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 and prior overflow indicator, and
43 forces the value to fit the type. It returns an overflow indicator. */
47 #include "coretypes.h"
58 #include "langhooks.h"
61 static void encode (HOST_WIDE_INT
*, unsigned HOST_WIDE_INT
, HOST_WIDE_INT
);
62 static void decode (HOST_WIDE_INT
*, unsigned HOST_WIDE_INT
*, HOST_WIDE_INT
*);
63 static bool negate_mathfn_p (enum built_in_function
);
64 static bool negate_expr_p (tree
);
65 static tree
negate_expr (tree
);
66 static tree
split_tree (tree
, enum tree_code
, tree
*, tree
*, tree
*, int);
67 static tree
associate_trees (tree
, tree
, enum tree_code
, tree
);
68 static tree
int_const_binop (enum tree_code
, tree
, tree
, int);
69 static tree
const_binop (enum tree_code
, tree
, tree
, int);
70 static hashval_t
size_htab_hash (const void *);
71 static int size_htab_eq (const void *, const void *);
72 static tree
fold_convert_const (enum tree_code
, tree
, tree
);
73 static tree
fold_convert (tree
, tree
);
74 static enum tree_code
invert_tree_comparison (enum tree_code
);
75 static enum tree_code
swap_tree_comparison (enum tree_code
);
76 static int comparison_to_compcode (enum tree_code
);
77 static enum tree_code
compcode_to_comparison (int);
78 static int truth_value_p (enum tree_code
);
79 static int operand_equal_for_comparison_p (tree
, tree
, tree
);
80 static int twoval_comparison_p (tree
, tree
*, tree
*, int *);
81 static tree
eval_subst (tree
, tree
, tree
, tree
, tree
);
82 static tree
pedantic_omit_one_operand (tree
, tree
, tree
);
83 static tree
distribute_bit_expr (enum tree_code
, tree
, tree
, tree
);
84 static tree
make_bit_field_ref (tree
, tree
, int, int, int);
85 static tree
optimize_bit_field_compare (enum tree_code
, tree
, tree
, tree
);
86 static tree
decode_field_reference (tree
, HOST_WIDE_INT
*, HOST_WIDE_INT
*,
87 enum machine_mode
*, int *, int *,
89 static int all_ones_mask_p (tree
, int);
90 static tree
sign_bit_p (tree
, tree
);
91 static int simple_operand_p (tree
);
92 static tree
range_binop (enum tree_code
, tree
, tree
, int, tree
, int);
93 static tree
make_range (tree
, int *, tree
*, tree
*);
94 static tree
build_range_check (tree
, tree
, int, tree
, tree
);
95 static int merge_ranges (int *, tree
*, tree
*, int, tree
, tree
, int, tree
,
97 static tree
fold_range_test (tree
);
98 static tree
unextend (tree
, int, int, tree
);
99 static tree
fold_truthop (enum tree_code
, tree
, tree
, tree
);
100 static tree
optimize_minmax_comparison (tree
);
101 static tree
extract_muldiv (tree
, tree
, enum tree_code
, tree
);
102 static tree
extract_muldiv_1 (tree
, tree
, enum tree_code
, tree
);
103 static tree
strip_compound_expr (tree
, tree
);
104 static int multiple_of_p (tree
, tree
, tree
);
105 static tree
constant_boolean_node (int, tree
);
106 static int count_cond (tree
, int);
107 static tree
fold_binary_op_with_conditional_arg (enum tree_code
, tree
, tree
,
109 static bool fold_real_zero_addition_p (tree
, tree
, int);
110 static tree
fold_mathfn_compare (enum built_in_function
, enum tree_code
,
112 static tree
fold_inf_compare (enum tree_code
, tree
, tree
, tree
);
113 static bool reorder_operands_p (tree
, tree
);
114 static bool tree_swap_operands_p (tree
, tree
, bool);
116 /* The following constants represent a bit based encoding of GCC's
117 comparison operators. This encoding simplifies transformations
118 on relational comparison operators, such as AND and OR. */
119 #define COMPCODE_FALSE 0
120 #define COMPCODE_LT 1
121 #define COMPCODE_EQ 2
122 #define COMPCODE_LE 3
123 #define COMPCODE_GT 4
124 #define COMPCODE_NE 5
125 #define COMPCODE_GE 6
126 #define COMPCODE_TRUE 7
128 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
129 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
130 and SUM1. Then this yields nonzero if overflow occurred during the
133 Overflow occurs if A and B have the same sign, but A and SUM differ in
134 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
136 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
138 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
139 We do that by representing the two-word integer in 4 words, with only
140 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
141 number. The value of the word is LOWPART + HIGHPART * BASE. */
144 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
145 #define HIGHPART(x) \
146 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
147 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
149 /* Unpack a two-word integer into 4 words.
150 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
151 WORDS points to the array of HOST_WIDE_INTs. */
154 encode (HOST_WIDE_INT
*words
, unsigned HOST_WIDE_INT low
, HOST_WIDE_INT hi
)
156 words
[0] = LOWPART (low
);
157 words
[1] = HIGHPART (low
);
158 words
[2] = LOWPART (hi
);
159 words
[3] = HIGHPART (hi
);
162 /* Pack an array of 4 words into a two-word integer.
163 WORDS points to the array of words.
164 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
167 decode (HOST_WIDE_INT
*words
, unsigned HOST_WIDE_INT
*low
,
170 *low
= words
[0] + words
[1] * BASE
;
171 *hi
= words
[2] + words
[3] * BASE
;
174 /* Make the integer constant T valid for its type by setting to 0 or 1 all
175 the bits in the constant that don't belong in the type.
177 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
178 nonzero, a signed overflow has already occurred in calculating T, so
182 force_fit_type (tree t
, int overflow
)
184 unsigned HOST_WIDE_INT low
;
188 if (TREE_CODE (t
) == REAL_CST
)
190 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
191 Consider doing it via real_convert now. */
195 else if (TREE_CODE (t
) != INTEGER_CST
)
198 low
= TREE_INT_CST_LOW (t
);
199 high
= TREE_INT_CST_HIGH (t
);
201 if (POINTER_TYPE_P (TREE_TYPE (t
))
202 || TREE_CODE (TREE_TYPE (t
)) == OFFSET_TYPE
)
205 prec
= TYPE_PRECISION (TREE_TYPE (t
));
207 /* First clear all bits that are beyond the type's precision. */
209 if (prec
== 2 * HOST_BITS_PER_WIDE_INT
)
211 else if (prec
> HOST_BITS_PER_WIDE_INT
)
212 TREE_INT_CST_HIGH (t
)
213 &= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
216 TREE_INT_CST_HIGH (t
) = 0;
217 if (prec
< HOST_BITS_PER_WIDE_INT
)
218 TREE_INT_CST_LOW (t
) &= ~((unsigned HOST_WIDE_INT
) (-1) << prec
);
221 /* Unsigned types do not suffer sign extension or overflow unless they
223 if (TREE_UNSIGNED (TREE_TYPE (t
))
224 && ! (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
225 && TYPE_IS_SIZETYPE (TREE_TYPE (t
))))
228 /* If the value's sign bit is set, extend the sign. */
229 if (prec
!= 2 * HOST_BITS_PER_WIDE_INT
230 && (prec
> HOST_BITS_PER_WIDE_INT
231 ? 0 != (TREE_INT_CST_HIGH (t
)
233 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)))
234 : 0 != (TREE_INT_CST_LOW (t
)
235 & ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1)))))
237 /* Value is negative:
238 set to 1 all the bits that are outside this type's precision. */
239 if (prec
> HOST_BITS_PER_WIDE_INT
)
240 TREE_INT_CST_HIGH (t
)
241 |= ((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
244 TREE_INT_CST_HIGH (t
) = -1;
245 if (prec
< HOST_BITS_PER_WIDE_INT
)
246 TREE_INT_CST_LOW (t
) |= ((unsigned HOST_WIDE_INT
) (-1) << prec
);
250 /* Return nonzero if signed overflow occurred. */
252 ((overflow
| (low
^ TREE_INT_CST_LOW (t
)) | (high
^ TREE_INT_CST_HIGH (t
)))
256 /* Add two doubleword integers with doubleword result.
257 Each argument is given as two `HOST_WIDE_INT' pieces.
258 One argument is L1 and H1; the other, L2 and H2.
259 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
262 add_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
263 unsigned HOST_WIDE_INT l2
, HOST_WIDE_INT h2
,
264 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
266 unsigned HOST_WIDE_INT l
;
270 h
= h1
+ h2
+ (l
< l1
);
274 return OVERFLOW_SUM_SIGN (h1
, h2
, h
);
277 /* Negate a doubleword integer with doubleword result.
278 Return nonzero if the operation overflows, assuming it's signed.
279 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
280 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
283 neg_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
284 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
290 return (*hv
& h1
) < 0;
300 /* Multiply two doubleword integers with doubleword result.
301 Return nonzero if the operation overflows, assuming it's signed.
302 Each argument is given as two `HOST_WIDE_INT' pieces.
303 One argument is L1 and H1; the other, L2 and H2.
304 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
307 mul_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
308 unsigned HOST_WIDE_INT l2
, HOST_WIDE_INT h2
,
309 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
311 HOST_WIDE_INT arg1
[4];
312 HOST_WIDE_INT arg2
[4];
313 HOST_WIDE_INT prod
[4 * 2];
314 unsigned HOST_WIDE_INT carry
;
316 unsigned HOST_WIDE_INT toplow
, neglow
;
317 HOST_WIDE_INT tophigh
, neghigh
;
319 encode (arg1
, l1
, h1
);
320 encode (arg2
, l2
, h2
);
322 memset (prod
, 0, sizeof prod
);
324 for (i
= 0; i
< 4; i
++)
327 for (j
= 0; j
< 4; j
++)
330 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
331 carry
+= arg1
[i
] * arg2
[j
];
332 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
334 prod
[k
] = LOWPART (carry
);
335 carry
= HIGHPART (carry
);
340 decode (prod
, lv
, hv
); /* This ignores prod[4] through prod[4*2-1] */
342 /* Check for overflow by calculating the top half of the answer in full;
343 it should agree with the low half's sign bit. */
344 decode (prod
+ 4, &toplow
, &tophigh
);
347 neg_double (l2
, h2
, &neglow
, &neghigh
);
348 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
352 neg_double (l1
, h1
, &neglow
, &neghigh
);
353 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
355 return (*hv
< 0 ? ~(toplow
& tophigh
) : toplow
| tophigh
) != 0;
358 /* Shift the doubleword integer in L1, H1 left by COUNT places
359 keeping only PREC bits of result.
360 Shift right if COUNT is negative.
361 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
362 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
365 lshift_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
366 HOST_WIDE_INT count
, unsigned int prec
,
367 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
, int arith
)
369 unsigned HOST_WIDE_INT signmask
;
373 rshift_double (l1
, h1
, -count
, prec
, lv
, hv
, arith
);
377 if (SHIFT_COUNT_TRUNCATED
)
380 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
382 /* Shifting by the host word size is undefined according to the
383 ANSI standard, so we must handle this as a special case. */
387 else if (count
>= HOST_BITS_PER_WIDE_INT
)
389 *hv
= l1
<< (count
- HOST_BITS_PER_WIDE_INT
);
394 *hv
= (((unsigned HOST_WIDE_INT
) h1
<< count
)
395 | (l1
>> (HOST_BITS_PER_WIDE_INT
- count
- 1) >> 1));
399 /* Sign extend all bits that are beyond the precision. */
401 signmask
= -((prec
> HOST_BITS_PER_WIDE_INT
402 ? ((unsigned HOST_WIDE_INT
) *hv
403 >> (prec
- HOST_BITS_PER_WIDE_INT
- 1))
404 : (*lv
>> (prec
- 1))) & 1);
406 if (prec
>= 2 * HOST_BITS_PER_WIDE_INT
)
408 else if (prec
>= HOST_BITS_PER_WIDE_INT
)
410 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
411 *hv
|= signmask
<< (prec
- HOST_BITS_PER_WIDE_INT
);
416 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << prec
);
417 *lv
|= signmask
<< prec
;
421 /* Shift the doubleword integer in L1, H1 right by COUNT places
422 keeping only PREC bits of result. COUNT must be positive.
423 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
424 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
427 rshift_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
428 HOST_WIDE_INT count
, unsigned int prec
,
429 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
,
432 unsigned HOST_WIDE_INT signmask
;
435 ? -((unsigned HOST_WIDE_INT
) h1
>> (HOST_BITS_PER_WIDE_INT
- 1))
438 if (SHIFT_COUNT_TRUNCATED
)
441 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
443 /* Shifting by the host word size is undefined according to the
444 ANSI standard, so we must handle this as a special case. */
448 else if (count
>= HOST_BITS_PER_WIDE_INT
)
451 *lv
= (unsigned HOST_WIDE_INT
) h1
>> (count
- HOST_BITS_PER_WIDE_INT
);
455 *hv
= (unsigned HOST_WIDE_INT
) h1
>> count
;
457 | ((unsigned HOST_WIDE_INT
) h1
<< (HOST_BITS_PER_WIDE_INT
- count
- 1) << 1));
460 /* Zero / sign extend all bits that are beyond the precision. */
462 if (count
>= (HOST_WIDE_INT
)prec
)
467 else if ((prec
- count
) >= 2 * HOST_BITS_PER_WIDE_INT
)
469 else if ((prec
- count
) >= HOST_BITS_PER_WIDE_INT
)
471 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- count
- HOST_BITS_PER_WIDE_INT
));
472 *hv
|= signmask
<< (prec
- count
- HOST_BITS_PER_WIDE_INT
);
477 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << (prec
- count
));
478 *lv
|= signmask
<< (prec
- count
);
482 /* Rotate the doubleword integer in L1, H1 left by COUNT places
483 keeping only PREC bits of result.
484 Rotate right if COUNT is negative.
485 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
488 lrotate_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
489 HOST_WIDE_INT count
, unsigned int prec
,
490 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
492 unsigned HOST_WIDE_INT s1l
, s2l
;
493 HOST_WIDE_INT s1h
, s2h
;
499 lshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
500 rshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
505 /* Rotate the doubleword integer in L1, H1 left by COUNT places
506 keeping only PREC bits of result. COUNT must be positive.
507 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
510 rrotate_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
511 HOST_WIDE_INT count
, unsigned int prec
,
512 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
514 unsigned HOST_WIDE_INT s1l
, s2l
;
515 HOST_WIDE_INT s1h
, s2h
;
521 rshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
522 lshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
527 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
528 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
529 CODE is a tree code for a kind of division, one of
530 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
532 It controls how the quotient is rounded to an integer.
533 Return nonzero if the operation overflows.
534 UNS nonzero says do unsigned division. */
537 div_and_round_double (enum tree_code code
, int uns
,
538 unsigned HOST_WIDE_INT lnum_orig
, /* num == numerator == dividend */
539 HOST_WIDE_INT hnum_orig
,
540 unsigned HOST_WIDE_INT lden_orig
, /* den == denominator == divisor */
541 HOST_WIDE_INT hden_orig
,
542 unsigned HOST_WIDE_INT
*lquo
,
543 HOST_WIDE_INT
*hquo
, unsigned HOST_WIDE_INT
*lrem
,
547 HOST_WIDE_INT num
[4 + 1]; /* extra element for scaling. */
548 HOST_WIDE_INT den
[4], quo
[4];
550 unsigned HOST_WIDE_INT work
;
551 unsigned HOST_WIDE_INT carry
= 0;
552 unsigned HOST_WIDE_INT lnum
= lnum_orig
;
553 HOST_WIDE_INT hnum
= hnum_orig
;
554 unsigned HOST_WIDE_INT lden
= lden_orig
;
555 HOST_WIDE_INT hden
= hden_orig
;
558 if (hden
== 0 && lden
== 0)
559 overflow
= 1, lden
= 1;
561 /* Calculate quotient sign and convert operands to unsigned. */
567 /* (minimum integer) / (-1) is the only overflow case. */
568 if (neg_double (lnum
, hnum
, &lnum
, &hnum
)
569 && ((HOST_WIDE_INT
) lden
& hden
) == -1)
575 neg_double (lden
, hden
, &lden
, &hden
);
579 if (hnum
== 0 && hden
== 0)
580 { /* single precision */
582 /* This unsigned division rounds toward zero. */
588 { /* trivial case: dividend < divisor */
589 /* hden != 0 already checked. */
596 memset (quo
, 0, sizeof quo
);
598 memset (num
, 0, sizeof num
); /* to zero 9th element */
599 memset (den
, 0, sizeof den
);
601 encode (num
, lnum
, hnum
);
602 encode (den
, lden
, hden
);
604 /* Special code for when the divisor < BASE. */
605 if (hden
== 0 && lden
< (unsigned HOST_WIDE_INT
) BASE
)
607 /* hnum != 0 already checked. */
608 for (i
= 4 - 1; i
>= 0; i
--)
610 work
= num
[i
] + carry
* BASE
;
611 quo
[i
] = work
/ lden
;
617 /* Full double precision division,
618 with thanks to Don Knuth's "Seminumerical Algorithms". */
619 int num_hi_sig
, den_hi_sig
;
620 unsigned HOST_WIDE_INT quo_est
, scale
;
622 /* Find the highest nonzero divisor digit. */
623 for (i
= 4 - 1;; i
--)
630 /* Insure that the first digit of the divisor is at least BASE/2.
631 This is required by the quotient digit estimation algorithm. */
633 scale
= BASE
/ (den
[den_hi_sig
] + 1);
635 { /* scale divisor and dividend */
637 for (i
= 0; i
<= 4 - 1; i
++)
639 work
= (num
[i
] * scale
) + carry
;
640 num
[i
] = LOWPART (work
);
641 carry
= HIGHPART (work
);
646 for (i
= 0; i
<= 4 - 1; i
++)
648 work
= (den
[i
] * scale
) + carry
;
649 den
[i
] = LOWPART (work
);
650 carry
= HIGHPART (work
);
651 if (den
[i
] != 0) den_hi_sig
= i
;
658 for (i
= num_hi_sig
- den_hi_sig
- 1; i
>= 0; i
--)
660 /* Guess the next quotient digit, quo_est, by dividing the first
661 two remaining dividend digits by the high order quotient digit.
662 quo_est is never low and is at most 2 high. */
663 unsigned HOST_WIDE_INT tmp
;
665 num_hi_sig
= i
+ den_hi_sig
+ 1;
666 work
= num
[num_hi_sig
] * BASE
+ num
[num_hi_sig
- 1];
667 if (num
[num_hi_sig
] != den
[den_hi_sig
])
668 quo_est
= work
/ den
[den_hi_sig
];
672 /* Refine quo_est so it's usually correct, and at most one high. */
673 tmp
= work
- quo_est
* den
[den_hi_sig
];
675 && (den
[den_hi_sig
- 1] * quo_est
676 > (tmp
* BASE
+ num
[num_hi_sig
- 2])))
679 /* Try QUO_EST as the quotient digit, by multiplying the
680 divisor by QUO_EST and subtracting from the remaining dividend.
681 Keep in mind that QUO_EST is the I - 1st digit. */
684 for (j
= 0; j
<= den_hi_sig
; j
++)
686 work
= quo_est
* den
[j
] + carry
;
687 carry
= HIGHPART (work
);
688 work
= num
[i
+ j
] - LOWPART (work
);
689 num
[i
+ j
] = LOWPART (work
);
690 carry
+= HIGHPART (work
) != 0;
693 /* If quo_est was high by one, then num[i] went negative and
694 we need to correct things. */
695 if (num
[num_hi_sig
] < (HOST_WIDE_INT
) carry
)
698 carry
= 0; /* add divisor back in */
699 for (j
= 0; j
<= den_hi_sig
; j
++)
701 work
= num
[i
+ j
] + den
[j
] + carry
;
702 carry
= HIGHPART (work
);
703 num
[i
+ j
] = LOWPART (work
);
706 num
[num_hi_sig
] += carry
;
709 /* Store the quotient digit. */
714 decode (quo
, lquo
, hquo
);
717 /* If result is negative, make it so. */
719 neg_double (*lquo
, *hquo
, lquo
, hquo
);
721 /* Compute trial remainder: rem = num - (quo * den) */
722 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
723 neg_double (*lrem
, *hrem
, lrem
, hrem
);
724 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
729 case TRUNC_MOD_EXPR
: /* round toward zero */
730 case EXACT_DIV_EXPR
: /* for this one, it shouldn't matter */
734 case FLOOR_MOD_EXPR
: /* round toward negative infinity */
735 if (quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio < 0 && rem != 0 */
738 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1,
746 case CEIL_MOD_EXPR
: /* round toward positive infinity */
747 if (!quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio > 0 && rem != 0 */
749 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
757 case ROUND_MOD_EXPR
: /* round to closest integer */
759 unsigned HOST_WIDE_INT labs_rem
= *lrem
;
760 HOST_WIDE_INT habs_rem
= *hrem
;
761 unsigned HOST_WIDE_INT labs_den
= lden
, ltwice
;
762 HOST_WIDE_INT habs_den
= hden
, htwice
;
764 /* Get absolute values. */
766 neg_double (*lrem
, *hrem
, &labs_rem
, &habs_rem
);
768 neg_double (lden
, hden
, &labs_den
, &habs_den
);
770 /* If (2 * abs (lrem) >= abs (lden)) */
771 mul_double ((HOST_WIDE_INT
) 2, (HOST_WIDE_INT
) 0,
772 labs_rem
, habs_rem
, <wice
, &htwice
);
774 if (((unsigned HOST_WIDE_INT
) habs_den
775 < (unsigned HOST_WIDE_INT
) htwice
)
776 || (((unsigned HOST_WIDE_INT
) habs_den
777 == (unsigned HOST_WIDE_INT
) htwice
)
778 && (labs_den
< ltwice
)))
782 add_double (*lquo
, *hquo
,
783 (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1, lquo
, hquo
);
786 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
798 /* Compute true remainder: rem = num - (quo * den) */
799 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
800 neg_double (*lrem
, *hrem
, lrem
, hrem
);
801 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
805 /* Return true if built-in mathematical function specified by CODE
806 preserves the sign of it argument, i.e. -f(x) == f(-x). */
809 negate_mathfn_p (enum built_in_function code
)
833 /* Determine whether an expression T can be cheaply negated using
834 the function negate_expr. */
837 negate_expr_p (tree t
)
839 unsigned HOST_WIDE_INT val
;
846 type
= TREE_TYPE (t
);
849 switch (TREE_CODE (t
))
852 if (TREE_UNSIGNED (type
) || ! flag_trapv
)
855 /* Check that -CST will not overflow type. */
856 prec
= TYPE_PRECISION (type
);
857 if (prec
> HOST_BITS_PER_WIDE_INT
)
859 if (TREE_INT_CST_LOW (t
) != 0)
861 prec
-= HOST_BITS_PER_WIDE_INT
;
862 val
= TREE_INT_CST_HIGH (t
);
865 val
= TREE_INT_CST_LOW (t
);
866 if (prec
< HOST_BITS_PER_WIDE_INT
)
867 val
&= ((unsigned HOST_WIDE_INT
) 1 << prec
) - 1;
868 return val
!= ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1));
875 return negate_expr_p (TREE_REALPART (t
))
876 && negate_expr_p (TREE_IMAGPART (t
));
879 if (FLOAT_TYPE_P (type
) && !flag_unsafe_math_optimizations
)
881 /* -(A + B) -> (-B) - A. */
882 if (negate_expr_p (TREE_OPERAND (t
, 1))
883 && reorder_operands_p (TREE_OPERAND (t
, 0),
884 TREE_OPERAND (t
, 1)))
886 /* -(A + B) -> (-A) - B. */
887 return negate_expr_p (TREE_OPERAND (t
, 0));
890 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
891 return (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
892 && reorder_operands_p (TREE_OPERAND (t
, 0),
893 TREE_OPERAND (t
, 1));
896 if (TREE_UNSIGNED (TREE_TYPE (t
)))
902 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t
))))
903 return negate_expr_p (TREE_OPERAND (t
, 1))
904 || negate_expr_p (TREE_OPERAND (t
, 0));
908 /* Negate -((double)float) as (double)(-float). */
909 if (TREE_CODE (type
) == REAL_TYPE
)
911 tree tem
= strip_float_extensions (t
);
913 return negate_expr_p (tem
);
918 /* Negate -f(x) as f(-x). */
919 if (negate_mathfn_p (builtin_mathfn_code (t
)))
920 return negate_expr_p (TREE_VALUE (TREE_OPERAND (t
, 1)));
929 /* Given T, an expression, return the negation of T. Allow for T to be
930 null, in which case return null. */
941 type
= TREE_TYPE (t
);
944 switch (TREE_CODE (t
))
948 unsigned HOST_WIDE_INT low
;
950 int overflow
= neg_double (TREE_INT_CST_LOW (t
),
951 TREE_INT_CST_HIGH (t
),
953 tem
= build_int_2 (low
, high
);
954 TREE_TYPE (tem
) = type
;
957 | force_fit_type (tem
, overflow
&& !TREE_UNSIGNED (type
)));
958 TREE_CONSTANT_OVERFLOW (tem
)
959 = TREE_OVERFLOW (tem
) | TREE_CONSTANT_OVERFLOW (t
);
961 if (! TREE_OVERFLOW (tem
)
962 || TREE_UNSIGNED (type
)
968 tem
= build_real (type
, REAL_VALUE_NEGATE (TREE_REAL_CST (t
)));
969 /* Two's complement FP formats, such as c4x, may overflow. */
970 if (! TREE_OVERFLOW (tem
) || ! flag_trapping_math
)
971 return fold_convert (type
, tem
);
976 tree rpart
= negate_expr (TREE_REALPART (t
));
977 tree ipart
= negate_expr (TREE_IMAGPART (t
));
979 if ((TREE_CODE (rpart
) == REAL_CST
980 && TREE_CODE (ipart
) == REAL_CST
)
981 || (TREE_CODE (rpart
) == INTEGER_CST
982 && TREE_CODE (ipart
) == INTEGER_CST
))
983 return build_complex (type
, rpart
, ipart
);
988 return fold_convert (type
, TREE_OPERAND (t
, 0));
991 if (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
993 /* -(A + B) -> (-B) - A. */
994 if (negate_expr_p (TREE_OPERAND (t
, 1))
995 && reorder_operands_p (TREE_OPERAND (t
, 0),
996 TREE_OPERAND (t
, 1)))
997 return fold_convert (type
,
998 fold (build (MINUS_EXPR
, TREE_TYPE (t
),
999 negate_expr (TREE_OPERAND (t
, 1)),
1000 TREE_OPERAND (t
, 0))));
1001 /* -(A + B) -> (-A) - B. */
1002 if (negate_expr_p (TREE_OPERAND (t
, 0)))
1003 return fold_convert (type
,
1004 fold (build (MINUS_EXPR
, TREE_TYPE (t
),
1005 negate_expr (TREE_OPERAND (t
, 0)),
1006 TREE_OPERAND (t
, 1))));
1011 /* - (A - B) -> B - A */
1012 if ((! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
1013 && reorder_operands_p (TREE_OPERAND (t
, 0), TREE_OPERAND (t
, 1)))
1014 return fold_convert (type
,
1015 fold (build (MINUS_EXPR
, TREE_TYPE (t
),
1016 TREE_OPERAND (t
, 1),
1017 TREE_OPERAND (t
, 0))));
1021 if (TREE_UNSIGNED (TREE_TYPE (t
)))
1027 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t
))))
1029 tem
= TREE_OPERAND (t
, 1);
1030 if (negate_expr_p (tem
))
1031 return fold_convert (type
,
1032 fold (build (TREE_CODE (t
), TREE_TYPE (t
),
1033 TREE_OPERAND (t
, 0),
1034 negate_expr (tem
))));
1035 tem
= TREE_OPERAND (t
, 0);
1036 if (negate_expr_p (tem
))
1037 return fold_convert (type
,
1038 fold (build (TREE_CODE (t
), TREE_TYPE (t
),
1040 TREE_OPERAND (t
, 1))));
1045 /* Convert -((double)float) into (double)(-float). */
1046 if (TREE_CODE (type
) == REAL_TYPE
)
1048 tem
= strip_float_extensions (t
);
1049 if (tem
!= t
&& negate_expr_p (tem
))
1050 return fold_convert (type
, negate_expr (tem
));
1055 /* Negate -f(x) as f(-x). */
1056 if (negate_mathfn_p (builtin_mathfn_code (t
))
1057 && negate_expr_p (TREE_VALUE (TREE_OPERAND (t
, 1))))
1059 tree fndecl
, arg
, arglist
;
1061 fndecl
= get_callee_fndecl (t
);
1062 arg
= negate_expr (TREE_VALUE (TREE_OPERAND (t
, 1)));
1063 arglist
= build_tree_list (NULL_TREE
, arg
);
1064 return build_function_call_expr (fndecl
, arglist
);
1072 tem
= fold (build1 (NEGATE_EXPR
, TREE_TYPE (t
), t
));
1073 return fold_convert (type
, tem
);
1076 /* Split a tree IN into a constant, literal and variable parts that could be
1077 combined with CODE to make IN. "constant" means an expression with
1078 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1079 commutative arithmetic operation. Store the constant part into *CONP,
1080 the literal in *LITP and return the variable part. If a part isn't
1081 present, set it to null. If the tree does not decompose in this way,
1082 return the entire tree as the variable part and the other parts as null.
1084 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1085 case, we negate an operand that was subtracted. Except if it is a
1086 literal for which we use *MINUS_LITP instead.
1088 If NEGATE_P is true, we are negating all of IN, again except a literal
1089 for which we use *MINUS_LITP instead.
1091 If IN is itself a literal or constant, return it as appropriate.
1093 Note that we do not guarantee that any of the three values will be the
1094 same type as IN, but they will have the same signedness and mode. */
1097 split_tree (tree in
, enum tree_code code
, tree
*conp
, tree
*litp
,
1098 tree
*minus_litp
, int negate_p
)
1106 /* Strip any conversions that don't change the machine mode or signedness. */
1107 STRIP_SIGN_NOPS (in
);
1109 if (TREE_CODE (in
) == INTEGER_CST
|| TREE_CODE (in
) == REAL_CST
)
1111 else if (TREE_CODE (in
) == code
1112 || (! FLOAT_TYPE_P (TREE_TYPE (in
))
1113 /* We can associate addition and subtraction together (even
1114 though the C standard doesn't say so) for integers because
1115 the value is not affected. For reals, the value might be
1116 affected, so we can't. */
1117 && ((code
== PLUS_EXPR
&& TREE_CODE (in
) == MINUS_EXPR
)
1118 || (code
== MINUS_EXPR
&& TREE_CODE (in
) == PLUS_EXPR
))))
1120 tree op0
= TREE_OPERAND (in
, 0);
1121 tree op1
= TREE_OPERAND (in
, 1);
1122 int neg1_p
= TREE_CODE (in
) == MINUS_EXPR
;
1123 int neg_litp_p
= 0, neg_conp_p
= 0, neg_var_p
= 0;
1125 /* First see if either of the operands is a literal, then a constant. */
1126 if (TREE_CODE (op0
) == INTEGER_CST
|| TREE_CODE (op0
) == REAL_CST
)
1127 *litp
= op0
, op0
= 0;
1128 else if (TREE_CODE (op1
) == INTEGER_CST
|| TREE_CODE (op1
) == REAL_CST
)
1129 *litp
= op1
, neg_litp_p
= neg1_p
, op1
= 0;
1131 if (op0
!= 0 && TREE_CONSTANT (op0
))
1132 *conp
= op0
, op0
= 0;
1133 else if (op1
!= 0 && TREE_CONSTANT (op1
))
1134 *conp
= op1
, neg_conp_p
= neg1_p
, op1
= 0;
1136 /* If we haven't dealt with either operand, this is not a case we can
1137 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1138 if (op0
!= 0 && op1
!= 0)
1143 var
= op1
, neg_var_p
= neg1_p
;
1145 /* Now do any needed negations. */
1147 *minus_litp
= *litp
, *litp
= 0;
1149 *conp
= negate_expr (*conp
);
1151 var
= negate_expr (var
);
1153 else if (TREE_CONSTANT (in
))
1161 *minus_litp
= *litp
, *litp
= 0;
1162 else if (*minus_litp
)
1163 *litp
= *minus_litp
, *minus_litp
= 0;
1164 *conp
= negate_expr (*conp
);
1165 var
= negate_expr (var
);
1171 /* Re-associate trees split by the above function. T1 and T2 are either
1172 expressions to associate or null. Return the new expression, if any. If
1173 we build an operation, do it in TYPE and with CODE. */
1176 associate_trees (tree t1
, tree t2
, enum tree_code code
, tree type
)
1183 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1184 try to fold this since we will have infinite recursion. But do
1185 deal with any NEGATE_EXPRs. */
1186 if (TREE_CODE (t1
) == code
|| TREE_CODE (t2
) == code
1187 || TREE_CODE (t1
) == MINUS_EXPR
|| TREE_CODE (t2
) == MINUS_EXPR
)
1189 if (code
== PLUS_EXPR
)
1191 if (TREE_CODE (t1
) == NEGATE_EXPR
)
1192 return build (MINUS_EXPR
, type
, fold_convert (type
, t2
),
1193 fold_convert (type
, TREE_OPERAND (t1
, 0)));
1194 else if (TREE_CODE (t2
) == NEGATE_EXPR
)
1195 return build (MINUS_EXPR
, type
, fold_convert (type
, t1
),
1196 fold_convert (type
, TREE_OPERAND (t2
, 0)));
1198 return build (code
, type
, fold_convert (type
, t1
),
1199 fold_convert (type
, t2
));
1202 return fold (build (code
, type
, fold_convert (type
, t1
),
1203 fold_convert (type
, t2
)));
1206 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1207 to produce a new constant.
1209 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1212 int_const_binop (enum tree_code code
, tree arg1
, tree arg2
, int notrunc
)
1214 unsigned HOST_WIDE_INT int1l
, int2l
;
1215 HOST_WIDE_INT int1h
, int2h
;
1216 unsigned HOST_WIDE_INT low
;
1218 unsigned HOST_WIDE_INT garbagel
;
1219 HOST_WIDE_INT garbageh
;
1221 tree type
= TREE_TYPE (arg1
);
1222 int uns
= TREE_UNSIGNED (type
);
1224 = (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
));
1226 int no_overflow
= 0;
1228 int1l
= TREE_INT_CST_LOW (arg1
);
1229 int1h
= TREE_INT_CST_HIGH (arg1
);
1230 int2l
= TREE_INT_CST_LOW (arg2
);
1231 int2h
= TREE_INT_CST_HIGH (arg2
);
1236 low
= int1l
| int2l
, hi
= int1h
| int2h
;
1240 low
= int1l
^ int2l
, hi
= int1h
^ int2h
;
1244 low
= int1l
& int2l
, hi
= int1h
& int2h
;
1250 /* It's unclear from the C standard whether shifts can overflow.
1251 The following code ignores overflow; perhaps a C standard
1252 interpretation ruling is needed. */
1253 lshift_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1261 lrotate_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1266 overflow
= add_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1270 neg_double (int2l
, int2h
, &low
, &hi
);
1271 add_double (int1l
, int1h
, low
, hi
, &low
, &hi
);
1272 overflow
= OVERFLOW_SUM_SIGN (hi
, int2h
, int1h
);
1276 overflow
= mul_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1279 case TRUNC_DIV_EXPR
:
1280 case FLOOR_DIV_EXPR
: case CEIL_DIV_EXPR
:
1281 case EXACT_DIV_EXPR
:
1282 /* This is a shortcut for a common special case. */
1283 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1284 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1285 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1286 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1288 if (code
== CEIL_DIV_EXPR
)
1291 low
= int1l
/ int2l
, hi
= 0;
1295 /* ... fall through ... */
1297 case ROUND_DIV_EXPR
:
1298 if (int2h
== 0 && int2l
== 1)
1300 low
= int1l
, hi
= int1h
;
1303 if (int1l
== int2l
&& int1h
== int2h
1304 && ! (int1l
== 0 && int1h
== 0))
1309 overflow
= div_and_round_double (code
, uns
, int1l
, int1h
, int2l
, int2h
,
1310 &low
, &hi
, &garbagel
, &garbageh
);
1313 case TRUNC_MOD_EXPR
:
1314 case FLOOR_MOD_EXPR
: case CEIL_MOD_EXPR
:
1315 /* This is a shortcut for a common special case. */
1316 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1317 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1318 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1319 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1321 if (code
== CEIL_MOD_EXPR
)
1323 low
= int1l
% int2l
, hi
= 0;
1327 /* ... fall through ... */
1329 case ROUND_MOD_EXPR
:
1330 overflow
= div_and_round_double (code
, uns
,
1331 int1l
, int1h
, int2l
, int2h
,
1332 &garbagel
, &garbageh
, &low
, &hi
);
1338 low
= (((unsigned HOST_WIDE_INT
) int1h
1339 < (unsigned HOST_WIDE_INT
) int2h
)
1340 || (((unsigned HOST_WIDE_INT
) int1h
1341 == (unsigned HOST_WIDE_INT
) int2h
)
1344 low
= (int1h
< int2h
1345 || (int1h
== int2h
&& int1l
< int2l
));
1347 if (low
== (code
== MIN_EXPR
))
1348 low
= int1l
, hi
= int1h
;
1350 low
= int2l
, hi
= int2h
;
1357 /* If this is for a sizetype, can be represented as one (signed)
1358 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1361 && ((hi
== 0 && (HOST_WIDE_INT
) low
>= 0)
1362 || (hi
== -1 && (HOST_WIDE_INT
) low
< 0))
1363 && overflow
== 0 && ! TREE_OVERFLOW (arg1
) && ! TREE_OVERFLOW (arg2
))
1364 return size_int_type_wide (low
, type
);
1367 t
= build_int_2 (low
, hi
);
1368 TREE_TYPE (t
) = TREE_TYPE (arg1
);
1373 ? (!uns
|| is_sizetype
) && overflow
1374 : (force_fit_type (t
, (!uns
|| is_sizetype
) && overflow
)
1376 | TREE_OVERFLOW (arg1
)
1377 | TREE_OVERFLOW (arg2
));
1379 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1380 So check if force_fit_type truncated the value. */
1382 && ! TREE_OVERFLOW (t
)
1383 && (TREE_INT_CST_HIGH (t
) != hi
1384 || TREE_INT_CST_LOW (t
) != low
))
1385 TREE_OVERFLOW (t
) = 1;
1387 TREE_CONSTANT_OVERFLOW (t
) = (TREE_OVERFLOW (t
)
1388 | TREE_CONSTANT_OVERFLOW (arg1
)
1389 | TREE_CONSTANT_OVERFLOW (arg2
));
1393 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1394 constant. We assume ARG1 and ARG2 have the same data type, or at least
1395 are the same kind of constant and the same machine mode.
1397 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1400 const_binop (enum tree_code code
, tree arg1
, tree arg2
, int notrunc
)
1405 if (TREE_CODE (arg1
) == INTEGER_CST
)
1406 return int_const_binop (code
, arg1
, arg2
, notrunc
);
1408 if (TREE_CODE (arg1
) == REAL_CST
)
1410 enum machine_mode mode
;
1413 REAL_VALUE_TYPE value
;
1416 d1
= TREE_REAL_CST (arg1
);
1417 d2
= TREE_REAL_CST (arg2
);
1419 type
= TREE_TYPE (arg1
);
1420 mode
= TYPE_MODE (type
);
1422 /* Don't perform operation if we honor signaling NaNs and
1423 either operand is a NaN. */
1424 if (HONOR_SNANS (mode
)
1425 && (REAL_VALUE_ISNAN (d1
) || REAL_VALUE_ISNAN (d2
)))
1428 /* Don't perform operation if it would raise a division
1429 by zero exception. */
1430 if (code
== RDIV_EXPR
1431 && REAL_VALUES_EQUAL (d2
, dconst0
)
1432 && (flag_trapping_math
|| ! MODE_HAS_INFINITIES (mode
)))
1435 /* If either operand is a NaN, just return it. Otherwise, set up
1436 for floating-point trap; we return an overflow. */
1437 if (REAL_VALUE_ISNAN (d1
))
1439 else if (REAL_VALUE_ISNAN (d2
))
1442 REAL_ARITHMETIC (value
, code
, d1
, d2
);
1444 t
= build_real (type
, real_value_truncate (mode
, value
));
1447 = (force_fit_type (t
, 0)
1448 | TREE_OVERFLOW (arg1
) | TREE_OVERFLOW (arg2
));
1449 TREE_CONSTANT_OVERFLOW (t
)
1451 | TREE_CONSTANT_OVERFLOW (arg1
)
1452 | TREE_CONSTANT_OVERFLOW (arg2
);
1455 if (TREE_CODE (arg1
) == COMPLEX_CST
)
1457 tree type
= TREE_TYPE (arg1
);
1458 tree r1
= TREE_REALPART (arg1
);
1459 tree i1
= TREE_IMAGPART (arg1
);
1460 tree r2
= TREE_REALPART (arg2
);
1461 tree i2
= TREE_IMAGPART (arg2
);
1467 t
= build_complex (type
,
1468 const_binop (PLUS_EXPR
, r1
, r2
, notrunc
),
1469 const_binop (PLUS_EXPR
, i1
, i2
, notrunc
));
1473 t
= build_complex (type
,
1474 const_binop (MINUS_EXPR
, r1
, r2
, notrunc
),
1475 const_binop (MINUS_EXPR
, i1
, i2
, notrunc
));
1479 t
= build_complex (type
,
1480 const_binop (MINUS_EXPR
,
1481 const_binop (MULT_EXPR
,
1483 const_binop (MULT_EXPR
,
1486 const_binop (PLUS_EXPR
,
1487 const_binop (MULT_EXPR
,
1489 const_binop (MULT_EXPR
,
1497 = const_binop (PLUS_EXPR
,
1498 const_binop (MULT_EXPR
, r2
, r2
, notrunc
),
1499 const_binop (MULT_EXPR
, i2
, i2
, notrunc
),
1502 t
= build_complex (type
,
1504 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1505 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1506 const_binop (PLUS_EXPR
,
1507 const_binop (MULT_EXPR
, r1
, r2
,
1509 const_binop (MULT_EXPR
, i1
, i2
,
1512 magsquared
, notrunc
),
1514 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1515 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1516 const_binop (MINUS_EXPR
,
1517 const_binop (MULT_EXPR
, i1
, r2
,
1519 const_binop (MULT_EXPR
, r1
, i2
,
1522 magsquared
, notrunc
));
1534 /* These are the hash table functions for the hash table of INTEGER_CST
1535 nodes of a sizetype. */
1537 /* Return the hash code code X, an INTEGER_CST. */
1540 size_htab_hash (const void *x
)
1544 return (TREE_INT_CST_HIGH (t
) ^ TREE_INT_CST_LOW (t
)
1545 ^ htab_hash_pointer (TREE_TYPE (t
))
1546 ^ (TREE_OVERFLOW (t
) << 20));
1549 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1550 is the same as that given by *Y, which is the same. */
1553 size_htab_eq (const void *x
, const void *y
)
1558 return (TREE_INT_CST_HIGH (xt
) == TREE_INT_CST_HIGH (yt
)
1559 && TREE_INT_CST_LOW (xt
) == TREE_INT_CST_LOW (yt
)
1560 && TREE_TYPE (xt
) == TREE_TYPE (yt
)
1561 && TREE_OVERFLOW (xt
) == TREE_OVERFLOW (yt
));
1564 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1565 bits are given by NUMBER and of the sizetype represented by KIND. */
1568 size_int_wide (HOST_WIDE_INT number
, enum size_type_kind kind
)
1570 return size_int_type_wide (number
, sizetype_tab
[(int) kind
]);
1573 /* Likewise, but the desired type is specified explicitly. */
1575 static GTY (()) tree new_const
;
1576 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node
)))
1580 size_int_type_wide (HOST_WIDE_INT number
, tree type
)
1586 size_htab
= htab_create_ggc (1024, size_htab_hash
, size_htab_eq
, NULL
);
1587 new_const
= make_node (INTEGER_CST
);
1590 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1591 hash table, we return the value from the hash table. Otherwise, we
1592 place that in the hash table and make a new node for the next time. */
1593 TREE_INT_CST_LOW (new_const
) = number
;
1594 TREE_INT_CST_HIGH (new_const
) = number
< 0 ? -1 : 0;
1595 TREE_TYPE (new_const
) = type
;
1596 TREE_OVERFLOW (new_const
) = TREE_CONSTANT_OVERFLOW (new_const
)
1597 = force_fit_type (new_const
, 0);
1599 slot
= htab_find_slot (size_htab
, new_const
, INSERT
);
1605 new_const
= make_node (INTEGER_CST
);
1609 return (tree
) *slot
;
1612 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1613 is a tree code. The type of the result is taken from the operands.
1614 Both must be the same type integer type and it must be a size type.
1615 If the operands are constant, so is the result. */
1618 size_binop (enum tree_code code
, tree arg0
, tree arg1
)
1620 tree type
= TREE_TYPE (arg0
);
1622 if (TREE_CODE (type
) != INTEGER_TYPE
|| ! TYPE_IS_SIZETYPE (type
)
1623 || type
!= TREE_TYPE (arg1
))
1626 /* Handle the special case of two integer constants faster. */
1627 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
1629 /* And some specific cases even faster than that. */
1630 if (code
== PLUS_EXPR
&& integer_zerop (arg0
))
1632 else if ((code
== MINUS_EXPR
|| code
== PLUS_EXPR
)
1633 && integer_zerop (arg1
))
1635 else if (code
== MULT_EXPR
&& integer_onep (arg0
))
1638 /* Handle general case of two integer constants. */
1639 return int_const_binop (code
, arg0
, arg1
, 0);
1642 if (arg0
== error_mark_node
|| arg1
== error_mark_node
)
1643 return error_mark_node
;
1645 return fold (build (code
, type
, arg0
, arg1
));
1648 /* Given two values, either both of sizetype or both of bitsizetype,
1649 compute the difference between the two values. Return the value
1650 in signed type corresponding to the type of the operands. */
1653 size_diffop (tree arg0
, tree arg1
)
1655 tree type
= TREE_TYPE (arg0
);
1658 if (TREE_CODE (type
) != INTEGER_TYPE
|| ! TYPE_IS_SIZETYPE (type
)
1659 || type
!= TREE_TYPE (arg1
))
1662 /* If the type is already signed, just do the simple thing. */
1663 if (! TREE_UNSIGNED (type
))
1664 return size_binop (MINUS_EXPR
, arg0
, arg1
);
1666 ctype
= (type
== bitsizetype
|| type
== ubitsizetype
1667 ? sbitsizetype
: ssizetype
);
1669 /* If either operand is not a constant, do the conversions to the signed
1670 type and subtract. The hardware will do the right thing with any
1671 overflow in the subtraction. */
1672 if (TREE_CODE (arg0
) != INTEGER_CST
|| TREE_CODE (arg1
) != INTEGER_CST
)
1673 return size_binop (MINUS_EXPR
, fold_convert (ctype
, arg0
),
1674 fold_convert (ctype
, arg1
));
1676 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1677 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1678 overflow) and negate (which can't either). Special-case a result
1679 of zero while we're here. */
1680 if (tree_int_cst_equal (arg0
, arg1
))
1681 return fold_convert (ctype
, integer_zero_node
);
1682 else if (tree_int_cst_lt (arg1
, arg0
))
1683 return fold_convert (ctype
, size_binop (MINUS_EXPR
, arg0
, arg1
));
1685 return size_binop (MINUS_EXPR
, fold_convert (ctype
, integer_zero_node
),
1686 fold_convert (ctype
, size_binop (MINUS_EXPR
,
1691 /* Attempt to fold type conversion operation CODE of expression ARG1 to
1692 type TYPE. If no simplification can be done return NULL_TREE. */
1695 fold_convert_const (enum tree_code code
, tree type
, tree arg1
)
1700 if (TREE_TYPE (arg1
) == type
)
1703 if (POINTER_TYPE_P (type
) || INTEGRAL_TYPE_P (type
))
1705 if (TREE_CODE (arg1
) == INTEGER_CST
)
1707 /* If we would build a constant wider than GCC supports,
1708 leave the conversion unfolded. */
1709 if (TYPE_PRECISION (type
) > 2 * HOST_BITS_PER_WIDE_INT
)
1712 /* If we are trying to make a sizetype for a small integer, use
1713 size_int to pick up cached types to reduce duplicate nodes. */
1714 if (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
)
1715 && !TREE_CONSTANT_OVERFLOW (arg1
)
1716 && compare_tree_int (arg1
, 10000) < 0)
1717 return size_int_type_wide (TREE_INT_CST_LOW (arg1
), type
);
1719 /* Given an integer constant, make new constant with new type,
1720 appropriately sign-extended or truncated. */
1721 t
= build_int_2 (TREE_INT_CST_LOW (arg1
),
1722 TREE_INT_CST_HIGH (arg1
));
1723 TREE_TYPE (t
) = type
;
1724 /* Indicate an overflow if (1) ARG1 already overflowed,
1725 or (2) force_fit_type indicates an overflow.
1726 Tell force_fit_type that an overflow has already occurred
1727 if ARG1 is a too-large unsigned value and T is signed.
1728 But don't indicate an overflow if converting a pointer. */
1730 = ((force_fit_type (t
,
1731 (TREE_INT_CST_HIGH (arg1
) < 0
1732 && (TREE_UNSIGNED (type
)
1733 < TREE_UNSIGNED (TREE_TYPE (arg1
)))))
1734 && ! POINTER_TYPE_P (TREE_TYPE (arg1
)))
1735 || TREE_OVERFLOW (arg1
));
1736 TREE_CONSTANT_OVERFLOW (t
)
1737 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1740 else if (TREE_CODE (arg1
) == REAL_CST
)
1742 /* The following code implements the floating point to integer
1743 conversion rules required by the Java Language Specification,
1744 that IEEE NaNs are mapped to zero and values that overflow
1745 the target precision saturate, i.e. values greater than
1746 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1747 are mapped to INT_MIN. These semantics are allowed by the
1748 C and C++ standards that simply state that the behavior of
1749 FP-to-integer conversion is unspecified upon overflow. */
1751 HOST_WIDE_INT high
, low
;
1754 REAL_VALUE_TYPE x
= TREE_REAL_CST (arg1
);
1758 case FIX_TRUNC_EXPR
:
1759 real_trunc (&r
, VOIDmode
, &x
);
1763 real_ceil (&r
, VOIDmode
, &x
);
1766 case FIX_FLOOR_EXPR
:
1767 real_floor (&r
, VOIDmode
, &x
);
1774 /* If R is NaN, return zero and show we have an overflow. */
1775 if (REAL_VALUE_ISNAN (r
))
1782 /* See if R is less than the lower bound or greater than the
1787 tree lt
= TYPE_MIN_VALUE (type
);
1788 REAL_VALUE_TYPE l
= real_value_from_int_cst (NULL_TREE
, lt
);
1789 if (REAL_VALUES_LESS (r
, l
))
1792 high
= TREE_INT_CST_HIGH (lt
);
1793 low
= TREE_INT_CST_LOW (lt
);
1799 tree ut
= TYPE_MAX_VALUE (type
);
1802 REAL_VALUE_TYPE u
= real_value_from_int_cst (NULL_TREE
, ut
);
1803 if (REAL_VALUES_LESS (u
, r
))
1806 high
= TREE_INT_CST_HIGH (ut
);
1807 low
= TREE_INT_CST_LOW (ut
);
1813 REAL_VALUE_TO_INT (&low
, &high
, r
);
1815 t
= build_int_2 (low
, high
);
1816 TREE_TYPE (t
) = type
;
1818 = TREE_OVERFLOW (arg1
) | force_fit_type (t
, overflow
);
1819 TREE_CONSTANT_OVERFLOW (t
)
1820 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1824 else if (TREE_CODE (type
) == REAL_TYPE
)
1826 if (TREE_CODE (arg1
) == INTEGER_CST
)
1827 return build_real_from_int_cst (type
, arg1
);
1828 if (TREE_CODE (arg1
) == REAL_CST
)
1830 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
1832 /* We make a copy of ARG1 so that we don't modify an
1833 existing constant tree. */
1834 t
= copy_node (arg1
);
1835 TREE_TYPE (t
) = type
;
1839 t
= build_real (type
,
1840 real_value_truncate (TYPE_MODE (type
),
1841 TREE_REAL_CST (arg1
)));
1844 = TREE_OVERFLOW (arg1
) | force_fit_type (t
, 0);
1845 TREE_CONSTANT_OVERFLOW (t
)
1846 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1853 /* Convert expression ARG to type TYPE. Used by the middle-end for
1854 simple conversions in preference to calling the front-end's convert. */
1857 fold_convert (tree type
, tree arg
)
1859 tree orig
= TREE_TYPE (arg
);
1865 if (TREE_CODE (arg
) == ERROR_MARK
1866 || TREE_CODE (type
) == ERROR_MARK
1867 || TREE_CODE (orig
) == ERROR_MARK
)
1868 return error_mark_node
;
1870 if (TYPE_MAIN_VARIANT (type
) == TYPE_MAIN_VARIANT (orig
))
1871 return fold (build1 (NOP_EXPR
, type
, arg
));
1873 if (INTEGRAL_TYPE_P (type
) || POINTER_TYPE_P (type
))
1875 if (TREE_CODE (arg
) == INTEGER_CST
)
1877 tem
= fold_convert_const (NOP_EXPR
, type
, arg
);
1878 if (tem
!= NULL_TREE
)
1881 if (INTEGRAL_TYPE_P (orig
) || POINTER_TYPE_P (orig
))
1882 return fold (build1 (NOP_EXPR
, type
, arg
));
1883 if (TREE_CODE (orig
) == COMPLEX_TYPE
)
1885 tem
= fold (build1 (REALPART_EXPR
, TREE_TYPE (orig
), arg
));
1886 return fold_convert (type
, tem
);
1888 if (TREE_CODE (orig
) == VECTOR_TYPE
1889 && GET_MODE_SIZE (TYPE_MODE (type
))
1890 == GET_MODE_SIZE (TYPE_MODE (orig
)))
1891 return fold (build1 (NOP_EXPR
, type
, arg
));
1893 else if (TREE_CODE (type
) == REAL_TYPE
)
1895 if (TREE_CODE (arg
) == INTEGER_CST
)
1897 tem
= fold_convert_const (FLOAT_EXPR
, type
, arg
);
1898 if (tem
!= NULL_TREE
)
1901 else if (TREE_CODE (arg
) == REAL_CST
)
1903 tem
= fold_convert_const (NOP_EXPR
, type
, arg
);
1904 if (tem
!= NULL_TREE
)
1908 if (INTEGRAL_TYPE_P (orig
) || POINTER_TYPE_P (orig
))
1909 return fold (build1 (FLOAT_EXPR
, type
, arg
));
1910 if (TREE_CODE (orig
) == REAL_TYPE
)
1911 return fold (build1 (flag_float_store
? CONVERT_EXPR
: NOP_EXPR
,
1913 if (TREE_CODE (orig
) == COMPLEX_TYPE
)
1915 tem
= fold (build1 (REALPART_EXPR
, TREE_TYPE (orig
), arg
));
1916 return fold_convert (type
, tem
);
1919 else if (TREE_CODE (type
) == COMPLEX_TYPE
)
1921 if (INTEGRAL_TYPE_P (orig
)
1922 || POINTER_TYPE_P (orig
)
1923 || TREE_CODE (orig
) == REAL_TYPE
)
1924 return build (COMPLEX_EXPR
, type
,
1925 fold_convert (TREE_TYPE (type
), arg
),
1926 fold_convert (TREE_TYPE (type
), integer_zero_node
));
1927 if (TREE_CODE (orig
) == COMPLEX_TYPE
)
1931 if (TREE_CODE (arg
) == COMPLEX_EXPR
)
1933 rpart
= fold_convert (TREE_TYPE (type
), TREE_OPERAND (arg
, 0));
1934 ipart
= fold_convert (TREE_TYPE (type
), TREE_OPERAND (arg
, 1));
1935 return fold (build (COMPLEX_EXPR
, type
, rpart
, ipart
));
1938 arg
= save_expr (arg
);
1939 rpart
= fold (build1 (REALPART_EXPR
, TREE_TYPE (orig
), arg
));
1940 ipart
= fold (build1 (IMAGPART_EXPR
, TREE_TYPE (orig
), arg
));
1941 rpart
= fold_convert (TREE_TYPE (type
), rpart
);
1942 ipart
= fold_convert (TREE_TYPE (type
), ipart
);
1943 return fold (build (COMPLEX_EXPR
, type
, rpart
, ipart
));
1946 else if (TREE_CODE (type
) == VECTOR_TYPE
)
1948 if ((INTEGRAL_TYPE_P (orig
) || POINTER_TYPE_P (orig
))
1949 && GET_MODE_SIZE (TYPE_MODE (type
))
1950 == GET_MODE_SIZE (TYPE_MODE (orig
)))
1951 return fold (build1 (NOP_EXPR
, type
, arg
));
1952 if (TREE_CODE (orig
) == VECTOR_TYPE
1953 && GET_MODE_SIZE (TYPE_MODE (type
))
1954 == GET_MODE_SIZE (TYPE_MODE (orig
)))
1955 return fold (build1 (NOP_EXPR
, type
, arg
));
1957 else if (VOID_TYPE_P (type
))
1958 return fold (build1 (CONVERT_EXPR
, type
, arg
));
1962 /* Return an expr equal to X but certainly not valid as an lvalue. */
1969 /* These things are certainly not lvalues. */
1970 if (TREE_CODE (x
) == NON_LVALUE_EXPR
1971 || TREE_CODE (x
) == INTEGER_CST
1972 || TREE_CODE (x
) == REAL_CST
1973 || TREE_CODE (x
) == STRING_CST
1974 || TREE_CODE (x
) == ADDR_EXPR
)
1977 result
= build1 (NON_LVALUE_EXPR
, TREE_TYPE (x
), x
);
1978 TREE_CONSTANT (result
) = TREE_CONSTANT (x
);
1982 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1983 Zero means allow extended lvalues. */
1985 int pedantic_lvalues
;
1987 /* When pedantic, return an expr equal to X but certainly not valid as a
1988 pedantic lvalue. Otherwise, return X. */
1991 pedantic_non_lvalue (tree x
)
1993 if (pedantic_lvalues
)
1994 return non_lvalue (x
);
1999 /* Given a tree comparison code, return the code that is the logical inverse
2000 of the given code. It is not safe to do this for floating-point
2001 comparisons, except for NE_EXPR and EQ_EXPR. */
2003 static enum tree_code
2004 invert_tree_comparison (enum tree_code code
)
2025 /* Similar, but return the comparison that results if the operands are
2026 swapped. This is safe for floating-point. */
2028 static enum tree_code
2029 swap_tree_comparison (enum tree_code code
)
2050 /* Convert a comparison tree code from an enum tree_code representation
2051 into a compcode bit-based encoding. This function is the inverse of
2052 compcode_to_comparison. */
2055 comparison_to_compcode (enum tree_code code
)
2076 /* Convert a compcode bit-based encoding of a comparison operator back
2077 to GCC's enum tree_code representation. This function is the
2078 inverse of comparison_to_compcode. */
2080 static enum tree_code
2081 compcode_to_comparison (int code
)
2102 /* Return nonzero if CODE is a tree code that represents a truth value. */
2105 truth_value_p (enum tree_code code
)
2107 return (TREE_CODE_CLASS (code
) == '<'
2108 || code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
2109 || code
== TRUTH_OR_EXPR
|| code
== TRUTH_ORIF_EXPR
2110 || code
== TRUTH_XOR_EXPR
|| code
== TRUTH_NOT_EXPR
);
2113 /* Return nonzero if two operands (typically of the same tree node)
2114 are necessarily equal. If either argument has side-effects this
2115 function returns zero.
2117 If ONLY_CONST is nonzero, only return nonzero for constants.
2118 This function tests whether the operands are indistinguishable;
2119 it does not test whether they are equal using C's == operation.
2120 The distinction is important for IEEE floating point, because
2121 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2122 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2124 If ONLY_CONST is zero, a VAR_DECL is considered equal to itself
2125 even though it may hold multiple values during a function.
2126 This is because a GCC tree node guarantees that nothing else is
2127 executed between the evaluation of its "operands" (which may often
2128 be evaluated in arbitrary order). Hence if the operands themselves
2129 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2130 same value in each operand/subexpression. Hence a zero value for
2131 ONLY_CONST assumes isochronic (or instantaneous) tree equivalence.
2132 If comparing arbitrary expression trees, such as from different
2133 statements, ONLY_CONST must usually be nonzero. */
2136 operand_equal_p (tree arg0
, tree arg1
, int only_const
)
2140 /* If both types don't have the same signedness, then we can't consider
2141 them equal. We must check this before the STRIP_NOPS calls
2142 because they may change the signedness of the arguments. */
2143 if (TREE_UNSIGNED (TREE_TYPE (arg0
)) != TREE_UNSIGNED (TREE_TYPE (arg1
)))
2149 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
2150 /* This is needed for conversions and for COMPONENT_REF.
2151 Might as well play it safe and always test this. */
2152 || TREE_CODE (TREE_TYPE (arg0
)) == ERROR_MARK
2153 || TREE_CODE (TREE_TYPE (arg1
)) == ERROR_MARK
2154 || TYPE_MODE (TREE_TYPE (arg0
)) != TYPE_MODE (TREE_TYPE (arg1
)))
2157 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2158 We don't care about side effects in that case because the SAVE_EXPR
2159 takes care of that for us. In all other cases, two expressions are
2160 equal if they have no side effects. If we have two identical
2161 expressions with side effects that should be treated the same due
2162 to the only side effects being identical SAVE_EXPR's, that will
2163 be detected in the recursive calls below. */
2164 if (arg0
== arg1
&& ! only_const
2165 && (TREE_CODE (arg0
) == SAVE_EXPR
2166 || (! TREE_SIDE_EFFECTS (arg0
) && ! TREE_SIDE_EFFECTS (arg1
))))
2169 /* Next handle constant cases, those for which we can return 1 even
2170 if ONLY_CONST is set. */
2171 if (TREE_CONSTANT (arg0
) && TREE_CONSTANT (arg1
))
2172 switch (TREE_CODE (arg0
))
2175 return (! TREE_CONSTANT_OVERFLOW (arg0
)
2176 && ! TREE_CONSTANT_OVERFLOW (arg1
)
2177 && tree_int_cst_equal (arg0
, arg1
));
2180 return (! TREE_CONSTANT_OVERFLOW (arg0
)
2181 && ! TREE_CONSTANT_OVERFLOW (arg1
)
2182 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0
),
2183 TREE_REAL_CST (arg1
)));
2189 if (TREE_CONSTANT_OVERFLOW (arg0
)
2190 || TREE_CONSTANT_OVERFLOW (arg1
))
2193 v1
= TREE_VECTOR_CST_ELTS (arg0
);
2194 v2
= TREE_VECTOR_CST_ELTS (arg1
);
2197 if (!operand_equal_p (TREE_VALUE (v1
), TREE_VALUE (v2
),
2200 v1
= TREE_CHAIN (v1
);
2201 v2
= TREE_CHAIN (v2
);
2208 return (operand_equal_p (TREE_REALPART (arg0
), TREE_REALPART (arg1
),
2210 && operand_equal_p (TREE_IMAGPART (arg0
), TREE_IMAGPART (arg1
),
2214 return (TREE_STRING_LENGTH (arg0
) == TREE_STRING_LENGTH (arg1
)
2215 && ! memcmp (TREE_STRING_POINTER (arg0
),
2216 TREE_STRING_POINTER (arg1
),
2217 TREE_STRING_LENGTH (arg0
)));
2220 return operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0),
2229 switch (TREE_CODE_CLASS (TREE_CODE (arg0
)))
2232 /* Two conversions are equal only if signedness and modes match. */
2233 if ((TREE_CODE (arg0
) == NOP_EXPR
|| TREE_CODE (arg0
) == CONVERT_EXPR
)
2234 && (TREE_UNSIGNED (TREE_TYPE (arg0
))
2235 != TREE_UNSIGNED (TREE_TYPE (arg1
))))
2238 return operand_equal_p (TREE_OPERAND (arg0
, 0),
2239 TREE_OPERAND (arg1
, 0), 0);
2243 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0)
2244 && operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1),
2248 /* For commutative ops, allow the other order. */
2249 return (commutative_tree_code (TREE_CODE (arg0
))
2250 && operand_equal_p (TREE_OPERAND (arg0
, 0),
2251 TREE_OPERAND (arg1
, 1), 0)
2252 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2253 TREE_OPERAND (arg1
, 0), 0));
2256 /* If either of the pointer (or reference) expressions we are
2257 dereferencing contain a side effect, these cannot be equal. */
2258 if (TREE_SIDE_EFFECTS (arg0
)
2259 || TREE_SIDE_EFFECTS (arg1
))
2262 switch (TREE_CODE (arg0
))
2265 return operand_equal_p (TREE_OPERAND (arg0
, 0),
2266 TREE_OPERAND (arg1
, 0), 0);
2270 case ARRAY_RANGE_REF
:
2271 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
2272 TREE_OPERAND (arg1
, 0), 0)
2273 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2274 TREE_OPERAND (arg1
, 1), 0));
2277 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
2278 TREE_OPERAND (arg1
, 0), 0)
2279 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2280 TREE_OPERAND (arg1
, 1), 0)
2281 && operand_equal_p (TREE_OPERAND (arg0
, 2),
2282 TREE_OPERAND (arg1
, 2), 0));
2288 switch (TREE_CODE (arg0
))
2291 case TRUTH_NOT_EXPR
:
2292 return operand_equal_p (TREE_OPERAND (arg0
, 0),
2293 TREE_OPERAND (arg1
, 0), 0);
2296 return rtx_equal_p (RTL_EXPR_RTL (arg0
), RTL_EXPR_RTL (arg1
));
2299 /* If the CALL_EXPRs call different functions, then they
2300 clearly can not be equal. */
2301 if (! operand_equal_p (TREE_OPERAND (arg0
, 0),
2302 TREE_OPERAND (arg1
, 0), 0))
2305 /* Only consider const functions equivalent. */
2306 fndecl
= get_callee_fndecl (arg0
);
2307 if (fndecl
== NULL_TREE
2308 || ! (flags_from_decl_or_type (fndecl
) & ECF_CONST
))
2311 /* Now see if all the arguments are the same. operand_equal_p
2312 does not handle TREE_LIST, so we walk the operands here
2313 feeding them to operand_equal_p. */
2314 arg0
= TREE_OPERAND (arg0
, 1);
2315 arg1
= TREE_OPERAND (arg1
, 1);
2316 while (arg0
&& arg1
)
2318 if (! operand_equal_p (TREE_VALUE (arg0
), TREE_VALUE (arg1
), 0))
2321 arg0
= TREE_CHAIN (arg0
);
2322 arg1
= TREE_CHAIN (arg1
);
2325 /* If we get here and both argument lists are exhausted
2326 then the CALL_EXPRs are equal. */
2327 return ! (arg0
|| arg1
);
2334 /* Consider __builtin_sqrt equal to sqrt. */
2335 return TREE_CODE (arg0
) == FUNCTION_DECL
2336 && DECL_BUILT_IN (arg0
) && DECL_BUILT_IN (arg1
)
2337 && DECL_BUILT_IN_CLASS (arg0
) == DECL_BUILT_IN_CLASS (arg1
)
2338 && DECL_FUNCTION_CODE (arg0
) == DECL_FUNCTION_CODE (arg1
);
2345 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2346 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2348 When in doubt, return 0. */
2351 operand_equal_for_comparison_p (tree arg0
, tree arg1
, tree other
)
2353 int unsignedp1
, unsignedpo
;
2354 tree primarg0
, primarg1
, primother
;
2355 unsigned int correct_width
;
2357 if (operand_equal_p (arg0
, arg1
, 0))
2360 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
2361 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
2364 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2365 and see if the inner values are the same. This removes any
2366 signedness comparison, which doesn't matter here. */
2367 primarg0
= arg0
, primarg1
= arg1
;
2368 STRIP_NOPS (primarg0
);
2369 STRIP_NOPS (primarg1
);
2370 if (operand_equal_p (primarg0
, primarg1
, 0))
2373 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2374 actual comparison operand, ARG0.
2376 First throw away any conversions to wider types
2377 already present in the operands. */
2379 primarg1
= get_narrower (arg1
, &unsignedp1
);
2380 primother
= get_narrower (other
, &unsignedpo
);
2382 correct_width
= TYPE_PRECISION (TREE_TYPE (arg1
));
2383 if (unsignedp1
== unsignedpo
2384 && TYPE_PRECISION (TREE_TYPE (primarg1
)) < correct_width
2385 && TYPE_PRECISION (TREE_TYPE (primother
)) < correct_width
)
2387 tree type
= TREE_TYPE (arg0
);
2389 /* Make sure shorter operand is extended the right way
2390 to match the longer operand. */
2391 primarg1
= fold_convert ((*lang_hooks
.types
.signed_or_unsigned_type
)
2392 (unsignedp1
, TREE_TYPE (primarg1
)), primarg1
);
2394 if (operand_equal_p (arg0
, fold_convert (type
, primarg1
), 0))
2401 /* See if ARG is an expression that is either a comparison or is performing
2402 arithmetic on comparisons. The comparisons must only be comparing
2403 two different values, which will be stored in *CVAL1 and *CVAL2; if
2404 they are nonzero it means that some operands have already been found.
2405 No variables may be used anywhere else in the expression except in the
2406 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2407 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2409 If this is true, return 1. Otherwise, return zero. */
2412 twoval_comparison_p (tree arg
, tree
*cval1
, tree
*cval2
, int *save_p
)
2414 enum tree_code code
= TREE_CODE (arg
);
2415 char class = TREE_CODE_CLASS (code
);
2417 /* We can handle some of the 'e' cases here. */
2418 if (class == 'e' && code
== TRUTH_NOT_EXPR
)
2420 else if (class == 'e'
2421 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
2422 || code
== COMPOUND_EXPR
))
2425 else if (class == 'e' && code
== SAVE_EXPR
&& SAVE_EXPR_RTL (arg
) == 0
2426 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg
, 0)))
2428 /* If we've already found a CVAL1 or CVAL2, this expression is
2429 two complex to handle. */
2430 if (*cval1
|| *cval2
)
2440 return twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
);
2443 return (twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
)
2444 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2445 cval1
, cval2
, save_p
));
2451 if (code
== COND_EXPR
)
2452 return (twoval_comparison_p (TREE_OPERAND (arg
, 0),
2453 cval1
, cval2
, save_p
)
2454 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2455 cval1
, cval2
, save_p
)
2456 && twoval_comparison_p (TREE_OPERAND (arg
, 2),
2457 cval1
, cval2
, save_p
));
2461 /* First see if we can handle the first operand, then the second. For
2462 the second operand, we know *CVAL1 can't be zero. It must be that
2463 one side of the comparison is each of the values; test for the
2464 case where this isn't true by failing if the two operands
2467 if (operand_equal_p (TREE_OPERAND (arg
, 0),
2468 TREE_OPERAND (arg
, 1), 0))
2472 *cval1
= TREE_OPERAND (arg
, 0);
2473 else if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 0), 0))
2475 else if (*cval2
== 0)
2476 *cval2
= TREE_OPERAND (arg
, 0);
2477 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 0), 0))
2482 if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 1), 0))
2484 else if (*cval2
== 0)
2485 *cval2
= TREE_OPERAND (arg
, 1);
2486 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 1), 0))
2498 /* ARG is a tree that is known to contain just arithmetic operations and
2499 comparisons. Evaluate the operations in the tree substituting NEW0 for
2500 any occurrence of OLD0 as an operand of a comparison and likewise for
2504 eval_subst (tree arg
, tree old0
, tree new0
, tree old1
, tree new1
)
2506 tree type
= TREE_TYPE (arg
);
2507 enum tree_code code
= TREE_CODE (arg
);
2508 char class = TREE_CODE_CLASS (code
);
2510 /* We can handle some of the 'e' cases here. */
2511 if (class == 'e' && code
== TRUTH_NOT_EXPR
)
2513 else if (class == 'e'
2514 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
))
2520 return fold (build1 (code
, type
,
2521 eval_subst (TREE_OPERAND (arg
, 0),
2522 old0
, new0
, old1
, new1
)));
2525 return fold (build (code
, type
,
2526 eval_subst (TREE_OPERAND (arg
, 0),
2527 old0
, new0
, old1
, new1
),
2528 eval_subst (TREE_OPERAND (arg
, 1),
2529 old0
, new0
, old1
, new1
)));
2535 return eval_subst (TREE_OPERAND (arg
, 0), old0
, new0
, old1
, new1
);
2538 return eval_subst (TREE_OPERAND (arg
, 1), old0
, new0
, old1
, new1
);
2541 return fold (build (code
, type
,
2542 eval_subst (TREE_OPERAND (arg
, 0),
2543 old0
, new0
, old1
, new1
),
2544 eval_subst (TREE_OPERAND (arg
, 1),
2545 old0
, new0
, old1
, new1
),
2546 eval_subst (TREE_OPERAND (arg
, 2),
2547 old0
, new0
, old1
, new1
)));
2551 /* Fall through - ??? */
2555 tree arg0
= TREE_OPERAND (arg
, 0);
2556 tree arg1
= TREE_OPERAND (arg
, 1);
2558 /* We need to check both for exact equality and tree equality. The
2559 former will be true if the operand has a side-effect. In that
2560 case, we know the operand occurred exactly once. */
2562 if (arg0
== old0
|| operand_equal_p (arg0
, old0
, 0))
2564 else if (arg0
== old1
|| operand_equal_p (arg0
, old1
, 0))
2567 if (arg1
== old0
|| operand_equal_p (arg1
, old0
, 0))
2569 else if (arg1
== old1
|| operand_equal_p (arg1
, old1
, 0))
2572 return fold (build (code
, type
, arg0
, arg1
));
2580 /* Return a tree for the case when the result of an expression is RESULT
2581 converted to TYPE and OMITTED was previously an operand of the expression
2582 but is now not needed (e.g., we folded OMITTED * 0).
2584 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2585 the conversion of RESULT to TYPE. */
2588 omit_one_operand (tree type
, tree result
, tree omitted
)
2590 tree t
= fold_convert (type
, result
);
2592 if (TREE_SIDE_EFFECTS (omitted
))
2593 return build (COMPOUND_EXPR
, type
, omitted
, t
);
2595 return non_lvalue (t
);
2598 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2601 pedantic_omit_one_operand (tree type
, tree result
, tree omitted
)
2603 tree t
= fold_convert (type
, result
);
2605 if (TREE_SIDE_EFFECTS (omitted
))
2606 return build (COMPOUND_EXPR
, type
, omitted
, t
);
2608 return pedantic_non_lvalue (t
);
2611 /* Return a simplified tree node for the truth-negation of ARG. This
2612 never alters ARG itself. We assume that ARG is an operation that
2613 returns a truth value (0 or 1). */
2616 invert_truthvalue (tree arg
)
2618 tree type
= TREE_TYPE (arg
);
2619 enum tree_code code
= TREE_CODE (arg
);
2621 if (code
== ERROR_MARK
)
2624 /* If this is a comparison, we can simply invert it, except for
2625 floating-point non-equality comparisons, in which case we just
2626 enclose a TRUTH_NOT_EXPR around what we have. */
2628 if (TREE_CODE_CLASS (code
) == '<')
2630 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg
, 0)))
2631 && !flag_unsafe_math_optimizations
2634 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2635 else if (code
== UNORDERED_EXPR
2636 || code
== ORDERED_EXPR
2637 || code
== UNEQ_EXPR
2638 || code
== UNLT_EXPR
2639 || code
== UNLE_EXPR
2640 || code
== UNGT_EXPR
2641 || code
== UNGE_EXPR
)
2642 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2644 return build (invert_tree_comparison (code
), type
,
2645 TREE_OPERAND (arg
, 0), TREE_OPERAND (arg
, 1));
2651 return fold_convert (type
, build_int_2 (integer_zerop (arg
), 0));
2653 case TRUTH_AND_EXPR
:
2654 return build (TRUTH_OR_EXPR
, type
,
2655 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2656 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2659 return build (TRUTH_AND_EXPR
, type
,
2660 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2661 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2663 case TRUTH_XOR_EXPR
:
2664 /* Here we can invert either operand. We invert the first operand
2665 unless the second operand is a TRUTH_NOT_EXPR in which case our
2666 result is the XOR of the first operand with the inside of the
2667 negation of the second operand. */
2669 if (TREE_CODE (TREE_OPERAND (arg
, 1)) == TRUTH_NOT_EXPR
)
2670 return build (TRUTH_XOR_EXPR
, type
, TREE_OPERAND (arg
, 0),
2671 TREE_OPERAND (TREE_OPERAND (arg
, 1), 0));
2673 return build (TRUTH_XOR_EXPR
, type
,
2674 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2675 TREE_OPERAND (arg
, 1));
2677 case TRUTH_ANDIF_EXPR
:
2678 return build (TRUTH_ORIF_EXPR
, type
,
2679 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2680 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2682 case TRUTH_ORIF_EXPR
:
2683 return build (TRUTH_ANDIF_EXPR
, type
,
2684 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2685 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2687 case TRUTH_NOT_EXPR
:
2688 return TREE_OPERAND (arg
, 0);
2691 return build (COND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2692 invert_truthvalue (TREE_OPERAND (arg
, 1)),
2693 invert_truthvalue (TREE_OPERAND (arg
, 2)));
2696 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2697 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2699 case WITH_RECORD_EXPR
:
2700 return build (WITH_RECORD_EXPR
, type
,
2701 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2702 TREE_OPERAND (arg
, 1));
2704 case NON_LVALUE_EXPR
:
2705 return invert_truthvalue (TREE_OPERAND (arg
, 0));
2710 return build1 (TREE_CODE (arg
), type
,
2711 invert_truthvalue (TREE_OPERAND (arg
, 0)));
2714 if (!integer_onep (TREE_OPERAND (arg
, 1)))
2716 return build (EQ_EXPR
, type
, arg
,
2717 fold_convert (type
, integer_zero_node
));
2720 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2722 case CLEANUP_POINT_EXPR
:
2723 return build1 (CLEANUP_POINT_EXPR
, type
,
2724 invert_truthvalue (TREE_OPERAND (arg
, 0)));
2729 if (TREE_CODE (TREE_TYPE (arg
)) != BOOLEAN_TYPE
)
2731 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2734 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2735 operands are another bit-wise operation with a common input. If so,
2736 distribute the bit operations to save an operation and possibly two if
2737 constants are involved. For example, convert
2738 (A | B) & (A | C) into A | (B & C)
2739 Further simplification will occur if B and C are constants.
2741 If this optimization cannot be done, 0 will be returned. */
2744 distribute_bit_expr (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
2749 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
2750 || TREE_CODE (arg0
) == code
2751 || (TREE_CODE (arg0
) != BIT_AND_EXPR
2752 && TREE_CODE (arg0
) != BIT_IOR_EXPR
))
2755 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0))
2757 common
= TREE_OPERAND (arg0
, 0);
2758 left
= TREE_OPERAND (arg0
, 1);
2759 right
= TREE_OPERAND (arg1
, 1);
2761 else if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 1), 0))
2763 common
= TREE_OPERAND (arg0
, 0);
2764 left
= TREE_OPERAND (arg0
, 1);
2765 right
= TREE_OPERAND (arg1
, 0);
2767 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 0), 0))
2769 common
= TREE_OPERAND (arg0
, 1);
2770 left
= TREE_OPERAND (arg0
, 0);
2771 right
= TREE_OPERAND (arg1
, 1);
2773 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1), 0))
2775 common
= TREE_OPERAND (arg0
, 1);
2776 left
= TREE_OPERAND (arg0
, 0);
2777 right
= TREE_OPERAND (arg1
, 0);
2782 return fold (build (TREE_CODE (arg0
), type
, common
,
2783 fold (build (code
, type
, left
, right
))));
2786 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2787 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2790 make_bit_field_ref (tree inner
, tree type
, int bitsize
, int bitpos
,
2793 tree result
= build (BIT_FIELD_REF
, type
, inner
,
2794 size_int (bitsize
), bitsize_int (bitpos
));
2796 TREE_UNSIGNED (result
) = unsignedp
;
2801 /* Optimize a bit-field compare.
2803 There are two cases: First is a compare against a constant and the
2804 second is a comparison of two items where the fields are at the same
2805 bit position relative to the start of a chunk (byte, halfword, word)
2806 large enough to contain it. In these cases we can avoid the shift
2807 implicit in bitfield extractions.
2809 For constants, we emit a compare of the shifted constant with the
2810 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2811 compared. For two fields at the same position, we do the ANDs with the
2812 similar mask and compare the result of the ANDs.
2814 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2815 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2816 are the left and right operands of the comparison, respectively.
2818 If the optimization described above can be done, we return the resulting
2819 tree. Otherwise we return zero. */
2822 optimize_bit_field_compare (enum tree_code code
, tree compare_type
,
2825 HOST_WIDE_INT lbitpos
, lbitsize
, rbitpos
, rbitsize
, nbitpos
, nbitsize
;
2826 tree type
= TREE_TYPE (lhs
);
2827 tree signed_type
, unsigned_type
;
2828 int const_p
= TREE_CODE (rhs
) == INTEGER_CST
;
2829 enum machine_mode lmode
, rmode
, nmode
;
2830 int lunsignedp
, runsignedp
;
2831 int lvolatilep
= 0, rvolatilep
= 0;
2832 tree linner
, rinner
= NULL_TREE
;
2836 /* Get all the information about the extractions being done. If the bit size
2837 if the same as the size of the underlying object, we aren't doing an
2838 extraction at all and so can do nothing. We also don't want to
2839 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2840 then will no longer be able to replace it. */
2841 linner
= get_inner_reference (lhs
, &lbitsize
, &lbitpos
, &offset
, &lmode
,
2842 &lunsignedp
, &lvolatilep
);
2843 if (linner
== lhs
|| lbitsize
== GET_MODE_BITSIZE (lmode
) || lbitsize
< 0
2844 || offset
!= 0 || TREE_CODE (linner
) == PLACEHOLDER_EXPR
)
2849 /* If this is not a constant, we can only do something if bit positions,
2850 sizes, and signedness are the same. */
2851 rinner
= get_inner_reference (rhs
, &rbitsize
, &rbitpos
, &offset
, &rmode
,
2852 &runsignedp
, &rvolatilep
);
2854 if (rinner
== rhs
|| lbitpos
!= rbitpos
|| lbitsize
!= rbitsize
2855 || lunsignedp
!= runsignedp
|| offset
!= 0
2856 || TREE_CODE (rinner
) == PLACEHOLDER_EXPR
)
2860 /* See if we can find a mode to refer to this field. We should be able to,
2861 but fail if we can't. */
2862 nmode
= get_best_mode (lbitsize
, lbitpos
,
2863 const_p
? TYPE_ALIGN (TREE_TYPE (linner
))
2864 : MIN (TYPE_ALIGN (TREE_TYPE (linner
)),
2865 TYPE_ALIGN (TREE_TYPE (rinner
))),
2866 word_mode
, lvolatilep
|| rvolatilep
);
2867 if (nmode
== VOIDmode
)
2870 /* Set signed and unsigned types of the precision of this mode for the
2872 signed_type
= (*lang_hooks
.types
.type_for_mode
) (nmode
, 0);
2873 unsigned_type
= (*lang_hooks
.types
.type_for_mode
) (nmode
, 1);
2875 /* Compute the bit position and size for the new reference and our offset
2876 within it. If the new reference is the same size as the original, we
2877 won't optimize anything, so return zero. */
2878 nbitsize
= GET_MODE_BITSIZE (nmode
);
2879 nbitpos
= lbitpos
& ~ (nbitsize
- 1);
2881 if (nbitsize
== lbitsize
)
2884 if (BYTES_BIG_ENDIAN
)
2885 lbitpos
= nbitsize
- lbitsize
- lbitpos
;
2887 /* Make the mask to be used against the extracted field. */
2888 mask
= build_int_2 (~0, ~0);
2889 TREE_TYPE (mask
) = unsigned_type
;
2890 force_fit_type (mask
, 0);
2891 mask
= fold_convert (unsigned_type
, mask
);
2892 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (nbitsize
- lbitsize
), 0);
2893 mask
= const_binop (RSHIFT_EXPR
, mask
,
2894 size_int (nbitsize
- lbitsize
- lbitpos
), 0);
2897 /* If not comparing with constant, just rework the comparison
2899 return build (code
, compare_type
,
2900 build (BIT_AND_EXPR
, unsigned_type
,
2901 make_bit_field_ref (linner
, unsigned_type
,
2902 nbitsize
, nbitpos
, 1),
2904 build (BIT_AND_EXPR
, unsigned_type
,
2905 make_bit_field_ref (rinner
, unsigned_type
,
2906 nbitsize
, nbitpos
, 1),
2909 /* Otherwise, we are handling the constant case. See if the constant is too
2910 big for the field. Warn and return a tree of for 0 (false) if so. We do
2911 this not only for its own sake, but to avoid having to test for this
2912 error case below. If we didn't, we might generate wrong code.
2914 For unsigned fields, the constant shifted right by the field length should
2915 be all zero. For signed fields, the high-order bits should agree with
2920 if (! integer_zerop (const_binop (RSHIFT_EXPR
,
2921 fold_convert (unsigned_type
, rhs
),
2922 size_int (lbitsize
), 0)))
2924 warning ("comparison is always %d due to width of bit-field",
2926 return fold_convert (compare_type
,
2928 ? integer_one_node
: integer_zero_node
));
2933 tree tem
= const_binop (RSHIFT_EXPR
, fold_convert (signed_type
, rhs
),
2934 size_int (lbitsize
- 1), 0);
2935 if (! integer_zerop (tem
) && ! integer_all_onesp (tem
))
2937 warning ("comparison is always %d due to width of bit-field",
2939 return fold_convert (compare_type
,
2941 ? integer_one_node
: integer_zero_node
));
2945 /* Single-bit compares should always be against zero. */
2946 if (lbitsize
== 1 && ! integer_zerop (rhs
))
2948 code
= code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
;
2949 rhs
= fold_convert (type
, integer_zero_node
);
2952 /* Make a new bitfield reference, shift the constant over the
2953 appropriate number of bits and mask it with the computed mask
2954 (in case this was a signed field). If we changed it, make a new one. */
2955 lhs
= make_bit_field_ref (linner
, unsigned_type
, nbitsize
, nbitpos
, 1);
2958 TREE_SIDE_EFFECTS (lhs
) = 1;
2959 TREE_THIS_VOLATILE (lhs
) = 1;
2962 rhs
= fold (const_binop (BIT_AND_EXPR
,
2963 const_binop (LSHIFT_EXPR
,
2964 fold_convert (unsigned_type
, rhs
),
2965 size_int (lbitpos
), 0),
2968 return build (code
, compare_type
,
2969 build (BIT_AND_EXPR
, unsigned_type
, lhs
, mask
),
2973 /* Subroutine for fold_truthop: decode a field reference.
2975 If EXP is a comparison reference, we return the innermost reference.
2977 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2978 set to the starting bit number.
2980 If the innermost field can be completely contained in a mode-sized
2981 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2983 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2984 otherwise it is not changed.
2986 *PUNSIGNEDP is set to the signedness of the field.
2988 *PMASK is set to the mask used. This is either contained in a
2989 BIT_AND_EXPR or derived from the width of the field.
2991 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2993 Return 0 if this is not a component reference or is one that we can't
2994 do anything with. */
2997 decode_field_reference (tree exp
, HOST_WIDE_INT
*pbitsize
,
2998 HOST_WIDE_INT
*pbitpos
, enum machine_mode
*pmode
,
2999 int *punsignedp
, int *pvolatilep
,
3000 tree
*pmask
, tree
*pand_mask
)
3002 tree outer_type
= 0;
3004 tree mask
, inner
, offset
;
3006 unsigned int precision
;
3008 /* All the optimizations using this function assume integer fields.
3009 There are problems with FP fields since the type_for_size call
3010 below can fail for, e.g., XFmode. */
3011 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp
)))
3014 /* We are interested in the bare arrangement of bits, so strip everything
3015 that doesn't affect the machine mode. However, record the type of the
3016 outermost expression if it may matter below. */
3017 if (TREE_CODE (exp
) == NOP_EXPR
3018 || TREE_CODE (exp
) == CONVERT_EXPR
3019 || TREE_CODE (exp
) == NON_LVALUE_EXPR
)
3020 outer_type
= TREE_TYPE (exp
);
3023 if (TREE_CODE (exp
) == BIT_AND_EXPR
)
3025 and_mask
= TREE_OPERAND (exp
, 1);
3026 exp
= TREE_OPERAND (exp
, 0);
3027 STRIP_NOPS (exp
); STRIP_NOPS (and_mask
);
3028 if (TREE_CODE (and_mask
) != INTEGER_CST
)
3032 inner
= get_inner_reference (exp
, pbitsize
, pbitpos
, &offset
, pmode
,
3033 punsignedp
, pvolatilep
);
3034 if ((inner
== exp
&& and_mask
== 0)
3035 || *pbitsize
< 0 || offset
!= 0
3036 || TREE_CODE (inner
) == PLACEHOLDER_EXPR
)
3039 /* If the number of bits in the reference is the same as the bitsize of
3040 the outer type, then the outer type gives the signedness. Otherwise
3041 (in case of a small bitfield) the signedness is unchanged. */
3042 if (outer_type
&& *pbitsize
== tree_low_cst (TYPE_SIZE (outer_type
), 1))
3043 *punsignedp
= TREE_UNSIGNED (outer_type
);
3045 /* Compute the mask to access the bitfield. */
3046 unsigned_type
= (*lang_hooks
.types
.type_for_size
) (*pbitsize
, 1);
3047 precision
= TYPE_PRECISION (unsigned_type
);
3049 mask
= build_int_2 (~0, ~0);
3050 TREE_TYPE (mask
) = unsigned_type
;
3051 force_fit_type (mask
, 0);
3052 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
3053 mask
= const_binop (RSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
3055 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3057 mask
= fold (build (BIT_AND_EXPR
, unsigned_type
,
3058 fold_convert (unsigned_type
, and_mask
), mask
));
3061 *pand_mask
= and_mask
;
3065 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3069 all_ones_mask_p (tree mask
, int size
)
3071 tree type
= TREE_TYPE (mask
);
3072 unsigned int precision
= TYPE_PRECISION (type
);
3075 tmask
= build_int_2 (~0, ~0);
3076 TREE_TYPE (tmask
) = (*lang_hooks
.types
.signed_type
) (type
);
3077 force_fit_type (tmask
, 0);
3079 tree_int_cst_equal (mask
,
3080 const_binop (RSHIFT_EXPR
,
3081 const_binop (LSHIFT_EXPR
, tmask
,
3082 size_int (precision
- size
),
3084 size_int (precision
- size
), 0));
3087 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3088 represents the sign bit of EXP's type. If EXP represents a sign
3089 or zero extension, also test VAL against the unextended type.
3090 The return value is the (sub)expression whose sign bit is VAL,
3091 or NULL_TREE otherwise. */
3094 sign_bit_p (tree exp
, tree val
)
3096 unsigned HOST_WIDE_INT mask_lo
, lo
;
3097 HOST_WIDE_INT mask_hi
, hi
;
3101 /* Tree EXP must have an integral type. */
3102 t
= TREE_TYPE (exp
);
3103 if (! INTEGRAL_TYPE_P (t
))
3106 /* Tree VAL must be an integer constant. */
3107 if (TREE_CODE (val
) != INTEGER_CST
3108 || TREE_CONSTANT_OVERFLOW (val
))
3111 width
= TYPE_PRECISION (t
);
3112 if (width
> HOST_BITS_PER_WIDE_INT
)
3114 hi
= (unsigned HOST_WIDE_INT
) 1 << (width
- HOST_BITS_PER_WIDE_INT
- 1);
3117 mask_hi
= ((unsigned HOST_WIDE_INT
) -1
3118 >> (2 * HOST_BITS_PER_WIDE_INT
- width
));
3124 lo
= (unsigned HOST_WIDE_INT
) 1 << (width
- 1);
3127 mask_lo
= ((unsigned HOST_WIDE_INT
) -1
3128 >> (HOST_BITS_PER_WIDE_INT
- width
));
3131 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3132 treat VAL as if it were unsigned. */
3133 if ((TREE_INT_CST_HIGH (val
) & mask_hi
) == hi
3134 && (TREE_INT_CST_LOW (val
) & mask_lo
) == lo
)
3137 /* Handle extension from a narrower type. */
3138 if (TREE_CODE (exp
) == NOP_EXPR
3139 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp
, 0))) < width
)
3140 return sign_bit_p (TREE_OPERAND (exp
, 0), val
);
3145 /* Subroutine for fold_truthop: determine if an operand is simple enough
3146 to be evaluated unconditionally. */
3149 simple_operand_p (tree exp
)
3151 /* Strip any conversions that don't change the machine mode. */
3152 while ((TREE_CODE (exp
) == NOP_EXPR
3153 || TREE_CODE (exp
) == CONVERT_EXPR
)
3154 && (TYPE_MODE (TREE_TYPE (exp
))
3155 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp
, 0)))))
3156 exp
= TREE_OPERAND (exp
, 0);
3158 return (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'c'
3160 && ! TREE_ADDRESSABLE (exp
)
3161 && ! TREE_THIS_VOLATILE (exp
)
3162 && ! DECL_NONLOCAL (exp
)
3163 /* Don't regard global variables as simple. They may be
3164 allocated in ways unknown to the compiler (shared memory,
3165 #pragma weak, etc). */
3166 && ! TREE_PUBLIC (exp
)
3167 && ! DECL_EXTERNAL (exp
)
3168 /* Loading a static variable is unduly expensive, but global
3169 registers aren't expensive. */
3170 && (! TREE_STATIC (exp
) || DECL_REGISTER (exp
))));
3173 /* The following functions are subroutines to fold_range_test and allow it to
3174 try to change a logical combination of comparisons into a range test.
3177 X == 2 || X == 3 || X == 4 || X == 5
3181 (unsigned) (X - 2) <= 3
3183 We describe each set of comparisons as being either inside or outside
3184 a range, using a variable named like IN_P, and then describe the
3185 range with a lower and upper bound. If one of the bounds is omitted,
3186 it represents either the highest or lowest value of the type.
3188 In the comments below, we represent a range by two numbers in brackets
3189 preceded by a "+" to designate being inside that range, or a "-" to
3190 designate being outside that range, so the condition can be inverted by
3191 flipping the prefix. An omitted bound is represented by a "-". For
3192 example, "- [-, 10]" means being outside the range starting at the lowest
3193 possible value and ending at 10, in other words, being greater than 10.
3194 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3197 We set up things so that the missing bounds are handled in a consistent
3198 manner so neither a missing bound nor "true" and "false" need to be
3199 handled using a special case. */
3201 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3202 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3203 and UPPER1_P are nonzero if the respective argument is an upper bound
3204 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3205 must be specified for a comparison. ARG1 will be converted to ARG0's
3206 type if both are specified. */
3209 range_binop (enum tree_code code
, tree type
, tree arg0
, int upper0_p
,
3210 tree arg1
, int upper1_p
)
3216 /* If neither arg represents infinity, do the normal operation.
3217 Else, if not a comparison, return infinity. Else handle the special
3218 comparison rules. Note that most of the cases below won't occur, but
3219 are handled for consistency. */
3221 if (arg0
!= 0 && arg1
!= 0)
3223 tem
= fold (build (code
, type
!= 0 ? type
: TREE_TYPE (arg0
),
3224 arg0
, fold_convert (TREE_TYPE (arg0
), arg1
)));
3226 return TREE_CODE (tem
) == INTEGER_CST
? tem
: 0;
3229 if (TREE_CODE_CLASS (code
) != '<')
3232 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3233 for neither. In real maths, we cannot assume open ended ranges are
3234 the same. But, this is computer arithmetic, where numbers are finite.
3235 We can therefore make the transformation of any unbounded range with
3236 the value Z, Z being greater than any representable number. This permits
3237 us to treat unbounded ranges as equal. */
3238 sgn0
= arg0
!= 0 ? 0 : (upper0_p
? 1 : -1);
3239 sgn1
= arg1
!= 0 ? 0 : (upper1_p
? 1 : -1);
3243 result
= sgn0
== sgn1
;
3246 result
= sgn0
!= sgn1
;
3249 result
= sgn0
< sgn1
;
3252 result
= sgn0
<= sgn1
;
3255 result
= sgn0
> sgn1
;
3258 result
= sgn0
>= sgn1
;
3264 return fold_convert (type
, result
? integer_one_node
: integer_zero_node
);
3267 /* Given EXP, a logical expression, set the range it is testing into
3268 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3269 actually being tested. *PLOW and *PHIGH will be made of the same type
3270 as the returned expression. If EXP is not a comparison, we will most
3271 likely not be returning a useful value and range. */
3274 make_range (tree exp
, int *pin_p
, tree
*plow
, tree
*phigh
)
3276 enum tree_code code
;
3277 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
, type
= NULL_TREE
;
3278 tree orig_type
= NULL_TREE
;
3280 tree low
, high
, n_low
, n_high
;
3282 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3283 and see if we can refine the range. Some of the cases below may not
3284 happen, but it doesn't seem worth worrying about this. We "continue"
3285 the outer loop when we've changed something; otherwise we "break"
3286 the switch, which will "break" the while. */
3289 low
= high
= fold_convert (TREE_TYPE (exp
), integer_zero_node
);
3293 code
= TREE_CODE (exp
);
3295 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code
)))
3297 if (first_rtl_op (code
) > 0)
3298 arg0
= TREE_OPERAND (exp
, 0);
3299 if (TREE_CODE_CLASS (code
) == '<'
3300 || TREE_CODE_CLASS (code
) == '1'
3301 || TREE_CODE_CLASS (code
) == '2')
3302 type
= TREE_TYPE (arg0
);
3303 if (TREE_CODE_CLASS (code
) == '2'
3304 || TREE_CODE_CLASS (code
) == '<'
3305 || (TREE_CODE_CLASS (code
) == 'e'
3306 && TREE_CODE_LENGTH (code
) > 1))
3307 arg1
= TREE_OPERAND (exp
, 1);
3310 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3311 lose a cast by accident. */
3312 if (type
!= NULL_TREE
&& orig_type
== NULL_TREE
)
3317 case TRUTH_NOT_EXPR
:
3318 in_p
= ! in_p
, exp
= arg0
;
3321 case EQ_EXPR
: case NE_EXPR
:
3322 case LT_EXPR
: case LE_EXPR
: case GE_EXPR
: case GT_EXPR
:
3323 /* We can only do something if the range is testing for zero
3324 and if the second operand is an integer constant. Note that
3325 saying something is "in" the range we make is done by
3326 complementing IN_P since it will set in the initial case of
3327 being not equal to zero; "out" is leaving it alone. */
3328 if (low
== 0 || high
== 0
3329 || ! integer_zerop (low
) || ! integer_zerop (high
)
3330 || TREE_CODE (arg1
) != INTEGER_CST
)
3335 case NE_EXPR
: /* - [c, c] */
3338 case EQ_EXPR
: /* + [c, c] */
3339 in_p
= ! in_p
, low
= high
= arg1
;
3341 case GT_EXPR
: /* - [-, c] */
3342 low
= 0, high
= arg1
;
3344 case GE_EXPR
: /* + [c, -] */
3345 in_p
= ! in_p
, low
= arg1
, high
= 0;
3347 case LT_EXPR
: /* - [c, -] */
3348 low
= arg1
, high
= 0;
3350 case LE_EXPR
: /* + [-, c] */
3351 in_p
= ! in_p
, low
= 0, high
= arg1
;
3359 /* If this is an unsigned comparison, we also know that EXP is
3360 greater than or equal to zero. We base the range tests we make
3361 on that fact, so we record it here so we can parse existing
3363 if (TREE_UNSIGNED (type
) && (low
== 0 || high
== 0))
3365 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
, in_p
, low
, high
,
3366 1, fold_convert (type
, integer_zero_node
),
3370 in_p
= n_in_p
, low
= n_low
, high
= n_high
;
3372 /* If the high bound is missing, but we have a nonzero low
3373 bound, reverse the range so it goes from zero to the low bound
3375 if (high
== 0 && low
&& ! integer_zerop (low
))
3378 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low
, 0,
3379 integer_one_node
, 0);
3380 low
= fold_convert (type
, integer_zero_node
);
3386 /* (-x) IN [a,b] -> x in [-b, -a] */
3387 n_low
= range_binop (MINUS_EXPR
, type
,
3388 fold_convert (type
, integer_zero_node
),
3390 n_high
= range_binop (MINUS_EXPR
, type
,
3391 fold_convert (type
, integer_zero_node
),
3393 low
= n_low
, high
= n_high
;
3399 exp
= build (MINUS_EXPR
, type
, negate_expr (arg0
),
3400 fold_convert (type
, integer_one_node
));
3403 case PLUS_EXPR
: case MINUS_EXPR
:
3404 if (TREE_CODE (arg1
) != INTEGER_CST
)
3407 /* If EXP is signed, any overflow in the computation is undefined,
3408 so we don't worry about it so long as our computations on
3409 the bounds don't overflow. For unsigned, overflow is defined
3410 and this is exactly the right thing. */
3411 n_low
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3412 type
, low
, 0, arg1
, 0);
3413 n_high
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3414 type
, high
, 1, arg1
, 0);
3415 if ((n_low
!= 0 && TREE_OVERFLOW (n_low
))
3416 || (n_high
!= 0 && TREE_OVERFLOW (n_high
)))
3419 /* Check for an unsigned range which has wrapped around the maximum
3420 value thus making n_high < n_low, and normalize it. */
3421 if (n_low
&& n_high
&& tree_int_cst_lt (n_high
, n_low
))
3423 low
= range_binop (PLUS_EXPR
, type
, n_high
, 0,
3424 integer_one_node
, 0);
3425 high
= range_binop (MINUS_EXPR
, type
, n_low
, 0,
3426 integer_one_node
, 0);
3428 /* If the range is of the form +/- [ x+1, x ], we won't
3429 be able to normalize it. But then, it represents the
3430 whole range or the empty set, so make it
3432 if (tree_int_cst_equal (n_low
, low
)
3433 && tree_int_cst_equal (n_high
, high
))
3439 low
= n_low
, high
= n_high
;
3444 case NOP_EXPR
: case NON_LVALUE_EXPR
: case CONVERT_EXPR
:
3445 if (TYPE_PRECISION (type
) > TYPE_PRECISION (orig_type
))
3448 if (! INTEGRAL_TYPE_P (type
)
3449 || (low
!= 0 && ! int_fits_type_p (low
, type
))
3450 || (high
!= 0 && ! int_fits_type_p (high
, type
)))
3453 n_low
= low
, n_high
= high
;
3456 n_low
= fold_convert (type
, n_low
);
3459 n_high
= fold_convert (type
, n_high
);
3461 /* If we're converting from an unsigned to a signed type,
3462 we will be doing the comparison as unsigned. The tests above
3463 have already verified that LOW and HIGH are both positive.
3465 So we have to make sure that the original unsigned value will
3466 be interpreted as positive. */
3467 if (TREE_UNSIGNED (type
) && ! TREE_UNSIGNED (TREE_TYPE (exp
)))
3469 tree equiv_type
= (*lang_hooks
.types
.type_for_mode
)
3470 (TYPE_MODE (type
), 1);
3473 /* A range without an upper bound is, naturally, unbounded.
3474 Since convert would have cropped a very large value, use
3475 the max value for the destination type. */
3477 = TYPE_MAX_VALUE (equiv_type
) ? TYPE_MAX_VALUE (equiv_type
)
3478 : TYPE_MAX_VALUE (type
);
3480 if (TYPE_PRECISION (type
) == TYPE_PRECISION (TREE_TYPE (exp
)))
3481 high_positive
= fold (build (RSHIFT_EXPR
, type
,
3485 integer_one_node
)));
3487 /* If the low bound is specified, "and" the range with the
3488 range for which the original unsigned value will be
3492 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3493 1, n_low
, n_high
, 1,
3494 fold_convert (type
, integer_zero_node
),
3498 in_p
= (n_in_p
== in_p
);
3502 /* Otherwise, "or" the range with the range of the input
3503 that will be interpreted as negative. */
3504 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3505 0, n_low
, n_high
, 1,
3506 fold_convert (type
, integer_zero_node
),
3510 in_p
= (in_p
!= n_in_p
);
3515 low
= n_low
, high
= n_high
;
3525 /* If EXP is a constant, we can evaluate whether this is true or false. */
3526 if (TREE_CODE (exp
) == INTEGER_CST
)
3528 in_p
= in_p
== (integer_onep (range_binop (GE_EXPR
, integer_type_node
,
3530 && integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3536 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
3540 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3541 type, TYPE, return an expression to test if EXP is in (or out of, depending
3542 on IN_P) the range. */
3545 build_range_check (tree type
, tree exp
, int in_p
, tree low
, tree high
)
3547 tree etype
= TREE_TYPE (exp
);
3551 && (0 != (value
= build_range_check (type
, exp
, 1, low
, high
))))
3552 return invert_truthvalue (value
);
3554 if (low
== 0 && high
== 0)
3555 return fold_convert (type
, integer_one_node
);
3558 return fold (build (LE_EXPR
, type
, exp
, high
));
3561 return fold (build (GE_EXPR
, type
, exp
, low
));
3563 if (operand_equal_p (low
, high
, 0))
3564 return fold (build (EQ_EXPR
, type
, exp
, low
));
3566 if (integer_zerop (low
))
3568 if (! TREE_UNSIGNED (etype
))
3570 etype
= (*lang_hooks
.types
.unsigned_type
) (etype
);
3571 high
= fold_convert (etype
, high
);
3572 exp
= fold_convert (etype
, exp
);
3574 return build_range_check (type
, exp
, 1, 0, high
);
3577 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3578 if (integer_onep (low
) && TREE_CODE (high
) == INTEGER_CST
)
3580 unsigned HOST_WIDE_INT lo
;
3584 prec
= TYPE_PRECISION (etype
);
3585 if (prec
<= HOST_BITS_PER_WIDE_INT
)
3588 lo
= ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1)) - 1;
3592 hi
= ((HOST_WIDE_INT
) 1 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)) - 1;
3593 lo
= (unsigned HOST_WIDE_INT
) -1;
3596 if (TREE_INT_CST_HIGH (high
) == hi
&& TREE_INT_CST_LOW (high
) == lo
)
3598 if (TREE_UNSIGNED (etype
))
3600 etype
= (*lang_hooks
.types
.signed_type
) (etype
);
3601 exp
= fold_convert (etype
, exp
);
3603 return fold (build (GT_EXPR
, type
, exp
,
3604 fold_convert (etype
, integer_zero_node
)));
3608 if (0 != (value
= const_binop (MINUS_EXPR
, high
, low
, 0))
3609 && ! TREE_OVERFLOW (value
))
3610 return build_range_check (type
,
3611 fold (build (MINUS_EXPR
, etype
, exp
, low
)),
3612 1, fold_convert (etype
, integer_zero_node
),
3618 /* Given two ranges, see if we can merge them into one. Return 1 if we
3619 can, 0 if we can't. Set the output range into the specified parameters. */
3622 merge_ranges (int *pin_p
, tree
*plow
, tree
*phigh
, int in0_p
, tree low0
,
3623 tree high0
, int in1_p
, tree low1
, tree high1
)
3631 int lowequal
= ((low0
== 0 && low1
== 0)
3632 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3633 low0
, 0, low1
, 0)));
3634 int highequal
= ((high0
== 0 && high1
== 0)
3635 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3636 high0
, 1, high1
, 1)));
3638 /* Make range 0 be the range that starts first, or ends last if they
3639 start at the same value. Swap them if it isn't. */
3640 if (integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3643 && integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3644 high1
, 1, high0
, 1))))
3646 temp
= in0_p
, in0_p
= in1_p
, in1_p
= temp
;
3647 tem
= low0
, low0
= low1
, low1
= tem
;
3648 tem
= high0
, high0
= high1
, high1
= tem
;
3651 /* Now flag two cases, whether the ranges are disjoint or whether the
3652 second range is totally subsumed in the first. Note that the tests
3653 below are simplified by the ones above. */
3654 no_overlap
= integer_onep (range_binop (LT_EXPR
, integer_type_node
,
3655 high0
, 1, low1
, 0));
3656 subset
= integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3657 high1
, 1, high0
, 1));
3659 /* We now have four cases, depending on whether we are including or
3660 excluding the two ranges. */
3663 /* If they don't overlap, the result is false. If the second range
3664 is a subset it is the result. Otherwise, the range is from the start
3665 of the second to the end of the first. */
3667 in_p
= 0, low
= high
= 0;
3669 in_p
= 1, low
= low1
, high
= high1
;
3671 in_p
= 1, low
= low1
, high
= high0
;
3674 else if (in0_p
&& ! in1_p
)
3676 /* If they don't overlap, the result is the first range. If they are
3677 equal, the result is false. If the second range is a subset of the
3678 first, and the ranges begin at the same place, we go from just after
3679 the end of the first range to the end of the second. If the second
3680 range is not a subset of the first, or if it is a subset and both
3681 ranges end at the same place, the range starts at the start of the
3682 first range and ends just before the second range.
3683 Otherwise, we can't describe this as a single range. */
3685 in_p
= 1, low
= low0
, high
= high0
;
3686 else if (lowequal
&& highequal
)
3687 in_p
= 0, low
= high
= 0;
3688 else if (subset
&& lowequal
)
3690 in_p
= 1, high
= high0
;
3691 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high1
, 0,
3692 integer_one_node
, 0);
3694 else if (! subset
|| highequal
)
3696 in_p
= 1, low
= low0
;
3697 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low1
, 0,
3698 integer_one_node
, 0);
3704 else if (! in0_p
&& in1_p
)
3706 /* If they don't overlap, the result is the second range. If the second
3707 is a subset of the first, the result is false. Otherwise,
3708 the range starts just after the first range and ends at the
3709 end of the second. */
3711 in_p
= 1, low
= low1
, high
= high1
;
3712 else if (subset
|| highequal
)
3713 in_p
= 0, low
= high
= 0;
3716 in_p
= 1, high
= high1
;
3717 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high0
, 1,
3718 integer_one_node
, 0);
3724 /* The case where we are excluding both ranges. Here the complex case
3725 is if they don't overlap. In that case, the only time we have a
3726 range is if they are adjacent. If the second is a subset of the
3727 first, the result is the first. Otherwise, the range to exclude
3728 starts at the beginning of the first range and ends at the end of the
3732 if (integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3733 range_binop (PLUS_EXPR
, NULL_TREE
,
3735 integer_one_node
, 1),
3737 in_p
= 0, low
= low0
, high
= high1
;
3742 in_p
= 0, low
= low0
, high
= high0
;
3744 in_p
= 0, low
= low0
, high
= high1
;
3747 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
3751 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
3752 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
3755 /* EXP is some logical combination of boolean tests. See if we can
3756 merge it into some range test. Return the new tree if so. */
3759 fold_range_test (tree exp
)
3761 int or_op
= (TREE_CODE (exp
) == TRUTH_ORIF_EXPR
3762 || TREE_CODE (exp
) == TRUTH_OR_EXPR
);
3763 int in0_p
, in1_p
, in_p
;
3764 tree low0
, low1
, low
, high0
, high1
, high
;
3765 tree lhs
= make_range (TREE_OPERAND (exp
, 0), &in0_p
, &low0
, &high0
);
3766 tree rhs
= make_range (TREE_OPERAND (exp
, 1), &in1_p
, &low1
, &high1
);
3769 /* If this is an OR operation, invert both sides; we will invert
3770 again at the end. */
3772 in0_p
= ! in0_p
, in1_p
= ! in1_p
;
3774 /* If both expressions are the same, if we can merge the ranges, and we
3775 can build the range test, return it or it inverted. If one of the
3776 ranges is always true or always false, consider it to be the same
3777 expression as the other. */
3778 if ((lhs
== 0 || rhs
== 0 || operand_equal_p (lhs
, rhs
, 0))
3779 && merge_ranges (&in_p
, &low
, &high
, in0_p
, low0
, high0
,
3781 && 0 != (tem
= (build_range_check (TREE_TYPE (exp
),
3783 : rhs
!= 0 ? rhs
: integer_zero_node
,
3785 return or_op
? invert_truthvalue (tem
) : tem
;
3787 /* On machines where the branch cost is expensive, if this is a
3788 short-circuited branch and the underlying object on both sides
3789 is the same, make a non-short-circuit operation. */
3790 else if (RANGE_TEST_NON_SHORT_CIRCUIT
3791 && lhs
!= 0 && rhs
!= 0
3792 && (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3793 || TREE_CODE (exp
) == TRUTH_ORIF_EXPR
)
3794 && operand_equal_p (lhs
, rhs
, 0))
3796 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3797 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3798 which cases we can't do this. */
3799 if (simple_operand_p (lhs
))
3800 return build (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3801 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
3802 TREE_TYPE (exp
), TREE_OPERAND (exp
, 0),
3803 TREE_OPERAND (exp
, 1));
3805 else if ((*lang_hooks
.decls
.global_bindings_p
) () == 0
3806 && ! CONTAINS_PLACEHOLDER_P (lhs
))
3808 tree common
= save_expr (lhs
);
3810 if (0 != (lhs
= build_range_check (TREE_TYPE (exp
), common
,
3811 or_op
? ! in0_p
: in0_p
,
3813 && (0 != (rhs
= build_range_check (TREE_TYPE (exp
), common
,
3814 or_op
? ! in1_p
: in1_p
,
3816 return build (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3817 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
3818 TREE_TYPE (exp
), lhs
, rhs
);
3825 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3826 bit value. Arrange things so the extra bits will be set to zero if and
3827 only if C is signed-extended to its full width. If MASK is nonzero,
3828 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3831 unextend (tree c
, int p
, int unsignedp
, tree mask
)
3833 tree type
= TREE_TYPE (c
);
3834 int modesize
= GET_MODE_BITSIZE (TYPE_MODE (type
));
3837 if (p
== modesize
|| unsignedp
)
3840 /* We work by getting just the sign bit into the low-order bit, then
3841 into the high-order bit, then sign-extend. We then XOR that value
3843 temp
= const_binop (RSHIFT_EXPR
, c
, size_int (p
- 1), 0);
3844 temp
= const_binop (BIT_AND_EXPR
, temp
, size_int (1), 0);
3846 /* We must use a signed type in order to get an arithmetic right shift.
3847 However, we must also avoid introducing accidental overflows, so that
3848 a subsequent call to integer_zerop will work. Hence we must
3849 do the type conversion here. At this point, the constant is either
3850 zero or one, and the conversion to a signed type can never overflow.
3851 We could get an overflow if this conversion is done anywhere else. */
3852 if (TREE_UNSIGNED (type
))
3853 temp
= fold_convert ((*lang_hooks
.types
.signed_type
) (type
), temp
);
3855 temp
= const_binop (LSHIFT_EXPR
, temp
, size_int (modesize
- 1), 0);
3856 temp
= const_binop (RSHIFT_EXPR
, temp
, size_int (modesize
- p
- 1), 0);
3858 temp
= const_binop (BIT_AND_EXPR
, temp
,
3859 fold_convert (TREE_TYPE (c
), mask
), 0);
3860 /* If necessary, convert the type back to match the type of C. */
3861 if (TREE_UNSIGNED (type
))
3862 temp
= fold_convert (type
, temp
);
3864 return fold_convert (type
, const_binop (BIT_XOR_EXPR
, c
, temp
, 0));
3867 /* Find ways of folding logical expressions of LHS and RHS:
3868 Try to merge two comparisons to the same innermost item.
3869 Look for range tests like "ch >= '0' && ch <= '9'".
3870 Look for combinations of simple terms on machines with expensive branches
3871 and evaluate the RHS unconditionally.
3873 For example, if we have p->a == 2 && p->b == 4 and we can make an
3874 object large enough to span both A and B, we can do this with a comparison
3875 against the object ANDed with the a mask.
3877 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3878 operations to do this with one comparison.
3880 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3881 function and the one above.
3883 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3884 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3886 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3889 We return the simplified tree or 0 if no optimization is possible. */
3892 fold_truthop (enum tree_code code
, tree truth_type
, tree lhs
, tree rhs
)
3894 /* If this is the "or" of two comparisons, we can do something if
3895 the comparisons are NE_EXPR. If this is the "and", we can do something
3896 if the comparisons are EQ_EXPR. I.e.,
3897 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3899 WANTED_CODE is this operation code. For single bit fields, we can
3900 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3901 comparison for one-bit fields. */
3903 enum tree_code wanted_code
;
3904 enum tree_code lcode
, rcode
;
3905 tree ll_arg
, lr_arg
, rl_arg
, rr_arg
;
3906 tree ll_inner
, lr_inner
, rl_inner
, rr_inner
;
3907 HOST_WIDE_INT ll_bitsize
, ll_bitpos
, lr_bitsize
, lr_bitpos
;
3908 HOST_WIDE_INT rl_bitsize
, rl_bitpos
, rr_bitsize
, rr_bitpos
;
3909 HOST_WIDE_INT xll_bitpos
, xlr_bitpos
, xrl_bitpos
, xrr_bitpos
;
3910 HOST_WIDE_INT lnbitsize
, lnbitpos
, rnbitsize
, rnbitpos
;
3911 int ll_unsignedp
, lr_unsignedp
, rl_unsignedp
, rr_unsignedp
;
3912 enum machine_mode ll_mode
, lr_mode
, rl_mode
, rr_mode
;
3913 enum machine_mode lnmode
, rnmode
;
3914 tree ll_mask
, lr_mask
, rl_mask
, rr_mask
;
3915 tree ll_and_mask
, lr_and_mask
, rl_and_mask
, rr_and_mask
;
3916 tree l_const
, r_const
;
3917 tree lntype
, rntype
, result
;
3918 int first_bit
, end_bit
;
3921 /* Start by getting the comparison codes. Fail if anything is volatile.
3922 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3923 it were surrounded with a NE_EXPR. */
3925 if (TREE_SIDE_EFFECTS (lhs
) || TREE_SIDE_EFFECTS (rhs
))
3928 lcode
= TREE_CODE (lhs
);
3929 rcode
= TREE_CODE (rhs
);
3931 if (lcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (lhs
, 1)))
3932 lcode
= NE_EXPR
, lhs
= build (NE_EXPR
, truth_type
, lhs
, integer_zero_node
);
3934 if (rcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (rhs
, 1)))
3935 rcode
= NE_EXPR
, rhs
= build (NE_EXPR
, truth_type
, rhs
, integer_zero_node
);
3937 if (TREE_CODE_CLASS (lcode
) != '<' || TREE_CODE_CLASS (rcode
) != '<')
3940 code
= ((code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
)
3941 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
);
3943 ll_arg
= TREE_OPERAND (lhs
, 0);
3944 lr_arg
= TREE_OPERAND (lhs
, 1);
3945 rl_arg
= TREE_OPERAND (rhs
, 0);
3946 rr_arg
= TREE_OPERAND (rhs
, 1);
3948 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
3949 if (simple_operand_p (ll_arg
)
3950 && simple_operand_p (lr_arg
)
3951 && !FLOAT_TYPE_P (TREE_TYPE (ll_arg
)))
3955 if (operand_equal_p (ll_arg
, rl_arg
, 0)
3956 && operand_equal_p (lr_arg
, rr_arg
, 0))
3958 int lcompcode
, rcompcode
;
3960 lcompcode
= comparison_to_compcode (lcode
);
3961 rcompcode
= comparison_to_compcode (rcode
);
3962 compcode
= (code
== TRUTH_AND_EXPR
)
3963 ? lcompcode
& rcompcode
3964 : lcompcode
| rcompcode
;
3966 else if (operand_equal_p (ll_arg
, rr_arg
, 0)
3967 && operand_equal_p (lr_arg
, rl_arg
, 0))
3969 int lcompcode
, rcompcode
;
3971 rcode
= swap_tree_comparison (rcode
);
3972 lcompcode
= comparison_to_compcode (lcode
);
3973 rcompcode
= comparison_to_compcode (rcode
);
3974 compcode
= (code
== TRUTH_AND_EXPR
)
3975 ? lcompcode
& rcompcode
3976 : lcompcode
| rcompcode
;
3981 if (compcode
== COMPCODE_TRUE
)
3982 return fold_convert (truth_type
, integer_one_node
);
3983 else if (compcode
== COMPCODE_FALSE
)
3984 return fold_convert (truth_type
, integer_zero_node
);
3985 else if (compcode
!= -1)
3986 return build (compcode_to_comparison (compcode
),
3987 truth_type
, ll_arg
, lr_arg
);
3990 /* If the RHS can be evaluated unconditionally and its operands are
3991 simple, it wins to evaluate the RHS unconditionally on machines
3992 with expensive branches. In this case, this isn't a comparison
3993 that can be merged. Avoid doing this if the RHS is a floating-point
3994 comparison since those can trap. */
3996 if (BRANCH_COST
>= 2
3997 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg
))
3998 && simple_operand_p (rl_arg
)
3999 && simple_operand_p (rr_arg
))
4001 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
4002 if (code
== TRUTH_OR_EXPR
4003 && lcode
== NE_EXPR
&& integer_zerop (lr_arg
)
4004 && rcode
== NE_EXPR
&& integer_zerop (rr_arg
)
4005 && TREE_TYPE (ll_arg
) == TREE_TYPE (rl_arg
))
4006 return build (NE_EXPR
, truth_type
,
4007 build (BIT_IOR_EXPR
, TREE_TYPE (ll_arg
),
4011 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
4012 if (code
== TRUTH_AND_EXPR
4013 && lcode
== EQ_EXPR
&& integer_zerop (lr_arg
)
4014 && rcode
== EQ_EXPR
&& integer_zerop (rr_arg
)
4015 && TREE_TYPE (ll_arg
) == TREE_TYPE (rl_arg
))
4016 return build (EQ_EXPR
, truth_type
,
4017 build (BIT_IOR_EXPR
, TREE_TYPE (ll_arg
),
4021 return build (code
, truth_type
, lhs
, rhs
);
4024 /* See if the comparisons can be merged. Then get all the parameters for
4027 if ((lcode
!= EQ_EXPR
&& lcode
!= NE_EXPR
)
4028 || (rcode
!= EQ_EXPR
&& rcode
!= NE_EXPR
))
4032 ll_inner
= decode_field_reference (ll_arg
,
4033 &ll_bitsize
, &ll_bitpos
, &ll_mode
,
4034 &ll_unsignedp
, &volatilep
, &ll_mask
,
4036 lr_inner
= decode_field_reference (lr_arg
,
4037 &lr_bitsize
, &lr_bitpos
, &lr_mode
,
4038 &lr_unsignedp
, &volatilep
, &lr_mask
,
4040 rl_inner
= decode_field_reference (rl_arg
,
4041 &rl_bitsize
, &rl_bitpos
, &rl_mode
,
4042 &rl_unsignedp
, &volatilep
, &rl_mask
,
4044 rr_inner
= decode_field_reference (rr_arg
,
4045 &rr_bitsize
, &rr_bitpos
, &rr_mode
,
4046 &rr_unsignedp
, &volatilep
, &rr_mask
,
4049 /* It must be true that the inner operation on the lhs of each
4050 comparison must be the same if we are to be able to do anything.
4051 Then see if we have constants. If not, the same must be true for
4053 if (volatilep
|| ll_inner
== 0 || rl_inner
== 0
4054 || ! operand_equal_p (ll_inner
, rl_inner
, 0))
4057 if (TREE_CODE (lr_arg
) == INTEGER_CST
4058 && TREE_CODE (rr_arg
) == INTEGER_CST
)
4059 l_const
= lr_arg
, r_const
= rr_arg
;
4060 else if (lr_inner
== 0 || rr_inner
== 0
4061 || ! operand_equal_p (lr_inner
, rr_inner
, 0))
4064 l_const
= r_const
= 0;
4066 /* If either comparison code is not correct for our logical operation,
4067 fail. However, we can convert a one-bit comparison against zero into
4068 the opposite comparison against that bit being set in the field. */
4070 wanted_code
= (code
== TRUTH_AND_EXPR
? EQ_EXPR
: NE_EXPR
);
4071 if (lcode
!= wanted_code
)
4073 if (l_const
&& integer_zerop (l_const
) && integer_pow2p (ll_mask
))
4075 /* Make the left operand unsigned, since we are only interested
4076 in the value of one bit. Otherwise we are doing the wrong
4085 /* This is analogous to the code for l_const above. */
4086 if (rcode
!= wanted_code
)
4088 if (r_const
&& integer_zerop (r_const
) && integer_pow2p (rl_mask
))
4097 /* After this point all optimizations will generate bit-field
4098 references, which we might not want. */
4099 if (! (*lang_hooks
.can_use_bit_fields_p
) ())
4102 /* See if we can find a mode that contains both fields being compared on
4103 the left. If we can't, fail. Otherwise, update all constants and masks
4104 to be relative to a field of that size. */
4105 first_bit
= MIN (ll_bitpos
, rl_bitpos
);
4106 end_bit
= MAX (ll_bitpos
+ ll_bitsize
, rl_bitpos
+ rl_bitsize
);
4107 lnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
4108 TYPE_ALIGN (TREE_TYPE (ll_inner
)), word_mode
,
4110 if (lnmode
== VOIDmode
)
4113 lnbitsize
= GET_MODE_BITSIZE (lnmode
);
4114 lnbitpos
= first_bit
& ~ (lnbitsize
- 1);
4115 lntype
= (*lang_hooks
.types
.type_for_size
) (lnbitsize
, 1);
4116 xll_bitpos
= ll_bitpos
- lnbitpos
, xrl_bitpos
= rl_bitpos
- lnbitpos
;
4118 if (BYTES_BIG_ENDIAN
)
4120 xll_bitpos
= lnbitsize
- xll_bitpos
- ll_bitsize
;
4121 xrl_bitpos
= lnbitsize
- xrl_bitpos
- rl_bitsize
;
4124 ll_mask
= const_binop (LSHIFT_EXPR
, fold_convert (lntype
, ll_mask
),
4125 size_int (xll_bitpos
), 0);
4126 rl_mask
= const_binop (LSHIFT_EXPR
, fold_convert (lntype
, rl_mask
),
4127 size_int (xrl_bitpos
), 0);
4131 l_const
= fold_convert (lntype
, l_const
);
4132 l_const
= unextend (l_const
, ll_bitsize
, ll_unsignedp
, ll_and_mask
);
4133 l_const
= const_binop (LSHIFT_EXPR
, l_const
, size_int (xll_bitpos
), 0);
4134 if (! integer_zerop (const_binop (BIT_AND_EXPR
, l_const
,
4135 fold (build1 (BIT_NOT_EXPR
,
4139 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
4141 return fold_convert (truth_type
,
4142 wanted_code
== NE_EXPR
4143 ? integer_one_node
: integer_zero_node
);
4148 r_const
= fold_convert (lntype
, r_const
);
4149 r_const
= unextend (r_const
, rl_bitsize
, rl_unsignedp
, rl_and_mask
);
4150 r_const
= const_binop (LSHIFT_EXPR
, r_const
, size_int (xrl_bitpos
), 0);
4151 if (! integer_zerop (const_binop (BIT_AND_EXPR
, r_const
,
4152 fold (build1 (BIT_NOT_EXPR
,
4156 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
4158 return fold_convert (truth_type
,
4159 wanted_code
== NE_EXPR
4160 ? integer_one_node
: integer_zero_node
);
4164 /* If the right sides are not constant, do the same for it. Also,
4165 disallow this optimization if a size or signedness mismatch occurs
4166 between the left and right sides. */
4169 if (ll_bitsize
!= lr_bitsize
|| rl_bitsize
!= rr_bitsize
4170 || ll_unsignedp
!= lr_unsignedp
|| rl_unsignedp
!= rr_unsignedp
4171 /* Make sure the two fields on the right
4172 correspond to the left without being swapped. */
4173 || ll_bitpos
- rl_bitpos
!= lr_bitpos
- rr_bitpos
)
4176 first_bit
= MIN (lr_bitpos
, rr_bitpos
);
4177 end_bit
= MAX (lr_bitpos
+ lr_bitsize
, rr_bitpos
+ rr_bitsize
);
4178 rnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
4179 TYPE_ALIGN (TREE_TYPE (lr_inner
)), word_mode
,
4181 if (rnmode
== VOIDmode
)
4184 rnbitsize
= GET_MODE_BITSIZE (rnmode
);
4185 rnbitpos
= first_bit
& ~ (rnbitsize
- 1);
4186 rntype
= (*lang_hooks
.types
.type_for_size
) (rnbitsize
, 1);
4187 xlr_bitpos
= lr_bitpos
- rnbitpos
, xrr_bitpos
= rr_bitpos
- rnbitpos
;
4189 if (BYTES_BIG_ENDIAN
)
4191 xlr_bitpos
= rnbitsize
- xlr_bitpos
- lr_bitsize
;
4192 xrr_bitpos
= rnbitsize
- xrr_bitpos
- rr_bitsize
;
4195 lr_mask
= const_binop (LSHIFT_EXPR
, fold_convert (rntype
, lr_mask
),
4196 size_int (xlr_bitpos
), 0);
4197 rr_mask
= const_binop (LSHIFT_EXPR
, fold_convert (rntype
, rr_mask
),
4198 size_int (xrr_bitpos
), 0);
4200 /* Make a mask that corresponds to both fields being compared.
4201 Do this for both items being compared. If the operands are the
4202 same size and the bits being compared are in the same position
4203 then we can do this by masking both and comparing the masked
4205 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
4206 lr_mask
= const_binop (BIT_IOR_EXPR
, lr_mask
, rr_mask
, 0);
4207 if (lnbitsize
== rnbitsize
&& xll_bitpos
== xlr_bitpos
)
4209 lhs
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
4210 ll_unsignedp
|| rl_unsignedp
);
4211 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
4212 lhs
= build (BIT_AND_EXPR
, lntype
, lhs
, ll_mask
);
4214 rhs
= make_bit_field_ref (lr_inner
, rntype
, rnbitsize
, rnbitpos
,
4215 lr_unsignedp
|| rr_unsignedp
);
4216 if (! all_ones_mask_p (lr_mask
, rnbitsize
))
4217 rhs
= build (BIT_AND_EXPR
, rntype
, rhs
, lr_mask
);
4219 return build (wanted_code
, truth_type
, lhs
, rhs
);
4222 /* There is still another way we can do something: If both pairs of
4223 fields being compared are adjacent, we may be able to make a wider
4224 field containing them both.
4226 Note that we still must mask the lhs/rhs expressions. Furthermore,
4227 the mask must be shifted to account for the shift done by
4228 make_bit_field_ref. */
4229 if ((ll_bitsize
+ ll_bitpos
== rl_bitpos
4230 && lr_bitsize
+ lr_bitpos
== rr_bitpos
)
4231 || (ll_bitpos
== rl_bitpos
+ rl_bitsize
4232 && lr_bitpos
== rr_bitpos
+ rr_bitsize
))
4236 lhs
= make_bit_field_ref (ll_inner
, lntype
, ll_bitsize
+ rl_bitsize
,
4237 MIN (ll_bitpos
, rl_bitpos
), ll_unsignedp
);
4238 rhs
= make_bit_field_ref (lr_inner
, rntype
, lr_bitsize
+ rr_bitsize
,
4239 MIN (lr_bitpos
, rr_bitpos
), lr_unsignedp
);
4241 ll_mask
= const_binop (RSHIFT_EXPR
, ll_mask
,
4242 size_int (MIN (xll_bitpos
, xrl_bitpos
)), 0);
4243 lr_mask
= const_binop (RSHIFT_EXPR
, lr_mask
,
4244 size_int (MIN (xlr_bitpos
, xrr_bitpos
)), 0);
4246 /* Convert to the smaller type before masking out unwanted bits. */
4248 if (lntype
!= rntype
)
4250 if (lnbitsize
> rnbitsize
)
4252 lhs
= fold_convert (rntype
, lhs
);
4253 ll_mask
= fold_convert (rntype
, ll_mask
);
4256 else if (lnbitsize
< rnbitsize
)
4258 rhs
= fold_convert (lntype
, rhs
);
4259 lr_mask
= fold_convert (lntype
, lr_mask
);
4264 if (! all_ones_mask_p (ll_mask
, ll_bitsize
+ rl_bitsize
))
4265 lhs
= build (BIT_AND_EXPR
, type
, lhs
, ll_mask
);
4267 if (! all_ones_mask_p (lr_mask
, lr_bitsize
+ rr_bitsize
))
4268 rhs
= build (BIT_AND_EXPR
, type
, rhs
, lr_mask
);
4270 return build (wanted_code
, truth_type
, lhs
, rhs
);
4276 /* Handle the case of comparisons with constants. If there is something in
4277 common between the masks, those bits of the constants must be the same.
4278 If not, the condition is always false. Test for this to avoid generating
4279 incorrect code below. */
4280 result
= const_binop (BIT_AND_EXPR
, ll_mask
, rl_mask
, 0);
4281 if (! integer_zerop (result
)
4282 && simple_cst_equal (const_binop (BIT_AND_EXPR
, result
, l_const
, 0),
4283 const_binop (BIT_AND_EXPR
, result
, r_const
, 0)) != 1)
4285 if (wanted_code
== NE_EXPR
)
4287 warning ("`or' of unmatched not-equal tests is always 1");
4288 return fold_convert (truth_type
, integer_one_node
);
4292 warning ("`and' of mutually exclusive equal-tests is always 0");
4293 return fold_convert (truth_type
, integer_zero_node
);
4297 /* Construct the expression we will return. First get the component
4298 reference we will make. Unless the mask is all ones the width of
4299 that field, perform the mask operation. Then compare with the
4301 result
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
4302 ll_unsignedp
|| rl_unsignedp
);
4304 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
4305 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
4306 result
= build (BIT_AND_EXPR
, lntype
, result
, ll_mask
);
4308 return build (wanted_code
, truth_type
, result
,
4309 const_binop (BIT_IOR_EXPR
, l_const
, r_const
, 0));
4312 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4316 optimize_minmax_comparison (tree t
)
4318 tree type
= TREE_TYPE (t
);
4319 tree arg0
= TREE_OPERAND (t
, 0);
4320 enum tree_code op_code
;
4321 tree comp_const
= TREE_OPERAND (t
, 1);
4323 int consts_equal
, consts_lt
;
4326 STRIP_SIGN_NOPS (arg0
);
4328 op_code
= TREE_CODE (arg0
);
4329 minmax_const
= TREE_OPERAND (arg0
, 1);
4330 consts_equal
= tree_int_cst_equal (minmax_const
, comp_const
);
4331 consts_lt
= tree_int_cst_lt (minmax_const
, comp_const
);
4332 inner
= TREE_OPERAND (arg0
, 0);
4334 /* If something does not permit us to optimize, return the original tree. */
4335 if ((op_code
!= MIN_EXPR
&& op_code
!= MAX_EXPR
)
4336 || TREE_CODE (comp_const
) != INTEGER_CST
4337 || TREE_CONSTANT_OVERFLOW (comp_const
)
4338 || TREE_CODE (minmax_const
) != INTEGER_CST
4339 || TREE_CONSTANT_OVERFLOW (minmax_const
))
4342 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4343 and GT_EXPR, doing the rest with recursive calls using logical
4345 switch (TREE_CODE (t
))
4347 case NE_EXPR
: case LT_EXPR
: case LE_EXPR
:
4349 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t
)));
4353 fold (build (TRUTH_ORIF_EXPR
, type
,
4354 optimize_minmax_comparison
4355 (build (EQ_EXPR
, type
, arg0
, comp_const
)),
4356 optimize_minmax_comparison
4357 (build (GT_EXPR
, type
, arg0
, comp_const
))));
4360 if (op_code
== MAX_EXPR
&& consts_equal
)
4361 /* MAX (X, 0) == 0 -> X <= 0 */
4362 return fold (build (LE_EXPR
, type
, inner
, comp_const
));
4364 else if (op_code
== MAX_EXPR
&& consts_lt
)
4365 /* MAX (X, 0) == 5 -> X == 5 */
4366 return fold (build (EQ_EXPR
, type
, inner
, comp_const
));
4368 else if (op_code
== MAX_EXPR
)
4369 /* MAX (X, 0) == -1 -> false */
4370 return omit_one_operand (type
, integer_zero_node
, inner
);
4372 else if (consts_equal
)
4373 /* MIN (X, 0) == 0 -> X >= 0 */
4374 return fold (build (GE_EXPR
, type
, inner
, comp_const
));
4377 /* MIN (X, 0) == 5 -> false */
4378 return omit_one_operand (type
, integer_zero_node
, inner
);
4381 /* MIN (X, 0) == -1 -> X == -1 */
4382 return fold (build (EQ_EXPR
, type
, inner
, comp_const
));
4385 if (op_code
== MAX_EXPR
&& (consts_equal
|| consts_lt
))
4386 /* MAX (X, 0) > 0 -> X > 0
4387 MAX (X, 0) > 5 -> X > 5 */
4388 return fold (build (GT_EXPR
, type
, inner
, comp_const
));
4390 else if (op_code
== MAX_EXPR
)
4391 /* MAX (X, 0) > -1 -> true */
4392 return omit_one_operand (type
, integer_one_node
, inner
);
4394 else if (op_code
== MIN_EXPR
&& (consts_equal
|| consts_lt
))
4395 /* MIN (X, 0) > 0 -> false
4396 MIN (X, 0) > 5 -> false */
4397 return omit_one_operand (type
, integer_zero_node
, inner
);
4400 /* MIN (X, 0) > -1 -> X > -1 */
4401 return fold (build (GT_EXPR
, type
, inner
, comp_const
));
4408 /* T is an integer expression that is being multiplied, divided, or taken a
4409 modulus (CODE says which and what kind of divide or modulus) by a
4410 constant C. See if we can eliminate that operation by folding it with
4411 other operations already in T. WIDE_TYPE, if non-null, is a type that
4412 should be used for the computation if wider than our type.
4414 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4415 (X * 2) + (Y * 4). We must, however, be assured that either the original
4416 expression would not overflow or that overflow is undefined for the type
4417 in the language in question.
4419 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4420 the machine has a multiply-accumulate insn or that this is part of an
4421 addressing calculation.
4423 If we return a non-null expression, it is an equivalent form of the
4424 original computation, but need not be in the original type. */
4427 extract_muldiv (tree t
, tree c
, enum tree_code code
, tree wide_type
)
4429 /* To avoid exponential search depth, refuse to allow recursion past
4430 three levels. Beyond that (1) it's highly unlikely that we'll find
4431 something interesting and (2) we've probably processed it before
4432 when we built the inner expression. */
4441 ret
= extract_muldiv_1 (t
, c
, code
, wide_type
);
4448 extract_muldiv_1 (tree t
, tree c
, enum tree_code code
, tree wide_type
)
4450 tree type
= TREE_TYPE (t
);
4451 enum tree_code tcode
= TREE_CODE (t
);
4452 tree ctype
= (wide_type
!= 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type
))
4453 > GET_MODE_SIZE (TYPE_MODE (type
)))
4454 ? wide_type
: type
);
4456 int same_p
= tcode
== code
;
4457 tree op0
= NULL_TREE
, op1
= NULL_TREE
;
4459 /* Don't deal with constants of zero here; they confuse the code below. */
4460 if (integer_zerop (c
))
4463 if (TREE_CODE_CLASS (tcode
) == '1')
4464 op0
= TREE_OPERAND (t
, 0);
4466 if (TREE_CODE_CLASS (tcode
) == '2')
4467 op0
= TREE_OPERAND (t
, 0), op1
= TREE_OPERAND (t
, 1);
4469 /* Note that we need not handle conditional operations here since fold
4470 already handles those cases. So just do arithmetic here. */
4474 /* For a constant, we can always simplify if we are a multiply
4475 or (for divide and modulus) if it is a multiple of our constant. */
4476 if (code
== MULT_EXPR
4477 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, t
, c
, 0)))
4478 return const_binop (code
, fold_convert (ctype
, t
),
4479 fold_convert (ctype
, c
), 0);
4482 case CONVERT_EXPR
: case NON_LVALUE_EXPR
: case NOP_EXPR
:
4483 /* If op0 is an expression ... */
4484 if ((TREE_CODE_CLASS (TREE_CODE (op0
)) == '<'
4485 || TREE_CODE_CLASS (TREE_CODE (op0
)) == '1'
4486 || TREE_CODE_CLASS (TREE_CODE (op0
)) == '2'
4487 || TREE_CODE_CLASS (TREE_CODE (op0
)) == 'e')
4488 /* ... and is unsigned, and its type is smaller than ctype,
4489 then we cannot pass through as widening. */
4490 && ((TREE_UNSIGNED (TREE_TYPE (op0
))
4491 && ! (TREE_CODE (TREE_TYPE (op0
)) == INTEGER_TYPE
4492 && TYPE_IS_SIZETYPE (TREE_TYPE (op0
)))
4493 && (GET_MODE_SIZE (TYPE_MODE (ctype
))
4494 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
)))))
4495 /* ... or its type is larger than ctype,
4496 then we cannot pass through this truncation. */
4497 || (GET_MODE_SIZE (TYPE_MODE (ctype
))
4498 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
))))
4499 /* ... or signedness changes for division or modulus,
4500 then we cannot pass through this conversion. */
4501 || (code
!= MULT_EXPR
4502 && (TREE_UNSIGNED (ctype
)
4503 != TREE_UNSIGNED (TREE_TYPE (op0
))))))
4506 /* Pass the constant down and see if we can make a simplification. If
4507 we can, replace this expression with the inner simplification for
4508 possible later conversion to our or some other type. */
4509 if ((t2
= fold_convert (TREE_TYPE (op0
), c
)) != 0
4510 && TREE_CODE (t2
) == INTEGER_CST
4511 && ! TREE_CONSTANT_OVERFLOW (t2
)
4512 && (0 != (t1
= extract_muldiv (op0
, t2
, code
,
4514 ? ctype
: NULL_TREE
))))
4518 case NEGATE_EXPR
: case ABS_EXPR
:
4519 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
4520 return fold (build1 (tcode
, ctype
, fold_convert (ctype
, t1
)));
4523 case MIN_EXPR
: case MAX_EXPR
:
4524 /* If widening the type changes the signedness, then we can't perform
4525 this optimization as that changes the result. */
4526 if (TREE_UNSIGNED (ctype
) != TREE_UNSIGNED (type
))
4529 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4530 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0
4531 && (t2
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
4533 if (tree_int_cst_sgn (c
) < 0)
4534 tcode
= (tcode
== MIN_EXPR
? MAX_EXPR
: MIN_EXPR
);
4536 return fold (build (tcode
, ctype
, fold_convert (ctype
, t1
),
4537 fold_convert (ctype
, t2
)));
4541 case WITH_RECORD_EXPR
:
4542 if ((t1
= extract_muldiv (TREE_OPERAND (t
, 0), c
, code
, wide_type
)) != 0)
4543 return build (WITH_RECORD_EXPR
, TREE_TYPE (t1
), t1
,
4544 TREE_OPERAND (t
, 1));
4547 case LSHIFT_EXPR
: case RSHIFT_EXPR
:
4548 /* If the second operand is constant, this is a multiplication
4549 or floor division, by a power of two, so we can treat it that
4550 way unless the multiplier or divisor overflows. */
4551 if (TREE_CODE (op1
) == INTEGER_CST
4552 /* const_binop may not detect overflow correctly,
4553 so check for it explicitly here. */
4554 && TYPE_PRECISION (TREE_TYPE (size_one_node
)) > TREE_INT_CST_LOW (op1
)
4555 && TREE_INT_CST_HIGH (op1
) == 0
4556 && 0 != (t1
= fold_convert (ctype
,
4557 const_binop (LSHIFT_EXPR
,
4560 && ! TREE_OVERFLOW (t1
))
4561 return extract_muldiv (build (tcode
== LSHIFT_EXPR
4562 ? MULT_EXPR
: FLOOR_DIV_EXPR
,
4563 ctype
, fold_convert (ctype
, op0
), t1
),
4564 c
, code
, wide_type
);
4567 case PLUS_EXPR
: case MINUS_EXPR
:
4568 /* See if we can eliminate the operation on both sides. If we can, we
4569 can return a new PLUS or MINUS. If we can't, the only remaining
4570 cases where we can do anything are if the second operand is a
4572 t1
= extract_muldiv (op0
, c
, code
, wide_type
);
4573 t2
= extract_muldiv (op1
, c
, code
, wide_type
);
4574 if (t1
!= 0 && t2
!= 0
4575 && (code
== MULT_EXPR
4576 /* If not multiplication, we can only do this if both operands
4577 are divisible by c. */
4578 || (multiple_of_p (ctype
, op0
, c
)
4579 && multiple_of_p (ctype
, op1
, c
))))
4580 return fold (build (tcode
, ctype
, fold_convert (ctype
, t1
),
4581 fold_convert (ctype
, t2
)));
4583 /* If this was a subtraction, negate OP1 and set it to be an addition.
4584 This simplifies the logic below. */
4585 if (tcode
== MINUS_EXPR
)
4586 tcode
= PLUS_EXPR
, op1
= negate_expr (op1
);
4588 if (TREE_CODE (op1
) != INTEGER_CST
)
4591 /* If either OP1 or C are negative, this optimization is not safe for
4592 some of the division and remainder types while for others we need
4593 to change the code. */
4594 if (tree_int_cst_sgn (op1
) < 0 || tree_int_cst_sgn (c
) < 0)
4596 if (code
== CEIL_DIV_EXPR
)
4597 code
= FLOOR_DIV_EXPR
;
4598 else if (code
== FLOOR_DIV_EXPR
)
4599 code
= CEIL_DIV_EXPR
;
4600 else if (code
!= MULT_EXPR
4601 && code
!= CEIL_MOD_EXPR
&& code
!= FLOOR_MOD_EXPR
)
4605 /* If it's a multiply or a division/modulus operation of a multiple
4606 of our constant, do the operation and verify it doesn't overflow. */
4607 if (code
== MULT_EXPR
4608 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4610 op1
= const_binop (code
, fold_convert (ctype
, op1
),
4611 fold_convert (ctype
, c
), 0);
4612 /* We allow the constant to overflow with wrapping semantics. */
4614 || (TREE_OVERFLOW (op1
) && ! flag_wrapv
))
4620 /* If we have an unsigned type is not a sizetype, we cannot widen
4621 the operation since it will change the result if the original
4622 computation overflowed. */
4623 if (TREE_UNSIGNED (ctype
)
4624 && ! (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
))
4628 /* If we were able to eliminate our operation from the first side,
4629 apply our operation to the second side and reform the PLUS. */
4630 if (t1
!= 0 && (TREE_CODE (t1
) != code
|| code
== MULT_EXPR
))
4631 return fold (build (tcode
, ctype
, fold_convert (ctype
, t1
), op1
));
4633 /* The last case is if we are a multiply. In that case, we can
4634 apply the distributive law to commute the multiply and addition
4635 if the multiplication of the constants doesn't overflow. */
4636 if (code
== MULT_EXPR
)
4637 return fold (build (tcode
, ctype
,
4638 fold (build (code
, ctype
,
4639 fold_convert (ctype
, op0
),
4640 fold_convert (ctype
, c
))),
4646 /* We have a special case here if we are doing something like
4647 (C * 8) % 4 since we know that's zero. */
4648 if ((code
== TRUNC_MOD_EXPR
|| code
== CEIL_MOD_EXPR
4649 || code
== FLOOR_MOD_EXPR
|| code
== ROUND_MOD_EXPR
)
4650 && TREE_CODE (TREE_OPERAND (t
, 1)) == INTEGER_CST
4651 && integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4652 return omit_one_operand (type
, integer_zero_node
, op0
);
4654 /* ... fall through ... */
4656 case TRUNC_DIV_EXPR
: case CEIL_DIV_EXPR
: case FLOOR_DIV_EXPR
:
4657 case ROUND_DIV_EXPR
: case EXACT_DIV_EXPR
:
4658 /* If we can extract our operation from the LHS, do so and return a
4659 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4660 do something only if the second operand is a constant. */
4662 && (t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
4663 return fold (build (tcode
, ctype
, fold_convert (ctype
, t1
),
4664 fold_convert (ctype
, op1
)));
4665 else if (tcode
== MULT_EXPR
&& code
== MULT_EXPR
4666 && (t1
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
4667 return fold (build (tcode
, ctype
, fold_convert (ctype
, op0
),
4668 fold_convert (ctype
, t1
)));
4669 else if (TREE_CODE (op1
) != INTEGER_CST
)
4672 /* If these are the same operation types, we can associate them
4673 assuming no overflow. */
4675 && 0 != (t1
= const_binop (MULT_EXPR
, fold_convert (ctype
, op1
),
4676 fold_convert (ctype
, c
), 0))
4677 && ! TREE_OVERFLOW (t1
))
4678 return fold (build (tcode
, ctype
, fold_convert (ctype
, op0
), t1
));
4680 /* If these operations "cancel" each other, we have the main
4681 optimizations of this pass, which occur when either constant is a
4682 multiple of the other, in which case we replace this with either an
4683 operation or CODE or TCODE.
4685 If we have an unsigned type that is not a sizetype, we cannot do
4686 this since it will change the result if the original computation
4688 if ((! TREE_UNSIGNED (ctype
)
4689 || (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
)))
4691 && ((code
== MULT_EXPR
&& tcode
== EXACT_DIV_EXPR
)
4692 || (tcode
== MULT_EXPR
4693 && code
!= TRUNC_MOD_EXPR
&& code
!= CEIL_MOD_EXPR
4694 && code
!= FLOOR_MOD_EXPR
&& code
!= ROUND_MOD_EXPR
)))
4696 if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4697 return fold (build (tcode
, ctype
, fold_convert (ctype
, op0
),
4698 fold_convert (ctype
,
4699 const_binop (TRUNC_DIV_EXPR
,
4701 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, c
, op1
, 0)))
4702 return fold (build (code
, ctype
, fold_convert (ctype
, op0
),
4703 fold_convert (ctype
,
4704 const_binop (TRUNC_DIV_EXPR
,
4716 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4717 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4718 that we may sometimes modify the tree. */
4721 strip_compound_expr (tree t
, tree s
)
4723 enum tree_code code
= TREE_CODE (t
);
4725 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4726 if (code
== COMPOUND_EXPR
&& TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
4727 && TREE_OPERAND (TREE_OPERAND (t
, 0), 0) == s
)
4728 return TREE_OPERAND (t
, 1);
4730 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4731 don't bother handling any other types. */
4732 else if (code
== COND_EXPR
)
4734 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4735 TREE_OPERAND (t
, 1) = strip_compound_expr (TREE_OPERAND (t
, 1), s
);
4736 TREE_OPERAND (t
, 2) = strip_compound_expr (TREE_OPERAND (t
, 2), s
);
4738 else if (TREE_CODE_CLASS (code
) == '1')
4739 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4740 else if (TREE_CODE_CLASS (code
) == '<'
4741 || TREE_CODE_CLASS (code
) == '2')
4743 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4744 TREE_OPERAND (t
, 1) = strip_compound_expr (TREE_OPERAND (t
, 1), s
);
4750 /* Return a node which has the indicated constant VALUE (either 0 or
4751 1), and is of the indicated TYPE. */
4754 constant_boolean_node (int value
, tree type
)
4756 if (type
== integer_type_node
)
4757 return value
? integer_one_node
: integer_zero_node
;
4758 else if (TREE_CODE (type
) == BOOLEAN_TYPE
)
4759 return (*lang_hooks
.truthvalue_conversion
) (value
? integer_one_node
:
4763 tree t
= build_int_2 (value
, 0);
4765 TREE_TYPE (t
) = type
;
4770 /* Utility function for the following routine, to see how complex a nesting of
4771 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4772 we don't care (to avoid spending too much time on complex expressions.). */
4775 count_cond (tree expr
, int lim
)
4779 if (TREE_CODE (expr
) != COND_EXPR
)
4784 ctrue
= count_cond (TREE_OPERAND (expr
, 1), lim
- 1);
4785 cfalse
= count_cond (TREE_OPERAND (expr
, 2), lim
- 1 - ctrue
);
4786 return MIN (lim
, 1 + ctrue
+ cfalse
);
4789 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
4790 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4791 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4792 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
4793 COND is the first argument to CODE; otherwise (as in the example
4794 given here), it is the second argument. TYPE is the type of the
4795 original expression. */
4798 fold_binary_op_with_conditional_arg (enum tree_code code
, tree type
,
4799 tree cond
, tree arg
, int cond_first_p
)
4801 tree test
, true_value
, false_value
;
4802 tree lhs
= NULL_TREE
;
4803 tree rhs
= NULL_TREE
;
4804 /* In the end, we'll produce a COND_EXPR. Both arms of the
4805 conditional expression will be binary operations. The left-hand
4806 side of the expression to be executed if the condition is true
4807 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4808 of the expression to be executed if the condition is true will be
4809 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4810 but apply to the expression to be executed if the conditional is
4816 /* These are the codes to use for the left-hand side and right-hand
4817 side of the COND_EXPR. Normally, they are the same as CODE. */
4818 enum tree_code lhs_code
= code
;
4819 enum tree_code rhs_code
= code
;
4820 /* And these are the types of the expressions. */
4821 tree lhs_type
= type
;
4822 tree rhs_type
= type
;
4827 true_rhs
= false_rhs
= &arg
;
4828 true_lhs
= &true_value
;
4829 false_lhs
= &false_value
;
4833 true_lhs
= false_lhs
= &arg
;
4834 true_rhs
= &true_value
;
4835 false_rhs
= &false_value
;
4838 if (TREE_CODE (cond
) == COND_EXPR
)
4840 test
= TREE_OPERAND (cond
, 0);
4841 true_value
= TREE_OPERAND (cond
, 1);
4842 false_value
= TREE_OPERAND (cond
, 2);
4843 /* If this operand throws an expression, then it does not make
4844 sense to try to perform a logical or arithmetic operation
4845 involving it. Instead of building `a + throw 3' for example,
4846 we simply build `a, throw 3'. */
4847 if (VOID_TYPE_P (TREE_TYPE (true_value
)))
4851 lhs_code
= COMPOUND_EXPR
;
4852 lhs_type
= void_type_node
;
4857 if (VOID_TYPE_P (TREE_TYPE (false_value
)))
4861 rhs_code
= COMPOUND_EXPR
;
4862 rhs_type
= void_type_node
;
4870 tree testtype
= TREE_TYPE (cond
);
4872 true_value
= fold_convert (testtype
, integer_one_node
);
4873 false_value
= fold_convert (testtype
, integer_zero_node
);
4876 /* If ARG is complex we want to make sure we only evaluate it once. Though
4877 this is only required if it is volatile, it might be more efficient even
4878 if it is not. However, if we succeed in folding one part to a constant,
4879 we do not need to make this SAVE_EXPR. Since we do this optimization
4880 primarily to see if we do end up with constant and this SAVE_EXPR
4881 interferes with later optimizations, suppressing it when we can is
4884 If we are not in a function, we can't make a SAVE_EXPR, so don't try to
4885 do so. Don't try to see if the result is a constant if an arm is a
4886 COND_EXPR since we get exponential behavior in that case. */
4888 if (saved_expr_p (arg
))
4890 else if (lhs
== 0 && rhs
== 0
4891 && !TREE_CONSTANT (arg
)
4892 && (*lang_hooks
.decls
.global_bindings_p
) () == 0
4893 && ((TREE_CODE (arg
) != VAR_DECL
&& TREE_CODE (arg
) != PARM_DECL
)
4894 || TREE_SIDE_EFFECTS (arg
)))
4896 if (TREE_CODE (true_value
) != COND_EXPR
)
4897 lhs
= fold (build (lhs_code
, lhs_type
, *true_lhs
, *true_rhs
));
4899 if (TREE_CODE (false_value
) != COND_EXPR
)
4900 rhs
= fold (build (rhs_code
, rhs_type
, *false_lhs
, *false_rhs
));
4902 if ((lhs
== 0 || ! TREE_CONSTANT (lhs
))
4903 && (rhs
== 0 || !TREE_CONSTANT (rhs
)))
4905 arg
= save_expr (arg
);
4907 save
= saved_expr_p (arg
);
4912 lhs
= fold (build (lhs_code
, lhs_type
, *true_lhs
, *true_rhs
));
4914 rhs
= fold (build (rhs_code
, rhs_type
, *false_lhs
, *false_rhs
));
4916 test
= fold (build (COND_EXPR
, type
, test
, lhs
, rhs
));
4918 /* If ARG involves a SAVE_EXPR, we need to ensure it is evaluated
4919 ahead of the COND_EXPR we made. Otherwise we would have it only
4920 evaluated in one branch, with the other branch using the result
4921 but missing the evaluation code. Beware that the save_expr call
4922 above might not return a SAVE_EXPR, so testing the TREE_CODE
4923 of ARG is not enough to decide here. Â */
4925 return build (COMPOUND_EXPR
, type
,
4926 fold_convert (void_type_node
, arg
),
4927 strip_compound_expr (test
, arg
));
4929 return fold_convert (type
, test
);
4933 /* Subroutine of fold() that checks for the addition of +/- 0.0.
4935 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
4936 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
4937 ADDEND is the same as X.
4939 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
4940 and finite. The problematic cases are when X is zero, and its mode
4941 has signed zeros. In the case of rounding towards -infinity,
4942 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
4943 modes, X + 0 is not the same as X because -0 + 0 is 0. */
4946 fold_real_zero_addition_p (tree type
, tree addend
, int negate
)
4948 if (!real_zerop (addend
))
4951 /* Don't allow the fold with -fsignaling-nans. */
4952 if (HONOR_SNANS (TYPE_MODE (type
)))
4955 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
4956 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type
)))
4959 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
4960 if (TREE_CODE (addend
) == REAL_CST
4961 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend
)))
4964 /* The mode has signed zeros, and we have to honor their sign.
4965 In this situation, there is only one case we can return true for.
4966 X - 0 is the same as X unless rounding towards -infinity is
4968 return negate
&& !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type
));
4971 /* Subroutine of fold() that checks comparisons of built-in math
4972 functions against real constants.
4974 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
4975 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
4976 is the type of the result and ARG0 and ARG1 are the operands of the
4977 comparison. ARG1 must be a TREE_REAL_CST.
4979 The function returns the constant folded tree if a simplification
4980 can be made, and NULL_TREE otherwise. */
4983 fold_mathfn_compare (enum built_in_function fcode
, enum tree_code code
,
4984 tree type
, tree arg0
, tree arg1
)
4988 if (fcode
== BUILT_IN_SQRT
4989 || fcode
== BUILT_IN_SQRTF
4990 || fcode
== BUILT_IN_SQRTL
)
4992 tree arg
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
4993 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (arg0
));
4995 c
= TREE_REAL_CST (arg1
);
4996 if (REAL_VALUE_NEGATIVE (c
))
4998 /* sqrt(x) < y is always false, if y is negative. */
4999 if (code
== EQ_EXPR
|| code
== LT_EXPR
|| code
== LE_EXPR
)
5000 return omit_one_operand (type
,
5001 fold_convert (type
, integer_zero_node
),
5004 /* sqrt(x) > y is always true, if y is negative and we
5005 don't care about NaNs, i.e. negative values of x. */
5006 if (code
== NE_EXPR
|| !HONOR_NANS (mode
))
5007 return omit_one_operand (type
,
5008 fold_convert (type
, integer_one_node
),
5011 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
5012 return fold (build (GE_EXPR
, type
, arg
,
5013 build_real (TREE_TYPE (arg
), dconst0
)));
5015 else if (code
== GT_EXPR
|| code
== GE_EXPR
)
5019 REAL_ARITHMETIC (c2
, MULT_EXPR
, c
, c
);
5020 real_convert (&c2
, mode
, &c2
);
5022 if (REAL_VALUE_ISINF (c2
))
5024 /* sqrt(x) > y is x == +Inf, when y is very large. */
5025 if (HONOR_INFINITIES (mode
))
5026 return fold (build (EQ_EXPR
, type
, arg
,
5027 build_real (TREE_TYPE (arg
), c2
)));
5029 /* sqrt(x) > y is always false, when y is very large
5030 and we don't care about infinities. */
5031 return omit_one_operand (type
,
5032 fold_convert (type
, integer_zero_node
),
5036 /* sqrt(x) > c is the same as x > c*c. */
5037 return fold (build (code
, type
, arg
,
5038 build_real (TREE_TYPE (arg
), c2
)));
5040 else if (code
== LT_EXPR
|| code
== LE_EXPR
)
5044 REAL_ARITHMETIC (c2
, MULT_EXPR
, c
, c
);
5045 real_convert (&c2
, mode
, &c2
);
5047 if (REAL_VALUE_ISINF (c2
))
5049 /* sqrt(x) < y is always true, when y is a very large
5050 value and we don't care about NaNs or Infinities. */
5051 if (! HONOR_NANS (mode
) && ! HONOR_INFINITIES (mode
))
5052 return omit_one_operand (type
,
5053 fold_convert (type
, integer_one_node
),
5056 /* sqrt(x) < y is x != +Inf when y is very large and we
5057 don't care about NaNs. */
5058 if (! HONOR_NANS (mode
))
5059 return fold (build (NE_EXPR
, type
, arg
,
5060 build_real (TREE_TYPE (arg
), c2
)));
5062 /* sqrt(x) < y is x >= 0 when y is very large and we
5063 don't care about Infinities. */
5064 if (! HONOR_INFINITIES (mode
))
5065 return fold (build (GE_EXPR
, type
, arg
,
5066 build_real (TREE_TYPE (arg
), dconst0
)));
5068 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
5069 if ((*lang_hooks
.decls
.global_bindings_p
) () != 0
5070 || CONTAINS_PLACEHOLDER_P (arg
))
5073 arg
= save_expr (arg
);
5074 return fold (build (TRUTH_ANDIF_EXPR
, type
,
5075 fold (build (GE_EXPR
, type
, arg
,
5076 build_real (TREE_TYPE (arg
),
5078 fold (build (NE_EXPR
, type
, arg
,
5079 build_real (TREE_TYPE (arg
),
5083 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
5084 if (! HONOR_NANS (mode
))
5085 return fold (build (code
, type
, arg
,
5086 build_real (TREE_TYPE (arg
), c2
)));
5088 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
5089 if ((*lang_hooks
.decls
.global_bindings_p
) () == 0
5090 && ! CONTAINS_PLACEHOLDER_P (arg
))
5092 arg
= save_expr (arg
);
5093 return fold (build (TRUTH_ANDIF_EXPR
, type
,
5094 fold (build (GE_EXPR
, type
, arg
,
5095 build_real (TREE_TYPE (arg
),
5097 fold (build (code
, type
, arg
,
5098 build_real (TREE_TYPE (arg
),
5107 /* Subroutine of fold() that optimizes comparisons against Infinities,
5108 either +Inf or -Inf.
5110 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5111 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5112 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5114 The function returns the constant folded tree if a simplification
5115 can be made, and NULL_TREE otherwise. */
5118 fold_inf_compare (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
5120 enum machine_mode mode
;
5121 REAL_VALUE_TYPE max
;
5125 mode
= TYPE_MODE (TREE_TYPE (arg0
));
5127 /* For negative infinity swap the sense of the comparison. */
5128 neg
= REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1
));
5130 code
= swap_tree_comparison (code
);
5135 /* x > +Inf is always false, if with ignore sNANs. */
5136 if (HONOR_SNANS (mode
))
5138 return omit_one_operand (type
,
5139 fold_convert (type
, integer_zero_node
),
5143 /* x <= +Inf is always true, if we don't case about NaNs. */
5144 if (! HONOR_NANS (mode
))
5145 return omit_one_operand (type
,
5146 fold_convert (type
, integer_one_node
),
5149 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
5150 if ((*lang_hooks
.decls
.global_bindings_p
) () == 0
5151 && ! CONTAINS_PLACEHOLDER_P (arg0
))
5153 arg0
= save_expr (arg0
);
5154 return fold (build (EQ_EXPR
, type
, arg0
, arg0
));
5160 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
5161 real_maxval (&max
, neg
, mode
);
5162 return fold (build (neg
? LT_EXPR
: GT_EXPR
, type
,
5163 arg0
, build_real (TREE_TYPE (arg0
), max
)));
5166 /* x < +Inf is always equal to x <= DBL_MAX. */
5167 real_maxval (&max
, neg
, mode
);
5168 return fold (build (neg
? GE_EXPR
: LE_EXPR
, type
,
5169 arg0
, build_real (TREE_TYPE (arg0
), max
)));
5172 /* x != +Inf is always equal to !(x > DBL_MAX). */
5173 real_maxval (&max
, neg
, mode
);
5174 if (! HONOR_NANS (mode
))
5175 return fold (build (neg
? GE_EXPR
: LE_EXPR
, type
,
5176 arg0
, build_real (TREE_TYPE (arg0
), max
)));
5177 temp
= fold (build (neg
? LT_EXPR
: GT_EXPR
, type
,
5178 arg0
, build_real (TREE_TYPE (arg0
), max
)));
5179 return fold (build1 (TRUTH_NOT_EXPR
, type
, temp
));
5188 /* If CODE with arguments ARG0 and ARG1 represents a single bit
5189 equality/inequality test, then return a simplified form of
5190 the test using shifts and logical operations. Otherwise return
5191 NULL. TYPE is the desired result type. */
5194 fold_single_bit_test (enum tree_code code
, tree arg0
, tree arg1
,
5197 /* If this is a TRUTH_NOT_EXPR, it may have a single bit test inside
5199 if (code
== TRUTH_NOT_EXPR
)
5201 code
= TREE_CODE (arg0
);
5202 if (code
!= NE_EXPR
&& code
!= EQ_EXPR
)
5205 /* Extract the arguments of the EQ/NE. */
5206 arg1
= TREE_OPERAND (arg0
, 1);
5207 arg0
= TREE_OPERAND (arg0
, 0);
5209 /* This requires us to invert the code. */
5210 code
= (code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
);
5213 /* If this is testing a single bit, we can optimize the test. */
5214 if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
5215 && TREE_CODE (arg0
) == BIT_AND_EXPR
&& integer_zerop (arg1
)
5216 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
5218 tree inner
= TREE_OPERAND (arg0
, 0);
5219 tree type
= TREE_TYPE (arg0
);
5220 int bitnum
= tree_log2 (TREE_OPERAND (arg0
, 1));
5221 enum machine_mode operand_mode
= TYPE_MODE (type
);
5223 tree signed_type
, unsigned_type
, intermediate_type
;
5226 /* If we have (A & C) != 0 where C is the sign bit of A, convert
5227 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
5228 arg00
= sign_bit_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg0
, 1));
5229 if (arg00
!= NULL_TREE
)
5231 tree stype
= (*lang_hooks
.types
.signed_type
) (TREE_TYPE (arg00
));
5232 return fold (build (code
== EQ_EXPR
? GE_EXPR
: LT_EXPR
, result_type
,
5233 fold_convert (stype
, arg00
),
5234 fold_convert (stype
, integer_zero_node
)));
5237 /* At this point, we know that arg0 is not testing the sign bit. */
5238 if (TYPE_PRECISION (type
) - 1 == bitnum
)
5241 /* Otherwise we have (A & C) != 0 where C is a single bit,
5242 convert that into ((A >> C2) & 1). Where C2 = log2(C).
5243 Similarly for (A & C) == 0. */
5245 /* If INNER is a right shift of a constant and it plus BITNUM does
5246 not overflow, adjust BITNUM and INNER. */
5247 if (TREE_CODE (inner
) == RSHIFT_EXPR
5248 && TREE_CODE (TREE_OPERAND (inner
, 1)) == INTEGER_CST
5249 && TREE_INT_CST_HIGH (TREE_OPERAND (inner
, 1)) == 0
5250 && bitnum
< TYPE_PRECISION (type
)
5251 && 0 > compare_tree_int (TREE_OPERAND (inner
, 1),
5252 bitnum
- TYPE_PRECISION (type
)))
5254 bitnum
+= TREE_INT_CST_LOW (TREE_OPERAND (inner
, 1));
5255 inner
= TREE_OPERAND (inner
, 0);
5258 /* If we are going to be able to omit the AND below, we must do our
5259 operations as unsigned. If we must use the AND, we have a choice.
5260 Normally unsigned is faster, but for some machines signed is. */
5261 #ifdef LOAD_EXTEND_OP
5262 ops_unsigned
= (LOAD_EXTEND_OP (operand_mode
) == SIGN_EXTEND
? 0 : 1);
5267 signed_type
= (*lang_hooks
.types
.type_for_mode
) (operand_mode
, 0);
5268 unsigned_type
= (*lang_hooks
.types
.type_for_mode
) (operand_mode
, 1);
5269 intermediate_type
= ops_unsigned
? unsigned_type
: signed_type
;
5270 inner
= fold_convert (intermediate_type
, inner
);
5273 inner
= build (RSHIFT_EXPR
, intermediate_type
,
5274 inner
, size_int (bitnum
));
5276 if (code
== EQ_EXPR
)
5277 inner
= build (BIT_XOR_EXPR
, intermediate_type
,
5278 inner
, integer_one_node
);
5280 /* Put the AND last so it can combine with more things. */
5281 inner
= build (BIT_AND_EXPR
, intermediate_type
,
5282 inner
, integer_one_node
);
5284 /* Make sure to return the proper type. */
5285 inner
= fold_convert (result_type
, inner
);
5292 /* Check whether we are allowed to reorder operands arg0 and arg1,
5293 such that the evaluation of arg1 occurs before arg0. */
5296 reorder_operands_p (tree arg0
, tree arg1
)
5298 if (! flag_evaluation_order
)
5300 if (TREE_CONSTANT (arg0
) || TREE_CONSTANT (arg1
))
5302 return ! TREE_SIDE_EFFECTS (arg0
)
5303 && ! TREE_SIDE_EFFECTS (arg1
);
5306 /* Test whether it is preferable two swap two operands, ARG0 and
5307 ARG1, for example because ARG0 is an integer constant and ARG1
5308 isn't. If REORDER is true, only recommend swapping if we can
5309 evaluate the operands in reverse order. */
5312 tree_swap_operands_p (tree arg0
, tree arg1
, bool reorder
)
5314 STRIP_SIGN_NOPS (arg0
);
5315 STRIP_SIGN_NOPS (arg1
);
5317 if (TREE_CODE (arg1
) == INTEGER_CST
)
5319 if (TREE_CODE (arg0
) == INTEGER_CST
)
5322 if (TREE_CODE (arg1
) == REAL_CST
)
5324 if (TREE_CODE (arg0
) == REAL_CST
)
5327 if (TREE_CODE (arg1
) == COMPLEX_CST
)
5329 if (TREE_CODE (arg0
) == COMPLEX_CST
)
5332 if (TREE_CONSTANT (arg1
))
5334 if (TREE_CONSTANT (arg0
))
5340 if (reorder
&& flag_evaluation_order
5341 && (TREE_SIDE_EFFECTS (arg0
) || TREE_SIDE_EFFECTS (arg1
)))
5352 /* Perform constant folding and related simplification of EXPR.
5353 The related simplifications include x*1 => x, x*0 => 0, etc.,
5354 and application of the associative law.
5355 NOP_EXPR conversions may be removed freely (as long as we
5356 are careful not to change the C type of the overall expression)
5357 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
5358 but we can constant-fold them if they have constant operands. */
5360 #ifdef ENABLE_FOLD_CHECKING
5361 # define fold(x) fold_1 (x)
5362 static tree
fold_1 (tree
);
5368 tree t
= expr
, orig_t
;
5369 tree t1
= NULL_TREE
;
5371 tree type
= TREE_TYPE (expr
);
5372 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
;
5373 enum tree_code code
= TREE_CODE (t
);
5374 int kind
= TREE_CODE_CLASS (code
);
5376 /* WINS will be nonzero when the switch is done
5377 if all operands are constant. */
5380 /* Don't try to process an RTL_EXPR since its operands aren't trees.
5381 Likewise for a SAVE_EXPR that's already been evaluated. */
5382 if (code
== RTL_EXPR
|| (code
== SAVE_EXPR
&& SAVE_EXPR_RTL (t
) != 0))
5385 /* Return right away if a constant. */
5391 if (code
== NOP_EXPR
|| code
== FLOAT_EXPR
|| code
== CONVERT_EXPR
)
5395 /* Special case for conversion ops that can have fixed point args. */
5396 arg0
= TREE_OPERAND (t
, 0);
5398 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
5400 STRIP_SIGN_NOPS (arg0
);
5402 if (arg0
!= 0 && TREE_CODE (arg0
) == COMPLEX_CST
)
5403 subop
= TREE_REALPART (arg0
);
5407 if (subop
!= 0 && TREE_CODE (subop
) != INTEGER_CST
5408 && TREE_CODE (subop
) != REAL_CST
)
5409 /* Note that TREE_CONSTANT isn't enough:
5410 static var addresses are constant but we can't
5411 do arithmetic on them. */
5414 else if (IS_EXPR_CODE_CLASS (kind
))
5416 int len
= first_rtl_op (code
);
5418 for (i
= 0; i
< len
; i
++)
5420 tree op
= TREE_OPERAND (t
, i
);
5424 continue; /* Valid for CALL_EXPR, at least. */
5426 /* Strip any conversions that don't change the mode. This is
5427 safe for every expression, except for a comparison expression
5428 because its signedness is derived from its operands. So, in
5429 the latter case, only strip conversions that don't change the
5432 Note that this is done as an internal manipulation within the
5433 constant folder, in order to find the simplest representation
5434 of the arguments so that their form can be studied. In any
5435 cases, the appropriate type conversions should be put back in
5436 the tree that will get out of the constant folder. */
5438 STRIP_SIGN_NOPS (op
);
5442 if (TREE_CODE (op
) == COMPLEX_CST
)
5443 subop
= TREE_REALPART (op
);
5447 if (TREE_CODE (subop
) != INTEGER_CST
5448 && TREE_CODE (subop
) != REAL_CST
)
5449 /* Note that TREE_CONSTANT isn't enough:
5450 static var addresses are constant but we can't
5451 do arithmetic on them. */
5461 /* If this is a commutative operation, and ARG0 is a constant, move it
5462 to ARG1 to reduce the number of tests below. */
5463 if (commutative_tree_code (code
)
5464 && tree_swap_operands_p (arg0
, arg1
, true))
5465 return fold (build (code
, type
, TREE_OPERAND (t
, 1),
5466 TREE_OPERAND (t
, 0)));
5468 /* Now WINS is set as described above,
5469 ARG0 is the first operand of EXPR,
5470 and ARG1 is the second operand (if it has more than one operand).
5472 First check for cases where an arithmetic operation is applied to a
5473 compound, conditional, or comparison operation. Push the arithmetic
5474 operation inside the compound or conditional to see if any folding
5475 can then be done. Convert comparison to conditional for this purpose.
5476 The also optimizes non-constant cases that used to be done in
5479 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
5480 one of the operands is a comparison and the other is a comparison, a
5481 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
5482 code below would make the expression more complex. Change it to a
5483 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
5484 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
5486 if ((code
== BIT_AND_EXPR
|| code
== BIT_IOR_EXPR
5487 || code
== EQ_EXPR
|| code
== NE_EXPR
)
5488 && ((truth_value_p (TREE_CODE (arg0
))
5489 && (truth_value_p (TREE_CODE (arg1
))
5490 || (TREE_CODE (arg1
) == BIT_AND_EXPR
5491 && integer_onep (TREE_OPERAND (arg1
, 1)))))
5492 || (truth_value_p (TREE_CODE (arg1
))
5493 && (truth_value_p (TREE_CODE (arg0
))
5494 || (TREE_CODE (arg0
) == BIT_AND_EXPR
5495 && integer_onep (TREE_OPERAND (arg0
, 1)))))))
5497 t
= fold (build (code
== BIT_AND_EXPR
? TRUTH_AND_EXPR
5498 : code
== BIT_IOR_EXPR
? TRUTH_OR_EXPR
5502 if (code
== EQ_EXPR
)
5503 t
= invert_truthvalue (t
);
5508 if (TREE_CODE_CLASS (code
) == '1')
5510 if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
5511 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5512 fold (build1 (code
, type
, TREE_OPERAND (arg0
, 1))));
5513 else if (TREE_CODE (arg0
) == COND_EXPR
)
5515 tree arg01
= TREE_OPERAND (arg0
, 1);
5516 tree arg02
= TREE_OPERAND (arg0
, 2);
5517 if (! VOID_TYPE_P (TREE_TYPE (arg01
)))
5518 arg01
= fold (build1 (code
, type
, arg01
));
5519 if (! VOID_TYPE_P (TREE_TYPE (arg02
)))
5520 arg02
= fold (build1 (code
, type
, arg02
));
5521 t
= fold (build (COND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5524 /* If this was a conversion, and all we did was to move into
5525 inside the COND_EXPR, bring it back out. But leave it if
5526 it is a conversion from integer to integer and the
5527 result precision is no wider than a word since such a
5528 conversion is cheap and may be optimized away by combine,
5529 while it couldn't if it were outside the COND_EXPR. Then return
5530 so we don't get into an infinite recursion loop taking the
5531 conversion out and then back in. */
5533 if ((code
== NOP_EXPR
|| code
== CONVERT_EXPR
5534 || code
== NON_LVALUE_EXPR
)
5535 && TREE_CODE (t
) == COND_EXPR
5536 && TREE_CODE (TREE_OPERAND (t
, 1)) == code
5537 && TREE_CODE (TREE_OPERAND (t
, 2)) == code
5538 && ! VOID_TYPE_P (TREE_OPERAND (t
, 1))
5539 && ! VOID_TYPE_P (TREE_OPERAND (t
, 2))
5540 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0))
5541 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 2), 0)))
5542 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t
))
5544 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0))))
5545 && TYPE_PRECISION (TREE_TYPE (t
)) <= BITS_PER_WORD
))
5546 t
= build1 (code
, type
,
5548 TREE_TYPE (TREE_OPERAND
5549 (TREE_OPERAND (t
, 1), 0)),
5550 TREE_OPERAND (t
, 0),
5551 TREE_OPERAND (TREE_OPERAND (t
, 1), 0),
5552 TREE_OPERAND (TREE_OPERAND (t
, 2), 0)));
5555 else if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<')
5556 return fold (build (COND_EXPR
, type
, arg0
,
5557 fold (build1 (code
, type
, integer_one_node
)),
5558 fold (build1 (code
, type
, integer_zero_node
))));
5560 else if (TREE_CODE_CLASS (code
) == '<'
5561 && TREE_CODE (arg0
) == COMPOUND_EXPR
)
5562 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5563 fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
5564 else if (TREE_CODE_CLASS (code
) == '<'
5565 && TREE_CODE (arg1
) == COMPOUND_EXPR
)
5566 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
5567 fold (build (code
, type
, arg0
, TREE_OPERAND (arg1
, 1))));
5568 else if (TREE_CODE_CLASS (code
) == '2'
5569 || TREE_CODE_CLASS (code
) == '<')
5571 if (TREE_CODE (arg1
) == COMPOUND_EXPR
5572 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1
, 0))
5573 && ! TREE_SIDE_EFFECTS (arg0
))
5574 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
5575 fold (build (code
, type
,
5576 arg0
, TREE_OPERAND (arg1
, 1))));
5577 else if ((TREE_CODE (arg1
) == COND_EXPR
5578 || (TREE_CODE_CLASS (TREE_CODE (arg1
)) == '<'
5579 && TREE_CODE_CLASS (code
) != '<'))
5580 && (TREE_CODE (arg0
) != COND_EXPR
5581 || count_cond (arg0
, 25) + count_cond (arg1
, 25) <= 25)
5582 && (! TREE_SIDE_EFFECTS (arg0
)
5583 || ((*lang_hooks
.decls
.global_bindings_p
) () == 0
5584 && ! CONTAINS_PLACEHOLDER_P (arg0
))))
5586 fold_binary_op_with_conditional_arg (code
, type
, arg1
, arg0
,
5587 /*cond_first_p=*/0);
5588 else if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
5589 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5590 fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
5591 else if ((TREE_CODE (arg0
) == COND_EXPR
5592 || (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
5593 && TREE_CODE_CLASS (code
) != '<'))
5594 && (TREE_CODE (arg1
) != COND_EXPR
5595 || count_cond (arg0
, 25) + count_cond (arg1
, 25) <= 25)
5596 && (! TREE_SIDE_EFFECTS (arg1
)
5597 || ((*lang_hooks
.decls
.global_bindings_p
) () == 0
5598 && ! CONTAINS_PLACEHOLDER_P (arg1
))))
5600 fold_binary_op_with_conditional_arg (code
, type
, arg0
, arg1
,
5601 /*cond_first_p=*/1);
5615 return fold (DECL_INITIAL (t
));
5620 case FIX_TRUNC_EXPR
:
5622 case FIX_FLOOR_EXPR
:
5623 if (TREE_TYPE (TREE_OPERAND (t
, 0)) == TREE_TYPE (t
))
5624 return TREE_OPERAND (t
, 0);
5626 /* Handle cases of two conversions in a row. */
5627 if (TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
5628 || TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
)
5630 tree inside_type
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5631 tree inter_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
5632 tree final_type
= TREE_TYPE (t
);
5633 int inside_int
= INTEGRAL_TYPE_P (inside_type
);
5634 int inside_ptr
= POINTER_TYPE_P (inside_type
);
5635 int inside_float
= FLOAT_TYPE_P (inside_type
);
5636 unsigned int inside_prec
= TYPE_PRECISION (inside_type
);
5637 int inside_unsignedp
= TREE_UNSIGNED (inside_type
);
5638 int inter_int
= INTEGRAL_TYPE_P (inter_type
);
5639 int inter_ptr
= POINTER_TYPE_P (inter_type
);
5640 int inter_float
= FLOAT_TYPE_P (inter_type
);
5641 unsigned int inter_prec
= TYPE_PRECISION (inter_type
);
5642 int inter_unsignedp
= TREE_UNSIGNED (inter_type
);
5643 int final_int
= INTEGRAL_TYPE_P (final_type
);
5644 int final_ptr
= POINTER_TYPE_P (final_type
);
5645 int final_float
= FLOAT_TYPE_P (final_type
);
5646 unsigned int final_prec
= TYPE_PRECISION (final_type
);
5647 int final_unsignedp
= TREE_UNSIGNED (final_type
);
5649 /* In addition to the cases of two conversions in a row
5650 handled below, if we are converting something to its own
5651 type via an object of identical or wider precision, neither
5652 conversion is needed. */
5653 if (TYPE_MAIN_VARIANT (inside_type
) == TYPE_MAIN_VARIANT (final_type
)
5654 && ((inter_int
&& final_int
) || (inter_float
&& final_float
))
5655 && inter_prec
>= final_prec
)
5656 return fold (build1 (code
, final_type
,
5657 TREE_OPERAND (TREE_OPERAND (t
, 0), 0)));
5659 /* Likewise, if the intermediate and final types are either both
5660 float or both integer, we don't need the middle conversion if
5661 it is wider than the final type and doesn't change the signedness
5662 (for integers). Avoid this if the final type is a pointer
5663 since then we sometimes need the inner conversion. Likewise if
5664 the outer has a precision not equal to the size of its mode. */
5665 if ((((inter_int
|| inter_ptr
) && (inside_int
|| inside_ptr
))
5666 || (inter_float
&& inside_float
))
5667 && inter_prec
>= inside_prec
5668 && (inter_float
|| inter_unsignedp
== inside_unsignedp
)
5669 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (final_type
))
5670 && TYPE_MODE (final_type
) == TYPE_MODE (inter_type
))
5672 return fold (build1 (code
, final_type
,
5673 TREE_OPERAND (TREE_OPERAND (t
, 0), 0)));
5675 /* If we have a sign-extension of a zero-extended value, we can
5676 replace that by a single zero-extension. */
5677 if (inside_int
&& inter_int
&& final_int
5678 && inside_prec
< inter_prec
&& inter_prec
< final_prec
5679 && inside_unsignedp
&& !inter_unsignedp
)
5680 return fold (build1 (code
, final_type
,
5681 TREE_OPERAND (TREE_OPERAND (t
, 0), 0)));
5683 /* Two conversions in a row are not needed unless:
5684 - some conversion is floating-point (overstrict for now), or
5685 - the intermediate type is narrower than both initial and
5687 - the intermediate type and innermost type differ in signedness,
5688 and the outermost type is wider than the intermediate, or
5689 - the initial type is a pointer type and the precisions of the
5690 intermediate and final types differ, or
5691 - the final type is a pointer type and the precisions of the
5692 initial and intermediate types differ. */
5693 if (! inside_float
&& ! inter_float
&& ! final_float
5694 && (inter_prec
> inside_prec
|| inter_prec
> final_prec
)
5695 && ! (inside_int
&& inter_int
5696 && inter_unsignedp
!= inside_unsignedp
5697 && inter_prec
< final_prec
)
5698 && ((inter_unsignedp
&& inter_prec
> inside_prec
)
5699 == (final_unsignedp
&& final_prec
> inter_prec
))
5700 && ! (inside_ptr
&& inter_prec
!= final_prec
)
5701 && ! (final_ptr
&& inside_prec
!= inter_prec
)
5702 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (final_type
))
5703 && TYPE_MODE (final_type
) == TYPE_MODE (inter_type
))
5705 return fold (build1 (code
, final_type
,
5706 TREE_OPERAND (TREE_OPERAND (t
, 0), 0)));
5709 if (TREE_CODE (TREE_OPERAND (t
, 0)) == MODIFY_EXPR
5710 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t
, 0), 1))
5711 /* Detect assigning a bitfield. */
5712 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0)) == COMPONENT_REF
5713 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t
, 0), 0), 1))))
5715 /* Don't leave an assignment inside a conversion
5716 unless assigning a bitfield. */
5717 tree prev
= TREE_OPERAND (t
, 0);
5720 TREE_OPERAND (t
, 0) = TREE_OPERAND (prev
, 1);
5721 /* First do the assignment, then return converted constant. */
5722 t
= build (COMPOUND_EXPR
, TREE_TYPE (t
), prev
, fold (t
));
5727 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
5728 constants (if x has signed type, the sign bit cannot be set
5729 in c). This folds extension into the BIT_AND_EXPR. */
5730 if (INTEGRAL_TYPE_P (TREE_TYPE (t
))
5731 && TREE_CODE (TREE_TYPE (t
)) != BOOLEAN_TYPE
5732 && TREE_CODE (TREE_OPERAND (t
, 0)) == BIT_AND_EXPR
5733 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 1)) == INTEGER_CST
)
5735 tree
and = TREE_OPERAND (t
, 0);
5736 tree and0
= TREE_OPERAND (and, 0), and1
= TREE_OPERAND (and, 1);
5739 if (TREE_UNSIGNED (TREE_TYPE (and))
5740 || (TYPE_PRECISION (TREE_TYPE (t
))
5741 <= TYPE_PRECISION (TREE_TYPE (and))))
5743 else if (TYPE_PRECISION (TREE_TYPE (and1
))
5744 <= HOST_BITS_PER_WIDE_INT
5745 && host_integerp (and1
, 1))
5747 unsigned HOST_WIDE_INT cst
;
5749 cst
= tree_low_cst (and1
, 1);
5750 cst
&= (HOST_WIDE_INT
) -1
5751 << (TYPE_PRECISION (TREE_TYPE (and1
)) - 1);
5752 change
= (cst
== 0);
5753 #ifdef LOAD_EXTEND_OP
5755 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0
)))
5758 tree uns
= (*lang_hooks
.types
.unsigned_type
) (TREE_TYPE (and0
));
5759 and0
= fold_convert (uns
, and0
);
5760 and1
= fold_convert (uns
, and1
);
5765 return fold (build (BIT_AND_EXPR
, TREE_TYPE (t
),
5766 fold_convert (TREE_TYPE (t
), and0
),
5767 fold_convert (TREE_TYPE (t
), and1
)));
5770 tem
= fold_convert_const (code
, TREE_TYPE (t
), arg0
);
5771 return tem
? tem
: t
;
5773 case VIEW_CONVERT_EXPR
:
5774 if (TREE_CODE (TREE_OPERAND (t
, 0)) == VIEW_CONVERT_EXPR
)
5775 return build1 (VIEW_CONVERT_EXPR
, type
,
5776 TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5780 if (TREE_CODE (arg0
) == CONSTRUCTOR
5781 && ! type_contains_placeholder_p (TREE_TYPE (arg0
)))
5783 tree m
= purpose_member (arg1
, CONSTRUCTOR_ELTS (arg0
));
5790 if (TREE_CONSTANT (t
) != wins
)
5794 TREE_CONSTANT (t
) = wins
;
5799 if (negate_expr_p (arg0
))
5800 return fold_convert (type
, negate_expr (arg0
));
5806 if (TREE_CODE (arg0
) == INTEGER_CST
)
5808 /* If the value is unsigned, then the absolute value is
5809 the same as the ordinary value. */
5810 if (TREE_UNSIGNED (type
))
5812 /* Similarly, if the value is non-negative. */
5813 else if (INT_CST_LT (integer_minus_one_node
, arg0
))
5815 /* If the value is negative, then the absolute value is
5819 unsigned HOST_WIDE_INT low
;
5821 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
5822 TREE_INT_CST_HIGH (arg0
),
5824 t
= build_int_2 (low
, high
);
5825 TREE_TYPE (t
) = type
;
5827 = (TREE_OVERFLOW (arg0
)
5828 | force_fit_type (t
, overflow
));
5829 TREE_CONSTANT_OVERFLOW (t
)
5830 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg0
);
5833 else if (TREE_CODE (arg0
) == REAL_CST
)
5835 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0
)))
5836 t
= build_real (type
,
5837 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
5840 else if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5841 return fold (build1 (ABS_EXPR
, type
, TREE_OPERAND (arg0
, 0)));
5842 /* Convert fabs((double)float) into (double)fabsf(float). */
5843 else if (TREE_CODE (arg0
) == NOP_EXPR
5844 && TREE_CODE (type
) == REAL_TYPE
)
5846 tree targ0
= strip_float_extensions (arg0
);
5848 return fold_convert (type
, fold (build1 (ABS_EXPR
,
5852 else if (tree_expr_nonnegative_p (arg0
))
5857 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
5858 return fold_convert (type
, arg0
);
5859 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
5860 return build (COMPLEX_EXPR
, type
,
5861 TREE_OPERAND (arg0
, 0),
5862 negate_expr (TREE_OPERAND (arg0
, 1)));
5863 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
5864 return build_complex (type
, TREE_REALPART (arg0
),
5865 negate_expr (TREE_IMAGPART (arg0
)));
5866 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
5867 return fold (build (TREE_CODE (arg0
), type
,
5868 fold (build1 (CONJ_EXPR
, type
,
5869 TREE_OPERAND (arg0
, 0))),
5870 fold (build1 (CONJ_EXPR
,
5871 type
, TREE_OPERAND (arg0
, 1)))));
5872 else if (TREE_CODE (arg0
) == CONJ_EXPR
)
5873 return TREE_OPERAND (arg0
, 0);
5879 t
= build_int_2 (~ TREE_INT_CST_LOW (arg0
),
5880 ~ TREE_INT_CST_HIGH (arg0
));
5881 TREE_TYPE (t
) = type
;
5882 force_fit_type (t
, 0);
5883 TREE_OVERFLOW (t
) = TREE_OVERFLOW (arg0
);
5884 TREE_CONSTANT_OVERFLOW (t
) = TREE_CONSTANT_OVERFLOW (arg0
);
5886 else if (TREE_CODE (arg0
) == BIT_NOT_EXPR
)
5887 return TREE_OPERAND (arg0
, 0);
5891 /* A + (-B) -> A - B */
5892 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
5893 return fold (build (MINUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
5894 /* (-A) + B -> B - A */
5895 if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5896 return fold (build (MINUS_EXPR
, type
, arg1
, TREE_OPERAND (arg0
, 0)));
5897 else if (! FLOAT_TYPE_P (type
))
5899 if (integer_zerop (arg1
))
5900 return non_lvalue (fold_convert (type
, arg0
));
5902 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5903 with a constant, and the two constants have no bits in common,
5904 we should treat this as a BIT_IOR_EXPR since this may produce more
5906 if (TREE_CODE (arg0
) == BIT_AND_EXPR
5907 && TREE_CODE (arg1
) == BIT_AND_EXPR
5908 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
5909 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
5910 && integer_zerop (const_binop (BIT_AND_EXPR
,
5911 TREE_OPERAND (arg0
, 1),
5912 TREE_OPERAND (arg1
, 1), 0)))
5914 code
= BIT_IOR_EXPR
;
5918 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5919 (plus (plus (mult) (mult)) (foo)) so that we can
5920 take advantage of the factoring cases below. */
5921 if ((TREE_CODE (arg0
) == PLUS_EXPR
5922 && TREE_CODE (arg1
) == MULT_EXPR
)
5923 || (TREE_CODE (arg1
) == PLUS_EXPR
5924 && TREE_CODE (arg0
) == MULT_EXPR
))
5926 tree parg0
, parg1
, parg
, marg
;
5928 if (TREE_CODE (arg0
) == PLUS_EXPR
)
5929 parg
= arg0
, marg
= arg1
;
5931 parg
= arg1
, marg
= arg0
;
5932 parg0
= TREE_OPERAND (parg
, 0);
5933 parg1
= TREE_OPERAND (parg
, 1);
5937 if (TREE_CODE (parg0
) == MULT_EXPR
5938 && TREE_CODE (parg1
) != MULT_EXPR
)
5939 return fold (build (PLUS_EXPR
, type
,
5940 fold (build (PLUS_EXPR
, type
,
5941 fold_convert (type
, parg0
),
5942 fold_convert (type
, marg
))),
5943 fold_convert (type
, parg1
)));
5944 if (TREE_CODE (parg0
) != MULT_EXPR
5945 && TREE_CODE (parg1
) == MULT_EXPR
)
5946 return fold (build (PLUS_EXPR
, type
,
5947 fold (build (PLUS_EXPR
, type
,
5948 fold_convert (type
, parg1
),
5949 fold_convert (type
, marg
))),
5950 fold_convert (type
, parg0
)));
5953 if (TREE_CODE (arg0
) == MULT_EXPR
&& TREE_CODE (arg1
) == MULT_EXPR
)
5955 tree arg00
, arg01
, arg10
, arg11
;
5956 tree alt0
= NULL_TREE
, alt1
= NULL_TREE
, same
;
5958 /* (A * C) + (B * C) -> (A+B) * C.
5959 We are most concerned about the case where C is a constant,
5960 but other combinations show up during loop reduction. Since
5961 it is not difficult, try all four possibilities. */
5963 arg00
= TREE_OPERAND (arg0
, 0);
5964 arg01
= TREE_OPERAND (arg0
, 1);
5965 arg10
= TREE_OPERAND (arg1
, 0);
5966 arg11
= TREE_OPERAND (arg1
, 1);
5969 if (operand_equal_p (arg01
, arg11
, 0))
5970 same
= arg01
, alt0
= arg00
, alt1
= arg10
;
5971 else if (operand_equal_p (arg00
, arg10
, 0))
5972 same
= arg00
, alt0
= arg01
, alt1
= arg11
;
5973 else if (operand_equal_p (arg00
, arg11
, 0))
5974 same
= arg00
, alt0
= arg01
, alt1
= arg10
;
5975 else if (operand_equal_p (arg01
, arg10
, 0))
5976 same
= arg01
, alt0
= arg00
, alt1
= arg11
;
5978 /* No identical multiplicands; see if we can find a common
5979 power-of-two factor in non-power-of-two multiplies. This
5980 can help in multi-dimensional array access. */
5981 else if (TREE_CODE (arg01
) == INTEGER_CST
5982 && TREE_CODE (arg11
) == INTEGER_CST
5983 && TREE_INT_CST_HIGH (arg01
) == 0
5984 && TREE_INT_CST_HIGH (arg11
) == 0)
5986 HOST_WIDE_INT int01
, int11
, tmp
;
5987 int01
= TREE_INT_CST_LOW (arg01
);
5988 int11
= TREE_INT_CST_LOW (arg11
);
5990 /* Move min of absolute values to int11. */
5991 if ((int01
>= 0 ? int01
: -int01
)
5992 < (int11
>= 0 ? int11
: -int11
))
5994 tmp
= int01
, int01
= int11
, int11
= tmp
;
5995 alt0
= arg00
, arg00
= arg10
, arg10
= alt0
;
5996 alt0
= arg01
, arg01
= arg11
, arg11
= alt0
;
5999 if (exact_log2 (int11
) > 0 && int01
% int11
== 0)
6001 alt0
= fold (build (MULT_EXPR
, type
, arg00
,
6002 build_int_2 (int01
/ int11
, 0)));
6009 return fold (build (MULT_EXPR
, type
,
6010 fold (build (PLUS_EXPR
, type
, alt0
, alt1
)),
6016 /* See if ARG1 is zero and X + ARG1 reduces to X. */
6017 if (fold_real_zero_addition_p (TREE_TYPE (arg0
), arg1
, 0))
6018 return non_lvalue (fold_convert (type
, arg0
));
6020 /* Likewise if the operands are reversed. */
6021 if (fold_real_zero_addition_p (TREE_TYPE (arg1
), arg0
, 0))
6022 return non_lvalue (fold_convert (type
, arg1
));
6024 /* Convert x+x into x*2.0. */
6025 if (operand_equal_p (arg0
, arg1
, 0)
6026 && SCALAR_FLOAT_TYPE_P (type
))
6027 return fold (build (MULT_EXPR
, type
, arg0
,
6028 build_real (type
, dconst2
)));
6030 /* Convert x*c+x into x*(c+1). */
6031 if (flag_unsafe_math_optimizations
6032 && TREE_CODE (arg0
) == MULT_EXPR
6033 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == REAL_CST
6034 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0
, 1))
6035 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
6039 c
= TREE_REAL_CST (TREE_OPERAND (arg0
, 1));
6040 real_arithmetic (&c
, PLUS_EXPR
, &c
, &dconst1
);
6041 return fold (build (MULT_EXPR
, type
, arg1
,
6042 build_real (type
, c
)));
6045 /* Convert x+x*c into x*(c+1). */
6046 if (flag_unsafe_math_optimizations
6047 && TREE_CODE (arg1
) == MULT_EXPR
6048 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == REAL_CST
6049 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1
, 1))
6050 && operand_equal_p (TREE_OPERAND (arg1
, 0), arg0
, 0))
6054 c
= TREE_REAL_CST (TREE_OPERAND (arg1
, 1));
6055 real_arithmetic (&c
, PLUS_EXPR
, &c
, &dconst1
);
6056 return fold (build (MULT_EXPR
, type
, arg0
,
6057 build_real (type
, c
)));
6060 /* Convert x*c1+x*c2 into x*(c1+c2). */
6061 if (flag_unsafe_math_optimizations
6062 && TREE_CODE (arg0
) == MULT_EXPR
6063 && TREE_CODE (arg1
) == MULT_EXPR
6064 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == REAL_CST
6065 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0
, 1))
6066 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == REAL_CST
6067 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1
, 1))
6068 && operand_equal_p (TREE_OPERAND (arg0
, 0),
6069 TREE_OPERAND (arg1
, 0), 0))
6071 REAL_VALUE_TYPE c1
, c2
;
6073 c1
= TREE_REAL_CST (TREE_OPERAND (arg0
, 1));
6074 c2
= TREE_REAL_CST (TREE_OPERAND (arg1
, 1));
6075 real_arithmetic (&c1
, PLUS_EXPR
, &c1
, &c2
);
6076 return fold (build (MULT_EXPR
, type
,
6077 TREE_OPERAND (arg0
, 0),
6078 build_real (type
, c1
)));
6083 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
6084 is a rotate of A by C1 bits. */
6085 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
6086 is a rotate of A by B bits. */
6088 enum tree_code code0
, code1
;
6089 code0
= TREE_CODE (arg0
);
6090 code1
= TREE_CODE (arg1
);
6091 if (((code0
== RSHIFT_EXPR
&& code1
== LSHIFT_EXPR
)
6092 || (code1
== RSHIFT_EXPR
&& code0
== LSHIFT_EXPR
))
6093 && operand_equal_p (TREE_OPERAND (arg0
, 0),
6094 TREE_OPERAND (arg1
, 0), 0)
6095 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
6097 tree tree01
, tree11
;
6098 enum tree_code code01
, code11
;
6100 tree01
= TREE_OPERAND (arg0
, 1);
6101 tree11
= TREE_OPERAND (arg1
, 1);
6102 STRIP_NOPS (tree01
);
6103 STRIP_NOPS (tree11
);
6104 code01
= TREE_CODE (tree01
);
6105 code11
= TREE_CODE (tree11
);
6106 if (code01
== INTEGER_CST
6107 && code11
== INTEGER_CST
6108 && TREE_INT_CST_HIGH (tree01
) == 0
6109 && TREE_INT_CST_HIGH (tree11
) == 0
6110 && ((TREE_INT_CST_LOW (tree01
) + TREE_INT_CST_LOW (tree11
))
6111 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)))))
6112 return build (LROTATE_EXPR
, type
, TREE_OPERAND (arg0
, 0),
6113 code0
== LSHIFT_EXPR
? tree01
: tree11
);
6114 else if (code11
== MINUS_EXPR
)
6116 tree tree110
, tree111
;
6117 tree110
= TREE_OPERAND (tree11
, 0);
6118 tree111
= TREE_OPERAND (tree11
, 1);
6119 STRIP_NOPS (tree110
);
6120 STRIP_NOPS (tree111
);
6121 if (TREE_CODE (tree110
) == INTEGER_CST
6122 && 0 == compare_tree_int (tree110
,
6124 (TREE_TYPE (TREE_OPERAND
6126 && operand_equal_p (tree01
, tree111
, 0))
6127 return build ((code0
== LSHIFT_EXPR
6130 type
, TREE_OPERAND (arg0
, 0), tree01
);
6132 else if (code01
== MINUS_EXPR
)
6134 tree tree010
, tree011
;
6135 tree010
= TREE_OPERAND (tree01
, 0);
6136 tree011
= TREE_OPERAND (tree01
, 1);
6137 STRIP_NOPS (tree010
);
6138 STRIP_NOPS (tree011
);
6139 if (TREE_CODE (tree010
) == INTEGER_CST
6140 && 0 == compare_tree_int (tree010
,
6142 (TREE_TYPE (TREE_OPERAND
6144 && operand_equal_p (tree11
, tree011
, 0))
6145 return build ((code0
!= LSHIFT_EXPR
6148 type
, TREE_OPERAND (arg0
, 0), tree11
);
6154 /* In most languages, can't associate operations on floats through
6155 parentheses. Rather than remember where the parentheses were, we
6156 don't associate floats at all, unless the user has specified
6157 -funsafe-math-optimizations. */
6160 && (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
))
6162 tree var0
, con0
, lit0
, minus_lit0
;
6163 tree var1
, con1
, lit1
, minus_lit1
;
6165 /* Split both trees into variables, constants, and literals. Then
6166 associate each group together, the constants with literals,
6167 then the result with variables. This increases the chances of
6168 literals being recombined later and of generating relocatable
6169 expressions for the sum of a constant and literal. */
6170 var0
= split_tree (arg0
, code
, &con0
, &lit0
, &minus_lit0
, 0);
6171 var1
= split_tree (arg1
, code
, &con1
, &lit1
, &minus_lit1
,
6172 code
== MINUS_EXPR
);
6174 /* Only do something if we found more than two objects. Otherwise,
6175 nothing has changed and we risk infinite recursion. */
6176 if (2 < ((var0
!= 0) + (var1
!= 0)
6177 + (con0
!= 0) + (con1
!= 0)
6178 + (lit0
!= 0) + (lit1
!= 0)
6179 + (minus_lit0
!= 0) + (minus_lit1
!= 0)))
6181 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
6182 if (code
== MINUS_EXPR
)
6185 var0
= associate_trees (var0
, var1
, code
, type
);
6186 con0
= associate_trees (con0
, con1
, code
, type
);
6187 lit0
= associate_trees (lit0
, lit1
, code
, type
);
6188 minus_lit0
= associate_trees (minus_lit0
, minus_lit1
, code
, type
);
6190 /* Preserve the MINUS_EXPR if the negative part of the literal is
6191 greater than the positive part. Otherwise, the multiplicative
6192 folding code (i.e extract_muldiv) may be fooled in case
6193 unsigned constants are subtracted, like in the following
6194 example: ((X*2 + 4) - 8U)/2. */
6195 if (minus_lit0
&& lit0
)
6197 if (TREE_CODE (lit0
) == INTEGER_CST
6198 && TREE_CODE (minus_lit0
) == INTEGER_CST
6199 && tree_int_cst_lt (lit0
, minus_lit0
))
6201 minus_lit0
= associate_trees (minus_lit0
, lit0
,
6207 lit0
= associate_trees (lit0
, minus_lit0
,
6215 return fold_convert (type
,
6216 associate_trees (var0
, minus_lit0
,
6220 con0
= associate_trees (con0
, minus_lit0
,
6222 return fold_convert (type
,
6223 associate_trees (var0
, con0
,
6228 con0
= associate_trees (con0
, lit0
, code
, type
);
6229 return fold_convert (type
, associate_trees (var0
, con0
,
6236 t1
= const_binop (code
, arg0
, arg1
, 0);
6237 if (t1
!= NULL_TREE
)
6239 /* The return value should always have
6240 the same type as the original expression. */
6241 if (TREE_TYPE (t1
) != TREE_TYPE (t
))
6242 t1
= fold_convert (TREE_TYPE (t
), t1
);
6249 /* A - (-B) -> A + B */
6250 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
6251 return fold (build (PLUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
6252 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
6253 if (TREE_CODE (arg0
) == NEGATE_EXPR
6254 && (FLOAT_TYPE_P (type
)
6255 || (INTEGRAL_TYPE_P (type
) && flag_wrapv
&& !flag_trapv
))
6256 && negate_expr_p (arg1
)
6257 && reorder_operands_p (arg0
, arg1
))
6258 return fold (build (MINUS_EXPR
, type
, negate_expr (arg1
),
6259 TREE_OPERAND (arg0
, 0)));
6261 if (! FLOAT_TYPE_P (type
))
6263 if (! wins
&& integer_zerop (arg0
))
6264 return negate_expr (fold_convert (type
, arg1
));
6265 if (integer_zerop (arg1
))
6266 return non_lvalue (fold_convert (type
, arg0
));
6268 /* Fold A - (A & B) into ~B & A. */
6269 if (!TREE_SIDE_EFFECTS (arg0
)
6270 && TREE_CODE (arg1
) == BIT_AND_EXPR
)
6272 if (operand_equal_p (arg0
, TREE_OPERAND (arg1
, 1), 0))
6273 return fold (build (BIT_AND_EXPR
, type
,
6274 fold (build1 (BIT_NOT_EXPR
, type
,
6275 TREE_OPERAND (arg1
, 0))),
6277 if (operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
6278 return fold (build (BIT_AND_EXPR
, type
,
6279 fold (build1 (BIT_NOT_EXPR
, type
,
6280 TREE_OPERAND (arg1
, 1))),
6284 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
6285 any power of 2 minus 1. */
6286 if (TREE_CODE (arg0
) == BIT_AND_EXPR
6287 && TREE_CODE (arg1
) == BIT_AND_EXPR
6288 && operand_equal_p (TREE_OPERAND (arg0
, 0),
6289 TREE_OPERAND (arg1
, 0), 0))
6291 tree mask0
= TREE_OPERAND (arg0
, 1);
6292 tree mask1
= TREE_OPERAND (arg1
, 1);
6293 tree tem
= fold (build1 (BIT_NOT_EXPR
, type
, mask0
));
6295 if (operand_equal_p (tem
, mask1
, 0))
6297 tem
= fold (build (BIT_XOR_EXPR
, type
,
6298 TREE_OPERAND (arg0
, 0), mask1
));
6299 return fold (build (MINUS_EXPR
, type
, tem
, mask1
));
6304 /* See if ARG1 is zero and X - ARG1 reduces to X. */
6305 else if (fold_real_zero_addition_p (TREE_TYPE (arg0
), arg1
, 1))
6306 return non_lvalue (fold_convert (type
, arg0
));
6308 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
6309 ARG0 is zero and X + ARG0 reduces to X, since that would mean
6310 (-ARG1 + ARG0) reduces to -ARG1. */
6311 else if (!wins
&& fold_real_zero_addition_p (TREE_TYPE (arg1
), arg0
, 0))
6312 return negate_expr (fold_convert (type
, arg1
));
6314 /* Fold &x - &x. This can happen from &x.foo - &x.
6315 This is unsafe for certain floats even in non-IEEE formats.
6316 In IEEE, it is unsafe because it does wrong for NaNs.
6317 Also note that operand_equal_p is always false if an operand
6320 if ((! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
6321 && operand_equal_p (arg0
, arg1
, 0))
6322 return fold_convert (type
, integer_zero_node
);
6324 /* A - B -> A + (-B) if B is easily negatable. */
6325 if (!wins
&& negate_expr_p (arg1
)
6326 && (FLOAT_TYPE_P (type
)
6327 || (INTEGRAL_TYPE_P (type
) && flag_wrapv
&& !flag_trapv
)))
6328 return fold (build (PLUS_EXPR
, type
, arg0
, negate_expr (arg1
)));
6330 if (TREE_CODE (arg0
) == MULT_EXPR
6331 && TREE_CODE (arg1
) == MULT_EXPR
6332 && (INTEGRAL_TYPE_P (type
) || flag_unsafe_math_optimizations
))
6334 /* (A * C) - (B * C) -> (A-B) * C. */
6335 if (operand_equal_p (TREE_OPERAND (arg0
, 1),
6336 TREE_OPERAND (arg1
, 1), 0))
6337 return fold (build (MULT_EXPR
, type
,
6338 fold (build (MINUS_EXPR
, type
,
6339 TREE_OPERAND (arg0
, 0),
6340 TREE_OPERAND (arg1
, 0))),
6341 TREE_OPERAND (arg0
, 1)));
6342 /* (A * C1) - (A * C2) -> A * (C1-C2). */
6343 if (operand_equal_p (TREE_OPERAND (arg0
, 0),
6344 TREE_OPERAND (arg1
, 0), 0))
6345 return fold (build (MULT_EXPR
, type
,
6346 TREE_OPERAND (arg0
, 0),
6347 fold (build (MINUS_EXPR
, type
,
6348 TREE_OPERAND (arg0
, 1),
6349 TREE_OPERAND (arg1
, 1)))));
6355 /* (-A) * (-B) -> A * B */
6356 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& negate_expr_p (arg1
))
6357 return fold (build (MULT_EXPR
, type
,
6358 TREE_OPERAND (arg0
, 0),
6359 negate_expr (arg1
)));
6360 if (TREE_CODE (arg1
) == NEGATE_EXPR
&& negate_expr_p (arg0
))
6361 return fold (build (MULT_EXPR
, type
,
6363 TREE_OPERAND (arg1
, 0)));
6365 if (! FLOAT_TYPE_P (type
))
6367 if (integer_zerop (arg1
))
6368 return omit_one_operand (type
, arg1
, arg0
);
6369 if (integer_onep (arg1
))
6370 return non_lvalue (fold_convert (type
, arg0
));
6372 /* (a * (1 << b)) is (a << b) */
6373 if (TREE_CODE (arg1
) == LSHIFT_EXPR
6374 && integer_onep (TREE_OPERAND (arg1
, 0)))
6375 return fold (build (LSHIFT_EXPR
, type
, arg0
,
6376 TREE_OPERAND (arg1
, 1)));
6377 if (TREE_CODE (arg0
) == LSHIFT_EXPR
6378 && integer_onep (TREE_OPERAND (arg0
, 0)))
6379 return fold (build (LSHIFT_EXPR
, type
, arg1
,
6380 TREE_OPERAND (arg0
, 1)));
6382 if (TREE_CODE (arg1
) == INTEGER_CST
6383 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0),
6384 fold_convert (type
, arg1
),
6386 return fold_convert (type
, tem
);
6391 /* Maybe fold x * 0 to 0. The expressions aren't the same
6392 when x is NaN, since x * 0 is also NaN. Nor are they the
6393 same in modes with signed zeros, since multiplying a
6394 negative value by 0 gives -0, not +0. */
6395 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
)))
6396 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0
)))
6397 && real_zerop (arg1
))
6398 return omit_one_operand (type
, arg1
, arg0
);
6399 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
6400 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
6401 && real_onep (arg1
))
6402 return non_lvalue (fold_convert (type
, arg0
));
6404 /* Transform x * -1.0 into -x. */
6405 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
6406 && real_minus_onep (arg1
))
6407 return fold (build1 (NEGATE_EXPR
, type
, arg0
));
6409 /* Convert (C1/X)*C2 into (C1*C2)/X. */
6410 if (flag_unsafe_math_optimizations
6411 && TREE_CODE (arg0
) == RDIV_EXPR
6412 && TREE_CODE (arg1
) == REAL_CST
6413 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == REAL_CST
)
6415 tree tem
= const_binop (MULT_EXPR
, TREE_OPERAND (arg0
, 0),
6418 return fold (build (RDIV_EXPR
, type
, tem
,
6419 TREE_OPERAND (arg0
, 1)));
6422 if (flag_unsafe_math_optimizations
)
6424 enum built_in_function fcode0
= builtin_mathfn_code (arg0
);
6425 enum built_in_function fcode1
= builtin_mathfn_code (arg1
);
6427 /* Optimizations of sqrt(...)*sqrt(...). */
6428 if ((fcode0
== BUILT_IN_SQRT
&& fcode1
== BUILT_IN_SQRT
)
6429 || (fcode0
== BUILT_IN_SQRTF
&& fcode1
== BUILT_IN_SQRTF
)
6430 || (fcode0
== BUILT_IN_SQRTL
&& fcode1
== BUILT_IN_SQRTL
))
6432 tree sqrtfn
, arg
, arglist
;
6433 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
6434 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
6436 /* Optimize sqrt(x)*sqrt(x) as x. */
6437 if (operand_equal_p (arg00
, arg10
, 0)
6438 && ! HONOR_SNANS (TYPE_MODE (type
)))
6441 /* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */
6442 sqrtfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
6443 arg
= fold (build (MULT_EXPR
, type
, arg00
, arg10
));
6444 arglist
= build_tree_list (NULL_TREE
, arg
);
6445 return build_function_call_expr (sqrtfn
, arglist
);
6448 /* Optimize expN(x)*expN(y) as expN(x+y). */
6449 if (fcode0
== fcode1
6450 && (fcode0
== BUILT_IN_EXP
6451 || fcode0
== BUILT_IN_EXPF
6452 || fcode0
== BUILT_IN_EXPL
6453 || fcode0
== BUILT_IN_EXP2
6454 || fcode0
== BUILT_IN_EXP2F
6455 || fcode0
== BUILT_IN_EXP2L
6456 || fcode0
== BUILT_IN_EXP10
6457 || fcode0
== BUILT_IN_EXP10F
6458 || fcode0
== BUILT_IN_EXP10L
6459 || fcode0
== BUILT_IN_POW10
6460 || fcode0
== BUILT_IN_POW10F
6461 || fcode0
== BUILT_IN_POW10L
))
6463 tree expfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
6464 tree arg
= build (PLUS_EXPR
, type
,
6465 TREE_VALUE (TREE_OPERAND (arg0
, 1)),
6466 TREE_VALUE (TREE_OPERAND (arg1
, 1)));
6467 tree arglist
= build_tree_list (NULL_TREE
, fold (arg
));
6468 return build_function_call_expr (expfn
, arglist
);
6471 /* Optimizations of pow(...)*pow(...). */
6472 if ((fcode0
== BUILT_IN_POW
&& fcode1
== BUILT_IN_POW
)
6473 || (fcode0
== BUILT_IN_POWF
&& fcode1
== BUILT_IN_POWF
)
6474 || (fcode0
== BUILT_IN_POWL
&& fcode1
== BUILT_IN_POWL
))
6476 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
6477 tree arg01
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0
,
6479 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
6480 tree arg11
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1
,
6483 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
6484 if (operand_equal_p (arg01
, arg11
, 0))
6486 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
6487 tree arg
= build (MULT_EXPR
, type
, arg00
, arg10
);
6488 tree arglist
= tree_cons (NULL_TREE
, fold (arg
),
6489 build_tree_list (NULL_TREE
,
6491 return build_function_call_expr (powfn
, arglist
);
6494 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
6495 if (operand_equal_p (arg00
, arg10
, 0))
6497 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
6498 tree arg
= fold (build (PLUS_EXPR
, type
, arg01
, arg11
));
6499 tree arglist
= tree_cons (NULL_TREE
, arg00
,
6500 build_tree_list (NULL_TREE
,
6502 return build_function_call_expr (powfn
, arglist
);
6506 /* Optimize tan(x)*cos(x) as sin(x). */
6507 if (((fcode0
== BUILT_IN_TAN
&& fcode1
== BUILT_IN_COS
)
6508 || (fcode0
== BUILT_IN_TANF
&& fcode1
== BUILT_IN_COSF
)
6509 || (fcode0
== BUILT_IN_TANL
&& fcode1
== BUILT_IN_COSL
)
6510 || (fcode0
== BUILT_IN_COS
&& fcode1
== BUILT_IN_TAN
)
6511 || (fcode0
== BUILT_IN_COSF
&& fcode1
== BUILT_IN_TANF
)
6512 || (fcode0
== BUILT_IN_COSL
&& fcode1
== BUILT_IN_TANL
))
6513 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0
, 1)),
6514 TREE_VALUE (TREE_OPERAND (arg1
, 1)), 0))
6522 sinfn
= implicit_built_in_decls
[BUILT_IN_SIN
];
6526 sinfn
= implicit_built_in_decls
[BUILT_IN_SINF
];
6530 sinfn
= implicit_built_in_decls
[BUILT_IN_SINL
];
6536 if (sinfn
!= NULL_TREE
)
6537 return build_function_call_expr (sinfn
,
6538 TREE_OPERAND (arg0
, 1));
6541 /* Optimize x*pow(x,c) as pow(x,c+1). */
6542 if (fcode1
== BUILT_IN_POW
6543 || fcode1
== BUILT_IN_POWF
6544 || fcode1
== BUILT_IN_POWL
)
6546 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
6547 tree arg11
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1
,
6549 if (TREE_CODE (arg11
) == REAL_CST
6550 && ! TREE_CONSTANT_OVERFLOW (arg11
)
6551 && operand_equal_p (arg0
, arg10
, 0))
6553 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0);
6557 c
= TREE_REAL_CST (arg11
);
6558 real_arithmetic (&c
, PLUS_EXPR
, &c
, &dconst1
);
6559 arg
= build_real (type
, c
);
6560 arglist
= build_tree_list (NULL_TREE
, arg
);
6561 arglist
= tree_cons (NULL_TREE
, arg0
, arglist
);
6562 return build_function_call_expr (powfn
, arglist
);
6566 /* Optimize pow(x,c)*x as pow(x,c+1). */
6567 if (fcode0
== BUILT_IN_POW
6568 || fcode0
== BUILT_IN_POWF
6569 || fcode0
== BUILT_IN_POWL
)
6571 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
6572 tree arg01
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0
,
6574 if (TREE_CODE (arg01
) == REAL_CST
6575 && ! TREE_CONSTANT_OVERFLOW (arg01
)
6576 && operand_equal_p (arg1
, arg00
, 0))
6578 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
6582 c
= TREE_REAL_CST (arg01
);
6583 real_arithmetic (&c
, PLUS_EXPR
, &c
, &dconst1
);
6584 arg
= build_real (type
, c
);
6585 arglist
= build_tree_list (NULL_TREE
, arg
);
6586 arglist
= tree_cons (NULL_TREE
, arg1
, arglist
);
6587 return build_function_call_expr (powfn
, arglist
);
6591 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
6593 && operand_equal_p (arg0
, arg1
, 0))
6597 if (type
== double_type_node
)
6598 powfn
= implicit_built_in_decls
[BUILT_IN_POW
];
6599 else if (type
== float_type_node
)
6600 powfn
= implicit_built_in_decls
[BUILT_IN_POWF
];
6601 else if (type
== long_double_type_node
)
6602 powfn
= implicit_built_in_decls
[BUILT_IN_POWL
];
6608 tree arg
= build_real (type
, dconst2
);
6609 tree arglist
= build_tree_list (NULL_TREE
, arg
);
6610 arglist
= tree_cons (NULL_TREE
, arg0
, arglist
);
6611 return build_function_call_expr (powfn
, arglist
);
6620 if (integer_all_onesp (arg1
))
6621 return omit_one_operand (type
, arg1
, arg0
);
6622 if (integer_zerop (arg1
))
6623 return non_lvalue (fold_convert (type
, arg0
));
6624 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
6625 if (t1
!= NULL_TREE
)
6628 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
6630 This results in more efficient code for machines without a NAND
6631 instruction. Combine will canonicalize to the first form
6632 which will allow use of NAND instructions provided by the
6633 backend if they exist. */
6634 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
6635 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
6637 return fold (build1 (BIT_NOT_EXPR
, type
,
6638 build (BIT_AND_EXPR
, type
,
6639 TREE_OPERAND (arg0
, 0),
6640 TREE_OPERAND (arg1
, 0))));
6643 /* See if this can be simplified into a rotate first. If that
6644 is unsuccessful continue in the association code. */
6648 if (integer_zerop (arg1
))
6649 return non_lvalue (fold_convert (type
, arg0
));
6650 if (integer_all_onesp (arg1
))
6651 return fold (build1 (BIT_NOT_EXPR
, type
, arg0
));
6653 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
6654 with a constant, and the two constants have no bits in common,
6655 we should treat this as a BIT_IOR_EXPR since this may produce more
6657 if (TREE_CODE (arg0
) == BIT_AND_EXPR
6658 && TREE_CODE (arg1
) == BIT_AND_EXPR
6659 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
6660 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
6661 && integer_zerop (const_binop (BIT_AND_EXPR
,
6662 TREE_OPERAND (arg0
, 1),
6663 TREE_OPERAND (arg1
, 1), 0)))
6665 code
= BIT_IOR_EXPR
;
6669 /* See if this can be simplified into a rotate first. If that
6670 is unsuccessful continue in the association code. */
6674 if (integer_all_onesp (arg1
))
6675 return non_lvalue (fold_convert (type
, arg0
));
6676 if (integer_zerop (arg1
))
6677 return omit_one_operand (type
, arg1
, arg0
);
6678 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
6679 if (t1
!= NULL_TREE
)
6681 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
6682 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) == NOP_EXPR
6683 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
6686 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)));
6688 if (prec
< BITS_PER_WORD
&& prec
< HOST_BITS_PER_WIDE_INT
6689 && (~TREE_INT_CST_LOW (arg1
)
6690 & (((HOST_WIDE_INT
) 1 << prec
) - 1)) == 0)
6691 return fold_convert (type
, TREE_OPERAND (arg0
, 0));
6694 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
6696 This results in more efficient code for machines without a NOR
6697 instruction. Combine will canonicalize to the first form
6698 which will allow use of NOR instructions provided by the
6699 backend if they exist. */
6700 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
6701 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
6703 return fold (build1 (BIT_NOT_EXPR
, type
,
6704 build (BIT_IOR_EXPR
, type
,
6705 TREE_OPERAND (arg0
, 0),
6706 TREE_OPERAND (arg1
, 0))));
6712 /* Don't touch a floating-point divide by zero unless the mode
6713 of the constant can represent infinity. */
6714 if (TREE_CODE (arg1
) == REAL_CST
6715 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1
)))
6716 && real_zerop (arg1
))
6719 /* (-A) / (-B) -> A / B */
6720 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& negate_expr_p (arg1
))
6721 return fold (build (RDIV_EXPR
, type
,
6722 TREE_OPERAND (arg0
, 0),
6723 negate_expr (arg1
)));
6724 if (TREE_CODE (arg1
) == NEGATE_EXPR
&& negate_expr_p (arg0
))
6725 return fold (build (RDIV_EXPR
, type
,
6727 TREE_OPERAND (arg1
, 0)));
6729 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
6730 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
6731 && real_onep (arg1
))
6732 return non_lvalue (fold_convert (type
, arg0
));
6734 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
6735 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
6736 && real_minus_onep (arg1
))
6737 return non_lvalue (fold_convert (type
, negate_expr (arg0
)));
6739 /* If ARG1 is a constant, we can convert this to a multiply by the
6740 reciprocal. This does not have the same rounding properties,
6741 so only do this if -funsafe-math-optimizations. We can actually
6742 always safely do it if ARG1 is a power of two, but it's hard to
6743 tell if it is or not in a portable manner. */
6744 if (TREE_CODE (arg1
) == REAL_CST
)
6746 if (flag_unsafe_math_optimizations
6747 && 0 != (tem
= const_binop (code
, build_real (type
, dconst1
),
6749 return fold (build (MULT_EXPR
, type
, arg0
, tem
));
6750 /* Find the reciprocal if optimizing and the result is exact. */
6754 r
= TREE_REAL_CST (arg1
);
6755 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0
)), &r
))
6757 tem
= build_real (type
, r
);
6758 return fold (build (MULT_EXPR
, type
, arg0
, tem
));
6762 /* Convert A/B/C to A/(B*C). */
6763 if (flag_unsafe_math_optimizations
6764 && TREE_CODE (arg0
) == RDIV_EXPR
)
6765 return fold (build (RDIV_EXPR
, type
, TREE_OPERAND (arg0
, 0),
6766 fold (build (MULT_EXPR
, type
,
6767 TREE_OPERAND (arg0
, 1), arg1
))));
6769 /* Convert A/(B/C) to (A/B)*C. */
6770 if (flag_unsafe_math_optimizations
6771 && TREE_CODE (arg1
) == RDIV_EXPR
)
6772 return fold (build (MULT_EXPR
, type
,
6773 fold (build (RDIV_EXPR
, type
, arg0
,
6774 TREE_OPERAND (arg1
, 0))),
6775 TREE_OPERAND (arg1
, 1)));
6777 /* Convert C1/(X*C2) into (C1/C2)/X. */
6778 if (flag_unsafe_math_optimizations
6779 && TREE_CODE (arg1
) == MULT_EXPR
6780 && TREE_CODE (arg0
) == REAL_CST
6781 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == REAL_CST
)
6783 tree tem
= const_binop (RDIV_EXPR
, arg0
,
6784 TREE_OPERAND (arg1
, 1), 0);
6786 return fold (build (RDIV_EXPR
, type
, tem
,
6787 TREE_OPERAND (arg1
, 0)));
6790 if (flag_unsafe_math_optimizations
)
6792 enum built_in_function fcode
= builtin_mathfn_code (arg1
);
6793 /* Optimize x/expN(y) into x*expN(-y). */
6794 if (fcode
== BUILT_IN_EXP
6795 || fcode
== BUILT_IN_EXPF
6796 || fcode
== BUILT_IN_EXPL
6797 || fcode
== BUILT_IN_EXP2
6798 || fcode
== BUILT_IN_EXP2F
6799 || fcode
== BUILT_IN_EXP2L
6800 || fcode
== BUILT_IN_EXP10
6801 || fcode
== BUILT_IN_EXP10F
6802 || fcode
== BUILT_IN_EXP10L
6803 || fcode
== BUILT_IN_POW10
6804 || fcode
== BUILT_IN_POW10F
6805 || fcode
== BUILT_IN_POW10L
)
6807 tree expfn
= TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0);
6808 tree arg
= build1 (NEGATE_EXPR
, type
,
6809 TREE_VALUE (TREE_OPERAND (arg1
, 1)));
6810 tree arglist
= build_tree_list (NULL_TREE
, fold (arg
));
6811 arg1
= build_function_call_expr (expfn
, arglist
);
6812 return fold (build (MULT_EXPR
, type
, arg0
, arg1
));
6815 /* Optimize x/pow(y,z) into x*pow(y,-z). */
6816 if (fcode
== BUILT_IN_POW
6817 || fcode
== BUILT_IN_POWF
6818 || fcode
== BUILT_IN_POWL
)
6820 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0);
6821 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
6822 tree arg11
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1
, 1)));
6823 tree neg11
= fold (build1 (NEGATE_EXPR
, type
, arg11
));
6824 tree arglist
= tree_cons(NULL_TREE
, arg10
,
6825 build_tree_list (NULL_TREE
, neg11
));
6826 arg1
= build_function_call_expr (powfn
, arglist
);
6827 return fold (build (MULT_EXPR
, type
, arg0
, arg1
));
6831 if (flag_unsafe_math_optimizations
)
6833 enum built_in_function fcode0
= builtin_mathfn_code (arg0
);
6834 enum built_in_function fcode1
= builtin_mathfn_code (arg1
);
6836 /* Optimize sin(x)/cos(x) as tan(x). */
6837 if (((fcode0
== BUILT_IN_SIN
&& fcode1
== BUILT_IN_COS
)
6838 || (fcode0
== BUILT_IN_SINF
&& fcode1
== BUILT_IN_COSF
)
6839 || (fcode0
== BUILT_IN_SINL
&& fcode1
== BUILT_IN_COSL
))
6840 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0
, 1)),
6841 TREE_VALUE (TREE_OPERAND (arg1
, 1)), 0))
6845 if (fcode0
== BUILT_IN_SIN
)
6846 tanfn
= implicit_built_in_decls
[BUILT_IN_TAN
];
6847 else if (fcode0
== BUILT_IN_SINF
)
6848 tanfn
= implicit_built_in_decls
[BUILT_IN_TANF
];
6849 else if (fcode0
== BUILT_IN_SINL
)
6850 tanfn
= implicit_built_in_decls
[BUILT_IN_TANL
];
6854 if (tanfn
!= NULL_TREE
)
6855 return build_function_call_expr (tanfn
,
6856 TREE_OPERAND (arg0
, 1));
6859 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
6860 if (((fcode0
== BUILT_IN_COS
&& fcode1
== BUILT_IN_SIN
)
6861 || (fcode0
== BUILT_IN_COSF
&& fcode1
== BUILT_IN_SINF
)
6862 || (fcode0
== BUILT_IN_COSL
&& fcode1
== BUILT_IN_SINL
))
6863 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0
, 1)),
6864 TREE_VALUE (TREE_OPERAND (arg1
, 1)), 0))
6868 if (fcode0
== BUILT_IN_COS
)
6869 tanfn
= implicit_built_in_decls
[BUILT_IN_TAN
];
6870 else if (fcode0
== BUILT_IN_COSF
)
6871 tanfn
= implicit_built_in_decls
[BUILT_IN_TANF
];
6872 else if (fcode0
== BUILT_IN_COSL
)
6873 tanfn
= implicit_built_in_decls
[BUILT_IN_TANL
];
6877 if (tanfn
!= NULL_TREE
)
6879 tree tmp
= TREE_OPERAND (arg0
, 1);
6880 tmp
= build_function_call_expr (tanfn
, tmp
);
6881 return fold (build (RDIV_EXPR
, type
,
6882 build_real (type
, dconst1
),
6887 /* Optimize pow(x,c)/x as pow(x,c-1). */
6888 if (fcode0
== BUILT_IN_POW
6889 || fcode0
== BUILT_IN_POWF
6890 || fcode0
== BUILT_IN_POWL
)
6892 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
6893 tree arg01
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0
, 1)));
6894 if (TREE_CODE (arg01
) == REAL_CST
6895 && ! TREE_CONSTANT_OVERFLOW (arg01
)
6896 && operand_equal_p (arg1
, arg00
, 0))
6898 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
6902 c
= TREE_REAL_CST (arg01
);
6903 real_arithmetic (&c
, MINUS_EXPR
, &c
, &dconst1
);
6904 arg
= build_real (type
, c
);
6905 arglist
= build_tree_list (NULL_TREE
, arg
);
6906 arglist
= tree_cons (NULL_TREE
, arg1
, arglist
);
6907 return build_function_call_expr (powfn
, arglist
);
6913 case TRUNC_DIV_EXPR
:
6914 case ROUND_DIV_EXPR
:
6915 case FLOOR_DIV_EXPR
:
6917 case EXACT_DIV_EXPR
:
6918 if (integer_onep (arg1
))
6919 return non_lvalue (fold_convert (type
, arg0
));
6920 if (integer_zerop (arg1
))
6923 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
6924 operation, EXACT_DIV_EXPR.
6926 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
6927 At one time others generated faster code, it's not clear if they do
6928 after the last round to changes to the DIV code in expmed.c. */
6929 if ((code
== CEIL_DIV_EXPR
|| code
== FLOOR_DIV_EXPR
)
6930 && multiple_of_p (type
, arg0
, arg1
))
6931 return fold (build (EXACT_DIV_EXPR
, type
, arg0
, arg1
));
6933 if (TREE_CODE (arg1
) == INTEGER_CST
6934 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
6936 return fold_convert (type
, tem
);
6941 case FLOOR_MOD_EXPR
:
6942 case ROUND_MOD_EXPR
:
6943 case TRUNC_MOD_EXPR
:
6944 if (integer_onep (arg1
))
6945 return omit_one_operand (type
, integer_zero_node
, arg0
);
6946 if (integer_zerop (arg1
))
6949 if (TREE_CODE (arg1
) == INTEGER_CST
6950 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
6952 return fold_convert (type
, tem
);
6958 if (integer_all_onesp (arg0
))
6959 return omit_one_operand (type
, arg0
, arg1
);
6963 /* Optimize -1 >> x for arithmetic right shifts. */
6964 if (integer_all_onesp (arg0
) && ! TREE_UNSIGNED (type
))
6965 return omit_one_operand (type
, arg0
, arg1
);
6966 /* ... fall through ... */
6970 if (integer_zerop (arg1
))
6971 return non_lvalue (fold_convert (type
, arg0
));
6972 if (integer_zerop (arg0
))
6973 return omit_one_operand (type
, arg0
, arg1
);
6975 /* Since negative shift count is not well-defined,
6976 don't try to compute it in the compiler. */
6977 if (TREE_CODE (arg1
) == INTEGER_CST
&& tree_int_cst_sgn (arg1
) < 0)
6979 /* Rewrite an LROTATE_EXPR by a constant into an
6980 RROTATE_EXPR by a new constant. */
6981 if (code
== LROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
)
6983 tree tem
= build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type
)), 0);
6984 tem
= fold_convert (TREE_TYPE (arg1
), tem
);
6985 tem
= const_binop (MINUS_EXPR
, tem
, arg1
, 0);
6986 return fold (build (RROTATE_EXPR
, type
, arg0
, tem
));
6989 /* If we have a rotate of a bit operation with the rotate count and
6990 the second operand of the bit operation both constant,
6991 permute the two operations. */
6992 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
6993 && (TREE_CODE (arg0
) == BIT_AND_EXPR
6994 || TREE_CODE (arg0
) == BIT_IOR_EXPR
6995 || TREE_CODE (arg0
) == BIT_XOR_EXPR
)
6996 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
6997 return fold (build (TREE_CODE (arg0
), type
,
6998 fold (build (code
, type
,
6999 TREE_OPERAND (arg0
, 0), arg1
)),
7000 fold (build (code
, type
,
7001 TREE_OPERAND (arg0
, 1), arg1
))));
7003 /* Two consecutive rotates adding up to the width of the mode can
7005 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
7006 && TREE_CODE (arg0
) == RROTATE_EXPR
7007 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
7008 && TREE_INT_CST_HIGH (arg1
) == 0
7009 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0
, 1)) == 0
7010 && ((TREE_INT_CST_LOW (arg1
)
7011 + TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1)))
7012 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type
))))
7013 return TREE_OPERAND (arg0
, 0);
7018 if (operand_equal_p (arg0
, arg1
, 0))
7019 return omit_one_operand (type
, arg0
, arg1
);
7020 if (INTEGRAL_TYPE_P (type
)
7021 && operand_equal_p (arg1
, TYPE_MIN_VALUE (type
), 1))
7022 return omit_one_operand (type
, arg1
, arg0
);
7026 if (operand_equal_p (arg0
, arg1
, 0))
7027 return omit_one_operand (type
, arg0
, arg1
);
7028 if (INTEGRAL_TYPE_P (type
)
7029 && TYPE_MAX_VALUE (type
)
7030 && operand_equal_p (arg1
, TYPE_MAX_VALUE (type
), 1))
7031 return omit_one_operand (type
, arg1
, arg0
);
7034 case TRUTH_NOT_EXPR
:
7035 /* Note that the operand of this must be an int
7036 and its values must be 0 or 1.
7037 ("true" is a fixed value perhaps depending on the language,
7038 but we don't handle values other than 1 correctly yet.) */
7039 tem
= invert_truthvalue (arg0
);
7040 /* Avoid infinite recursion. */
7041 if (TREE_CODE (tem
) == TRUTH_NOT_EXPR
)
7043 tem
= fold_single_bit_test (code
, arg0
, arg1
, type
);
7048 return fold_convert (type
, tem
);
7050 case TRUTH_ANDIF_EXPR
:
7051 /* Note that the operands of this must be ints
7052 and their values must be 0 or 1.
7053 ("true" is a fixed value perhaps depending on the language.) */
7054 /* If first arg is constant zero, return it. */
7055 if (integer_zerop (arg0
))
7056 return fold_convert (type
, arg0
);
7057 case TRUTH_AND_EXPR
:
7058 /* If either arg is constant true, drop it. */
7059 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
7060 return non_lvalue (fold_convert (type
, arg1
));
7061 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
)
7062 /* Preserve sequence points. */
7063 && (code
!= TRUTH_ANDIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
7064 return non_lvalue (fold_convert (type
, arg0
));
7065 /* If second arg is constant zero, result is zero, but first arg
7066 must be evaluated. */
7067 if (integer_zerop (arg1
))
7068 return omit_one_operand (type
, arg1
, arg0
);
7069 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
7070 case will be handled here. */
7071 if (integer_zerop (arg0
))
7072 return omit_one_operand (type
, arg0
, arg1
);
7075 /* We only do these simplifications if we are optimizing. */
7079 /* Check for things like (A || B) && (A || C). We can convert this
7080 to A || (B && C). Note that either operator can be any of the four
7081 truth and/or operations and the transformation will still be
7082 valid. Also note that we only care about order for the
7083 ANDIF and ORIF operators. If B contains side effects, this
7084 might change the truth-value of A. */
7085 if (TREE_CODE (arg0
) == TREE_CODE (arg1
)
7086 && (TREE_CODE (arg0
) == TRUTH_ANDIF_EXPR
7087 || TREE_CODE (arg0
) == TRUTH_ORIF_EXPR
7088 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
7089 || TREE_CODE (arg0
) == TRUTH_OR_EXPR
)
7090 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0
, 1)))
7092 tree a00
= TREE_OPERAND (arg0
, 0);
7093 tree a01
= TREE_OPERAND (arg0
, 1);
7094 tree a10
= TREE_OPERAND (arg1
, 0);
7095 tree a11
= TREE_OPERAND (arg1
, 1);
7096 int commutative
= ((TREE_CODE (arg0
) == TRUTH_OR_EXPR
7097 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
)
7098 && (code
== TRUTH_AND_EXPR
7099 || code
== TRUTH_OR_EXPR
));
7101 if (operand_equal_p (a00
, a10
, 0))
7102 return fold (build (TREE_CODE (arg0
), type
, a00
,
7103 fold (build (code
, type
, a01
, a11
))));
7104 else if (commutative
&& operand_equal_p (a00
, a11
, 0))
7105 return fold (build (TREE_CODE (arg0
), type
, a00
,
7106 fold (build (code
, type
, a01
, a10
))));
7107 else if (commutative
&& operand_equal_p (a01
, a10
, 0))
7108 return fold (build (TREE_CODE (arg0
), type
, a01
,
7109 fold (build (code
, type
, a00
, a11
))));
7111 /* This case if tricky because we must either have commutative
7112 operators or else A10 must not have side-effects. */
7114 else if ((commutative
|| ! TREE_SIDE_EFFECTS (a10
))
7115 && operand_equal_p (a01
, a11
, 0))
7116 return fold (build (TREE_CODE (arg0
), type
,
7117 fold (build (code
, type
, a00
, a10
)),
7121 /* See if we can build a range comparison. */
7122 if (0 != (tem
= fold_range_test (t
)))
7125 /* Check for the possibility of merging component references. If our
7126 lhs is another similar operation, try to merge its rhs with our
7127 rhs. Then try to merge our lhs and rhs. */
7128 if (TREE_CODE (arg0
) == code
7129 && 0 != (tem
= fold_truthop (code
, type
,
7130 TREE_OPERAND (arg0
, 1), arg1
)))
7131 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
7133 if ((tem
= fold_truthop (code
, type
, arg0
, arg1
)) != 0)
7138 case TRUTH_ORIF_EXPR
:
7139 /* Note that the operands of this must be ints
7140 and their values must be 0 or true.
7141 ("true" is a fixed value perhaps depending on the language.) */
7142 /* If first arg is constant true, return it. */
7143 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
7144 return fold_convert (type
, arg0
);
7146 /* If either arg is constant zero, drop it. */
7147 if (TREE_CODE (arg0
) == INTEGER_CST
&& integer_zerop (arg0
))
7148 return non_lvalue (fold_convert (type
, arg1
));
7149 if (TREE_CODE (arg1
) == INTEGER_CST
&& integer_zerop (arg1
)
7150 /* Preserve sequence points. */
7151 && (code
!= TRUTH_ORIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
7152 return non_lvalue (fold_convert (type
, arg0
));
7153 /* If second arg is constant true, result is true, but we must
7154 evaluate first arg. */
7155 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
))
7156 return omit_one_operand (type
, arg1
, arg0
);
7157 /* Likewise for first arg, but note this only occurs here for
7159 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
7160 return omit_one_operand (type
, arg0
, arg1
);
7163 case TRUTH_XOR_EXPR
:
7164 /* If either arg is constant zero, drop it. */
7165 if (integer_zerop (arg0
))
7166 return non_lvalue (fold_convert (type
, arg1
));
7167 if (integer_zerop (arg1
))
7168 return non_lvalue (fold_convert (type
, arg0
));
7169 /* If either arg is constant true, this is a logical inversion. */
7170 if (integer_onep (arg0
))
7171 return non_lvalue (fold_convert (type
, invert_truthvalue (arg1
)));
7172 if (integer_onep (arg1
))
7173 return non_lvalue (fold_convert (type
, invert_truthvalue (arg0
)));
7182 /* If one arg is a real or integer constant, put it last. */
7183 if (tree_swap_operands_p (arg0
, arg1
, true))
7184 return fold (build (swap_tree_comparison (code
), type
, arg1
, arg0
));
7186 /* If this is an equality comparison of the address of a non-weak
7187 object against zero, then we know the result. */
7188 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7189 && TREE_CODE (arg0
) == ADDR_EXPR
7190 && DECL_P (TREE_OPERAND (arg0
, 0))
7191 && ! DECL_WEAK (TREE_OPERAND (arg0
, 0))
7192 && integer_zerop (arg1
))
7194 if (code
== EQ_EXPR
)
7195 return integer_zero_node
;
7197 return integer_one_node
;
7200 /* If this is an equality comparison of the address of two non-weak,
7201 unaliased symbols neither of which are extern (since we do not
7202 have access to attributes for externs), then we know the result. */
7203 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7204 && TREE_CODE (arg0
) == ADDR_EXPR
7205 && DECL_P (TREE_OPERAND (arg0
, 0))
7206 && ! DECL_WEAK (TREE_OPERAND (arg0
, 0))
7207 && ! lookup_attribute ("alias",
7208 DECL_ATTRIBUTES (TREE_OPERAND (arg0
, 0)))
7209 && ! DECL_EXTERNAL (TREE_OPERAND (arg0
, 0))
7210 && TREE_CODE (arg1
) == ADDR_EXPR
7211 && DECL_P (TREE_OPERAND (arg1
, 0))
7212 && ! DECL_WEAK (TREE_OPERAND (arg1
, 0))
7213 && ! lookup_attribute ("alias",
7214 DECL_ATTRIBUTES (TREE_OPERAND (arg1
, 0)))
7215 && ! DECL_EXTERNAL (TREE_OPERAND (arg1
, 0)))
7217 if (code
== EQ_EXPR
)
7218 return (operand_equal_p (arg0
, arg1
, 0)
7219 ? integer_one_node
: integer_zero_node
);
7221 return (operand_equal_p (arg0
, arg1
, 0)
7222 ? integer_zero_node
: integer_one_node
);
7225 if (FLOAT_TYPE_P (TREE_TYPE (arg0
)))
7227 tree targ0
= strip_float_extensions (arg0
);
7228 tree targ1
= strip_float_extensions (arg1
);
7229 tree newtype
= TREE_TYPE (targ0
);
7231 if (TYPE_PRECISION (TREE_TYPE (targ1
)) > TYPE_PRECISION (newtype
))
7232 newtype
= TREE_TYPE (targ1
);
7234 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
7235 if (TYPE_PRECISION (newtype
) < TYPE_PRECISION (TREE_TYPE (arg0
)))
7236 return fold (build (code
, type
, fold_convert (newtype
, targ0
),
7237 fold_convert (newtype
, targ1
)));
7239 /* (-a) CMP (-b) -> b CMP a */
7240 if (TREE_CODE (arg0
) == NEGATE_EXPR
7241 && TREE_CODE (arg1
) == NEGATE_EXPR
)
7242 return fold (build (code
, type
, TREE_OPERAND (arg1
, 0),
7243 TREE_OPERAND (arg0
, 0)));
7245 if (TREE_CODE (arg1
) == REAL_CST
)
7247 REAL_VALUE_TYPE cst
;
7248 cst
= TREE_REAL_CST (arg1
);
7250 /* (-a) CMP CST -> a swap(CMP) (-CST) */
7251 if (TREE_CODE (arg0
) == NEGATE_EXPR
)
7253 fold (build (swap_tree_comparison (code
), type
,
7254 TREE_OPERAND (arg0
, 0),
7255 build_real (TREE_TYPE (arg1
),
7256 REAL_VALUE_NEGATE (cst
))));
7258 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
7259 /* a CMP (-0) -> a CMP 0 */
7260 if (REAL_VALUE_MINUS_ZERO (cst
))
7261 return fold (build (code
, type
, arg0
,
7262 build_real (TREE_TYPE (arg1
), dconst0
)));
7264 /* x != NaN is always true, other ops are always false. */
7265 if (REAL_VALUE_ISNAN (cst
)
7266 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1
))))
7268 t
= (code
== NE_EXPR
) ? integer_one_node
: integer_zero_node
;
7269 return omit_one_operand (type
, fold_convert (type
, t
), arg0
);
7272 /* Fold comparisons against infinity. */
7273 if (REAL_VALUE_ISINF (cst
))
7275 tem
= fold_inf_compare (code
, type
, arg0
, arg1
);
7276 if (tem
!= NULL_TREE
)
7281 /* If this is a comparison of a real constant with a PLUS_EXPR
7282 or a MINUS_EXPR of a real constant, we can convert it into a
7283 comparison with a revised real constant as long as no overflow
7284 occurs when unsafe_math_optimizations are enabled. */
7285 if (flag_unsafe_math_optimizations
7286 && TREE_CODE (arg1
) == REAL_CST
7287 && (TREE_CODE (arg0
) == PLUS_EXPR
7288 || TREE_CODE (arg0
) == MINUS_EXPR
)
7289 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == REAL_CST
7290 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
7291 ? MINUS_EXPR
: PLUS_EXPR
,
7292 arg1
, TREE_OPERAND (arg0
, 1), 0))
7293 && ! TREE_CONSTANT_OVERFLOW (tem
))
7294 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
7296 /* Likewise, we can simplify a comparison of a real constant with
7297 a MINUS_EXPR whose first operand is also a real constant, i.e.
7298 (c1 - x) < c2 becomes x > c1-c2. */
7299 if (flag_unsafe_math_optimizations
7300 && TREE_CODE (arg1
) == REAL_CST
7301 && TREE_CODE (arg0
) == MINUS_EXPR
7302 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == REAL_CST
7303 && 0 != (tem
= const_binop (MINUS_EXPR
, TREE_OPERAND (arg0
, 0),
7305 && ! TREE_CONSTANT_OVERFLOW (tem
))
7306 return fold (build (swap_tree_comparison (code
), type
,
7307 TREE_OPERAND (arg0
, 1), tem
));
7309 /* Fold comparisons against built-in math functions. */
7310 if (TREE_CODE (arg1
) == REAL_CST
7311 && flag_unsafe_math_optimizations
7312 && ! flag_errno_math
)
7314 enum built_in_function fcode
= builtin_mathfn_code (arg0
);
7316 if (fcode
!= END_BUILTINS
)
7318 tem
= fold_mathfn_compare (fcode
, code
, type
, arg0
, arg1
);
7319 if (tem
!= NULL_TREE
)
7325 /* Convert foo++ == CONST into ++foo == CONST + INCR.
7326 First, see if one arg is constant; find the constant arg
7327 and the other one. */
7329 tree constop
= 0, varop
= NULL_TREE
;
7330 int constopnum
= -1;
7332 if (TREE_CONSTANT (arg1
))
7333 constopnum
= 1, constop
= arg1
, varop
= arg0
;
7334 if (TREE_CONSTANT (arg0
))
7335 constopnum
= 0, constop
= arg0
, varop
= arg1
;
7337 if (constop
&& TREE_CODE (varop
) == POSTINCREMENT_EXPR
)
7339 /* This optimization is invalid for ordered comparisons
7340 if CONST+INCR overflows or if foo+incr might overflow.
7341 This optimization is invalid for floating point due to rounding.
7342 For pointer types we assume overflow doesn't happen. */
7343 if (POINTER_TYPE_P (TREE_TYPE (varop
))
7344 || (! FLOAT_TYPE_P (TREE_TYPE (varop
))
7345 && (code
== EQ_EXPR
|| code
== NE_EXPR
)))
7348 = fold (build (PLUS_EXPR
, TREE_TYPE (varop
),
7349 constop
, TREE_OPERAND (varop
, 1)));
7351 /* Do not overwrite the current varop to be a preincrement,
7352 create a new node so that we won't confuse our caller who
7353 might create trees and throw them away, reusing the
7354 arguments that they passed to build. This shows up in
7355 the THEN or ELSE parts of ?: being postincrements. */
7356 varop
= build (PREINCREMENT_EXPR
, TREE_TYPE (varop
),
7357 TREE_OPERAND (varop
, 0),
7358 TREE_OPERAND (varop
, 1));
7360 /* If VAROP is a reference to a bitfield, we must mask
7361 the constant by the width of the field. */
7362 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
7363 && DECL_BIT_FIELD(TREE_OPERAND
7364 (TREE_OPERAND (varop
, 0), 1)))
7367 = TREE_INT_CST_LOW (DECL_SIZE
7369 (TREE_OPERAND (varop
, 0), 1)));
7370 tree mask
, unsigned_type
;
7371 unsigned int precision
;
7372 tree folded_compare
;
7374 /* First check whether the comparison would come out
7375 always the same. If we don't do that we would
7376 change the meaning with the masking. */
7377 if (constopnum
== 0)
7378 folded_compare
= fold (build (code
, type
, constop
,
7379 TREE_OPERAND (varop
, 0)));
7381 folded_compare
= fold (build (code
, type
,
7382 TREE_OPERAND (varop
, 0),
7384 if (integer_zerop (folded_compare
)
7385 || integer_onep (folded_compare
))
7386 return omit_one_operand (type
, folded_compare
, varop
);
7388 unsigned_type
= (*lang_hooks
.types
.type_for_size
)(size
, 1);
7389 precision
= TYPE_PRECISION (unsigned_type
);
7390 mask
= build_int_2 (~0, ~0);
7391 TREE_TYPE (mask
) = unsigned_type
;
7392 force_fit_type (mask
, 0);
7393 mask
= const_binop (RSHIFT_EXPR
, mask
,
7394 size_int (precision
- size
), 0);
7395 newconst
= fold (build (BIT_AND_EXPR
,
7396 TREE_TYPE (varop
), newconst
,
7397 fold_convert (TREE_TYPE (varop
),
7401 t
= build (code
, type
,
7402 (constopnum
== 0) ? newconst
: varop
,
7403 (constopnum
== 1) ? newconst
: varop
);
7407 else if (constop
&& TREE_CODE (varop
) == POSTDECREMENT_EXPR
)
7409 if (POINTER_TYPE_P (TREE_TYPE (varop
))
7410 || (! FLOAT_TYPE_P (TREE_TYPE (varop
))
7411 && (code
== EQ_EXPR
|| code
== NE_EXPR
)))
7414 = fold (build (MINUS_EXPR
, TREE_TYPE (varop
),
7415 constop
, TREE_OPERAND (varop
, 1)));
7417 /* Do not overwrite the current varop to be a predecrement,
7418 create a new node so that we won't confuse our caller who
7419 might create trees and throw them away, reusing the
7420 arguments that they passed to build. This shows up in
7421 the THEN or ELSE parts of ?: being postdecrements. */
7422 varop
= build (PREDECREMENT_EXPR
, TREE_TYPE (varop
),
7423 TREE_OPERAND (varop
, 0),
7424 TREE_OPERAND (varop
, 1));
7426 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
7427 && DECL_BIT_FIELD(TREE_OPERAND
7428 (TREE_OPERAND (varop
, 0), 1)))
7431 = TREE_INT_CST_LOW (DECL_SIZE
7433 (TREE_OPERAND (varop
, 0), 1)));
7434 tree mask
, unsigned_type
;
7435 unsigned int precision
;
7436 tree folded_compare
;
7438 if (constopnum
== 0)
7439 folded_compare
= fold (build (code
, type
, constop
,
7440 TREE_OPERAND (varop
, 0)));
7442 folded_compare
= fold (build (code
, type
,
7443 TREE_OPERAND (varop
, 0),
7445 if (integer_zerop (folded_compare
)
7446 || integer_onep (folded_compare
))
7447 return omit_one_operand (type
, folded_compare
, varop
);
7449 unsigned_type
= (*lang_hooks
.types
.type_for_size
)(size
, 1);
7450 precision
= TYPE_PRECISION (unsigned_type
);
7451 mask
= build_int_2 (~0, ~0);
7452 TREE_TYPE (mask
) = TREE_TYPE (varop
);
7453 force_fit_type (mask
, 0);
7454 mask
= const_binop (RSHIFT_EXPR
, mask
,
7455 size_int (precision
- size
), 0);
7456 newconst
= fold (build (BIT_AND_EXPR
,
7457 TREE_TYPE (varop
), newconst
,
7458 fold_convert (TREE_TYPE (varop
),
7462 t
= build (code
, type
,
7463 (constopnum
== 0) ? newconst
: varop
,
7464 (constopnum
== 1) ? newconst
: varop
);
7470 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
7471 This transformation affects the cases which are handled in later
7472 optimizations involving comparisons with non-negative constants. */
7473 if (TREE_CODE (arg1
) == INTEGER_CST
7474 && TREE_CODE (arg0
) != INTEGER_CST
7475 && tree_int_cst_sgn (arg1
) > 0)
7480 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
7481 return fold (build (GT_EXPR
, type
, arg0
, arg1
));
7484 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
7485 return fold (build (LE_EXPR
, type
, arg0
, arg1
));
7492 /* Comparisons with the highest or lowest possible integer of
7493 the specified size will have known values. */
7495 int width
= GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1
)));
7497 if (TREE_CODE (arg1
) == INTEGER_CST
7498 && ! TREE_CONSTANT_OVERFLOW (arg1
)
7499 && width
<= HOST_BITS_PER_WIDE_INT
7500 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
7501 || POINTER_TYPE_P (TREE_TYPE (arg1
))))
7503 unsigned HOST_WIDE_INT signed_max
;
7504 unsigned HOST_WIDE_INT max
, min
;
7506 signed_max
= ((unsigned HOST_WIDE_INT
) 1 << (width
- 1)) - 1;
7508 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
7510 max
= ((unsigned HOST_WIDE_INT
) 2 << (width
- 1)) - 1;
7516 min
= ((unsigned HOST_WIDE_INT
) -1 << (width
- 1));
7519 if (TREE_INT_CST_HIGH (arg1
) == 0
7520 && TREE_INT_CST_LOW (arg1
) == max
)
7524 return omit_one_operand (type
,
7529 return fold (build (EQ_EXPR
, type
, arg0
, arg1
));
7532 return omit_one_operand (type
,
7537 return fold (build (NE_EXPR
, type
, arg0
, arg1
));
7539 /* The GE_EXPR and LT_EXPR cases above are not normally
7540 reached because of previous transformations. */
7545 else if (TREE_INT_CST_HIGH (arg1
) == 0
7546 && TREE_INT_CST_LOW (arg1
) == max
- 1)
7550 arg1
= const_binop (PLUS_EXPR
, arg1
, integer_one_node
, 0);
7551 return fold (build (EQ_EXPR
, type
, arg0
, arg1
));
7553 arg1
= const_binop (PLUS_EXPR
, arg1
, integer_one_node
, 0);
7554 return fold (build (NE_EXPR
, type
, arg0
, arg1
));
7558 else if (TREE_INT_CST_HIGH (arg1
) == (min
? -1 : 0)
7559 && TREE_INT_CST_LOW (arg1
) == min
)
7563 return omit_one_operand (type
,
7568 return fold (build (EQ_EXPR
, type
, arg0
, arg1
));
7571 return omit_one_operand (type
,
7576 return fold (build (NE_EXPR
, type
, arg0
, arg1
));
7581 else if (TREE_INT_CST_HIGH (arg1
) == (min
? -1 : 0)
7582 && TREE_INT_CST_LOW (arg1
) == min
+ 1)
7586 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
7587 return fold (build (NE_EXPR
, type
, arg0
, arg1
));
7589 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
7590 return fold (build (EQ_EXPR
, type
, arg0
, arg1
));
7595 else if (TREE_INT_CST_HIGH (arg1
) == 0
7596 && TREE_INT_CST_LOW (arg1
) == signed_max
7597 && TREE_UNSIGNED (TREE_TYPE (arg1
))
7598 /* signed_type does not work on pointer types. */
7599 && INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
7601 /* The following case also applies to X < signed_max+1
7602 and X >= signed_max+1 because previous transformations. */
7603 if (code
== LE_EXPR
|| code
== GT_EXPR
)
7606 st0
= (*lang_hooks
.types
.signed_type
) (TREE_TYPE (arg0
));
7607 st1
= (*lang_hooks
.types
.signed_type
) (TREE_TYPE (arg1
));
7609 (build (code
== LE_EXPR
? GE_EXPR
: LT_EXPR
,
7610 type
, fold_convert (st0
, arg0
),
7611 fold_convert (st1
, integer_zero_node
)));
7617 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
7618 a MINUS_EXPR of a constant, we can convert it into a comparison with
7619 a revised constant as long as no overflow occurs. */
7620 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7621 && TREE_CODE (arg1
) == INTEGER_CST
7622 && (TREE_CODE (arg0
) == PLUS_EXPR
7623 || TREE_CODE (arg0
) == MINUS_EXPR
)
7624 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
7625 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
7626 ? MINUS_EXPR
: PLUS_EXPR
,
7627 arg1
, TREE_OPERAND (arg0
, 1), 0))
7628 && ! TREE_CONSTANT_OVERFLOW (tem
))
7629 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
7631 /* Similarly for a NEGATE_EXPR. */
7632 else if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7633 && TREE_CODE (arg0
) == NEGATE_EXPR
7634 && TREE_CODE (arg1
) == INTEGER_CST
7635 && 0 != (tem
= negate_expr (arg1
))
7636 && TREE_CODE (tem
) == INTEGER_CST
7637 && ! TREE_CONSTANT_OVERFLOW (tem
))
7638 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
7640 /* If we have X - Y == 0, we can convert that to X == Y and similarly
7641 for !=. Don't do this for ordered comparisons due to overflow. */
7642 else if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
7643 && integer_zerop (arg1
) && TREE_CODE (arg0
) == MINUS_EXPR
)
7644 return fold (build (code
, type
,
7645 TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg0
, 1)));
7647 /* If we are widening one operand of an integer comparison,
7648 see if the other operand is similarly being widened. Perhaps we
7649 can do the comparison in the narrower type. */
7650 else if (TREE_CODE (TREE_TYPE (arg0
)) == INTEGER_TYPE
7651 && TREE_CODE (arg0
) == NOP_EXPR
7652 && (tem
= get_unwidened (arg0
, NULL_TREE
)) != arg0
7653 && (t1
= get_unwidened (arg1
, TREE_TYPE (tem
))) != 0
7654 && (TREE_TYPE (t1
) == TREE_TYPE (tem
)
7655 || (TREE_CODE (t1
) == INTEGER_CST
7656 && int_fits_type_p (t1
, TREE_TYPE (tem
)))))
7657 return fold (build (code
, type
, tem
,
7658 fold_convert (TREE_TYPE (tem
), t1
)));
7660 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
7661 constant, we can simplify it. */
7662 else if (TREE_CODE (arg1
) == INTEGER_CST
7663 && (TREE_CODE (arg0
) == MIN_EXPR
7664 || TREE_CODE (arg0
) == MAX_EXPR
)
7665 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
7666 return optimize_minmax_comparison (t
);
7668 /* If we are comparing an ABS_EXPR with a constant, we can
7669 convert all the cases into explicit comparisons, but they may
7670 well not be faster than doing the ABS and one comparison.
7671 But ABS (X) <= C is a range comparison, which becomes a subtraction
7672 and a comparison, and is probably faster. */
7673 else if (code
== LE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
7674 && TREE_CODE (arg0
) == ABS_EXPR
7675 && ! TREE_SIDE_EFFECTS (arg0
)
7676 && (0 != (tem
= negate_expr (arg1
)))
7677 && TREE_CODE (tem
) == INTEGER_CST
7678 && ! TREE_CONSTANT_OVERFLOW (tem
))
7679 return fold (build (TRUTH_ANDIF_EXPR
, type
,
7680 build (GE_EXPR
, type
, TREE_OPERAND (arg0
, 0), tem
),
7681 build (LE_EXPR
, type
,
7682 TREE_OPERAND (arg0
, 0), arg1
)));
7684 /* If this is an EQ or NE comparison with zero and ARG0 is
7685 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
7686 two operations, but the latter can be done in one less insn
7687 on machines that have only two-operand insns or on which a
7688 constant cannot be the first operand. */
7689 if (integer_zerop (arg1
) && (code
== EQ_EXPR
|| code
== NE_EXPR
)
7690 && TREE_CODE (arg0
) == BIT_AND_EXPR
)
7692 if (TREE_CODE (TREE_OPERAND (arg0
, 0)) == LSHIFT_EXPR
7693 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0)))
7695 fold (build (code
, type
,
7696 build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
7698 TREE_TYPE (TREE_OPERAND (arg0
, 0)),
7699 TREE_OPERAND (arg0
, 1),
7700 TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1)),
7701 fold_convert (TREE_TYPE (arg0
),
7704 else if (TREE_CODE (TREE_OPERAND (arg0
, 1)) == LSHIFT_EXPR
7705 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 1), 0)))
7707 fold (build (code
, type
,
7708 build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
7710 TREE_TYPE (TREE_OPERAND (arg0
, 1)),
7711 TREE_OPERAND (arg0
, 0),
7712 TREE_OPERAND (TREE_OPERAND (arg0
, 1), 1)),
7713 fold_convert (TREE_TYPE (arg0
),
7718 /* If this is an NE or EQ comparison of zero against the result of a
7719 signed MOD operation whose second operand is a power of 2, make
7720 the MOD operation unsigned since it is simpler and equivalent. */
7721 if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
7722 && integer_zerop (arg1
)
7723 && ! TREE_UNSIGNED (TREE_TYPE (arg0
))
7724 && (TREE_CODE (arg0
) == TRUNC_MOD_EXPR
7725 || TREE_CODE (arg0
) == CEIL_MOD_EXPR
7726 || TREE_CODE (arg0
) == FLOOR_MOD_EXPR
7727 || TREE_CODE (arg0
) == ROUND_MOD_EXPR
)
7728 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
7730 tree newtype
= (*lang_hooks
.types
.unsigned_type
) (TREE_TYPE (arg0
));
7731 tree newmod
= build (TREE_CODE (arg0
), newtype
,
7732 fold_convert (newtype
,
7733 TREE_OPERAND (arg0
, 0)),
7734 fold_convert (newtype
,
7735 TREE_OPERAND (arg0
, 1)));
7737 return build (code
, type
, newmod
, fold_convert (newtype
, arg1
));
7740 /* If this is an NE comparison of zero with an AND of one, remove the
7741 comparison since the AND will give the correct value. */
7742 if (code
== NE_EXPR
&& integer_zerop (arg1
)
7743 && TREE_CODE (arg0
) == BIT_AND_EXPR
7744 && integer_onep (TREE_OPERAND (arg0
, 1)))
7745 return fold_convert (type
, arg0
);
7747 /* If we have (A & C) == C where C is a power of 2, convert this into
7748 (A & C) != 0. Similarly for NE_EXPR. */
7749 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7750 && TREE_CODE (arg0
) == BIT_AND_EXPR
7751 && integer_pow2p (TREE_OPERAND (arg0
, 1))
7752 && operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
7753 return fold (build (code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
, type
,
7754 arg0
, integer_zero_node
));
7756 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
7757 2, then fold the expression into shifts and logical operations. */
7758 tem
= fold_single_bit_test (code
, arg0
, arg1
, type
);
7762 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
7763 Similarly for NE_EXPR. */
7764 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7765 && TREE_CODE (arg0
) == BIT_AND_EXPR
7766 && TREE_CODE (arg1
) == INTEGER_CST
7767 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
7770 = fold (build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
7771 arg1
, build1 (BIT_NOT_EXPR
,
7772 TREE_TYPE (TREE_OPERAND (arg0
, 1)),
7773 TREE_OPERAND (arg0
, 1))));
7774 tree rslt
= code
== EQ_EXPR
? integer_zero_node
: integer_one_node
;
7775 if (integer_nonzerop (dandnotc
))
7776 return omit_one_operand (type
, rslt
, arg0
);
7779 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
7780 Similarly for NE_EXPR. */
7781 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7782 && TREE_CODE (arg0
) == BIT_IOR_EXPR
7783 && TREE_CODE (arg1
) == INTEGER_CST
7784 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
7787 = fold (build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
7788 TREE_OPERAND (arg0
, 1),
7789 build1 (BIT_NOT_EXPR
, TREE_TYPE (arg1
), arg1
)));
7790 tree rslt
= code
== EQ_EXPR
? integer_zero_node
: integer_one_node
;
7791 if (integer_nonzerop (candnotd
))
7792 return omit_one_operand (type
, rslt
, arg0
);
7795 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
7796 and similarly for >= into !=. */
7797 if ((code
== LT_EXPR
|| code
== GE_EXPR
)
7798 && TREE_UNSIGNED (TREE_TYPE (arg0
))
7799 && TREE_CODE (arg1
) == LSHIFT_EXPR
7800 && integer_onep (TREE_OPERAND (arg1
, 0)))
7801 return build (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
7802 build (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
7803 TREE_OPERAND (arg1
, 1)),
7804 fold_convert (TREE_TYPE (arg0
), integer_zero_node
));
7806 else if ((code
== LT_EXPR
|| code
== GE_EXPR
)
7807 && TREE_UNSIGNED (TREE_TYPE (arg0
))
7808 && (TREE_CODE (arg1
) == NOP_EXPR
7809 || TREE_CODE (arg1
) == CONVERT_EXPR
)
7810 && TREE_CODE (TREE_OPERAND (arg1
, 0)) == LSHIFT_EXPR
7811 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0)))
7813 build (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
7814 fold_convert (TREE_TYPE (arg0
),
7815 build (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
7816 TREE_OPERAND (TREE_OPERAND (arg1
, 0),
7818 fold_convert (TREE_TYPE (arg0
), integer_zero_node
));
7820 /* Simplify comparison of something with itself. (For IEEE
7821 floating-point, we can only do some of these simplifications.) */
7822 if (operand_equal_p (arg0
, arg1
, 0))
7827 if (! FLOAT_TYPE_P (TREE_TYPE (arg0
))
7828 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
))))
7829 return constant_boolean_node (1, type
);
7834 if (! FLOAT_TYPE_P (TREE_TYPE (arg0
))
7835 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
))))
7836 return constant_boolean_node (1, type
);
7837 return fold (build (EQ_EXPR
, type
, arg0
, arg1
));
7840 /* For NE, we can only do this simplification if integer
7841 or we don't honor IEEE floating point NaNs. */
7842 if (FLOAT_TYPE_P (TREE_TYPE (arg0
))
7843 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
))))
7845 /* ... fall through ... */
7848 return constant_boolean_node (0, type
);
7854 /* If we are comparing an expression that just has comparisons
7855 of two integer values, arithmetic expressions of those comparisons,
7856 and constants, we can simplify it. There are only three cases
7857 to check: the two values can either be equal, the first can be
7858 greater, or the second can be greater. Fold the expression for
7859 those three values. Since each value must be 0 or 1, we have
7860 eight possibilities, each of which corresponds to the constant 0
7861 or 1 or one of the six possible comparisons.
7863 This handles common cases like (a > b) == 0 but also handles
7864 expressions like ((x > y) - (y > x)) > 0, which supposedly
7865 occur in macroized code. */
7867 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) != INTEGER_CST
)
7869 tree cval1
= 0, cval2
= 0;
7872 if (twoval_comparison_p (arg0
, &cval1
, &cval2
, &save_p
)
7873 /* Don't handle degenerate cases here; they should already
7874 have been handled anyway. */
7875 && cval1
!= 0 && cval2
!= 0
7876 && ! (TREE_CONSTANT (cval1
) && TREE_CONSTANT (cval2
))
7877 && TREE_TYPE (cval1
) == TREE_TYPE (cval2
)
7878 && INTEGRAL_TYPE_P (TREE_TYPE (cval1
))
7879 && TYPE_MAX_VALUE (TREE_TYPE (cval1
))
7880 && TYPE_MAX_VALUE (TREE_TYPE (cval2
))
7881 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1
)),
7882 TYPE_MAX_VALUE (TREE_TYPE (cval2
)), 0))
7884 tree maxval
= TYPE_MAX_VALUE (TREE_TYPE (cval1
));
7885 tree minval
= TYPE_MIN_VALUE (TREE_TYPE (cval1
));
7887 /* We can't just pass T to eval_subst in case cval1 or cval2
7888 was the same as ARG1. */
7891 = fold (build (code
, type
,
7892 eval_subst (arg0
, cval1
, maxval
, cval2
, minval
),
7895 = fold (build (code
, type
,
7896 eval_subst (arg0
, cval1
, maxval
, cval2
, maxval
),
7899 = fold (build (code
, type
,
7900 eval_subst (arg0
, cval1
, minval
, cval2
, maxval
),
7903 /* All three of these results should be 0 or 1. Confirm they
7904 are. Then use those values to select the proper code
7907 if ((integer_zerop (high_result
)
7908 || integer_onep (high_result
))
7909 && (integer_zerop (equal_result
)
7910 || integer_onep (equal_result
))
7911 && (integer_zerop (low_result
)
7912 || integer_onep (low_result
)))
7914 /* Make a 3-bit mask with the high-order bit being the
7915 value for `>', the next for '=', and the low for '<'. */
7916 switch ((integer_onep (high_result
) * 4)
7917 + (integer_onep (equal_result
) * 2)
7918 + integer_onep (low_result
))
7922 return omit_one_operand (type
, integer_zero_node
, arg0
);
7943 return omit_one_operand (type
, integer_one_node
, arg0
);
7946 t
= build (code
, type
, cval1
, cval2
);
7948 return save_expr (t
);
7955 /* If this is a comparison of a field, we may be able to simplify it. */
7956 if (((TREE_CODE (arg0
) == COMPONENT_REF
7957 && (*lang_hooks
.can_use_bit_fields_p
) ())
7958 || TREE_CODE (arg0
) == BIT_FIELD_REF
)
7959 && (code
== EQ_EXPR
|| code
== NE_EXPR
)
7960 /* Handle the constant case even without -O
7961 to make sure the warnings are given. */
7962 && (optimize
|| TREE_CODE (arg1
) == INTEGER_CST
))
7964 t1
= optimize_bit_field_compare (code
, type
, arg0
, arg1
);
7969 /* If this is a comparison of complex values and either or both sides
7970 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
7971 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
7972 This may prevent needless evaluations. */
7973 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7974 && TREE_CODE (TREE_TYPE (arg0
)) == COMPLEX_TYPE
7975 && (TREE_CODE (arg0
) == COMPLEX_EXPR
7976 || TREE_CODE (arg1
) == COMPLEX_EXPR
7977 || TREE_CODE (arg0
) == COMPLEX_CST
7978 || TREE_CODE (arg1
) == COMPLEX_CST
))
7980 tree subtype
= TREE_TYPE (TREE_TYPE (arg0
));
7981 tree real0
, imag0
, real1
, imag1
;
7983 arg0
= save_expr (arg0
);
7984 arg1
= save_expr (arg1
);
7985 real0
= fold (build1 (REALPART_EXPR
, subtype
, arg0
));
7986 imag0
= fold (build1 (IMAGPART_EXPR
, subtype
, arg0
));
7987 real1
= fold (build1 (REALPART_EXPR
, subtype
, arg1
));
7988 imag1
= fold (build1 (IMAGPART_EXPR
, subtype
, arg1
));
7990 return fold (build ((code
== EQ_EXPR
? TRUTH_ANDIF_EXPR
7993 fold (build (code
, type
, real0
, real1
)),
7994 fold (build (code
, type
, imag0
, imag1
))));
7997 /* Optimize comparisons of strlen vs zero to a compare of the
7998 first character of the string vs zero. To wit,
7999 strlen(ptr) == 0 => *ptr == 0
8000 strlen(ptr) != 0 => *ptr != 0
8001 Other cases should reduce to one of these two (or a constant)
8002 due to the return value of strlen being unsigned. */
8003 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
8004 && integer_zerop (arg1
)
8005 && TREE_CODE (arg0
) == CALL_EXPR
)
8007 tree fndecl
= get_callee_fndecl (arg0
);
8011 && DECL_BUILT_IN (fndecl
)
8012 && DECL_BUILT_IN_CLASS (fndecl
) != BUILT_IN_MD
8013 && DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STRLEN
8014 && (arglist
= TREE_OPERAND (arg0
, 1))
8015 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist
))) == POINTER_TYPE
8016 && ! TREE_CHAIN (arglist
))
8017 return fold (build (code
, type
,
8018 build1 (INDIRECT_REF
, char_type_node
,
8019 TREE_VALUE(arglist
)),
8020 integer_zero_node
));
8023 /* From here on, the only cases we handle are when the result is
8024 known to be a constant.
8026 To compute GT, swap the arguments and do LT.
8027 To compute GE, do LT and invert the result.
8028 To compute LE, swap the arguments, do LT and invert the result.
8029 To compute NE, do EQ and invert the result.
8031 Therefore, the code below must handle only EQ and LT. */
8033 if (code
== LE_EXPR
|| code
== GT_EXPR
)
8035 tem
= arg0
, arg0
= arg1
, arg1
= tem
;
8036 code
= swap_tree_comparison (code
);
8039 /* Note that it is safe to invert for real values here because we
8040 will check below in the one case that it matters. */
8044 if (code
== NE_EXPR
|| code
== GE_EXPR
)
8047 code
= invert_tree_comparison (code
);
8050 /* Compute a result for LT or EQ if args permit;
8051 otherwise return T. */
8052 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
8054 if (code
== EQ_EXPR
)
8055 t1
= build_int_2 (tree_int_cst_equal (arg0
, arg1
), 0);
8057 t1
= build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0
))
8058 ? INT_CST_LT_UNSIGNED (arg0
, arg1
)
8059 : INT_CST_LT (arg0
, arg1
)),
8063 #if 0 /* This is no longer useful, but breaks some real code. */
8064 /* Assume a nonexplicit constant cannot equal an explicit one,
8065 since such code would be undefined anyway.
8066 Exception: on sysvr4, using #pragma weak,
8067 a label can come out as 0. */
8068 else if (TREE_CODE (arg1
) == INTEGER_CST
8069 && !integer_zerop (arg1
)
8070 && TREE_CONSTANT (arg0
)
8071 && TREE_CODE (arg0
) == ADDR_EXPR
8073 t1
= build_int_2 (0, 0);
8075 /* Two real constants can be compared explicitly. */
8076 else if (TREE_CODE (arg0
) == REAL_CST
&& TREE_CODE (arg1
) == REAL_CST
)
8078 /* If either operand is a NaN, the result is false with two
8079 exceptions: First, an NE_EXPR is true on NaNs, but that case
8080 is already handled correctly since we will be inverting the
8081 result for NE_EXPR. Second, if we had inverted a LE_EXPR
8082 or a GE_EXPR into a LT_EXPR, we must return true so that it
8083 will be inverted into false. */
8085 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0
))
8086 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
8087 t1
= build_int_2 (invert
&& code
== LT_EXPR
, 0);
8089 else if (code
== EQ_EXPR
)
8090 t1
= build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0
),
8091 TREE_REAL_CST (arg1
)),
8094 t1
= build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0
),
8095 TREE_REAL_CST (arg1
)),
8099 if (t1
== NULL_TREE
)
8103 TREE_INT_CST_LOW (t1
) ^= 1;
8105 TREE_TYPE (t1
) = type
;
8106 if (TREE_CODE (type
) == BOOLEAN_TYPE
)
8107 return (*lang_hooks
.truthvalue_conversion
) (t1
);
8111 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
8112 so all simple results must be passed through pedantic_non_lvalue. */
8113 if (TREE_CODE (arg0
) == INTEGER_CST
)
8115 tem
= TREE_OPERAND (t
, (integer_zerop (arg0
) ? 2 : 1));
8116 /* Only optimize constant conditions when the selected branch
8117 has the same type as the COND_EXPR. This avoids optimizing
8118 away "c ? x : throw", where the throw has a void type. */
8119 if (! VOID_TYPE_P (TREE_TYPE (tem
))
8120 || VOID_TYPE_P (TREE_TYPE (t
)))
8121 return pedantic_non_lvalue (tem
);
8124 if (operand_equal_p (arg1
, TREE_OPERAND (expr
, 2), 0))
8125 return pedantic_omit_one_operand (type
, arg1
, arg0
);
8127 /* If we have A op B ? A : C, we may be able to convert this to a
8128 simpler expression, depending on the operation and the values
8129 of B and C. Signed zeros prevent all of these transformations,
8130 for reasons given above each one. */
8132 if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
8133 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
8134 arg1
, TREE_OPERAND (arg0
, 1))
8135 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1
))))
8137 tree arg2
= TREE_OPERAND (t
, 2);
8138 enum tree_code comp_code
= TREE_CODE (arg0
);
8142 /* If we have A op 0 ? A : -A, consider applying the following
8145 A == 0? A : -A same as -A
8146 A != 0? A : -A same as A
8147 A >= 0? A : -A same as abs (A)
8148 A > 0? A : -A same as abs (A)
8149 A <= 0? A : -A same as -abs (A)
8150 A < 0? A : -A same as -abs (A)
8152 None of these transformations work for modes with signed
8153 zeros. If A is +/-0, the first two transformations will
8154 change the sign of the result (from +0 to -0, or vice
8155 versa). The last four will fix the sign of the result,
8156 even though the original expressions could be positive or
8157 negative, depending on the sign of A.
8159 Note that all these transformations are correct if A is
8160 NaN, since the two alternatives (A and -A) are also NaNs. */
8161 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0
, 1)))
8162 ? real_zerop (TREE_OPERAND (arg0
, 1))
8163 : integer_zerop (TREE_OPERAND (arg0
, 1)))
8164 && TREE_CODE (arg2
) == NEGATE_EXPR
8165 && operand_equal_p (TREE_OPERAND (arg2
, 0), arg1
, 0))
8169 tem
= fold_convert (TREE_TYPE (TREE_OPERAND (t
, 1)), arg1
);
8170 tem
= fold_convert (type
, negate_expr (tem
));
8171 return pedantic_non_lvalue (tem
);
8173 return pedantic_non_lvalue (fold_convert (type
, arg1
));
8176 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
8177 arg1
= fold_convert ((*lang_hooks
.types
.signed_type
)
8178 (TREE_TYPE (arg1
)), arg1
);
8179 arg1
= fold (build1 (ABS_EXPR
, TREE_TYPE (arg1
), arg1
));
8180 return pedantic_non_lvalue (fold_convert (type
, arg1
));
8183 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
8184 arg1
= fold_convert ((lang_hooks
.types
.signed_type
)
8185 (TREE_TYPE (arg1
)), arg1
);
8186 arg1
= fold (build1 (ABS_EXPR
, TREE_TYPE (arg1
), arg1
));
8187 arg1
= negate_expr (fold_convert (type
, arg1
));
8188 return pedantic_non_lvalue (arg1
);
8193 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
8194 A == 0 ? A : 0 is always 0 unless A is -0. Note that
8195 both transformations are correct when A is NaN: A != 0
8196 is then true, and A == 0 is false. */
8198 if (integer_zerop (TREE_OPERAND (arg0
, 1)) && integer_zerop (arg2
))
8200 if (comp_code
== NE_EXPR
)
8201 return pedantic_non_lvalue (fold_convert (type
, arg1
));
8202 else if (comp_code
== EQ_EXPR
)
8203 return pedantic_non_lvalue (fold_convert (type
, integer_zero_node
));
8206 /* Try some transformations of A op B ? A : B.
8208 A == B? A : B same as B
8209 A != B? A : B same as A
8210 A >= B? A : B same as max (A, B)
8211 A > B? A : B same as max (B, A)
8212 A <= B? A : B same as min (A, B)
8213 A < B? A : B same as min (B, A)
8215 As above, these transformations don't work in the presence
8216 of signed zeros. For example, if A and B are zeros of
8217 opposite sign, the first two transformations will change
8218 the sign of the result. In the last four, the original
8219 expressions give different results for (A=+0, B=-0) and
8220 (A=-0, B=+0), but the transformed expressions do not.
8222 The first two transformations are correct if either A or B
8223 is a NaN. In the first transformation, the condition will
8224 be false, and B will indeed be chosen. In the case of the
8225 second transformation, the condition A != B will be true,
8226 and A will be chosen.
8228 The conversions to max() and min() are not correct if B is
8229 a number and A is not. The conditions in the original
8230 expressions will be false, so all four give B. The min()
8231 and max() versions would give a NaN instead. */
8232 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 1),
8233 arg2
, TREE_OPERAND (arg0
, 0)))
8235 tree comp_op0
= TREE_OPERAND (arg0
, 0);
8236 tree comp_op1
= TREE_OPERAND (arg0
, 1);
8237 tree comp_type
= TREE_TYPE (comp_op0
);
8239 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
8240 if (TYPE_MAIN_VARIANT (comp_type
) == TYPE_MAIN_VARIANT (type
))
8250 return pedantic_non_lvalue (fold_convert (type
, arg2
));
8252 return pedantic_non_lvalue (fold_convert (type
, arg1
));
8255 /* In C++ a ?: expression can be an lvalue, so put the
8256 operand which will be used if they are equal first
8257 so that we can convert this back to the
8258 corresponding COND_EXPR. */
8259 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
8260 return pedantic_non_lvalue (fold_convert
8261 (type
, fold (build (MIN_EXPR
, comp_type
,
8262 (comp_code
== LE_EXPR
8263 ? comp_op0
: comp_op1
),
8264 (comp_code
== LE_EXPR
8265 ? comp_op1
: comp_op0
)))));
8269 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
8270 return pedantic_non_lvalue (fold_convert
8271 (type
, fold (build (MAX_EXPR
, comp_type
,
8272 (comp_code
== GE_EXPR
8273 ? comp_op0
: comp_op1
),
8274 (comp_code
== GE_EXPR
8275 ? comp_op1
: comp_op0
)))));
8282 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
8283 we might still be able to simplify this. For example,
8284 if C1 is one less or one more than C2, this might have started
8285 out as a MIN or MAX and been transformed by this function.
8286 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
8288 if (INTEGRAL_TYPE_P (type
)
8289 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
8290 && TREE_CODE (arg2
) == INTEGER_CST
)
8294 /* We can replace A with C1 in this case. */
8295 arg1
= fold_convert (type
, TREE_OPERAND (arg0
, 1));
8296 return fold (build (code
, type
, TREE_OPERAND (t
, 0), arg1
,
8297 TREE_OPERAND (t
, 2)));
8300 /* If C1 is C2 + 1, this is min(A, C2). */
8301 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
8302 && operand_equal_p (TREE_OPERAND (arg0
, 1),
8303 const_binop (PLUS_EXPR
, arg2
,
8304 integer_one_node
, 0), 1))
8305 return pedantic_non_lvalue
8306 (fold (build (MIN_EXPR
, type
, arg1
, arg2
)));
8310 /* If C1 is C2 - 1, this is min(A, C2). */
8311 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
8312 && operand_equal_p (TREE_OPERAND (arg0
, 1),
8313 const_binop (MINUS_EXPR
, arg2
,
8314 integer_one_node
, 0), 1))
8315 return pedantic_non_lvalue
8316 (fold (build (MIN_EXPR
, type
, arg1
, arg2
)));
8320 /* If C1 is C2 - 1, this is max(A, C2). */
8321 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
8322 && operand_equal_p (TREE_OPERAND (arg0
, 1),
8323 const_binop (MINUS_EXPR
, arg2
,
8324 integer_one_node
, 0), 1))
8325 return pedantic_non_lvalue
8326 (fold (build (MAX_EXPR
, type
, arg1
, arg2
)));
8330 /* If C1 is C2 + 1, this is max(A, C2). */
8331 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
8332 && operand_equal_p (TREE_OPERAND (arg0
, 1),
8333 const_binop (PLUS_EXPR
, arg2
,
8334 integer_one_node
, 0), 1))
8335 return pedantic_non_lvalue
8336 (fold (build (MAX_EXPR
, type
, arg1
, arg2
)));
8345 /* If the second operand is simpler than the third, swap them
8346 since that produces better jump optimization results. */
8347 if (tree_swap_operands_p (TREE_OPERAND (t
, 1),
8348 TREE_OPERAND (t
, 2), false))
8350 /* See if this can be inverted. If it can't, possibly because
8351 it was a floating-point inequality comparison, don't do
8353 tem
= invert_truthvalue (arg0
);
8355 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
8356 return fold (build (code
, type
, tem
,
8357 TREE_OPERAND (t
, 2), TREE_OPERAND (t
, 1)));
8360 /* Convert A ? 1 : 0 to simply A. */
8361 if (integer_onep (TREE_OPERAND (t
, 1))
8362 && integer_zerop (TREE_OPERAND (t
, 2))
8363 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
8364 call to fold will try to move the conversion inside
8365 a COND, which will recurse. In that case, the COND_EXPR
8366 is probably the best choice, so leave it alone. */
8367 && type
== TREE_TYPE (arg0
))
8368 return pedantic_non_lvalue (arg0
);
8370 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
8371 over COND_EXPR in cases such as floating point comparisons. */
8372 if (integer_zerop (TREE_OPERAND (t
, 1))
8373 && integer_onep (TREE_OPERAND (t
, 2))
8374 && truth_value_p (TREE_CODE (arg0
)))
8375 return pedantic_non_lvalue (fold_convert (type
,
8376 invert_truthvalue (arg0
)));
8378 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
8379 operation is simply A & 2. */
8381 if (integer_zerop (TREE_OPERAND (t
, 2))
8382 && TREE_CODE (arg0
) == NE_EXPR
8383 && integer_zerop (TREE_OPERAND (arg0
, 1))
8384 && integer_pow2p (arg1
)
8385 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == BIT_AND_EXPR
8386 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1),
8388 return pedantic_non_lvalue (fold_convert (type
,
8389 TREE_OPERAND (arg0
, 0)));
8391 /* Convert A ? B : 0 into A && B if A and B are truth values. */
8392 if (integer_zerop (TREE_OPERAND (t
, 2))
8393 && truth_value_p (TREE_CODE (arg0
))
8394 && truth_value_p (TREE_CODE (arg1
)))
8395 return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR
, type
,
8398 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
8399 if (integer_onep (TREE_OPERAND (t
, 2))
8400 && truth_value_p (TREE_CODE (arg0
))
8401 && truth_value_p (TREE_CODE (arg1
)))
8403 /* Only perform transformation if ARG0 is easily inverted. */
8404 tem
= invert_truthvalue (arg0
);
8405 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
8406 return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR
, type
,
8413 /* When pedantic, a compound expression can be neither an lvalue
8414 nor an integer constant expression. */
8415 if (TREE_SIDE_EFFECTS (arg0
) || TREE_CONSTANT (arg1
))
8417 /* Don't let (0, 0) be null pointer constant. */
8418 tem
= integer_zerop (arg1
) ? build1 (NOP_EXPR
, type
, arg1
)
8419 : fold_convert (type
, arg1
);
8420 return pedantic_non_lvalue (tem
);
8424 return build_complex (type
, arg0
, arg1
);
8428 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
8430 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
8431 return omit_one_operand (type
, TREE_OPERAND (arg0
, 0),
8432 TREE_OPERAND (arg0
, 1));
8433 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
8434 return TREE_REALPART (arg0
);
8435 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
8436 return fold (build (TREE_CODE (arg0
), type
,
8437 fold (build1 (REALPART_EXPR
, type
,
8438 TREE_OPERAND (arg0
, 0))),
8439 fold (build1 (REALPART_EXPR
,
8440 type
, TREE_OPERAND (arg0
, 1)))));
8444 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
8445 return fold_convert (type
, integer_zero_node
);
8446 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
8447 return omit_one_operand (type
, TREE_OPERAND (arg0
, 1),
8448 TREE_OPERAND (arg0
, 0));
8449 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
8450 return TREE_IMAGPART (arg0
);
8451 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
8452 return fold (build (TREE_CODE (arg0
), type
,
8453 fold (build1 (IMAGPART_EXPR
, type
,
8454 TREE_OPERAND (arg0
, 0))),
8455 fold (build1 (IMAGPART_EXPR
, type
,
8456 TREE_OPERAND (arg0
, 1)))));
8459 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
8461 case CLEANUP_POINT_EXPR
:
8462 if (! has_cleanups (arg0
))
8463 return TREE_OPERAND (t
, 0);
8466 enum tree_code code0
= TREE_CODE (arg0
);
8467 int kind0
= TREE_CODE_CLASS (code0
);
8468 tree arg00
= TREE_OPERAND (arg0
, 0);
8471 if (kind0
== '1' || code0
== TRUTH_NOT_EXPR
)
8472 return fold (build1 (code0
, type
,
8473 fold (build1 (CLEANUP_POINT_EXPR
,
8474 TREE_TYPE (arg00
), arg00
))));
8476 if (kind0
== '<' || kind0
== '2'
8477 || code0
== TRUTH_ANDIF_EXPR
|| code0
== TRUTH_ORIF_EXPR
8478 || code0
== TRUTH_AND_EXPR
|| code0
== TRUTH_OR_EXPR
8479 || code0
== TRUTH_XOR_EXPR
)
8481 arg01
= TREE_OPERAND (arg0
, 1);
8483 if (TREE_CONSTANT (arg00
)
8484 || ((code0
== TRUTH_ANDIF_EXPR
|| code0
== TRUTH_ORIF_EXPR
)
8485 && ! has_cleanups (arg00
)))
8486 return fold (build (code0
, type
, arg00
,
8487 fold (build1 (CLEANUP_POINT_EXPR
,
8488 TREE_TYPE (arg01
), arg01
))));
8490 if (TREE_CONSTANT (arg01
))
8491 return fold (build (code0
, type
,
8492 fold (build1 (CLEANUP_POINT_EXPR
,
8493 TREE_TYPE (arg00
), arg00
)),
8501 /* Check for a built-in function. */
8502 if (TREE_CODE (TREE_OPERAND (expr
, 0)) == ADDR_EXPR
8503 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr
, 0), 0))
8505 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr
, 0), 0)))
8507 tree tmp
= fold_builtin (expr
);
8515 } /* switch (code) */
8518 #ifdef ENABLE_FOLD_CHECKING
8521 static void fold_checksum_tree (tree
, struct md5_ctx
*, htab_t
);
8522 static void fold_check_failed (tree
, tree
);
8523 void print_fold_checksum (tree
);
8525 /* When --enable-checking=fold, compute a digest of expr before
8526 and after actual fold call to see if fold did not accidentally
8527 change original expr. */
8534 unsigned char checksum_before
[16], checksum_after
[16];
8537 ht
= htab_create (32, htab_hash_pointer
, htab_eq_pointer
, NULL
);
8538 md5_init_ctx (&ctx
);
8539 fold_checksum_tree (expr
, &ctx
, ht
);
8540 md5_finish_ctx (&ctx
, checksum_before
);
8543 ret
= fold_1 (expr
);
8545 md5_init_ctx (&ctx
);
8546 fold_checksum_tree (expr
, &ctx
, ht
);
8547 md5_finish_ctx (&ctx
, checksum_after
);
8550 if (memcmp (checksum_before
, checksum_after
, 16))
8551 fold_check_failed (expr
, ret
);
8557 print_fold_checksum (tree expr
)
8560 unsigned char checksum
[16], cnt
;
8563 ht
= htab_create (32, htab_hash_pointer
, htab_eq_pointer
, NULL
);
8564 md5_init_ctx (&ctx
);
8565 fold_checksum_tree (expr
, &ctx
, ht
);
8566 md5_finish_ctx (&ctx
, checksum
);
8568 for (cnt
= 0; cnt
< 16; ++cnt
)
8569 fprintf (stderr
, "%02x", checksum
[cnt
]);
8570 putc ('\n', stderr
);
8574 fold_check_failed (tree expr ATTRIBUTE_UNUSED
, tree ret ATTRIBUTE_UNUSED
)
8576 internal_error ("fold check: original tree changed by fold");
8580 fold_checksum_tree (tree expr
, struct md5_ctx
*ctx
, htab_t ht
)
8583 enum tree_code code
;
8584 char buf
[sizeof (struct tree_decl
)];
8587 if (sizeof (struct tree_exp
) + 5 * sizeof (tree
)
8588 > sizeof (struct tree_decl
)
8589 || sizeof (struct tree_type
) > sizeof (struct tree_decl
))
8593 slot
= htab_find_slot (ht
, expr
, INSERT
);
8597 code
= TREE_CODE (expr
);
8598 if (code
== SAVE_EXPR
&& SAVE_EXPR_NOPLACEHOLDER (expr
))
8600 /* Allow SAVE_EXPR_NOPLACEHOLDER flag to be modified. */
8601 memcpy (buf
, expr
, tree_size (expr
));
8603 SAVE_EXPR_NOPLACEHOLDER (expr
) = 0;
8605 else if (TREE_CODE_CLASS (code
) == 'd' && DECL_ASSEMBLER_NAME_SET_P (expr
))
8607 /* Allow DECL_ASSEMBLER_NAME to be modified. */
8608 memcpy (buf
, expr
, tree_size (expr
));
8610 SET_DECL_ASSEMBLER_NAME (expr
, NULL
);
8612 else if (TREE_CODE_CLASS (code
) == 't'
8613 && (TYPE_POINTER_TO (expr
) || TYPE_REFERENCE_TO (expr
)))
8615 /* Allow TYPE_POINTER_TO and TYPE_REFERENCE_TO to be modified. */
8616 memcpy (buf
, expr
, tree_size (expr
));
8618 TYPE_POINTER_TO (expr
) = NULL
;
8619 TYPE_REFERENCE_TO (expr
) = NULL
;
8621 md5_process_bytes (expr
, tree_size (expr
), ctx
);
8622 fold_checksum_tree (TREE_TYPE (expr
), ctx
, ht
);
8623 if (TREE_CODE_CLASS (code
) != 't' && TREE_CODE_CLASS (code
) != 'd')
8624 fold_checksum_tree (TREE_CHAIN (expr
), ctx
, ht
);
8625 len
= TREE_CODE_LENGTH (code
);
8626 switch (TREE_CODE_CLASS (code
))
8632 md5_process_bytes (TREE_STRING_POINTER (expr
),
8633 TREE_STRING_LENGTH (expr
), ctx
);
8636 fold_checksum_tree (TREE_REALPART (expr
), ctx
, ht
);
8637 fold_checksum_tree (TREE_IMAGPART (expr
), ctx
, ht
);
8640 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr
), ctx
, ht
);
8650 fold_checksum_tree (TREE_PURPOSE (expr
), ctx
, ht
);
8651 fold_checksum_tree (TREE_VALUE (expr
), ctx
, ht
);
8654 for (i
= 0; i
< TREE_VEC_LENGTH (expr
); ++i
)
8655 fold_checksum_tree (TREE_VEC_ELT (expr
, i
), ctx
, ht
);
8664 case SAVE_EXPR
: len
= 2; break;
8665 case GOTO_SUBROUTINE_EXPR
: len
= 0; break;
8666 case RTL_EXPR
: len
= 0; break;
8667 case WITH_CLEANUP_EXPR
: len
= 2; break;
8676 for (i
= 0; i
< len
; ++i
)
8677 fold_checksum_tree (TREE_OPERAND (expr
, i
), ctx
, ht
);
8680 fold_checksum_tree (DECL_SIZE (expr
), ctx
, ht
);
8681 fold_checksum_tree (DECL_SIZE_UNIT (expr
), ctx
, ht
);
8682 fold_checksum_tree (DECL_NAME (expr
), ctx
, ht
);
8683 fold_checksum_tree (DECL_CONTEXT (expr
), ctx
, ht
);
8684 fold_checksum_tree (DECL_ARGUMENTS (expr
), ctx
, ht
);
8685 fold_checksum_tree (DECL_RESULT_FLD (expr
), ctx
, ht
);
8686 fold_checksum_tree (DECL_INITIAL (expr
), ctx
, ht
);
8687 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr
), ctx
, ht
);
8688 fold_checksum_tree (DECL_SECTION_NAME (expr
), ctx
, ht
);
8689 fold_checksum_tree (DECL_ATTRIBUTES (expr
), ctx
, ht
);
8690 fold_checksum_tree (DECL_VINDEX (expr
), ctx
, ht
);
8693 fold_checksum_tree (TYPE_VALUES (expr
), ctx
, ht
);
8694 fold_checksum_tree (TYPE_SIZE (expr
), ctx
, ht
);
8695 fold_checksum_tree (TYPE_SIZE_UNIT (expr
), ctx
, ht
);
8696 fold_checksum_tree (TYPE_ATTRIBUTES (expr
), ctx
, ht
);
8697 fold_checksum_tree (TYPE_NAME (expr
), ctx
, ht
);
8698 fold_checksum_tree (TYPE_MIN_VALUE (expr
), ctx
, ht
);
8699 fold_checksum_tree (TYPE_MAX_VALUE (expr
), ctx
, ht
);
8700 fold_checksum_tree (TYPE_MAIN_VARIANT (expr
), ctx
, ht
);
8701 fold_checksum_tree (TYPE_BINFO (expr
), ctx
, ht
);
8702 fold_checksum_tree (TYPE_CONTEXT (expr
), ctx
, ht
);
8711 /* Perform constant folding and related simplification of initializer
8712 expression EXPR. This behaves identically to "fold" but ignores
8713 potential run-time traps and exceptions that fold must preserve. */
8716 fold_initializer (tree expr
)
8718 int saved_signaling_nans
= flag_signaling_nans
;
8719 int saved_trapping_math
= flag_trapping_math
;
8720 int saved_trapv
= flag_trapv
;
8723 flag_signaling_nans
= 0;
8724 flag_trapping_math
= 0;
8727 result
= fold (expr
);
8729 flag_signaling_nans
= saved_signaling_nans
;
8730 flag_trapping_math
= saved_trapping_math
;
8731 flag_trapv
= saved_trapv
;
8736 /* Determine if first argument is a multiple of second argument. Return 0 if
8737 it is not, or we cannot easily determined it to be.
8739 An example of the sort of thing we care about (at this point; this routine
8740 could surely be made more general, and expanded to do what the *_DIV_EXPR's
8741 fold cases do now) is discovering that
8743 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
8749 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
8751 This code also handles discovering that
8753 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
8755 is a multiple of 8 so we don't have to worry about dealing with a
8758 Note that we *look* inside a SAVE_EXPR only to determine how it was
8759 calculated; it is not safe for fold to do much of anything else with the
8760 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
8761 at run time. For example, the latter example above *cannot* be implemented
8762 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
8763 evaluation time of the original SAVE_EXPR is not necessarily the same at
8764 the time the new expression is evaluated. The only optimization of this
8765 sort that would be valid is changing
8767 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
8771 SAVE_EXPR (I) * SAVE_EXPR (J)
8773 (where the same SAVE_EXPR (J) is used in the original and the
8774 transformed version). */
8777 multiple_of_p (tree type
, tree top
, tree bottom
)
8779 if (operand_equal_p (top
, bottom
, 0))
8782 if (TREE_CODE (type
) != INTEGER_TYPE
)
8785 switch (TREE_CODE (top
))
8788 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
8789 || multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
8793 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
8794 && multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
8797 if (TREE_CODE (TREE_OPERAND (top
, 1)) == INTEGER_CST
)
8801 op1
= TREE_OPERAND (top
, 1);
8802 /* const_binop may not detect overflow correctly,
8803 so check for it explicitly here. */
8804 if (TYPE_PRECISION (TREE_TYPE (size_one_node
))
8805 > TREE_INT_CST_LOW (op1
)
8806 && TREE_INT_CST_HIGH (op1
) == 0
8807 && 0 != (t1
= fold_convert (type
,
8808 const_binop (LSHIFT_EXPR
,
8811 && ! TREE_OVERFLOW (t1
))
8812 return multiple_of_p (type
, t1
, bottom
);
8817 /* Can't handle conversions from non-integral or wider integral type. */
8818 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top
, 0))) != INTEGER_TYPE
)
8819 || (TYPE_PRECISION (type
)
8820 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top
, 0)))))
8823 /* .. fall through ... */
8826 return multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
);
8829 if (TREE_CODE (bottom
) != INTEGER_CST
8830 || (TREE_UNSIGNED (type
)
8831 && (tree_int_cst_sgn (top
) < 0
8832 || tree_int_cst_sgn (bottom
) < 0)))
8834 return integer_zerop (const_binop (TRUNC_MOD_EXPR
,
8842 /* Return true if `t' is known to be non-negative. */
8845 tree_expr_nonnegative_p (tree t
)
8847 switch (TREE_CODE (t
))
8853 return tree_int_cst_sgn (t
) >= 0;
8856 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t
));
8859 if (FLOAT_TYPE_P (TREE_TYPE (t
)))
8860 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8861 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8863 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
8864 both unsigned and at least 2 bits shorter than the result. */
8865 if (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
8866 && TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
8867 && TREE_CODE (TREE_OPERAND (t
, 1)) == NOP_EXPR
)
8869 tree inner1
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
8870 tree inner2
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0));
8871 if (TREE_CODE (inner1
) == INTEGER_TYPE
&& TREE_UNSIGNED (inner1
)
8872 && TREE_CODE (inner2
) == INTEGER_TYPE
&& TREE_UNSIGNED (inner2
))
8874 unsigned int prec
= MAX (TYPE_PRECISION (inner1
),
8875 TYPE_PRECISION (inner2
)) + 1;
8876 return prec
< TYPE_PRECISION (TREE_TYPE (t
));
8882 if (FLOAT_TYPE_P (TREE_TYPE (t
)))
8884 /* x * x for floating point x is always non-negative. */
8885 if (operand_equal_p (TREE_OPERAND (t
, 0), TREE_OPERAND (t
, 1), 0))
8887 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8888 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8891 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
8892 both unsigned and their total bits is shorter than the result. */
8893 if (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
8894 && TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
8895 && TREE_CODE (TREE_OPERAND (t
, 1)) == NOP_EXPR
)
8897 tree inner1
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
8898 tree inner2
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0));
8899 if (TREE_CODE (inner1
) == INTEGER_TYPE
&& TREE_UNSIGNED (inner1
)
8900 && TREE_CODE (inner2
) == INTEGER_TYPE
&& TREE_UNSIGNED (inner2
))
8901 return TYPE_PRECISION (inner1
) + TYPE_PRECISION (inner2
)
8902 < TYPE_PRECISION (TREE_TYPE (t
));
8906 case TRUNC_DIV_EXPR
:
8908 case FLOOR_DIV_EXPR
:
8909 case ROUND_DIV_EXPR
:
8910 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8911 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8913 case TRUNC_MOD_EXPR
:
8915 case FLOOR_MOD_EXPR
:
8916 case ROUND_MOD_EXPR
:
8917 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
8920 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8921 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8925 tree inner_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
8926 tree outer_type
= TREE_TYPE (t
);
8928 if (TREE_CODE (outer_type
) == REAL_TYPE
)
8930 if (TREE_CODE (inner_type
) == REAL_TYPE
)
8931 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
8932 if (TREE_CODE (inner_type
) == INTEGER_TYPE
)
8934 if (TREE_UNSIGNED (inner_type
))
8936 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
8939 else if (TREE_CODE (outer_type
) == INTEGER_TYPE
)
8941 if (TREE_CODE (inner_type
) == REAL_TYPE
)
8942 return tree_expr_nonnegative_p (TREE_OPERAND (t
,0));
8943 if (TREE_CODE (inner_type
) == INTEGER_TYPE
)
8944 return TYPE_PRECISION (inner_type
) < TYPE_PRECISION (outer_type
)
8945 && TREE_UNSIGNED (inner_type
);
8951 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1))
8952 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 2));
8954 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8956 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8957 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8959 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8960 || tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8962 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8964 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8966 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
8967 case NON_LVALUE_EXPR
:
8968 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
8970 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
8972 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t
));
8976 tree fndecl
= get_callee_fndecl (t
);
8977 tree arglist
= TREE_OPERAND (t
, 1);
8979 && DECL_BUILT_IN (fndecl
)
8980 && DECL_BUILT_IN_CLASS (fndecl
) != BUILT_IN_MD
)
8981 switch (DECL_FUNCTION_CODE (fndecl
))
8984 case BUILT_IN_CABSL
:
8985 case BUILT_IN_CABSF
:
8990 case BUILT_IN_EXP2F
:
8991 case BUILT_IN_EXP2L
:
8992 case BUILT_IN_EXP10
:
8993 case BUILT_IN_EXP10F
:
8994 case BUILT_IN_EXP10L
:
8996 case BUILT_IN_FABSF
:
8997 case BUILT_IN_FABSL
:
9000 case BUILT_IN_FFSLL
:
9001 case BUILT_IN_PARITY
:
9002 case BUILT_IN_PARITYL
:
9003 case BUILT_IN_PARITYLL
:
9004 case BUILT_IN_POPCOUNT
:
9005 case BUILT_IN_POPCOUNTL
:
9006 case BUILT_IN_POPCOUNTLL
:
9007 case BUILT_IN_POW10
:
9008 case BUILT_IN_POW10F
:
9009 case BUILT_IN_POW10L
:
9011 case BUILT_IN_SQRTF
:
9012 case BUILT_IN_SQRTL
:
9016 case BUILT_IN_ATANF
:
9017 case BUILT_IN_ATANL
:
9019 case BUILT_IN_CEILF
:
9020 case BUILT_IN_CEILL
:
9021 case BUILT_IN_FLOOR
:
9022 case BUILT_IN_FLOORF
:
9023 case BUILT_IN_FLOORL
:
9024 case BUILT_IN_NEARBYINT
:
9025 case BUILT_IN_NEARBYINTF
:
9026 case BUILT_IN_NEARBYINTL
:
9027 case BUILT_IN_ROUND
:
9028 case BUILT_IN_ROUNDF
:
9029 case BUILT_IN_ROUNDL
:
9030 case BUILT_IN_TRUNC
:
9031 case BUILT_IN_TRUNCF
:
9032 case BUILT_IN_TRUNCL
:
9033 return tree_expr_nonnegative_p (TREE_VALUE (arglist
));
9038 return tree_expr_nonnegative_p (TREE_VALUE (arglist
));
9045 /* ... fall through ... */
9048 if (truth_value_p (TREE_CODE (t
)))
9049 /* Truth values evaluate to 0 or 1, which is nonnegative. */
9053 /* We don't know sign of `t', so be conservative and return false. */
9057 /* Return true if `r' is known to be non-negative.
9058 Only handles constants at the moment. */
9061 rtl_expr_nonnegative_p (rtx r
)
9063 switch (GET_CODE (r
))
9066 return INTVAL (r
) >= 0;
9069 if (GET_MODE (r
) == VOIDmode
)
9070 return CONST_DOUBLE_HIGH (r
) >= 0;
9078 units
= CONST_VECTOR_NUNITS (r
);
9080 for (i
= 0; i
< units
; ++i
)
9082 elt
= CONST_VECTOR_ELT (r
, i
);
9083 if (!rtl_expr_nonnegative_p (elt
))
9092 /* These are always nonnegative. */
9100 #include "gt-fold-const.h"