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 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
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
33 fold takes a tree as argument and returns a simplified tree.
35 size_binop takes a tree code for an arithmetic operation
36 and two operands that are trees, and produces a tree for the
37 result, assuming the type comes from `sizetype'.
39 size_int takes an integer value, and creates a tree constant
40 with type from `sizetype'.
42 force_fit_type takes a constant, an overflowable flag and prior
43 overflow indicators. It forces the value to fit the type and sets
44 TREE_OVERFLOW and TREE_CONSTANT_OVERFLOW as appropriate. */
48 #include "coretypes.h"
59 #include "langhooks.h"
62 /* The following constants represent a bit based encoding of GCC's
63 comparison operators. This encoding simplifies transformations
64 on relational comparison operators, such as AND and OR. */
65 enum comparison_code
{
84 static void encode (HOST_WIDE_INT
*, unsigned HOST_WIDE_INT
, HOST_WIDE_INT
);
85 static void decode (HOST_WIDE_INT
*, unsigned HOST_WIDE_INT
*, HOST_WIDE_INT
*);
86 static bool negate_mathfn_p (enum built_in_function
);
87 static bool negate_expr_p (tree
);
88 static tree
negate_expr (tree
);
89 static tree
split_tree (tree
, enum tree_code
, tree
*, tree
*, tree
*, int);
90 static tree
associate_trees (tree
, tree
, enum tree_code
, tree
);
91 static tree
const_binop (enum tree_code
, tree
, tree
, int);
92 static tree
build_zero_vector (tree
);
93 static tree
fold_convert_const (enum tree_code
, tree
, tree
);
94 static enum tree_code
invert_tree_comparison (enum tree_code
, bool);
95 static enum comparison_code
comparison_to_compcode (enum tree_code
);
96 static enum tree_code
compcode_to_comparison (enum comparison_code
);
97 static tree
combine_comparisons (enum tree_code
, enum tree_code
,
98 enum tree_code
, tree
, tree
, tree
);
99 static int truth_value_p (enum tree_code
);
100 static int operand_equal_for_comparison_p (tree
, tree
, tree
);
101 static int twoval_comparison_p (tree
, tree
*, tree
*, int *);
102 static tree
eval_subst (tree
, tree
, tree
, tree
, tree
);
103 static tree
pedantic_omit_one_operand (tree
, tree
, tree
);
104 static tree
distribute_bit_expr (enum tree_code
, tree
, tree
, tree
);
105 static tree
make_bit_field_ref (tree
, tree
, int, int, int);
106 static tree
optimize_bit_field_compare (enum tree_code
, tree
, tree
, tree
);
107 static tree
decode_field_reference (tree
, HOST_WIDE_INT
*, HOST_WIDE_INT
*,
108 enum machine_mode
*, int *, int *,
110 static int all_ones_mask_p (tree
, int);
111 static tree
sign_bit_p (tree
, tree
);
112 static int simple_operand_p (tree
);
113 static tree
range_binop (enum tree_code
, tree
, tree
, int, tree
, int);
114 static tree
make_range (tree
, int *, tree
*, tree
*);
115 static tree
build_range_check (tree
, tree
, int, tree
, tree
);
116 static int merge_ranges (int *, tree
*, tree
*, int, tree
, tree
, int, tree
,
118 static tree
fold_range_test (tree
);
119 static tree
fold_cond_expr_with_comparison (tree
, tree
, tree
, tree
);
120 static tree
unextend (tree
, int, int, tree
);
121 static tree
fold_truthop (enum tree_code
, tree
, tree
, tree
);
122 static tree
optimize_minmax_comparison (tree
);
123 static tree
extract_muldiv (tree
, tree
, enum tree_code
, tree
);
124 static tree
extract_muldiv_1 (tree
, tree
, enum tree_code
, tree
);
125 static int multiple_of_p (tree
, tree
, tree
);
126 static tree
fold_binary_op_with_conditional_arg (enum tree_code
, tree
, tree
,
128 static bool fold_real_zero_addition_p (tree
, tree
, int);
129 static tree
fold_mathfn_compare (enum built_in_function
, enum tree_code
,
131 static tree
fold_inf_compare (enum tree_code
, tree
, tree
, tree
);
132 static tree
fold_div_compare (enum tree_code
, tree
, tree
, tree
);
133 static bool reorder_operands_p (tree
, tree
);
134 static tree
fold_negate_const (tree
, tree
);
135 static tree
fold_not_const (tree
, tree
);
136 static tree
fold_relational_const (enum tree_code
, tree
, tree
, tree
);
137 static tree
fold_relational_hi_lo (enum tree_code
*, const tree
,
139 static bool tree_expr_nonzero_p (tree
);
141 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
142 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
143 and SUM1. Then this yields nonzero if overflow occurred during the
146 Overflow occurs if A and B have the same sign, but A and SUM differ in
147 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
149 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
151 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
152 We do that by representing the two-word integer in 4 words, with only
153 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
154 number. The value of the word is LOWPART + HIGHPART * BASE. */
157 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
158 #define HIGHPART(x) \
159 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
160 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
162 /* Unpack a two-word integer into 4 words.
163 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
164 WORDS points to the array of HOST_WIDE_INTs. */
167 encode (HOST_WIDE_INT
*words
, unsigned HOST_WIDE_INT low
, HOST_WIDE_INT hi
)
169 words
[0] = LOWPART (low
);
170 words
[1] = HIGHPART (low
);
171 words
[2] = LOWPART (hi
);
172 words
[3] = HIGHPART (hi
);
175 /* Pack an array of 4 words into a two-word integer.
176 WORDS points to the array of words.
177 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
180 decode (HOST_WIDE_INT
*words
, unsigned HOST_WIDE_INT
*low
,
183 *low
= words
[0] + words
[1] * BASE
;
184 *hi
= words
[2] + words
[3] * BASE
;
187 /* T is an INT_CST node. OVERFLOWABLE indicates if we are interested
188 in overflow of the value, when >0 we are only interested in signed
189 overflow, for <0 we are interested in any overflow. OVERFLOWED
190 indicates whether overflow has already occurred. CONST_OVERFLOWED
191 indicates whether constant overflow has already occurred. We force
192 T's value to be within range of T's type (by setting to 0 or 1 all
193 the bits outside the type's range). We set TREE_OVERFLOWED if,
194 OVERFLOWED is nonzero,
195 or OVERFLOWABLE is >0 and signed overflow occurs
196 or OVERFLOWABLE is <0 and any overflow occurs
197 We set TREE_CONSTANT_OVERFLOWED if,
198 CONST_OVERFLOWED is nonzero
199 or we set TREE_OVERFLOWED.
200 We return either the original T, or a copy. */
203 force_fit_type (tree t
, int overflowable
,
204 bool overflowed
, bool overflowed_const
)
206 unsigned HOST_WIDE_INT low
;
209 int sign_extended_type
;
211 gcc_assert (TREE_CODE (t
) == INTEGER_CST
);
213 low
= TREE_INT_CST_LOW (t
);
214 high
= TREE_INT_CST_HIGH (t
);
216 if (POINTER_TYPE_P (TREE_TYPE (t
))
217 || TREE_CODE (TREE_TYPE (t
)) == OFFSET_TYPE
)
220 prec
= TYPE_PRECISION (TREE_TYPE (t
));
221 /* Size types *are* sign extended. */
222 sign_extended_type
= (!TYPE_UNSIGNED (TREE_TYPE (t
))
223 || (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
224 && TYPE_IS_SIZETYPE (TREE_TYPE (t
))));
226 /* First clear all bits that are beyond the type's precision. */
228 if (prec
== 2 * HOST_BITS_PER_WIDE_INT
)
230 else if (prec
> HOST_BITS_PER_WIDE_INT
)
231 high
&= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
235 if (prec
< HOST_BITS_PER_WIDE_INT
)
236 low
&= ~((HOST_WIDE_INT
) (-1) << prec
);
239 if (!sign_extended_type
)
240 /* No sign extension */;
241 else if (prec
== 2 * HOST_BITS_PER_WIDE_INT
)
242 /* Correct width already. */;
243 else if (prec
> HOST_BITS_PER_WIDE_INT
)
245 /* Sign extend top half? */
246 if (high
& ((unsigned HOST_WIDE_INT
)1
247 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)))
248 high
|= (HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
);
250 else if (prec
== HOST_BITS_PER_WIDE_INT
)
252 if ((HOST_WIDE_INT
)low
< 0)
257 /* Sign extend bottom half? */
258 if (low
& ((unsigned HOST_WIDE_INT
)1 << (prec
- 1)))
261 low
|= (HOST_WIDE_INT
)(-1) << prec
;
265 /* If the value changed, return a new node. */
266 if (overflowed
|| overflowed_const
267 || low
!= TREE_INT_CST_LOW (t
) || high
!= TREE_INT_CST_HIGH (t
))
269 t
= build_int_cst_wide (TREE_TYPE (t
), low
, high
);
273 || (overflowable
> 0 && sign_extended_type
))
276 TREE_OVERFLOW (t
) = 1;
277 TREE_CONSTANT_OVERFLOW (t
) = 1;
279 else if (overflowed_const
)
282 TREE_CONSTANT_OVERFLOW (t
) = 1;
289 /* Add two doubleword integers with doubleword result.
290 Each argument is given as two `HOST_WIDE_INT' pieces.
291 One argument is L1 and H1; the other, L2 and H2.
292 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
295 add_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
296 unsigned HOST_WIDE_INT l2
, HOST_WIDE_INT h2
,
297 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
299 unsigned HOST_WIDE_INT l
;
303 h
= h1
+ h2
+ (l
< l1
);
307 return OVERFLOW_SUM_SIGN (h1
, h2
, h
);
310 /* Negate a doubleword integer with doubleword result.
311 Return nonzero if the operation overflows, assuming it's signed.
312 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
313 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
316 neg_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
317 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
323 return (*hv
& h1
) < 0;
333 /* Multiply two doubleword integers with doubleword result.
334 Return nonzero if the operation overflows, assuming it's signed.
335 Each argument is given as two `HOST_WIDE_INT' pieces.
336 One argument is L1 and H1; the other, L2 and H2.
337 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
340 mul_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
341 unsigned HOST_WIDE_INT l2
, HOST_WIDE_INT h2
,
342 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
344 HOST_WIDE_INT arg1
[4];
345 HOST_WIDE_INT arg2
[4];
346 HOST_WIDE_INT prod
[4 * 2];
347 unsigned HOST_WIDE_INT carry
;
349 unsigned HOST_WIDE_INT toplow
, neglow
;
350 HOST_WIDE_INT tophigh
, neghigh
;
352 encode (arg1
, l1
, h1
);
353 encode (arg2
, l2
, h2
);
355 memset (prod
, 0, sizeof prod
);
357 for (i
= 0; i
< 4; i
++)
360 for (j
= 0; j
< 4; j
++)
363 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
364 carry
+= arg1
[i
] * arg2
[j
];
365 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
367 prod
[k
] = LOWPART (carry
);
368 carry
= HIGHPART (carry
);
373 decode (prod
, lv
, hv
); /* This ignores prod[4] through prod[4*2-1] */
375 /* Check for overflow by calculating the top half of the answer in full;
376 it should agree with the low half's sign bit. */
377 decode (prod
+ 4, &toplow
, &tophigh
);
380 neg_double (l2
, h2
, &neglow
, &neghigh
);
381 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
385 neg_double (l1
, h1
, &neglow
, &neghigh
);
386 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
388 return (*hv
< 0 ? ~(toplow
& tophigh
) : toplow
| tophigh
) != 0;
391 /* Shift the doubleword integer in L1, H1 left by COUNT places
392 keeping only PREC bits of result.
393 Shift right if COUNT is negative.
394 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
395 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
398 lshift_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
399 HOST_WIDE_INT count
, unsigned int prec
,
400 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
, int arith
)
402 unsigned HOST_WIDE_INT signmask
;
406 rshift_double (l1
, h1
, -count
, prec
, lv
, hv
, arith
);
410 if (SHIFT_COUNT_TRUNCATED
)
413 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
415 /* Shifting by the host word size is undefined according to the
416 ANSI standard, so we must handle this as a special case. */
420 else if (count
>= HOST_BITS_PER_WIDE_INT
)
422 *hv
= l1
<< (count
- HOST_BITS_PER_WIDE_INT
);
427 *hv
= (((unsigned HOST_WIDE_INT
) h1
<< count
)
428 | (l1
>> (HOST_BITS_PER_WIDE_INT
- count
- 1) >> 1));
432 /* Sign extend all bits that are beyond the precision. */
434 signmask
= -((prec
> HOST_BITS_PER_WIDE_INT
435 ? ((unsigned HOST_WIDE_INT
) *hv
436 >> (prec
- HOST_BITS_PER_WIDE_INT
- 1))
437 : (*lv
>> (prec
- 1))) & 1);
439 if (prec
>= 2 * HOST_BITS_PER_WIDE_INT
)
441 else if (prec
>= HOST_BITS_PER_WIDE_INT
)
443 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
444 *hv
|= signmask
<< (prec
- HOST_BITS_PER_WIDE_INT
);
449 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << prec
);
450 *lv
|= signmask
<< prec
;
454 /* Shift the doubleword integer in L1, H1 right by COUNT places
455 keeping only PREC bits of result. COUNT must be positive.
456 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
457 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
460 rshift_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
461 HOST_WIDE_INT count
, unsigned int prec
,
462 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
,
465 unsigned HOST_WIDE_INT signmask
;
468 ? -((unsigned HOST_WIDE_INT
) h1
>> (HOST_BITS_PER_WIDE_INT
- 1))
471 if (SHIFT_COUNT_TRUNCATED
)
474 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
476 /* Shifting by the host word size is undefined according to the
477 ANSI standard, so we must handle this as a special case. */
481 else if (count
>= HOST_BITS_PER_WIDE_INT
)
484 *lv
= (unsigned HOST_WIDE_INT
) h1
>> (count
- HOST_BITS_PER_WIDE_INT
);
488 *hv
= (unsigned HOST_WIDE_INT
) h1
>> count
;
490 | ((unsigned HOST_WIDE_INT
) h1
<< (HOST_BITS_PER_WIDE_INT
- count
- 1) << 1));
493 /* Zero / sign extend all bits that are beyond the precision. */
495 if (count
>= (HOST_WIDE_INT
)prec
)
500 else if ((prec
- count
) >= 2 * HOST_BITS_PER_WIDE_INT
)
502 else if ((prec
- count
) >= HOST_BITS_PER_WIDE_INT
)
504 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- count
- HOST_BITS_PER_WIDE_INT
));
505 *hv
|= signmask
<< (prec
- count
- HOST_BITS_PER_WIDE_INT
);
510 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << (prec
- count
));
511 *lv
|= signmask
<< (prec
- count
);
515 /* Rotate the doubleword integer in L1, H1 left by COUNT places
516 keeping only PREC bits of result.
517 Rotate right if COUNT is negative.
518 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
521 lrotate_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
522 HOST_WIDE_INT count
, unsigned int prec
,
523 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
525 unsigned HOST_WIDE_INT s1l
, s2l
;
526 HOST_WIDE_INT s1h
, s2h
;
532 lshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
533 rshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
538 /* Rotate the doubleword integer in L1, H1 left by COUNT places
539 keeping only PREC bits of result. COUNT must be positive.
540 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
543 rrotate_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
544 HOST_WIDE_INT count
, unsigned int prec
,
545 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
547 unsigned HOST_WIDE_INT s1l
, s2l
;
548 HOST_WIDE_INT s1h
, s2h
;
554 rshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
555 lshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
560 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
561 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
562 CODE is a tree code for a kind of division, one of
563 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
565 It controls how the quotient is rounded to an integer.
566 Return nonzero if the operation overflows.
567 UNS nonzero says do unsigned division. */
570 div_and_round_double (enum tree_code code
, int uns
,
571 unsigned HOST_WIDE_INT lnum_orig
, /* num == numerator == dividend */
572 HOST_WIDE_INT hnum_orig
,
573 unsigned HOST_WIDE_INT lden_orig
, /* den == denominator == divisor */
574 HOST_WIDE_INT hden_orig
,
575 unsigned HOST_WIDE_INT
*lquo
,
576 HOST_WIDE_INT
*hquo
, unsigned HOST_WIDE_INT
*lrem
,
580 HOST_WIDE_INT num
[4 + 1]; /* extra element for scaling. */
581 HOST_WIDE_INT den
[4], quo
[4];
583 unsigned HOST_WIDE_INT work
;
584 unsigned HOST_WIDE_INT carry
= 0;
585 unsigned HOST_WIDE_INT lnum
= lnum_orig
;
586 HOST_WIDE_INT hnum
= hnum_orig
;
587 unsigned HOST_WIDE_INT lden
= lden_orig
;
588 HOST_WIDE_INT hden
= hden_orig
;
591 if (hden
== 0 && lden
== 0)
592 overflow
= 1, lden
= 1;
594 /* Calculate quotient sign and convert operands to unsigned. */
600 /* (minimum integer) / (-1) is the only overflow case. */
601 if (neg_double (lnum
, hnum
, &lnum
, &hnum
)
602 && ((HOST_WIDE_INT
) lden
& hden
) == -1)
608 neg_double (lden
, hden
, &lden
, &hden
);
612 if (hnum
== 0 && hden
== 0)
613 { /* single precision */
615 /* This unsigned division rounds toward zero. */
621 { /* trivial case: dividend < divisor */
622 /* hden != 0 already checked. */
629 memset (quo
, 0, sizeof quo
);
631 memset (num
, 0, sizeof num
); /* to zero 9th element */
632 memset (den
, 0, sizeof den
);
634 encode (num
, lnum
, hnum
);
635 encode (den
, lden
, hden
);
637 /* Special code for when the divisor < BASE. */
638 if (hden
== 0 && lden
< (unsigned HOST_WIDE_INT
) BASE
)
640 /* hnum != 0 already checked. */
641 for (i
= 4 - 1; i
>= 0; i
--)
643 work
= num
[i
] + carry
* BASE
;
644 quo
[i
] = work
/ lden
;
650 /* Full double precision division,
651 with thanks to Don Knuth's "Seminumerical Algorithms". */
652 int num_hi_sig
, den_hi_sig
;
653 unsigned HOST_WIDE_INT quo_est
, scale
;
655 /* Find the highest nonzero divisor digit. */
656 for (i
= 4 - 1;; i
--)
663 /* Insure that the first digit of the divisor is at least BASE/2.
664 This is required by the quotient digit estimation algorithm. */
666 scale
= BASE
/ (den
[den_hi_sig
] + 1);
668 { /* scale divisor and dividend */
670 for (i
= 0; i
<= 4 - 1; i
++)
672 work
= (num
[i
] * scale
) + carry
;
673 num
[i
] = LOWPART (work
);
674 carry
= HIGHPART (work
);
679 for (i
= 0; i
<= 4 - 1; i
++)
681 work
= (den
[i
] * scale
) + carry
;
682 den
[i
] = LOWPART (work
);
683 carry
= HIGHPART (work
);
684 if (den
[i
] != 0) den_hi_sig
= i
;
691 for (i
= num_hi_sig
- den_hi_sig
- 1; i
>= 0; i
--)
693 /* Guess the next quotient digit, quo_est, by dividing the first
694 two remaining dividend digits by the high order quotient digit.
695 quo_est is never low and is at most 2 high. */
696 unsigned HOST_WIDE_INT tmp
;
698 num_hi_sig
= i
+ den_hi_sig
+ 1;
699 work
= num
[num_hi_sig
] * BASE
+ num
[num_hi_sig
- 1];
700 if (num
[num_hi_sig
] != den
[den_hi_sig
])
701 quo_est
= work
/ den
[den_hi_sig
];
705 /* Refine quo_est so it's usually correct, and at most one high. */
706 tmp
= work
- quo_est
* den
[den_hi_sig
];
708 && (den
[den_hi_sig
- 1] * quo_est
709 > (tmp
* BASE
+ num
[num_hi_sig
- 2])))
712 /* Try QUO_EST as the quotient digit, by multiplying the
713 divisor by QUO_EST and subtracting from the remaining dividend.
714 Keep in mind that QUO_EST is the I - 1st digit. */
717 for (j
= 0; j
<= den_hi_sig
; j
++)
719 work
= quo_est
* den
[j
] + carry
;
720 carry
= HIGHPART (work
);
721 work
= num
[i
+ j
] - LOWPART (work
);
722 num
[i
+ j
] = LOWPART (work
);
723 carry
+= HIGHPART (work
) != 0;
726 /* If quo_est was high by one, then num[i] went negative and
727 we need to correct things. */
728 if (num
[num_hi_sig
] < (HOST_WIDE_INT
) carry
)
731 carry
= 0; /* add divisor back in */
732 for (j
= 0; j
<= den_hi_sig
; j
++)
734 work
= num
[i
+ j
] + den
[j
] + carry
;
735 carry
= HIGHPART (work
);
736 num
[i
+ j
] = LOWPART (work
);
739 num
[num_hi_sig
] += carry
;
742 /* Store the quotient digit. */
747 decode (quo
, lquo
, hquo
);
750 /* If result is negative, make it so. */
752 neg_double (*lquo
, *hquo
, lquo
, hquo
);
754 /* Compute trial remainder: rem = num - (quo * den) */
755 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
756 neg_double (*lrem
, *hrem
, lrem
, hrem
);
757 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
762 case TRUNC_MOD_EXPR
: /* round toward zero */
763 case EXACT_DIV_EXPR
: /* for this one, it shouldn't matter */
767 case FLOOR_MOD_EXPR
: /* round toward negative infinity */
768 if (quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio < 0 && rem != 0 */
771 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1,
779 case CEIL_MOD_EXPR
: /* round toward positive infinity */
780 if (!quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio > 0 && rem != 0 */
782 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
790 case ROUND_MOD_EXPR
: /* round to closest integer */
792 unsigned HOST_WIDE_INT labs_rem
= *lrem
;
793 HOST_WIDE_INT habs_rem
= *hrem
;
794 unsigned HOST_WIDE_INT labs_den
= lden
, ltwice
;
795 HOST_WIDE_INT habs_den
= hden
, htwice
;
797 /* Get absolute values. */
799 neg_double (*lrem
, *hrem
, &labs_rem
, &habs_rem
);
801 neg_double (lden
, hden
, &labs_den
, &habs_den
);
803 /* If (2 * abs (lrem) >= abs (lden)) */
804 mul_double ((HOST_WIDE_INT
) 2, (HOST_WIDE_INT
) 0,
805 labs_rem
, habs_rem
, <wice
, &htwice
);
807 if (((unsigned HOST_WIDE_INT
) habs_den
808 < (unsigned HOST_WIDE_INT
) htwice
)
809 || (((unsigned HOST_WIDE_INT
) habs_den
810 == (unsigned HOST_WIDE_INT
) htwice
)
811 && (labs_den
< ltwice
)))
815 add_double (*lquo
, *hquo
,
816 (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1, lquo
, hquo
);
819 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
831 /* Compute true remainder: rem = num - (quo * den) */
832 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
833 neg_double (*lrem
, *hrem
, lrem
, hrem
);
834 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
838 /* Return true if built-in mathematical function specified by CODE
839 preserves the sign of it argument, i.e. -f(x) == f(-x). */
842 negate_mathfn_p (enum built_in_function code
)
866 /* Check whether we may negate an integer constant T without causing
870 may_negate_without_overflow_p (tree t
)
872 unsigned HOST_WIDE_INT val
;
876 gcc_assert (TREE_CODE (t
) == INTEGER_CST
);
878 type
= TREE_TYPE (t
);
879 if (TYPE_UNSIGNED (type
))
882 prec
= TYPE_PRECISION (type
);
883 if (prec
> HOST_BITS_PER_WIDE_INT
)
885 if (TREE_INT_CST_LOW (t
) != 0)
887 prec
-= HOST_BITS_PER_WIDE_INT
;
888 val
= TREE_INT_CST_HIGH (t
);
891 val
= TREE_INT_CST_LOW (t
);
892 if (prec
< HOST_BITS_PER_WIDE_INT
)
893 val
&= ((unsigned HOST_WIDE_INT
) 1 << prec
) - 1;
894 return val
!= ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1));
897 /* Determine whether an expression T can be cheaply negated using
898 the function negate_expr. */
901 negate_expr_p (tree t
)
908 type
= TREE_TYPE (t
);
911 switch (TREE_CODE (t
))
914 if (TYPE_UNSIGNED (type
) || ! flag_trapv
)
917 /* Check that -CST will not overflow type. */
918 return may_negate_without_overflow_p (t
);
925 return negate_expr_p (TREE_REALPART (t
))
926 && negate_expr_p (TREE_IMAGPART (t
));
929 if (FLOAT_TYPE_P (type
) && !flag_unsafe_math_optimizations
)
931 /* -(A + B) -> (-B) - A. */
932 if (negate_expr_p (TREE_OPERAND (t
, 1))
933 && reorder_operands_p (TREE_OPERAND (t
, 0),
934 TREE_OPERAND (t
, 1)))
936 /* -(A + B) -> (-A) - B. */
937 return negate_expr_p (TREE_OPERAND (t
, 0));
940 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
941 return (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
942 && reorder_operands_p (TREE_OPERAND (t
, 0),
943 TREE_OPERAND (t
, 1));
946 if (TYPE_UNSIGNED (TREE_TYPE (t
)))
952 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t
))))
953 return negate_expr_p (TREE_OPERAND (t
, 1))
954 || negate_expr_p (TREE_OPERAND (t
, 0));
958 /* Negate -((double)float) as (double)(-float). */
959 if (TREE_CODE (type
) == REAL_TYPE
)
961 tree tem
= strip_float_extensions (t
);
963 return negate_expr_p (tem
);
968 /* Negate -f(x) as f(-x). */
969 if (negate_mathfn_p (builtin_mathfn_code (t
)))
970 return negate_expr_p (TREE_VALUE (TREE_OPERAND (t
, 1)));
974 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
975 if (TREE_CODE (TREE_OPERAND (t
, 1)) == INTEGER_CST
)
977 tree op1
= TREE_OPERAND (t
, 1);
978 if (TREE_INT_CST_HIGH (op1
) == 0
979 && (unsigned HOST_WIDE_INT
) (TYPE_PRECISION (type
) - 1)
980 == TREE_INT_CST_LOW (op1
))
991 /* Given T, an expression, return the negation of T. Allow for T to be
992 null, in which case return null. */
1003 type
= TREE_TYPE (t
);
1004 STRIP_SIGN_NOPS (t
);
1006 switch (TREE_CODE (t
))
1009 tem
= fold_negate_const (t
, type
);
1010 if (! TREE_OVERFLOW (tem
)
1011 || TYPE_UNSIGNED (type
)
1017 tem
= fold_negate_const (t
, type
);
1018 /* Two's complement FP formats, such as c4x, may overflow. */
1019 if (! TREE_OVERFLOW (tem
) || ! flag_trapping_math
)
1020 return fold_convert (type
, tem
);
1025 tree rpart
= negate_expr (TREE_REALPART (t
));
1026 tree ipart
= negate_expr (TREE_IMAGPART (t
));
1028 if ((TREE_CODE (rpart
) == REAL_CST
1029 && TREE_CODE (ipart
) == REAL_CST
)
1030 || (TREE_CODE (rpart
) == INTEGER_CST
1031 && TREE_CODE (ipart
) == INTEGER_CST
))
1032 return build_complex (type
, rpart
, ipart
);
1037 return fold_convert (type
, TREE_OPERAND (t
, 0));
1040 if (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
1042 /* -(A + B) -> (-B) - A. */
1043 if (negate_expr_p (TREE_OPERAND (t
, 1))
1044 && reorder_operands_p (TREE_OPERAND (t
, 0),
1045 TREE_OPERAND (t
, 1)))
1047 tem
= negate_expr (TREE_OPERAND (t
, 1));
1048 tem
= fold (build2 (MINUS_EXPR
, TREE_TYPE (t
),
1049 tem
, TREE_OPERAND (t
, 0)));
1050 return fold_convert (type
, tem
);
1053 /* -(A + B) -> (-A) - B. */
1054 if (negate_expr_p (TREE_OPERAND (t
, 0)))
1056 tem
= negate_expr (TREE_OPERAND (t
, 0));
1057 tem
= fold (build2 (MINUS_EXPR
, TREE_TYPE (t
),
1058 tem
, TREE_OPERAND (t
, 1)));
1059 return fold_convert (type
, tem
);
1065 /* - (A - B) -> B - A */
1066 if ((! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
1067 && reorder_operands_p (TREE_OPERAND (t
, 0), TREE_OPERAND (t
, 1)))
1068 return fold_convert (type
,
1069 fold (build2 (MINUS_EXPR
, TREE_TYPE (t
),
1070 TREE_OPERAND (t
, 1),
1071 TREE_OPERAND (t
, 0))));
1075 if (TYPE_UNSIGNED (TREE_TYPE (t
)))
1081 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t
))))
1083 tem
= TREE_OPERAND (t
, 1);
1084 if (negate_expr_p (tem
))
1085 return fold_convert (type
,
1086 fold (build2 (TREE_CODE (t
), TREE_TYPE (t
),
1087 TREE_OPERAND (t
, 0),
1088 negate_expr (tem
))));
1089 tem
= TREE_OPERAND (t
, 0);
1090 if (negate_expr_p (tem
))
1091 return fold_convert (type
,
1092 fold (build2 (TREE_CODE (t
), TREE_TYPE (t
),
1094 TREE_OPERAND (t
, 1))));
1099 /* Convert -((double)float) into (double)(-float). */
1100 if (TREE_CODE (type
) == REAL_TYPE
)
1102 tem
= strip_float_extensions (t
);
1103 if (tem
!= t
&& negate_expr_p (tem
))
1104 return fold_convert (type
, negate_expr (tem
));
1109 /* Negate -f(x) as f(-x). */
1110 if (negate_mathfn_p (builtin_mathfn_code (t
))
1111 && negate_expr_p (TREE_VALUE (TREE_OPERAND (t
, 1))))
1113 tree fndecl
, arg
, arglist
;
1115 fndecl
= get_callee_fndecl (t
);
1116 arg
= negate_expr (TREE_VALUE (TREE_OPERAND (t
, 1)));
1117 arglist
= build_tree_list (NULL_TREE
, arg
);
1118 return build_function_call_expr (fndecl
, arglist
);
1123 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1124 if (TREE_CODE (TREE_OPERAND (t
, 1)) == INTEGER_CST
)
1126 tree op1
= TREE_OPERAND (t
, 1);
1127 if (TREE_INT_CST_HIGH (op1
) == 0
1128 && (unsigned HOST_WIDE_INT
) (TYPE_PRECISION (type
) - 1)
1129 == TREE_INT_CST_LOW (op1
))
1131 tree ntype
= TYPE_UNSIGNED (type
)
1132 ? lang_hooks
.types
.signed_type (type
)
1133 : lang_hooks
.types
.unsigned_type (type
);
1134 tree temp
= fold_convert (ntype
, TREE_OPERAND (t
, 0));
1135 temp
= fold (build2 (RSHIFT_EXPR
, ntype
, temp
, op1
));
1136 return fold_convert (type
, temp
);
1145 tem
= fold (build1 (NEGATE_EXPR
, TREE_TYPE (t
), t
));
1146 return fold_convert (type
, tem
);
1149 /* Split a tree IN into a constant, literal and variable parts that could be
1150 combined with CODE to make IN. "constant" means an expression with
1151 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1152 commutative arithmetic operation. Store the constant part into *CONP,
1153 the literal in *LITP and return the variable part. If a part isn't
1154 present, set it to null. If the tree does not decompose in this way,
1155 return the entire tree as the variable part and the other parts as null.
1157 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1158 case, we negate an operand that was subtracted. Except if it is a
1159 literal for which we use *MINUS_LITP instead.
1161 If NEGATE_P is true, we are negating all of IN, again except a literal
1162 for which we use *MINUS_LITP instead.
1164 If IN is itself a literal or constant, return it as appropriate.
1166 Note that we do not guarantee that any of the three values will be the
1167 same type as IN, but they will have the same signedness and mode. */
1170 split_tree (tree in
, enum tree_code code
, tree
*conp
, tree
*litp
,
1171 tree
*minus_litp
, int negate_p
)
1179 /* Strip any conversions that don't change the machine mode or signedness. */
1180 STRIP_SIGN_NOPS (in
);
1182 if (TREE_CODE (in
) == INTEGER_CST
|| TREE_CODE (in
) == REAL_CST
)
1184 else if (TREE_CODE (in
) == code
1185 || (! FLOAT_TYPE_P (TREE_TYPE (in
))
1186 /* We can associate addition and subtraction together (even
1187 though the C standard doesn't say so) for integers because
1188 the value is not affected. For reals, the value might be
1189 affected, so we can't. */
1190 && ((code
== PLUS_EXPR
&& TREE_CODE (in
) == MINUS_EXPR
)
1191 || (code
== MINUS_EXPR
&& TREE_CODE (in
) == PLUS_EXPR
))))
1193 tree op0
= TREE_OPERAND (in
, 0);
1194 tree op1
= TREE_OPERAND (in
, 1);
1195 int neg1_p
= TREE_CODE (in
) == MINUS_EXPR
;
1196 int neg_litp_p
= 0, neg_conp_p
= 0, neg_var_p
= 0;
1198 /* First see if either of the operands is a literal, then a constant. */
1199 if (TREE_CODE (op0
) == INTEGER_CST
|| TREE_CODE (op0
) == REAL_CST
)
1200 *litp
= op0
, op0
= 0;
1201 else if (TREE_CODE (op1
) == INTEGER_CST
|| TREE_CODE (op1
) == REAL_CST
)
1202 *litp
= op1
, neg_litp_p
= neg1_p
, op1
= 0;
1204 if (op0
!= 0 && TREE_CONSTANT (op0
))
1205 *conp
= op0
, op0
= 0;
1206 else if (op1
!= 0 && TREE_CONSTANT (op1
))
1207 *conp
= op1
, neg_conp_p
= neg1_p
, op1
= 0;
1209 /* If we haven't dealt with either operand, this is not a case we can
1210 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1211 if (op0
!= 0 && op1
!= 0)
1216 var
= op1
, neg_var_p
= neg1_p
;
1218 /* Now do any needed negations. */
1220 *minus_litp
= *litp
, *litp
= 0;
1222 *conp
= negate_expr (*conp
);
1224 var
= negate_expr (var
);
1226 else if (TREE_CONSTANT (in
))
1234 *minus_litp
= *litp
, *litp
= 0;
1235 else if (*minus_litp
)
1236 *litp
= *minus_litp
, *minus_litp
= 0;
1237 *conp
= negate_expr (*conp
);
1238 var
= negate_expr (var
);
1244 /* Re-associate trees split by the above function. T1 and T2 are either
1245 expressions to associate or null. Return the new expression, if any. If
1246 we build an operation, do it in TYPE and with CODE. */
1249 associate_trees (tree t1
, tree t2
, enum tree_code code
, tree type
)
1256 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1257 try to fold this since we will have infinite recursion. But do
1258 deal with any NEGATE_EXPRs. */
1259 if (TREE_CODE (t1
) == code
|| TREE_CODE (t2
) == code
1260 || TREE_CODE (t1
) == MINUS_EXPR
|| TREE_CODE (t2
) == MINUS_EXPR
)
1262 if (code
== PLUS_EXPR
)
1264 if (TREE_CODE (t1
) == NEGATE_EXPR
)
1265 return build2 (MINUS_EXPR
, type
, fold_convert (type
, t2
),
1266 fold_convert (type
, TREE_OPERAND (t1
, 0)));
1267 else if (TREE_CODE (t2
) == NEGATE_EXPR
)
1268 return build2 (MINUS_EXPR
, type
, fold_convert (type
, t1
),
1269 fold_convert (type
, TREE_OPERAND (t2
, 0)));
1270 else if (integer_zerop (t2
))
1271 return fold_convert (type
, t1
);
1273 else if (code
== MINUS_EXPR
)
1275 if (integer_zerop (t2
))
1276 return fold_convert (type
, t1
);
1279 return build2 (code
, type
, fold_convert (type
, t1
),
1280 fold_convert (type
, t2
));
1283 return fold (build2 (code
, type
, fold_convert (type
, t1
),
1284 fold_convert (type
, t2
)));
1287 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1288 to produce a new constant.
1290 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1293 int_const_binop (enum tree_code code
, tree arg1
, tree arg2
, int notrunc
)
1295 unsigned HOST_WIDE_INT int1l
, int2l
;
1296 HOST_WIDE_INT int1h
, int2h
;
1297 unsigned HOST_WIDE_INT low
;
1299 unsigned HOST_WIDE_INT garbagel
;
1300 HOST_WIDE_INT garbageh
;
1302 tree type
= TREE_TYPE (arg1
);
1303 int uns
= TYPE_UNSIGNED (type
);
1305 = (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
));
1307 int no_overflow
= 0;
1309 int1l
= TREE_INT_CST_LOW (arg1
);
1310 int1h
= TREE_INT_CST_HIGH (arg1
);
1311 int2l
= TREE_INT_CST_LOW (arg2
);
1312 int2h
= TREE_INT_CST_HIGH (arg2
);
1317 low
= int1l
| int2l
, hi
= int1h
| int2h
;
1321 low
= int1l
^ int2l
, hi
= int1h
^ int2h
;
1325 low
= int1l
& int2l
, hi
= int1h
& int2h
;
1331 /* It's unclear from the C standard whether shifts can overflow.
1332 The following code ignores overflow; perhaps a C standard
1333 interpretation ruling is needed. */
1334 lshift_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1342 lrotate_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1347 overflow
= add_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1351 neg_double (int2l
, int2h
, &low
, &hi
);
1352 add_double (int1l
, int1h
, low
, hi
, &low
, &hi
);
1353 overflow
= OVERFLOW_SUM_SIGN (hi
, int2h
, int1h
);
1357 overflow
= mul_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1360 case TRUNC_DIV_EXPR
:
1361 case FLOOR_DIV_EXPR
: case CEIL_DIV_EXPR
:
1362 case EXACT_DIV_EXPR
:
1363 /* This is a shortcut for a common special case. */
1364 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1365 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1366 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1367 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1369 if (code
== CEIL_DIV_EXPR
)
1372 low
= int1l
/ int2l
, hi
= 0;
1376 /* ... fall through ... */
1378 case ROUND_DIV_EXPR
:
1379 if (int2h
== 0 && int2l
== 1)
1381 low
= int1l
, hi
= int1h
;
1384 if (int1l
== int2l
&& int1h
== int2h
1385 && ! (int1l
== 0 && int1h
== 0))
1390 overflow
= div_and_round_double (code
, uns
, int1l
, int1h
, int2l
, int2h
,
1391 &low
, &hi
, &garbagel
, &garbageh
);
1394 case TRUNC_MOD_EXPR
:
1395 case FLOOR_MOD_EXPR
: case CEIL_MOD_EXPR
:
1396 /* This is a shortcut for a common special case. */
1397 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1398 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1399 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1400 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1402 if (code
== CEIL_MOD_EXPR
)
1404 low
= int1l
% int2l
, hi
= 0;
1408 /* ... fall through ... */
1410 case ROUND_MOD_EXPR
:
1411 overflow
= div_and_round_double (code
, uns
,
1412 int1l
, int1h
, int2l
, int2h
,
1413 &garbagel
, &garbageh
, &low
, &hi
);
1419 low
= (((unsigned HOST_WIDE_INT
) int1h
1420 < (unsigned HOST_WIDE_INT
) int2h
)
1421 || (((unsigned HOST_WIDE_INT
) int1h
1422 == (unsigned HOST_WIDE_INT
) int2h
)
1425 low
= (int1h
< int2h
1426 || (int1h
== int2h
&& int1l
< int2l
));
1428 if (low
== (code
== MIN_EXPR
))
1429 low
= int1l
, hi
= int1h
;
1431 low
= int2l
, hi
= int2h
;
1438 t
= build_int_cst_wide (TREE_TYPE (arg1
), low
, hi
);
1442 /* Propagate overflow flags ourselves. */
1443 if (((!uns
|| is_sizetype
) && overflow
)
1444 | TREE_OVERFLOW (arg1
) | TREE_OVERFLOW (arg2
))
1447 TREE_OVERFLOW (t
) = 1;
1448 TREE_CONSTANT_OVERFLOW (t
) = 1;
1450 else if (TREE_CONSTANT_OVERFLOW (arg1
) | TREE_CONSTANT_OVERFLOW (arg2
))
1453 TREE_CONSTANT_OVERFLOW (t
) = 1;
1457 t
= force_fit_type (t
, 1,
1458 ((!uns
|| is_sizetype
) && overflow
)
1459 | TREE_OVERFLOW (arg1
) | TREE_OVERFLOW (arg2
),
1460 TREE_CONSTANT_OVERFLOW (arg1
)
1461 | TREE_CONSTANT_OVERFLOW (arg2
));
1466 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1467 constant. We assume ARG1 and ARG2 have the same data type, or at least
1468 are the same kind of constant and the same machine mode.
1470 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1473 const_binop (enum tree_code code
, tree arg1
, tree arg2
, int notrunc
)
1478 if (TREE_CODE (arg1
) == INTEGER_CST
)
1479 return int_const_binop (code
, arg1
, arg2
, notrunc
);
1481 if (TREE_CODE (arg1
) == REAL_CST
)
1483 enum machine_mode mode
;
1486 REAL_VALUE_TYPE value
;
1489 d1
= TREE_REAL_CST (arg1
);
1490 d2
= TREE_REAL_CST (arg2
);
1492 type
= TREE_TYPE (arg1
);
1493 mode
= TYPE_MODE (type
);
1495 /* Don't perform operation if we honor signaling NaNs and
1496 either operand is a NaN. */
1497 if (HONOR_SNANS (mode
)
1498 && (REAL_VALUE_ISNAN (d1
) || REAL_VALUE_ISNAN (d2
)))
1501 /* Don't perform operation if it would raise a division
1502 by zero exception. */
1503 if (code
== RDIV_EXPR
1504 && REAL_VALUES_EQUAL (d2
, dconst0
)
1505 && (flag_trapping_math
|| ! MODE_HAS_INFINITIES (mode
)))
1508 /* If either operand is a NaN, just return it. Otherwise, set up
1509 for floating-point trap; we return an overflow. */
1510 if (REAL_VALUE_ISNAN (d1
))
1512 else if (REAL_VALUE_ISNAN (d2
))
1515 REAL_ARITHMETIC (value
, code
, d1
, d2
);
1517 t
= build_real (type
, real_value_truncate (mode
, value
));
1519 TREE_OVERFLOW (t
) = TREE_OVERFLOW (arg1
) | TREE_OVERFLOW (arg2
);
1520 TREE_CONSTANT_OVERFLOW (t
)
1522 | TREE_CONSTANT_OVERFLOW (arg1
)
1523 | TREE_CONSTANT_OVERFLOW (arg2
);
1526 if (TREE_CODE (arg1
) == COMPLEX_CST
)
1528 tree type
= TREE_TYPE (arg1
);
1529 tree r1
= TREE_REALPART (arg1
);
1530 tree i1
= TREE_IMAGPART (arg1
);
1531 tree r2
= TREE_REALPART (arg2
);
1532 tree i2
= TREE_IMAGPART (arg2
);
1538 t
= build_complex (type
,
1539 const_binop (PLUS_EXPR
, r1
, r2
, notrunc
),
1540 const_binop (PLUS_EXPR
, i1
, i2
, notrunc
));
1544 t
= build_complex (type
,
1545 const_binop (MINUS_EXPR
, r1
, r2
, notrunc
),
1546 const_binop (MINUS_EXPR
, i1
, i2
, notrunc
));
1550 t
= build_complex (type
,
1551 const_binop (MINUS_EXPR
,
1552 const_binop (MULT_EXPR
,
1554 const_binop (MULT_EXPR
,
1557 const_binop (PLUS_EXPR
,
1558 const_binop (MULT_EXPR
,
1560 const_binop (MULT_EXPR
,
1568 = const_binop (PLUS_EXPR
,
1569 const_binop (MULT_EXPR
, r2
, r2
, notrunc
),
1570 const_binop (MULT_EXPR
, i2
, i2
, notrunc
),
1573 t
= build_complex (type
,
1575 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1576 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1577 const_binop (PLUS_EXPR
,
1578 const_binop (MULT_EXPR
, r1
, r2
,
1580 const_binop (MULT_EXPR
, i1
, i2
,
1583 magsquared
, notrunc
),
1585 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1586 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1587 const_binop (MINUS_EXPR
,
1588 const_binop (MULT_EXPR
, i1
, r2
,
1590 const_binop (MULT_EXPR
, r1
, i2
,
1593 magsquared
, notrunc
));
1605 /* Create a size type INT_CST node with NUMBER sign extended. KIND
1606 indicates which particular sizetype to create. */
1609 size_int_kind (HOST_WIDE_INT number
, enum size_type_kind kind
)
1611 return build_int_cst (sizetype_tab
[(int) kind
], number
);
1614 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1615 is a tree code. The type of the result is taken from the operands.
1616 Both must be the same type integer type and it must be a size type.
1617 If the operands are constant, so is the result. */
1620 size_binop (enum tree_code code
, tree arg0
, tree arg1
)
1622 tree type
= TREE_TYPE (arg0
);
1624 gcc_assert (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
)
1625 && type
== TREE_TYPE (arg1
));
1627 /* Handle the special case of two integer constants faster. */
1628 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
1630 /* And some specific cases even faster than that. */
1631 if (code
== PLUS_EXPR
&& integer_zerop (arg0
))
1633 else if ((code
== MINUS_EXPR
|| code
== PLUS_EXPR
)
1634 && integer_zerop (arg1
))
1636 else if (code
== MULT_EXPR
&& integer_onep (arg0
))
1639 /* Handle general case of two integer constants. */
1640 return int_const_binop (code
, arg0
, arg1
, 0);
1643 if (arg0
== error_mark_node
|| arg1
== error_mark_node
)
1644 return error_mark_node
;
1646 return fold (build2 (code
, type
, arg0
, arg1
));
1649 /* Given two values, either both of sizetype or both of bitsizetype,
1650 compute the difference between the two values. Return the value
1651 in signed type corresponding to the type of the operands. */
1654 size_diffop (tree arg0
, tree arg1
)
1656 tree type
= TREE_TYPE (arg0
);
1659 gcc_assert (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
)
1660 && type
== TREE_TYPE (arg1
));
1662 /* If the type is already signed, just do the simple thing. */
1663 if (!TYPE_UNSIGNED (type
))
1664 return size_binop (MINUS_EXPR
, arg0
, arg1
);
1666 ctype
= type
== bitsizetype
? sbitsizetype
: ssizetype
;
1668 /* If either operand is not a constant, do the conversions to the signed
1669 type and subtract. The hardware will do the right thing with any
1670 overflow in the subtraction. */
1671 if (TREE_CODE (arg0
) != INTEGER_CST
|| TREE_CODE (arg1
) != INTEGER_CST
)
1672 return size_binop (MINUS_EXPR
, fold_convert (ctype
, arg0
),
1673 fold_convert (ctype
, arg1
));
1675 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1676 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1677 overflow) and negate (which can't either). Special-case a result
1678 of zero while we're here. */
1679 if (tree_int_cst_equal (arg0
, arg1
))
1680 return fold_convert (ctype
, integer_zero_node
);
1681 else if (tree_int_cst_lt (arg1
, arg0
))
1682 return fold_convert (ctype
, size_binop (MINUS_EXPR
, arg0
, arg1
));
1684 return size_binop (MINUS_EXPR
, fold_convert (ctype
, integer_zero_node
),
1685 fold_convert (ctype
, size_binop (MINUS_EXPR
,
1689 /* Construct a vector of zero elements of vector type TYPE. */
1692 build_zero_vector (tree type
)
1697 elem
= fold_convert_const (NOP_EXPR
, TREE_TYPE (type
), integer_zero_node
);
1698 units
= TYPE_VECTOR_SUBPARTS (type
);
1701 for (i
= 0; i
< units
; i
++)
1702 list
= tree_cons (NULL_TREE
, elem
, list
);
1703 return build_vector (type
, list
);
1707 /* Attempt to fold type conversion operation CODE of expression ARG1 to
1708 type TYPE. If no simplification can be done return NULL_TREE. */
1711 fold_convert_const (enum tree_code code
, tree type
, tree arg1
)
1716 if (TREE_TYPE (arg1
) == type
)
1719 if (POINTER_TYPE_P (type
) || INTEGRAL_TYPE_P (type
))
1721 if (TREE_CODE (arg1
) == INTEGER_CST
)
1723 /* If we would build a constant wider than GCC supports,
1724 leave the conversion unfolded. */
1725 if (TYPE_PRECISION (type
) > 2 * HOST_BITS_PER_WIDE_INT
)
1728 /* Given an integer constant, make new constant with new type,
1729 appropriately sign-extended or truncated. */
1730 t
= build_int_cst_wide (type
, TREE_INT_CST_LOW (arg1
),
1731 TREE_INT_CST_HIGH (arg1
));
1733 t
= force_fit_type (t
,
1734 /* Don't set the overflow when
1735 converting a pointer */
1736 !POINTER_TYPE_P (TREE_TYPE (arg1
)),
1737 (TREE_INT_CST_HIGH (arg1
) < 0
1738 && (TYPE_UNSIGNED (type
)
1739 < TYPE_UNSIGNED (TREE_TYPE (arg1
))))
1740 | TREE_OVERFLOW (arg1
),
1741 TREE_CONSTANT_OVERFLOW (arg1
));
1744 else if (TREE_CODE (arg1
) == REAL_CST
)
1746 /* The following code implements the floating point to integer
1747 conversion rules required by the Java Language Specification,
1748 that IEEE NaNs are mapped to zero and values that overflow
1749 the target precision saturate, i.e. values greater than
1750 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1751 are mapped to INT_MIN. These semantics are allowed by the
1752 C and C++ standards that simply state that the behavior of
1753 FP-to-integer conversion is unspecified upon overflow. */
1755 HOST_WIDE_INT high
, low
;
1757 REAL_VALUE_TYPE x
= TREE_REAL_CST (arg1
);
1761 case FIX_TRUNC_EXPR
:
1762 real_trunc (&r
, VOIDmode
, &x
);
1766 real_ceil (&r
, VOIDmode
, &x
);
1769 case FIX_FLOOR_EXPR
:
1770 real_floor (&r
, VOIDmode
, &x
);
1773 case FIX_ROUND_EXPR
:
1774 real_round (&r
, VOIDmode
, &x
);
1781 /* If R is NaN, return zero and show we have an overflow. */
1782 if (REAL_VALUE_ISNAN (r
))
1789 /* See if R is less than the lower bound or greater than the
1794 tree lt
= TYPE_MIN_VALUE (type
);
1795 REAL_VALUE_TYPE l
= real_value_from_int_cst (NULL_TREE
, lt
);
1796 if (REAL_VALUES_LESS (r
, l
))
1799 high
= TREE_INT_CST_HIGH (lt
);
1800 low
= TREE_INT_CST_LOW (lt
);
1806 tree ut
= TYPE_MAX_VALUE (type
);
1809 REAL_VALUE_TYPE u
= real_value_from_int_cst (NULL_TREE
, ut
);
1810 if (REAL_VALUES_LESS (u
, r
))
1813 high
= TREE_INT_CST_HIGH (ut
);
1814 low
= TREE_INT_CST_LOW (ut
);
1820 REAL_VALUE_TO_INT (&low
, &high
, r
);
1822 t
= build_int_cst_wide (type
, low
, high
);
1824 t
= force_fit_type (t
, -1, overflow
| TREE_OVERFLOW (arg1
),
1825 TREE_CONSTANT_OVERFLOW (arg1
));
1829 else if (TREE_CODE (type
) == REAL_TYPE
)
1831 if (TREE_CODE (arg1
) == INTEGER_CST
)
1832 return build_real_from_int_cst (type
, arg1
);
1833 if (TREE_CODE (arg1
) == REAL_CST
)
1835 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
1837 /* We make a copy of ARG1 so that we don't modify an
1838 existing constant tree. */
1839 t
= copy_node (arg1
);
1840 TREE_TYPE (t
) = type
;
1844 t
= build_real (type
,
1845 real_value_truncate (TYPE_MODE (type
),
1846 TREE_REAL_CST (arg1
)));
1848 TREE_OVERFLOW (t
) = TREE_OVERFLOW (arg1
);
1849 TREE_CONSTANT_OVERFLOW (t
)
1850 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1857 /* Convert expression ARG to type TYPE. Used by the middle-end for
1858 simple conversions in preference to calling the front-end's convert. */
1861 fold_convert (tree type
, tree arg
)
1863 tree orig
= TREE_TYPE (arg
);
1869 if (TREE_CODE (arg
) == ERROR_MARK
1870 || TREE_CODE (type
) == ERROR_MARK
1871 || TREE_CODE (orig
) == ERROR_MARK
)
1872 return error_mark_node
;
1874 if (TYPE_MAIN_VARIANT (type
) == TYPE_MAIN_VARIANT (orig
)
1875 || lang_hooks
.types_compatible_p (TYPE_MAIN_VARIANT (type
),
1876 TYPE_MAIN_VARIANT (orig
)))
1877 return fold (build1 (NOP_EXPR
, type
, arg
));
1879 switch (TREE_CODE (type
))
1881 case INTEGER_TYPE
: case CHAR_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
1882 case POINTER_TYPE
: case REFERENCE_TYPE
:
1884 if (TREE_CODE (arg
) == INTEGER_CST
)
1886 tem
= fold_convert_const (NOP_EXPR
, type
, arg
);
1887 if (tem
!= NULL_TREE
)
1890 if (INTEGRAL_TYPE_P (orig
) || POINTER_TYPE_P (orig
)
1891 || TREE_CODE (orig
) == OFFSET_TYPE
)
1892 return fold (build1 (NOP_EXPR
, type
, arg
));
1893 if (TREE_CODE (orig
) == COMPLEX_TYPE
)
1895 tem
= fold (build1 (REALPART_EXPR
, TREE_TYPE (orig
), arg
));
1896 return fold_convert (type
, tem
);
1898 gcc_assert (TREE_CODE (orig
) == VECTOR_TYPE
1899 && tree_int_cst_equal (TYPE_SIZE (type
), TYPE_SIZE (orig
)));
1900 return fold (build1 (NOP_EXPR
, type
, arg
));
1903 if (TREE_CODE (arg
) == INTEGER_CST
)
1905 tem
= fold_convert_const (FLOAT_EXPR
, type
, arg
);
1906 if (tem
!= NULL_TREE
)
1909 else if (TREE_CODE (arg
) == REAL_CST
)
1911 tem
= fold_convert_const (NOP_EXPR
, type
, arg
);
1912 if (tem
!= NULL_TREE
)
1916 switch (TREE_CODE (orig
))
1918 case INTEGER_TYPE
: case CHAR_TYPE
:
1919 case BOOLEAN_TYPE
: case ENUMERAL_TYPE
:
1920 case POINTER_TYPE
: case REFERENCE_TYPE
:
1921 return fold (build1 (FLOAT_EXPR
, type
, arg
));
1924 return fold (build1 (flag_float_store
? CONVERT_EXPR
: NOP_EXPR
,
1928 tem
= fold (build1 (REALPART_EXPR
, TREE_TYPE (orig
), arg
));
1929 return fold_convert (type
, tem
);
1936 switch (TREE_CODE (orig
))
1938 case INTEGER_TYPE
: case CHAR_TYPE
:
1939 case BOOLEAN_TYPE
: case ENUMERAL_TYPE
:
1940 case POINTER_TYPE
: case REFERENCE_TYPE
:
1942 return build2 (COMPLEX_EXPR
, type
,
1943 fold_convert (TREE_TYPE (type
), arg
),
1944 fold_convert (TREE_TYPE (type
), integer_zero_node
));
1949 if (TREE_CODE (arg
) == COMPLEX_EXPR
)
1951 rpart
= fold_convert (TREE_TYPE (type
), TREE_OPERAND (arg
, 0));
1952 ipart
= fold_convert (TREE_TYPE (type
), TREE_OPERAND (arg
, 1));
1953 return fold (build2 (COMPLEX_EXPR
, type
, rpart
, ipart
));
1956 arg
= save_expr (arg
);
1957 rpart
= fold (build1 (REALPART_EXPR
, TREE_TYPE (orig
), arg
));
1958 ipart
= fold (build1 (IMAGPART_EXPR
, TREE_TYPE (orig
), arg
));
1959 rpart
= fold_convert (TREE_TYPE (type
), rpart
);
1960 ipart
= fold_convert (TREE_TYPE (type
), ipart
);
1961 return fold (build2 (COMPLEX_EXPR
, type
, rpart
, ipart
));
1969 if (integer_zerop (arg
))
1970 return build_zero_vector (type
);
1971 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type
), TYPE_SIZE (orig
)));
1972 gcc_assert (INTEGRAL_TYPE_P (orig
) || POINTER_TYPE_P (orig
)
1973 || TREE_CODE (orig
) == VECTOR_TYPE
);
1974 return fold (build1 (NOP_EXPR
, type
, arg
));
1977 return fold (build1 (CONVERT_EXPR
, type
, fold_ignored_result (arg
)));
1984 /* Return an expr equal to X but certainly not valid as an lvalue. */
1989 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
1994 /* We only need to wrap lvalue tree codes. */
1995 switch (TREE_CODE (x
))
2006 case ALIGN_INDIRECT_REF
:
2007 case MISALIGNED_INDIRECT_REF
:
2009 case ARRAY_RANGE_REF
:
2015 case PREINCREMENT_EXPR
:
2016 case PREDECREMENT_EXPR
:
2018 case TRY_CATCH_EXPR
:
2019 case WITH_CLEANUP_EXPR
:
2030 /* Assume the worst for front-end tree codes. */
2031 if ((int)TREE_CODE (x
) >= NUM_TREE_CODES
)
2035 return build1 (NON_LVALUE_EXPR
, TREE_TYPE (x
), x
);
2038 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2039 Zero means allow extended lvalues. */
2041 int pedantic_lvalues
;
2043 /* When pedantic, return an expr equal to X but certainly not valid as a
2044 pedantic lvalue. Otherwise, return X. */
2047 pedantic_non_lvalue (tree x
)
2049 if (pedantic_lvalues
)
2050 return non_lvalue (x
);
2055 /* Given a tree comparison code, return the code that is the logical inverse
2056 of the given code. It is not safe to do this for floating-point
2057 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2058 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2060 static enum tree_code
2061 invert_tree_comparison (enum tree_code code
, bool honor_nans
)
2063 if (honor_nans
&& flag_trapping_math
)
2073 return honor_nans
? UNLE_EXPR
: LE_EXPR
;
2075 return honor_nans
? UNLT_EXPR
: LT_EXPR
;
2077 return honor_nans
? UNGE_EXPR
: GE_EXPR
;
2079 return honor_nans
? UNGT_EXPR
: GT_EXPR
;
2093 return UNORDERED_EXPR
;
2094 case UNORDERED_EXPR
:
2095 return ORDERED_EXPR
;
2101 /* Similar, but return the comparison that results if the operands are
2102 swapped. This is safe for floating-point. */
2105 swap_tree_comparison (enum tree_code code
)
2126 /* Convert a comparison tree code from an enum tree_code representation
2127 into a compcode bit-based encoding. This function is the inverse of
2128 compcode_to_comparison. */
2130 static enum comparison_code
2131 comparison_to_compcode (enum tree_code code
)
2148 return COMPCODE_ORD
;
2149 case UNORDERED_EXPR
:
2150 return COMPCODE_UNORD
;
2152 return COMPCODE_UNLT
;
2154 return COMPCODE_UNEQ
;
2156 return COMPCODE_UNLE
;
2158 return COMPCODE_UNGT
;
2160 return COMPCODE_LTGT
;
2162 return COMPCODE_UNGE
;
2168 /* Convert a compcode bit-based encoding of a comparison operator back
2169 to GCC's enum tree_code representation. This function is the
2170 inverse of comparison_to_compcode. */
2172 static enum tree_code
2173 compcode_to_comparison (enum comparison_code code
)
2190 return ORDERED_EXPR
;
2191 case COMPCODE_UNORD
:
2192 return UNORDERED_EXPR
;
2210 /* Return a tree for the comparison which is the combination of
2211 doing the AND or OR (depending on CODE) of the two operations LCODE
2212 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2213 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2214 if this makes the transformation invalid. */
2217 combine_comparisons (enum tree_code code
, enum tree_code lcode
,
2218 enum tree_code rcode
, tree truth_type
,
2219 tree ll_arg
, tree lr_arg
)
2221 bool honor_nans
= HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg
)));
2222 enum comparison_code lcompcode
= comparison_to_compcode (lcode
);
2223 enum comparison_code rcompcode
= comparison_to_compcode (rcode
);
2224 enum comparison_code compcode
;
2228 case TRUTH_AND_EXPR
: case TRUTH_ANDIF_EXPR
:
2229 compcode
= lcompcode
& rcompcode
;
2232 case TRUTH_OR_EXPR
: case TRUTH_ORIF_EXPR
:
2233 compcode
= lcompcode
| rcompcode
;
2242 /* Eliminate unordered comparisons, as well as LTGT and ORD
2243 which are not used unless the mode has NaNs. */
2244 compcode
&= ~COMPCODE_UNORD
;
2245 if (compcode
== COMPCODE_LTGT
)
2246 compcode
= COMPCODE_NE
;
2247 else if (compcode
== COMPCODE_ORD
)
2248 compcode
= COMPCODE_TRUE
;
2250 else if (flag_trapping_math
)
2252 /* Check that the original operation and the optimized ones will trap
2253 under the same condition. */
2254 bool ltrap
= (lcompcode
& COMPCODE_UNORD
) == 0
2255 && (lcompcode
!= COMPCODE_EQ
)
2256 && (lcompcode
!= COMPCODE_ORD
);
2257 bool rtrap
= (rcompcode
& COMPCODE_UNORD
) == 0
2258 && (rcompcode
!= COMPCODE_EQ
)
2259 && (rcompcode
!= COMPCODE_ORD
);
2260 bool trap
= (compcode
& COMPCODE_UNORD
) == 0
2261 && (compcode
!= COMPCODE_EQ
)
2262 && (compcode
!= COMPCODE_ORD
);
2264 /* In a short-circuited boolean expression the LHS might be
2265 such that the RHS, if evaluated, will never trap. For
2266 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2267 if neither x nor y is NaN. (This is a mixed blessing: for
2268 example, the expression above will never trap, hence
2269 optimizing it to x < y would be invalid). */
2270 if ((code
== TRUTH_ORIF_EXPR
&& (lcompcode
& COMPCODE_UNORD
))
2271 || (code
== TRUTH_ANDIF_EXPR
&& !(lcompcode
& COMPCODE_UNORD
)))
2274 /* If the comparison was short-circuited, and only the RHS
2275 trapped, we may now generate a spurious trap. */
2277 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
))
2280 /* If we changed the conditions that cause a trap, we lose. */
2281 if ((ltrap
|| rtrap
) != trap
)
2285 if (compcode
== COMPCODE_TRUE
)
2286 return constant_boolean_node (true, truth_type
);
2287 else if (compcode
== COMPCODE_FALSE
)
2288 return constant_boolean_node (false, truth_type
);
2290 return fold (build2 (compcode_to_comparison (compcode
),
2291 truth_type
, ll_arg
, lr_arg
));
2294 /* Return nonzero if CODE is a tree code that represents a truth value. */
2297 truth_value_p (enum tree_code code
)
2299 return (TREE_CODE_CLASS (code
) == tcc_comparison
2300 || code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
2301 || code
== TRUTH_OR_EXPR
|| code
== TRUTH_ORIF_EXPR
2302 || code
== TRUTH_XOR_EXPR
|| code
== TRUTH_NOT_EXPR
);
2305 /* Return nonzero if two operands (typically of the same tree node)
2306 are necessarily equal. If either argument has side-effects this
2307 function returns zero. FLAGS modifies behavior as follows:
2309 If OEP_ONLY_CONST is set, only return nonzero for constants.
2310 This function tests whether the operands are indistinguishable;
2311 it does not test whether they are equal using C's == operation.
2312 The distinction is important for IEEE floating point, because
2313 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2314 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2316 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2317 even though it may hold multiple values during a function.
2318 This is because a GCC tree node guarantees that nothing else is
2319 executed between the evaluation of its "operands" (which may often
2320 be evaluated in arbitrary order). Hence if the operands themselves
2321 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2322 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2323 unset means assuming isochronic (or instantaneous) tree equivalence.
2324 Unless comparing arbitrary expression trees, such as from different
2325 statements, this flag can usually be left unset.
2327 If OEP_PURE_SAME is set, then pure functions with identical arguments
2328 are considered the same. It is used when the caller has other ways
2329 to ensure that global memory is unchanged in between. */
2332 operand_equal_p (tree arg0
, tree arg1
, unsigned int flags
)
2334 /* If one is specified and the other isn't, they aren't equal and if
2335 neither is specified, they are.
2337 ??? This is temporary and is meant only to handle the cases of the
2338 optional operands for COMPONENT_REF and ARRAY_REF. */
2339 if ((arg0
&& !arg1
) || (!arg0
&& arg1
))
2341 else if (!arg0
&& !arg1
)
2343 /* If either is ERROR_MARK, they aren't equal. */
2344 else if (TREE_CODE (arg0
) == ERROR_MARK
|| TREE_CODE (arg1
) == ERROR_MARK
)
2347 /* If both types don't have the same signedness, then we can't consider
2348 them equal. We must check this before the STRIP_NOPS calls
2349 because they may change the signedness of the arguments. */
2350 if (TYPE_UNSIGNED (TREE_TYPE (arg0
)) != TYPE_UNSIGNED (TREE_TYPE (arg1
)))
2356 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
2357 /* This is needed for conversions and for COMPONENT_REF.
2358 Might as well play it safe and always test this. */
2359 || TREE_CODE (TREE_TYPE (arg0
)) == ERROR_MARK
2360 || TREE_CODE (TREE_TYPE (arg1
)) == ERROR_MARK
2361 || TYPE_MODE (TREE_TYPE (arg0
)) != TYPE_MODE (TREE_TYPE (arg1
)))
2364 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2365 We don't care about side effects in that case because the SAVE_EXPR
2366 takes care of that for us. In all other cases, two expressions are
2367 equal if they have no side effects. If we have two identical
2368 expressions with side effects that should be treated the same due
2369 to the only side effects being identical SAVE_EXPR's, that will
2370 be detected in the recursive calls below. */
2371 if (arg0
== arg1
&& ! (flags
& OEP_ONLY_CONST
)
2372 && (TREE_CODE (arg0
) == SAVE_EXPR
2373 || (! TREE_SIDE_EFFECTS (arg0
) && ! TREE_SIDE_EFFECTS (arg1
))))
2376 /* Next handle constant cases, those for which we can return 1 even
2377 if ONLY_CONST is set. */
2378 if (TREE_CONSTANT (arg0
) && TREE_CONSTANT (arg1
))
2379 switch (TREE_CODE (arg0
))
2382 return (! TREE_CONSTANT_OVERFLOW (arg0
)
2383 && ! TREE_CONSTANT_OVERFLOW (arg1
)
2384 && tree_int_cst_equal (arg0
, arg1
));
2387 return (! TREE_CONSTANT_OVERFLOW (arg0
)
2388 && ! TREE_CONSTANT_OVERFLOW (arg1
)
2389 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0
),
2390 TREE_REAL_CST (arg1
)));
2396 if (TREE_CONSTANT_OVERFLOW (arg0
)
2397 || TREE_CONSTANT_OVERFLOW (arg1
))
2400 v1
= TREE_VECTOR_CST_ELTS (arg0
);
2401 v2
= TREE_VECTOR_CST_ELTS (arg1
);
2404 if (!operand_equal_p (TREE_VALUE (v1
), TREE_VALUE (v2
),
2407 v1
= TREE_CHAIN (v1
);
2408 v2
= TREE_CHAIN (v2
);
2415 return (operand_equal_p (TREE_REALPART (arg0
), TREE_REALPART (arg1
),
2417 && operand_equal_p (TREE_IMAGPART (arg0
), TREE_IMAGPART (arg1
),
2421 return (TREE_STRING_LENGTH (arg0
) == TREE_STRING_LENGTH (arg1
)
2422 && ! memcmp (TREE_STRING_POINTER (arg0
),
2423 TREE_STRING_POINTER (arg1
),
2424 TREE_STRING_LENGTH (arg0
)));
2427 return operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0),
2433 if (flags
& OEP_ONLY_CONST
)
2436 switch (TREE_CODE_CLASS (TREE_CODE (arg0
)))
2439 /* Two conversions are equal only if signedness and modes match. */
2440 switch (TREE_CODE (arg0
))
2445 case FIX_TRUNC_EXPR
:
2446 case FIX_FLOOR_EXPR
:
2447 case FIX_ROUND_EXPR
:
2448 if (TYPE_UNSIGNED (TREE_TYPE (arg0
))
2449 != TYPE_UNSIGNED (TREE_TYPE (arg1
)))
2456 return operand_equal_p (TREE_OPERAND (arg0
, 0),
2457 TREE_OPERAND (arg1
, 0), flags
);
2459 case tcc_comparison
:
2461 if (operand_equal_p (TREE_OPERAND (arg0
, 0),
2462 TREE_OPERAND (arg1
, 0), flags
)
2463 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2464 TREE_OPERAND (arg1
, 1), flags
))
2467 /* For commutative ops, allow the other order. */
2468 return (commutative_tree_code (TREE_CODE (arg0
))
2469 && operand_equal_p (TREE_OPERAND (arg0
, 0),
2470 TREE_OPERAND (arg1
, 1), flags
)
2471 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2472 TREE_OPERAND (arg1
, 0), flags
));
2475 /* If either of the pointer (or reference) expressions we are
2476 dereferencing contain a side effect, these cannot be equal. */
2477 if (TREE_SIDE_EFFECTS (arg0
)
2478 || TREE_SIDE_EFFECTS (arg1
))
2481 switch (TREE_CODE (arg0
))
2484 case ALIGN_INDIRECT_REF
:
2485 case MISALIGNED_INDIRECT_REF
:
2488 return operand_equal_p (TREE_OPERAND (arg0
, 0),
2489 TREE_OPERAND (arg1
, 0), flags
);
2492 case ARRAY_RANGE_REF
:
2493 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
2494 TREE_OPERAND (arg1
, 0), flags
)
2495 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2496 TREE_OPERAND (arg1
, 1), flags
)
2497 && operand_equal_p (TREE_OPERAND (arg0
, 2),
2498 TREE_OPERAND (arg1
, 2), flags
)
2499 && operand_equal_p (TREE_OPERAND (arg0
, 3),
2500 TREE_OPERAND (arg1
, 3), flags
));
2504 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
2505 TREE_OPERAND (arg1
, 0), flags
)
2506 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2507 TREE_OPERAND (arg1
, 1), flags
)
2508 && operand_equal_p (TREE_OPERAND (arg0
, 2),
2509 TREE_OPERAND (arg1
, 2), flags
));
2513 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
2514 TREE_OPERAND (arg1
, 0), flags
)
2515 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2516 TREE_OPERAND (arg1
, 1), flags
)
2517 && operand_equal_p (TREE_OPERAND (arg0
, 2),
2518 TREE_OPERAND (arg1
, 2), flags
));
2523 case tcc_expression
:
2524 switch (TREE_CODE (arg0
))
2527 case TRUTH_NOT_EXPR
:
2528 return operand_equal_p (TREE_OPERAND (arg0
, 0),
2529 TREE_OPERAND (arg1
, 0), flags
);
2531 case TRUTH_ANDIF_EXPR
:
2532 case TRUTH_ORIF_EXPR
:
2533 return operand_equal_p (TREE_OPERAND (arg0
, 0),
2534 TREE_OPERAND (arg1
, 0), flags
)
2535 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2536 TREE_OPERAND (arg1
, 1), flags
);
2538 case TRUTH_AND_EXPR
:
2540 case TRUTH_XOR_EXPR
:
2541 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
2542 TREE_OPERAND (arg1
, 0), flags
)
2543 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2544 TREE_OPERAND (arg1
, 1), flags
))
2545 || (operand_equal_p (TREE_OPERAND (arg0
, 0),
2546 TREE_OPERAND (arg1
, 1), flags
)
2547 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2548 TREE_OPERAND (arg1
, 0), flags
));
2551 /* If the CALL_EXPRs call different functions, then they
2552 clearly can not be equal. */
2553 if (! operand_equal_p (TREE_OPERAND (arg0
, 0),
2554 TREE_OPERAND (arg1
, 0), flags
))
2558 unsigned int cef
= call_expr_flags (arg0
);
2559 if (flags
& OEP_PURE_SAME
)
2560 cef
&= ECF_CONST
| ECF_PURE
;
2567 /* Now see if all the arguments are the same. operand_equal_p
2568 does not handle TREE_LIST, so we walk the operands here
2569 feeding them to operand_equal_p. */
2570 arg0
= TREE_OPERAND (arg0
, 1);
2571 arg1
= TREE_OPERAND (arg1
, 1);
2572 while (arg0
&& arg1
)
2574 if (! operand_equal_p (TREE_VALUE (arg0
), TREE_VALUE (arg1
),
2578 arg0
= TREE_CHAIN (arg0
);
2579 arg1
= TREE_CHAIN (arg1
);
2582 /* If we get here and both argument lists are exhausted
2583 then the CALL_EXPRs are equal. */
2584 return ! (arg0
|| arg1
);
2590 case tcc_declaration
:
2591 /* Consider __builtin_sqrt equal to sqrt. */
2592 return (TREE_CODE (arg0
) == FUNCTION_DECL
2593 && DECL_BUILT_IN (arg0
) && DECL_BUILT_IN (arg1
)
2594 && DECL_BUILT_IN_CLASS (arg0
) == DECL_BUILT_IN_CLASS (arg1
)
2595 && DECL_FUNCTION_CODE (arg0
) == DECL_FUNCTION_CODE (arg1
));
2602 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2603 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2605 When in doubt, return 0. */
2608 operand_equal_for_comparison_p (tree arg0
, tree arg1
, tree other
)
2610 int unsignedp1
, unsignedpo
;
2611 tree primarg0
, primarg1
, primother
;
2612 unsigned int correct_width
;
2614 if (operand_equal_p (arg0
, arg1
, 0))
2617 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
2618 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
2621 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2622 and see if the inner values are the same. This removes any
2623 signedness comparison, which doesn't matter here. */
2624 primarg0
= arg0
, primarg1
= arg1
;
2625 STRIP_NOPS (primarg0
);
2626 STRIP_NOPS (primarg1
);
2627 if (operand_equal_p (primarg0
, primarg1
, 0))
2630 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2631 actual comparison operand, ARG0.
2633 First throw away any conversions to wider types
2634 already present in the operands. */
2636 primarg1
= get_narrower (arg1
, &unsignedp1
);
2637 primother
= get_narrower (other
, &unsignedpo
);
2639 correct_width
= TYPE_PRECISION (TREE_TYPE (arg1
));
2640 if (unsignedp1
== unsignedpo
2641 && TYPE_PRECISION (TREE_TYPE (primarg1
)) < correct_width
2642 && TYPE_PRECISION (TREE_TYPE (primother
)) < correct_width
)
2644 tree type
= TREE_TYPE (arg0
);
2646 /* Make sure shorter operand is extended the right way
2647 to match the longer operand. */
2648 primarg1
= fold_convert (lang_hooks
.types
.signed_or_unsigned_type
2649 (unsignedp1
, TREE_TYPE (primarg1
)), primarg1
);
2651 if (operand_equal_p (arg0
, fold_convert (type
, primarg1
), 0))
2658 /* See if ARG is an expression that is either a comparison or is performing
2659 arithmetic on comparisons. The comparisons must only be comparing
2660 two different values, which will be stored in *CVAL1 and *CVAL2; if
2661 they are nonzero it means that some operands have already been found.
2662 No variables may be used anywhere else in the expression except in the
2663 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2664 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2666 If this is true, return 1. Otherwise, return zero. */
2669 twoval_comparison_p (tree arg
, tree
*cval1
, tree
*cval2
, int *save_p
)
2671 enum tree_code code
= TREE_CODE (arg
);
2672 enum tree_code_class
class = TREE_CODE_CLASS (code
);
2674 /* We can handle some of the tcc_expression cases here. */
2675 if (class == tcc_expression
&& code
== TRUTH_NOT_EXPR
)
2677 else if (class == tcc_expression
2678 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
2679 || code
== COMPOUND_EXPR
))
2682 else if (class == tcc_expression
&& code
== SAVE_EXPR
2683 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg
, 0)))
2685 /* If we've already found a CVAL1 or CVAL2, this expression is
2686 two complex to handle. */
2687 if (*cval1
|| *cval2
)
2697 return twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
);
2700 return (twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
)
2701 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2702 cval1
, cval2
, save_p
));
2707 case tcc_expression
:
2708 if (code
== COND_EXPR
)
2709 return (twoval_comparison_p (TREE_OPERAND (arg
, 0),
2710 cval1
, cval2
, save_p
)
2711 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2712 cval1
, cval2
, save_p
)
2713 && twoval_comparison_p (TREE_OPERAND (arg
, 2),
2714 cval1
, cval2
, save_p
));
2717 case tcc_comparison
:
2718 /* First see if we can handle the first operand, then the second. For
2719 the second operand, we know *CVAL1 can't be zero. It must be that
2720 one side of the comparison is each of the values; test for the
2721 case where this isn't true by failing if the two operands
2724 if (operand_equal_p (TREE_OPERAND (arg
, 0),
2725 TREE_OPERAND (arg
, 1), 0))
2729 *cval1
= TREE_OPERAND (arg
, 0);
2730 else if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 0), 0))
2732 else if (*cval2
== 0)
2733 *cval2
= TREE_OPERAND (arg
, 0);
2734 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 0), 0))
2739 if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 1), 0))
2741 else if (*cval2
== 0)
2742 *cval2
= TREE_OPERAND (arg
, 1);
2743 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 1), 0))
2755 /* ARG is a tree that is known to contain just arithmetic operations and
2756 comparisons. Evaluate the operations in the tree substituting NEW0 for
2757 any occurrence of OLD0 as an operand of a comparison and likewise for
2761 eval_subst (tree arg
, tree old0
, tree new0
, tree old1
, tree new1
)
2763 tree type
= TREE_TYPE (arg
);
2764 enum tree_code code
= TREE_CODE (arg
);
2765 enum tree_code_class
class = TREE_CODE_CLASS (code
);
2767 /* We can handle some of the tcc_expression cases here. */
2768 if (class == tcc_expression
&& code
== TRUTH_NOT_EXPR
)
2770 else if (class == tcc_expression
2771 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
))
2777 return fold (build1 (code
, type
,
2778 eval_subst (TREE_OPERAND (arg
, 0),
2779 old0
, new0
, old1
, new1
)));
2782 return fold (build2 (code
, type
,
2783 eval_subst (TREE_OPERAND (arg
, 0),
2784 old0
, new0
, old1
, new1
),
2785 eval_subst (TREE_OPERAND (arg
, 1),
2786 old0
, new0
, old1
, new1
)));
2788 case tcc_expression
:
2792 return eval_subst (TREE_OPERAND (arg
, 0), old0
, new0
, old1
, new1
);
2795 return eval_subst (TREE_OPERAND (arg
, 1), old0
, new0
, old1
, new1
);
2798 return fold (build3 (code
, type
,
2799 eval_subst (TREE_OPERAND (arg
, 0),
2800 old0
, new0
, old1
, new1
),
2801 eval_subst (TREE_OPERAND (arg
, 1),
2802 old0
, new0
, old1
, new1
),
2803 eval_subst (TREE_OPERAND (arg
, 2),
2804 old0
, new0
, old1
, new1
)));
2808 /* Fall through - ??? */
2810 case tcc_comparison
:
2812 tree arg0
= TREE_OPERAND (arg
, 0);
2813 tree arg1
= TREE_OPERAND (arg
, 1);
2815 /* We need to check both for exact equality and tree equality. The
2816 former will be true if the operand has a side-effect. In that
2817 case, we know the operand occurred exactly once. */
2819 if (arg0
== old0
|| operand_equal_p (arg0
, old0
, 0))
2821 else if (arg0
== old1
|| operand_equal_p (arg0
, old1
, 0))
2824 if (arg1
== old0
|| operand_equal_p (arg1
, old0
, 0))
2826 else if (arg1
== old1
|| operand_equal_p (arg1
, old1
, 0))
2829 return fold (build2 (code
, type
, arg0
, arg1
));
2837 /* Return a tree for the case when the result of an expression is RESULT
2838 converted to TYPE and OMITTED was previously an operand of the expression
2839 but is now not needed (e.g., we folded OMITTED * 0).
2841 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2842 the conversion of RESULT to TYPE. */
2845 omit_one_operand (tree type
, tree result
, tree omitted
)
2847 tree t
= fold_convert (type
, result
);
2849 if (TREE_SIDE_EFFECTS (omitted
))
2850 return build2 (COMPOUND_EXPR
, type
, fold_ignored_result (omitted
), t
);
2852 return non_lvalue (t
);
2855 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2858 pedantic_omit_one_operand (tree type
, tree result
, tree omitted
)
2860 tree t
= fold_convert (type
, result
);
2862 if (TREE_SIDE_EFFECTS (omitted
))
2863 return build2 (COMPOUND_EXPR
, type
, fold_ignored_result (omitted
), t
);
2865 return pedantic_non_lvalue (t
);
2868 /* Return a tree for the case when the result of an expression is RESULT
2869 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
2870 of the expression but are now not needed.
2872 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
2873 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
2874 evaluated before OMITTED2. Otherwise, if neither has side effects,
2875 just do the conversion of RESULT to TYPE. */
2878 omit_two_operands (tree type
, tree result
, tree omitted1
, tree omitted2
)
2880 tree t
= fold_convert (type
, result
);
2882 if (TREE_SIDE_EFFECTS (omitted2
))
2883 t
= build2 (COMPOUND_EXPR
, type
, omitted2
, t
);
2884 if (TREE_SIDE_EFFECTS (omitted1
))
2885 t
= build2 (COMPOUND_EXPR
, type
, omitted1
, t
);
2887 return TREE_CODE (t
) != COMPOUND_EXPR
? non_lvalue (t
) : t
;
2891 /* Return a simplified tree node for the truth-negation of ARG. This
2892 never alters ARG itself. We assume that ARG is an operation that
2893 returns a truth value (0 or 1).
2895 FIXME: one would think we would fold the result, but it causes
2896 problems with the dominator optimizer. */
2898 invert_truthvalue (tree arg
)
2900 tree type
= TREE_TYPE (arg
);
2901 enum tree_code code
= TREE_CODE (arg
);
2903 if (code
== ERROR_MARK
)
2906 /* If this is a comparison, we can simply invert it, except for
2907 floating-point non-equality comparisons, in which case we just
2908 enclose a TRUTH_NOT_EXPR around what we have. */
2910 if (TREE_CODE_CLASS (code
) == tcc_comparison
)
2912 tree op_type
= TREE_TYPE (TREE_OPERAND (arg
, 0));
2913 if (FLOAT_TYPE_P (op_type
)
2914 && flag_trapping_math
2915 && code
!= ORDERED_EXPR
&& code
!= UNORDERED_EXPR
2916 && code
!= NE_EXPR
&& code
!= EQ_EXPR
)
2917 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2920 code
= invert_tree_comparison (code
,
2921 HONOR_NANS (TYPE_MODE (op_type
)));
2922 if (code
== ERROR_MARK
)
2923 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2925 return build2 (code
, type
,
2926 TREE_OPERAND (arg
, 0), TREE_OPERAND (arg
, 1));
2933 return fold_convert (type
,
2934 build_int_cst (NULL_TREE
, integer_zerop (arg
)));
2936 case TRUTH_AND_EXPR
:
2937 return build2 (TRUTH_OR_EXPR
, type
,
2938 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2939 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2942 return build2 (TRUTH_AND_EXPR
, type
,
2943 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2944 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2946 case TRUTH_XOR_EXPR
:
2947 /* Here we can invert either operand. We invert the first operand
2948 unless the second operand is a TRUTH_NOT_EXPR in which case our
2949 result is the XOR of the first operand with the inside of the
2950 negation of the second operand. */
2952 if (TREE_CODE (TREE_OPERAND (arg
, 1)) == TRUTH_NOT_EXPR
)
2953 return build2 (TRUTH_XOR_EXPR
, type
, TREE_OPERAND (arg
, 0),
2954 TREE_OPERAND (TREE_OPERAND (arg
, 1), 0));
2956 return build2 (TRUTH_XOR_EXPR
, type
,
2957 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2958 TREE_OPERAND (arg
, 1));
2960 case TRUTH_ANDIF_EXPR
:
2961 return build2 (TRUTH_ORIF_EXPR
, type
,
2962 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2963 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2965 case TRUTH_ORIF_EXPR
:
2966 return build2 (TRUTH_ANDIF_EXPR
, type
,
2967 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2968 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2970 case TRUTH_NOT_EXPR
:
2971 return TREE_OPERAND (arg
, 0);
2974 return build3 (COND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2975 invert_truthvalue (TREE_OPERAND (arg
, 1)),
2976 invert_truthvalue (TREE_OPERAND (arg
, 2)));
2979 return build2 (COMPOUND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2980 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2982 case NON_LVALUE_EXPR
:
2983 return invert_truthvalue (TREE_OPERAND (arg
, 0));
2986 if (TREE_CODE (TREE_TYPE (arg
)) == BOOLEAN_TYPE
)
2991 return build1 (TREE_CODE (arg
), type
,
2992 invert_truthvalue (TREE_OPERAND (arg
, 0)));
2995 if (!integer_onep (TREE_OPERAND (arg
, 1)))
2997 return build2 (EQ_EXPR
, type
, arg
,
2998 fold_convert (type
, integer_zero_node
));
3001 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
3003 case CLEANUP_POINT_EXPR
:
3004 return build1 (CLEANUP_POINT_EXPR
, type
,
3005 invert_truthvalue (TREE_OPERAND (arg
, 0)));
3010 gcc_assert (TREE_CODE (TREE_TYPE (arg
)) == BOOLEAN_TYPE
);
3011 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
3014 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3015 operands are another bit-wise operation with a common input. If so,
3016 distribute the bit operations to save an operation and possibly two if
3017 constants are involved. For example, convert
3018 (A | B) & (A | C) into A | (B & C)
3019 Further simplification will occur if B and C are constants.
3021 If this optimization cannot be done, 0 will be returned. */
3024 distribute_bit_expr (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
3029 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
3030 || TREE_CODE (arg0
) == code
3031 || (TREE_CODE (arg0
) != BIT_AND_EXPR
3032 && TREE_CODE (arg0
) != BIT_IOR_EXPR
))
3035 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0))
3037 common
= TREE_OPERAND (arg0
, 0);
3038 left
= TREE_OPERAND (arg0
, 1);
3039 right
= TREE_OPERAND (arg1
, 1);
3041 else if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 1), 0))
3043 common
= TREE_OPERAND (arg0
, 0);
3044 left
= TREE_OPERAND (arg0
, 1);
3045 right
= TREE_OPERAND (arg1
, 0);
3047 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 0), 0))
3049 common
= TREE_OPERAND (arg0
, 1);
3050 left
= TREE_OPERAND (arg0
, 0);
3051 right
= TREE_OPERAND (arg1
, 1);
3053 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1), 0))
3055 common
= TREE_OPERAND (arg0
, 1);
3056 left
= TREE_OPERAND (arg0
, 0);
3057 right
= TREE_OPERAND (arg1
, 0);
3062 return fold (build2 (TREE_CODE (arg0
), type
, common
,
3063 fold (build2 (code
, type
, left
, right
))));
3066 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3067 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3070 make_bit_field_ref (tree inner
, tree type
, int bitsize
, int bitpos
,
3073 tree result
= build3 (BIT_FIELD_REF
, type
, inner
,
3074 size_int (bitsize
), bitsize_int (bitpos
));
3076 BIT_FIELD_REF_UNSIGNED (result
) = unsignedp
;
3081 /* Optimize a bit-field compare.
3083 There are two cases: First is a compare against a constant and the
3084 second is a comparison of two items where the fields are at the same
3085 bit position relative to the start of a chunk (byte, halfword, word)
3086 large enough to contain it. In these cases we can avoid the shift
3087 implicit in bitfield extractions.
3089 For constants, we emit a compare of the shifted constant with the
3090 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3091 compared. For two fields at the same position, we do the ANDs with the
3092 similar mask and compare the result of the ANDs.
3094 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3095 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3096 are the left and right operands of the comparison, respectively.
3098 If the optimization described above can be done, we return the resulting
3099 tree. Otherwise we return zero. */
3102 optimize_bit_field_compare (enum tree_code code
, tree compare_type
,
3105 HOST_WIDE_INT lbitpos
, lbitsize
, rbitpos
, rbitsize
, nbitpos
, nbitsize
;
3106 tree type
= TREE_TYPE (lhs
);
3107 tree signed_type
, unsigned_type
;
3108 int const_p
= TREE_CODE (rhs
) == INTEGER_CST
;
3109 enum machine_mode lmode
, rmode
, nmode
;
3110 int lunsignedp
, runsignedp
;
3111 int lvolatilep
= 0, rvolatilep
= 0;
3112 tree linner
, rinner
= NULL_TREE
;
3116 /* Get all the information about the extractions being done. If the bit size
3117 if the same as the size of the underlying object, we aren't doing an
3118 extraction at all and so can do nothing. We also don't want to
3119 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3120 then will no longer be able to replace it. */
3121 linner
= get_inner_reference (lhs
, &lbitsize
, &lbitpos
, &offset
, &lmode
,
3122 &lunsignedp
, &lvolatilep
);
3123 if (linner
== lhs
|| lbitsize
== GET_MODE_BITSIZE (lmode
) || lbitsize
< 0
3124 || offset
!= 0 || TREE_CODE (linner
) == PLACEHOLDER_EXPR
)
3129 /* If this is not a constant, we can only do something if bit positions,
3130 sizes, and signedness are the same. */
3131 rinner
= get_inner_reference (rhs
, &rbitsize
, &rbitpos
, &offset
, &rmode
,
3132 &runsignedp
, &rvolatilep
);
3134 if (rinner
== rhs
|| lbitpos
!= rbitpos
|| lbitsize
!= rbitsize
3135 || lunsignedp
!= runsignedp
|| offset
!= 0
3136 || TREE_CODE (rinner
) == PLACEHOLDER_EXPR
)
3140 /* See if we can find a mode to refer to this field. We should be able to,
3141 but fail if we can't. */
3142 nmode
= get_best_mode (lbitsize
, lbitpos
,
3143 const_p
? TYPE_ALIGN (TREE_TYPE (linner
))
3144 : MIN (TYPE_ALIGN (TREE_TYPE (linner
)),
3145 TYPE_ALIGN (TREE_TYPE (rinner
))),
3146 word_mode
, lvolatilep
|| rvolatilep
);
3147 if (nmode
== VOIDmode
)
3150 /* Set signed and unsigned types of the precision of this mode for the
3152 signed_type
= lang_hooks
.types
.type_for_mode (nmode
, 0);
3153 unsigned_type
= lang_hooks
.types
.type_for_mode (nmode
, 1);
3155 /* Compute the bit position and size for the new reference and our offset
3156 within it. If the new reference is the same size as the original, we
3157 won't optimize anything, so return zero. */
3158 nbitsize
= GET_MODE_BITSIZE (nmode
);
3159 nbitpos
= lbitpos
& ~ (nbitsize
- 1);
3161 if (nbitsize
== lbitsize
)
3164 if (BYTES_BIG_ENDIAN
)
3165 lbitpos
= nbitsize
- lbitsize
- lbitpos
;
3167 /* Make the mask to be used against the extracted field. */
3168 mask
= build_int_cst (unsigned_type
, -1);
3169 mask
= force_fit_type (mask
, 0, false, false);
3170 mask
= fold_convert (unsigned_type
, mask
);
3171 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (nbitsize
- lbitsize
), 0);
3172 mask
= const_binop (RSHIFT_EXPR
, mask
,
3173 size_int (nbitsize
- lbitsize
- lbitpos
), 0);
3176 /* If not comparing with constant, just rework the comparison
3178 return build2 (code
, compare_type
,
3179 build2 (BIT_AND_EXPR
, unsigned_type
,
3180 make_bit_field_ref (linner
, unsigned_type
,
3181 nbitsize
, nbitpos
, 1),
3183 build2 (BIT_AND_EXPR
, unsigned_type
,
3184 make_bit_field_ref (rinner
, unsigned_type
,
3185 nbitsize
, nbitpos
, 1),
3188 /* Otherwise, we are handling the constant case. See if the constant is too
3189 big for the field. Warn and return a tree of for 0 (false) if so. We do
3190 this not only for its own sake, but to avoid having to test for this
3191 error case below. If we didn't, we might generate wrong code.
3193 For unsigned fields, the constant shifted right by the field length should
3194 be all zero. For signed fields, the high-order bits should agree with
3199 if (! integer_zerop (const_binop (RSHIFT_EXPR
,
3200 fold_convert (unsigned_type
, rhs
),
3201 size_int (lbitsize
), 0)))
3203 warning ("comparison is always %d due to width of bit-field",
3205 return constant_boolean_node (code
== NE_EXPR
, compare_type
);
3210 tree tem
= const_binop (RSHIFT_EXPR
, fold_convert (signed_type
, rhs
),
3211 size_int (lbitsize
- 1), 0);
3212 if (! integer_zerop (tem
) && ! integer_all_onesp (tem
))
3214 warning ("comparison is always %d due to width of bit-field",
3216 return constant_boolean_node (code
== NE_EXPR
, compare_type
);
3220 /* Single-bit compares should always be against zero. */
3221 if (lbitsize
== 1 && ! integer_zerop (rhs
))
3223 code
= code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
;
3224 rhs
= fold_convert (type
, integer_zero_node
);
3227 /* Make a new bitfield reference, shift the constant over the
3228 appropriate number of bits and mask it with the computed mask
3229 (in case this was a signed field). If we changed it, make a new one. */
3230 lhs
= make_bit_field_ref (linner
, unsigned_type
, nbitsize
, nbitpos
, 1);
3233 TREE_SIDE_EFFECTS (lhs
) = 1;
3234 TREE_THIS_VOLATILE (lhs
) = 1;
3237 rhs
= fold (const_binop (BIT_AND_EXPR
,
3238 const_binop (LSHIFT_EXPR
,
3239 fold_convert (unsigned_type
, rhs
),
3240 size_int (lbitpos
), 0),
3243 return build2 (code
, compare_type
,
3244 build2 (BIT_AND_EXPR
, unsigned_type
, lhs
, mask
),
3248 /* Subroutine for fold_truthop: decode a field reference.
3250 If EXP is a comparison reference, we return the innermost reference.
3252 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3253 set to the starting bit number.
3255 If the innermost field can be completely contained in a mode-sized
3256 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3258 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3259 otherwise it is not changed.
3261 *PUNSIGNEDP is set to the signedness of the field.
3263 *PMASK is set to the mask used. This is either contained in a
3264 BIT_AND_EXPR or derived from the width of the field.
3266 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3268 Return 0 if this is not a component reference or is one that we can't
3269 do anything with. */
3272 decode_field_reference (tree exp
, HOST_WIDE_INT
*pbitsize
,
3273 HOST_WIDE_INT
*pbitpos
, enum machine_mode
*pmode
,
3274 int *punsignedp
, int *pvolatilep
,
3275 tree
*pmask
, tree
*pand_mask
)
3277 tree outer_type
= 0;
3279 tree mask
, inner
, offset
;
3281 unsigned int precision
;
3283 /* All the optimizations using this function assume integer fields.
3284 There are problems with FP fields since the type_for_size call
3285 below can fail for, e.g., XFmode. */
3286 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp
)))
3289 /* We are interested in the bare arrangement of bits, so strip everything
3290 that doesn't affect the machine mode. However, record the type of the
3291 outermost expression if it may matter below. */
3292 if (TREE_CODE (exp
) == NOP_EXPR
3293 || TREE_CODE (exp
) == CONVERT_EXPR
3294 || TREE_CODE (exp
) == NON_LVALUE_EXPR
)
3295 outer_type
= TREE_TYPE (exp
);
3298 if (TREE_CODE (exp
) == BIT_AND_EXPR
)
3300 and_mask
= TREE_OPERAND (exp
, 1);
3301 exp
= TREE_OPERAND (exp
, 0);
3302 STRIP_NOPS (exp
); STRIP_NOPS (and_mask
);
3303 if (TREE_CODE (and_mask
) != INTEGER_CST
)
3307 inner
= get_inner_reference (exp
, pbitsize
, pbitpos
, &offset
, pmode
,
3308 punsignedp
, pvolatilep
);
3309 if ((inner
== exp
&& and_mask
== 0)
3310 || *pbitsize
< 0 || offset
!= 0
3311 || TREE_CODE (inner
) == PLACEHOLDER_EXPR
)
3314 /* If the number of bits in the reference is the same as the bitsize of
3315 the outer type, then the outer type gives the signedness. Otherwise
3316 (in case of a small bitfield) the signedness is unchanged. */
3317 if (outer_type
&& *pbitsize
== TYPE_PRECISION (outer_type
))
3318 *punsignedp
= TYPE_UNSIGNED (outer_type
);
3320 /* Compute the mask to access the bitfield. */
3321 unsigned_type
= lang_hooks
.types
.type_for_size (*pbitsize
, 1);
3322 precision
= TYPE_PRECISION (unsigned_type
);
3324 mask
= build_int_cst (unsigned_type
, -1);
3325 mask
= force_fit_type (mask
, 0, false, false);
3327 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
3328 mask
= const_binop (RSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
3330 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3332 mask
= fold (build2 (BIT_AND_EXPR
, unsigned_type
,
3333 fold_convert (unsigned_type
, and_mask
), mask
));
3336 *pand_mask
= and_mask
;
3340 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3344 all_ones_mask_p (tree mask
, int size
)
3346 tree type
= TREE_TYPE (mask
);
3347 unsigned int precision
= TYPE_PRECISION (type
);
3350 tmask
= build_int_cst (lang_hooks
.types
.signed_type (type
), -1);
3351 tmask
= force_fit_type (tmask
, 0, false, false);
3354 tree_int_cst_equal (mask
,
3355 const_binop (RSHIFT_EXPR
,
3356 const_binop (LSHIFT_EXPR
, tmask
,
3357 size_int (precision
- size
),
3359 size_int (precision
- size
), 0));
3362 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3363 represents the sign bit of EXP's type. If EXP represents a sign
3364 or zero extension, also test VAL against the unextended type.
3365 The return value is the (sub)expression whose sign bit is VAL,
3366 or NULL_TREE otherwise. */
3369 sign_bit_p (tree exp
, tree val
)
3371 unsigned HOST_WIDE_INT mask_lo
, lo
;
3372 HOST_WIDE_INT mask_hi
, hi
;
3376 /* Tree EXP must have an integral type. */
3377 t
= TREE_TYPE (exp
);
3378 if (! INTEGRAL_TYPE_P (t
))
3381 /* Tree VAL must be an integer constant. */
3382 if (TREE_CODE (val
) != INTEGER_CST
3383 || TREE_CONSTANT_OVERFLOW (val
))
3386 width
= TYPE_PRECISION (t
);
3387 if (width
> HOST_BITS_PER_WIDE_INT
)
3389 hi
= (unsigned HOST_WIDE_INT
) 1 << (width
- HOST_BITS_PER_WIDE_INT
- 1);
3392 mask_hi
= ((unsigned HOST_WIDE_INT
) -1
3393 >> (2 * HOST_BITS_PER_WIDE_INT
- width
));
3399 lo
= (unsigned HOST_WIDE_INT
) 1 << (width
- 1);
3402 mask_lo
= ((unsigned HOST_WIDE_INT
) -1
3403 >> (HOST_BITS_PER_WIDE_INT
- width
));
3406 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3407 treat VAL as if it were unsigned. */
3408 if ((TREE_INT_CST_HIGH (val
) & mask_hi
) == hi
3409 && (TREE_INT_CST_LOW (val
) & mask_lo
) == lo
)
3412 /* Handle extension from a narrower type. */
3413 if (TREE_CODE (exp
) == NOP_EXPR
3414 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp
, 0))) < width
)
3415 return sign_bit_p (TREE_OPERAND (exp
, 0), val
);
3420 /* Subroutine for fold_truthop: determine if an operand is simple enough
3421 to be evaluated unconditionally. */
3424 simple_operand_p (tree exp
)
3426 /* Strip any conversions that don't change the machine mode. */
3429 return (CONSTANT_CLASS_P (exp
)
3430 || TREE_CODE (exp
) == SSA_NAME
3432 && ! TREE_ADDRESSABLE (exp
)
3433 && ! TREE_THIS_VOLATILE (exp
)
3434 && ! DECL_NONLOCAL (exp
)
3435 /* Don't regard global variables as simple. They may be
3436 allocated in ways unknown to the compiler (shared memory,
3437 #pragma weak, etc). */
3438 && ! TREE_PUBLIC (exp
)
3439 && ! DECL_EXTERNAL (exp
)
3440 /* Loading a static variable is unduly expensive, but global
3441 registers aren't expensive. */
3442 && (! TREE_STATIC (exp
) || DECL_REGISTER (exp
))));
3445 /* The following functions are subroutines to fold_range_test and allow it to
3446 try to change a logical combination of comparisons into a range test.
3449 X == 2 || X == 3 || X == 4 || X == 5
3453 (unsigned) (X - 2) <= 3
3455 We describe each set of comparisons as being either inside or outside
3456 a range, using a variable named like IN_P, and then describe the
3457 range with a lower and upper bound. If one of the bounds is omitted,
3458 it represents either the highest or lowest value of the type.
3460 In the comments below, we represent a range by two numbers in brackets
3461 preceded by a "+" to designate being inside that range, or a "-" to
3462 designate being outside that range, so the condition can be inverted by
3463 flipping the prefix. An omitted bound is represented by a "-". For
3464 example, "- [-, 10]" means being outside the range starting at the lowest
3465 possible value and ending at 10, in other words, being greater than 10.
3466 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3469 We set up things so that the missing bounds are handled in a consistent
3470 manner so neither a missing bound nor "true" and "false" need to be
3471 handled using a special case. */
3473 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3474 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3475 and UPPER1_P are nonzero if the respective argument is an upper bound
3476 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3477 must be specified for a comparison. ARG1 will be converted to ARG0's
3478 type if both are specified. */
3481 range_binop (enum tree_code code
, tree type
, tree arg0
, int upper0_p
,
3482 tree arg1
, int upper1_p
)
3488 /* If neither arg represents infinity, do the normal operation.
3489 Else, if not a comparison, return infinity. Else handle the special
3490 comparison rules. Note that most of the cases below won't occur, but
3491 are handled for consistency. */
3493 if (arg0
!= 0 && arg1
!= 0)
3495 tem
= fold (build2 (code
, type
!= 0 ? type
: TREE_TYPE (arg0
),
3496 arg0
, fold_convert (TREE_TYPE (arg0
), arg1
)));
3498 return TREE_CODE (tem
) == INTEGER_CST
? tem
: 0;
3501 if (TREE_CODE_CLASS (code
) != tcc_comparison
)
3504 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3505 for neither. In real maths, we cannot assume open ended ranges are
3506 the same. But, this is computer arithmetic, where numbers are finite.
3507 We can therefore make the transformation of any unbounded range with
3508 the value Z, Z being greater than any representable number. This permits
3509 us to treat unbounded ranges as equal. */
3510 sgn0
= arg0
!= 0 ? 0 : (upper0_p
? 1 : -1);
3511 sgn1
= arg1
!= 0 ? 0 : (upper1_p
? 1 : -1);
3515 result
= sgn0
== sgn1
;
3518 result
= sgn0
!= sgn1
;
3521 result
= sgn0
< sgn1
;
3524 result
= sgn0
<= sgn1
;
3527 result
= sgn0
> sgn1
;
3530 result
= sgn0
>= sgn1
;
3536 return constant_boolean_node (result
, type
);
3539 /* Given EXP, a logical expression, set the range it is testing into
3540 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3541 actually being tested. *PLOW and *PHIGH will be made of the same type
3542 as the returned expression. If EXP is not a comparison, we will most
3543 likely not be returning a useful value and range. */
3546 make_range (tree exp
, int *pin_p
, tree
*plow
, tree
*phigh
)
3548 enum tree_code code
;
3549 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
;
3550 tree exp_type
= NULL_TREE
, arg0_type
= NULL_TREE
;
3552 tree low
, high
, n_low
, n_high
;
3554 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3555 and see if we can refine the range. Some of the cases below may not
3556 happen, but it doesn't seem worth worrying about this. We "continue"
3557 the outer loop when we've changed something; otherwise we "break"
3558 the switch, which will "break" the while. */
3561 low
= high
= fold_convert (TREE_TYPE (exp
), integer_zero_node
);
3565 code
= TREE_CODE (exp
);
3566 exp_type
= TREE_TYPE (exp
);
3568 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code
)))
3570 if (first_rtl_op (code
) > 0)
3571 arg0
= TREE_OPERAND (exp
, 0);
3572 if (TREE_CODE_CLASS (code
) == tcc_comparison
3573 || TREE_CODE_CLASS (code
) == tcc_unary
3574 || TREE_CODE_CLASS (code
) == tcc_binary
)
3575 arg0_type
= TREE_TYPE (arg0
);
3576 if (TREE_CODE_CLASS (code
) == tcc_binary
3577 || TREE_CODE_CLASS (code
) == tcc_comparison
3578 || (TREE_CODE_CLASS (code
) == tcc_expression
3579 && TREE_CODE_LENGTH (code
) > 1))
3580 arg1
= TREE_OPERAND (exp
, 1);
3585 case TRUTH_NOT_EXPR
:
3586 in_p
= ! in_p
, exp
= arg0
;
3589 case EQ_EXPR
: case NE_EXPR
:
3590 case LT_EXPR
: case LE_EXPR
: case GE_EXPR
: case GT_EXPR
:
3591 /* We can only do something if the range is testing for zero
3592 and if the second operand is an integer constant. Note that
3593 saying something is "in" the range we make is done by
3594 complementing IN_P since it will set in the initial case of
3595 being not equal to zero; "out" is leaving it alone. */
3596 if (low
== 0 || high
== 0
3597 || ! integer_zerop (low
) || ! integer_zerop (high
)
3598 || TREE_CODE (arg1
) != INTEGER_CST
)
3603 case NE_EXPR
: /* - [c, c] */
3606 case EQ_EXPR
: /* + [c, c] */
3607 in_p
= ! in_p
, low
= high
= arg1
;
3609 case GT_EXPR
: /* - [-, c] */
3610 low
= 0, high
= arg1
;
3612 case GE_EXPR
: /* + [c, -] */
3613 in_p
= ! in_p
, low
= arg1
, high
= 0;
3615 case LT_EXPR
: /* - [c, -] */
3616 low
= arg1
, high
= 0;
3618 case LE_EXPR
: /* + [-, c] */
3619 in_p
= ! in_p
, low
= 0, high
= arg1
;
3625 /* If this is an unsigned comparison, we also know that EXP is
3626 greater than or equal to zero. We base the range tests we make
3627 on that fact, so we record it here so we can parse existing
3628 range tests. We test arg0_type since often the return type
3629 of, e.g. EQ_EXPR, is boolean. */
3630 if (TYPE_UNSIGNED (arg0_type
) && (low
== 0 || high
== 0))
3632 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3634 fold_convert (arg0_type
, integer_zero_node
),
3638 in_p
= n_in_p
, low
= n_low
, high
= n_high
;
3640 /* If the high bound is missing, but we have a nonzero low
3641 bound, reverse the range so it goes from zero to the low bound
3643 if (high
== 0 && low
&& ! integer_zerop (low
))
3646 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low
, 0,
3647 integer_one_node
, 0);
3648 low
= fold_convert (arg0_type
, integer_zero_node
);
3656 /* (-x) IN [a,b] -> x in [-b, -a] */
3657 n_low
= range_binop (MINUS_EXPR
, exp_type
,
3658 fold_convert (exp_type
, integer_zero_node
),
3660 n_high
= range_binop (MINUS_EXPR
, exp_type
,
3661 fold_convert (exp_type
, integer_zero_node
),
3663 low
= n_low
, high
= n_high
;
3669 exp
= build2 (MINUS_EXPR
, exp_type
, negate_expr (arg0
),
3670 fold_convert (exp_type
, integer_one_node
));
3673 case PLUS_EXPR
: case MINUS_EXPR
:
3674 if (TREE_CODE (arg1
) != INTEGER_CST
)
3677 /* If EXP is signed, any overflow in the computation is undefined,
3678 so we don't worry about it so long as our computations on
3679 the bounds don't overflow. For unsigned, overflow is defined
3680 and this is exactly the right thing. */
3681 n_low
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3682 arg0_type
, low
, 0, arg1
, 0);
3683 n_high
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3684 arg0_type
, high
, 1, arg1
, 0);
3685 if ((n_low
!= 0 && TREE_OVERFLOW (n_low
))
3686 || (n_high
!= 0 && TREE_OVERFLOW (n_high
)))
3689 /* Check for an unsigned range which has wrapped around the maximum
3690 value thus making n_high < n_low, and normalize it. */
3691 if (n_low
&& n_high
&& tree_int_cst_lt (n_high
, n_low
))
3693 low
= range_binop (PLUS_EXPR
, arg0_type
, n_high
, 0,
3694 integer_one_node
, 0);
3695 high
= range_binop (MINUS_EXPR
, arg0_type
, n_low
, 0,
3696 integer_one_node
, 0);
3698 /* If the range is of the form +/- [ x+1, x ], we won't
3699 be able to normalize it. But then, it represents the
3700 whole range or the empty set, so make it
3702 if (tree_int_cst_equal (n_low
, low
)
3703 && tree_int_cst_equal (n_high
, high
))
3709 low
= n_low
, high
= n_high
;
3714 case NOP_EXPR
: case NON_LVALUE_EXPR
: case CONVERT_EXPR
:
3715 if (TYPE_PRECISION (arg0_type
) > TYPE_PRECISION (exp_type
))
3718 if (! INTEGRAL_TYPE_P (arg0_type
)
3719 || (low
!= 0 && ! int_fits_type_p (low
, arg0_type
))
3720 || (high
!= 0 && ! int_fits_type_p (high
, arg0_type
)))
3723 n_low
= low
, n_high
= high
;
3726 n_low
= fold_convert (arg0_type
, n_low
);
3729 n_high
= fold_convert (arg0_type
, n_high
);
3732 /* If we're converting arg0 from an unsigned type, to exp,
3733 a signed type, we will be doing the comparison as unsigned.
3734 The tests above have already verified that LOW and HIGH
3737 So we have to ensure that we will handle large unsigned
3738 values the same way that the current signed bounds treat
3741 if (!TYPE_UNSIGNED (exp_type
) && TYPE_UNSIGNED (arg0_type
))
3744 tree equiv_type
= lang_hooks
.types
.type_for_mode
3745 (TYPE_MODE (arg0_type
), 1);
3747 /* A range without an upper bound is, naturally, unbounded.
3748 Since convert would have cropped a very large value, use
3749 the max value for the destination type. */
3751 = TYPE_MAX_VALUE (equiv_type
) ? TYPE_MAX_VALUE (equiv_type
)
3752 : TYPE_MAX_VALUE (arg0_type
);
3754 if (TYPE_PRECISION (exp_type
) == TYPE_PRECISION (arg0_type
))
3755 high_positive
= fold (build2 (RSHIFT_EXPR
, arg0_type
,
3756 fold_convert (arg0_type
,
3758 fold_convert (arg0_type
,
3759 integer_one_node
)));
3761 /* If the low bound is specified, "and" the range with the
3762 range for which the original unsigned value will be
3766 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3767 1, n_low
, n_high
, 1,
3768 fold_convert (arg0_type
,
3773 in_p
= (n_in_p
== in_p
);
3777 /* Otherwise, "or" the range with the range of the input
3778 that will be interpreted as negative. */
3779 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3780 0, n_low
, n_high
, 1,
3781 fold_convert (arg0_type
,
3786 in_p
= (in_p
!= n_in_p
);
3791 low
= n_low
, high
= n_high
;
3801 /* If EXP is a constant, we can evaluate whether this is true or false. */
3802 if (TREE_CODE (exp
) == INTEGER_CST
)
3804 in_p
= in_p
== (integer_onep (range_binop (GE_EXPR
, integer_type_node
,
3806 && integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3812 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
3816 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3817 type, TYPE, return an expression to test if EXP is in (or out of, depending
3818 on IN_P) the range. Return 0 if the test couldn't be created. */
3821 build_range_check (tree type
, tree exp
, int in_p
, tree low
, tree high
)
3823 tree etype
= TREE_TYPE (exp
);
3828 value
= build_range_check (type
, exp
, 1, low
, high
);
3830 return invert_truthvalue (value
);
3835 if (low
== 0 && high
== 0)
3836 return fold_convert (type
, integer_one_node
);
3839 return fold (build2 (LE_EXPR
, type
, exp
, high
));
3842 return fold (build2 (GE_EXPR
, type
, exp
, low
));
3844 if (operand_equal_p (low
, high
, 0))
3845 return fold (build2 (EQ_EXPR
, type
, exp
, low
));
3847 if (integer_zerop (low
))
3849 if (! TYPE_UNSIGNED (etype
))
3851 etype
= lang_hooks
.types
.unsigned_type (etype
);
3852 high
= fold_convert (etype
, high
);
3853 exp
= fold_convert (etype
, exp
);
3855 return build_range_check (type
, exp
, 1, 0, high
);
3858 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3859 if (integer_onep (low
) && TREE_CODE (high
) == INTEGER_CST
)
3861 unsigned HOST_WIDE_INT lo
;
3865 prec
= TYPE_PRECISION (etype
);
3866 if (prec
<= HOST_BITS_PER_WIDE_INT
)
3869 lo
= ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1)) - 1;
3873 hi
= ((HOST_WIDE_INT
) 1 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)) - 1;
3874 lo
= (unsigned HOST_WIDE_INT
) -1;
3877 if (TREE_INT_CST_HIGH (high
) == hi
&& TREE_INT_CST_LOW (high
) == lo
)
3879 if (TYPE_UNSIGNED (etype
))
3881 etype
= lang_hooks
.types
.signed_type (etype
);
3882 exp
= fold_convert (etype
, exp
);
3884 return fold (build2 (GT_EXPR
, type
, exp
,
3885 fold_convert (etype
, integer_zero_node
)));
3889 value
= const_binop (MINUS_EXPR
, high
, low
, 0);
3890 if (value
!= 0 && TREE_OVERFLOW (value
) && ! TYPE_UNSIGNED (etype
))
3892 tree utype
, minv
, maxv
;
3894 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
3895 for the type in question, as we rely on this here. */
3896 switch (TREE_CODE (etype
))
3901 utype
= lang_hooks
.types
.unsigned_type (etype
);
3902 maxv
= fold_convert (utype
, TYPE_MAX_VALUE (etype
));
3903 maxv
= range_binop (PLUS_EXPR
, NULL_TREE
, maxv
, 1,
3904 integer_one_node
, 1);
3905 minv
= fold_convert (utype
, TYPE_MIN_VALUE (etype
));
3906 if (integer_zerop (range_binop (NE_EXPR
, integer_type_node
,
3910 high
= fold_convert (etype
, high
);
3911 low
= fold_convert (etype
, low
);
3912 exp
= fold_convert (etype
, exp
);
3913 value
= const_binop (MINUS_EXPR
, high
, low
, 0);
3921 if (value
!= 0 && ! TREE_OVERFLOW (value
))
3922 return build_range_check (type
,
3923 fold (build2 (MINUS_EXPR
, etype
, exp
, low
)),
3924 1, fold_convert (etype
, integer_zero_node
),
3930 /* Given two ranges, see if we can merge them into one. Return 1 if we
3931 can, 0 if we can't. Set the output range into the specified parameters. */
3934 merge_ranges (int *pin_p
, tree
*plow
, tree
*phigh
, int in0_p
, tree low0
,
3935 tree high0
, int in1_p
, tree low1
, tree high1
)
3943 int lowequal
= ((low0
== 0 && low1
== 0)
3944 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3945 low0
, 0, low1
, 0)));
3946 int highequal
= ((high0
== 0 && high1
== 0)
3947 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3948 high0
, 1, high1
, 1)));
3950 /* Make range 0 be the range that starts first, or ends last if they
3951 start at the same value. Swap them if it isn't. */
3952 if (integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3955 && integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3956 high1
, 1, high0
, 1))))
3958 temp
= in0_p
, in0_p
= in1_p
, in1_p
= temp
;
3959 tem
= low0
, low0
= low1
, low1
= tem
;
3960 tem
= high0
, high0
= high1
, high1
= tem
;
3963 /* Now flag two cases, whether the ranges are disjoint or whether the
3964 second range is totally subsumed in the first. Note that the tests
3965 below are simplified by the ones above. */
3966 no_overlap
= integer_onep (range_binop (LT_EXPR
, integer_type_node
,
3967 high0
, 1, low1
, 0));
3968 subset
= integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3969 high1
, 1, high0
, 1));
3971 /* We now have four cases, depending on whether we are including or
3972 excluding the two ranges. */
3975 /* If they don't overlap, the result is false. If the second range
3976 is a subset it is the result. Otherwise, the range is from the start
3977 of the second to the end of the first. */
3979 in_p
= 0, low
= high
= 0;
3981 in_p
= 1, low
= low1
, high
= high1
;
3983 in_p
= 1, low
= low1
, high
= high0
;
3986 else if (in0_p
&& ! in1_p
)
3988 /* If they don't overlap, the result is the first range. If they are
3989 equal, the result is false. If the second range is a subset of the
3990 first, and the ranges begin at the same place, we go from just after
3991 the end of the first range to the end of the second. If the second
3992 range is not a subset of the first, or if it is a subset and both
3993 ranges end at the same place, the range starts at the start of the
3994 first range and ends just before the second range.
3995 Otherwise, we can't describe this as a single range. */
3997 in_p
= 1, low
= low0
, high
= high0
;
3998 else if (lowequal
&& highequal
)
3999 in_p
= 0, low
= high
= 0;
4000 else if (subset
&& lowequal
)
4002 in_p
= 1, high
= high0
;
4003 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high1
, 0,
4004 integer_one_node
, 0);
4006 else if (! subset
|| highequal
)
4008 in_p
= 1, low
= low0
;
4009 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low1
, 0,
4010 integer_one_node
, 0);
4016 else if (! in0_p
&& in1_p
)
4018 /* If they don't overlap, the result is the second range. If the second
4019 is a subset of the first, the result is false. Otherwise,
4020 the range starts just after the first range and ends at the
4021 end of the second. */
4023 in_p
= 1, low
= low1
, high
= high1
;
4024 else if (subset
|| highequal
)
4025 in_p
= 0, low
= high
= 0;
4028 in_p
= 1, high
= high1
;
4029 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high0
, 1,
4030 integer_one_node
, 0);
4036 /* The case where we are excluding both ranges. Here the complex case
4037 is if they don't overlap. In that case, the only time we have a
4038 range is if they are adjacent. If the second is a subset of the
4039 first, the result is the first. Otherwise, the range to exclude
4040 starts at the beginning of the first range and ends at the end of the
4044 if (integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
4045 range_binop (PLUS_EXPR
, NULL_TREE
,
4047 integer_one_node
, 1),
4049 in_p
= 0, low
= low0
, high
= high1
;
4052 /* Canonicalize - [min, x] into - [-, x]. */
4053 if (low0
&& TREE_CODE (low0
) == INTEGER_CST
)
4054 switch (TREE_CODE (TREE_TYPE (low0
)))
4057 if (TYPE_PRECISION (TREE_TYPE (low0
))
4058 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0
))))
4063 if (tree_int_cst_equal (low0
,
4064 TYPE_MIN_VALUE (TREE_TYPE (low0
))))
4068 if (TYPE_UNSIGNED (TREE_TYPE (low0
))
4069 && integer_zerop (low0
))
4076 /* Canonicalize - [x, max] into - [x, -]. */
4077 if (high1
&& TREE_CODE (high1
) == INTEGER_CST
)
4078 switch (TREE_CODE (TREE_TYPE (high1
)))
4081 if (TYPE_PRECISION (TREE_TYPE (high1
))
4082 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1
))))
4087 if (tree_int_cst_equal (high1
,
4088 TYPE_MAX_VALUE (TREE_TYPE (high1
))))
4092 if (TYPE_UNSIGNED (TREE_TYPE (high1
))
4093 && integer_zerop (range_binop (PLUS_EXPR
, NULL_TREE
,
4095 integer_one_node
, 1)))
4102 /* The ranges might be also adjacent between the maximum and
4103 minimum values of the given type. For
4104 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4105 return + [x + 1, y - 1]. */
4106 if (low0
== 0 && high1
== 0)
4108 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high0
, 1,
4109 integer_one_node
, 1);
4110 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low1
, 0,
4111 integer_one_node
, 0);
4112 if (low
== 0 || high
== 0)
4122 in_p
= 0, low
= low0
, high
= high0
;
4124 in_p
= 0, low
= low0
, high
= high1
;
4127 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
4132 /* Subroutine of fold, looking inside expressions of the form
4133 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
4134 of the COND_EXPR. This function is being used also to optimize
4135 A op B ? C : A, by reversing the comparison first.
4137 Return a folded expression whose code is not a COND_EXPR
4138 anymore, or NULL_TREE if no folding opportunity is found. */
4141 fold_cond_expr_with_comparison (tree type
, tree arg0
, tree arg1
, tree arg2
)
4143 enum tree_code comp_code
= TREE_CODE (arg0
);
4144 tree arg00
= TREE_OPERAND (arg0
, 0);
4145 tree arg01
= TREE_OPERAND (arg0
, 1);
4146 tree arg1_type
= TREE_TYPE (arg1
);
4152 /* If we have A op 0 ? A : -A, consider applying the following
4155 A == 0? A : -A same as -A
4156 A != 0? A : -A same as A
4157 A >= 0? A : -A same as abs (A)
4158 A > 0? A : -A same as abs (A)
4159 A <= 0? A : -A same as -abs (A)
4160 A < 0? A : -A same as -abs (A)
4162 None of these transformations work for modes with signed
4163 zeros. If A is +/-0, the first two transformations will
4164 change the sign of the result (from +0 to -0, or vice
4165 versa). The last four will fix the sign of the result,
4166 even though the original expressions could be positive or
4167 negative, depending on the sign of A.
4169 Note that all these transformations are correct if A is
4170 NaN, since the two alternatives (A and -A) are also NaNs. */
4171 if ((FLOAT_TYPE_P (TREE_TYPE (arg01
))
4172 ? real_zerop (arg01
)
4173 : integer_zerop (arg01
))
4174 && TREE_CODE (arg2
) == NEGATE_EXPR
4175 && operand_equal_p (TREE_OPERAND (arg2
, 0), arg1
, 0))
4180 tem
= fold_convert (arg1_type
, arg1
);
4181 return pedantic_non_lvalue (fold_convert (type
, negate_expr (tem
)));
4184 return pedantic_non_lvalue (fold_convert (type
, arg1
));
4187 if (flag_trapping_math
)
4192 if (TYPE_UNSIGNED (TREE_TYPE (arg1
)))
4193 arg1
= fold_convert (lang_hooks
.types
.signed_type
4194 (TREE_TYPE (arg1
)), arg1
);
4195 tem
= fold (build1 (ABS_EXPR
, TREE_TYPE (arg1
), arg1
));
4196 return pedantic_non_lvalue (fold_convert (type
, tem
));
4199 if (flag_trapping_math
)
4203 if (TYPE_UNSIGNED (TREE_TYPE (arg1
)))
4204 arg1
= fold_convert (lang_hooks
.types
.signed_type
4205 (TREE_TYPE (arg1
)), arg1
);
4206 tem
= fold (build1 (ABS_EXPR
, TREE_TYPE (arg1
), arg1
));
4207 return negate_expr (fold_convert (type
, tem
));
4209 gcc_assert (TREE_CODE_CLASS (comp_code
) == tcc_comparison
);
4213 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4214 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4215 both transformations are correct when A is NaN: A != 0
4216 is then true, and A == 0 is false. */
4218 if (integer_zerop (arg01
) && integer_zerop (arg2
))
4220 if (comp_code
== NE_EXPR
)
4221 return pedantic_non_lvalue (fold_convert (type
, arg1
));
4222 else if (comp_code
== EQ_EXPR
)
4223 return fold_convert (type
, integer_zero_node
);
4226 /* Try some transformations of A op B ? A : B.
4228 A == B? A : B same as B
4229 A != B? A : B same as A
4230 A >= B? A : B same as max (A, B)
4231 A > B? A : B same as max (B, A)
4232 A <= B? A : B same as min (A, B)
4233 A < B? A : B same as min (B, A)
4235 As above, these transformations don't work in the presence
4236 of signed zeros. For example, if A and B are zeros of
4237 opposite sign, the first two transformations will change
4238 the sign of the result. In the last four, the original
4239 expressions give different results for (A=+0, B=-0) and
4240 (A=-0, B=+0), but the transformed expressions do not.
4242 The first two transformations are correct if either A or B
4243 is a NaN. In the first transformation, the condition will
4244 be false, and B will indeed be chosen. In the case of the
4245 second transformation, the condition A != B will be true,
4246 and A will be chosen.
4248 The conversions to max() and min() are not correct if B is
4249 a number and A is not. The conditions in the original
4250 expressions will be false, so all four give B. The min()
4251 and max() versions would give a NaN instead. */
4252 if (operand_equal_for_comparison_p (arg01
, arg2
, arg00
))
4254 tree comp_op0
= arg00
;
4255 tree comp_op1
= arg01
;
4256 tree comp_type
= TREE_TYPE (comp_op0
);
4258 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4259 if (TYPE_MAIN_VARIANT (comp_type
) == TYPE_MAIN_VARIANT (type
))
4269 return pedantic_non_lvalue (fold_convert (type
, arg2
));
4271 return pedantic_non_lvalue (fold_convert (type
, arg1
));
4276 /* In C++ a ?: expression can be an lvalue, so put the
4277 operand which will be used if they are equal first
4278 so that we can convert this back to the
4279 corresponding COND_EXPR. */
4280 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
4282 comp_op0
= fold_convert (comp_type
, comp_op0
);
4283 comp_op1
= fold_convert (comp_type
, comp_op1
);
4284 tem
= (comp_code
== LE_EXPR
|| comp_code
== UNLE_EXPR
)
4285 ? fold (build2 (MIN_EXPR
, comp_type
, comp_op0
, comp_op1
))
4286 : fold (build2 (MIN_EXPR
, comp_type
, comp_op1
, comp_op0
));
4287 return pedantic_non_lvalue (fold_convert (type
, tem
));
4294 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
4296 comp_op0
= fold_convert (comp_type
, comp_op0
);
4297 comp_op1
= fold_convert (comp_type
, comp_op1
);
4298 tem
= (comp_code
== GE_EXPR
|| comp_code
== UNGE_EXPR
)
4299 ? fold (build2 (MAX_EXPR
, comp_type
, comp_op0
, comp_op1
))
4300 : fold (build2 (MAX_EXPR
, comp_type
, comp_op1
, comp_op0
));
4301 return pedantic_non_lvalue (fold_convert (type
, tem
));
4305 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
4306 return pedantic_non_lvalue (fold_convert (type
, arg2
));
4309 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
4310 return pedantic_non_lvalue (fold_convert (type
, arg1
));
4313 gcc_assert (TREE_CODE_CLASS (comp_code
) == tcc_comparison
);
4318 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
4319 we might still be able to simplify this. For example,
4320 if C1 is one less or one more than C2, this might have started
4321 out as a MIN or MAX and been transformed by this function.
4322 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
4324 if (INTEGRAL_TYPE_P (type
)
4325 && TREE_CODE (arg01
) == INTEGER_CST
4326 && TREE_CODE (arg2
) == INTEGER_CST
)
4330 /* We can replace A with C1 in this case. */
4331 arg1
= fold_convert (type
, arg01
);
4332 return fold (build3 (COND_EXPR
, type
, arg0
, arg1
, arg2
));
4335 /* If C1 is C2 + 1, this is min(A, C2). */
4336 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
),
4338 && operand_equal_p (arg01
,
4339 const_binop (PLUS_EXPR
, arg2
,
4340 integer_one_node
, 0),
4342 return pedantic_non_lvalue (fold (build2 (MIN_EXPR
,
4343 type
, arg1
, arg2
)));
4347 /* If C1 is C2 - 1, this is min(A, C2). */
4348 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
),
4350 && operand_equal_p (arg01
,
4351 const_binop (MINUS_EXPR
, arg2
,
4352 integer_one_node
, 0),
4354 return pedantic_non_lvalue (fold (build2 (MIN_EXPR
,
4355 type
, arg1
, arg2
)));
4359 /* If C1 is C2 - 1, this is max(A, C2). */
4360 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
),
4362 && operand_equal_p (arg01
,
4363 const_binop (MINUS_EXPR
, arg2
,
4364 integer_one_node
, 0),
4366 return pedantic_non_lvalue (fold (build2 (MAX_EXPR
,
4367 type
, arg1
, arg2
)));
4371 /* If C1 is C2 + 1, this is max(A, C2). */
4372 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
),
4374 && operand_equal_p (arg01
,
4375 const_binop (PLUS_EXPR
, arg2
,
4376 integer_one_node
, 0),
4378 return pedantic_non_lvalue (fold (build2 (MAX_EXPR
,
4379 type
, arg1
, arg2
)));
4392 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
4393 #define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
4396 /* EXP is some logical combination of boolean tests. See if we can
4397 merge it into some range test. Return the new tree if so. */
4400 fold_range_test (tree exp
)
4402 int or_op
= (TREE_CODE (exp
) == TRUTH_ORIF_EXPR
4403 || TREE_CODE (exp
) == TRUTH_OR_EXPR
);
4404 int in0_p
, in1_p
, in_p
;
4405 tree low0
, low1
, low
, high0
, high1
, high
;
4406 tree lhs
= make_range (TREE_OPERAND (exp
, 0), &in0_p
, &low0
, &high0
);
4407 tree rhs
= make_range (TREE_OPERAND (exp
, 1), &in1_p
, &low1
, &high1
);
4410 /* If this is an OR operation, invert both sides; we will invert
4411 again at the end. */
4413 in0_p
= ! in0_p
, in1_p
= ! in1_p
;
4415 /* If both expressions are the same, if we can merge the ranges, and we
4416 can build the range test, return it or it inverted. If one of the
4417 ranges is always true or always false, consider it to be the same
4418 expression as the other. */
4419 if ((lhs
== 0 || rhs
== 0 || operand_equal_p (lhs
, rhs
, 0))
4420 && merge_ranges (&in_p
, &low
, &high
, in0_p
, low0
, high0
,
4422 && 0 != (tem
= (build_range_check (TREE_TYPE (exp
),
4424 : rhs
!= 0 ? rhs
: integer_zero_node
,
4426 return or_op
? invert_truthvalue (tem
) : tem
;
4428 /* On machines where the branch cost is expensive, if this is a
4429 short-circuited branch and the underlying object on both sides
4430 is the same, make a non-short-circuit operation. */
4431 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
4432 && lhs
!= 0 && rhs
!= 0
4433 && (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
4434 || TREE_CODE (exp
) == TRUTH_ORIF_EXPR
)
4435 && operand_equal_p (lhs
, rhs
, 0))
4437 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
4438 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
4439 which cases we can't do this. */
4440 if (simple_operand_p (lhs
))
4441 return build2 (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
4442 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
4443 TREE_TYPE (exp
), TREE_OPERAND (exp
, 0),
4444 TREE_OPERAND (exp
, 1));
4446 else if (lang_hooks
.decls
.global_bindings_p () == 0
4447 && ! CONTAINS_PLACEHOLDER_P (lhs
))
4449 tree common
= save_expr (lhs
);
4451 if (0 != (lhs
= build_range_check (TREE_TYPE (exp
), common
,
4452 or_op
? ! in0_p
: in0_p
,
4454 && (0 != (rhs
= build_range_check (TREE_TYPE (exp
), common
,
4455 or_op
? ! in1_p
: in1_p
,
4457 return build2 (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
4458 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
4459 TREE_TYPE (exp
), lhs
, rhs
);
4466 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
4467 bit value. Arrange things so the extra bits will be set to zero if and
4468 only if C is signed-extended to its full width. If MASK is nonzero,
4469 it is an INTEGER_CST that should be AND'ed with the extra bits. */
4472 unextend (tree c
, int p
, int unsignedp
, tree mask
)
4474 tree type
= TREE_TYPE (c
);
4475 int modesize
= GET_MODE_BITSIZE (TYPE_MODE (type
));
4478 if (p
== modesize
|| unsignedp
)
4481 /* We work by getting just the sign bit into the low-order bit, then
4482 into the high-order bit, then sign-extend. We then XOR that value
4484 temp
= const_binop (RSHIFT_EXPR
, c
, size_int (p
- 1), 0);
4485 temp
= const_binop (BIT_AND_EXPR
, temp
, size_int (1), 0);
4487 /* We must use a signed type in order to get an arithmetic right shift.
4488 However, we must also avoid introducing accidental overflows, so that
4489 a subsequent call to integer_zerop will work. Hence we must
4490 do the type conversion here. At this point, the constant is either
4491 zero or one, and the conversion to a signed type can never overflow.
4492 We could get an overflow if this conversion is done anywhere else. */
4493 if (TYPE_UNSIGNED (type
))
4494 temp
= fold_convert (lang_hooks
.types
.signed_type (type
), temp
);
4496 temp
= const_binop (LSHIFT_EXPR
, temp
, size_int (modesize
- 1), 0);
4497 temp
= const_binop (RSHIFT_EXPR
, temp
, size_int (modesize
- p
- 1), 0);
4499 temp
= const_binop (BIT_AND_EXPR
, temp
,
4500 fold_convert (TREE_TYPE (c
), mask
), 0);
4501 /* If necessary, convert the type back to match the type of C. */
4502 if (TYPE_UNSIGNED (type
))
4503 temp
= fold_convert (type
, temp
);
4505 return fold_convert (type
, const_binop (BIT_XOR_EXPR
, c
, temp
, 0));
4508 /* Find ways of folding logical expressions of LHS and RHS:
4509 Try to merge two comparisons to the same innermost item.
4510 Look for range tests like "ch >= '0' && ch <= '9'".
4511 Look for combinations of simple terms on machines with expensive branches
4512 and evaluate the RHS unconditionally.
4514 For example, if we have p->a == 2 && p->b == 4 and we can make an
4515 object large enough to span both A and B, we can do this with a comparison
4516 against the object ANDed with the a mask.
4518 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
4519 operations to do this with one comparison.
4521 We check for both normal comparisons and the BIT_AND_EXPRs made this by
4522 function and the one above.
4524 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
4525 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
4527 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
4530 We return the simplified tree or 0 if no optimization is possible. */
4533 fold_truthop (enum tree_code code
, tree truth_type
, tree lhs
, tree rhs
)
4535 /* If this is the "or" of two comparisons, we can do something if
4536 the comparisons are NE_EXPR. If this is the "and", we can do something
4537 if the comparisons are EQ_EXPR. I.e.,
4538 (a->b == 2 && a->c == 4) can become (a->new == NEW).
4540 WANTED_CODE is this operation code. For single bit fields, we can
4541 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
4542 comparison for one-bit fields. */
4544 enum tree_code wanted_code
;
4545 enum tree_code lcode
, rcode
;
4546 tree ll_arg
, lr_arg
, rl_arg
, rr_arg
;
4547 tree ll_inner
, lr_inner
, rl_inner
, rr_inner
;
4548 HOST_WIDE_INT ll_bitsize
, ll_bitpos
, lr_bitsize
, lr_bitpos
;
4549 HOST_WIDE_INT rl_bitsize
, rl_bitpos
, rr_bitsize
, rr_bitpos
;
4550 HOST_WIDE_INT xll_bitpos
, xlr_bitpos
, xrl_bitpos
, xrr_bitpos
;
4551 HOST_WIDE_INT lnbitsize
, lnbitpos
, rnbitsize
, rnbitpos
;
4552 int ll_unsignedp
, lr_unsignedp
, rl_unsignedp
, rr_unsignedp
;
4553 enum machine_mode ll_mode
, lr_mode
, rl_mode
, rr_mode
;
4554 enum machine_mode lnmode
, rnmode
;
4555 tree ll_mask
, lr_mask
, rl_mask
, rr_mask
;
4556 tree ll_and_mask
, lr_and_mask
, rl_and_mask
, rr_and_mask
;
4557 tree l_const
, r_const
;
4558 tree lntype
, rntype
, result
;
4559 int first_bit
, end_bit
;
4562 /* Start by getting the comparison codes. Fail if anything is volatile.
4563 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
4564 it were surrounded with a NE_EXPR. */
4566 if (TREE_SIDE_EFFECTS (lhs
) || TREE_SIDE_EFFECTS (rhs
))
4569 lcode
= TREE_CODE (lhs
);
4570 rcode
= TREE_CODE (rhs
);
4572 if (lcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (lhs
, 1)))
4574 lhs
= build2 (NE_EXPR
, truth_type
, lhs
,
4575 fold_convert (TREE_TYPE (lhs
), integer_zero_node
));
4579 if (rcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (rhs
, 1)))
4581 rhs
= build2 (NE_EXPR
, truth_type
, rhs
,
4582 fold_convert (TREE_TYPE (rhs
), integer_zero_node
));
4586 if (TREE_CODE_CLASS (lcode
) != tcc_comparison
4587 || TREE_CODE_CLASS (rcode
) != tcc_comparison
)
4590 ll_arg
= TREE_OPERAND (lhs
, 0);
4591 lr_arg
= TREE_OPERAND (lhs
, 1);
4592 rl_arg
= TREE_OPERAND (rhs
, 0);
4593 rr_arg
= TREE_OPERAND (rhs
, 1);
4595 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
4596 if (simple_operand_p (ll_arg
)
4597 && simple_operand_p (lr_arg
))
4600 if (operand_equal_p (ll_arg
, rl_arg
, 0)
4601 && operand_equal_p (lr_arg
, rr_arg
, 0))
4603 result
= combine_comparisons (code
, lcode
, rcode
,
4604 truth_type
, ll_arg
, lr_arg
);
4608 else if (operand_equal_p (ll_arg
, rr_arg
, 0)
4609 && operand_equal_p (lr_arg
, rl_arg
, 0))
4611 result
= combine_comparisons (code
, lcode
,
4612 swap_tree_comparison (rcode
),
4613 truth_type
, ll_arg
, lr_arg
);
4619 code
= ((code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
)
4620 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
);
4622 /* If the RHS can be evaluated unconditionally and its operands are
4623 simple, it wins to evaluate the RHS unconditionally on machines
4624 with expensive branches. In this case, this isn't a comparison
4625 that can be merged. Avoid doing this if the RHS is a floating-point
4626 comparison since those can trap. */
4628 if (BRANCH_COST
>= 2
4629 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg
))
4630 && simple_operand_p (rl_arg
)
4631 && simple_operand_p (rr_arg
))
4633 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
4634 if (code
== TRUTH_OR_EXPR
4635 && lcode
== NE_EXPR
&& integer_zerop (lr_arg
)
4636 && rcode
== NE_EXPR
&& integer_zerop (rr_arg
)
4637 && TREE_TYPE (ll_arg
) == TREE_TYPE (rl_arg
))
4638 return build2 (NE_EXPR
, truth_type
,
4639 build2 (BIT_IOR_EXPR
, TREE_TYPE (ll_arg
),
4641 fold_convert (TREE_TYPE (ll_arg
), integer_zero_node
));
4643 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
4644 if (code
== TRUTH_AND_EXPR
4645 && lcode
== EQ_EXPR
&& integer_zerop (lr_arg
)
4646 && rcode
== EQ_EXPR
&& integer_zerop (rr_arg
)
4647 && TREE_TYPE (ll_arg
) == TREE_TYPE (rl_arg
))
4648 return build2 (EQ_EXPR
, truth_type
,
4649 build2 (BIT_IOR_EXPR
, TREE_TYPE (ll_arg
),
4651 fold_convert (TREE_TYPE (ll_arg
), integer_zero_node
));
4653 if (LOGICAL_OP_NON_SHORT_CIRCUIT
)
4654 return build2 (code
, truth_type
, lhs
, rhs
);
4657 /* See if the comparisons can be merged. Then get all the parameters for
4660 if ((lcode
!= EQ_EXPR
&& lcode
!= NE_EXPR
)
4661 || (rcode
!= EQ_EXPR
&& rcode
!= NE_EXPR
))
4665 ll_inner
= decode_field_reference (ll_arg
,
4666 &ll_bitsize
, &ll_bitpos
, &ll_mode
,
4667 &ll_unsignedp
, &volatilep
, &ll_mask
,
4669 lr_inner
= decode_field_reference (lr_arg
,
4670 &lr_bitsize
, &lr_bitpos
, &lr_mode
,
4671 &lr_unsignedp
, &volatilep
, &lr_mask
,
4673 rl_inner
= decode_field_reference (rl_arg
,
4674 &rl_bitsize
, &rl_bitpos
, &rl_mode
,
4675 &rl_unsignedp
, &volatilep
, &rl_mask
,
4677 rr_inner
= decode_field_reference (rr_arg
,
4678 &rr_bitsize
, &rr_bitpos
, &rr_mode
,
4679 &rr_unsignedp
, &volatilep
, &rr_mask
,
4682 /* It must be true that the inner operation on the lhs of each
4683 comparison must be the same if we are to be able to do anything.
4684 Then see if we have constants. If not, the same must be true for
4686 if (volatilep
|| ll_inner
== 0 || rl_inner
== 0
4687 || ! operand_equal_p (ll_inner
, rl_inner
, 0))
4690 if (TREE_CODE (lr_arg
) == INTEGER_CST
4691 && TREE_CODE (rr_arg
) == INTEGER_CST
)
4692 l_const
= lr_arg
, r_const
= rr_arg
;
4693 else if (lr_inner
== 0 || rr_inner
== 0
4694 || ! operand_equal_p (lr_inner
, rr_inner
, 0))
4697 l_const
= r_const
= 0;
4699 /* If either comparison code is not correct for our logical operation,
4700 fail. However, we can convert a one-bit comparison against zero into
4701 the opposite comparison against that bit being set in the field. */
4703 wanted_code
= (code
== TRUTH_AND_EXPR
? EQ_EXPR
: NE_EXPR
);
4704 if (lcode
!= wanted_code
)
4706 if (l_const
&& integer_zerop (l_const
) && integer_pow2p (ll_mask
))
4708 /* Make the left operand unsigned, since we are only interested
4709 in the value of one bit. Otherwise we are doing the wrong
4718 /* This is analogous to the code for l_const above. */
4719 if (rcode
!= wanted_code
)
4721 if (r_const
&& integer_zerop (r_const
) && integer_pow2p (rl_mask
))
4730 /* After this point all optimizations will generate bit-field
4731 references, which we might not want. */
4732 if (! lang_hooks
.can_use_bit_fields_p ())
4735 /* See if we can find a mode that contains both fields being compared on
4736 the left. If we can't, fail. Otherwise, update all constants and masks
4737 to be relative to a field of that size. */
4738 first_bit
= MIN (ll_bitpos
, rl_bitpos
);
4739 end_bit
= MAX (ll_bitpos
+ ll_bitsize
, rl_bitpos
+ rl_bitsize
);
4740 lnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
4741 TYPE_ALIGN (TREE_TYPE (ll_inner
)), word_mode
,
4743 if (lnmode
== VOIDmode
)
4746 lnbitsize
= GET_MODE_BITSIZE (lnmode
);
4747 lnbitpos
= first_bit
& ~ (lnbitsize
- 1);
4748 lntype
= lang_hooks
.types
.type_for_size (lnbitsize
, 1);
4749 xll_bitpos
= ll_bitpos
- lnbitpos
, xrl_bitpos
= rl_bitpos
- lnbitpos
;
4751 if (BYTES_BIG_ENDIAN
)
4753 xll_bitpos
= lnbitsize
- xll_bitpos
- ll_bitsize
;
4754 xrl_bitpos
= lnbitsize
- xrl_bitpos
- rl_bitsize
;
4757 ll_mask
= const_binop (LSHIFT_EXPR
, fold_convert (lntype
, ll_mask
),
4758 size_int (xll_bitpos
), 0);
4759 rl_mask
= const_binop (LSHIFT_EXPR
, fold_convert (lntype
, rl_mask
),
4760 size_int (xrl_bitpos
), 0);
4764 l_const
= fold_convert (lntype
, l_const
);
4765 l_const
= unextend (l_const
, ll_bitsize
, ll_unsignedp
, ll_and_mask
);
4766 l_const
= const_binop (LSHIFT_EXPR
, l_const
, size_int (xll_bitpos
), 0);
4767 if (! integer_zerop (const_binop (BIT_AND_EXPR
, l_const
,
4768 fold (build1 (BIT_NOT_EXPR
,
4772 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
4774 return constant_boolean_node (wanted_code
== NE_EXPR
, truth_type
);
4779 r_const
= fold_convert (lntype
, r_const
);
4780 r_const
= unextend (r_const
, rl_bitsize
, rl_unsignedp
, rl_and_mask
);
4781 r_const
= const_binop (LSHIFT_EXPR
, r_const
, size_int (xrl_bitpos
), 0);
4782 if (! integer_zerop (const_binop (BIT_AND_EXPR
, r_const
,
4783 fold (build1 (BIT_NOT_EXPR
,
4787 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
4789 return constant_boolean_node (wanted_code
== NE_EXPR
, truth_type
);
4793 /* If the right sides are not constant, do the same for it. Also,
4794 disallow this optimization if a size or signedness mismatch occurs
4795 between the left and right sides. */
4798 if (ll_bitsize
!= lr_bitsize
|| rl_bitsize
!= rr_bitsize
4799 || ll_unsignedp
!= lr_unsignedp
|| rl_unsignedp
!= rr_unsignedp
4800 /* Make sure the two fields on the right
4801 correspond to the left without being swapped. */
4802 || ll_bitpos
- rl_bitpos
!= lr_bitpos
- rr_bitpos
)
4805 first_bit
= MIN (lr_bitpos
, rr_bitpos
);
4806 end_bit
= MAX (lr_bitpos
+ lr_bitsize
, rr_bitpos
+ rr_bitsize
);
4807 rnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
4808 TYPE_ALIGN (TREE_TYPE (lr_inner
)), word_mode
,
4810 if (rnmode
== VOIDmode
)
4813 rnbitsize
= GET_MODE_BITSIZE (rnmode
);
4814 rnbitpos
= first_bit
& ~ (rnbitsize
- 1);
4815 rntype
= lang_hooks
.types
.type_for_size (rnbitsize
, 1);
4816 xlr_bitpos
= lr_bitpos
- rnbitpos
, xrr_bitpos
= rr_bitpos
- rnbitpos
;
4818 if (BYTES_BIG_ENDIAN
)
4820 xlr_bitpos
= rnbitsize
- xlr_bitpos
- lr_bitsize
;
4821 xrr_bitpos
= rnbitsize
- xrr_bitpos
- rr_bitsize
;
4824 lr_mask
= const_binop (LSHIFT_EXPR
, fold_convert (rntype
, lr_mask
),
4825 size_int (xlr_bitpos
), 0);
4826 rr_mask
= const_binop (LSHIFT_EXPR
, fold_convert (rntype
, rr_mask
),
4827 size_int (xrr_bitpos
), 0);
4829 /* Make a mask that corresponds to both fields being compared.
4830 Do this for both items being compared. If the operands are the
4831 same size and the bits being compared are in the same position
4832 then we can do this by masking both and comparing the masked
4834 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
4835 lr_mask
= const_binop (BIT_IOR_EXPR
, lr_mask
, rr_mask
, 0);
4836 if (lnbitsize
== rnbitsize
&& xll_bitpos
== xlr_bitpos
)
4838 lhs
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
4839 ll_unsignedp
|| rl_unsignedp
);
4840 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
4841 lhs
= build2 (BIT_AND_EXPR
, lntype
, lhs
, ll_mask
);
4843 rhs
= make_bit_field_ref (lr_inner
, rntype
, rnbitsize
, rnbitpos
,
4844 lr_unsignedp
|| rr_unsignedp
);
4845 if (! all_ones_mask_p (lr_mask
, rnbitsize
))
4846 rhs
= build2 (BIT_AND_EXPR
, rntype
, rhs
, lr_mask
);
4848 return build2 (wanted_code
, truth_type
, lhs
, rhs
);
4851 /* There is still another way we can do something: If both pairs of
4852 fields being compared are adjacent, we may be able to make a wider
4853 field containing them both.
4855 Note that we still must mask the lhs/rhs expressions. Furthermore,
4856 the mask must be shifted to account for the shift done by
4857 make_bit_field_ref. */
4858 if ((ll_bitsize
+ ll_bitpos
== rl_bitpos
4859 && lr_bitsize
+ lr_bitpos
== rr_bitpos
)
4860 || (ll_bitpos
== rl_bitpos
+ rl_bitsize
4861 && lr_bitpos
== rr_bitpos
+ rr_bitsize
))
4865 lhs
= make_bit_field_ref (ll_inner
, lntype
, ll_bitsize
+ rl_bitsize
,
4866 MIN (ll_bitpos
, rl_bitpos
), ll_unsignedp
);
4867 rhs
= make_bit_field_ref (lr_inner
, rntype
, lr_bitsize
+ rr_bitsize
,
4868 MIN (lr_bitpos
, rr_bitpos
), lr_unsignedp
);
4870 ll_mask
= const_binop (RSHIFT_EXPR
, ll_mask
,
4871 size_int (MIN (xll_bitpos
, xrl_bitpos
)), 0);
4872 lr_mask
= const_binop (RSHIFT_EXPR
, lr_mask
,
4873 size_int (MIN (xlr_bitpos
, xrr_bitpos
)), 0);
4875 /* Convert to the smaller type before masking out unwanted bits. */
4877 if (lntype
!= rntype
)
4879 if (lnbitsize
> rnbitsize
)
4881 lhs
= fold_convert (rntype
, lhs
);
4882 ll_mask
= fold_convert (rntype
, ll_mask
);
4885 else if (lnbitsize
< rnbitsize
)
4887 rhs
= fold_convert (lntype
, rhs
);
4888 lr_mask
= fold_convert (lntype
, lr_mask
);
4893 if (! all_ones_mask_p (ll_mask
, ll_bitsize
+ rl_bitsize
))
4894 lhs
= build2 (BIT_AND_EXPR
, type
, lhs
, ll_mask
);
4896 if (! all_ones_mask_p (lr_mask
, lr_bitsize
+ rr_bitsize
))
4897 rhs
= build2 (BIT_AND_EXPR
, type
, rhs
, lr_mask
);
4899 return build2 (wanted_code
, truth_type
, lhs
, rhs
);
4905 /* Handle the case of comparisons with constants. If there is something in
4906 common between the masks, those bits of the constants must be the same.
4907 If not, the condition is always false. Test for this to avoid generating
4908 incorrect code below. */
4909 result
= const_binop (BIT_AND_EXPR
, ll_mask
, rl_mask
, 0);
4910 if (! integer_zerop (result
)
4911 && simple_cst_equal (const_binop (BIT_AND_EXPR
, result
, l_const
, 0),
4912 const_binop (BIT_AND_EXPR
, result
, r_const
, 0)) != 1)
4914 if (wanted_code
== NE_EXPR
)
4916 warning ("%<or%> of unmatched not-equal tests is always 1");
4917 return constant_boolean_node (true, truth_type
);
4921 warning ("%<and%> of mutually exclusive equal-tests is always 0");
4922 return constant_boolean_node (false, truth_type
);
4926 /* Construct the expression we will return. First get the component
4927 reference we will make. Unless the mask is all ones the width of
4928 that field, perform the mask operation. Then compare with the
4930 result
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
4931 ll_unsignedp
|| rl_unsignedp
);
4933 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
4934 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
4935 result
= build2 (BIT_AND_EXPR
, lntype
, result
, ll_mask
);
4937 return build2 (wanted_code
, truth_type
, result
,
4938 const_binop (BIT_IOR_EXPR
, l_const
, r_const
, 0));
4941 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4945 optimize_minmax_comparison (tree t
)
4947 tree type
= TREE_TYPE (t
);
4948 tree arg0
= TREE_OPERAND (t
, 0);
4949 enum tree_code op_code
;
4950 tree comp_const
= TREE_OPERAND (t
, 1);
4952 int consts_equal
, consts_lt
;
4955 STRIP_SIGN_NOPS (arg0
);
4957 op_code
= TREE_CODE (arg0
);
4958 minmax_const
= TREE_OPERAND (arg0
, 1);
4959 consts_equal
= tree_int_cst_equal (minmax_const
, comp_const
);
4960 consts_lt
= tree_int_cst_lt (minmax_const
, comp_const
);
4961 inner
= TREE_OPERAND (arg0
, 0);
4963 /* If something does not permit us to optimize, return the original tree. */
4964 if ((op_code
!= MIN_EXPR
&& op_code
!= MAX_EXPR
)
4965 || TREE_CODE (comp_const
) != INTEGER_CST
4966 || TREE_CONSTANT_OVERFLOW (comp_const
)
4967 || TREE_CODE (minmax_const
) != INTEGER_CST
4968 || TREE_CONSTANT_OVERFLOW (minmax_const
))
4971 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4972 and GT_EXPR, doing the rest with recursive calls using logical
4974 switch (TREE_CODE (t
))
4976 case NE_EXPR
: case LT_EXPR
: case LE_EXPR
:
4978 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t
)));
4982 fold (build2 (TRUTH_ORIF_EXPR
, type
,
4983 optimize_minmax_comparison
4984 (build2 (EQ_EXPR
, type
, arg0
, comp_const
)),
4985 optimize_minmax_comparison
4986 (build2 (GT_EXPR
, type
, arg0
, comp_const
))));
4989 if (op_code
== MAX_EXPR
&& consts_equal
)
4990 /* MAX (X, 0) == 0 -> X <= 0 */
4991 return fold (build2 (LE_EXPR
, type
, inner
, comp_const
));
4993 else if (op_code
== MAX_EXPR
&& consts_lt
)
4994 /* MAX (X, 0) == 5 -> X == 5 */
4995 return fold (build2 (EQ_EXPR
, type
, inner
, comp_const
));
4997 else if (op_code
== MAX_EXPR
)
4998 /* MAX (X, 0) == -1 -> false */
4999 return omit_one_operand (type
, integer_zero_node
, inner
);
5001 else if (consts_equal
)
5002 /* MIN (X, 0) == 0 -> X >= 0 */
5003 return fold (build2 (GE_EXPR
, type
, inner
, comp_const
));
5006 /* MIN (X, 0) == 5 -> false */
5007 return omit_one_operand (type
, integer_zero_node
, inner
);
5010 /* MIN (X, 0) == -1 -> X == -1 */
5011 return fold (build2 (EQ_EXPR
, type
, inner
, comp_const
));
5014 if (op_code
== MAX_EXPR
&& (consts_equal
|| consts_lt
))
5015 /* MAX (X, 0) > 0 -> X > 0
5016 MAX (X, 0) > 5 -> X > 5 */
5017 return fold (build2 (GT_EXPR
, type
, inner
, comp_const
));
5019 else if (op_code
== MAX_EXPR
)
5020 /* MAX (X, 0) > -1 -> true */
5021 return omit_one_operand (type
, integer_one_node
, inner
);
5023 else if (op_code
== MIN_EXPR
&& (consts_equal
|| consts_lt
))
5024 /* MIN (X, 0) > 0 -> false
5025 MIN (X, 0) > 5 -> false */
5026 return omit_one_operand (type
, integer_zero_node
, inner
);
5029 /* MIN (X, 0) > -1 -> X > -1 */
5030 return fold (build2 (GT_EXPR
, type
, inner
, comp_const
));
5037 /* T is an integer expression that is being multiplied, divided, or taken a
5038 modulus (CODE says which and what kind of divide or modulus) by a
5039 constant C. See if we can eliminate that operation by folding it with
5040 other operations already in T. WIDE_TYPE, if non-null, is a type that
5041 should be used for the computation if wider than our type.
5043 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5044 (X * 2) + (Y * 4). We must, however, be assured that either the original
5045 expression would not overflow or that overflow is undefined for the type
5046 in the language in question.
5048 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5049 the machine has a multiply-accumulate insn or that this is part of an
5050 addressing calculation.
5052 If we return a non-null expression, it is an equivalent form of the
5053 original computation, but need not be in the original type. */
5056 extract_muldiv (tree t
, tree c
, enum tree_code code
, tree wide_type
)
5058 /* To avoid exponential search depth, refuse to allow recursion past
5059 three levels. Beyond that (1) it's highly unlikely that we'll find
5060 something interesting and (2) we've probably processed it before
5061 when we built the inner expression. */
5070 ret
= extract_muldiv_1 (t
, c
, code
, wide_type
);
5077 extract_muldiv_1 (tree t
, tree c
, enum tree_code code
, tree wide_type
)
5079 tree type
= TREE_TYPE (t
);
5080 enum tree_code tcode
= TREE_CODE (t
);
5081 tree ctype
= (wide_type
!= 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type
))
5082 > GET_MODE_SIZE (TYPE_MODE (type
)))
5083 ? wide_type
: type
);
5085 int same_p
= tcode
== code
;
5086 tree op0
= NULL_TREE
, op1
= NULL_TREE
;
5088 /* Don't deal with constants of zero here; they confuse the code below. */
5089 if (integer_zerop (c
))
5092 if (TREE_CODE_CLASS (tcode
) == tcc_unary
)
5093 op0
= TREE_OPERAND (t
, 0);
5095 if (TREE_CODE_CLASS (tcode
) == tcc_binary
)
5096 op0
= TREE_OPERAND (t
, 0), op1
= TREE_OPERAND (t
, 1);
5098 /* Note that we need not handle conditional operations here since fold
5099 already handles those cases. So just do arithmetic here. */
5103 /* For a constant, we can always simplify if we are a multiply
5104 or (for divide and modulus) if it is a multiple of our constant. */
5105 if (code
== MULT_EXPR
5106 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, t
, c
, 0)))
5107 return const_binop (code
, fold_convert (ctype
, t
),
5108 fold_convert (ctype
, c
), 0);
5111 case CONVERT_EXPR
: case NON_LVALUE_EXPR
: case NOP_EXPR
:
5112 /* If op0 is an expression ... */
5113 if ((COMPARISON_CLASS_P (op0
)
5114 || UNARY_CLASS_P (op0
)
5115 || BINARY_CLASS_P (op0
)
5116 || EXPRESSION_CLASS_P (op0
))
5117 /* ... and is unsigned, and its type is smaller than ctype,
5118 then we cannot pass through as widening. */
5119 && ((TYPE_UNSIGNED (TREE_TYPE (op0
))
5120 && ! (TREE_CODE (TREE_TYPE (op0
)) == INTEGER_TYPE
5121 && TYPE_IS_SIZETYPE (TREE_TYPE (op0
)))
5122 && (GET_MODE_SIZE (TYPE_MODE (ctype
))
5123 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
)))))
5124 /* ... or this is a truncation (t is narrower than op0),
5125 then we cannot pass through this narrowing. */
5126 || (GET_MODE_SIZE (TYPE_MODE (type
))
5127 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
))))
5128 /* ... or signedness changes for division or modulus,
5129 then we cannot pass through this conversion. */
5130 || (code
!= MULT_EXPR
5131 && (TYPE_UNSIGNED (ctype
)
5132 != TYPE_UNSIGNED (TREE_TYPE (op0
))))))
5135 /* Pass the constant down and see if we can make a simplification. If
5136 we can, replace this expression with the inner simplification for
5137 possible later conversion to our or some other type. */
5138 if ((t2
= fold_convert (TREE_TYPE (op0
), c
)) != 0
5139 && TREE_CODE (t2
) == INTEGER_CST
5140 && ! TREE_CONSTANT_OVERFLOW (t2
)
5141 && (0 != (t1
= extract_muldiv (op0
, t2
, code
,
5143 ? ctype
: NULL_TREE
))))
5147 case NEGATE_EXPR
: case ABS_EXPR
:
5148 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
5149 return fold (build1 (tcode
, ctype
, fold_convert (ctype
, t1
)));
5152 case MIN_EXPR
: case MAX_EXPR
:
5153 /* If widening the type changes the signedness, then we can't perform
5154 this optimization as that changes the result. */
5155 if (TYPE_UNSIGNED (ctype
) != TYPE_UNSIGNED (type
))
5158 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5159 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0
5160 && (t2
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
5162 if (tree_int_cst_sgn (c
) < 0)
5163 tcode
= (tcode
== MIN_EXPR
? MAX_EXPR
: MIN_EXPR
);
5165 return fold (build2 (tcode
, ctype
, fold_convert (ctype
, t1
),
5166 fold_convert (ctype
, t2
)));
5170 case LSHIFT_EXPR
: case RSHIFT_EXPR
:
5171 /* If the second operand is constant, this is a multiplication
5172 or floor division, by a power of two, so we can treat it that
5173 way unless the multiplier or divisor overflows. Signed
5174 left-shift overflow is implementation-defined rather than
5175 undefined in C90, so do not convert signed left shift into
5177 if (TREE_CODE (op1
) == INTEGER_CST
5178 && (tcode
== RSHIFT_EXPR
|| TYPE_UNSIGNED (TREE_TYPE (op0
)))
5179 /* const_binop may not detect overflow correctly,
5180 so check for it explicitly here. */
5181 && TYPE_PRECISION (TREE_TYPE (size_one_node
)) > TREE_INT_CST_LOW (op1
)
5182 && TREE_INT_CST_HIGH (op1
) == 0
5183 && 0 != (t1
= fold_convert (ctype
,
5184 const_binop (LSHIFT_EXPR
,
5187 && ! TREE_OVERFLOW (t1
))
5188 return extract_muldiv (build2 (tcode
== LSHIFT_EXPR
5189 ? MULT_EXPR
: FLOOR_DIV_EXPR
,
5190 ctype
, fold_convert (ctype
, op0
), t1
),
5191 c
, code
, wide_type
);
5194 case PLUS_EXPR
: case MINUS_EXPR
:
5195 /* See if we can eliminate the operation on both sides. If we can, we
5196 can return a new PLUS or MINUS. If we can't, the only remaining
5197 cases where we can do anything are if the second operand is a
5199 t1
= extract_muldiv (op0
, c
, code
, wide_type
);
5200 t2
= extract_muldiv (op1
, c
, code
, wide_type
);
5201 if (t1
!= 0 && t2
!= 0
5202 && (code
== MULT_EXPR
5203 /* If not multiplication, we can only do this if both operands
5204 are divisible by c. */
5205 || (multiple_of_p (ctype
, op0
, c
)
5206 && multiple_of_p (ctype
, op1
, c
))))
5207 return fold (build2 (tcode
, ctype
, fold_convert (ctype
, t1
),
5208 fold_convert (ctype
, t2
)));
5210 /* If this was a subtraction, negate OP1 and set it to be an addition.
5211 This simplifies the logic below. */
5212 if (tcode
== MINUS_EXPR
)
5213 tcode
= PLUS_EXPR
, op1
= negate_expr (op1
);
5215 if (TREE_CODE (op1
) != INTEGER_CST
)
5218 /* If either OP1 or C are negative, this optimization is not safe for
5219 some of the division and remainder types while for others we need
5220 to change the code. */
5221 if (tree_int_cst_sgn (op1
) < 0 || tree_int_cst_sgn (c
) < 0)
5223 if (code
== CEIL_DIV_EXPR
)
5224 code
= FLOOR_DIV_EXPR
;
5225 else if (code
== FLOOR_DIV_EXPR
)
5226 code
= CEIL_DIV_EXPR
;
5227 else if (code
!= MULT_EXPR
5228 && code
!= CEIL_MOD_EXPR
&& code
!= FLOOR_MOD_EXPR
)
5232 /* If it's a multiply or a division/modulus operation of a multiple
5233 of our constant, do the operation and verify it doesn't overflow. */
5234 if (code
== MULT_EXPR
5235 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
5237 op1
= const_binop (code
, fold_convert (ctype
, op1
),
5238 fold_convert (ctype
, c
), 0);
5239 /* We allow the constant to overflow with wrapping semantics. */
5241 || (TREE_OVERFLOW (op1
) && ! flag_wrapv
))
5247 /* If we have an unsigned type is not a sizetype, we cannot widen
5248 the operation since it will change the result if the original
5249 computation overflowed. */
5250 if (TYPE_UNSIGNED (ctype
)
5251 && ! (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
))
5255 /* If we were able to eliminate our operation from the first side,
5256 apply our operation to the second side and reform the PLUS. */
5257 if (t1
!= 0 && (TREE_CODE (t1
) != code
|| code
== MULT_EXPR
))
5258 return fold (build2 (tcode
, ctype
, fold_convert (ctype
, t1
), op1
));
5260 /* The last case is if we are a multiply. In that case, we can
5261 apply the distributive law to commute the multiply and addition
5262 if the multiplication of the constants doesn't overflow. */
5263 if (code
== MULT_EXPR
)
5264 return fold (build2 (tcode
, ctype
,
5265 fold (build2 (code
, ctype
,
5266 fold_convert (ctype
, op0
),
5267 fold_convert (ctype
, c
))),
5273 /* We have a special case here if we are doing something like
5274 (C * 8) % 4 since we know that's zero. */
5275 if ((code
== TRUNC_MOD_EXPR
|| code
== CEIL_MOD_EXPR
5276 || code
== FLOOR_MOD_EXPR
|| code
== ROUND_MOD_EXPR
)
5277 && TREE_CODE (TREE_OPERAND (t
, 1)) == INTEGER_CST
5278 && integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
5279 return omit_one_operand (type
, integer_zero_node
, op0
);
5281 /* ... fall through ... */
5283 case TRUNC_DIV_EXPR
: case CEIL_DIV_EXPR
: case FLOOR_DIV_EXPR
:
5284 case ROUND_DIV_EXPR
: case EXACT_DIV_EXPR
:
5285 /* If we can extract our operation from the LHS, do so and return a
5286 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5287 do something only if the second operand is a constant. */
5289 && (t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
5290 return fold (build2 (tcode
, ctype
, fold_convert (ctype
, t1
),
5291 fold_convert (ctype
, op1
)));
5292 else if (tcode
== MULT_EXPR
&& code
== MULT_EXPR
5293 && (t1
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
5294 return fold (build2 (tcode
, ctype
, fold_convert (ctype
, op0
),
5295 fold_convert (ctype
, t1
)));
5296 else if (TREE_CODE (op1
) != INTEGER_CST
)
5299 /* If these are the same operation types, we can associate them
5300 assuming no overflow. */
5302 && 0 != (t1
= const_binop (MULT_EXPR
, fold_convert (ctype
, op1
),
5303 fold_convert (ctype
, c
), 0))
5304 && ! TREE_OVERFLOW (t1
))
5305 return fold (build2 (tcode
, ctype
, fold_convert (ctype
, op0
), t1
));
5307 /* If these operations "cancel" each other, we have the main
5308 optimizations of this pass, which occur when either constant is a
5309 multiple of the other, in which case we replace this with either an
5310 operation or CODE or TCODE.
5312 If we have an unsigned type that is not a sizetype, we cannot do
5313 this since it will change the result if the original computation
5315 if ((! TYPE_UNSIGNED (ctype
)
5316 || (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
)))
5318 && ((code
== MULT_EXPR
&& tcode
== EXACT_DIV_EXPR
)
5319 || (tcode
== MULT_EXPR
5320 && code
!= TRUNC_MOD_EXPR
&& code
!= CEIL_MOD_EXPR
5321 && code
!= FLOOR_MOD_EXPR
&& code
!= ROUND_MOD_EXPR
)))
5323 if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
5324 return fold (build2 (tcode
, ctype
, fold_convert (ctype
, op0
),
5325 fold_convert (ctype
,
5326 const_binop (TRUNC_DIV_EXPR
,
5328 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, c
, op1
, 0)))
5329 return fold (build2 (code
, ctype
, fold_convert (ctype
, op0
),
5330 fold_convert (ctype
,
5331 const_binop (TRUNC_DIV_EXPR
,
5343 /* Return a node which has the indicated constant VALUE (either 0 or
5344 1), and is of the indicated TYPE. */
5347 constant_boolean_node (int value
, tree type
)
5349 if (type
== integer_type_node
)
5350 return value
? integer_one_node
: integer_zero_node
;
5351 else if (type
== boolean_type_node
)
5352 return value
? boolean_true_node
: boolean_false_node
;
5353 else if (TREE_CODE (type
) == BOOLEAN_TYPE
)
5354 return lang_hooks
.truthvalue_conversion (value
? integer_one_node
5355 : integer_zero_node
);
5357 return build_int_cst (type
, value
);
5360 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
5361 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
5362 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
5363 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
5364 COND is the first argument to CODE; otherwise (as in the example
5365 given here), it is the second argument. TYPE is the type of the
5366 original expression. Return NULL_TREE if no simplification is
5370 fold_binary_op_with_conditional_arg (enum tree_code code
, tree type
,
5371 tree cond
, tree arg
, int cond_first_p
)
5373 tree test
, true_value
, false_value
;
5374 tree lhs
= NULL_TREE
;
5375 tree rhs
= NULL_TREE
;
5377 /* This transformation is only worthwhile if we don't have to wrap
5378 arg in a SAVE_EXPR, and the operation can be simplified on atleast
5379 one of the branches once its pushed inside the COND_EXPR. */
5380 if (!TREE_CONSTANT (arg
))
5383 if (TREE_CODE (cond
) == COND_EXPR
)
5385 test
= TREE_OPERAND (cond
, 0);
5386 true_value
= TREE_OPERAND (cond
, 1);
5387 false_value
= TREE_OPERAND (cond
, 2);
5388 /* If this operand throws an expression, then it does not make
5389 sense to try to perform a logical or arithmetic operation
5391 if (VOID_TYPE_P (TREE_TYPE (true_value
)))
5393 if (VOID_TYPE_P (TREE_TYPE (false_value
)))
5398 tree testtype
= TREE_TYPE (cond
);
5400 true_value
= constant_boolean_node (true, testtype
);
5401 false_value
= constant_boolean_node (false, testtype
);
5405 lhs
= fold (cond_first_p
? build2 (code
, type
, true_value
, arg
)
5406 : build2 (code
, type
, arg
, true_value
));
5408 rhs
= fold (cond_first_p
? build2 (code
, type
, false_value
, arg
)
5409 : build2 (code
, type
, arg
, false_value
));
5411 test
= fold (build3 (COND_EXPR
, type
, test
, lhs
, rhs
));
5412 return fold_convert (type
, test
);
5416 /* Subroutine of fold() that checks for the addition of +/- 0.0.
5418 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
5419 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
5420 ADDEND is the same as X.
5422 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
5423 and finite. The problematic cases are when X is zero, and its mode
5424 has signed zeros. In the case of rounding towards -infinity,
5425 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
5426 modes, X + 0 is not the same as X because -0 + 0 is 0. */
5429 fold_real_zero_addition_p (tree type
, tree addend
, int negate
)
5431 if (!real_zerop (addend
))
5434 /* Don't allow the fold with -fsignaling-nans. */
5435 if (HONOR_SNANS (TYPE_MODE (type
)))
5438 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
5439 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type
)))
5442 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
5443 if (TREE_CODE (addend
) == REAL_CST
5444 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend
)))
5447 /* The mode has signed zeros, and we have to honor their sign.
5448 In this situation, there is only one case we can return true for.
5449 X - 0 is the same as X unless rounding towards -infinity is
5451 return negate
&& !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type
));
5454 /* Subroutine of fold() that checks comparisons of built-in math
5455 functions against real constants.
5457 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
5458 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
5459 is the type of the result and ARG0 and ARG1 are the operands of the
5460 comparison. ARG1 must be a TREE_REAL_CST.
5462 The function returns the constant folded tree if a simplification
5463 can be made, and NULL_TREE otherwise. */
5466 fold_mathfn_compare (enum built_in_function fcode
, enum tree_code code
,
5467 tree type
, tree arg0
, tree arg1
)
5471 if (BUILTIN_SQRT_P (fcode
))
5473 tree arg
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
5474 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (arg0
));
5476 c
= TREE_REAL_CST (arg1
);
5477 if (REAL_VALUE_NEGATIVE (c
))
5479 /* sqrt(x) < y is always false, if y is negative. */
5480 if (code
== EQ_EXPR
|| code
== LT_EXPR
|| code
== LE_EXPR
)
5481 return omit_one_operand (type
, integer_zero_node
, arg
);
5483 /* sqrt(x) > y is always true, if y is negative and we
5484 don't care about NaNs, i.e. negative values of x. */
5485 if (code
== NE_EXPR
|| !HONOR_NANS (mode
))
5486 return omit_one_operand (type
, integer_one_node
, arg
);
5488 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
5489 return fold (build2 (GE_EXPR
, type
, arg
,
5490 build_real (TREE_TYPE (arg
), dconst0
)));
5492 else if (code
== GT_EXPR
|| code
== GE_EXPR
)
5496 REAL_ARITHMETIC (c2
, MULT_EXPR
, c
, c
);
5497 real_convert (&c2
, mode
, &c2
);
5499 if (REAL_VALUE_ISINF (c2
))
5501 /* sqrt(x) > y is x == +Inf, when y is very large. */
5502 if (HONOR_INFINITIES (mode
))
5503 return fold (build2 (EQ_EXPR
, type
, arg
,
5504 build_real (TREE_TYPE (arg
), c2
)));
5506 /* sqrt(x) > y is always false, when y is very large
5507 and we don't care about infinities. */
5508 return omit_one_operand (type
, integer_zero_node
, arg
);
5511 /* sqrt(x) > c is the same as x > c*c. */
5512 return fold (build2 (code
, type
, arg
,
5513 build_real (TREE_TYPE (arg
), c2
)));
5515 else if (code
== LT_EXPR
|| code
== LE_EXPR
)
5519 REAL_ARITHMETIC (c2
, MULT_EXPR
, c
, c
);
5520 real_convert (&c2
, mode
, &c2
);
5522 if (REAL_VALUE_ISINF (c2
))
5524 /* sqrt(x) < y is always true, when y is a very large
5525 value and we don't care about NaNs or Infinities. */
5526 if (! HONOR_NANS (mode
) && ! HONOR_INFINITIES (mode
))
5527 return omit_one_operand (type
, integer_one_node
, arg
);
5529 /* sqrt(x) < y is x != +Inf when y is very large and we
5530 don't care about NaNs. */
5531 if (! HONOR_NANS (mode
))
5532 return fold (build2 (NE_EXPR
, type
, arg
,
5533 build_real (TREE_TYPE (arg
), c2
)));
5535 /* sqrt(x) < y is x >= 0 when y is very large and we
5536 don't care about Infinities. */
5537 if (! HONOR_INFINITIES (mode
))
5538 return fold (build2 (GE_EXPR
, type
, arg
,
5539 build_real (TREE_TYPE (arg
), dconst0
)));
5541 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
5542 if (lang_hooks
.decls
.global_bindings_p () != 0
5543 || CONTAINS_PLACEHOLDER_P (arg
))
5546 arg
= save_expr (arg
);
5547 return fold (build2 (TRUTH_ANDIF_EXPR
, type
,
5548 fold (build2 (GE_EXPR
, type
, arg
,
5549 build_real (TREE_TYPE (arg
),
5551 fold (build2 (NE_EXPR
, type
, arg
,
5552 build_real (TREE_TYPE (arg
),
5556 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
5557 if (! HONOR_NANS (mode
))
5558 return fold (build2 (code
, type
, arg
,
5559 build_real (TREE_TYPE (arg
), c2
)));
5561 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
5562 if (lang_hooks
.decls
.global_bindings_p () == 0
5563 && ! CONTAINS_PLACEHOLDER_P (arg
))
5565 arg
= save_expr (arg
);
5566 return fold (build2 (TRUTH_ANDIF_EXPR
, type
,
5567 fold (build2 (GE_EXPR
, type
, arg
,
5568 build_real (TREE_TYPE (arg
),
5570 fold (build2 (code
, type
, arg
,
5571 build_real (TREE_TYPE (arg
),
5580 /* Subroutine of fold() that optimizes comparisons against Infinities,
5581 either +Inf or -Inf.
5583 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5584 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5585 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5587 The function returns the constant folded tree if a simplification
5588 can be made, and NULL_TREE otherwise. */
5591 fold_inf_compare (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
5593 enum machine_mode mode
;
5594 REAL_VALUE_TYPE max
;
5598 mode
= TYPE_MODE (TREE_TYPE (arg0
));
5600 /* For negative infinity swap the sense of the comparison. */
5601 neg
= REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1
));
5603 code
= swap_tree_comparison (code
);
5608 /* x > +Inf is always false, if with ignore sNANs. */
5609 if (HONOR_SNANS (mode
))
5611 return omit_one_operand (type
, integer_zero_node
, arg0
);
5614 /* x <= +Inf is always true, if we don't case about NaNs. */
5615 if (! HONOR_NANS (mode
))
5616 return omit_one_operand (type
, integer_one_node
, arg0
);
5618 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
5619 if (lang_hooks
.decls
.global_bindings_p () == 0
5620 && ! CONTAINS_PLACEHOLDER_P (arg0
))
5622 arg0
= save_expr (arg0
);
5623 return fold (build2 (EQ_EXPR
, type
, arg0
, arg0
));
5629 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
5630 real_maxval (&max
, neg
, mode
);
5631 return fold (build2 (neg
? LT_EXPR
: GT_EXPR
, type
,
5632 arg0
, build_real (TREE_TYPE (arg0
), max
)));
5635 /* x < +Inf is always equal to x <= DBL_MAX. */
5636 real_maxval (&max
, neg
, mode
);
5637 return fold (build2 (neg
? GE_EXPR
: LE_EXPR
, type
,
5638 arg0
, build_real (TREE_TYPE (arg0
), max
)));
5641 /* x != +Inf is always equal to !(x > DBL_MAX). */
5642 real_maxval (&max
, neg
, mode
);
5643 if (! HONOR_NANS (mode
))
5644 return fold (build2 (neg
? GE_EXPR
: LE_EXPR
, type
,
5645 arg0
, build_real (TREE_TYPE (arg0
), max
)));
5647 /* The transformation below creates non-gimple code and thus is
5648 not appropriate if we are in gimple form. */
5652 temp
= fold (build2 (neg
? LT_EXPR
: GT_EXPR
, type
,
5653 arg0
, build_real (TREE_TYPE (arg0
), max
)));
5654 return fold (build1 (TRUTH_NOT_EXPR
, type
, temp
));
5663 /* Subroutine of fold() that optimizes comparisons of a division by
5664 a nonzero integer constant against an integer constant, i.e.
5667 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5668 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5669 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5671 The function returns the constant folded tree if a simplification
5672 can be made, and NULL_TREE otherwise. */
5675 fold_div_compare (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
5677 tree prod
, tmp
, hi
, lo
;
5678 tree arg00
= TREE_OPERAND (arg0
, 0);
5679 tree arg01
= TREE_OPERAND (arg0
, 1);
5680 unsigned HOST_WIDE_INT lpart
;
5681 HOST_WIDE_INT hpart
;
5684 /* We have to do this the hard way to detect unsigned overflow.
5685 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
5686 overflow
= mul_double (TREE_INT_CST_LOW (arg01
),
5687 TREE_INT_CST_HIGH (arg01
),
5688 TREE_INT_CST_LOW (arg1
),
5689 TREE_INT_CST_HIGH (arg1
), &lpart
, &hpart
);
5690 prod
= build_int_cst_wide (TREE_TYPE (arg00
), lpart
, hpart
);
5691 prod
= force_fit_type (prod
, -1, overflow
, false);
5693 if (TYPE_UNSIGNED (TREE_TYPE (arg0
)))
5695 tmp
= int_const_binop (MINUS_EXPR
, arg01
, integer_one_node
, 0);
5698 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
5699 overflow
= add_double (TREE_INT_CST_LOW (prod
),
5700 TREE_INT_CST_HIGH (prod
),
5701 TREE_INT_CST_LOW (tmp
),
5702 TREE_INT_CST_HIGH (tmp
),
5704 hi
= build_int_cst_wide (TREE_TYPE (arg00
), lpart
, hpart
);
5705 hi
= force_fit_type (hi
, -1, overflow
| TREE_OVERFLOW (prod
),
5706 TREE_CONSTANT_OVERFLOW (prod
));
5708 else if (tree_int_cst_sgn (arg01
) >= 0)
5710 tmp
= int_const_binop (MINUS_EXPR
, arg01
, integer_one_node
, 0);
5711 switch (tree_int_cst_sgn (arg1
))
5714 lo
= int_const_binop (MINUS_EXPR
, prod
, tmp
, 0);
5719 lo
= fold_negate_const (tmp
, TREE_TYPE (arg0
));
5724 hi
= int_const_binop (PLUS_EXPR
, prod
, tmp
, 0);
5734 /* A negative divisor reverses the relational operators. */
5735 code
= swap_tree_comparison (code
);
5737 tmp
= int_const_binop (PLUS_EXPR
, arg01
, integer_one_node
, 0);
5738 switch (tree_int_cst_sgn (arg1
))
5741 hi
= int_const_binop (MINUS_EXPR
, prod
, tmp
, 0);
5746 hi
= fold_negate_const (tmp
, TREE_TYPE (arg0
));
5751 lo
= int_const_binop (PLUS_EXPR
, prod
, tmp
, 0);
5763 if (TREE_OVERFLOW (lo
) && TREE_OVERFLOW (hi
))
5764 return omit_one_operand (type
, integer_zero_node
, arg00
);
5765 if (TREE_OVERFLOW (hi
))
5766 return fold (build2 (GE_EXPR
, type
, arg00
, lo
));
5767 if (TREE_OVERFLOW (lo
))
5768 return fold (build2 (LE_EXPR
, type
, arg00
, hi
));
5769 return build_range_check (type
, arg00
, 1, lo
, hi
);
5772 if (TREE_OVERFLOW (lo
) && TREE_OVERFLOW (hi
))
5773 return omit_one_operand (type
, integer_one_node
, arg00
);
5774 if (TREE_OVERFLOW (hi
))
5775 return fold (build2 (LT_EXPR
, type
, arg00
, lo
));
5776 if (TREE_OVERFLOW (lo
))
5777 return fold (build2 (GT_EXPR
, type
, arg00
, hi
));
5778 return build_range_check (type
, arg00
, 0, lo
, hi
);
5781 if (TREE_OVERFLOW (lo
))
5782 return omit_one_operand (type
, integer_zero_node
, arg00
);
5783 return fold (build2 (LT_EXPR
, type
, arg00
, lo
));
5786 if (TREE_OVERFLOW (hi
))
5787 return omit_one_operand (type
, integer_one_node
, arg00
);
5788 return fold (build2 (LE_EXPR
, type
, arg00
, hi
));
5791 if (TREE_OVERFLOW (hi
))
5792 return omit_one_operand (type
, integer_zero_node
, arg00
);
5793 return fold (build2 (GT_EXPR
, type
, arg00
, hi
));
5796 if (TREE_OVERFLOW (lo
))
5797 return omit_one_operand (type
, integer_one_node
, arg00
);
5798 return fold (build2 (GE_EXPR
, type
, arg00
, lo
));
5808 /* If CODE with arguments ARG0 and ARG1 represents a single bit
5809 equality/inequality test, then return a simplified form of
5810 the test using shifts and logical operations. Otherwise return
5811 NULL. TYPE is the desired result type. */
5814 fold_single_bit_test (enum tree_code code
, tree arg0
, tree arg1
,
5817 /* If this is a TRUTH_NOT_EXPR, it may have a single bit test inside
5819 if (code
== TRUTH_NOT_EXPR
)
5821 code
= TREE_CODE (arg0
);
5822 if (code
!= NE_EXPR
&& code
!= EQ_EXPR
)
5825 /* Extract the arguments of the EQ/NE. */
5826 arg1
= TREE_OPERAND (arg0
, 1);
5827 arg0
= TREE_OPERAND (arg0
, 0);
5829 /* This requires us to invert the code. */
5830 code
= (code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
);
5833 /* If this is testing a single bit, we can optimize the test. */
5834 if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
5835 && TREE_CODE (arg0
) == BIT_AND_EXPR
&& integer_zerop (arg1
)
5836 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
5838 tree inner
= TREE_OPERAND (arg0
, 0);
5839 tree type
= TREE_TYPE (arg0
);
5840 int bitnum
= tree_log2 (TREE_OPERAND (arg0
, 1));
5841 enum machine_mode operand_mode
= TYPE_MODE (type
);
5843 tree signed_type
, unsigned_type
, intermediate_type
;
5846 /* If we have (A & C) != 0 where C is the sign bit of A, convert
5847 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
5848 arg00
= sign_bit_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg0
, 1));
5849 if (arg00
!= NULL_TREE
5850 /* This is only a win if casting to a signed type is cheap,
5851 i.e. when arg00's type is not a partial mode. */
5852 && TYPE_PRECISION (TREE_TYPE (arg00
))
5853 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00
))))
5855 tree stype
= lang_hooks
.types
.signed_type (TREE_TYPE (arg00
));
5856 return fold (build2 (code
== EQ_EXPR
? GE_EXPR
: LT_EXPR
,
5857 result_type
, fold_convert (stype
, arg00
),
5858 fold_convert (stype
, integer_zero_node
)));
5861 /* Otherwise we have (A & C) != 0 where C is a single bit,
5862 convert that into ((A >> C2) & 1). Where C2 = log2(C).
5863 Similarly for (A & C) == 0. */
5865 /* If INNER is a right shift of a constant and it plus BITNUM does
5866 not overflow, adjust BITNUM and INNER. */
5867 if (TREE_CODE (inner
) == RSHIFT_EXPR
5868 && TREE_CODE (TREE_OPERAND (inner
, 1)) == INTEGER_CST
5869 && TREE_INT_CST_HIGH (TREE_OPERAND (inner
, 1)) == 0
5870 && bitnum
< TYPE_PRECISION (type
)
5871 && 0 > compare_tree_int (TREE_OPERAND (inner
, 1),
5872 bitnum
- TYPE_PRECISION (type
)))
5874 bitnum
+= TREE_INT_CST_LOW (TREE_OPERAND (inner
, 1));
5875 inner
= TREE_OPERAND (inner
, 0);
5878 /* If we are going to be able to omit the AND below, we must do our
5879 operations as unsigned. If we must use the AND, we have a choice.
5880 Normally unsigned is faster, but for some machines signed is. */
5881 #ifdef LOAD_EXTEND_OP
5882 ops_unsigned
= (LOAD_EXTEND_OP (operand_mode
) == SIGN_EXTEND
? 0 : 1);
5887 signed_type
= lang_hooks
.types
.type_for_mode (operand_mode
, 0);
5888 unsigned_type
= lang_hooks
.types
.type_for_mode (operand_mode
, 1);
5889 intermediate_type
= ops_unsigned
? unsigned_type
: signed_type
;
5890 inner
= fold_convert (intermediate_type
, inner
);
5893 inner
= build2 (RSHIFT_EXPR
, intermediate_type
,
5894 inner
, size_int (bitnum
));
5896 if (code
== EQ_EXPR
)
5897 inner
= fold (build2 (BIT_XOR_EXPR
, intermediate_type
,
5898 inner
, integer_one_node
));
5900 /* Put the AND last so it can combine with more things. */
5901 inner
= build2 (BIT_AND_EXPR
, intermediate_type
,
5902 inner
, integer_one_node
);
5904 /* Make sure to return the proper type. */
5905 inner
= fold_convert (result_type
, inner
);
5912 /* Check whether we are allowed to reorder operands arg0 and arg1,
5913 such that the evaluation of arg1 occurs before arg0. */
5916 reorder_operands_p (tree arg0
, tree arg1
)
5918 if (! flag_evaluation_order
)
5920 if (TREE_CONSTANT (arg0
) || TREE_CONSTANT (arg1
))
5922 return ! TREE_SIDE_EFFECTS (arg0
)
5923 && ! TREE_SIDE_EFFECTS (arg1
);
5926 /* Test whether it is preferable two swap two operands, ARG0 and
5927 ARG1, for example because ARG0 is an integer constant and ARG1
5928 isn't. If REORDER is true, only recommend swapping if we can
5929 evaluate the operands in reverse order. */
5932 tree_swap_operands_p (tree arg0
, tree arg1
, bool reorder
)
5934 STRIP_SIGN_NOPS (arg0
);
5935 STRIP_SIGN_NOPS (arg1
);
5937 if (TREE_CODE (arg1
) == INTEGER_CST
)
5939 if (TREE_CODE (arg0
) == INTEGER_CST
)
5942 if (TREE_CODE (arg1
) == REAL_CST
)
5944 if (TREE_CODE (arg0
) == REAL_CST
)
5947 if (TREE_CODE (arg1
) == COMPLEX_CST
)
5949 if (TREE_CODE (arg0
) == COMPLEX_CST
)
5952 if (TREE_CONSTANT (arg1
))
5954 if (TREE_CONSTANT (arg0
))
5960 if (reorder
&& flag_evaluation_order
5961 && (TREE_SIDE_EFFECTS (arg0
) || TREE_SIDE_EFFECTS (arg1
)))
5969 /* It is preferable to swap two SSA_NAME to ensure a canonical form
5970 for commutative and comparison operators. Ensuring a canonical
5971 form allows the optimizers to find additional redundancies without
5972 having to explicitly check for both orderings. */
5973 if (TREE_CODE (arg0
) == SSA_NAME
5974 && TREE_CODE (arg1
) == SSA_NAME
5975 && SSA_NAME_VERSION (arg0
) > SSA_NAME_VERSION (arg1
))
5981 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
5982 ARG0 is extended to a wider type. */
5985 fold_widened_comparison (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
5987 tree arg0_unw
= get_unwidened (arg0
, NULL_TREE
);
5989 tree shorter_type
, outer_type
;
5993 if (arg0_unw
== arg0
)
5995 shorter_type
= TREE_TYPE (arg0_unw
);
5997 arg1_unw
= get_unwidened (arg1
, shorter_type
);
6001 /* If possible, express the comparison in the shorter mode. */
6002 if ((code
== EQ_EXPR
|| code
== NE_EXPR
6003 || TYPE_UNSIGNED (TREE_TYPE (arg0
)) == TYPE_UNSIGNED (shorter_type
))
6004 && (TREE_TYPE (arg1_unw
) == shorter_type
6005 || (TREE_CODE (arg1_unw
) == INTEGER_CST
6006 && int_fits_type_p (arg1_unw
, shorter_type
))))
6007 return fold (build (code
, type
, arg0_unw
,
6008 fold_convert (shorter_type
, arg1_unw
)));
6010 if (TREE_CODE (arg1_unw
) != INTEGER_CST
)
6013 /* If we are comparing with the integer that does not fit into the range
6014 of the shorter type, the result is known. */
6015 outer_type
= TREE_TYPE (arg1_unw
);
6016 min
= lower_bound_in_type (outer_type
, shorter_type
);
6017 max
= upper_bound_in_type (outer_type
, shorter_type
);
6019 above
= integer_nonzerop (fold_relational_const (LT_EXPR
, type
,
6021 below
= integer_nonzerop (fold_relational_const (LT_EXPR
, type
,
6028 return constant_boolean_node (false, type
);
6033 return constant_boolean_node (true, type
);
6039 return constant_boolean_node (true, type
);
6041 return constant_boolean_node (false, type
);;
6046 return constant_boolean_node (false, type
);
6048 return constant_boolean_node (true, type
);;
6057 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
6058 ARG0 just the signedness is changed. */
6061 fold_sign_changed_comparison (enum tree_code code
, tree type
,
6062 tree arg0
, tree arg1
)
6064 tree arg0_inner
, tmp
;
6065 tree inner_type
, outer_type
;
6067 if (TREE_CODE (arg0
) != NOP_EXPR
)
6070 outer_type
= TREE_TYPE (arg0
);
6071 arg0_inner
= TREE_OPERAND (arg0
, 0);
6072 inner_type
= TREE_TYPE (arg0_inner
);
6074 if (TYPE_PRECISION (inner_type
) != TYPE_PRECISION (outer_type
))
6077 if (TREE_CODE (arg1
) != INTEGER_CST
6078 && !(TREE_CODE (arg1
) == NOP_EXPR
6079 && TREE_TYPE (TREE_OPERAND (arg1
, 0)) == inner_type
))
6082 if (TYPE_UNSIGNED (inner_type
) != TYPE_UNSIGNED (outer_type
)
6087 if (TREE_CODE (arg1
) == INTEGER_CST
)
6089 tmp
= build_int_cst_wide (inner_type
,
6090 TREE_INT_CST_LOW (arg1
),
6091 TREE_INT_CST_HIGH (arg1
));
6092 arg1
= force_fit_type (tmp
, 0,
6093 TREE_OVERFLOW (arg1
),
6094 TREE_CONSTANT_OVERFLOW (arg1
));
6097 arg1
= fold_convert (inner_type
, arg1
);
6099 return fold (build (code
, type
, arg0_inner
, arg1
));
6102 /* Tries to replace &a[idx] CODE s * delta with &a[idx CODE delta], if s is
6103 step of the array. TYPE is the type of the expression. ADDR is the address.
6104 MULT is the multiplicative expression. If the function succeeds, the new
6105 address expression is returned. Otherwise NULL_TREE is returned. */
6108 try_move_mult_to_index (tree type
, enum tree_code code
, tree addr
, tree mult
)
6110 tree s
, delta
, step
;
6111 tree arg0
= TREE_OPERAND (mult
, 0), arg1
= TREE_OPERAND (mult
, 1);
6112 tree ref
= TREE_OPERAND (addr
, 0), pref
;
6119 if (TREE_CODE (arg0
) == INTEGER_CST
)
6124 else if (TREE_CODE (arg1
) == INTEGER_CST
)
6132 for (;; ref
= TREE_OPERAND (ref
, 0))
6134 if (TREE_CODE (ref
) == ARRAY_REF
)
6136 step
= array_ref_element_size (ref
);
6138 if (TREE_CODE (step
) != INTEGER_CST
)
6141 itype
= TREE_TYPE (step
);
6143 /* If the type sizes do not match, we might run into problems
6144 when one of them would overflow. */
6145 if (TYPE_PRECISION (itype
) != TYPE_PRECISION (type
))
6148 if (!operand_equal_p (step
, fold_convert (itype
, s
), 0))
6151 delta
= fold_convert (itype
, delta
);
6155 if (!handled_component_p (ref
))
6159 /* We found the suitable array reference. So copy everything up to it,
6160 and replace the index. */
6162 pref
= TREE_OPERAND (addr
, 0);
6163 ret
= copy_node (pref
);
6168 pref
= TREE_OPERAND (pref
, 0);
6169 TREE_OPERAND (pos
, 0) = copy_node (pref
);
6170 pos
= TREE_OPERAND (pos
, 0);
6173 TREE_OPERAND (pos
, 1) = fold (build2 (code
, itype
,
6174 TREE_OPERAND (pos
, 1),
6177 return build1 (ADDR_EXPR
, type
, ret
);
6181 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
6182 means A >= Y && A != MAX, but in this case we know that
6183 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
6186 fold_to_nonsharp_ineq_using_bound (tree ineq
, tree bound
)
6188 tree a
, typea
, type
= TREE_TYPE (ineq
), a1
, diff
, y
;
6190 if (TREE_CODE (bound
) == LT_EXPR
)
6191 a
= TREE_OPERAND (bound
, 0);
6192 else if (TREE_CODE (bound
) == GT_EXPR
)
6193 a
= TREE_OPERAND (bound
, 1);
6197 typea
= TREE_TYPE (a
);
6198 if (!INTEGRAL_TYPE_P (typea
)
6199 && !POINTER_TYPE_P (typea
))
6202 if (TREE_CODE (ineq
) == LT_EXPR
)
6204 a1
= TREE_OPERAND (ineq
, 1);
6205 y
= TREE_OPERAND (ineq
, 0);
6207 else if (TREE_CODE (ineq
) == GT_EXPR
)
6209 a1
= TREE_OPERAND (ineq
, 0);
6210 y
= TREE_OPERAND (ineq
, 1);
6215 if (TREE_TYPE (a1
) != typea
)
6218 diff
= fold (build2 (MINUS_EXPR
, typea
, a1
, a
));
6219 if (!integer_onep (diff
))
6222 return fold (build2 (GE_EXPR
, type
, a
, y
));
6225 /* Perform constant folding and related simplification of EXPR.
6226 The related simplifications include x*1 => x, x*0 => 0, etc.,
6227 and application of the associative law.
6228 NOP_EXPR conversions may be removed freely (as long as we
6229 are careful not to change the type of the overall expression).
6230 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
6231 but we can constant-fold them if they have constant operands. */
6233 #ifdef ENABLE_FOLD_CHECKING
6234 # define fold(x) fold_1 (x)
6235 static tree
fold_1 (tree
);
6241 const tree t
= expr
;
6242 const tree type
= TREE_TYPE (expr
);
6243 tree t1
= NULL_TREE
;
6245 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
;
6246 enum tree_code code
= TREE_CODE (t
);
6247 enum tree_code_class kind
= TREE_CODE_CLASS (code
);
6249 /* WINS will be nonzero when the switch is done
6250 if all operands are constant. */
6253 /* Return right away if a constant. */
6254 if (kind
== tcc_constant
)
6257 if (code
== NOP_EXPR
|| code
== FLOAT_EXPR
|| code
== CONVERT_EXPR
)
6261 /* Special case for conversion ops that can have fixed point args. */
6262 arg0
= TREE_OPERAND (t
, 0);
6264 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
6266 STRIP_SIGN_NOPS (arg0
);
6268 if (arg0
!= 0 && TREE_CODE (arg0
) == COMPLEX_CST
)
6269 subop
= TREE_REALPART (arg0
);
6273 if (subop
!= 0 && TREE_CODE (subop
) != INTEGER_CST
6274 && TREE_CODE (subop
) != REAL_CST
)
6275 /* Note that TREE_CONSTANT isn't enough:
6276 static var addresses are constant but we can't
6277 do arithmetic on them. */
6280 else if (IS_EXPR_CODE_CLASS (kind
))
6282 int len
= first_rtl_op (code
);
6284 for (i
= 0; i
< len
; i
++)
6286 tree op
= TREE_OPERAND (t
, i
);
6290 continue; /* Valid for CALL_EXPR, at least. */
6292 /* Strip any conversions that don't change the mode. This is
6293 safe for every expression, except for a comparison expression
6294 because its signedness is derived from its operands. So, in
6295 the latter case, only strip conversions that don't change the
6298 Note that this is done as an internal manipulation within the
6299 constant folder, in order to find the simplest representation
6300 of the arguments so that their form can be studied. In any
6301 cases, the appropriate type conversions should be put back in
6302 the tree that will get out of the constant folder. */
6303 if (kind
== tcc_comparison
)
6304 STRIP_SIGN_NOPS (op
);
6308 if (TREE_CODE (op
) == COMPLEX_CST
)
6309 subop
= TREE_REALPART (op
);
6313 if (TREE_CODE (subop
) != INTEGER_CST
6314 && TREE_CODE (subop
) != REAL_CST
)
6315 /* Note that TREE_CONSTANT isn't enough:
6316 static var addresses are constant but we can't
6317 do arithmetic on them. */
6327 /* If this is a commutative operation, and ARG0 is a constant, move it
6328 to ARG1 to reduce the number of tests below. */
6329 if (commutative_tree_code (code
)
6330 && tree_swap_operands_p (arg0
, arg1
, true))
6331 return fold (build2 (code
, type
, TREE_OPERAND (t
, 1),
6332 TREE_OPERAND (t
, 0)));
6334 /* Now WINS is set as described above,
6335 ARG0 is the first operand of EXPR,
6336 and ARG1 is the second operand (if it has more than one operand).
6338 First check for cases where an arithmetic operation is applied to a
6339 compound, conditional, or comparison operation. Push the arithmetic
6340 operation inside the compound or conditional to see if any folding
6341 can then be done. Convert comparison to conditional for this purpose.
6342 The also optimizes non-constant cases that used to be done in
6345 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
6346 one of the operands is a comparison and the other is a comparison, a
6347 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
6348 code below would make the expression more complex. Change it to a
6349 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
6350 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
6352 if ((code
== BIT_AND_EXPR
|| code
== BIT_IOR_EXPR
6353 || code
== EQ_EXPR
|| code
== NE_EXPR
)
6354 && ((truth_value_p (TREE_CODE (arg0
))
6355 && (truth_value_p (TREE_CODE (arg1
))
6356 || (TREE_CODE (arg1
) == BIT_AND_EXPR
6357 && integer_onep (TREE_OPERAND (arg1
, 1)))))
6358 || (truth_value_p (TREE_CODE (arg1
))
6359 && (truth_value_p (TREE_CODE (arg0
))
6360 || (TREE_CODE (arg0
) == BIT_AND_EXPR
6361 && integer_onep (TREE_OPERAND (arg0
, 1)))))))
6363 tem
= fold (build2 (code
== BIT_AND_EXPR
? TRUTH_AND_EXPR
6364 : code
== BIT_IOR_EXPR
? TRUTH_OR_EXPR
6366 type
, fold_convert (boolean_type_node
, arg0
),
6367 fold_convert (boolean_type_node
, arg1
)));
6369 if (code
== EQ_EXPR
)
6370 tem
= invert_truthvalue (tem
);
6375 if (TREE_CODE_CLASS (code
) == tcc_unary
)
6377 if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
6378 return build2 (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
6379 fold (build1 (code
, type
, TREE_OPERAND (arg0
, 1))));
6380 else if (TREE_CODE (arg0
) == COND_EXPR
)
6382 tree arg01
= TREE_OPERAND (arg0
, 1);
6383 tree arg02
= TREE_OPERAND (arg0
, 2);
6384 if (! VOID_TYPE_P (TREE_TYPE (arg01
)))
6385 arg01
= fold (build1 (code
, type
, arg01
));
6386 if (! VOID_TYPE_P (TREE_TYPE (arg02
)))
6387 arg02
= fold (build1 (code
, type
, arg02
));
6388 tem
= fold (build3 (COND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
6391 /* If this was a conversion, and all we did was to move into
6392 inside the COND_EXPR, bring it back out. But leave it if
6393 it is a conversion from integer to integer and the
6394 result precision is no wider than a word since such a
6395 conversion is cheap and may be optimized away by combine,
6396 while it couldn't if it were outside the COND_EXPR. Then return
6397 so we don't get into an infinite recursion loop taking the
6398 conversion out and then back in. */
6400 if ((code
== NOP_EXPR
|| code
== CONVERT_EXPR
6401 || code
== NON_LVALUE_EXPR
)
6402 && TREE_CODE (tem
) == COND_EXPR
6403 && TREE_CODE (TREE_OPERAND (tem
, 1)) == code
6404 && TREE_CODE (TREE_OPERAND (tem
, 2)) == code
6405 && ! VOID_TYPE_P (TREE_OPERAND (tem
, 1))
6406 && ! VOID_TYPE_P (TREE_OPERAND (tem
, 2))
6407 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem
, 1), 0))
6408 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem
, 2), 0)))
6409 && ! (INTEGRAL_TYPE_P (TREE_TYPE (tem
))
6411 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem
, 1), 0))))
6412 && TYPE_PRECISION (TREE_TYPE (tem
)) <= BITS_PER_WORD
))
6413 tem
= build1 (code
, type
,
6415 TREE_TYPE (TREE_OPERAND
6416 (TREE_OPERAND (tem
, 1), 0)),
6417 TREE_OPERAND (tem
, 0),
6418 TREE_OPERAND (TREE_OPERAND (tem
, 1), 0),
6419 TREE_OPERAND (TREE_OPERAND (tem
, 2), 0)));
6422 else if (COMPARISON_CLASS_P (arg0
))
6424 if (TREE_CODE (type
) == BOOLEAN_TYPE
)
6426 arg0
= copy_node (arg0
);
6427 TREE_TYPE (arg0
) = type
;
6430 else if (TREE_CODE (type
) != INTEGER_TYPE
)
6431 return fold (build3 (COND_EXPR
, type
, arg0
,
6432 fold (build1 (code
, type
,
6434 fold (build1 (code
, type
,
6435 integer_zero_node
))));
6438 else if (TREE_CODE_CLASS (code
) == tcc_comparison
6439 && TREE_CODE (arg0
) == COMPOUND_EXPR
)
6440 return build2 (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
6441 fold (build2 (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
6442 else if (TREE_CODE_CLASS (code
) == tcc_comparison
6443 && TREE_CODE (arg1
) == COMPOUND_EXPR
)
6444 return build2 (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
6445 fold (build2 (code
, type
, arg0
, TREE_OPERAND (arg1
, 1))));
6446 else if (TREE_CODE_CLASS (code
) == tcc_binary
6447 || TREE_CODE_CLASS (code
) == tcc_comparison
)
6449 if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
6450 return build2 (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
6451 fold (build2 (code
, type
, TREE_OPERAND (arg0
, 1),
6453 if (TREE_CODE (arg1
) == COMPOUND_EXPR
6454 && reorder_operands_p (arg0
, TREE_OPERAND (arg1
, 0)))
6455 return build2 (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
6456 fold (build2 (code
, type
,
6457 arg0
, TREE_OPERAND (arg1
, 1))));
6459 if (TREE_CODE (arg0
) == COND_EXPR
|| COMPARISON_CLASS_P (arg0
))
6461 tem
= fold_binary_op_with_conditional_arg (code
, type
, arg0
, arg1
,
6462 /*cond_first_p=*/1);
6463 if (tem
!= NULL_TREE
)
6467 if (TREE_CODE (arg1
) == COND_EXPR
|| COMPARISON_CLASS_P (arg1
))
6469 tem
= fold_binary_op_with_conditional_arg (code
, type
, arg1
, arg0
,
6470 /*cond_first_p=*/0);
6471 if (tem
!= NULL_TREE
)
6479 return fold (DECL_INITIAL (t
));
6484 case FIX_TRUNC_EXPR
:
6486 case FIX_FLOOR_EXPR
:
6487 case FIX_ROUND_EXPR
:
6488 if (TREE_TYPE (TREE_OPERAND (t
, 0)) == type
)
6489 return TREE_OPERAND (t
, 0);
6491 /* Handle cases of two conversions in a row. */
6492 if (TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
6493 || TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
)
6495 tree inside_type
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
6496 tree inter_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
6497 int inside_int
= INTEGRAL_TYPE_P (inside_type
);
6498 int inside_ptr
= POINTER_TYPE_P (inside_type
);
6499 int inside_float
= FLOAT_TYPE_P (inside_type
);
6500 unsigned int inside_prec
= TYPE_PRECISION (inside_type
);
6501 int inside_unsignedp
= TYPE_UNSIGNED (inside_type
);
6502 int inter_int
= INTEGRAL_TYPE_P (inter_type
);
6503 int inter_ptr
= POINTER_TYPE_P (inter_type
);
6504 int inter_float
= FLOAT_TYPE_P (inter_type
);
6505 unsigned int inter_prec
= TYPE_PRECISION (inter_type
);
6506 int inter_unsignedp
= TYPE_UNSIGNED (inter_type
);
6507 int final_int
= INTEGRAL_TYPE_P (type
);
6508 int final_ptr
= POINTER_TYPE_P (type
);
6509 int final_float
= FLOAT_TYPE_P (type
);
6510 unsigned int final_prec
= TYPE_PRECISION (type
);
6511 int final_unsignedp
= TYPE_UNSIGNED (type
);
6513 /* In addition to the cases of two conversions in a row
6514 handled below, if we are converting something to its own
6515 type via an object of identical or wider precision, neither
6516 conversion is needed. */
6517 if (TYPE_MAIN_VARIANT (inside_type
) == TYPE_MAIN_VARIANT (type
)
6518 && ((inter_int
&& final_int
) || (inter_float
&& final_float
))
6519 && inter_prec
>= final_prec
)
6520 return fold (build1 (code
, type
,
6521 TREE_OPERAND (TREE_OPERAND (t
, 0), 0)));
6523 /* Likewise, if the intermediate and final types are either both
6524 float or both integer, we don't need the middle conversion if
6525 it is wider than the final type and doesn't change the signedness
6526 (for integers). Avoid this if the final type is a pointer
6527 since then we sometimes need the inner conversion. Likewise if
6528 the outer has a precision not equal to the size of its mode. */
6529 if ((((inter_int
|| inter_ptr
) && (inside_int
|| inside_ptr
))
6530 || (inter_float
&& inside_float
))
6531 && inter_prec
>= inside_prec
6532 && (inter_float
|| inter_unsignedp
== inside_unsignedp
)
6533 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (type
))
6534 && TYPE_MODE (type
) == TYPE_MODE (inter_type
))
6536 return fold (build1 (code
, type
,
6537 TREE_OPERAND (TREE_OPERAND (t
, 0), 0)));
6539 /* If we have a sign-extension of a zero-extended value, we can
6540 replace that by a single zero-extension. */
6541 if (inside_int
&& inter_int
&& final_int
6542 && inside_prec
< inter_prec
&& inter_prec
< final_prec
6543 && inside_unsignedp
&& !inter_unsignedp
)
6544 return fold (build1 (code
, type
,
6545 TREE_OPERAND (TREE_OPERAND (t
, 0), 0)));
6547 /* Two conversions in a row are not needed unless:
6548 - some conversion is floating-point (overstrict for now), or
6549 - the intermediate type is narrower than both initial and
6551 - the intermediate type and innermost type differ in signedness,
6552 and the outermost type is wider than the intermediate, or
6553 - the initial type is a pointer type and the precisions of the
6554 intermediate and final types differ, or
6555 - the final type is a pointer type and the precisions of the
6556 initial and intermediate types differ. */
6557 if (! inside_float
&& ! inter_float
&& ! final_float
6558 && (inter_prec
> inside_prec
|| inter_prec
> final_prec
)
6559 && ! (inside_int
&& inter_int
6560 && inter_unsignedp
!= inside_unsignedp
6561 && inter_prec
< final_prec
)
6562 && ((inter_unsignedp
&& inter_prec
> inside_prec
)
6563 == (final_unsignedp
&& final_prec
> inter_prec
))
6564 && ! (inside_ptr
&& inter_prec
!= final_prec
)
6565 && ! (final_ptr
&& inside_prec
!= inter_prec
)
6566 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (type
))
6567 && TYPE_MODE (type
) == TYPE_MODE (inter_type
))
6569 return fold (build1 (code
, type
,
6570 TREE_OPERAND (TREE_OPERAND (t
, 0), 0)));
6573 if (TREE_CODE (TREE_OPERAND (t
, 0)) == MODIFY_EXPR
6574 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t
, 0), 1))
6575 /* Detect assigning a bitfield. */
6576 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0)) == COMPONENT_REF
6577 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t
, 0), 0), 1))))
6579 /* Don't leave an assignment inside a conversion
6580 unless assigning a bitfield. */
6581 tree prev
= TREE_OPERAND (t
, 0);
6582 tem
= copy_node (t
);
6583 TREE_OPERAND (tem
, 0) = TREE_OPERAND (prev
, 1);
6584 /* First do the assignment, then return converted constant. */
6585 tem
= build2 (COMPOUND_EXPR
, TREE_TYPE (tem
), prev
, fold (tem
));
6586 TREE_NO_WARNING (tem
) = 1;
6587 TREE_USED (tem
) = 1;
6591 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
6592 constants (if x has signed type, the sign bit cannot be set
6593 in c). This folds extension into the BIT_AND_EXPR. */
6594 if (INTEGRAL_TYPE_P (type
)
6595 && TREE_CODE (type
) != BOOLEAN_TYPE
6596 && TREE_CODE (TREE_OPERAND (t
, 0)) == BIT_AND_EXPR
6597 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 1)) == INTEGER_CST
)
6599 tree
and = TREE_OPERAND (t
, 0);
6600 tree and0
= TREE_OPERAND (and, 0), and1
= TREE_OPERAND (and, 1);
6603 if (TYPE_UNSIGNED (TREE_TYPE (and))
6604 || (TYPE_PRECISION (type
)
6605 <= TYPE_PRECISION (TREE_TYPE (and))))
6607 else if (TYPE_PRECISION (TREE_TYPE (and1
))
6608 <= HOST_BITS_PER_WIDE_INT
6609 && host_integerp (and1
, 1))
6611 unsigned HOST_WIDE_INT cst
;
6613 cst
= tree_low_cst (and1
, 1);
6614 cst
&= (HOST_WIDE_INT
) -1
6615 << (TYPE_PRECISION (TREE_TYPE (and1
)) - 1);
6616 change
= (cst
== 0);
6617 #ifdef LOAD_EXTEND_OP
6619 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0
)))
6622 tree uns
= lang_hooks
.types
.unsigned_type (TREE_TYPE (and0
));
6623 and0
= fold_convert (uns
, and0
);
6624 and1
= fold_convert (uns
, and1
);
6629 return fold (build2 (BIT_AND_EXPR
, type
,
6630 fold_convert (type
, and0
),
6631 fold_convert (type
, and1
)));
6634 /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
6635 T2 being pointers to types of the same size. */
6636 if (POINTER_TYPE_P (TREE_TYPE (t
))
6637 && BINARY_CLASS_P (arg0
)
6638 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == NOP_EXPR
6639 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
6641 tree arg00
= TREE_OPERAND (arg0
, 0);
6642 tree t0
= TREE_TYPE (t
);
6643 tree t1
= TREE_TYPE (arg00
);
6644 tree tt0
= TREE_TYPE (t0
);
6645 tree tt1
= TREE_TYPE (t1
);
6646 tree s0
= TYPE_SIZE (tt0
);
6647 tree s1
= TYPE_SIZE (tt1
);
6649 if (s0
&& s1
&& operand_equal_p (s0
, s1
, OEP_ONLY_CONST
))
6650 return build2 (TREE_CODE (arg0
), t0
, fold_convert (t0
, arg00
),
6651 TREE_OPERAND (arg0
, 1));
6654 tem
= fold_convert_const (code
, type
, arg0
);
6655 return tem
? tem
: t
;
6657 case VIEW_CONVERT_EXPR
:
6658 if (TREE_CODE (TREE_OPERAND (t
, 0)) == VIEW_CONVERT_EXPR
)
6659 return build1 (VIEW_CONVERT_EXPR
, type
,
6660 TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
6664 if (TREE_CODE (arg0
) == CONSTRUCTOR
6665 && ! type_contains_placeholder_p (TREE_TYPE (arg0
)))
6667 tree m
= purpose_member (arg1
, CONSTRUCTOR_ELTS (arg0
));
6669 return TREE_VALUE (m
);
6674 if (TREE_CONSTANT (t
) != wins
)
6676 tem
= copy_node (t
);
6677 TREE_CONSTANT (tem
) = wins
;
6678 TREE_INVARIANT (tem
) = wins
;
6684 if (negate_expr_p (arg0
))
6685 return fold_convert (type
, negate_expr (arg0
));
6689 if (TREE_CODE (arg0
) == INTEGER_CST
|| TREE_CODE (arg0
) == REAL_CST
)
6690 return fold_abs_const (arg0
, type
);
6691 else if (TREE_CODE (arg0
) == NEGATE_EXPR
)
6692 return fold (build1 (ABS_EXPR
, type
, TREE_OPERAND (arg0
, 0)));
6693 /* Convert fabs((double)float) into (double)fabsf(float). */
6694 else if (TREE_CODE (arg0
) == NOP_EXPR
6695 && TREE_CODE (type
) == REAL_TYPE
)
6697 tree targ0
= strip_float_extensions (arg0
);
6699 return fold_convert (type
, fold (build1 (ABS_EXPR
,
6703 else if (tree_expr_nonnegative_p (arg0
))
6708 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
6709 return fold_convert (type
, arg0
);
6710 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
6711 return build2 (COMPLEX_EXPR
, type
,
6712 TREE_OPERAND (arg0
, 0),
6713 negate_expr (TREE_OPERAND (arg0
, 1)));
6714 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
6715 return build_complex (type
, TREE_REALPART (arg0
),
6716 negate_expr (TREE_IMAGPART (arg0
)));
6717 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
6718 return fold (build2 (TREE_CODE (arg0
), type
,
6719 fold (build1 (CONJ_EXPR
, type
,
6720 TREE_OPERAND (arg0
, 0))),
6721 fold (build1 (CONJ_EXPR
, type
,
6722 TREE_OPERAND (arg0
, 1)))));
6723 else if (TREE_CODE (arg0
) == CONJ_EXPR
)
6724 return TREE_OPERAND (arg0
, 0);
6728 if (TREE_CODE (arg0
) == INTEGER_CST
)
6729 return fold_not_const (arg0
, type
);
6730 else if (TREE_CODE (arg0
) == BIT_NOT_EXPR
)
6731 return TREE_OPERAND (arg0
, 0);
6735 /* A + (-B) -> A - B */
6736 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
6737 return fold (build2 (MINUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
6738 /* (-A) + B -> B - A */
6739 if (TREE_CODE (arg0
) == NEGATE_EXPR
6740 && reorder_operands_p (TREE_OPERAND (arg0
, 0), arg1
))
6741 return fold (build2 (MINUS_EXPR
, type
, arg1
, TREE_OPERAND (arg0
, 0)));
6742 if (! FLOAT_TYPE_P (type
))
6744 if (integer_zerop (arg1
))
6745 return non_lvalue (fold_convert (type
, arg0
));
6747 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
6748 with a constant, and the two constants have no bits in common,
6749 we should treat this as a BIT_IOR_EXPR since this may produce more
6751 if (TREE_CODE (arg0
) == BIT_AND_EXPR
6752 && TREE_CODE (arg1
) == BIT_AND_EXPR
6753 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
6754 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
6755 && integer_zerop (const_binop (BIT_AND_EXPR
,
6756 TREE_OPERAND (arg0
, 1),
6757 TREE_OPERAND (arg1
, 1), 0)))
6759 code
= BIT_IOR_EXPR
;
6763 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
6764 (plus (plus (mult) (mult)) (foo)) so that we can
6765 take advantage of the factoring cases below. */
6766 if (((TREE_CODE (arg0
) == PLUS_EXPR
6767 || TREE_CODE (arg0
) == MINUS_EXPR
)
6768 && TREE_CODE (arg1
) == MULT_EXPR
)
6769 || ((TREE_CODE (arg1
) == PLUS_EXPR
6770 || TREE_CODE (arg1
) == MINUS_EXPR
)
6771 && TREE_CODE (arg0
) == MULT_EXPR
))
6773 tree parg0
, parg1
, parg
, marg
;
6774 enum tree_code pcode
;
6776 if (TREE_CODE (arg1
) == MULT_EXPR
)
6777 parg
= arg0
, marg
= arg1
;
6779 parg
= arg1
, marg
= arg0
;
6780 pcode
= TREE_CODE (parg
);
6781 parg0
= TREE_OPERAND (parg
, 0);
6782 parg1
= TREE_OPERAND (parg
, 1);
6786 if (TREE_CODE (parg0
) == MULT_EXPR
6787 && TREE_CODE (parg1
) != MULT_EXPR
)
6788 return fold (build2 (pcode
, type
,
6789 fold (build2 (PLUS_EXPR
, type
,
6790 fold_convert (type
, parg0
),
6791 fold_convert (type
, marg
))),
6792 fold_convert (type
, parg1
)));
6793 if (TREE_CODE (parg0
) != MULT_EXPR
6794 && TREE_CODE (parg1
) == MULT_EXPR
)
6795 return fold (build2 (PLUS_EXPR
, type
,
6796 fold_convert (type
, parg0
),
6797 fold (build2 (pcode
, type
,
6798 fold_convert (type
, marg
),
6803 if (TREE_CODE (arg0
) == MULT_EXPR
&& TREE_CODE (arg1
) == MULT_EXPR
)
6805 tree arg00
, arg01
, arg10
, arg11
;
6806 tree alt0
= NULL_TREE
, alt1
= NULL_TREE
, same
;
6808 /* (A * C) + (B * C) -> (A+B) * C.
6809 We are most concerned about the case where C is a constant,
6810 but other combinations show up during loop reduction. Since
6811 it is not difficult, try all four possibilities. */
6813 arg00
= TREE_OPERAND (arg0
, 0);
6814 arg01
= TREE_OPERAND (arg0
, 1);
6815 arg10
= TREE_OPERAND (arg1
, 0);
6816 arg11
= TREE_OPERAND (arg1
, 1);
6819 if (operand_equal_p (arg01
, arg11
, 0))
6820 same
= arg01
, alt0
= arg00
, alt1
= arg10
;
6821 else if (operand_equal_p (arg00
, arg10
, 0))
6822 same
= arg00
, alt0
= arg01
, alt1
= arg11
;
6823 else if (operand_equal_p (arg00
, arg11
, 0))
6824 same
= arg00
, alt0
= arg01
, alt1
= arg10
;
6825 else if (operand_equal_p (arg01
, arg10
, 0))
6826 same
= arg01
, alt0
= arg00
, alt1
= arg11
;
6828 /* No identical multiplicands; see if we can find a common
6829 power-of-two factor in non-power-of-two multiplies. This
6830 can help in multi-dimensional array access. */
6831 else if (TREE_CODE (arg01
) == INTEGER_CST
6832 && TREE_CODE (arg11
) == INTEGER_CST
6833 && TREE_INT_CST_HIGH (arg01
) == 0
6834 && TREE_INT_CST_HIGH (arg11
) == 0)
6836 HOST_WIDE_INT int01
, int11
, tmp
;
6837 int01
= TREE_INT_CST_LOW (arg01
);
6838 int11
= TREE_INT_CST_LOW (arg11
);
6840 /* Move min of absolute values to int11. */
6841 if ((int01
>= 0 ? int01
: -int01
)
6842 < (int11
>= 0 ? int11
: -int11
))
6844 tmp
= int01
, int01
= int11
, int11
= tmp
;
6845 alt0
= arg00
, arg00
= arg10
, arg10
= alt0
;
6846 alt0
= arg01
, arg01
= arg11
, arg11
= alt0
;
6849 if (exact_log2 (int11
) > 0 && int01
% int11
== 0)
6851 alt0
= fold (build2 (MULT_EXPR
, type
, arg00
,
6852 build_int_cst (NULL_TREE
,
6860 return fold (build2 (MULT_EXPR
, type
,
6861 fold (build2 (PLUS_EXPR
, type
,
6862 fold_convert (type
, alt0
),
6863 fold_convert (type
, alt1
))),
6867 /* Try replacing &a[i1] + c * i2 with &a[i1 + i2], if c is step
6868 of the array. Loop optimizer sometimes produce this type of
6870 if (TREE_CODE (arg0
) == ADDR_EXPR
6871 && TREE_CODE (arg1
) == MULT_EXPR
)
6873 tem
= try_move_mult_to_index (type
, PLUS_EXPR
, arg0
, arg1
);
6877 else if (TREE_CODE (arg1
) == ADDR_EXPR
6878 && TREE_CODE (arg0
) == MULT_EXPR
)
6880 tem
= try_move_mult_to_index (type
, PLUS_EXPR
, arg1
, arg0
);
6887 /* See if ARG1 is zero and X + ARG1 reduces to X. */
6888 if (fold_real_zero_addition_p (TREE_TYPE (arg0
), arg1
, 0))
6889 return non_lvalue (fold_convert (type
, arg0
));
6891 /* Likewise if the operands are reversed. */
6892 if (fold_real_zero_addition_p (TREE_TYPE (arg1
), arg0
, 0))
6893 return non_lvalue (fold_convert (type
, arg1
));
6895 /* Convert X + -C into X - C. */
6896 if (TREE_CODE (arg1
) == REAL_CST
6897 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1
)))
6899 tem
= fold_negate_const (arg1
, type
);
6900 if (!TREE_OVERFLOW (arg1
) || !flag_trapping_math
)
6901 return fold (build2 (MINUS_EXPR
, type
,
6902 fold_convert (type
, arg0
),
6903 fold_convert (type
, tem
)));
6906 /* Convert x+x into x*2.0. */
6907 if (operand_equal_p (arg0
, arg1
, 0)
6908 && SCALAR_FLOAT_TYPE_P (type
))
6909 return fold (build2 (MULT_EXPR
, type
, arg0
,
6910 build_real (type
, dconst2
)));
6912 /* Convert x*c+x into x*(c+1). */
6913 if (flag_unsafe_math_optimizations
6914 && TREE_CODE (arg0
) == MULT_EXPR
6915 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == REAL_CST
6916 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0
, 1))
6917 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
6921 c
= TREE_REAL_CST (TREE_OPERAND (arg0
, 1));
6922 real_arithmetic (&c
, PLUS_EXPR
, &c
, &dconst1
);
6923 return fold (build2 (MULT_EXPR
, type
, arg1
,
6924 build_real (type
, c
)));
6927 /* Convert x+x*c into x*(c+1). */
6928 if (flag_unsafe_math_optimizations
6929 && TREE_CODE (arg1
) == MULT_EXPR
6930 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == REAL_CST
6931 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1
, 1))
6932 && operand_equal_p (TREE_OPERAND (arg1
, 0), arg0
, 0))
6936 c
= TREE_REAL_CST (TREE_OPERAND (arg1
, 1));
6937 real_arithmetic (&c
, PLUS_EXPR
, &c
, &dconst1
);
6938 return fold (build2 (MULT_EXPR
, type
, arg0
,
6939 build_real (type
, c
)));
6942 /* Convert x*c1+x*c2 into x*(c1+c2). */
6943 if (flag_unsafe_math_optimizations
6944 && TREE_CODE (arg0
) == MULT_EXPR
6945 && TREE_CODE (arg1
) == MULT_EXPR
6946 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == REAL_CST
6947 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0
, 1))
6948 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == REAL_CST
6949 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1
, 1))
6950 && operand_equal_p (TREE_OPERAND (arg0
, 0),
6951 TREE_OPERAND (arg1
, 0), 0))
6953 REAL_VALUE_TYPE c1
, c2
;
6955 c1
= TREE_REAL_CST (TREE_OPERAND (arg0
, 1));
6956 c2
= TREE_REAL_CST (TREE_OPERAND (arg1
, 1));
6957 real_arithmetic (&c1
, PLUS_EXPR
, &c1
, &c2
);
6958 return fold (build2 (MULT_EXPR
, type
,
6959 TREE_OPERAND (arg0
, 0),
6960 build_real (type
, c1
)));
6962 /* Convert a + (b*c + d*e) into (a + b*c) + d*e. */
6963 if (flag_unsafe_math_optimizations
6964 && TREE_CODE (arg1
) == PLUS_EXPR
6965 && TREE_CODE (arg0
) != MULT_EXPR
)
6967 tree tree10
= TREE_OPERAND (arg1
, 0);
6968 tree tree11
= TREE_OPERAND (arg1
, 1);
6969 if (TREE_CODE (tree11
) == MULT_EXPR
6970 && TREE_CODE (tree10
) == MULT_EXPR
)
6973 tree0
= fold (build2 (PLUS_EXPR
, type
, arg0
, tree10
));
6974 return fold (build2 (PLUS_EXPR
, type
, tree0
, tree11
));
6977 /* Convert (b*c + d*e) + a into b*c + (d*e +a). */
6978 if (flag_unsafe_math_optimizations
6979 && TREE_CODE (arg0
) == PLUS_EXPR
6980 && TREE_CODE (arg1
) != MULT_EXPR
)
6982 tree tree00
= TREE_OPERAND (arg0
, 0);
6983 tree tree01
= TREE_OPERAND (arg0
, 1);
6984 if (TREE_CODE (tree01
) == MULT_EXPR
6985 && TREE_CODE (tree00
) == MULT_EXPR
)
6988 tree0
= fold (build2 (PLUS_EXPR
, type
, tree01
, arg1
));
6989 return fold (build2 (PLUS_EXPR
, type
, tree00
, tree0
));
6995 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
6996 is a rotate of A by C1 bits. */
6997 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
6998 is a rotate of A by B bits. */
7000 enum tree_code code0
, code1
;
7001 code0
= TREE_CODE (arg0
);
7002 code1
= TREE_CODE (arg1
);
7003 if (((code0
== RSHIFT_EXPR
&& code1
== LSHIFT_EXPR
)
7004 || (code1
== RSHIFT_EXPR
&& code0
== LSHIFT_EXPR
))
7005 && operand_equal_p (TREE_OPERAND (arg0
, 0),
7006 TREE_OPERAND (arg1
, 0), 0)
7007 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
7009 tree tree01
, tree11
;
7010 enum tree_code code01
, code11
;
7012 tree01
= TREE_OPERAND (arg0
, 1);
7013 tree11
= TREE_OPERAND (arg1
, 1);
7014 STRIP_NOPS (tree01
);
7015 STRIP_NOPS (tree11
);
7016 code01
= TREE_CODE (tree01
);
7017 code11
= TREE_CODE (tree11
);
7018 if (code01
== INTEGER_CST
7019 && code11
== INTEGER_CST
7020 && TREE_INT_CST_HIGH (tree01
) == 0
7021 && TREE_INT_CST_HIGH (tree11
) == 0
7022 && ((TREE_INT_CST_LOW (tree01
) + TREE_INT_CST_LOW (tree11
))
7023 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)))))
7024 return build2 (LROTATE_EXPR
, type
, TREE_OPERAND (arg0
, 0),
7025 code0
== LSHIFT_EXPR
? tree01
: tree11
);
7026 else if (code11
== MINUS_EXPR
)
7028 tree tree110
, tree111
;
7029 tree110
= TREE_OPERAND (tree11
, 0);
7030 tree111
= TREE_OPERAND (tree11
, 1);
7031 STRIP_NOPS (tree110
);
7032 STRIP_NOPS (tree111
);
7033 if (TREE_CODE (tree110
) == INTEGER_CST
7034 && 0 == compare_tree_int (tree110
,
7036 (TREE_TYPE (TREE_OPERAND
7038 && operand_equal_p (tree01
, tree111
, 0))
7039 return build2 ((code0
== LSHIFT_EXPR
7042 type
, TREE_OPERAND (arg0
, 0), tree01
);
7044 else if (code01
== MINUS_EXPR
)
7046 tree tree010
, tree011
;
7047 tree010
= TREE_OPERAND (tree01
, 0);
7048 tree011
= TREE_OPERAND (tree01
, 1);
7049 STRIP_NOPS (tree010
);
7050 STRIP_NOPS (tree011
);
7051 if (TREE_CODE (tree010
) == INTEGER_CST
7052 && 0 == compare_tree_int (tree010
,
7054 (TREE_TYPE (TREE_OPERAND
7056 && operand_equal_p (tree11
, tree011
, 0))
7057 return build2 ((code0
!= LSHIFT_EXPR
7060 type
, TREE_OPERAND (arg0
, 0), tree11
);
7066 /* In most languages, can't associate operations on floats through
7067 parentheses. Rather than remember where the parentheses were, we
7068 don't associate floats at all, unless the user has specified
7069 -funsafe-math-optimizations. */
7072 && (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
))
7074 tree var0
, con0
, lit0
, minus_lit0
;
7075 tree var1
, con1
, lit1
, minus_lit1
;
7077 /* Split both trees into variables, constants, and literals. Then
7078 associate each group together, the constants with literals,
7079 then the result with variables. This increases the chances of
7080 literals being recombined later and of generating relocatable
7081 expressions for the sum of a constant and literal. */
7082 var0
= split_tree (arg0
, code
, &con0
, &lit0
, &minus_lit0
, 0);
7083 var1
= split_tree (arg1
, code
, &con1
, &lit1
, &minus_lit1
,
7084 code
== MINUS_EXPR
);
7086 /* Only do something if we found more than two objects. Otherwise,
7087 nothing has changed and we risk infinite recursion. */
7088 if (2 < ((var0
!= 0) + (var1
!= 0)
7089 + (con0
!= 0) + (con1
!= 0)
7090 + (lit0
!= 0) + (lit1
!= 0)
7091 + (minus_lit0
!= 0) + (minus_lit1
!= 0)))
7093 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
7094 if (code
== MINUS_EXPR
)
7097 var0
= associate_trees (var0
, var1
, code
, type
);
7098 con0
= associate_trees (con0
, con1
, code
, type
);
7099 lit0
= associate_trees (lit0
, lit1
, code
, type
);
7100 minus_lit0
= associate_trees (minus_lit0
, minus_lit1
, code
, type
);
7102 /* Preserve the MINUS_EXPR if the negative part of the literal is
7103 greater than the positive part. Otherwise, the multiplicative
7104 folding code (i.e extract_muldiv) may be fooled in case
7105 unsigned constants are subtracted, like in the following
7106 example: ((X*2 + 4) - 8U)/2. */
7107 if (minus_lit0
&& lit0
)
7109 if (TREE_CODE (lit0
) == INTEGER_CST
7110 && TREE_CODE (minus_lit0
) == INTEGER_CST
7111 && tree_int_cst_lt (lit0
, minus_lit0
))
7113 minus_lit0
= associate_trees (minus_lit0
, lit0
,
7119 lit0
= associate_trees (lit0
, minus_lit0
,
7127 return fold_convert (type
,
7128 associate_trees (var0
, minus_lit0
,
7132 con0
= associate_trees (con0
, minus_lit0
,
7134 return fold_convert (type
,
7135 associate_trees (var0
, con0
,
7140 con0
= associate_trees (con0
, lit0
, code
, type
);
7141 return fold_convert (type
, associate_trees (var0
, con0
,
7148 t1
= const_binop (code
, arg0
, arg1
, 0);
7149 if (t1
!= NULL_TREE
)
7151 /* The return value should always have
7152 the same type as the original expression. */
7153 if (TREE_TYPE (t1
) != type
)
7154 t1
= fold_convert (type
, t1
);
7161 /* A - (-B) -> A + B */
7162 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
7163 return fold (build2 (PLUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
7164 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
7165 if (TREE_CODE (arg0
) == NEGATE_EXPR
7166 && (FLOAT_TYPE_P (type
)
7167 || (INTEGRAL_TYPE_P (type
) && flag_wrapv
&& !flag_trapv
))
7168 && negate_expr_p (arg1
)
7169 && reorder_operands_p (arg0
, arg1
))
7170 return fold (build2 (MINUS_EXPR
, type
, negate_expr (arg1
),
7171 TREE_OPERAND (arg0
, 0)));
7173 if (! FLOAT_TYPE_P (type
))
7175 if (! wins
&& integer_zerop (arg0
))
7176 return negate_expr (fold_convert (type
, arg1
));
7177 if (integer_zerop (arg1
))
7178 return non_lvalue (fold_convert (type
, arg0
));
7180 /* Fold A - (A & B) into ~B & A. */
7181 if (!TREE_SIDE_EFFECTS (arg0
)
7182 && TREE_CODE (arg1
) == BIT_AND_EXPR
)
7184 if (operand_equal_p (arg0
, TREE_OPERAND (arg1
, 1), 0))
7185 return fold (build2 (BIT_AND_EXPR
, type
,
7186 fold (build1 (BIT_NOT_EXPR
, type
,
7187 TREE_OPERAND (arg1
, 0))),
7189 if (operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
7190 return fold (build2 (BIT_AND_EXPR
, type
,
7191 fold (build1 (BIT_NOT_EXPR
, type
,
7192 TREE_OPERAND (arg1
, 1))),
7196 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
7197 any power of 2 minus 1. */
7198 if (TREE_CODE (arg0
) == BIT_AND_EXPR
7199 && TREE_CODE (arg1
) == BIT_AND_EXPR
7200 && operand_equal_p (TREE_OPERAND (arg0
, 0),
7201 TREE_OPERAND (arg1
, 0), 0))
7203 tree mask0
= TREE_OPERAND (arg0
, 1);
7204 tree mask1
= TREE_OPERAND (arg1
, 1);
7205 tree tem
= fold (build1 (BIT_NOT_EXPR
, type
, mask0
));
7207 if (operand_equal_p (tem
, mask1
, 0))
7209 tem
= fold (build2 (BIT_XOR_EXPR
, type
,
7210 TREE_OPERAND (arg0
, 0), mask1
));
7211 return fold (build2 (MINUS_EXPR
, type
, tem
, mask1
));
7216 /* See if ARG1 is zero and X - ARG1 reduces to X. */
7217 else if (fold_real_zero_addition_p (TREE_TYPE (arg0
), arg1
, 1))
7218 return non_lvalue (fold_convert (type
, arg0
));
7220 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
7221 ARG0 is zero and X + ARG0 reduces to X, since that would mean
7222 (-ARG1 + ARG0) reduces to -ARG1. */
7223 else if (!wins
&& fold_real_zero_addition_p (TREE_TYPE (arg1
), arg0
, 0))
7224 return negate_expr (fold_convert (type
, arg1
));
7226 /* Fold &x - &x. This can happen from &x.foo - &x.
7227 This is unsafe for certain floats even in non-IEEE formats.
7228 In IEEE, it is unsafe because it does wrong for NaNs.
7229 Also note that operand_equal_p is always false if an operand
7232 if ((! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
7233 && operand_equal_p (arg0
, arg1
, 0))
7234 return fold_convert (type
, integer_zero_node
);
7236 /* A - B -> A + (-B) if B is easily negatable. */
7237 if (!wins
&& negate_expr_p (arg1
)
7238 && ((FLOAT_TYPE_P (type
)
7239 /* Avoid this transformation if B is a positive REAL_CST. */
7240 && (TREE_CODE (arg1
) != REAL_CST
7241 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1
))))
7242 || (INTEGRAL_TYPE_P (type
) && flag_wrapv
&& !flag_trapv
)))
7243 return fold (build2 (PLUS_EXPR
, type
, arg0
, negate_expr (arg1
)));
7245 /* Try folding difference of addresses. */
7249 if ((TREE_CODE (arg0
) == ADDR_EXPR
7250 || TREE_CODE (arg1
) == ADDR_EXPR
)
7251 && ptr_difference_const (arg0
, arg1
, &diff
))
7252 return build_int_cst_type (type
, diff
);
7255 /* Try replacing &a[i1] - c * i2 with &a[i1 - i2], if c is step
7256 of the array. Loop optimizer sometimes produce this type of
7258 if (TREE_CODE (arg0
) == ADDR_EXPR
7259 && TREE_CODE (arg1
) == MULT_EXPR
)
7261 tem
= try_move_mult_to_index (type
, MINUS_EXPR
, arg0
, arg1
);
7266 if (TREE_CODE (arg0
) == MULT_EXPR
7267 && TREE_CODE (arg1
) == MULT_EXPR
7268 && (!FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
))
7270 /* (A * C) - (B * C) -> (A-B) * C. */
7271 if (operand_equal_p (TREE_OPERAND (arg0
, 1),
7272 TREE_OPERAND (arg1
, 1), 0))
7273 return fold (build2 (MULT_EXPR
, type
,
7274 fold (build2 (MINUS_EXPR
, type
,
7275 TREE_OPERAND (arg0
, 0),
7276 TREE_OPERAND (arg1
, 0))),
7277 TREE_OPERAND (arg0
, 1)));
7278 /* (A * C1) - (A * C2) -> A * (C1-C2). */
7279 if (operand_equal_p (TREE_OPERAND (arg0
, 0),
7280 TREE_OPERAND (arg1
, 0), 0))
7281 return fold (build2 (MULT_EXPR
, type
,
7282 TREE_OPERAND (arg0
, 0),
7283 fold (build2 (MINUS_EXPR
, type
,
7284 TREE_OPERAND (arg0
, 1),
7285 TREE_OPERAND (arg1
, 1)))));
7291 /* (-A) * (-B) -> A * B */
7292 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& negate_expr_p (arg1
))
7293 return fold (build2 (MULT_EXPR
, type
,
7294 TREE_OPERAND (arg0
, 0),
7295 negate_expr (arg1
)));
7296 if (TREE_CODE (arg1
) == NEGATE_EXPR
&& negate_expr_p (arg0
))
7297 return fold (build2 (MULT_EXPR
, type
,
7299 TREE_OPERAND (arg1
, 0)));
7301 if (! FLOAT_TYPE_P (type
))
7303 if (integer_zerop (arg1
))
7304 return omit_one_operand (type
, arg1
, arg0
);
7305 if (integer_onep (arg1
))
7306 return non_lvalue (fold_convert (type
, arg0
));
7308 /* (a * (1 << b)) is (a << b) */
7309 if (TREE_CODE (arg1
) == LSHIFT_EXPR
7310 && integer_onep (TREE_OPERAND (arg1
, 0)))
7311 return fold (build2 (LSHIFT_EXPR
, type
, arg0
,
7312 TREE_OPERAND (arg1
, 1)));
7313 if (TREE_CODE (arg0
) == LSHIFT_EXPR
7314 && integer_onep (TREE_OPERAND (arg0
, 0)))
7315 return fold (build2 (LSHIFT_EXPR
, type
, arg1
,
7316 TREE_OPERAND (arg0
, 1)));
7318 if (TREE_CODE (arg1
) == INTEGER_CST
7319 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0),
7320 fold_convert (type
, arg1
),
7322 return fold_convert (type
, tem
);
7327 /* Maybe fold x * 0 to 0. The expressions aren't the same
7328 when x is NaN, since x * 0 is also NaN. Nor are they the
7329 same in modes with signed zeros, since multiplying a
7330 negative value by 0 gives -0, not +0. */
7331 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
)))
7332 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0
)))
7333 && real_zerop (arg1
))
7334 return omit_one_operand (type
, arg1
, arg0
);
7335 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
7336 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
7337 && real_onep (arg1
))
7338 return non_lvalue (fold_convert (type
, arg0
));
7340 /* Transform x * -1.0 into -x. */
7341 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
7342 && real_minus_onep (arg1
))
7343 return fold_convert (type
, negate_expr (arg0
));
7345 /* Convert (C1/X)*C2 into (C1*C2)/X. */
7346 if (flag_unsafe_math_optimizations
7347 && TREE_CODE (arg0
) == RDIV_EXPR
7348 && TREE_CODE (arg1
) == REAL_CST
7349 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == REAL_CST
)
7351 tree tem
= const_binop (MULT_EXPR
, TREE_OPERAND (arg0
, 0),
7354 return fold (build2 (RDIV_EXPR
, type
, tem
,
7355 TREE_OPERAND (arg0
, 1)));
7358 if (flag_unsafe_math_optimizations
)
7360 enum built_in_function fcode0
= builtin_mathfn_code (arg0
);
7361 enum built_in_function fcode1
= builtin_mathfn_code (arg1
);
7363 /* Optimizations of root(...)*root(...). */
7364 if (fcode0
== fcode1
&& BUILTIN_ROOT_P (fcode0
))
7366 tree rootfn
, arg
, arglist
;
7367 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
7368 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
7370 /* Optimize sqrt(x)*sqrt(x) as x. */
7371 if (BUILTIN_SQRT_P (fcode0
)
7372 && operand_equal_p (arg00
, arg10
, 0)
7373 && ! HONOR_SNANS (TYPE_MODE (type
)))
7376 /* Optimize root(x)*root(y) as root(x*y). */
7377 rootfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
7378 arg
= fold (build2 (MULT_EXPR
, type
, arg00
, arg10
));
7379 arglist
= build_tree_list (NULL_TREE
, arg
);
7380 return build_function_call_expr (rootfn
, arglist
);
7383 /* Optimize expN(x)*expN(y) as expN(x+y). */
7384 if (fcode0
== fcode1
&& BUILTIN_EXPONENT_P (fcode0
))
7386 tree expfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
7387 tree arg
= build2 (PLUS_EXPR
, type
,
7388 TREE_VALUE (TREE_OPERAND (arg0
, 1)),
7389 TREE_VALUE (TREE_OPERAND (arg1
, 1)));
7390 tree arglist
= build_tree_list (NULL_TREE
, fold (arg
));
7391 return build_function_call_expr (expfn
, arglist
);
7394 /* Optimizations of pow(...)*pow(...). */
7395 if ((fcode0
== BUILT_IN_POW
&& fcode1
== BUILT_IN_POW
)
7396 || (fcode0
== BUILT_IN_POWF
&& fcode1
== BUILT_IN_POWF
)
7397 || (fcode0
== BUILT_IN_POWL
&& fcode1
== BUILT_IN_POWL
))
7399 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
7400 tree arg01
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0
,
7402 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
7403 tree arg11
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1
,
7406 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
7407 if (operand_equal_p (arg01
, arg11
, 0))
7409 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
7410 tree arg
= build2 (MULT_EXPR
, type
, arg00
, arg10
);
7411 tree arglist
= tree_cons (NULL_TREE
, fold (arg
),
7412 build_tree_list (NULL_TREE
,
7414 return build_function_call_expr (powfn
, arglist
);
7417 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
7418 if (operand_equal_p (arg00
, arg10
, 0))
7420 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
7421 tree arg
= fold (build2 (PLUS_EXPR
, type
, arg01
, arg11
));
7422 tree arglist
= tree_cons (NULL_TREE
, arg00
,
7423 build_tree_list (NULL_TREE
,
7425 return build_function_call_expr (powfn
, arglist
);
7429 /* Optimize tan(x)*cos(x) as sin(x). */
7430 if (((fcode0
== BUILT_IN_TAN
&& fcode1
== BUILT_IN_COS
)
7431 || (fcode0
== BUILT_IN_TANF
&& fcode1
== BUILT_IN_COSF
)
7432 || (fcode0
== BUILT_IN_TANL
&& fcode1
== BUILT_IN_COSL
)
7433 || (fcode0
== BUILT_IN_COS
&& fcode1
== BUILT_IN_TAN
)
7434 || (fcode0
== BUILT_IN_COSF
&& fcode1
== BUILT_IN_TANF
)
7435 || (fcode0
== BUILT_IN_COSL
&& fcode1
== BUILT_IN_TANL
))
7436 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0
, 1)),
7437 TREE_VALUE (TREE_OPERAND (arg1
, 1)), 0))
7439 tree sinfn
= mathfn_built_in (type
, BUILT_IN_SIN
);
7441 if (sinfn
!= NULL_TREE
)
7442 return build_function_call_expr (sinfn
,
7443 TREE_OPERAND (arg0
, 1));
7446 /* Optimize x*pow(x,c) as pow(x,c+1). */
7447 if (fcode1
== BUILT_IN_POW
7448 || fcode1
== BUILT_IN_POWF
7449 || fcode1
== BUILT_IN_POWL
)
7451 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
7452 tree arg11
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1
,
7454 if (TREE_CODE (arg11
) == REAL_CST
7455 && ! TREE_CONSTANT_OVERFLOW (arg11
)
7456 && operand_equal_p (arg0
, arg10
, 0))
7458 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0);
7462 c
= TREE_REAL_CST (arg11
);
7463 real_arithmetic (&c
, PLUS_EXPR
, &c
, &dconst1
);
7464 arg
= build_real (type
, c
);
7465 arglist
= build_tree_list (NULL_TREE
, arg
);
7466 arglist
= tree_cons (NULL_TREE
, arg0
, arglist
);
7467 return build_function_call_expr (powfn
, arglist
);
7471 /* Optimize pow(x,c)*x as pow(x,c+1). */
7472 if (fcode0
== BUILT_IN_POW
7473 || fcode0
== BUILT_IN_POWF
7474 || fcode0
== BUILT_IN_POWL
)
7476 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
7477 tree arg01
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0
,
7479 if (TREE_CODE (arg01
) == REAL_CST
7480 && ! TREE_CONSTANT_OVERFLOW (arg01
)
7481 && operand_equal_p (arg1
, arg00
, 0))
7483 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
7487 c
= TREE_REAL_CST (arg01
);
7488 real_arithmetic (&c
, PLUS_EXPR
, &c
, &dconst1
);
7489 arg
= build_real (type
, c
);
7490 arglist
= build_tree_list (NULL_TREE
, arg
);
7491 arglist
= tree_cons (NULL_TREE
, arg1
, arglist
);
7492 return build_function_call_expr (powfn
, arglist
);
7496 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
7498 && operand_equal_p (arg0
, arg1
, 0))
7500 tree powfn
= mathfn_built_in (type
, BUILT_IN_POW
);
7504 tree arg
= build_real (type
, dconst2
);
7505 tree arglist
= build_tree_list (NULL_TREE
, arg
);
7506 arglist
= tree_cons (NULL_TREE
, arg0
, arglist
);
7507 return build_function_call_expr (powfn
, arglist
);
7516 if (integer_all_onesp (arg1
))
7517 return omit_one_operand (type
, arg1
, arg0
);
7518 if (integer_zerop (arg1
))
7519 return non_lvalue (fold_convert (type
, arg0
));
7520 if (operand_equal_p (arg0
, arg1
, 0))
7521 return non_lvalue (fold_convert (type
, arg0
));
7524 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
7525 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
7527 t1
= build_int_cst (type
, -1);
7528 t1
= force_fit_type (t1
, 0, false, false);
7529 return omit_one_operand (type
, t1
, arg1
);
7533 if (TREE_CODE (arg1
) == BIT_NOT_EXPR
7534 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
7536 t1
= build_int_cst (type
, -1);
7537 t1
= force_fit_type (t1
, 0, false, false);
7538 return omit_one_operand (type
, t1
, arg0
);
7541 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
7542 if (t1
!= NULL_TREE
)
7545 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
7547 This results in more efficient code for machines without a NAND
7548 instruction. Combine will canonicalize to the first form
7549 which will allow use of NAND instructions provided by the
7550 backend if they exist. */
7551 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
7552 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
7554 return fold (build1 (BIT_NOT_EXPR
, type
,
7555 build2 (BIT_AND_EXPR
, type
,
7556 TREE_OPERAND (arg0
, 0),
7557 TREE_OPERAND (arg1
, 0))));
7560 /* See if this can be simplified into a rotate first. If that
7561 is unsuccessful continue in the association code. */
7565 if (integer_zerop (arg1
))
7566 return non_lvalue (fold_convert (type
, arg0
));
7567 if (integer_all_onesp (arg1
))
7568 return fold (build1 (BIT_NOT_EXPR
, type
, arg0
));
7569 if (operand_equal_p (arg0
, arg1
, 0))
7570 return omit_one_operand (type
, integer_zero_node
, arg0
);
7573 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
7574 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
7576 t1
= build_int_cst (type
, -1);
7577 t1
= force_fit_type (t1
, 0, false, false);
7578 return omit_one_operand (type
, t1
, arg1
);
7582 if (TREE_CODE (arg1
) == BIT_NOT_EXPR
7583 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
7585 t1
= build_int_cst (type
, -1);
7586 t1
= force_fit_type (t1
, 0, false, false);
7587 return omit_one_operand (type
, t1
, arg0
);
7590 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
7591 with a constant, and the two constants have no bits in common,
7592 we should treat this as a BIT_IOR_EXPR since this may produce more
7594 if (TREE_CODE (arg0
) == BIT_AND_EXPR
7595 && TREE_CODE (arg1
) == BIT_AND_EXPR
7596 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
7597 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
7598 && integer_zerop (const_binop (BIT_AND_EXPR
,
7599 TREE_OPERAND (arg0
, 1),
7600 TREE_OPERAND (arg1
, 1), 0)))
7602 code
= BIT_IOR_EXPR
;
7606 /* See if this can be simplified into a rotate first. If that
7607 is unsuccessful continue in the association code. */
7611 if (integer_all_onesp (arg1
))
7612 return non_lvalue (fold_convert (type
, arg0
));
7613 if (integer_zerop (arg1
))
7614 return omit_one_operand (type
, arg1
, arg0
);
7615 if (operand_equal_p (arg0
, arg1
, 0))
7616 return non_lvalue (fold_convert (type
, arg0
));
7618 /* ~X & X is always zero. */
7619 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
7620 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
7621 return omit_one_operand (type
, integer_zero_node
, arg1
);
7623 /* X & ~X is always zero. */
7624 if (TREE_CODE (arg1
) == BIT_NOT_EXPR
7625 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
7626 return omit_one_operand (type
, integer_zero_node
, arg0
);
7628 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
7629 if (t1
!= NULL_TREE
)
7631 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
7632 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) == NOP_EXPR
7633 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
7636 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)));
7638 if (prec
< BITS_PER_WORD
&& prec
< HOST_BITS_PER_WIDE_INT
7639 && (~TREE_INT_CST_LOW (arg1
)
7640 & (((HOST_WIDE_INT
) 1 << prec
) - 1)) == 0)
7641 return fold_convert (type
, TREE_OPERAND (arg0
, 0));
7644 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
7646 This results in more efficient code for machines without a NOR
7647 instruction. Combine will canonicalize to the first form
7648 which will allow use of NOR instructions provided by the
7649 backend if they exist. */
7650 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
7651 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
7653 return fold (build1 (BIT_NOT_EXPR
, type
,
7654 build2 (BIT_IOR_EXPR
, type
,
7655 TREE_OPERAND (arg0
, 0),
7656 TREE_OPERAND (arg1
, 0))));
7662 /* Don't touch a floating-point divide by zero unless the mode
7663 of the constant can represent infinity. */
7664 if (TREE_CODE (arg1
) == REAL_CST
7665 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1
)))
7666 && real_zerop (arg1
))
7669 /* (-A) / (-B) -> A / B */
7670 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& negate_expr_p (arg1
))
7671 return fold (build2 (RDIV_EXPR
, type
,
7672 TREE_OPERAND (arg0
, 0),
7673 negate_expr (arg1
)));
7674 if (TREE_CODE (arg1
) == NEGATE_EXPR
&& negate_expr_p (arg0
))
7675 return fold (build2 (RDIV_EXPR
, type
,
7677 TREE_OPERAND (arg1
, 0)));
7679 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
7680 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
7681 && real_onep (arg1
))
7682 return non_lvalue (fold_convert (type
, arg0
));
7684 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
7685 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
7686 && real_minus_onep (arg1
))
7687 return non_lvalue (fold_convert (type
, negate_expr (arg0
)));
7689 /* If ARG1 is a constant, we can convert this to a multiply by the
7690 reciprocal. This does not have the same rounding properties,
7691 so only do this if -funsafe-math-optimizations. We can actually
7692 always safely do it if ARG1 is a power of two, but it's hard to
7693 tell if it is or not in a portable manner. */
7694 if (TREE_CODE (arg1
) == REAL_CST
)
7696 if (flag_unsafe_math_optimizations
7697 && 0 != (tem
= const_binop (code
, build_real (type
, dconst1
),
7699 return fold (build2 (MULT_EXPR
, type
, arg0
, tem
));
7700 /* Find the reciprocal if optimizing and the result is exact. */
7704 r
= TREE_REAL_CST (arg1
);
7705 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0
)), &r
))
7707 tem
= build_real (type
, r
);
7708 return fold (build2 (MULT_EXPR
, type
, arg0
, tem
));
7712 /* Convert A/B/C to A/(B*C). */
7713 if (flag_unsafe_math_optimizations
7714 && TREE_CODE (arg0
) == RDIV_EXPR
)
7715 return fold (build2 (RDIV_EXPR
, type
, TREE_OPERAND (arg0
, 0),
7716 fold (build2 (MULT_EXPR
, type
,
7717 TREE_OPERAND (arg0
, 1), arg1
))));
7719 /* Convert A/(B/C) to (A/B)*C. */
7720 if (flag_unsafe_math_optimizations
7721 && TREE_CODE (arg1
) == RDIV_EXPR
)
7722 return fold (build2 (MULT_EXPR
, type
,
7723 fold (build2 (RDIV_EXPR
, type
, arg0
,
7724 TREE_OPERAND (arg1
, 0))),
7725 TREE_OPERAND (arg1
, 1)));
7727 /* Convert C1/(X*C2) into (C1/C2)/X. */
7728 if (flag_unsafe_math_optimizations
7729 && TREE_CODE (arg1
) == MULT_EXPR
7730 && TREE_CODE (arg0
) == REAL_CST
7731 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == REAL_CST
)
7733 tree tem
= const_binop (RDIV_EXPR
, arg0
,
7734 TREE_OPERAND (arg1
, 1), 0);
7736 return fold (build2 (RDIV_EXPR
, type
, tem
,
7737 TREE_OPERAND (arg1
, 0)));
7740 if (flag_unsafe_math_optimizations
)
7742 enum built_in_function fcode
= builtin_mathfn_code (arg1
);
7743 /* Optimize x/expN(y) into x*expN(-y). */
7744 if (BUILTIN_EXPONENT_P (fcode
))
7746 tree expfn
= TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0);
7747 tree arg
= negate_expr (TREE_VALUE (TREE_OPERAND (arg1
, 1)));
7748 tree arglist
= build_tree_list (NULL_TREE
,
7749 fold_convert (type
, arg
));
7750 arg1
= build_function_call_expr (expfn
, arglist
);
7751 return fold (build2 (MULT_EXPR
, type
, arg0
, arg1
));
7754 /* Optimize x/pow(y,z) into x*pow(y,-z). */
7755 if (fcode
== BUILT_IN_POW
7756 || fcode
== BUILT_IN_POWF
7757 || fcode
== BUILT_IN_POWL
)
7759 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0);
7760 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
7761 tree arg11
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1
, 1)));
7762 tree neg11
= fold_convert (type
, negate_expr (arg11
));
7763 tree arglist
= tree_cons(NULL_TREE
, arg10
,
7764 build_tree_list (NULL_TREE
, neg11
));
7765 arg1
= build_function_call_expr (powfn
, arglist
);
7766 return fold (build2 (MULT_EXPR
, type
, arg0
, arg1
));
7770 if (flag_unsafe_math_optimizations
)
7772 enum built_in_function fcode0
= builtin_mathfn_code (arg0
);
7773 enum built_in_function fcode1
= builtin_mathfn_code (arg1
);
7775 /* Optimize sin(x)/cos(x) as tan(x). */
7776 if (((fcode0
== BUILT_IN_SIN
&& fcode1
== BUILT_IN_COS
)
7777 || (fcode0
== BUILT_IN_SINF
&& fcode1
== BUILT_IN_COSF
)
7778 || (fcode0
== BUILT_IN_SINL
&& fcode1
== BUILT_IN_COSL
))
7779 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0
, 1)),
7780 TREE_VALUE (TREE_OPERAND (arg1
, 1)), 0))
7782 tree tanfn
= mathfn_built_in (type
, BUILT_IN_TAN
);
7784 if (tanfn
!= NULL_TREE
)
7785 return build_function_call_expr (tanfn
,
7786 TREE_OPERAND (arg0
, 1));
7789 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
7790 if (((fcode0
== BUILT_IN_COS
&& fcode1
== BUILT_IN_SIN
)
7791 || (fcode0
== BUILT_IN_COSF
&& fcode1
== BUILT_IN_SINF
)
7792 || (fcode0
== BUILT_IN_COSL
&& fcode1
== BUILT_IN_SINL
))
7793 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0
, 1)),
7794 TREE_VALUE (TREE_OPERAND (arg1
, 1)), 0))
7796 tree tanfn
= mathfn_built_in (type
, BUILT_IN_TAN
);
7798 if (tanfn
!= NULL_TREE
)
7800 tree tmp
= TREE_OPERAND (arg0
, 1);
7801 tmp
= build_function_call_expr (tanfn
, tmp
);
7802 return fold (build2 (RDIV_EXPR
, type
,
7803 build_real (type
, dconst1
), tmp
));
7807 /* Optimize pow(x,c)/x as pow(x,c-1). */
7808 if (fcode0
== BUILT_IN_POW
7809 || fcode0
== BUILT_IN_POWF
7810 || fcode0
== BUILT_IN_POWL
)
7812 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
7813 tree arg01
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0
, 1)));
7814 if (TREE_CODE (arg01
) == REAL_CST
7815 && ! TREE_CONSTANT_OVERFLOW (arg01
)
7816 && operand_equal_p (arg1
, arg00
, 0))
7818 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
7822 c
= TREE_REAL_CST (arg01
);
7823 real_arithmetic (&c
, MINUS_EXPR
, &c
, &dconst1
);
7824 arg
= build_real (type
, c
);
7825 arglist
= build_tree_list (NULL_TREE
, arg
);
7826 arglist
= tree_cons (NULL_TREE
, arg1
, arglist
);
7827 return build_function_call_expr (powfn
, arglist
);
7833 case TRUNC_DIV_EXPR
:
7834 case ROUND_DIV_EXPR
:
7835 case FLOOR_DIV_EXPR
:
7837 case EXACT_DIV_EXPR
:
7838 if (integer_onep (arg1
))
7839 return non_lvalue (fold_convert (type
, arg0
));
7840 if (integer_zerop (arg1
))
7843 if (!TYPE_UNSIGNED (type
)
7844 && TREE_CODE (arg1
) == INTEGER_CST
7845 && TREE_INT_CST_LOW (arg1
) == (unsigned HOST_WIDE_INT
) -1
7846 && TREE_INT_CST_HIGH (arg1
) == -1)
7847 return fold_convert (type
, negate_expr (arg0
));
7849 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
7850 operation, EXACT_DIV_EXPR.
7852 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
7853 At one time others generated faster code, it's not clear if they do
7854 after the last round to changes to the DIV code in expmed.c. */
7855 if ((code
== CEIL_DIV_EXPR
|| code
== FLOOR_DIV_EXPR
)
7856 && multiple_of_p (type
, arg0
, arg1
))
7857 return fold (build2 (EXACT_DIV_EXPR
, type
, arg0
, arg1
));
7859 if (TREE_CODE (arg1
) == INTEGER_CST
7860 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
7862 return fold_convert (type
, tem
);
7867 case FLOOR_MOD_EXPR
:
7868 case ROUND_MOD_EXPR
:
7869 case TRUNC_MOD_EXPR
:
7870 if (integer_onep (arg1
))
7871 return omit_one_operand (type
, integer_zero_node
, arg0
);
7872 if (integer_zerop (arg1
))
7875 /* X % -1 is zero. */
7876 if (!TYPE_UNSIGNED (type
)
7877 && TREE_CODE (arg1
) == INTEGER_CST
7878 && TREE_INT_CST_LOW (arg1
) == (unsigned HOST_WIDE_INT
) -1
7879 && TREE_INT_CST_HIGH (arg1
) == -1)
7880 return omit_one_operand (type
, integer_zero_node
, arg0
);
7882 /* Optimize unsigned TRUNC_MOD_EXPR by a power of two into a
7883 BIT_AND_EXPR, i.e. "X % C" into "X & C2". */
7884 if (code
== TRUNC_MOD_EXPR
7885 && TYPE_UNSIGNED (type
)
7886 && integer_pow2p (arg1
))
7888 unsigned HOST_WIDE_INT high
, low
;
7892 l
= tree_log2 (arg1
);
7893 if (l
>= HOST_BITS_PER_WIDE_INT
)
7895 high
= ((unsigned HOST_WIDE_INT
) 1
7896 << (l
- HOST_BITS_PER_WIDE_INT
)) - 1;
7902 low
= ((unsigned HOST_WIDE_INT
) 1 << l
) - 1;
7905 mask
= build_int_cst_wide (type
, low
, high
);
7906 return fold (build2 (BIT_AND_EXPR
, type
,
7907 fold_convert (type
, arg0
), mask
));
7910 /* X % -C is the same as X % C. */
7911 if (code
== TRUNC_MOD_EXPR
7912 && !TYPE_UNSIGNED (type
)
7913 && TREE_CODE (arg1
) == INTEGER_CST
7914 && TREE_INT_CST_HIGH (arg1
) < 0
7916 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
7917 && !sign_bit_p (arg1
, arg1
))
7918 return fold (build2 (code
, type
, fold_convert (type
, arg0
),
7919 fold_convert (type
, negate_expr (arg1
))));
7921 /* X % -Y is the same as X % Y. */
7922 if (code
== TRUNC_MOD_EXPR
7923 && !TYPE_UNSIGNED (type
)
7924 && TREE_CODE (arg1
) == NEGATE_EXPR
7926 return fold (build2 (code
, type
, fold_convert (type
, arg0
),
7927 fold_convert (type
, TREE_OPERAND (arg1
, 0))));
7929 if (TREE_CODE (arg1
) == INTEGER_CST
7930 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
7932 return fold_convert (type
, tem
);
7938 if (integer_all_onesp (arg0
))
7939 return omit_one_operand (type
, arg0
, arg1
);
7943 /* Optimize -1 >> x for arithmetic right shifts. */
7944 if (integer_all_onesp (arg0
) && !TYPE_UNSIGNED (type
))
7945 return omit_one_operand (type
, arg0
, arg1
);
7946 /* ... fall through ... */
7950 if (integer_zerop (arg1
))
7951 return non_lvalue (fold_convert (type
, arg0
));
7952 if (integer_zerop (arg0
))
7953 return omit_one_operand (type
, arg0
, arg1
);
7955 /* Since negative shift count is not well-defined,
7956 don't try to compute it in the compiler. */
7957 if (TREE_CODE (arg1
) == INTEGER_CST
&& tree_int_cst_sgn (arg1
) < 0)
7959 /* Rewrite an LROTATE_EXPR by a constant into an
7960 RROTATE_EXPR by a new constant. */
7961 if (code
== LROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
)
7963 tree tem
= build_int_cst (NULL_TREE
,
7964 GET_MODE_BITSIZE (TYPE_MODE (type
)));
7965 tem
= fold_convert (TREE_TYPE (arg1
), tem
);
7966 tem
= const_binop (MINUS_EXPR
, tem
, arg1
, 0);
7967 return fold (build2 (RROTATE_EXPR
, type
, arg0
, tem
));
7970 /* If we have a rotate of a bit operation with the rotate count and
7971 the second operand of the bit operation both constant,
7972 permute the two operations. */
7973 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
7974 && (TREE_CODE (arg0
) == BIT_AND_EXPR
7975 || TREE_CODE (arg0
) == BIT_IOR_EXPR
7976 || TREE_CODE (arg0
) == BIT_XOR_EXPR
)
7977 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
7978 return fold (build2 (TREE_CODE (arg0
), type
,
7979 fold (build2 (code
, type
,
7980 TREE_OPERAND (arg0
, 0), arg1
)),
7981 fold (build2 (code
, type
,
7982 TREE_OPERAND (arg0
, 1), arg1
))));
7984 /* Two consecutive rotates adding up to the width of the mode can
7986 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
7987 && TREE_CODE (arg0
) == RROTATE_EXPR
7988 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
7989 && TREE_INT_CST_HIGH (arg1
) == 0
7990 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0
, 1)) == 0
7991 && ((TREE_INT_CST_LOW (arg1
)
7992 + TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1)))
7993 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type
))))
7994 return TREE_OPERAND (arg0
, 0);
7999 if (operand_equal_p (arg0
, arg1
, 0))
8000 return omit_one_operand (type
, arg0
, arg1
);
8001 if (INTEGRAL_TYPE_P (type
)
8002 && operand_equal_p (arg1
, TYPE_MIN_VALUE (type
), OEP_ONLY_CONST
))
8003 return omit_one_operand (type
, arg1
, arg0
);
8007 if (operand_equal_p (arg0
, arg1
, 0))
8008 return omit_one_operand (type
, arg0
, arg1
);
8009 if (INTEGRAL_TYPE_P (type
)
8010 && TYPE_MAX_VALUE (type
)
8011 && operand_equal_p (arg1
, TYPE_MAX_VALUE (type
), OEP_ONLY_CONST
))
8012 return omit_one_operand (type
, arg1
, arg0
);
8015 case TRUTH_NOT_EXPR
:
8016 /* The argument to invert_truthvalue must have Boolean type. */
8017 if (TREE_CODE (TREE_TYPE (arg0
)) != BOOLEAN_TYPE
)
8018 arg0
= fold_convert (boolean_type_node
, arg0
);
8020 /* Note that the operand of this must be an int
8021 and its values must be 0 or 1.
8022 ("true" is a fixed value perhaps depending on the language,
8023 but we don't handle values other than 1 correctly yet.) */
8024 tem
= invert_truthvalue (arg0
);
8025 /* Avoid infinite recursion. */
8026 if (TREE_CODE (tem
) == TRUTH_NOT_EXPR
)
8028 tem
= fold_single_bit_test (code
, arg0
, arg1
, type
);
8033 return fold_convert (type
, tem
);
8035 case TRUTH_ANDIF_EXPR
:
8036 /* Note that the operands of this must be ints
8037 and their values must be 0 or 1.
8038 ("true" is a fixed value perhaps depending on the language.) */
8039 /* If first arg is constant zero, return it. */
8040 if (integer_zerop (arg0
))
8041 return fold_convert (type
, arg0
);
8042 case TRUTH_AND_EXPR
:
8043 /* If either arg is constant true, drop it. */
8044 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
8045 return non_lvalue (fold_convert (type
, arg1
));
8046 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
)
8047 /* Preserve sequence points. */
8048 && (code
!= TRUTH_ANDIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
8049 return non_lvalue (fold_convert (type
, arg0
));
8050 /* If second arg is constant zero, result is zero, but first arg
8051 must be evaluated. */
8052 if (integer_zerop (arg1
))
8053 return omit_one_operand (type
, arg1
, arg0
);
8054 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
8055 case will be handled here. */
8056 if (integer_zerop (arg0
))
8057 return omit_one_operand (type
, arg0
, arg1
);
8059 /* !X && X is always false. */
8060 if (TREE_CODE (arg0
) == TRUTH_NOT_EXPR
8061 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
8062 return omit_one_operand (type
, integer_zero_node
, arg1
);
8063 /* X && !X is always false. */
8064 if (TREE_CODE (arg1
) == TRUTH_NOT_EXPR
8065 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
8066 return omit_one_operand (type
, integer_zero_node
, arg0
);
8068 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
8069 means A >= Y && A != MAX, but in this case we know that
8072 if (!TREE_SIDE_EFFECTS (arg0
)
8073 && !TREE_SIDE_EFFECTS (arg1
))
8075 tem
= fold_to_nonsharp_ineq_using_bound (arg0
, arg1
);
8077 return fold (build2 (code
, type
, tem
, arg1
));
8079 tem
= fold_to_nonsharp_ineq_using_bound (arg1
, arg0
);
8081 return fold (build2 (code
, type
, arg0
, tem
));
8085 /* We only do these simplifications if we are optimizing. */
8089 /* Check for things like (A || B) && (A || C). We can convert this
8090 to A || (B && C). Note that either operator can be any of the four
8091 truth and/or operations and the transformation will still be
8092 valid. Also note that we only care about order for the
8093 ANDIF and ORIF operators. If B contains side effects, this
8094 might change the truth-value of A. */
8095 if (TREE_CODE (arg0
) == TREE_CODE (arg1
)
8096 && (TREE_CODE (arg0
) == TRUTH_ANDIF_EXPR
8097 || TREE_CODE (arg0
) == TRUTH_ORIF_EXPR
8098 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
8099 || TREE_CODE (arg0
) == TRUTH_OR_EXPR
)
8100 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0
, 1)))
8102 tree a00
= TREE_OPERAND (arg0
, 0);
8103 tree a01
= TREE_OPERAND (arg0
, 1);
8104 tree a10
= TREE_OPERAND (arg1
, 0);
8105 tree a11
= TREE_OPERAND (arg1
, 1);
8106 int commutative
= ((TREE_CODE (arg0
) == TRUTH_OR_EXPR
8107 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
)
8108 && (code
== TRUTH_AND_EXPR
8109 || code
== TRUTH_OR_EXPR
));
8111 if (operand_equal_p (a00
, a10
, 0))
8112 return fold (build2 (TREE_CODE (arg0
), type
, a00
,
8113 fold (build2 (code
, type
, a01
, a11
))));
8114 else if (commutative
&& operand_equal_p (a00
, a11
, 0))
8115 return fold (build2 (TREE_CODE (arg0
), type
, a00
,
8116 fold (build2 (code
, type
, a01
, a10
))));
8117 else if (commutative
&& operand_equal_p (a01
, a10
, 0))
8118 return fold (build2 (TREE_CODE (arg0
), type
, a01
,
8119 fold (build2 (code
, type
, a00
, a11
))));
8121 /* This case if tricky because we must either have commutative
8122 operators or else A10 must not have side-effects. */
8124 else if ((commutative
|| ! TREE_SIDE_EFFECTS (a10
))
8125 && operand_equal_p (a01
, a11
, 0))
8126 return fold (build2 (TREE_CODE (arg0
), type
,
8127 fold (build2 (code
, type
, a00
, a10
)),
8131 /* See if we can build a range comparison. */
8132 if (0 != (tem
= fold_range_test (t
)))
8135 /* Check for the possibility of merging component references. If our
8136 lhs is another similar operation, try to merge its rhs with our
8137 rhs. Then try to merge our lhs and rhs. */
8138 if (TREE_CODE (arg0
) == code
8139 && 0 != (tem
= fold_truthop (code
, type
,
8140 TREE_OPERAND (arg0
, 1), arg1
)))
8141 return fold (build2 (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
8143 if ((tem
= fold_truthop (code
, type
, arg0
, arg1
)) != 0)
8148 case TRUTH_ORIF_EXPR
:
8149 /* Note that the operands of this must be ints
8150 and their values must be 0 or true.
8151 ("true" is a fixed value perhaps depending on the language.) */
8152 /* If first arg is constant true, return it. */
8153 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
8154 return fold_convert (type
, arg0
);
8156 /* If either arg is constant zero, drop it. */
8157 if (TREE_CODE (arg0
) == INTEGER_CST
&& integer_zerop (arg0
))
8158 return non_lvalue (fold_convert (type
, arg1
));
8159 if (TREE_CODE (arg1
) == INTEGER_CST
&& integer_zerop (arg1
)
8160 /* Preserve sequence points. */
8161 && (code
!= TRUTH_ORIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
8162 return non_lvalue (fold_convert (type
, arg0
));
8163 /* If second arg is constant true, result is true, but we must
8164 evaluate first arg. */
8165 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
))
8166 return omit_one_operand (type
, arg1
, arg0
);
8167 /* Likewise for first arg, but note this only occurs here for
8169 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
8170 return omit_one_operand (type
, arg0
, arg1
);
8172 /* !X || X is always true. */
8173 if (TREE_CODE (arg0
) == TRUTH_NOT_EXPR
8174 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
8175 return omit_one_operand (type
, integer_one_node
, arg1
);
8176 /* X || !X is always true. */
8177 if (TREE_CODE (arg1
) == TRUTH_NOT_EXPR
8178 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
8179 return omit_one_operand (type
, integer_one_node
, arg0
);
8183 case TRUTH_XOR_EXPR
:
8184 /* If the second arg is constant zero, drop it. */
8185 if (integer_zerop (arg1
))
8186 return non_lvalue (fold_convert (type
, arg0
));
8187 /* If the second arg is constant true, this is a logical inversion. */
8188 if (integer_onep (arg1
))
8189 return non_lvalue (fold_convert (type
, invert_truthvalue (arg0
)));
8190 /* Identical arguments cancel to zero. */
8191 if (operand_equal_p (arg0
, arg1
, 0))
8192 return omit_one_operand (type
, integer_zero_node
, arg0
);
8194 /* !X ^ X is always true. */
8195 if (TREE_CODE (arg0
) == TRUTH_NOT_EXPR
8196 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
8197 return omit_one_operand (type
, integer_one_node
, arg1
);
8199 /* X ^ !X is always true. */
8200 if (TREE_CODE (arg1
) == TRUTH_NOT_EXPR
8201 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
8202 return omit_one_operand (type
, integer_one_node
, arg0
);
8212 /* If one arg is a real or integer constant, put it last. */
8213 if (tree_swap_operands_p (arg0
, arg1
, true))
8214 return fold (build2 (swap_tree_comparison (code
), type
, arg1
, arg0
));
8216 /* If this is an equality comparison of the address of a non-weak
8217 object against zero, then we know the result. */
8218 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
8219 && TREE_CODE (arg0
) == ADDR_EXPR
8220 && DECL_P (TREE_OPERAND (arg0
, 0))
8221 && ! DECL_WEAK (TREE_OPERAND (arg0
, 0))
8222 && integer_zerop (arg1
))
8223 return constant_boolean_node (code
!= EQ_EXPR
, type
);
8225 /* If this is an equality comparison of the address of two non-weak,
8226 unaliased symbols neither of which are extern (since we do not
8227 have access to attributes for externs), then we know the result. */
8228 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
8229 && TREE_CODE (arg0
) == ADDR_EXPR
8230 && DECL_P (TREE_OPERAND (arg0
, 0))
8231 && ! DECL_WEAK (TREE_OPERAND (arg0
, 0))
8232 && ! lookup_attribute ("alias",
8233 DECL_ATTRIBUTES (TREE_OPERAND (arg0
, 0)))
8234 && ! DECL_EXTERNAL (TREE_OPERAND (arg0
, 0))
8235 && TREE_CODE (arg1
) == ADDR_EXPR
8236 && DECL_P (TREE_OPERAND (arg1
, 0))
8237 && ! DECL_WEAK (TREE_OPERAND (arg1
, 0))
8238 && ! lookup_attribute ("alias",
8239 DECL_ATTRIBUTES (TREE_OPERAND (arg1
, 0)))
8240 && ! DECL_EXTERNAL (TREE_OPERAND (arg1
, 0)))
8241 return constant_boolean_node (operand_equal_p (arg0
, arg1
, 0)
8242 ? code
== EQ_EXPR
: code
!= EQ_EXPR
,
8245 if (FLOAT_TYPE_P (TREE_TYPE (arg0
)))
8247 tree targ0
= strip_float_extensions (arg0
);
8248 tree targ1
= strip_float_extensions (arg1
);
8249 tree newtype
= TREE_TYPE (targ0
);
8251 if (TYPE_PRECISION (TREE_TYPE (targ1
)) > TYPE_PRECISION (newtype
))
8252 newtype
= TREE_TYPE (targ1
);
8254 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8255 if (TYPE_PRECISION (newtype
) < TYPE_PRECISION (TREE_TYPE (arg0
)))
8256 return fold (build2 (code
, type
, fold_convert (newtype
, targ0
),
8257 fold_convert (newtype
, targ1
)));
8259 /* (-a) CMP (-b) -> b CMP a */
8260 if (TREE_CODE (arg0
) == NEGATE_EXPR
8261 && TREE_CODE (arg1
) == NEGATE_EXPR
)
8262 return fold (build2 (code
, type
, TREE_OPERAND (arg1
, 0),
8263 TREE_OPERAND (arg0
, 0)));
8265 if (TREE_CODE (arg1
) == REAL_CST
)
8267 REAL_VALUE_TYPE cst
;
8268 cst
= TREE_REAL_CST (arg1
);
8270 /* (-a) CMP CST -> a swap(CMP) (-CST) */
8271 if (TREE_CODE (arg0
) == NEGATE_EXPR
)
8273 fold (build2 (swap_tree_comparison (code
), type
,
8274 TREE_OPERAND (arg0
, 0),
8275 build_real (TREE_TYPE (arg1
),
8276 REAL_VALUE_NEGATE (cst
))));
8278 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
8279 /* a CMP (-0) -> a CMP 0 */
8280 if (REAL_VALUE_MINUS_ZERO (cst
))
8281 return fold (build2 (code
, type
, arg0
,
8282 build_real (TREE_TYPE (arg1
), dconst0
)));
8284 /* x != NaN is always true, other ops are always false. */
8285 if (REAL_VALUE_ISNAN (cst
)
8286 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1
))))
8288 tem
= (code
== NE_EXPR
) ? integer_one_node
: integer_zero_node
;
8289 return omit_one_operand (type
, tem
, arg0
);
8292 /* Fold comparisons against infinity. */
8293 if (REAL_VALUE_ISINF (cst
))
8295 tem
= fold_inf_compare (code
, type
, arg0
, arg1
);
8296 if (tem
!= NULL_TREE
)
8301 /* If this is a comparison of a real constant with a PLUS_EXPR
8302 or a MINUS_EXPR of a real constant, we can convert it into a
8303 comparison with a revised real constant as long as no overflow
8304 occurs when unsafe_math_optimizations are enabled. */
8305 if (flag_unsafe_math_optimizations
8306 && TREE_CODE (arg1
) == REAL_CST
8307 && (TREE_CODE (arg0
) == PLUS_EXPR
8308 || TREE_CODE (arg0
) == MINUS_EXPR
)
8309 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == REAL_CST
8310 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
8311 ? MINUS_EXPR
: PLUS_EXPR
,
8312 arg1
, TREE_OPERAND (arg0
, 1), 0))
8313 && ! TREE_CONSTANT_OVERFLOW (tem
))
8314 return fold (build2 (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
8316 /* Likewise, we can simplify a comparison of a real constant with
8317 a MINUS_EXPR whose first operand is also a real constant, i.e.
8318 (c1 - x) < c2 becomes x > c1-c2. */
8319 if (flag_unsafe_math_optimizations
8320 && TREE_CODE (arg1
) == REAL_CST
8321 && TREE_CODE (arg0
) == MINUS_EXPR
8322 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == REAL_CST
8323 && 0 != (tem
= const_binop (MINUS_EXPR
, TREE_OPERAND (arg0
, 0),
8325 && ! TREE_CONSTANT_OVERFLOW (tem
))
8326 return fold (build2 (swap_tree_comparison (code
), type
,
8327 TREE_OPERAND (arg0
, 1), tem
));
8329 /* Fold comparisons against built-in math functions. */
8330 if (TREE_CODE (arg1
) == REAL_CST
8331 && flag_unsafe_math_optimizations
8332 && ! flag_errno_math
)
8334 enum built_in_function fcode
= builtin_mathfn_code (arg0
);
8336 if (fcode
!= END_BUILTINS
)
8338 tem
= fold_mathfn_compare (fcode
, code
, type
, arg0
, arg1
);
8339 if (tem
!= NULL_TREE
)
8345 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
8346 if (TREE_CONSTANT (arg1
)
8347 && (TREE_CODE (arg0
) == POSTINCREMENT_EXPR
8348 || TREE_CODE (arg0
) == POSTDECREMENT_EXPR
)
8349 /* This optimization is invalid for ordered comparisons
8350 if CONST+INCR overflows or if foo+incr might overflow.
8351 This optimization is invalid for floating point due to rounding.
8352 For pointer types we assume overflow doesn't happen. */
8353 && (POINTER_TYPE_P (TREE_TYPE (arg0
))
8354 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
8355 && (code
== EQ_EXPR
|| code
== NE_EXPR
))))
8357 tree varop
, newconst
;
8359 if (TREE_CODE (arg0
) == POSTINCREMENT_EXPR
)
8361 newconst
= fold (build2 (PLUS_EXPR
, TREE_TYPE (arg0
),
8362 arg1
, TREE_OPERAND (arg0
, 1)));
8363 varop
= build2 (PREINCREMENT_EXPR
, TREE_TYPE (arg0
),
8364 TREE_OPERAND (arg0
, 0),
8365 TREE_OPERAND (arg0
, 1));
8369 newconst
= fold (build2 (MINUS_EXPR
, TREE_TYPE (arg0
),
8370 arg1
, TREE_OPERAND (arg0
, 1)));
8371 varop
= build2 (PREDECREMENT_EXPR
, TREE_TYPE (arg0
),
8372 TREE_OPERAND (arg0
, 0),
8373 TREE_OPERAND (arg0
, 1));
8377 /* If VAROP is a reference to a bitfield, we must mask
8378 the constant by the width of the field. */
8379 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
8380 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop
, 0), 1))
8381 && host_integerp (DECL_SIZE (TREE_OPERAND
8382 (TREE_OPERAND (varop
, 0), 1)), 1))
8384 tree fielddecl
= TREE_OPERAND (TREE_OPERAND (varop
, 0), 1);
8385 HOST_WIDE_INT size
= tree_low_cst (DECL_SIZE (fielddecl
), 1);
8386 tree folded_compare
, shift
;
8388 /* First check whether the comparison would come out
8389 always the same. If we don't do that we would
8390 change the meaning with the masking. */
8391 folded_compare
= fold (build2 (code
, type
,
8392 TREE_OPERAND (varop
, 0), arg1
));
8393 if (integer_zerop (folded_compare
)
8394 || integer_onep (folded_compare
))
8395 return omit_one_operand (type
, folded_compare
, varop
);
8397 shift
= build_int_cst (NULL_TREE
,
8398 TYPE_PRECISION (TREE_TYPE (varop
)) - size
);
8399 shift
= fold_convert (TREE_TYPE (varop
), shift
);
8400 newconst
= fold (build2 (LSHIFT_EXPR
, TREE_TYPE (varop
),
8402 newconst
= fold (build2 (RSHIFT_EXPR
, TREE_TYPE (varop
),
8406 return fold (build2 (code
, type
, varop
, newconst
));
8409 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
8410 This transformation affects the cases which are handled in later
8411 optimizations involving comparisons with non-negative constants. */
8412 if (TREE_CODE (arg1
) == INTEGER_CST
8413 && TREE_CODE (arg0
) != INTEGER_CST
8414 && tree_int_cst_sgn (arg1
) > 0)
8419 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
8420 return fold (build2 (GT_EXPR
, type
, arg0
, arg1
));
8423 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
8424 return fold (build2 (LE_EXPR
, type
, arg0
, arg1
));
8431 /* Comparisons with the highest or lowest possible integer of
8432 the specified size will have known values.
8434 This is quite similar to fold_relational_hi_lo; however, my
8435 attempts to share the code have been nothing but trouble.
8436 I give up for now. */
8438 int width
= GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1
)));
8440 if (TREE_CODE (arg1
) == INTEGER_CST
8441 && ! TREE_CONSTANT_OVERFLOW (arg1
)
8442 && width
<= HOST_BITS_PER_WIDE_INT
8443 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
8444 || POINTER_TYPE_P (TREE_TYPE (arg1
))))
8446 unsigned HOST_WIDE_INT signed_max
;
8447 unsigned HOST_WIDE_INT max
, min
;
8449 signed_max
= ((unsigned HOST_WIDE_INT
) 1 << (width
- 1)) - 1;
8451 if (TYPE_UNSIGNED (TREE_TYPE (arg1
)))
8453 max
= ((unsigned HOST_WIDE_INT
) 2 << (width
- 1)) - 1;
8459 min
= ((unsigned HOST_WIDE_INT
) -1 << (width
- 1));
8462 if (TREE_INT_CST_HIGH (arg1
) == 0
8463 && TREE_INT_CST_LOW (arg1
) == max
)
8467 return omit_one_operand (type
, integer_zero_node
, arg0
);
8470 return fold (build2 (EQ_EXPR
, type
, arg0
, arg1
));
8473 return omit_one_operand (type
, integer_one_node
, arg0
);
8476 return fold (build2 (NE_EXPR
, type
, arg0
, arg1
));
8478 /* The GE_EXPR and LT_EXPR cases above are not normally
8479 reached because of previous transformations. */
8484 else if (TREE_INT_CST_HIGH (arg1
) == 0
8485 && TREE_INT_CST_LOW (arg1
) == max
- 1)
8489 arg1
= const_binop (PLUS_EXPR
, arg1
, integer_one_node
, 0);
8490 return fold (build2 (EQ_EXPR
, type
, arg0
, arg1
));
8492 arg1
= const_binop (PLUS_EXPR
, arg1
, integer_one_node
, 0);
8493 return fold (build2 (NE_EXPR
, type
, arg0
, arg1
));
8497 else if (TREE_INT_CST_HIGH (arg1
) == (min
? -1 : 0)
8498 && TREE_INT_CST_LOW (arg1
) == min
)
8502 return omit_one_operand (type
, integer_zero_node
, arg0
);
8505 return fold (build2 (EQ_EXPR
, type
, arg0
, arg1
));
8508 return omit_one_operand (type
, integer_one_node
, arg0
);
8511 return fold (build2 (NE_EXPR
, type
, arg0
, arg1
));
8516 else if (TREE_INT_CST_HIGH (arg1
) == (min
? -1 : 0)
8517 && TREE_INT_CST_LOW (arg1
) == min
+ 1)
8521 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
8522 return fold (build2 (NE_EXPR
, type
, arg0
, arg1
));
8524 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
8525 return fold (build2 (EQ_EXPR
, type
, arg0
, arg1
));
8530 else if (!in_gimple_form
8531 && TREE_INT_CST_HIGH (arg1
) == 0
8532 && TREE_INT_CST_LOW (arg1
) == signed_max
8533 && TYPE_UNSIGNED (TREE_TYPE (arg1
))
8534 /* signed_type does not work on pointer types. */
8535 && INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
8537 /* The following case also applies to X < signed_max+1
8538 and X >= signed_max+1 because previous transformations. */
8539 if (code
== LE_EXPR
|| code
== GT_EXPR
)
8542 st0
= lang_hooks
.types
.signed_type (TREE_TYPE (arg0
));
8543 st1
= lang_hooks
.types
.signed_type (TREE_TYPE (arg1
));
8545 (build2 (code
== LE_EXPR
? GE_EXPR
: LT_EXPR
,
8546 type
, fold_convert (st0
, arg0
),
8547 fold_convert (st1
, integer_zero_node
)));
8553 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
8554 a MINUS_EXPR of a constant, we can convert it into a comparison with
8555 a revised constant as long as no overflow occurs. */
8556 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
8557 && TREE_CODE (arg1
) == INTEGER_CST
8558 && (TREE_CODE (arg0
) == PLUS_EXPR
8559 || TREE_CODE (arg0
) == MINUS_EXPR
)
8560 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
8561 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
8562 ? MINUS_EXPR
: PLUS_EXPR
,
8563 arg1
, TREE_OPERAND (arg0
, 1), 0))
8564 && ! TREE_CONSTANT_OVERFLOW (tem
))
8565 return fold (build2 (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
8567 /* Similarly for a NEGATE_EXPR. */
8568 else if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
8569 && TREE_CODE (arg0
) == NEGATE_EXPR
8570 && TREE_CODE (arg1
) == INTEGER_CST
8571 && 0 != (tem
= negate_expr (arg1
))
8572 && TREE_CODE (tem
) == INTEGER_CST
8573 && ! TREE_CONSTANT_OVERFLOW (tem
))
8574 return fold (build2 (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
8576 /* If we have X - Y == 0, we can convert that to X == Y and similarly
8577 for !=. Don't do this for ordered comparisons due to overflow. */
8578 else if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
8579 && integer_zerop (arg1
) && TREE_CODE (arg0
) == MINUS_EXPR
)
8580 return fold (build2 (code
, type
,
8581 TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg0
, 1)));
8583 else if (TREE_CODE (TREE_TYPE (arg0
)) == INTEGER_TYPE
8584 && TREE_CODE (arg0
) == NOP_EXPR
)
8586 /* If we are widening one operand of an integer comparison,
8587 see if the other operand is similarly being widened. Perhaps we
8588 can do the comparison in the narrower type. */
8589 tem
= fold_widened_comparison (code
, type
, arg0
, arg1
);
8593 /* Or if we are changing signedness. */
8594 tem
= fold_sign_changed_comparison (code
, type
, arg0
, arg1
);
8599 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
8600 constant, we can simplify it. */
8601 else if (TREE_CODE (arg1
) == INTEGER_CST
8602 && (TREE_CODE (arg0
) == MIN_EXPR
8603 || TREE_CODE (arg0
) == MAX_EXPR
)
8604 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
8605 return optimize_minmax_comparison (t
);
8607 /* If we are comparing an ABS_EXPR with a constant, we can
8608 convert all the cases into explicit comparisons, but they may
8609 well not be faster than doing the ABS and one comparison.
8610 But ABS (X) <= C is a range comparison, which becomes a subtraction
8611 and a comparison, and is probably faster. */
8612 else if (code
== LE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
8613 && TREE_CODE (arg0
) == ABS_EXPR
8614 && ! TREE_SIDE_EFFECTS (arg0
)
8615 && (0 != (tem
= negate_expr (arg1
)))
8616 && TREE_CODE (tem
) == INTEGER_CST
8617 && ! TREE_CONSTANT_OVERFLOW (tem
))
8618 return fold (build2 (TRUTH_ANDIF_EXPR
, type
,
8619 build2 (GE_EXPR
, type
,
8620 TREE_OPERAND (arg0
, 0), tem
),
8621 build2 (LE_EXPR
, type
,
8622 TREE_OPERAND (arg0
, 0), arg1
)));
8624 /* If this is an EQ or NE comparison with zero and ARG0 is
8625 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
8626 two operations, but the latter can be done in one less insn
8627 on machines that have only two-operand insns or on which a
8628 constant cannot be the first operand. */
8629 if (integer_zerop (arg1
) && (code
== EQ_EXPR
|| code
== NE_EXPR
)
8630 && TREE_CODE (arg0
) == BIT_AND_EXPR
)
8632 tree arg00
= TREE_OPERAND (arg0
, 0);
8633 tree arg01
= TREE_OPERAND (arg0
, 1);
8634 if (TREE_CODE (arg00
) == LSHIFT_EXPR
8635 && integer_onep (TREE_OPERAND (arg00
, 0)))
8637 fold (build2 (code
, type
,
8638 build2 (BIT_AND_EXPR
, TREE_TYPE (arg0
),
8639 build2 (RSHIFT_EXPR
, TREE_TYPE (arg00
),
8640 arg01
, TREE_OPERAND (arg00
, 1)),
8641 fold_convert (TREE_TYPE (arg0
),
8644 else if (TREE_CODE (TREE_OPERAND (arg0
, 1)) == LSHIFT_EXPR
8645 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 1), 0)))
8647 fold (build2 (code
, type
,
8648 build2 (BIT_AND_EXPR
, TREE_TYPE (arg0
),
8649 build2 (RSHIFT_EXPR
, TREE_TYPE (arg01
),
8650 arg00
, TREE_OPERAND (arg01
, 1)),
8651 fold_convert (TREE_TYPE (arg0
),
8656 /* If this is an NE or EQ comparison of zero against the result of a
8657 signed MOD operation whose second operand is a power of 2, make
8658 the MOD operation unsigned since it is simpler and equivalent. */
8659 if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
8660 && integer_zerop (arg1
)
8661 && !TYPE_UNSIGNED (TREE_TYPE (arg0
))
8662 && (TREE_CODE (arg0
) == TRUNC_MOD_EXPR
8663 || TREE_CODE (arg0
) == CEIL_MOD_EXPR
8664 || TREE_CODE (arg0
) == FLOOR_MOD_EXPR
8665 || TREE_CODE (arg0
) == ROUND_MOD_EXPR
)
8666 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
8668 tree newtype
= lang_hooks
.types
.unsigned_type (TREE_TYPE (arg0
));
8669 tree newmod
= fold (build2 (TREE_CODE (arg0
), newtype
,
8670 fold_convert (newtype
,
8671 TREE_OPERAND (arg0
, 0)),
8672 fold_convert (newtype
,
8673 TREE_OPERAND (arg0
, 1))));
8675 return fold (build2 (code
, type
, newmod
,
8676 fold_convert (newtype
, arg1
)));
8679 /* If this is an NE comparison of zero with an AND of one, remove the
8680 comparison since the AND will give the correct value. */
8681 if (code
== NE_EXPR
&& integer_zerop (arg1
)
8682 && TREE_CODE (arg0
) == BIT_AND_EXPR
8683 && integer_onep (TREE_OPERAND (arg0
, 1)))
8684 return fold_convert (type
, arg0
);
8686 /* If we have (A & C) == C where C is a power of 2, convert this into
8687 (A & C) != 0. Similarly for NE_EXPR. */
8688 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
8689 && TREE_CODE (arg0
) == BIT_AND_EXPR
8690 && integer_pow2p (TREE_OPERAND (arg0
, 1))
8691 && operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
8692 return fold (build2 (code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
, type
,
8693 arg0
, fold_convert (TREE_TYPE (arg0
),
8694 integer_zero_node
)));
8696 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
8697 2, then fold the expression into shifts and logical operations. */
8698 tem
= fold_single_bit_test (code
, arg0
, arg1
, type
);
8702 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
8703 Similarly for NE_EXPR. */
8704 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
8705 && TREE_CODE (arg0
) == BIT_AND_EXPR
8706 && TREE_CODE (arg1
) == INTEGER_CST
8707 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
8709 tree notc
= fold (build1 (BIT_NOT_EXPR
,
8710 TREE_TYPE (TREE_OPERAND (arg0
, 1)),
8711 TREE_OPERAND (arg0
, 1)));
8712 tree dandnotc
= fold (build2 (BIT_AND_EXPR
, TREE_TYPE (arg0
),
8714 tree rslt
= code
== EQ_EXPR
? integer_zero_node
: integer_one_node
;
8715 if (integer_nonzerop (dandnotc
))
8716 return omit_one_operand (type
, rslt
, arg0
);
8719 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
8720 Similarly for NE_EXPR. */
8721 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
8722 && TREE_CODE (arg0
) == BIT_IOR_EXPR
8723 && TREE_CODE (arg1
) == INTEGER_CST
8724 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
8726 tree notd
= fold (build1 (BIT_NOT_EXPR
, TREE_TYPE (arg1
), arg1
));
8727 tree candnotd
= fold (build2 (BIT_AND_EXPR
, TREE_TYPE (arg0
),
8728 TREE_OPERAND (arg0
, 1), notd
));
8729 tree rslt
= code
== EQ_EXPR
? integer_zero_node
: integer_one_node
;
8730 if (integer_nonzerop (candnotd
))
8731 return omit_one_operand (type
, rslt
, arg0
);
8734 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
8735 and similarly for >= into !=. */
8736 if ((code
== LT_EXPR
|| code
== GE_EXPR
)
8737 && TYPE_UNSIGNED (TREE_TYPE (arg0
))
8738 && TREE_CODE (arg1
) == LSHIFT_EXPR
8739 && integer_onep (TREE_OPERAND (arg1
, 0)))
8740 return build2 (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
8741 build2 (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
8742 TREE_OPERAND (arg1
, 1)),
8743 fold_convert (TREE_TYPE (arg0
), integer_zero_node
));
8745 else if ((code
== LT_EXPR
|| code
== GE_EXPR
)
8746 && TYPE_UNSIGNED (TREE_TYPE (arg0
))
8747 && (TREE_CODE (arg1
) == NOP_EXPR
8748 || TREE_CODE (arg1
) == CONVERT_EXPR
)
8749 && TREE_CODE (TREE_OPERAND (arg1
, 0)) == LSHIFT_EXPR
8750 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0)))
8752 build2 (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
8753 fold_convert (TREE_TYPE (arg0
),
8754 build2 (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
8755 TREE_OPERAND (TREE_OPERAND (arg1
, 0),
8757 fold_convert (TREE_TYPE (arg0
), integer_zero_node
));
8759 /* Simplify comparison of something with itself. (For IEEE
8760 floating-point, we can only do some of these simplifications.) */
8761 if (operand_equal_p (arg0
, arg1
, 0))
8766 if (! FLOAT_TYPE_P (TREE_TYPE (arg0
))
8767 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
))))
8768 return constant_boolean_node (1, type
);
8773 if (! FLOAT_TYPE_P (TREE_TYPE (arg0
))
8774 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
))))
8775 return constant_boolean_node (1, type
);
8776 return fold (build2 (EQ_EXPR
, type
, arg0
, arg1
));
8779 /* For NE, we can only do this simplification if integer
8780 or we don't honor IEEE floating point NaNs. */
8781 if (FLOAT_TYPE_P (TREE_TYPE (arg0
))
8782 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
))))
8784 /* ... fall through ... */
8787 return constant_boolean_node (0, type
);
8793 /* If we are comparing an expression that just has comparisons
8794 of two integer values, arithmetic expressions of those comparisons,
8795 and constants, we can simplify it. There are only three cases
8796 to check: the two values can either be equal, the first can be
8797 greater, or the second can be greater. Fold the expression for
8798 those three values. Since each value must be 0 or 1, we have
8799 eight possibilities, each of which corresponds to the constant 0
8800 or 1 or one of the six possible comparisons.
8802 This handles common cases like (a > b) == 0 but also handles
8803 expressions like ((x > y) - (y > x)) > 0, which supposedly
8804 occur in macroized code. */
8806 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) != INTEGER_CST
)
8808 tree cval1
= 0, cval2
= 0;
8811 if (twoval_comparison_p (arg0
, &cval1
, &cval2
, &save_p
)
8812 /* Don't handle degenerate cases here; they should already
8813 have been handled anyway. */
8814 && cval1
!= 0 && cval2
!= 0
8815 && ! (TREE_CONSTANT (cval1
) && TREE_CONSTANT (cval2
))
8816 && TREE_TYPE (cval1
) == TREE_TYPE (cval2
)
8817 && INTEGRAL_TYPE_P (TREE_TYPE (cval1
))
8818 && TYPE_MAX_VALUE (TREE_TYPE (cval1
))
8819 && TYPE_MAX_VALUE (TREE_TYPE (cval2
))
8820 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1
)),
8821 TYPE_MAX_VALUE (TREE_TYPE (cval2
)), 0))
8823 tree maxval
= TYPE_MAX_VALUE (TREE_TYPE (cval1
));
8824 tree minval
= TYPE_MIN_VALUE (TREE_TYPE (cval1
));
8826 /* We can't just pass T to eval_subst in case cval1 or cval2
8827 was the same as ARG1. */
8830 = fold (build2 (code
, type
,
8831 eval_subst (arg0
, cval1
, maxval
,
8835 = fold (build2 (code
, type
,
8836 eval_subst (arg0
, cval1
, maxval
,
8840 = fold (build2 (code
, type
,
8841 eval_subst (arg0
, cval1
, minval
,
8845 /* All three of these results should be 0 or 1. Confirm they
8846 are. Then use those values to select the proper code
8849 if ((integer_zerop (high_result
)
8850 || integer_onep (high_result
))
8851 && (integer_zerop (equal_result
)
8852 || integer_onep (equal_result
))
8853 && (integer_zerop (low_result
)
8854 || integer_onep (low_result
)))
8856 /* Make a 3-bit mask with the high-order bit being the
8857 value for `>', the next for '=', and the low for '<'. */
8858 switch ((integer_onep (high_result
) * 4)
8859 + (integer_onep (equal_result
) * 2)
8860 + integer_onep (low_result
))
8864 return omit_one_operand (type
, integer_zero_node
, arg0
);
8885 return omit_one_operand (type
, integer_one_node
, arg0
);
8888 tem
= build2 (code
, type
, cval1
, cval2
);
8890 return save_expr (tem
);
8897 /* If this is a comparison of a field, we may be able to simplify it. */
8898 if (((TREE_CODE (arg0
) == COMPONENT_REF
8899 && lang_hooks
.can_use_bit_fields_p ())
8900 || TREE_CODE (arg0
) == BIT_FIELD_REF
)
8901 && (code
== EQ_EXPR
|| code
== NE_EXPR
)
8902 /* Handle the constant case even without -O
8903 to make sure the warnings are given. */
8904 && (optimize
|| TREE_CODE (arg1
) == INTEGER_CST
))
8906 t1
= optimize_bit_field_compare (code
, type
, arg0
, arg1
);
8911 /* If this is a comparison of complex values and either or both sides
8912 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
8913 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
8914 This may prevent needless evaluations. */
8915 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
8916 && TREE_CODE (TREE_TYPE (arg0
)) == COMPLEX_TYPE
8917 && (TREE_CODE (arg0
) == COMPLEX_EXPR
8918 || TREE_CODE (arg1
) == COMPLEX_EXPR
8919 || TREE_CODE (arg0
) == COMPLEX_CST
8920 || TREE_CODE (arg1
) == COMPLEX_CST
))
8922 tree subtype
= TREE_TYPE (TREE_TYPE (arg0
));
8923 tree real0
, imag0
, real1
, imag1
;
8925 arg0
= save_expr (arg0
);
8926 arg1
= save_expr (arg1
);
8927 real0
= fold (build1 (REALPART_EXPR
, subtype
, arg0
));
8928 imag0
= fold (build1 (IMAGPART_EXPR
, subtype
, arg0
));
8929 real1
= fold (build1 (REALPART_EXPR
, subtype
, arg1
));
8930 imag1
= fold (build1 (IMAGPART_EXPR
, subtype
, arg1
));
8932 return fold (build2 ((code
== EQ_EXPR
? TRUTH_ANDIF_EXPR
8935 fold (build2 (code
, type
, real0
, real1
)),
8936 fold (build2 (code
, type
, imag0
, imag1
))));
8939 /* Optimize comparisons of strlen vs zero to a compare of the
8940 first character of the string vs zero. To wit,
8941 strlen(ptr) == 0 => *ptr == 0
8942 strlen(ptr) != 0 => *ptr != 0
8943 Other cases should reduce to one of these two (or a constant)
8944 due to the return value of strlen being unsigned. */
8945 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
8946 && integer_zerop (arg1
)
8947 && TREE_CODE (arg0
) == CALL_EXPR
)
8949 tree fndecl
= get_callee_fndecl (arg0
);
8953 && DECL_BUILT_IN (fndecl
)
8954 && DECL_BUILT_IN_CLASS (fndecl
) != BUILT_IN_MD
8955 && DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STRLEN
8956 && (arglist
= TREE_OPERAND (arg0
, 1))
8957 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist
))) == POINTER_TYPE
8958 && ! TREE_CHAIN (arglist
))
8959 return fold (build2 (code
, type
,
8960 build1 (INDIRECT_REF
, char_type_node
,
8961 TREE_VALUE (arglist
)),
8962 fold_convert (char_type_node
,
8963 integer_zero_node
)));
8966 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
8967 into a single range test. */
8968 if (TREE_CODE (arg0
) == TRUNC_DIV_EXPR
8969 && TREE_CODE (arg1
) == INTEGER_CST
8970 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
8971 && !integer_zerop (TREE_OPERAND (arg0
, 1))
8972 && !TREE_OVERFLOW (TREE_OPERAND (arg0
, 1))
8973 && !TREE_OVERFLOW (arg1
))
8975 t1
= fold_div_compare (code
, type
, arg0
, arg1
);
8976 if (t1
!= NULL_TREE
)
8980 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
8981 && !TREE_SIDE_EFFECTS (arg0
)
8982 && integer_zerop (arg1
)
8983 && tree_expr_nonzero_p (arg0
))
8984 return constant_boolean_node (code
==NE_EXPR
, type
);
8986 t1
= fold_relational_const (code
, type
, arg0
, arg1
);
8987 return t1
== NULL_TREE
? t
: t1
;
8989 case UNORDERED_EXPR
:
8997 if (TREE_CODE (arg0
) == REAL_CST
&& TREE_CODE (arg1
) == REAL_CST
)
8999 t1
= fold_relational_const (code
, type
, arg0
, arg1
);
9000 if (t1
!= NULL_TREE
)
9004 /* If the first operand is NaN, the result is constant. */
9005 if (TREE_CODE (arg0
) == REAL_CST
9006 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0
))
9007 && (code
!= LTGT_EXPR
|| ! flag_trapping_math
))
9009 t1
= (code
== ORDERED_EXPR
|| code
== LTGT_EXPR
)
9012 return omit_one_operand (type
, t1
, arg1
);
9015 /* If the second operand is NaN, the result is constant. */
9016 if (TREE_CODE (arg1
) == REAL_CST
9017 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
))
9018 && (code
!= LTGT_EXPR
|| ! flag_trapping_math
))
9020 t1
= (code
== ORDERED_EXPR
|| code
== LTGT_EXPR
)
9023 return omit_one_operand (type
, t1
, arg0
);
9026 /* Simplify unordered comparison of something with itself. */
9027 if ((code
== UNLE_EXPR
|| code
== UNGE_EXPR
|| code
== UNEQ_EXPR
)
9028 && operand_equal_p (arg0
, arg1
, 0))
9029 return constant_boolean_node (1, type
);
9031 if (code
== LTGT_EXPR
9032 && !flag_trapping_math
9033 && operand_equal_p (arg0
, arg1
, 0))
9034 return constant_boolean_node (0, type
);
9036 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
9038 tree targ0
= strip_float_extensions (arg0
);
9039 tree targ1
= strip_float_extensions (arg1
);
9040 tree newtype
= TREE_TYPE (targ0
);
9042 if (TYPE_PRECISION (TREE_TYPE (targ1
)) > TYPE_PRECISION (newtype
))
9043 newtype
= TREE_TYPE (targ1
);
9045 if (TYPE_PRECISION (newtype
) < TYPE_PRECISION (TREE_TYPE (arg0
)))
9046 return fold (build2 (code
, type
, fold_convert (newtype
, targ0
),
9047 fold_convert (newtype
, targ1
)));
9053 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
9054 so all simple results must be passed through pedantic_non_lvalue. */
9055 if (TREE_CODE (arg0
) == INTEGER_CST
)
9057 tem
= TREE_OPERAND (t
, (integer_zerop (arg0
) ? 2 : 1));
9058 /* Only optimize constant conditions when the selected branch
9059 has the same type as the COND_EXPR. This avoids optimizing
9060 away "c ? x : throw", where the throw has a void type. */
9061 if (! VOID_TYPE_P (TREE_TYPE (tem
))
9062 || VOID_TYPE_P (type
))
9063 return pedantic_non_lvalue (tem
);
9066 if (operand_equal_p (arg1
, TREE_OPERAND (t
, 2), 0))
9067 return pedantic_omit_one_operand (type
, arg1
, arg0
);
9069 /* If we have A op B ? A : C, we may be able to convert this to a
9070 simpler expression, depending on the operation and the values
9071 of B and C. Signed zeros prevent all of these transformations,
9072 for reasons given above each one.
9074 Also try swapping the arguments and inverting the conditional. */
9075 if (COMPARISON_CLASS_P (arg0
)
9076 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
9077 arg1
, TREE_OPERAND (arg0
, 1))
9078 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1
))))
9080 tem
= fold_cond_expr_with_comparison (type
, arg0
,
9081 TREE_OPERAND (t
, 1),
9082 TREE_OPERAND (t
, 2));
9087 if (COMPARISON_CLASS_P (arg0
)
9088 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
9089 TREE_OPERAND (t
, 2),
9090 TREE_OPERAND (arg0
, 1))
9091 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (TREE_OPERAND (t
, 2)))))
9093 tem
= invert_truthvalue (arg0
);
9094 if (COMPARISON_CLASS_P (tem
))
9096 tem
= fold_cond_expr_with_comparison (type
, tem
,
9097 TREE_OPERAND (t
, 2),
9098 TREE_OPERAND (t
, 1));
9104 /* If the second operand is simpler than the third, swap them
9105 since that produces better jump optimization results. */
9106 if (tree_swap_operands_p (TREE_OPERAND (t
, 1),
9107 TREE_OPERAND (t
, 2), false))
9109 /* See if this can be inverted. If it can't, possibly because
9110 it was a floating-point inequality comparison, don't do
9112 tem
= invert_truthvalue (arg0
);
9114 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
9115 return fold (build3 (code
, type
, tem
,
9116 TREE_OPERAND (t
, 2), TREE_OPERAND (t
, 1)));
9119 /* Convert A ? 1 : 0 to simply A. */
9120 if (integer_onep (TREE_OPERAND (t
, 1))
9121 && integer_zerop (TREE_OPERAND (t
, 2))
9122 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
9123 call to fold will try to move the conversion inside
9124 a COND, which will recurse. In that case, the COND_EXPR
9125 is probably the best choice, so leave it alone. */
9126 && type
== TREE_TYPE (arg0
))
9127 return pedantic_non_lvalue (arg0
);
9129 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
9130 over COND_EXPR in cases such as floating point comparisons. */
9131 if (integer_zerop (TREE_OPERAND (t
, 1))
9132 && integer_onep (TREE_OPERAND (t
, 2))
9133 && truth_value_p (TREE_CODE (arg0
)))
9134 return pedantic_non_lvalue (fold_convert (type
,
9135 invert_truthvalue (arg0
)));
9137 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
9138 if (TREE_CODE (arg0
) == LT_EXPR
9139 && integer_zerop (TREE_OPERAND (arg0
, 1))
9140 && integer_zerop (TREE_OPERAND (t
, 2))
9141 && (tem
= sign_bit_p (TREE_OPERAND (arg0
, 0), arg1
)))
9142 return fold_convert (type
, fold (build2 (BIT_AND_EXPR
,
9143 TREE_TYPE (tem
), tem
, arg1
)));
9145 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
9146 already handled above. */
9147 if (TREE_CODE (arg0
) == BIT_AND_EXPR
9148 && integer_onep (TREE_OPERAND (arg0
, 1))
9149 && integer_zerop (TREE_OPERAND (t
, 2))
9150 && integer_pow2p (arg1
))
9152 tree tem
= TREE_OPERAND (arg0
, 0);
9154 if (TREE_CODE (tem
) == RSHIFT_EXPR
9155 && TREE_CODE (TREE_OPERAND (tem
, 1)) == INTEGER_CST
9156 && (unsigned HOST_WIDE_INT
) tree_log2 (arg1
) ==
9157 TREE_INT_CST_LOW (TREE_OPERAND (tem
, 1)))
9158 return fold (build2 (BIT_AND_EXPR
, type
,
9159 TREE_OPERAND (tem
, 0), arg1
));
9162 /* A & N ? N : 0 is simply A & N if N is a power of two. This
9163 is probably obsolete because the first operand should be a
9164 truth value (that's why we have the two cases above), but let's
9165 leave it in until we can confirm this for all front-ends. */
9166 if (integer_zerop (TREE_OPERAND (t
, 2))
9167 && TREE_CODE (arg0
) == NE_EXPR
9168 && integer_zerop (TREE_OPERAND (arg0
, 1))
9169 && integer_pow2p (arg1
)
9170 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == BIT_AND_EXPR
9171 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1),
9172 arg1
, OEP_ONLY_CONST
))
9173 return pedantic_non_lvalue (fold_convert (type
,
9174 TREE_OPERAND (arg0
, 0)));
9176 /* Convert A ? B : 0 into A && B if A and B are truth values. */
9177 if (integer_zerop (TREE_OPERAND (t
, 2))
9178 && truth_value_p (TREE_CODE (arg0
))
9179 && truth_value_p (TREE_CODE (arg1
)))
9180 return fold (build2 (TRUTH_ANDIF_EXPR
, type
, arg0
, arg1
));
9182 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
9183 if (integer_onep (TREE_OPERAND (t
, 2))
9184 && truth_value_p (TREE_CODE (arg0
))
9185 && truth_value_p (TREE_CODE (arg1
)))
9187 /* Only perform transformation if ARG0 is easily inverted. */
9188 tem
= invert_truthvalue (arg0
);
9189 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
9190 return fold (build2 (TRUTH_ORIF_EXPR
, type
, tem
, arg1
));
9193 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
9194 if (integer_zerop (arg1
)
9195 && truth_value_p (TREE_CODE (arg0
))
9196 && truth_value_p (TREE_CODE (TREE_OPERAND (t
, 2))))
9198 /* Only perform transformation if ARG0 is easily inverted. */
9199 tem
= invert_truthvalue (arg0
);
9200 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
9201 return fold (build2 (TRUTH_ANDIF_EXPR
, type
, tem
,
9202 TREE_OPERAND (t
, 2)));
9205 /* Convert A ? 1 : B into A || B if A and B are truth values. */
9206 if (integer_onep (arg1
)
9207 && truth_value_p (TREE_CODE (arg0
))
9208 && truth_value_p (TREE_CODE (TREE_OPERAND (t
, 2))))
9209 return fold (build2 (TRUTH_ORIF_EXPR
, type
, arg0
,
9210 TREE_OPERAND (t
, 2)));
9215 /* When pedantic, a compound expression can be neither an lvalue
9216 nor an integer constant expression. */
9217 if (TREE_SIDE_EFFECTS (arg0
) || TREE_CONSTANT (arg1
))
9219 /* Don't let (0, 0) be null pointer constant. */
9220 tem
= integer_zerop (arg1
) ? build1 (NOP_EXPR
, type
, arg1
)
9221 : fold_convert (type
, arg1
);
9222 return pedantic_non_lvalue (tem
);
9226 return build_complex (type
, arg0
, arg1
);
9230 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
9232 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
9233 return omit_one_operand (type
, TREE_OPERAND (arg0
, 0),
9234 TREE_OPERAND (arg0
, 1));
9235 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
9236 return TREE_REALPART (arg0
);
9237 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
9238 return fold (build2 (TREE_CODE (arg0
), type
,
9239 fold (build1 (REALPART_EXPR
, type
,
9240 TREE_OPERAND (arg0
, 0))),
9241 fold (build1 (REALPART_EXPR
, type
,
9242 TREE_OPERAND (arg0
, 1)))));
9246 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
9247 return fold_convert (type
, integer_zero_node
);
9248 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
9249 return omit_one_operand (type
, TREE_OPERAND (arg0
, 1),
9250 TREE_OPERAND (arg0
, 0));
9251 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
9252 return TREE_IMAGPART (arg0
);
9253 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
9254 return fold (build2 (TREE_CODE (arg0
), type
,
9255 fold (build1 (IMAGPART_EXPR
, type
,
9256 TREE_OPERAND (arg0
, 0))),
9257 fold (build1 (IMAGPART_EXPR
, type
,
9258 TREE_OPERAND (arg0
, 1)))));
9262 /* Check for a built-in function. */
9263 if (TREE_CODE (TREE_OPERAND (t
, 0)) == ADDR_EXPR
9264 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0))
9266 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (t
, 0), 0)))
9268 tree tmp
= fold_builtin (t
, false);
9276 } /* switch (code) */
9279 #ifdef ENABLE_FOLD_CHECKING
9282 static void fold_checksum_tree (tree
, struct md5_ctx
*, htab_t
);
9283 static void fold_check_failed (tree
, tree
);
9284 void print_fold_checksum (tree
);
9286 /* When --enable-checking=fold, compute a digest of expr before
9287 and after actual fold call to see if fold did not accidentally
9288 change original expr. */
9295 unsigned char checksum_before
[16], checksum_after
[16];
9298 ht
= htab_create (32, htab_hash_pointer
, htab_eq_pointer
, NULL
);
9299 md5_init_ctx (&ctx
);
9300 fold_checksum_tree (expr
, &ctx
, ht
);
9301 md5_finish_ctx (&ctx
, checksum_before
);
9304 ret
= fold_1 (expr
);
9306 md5_init_ctx (&ctx
);
9307 fold_checksum_tree (expr
, &ctx
, ht
);
9308 md5_finish_ctx (&ctx
, checksum_after
);
9311 if (memcmp (checksum_before
, checksum_after
, 16))
9312 fold_check_failed (expr
, ret
);
9318 print_fold_checksum (tree expr
)
9321 unsigned char checksum
[16], cnt
;
9324 ht
= htab_create (32, htab_hash_pointer
, htab_eq_pointer
, NULL
);
9325 md5_init_ctx (&ctx
);
9326 fold_checksum_tree (expr
, &ctx
, ht
);
9327 md5_finish_ctx (&ctx
, checksum
);
9329 for (cnt
= 0; cnt
< 16; ++cnt
)
9330 fprintf (stderr
, "%02x", checksum
[cnt
]);
9331 putc ('\n', stderr
);
9335 fold_check_failed (tree expr ATTRIBUTE_UNUSED
, tree ret ATTRIBUTE_UNUSED
)
9337 internal_error ("fold check: original tree changed by fold");
9341 fold_checksum_tree (tree expr
, struct md5_ctx
*ctx
, htab_t ht
)
9344 enum tree_code code
;
9345 char buf
[sizeof (struct tree_decl
)];
9348 gcc_assert ((sizeof (struct tree_exp
) + 5 * sizeof (tree
)
9349 <= sizeof (struct tree_decl
))
9350 && sizeof (struct tree_type
) <= sizeof (struct tree_decl
));
9353 slot
= htab_find_slot (ht
, expr
, INSERT
);
9357 code
= TREE_CODE (expr
);
9358 if (TREE_CODE_CLASS (code
) == tcc_declaration
9359 && DECL_ASSEMBLER_NAME_SET_P (expr
))
9361 /* Allow DECL_ASSEMBLER_NAME to be modified. */
9362 memcpy (buf
, expr
, tree_size (expr
));
9364 SET_DECL_ASSEMBLER_NAME (expr
, NULL
);
9366 else if (TREE_CODE_CLASS (code
) == tcc_type
9367 && (TYPE_POINTER_TO (expr
) || TYPE_REFERENCE_TO (expr
)
9368 || TYPE_CACHED_VALUES_P (expr
)))
9370 /* Allow these fields to be modified. */
9371 memcpy (buf
, expr
, tree_size (expr
));
9373 TYPE_POINTER_TO (expr
) = NULL
;
9374 TYPE_REFERENCE_TO (expr
) = NULL
;
9375 TYPE_CACHED_VALUES_P (expr
) = 0;
9376 TYPE_CACHED_VALUES (expr
) = NULL
;
9378 md5_process_bytes (expr
, tree_size (expr
), ctx
);
9379 fold_checksum_tree (TREE_TYPE (expr
), ctx
, ht
);
9380 if (TREE_CODE_CLASS (code
) != tcc_type
9381 && TREE_CODE_CLASS (code
) != tcc_declaration
)
9382 fold_checksum_tree (TREE_CHAIN (expr
), ctx
, ht
);
9383 switch (TREE_CODE_CLASS (code
))
9389 md5_process_bytes (TREE_STRING_POINTER (expr
),
9390 TREE_STRING_LENGTH (expr
), ctx
);
9393 fold_checksum_tree (TREE_REALPART (expr
), ctx
, ht
);
9394 fold_checksum_tree (TREE_IMAGPART (expr
), ctx
, ht
);
9397 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr
), ctx
, ht
);
9403 case tcc_exceptional
:
9407 fold_checksum_tree (TREE_PURPOSE (expr
), ctx
, ht
);
9408 fold_checksum_tree (TREE_VALUE (expr
), ctx
, ht
);
9411 for (i
= 0; i
< TREE_VEC_LENGTH (expr
); ++i
)
9412 fold_checksum_tree (TREE_VEC_ELT (expr
, i
), ctx
, ht
);
9418 case tcc_expression
:
9420 case tcc_comparison
:
9424 len
= first_rtl_op (code
);
9425 for (i
= 0; i
< len
; ++i
)
9426 fold_checksum_tree (TREE_OPERAND (expr
, i
), ctx
, ht
);
9428 case tcc_declaration
:
9429 fold_checksum_tree (DECL_SIZE (expr
), ctx
, ht
);
9430 fold_checksum_tree (DECL_SIZE_UNIT (expr
), ctx
, ht
);
9431 fold_checksum_tree (DECL_NAME (expr
), ctx
, ht
);
9432 fold_checksum_tree (DECL_CONTEXT (expr
), ctx
, ht
);
9433 fold_checksum_tree (DECL_ARGUMENTS (expr
), ctx
, ht
);
9434 fold_checksum_tree (DECL_RESULT_FLD (expr
), ctx
, ht
);
9435 fold_checksum_tree (DECL_INITIAL (expr
), ctx
, ht
);
9436 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr
), ctx
, ht
);
9437 fold_checksum_tree (DECL_SECTION_NAME (expr
), ctx
, ht
);
9438 fold_checksum_tree (DECL_ATTRIBUTES (expr
), ctx
, ht
);
9439 fold_checksum_tree (DECL_VINDEX (expr
), ctx
, ht
);
9442 if (TREE_CODE (expr
) == ENUMERAL_TYPE
)
9443 fold_checksum_tree (TYPE_VALUES (expr
), ctx
, ht
);
9444 fold_checksum_tree (TYPE_SIZE (expr
), ctx
, ht
);
9445 fold_checksum_tree (TYPE_SIZE_UNIT (expr
), ctx
, ht
);
9446 fold_checksum_tree (TYPE_ATTRIBUTES (expr
), ctx
, ht
);
9447 fold_checksum_tree (TYPE_NAME (expr
), ctx
, ht
);
9448 if (INTEGRAL_TYPE_P (expr
)
9449 || SCALAR_FLOAT_TYPE_P (expr
))
9451 fold_checksum_tree (TYPE_MIN_VALUE (expr
), ctx
, ht
);
9452 fold_checksum_tree (TYPE_MAX_VALUE (expr
), ctx
, ht
);
9454 fold_checksum_tree (TYPE_MAIN_VARIANT (expr
), ctx
, ht
);
9455 if (TREE_CODE (expr
) == RECORD_TYPE
9456 || TREE_CODE (expr
) == UNION_TYPE
9457 || TREE_CODE (expr
) == QUAL_UNION_TYPE
)
9458 fold_checksum_tree (TYPE_BINFO (expr
), ctx
, ht
);
9459 fold_checksum_tree (TYPE_CONTEXT (expr
), ctx
, ht
);
9468 /* Perform constant folding and related simplification of initializer
9469 expression EXPR. This behaves identically to "fold" but ignores
9470 potential run-time traps and exceptions that fold must preserve. */
9473 fold_initializer (tree expr
)
9475 int saved_signaling_nans
= flag_signaling_nans
;
9476 int saved_trapping_math
= flag_trapping_math
;
9477 int saved_trapv
= flag_trapv
;
9480 flag_signaling_nans
= 0;
9481 flag_trapping_math
= 0;
9484 result
= fold (expr
);
9486 flag_signaling_nans
= saved_signaling_nans
;
9487 flag_trapping_math
= saved_trapping_math
;
9488 flag_trapv
= saved_trapv
;
9493 /* Determine if first argument is a multiple of second argument. Return 0 if
9494 it is not, or we cannot easily determined it to be.
9496 An example of the sort of thing we care about (at this point; this routine
9497 could surely be made more general, and expanded to do what the *_DIV_EXPR's
9498 fold cases do now) is discovering that
9500 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
9506 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
9508 This code also handles discovering that
9510 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
9512 is a multiple of 8 so we don't have to worry about dealing with a
9515 Note that we *look* inside a SAVE_EXPR only to determine how it was
9516 calculated; it is not safe for fold to do much of anything else with the
9517 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
9518 at run time. For example, the latter example above *cannot* be implemented
9519 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
9520 evaluation time of the original SAVE_EXPR is not necessarily the same at
9521 the time the new expression is evaluated. The only optimization of this
9522 sort that would be valid is changing
9524 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
9528 SAVE_EXPR (I) * SAVE_EXPR (J)
9530 (where the same SAVE_EXPR (J) is used in the original and the
9531 transformed version). */
9534 multiple_of_p (tree type
, tree top
, tree bottom
)
9536 if (operand_equal_p (top
, bottom
, 0))
9539 if (TREE_CODE (type
) != INTEGER_TYPE
)
9542 switch (TREE_CODE (top
))
9545 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
9546 || multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
9550 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
9551 && multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
9554 if (TREE_CODE (TREE_OPERAND (top
, 1)) == INTEGER_CST
)
9558 op1
= TREE_OPERAND (top
, 1);
9559 /* const_binop may not detect overflow correctly,
9560 so check for it explicitly here. */
9561 if (TYPE_PRECISION (TREE_TYPE (size_one_node
))
9562 > TREE_INT_CST_LOW (op1
)
9563 && TREE_INT_CST_HIGH (op1
) == 0
9564 && 0 != (t1
= fold_convert (type
,
9565 const_binop (LSHIFT_EXPR
,
9568 && ! TREE_OVERFLOW (t1
))
9569 return multiple_of_p (type
, t1
, bottom
);
9574 /* Can't handle conversions from non-integral or wider integral type. */
9575 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top
, 0))) != INTEGER_TYPE
)
9576 || (TYPE_PRECISION (type
)
9577 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top
, 0)))))
9580 /* .. fall through ... */
9583 return multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
);
9586 if (TREE_CODE (bottom
) != INTEGER_CST
9587 || (TYPE_UNSIGNED (type
)
9588 && (tree_int_cst_sgn (top
) < 0
9589 || tree_int_cst_sgn (bottom
) < 0)))
9591 return integer_zerop (const_binop (TRUNC_MOD_EXPR
,
9599 /* Return true if `t' is known to be non-negative. */
9602 tree_expr_nonnegative_p (tree t
)
9604 switch (TREE_CODE (t
))
9610 return tree_int_cst_sgn (t
) >= 0;
9613 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t
));
9616 if (FLOAT_TYPE_P (TREE_TYPE (t
)))
9617 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
9618 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
9620 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
9621 both unsigned and at least 2 bits shorter than the result. */
9622 if (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
9623 && TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
9624 && TREE_CODE (TREE_OPERAND (t
, 1)) == NOP_EXPR
)
9626 tree inner1
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
9627 tree inner2
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0));
9628 if (TREE_CODE (inner1
) == INTEGER_TYPE
&& TYPE_UNSIGNED (inner1
)
9629 && TREE_CODE (inner2
) == INTEGER_TYPE
&& TYPE_UNSIGNED (inner2
))
9631 unsigned int prec
= MAX (TYPE_PRECISION (inner1
),
9632 TYPE_PRECISION (inner2
)) + 1;
9633 return prec
< TYPE_PRECISION (TREE_TYPE (t
));
9639 if (FLOAT_TYPE_P (TREE_TYPE (t
)))
9641 /* x * x for floating point x is always non-negative. */
9642 if (operand_equal_p (TREE_OPERAND (t
, 0), TREE_OPERAND (t
, 1), 0))
9644 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
9645 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
9648 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
9649 both unsigned and their total bits is shorter than the result. */
9650 if (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
9651 && TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
9652 && TREE_CODE (TREE_OPERAND (t
, 1)) == NOP_EXPR
)
9654 tree inner1
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
9655 tree inner2
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0));
9656 if (TREE_CODE (inner1
) == INTEGER_TYPE
&& TYPE_UNSIGNED (inner1
)
9657 && TREE_CODE (inner2
) == INTEGER_TYPE
&& TYPE_UNSIGNED (inner2
))
9658 return TYPE_PRECISION (inner1
) + TYPE_PRECISION (inner2
)
9659 < TYPE_PRECISION (TREE_TYPE (t
));
9663 case TRUNC_DIV_EXPR
:
9665 case FLOOR_DIV_EXPR
:
9666 case ROUND_DIV_EXPR
:
9667 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
9668 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
9670 case TRUNC_MOD_EXPR
:
9672 case FLOOR_MOD_EXPR
:
9673 case ROUND_MOD_EXPR
:
9674 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
9677 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
9678 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
9681 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1))
9682 || tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
9685 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
9686 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
9690 tree inner_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
9691 tree outer_type
= TREE_TYPE (t
);
9693 if (TREE_CODE (outer_type
) == REAL_TYPE
)
9695 if (TREE_CODE (inner_type
) == REAL_TYPE
)
9696 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
9697 if (TREE_CODE (inner_type
) == INTEGER_TYPE
)
9699 if (TYPE_UNSIGNED (inner_type
))
9701 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
9704 else if (TREE_CODE (outer_type
) == INTEGER_TYPE
)
9706 if (TREE_CODE (inner_type
) == REAL_TYPE
)
9707 return tree_expr_nonnegative_p (TREE_OPERAND (t
,0));
9708 if (TREE_CODE (inner_type
) == INTEGER_TYPE
)
9709 return TYPE_PRECISION (inner_type
) < TYPE_PRECISION (outer_type
)
9710 && TYPE_UNSIGNED (inner_type
);
9716 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1))
9717 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 2));
9719 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
9721 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
9722 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
9724 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
9725 || tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
9727 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
9729 return tree_expr_nonnegative_p (expr_last (TREE_OPERAND (t
, 1)));
9731 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
9732 case NON_LVALUE_EXPR
:
9733 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
9735 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
9739 tree temp
= TARGET_EXPR_SLOT (t
);
9740 t
= TARGET_EXPR_INITIAL (t
);
9742 /* If the initializer is non-void, then it's a normal expression
9743 that will be assigned to the slot. */
9744 if (!VOID_TYPE_P (t
))
9745 return tree_expr_nonnegative_p (t
);
9747 /* Otherwise, the initializer sets the slot in some way. One common
9748 way is an assignment statement at the end of the initializer. */
9751 if (TREE_CODE (t
) == BIND_EXPR
)
9752 t
= expr_last (BIND_EXPR_BODY (t
));
9753 else if (TREE_CODE (t
) == TRY_FINALLY_EXPR
9754 || TREE_CODE (t
) == TRY_CATCH_EXPR
)
9755 t
= expr_last (TREE_OPERAND (t
, 0));
9756 else if (TREE_CODE (t
) == STATEMENT_LIST
)
9761 if (TREE_CODE (t
) == MODIFY_EXPR
9762 && TREE_OPERAND (t
, 0) == temp
)
9763 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
9770 tree fndecl
= get_callee_fndecl (t
);
9771 tree arglist
= TREE_OPERAND (t
, 1);
9773 && DECL_BUILT_IN (fndecl
)
9774 && DECL_BUILT_IN_CLASS (fndecl
) != BUILT_IN_MD
)
9775 switch (DECL_FUNCTION_CODE (fndecl
))
9777 #define CASE_BUILTIN_F(BUILT_IN_FN) \
9778 case BUILT_IN_FN: case BUILT_IN_FN##F: case BUILT_IN_FN##L:
9779 #define CASE_BUILTIN_I(BUILT_IN_FN) \
9780 case BUILT_IN_FN: case BUILT_IN_FN##L: case BUILT_IN_FN##LL:
9782 CASE_BUILTIN_F (BUILT_IN_ACOS
)
9783 CASE_BUILTIN_F (BUILT_IN_ACOSH
)
9784 CASE_BUILTIN_F (BUILT_IN_CABS
)
9785 CASE_BUILTIN_F (BUILT_IN_COSH
)
9786 CASE_BUILTIN_F (BUILT_IN_ERFC
)
9787 CASE_BUILTIN_F (BUILT_IN_EXP
)
9788 CASE_BUILTIN_F (BUILT_IN_EXP10
)
9789 CASE_BUILTIN_F (BUILT_IN_EXP2
)
9790 CASE_BUILTIN_F (BUILT_IN_FABS
)
9791 CASE_BUILTIN_F (BUILT_IN_FDIM
)
9792 CASE_BUILTIN_F (BUILT_IN_FREXP
)
9793 CASE_BUILTIN_F (BUILT_IN_HYPOT
)
9794 CASE_BUILTIN_F (BUILT_IN_POW10
)
9795 CASE_BUILTIN_I (BUILT_IN_FFS
)
9796 CASE_BUILTIN_I (BUILT_IN_PARITY
)
9797 CASE_BUILTIN_I (BUILT_IN_POPCOUNT
)
9801 CASE_BUILTIN_F (BUILT_IN_SQRT
)
9802 /* sqrt(-0.0) is -0.0. */
9803 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t
))))
9805 return tree_expr_nonnegative_p (TREE_VALUE (arglist
));
9807 CASE_BUILTIN_F (BUILT_IN_ASINH
)
9808 CASE_BUILTIN_F (BUILT_IN_ATAN
)
9809 CASE_BUILTIN_F (BUILT_IN_ATANH
)
9810 CASE_BUILTIN_F (BUILT_IN_CBRT
)
9811 CASE_BUILTIN_F (BUILT_IN_CEIL
)
9812 CASE_BUILTIN_F (BUILT_IN_ERF
)
9813 CASE_BUILTIN_F (BUILT_IN_EXPM1
)
9814 CASE_BUILTIN_F (BUILT_IN_FLOOR
)
9815 CASE_BUILTIN_F (BUILT_IN_FMOD
)
9816 CASE_BUILTIN_F (BUILT_IN_LDEXP
)
9817 CASE_BUILTIN_F (BUILT_IN_LLRINT
)
9818 CASE_BUILTIN_F (BUILT_IN_LLROUND
)
9819 CASE_BUILTIN_F (BUILT_IN_LRINT
)
9820 CASE_BUILTIN_F (BUILT_IN_LROUND
)
9821 CASE_BUILTIN_F (BUILT_IN_MODF
)
9822 CASE_BUILTIN_F (BUILT_IN_NEARBYINT
)
9823 CASE_BUILTIN_F (BUILT_IN_POW
)
9824 CASE_BUILTIN_F (BUILT_IN_RINT
)
9825 CASE_BUILTIN_F (BUILT_IN_ROUND
)
9826 CASE_BUILTIN_F (BUILT_IN_SIGNBIT
)
9827 CASE_BUILTIN_F (BUILT_IN_SINH
)
9828 CASE_BUILTIN_F (BUILT_IN_TANH
)
9829 CASE_BUILTIN_F (BUILT_IN_TRUNC
)
9830 /* True if the 1st argument is nonnegative. */
9831 return tree_expr_nonnegative_p (TREE_VALUE (arglist
));
9833 CASE_BUILTIN_F (BUILT_IN_FMAX
)
9834 /* True if the 1st OR 2nd arguments are nonnegative. */
9835 return tree_expr_nonnegative_p (TREE_VALUE (arglist
))
9836 || tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist
)));
9838 CASE_BUILTIN_F (BUILT_IN_FMIN
)
9839 /* True if the 1st AND 2nd arguments are nonnegative. */
9840 return tree_expr_nonnegative_p (TREE_VALUE (arglist
))
9841 && tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist
)));
9843 CASE_BUILTIN_F (BUILT_IN_COPYSIGN
)
9844 /* True if the 2nd argument is nonnegative. */
9845 return tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist
)));
9849 #undef CASE_BUILTIN_F
9850 #undef CASE_BUILTIN_I
9854 /* ... fall through ... */
9857 if (truth_value_p (TREE_CODE (t
)))
9858 /* Truth values evaluate to 0 or 1, which is nonnegative. */
9862 /* We don't know sign of `t', so be conservative and return false. */
9866 /* Return true when T is an address and is known to be nonzero.
9867 For floating point we further ensure that T is not denormal.
9868 Similar logic is present in nonzero_address in rtlanal.h. */
9871 tree_expr_nonzero_p (tree t
)
9873 tree type
= TREE_TYPE (t
);
9875 /* Doing something useful for floating point would need more work. */
9876 if (!INTEGRAL_TYPE_P (type
) && !POINTER_TYPE_P (type
))
9879 switch (TREE_CODE (t
))
9882 if (!TYPE_UNSIGNED (type
) && !flag_wrapv
)
9883 return tree_expr_nonzero_p (TREE_OPERAND (t
, 0));
9886 /* We used to test for !integer_zerop here. This does not work correctly
9887 if TREE_CONSTANT_OVERFLOW (t). */
9888 return (TREE_INT_CST_LOW (t
) != 0
9889 || TREE_INT_CST_HIGH (t
) != 0);
9892 if (!TYPE_UNSIGNED (type
) && !flag_wrapv
)
9894 /* With the presence of negative values it is hard
9895 to say something. */
9896 if (!tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
9897 || !tree_expr_nonnegative_p (TREE_OPERAND (t
, 1)))
9899 /* One of operands must be positive and the other non-negative. */
9900 return (tree_expr_nonzero_p (TREE_OPERAND (t
, 0))
9901 || tree_expr_nonzero_p (TREE_OPERAND (t
, 1)));
9906 if (!TYPE_UNSIGNED (type
) && !flag_wrapv
)
9908 return (tree_expr_nonzero_p (TREE_OPERAND (t
, 0))
9909 && tree_expr_nonzero_p (TREE_OPERAND (t
, 1)));
9915 tree inner_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
9916 tree outer_type
= TREE_TYPE (t
);
9918 return (TYPE_PRECISION (inner_type
) >= TYPE_PRECISION (outer_type
)
9919 && tree_expr_nonzero_p (TREE_OPERAND (t
, 0)));
9925 tree base
= get_base_address (TREE_OPERAND (t
, 0));
9930 /* Weak declarations may link to NULL. */
9932 return !DECL_WEAK (base
);
9934 /* Constants are never weak. */
9935 if (CONSTANT_CLASS_P (base
))
9942 return (tree_expr_nonzero_p (TREE_OPERAND (t
, 1))
9943 && tree_expr_nonzero_p (TREE_OPERAND (t
, 2)));
9946 return (tree_expr_nonzero_p (TREE_OPERAND (t
, 0))
9947 && tree_expr_nonzero_p (TREE_OPERAND (t
, 1)));
9950 if (tree_expr_nonzero_p (TREE_OPERAND (t
, 0)))
9952 /* When both operands are nonzero, then MAX must be too. */
9953 if (tree_expr_nonzero_p (TREE_OPERAND (t
, 1)))
9956 /* MAX where operand 0 is positive is positive. */
9957 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
9959 /* MAX where operand 1 is positive is positive. */
9960 else if (tree_expr_nonzero_p (TREE_OPERAND (t
, 1))
9961 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1)))
9968 return tree_expr_nonzero_p (TREE_OPERAND (t
, 1));
9971 case NON_LVALUE_EXPR
:
9972 return tree_expr_nonzero_p (TREE_OPERAND (t
, 0));
9975 return tree_expr_nonzero_p (TREE_OPERAND (t
, 1))
9976 || tree_expr_nonzero_p (TREE_OPERAND (t
, 0));
9984 /* See if we are applying CODE, a relational to the highest or lowest
9985 possible integer of TYPE. If so, then the result is a compile
9989 fold_relational_hi_lo (enum tree_code
*code_p
, const tree type
, tree
*op0_p
,
9994 enum tree_code code
= *code_p
;
9995 int width
= GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (op1
)));
9997 if (TREE_CODE (op1
) == INTEGER_CST
9998 && ! TREE_CONSTANT_OVERFLOW (op1
)
9999 && width
<= HOST_BITS_PER_WIDE_INT
10000 && (INTEGRAL_TYPE_P (TREE_TYPE (op1
))
10001 || POINTER_TYPE_P (TREE_TYPE (op1
))))
10003 unsigned HOST_WIDE_INT signed_max
;
10004 unsigned HOST_WIDE_INT max
, min
;
10006 signed_max
= ((unsigned HOST_WIDE_INT
) 1 << (width
- 1)) - 1;
10008 if (TYPE_UNSIGNED (TREE_TYPE (op1
)))
10010 max
= ((unsigned HOST_WIDE_INT
) 2 << (width
- 1)) - 1;
10016 min
= ((unsigned HOST_WIDE_INT
) -1 << (width
- 1));
10019 if (TREE_INT_CST_HIGH (op1
) == 0
10020 && TREE_INT_CST_LOW (op1
) == max
)
10024 return omit_one_operand (type
, integer_zero_node
, op0
);
10030 return omit_one_operand (type
, integer_one_node
, op0
);
10036 /* The GE_EXPR and LT_EXPR cases above are not normally
10037 reached because of previous transformations. */
10042 else if (TREE_INT_CST_HIGH (op1
) == 0
10043 && TREE_INT_CST_LOW (op1
) == max
- 1)
10048 *op1_p
= const_binop (PLUS_EXPR
, op1
, integer_one_node
, 0);
10052 *op1_p
= const_binop (PLUS_EXPR
, op1
, integer_one_node
, 0);
10057 else if (TREE_INT_CST_HIGH (op1
) == (min
? -1 : 0)
10058 && TREE_INT_CST_LOW (op1
) == min
)
10062 return omit_one_operand (type
, integer_zero_node
, op0
);
10069 return omit_one_operand (type
, integer_one_node
, op0
);
10078 else if (TREE_INT_CST_HIGH (op1
) == (min
? -1 : 0)
10079 && TREE_INT_CST_LOW (op1
) == min
+ 1)
10084 *op1_p
= const_binop (MINUS_EXPR
, op1
, integer_one_node
, 0);
10088 *op1_p
= const_binop (MINUS_EXPR
, op1
, integer_one_node
, 0);
10094 else if (TREE_INT_CST_HIGH (op1
) == 0
10095 && TREE_INT_CST_LOW (op1
) == signed_max
10096 && TYPE_UNSIGNED (TREE_TYPE (op1
))
10097 /* signed_type does not work on pointer types. */
10098 && INTEGRAL_TYPE_P (TREE_TYPE (op1
)))
10100 /* The following case also applies to X < signed_max+1
10101 and X >= signed_max+1 because previous transformations. */
10102 if (code
== LE_EXPR
|| code
== GT_EXPR
)
10104 tree st0
, st1
, exp
, retval
;
10105 st0
= lang_hooks
.types
.signed_type (TREE_TYPE (op0
));
10106 st1
= lang_hooks
.types
.signed_type (TREE_TYPE (op1
));
10108 exp
= build2 (code
== LE_EXPR
? GE_EXPR
: LT_EXPR
,
10110 fold_convert (st0
, op0
),
10111 fold_convert (st1
, integer_zero_node
));
10113 retval
= fold_binary_to_constant (TREE_CODE (exp
),
10115 TREE_OPERAND (exp
, 0),
10116 TREE_OPERAND (exp
, 1));
10118 /* If we are in gimple form, then returning EXP would create
10119 non-gimple expressions. Clearing it is safe and insures
10120 we do not allow a non-gimple expression to escape. */
10121 if (in_gimple_form
)
10124 return (retval
? retval
: exp
);
10133 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
10134 attempt to fold the expression to a constant without modifying TYPE,
10137 If the expression could be simplified to a constant, then return
10138 the constant. If the expression would not be simplified to a
10139 constant, then return NULL_TREE.
10141 Note this is primarily designed to be called after gimplification
10142 of the tree structures and when at least one operand is a constant.
10143 As a result of those simplifying assumptions this routine is far
10144 simpler than the generic fold routine. */
10147 fold_binary_to_constant (enum tree_code code
, tree type
, tree op0
, tree op1
)
10154 /* If this is a commutative operation, and ARG0 is a constant, move it
10155 to ARG1 to reduce the number of tests below. */
10156 if (commutative_tree_code (code
)
10157 && (TREE_CODE (op0
) == INTEGER_CST
|| TREE_CODE (op0
) == REAL_CST
))
10164 /* If either operand is a complex type, extract its real component. */
10165 if (TREE_CODE (op0
) == COMPLEX_CST
)
10166 subop0
= TREE_REALPART (op0
);
10170 if (TREE_CODE (op1
) == COMPLEX_CST
)
10171 subop1
= TREE_REALPART (op1
);
10175 /* Note if either argument is not a real or integer constant.
10176 With a few exceptions, simplification is limited to cases
10177 where both arguments are constants. */
10178 if ((TREE_CODE (subop0
) != INTEGER_CST
10179 && TREE_CODE (subop0
) != REAL_CST
)
10180 || (TREE_CODE (subop1
) != INTEGER_CST
10181 && TREE_CODE (subop1
) != REAL_CST
))
10187 /* (plus (address) (const_int)) is a constant. */
10188 if (TREE_CODE (op0
) == PLUS_EXPR
10189 && TREE_CODE (op1
) == INTEGER_CST
10190 && (TREE_CODE (TREE_OPERAND (op0
, 0)) == ADDR_EXPR
10191 || (TREE_CODE (TREE_OPERAND (op0
, 0)) == NOP_EXPR
10192 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (op0
, 0), 0))
10194 && TREE_CODE (TREE_OPERAND (op0
, 1)) == INTEGER_CST
)
10196 return build2 (PLUS_EXPR
, type
, TREE_OPERAND (op0
, 0),
10197 const_binop (PLUS_EXPR
, op1
,
10198 TREE_OPERAND (op0
, 1), 0));
10206 /* Both arguments are constants. Simplify. */
10207 tem
= const_binop (code
, op0
, op1
, 0);
10208 if (tem
!= NULL_TREE
)
10210 /* The return value should always have the same type as
10211 the original expression. */
10212 if (TREE_TYPE (tem
) != type
)
10213 tem
= fold_convert (type
, tem
);
10220 /* Fold &x - &x. This can happen from &x.foo - &x.
10221 This is unsafe for certain floats even in non-IEEE formats.
10222 In IEEE, it is unsafe because it does wrong for NaNs.
10223 Also note that operand_equal_p is always false if an
10224 operand is volatile. */
10225 if (! FLOAT_TYPE_P (type
) && operand_equal_p (op0
, op1
, 0))
10226 return fold_convert (type
, integer_zero_node
);
10232 /* Special case multiplication or bitwise AND where one argument
10234 if (! FLOAT_TYPE_P (type
) && integer_zerop (op1
))
10235 return omit_one_operand (type
, op1
, op0
);
10237 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (op0
)))
10238 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op0
)))
10239 && real_zerop (op1
))
10240 return omit_one_operand (type
, op1
, op0
);
10245 /* Special case when we know the result will be all ones. */
10246 if (integer_all_onesp (op1
))
10247 return omit_one_operand (type
, op1
, op0
);
10251 case TRUNC_DIV_EXPR
:
10252 case ROUND_DIV_EXPR
:
10253 case FLOOR_DIV_EXPR
:
10254 case CEIL_DIV_EXPR
:
10255 case EXACT_DIV_EXPR
:
10256 case TRUNC_MOD_EXPR
:
10257 case ROUND_MOD_EXPR
:
10258 case FLOOR_MOD_EXPR
:
10259 case CEIL_MOD_EXPR
:
10261 /* Division by zero is undefined. */
10262 if (integer_zerop (op1
))
10265 if (TREE_CODE (op1
) == REAL_CST
10266 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (op1
)))
10267 && real_zerop (op1
))
10273 if (INTEGRAL_TYPE_P (type
)
10274 && operand_equal_p (op1
, TYPE_MIN_VALUE (type
), OEP_ONLY_CONST
))
10275 return omit_one_operand (type
, op1
, op0
);
10280 if (INTEGRAL_TYPE_P (type
)
10281 && TYPE_MAX_VALUE (type
)
10282 && operand_equal_p (op1
, TYPE_MAX_VALUE (type
), OEP_ONLY_CONST
))
10283 return omit_one_operand (type
, op1
, op0
);
10288 /* Optimize -1 >> x for arithmetic right shifts. */
10289 if (integer_all_onesp (op0
) && ! TYPE_UNSIGNED (type
))
10290 return omit_one_operand (type
, op0
, op1
);
10291 /* ... fall through ... */
10294 if (integer_zerop (op0
))
10295 return omit_one_operand (type
, op0
, op1
);
10297 /* Since negative shift count is not well-defined, don't
10298 try to compute it in the compiler. */
10299 if (TREE_CODE (op1
) == INTEGER_CST
&& tree_int_cst_sgn (op1
) < 0)
10306 /* -1 rotated either direction by any amount is still -1. */
10307 if (integer_all_onesp (op0
))
10308 return omit_one_operand (type
, op0
, op1
);
10310 /* 0 rotated either direction by any amount is still zero. */
10311 if (integer_zerop (op0
))
10312 return omit_one_operand (type
, op0
, op1
);
10318 return build_complex (type
, op0
, op1
);
10327 /* If one arg is a real or integer constant, put it last. */
10328 if ((TREE_CODE (op0
) == INTEGER_CST
10329 && TREE_CODE (op1
) != INTEGER_CST
)
10330 || (TREE_CODE (op0
) == REAL_CST
10331 && TREE_CODE (op0
) != REAL_CST
))
10338 code
= swap_tree_comparison (code
);
10341 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
10342 This transformation affects the cases which are handled in later
10343 optimizations involving comparisons with non-negative constants. */
10344 if (TREE_CODE (op1
) == INTEGER_CST
10345 && TREE_CODE (op0
) != INTEGER_CST
10346 && tree_int_cst_sgn (op1
) > 0)
10352 op1
= const_binop (MINUS_EXPR
, op1
, integer_one_node
, 0);
10357 op1
= const_binop (MINUS_EXPR
, op1
, integer_one_node
, 0);
10365 tem
= fold_relational_hi_lo (&code
, type
, &op0
, &op1
);
10369 /* Fall through. */
10372 case UNORDERED_EXPR
:
10382 return fold_relational_const (code
, type
, op0
, op1
);
10385 /* This could probably be handled. */
10388 case TRUTH_AND_EXPR
:
10389 /* If second arg is constant zero, result is zero, but first arg
10390 must be evaluated. */
10391 if (integer_zerop (op1
))
10392 return omit_one_operand (type
, op1
, op0
);
10393 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
10394 case will be handled here. */
10395 if (integer_zerop (op0
))
10396 return omit_one_operand (type
, op0
, op1
);
10397 if (TREE_CODE (op0
) == INTEGER_CST
&& TREE_CODE (op1
) == INTEGER_CST
)
10398 return constant_boolean_node (true, type
);
10401 case TRUTH_OR_EXPR
:
10402 /* If second arg is constant true, result is true, but we must
10403 evaluate first arg. */
10404 if (TREE_CODE (op1
) == INTEGER_CST
&& ! integer_zerop (op1
))
10405 return omit_one_operand (type
, op1
, op0
);
10406 /* Likewise for first arg, but note this only occurs here for
10408 if (TREE_CODE (op0
) == INTEGER_CST
&& ! integer_zerop (op0
))
10409 return omit_one_operand (type
, op0
, op1
);
10410 if (TREE_CODE (op0
) == INTEGER_CST
&& TREE_CODE (op1
) == INTEGER_CST
)
10411 return constant_boolean_node (false, type
);
10414 case TRUTH_XOR_EXPR
:
10415 if (TREE_CODE (op0
) == INTEGER_CST
&& TREE_CODE (op1
) == INTEGER_CST
)
10417 int x
= ! integer_zerop (op0
) ^ ! integer_zerop (op1
);
10418 return constant_boolean_node (x
, type
);
10427 /* Given the components of a unary expression CODE, TYPE and OP0,
10428 attempt to fold the expression to a constant without modifying
10431 If the expression could be simplified to a constant, then return
10432 the constant. If the expression would not be simplified to a
10433 constant, then return NULL_TREE.
10435 Note this is primarily designed to be called after gimplification
10436 of the tree structures and when op0 is a constant. As a result
10437 of those simplifying assumptions this routine is far simpler than
10438 the generic fold routine. */
10441 fold_unary_to_constant (enum tree_code code
, tree type
, tree op0
)
10443 /* Make sure we have a suitable constant argument. */
10444 if (code
== NOP_EXPR
|| code
== FLOAT_EXPR
|| code
== CONVERT_EXPR
)
10448 if (TREE_CODE (op0
) == COMPLEX_CST
)
10449 subop
= TREE_REALPART (op0
);
10453 if (TREE_CODE (subop
) != INTEGER_CST
&& TREE_CODE (subop
) != REAL_CST
)
10462 case FIX_TRUNC_EXPR
:
10463 case FIX_FLOOR_EXPR
:
10464 case FIX_CEIL_EXPR
:
10465 return fold_convert_const (code
, type
, op0
);
10468 if (TREE_CODE (op0
) == INTEGER_CST
|| TREE_CODE (op0
) == REAL_CST
)
10469 return fold_negate_const (op0
, type
);
10474 if (TREE_CODE (op0
) == INTEGER_CST
|| TREE_CODE (op0
) == REAL_CST
)
10475 return fold_abs_const (op0
, type
);
10480 if (TREE_CODE (op0
) == INTEGER_CST
)
10481 return fold_not_const (op0
, type
);
10485 case REALPART_EXPR
:
10486 if (TREE_CODE (op0
) == COMPLEX_CST
)
10487 return TREE_REALPART (op0
);
10491 case IMAGPART_EXPR
:
10492 if (TREE_CODE (op0
) == COMPLEX_CST
)
10493 return TREE_IMAGPART (op0
);
10498 if (TREE_CODE (op0
) == COMPLEX_CST
10499 && TREE_CODE (TREE_TYPE (op0
)) == COMPLEX_TYPE
)
10500 return build_complex (type
, TREE_REALPART (op0
),
10501 negate_expr (TREE_IMAGPART (op0
)));
10509 /* If EXP represents referencing an element in a constant string
10510 (either via pointer arithmetic or array indexing), return the
10511 tree representing the value accessed, otherwise return NULL. */
10514 fold_read_from_constant_string (tree exp
)
10516 if (TREE_CODE (exp
) == INDIRECT_REF
|| TREE_CODE (exp
) == ARRAY_REF
)
10518 tree exp1
= TREE_OPERAND (exp
, 0);
10522 if (TREE_CODE (exp
) == INDIRECT_REF
)
10523 string
= string_constant (exp1
, &index
);
10526 tree low_bound
= array_ref_low_bound (exp
);
10527 index
= fold_convert (sizetype
, TREE_OPERAND (exp
, 1));
10529 /* Optimize the special-case of a zero lower bound.
10531 We convert the low_bound to sizetype to avoid some problems
10532 with constant folding. (E.g. suppose the lower bound is 1,
10533 and its mode is QI. Without the conversion,l (ARRAY
10534 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
10535 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
10536 if (! integer_zerop (low_bound
))
10537 index
= size_diffop (index
, fold_convert (sizetype
, low_bound
));
10543 && TREE_TYPE (exp
) == TREE_TYPE (TREE_TYPE (string
))
10544 && TREE_CODE (string
) == STRING_CST
10545 && TREE_CODE (index
) == INTEGER_CST
10546 && compare_tree_int (index
, TREE_STRING_LENGTH (string
)) < 0
10547 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string
))))
10549 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string
)))) == 1))
10550 return fold_convert (TREE_TYPE (exp
),
10551 build_int_cst (NULL_TREE
,
10552 (TREE_STRING_POINTER (string
)
10553 [TREE_INT_CST_LOW (index
)])));
10558 /* Return the tree for neg (ARG0) when ARG0 is known to be either
10559 an integer constant or real constant.
10561 TYPE is the type of the result. */
10564 fold_negate_const (tree arg0
, tree type
)
10566 tree t
= NULL_TREE
;
10568 switch (TREE_CODE (arg0
))
10572 unsigned HOST_WIDE_INT low
;
10573 HOST_WIDE_INT high
;
10574 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
10575 TREE_INT_CST_HIGH (arg0
),
10577 t
= build_int_cst_wide (type
, low
, high
);
10578 t
= force_fit_type (t
, 1,
10579 (overflow
| TREE_OVERFLOW (arg0
))
10580 && !TYPE_UNSIGNED (type
),
10581 TREE_CONSTANT_OVERFLOW (arg0
));
10586 t
= build_real (type
, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
10590 gcc_unreachable ();
10596 /* Return the tree for abs (ARG0) when ARG0 is known to be either
10597 an integer constant or real constant.
10599 TYPE is the type of the result. */
10602 fold_abs_const (tree arg0
, tree type
)
10604 tree t
= NULL_TREE
;
10606 switch (TREE_CODE (arg0
))
10609 /* If the value is unsigned, then the absolute value is
10610 the same as the ordinary value. */
10611 if (TYPE_UNSIGNED (type
))
10613 /* Similarly, if the value is non-negative. */
10614 else if (INT_CST_LT (integer_minus_one_node
, arg0
))
10616 /* If the value is negative, then the absolute value is
10620 unsigned HOST_WIDE_INT low
;
10621 HOST_WIDE_INT high
;
10622 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
10623 TREE_INT_CST_HIGH (arg0
),
10625 t
= build_int_cst_wide (type
, low
, high
);
10626 t
= force_fit_type (t
, -1, overflow
| TREE_OVERFLOW (arg0
),
10627 TREE_CONSTANT_OVERFLOW (arg0
));
10632 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0
)))
10633 t
= build_real (type
, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
10639 gcc_unreachable ();
10645 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
10646 constant. TYPE is the type of the result. */
10649 fold_not_const (tree arg0
, tree type
)
10651 tree t
= NULL_TREE
;
10653 gcc_assert (TREE_CODE (arg0
) == INTEGER_CST
);
10655 t
= build_int_cst_wide (type
,
10656 ~ TREE_INT_CST_LOW (arg0
),
10657 ~ TREE_INT_CST_HIGH (arg0
));
10658 t
= force_fit_type (t
, 0, TREE_OVERFLOW (arg0
),
10659 TREE_CONSTANT_OVERFLOW (arg0
));
10664 /* Given CODE, a relational operator, the target type, TYPE and two
10665 constant operands OP0 and OP1, return the result of the
10666 relational operation. If the result is not a compile time
10667 constant, then return NULL_TREE. */
10670 fold_relational_const (enum tree_code code
, tree type
, tree op0
, tree op1
)
10672 int result
, invert
;
10674 /* From here on, the only cases we handle are when the result is
10675 known to be a constant. */
10677 if (TREE_CODE (op0
) == REAL_CST
&& TREE_CODE (op1
) == REAL_CST
)
10679 const REAL_VALUE_TYPE
*c0
= TREE_REAL_CST_PTR (op0
);
10680 const REAL_VALUE_TYPE
*c1
= TREE_REAL_CST_PTR (op1
);
10682 /* Handle the cases where either operand is a NaN. */
10683 if (real_isnan (c0
) || real_isnan (c1
))
10693 case UNORDERED_EXPR
:
10707 if (flag_trapping_math
)
10713 gcc_unreachable ();
10716 return constant_boolean_node (result
, type
);
10719 return constant_boolean_node (real_compare (code
, c0
, c1
), type
);
10722 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
10724 To compute GT, swap the arguments and do LT.
10725 To compute GE, do LT and invert the result.
10726 To compute LE, swap the arguments, do LT and invert the result.
10727 To compute NE, do EQ and invert the result.
10729 Therefore, the code below must handle only EQ and LT. */
10731 if (code
== LE_EXPR
|| code
== GT_EXPR
)
10736 code
= swap_tree_comparison (code
);
10739 /* Note that it is safe to invert for real values here because we
10740 have already handled the one case that it matters. */
10743 if (code
== NE_EXPR
|| code
== GE_EXPR
)
10746 code
= invert_tree_comparison (code
, false);
10749 /* Compute a result for LT or EQ if args permit;
10750 Otherwise return T. */
10751 if (TREE_CODE (op0
) == INTEGER_CST
&& TREE_CODE (op1
) == INTEGER_CST
)
10753 if (code
== EQ_EXPR
)
10754 result
= tree_int_cst_equal (op0
, op1
);
10755 else if (TYPE_UNSIGNED (TREE_TYPE (op0
)))
10756 result
= INT_CST_LT_UNSIGNED (op0
, op1
);
10758 result
= INT_CST_LT (op0
, op1
);
10765 return constant_boolean_node (result
, type
);
10768 /* Build an expression for the a clean point containing EXPR with type TYPE.
10769 Don't build a cleanup point expression for EXPR which don't have side
10773 fold_build_cleanup_point_expr (tree type
, tree expr
)
10775 /* If the expression does not have side effects then we don't have to wrap
10776 it with a cleanup point expression. */
10777 if (!TREE_SIDE_EFFECTS (expr
))
10780 return build1 (CLEANUP_POINT_EXPR
, type
, expr
);
10783 /* Build an expression for the address of T. Folds away INDIRECT_REF to
10784 avoid confusing the gimplify process. */
10787 build_fold_addr_expr_with_type (tree t
, tree ptrtype
)
10789 /* The size of the object is not relevant when talking about its address. */
10790 if (TREE_CODE (t
) == WITH_SIZE_EXPR
)
10791 t
= TREE_OPERAND (t
, 0);
10793 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
10794 if (TREE_CODE (t
) == INDIRECT_REF
10795 || TREE_CODE (t
) == MISALIGNED_INDIRECT_REF
)
10797 t
= TREE_OPERAND (t
, 0);
10798 if (TREE_TYPE (t
) != ptrtype
)
10799 t
= build1 (NOP_EXPR
, ptrtype
, t
);
10805 while (handled_component_p (base
)
10806 || TREE_CODE (base
) == REALPART_EXPR
10807 || TREE_CODE (base
) == IMAGPART_EXPR
)
10808 base
= TREE_OPERAND (base
, 0);
10810 TREE_ADDRESSABLE (base
) = 1;
10812 t
= build1 (ADDR_EXPR
, ptrtype
, t
);
10819 build_fold_addr_expr (tree t
)
10821 return build_fold_addr_expr_with_type (t
, build_pointer_type (TREE_TYPE (t
)));
10824 /* Builds an expression for an indirection through T, simplifying some
10828 build_fold_indirect_ref (tree t
)
10830 tree type
= TREE_TYPE (TREE_TYPE (t
));
10835 if (TREE_CODE (sub
) == ADDR_EXPR
)
10837 tree op
= TREE_OPERAND (sub
, 0);
10838 tree optype
= TREE_TYPE (op
);
10840 if (lang_hooks
.types_compatible_p (type
, optype
))
10842 /* *(foo *)&fooarray => fooarray[0] */
10843 else if (TREE_CODE (optype
) == ARRAY_TYPE
10844 && lang_hooks
.types_compatible_p (type
, TREE_TYPE (optype
)))
10845 return build4 (ARRAY_REF
, type
, op
, size_zero_node
, NULL_TREE
, NULL_TREE
);
10848 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
10849 subtype
= TREE_TYPE (sub
);
10850 if (TREE_CODE (TREE_TYPE (subtype
)) == ARRAY_TYPE
10851 && lang_hooks
.types_compatible_p (type
, TREE_TYPE (TREE_TYPE (subtype
))))
10853 sub
= build_fold_indirect_ref (sub
);
10854 return build4 (ARRAY_REF
, type
, sub
, size_zero_node
, NULL_TREE
, NULL_TREE
);
10857 return build1 (INDIRECT_REF
, type
, t
);
10860 /* Strip non-trapping, non-side-effecting tree nodes from an expression
10861 whose result is ignored. The type of the returned tree need not be
10862 the same as the original expression. */
10865 fold_ignored_result (tree t
)
10867 if (!TREE_SIDE_EFFECTS (t
))
10868 return integer_zero_node
;
10871 switch (TREE_CODE_CLASS (TREE_CODE (t
)))
10874 t
= TREE_OPERAND (t
, 0);
10878 case tcc_comparison
:
10879 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 1)))
10880 t
= TREE_OPERAND (t
, 0);
10881 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 0)))
10882 t
= TREE_OPERAND (t
, 1);
10887 case tcc_expression
:
10888 switch (TREE_CODE (t
))
10890 case COMPOUND_EXPR
:
10891 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 1)))
10893 t
= TREE_OPERAND (t
, 0);
10897 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 1))
10898 || TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 2)))
10900 t
= TREE_OPERAND (t
, 0);
10913 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
10914 This can only be applied to objects of a sizetype. */
10917 round_up (tree value
, int divisor
)
10919 tree div
= NULL_TREE
;
10921 gcc_assert (divisor
> 0);
10925 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
10926 have to do anything. Only do this when we are not given a const,
10927 because in that case, this check is more expensive than just
10929 if (TREE_CODE (value
) != INTEGER_CST
)
10931 div
= build_int_cst (TREE_TYPE (value
), divisor
);
10933 if (multiple_of_p (TREE_TYPE (value
), value
, div
))
10937 /* If divisor is a power of two, simplify this to bit manipulation. */
10938 if (divisor
== (divisor
& -divisor
))
10942 t
= build_int_cst (TREE_TYPE (value
), divisor
- 1);
10943 value
= size_binop (PLUS_EXPR
, value
, t
);
10944 t
= build_int_cst (TREE_TYPE (value
), -divisor
);
10945 value
= size_binop (BIT_AND_EXPR
, value
, t
);
10950 div
= build_int_cst (TREE_TYPE (value
), divisor
);
10951 value
= size_binop (CEIL_DIV_EXPR
, value
, div
);
10952 value
= size_binop (MULT_EXPR
, value
, div
);
10958 /* Likewise, but round down. */
10961 round_down (tree value
, int divisor
)
10963 tree div
= NULL_TREE
;
10965 gcc_assert (divisor
> 0);
10969 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
10970 have to do anything. Only do this when we are not given a const,
10971 because in that case, this check is more expensive than just
10973 if (TREE_CODE (value
) != INTEGER_CST
)
10975 div
= build_int_cst (TREE_TYPE (value
), divisor
);
10977 if (multiple_of_p (TREE_TYPE (value
), value
, div
))
10981 /* If divisor is a power of two, simplify this to bit manipulation. */
10982 if (divisor
== (divisor
& -divisor
))
10986 t
= build_int_cst (TREE_TYPE (value
), -divisor
);
10987 value
= size_binop (BIT_AND_EXPR
, value
, t
);
10992 div
= build_int_cst (TREE_TYPE (value
), divisor
);
10993 value
= size_binop (FLOOR_DIV_EXPR
, value
, div
);
10994 value
= size_binop (MULT_EXPR
, value
, div
);
11000 /* Returns the pointer to the base of the object addressed by EXP and
11001 extracts the information about the offset of the access, storing it
11002 to PBITPOS and POFFSET. */
11005 split_address_to_core_and_offset (tree exp
,
11006 HOST_WIDE_INT
*pbitpos
, tree
*poffset
)
11009 enum machine_mode mode
;
11010 int unsignedp
, volatilep
;
11011 HOST_WIDE_INT bitsize
;
11013 if (TREE_CODE (exp
) == ADDR_EXPR
)
11015 core
= get_inner_reference (TREE_OPERAND (exp
, 0), &bitsize
, pbitpos
,
11016 poffset
, &mode
, &unsignedp
, &volatilep
);
11018 if (TREE_CODE (core
) == INDIRECT_REF
)
11019 core
= TREE_OPERAND (core
, 0);
11025 *poffset
= NULL_TREE
;
11031 /* Returns true if addresses of E1 and E2 differ by a constant, false
11032 otherwise. If they do, E1 - E2 is stored in *DIFF. */
11035 ptr_difference_const (tree e1
, tree e2
, HOST_WIDE_INT
*diff
)
11038 HOST_WIDE_INT bitpos1
, bitpos2
;
11039 tree toffset1
, toffset2
, tdiff
, type
;
11041 core1
= split_address_to_core_and_offset (e1
, &bitpos1
, &toffset1
);
11042 core2
= split_address_to_core_and_offset (e2
, &bitpos2
, &toffset2
);
11044 if (bitpos1
% BITS_PER_UNIT
!= 0
11045 || bitpos2
% BITS_PER_UNIT
!= 0
11046 || !operand_equal_p (core1
, core2
, 0))
11049 if (toffset1
&& toffset2
)
11051 type
= TREE_TYPE (toffset1
);
11052 if (type
!= TREE_TYPE (toffset2
))
11053 toffset2
= fold_convert (type
, toffset2
);
11055 tdiff
= fold (build2 (MINUS_EXPR
, type
, toffset1
, toffset2
));
11056 if (!host_integerp (tdiff
, 0))
11059 *diff
= tree_low_cst (tdiff
, 0);
11061 else if (toffset1
|| toffset2
)
11063 /* If only one of the offsets is non-constant, the difference cannot
11070 *diff
+= (bitpos1
- bitpos2
) / BITS_PER_UNIT
;