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 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /*@@ This file should be rewritten to use an arbitrary precision
23 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
24 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
25 @@ The routines that translate from the ap rep should
26 @@ warn if precision et. al. is lost.
27 @@ This would also make life easier when this technology is used
28 @@ for cross-compilers. */
30 /* The entry points in this file are fold, size_int_wide, size_binop
33 fold takes a tree as argument and returns a simplified tree.
35 size_binop takes a tree code for an arithmetic operation
36 and two operands that are trees, and produces a tree for the
37 result, assuming the type comes from `sizetype'.
39 size_int takes an integer value, and creates a tree constant
40 with type from `sizetype'.
42 force_fit_type takes a constant and prior overflow indicator, and
43 forces the value to fit the type. It returns an overflow indicator. */
47 #include "coretypes.h"
58 #include "langhooks.h"
60 static void encode
PARAMS ((HOST_WIDE_INT
*,
61 unsigned HOST_WIDE_INT
,
63 static void decode
PARAMS ((HOST_WIDE_INT
*,
64 unsigned HOST_WIDE_INT
*,
66 static bool negate_expr_p
PARAMS ((tree
));
67 static tree negate_expr
PARAMS ((tree
));
68 static tree split_tree
PARAMS ((tree
, enum tree_code
, tree
*, tree
*,
70 static tree associate_trees
PARAMS ((tree
, tree
, enum tree_code
, tree
));
71 static tree int_const_binop
PARAMS ((enum tree_code
, tree
, tree
, int));
72 static tree const_binop
PARAMS ((enum tree_code
, tree
, tree
, int));
73 static hashval_t size_htab_hash
PARAMS ((const void *));
74 static int size_htab_eq
PARAMS ((const void *, const void *));
75 static tree fold_convert
PARAMS ((tree
, tree
));
76 static enum tree_code invert_tree_comparison
PARAMS ((enum tree_code
));
77 static enum tree_code swap_tree_comparison
PARAMS ((enum tree_code
));
78 static int comparison_to_compcode
PARAMS ((enum tree_code
));
79 static enum tree_code compcode_to_comparison
PARAMS ((int));
80 static int truth_value_p
PARAMS ((enum tree_code
));
81 static int operand_equal_for_comparison_p
PARAMS ((tree
, tree
, tree
));
82 static int twoval_comparison_p
PARAMS ((tree
, tree
*, tree
*, int *));
83 static tree eval_subst
PARAMS ((tree
, tree
, tree
, tree
, tree
));
84 static tree pedantic_omit_one_operand
PARAMS ((tree
, tree
, tree
));
85 static tree distribute_bit_expr
PARAMS ((enum tree_code
, tree
, tree
, tree
));
86 static tree make_bit_field_ref
PARAMS ((tree
, tree
, int, int, int));
87 static tree optimize_bit_field_compare
PARAMS ((enum tree_code
, tree
,
89 static tree decode_field_reference
PARAMS ((tree
, HOST_WIDE_INT
*,
91 enum machine_mode
*, int *,
92 int *, tree
*, tree
*));
93 static int all_ones_mask_p
PARAMS ((tree
, int));
94 static tree sign_bit_p
PARAMS ((tree
, tree
));
95 static int simple_operand_p
PARAMS ((tree
));
96 static tree range_binop
PARAMS ((enum tree_code
, tree
, tree
, int,
98 static tree make_range
PARAMS ((tree
, int *, tree
*, tree
*));
99 static tree build_range_check
PARAMS ((tree
, tree
, int, tree
, tree
));
100 static int merge_ranges
PARAMS ((int *, tree
*, tree
*, int, tree
, tree
,
102 static tree fold_range_test
PARAMS ((tree
));
103 static tree unextend
PARAMS ((tree
, int, int, tree
));
104 static tree fold_truthop
PARAMS ((enum tree_code
, tree
, tree
, tree
));
105 static tree optimize_minmax_comparison
PARAMS ((tree
));
106 static tree extract_muldiv
PARAMS ((tree
, tree
, enum tree_code
, tree
));
107 static tree extract_muldiv_1
PARAMS ((tree
, tree
, enum tree_code
, tree
));
108 static tree strip_compound_expr
PARAMS ((tree
, tree
));
109 static int multiple_of_p
PARAMS ((tree
, tree
, tree
));
110 static tree constant_boolean_node
PARAMS ((int, tree
));
111 static int count_cond
PARAMS ((tree
, int));
112 static tree fold_binary_op_with_conditional_arg
113 PARAMS ((enum tree_code
, tree
, tree
, tree
, int));
114 static bool fold_real_zero_addition_p
PARAMS ((tree
, tree
, int));
115 static tree fold_mathfn_compare
PARAMS ((enum built_in_function
,
116 enum tree_code
, tree
, tree
, tree
));
117 static tree fold_inf_compare
PARAMS ((enum tree_code
, tree
, tree
, tree
));
119 /* The following constants represent a bit based encoding of GCC's
120 comparison operators. This encoding simplifies transformations
121 on relational comparison operators, such as AND and OR. */
122 #define COMPCODE_FALSE 0
123 #define COMPCODE_LT 1
124 #define COMPCODE_EQ 2
125 #define COMPCODE_LE 3
126 #define COMPCODE_GT 4
127 #define COMPCODE_NE 5
128 #define COMPCODE_GE 6
129 #define COMPCODE_TRUE 7
131 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
132 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
133 and SUM1. Then this yields nonzero if overflow occurred during the
136 Overflow occurs if A and B have the same sign, but A and SUM differ in
137 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
139 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
141 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
142 We do that by representing the two-word integer in 4 words, with only
143 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
144 number. The value of the word is LOWPART + HIGHPART * BASE. */
147 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
148 #define HIGHPART(x) \
149 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
150 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
152 /* Unpack a two-word integer into 4 words.
153 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
154 WORDS points to the array of HOST_WIDE_INTs. */
157 encode (words
, low
, hi
)
158 HOST_WIDE_INT
*words
;
159 unsigned HOST_WIDE_INT low
;
162 words
[0] = LOWPART (low
);
163 words
[1] = HIGHPART (low
);
164 words
[2] = LOWPART (hi
);
165 words
[3] = HIGHPART (hi
);
168 /* Pack an array of 4 words into a two-word integer.
169 WORDS points to the array of words.
170 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
173 decode (words
, low
, hi
)
174 HOST_WIDE_INT
*words
;
175 unsigned HOST_WIDE_INT
*low
;
178 *low
= words
[0] + words
[1] * BASE
;
179 *hi
= words
[2] + words
[3] * BASE
;
182 /* Make the integer constant T valid for its type by setting to 0 or 1 all
183 the bits in the constant that don't belong in the type.
185 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
186 nonzero, a signed overflow has already occurred in calculating T, so
190 force_fit_type (t
, overflow
)
194 unsigned HOST_WIDE_INT low
;
198 if (TREE_CODE (t
) == REAL_CST
)
200 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
201 Consider doing it via real_convert now. */
205 else if (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
)))
214 prec
= TYPE_PRECISION (TREE_TYPE (t
));
216 /* First clear all bits that are beyond the type's precision. */
218 if (prec
== 2 * HOST_BITS_PER_WIDE_INT
)
220 else if (prec
> HOST_BITS_PER_WIDE_INT
)
221 TREE_INT_CST_HIGH (t
)
222 &= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
225 TREE_INT_CST_HIGH (t
) = 0;
226 if (prec
< HOST_BITS_PER_WIDE_INT
)
227 TREE_INT_CST_LOW (t
) &= ~((unsigned HOST_WIDE_INT
) (-1) << prec
);
230 /* Unsigned types do not suffer sign extension or overflow unless they
232 if (TREE_UNSIGNED (TREE_TYPE (t
))
233 && ! (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
234 && TYPE_IS_SIZETYPE (TREE_TYPE (t
))))
237 /* If the value's sign bit is set, extend the sign. */
238 if (prec
!= 2 * HOST_BITS_PER_WIDE_INT
239 && (prec
> HOST_BITS_PER_WIDE_INT
240 ? 0 != (TREE_INT_CST_HIGH (t
)
242 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)))
243 : 0 != (TREE_INT_CST_LOW (t
)
244 & ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1)))))
246 /* Value is negative:
247 set to 1 all the bits that are outside this type's precision. */
248 if (prec
> HOST_BITS_PER_WIDE_INT
)
249 TREE_INT_CST_HIGH (t
)
250 |= ((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
253 TREE_INT_CST_HIGH (t
) = -1;
254 if (prec
< HOST_BITS_PER_WIDE_INT
)
255 TREE_INT_CST_LOW (t
) |= ((unsigned HOST_WIDE_INT
) (-1) << prec
);
259 /* Return nonzero if signed overflow occurred. */
261 ((overflow
| (low
^ TREE_INT_CST_LOW (t
)) | (high
^ TREE_INT_CST_HIGH (t
)))
265 /* Add two doubleword integers with doubleword result.
266 Each argument is given as two `HOST_WIDE_INT' pieces.
267 One argument is L1 and H1; the other, L2 and H2.
268 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
271 add_double (l1
, h1
, l2
, h2
, lv
, hv
)
272 unsigned HOST_WIDE_INT l1
, l2
;
273 HOST_WIDE_INT h1
, h2
;
274 unsigned HOST_WIDE_INT
*lv
;
277 unsigned HOST_WIDE_INT l
;
281 h
= h1
+ h2
+ (l
< l1
);
285 return OVERFLOW_SUM_SIGN (h1
, h2
, h
);
288 /* Negate a doubleword integer with doubleword result.
289 Return nonzero if the operation overflows, assuming it's signed.
290 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
291 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
294 neg_double (l1
, h1
, lv
, hv
)
295 unsigned HOST_WIDE_INT l1
;
297 unsigned HOST_WIDE_INT
*lv
;
304 return (*hv
& h1
) < 0;
314 /* Multiply two doubleword integers with doubleword result.
315 Return nonzero if the operation overflows, assuming it's signed.
316 Each argument is given as two `HOST_WIDE_INT' pieces.
317 One argument is L1 and H1; the other, L2 and H2.
318 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
321 mul_double (l1
, h1
, l2
, h2
, lv
, hv
)
322 unsigned HOST_WIDE_INT l1
, l2
;
323 HOST_WIDE_INT h1
, h2
;
324 unsigned HOST_WIDE_INT
*lv
;
327 HOST_WIDE_INT arg1
[4];
328 HOST_WIDE_INT arg2
[4];
329 HOST_WIDE_INT prod
[4 * 2];
330 unsigned HOST_WIDE_INT carry
;
332 unsigned HOST_WIDE_INT toplow
, neglow
;
333 HOST_WIDE_INT tophigh
, neghigh
;
335 encode (arg1
, l1
, h1
);
336 encode (arg2
, l2
, h2
);
338 memset ((char *) prod
, 0, sizeof prod
);
340 for (i
= 0; i
< 4; i
++)
343 for (j
= 0; j
< 4; j
++)
346 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
347 carry
+= arg1
[i
] * arg2
[j
];
348 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
350 prod
[k
] = LOWPART (carry
);
351 carry
= HIGHPART (carry
);
356 decode (prod
, lv
, hv
); /* This ignores prod[4] through prod[4*2-1] */
358 /* Check for overflow by calculating the top half of the answer in full;
359 it should agree with the low half's sign bit. */
360 decode (prod
+ 4, &toplow
, &tophigh
);
363 neg_double (l2
, h2
, &neglow
, &neghigh
);
364 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
368 neg_double (l1
, h1
, &neglow
, &neghigh
);
369 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
371 return (*hv
< 0 ? ~(toplow
& tophigh
) : toplow
| tophigh
) != 0;
374 /* Shift the doubleword integer in L1, H1 left by COUNT places
375 keeping only PREC bits of result.
376 Shift right if COUNT is negative.
377 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
378 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
381 lshift_double (l1
, h1
, count
, prec
, lv
, hv
, arith
)
382 unsigned HOST_WIDE_INT l1
;
383 HOST_WIDE_INT h1
, count
;
385 unsigned HOST_WIDE_INT
*lv
;
389 unsigned HOST_WIDE_INT signmask
;
393 rshift_double (l1
, h1
, -count
, prec
, lv
, hv
, arith
);
397 #ifdef SHIFT_COUNT_TRUNCATED
398 if (SHIFT_COUNT_TRUNCATED
)
402 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
404 /* Shifting by the host word size is undefined according to the
405 ANSI standard, so we must handle this as a special case. */
409 else if (count
>= HOST_BITS_PER_WIDE_INT
)
411 *hv
= l1
<< (count
- HOST_BITS_PER_WIDE_INT
);
416 *hv
= (((unsigned HOST_WIDE_INT
) h1
<< count
)
417 | (l1
>> (HOST_BITS_PER_WIDE_INT
- count
- 1) >> 1));
421 /* Sign extend all bits that are beyond the precision. */
423 signmask
= -((prec
> HOST_BITS_PER_WIDE_INT
424 ? ((unsigned HOST_WIDE_INT
) *hv
425 >> (prec
- HOST_BITS_PER_WIDE_INT
- 1))
426 : (*lv
>> (prec
- 1))) & 1);
428 if (prec
>= 2 * HOST_BITS_PER_WIDE_INT
)
430 else if (prec
>= HOST_BITS_PER_WIDE_INT
)
432 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
433 *hv
|= signmask
<< (prec
- HOST_BITS_PER_WIDE_INT
);
438 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << prec
);
439 *lv
|= signmask
<< prec
;
443 /* Shift the doubleword integer in L1, H1 right by COUNT places
444 keeping only PREC bits of result. COUNT must be positive.
445 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
446 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
449 rshift_double (l1
, h1
, count
, prec
, lv
, hv
, arith
)
450 unsigned HOST_WIDE_INT l1
;
451 HOST_WIDE_INT h1
, count
;
453 unsigned HOST_WIDE_INT
*lv
;
457 unsigned HOST_WIDE_INT signmask
;
460 ? -((unsigned HOST_WIDE_INT
) h1
>> (HOST_BITS_PER_WIDE_INT
- 1))
463 #ifdef SHIFT_COUNT_TRUNCATED
464 if (SHIFT_COUNT_TRUNCATED
)
468 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
470 /* Shifting by the host word size is undefined according to the
471 ANSI standard, so we must handle this as a special case. */
475 else if (count
>= HOST_BITS_PER_WIDE_INT
)
478 *lv
= (unsigned HOST_WIDE_INT
) h1
>> (count
- HOST_BITS_PER_WIDE_INT
);
482 *hv
= (unsigned HOST_WIDE_INT
) h1
>> count
;
484 | ((unsigned HOST_WIDE_INT
) h1
<< (HOST_BITS_PER_WIDE_INT
- count
- 1) << 1));
487 /* Zero / sign extend all bits that are beyond the precision. */
489 if (count
>= (HOST_WIDE_INT
)prec
)
494 else if ((prec
- count
) >= 2 * HOST_BITS_PER_WIDE_INT
)
496 else if ((prec
- count
) >= HOST_BITS_PER_WIDE_INT
)
498 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- count
- HOST_BITS_PER_WIDE_INT
));
499 *hv
|= signmask
<< (prec
- count
- HOST_BITS_PER_WIDE_INT
);
504 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << (prec
- count
));
505 *lv
|= signmask
<< (prec
- count
);
509 /* Rotate the doubleword integer in L1, H1 left by COUNT places
510 keeping only PREC bits of result.
511 Rotate right if COUNT is negative.
512 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
515 lrotate_double (l1
, h1
, count
, prec
, lv
, hv
)
516 unsigned HOST_WIDE_INT l1
;
517 HOST_WIDE_INT h1
, count
;
519 unsigned HOST_WIDE_INT
*lv
;
522 unsigned HOST_WIDE_INT s1l
, s2l
;
523 HOST_WIDE_INT s1h
, s2h
;
529 lshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
530 rshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
535 /* Rotate the doubleword integer in L1, H1 left by COUNT places
536 keeping only PREC bits of result. COUNT must be positive.
537 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
540 rrotate_double (l1
, h1
, count
, prec
, lv
, hv
)
541 unsigned HOST_WIDE_INT l1
;
542 HOST_WIDE_INT h1
, count
;
544 unsigned HOST_WIDE_INT
*lv
;
547 unsigned HOST_WIDE_INT s1l
, s2l
;
548 HOST_WIDE_INT s1h
, s2h
;
554 rshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
555 lshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
560 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
561 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
562 CODE is a tree code for a kind of division, one of
563 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
565 It controls how the quotient is rounded to an integer.
566 Return nonzero if the operation overflows.
567 UNS nonzero says do unsigned division. */
570 div_and_round_double (code
, uns
,
571 lnum_orig
, hnum_orig
, lden_orig
, hden_orig
,
572 lquo
, hquo
, lrem
, hrem
)
575 unsigned HOST_WIDE_INT lnum_orig
; /* num == numerator == dividend */
576 HOST_WIDE_INT hnum_orig
;
577 unsigned HOST_WIDE_INT lden_orig
; /* den == denominator == divisor */
578 HOST_WIDE_INT hden_orig
;
579 unsigned HOST_WIDE_INT
*lquo
, *lrem
;
580 HOST_WIDE_INT
*hquo
, *hrem
;
583 HOST_WIDE_INT num
[4 + 1]; /* extra element for scaling. */
584 HOST_WIDE_INT den
[4], quo
[4];
586 unsigned HOST_WIDE_INT work
;
587 unsigned HOST_WIDE_INT carry
= 0;
588 unsigned HOST_WIDE_INT lnum
= lnum_orig
;
589 HOST_WIDE_INT hnum
= hnum_orig
;
590 unsigned HOST_WIDE_INT lden
= lden_orig
;
591 HOST_WIDE_INT hden
= hden_orig
;
594 if (hden
== 0 && lden
== 0)
595 overflow
= 1, lden
= 1;
597 /* calculate quotient sign and convert operands to unsigned. */
603 /* (minimum integer) / (-1) is the only overflow case. */
604 if (neg_double (lnum
, hnum
, &lnum
, &hnum
)
605 && ((HOST_WIDE_INT
) lden
& hden
) == -1)
611 neg_double (lden
, hden
, &lden
, &hden
);
615 if (hnum
== 0 && hden
== 0)
616 { /* single precision */
618 /* This unsigned division rounds toward zero. */
624 { /* trivial case: dividend < divisor */
625 /* hden != 0 already checked. */
632 memset ((char *) quo
, 0, sizeof quo
);
634 memset ((char *) num
, 0, sizeof num
); /* to zero 9th element */
635 memset ((char *) den
, 0, sizeof den
);
637 encode (num
, lnum
, hnum
);
638 encode (den
, lden
, hden
);
640 /* Special code for when the divisor < BASE. */
641 if (hden
== 0 && lden
< (unsigned HOST_WIDE_INT
) BASE
)
643 /* hnum != 0 already checked. */
644 for (i
= 4 - 1; i
>= 0; i
--)
646 work
= num
[i
] + carry
* BASE
;
647 quo
[i
] = work
/ lden
;
653 /* Full double precision division,
654 with thanks to Don Knuth's "Seminumerical Algorithms". */
655 int num_hi_sig
, den_hi_sig
;
656 unsigned HOST_WIDE_INT quo_est
, scale
;
658 /* Find the highest nonzero divisor digit. */
659 for (i
= 4 - 1;; i
--)
666 /* Insure that the first digit of the divisor is at least BASE/2.
667 This is required by the quotient digit estimation algorithm. */
669 scale
= BASE
/ (den
[den_hi_sig
] + 1);
671 { /* scale divisor and dividend */
673 for (i
= 0; i
<= 4 - 1; i
++)
675 work
= (num
[i
] * scale
) + carry
;
676 num
[i
] = LOWPART (work
);
677 carry
= HIGHPART (work
);
682 for (i
= 0; i
<= 4 - 1; i
++)
684 work
= (den
[i
] * scale
) + carry
;
685 den
[i
] = LOWPART (work
);
686 carry
= HIGHPART (work
);
687 if (den
[i
] != 0) den_hi_sig
= i
;
694 for (i
= num_hi_sig
- den_hi_sig
- 1; i
>= 0; i
--)
696 /* Guess the next quotient digit, quo_est, by dividing the first
697 two remaining dividend digits by the high order quotient digit.
698 quo_est is never low and is at most 2 high. */
699 unsigned HOST_WIDE_INT tmp
;
701 num_hi_sig
= i
+ den_hi_sig
+ 1;
702 work
= num
[num_hi_sig
] * BASE
+ num
[num_hi_sig
- 1];
703 if (num
[num_hi_sig
] != den
[den_hi_sig
])
704 quo_est
= work
/ den
[den_hi_sig
];
708 /* Refine quo_est so it's usually correct, and at most one high. */
709 tmp
= work
- quo_est
* den
[den_hi_sig
];
711 && (den
[den_hi_sig
- 1] * quo_est
712 > (tmp
* BASE
+ num
[num_hi_sig
- 2])))
715 /* Try QUO_EST as the quotient digit, by multiplying the
716 divisor by QUO_EST and subtracting from the remaining dividend.
717 Keep in mind that QUO_EST is the I - 1st digit. */
720 for (j
= 0; j
<= den_hi_sig
; j
++)
722 work
= quo_est
* den
[j
] + carry
;
723 carry
= HIGHPART (work
);
724 work
= num
[i
+ j
] - LOWPART (work
);
725 num
[i
+ j
] = LOWPART (work
);
726 carry
+= HIGHPART (work
) != 0;
729 /* If quo_est was high by one, then num[i] went negative and
730 we need to correct things. */
731 if (num
[num_hi_sig
] < (HOST_WIDE_INT
) carry
)
734 carry
= 0; /* add divisor back in */
735 for (j
= 0; j
<= den_hi_sig
; j
++)
737 work
= num
[i
+ j
] + den
[j
] + carry
;
738 carry
= HIGHPART (work
);
739 num
[i
+ j
] = LOWPART (work
);
742 num
[num_hi_sig
] += carry
;
745 /* Store the quotient digit. */
750 decode (quo
, lquo
, hquo
);
753 /* if result is negative, make it so. */
755 neg_double (*lquo
, *hquo
, lquo
, hquo
);
757 /* compute trial remainder: rem = num - (quo * den) */
758 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
759 neg_double (*lrem
, *hrem
, lrem
, hrem
);
760 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
765 case TRUNC_MOD_EXPR
: /* round toward zero */
766 case EXACT_DIV_EXPR
: /* for this one, it shouldn't matter */
770 case FLOOR_MOD_EXPR
: /* round toward negative infinity */
771 if (quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio < 0 && rem != 0 */
774 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1,
782 case CEIL_MOD_EXPR
: /* round toward positive infinity */
783 if (!quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio > 0 && rem != 0 */
785 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
793 case ROUND_MOD_EXPR
: /* round to closest integer */
795 unsigned HOST_WIDE_INT labs_rem
= *lrem
;
796 HOST_WIDE_INT habs_rem
= *hrem
;
797 unsigned HOST_WIDE_INT labs_den
= lden
, ltwice
;
798 HOST_WIDE_INT habs_den
= hden
, htwice
;
800 /* Get absolute values */
802 neg_double (*lrem
, *hrem
, &labs_rem
, &habs_rem
);
804 neg_double (lden
, hden
, &labs_den
, &habs_den
);
806 /* If (2 * abs (lrem) >= abs (lden)) */
807 mul_double ((HOST_WIDE_INT
) 2, (HOST_WIDE_INT
) 0,
808 labs_rem
, habs_rem
, <wice
, &htwice
);
810 if (((unsigned HOST_WIDE_INT
) habs_den
811 < (unsigned HOST_WIDE_INT
) htwice
)
812 || (((unsigned HOST_WIDE_INT
) habs_den
813 == (unsigned HOST_WIDE_INT
) htwice
)
814 && (labs_den
< ltwice
)))
818 add_double (*lquo
, *hquo
,
819 (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1, lquo
, hquo
);
822 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
834 /* compute true remainder: rem = num - (quo * den) */
835 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
836 neg_double (*lrem
, *hrem
, lrem
, hrem
);
837 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
841 /* Determine whether an expression T can be cheaply negated using
842 the function negate_expr. */
848 unsigned HOST_WIDE_INT val
;
855 type
= TREE_TYPE (t
);
858 switch (TREE_CODE (t
))
861 if (TREE_UNSIGNED (type
))
864 /* Check that -CST will not overflow type. */
865 prec
= TYPE_PRECISION (type
);
866 if (prec
> HOST_BITS_PER_WIDE_INT
)
868 if (TREE_INT_CST_LOW (t
) != 0)
870 prec
-= HOST_BITS_PER_WIDE_INT
;
871 val
= TREE_INT_CST_HIGH (t
);
874 val
= TREE_INT_CST_LOW (t
);
875 if (prec
< HOST_BITS_PER_WIDE_INT
)
876 val
&= ((unsigned HOST_WIDE_INT
) 1 << prec
) - 1;
877 return val
!= ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1));
890 /* Given T, an expression, return the negation of T. Allow for T to be
891 null, in which case return null. */
903 type
= TREE_TYPE (t
);
906 switch (TREE_CODE (t
))
910 if (! TREE_UNSIGNED (type
)
911 && 0 != (tem
= fold (build1 (NEGATE_EXPR
, type
, t
)))
912 && ! TREE_OVERFLOW (tem
))
917 return convert (type
, TREE_OPERAND (t
, 0));
920 /* - (A - B) -> B - A */
921 if (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
922 return convert (type
,
923 fold (build (MINUS_EXPR
, TREE_TYPE (t
),
925 TREE_OPERAND (t
, 0))));
932 return convert (type
, fold (build1 (NEGATE_EXPR
, TREE_TYPE (t
), t
)));
935 /* Split a tree IN into a constant, literal and variable parts that could be
936 combined with CODE to make IN. "constant" means an expression with
937 TREE_CONSTANT but that isn't an actual constant. CODE must be a
938 commutative arithmetic operation. Store the constant part into *CONP,
939 the literal in *LITP and return the variable part. If a part isn't
940 present, set it to null. If the tree does not decompose in this way,
941 return the entire tree as the variable part and the other parts as null.
943 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
944 case, we negate an operand that was subtracted. Except if it is a
945 literal for which we use *MINUS_LITP instead.
947 If NEGATE_P is true, we are negating all of IN, again except a literal
948 for which we use *MINUS_LITP instead.
950 If IN is itself a literal or constant, return it as appropriate.
952 Note that we do not guarantee that any of the three values will be the
953 same type as IN, but they will have the same signedness and mode. */
956 split_tree (in
, code
, conp
, litp
, minus_litp
, negate_p
)
959 tree
*conp
, *litp
, *minus_litp
;
968 /* Strip any conversions that don't change the machine mode or signedness. */
969 STRIP_SIGN_NOPS (in
);
971 if (TREE_CODE (in
) == INTEGER_CST
|| TREE_CODE (in
) == REAL_CST
)
973 else if (TREE_CODE (in
) == code
974 || (! FLOAT_TYPE_P (TREE_TYPE (in
))
975 /* We can associate addition and subtraction together (even
976 though the C standard doesn't say so) for integers because
977 the value is not affected. For reals, the value might be
978 affected, so we can't. */
979 && ((code
== PLUS_EXPR
&& TREE_CODE (in
) == MINUS_EXPR
)
980 || (code
== MINUS_EXPR
&& TREE_CODE (in
) == PLUS_EXPR
))))
982 tree op0
= TREE_OPERAND (in
, 0);
983 tree op1
= TREE_OPERAND (in
, 1);
984 int neg1_p
= TREE_CODE (in
) == MINUS_EXPR
;
985 int neg_litp_p
= 0, neg_conp_p
= 0, neg_var_p
= 0;
987 /* First see if either of the operands is a literal, then a constant. */
988 if (TREE_CODE (op0
) == INTEGER_CST
|| TREE_CODE (op0
) == REAL_CST
)
989 *litp
= op0
, op0
= 0;
990 else if (TREE_CODE (op1
) == INTEGER_CST
|| TREE_CODE (op1
) == REAL_CST
)
991 *litp
= op1
, neg_litp_p
= neg1_p
, op1
= 0;
993 if (op0
!= 0 && TREE_CONSTANT (op0
))
994 *conp
= op0
, op0
= 0;
995 else if (op1
!= 0 && TREE_CONSTANT (op1
))
996 *conp
= op1
, neg_conp_p
= neg1_p
, op1
= 0;
998 /* If we haven't dealt with either operand, this is not a case we can
999 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1000 if (op0
!= 0 && op1
!= 0)
1005 var
= op1
, neg_var_p
= neg1_p
;
1007 /* Now do any needed negations. */
1009 *minus_litp
= *litp
, *litp
= 0;
1011 *conp
= negate_expr (*conp
);
1013 var
= negate_expr (var
);
1015 else if (TREE_CONSTANT (in
))
1023 *minus_litp
= *litp
, *litp
= 0;
1024 else if (*minus_litp
)
1025 *litp
= *minus_litp
, *minus_litp
= 0;
1026 *conp
= negate_expr (*conp
);
1027 var
= negate_expr (var
);
1033 /* Re-associate trees split by the above function. T1 and T2 are either
1034 expressions to associate or null. Return the new expression, if any. If
1035 we build an operation, do it in TYPE and with CODE. */
1038 associate_trees (t1
, t2
, code
, type
)
1040 enum tree_code code
;
1048 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1049 try to fold this since we will have infinite recursion. But do
1050 deal with any NEGATE_EXPRs. */
1051 if (TREE_CODE (t1
) == code
|| TREE_CODE (t2
) == code
1052 || TREE_CODE (t1
) == MINUS_EXPR
|| TREE_CODE (t2
) == MINUS_EXPR
)
1054 if (code
== PLUS_EXPR
)
1056 if (TREE_CODE (t1
) == NEGATE_EXPR
)
1057 return build (MINUS_EXPR
, type
, convert (type
, t2
),
1058 convert (type
, TREE_OPERAND (t1
, 0)));
1059 else if (TREE_CODE (t2
) == NEGATE_EXPR
)
1060 return build (MINUS_EXPR
, type
, convert (type
, t1
),
1061 convert (type
, TREE_OPERAND (t2
, 0)));
1063 return build (code
, type
, convert (type
, t1
), convert (type
, t2
));
1066 return fold (build (code
, type
, convert (type
, t1
), convert (type
, t2
)));
1069 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1070 to produce a new constant.
1072 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1075 int_const_binop (code
, arg1
, arg2
, notrunc
)
1076 enum tree_code code
;
1080 unsigned HOST_WIDE_INT int1l
, int2l
;
1081 HOST_WIDE_INT int1h
, int2h
;
1082 unsigned HOST_WIDE_INT low
;
1084 unsigned HOST_WIDE_INT garbagel
;
1085 HOST_WIDE_INT garbageh
;
1087 tree type
= TREE_TYPE (arg1
);
1088 int uns
= TREE_UNSIGNED (type
);
1090 = (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
));
1092 int no_overflow
= 0;
1094 int1l
= TREE_INT_CST_LOW (arg1
);
1095 int1h
= TREE_INT_CST_HIGH (arg1
);
1096 int2l
= TREE_INT_CST_LOW (arg2
);
1097 int2h
= TREE_INT_CST_HIGH (arg2
);
1102 low
= int1l
| int2l
, hi
= int1h
| int2h
;
1106 low
= int1l
^ int2l
, hi
= int1h
^ int2h
;
1110 low
= int1l
& int2l
, hi
= int1h
& int2h
;
1113 case BIT_ANDTC_EXPR
:
1114 low
= int1l
& ~int2l
, hi
= int1h
& ~int2h
;
1120 /* It's unclear from the C standard whether shifts can overflow.
1121 The following code ignores overflow; perhaps a C standard
1122 interpretation ruling is needed. */
1123 lshift_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1131 lrotate_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1136 overflow
= add_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1140 neg_double (int2l
, int2h
, &low
, &hi
);
1141 add_double (int1l
, int1h
, low
, hi
, &low
, &hi
);
1142 overflow
= OVERFLOW_SUM_SIGN (hi
, int2h
, int1h
);
1146 overflow
= mul_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1149 case TRUNC_DIV_EXPR
:
1150 case FLOOR_DIV_EXPR
: case CEIL_DIV_EXPR
:
1151 case EXACT_DIV_EXPR
:
1152 /* This is a shortcut for a common special case. */
1153 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1154 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1155 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1156 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1158 if (code
== CEIL_DIV_EXPR
)
1161 low
= int1l
/ int2l
, hi
= 0;
1165 /* ... fall through ... */
1167 case ROUND_DIV_EXPR
:
1168 if (int2h
== 0 && int2l
== 1)
1170 low
= int1l
, hi
= int1h
;
1173 if (int1l
== int2l
&& int1h
== int2h
1174 && ! (int1l
== 0 && int1h
== 0))
1179 overflow
= div_and_round_double (code
, uns
, int1l
, int1h
, int2l
, int2h
,
1180 &low
, &hi
, &garbagel
, &garbageh
);
1183 case TRUNC_MOD_EXPR
:
1184 case FLOOR_MOD_EXPR
: case CEIL_MOD_EXPR
:
1185 /* This is a shortcut for a common special case. */
1186 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1187 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1188 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1189 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1191 if (code
== CEIL_MOD_EXPR
)
1193 low
= int1l
% int2l
, hi
= 0;
1197 /* ... fall through ... */
1199 case ROUND_MOD_EXPR
:
1200 overflow
= div_and_round_double (code
, uns
,
1201 int1l
, int1h
, int2l
, int2h
,
1202 &garbagel
, &garbageh
, &low
, &hi
);
1208 low
= (((unsigned HOST_WIDE_INT
) int1h
1209 < (unsigned HOST_WIDE_INT
) int2h
)
1210 || (((unsigned HOST_WIDE_INT
) int1h
1211 == (unsigned HOST_WIDE_INT
) int2h
)
1214 low
= (int1h
< int2h
1215 || (int1h
== int2h
&& int1l
< int2l
));
1217 if (low
== (code
== MIN_EXPR
))
1218 low
= int1l
, hi
= int1h
;
1220 low
= int2l
, hi
= int2h
;
1227 /* If this is for a sizetype, can be represented as one (signed)
1228 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1231 && ((hi
== 0 && (HOST_WIDE_INT
) low
>= 0)
1232 || (hi
== -1 && (HOST_WIDE_INT
) low
< 0))
1233 && overflow
== 0 && ! TREE_OVERFLOW (arg1
) && ! TREE_OVERFLOW (arg2
))
1234 return size_int_type_wide (low
, type
);
1237 t
= build_int_2 (low
, hi
);
1238 TREE_TYPE (t
) = TREE_TYPE (arg1
);
1243 ? (!uns
|| is_sizetype
) && overflow
1244 : (force_fit_type (t
, (!uns
|| is_sizetype
) && overflow
)
1246 | TREE_OVERFLOW (arg1
)
1247 | TREE_OVERFLOW (arg2
));
1249 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1250 So check if force_fit_type truncated the value. */
1252 && ! TREE_OVERFLOW (t
)
1253 && (TREE_INT_CST_HIGH (t
) != hi
1254 || TREE_INT_CST_LOW (t
) != low
))
1255 TREE_OVERFLOW (t
) = 1;
1257 TREE_CONSTANT_OVERFLOW (t
) = (TREE_OVERFLOW (t
)
1258 | TREE_CONSTANT_OVERFLOW (arg1
)
1259 | TREE_CONSTANT_OVERFLOW (arg2
));
1263 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1264 constant. We assume ARG1 and ARG2 have the same data type, or at least
1265 are the same kind of constant and the same machine mode.
1267 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1270 const_binop (code
, arg1
, arg2
, notrunc
)
1271 enum tree_code code
;
1278 if (TREE_CODE (arg1
) == INTEGER_CST
)
1279 return int_const_binop (code
, arg1
, arg2
, notrunc
);
1281 if (TREE_CODE (arg1
) == REAL_CST
)
1285 REAL_VALUE_TYPE value
;
1288 d1
= TREE_REAL_CST (arg1
);
1289 d2
= TREE_REAL_CST (arg2
);
1291 /* If either operand is a NaN, just return it. Otherwise, set up
1292 for floating-point trap; we return an overflow. */
1293 if (REAL_VALUE_ISNAN (d1
))
1295 else if (REAL_VALUE_ISNAN (d2
))
1298 REAL_ARITHMETIC (value
, code
, d1
, d2
);
1300 t
= build_real (TREE_TYPE (arg1
),
1301 real_value_truncate (TYPE_MODE (TREE_TYPE (arg1
)),
1305 = (force_fit_type (t
, 0)
1306 | TREE_OVERFLOW (arg1
) | TREE_OVERFLOW (arg2
));
1307 TREE_CONSTANT_OVERFLOW (t
)
1309 | TREE_CONSTANT_OVERFLOW (arg1
)
1310 | TREE_CONSTANT_OVERFLOW (arg2
);
1313 if (TREE_CODE (arg1
) == COMPLEX_CST
)
1315 tree type
= TREE_TYPE (arg1
);
1316 tree r1
= TREE_REALPART (arg1
);
1317 tree i1
= TREE_IMAGPART (arg1
);
1318 tree r2
= TREE_REALPART (arg2
);
1319 tree i2
= TREE_IMAGPART (arg2
);
1325 t
= build_complex (type
,
1326 const_binop (PLUS_EXPR
, r1
, r2
, notrunc
),
1327 const_binop (PLUS_EXPR
, i1
, i2
, notrunc
));
1331 t
= build_complex (type
,
1332 const_binop (MINUS_EXPR
, r1
, r2
, notrunc
),
1333 const_binop (MINUS_EXPR
, i1
, i2
, notrunc
));
1337 t
= build_complex (type
,
1338 const_binop (MINUS_EXPR
,
1339 const_binop (MULT_EXPR
,
1341 const_binop (MULT_EXPR
,
1344 const_binop (PLUS_EXPR
,
1345 const_binop (MULT_EXPR
,
1347 const_binop (MULT_EXPR
,
1355 = const_binop (PLUS_EXPR
,
1356 const_binop (MULT_EXPR
, r2
, r2
, notrunc
),
1357 const_binop (MULT_EXPR
, i2
, i2
, notrunc
),
1360 t
= build_complex (type
,
1362 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1363 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1364 const_binop (PLUS_EXPR
,
1365 const_binop (MULT_EXPR
, r1
, r2
,
1367 const_binop (MULT_EXPR
, i1
, i2
,
1370 magsquared
, notrunc
),
1372 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1373 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1374 const_binop (MINUS_EXPR
,
1375 const_binop (MULT_EXPR
, i1
, r2
,
1377 const_binop (MULT_EXPR
, r1
, i2
,
1380 magsquared
, notrunc
));
1392 /* These are the hash table functions for the hash table of INTEGER_CST
1393 nodes of a sizetype. */
1395 /* Return the hash code code X, an INTEGER_CST. */
1403 return (TREE_INT_CST_HIGH (t
) ^ TREE_INT_CST_LOW (t
)
1404 ^ htab_hash_pointer (TREE_TYPE (t
))
1405 ^ (TREE_OVERFLOW (t
) << 20));
1408 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1409 is the same as that given by *Y, which is the same. */
1419 return (TREE_INT_CST_HIGH (xt
) == TREE_INT_CST_HIGH (yt
)
1420 && TREE_INT_CST_LOW (xt
) == TREE_INT_CST_LOW (yt
)
1421 && TREE_TYPE (xt
) == TREE_TYPE (yt
)
1422 && TREE_OVERFLOW (xt
) == TREE_OVERFLOW (yt
));
1425 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1426 bits are given by NUMBER and of the sizetype represented by KIND. */
1429 size_int_wide (number
, kind
)
1430 HOST_WIDE_INT number
;
1431 enum size_type_kind kind
;
1433 return size_int_type_wide (number
, sizetype_tab
[(int) kind
]);
1436 /* Likewise, but the desired type is specified explicitly. */
1438 static GTY (()) tree new_const
;
1439 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node
)))
1443 size_int_type_wide (number
, type
)
1444 HOST_WIDE_INT number
;
1451 size_htab
= htab_create_ggc (1024, size_htab_hash
, size_htab_eq
, NULL
);
1452 new_const
= make_node (INTEGER_CST
);
1455 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1456 hash table, we return the value from the hash table. Otherwise, we
1457 place that in the hash table and make a new node for the next time. */
1458 TREE_INT_CST_LOW (new_const
) = number
;
1459 TREE_INT_CST_HIGH (new_const
) = number
< 0 ? -1 : 0;
1460 TREE_TYPE (new_const
) = type
;
1461 TREE_OVERFLOW (new_const
) = TREE_CONSTANT_OVERFLOW (new_const
)
1462 = force_fit_type (new_const
, 0);
1464 slot
= htab_find_slot (size_htab
, new_const
, INSERT
);
1469 *slot
= (PTR
) new_const
;
1470 new_const
= make_node (INTEGER_CST
);
1474 return (tree
) *slot
;
1477 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1478 is a tree code. The type of the result is taken from the operands.
1479 Both must be the same type integer type and it must be a size type.
1480 If the operands are constant, so is the result. */
1483 size_binop (code
, arg0
, arg1
)
1484 enum tree_code code
;
1487 tree type
= TREE_TYPE (arg0
);
1489 if (TREE_CODE (type
) != INTEGER_TYPE
|| ! TYPE_IS_SIZETYPE (type
)
1490 || type
!= TREE_TYPE (arg1
))
1493 /* Handle the special case of two integer constants faster. */
1494 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
1496 /* And some specific cases even faster than that. */
1497 if (code
== PLUS_EXPR
&& integer_zerop (arg0
))
1499 else if ((code
== MINUS_EXPR
|| code
== PLUS_EXPR
)
1500 && integer_zerop (arg1
))
1502 else if (code
== MULT_EXPR
&& integer_onep (arg0
))
1505 /* Handle general case of two integer constants. */
1506 return int_const_binop (code
, arg0
, arg1
, 0);
1509 if (arg0
== error_mark_node
|| arg1
== error_mark_node
)
1510 return error_mark_node
;
1512 return fold (build (code
, type
, arg0
, arg1
));
1515 /* Given two values, either both of sizetype or both of bitsizetype,
1516 compute the difference between the two values. Return the value
1517 in signed type corresponding to the type of the operands. */
1520 size_diffop (arg0
, arg1
)
1523 tree type
= TREE_TYPE (arg0
);
1526 if (TREE_CODE (type
) != INTEGER_TYPE
|| ! TYPE_IS_SIZETYPE (type
)
1527 || type
!= TREE_TYPE (arg1
))
1530 /* If the type is already signed, just do the simple thing. */
1531 if (! TREE_UNSIGNED (type
))
1532 return size_binop (MINUS_EXPR
, arg0
, arg1
);
1534 ctype
= (type
== bitsizetype
|| type
== ubitsizetype
1535 ? sbitsizetype
: ssizetype
);
1537 /* If either operand is not a constant, do the conversions to the signed
1538 type and subtract. The hardware will do the right thing with any
1539 overflow in the subtraction. */
1540 if (TREE_CODE (arg0
) != INTEGER_CST
|| TREE_CODE (arg1
) != INTEGER_CST
)
1541 return size_binop (MINUS_EXPR
, convert (ctype
, arg0
),
1542 convert (ctype
, arg1
));
1544 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1545 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1546 overflow) and negate (which can't either). Special-case a result
1547 of zero while we're here. */
1548 if (tree_int_cst_equal (arg0
, arg1
))
1549 return convert (ctype
, integer_zero_node
);
1550 else if (tree_int_cst_lt (arg1
, arg0
))
1551 return convert (ctype
, size_binop (MINUS_EXPR
, arg0
, arg1
));
1553 return size_binop (MINUS_EXPR
, convert (ctype
, integer_zero_node
),
1554 convert (ctype
, size_binop (MINUS_EXPR
, arg1
, arg0
)));
1558 /* Given T, a tree representing type conversion of ARG1, a constant,
1559 return a constant tree representing the result of conversion. */
1562 fold_convert (t
, arg1
)
1566 tree type
= TREE_TYPE (t
);
1569 if (POINTER_TYPE_P (type
) || INTEGRAL_TYPE_P (type
))
1571 if (TREE_CODE (arg1
) == INTEGER_CST
)
1573 /* If we would build a constant wider than GCC supports,
1574 leave the conversion unfolded. */
1575 if (TYPE_PRECISION (type
) > 2 * HOST_BITS_PER_WIDE_INT
)
1578 /* If we are trying to make a sizetype for a small integer, use
1579 size_int to pick up cached types to reduce duplicate nodes. */
1580 if (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
)
1581 && !TREE_CONSTANT_OVERFLOW (arg1
)
1582 && compare_tree_int (arg1
, 10000) < 0)
1583 return size_int_type_wide (TREE_INT_CST_LOW (arg1
), type
);
1585 /* Given an integer constant, make new constant with new type,
1586 appropriately sign-extended or truncated. */
1587 t
= build_int_2 (TREE_INT_CST_LOW (arg1
),
1588 TREE_INT_CST_HIGH (arg1
));
1589 TREE_TYPE (t
) = type
;
1590 /* Indicate an overflow if (1) ARG1 already overflowed,
1591 or (2) force_fit_type indicates an overflow.
1592 Tell force_fit_type that an overflow has already occurred
1593 if ARG1 is a too-large unsigned value and T is signed.
1594 But don't indicate an overflow if converting a pointer. */
1596 = ((force_fit_type (t
,
1597 (TREE_INT_CST_HIGH (arg1
) < 0
1598 && (TREE_UNSIGNED (type
)
1599 < TREE_UNSIGNED (TREE_TYPE (arg1
)))))
1600 && ! POINTER_TYPE_P (TREE_TYPE (arg1
)))
1601 || TREE_OVERFLOW (arg1
));
1602 TREE_CONSTANT_OVERFLOW (t
)
1603 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1605 else if (TREE_CODE (arg1
) == REAL_CST
)
1607 /* Don't initialize these, use assignments.
1608 Initialized local aggregates don't work on old compilers. */
1612 tree type1
= TREE_TYPE (arg1
);
1615 x
= TREE_REAL_CST (arg1
);
1616 l
= real_value_from_int_cst (type1
, TYPE_MIN_VALUE (type
));
1618 no_upper_bound
= (TYPE_MAX_VALUE (type
) == NULL
);
1619 if (!no_upper_bound
)
1620 u
= real_value_from_int_cst (type1
, TYPE_MAX_VALUE (type
));
1622 /* See if X will be in range after truncation towards 0.
1623 To compensate for truncation, move the bounds away from 0,
1624 but reject if X exactly equals the adjusted bounds. */
1625 REAL_ARITHMETIC (l
, MINUS_EXPR
, l
, dconst1
);
1626 if (!no_upper_bound
)
1627 REAL_ARITHMETIC (u
, PLUS_EXPR
, u
, dconst1
);
1628 /* If X is a NaN, use zero instead and show we have an overflow.
1629 Otherwise, range check. */
1630 if (REAL_VALUE_ISNAN (x
))
1631 overflow
= 1, x
= dconst0
;
1632 else if (! (REAL_VALUES_LESS (l
, x
)
1634 && REAL_VALUES_LESS (x
, u
)))
1638 HOST_WIDE_INT low
, high
;
1639 REAL_VALUE_TO_INT (&low
, &high
, x
);
1640 t
= build_int_2 (low
, high
);
1642 TREE_TYPE (t
) = type
;
1644 = TREE_OVERFLOW (arg1
) | force_fit_type (t
, overflow
);
1645 TREE_CONSTANT_OVERFLOW (t
)
1646 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1648 TREE_TYPE (t
) = type
;
1650 else if (TREE_CODE (type
) == REAL_TYPE
)
1652 if (TREE_CODE (arg1
) == INTEGER_CST
)
1653 return build_real_from_int_cst (type
, arg1
);
1654 if (TREE_CODE (arg1
) == REAL_CST
)
1656 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
1658 /* We make a copy of ARG1 so that we don't modify an
1659 existing constant tree. */
1660 t
= copy_node (arg1
);
1661 TREE_TYPE (t
) = type
;
1665 t
= build_real (type
,
1666 real_value_truncate (TYPE_MODE (type
),
1667 TREE_REAL_CST (arg1
)));
1670 = TREE_OVERFLOW (arg1
) | force_fit_type (t
, 0);
1671 TREE_CONSTANT_OVERFLOW (t
)
1672 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1676 TREE_CONSTANT (t
) = 1;
1680 /* Return an expr equal to X but certainly not valid as an lvalue. */
1688 /* These things are certainly not lvalues. */
1689 if (TREE_CODE (x
) == NON_LVALUE_EXPR
1690 || TREE_CODE (x
) == INTEGER_CST
1691 || TREE_CODE (x
) == REAL_CST
1692 || TREE_CODE (x
) == STRING_CST
1693 || TREE_CODE (x
) == ADDR_EXPR
)
1696 result
= build1 (NON_LVALUE_EXPR
, TREE_TYPE (x
), x
);
1697 TREE_CONSTANT (result
) = TREE_CONSTANT (x
);
1701 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1702 Zero means allow extended lvalues. */
1704 int pedantic_lvalues
;
1706 /* When pedantic, return an expr equal to X but certainly not valid as a
1707 pedantic lvalue. Otherwise, return X. */
1710 pedantic_non_lvalue (x
)
1713 if (pedantic_lvalues
)
1714 return non_lvalue (x
);
1719 /* Given a tree comparison code, return the code that is the logical inverse
1720 of the given code. It is not safe to do this for floating-point
1721 comparisons, except for NE_EXPR and EQ_EXPR. */
1723 static enum tree_code
1724 invert_tree_comparison (code
)
1725 enum tree_code code
;
1746 /* Similar, but return the comparison that results if the operands are
1747 swapped. This is safe for floating-point. */
1749 static enum tree_code
1750 swap_tree_comparison (code
)
1751 enum tree_code code
;
1772 /* Convert a comparison tree code from an enum tree_code representation
1773 into a compcode bit-based encoding. This function is the inverse of
1774 compcode_to_comparison. */
1777 comparison_to_compcode (code
)
1778 enum tree_code code
;
1799 /* Convert a compcode bit-based encoding of a comparison operator back
1800 to GCC's enum tree_code representation. This function is the
1801 inverse of comparison_to_compcode. */
1803 static enum tree_code
1804 compcode_to_comparison (code
)
1826 /* Return nonzero if CODE is a tree code that represents a truth value. */
1829 truth_value_p (code
)
1830 enum tree_code code
;
1832 return (TREE_CODE_CLASS (code
) == '<'
1833 || code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
1834 || code
== TRUTH_OR_EXPR
|| code
== TRUTH_ORIF_EXPR
1835 || code
== TRUTH_XOR_EXPR
|| code
== TRUTH_NOT_EXPR
);
1838 /* Return nonzero if two operands are necessarily equal.
1839 If ONLY_CONST is nonzero, only return nonzero for constants.
1840 This function tests whether the operands are indistinguishable;
1841 it does not test whether they are equal using C's == operation.
1842 The distinction is important for IEEE floating point, because
1843 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
1844 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
1847 operand_equal_p (arg0
, arg1
, only_const
)
1851 /* If both types don't have the same signedness, then we can't consider
1852 them equal. We must check this before the STRIP_NOPS calls
1853 because they may change the signedness of the arguments. */
1854 if (TREE_UNSIGNED (TREE_TYPE (arg0
)) != TREE_UNSIGNED (TREE_TYPE (arg1
)))
1860 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
1861 /* This is needed for conversions and for COMPONENT_REF.
1862 Might as well play it safe and always test this. */
1863 || TREE_CODE (TREE_TYPE (arg0
)) == ERROR_MARK
1864 || TREE_CODE (TREE_TYPE (arg1
)) == ERROR_MARK
1865 || TYPE_MODE (TREE_TYPE (arg0
)) != TYPE_MODE (TREE_TYPE (arg1
)))
1868 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
1869 We don't care about side effects in that case because the SAVE_EXPR
1870 takes care of that for us. In all other cases, two expressions are
1871 equal if they have no side effects. If we have two identical
1872 expressions with side effects that should be treated the same due
1873 to the only side effects being identical SAVE_EXPR's, that will
1874 be detected in the recursive calls below. */
1875 if (arg0
== arg1
&& ! only_const
1876 && (TREE_CODE (arg0
) == SAVE_EXPR
1877 || (! TREE_SIDE_EFFECTS (arg0
) && ! TREE_SIDE_EFFECTS (arg1
))))
1880 /* Next handle constant cases, those for which we can return 1 even
1881 if ONLY_CONST is set. */
1882 if (TREE_CONSTANT (arg0
) && TREE_CONSTANT (arg1
))
1883 switch (TREE_CODE (arg0
))
1886 return (! TREE_CONSTANT_OVERFLOW (arg0
)
1887 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1888 && tree_int_cst_equal (arg0
, arg1
));
1891 return (! TREE_CONSTANT_OVERFLOW (arg0
)
1892 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1893 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0
),
1894 TREE_REAL_CST (arg1
)));
1900 if (TREE_CONSTANT_OVERFLOW (arg0
)
1901 || TREE_CONSTANT_OVERFLOW (arg1
))
1904 v1
= TREE_VECTOR_CST_ELTS (arg0
);
1905 v2
= TREE_VECTOR_CST_ELTS (arg1
);
1908 if (!operand_equal_p (v1
, v2
, only_const
))
1910 v1
= TREE_CHAIN (v1
);
1911 v2
= TREE_CHAIN (v2
);
1918 return (operand_equal_p (TREE_REALPART (arg0
), TREE_REALPART (arg1
),
1920 && operand_equal_p (TREE_IMAGPART (arg0
), TREE_IMAGPART (arg1
),
1924 return (TREE_STRING_LENGTH (arg0
) == TREE_STRING_LENGTH (arg1
)
1925 && ! memcmp (TREE_STRING_POINTER (arg0
),
1926 TREE_STRING_POINTER (arg1
),
1927 TREE_STRING_LENGTH (arg0
)));
1930 return operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0),
1939 switch (TREE_CODE_CLASS (TREE_CODE (arg0
)))
1942 /* Two conversions are equal only if signedness and modes match. */
1943 if ((TREE_CODE (arg0
) == NOP_EXPR
|| TREE_CODE (arg0
) == CONVERT_EXPR
)
1944 && (TREE_UNSIGNED (TREE_TYPE (arg0
))
1945 != TREE_UNSIGNED (TREE_TYPE (arg1
))))
1948 return operand_equal_p (TREE_OPERAND (arg0
, 0),
1949 TREE_OPERAND (arg1
, 0), 0);
1953 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0)
1954 && operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1),
1958 /* For commutative ops, allow the other order. */
1959 return ((TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MULT_EXPR
1960 || TREE_CODE (arg0
) == MIN_EXPR
|| TREE_CODE (arg0
) == MAX_EXPR
1961 || TREE_CODE (arg0
) == BIT_IOR_EXPR
1962 || TREE_CODE (arg0
) == BIT_XOR_EXPR
1963 || TREE_CODE (arg0
) == BIT_AND_EXPR
1964 || TREE_CODE (arg0
) == NE_EXPR
|| TREE_CODE (arg0
) == EQ_EXPR
)
1965 && operand_equal_p (TREE_OPERAND (arg0
, 0),
1966 TREE_OPERAND (arg1
, 1), 0)
1967 && operand_equal_p (TREE_OPERAND (arg0
, 1),
1968 TREE_OPERAND (arg1
, 0), 0));
1971 /* If either of the pointer (or reference) expressions we are dereferencing
1972 contain a side effect, these cannot be equal. */
1973 if (TREE_SIDE_EFFECTS (arg0
)
1974 || TREE_SIDE_EFFECTS (arg1
))
1977 switch (TREE_CODE (arg0
))
1980 return operand_equal_p (TREE_OPERAND (arg0
, 0),
1981 TREE_OPERAND (arg1
, 0), 0);
1985 case ARRAY_RANGE_REF
:
1986 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
1987 TREE_OPERAND (arg1
, 0), 0)
1988 && operand_equal_p (TREE_OPERAND (arg0
, 1),
1989 TREE_OPERAND (arg1
, 1), 0));
1992 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
1993 TREE_OPERAND (arg1
, 0), 0)
1994 && operand_equal_p (TREE_OPERAND (arg0
, 1),
1995 TREE_OPERAND (arg1
, 1), 0)
1996 && operand_equal_p (TREE_OPERAND (arg0
, 2),
1997 TREE_OPERAND (arg1
, 2), 0));
2003 switch (TREE_CODE (arg0
))
2006 case TRUTH_NOT_EXPR
:
2007 return operand_equal_p (TREE_OPERAND (arg0
, 0),
2008 TREE_OPERAND (arg1
, 0), 0);
2011 return rtx_equal_p (RTL_EXPR_RTL (arg0
), RTL_EXPR_RTL (arg1
));
2022 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2023 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2025 When in doubt, return 0. */
2028 operand_equal_for_comparison_p (arg0
, arg1
, other
)
2032 int unsignedp1
, unsignedpo
;
2033 tree primarg0
, primarg1
, primother
;
2034 unsigned int correct_width
;
2036 if (operand_equal_p (arg0
, arg1
, 0))
2039 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
2040 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
2043 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2044 and see if the inner values are the same. This removes any
2045 signedness comparison, which doesn't matter here. */
2046 primarg0
= arg0
, primarg1
= arg1
;
2047 STRIP_NOPS (primarg0
);
2048 STRIP_NOPS (primarg1
);
2049 if (operand_equal_p (primarg0
, primarg1
, 0))
2052 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2053 actual comparison operand, ARG0.
2055 First throw away any conversions to wider types
2056 already present in the operands. */
2058 primarg1
= get_narrower (arg1
, &unsignedp1
);
2059 primother
= get_narrower (other
, &unsignedpo
);
2061 correct_width
= TYPE_PRECISION (TREE_TYPE (arg1
));
2062 if (unsignedp1
== unsignedpo
2063 && TYPE_PRECISION (TREE_TYPE (primarg1
)) < correct_width
2064 && TYPE_PRECISION (TREE_TYPE (primother
)) < correct_width
)
2066 tree type
= TREE_TYPE (arg0
);
2068 /* Make sure shorter operand is extended the right way
2069 to match the longer operand. */
2070 primarg1
= convert ((*lang_hooks
.types
.signed_or_unsigned_type
)
2071 (unsignedp1
, TREE_TYPE (primarg1
)), primarg1
);
2073 if (operand_equal_p (arg0
, convert (type
, primarg1
), 0))
2080 /* See if ARG is an expression that is either a comparison or is performing
2081 arithmetic on comparisons. The comparisons must only be comparing
2082 two different values, which will be stored in *CVAL1 and *CVAL2; if
2083 they are nonzero it means that some operands have already been found.
2084 No variables may be used anywhere else in the expression except in the
2085 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2086 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2088 If this is true, return 1. Otherwise, return zero. */
2091 twoval_comparison_p (arg
, cval1
, cval2
, save_p
)
2093 tree
*cval1
, *cval2
;
2096 enum tree_code code
= TREE_CODE (arg
);
2097 char class = TREE_CODE_CLASS (code
);
2099 /* We can handle some of the 'e' cases here. */
2100 if (class == 'e' && code
== TRUTH_NOT_EXPR
)
2102 else if (class == 'e'
2103 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
2104 || code
== COMPOUND_EXPR
))
2107 else if (class == 'e' && code
== SAVE_EXPR
&& SAVE_EXPR_RTL (arg
) == 0
2108 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg
, 0)))
2110 /* If we've already found a CVAL1 or CVAL2, this expression is
2111 two complex to handle. */
2112 if (*cval1
|| *cval2
)
2122 return twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
);
2125 return (twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
)
2126 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2127 cval1
, cval2
, save_p
));
2133 if (code
== COND_EXPR
)
2134 return (twoval_comparison_p (TREE_OPERAND (arg
, 0),
2135 cval1
, cval2
, save_p
)
2136 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2137 cval1
, cval2
, save_p
)
2138 && twoval_comparison_p (TREE_OPERAND (arg
, 2),
2139 cval1
, cval2
, save_p
));
2143 /* First see if we can handle the first operand, then the second. For
2144 the second operand, we know *CVAL1 can't be zero. It must be that
2145 one side of the comparison is each of the values; test for the
2146 case where this isn't true by failing if the two operands
2149 if (operand_equal_p (TREE_OPERAND (arg
, 0),
2150 TREE_OPERAND (arg
, 1), 0))
2154 *cval1
= TREE_OPERAND (arg
, 0);
2155 else if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 0), 0))
2157 else if (*cval2
== 0)
2158 *cval2
= TREE_OPERAND (arg
, 0);
2159 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 0), 0))
2164 if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 1), 0))
2166 else if (*cval2
== 0)
2167 *cval2
= TREE_OPERAND (arg
, 1);
2168 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 1), 0))
2180 /* ARG is a tree that is known to contain just arithmetic operations and
2181 comparisons. Evaluate the operations in the tree substituting NEW0 for
2182 any occurrence of OLD0 as an operand of a comparison and likewise for
2186 eval_subst (arg
, old0
, new0
, old1
, new1
)
2188 tree old0
, new0
, old1
, new1
;
2190 tree type
= TREE_TYPE (arg
);
2191 enum tree_code code
= TREE_CODE (arg
);
2192 char class = TREE_CODE_CLASS (code
);
2194 /* We can handle some of the 'e' cases here. */
2195 if (class == 'e' && code
== TRUTH_NOT_EXPR
)
2197 else if (class == 'e'
2198 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
))
2204 return fold (build1 (code
, type
,
2205 eval_subst (TREE_OPERAND (arg
, 0),
2206 old0
, new0
, old1
, new1
)));
2209 return fold (build (code
, type
,
2210 eval_subst (TREE_OPERAND (arg
, 0),
2211 old0
, new0
, old1
, new1
),
2212 eval_subst (TREE_OPERAND (arg
, 1),
2213 old0
, new0
, old1
, new1
)));
2219 return eval_subst (TREE_OPERAND (arg
, 0), old0
, new0
, old1
, new1
);
2222 return eval_subst (TREE_OPERAND (arg
, 1), old0
, new0
, old1
, new1
);
2225 return fold (build (code
, type
,
2226 eval_subst (TREE_OPERAND (arg
, 0),
2227 old0
, new0
, old1
, new1
),
2228 eval_subst (TREE_OPERAND (arg
, 1),
2229 old0
, new0
, old1
, new1
),
2230 eval_subst (TREE_OPERAND (arg
, 2),
2231 old0
, new0
, old1
, new1
)));
2235 /* fall through - ??? */
2239 tree arg0
= TREE_OPERAND (arg
, 0);
2240 tree arg1
= TREE_OPERAND (arg
, 1);
2242 /* We need to check both for exact equality and tree equality. The
2243 former will be true if the operand has a side-effect. In that
2244 case, we know the operand occurred exactly once. */
2246 if (arg0
== old0
|| operand_equal_p (arg0
, old0
, 0))
2248 else if (arg0
== old1
|| operand_equal_p (arg0
, old1
, 0))
2251 if (arg1
== old0
|| operand_equal_p (arg1
, old0
, 0))
2253 else if (arg1
== old1
|| operand_equal_p (arg1
, old1
, 0))
2256 return fold (build (code
, type
, arg0
, arg1
));
2264 /* Return a tree for the case when the result of an expression is RESULT
2265 converted to TYPE and OMITTED was previously an operand of the expression
2266 but is now not needed (e.g., we folded OMITTED * 0).
2268 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2269 the conversion of RESULT to TYPE. */
2272 omit_one_operand (type
, result
, omitted
)
2273 tree type
, result
, omitted
;
2275 tree t
= convert (type
, result
);
2277 if (TREE_SIDE_EFFECTS (omitted
))
2278 return build (COMPOUND_EXPR
, type
, omitted
, t
);
2280 return non_lvalue (t
);
2283 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2286 pedantic_omit_one_operand (type
, result
, omitted
)
2287 tree type
, result
, omitted
;
2289 tree t
= convert (type
, result
);
2291 if (TREE_SIDE_EFFECTS (omitted
))
2292 return build (COMPOUND_EXPR
, type
, omitted
, t
);
2294 return pedantic_non_lvalue (t
);
2297 /* Return a simplified tree node for the truth-negation of ARG. This
2298 never alters ARG itself. We assume that ARG is an operation that
2299 returns a truth value (0 or 1). */
2302 invert_truthvalue (arg
)
2305 tree type
= TREE_TYPE (arg
);
2306 enum tree_code code
= TREE_CODE (arg
);
2308 if (code
== ERROR_MARK
)
2311 /* If this is a comparison, we can simply invert it, except for
2312 floating-point non-equality comparisons, in which case we just
2313 enclose a TRUTH_NOT_EXPR around what we have. */
2315 if (TREE_CODE_CLASS (code
) == '<')
2317 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg
, 0)))
2318 && !flag_unsafe_math_optimizations
2321 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2323 return build (invert_tree_comparison (code
), type
,
2324 TREE_OPERAND (arg
, 0), TREE_OPERAND (arg
, 1));
2330 return convert (type
, build_int_2 (integer_zerop (arg
), 0));
2332 case TRUTH_AND_EXPR
:
2333 return build (TRUTH_OR_EXPR
, type
,
2334 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2335 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2338 return build (TRUTH_AND_EXPR
, type
,
2339 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2340 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2342 case TRUTH_XOR_EXPR
:
2343 /* Here we can invert either operand. We invert the first operand
2344 unless the second operand is a TRUTH_NOT_EXPR in which case our
2345 result is the XOR of the first operand with the inside of the
2346 negation of the second operand. */
2348 if (TREE_CODE (TREE_OPERAND (arg
, 1)) == TRUTH_NOT_EXPR
)
2349 return build (TRUTH_XOR_EXPR
, type
, TREE_OPERAND (arg
, 0),
2350 TREE_OPERAND (TREE_OPERAND (arg
, 1), 0));
2352 return build (TRUTH_XOR_EXPR
, type
,
2353 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2354 TREE_OPERAND (arg
, 1));
2356 case TRUTH_ANDIF_EXPR
:
2357 return build (TRUTH_ORIF_EXPR
, type
,
2358 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2359 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2361 case TRUTH_ORIF_EXPR
:
2362 return build (TRUTH_ANDIF_EXPR
, type
,
2363 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2364 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2366 case TRUTH_NOT_EXPR
:
2367 return TREE_OPERAND (arg
, 0);
2370 return build (COND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2371 invert_truthvalue (TREE_OPERAND (arg
, 1)),
2372 invert_truthvalue (TREE_OPERAND (arg
, 2)));
2375 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2376 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2378 case WITH_RECORD_EXPR
:
2379 return build (WITH_RECORD_EXPR
, type
,
2380 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2381 TREE_OPERAND (arg
, 1));
2383 case NON_LVALUE_EXPR
:
2384 return invert_truthvalue (TREE_OPERAND (arg
, 0));
2389 return build1 (TREE_CODE (arg
), type
,
2390 invert_truthvalue (TREE_OPERAND (arg
, 0)));
2393 if (!integer_onep (TREE_OPERAND (arg
, 1)))
2395 return build (EQ_EXPR
, type
, arg
, convert (type
, integer_zero_node
));
2398 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2400 case CLEANUP_POINT_EXPR
:
2401 return build1 (CLEANUP_POINT_EXPR
, type
,
2402 invert_truthvalue (TREE_OPERAND (arg
, 0)));
2407 if (TREE_CODE (TREE_TYPE (arg
)) != BOOLEAN_TYPE
)
2409 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2412 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2413 operands are another bit-wise operation with a common input. If so,
2414 distribute the bit operations to save an operation and possibly two if
2415 constants are involved. For example, convert
2416 (A | B) & (A | C) into A | (B & C)
2417 Further simplification will occur if B and C are constants.
2419 If this optimization cannot be done, 0 will be returned. */
2422 distribute_bit_expr (code
, type
, arg0
, arg1
)
2423 enum tree_code code
;
2430 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
2431 || TREE_CODE (arg0
) == code
2432 || (TREE_CODE (arg0
) != BIT_AND_EXPR
2433 && TREE_CODE (arg0
) != BIT_IOR_EXPR
))
2436 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0))
2438 common
= TREE_OPERAND (arg0
, 0);
2439 left
= TREE_OPERAND (arg0
, 1);
2440 right
= TREE_OPERAND (arg1
, 1);
2442 else if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 1), 0))
2444 common
= TREE_OPERAND (arg0
, 0);
2445 left
= TREE_OPERAND (arg0
, 1);
2446 right
= TREE_OPERAND (arg1
, 0);
2448 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 0), 0))
2450 common
= TREE_OPERAND (arg0
, 1);
2451 left
= TREE_OPERAND (arg0
, 0);
2452 right
= TREE_OPERAND (arg1
, 1);
2454 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1), 0))
2456 common
= TREE_OPERAND (arg0
, 1);
2457 left
= TREE_OPERAND (arg0
, 0);
2458 right
= TREE_OPERAND (arg1
, 0);
2463 return fold (build (TREE_CODE (arg0
), type
, common
,
2464 fold (build (code
, type
, left
, right
))));
2467 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2468 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2471 make_bit_field_ref (inner
, type
, bitsize
, bitpos
, unsignedp
)
2474 int bitsize
, bitpos
;
2477 tree result
= build (BIT_FIELD_REF
, type
, inner
,
2478 size_int (bitsize
), bitsize_int (bitpos
));
2480 TREE_UNSIGNED (result
) = unsignedp
;
2485 /* Optimize a bit-field compare.
2487 There are two cases: First is a compare against a constant and the
2488 second is a comparison of two items where the fields are at the same
2489 bit position relative to the start of a chunk (byte, halfword, word)
2490 large enough to contain it. In these cases we can avoid the shift
2491 implicit in bitfield extractions.
2493 For constants, we emit a compare of the shifted constant with the
2494 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2495 compared. For two fields at the same position, we do the ANDs with the
2496 similar mask and compare the result of the ANDs.
2498 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2499 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2500 are the left and right operands of the comparison, respectively.
2502 If the optimization described above can be done, we return the resulting
2503 tree. Otherwise we return zero. */
2506 optimize_bit_field_compare (code
, compare_type
, lhs
, rhs
)
2507 enum tree_code code
;
2511 HOST_WIDE_INT lbitpos
, lbitsize
, rbitpos
, rbitsize
, nbitpos
, nbitsize
;
2512 tree type
= TREE_TYPE (lhs
);
2513 tree signed_type
, unsigned_type
;
2514 int const_p
= TREE_CODE (rhs
) == INTEGER_CST
;
2515 enum machine_mode lmode
, rmode
, nmode
;
2516 int lunsignedp
, runsignedp
;
2517 int lvolatilep
= 0, rvolatilep
= 0;
2518 tree linner
, rinner
= NULL_TREE
;
2522 /* Get all the information about the extractions being done. If the bit size
2523 if the same as the size of the underlying object, we aren't doing an
2524 extraction at all and so can do nothing. We also don't want to
2525 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2526 then will no longer be able to replace it. */
2527 linner
= get_inner_reference (lhs
, &lbitsize
, &lbitpos
, &offset
, &lmode
,
2528 &lunsignedp
, &lvolatilep
);
2529 if (linner
== lhs
|| lbitsize
== GET_MODE_BITSIZE (lmode
) || lbitsize
< 0
2530 || offset
!= 0 || TREE_CODE (linner
) == PLACEHOLDER_EXPR
)
2535 /* If this is not a constant, we can only do something if bit positions,
2536 sizes, and signedness are the same. */
2537 rinner
= get_inner_reference (rhs
, &rbitsize
, &rbitpos
, &offset
, &rmode
,
2538 &runsignedp
, &rvolatilep
);
2540 if (rinner
== rhs
|| lbitpos
!= rbitpos
|| lbitsize
!= rbitsize
2541 || lunsignedp
!= runsignedp
|| offset
!= 0
2542 || TREE_CODE (rinner
) == PLACEHOLDER_EXPR
)
2546 /* See if we can find a mode to refer to this field. We should be able to,
2547 but fail if we can't. */
2548 nmode
= get_best_mode (lbitsize
, lbitpos
,
2549 const_p
? TYPE_ALIGN (TREE_TYPE (linner
))
2550 : MIN (TYPE_ALIGN (TREE_TYPE (linner
)),
2551 TYPE_ALIGN (TREE_TYPE (rinner
))),
2552 word_mode
, lvolatilep
|| rvolatilep
);
2553 if (nmode
== VOIDmode
)
2556 /* Set signed and unsigned types of the precision of this mode for the
2558 signed_type
= (*lang_hooks
.types
.type_for_mode
) (nmode
, 0);
2559 unsigned_type
= (*lang_hooks
.types
.type_for_mode
) (nmode
, 1);
2561 /* Compute the bit position and size for the new reference and our offset
2562 within it. If the new reference is the same size as the original, we
2563 won't optimize anything, so return zero. */
2564 nbitsize
= GET_MODE_BITSIZE (nmode
);
2565 nbitpos
= lbitpos
& ~ (nbitsize
- 1);
2567 if (nbitsize
== lbitsize
)
2570 if (BYTES_BIG_ENDIAN
)
2571 lbitpos
= nbitsize
- lbitsize
- lbitpos
;
2573 /* Make the mask to be used against the extracted field. */
2574 mask
= build_int_2 (~0, ~0);
2575 TREE_TYPE (mask
) = unsigned_type
;
2576 force_fit_type (mask
, 0);
2577 mask
= convert (unsigned_type
, mask
);
2578 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (nbitsize
- lbitsize
), 0);
2579 mask
= const_binop (RSHIFT_EXPR
, mask
,
2580 size_int (nbitsize
- lbitsize
- lbitpos
), 0);
2583 /* If not comparing with constant, just rework the comparison
2585 return build (code
, compare_type
,
2586 build (BIT_AND_EXPR
, unsigned_type
,
2587 make_bit_field_ref (linner
, unsigned_type
,
2588 nbitsize
, nbitpos
, 1),
2590 build (BIT_AND_EXPR
, unsigned_type
,
2591 make_bit_field_ref (rinner
, unsigned_type
,
2592 nbitsize
, nbitpos
, 1),
2595 /* Otherwise, we are handling the constant case. See if the constant is too
2596 big for the field. Warn and return a tree of for 0 (false) if so. We do
2597 this not only for its own sake, but to avoid having to test for this
2598 error case below. If we didn't, we might generate wrong code.
2600 For unsigned fields, the constant shifted right by the field length should
2601 be all zero. For signed fields, the high-order bits should agree with
2606 if (! integer_zerop (const_binop (RSHIFT_EXPR
,
2607 convert (unsigned_type
, rhs
),
2608 size_int (lbitsize
), 0)))
2610 warning ("comparison is always %d due to width of bit-field",
2612 return convert (compare_type
,
2614 ? integer_one_node
: integer_zero_node
));
2619 tree tem
= const_binop (RSHIFT_EXPR
, convert (signed_type
, rhs
),
2620 size_int (lbitsize
- 1), 0);
2621 if (! integer_zerop (tem
) && ! integer_all_onesp (tem
))
2623 warning ("comparison is always %d due to width of bit-field",
2625 return convert (compare_type
,
2627 ? integer_one_node
: integer_zero_node
));
2631 /* Single-bit compares should always be against zero. */
2632 if (lbitsize
== 1 && ! integer_zerop (rhs
))
2634 code
= code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
;
2635 rhs
= convert (type
, integer_zero_node
);
2638 /* Make a new bitfield reference, shift the constant over the
2639 appropriate number of bits and mask it with the computed mask
2640 (in case this was a signed field). If we changed it, make a new one. */
2641 lhs
= make_bit_field_ref (linner
, unsigned_type
, nbitsize
, nbitpos
, 1);
2644 TREE_SIDE_EFFECTS (lhs
) = 1;
2645 TREE_THIS_VOLATILE (lhs
) = 1;
2648 rhs
= fold (const_binop (BIT_AND_EXPR
,
2649 const_binop (LSHIFT_EXPR
,
2650 convert (unsigned_type
, rhs
),
2651 size_int (lbitpos
), 0),
2654 return build (code
, compare_type
,
2655 build (BIT_AND_EXPR
, unsigned_type
, lhs
, mask
),
2659 /* Subroutine for fold_truthop: decode a field reference.
2661 If EXP is a comparison reference, we return the innermost reference.
2663 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2664 set to the starting bit number.
2666 If the innermost field can be completely contained in a mode-sized
2667 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2669 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2670 otherwise it is not changed.
2672 *PUNSIGNEDP is set to the signedness of the field.
2674 *PMASK is set to the mask used. This is either contained in a
2675 BIT_AND_EXPR or derived from the width of the field.
2677 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2679 Return 0 if this is not a component reference or is one that we can't
2680 do anything with. */
2683 decode_field_reference (exp
, pbitsize
, pbitpos
, pmode
, punsignedp
,
2684 pvolatilep
, pmask
, pand_mask
)
2686 HOST_WIDE_INT
*pbitsize
, *pbitpos
;
2687 enum machine_mode
*pmode
;
2688 int *punsignedp
, *pvolatilep
;
2693 tree mask
, inner
, offset
;
2695 unsigned int precision
;
2697 /* All the optimizations using this function assume integer fields.
2698 There are problems with FP fields since the type_for_size call
2699 below can fail for, e.g., XFmode. */
2700 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp
)))
2705 if (TREE_CODE (exp
) == BIT_AND_EXPR
)
2707 and_mask
= TREE_OPERAND (exp
, 1);
2708 exp
= TREE_OPERAND (exp
, 0);
2709 STRIP_NOPS (exp
); STRIP_NOPS (and_mask
);
2710 if (TREE_CODE (and_mask
) != INTEGER_CST
)
2714 inner
= get_inner_reference (exp
, pbitsize
, pbitpos
, &offset
, pmode
,
2715 punsignedp
, pvolatilep
);
2716 if ((inner
== exp
&& and_mask
== 0)
2717 || *pbitsize
< 0 || offset
!= 0
2718 || TREE_CODE (inner
) == PLACEHOLDER_EXPR
)
2721 /* Compute the mask to access the bitfield. */
2722 unsigned_type
= (*lang_hooks
.types
.type_for_size
) (*pbitsize
, 1);
2723 precision
= TYPE_PRECISION (unsigned_type
);
2725 mask
= build_int_2 (~0, ~0);
2726 TREE_TYPE (mask
) = unsigned_type
;
2727 force_fit_type (mask
, 0);
2728 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
2729 mask
= const_binop (RSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
2731 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
2733 mask
= fold (build (BIT_AND_EXPR
, unsigned_type
,
2734 convert (unsigned_type
, and_mask
), mask
));
2737 *pand_mask
= and_mask
;
2741 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
2745 all_ones_mask_p (mask
, size
)
2749 tree type
= TREE_TYPE (mask
);
2750 unsigned int precision
= TYPE_PRECISION (type
);
2753 tmask
= build_int_2 (~0, ~0);
2754 TREE_TYPE (tmask
) = (*lang_hooks
.types
.signed_type
) (type
);
2755 force_fit_type (tmask
, 0);
2757 tree_int_cst_equal (mask
,
2758 const_binop (RSHIFT_EXPR
,
2759 const_binop (LSHIFT_EXPR
, tmask
,
2760 size_int (precision
- size
),
2762 size_int (precision
- size
), 0));
2765 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
2766 represents the sign bit of EXP's type. If EXP represents a sign
2767 or zero extension, also test VAL against the unextended type.
2768 The return value is the (sub)expression whose sign bit is VAL,
2769 or NULL_TREE otherwise. */
2772 sign_bit_p (exp
, val
)
2776 unsigned HOST_WIDE_INT lo
;
2781 /* Tree EXP must have an integral type. */
2782 t
= TREE_TYPE (exp
);
2783 if (! INTEGRAL_TYPE_P (t
))
2786 /* Tree VAL must be an integer constant. */
2787 if (TREE_CODE (val
) != INTEGER_CST
2788 || TREE_CONSTANT_OVERFLOW (val
))
2791 width
= TYPE_PRECISION (t
);
2792 if (width
> HOST_BITS_PER_WIDE_INT
)
2794 hi
= (unsigned HOST_WIDE_INT
) 1 << (width
- HOST_BITS_PER_WIDE_INT
- 1);
2800 lo
= (unsigned HOST_WIDE_INT
) 1 << (width
- 1);
2803 if (TREE_INT_CST_HIGH (val
) == hi
&& TREE_INT_CST_LOW (val
) == lo
)
2806 /* Handle extension from a narrower type. */
2807 if (TREE_CODE (exp
) == NOP_EXPR
2808 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp
, 0))) < width
)
2809 return sign_bit_p (TREE_OPERAND (exp
, 0), val
);
2814 /* Subroutine for fold_truthop: determine if an operand is simple enough
2815 to be evaluated unconditionally. */
2818 simple_operand_p (exp
)
2821 /* Strip any conversions that don't change the machine mode. */
2822 while ((TREE_CODE (exp
) == NOP_EXPR
2823 || TREE_CODE (exp
) == CONVERT_EXPR
)
2824 && (TYPE_MODE (TREE_TYPE (exp
))
2825 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp
, 0)))))
2826 exp
= TREE_OPERAND (exp
, 0);
2828 return (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'c'
2830 && ! TREE_ADDRESSABLE (exp
)
2831 && ! TREE_THIS_VOLATILE (exp
)
2832 && ! DECL_NONLOCAL (exp
)
2833 /* Don't regard global variables as simple. They may be
2834 allocated in ways unknown to the compiler (shared memory,
2835 #pragma weak, etc). */
2836 && ! TREE_PUBLIC (exp
)
2837 && ! DECL_EXTERNAL (exp
)
2838 /* Loading a static variable is unduly expensive, but global
2839 registers aren't expensive. */
2840 && (! TREE_STATIC (exp
) || DECL_REGISTER (exp
))));
2843 /* The following functions are subroutines to fold_range_test and allow it to
2844 try to change a logical combination of comparisons into a range test.
2847 X == 2 || X == 3 || X == 4 || X == 5
2851 (unsigned) (X - 2) <= 3
2853 We describe each set of comparisons as being either inside or outside
2854 a range, using a variable named like IN_P, and then describe the
2855 range with a lower and upper bound. If one of the bounds is omitted,
2856 it represents either the highest or lowest value of the type.
2858 In the comments below, we represent a range by two numbers in brackets
2859 preceded by a "+" to designate being inside that range, or a "-" to
2860 designate being outside that range, so the condition can be inverted by
2861 flipping the prefix. An omitted bound is represented by a "-". For
2862 example, "- [-, 10]" means being outside the range starting at the lowest
2863 possible value and ending at 10, in other words, being greater than 10.
2864 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
2867 We set up things so that the missing bounds are handled in a consistent
2868 manner so neither a missing bound nor "true" and "false" need to be
2869 handled using a special case. */
2871 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
2872 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
2873 and UPPER1_P are nonzero if the respective argument is an upper bound
2874 and zero for a lower. TYPE, if nonzero, is the type of the result; it
2875 must be specified for a comparison. ARG1 will be converted to ARG0's
2876 type if both are specified. */
2879 range_binop (code
, type
, arg0
, upper0_p
, arg1
, upper1_p
)
2880 enum tree_code code
;
2883 int upper0_p
, upper1_p
;
2889 /* If neither arg represents infinity, do the normal operation.
2890 Else, if not a comparison, return infinity. Else handle the special
2891 comparison rules. Note that most of the cases below won't occur, but
2892 are handled for consistency. */
2894 if (arg0
!= 0 && arg1
!= 0)
2896 tem
= fold (build (code
, type
!= 0 ? type
: TREE_TYPE (arg0
),
2897 arg0
, convert (TREE_TYPE (arg0
), arg1
)));
2899 return TREE_CODE (tem
) == INTEGER_CST
? tem
: 0;
2902 if (TREE_CODE_CLASS (code
) != '<')
2905 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
2906 for neither. In real maths, we cannot assume open ended ranges are
2907 the same. But, this is computer arithmetic, where numbers are finite.
2908 We can therefore make the transformation of any unbounded range with
2909 the value Z, Z being greater than any representable number. This permits
2910 us to treat unbounded ranges as equal. */
2911 sgn0
= arg0
!= 0 ? 0 : (upper0_p
? 1 : -1);
2912 sgn1
= arg1
!= 0 ? 0 : (upper1_p
? 1 : -1);
2916 result
= sgn0
== sgn1
;
2919 result
= sgn0
!= sgn1
;
2922 result
= sgn0
< sgn1
;
2925 result
= sgn0
<= sgn1
;
2928 result
= sgn0
> sgn1
;
2931 result
= sgn0
>= sgn1
;
2937 return convert (type
, result
? integer_one_node
: integer_zero_node
);
2940 /* Given EXP, a logical expression, set the range it is testing into
2941 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
2942 actually being tested. *PLOW and *PHIGH will be made of the same type
2943 as the returned expression. If EXP is not a comparison, we will most
2944 likely not be returning a useful value and range. */
2947 make_range (exp
, pin_p
, plow
, phigh
)
2952 enum tree_code code
;
2953 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
, type
= NULL_TREE
;
2954 tree orig_type
= NULL_TREE
;
2956 tree low
, high
, n_low
, n_high
;
2958 /* Start with simply saying "EXP != 0" and then look at the code of EXP
2959 and see if we can refine the range. Some of the cases below may not
2960 happen, but it doesn't seem worth worrying about this. We "continue"
2961 the outer loop when we've changed something; otherwise we "break"
2962 the switch, which will "break" the while. */
2964 in_p
= 0, low
= high
= convert (TREE_TYPE (exp
), integer_zero_node
);
2968 code
= TREE_CODE (exp
);
2970 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code
)))
2972 arg0
= TREE_OPERAND (exp
, 0);
2973 if (TREE_CODE_CLASS (code
) == '<'
2974 || TREE_CODE_CLASS (code
) == '1'
2975 || TREE_CODE_CLASS (code
) == '2')
2976 type
= TREE_TYPE (arg0
);
2977 if (TREE_CODE_CLASS (code
) == '2'
2978 || TREE_CODE_CLASS (code
) == '<'
2979 || (TREE_CODE_CLASS (code
) == 'e'
2980 && TREE_CODE_LENGTH (code
) > 1))
2981 arg1
= TREE_OPERAND (exp
, 1);
2984 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
2985 lose a cast by accident. */
2986 if (type
!= NULL_TREE
&& orig_type
== NULL_TREE
)
2991 case TRUTH_NOT_EXPR
:
2992 in_p
= ! in_p
, exp
= arg0
;
2995 case EQ_EXPR
: case NE_EXPR
:
2996 case LT_EXPR
: case LE_EXPR
: case GE_EXPR
: case GT_EXPR
:
2997 /* We can only do something if the range is testing for zero
2998 and if the second operand is an integer constant. Note that
2999 saying something is "in" the range we make is done by
3000 complementing IN_P since it will set in the initial case of
3001 being not equal to zero; "out" is leaving it alone. */
3002 if (low
== 0 || high
== 0
3003 || ! integer_zerop (low
) || ! integer_zerop (high
)
3004 || TREE_CODE (arg1
) != INTEGER_CST
)
3009 case NE_EXPR
: /* - [c, c] */
3012 case EQ_EXPR
: /* + [c, c] */
3013 in_p
= ! in_p
, low
= high
= arg1
;
3015 case GT_EXPR
: /* - [-, c] */
3016 low
= 0, high
= arg1
;
3018 case GE_EXPR
: /* + [c, -] */
3019 in_p
= ! in_p
, low
= arg1
, high
= 0;
3021 case LT_EXPR
: /* - [c, -] */
3022 low
= arg1
, high
= 0;
3024 case LE_EXPR
: /* + [-, c] */
3025 in_p
= ! in_p
, low
= 0, high
= arg1
;
3033 /* If this is an unsigned comparison, we also know that EXP is
3034 greater than or equal to zero. We base the range tests we make
3035 on that fact, so we record it here so we can parse existing
3037 if (TREE_UNSIGNED (type
) && (low
== 0 || high
== 0))
3039 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
, in_p
, low
, high
,
3040 1, convert (type
, integer_zero_node
),
3044 in_p
= n_in_p
, low
= n_low
, high
= n_high
;
3046 /* If the high bound is missing, but we
3047 have a low bound, reverse the range so
3048 it goes from zero to the low bound minus 1. */
3049 if (high
== 0 && low
)
3052 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low
, 0,
3053 integer_one_node
, 0);
3054 low
= convert (type
, integer_zero_node
);
3060 /* (-x) IN [a,b] -> x in [-b, -a] */
3061 n_low
= range_binop (MINUS_EXPR
, type
,
3062 convert (type
, integer_zero_node
), 0, high
, 1);
3063 n_high
= range_binop (MINUS_EXPR
, type
,
3064 convert (type
, integer_zero_node
), 0, low
, 0);
3065 low
= n_low
, high
= n_high
;
3071 exp
= build (MINUS_EXPR
, type
, negate_expr (arg0
),
3072 convert (type
, integer_one_node
));
3075 case PLUS_EXPR
: case MINUS_EXPR
:
3076 if (TREE_CODE (arg1
) != INTEGER_CST
)
3079 /* If EXP is signed, any overflow in the computation is undefined,
3080 so we don't worry about it so long as our computations on
3081 the bounds don't overflow. For unsigned, overflow is defined
3082 and this is exactly the right thing. */
3083 n_low
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3084 type
, low
, 0, arg1
, 0);
3085 n_high
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3086 type
, high
, 1, arg1
, 0);
3087 if ((n_low
!= 0 && TREE_OVERFLOW (n_low
))
3088 || (n_high
!= 0 && TREE_OVERFLOW (n_high
)))
3091 /* Check for an unsigned range which has wrapped around the maximum
3092 value thus making n_high < n_low, and normalize it. */
3093 if (n_low
&& n_high
&& tree_int_cst_lt (n_high
, n_low
))
3095 low
= range_binop (PLUS_EXPR
, type
, n_high
, 0,
3096 integer_one_node
, 0);
3097 high
= range_binop (MINUS_EXPR
, type
, n_low
, 0,
3098 integer_one_node
, 0);
3100 /* If the range is of the form +/- [ x+1, x ], we won't
3101 be able to normalize it. But then, it represents the
3102 whole range or the empty set, so make it
3104 if (tree_int_cst_equal (n_low
, low
)
3105 && tree_int_cst_equal (n_high
, high
))
3111 low
= n_low
, high
= n_high
;
3116 case NOP_EXPR
: case NON_LVALUE_EXPR
: case CONVERT_EXPR
:
3117 if (TYPE_PRECISION (type
) > TYPE_PRECISION (orig_type
))
3120 if (! INTEGRAL_TYPE_P (type
)
3121 || (low
!= 0 && ! int_fits_type_p (low
, type
))
3122 || (high
!= 0 && ! int_fits_type_p (high
, type
)))
3125 n_low
= low
, n_high
= high
;
3128 n_low
= convert (type
, n_low
);
3131 n_high
= convert (type
, n_high
);
3133 /* If we're converting from an unsigned to a signed type,
3134 we will be doing the comparison as unsigned. The tests above
3135 have already verified that LOW and HIGH are both positive.
3137 So we have to make sure that the original unsigned value will
3138 be interpreted as positive. */
3139 if (TREE_UNSIGNED (type
) && ! TREE_UNSIGNED (TREE_TYPE (exp
)))
3141 tree equiv_type
= (*lang_hooks
.types
.type_for_mode
)
3142 (TYPE_MODE (type
), 1);
3145 /* A range without an upper bound is, naturally, unbounded.
3146 Since convert would have cropped a very large value, use
3147 the max value for the destination type. */
3149 = TYPE_MAX_VALUE (equiv_type
) ? TYPE_MAX_VALUE (equiv_type
)
3150 : TYPE_MAX_VALUE (type
);
3152 if (TYPE_PRECISION (type
) == TYPE_PRECISION (TREE_TYPE (exp
)))
3153 high_positive
= fold (build (RSHIFT_EXPR
, type
,
3154 convert (type
, high_positive
),
3155 convert (type
, integer_one_node
)));
3157 /* If the low bound is specified, "and" the range with the
3158 range for which the original unsigned value will be
3162 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3164 1, convert (type
, integer_zero_node
),
3168 in_p
= (n_in_p
== in_p
);
3172 /* Otherwise, "or" the range with the range of the input
3173 that will be interpreted as negative. */
3174 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3176 1, convert (type
, integer_zero_node
),
3180 in_p
= (in_p
!= n_in_p
);
3185 low
= n_low
, high
= n_high
;
3195 /* If EXP is a constant, we can evaluate whether this is true or false. */
3196 if (TREE_CODE (exp
) == INTEGER_CST
)
3198 in_p
= in_p
== (integer_onep (range_binop (GE_EXPR
, integer_type_node
,
3200 && integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3206 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
3210 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3211 type, TYPE, return an expression to test if EXP is in (or out of, depending
3212 on IN_P) the range. */
3215 build_range_check (type
, exp
, in_p
, low
, high
)
3221 tree etype
= TREE_TYPE (exp
);
3225 && (0 != (value
= build_range_check (type
, exp
, 1, low
, high
))))
3226 return invert_truthvalue (value
);
3228 if (low
== 0 && high
== 0)
3229 return convert (type
, integer_one_node
);
3232 return fold (build (LE_EXPR
, type
, exp
, high
));
3235 return fold (build (GE_EXPR
, type
, exp
, low
));
3237 if (operand_equal_p (low
, high
, 0))
3238 return fold (build (EQ_EXPR
, type
, exp
, low
));
3240 if (integer_zerop (low
))
3242 if (! TREE_UNSIGNED (etype
))
3244 etype
= (*lang_hooks
.types
.unsigned_type
) (etype
);
3245 high
= convert (etype
, high
);
3246 exp
= convert (etype
, exp
);
3248 return build_range_check (type
, exp
, 1, 0, high
);
3251 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3252 if (integer_onep (low
) && TREE_CODE (high
) == INTEGER_CST
)
3254 unsigned HOST_WIDE_INT lo
;
3258 prec
= TYPE_PRECISION (etype
);
3259 if (prec
<= HOST_BITS_PER_WIDE_INT
)
3262 lo
= ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1)) - 1;
3266 hi
= ((HOST_WIDE_INT
) 1 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)) - 1;
3267 lo
= (unsigned HOST_WIDE_INT
) -1;
3270 if (TREE_INT_CST_HIGH (high
) == hi
&& TREE_INT_CST_LOW (high
) == lo
)
3272 if (TREE_UNSIGNED (etype
))
3274 etype
= (*lang_hooks
.types
.signed_type
) (etype
);
3275 exp
= convert (etype
, exp
);
3277 return fold (build (GT_EXPR
, type
, exp
,
3278 convert (etype
, integer_zero_node
)));
3282 if (0 != (value
= const_binop (MINUS_EXPR
, high
, low
, 0))
3283 && ! TREE_OVERFLOW (value
))
3284 return build_range_check (type
,
3285 fold (build (MINUS_EXPR
, etype
, exp
, low
)),
3286 1, convert (etype
, integer_zero_node
), value
);
3291 /* Given two ranges, see if we can merge them into one. Return 1 if we
3292 can, 0 if we can't. Set the output range into the specified parameters. */
3295 merge_ranges (pin_p
, plow
, phigh
, in0_p
, low0
, high0
, in1_p
, low1
, high1
)
3299 tree low0
, high0
, low1
, high1
;
3307 int lowequal
= ((low0
== 0 && low1
== 0)
3308 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3309 low0
, 0, low1
, 0)));
3310 int highequal
= ((high0
== 0 && high1
== 0)
3311 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3312 high0
, 1, high1
, 1)));
3314 /* Make range 0 be the range that starts first, or ends last if they
3315 start at the same value. Swap them if it isn't. */
3316 if (integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3319 && integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3320 high1
, 1, high0
, 1))))
3322 temp
= in0_p
, in0_p
= in1_p
, in1_p
= temp
;
3323 tem
= low0
, low0
= low1
, low1
= tem
;
3324 tem
= high0
, high0
= high1
, high1
= tem
;
3327 /* Now flag two cases, whether the ranges are disjoint or whether the
3328 second range is totally subsumed in the first. Note that the tests
3329 below are simplified by the ones above. */
3330 no_overlap
= integer_onep (range_binop (LT_EXPR
, integer_type_node
,
3331 high0
, 1, low1
, 0));
3332 subset
= integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3333 high1
, 1, high0
, 1));
3335 /* We now have four cases, depending on whether we are including or
3336 excluding the two ranges. */
3339 /* If they don't overlap, the result is false. If the second range
3340 is a subset it is the result. Otherwise, the range is from the start
3341 of the second to the end of the first. */
3343 in_p
= 0, low
= high
= 0;
3345 in_p
= 1, low
= low1
, high
= high1
;
3347 in_p
= 1, low
= low1
, high
= high0
;
3350 else if (in0_p
&& ! in1_p
)
3352 /* If they don't overlap, the result is the first range. If they are
3353 equal, the result is false. If the second range is a subset of the
3354 first, and the ranges begin at the same place, we go from just after
3355 the end of the first range to the end of the second. If the second
3356 range is not a subset of the first, or if it is a subset and both
3357 ranges end at the same place, the range starts at the start of the
3358 first range and ends just before the second range.
3359 Otherwise, we can't describe this as a single range. */
3361 in_p
= 1, low
= low0
, high
= high0
;
3362 else if (lowequal
&& highequal
)
3363 in_p
= 0, low
= high
= 0;
3364 else if (subset
&& lowequal
)
3366 in_p
= 1, high
= high0
;
3367 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high1
, 0,
3368 integer_one_node
, 0);
3370 else if (! subset
|| highequal
)
3372 in_p
= 1, low
= low0
;
3373 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low1
, 0,
3374 integer_one_node
, 0);
3380 else if (! in0_p
&& in1_p
)
3382 /* If they don't overlap, the result is the second range. If the second
3383 is a subset of the first, the result is false. Otherwise,
3384 the range starts just after the first range and ends at the
3385 end of the second. */
3387 in_p
= 1, low
= low1
, high
= high1
;
3388 else if (subset
|| highequal
)
3389 in_p
= 0, low
= high
= 0;
3392 in_p
= 1, high
= high1
;
3393 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high0
, 1,
3394 integer_one_node
, 0);
3400 /* The case where we are excluding both ranges. Here the complex case
3401 is if they don't overlap. In that case, the only time we have a
3402 range is if they are adjacent. If the second is a subset of the
3403 first, the result is the first. Otherwise, the range to exclude
3404 starts at the beginning of the first range and ends at the end of the
3408 if (integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3409 range_binop (PLUS_EXPR
, NULL_TREE
,
3411 integer_one_node
, 1),
3413 in_p
= 0, low
= low0
, high
= high1
;
3418 in_p
= 0, low
= low0
, high
= high0
;
3420 in_p
= 0, low
= low0
, high
= high1
;
3423 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
3427 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
3428 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
3431 /* EXP is some logical combination of boolean tests. See if we can
3432 merge it into some range test. Return the new tree if so. */
3435 fold_range_test (exp
)
3438 int or_op
= (TREE_CODE (exp
) == TRUTH_ORIF_EXPR
3439 || TREE_CODE (exp
) == TRUTH_OR_EXPR
);
3440 int in0_p
, in1_p
, in_p
;
3441 tree low0
, low1
, low
, high0
, high1
, high
;
3442 tree lhs
= make_range (TREE_OPERAND (exp
, 0), &in0_p
, &low0
, &high0
);
3443 tree rhs
= make_range (TREE_OPERAND (exp
, 1), &in1_p
, &low1
, &high1
);
3446 /* If this is an OR operation, invert both sides; we will invert
3447 again at the end. */
3449 in0_p
= ! in0_p
, in1_p
= ! in1_p
;
3451 /* If both expressions are the same, if we can merge the ranges, and we
3452 can build the range test, return it or it inverted. If one of the
3453 ranges is always true or always false, consider it to be the same
3454 expression as the other. */
3455 if ((lhs
== 0 || rhs
== 0 || operand_equal_p (lhs
, rhs
, 0))
3456 && merge_ranges (&in_p
, &low
, &high
, in0_p
, low0
, high0
,
3458 && 0 != (tem
= (build_range_check (TREE_TYPE (exp
),
3460 : rhs
!= 0 ? rhs
: integer_zero_node
,
3462 return or_op
? invert_truthvalue (tem
) : tem
;
3464 /* On machines where the branch cost is expensive, if this is a
3465 short-circuited branch and the underlying object on both sides
3466 is the same, make a non-short-circuit operation. */
3467 else if (RANGE_TEST_NON_SHORT_CIRCUIT
3468 && lhs
!= 0 && rhs
!= 0
3469 && (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3470 || TREE_CODE (exp
) == TRUTH_ORIF_EXPR
)
3471 && operand_equal_p (lhs
, rhs
, 0))
3473 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3474 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3475 which cases we can't do this. */
3476 if (simple_operand_p (lhs
))
3477 return build (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3478 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
3479 TREE_TYPE (exp
), TREE_OPERAND (exp
, 0),
3480 TREE_OPERAND (exp
, 1));
3482 else if ((*lang_hooks
.decls
.global_bindings_p
) () == 0
3483 && ! CONTAINS_PLACEHOLDER_P (lhs
))
3485 tree common
= save_expr (lhs
);
3487 if (0 != (lhs
= build_range_check (TREE_TYPE (exp
), common
,
3488 or_op
? ! in0_p
: in0_p
,
3490 && (0 != (rhs
= build_range_check (TREE_TYPE (exp
), common
,
3491 or_op
? ! in1_p
: in1_p
,
3493 return build (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3494 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
3495 TREE_TYPE (exp
), lhs
, rhs
);
3502 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3503 bit value. Arrange things so the extra bits will be set to zero if and
3504 only if C is signed-extended to its full width. If MASK is nonzero,
3505 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3508 unextend (c
, p
, unsignedp
, mask
)
3514 tree type
= TREE_TYPE (c
);
3515 int modesize
= GET_MODE_BITSIZE (TYPE_MODE (type
));
3518 if (p
== modesize
|| unsignedp
)
3521 /* We work by getting just the sign bit into the low-order bit, then
3522 into the high-order bit, then sign-extend. We then XOR that value
3524 temp
= const_binop (RSHIFT_EXPR
, c
, size_int (p
- 1), 0);
3525 temp
= const_binop (BIT_AND_EXPR
, temp
, size_int (1), 0);
3527 /* We must use a signed type in order to get an arithmetic right shift.
3528 However, we must also avoid introducing accidental overflows, so that
3529 a subsequent call to integer_zerop will work. Hence we must
3530 do the type conversion here. At this point, the constant is either
3531 zero or one, and the conversion to a signed type can never overflow.
3532 We could get an overflow if this conversion is done anywhere else. */
3533 if (TREE_UNSIGNED (type
))
3534 temp
= convert ((*lang_hooks
.types
.signed_type
) (type
), temp
);
3536 temp
= const_binop (LSHIFT_EXPR
, temp
, size_int (modesize
- 1), 0);
3537 temp
= const_binop (RSHIFT_EXPR
, temp
, size_int (modesize
- p
- 1), 0);
3539 temp
= const_binop (BIT_AND_EXPR
, temp
, convert (TREE_TYPE (c
), mask
), 0);
3540 /* If necessary, convert the type back to match the type of C. */
3541 if (TREE_UNSIGNED (type
))
3542 temp
= convert (type
, temp
);
3544 return convert (type
, const_binop (BIT_XOR_EXPR
, c
, temp
, 0));
3547 /* Find ways of folding logical expressions of LHS and RHS:
3548 Try to merge two comparisons to the same innermost item.
3549 Look for range tests like "ch >= '0' && ch <= '9'".
3550 Look for combinations of simple terms on machines with expensive branches
3551 and evaluate the RHS unconditionally.
3553 For example, if we have p->a == 2 && p->b == 4 and we can make an
3554 object large enough to span both A and B, we can do this with a comparison
3555 against the object ANDed with the a mask.
3557 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3558 operations to do this with one comparison.
3560 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3561 function and the one above.
3563 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3564 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3566 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3569 We return the simplified tree or 0 if no optimization is possible. */
3572 fold_truthop (code
, truth_type
, lhs
, rhs
)
3573 enum tree_code code
;
3574 tree truth_type
, lhs
, rhs
;
3576 /* If this is the "or" of two comparisons, we can do something if
3577 the comparisons are NE_EXPR. If this is the "and", we can do something
3578 if the comparisons are EQ_EXPR. I.e.,
3579 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3581 WANTED_CODE is this operation code. For single bit fields, we can
3582 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3583 comparison for one-bit fields. */
3585 enum tree_code wanted_code
;
3586 enum tree_code lcode
, rcode
;
3587 tree ll_arg
, lr_arg
, rl_arg
, rr_arg
;
3588 tree ll_inner
, lr_inner
, rl_inner
, rr_inner
;
3589 HOST_WIDE_INT ll_bitsize
, ll_bitpos
, lr_bitsize
, lr_bitpos
;
3590 HOST_WIDE_INT rl_bitsize
, rl_bitpos
, rr_bitsize
, rr_bitpos
;
3591 HOST_WIDE_INT xll_bitpos
, xlr_bitpos
, xrl_bitpos
, xrr_bitpos
;
3592 HOST_WIDE_INT lnbitsize
, lnbitpos
, rnbitsize
, rnbitpos
;
3593 int ll_unsignedp
, lr_unsignedp
, rl_unsignedp
, rr_unsignedp
;
3594 enum machine_mode ll_mode
, lr_mode
, rl_mode
, rr_mode
;
3595 enum machine_mode lnmode
, rnmode
;
3596 tree ll_mask
, lr_mask
, rl_mask
, rr_mask
;
3597 tree ll_and_mask
, lr_and_mask
, rl_and_mask
, rr_and_mask
;
3598 tree l_const
, r_const
;
3599 tree lntype
, rntype
, result
;
3600 int first_bit
, end_bit
;
3603 /* Start by getting the comparison codes. Fail if anything is volatile.
3604 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3605 it were surrounded with a NE_EXPR. */
3607 if (TREE_SIDE_EFFECTS (lhs
) || TREE_SIDE_EFFECTS (rhs
))
3610 lcode
= TREE_CODE (lhs
);
3611 rcode
= TREE_CODE (rhs
);
3613 if (lcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (lhs
, 1)))
3614 lcode
= NE_EXPR
, lhs
= build (NE_EXPR
, truth_type
, lhs
, integer_zero_node
);
3616 if (rcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (rhs
, 1)))
3617 rcode
= NE_EXPR
, rhs
= build (NE_EXPR
, truth_type
, rhs
, integer_zero_node
);
3619 if (TREE_CODE_CLASS (lcode
) != '<' || TREE_CODE_CLASS (rcode
) != '<')
3622 code
= ((code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
)
3623 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
);
3625 ll_arg
= TREE_OPERAND (lhs
, 0);
3626 lr_arg
= TREE_OPERAND (lhs
, 1);
3627 rl_arg
= TREE_OPERAND (rhs
, 0);
3628 rr_arg
= TREE_OPERAND (rhs
, 1);
3630 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
3631 if (simple_operand_p (ll_arg
)
3632 && simple_operand_p (lr_arg
)
3633 && !FLOAT_TYPE_P (TREE_TYPE (ll_arg
)))
3637 if (operand_equal_p (ll_arg
, rl_arg
, 0)
3638 && operand_equal_p (lr_arg
, rr_arg
, 0))
3640 int lcompcode
, rcompcode
;
3642 lcompcode
= comparison_to_compcode (lcode
);
3643 rcompcode
= comparison_to_compcode (rcode
);
3644 compcode
= (code
== TRUTH_AND_EXPR
)
3645 ? lcompcode
& rcompcode
3646 : lcompcode
| rcompcode
;
3648 else if (operand_equal_p (ll_arg
, rr_arg
, 0)
3649 && operand_equal_p (lr_arg
, rl_arg
, 0))
3651 int lcompcode
, rcompcode
;
3653 rcode
= swap_tree_comparison (rcode
);
3654 lcompcode
= comparison_to_compcode (lcode
);
3655 rcompcode
= comparison_to_compcode (rcode
);
3656 compcode
= (code
== TRUTH_AND_EXPR
)
3657 ? lcompcode
& rcompcode
3658 : lcompcode
| rcompcode
;
3663 if (compcode
== COMPCODE_TRUE
)
3664 return convert (truth_type
, integer_one_node
);
3665 else if (compcode
== COMPCODE_FALSE
)
3666 return convert (truth_type
, integer_zero_node
);
3667 else if (compcode
!= -1)
3668 return build (compcode_to_comparison (compcode
),
3669 truth_type
, ll_arg
, lr_arg
);
3672 /* If the RHS can be evaluated unconditionally and its operands are
3673 simple, it wins to evaluate the RHS unconditionally on machines
3674 with expensive branches. In this case, this isn't a comparison
3675 that can be merged. Avoid doing this if the RHS is a floating-point
3676 comparison since those can trap. */
3678 if (BRANCH_COST
>= 2
3679 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg
))
3680 && simple_operand_p (rl_arg
)
3681 && simple_operand_p (rr_arg
))
3683 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
3684 if (code
== TRUTH_OR_EXPR
3685 && lcode
== NE_EXPR
&& integer_zerop (lr_arg
)
3686 && rcode
== NE_EXPR
&& integer_zerop (rr_arg
)
3687 && TREE_TYPE (ll_arg
) == TREE_TYPE (rl_arg
))
3688 return build (NE_EXPR
, truth_type
,
3689 build (BIT_IOR_EXPR
, TREE_TYPE (ll_arg
),
3693 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
3694 if (code
== TRUTH_AND_EXPR
3695 && lcode
== EQ_EXPR
&& integer_zerop (lr_arg
)
3696 && rcode
== EQ_EXPR
&& integer_zerop (rr_arg
)
3697 && TREE_TYPE (ll_arg
) == TREE_TYPE (rl_arg
))
3698 return build (EQ_EXPR
, truth_type
,
3699 build (BIT_IOR_EXPR
, TREE_TYPE (ll_arg
),
3703 return build (code
, truth_type
, lhs
, rhs
);
3706 /* See if the comparisons can be merged. Then get all the parameters for
3709 if ((lcode
!= EQ_EXPR
&& lcode
!= NE_EXPR
)
3710 || (rcode
!= EQ_EXPR
&& rcode
!= NE_EXPR
))
3714 ll_inner
= decode_field_reference (ll_arg
,
3715 &ll_bitsize
, &ll_bitpos
, &ll_mode
,
3716 &ll_unsignedp
, &volatilep
, &ll_mask
,
3718 lr_inner
= decode_field_reference (lr_arg
,
3719 &lr_bitsize
, &lr_bitpos
, &lr_mode
,
3720 &lr_unsignedp
, &volatilep
, &lr_mask
,
3722 rl_inner
= decode_field_reference (rl_arg
,
3723 &rl_bitsize
, &rl_bitpos
, &rl_mode
,
3724 &rl_unsignedp
, &volatilep
, &rl_mask
,
3726 rr_inner
= decode_field_reference (rr_arg
,
3727 &rr_bitsize
, &rr_bitpos
, &rr_mode
,
3728 &rr_unsignedp
, &volatilep
, &rr_mask
,
3731 /* It must be true that the inner operation on the lhs of each
3732 comparison must be the same if we are to be able to do anything.
3733 Then see if we have constants. If not, the same must be true for
3735 if (volatilep
|| ll_inner
== 0 || rl_inner
== 0
3736 || ! operand_equal_p (ll_inner
, rl_inner
, 0))
3739 if (TREE_CODE (lr_arg
) == INTEGER_CST
3740 && TREE_CODE (rr_arg
) == INTEGER_CST
)
3741 l_const
= lr_arg
, r_const
= rr_arg
;
3742 else if (lr_inner
== 0 || rr_inner
== 0
3743 || ! operand_equal_p (lr_inner
, rr_inner
, 0))
3746 l_const
= r_const
= 0;
3748 /* If either comparison code is not correct for our logical operation,
3749 fail. However, we can convert a one-bit comparison against zero into
3750 the opposite comparison against that bit being set in the field. */
3752 wanted_code
= (code
== TRUTH_AND_EXPR
? EQ_EXPR
: NE_EXPR
);
3753 if (lcode
!= wanted_code
)
3755 if (l_const
&& integer_zerop (l_const
) && integer_pow2p (ll_mask
))
3757 /* Make the left operand unsigned, since we are only interested
3758 in the value of one bit. Otherwise we are doing the wrong
3767 /* This is analogous to the code for l_const above. */
3768 if (rcode
!= wanted_code
)
3770 if (r_const
&& integer_zerop (r_const
) && integer_pow2p (rl_mask
))
3779 /* After this point all optimizations will generate bit-field
3780 references, which we might not want. */
3781 if (! (*lang_hooks
.can_use_bit_fields_p
) ())
3784 /* See if we can find a mode that contains both fields being compared on
3785 the left. If we can't, fail. Otherwise, update all constants and masks
3786 to be relative to a field of that size. */
3787 first_bit
= MIN (ll_bitpos
, rl_bitpos
);
3788 end_bit
= MAX (ll_bitpos
+ ll_bitsize
, rl_bitpos
+ rl_bitsize
);
3789 lnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
3790 TYPE_ALIGN (TREE_TYPE (ll_inner
)), word_mode
,
3792 if (lnmode
== VOIDmode
)
3795 lnbitsize
= GET_MODE_BITSIZE (lnmode
);
3796 lnbitpos
= first_bit
& ~ (lnbitsize
- 1);
3797 lntype
= (*lang_hooks
.types
.type_for_size
) (lnbitsize
, 1);
3798 xll_bitpos
= ll_bitpos
- lnbitpos
, xrl_bitpos
= rl_bitpos
- lnbitpos
;
3800 if (BYTES_BIG_ENDIAN
)
3802 xll_bitpos
= lnbitsize
- xll_bitpos
- ll_bitsize
;
3803 xrl_bitpos
= lnbitsize
- xrl_bitpos
- rl_bitsize
;
3806 ll_mask
= const_binop (LSHIFT_EXPR
, convert (lntype
, ll_mask
),
3807 size_int (xll_bitpos
), 0);
3808 rl_mask
= const_binop (LSHIFT_EXPR
, convert (lntype
, rl_mask
),
3809 size_int (xrl_bitpos
), 0);
3813 l_const
= convert (lntype
, l_const
);
3814 l_const
= unextend (l_const
, ll_bitsize
, ll_unsignedp
, ll_and_mask
);
3815 l_const
= const_binop (LSHIFT_EXPR
, l_const
, size_int (xll_bitpos
), 0);
3816 if (! integer_zerop (const_binop (BIT_AND_EXPR
, l_const
,
3817 fold (build1 (BIT_NOT_EXPR
,
3821 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
3823 return convert (truth_type
,
3824 wanted_code
== NE_EXPR
3825 ? integer_one_node
: integer_zero_node
);
3830 r_const
= convert (lntype
, r_const
);
3831 r_const
= unextend (r_const
, rl_bitsize
, rl_unsignedp
, rl_and_mask
);
3832 r_const
= const_binop (LSHIFT_EXPR
, r_const
, size_int (xrl_bitpos
), 0);
3833 if (! integer_zerop (const_binop (BIT_AND_EXPR
, r_const
,
3834 fold (build1 (BIT_NOT_EXPR
,
3838 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
3840 return convert (truth_type
,
3841 wanted_code
== NE_EXPR
3842 ? integer_one_node
: integer_zero_node
);
3846 /* If the right sides are not constant, do the same for it. Also,
3847 disallow this optimization if a size or signedness mismatch occurs
3848 between the left and right sides. */
3851 if (ll_bitsize
!= lr_bitsize
|| rl_bitsize
!= rr_bitsize
3852 || ll_unsignedp
!= lr_unsignedp
|| rl_unsignedp
!= rr_unsignedp
3853 /* Make sure the two fields on the right
3854 correspond to the left without being swapped. */
3855 || ll_bitpos
- rl_bitpos
!= lr_bitpos
- rr_bitpos
)
3858 first_bit
= MIN (lr_bitpos
, rr_bitpos
);
3859 end_bit
= MAX (lr_bitpos
+ lr_bitsize
, rr_bitpos
+ rr_bitsize
);
3860 rnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
3861 TYPE_ALIGN (TREE_TYPE (lr_inner
)), word_mode
,
3863 if (rnmode
== VOIDmode
)
3866 rnbitsize
= GET_MODE_BITSIZE (rnmode
);
3867 rnbitpos
= first_bit
& ~ (rnbitsize
- 1);
3868 rntype
= (*lang_hooks
.types
.type_for_size
) (rnbitsize
, 1);
3869 xlr_bitpos
= lr_bitpos
- rnbitpos
, xrr_bitpos
= rr_bitpos
- rnbitpos
;
3871 if (BYTES_BIG_ENDIAN
)
3873 xlr_bitpos
= rnbitsize
- xlr_bitpos
- lr_bitsize
;
3874 xrr_bitpos
= rnbitsize
- xrr_bitpos
- rr_bitsize
;
3877 lr_mask
= const_binop (LSHIFT_EXPR
, convert (rntype
, lr_mask
),
3878 size_int (xlr_bitpos
), 0);
3879 rr_mask
= const_binop (LSHIFT_EXPR
, convert (rntype
, rr_mask
),
3880 size_int (xrr_bitpos
), 0);
3882 /* Make a mask that corresponds to both fields being compared.
3883 Do this for both items being compared. If the operands are the
3884 same size and the bits being compared are in the same position
3885 then we can do this by masking both and comparing the masked
3887 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
3888 lr_mask
= const_binop (BIT_IOR_EXPR
, lr_mask
, rr_mask
, 0);
3889 if (lnbitsize
== rnbitsize
&& xll_bitpos
== xlr_bitpos
)
3891 lhs
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
3892 ll_unsignedp
|| rl_unsignedp
);
3893 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
3894 lhs
= build (BIT_AND_EXPR
, lntype
, lhs
, ll_mask
);
3896 rhs
= make_bit_field_ref (lr_inner
, rntype
, rnbitsize
, rnbitpos
,
3897 lr_unsignedp
|| rr_unsignedp
);
3898 if (! all_ones_mask_p (lr_mask
, rnbitsize
))
3899 rhs
= build (BIT_AND_EXPR
, rntype
, rhs
, lr_mask
);
3901 return build (wanted_code
, truth_type
, lhs
, rhs
);
3904 /* There is still another way we can do something: If both pairs of
3905 fields being compared are adjacent, we may be able to make a wider
3906 field containing them both.
3908 Note that we still must mask the lhs/rhs expressions. Furthermore,
3909 the mask must be shifted to account for the shift done by
3910 make_bit_field_ref. */
3911 if ((ll_bitsize
+ ll_bitpos
== rl_bitpos
3912 && lr_bitsize
+ lr_bitpos
== rr_bitpos
)
3913 || (ll_bitpos
== rl_bitpos
+ rl_bitsize
3914 && lr_bitpos
== rr_bitpos
+ rr_bitsize
))
3918 lhs
= make_bit_field_ref (ll_inner
, lntype
, ll_bitsize
+ rl_bitsize
,
3919 MIN (ll_bitpos
, rl_bitpos
), ll_unsignedp
);
3920 rhs
= make_bit_field_ref (lr_inner
, rntype
, lr_bitsize
+ rr_bitsize
,
3921 MIN (lr_bitpos
, rr_bitpos
), lr_unsignedp
);
3923 ll_mask
= const_binop (RSHIFT_EXPR
, ll_mask
,
3924 size_int (MIN (xll_bitpos
, xrl_bitpos
)), 0);
3925 lr_mask
= const_binop (RSHIFT_EXPR
, lr_mask
,
3926 size_int (MIN (xlr_bitpos
, xrr_bitpos
)), 0);
3928 /* Convert to the smaller type before masking out unwanted bits. */
3930 if (lntype
!= rntype
)
3932 if (lnbitsize
> rnbitsize
)
3934 lhs
= convert (rntype
, lhs
);
3935 ll_mask
= convert (rntype
, ll_mask
);
3938 else if (lnbitsize
< rnbitsize
)
3940 rhs
= convert (lntype
, rhs
);
3941 lr_mask
= convert (lntype
, lr_mask
);
3946 if (! all_ones_mask_p (ll_mask
, ll_bitsize
+ rl_bitsize
))
3947 lhs
= build (BIT_AND_EXPR
, type
, lhs
, ll_mask
);
3949 if (! all_ones_mask_p (lr_mask
, lr_bitsize
+ rr_bitsize
))
3950 rhs
= build (BIT_AND_EXPR
, type
, rhs
, lr_mask
);
3952 return build (wanted_code
, truth_type
, lhs
, rhs
);
3958 /* Handle the case of comparisons with constants. If there is something in
3959 common between the masks, those bits of the constants must be the same.
3960 If not, the condition is always false. Test for this to avoid generating
3961 incorrect code below. */
3962 result
= const_binop (BIT_AND_EXPR
, ll_mask
, rl_mask
, 0);
3963 if (! integer_zerop (result
)
3964 && simple_cst_equal (const_binop (BIT_AND_EXPR
, result
, l_const
, 0),
3965 const_binop (BIT_AND_EXPR
, result
, r_const
, 0)) != 1)
3967 if (wanted_code
== NE_EXPR
)
3969 warning ("`or' of unmatched not-equal tests is always 1");
3970 return convert (truth_type
, integer_one_node
);
3974 warning ("`and' of mutually exclusive equal-tests is always 0");
3975 return convert (truth_type
, integer_zero_node
);
3979 /* Construct the expression we will return. First get the component
3980 reference we will make. Unless the mask is all ones the width of
3981 that field, perform the mask operation. Then compare with the
3983 result
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
3984 ll_unsignedp
|| rl_unsignedp
);
3986 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
3987 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
3988 result
= build (BIT_AND_EXPR
, lntype
, result
, ll_mask
);
3990 return build (wanted_code
, truth_type
, result
,
3991 const_binop (BIT_IOR_EXPR
, l_const
, r_const
, 0));
3994 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
3998 optimize_minmax_comparison (t
)
4001 tree type
= TREE_TYPE (t
);
4002 tree arg0
= TREE_OPERAND (t
, 0);
4003 enum tree_code op_code
;
4004 tree comp_const
= TREE_OPERAND (t
, 1);
4006 int consts_equal
, consts_lt
;
4009 STRIP_SIGN_NOPS (arg0
);
4011 op_code
= TREE_CODE (arg0
);
4012 minmax_const
= TREE_OPERAND (arg0
, 1);
4013 consts_equal
= tree_int_cst_equal (minmax_const
, comp_const
);
4014 consts_lt
= tree_int_cst_lt (minmax_const
, comp_const
);
4015 inner
= TREE_OPERAND (arg0
, 0);
4017 /* If something does not permit us to optimize, return the original tree. */
4018 if ((op_code
!= MIN_EXPR
&& op_code
!= MAX_EXPR
)
4019 || TREE_CODE (comp_const
) != INTEGER_CST
4020 || TREE_CONSTANT_OVERFLOW (comp_const
)
4021 || TREE_CODE (minmax_const
) != INTEGER_CST
4022 || TREE_CONSTANT_OVERFLOW (minmax_const
))
4025 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4026 and GT_EXPR, doing the rest with recursive calls using logical
4028 switch (TREE_CODE (t
))
4030 case NE_EXPR
: case LT_EXPR
: case LE_EXPR
:
4032 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t
)));
4036 fold (build (TRUTH_ORIF_EXPR
, type
,
4037 optimize_minmax_comparison
4038 (build (EQ_EXPR
, type
, arg0
, comp_const
)),
4039 optimize_minmax_comparison
4040 (build (GT_EXPR
, type
, arg0
, comp_const
))));
4043 if (op_code
== MAX_EXPR
&& consts_equal
)
4044 /* MAX (X, 0) == 0 -> X <= 0 */
4045 return fold (build (LE_EXPR
, type
, inner
, comp_const
));
4047 else if (op_code
== MAX_EXPR
&& consts_lt
)
4048 /* MAX (X, 0) == 5 -> X == 5 */
4049 return fold (build (EQ_EXPR
, type
, inner
, comp_const
));
4051 else if (op_code
== MAX_EXPR
)
4052 /* MAX (X, 0) == -1 -> false */
4053 return omit_one_operand (type
, integer_zero_node
, inner
);
4055 else if (consts_equal
)
4056 /* MIN (X, 0) == 0 -> X >= 0 */
4057 return fold (build (GE_EXPR
, type
, inner
, comp_const
));
4060 /* MIN (X, 0) == 5 -> false */
4061 return omit_one_operand (type
, integer_zero_node
, inner
);
4064 /* MIN (X, 0) == -1 -> X == -1 */
4065 return fold (build (EQ_EXPR
, type
, inner
, comp_const
));
4068 if (op_code
== MAX_EXPR
&& (consts_equal
|| consts_lt
))
4069 /* MAX (X, 0) > 0 -> X > 0
4070 MAX (X, 0) > 5 -> X > 5 */
4071 return fold (build (GT_EXPR
, type
, inner
, comp_const
));
4073 else if (op_code
== MAX_EXPR
)
4074 /* MAX (X, 0) > -1 -> true */
4075 return omit_one_operand (type
, integer_one_node
, inner
);
4077 else if (op_code
== MIN_EXPR
&& (consts_equal
|| consts_lt
))
4078 /* MIN (X, 0) > 0 -> false
4079 MIN (X, 0) > 5 -> false */
4080 return omit_one_operand (type
, integer_zero_node
, inner
);
4083 /* MIN (X, 0) > -1 -> X > -1 */
4084 return fold (build (GT_EXPR
, type
, inner
, comp_const
));
4091 /* T is an integer expression that is being multiplied, divided, or taken a
4092 modulus (CODE says which and what kind of divide or modulus) by a
4093 constant C. See if we can eliminate that operation by folding it with
4094 other operations already in T. WIDE_TYPE, if non-null, is a type that
4095 should be used for the computation if wider than our type.
4097 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4098 (X * 2) + (Y * 4). We must, however, be assured that either the original
4099 expression would not overflow or that overflow is undefined for the type
4100 in the language in question.
4102 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4103 the machine has a multiply-accumulate insn or that this is part of an
4104 addressing calculation.
4106 If we return a non-null expression, it is an equivalent form of the
4107 original computation, but need not be in the original type. */
4110 extract_muldiv (t
, c
, code
, wide_type
)
4113 enum tree_code code
;
4116 /* To avoid exponential search depth, refuse to allow recursion past
4117 three levels. Beyond that (1) it's highly unlikely that we'll find
4118 something interesting and (2) we've probably processed it before
4119 when we built the inner expression. */
4128 ret
= extract_muldiv_1 (t
, c
, code
, wide_type
);
4135 extract_muldiv_1 (t
, c
, code
, wide_type
)
4138 enum tree_code code
;
4141 tree type
= TREE_TYPE (t
);
4142 enum tree_code tcode
= TREE_CODE (t
);
4143 tree ctype
= (wide_type
!= 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type
))
4144 > GET_MODE_SIZE (TYPE_MODE (type
)))
4145 ? wide_type
: type
);
4147 int same_p
= tcode
== code
;
4148 tree op0
= NULL_TREE
, op1
= NULL_TREE
;
4150 /* Don't deal with constants of zero here; they confuse the code below. */
4151 if (integer_zerop (c
))
4154 if (TREE_CODE_CLASS (tcode
) == '1')
4155 op0
= TREE_OPERAND (t
, 0);
4157 if (TREE_CODE_CLASS (tcode
) == '2')
4158 op0
= TREE_OPERAND (t
, 0), op1
= TREE_OPERAND (t
, 1);
4160 /* Note that we need not handle conditional operations here since fold
4161 already handles those cases. So just do arithmetic here. */
4165 /* For a constant, we can always simplify if we are a multiply
4166 or (for divide and modulus) if it is a multiple of our constant. */
4167 if (code
== MULT_EXPR
4168 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, t
, c
, 0)))
4169 return const_binop (code
, convert (ctype
, t
), convert (ctype
, c
), 0);
4172 case CONVERT_EXPR
: case NON_LVALUE_EXPR
: case NOP_EXPR
:
4173 /* If op0 is an expression ... */
4174 if ((TREE_CODE_CLASS (TREE_CODE (op0
)) == '<'
4175 || TREE_CODE_CLASS (TREE_CODE (op0
)) == '1'
4176 || TREE_CODE_CLASS (TREE_CODE (op0
)) == '2'
4177 || TREE_CODE_CLASS (TREE_CODE (op0
)) == 'e')
4178 /* ... and is unsigned, and its type is smaller than ctype,
4179 then we cannot pass through as widening. */
4180 && ((TREE_UNSIGNED (TREE_TYPE (op0
))
4181 && ! (TREE_CODE (TREE_TYPE (op0
)) == INTEGER_TYPE
4182 && TYPE_IS_SIZETYPE (TREE_TYPE (op0
)))
4183 && (GET_MODE_SIZE (TYPE_MODE (ctype
))
4184 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
)))))
4185 /* ... or its type is larger than ctype,
4186 then we cannot pass through this truncation. */
4187 || (GET_MODE_SIZE (TYPE_MODE (ctype
))
4188 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
))))
4189 /* ... or signedness changes for division or modulus,
4190 then we cannot pass through this conversion. */
4191 || (code
!= MULT_EXPR
4192 && (TREE_UNSIGNED (ctype
)
4193 != TREE_UNSIGNED (TREE_TYPE (op0
))))))
4196 /* Pass the constant down and see if we can make a simplification. If
4197 we can, replace this expression with the inner simplification for
4198 possible later conversion to our or some other type. */
4199 if ((t2
= convert (TREE_TYPE (op0
), c
)) != 0
4200 && TREE_CODE (t2
) == INTEGER_CST
4201 && ! TREE_CONSTANT_OVERFLOW (t2
)
4202 && (0 != (t1
= extract_muldiv (op0
, t2
, code
,
4204 ? ctype
: NULL_TREE
))))
4208 case NEGATE_EXPR
: case ABS_EXPR
:
4209 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
4210 return fold (build1 (tcode
, ctype
, convert (ctype
, t1
)));
4213 case MIN_EXPR
: case MAX_EXPR
:
4214 /* If widening the type changes the signedness, then we can't perform
4215 this optimization as that changes the result. */
4216 if (TREE_UNSIGNED (ctype
) != TREE_UNSIGNED (type
))
4219 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4220 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0
4221 && (t2
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
4223 if (tree_int_cst_sgn (c
) < 0)
4224 tcode
= (tcode
== MIN_EXPR
? MAX_EXPR
: MIN_EXPR
);
4226 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4227 convert (ctype
, t2
)));
4231 case WITH_RECORD_EXPR
:
4232 if ((t1
= extract_muldiv (TREE_OPERAND (t
, 0), c
, code
, wide_type
)) != 0)
4233 return build (WITH_RECORD_EXPR
, TREE_TYPE (t1
), t1
,
4234 TREE_OPERAND (t
, 1));
4238 /* If this has not been evaluated and the operand has no side effects,
4239 we can see if we can do something inside it and make a new one.
4240 Note that this test is overly conservative since we can do this
4241 if the only reason it had side effects is that it was another
4242 similar SAVE_EXPR, but that isn't worth bothering with. */
4243 if (SAVE_EXPR_RTL (t
) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 0))
4244 && 0 != (t1
= extract_muldiv (TREE_OPERAND (t
, 0), c
, code
,
4247 t1
= save_expr (t1
);
4248 if (SAVE_EXPR_PERSISTENT_P (t
) && TREE_CODE (t1
) == SAVE_EXPR
)
4249 SAVE_EXPR_PERSISTENT_P (t1
) = 1;
4250 if (is_pending_size (t
))
4251 put_pending_size (t1
);
4256 case LSHIFT_EXPR
: case RSHIFT_EXPR
:
4257 /* If the second operand is constant, this is a multiplication
4258 or floor division, by a power of two, so we can treat it that
4259 way unless the multiplier or divisor overflows. */
4260 if (TREE_CODE (op1
) == INTEGER_CST
4261 /* const_binop may not detect overflow correctly,
4262 so check for it explicitly here. */
4263 && TYPE_PRECISION (TREE_TYPE (size_one_node
)) > TREE_INT_CST_LOW (op1
)
4264 && TREE_INT_CST_HIGH (op1
) == 0
4265 && 0 != (t1
= convert (ctype
,
4266 const_binop (LSHIFT_EXPR
, size_one_node
,
4268 && ! TREE_OVERFLOW (t1
))
4269 return extract_muldiv (build (tcode
== LSHIFT_EXPR
4270 ? MULT_EXPR
: FLOOR_DIV_EXPR
,
4271 ctype
, convert (ctype
, op0
), t1
),
4272 c
, code
, wide_type
);
4275 case PLUS_EXPR
: case MINUS_EXPR
:
4276 /* See if we can eliminate the operation on both sides. If we can, we
4277 can return a new PLUS or MINUS. If we can't, the only remaining
4278 cases where we can do anything are if the second operand is a
4280 t1
= extract_muldiv (op0
, c
, code
, wide_type
);
4281 t2
= extract_muldiv (op1
, c
, code
, wide_type
);
4282 if (t1
!= 0 && t2
!= 0
4283 && (code
== MULT_EXPR
4284 /* If not multiplication, we can only do this if both operands
4285 are divisible by c. */
4286 || (multiple_of_p (ctype
, op0
, c
)
4287 && multiple_of_p (ctype
, op1
, c
))))
4288 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4289 convert (ctype
, t2
)));
4291 /* If this was a subtraction, negate OP1 and set it to be an addition.
4292 This simplifies the logic below. */
4293 if (tcode
== MINUS_EXPR
)
4294 tcode
= PLUS_EXPR
, op1
= negate_expr (op1
);
4296 if (TREE_CODE (op1
) != INTEGER_CST
)
4299 /* If either OP1 or C are negative, this optimization is not safe for
4300 some of the division and remainder types while for others we need
4301 to change the code. */
4302 if (tree_int_cst_sgn (op1
) < 0 || tree_int_cst_sgn (c
) < 0)
4304 if (code
== CEIL_DIV_EXPR
)
4305 code
= FLOOR_DIV_EXPR
;
4306 else if (code
== FLOOR_DIV_EXPR
)
4307 code
= CEIL_DIV_EXPR
;
4308 else if (code
!= MULT_EXPR
4309 && code
!= CEIL_MOD_EXPR
&& code
!= FLOOR_MOD_EXPR
)
4313 /* If it's a multiply or a division/modulus operation of a multiple
4314 of our constant, do the operation and verify it doesn't overflow. */
4315 if (code
== MULT_EXPR
4316 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4318 op1
= const_binop (code
, convert (ctype
, op1
), convert (ctype
, c
), 0);
4319 if (op1
== 0 || TREE_OVERFLOW (op1
))
4325 /* If we have an unsigned type is not a sizetype, we cannot widen
4326 the operation since it will change the result if the original
4327 computation overflowed. */
4328 if (TREE_UNSIGNED (ctype
)
4329 && ! (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
))
4333 /* If we were able to eliminate our operation from the first side,
4334 apply our operation to the second side and reform the PLUS. */
4335 if (t1
!= 0 && (TREE_CODE (t1
) != code
|| code
== MULT_EXPR
))
4336 return fold (build (tcode
, ctype
, convert (ctype
, t1
), op1
));
4338 /* The last case is if we are a multiply. In that case, we can
4339 apply the distributive law to commute the multiply and addition
4340 if the multiplication of the constants doesn't overflow. */
4341 if (code
== MULT_EXPR
)
4342 return fold (build (tcode
, ctype
, fold (build (code
, ctype
,
4343 convert (ctype
, op0
),
4344 convert (ctype
, c
))),
4350 /* We have a special case here if we are doing something like
4351 (C * 8) % 4 since we know that's zero. */
4352 if ((code
== TRUNC_MOD_EXPR
|| code
== CEIL_MOD_EXPR
4353 || code
== FLOOR_MOD_EXPR
|| code
== ROUND_MOD_EXPR
)
4354 && TREE_CODE (TREE_OPERAND (t
, 1)) == INTEGER_CST
4355 && integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4356 return omit_one_operand (type
, integer_zero_node
, op0
);
4358 /* ... fall through ... */
4360 case TRUNC_DIV_EXPR
: case CEIL_DIV_EXPR
: case FLOOR_DIV_EXPR
:
4361 case ROUND_DIV_EXPR
: case EXACT_DIV_EXPR
:
4362 /* If we can extract our operation from the LHS, do so and return a
4363 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4364 do something only if the second operand is a constant. */
4366 && (t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
4367 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4368 convert (ctype
, op1
)));
4369 else if (tcode
== MULT_EXPR
&& code
== MULT_EXPR
4370 && (t1
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
4371 return fold (build (tcode
, ctype
, convert (ctype
, op0
),
4372 convert (ctype
, t1
)));
4373 else if (TREE_CODE (op1
) != INTEGER_CST
)
4376 /* If these are the same operation types, we can associate them
4377 assuming no overflow. */
4379 && 0 != (t1
= const_binop (MULT_EXPR
, convert (ctype
, op1
),
4380 convert (ctype
, c
), 0))
4381 && ! TREE_OVERFLOW (t1
))
4382 return fold (build (tcode
, ctype
, convert (ctype
, op0
), t1
));
4384 /* If these operations "cancel" each other, we have the main
4385 optimizations of this pass, which occur when either constant is a
4386 multiple of the other, in which case we replace this with either an
4387 operation or CODE or TCODE.
4389 If we have an unsigned type that is not a sizetype, we cannot do
4390 this since it will change the result if the original computation
4392 if ((! TREE_UNSIGNED (ctype
)
4393 || (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
)))
4395 && ((code
== MULT_EXPR
&& tcode
== EXACT_DIV_EXPR
)
4396 || (tcode
== MULT_EXPR
4397 && code
!= TRUNC_MOD_EXPR
&& code
!= CEIL_MOD_EXPR
4398 && code
!= FLOOR_MOD_EXPR
&& code
!= ROUND_MOD_EXPR
)))
4400 if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4401 return fold (build (tcode
, ctype
, convert (ctype
, op0
),
4403 const_binop (TRUNC_DIV_EXPR
,
4405 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, c
, op1
, 0)))
4406 return fold (build (code
, ctype
, convert (ctype
, op0
),
4408 const_binop (TRUNC_DIV_EXPR
,
4420 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4421 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4422 that we may sometimes modify the tree. */
4425 strip_compound_expr (t
, s
)
4429 enum tree_code code
= TREE_CODE (t
);
4431 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4432 if (code
== COMPOUND_EXPR
&& TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
4433 && TREE_OPERAND (TREE_OPERAND (t
, 0), 0) == s
)
4434 return TREE_OPERAND (t
, 1);
4436 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4437 don't bother handling any other types. */
4438 else if (code
== COND_EXPR
)
4440 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4441 TREE_OPERAND (t
, 1) = strip_compound_expr (TREE_OPERAND (t
, 1), s
);
4442 TREE_OPERAND (t
, 2) = strip_compound_expr (TREE_OPERAND (t
, 2), s
);
4444 else if (TREE_CODE_CLASS (code
) == '1')
4445 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4446 else if (TREE_CODE_CLASS (code
) == '<'
4447 || TREE_CODE_CLASS (code
) == '2')
4449 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4450 TREE_OPERAND (t
, 1) = strip_compound_expr (TREE_OPERAND (t
, 1), s
);
4456 /* Return a node which has the indicated constant VALUE (either 0 or
4457 1), and is of the indicated TYPE. */
4460 constant_boolean_node (value
, type
)
4464 if (type
== integer_type_node
)
4465 return value
? integer_one_node
: integer_zero_node
;
4466 else if (TREE_CODE (type
) == BOOLEAN_TYPE
)
4467 return (*lang_hooks
.truthvalue_conversion
) (value
? integer_one_node
:
4471 tree t
= build_int_2 (value
, 0);
4473 TREE_TYPE (t
) = type
;
4478 /* Utility function for the following routine, to see how complex a nesting of
4479 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4480 we don't care (to avoid spending too much time on complex expressions.). */
4483 count_cond (expr
, lim
)
4489 if (TREE_CODE (expr
) != COND_EXPR
)
4494 ctrue
= count_cond (TREE_OPERAND (expr
, 1), lim
- 1);
4495 cfalse
= count_cond (TREE_OPERAND (expr
, 2), lim
- 1 - ctrue
);
4496 return MIN (lim
, 1 + ctrue
+ cfalse
);
4499 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
4500 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4501 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4502 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
4503 COND is the first argument to CODE; otherwise (as in the example
4504 given here), it is the second argument. TYPE is the type of the
4505 original expression. */
4508 fold_binary_op_with_conditional_arg (code
, type
, cond
, arg
, cond_first_p
)
4509 enum tree_code code
;
4515 tree test
, true_value
, false_value
;
4516 tree lhs
= NULL_TREE
;
4517 tree rhs
= NULL_TREE
;
4518 /* In the end, we'll produce a COND_EXPR. Both arms of the
4519 conditional expression will be binary operations. The left-hand
4520 side of the expression to be executed if the condition is true
4521 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4522 of the expression to be executed if the condition is true will be
4523 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4524 but apply to the expression to be executed if the conditional is
4530 /* These are the codes to use for the left-hand side and right-hand
4531 side of the COND_EXPR. Normally, they are the same as CODE. */
4532 enum tree_code lhs_code
= code
;
4533 enum tree_code rhs_code
= code
;
4534 /* And these are the types of the expressions. */
4535 tree lhs_type
= type
;
4536 tree rhs_type
= type
;
4541 true_rhs
= false_rhs
= &arg
;
4542 true_lhs
= &true_value
;
4543 false_lhs
= &false_value
;
4547 true_lhs
= false_lhs
= &arg
;
4548 true_rhs
= &true_value
;
4549 false_rhs
= &false_value
;
4552 if (TREE_CODE (cond
) == COND_EXPR
)
4554 test
= TREE_OPERAND (cond
, 0);
4555 true_value
= TREE_OPERAND (cond
, 1);
4556 false_value
= TREE_OPERAND (cond
, 2);
4557 /* If this operand throws an expression, then it does not make
4558 sense to try to perform a logical or arithmetic operation
4559 involving it. Instead of building `a + throw 3' for example,
4560 we simply build `a, throw 3'. */
4561 if (VOID_TYPE_P (TREE_TYPE (true_value
)))
4565 lhs_code
= COMPOUND_EXPR
;
4566 lhs_type
= void_type_node
;
4571 if (VOID_TYPE_P (TREE_TYPE (false_value
)))
4575 rhs_code
= COMPOUND_EXPR
;
4576 rhs_type
= void_type_node
;
4584 tree testtype
= TREE_TYPE (cond
);
4586 true_value
= convert (testtype
, integer_one_node
);
4587 false_value
= convert (testtype
, integer_zero_node
);
4590 /* If ARG is complex we want to make sure we only evaluate it once. Though
4591 this is only required if it is volatile, it might be more efficient even
4592 if it is not. However, if we succeed in folding one part to a constant,
4593 we do not need to make this SAVE_EXPR. Since we do this optimization
4594 primarily to see if we do end up with constant and this SAVE_EXPR
4595 interferes with later optimizations, suppressing it when we can is
4598 If we are not in a function, we can't make a SAVE_EXPR, so don't try to
4599 do so. Don't try to see if the result is a constant if an arm is a
4600 COND_EXPR since we get exponential behavior in that case. */
4602 if (saved_expr_p (arg
))
4604 else if (lhs
== 0 && rhs
== 0
4605 && !TREE_CONSTANT (arg
)
4606 && (*lang_hooks
.decls
.global_bindings_p
) () == 0
4607 && ((TREE_CODE (arg
) != VAR_DECL
&& TREE_CODE (arg
) != PARM_DECL
)
4608 || TREE_SIDE_EFFECTS (arg
)))
4610 if (TREE_CODE (true_value
) != COND_EXPR
)
4611 lhs
= fold (build (lhs_code
, lhs_type
, *true_lhs
, *true_rhs
));
4613 if (TREE_CODE (false_value
) != COND_EXPR
)
4614 rhs
= fold (build (rhs_code
, rhs_type
, *false_lhs
, *false_rhs
));
4616 if ((lhs
== 0 || ! TREE_CONSTANT (lhs
))
4617 && (rhs
== 0 || !TREE_CONSTANT (rhs
)))
4619 arg
= save_expr (arg
);
4626 lhs
= fold (build (lhs_code
, lhs_type
, *true_lhs
, *true_rhs
));
4628 rhs
= fold (build (rhs_code
, rhs_type
, *false_lhs
, *false_rhs
));
4630 test
= fold (build (COND_EXPR
, type
, test
, lhs
, rhs
));
4633 return build (COMPOUND_EXPR
, type
,
4634 convert (void_type_node
, arg
),
4635 strip_compound_expr (test
, arg
));
4637 return convert (type
, test
);
4641 /* Subroutine of fold() that checks for the addition of +/- 0.0.
4643 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
4644 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
4645 ADDEND is the same as X.
4647 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
4648 and finite. The problematic cases are when X is zero, and its mode
4649 has signed zeros. In the case of rounding towards -infinity,
4650 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
4651 modes, X + 0 is not the same as X because -0 + 0 is 0. */
4654 fold_real_zero_addition_p (type
, addend
, negate
)
4658 if (!real_zerop (addend
))
4661 /* Don't allow the fold with -fsignaling-nans. */
4662 if (HONOR_SNANS (TYPE_MODE (type
)))
4665 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
4666 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type
)))
4669 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
4670 if (TREE_CODE (addend
) == REAL_CST
4671 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend
)))
4674 /* The mode has signed zeros, and we have to honor their sign.
4675 In this situation, there is only one case we can return true for.
4676 X - 0 is the same as X unless rounding towards -infinity is
4678 return negate
&& !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type
));
4681 /* Subroutine of fold() that checks comparisons of built-in math
4682 functions against real constants.
4684 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
4685 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
4686 is the type of the result and ARG0 and ARG1 are the operands of the
4687 comparison. ARG1 must be a TREE_REAL_CST.
4689 The function returns the constant folded tree if a simplification
4690 can be made, and NULL_TREE otherwise. */
4693 fold_mathfn_compare (fcode
, code
, type
, arg0
, arg1
)
4694 enum built_in_function fcode
;
4695 enum tree_code code
;
4696 tree type
, arg0
, arg1
;
4700 if (fcode
== BUILT_IN_SQRT
4701 || fcode
== BUILT_IN_SQRTF
4702 || fcode
== BUILT_IN_SQRTL
)
4704 tree arg
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
4705 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (arg0
));
4707 c
= TREE_REAL_CST (arg1
);
4708 if (REAL_VALUE_NEGATIVE (c
))
4710 /* sqrt(x) < y is always false, if y is negative. */
4711 if (code
== EQ_EXPR
|| code
== LT_EXPR
|| code
== LE_EXPR
)
4712 return omit_one_operand (type
,
4713 convert (type
, integer_zero_node
),
4716 /* sqrt(x) > y is always true, if y is negative and we
4717 don't care about NaNs, i.e. negative values of x. */
4718 if (code
== NE_EXPR
|| !HONOR_NANS (mode
))
4719 return omit_one_operand (type
,
4720 convert (type
, integer_one_node
),
4723 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
4724 return fold (build (GE_EXPR
, type
, arg
,
4725 build_real (TREE_TYPE (arg
), dconst0
)));
4727 else if (code
== GT_EXPR
|| code
== GE_EXPR
)
4731 REAL_ARITHMETIC (c2
, MULT_EXPR
, c
, c
);
4732 real_convert (&c2
, mode
, &c2
);
4734 if (REAL_VALUE_ISINF (c2
))
4736 /* sqrt(x) > y is x == +Inf, when y is very large. */
4737 if (HONOR_INFINITIES (mode
))
4738 return fold (build (EQ_EXPR
, type
, arg
,
4739 build_real (TREE_TYPE (arg
), c2
)));
4741 /* sqrt(x) > y is always false, when y is very large
4742 and we don't care about infinities. */
4743 return omit_one_operand (type
,
4744 convert (type
, integer_zero_node
),
4748 /* sqrt(x) > c is the same as x > c*c. */
4749 return fold (build (code
, type
, arg
,
4750 build_real (TREE_TYPE (arg
), c2
)));
4752 else if (code
== LT_EXPR
|| code
== LE_EXPR
)
4756 REAL_ARITHMETIC (c2
, MULT_EXPR
, c
, c
);
4757 real_convert (&c2
, mode
, &c2
);
4759 if (REAL_VALUE_ISINF (c2
))
4761 /* sqrt(x) < y is always true, when y is a very large
4762 value and we don't care about NaNs or Infinities. */
4763 if (! HONOR_NANS (mode
) && ! HONOR_INFINITIES (mode
))
4764 return omit_one_operand (type
,
4765 convert (type
, integer_one_node
),
4768 /* sqrt(x) < y is x != +Inf when y is very large and we
4769 don't care about NaNs. */
4770 if (! HONOR_NANS (mode
))
4771 return fold (build (NE_EXPR
, type
, arg
,
4772 build_real (TREE_TYPE (arg
), c2
)));
4774 /* sqrt(x) < y is x >= 0 when y is very large and we
4775 don't care about Infinities. */
4776 if (! HONOR_INFINITIES (mode
))
4777 return fold (build (GE_EXPR
, type
, arg
,
4778 build_real (TREE_TYPE (arg
), dconst0
)));
4780 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
4781 if ((*lang_hooks
.decls
.global_bindings_p
) () != 0
4782 || CONTAINS_PLACEHOLDER_P (arg
))
4785 arg
= save_expr (arg
);
4786 return fold (build (TRUTH_ANDIF_EXPR
, type
,
4787 fold (build (GE_EXPR
, type
, arg
,
4788 build_real (TREE_TYPE (arg
),
4790 fold (build (NE_EXPR
, type
, arg
,
4791 build_real (TREE_TYPE (arg
),
4795 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
4796 if (! HONOR_NANS (mode
))
4797 return fold (build (code
, type
, arg
,
4798 build_real (TREE_TYPE (arg
), c2
)));
4800 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
4801 if ((*lang_hooks
.decls
.global_bindings_p
) () == 0
4802 && ! CONTAINS_PLACEHOLDER_P (arg
))
4804 arg
= save_expr (arg
);
4805 return fold (build (TRUTH_ANDIF_EXPR
, type
,
4806 fold (build (GE_EXPR
, type
, arg
,
4807 build_real (TREE_TYPE (arg
),
4809 fold (build (code
, type
, arg
,
4810 build_real (TREE_TYPE (arg
),
4819 /* Subroutine of fold() that optimizes comparisons against Infinities,
4820 either +Inf or -Inf.
4822 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
4823 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
4824 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
4826 The function returns the constant folded tree if a simplification
4827 can be made, and NULL_TREE otherwise. */
4830 fold_inf_compare (code
, type
, arg0
, arg1
)
4831 enum tree_code code
;
4832 tree type
, arg0
, arg1
;
4834 enum machine_mode mode
;
4835 REAL_VALUE_TYPE max
;
4839 mode
= TYPE_MODE (TREE_TYPE (arg0
));
4841 /* For negative infinity swap the sense of the comparison. */
4842 neg
= REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1
));
4844 code
= swap_tree_comparison (code
);
4849 /* x > +Inf is always false, if with ignore sNANs. */
4850 if (HONOR_SNANS (mode
))
4852 return omit_one_operand (type
,
4853 convert (type
, integer_zero_node
),
4857 /* x <= +Inf is always true, if we don't case about NaNs. */
4858 if (! HONOR_NANS (mode
))
4859 return omit_one_operand (type
,
4860 convert (type
, integer_one_node
),
4863 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
4864 if ((*lang_hooks
.decls
.global_bindings_p
) () == 0
4865 && ! CONTAINS_PLACEHOLDER_P (arg0
))
4867 arg0
= save_expr (arg0
);
4868 return fold (build (EQ_EXPR
, type
, arg0
, arg0
));
4874 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
4875 real_maxval (&max
, neg
, mode
);
4876 return fold (build (neg
? LT_EXPR
: GT_EXPR
, type
,
4877 arg0
, build_real (TREE_TYPE (arg0
), max
)));
4880 /* x < +Inf is always equal to x <= DBL_MAX. */
4881 real_maxval (&max
, neg
, mode
);
4882 return fold (build (neg
? GE_EXPR
: LE_EXPR
, type
,
4883 arg0
, build_real (TREE_TYPE (arg0
), max
)));
4886 /* x != +Inf is always equal to !(x > DBL_MAX). */
4887 real_maxval (&max
, neg
, mode
);
4888 if (! HONOR_NANS (mode
))
4889 return fold (build (neg
? GE_EXPR
: LE_EXPR
, type
,
4890 arg0
, build_real (TREE_TYPE (arg0
), max
)));
4891 temp
= fold (build (neg
? LT_EXPR
: GT_EXPR
, type
,
4892 arg0
, build_real (TREE_TYPE (arg0
), max
)));
4893 return fold (build1 (TRUTH_NOT_EXPR
, type
, temp
));
4902 /* Perform constant folding and related simplification of EXPR.
4903 The related simplifications include x*1 => x, x*0 => 0, etc.,
4904 and application of the associative law.
4905 NOP_EXPR conversions may be removed freely (as long as we
4906 are careful not to change the C type of the overall expression)
4907 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4908 but we can constant-fold them if they have constant operands. */
4915 tree t1
= NULL_TREE
;
4917 tree type
= TREE_TYPE (expr
);
4918 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
;
4919 enum tree_code code
= TREE_CODE (t
);
4920 int kind
= TREE_CODE_CLASS (code
);
4922 /* WINS will be nonzero when the switch is done
4923 if all operands are constant. */
4926 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4927 Likewise for a SAVE_EXPR that's already been evaluated. */
4928 if (code
== RTL_EXPR
|| (code
== SAVE_EXPR
&& SAVE_EXPR_RTL (t
) != 0))
4931 /* Return right away if a constant. */
4935 #ifdef MAX_INTEGER_COMPUTATION_MODE
4936 check_max_integer_computation_mode (expr
);
4939 if (code
== NOP_EXPR
|| code
== FLOAT_EXPR
|| code
== CONVERT_EXPR
)
4943 /* Special case for conversion ops that can have fixed point args. */
4944 arg0
= TREE_OPERAND (t
, 0);
4946 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4948 STRIP_SIGN_NOPS (arg0
);
4950 if (arg0
!= 0 && TREE_CODE (arg0
) == COMPLEX_CST
)
4951 subop
= TREE_REALPART (arg0
);
4955 if (subop
!= 0 && TREE_CODE (subop
) != INTEGER_CST
4956 && TREE_CODE (subop
) != REAL_CST
4958 /* Note that TREE_CONSTANT isn't enough:
4959 static var addresses are constant but we can't
4960 do arithmetic on them. */
4963 else if (IS_EXPR_CODE_CLASS (kind
) || kind
== 'r')
4965 int len
= first_rtl_op (code
);
4967 for (i
= 0; i
< len
; i
++)
4969 tree op
= TREE_OPERAND (t
, i
);
4973 continue; /* Valid for CALL_EXPR, at least. */
4975 if (kind
== '<' || code
== RSHIFT_EXPR
)
4977 /* Signedness matters here. Perhaps we can refine this
4979 STRIP_SIGN_NOPS (op
);
4982 /* Strip any conversions that don't change the mode. */
4985 if (TREE_CODE (op
) == COMPLEX_CST
)
4986 subop
= TREE_REALPART (op
);
4990 if (TREE_CODE (subop
) != INTEGER_CST
4991 && TREE_CODE (subop
) != REAL_CST
)
4992 /* Note that TREE_CONSTANT isn't enough:
4993 static var addresses are constant but we can't
4994 do arithmetic on them. */
5004 /* If this is a commutative operation, and ARG0 is a constant, move it
5005 to ARG1 to reduce the number of tests below. */
5006 if ((code
== PLUS_EXPR
|| code
== MULT_EXPR
|| code
== MIN_EXPR
5007 || code
== MAX_EXPR
|| code
== BIT_IOR_EXPR
|| code
== BIT_XOR_EXPR
5008 || code
== BIT_AND_EXPR
)
5009 && (TREE_CODE (arg0
) == INTEGER_CST
|| TREE_CODE (arg0
) == REAL_CST
))
5011 tem
= arg0
; arg0
= arg1
; arg1
= tem
;
5013 tem
= TREE_OPERAND (t
, 0); TREE_OPERAND (t
, 0) = TREE_OPERAND (t
, 1);
5014 TREE_OPERAND (t
, 1) = tem
;
5017 /* Now WINS is set as described above,
5018 ARG0 is the first operand of EXPR,
5019 and ARG1 is the second operand (if it has more than one operand).
5021 First check for cases where an arithmetic operation is applied to a
5022 compound, conditional, or comparison operation. Push the arithmetic
5023 operation inside the compound or conditional to see if any folding
5024 can then be done. Convert comparison to conditional for this purpose.
5025 The also optimizes non-constant cases that used to be done in
5028 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
5029 one of the operands is a comparison and the other is a comparison, a
5030 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
5031 code below would make the expression more complex. Change it to a
5032 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
5033 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
5035 if ((code
== BIT_AND_EXPR
|| code
== BIT_IOR_EXPR
5036 || code
== EQ_EXPR
|| code
== NE_EXPR
)
5037 && ((truth_value_p (TREE_CODE (arg0
))
5038 && (truth_value_p (TREE_CODE (arg1
))
5039 || (TREE_CODE (arg1
) == BIT_AND_EXPR
5040 && integer_onep (TREE_OPERAND (arg1
, 1)))))
5041 || (truth_value_p (TREE_CODE (arg1
))
5042 && (truth_value_p (TREE_CODE (arg0
))
5043 || (TREE_CODE (arg0
) == BIT_AND_EXPR
5044 && integer_onep (TREE_OPERAND (arg0
, 1)))))))
5046 t
= fold (build (code
== BIT_AND_EXPR
? TRUTH_AND_EXPR
5047 : code
== BIT_IOR_EXPR
? TRUTH_OR_EXPR
5051 if (code
== EQ_EXPR
)
5052 t
= invert_truthvalue (t
);
5057 if (TREE_CODE_CLASS (code
) == '1')
5059 if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
5060 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5061 fold (build1 (code
, type
, TREE_OPERAND (arg0
, 1))));
5062 else if (TREE_CODE (arg0
) == COND_EXPR
)
5064 tree arg01
= TREE_OPERAND (arg0
, 1);
5065 tree arg02
= TREE_OPERAND (arg0
, 2);
5066 if (! VOID_TYPE_P (TREE_TYPE (arg01
)))
5067 arg01
= fold (build1 (code
, type
, arg01
));
5068 if (! VOID_TYPE_P (TREE_TYPE (arg02
)))
5069 arg02
= fold (build1 (code
, type
, arg02
));
5070 t
= fold (build (COND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5073 /* If this was a conversion, and all we did was to move into
5074 inside the COND_EXPR, bring it back out. But leave it if
5075 it is a conversion from integer to integer and the
5076 result precision is no wider than a word since such a
5077 conversion is cheap and may be optimized away by combine,
5078 while it couldn't if it were outside the COND_EXPR. Then return
5079 so we don't get into an infinite recursion loop taking the
5080 conversion out and then back in. */
5082 if ((code
== NOP_EXPR
|| code
== CONVERT_EXPR
5083 || code
== NON_LVALUE_EXPR
)
5084 && TREE_CODE (t
) == COND_EXPR
5085 && TREE_CODE (TREE_OPERAND (t
, 1)) == code
5086 && TREE_CODE (TREE_OPERAND (t
, 2)) == code
5087 && ! VOID_TYPE_P (TREE_OPERAND (t
, 1))
5088 && ! VOID_TYPE_P (TREE_OPERAND (t
, 2))
5089 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0))
5090 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 2), 0)))
5091 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t
))
5093 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0))))
5094 && TYPE_PRECISION (TREE_TYPE (t
)) <= BITS_PER_WORD
))
5095 t
= build1 (code
, type
,
5097 TREE_TYPE (TREE_OPERAND
5098 (TREE_OPERAND (t
, 1), 0)),
5099 TREE_OPERAND (t
, 0),
5100 TREE_OPERAND (TREE_OPERAND (t
, 1), 0),
5101 TREE_OPERAND (TREE_OPERAND (t
, 2), 0)));
5104 else if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<')
5105 return fold (build (COND_EXPR
, type
, arg0
,
5106 fold (build1 (code
, type
, integer_one_node
)),
5107 fold (build1 (code
, type
, integer_zero_node
))));
5109 else if (TREE_CODE_CLASS (code
) == '<'
5110 && TREE_CODE (arg0
) == COMPOUND_EXPR
)
5111 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5112 fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
5113 else if (TREE_CODE_CLASS (code
) == '<'
5114 && TREE_CODE (arg1
) == COMPOUND_EXPR
)
5115 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
5116 fold (build (code
, type
, arg0
, TREE_OPERAND (arg1
, 1))));
5117 else if (TREE_CODE_CLASS (code
) == '2'
5118 || TREE_CODE_CLASS (code
) == '<')
5120 if (TREE_CODE (arg1
) == COMPOUND_EXPR
5121 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1
, 0))
5122 && ! TREE_SIDE_EFFECTS (arg0
))
5123 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
5124 fold (build (code
, type
,
5125 arg0
, TREE_OPERAND (arg1
, 1))));
5126 else if ((TREE_CODE (arg1
) == COND_EXPR
5127 || (TREE_CODE_CLASS (TREE_CODE (arg1
)) == '<'
5128 && TREE_CODE_CLASS (code
) != '<'))
5129 && (TREE_CODE (arg0
) != COND_EXPR
5130 || count_cond (arg0
, 25) + count_cond (arg1
, 25) <= 25)
5131 && (! TREE_SIDE_EFFECTS (arg0
)
5132 || ((*lang_hooks
.decls
.global_bindings_p
) () == 0
5133 && ! CONTAINS_PLACEHOLDER_P (arg0
))))
5135 fold_binary_op_with_conditional_arg (code
, type
, arg1
, arg0
,
5136 /*cond_first_p=*/0);
5137 else if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
5138 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5139 fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
5140 else if ((TREE_CODE (arg0
) == COND_EXPR
5141 || (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
5142 && TREE_CODE_CLASS (code
) != '<'))
5143 && (TREE_CODE (arg1
) != COND_EXPR
5144 || count_cond (arg0
, 25) + count_cond (arg1
, 25) <= 25)
5145 && (! TREE_SIDE_EFFECTS (arg1
)
5146 || ((*lang_hooks
.decls
.global_bindings_p
) () == 0
5147 && ! CONTAINS_PLACEHOLDER_P (arg1
))))
5149 fold_binary_op_with_conditional_arg (code
, type
, arg0
, arg1
,
5150 /*cond_first_p=*/1);
5164 return fold (DECL_INITIAL (t
));
5169 case FIX_TRUNC_EXPR
:
5170 /* Other kinds of FIX are not handled properly by fold_convert. */
5172 if (TREE_TYPE (TREE_OPERAND (t
, 0)) == TREE_TYPE (t
))
5173 return TREE_OPERAND (t
, 0);
5175 /* Handle cases of two conversions in a row. */
5176 if (TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
5177 || TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
)
5179 tree inside_type
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5180 tree inter_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
5181 tree final_type
= TREE_TYPE (t
);
5182 int inside_int
= INTEGRAL_TYPE_P (inside_type
);
5183 int inside_ptr
= POINTER_TYPE_P (inside_type
);
5184 int inside_float
= FLOAT_TYPE_P (inside_type
);
5185 unsigned int inside_prec
= TYPE_PRECISION (inside_type
);
5186 int inside_unsignedp
= TREE_UNSIGNED (inside_type
);
5187 int inter_int
= INTEGRAL_TYPE_P (inter_type
);
5188 int inter_ptr
= POINTER_TYPE_P (inter_type
);
5189 int inter_float
= FLOAT_TYPE_P (inter_type
);
5190 unsigned int inter_prec
= TYPE_PRECISION (inter_type
);
5191 int inter_unsignedp
= TREE_UNSIGNED (inter_type
);
5192 int final_int
= INTEGRAL_TYPE_P (final_type
);
5193 int final_ptr
= POINTER_TYPE_P (final_type
);
5194 int final_float
= FLOAT_TYPE_P (final_type
);
5195 unsigned int final_prec
= TYPE_PRECISION (final_type
);
5196 int final_unsignedp
= TREE_UNSIGNED (final_type
);
5198 /* In addition to the cases of two conversions in a row
5199 handled below, if we are converting something to its own
5200 type via an object of identical or wider precision, neither
5201 conversion is needed. */
5202 if (TYPE_MAIN_VARIANT (inside_type
) == TYPE_MAIN_VARIANT (final_type
)
5203 && ((inter_int
&& final_int
) || (inter_float
&& final_float
))
5204 && inter_prec
>= final_prec
)
5205 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5207 /* Likewise, if the intermediate and final types are either both
5208 float or both integer, we don't need the middle conversion if
5209 it is wider than the final type and doesn't change the signedness
5210 (for integers). Avoid this if the final type is a pointer
5211 since then we sometimes need the inner conversion. Likewise if
5212 the outer has a precision not equal to the size of its mode. */
5213 if ((((inter_int
|| inter_ptr
) && (inside_int
|| inside_ptr
))
5214 || (inter_float
&& inside_float
))
5215 && inter_prec
>= inside_prec
5216 && (inter_float
|| inter_unsignedp
== inside_unsignedp
)
5217 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (final_type
))
5218 && TYPE_MODE (final_type
) == TYPE_MODE (inter_type
))
5220 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5222 /* If we have a sign-extension of a zero-extended value, we can
5223 replace that by a single zero-extension. */
5224 if (inside_int
&& inter_int
&& final_int
5225 && inside_prec
< inter_prec
&& inter_prec
< final_prec
5226 && inside_unsignedp
&& !inter_unsignedp
)
5227 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5229 /* Two conversions in a row are not needed unless:
5230 - some conversion is floating-point (overstrict for now), or
5231 - the intermediate type is narrower than both initial and
5233 - the intermediate type and innermost type differ in signedness,
5234 and the outermost type is wider than the intermediate, or
5235 - the initial type is a pointer type and the precisions of the
5236 intermediate and final types differ, or
5237 - the final type is a pointer type and the precisions of the
5238 initial and intermediate types differ. */
5239 if (! inside_float
&& ! inter_float
&& ! final_float
5240 && (inter_prec
> inside_prec
|| inter_prec
> final_prec
)
5241 && ! (inside_int
&& inter_int
5242 && inter_unsignedp
!= inside_unsignedp
5243 && inter_prec
< final_prec
)
5244 && ((inter_unsignedp
&& inter_prec
> inside_prec
)
5245 == (final_unsignedp
&& final_prec
> inter_prec
))
5246 && ! (inside_ptr
&& inter_prec
!= final_prec
)
5247 && ! (final_ptr
&& inside_prec
!= inter_prec
)
5248 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (final_type
))
5249 && TYPE_MODE (final_type
) == TYPE_MODE (inter_type
))
5251 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5254 if (TREE_CODE (TREE_OPERAND (t
, 0)) == MODIFY_EXPR
5255 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t
, 0), 1))
5256 /* Detect assigning a bitfield. */
5257 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0)) == COMPONENT_REF
5258 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t
, 0), 0), 1))))
5260 /* Don't leave an assignment inside a conversion
5261 unless assigning a bitfield. */
5262 tree prev
= TREE_OPERAND (t
, 0);
5263 TREE_OPERAND (t
, 0) = TREE_OPERAND (prev
, 1);
5264 /* First do the assignment, then return converted constant. */
5265 t
= build (COMPOUND_EXPR
, TREE_TYPE (t
), prev
, fold (t
));
5270 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
5271 constants (if x has signed type, the sign bit cannot be set
5272 in c). This folds extension into the BIT_AND_EXPR. */
5273 if (INTEGRAL_TYPE_P (TREE_TYPE (t
))
5274 && TREE_CODE (TREE_TYPE (t
)) != BOOLEAN_TYPE
5275 && TREE_CODE (TREE_OPERAND (t
, 0)) == BIT_AND_EXPR
5276 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 1)) == INTEGER_CST
)
5278 tree
and = TREE_OPERAND (t
, 0);
5279 tree and0
= TREE_OPERAND (and, 0), and1
= TREE_OPERAND (and, 1);
5282 if (TREE_UNSIGNED (TREE_TYPE (and))
5283 || (TYPE_PRECISION (TREE_TYPE (t
))
5284 <= TYPE_PRECISION (TREE_TYPE (and))))
5286 else if (TYPE_PRECISION (TREE_TYPE (and1
))
5287 <= HOST_BITS_PER_WIDE_INT
5288 && host_integerp (and1
, 1))
5290 unsigned HOST_WIDE_INT cst
;
5292 cst
= tree_low_cst (and1
, 1);
5293 cst
&= (HOST_WIDE_INT
) -1
5294 << (TYPE_PRECISION (TREE_TYPE (and1
)) - 1);
5295 change
= (cst
== 0);
5296 #ifdef LOAD_EXTEND_OP
5298 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0
)))
5301 tree uns
= (*lang_hooks
.types
.unsigned_type
) (TREE_TYPE (and0
));
5302 and0
= convert (uns
, and0
);
5303 and1
= convert (uns
, and1
);
5308 return fold (build (BIT_AND_EXPR
, TREE_TYPE (t
),
5309 convert (TREE_TYPE (t
), and0
),
5310 convert (TREE_TYPE (t
), and1
)));
5315 TREE_CONSTANT (t
) = TREE_CONSTANT (arg0
);
5318 return fold_convert (t
, arg0
);
5320 case VIEW_CONVERT_EXPR
:
5321 if (TREE_CODE (TREE_OPERAND (t
, 0)) == VIEW_CONVERT_EXPR
)
5322 return build1 (VIEW_CONVERT_EXPR
, type
,
5323 TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5327 if (TREE_CODE (arg0
) == CONSTRUCTOR
5328 && ! type_contains_placeholder_p (TREE_TYPE (arg0
)))
5330 tree m
= purpose_member (arg1
, CONSTRUCTOR_ELTS (arg0
));
5337 TREE_CONSTANT (t
) = wins
;
5343 if (TREE_CODE (arg0
) == INTEGER_CST
)
5345 unsigned HOST_WIDE_INT low
;
5347 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
5348 TREE_INT_CST_HIGH (arg0
),
5350 t
= build_int_2 (low
, high
);
5351 TREE_TYPE (t
) = type
;
5353 = (TREE_OVERFLOW (arg0
)
5354 | force_fit_type (t
, overflow
&& !TREE_UNSIGNED (type
)));
5355 TREE_CONSTANT_OVERFLOW (t
)
5356 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg0
);
5358 else if (TREE_CODE (arg0
) == REAL_CST
)
5359 t
= build_real (type
, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
5361 else if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5362 return TREE_OPERAND (arg0
, 0);
5363 /* Convert -((double)float) into (double)(-float). */
5364 else if (TREE_CODE (arg0
) == NOP_EXPR
5365 && TREE_CODE (type
) == REAL_TYPE
)
5367 tree targ0
= strip_float_extensions (arg0
);
5369 return convert (type
, build1 (NEGATE_EXPR
, TREE_TYPE (targ0
), targ0
));
5373 /* Convert - (a - b) to (b - a) for non-floating-point. */
5374 else if (TREE_CODE (arg0
) == MINUS_EXPR
5375 && (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
))
5376 return build (MINUS_EXPR
, type
, TREE_OPERAND (arg0
, 1),
5377 TREE_OPERAND (arg0
, 0));
5379 /* Convert -f(x) into f(-x) where f is sin, tan or atan. */
5380 switch (builtin_mathfn_code (arg0
))
5389 case BUILT_IN_ATANF
:
5390 case BUILT_IN_ATANL
:
5391 if (negate_expr_p (TREE_VALUE (TREE_OPERAND (arg0
, 1))))
5393 tree fndecl
, arg
, arglist
;
5395 fndecl
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
5396 arg
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
5397 arg
= fold (build1 (NEGATE_EXPR
, type
, arg
));
5398 arglist
= build_tree_list (NULL_TREE
, arg
);
5399 return build_function_call_expr (fndecl
, arglist
);
5411 if (TREE_CODE (arg0
) == INTEGER_CST
)
5413 /* If the value is unsigned, then the absolute value is
5414 the same as the ordinary value. */
5415 if (TREE_UNSIGNED (type
))
5417 /* Similarly, if the value is non-negative. */
5418 else if (INT_CST_LT (integer_minus_one_node
, arg0
))
5420 /* If the value is negative, then the absolute value is
5424 unsigned HOST_WIDE_INT low
;
5426 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
5427 TREE_INT_CST_HIGH (arg0
),
5429 t
= build_int_2 (low
, high
);
5430 TREE_TYPE (t
) = type
;
5432 = (TREE_OVERFLOW (arg0
)
5433 | force_fit_type (t
, overflow
));
5434 TREE_CONSTANT_OVERFLOW (t
)
5435 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg0
);
5438 else if (TREE_CODE (arg0
) == REAL_CST
)
5440 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0
)))
5441 t
= build_real (type
,
5442 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
5445 else if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5446 return fold (build1 (ABS_EXPR
, type
, TREE_OPERAND (arg0
, 0)));
5447 /* Convert fabs((double)float) into (double)fabsf(float). */
5448 else if (TREE_CODE (arg0
) == NOP_EXPR
5449 && TREE_CODE (type
) == REAL_TYPE
)
5451 tree targ0
= strip_float_extensions (arg0
);
5453 return convert (type
, fold (build1 (ABS_EXPR
, TREE_TYPE (targ0
),
5456 else if (tree_expr_nonnegative_p (arg0
))
5461 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
5462 return convert (type
, arg0
);
5463 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
5464 return build (COMPLEX_EXPR
, type
,
5465 TREE_OPERAND (arg0
, 0),
5466 negate_expr (TREE_OPERAND (arg0
, 1)));
5467 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
5468 return build_complex (type
, TREE_REALPART (arg0
),
5469 negate_expr (TREE_IMAGPART (arg0
)));
5470 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
5471 return fold (build (TREE_CODE (arg0
), type
,
5472 fold (build1 (CONJ_EXPR
, type
,
5473 TREE_OPERAND (arg0
, 0))),
5474 fold (build1 (CONJ_EXPR
,
5475 type
, TREE_OPERAND (arg0
, 1)))));
5476 else if (TREE_CODE (arg0
) == CONJ_EXPR
)
5477 return TREE_OPERAND (arg0
, 0);
5483 t
= build_int_2 (~ TREE_INT_CST_LOW (arg0
),
5484 ~ TREE_INT_CST_HIGH (arg0
));
5485 TREE_TYPE (t
) = type
;
5486 force_fit_type (t
, 0);
5487 TREE_OVERFLOW (t
) = TREE_OVERFLOW (arg0
);
5488 TREE_CONSTANT_OVERFLOW (t
) = TREE_CONSTANT_OVERFLOW (arg0
);
5490 else if (TREE_CODE (arg0
) == BIT_NOT_EXPR
)
5491 return TREE_OPERAND (arg0
, 0);
5495 /* A + (-B) -> A - B */
5496 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
5497 return fold (build (MINUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
5498 /* (-A) + B -> B - A */
5499 if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5500 return fold (build (MINUS_EXPR
, type
, arg1
, TREE_OPERAND (arg0
, 0)));
5501 else if (! FLOAT_TYPE_P (type
))
5503 if (integer_zerop (arg1
))
5504 return non_lvalue (convert (type
, arg0
));
5506 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5507 with a constant, and the two constants have no bits in common,
5508 we should treat this as a BIT_IOR_EXPR since this may produce more
5510 if (TREE_CODE (arg0
) == BIT_AND_EXPR
5511 && TREE_CODE (arg1
) == BIT_AND_EXPR
5512 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
5513 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
5514 && integer_zerop (const_binop (BIT_AND_EXPR
,
5515 TREE_OPERAND (arg0
, 1),
5516 TREE_OPERAND (arg1
, 1), 0)))
5518 code
= BIT_IOR_EXPR
;
5522 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5523 (plus (plus (mult) (mult)) (foo)) so that we can
5524 take advantage of the factoring cases below. */
5525 if ((TREE_CODE (arg0
) == PLUS_EXPR
5526 && TREE_CODE (arg1
) == MULT_EXPR
)
5527 || (TREE_CODE (arg1
) == PLUS_EXPR
5528 && TREE_CODE (arg0
) == MULT_EXPR
))
5530 tree parg0
, parg1
, parg
, marg
;
5532 if (TREE_CODE (arg0
) == PLUS_EXPR
)
5533 parg
= arg0
, marg
= arg1
;
5535 parg
= arg1
, marg
= arg0
;
5536 parg0
= TREE_OPERAND (parg
, 0);
5537 parg1
= TREE_OPERAND (parg
, 1);
5541 if (TREE_CODE (parg0
) == MULT_EXPR
5542 && TREE_CODE (parg1
) != MULT_EXPR
)
5543 return fold (build (PLUS_EXPR
, type
,
5544 fold (build (PLUS_EXPR
, type
,
5545 convert (type
, parg0
),
5546 convert (type
, marg
))),
5547 convert (type
, parg1
)));
5548 if (TREE_CODE (parg0
) != MULT_EXPR
5549 && TREE_CODE (parg1
) == MULT_EXPR
)
5550 return fold (build (PLUS_EXPR
, type
,
5551 fold (build (PLUS_EXPR
, type
,
5552 convert (type
, parg1
),
5553 convert (type
, marg
))),
5554 convert (type
, parg0
)));
5557 if (TREE_CODE (arg0
) == MULT_EXPR
&& TREE_CODE (arg1
) == MULT_EXPR
)
5559 tree arg00
, arg01
, arg10
, arg11
;
5560 tree alt0
= NULL_TREE
, alt1
= NULL_TREE
, same
;
5562 /* (A * C) + (B * C) -> (A+B) * C.
5563 We are most concerned about the case where C is a constant,
5564 but other combinations show up during loop reduction. Since
5565 it is not difficult, try all four possibilities. */
5567 arg00
= TREE_OPERAND (arg0
, 0);
5568 arg01
= TREE_OPERAND (arg0
, 1);
5569 arg10
= TREE_OPERAND (arg1
, 0);
5570 arg11
= TREE_OPERAND (arg1
, 1);
5573 if (operand_equal_p (arg01
, arg11
, 0))
5574 same
= arg01
, alt0
= arg00
, alt1
= arg10
;
5575 else if (operand_equal_p (arg00
, arg10
, 0))
5576 same
= arg00
, alt0
= arg01
, alt1
= arg11
;
5577 else if (operand_equal_p (arg00
, arg11
, 0))
5578 same
= arg00
, alt0
= arg01
, alt1
= arg10
;
5579 else if (operand_equal_p (arg01
, arg10
, 0))
5580 same
= arg01
, alt0
= arg00
, alt1
= arg11
;
5582 /* No identical multiplicands; see if we can find a common
5583 power-of-two factor in non-power-of-two multiplies. This
5584 can help in multi-dimensional array access. */
5585 else if (TREE_CODE (arg01
) == INTEGER_CST
5586 && TREE_CODE (arg11
) == INTEGER_CST
5587 && TREE_INT_CST_HIGH (arg01
) == 0
5588 && TREE_INT_CST_HIGH (arg11
) == 0)
5590 HOST_WIDE_INT int01
, int11
, tmp
;
5591 int01
= TREE_INT_CST_LOW (arg01
);
5592 int11
= TREE_INT_CST_LOW (arg11
);
5594 /* Move min of absolute values to int11. */
5595 if ((int01
>= 0 ? int01
: -int01
)
5596 < (int11
>= 0 ? int11
: -int11
))
5598 tmp
= int01
, int01
= int11
, int11
= tmp
;
5599 alt0
= arg00
, arg00
= arg10
, arg10
= alt0
;
5600 alt0
= arg01
, arg01
= arg11
, arg11
= alt0
;
5603 if (exact_log2 (int11
) > 0 && int01
% int11
== 0)
5605 alt0
= fold (build (MULT_EXPR
, type
, arg00
,
5606 build_int_2 (int01
/ int11
, 0)));
5613 return fold (build (MULT_EXPR
, type
,
5614 fold (build (PLUS_EXPR
, type
, alt0
, alt1
)),
5619 /* See if ARG1 is zero and X + ARG1 reduces to X. */
5620 else if (fold_real_zero_addition_p (TREE_TYPE (arg0
), arg1
, 0))
5621 return non_lvalue (convert (type
, arg0
));
5623 /* Likewise if the operands are reversed. */
5624 else if (fold_real_zero_addition_p (TREE_TYPE (arg1
), arg0
, 0))
5625 return non_lvalue (convert (type
, arg1
));
5628 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5629 is a rotate of A by C1 bits. */
5630 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5631 is a rotate of A by B bits. */
5633 enum tree_code code0
, code1
;
5634 code0
= TREE_CODE (arg0
);
5635 code1
= TREE_CODE (arg1
);
5636 if (((code0
== RSHIFT_EXPR
&& code1
== LSHIFT_EXPR
)
5637 || (code1
== RSHIFT_EXPR
&& code0
== LSHIFT_EXPR
))
5638 && operand_equal_p (TREE_OPERAND (arg0
, 0),
5639 TREE_OPERAND (arg1
, 0), 0)
5640 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
5642 tree tree01
, tree11
;
5643 enum tree_code code01
, code11
;
5645 tree01
= TREE_OPERAND (arg0
, 1);
5646 tree11
= TREE_OPERAND (arg1
, 1);
5647 STRIP_NOPS (tree01
);
5648 STRIP_NOPS (tree11
);
5649 code01
= TREE_CODE (tree01
);
5650 code11
= TREE_CODE (tree11
);
5651 if (code01
== INTEGER_CST
5652 && code11
== INTEGER_CST
5653 && TREE_INT_CST_HIGH (tree01
) == 0
5654 && TREE_INT_CST_HIGH (tree11
) == 0
5655 && ((TREE_INT_CST_LOW (tree01
) + TREE_INT_CST_LOW (tree11
))
5656 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)))))
5657 return build (LROTATE_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5658 code0
== LSHIFT_EXPR
? tree01
: tree11
);
5659 else if (code11
== MINUS_EXPR
)
5661 tree tree110
, tree111
;
5662 tree110
= TREE_OPERAND (tree11
, 0);
5663 tree111
= TREE_OPERAND (tree11
, 1);
5664 STRIP_NOPS (tree110
);
5665 STRIP_NOPS (tree111
);
5666 if (TREE_CODE (tree110
) == INTEGER_CST
5667 && 0 == compare_tree_int (tree110
,
5669 (TREE_TYPE (TREE_OPERAND
5671 && operand_equal_p (tree01
, tree111
, 0))
5672 return build ((code0
== LSHIFT_EXPR
5675 type
, TREE_OPERAND (arg0
, 0), tree01
);
5677 else if (code01
== MINUS_EXPR
)
5679 tree tree010
, tree011
;
5680 tree010
= TREE_OPERAND (tree01
, 0);
5681 tree011
= TREE_OPERAND (tree01
, 1);
5682 STRIP_NOPS (tree010
);
5683 STRIP_NOPS (tree011
);
5684 if (TREE_CODE (tree010
) == INTEGER_CST
5685 && 0 == compare_tree_int (tree010
,
5687 (TREE_TYPE (TREE_OPERAND
5689 && operand_equal_p (tree11
, tree011
, 0))
5690 return build ((code0
!= LSHIFT_EXPR
5693 type
, TREE_OPERAND (arg0
, 0), tree11
);
5699 /* In most languages, can't associate operations on floats through
5700 parentheses. Rather than remember where the parentheses were, we
5701 don't associate floats at all. It shouldn't matter much. However,
5702 associating multiplications is only very slightly inaccurate, so do
5703 that if -funsafe-math-optimizations is specified. */
5706 && (! FLOAT_TYPE_P (type
)
5707 || (flag_unsafe_math_optimizations
&& code
== MULT_EXPR
)))
5709 tree var0
, con0
, lit0
, minus_lit0
;
5710 tree var1
, con1
, lit1
, minus_lit1
;
5712 /* Split both trees into variables, constants, and literals. Then
5713 associate each group together, the constants with literals,
5714 then the result with variables. This increases the chances of
5715 literals being recombined later and of generating relocatable
5716 expressions for the sum of a constant and literal. */
5717 var0
= split_tree (arg0
, code
, &con0
, &lit0
, &minus_lit0
, 0);
5718 var1
= split_tree (arg1
, code
, &con1
, &lit1
, &minus_lit1
,
5719 code
== MINUS_EXPR
);
5721 /* Only do something if we found more than two objects. Otherwise,
5722 nothing has changed and we risk infinite recursion. */
5723 if (2 < ((var0
!= 0) + (var1
!= 0)
5724 + (con0
!= 0) + (con1
!= 0)
5725 + (lit0
!= 0) + (lit1
!= 0)
5726 + (minus_lit0
!= 0) + (minus_lit1
!= 0)))
5728 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
5729 if (code
== MINUS_EXPR
)
5732 var0
= associate_trees (var0
, var1
, code
, type
);
5733 con0
= associate_trees (con0
, con1
, code
, type
);
5734 lit0
= associate_trees (lit0
, lit1
, code
, type
);
5735 minus_lit0
= associate_trees (minus_lit0
, minus_lit1
, code
, type
);
5737 /* Preserve the MINUS_EXPR if the negative part of the literal is
5738 greater than the positive part. Otherwise, the multiplicative
5739 folding code (i.e extract_muldiv) may be fooled in case
5740 unsigned constants are substracted, like in the following
5741 example: ((X*2 + 4) - 8U)/2. */
5742 if (minus_lit0
&& lit0
)
5744 if (tree_int_cst_lt (lit0
, minus_lit0
))
5746 minus_lit0
= associate_trees (minus_lit0
, lit0
,
5752 lit0
= associate_trees (lit0
, minus_lit0
,
5760 return convert (type
, associate_trees (var0
, minus_lit0
,
5764 con0
= associate_trees (con0
, minus_lit0
,
5766 return convert (type
, associate_trees (var0
, con0
,
5771 con0
= associate_trees (con0
, lit0
, code
, type
);
5772 return convert (type
, associate_trees (var0
, con0
, code
, type
));
5778 t1
= const_binop (code
, arg0
, arg1
, 0);
5779 if (t1
!= NULL_TREE
)
5781 /* The return value should always have
5782 the same type as the original expression. */
5783 if (TREE_TYPE (t1
) != TREE_TYPE (t
))
5784 t1
= convert (TREE_TYPE (t
), t1
);
5791 /* A - (-B) -> A + B */
5792 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
5793 return fold (build (PLUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
5794 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
5795 if (TREE_CODE (arg0
) == NEGATE_EXPR
5796 && (FLOAT_TYPE_P (type
)
5797 || (INTEGRAL_TYPE_P (type
) && flag_wrapv
&& !flag_trapv
))
5798 && negate_expr_p (arg1
)
5799 && (! TREE_SIDE_EFFECTS (arg0
) || TREE_CONSTANT (arg1
))
5800 && (! TREE_SIDE_EFFECTS (arg1
) || TREE_CONSTANT (arg0
)))
5801 return fold (build (MINUS_EXPR
, type
, negate_expr (arg1
),
5802 TREE_OPERAND (arg0
, 0)));
5804 if (! FLOAT_TYPE_P (type
))
5806 if (! wins
&& integer_zerop (arg0
))
5807 return negate_expr (convert (type
, arg1
));
5808 if (integer_zerop (arg1
))
5809 return non_lvalue (convert (type
, arg0
));
5811 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5812 about the case where C is a constant, just try one of the
5813 four possibilities. */
5815 if (TREE_CODE (arg0
) == MULT_EXPR
&& TREE_CODE (arg1
) == MULT_EXPR
5816 && operand_equal_p (TREE_OPERAND (arg0
, 1),
5817 TREE_OPERAND (arg1
, 1), 0))
5818 return fold (build (MULT_EXPR
, type
,
5819 fold (build (MINUS_EXPR
, type
,
5820 TREE_OPERAND (arg0
, 0),
5821 TREE_OPERAND (arg1
, 0))),
5822 TREE_OPERAND (arg0
, 1)));
5824 /* Fold A - (A & B) into ~B & A. */
5825 if (!TREE_SIDE_EFFECTS (arg0
)
5826 && TREE_CODE (arg1
) == BIT_AND_EXPR
)
5828 if (operand_equal_p (arg0
, TREE_OPERAND (arg1
, 1), 0))
5829 return fold (build (BIT_AND_EXPR
, type
,
5830 fold (build1 (BIT_NOT_EXPR
, type
,
5831 TREE_OPERAND (arg1
, 0))),
5833 if (operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
5834 return fold (build (BIT_AND_EXPR
, type
,
5835 fold (build1 (BIT_NOT_EXPR
, type
,
5836 TREE_OPERAND (arg1
, 1))),
5841 /* See if ARG1 is zero and X - ARG1 reduces to X. */
5842 else if (fold_real_zero_addition_p (TREE_TYPE (arg0
), arg1
, 1))
5843 return non_lvalue (convert (type
, arg0
));
5845 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
5846 ARG0 is zero and X + ARG0 reduces to X, since that would mean
5847 (-ARG1 + ARG0) reduces to -ARG1. */
5848 else if (!wins
&& fold_real_zero_addition_p (TREE_TYPE (arg1
), arg0
, 0))
5849 return negate_expr (convert (type
, arg1
));
5851 /* Fold &x - &x. This can happen from &x.foo - &x.
5852 This is unsafe for certain floats even in non-IEEE formats.
5853 In IEEE, it is unsafe because it does wrong for NaNs.
5854 Also note that operand_equal_p is always false if an operand
5857 if ((! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
5858 && operand_equal_p (arg0
, arg1
, 0))
5859 return convert (type
, integer_zero_node
);
5864 /* (-A) * (-B) -> A * B */
5865 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == NEGATE_EXPR
)
5866 return fold (build (MULT_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5867 TREE_OPERAND (arg1
, 0)));
5869 if (! FLOAT_TYPE_P (type
))
5871 if (integer_zerop (arg1
))
5872 return omit_one_operand (type
, arg1
, arg0
);
5873 if (integer_onep (arg1
))
5874 return non_lvalue (convert (type
, arg0
));
5876 /* (a * (1 << b)) is (a << b) */
5877 if (TREE_CODE (arg1
) == LSHIFT_EXPR
5878 && integer_onep (TREE_OPERAND (arg1
, 0)))
5879 return fold (build (LSHIFT_EXPR
, type
, arg0
,
5880 TREE_OPERAND (arg1
, 1)));
5881 if (TREE_CODE (arg0
) == LSHIFT_EXPR
5882 && integer_onep (TREE_OPERAND (arg0
, 0)))
5883 return fold (build (LSHIFT_EXPR
, type
, arg1
,
5884 TREE_OPERAND (arg0
, 1)));
5886 if (TREE_CODE (arg1
) == INTEGER_CST
5887 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0),
5888 convert (type
, arg1
),
5890 return convert (type
, tem
);
5895 /* Maybe fold x * 0 to 0. The expressions aren't the same
5896 when x is NaN, since x * 0 is also NaN. Nor are they the
5897 same in modes with signed zeros, since multiplying a
5898 negative value by 0 gives -0, not +0. */
5899 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
)))
5900 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0
)))
5901 && real_zerop (arg1
))
5902 return omit_one_operand (type
, arg1
, arg0
);
5903 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
5904 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
5905 && real_onep (arg1
))
5906 return non_lvalue (convert (type
, arg0
));
5908 /* Transform x * -1.0 into -x. */
5909 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
5910 && real_minus_onep (arg1
))
5911 return fold (build1 (NEGATE_EXPR
, type
, arg0
));
5914 if (! wins
&& real_twop (arg1
)
5915 && (*lang_hooks
.decls
.global_bindings_p
) () == 0
5916 && ! CONTAINS_PLACEHOLDER_P (arg0
))
5918 tree arg
= save_expr (arg0
);
5919 return fold (build (PLUS_EXPR
, type
, arg
, arg
));
5922 if (flag_unsafe_math_optimizations
)
5924 enum built_in_function fcode0
= builtin_mathfn_code (arg0
);
5925 enum built_in_function fcode1
= builtin_mathfn_code (arg1
);
5927 /* Optimizations of sqrt(...)*sqrt(...). */
5928 if ((fcode0
== BUILT_IN_SQRT
&& fcode1
== BUILT_IN_SQRT
)
5929 || (fcode0
== BUILT_IN_SQRTF
&& fcode1
== BUILT_IN_SQRTF
)
5930 || (fcode0
== BUILT_IN_SQRTL
&& fcode1
== BUILT_IN_SQRTL
))
5932 tree sqrtfn
, arg
, arglist
;
5933 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
5934 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
5936 /* Optimize sqrt(x)*sqrt(x) as x. */
5937 if (operand_equal_p (arg00
, arg10
, 0)
5938 && ! HONOR_SNANS (TYPE_MODE (type
)))
5941 /* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */
5942 sqrtfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
5943 arg
= fold (build (MULT_EXPR
, type
, arg00
, arg10
));
5944 arglist
= build_tree_list (NULL_TREE
, arg
);
5945 return build_function_call_expr (sqrtfn
, arglist
);
5948 /* Optimize exp(x)*exp(y) as exp(x+y). */
5949 if ((fcode0
== BUILT_IN_EXP
&& fcode1
== BUILT_IN_EXP
)
5950 || (fcode0
== BUILT_IN_EXPF
&& fcode1
== BUILT_IN_EXPF
)
5951 || (fcode0
== BUILT_IN_EXPL
&& fcode1
== BUILT_IN_EXPL
))
5953 tree expfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
5954 tree arg
= build (PLUS_EXPR
, type
,
5955 TREE_VALUE (TREE_OPERAND (arg0
, 1)),
5956 TREE_VALUE (TREE_OPERAND (arg1
, 1)));
5957 tree arglist
= build_tree_list (NULL_TREE
, fold (arg
));
5958 return build_function_call_expr (expfn
, arglist
);
5961 /* Optimizations of pow(...)*pow(...). */
5962 if ((fcode0
== BUILT_IN_POW
&& fcode1
== BUILT_IN_POW
)
5963 || (fcode0
== BUILT_IN_POWF
&& fcode1
== BUILT_IN_POWF
)
5964 || (fcode0
== BUILT_IN_POWL
&& fcode1
== BUILT_IN_POWL
))
5966 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
5967 tree arg01
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0
,
5969 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
5970 tree arg11
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1
,
5973 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
5974 if (operand_equal_p (arg01
, arg11
, 0))
5976 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
5977 tree arg
= build (MULT_EXPR
, type
, arg00
, arg10
);
5978 tree arglist
= tree_cons (NULL_TREE
, fold (arg
),
5979 build_tree_list (NULL_TREE
,
5981 return build_function_call_expr (powfn
, arglist
);
5984 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
5985 if (operand_equal_p (arg00
, arg10
, 0))
5987 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
5988 tree arg
= fold (build (PLUS_EXPR
, type
, arg01
, arg11
));
5989 tree arglist
= tree_cons (NULL_TREE
, arg00
,
5990 build_tree_list (NULL_TREE
,
5992 return build_function_call_expr (powfn
, arglist
);
5996 /* Optimize tan(x)*cos(x) as sin(x). */
5997 if (((fcode0
== BUILT_IN_TAN
&& fcode1
== BUILT_IN_COS
)
5998 || (fcode0
== BUILT_IN_TANF
&& fcode1
== BUILT_IN_COSF
)
5999 || (fcode0
== BUILT_IN_TANL
&& fcode1
== BUILT_IN_COSL
)
6000 || (fcode0
== BUILT_IN_COS
&& fcode1
== BUILT_IN_TAN
)
6001 || (fcode0
== BUILT_IN_COSF
&& fcode1
== BUILT_IN_TANF
)
6002 || (fcode0
== BUILT_IN_COSL
&& fcode1
== BUILT_IN_TANL
))
6003 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0
, 1)),
6004 TREE_VALUE (TREE_OPERAND (arg1
, 1)), 0))
6012 sinfn
= implicit_built_in_decls
[BUILT_IN_SIN
];
6016 sinfn
= implicit_built_in_decls
[BUILT_IN_SINF
];
6020 sinfn
= implicit_built_in_decls
[BUILT_IN_SINL
];
6026 if (sinfn
!= NULL_TREE
)
6027 return build_function_call_expr (sinfn
,
6028 TREE_OPERAND (arg0
, 1));
6036 if (integer_all_onesp (arg1
))
6037 return omit_one_operand (type
, arg1
, arg0
);
6038 if (integer_zerop (arg1
))
6039 return non_lvalue (convert (type
, arg0
));
6040 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
6041 if (t1
!= NULL_TREE
)
6044 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
6046 This results in more efficient code for machines without a NAND
6047 instruction. Combine will canonicalize to the first form
6048 which will allow use of NAND instructions provided by the
6049 backend if they exist. */
6050 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
6051 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
6053 return fold (build1 (BIT_NOT_EXPR
, type
,
6054 build (BIT_AND_EXPR
, type
,
6055 TREE_OPERAND (arg0
, 0),
6056 TREE_OPERAND (arg1
, 0))));
6059 /* See if this can be simplified into a rotate first. If that
6060 is unsuccessful continue in the association code. */
6064 if (integer_zerop (arg1
))
6065 return non_lvalue (convert (type
, arg0
));
6066 if (integer_all_onesp (arg1
))
6067 return fold (build1 (BIT_NOT_EXPR
, type
, arg0
));
6069 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
6070 with a constant, and the two constants have no bits in common,
6071 we should treat this as a BIT_IOR_EXPR since this may produce more
6073 if (TREE_CODE (arg0
) == BIT_AND_EXPR
6074 && TREE_CODE (arg1
) == BIT_AND_EXPR
6075 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
6076 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
6077 && integer_zerop (const_binop (BIT_AND_EXPR
,
6078 TREE_OPERAND (arg0
, 1),
6079 TREE_OPERAND (arg1
, 1), 0)))
6081 code
= BIT_IOR_EXPR
;
6085 /* See if this can be simplified into a rotate first. If that
6086 is unsuccessful continue in the association code. */
6091 if (integer_all_onesp (arg1
))
6092 return non_lvalue (convert (type
, arg0
));
6093 if (integer_zerop (arg1
))
6094 return omit_one_operand (type
, arg1
, arg0
);
6095 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
6096 if (t1
!= NULL_TREE
)
6098 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
6099 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) == NOP_EXPR
6100 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
6103 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)));
6105 if (prec
< BITS_PER_WORD
&& prec
< HOST_BITS_PER_WIDE_INT
6106 && (~TREE_INT_CST_LOW (arg1
)
6107 & (((HOST_WIDE_INT
) 1 << prec
) - 1)) == 0)
6108 return build1 (NOP_EXPR
, type
, TREE_OPERAND (arg0
, 0));
6111 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
6113 This results in more efficient code for machines without a NOR
6114 instruction. Combine will canonicalize to the first form
6115 which will allow use of NOR instructions provided by the
6116 backend if they exist. */
6117 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
6118 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
6120 return fold (build1 (BIT_NOT_EXPR
, type
,
6121 build (BIT_IOR_EXPR
, type
,
6122 TREE_OPERAND (arg0
, 0),
6123 TREE_OPERAND (arg1
, 0))));
6128 case BIT_ANDTC_EXPR
:
6129 if (integer_all_onesp (arg0
))
6130 return non_lvalue (convert (type
, arg1
));
6131 if (integer_zerop (arg0
))
6132 return omit_one_operand (type
, arg0
, arg1
);
6133 if (TREE_CODE (arg1
) == INTEGER_CST
)
6135 arg1
= fold (build1 (BIT_NOT_EXPR
, type
, arg1
));
6136 code
= BIT_AND_EXPR
;
6142 /* Don't touch a floating-point divide by zero unless the mode
6143 of the constant can represent infinity. */
6144 if (TREE_CODE (arg1
) == REAL_CST
6145 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1
)))
6146 && real_zerop (arg1
))
6149 /* (-A) / (-B) -> A / B */
6150 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == NEGATE_EXPR
)
6151 return fold (build (RDIV_EXPR
, type
, TREE_OPERAND (arg0
, 0),
6152 TREE_OPERAND (arg1
, 0)));
6154 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
6155 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
6156 && real_onep (arg1
))
6157 return non_lvalue (convert (type
, arg0
));
6159 /* If ARG1 is a constant, we can convert this to a multiply by the
6160 reciprocal. This does not have the same rounding properties,
6161 so only do this if -funsafe-math-optimizations. We can actually
6162 always safely do it if ARG1 is a power of two, but it's hard to
6163 tell if it is or not in a portable manner. */
6164 if (TREE_CODE (arg1
) == REAL_CST
)
6166 if (flag_unsafe_math_optimizations
6167 && 0 != (tem
= const_binop (code
, build_real (type
, dconst1
),
6169 return fold (build (MULT_EXPR
, type
, arg0
, tem
));
6170 /* Find the reciprocal if optimizing and the result is exact. */
6174 r
= TREE_REAL_CST (arg1
);
6175 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0
)), &r
))
6177 tem
= build_real (type
, r
);
6178 return fold (build (MULT_EXPR
, type
, arg0
, tem
));
6182 /* Convert A/B/C to A/(B*C). */
6183 if (flag_unsafe_math_optimizations
6184 && TREE_CODE (arg0
) == RDIV_EXPR
)
6186 return fold (build (RDIV_EXPR
, type
, TREE_OPERAND (arg0
, 0),
6187 build (MULT_EXPR
, type
, TREE_OPERAND (arg0
, 1),
6190 /* Convert A/(B/C) to (A/B)*C. */
6191 if (flag_unsafe_math_optimizations
6192 && TREE_CODE (arg1
) == RDIV_EXPR
)
6194 return fold (build (MULT_EXPR
, type
,
6195 build (RDIV_EXPR
, type
, arg0
,
6196 TREE_OPERAND (arg1
, 0)),
6197 TREE_OPERAND (arg1
, 1)));
6200 if (flag_unsafe_math_optimizations
)
6202 enum built_in_function fcode
= builtin_mathfn_code (arg1
);
6203 /* Optimize x/exp(y) into x*exp(-y). */
6204 if (fcode
== BUILT_IN_EXP
6205 || fcode
== BUILT_IN_EXPF
6206 || fcode
== BUILT_IN_EXPL
)
6208 tree expfn
= TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0);
6209 tree arg
= build1 (NEGATE_EXPR
, type
,
6210 TREE_VALUE (TREE_OPERAND (arg1
, 1)));
6211 tree arglist
= build_tree_list (NULL_TREE
, fold (arg
));
6212 arg1
= build_function_call_expr (expfn
, arglist
);
6213 return fold (build (MULT_EXPR
, type
, arg0
, arg1
));
6216 /* Optimize x/pow(y,z) into x*pow(y,-z). */
6217 if (fcode
== BUILT_IN_POW
6218 || fcode
== BUILT_IN_POWF
6219 || fcode
== BUILT_IN_POWL
)
6221 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0);
6222 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
6223 tree arg11
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1
, 1)));
6224 tree neg11
= fold (build1 (NEGATE_EXPR
, type
, arg11
));
6225 tree arglist
= tree_cons(NULL_TREE
, arg10
,
6226 build_tree_list (NULL_TREE
, neg11
));
6227 arg1
= build_function_call_expr (powfn
, arglist
);
6228 return fold (build (MULT_EXPR
, type
, arg0
, arg1
));
6232 if (flag_unsafe_math_optimizations
)
6234 enum built_in_function fcode0
= builtin_mathfn_code (arg0
);
6235 enum built_in_function fcode1
= builtin_mathfn_code (arg1
);
6237 /* Optimize sin(x)/cos(x) as tan(x). */
6238 if (((fcode0
== BUILT_IN_SIN
&& fcode1
== BUILT_IN_COS
)
6239 || (fcode0
== BUILT_IN_SINF
&& fcode1
== BUILT_IN_COSF
)
6240 || (fcode0
== BUILT_IN_SINL
&& fcode1
== BUILT_IN_COSL
))
6241 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0
, 1)),
6242 TREE_VALUE (TREE_OPERAND (arg1
, 1)), 0))
6246 if (fcode0
== BUILT_IN_SIN
)
6247 tanfn
= implicit_built_in_decls
[BUILT_IN_TAN
];
6248 else if (fcode0
== BUILT_IN_SINF
)
6249 tanfn
= implicit_built_in_decls
[BUILT_IN_TANF
];
6250 else if (fcode0
== BUILT_IN_SINL
)
6251 tanfn
= implicit_built_in_decls
[BUILT_IN_TANL
];
6255 if (tanfn
!= NULL_TREE
)
6256 return build_function_call_expr (tanfn
,
6257 TREE_OPERAND (arg0
, 1));
6260 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
6261 if (((fcode0
== BUILT_IN_COS
&& fcode1
== BUILT_IN_SIN
)
6262 || (fcode0
== BUILT_IN_COSF
&& fcode1
== BUILT_IN_SINF
)
6263 || (fcode0
== BUILT_IN_COSL
&& fcode1
== BUILT_IN_SINL
))
6264 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0
, 1)),
6265 TREE_VALUE (TREE_OPERAND (arg1
, 1)), 0))
6269 if (fcode0
== BUILT_IN_COS
)
6270 tanfn
= implicit_built_in_decls
[BUILT_IN_TAN
];
6271 else if (fcode0
== BUILT_IN_COSF
)
6272 tanfn
= implicit_built_in_decls
[BUILT_IN_TANF
];
6273 else if (fcode0
== BUILT_IN_COSL
)
6274 tanfn
= implicit_built_in_decls
[BUILT_IN_TANL
];
6278 if (tanfn
!= NULL_TREE
)
6280 tree tmp
= TREE_OPERAND (arg0
, 1);
6281 tmp
= build_function_call_expr (tanfn
, tmp
);
6282 return fold (build (RDIV_EXPR
, type
,
6283 build_real (type
, dconst1
),
6290 case TRUNC_DIV_EXPR
:
6291 case ROUND_DIV_EXPR
:
6292 case FLOOR_DIV_EXPR
:
6294 case EXACT_DIV_EXPR
:
6295 if (integer_onep (arg1
))
6296 return non_lvalue (convert (type
, arg0
));
6297 if (integer_zerop (arg1
))
6300 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
6301 operation, EXACT_DIV_EXPR.
6303 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
6304 At one time others generated faster code, it's not clear if they do
6305 after the last round to changes to the DIV code in expmed.c. */
6306 if ((code
== CEIL_DIV_EXPR
|| code
== FLOOR_DIV_EXPR
)
6307 && multiple_of_p (type
, arg0
, arg1
))
6308 return fold (build (EXACT_DIV_EXPR
, type
, arg0
, arg1
));
6310 if (TREE_CODE (arg1
) == INTEGER_CST
6311 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
6313 return convert (type
, tem
);
6318 case FLOOR_MOD_EXPR
:
6319 case ROUND_MOD_EXPR
:
6320 case TRUNC_MOD_EXPR
:
6321 if (integer_onep (arg1
))
6322 return omit_one_operand (type
, integer_zero_node
, arg0
);
6323 if (integer_zerop (arg1
))
6326 if (TREE_CODE (arg1
) == INTEGER_CST
6327 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
6329 return convert (type
, tem
);
6335 if (integer_all_onesp (arg0
))
6336 return omit_one_operand (type
, arg0
, arg1
);
6340 /* Optimize -1 >> x for arithmetic right shifts. */
6341 if (integer_all_onesp (arg0
) && ! TREE_UNSIGNED (type
))
6342 return omit_one_operand (type
, arg0
, arg1
);
6343 /* ... fall through ... */
6347 if (integer_zerop (arg1
))
6348 return non_lvalue (convert (type
, arg0
));
6349 if (integer_zerop (arg0
))
6350 return omit_one_operand (type
, arg0
, arg1
);
6352 /* Since negative shift count is not well-defined,
6353 don't try to compute it in the compiler. */
6354 if (TREE_CODE (arg1
) == INTEGER_CST
&& tree_int_cst_sgn (arg1
) < 0)
6356 /* Rewrite an LROTATE_EXPR by a constant into an
6357 RROTATE_EXPR by a new constant. */
6358 if (code
== LROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
)
6360 TREE_SET_CODE (t
, RROTATE_EXPR
);
6361 code
= RROTATE_EXPR
;
6362 TREE_OPERAND (t
, 1) = arg1
6365 convert (TREE_TYPE (arg1
),
6366 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type
)), 0)),
6368 if (tree_int_cst_sgn (arg1
) < 0)
6372 /* If we have a rotate of a bit operation with the rotate count and
6373 the second operand of the bit operation both constant,
6374 permute the two operations. */
6375 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
6376 && (TREE_CODE (arg0
) == BIT_AND_EXPR
6377 || TREE_CODE (arg0
) == BIT_ANDTC_EXPR
6378 || TREE_CODE (arg0
) == BIT_IOR_EXPR
6379 || TREE_CODE (arg0
) == BIT_XOR_EXPR
)
6380 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
6381 return fold (build (TREE_CODE (arg0
), type
,
6382 fold (build (code
, type
,
6383 TREE_OPERAND (arg0
, 0), arg1
)),
6384 fold (build (code
, type
,
6385 TREE_OPERAND (arg0
, 1), arg1
))));
6387 /* Two consecutive rotates adding up to the width of the mode can
6389 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
6390 && TREE_CODE (arg0
) == RROTATE_EXPR
6391 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
6392 && TREE_INT_CST_HIGH (arg1
) == 0
6393 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0
, 1)) == 0
6394 && ((TREE_INT_CST_LOW (arg1
)
6395 + TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1)))
6396 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type
))))
6397 return TREE_OPERAND (arg0
, 0);
6402 if (operand_equal_p (arg0
, arg1
, 0))
6403 return omit_one_operand (type
, arg0
, arg1
);
6404 if (INTEGRAL_TYPE_P (type
)
6405 && operand_equal_p (arg1
, TYPE_MIN_VALUE (type
), 1))
6406 return omit_one_operand (type
, arg1
, arg0
);
6410 if (operand_equal_p (arg0
, arg1
, 0))
6411 return omit_one_operand (type
, arg0
, arg1
);
6412 if (INTEGRAL_TYPE_P (type
)
6413 && TYPE_MAX_VALUE (type
)
6414 && operand_equal_p (arg1
, TYPE_MAX_VALUE (type
), 1))
6415 return omit_one_operand (type
, arg1
, arg0
);
6418 case TRUTH_NOT_EXPR
:
6419 /* Note that the operand of this must be an int
6420 and its values must be 0 or 1.
6421 ("true" is a fixed value perhaps depending on the language,
6422 but we don't handle values other than 1 correctly yet.) */
6423 tem
= invert_truthvalue (arg0
);
6424 /* Avoid infinite recursion. */
6425 if (TREE_CODE (tem
) == TRUTH_NOT_EXPR
)
6427 return convert (type
, tem
);
6429 case TRUTH_ANDIF_EXPR
:
6430 /* Note that the operands of this must be ints
6431 and their values must be 0 or 1.
6432 ("true" is a fixed value perhaps depending on the language.) */
6433 /* If first arg is constant zero, return it. */
6434 if (integer_zerop (arg0
))
6435 return convert (type
, arg0
);
6436 case TRUTH_AND_EXPR
:
6437 /* If either arg is constant true, drop it. */
6438 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6439 return non_lvalue (convert (type
, arg1
));
6440 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
)
6441 /* Preserve sequence points. */
6442 && (code
!= TRUTH_ANDIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
6443 return non_lvalue (convert (type
, arg0
));
6444 /* If second arg is constant zero, result is zero, but first arg
6445 must be evaluated. */
6446 if (integer_zerop (arg1
))
6447 return omit_one_operand (type
, arg1
, arg0
);
6448 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
6449 case will be handled here. */
6450 if (integer_zerop (arg0
))
6451 return omit_one_operand (type
, arg0
, arg1
);
6454 /* We only do these simplifications if we are optimizing. */
6458 /* Check for things like (A || B) && (A || C). We can convert this
6459 to A || (B && C). Note that either operator can be any of the four
6460 truth and/or operations and the transformation will still be
6461 valid. Also note that we only care about order for the
6462 ANDIF and ORIF operators. If B contains side effects, this
6463 might change the truth-value of A. */
6464 if (TREE_CODE (arg0
) == TREE_CODE (arg1
)
6465 && (TREE_CODE (arg0
) == TRUTH_ANDIF_EXPR
6466 || TREE_CODE (arg0
) == TRUTH_ORIF_EXPR
6467 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
6468 || TREE_CODE (arg0
) == TRUTH_OR_EXPR
)
6469 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0
, 1)))
6471 tree a00
= TREE_OPERAND (arg0
, 0);
6472 tree a01
= TREE_OPERAND (arg0
, 1);
6473 tree a10
= TREE_OPERAND (arg1
, 0);
6474 tree a11
= TREE_OPERAND (arg1
, 1);
6475 int commutative
= ((TREE_CODE (arg0
) == TRUTH_OR_EXPR
6476 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
)
6477 && (code
== TRUTH_AND_EXPR
6478 || code
== TRUTH_OR_EXPR
));
6480 if (operand_equal_p (a00
, a10
, 0))
6481 return fold (build (TREE_CODE (arg0
), type
, a00
,
6482 fold (build (code
, type
, a01
, a11
))));
6483 else if (commutative
&& operand_equal_p (a00
, a11
, 0))
6484 return fold (build (TREE_CODE (arg0
), type
, a00
,
6485 fold (build (code
, type
, a01
, a10
))));
6486 else if (commutative
&& operand_equal_p (a01
, a10
, 0))
6487 return fold (build (TREE_CODE (arg0
), type
, a01
,
6488 fold (build (code
, type
, a00
, a11
))));
6490 /* This case if tricky because we must either have commutative
6491 operators or else A10 must not have side-effects. */
6493 else if ((commutative
|| ! TREE_SIDE_EFFECTS (a10
))
6494 && operand_equal_p (a01
, a11
, 0))
6495 return fold (build (TREE_CODE (arg0
), type
,
6496 fold (build (code
, type
, a00
, a10
)),
6500 /* See if we can build a range comparison. */
6501 if (0 != (tem
= fold_range_test (t
)))
6504 /* Check for the possibility of merging component references. If our
6505 lhs is another similar operation, try to merge its rhs with our
6506 rhs. Then try to merge our lhs and rhs. */
6507 if (TREE_CODE (arg0
) == code
6508 && 0 != (tem
= fold_truthop (code
, type
,
6509 TREE_OPERAND (arg0
, 1), arg1
)))
6510 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6512 if ((tem
= fold_truthop (code
, type
, arg0
, arg1
)) != 0)
6517 case TRUTH_ORIF_EXPR
:
6518 /* Note that the operands of this must be ints
6519 and their values must be 0 or true.
6520 ("true" is a fixed value perhaps depending on the language.) */
6521 /* If first arg is constant true, return it. */
6522 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6523 return convert (type
, arg0
);
6525 /* If either arg is constant zero, drop it. */
6526 if (TREE_CODE (arg0
) == INTEGER_CST
&& integer_zerop (arg0
))
6527 return non_lvalue (convert (type
, arg1
));
6528 if (TREE_CODE (arg1
) == INTEGER_CST
&& integer_zerop (arg1
)
6529 /* Preserve sequence points. */
6530 && (code
!= TRUTH_ORIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
6531 return non_lvalue (convert (type
, arg0
));
6532 /* If second arg is constant true, result is true, but we must
6533 evaluate first arg. */
6534 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
))
6535 return omit_one_operand (type
, arg1
, arg0
);
6536 /* Likewise for first arg, but note this only occurs here for
6538 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6539 return omit_one_operand (type
, arg0
, arg1
);
6542 case TRUTH_XOR_EXPR
:
6543 /* If either arg is constant zero, drop it. */
6544 if (integer_zerop (arg0
))
6545 return non_lvalue (convert (type
, arg1
));
6546 if (integer_zerop (arg1
))
6547 return non_lvalue (convert (type
, arg0
));
6548 /* If either arg is constant true, this is a logical inversion. */
6549 if (integer_onep (arg0
))
6550 return non_lvalue (convert (type
, invert_truthvalue (arg1
)));
6551 if (integer_onep (arg1
))
6552 return non_lvalue (convert (type
, invert_truthvalue (arg0
)));
6561 /* If one arg is a real or integer constant, put it last. */
6562 if ((TREE_CODE (arg0
) == INTEGER_CST
6563 && TREE_CODE (arg1
) != INTEGER_CST
)
6564 || (TREE_CODE (arg0
) == REAL_CST
6565 && TREE_CODE (arg0
) != REAL_CST
))
6567 TREE_OPERAND (t
, 0) = arg1
;
6568 TREE_OPERAND (t
, 1) = arg0
;
6569 arg0
= TREE_OPERAND (t
, 0);
6570 arg1
= TREE_OPERAND (t
, 1);
6571 code
= swap_tree_comparison (code
);
6572 TREE_SET_CODE (t
, code
);
6575 if (FLOAT_TYPE_P (TREE_TYPE (arg0
)))
6577 tree targ0
= strip_float_extensions (arg0
);
6578 tree targ1
= strip_float_extensions (arg1
);
6579 tree newtype
= TREE_TYPE (targ0
);
6581 if (TYPE_PRECISION (TREE_TYPE (targ1
)) > TYPE_PRECISION (newtype
))
6582 newtype
= TREE_TYPE (targ1
);
6584 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
6585 if (TYPE_PRECISION (newtype
) < TYPE_PRECISION (TREE_TYPE (arg0
)))
6586 return fold (build (code
, type
, convert (newtype
, targ0
),
6587 convert (newtype
, targ1
)));
6589 /* (-a) CMP (-b) -> b CMP a */
6590 if (TREE_CODE (arg0
) == NEGATE_EXPR
6591 && TREE_CODE (arg1
) == NEGATE_EXPR
)
6592 return fold (build (code
, type
, TREE_OPERAND (arg1
, 0),
6593 TREE_OPERAND (arg0
, 0)));
6595 if (TREE_CODE (arg1
) == REAL_CST
)
6597 REAL_VALUE_TYPE cst
;
6598 cst
= TREE_REAL_CST (arg1
);
6600 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6601 if (TREE_CODE (arg0
) == NEGATE_EXPR
)
6603 fold (build (swap_tree_comparison (code
), type
,
6604 TREE_OPERAND (arg0
, 0),
6605 build_real (TREE_TYPE (arg1
),
6606 REAL_VALUE_NEGATE (cst
))));
6608 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6609 /* a CMP (-0) -> a CMP 0 */
6610 if (REAL_VALUE_MINUS_ZERO (cst
))
6611 return fold (build (code
, type
, arg0
,
6612 build_real (TREE_TYPE (arg1
), dconst0
)));
6614 /* x != NaN is always true, other ops are always false. */
6615 if (REAL_VALUE_ISNAN (cst
)
6616 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1
))))
6618 t
= (code
== NE_EXPR
) ? integer_one_node
: integer_zero_node
;
6619 return omit_one_operand (type
, convert (type
, t
), arg0
);
6622 /* Fold comparisons against infinity. */
6623 if (REAL_VALUE_ISINF (cst
))
6625 tem
= fold_inf_compare (code
, type
, arg0
, arg1
);
6626 if (tem
!= NULL_TREE
)
6631 /* If this is a comparison of a real constant with a PLUS_EXPR
6632 or a MINUS_EXPR of a real constant, we can convert it into a
6633 comparison with a revised real constant as long as no overflow
6634 occurs when unsafe_math_optimizations are enabled. */
6635 if (flag_unsafe_math_optimizations
6636 && TREE_CODE (arg1
) == REAL_CST
6637 && (TREE_CODE (arg0
) == PLUS_EXPR
6638 || TREE_CODE (arg0
) == MINUS_EXPR
)
6639 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == REAL_CST
6640 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
6641 ? MINUS_EXPR
: PLUS_EXPR
,
6642 arg1
, TREE_OPERAND (arg0
, 1), 0))
6643 && ! TREE_CONSTANT_OVERFLOW (tem
))
6644 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6646 /* Likewise, we can simplify a comparison of a real constant with
6647 a MINUS_EXPR whose first operand is also a real constant, i.e.
6648 (c1 - x) < c2 becomes x > c1-c2. */
6649 if (flag_unsafe_math_optimizations
6650 && TREE_CODE (arg1
) == REAL_CST
6651 && TREE_CODE (arg0
) == MINUS_EXPR
6652 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == REAL_CST
6653 && 0 != (tem
= const_binop (MINUS_EXPR
, TREE_OPERAND (arg0
, 0),
6655 && ! TREE_CONSTANT_OVERFLOW (tem
))
6656 return fold (build (swap_tree_comparison (code
), type
,
6657 TREE_OPERAND (arg0
, 1), tem
));
6659 /* Fold comparisons against built-in math functions. */
6660 if (TREE_CODE (arg1
) == REAL_CST
6661 && flag_unsafe_math_optimizations
6662 && ! flag_errno_math
)
6664 enum built_in_function fcode
= builtin_mathfn_code (arg0
);
6666 if (fcode
!= END_BUILTINS
)
6668 tem
= fold_mathfn_compare (fcode
, code
, type
, arg0
, arg1
);
6669 if (tem
!= NULL_TREE
)
6675 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6676 First, see if one arg is constant; find the constant arg
6677 and the other one. */
6679 tree constop
= 0, varop
= NULL_TREE
;
6680 int constopnum
= -1;
6682 if (TREE_CONSTANT (arg1
))
6683 constopnum
= 1, constop
= arg1
, varop
= arg0
;
6684 if (TREE_CONSTANT (arg0
))
6685 constopnum
= 0, constop
= arg0
, varop
= arg1
;
6687 if (constop
&& TREE_CODE (varop
) == POSTINCREMENT_EXPR
)
6689 /* This optimization is invalid for ordered comparisons
6690 if CONST+INCR overflows or if foo+incr might overflow.
6691 This optimization is invalid for floating point due to rounding.
6692 For pointer types we assume overflow doesn't happen. */
6693 if (POINTER_TYPE_P (TREE_TYPE (varop
))
6694 || (! FLOAT_TYPE_P (TREE_TYPE (varop
))
6695 && (code
== EQ_EXPR
|| code
== NE_EXPR
)))
6698 = fold (build (PLUS_EXPR
, TREE_TYPE (varop
),
6699 constop
, TREE_OPERAND (varop
, 1)));
6701 /* Do not overwrite the current varop to be a preincrement,
6702 create a new node so that we won't confuse our caller who
6703 might create trees and throw them away, reusing the
6704 arguments that they passed to build. This shows up in
6705 the THEN or ELSE parts of ?: being postincrements. */
6706 varop
= build (PREINCREMENT_EXPR
, TREE_TYPE (varop
),
6707 TREE_OPERAND (varop
, 0),
6708 TREE_OPERAND (varop
, 1));
6710 /* If VAROP is a reference to a bitfield, we must mask
6711 the constant by the width of the field. */
6712 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
6713 && DECL_BIT_FIELD(TREE_OPERAND
6714 (TREE_OPERAND (varop
, 0), 1)))
6717 = TREE_INT_CST_LOW (DECL_SIZE
6719 (TREE_OPERAND (varop
, 0), 1)));
6720 tree mask
, unsigned_type
;
6721 unsigned int precision
;
6722 tree folded_compare
;
6724 /* First check whether the comparison would come out
6725 always the same. If we don't do that we would
6726 change the meaning with the masking. */
6727 if (constopnum
== 0)
6728 folded_compare
= fold (build (code
, type
, constop
,
6729 TREE_OPERAND (varop
, 0)));
6731 folded_compare
= fold (build (code
, type
,
6732 TREE_OPERAND (varop
, 0),
6734 if (integer_zerop (folded_compare
)
6735 || integer_onep (folded_compare
))
6736 return omit_one_operand (type
, folded_compare
, varop
);
6738 unsigned_type
= (*lang_hooks
.types
.type_for_size
)(size
, 1);
6739 precision
= TYPE_PRECISION (unsigned_type
);
6740 mask
= build_int_2 (~0, ~0);
6741 TREE_TYPE (mask
) = unsigned_type
;
6742 force_fit_type (mask
, 0);
6743 mask
= const_binop (RSHIFT_EXPR
, mask
,
6744 size_int (precision
- size
), 0);
6745 newconst
= fold (build (BIT_AND_EXPR
,
6746 TREE_TYPE (varop
), newconst
,
6747 convert (TREE_TYPE (varop
),
6751 t
= build (code
, type
,
6752 (constopnum
== 0) ? newconst
: varop
,
6753 (constopnum
== 1) ? newconst
: varop
);
6757 else if (constop
&& TREE_CODE (varop
) == POSTDECREMENT_EXPR
)
6759 if (POINTER_TYPE_P (TREE_TYPE (varop
))
6760 || (! FLOAT_TYPE_P (TREE_TYPE (varop
))
6761 && (code
== EQ_EXPR
|| code
== NE_EXPR
)))
6764 = fold (build (MINUS_EXPR
, TREE_TYPE (varop
),
6765 constop
, TREE_OPERAND (varop
, 1)));
6767 /* Do not overwrite the current varop to be a predecrement,
6768 create a new node so that we won't confuse our caller who
6769 might create trees and throw them away, reusing the
6770 arguments that they passed to build. This shows up in
6771 the THEN or ELSE parts of ?: being postdecrements. */
6772 varop
= build (PREDECREMENT_EXPR
, TREE_TYPE (varop
),
6773 TREE_OPERAND (varop
, 0),
6774 TREE_OPERAND (varop
, 1));
6776 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
6777 && DECL_BIT_FIELD(TREE_OPERAND
6778 (TREE_OPERAND (varop
, 0), 1)))
6781 = TREE_INT_CST_LOW (DECL_SIZE
6783 (TREE_OPERAND (varop
, 0), 1)));
6784 tree mask
, unsigned_type
;
6785 unsigned int precision
;
6786 tree folded_compare
;
6788 if (constopnum
== 0)
6789 folded_compare
= fold (build (code
, type
, constop
,
6790 TREE_OPERAND (varop
, 0)));
6792 folded_compare
= fold (build (code
, type
,
6793 TREE_OPERAND (varop
, 0),
6795 if (integer_zerop (folded_compare
)
6796 || integer_onep (folded_compare
))
6797 return omit_one_operand (type
, folded_compare
, varop
);
6799 unsigned_type
= (*lang_hooks
.types
.type_for_size
)(size
, 1);
6800 precision
= TYPE_PRECISION (unsigned_type
);
6801 mask
= build_int_2 (~0, ~0);
6802 TREE_TYPE (mask
) = TREE_TYPE (varop
);
6803 force_fit_type (mask
, 0);
6804 mask
= const_binop (RSHIFT_EXPR
, mask
,
6805 size_int (precision
- size
), 0);
6806 newconst
= fold (build (BIT_AND_EXPR
,
6807 TREE_TYPE (varop
), newconst
,
6808 convert (TREE_TYPE (varop
),
6812 t
= build (code
, type
,
6813 (constopnum
== 0) ? newconst
: varop
,
6814 (constopnum
== 1) ? newconst
: varop
);
6820 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
6821 This transformation affects the cases which are handled in later
6822 optimizations involving comparisons with non-negative constants. */
6823 if (TREE_CODE (arg1
) == INTEGER_CST
6824 && TREE_CODE (arg0
) != INTEGER_CST
6825 && tree_int_cst_sgn (arg1
) > 0)
6831 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6832 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6837 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6838 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6846 /* Comparisons with the highest or lowest possible integer of
6847 the specified size will have known values. */
6849 int width
= GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1
)));
6851 if (TREE_CODE (arg1
) == INTEGER_CST
6852 && ! TREE_CONSTANT_OVERFLOW (arg1
)
6853 && width
<= HOST_BITS_PER_WIDE_INT
6854 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
6855 || POINTER_TYPE_P (TREE_TYPE (arg1
))))
6857 unsigned HOST_WIDE_INT signed_max
;
6858 unsigned HOST_WIDE_INT max
, min
;
6860 signed_max
= ((unsigned HOST_WIDE_INT
) 1 << (width
- 1)) - 1;
6862 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
6864 max
= ((unsigned HOST_WIDE_INT
) 2 << (width
- 1)) - 1;
6870 min
= ((unsigned HOST_WIDE_INT
) -1 << (width
- 1));
6873 if (TREE_INT_CST_HIGH (arg1
) == 0
6874 && TREE_INT_CST_LOW (arg1
) == max
)
6878 return omit_one_operand (type
,
6879 convert (type
, integer_zero_node
),
6883 TREE_SET_CODE (t
, EQ_EXPR
);
6886 return omit_one_operand (type
,
6887 convert (type
, integer_one_node
),
6891 TREE_SET_CODE (t
, NE_EXPR
);
6894 /* The GE_EXPR and LT_EXPR cases above are not normally
6895 reached because of previous transformations. */
6900 else if (TREE_INT_CST_HIGH (arg1
) == 0
6901 && TREE_INT_CST_LOW (arg1
) == max
- 1)
6906 arg1
= const_binop (PLUS_EXPR
, arg1
, integer_one_node
, 0);
6907 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6911 arg1
= const_binop (PLUS_EXPR
, arg1
, integer_one_node
, 0);
6912 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6917 else if (TREE_INT_CST_HIGH (arg1
) == (min
? -1 : 0)
6918 && TREE_INT_CST_LOW (arg1
) == min
)
6922 return omit_one_operand (type
,
6923 convert (type
, integer_zero_node
),
6927 TREE_SET_CODE (t
, EQ_EXPR
);
6931 return omit_one_operand (type
,
6932 convert (type
, integer_one_node
),
6936 TREE_SET_CODE (t
, NE_EXPR
);
6942 else if (TREE_INT_CST_HIGH (arg1
) == (min
? -1 : 0)
6943 && TREE_INT_CST_LOW (arg1
) == min
+ 1)
6948 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6949 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6953 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6954 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6960 else if (TREE_INT_CST_HIGH (arg1
) == 0
6961 && TREE_INT_CST_LOW (arg1
) == signed_max
6962 && TREE_UNSIGNED (TREE_TYPE (arg1
))
6963 /* signed_type does not work on pointer types. */
6964 && INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
6966 /* The following case also applies to X < signed_max+1
6967 and X >= signed_max+1 because previous transformations. */
6968 if (code
== LE_EXPR
|| code
== GT_EXPR
)
6971 st0
= (*lang_hooks
.types
.signed_type
) (TREE_TYPE (arg0
));
6972 st1
= (*lang_hooks
.types
.signed_type
) (TREE_TYPE (arg1
));
6974 (build (code
== LE_EXPR
? GE_EXPR
: LT_EXPR
,
6975 type
, convert (st0
, arg0
),
6976 convert (st1
, integer_zero_node
)));
6982 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6983 a MINUS_EXPR of a constant, we can convert it into a comparison with
6984 a revised constant as long as no overflow occurs. */
6985 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6986 && TREE_CODE (arg1
) == INTEGER_CST
6987 && (TREE_CODE (arg0
) == PLUS_EXPR
6988 || TREE_CODE (arg0
) == MINUS_EXPR
)
6989 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
6990 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
6991 ? MINUS_EXPR
: PLUS_EXPR
,
6992 arg1
, TREE_OPERAND (arg0
, 1), 0))
6993 && ! TREE_CONSTANT_OVERFLOW (tem
))
6994 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6996 /* Similarly for a NEGATE_EXPR. */
6997 else if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6998 && TREE_CODE (arg0
) == NEGATE_EXPR
6999 && TREE_CODE (arg1
) == INTEGER_CST
7000 && 0 != (tem
= negate_expr (arg1
))
7001 && TREE_CODE (tem
) == INTEGER_CST
7002 && ! TREE_CONSTANT_OVERFLOW (tem
))
7003 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
7005 /* If we have X - Y == 0, we can convert that to X == Y and similarly
7006 for !=. Don't do this for ordered comparisons due to overflow. */
7007 else if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
7008 && integer_zerop (arg1
) && TREE_CODE (arg0
) == MINUS_EXPR
)
7009 return fold (build (code
, type
,
7010 TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg0
, 1)));
7012 /* If we are widening one operand of an integer comparison,
7013 see if the other operand is similarly being widened. Perhaps we
7014 can do the comparison in the narrower type. */
7015 else if (TREE_CODE (TREE_TYPE (arg0
)) == INTEGER_TYPE
7016 && TREE_CODE (arg0
) == NOP_EXPR
7017 && (tem
= get_unwidened (arg0
, NULL_TREE
)) != arg0
7018 && (t1
= get_unwidened (arg1
, TREE_TYPE (tem
))) != 0
7019 && (TREE_TYPE (t1
) == TREE_TYPE (tem
)
7020 || (TREE_CODE (t1
) == INTEGER_CST
7021 && int_fits_type_p (t1
, TREE_TYPE (tem
)))))
7022 return fold (build (code
, type
, tem
, convert (TREE_TYPE (tem
), t1
)));
7024 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
7025 constant, we can simplify it. */
7026 else if (TREE_CODE (arg1
) == INTEGER_CST
7027 && (TREE_CODE (arg0
) == MIN_EXPR
7028 || TREE_CODE (arg0
) == MAX_EXPR
)
7029 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
7030 return optimize_minmax_comparison (t
);
7032 /* If we are comparing an ABS_EXPR with a constant, we can
7033 convert all the cases into explicit comparisons, but they may
7034 well not be faster than doing the ABS and one comparison.
7035 But ABS (X) <= C is a range comparison, which becomes a subtraction
7036 and a comparison, and is probably faster. */
7037 else if (code
== LE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
7038 && TREE_CODE (arg0
) == ABS_EXPR
7039 && ! TREE_SIDE_EFFECTS (arg0
)
7040 && (0 != (tem
= negate_expr (arg1
)))
7041 && TREE_CODE (tem
) == INTEGER_CST
7042 && ! TREE_CONSTANT_OVERFLOW (tem
))
7043 return fold (build (TRUTH_ANDIF_EXPR
, type
,
7044 build (GE_EXPR
, type
, TREE_OPERAND (arg0
, 0), tem
),
7045 build (LE_EXPR
, type
,
7046 TREE_OPERAND (arg0
, 0), arg1
)));
7048 /* If this is an EQ or NE comparison with zero and ARG0 is
7049 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
7050 two operations, but the latter can be done in one less insn
7051 on machines that have only two-operand insns or on which a
7052 constant cannot be the first operand. */
7053 if (integer_zerop (arg1
) && (code
== EQ_EXPR
|| code
== NE_EXPR
)
7054 && TREE_CODE (arg0
) == BIT_AND_EXPR
)
7056 if (TREE_CODE (TREE_OPERAND (arg0
, 0)) == LSHIFT_EXPR
7057 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0)))
7059 fold (build (code
, type
,
7060 build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
7062 TREE_TYPE (TREE_OPERAND (arg0
, 0)),
7063 TREE_OPERAND (arg0
, 1),
7064 TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1)),
7065 convert (TREE_TYPE (arg0
),
7068 else if (TREE_CODE (TREE_OPERAND (arg0
, 1)) == LSHIFT_EXPR
7069 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 1), 0)))
7071 fold (build (code
, type
,
7072 build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
7074 TREE_TYPE (TREE_OPERAND (arg0
, 1)),
7075 TREE_OPERAND (arg0
, 0),
7076 TREE_OPERAND (TREE_OPERAND (arg0
, 1), 1)),
7077 convert (TREE_TYPE (arg0
),
7082 /* If this is an NE or EQ comparison of zero against the result of a
7083 signed MOD operation whose second operand is a power of 2, make
7084 the MOD operation unsigned since it is simpler and equivalent. */
7085 if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
7086 && integer_zerop (arg1
)
7087 && ! TREE_UNSIGNED (TREE_TYPE (arg0
))
7088 && (TREE_CODE (arg0
) == TRUNC_MOD_EXPR
7089 || TREE_CODE (arg0
) == CEIL_MOD_EXPR
7090 || TREE_CODE (arg0
) == FLOOR_MOD_EXPR
7091 || TREE_CODE (arg0
) == ROUND_MOD_EXPR
)
7092 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
7094 tree newtype
= (*lang_hooks
.types
.unsigned_type
) (TREE_TYPE (arg0
));
7095 tree newmod
= build (TREE_CODE (arg0
), newtype
,
7096 convert (newtype
, TREE_OPERAND (arg0
, 0)),
7097 convert (newtype
, TREE_OPERAND (arg0
, 1)));
7099 return build (code
, type
, newmod
, convert (newtype
, arg1
));
7102 /* If this is an NE comparison of zero with an AND of one, remove the
7103 comparison since the AND will give the correct value. */
7104 if (code
== NE_EXPR
&& integer_zerop (arg1
)
7105 && TREE_CODE (arg0
) == BIT_AND_EXPR
7106 && integer_onep (TREE_OPERAND (arg0
, 1)))
7107 return convert (type
, arg0
);
7109 /* If we have (A & C) == C where C is a power of 2, convert this into
7110 (A & C) != 0. Similarly for NE_EXPR. */
7111 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7112 && TREE_CODE (arg0
) == BIT_AND_EXPR
7113 && integer_pow2p (TREE_OPERAND (arg0
, 1))
7114 && operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
7115 return fold (build (code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
, type
,
7116 arg0
, integer_zero_node
));
7118 /* If we have (A & C) != 0 where C is the sign bit of A, convert
7119 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
7120 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7121 && TREE_CODE (arg0
) == BIT_AND_EXPR
7122 && integer_zerop (arg1
))
7124 tree arg00
= sign_bit_p (TREE_OPERAND (arg0
, 0),
7125 TREE_OPERAND (arg0
, 1));
7126 if (arg00
!= NULL_TREE
)
7128 tree stype
= (*lang_hooks
.types
.signed_type
) (TREE_TYPE (arg00
));
7129 return fold (build (code
== EQ_EXPR
? GE_EXPR
: LT_EXPR
, type
,
7130 convert (stype
, arg00
),
7131 convert (stype
, integer_zero_node
)));
7135 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
7136 and similarly for >= into !=. */
7137 if ((code
== LT_EXPR
|| code
== GE_EXPR
)
7138 && TREE_UNSIGNED (TREE_TYPE (arg0
))
7139 && TREE_CODE (arg1
) == LSHIFT_EXPR
7140 && integer_onep (TREE_OPERAND (arg1
, 0)))
7141 return build (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
7142 build (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
7143 TREE_OPERAND (arg1
, 1)),
7144 convert (TREE_TYPE (arg0
), integer_zero_node
));
7146 else if ((code
== LT_EXPR
|| code
== GE_EXPR
)
7147 && TREE_UNSIGNED (TREE_TYPE (arg0
))
7148 && (TREE_CODE (arg1
) == NOP_EXPR
7149 || TREE_CODE (arg1
) == CONVERT_EXPR
)
7150 && TREE_CODE (TREE_OPERAND (arg1
, 0)) == LSHIFT_EXPR
7151 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0)))
7153 build (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
7154 convert (TREE_TYPE (arg0
),
7155 build (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
7156 TREE_OPERAND (TREE_OPERAND (arg1
, 0), 1))),
7157 convert (TREE_TYPE (arg0
), integer_zero_node
));
7159 /* Simplify comparison of something with itself. (For IEEE
7160 floating-point, we can only do some of these simplifications.) */
7161 if (operand_equal_p (arg0
, arg1
, 0))
7168 if (! FLOAT_TYPE_P (TREE_TYPE (arg0
))
7169 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
))))
7170 return constant_boolean_node (1, type
);
7172 TREE_SET_CODE (t
, code
);
7176 /* For NE, we can only do this simplification if integer
7177 or we don't honor IEEE floating point NaNs. */
7178 if (FLOAT_TYPE_P (TREE_TYPE (arg0
))
7179 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
))))
7181 /* ... fall through ... */
7184 return constant_boolean_node (0, type
);
7190 /* If we are comparing an expression that just has comparisons
7191 of two integer values, arithmetic expressions of those comparisons,
7192 and constants, we can simplify it. There are only three cases
7193 to check: the two values can either be equal, the first can be
7194 greater, or the second can be greater. Fold the expression for
7195 those three values. Since each value must be 0 or 1, we have
7196 eight possibilities, each of which corresponds to the constant 0
7197 or 1 or one of the six possible comparisons.
7199 This handles common cases like (a > b) == 0 but also handles
7200 expressions like ((x > y) - (y > x)) > 0, which supposedly
7201 occur in macroized code. */
7203 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) != INTEGER_CST
)
7205 tree cval1
= 0, cval2
= 0;
7208 if (twoval_comparison_p (arg0
, &cval1
, &cval2
, &save_p
)
7209 /* Don't handle degenerate cases here; they should already
7210 have been handled anyway. */
7211 && cval1
!= 0 && cval2
!= 0
7212 && ! (TREE_CONSTANT (cval1
) && TREE_CONSTANT (cval2
))
7213 && TREE_TYPE (cval1
) == TREE_TYPE (cval2
)
7214 && INTEGRAL_TYPE_P (TREE_TYPE (cval1
))
7215 && TYPE_MAX_VALUE (TREE_TYPE (cval1
))
7216 && TYPE_MAX_VALUE (TREE_TYPE (cval2
))
7217 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1
)),
7218 TYPE_MAX_VALUE (TREE_TYPE (cval2
)), 0))
7220 tree maxval
= TYPE_MAX_VALUE (TREE_TYPE (cval1
));
7221 tree minval
= TYPE_MIN_VALUE (TREE_TYPE (cval1
));
7223 /* We can't just pass T to eval_subst in case cval1 or cval2
7224 was the same as ARG1. */
7227 = fold (build (code
, type
,
7228 eval_subst (arg0
, cval1
, maxval
, cval2
, minval
),
7231 = fold (build (code
, type
,
7232 eval_subst (arg0
, cval1
, maxval
, cval2
, maxval
),
7235 = fold (build (code
, type
,
7236 eval_subst (arg0
, cval1
, minval
, cval2
, maxval
),
7239 /* All three of these results should be 0 or 1. Confirm they
7240 are. Then use those values to select the proper code
7243 if ((integer_zerop (high_result
)
7244 || integer_onep (high_result
))
7245 && (integer_zerop (equal_result
)
7246 || integer_onep (equal_result
))
7247 && (integer_zerop (low_result
)
7248 || integer_onep (low_result
)))
7250 /* Make a 3-bit mask with the high-order bit being the
7251 value for `>', the next for '=', and the low for '<'. */
7252 switch ((integer_onep (high_result
) * 4)
7253 + (integer_onep (equal_result
) * 2)
7254 + integer_onep (low_result
))
7258 return omit_one_operand (type
, integer_zero_node
, arg0
);
7279 return omit_one_operand (type
, integer_one_node
, arg0
);
7282 t
= build (code
, type
, cval1
, cval2
);
7284 return save_expr (t
);
7291 /* If this is a comparison of a field, we may be able to simplify it. */
7292 if (((TREE_CODE (arg0
) == COMPONENT_REF
7293 && (*lang_hooks
.can_use_bit_fields_p
) ())
7294 || TREE_CODE (arg0
) == BIT_FIELD_REF
)
7295 && (code
== EQ_EXPR
|| code
== NE_EXPR
)
7296 /* Handle the constant case even without -O
7297 to make sure the warnings are given. */
7298 && (optimize
|| TREE_CODE (arg1
) == INTEGER_CST
))
7300 t1
= optimize_bit_field_compare (code
, type
, arg0
, arg1
);
7304 /* If this is a comparison of complex values and either or both sides
7305 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
7306 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
7307 This may prevent needless evaluations. */
7308 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7309 && TREE_CODE (TREE_TYPE (arg0
)) == COMPLEX_TYPE
7310 && (TREE_CODE (arg0
) == COMPLEX_EXPR
7311 || TREE_CODE (arg1
) == COMPLEX_EXPR
7312 || TREE_CODE (arg0
) == COMPLEX_CST
7313 || TREE_CODE (arg1
) == COMPLEX_CST
))
7315 tree subtype
= TREE_TYPE (TREE_TYPE (arg0
));
7316 tree real0
, imag0
, real1
, imag1
;
7318 arg0
= save_expr (arg0
);
7319 arg1
= save_expr (arg1
);
7320 real0
= fold (build1 (REALPART_EXPR
, subtype
, arg0
));
7321 imag0
= fold (build1 (IMAGPART_EXPR
, subtype
, arg0
));
7322 real1
= fold (build1 (REALPART_EXPR
, subtype
, arg1
));
7323 imag1
= fold (build1 (IMAGPART_EXPR
, subtype
, arg1
));
7325 return fold (build ((code
== EQ_EXPR
? TRUTH_ANDIF_EXPR
7328 fold (build (code
, type
, real0
, real1
)),
7329 fold (build (code
, type
, imag0
, imag1
))));
7332 /* Optimize comparisons of strlen vs zero to a compare of the
7333 first character of the string vs zero. To wit,
7334 strlen(ptr) == 0 => *ptr == 0
7335 strlen(ptr) != 0 => *ptr != 0
7336 Other cases should reduce to one of these two (or a constant)
7337 due to the return value of strlen being unsigned. */
7338 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7339 && integer_zerop (arg1
)
7340 && TREE_CODE (arg0
) == CALL_EXPR
7341 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == ADDR_EXPR
)
7343 tree fndecl
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
7346 if (TREE_CODE (fndecl
) == FUNCTION_DECL
7347 && DECL_BUILT_IN (fndecl
)
7348 && DECL_BUILT_IN_CLASS (fndecl
) != BUILT_IN_MD
7349 && DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STRLEN
7350 && (arglist
= TREE_OPERAND (arg0
, 1))
7351 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist
))) == POINTER_TYPE
7352 && ! TREE_CHAIN (arglist
))
7353 return fold (build (code
, type
,
7354 build1 (INDIRECT_REF
, char_type_node
,
7355 TREE_VALUE(arglist
)),
7356 integer_zero_node
));
7359 /* From here on, the only cases we handle are when the result is
7360 known to be a constant.
7362 To compute GT, swap the arguments and do LT.
7363 To compute GE, do LT and invert the result.
7364 To compute LE, swap the arguments, do LT and invert the result.
7365 To compute NE, do EQ and invert the result.
7367 Therefore, the code below must handle only EQ and LT. */
7369 if (code
== LE_EXPR
|| code
== GT_EXPR
)
7371 tem
= arg0
, arg0
= arg1
, arg1
= tem
;
7372 code
= swap_tree_comparison (code
);
7375 /* Note that it is safe to invert for real values here because we
7376 will check below in the one case that it matters. */
7380 if (code
== NE_EXPR
|| code
== GE_EXPR
)
7383 code
= invert_tree_comparison (code
);
7386 /* Compute a result for LT or EQ if args permit;
7387 otherwise return T. */
7388 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
7390 if (code
== EQ_EXPR
)
7391 t1
= build_int_2 (tree_int_cst_equal (arg0
, arg1
), 0);
7393 t1
= build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0
))
7394 ? INT_CST_LT_UNSIGNED (arg0
, arg1
)
7395 : INT_CST_LT (arg0
, arg1
)),
7399 #if 0 /* This is no longer useful, but breaks some real code. */
7400 /* Assume a nonexplicit constant cannot equal an explicit one,
7401 since such code would be undefined anyway.
7402 Exception: on sysvr4, using #pragma weak,
7403 a label can come out as 0. */
7404 else if (TREE_CODE (arg1
) == INTEGER_CST
7405 && !integer_zerop (arg1
)
7406 && TREE_CONSTANT (arg0
)
7407 && TREE_CODE (arg0
) == ADDR_EXPR
7409 t1
= build_int_2 (0, 0);
7411 /* Two real constants can be compared explicitly. */
7412 else if (TREE_CODE (arg0
) == REAL_CST
&& TREE_CODE (arg1
) == REAL_CST
)
7414 /* If either operand is a NaN, the result is false with two
7415 exceptions: First, an NE_EXPR is true on NaNs, but that case
7416 is already handled correctly since we will be inverting the
7417 result for NE_EXPR. Second, if we had inverted a LE_EXPR
7418 or a GE_EXPR into a LT_EXPR, we must return true so that it
7419 will be inverted into false. */
7421 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0
))
7422 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
7423 t1
= build_int_2 (invert
&& code
== LT_EXPR
, 0);
7425 else if (code
== EQ_EXPR
)
7426 t1
= build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0
),
7427 TREE_REAL_CST (arg1
)),
7430 t1
= build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0
),
7431 TREE_REAL_CST (arg1
)),
7435 if (t1
== NULL_TREE
)
7439 TREE_INT_CST_LOW (t1
) ^= 1;
7441 TREE_TYPE (t1
) = type
;
7442 if (TREE_CODE (type
) == BOOLEAN_TYPE
)
7443 return (*lang_hooks
.truthvalue_conversion
) (t1
);
7447 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
7448 so all simple results must be passed through pedantic_non_lvalue. */
7449 if (TREE_CODE (arg0
) == INTEGER_CST
)
7450 return pedantic_non_lvalue
7451 (TREE_OPERAND (t
, (integer_zerop (arg0
) ? 2 : 1)));
7452 else if (operand_equal_p (arg1
, TREE_OPERAND (expr
, 2), 0))
7453 return pedantic_omit_one_operand (type
, arg1
, arg0
);
7455 /* If the second operand is zero, invert the comparison and swap
7456 the second and third operands. Likewise if the second operand
7457 is constant and the third is not or if the third operand is
7458 equivalent to the first operand of the comparison. */
7460 if (integer_zerop (arg1
)
7461 || (TREE_CONSTANT (arg1
) && ! TREE_CONSTANT (TREE_OPERAND (t
, 2)))
7462 || (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
7463 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
7464 TREE_OPERAND (t
, 2),
7465 TREE_OPERAND (arg0
, 1))))
7467 /* See if this can be inverted. If it can't, possibly because
7468 it was a floating-point inequality comparison, don't do
7470 tem
= invert_truthvalue (arg0
);
7472 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
7474 t
= build (code
, type
, tem
,
7475 TREE_OPERAND (t
, 2), TREE_OPERAND (t
, 1));
7477 /* arg1 should be the first argument of the new T. */
7478 arg1
= TREE_OPERAND (t
, 1);
7483 /* If we have A op B ? A : C, we may be able to convert this to a
7484 simpler expression, depending on the operation and the values
7485 of B and C. Signed zeros prevent all of these transformations,
7486 for reasons given above each one. */
7488 if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
7489 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
7490 arg1
, TREE_OPERAND (arg0
, 1))
7491 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1
))))
7493 tree arg2
= TREE_OPERAND (t
, 2);
7494 enum tree_code comp_code
= TREE_CODE (arg0
);
7498 /* If we have A op 0 ? A : -A, consider applying the following
7501 A == 0? A : -A same as -A
7502 A != 0? A : -A same as A
7503 A >= 0? A : -A same as abs (A)
7504 A > 0? A : -A same as abs (A)
7505 A <= 0? A : -A same as -abs (A)
7506 A < 0? A : -A same as -abs (A)
7508 None of these transformations work for modes with signed
7509 zeros. If A is +/-0, the first two transformations will
7510 change the sign of the result (from +0 to -0, or vice
7511 versa). The last four will fix the sign of the result,
7512 even though the original expressions could be positive or
7513 negative, depending on the sign of A.
7515 Note that all these transformations are correct if A is
7516 NaN, since the two alternatives (A and -A) are also NaNs. */
7517 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0
, 1)))
7518 ? real_zerop (TREE_OPERAND (arg0
, 1))
7519 : integer_zerop (TREE_OPERAND (arg0
, 1)))
7520 && TREE_CODE (arg2
) == NEGATE_EXPR
7521 && operand_equal_p (TREE_OPERAND (arg2
, 0), arg1
, 0))
7529 (convert (TREE_TYPE (TREE_OPERAND (t
, 1)),
7532 return pedantic_non_lvalue (convert (type
, arg1
));
7535 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
7536 arg1
= convert ((*lang_hooks
.types
.signed_type
)
7537 (TREE_TYPE (arg1
)), arg1
);
7538 return pedantic_non_lvalue
7539 (convert (type
, fold (build1 (ABS_EXPR
,
7540 TREE_TYPE (arg1
), arg1
))));
7543 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
7544 arg1
= convert ((lang_hooks
.types
.signed_type
)
7545 (TREE_TYPE (arg1
)), arg1
);
7546 return pedantic_non_lvalue
7547 (negate_expr (convert (type
,
7548 fold (build1 (ABS_EXPR
,
7555 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
7556 A == 0 ? A : 0 is always 0 unless A is -0. Note that
7557 both transformations are correct when A is NaN: A != 0
7558 is then true, and A == 0 is false. */
7560 if (integer_zerop (TREE_OPERAND (arg0
, 1)) && integer_zerop (arg2
))
7562 if (comp_code
== NE_EXPR
)
7563 return pedantic_non_lvalue (convert (type
, arg1
));
7564 else if (comp_code
== EQ_EXPR
)
7565 return pedantic_non_lvalue (convert (type
, integer_zero_node
));
7568 /* Try some transformations of A op B ? A : B.
7570 A == B? A : B same as B
7571 A != B? A : B same as A
7572 A >= B? A : B same as max (A, B)
7573 A > B? A : B same as max (B, A)
7574 A <= B? A : B same as min (A, B)
7575 A < B? A : B same as min (B, A)
7577 As above, these transformations don't work in the presence
7578 of signed zeros. For example, if A and B are zeros of
7579 opposite sign, the first two transformations will change
7580 the sign of the result. In the last four, the original
7581 expressions give different results for (A=+0, B=-0) and
7582 (A=-0, B=+0), but the transformed expressions do not.
7584 The first two transformations are correct if either A or B
7585 is a NaN. In the first transformation, the condition will
7586 be false, and B will indeed be chosen. In the case of the
7587 second transformation, the condition A != B will be true,
7588 and A will be chosen.
7590 The conversions to max() and min() are not correct if B is
7591 a number and A is not. The conditions in the original
7592 expressions will be false, so all four give B. The min()
7593 and max() versions would give a NaN instead. */
7594 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 1),
7595 arg2
, TREE_OPERAND (arg0
, 0)))
7597 tree comp_op0
= TREE_OPERAND (arg0
, 0);
7598 tree comp_op1
= TREE_OPERAND (arg0
, 1);
7599 tree comp_type
= TREE_TYPE (comp_op0
);
7601 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
7602 if (TYPE_MAIN_VARIANT (comp_type
) == TYPE_MAIN_VARIANT (type
))
7612 return pedantic_non_lvalue (convert (type
, arg2
));
7614 return pedantic_non_lvalue (convert (type
, arg1
));
7617 /* In C++ a ?: expression can be an lvalue, so put the
7618 operand which will be used if they are equal first
7619 so that we can convert this back to the
7620 corresponding COND_EXPR. */
7621 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
7622 return pedantic_non_lvalue
7623 (convert (type
, fold (build (MIN_EXPR
, comp_type
,
7624 (comp_code
== LE_EXPR
7625 ? comp_op0
: comp_op1
),
7626 (comp_code
== LE_EXPR
7627 ? comp_op1
: comp_op0
)))));
7631 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
7632 return pedantic_non_lvalue
7633 (convert (type
, fold (build (MAX_EXPR
, comp_type
,
7634 (comp_code
== GE_EXPR
7635 ? comp_op0
: comp_op1
),
7636 (comp_code
== GE_EXPR
7637 ? comp_op1
: comp_op0
)))));
7644 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
7645 we might still be able to simplify this. For example,
7646 if C1 is one less or one more than C2, this might have started
7647 out as a MIN or MAX and been transformed by this function.
7648 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
7650 if (INTEGRAL_TYPE_P (type
)
7651 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
7652 && TREE_CODE (arg2
) == INTEGER_CST
)
7656 /* We can replace A with C1 in this case. */
7657 arg1
= convert (type
, TREE_OPERAND (arg0
, 1));
7658 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
,
7659 TREE_OPERAND (t
, 2));
7663 /* If C1 is C2 + 1, this is min(A, C2). */
7664 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
7665 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7666 const_binop (PLUS_EXPR
, arg2
,
7667 integer_one_node
, 0), 1))
7668 return pedantic_non_lvalue
7669 (fold (build (MIN_EXPR
, type
, arg1
, arg2
)));
7673 /* If C1 is C2 - 1, this is min(A, C2). */
7674 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
7675 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7676 const_binop (MINUS_EXPR
, arg2
,
7677 integer_one_node
, 0), 1))
7678 return pedantic_non_lvalue
7679 (fold (build (MIN_EXPR
, type
, arg1
, arg2
)));
7683 /* If C1 is C2 - 1, this is max(A, C2). */
7684 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
7685 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7686 const_binop (MINUS_EXPR
, arg2
,
7687 integer_one_node
, 0), 1))
7688 return pedantic_non_lvalue
7689 (fold (build (MAX_EXPR
, type
, arg1
, arg2
)));
7693 /* If C1 is C2 + 1, this is max(A, C2). */
7694 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
7695 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7696 const_binop (PLUS_EXPR
, arg2
,
7697 integer_one_node
, 0), 1))
7698 return pedantic_non_lvalue
7699 (fold (build (MAX_EXPR
, type
, arg1
, arg2
)));
7708 /* If the second operand is simpler than the third, swap them
7709 since that produces better jump optimization results. */
7710 if ((TREE_CONSTANT (arg1
) || DECL_P (arg1
)
7711 || TREE_CODE (arg1
) == SAVE_EXPR
)
7712 && ! (TREE_CONSTANT (TREE_OPERAND (t
, 2))
7713 || DECL_P (TREE_OPERAND (t
, 2))
7714 || TREE_CODE (TREE_OPERAND (t
, 2)) == SAVE_EXPR
))
7716 /* See if this can be inverted. If it can't, possibly because
7717 it was a floating-point inequality comparison, don't do
7719 tem
= invert_truthvalue (arg0
);
7721 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
7723 t
= build (code
, type
, tem
,
7724 TREE_OPERAND (t
, 2), TREE_OPERAND (t
, 1));
7726 /* arg1 should be the first argument of the new T. */
7727 arg1
= TREE_OPERAND (t
, 1);
7732 /* Convert A ? 1 : 0 to simply A. */
7733 if (integer_onep (TREE_OPERAND (t
, 1))
7734 && integer_zerop (TREE_OPERAND (t
, 2))
7735 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7736 call to fold will try to move the conversion inside
7737 a COND, which will recurse. In that case, the COND_EXPR
7738 is probably the best choice, so leave it alone. */
7739 && type
== TREE_TYPE (arg0
))
7740 return pedantic_non_lvalue (arg0
);
7742 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
7743 over COND_EXPR in cases such as floating point comparisons. */
7744 if (integer_zerop (TREE_OPERAND (t
, 1))
7745 && integer_onep (TREE_OPERAND (t
, 2))
7746 && truth_value_p (TREE_CODE (arg0
)))
7747 return pedantic_non_lvalue (convert (type
,
7748 invert_truthvalue (arg0
)));
7750 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7751 operation is simply A & 2. */
7753 if (integer_zerop (TREE_OPERAND (t
, 2))
7754 && TREE_CODE (arg0
) == NE_EXPR
7755 && integer_zerop (TREE_OPERAND (arg0
, 1))
7756 && integer_pow2p (arg1
)
7757 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == BIT_AND_EXPR
7758 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1),
7760 return pedantic_non_lvalue (convert (type
, TREE_OPERAND (arg0
, 0)));
7762 /* Convert A ? B : 0 into A && B if A and B are truth values. */
7763 if (integer_zerop (TREE_OPERAND (t
, 2))
7764 && truth_value_p (TREE_CODE (arg0
))
7765 && truth_value_p (TREE_CODE (arg1
)))
7766 return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR
, type
,
7769 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
7770 if (integer_onep (TREE_OPERAND (t
, 2))
7771 && truth_value_p (TREE_CODE (arg0
))
7772 && truth_value_p (TREE_CODE (arg1
)))
7774 /* Only perform transformation if ARG0 is easily inverted. */
7775 tem
= invert_truthvalue (arg0
);
7776 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
7777 return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR
, type
,
7784 /* When pedantic, a compound expression can be neither an lvalue
7785 nor an integer constant expression. */
7786 if (TREE_SIDE_EFFECTS (arg0
) || pedantic
)
7788 /* Don't let (0, 0) be null pointer constant. */
7789 if (integer_zerop (arg1
))
7790 return build1 (NOP_EXPR
, type
, arg1
);
7791 return convert (type
, arg1
);
7795 return build_complex (type
, arg0
, arg1
);
7799 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
7801 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
7802 return omit_one_operand (type
, TREE_OPERAND (arg0
, 0),
7803 TREE_OPERAND (arg0
, 1));
7804 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
7805 return TREE_REALPART (arg0
);
7806 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
7807 return fold (build (TREE_CODE (arg0
), type
,
7808 fold (build1 (REALPART_EXPR
, type
,
7809 TREE_OPERAND (arg0
, 0))),
7810 fold (build1 (REALPART_EXPR
,
7811 type
, TREE_OPERAND (arg0
, 1)))));
7815 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
7816 return convert (type
, integer_zero_node
);
7817 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
7818 return omit_one_operand (type
, TREE_OPERAND (arg0
, 1),
7819 TREE_OPERAND (arg0
, 0));
7820 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
7821 return TREE_IMAGPART (arg0
);
7822 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
7823 return fold (build (TREE_CODE (arg0
), type
,
7824 fold (build1 (IMAGPART_EXPR
, type
,
7825 TREE_OPERAND (arg0
, 0))),
7826 fold (build1 (IMAGPART_EXPR
, type
,
7827 TREE_OPERAND (arg0
, 1)))));
7830 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7832 case CLEANUP_POINT_EXPR
:
7833 if (! has_cleanups (arg0
))
7834 return TREE_OPERAND (t
, 0);
7837 enum tree_code code0
= TREE_CODE (arg0
);
7838 int kind0
= TREE_CODE_CLASS (code0
);
7839 tree arg00
= TREE_OPERAND (arg0
, 0);
7842 if (kind0
== '1' || code0
== TRUTH_NOT_EXPR
)
7843 return fold (build1 (code0
, type
,
7844 fold (build1 (CLEANUP_POINT_EXPR
,
7845 TREE_TYPE (arg00
), arg00
))));
7847 if (kind0
== '<' || kind0
== '2'
7848 || code0
== TRUTH_ANDIF_EXPR
|| code0
== TRUTH_ORIF_EXPR
7849 || code0
== TRUTH_AND_EXPR
|| code0
== TRUTH_OR_EXPR
7850 || code0
== TRUTH_XOR_EXPR
)
7852 arg01
= TREE_OPERAND (arg0
, 1);
7854 if (TREE_CONSTANT (arg00
)
7855 || ((code0
== TRUTH_ANDIF_EXPR
|| code0
== TRUTH_ORIF_EXPR
)
7856 && ! has_cleanups (arg00
)))
7857 return fold (build (code0
, type
, arg00
,
7858 fold (build1 (CLEANUP_POINT_EXPR
,
7859 TREE_TYPE (arg01
), arg01
))));
7861 if (TREE_CONSTANT (arg01
))
7862 return fold (build (code0
, type
,
7863 fold (build1 (CLEANUP_POINT_EXPR
,
7864 TREE_TYPE (arg00
), arg00
)),
7872 /* Check for a built-in function. */
7873 if (TREE_CODE (TREE_OPERAND (expr
, 0)) == ADDR_EXPR
7874 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr
, 0), 0))
7876 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr
, 0), 0)))
7878 tree tmp
= fold_builtin (expr
);
7886 } /* switch (code) */
7889 /* Determine if first argument is a multiple of second argument. Return 0 if
7890 it is not, or we cannot easily determined it to be.
7892 An example of the sort of thing we care about (at this point; this routine
7893 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7894 fold cases do now) is discovering that
7896 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7902 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7904 This code also handles discovering that
7906 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7908 is a multiple of 8 so we don't have to worry about dealing with a
7911 Note that we *look* inside a SAVE_EXPR only to determine how it was
7912 calculated; it is not safe for fold to do much of anything else with the
7913 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7914 at run time. For example, the latter example above *cannot* be implemented
7915 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7916 evaluation time of the original SAVE_EXPR is not necessarily the same at
7917 the time the new expression is evaluated. The only optimization of this
7918 sort that would be valid is changing
7920 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7924 SAVE_EXPR (I) * SAVE_EXPR (J)
7926 (where the same SAVE_EXPR (J) is used in the original and the
7927 transformed version). */
7930 multiple_of_p (type
, top
, bottom
)
7935 if (operand_equal_p (top
, bottom
, 0))
7938 if (TREE_CODE (type
) != INTEGER_TYPE
)
7941 switch (TREE_CODE (top
))
7944 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
7945 || multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
7949 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
7950 && multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
7953 if (TREE_CODE (TREE_OPERAND (top
, 1)) == INTEGER_CST
)
7957 op1
= TREE_OPERAND (top
, 1);
7958 /* const_binop may not detect overflow correctly,
7959 so check for it explicitly here. */
7960 if (TYPE_PRECISION (TREE_TYPE (size_one_node
))
7961 > TREE_INT_CST_LOW (op1
)
7962 && TREE_INT_CST_HIGH (op1
) == 0
7963 && 0 != (t1
= convert (type
,
7964 const_binop (LSHIFT_EXPR
, size_one_node
,
7966 && ! TREE_OVERFLOW (t1
))
7967 return multiple_of_p (type
, t1
, bottom
);
7972 /* Can't handle conversions from non-integral or wider integral type. */
7973 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top
, 0))) != INTEGER_TYPE
)
7974 || (TYPE_PRECISION (type
)
7975 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top
, 0)))))
7978 /* .. fall through ... */
7981 return multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
);
7984 if (TREE_CODE (bottom
) != INTEGER_CST
7985 || (TREE_UNSIGNED (type
)
7986 && (tree_int_cst_sgn (top
) < 0
7987 || tree_int_cst_sgn (bottom
) < 0)))
7989 return integer_zerop (const_binop (TRUNC_MOD_EXPR
,
7997 /* Return true if `t' is known to be non-negative. */
8000 tree_expr_nonnegative_p (t
)
8003 switch (TREE_CODE (t
))
8013 /* These are undefined at zero. This is true even if
8014 C[LT]Z_DEFINED_VALUE_AT_ZERO is set, since what we're
8015 computing here is a user-visible property. */
8019 return tree_int_cst_sgn (t
) >= 0;
8022 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t
));
8025 if (FLOAT_TYPE_P (TREE_TYPE (t
)))
8026 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8027 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8029 /* zero_extend(x) + zero_extend(y) is non-negative is x and y are
8030 both unsigned and at least 2 bits shorter than the result. */
8031 if (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
8032 && TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
8033 && TREE_CODE (TREE_OPERAND (t
, 1)) == NOP_EXPR
)
8035 tree inner1
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
8036 tree inner2
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0));
8037 if (TREE_CODE (inner1
) == INTEGER_TYPE
&& TREE_UNSIGNED (inner1
)
8038 && TREE_CODE (inner2
) == INTEGER_TYPE
&& TREE_UNSIGNED (inner2
))
8040 unsigned int prec
= MAX (TYPE_PRECISION (inner1
),
8041 TYPE_PRECISION (inner2
)) + 1;
8042 return prec
< TYPE_PRECISION (TREE_TYPE (t
));
8048 if (FLOAT_TYPE_P (TREE_TYPE (t
)))
8050 /* x * x for floating point x is always non-negative. */
8051 if (operand_equal_p (TREE_OPERAND (t
, 0), TREE_OPERAND (t
, 1), 0))
8053 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8054 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8057 /* zero_extend(x) * zero_extend(y) is non-negative is x and y are
8058 both unsigned and their total bits is shorter than the result. */
8059 if (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
8060 && TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
8061 && TREE_CODE (TREE_OPERAND (t
, 1)) == NOP_EXPR
)
8063 tree inner1
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
8064 tree inner2
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0));
8065 if (TREE_CODE (inner1
) == INTEGER_TYPE
&& TREE_UNSIGNED (inner1
)
8066 && TREE_CODE (inner2
) == INTEGER_TYPE
&& TREE_UNSIGNED (inner2
))
8067 return TYPE_PRECISION (inner1
) + TYPE_PRECISION (inner2
)
8068 < TYPE_PRECISION (TREE_TYPE (t
));
8072 case TRUNC_DIV_EXPR
:
8074 case FLOOR_DIV_EXPR
:
8075 case ROUND_DIV_EXPR
:
8076 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8077 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8079 case TRUNC_MOD_EXPR
:
8081 case FLOOR_MOD_EXPR
:
8082 case ROUND_MOD_EXPR
:
8083 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
8086 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8087 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8091 tree inner_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
8092 tree outer_type
= TREE_TYPE (t
);
8094 if (TREE_CODE (outer_type
) == REAL_TYPE
)
8096 if (TREE_CODE (inner_type
) == REAL_TYPE
)
8097 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
8098 if (TREE_CODE (inner_type
) == INTEGER_TYPE
)
8100 if (TREE_UNSIGNED (inner_type
))
8102 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
8105 else if (TREE_CODE (outer_type
) == INTEGER_TYPE
)
8107 if (TREE_CODE (inner_type
) == REAL_TYPE
)
8108 return tree_expr_nonnegative_p (TREE_OPERAND (t
,0));
8109 if (TREE_CODE (inner_type
) == INTEGER_TYPE
)
8110 return TYPE_PRECISION (inner_type
) < TYPE_PRECISION (outer_type
)
8111 && TREE_UNSIGNED (inner_type
);
8117 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1))
8118 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 2));
8120 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8122 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8123 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8125 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8126 || tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8128 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8130 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8132 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
8133 case NON_LVALUE_EXPR
:
8134 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
8136 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t
));
8139 if (TREE_CODE (TREE_OPERAND (t
, 0)) == ADDR_EXPR
)
8141 tree fndecl
= TREE_OPERAND (TREE_OPERAND (t
, 0), 0);
8142 tree arglist
= TREE_OPERAND (t
, 1);
8143 if (TREE_CODE (fndecl
) == FUNCTION_DECL
8144 && DECL_BUILT_IN (fndecl
)
8145 && DECL_BUILT_IN_CLASS (fndecl
) != BUILT_IN_MD
)
8146 switch (DECL_FUNCTION_CODE (fndecl
))
8149 case BUILT_IN_CABSL
:
8150 case BUILT_IN_CABSF
:
8155 case BUILT_IN_FABSF
:
8156 case BUILT_IN_FABSL
:
8158 case BUILT_IN_SQRTF
:
8159 case BUILT_IN_SQRTL
:
8163 case BUILT_IN_ATANF
:
8164 case BUILT_IN_ATANL
:
8166 case BUILT_IN_CEILF
:
8167 case BUILT_IN_CEILL
:
8168 case BUILT_IN_FLOOR
:
8169 case BUILT_IN_FLOORF
:
8170 case BUILT_IN_FLOORL
:
8171 return tree_expr_nonnegative_p (TREE_VALUE (arglist
));
8176 return tree_expr_nonnegative_p (TREE_VALUE (arglist
));
8183 /* ... fall through ... */
8186 if (truth_value_p (TREE_CODE (t
)))
8187 /* Truth values evaluate to 0 or 1, which is nonnegative. */
8191 /* We don't know sign of `t', so be conservative and return false. */
8195 /* Return true if `r' is known to be non-negative.
8196 Only handles constants at the moment. */
8199 rtl_expr_nonnegative_p (r
)
8202 switch (GET_CODE (r
))
8205 return INTVAL (r
) >= 0;
8208 if (GET_MODE (r
) == VOIDmode
)
8209 return CONST_DOUBLE_HIGH (r
) >= 0;
8217 units
= CONST_VECTOR_NUNITS (r
);
8219 for (i
= 0; i
< units
; ++i
)
8221 elt
= CONST_VECTOR_ELT (r
, i
);
8222 if (!rtl_expr_nonnegative_p (elt
))
8231 /* These are always nonnegative. */
8239 #include "gt-fold-const.h"