TREE_CODE (arg1
) == LSHIFT_EXPR
12592 && integer_onep (TREE_OPERAND (arg1
, 0)))
12593 return build2 (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
12594 build2 (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
12595 TREE_OPERAND (arg1
, 1)),
12596 build_int_cst (TREE_TYPE (arg0
), 0));
12598 if ((code
== LT_EXPR
|| code
== GE_EXPR
)
12599 && TYPE_UNSIGNED (TREE_TYPE (arg0
))
12600 && (TREE_CODE (arg1
) == NOP_EXPR
12601 || TREE_CODE (arg1
) == CONVERT_EXPR
)
12602 && TREE_CODE (TREE_OPERAND (arg1
, 0)) == LSHIFT_EXPR
12603 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0)))
12605 build2 (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
12606 fold_convert (TREE_TYPE (arg0
),
12607 build2 (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
12608 TREE_OPERAND (TREE_OPERAND (arg1
, 0),
12610 build_int_cst (TREE_TYPE (arg0
), 0));
12614 case UNORDERED_EXPR
:
12622 if (TREE_CODE (arg0
) == REAL_CST
&& TREE_CODE (arg1
) == REAL_CST
)
12624 t1
= fold_relational_const (code
, type
, arg0
, arg1
);
12625 if (t1
!= NULL_TREE
)
12629 /* If the first operand is NaN, the result is constant. */
12630 if (TREE_CODE (arg0
) == REAL_CST
12631 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0
))
12632 && (code
!= LTGT_EXPR
|| ! flag_trapping_math
))
12634 t1
= (code
== ORDERED_EXPR
|| code
== LTGT_EXPR
)
12635 ? integer_zero_node
12636 : integer_one_node
;
12637 return omit_one_operand (type
, t1
, arg1
);
12640 /* If the second operand is NaN, the result is constant. */
12641 if (TREE_CODE (arg1
) == REAL_CST
12642 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
))
12643 && (code
!= LTGT_EXPR
|| ! flag_trapping_math
))
12645 t1
= (code
== ORDERED_EXPR
|| code
== LTGT_EXPR
)
12646 ? integer_zero_node
12647 : integer_one_node
;
12648 return omit_one_operand (type
, t1
, arg0
);
12651 /* Simplify unordered comparison of something with itself. */
12652 if ((code
== UNLE_EXPR
|| code
== UNGE_EXPR
|| code
== UNEQ_EXPR
)
12653 && operand_equal_p (arg0
, arg1
, 0))
12654 return constant_boolean_node (1, type
);
12656 if (code
== LTGT_EXPR
12657 && !flag_trapping_math
12658 && operand_equal_p (arg0
, arg1
, 0))
12659 return constant_boolean_node (0, type
);
12661 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
12663 tree targ0
= strip_float_extensions (arg0
);
12664 tree targ1
= strip_float_extensions (arg1
);
12665 tree newtype
= TREE_TYPE (targ0
);
12667 if (TYPE_PRECISION (TREE_TYPE (targ1
)) > TYPE_PRECISION (newtype
))
12668 newtype
= TREE_TYPE (targ1
);
12670 if (TYPE_PRECISION (newtype
) < TYPE_PRECISION (TREE_TYPE (arg0
)))
12671 return fold_build2 (code
, type
, fold_convert (newtype
, targ0
),
12672 fold_convert (newtype
, targ1
));
12677 case COMPOUND_EXPR
:
12678 /* When pedantic, a compound expression can be neither an lvalue
12679 nor an integer constant expression. */
12680 if (TREE_SIDE_EFFECTS (arg0
) || TREE_CONSTANT (arg1
))
12682 /* Don't let (0, 0) be null pointer constant. */
12683 tem
= integer_zerop (arg1
) ? build1 (NOP_EXPR
, type
, arg1
)
12684 : fold_convert (type
, arg1
);
12685 return pedantic_non_lvalue (tem
);
12688 if ((TREE_CODE (arg0
) == REAL_CST
12689 && TREE_CODE (arg1
) == REAL_CST
)
12690 || (TREE_CODE (arg0
) == INTEGER_CST
12691 && TREE_CODE (arg1
) == INTEGER_CST
))
12692 return build_complex (type
, arg0
, arg1
);
12696 /* An ASSERT_EXPR should never be passed to fold_binary. */
12697 gcc_unreachable ();
12701 } /* switch (code) */
12704 /* Callback for walk_tree, looking for LABEL_EXPR.
12705 Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
12706 Do not check the sub-tree of GOTO_EXPR. */
12709 contains_label_1 (tree
*tp
,
12710 int *walk_subtrees
,
12711 void *data ATTRIBUTE_UNUSED
)
12713 switch (TREE_CODE (*tp
))
12718 *walk_subtrees
= 0;
12725 /* Checks whether the sub-tree ST contains a label LABEL_EXPR which is
12726 accessible from outside the sub-tree. Returns NULL_TREE if no
12727 addressable label is found. */
12730 contains_label_p (tree st
)
12732 return (walk_tree (&st
, contains_label_1
, NULL
, NULL
) != NULL_TREE
);
12735 /* Fold a ternary expression of code CODE and type TYPE with operands
12736 OP0, OP1, and OP2. Return the folded expression if folding is
12737 successful. Otherwise, return NULL_TREE. */
12740 fold_ternary (enum tree_code code
, tree type
, tree op0
, tree op1
, tree op2
)
12743 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
;
12744 enum tree_code_class kind
= TREE_CODE_CLASS (code
);
12746 gcc_assert (IS_EXPR_CODE_CLASS (kind
)
12747 && TREE_CODE_LENGTH (code
) == 3);
12749 /* Strip any conversions that don't change the mode. This is safe
12750 for every expression, except for a comparison expression because
12751 its signedness is derived from its operands. So, in the latter
12752 case, only strip conversions that don't change the signedness.
12754 Note that this is done as an internal manipulation within the
12755 constant folder, in order to find the simplest representation of
12756 the arguments so that their form can be studied. In any cases,
12757 the appropriate type conversions should be put back in the tree
12758 that will get out of the constant folder. */
12773 case COMPONENT_REF
:
12774 if (TREE_CODE (arg0
) == CONSTRUCTOR
12775 && ! type_contains_placeholder_p (TREE_TYPE (arg0
)))
12777 unsigned HOST_WIDE_INT idx
;
12779 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0
), idx
, field
, value
)
12786 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
12787 so all simple results must be passed through pedantic_non_lvalue. */
12788 if (TREE_CODE (arg0
) == INTEGER_CST
)
12790 tree unused_op
= integer_zerop (arg0
) ? op1
: op2
;
12791 tem
= integer_zerop (arg0
) ? op2
: op1
;
12792 /* Only optimize constant conditions when the selected branch
12793 has the same type as the COND_EXPR. This avoids optimizing
12794 away "c ? x : throw", where the throw has a void type.
12795 Avoid throwing away that operand which contains label. */
12796 if ((!TREE_SIDE_EFFECTS (unused_op
)
12797 || !contains_label_p (unused_op
))
12798 && (! VOID_TYPE_P (TREE_TYPE (tem
))
12799 || VOID_TYPE_P (type
)))
12800 return pedantic_non_lvalue (tem
);
12803 if (operand_equal_p (arg1
, op2
, 0))
12804 return pedantic_omit_one_operand (type
, arg1
, arg0
);
12806 /* If we have A op B ? A : C, we may be able to convert this to a
12807 simpler expression, depending on the operation and the values
12808 of B and C. Signed zeros prevent all of these transformations,
12809 for reasons given above each one.
12811 Also try swapping the arguments and inverting the conditional. */
12812 if (COMPARISON_CLASS_P (arg0
)
12813 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
12814 arg1
, TREE_OPERAND (arg0
, 1))
12815 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1
))))
12817 tem
= fold_cond_expr_with_comparison (type
, arg0
, op1
, op2
);
12822 if (COMPARISON_CLASS_P (arg0
)
12823 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
12825 TREE_OPERAND (arg0
, 1))
12826 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2
))))
12828 tem
= fold_truth_not_expr (arg0
);
12829 if (tem
&& COMPARISON_CLASS_P (tem
))
12831 tem
= fold_cond_expr_with_comparison (type
, tem
, op2
, op1
);
12837 /* If the second operand is simpler than the third, swap them
12838 since that produces better jump optimization results. */
12839 if (truth_value_p (TREE_CODE (arg0
))
12840 && tree_swap_operands_p (op1
, op2
, false))
12842 /* See if this can be inverted. If it can't, possibly because
12843 it was a floating-point inequality comparison, don't do
12845 tem
= fold_truth_not_expr (arg0
);
12847 return fold_build3 (code
, type
, tem
, op2
, op1
);
12850 /* Convert A ? 1 : 0 to simply A. */
12851 if (integer_onep (op1
)
12852 && integer_zerop (op2
)
12853 /* If we try to convert OP0 to our type, the
12854 call to fold will try to move the conversion inside
12855 a COND, which will recurse. In that case, the COND_EXPR
12856 is probably the best choice, so leave it alone. */
12857 && type
== TREE_TYPE (arg0
))
12858 return pedantic_non_lvalue (arg0
);
12860 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
12861 over COND_EXPR in cases such as floating point comparisons. */
12862 if (integer_zerop (op1
)
12863 && integer_onep (op2
)
12864 && truth_value_p (TREE_CODE (arg0
)))
12865 return pedantic_non_lvalue (fold_convert (type
,
12866 invert_truthvalue (arg0
)));
12868 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
12869 if (TREE_CODE (arg0
) == LT_EXPR
12870 && integer_zerop (TREE_OPERAND (arg0
, 1))
12871 && integer_zerop (op2
)
12872 && (tem
= sign_bit_p (TREE_OPERAND (arg0
, 0), arg1
)))
12874 /* sign_bit_p only checks ARG1 bits within A's precision.
12875 If <sign bit of A> has wider type than A, bits outside
12876 of A's precision in <sign bit of A> need to be checked.
12877 If they are all 0, this optimization needs to be done
12878 in unsigned A's type, if they are all 1 in signed A's type,
12879 otherwise this can't be done. */
12880 if (TYPE_PRECISION (TREE_TYPE (tem
))
12881 < TYPE_PRECISION (TREE_TYPE (arg1
))
12882 && TYPE_PRECISION (TREE_TYPE (tem
))
12883 < TYPE_PRECISION (type
))
12885 unsigned HOST_WIDE_INT mask_lo
;
12886 HOST_WIDE_INT mask_hi
;
12887 int inner_width
, outer_width
;
12890 inner_width
= TYPE_PRECISION (TREE_TYPE (tem
));
12891 outer_width
= TYPE_PRECISION (TREE_TYPE (arg1
));
12892 if (outer_width
> TYPE_PRECISION (type
))
12893 outer_width
= TYPE_PRECISION (type
);
12895 if (outer_width
> HOST_BITS_PER_WIDE_INT
)
12897 mask_hi
= ((unsigned HOST_WIDE_INT
) -1
12898 >> (2 * HOST_BITS_PER_WIDE_INT
- outer_width
));
12904 mask_lo
= ((unsigned HOST_WIDE_INT
) -1
12905 >> (HOST_BITS_PER_WIDE_INT
- outer_width
));
12907 if (inner_width
> HOST_BITS_PER_WIDE_INT
)
12909 mask_hi
&= ~((unsigned HOST_WIDE_INT
) -1
12910 >> (HOST_BITS_PER_WIDE_INT
- inner_width
));
12914 mask_lo
&= ~((unsigned HOST_WIDE_INT
) -1
12915 >> (HOST_BITS_PER_WIDE_INT
- inner_width
));
12917 if ((TREE_INT_CST_HIGH (arg1
) & mask_hi
) == mask_hi
12918 && (TREE_INT_CST_LOW (arg1
) & mask_lo
) == mask_lo
)
12920 tem_type
= signed_type_for (TREE_TYPE (tem
));
12921 tem
= fold_convert (tem_type
, tem
);
12923 else if ((TREE_INT_CST_HIGH (arg1
) & mask_hi
) == 0
12924 && (TREE_INT_CST_LOW (arg1
) & mask_lo
) == 0)
12926 tem_type
= unsigned_type_for (TREE_TYPE (tem
));
12927 tem
= fold_convert (tem_type
, tem
);
12934 return fold_convert (type
,
12935 fold_build2 (BIT_AND_EXPR
,
12936 TREE_TYPE (tem
), tem
,
12937 fold_convert (TREE_TYPE (tem
),
12941 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
12942 already handled above. */
12943 if (TREE_CODE (arg0
) == BIT_AND_EXPR
12944 && integer_onep (TREE_OPERAND (arg0
, 1))
12945 && integer_zerop (op2
)
12946 && integer_pow2p (arg1
))
12948 tree tem
= TREE_OPERAND (arg0
, 0);
12950 if (TREE_CODE (tem
) == RSHIFT_EXPR
12951 && TREE_CODE (TREE_OPERAND (tem
, 1)) == INTEGER_CST
12952 && (unsigned HOST_WIDE_INT
) tree_log2 (arg1
) ==
12953 TREE_INT_CST_LOW (TREE_OPERAND (tem
, 1)))
12954 return fold_build2 (BIT_AND_EXPR
, type
,
12955 TREE_OPERAND (tem
, 0), arg1
);
12958 /* A & N ? N : 0 is simply A & N if N is a power of two. This
12959 is probably obsolete because the first operand should be a
12960 truth value (that's why we have the two cases above), but let's
12961 leave it in until we can confirm this for all front-ends. */
12962 if (integer_zerop (op2
)
12963 && TREE_CODE (arg0
) == NE_EXPR
12964 && integer_zerop (TREE_OPERAND (arg0
, 1))
12965 && integer_pow2p (arg1
)
12966 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == BIT_AND_EXPR
12967 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1),
12968 arg1
, OEP_ONLY_CONST
))
12969 return pedantic_non_lvalue (fold_convert (type
,
12970 TREE_OPERAND (arg0
, 0)));
12972 /* Convert A ? B : 0 into A && B if A and B are truth values. */
12973 if (integer_zerop (op2
)
12974 && truth_value_p (TREE_CODE (arg0
))
12975 && truth_value_p (TREE_CODE (arg1
)))
12976 return fold_build2 (TRUTH_ANDIF_EXPR
, type
,
12977 fold_convert (type
, arg0
),
12980 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
12981 if (integer_onep (op2
)
12982 && truth_value_p (TREE_CODE (arg0
))
12983 && truth_value_p (TREE_CODE (arg1
)))
12985 /* Only perform transformation if ARG0 is easily inverted. */
12986 tem
= fold_truth_not_expr (arg0
);
12988 return fold_build2 (TRUTH_ORIF_EXPR
, type
,
12989 fold_convert (type
, tem
),
12993 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
12994 if (integer_zerop (arg1
)
12995 && truth_value_p (TREE_CODE (arg0
))
12996 && truth_value_p (TREE_CODE (op2
)))
12998 /* Only perform transformation if ARG0 is easily inverted. */
12999 tem
= fold_truth_not_expr (arg0
);
13001 return fold_build2 (TRUTH_ANDIF_EXPR
, type
,
13002 fold_convert (type
, tem
),
13006 /* Convert A ? 1 : B into A || B if A and B are truth values. */
13007 if (integer_onep (arg1
)
13008 && truth_value_p (TREE_CODE (arg0
))
13009 && truth_value_p (TREE_CODE (op2
)))
13010 return fold_build2 (TRUTH_ORIF_EXPR
, type
,
13011 fold_convert (type
, arg0
),
13017 /* CALL_EXPRs used to be ternary exprs. Catch any mistaken uses
13018 of fold_ternary on them. */
13019 gcc_unreachable ();
13021 case BIT_FIELD_REF
:
13022 if ((TREE_CODE (arg0
) == VECTOR_CST
13023 || (TREE_CODE (arg0
) == CONSTRUCTOR
&& TREE_CONSTANT (arg0
)))
13024 && type
== TREE_TYPE (TREE_TYPE (arg0
))
13025 && host_integerp (arg1
, 1)
13026 && host_integerp (op2
, 1))
13028 unsigned HOST_WIDE_INT width
= tree_low_cst (arg1
, 1);
13029 unsigned HOST_WIDE_INT idx
= tree_low_cst (op2
, 1);
13032 && simple_cst_equal (arg1
, TYPE_SIZE (type
)) == 1
13033 && (idx
% width
) == 0
13034 && (idx
= idx
/ width
)
13035 < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0
)))
13037 tree elements
= NULL_TREE
;
13039 if (TREE_CODE (arg0
) == VECTOR_CST
)
13040 elements
= TREE_VECTOR_CST_ELTS (arg0
);
13043 unsigned HOST_WIDE_INT idx
;
13046 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg0
), idx
, value
)
13047 elements
= tree_cons (NULL_TREE
, value
, elements
);
13049 while (idx
-- > 0 && elements
)
13050 elements
= TREE_CHAIN (elements
);
13052 return TREE_VALUE (elements
);
13054 return fold_convert (type
, integer_zero_node
);
13061 } /* switch (code) */
13064 /* Perform constant folding and related simplification of EXPR.
13065 The related simplifications include x*1 => x, x*0 => 0, etc.,
13066 and application of the associative law.
13067 NOP_EXPR conversions may be removed freely (as long as we
13068 are careful not to change the type of the overall expression).
13069 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
13070 but we can constant-fold them if they have constant operands. */
13072 #ifdef ENABLE_FOLD_CHECKING
13073 # define fold(x) fold_1 (x)
13074 static tree
fold_1 (tree
);
13080 const tree t
= expr
;
13081 enum tree_code code
= TREE_CODE (t
);
13082 enum tree_code_class kind
= TREE_CODE_CLASS (code
);
13085 /* Return right away if a constant. */
13086 if (kind
== tcc_constant
)
13089 /* CALL_EXPR-like objects with variable numbers of operands are
13090 treated specially. */
13091 if (kind
== tcc_vl_exp
)
13093 if (code
== CALL_EXPR
)
13095 tem
= fold_call_expr (expr
, false);
13096 return tem
? tem
: expr
;
13101 if (IS_EXPR_CODE_CLASS (kind
)
13102 || IS_GIMPLE_STMT_CODE_CLASS (kind
))
13104 tree type
= TREE_TYPE (t
);
13105 tree op0
, op1
, op2
;
13107 switch (TREE_CODE_LENGTH (code
))
13110 op0
= TREE_OPERAND (t
, 0);
13111 tem
= fold_unary (code
, type
, op0
);
13112 return tem
? tem
: expr
;
13114 op0
= TREE_OPERAND (t
, 0);
13115 op1
= TREE_OPERAND (t
, 1);
13116 tem
= fold_binary (code
, type
, op0
, op1
);
13117 return tem
? tem
: expr
;
13119 op0
= TREE_OPERAND (t
, 0);
13120 op1
= TREE_OPERAND (t
, 1);
13121 op2
= TREE_OPERAND (t
, 2);
13122 tem
= fold_ternary (code
, type
, op0
, op1
, op2
);
13123 return tem
? tem
: expr
;
13132 return fold (DECL_INITIAL (t
));
13136 } /* switch (code) */
13139 #ifdef ENABLE_FOLD_CHECKING
13142 static void fold_checksum_tree (tree
, struct md5_ctx
*, htab_t
);
13143 static void fold_check_failed (tree
, tree
);
13144 void print_fold_checksum (tree
);
13146 /* When --enable-checking=fold, compute a digest of expr before
13147 and after actual fold call to see if fold did not accidentally
13148 change original expr. */
13154 struct md5_ctx ctx
;
13155 unsigned char checksum_before
[16], checksum_after
[16];
13158 ht
= htab_create (32, htab_hash_pointer
, htab_eq_pointer
, NULL
);
13159 md5_init_ctx (&ctx
);
13160 fold_checksum_tree (expr
, &ctx
, ht
);
13161 md5_finish_ctx (&ctx
, checksum_before
);
13164 ret
= fold_1 (expr
);
13166 md5_init_ctx (&ctx
);
13167 fold_checksum_tree (expr
, &ctx
, ht
);
13168 md5_finish_ctx (&ctx
, checksum_after
);
13171 if (memcmp (checksum_before
, checksum_after
, 16))
13172 fold_check_failed (expr
, ret
);
13178 print_fold_checksum (tree expr
)
13180 struct md5_ctx ctx
;
13181 unsigned char checksum
[16], cnt
;
13184 ht
= htab_create (32, htab_hash_pointer
, htab_eq_pointer
, NULL
);
13185 md5_init_ctx (&ctx
);
13186 fold_checksum_tree (expr
, &ctx
, ht
);
13187 md5_finish_ctx (&ctx
, checksum
);
13189 for (cnt
= 0; cnt
< 16; ++cnt
)
13190 fprintf (stderr
, "%02x", checksum
[cnt
]);
13191 putc ('\n', stderr
);
13195 fold_check_failed (tree expr ATTRIBUTE_UNUSED
, tree ret ATTRIBUTE_UNUSED
)
13197 internal_error ("fold check: original tree changed by fold");
13201 fold_checksum_tree (tree expr
, struct md5_ctx
*ctx
, htab_t ht
)
13204 enum tree_code code
;
13205 struct tree_function_decl buf
;
13210 gcc_assert ((sizeof (struct tree_exp
) + 5 * sizeof (tree
)
13211 <= sizeof (struct tree_function_decl
))
13212 && sizeof (struct tree_type
) <= sizeof (struct tree_function_decl
));
13215 slot
= htab_find_slot (ht
, expr
, INSERT
);
13219 code
= TREE_CODE (expr
);
13220 if (TREE_CODE_CLASS (code
) == tcc_declaration
13221 && DECL_ASSEMBLER_NAME_SET_P (expr
))
13223 /* Allow DECL_ASSEMBLER_NAME to be modified. */
13224 memcpy ((char *) &buf
, expr
, tree_size (expr
));
13225 expr
= (tree
) &buf
;
13226 SET_DECL_ASSEMBLER_NAME (expr
, NULL
);
13228 else if (TREE_CODE_CLASS (code
) == tcc_type
13229 && (TYPE_POINTER_TO (expr
) || TYPE_REFERENCE_TO (expr
)
13230 || TYPE_CACHED_VALUES_P (expr
)
13231 || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr
)))
13233 /* Allow these fields to be modified. */
13234 memcpy ((char *) &buf
, expr
, tree_size (expr
));
13235 expr
= (tree
) &buf
;
13236 TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr
) = 0;
13237 TYPE_POINTER_TO (expr
) = NULL
;
13238 TYPE_REFERENCE_TO (expr
) = NULL
;
13239 if (TYPE_CACHED_VALUES_P (expr
))
13241 TYPE_CACHED_VALUES_P (expr
) = 0;
13242 TYPE_CACHED_VALUES (expr
) = NULL
;
13245 md5_process_bytes (expr
, tree_size (expr
), ctx
);
13246 fold_checksum_tree (TREE_TYPE (expr
), ctx
, ht
);
13247 if (TREE_CODE_CLASS (code
) != tcc_type
13248 && TREE_CODE_CLASS (code
) != tcc_declaration
13249 && code
!= TREE_LIST
13250 && code
!= SSA_NAME
)
13251 fold_checksum_tree (TREE_CHAIN (expr
), ctx
, ht
);
13252 switch (TREE_CODE_CLASS (code
))
13258 md5_process_bytes (TREE_STRING_POINTER (expr
),
13259 TREE_STRING_LENGTH (expr
), ctx
);
13262 fold_checksum_tree (TREE_REALPART (expr
), ctx
, ht
);
13263 fold_checksum_tree (TREE_IMAGPART (expr
), ctx
, ht
);
13266 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr
), ctx
, ht
);
13272 case tcc_exceptional
:
13276 fold_checksum_tree (TREE_PURPOSE (expr
), ctx
, ht
);
13277 fold_checksum_tree (TREE_VALUE (expr
), ctx
, ht
);
13278 expr
= TREE_CHAIN (expr
);
13279 goto recursive_label
;
13282 for (i
= 0; i
< TREE_VEC_LENGTH (expr
); ++i
)
13283 fold_checksum_tree (TREE_VEC_ELT (expr
, i
), ctx
, ht
);
13289 case tcc_expression
:
13290 case tcc_reference
:
13291 case tcc_comparison
:
13294 case tcc_statement
:
13296 len
= TREE_OPERAND_LENGTH (expr
);
13297 for (i
= 0; i
< len
; ++i
)
13298 fold_checksum_tree (TREE_OPERAND (expr
, i
), ctx
, ht
);
13300 case tcc_declaration
:
13301 fold_checksum_tree (DECL_NAME (expr
), ctx
, ht
);
13302 fold_checksum_tree (DECL_CONTEXT (expr
), ctx
, ht
);
13303 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr
), TS_DECL_COMMON
))
13305 fold_checksum_tree (DECL_SIZE (expr
), ctx
, ht
);
13306 fold_checksum_tree (DECL_SIZE_UNIT (expr
), ctx
, ht
);
13307 fold_checksum_tree (DECL_INITIAL (expr
), ctx
, ht
);
13308 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr
), ctx
, ht
);
13309 fold_checksum_tree (DECL_ATTRIBUTES (expr
), ctx
, ht
);
13311 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr
), TS_DECL_WITH_VIS
))
13312 fold_checksum_tree (DECL_SECTION_NAME (expr
), ctx
, ht
);
13314 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr
), TS_DECL_NON_COMMON
))
13316 fold_checksum_tree (DECL_VINDEX (expr
), ctx
, ht
);
13317 fold_checksum_tree (DECL_RESULT_FLD (expr
), ctx
, ht
);
13318 fold_checksum_tree (DECL_ARGUMENT_FLD (expr
), ctx
, ht
);
13322 if (TREE_CODE (expr
) == ENUMERAL_TYPE
)
13323 fold_checksum_tree (TYPE_VALUES (expr
), ctx
, ht
);
13324 fold_checksum_tree (TYPE_SIZE (expr
), ctx
, ht
);
13325 fold_checksum_tree (TYPE_SIZE_UNIT (expr
), ctx
, ht
);
13326 fold_checksum_tree (TYPE_ATTRIBUTES (expr
), ctx
, ht
);
13327 fold_checksum_tree (TYPE_NAME (expr
), ctx
, ht
);
13328 if (INTEGRAL_TYPE_P (expr
)
13329 || SCALAR_FLOAT_TYPE_P (expr
))
13331 fold_checksum_tree (TYPE_MIN_VALUE (expr
), ctx
, ht
);
13332 fold_checksum_tree (TYPE_MAX_VALUE (expr
), ctx
, ht
);
13334 fold_checksum_tree (TYPE_MAIN_VARIANT (expr
), ctx
, ht
);
13335 if (TREE_CODE (expr
) == RECORD_TYPE
13336 || TREE_CODE (expr
) == UNION_TYPE
13337 || TREE_CODE (expr
) == QUAL_UNION_TYPE
)
13338 fold_checksum_tree (TYPE_BINFO (expr
), ctx
, ht
);
13339 fold_checksum_tree (TYPE_CONTEXT (expr
), ctx
, ht
);
13346 /* Helper function for outputting the checksum of a tree T. When
13347 debugging with gdb, you can "define mynext" to be "next" followed
13348 by "call debug_fold_checksum (op0)", then just trace down till the
13352 debug_fold_checksum (tree t
)
13355 unsigned char checksum
[16];
13356 struct md5_ctx ctx
;
13357 htab_t ht
= htab_create (32, htab_hash_pointer
, htab_eq_pointer
, NULL
);
13359 md5_init_ctx (&ctx
);
13360 fold_checksum_tree (t
, &ctx
, ht
);
13361 md5_finish_ctx (&ctx
, checksum
);
13364 for (i
= 0; i
< 16; i
++)
13365 fprintf (stderr
, "%d ", checksum
[i
]);
13367 fprintf (stderr
, "\n");
13372 /* Fold a unary tree expression with code CODE of type TYPE with an
13373 operand OP0. Return a folded expression if successful. Otherwise,
13374 return a tree expression with code CODE of type TYPE with an
13378 fold_build1_stat (enum tree_code code
, tree type
, tree op0 MEM_STAT_DECL
)
13381 #ifdef ENABLE_FOLD_CHECKING
13382 unsigned char checksum_before
[16], checksum_after
[16];
13383 struct md5_ctx ctx
;
13386 ht
= htab_create (32, htab_hash_pointer
, htab_eq_pointer
, NULL
);
13387 md5_init_ctx (&ctx
);
13388 fold_checksum_tree (op0
, &ctx
, ht
);
13389 md5_finish_ctx (&ctx
, checksum_before
);
13393 tem
= fold_unary (code
, type
, op0
);
13395 tem
= build1_stat (code
, type
, op0 PASS_MEM_STAT
);
13397 #ifdef ENABLE_FOLD_CHECKING
13398 md5_init_ctx (&ctx
);
13399 fold_checksum_tree (op0
, &ctx
, ht
);
13400 md5_finish_ctx (&ctx
, checksum_after
);
13403 if (memcmp (checksum_before
, checksum_after
, 16))
13404 fold_check_failed (op0
, tem
);
13409 /* Fold a binary tree expression with code CODE of type TYPE with
13410 operands OP0 and OP1. Return a folded expression if successful.
13411 Otherwise, return a tree expression with code CODE of type TYPE
13412 with operands OP0 and OP1. */
13415 fold_build2_stat (enum tree_code code
, tree type
, tree op0
, tree op1
13419 #ifdef ENABLE_FOLD_CHECKING
13420 unsigned char checksum_before_op0
[16],
13421 checksum_before_op1
[16],
13422 checksum_after_op0
[16],
13423 checksum_after_op1
[16];
13424 struct md5_ctx ctx
;
13427 ht
= htab_create (32, htab_hash_pointer
, htab_eq_pointer
, NULL
);
13428 md5_init_ctx (&ctx
);
13429 fold_checksum_tree (op0
, &ctx
, ht
);
13430 md5_finish_ctx (&ctx
, checksum_before_op0
);
13433 md5_init_ctx (&ctx
);
13434 fold_checksum_tree (op1
, &ctx
, ht
);
13435 md5_finish_ctx (&ctx
, checksum_before_op1
);
13439 tem
= fold_binary (code
, type
, op0
, op1
);
13441 tem
= build2_stat (code
, type
, op0
, op1 PASS_MEM_STAT
);
13443 #ifdef ENABLE_FOLD_CHECKING
13444 md5_init_ctx (&ctx
);
13445 fold_checksum_tree (op0
, &ctx
, ht
);
13446 md5_finish_ctx (&ctx
, checksum_after_op0
);
13449 if (memcmp (checksum_before_op0
, checksum_after_op0
, 16))
13450 fold_check_failed (op0
, tem
);
13452 md5_init_ctx (&ctx
);
13453 fold_checksum_tree (op1
, &ctx
, ht
);
13454 md5_finish_ctx (&ctx
, checksum_after_op1
);
13457 if (memcmp (checksum_before_op1
, checksum_after_op1
, 16))
13458 fold_check_failed (op1
, tem
);
13463 /* Fold a ternary tree expression with code CODE of type TYPE with
13464 operands OP0, OP1, and OP2. Return a folded expression if
13465 successful. Otherwise, return a tree expression with code CODE of
13466 type TYPE with operands OP0, OP1, and OP2. */
13469 fold_build3_stat (enum tree_code code
, tree type
, tree op0
, tree op1
, tree op2
13473 #ifdef ENABLE_FOLD_CHECKING
13474 unsigned char checksum_before_op0
[16],
13475 checksum_before_op1
[16],
13476 checksum_before_op2
[16],
13477 checksum_after_op0
[16],
13478 checksum_after_op1
[16],
13479 checksum_after_op2
[16];
13480 struct md5_ctx ctx
;
13483 ht
= htab_create (32, htab_hash_pointer
, htab_eq_pointer
, NULL
);
13484 md5_init_ctx (&ctx
);
13485 fold_checksum_tree (op0
, &ctx
, ht
);
13486 md5_finish_ctx (&ctx
, checksum_before_op0
);
13489 md5_init_ctx (&ctx
);
13490 fold_checksum_tree (op1
, &ctx
, ht
);
13491 md5_finish_ctx (&ctx
, checksum_before_op1
);
13494 md5_init_ctx (&ctx
);
13495 fold_checksum_tree (op2
, &ctx
, ht
);
13496 md5_finish_ctx (&ctx
, checksum_before_op2
);
13500 gcc_assert (TREE_CODE_CLASS (code
) != tcc_vl_exp
);
13501 tem
= fold_ternary (code
, type
, op0
, op1
, op2
);
13503 tem
= build3_stat (code
, type
, op0
, op1
, op2 PASS_MEM_STAT
);
13505 #ifdef ENABLE_FOLD_CHECKING
13506 md5_init_ctx (&ctx
);
13507 fold_checksum_tree (op0
, &ctx
, ht
);
13508 md5_finish_ctx (&ctx
, checksum_after_op0
);
13511 if (memcmp (checksum_before_op0
, checksum_after_op0
, 16))
13512 fold_check_failed (op0
, tem
);
13514 md5_init_ctx (&ctx
);
13515 fold_checksum_tree (op1
, &ctx
, ht
);
13516 md5_finish_ctx (&ctx
, checksum_after_op1
);
13519 if (memcmp (checksum_before_op1
, checksum_after_op1
, 16))
13520 fold_check_failed (op1
, tem
);
13522 md5_init_ctx (&ctx
);
13523 fold_checksum_tree (op2
, &ctx
, ht
);
13524 md5_finish_ctx (&ctx
, checksum_after_op2
);
13527 if (memcmp (checksum_before_op2
, checksum_after_op2
, 16))
13528 fold_check_failed (op2
, tem
);
13533 /* Fold a CALL_EXPR expression of type TYPE with operands FN and NARGS
13534 arguments in ARGARRAY, and a null static chain.
13535 Return a folded expression if successful. Otherwise, return a CALL_EXPR
13536 of type TYPE from the given operands as constructed by build_call_array. */
13539 fold_build_call_array (tree type
, tree fn
, int nargs
, tree
*argarray
)
13542 #ifdef ENABLE_FOLD_CHECKING
13543 unsigned char checksum_before_fn
[16],
13544 checksum_before_arglist
[16],
13545 checksum_after_fn
[16],
13546 checksum_after_arglist
[16];
13547 struct md5_ctx ctx
;
13551 ht
= htab_create (32, htab_hash_pointer
, htab_eq_pointer
, NULL
);
13552 md5_init_ctx (&ctx
);
13553 fold_checksum_tree (fn
, &ctx
, ht
);
13554 md5_finish_ctx (&ctx
, checksum_before_fn
);
13557 md5_init_ctx (&ctx
);
13558 for (i
= 0; i
< nargs
; i
++)
13559 fold_checksum_tree (argarray
[i
], &ctx
, ht
);
13560 md5_finish_ctx (&ctx
, checksum_before_arglist
);
13564 tem
= fold_builtin_call_array (type
, fn
, nargs
, argarray
);
13566 #ifdef ENABLE_FOLD_CHECKING
13567 md5_init_ctx (&ctx
);
13568 fold_checksum_tree (fn
, &ctx
, ht
);
13569 md5_finish_ctx (&ctx
, checksum_after_fn
);
13572 if (memcmp (checksum_before_fn
, checksum_after_fn
, 16))
13573 fold_check_failed (fn
, tem
);
13575 md5_init_ctx (&ctx
);
13576 for (i
= 0; i
< nargs
; i
++)
13577 fold_checksum_tree (argarray
[i
], &ctx
, ht
);
13578 md5_finish_ctx (&ctx
, checksum_after_arglist
);
13581 if (memcmp (checksum_before_arglist
, checksum_after_arglist
, 16))
13582 fold_check_failed (NULL_TREE
, tem
);
13587 /* Perform constant folding and related simplification of initializer
13588 expression EXPR. These behave identically to "fold_buildN" but ignore
13589 potential run-time traps and exceptions that fold must preserve. */
13591 #define START_FOLD_INIT \
13592 int saved_signaling_nans = flag_signaling_nans;\
13593 int saved_trapping_math = flag_trapping_math;\
13594 int saved_rounding_math = flag_rounding_math;\
13595 int saved_trapv = flag_trapv;\
13596 int saved_folding_initializer = folding_initializer;\
13597 flag_signaling_nans = 0;\
13598 flag_trapping_math = 0;\
13599 flag_rounding_math = 0;\
13601 folding_initializer = 1;
13603 #define END_FOLD_INIT \
13604 flag_signaling_nans = saved_signaling_nans;\
13605 flag_trapping_math = saved_trapping_math;\
13606 flag_rounding_math = saved_rounding_math;\
13607 flag_trapv = saved_trapv;\
13608 folding_initializer = saved_folding_initializer;
13611 fold_build1_initializer (enum tree_code code
, tree type
, tree op
)
13616 result
= fold_build1 (code
, type
, op
);
13623 fold_build2_initializer (enum tree_code code
, tree type
, tree op0
, tree op1
)
13628 result
= fold_build2 (code
, type
, op0
, op1
);
13635 fold_build3_initializer (enum tree_code code
, tree type
, tree op0
, tree op1
,
13641 result
= fold_build3 (code
, type
, op0
, op1
, op2
);
13648 fold_build_call_array_initializer (tree type
, tree fn
,
13649 int nargs
, tree
*argarray
)
13654 result
= fold_build_call_array (type
, fn
, nargs
, argarray
);
13660 #undef START_FOLD_INIT
13661 #undef END_FOLD_INIT
13663 /* Determine if first argument is a multiple of second argument. Return 0 if
13664 it is not, or we cannot easily determined it to be.
13666 An example of the sort of thing we care about (at this point; this routine
13667 could surely be made more general, and expanded to do what the *_DIV_EXPR's
13668 fold cases do now) is discovering that
13670 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13676 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
13678 This code also handles discovering that
13680 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13682 is a multiple of 8 so we don't have to worry about dealing with a
13683 possible remainder.
13685 Note that we *look* inside a SAVE_EXPR only to determine how it was
13686 calculated; it is not safe for fold to do much of anything else with the
13687 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
13688 at run time. For example, the latter example above *cannot* be implemented
13689 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
13690 evaluation time of the original SAVE_EXPR is not necessarily the same at
13691 the time the new expression is evaluated. The only optimization of this
13692 sort that would be valid is changing
13694 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
13698 SAVE_EXPR (I) * SAVE_EXPR (J)
13700 (where the same SAVE_EXPR (J) is used in the original and the
13701 transformed version). */
13704 multiple_of_p (tree type
, tree top
, tree bottom
)
13706 if (operand_equal_p (top
, bottom
, 0))
13709 if (TREE_CODE (type
) != INTEGER_TYPE
)
13712 switch (TREE_CODE (top
))
13715 /* Bitwise and provides a power of two multiple. If the mask is
13716 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
13717 if (!integer_pow2p (bottom
))
13722 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
13723 || multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
13727 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
13728 && multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
13731 if (TREE_CODE (TREE_OPERAND (top
, 1)) == INTEGER_CST
)
13735 op1
= TREE_OPERAND (top
, 1);
13736 /* const_binop may not detect overflow correctly,
13737 so check for it explicitly here. */
13738 if (TYPE_PRECISION (TREE_TYPE (size_one_node
))
13739 > TREE_INT_CST_LOW (op1
)
13740 && TREE_INT_CST_HIGH (op1
) == 0
13741 && 0 != (t1
= fold_convert (type
,
13742 const_binop (LSHIFT_EXPR
,
13745 && !TREE_OVERFLOW (t1
))
13746 return multiple_of_p (type
, t1
, bottom
);
13751 /* Can't handle conversions from non-integral or wider integral type. */
13752 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top
, 0))) != INTEGER_TYPE
)
13753 || (TYPE_PRECISION (type
)
13754 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top
, 0)))))
13757 /* .. fall through ... */
13760 return multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
);
13763 if (TREE_CODE (bottom
) != INTEGER_CST
13764 || integer_zerop (bottom
)
13765 || (TYPE_UNSIGNED (type
)
13766 && (tree_int_cst_sgn (top
) < 0
13767 || tree_int_cst_sgn (bottom
) < 0)))
13769 return integer_zerop (int_const_binop (TRUNC_MOD_EXPR
,
13777 /* Return true if `t' is known to be non-negative. If the return
13778 value is based on the assumption that signed overflow is undefined,
13779 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13780 *STRICT_OVERFLOW_P. */
13783 tree_expr_nonnegative_warnv_p (tree t
, bool *strict_overflow_p
)
13785 if (t
== error_mark_node
)
13788 if (TYPE_UNSIGNED (TREE_TYPE (t
)))
13791 switch (TREE_CODE (t
))
13794 /* Query VRP to see if it has recorded any information about
13795 the range of this object. */
13796 return ssa_name_nonnegative_p (t
);
13799 /* We can't return 1 if flag_wrapv is set because
13800 ABS_EXPR<INT_MIN> = INT_MIN. */
13801 if (!INTEGRAL_TYPE_P (TREE_TYPE (t
)))
13803 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t
)))
13805 *strict_overflow_p
= true;
13811 return tree_int_cst_sgn (t
) >= 0;
13814 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t
));
13817 return ! FIXED_VALUE_NEGATIVE (TREE_FIXED_CST (t
));
13819 case POINTER_PLUS_EXPR
:
13821 if (FLOAT_TYPE_P (TREE_TYPE (t
)))
13822 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t
, 0),
13824 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t
, 1),
13825 strict_overflow_p
));
13827 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
13828 both unsigned and at least 2 bits shorter than the result. */
13829 if (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
13830 && TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
13831 && TREE_CODE (TREE_OPERAND (t
, 1)) == NOP_EXPR
)
13833 tree inner1
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
13834 tree inner2
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0));
13835 if (TREE_CODE (inner1
) == INTEGER_TYPE
&& TYPE_UNSIGNED (inner1
)
13836 && TREE_CODE (inner2
) == INTEGER_TYPE
&& TYPE_UNSIGNED (inner2
))
13838 unsigned int prec
= MAX (TYPE_PRECISION (inner1
),
13839 TYPE_PRECISION (inner2
)) + 1;
13840 return prec
< TYPE_PRECISION (TREE_TYPE (t
));
13846 if (FLOAT_TYPE_P (TREE_TYPE (t
)))
13848 /* x * x for floating point x is always non-negative. */
13849 if (operand_equal_p (TREE_OPERAND (t
, 0), TREE_OPERAND (t
, 1), 0))
13851 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t
, 0),
13853 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t
, 1),
13854 strict_overflow_p
));
13857 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
13858 both unsigned and their total bits is shorter than the result. */
13859 if (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
13860 && TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
13861 && TREE_CODE (TREE_OPERAND (t
, 1)) == NOP_EXPR
)
13863 tree inner1
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
13864 tree inner2
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0));
13865 if (TREE_CODE (inner1
) == INTEGER_TYPE
&& TYPE_UNSIGNED (inner1
)
13866 && TREE_CODE (inner2
) == INTEGER_TYPE
&& TYPE_UNSIGNED (inner2
))
13867 return TYPE_PRECISION (inner1
) + TYPE_PRECISION (inner2
)
13868 < TYPE_PRECISION (TREE_TYPE (t
));
13874 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t
, 0),
13876 || tree_expr_nonnegative_warnv_p (TREE_OPERAND (t
, 1),
13877 strict_overflow_p
));
13883 case TRUNC_DIV_EXPR
:
13884 case CEIL_DIV_EXPR
:
13885 case FLOOR_DIV_EXPR
:
13886 case ROUND_DIV_EXPR
:
13887 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t
, 0),
13889 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t
, 1),
13890 strict_overflow_p
));
13892 case TRUNC_MOD_EXPR
:
13893 case CEIL_MOD_EXPR
:
13894 case FLOOR_MOD_EXPR
:
13895 case ROUND_MOD_EXPR
:
13897 case NON_LVALUE_EXPR
:
13899 case FIX_TRUNC_EXPR
:
13900 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t
, 0),
13901 strict_overflow_p
);
13903 case COMPOUND_EXPR
:
13905 case GIMPLE_MODIFY_STMT
:
13906 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t
, 1),
13907 strict_overflow_p
);
13910 return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t
, 1)),
13911 strict_overflow_p
);
13914 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t
, 1),
13916 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t
, 2),
13917 strict_overflow_p
));
13921 tree inner_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
13922 tree outer_type
= TREE_TYPE (t
);
13924 if (TREE_CODE (outer_type
) == REAL_TYPE
)
13926 if (TREE_CODE (inner_type
) == REAL_TYPE
)
13927 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t
, 0),
13928 strict_overflow_p
);
13929 if (TREE_CODE (inner_type
) == INTEGER_TYPE
)
13931 if (TYPE_UNSIGNED (inner_type
))
13933 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t
, 0),
13934 strict_overflow_p
);
13937 else if (TREE_CODE (outer_type
) == INTEGER_TYPE
)
13939 if (TREE_CODE (inner_type
) == REAL_TYPE
)
13940 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t
,0),
13941 strict_overflow_p
);
13942 if (TREE_CODE (inner_type
) == INTEGER_TYPE
)
13943 return TYPE_PRECISION (inner_type
) < TYPE_PRECISION (outer_type
)
13944 && TYPE_UNSIGNED (inner_type
);
13951 tree temp
= TARGET_EXPR_SLOT (t
);
13952 t
= TARGET_EXPR_INITIAL (t
);
13954 /* If the initializer is non-void, then it's a normal expression
13955 that will be assigned to the slot. */
13956 if (!VOID_TYPE_P (t
))
13957 return tree_expr_nonnegative_warnv_p (t
, strict_overflow_p
);
13959 /* Otherwise, the initializer sets the slot in some way. One common
13960 way is an assignment statement at the end of the initializer. */
13963 if (TREE_CODE (t
) == BIND_EXPR
)
13964 t
= expr_last (BIND_EXPR_BODY (t
));
13965 else if (TREE_CODE (t
) == TRY_FINALLY_EXPR
13966 || TREE_CODE (t
) == TRY_CATCH_EXPR
)
13967 t
= expr_last (TREE_OPERAND (t
, 0));
13968 else if (TREE_CODE (t
) == STATEMENT_LIST
)
13973 if ((TREE_CODE (t
) == MODIFY_EXPR
13974 || TREE_CODE (t
) == GIMPLE_MODIFY_STMT
)
13975 && GENERIC_TREE_OPERAND (t
, 0) == temp
)
13976 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t
, 1),
13977 strict_overflow_p
);
13984 tree fndecl
= get_callee_fndecl (t
);
13985 if (fndecl
&& DECL_BUILT_IN_CLASS (fndecl
) == BUILT_IN_NORMAL
)
13986 switch (DECL_FUNCTION_CODE (fndecl
))
13988 CASE_FLT_FN (BUILT_IN_ACOS
):
13989 CASE_FLT_FN (BUILT_IN_ACOSH
):
13990 CASE_FLT_FN (BUILT_IN_CABS
):
13991 CASE_FLT_FN (BUILT_IN_COSH
):
13992 CASE_FLT_FN (BUILT_IN_ERFC
):
13993 CASE_FLT_FN (BUILT_IN_EXP
):
13994 CASE_FLT_FN (BUILT_IN_EXP10
):
13995 CASE_FLT_FN (BUILT_IN_EXP2
):
13996 CASE_FLT_FN (BUILT_IN_FABS
):
13997 CASE_FLT_FN (BUILT_IN_FDIM
):
13998 CASE_FLT_FN (BUILT_IN_HYPOT
):
13999 CASE_FLT_FN (BUILT_IN_POW10
):
14000 CASE_INT_FN (BUILT_IN_FFS
):
14001 CASE_INT_FN (BUILT_IN_PARITY
):
14002 CASE_INT_FN (BUILT_IN_POPCOUNT
):
14003 case BUILT_IN_BSWAP32
:
14004 case BUILT_IN_BSWAP64
:
14008 CASE_FLT_FN (BUILT_IN_SQRT
):
14009 /* sqrt(-0.0) is -0.0. */
14010 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t
))))
14012 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t
, 0),
14013 strict_overflow_p
);
14015 CASE_FLT_FN (BUILT_IN_ASINH
):
14016 CASE_FLT_FN (BUILT_IN_ATAN
):
14017 CASE_FLT_FN (BUILT_IN_ATANH
):
14018 CASE_FLT_FN (BUILT_IN_CBRT
):
14019 CASE_FLT_FN (BUILT_IN_CEIL
):
14020 CASE_FLT_FN (BUILT_IN_ERF
):
14021 CASE_FLT_FN (BUILT_IN_EXPM1
):
14022 CASE_FLT_FN (BUILT_IN_FLOOR
):
14023 CASE_FLT_FN (BUILT_IN_FMOD
):
14024 CASE_FLT_FN (BUILT_IN_FREXP
):
14025 CASE_FLT_FN (BUILT_IN_LCEIL
):
14026 CASE_FLT_FN (BUILT_IN_LDEXP
):
14027 CASE_FLT_FN (BUILT_IN_LFLOOR
):
14028 CASE_FLT_FN (BUILT_IN_LLCEIL
):
14029 CASE_FLT_FN (BUILT_IN_LLFLOOR
):
14030 CASE_FLT_FN (BUILT_IN_LLRINT
):
14031 CASE_FLT_FN (BUILT_IN_LLROUND
):
14032 CASE_FLT_FN (BUILT_IN_LRINT
):
14033 CASE_FLT_FN (BUILT_IN_LROUND
):
14034 CASE_FLT_FN (BUILT_IN_MODF
):
14035 CASE_FLT_FN (BUILT_IN_NEARBYINT
):
14036 CASE_FLT_FN (BUILT_IN_RINT
):
14037 CASE_FLT_FN (BUILT_IN_ROUND
):
14038 CASE_FLT_FN (BUILT_IN_SCALB
):
14039 CASE_FLT_FN (BUILT_IN_SCALBLN
):
14040 CASE_FLT_FN (BUILT_IN_SCALBN
):
14041 CASE_FLT_FN (BUILT_IN_SIGNBIT
):
14042 CASE_FLT_FN (BUILT_IN_SIGNIFICAND
):
14043 CASE_FLT_FN (BUILT_IN_SINH
):
14044 CASE_FLT_FN (BUILT_IN_TANH
):
14045 CASE_FLT_FN (BUILT_IN_TRUNC
):
14046 /* True if the 1st argument is nonnegative. */
14047 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t
, 0),
14048 strict_overflow_p
);
14050 CASE_FLT_FN (BUILT_IN_FMAX
):
14051 /* True if the 1st OR 2nd arguments are nonnegative. */
14052 return (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t
, 0),
14054 || (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t
, 1),
14055 strict_overflow_p
)));
14057 CASE_FLT_FN (BUILT_IN_FMIN
):
14058 /* True if the 1st AND 2nd arguments are nonnegative. */
14059 return (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t
, 0),
14061 && (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t
, 1),
14062 strict_overflow_p
)));
14064 CASE_FLT_FN (BUILT_IN_COPYSIGN
):
14065 /* True if the 2nd argument is nonnegative. */
14066 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t
, 1),
14067 strict_overflow_p
);
14069 CASE_FLT_FN (BUILT_IN_POWI
):
14070 /* True if the 1st argument is nonnegative or the second
14071 argument is an even integer. */
14072 if (TREE_CODE (CALL_EXPR_ARG (t
, 1)) == INTEGER_CST
)
14074 tree arg1
= CALL_EXPR_ARG (t
, 1);
14075 if ((TREE_INT_CST_LOW (arg1
) & 1) == 0)
14078 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t
, 0),
14079 strict_overflow_p
);
14081 CASE_FLT_FN (BUILT_IN_POW
):
14082 /* True if the 1st argument is nonnegative or the second
14083 argument is an even integer valued real. */
14084 if (TREE_CODE (CALL_EXPR_ARG (t
, 1)) == REAL_CST
)
14089 c
= TREE_REAL_CST (CALL_EXPR_ARG (t
, 1));
14090 n
= real_to_integer (&c
);
14093 REAL_VALUE_TYPE cint
;
14094 real_from_integer (&cint
, VOIDmode
, n
,
14095 n
< 0 ? -1 : 0, 0);
14096 if (real_identical (&c
, &cint
))
14100 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t
, 0),
14101 strict_overflow_p
);
14108 /* ... fall through ... */
14112 tree type
= TREE_TYPE (t
);
14113 if ((TYPE_PRECISION (type
) != 1 || TYPE_UNSIGNED (type
))
14114 && truth_value_p (TREE_CODE (t
)))
14115 /* Truth values evaluate to 0 or 1, which is nonnegative unless we
14116 have a signed:1 type (where the value is -1 and 0). */
14121 /* We don't know sign of `t', so be conservative and return false. */
14125 /* Return true if `t' is known to be non-negative. Handle warnings
14126 about undefined signed overflow. */
14129 tree_expr_nonnegative_p (tree t
)
14131 bool ret
, strict_overflow_p
;
14133 strict_overflow_p
= false;
14134 ret
= tree_expr_nonnegative_warnv_p (t
, &strict_overflow_p
);
14135 if (strict_overflow_p
)
14136 fold_overflow_warning (("assuming signed overflow does not occur when "
14137 "determining that expression is always "
14139 WARN_STRICT_OVERFLOW_MISC
);
14143 /* Return true when T is an address and is known to be nonzero.
14144 For floating point we further ensure that T is not denormal.
14145 Similar logic is present in nonzero_address in rtlanal.h.
14147 If the return value is based on the assumption that signed overflow
14148 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14149 change *STRICT_OVERFLOW_P. */
14152 tree_expr_nonzero_warnv_p (tree t
, bool *strict_overflow_p
)
14154 tree type
= TREE_TYPE (t
);
14155 bool sub_strict_overflow_p
;
14157 /* Doing something useful for floating point would need more work. */
14158 if (!INTEGRAL_TYPE_P (type
) && !POINTER_TYPE_P (type
))
14161 switch (TREE_CODE (t
))
14164 /* Query VRP to see if it has recorded any information about
14165 the range of this object. */
14166 return ssa_name_nonzero_p (t
);
14169 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t
, 0),
14170 strict_overflow_p
);
14173 return !integer_zerop (t
);
14175 case POINTER_PLUS_EXPR
:
14177 if (TYPE_OVERFLOW_UNDEFINED (type
))
14179 /* With the presence of negative values it is hard
14180 to say something. */
14181 sub_strict_overflow_p
= false;
14182 if (!tree_expr_nonnegative_warnv_p (TREE_OPERAND (t
, 0),
14183 &sub_strict_overflow_p
)
14184 || !tree_expr_nonnegative_warnv_p (TREE_OPERAND (t
, 1),
14185 &sub_strict_overflow_p
))
14187 /* One of operands must be positive and the other non-negative. */
14188 /* We don't set *STRICT_OVERFLOW_P here: even if this value
14189 overflows, on a twos-complement machine the sum of two
14190 nonnegative numbers can never be zero. */
14191 return (tree_expr_nonzero_warnv_p (TREE_OPERAND (t
, 0),
14193 || tree_expr_nonzero_warnv_p (TREE_OPERAND (t
, 1),
14194 strict_overflow_p
));
14199 if (TYPE_OVERFLOW_UNDEFINED (type
))
14201 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t
, 0),
14203 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t
, 1),
14204 strict_overflow_p
))
14206 *strict_overflow_p
= true;
14214 tree inner_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
14215 tree outer_type
= TREE_TYPE (t
);
14217 return (TYPE_PRECISION (outer_type
) >= TYPE_PRECISION (inner_type
)
14218 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t
, 0),
14219 strict_overflow_p
));
14225 tree base
= get_base_address (TREE_OPERAND (t
, 0));
14230 /* Weak declarations may link to NULL. */
14231 if (VAR_OR_FUNCTION_DECL_P (base
))
14232 return !DECL_WEAK (base
);
14234 /* Constants are never weak. */
14235 if (CONSTANT_CLASS_P (base
))
14242 sub_strict_overflow_p
= false;
14243 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t
, 1),
14244 &sub_strict_overflow_p
)
14245 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t
, 2),
14246 &sub_strict_overflow_p
))
14248 if (sub_strict_overflow_p
)
14249 *strict_overflow_p
= true;
14255 sub_strict_overflow_p
= false;
14256 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t
, 0),
14257 &sub_strict_overflow_p
)
14258 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t
, 1),
14259 &sub_strict_overflow_p
))
14261 if (sub_strict_overflow_p
)
14262 *strict_overflow_p
= true;
14267 sub_strict_overflow_p
= false;
14268 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t
, 0),
14269 &sub_strict_overflow_p
))
14271 if (sub_strict_overflow_p
)
14272 *strict_overflow_p
= true;
14274 /* When both operands are nonzero, then MAX must be too. */
14275 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t
, 1),
14276 strict_overflow_p
))
14279 /* MAX where operand 0 is positive is positive. */
14280 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t
, 0),
14281 strict_overflow_p
);
14283 /* MAX where operand 1 is positive is positive. */
14284 else if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t
, 1),
14285 &sub_strict_overflow_p
)
14286 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t
, 1),
14287 &sub_strict_overflow_p
))
14289 if (sub_strict_overflow_p
)
14290 *strict_overflow_p
= true;
14295 case COMPOUND_EXPR
:
14297 case GIMPLE_MODIFY_STMT
:
14299 return tree_expr_nonzero_warnv_p (GENERIC_TREE_OPERAND (t
, 1),
14300 strict_overflow_p
);
14303 case NON_LVALUE_EXPR
:
14304 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t
, 0),
14305 strict_overflow_p
);
14308 return (tree_expr_nonzero_warnv_p (TREE_OPERAND (t
, 1),
14310 || tree_expr_nonzero_warnv_p (TREE_OPERAND (t
, 0),
14311 strict_overflow_p
));
14314 return alloca_call_p (t
);
14322 /* Return true when T is an address and is known to be nonzero.
14323 Handle warnings about undefined signed overflow. */
14326 tree_expr_nonzero_p (tree t
)
14328 bool ret
, strict_overflow_p
;
14330 strict_overflow_p
= false;
14331 ret
= tree_expr_nonzero_warnv_p (t
, &strict_overflow_p
);
14332 if (strict_overflow_p
)
14333 fold_overflow_warning (("assuming signed overflow does not occur when "
14334 "determining that expression is always "
14336 WARN_STRICT_OVERFLOW_MISC
);
14340 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
14341 attempt to fold the expression to a constant without modifying TYPE,
14344 If the expression could be simplified to a constant, then return
14345 the constant. If the expression would not be simplified to a
14346 constant, then return NULL_TREE. */
14349 fold_binary_to_constant (enum tree_code code
, tree type
, tree op0
, tree op1
)
14351 tree tem
= fold_binary (code
, type
, op0
, op1
);
14352 return (tem
&& TREE_CONSTANT (tem
)) ? tem
: NULL_TREE
;
14355 /* Given the components of a unary expression CODE, TYPE and OP0,
14356 attempt to fold the expression to a constant without modifying
14359 If the expression could be simplified to a constant, then return
14360 the constant. If the expression would not be simplified to a
14361 constant, then return NULL_TREE. */
14364 fold_unary_to_constant (enum tree_code code
, tree type
, tree op0
)
14366 tree tem
= fold_unary (code
, type
, op0
);
14367 return (tem
&& TREE_CONSTANT (tem
)) ? tem
: NULL_TREE
;
14370 /* If EXP represents referencing an element in a constant string
14371 (either via pointer arithmetic or array indexing), return the
14372 tree representing the value accessed, otherwise return NULL. */
14375 fold_read_from_constant_string (tree exp
)
14377 if ((TREE_CODE (exp
) == INDIRECT_REF
14378 || TREE_CODE (exp
) == ARRAY_REF
)
14379 && TREE_CODE (TREE_TYPE (exp
)) == INTEGER_TYPE
)
14381 tree exp1
= TREE_OPERAND (exp
, 0);
14385 if (TREE_CODE (exp
) == INDIRECT_REF
)
14386 string
= string_constant (exp1
, &index
);
14389 tree low_bound
= array_ref_low_bound (exp
);
14390 index
= fold_convert (sizetype
, TREE_OPERAND (exp
, 1));
14392 /* Optimize the special-case of a zero lower bound.
14394 We convert the low_bound to sizetype to avoid some problems
14395 with constant folding. (E.g. suppose the lower bound is 1,
14396 and its mode is QI. Without the conversion,l (ARRAY
14397 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
14398 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
14399 if (! integer_zerop (low_bound
))
14400 index
= size_diffop (index
, fold_convert (sizetype
, low_bound
));
14406 && TYPE_MODE (TREE_TYPE (exp
)) == TYPE_MODE (TREE_TYPE (TREE_TYPE (string
)))
14407 && TREE_CODE (string
) == STRING_CST
14408 && TREE_CODE (index
) == INTEGER_CST
14409 && compare_tree_int (index
, TREE_STRING_LENGTH (string
)) < 0
14410 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string
))))
14412 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string
)))) == 1))
14413 return build_int_cst_type (TREE_TYPE (exp
),
14414 (TREE_STRING_POINTER (string
)
14415 [TREE_INT_CST_LOW (index
)]));
14420 /* Return the tree for neg (ARG0) when ARG0 is known to be either
14421 an integer constant, real, or fixed-point constant.
14423 TYPE is the type of the result. */
14426 fold_negate_const (tree arg0
, tree type
)
14428 tree t
= NULL_TREE
;
14430 switch (TREE_CODE (arg0
))
14434 unsigned HOST_WIDE_INT low
;
14435 HOST_WIDE_INT high
;
14436 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
14437 TREE_INT_CST_HIGH (arg0
),
14439 t
= force_fit_type_double (type
, low
, high
, 1,
14440 (overflow
| TREE_OVERFLOW (arg0
))
14441 && !TYPE_UNSIGNED (type
));
14446 t
= build_real (type
, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
14451 FIXED_VALUE_TYPE f
;
14452 bool overflow_p
= fixed_arithmetic (&f
, NEGATE_EXPR
,
14453 &(TREE_FIXED_CST (arg0
)), NULL
,
14454 TYPE_SATURATING (type
));
14455 t
= build_fixed (type
, f
);
14456 /* Propagate overflow flags. */
14457 if (overflow_p
| TREE_OVERFLOW (arg0
))
14459 TREE_OVERFLOW (t
) = 1;
14460 TREE_CONSTANT_OVERFLOW (t
) = 1;
14462 else if (TREE_CONSTANT_OVERFLOW (arg0
))
14463 TREE_CONSTANT_OVERFLOW (t
) = 1;
14468 gcc_unreachable ();
14474 /* Return the tree for abs (ARG0) when ARG0 is known to be either
14475 an integer constant or real constant.
14477 TYPE is the type of the result. */
14480 fold_abs_const (tree arg0
, tree type
)
14482 tree t
= NULL_TREE
;
14484 switch (TREE_CODE (arg0
))
14487 /* If the value is unsigned, then the absolute value is
14488 the same as the ordinary value. */
14489 if (TYPE_UNSIGNED (type
))
14491 /* Similarly, if the value is non-negative. */
14492 else if (INT_CST_LT (integer_minus_one_node
, arg0
))
14494 /* If the value is negative, then the absolute value is
14498 unsigned HOST_WIDE_INT low
;
14499 HOST_WIDE_INT high
;
14500 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
14501 TREE_INT_CST_HIGH (arg0
),
14503 t
= force_fit_type_double (type
, low
, high
, -1,
14504 overflow
| TREE_OVERFLOW (arg0
));
14509 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0
)))
14510 t
= build_real (type
, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
14516 gcc_unreachable ();
14522 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
14523 constant. TYPE is the type of the result. */
14526 fold_not_const (tree arg0
, tree type
)
14528 tree t
= NULL_TREE
;
14530 gcc_assert (TREE_CODE (arg0
) == INTEGER_CST
);
14532 t
= force_fit_type_double (type
, ~TREE_INT_CST_LOW (arg0
),
14533 ~TREE_INT_CST_HIGH (arg0
), 0,
14534 TREE_OVERFLOW (arg0
));
14539 /* Given CODE, a relational operator, the target type, TYPE and two
14540 constant operands OP0 and OP1, return the result of the
14541 relational operation. If the result is not a compile time
14542 constant, then return NULL_TREE. */
14545 fold_relational_const (enum tree_code code
, tree type
, tree op0
, tree op1
)
14547 int result
, invert
;
14549 /* From here on, the only cases we handle are when the result is
14550 known to be a constant. */
14552 if (TREE_CODE (op0
) == REAL_CST
&& TREE_CODE (op1
) == REAL_CST
)
14554 const REAL_VALUE_TYPE
*c0
= TREE_REAL_CST_PTR (op0
);
14555 const REAL_VALUE_TYPE
*c1
= TREE_REAL_CST_PTR (op1
);
14557 /* Handle the cases where either operand is a NaN. */
14558 if (real_isnan (c0
) || real_isnan (c1
))
14568 case UNORDERED_EXPR
:
14582 if (flag_trapping_math
)
14588 gcc_unreachable ();
14591 return constant_boolean_node (result
, type
);
14594 return constant_boolean_node (real_compare (code
, c0
, c1
), type
);
14597 if (TREE_CODE (op0
) == FIXED_CST
&& TREE_CODE (op1
) == FIXED_CST
)
14599 const FIXED_VALUE_TYPE
*c0
= TREE_FIXED_CST_PTR (op0
);
14600 const FIXED_VALUE_TYPE
*c1
= TREE_FIXED_CST_PTR (op1
);
14601 return constant_boolean_node (fixed_compare (code
, c0
, c1
), type
);
14604 /* Handle equality/inequality of complex constants. */
14605 if (TREE_CODE (op0
) == COMPLEX_CST
&& TREE_CODE (op1
) == COMPLEX_CST
)
14607 tree rcond
= fold_relational_const (code
, type
,
14608 TREE_REALPART (op0
),
14609 TREE_REALPART (op1
));
14610 tree icond
= fold_relational_const (code
, type
,
14611 TREE_IMAGPART (op0
),
14612 TREE_IMAGPART (op1
));
14613 if (code
== EQ_EXPR
)
14614 return fold_build2 (TRUTH_ANDIF_EXPR
, type
, rcond
, icond
);
14615 else if (code
== NE_EXPR
)
14616 return fold_build2 (TRUTH_ORIF_EXPR
, type
, rcond
, icond
);
14621 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
14623 To compute GT, swap the arguments and do LT.
14624 To compute GE, do LT and invert the result.
14625 To compute LE, swap the arguments, do LT and invert the result.
14626 To compute NE, do EQ and invert the result.
14628 Therefore, the code below must handle only EQ and LT. */
14630 if (code
== LE_EXPR
|| code
== GT_EXPR
)
14635 code
= swap_tree_comparison (code
);
14638 /* Note that it is safe to invert for real values here because we
14639 have already handled the one case that it matters. */
14642 if (code
== NE_EXPR
|| code
== GE_EXPR
)
14645 code
= invert_tree_comparison (code
, false);
14648 /* Compute a result for LT or EQ if args permit;
14649 Otherwise return T. */
14650 if (TREE_CODE (op0
) == INTEGER_CST
&& TREE_CODE (op1
) == INTEGER_CST
)
14652 if (code
== EQ_EXPR
)
14653 result
= tree_int_cst_equal (op0
, op1
);
14654 else if (TYPE_UNSIGNED (TREE_TYPE (op0
)))
14655 result
= INT_CST_LT_UNSIGNED (op0
, op1
);
14657 result
= INT_CST_LT (op0
, op1
);
14664 return constant_boolean_node (result
, type
);
14667 /* If necessary, return a CLEANUP_POINT_EXPR for EXPR with the
14668 indicated TYPE. If no CLEANUP_POINT_EXPR is necessary, return EXPR
14672 fold_build_cleanup_point_expr (tree type
, tree expr
)
14674 /* If the expression does not have side effects then we don't have to wrap
14675 it with a cleanup point expression. */
14676 if (!TREE_SIDE_EFFECTS (expr
))
14679 /* If the expression is a return, check to see if the expression inside the
14680 return has no side effects or the right hand side of the modify expression
14681 inside the return. If either don't have side effects set we don't need to
14682 wrap the expression in a cleanup point expression. Note we don't check the
14683 left hand side of the modify because it should always be a return decl. */
14684 if (TREE_CODE (expr
) == RETURN_EXPR
)
14686 tree op
= TREE_OPERAND (expr
, 0);
14687 if (!op
|| !TREE_SIDE_EFFECTS (op
))
14689 op
= TREE_OPERAND (op
, 1);
14690 if (!TREE_SIDE_EFFECTS (op
))
14694 return build1 (CLEANUP_POINT_EXPR
, type
, expr
);
14697 /* Given a pointer value OP0 and a type TYPE, return a simplified version
14698 of an indirection through OP0, or NULL_TREE if no simplification is
14702 fold_indirect_ref_1 (tree type
, tree op0
)
14708 subtype
= TREE_TYPE (sub
);
14709 if (!POINTER_TYPE_P (subtype
))
14712 if (TREE_CODE (sub
) == ADDR_EXPR
)
14714 tree op
= TREE_OPERAND (sub
, 0);
14715 tree optype
= TREE_TYPE (op
);
14716 /* *&CONST_DECL -> to the value of the const decl. */
14717 if (TREE_CODE (op
) == CONST_DECL
)
14718 return DECL_INITIAL (op
);
14719 /* *&p => p; make sure to handle *&"str"[cst] here. */
14720 if (type
== optype
)
14722 tree fop
= fold_read_from_constant_string (op
);
14728 /* *(foo *)&fooarray => fooarray[0] */
14729 else if (TREE_CODE (optype
) == ARRAY_TYPE
14730 && type
== TREE_TYPE (optype
))
14732 tree type_domain
= TYPE_DOMAIN (optype
);
14733 tree min_val
= size_zero_node
;
14734 if (type_domain
&& TYPE_MIN_VALUE (type_domain
))
14735 min_val
= TYPE_MIN_VALUE (type_domain
);
14736 return build4 (ARRAY_REF
, type
, op
, min_val
, NULL_TREE
, NULL_TREE
);
14738 /* *(foo *)&complexfoo => __real__ complexfoo */
14739 else if (TREE_CODE (optype
) == COMPLEX_TYPE
14740 && type
== TREE_TYPE (optype
))
14741 return fold_build1 (REALPART_EXPR
, type
, op
);
14742 /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */
14743 else if (TREE_CODE (optype
) == VECTOR_TYPE
14744 && type
== TREE_TYPE (optype
))
14746 tree part_width
= TYPE_SIZE (type
);
14747 tree index
= bitsize_int (0);
14748 return fold_build3 (BIT_FIELD_REF
, type
, op
, part_width
, index
);
14752 /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
14753 if (TREE_CODE (sub
) == POINTER_PLUS_EXPR
14754 && TREE_CODE (TREE_OPERAND (sub
, 1)) == INTEGER_CST
)
14756 tree op00
= TREE_OPERAND (sub
, 0);
14757 tree op01
= TREE_OPERAND (sub
, 1);
14761 op00type
= TREE_TYPE (op00
);
14762 if (TREE_CODE (op00
) == ADDR_EXPR
14763 && TREE_CODE (TREE_TYPE (op00type
)) == COMPLEX_TYPE
14764 && type
== TREE_TYPE (TREE_TYPE (op00type
)))
14766 tree size
= TYPE_SIZE_UNIT (type
);
14767 if (tree_int_cst_equal (size
, op01
))
14768 return fold_build1 (IMAGPART_EXPR
, type
, TREE_OPERAND (op00
, 0));
14772 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
14773 if (TREE_CODE (TREE_TYPE (subtype
)) == ARRAY_TYPE
14774 && type
== TREE_TYPE (TREE_TYPE (subtype
)))
14777 tree min_val
= size_zero_node
;
14778 sub
= build_fold_indirect_ref (sub
);
14779 type_domain
= TYPE_DOMAIN (TREE_TYPE (sub
));
14780 if (type_domain
&& TYPE_MIN_VALUE (type_domain
))
14781 min_val
= TYPE_MIN_VALUE (type_domain
);
14782 return build4 (ARRAY_REF
, type
, sub
, min_val
, NULL_TREE
, NULL_TREE
);
14788 /* Builds an expression for an indirection through T, simplifying some
14792 build_fold_indirect_ref (tree t
)
14794 tree type
= TREE_TYPE (TREE_TYPE (t
));
14795 tree sub
= fold_indirect_ref_1 (type
, t
);
14800 return build1 (INDIRECT_REF
, type
, t
);
14803 /* Given an INDIRECT_REF T, return either T or a simplified version. */
14806 fold_indirect_ref (tree t
)
14808 tree sub
= fold_indirect_ref_1 (TREE_TYPE (t
), TREE_OPERAND (t
, 0));
14816 /* Strip non-trapping, non-side-effecting tree nodes from an expression
14817 whose result is ignored. The type of the returned tree need not be
14818 the same as the original expression. */
14821 fold_ignored_result (tree t
)
14823 if (!TREE_SIDE_EFFECTS (t
))
14824 return integer_zero_node
;
14827 switch (TREE_CODE_CLASS (TREE_CODE (t
)))
14830 t
= TREE_OPERAND (t
, 0);
14834 case tcc_comparison
:
14835 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 1)))
14836 t
= TREE_OPERAND (t
, 0);
14837 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 0)))
14838 t
= TREE_OPERAND (t
, 1);
14843 case tcc_expression
:
14844 switch (TREE_CODE (t
))
14846 case COMPOUND_EXPR
:
14847 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 1)))
14849 t
= TREE_OPERAND (t
, 0);
14853 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 1))
14854 || TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 2)))
14856 t
= TREE_OPERAND (t
, 0);
14869 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
14870 This can only be applied to objects of a sizetype. */
14873 round_up (tree value
, int divisor
)
14875 tree div
= NULL_TREE
;
14877 gcc_assert (divisor
> 0);
14881 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
14882 have to do anything. Only do this when we are not given a const,
14883 because in that case, this check is more expensive than just
14885 if (TREE_CODE (value
) != INTEGER_CST
)
14887 div
= build_int_cst (TREE_TYPE (value
), divisor
);
14889 if (multiple_of_p (TREE_TYPE (value
), value
, div
))
14893 /* If divisor is a power of two, simplify this to bit manipulation. */
14894 if (divisor
== (divisor
& -divisor
))
14896 if (TREE_CODE (value
) == INTEGER_CST
)
14898 unsigned HOST_WIDE_INT low
= TREE_INT_CST_LOW (value
);
14899 unsigned HOST_WIDE_INT high
;
14902 if ((low
& (divisor
- 1)) == 0)
14905 overflow_p
= TREE_OVERFLOW (value
);
14906 high
= TREE_INT_CST_HIGH (value
);
14907 low
&= ~(divisor
- 1);
14916 return force_fit_type_double (TREE_TYPE (value
), low
, high
,
14923 t
= build_int_cst (TREE_TYPE (value
), divisor
- 1);
14924 value
= size_binop (PLUS_EXPR
, value
, t
);
14925 t
= build_int_cst (TREE_TYPE (value
), -divisor
);
14926 value
= size_binop (BIT_AND_EXPR
, value
, t
);
14932 div
= build_int_cst (TREE_TYPE (value
), divisor
);
14933 value
= size_binop (CEIL_DIV_EXPR
, value
, div
);
14934 value
= size_binop (MULT_EXPR
, value
, div
);
14940 /* Likewise, but round down. */
14943 round_down (tree value
, int divisor
)
14945 tree div
= NULL_TREE
;
14947 gcc_assert (divisor
> 0);
14951 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
14952 have to do anything. Only do this when we are not given a const,
14953 because in that case, this check is more expensive than just
14955 if (TREE_CODE (value
) != INTEGER_CST
)
14957 div
= build_int_cst (TREE_TYPE (value
), divisor
);
14959 if (multiple_of_p (TREE_TYPE (value
), value
, div
))
14963 /* If divisor is a power of two, simplify this to bit manipulation. */
14964 if (divisor
== (divisor
& -divisor
))
14968 t
= build_int_cst (TREE_TYPE (value
), -divisor
);
14969 value
= size_binop (BIT_AND_EXPR
, value
, t
);
14974 div
= build_int_cst (TREE_TYPE (value
), divisor
);
14975 value
= size_binop (FLOOR_DIV_EXPR
, value
, div
);
14976 value
= size_binop (MULT_EXPR
, value
, div
);
14982 /* Returns the pointer to the base of the object addressed by EXP and
14983 extracts the information about the offset of the access, storing it
14984 to PBITPOS and POFFSET. */
14987 split_address_to_core_and_offset (tree exp
,
14988 HOST_WIDE_INT
*pbitpos
, tree
*poffset
)
14991 enum machine_mode mode
;
14992 int unsignedp
, volatilep
;
14993 HOST_WIDE_INT bitsize
;
14995 if (TREE_CODE (exp
) == ADDR_EXPR
)
14997 core
= get_inner_reference (TREE_OPERAND (exp
, 0), &bitsize
, pbitpos
,
14998 poffset
, &mode
, &unsignedp
, &volatilep
,
15000 core
= fold_addr_expr (core
);
15006 *poffset
= NULL_TREE
;
15012 /* Returns true if addresses of E1 and E2 differ by a constant, false
15013 otherwise. If they do, E1 - E2 is stored in *DIFF. */
15016 ptr_difference_const (tree e1
, tree e2
, HOST_WIDE_INT
*diff
)
15019 HOST_WIDE_INT bitpos1
, bitpos2
;
15020 tree toffset1
, toffset2
, tdiff
, type
;
15022 core1
= split_address_to_core_and_offset (e1
, &bitpos1
, &toffset1
);
15023 core2
= split_address_to_core_and_offset (e2
, &bitpos2
, &toffset2
);
15025 if (bitpos1
% BITS_PER_UNIT
!= 0
15026 || bitpos2
% BITS_PER_UNIT
!= 0
15027 || !operand_equal_p (core1
, core2
, 0))
15030 if (toffset1
&& toffset2
)
15032 type
= TREE_TYPE (toffset1
);
15033 if (type
!= TREE_TYPE (toffset2
))
15034 toffset2
= fold_convert (type
, toffset2
);
15036 tdiff
= fold_build2 (MINUS_EXPR
, type
, toffset1
, toffset2
);
15037 if (!cst_and_fits_in_hwi (tdiff
))
15040 *diff
= int_cst_value (tdiff
);
15042 else if (toffset1
|| toffset2
)
15044 /* If only one of the offsets is non-constant, the difference cannot
15051 *diff
+= (bitpos1
- bitpos2
) / BITS_PER_UNIT
;
15055 /* Simplify the floating point expression EXP when the sign of the
15056 result is not significant. Return NULL_TREE if no simplification
15060 fold_strip_sign_ops (tree exp
)
15064 switch (TREE_CODE (exp
))
15068 arg0
= fold_strip_sign_ops (TREE_OPERAND (exp
, 0));
15069 return arg0
? arg0
: TREE_OPERAND (exp
, 0);
15073 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp
))))
15075 arg0
= fold_strip_sign_ops (TREE_OPERAND (exp
, 0));
15076 arg1
= fold_strip_sign_ops (TREE_OPERAND (exp
, 1));
15077 if (arg0
!= NULL_TREE
|| arg1
!= NULL_TREE
)
15078 return fold_build2 (TREE_CODE (exp
), TREE_TYPE (exp
),
15079 arg0
? arg0
: TREE_OPERAND (exp
, 0),
15080 arg1
? arg1
: TREE_OPERAND (exp
, 1));
15083 case COMPOUND_EXPR
:
15084 arg0
= TREE_OPERAND (exp
, 0);
15085 arg1
= fold_strip_sign_ops (TREE_OPERAND (exp
, 1));
15087 return fold_build2 (COMPOUND_EXPR
, TREE_TYPE (exp
), arg0
, arg1
);
15091 arg0
= fold_strip_sign_ops (TREE_OPERAND (exp
, 1));
15092 arg1
= fold_strip_sign_ops (TREE_OPERAND (exp
, 2));
15094 return fold_build3 (COND_EXPR
, TREE_TYPE (exp
), TREE_OPERAND (exp
, 0),
15095 arg0
? arg0
: TREE_OPERAND (exp
, 1),
15096 arg1
? arg1
: TREE_OPERAND (exp
, 2));
15101 const enum built_in_function fcode
= builtin_mathfn_code (exp
);
15104 CASE_FLT_FN (BUILT_IN_COPYSIGN
):
15105 /* Strip copysign function call, return the 1st argument. */
15106 arg0
= CALL_EXPR_ARG (exp
, 0);
15107 arg1
= CALL_EXPR_ARG (exp
, 1);
15108 return omit_one_operand (TREE_TYPE (exp
), arg0
, arg1
);
15111 /* Strip sign ops from the argument of "odd" math functions. */
15112 if (negate_mathfn_p (fcode
))
15114 arg0
= fold_strip_sign_ops (CALL_EXPR_ARG (exp
, 0));
15116 return build_call_expr (get_callee_fndecl (exp
), 1, arg0
);