1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001, 2002, 2003, 2004, 2005 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, 51 Franklin Street, Fifth Floor, Boston, MA
22 /*@@ This file should be rewritten to use an arbitrary precision
23 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
24 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
25 @@ The routines that translate from the ap rep should
26 @@ warn if precision et. al. is lost.
27 @@ This would also make life easier when this technology is used
28 @@ for cross-compilers. */
30 /* The entry points in this file are fold, size_int_wide, size_binop
33 fold takes a tree as argument and returns a simplified tree.
35 size_binop takes a tree code for an arithmetic operation
36 and two operands that are trees, and produces a tree for the
37 result, assuming the type comes from `sizetype'.
39 size_int takes an integer value, and creates a tree constant
40 with type from `sizetype'.
42 force_fit_type takes a constant, an overflowable flag and prior
43 overflow indicators. It forces the value to fit the type and sets
44 TREE_OVERFLOW and TREE_CONSTANT_OVERFLOW as appropriate. */
48 #include "coretypes.h"
59 #include "langhooks.h"
62 /* The following constants represent a bit based encoding of GCC's
63 comparison operators. This encoding simplifies transformations
64 on relational comparison operators, such as AND and OR. */
65 enum comparison_code
{
84 static void encode (HOST_WIDE_INT
*, unsigned HOST_WIDE_INT
, HOST_WIDE_INT
);
85 static void decode (HOST_WIDE_INT
*, unsigned HOST_WIDE_INT
*, HOST_WIDE_INT
*);
86 static bool negate_mathfn_p (enum built_in_function
);
87 static bool negate_expr_p (tree
);
88 static tree
negate_expr (tree
);
89 static tree
split_tree (tree
, enum tree_code
, tree
*, tree
*, tree
*, int);
90 static tree
associate_trees (tree
, tree
, enum tree_code
, tree
);
91 static tree
const_binop (enum tree_code
, tree
, tree
, int);
92 static enum comparison_code
comparison_to_compcode (enum tree_code
);
93 static enum tree_code
compcode_to_comparison (enum comparison_code
);
94 static tree
combine_comparisons (enum tree_code
, enum tree_code
,
95 enum tree_code
, tree
, tree
, tree
);
96 static int truth_value_p (enum tree_code
);
97 static int operand_equal_for_comparison_p (tree
, tree
, tree
);
98 static int twoval_comparison_p (tree
, tree
*, tree
*, int *);
99 static tree
eval_subst (tree
, tree
, tree
, tree
, tree
);
100 static tree
pedantic_omit_one_operand (tree
, tree
, tree
);
101 static tree
distribute_bit_expr (enum tree_code
, tree
, tree
, tree
);
102 static tree
make_bit_field_ref (tree
, tree
, int, int, int);
103 static tree
optimize_bit_field_compare (enum tree_code
, tree
, tree
, tree
);
104 static tree
decode_field_reference (tree
, HOST_WIDE_INT
*, HOST_WIDE_INT
*,
105 enum machine_mode
*, int *, int *,
107 static int all_ones_mask_p (tree
, int);
108 static tree
sign_bit_p (tree
, tree
);
109 static int simple_operand_p (tree
);
110 static tree
range_binop (enum tree_code
, tree
, tree
, int, tree
, int);
111 static tree
make_range (tree
, int *, tree
*, tree
*);
112 static tree
build_range_check (tree
, tree
, int, tree
, tree
);
113 static int merge_ranges (int *, tree
*, tree
*, int, tree
, tree
, int, tree
,
115 static tree
fold_range_test (enum tree_code
, tree
, tree
, tree
);
116 static tree
fold_cond_expr_with_comparison (tree
, tree
, tree
, tree
);
117 static tree
unextend (tree
, int, int, tree
);
118 static tree
fold_truthop (enum tree_code
, tree
, tree
, tree
);
119 static tree
optimize_minmax_comparison (enum tree_code
, tree
, tree
, tree
);
120 static tree
extract_muldiv (tree
, tree
, enum tree_code
, tree
);
121 static tree
extract_muldiv_1 (tree
, tree
, enum tree_code
, tree
);
122 static int multiple_of_p (tree
, tree
, tree
);
123 static tree
fold_binary_op_with_conditional_arg (enum tree_code
, tree
,
126 static bool fold_real_zero_addition_p (tree
, tree
, int);
127 static tree
fold_mathfn_compare (enum built_in_function
, enum tree_code
,
129 static tree
fold_inf_compare (enum tree_code
, tree
, tree
, tree
);
130 static tree
fold_div_compare (enum tree_code
, tree
, tree
, tree
);
131 static bool reorder_operands_p (tree
, tree
);
132 static tree
fold_negate_const (tree
, tree
);
133 static tree
fold_not_const (tree
, tree
);
134 static tree
fold_relational_const (enum tree_code
, tree
, tree
, tree
);
136 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
137 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
138 and SUM1. Then this yields nonzero if overflow occurred during the
141 Overflow occurs if A and B have the same sign, but A and SUM differ in
142 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
144 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
146 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
147 We do that by representing the two-word integer in 4 words, with only
148 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
149 number. The value of the word is LOWPART + HIGHPART * BASE. */
152 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
153 #define HIGHPART(x) \
154 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
155 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
157 /* Unpack a two-word integer into 4 words.
158 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
159 WORDS points to the array of HOST_WIDE_INTs. */
162 encode (HOST_WIDE_INT
*words
, unsigned HOST_WIDE_INT low
, HOST_WIDE_INT hi
)
164 words
[0] = LOWPART (low
);
165 words
[1] = HIGHPART (low
);
166 words
[2] = LOWPART (hi
);
167 words
[3] = HIGHPART (hi
);
170 /* Pack an array of 4 words into a two-word integer.
171 WORDS points to the array of words.
172 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
175 decode (HOST_WIDE_INT
*words
, unsigned HOST_WIDE_INT
*low
,
178 *low
= words
[0] + words
[1] * BASE
;
179 *hi
= words
[2] + words
[3] * BASE
;
182 /* T is an INT_CST node. OVERFLOWABLE indicates if we are interested
183 in overflow of the value, when >0 we are only interested in signed
184 overflow, for <0 we are interested in any overflow. OVERFLOWED
185 indicates whether overflow has already occurred. CONST_OVERFLOWED
186 indicates whether constant overflow has already occurred. We force
187 T's value to be within range of T's type (by setting to 0 or 1 all
188 the bits outside the type's range). We set TREE_OVERFLOWED if,
189 OVERFLOWED is nonzero,
190 or OVERFLOWABLE is >0 and signed overflow occurs
191 or OVERFLOWABLE is <0 and any overflow occurs
192 We set TREE_CONSTANT_OVERFLOWED if,
193 CONST_OVERFLOWED is nonzero
194 or we set TREE_OVERFLOWED.
195 We return either the original T, or a copy. */
198 force_fit_type (tree t
, int overflowable
,
199 bool overflowed
, bool overflowed_const
)
201 unsigned HOST_WIDE_INT low
;
204 int sign_extended_type
;
206 gcc_assert (TREE_CODE (t
) == INTEGER_CST
);
208 low
= TREE_INT_CST_LOW (t
);
209 high
= TREE_INT_CST_HIGH (t
);
211 if (POINTER_TYPE_P (TREE_TYPE (t
))
212 || TREE_CODE (TREE_TYPE (t
)) == OFFSET_TYPE
)
215 prec
= TYPE_PRECISION (TREE_TYPE (t
));
216 /* Size types *are* sign extended. */
217 sign_extended_type
= (!TYPE_UNSIGNED (TREE_TYPE (t
))
218 || (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
219 && TYPE_IS_SIZETYPE (TREE_TYPE (t
))));
221 /* First clear all bits that are beyond the type's precision. */
223 if (prec
>= 2 * HOST_BITS_PER_WIDE_INT
)
225 else if (prec
> HOST_BITS_PER_WIDE_INT
)
226 high
&= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
230 if (prec
< HOST_BITS_PER_WIDE_INT
)
231 low
&= ~((HOST_WIDE_INT
) (-1) << prec
);
234 if (!sign_extended_type
)
235 /* No sign extension */;
236 else if (prec
>= 2 * HOST_BITS_PER_WIDE_INT
)
237 /* Correct width already. */;
238 else if (prec
> HOST_BITS_PER_WIDE_INT
)
240 /* Sign extend top half? */
241 if (high
& ((unsigned HOST_WIDE_INT
)1
242 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)))
243 high
|= (HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
);
245 else if (prec
== HOST_BITS_PER_WIDE_INT
)
247 if ((HOST_WIDE_INT
)low
< 0)
252 /* Sign extend bottom half? */
253 if (low
& ((unsigned HOST_WIDE_INT
)1 << (prec
- 1)))
256 low
|= (HOST_WIDE_INT
)(-1) << prec
;
260 /* If the value changed, return a new node. */
261 if (overflowed
|| overflowed_const
262 || low
!= TREE_INT_CST_LOW (t
) || high
!= TREE_INT_CST_HIGH (t
))
264 t
= build_int_cst_wide (TREE_TYPE (t
), low
, high
);
268 || (overflowable
> 0 && sign_extended_type
))
271 TREE_OVERFLOW (t
) = 1;
272 TREE_CONSTANT_OVERFLOW (t
) = 1;
274 else if (overflowed_const
)
277 TREE_CONSTANT_OVERFLOW (t
) = 1;
284 /* Add two doubleword integers with doubleword result.
285 Each argument is given as two `HOST_WIDE_INT' pieces.
286 One argument is L1 and H1; the other, L2 and H2.
287 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
290 add_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
291 unsigned HOST_WIDE_INT l2
, HOST_WIDE_INT h2
,
292 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
294 unsigned HOST_WIDE_INT l
;
298 h
= h1
+ h2
+ (l
< l1
);
302 return OVERFLOW_SUM_SIGN (h1
, h2
, h
);
305 /* Negate a doubleword integer with doubleword result.
306 Return nonzero if the operation overflows, assuming it's signed.
307 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
308 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
311 neg_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
312 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
318 return (*hv
& h1
) < 0;
328 /* Multiply two doubleword integers with doubleword result.
329 Return nonzero if the operation overflows, assuming it's signed.
330 Each argument is given as two `HOST_WIDE_INT' pieces.
331 One argument is L1 and H1; the other, L2 and H2.
332 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
335 mul_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
336 unsigned HOST_WIDE_INT l2
, HOST_WIDE_INT h2
,
337 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
339 HOST_WIDE_INT arg1
[4];
340 HOST_WIDE_INT arg2
[4];
341 HOST_WIDE_INT prod
[4 * 2];
342 unsigned HOST_WIDE_INT carry
;
344 unsigned HOST_WIDE_INT toplow
, neglow
;
345 HOST_WIDE_INT tophigh
, neghigh
;
347 encode (arg1
, l1
, h1
);
348 encode (arg2
, l2
, h2
);
350 memset (prod
, 0, sizeof prod
);
352 for (i
= 0; i
< 4; i
++)
355 for (j
= 0; j
< 4; j
++)
358 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
359 carry
+= arg1
[i
] * arg2
[j
];
360 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
362 prod
[k
] = LOWPART (carry
);
363 carry
= HIGHPART (carry
);
368 decode (prod
, lv
, hv
); /* This ignores prod[4] through prod[4*2-1] */
370 /* Check for overflow by calculating the top half of the answer in full;
371 it should agree with the low half's sign bit. */
372 decode (prod
+ 4, &toplow
, &tophigh
);
375 neg_double (l2
, h2
, &neglow
, &neghigh
);
376 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
380 neg_double (l1
, h1
, &neglow
, &neghigh
);
381 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
383 return (*hv
< 0 ? ~(toplow
& tophigh
) : toplow
| tophigh
) != 0;
386 /* Shift the doubleword integer in L1, H1 left by COUNT places
387 keeping only PREC bits of result.
388 Shift right if COUNT is negative.
389 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
390 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
393 lshift_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
394 HOST_WIDE_INT count
, unsigned int prec
,
395 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
, int arith
)
397 unsigned HOST_WIDE_INT signmask
;
401 rshift_double (l1
, h1
, -count
, prec
, lv
, hv
, arith
);
405 if (SHIFT_COUNT_TRUNCATED
)
408 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
410 /* Shifting by the host word size is undefined according to the
411 ANSI standard, so we must handle this as a special case. */
415 else if (count
>= HOST_BITS_PER_WIDE_INT
)
417 *hv
= l1
<< (count
- HOST_BITS_PER_WIDE_INT
);
422 *hv
= (((unsigned HOST_WIDE_INT
) h1
<< count
)
423 | (l1
>> (HOST_BITS_PER_WIDE_INT
- count
- 1) >> 1));
427 /* Sign extend all bits that are beyond the precision. */
429 signmask
= -((prec
> HOST_BITS_PER_WIDE_INT
430 ? ((unsigned HOST_WIDE_INT
) *hv
431 >> (prec
- HOST_BITS_PER_WIDE_INT
- 1))
432 : (*lv
>> (prec
- 1))) & 1);
434 if (prec
>= 2 * HOST_BITS_PER_WIDE_INT
)
436 else if (prec
>= HOST_BITS_PER_WIDE_INT
)
438 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
439 *hv
|= signmask
<< (prec
- HOST_BITS_PER_WIDE_INT
);
444 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << prec
);
445 *lv
|= signmask
<< prec
;
449 /* Shift the doubleword integer in L1, H1 right by COUNT places
450 keeping only PREC bits of result. COUNT must be positive.
451 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
452 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
455 rshift_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
456 HOST_WIDE_INT count
, unsigned int prec
,
457 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
,
460 unsigned HOST_WIDE_INT signmask
;
463 ? -((unsigned HOST_WIDE_INT
) h1
>> (HOST_BITS_PER_WIDE_INT
- 1))
466 if (SHIFT_COUNT_TRUNCATED
)
469 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
471 /* Shifting by the host word size is undefined according to the
472 ANSI standard, so we must handle this as a special case. */
476 else if (count
>= HOST_BITS_PER_WIDE_INT
)
479 *lv
= (unsigned HOST_WIDE_INT
) h1
>> (count
- HOST_BITS_PER_WIDE_INT
);
483 *hv
= (unsigned HOST_WIDE_INT
) h1
>> count
;
485 | ((unsigned HOST_WIDE_INT
) h1
<< (HOST_BITS_PER_WIDE_INT
- count
- 1) << 1));
488 /* Zero / sign extend all bits that are beyond the precision. */
490 if (count
>= (HOST_WIDE_INT
)prec
)
495 else if ((prec
- count
) >= 2 * HOST_BITS_PER_WIDE_INT
)
497 else if ((prec
- count
) >= HOST_BITS_PER_WIDE_INT
)
499 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- count
- HOST_BITS_PER_WIDE_INT
));
500 *hv
|= signmask
<< (prec
- count
- HOST_BITS_PER_WIDE_INT
);
505 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << (prec
- count
));
506 *lv
|= signmask
<< (prec
- count
);
510 /* Rotate the doubleword integer in L1, H1 left by COUNT places
511 keeping only PREC bits of result.
512 Rotate right if COUNT is negative.
513 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
516 lrotate_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
517 HOST_WIDE_INT count
, unsigned int prec
,
518 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
520 unsigned HOST_WIDE_INT s1l
, s2l
;
521 HOST_WIDE_INT s1h
, s2h
;
527 lshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
528 rshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
533 /* Rotate the doubleword integer in L1, H1 left by COUNT places
534 keeping only PREC bits of result. COUNT must be positive.
535 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
538 rrotate_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
539 HOST_WIDE_INT count
, unsigned int prec
,
540 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
542 unsigned HOST_WIDE_INT s1l
, s2l
;
543 HOST_WIDE_INT s1h
, s2h
;
549 rshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
550 lshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
555 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
556 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
557 CODE is a tree code for a kind of division, one of
558 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
560 It controls how the quotient is rounded to an integer.
561 Return nonzero if the operation overflows.
562 UNS nonzero says do unsigned division. */
565 div_and_round_double (enum tree_code code
, int uns
,
566 unsigned HOST_WIDE_INT lnum_orig
, /* num == numerator == dividend */
567 HOST_WIDE_INT hnum_orig
,
568 unsigned HOST_WIDE_INT lden_orig
, /* den == denominator == divisor */
569 HOST_WIDE_INT hden_orig
,
570 unsigned HOST_WIDE_INT
*lquo
,
571 HOST_WIDE_INT
*hquo
, unsigned HOST_WIDE_INT
*lrem
,
575 HOST_WIDE_INT num
[4 + 1]; /* extra element for scaling. */
576 HOST_WIDE_INT den
[4], quo
[4];
578 unsigned HOST_WIDE_INT work
;
579 unsigned HOST_WIDE_INT carry
= 0;
580 unsigned HOST_WIDE_INT lnum
= lnum_orig
;
581 HOST_WIDE_INT hnum
= hnum_orig
;
582 unsigned HOST_WIDE_INT lden
= lden_orig
;
583 HOST_WIDE_INT hden
= hden_orig
;
586 if (hden
== 0 && lden
== 0)
587 overflow
= 1, lden
= 1;
589 /* Calculate quotient sign and convert operands to unsigned. */
595 /* (minimum integer) / (-1) is the only overflow case. */
596 if (neg_double (lnum
, hnum
, &lnum
, &hnum
)
597 && ((HOST_WIDE_INT
) lden
& hden
) == -1)
603 neg_double (lden
, hden
, &lden
, &hden
);
607 if (hnum
== 0 && hden
== 0)
608 { /* single precision */
610 /* This unsigned division rounds toward zero. */
616 { /* trivial case: dividend < divisor */
617 /* hden != 0 already checked. */
624 memset (quo
, 0, sizeof quo
);
626 memset (num
, 0, sizeof num
); /* to zero 9th element */
627 memset (den
, 0, sizeof den
);
629 encode (num
, lnum
, hnum
);
630 encode (den
, lden
, hden
);
632 /* Special code for when the divisor < BASE. */
633 if (hden
== 0 && lden
< (unsigned HOST_WIDE_INT
) BASE
)
635 /* hnum != 0 already checked. */
636 for (i
= 4 - 1; i
>= 0; i
--)
638 work
= num
[i
] + carry
* BASE
;
639 quo
[i
] = work
/ lden
;
645 /* Full double precision division,
646 with thanks to Don Knuth's "Seminumerical Algorithms". */
647 int num_hi_sig
, den_hi_sig
;
648 unsigned HOST_WIDE_INT quo_est
, scale
;
650 /* Find the highest nonzero divisor digit. */
651 for (i
= 4 - 1;; i
--)
658 /* Insure that the first digit of the divisor is at least BASE/2.
659 This is required by the quotient digit estimation algorithm. */
661 scale
= BASE
/ (den
[den_hi_sig
] + 1);
663 { /* scale divisor and dividend */
665 for (i
= 0; i
<= 4 - 1; i
++)
667 work
= (num
[i
] * scale
) + carry
;
668 num
[i
] = LOWPART (work
);
669 carry
= HIGHPART (work
);
674 for (i
= 0; i
<= 4 - 1; i
++)
676 work
= (den
[i
] * scale
) + carry
;
677 den
[i
] = LOWPART (work
);
678 carry
= HIGHPART (work
);
679 if (den
[i
] != 0) den_hi_sig
= i
;
686 for (i
= num_hi_sig
- den_hi_sig
- 1; i
>= 0; i
--)
688 /* Guess the next quotient digit, quo_est, by dividing the first
689 two remaining dividend digits by the high order quotient digit.
690 quo_est is never low and is at most 2 high. */
691 unsigned HOST_WIDE_INT tmp
;
693 num_hi_sig
= i
+ den_hi_sig
+ 1;
694 work
= num
[num_hi_sig
] * BASE
+ num
[num_hi_sig
- 1];
695 if (num
[num_hi_sig
] != den
[den_hi_sig
])
696 quo_est
= work
/ den
[den_hi_sig
];
700 /* Refine quo_est so it's usually correct, and at most one high. */
701 tmp
= work
- quo_est
* den
[den_hi_sig
];
703 && (den
[den_hi_sig
- 1] * quo_est
704 > (tmp
* BASE
+ num
[num_hi_sig
- 2])))
707 /* Try QUO_EST as the quotient digit, by multiplying the
708 divisor by QUO_EST and subtracting from the remaining dividend.
709 Keep in mind that QUO_EST is the I - 1st digit. */
712 for (j
= 0; j
<= den_hi_sig
; j
++)
714 work
= quo_est
* den
[j
] + carry
;
715 carry
= HIGHPART (work
);
716 work
= num
[i
+ j
] - LOWPART (work
);
717 num
[i
+ j
] = LOWPART (work
);
718 carry
+= HIGHPART (work
) != 0;
721 /* If quo_est was high by one, then num[i] went negative and
722 we need to correct things. */
723 if (num
[num_hi_sig
] < (HOST_WIDE_INT
) carry
)
726 carry
= 0; /* add divisor back in */
727 for (j
= 0; j
<= den_hi_sig
; j
++)
729 work
= num
[i
+ j
] + den
[j
] + carry
;
730 carry
= HIGHPART (work
);
731 num
[i
+ j
] = LOWPART (work
);
734 num
[num_hi_sig
] += carry
;
737 /* Store the quotient digit. */
742 decode (quo
, lquo
, hquo
);
745 /* If result is negative, make it so. */
747 neg_double (*lquo
, *hquo
, lquo
, hquo
);
749 /* Compute trial remainder: rem = num - (quo * den) */
750 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
751 neg_double (*lrem
, *hrem
, lrem
, hrem
);
752 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
757 case TRUNC_MOD_EXPR
: /* round toward zero */
758 case EXACT_DIV_EXPR
: /* for this one, it shouldn't matter */
762 case FLOOR_MOD_EXPR
: /* round toward negative infinity */
763 if (quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio < 0 && rem != 0 */
766 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1,
774 case CEIL_MOD_EXPR
: /* round toward positive infinity */
775 if (!quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio > 0 && rem != 0 */
777 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
785 case ROUND_MOD_EXPR
: /* round to closest integer */
787 unsigned HOST_WIDE_INT labs_rem
= *lrem
;
788 HOST_WIDE_INT habs_rem
= *hrem
;
789 unsigned HOST_WIDE_INT labs_den
= lden
, ltwice
;
790 HOST_WIDE_INT habs_den
= hden
, htwice
;
792 /* Get absolute values. */
794 neg_double (*lrem
, *hrem
, &labs_rem
, &habs_rem
);
796 neg_double (lden
, hden
, &labs_den
, &habs_den
);
798 /* If (2 * abs (lrem) >= abs (lden)) */
799 mul_double ((HOST_WIDE_INT
) 2, (HOST_WIDE_INT
) 0,
800 labs_rem
, habs_rem
, <wice
, &htwice
);
802 if (((unsigned HOST_WIDE_INT
) habs_den
803 < (unsigned HOST_WIDE_INT
) htwice
)
804 || (((unsigned HOST_WIDE_INT
) habs_den
805 == (unsigned HOST_WIDE_INT
) htwice
)
806 && (labs_den
< ltwice
)))
810 add_double (*lquo
, *hquo
,
811 (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1, lquo
, hquo
);
814 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
826 /* Compute true remainder: rem = num - (quo * den) */
827 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
828 neg_double (*lrem
, *hrem
, lrem
, hrem
);
829 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
833 /* If ARG2 divides ARG1 with zero remainder, carries out the division
834 of type CODE and returns the quotient.
835 Otherwise returns NULL_TREE. */
838 div_if_zero_remainder (enum tree_code code
, tree arg1
, tree arg2
)
840 unsigned HOST_WIDE_INT int1l
, int2l
;
841 HOST_WIDE_INT int1h
, int2h
;
842 unsigned HOST_WIDE_INT quol
, reml
;
843 HOST_WIDE_INT quoh
, remh
;
844 tree type
= TREE_TYPE (arg1
);
845 int uns
= TYPE_UNSIGNED (type
);
847 int1l
= TREE_INT_CST_LOW (arg1
);
848 int1h
= TREE_INT_CST_HIGH (arg1
);
849 int2l
= TREE_INT_CST_LOW (arg2
);
850 int2h
= TREE_INT_CST_HIGH (arg2
);
852 div_and_round_double (code
, uns
, int1l
, int1h
, int2l
, int2h
,
853 &quol
, &quoh
, &reml
, &remh
);
854 if (remh
!= 0 || reml
!= 0)
857 return build_int_cst_wide (type
, quol
, quoh
);
860 /* Return true if the built-in mathematical function specified by CODE
861 is odd, i.e. -f(x) == f(-x). */
864 negate_mathfn_p (enum built_in_function code
)
868 CASE_FLT_FN (BUILT_IN_ASIN
):
869 CASE_FLT_FN (BUILT_IN_ASINH
):
870 CASE_FLT_FN (BUILT_IN_ATAN
):
871 CASE_FLT_FN (BUILT_IN_ATANH
):
872 CASE_FLT_FN (BUILT_IN_CBRT
):
873 CASE_FLT_FN (BUILT_IN_SIN
):
874 CASE_FLT_FN (BUILT_IN_SINH
):
875 CASE_FLT_FN (BUILT_IN_TAN
):
876 CASE_FLT_FN (BUILT_IN_TANH
):
885 /* Check whether we may negate an integer constant T without causing
889 may_negate_without_overflow_p (tree t
)
891 unsigned HOST_WIDE_INT val
;
895 gcc_assert (TREE_CODE (t
) == INTEGER_CST
);
897 type
= TREE_TYPE (t
);
898 if (TYPE_UNSIGNED (type
))
901 prec
= TYPE_PRECISION (type
);
902 if (prec
> HOST_BITS_PER_WIDE_INT
)
904 if (TREE_INT_CST_LOW (t
) != 0)
906 prec
-= HOST_BITS_PER_WIDE_INT
;
907 val
= TREE_INT_CST_HIGH (t
);
910 val
= TREE_INT_CST_LOW (t
);
911 if (prec
< HOST_BITS_PER_WIDE_INT
)
912 val
&= ((unsigned HOST_WIDE_INT
) 1 << prec
) - 1;
913 return val
!= ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1));
916 /* Determine whether an expression T can be cheaply negated using
917 the function negate_expr. */
920 negate_expr_p (tree t
)
927 type
= TREE_TYPE (t
);
930 switch (TREE_CODE (t
))
933 if (TYPE_UNSIGNED (type
) || ! flag_trapv
)
936 /* Check that -CST will not overflow type. */
937 return may_negate_without_overflow_p (t
);
939 return INTEGRAL_TYPE_P (type
);
946 return negate_expr_p (TREE_REALPART (t
))
947 && negate_expr_p (TREE_IMAGPART (t
));
950 if (FLOAT_TYPE_P (type
) && !flag_unsafe_math_optimizations
)
952 /* -(A + B) -> (-B) - A. */
953 if (negate_expr_p (TREE_OPERAND (t
, 1))
954 && reorder_operands_p (TREE_OPERAND (t
, 0),
955 TREE_OPERAND (t
, 1)))
957 /* -(A + B) -> (-A) - B. */
958 return negate_expr_p (TREE_OPERAND (t
, 0));
961 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
962 return (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
963 && reorder_operands_p (TREE_OPERAND (t
, 0),
964 TREE_OPERAND (t
, 1));
967 if (TYPE_UNSIGNED (TREE_TYPE (t
)))
973 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t
))))
974 return negate_expr_p (TREE_OPERAND (t
, 1))
975 || negate_expr_p (TREE_OPERAND (t
, 0));
983 if (TYPE_UNSIGNED (TREE_TYPE (t
)) || flag_wrapv
)
985 return negate_expr_p (TREE_OPERAND (t
, 1))
986 || negate_expr_p (TREE_OPERAND (t
, 0));
989 /* Negate -((double)float) as (double)(-float). */
990 if (TREE_CODE (type
) == REAL_TYPE
)
992 tree tem
= strip_float_extensions (t
);
994 return negate_expr_p (tem
);
999 /* Negate -f(x) as f(-x). */
1000 if (negate_mathfn_p (builtin_mathfn_code (t
)))
1001 return negate_expr_p (TREE_VALUE (TREE_OPERAND (t
, 1)));
1005 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1006 if (TREE_CODE (TREE_OPERAND (t
, 1)) == INTEGER_CST
)
1008 tree op1
= TREE_OPERAND (t
, 1);
1009 if (TREE_INT_CST_HIGH (op1
) == 0
1010 && (unsigned HOST_WIDE_INT
) (TYPE_PRECISION (type
) - 1)
1011 == TREE_INT_CST_LOW (op1
))
1022 /* Given T, an expression, return the negation of T. Allow for T to be
1023 null, in which case return null. */
1026 negate_expr (tree t
)
1034 type
= TREE_TYPE (t
);
1035 STRIP_SIGN_NOPS (t
);
1037 switch (TREE_CODE (t
))
1039 /* Convert - (~A) to A + 1. */
1041 if (INTEGRAL_TYPE_P (type
))
1042 return fold_build2 (PLUS_EXPR
, type
, TREE_OPERAND (t
, 0),
1043 build_int_cst (type
, 1));
1047 tem
= fold_negate_const (t
, type
);
1048 if (! TREE_OVERFLOW (tem
)
1049 || TYPE_UNSIGNED (type
)
1055 tem
= fold_negate_const (t
, type
);
1056 /* Two's complement FP formats, such as c4x, may overflow. */
1057 if (! TREE_OVERFLOW (tem
) || ! flag_trapping_math
)
1058 return fold_convert (type
, tem
);
1063 tree rpart
= negate_expr (TREE_REALPART (t
));
1064 tree ipart
= negate_expr (TREE_IMAGPART (t
));
1066 if ((TREE_CODE (rpart
) == REAL_CST
1067 && TREE_CODE (ipart
) == REAL_CST
)
1068 || (TREE_CODE (rpart
) == INTEGER_CST
1069 && TREE_CODE (ipart
) == INTEGER_CST
))
1070 return build_complex (type
, rpart
, ipart
);
1075 return fold_convert (type
, TREE_OPERAND (t
, 0));
1078 if (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
1080 /* -(A + B) -> (-B) - A. */
1081 if (negate_expr_p (TREE_OPERAND (t
, 1))
1082 && reorder_operands_p (TREE_OPERAND (t
, 0),
1083 TREE_OPERAND (t
, 1)))
1085 tem
= negate_expr (TREE_OPERAND (t
, 1));
1086 tem
= fold_build2 (MINUS_EXPR
, TREE_TYPE (t
),
1087 tem
, TREE_OPERAND (t
, 0));
1088 return fold_convert (type
, tem
);
1091 /* -(A + B) -> (-A) - B. */
1092 if (negate_expr_p (TREE_OPERAND (t
, 0)))
1094 tem
= negate_expr (TREE_OPERAND (t
, 0));
1095 tem
= fold_build2 (MINUS_EXPR
, TREE_TYPE (t
),
1096 tem
, TREE_OPERAND (t
, 1));
1097 return fold_convert (type
, tem
);
1103 /* - (A - B) -> B - A */
1104 if ((! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
1105 && reorder_operands_p (TREE_OPERAND (t
, 0), TREE_OPERAND (t
, 1)))
1106 return fold_convert (type
,
1107 fold_build2 (MINUS_EXPR
, TREE_TYPE (t
),
1108 TREE_OPERAND (t
, 1),
1109 TREE_OPERAND (t
, 0)));
1113 if (TYPE_UNSIGNED (TREE_TYPE (t
)))
1119 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t
))))
1121 tem
= TREE_OPERAND (t
, 1);
1122 if (negate_expr_p (tem
))
1123 return fold_convert (type
,
1124 fold_build2 (TREE_CODE (t
), TREE_TYPE (t
),
1125 TREE_OPERAND (t
, 0),
1126 negate_expr (tem
)));
1127 tem
= TREE_OPERAND (t
, 0);
1128 if (negate_expr_p (tem
))
1129 return fold_convert (type
,
1130 fold_build2 (TREE_CODE (t
), TREE_TYPE (t
),
1132 TREE_OPERAND (t
, 1)));
1136 case TRUNC_DIV_EXPR
:
1137 case ROUND_DIV_EXPR
:
1138 case FLOOR_DIV_EXPR
:
1140 case EXACT_DIV_EXPR
:
1141 if (!TYPE_UNSIGNED (TREE_TYPE (t
)) && !flag_wrapv
)
1143 tem
= TREE_OPERAND (t
, 1);
1144 if (negate_expr_p (tem
))
1145 return fold_convert (type
,
1146 fold_build2 (TREE_CODE (t
), TREE_TYPE (t
),
1147 TREE_OPERAND (t
, 0),
1148 negate_expr (tem
)));
1149 tem
= TREE_OPERAND (t
, 0);
1150 if (negate_expr_p (tem
))
1151 return fold_convert (type
,
1152 fold_build2 (TREE_CODE (t
), TREE_TYPE (t
),
1154 TREE_OPERAND (t
, 1)));
1159 /* Convert -((double)float) into (double)(-float). */
1160 if (TREE_CODE (type
) == REAL_TYPE
)
1162 tem
= strip_float_extensions (t
);
1163 if (tem
!= t
&& negate_expr_p (tem
))
1164 return fold_convert (type
, negate_expr (tem
));
1169 /* Negate -f(x) as f(-x). */
1170 if (negate_mathfn_p (builtin_mathfn_code (t
))
1171 && negate_expr_p (TREE_VALUE (TREE_OPERAND (t
, 1))))
1173 tree fndecl
, arg
, arglist
;
1175 fndecl
= get_callee_fndecl (t
);
1176 arg
= negate_expr (TREE_VALUE (TREE_OPERAND (t
, 1)));
1177 arglist
= build_tree_list (NULL_TREE
, arg
);
1178 return build_function_call_expr (fndecl
, arglist
);
1183 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1184 if (TREE_CODE (TREE_OPERAND (t
, 1)) == INTEGER_CST
)
1186 tree op1
= TREE_OPERAND (t
, 1);
1187 if (TREE_INT_CST_HIGH (op1
) == 0
1188 && (unsigned HOST_WIDE_INT
) (TYPE_PRECISION (type
) - 1)
1189 == TREE_INT_CST_LOW (op1
))
1191 tree ntype
= TYPE_UNSIGNED (type
)
1192 ? lang_hooks
.types
.signed_type (type
)
1193 : lang_hooks
.types
.unsigned_type (type
);
1194 tree temp
= fold_convert (ntype
, TREE_OPERAND (t
, 0));
1195 temp
= fold_build2 (RSHIFT_EXPR
, ntype
, temp
, op1
);
1196 return fold_convert (type
, temp
);
1205 tem
= fold_build1 (NEGATE_EXPR
, TREE_TYPE (t
), t
);
1206 return fold_convert (type
, tem
);
1209 /* Split a tree IN into a constant, literal and variable parts that could be
1210 combined with CODE to make IN. "constant" means an expression with
1211 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1212 commutative arithmetic operation. Store the constant part into *CONP,
1213 the literal in *LITP and return the variable part. If a part isn't
1214 present, set it to null. If the tree does not decompose in this way,
1215 return the entire tree as the variable part and the other parts as null.
1217 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1218 case, we negate an operand that was subtracted. Except if it is a
1219 literal for which we use *MINUS_LITP instead.
1221 If NEGATE_P is true, we are negating all of IN, again except a literal
1222 for which we use *MINUS_LITP instead.
1224 If IN is itself a literal or constant, return it as appropriate.
1226 Note that we do not guarantee that any of the three values will be the
1227 same type as IN, but they will have the same signedness and mode. */
1230 split_tree (tree in
, enum tree_code code
, tree
*conp
, tree
*litp
,
1231 tree
*minus_litp
, int negate_p
)
1239 /* Strip any conversions that don't change the machine mode or signedness. */
1240 STRIP_SIGN_NOPS (in
);
1242 if (TREE_CODE (in
) == INTEGER_CST
|| TREE_CODE (in
) == REAL_CST
)
1244 else if (TREE_CODE (in
) == code
1245 || (! FLOAT_TYPE_P (TREE_TYPE (in
))
1246 /* We can associate addition and subtraction together (even
1247 though the C standard doesn't say so) for integers because
1248 the value is not affected. For reals, the value might be
1249 affected, so we can't. */
1250 && ((code
== PLUS_EXPR
&& TREE_CODE (in
) == MINUS_EXPR
)
1251 || (code
== MINUS_EXPR
&& TREE_CODE (in
) == PLUS_EXPR
))))
1253 tree op0
= TREE_OPERAND (in
, 0);
1254 tree op1
= TREE_OPERAND (in
, 1);
1255 int neg1_p
= TREE_CODE (in
) == MINUS_EXPR
;
1256 int neg_litp_p
= 0, neg_conp_p
= 0, neg_var_p
= 0;
1258 /* First see if either of the operands is a literal, then a constant. */
1259 if (TREE_CODE (op0
) == INTEGER_CST
|| TREE_CODE (op0
) == REAL_CST
)
1260 *litp
= op0
, op0
= 0;
1261 else if (TREE_CODE (op1
) == INTEGER_CST
|| TREE_CODE (op1
) == REAL_CST
)
1262 *litp
= op1
, neg_litp_p
= neg1_p
, op1
= 0;
1264 if (op0
!= 0 && TREE_CONSTANT (op0
))
1265 *conp
= op0
, op0
= 0;
1266 else if (op1
!= 0 && TREE_CONSTANT (op1
))
1267 *conp
= op1
, neg_conp_p
= neg1_p
, op1
= 0;
1269 /* If we haven't dealt with either operand, this is not a case we can
1270 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1271 if (op0
!= 0 && op1
!= 0)
1276 var
= op1
, neg_var_p
= neg1_p
;
1278 /* Now do any needed negations. */
1280 *minus_litp
= *litp
, *litp
= 0;
1282 *conp
= negate_expr (*conp
);
1284 var
= negate_expr (var
);
1286 else if (TREE_CONSTANT (in
))
1294 *minus_litp
= *litp
, *litp
= 0;
1295 else if (*minus_litp
)
1296 *litp
= *minus_litp
, *minus_litp
= 0;
1297 *conp
= negate_expr (*conp
);
1298 var
= negate_expr (var
);
1304 /* Re-associate trees split by the above function. T1 and T2 are either
1305 expressions to associate or null. Return the new expression, if any. If
1306 we build an operation, do it in TYPE and with CODE. */
1309 associate_trees (tree t1
, tree t2
, enum tree_code code
, tree type
)
1316 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1317 try to fold this since we will have infinite recursion. But do
1318 deal with any NEGATE_EXPRs. */
1319 if (TREE_CODE (t1
) == code
|| TREE_CODE (t2
) == code
1320 || TREE_CODE (t1
) == MINUS_EXPR
|| TREE_CODE (t2
) == MINUS_EXPR
)
1322 if (code
== PLUS_EXPR
)
1324 if (TREE_CODE (t1
) == NEGATE_EXPR
)
1325 return build2 (MINUS_EXPR
, type
, fold_convert (type
, t2
),
1326 fold_convert (type
, TREE_OPERAND (t1
, 0)));
1327 else if (TREE_CODE (t2
) == NEGATE_EXPR
)
1328 return build2 (MINUS_EXPR
, type
, fold_convert (type
, t1
),
1329 fold_convert (type
, TREE_OPERAND (t2
, 0)));
1330 else if (integer_zerop (t2
))
1331 return fold_convert (type
, t1
);
1333 else if (code
== MINUS_EXPR
)
1335 if (integer_zerop (t2
))
1336 return fold_convert (type
, t1
);
1339 return build2 (code
, type
, fold_convert (type
, t1
),
1340 fold_convert (type
, t2
));
1343 return fold_build2 (code
, type
, fold_convert (type
, t1
),
1344 fold_convert (type
, t2
));
1347 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1348 to produce a new constant. Return NULL_TREE if we don't know how
1349 to evaluate CODE at compile-time.
1351 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1354 int_const_binop (enum tree_code code
, tree arg1
, tree arg2
, int notrunc
)
1356 unsigned HOST_WIDE_INT int1l
, int2l
;
1357 HOST_WIDE_INT int1h
, int2h
;
1358 unsigned HOST_WIDE_INT low
;
1360 unsigned HOST_WIDE_INT garbagel
;
1361 HOST_WIDE_INT garbageh
;
1363 tree type
= TREE_TYPE (arg1
);
1364 int uns
= TYPE_UNSIGNED (type
);
1366 = (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
));
1369 int1l
= TREE_INT_CST_LOW (arg1
);
1370 int1h
= TREE_INT_CST_HIGH (arg1
);
1371 int2l
= TREE_INT_CST_LOW (arg2
);
1372 int2h
= TREE_INT_CST_HIGH (arg2
);
1377 low
= int1l
| int2l
, hi
= int1h
| int2h
;
1381 low
= int1l
^ int2l
, hi
= int1h
^ int2h
;
1385 low
= int1l
& int2l
, hi
= int1h
& int2h
;
1391 /* It's unclear from the C standard whether shifts can overflow.
1392 The following code ignores overflow; perhaps a C standard
1393 interpretation ruling is needed. */
1394 lshift_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1401 lrotate_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1406 overflow
= add_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1410 neg_double (int2l
, int2h
, &low
, &hi
);
1411 add_double (int1l
, int1h
, low
, hi
, &low
, &hi
);
1412 overflow
= OVERFLOW_SUM_SIGN (hi
, int2h
, int1h
);
1416 overflow
= mul_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1419 case TRUNC_DIV_EXPR
:
1420 case FLOOR_DIV_EXPR
: case CEIL_DIV_EXPR
:
1421 case EXACT_DIV_EXPR
:
1422 /* This is a shortcut for a common special case. */
1423 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1424 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1425 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1426 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1428 if (code
== CEIL_DIV_EXPR
)
1431 low
= int1l
/ int2l
, hi
= 0;
1435 /* ... fall through ... */
1437 case ROUND_DIV_EXPR
:
1438 if (int2h
== 0 && int2l
== 0)
1440 if (int2h
== 0 && int2l
== 1)
1442 low
= int1l
, hi
= int1h
;
1445 if (int1l
== int2l
&& int1h
== int2h
1446 && ! (int1l
== 0 && int1h
== 0))
1451 overflow
= div_and_round_double (code
, uns
, int1l
, int1h
, int2l
, int2h
,
1452 &low
, &hi
, &garbagel
, &garbageh
);
1455 case TRUNC_MOD_EXPR
:
1456 case FLOOR_MOD_EXPR
: case CEIL_MOD_EXPR
:
1457 /* This is a shortcut for a common special case. */
1458 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1459 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1460 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1461 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1463 if (code
== CEIL_MOD_EXPR
)
1465 low
= int1l
% int2l
, hi
= 0;
1469 /* ... fall through ... */
1471 case ROUND_MOD_EXPR
:
1472 if (int2h
== 0 && int2l
== 0)
1474 overflow
= div_and_round_double (code
, uns
,
1475 int1l
, int1h
, int2l
, int2h
,
1476 &garbagel
, &garbageh
, &low
, &hi
);
1482 low
= (((unsigned HOST_WIDE_INT
) int1h
1483 < (unsigned HOST_WIDE_INT
) int2h
)
1484 || (((unsigned HOST_WIDE_INT
) int1h
1485 == (unsigned HOST_WIDE_INT
) int2h
)
1488 low
= (int1h
< int2h
1489 || (int1h
== int2h
&& int1l
< int2l
));
1491 if (low
== (code
== MIN_EXPR
))
1492 low
= int1l
, hi
= int1h
;
1494 low
= int2l
, hi
= int2h
;
1501 t
= build_int_cst_wide (TREE_TYPE (arg1
), low
, hi
);
1505 /* Propagate overflow flags ourselves. */
1506 if (((!uns
|| is_sizetype
) && overflow
)
1507 | TREE_OVERFLOW (arg1
) | TREE_OVERFLOW (arg2
))
1510 TREE_OVERFLOW (t
) = 1;
1511 TREE_CONSTANT_OVERFLOW (t
) = 1;
1513 else if (TREE_CONSTANT_OVERFLOW (arg1
) | TREE_CONSTANT_OVERFLOW (arg2
))
1516 TREE_CONSTANT_OVERFLOW (t
) = 1;
1520 t
= force_fit_type (t
, 1,
1521 ((!uns
|| is_sizetype
) && overflow
)
1522 | TREE_OVERFLOW (arg1
) | TREE_OVERFLOW (arg2
),
1523 TREE_CONSTANT_OVERFLOW (arg1
)
1524 | TREE_CONSTANT_OVERFLOW (arg2
));
1529 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1530 constant. We assume ARG1 and ARG2 have the same data type, or at least
1531 are the same kind of constant and the same machine mode.
1533 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1536 const_binop (enum tree_code code
, tree arg1
, tree arg2
, int notrunc
)
1541 if (TREE_CODE (arg1
) == INTEGER_CST
)
1542 return int_const_binop (code
, arg1
, arg2
, notrunc
);
1544 if (TREE_CODE (arg1
) == REAL_CST
)
1546 enum machine_mode mode
;
1549 REAL_VALUE_TYPE value
;
1550 REAL_VALUE_TYPE result
;
1554 /* The following codes are handled by real_arithmetic. */
1569 d1
= TREE_REAL_CST (arg1
);
1570 d2
= TREE_REAL_CST (arg2
);
1572 type
= TREE_TYPE (arg1
);
1573 mode
= TYPE_MODE (type
);
1575 /* Don't perform operation if we honor signaling NaNs and
1576 either operand is a NaN. */
1577 if (HONOR_SNANS (mode
)
1578 && (REAL_VALUE_ISNAN (d1
) || REAL_VALUE_ISNAN (d2
)))
1581 /* Don't perform operation if it would raise a division
1582 by zero exception. */
1583 if (code
== RDIV_EXPR
1584 && REAL_VALUES_EQUAL (d2
, dconst0
)
1585 && (flag_trapping_math
|| ! MODE_HAS_INFINITIES (mode
)))
1588 /* If either operand is a NaN, just return it. Otherwise, set up
1589 for floating-point trap; we return an overflow. */
1590 if (REAL_VALUE_ISNAN (d1
))
1592 else if (REAL_VALUE_ISNAN (d2
))
1595 inexact
= real_arithmetic (&value
, code
, &d1
, &d2
);
1596 real_convert (&result
, mode
, &value
);
1598 /* Don't constant fold this floating point operation if
1599 the result has overflowed and flag_trapping_math. */
1601 if (flag_trapping_math
1602 && MODE_HAS_INFINITIES (mode
)
1603 && REAL_VALUE_ISINF (result
)
1604 && !REAL_VALUE_ISINF (d1
)
1605 && !REAL_VALUE_ISINF (d2
))
1608 /* Don't constant fold this floating point operation if the
1609 result may dependent upon the run-time rounding mode and
1610 flag_rounding_math is set, or if GCC's software emulation
1611 is unable to accurately represent the result. */
1613 if ((flag_rounding_math
1614 || (REAL_MODE_FORMAT_COMPOSITE_P (mode
)
1615 && !flag_unsafe_math_optimizations
))
1616 && (inexact
|| !real_identical (&result
, &value
)))
1619 t
= build_real (type
, result
);
1621 TREE_OVERFLOW (t
) = TREE_OVERFLOW (arg1
) | TREE_OVERFLOW (arg2
);
1622 TREE_CONSTANT_OVERFLOW (t
)
1624 | TREE_CONSTANT_OVERFLOW (arg1
)
1625 | TREE_CONSTANT_OVERFLOW (arg2
);
1629 if (TREE_CODE (arg1
) == COMPLEX_CST
)
1631 tree type
= TREE_TYPE (arg1
);
1632 tree r1
= TREE_REALPART (arg1
);
1633 tree i1
= TREE_IMAGPART (arg1
);
1634 tree r2
= TREE_REALPART (arg2
);
1635 tree i2
= TREE_IMAGPART (arg2
);
1641 t
= build_complex (type
,
1642 const_binop (PLUS_EXPR
, r1
, r2
, notrunc
),
1643 const_binop (PLUS_EXPR
, i1
, i2
, notrunc
));
1647 t
= build_complex (type
,
1648 const_binop (MINUS_EXPR
, r1
, r2
, notrunc
),
1649 const_binop (MINUS_EXPR
, i1
, i2
, notrunc
));
1653 t
= build_complex (type
,
1654 const_binop (MINUS_EXPR
,
1655 const_binop (MULT_EXPR
,
1657 const_binop (MULT_EXPR
,
1660 const_binop (PLUS_EXPR
,
1661 const_binop (MULT_EXPR
,
1663 const_binop (MULT_EXPR
,
1670 tree t1
, t2
, real
, imag
;
1672 = const_binop (PLUS_EXPR
,
1673 const_binop (MULT_EXPR
, r2
, r2
, notrunc
),
1674 const_binop (MULT_EXPR
, i2
, i2
, notrunc
),
1677 t1
= const_binop (PLUS_EXPR
,
1678 const_binop (MULT_EXPR
, r1
, r2
, notrunc
),
1679 const_binop (MULT_EXPR
, i1
, i2
, notrunc
),
1681 t2
= const_binop (MINUS_EXPR
,
1682 const_binop (MULT_EXPR
, i1
, r2
, notrunc
),
1683 const_binop (MULT_EXPR
, r1
, i2
, notrunc
),
1686 if (INTEGRAL_TYPE_P (TREE_TYPE (r1
)))
1688 real
= const_binop (TRUNC_DIV_EXPR
, t1
, magsquared
, notrunc
);
1689 imag
= const_binop (TRUNC_DIV_EXPR
, t2
, magsquared
, notrunc
);
1693 real
= const_binop (RDIV_EXPR
, t1
, magsquared
, notrunc
);
1694 imag
= const_binop (RDIV_EXPR
, t2
, magsquared
, notrunc
);
1699 t
= build_complex (type
, real
, imag
);
1711 /* Create a size type INT_CST node with NUMBER sign extended. KIND
1712 indicates which particular sizetype to create. */
1715 size_int_kind (HOST_WIDE_INT number
, enum size_type_kind kind
)
1717 return build_int_cst (sizetype_tab
[(int) kind
], number
);
1720 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1721 is a tree code. The type of the result is taken from the operands.
1722 Both must be the same type integer type and it must be a size type.
1723 If the operands are constant, so is the result. */
1726 size_binop (enum tree_code code
, tree arg0
, tree arg1
)
1728 tree type
= TREE_TYPE (arg0
);
1730 gcc_assert (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
)
1731 && type
== TREE_TYPE (arg1
));
1733 /* Handle the special case of two integer constants faster. */
1734 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
1736 /* And some specific cases even faster than that. */
1737 if (code
== PLUS_EXPR
&& integer_zerop (arg0
))
1739 else if ((code
== MINUS_EXPR
|| code
== PLUS_EXPR
)
1740 && integer_zerop (arg1
))
1742 else if (code
== MULT_EXPR
&& integer_onep (arg0
))
1745 /* Handle general case of two integer constants. */
1746 return int_const_binop (code
, arg0
, arg1
, 0);
1749 if (arg0
== error_mark_node
|| arg1
== error_mark_node
)
1750 return error_mark_node
;
1752 return fold_build2 (code
, type
, arg0
, arg1
);
1755 /* Given two values, either both of sizetype or both of bitsizetype,
1756 compute the difference between the two values. Return the value
1757 in signed type corresponding to the type of the operands. */
1760 size_diffop (tree arg0
, tree arg1
)
1762 tree type
= TREE_TYPE (arg0
);
1765 gcc_assert (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
)
1766 && type
== TREE_TYPE (arg1
));
1768 /* If the type is already signed, just do the simple thing. */
1769 if (!TYPE_UNSIGNED (type
))
1770 return size_binop (MINUS_EXPR
, arg0
, arg1
);
1772 ctype
= type
== bitsizetype
? sbitsizetype
: ssizetype
;
1774 /* If either operand is not a constant, do the conversions to the signed
1775 type and subtract. The hardware will do the right thing with any
1776 overflow in the subtraction. */
1777 if (TREE_CODE (arg0
) != INTEGER_CST
|| TREE_CODE (arg1
) != INTEGER_CST
)
1778 return size_binop (MINUS_EXPR
, fold_convert (ctype
, arg0
),
1779 fold_convert (ctype
, arg1
));
1781 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1782 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1783 overflow) and negate (which can't either). Special-case a result
1784 of zero while we're here. */
1785 if (tree_int_cst_equal (arg0
, arg1
))
1786 return build_int_cst (ctype
, 0);
1787 else if (tree_int_cst_lt (arg1
, arg0
))
1788 return fold_convert (ctype
, size_binop (MINUS_EXPR
, arg0
, arg1
));
1790 return size_binop (MINUS_EXPR
, build_int_cst (ctype
, 0),
1791 fold_convert (ctype
, size_binop (MINUS_EXPR
,
1795 /* A subroutine of fold_convert_const handling conversions of an
1796 INTEGER_CST to another integer type. */
1799 fold_convert_const_int_from_int (tree type
, tree arg1
)
1803 /* Given an integer constant, make new constant with new type,
1804 appropriately sign-extended or truncated. */
1805 t
= build_int_cst_wide (type
, TREE_INT_CST_LOW (arg1
),
1806 TREE_INT_CST_HIGH (arg1
));
1808 t
= force_fit_type (t
,
1809 /* Don't set the overflow when
1810 converting a pointer */
1811 !POINTER_TYPE_P (TREE_TYPE (arg1
)),
1812 (TREE_INT_CST_HIGH (arg1
) < 0
1813 && (TYPE_UNSIGNED (type
)
1814 < TYPE_UNSIGNED (TREE_TYPE (arg1
))))
1815 | TREE_OVERFLOW (arg1
),
1816 TREE_CONSTANT_OVERFLOW (arg1
));
1821 /* A subroutine of fold_convert_const handling conversions a REAL_CST
1822 to an integer type. */
1825 fold_convert_const_int_from_real (enum tree_code code
, tree type
, tree arg1
)
1830 /* The following code implements the floating point to integer
1831 conversion rules required by the Java Language Specification,
1832 that IEEE NaNs are mapped to zero and values that overflow
1833 the target precision saturate, i.e. values greater than
1834 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1835 are mapped to INT_MIN. These semantics are allowed by the
1836 C and C++ standards that simply state that the behavior of
1837 FP-to-integer conversion is unspecified upon overflow. */
1839 HOST_WIDE_INT high
, low
;
1841 REAL_VALUE_TYPE x
= TREE_REAL_CST (arg1
);
1845 case FIX_TRUNC_EXPR
:
1846 real_trunc (&r
, VOIDmode
, &x
);
1850 real_ceil (&r
, VOIDmode
, &x
);
1853 case FIX_FLOOR_EXPR
:
1854 real_floor (&r
, VOIDmode
, &x
);
1857 case FIX_ROUND_EXPR
:
1858 real_round (&r
, VOIDmode
, &x
);
1865 /* If R is NaN, return zero and show we have an overflow. */
1866 if (REAL_VALUE_ISNAN (r
))
1873 /* See if R is less than the lower bound or greater than the
1878 tree lt
= TYPE_MIN_VALUE (type
);
1879 REAL_VALUE_TYPE l
= real_value_from_int_cst (NULL_TREE
, lt
);
1880 if (REAL_VALUES_LESS (r
, l
))
1883 high
= TREE_INT_CST_HIGH (lt
);
1884 low
= TREE_INT_CST_LOW (lt
);
1890 tree ut
= TYPE_MAX_VALUE (type
);
1893 REAL_VALUE_TYPE u
= real_value_from_int_cst (NULL_TREE
, ut
);
1894 if (REAL_VALUES_LESS (u
, r
))
1897 high
= TREE_INT_CST_HIGH (ut
);
1898 low
= TREE_INT_CST_LOW (ut
);
1904 REAL_VALUE_TO_INT (&low
, &high
, r
);
1906 t
= build_int_cst_wide (type
, low
, high
);
1908 t
= force_fit_type (t
, -1, overflow
| TREE_OVERFLOW (arg1
),
1909 TREE_CONSTANT_OVERFLOW (arg1
));
1913 /* A subroutine of fold_convert_const handling conversions a REAL_CST
1914 to another floating point type. */
1917 fold_convert_const_real_from_real (tree type
, tree arg1
)
1919 REAL_VALUE_TYPE value
;
1922 real_convert (&value
, TYPE_MODE (type
), &TREE_REAL_CST (arg1
));
1923 t
= build_real (type
, value
);
1925 TREE_OVERFLOW (t
) = TREE_OVERFLOW (arg1
);
1926 TREE_CONSTANT_OVERFLOW (t
)
1927 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1931 /* Attempt to fold type conversion operation CODE of expression ARG1 to
1932 type TYPE. If no simplification can be done return NULL_TREE. */
1935 fold_convert_const (enum tree_code code
, tree type
, tree arg1
)
1937 if (TREE_TYPE (arg1
) == type
)
1940 if (POINTER_TYPE_P (type
) || INTEGRAL_TYPE_P (type
))
1942 if (TREE_CODE (arg1
) == INTEGER_CST
)
1943 return fold_convert_const_int_from_int (type
, arg1
);
1944 else if (TREE_CODE (arg1
) == REAL_CST
)
1945 return fold_convert_const_int_from_real (code
, type
, arg1
);
1947 else if (TREE_CODE (type
) == REAL_TYPE
)
1949 if (TREE_CODE (arg1
) == INTEGER_CST
)
1950 return build_real_from_int_cst (type
, arg1
);
1951 if (TREE_CODE (arg1
) == REAL_CST
)
1952 return fold_convert_const_real_from_real (type
, arg1
);
1957 /* Construct a vector of zero elements of vector type TYPE. */
1960 build_zero_vector (tree type
)
1965 elem
= fold_convert_const (NOP_EXPR
, TREE_TYPE (type
), integer_zero_node
);
1966 units
= TYPE_VECTOR_SUBPARTS (type
);
1969 for (i
= 0; i
< units
; i
++)
1970 list
= tree_cons (NULL_TREE
, elem
, list
);
1971 return build_vector (type
, list
);
1974 /* Convert expression ARG to type TYPE. Used by the middle-end for
1975 simple conversions in preference to calling the front-end's convert. */
1978 fold_convert (tree type
, tree arg
)
1980 tree orig
= TREE_TYPE (arg
);
1986 if (TREE_CODE (arg
) == ERROR_MARK
1987 || TREE_CODE (type
) == ERROR_MARK
1988 || TREE_CODE (orig
) == ERROR_MARK
)
1989 return error_mark_node
;
1991 if (TYPE_MAIN_VARIANT (type
) == TYPE_MAIN_VARIANT (orig
)
1992 || lang_hooks
.types_compatible_p (TYPE_MAIN_VARIANT (type
),
1993 TYPE_MAIN_VARIANT (orig
)))
1994 return fold_build1 (NOP_EXPR
, type
, arg
);
1996 switch (TREE_CODE (type
))
1998 case INTEGER_TYPE
: case CHAR_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
1999 case POINTER_TYPE
: case REFERENCE_TYPE
:
2001 if (TREE_CODE (arg
) == INTEGER_CST
)
2003 tem
= fold_convert_const (NOP_EXPR
, type
, arg
);
2004 if (tem
!= NULL_TREE
)
2007 if (INTEGRAL_TYPE_P (orig
) || POINTER_TYPE_P (orig
)
2008 || TREE_CODE (orig
) == OFFSET_TYPE
)
2009 return fold_build1 (NOP_EXPR
, type
, arg
);
2010 if (TREE_CODE (orig
) == COMPLEX_TYPE
)
2012 tem
= fold_build1 (REALPART_EXPR
, TREE_TYPE (orig
), arg
);
2013 return fold_convert (type
, tem
);
2015 gcc_assert (TREE_CODE (orig
) == VECTOR_TYPE
2016 && tree_int_cst_equal (TYPE_SIZE (type
), TYPE_SIZE (orig
)));
2017 return fold_build1 (NOP_EXPR
, type
, arg
);
2020 if (TREE_CODE (arg
) == INTEGER_CST
)
2022 tem
= fold_convert_const (FLOAT_EXPR
, type
, arg
);
2023 if (tem
!= NULL_TREE
)
2026 else if (TREE_CODE (arg
) == REAL_CST
)
2028 tem
= fold_convert_const (NOP_EXPR
, type
, arg
);
2029 if (tem
!= NULL_TREE
)
2033 switch (TREE_CODE (orig
))
2035 case INTEGER_TYPE
: case CHAR_TYPE
:
2036 case BOOLEAN_TYPE
: case ENUMERAL_TYPE
:
2037 case POINTER_TYPE
: case REFERENCE_TYPE
:
2038 return fold_build1 (FLOAT_EXPR
, type
, arg
);
2041 return fold_build1 (NOP_EXPR
, type
, arg
);
2044 tem
= fold_build1 (REALPART_EXPR
, TREE_TYPE (orig
), arg
);
2045 return fold_convert (type
, tem
);
2052 switch (TREE_CODE (orig
))
2054 case INTEGER_TYPE
: case CHAR_TYPE
:
2055 case BOOLEAN_TYPE
: case ENUMERAL_TYPE
:
2056 case POINTER_TYPE
: case REFERENCE_TYPE
:
2058 return build2 (COMPLEX_EXPR
, type
,
2059 fold_convert (TREE_TYPE (type
), arg
),
2060 fold_convert (TREE_TYPE (type
), integer_zero_node
));
2065 if (TREE_CODE (arg
) == COMPLEX_EXPR
)
2067 rpart
= fold_convert (TREE_TYPE (type
), TREE_OPERAND (arg
, 0));
2068 ipart
= fold_convert (TREE_TYPE (type
), TREE_OPERAND (arg
, 1));
2069 return fold_build2 (COMPLEX_EXPR
, type
, rpart
, ipart
);
2072 arg
= save_expr (arg
);
2073 rpart
= fold_build1 (REALPART_EXPR
, TREE_TYPE (orig
), arg
);
2074 ipart
= fold_build1 (IMAGPART_EXPR
, TREE_TYPE (orig
), arg
);
2075 rpart
= fold_convert (TREE_TYPE (type
), rpart
);
2076 ipart
= fold_convert (TREE_TYPE (type
), ipart
);
2077 return fold_build2 (COMPLEX_EXPR
, type
, rpart
, ipart
);
2085 if (integer_zerop (arg
))
2086 return build_zero_vector (type
);
2087 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type
), TYPE_SIZE (orig
)));
2088 gcc_assert (INTEGRAL_TYPE_P (orig
) || POINTER_TYPE_P (orig
)
2089 || TREE_CODE (orig
) == VECTOR_TYPE
);
2090 return fold_build1 (VIEW_CONVERT_EXPR
, type
, arg
);
2093 return fold_build1 (NOP_EXPR
, type
, fold_ignored_result (arg
));
2100 /* Return false if expr can be assumed not to be an lvalue, true
2104 maybe_lvalue_p (tree x
)
2106 /* We only need to wrap lvalue tree codes. */
2107 switch (TREE_CODE (x
))
2118 case ALIGN_INDIRECT_REF
:
2119 case MISALIGNED_INDIRECT_REF
:
2121 case ARRAY_RANGE_REF
:
2127 case PREINCREMENT_EXPR
:
2128 case PREDECREMENT_EXPR
:
2130 case TRY_CATCH_EXPR
:
2131 case WITH_CLEANUP_EXPR
:
2142 /* Assume the worst for front-end tree codes. */
2143 if ((int)TREE_CODE (x
) >= NUM_TREE_CODES
)
2151 /* Return an expr equal to X but certainly not valid as an lvalue. */
2156 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2161 if (! maybe_lvalue_p (x
))
2163 return build1 (NON_LVALUE_EXPR
, TREE_TYPE (x
), x
);
2166 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2167 Zero means allow extended lvalues. */
2169 int pedantic_lvalues
;
2171 /* When pedantic, return an expr equal to X but certainly not valid as a
2172 pedantic lvalue. Otherwise, return X. */
2175 pedantic_non_lvalue (tree x
)
2177 if (pedantic_lvalues
)
2178 return non_lvalue (x
);
2183 /* Given a tree comparison code, return the code that is the logical inverse
2184 of the given code. It is not safe to do this for floating-point
2185 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2186 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2189 invert_tree_comparison (enum tree_code code
, bool honor_nans
)
2191 if (honor_nans
&& flag_trapping_math
)
2201 return honor_nans
? UNLE_EXPR
: LE_EXPR
;
2203 return honor_nans
? UNLT_EXPR
: LT_EXPR
;
2205 return honor_nans
? UNGE_EXPR
: GE_EXPR
;
2207 return honor_nans
? UNGT_EXPR
: GT_EXPR
;
2221 return UNORDERED_EXPR
;
2222 case UNORDERED_EXPR
:
2223 return ORDERED_EXPR
;
2229 /* Similar, but return the comparison that results if the operands are
2230 swapped. This is safe for floating-point. */
2233 swap_tree_comparison (enum tree_code code
)
2240 case UNORDERED_EXPR
:
2266 /* Convert a comparison tree code from an enum tree_code representation
2267 into a compcode bit-based encoding. This function is the inverse of
2268 compcode_to_comparison. */
2270 static enum comparison_code
2271 comparison_to_compcode (enum tree_code code
)
2288 return COMPCODE_ORD
;
2289 case UNORDERED_EXPR
:
2290 return COMPCODE_UNORD
;
2292 return COMPCODE_UNLT
;
2294 return COMPCODE_UNEQ
;
2296 return COMPCODE_UNLE
;
2298 return COMPCODE_UNGT
;
2300 return COMPCODE_LTGT
;
2302 return COMPCODE_UNGE
;
2308 /* Convert a compcode bit-based encoding of a comparison operator back
2309 to GCC's enum tree_code representation. This function is the
2310 inverse of comparison_to_compcode. */
2312 static enum tree_code
2313 compcode_to_comparison (enum comparison_code code
)
2330 return ORDERED_EXPR
;
2331 case COMPCODE_UNORD
:
2332 return UNORDERED_EXPR
;
2350 /* Return a tree for the comparison which is the combination of
2351 doing the AND or OR (depending on CODE) of the two operations LCODE
2352 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2353 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2354 if this makes the transformation invalid. */
2357 combine_comparisons (enum tree_code code
, enum tree_code lcode
,
2358 enum tree_code rcode
, tree truth_type
,
2359 tree ll_arg
, tree lr_arg
)
2361 bool honor_nans
= HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg
)));
2362 enum comparison_code lcompcode
= comparison_to_compcode (lcode
);
2363 enum comparison_code rcompcode
= comparison_to_compcode (rcode
);
2364 enum comparison_code compcode
;
2368 case TRUTH_AND_EXPR
: case TRUTH_ANDIF_EXPR
:
2369 compcode
= lcompcode
& rcompcode
;
2372 case TRUTH_OR_EXPR
: case TRUTH_ORIF_EXPR
:
2373 compcode
= lcompcode
| rcompcode
;
2382 /* Eliminate unordered comparisons, as well as LTGT and ORD
2383 which are not used unless the mode has NaNs. */
2384 compcode
&= ~COMPCODE_UNORD
;
2385 if (compcode
== COMPCODE_LTGT
)
2386 compcode
= COMPCODE_NE
;
2387 else if (compcode
== COMPCODE_ORD
)
2388 compcode
= COMPCODE_TRUE
;
2390 else if (flag_trapping_math
)
2392 /* Check that the original operation and the optimized ones will trap
2393 under the same condition. */
2394 bool ltrap
= (lcompcode
& COMPCODE_UNORD
) == 0
2395 && (lcompcode
!= COMPCODE_EQ
)
2396 && (lcompcode
!= COMPCODE_ORD
);
2397 bool rtrap
= (rcompcode
& COMPCODE_UNORD
) == 0
2398 && (rcompcode
!= COMPCODE_EQ
)
2399 && (rcompcode
!= COMPCODE_ORD
);
2400 bool trap
= (compcode
& COMPCODE_UNORD
) == 0
2401 && (compcode
!= COMPCODE_EQ
)
2402 && (compcode
!= COMPCODE_ORD
);
2404 /* In a short-circuited boolean expression the LHS might be
2405 such that the RHS, if evaluated, will never trap. For
2406 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2407 if neither x nor y is NaN. (This is a mixed blessing: for
2408 example, the expression above will never trap, hence
2409 optimizing it to x < y would be invalid). */
2410 if ((code
== TRUTH_ORIF_EXPR
&& (lcompcode
& COMPCODE_UNORD
))
2411 || (code
== TRUTH_ANDIF_EXPR
&& !(lcompcode
& COMPCODE_UNORD
)))
2414 /* If the comparison was short-circuited, and only the RHS
2415 trapped, we may now generate a spurious trap. */
2417 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
))
2420 /* If we changed the conditions that cause a trap, we lose. */
2421 if ((ltrap
|| rtrap
) != trap
)
2425 if (compcode
== COMPCODE_TRUE
)
2426 return constant_boolean_node (true, truth_type
);
2427 else if (compcode
== COMPCODE_FALSE
)
2428 return constant_boolean_node (false, truth_type
);
2430 return fold_build2 (compcode_to_comparison (compcode
),
2431 truth_type
, ll_arg
, lr_arg
);
2434 /* Return nonzero if CODE is a tree code that represents a truth value. */
2437 truth_value_p (enum tree_code code
)
2439 return (TREE_CODE_CLASS (code
) == tcc_comparison
2440 || code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
2441 || code
== TRUTH_OR_EXPR
|| code
== TRUTH_ORIF_EXPR
2442 || code
== TRUTH_XOR_EXPR
|| code
== TRUTH_NOT_EXPR
);
2445 /* Return nonzero if two operands (typically of the same tree node)
2446 are necessarily equal. If either argument has side-effects this
2447 function returns zero. FLAGS modifies behavior as follows:
2449 If OEP_ONLY_CONST is set, only return nonzero for constants.
2450 This function tests whether the operands are indistinguishable;
2451 it does not test whether they are equal using C's == operation.
2452 The distinction is important for IEEE floating point, because
2453 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2454 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2456 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2457 even though it may hold multiple values during a function.
2458 This is because a GCC tree node guarantees that nothing else is
2459 executed between the evaluation of its "operands" (which may often
2460 be evaluated in arbitrary order). Hence if the operands themselves
2461 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2462 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2463 unset means assuming isochronic (or instantaneous) tree equivalence.
2464 Unless comparing arbitrary expression trees, such as from different
2465 statements, this flag can usually be left unset.
2467 If OEP_PURE_SAME is set, then pure functions with identical arguments
2468 are considered the same. It is used when the caller has other ways
2469 to ensure that global memory is unchanged in between. */
2472 operand_equal_p (tree arg0
, tree arg1
, unsigned int flags
)
2474 /* If either is ERROR_MARK, they aren't equal. */
2475 if (TREE_CODE (arg0
) == ERROR_MARK
|| TREE_CODE (arg1
) == ERROR_MARK
)
2478 /* If both types don't have the same signedness, then we can't consider
2479 them equal. We must check this before the STRIP_NOPS calls
2480 because they may change the signedness of the arguments. */
2481 if (TYPE_UNSIGNED (TREE_TYPE (arg0
)) != TYPE_UNSIGNED (TREE_TYPE (arg1
)))
2487 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
2488 /* This is needed for conversions and for COMPONENT_REF.
2489 Might as well play it safe and always test this. */
2490 || TREE_CODE (TREE_TYPE (arg0
)) == ERROR_MARK
2491 || TREE_CODE (TREE_TYPE (arg1
)) == ERROR_MARK
2492 || TYPE_MODE (TREE_TYPE (arg0
)) != TYPE_MODE (TREE_TYPE (arg1
)))
2495 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2496 We don't care about side effects in that case because the SAVE_EXPR
2497 takes care of that for us. In all other cases, two expressions are
2498 equal if they have no side effects. If we have two identical
2499 expressions with side effects that should be treated the same due
2500 to the only side effects being identical SAVE_EXPR's, that will
2501 be detected in the recursive calls below. */
2502 if (arg0
== arg1
&& ! (flags
& OEP_ONLY_CONST
)
2503 && (TREE_CODE (arg0
) == SAVE_EXPR
2504 || (! TREE_SIDE_EFFECTS (arg0
) && ! TREE_SIDE_EFFECTS (arg1
))))
2507 /* Next handle constant cases, those for which we can return 1 even
2508 if ONLY_CONST is set. */
2509 if (TREE_CONSTANT (arg0
) && TREE_CONSTANT (arg1
))
2510 switch (TREE_CODE (arg0
))
2513 return (! TREE_CONSTANT_OVERFLOW (arg0
)
2514 && ! TREE_CONSTANT_OVERFLOW (arg1
)
2515 && tree_int_cst_equal (arg0
, arg1
));
2518 return (! TREE_CONSTANT_OVERFLOW (arg0
)
2519 && ! TREE_CONSTANT_OVERFLOW (arg1
)
2520 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0
),
2521 TREE_REAL_CST (arg1
)));
2527 if (TREE_CONSTANT_OVERFLOW (arg0
)
2528 || TREE_CONSTANT_OVERFLOW (arg1
))
2531 v1
= TREE_VECTOR_CST_ELTS (arg0
);
2532 v2
= TREE_VECTOR_CST_ELTS (arg1
);
2535 if (!operand_equal_p (TREE_VALUE (v1
), TREE_VALUE (v2
),
2538 v1
= TREE_CHAIN (v1
);
2539 v2
= TREE_CHAIN (v2
);
2546 return (operand_equal_p (TREE_REALPART (arg0
), TREE_REALPART (arg1
),
2548 && operand_equal_p (TREE_IMAGPART (arg0
), TREE_IMAGPART (arg1
),
2552 return (TREE_STRING_LENGTH (arg0
) == TREE_STRING_LENGTH (arg1
)
2553 && ! memcmp (TREE_STRING_POINTER (arg0
),
2554 TREE_STRING_POINTER (arg1
),
2555 TREE_STRING_LENGTH (arg0
)));
2558 return operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0),
2564 if (flags
& OEP_ONLY_CONST
)
2567 /* Define macros to test an operand from arg0 and arg1 for equality and a
2568 variant that allows null and views null as being different from any
2569 non-null value. In the latter case, if either is null, the both
2570 must be; otherwise, do the normal comparison. */
2571 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
2572 TREE_OPERAND (arg1, N), flags)
2574 #define OP_SAME_WITH_NULL(N) \
2575 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
2576 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
2578 switch (TREE_CODE_CLASS (TREE_CODE (arg0
)))
2581 /* Two conversions are equal only if signedness and modes match. */
2582 switch (TREE_CODE (arg0
))
2587 case FIX_TRUNC_EXPR
:
2588 case FIX_FLOOR_EXPR
:
2589 case FIX_ROUND_EXPR
:
2590 if (TYPE_UNSIGNED (TREE_TYPE (arg0
))
2591 != TYPE_UNSIGNED (TREE_TYPE (arg1
)))
2601 case tcc_comparison
:
2603 if (OP_SAME (0) && OP_SAME (1))
2606 /* For commutative ops, allow the other order. */
2607 return (commutative_tree_code (TREE_CODE (arg0
))
2608 && operand_equal_p (TREE_OPERAND (arg0
, 0),
2609 TREE_OPERAND (arg1
, 1), flags
)
2610 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2611 TREE_OPERAND (arg1
, 0), flags
));
2614 /* If either of the pointer (or reference) expressions we are
2615 dereferencing contain a side effect, these cannot be equal. */
2616 if (TREE_SIDE_EFFECTS (arg0
)
2617 || TREE_SIDE_EFFECTS (arg1
))
2620 switch (TREE_CODE (arg0
))
2623 case ALIGN_INDIRECT_REF
:
2624 case MISALIGNED_INDIRECT_REF
:
2630 case ARRAY_RANGE_REF
:
2631 /* Operands 2 and 3 may be null. */
2634 && OP_SAME_WITH_NULL (2)
2635 && OP_SAME_WITH_NULL (3));
2638 /* Handle operand 2 the same as for ARRAY_REF. Operand 0
2639 may be NULL when we're called to compare MEM_EXPRs. */
2640 return OP_SAME_WITH_NULL (0)
2642 && OP_SAME_WITH_NULL (2);
2645 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
2651 case tcc_expression
:
2652 switch (TREE_CODE (arg0
))
2655 case TRUTH_NOT_EXPR
:
2658 case TRUTH_ANDIF_EXPR
:
2659 case TRUTH_ORIF_EXPR
:
2660 return OP_SAME (0) && OP_SAME (1);
2662 case TRUTH_AND_EXPR
:
2664 case TRUTH_XOR_EXPR
:
2665 if (OP_SAME (0) && OP_SAME (1))
2668 /* Otherwise take into account this is a commutative operation. */
2669 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
2670 TREE_OPERAND (arg1
, 1), flags
)
2671 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2672 TREE_OPERAND (arg1
, 0), flags
));
2675 /* If the CALL_EXPRs call different functions, then they
2676 clearly can not be equal. */
2681 unsigned int cef
= call_expr_flags (arg0
);
2682 if (flags
& OEP_PURE_SAME
)
2683 cef
&= ECF_CONST
| ECF_PURE
;
2690 /* Now see if all the arguments are the same. operand_equal_p
2691 does not handle TREE_LIST, so we walk the operands here
2692 feeding them to operand_equal_p. */
2693 arg0
= TREE_OPERAND (arg0
, 1);
2694 arg1
= TREE_OPERAND (arg1
, 1);
2695 while (arg0
&& arg1
)
2697 if (! operand_equal_p (TREE_VALUE (arg0
), TREE_VALUE (arg1
),
2701 arg0
= TREE_CHAIN (arg0
);
2702 arg1
= TREE_CHAIN (arg1
);
2705 /* If we get here and both argument lists are exhausted
2706 then the CALL_EXPRs are equal. */
2707 return ! (arg0
|| arg1
);
2713 case tcc_declaration
:
2714 /* Consider __builtin_sqrt equal to sqrt. */
2715 return (TREE_CODE (arg0
) == FUNCTION_DECL
2716 && DECL_BUILT_IN (arg0
) && DECL_BUILT_IN (arg1
)
2717 && DECL_BUILT_IN_CLASS (arg0
) == DECL_BUILT_IN_CLASS (arg1
)
2718 && DECL_FUNCTION_CODE (arg0
) == DECL_FUNCTION_CODE (arg1
));
2725 #undef OP_SAME_WITH_NULL
2728 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2729 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2731 When in doubt, return 0. */
2734 operand_equal_for_comparison_p (tree arg0
, tree arg1
, tree other
)
2736 int unsignedp1
, unsignedpo
;
2737 tree primarg0
, primarg1
, primother
;
2738 unsigned int correct_width
;
2740 if (operand_equal_p (arg0
, arg1
, 0))
2743 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
2744 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
2747 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2748 and see if the inner values are the same. This removes any
2749 signedness comparison, which doesn't matter here. */
2750 primarg0
= arg0
, primarg1
= arg1
;
2751 STRIP_NOPS (primarg0
);
2752 STRIP_NOPS (primarg1
);
2753 if (operand_equal_p (primarg0
, primarg1
, 0))
2756 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2757 actual comparison operand, ARG0.
2759 First throw away any conversions to wider types
2760 already present in the operands. */
2762 primarg1
= get_narrower (arg1
, &unsignedp1
);
2763 primother
= get_narrower (other
, &unsignedpo
);
2765 correct_width
= TYPE_PRECISION (TREE_TYPE (arg1
));
2766 if (unsignedp1
== unsignedpo
2767 && TYPE_PRECISION (TREE_TYPE (primarg1
)) < correct_width
2768 && TYPE_PRECISION (TREE_TYPE (primother
)) < correct_width
)
2770 tree type
= TREE_TYPE (arg0
);
2772 /* Make sure shorter operand is extended the right way
2773 to match the longer operand. */
2774 primarg1
= fold_convert (lang_hooks
.types
.signed_or_unsigned_type
2775 (unsignedp1
, TREE_TYPE (primarg1
)), primarg1
);
2777 if (operand_equal_p (arg0
, fold_convert (type
, primarg1
), 0))
2784 /* See if ARG is an expression that is either a comparison or is performing
2785 arithmetic on comparisons. The comparisons must only be comparing
2786 two different values, which will be stored in *CVAL1 and *CVAL2; if
2787 they are nonzero it means that some operands have already been found.
2788 No variables may be used anywhere else in the expression except in the
2789 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2790 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2792 If this is true, return 1. Otherwise, return zero. */
2795 twoval_comparison_p (tree arg
, tree
*cval1
, tree
*cval2
, int *save_p
)
2797 enum tree_code code
= TREE_CODE (arg
);
2798 enum tree_code_class
class = TREE_CODE_CLASS (code
);
2800 /* We can handle some of the tcc_expression cases here. */
2801 if (class == tcc_expression
&& code
== TRUTH_NOT_EXPR
)
2803 else if (class == tcc_expression
2804 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
2805 || code
== COMPOUND_EXPR
))
2808 else if (class == tcc_expression
&& code
== SAVE_EXPR
2809 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg
, 0)))
2811 /* If we've already found a CVAL1 or CVAL2, this expression is
2812 two complex to handle. */
2813 if (*cval1
|| *cval2
)
2823 return twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
);
2826 return (twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
)
2827 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2828 cval1
, cval2
, save_p
));
2833 case tcc_expression
:
2834 if (code
== COND_EXPR
)
2835 return (twoval_comparison_p (TREE_OPERAND (arg
, 0),
2836 cval1
, cval2
, save_p
)
2837 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2838 cval1
, cval2
, save_p
)
2839 && twoval_comparison_p (TREE_OPERAND (arg
, 2),
2840 cval1
, cval2
, save_p
));
2843 case tcc_comparison
:
2844 /* First see if we can handle the first operand, then the second. For
2845 the second operand, we know *CVAL1 can't be zero. It must be that
2846 one side of the comparison is each of the values; test for the
2847 case where this isn't true by failing if the two operands
2850 if (operand_equal_p (TREE_OPERAND (arg
, 0),
2851 TREE_OPERAND (arg
, 1), 0))
2855 *cval1
= TREE_OPERAND (arg
, 0);
2856 else if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 0), 0))
2858 else if (*cval2
== 0)
2859 *cval2
= TREE_OPERAND (arg
, 0);
2860 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 0), 0))
2865 if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 1), 0))
2867 else if (*cval2
== 0)
2868 *cval2
= TREE_OPERAND (arg
, 1);
2869 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 1), 0))
2881 /* ARG is a tree that is known to contain just arithmetic operations and
2882 comparisons. Evaluate the operations in the tree substituting NEW0 for
2883 any occurrence of OLD0 as an operand of a comparison and likewise for
2887 eval_subst (tree arg
, tree old0
, tree new0
, tree old1
, tree new1
)
2889 tree type
= TREE_TYPE (arg
);
2890 enum tree_code code
= TREE_CODE (arg
);
2891 enum tree_code_class
class = TREE_CODE_CLASS (code
);
2893 /* We can handle some of the tcc_expression cases here. */
2894 if (class == tcc_expression
&& code
== TRUTH_NOT_EXPR
)
2896 else if (class == tcc_expression
2897 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
))
2903 return fold_build1 (code
, type
,
2904 eval_subst (TREE_OPERAND (arg
, 0),
2905 old0
, new0
, old1
, new1
));
2908 return fold_build2 (code
, type
,
2909 eval_subst (TREE_OPERAND (arg
, 0),
2910 old0
, new0
, old1
, new1
),
2911 eval_subst (TREE_OPERAND (arg
, 1),
2912 old0
, new0
, old1
, new1
));
2914 case tcc_expression
:
2918 return eval_subst (TREE_OPERAND (arg
, 0), old0
, new0
, old1
, new1
);
2921 return eval_subst (TREE_OPERAND (arg
, 1), old0
, new0
, old1
, new1
);
2924 return fold_build3 (code
, type
,
2925 eval_subst (TREE_OPERAND (arg
, 0),
2926 old0
, new0
, old1
, new1
),
2927 eval_subst (TREE_OPERAND (arg
, 1),
2928 old0
, new0
, old1
, new1
),
2929 eval_subst (TREE_OPERAND (arg
, 2),
2930 old0
, new0
, old1
, new1
));
2934 /* Fall through - ??? */
2936 case tcc_comparison
:
2938 tree arg0
= TREE_OPERAND (arg
, 0);
2939 tree arg1
= TREE_OPERAND (arg
, 1);
2941 /* We need to check both for exact equality and tree equality. The
2942 former will be true if the operand has a side-effect. In that
2943 case, we know the operand occurred exactly once. */
2945 if (arg0
== old0
|| operand_equal_p (arg0
, old0
, 0))
2947 else if (arg0
== old1
|| operand_equal_p (arg0
, old1
, 0))
2950 if (arg1
== old0
|| operand_equal_p (arg1
, old0
, 0))
2952 else if (arg1
== old1
|| operand_equal_p (arg1
, old1
, 0))
2955 return fold_build2 (code
, type
, arg0
, arg1
);
2963 /* Return a tree for the case when the result of an expression is RESULT
2964 converted to TYPE and OMITTED was previously an operand of the expression
2965 but is now not needed (e.g., we folded OMITTED * 0).
2967 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2968 the conversion of RESULT to TYPE. */
2971 omit_one_operand (tree type
, tree result
, tree omitted
)
2973 tree t
= fold_convert (type
, result
);
2975 if (TREE_SIDE_EFFECTS (omitted
))
2976 return build2 (COMPOUND_EXPR
, type
, fold_ignored_result (omitted
), t
);
2978 return non_lvalue (t
);
2981 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2984 pedantic_omit_one_operand (tree type
, tree result
, tree omitted
)
2986 tree t
= fold_convert (type
, result
);
2988 if (TREE_SIDE_EFFECTS (omitted
))
2989 return build2 (COMPOUND_EXPR
, type
, fold_ignored_result (omitted
), t
);
2991 return pedantic_non_lvalue (t
);
2994 /* Return a tree for the case when the result of an expression is RESULT
2995 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
2996 of the expression but are now not needed.
2998 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
2999 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
3000 evaluated before OMITTED2. Otherwise, if neither has side effects,
3001 just do the conversion of RESULT to TYPE. */
3004 omit_two_operands (tree type
, tree result
, tree omitted1
, tree omitted2
)
3006 tree t
= fold_convert (type
, result
);
3008 if (TREE_SIDE_EFFECTS (omitted2
))
3009 t
= build2 (COMPOUND_EXPR
, type
, omitted2
, t
);
3010 if (TREE_SIDE_EFFECTS (omitted1
))
3011 t
= build2 (COMPOUND_EXPR
, type
, omitted1
, t
);
3013 return TREE_CODE (t
) != COMPOUND_EXPR
? non_lvalue (t
) : t
;
3017 /* Return a simplified tree node for the truth-negation of ARG. This
3018 never alters ARG itself. We assume that ARG is an operation that
3019 returns a truth value (0 or 1).
3021 FIXME: one would think we would fold the result, but it causes
3022 problems with the dominator optimizer. */
3024 invert_truthvalue (tree arg
)
3026 tree type
= TREE_TYPE (arg
);
3027 enum tree_code code
= TREE_CODE (arg
);
3029 if (code
== ERROR_MARK
)
3032 /* If this is a comparison, we can simply invert it, except for
3033 floating-point non-equality comparisons, in which case we just
3034 enclose a TRUTH_NOT_EXPR around what we have. */
3036 if (TREE_CODE_CLASS (code
) == tcc_comparison
)
3038 tree op_type
= TREE_TYPE (TREE_OPERAND (arg
, 0));
3039 if (FLOAT_TYPE_P (op_type
)
3040 && flag_trapping_math
3041 && code
!= ORDERED_EXPR
&& code
!= UNORDERED_EXPR
3042 && code
!= NE_EXPR
&& code
!= EQ_EXPR
)
3043 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
3046 code
= invert_tree_comparison (code
,
3047 HONOR_NANS (TYPE_MODE (op_type
)));
3048 if (code
== ERROR_MARK
)
3049 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
3051 return build2 (code
, type
,
3052 TREE_OPERAND (arg
, 0), TREE_OPERAND (arg
, 1));
3059 return constant_boolean_node (integer_zerop (arg
), type
);
3061 case TRUTH_AND_EXPR
:
3062 return build2 (TRUTH_OR_EXPR
, type
,
3063 invert_truthvalue (TREE_OPERAND (arg
, 0)),
3064 invert_truthvalue (TREE_OPERAND (arg
, 1)));
3067 return build2 (TRUTH_AND_EXPR
, type
,
3068 invert_truthvalue (TREE_OPERAND (arg
, 0)),
3069 invert_truthvalue (TREE_OPERAND (arg
, 1)));
3071 case TRUTH_XOR_EXPR
:
3072 /* Here we can invert either operand. We invert the first operand
3073 unless the second operand is a TRUTH_NOT_EXPR in which case our
3074 result is the XOR of the first operand with the inside of the
3075 negation of the second operand. */
3077 if (TREE_CODE (TREE_OPERAND (arg
, 1)) == TRUTH_NOT_EXPR
)
3078 return build2 (TRUTH_XOR_EXPR
, type
, TREE_OPERAND (arg
, 0),
3079 TREE_OPERAND (TREE_OPERAND (arg
, 1), 0));
3081 return build2 (TRUTH_XOR_EXPR
, type
,
3082 invert_truthvalue (TREE_OPERAND (arg
, 0)),
3083 TREE_OPERAND (arg
, 1));
3085 case TRUTH_ANDIF_EXPR
:
3086 return build2 (TRUTH_ORIF_EXPR
, type
,
3087 invert_truthvalue (TREE_OPERAND (arg
, 0)),
3088 invert_truthvalue (TREE_OPERAND (arg
, 1)));
3090 case TRUTH_ORIF_EXPR
:
3091 return build2 (TRUTH_ANDIF_EXPR
, type
,
3092 invert_truthvalue (TREE_OPERAND (arg
, 0)),
3093 invert_truthvalue (TREE_OPERAND (arg
, 1)));
3095 case TRUTH_NOT_EXPR
:
3096 return TREE_OPERAND (arg
, 0);
3100 tree arg1
= TREE_OPERAND (arg
, 1);
3101 tree arg2
= TREE_OPERAND (arg
, 2);
3102 /* A COND_EXPR may have a throw as one operand, which
3103 then has void type. Just leave void operands
3105 return build3 (COND_EXPR
, type
, TREE_OPERAND (arg
, 0),
3106 VOID_TYPE_P (TREE_TYPE (arg1
))
3107 ? arg1
: invert_truthvalue (arg1
),
3108 VOID_TYPE_P (TREE_TYPE (arg2
))
3109 ? arg2
: invert_truthvalue (arg2
));
3113 return build2 (COMPOUND_EXPR
, type
, TREE_OPERAND (arg
, 0),
3114 invert_truthvalue (TREE_OPERAND (arg
, 1)));
3116 case NON_LVALUE_EXPR
:
3117 return invert_truthvalue (TREE_OPERAND (arg
, 0));
3120 if (TREE_CODE (TREE_TYPE (arg
)) == BOOLEAN_TYPE
)
3125 return build1 (TREE_CODE (arg
), type
,
3126 invert_truthvalue (TREE_OPERAND (arg
, 0)));
3129 if (!integer_onep (TREE_OPERAND (arg
, 1)))
3131 return build2 (EQ_EXPR
, type
, arg
,
3132 build_int_cst (type
, 0));
3135 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
3137 case CLEANUP_POINT_EXPR
:
3138 return build1 (CLEANUP_POINT_EXPR
, type
,
3139 invert_truthvalue (TREE_OPERAND (arg
, 0)));
3144 gcc_assert (TREE_CODE (TREE_TYPE (arg
)) == BOOLEAN_TYPE
);
3145 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
3148 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3149 operands are another bit-wise operation with a common input. If so,
3150 distribute the bit operations to save an operation and possibly two if
3151 constants are involved. For example, convert
3152 (A | B) & (A | C) into A | (B & C)
3153 Further simplification will occur if B and C are constants.
3155 If this optimization cannot be done, 0 will be returned. */
3158 distribute_bit_expr (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
3163 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
3164 || TREE_CODE (arg0
) == code
3165 || (TREE_CODE (arg0
) != BIT_AND_EXPR
3166 && TREE_CODE (arg0
) != BIT_IOR_EXPR
))
3169 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0))
3171 common
= TREE_OPERAND (arg0
, 0);
3172 left
= TREE_OPERAND (arg0
, 1);
3173 right
= TREE_OPERAND (arg1
, 1);
3175 else if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 1), 0))
3177 common
= TREE_OPERAND (arg0
, 0);
3178 left
= TREE_OPERAND (arg0
, 1);
3179 right
= TREE_OPERAND (arg1
, 0);
3181 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 0), 0))
3183 common
= TREE_OPERAND (arg0
, 1);
3184 left
= TREE_OPERAND (arg0
, 0);
3185 right
= TREE_OPERAND (arg1
, 1);
3187 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1), 0))
3189 common
= TREE_OPERAND (arg0
, 1);
3190 left
= TREE_OPERAND (arg0
, 0);
3191 right
= TREE_OPERAND (arg1
, 0);
3196 return fold_build2 (TREE_CODE (arg0
), type
, common
,
3197 fold_build2 (code
, type
, left
, right
));
3200 /* Knowing that ARG0 and ARG1 are both RDIV_EXPRs, simplify a binary operation
3201 with code CODE. This optimization is unsafe. */
3203 distribute_real_division (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
3205 bool mul0
= TREE_CODE (arg0
) == MULT_EXPR
;
3206 bool mul1
= TREE_CODE (arg1
) == MULT_EXPR
;
3208 /* (A / C) +- (B / C) -> (A +- B) / C. */
3210 && operand_equal_p (TREE_OPERAND (arg0
, 1),
3211 TREE_OPERAND (arg1
, 1), 0))
3212 return fold_build2 (mul0
? MULT_EXPR
: RDIV_EXPR
, type
,
3213 fold_build2 (code
, type
,
3214 TREE_OPERAND (arg0
, 0),
3215 TREE_OPERAND (arg1
, 0)),
3216 TREE_OPERAND (arg0
, 1));
3218 /* (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2). */
3219 if (operand_equal_p (TREE_OPERAND (arg0
, 0),
3220 TREE_OPERAND (arg1
, 0), 0)
3221 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == REAL_CST
3222 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == REAL_CST
)
3224 REAL_VALUE_TYPE r0
, r1
;
3225 r0
= TREE_REAL_CST (TREE_OPERAND (arg0
, 1));
3226 r1
= TREE_REAL_CST (TREE_OPERAND (arg1
, 1));
3228 real_arithmetic (&r0
, RDIV_EXPR
, &dconst1
, &r0
);
3230 real_arithmetic (&r1
, RDIV_EXPR
, &dconst1
, &r1
);
3231 real_arithmetic (&r0
, code
, &r0
, &r1
);
3232 return fold_build2 (MULT_EXPR
, type
,
3233 TREE_OPERAND (arg0
, 0),
3234 build_real (type
, r0
));
3240 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3241 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3244 make_bit_field_ref (tree inner
, tree type
, int bitsize
, int bitpos
,
3251 tree size
= TYPE_SIZE (TREE_TYPE (inner
));
3252 if ((INTEGRAL_TYPE_P (TREE_TYPE (inner
))
3253 || POINTER_TYPE_P (TREE_TYPE (inner
)))
3254 && host_integerp (size
, 0)
3255 && tree_low_cst (size
, 0) == bitsize
)
3256 return fold_convert (type
, inner
);
3259 result
= build3 (BIT_FIELD_REF
, type
, inner
,
3260 size_int (bitsize
), bitsize_int (bitpos
));
3262 BIT_FIELD_REF_UNSIGNED (result
) = unsignedp
;
3267 /* Optimize a bit-field compare.
3269 There are two cases: First is a compare against a constant and the
3270 second is a comparison of two items where the fields are at the same
3271 bit position relative to the start of a chunk (byte, halfword, word)
3272 large enough to contain it. In these cases we can avoid the shift
3273 implicit in bitfield extractions.
3275 For constants, we emit a compare of the shifted constant with the
3276 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3277 compared. For two fields at the same position, we do the ANDs with the
3278 similar mask and compare the result of the ANDs.
3280 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3281 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3282 are the left and right operands of the comparison, respectively.
3284 If the optimization described above can be done, we return the resulting
3285 tree. Otherwise we return zero. */
3288 optimize_bit_field_compare (enum tree_code code
, tree compare_type
,
3291 HOST_WIDE_INT lbitpos
, lbitsize
, rbitpos
, rbitsize
, nbitpos
, nbitsize
;
3292 tree type
= TREE_TYPE (lhs
);
3293 tree signed_type
, unsigned_type
;
3294 int const_p
= TREE_CODE (rhs
) == INTEGER_CST
;
3295 enum machine_mode lmode
, rmode
, nmode
;
3296 int lunsignedp
, runsignedp
;
3297 int lvolatilep
= 0, rvolatilep
= 0;
3298 tree linner
, rinner
= NULL_TREE
;
3302 /* Get all the information about the extractions being done. If the bit size
3303 if the same as the size of the underlying object, we aren't doing an
3304 extraction at all and so can do nothing. We also don't want to
3305 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3306 then will no longer be able to replace it. */
3307 linner
= get_inner_reference (lhs
, &lbitsize
, &lbitpos
, &offset
, &lmode
,
3308 &lunsignedp
, &lvolatilep
, false);
3309 if (linner
== lhs
|| lbitsize
== GET_MODE_BITSIZE (lmode
) || lbitsize
< 0
3310 || offset
!= 0 || TREE_CODE (linner
) == PLACEHOLDER_EXPR
)
3315 /* If this is not a constant, we can only do something if bit positions,
3316 sizes, and signedness are the same. */
3317 rinner
= get_inner_reference (rhs
, &rbitsize
, &rbitpos
, &offset
, &rmode
,
3318 &runsignedp
, &rvolatilep
, false);
3320 if (rinner
== rhs
|| lbitpos
!= rbitpos
|| lbitsize
!= rbitsize
3321 || lunsignedp
!= runsignedp
|| offset
!= 0
3322 || TREE_CODE (rinner
) == PLACEHOLDER_EXPR
)
3326 /* See if we can find a mode to refer to this field. We should be able to,
3327 but fail if we can't. */
3328 nmode
= get_best_mode (lbitsize
, lbitpos
,
3329 const_p
? TYPE_ALIGN (TREE_TYPE (linner
))
3330 : MIN (TYPE_ALIGN (TREE_TYPE (linner
)),
3331 TYPE_ALIGN (TREE_TYPE (rinner
))),
3332 word_mode
, lvolatilep
|| rvolatilep
);
3333 if (nmode
== VOIDmode
)
3336 /* Set signed and unsigned types of the precision of this mode for the
3338 signed_type
= lang_hooks
.types
.type_for_mode (nmode
, 0);
3339 unsigned_type
= lang_hooks
.types
.type_for_mode (nmode
, 1);
3341 /* Compute the bit position and size for the new reference and our offset
3342 within it. If the new reference is the same size as the original, we
3343 won't optimize anything, so return zero. */
3344 nbitsize
= GET_MODE_BITSIZE (nmode
);
3345 nbitpos
= lbitpos
& ~ (nbitsize
- 1);
3347 if (nbitsize
== lbitsize
)
3350 if (BYTES_BIG_ENDIAN
)
3351 lbitpos
= nbitsize
- lbitsize
- lbitpos
;
3353 /* Make the mask to be used against the extracted field. */
3354 mask
= build_int_cst (unsigned_type
, -1);
3355 mask
= force_fit_type (mask
, 0, false, false);
3356 mask
= fold_convert (unsigned_type
, mask
);
3357 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (nbitsize
- lbitsize
), 0);
3358 mask
= const_binop (RSHIFT_EXPR
, mask
,
3359 size_int (nbitsize
- lbitsize
- lbitpos
), 0);
3362 /* If not comparing with constant, just rework the comparison
3364 return build2 (code
, compare_type
,
3365 build2 (BIT_AND_EXPR
, unsigned_type
,
3366 make_bit_field_ref (linner
, unsigned_type
,
3367 nbitsize
, nbitpos
, 1),
3369 build2 (BIT_AND_EXPR
, unsigned_type
,
3370 make_bit_field_ref (rinner
, unsigned_type
,
3371 nbitsize
, nbitpos
, 1),
3374 /* Otherwise, we are handling the constant case. See if the constant is too
3375 big for the field. Warn and return a tree of for 0 (false) if so. We do
3376 this not only for its own sake, but to avoid having to test for this
3377 error case below. If we didn't, we might generate wrong code.
3379 For unsigned fields, the constant shifted right by the field length should
3380 be all zero. For signed fields, the high-order bits should agree with
3385 if (! integer_zerop (const_binop (RSHIFT_EXPR
,
3386 fold_convert (unsigned_type
, rhs
),
3387 size_int (lbitsize
), 0)))
3389 warning (0, "comparison is always %d due to width of bit-field",
3391 return constant_boolean_node (code
== NE_EXPR
, compare_type
);
3396 tree tem
= const_binop (RSHIFT_EXPR
, fold_convert (signed_type
, rhs
),
3397 size_int (lbitsize
- 1), 0);
3398 if (! integer_zerop (tem
) && ! integer_all_onesp (tem
))
3400 warning (0, "comparison is always %d due to width of bit-field",
3402 return constant_boolean_node (code
== NE_EXPR
, compare_type
);
3406 /* Single-bit compares should always be against zero. */
3407 if (lbitsize
== 1 && ! integer_zerop (rhs
))
3409 code
= code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
;
3410 rhs
= build_int_cst (type
, 0);
3413 /* Make a new bitfield reference, shift the constant over the
3414 appropriate number of bits and mask it with the computed mask
3415 (in case this was a signed field). If we changed it, make a new one. */
3416 lhs
= make_bit_field_ref (linner
, unsigned_type
, nbitsize
, nbitpos
, 1);
3419 TREE_SIDE_EFFECTS (lhs
) = 1;
3420 TREE_THIS_VOLATILE (lhs
) = 1;
3423 rhs
= const_binop (BIT_AND_EXPR
,
3424 const_binop (LSHIFT_EXPR
,
3425 fold_convert (unsigned_type
, rhs
),
3426 size_int (lbitpos
), 0),
3429 return build2 (code
, compare_type
,
3430 build2 (BIT_AND_EXPR
, unsigned_type
, lhs
, mask
),
3434 /* Subroutine for fold_truthop: decode a field reference.
3436 If EXP is a comparison reference, we return the innermost reference.
3438 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3439 set to the starting bit number.
3441 If the innermost field can be completely contained in a mode-sized
3442 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3444 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3445 otherwise it is not changed.
3447 *PUNSIGNEDP is set to the signedness of the field.
3449 *PMASK is set to the mask used. This is either contained in a
3450 BIT_AND_EXPR or derived from the width of the field.
3452 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3454 Return 0 if this is not a component reference or is one that we can't
3455 do anything with. */
3458 decode_field_reference (tree exp
, HOST_WIDE_INT
*pbitsize
,
3459 HOST_WIDE_INT
*pbitpos
, enum machine_mode
*pmode
,
3460 int *punsignedp
, int *pvolatilep
,
3461 tree
*pmask
, tree
*pand_mask
)
3463 tree outer_type
= 0;
3465 tree mask
, inner
, offset
;
3467 unsigned int precision
;
3469 /* All the optimizations using this function assume integer fields.
3470 There are problems with FP fields since the type_for_size call
3471 below can fail for, e.g., XFmode. */
3472 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp
)))
3475 /* We are interested in the bare arrangement of bits, so strip everything
3476 that doesn't affect the machine mode. However, record the type of the
3477 outermost expression if it may matter below. */
3478 if (TREE_CODE (exp
) == NOP_EXPR
3479 || TREE_CODE (exp
) == CONVERT_EXPR
3480 || TREE_CODE (exp
) == NON_LVALUE_EXPR
)
3481 outer_type
= TREE_TYPE (exp
);
3484 if (TREE_CODE (exp
) == BIT_AND_EXPR
)
3486 and_mask
= TREE_OPERAND (exp
, 1);
3487 exp
= TREE_OPERAND (exp
, 0);
3488 STRIP_NOPS (exp
); STRIP_NOPS (and_mask
);
3489 if (TREE_CODE (and_mask
) != INTEGER_CST
)
3493 inner
= get_inner_reference (exp
, pbitsize
, pbitpos
, &offset
, pmode
,
3494 punsignedp
, pvolatilep
, false);
3495 if ((inner
== exp
&& and_mask
== 0)
3496 || *pbitsize
< 0 || offset
!= 0
3497 || TREE_CODE (inner
) == PLACEHOLDER_EXPR
)
3500 /* If the number of bits in the reference is the same as the bitsize of
3501 the outer type, then the outer type gives the signedness. Otherwise
3502 (in case of a small bitfield) the signedness is unchanged. */
3503 if (outer_type
&& *pbitsize
== TYPE_PRECISION (outer_type
))
3504 *punsignedp
= TYPE_UNSIGNED (outer_type
);
3506 /* Compute the mask to access the bitfield. */
3507 unsigned_type
= lang_hooks
.types
.type_for_size (*pbitsize
, 1);
3508 precision
= TYPE_PRECISION (unsigned_type
);
3510 mask
= build_int_cst (unsigned_type
, -1);
3511 mask
= force_fit_type (mask
, 0, false, false);
3513 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
3514 mask
= const_binop (RSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
3516 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3518 mask
= fold_build2 (BIT_AND_EXPR
, unsigned_type
,
3519 fold_convert (unsigned_type
, and_mask
), mask
);
3522 *pand_mask
= and_mask
;
3526 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3530 all_ones_mask_p (tree mask
, int size
)
3532 tree type
= TREE_TYPE (mask
);
3533 unsigned int precision
= TYPE_PRECISION (type
);
3536 tmask
= build_int_cst (lang_hooks
.types
.signed_type (type
), -1);
3537 tmask
= force_fit_type (tmask
, 0, false, false);
3540 tree_int_cst_equal (mask
,
3541 const_binop (RSHIFT_EXPR
,
3542 const_binop (LSHIFT_EXPR
, tmask
,
3543 size_int (precision
- size
),
3545 size_int (precision
- size
), 0));
3548 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3549 represents the sign bit of EXP's type. If EXP represents a sign
3550 or zero extension, also test VAL against the unextended type.
3551 The return value is the (sub)expression whose sign bit is VAL,
3552 or NULL_TREE otherwise. */
3555 sign_bit_p (tree exp
, tree val
)
3557 unsigned HOST_WIDE_INT mask_lo
, lo
;
3558 HOST_WIDE_INT mask_hi
, hi
;
3562 /* Tree EXP must have an integral type. */
3563 t
= TREE_TYPE (exp
);
3564 if (! INTEGRAL_TYPE_P (t
))
3567 /* Tree VAL must be an integer constant. */
3568 if (TREE_CODE (val
) != INTEGER_CST
3569 || TREE_CONSTANT_OVERFLOW (val
))
3572 width
= TYPE_PRECISION (t
);
3573 if (width
> HOST_BITS_PER_WIDE_INT
)
3575 hi
= (unsigned HOST_WIDE_INT
) 1 << (width
- HOST_BITS_PER_WIDE_INT
- 1);
3578 mask_hi
= ((unsigned HOST_WIDE_INT
) -1
3579 >> (2 * HOST_BITS_PER_WIDE_INT
- width
));
3585 lo
= (unsigned HOST_WIDE_INT
) 1 << (width
- 1);
3588 mask_lo
= ((unsigned HOST_WIDE_INT
) -1
3589 >> (HOST_BITS_PER_WIDE_INT
- width
));
3592 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3593 treat VAL as if it were unsigned. */
3594 if ((TREE_INT_CST_HIGH (val
) & mask_hi
) == hi
3595 && (TREE_INT_CST_LOW (val
) & mask_lo
) == lo
)
3598 /* Handle extension from a narrower type. */
3599 if (TREE_CODE (exp
) == NOP_EXPR
3600 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp
, 0))) < width
)
3601 return sign_bit_p (TREE_OPERAND (exp
, 0), val
);
3606 /* Subroutine for fold_truthop: determine if an operand is simple enough
3607 to be evaluated unconditionally. */
3610 simple_operand_p (tree exp
)
3612 /* Strip any conversions that don't change the machine mode. */
3615 return (CONSTANT_CLASS_P (exp
)
3616 || TREE_CODE (exp
) == SSA_NAME
3618 && ! TREE_ADDRESSABLE (exp
)
3619 && ! TREE_THIS_VOLATILE (exp
)
3620 && ! DECL_NONLOCAL (exp
)
3621 /* Don't regard global variables as simple. They may be
3622 allocated in ways unknown to the compiler (shared memory,
3623 #pragma weak, etc). */
3624 && ! TREE_PUBLIC (exp
)
3625 && ! DECL_EXTERNAL (exp
)
3626 /* Loading a static variable is unduly expensive, but global
3627 registers aren't expensive. */
3628 && (! TREE_STATIC (exp
) || DECL_REGISTER (exp
))));
3631 /* The following functions are subroutines to fold_range_test and allow it to
3632 try to change a logical combination of comparisons into a range test.
3635 X == 2 || X == 3 || X == 4 || X == 5
3639 (unsigned) (X - 2) <= 3
3641 We describe each set of comparisons as being either inside or outside
3642 a range, using a variable named like IN_P, and then describe the
3643 range with a lower and upper bound. If one of the bounds is omitted,
3644 it represents either the highest or lowest value of the type.
3646 In the comments below, we represent a range by two numbers in brackets
3647 preceded by a "+" to designate being inside that range, or a "-" to
3648 designate being outside that range, so the condition can be inverted by
3649 flipping the prefix. An omitted bound is represented by a "-". For
3650 example, "- [-, 10]" means being outside the range starting at the lowest
3651 possible value and ending at 10, in other words, being greater than 10.
3652 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3655 We set up things so that the missing bounds are handled in a consistent
3656 manner so neither a missing bound nor "true" and "false" need to be
3657 handled using a special case. */
3659 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3660 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3661 and UPPER1_P are nonzero if the respective argument is an upper bound
3662 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3663 must be specified for a comparison. ARG1 will be converted to ARG0's
3664 type if both are specified. */
3667 range_binop (enum tree_code code
, tree type
, tree arg0
, int upper0_p
,
3668 tree arg1
, int upper1_p
)
3674 /* If neither arg represents infinity, do the normal operation.
3675 Else, if not a comparison, return infinity. Else handle the special
3676 comparison rules. Note that most of the cases below won't occur, but
3677 are handled for consistency. */
3679 if (arg0
!= 0 && arg1
!= 0)
3681 tem
= fold_build2 (code
, type
!= 0 ? type
: TREE_TYPE (arg0
),
3682 arg0
, fold_convert (TREE_TYPE (arg0
), arg1
));
3684 return TREE_CODE (tem
) == INTEGER_CST
? tem
: 0;
3687 if (TREE_CODE_CLASS (code
) != tcc_comparison
)
3690 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3691 for neither. In real maths, we cannot assume open ended ranges are
3692 the same. But, this is computer arithmetic, where numbers are finite.
3693 We can therefore make the transformation of any unbounded range with
3694 the value Z, Z being greater than any representable number. This permits
3695 us to treat unbounded ranges as equal. */
3696 sgn0
= arg0
!= 0 ? 0 : (upper0_p
? 1 : -1);
3697 sgn1
= arg1
!= 0 ? 0 : (upper1_p
? 1 : -1);
3701 result
= sgn0
== sgn1
;
3704 result
= sgn0
!= sgn1
;
3707 result
= sgn0
< sgn1
;
3710 result
= sgn0
<= sgn1
;
3713 result
= sgn0
> sgn1
;
3716 result
= sgn0
>= sgn1
;
3722 return constant_boolean_node (result
, type
);
3725 /* Given EXP, a logical expression, set the range it is testing into
3726 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3727 actually being tested. *PLOW and *PHIGH will be made of the same type
3728 as the returned expression. If EXP is not a comparison, we will most
3729 likely not be returning a useful value and range. */
3732 make_range (tree exp
, int *pin_p
, tree
*plow
, tree
*phigh
)
3734 enum tree_code code
;
3735 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
;
3736 tree exp_type
= NULL_TREE
, arg0_type
= NULL_TREE
;
3738 tree low
, high
, n_low
, n_high
;
3740 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3741 and see if we can refine the range. Some of the cases below may not
3742 happen, but it doesn't seem worth worrying about this. We "continue"
3743 the outer loop when we've changed something; otherwise we "break"
3744 the switch, which will "break" the while. */
3747 low
= high
= build_int_cst (TREE_TYPE (exp
), 0);
3751 code
= TREE_CODE (exp
);
3752 exp_type
= TREE_TYPE (exp
);
3754 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code
)))
3756 if (TREE_CODE_LENGTH (code
) > 0)
3757 arg0
= TREE_OPERAND (exp
, 0);
3758 if (TREE_CODE_CLASS (code
) == tcc_comparison
3759 || TREE_CODE_CLASS (code
) == tcc_unary
3760 || TREE_CODE_CLASS (code
) == tcc_binary
)
3761 arg0_type
= TREE_TYPE (arg0
);
3762 if (TREE_CODE_CLASS (code
) == tcc_binary
3763 || TREE_CODE_CLASS (code
) == tcc_comparison
3764 || (TREE_CODE_CLASS (code
) == tcc_expression
3765 && TREE_CODE_LENGTH (code
) > 1))
3766 arg1
= TREE_OPERAND (exp
, 1);
3771 case TRUTH_NOT_EXPR
:
3772 in_p
= ! in_p
, exp
= arg0
;
3775 case EQ_EXPR
: case NE_EXPR
:
3776 case LT_EXPR
: case LE_EXPR
: case GE_EXPR
: case GT_EXPR
:
3777 /* We can only do something if the range is testing for zero
3778 and if the second operand is an integer constant. Note that
3779 saying something is "in" the range we make is done by
3780 complementing IN_P since it will set in the initial case of
3781 being not equal to zero; "out" is leaving it alone. */
3782 if (low
== 0 || high
== 0
3783 || ! integer_zerop (low
) || ! integer_zerop (high
)
3784 || TREE_CODE (arg1
) != INTEGER_CST
)
3789 case NE_EXPR
: /* - [c, c] */
3792 case EQ_EXPR
: /* + [c, c] */
3793 in_p
= ! in_p
, low
= high
= arg1
;
3795 case GT_EXPR
: /* - [-, c] */
3796 low
= 0, high
= arg1
;
3798 case GE_EXPR
: /* + [c, -] */
3799 in_p
= ! in_p
, low
= arg1
, high
= 0;
3801 case LT_EXPR
: /* - [c, -] */
3802 low
= arg1
, high
= 0;
3804 case LE_EXPR
: /* + [-, c] */
3805 in_p
= ! in_p
, low
= 0, high
= arg1
;
3811 /* If this is an unsigned comparison, we also know that EXP is
3812 greater than or equal to zero. We base the range tests we make
3813 on that fact, so we record it here so we can parse existing
3814 range tests. We test arg0_type since often the return type
3815 of, e.g. EQ_EXPR, is boolean. */
3816 if (TYPE_UNSIGNED (arg0_type
) && (low
== 0 || high
== 0))
3818 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3820 build_int_cst (arg0_type
, 0),
3824 in_p
= n_in_p
, low
= n_low
, high
= n_high
;
3826 /* If the high bound is missing, but we have a nonzero low
3827 bound, reverse the range so it goes from zero to the low bound
3829 if (high
== 0 && low
&& ! integer_zerop (low
))
3832 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low
, 0,
3833 integer_one_node
, 0);
3834 low
= build_int_cst (arg0_type
, 0);
3842 /* (-x) IN [a,b] -> x in [-b, -a] */
3843 n_low
= range_binop (MINUS_EXPR
, exp_type
,
3844 build_int_cst (exp_type
, 0),
3846 n_high
= range_binop (MINUS_EXPR
, exp_type
,
3847 build_int_cst (exp_type
, 0),
3849 low
= n_low
, high
= n_high
;
3855 exp
= build2 (MINUS_EXPR
, exp_type
, negate_expr (arg0
),
3856 build_int_cst (exp_type
, 1));
3859 case PLUS_EXPR
: case MINUS_EXPR
:
3860 if (TREE_CODE (arg1
) != INTEGER_CST
)
3863 /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
3864 move a constant to the other side. */
3865 if (flag_wrapv
&& !TYPE_UNSIGNED (arg0_type
))
3868 /* If EXP is signed, any overflow in the computation is undefined,
3869 so we don't worry about it so long as our computations on
3870 the bounds don't overflow. For unsigned, overflow is defined
3871 and this is exactly the right thing. */
3872 n_low
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3873 arg0_type
, low
, 0, arg1
, 0);
3874 n_high
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3875 arg0_type
, high
, 1, arg1
, 0);
3876 if ((n_low
!= 0 && TREE_OVERFLOW (n_low
))
3877 || (n_high
!= 0 && TREE_OVERFLOW (n_high
)))
3880 /* Check for an unsigned range which has wrapped around the maximum
3881 value thus making n_high < n_low, and normalize it. */
3882 if (n_low
&& n_high
&& tree_int_cst_lt (n_high
, n_low
))
3884 low
= range_binop (PLUS_EXPR
, arg0_type
, n_high
, 0,
3885 integer_one_node
, 0);
3886 high
= range_binop (MINUS_EXPR
, arg0_type
, n_low
, 0,
3887 integer_one_node
, 0);
3889 /* If the range is of the form +/- [ x+1, x ], we won't
3890 be able to normalize it. But then, it represents the
3891 whole range or the empty set, so make it
3893 if (tree_int_cst_equal (n_low
, low
)
3894 && tree_int_cst_equal (n_high
, high
))
3900 low
= n_low
, high
= n_high
;
3905 case NOP_EXPR
: case NON_LVALUE_EXPR
: case CONVERT_EXPR
:
3906 if (TYPE_PRECISION (arg0_type
) > TYPE_PRECISION (exp_type
))
3909 if (! INTEGRAL_TYPE_P (arg0_type
)
3910 || (low
!= 0 && ! int_fits_type_p (low
, arg0_type
))
3911 || (high
!= 0 && ! int_fits_type_p (high
, arg0_type
)))
3914 n_low
= low
, n_high
= high
;
3917 n_low
= fold_convert (arg0_type
, n_low
);
3920 n_high
= fold_convert (arg0_type
, n_high
);
3923 /* If we're converting arg0 from an unsigned type, to exp,
3924 a signed type, we will be doing the comparison as unsigned.
3925 The tests above have already verified that LOW and HIGH
3928 So we have to ensure that we will handle large unsigned
3929 values the same way that the current signed bounds treat
3932 if (!TYPE_UNSIGNED (exp_type
) && TYPE_UNSIGNED (arg0_type
))
3935 tree equiv_type
= lang_hooks
.types
.type_for_mode
3936 (TYPE_MODE (arg0_type
), 1);
3938 /* A range without an upper bound is, naturally, unbounded.
3939 Since convert would have cropped a very large value, use
3940 the max value for the destination type. */
3942 = TYPE_MAX_VALUE (equiv_type
) ? TYPE_MAX_VALUE (equiv_type
)
3943 : TYPE_MAX_VALUE (arg0_type
);
3945 if (TYPE_PRECISION (exp_type
) == TYPE_PRECISION (arg0_type
))
3946 high_positive
= fold_build2 (RSHIFT_EXPR
, arg0_type
,
3947 fold_convert (arg0_type
,
3949 fold_convert (arg0_type
,
3952 /* If the low bound is specified, "and" the range with the
3953 range for which the original unsigned value will be
3957 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3958 1, n_low
, n_high
, 1,
3959 fold_convert (arg0_type
,
3964 in_p
= (n_in_p
== in_p
);
3968 /* Otherwise, "or" the range with the range of the input
3969 that will be interpreted as negative. */
3970 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3971 0, n_low
, n_high
, 1,
3972 fold_convert (arg0_type
,
3977 in_p
= (in_p
!= n_in_p
);
3982 low
= n_low
, high
= n_high
;
3992 /* If EXP is a constant, we can evaluate whether this is true or false. */
3993 if (TREE_CODE (exp
) == INTEGER_CST
)
3995 in_p
= in_p
== (integer_onep (range_binop (GE_EXPR
, integer_type_node
,
3997 && integer_onep (range_binop (LE_EXPR
, integer_type_node
,
4003 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
4007 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
4008 type, TYPE, return an expression to test if EXP is in (or out of, depending
4009 on IN_P) the range. Return 0 if the test couldn't be created. */
4012 build_range_check (tree type
, tree exp
, int in_p
, tree low
, tree high
)
4014 tree etype
= TREE_TYPE (exp
);
4017 #ifdef HAVE_canonicalize_funcptr_for_compare
4018 /* Disable this optimization for function pointer expressions
4019 on targets that require function pointer canonicalization. */
4020 if (HAVE_canonicalize_funcptr_for_compare
4021 && TREE_CODE (etype
) == POINTER_TYPE
4022 && TREE_CODE (TREE_TYPE (etype
)) == FUNCTION_TYPE
)
4028 value
= build_range_check (type
, exp
, 1, low
, high
);
4030 return invert_truthvalue (value
);
4035 if (low
== 0 && high
== 0)
4036 return build_int_cst (type
, 1);
4039 return fold_build2 (LE_EXPR
, type
, exp
,
4040 fold_convert (etype
, high
));
4043 return fold_build2 (GE_EXPR
, type
, exp
,
4044 fold_convert (etype
, low
));
4046 if (operand_equal_p (low
, high
, 0))
4047 return fold_build2 (EQ_EXPR
, type
, exp
,
4048 fold_convert (etype
, low
));
4050 if (integer_zerop (low
))
4052 if (! TYPE_UNSIGNED (etype
))
4054 etype
= lang_hooks
.types
.unsigned_type (etype
);
4055 high
= fold_convert (etype
, high
);
4056 exp
= fold_convert (etype
, exp
);
4058 return build_range_check (type
, exp
, 1, 0, high
);
4061 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
4062 if (integer_onep (low
) && TREE_CODE (high
) == INTEGER_CST
)
4064 unsigned HOST_WIDE_INT lo
;
4068 prec
= TYPE_PRECISION (etype
);
4069 if (prec
<= HOST_BITS_PER_WIDE_INT
)
4072 lo
= ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1)) - 1;
4076 hi
= ((HOST_WIDE_INT
) 1 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)) - 1;
4077 lo
= (unsigned HOST_WIDE_INT
) -1;
4080 if (TREE_INT_CST_HIGH (high
) == hi
&& TREE_INT_CST_LOW (high
) == lo
)
4082 if (TYPE_UNSIGNED (etype
))
4084 etype
= lang_hooks
.types
.signed_type (etype
);
4085 exp
= fold_convert (etype
, exp
);
4087 return fold_build2 (GT_EXPR
, type
, exp
,
4088 build_int_cst (etype
, 0));
4092 value
= const_binop (MINUS_EXPR
, high
, low
, 0);
4093 if (value
!= 0 && (!flag_wrapv
|| TREE_OVERFLOW (value
))
4094 && ! TYPE_UNSIGNED (etype
))
4096 tree utype
, minv
, maxv
;
4098 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
4099 for the type in question, as we rely on this here. */
4100 switch (TREE_CODE (etype
))
4105 /* There is no requirement that LOW be within the range of ETYPE
4106 if the latter is a subtype. It must, however, be within the base
4107 type of ETYPE. So be sure we do the subtraction in that type. */
4108 if (TREE_TYPE (etype
))
4109 etype
= TREE_TYPE (etype
);
4110 utype
= lang_hooks
.types
.unsigned_type (etype
);
4111 maxv
= fold_convert (utype
, TYPE_MAX_VALUE (etype
));
4112 maxv
= range_binop (PLUS_EXPR
, NULL_TREE
, maxv
, 1,
4113 integer_one_node
, 1);
4114 minv
= fold_convert (utype
, TYPE_MIN_VALUE (etype
));
4115 if (integer_zerop (range_binop (NE_EXPR
, integer_type_node
,
4119 high
= fold_convert (etype
, high
);
4120 low
= fold_convert (etype
, low
);
4121 exp
= fold_convert (etype
, exp
);
4122 value
= const_binop (MINUS_EXPR
, high
, low
, 0);
4130 if (value
!= 0 && ! TREE_OVERFLOW (value
))
4132 /* There is no requirement that LOW be within the range of ETYPE
4133 if the latter is a subtype. It must, however, be within the base
4134 type of ETYPE. So be sure we do the subtraction in that type. */
4135 if (INTEGRAL_TYPE_P (etype
) && TREE_TYPE (etype
))
4137 etype
= TREE_TYPE (etype
);
4138 exp
= fold_convert (etype
, exp
);
4139 low
= fold_convert (etype
, low
);
4140 value
= fold_convert (etype
, value
);
4143 return build_range_check (type
,
4144 fold_build2 (MINUS_EXPR
, etype
, exp
, low
),
4145 1, build_int_cst (etype
, 0), value
);
4151 /* Given two ranges, see if we can merge them into one. Return 1 if we
4152 can, 0 if we can't. Set the output range into the specified parameters. */
4155 merge_ranges (int *pin_p
, tree
*plow
, tree
*phigh
, int in0_p
, tree low0
,
4156 tree high0
, int in1_p
, tree low1
, tree high1
)
4164 int lowequal
= ((low0
== 0 && low1
== 0)
4165 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
4166 low0
, 0, low1
, 0)));
4167 int highequal
= ((high0
== 0 && high1
== 0)
4168 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
4169 high0
, 1, high1
, 1)));
4171 /* Make range 0 be the range that starts first, or ends last if they
4172 start at the same value. Swap them if it isn't. */
4173 if (integer_onep (range_binop (GT_EXPR
, integer_type_node
,
4176 && integer_onep (range_binop (GT_EXPR
, integer_type_node
,
4177 high1
, 1, high0
, 1))))
4179 temp
= in0_p
, in0_p
= in1_p
, in1_p
= temp
;
4180 tem
= low0
, low0
= low1
, low1
= tem
;
4181 tem
= high0
, high0
= high1
, high1
= tem
;
4184 /* Now flag two cases, whether the ranges are disjoint or whether the
4185 second range is totally subsumed in the first. Note that the tests
4186 below are simplified by the ones above. */
4187 no_overlap
= integer_onep (range_binop (LT_EXPR
, integer_type_node
,
4188 high0
, 1, low1
, 0));
4189 subset
= integer_onep (range_binop (LE_EXPR
, integer_type_node
,
4190 high1
, 1, high0
, 1));
4192 /* We now have four cases, depending on whether we are including or
4193 excluding the two ranges. */
4196 /* If they don't overlap, the result is false. If the second range
4197 is a subset it is the result. Otherwise, the range is from the start
4198 of the second to the end of the first. */
4200 in_p
= 0, low
= high
= 0;
4202 in_p
= 1, low
= low1
, high
= high1
;
4204 in_p
= 1, low
= low1
, high
= high0
;
4207 else if (in0_p
&& ! in1_p
)
4209 /* If they don't overlap, the result is the first range. If they are
4210 equal, the result is false. If the second range is a subset of the
4211 first, and the ranges begin at the same place, we go from just after
4212 the end of the first range to the end of the second. If the second
4213 range is not a subset of the first, or if it is a subset and both
4214 ranges end at the same place, the range starts at the start of the
4215 first range and ends just before the second range.
4216 Otherwise, we can't describe this as a single range. */
4218 in_p
= 1, low
= low0
, high
= high0
;
4219 else if (lowequal
&& highequal
)
4220 in_p
= 0, low
= high
= 0;
4221 else if (subset
&& lowequal
)
4223 in_p
= 1, high
= high0
;
4224 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high1
, 0,
4225 integer_one_node
, 0);
4227 else if (! subset
|| highequal
)
4229 in_p
= 1, low
= low0
;
4230 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low1
, 0,
4231 integer_one_node
, 0);
4237 else if (! in0_p
&& in1_p
)
4239 /* If they don't overlap, the result is the second range. If the second
4240 is a subset of the first, the result is false. Otherwise,
4241 the range starts just after the first range and ends at the
4242 end of the second. */
4244 in_p
= 1, low
= low1
, high
= high1
;
4245 else if (subset
|| highequal
)
4246 in_p
= 0, low
= high
= 0;
4249 in_p
= 1, high
= high1
;
4250 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high0
, 1,
4251 integer_one_node
, 0);
4257 /* The case where we are excluding both ranges. Here the complex case
4258 is if they don't overlap. In that case, the only time we have a
4259 range is if they are adjacent. If the second is a subset of the
4260 first, the result is the first. Otherwise, the range to exclude
4261 starts at the beginning of the first range and ends at the end of the
4265 if (integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
4266 range_binop (PLUS_EXPR
, NULL_TREE
,
4268 integer_one_node
, 1),
4270 in_p
= 0, low
= low0
, high
= high1
;
4273 /* Canonicalize - [min, x] into - [-, x]. */
4274 if (low0
&& TREE_CODE (low0
) == INTEGER_CST
)
4275 switch (TREE_CODE (TREE_TYPE (low0
)))
4278 if (TYPE_PRECISION (TREE_TYPE (low0
))
4279 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0
))))
4284 if (tree_int_cst_equal (low0
,
4285 TYPE_MIN_VALUE (TREE_TYPE (low0
))))
4289 if (TYPE_UNSIGNED (TREE_TYPE (low0
))
4290 && integer_zerop (low0
))
4297 /* Canonicalize - [x, max] into - [x, -]. */
4298 if (high1
&& TREE_CODE (high1
) == INTEGER_CST
)
4299 switch (TREE_CODE (TREE_TYPE (high1
)))
4302 if (TYPE_PRECISION (TREE_TYPE (high1
))
4303 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1
))))
4308 if (tree_int_cst_equal (high1
,
4309 TYPE_MAX_VALUE (TREE_TYPE (high1
))))
4313 if (TYPE_UNSIGNED (TREE_TYPE (high1
))
4314 && integer_zerop (range_binop (PLUS_EXPR
, NULL_TREE
,
4316 integer_one_node
, 1)))
4323 /* The ranges might be also adjacent between the maximum and
4324 minimum values of the given type. For
4325 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4326 return + [x + 1, y - 1]. */
4327 if (low0
== 0 && high1
== 0)
4329 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high0
, 1,
4330 integer_one_node
, 1);
4331 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low1
, 0,
4332 integer_one_node
, 0);
4333 if (low
== 0 || high
== 0)
4343 in_p
= 0, low
= low0
, high
= high0
;
4345 in_p
= 0, low
= low0
, high
= high1
;
4348 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
4353 /* Subroutine of fold, looking inside expressions of the form
4354 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
4355 of the COND_EXPR. This function is being used also to optimize
4356 A op B ? C : A, by reversing the comparison first.
4358 Return a folded expression whose code is not a COND_EXPR
4359 anymore, or NULL_TREE if no folding opportunity is found. */
4362 fold_cond_expr_with_comparison (tree type
, tree arg0
, tree arg1
, tree arg2
)
4364 enum tree_code comp_code
= TREE_CODE (arg0
);
4365 tree arg00
= TREE_OPERAND (arg0
, 0);
4366 tree arg01
= TREE_OPERAND (arg0
, 1);
4367 tree arg1_type
= TREE_TYPE (arg1
);
4373 /* If we have A op 0 ? A : -A, consider applying the following
4376 A == 0? A : -A same as -A
4377 A != 0? A : -A same as A
4378 A >= 0? A : -A same as abs (A)
4379 A > 0? A : -A same as abs (A)
4380 A <= 0? A : -A same as -abs (A)
4381 A < 0? A : -A same as -abs (A)
4383 None of these transformations work for modes with signed
4384 zeros. If A is +/-0, the first two transformations will
4385 change the sign of the result (from +0 to -0, or vice
4386 versa). The last four will fix the sign of the result,
4387 even though the original expressions could be positive or
4388 negative, depending on the sign of A.
4390 Note that all these transformations are correct if A is
4391 NaN, since the two alternatives (A and -A) are also NaNs. */
4392 if ((FLOAT_TYPE_P (TREE_TYPE (arg01
))
4393 ? real_zerop (arg01
)
4394 : integer_zerop (arg01
))
4395 && ((TREE_CODE (arg2
) == NEGATE_EXPR
4396 && operand_equal_p (TREE_OPERAND (arg2
, 0), arg1
, 0))
4397 /* In the case that A is of the form X-Y, '-A' (arg2) may
4398 have already been folded to Y-X, check for that. */
4399 || (TREE_CODE (arg1
) == MINUS_EXPR
4400 && TREE_CODE (arg2
) == MINUS_EXPR
4401 && operand_equal_p (TREE_OPERAND (arg1
, 0),
4402 TREE_OPERAND (arg2
, 1), 0)
4403 && operand_equal_p (TREE_OPERAND (arg1
, 1),
4404 TREE_OPERAND (arg2
, 0), 0))))
4409 tem
= fold_convert (arg1_type
, arg1
);
4410 return pedantic_non_lvalue (fold_convert (type
, negate_expr (tem
)));
4413 return pedantic_non_lvalue (fold_convert (type
, arg1
));
4416 if (flag_trapping_math
)
4421 if (TYPE_UNSIGNED (TREE_TYPE (arg1
)))
4422 arg1
= fold_convert (lang_hooks
.types
.signed_type
4423 (TREE_TYPE (arg1
)), arg1
);
4424 tem
= fold_build1 (ABS_EXPR
, TREE_TYPE (arg1
), arg1
);
4425 return pedantic_non_lvalue (fold_convert (type
, tem
));
4428 if (flag_trapping_math
)
4432 if (TYPE_UNSIGNED (TREE_TYPE (arg1
)))
4433 arg1
= fold_convert (lang_hooks
.types
.signed_type
4434 (TREE_TYPE (arg1
)), arg1
);
4435 tem
= fold_build1 (ABS_EXPR
, TREE_TYPE (arg1
), arg1
);
4436 return negate_expr (fold_convert (type
, tem
));
4438 gcc_assert (TREE_CODE_CLASS (comp_code
) == tcc_comparison
);
4442 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4443 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4444 both transformations are correct when A is NaN: A != 0
4445 is then true, and A == 0 is false. */
4447 if (integer_zerop (arg01
) && integer_zerop (arg2
))
4449 if (comp_code
== NE_EXPR
)
4450 return pedantic_non_lvalue (fold_convert (type
, arg1
));
4451 else if (comp_code
== EQ_EXPR
)
4452 return build_int_cst (type
, 0);
4455 /* Try some transformations of A op B ? A : B.
4457 A == B? A : B same as B
4458 A != B? A : B same as A
4459 A >= B? A : B same as max (A, B)
4460 A > B? A : B same as max (B, A)
4461 A <= B? A : B same as min (A, B)
4462 A < B? A : B same as min (B, A)
4464 As above, these transformations don't work in the presence
4465 of signed zeros. For example, if A and B are zeros of
4466 opposite sign, the first two transformations will change
4467 the sign of the result. In the last four, the original
4468 expressions give different results for (A=+0, B=-0) and
4469 (A=-0, B=+0), but the transformed expressions do not.
4471 The first two transformations are correct if either A or B
4472 is a NaN. In the first transformation, the condition will
4473 be false, and B will indeed be chosen. In the case of the
4474 second transformation, the condition A != B will be true,
4475 and A will be chosen.
4477 The conversions to max() and min() are not correct if B is
4478 a number and A is not. The conditions in the original
4479 expressions will be false, so all four give B. The min()
4480 and max() versions would give a NaN instead. */
4481 if (operand_equal_for_comparison_p (arg01
, arg2
, arg00
)
4482 /* Avoid these transformations if the COND_EXPR may be used
4483 as an lvalue in the C++ front-end. PR c++/19199. */
4485 || strcmp (lang_hooks
.name
, "GNU C++") != 0
4486 || ! maybe_lvalue_p (arg1
)
4487 || ! maybe_lvalue_p (arg2
)))
4489 tree comp_op0
= arg00
;
4490 tree comp_op1
= arg01
;
4491 tree comp_type
= TREE_TYPE (comp_op0
);
4493 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4494 if (TYPE_MAIN_VARIANT (comp_type
) == TYPE_MAIN_VARIANT (type
))
4504 return pedantic_non_lvalue (fold_convert (type
, arg2
));
4506 return pedantic_non_lvalue (fold_convert (type
, arg1
));
4511 /* In C++ a ?: expression can be an lvalue, so put the
4512 operand which will be used if they are equal first
4513 so that we can convert this back to the
4514 corresponding COND_EXPR. */
4515 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
4517 comp_op0
= fold_convert (comp_type
, comp_op0
);
4518 comp_op1
= fold_convert (comp_type
, comp_op1
);
4519 tem
= (comp_code
== LE_EXPR
|| comp_code
== UNLE_EXPR
)
4520 ? fold_build2 (MIN_EXPR
, comp_type
, comp_op0
, comp_op1
)
4521 : fold_build2 (MIN_EXPR
, comp_type
, comp_op1
, comp_op0
);
4522 return pedantic_non_lvalue (fold_convert (type
, tem
));
4529 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
4531 comp_op0
= fold_convert (comp_type
, comp_op0
);
4532 comp_op1
= fold_convert (comp_type
, comp_op1
);
4533 tem
= (comp_code
== GE_EXPR
|| comp_code
== UNGE_EXPR
)
4534 ? fold_build2 (MAX_EXPR
, comp_type
, comp_op0
, comp_op1
)
4535 : fold_build2 (MAX_EXPR
, comp_type
, comp_op1
, comp_op0
);
4536 return pedantic_non_lvalue (fold_convert (type
, tem
));
4540 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
4541 return pedantic_non_lvalue (fold_convert (type
, arg2
));
4544 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
4545 return pedantic_non_lvalue (fold_convert (type
, arg1
));
4548 gcc_assert (TREE_CODE_CLASS (comp_code
) == tcc_comparison
);
4553 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
4554 we might still be able to simplify this. For example,
4555 if C1 is one less or one more than C2, this might have started
4556 out as a MIN or MAX and been transformed by this function.
4557 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
4559 if (INTEGRAL_TYPE_P (type
)
4560 && TREE_CODE (arg01
) == INTEGER_CST
4561 && TREE_CODE (arg2
) == INTEGER_CST
)
4565 /* We can replace A with C1 in this case. */
4566 arg1
= fold_convert (type
, arg01
);
4567 return fold_build3 (COND_EXPR
, type
, arg0
, arg1
, arg2
);
4570 /* If C1 is C2 + 1, this is min(A, C2). */
4571 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
),
4573 && operand_equal_p (arg01
,
4574 const_binop (PLUS_EXPR
, arg2
,
4575 integer_one_node
, 0),
4577 return pedantic_non_lvalue (fold_build2 (MIN_EXPR
,
4582 /* If C1 is C2 - 1, this is min(A, C2). */
4583 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
),
4585 && operand_equal_p (arg01
,
4586 const_binop (MINUS_EXPR
, arg2
,
4587 integer_one_node
, 0),
4589 return pedantic_non_lvalue (fold_build2 (MIN_EXPR
,
4594 /* If C1 is C2 - 1, this is max(A, C2). */
4595 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
),
4597 && operand_equal_p (arg01
,
4598 const_binop (MINUS_EXPR
, arg2
,
4599 integer_one_node
, 0),
4601 return pedantic_non_lvalue (fold_build2 (MAX_EXPR
,
4606 /* If C1 is C2 + 1, this is max(A, C2). */
4607 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
),
4609 && operand_equal_p (arg01
,
4610 const_binop (PLUS_EXPR
, arg2
,
4611 integer_one_node
, 0),
4613 return pedantic_non_lvalue (fold_build2 (MAX_EXPR
,
4627 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
4628 #define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
4631 /* EXP is some logical combination of boolean tests. See if we can
4632 merge it into some range test. Return the new tree if so. */
4635 fold_range_test (enum tree_code code
, tree type
, tree op0
, tree op1
)
4637 int or_op
= (code
== TRUTH_ORIF_EXPR
4638 || code
== TRUTH_OR_EXPR
);
4639 int in0_p
, in1_p
, in_p
;
4640 tree low0
, low1
, low
, high0
, high1
, high
;
4641 tree lhs
= make_range (op0
, &in0_p
, &low0
, &high0
);
4642 tree rhs
= make_range (op1
, &in1_p
, &low1
, &high1
);
4645 /* If this is an OR operation, invert both sides; we will invert
4646 again at the end. */
4648 in0_p
= ! in0_p
, in1_p
= ! in1_p
;
4650 /* If both expressions are the same, if we can merge the ranges, and we
4651 can build the range test, return it or it inverted. If one of the
4652 ranges is always true or always false, consider it to be the same
4653 expression as the other. */
4654 if ((lhs
== 0 || rhs
== 0 || operand_equal_p (lhs
, rhs
, 0))
4655 && merge_ranges (&in_p
, &low
, &high
, in0_p
, low0
, high0
,
4657 && 0 != (tem
= (build_range_check (type
,
4659 : rhs
!= 0 ? rhs
: integer_zero_node
,
4661 return or_op
? invert_truthvalue (tem
) : tem
;
4663 /* On machines where the branch cost is expensive, if this is a
4664 short-circuited branch and the underlying object on both sides
4665 is the same, make a non-short-circuit operation. */
4666 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
4667 && lhs
!= 0 && rhs
!= 0
4668 && (code
== TRUTH_ANDIF_EXPR
4669 || code
== TRUTH_ORIF_EXPR
)
4670 && operand_equal_p (lhs
, rhs
, 0))
4672 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
4673 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
4674 which cases we can't do this. */
4675 if (simple_operand_p (lhs
))
4676 return build2 (code
== TRUTH_ANDIF_EXPR
4677 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
4680 else if (lang_hooks
.decls
.global_bindings_p () == 0
4681 && ! CONTAINS_PLACEHOLDER_P (lhs
))
4683 tree common
= save_expr (lhs
);
4685 if (0 != (lhs
= build_range_check (type
, common
,
4686 or_op
? ! in0_p
: in0_p
,
4688 && (0 != (rhs
= build_range_check (type
, common
,
4689 or_op
? ! in1_p
: in1_p
,
4691 return build2 (code
== TRUTH_ANDIF_EXPR
4692 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
4700 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
4701 bit value. Arrange things so the extra bits will be set to zero if and
4702 only if C is signed-extended to its full width. If MASK is nonzero,
4703 it is an INTEGER_CST that should be AND'ed with the extra bits. */
4706 unextend (tree c
, int p
, int unsignedp
, tree mask
)
4708 tree type
= TREE_TYPE (c
);
4709 int modesize
= GET_MODE_BITSIZE (TYPE_MODE (type
));
4712 if (p
== modesize
|| unsignedp
)
4715 /* We work by getting just the sign bit into the low-order bit, then
4716 into the high-order bit, then sign-extend. We then XOR that value
4718 temp
= const_binop (RSHIFT_EXPR
, c
, size_int (p
- 1), 0);
4719 temp
= const_binop (BIT_AND_EXPR
, temp
, size_int (1), 0);
4721 /* We must use a signed type in order to get an arithmetic right shift.
4722 However, we must also avoid introducing accidental overflows, so that
4723 a subsequent call to integer_zerop will work. Hence we must
4724 do the type conversion here. At this point, the constant is either
4725 zero or one, and the conversion to a signed type can never overflow.
4726 We could get an overflow if this conversion is done anywhere else. */
4727 if (TYPE_UNSIGNED (type
))
4728 temp
= fold_convert (lang_hooks
.types
.signed_type (type
), temp
);
4730 temp
= const_binop (LSHIFT_EXPR
, temp
, size_int (modesize
- 1), 0);
4731 temp
= const_binop (RSHIFT_EXPR
, temp
, size_int (modesize
- p
- 1), 0);
4733 temp
= const_binop (BIT_AND_EXPR
, temp
,
4734 fold_convert (TREE_TYPE (c
), mask
), 0);
4735 /* If necessary, convert the type back to match the type of C. */
4736 if (TYPE_UNSIGNED (type
))
4737 temp
= fold_convert (type
, temp
);
4739 return fold_convert (type
, const_binop (BIT_XOR_EXPR
, c
, temp
, 0));
4742 /* Find ways of folding logical expressions of LHS and RHS:
4743 Try to merge two comparisons to the same innermost item.
4744 Look for range tests like "ch >= '0' && ch <= '9'".
4745 Look for combinations of simple terms on machines with expensive branches
4746 and evaluate the RHS unconditionally.
4748 For example, if we have p->a == 2 && p->b == 4 and we can make an
4749 object large enough to span both A and B, we can do this with a comparison
4750 against the object ANDed with the a mask.
4752 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
4753 operations to do this with one comparison.
4755 We check for both normal comparisons and the BIT_AND_EXPRs made this by
4756 function and the one above.
4758 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
4759 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
4761 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
4764 We return the simplified tree or 0 if no optimization is possible. */
4767 fold_truthop (enum tree_code code
, tree truth_type
, tree lhs
, tree rhs
)
4769 /* If this is the "or" of two comparisons, we can do something if
4770 the comparisons are NE_EXPR. If this is the "and", we can do something
4771 if the comparisons are EQ_EXPR. I.e.,
4772 (a->b == 2 && a->c == 4) can become (a->new == NEW).
4774 WANTED_CODE is this operation code. For single bit fields, we can
4775 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
4776 comparison for one-bit fields. */
4778 enum tree_code wanted_code
;
4779 enum tree_code lcode
, rcode
;
4780 tree ll_arg
, lr_arg
, rl_arg
, rr_arg
;
4781 tree ll_inner
, lr_inner
, rl_inner
, rr_inner
;
4782 HOST_WIDE_INT ll_bitsize
, ll_bitpos
, lr_bitsize
, lr_bitpos
;
4783 HOST_WIDE_INT rl_bitsize
, rl_bitpos
, rr_bitsize
, rr_bitpos
;
4784 HOST_WIDE_INT xll_bitpos
, xlr_bitpos
, xrl_bitpos
, xrr_bitpos
;
4785 HOST_WIDE_INT lnbitsize
, lnbitpos
, rnbitsize
, rnbitpos
;
4786 int ll_unsignedp
, lr_unsignedp
, rl_unsignedp
, rr_unsignedp
;
4787 enum machine_mode ll_mode
, lr_mode
, rl_mode
, rr_mode
;
4788 enum machine_mode lnmode
, rnmode
;
4789 tree ll_mask
, lr_mask
, rl_mask
, rr_mask
;
4790 tree ll_and_mask
, lr_and_mask
, rl_and_mask
, rr_and_mask
;
4791 tree l_const
, r_const
;
4792 tree lntype
, rntype
, result
;
4793 int first_bit
, end_bit
;
4796 /* Start by getting the comparison codes. Fail if anything is volatile.
4797 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
4798 it were surrounded with a NE_EXPR. */
4800 if (TREE_SIDE_EFFECTS (lhs
) || TREE_SIDE_EFFECTS (rhs
))
4803 lcode
= TREE_CODE (lhs
);
4804 rcode
= TREE_CODE (rhs
);
4806 if (lcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (lhs
, 1)))
4808 lhs
= build2 (NE_EXPR
, truth_type
, lhs
,
4809 build_int_cst (TREE_TYPE (lhs
), 0));
4813 if (rcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (rhs
, 1)))
4815 rhs
= build2 (NE_EXPR
, truth_type
, rhs
,
4816 build_int_cst (TREE_TYPE (rhs
), 0));
4820 if (TREE_CODE_CLASS (lcode
) != tcc_comparison
4821 || TREE_CODE_CLASS (rcode
) != tcc_comparison
)
4824 ll_arg
= TREE_OPERAND (lhs
, 0);
4825 lr_arg
= TREE_OPERAND (lhs
, 1);
4826 rl_arg
= TREE_OPERAND (rhs
, 0);
4827 rr_arg
= TREE_OPERAND (rhs
, 1);
4829 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
4830 if (simple_operand_p (ll_arg
)
4831 && simple_operand_p (lr_arg
))
4834 if (operand_equal_p (ll_arg
, rl_arg
, 0)
4835 && operand_equal_p (lr_arg
, rr_arg
, 0))
4837 result
= combine_comparisons (code
, lcode
, rcode
,
4838 truth_type
, ll_arg
, lr_arg
);
4842 else if (operand_equal_p (ll_arg
, rr_arg
, 0)
4843 && operand_equal_p (lr_arg
, rl_arg
, 0))
4845 result
= combine_comparisons (code
, lcode
,
4846 swap_tree_comparison (rcode
),
4847 truth_type
, ll_arg
, lr_arg
);
4853 code
= ((code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
)
4854 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
);
4856 /* If the RHS can be evaluated unconditionally and its operands are
4857 simple, it wins to evaluate the RHS unconditionally on machines
4858 with expensive branches. In this case, this isn't a comparison
4859 that can be merged. Avoid doing this if the RHS is a floating-point
4860 comparison since those can trap. */
4862 if (BRANCH_COST
>= 2
4863 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg
))
4864 && simple_operand_p (rl_arg
)
4865 && simple_operand_p (rr_arg
))
4867 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
4868 if (code
== TRUTH_OR_EXPR
4869 && lcode
== NE_EXPR
&& integer_zerop (lr_arg
)
4870 && rcode
== NE_EXPR
&& integer_zerop (rr_arg
)
4871 && TREE_TYPE (ll_arg
) == TREE_TYPE (rl_arg
))
4872 return build2 (NE_EXPR
, truth_type
,
4873 build2 (BIT_IOR_EXPR
, TREE_TYPE (ll_arg
),
4875 build_int_cst (TREE_TYPE (ll_arg
), 0));
4877 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
4878 if (code
== TRUTH_AND_EXPR
4879 && lcode
== EQ_EXPR
&& integer_zerop (lr_arg
)
4880 && rcode
== EQ_EXPR
&& integer_zerop (rr_arg
)
4881 && TREE_TYPE (ll_arg
) == TREE_TYPE (rl_arg
))
4882 return build2 (EQ_EXPR
, truth_type
,
4883 build2 (BIT_IOR_EXPR
, TREE_TYPE (ll_arg
),
4885 build_int_cst (TREE_TYPE (ll_arg
), 0));
4887 if (LOGICAL_OP_NON_SHORT_CIRCUIT
)
4888 return build2 (code
, truth_type
, lhs
, rhs
);
4891 /* See if the comparisons can be merged. Then get all the parameters for
4894 if ((lcode
!= EQ_EXPR
&& lcode
!= NE_EXPR
)
4895 || (rcode
!= EQ_EXPR
&& rcode
!= NE_EXPR
))
4899 ll_inner
= decode_field_reference (ll_arg
,
4900 &ll_bitsize
, &ll_bitpos
, &ll_mode
,
4901 &ll_unsignedp
, &volatilep
, &ll_mask
,
4903 lr_inner
= decode_field_reference (lr_arg
,
4904 &lr_bitsize
, &lr_bitpos
, &lr_mode
,
4905 &lr_unsignedp
, &volatilep
, &lr_mask
,
4907 rl_inner
= decode_field_reference (rl_arg
,
4908 &rl_bitsize
, &rl_bitpos
, &rl_mode
,
4909 &rl_unsignedp
, &volatilep
, &rl_mask
,
4911 rr_inner
= decode_field_reference (rr_arg
,
4912 &rr_bitsize
, &rr_bitpos
, &rr_mode
,
4913 &rr_unsignedp
, &volatilep
, &rr_mask
,
4916 /* It must be true that the inner operation on the lhs of each
4917 comparison must be the same if we are to be able to do anything.
4918 Then see if we have constants. If not, the same must be true for
4920 if (volatilep
|| ll_inner
== 0 || rl_inner
== 0
4921 || ! operand_equal_p (ll_inner
, rl_inner
, 0))
4924 if (TREE_CODE (lr_arg
) == INTEGER_CST
4925 && TREE_CODE (rr_arg
) == INTEGER_CST
)
4926 l_const
= lr_arg
, r_const
= rr_arg
;
4927 else if (lr_inner
== 0 || rr_inner
== 0
4928 || ! operand_equal_p (lr_inner
, rr_inner
, 0))
4931 l_const
= r_const
= 0;
4933 /* If either comparison code is not correct for our logical operation,
4934 fail. However, we can convert a one-bit comparison against zero into
4935 the opposite comparison against that bit being set in the field. */
4937 wanted_code
= (code
== TRUTH_AND_EXPR
? EQ_EXPR
: NE_EXPR
);
4938 if (lcode
!= wanted_code
)
4940 if (l_const
&& integer_zerop (l_const
) && integer_pow2p (ll_mask
))
4942 /* Make the left operand unsigned, since we are only interested
4943 in the value of one bit. Otherwise we are doing the wrong
4952 /* This is analogous to the code for l_const above. */
4953 if (rcode
!= wanted_code
)
4955 if (r_const
&& integer_zerop (r_const
) && integer_pow2p (rl_mask
))
4964 /* After this point all optimizations will generate bit-field
4965 references, which we might not want. */
4966 if (! lang_hooks
.can_use_bit_fields_p ())
4969 /* See if we can find a mode that contains both fields being compared on
4970 the left. If we can't, fail. Otherwise, update all constants and masks
4971 to be relative to a field of that size. */
4972 first_bit
= MIN (ll_bitpos
, rl_bitpos
);
4973 end_bit
= MAX (ll_bitpos
+ ll_bitsize
, rl_bitpos
+ rl_bitsize
);
4974 lnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
4975 TYPE_ALIGN (TREE_TYPE (ll_inner
)), word_mode
,
4977 if (lnmode
== VOIDmode
)
4980 lnbitsize
= GET_MODE_BITSIZE (lnmode
);
4981 lnbitpos
= first_bit
& ~ (lnbitsize
- 1);
4982 lntype
= lang_hooks
.types
.type_for_size (lnbitsize
, 1);
4983 xll_bitpos
= ll_bitpos
- lnbitpos
, xrl_bitpos
= rl_bitpos
- lnbitpos
;
4985 if (BYTES_BIG_ENDIAN
)
4987 xll_bitpos
= lnbitsize
- xll_bitpos
- ll_bitsize
;
4988 xrl_bitpos
= lnbitsize
- xrl_bitpos
- rl_bitsize
;
4991 ll_mask
= const_binop (LSHIFT_EXPR
, fold_convert (lntype
, ll_mask
),
4992 size_int (xll_bitpos
), 0);
4993 rl_mask
= const_binop (LSHIFT_EXPR
, fold_convert (lntype
, rl_mask
),
4994 size_int (xrl_bitpos
), 0);
4998 l_const
= fold_convert (lntype
, l_const
);
4999 l_const
= unextend (l_const
, ll_bitsize
, ll_unsignedp
, ll_and_mask
);
5000 l_const
= const_binop (LSHIFT_EXPR
, l_const
, size_int (xll_bitpos
), 0);
5001 if (! integer_zerop (const_binop (BIT_AND_EXPR
, l_const
,
5002 fold_build1 (BIT_NOT_EXPR
,
5006 warning (0, "comparison is always %d", wanted_code
== NE_EXPR
);
5008 return constant_boolean_node (wanted_code
== NE_EXPR
, truth_type
);
5013 r_const
= fold_convert (lntype
, r_const
);
5014 r_const
= unextend (r_const
, rl_bitsize
, rl_unsignedp
, rl_and_mask
);
5015 r_const
= const_binop (LSHIFT_EXPR
, r_const
, size_int (xrl_bitpos
), 0);
5016 if (! integer_zerop (const_binop (BIT_AND_EXPR
, r_const
,
5017 fold_build1 (BIT_NOT_EXPR
,
5021 warning (0, "comparison is always %d", wanted_code
== NE_EXPR
);
5023 return constant_boolean_node (wanted_code
== NE_EXPR
, truth_type
);
5027 /* If the right sides are not constant, do the same for it. Also,
5028 disallow this optimization if a size or signedness mismatch occurs
5029 between the left and right sides. */
5032 if (ll_bitsize
!= lr_bitsize
|| rl_bitsize
!= rr_bitsize
5033 || ll_unsignedp
!= lr_unsignedp
|| rl_unsignedp
!= rr_unsignedp
5034 /* Make sure the two fields on the right
5035 correspond to the left without being swapped. */
5036 || ll_bitpos
- rl_bitpos
!= lr_bitpos
- rr_bitpos
)
5039 first_bit
= MIN (lr_bitpos
, rr_bitpos
);
5040 end_bit
= MAX (lr_bitpos
+ lr_bitsize
, rr_bitpos
+ rr_bitsize
);
5041 rnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
5042 TYPE_ALIGN (TREE_TYPE (lr_inner
)), word_mode
,
5044 if (rnmode
== VOIDmode
)
5047 rnbitsize
= GET_MODE_BITSIZE (rnmode
);
5048 rnbitpos
= first_bit
& ~ (rnbitsize
- 1);
5049 rntype
= lang_hooks
.types
.type_for_size (rnbitsize
, 1);
5050 xlr_bitpos
= lr_bitpos
- rnbitpos
, xrr_bitpos
= rr_bitpos
- rnbitpos
;
5052 if (BYTES_BIG_ENDIAN
)
5054 xlr_bitpos
= rnbitsize
- xlr_bitpos
- lr_bitsize
;
5055 xrr_bitpos
= rnbitsize
- xrr_bitpos
- rr_bitsize
;
5058 lr_mask
= const_binop (LSHIFT_EXPR
, fold_convert (rntype
, lr_mask
),
5059 size_int (xlr_bitpos
), 0);
5060 rr_mask
= const_binop (LSHIFT_EXPR
, fold_convert (rntype
, rr_mask
),
5061 size_int (xrr_bitpos
), 0);
5063 /* Make a mask that corresponds to both fields being compared.
5064 Do this for both items being compared. If the operands are the
5065 same size and the bits being compared are in the same position
5066 then we can do this by masking both and comparing the masked
5068 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
5069 lr_mask
= const_binop (BIT_IOR_EXPR
, lr_mask
, rr_mask
, 0);
5070 if (lnbitsize
== rnbitsize
&& xll_bitpos
== xlr_bitpos
)
5072 lhs
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
5073 ll_unsignedp
|| rl_unsignedp
);
5074 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
5075 lhs
= build2 (BIT_AND_EXPR
, lntype
, lhs
, ll_mask
);
5077 rhs
= make_bit_field_ref (lr_inner
, rntype
, rnbitsize
, rnbitpos
,
5078 lr_unsignedp
|| rr_unsignedp
);
5079 if (! all_ones_mask_p (lr_mask
, rnbitsize
))
5080 rhs
= build2 (BIT_AND_EXPR
, rntype
, rhs
, lr_mask
);
5082 return build2 (wanted_code
, truth_type
, lhs
, rhs
);
5085 /* There is still another way we can do something: If both pairs of
5086 fields being compared are adjacent, we may be able to make a wider
5087 field containing them both.
5089 Note that we still must mask the lhs/rhs expressions. Furthermore,
5090 the mask must be shifted to account for the shift done by
5091 make_bit_field_ref. */
5092 if ((ll_bitsize
+ ll_bitpos
== rl_bitpos
5093 && lr_bitsize
+ lr_bitpos
== rr_bitpos
)
5094 || (ll_bitpos
== rl_bitpos
+ rl_bitsize
5095 && lr_bitpos
== rr_bitpos
+ rr_bitsize
))
5099 lhs
= make_bit_field_ref (ll_inner
, lntype
, ll_bitsize
+ rl_bitsize
,
5100 MIN (ll_bitpos
, rl_bitpos
), ll_unsignedp
);
5101 rhs
= make_bit_field_ref (lr_inner
, rntype
, lr_bitsize
+ rr_bitsize
,
5102 MIN (lr_bitpos
, rr_bitpos
), lr_unsignedp
);
5104 ll_mask
= const_binop (RSHIFT_EXPR
, ll_mask
,
5105 size_int (MIN (xll_bitpos
, xrl_bitpos
)), 0);
5106 lr_mask
= const_binop (RSHIFT_EXPR
, lr_mask
,
5107 size_int (MIN (xlr_bitpos
, xrr_bitpos
)), 0);
5109 /* Convert to the smaller type before masking out unwanted bits. */
5111 if (lntype
!= rntype
)
5113 if (lnbitsize
> rnbitsize
)
5115 lhs
= fold_convert (rntype
, lhs
);
5116 ll_mask
= fold_convert (rntype
, ll_mask
);
5119 else if (lnbitsize
< rnbitsize
)
5121 rhs
= fold_convert (lntype
, rhs
);
5122 lr_mask
= fold_convert (lntype
, lr_mask
);
5127 if (! all_ones_mask_p (ll_mask
, ll_bitsize
+ rl_bitsize
))
5128 lhs
= build2 (BIT_AND_EXPR
, type
, lhs
, ll_mask
);
5130 if (! all_ones_mask_p (lr_mask
, lr_bitsize
+ rr_bitsize
))
5131 rhs
= build2 (BIT_AND_EXPR
, type
, rhs
, lr_mask
);
5133 return build2 (wanted_code
, truth_type
, lhs
, rhs
);
5139 /* Handle the case of comparisons with constants. If there is something in
5140 common between the masks, those bits of the constants must be the same.
5141 If not, the condition is always false. Test for this to avoid generating
5142 incorrect code below. */
5143 result
= const_binop (BIT_AND_EXPR
, ll_mask
, rl_mask
, 0);
5144 if (! integer_zerop (result
)
5145 && simple_cst_equal (const_binop (BIT_AND_EXPR
, result
, l_const
, 0),
5146 const_binop (BIT_AND_EXPR
, result
, r_const
, 0)) != 1)
5148 if (wanted_code
== NE_EXPR
)
5150 warning (0, "%<or%> of unmatched not-equal tests is always 1");
5151 return constant_boolean_node (true, truth_type
);
5155 warning (0, "%<and%> of mutually exclusive equal-tests is always 0");
5156 return constant_boolean_node (false, truth_type
);
5160 /* Construct the expression we will return. First get the component
5161 reference we will make. Unless the mask is all ones the width of
5162 that field, perform the mask operation. Then compare with the
5164 result
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
5165 ll_unsignedp
|| rl_unsignedp
);
5167 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
5168 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
5169 result
= build2 (BIT_AND_EXPR
, lntype
, result
, ll_mask
);
5171 return build2 (wanted_code
, truth_type
, result
,
5172 const_binop (BIT_IOR_EXPR
, l_const
, r_const
, 0));
5175 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
5179 optimize_minmax_comparison (enum tree_code code
, tree type
, tree op0
, tree op1
)
5182 enum tree_code op_code
;
5183 tree comp_const
= op1
;
5185 int consts_equal
, consts_lt
;
5188 STRIP_SIGN_NOPS (arg0
);
5190 op_code
= TREE_CODE (arg0
);
5191 minmax_const
= TREE_OPERAND (arg0
, 1);
5192 consts_equal
= tree_int_cst_equal (minmax_const
, comp_const
);
5193 consts_lt
= tree_int_cst_lt (minmax_const
, comp_const
);
5194 inner
= TREE_OPERAND (arg0
, 0);
5196 /* If something does not permit us to optimize, return the original tree. */
5197 if ((op_code
!= MIN_EXPR
&& op_code
!= MAX_EXPR
)
5198 || TREE_CODE (comp_const
) != INTEGER_CST
5199 || TREE_CONSTANT_OVERFLOW (comp_const
)
5200 || TREE_CODE (minmax_const
) != INTEGER_CST
5201 || TREE_CONSTANT_OVERFLOW (minmax_const
))
5204 /* Now handle all the various comparison codes. We only handle EQ_EXPR
5205 and GT_EXPR, doing the rest with recursive calls using logical
5209 case NE_EXPR
: case LT_EXPR
: case LE_EXPR
:
5211 /* FIXME: We should be able to invert code without building a
5212 scratch tree node, but doing so would require us to
5213 duplicate a part of invert_truthvalue here. */
5214 tree tem
= invert_truthvalue (build2 (code
, type
, op0
, op1
));
5215 tem
= optimize_minmax_comparison (TREE_CODE (tem
),
5217 TREE_OPERAND (tem
, 0),
5218 TREE_OPERAND (tem
, 1));
5219 return invert_truthvalue (tem
);
5224 fold_build2 (TRUTH_ORIF_EXPR
, type
,
5225 optimize_minmax_comparison
5226 (EQ_EXPR
, type
, arg0
, comp_const
),
5227 optimize_minmax_comparison
5228 (GT_EXPR
, type
, arg0
, comp_const
));
5231 if (op_code
== MAX_EXPR
&& consts_equal
)
5232 /* MAX (X, 0) == 0 -> X <= 0 */
5233 return fold_build2 (LE_EXPR
, type
, inner
, comp_const
);
5235 else if (op_code
== MAX_EXPR
&& consts_lt
)
5236 /* MAX (X, 0) == 5 -> X == 5 */
5237 return fold_build2 (EQ_EXPR
, type
, inner
, comp_const
);
5239 else if (op_code
== MAX_EXPR
)
5240 /* MAX (X, 0) == -1 -> false */
5241 return omit_one_operand (type
, integer_zero_node
, inner
);
5243 else if (consts_equal
)
5244 /* MIN (X, 0) == 0 -> X >= 0 */
5245 return fold_build2 (GE_EXPR
, type
, inner
, comp_const
);
5248 /* MIN (X, 0) == 5 -> false */
5249 return omit_one_operand (type
, integer_zero_node
, inner
);
5252 /* MIN (X, 0) == -1 -> X == -1 */
5253 return fold_build2 (EQ_EXPR
, type
, inner
, comp_const
);
5256 if (op_code
== MAX_EXPR
&& (consts_equal
|| consts_lt
))
5257 /* MAX (X, 0) > 0 -> X > 0
5258 MAX (X, 0) > 5 -> X > 5 */
5259 return fold_build2 (GT_EXPR
, type
, inner
, comp_const
);
5261 else if (op_code
== MAX_EXPR
)
5262 /* MAX (X, 0) > -1 -> true */
5263 return omit_one_operand (type
, integer_one_node
, inner
);
5265 else if (op_code
== MIN_EXPR
&& (consts_equal
|| consts_lt
))
5266 /* MIN (X, 0) > 0 -> false
5267 MIN (X, 0) > 5 -> false */
5268 return omit_one_operand (type
, integer_zero_node
, inner
);
5271 /* MIN (X, 0) > -1 -> X > -1 */
5272 return fold_build2 (GT_EXPR
, type
, inner
, comp_const
);
5279 /* T is an integer expression that is being multiplied, divided, or taken a
5280 modulus (CODE says which and what kind of divide or modulus) by a
5281 constant C. See if we can eliminate that operation by folding it with
5282 other operations already in T. WIDE_TYPE, if non-null, is a type that
5283 should be used for the computation if wider than our type.
5285 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5286 (X * 2) + (Y * 4). We must, however, be assured that either the original
5287 expression would not overflow or that overflow is undefined for the type
5288 in the language in question.
5290 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5291 the machine has a multiply-accumulate insn or that this is part of an
5292 addressing calculation.
5294 If we return a non-null expression, it is an equivalent form of the
5295 original computation, but need not be in the original type. */
5298 extract_muldiv (tree t
, tree c
, enum tree_code code
, tree wide_type
)
5300 /* To avoid exponential search depth, refuse to allow recursion past
5301 three levels. Beyond that (1) it's highly unlikely that we'll find
5302 something interesting and (2) we've probably processed it before
5303 when we built the inner expression. */
5312 ret
= extract_muldiv_1 (t
, c
, code
, wide_type
);
5319 extract_muldiv_1 (tree t
, tree c
, enum tree_code code
, tree wide_type
)
5321 tree type
= TREE_TYPE (t
);
5322 enum tree_code tcode
= TREE_CODE (t
);
5323 tree ctype
= (wide_type
!= 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type
))
5324 > GET_MODE_SIZE (TYPE_MODE (type
)))
5325 ? wide_type
: type
);
5327 int same_p
= tcode
== code
;
5328 tree op0
= NULL_TREE
, op1
= NULL_TREE
;
5330 /* Don't deal with constants of zero here; they confuse the code below. */
5331 if (integer_zerop (c
))
5334 if (TREE_CODE_CLASS (tcode
) == tcc_unary
)
5335 op0
= TREE_OPERAND (t
, 0);
5337 if (TREE_CODE_CLASS (tcode
) == tcc_binary
)
5338 op0
= TREE_OPERAND (t
, 0), op1
= TREE_OPERAND (t
, 1);
5340 /* Note that we need not handle conditional operations here since fold
5341 already handles those cases. So just do arithmetic here. */
5345 /* For a constant, we can always simplify if we are a multiply
5346 or (for divide and modulus) if it is a multiple of our constant. */
5347 if (code
== MULT_EXPR
5348 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, t
, c
, 0)))
5349 return const_binop (code
, fold_convert (ctype
, t
),
5350 fold_convert (ctype
, c
), 0);
5353 case CONVERT_EXPR
: case NON_LVALUE_EXPR
: case NOP_EXPR
:
5354 /* If op0 is an expression ... */
5355 if ((COMPARISON_CLASS_P (op0
)
5356 || UNARY_CLASS_P (op0
)
5357 || BINARY_CLASS_P (op0
)
5358 || EXPRESSION_CLASS_P (op0
))
5359 /* ... and is unsigned, and its type is smaller than ctype,
5360 then we cannot pass through as widening. */
5361 && ((TYPE_UNSIGNED (TREE_TYPE (op0
))
5362 && ! (TREE_CODE (TREE_TYPE (op0
)) == INTEGER_TYPE
5363 && TYPE_IS_SIZETYPE (TREE_TYPE (op0
)))
5364 && (GET_MODE_SIZE (TYPE_MODE (ctype
))
5365 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
)))))
5366 /* ... or this is a truncation (t is narrower than op0),
5367 then we cannot pass through this narrowing. */
5368 || (GET_MODE_SIZE (TYPE_MODE (type
))
5369 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
))))
5370 /* ... or signedness changes for division or modulus,
5371 then we cannot pass through this conversion. */
5372 || (code
!= MULT_EXPR
5373 && (TYPE_UNSIGNED (ctype
)
5374 != TYPE_UNSIGNED (TREE_TYPE (op0
))))))
5377 /* Pass the constant down and see if we can make a simplification. If
5378 we can, replace this expression with the inner simplification for
5379 possible later conversion to our or some other type. */
5380 if ((t2
= fold_convert (TREE_TYPE (op0
), c
)) != 0
5381 && TREE_CODE (t2
) == INTEGER_CST
5382 && ! TREE_CONSTANT_OVERFLOW (t2
)
5383 && (0 != (t1
= extract_muldiv (op0
, t2
, code
,
5385 ? ctype
: NULL_TREE
))))
5390 /* If widening the type changes it from signed to unsigned, then we
5391 must avoid building ABS_EXPR itself as unsigned. */
5392 if (TYPE_UNSIGNED (ctype
) && !TYPE_UNSIGNED (type
))
5394 tree cstype
= (*lang_hooks
.types
.signed_type
) (ctype
);
5395 if ((t1
= extract_muldiv (op0
, c
, code
, cstype
)) != 0)
5397 t1
= fold_build1 (tcode
, cstype
, fold_convert (cstype
, t1
));
5398 return fold_convert (ctype
, t1
);
5404 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
5405 return fold_build1 (tcode
, ctype
, fold_convert (ctype
, t1
));
5408 case MIN_EXPR
: case MAX_EXPR
:
5409 /* If widening the type changes the signedness, then we can't perform
5410 this optimization as that changes the result. */
5411 if (TYPE_UNSIGNED (ctype
) != TYPE_UNSIGNED (type
))
5414 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5415 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0
5416 && (t2
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
5418 if (tree_int_cst_sgn (c
) < 0)
5419 tcode
= (tcode
== MIN_EXPR
? MAX_EXPR
: MIN_EXPR
);
5421 return fold_build2 (tcode
, ctype
, fold_convert (ctype
, t1
),
5422 fold_convert (ctype
, t2
));
5426 case LSHIFT_EXPR
: case RSHIFT_EXPR
:
5427 /* If the second operand is constant, this is a multiplication
5428 or floor division, by a power of two, so we can treat it that
5429 way unless the multiplier or divisor overflows. Signed
5430 left-shift overflow is implementation-defined rather than
5431 undefined in C90, so do not convert signed left shift into
5433 if (TREE_CODE (op1
) == INTEGER_CST
5434 && (tcode
== RSHIFT_EXPR
|| TYPE_UNSIGNED (TREE_TYPE (op0
)))
5435 /* const_binop may not detect overflow correctly,
5436 so check for it explicitly here. */
5437 && TYPE_PRECISION (TREE_TYPE (size_one_node
)) > TREE_INT_CST_LOW (op1
)
5438 && TREE_INT_CST_HIGH (op1
) == 0
5439 && 0 != (t1
= fold_convert (ctype
,
5440 const_binop (LSHIFT_EXPR
,
5443 && ! TREE_OVERFLOW (t1
))
5444 return extract_muldiv (build2 (tcode
== LSHIFT_EXPR
5445 ? MULT_EXPR
: FLOOR_DIV_EXPR
,
5446 ctype
, fold_convert (ctype
, op0
), t1
),
5447 c
, code
, wide_type
);
5450 case PLUS_EXPR
: case MINUS_EXPR
:
5451 /* See if we can eliminate the operation on both sides. If we can, we
5452 can return a new PLUS or MINUS. If we can't, the only remaining
5453 cases where we can do anything are if the second operand is a
5455 t1
= extract_muldiv (op0
, c
, code
, wide_type
);
5456 t2
= extract_muldiv (op1
, c
, code
, wide_type
);
5457 if (t1
!= 0 && t2
!= 0
5458 && (code
== MULT_EXPR
5459 /* If not multiplication, we can only do this if both operands
5460 are divisible by c. */
5461 || (multiple_of_p (ctype
, op0
, c
)
5462 && multiple_of_p (ctype
, op1
, c
))))
5463 return fold_build2 (tcode
, ctype
, fold_convert (ctype
, t1
),
5464 fold_convert (ctype
, t2
));
5466 /* If this was a subtraction, negate OP1 and set it to be an addition.
5467 This simplifies the logic below. */
5468 if (tcode
== MINUS_EXPR
)
5469 tcode
= PLUS_EXPR
, op1
= negate_expr (op1
);
5471 if (TREE_CODE (op1
) != INTEGER_CST
)
5474 /* If either OP1 or C are negative, this optimization is not safe for
5475 some of the division and remainder types while for others we need
5476 to change the code. */
5477 if (tree_int_cst_sgn (op1
) < 0 || tree_int_cst_sgn (c
) < 0)
5479 if (code
== CEIL_DIV_EXPR
)
5480 code
= FLOOR_DIV_EXPR
;
5481 else if (code
== FLOOR_DIV_EXPR
)
5482 code
= CEIL_DIV_EXPR
;
5483 else if (code
!= MULT_EXPR
5484 && code
!= CEIL_MOD_EXPR
&& code
!= FLOOR_MOD_EXPR
)
5488 /* If it's a multiply or a division/modulus operation of a multiple
5489 of our constant, do the operation and verify it doesn't overflow. */
5490 if (code
== MULT_EXPR
5491 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
5493 op1
= const_binop (code
, fold_convert (ctype
, op1
),
5494 fold_convert (ctype
, c
), 0);
5495 /* We allow the constant to overflow with wrapping semantics. */
5497 || (TREE_OVERFLOW (op1
) && ! flag_wrapv
))
5503 /* If we have an unsigned type is not a sizetype, we cannot widen
5504 the operation since it will change the result if the original
5505 computation overflowed. */
5506 if (TYPE_UNSIGNED (ctype
)
5507 && ! (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
))
5511 /* If we were able to eliminate our operation from the first side,
5512 apply our operation to the second side and reform the PLUS. */
5513 if (t1
!= 0 && (TREE_CODE (t1
) != code
|| code
== MULT_EXPR
))
5514 return fold_build2 (tcode
, ctype
, fold_convert (ctype
, t1
), op1
);
5516 /* The last case is if we are a multiply. In that case, we can
5517 apply the distributive law to commute the multiply and addition
5518 if the multiplication of the constants doesn't overflow. */
5519 if (code
== MULT_EXPR
)
5520 return fold_build2 (tcode
, ctype
,
5521 fold_build2 (code
, ctype
,
5522 fold_convert (ctype
, op0
),
5523 fold_convert (ctype
, c
)),
5529 /* We have a special case here if we are doing something like
5530 (C * 8) % 4 since we know that's zero. */
5531 if ((code
== TRUNC_MOD_EXPR
|| code
== CEIL_MOD_EXPR
5532 || code
== FLOOR_MOD_EXPR
|| code
== ROUND_MOD_EXPR
)
5533 && TREE_CODE (TREE_OPERAND (t
, 1)) == INTEGER_CST
5534 && integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
5535 return omit_one_operand (type
, integer_zero_node
, op0
);
5537 /* ... fall through ... */
5539 case TRUNC_DIV_EXPR
: case CEIL_DIV_EXPR
: case FLOOR_DIV_EXPR
:
5540 case ROUND_DIV_EXPR
: case EXACT_DIV_EXPR
:
5541 /* If we can extract our operation from the LHS, do so and return a
5542 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5543 do something only if the second operand is a constant. */
5545 && (t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
5546 return fold_build2 (tcode
, ctype
, fold_convert (ctype
, t1
),
5547 fold_convert (ctype
, op1
));
5548 else if (tcode
== MULT_EXPR
&& code
== MULT_EXPR
5549 && (t1
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
5550 return fold_build2 (tcode
, ctype
, fold_convert (ctype
, op0
),
5551 fold_convert (ctype
, t1
));
5552 else if (TREE_CODE (op1
) != INTEGER_CST
)
5555 /* If these are the same operation types, we can associate them
5556 assuming no overflow. */
5558 && 0 != (t1
= const_binop (MULT_EXPR
, fold_convert (ctype
, op1
),
5559 fold_convert (ctype
, c
), 0))
5560 && ! TREE_OVERFLOW (t1
))
5561 return fold_build2 (tcode
, ctype
, fold_convert (ctype
, op0
), t1
);
5563 /* If these operations "cancel" each other, we have the main
5564 optimizations of this pass, which occur when either constant is a
5565 multiple of the other, in which case we replace this with either an
5566 operation or CODE or TCODE.
5568 If we have an unsigned type that is not a sizetype, we cannot do
5569 this since it will change the result if the original computation
5571 if ((! TYPE_UNSIGNED (ctype
)
5572 || (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
)))
5574 && ((code
== MULT_EXPR
&& tcode
== EXACT_DIV_EXPR
)
5575 || (tcode
== MULT_EXPR
5576 && code
!= TRUNC_MOD_EXPR
&& code
!= CEIL_MOD_EXPR
5577 && code
!= FLOOR_MOD_EXPR
&& code
!= ROUND_MOD_EXPR
)))
5579 if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
5580 return fold_build2 (tcode
, ctype
, fold_convert (ctype
, op0
),
5581 fold_convert (ctype
,
5582 const_binop (TRUNC_DIV_EXPR
,
5584 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, c
, op1
, 0)))
5585 return fold_build2 (code
, ctype
, fold_convert (ctype
, op0
),
5586 fold_convert (ctype
,
5587 const_binop (TRUNC_DIV_EXPR
,
5599 /* Return a node which has the indicated constant VALUE (either 0 or
5600 1), and is of the indicated TYPE. */
5603 constant_boolean_node (int value
, tree type
)
5605 if (type
== integer_type_node
)
5606 return value
? integer_one_node
: integer_zero_node
;
5607 else if (type
== boolean_type_node
)
5608 return value
? boolean_true_node
: boolean_false_node
;
5610 return build_int_cst (type
, value
);
5614 /* Return true if expr looks like an ARRAY_REF and set base and
5615 offset to the appropriate trees. If there is no offset,
5616 offset is set to NULL_TREE. Base will be canonicalized to
5617 something you can get the element type from using
5618 TREE_TYPE (TREE_TYPE (base)). Offset will be the offset
5619 in bytes to the base. */
5622 extract_array_ref (tree expr
, tree
*base
, tree
*offset
)
5624 /* One canonical form is a PLUS_EXPR with the first
5625 argument being an ADDR_EXPR with a possible NOP_EXPR
5627 if (TREE_CODE (expr
) == PLUS_EXPR
)
5629 tree op0
= TREE_OPERAND (expr
, 0);
5630 tree inner_base
, dummy1
;
5631 /* Strip NOP_EXPRs here because the C frontends and/or
5632 folders present us (int *)&x.a + 4B possibly. */
5634 if (extract_array_ref (op0
, &inner_base
, &dummy1
))
5637 if (dummy1
== NULL_TREE
)
5638 *offset
= TREE_OPERAND (expr
, 1);
5640 *offset
= fold_build2 (PLUS_EXPR
, TREE_TYPE (expr
),
5641 dummy1
, TREE_OPERAND (expr
, 1));
5645 /* Other canonical form is an ADDR_EXPR of an ARRAY_REF,
5646 which we transform into an ADDR_EXPR with appropriate
5647 offset. For other arguments to the ADDR_EXPR we assume
5648 zero offset and as such do not care about the ADDR_EXPR
5649 type and strip possible nops from it. */
5650 else if (TREE_CODE (expr
) == ADDR_EXPR
)
5652 tree op0
= TREE_OPERAND (expr
, 0);
5653 if (TREE_CODE (op0
) == ARRAY_REF
)
5655 tree idx
= TREE_OPERAND (op0
, 1);
5656 *base
= TREE_OPERAND (op0
, 0);
5657 *offset
= fold_build2 (MULT_EXPR
, TREE_TYPE (idx
), idx
,
5658 array_ref_element_size (op0
));
5662 /* Handle array-to-pointer decay as &a. */
5663 if (TREE_CODE (TREE_TYPE (op0
)) == ARRAY_TYPE
)
5664 *base
= TREE_OPERAND (expr
, 0);
5667 *offset
= NULL_TREE
;
5671 /* The next canonical form is a VAR_DECL with POINTER_TYPE. */
5672 else if (SSA_VAR_P (expr
)
5673 && TREE_CODE (TREE_TYPE (expr
)) == POINTER_TYPE
)
5676 *offset
= NULL_TREE
;
5684 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
5685 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
5686 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
5687 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
5688 COND is the first argument to CODE; otherwise (as in the example
5689 given here), it is the second argument. TYPE is the type of the
5690 original expression. Return NULL_TREE if no simplification is
5694 fold_binary_op_with_conditional_arg (enum tree_code code
,
5695 tree type
, tree op0
, tree op1
,
5696 tree cond
, tree arg
, int cond_first_p
)
5698 tree cond_type
= cond_first_p
? TREE_TYPE (op0
) : TREE_TYPE (op1
);
5699 tree arg_type
= cond_first_p
? TREE_TYPE (op1
) : TREE_TYPE (op0
);
5700 tree test
, true_value
, false_value
;
5701 tree lhs
= NULL_TREE
;
5702 tree rhs
= NULL_TREE
;
5704 /* This transformation is only worthwhile if we don't have to wrap
5705 arg in a SAVE_EXPR, and the operation can be simplified on at least
5706 one of the branches once its pushed inside the COND_EXPR. */
5707 if (!TREE_CONSTANT (arg
))
5710 if (TREE_CODE (cond
) == COND_EXPR
)
5712 test
= TREE_OPERAND (cond
, 0);
5713 true_value
= TREE_OPERAND (cond
, 1);
5714 false_value
= TREE_OPERAND (cond
, 2);
5715 /* If this operand throws an expression, then it does not make
5716 sense to try to perform a logical or arithmetic operation
5718 if (VOID_TYPE_P (TREE_TYPE (true_value
)))
5720 if (VOID_TYPE_P (TREE_TYPE (false_value
)))
5725 tree testtype
= TREE_TYPE (cond
);
5727 true_value
= constant_boolean_node (true, testtype
);
5728 false_value
= constant_boolean_node (false, testtype
);
5731 arg
= fold_convert (arg_type
, arg
);
5734 true_value
= fold_convert (cond_type
, true_value
);
5736 lhs
= fold_build2 (code
, type
, true_value
, arg
);
5738 lhs
= fold_build2 (code
, type
, arg
, true_value
);
5742 false_value
= fold_convert (cond_type
, false_value
);
5744 rhs
= fold_build2 (code
, type
, false_value
, arg
);
5746 rhs
= fold_build2 (code
, type
, arg
, false_value
);
5749 test
= fold_build3 (COND_EXPR
, type
, test
, lhs
, rhs
);
5750 return fold_convert (type
, test
);
5754 /* Subroutine of fold() that checks for the addition of +/- 0.0.
5756 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
5757 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
5758 ADDEND is the same as X.
5760 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
5761 and finite. The problematic cases are when X is zero, and its mode
5762 has signed zeros. In the case of rounding towards -infinity,
5763 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
5764 modes, X + 0 is not the same as X because -0 + 0 is 0. */
5767 fold_real_zero_addition_p (tree type
, tree addend
, int negate
)
5769 if (!real_zerop (addend
))
5772 /* Don't allow the fold with -fsignaling-nans. */
5773 if (HONOR_SNANS (TYPE_MODE (type
)))
5776 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
5777 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type
)))
5780 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
5781 if (TREE_CODE (addend
) == REAL_CST
5782 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend
)))
5785 /* The mode has signed zeros, and we have to honor their sign.
5786 In this situation, there is only one case we can return true for.
5787 X - 0 is the same as X unless rounding towards -infinity is
5789 return negate
&& !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type
));
5792 /* Subroutine of fold() that checks comparisons of built-in math
5793 functions against real constants.
5795 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
5796 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
5797 is the type of the result and ARG0 and ARG1 are the operands of the
5798 comparison. ARG1 must be a TREE_REAL_CST.
5800 The function returns the constant folded tree if a simplification
5801 can be made, and NULL_TREE otherwise. */
5804 fold_mathfn_compare (enum built_in_function fcode
, enum tree_code code
,
5805 tree type
, tree arg0
, tree arg1
)
5809 if (BUILTIN_SQRT_P (fcode
))
5811 tree arg
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
5812 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (arg0
));
5814 c
= TREE_REAL_CST (arg1
);
5815 if (REAL_VALUE_NEGATIVE (c
))
5817 /* sqrt(x) < y is always false, if y is negative. */
5818 if (code
== EQ_EXPR
|| code
== LT_EXPR
|| code
== LE_EXPR
)
5819 return omit_one_operand (type
, integer_zero_node
, arg
);
5821 /* sqrt(x) > y is always true, if y is negative and we
5822 don't care about NaNs, i.e. negative values of x. */
5823 if (code
== NE_EXPR
|| !HONOR_NANS (mode
))
5824 return omit_one_operand (type
, integer_one_node
, arg
);
5826 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
5827 return fold_build2 (GE_EXPR
, type
, arg
,
5828 build_real (TREE_TYPE (arg
), dconst0
));
5830 else if (code
== GT_EXPR
|| code
== GE_EXPR
)
5834 REAL_ARITHMETIC (c2
, MULT_EXPR
, c
, c
);
5835 real_convert (&c2
, mode
, &c2
);
5837 if (REAL_VALUE_ISINF (c2
))
5839 /* sqrt(x) > y is x == +Inf, when y is very large. */
5840 if (HONOR_INFINITIES (mode
))
5841 return fold_build2 (EQ_EXPR
, type
, arg
,
5842 build_real (TREE_TYPE (arg
), c2
));
5844 /* sqrt(x) > y is always false, when y is very large
5845 and we don't care about infinities. */
5846 return omit_one_operand (type
, integer_zero_node
, arg
);
5849 /* sqrt(x) > c is the same as x > c*c. */
5850 return fold_build2 (code
, type
, arg
,
5851 build_real (TREE_TYPE (arg
), c2
));
5853 else if (code
== LT_EXPR
|| code
== LE_EXPR
)
5857 REAL_ARITHMETIC (c2
, MULT_EXPR
, c
, c
);
5858 real_convert (&c2
, mode
, &c2
);
5860 if (REAL_VALUE_ISINF (c2
))
5862 /* sqrt(x) < y is always true, when y is a very large
5863 value and we don't care about NaNs or Infinities. */
5864 if (! HONOR_NANS (mode
) && ! HONOR_INFINITIES (mode
))
5865 return omit_one_operand (type
, integer_one_node
, arg
);
5867 /* sqrt(x) < y is x != +Inf when y is very large and we
5868 don't care about NaNs. */
5869 if (! HONOR_NANS (mode
))
5870 return fold_build2 (NE_EXPR
, type
, arg
,
5871 build_real (TREE_TYPE (arg
), c2
));
5873 /* sqrt(x) < y is x >= 0 when y is very large and we
5874 don't care about Infinities. */
5875 if (! HONOR_INFINITIES (mode
))
5876 return fold_build2 (GE_EXPR
, type
, arg
,
5877 build_real (TREE_TYPE (arg
), dconst0
));
5879 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
5880 if (lang_hooks
.decls
.global_bindings_p () != 0
5881 || CONTAINS_PLACEHOLDER_P (arg
))
5884 arg
= save_expr (arg
);
5885 return fold_build2 (TRUTH_ANDIF_EXPR
, type
,
5886 fold_build2 (GE_EXPR
, type
, arg
,
5887 build_real (TREE_TYPE (arg
),
5889 fold_build2 (NE_EXPR
, type
, arg
,
5890 build_real (TREE_TYPE (arg
),
5894 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
5895 if (! HONOR_NANS (mode
))
5896 return fold_build2 (code
, type
, arg
,
5897 build_real (TREE_TYPE (arg
), c2
));
5899 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
5900 if (lang_hooks
.decls
.global_bindings_p () == 0
5901 && ! CONTAINS_PLACEHOLDER_P (arg
))
5903 arg
= save_expr (arg
);
5904 return fold_build2 (TRUTH_ANDIF_EXPR
, type
,
5905 fold_build2 (GE_EXPR
, type
, arg
,
5906 build_real (TREE_TYPE (arg
),
5908 fold_build2 (code
, type
, arg
,
5909 build_real (TREE_TYPE (arg
),
5918 /* Subroutine of fold() that optimizes comparisons against Infinities,
5919 either +Inf or -Inf.
5921 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5922 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5923 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5925 The function returns the constant folded tree if a simplification
5926 can be made, and NULL_TREE otherwise. */
5929 fold_inf_compare (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
5931 enum machine_mode mode
;
5932 REAL_VALUE_TYPE max
;
5936 mode
= TYPE_MODE (TREE_TYPE (arg0
));
5938 /* For negative infinity swap the sense of the comparison. */
5939 neg
= REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1
));
5941 code
= swap_tree_comparison (code
);
5946 /* x > +Inf is always false, if with ignore sNANs. */
5947 if (HONOR_SNANS (mode
))
5949 return omit_one_operand (type
, integer_zero_node
, arg0
);
5952 /* x <= +Inf is always true, if we don't case about NaNs. */
5953 if (! HONOR_NANS (mode
))
5954 return omit_one_operand (type
, integer_one_node
, arg0
);
5956 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
5957 if (lang_hooks
.decls
.global_bindings_p () == 0
5958 && ! CONTAINS_PLACEHOLDER_P (arg0
))
5960 arg0
= save_expr (arg0
);
5961 return fold_build2 (EQ_EXPR
, type
, arg0
, arg0
);
5967 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
5968 real_maxval (&max
, neg
, mode
);
5969 return fold_build2 (neg
? LT_EXPR
: GT_EXPR
, type
,
5970 arg0
, build_real (TREE_TYPE (arg0
), max
));
5973 /* x < +Inf is always equal to x <= DBL_MAX. */
5974 real_maxval (&max
, neg
, mode
);
5975 return fold_build2 (neg
? GE_EXPR
: LE_EXPR
, type
,
5976 arg0
, build_real (TREE_TYPE (arg0
), max
));
5979 /* x != +Inf is always equal to !(x > DBL_MAX). */
5980 real_maxval (&max
, neg
, mode
);
5981 if (! HONOR_NANS (mode
))
5982 return fold_build2 (neg
? GE_EXPR
: LE_EXPR
, type
,
5983 arg0
, build_real (TREE_TYPE (arg0
), max
));
5985 /* The transformation below creates non-gimple code and thus is
5986 not appropriate if we are in gimple form. */
5990 temp
= fold_build2 (neg
? LT_EXPR
: GT_EXPR
, type
,
5991 arg0
, build_real (TREE_TYPE (arg0
), max
));
5992 return fold_build1 (TRUTH_NOT_EXPR
, type
, temp
);
6001 /* Subroutine of fold() that optimizes comparisons of a division by
6002 a nonzero integer constant against an integer constant, i.e.
6005 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6006 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6007 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6009 The function returns the constant folded tree if a simplification
6010 can be made, and NULL_TREE otherwise. */
6013 fold_div_compare (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
6015 tree prod
, tmp
, hi
, lo
;
6016 tree arg00
= TREE_OPERAND (arg0
, 0);
6017 tree arg01
= TREE_OPERAND (arg0
, 1);
6018 unsigned HOST_WIDE_INT lpart
;
6019 HOST_WIDE_INT hpart
;
6022 /* We have to do this the hard way to detect unsigned overflow.
6023 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
6024 overflow
= mul_double (TREE_INT_CST_LOW (arg01
),
6025 TREE_INT_CST_HIGH (arg01
),
6026 TREE_INT_CST_LOW (arg1
),
6027 TREE_INT_CST_HIGH (arg1
), &lpart
, &hpart
);
6028 prod
= build_int_cst_wide (TREE_TYPE (arg00
), lpart
, hpart
);
6029 prod
= force_fit_type (prod
, -1, overflow
, false);
6031 if (TYPE_UNSIGNED (TREE_TYPE (arg0
)))
6033 tmp
= int_const_binop (MINUS_EXPR
, arg01
, integer_one_node
, 0);
6036 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
6037 overflow
= add_double (TREE_INT_CST_LOW (prod
),
6038 TREE_INT_CST_HIGH (prod
),
6039 TREE_INT_CST_LOW (tmp
),
6040 TREE_INT_CST_HIGH (tmp
),
6042 hi
= build_int_cst_wide (TREE_TYPE (arg00
), lpart
, hpart
);
6043 hi
= force_fit_type (hi
, -1, overflow
| TREE_OVERFLOW (prod
),
6044 TREE_CONSTANT_OVERFLOW (prod
));
6046 else if (tree_int_cst_sgn (arg01
) >= 0)
6048 tmp
= int_const_binop (MINUS_EXPR
, arg01
, integer_one_node
, 0);
6049 switch (tree_int_cst_sgn (arg1
))
6052 lo
= int_const_binop (MINUS_EXPR
, prod
, tmp
, 0);
6057 lo
= fold_negate_const (tmp
, TREE_TYPE (arg0
));
6062 hi
= int_const_binop (PLUS_EXPR
, prod
, tmp
, 0);
6072 /* A negative divisor reverses the relational operators. */
6073 code
= swap_tree_comparison (code
);
6075 tmp
= int_const_binop (PLUS_EXPR
, arg01
, integer_one_node
, 0);
6076 switch (tree_int_cst_sgn (arg1
))
6079 hi
= int_const_binop (MINUS_EXPR
, prod
, tmp
, 0);
6084 hi
= fold_negate_const (tmp
, TREE_TYPE (arg0
));
6089 lo
= int_const_binop (PLUS_EXPR
, prod
, tmp
, 0);
6101 if (TREE_OVERFLOW (lo
) && TREE_OVERFLOW (hi
))
6102 return omit_one_operand (type
, integer_zero_node
, arg00
);
6103 if (TREE_OVERFLOW (hi
))
6104 return fold_build2 (GE_EXPR
, type
, arg00
, lo
);
6105 if (TREE_OVERFLOW (lo
))
6106 return fold_build2 (LE_EXPR
, type
, arg00
, hi
);
6107 return build_range_check (type
, arg00
, 1, lo
, hi
);
6110 if (TREE_OVERFLOW (lo
) && TREE_OVERFLOW (hi
))
6111 return omit_one_operand (type
, integer_one_node
, arg00
);
6112 if (TREE_OVERFLOW (hi
))
6113 return fold_build2 (LT_EXPR
, type
, arg00
, lo
);
6114 if (TREE_OVERFLOW (lo
))
6115 return fold_build2 (GT_EXPR
, type
, arg00
, hi
);
6116 return build_range_check (type
, arg00
, 0, lo
, hi
);
6119 if (TREE_OVERFLOW (lo
))
6120 return omit_one_operand (type
, integer_zero_node
, arg00
);
6121 return fold_build2 (LT_EXPR
, type
, arg00
, lo
);
6124 if (TREE_OVERFLOW (hi
))
6125 return omit_one_operand (type
, integer_one_node
, arg00
);
6126 return fold_build2 (LE_EXPR
, type
, arg00
, hi
);
6129 if (TREE_OVERFLOW (hi
))
6130 return omit_one_operand (type
, integer_zero_node
, arg00
);
6131 return fold_build2 (GT_EXPR
, type
, arg00
, hi
);
6134 if (TREE_OVERFLOW (lo
))
6135 return omit_one_operand (type
, integer_one_node
, arg00
);
6136 return fold_build2 (GE_EXPR
, type
, arg00
, lo
);
6146 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6147 equality/inequality test, then return a simplified form of the test
6148 using a sign testing. Otherwise return NULL. TYPE is the desired
6152 fold_single_bit_test_into_sign_test (enum tree_code code
, tree arg0
, tree arg1
,
6155 /* If this is testing a single bit, we can optimize the test. */
6156 if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
6157 && TREE_CODE (arg0
) == BIT_AND_EXPR
&& integer_zerop (arg1
)
6158 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
6160 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6161 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6162 tree arg00
= sign_bit_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg0
, 1));
6164 if (arg00
!= NULL_TREE
6165 /* This is only a win if casting to a signed type is cheap,
6166 i.e. when arg00's type is not a partial mode. */
6167 && TYPE_PRECISION (TREE_TYPE (arg00
))
6168 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00
))))
6170 tree stype
= lang_hooks
.types
.signed_type (TREE_TYPE (arg00
));
6171 return fold_build2 (code
== EQ_EXPR
? GE_EXPR
: LT_EXPR
,
6172 result_type
, fold_convert (stype
, arg00
),
6173 build_int_cst (stype
, 0));
6180 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6181 equality/inequality test, then return a simplified form of
6182 the test using shifts and logical operations. Otherwise return
6183 NULL. TYPE is the desired result type. */
6186 fold_single_bit_test (enum tree_code code
, tree arg0
, tree arg1
,
6189 /* If this is testing a single bit, we can optimize the test. */
6190 if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
6191 && TREE_CODE (arg0
) == BIT_AND_EXPR
&& integer_zerop (arg1
)
6192 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
6194 tree inner
= TREE_OPERAND (arg0
, 0);
6195 tree type
= TREE_TYPE (arg0
);
6196 int bitnum
= tree_log2 (TREE_OPERAND (arg0
, 1));
6197 enum machine_mode operand_mode
= TYPE_MODE (type
);
6199 tree signed_type
, unsigned_type
, intermediate_type
;
6202 /* First, see if we can fold the single bit test into a sign-bit
6204 tem
= fold_single_bit_test_into_sign_test (code
, arg0
, arg1
,
6209 /* Otherwise we have (A & C) != 0 where C is a single bit,
6210 convert that into ((A >> C2) & 1). Where C2 = log2(C).
6211 Similarly for (A & C) == 0. */
6213 /* If INNER is a right shift of a constant and it plus BITNUM does
6214 not overflow, adjust BITNUM and INNER. */
6215 if (TREE_CODE (inner
) == RSHIFT_EXPR
6216 && TREE_CODE (TREE_OPERAND (inner
, 1)) == INTEGER_CST
6217 && TREE_INT_CST_HIGH (TREE_OPERAND (inner
, 1)) == 0
6218 && bitnum
< TYPE_PRECISION (type
)
6219 && 0 > compare_tree_int (TREE_OPERAND (inner
, 1),
6220 bitnum
- TYPE_PRECISION (type
)))
6222 bitnum
+= TREE_INT_CST_LOW (TREE_OPERAND (inner
, 1));
6223 inner
= TREE_OPERAND (inner
, 0);
6226 /* If we are going to be able to omit the AND below, we must do our
6227 operations as unsigned. If we must use the AND, we have a choice.
6228 Normally unsigned is faster, but for some machines signed is. */
6229 #ifdef LOAD_EXTEND_OP
6230 ops_unsigned
= (LOAD_EXTEND_OP (operand_mode
) == SIGN_EXTEND
6231 && !flag_syntax_only
) ? 0 : 1;
6236 signed_type
= lang_hooks
.types
.type_for_mode (operand_mode
, 0);
6237 unsigned_type
= lang_hooks
.types
.type_for_mode (operand_mode
, 1);
6238 intermediate_type
= ops_unsigned
? unsigned_type
: signed_type
;
6239 inner
= fold_convert (intermediate_type
, inner
);
6242 inner
= build2 (RSHIFT_EXPR
, intermediate_type
,
6243 inner
, size_int (bitnum
));
6245 if (code
== EQ_EXPR
)
6246 inner
= fold_build2 (BIT_XOR_EXPR
, intermediate_type
,
6247 inner
, integer_one_node
);
6249 /* Put the AND last so it can combine with more things. */
6250 inner
= build2 (BIT_AND_EXPR
, intermediate_type
,
6251 inner
, integer_one_node
);
6253 /* Make sure to return the proper type. */
6254 inner
= fold_convert (result_type
, inner
);
6261 /* Check whether we are allowed to reorder operands arg0 and arg1,
6262 such that the evaluation of arg1 occurs before arg0. */
6265 reorder_operands_p (tree arg0
, tree arg1
)
6267 if (! flag_evaluation_order
)
6269 if (TREE_CONSTANT (arg0
) || TREE_CONSTANT (arg1
))
6271 return ! TREE_SIDE_EFFECTS (arg0
)
6272 && ! TREE_SIDE_EFFECTS (arg1
);
6275 /* Test whether it is preferable two swap two operands, ARG0 and
6276 ARG1, for example because ARG0 is an integer constant and ARG1
6277 isn't. If REORDER is true, only recommend swapping if we can
6278 evaluate the operands in reverse order. */
6281 tree_swap_operands_p (tree arg0
, tree arg1
, bool reorder
)
6283 STRIP_SIGN_NOPS (arg0
);
6284 STRIP_SIGN_NOPS (arg1
);
6286 if (TREE_CODE (arg1
) == INTEGER_CST
)
6288 if (TREE_CODE (arg0
) == INTEGER_CST
)
6291 if (TREE_CODE (arg1
) == REAL_CST
)
6293 if (TREE_CODE (arg0
) == REAL_CST
)
6296 if (TREE_CODE (arg1
) == COMPLEX_CST
)
6298 if (TREE_CODE (arg0
) == COMPLEX_CST
)
6301 if (TREE_CONSTANT (arg1
))
6303 if (TREE_CONSTANT (arg0
))
6309 if (reorder
&& flag_evaluation_order
6310 && (TREE_SIDE_EFFECTS (arg0
) || TREE_SIDE_EFFECTS (arg1
)))
6318 /* It is preferable to swap two SSA_NAME to ensure a canonical form
6319 for commutative and comparison operators. Ensuring a canonical
6320 form allows the optimizers to find additional redundancies without
6321 having to explicitly check for both orderings. */
6322 if (TREE_CODE (arg0
) == SSA_NAME
6323 && TREE_CODE (arg1
) == SSA_NAME
6324 && SSA_NAME_VERSION (arg0
) > SSA_NAME_VERSION (arg1
))
6330 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
6331 ARG0 is extended to a wider type. */
6334 fold_widened_comparison (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
6336 tree arg0_unw
= get_unwidened (arg0
, NULL_TREE
);
6338 tree shorter_type
, outer_type
;
6342 if (arg0_unw
== arg0
)
6344 shorter_type
= TREE_TYPE (arg0_unw
);
6346 #ifdef HAVE_canonicalize_funcptr_for_compare
6347 /* Disable this optimization if we're casting a function pointer
6348 type on targets that require function pointer canonicalization. */
6349 if (HAVE_canonicalize_funcptr_for_compare
6350 && TREE_CODE (shorter_type
) == POINTER_TYPE
6351 && TREE_CODE (TREE_TYPE (shorter_type
)) == FUNCTION_TYPE
)
6355 if (TYPE_PRECISION (TREE_TYPE (arg0
)) <= TYPE_PRECISION (shorter_type
))
6358 arg1_unw
= get_unwidened (arg1
, shorter_type
);
6360 /* If possible, express the comparison in the shorter mode. */
6361 if ((code
== EQ_EXPR
|| code
== NE_EXPR
6362 || TYPE_UNSIGNED (TREE_TYPE (arg0
)) == TYPE_UNSIGNED (shorter_type
))
6363 && (TREE_TYPE (arg1_unw
) == shorter_type
6364 || (TREE_CODE (arg1_unw
) == INTEGER_CST
6365 && (TREE_CODE (shorter_type
) == INTEGER_TYPE
6366 || TREE_CODE (shorter_type
) == BOOLEAN_TYPE
)
6367 && int_fits_type_p (arg1_unw
, shorter_type
))))
6368 return fold_build2 (code
, type
, arg0_unw
,
6369 fold_convert (shorter_type
, arg1_unw
));
6371 if (TREE_CODE (arg1_unw
) != INTEGER_CST
6372 || TREE_CODE (shorter_type
) != INTEGER_TYPE
6373 || !int_fits_type_p (arg1_unw
, shorter_type
))
6376 /* If we are comparing with the integer that does not fit into the range
6377 of the shorter type, the result is known. */
6378 outer_type
= TREE_TYPE (arg1_unw
);
6379 min
= lower_bound_in_type (outer_type
, shorter_type
);
6380 max
= upper_bound_in_type (outer_type
, shorter_type
);
6382 above
= integer_nonzerop (fold_relational_const (LT_EXPR
, type
,
6384 below
= integer_nonzerop (fold_relational_const (LT_EXPR
, type
,
6391 return omit_one_operand (type
, integer_zero_node
, arg0
);
6396 return omit_one_operand (type
, integer_one_node
, arg0
);
6402 return omit_one_operand (type
, integer_one_node
, arg0
);
6404 return omit_one_operand (type
, integer_zero_node
, arg0
);
6409 return omit_one_operand (type
, integer_zero_node
, arg0
);
6411 return omit_one_operand (type
, integer_one_node
, arg0
);
6420 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
6421 ARG0 just the signedness is changed. */
6424 fold_sign_changed_comparison (enum tree_code code
, tree type
,
6425 tree arg0
, tree arg1
)
6427 tree arg0_inner
, tmp
;
6428 tree inner_type
, outer_type
;
6430 if (TREE_CODE (arg0
) != NOP_EXPR
6431 && TREE_CODE (arg0
) != CONVERT_EXPR
)
6434 outer_type
= TREE_TYPE (arg0
);
6435 arg0_inner
= TREE_OPERAND (arg0
, 0);
6436 inner_type
= TREE_TYPE (arg0_inner
);
6438 #ifdef HAVE_canonicalize_funcptr_for_compare
6439 /* Disable this optimization if we're casting a function pointer
6440 type on targets that require function pointer canonicalization. */
6441 if (HAVE_canonicalize_funcptr_for_compare
6442 && TREE_CODE (inner_type
) == POINTER_TYPE
6443 && TREE_CODE (TREE_TYPE (inner_type
)) == FUNCTION_TYPE
)
6447 if (TYPE_PRECISION (inner_type
) != TYPE_PRECISION (outer_type
))
6450 if (TREE_CODE (arg1
) != INTEGER_CST
6451 && !((TREE_CODE (arg1
) == NOP_EXPR
6452 || TREE_CODE (arg1
) == CONVERT_EXPR
)
6453 && TREE_TYPE (TREE_OPERAND (arg1
, 0)) == inner_type
))
6456 if (TYPE_UNSIGNED (inner_type
) != TYPE_UNSIGNED (outer_type
)
6461 if (TREE_CODE (arg1
) == INTEGER_CST
)
6463 tmp
= build_int_cst_wide (inner_type
,
6464 TREE_INT_CST_LOW (arg1
),
6465 TREE_INT_CST_HIGH (arg1
));
6466 arg1
= force_fit_type (tmp
, 0,
6467 TREE_OVERFLOW (arg1
),
6468 TREE_CONSTANT_OVERFLOW (arg1
));
6471 arg1
= fold_convert (inner_type
, arg1
);
6473 return fold_build2 (code
, type
, arg0_inner
, arg1
);
6476 /* Tries to replace &a[idx] CODE s * delta with &a[idx CODE delta], if s is
6477 step of the array. Reconstructs s and delta in the case of s * delta
6478 being an integer constant (and thus already folded).
6479 ADDR is the address. MULT is the multiplicative expression.
6480 If the function succeeds, the new address expression is returned. Otherwise
6481 NULL_TREE is returned. */
6484 try_move_mult_to_index (enum tree_code code
, tree addr
, tree op1
)
6486 tree s
, delta
, step
;
6487 tree ref
= TREE_OPERAND (addr
, 0), pref
;
6491 /* Canonicalize op1 into a possibly non-constant delta
6492 and an INTEGER_CST s. */
6493 if (TREE_CODE (op1
) == MULT_EXPR
)
6495 tree arg0
= TREE_OPERAND (op1
, 0), arg1
= TREE_OPERAND (op1
, 1);
6500 if (TREE_CODE (arg0
) == INTEGER_CST
)
6505 else if (TREE_CODE (arg1
) == INTEGER_CST
)
6513 else if (TREE_CODE (op1
) == INTEGER_CST
)
6520 /* Simulate we are delta * 1. */
6522 s
= integer_one_node
;
6525 for (;; ref
= TREE_OPERAND (ref
, 0))
6527 if (TREE_CODE (ref
) == ARRAY_REF
)
6529 itype
= TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref
, 0)));
6533 step
= array_ref_element_size (ref
);
6534 if (TREE_CODE (step
) != INTEGER_CST
)
6539 if (! tree_int_cst_equal (step
, s
))
6544 /* Try if delta is a multiple of step. */
6545 tree tmp
= div_if_zero_remainder (EXACT_DIV_EXPR
, delta
, step
);
6554 if (!handled_component_p (ref
))
6558 /* We found the suitable array reference. So copy everything up to it,
6559 and replace the index. */
6561 pref
= TREE_OPERAND (addr
, 0);
6562 ret
= copy_node (pref
);
6567 pref
= TREE_OPERAND (pref
, 0);
6568 TREE_OPERAND (pos
, 0) = copy_node (pref
);
6569 pos
= TREE_OPERAND (pos
, 0);
6572 TREE_OPERAND (pos
, 1) = fold_build2 (code
, itype
,
6573 fold_convert (itype
,
6574 TREE_OPERAND (pos
, 1)),
6575 fold_convert (itype
, delta
));
6577 return fold_build1 (ADDR_EXPR
, TREE_TYPE (addr
), ret
);
6581 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
6582 means A >= Y && A != MAX, but in this case we know that
6583 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
6586 fold_to_nonsharp_ineq_using_bound (tree ineq
, tree bound
)
6588 tree a
, typea
, type
= TREE_TYPE (ineq
), a1
, diff
, y
;
6590 if (TREE_CODE (bound
) == LT_EXPR
)
6591 a
= TREE_OPERAND (bound
, 0);
6592 else if (TREE_CODE (bound
) == GT_EXPR
)
6593 a
= TREE_OPERAND (bound
, 1);
6597 typea
= TREE_TYPE (a
);
6598 if (!INTEGRAL_TYPE_P (typea
)
6599 && !POINTER_TYPE_P (typea
))
6602 if (TREE_CODE (ineq
) == LT_EXPR
)
6604 a1
= TREE_OPERAND (ineq
, 1);
6605 y
= TREE_OPERAND (ineq
, 0);
6607 else if (TREE_CODE (ineq
) == GT_EXPR
)
6609 a1
= TREE_OPERAND (ineq
, 0);
6610 y
= TREE_OPERAND (ineq
, 1);
6615 if (TREE_TYPE (a1
) != typea
)
6618 diff
= fold_build2 (MINUS_EXPR
, typea
, a1
, a
);
6619 if (!integer_onep (diff
))
6622 return fold_build2 (GE_EXPR
, type
, a
, y
);
6625 /* Fold a sum or difference of at least one multiplication.
6626 Returns the folded tree or NULL if no simplification could be made. */
6629 fold_plusminus_mult_expr (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
6631 tree arg00
, arg01
, arg10
, arg11
;
6632 tree alt0
= NULL_TREE
, alt1
= NULL_TREE
, same
;
6634 /* (A * C) +- (B * C) -> (A+-B) * C.
6635 (A * C) +- A -> A * (C+-1).
6636 We are most concerned about the case where C is a constant,
6637 but other combinations show up during loop reduction. Since
6638 it is not difficult, try all four possibilities. */
6640 if (TREE_CODE (arg0
) == MULT_EXPR
)
6642 arg00
= TREE_OPERAND (arg0
, 0);
6643 arg01
= TREE_OPERAND (arg0
, 1);
6648 if (!FLOAT_TYPE_P (type
))
6649 arg01
= build_int_cst (type
, 1);
6651 arg01
= build_real (type
, dconst1
);
6653 if (TREE_CODE (arg1
) == MULT_EXPR
)
6655 arg10
= TREE_OPERAND (arg1
, 0);
6656 arg11
= TREE_OPERAND (arg1
, 1);
6661 if (!FLOAT_TYPE_P (type
))
6662 arg11
= build_int_cst (type
, 1);
6664 arg11
= build_real (type
, dconst1
);
6668 if (operand_equal_p (arg01
, arg11
, 0))
6669 same
= arg01
, alt0
= arg00
, alt1
= arg10
;
6670 else if (operand_equal_p (arg00
, arg10
, 0))
6671 same
= arg00
, alt0
= arg01
, alt1
= arg11
;
6672 else if (operand_equal_p (arg00
, arg11
, 0))
6673 same
= arg00
, alt0
= arg01
, alt1
= arg10
;
6674 else if (operand_equal_p (arg01
, arg10
, 0))
6675 same
= arg01
, alt0
= arg00
, alt1
= arg11
;
6677 /* No identical multiplicands; see if we can find a common
6678 power-of-two factor in non-power-of-two multiplies. This
6679 can help in multi-dimensional array access. */
6680 else if (host_integerp (arg01
, 0)
6681 && host_integerp (arg11
, 0))
6683 HOST_WIDE_INT int01
, int11
, tmp
;
6686 int01
= TREE_INT_CST_LOW (arg01
);
6687 int11
= TREE_INT_CST_LOW (arg11
);
6689 /* Move min of absolute values to int11. */
6690 if ((int01
>= 0 ? int01
: -int01
)
6691 < (int11
>= 0 ? int11
: -int11
))
6693 tmp
= int01
, int01
= int11
, int11
= tmp
;
6694 alt0
= arg00
, arg00
= arg10
, arg10
= alt0
;
6701 if (exact_log2 (int11
) > 0 && int01
% int11
== 0)
6703 alt0
= fold_build2 (MULT_EXPR
, TREE_TYPE (arg00
), arg00
,
6704 build_int_cst (TREE_TYPE (arg00
),
6709 maybe_same
= alt0
, alt0
= alt1
, alt1
= maybe_same
;
6714 return fold_build2 (MULT_EXPR
, type
,
6715 fold_build2 (code
, type
,
6716 fold_convert (type
, alt0
),
6717 fold_convert (type
, alt1
)),
6718 fold_convert (type
, same
));
6723 /* Fold a unary expression of code CODE and type TYPE with operand
6724 OP0. Return the folded expression if folding is successful.
6725 Otherwise, return NULL_TREE. */
6728 fold_unary (enum tree_code code
, tree type
, tree op0
)
6732 enum tree_code_class kind
= TREE_CODE_CLASS (code
);
6734 gcc_assert (IS_EXPR_CODE_CLASS (kind
)
6735 && TREE_CODE_LENGTH (code
) == 1);
6740 if (code
== NOP_EXPR
|| code
== CONVERT_EXPR
6741 || code
== FLOAT_EXPR
|| code
== ABS_EXPR
)
6743 /* Don't use STRIP_NOPS, because signedness of argument type
6745 STRIP_SIGN_NOPS (arg0
);
6749 /* Strip any conversions that don't change the mode. This
6750 is safe for every expression, except for a comparison
6751 expression because its signedness is derived from its
6754 Note that this is done as an internal manipulation within
6755 the constant folder, in order to find the simplest
6756 representation of the arguments so that their form can be
6757 studied. In any cases, the appropriate type conversions
6758 should be put back in the tree that will get out of the
6764 if (TREE_CODE_CLASS (code
) == tcc_unary
)
6766 if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
6767 return build2 (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
6768 fold_build1 (code
, type
, TREE_OPERAND (arg0
, 1)));
6769 else if (TREE_CODE (arg0
) == COND_EXPR
)
6771 tree arg01
= TREE_OPERAND (arg0
, 1);
6772 tree arg02
= TREE_OPERAND (arg0
, 2);
6773 if (! VOID_TYPE_P (TREE_TYPE (arg01
)))
6774 arg01
= fold_build1 (code
, type
, arg01
);
6775 if (! VOID_TYPE_P (TREE_TYPE (arg02
)))
6776 arg02
= fold_build1 (code
, type
, arg02
);
6777 tem
= fold_build3 (COND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
6780 /* If this was a conversion, and all we did was to move into
6781 inside the COND_EXPR, bring it back out. But leave it if
6782 it is a conversion from integer to integer and the
6783 result precision is no wider than a word since such a
6784 conversion is cheap and may be optimized away by combine,
6785 while it couldn't if it were outside the COND_EXPR. Then return
6786 so we don't get into an infinite recursion loop taking the
6787 conversion out and then back in. */
6789 if ((code
== NOP_EXPR
|| code
== CONVERT_EXPR
6790 || code
== NON_LVALUE_EXPR
)
6791 && TREE_CODE (tem
) == COND_EXPR
6792 && TREE_CODE (TREE_OPERAND (tem
, 1)) == code
6793 && TREE_CODE (TREE_OPERAND (tem
, 2)) == code
6794 && ! VOID_TYPE_P (TREE_OPERAND (tem
, 1))
6795 && ! VOID_TYPE_P (TREE_OPERAND (tem
, 2))
6796 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem
, 1), 0))
6797 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem
, 2), 0)))
6798 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem
))
6800 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem
, 1), 0))))
6801 && TYPE_PRECISION (TREE_TYPE (tem
)) <= BITS_PER_WORD
)
6802 || flag_syntax_only
))
6803 tem
= build1 (code
, type
,
6805 TREE_TYPE (TREE_OPERAND
6806 (TREE_OPERAND (tem
, 1), 0)),
6807 TREE_OPERAND (tem
, 0),
6808 TREE_OPERAND (TREE_OPERAND (tem
, 1), 0),
6809 TREE_OPERAND (TREE_OPERAND (tem
, 2), 0)));
6812 else if (COMPARISON_CLASS_P (arg0
))
6814 if (TREE_CODE (type
) == BOOLEAN_TYPE
)
6816 arg0
= copy_node (arg0
);
6817 TREE_TYPE (arg0
) = type
;
6820 else if (TREE_CODE (type
) != INTEGER_TYPE
)
6821 return fold_build3 (COND_EXPR
, type
, arg0
,
6822 fold_build1 (code
, type
,
6824 fold_build1 (code
, type
,
6825 integer_zero_node
));
6834 case FIX_TRUNC_EXPR
:
6836 case FIX_FLOOR_EXPR
:
6837 case FIX_ROUND_EXPR
:
6838 if (TREE_TYPE (op0
) == type
)
6841 /* If we have (type) (a CMP b) and type is an integral type, return
6842 new expression involving the new type. */
6843 if (COMPARISON_CLASS_P (op0
) && INTEGRAL_TYPE_P (type
))
6844 return fold_build2 (TREE_CODE (op0
), type
, TREE_OPERAND (op0
, 0),
6845 TREE_OPERAND (op0
, 1));
6847 /* Handle cases of two conversions in a row. */
6848 if (TREE_CODE (op0
) == NOP_EXPR
6849 || TREE_CODE (op0
) == CONVERT_EXPR
)
6851 tree inside_type
= TREE_TYPE (TREE_OPERAND (op0
, 0));
6852 tree inter_type
= TREE_TYPE (op0
);
6853 int inside_int
= INTEGRAL_TYPE_P (inside_type
);
6854 int inside_ptr
= POINTER_TYPE_P (inside_type
);
6855 int inside_float
= FLOAT_TYPE_P (inside_type
);
6856 int inside_vec
= TREE_CODE (inside_type
) == VECTOR_TYPE
;
6857 unsigned int inside_prec
= TYPE_PRECISION (inside_type
);
6858 int inside_unsignedp
= TYPE_UNSIGNED (inside_type
);
6859 int inter_int
= INTEGRAL_TYPE_P (inter_type
);
6860 int inter_ptr
= POINTER_TYPE_P (inter_type
);
6861 int inter_float
= FLOAT_TYPE_P (inter_type
);
6862 int inter_vec
= TREE_CODE (inter_type
) == VECTOR_TYPE
;
6863 unsigned int inter_prec
= TYPE_PRECISION (inter_type
);
6864 int inter_unsignedp
= TYPE_UNSIGNED (inter_type
);
6865 int final_int
= INTEGRAL_TYPE_P (type
);
6866 int final_ptr
= POINTER_TYPE_P (type
);
6867 int final_float
= FLOAT_TYPE_P (type
);
6868 int final_vec
= TREE_CODE (type
) == VECTOR_TYPE
;
6869 unsigned int final_prec
= TYPE_PRECISION (type
);
6870 int final_unsignedp
= TYPE_UNSIGNED (type
);
6872 /* In addition to the cases of two conversions in a row
6873 handled below, if we are converting something to its own
6874 type via an object of identical or wider precision, neither
6875 conversion is needed. */
6876 if (TYPE_MAIN_VARIANT (inside_type
) == TYPE_MAIN_VARIANT (type
)
6877 && ((inter_int
&& final_int
) || (inter_float
&& final_float
))
6878 && inter_prec
>= final_prec
)
6879 return fold_build1 (code
, type
, TREE_OPERAND (op0
, 0));
6881 /* Likewise, if the intermediate and final types are either both
6882 float or both integer, we don't need the middle conversion if
6883 it is wider than the final type and doesn't change the signedness
6884 (for integers). Avoid this if the final type is a pointer
6885 since then we sometimes need the inner conversion. Likewise if
6886 the outer has a precision not equal to the size of its mode. */
6887 if ((((inter_int
|| inter_ptr
) && (inside_int
|| inside_ptr
))
6888 || (inter_float
&& inside_float
)
6889 || (inter_vec
&& inside_vec
))
6890 && inter_prec
>= inside_prec
6891 && (inter_float
|| inter_vec
6892 || inter_unsignedp
== inside_unsignedp
)
6893 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (type
))
6894 && TYPE_MODE (type
) == TYPE_MODE (inter_type
))
6896 && (! final_vec
|| inter_prec
== inside_prec
))
6897 return fold_build1 (code
, type
, TREE_OPERAND (op0
, 0));
6899 /* If we have a sign-extension of a zero-extended value, we can
6900 replace that by a single zero-extension. */
6901 if (inside_int
&& inter_int
&& final_int
6902 && inside_prec
< inter_prec
&& inter_prec
< final_prec
6903 && inside_unsignedp
&& !inter_unsignedp
)
6904 return fold_build1 (code
, type
, TREE_OPERAND (op0
, 0));
6906 /* Two conversions in a row are not needed unless:
6907 - some conversion is floating-point (overstrict for now), or
6908 - some conversion is a vector (overstrict for now), or
6909 - the intermediate type is narrower than both initial and
6911 - the intermediate type and innermost type differ in signedness,
6912 and the outermost type is wider than the intermediate, or
6913 - the initial type is a pointer type and the precisions of the
6914 intermediate and final types differ, or
6915 - the final type is a pointer type and the precisions of the
6916 initial and intermediate types differ. */
6917 if (! inside_float
&& ! inter_float
&& ! final_float
6918 && ! inside_vec
&& ! inter_vec
&& ! final_vec
6919 && (inter_prec
> inside_prec
|| inter_prec
> final_prec
)
6920 && ! (inside_int
&& inter_int
6921 && inter_unsignedp
!= inside_unsignedp
6922 && inter_prec
< final_prec
)
6923 && ((inter_unsignedp
&& inter_prec
> inside_prec
)
6924 == (final_unsignedp
&& final_prec
> inter_prec
))
6925 && ! (inside_ptr
&& inter_prec
!= final_prec
)
6926 && ! (final_ptr
&& inside_prec
!= inter_prec
)
6927 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (type
))
6928 && TYPE_MODE (type
) == TYPE_MODE (inter_type
))
6930 return fold_build1 (code
, type
, TREE_OPERAND (op0
, 0));
6933 /* Handle (T *)&A.B.C for A being of type T and B and C
6934 living at offset zero. This occurs frequently in
6935 C++ upcasting and then accessing the base. */
6936 if (TREE_CODE (op0
) == ADDR_EXPR
6937 && POINTER_TYPE_P (type
)
6938 && handled_component_p (TREE_OPERAND (op0
, 0)))
6940 HOST_WIDE_INT bitsize
, bitpos
;
6942 enum machine_mode mode
;
6943 int unsignedp
, volatilep
;
6944 tree base
= TREE_OPERAND (op0
, 0);
6945 base
= get_inner_reference (base
, &bitsize
, &bitpos
, &offset
,
6946 &mode
, &unsignedp
, &volatilep
, false);
6947 /* If the reference was to a (constant) zero offset, we can use
6948 the address of the base if it has the same base type
6949 as the result type. */
6950 if (! offset
&& bitpos
== 0
6951 && TYPE_MAIN_VARIANT (TREE_TYPE (type
))
6952 == TYPE_MAIN_VARIANT (TREE_TYPE (base
)))
6953 return fold_convert (type
, build_fold_addr_expr (base
));
6956 if (TREE_CODE (op0
) == MODIFY_EXPR
6957 && TREE_CONSTANT (TREE_OPERAND (op0
, 1))
6958 /* Detect assigning a bitfield. */
6959 && !(TREE_CODE (TREE_OPERAND (op0
, 0)) == COMPONENT_REF
6960 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (op0
, 0), 1))))
6962 /* Don't leave an assignment inside a conversion
6963 unless assigning a bitfield. */
6964 tem
= fold_build1 (code
, type
, TREE_OPERAND (op0
, 1));
6965 /* First do the assignment, then return converted constant. */
6966 tem
= build2 (COMPOUND_EXPR
, TREE_TYPE (tem
), op0
, tem
);
6967 TREE_NO_WARNING (tem
) = 1;
6968 TREE_USED (tem
) = 1;
6972 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
6973 constants (if x has signed type, the sign bit cannot be set
6974 in c). This folds extension into the BIT_AND_EXPR. */
6975 if (INTEGRAL_TYPE_P (type
)
6976 && TREE_CODE (type
) != BOOLEAN_TYPE
6977 && TREE_CODE (op0
) == BIT_AND_EXPR
6978 && TREE_CODE (TREE_OPERAND (op0
, 1)) == INTEGER_CST
)
6981 tree and0
= TREE_OPERAND (and, 0), and1
= TREE_OPERAND (and, 1);
6984 if (TYPE_UNSIGNED (TREE_TYPE (and))
6985 || (TYPE_PRECISION (type
)
6986 <= TYPE_PRECISION (TREE_TYPE (and))))
6988 else if (TYPE_PRECISION (TREE_TYPE (and1
))
6989 <= HOST_BITS_PER_WIDE_INT
6990 && host_integerp (and1
, 1))
6992 unsigned HOST_WIDE_INT cst
;
6994 cst
= tree_low_cst (and1
, 1);
6995 cst
&= (HOST_WIDE_INT
) -1
6996 << (TYPE_PRECISION (TREE_TYPE (and1
)) - 1);
6997 change
= (cst
== 0);
6998 #ifdef LOAD_EXTEND_OP
7000 && !flag_syntax_only
7001 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0
)))
7004 tree uns
= lang_hooks
.types
.unsigned_type (TREE_TYPE (and0
));
7005 and0
= fold_convert (uns
, and0
);
7006 and1
= fold_convert (uns
, and1
);
7012 tem
= build_int_cst_wide (type
, TREE_INT_CST_LOW (and1
),
7013 TREE_INT_CST_HIGH (and1
));
7014 tem
= force_fit_type (tem
, 0, TREE_OVERFLOW (and1
),
7015 TREE_CONSTANT_OVERFLOW (and1
));
7016 return fold_build2 (BIT_AND_EXPR
, type
,
7017 fold_convert (type
, and0
), tem
);
7021 /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
7022 T2 being pointers to types of the same size. */
7023 if (POINTER_TYPE_P (type
)
7024 && BINARY_CLASS_P (arg0
)
7025 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == NOP_EXPR
7026 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
7028 tree arg00
= TREE_OPERAND (arg0
, 0);
7030 tree t1
= TREE_TYPE (arg00
);
7031 tree tt0
= TREE_TYPE (t0
);
7032 tree tt1
= TREE_TYPE (t1
);
7033 tree s0
= TYPE_SIZE (tt0
);
7034 tree s1
= TYPE_SIZE (tt1
);
7036 if (s0
&& s1
&& operand_equal_p (s0
, s1
, OEP_ONLY_CONST
))
7037 return build2 (TREE_CODE (arg0
), t0
, fold_convert (t0
, arg00
),
7038 TREE_OPERAND (arg0
, 1));
7041 tem
= fold_convert_const (code
, type
, arg0
);
7042 return tem
? tem
: NULL_TREE
;
7044 case VIEW_CONVERT_EXPR
:
7045 if (TREE_CODE (op0
) == VIEW_CONVERT_EXPR
)
7046 return build1 (VIEW_CONVERT_EXPR
, type
, TREE_OPERAND (op0
, 0));
7050 if (negate_expr_p (arg0
))
7051 return fold_convert (type
, negate_expr (arg0
));
7055 if (TREE_CODE (arg0
) == INTEGER_CST
|| TREE_CODE (arg0
) == REAL_CST
)
7056 return fold_abs_const (arg0
, type
);
7057 else if (TREE_CODE (arg0
) == NEGATE_EXPR
)
7058 return fold_build1 (ABS_EXPR
, type
, TREE_OPERAND (arg0
, 0));
7059 /* Convert fabs((double)float) into (double)fabsf(float). */
7060 else if (TREE_CODE (arg0
) == NOP_EXPR
7061 && TREE_CODE (type
) == REAL_TYPE
)
7063 tree targ0
= strip_float_extensions (arg0
);
7065 return fold_convert (type
, fold_build1 (ABS_EXPR
,
7069 /* ABS_EXPR<ABS_EXPR<x>> = ABS_EXPR<x> even if flag_wrapv is on. */
7070 else if (tree_expr_nonnegative_p (arg0
) || TREE_CODE (arg0
) == ABS_EXPR
)
7073 /* Strip sign ops from argument. */
7074 if (TREE_CODE (type
) == REAL_TYPE
)
7076 tem
= fold_strip_sign_ops (arg0
);
7078 return fold_build1 (ABS_EXPR
, type
, fold_convert (type
, tem
));
7083 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
7084 return fold_convert (type
, arg0
);
7085 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
7086 return build2 (COMPLEX_EXPR
, type
,
7087 TREE_OPERAND (arg0
, 0),
7088 negate_expr (TREE_OPERAND (arg0
, 1)));
7089 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
7090 return build_complex (type
, TREE_REALPART (arg0
),
7091 negate_expr (TREE_IMAGPART (arg0
)));
7092 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
7093 return fold_build2 (TREE_CODE (arg0
), type
,
7094 fold_build1 (CONJ_EXPR
, type
,
7095 TREE_OPERAND (arg0
, 0)),
7096 fold_build1 (CONJ_EXPR
, type
,
7097 TREE_OPERAND (arg0
, 1)));
7098 else if (TREE_CODE (arg0
) == CONJ_EXPR
)
7099 return TREE_OPERAND (arg0
, 0);
7103 if (TREE_CODE (arg0
) == INTEGER_CST
)
7104 return fold_not_const (arg0
, type
);
7105 else if (TREE_CODE (arg0
) == BIT_NOT_EXPR
)
7106 return TREE_OPERAND (arg0
, 0);
7107 /* Convert ~ (-A) to A - 1. */
7108 else if (INTEGRAL_TYPE_P (type
) && TREE_CODE (arg0
) == NEGATE_EXPR
)
7109 return fold_build2 (MINUS_EXPR
, type
, TREE_OPERAND (arg0
, 0),
7110 build_int_cst (type
, 1));
7111 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
7112 else if (INTEGRAL_TYPE_P (type
)
7113 && ((TREE_CODE (arg0
) == MINUS_EXPR
7114 && integer_onep (TREE_OPERAND (arg0
, 1)))
7115 || (TREE_CODE (arg0
) == PLUS_EXPR
7116 && integer_all_onesp (TREE_OPERAND (arg0
, 1)))))
7117 return fold_build1 (NEGATE_EXPR
, type
, TREE_OPERAND (arg0
, 0));
7118 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
7119 else if (TREE_CODE (arg0
) == BIT_XOR_EXPR
7120 && (tem
= fold_unary (BIT_NOT_EXPR
, type
,
7122 TREE_OPERAND (arg0
, 0)))))
7123 return fold_build2 (BIT_XOR_EXPR
, type
, tem
,
7124 fold_convert (type
, TREE_OPERAND (arg0
, 1)));
7125 else if (TREE_CODE (arg0
) == BIT_XOR_EXPR
7126 && (tem
= fold_unary (BIT_NOT_EXPR
, type
,
7128 TREE_OPERAND (arg0
, 1)))))
7129 return fold_build2 (BIT_XOR_EXPR
, type
,
7130 fold_convert (type
, TREE_OPERAND (arg0
, 0)), tem
);
7134 case TRUTH_NOT_EXPR
:
7135 /* The argument to invert_truthvalue must have Boolean type. */
7136 if (TREE_CODE (TREE_TYPE (arg0
)) != BOOLEAN_TYPE
)
7137 arg0
= fold_convert (boolean_type_node
, arg0
);
7139 /* Note that the operand of this must be an int
7140 and its values must be 0 or 1.
7141 ("true" is a fixed value perhaps depending on the language,
7142 but we don't handle values other than 1 correctly yet.) */
7143 tem
= invert_truthvalue (arg0
);
7144 /* Avoid infinite recursion. */
7145 if (TREE_CODE (tem
) == TRUTH_NOT_EXPR
)
7147 return fold_convert (type
, tem
);
7150 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
7152 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
7153 return omit_one_operand (type
, TREE_OPERAND (arg0
, 0),
7154 TREE_OPERAND (arg0
, 1));
7155 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
7156 return TREE_REALPART (arg0
);
7157 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
7158 return fold_build2 (TREE_CODE (arg0
), type
,
7159 fold_build1 (REALPART_EXPR
, type
,
7160 TREE_OPERAND (arg0
, 0)),
7161 fold_build1 (REALPART_EXPR
, type
,
7162 TREE_OPERAND (arg0
, 1)));
7166 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
7167 return fold_convert (type
, integer_zero_node
);
7168 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
7169 return omit_one_operand (type
, TREE_OPERAND (arg0
, 1),
7170 TREE_OPERAND (arg0
, 0));
7171 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
7172 return TREE_IMAGPART (arg0
);
7173 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
7174 return fold_build2 (TREE_CODE (arg0
), type
,
7175 fold_build1 (IMAGPART_EXPR
, type
,
7176 TREE_OPERAND (arg0
, 0)),
7177 fold_build1 (IMAGPART_EXPR
, type
,
7178 TREE_OPERAND (arg0
, 1)));
7183 } /* switch (code) */
7186 /* Fold a binary expression of code CODE and type TYPE with operands
7187 OP0 and OP1, containing either a MIN-MAX or a MAX-MIN combination.
7188 Return the folded expression if folding is successful. Otherwise,
7189 return NULL_TREE. */
7192 fold_minmax (enum tree_code code
, tree type
, tree op0
, tree op1
)
7194 enum tree_code compl_code
;
7196 if (code
== MIN_EXPR
)
7197 compl_code
= MAX_EXPR
;
7198 else if (code
== MAX_EXPR
)
7199 compl_code
= MIN_EXPR
;
7203 /* MIN (MAX (a, b), b) == b. Â */
7204 if (TREE_CODE (op0
) == compl_code
7205 && operand_equal_p (TREE_OPERAND (op0
, 1), op1
, 0))
7206 return omit_one_operand (type
, op1
, TREE_OPERAND (op0
, 0));
7208 /* MIN (MAX (b, a), b) == b. Â */
7209 if (TREE_CODE (op0
) == compl_code
7210 && operand_equal_p (TREE_OPERAND (op0
, 0), op1
, 0)
7211 && reorder_operands_p (TREE_OPERAND (op0
, 1), op1
))
7212 return omit_one_operand (type
, op1
, TREE_OPERAND (op0
, 1));
7214 /* MIN (a, MAX (a, b)) == a. Â */
7215 if (TREE_CODE (op1
) == compl_code
7216 && operand_equal_p (op0
, TREE_OPERAND (op1
, 0), 0)
7217 && reorder_operands_p (op0
, TREE_OPERAND (op1
, 1)))
7218 return omit_one_operand (type
, op0
, TREE_OPERAND (op1
, 1));
7220 /* MIN (a, MAX (b, a)) == a. Â */
7221 if (TREE_CODE (op1
) == compl_code
7222 && operand_equal_p (op0
, TREE_OPERAND (op1
, 1), 0)
7223 && reorder_operands_p (op0
, TREE_OPERAND (op1
, 0)))
7224 return omit_one_operand (type
, op0
, TREE_OPERAND (op1
, 0));
7229 /* Fold a binary expression of code CODE and type TYPE with operands
7230 OP0 and OP1. Return the folded expression if folding is
7231 successful. Otherwise, return NULL_TREE. */
7234 fold_binary (enum tree_code code
, tree type
, tree op0
, tree op1
)
7236 tree t1
= NULL_TREE
;
7238 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
;
7239 enum tree_code_class kind
= TREE_CODE_CLASS (code
);
7241 gcc_assert (IS_EXPR_CODE_CLASS (kind
)
7242 && TREE_CODE_LENGTH (code
) == 2
7244 && op1
!= NULL_TREE
);
7249 /* Strip any conversions that don't change the mode. This is
7250 safe for every expression, except for a comparison expression
7251 because its signedness is derived from its operands. So, in
7252 the latter case, only strip conversions that don't change the
7255 Note that this is done as an internal manipulation within the
7256 constant folder, in order to find the simplest representation
7257 of the arguments so that their form can be studied. In any
7258 cases, the appropriate type conversions should be put back in
7259 the tree that will get out of the constant folder. */
7261 if (kind
== tcc_comparison
)
7263 STRIP_SIGN_NOPS (arg0
);
7264 STRIP_SIGN_NOPS (arg1
);
7272 /* Note that TREE_CONSTANT isn't enough: static var addresses are
7273 constant but we can't do arithmetic on them. */
7274 if ((TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
7275 || (TREE_CODE (arg0
) == REAL_CST
&& TREE_CODE (arg1
) == REAL_CST
)
7276 || (TREE_CODE (arg0
) == COMPLEX_CST
&& TREE_CODE (arg1
) == COMPLEX_CST
)
7277 || (TREE_CODE (arg0
) == VECTOR_CST
&& TREE_CODE (arg1
) == VECTOR_CST
))
7279 if (kind
== tcc_binary
)
7280 tem
= const_binop (code
, arg0
, arg1
, 0);
7281 else if (kind
== tcc_comparison
)
7282 tem
= fold_relational_const (code
, type
, arg0
, arg1
);
7286 if (tem
!= NULL_TREE
)
7288 if (TREE_TYPE (tem
) != type
)
7289 tem
= fold_convert (type
, tem
);
7294 /* If this is a commutative operation, and ARG0 is a constant, move it
7295 to ARG1 to reduce the number of tests below. */
7296 if (commutative_tree_code (code
)
7297 && tree_swap_operands_p (arg0
, arg1
, true))
7298 return fold_build2 (code
, type
, op1
, op0
);
7300 /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
7302 First check for cases where an arithmetic operation is applied to a
7303 compound, conditional, or comparison operation. Push the arithmetic
7304 operation inside the compound or conditional to see if any folding
7305 can then be done. Convert comparison to conditional for this purpose.
7306 The also optimizes non-constant cases that used to be done in
7309 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
7310 one of the operands is a comparison and the other is a comparison, a
7311 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
7312 code below would make the expression more complex. Change it to a
7313 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
7314 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
7316 if ((code
== BIT_AND_EXPR
|| code
== BIT_IOR_EXPR
7317 || code
== EQ_EXPR
|| code
== NE_EXPR
)
7318 && ((truth_value_p (TREE_CODE (arg0
))
7319 && (truth_value_p (TREE_CODE (arg1
))
7320 || (TREE_CODE (arg1
) == BIT_AND_EXPR
7321 && integer_onep (TREE_OPERAND (arg1
, 1)))))
7322 || (truth_value_p (TREE_CODE (arg1
))
7323 && (truth_value_p (TREE_CODE (arg0
))
7324 || (TREE_CODE (arg0
) == BIT_AND_EXPR
7325 && integer_onep (TREE_OPERAND (arg0
, 1)))))))
7327 tem
= fold_build2 (code
== BIT_AND_EXPR
? TRUTH_AND_EXPR
7328 : code
== BIT_IOR_EXPR
? TRUTH_OR_EXPR
7331 fold_convert (boolean_type_node
, arg0
),
7332 fold_convert (boolean_type_node
, arg1
));
7334 if (code
== EQ_EXPR
)
7335 tem
= invert_truthvalue (tem
);
7337 return fold_convert (type
, tem
);
7340 if (TREE_CODE_CLASS (code
) == tcc_binary
7341 || TREE_CODE_CLASS (code
) == tcc_comparison
)
7343 if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
7344 return build2 (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
7345 fold_build2 (code
, type
,
7346 TREE_OPERAND (arg0
, 1), op1
));
7347 if (TREE_CODE (arg1
) == COMPOUND_EXPR
7348 && reorder_operands_p (arg0
, TREE_OPERAND (arg1
, 0)))
7349 return build2 (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
7350 fold_build2 (code
, type
,
7351 op0
, TREE_OPERAND (arg1
, 1)));
7353 if (TREE_CODE (arg0
) == COND_EXPR
|| COMPARISON_CLASS_P (arg0
))
7355 tem
= fold_binary_op_with_conditional_arg (code
, type
, op0
, op1
,
7357 /*cond_first_p=*/1);
7358 if (tem
!= NULL_TREE
)
7362 if (TREE_CODE (arg1
) == COND_EXPR
|| COMPARISON_CLASS_P (arg1
))
7364 tem
= fold_binary_op_with_conditional_arg (code
, type
, op0
, op1
,
7366 /*cond_first_p=*/0);
7367 if (tem
!= NULL_TREE
)
7375 /* A + (-B) -> A - B */
7376 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
7377 return fold_build2 (MINUS_EXPR
, type
,
7378 fold_convert (type
, arg0
),
7379 fold_convert (type
, TREE_OPERAND (arg1
, 0)));
7380 /* (-A) + B -> B - A */
7381 if (TREE_CODE (arg0
) == NEGATE_EXPR
7382 && reorder_operands_p (TREE_OPERAND (arg0
, 0), arg1
))
7383 return fold_build2 (MINUS_EXPR
, type
,
7384 fold_convert (type
, arg1
),
7385 fold_convert (type
, TREE_OPERAND (arg0
, 0)));
7386 /* Convert ~A + 1 to -A. */
7387 if (INTEGRAL_TYPE_P (type
)
7388 && TREE_CODE (arg0
) == BIT_NOT_EXPR
7389 && integer_onep (arg1
))
7390 return fold_build1 (NEGATE_EXPR
, type
, TREE_OPERAND (arg0
, 0));
7392 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
7394 if ((TREE_CODE (arg0
) == MULT_EXPR
7395 || TREE_CODE (arg1
) == MULT_EXPR
)
7396 && (!FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
))
7398 tree tem
= fold_plusminus_mult_expr (code
, type
, arg0
, arg1
);
7403 if (! FLOAT_TYPE_P (type
))
7405 if (integer_zerop (arg1
))
7406 return non_lvalue (fold_convert (type
, arg0
));
7408 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
7409 with a constant, and the two constants have no bits in common,
7410 we should treat this as a BIT_IOR_EXPR since this may produce more
7412 if (TREE_CODE (arg0
) == BIT_AND_EXPR
7413 && TREE_CODE (arg1
) == BIT_AND_EXPR
7414 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
7415 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
7416 && integer_zerop (const_binop (BIT_AND_EXPR
,
7417 TREE_OPERAND (arg0
, 1),
7418 TREE_OPERAND (arg1
, 1), 0)))
7420 code
= BIT_IOR_EXPR
;
7424 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
7425 (plus (plus (mult) (mult)) (foo)) so that we can
7426 take advantage of the factoring cases below. */
7427 if (((TREE_CODE (arg0
) == PLUS_EXPR
7428 || TREE_CODE (arg0
) == MINUS_EXPR
)
7429 && TREE_CODE (arg1
) == MULT_EXPR
)
7430 || ((TREE_CODE (arg1
) == PLUS_EXPR
7431 || TREE_CODE (arg1
) == MINUS_EXPR
)
7432 && TREE_CODE (arg0
) == MULT_EXPR
))
7434 tree parg0
, parg1
, parg
, marg
;
7435 enum tree_code pcode
;
7437 if (TREE_CODE (arg1
) == MULT_EXPR
)
7438 parg
= arg0
, marg
= arg1
;
7440 parg
= arg1
, marg
= arg0
;
7441 pcode
= TREE_CODE (parg
);
7442 parg0
= TREE_OPERAND (parg
, 0);
7443 parg1
= TREE_OPERAND (parg
, 1);
7447 if (TREE_CODE (parg0
) == MULT_EXPR
7448 && TREE_CODE (parg1
) != MULT_EXPR
)
7449 return fold_build2 (pcode
, type
,
7450 fold_build2 (PLUS_EXPR
, type
,
7451 fold_convert (type
, parg0
),
7452 fold_convert (type
, marg
)),
7453 fold_convert (type
, parg1
));
7454 if (TREE_CODE (parg0
) != MULT_EXPR
7455 && TREE_CODE (parg1
) == MULT_EXPR
)
7456 return fold_build2 (PLUS_EXPR
, type
,
7457 fold_convert (type
, parg0
),
7458 fold_build2 (pcode
, type
,
7459 fold_convert (type
, marg
),
7464 /* Try replacing &a[i1] + c * i2 with &a[i1 + i2], if c is step
7465 of the array. Loop optimizer sometimes produce this type of
7467 if (TREE_CODE (arg0
) == ADDR_EXPR
)
7469 tem
= try_move_mult_to_index (PLUS_EXPR
, arg0
, arg1
);
7471 return fold_convert (type
, tem
);
7473 else if (TREE_CODE (arg1
) == ADDR_EXPR
)
7475 tem
= try_move_mult_to_index (PLUS_EXPR
, arg1
, arg0
);
7477 return fold_convert (type
, tem
);
7482 /* See if ARG1 is zero and X + ARG1 reduces to X. */
7483 if (fold_real_zero_addition_p (TREE_TYPE (arg0
), arg1
, 0))
7484 return non_lvalue (fold_convert (type
, arg0
));
7486 /* Likewise if the operands are reversed. */
7487 if (fold_real_zero_addition_p (TREE_TYPE (arg1
), arg0
, 0))
7488 return non_lvalue (fold_convert (type
, arg1
));
7490 /* Convert X + -C into X - C. */
7491 if (TREE_CODE (arg1
) == REAL_CST
7492 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1
)))
7494 tem
= fold_negate_const (arg1
, type
);
7495 if (!TREE_OVERFLOW (arg1
) || !flag_trapping_math
)
7496 return fold_build2 (MINUS_EXPR
, type
,
7497 fold_convert (type
, arg0
),
7498 fold_convert (type
, tem
));
7501 if (flag_unsafe_math_optimizations
7502 && (TREE_CODE (arg0
) == RDIV_EXPR
|| TREE_CODE (arg0
) == MULT_EXPR
)
7503 && (TREE_CODE (arg1
) == RDIV_EXPR
|| TREE_CODE (arg1
) == MULT_EXPR
)
7504 && (tem
= distribute_real_division (code
, type
, arg0
, arg1
)))
7507 /* Convert x+x into x*2.0. */
7508 if (operand_equal_p (arg0
, arg1
, 0)
7509 && SCALAR_FLOAT_TYPE_P (type
))
7510 return fold_build2 (MULT_EXPR
, type
, arg0
,
7511 build_real (type
, dconst2
));
7513 /* Convert a + (b*c + d*e) into (a + b*c) + d*e. */
7514 if (flag_unsafe_math_optimizations
7515 && TREE_CODE (arg1
) == PLUS_EXPR
7516 && TREE_CODE (arg0
) != MULT_EXPR
)
7518 tree tree10
= TREE_OPERAND (arg1
, 0);
7519 tree tree11
= TREE_OPERAND (arg1
, 1);
7520 if (TREE_CODE (tree11
) == MULT_EXPR
7521 && TREE_CODE (tree10
) == MULT_EXPR
)
7524 tree0
= fold_build2 (PLUS_EXPR
, type
, arg0
, tree10
);
7525 return fold_build2 (PLUS_EXPR
, type
, tree0
, tree11
);
7528 /* Convert (b*c + d*e) + a into b*c + (d*e +a). */
7529 if (flag_unsafe_math_optimizations
7530 && TREE_CODE (arg0
) == PLUS_EXPR
7531 && TREE_CODE (arg1
) != MULT_EXPR
)
7533 tree tree00
= TREE_OPERAND (arg0
, 0);
7534 tree tree01
= TREE_OPERAND (arg0
, 1);
7535 if (TREE_CODE (tree01
) == MULT_EXPR
7536 && TREE_CODE (tree00
) == MULT_EXPR
)
7539 tree0
= fold_build2 (PLUS_EXPR
, type
, tree01
, arg1
);
7540 return fold_build2 (PLUS_EXPR
, type
, tree00
, tree0
);
7546 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
7547 is a rotate of A by C1 bits. */
7548 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
7549 is a rotate of A by B bits. */
7551 enum tree_code code0
, code1
;
7552 code0
= TREE_CODE (arg0
);
7553 code1
= TREE_CODE (arg1
);
7554 if (((code0
== RSHIFT_EXPR
&& code1
== LSHIFT_EXPR
)
7555 || (code1
== RSHIFT_EXPR
&& code0
== LSHIFT_EXPR
))
7556 && operand_equal_p (TREE_OPERAND (arg0
, 0),
7557 TREE_OPERAND (arg1
, 0), 0)
7558 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
7560 tree tree01
, tree11
;
7561 enum tree_code code01
, code11
;
7563 tree01
= TREE_OPERAND (arg0
, 1);
7564 tree11
= TREE_OPERAND (arg1
, 1);
7565 STRIP_NOPS (tree01
);
7566 STRIP_NOPS (tree11
);
7567 code01
= TREE_CODE (tree01
);
7568 code11
= TREE_CODE (tree11
);
7569 if (code01
== INTEGER_CST
7570 && code11
== INTEGER_CST
7571 && TREE_INT_CST_HIGH (tree01
) == 0
7572 && TREE_INT_CST_HIGH (tree11
) == 0
7573 && ((TREE_INT_CST_LOW (tree01
) + TREE_INT_CST_LOW (tree11
))
7574 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)))))
7575 return build2 (LROTATE_EXPR
, type
, TREE_OPERAND (arg0
, 0),
7576 code0
== LSHIFT_EXPR
? tree01
: tree11
);
7577 else if (code11
== MINUS_EXPR
)
7579 tree tree110
, tree111
;
7580 tree110
= TREE_OPERAND (tree11
, 0);
7581 tree111
= TREE_OPERAND (tree11
, 1);
7582 STRIP_NOPS (tree110
);
7583 STRIP_NOPS (tree111
);
7584 if (TREE_CODE (tree110
) == INTEGER_CST
7585 && 0 == compare_tree_int (tree110
,
7587 (TREE_TYPE (TREE_OPERAND
7589 && operand_equal_p (tree01
, tree111
, 0))
7590 return build2 ((code0
== LSHIFT_EXPR
7593 type
, TREE_OPERAND (arg0
, 0), tree01
);
7595 else if (code01
== MINUS_EXPR
)
7597 tree tree010
, tree011
;
7598 tree010
= TREE_OPERAND (tree01
, 0);
7599 tree011
= TREE_OPERAND (tree01
, 1);
7600 STRIP_NOPS (tree010
);
7601 STRIP_NOPS (tree011
);
7602 if (TREE_CODE (tree010
) == INTEGER_CST
7603 && 0 == compare_tree_int (tree010
,
7605 (TREE_TYPE (TREE_OPERAND
7607 && operand_equal_p (tree11
, tree011
, 0))
7608 return build2 ((code0
!= LSHIFT_EXPR
7611 type
, TREE_OPERAND (arg0
, 0), tree11
);
7617 /* In most languages, can't associate operations on floats through
7618 parentheses. Rather than remember where the parentheses were, we
7619 don't associate floats at all, unless the user has specified
7620 -funsafe-math-optimizations. */
7622 if (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
7624 tree var0
, con0
, lit0
, minus_lit0
;
7625 tree var1
, con1
, lit1
, minus_lit1
;
7627 /* Split both trees into variables, constants, and literals. Then
7628 associate each group together, the constants with literals,
7629 then the result with variables. This increases the chances of
7630 literals being recombined later and of generating relocatable
7631 expressions for the sum of a constant and literal. */
7632 var0
= split_tree (arg0
, code
, &con0
, &lit0
, &minus_lit0
, 0);
7633 var1
= split_tree (arg1
, code
, &con1
, &lit1
, &minus_lit1
,
7634 code
== MINUS_EXPR
);
7636 /* Only do something if we found more than two objects. Otherwise,
7637 nothing has changed and we risk infinite recursion. */
7638 if (2 < ((var0
!= 0) + (var1
!= 0)
7639 + (con0
!= 0) + (con1
!= 0)
7640 + (lit0
!= 0) + (lit1
!= 0)
7641 + (minus_lit0
!= 0) + (minus_lit1
!= 0)))
7643 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
7644 if (code
== MINUS_EXPR
)
7647 var0
= associate_trees (var0
, var1
, code
, type
);
7648 con0
= associate_trees (con0
, con1
, code
, type
);
7649 lit0
= associate_trees (lit0
, lit1
, code
, type
);
7650 minus_lit0
= associate_trees (minus_lit0
, minus_lit1
, code
, type
);
7652 /* Preserve the MINUS_EXPR if the negative part of the literal is
7653 greater than the positive part. Otherwise, the multiplicative
7654 folding code (i.e extract_muldiv) may be fooled in case
7655 unsigned constants are subtracted, like in the following
7656 example: ((X*2 + 4) - 8U)/2. */
7657 if (minus_lit0
&& lit0
)
7659 if (TREE_CODE (lit0
) == INTEGER_CST
7660 && TREE_CODE (minus_lit0
) == INTEGER_CST
7661 && tree_int_cst_lt (lit0
, minus_lit0
))
7663 minus_lit0
= associate_trees (minus_lit0
, lit0
,
7669 lit0
= associate_trees (lit0
, minus_lit0
,
7677 return fold_convert (type
,
7678 associate_trees (var0
, minus_lit0
,
7682 con0
= associate_trees (con0
, minus_lit0
,
7684 return fold_convert (type
,
7685 associate_trees (var0
, con0
,
7690 con0
= associate_trees (con0
, lit0
, code
, type
);
7691 return fold_convert (type
, associate_trees (var0
, con0
,
7699 /* A - (-B) -> A + B */
7700 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
7701 return fold_build2 (PLUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0));
7702 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
7703 if (TREE_CODE (arg0
) == NEGATE_EXPR
7704 && (FLOAT_TYPE_P (type
)
7705 || (INTEGRAL_TYPE_P (type
) && flag_wrapv
&& !flag_trapv
))
7706 && negate_expr_p (arg1
)
7707 && reorder_operands_p (arg0
, arg1
))
7708 return fold_build2 (MINUS_EXPR
, type
, negate_expr (arg1
),
7709 TREE_OPERAND (arg0
, 0));
7710 /* Convert -A - 1 to ~A. */
7711 if (INTEGRAL_TYPE_P (type
)
7712 && TREE_CODE (arg0
) == NEGATE_EXPR
7713 && integer_onep (arg1
))
7714 return fold_build1 (BIT_NOT_EXPR
, type
, TREE_OPERAND (arg0
, 0));
7716 /* Convert -1 - A to ~A. */
7717 if (INTEGRAL_TYPE_P (type
)
7718 && integer_all_onesp (arg0
))
7719 return fold_build1 (BIT_NOT_EXPR
, type
, arg1
);
7721 if (! FLOAT_TYPE_P (type
))
7723 if (integer_zerop (arg0
))
7724 return negate_expr (fold_convert (type
, arg1
));
7725 if (integer_zerop (arg1
))
7726 return non_lvalue (fold_convert (type
, arg0
));
7728 /* Fold A - (A & B) into ~B & A. */
7729 if (!TREE_SIDE_EFFECTS (arg0
)
7730 && TREE_CODE (arg1
) == BIT_AND_EXPR
)
7732 if (operand_equal_p (arg0
, TREE_OPERAND (arg1
, 1), 0))
7733 return fold_build2 (BIT_AND_EXPR
, type
,
7734 fold_build1 (BIT_NOT_EXPR
, type
,
7735 TREE_OPERAND (arg1
, 0)),
7737 if (operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
7738 return fold_build2 (BIT_AND_EXPR
, type
,
7739 fold_build1 (BIT_NOT_EXPR
, type
,
7740 TREE_OPERAND (arg1
, 1)),
7744 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
7745 any power of 2 minus 1. */
7746 if (TREE_CODE (arg0
) == BIT_AND_EXPR
7747 && TREE_CODE (arg1
) == BIT_AND_EXPR
7748 && operand_equal_p (TREE_OPERAND (arg0
, 0),
7749 TREE_OPERAND (arg1
, 0), 0))
7751 tree mask0
= TREE_OPERAND (arg0
, 1);
7752 tree mask1
= TREE_OPERAND (arg1
, 1);
7753 tree tem
= fold_build1 (BIT_NOT_EXPR
, type
, mask0
);
7755 if (operand_equal_p (tem
, mask1
, 0))
7757 tem
= fold_build2 (BIT_XOR_EXPR
, type
,
7758 TREE_OPERAND (arg0
, 0), mask1
);
7759 return fold_build2 (MINUS_EXPR
, type
, tem
, mask1
);
7764 /* See if ARG1 is zero and X - ARG1 reduces to X. */
7765 else if (fold_real_zero_addition_p (TREE_TYPE (arg0
), arg1
, 1))
7766 return non_lvalue (fold_convert (type
, arg0
));
7768 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
7769 ARG0 is zero and X + ARG0 reduces to X, since that would mean
7770 (-ARG1 + ARG0) reduces to -ARG1. */
7771 else if (fold_real_zero_addition_p (TREE_TYPE (arg1
), arg0
, 0))
7772 return negate_expr (fold_convert (type
, arg1
));
7774 /* Fold &x - &x. This can happen from &x.foo - &x.
7775 This is unsafe for certain floats even in non-IEEE formats.
7776 In IEEE, it is unsafe because it does wrong for NaNs.
7777 Also note that operand_equal_p is always false if an operand
7780 if ((! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
7781 && operand_equal_p (arg0
, arg1
, 0))
7782 return fold_convert (type
, integer_zero_node
);
7784 /* A - B -> A + (-B) if B is easily negatable. */
7785 if (negate_expr_p (arg1
)
7786 && ((FLOAT_TYPE_P (type
)
7787 /* Avoid this transformation if B is a positive REAL_CST. */
7788 && (TREE_CODE (arg1
) != REAL_CST
7789 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1
))))
7790 || (INTEGRAL_TYPE_P (type
) && flag_wrapv
&& !flag_trapv
)))
7791 return fold_build2 (PLUS_EXPR
, type
,
7792 fold_convert (type
, arg0
),
7793 fold_convert (type
, negate_expr (arg1
)));
7795 /* Try folding difference of addresses. */
7799 if ((TREE_CODE (arg0
) == ADDR_EXPR
7800 || TREE_CODE (arg1
) == ADDR_EXPR
)
7801 && ptr_difference_const (arg0
, arg1
, &diff
))
7802 return build_int_cst_type (type
, diff
);
7805 /* Fold &a[i] - &a[j] to i-j. */
7806 if (TREE_CODE (arg0
) == ADDR_EXPR
7807 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == ARRAY_REF
7808 && TREE_CODE (arg1
) == ADDR_EXPR
7809 && TREE_CODE (TREE_OPERAND (arg1
, 0)) == ARRAY_REF
)
7811 tree aref0
= TREE_OPERAND (arg0
, 0);
7812 tree aref1
= TREE_OPERAND (arg1
, 0);
7813 if (operand_equal_p (TREE_OPERAND (aref0
, 0),
7814 TREE_OPERAND (aref1
, 0), 0))
7816 tree op0
= fold_convert (type
, TREE_OPERAND (aref0
, 1));
7817 tree op1
= fold_convert (type
, TREE_OPERAND (aref1
, 1));
7818 tree esz
= array_ref_element_size (aref0
);
7819 tree diff
= build2 (MINUS_EXPR
, type
, op0
, op1
);
7820 return fold_build2 (MULT_EXPR
, type
, diff
,
7821 fold_convert (type
, esz
));
7826 /* Try replacing &a[i1] - c * i2 with &a[i1 - i2], if c is step
7827 of the array. Loop optimizer sometimes produce this type of
7829 if (TREE_CODE (arg0
) == ADDR_EXPR
)
7831 tem
= try_move_mult_to_index (MINUS_EXPR
, arg0
, arg1
);
7833 return fold_convert (type
, tem
);
7836 if (flag_unsafe_math_optimizations
7837 && (TREE_CODE (arg0
) == RDIV_EXPR
|| TREE_CODE (arg0
) == MULT_EXPR
)
7838 && (TREE_CODE (arg1
) == RDIV_EXPR
|| TREE_CODE (arg1
) == MULT_EXPR
)
7839 && (tem
= distribute_real_division (code
, type
, arg0
, arg1
)))
7842 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the
7844 if ((TREE_CODE (arg0
) == MULT_EXPR
7845 || TREE_CODE (arg1
) == MULT_EXPR
)
7846 && (!FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
))
7848 tree tem
= fold_plusminus_mult_expr (code
, type
, arg0
, arg1
);
7856 /* (-A) * (-B) -> A * B */
7857 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& negate_expr_p (arg1
))
7858 return fold_build2 (MULT_EXPR
, type
,
7859 TREE_OPERAND (arg0
, 0),
7860 negate_expr (arg1
));
7861 if (TREE_CODE (arg1
) == NEGATE_EXPR
&& negate_expr_p (arg0
))
7862 return fold_build2 (MULT_EXPR
, type
,
7864 TREE_OPERAND (arg1
, 0));
7866 if (! FLOAT_TYPE_P (type
))
7868 if (integer_zerop (arg1
))
7869 return omit_one_operand (type
, arg1
, arg0
);
7870 if (integer_onep (arg1
))
7871 return non_lvalue (fold_convert (type
, arg0
));
7872 /* Transform x * -1 into -x. */
7873 if (integer_all_onesp (arg1
))
7874 return fold_convert (type
, negate_expr (arg0
));
7876 /* (a * (1 << b)) is (a << b) */
7877 if (TREE_CODE (arg1
) == LSHIFT_EXPR
7878 && integer_onep (TREE_OPERAND (arg1
, 0)))
7879 return fold_build2 (LSHIFT_EXPR
, type
, arg0
,
7880 TREE_OPERAND (arg1
, 1));
7881 if (TREE_CODE (arg0
) == LSHIFT_EXPR
7882 && integer_onep (TREE_OPERAND (arg0
, 0)))
7883 return fold_build2 (LSHIFT_EXPR
, type
, arg1
,
7884 TREE_OPERAND (arg0
, 1));
7886 if (TREE_CODE (arg1
) == INTEGER_CST
7887 && 0 != (tem
= extract_muldiv (op0
,
7888 fold_convert (type
, arg1
),
7890 return fold_convert (type
, tem
);
7895 /* Maybe fold x * 0 to 0. The expressions aren't the same
7896 when x is NaN, since x * 0 is also NaN. Nor are they the
7897 same in modes with signed zeros, since multiplying a
7898 negative value by 0 gives -0, not +0. */
7899 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
)))
7900 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0
)))
7901 && real_zerop (arg1
))
7902 return omit_one_operand (type
, arg1
, arg0
);
7903 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
7904 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
7905 && real_onep (arg1
))
7906 return non_lvalue (fold_convert (type
, arg0
));
7908 /* Transform x * -1.0 into -x. */
7909 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
7910 && real_minus_onep (arg1
))
7911 return fold_convert (type
, negate_expr (arg0
));
7913 /* Convert (C1/X)*C2 into (C1*C2)/X. */
7914 if (flag_unsafe_math_optimizations
7915 && TREE_CODE (arg0
) == RDIV_EXPR
7916 && TREE_CODE (arg1
) == REAL_CST
7917 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == REAL_CST
)
7919 tree tem
= const_binop (MULT_EXPR
, TREE_OPERAND (arg0
, 0),
7922 return fold_build2 (RDIV_EXPR
, type
, tem
,
7923 TREE_OPERAND (arg0
, 1));
7926 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
7927 if (operand_equal_p (arg0
, arg1
, 0))
7929 tree tem
= fold_strip_sign_ops (arg0
);
7930 if (tem
!= NULL_TREE
)
7932 tem
= fold_convert (type
, tem
);
7933 return fold_build2 (MULT_EXPR
, type
, tem
, tem
);
7937 if (flag_unsafe_math_optimizations
)
7939 enum built_in_function fcode0
= builtin_mathfn_code (arg0
);
7940 enum built_in_function fcode1
= builtin_mathfn_code (arg1
);
7942 /* Optimizations of root(...)*root(...). */
7943 if (fcode0
== fcode1
&& BUILTIN_ROOT_P (fcode0
))
7945 tree rootfn
, arg
, arglist
;
7946 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
7947 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
7949 /* Optimize sqrt(x)*sqrt(x) as x. */
7950 if (BUILTIN_SQRT_P (fcode0
)
7951 && operand_equal_p (arg00
, arg10
, 0)
7952 && ! HONOR_SNANS (TYPE_MODE (type
)))
7955 /* Optimize root(x)*root(y) as root(x*y). */
7956 rootfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
7957 arg
= fold_build2 (MULT_EXPR
, type
, arg00
, arg10
);
7958 arglist
= build_tree_list (NULL_TREE
, arg
);
7959 return build_function_call_expr (rootfn
, arglist
);
7962 /* Optimize expN(x)*expN(y) as expN(x+y). */
7963 if (fcode0
== fcode1
&& BUILTIN_EXPONENT_P (fcode0
))
7965 tree expfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
7966 tree arg
= fold_build2 (PLUS_EXPR
, type
,
7967 TREE_VALUE (TREE_OPERAND (arg0
, 1)),
7968 TREE_VALUE (TREE_OPERAND (arg1
, 1)));
7969 tree arglist
= build_tree_list (NULL_TREE
, arg
);
7970 return build_function_call_expr (expfn
, arglist
);
7973 /* Optimizations of pow(...)*pow(...). */
7974 if ((fcode0
== BUILT_IN_POW
&& fcode1
== BUILT_IN_POW
)
7975 || (fcode0
== BUILT_IN_POWF
&& fcode1
== BUILT_IN_POWF
)
7976 || (fcode0
== BUILT_IN_POWL
&& fcode1
== BUILT_IN_POWL
))
7978 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
7979 tree arg01
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0
,
7981 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
7982 tree arg11
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1
,
7985 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
7986 if (operand_equal_p (arg01
, arg11
, 0))
7988 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
7989 tree arg
= fold_build2 (MULT_EXPR
, type
, arg00
, arg10
);
7990 tree arglist
= tree_cons (NULL_TREE
, arg
,
7991 build_tree_list (NULL_TREE
,
7993 return build_function_call_expr (powfn
, arglist
);
7996 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
7997 if (operand_equal_p (arg00
, arg10
, 0))
7999 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
8000 tree arg
= fold_build2 (PLUS_EXPR
, type
, arg01
, arg11
);
8001 tree arglist
= tree_cons (NULL_TREE
, arg00
,
8002 build_tree_list (NULL_TREE
,
8004 return build_function_call_expr (powfn
, arglist
);
8008 /* Optimize tan(x)*cos(x) as sin(x). */
8009 if (((fcode0
== BUILT_IN_TAN
&& fcode1
== BUILT_IN_COS
)
8010 || (fcode0
== BUILT_IN_TANF
&& fcode1
== BUILT_IN_COSF
)
8011 || (fcode0
== BUILT_IN_TANL
&& fcode1
== BUILT_IN_COSL
)
8012 || (fcode0
== BUILT_IN_COS
&& fcode1
== BUILT_IN_TAN
)
8013 || (fcode0
== BUILT_IN_COSF
&& fcode1
== BUILT_IN_TANF
)
8014 || (fcode0
== BUILT_IN_COSL
&& fcode1
== BUILT_IN_TANL
))
8015 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0
, 1)),
8016 TREE_VALUE (TREE_OPERAND (arg1
, 1)), 0))
8018 tree sinfn
= mathfn_built_in (type
, BUILT_IN_SIN
);
8020 if (sinfn
!= NULL_TREE
)
8021 return build_function_call_expr (sinfn
,
8022 TREE_OPERAND (arg0
, 1));
8025 /* Optimize x*pow(x,c) as pow(x,c+1). */
8026 if (fcode1
== BUILT_IN_POW
8027 || fcode1
== BUILT_IN_POWF
8028 || fcode1
== BUILT_IN_POWL
)
8030 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
8031 tree arg11
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1
,
8033 if (TREE_CODE (arg11
) == REAL_CST
8034 && ! TREE_CONSTANT_OVERFLOW (arg11
)
8035 && operand_equal_p (arg0
, arg10
, 0))
8037 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0);
8041 c
= TREE_REAL_CST (arg11
);
8042 real_arithmetic (&c
, PLUS_EXPR
, &c
, &dconst1
);
8043 arg
= build_real (type
, c
);
8044 arglist
= build_tree_list (NULL_TREE
, arg
);
8045 arglist
= tree_cons (NULL_TREE
, arg0
, arglist
);
8046 return build_function_call_expr (powfn
, arglist
);
8050 /* Optimize pow(x,c)*x as pow(x,c+1). */
8051 if (fcode0
== BUILT_IN_POW
8052 || fcode0
== BUILT_IN_POWF
8053 || fcode0
== BUILT_IN_POWL
)
8055 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
8056 tree arg01
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0
,
8058 if (TREE_CODE (arg01
) == REAL_CST
8059 && ! TREE_CONSTANT_OVERFLOW (arg01
)
8060 && operand_equal_p (arg1
, arg00
, 0))
8062 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
8066 c
= TREE_REAL_CST (arg01
);
8067 real_arithmetic (&c
, PLUS_EXPR
, &c
, &dconst1
);
8068 arg
= build_real (type
, c
);
8069 arglist
= build_tree_list (NULL_TREE
, arg
);
8070 arglist
= tree_cons (NULL_TREE
, arg1
, arglist
);
8071 return build_function_call_expr (powfn
, arglist
);
8075 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
8077 && operand_equal_p (arg0
, arg1
, 0))
8079 tree powfn
= mathfn_built_in (type
, BUILT_IN_POW
);
8083 tree arg
= build_real (type
, dconst2
);
8084 tree arglist
= build_tree_list (NULL_TREE
, arg
);
8085 arglist
= tree_cons (NULL_TREE
, arg0
, arglist
);
8086 return build_function_call_expr (powfn
, arglist
);
8095 if (integer_all_onesp (arg1
))
8096 return omit_one_operand (type
, arg1
, arg0
);
8097 if (integer_zerop (arg1
))
8098 return non_lvalue (fold_convert (type
, arg0
));
8099 if (operand_equal_p (arg0
, arg1
, 0))
8100 return non_lvalue (fold_convert (type
, arg0
));
8103 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
8104 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
8106 t1
= build_int_cst (type
, -1);
8107 t1
= force_fit_type (t1
, 0, false, false);
8108 return omit_one_operand (type
, t1
, arg1
);
8112 if (TREE_CODE (arg1
) == BIT_NOT_EXPR
8113 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
8115 t1
= build_int_cst (type
, -1);
8116 t1
= force_fit_type (t1
, 0, false, false);
8117 return omit_one_operand (type
, t1
, arg0
);
8120 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
8121 if (t1
!= NULL_TREE
)
8124 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
8126 This results in more efficient code for machines without a NAND
8127 instruction. Combine will canonicalize to the first form
8128 which will allow use of NAND instructions provided by the
8129 backend if they exist. */
8130 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
8131 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
8133 return fold_build1 (BIT_NOT_EXPR
, type
,
8134 build2 (BIT_AND_EXPR
, type
,
8135 TREE_OPERAND (arg0
, 0),
8136 TREE_OPERAND (arg1
, 0)));
8139 /* See if this can be simplified into a rotate first. If that
8140 is unsuccessful continue in the association code. */
8144 if (integer_zerop (arg1
))
8145 return non_lvalue (fold_convert (type
, arg0
));
8146 if (integer_all_onesp (arg1
))
8147 return fold_build1 (BIT_NOT_EXPR
, type
, arg0
);
8148 if (operand_equal_p (arg0
, arg1
, 0))
8149 return omit_one_operand (type
, integer_zero_node
, arg0
);
8152 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
8153 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
8155 t1
= build_int_cst (type
, -1);
8156 t1
= force_fit_type (t1
, 0, false, false);
8157 return omit_one_operand (type
, t1
, arg1
);
8161 if (TREE_CODE (arg1
) == BIT_NOT_EXPR
8162 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
8164 t1
= build_int_cst (type
, -1);
8165 t1
= force_fit_type (t1
, 0, false, false);
8166 return omit_one_operand (type
, t1
, arg0
);
8169 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
8170 with a constant, and the two constants have no bits in common,
8171 we should treat this as a BIT_IOR_EXPR since this may produce more
8173 if (TREE_CODE (arg0
) == BIT_AND_EXPR
8174 && TREE_CODE (arg1
) == BIT_AND_EXPR
8175 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
8176 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
8177 && integer_zerop (const_binop (BIT_AND_EXPR
,
8178 TREE_OPERAND (arg0
, 1),
8179 TREE_OPERAND (arg1
, 1), 0)))
8181 code
= BIT_IOR_EXPR
;
8185 /* (X | Y) ^ X -> Y & ~ X*/
8186 if (TREE_CODE (arg0
) == BIT_IOR_EXPR
8187 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
8189 tree t2
= TREE_OPERAND (arg0
, 1);
8190 t1
= fold_build1 (BIT_NOT_EXPR
, TREE_TYPE (arg1
),
8192 t1
= fold_build2 (BIT_AND_EXPR
, type
, fold_convert (type
, t2
),
8193 fold_convert (type
, t1
));
8197 /* (Y | X) ^ X -> Y & ~ X*/
8198 if (TREE_CODE (arg0
) == BIT_IOR_EXPR
8199 && operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
8201 tree t2
= TREE_OPERAND (arg0
, 0);
8202 t1
= fold_build1 (BIT_NOT_EXPR
, TREE_TYPE (arg1
),
8204 t1
= fold_build2 (BIT_AND_EXPR
, type
, fold_convert (type
, t2
),
8205 fold_convert (type
, t1
));
8209 /* X ^ (X | Y) -> Y & ~ X*/
8210 if (TREE_CODE (arg1
) == BIT_IOR_EXPR
8211 && operand_equal_p (TREE_OPERAND (arg1
, 0), arg0
, 0))
8213 tree t2
= TREE_OPERAND (arg1
, 1);
8214 t1
= fold_build1 (BIT_NOT_EXPR
, TREE_TYPE (arg0
),
8216 t1
= fold_build2 (BIT_AND_EXPR
, type
, fold_convert (type
, t2
),
8217 fold_convert (type
, t1
));
8221 /* X ^ (Y | X) -> Y & ~ X*/
8222 if (TREE_CODE (arg1
) == BIT_IOR_EXPR
8223 && operand_equal_p (TREE_OPERAND (arg1
, 1), arg0
, 0))
8225 tree t2
= TREE_OPERAND (arg1
, 0);
8226 t1
= fold_build1 (BIT_NOT_EXPR
, TREE_TYPE (arg0
),
8228 t1
= fold_build2 (BIT_AND_EXPR
, type
, fold_convert (type
, t2
),
8229 fold_convert (type
, t1
));
8233 /* Convert ~X ^ ~Y to X ^ Y. */
8234 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
8235 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
8236 return fold_build2 (code
, type
,
8237 fold_convert (type
, TREE_OPERAND (arg0
, 0)),
8238 fold_convert (type
, TREE_OPERAND (arg1
, 0)));
8240 /* See if this can be simplified into a rotate first. If that
8241 is unsuccessful continue in the association code. */
8245 if (integer_all_onesp (arg1
))
8246 return non_lvalue (fold_convert (type
, arg0
));
8247 if (integer_zerop (arg1
))
8248 return omit_one_operand (type
, arg1
, arg0
);
8249 if (operand_equal_p (arg0
, arg1
, 0))
8250 return non_lvalue (fold_convert (type
, arg0
));
8252 /* ~X & X is always zero. */
8253 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
8254 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
8255 return omit_one_operand (type
, integer_zero_node
, arg1
);
8257 /* X & ~X is always zero. */
8258 if (TREE_CODE (arg1
) == BIT_NOT_EXPR
8259 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
8260 return omit_one_operand (type
, integer_zero_node
, arg0
);
8262 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
8263 if (t1
!= NULL_TREE
)
8265 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
8266 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) == NOP_EXPR
8267 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
8270 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)));
8272 if (prec
< BITS_PER_WORD
&& prec
< HOST_BITS_PER_WIDE_INT
8273 && (~TREE_INT_CST_LOW (arg1
)
8274 & (((HOST_WIDE_INT
) 1 << prec
) - 1)) == 0)
8275 return fold_convert (type
, TREE_OPERAND (arg0
, 0));
8278 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
8280 This results in more efficient code for machines without a NOR
8281 instruction. Combine will canonicalize to the first form
8282 which will allow use of NOR instructions provided by the
8283 backend if they exist. */
8284 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
8285 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
8287 return fold_build1 (BIT_NOT_EXPR
, type
,
8288 build2 (BIT_IOR_EXPR
, type
,
8289 TREE_OPERAND (arg0
, 0),
8290 TREE_OPERAND (arg1
, 0)));
8296 /* Don't touch a floating-point divide by zero unless the mode
8297 of the constant can represent infinity. */
8298 if (TREE_CODE (arg1
) == REAL_CST
8299 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1
)))
8300 && real_zerop (arg1
))
8303 /* Optimize A / A to 1.0 if we don't care about
8304 NaNs or Infinities. */
8305 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
)))
8306 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg0
)))
8307 && operand_equal_p (arg0
, arg1
, 0))
8309 tree r
= build_real (TREE_TYPE (arg0
), dconst1
);
8311 return omit_two_operands (type
, r
, arg0
, arg1
);
8314 /* (-A) / (-B) -> A / B */
8315 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& negate_expr_p (arg1
))
8316 return fold_build2 (RDIV_EXPR
, type
,
8317 TREE_OPERAND (arg0
, 0),
8318 negate_expr (arg1
));
8319 if (TREE_CODE (arg1
) == NEGATE_EXPR
&& negate_expr_p (arg0
))
8320 return fold_build2 (RDIV_EXPR
, type
,
8322 TREE_OPERAND (arg1
, 0));
8324 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
8325 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
8326 && real_onep (arg1
))
8327 return non_lvalue (fold_convert (type
, arg0
));
8329 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
8330 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
8331 && real_minus_onep (arg1
))
8332 return non_lvalue (fold_convert (type
, negate_expr (arg0
)));
8334 /* If ARG1 is a constant, we can convert this to a multiply by the
8335 reciprocal. This does not have the same rounding properties,
8336 so only do this if -funsafe-math-optimizations. We can actually
8337 always safely do it if ARG1 is a power of two, but it's hard to
8338 tell if it is or not in a portable manner. */
8339 if (TREE_CODE (arg1
) == REAL_CST
)
8341 if (flag_unsafe_math_optimizations
8342 && 0 != (tem
= const_binop (code
, build_real (type
, dconst1
),
8344 return fold_build2 (MULT_EXPR
, type
, arg0
, tem
);
8345 /* Find the reciprocal if optimizing and the result is exact. */
8349 r
= TREE_REAL_CST (arg1
);
8350 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0
)), &r
))
8352 tem
= build_real (type
, r
);
8353 return fold_build2 (MULT_EXPR
, type
,
8354 fold_convert (type
, arg0
), tem
);
8358 /* Convert A/B/C to A/(B*C). */
8359 if (flag_unsafe_math_optimizations
8360 && TREE_CODE (arg0
) == RDIV_EXPR
)
8361 return fold_build2 (RDIV_EXPR
, type
, TREE_OPERAND (arg0
, 0),
8362 fold_build2 (MULT_EXPR
, type
,
8363 TREE_OPERAND (arg0
, 1), arg1
));
8365 /* Convert A/(B/C) to (A/B)*C. */
8366 if (flag_unsafe_math_optimizations
8367 && TREE_CODE (arg1
) == RDIV_EXPR
)
8368 return fold_build2 (MULT_EXPR
, type
,
8369 fold_build2 (RDIV_EXPR
, type
, arg0
,
8370 TREE_OPERAND (arg1
, 0)),
8371 TREE_OPERAND (arg1
, 1));
8373 /* Convert C1/(X*C2) into (C1/C2)/X. */
8374 if (flag_unsafe_math_optimizations
8375 && TREE_CODE (arg1
) == MULT_EXPR
8376 && TREE_CODE (arg0
) == REAL_CST
8377 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == REAL_CST
)
8379 tree tem
= const_binop (RDIV_EXPR
, arg0
,
8380 TREE_OPERAND (arg1
, 1), 0);
8382 return fold_build2 (RDIV_EXPR
, type
, tem
,
8383 TREE_OPERAND (arg1
, 0));
8386 if (flag_unsafe_math_optimizations
)
8388 enum built_in_function fcode0
= builtin_mathfn_code (arg0
);
8389 enum built_in_function fcode1
= builtin_mathfn_code (arg1
);
8391 /* Optimize sin(x)/cos(x) as tan(x). */
8392 if (((fcode0
== BUILT_IN_SIN
&& fcode1
== BUILT_IN_COS
)
8393 || (fcode0
== BUILT_IN_SINF
&& fcode1
== BUILT_IN_COSF
)
8394 || (fcode0
== BUILT_IN_SINL
&& fcode1
== BUILT_IN_COSL
))
8395 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0
, 1)),
8396 TREE_VALUE (TREE_OPERAND (arg1
, 1)), 0))
8398 tree tanfn
= mathfn_built_in (type
, BUILT_IN_TAN
);
8400 if (tanfn
!= NULL_TREE
)
8401 return build_function_call_expr (tanfn
,
8402 TREE_OPERAND (arg0
, 1));
8405 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
8406 if (((fcode0
== BUILT_IN_COS
&& fcode1
== BUILT_IN_SIN
)
8407 || (fcode0
== BUILT_IN_COSF
&& fcode1
== BUILT_IN_SINF
)
8408 || (fcode0
== BUILT_IN_COSL
&& fcode1
== BUILT_IN_SINL
))
8409 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0
, 1)),
8410 TREE_VALUE (TREE_OPERAND (arg1
, 1)), 0))
8412 tree tanfn
= mathfn_built_in (type
, BUILT_IN_TAN
);
8414 if (tanfn
!= NULL_TREE
)
8416 tree tmp
= TREE_OPERAND (arg0
, 1);
8417 tmp
= build_function_call_expr (tanfn
, tmp
);
8418 return fold_build2 (RDIV_EXPR
, type
,
8419 build_real (type
, dconst1
), tmp
);
8423 /* Optimize sin(x)/tan(x) as cos(x) if we don't care about
8424 NaNs or Infinities. */
8425 if (((fcode0
== BUILT_IN_SIN
&& fcode1
== BUILT_IN_TAN
)
8426 || (fcode0
== BUILT_IN_SINF
&& fcode1
== BUILT_IN_TANF
)
8427 || (fcode0
== BUILT_IN_SINL
&& fcode1
== BUILT_IN_TANL
)))
8429 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
8430 tree arg01
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
8432 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00
)))
8433 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00
)))
8434 && operand_equal_p (arg00
, arg01
, 0))
8436 tree cosfn
= mathfn_built_in (type
, BUILT_IN_COS
);
8438 if (cosfn
!= NULL_TREE
)
8439 return build_function_call_expr (cosfn
,
8440 TREE_OPERAND (arg0
, 1));
8444 /* Optimize tan(x)/sin(x) as 1.0/cos(x) if we don't care about
8445 NaNs or Infinities. */
8446 if (((fcode0
== BUILT_IN_TAN
&& fcode1
== BUILT_IN_SIN
)
8447 || (fcode0
== BUILT_IN_TANF
&& fcode1
== BUILT_IN_SINF
)
8448 || (fcode0
== BUILT_IN_TANL
&& fcode1
== BUILT_IN_SINL
)))
8450 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
8451 tree arg01
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
8453 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00
)))
8454 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00
)))
8455 && operand_equal_p (arg00
, arg01
, 0))
8457 tree cosfn
= mathfn_built_in (type
, BUILT_IN_COS
);
8459 if (cosfn
!= NULL_TREE
)
8461 tree tmp
= TREE_OPERAND (arg0
, 1);
8462 tmp
= build_function_call_expr (cosfn
, tmp
);
8463 return fold_build2 (RDIV_EXPR
, type
,
8464 build_real (type
, dconst1
),
8470 /* Optimize pow(x,c)/x as pow(x,c-1). */
8471 if (fcode0
== BUILT_IN_POW
8472 || fcode0
== BUILT_IN_POWF
8473 || fcode0
== BUILT_IN_POWL
)
8475 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
8476 tree arg01
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0
, 1)));
8477 if (TREE_CODE (arg01
) == REAL_CST
8478 && ! TREE_CONSTANT_OVERFLOW (arg01
)
8479 && operand_equal_p (arg1
, arg00
, 0))
8481 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
8485 c
= TREE_REAL_CST (arg01
);
8486 real_arithmetic (&c
, MINUS_EXPR
, &c
, &dconst1
);
8487 arg
= build_real (type
, c
);
8488 arglist
= build_tree_list (NULL_TREE
, arg
);
8489 arglist
= tree_cons (NULL_TREE
, arg1
, arglist
);
8490 return build_function_call_expr (powfn
, arglist
);
8494 /* Optimize x/expN(y) into x*expN(-y). */
8495 if (BUILTIN_EXPONENT_P (fcode1
))
8497 tree expfn
= TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0);
8498 tree arg
= negate_expr (TREE_VALUE (TREE_OPERAND (arg1
, 1)));
8499 tree arglist
= build_tree_list (NULL_TREE
,
8500 fold_convert (type
, arg
));
8501 arg1
= build_function_call_expr (expfn
, arglist
);
8502 return fold_build2 (MULT_EXPR
, type
, arg0
, arg1
);
8505 /* Optimize x/pow(y,z) into x*pow(y,-z). */
8506 if (fcode1
== BUILT_IN_POW
8507 || fcode1
== BUILT_IN_POWF
8508 || fcode1
== BUILT_IN_POWL
)
8510 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0);
8511 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
8512 tree arg11
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1
, 1)));
8513 tree neg11
= fold_convert (type
, negate_expr (arg11
));
8514 tree arglist
= tree_cons(NULL_TREE
, arg10
,
8515 build_tree_list (NULL_TREE
, neg11
));
8516 arg1
= build_function_call_expr (powfn
, arglist
);
8517 return fold_build2 (MULT_EXPR
, type
, arg0
, arg1
);
8522 case TRUNC_DIV_EXPR
:
8523 case ROUND_DIV_EXPR
:
8524 case FLOOR_DIV_EXPR
:
8526 case EXACT_DIV_EXPR
:
8527 if (integer_onep (arg1
))
8528 return non_lvalue (fold_convert (type
, arg0
));
8529 if (integer_zerop (arg1
))
8532 if (!TYPE_UNSIGNED (type
)
8533 && TREE_CODE (arg1
) == INTEGER_CST
8534 && TREE_INT_CST_LOW (arg1
) == (unsigned HOST_WIDE_INT
) -1
8535 && TREE_INT_CST_HIGH (arg1
) == -1)
8536 return fold_convert (type
, negate_expr (arg0
));
8538 /* Convert -A / -B to A / B when the type is signed and overflow is
8540 if (!TYPE_UNSIGNED (type
) && !flag_wrapv
8541 && TREE_CODE (arg0
) == NEGATE_EXPR
8542 && negate_expr_p (arg1
))
8543 return fold_build2 (code
, type
, TREE_OPERAND (arg0
, 0),
8544 negate_expr (arg1
));
8545 if (!TYPE_UNSIGNED (type
) && !flag_wrapv
8546 && TREE_CODE (arg1
) == NEGATE_EXPR
8547 && negate_expr_p (arg0
))
8548 return fold_build2 (code
, type
, negate_expr (arg0
),
8549 TREE_OPERAND (arg1
, 0));
8551 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
8552 operation, EXACT_DIV_EXPR.
8554 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
8555 At one time others generated faster code, it's not clear if they do
8556 after the last round to changes to the DIV code in expmed.c. */
8557 if ((code
== CEIL_DIV_EXPR
|| code
== FLOOR_DIV_EXPR
)
8558 && multiple_of_p (type
, arg0
, arg1
))
8559 return fold_build2 (EXACT_DIV_EXPR
, type
, arg0
, arg1
);
8561 if (TREE_CODE (arg1
) == INTEGER_CST
8562 && 0 != (tem
= extract_muldiv (op0
, arg1
, code
, NULL_TREE
)))
8563 return fold_convert (type
, tem
);
8568 case FLOOR_MOD_EXPR
:
8569 case ROUND_MOD_EXPR
:
8570 case TRUNC_MOD_EXPR
:
8571 /* X % 1 is always zero, but be sure to preserve any side
8573 if (integer_onep (arg1
))
8574 return omit_one_operand (type
, integer_zero_node
, arg0
);
8576 /* X % 0, return X % 0 unchanged so that we can get the
8577 proper warnings and errors. */
8578 if (integer_zerop (arg1
))
8581 /* 0 % X is always zero, but be sure to preserve any side
8582 effects in X. Place this after checking for X == 0. */
8583 if (integer_zerop (arg0
))
8584 return omit_one_operand (type
, integer_zero_node
, arg1
);
8586 /* X % -1 is zero. */
8587 if (!TYPE_UNSIGNED (type
)
8588 && TREE_CODE (arg1
) == INTEGER_CST
8589 && TREE_INT_CST_LOW (arg1
) == (unsigned HOST_WIDE_INT
) -1
8590 && TREE_INT_CST_HIGH (arg1
) == -1)
8591 return omit_one_operand (type
, integer_zero_node
, arg0
);
8593 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
8594 i.e. "X % C" into "X & C2", if X and C are positive. */
8595 if ((code
== TRUNC_MOD_EXPR
|| code
== FLOOR_MOD_EXPR
)
8596 && (TYPE_UNSIGNED (type
) || tree_expr_nonnegative_p (arg0
))
8597 && integer_pow2p (arg1
) && tree_int_cst_sgn (arg1
) >= 0)
8599 unsigned HOST_WIDE_INT high
, low
;
8603 l
= tree_log2 (arg1
);
8604 if (l
>= HOST_BITS_PER_WIDE_INT
)
8606 high
= ((unsigned HOST_WIDE_INT
) 1
8607 << (l
- HOST_BITS_PER_WIDE_INT
)) - 1;
8613 low
= ((unsigned HOST_WIDE_INT
) 1 << l
) - 1;
8616 mask
= build_int_cst_wide (type
, low
, high
);
8617 return fold_build2 (BIT_AND_EXPR
, type
,
8618 fold_convert (type
, arg0
), mask
);
8621 /* X % -C is the same as X % C. */
8622 if (code
== TRUNC_MOD_EXPR
8623 && !TYPE_UNSIGNED (type
)
8624 && TREE_CODE (arg1
) == INTEGER_CST
8625 && !TREE_CONSTANT_OVERFLOW (arg1
)
8626 && TREE_INT_CST_HIGH (arg1
) < 0
8628 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
8629 && !sign_bit_p (arg1
, arg1
))
8630 return fold_build2 (code
, type
, fold_convert (type
, arg0
),
8631 fold_convert (type
, negate_expr (arg1
)));
8633 /* X % -Y is the same as X % Y. */
8634 if (code
== TRUNC_MOD_EXPR
8635 && !TYPE_UNSIGNED (type
)
8636 && TREE_CODE (arg1
) == NEGATE_EXPR
8638 return fold_build2 (code
, type
, fold_convert (type
, arg0
),
8639 fold_convert (type
, TREE_OPERAND (arg1
, 0)));
8641 if (TREE_CODE (arg1
) == INTEGER_CST
8642 && 0 != (tem
= extract_muldiv (op0
, arg1
, code
, NULL_TREE
)))
8643 return fold_convert (type
, tem
);
8649 if (integer_all_onesp (arg0
))
8650 return omit_one_operand (type
, arg0
, arg1
);
8654 /* Optimize -1 >> x for arithmetic right shifts. */
8655 if (integer_all_onesp (arg0
) && !TYPE_UNSIGNED (type
))
8656 return omit_one_operand (type
, arg0
, arg1
);
8657 /* ... fall through ... */
8661 if (integer_zerop (arg1
))
8662 return non_lvalue (fold_convert (type
, arg0
));
8663 if (integer_zerop (arg0
))
8664 return omit_one_operand (type
, arg0
, arg1
);
8666 /* Since negative shift count is not well-defined,
8667 don't try to compute it in the compiler. */
8668 if (TREE_CODE (arg1
) == INTEGER_CST
&& tree_int_cst_sgn (arg1
) < 0)
8671 /* Turn (a OP c1) OP c2 into a OP (c1+c2). */
8672 if (TREE_CODE (arg0
) == code
&& host_integerp (arg1
, false)
8673 && TREE_INT_CST_LOW (arg1
) < TYPE_PRECISION (type
)
8674 && host_integerp (TREE_OPERAND (arg0
, 1), false)
8675 && TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1)) < TYPE_PRECISION (type
))
8677 HOST_WIDE_INT low
= (TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1))
8678 + TREE_INT_CST_LOW (arg1
));
8680 /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
8681 being well defined. */
8682 if (low
>= TYPE_PRECISION (type
))
8684 if (code
== LROTATE_EXPR
|| code
== RROTATE_EXPR
)
8685 low
= low
% TYPE_PRECISION (type
);
8686 else if (TYPE_UNSIGNED (type
) || code
== LSHIFT_EXPR
)
8687 return build_int_cst (type
, 0);
8689 low
= TYPE_PRECISION (type
) - 1;
8692 return fold_build2 (code
, type
, TREE_OPERAND (arg0
, 0),
8693 build_int_cst (type
, low
));
8696 /* Transform (x >> c) << c into x & (-1<<c), or transform (x << c) >> c
8697 into x & ((unsigned)-1 >> c) for unsigned types. */
8698 if (((code
== LSHIFT_EXPR
&& TREE_CODE (arg0
) == RSHIFT_EXPR
)
8699 || (TYPE_UNSIGNED (type
)
8700 && code
== RSHIFT_EXPR
&& TREE_CODE (arg0
) == LSHIFT_EXPR
))
8701 && host_integerp (arg1
, false)
8702 && TREE_INT_CST_LOW (arg1
) < TYPE_PRECISION (type
)
8703 && host_integerp (TREE_OPERAND (arg0
, 1), false)
8704 && TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1)) < TYPE_PRECISION (type
))
8706 HOST_WIDE_INT low0
= TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1));
8707 HOST_WIDE_INT low1
= TREE_INT_CST_LOW (arg1
);
8713 arg00
= fold_convert (type
, TREE_OPERAND (arg0
, 0));
8715 lshift
= build_int_cst (type
, -1);
8716 lshift
= int_const_binop (code
, lshift
, arg1
, 0);
8718 return fold_build2 (BIT_AND_EXPR
, type
, arg00
, lshift
);
8722 /* Rewrite an LROTATE_EXPR by a constant into an
8723 RROTATE_EXPR by a new constant. */
8724 if (code
== LROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
)
8726 tree tem
= build_int_cst (NULL_TREE
,
8727 GET_MODE_BITSIZE (TYPE_MODE (type
)));
8728 tem
= fold_convert (TREE_TYPE (arg1
), tem
);
8729 tem
= const_binop (MINUS_EXPR
, tem
, arg1
, 0);
8730 return fold_build2 (RROTATE_EXPR
, type
, arg0
, tem
);
8733 /* If we have a rotate of a bit operation with the rotate count and
8734 the second operand of the bit operation both constant,
8735 permute the two operations. */
8736 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
8737 && (TREE_CODE (arg0
) == BIT_AND_EXPR
8738 || TREE_CODE (arg0
) == BIT_IOR_EXPR
8739 || TREE_CODE (arg0
) == BIT_XOR_EXPR
)
8740 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
8741 return fold_build2 (TREE_CODE (arg0
), type
,
8742 fold_build2 (code
, type
,
8743 TREE_OPERAND (arg0
, 0), arg1
),
8744 fold_build2 (code
, type
,
8745 TREE_OPERAND (arg0
, 1), arg1
));
8747 /* Two consecutive rotates adding up to the width of the mode can
8749 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
8750 && TREE_CODE (arg0
) == RROTATE_EXPR
8751 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
8752 && TREE_INT_CST_HIGH (arg1
) == 0
8753 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0
, 1)) == 0
8754 && ((TREE_INT_CST_LOW (arg1
)
8755 + TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1)))
8756 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type
))))
8757 return TREE_OPERAND (arg0
, 0);
8762 if (operand_equal_p (arg0
, arg1
, 0))
8763 return omit_one_operand (type
, arg0
, arg1
);
8764 if (INTEGRAL_TYPE_P (type
)
8765 && operand_equal_p (arg1
, TYPE_MIN_VALUE (type
), OEP_ONLY_CONST
))
8766 return omit_one_operand (type
, arg1
, arg0
);
8767 tem
= fold_minmax (MIN_EXPR
, type
, arg0
, arg1
);
8773 if (operand_equal_p (arg0
, arg1
, 0))
8774 return omit_one_operand (type
, arg0
, arg1
);
8775 if (INTEGRAL_TYPE_P (type
)
8776 && TYPE_MAX_VALUE (type
)
8777 && operand_equal_p (arg1
, TYPE_MAX_VALUE (type
), OEP_ONLY_CONST
))
8778 return omit_one_operand (type
, arg1
, arg0
);
8779 tem
= fold_minmax (MAX_EXPR
, type
, arg0
, arg1
);
8784 case TRUTH_ANDIF_EXPR
:
8785 /* Note that the operands of this must be ints
8786 and their values must be 0 or 1.
8787 ("true" is a fixed value perhaps depending on the language.) */
8788 /* If first arg is constant zero, return it. */
8789 if (integer_zerop (arg0
))
8790 return fold_convert (type
, arg0
);
8791 case TRUTH_AND_EXPR
:
8792 /* If either arg is constant true, drop it. */
8793 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
8794 return non_lvalue (fold_convert (type
, arg1
));
8795 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
)
8796 /* Preserve sequence points. */
8797 && (code
!= TRUTH_ANDIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
8798 return non_lvalue (fold_convert (type
, arg0
));
8799 /* If second arg is constant zero, result is zero, but first arg
8800 must be evaluated. */
8801 if (integer_zerop (arg1
))
8802 return omit_one_operand (type
, arg1
, arg0
);
8803 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
8804 case will be handled here. */
8805 if (integer_zerop (arg0
))
8806 return omit_one_operand (type
, arg0
, arg1
);
8808 /* !X && X is always false. */
8809 if (TREE_CODE (arg0
) == TRUTH_NOT_EXPR
8810 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
8811 return omit_one_operand (type
, integer_zero_node
, arg1
);
8812 /* X && !X is always false. */
8813 if (TREE_CODE (arg1
) == TRUTH_NOT_EXPR
8814 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
8815 return omit_one_operand (type
, integer_zero_node
, arg0
);
8817 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
8818 means A >= Y && A != MAX, but in this case we know that
8821 if (!TREE_SIDE_EFFECTS (arg0
)
8822 && !TREE_SIDE_EFFECTS (arg1
))
8824 tem
= fold_to_nonsharp_ineq_using_bound (arg0
, arg1
);
8825 if (tem
&& !operand_equal_p (tem
, arg0
, 0))
8826 return fold_build2 (code
, type
, tem
, arg1
);
8828 tem
= fold_to_nonsharp_ineq_using_bound (arg1
, arg0
);
8829 if (tem
&& !operand_equal_p (tem
, arg1
, 0))
8830 return fold_build2 (code
, type
, arg0
, tem
);
8834 /* We only do these simplifications if we are optimizing. */
8838 /* Check for things like (A || B) && (A || C). We can convert this
8839 to A || (B && C). Note that either operator can be any of the four
8840 truth and/or operations and the transformation will still be
8841 valid. Also note that we only care about order for the
8842 ANDIF and ORIF operators. If B contains side effects, this
8843 might change the truth-value of A. */
8844 if (TREE_CODE (arg0
) == TREE_CODE (arg1
)
8845 && (TREE_CODE (arg0
) == TRUTH_ANDIF_EXPR
8846 || TREE_CODE (arg0
) == TRUTH_ORIF_EXPR
8847 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
8848 || TREE_CODE (arg0
) == TRUTH_OR_EXPR
)
8849 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0
, 1)))
8851 tree a00
= TREE_OPERAND (arg0
, 0);
8852 tree a01
= TREE_OPERAND (arg0
, 1);
8853 tree a10
= TREE_OPERAND (arg1
, 0);
8854 tree a11
= TREE_OPERAND (arg1
, 1);
8855 int commutative
= ((TREE_CODE (arg0
) == TRUTH_OR_EXPR
8856 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
)
8857 && (code
== TRUTH_AND_EXPR
8858 || code
== TRUTH_OR_EXPR
));
8860 if (operand_equal_p (a00
, a10
, 0))
8861 return fold_build2 (TREE_CODE (arg0
), type
, a00
,
8862 fold_build2 (code
, type
, a01
, a11
));
8863 else if (commutative
&& operand_equal_p (a00
, a11
, 0))
8864 return fold_build2 (TREE_CODE (arg0
), type
, a00
,
8865 fold_build2 (code
, type
, a01
, a10
));
8866 else if (commutative
&& operand_equal_p (a01
, a10
, 0))
8867 return fold_build2 (TREE_CODE (arg0
), type
, a01
,
8868 fold_build2 (code
, type
, a00
, a11
));
8870 /* This case if tricky because we must either have commutative
8871 operators or else A10 must not have side-effects. */
8873 else if ((commutative
|| ! TREE_SIDE_EFFECTS (a10
))
8874 && operand_equal_p (a01
, a11
, 0))
8875 return fold_build2 (TREE_CODE (arg0
), type
,
8876 fold_build2 (code
, type
, a00
, a10
),
8880 /* See if we can build a range comparison. */
8881 if (0 != (tem
= fold_range_test (code
, type
, op0
, op1
)))
8884 /* Check for the possibility of merging component references. If our
8885 lhs is another similar operation, try to merge its rhs with our
8886 rhs. Then try to merge our lhs and rhs. */
8887 if (TREE_CODE (arg0
) == code
8888 && 0 != (tem
= fold_truthop (code
, type
,
8889 TREE_OPERAND (arg0
, 1), arg1
)))
8890 return fold_build2 (code
, type
, TREE_OPERAND (arg0
, 0), tem
);
8892 if ((tem
= fold_truthop (code
, type
, arg0
, arg1
)) != 0)
8897 case TRUTH_ORIF_EXPR
:
8898 /* Note that the operands of this must be ints
8899 and their values must be 0 or true.
8900 ("true" is a fixed value perhaps depending on the language.) */
8901 /* If first arg is constant true, return it. */
8902 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
8903 return fold_convert (type
, arg0
);
8905 /* If either arg is constant zero, drop it. */
8906 if (TREE_CODE (arg0
) == INTEGER_CST
&& integer_zerop (arg0
))
8907 return non_lvalue (fold_convert (type
, arg1
));
8908 if (TREE_CODE (arg1
) == INTEGER_CST
&& integer_zerop (arg1
)
8909 /* Preserve sequence points. */
8910 && (code
!= TRUTH_ORIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
8911 return non_lvalue (fold_convert (type
, arg0
));
8912 /* If second arg is constant true, result is true, but we must
8913 evaluate first arg. */
8914 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
))
8915 return omit_one_operand (type
, arg1
, arg0
);
8916 /* Likewise for first arg, but note this only occurs here for
8918 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
8919 return omit_one_operand (type
, arg0
, arg1
);
8921 /* !X || X is always true. */
8922 if (TREE_CODE (arg0
) == TRUTH_NOT_EXPR
8923 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
8924 return omit_one_operand (type
, integer_one_node
, arg1
);
8925 /* X || !X is always true. */
8926 if (TREE_CODE (arg1
) == TRUTH_NOT_EXPR
8927 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
8928 return omit_one_operand (type
, integer_one_node
, arg0
);
8932 case TRUTH_XOR_EXPR
:
8933 /* If the second arg is constant zero, drop it. */
8934 if (integer_zerop (arg1
))
8935 return non_lvalue (fold_convert (type
, arg0
));
8936 /* If the second arg is constant true, this is a logical inversion. */
8937 if (integer_onep (arg1
))
8939 /* Only call invert_truthvalue if operand is a truth value. */
8940 if (TREE_CODE (TREE_TYPE (arg0
)) != BOOLEAN_TYPE
)
8941 tem
= fold_build1 (TRUTH_NOT_EXPR
, TREE_TYPE (arg0
), arg0
);
8943 tem
= invert_truthvalue (arg0
);
8944 return non_lvalue (fold_convert (type
, tem
));
8946 /* Identical arguments cancel to zero. */
8947 if (operand_equal_p (arg0
, arg1
, 0))
8948 return omit_one_operand (type
, integer_zero_node
, arg0
);
8950 /* !X ^ X is always true. */
8951 if (TREE_CODE (arg0
) == TRUTH_NOT_EXPR
8952 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
8953 return omit_one_operand (type
, integer_one_node
, arg1
);
8955 /* X ^ !X is always true. */
8956 if (TREE_CODE (arg1
) == TRUTH_NOT_EXPR
8957 && operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
8958 return omit_one_operand (type
, integer_one_node
, arg0
);
8968 /* If one arg is a real or integer constant, put it last. */
8969 if (tree_swap_operands_p (arg0
, arg1
, true))
8970 return fold_build2 (swap_tree_comparison (code
), type
, op1
, op0
);
8972 /* ~a != C becomes a != ~C where C is a constant. Likewise for ==. */
8973 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
8974 && (code
== NE_EXPR
|| code
== EQ_EXPR
))
8975 return fold_build2 (code
, type
, TREE_OPERAND (arg0
, 0),
8976 fold_build1 (BIT_NOT_EXPR
, TREE_TYPE (arg1
),
8979 /* bool_var != 0 becomes bool_var. */
8980 if (TREE_CODE (TREE_TYPE (arg0
)) == BOOLEAN_TYPE
&& integer_zerop (arg1
)
8982 return non_lvalue (fold_convert (type
, arg0
));
8984 /* bool_var == 1 becomes bool_var. */
8985 if (TREE_CODE (TREE_TYPE (arg0
)) == BOOLEAN_TYPE
&& integer_onep (arg1
)
8987 return non_lvalue (fold_convert (type
, arg0
));
8989 /* bool_var != 1 becomes !bool_var. */
8990 if (TREE_CODE (TREE_TYPE (arg0
)) == BOOLEAN_TYPE
&& integer_onep (arg1
)
8992 return fold_build1 (TRUTH_NOT_EXPR
, type
, arg0
);
8994 /* bool_var == 0 becomes !bool_var. */
8995 if (TREE_CODE (TREE_TYPE (arg0
)) == BOOLEAN_TYPE
&& integer_zerop (arg1
)
8997 return fold_build1 (TRUTH_NOT_EXPR
, type
, arg0
);
8999 /* If this is an equality comparison of the address of a non-weak
9000 object against zero, then we know the result. */
9001 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
9002 && TREE_CODE (arg0
) == ADDR_EXPR
9003 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0
, 0))
9004 && ! DECL_WEAK (TREE_OPERAND (arg0
, 0))
9005 && integer_zerop (arg1
))
9006 return constant_boolean_node (code
!= EQ_EXPR
, type
);
9008 /* If this is an equality comparison of the address of two non-weak,
9009 unaliased symbols neither of which are extern (since we do not
9010 have access to attributes for externs), then we know the result. */
9011 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
9012 && TREE_CODE (arg0
) == ADDR_EXPR
9013 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0
, 0))
9014 && ! DECL_WEAK (TREE_OPERAND (arg0
, 0))
9015 && ! lookup_attribute ("alias",
9016 DECL_ATTRIBUTES (TREE_OPERAND (arg0
, 0)))
9017 && ! DECL_EXTERNAL (TREE_OPERAND (arg0
, 0))
9018 && TREE_CODE (arg1
) == ADDR_EXPR
9019 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg1
, 0))
9020 && ! DECL_WEAK (TREE_OPERAND (arg1
, 0))
9021 && ! lookup_attribute ("alias",
9022 DECL_ATTRIBUTES (TREE_OPERAND (arg1
, 0)))
9023 && ! DECL_EXTERNAL (TREE_OPERAND (arg1
, 0)))
9025 /* We know that we're looking at the address of two
9026 non-weak, unaliased, static _DECL nodes.
9028 It is both wasteful and incorrect to call operand_equal_p
9029 to compare the two ADDR_EXPR nodes. It is wasteful in that
9030 all we need to do is test pointer equality for the arguments
9031 to the two ADDR_EXPR nodes. It is incorrect to use
9032 operand_equal_p as that function is NOT equivalent to a
9033 C equality test. It can in fact return false for two
9034 objects which would test as equal using the C equality
9036 bool equal
= TREE_OPERAND (arg0
, 0) == TREE_OPERAND (arg1
, 0);
9037 return constant_boolean_node (equal
9038 ? code
== EQ_EXPR
: code
!= EQ_EXPR
,
9042 /* If this is a comparison of two exprs that look like an
9043 ARRAY_REF of the same object, then we can fold this to a
9044 comparison of the two offsets. */
9045 if (TREE_CODE_CLASS (code
) == tcc_comparison
)
9047 tree base0
, offset0
, base1
, offset1
;
9049 if (extract_array_ref (arg0
, &base0
, &offset0
)
9050 && extract_array_ref (arg1
, &base1
, &offset1
)
9051 && operand_equal_p (base0
, base1
, 0))
9053 /* Handle no offsets on both sides specially. */
9054 if (offset0
== NULL_TREE
9055 && offset1
== NULL_TREE
)
9056 return fold_build2 (code
, type
, integer_zero_node
,
9059 if (!offset0
|| !offset1
9060 || TREE_TYPE (offset0
) == TREE_TYPE (offset1
))
9062 if (offset0
== NULL_TREE
)
9063 offset0
= build_int_cst (TREE_TYPE (offset1
), 0);
9064 if (offset1
== NULL_TREE
)
9065 offset1
= build_int_cst (TREE_TYPE (offset0
), 0);
9066 return fold_build2 (code
, type
, offset0
, offset1
);
9071 /* Transform comparisons of the form X +- C CMP X. */
9072 if ((code
!= EQ_EXPR
&& code
!= NE_EXPR
)
9073 && (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
9074 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0)
9075 && ((TREE_CODE (TREE_OPERAND (arg0
, 1)) == REAL_CST
9076 && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
))))
9077 || (TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
9078 && !TYPE_UNSIGNED (TREE_TYPE (arg1
))
9079 && !(flag_wrapv
|| flag_trapv
))))
9081 tree arg01
= TREE_OPERAND (arg0
, 1);
9082 enum tree_code code0
= TREE_CODE (arg0
);
9085 if (TREE_CODE (arg01
) == REAL_CST
)
9086 is_positive
= REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01
)) ? -1 : 1;
9088 is_positive
= tree_int_cst_sgn (arg01
);
9090 /* (X - c) > X becomes false. */
9092 && ((code0
== MINUS_EXPR
&& is_positive
>= 0)
9093 || (code0
== PLUS_EXPR
&& is_positive
<= 0)))
9094 return constant_boolean_node (0, type
);
9096 /* Likewise (X + c) < X becomes false. */
9098 && ((code0
== PLUS_EXPR
&& is_positive
>= 0)
9099 || (code0
== MINUS_EXPR
&& is_positive
<= 0)))
9100 return constant_boolean_node (0, type
);
9102 /* Convert (X - c) <= X to true. */
9103 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
)))
9105 && ((code0
== MINUS_EXPR
&& is_positive
>= 0)
9106 || (code0
== PLUS_EXPR
&& is_positive
<= 0)))
9107 return constant_boolean_node (1, type
);
9109 /* Convert (X + c) >= X to true. */
9110 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
)))
9112 && ((code0
== PLUS_EXPR
&& is_positive
>= 0)
9113 || (code0
== MINUS_EXPR
&& is_positive
<= 0)))
9114 return constant_boolean_node (1, type
);
9116 if (TREE_CODE (arg01
) == INTEGER_CST
)
9118 /* Convert X + c > X and X - c < X to true for integers. */
9120 && ((code0
== PLUS_EXPR
&& is_positive
> 0)
9121 || (code0
== MINUS_EXPR
&& is_positive
< 0)))
9122 return constant_boolean_node (1, type
);
9125 && ((code0
== MINUS_EXPR
&& is_positive
> 0)
9126 || (code0
== PLUS_EXPR
&& is_positive
< 0)))
9127 return constant_boolean_node (1, type
);
9129 /* Convert X + c <= X and X - c >= X to false for integers. */
9131 && ((code0
== PLUS_EXPR
&& is_positive
> 0)
9132 || (code0
== MINUS_EXPR
&& is_positive
< 0)))
9133 return constant_boolean_node (0, type
);
9136 && ((code0
== MINUS_EXPR
&& is_positive
> 0)
9137 || (code0
== PLUS_EXPR
&& is_positive
< 0)))
9138 return constant_boolean_node (0, type
);
9142 /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */
9143 if ((TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
9144 && (TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
9145 && !TREE_OVERFLOW (TREE_OPERAND (arg0
, 1))
9146 && !TYPE_UNSIGNED (TREE_TYPE (arg1
))
9147 && !(flag_wrapv
|| flag_trapv
))
9148 && (TREE_CODE (arg1
) == INTEGER_CST
9149 && !TREE_OVERFLOW (arg1
)))
9151 tree const1
= TREE_OPERAND (arg0
, 1);
9153 tree variable
= TREE_OPERAND (arg0
, 0);
9156 lhs_add
= TREE_CODE (arg0
) != PLUS_EXPR
;
9158 lhs
= fold_build2 (lhs_add
? PLUS_EXPR
: MINUS_EXPR
,
9159 TREE_TYPE (arg1
), const2
, const1
);
9160 if (TREE_CODE (lhs
) == TREE_CODE (arg1
)
9161 && (TREE_CODE (lhs
) != INTEGER_CST
9162 || !TREE_OVERFLOW (lhs
)))
9163 return fold_build2 (code
, type
, variable
, lhs
);
9166 if (FLOAT_TYPE_P (TREE_TYPE (arg0
)))
9168 tree targ0
= strip_float_extensions (arg0
);
9169 tree targ1
= strip_float_extensions (arg1
);
9170 tree newtype
= TREE_TYPE (targ0
);
9172 if (TYPE_PRECISION (TREE_TYPE (targ1
)) > TYPE_PRECISION (newtype
))
9173 newtype
= TREE_TYPE (targ1
);
9175 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
9176 if (TYPE_PRECISION (newtype
) < TYPE_PRECISION (TREE_TYPE (arg0
)))
9177 return fold_build2 (code
, type
, fold_convert (newtype
, targ0
),
9178 fold_convert (newtype
, targ1
));
9180 /* (-a) CMP (-b) -> b CMP a */
9181 if (TREE_CODE (arg0
) == NEGATE_EXPR
9182 && TREE_CODE (arg1
) == NEGATE_EXPR
)
9183 return fold_build2 (code
, type
, TREE_OPERAND (arg1
, 0),
9184 TREE_OPERAND (arg0
, 0));
9186 if (TREE_CODE (arg1
) == REAL_CST
)
9188 REAL_VALUE_TYPE cst
;
9189 cst
= TREE_REAL_CST (arg1
);
9191 /* (-a) CMP CST -> a swap(CMP) (-CST) */
9192 if (TREE_CODE (arg0
) == NEGATE_EXPR
)
9194 fold_build2 (swap_tree_comparison (code
), type
,
9195 TREE_OPERAND (arg0
, 0),
9196 build_real (TREE_TYPE (arg1
),
9197 REAL_VALUE_NEGATE (cst
)));
9199 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
9200 /* a CMP (-0) -> a CMP 0 */
9201 if (REAL_VALUE_MINUS_ZERO (cst
))
9202 return fold_build2 (code
, type
, arg0
,
9203 build_real (TREE_TYPE (arg1
), dconst0
));
9205 /* x != NaN is always true, other ops are always false. */
9206 if (REAL_VALUE_ISNAN (cst
)
9207 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1
))))
9209 tem
= (code
== NE_EXPR
) ? integer_one_node
: integer_zero_node
;
9210 return omit_one_operand (type
, tem
, arg0
);
9213 /* Fold comparisons against infinity. */
9214 if (REAL_VALUE_ISINF (cst
))
9216 tem
= fold_inf_compare (code
, type
, arg0
, arg1
);
9217 if (tem
!= NULL_TREE
)
9222 /* If this is a comparison of a real constant with a PLUS_EXPR
9223 or a MINUS_EXPR of a real constant, we can convert it into a
9224 comparison with a revised real constant as long as no overflow
9225 occurs when unsafe_math_optimizations are enabled. */
9226 if (flag_unsafe_math_optimizations
9227 && TREE_CODE (arg1
) == REAL_CST
9228 && (TREE_CODE (arg0
) == PLUS_EXPR
9229 || TREE_CODE (arg0
) == MINUS_EXPR
)
9230 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == REAL_CST
9231 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
9232 ? MINUS_EXPR
: PLUS_EXPR
,
9233 arg1
, TREE_OPERAND (arg0
, 1), 0))
9234 && ! TREE_CONSTANT_OVERFLOW (tem
))
9235 return fold_build2 (code
, type
, TREE_OPERAND (arg0
, 0), tem
);
9237 /* Likewise, we can simplify a comparison of a real constant with
9238 a MINUS_EXPR whose first operand is also a real constant, i.e.
9239 (c1 - x) < c2 becomes x > c1-c2. */
9240 if (flag_unsafe_math_optimizations
9241 && TREE_CODE (arg1
) == REAL_CST
9242 && TREE_CODE (arg0
) == MINUS_EXPR
9243 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == REAL_CST
9244 && 0 != (tem
= const_binop (MINUS_EXPR
, TREE_OPERAND (arg0
, 0),
9246 && ! TREE_CONSTANT_OVERFLOW (tem
))
9247 return fold_build2 (swap_tree_comparison (code
), type
,
9248 TREE_OPERAND (arg0
, 1), tem
);
9250 /* Fold comparisons against built-in math functions. */
9251 if (TREE_CODE (arg1
) == REAL_CST
9252 && flag_unsafe_math_optimizations
9253 && ! flag_errno_math
)
9255 enum built_in_function fcode
= builtin_mathfn_code (arg0
);
9257 if (fcode
!= END_BUILTINS
)
9259 tem
= fold_mathfn_compare (fcode
, code
, type
, arg0
, arg1
);
9260 if (tem
!= NULL_TREE
)
9266 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
9267 if (TREE_CONSTANT (arg1
)
9268 && (TREE_CODE (arg0
) == POSTINCREMENT_EXPR
9269 || TREE_CODE (arg0
) == POSTDECREMENT_EXPR
)
9270 /* This optimization is invalid for ordered comparisons
9271 if CONST+INCR overflows or if foo+incr might overflow.
9272 This optimization is invalid for floating point due to rounding.
9273 For pointer types we assume overflow doesn't happen. */
9274 && (POINTER_TYPE_P (TREE_TYPE (arg0
))
9275 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
9276 && (code
== EQ_EXPR
|| code
== NE_EXPR
))))
9278 tree varop
, newconst
;
9280 if (TREE_CODE (arg0
) == POSTINCREMENT_EXPR
)
9282 newconst
= fold_build2 (PLUS_EXPR
, TREE_TYPE (arg0
),
9283 arg1
, TREE_OPERAND (arg0
, 1));
9284 varop
= build2 (PREINCREMENT_EXPR
, TREE_TYPE (arg0
),
9285 TREE_OPERAND (arg0
, 0),
9286 TREE_OPERAND (arg0
, 1));
9290 newconst
= fold_build2 (MINUS_EXPR
, TREE_TYPE (arg0
),
9291 arg1
, TREE_OPERAND (arg0
, 1));
9292 varop
= build2 (PREDECREMENT_EXPR
, TREE_TYPE (arg0
),
9293 TREE_OPERAND (arg0
, 0),
9294 TREE_OPERAND (arg0
, 1));
9298 /* If VAROP is a reference to a bitfield, we must mask
9299 the constant by the width of the field. */
9300 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
9301 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop
, 0), 1))
9302 && host_integerp (DECL_SIZE (TREE_OPERAND
9303 (TREE_OPERAND (varop
, 0), 1)), 1))
9305 tree fielddecl
= TREE_OPERAND (TREE_OPERAND (varop
, 0), 1);
9306 HOST_WIDE_INT size
= tree_low_cst (DECL_SIZE (fielddecl
), 1);
9307 tree folded_compare
, shift
;
9309 /* First check whether the comparison would come out
9310 always the same. If we don't do that we would
9311 change the meaning with the masking. */
9312 folded_compare
= fold_build2 (code
, type
,
9313 TREE_OPERAND (varop
, 0), arg1
);
9314 if (integer_zerop (folded_compare
)
9315 || integer_onep (folded_compare
))
9316 return omit_one_operand (type
, folded_compare
, varop
);
9318 shift
= build_int_cst (NULL_TREE
,
9319 TYPE_PRECISION (TREE_TYPE (varop
)) - size
);
9320 shift
= fold_convert (TREE_TYPE (varop
), shift
);
9321 newconst
= fold_build2 (LSHIFT_EXPR
, TREE_TYPE (varop
),
9323 newconst
= fold_build2 (RSHIFT_EXPR
, TREE_TYPE (varop
),
9327 return fold_build2 (code
, type
, varop
, newconst
);
9330 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
9331 This transformation affects the cases which are handled in later
9332 optimizations involving comparisons with non-negative constants. */
9333 if (TREE_CODE (arg1
) == INTEGER_CST
9334 && TREE_CODE (arg0
) != INTEGER_CST
9335 && tree_int_cst_sgn (arg1
) > 0)
9340 arg1
= const_binop (MINUS_EXPR
, arg1
,
9341 build_int_cst (TREE_TYPE (arg1
), 1), 0);
9342 return fold_build2 (GT_EXPR
, type
, arg0
,
9343 fold_convert (TREE_TYPE (arg0
), arg1
));
9346 arg1
= const_binop (MINUS_EXPR
, arg1
,
9347 build_int_cst (TREE_TYPE (arg1
), 1), 0);
9348 return fold_build2 (LE_EXPR
, type
, arg0
,
9349 fold_convert (TREE_TYPE (arg0
), arg1
));
9356 /* Comparisons with the highest or lowest possible integer of
9357 the specified size will have known values. */
9359 int width
= GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1
)));
9361 if (TREE_CODE (arg1
) == INTEGER_CST
9362 && ! TREE_CONSTANT_OVERFLOW (arg1
)
9363 && width
<= 2 * HOST_BITS_PER_WIDE_INT
9364 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
9365 || POINTER_TYPE_P (TREE_TYPE (arg1
))))
9367 HOST_WIDE_INT signed_max_hi
;
9368 unsigned HOST_WIDE_INT signed_max_lo
;
9369 unsigned HOST_WIDE_INT max_hi
, max_lo
, min_hi
, min_lo
;
9371 if (width
<= HOST_BITS_PER_WIDE_INT
)
9373 signed_max_lo
= ((unsigned HOST_WIDE_INT
) 1 << (width
- 1))
9378 if (TYPE_UNSIGNED (TREE_TYPE (arg1
)))
9380 max_lo
= ((unsigned HOST_WIDE_INT
) 2 << (width
- 1)) - 1;
9386 max_lo
= signed_max_lo
;
9387 min_lo
= ((unsigned HOST_WIDE_INT
) -1 << (width
- 1));
9393 width
-= HOST_BITS_PER_WIDE_INT
;
9395 signed_max_hi
= ((unsigned HOST_WIDE_INT
) 1 << (width
- 1))
9400 if (TYPE_UNSIGNED (TREE_TYPE (arg1
)))
9402 max_hi
= ((unsigned HOST_WIDE_INT
) 2 << (width
- 1)) - 1;
9407 max_hi
= signed_max_hi
;
9408 min_hi
= ((unsigned HOST_WIDE_INT
) -1 << (width
- 1));
9412 if ((unsigned HOST_WIDE_INT
) TREE_INT_CST_HIGH (arg1
) == max_hi
9413 && TREE_INT_CST_LOW (arg1
) == max_lo
)
9417 return omit_one_operand (type
, integer_zero_node
, arg0
);
9420 return fold_build2 (EQ_EXPR
, type
, arg0
, arg1
);
9423 return omit_one_operand (type
, integer_one_node
, arg0
);
9426 return fold_build2 (NE_EXPR
, type
, arg0
, arg1
);
9428 /* The GE_EXPR and LT_EXPR cases above are not normally
9429 reached because of previous transformations. */
9434 else if ((unsigned HOST_WIDE_INT
) TREE_INT_CST_HIGH (arg1
)
9436 && TREE_INT_CST_LOW (arg1
) == max_lo
- 1)
9440 arg1
= const_binop (PLUS_EXPR
, arg1
, integer_one_node
, 0);
9441 return fold_build2 (EQ_EXPR
, type
, arg0
, arg1
);
9443 arg1
= const_binop (PLUS_EXPR
, arg1
, integer_one_node
, 0);
9444 return fold_build2 (NE_EXPR
, type
, arg0
, arg1
);
9448 else if ((unsigned HOST_WIDE_INT
) TREE_INT_CST_HIGH (arg1
)
9450 && TREE_INT_CST_LOW (arg1
) == min_lo
)
9454 return omit_one_operand (type
, integer_zero_node
, arg0
);
9457 return fold_build2 (EQ_EXPR
, type
, arg0
, arg1
);
9460 return omit_one_operand (type
, integer_one_node
, arg0
);
9463 return fold_build2 (NE_EXPR
, type
, op0
, op1
);
9468 else if ((unsigned HOST_WIDE_INT
) TREE_INT_CST_HIGH (arg1
)
9470 && TREE_INT_CST_LOW (arg1
) == min_lo
+ 1)
9474 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
9475 return fold_build2 (NE_EXPR
, type
, arg0
, arg1
);
9477 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
9478 return fold_build2 (EQ_EXPR
, type
, arg0
, arg1
);
9483 else if (!in_gimple_form
9484 && TREE_INT_CST_HIGH (arg1
) == signed_max_hi
9485 && TREE_INT_CST_LOW (arg1
) == signed_max_lo
9486 && TYPE_UNSIGNED (TREE_TYPE (arg1
))
9487 /* signed_type does not work on pointer types. */
9488 && INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
9490 /* The following case also applies to X < signed_max+1
9491 and X >= signed_max+1 because previous transformations. */
9492 if (code
== LE_EXPR
|| code
== GT_EXPR
)
9495 st0
= lang_hooks
.types
.signed_type (TREE_TYPE (arg0
));
9496 st1
= lang_hooks
.types
.signed_type (TREE_TYPE (arg1
));
9497 return fold_build2 (code
== LE_EXPR
? GE_EXPR
: LT_EXPR
,
9498 type
, fold_convert (st0
, arg0
),
9499 build_int_cst (st1
, 0));
9505 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
9506 a MINUS_EXPR of a constant, we can convert it into a comparison with
9507 a revised constant as long as no overflow occurs. */
9508 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
9509 && TREE_CODE (arg1
) == INTEGER_CST
9510 && (TREE_CODE (arg0
) == PLUS_EXPR
9511 || TREE_CODE (arg0
) == MINUS_EXPR
)
9512 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
9513 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
9514 ? MINUS_EXPR
: PLUS_EXPR
,
9515 arg1
, TREE_OPERAND (arg0
, 1), 0))
9516 && ! TREE_CONSTANT_OVERFLOW (tem
))
9517 return fold_build2 (code
, type
, TREE_OPERAND (arg0
, 0), tem
);
9519 /* Similarly for a NEGATE_EXPR. */
9520 else if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
9521 && TREE_CODE (arg0
) == NEGATE_EXPR
9522 && TREE_CODE (arg1
) == INTEGER_CST
9523 && 0 != (tem
= negate_expr (arg1
))
9524 && TREE_CODE (tem
) == INTEGER_CST
9525 && ! TREE_CONSTANT_OVERFLOW (tem
))
9526 return fold_build2 (code
, type
, TREE_OPERAND (arg0
, 0), tem
);
9528 /* If we have X - Y == 0, we can convert that to X == Y and similarly
9529 for !=. Don't do this for ordered comparisons due to overflow. */
9530 else if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
9531 && integer_zerop (arg1
) && TREE_CODE (arg0
) == MINUS_EXPR
)
9532 return fold_build2 (code
, type
,
9533 TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg0
, 1));
9535 else if (TREE_CODE (TREE_TYPE (arg0
)) == INTEGER_TYPE
9536 && (TREE_CODE (arg0
) == NOP_EXPR
9537 || TREE_CODE (arg0
) == CONVERT_EXPR
))
9539 /* If we are widening one operand of an integer comparison,
9540 see if the other operand is similarly being widened. Perhaps we
9541 can do the comparison in the narrower type. */
9542 tem
= fold_widened_comparison (code
, type
, arg0
, arg1
);
9546 /* Or if we are changing signedness. */
9547 tem
= fold_sign_changed_comparison (code
, type
, arg0
, arg1
);
9552 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
9553 constant, we can simplify it. */
9554 else if (TREE_CODE (arg1
) == INTEGER_CST
9555 && (TREE_CODE (arg0
) == MIN_EXPR
9556 || TREE_CODE (arg0
) == MAX_EXPR
)
9557 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
9559 tem
= optimize_minmax_comparison (code
, type
, op0
, op1
);
9566 /* If we are comparing an ABS_EXPR with a constant, we can
9567 convert all the cases into explicit comparisons, but they may
9568 well not be faster than doing the ABS and one comparison.
9569 But ABS (X) <= C is a range comparison, which becomes a subtraction
9570 and a comparison, and is probably faster. */
9571 else if (code
== LE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
9572 && TREE_CODE (arg0
) == ABS_EXPR
9573 && ! TREE_SIDE_EFFECTS (arg0
)
9574 && (0 != (tem
= negate_expr (arg1
)))
9575 && TREE_CODE (tem
) == INTEGER_CST
9576 && ! TREE_CONSTANT_OVERFLOW (tem
))
9577 return fold_build2 (TRUTH_ANDIF_EXPR
, type
,
9578 build2 (GE_EXPR
, type
,
9579 TREE_OPERAND (arg0
, 0), tem
),
9580 build2 (LE_EXPR
, type
,
9581 TREE_OPERAND (arg0
, 0), arg1
));
9583 /* Convert ABS_EXPR<x> >= 0 to true. */
9584 else if (code
== GE_EXPR
9585 && tree_expr_nonnegative_p (arg0
)
9586 && (integer_zerop (arg1
)
9587 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
)))
9588 && real_zerop (arg1
))))
9589 return omit_one_operand (type
, integer_one_node
, arg0
);
9591 /* Convert ABS_EXPR<x> < 0 to false. */
9592 else if (code
== LT_EXPR
9593 && tree_expr_nonnegative_p (arg0
)
9594 && (integer_zerop (arg1
) || real_zerop (arg1
)))
9595 return omit_one_operand (type
, integer_zero_node
, arg0
);
9597 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
9598 else if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
9599 && TREE_CODE (arg0
) == ABS_EXPR
9600 && (integer_zerop (arg1
) || real_zerop (arg1
)))
9601 return fold_build2 (code
, type
, TREE_OPERAND (arg0
, 0), arg1
);
9603 /* If this is an EQ or NE comparison with zero and ARG0 is
9604 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
9605 two operations, but the latter can be done in one less insn
9606 on machines that have only two-operand insns or on which a
9607 constant cannot be the first operand. */
9608 if (integer_zerop (arg1
) && (code
== EQ_EXPR
|| code
== NE_EXPR
)
9609 && TREE_CODE (arg0
) == BIT_AND_EXPR
)
9611 tree arg00
= TREE_OPERAND (arg0
, 0);
9612 tree arg01
= TREE_OPERAND (arg0
, 1);
9613 if (TREE_CODE (arg00
) == LSHIFT_EXPR
9614 && integer_onep (TREE_OPERAND (arg00
, 0)))
9616 fold_build2 (code
, type
,
9617 build2 (BIT_AND_EXPR
, TREE_TYPE (arg0
),
9618 build2 (RSHIFT_EXPR
, TREE_TYPE (arg00
),
9619 arg01
, TREE_OPERAND (arg00
, 1)),
9620 fold_convert (TREE_TYPE (arg0
),
9623 else if (TREE_CODE (TREE_OPERAND (arg0
, 1)) == LSHIFT_EXPR
9624 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 1), 0)))
9626 fold_build2 (code
, type
,
9627 build2 (BIT_AND_EXPR
, TREE_TYPE (arg0
),
9628 build2 (RSHIFT_EXPR
, TREE_TYPE (arg01
),
9629 arg00
, TREE_OPERAND (arg01
, 1)),
9630 fold_convert (TREE_TYPE (arg0
),
9635 /* If this is an NE or EQ comparison of zero against the result of a
9636 signed MOD operation whose second operand is a power of 2, make
9637 the MOD operation unsigned since it is simpler and equivalent. */
9638 if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
9639 && integer_zerop (arg1
)
9640 && !TYPE_UNSIGNED (TREE_TYPE (arg0
))
9641 && (TREE_CODE (arg0
) == TRUNC_MOD_EXPR
9642 || TREE_CODE (arg0
) == CEIL_MOD_EXPR
9643 || TREE_CODE (arg0
) == FLOOR_MOD_EXPR
9644 || TREE_CODE (arg0
) == ROUND_MOD_EXPR
)
9645 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
9647 tree newtype
= lang_hooks
.types
.unsigned_type (TREE_TYPE (arg0
));
9648 tree newmod
= fold_build2 (TREE_CODE (arg0
), newtype
,
9649 fold_convert (newtype
,
9650 TREE_OPERAND (arg0
, 0)),
9651 fold_convert (newtype
,
9652 TREE_OPERAND (arg0
, 1)));
9654 return fold_build2 (code
, type
, newmod
,
9655 fold_convert (newtype
, arg1
));
9658 /* If this is an NE comparison of zero with an AND of one, remove the
9659 comparison since the AND will give the correct value. */
9660 if (code
== NE_EXPR
&& integer_zerop (arg1
)
9661 && TREE_CODE (arg0
) == BIT_AND_EXPR
9662 && integer_onep (TREE_OPERAND (arg0
, 1)))
9663 return fold_convert (type
, arg0
);
9665 /* If we have (A & C) == C where C is a power of 2, convert this into
9666 (A & C) != 0. Similarly for NE_EXPR. */
9667 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
9668 && TREE_CODE (arg0
) == BIT_AND_EXPR
9669 && integer_pow2p (TREE_OPERAND (arg0
, 1))
9670 && operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
9671 return fold_build2 (code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
, type
,
9672 arg0
, fold_convert (TREE_TYPE (arg0
),
9673 integer_zero_node
));
9675 /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
9676 bit, then fold the expression into A < 0 or A >= 0. */
9677 tem
= fold_single_bit_test_into_sign_test (code
, arg0
, arg1
, type
);
9681 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
9682 Similarly for NE_EXPR. */
9683 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
9684 && TREE_CODE (arg0
) == BIT_AND_EXPR
9685 && TREE_CODE (arg1
) == INTEGER_CST
9686 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
9688 tree notc
= fold_build1 (BIT_NOT_EXPR
,
9689 TREE_TYPE (TREE_OPERAND (arg0
, 1)),
9690 TREE_OPERAND (arg0
, 1));
9691 tree dandnotc
= fold_build2 (BIT_AND_EXPR
, TREE_TYPE (arg0
),
9693 tree rslt
= code
== EQ_EXPR
? integer_zero_node
: integer_one_node
;
9694 if (integer_nonzerop (dandnotc
))
9695 return omit_one_operand (type
, rslt
, arg0
);
9698 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
9699 Similarly for NE_EXPR. */
9700 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
9701 && TREE_CODE (arg0
) == BIT_IOR_EXPR
9702 && TREE_CODE (arg1
) == INTEGER_CST
9703 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
9705 tree notd
= fold_build1 (BIT_NOT_EXPR
, TREE_TYPE (arg1
), arg1
);
9706 tree candnotd
= fold_build2 (BIT_AND_EXPR
, TREE_TYPE (arg0
),
9707 TREE_OPERAND (arg0
, 1), notd
);
9708 tree rslt
= code
== EQ_EXPR
? integer_zero_node
: integer_one_node
;
9709 if (integer_nonzerop (candnotd
))
9710 return omit_one_operand (type
, rslt
, arg0
);
9713 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
9714 and similarly for >= into !=. */
9715 if ((code
== LT_EXPR
|| code
== GE_EXPR
)
9716 && TYPE_UNSIGNED (TREE_TYPE (arg0
))
9717 && TREE_CODE (arg1
) == LSHIFT_EXPR
9718 && integer_onep (TREE_OPERAND (arg1
, 0)))
9719 return build2 (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
9720 build2 (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
9721 TREE_OPERAND (arg1
, 1)),
9722 build_int_cst (TREE_TYPE (arg0
), 0));
9724 else if ((code
== LT_EXPR
|| code
== GE_EXPR
)
9725 && TYPE_UNSIGNED (TREE_TYPE (arg0
))
9726 && (TREE_CODE (arg1
) == NOP_EXPR
9727 || TREE_CODE (arg1
) == CONVERT_EXPR
)
9728 && TREE_CODE (TREE_OPERAND (arg1
, 0)) == LSHIFT_EXPR
9729 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0)))
9731 build2 (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
9732 fold_convert (TREE_TYPE (arg0
),
9733 build2 (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
9734 TREE_OPERAND (TREE_OPERAND (arg1
, 0),
9736 build_int_cst (TREE_TYPE (arg0
), 0));
9738 /* Simplify comparison of something with itself. (For IEEE
9739 floating-point, we can only do some of these simplifications.) */
9740 if (operand_equal_p (arg0
, arg1
, 0))
9745 if (! FLOAT_TYPE_P (TREE_TYPE (arg0
))
9746 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
))))
9747 return constant_boolean_node (1, type
);
9752 if (! FLOAT_TYPE_P (TREE_TYPE (arg0
))
9753 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
))))
9754 return constant_boolean_node (1, type
);
9755 return fold_build2 (EQ_EXPR
, type
, arg0
, arg1
);
9758 /* For NE, we can only do this simplification if integer
9759 or we don't honor IEEE floating point NaNs. */
9760 if (FLOAT_TYPE_P (TREE_TYPE (arg0
))
9761 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
))))
9763 /* ... fall through ... */
9766 return constant_boolean_node (0, type
);
9772 /* If we are comparing an expression that just has comparisons
9773 of two integer values, arithmetic expressions of those comparisons,
9774 and constants, we can simplify it. There are only three cases
9775 to check: the two values can either be equal, the first can be
9776 greater, or the second can be greater. Fold the expression for
9777 those three values. Since each value must be 0 or 1, we have
9778 eight possibilities, each of which corresponds to the constant 0
9779 or 1 or one of the six possible comparisons.
9781 This handles common cases like (a > b) == 0 but also handles
9782 expressions like ((x > y) - (y > x)) > 0, which supposedly
9783 occur in macroized code. */
9785 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) != INTEGER_CST
)
9787 tree cval1
= 0, cval2
= 0;
9790 if (twoval_comparison_p (arg0
, &cval1
, &cval2
, &save_p
)
9791 /* Don't handle degenerate cases here; they should already
9792 have been handled anyway. */
9793 && cval1
!= 0 && cval2
!= 0
9794 && ! (TREE_CONSTANT (cval1
) && TREE_CONSTANT (cval2
))
9795 && TREE_TYPE (cval1
) == TREE_TYPE (cval2
)
9796 && INTEGRAL_TYPE_P (TREE_TYPE (cval1
))
9797 && TYPE_MAX_VALUE (TREE_TYPE (cval1
))
9798 && TYPE_MAX_VALUE (TREE_TYPE (cval2
))
9799 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1
)),
9800 TYPE_MAX_VALUE (TREE_TYPE (cval2
)), 0))
9802 tree maxval
= TYPE_MAX_VALUE (TREE_TYPE (cval1
));
9803 tree minval
= TYPE_MIN_VALUE (TREE_TYPE (cval1
));
9805 /* We can't just pass T to eval_subst in case cval1 or cval2
9806 was the same as ARG1. */
9809 = fold_build2 (code
, type
,
9810 eval_subst (arg0
, cval1
, maxval
,
9814 = fold_build2 (code
, type
,
9815 eval_subst (arg0
, cval1
, maxval
,
9819 = fold_build2 (code
, type
,
9820 eval_subst (arg0
, cval1
, minval
,
9824 /* All three of these results should be 0 or 1. Confirm they
9825 are. Then use those values to select the proper code
9828 if ((integer_zerop (high_result
)
9829 || integer_onep (high_result
))
9830 && (integer_zerop (equal_result
)
9831 || integer_onep (equal_result
))
9832 && (integer_zerop (low_result
)
9833 || integer_onep (low_result
)))
9835 /* Make a 3-bit mask with the high-order bit being the
9836 value for `>', the next for '=', and the low for '<'. */
9837 switch ((integer_onep (high_result
) * 4)
9838 + (integer_onep (equal_result
) * 2)
9839 + integer_onep (low_result
))
9843 return omit_one_operand (type
, integer_zero_node
, arg0
);
9864 return omit_one_operand (type
, integer_one_node
, arg0
);
9868 return save_expr (build2 (code
, type
, cval1
, cval2
));
9870 return fold_build2 (code
, type
, cval1
, cval2
);
9875 /* If this is a comparison of a field, we may be able to simplify it. */
9876 if (((TREE_CODE (arg0
) == COMPONENT_REF
9877 && lang_hooks
.can_use_bit_fields_p ())
9878 || TREE_CODE (arg0
) == BIT_FIELD_REF
)
9879 && (code
== EQ_EXPR
|| code
== NE_EXPR
)
9880 /* Handle the constant case even without -O
9881 to make sure the warnings are given. */
9882 && (optimize
|| TREE_CODE (arg1
) == INTEGER_CST
))
9884 t1
= optimize_bit_field_compare (code
, type
, arg0
, arg1
);
9889 /* Fold a comparison of the address of COMPONENT_REFs with the same
9890 type and component to a comparison of the address of the base
9891 object. In short, &x->a OP &y->a to x OP y and
9892 &x->a OP &y.a to x OP &y */
9893 if (TREE_CODE (arg0
) == ADDR_EXPR
9894 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == COMPONENT_REF
9895 && TREE_CODE (arg1
) == ADDR_EXPR
9896 && TREE_CODE (TREE_OPERAND (arg1
, 0)) == COMPONENT_REF
)
9898 tree cref0
= TREE_OPERAND (arg0
, 0);
9899 tree cref1
= TREE_OPERAND (arg1
, 0);
9900 if (TREE_OPERAND (cref0
, 1) == TREE_OPERAND (cref1
, 1))
9902 tree op0
= TREE_OPERAND (cref0
, 0);
9903 tree op1
= TREE_OPERAND (cref1
, 0);
9904 return fold_build2 (code
, type
,
9905 build_fold_addr_expr (op0
),
9906 build_fold_addr_expr (op1
));
9910 /* Optimize comparisons of strlen vs zero to a compare of the
9911 first character of the string vs zero. To wit,
9912 strlen(ptr) == 0 => *ptr == 0
9913 strlen(ptr) != 0 => *ptr != 0
9914 Other cases should reduce to one of these two (or a constant)
9915 due to the return value of strlen being unsigned. */
9916 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
9917 && integer_zerop (arg1
)
9918 && TREE_CODE (arg0
) == CALL_EXPR
)
9920 tree fndecl
= get_callee_fndecl (arg0
);
9924 && DECL_BUILT_IN_CLASS (fndecl
) == BUILT_IN_NORMAL
9925 && DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STRLEN
9926 && (arglist
= TREE_OPERAND (arg0
, 1))
9927 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist
))) == POINTER_TYPE
9928 && ! TREE_CHAIN (arglist
))
9930 tree iref
= build_fold_indirect_ref (TREE_VALUE (arglist
));
9931 return fold_build2 (code
, type
, iref
,
9932 build_int_cst (TREE_TYPE (iref
), 0));
9936 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
9937 into a single range test. */
9938 if ((TREE_CODE (arg0
) == TRUNC_DIV_EXPR
9939 || TREE_CODE (arg0
) == EXACT_DIV_EXPR
)
9940 && TREE_CODE (arg1
) == INTEGER_CST
9941 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
9942 && !integer_zerop (TREE_OPERAND (arg0
, 1))
9943 && !TREE_OVERFLOW (TREE_OPERAND (arg0
, 1))
9944 && !TREE_OVERFLOW (arg1
))
9946 t1
= fold_div_compare (code
, type
, arg0
, arg1
);
9947 if (t1
!= NULL_TREE
)
9951 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
9952 && integer_zerop (arg1
)
9953 && tree_expr_nonzero_p (arg0
))
9955 tree res
= constant_boolean_node (code
==NE_EXPR
, type
);
9956 return omit_one_operand (type
, res
, arg0
);
9959 t1
= fold_relational_const (code
, type
, arg0
, arg1
);
9960 return t1
== NULL_TREE
? NULL_TREE
: t1
;
9962 case UNORDERED_EXPR
:
9970 if (TREE_CODE (arg0
) == REAL_CST
&& TREE_CODE (arg1
) == REAL_CST
)
9972 t1
= fold_relational_const (code
, type
, arg0
, arg1
);
9973 if (t1
!= NULL_TREE
)
9977 /* If the first operand is NaN, the result is constant. */
9978 if (TREE_CODE (arg0
) == REAL_CST
9979 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0
))
9980 && (code
!= LTGT_EXPR
|| ! flag_trapping_math
))
9982 t1
= (code
== ORDERED_EXPR
|| code
== LTGT_EXPR
)
9985 return omit_one_operand (type
, t1
, arg1
);
9988 /* If the second operand is NaN, the result is constant. */
9989 if (TREE_CODE (arg1
) == REAL_CST
9990 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
))
9991 && (code
!= LTGT_EXPR
|| ! flag_trapping_math
))
9993 t1
= (code
== ORDERED_EXPR
|| code
== LTGT_EXPR
)
9996 return omit_one_operand (type
, t1
, arg0
);
9999 /* Simplify unordered comparison of something with itself. */
10000 if ((code
== UNLE_EXPR
|| code
== UNGE_EXPR
|| code
== UNEQ_EXPR
)
10001 && operand_equal_p (arg0
, arg1
, 0))
10002 return constant_boolean_node (1, type
);
10004 if (code
== LTGT_EXPR
10005 && !flag_trapping_math
10006 && operand_equal_p (arg0
, arg1
, 0))
10007 return constant_boolean_node (0, type
);
10009 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
10011 tree targ0
= strip_float_extensions (arg0
);
10012 tree targ1
= strip_float_extensions (arg1
);
10013 tree newtype
= TREE_TYPE (targ0
);
10015 if (TYPE_PRECISION (TREE_TYPE (targ1
)) > TYPE_PRECISION (newtype
))
10016 newtype
= TREE_TYPE (targ1
);
10018 if (TYPE_PRECISION (newtype
) < TYPE_PRECISION (TREE_TYPE (arg0
)))
10019 return fold_build2 (code
, type
, fold_convert (newtype
, targ0
),
10020 fold_convert (newtype
, targ1
));
10025 case COMPOUND_EXPR
:
10026 /* When pedantic, a compound expression can be neither an lvalue
10027 nor an integer constant expression. */
10028 if (TREE_SIDE_EFFECTS (arg0
) || TREE_CONSTANT (arg1
))
10030 /* Don't let (0, 0) be null pointer constant. */
10031 tem
= integer_zerop (arg1
) ? build1 (NOP_EXPR
, type
, arg1
)
10032 : fold_convert (type
, arg1
);
10033 return pedantic_non_lvalue (tem
);
10036 if ((TREE_CODE (arg0
) == REAL_CST
10037 && TREE_CODE (arg1
) == REAL_CST
)
10038 || (TREE_CODE (arg0
) == INTEGER_CST
10039 && TREE_CODE (arg1
) == INTEGER_CST
))
10040 return build_complex (type
, arg0
, arg1
);
10044 /* An ASSERT_EXPR should never be passed to fold_binary. */
10045 gcc_unreachable ();
10049 } /* switch (code) */
10052 /* Callback for walk_tree, looking for LABEL_EXPR.
10053 Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
10054 Do not check the sub-tree of GOTO_EXPR. */
10057 contains_label_1 (tree
*tp
,
10058 int *walk_subtrees
,
10059 void *data ATTRIBUTE_UNUSED
)
10061 switch (TREE_CODE (*tp
))
10066 *walk_subtrees
= 0;
10073 /* Checks whether the sub-tree ST contains a label LABEL_EXPR which is
10074 accessible from outside the sub-tree. Returns NULL_TREE if no
10075 addressable label is found. */
10078 contains_label_p (tree st
)
10080 return (walk_tree (&st
, contains_label_1
, NULL
, NULL
) != NULL_TREE
);
10083 /* Fold a ternary expression of code CODE and type TYPE with operands
10084 OP0, OP1, and OP2. Return the folded expression if folding is
10085 successful. Otherwise, return NULL_TREE. */
10088 fold_ternary (enum tree_code code
, tree type
, tree op0
, tree op1
, tree op2
)
10091 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
;
10092 enum tree_code_class kind
= TREE_CODE_CLASS (code
);
10094 gcc_assert (IS_EXPR_CODE_CLASS (kind
)
10095 && TREE_CODE_LENGTH (code
) == 3);
10097 /* Strip any conversions that don't change the mode. This is safe
10098 for every expression, except for a comparison expression because
10099 its signedness is derived from its operands. So, in the latter
10100 case, only strip conversions that don't change the signedness.
10102 Note that this is done as an internal manipulation within the
10103 constant folder, in order to find the simplest representation of
10104 the arguments so that their form can be studied. In any cases,
10105 the appropriate type conversions should be put back in the tree
10106 that will get out of the constant folder. */
10121 case COMPONENT_REF
:
10122 if (TREE_CODE (arg0
) == CONSTRUCTOR
10123 && ! type_contains_placeholder_p (TREE_TYPE (arg0
)))
10125 unsigned HOST_WIDE_INT idx
;
10127 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0
), idx
, field
, value
)
10134 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
10135 so all simple results must be passed through pedantic_non_lvalue. */
10136 if (TREE_CODE (arg0
) == INTEGER_CST
)
10138 tree unused_op
= integer_zerop (arg0
) ? op1
: op2
;
10139 tem
= integer_zerop (arg0
) ? op2
: op1
;
10140 /* Only optimize constant conditions when the selected branch
10141 has the same type as the COND_EXPR. This avoids optimizing
10142 away "c ? x : throw", where the throw has a void type.
10143 Avoid throwing away that operand which contains label. */
10144 if ((!TREE_SIDE_EFFECTS (unused_op
)
10145 || !contains_label_p (unused_op
))
10146 && (! VOID_TYPE_P (TREE_TYPE (tem
))
10147 || VOID_TYPE_P (type
)))
10148 return pedantic_non_lvalue (tem
);
10151 if (operand_equal_p (arg1
, op2
, 0))
10152 return pedantic_omit_one_operand (type
, arg1
, arg0
);
10154 /* If we have A op B ? A : C, we may be able to convert this to a
10155 simpler expression, depending on the operation and the values
10156 of B and C. Signed zeros prevent all of these transformations,
10157 for reasons given above each one.
10159 Also try swapping the arguments and inverting the conditional. */
10160 if (COMPARISON_CLASS_P (arg0
)
10161 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
10162 arg1
, TREE_OPERAND (arg0
, 1))
10163 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1
))))
10165 tem
= fold_cond_expr_with_comparison (type
, arg0
, op1
, op2
);
10170 if (COMPARISON_CLASS_P (arg0
)
10171 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
10173 TREE_OPERAND (arg0
, 1))
10174 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2
))))
10176 tem
= invert_truthvalue (arg0
);
10177 if (COMPARISON_CLASS_P (tem
))
10179 tem
= fold_cond_expr_with_comparison (type
, tem
, op2
, op1
);
10185 /* If the second operand is simpler than the third, swap them
10186 since that produces better jump optimization results. */
10187 if (truth_value_p (TREE_CODE (arg0
))
10188 && tree_swap_operands_p (op1
, op2
, false))
10190 /* See if this can be inverted. If it can't, possibly because
10191 it was a floating-point inequality comparison, don't do
10193 tem
= invert_truthvalue (arg0
);
10195 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
10196 return fold_build3 (code
, type
, tem
, op2
, op1
);
10199 /* Convert A ? 1 : 0 to simply A. */
10200 if (integer_onep (op1
)
10201 && integer_zerop (op2
)
10202 /* If we try to convert OP0 to our type, the
10203 call to fold will try to move the conversion inside
10204 a COND, which will recurse. In that case, the COND_EXPR
10205 is probably the best choice, so leave it alone. */
10206 && type
== TREE_TYPE (arg0
))
10207 return pedantic_non_lvalue (arg0
);
10209 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
10210 over COND_EXPR in cases such as floating point comparisons. */
10211 if (integer_zerop (op1
)
10212 && integer_onep (op2
)
10213 && truth_value_p (TREE_CODE (arg0
)))
10214 return pedantic_non_lvalue (fold_convert (type
,
10215 invert_truthvalue (arg0
)));
10217 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
10218 if (TREE_CODE (arg0
) == LT_EXPR
10219 && integer_zerop (TREE_OPERAND (arg0
, 1))
10220 && integer_zerop (op2
)
10221 && (tem
= sign_bit_p (TREE_OPERAND (arg0
, 0), arg1
)))
10222 return fold_convert (type
, fold_build2 (BIT_AND_EXPR
,
10223 TREE_TYPE (tem
), tem
, arg1
));
10225 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
10226 already handled above. */
10227 if (TREE_CODE (arg0
) == BIT_AND_EXPR
10228 && integer_onep (TREE_OPERAND (arg0
, 1))
10229 && integer_zerop (op2
)
10230 && integer_pow2p (arg1
))
10232 tree tem
= TREE_OPERAND (arg0
, 0);
10234 if (TREE_CODE (tem
) == RSHIFT_EXPR
10235 && TREE_CODE (TREE_OPERAND (tem
, 1)) == INTEGER_CST
10236 && (unsigned HOST_WIDE_INT
) tree_log2 (arg1
) ==
10237 TREE_INT_CST_LOW (TREE_OPERAND (tem
, 1)))
10238 return fold_build2 (BIT_AND_EXPR
, type
,
10239 TREE_OPERAND (tem
, 0), arg1
);
10242 /* A & N ? N : 0 is simply A & N if N is a power of two. This
10243 is probably obsolete because the first operand should be a
10244 truth value (that's why we have the two cases above), but let's
10245 leave it in until we can confirm this for all front-ends. */
10246 if (integer_zerop (op2
)
10247 && TREE_CODE (arg0
) == NE_EXPR
10248 && integer_zerop (TREE_OPERAND (arg0
, 1))
10249 && integer_pow2p (arg1
)
10250 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == BIT_AND_EXPR
10251 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1),
10252 arg1
, OEP_ONLY_CONST
))
10253 return pedantic_non_lvalue (fold_convert (type
,
10254 TREE_OPERAND (arg0
, 0)));
10256 /* Convert A ? B : 0 into A && B if A and B are truth values. */
10257 if (integer_zerop (op2
)
10258 && truth_value_p (TREE_CODE (arg0
))
10259 && truth_value_p (TREE_CODE (arg1
)))
10260 return fold_build2 (TRUTH_ANDIF_EXPR
, type
, arg0
, arg1
);
10262 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
10263 if (integer_onep (op2
)
10264 && truth_value_p (TREE_CODE (arg0
))
10265 && truth_value_p (TREE_CODE (arg1
)))
10267 /* Only perform transformation if ARG0 is easily inverted. */
10268 tem
= invert_truthvalue (arg0
);
10269 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
10270 return fold_build2 (TRUTH_ORIF_EXPR
, type
, tem
, arg1
);
10273 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
10274 if (integer_zerop (arg1
)
10275 && truth_value_p (TREE_CODE (arg0
))
10276 && truth_value_p (TREE_CODE (op2
)))
10278 /* Only perform transformation if ARG0 is easily inverted. */
10279 tem
= invert_truthvalue (arg0
);
10280 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
10281 return fold_build2 (TRUTH_ANDIF_EXPR
, type
, tem
, op2
);
10284 /* Convert A ? 1 : B into A || B if A and B are truth values. */
10285 if (integer_onep (arg1
)
10286 && truth_value_p (TREE_CODE (arg0
))
10287 && truth_value_p (TREE_CODE (op2
)))
10288 return fold_build2 (TRUTH_ORIF_EXPR
, type
, arg0
, op2
);
10293 /* Check for a built-in function. */
10294 if (TREE_CODE (op0
) == ADDR_EXPR
10295 && TREE_CODE (TREE_OPERAND (op0
, 0)) == FUNCTION_DECL
10296 && DECL_BUILT_IN (TREE_OPERAND (op0
, 0)))
10297 return fold_builtin (TREE_OPERAND (op0
, 0), op1
, false);
10300 case BIT_FIELD_REF
:
10301 if (TREE_CODE (arg0
) == VECTOR_CST
10302 && type
== TREE_TYPE (TREE_TYPE (arg0
))
10303 && host_integerp (arg1
, 1)
10304 && host_integerp (op2
, 1))
10306 unsigned HOST_WIDE_INT width
= tree_low_cst (arg1
, 1);
10307 unsigned HOST_WIDE_INT idx
= tree_low_cst (op2
, 1);
10310 && simple_cst_equal (arg1
, TYPE_SIZE (type
)) == 1
10311 && (idx
% width
) == 0
10312 && (idx
= idx
/ width
)
10313 < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0
)))
10315 tree elements
= TREE_VECTOR_CST_ELTS (arg0
);
10316 while (idx
-- > 0 && elements
)
10317 elements
= TREE_CHAIN (elements
);
10319 return TREE_VALUE (elements
);
10321 return fold_convert (type
, integer_zero_node
);
10328 } /* switch (code) */
10331 /* Perform constant folding and related simplification of EXPR.
10332 The related simplifications include x*1 => x, x*0 => 0, etc.,
10333 and application of the associative law.
10334 NOP_EXPR conversions may be removed freely (as long as we
10335 are careful not to change the type of the overall expression).
10336 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
10337 but we can constant-fold them if they have constant operands. */
10339 #ifdef ENABLE_FOLD_CHECKING
10340 # define fold(x) fold_1 (x)
10341 static tree
fold_1 (tree
);
10347 const tree t
= expr
;
10348 enum tree_code code
= TREE_CODE (t
);
10349 enum tree_code_class kind
= TREE_CODE_CLASS (code
);
10352 /* Return right away if a constant. */
10353 if (kind
== tcc_constant
)
10356 if (IS_EXPR_CODE_CLASS (kind
))
10358 tree type
= TREE_TYPE (t
);
10359 tree op0
, op1
, op2
;
10361 switch (TREE_CODE_LENGTH (code
))
10364 op0
= TREE_OPERAND (t
, 0);
10365 tem
= fold_unary (code
, type
, op0
);
10366 return tem
? tem
: expr
;
10368 op0
= TREE_OPERAND (t
, 0);
10369 op1
= TREE_OPERAND (t
, 1);
10370 tem
= fold_binary (code
, type
, op0
, op1
);
10371 return tem
? tem
: expr
;
10373 op0
= TREE_OPERAND (t
, 0);
10374 op1
= TREE_OPERAND (t
, 1);
10375 op2
= TREE_OPERAND (t
, 2);
10376 tem
= fold_ternary (code
, type
, op0
, op1
, op2
);
10377 return tem
? tem
: expr
;
10386 return fold (DECL_INITIAL (t
));
10390 } /* switch (code) */
10393 #ifdef ENABLE_FOLD_CHECKING
10396 static void fold_checksum_tree (tree
, struct md5_ctx
*, htab_t
);
10397 static void fold_check_failed (tree
, tree
);
10398 void print_fold_checksum (tree
);
10400 /* When --enable-checking=fold, compute a digest of expr before
10401 and after actual fold call to see if fold did not accidentally
10402 change original expr. */
10408 struct md5_ctx ctx
;
10409 unsigned char checksum_before
[16], checksum_after
[16];
10412 ht
= htab_create (32, htab_hash_pointer
, htab_eq_pointer
, NULL
);
10413 md5_init_ctx (&ctx
);
10414 fold_checksum_tree (expr
, &ctx
, ht
);
10415 md5_finish_ctx (&ctx
, checksum_before
);
10418 ret
= fold_1 (expr
);
10420 md5_init_ctx (&ctx
);
10421 fold_checksum_tree (expr
, &ctx
, ht
);
10422 md5_finish_ctx (&ctx
, checksum_after
);
10425 if (memcmp (checksum_before
, checksum_after
, 16))
10426 fold_check_failed (expr
, ret
);
10432 print_fold_checksum (tree expr
)
10434 struct md5_ctx ctx
;
10435 unsigned char checksum
[16], cnt
;
10438 ht
= htab_create (32, htab_hash_pointer
, htab_eq_pointer
, NULL
);
10439 md5_init_ctx (&ctx
);
10440 fold_checksum_tree (expr
, &ctx
, ht
);
10441 md5_finish_ctx (&ctx
, checksum
);
10443 for (cnt
= 0; cnt
< 16; ++cnt
)
10444 fprintf (stderr
, "%02x", checksum
[cnt
]);
10445 putc ('\n', stderr
);
10449 fold_check_failed (tree expr ATTRIBUTE_UNUSED
, tree ret ATTRIBUTE_UNUSED
)
10451 internal_error ("fold check: original tree changed by fold");
10455 fold_checksum_tree (tree expr
, struct md5_ctx
*ctx
, htab_t ht
)
10458 enum tree_code code
;
10459 char buf
[sizeof (struct tree_function_decl
)];
10464 gcc_assert ((sizeof (struct tree_exp
) + 5 * sizeof (tree
)
10465 <= sizeof (struct tree_function_decl
))
10466 && sizeof (struct tree_type
) <= sizeof (struct tree_function_decl
));
10469 slot
= htab_find_slot (ht
, expr
, INSERT
);
10473 code
= TREE_CODE (expr
);
10474 if (TREE_CODE_CLASS (code
) == tcc_declaration
10475 && DECL_ASSEMBLER_NAME_SET_P (expr
))
10477 /* Allow DECL_ASSEMBLER_NAME to be modified. */
10478 memcpy (buf
, expr
, tree_size (expr
));
10480 SET_DECL_ASSEMBLER_NAME (expr
, NULL
);
10482 else if (TREE_CODE_CLASS (code
) == tcc_type
10483 && (TYPE_POINTER_TO (expr
) || TYPE_REFERENCE_TO (expr
)
10484 || TYPE_CACHED_VALUES_P (expr
)
10485 || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr
)))
10487 /* Allow these fields to be modified. */
10488 memcpy (buf
, expr
, tree_size (expr
));
10490 TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr
) = 0;
10491 TYPE_POINTER_TO (expr
) = NULL
;
10492 TYPE_REFERENCE_TO (expr
) = NULL
;
10493 if (TYPE_CACHED_VALUES_P (expr
))
10495 TYPE_CACHED_VALUES_P (expr
) = 0;
10496 TYPE_CACHED_VALUES (expr
) = NULL
;
10499 md5_process_bytes (expr
, tree_size (expr
), ctx
);
10500 fold_checksum_tree (TREE_TYPE (expr
), ctx
, ht
);
10501 if (TREE_CODE_CLASS (code
) != tcc_type
10502 && TREE_CODE_CLASS (code
) != tcc_declaration
10503 && code
!= TREE_LIST
)
10504 fold_checksum_tree (TREE_CHAIN (expr
), ctx
, ht
);
10505 switch (TREE_CODE_CLASS (code
))
10511 md5_process_bytes (TREE_STRING_POINTER (expr
),
10512 TREE_STRING_LENGTH (expr
), ctx
);
10515 fold_checksum_tree (TREE_REALPART (expr
), ctx
, ht
);
10516 fold_checksum_tree (TREE_IMAGPART (expr
), ctx
, ht
);
10519 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr
), ctx
, ht
);
10525 case tcc_exceptional
:
10529 fold_checksum_tree (TREE_PURPOSE (expr
), ctx
, ht
);
10530 fold_checksum_tree (TREE_VALUE (expr
), ctx
, ht
);
10531 expr
= TREE_CHAIN (expr
);
10532 goto recursive_label
;
10535 for (i
= 0; i
< TREE_VEC_LENGTH (expr
); ++i
)
10536 fold_checksum_tree (TREE_VEC_ELT (expr
, i
), ctx
, ht
);
10542 case tcc_expression
:
10543 case tcc_reference
:
10544 case tcc_comparison
:
10547 case tcc_statement
:
10548 len
= TREE_CODE_LENGTH (code
);
10549 for (i
= 0; i
< len
; ++i
)
10550 fold_checksum_tree (TREE_OPERAND (expr
, i
), ctx
, ht
);
10552 case tcc_declaration
:
10553 fold_checksum_tree (DECL_NAME (expr
), ctx
, ht
);
10554 fold_checksum_tree (DECL_CONTEXT (expr
), ctx
, ht
);
10555 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr
), TS_DECL_COMMON
))
10557 fold_checksum_tree (DECL_SIZE (expr
), ctx
, ht
);
10558 fold_checksum_tree (DECL_SIZE_UNIT (expr
), ctx
, ht
);
10559 fold_checksum_tree (DECL_INITIAL (expr
), ctx
, ht
);
10560 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr
), ctx
, ht
);
10561 fold_checksum_tree (DECL_ATTRIBUTES (expr
), ctx
, ht
);
10563 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr
), TS_DECL_WITH_VIS
))
10564 fold_checksum_tree (DECL_SECTION_NAME (expr
), ctx
, ht
);
10566 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr
), TS_DECL_NON_COMMON
))
10568 fold_checksum_tree (DECL_VINDEX (expr
), ctx
, ht
);
10569 fold_checksum_tree (DECL_RESULT_FLD (expr
), ctx
, ht
);
10570 fold_checksum_tree (DECL_ARGUMENT_FLD (expr
), ctx
, ht
);
10574 if (TREE_CODE (expr
) == ENUMERAL_TYPE
)
10575 fold_checksum_tree (TYPE_VALUES (expr
), ctx
, ht
);
10576 fold_checksum_tree (TYPE_SIZE (expr
), ctx
, ht
);
10577 fold_checksum_tree (TYPE_SIZE_UNIT (expr
), ctx
, ht
);
10578 fold_checksum_tree (TYPE_ATTRIBUTES (expr
), ctx
, ht
);
10579 fold_checksum_tree (TYPE_NAME (expr
), ctx
, ht
);
10580 if (INTEGRAL_TYPE_P (expr
)
10581 || SCALAR_FLOAT_TYPE_P (expr
))
10583 fold_checksum_tree (TYPE_MIN_VALUE (expr
), ctx
, ht
);
10584 fold_checksum_tree (TYPE_MAX_VALUE (expr
), ctx
, ht
);
10586 fold_checksum_tree (TYPE_MAIN_VARIANT (expr
), ctx
, ht
);
10587 if (TREE_CODE (expr
) == RECORD_TYPE
10588 || TREE_CODE (expr
) == UNION_TYPE
10589 || TREE_CODE (expr
) == QUAL_UNION_TYPE
)
10590 fold_checksum_tree (TYPE_BINFO (expr
), ctx
, ht
);
10591 fold_checksum_tree (TYPE_CONTEXT (expr
), ctx
, ht
);
10600 /* Fold a unary tree expression with code CODE of type TYPE with an
10601 operand OP0. Return a folded expression if successful. Otherwise,
10602 return a tree expression with code CODE of type TYPE with an
10606 fold_build1_stat (enum tree_code code
, tree type
, tree op0 MEM_STAT_DECL
)
10609 #ifdef ENABLE_FOLD_CHECKING
10610 unsigned char checksum_before
[16], checksum_after
[16];
10611 struct md5_ctx ctx
;
10614 ht
= htab_create (32, htab_hash_pointer
, htab_eq_pointer
, NULL
);
10615 md5_init_ctx (&ctx
);
10616 fold_checksum_tree (op0
, &ctx
, ht
);
10617 md5_finish_ctx (&ctx
, checksum_before
);
10621 tem
= fold_unary (code
, type
, op0
);
10623 tem
= build1_stat (code
, type
, op0 PASS_MEM_STAT
);
10625 #ifdef ENABLE_FOLD_CHECKING
10626 md5_init_ctx (&ctx
);
10627 fold_checksum_tree (op0
, &ctx
, ht
);
10628 md5_finish_ctx (&ctx
, checksum_after
);
10631 if (memcmp (checksum_before
, checksum_after
, 16))
10632 fold_check_failed (op0
, tem
);
10637 /* Fold a binary tree expression with code CODE of type TYPE with
10638 operands OP0 and OP1. Return a folded expression if successful.
10639 Otherwise, return a tree expression with code CODE of type TYPE
10640 with operands OP0 and OP1. */
10643 fold_build2_stat (enum tree_code code
, tree type
, tree op0
, tree op1
10647 #ifdef ENABLE_FOLD_CHECKING
10648 unsigned char checksum_before_op0
[16],
10649 checksum_before_op1
[16],
10650 checksum_after_op0
[16],
10651 checksum_after_op1
[16];
10652 struct md5_ctx ctx
;
10655 ht
= htab_create (32, htab_hash_pointer
, htab_eq_pointer
, NULL
);
10656 md5_init_ctx (&ctx
);
10657 fold_checksum_tree (op0
, &ctx
, ht
);
10658 md5_finish_ctx (&ctx
, checksum_before_op0
);
10661 md5_init_ctx (&ctx
);
10662 fold_checksum_tree (op1
, &ctx
, ht
);
10663 md5_finish_ctx (&ctx
, checksum_before_op1
);
10667 tem
= fold_binary (code
, type
, op0
, op1
);
10669 tem
= build2_stat (code
, type
, op0
, op1 PASS_MEM_STAT
);
10671 #ifdef ENABLE_FOLD_CHECKING
10672 md5_init_ctx (&ctx
);
10673 fold_checksum_tree (op0
, &ctx
, ht
);
10674 md5_finish_ctx (&ctx
, checksum_after_op0
);
10677 if (memcmp (checksum_before_op0
, checksum_after_op0
, 16))
10678 fold_check_failed (op0
, tem
);
10680 md5_init_ctx (&ctx
);
10681 fold_checksum_tree (op1
, &ctx
, ht
);
10682 md5_finish_ctx (&ctx
, checksum_after_op1
);
10685 if (memcmp (checksum_before_op1
, checksum_after_op1
, 16))
10686 fold_check_failed (op1
, tem
);
10691 /* Fold a ternary tree expression with code CODE of type TYPE with
10692 operands OP0, OP1, and OP2. Return a folded expression if
10693 successful. Otherwise, return a tree expression with code CODE of
10694 type TYPE with operands OP0, OP1, and OP2. */
10697 fold_build3_stat (enum tree_code code
, tree type
, tree op0
, tree op1
, tree op2
10701 #ifdef ENABLE_FOLD_CHECKING
10702 unsigned char checksum_before_op0
[16],
10703 checksum_before_op1
[16],
10704 checksum_before_op2
[16],
10705 checksum_after_op0
[16],
10706 checksum_after_op1
[16],
10707 checksum_after_op2
[16];
10708 struct md5_ctx ctx
;
10711 ht
= htab_create (32, htab_hash_pointer
, htab_eq_pointer
, NULL
);
10712 md5_init_ctx (&ctx
);
10713 fold_checksum_tree (op0
, &ctx
, ht
);
10714 md5_finish_ctx (&ctx
, checksum_before_op0
);
10717 md5_init_ctx (&ctx
);
10718 fold_checksum_tree (op1
, &ctx
, ht
);
10719 md5_finish_ctx (&ctx
, checksum_before_op1
);
10722 md5_init_ctx (&ctx
);
10723 fold_checksum_tree (op2
, &ctx
, ht
);
10724 md5_finish_ctx (&ctx
, checksum_before_op2
);
10728 tem
= fold_ternary (code
, type
, op0
, op1
, op2
);
10730 tem
= build3_stat (code
, type
, op0
, op1
, op2 PASS_MEM_STAT
);
10732 #ifdef ENABLE_FOLD_CHECKING
10733 md5_init_ctx (&ctx
);
10734 fold_checksum_tree (op0
, &ctx
, ht
);
10735 md5_finish_ctx (&ctx
, checksum_after_op0
);
10738 if (memcmp (checksum_before_op0
, checksum_after_op0
, 16))
10739 fold_check_failed (op0
, tem
);
10741 md5_init_ctx (&ctx
);
10742 fold_checksum_tree (op1
, &ctx
, ht
);
10743 md5_finish_ctx (&ctx
, checksum_after_op1
);
10746 if (memcmp (checksum_before_op1
, checksum_after_op1
, 16))
10747 fold_check_failed (op1
, tem
);
10749 md5_init_ctx (&ctx
);
10750 fold_checksum_tree (op2
, &ctx
, ht
);
10751 md5_finish_ctx (&ctx
, checksum_after_op2
);
10754 if (memcmp (checksum_before_op2
, checksum_after_op2
, 16))
10755 fold_check_failed (op2
, tem
);
10760 /* Perform constant folding and related simplification of initializer
10761 expression EXPR. These behave identically to "fold_buildN" but ignore
10762 potential run-time traps and exceptions that fold must preserve. */
10764 #define START_FOLD_INIT \
10765 int saved_signaling_nans = flag_signaling_nans;\
10766 int saved_trapping_math = flag_trapping_math;\
10767 int saved_rounding_math = flag_rounding_math;\
10768 int saved_trapv = flag_trapv;\
10769 flag_signaling_nans = 0;\
10770 flag_trapping_math = 0;\
10771 flag_rounding_math = 0;\
10774 #define END_FOLD_INIT \
10775 flag_signaling_nans = saved_signaling_nans;\
10776 flag_trapping_math = saved_trapping_math;\
10777 flag_rounding_math = saved_rounding_math;\
10778 flag_trapv = saved_trapv
10781 fold_build1_initializer (enum tree_code code
, tree type
, tree op
)
10786 result
= fold_build1 (code
, type
, op
);
10793 fold_build2_initializer (enum tree_code code
, tree type
, tree op0
, tree op1
)
10798 result
= fold_build2 (code
, type
, op0
, op1
);
10805 fold_build3_initializer (enum tree_code code
, tree type
, tree op0
, tree op1
,
10811 result
= fold_build3 (code
, type
, op0
, op1
, op2
);
10817 #undef START_FOLD_INIT
10818 #undef END_FOLD_INIT
10820 /* Determine if first argument is a multiple of second argument. Return 0 if
10821 it is not, or we cannot easily determined it to be.
10823 An example of the sort of thing we care about (at this point; this routine
10824 could surely be made more general, and expanded to do what the *_DIV_EXPR's
10825 fold cases do now) is discovering that
10827 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
10833 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
10835 This code also handles discovering that
10837 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
10839 is a multiple of 8 so we don't have to worry about dealing with a
10840 possible remainder.
10842 Note that we *look* inside a SAVE_EXPR only to determine how it was
10843 calculated; it is not safe for fold to do much of anything else with the
10844 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
10845 at run time. For example, the latter example above *cannot* be implemented
10846 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
10847 evaluation time of the original SAVE_EXPR is not necessarily the same at
10848 the time the new expression is evaluated. The only optimization of this
10849 sort that would be valid is changing
10851 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
10855 SAVE_EXPR (I) * SAVE_EXPR (J)
10857 (where the same SAVE_EXPR (J) is used in the original and the
10858 transformed version). */
10861 multiple_of_p (tree type
, tree top
, tree bottom
)
10863 if (operand_equal_p (top
, bottom
, 0))
10866 if (TREE_CODE (type
) != INTEGER_TYPE
)
10869 switch (TREE_CODE (top
))
10872 /* Bitwise and provides a power of two multiple. If the mask is
10873 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
10874 if (!integer_pow2p (bottom
))
10879 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
10880 || multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
10884 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
10885 && multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
10888 if (TREE_CODE (TREE_OPERAND (top
, 1)) == INTEGER_CST
)
10892 op1
= TREE_OPERAND (top
, 1);
10893 /* const_binop may not detect overflow correctly,
10894 so check for it explicitly here. */
10895 if (TYPE_PRECISION (TREE_TYPE (size_one_node
))
10896 > TREE_INT_CST_LOW (op1
)
10897 && TREE_INT_CST_HIGH (op1
) == 0
10898 && 0 != (t1
= fold_convert (type
,
10899 const_binop (LSHIFT_EXPR
,
10902 && ! TREE_OVERFLOW (t1
))
10903 return multiple_of_p (type
, t1
, bottom
);
10908 /* Can't handle conversions from non-integral or wider integral type. */
10909 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top
, 0))) != INTEGER_TYPE
)
10910 || (TYPE_PRECISION (type
)
10911 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top
, 0)))))
10914 /* .. fall through ... */
10917 return multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
);
10920 if (TREE_CODE (bottom
) != INTEGER_CST
10921 || (TYPE_UNSIGNED (type
)
10922 && (tree_int_cst_sgn (top
) < 0
10923 || tree_int_cst_sgn (bottom
) < 0)))
10925 return integer_zerop (const_binop (TRUNC_MOD_EXPR
,
10933 /* Return true if `t' is known to be non-negative. */
10936 tree_expr_nonnegative_p (tree t
)
10938 if (TYPE_UNSIGNED (TREE_TYPE (t
)))
10941 switch (TREE_CODE (t
))
10944 /* We can't return 1 if flag_wrapv is set because
10945 ABS_EXPR<INT_MIN> = INT_MIN. */
10946 if (!(flag_wrapv
&& INTEGRAL_TYPE_P (TREE_TYPE (t
))))
10951 return tree_int_cst_sgn (t
) >= 0;
10954 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t
));
10957 if (FLOAT_TYPE_P (TREE_TYPE (t
)))
10958 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
10959 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
10961 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
10962 both unsigned and at least 2 bits shorter than the result. */
10963 if (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
10964 && TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
10965 && TREE_CODE (TREE_OPERAND (t
, 1)) == NOP_EXPR
)
10967 tree inner1
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
10968 tree inner2
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0));
10969 if (TREE_CODE (inner1
) == INTEGER_TYPE
&& TYPE_UNSIGNED (inner1
)
10970 && TREE_CODE (inner2
) == INTEGER_TYPE
&& TYPE_UNSIGNED (inner2
))
10972 unsigned int prec
= MAX (TYPE_PRECISION (inner1
),
10973 TYPE_PRECISION (inner2
)) + 1;
10974 return prec
< TYPE_PRECISION (TREE_TYPE (t
));
10980 if (FLOAT_TYPE_P (TREE_TYPE (t
)))
10982 /* x * x for floating point x is always non-negative. */
10983 if (operand_equal_p (TREE_OPERAND (t
, 0), TREE_OPERAND (t
, 1), 0))
10985 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
10986 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
10989 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
10990 both unsigned and their total bits is shorter than the result. */
10991 if (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
10992 && TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
10993 && TREE_CODE (TREE_OPERAND (t
, 1)) == NOP_EXPR
)
10995 tree inner1
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
10996 tree inner2
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0));
10997 if (TREE_CODE (inner1
) == INTEGER_TYPE
&& TYPE_UNSIGNED (inner1
)
10998 && TREE_CODE (inner2
) == INTEGER_TYPE
&& TYPE_UNSIGNED (inner2
))
10999 return TYPE_PRECISION (inner1
) + TYPE_PRECISION (inner2
)
11000 < TYPE_PRECISION (TREE_TYPE (t
));
11006 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
11007 || tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
11013 case TRUNC_DIV_EXPR
:
11014 case CEIL_DIV_EXPR
:
11015 case FLOOR_DIV_EXPR
:
11016 case ROUND_DIV_EXPR
:
11017 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
11018 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
11020 case TRUNC_MOD_EXPR
:
11021 case CEIL_MOD_EXPR
:
11022 case FLOOR_MOD_EXPR
:
11023 case ROUND_MOD_EXPR
:
11025 case NON_LVALUE_EXPR
:
11027 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
11029 case COMPOUND_EXPR
:
11031 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
11034 return tree_expr_nonnegative_p (expr_last (TREE_OPERAND (t
, 1)));
11037 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1))
11038 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 2));
11042 tree inner_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
11043 tree outer_type
= TREE_TYPE (t
);
11045 if (TREE_CODE (outer_type
) == REAL_TYPE
)
11047 if (TREE_CODE (inner_type
) == REAL_TYPE
)
11048 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
11049 if (TREE_CODE (inner_type
) == INTEGER_TYPE
)
11051 if (TYPE_UNSIGNED (inner_type
))
11053 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
11056 else if (TREE_CODE (outer_type
) == INTEGER_TYPE
)
11058 if (TREE_CODE (inner_type
) == REAL_TYPE
)
11059 return tree_expr_nonnegative_p (TREE_OPERAND (t
,0));
11060 if (TREE_CODE (inner_type
) == INTEGER_TYPE
)
11061 return TYPE_PRECISION (inner_type
) < TYPE_PRECISION (outer_type
)
11062 && TYPE_UNSIGNED (inner_type
);
11069 tree temp
= TARGET_EXPR_SLOT (t
);
11070 t
= TARGET_EXPR_INITIAL (t
);
11072 /* If the initializer is non-void, then it's a normal expression
11073 that will be assigned to the slot. */
11074 if (!VOID_TYPE_P (t
))
11075 return tree_expr_nonnegative_p (t
);
11077 /* Otherwise, the initializer sets the slot in some way. One common
11078 way is an assignment statement at the end of the initializer. */
11081 if (TREE_CODE (t
) == BIND_EXPR
)
11082 t
= expr_last (BIND_EXPR_BODY (t
));
11083 else if (TREE_CODE (t
) == TRY_FINALLY_EXPR
11084 || TREE_CODE (t
) == TRY_CATCH_EXPR
)
11085 t
= expr_last (TREE_OPERAND (t
, 0));
11086 else if (TREE_CODE (t
) == STATEMENT_LIST
)
11091 if (TREE_CODE (t
) == MODIFY_EXPR
11092 && TREE_OPERAND (t
, 0) == temp
)
11093 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
11100 tree fndecl
= get_callee_fndecl (t
);
11101 tree arglist
= TREE_OPERAND (t
, 1);
11102 if (fndecl
&& DECL_BUILT_IN_CLASS (fndecl
) == BUILT_IN_NORMAL
)
11103 switch (DECL_FUNCTION_CODE (fndecl
))
11105 CASE_FLT_FN (BUILT_IN_ACOS
):
11106 CASE_FLT_FN (BUILT_IN_ACOSH
):
11107 CASE_FLT_FN (BUILT_IN_CABS
):
11108 CASE_FLT_FN (BUILT_IN_COSH
):
11109 CASE_FLT_FN (BUILT_IN_ERFC
):
11110 CASE_FLT_FN (BUILT_IN_EXP
):
11111 CASE_FLT_FN (BUILT_IN_EXP10
):
11112 CASE_FLT_FN (BUILT_IN_EXP2
):
11113 CASE_FLT_FN (BUILT_IN_FABS
):
11114 CASE_FLT_FN (BUILT_IN_FDIM
):
11115 CASE_FLT_FN (BUILT_IN_HYPOT
):
11116 CASE_FLT_FN (BUILT_IN_POW10
):
11117 CASE_INT_FN (BUILT_IN_FFS
):
11118 CASE_INT_FN (BUILT_IN_PARITY
):
11119 CASE_INT_FN (BUILT_IN_POPCOUNT
):
11123 CASE_FLT_FN (BUILT_IN_SQRT
):
11124 /* sqrt(-0.0) is -0.0. */
11125 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t
))))
11127 return tree_expr_nonnegative_p (TREE_VALUE (arglist
));
11129 CASE_FLT_FN (BUILT_IN_ASINH
):
11130 CASE_FLT_FN (BUILT_IN_ATAN
):
11131 CASE_FLT_FN (BUILT_IN_ATANH
):
11132 CASE_FLT_FN (BUILT_IN_CBRT
):
11133 CASE_FLT_FN (BUILT_IN_CEIL
):
11134 CASE_FLT_FN (BUILT_IN_ERF
):
11135 CASE_FLT_FN (BUILT_IN_EXPM1
):
11136 CASE_FLT_FN (BUILT_IN_FLOOR
):
11137 CASE_FLT_FN (BUILT_IN_FMOD
):
11138 CASE_FLT_FN (BUILT_IN_FREXP
):
11139 CASE_FLT_FN (BUILT_IN_LCEIL
):
11140 CASE_FLT_FN (BUILT_IN_LDEXP
):
11141 CASE_FLT_FN (BUILT_IN_LFLOOR
):
11142 CASE_FLT_FN (BUILT_IN_LLCEIL
):
11143 CASE_FLT_FN (BUILT_IN_LLFLOOR
):
11144 CASE_FLT_FN (BUILT_IN_LLRINT
):
11145 CASE_FLT_FN (BUILT_IN_LLROUND
):
11146 CASE_FLT_FN (BUILT_IN_LRINT
):
11147 CASE_FLT_FN (BUILT_IN_LROUND
):
11148 CASE_FLT_FN (BUILT_IN_MODF
):
11149 CASE_FLT_FN (BUILT_IN_NEARBYINT
):
11150 CASE_FLT_FN (BUILT_IN_POW
):
11151 CASE_FLT_FN (BUILT_IN_RINT
):
11152 CASE_FLT_FN (BUILT_IN_ROUND
):
11153 CASE_FLT_FN (BUILT_IN_SIGNBIT
):
11154 CASE_FLT_FN (BUILT_IN_SINH
):
11155 CASE_FLT_FN (BUILT_IN_TANH
):
11156 CASE_FLT_FN (BUILT_IN_TRUNC
):
11157 /* True if the 1st argument is nonnegative. */
11158 return tree_expr_nonnegative_p (TREE_VALUE (arglist
));
11160 CASE_FLT_FN (BUILT_IN_FMAX
):
11161 /* True if the 1st OR 2nd arguments are nonnegative. */
11162 return tree_expr_nonnegative_p (TREE_VALUE (arglist
))
11163 || tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist
)));
11165 CASE_FLT_FN (BUILT_IN_FMIN
):
11166 /* True if the 1st AND 2nd arguments are nonnegative. */
11167 return tree_expr_nonnegative_p (TREE_VALUE (arglist
))
11168 && tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist
)));
11170 CASE_FLT_FN (BUILT_IN_COPYSIGN
):
11171 /* True if the 2nd argument is nonnegative. */
11172 return tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist
)));
11179 /* ... fall through ... */
11182 if (truth_value_p (TREE_CODE (t
)))
11183 /* Truth values evaluate to 0 or 1, which is nonnegative. */
11187 /* We don't know sign of `t', so be conservative and return false. */
11191 /* Return true when T is an address and is known to be nonzero.
11192 For floating point we further ensure that T is not denormal.
11193 Similar logic is present in nonzero_address in rtlanal.h. */
11196 tree_expr_nonzero_p (tree t
)
11198 tree type
= TREE_TYPE (t
);
11200 /* Doing something useful for floating point would need more work. */
11201 if (!INTEGRAL_TYPE_P (type
) && !POINTER_TYPE_P (type
))
11204 switch (TREE_CODE (t
))
11207 return tree_expr_nonzero_p (TREE_OPERAND (t
, 0));
11210 /* We used to test for !integer_zerop here. This does not work correctly
11211 if TREE_CONSTANT_OVERFLOW (t). */
11212 return (TREE_INT_CST_LOW (t
) != 0
11213 || TREE_INT_CST_HIGH (t
) != 0);
11216 if (!TYPE_UNSIGNED (type
) && !flag_wrapv
)
11218 /* With the presence of negative values it is hard
11219 to say something. */
11220 if (!tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
11221 || !tree_expr_nonnegative_p (TREE_OPERAND (t
, 1)))
11223 /* One of operands must be positive and the other non-negative. */
11224 return (tree_expr_nonzero_p (TREE_OPERAND (t
, 0))
11225 || tree_expr_nonzero_p (TREE_OPERAND (t
, 1)));
11230 if (!TYPE_UNSIGNED (type
) && !flag_wrapv
)
11232 return (tree_expr_nonzero_p (TREE_OPERAND (t
, 0))
11233 && tree_expr_nonzero_p (TREE_OPERAND (t
, 1)));
11239 tree inner_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
11240 tree outer_type
= TREE_TYPE (t
);
11242 return (TYPE_PRECISION (inner_type
) >= TYPE_PRECISION (outer_type
)
11243 && tree_expr_nonzero_p (TREE_OPERAND (t
, 0)));
11249 tree base
= get_base_address (TREE_OPERAND (t
, 0));
11254 /* Weak declarations may link to NULL. */
11255 if (VAR_OR_FUNCTION_DECL_P (base
))
11256 return !DECL_WEAK (base
);
11258 /* Constants are never weak. */
11259 if (CONSTANT_CLASS_P (base
))
11266 return (tree_expr_nonzero_p (TREE_OPERAND (t
, 1))
11267 && tree_expr_nonzero_p (TREE_OPERAND (t
, 2)));
11270 return (tree_expr_nonzero_p (TREE_OPERAND (t
, 0))
11271 && tree_expr_nonzero_p (TREE_OPERAND (t
, 1)));
11274 if (tree_expr_nonzero_p (TREE_OPERAND (t
, 0)))
11276 /* When both operands are nonzero, then MAX must be too. */
11277 if (tree_expr_nonzero_p (TREE_OPERAND (t
, 1)))
11280 /* MAX where operand 0 is positive is positive. */
11281 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
11283 /* MAX where operand 1 is positive is positive. */
11284 else if (tree_expr_nonzero_p (TREE_OPERAND (t
, 1))
11285 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1)))
11289 case COMPOUND_EXPR
:
11292 return tree_expr_nonzero_p (TREE_OPERAND (t
, 1));
11295 case NON_LVALUE_EXPR
:
11296 return tree_expr_nonzero_p (TREE_OPERAND (t
, 0));
11299 return tree_expr_nonzero_p (TREE_OPERAND (t
, 1))
11300 || tree_expr_nonzero_p (TREE_OPERAND (t
, 0));
11303 return alloca_call_p (t
);
11311 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
11312 attempt to fold the expression to a constant without modifying TYPE,
11315 If the expression could be simplified to a constant, then return
11316 the constant. If the expression would not be simplified to a
11317 constant, then return NULL_TREE. */
11320 fold_binary_to_constant (enum tree_code code
, tree type
, tree op0
, tree op1
)
11322 tree tem
= fold_binary (code
, type
, op0
, op1
);
11323 return (tem
&& TREE_CONSTANT (tem
)) ? tem
: NULL_TREE
;
11326 /* Given the components of a unary expression CODE, TYPE and OP0,
11327 attempt to fold the expression to a constant without modifying
11330 If the expression could be simplified to a constant, then return
11331 the constant. If the expression would not be simplified to a
11332 constant, then return NULL_TREE. */
11335 fold_unary_to_constant (enum tree_code code
, tree type
, tree op0
)
11337 tree tem
= fold_unary (code
, type
, op0
);
11338 return (tem
&& TREE_CONSTANT (tem
)) ? tem
: NULL_TREE
;
11341 /* If EXP represents referencing an element in a constant string
11342 (either via pointer arithmetic or array indexing), return the
11343 tree representing the value accessed, otherwise return NULL. */
11346 fold_read_from_constant_string (tree exp
)
11348 if (TREE_CODE (exp
) == INDIRECT_REF
|| TREE_CODE (exp
) == ARRAY_REF
)
11350 tree exp1
= TREE_OPERAND (exp
, 0);
11354 if (TREE_CODE (exp
) == INDIRECT_REF
)
11355 string
= string_constant (exp1
, &index
);
11358 tree low_bound
= array_ref_low_bound (exp
);
11359 index
= fold_convert (sizetype
, TREE_OPERAND (exp
, 1));
11361 /* Optimize the special-case of a zero lower bound.
11363 We convert the low_bound to sizetype to avoid some problems
11364 with constant folding. (E.g. suppose the lower bound is 1,
11365 and its mode is QI. Without the conversion,l (ARRAY
11366 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
11367 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
11368 if (! integer_zerop (low_bound
))
11369 index
= size_diffop (index
, fold_convert (sizetype
, low_bound
));
11375 && TREE_TYPE (exp
) == TREE_TYPE (TREE_TYPE (string
))
11376 && TREE_CODE (string
) == STRING_CST
11377 && TREE_CODE (index
) == INTEGER_CST
11378 && compare_tree_int (index
, TREE_STRING_LENGTH (string
)) < 0
11379 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string
))))
11381 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string
)))) == 1))
11382 return fold_convert (TREE_TYPE (exp
),
11383 build_int_cst (NULL_TREE
,
11384 (TREE_STRING_POINTER (string
)
11385 [TREE_INT_CST_LOW (index
)])));
11390 /* Return the tree for neg (ARG0) when ARG0 is known to be either
11391 an integer constant or real constant.
11393 TYPE is the type of the result. */
11396 fold_negate_const (tree arg0
, tree type
)
11398 tree t
= NULL_TREE
;
11400 switch (TREE_CODE (arg0
))
11404 unsigned HOST_WIDE_INT low
;
11405 HOST_WIDE_INT high
;
11406 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
11407 TREE_INT_CST_HIGH (arg0
),
11409 t
= build_int_cst_wide (type
, low
, high
);
11410 t
= force_fit_type (t
, 1,
11411 (overflow
| TREE_OVERFLOW (arg0
))
11412 && !TYPE_UNSIGNED (type
),
11413 TREE_CONSTANT_OVERFLOW (arg0
));
11418 t
= build_real (type
, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
11422 gcc_unreachable ();
11428 /* Return the tree for abs (ARG0) when ARG0 is known to be either
11429 an integer constant or real constant.
11431 TYPE is the type of the result. */
11434 fold_abs_const (tree arg0
, tree type
)
11436 tree t
= NULL_TREE
;
11438 switch (TREE_CODE (arg0
))
11441 /* If the value is unsigned, then the absolute value is
11442 the same as the ordinary value. */
11443 if (TYPE_UNSIGNED (type
))
11445 /* Similarly, if the value is non-negative. */
11446 else if (INT_CST_LT (integer_minus_one_node
, arg0
))
11448 /* If the value is negative, then the absolute value is
11452 unsigned HOST_WIDE_INT low
;
11453 HOST_WIDE_INT high
;
11454 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
11455 TREE_INT_CST_HIGH (arg0
),
11457 t
= build_int_cst_wide (type
, low
, high
);
11458 t
= force_fit_type (t
, -1, overflow
| TREE_OVERFLOW (arg0
),
11459 TREE_CONSTANT_OVERFLOW (arg0
));
11464 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0
)))
11465 t
= build_real (type
, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
11471 gcc_unreachable ();
11477 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
11478 constant. TYPE is the type of the result. */
11481 fold_not_const (tree arg0
, tree type
)
11483 tree t
= NULL_TREE
;
11485 gcc_assert (TREE_CODE (arg0
) == INTEGER_CST
);
11487 t
= build_int_cst_wide (type
,
11488 ~ TREE_INT_CST_LOW (arg0
),
11489 ~ TREE_INT_CST_HIGH (arg0
));
11490 t
= force_fit_type (t
, 0, TREE_OVERFLOW (arg0
),
11491 TREE_CONSTANT_OVERFLOW (arg0
));
11496 /* Given CODE, a relational operator, the target type, TYPE and two
11497 constant operands OP0 and OP1, return the result of the
11498 relational operation. If the result is not a compile time
11499 constant, then return NULL_TREE. */
11502 fold_relational_const (enum tree_code code
, tree type
, tree op0
, tree op1
)
11504 int result
, invert
;
11506 /* From here on, the only cases we handle are when the result is
11507 known to be a constant. */
11509 if (TREE_CODE (op0
) == REAL_CST
&& TREE_CODE (op1
) == REAL_CST
)
11511 const REAL_VALUE_TYPE
*c0
= TREE_REAL_CST_PTR (op0
);
11512 const REAL_VALUE_TYPE
*c1
= TREE_REAL_CST_PTR (op1
);
11514 /* Handle the cases where either operand is a NaN. */
11515 if (real_isnan (c0
) || real_isnan (c1
))
11525 case UNORDERED_EXPR
:
11539 if (flag_trapping_math
)
11545 gcc_unreachable ();
11548 return constant_boolean_node (result
, type
);
11551 return constant_boolean_node (real_compare (code
, c0
, c1
), type
);
11554 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
11556 To compute GT, swap the arguments and do LT.
11557 To compute GE, do LT and invert the result.
11558 To compute LE, swap the arguments, do LT and invert the result.
11559 To compute NE, do EQ and invert the result.
11561 Therefore, the code below must handle only EQ and LT. */
11563 if (code
== LE_EXPR
|| code
== GT_EXPR
)
11568 code
= swap_tree_comparison (code
);
11571 /* Note that it is safe to invert for real values here because we
11572 have already handled the one case that it matters. */
11575 if (code
== NE_EXPR
|| code
== GE_EXPR
)
11578 code
= invert_tree_comparison (code
, false);
11581 /* Compute a result for LT or EQ if args permit;
11582 Otherwise return T. */
11583 if (TREE_CODE (op0
) == INTEGER_CST
&& TREE_CODE (op1
) == INTEGER_CST
)
11585 if (code
== EQ_EXPR
)
11586 result
= tree_int_cst_equal (op0
, op1
);
11587 else if (TYPE_UNSIGNED (TREE_TYPE (op0
)))
11588 result
= INT_CST_LT_UNSIGNED (op0
, op1
);
11590 result
= INT_CST_LT (op0
, op1
);
11597 return constant_boolean_node (result
, type
);
11600 /* Build an expression for the a clean point containing EXPR with type TYPE.
11601 Don't build a cleanup point expression for EXPR which don't have side
11605 fold_build_cleanup_point_expr (tree type
, tree expr
)
11607 /* If the expression does not have side effects then we don't have to wrap
11608 it with a cleanup point expression. */
11609 if (!TREE_SIDE_EFFECTS (expr
))
11612 /* If the expression is a return, check to see if the expression inside the
11613 return has no side effects or the right hand side of the modify expression
11614 inside the return. If either don't have side effects set we don't need to
11615 wrap the expression in a cleanup point expression. Note we don't check the
11616 left hand side of the modify because it should always be a return decl. */
11617 if (TREE_CODE (expr
) == RETURN_EXPR
)
11619 tree op
= TREE_OPERAND (expr
, 0);
11620 if (!op
|| !TREE_SIDE_EFFECTS (op
))
11622 op
= TREE_OPERAND (op
, 1);
11623 if (!TREE_SIDE_EFFECTS (op
))
11627 return build1 (CLEANUP_POINT_EXPR
, type
, expr
);
11630 /* Build an expression for the address of T. Folds away INDIRECT_REF to
11631 avoid confusing the gimplify process. */
11634 build_fold_addr_expr_with_type (tree t
, tree ptrtype
)
11636 /* The size of the object is not relevant when talking about its address. */
11637 if (TREE_CODE (t
) == WITH_SIZE_EXPR
)
11638 t
= TREE_OPERAND (t
, 0);
11640 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
11641 if (TREE_CODE (t
) == INDIRECT_REF
11642 || TREE_CODE (t
) == MISALIGNED_INDIRECT_REF
)
11644 t
= TREE_OPERAND (t
, 0);
11645 if (TREE_TYPE (t
) != ptrtype
)
11646 t
= build1 (NOP_EXPR
, ptrtype
, t
);
11652 while (handled_component_p (base
))
11653 base
= TREE_OPERAND (base
, 0);
11655 TREE_ADDRESSABLE (base
) = 1;
11657 t
= build1 (ADDR_EXPR
, ptrtype
, t
);
11664 build_fold_addr_expr (tree t
)
11666 return build_fold_addr_expr_with_type (t
, build_pointer_type (TREE_TYPE (t
)));
11669 /* Given a pointer value OP0 and a type TYPE, return a simplified version
11670 of an indirection through OP0, or NULL_TREE if no simplification is
11674 fold_indirect_ref_1 (tree type
, tree op0
)
11680 subtype
= TREE_TYPE (sub
);
11681 if (!POINTER_TYPE_P (subtype
))
11684 if (TREE_CODE (sub
) == ADDR_EXPR
)
11686 tree op
= TREE_OPERAND (sub
, 0);
11687 tree optype
= TREE_TYPE (op
);
11688 /* *&p => p; make sure to handle *&"str"[cst] here. */
11689 if (type
== optype
)
11691 tree fop
= fold_read_from_constant_string (op
);
11697 /* *(foo *)&fooarray => fooarray[0] */
11698 else if (TREE_CODE (optype
) == ARRAY_TYPE
11699 && type
== TREE_TYPE (optype
))
11701 tree type_domain
= TYPE_DOMAIN (optype
);
11702 tree min_val
= size_zero_node
;
11703 if (type_domain
&& TYPE_MIN_VALUE (type_domain
))
11704 min_val
= TYPE_MIN_VALUE (type_domain
);
11705 return build4 (ARRAY_REF
, type
, op
, min_val
, NULL_TREE
, NULL_TREE
);
11709 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
11710 if (TREE_CODE (TREE_TYPE (subtype
)) == ARRAY_TYPE
11711 && type
== TREE_TYPE (TREE_TYPE (subtype
)))
11714 tree min_val
= size_zero_node
;
11715 sub
= build_fold_indirect_ref (sub
);
11716 type_domain
= TYPE_DOMAIN (TREE_TYPE (sub
));
11717 if (type_domain
&& TYPE_MIN_VALUE (type_domain
))
11718 min_val
= TYPE_MIN_VALUE (type_domain
);
11719 return build4 (ARRAY_REF
, type
, sub
, min_val
, NULL_TREE
, NULL_TREE
);
11725 /* Builds an expression for an indirection through T, simplifying some
11729 build_fold_indirect_ref (tree t
)
11731 tree type
= TREE_TYPE (TREE_TYPE (t
));
11732 tree sub
= fold_indirect_ref_1 (type
, t
);
11737 return build1 (INDIRECT_REF
, type
, t
);
11740 /* Given an INDIRECT_REF T, return either T or a simplified version. */
11743 fold_indirect_ref (tree t
)
11745 tree sub
= fold_indirect_ref_1 (TREE_TYPE (t
), TREE_OPERAND (t
, 0));
11753 /* Strip non-trapping, non-side-effecting tree nodes from an expression
11754 whose result is ignored. The type of the returned tree need not be
11755 the same as the original expression. */
11758 fold_ignored_result (tree t
)
11760 if (!TREE_SIDE_EFFECTS (t
))
11761 return integer_zero_node
;
11764 switch (TREE_CODE_CLASS (TREE_CODE (t
)))
11767 t
= TREE_OPERAND (t
, 0);
11771 case tcc_comparison
:
11772 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 1)))
11773 t
= TREE_OPERAND (t
, 0);
11774 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 0)))
11775 t
= TREE_OPERAND (t
, 1);
11780 case tcc_expression
:
11781 switch (TREE_CODE (t
))
11783 case COMPOUND_EXPR
:
11784 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 1)))
11786 t
= TREE_OPERAND (t
, 0);
11790 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 1))
11791 || TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 2)))
11793 t
= TREE_OPERAND (t
, 0);
11806 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
11807 This can only be applied to objects of a sizetype. */
11810 round_up (tree value
, int divisor
)
11812 tree div
= NULL_TREE
;
11814 gcc_assert (divisor
> 0);
11818 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
11819 have to do anything. Only do this when we are not given a const,
11820 because in that case, this check is more expensive than just
11822 if (TREE_CODE (value
) != INTEGER_CST
)
11824 div
= build_int_cst (TREE_TYPE (value
), divisor
);
11826 if (multiple_of_p (TREE_TYPE (value
), value
, div
))
11830 /* If divisor is a power of two, simplify this to bit manipulation. */
11831 if (divisor
== (divisor
& -divisor
))
11835 t
= build_int_cst (TREE_TYPE (value
), divisor
- 1);
11836 value
= size_binop (PLUS_EXPR
, value
, t
);
11837 t
= build_int_cst (TREE_TYPE (value
), -divisor
);
11838 value
= size_binop (BIT_AND_EXPR
, value
, t
);
11843 div
= build_int_cst (TREE_TYPE (value
), divisor
);
11844 value
= size_binop (CEIL_DIV_EXPR
, value
, div
);
11845 value
= size_binop (MULT_EXPR
, value
, div
);
11851 /* Likewise, but round down. */
11854 round_down (tree value
, int divisor
)
11856 tree div
= NULL_TREE
;
11858 gcc_assert (divisor
> 0);
11862 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
11863 have to do anything. Only do this when we are not given a const,
11864 because in that case, this check is more expensive than just
11866 if (TREE_CODE (value
) != INTEGER_CST
)
11868 div
= build_int_cst (TREE_TYPE (value
), divisor
);
11870 if (multiple_of_p (TREE_TYPE (value
), value
, div
))
11874 /* If divisor is a power of two, simplify this to bit manipulation. */
11875 if (divisor
== (divisor
& -divisor
))
11879 t
= build_int_cst (TREE_TYPE (value
), -divisor
);
11880 value
= size_binop (BIT_AND_EXPR
, value
, t
);
11885 div
= build_int_cst (TREE_TYPE (value
), divisor
);
11886 value
= size_binop (FLOOR_DIV_EXPR
, value
, div
);
11887 value
= size_binop (MULT_EXPR
, value
, div
);
11893 /* Returns the pointer to the base of the object addressed by EXP and
11894 extracts the information about the offset of the access, storing it
11895 to PBITPOS and POFFSET. */
11898 split_address_to_core_and_offset (tree exp
,
11899 HOST_WIDE_INT
*pbitpos
, tree
*poffset
)
11902 enum machine_mode mode
;
11903 int unsignedp
, volatilep
;
11904 HOST_WIDE_INT bitsize
;
11906 if (TREE_CODE (exp
) == ADDR_EXPR
)
11908 core
= get_inner_reference (TREE_OPERAND (exp
, 0), &bitsize
, pbitpos
,
11909 poffset
, &mode
, &unsignedp
, &volatilep
,
11911 core
= build_fold_addr_expr (core
);
11917 *poffset
= NULL_TREE
;
11923 /* Returns true if addresses of E1 and E2 differ by a constant, false
11924 otherwise. If they do, E1 - E2 is stored in *DIFF. */
11927 ptr_difference_const (tree e1
, tree e2
, HOST_WIDE_INT
*diff
)
11930 HOST_WIDE_INT bitpos1
, bitpos2
;
11931 tree toffset1
, toffset2
, tdiff
, type
;
11933 core1
= split_address_to_core_and_offset (e1
, &bitpos1
, &toffset1
);
11934 core2
= split_address_to_core_and_offset (e2
, &bitpos2
, &toffset2
);
11936 if (bitpos1
% BITS_PER_UNIT
!= 0
11937 || bitpos2
% BITS_PER_UNIT
!= 0
11938 || !operand_equal_p (core1
, core2
, 0))
11941 if (toffset1
&& toffset2
)
11943 type
= TREE_TYPE (toffset1
);
11944 if (type
!= TREE_TYPE (toffset2
))
11945 toffset2
= fold_convert (type
, toffset2
);
11947 tdiff
= fold_build2 (MINUS_EXPR
, type
, toffset1
, toffset2
);
11948 if (!cst_and_fits_in_hwi (tdiff
))
11951 *diff
= int_cst_value (tdiff
);
11953 else if (toffset1
|| toffset2
)
11955 /* If only one of the offsets is non-constant, the difference cannot
11962 *diff
+= (bitpos1
- bitpos2
) / BITS_PER_UNIT
;
11966 /* Simplify the floating point expression EXP when the sign of the
11967 result is not significant. Return NULL_TREE if no simplification
11971 fold_strip_sign_ops (tree exp
)
11975 switch (TREE_CODE (exp
))
11979 arg0
= fold_strip_sign_ops (TREE_OPERAND (exp
, 0));
11980 return arg0
? arg0
: TREE_OPERAND (exp
, 0);
11984 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp
))))
11986 arg0
= fold_strip_sign_ops (TREE_OPERAND (exp
, 0));
11987 arg1
= fold_strip_sign_ops (TREE_OPERAND (exp
, 1));
11988 if (arg0
!= NULL_TREE
|| arg1
!= NULL_TREE
)
11989 return fold_build2 (TREE_CODE (exp
), TREE_TYPE (exp
),
11990 arg0
? arg0
: TREE_OPERAND (exp
, 0),
11991 arg1
? arg1
: TREE_OPERAND (exp
, 1));