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,
3 1999, 2000, 2001 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. */
56 static void encode
PARAMS ((HOST_WIDE_INT
*,
57 unsigned HOST_WIDE_INT
,
59 static void decode
PARAMS ((HOST_WIDE_INT
*,
60 unsigned HOST_WIDE_INT
*,
62 #ifndef REAL_ARITHMETIC
63 static void exact_real_inverse_1
PARAMS ((PTR
));
65 static tree negate_expr
PARAMS ((tree
));
66 static tree split_tree
PARAMS ((tree
, enum tree_code
, tree
*, tree
*,
68 static tree associate_trees
PARAMS ((tree
, tree
, enum tree_code
, tree
));
69 static tree int_const_binop
PARAMS ((enum tree_code
, tree
, tree
, int));
70 static void const_binop_1
PARAMS ((PTR
));
71 static tree const_binop
PARAMS ((enum tree_code
, tree
, tree
, int));
72 static hashval_t size_htab_hash
PARAMS ((const void *));
73 static int size_htab_eq
PARAMS ((const void *, const void *));
74 static void fold_convert_1
PARAMS ((PTR
));
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 truth_value_p
PARAMS ((enum tree_code
));
79 static int operand_equal_for_comparison_p
PARAMS ((tree
, tree
, tree
));
80 static int twoval_comparison_p
PARAMS ((tree
, tree
*, tree
*, int *));
81 static tree eval_subst
PARAMS ((tree
, tree
, tree
, tree
, tree
));
82 static tree omit_one_operand
PARAMS ((tree
, tree
, tree
));
83 static tree pedantic_omit_one_operand
PARAMS ((tree
, tree
, tree
));
84 static tree distribute_bit_expr
PARAMS ((enum tree_code
, tree
, tree
, tree
));
85 static tree make_bit_field_ref
PARAMS ((tree
, tree
, int, int, int));
86 static tree optimize_bit_field_compare
PARAMS ((enum tree_code
, tree
,
88 static tree decode_field_reference
PARAMS ((tree
, HOST_WIDE_INT
*,
90 enum machine_mode
*, int *,
91 int *, tree
*, tree
*));
92 static int all_ones_mask_p
PARAMS ((tree
, int));
93 static int simple_operand_p
PARAMS ((tree
));
94 static tree range_binop
PARAMS ((enum tree_code
, tree
, tree
, int,
96 static tree make_range
PARAMS ((tree
, int *, tree
*, tree
*));
97 static tree build_range_check
PARAMS ((tree
, tree
, int, tree
, tree
));
98 static int merge_ranges
PARAMS ((int *, tree
*, tree
*, int, tree
, tree
,
100 static tree fold_range_test
PARAMS ((tree
));
101 static tree unextend
PARAMS ((tree
, int, int, tree
));
102 static tree fold_truthop
PARAMS ((enum tree_code
, tree
, tree
, tree
));
103 static tree optimize_minmax_comparison
PARAMS ((tree
));
104 static tree extract_muldiv
PARAMS ((tree
, tree
, enum tree_code
, tree
));
105 static tree strip_compound_expr
PARAMS ((tree
, tree
));
106 static int multiple_of_p
PARAMS ((tree
, tree
, tree
));
107 static tree constant_boolean_node
PARAMS ((int, tree
));
108 static int count_cond
PARAMS ((tree
, int));
109 static tree fold_binary_op_with_conditional_arg
110 PARAMS ((enum tree_code
, tree
, tree
, tree
, int));
113 #define BRANCH_COST 1
116 #if defined(HOST_EBCDIC)
117 /* bit 8 is significant in EBCDIC */
118 #define CHARMASK 0xff
120 #define CHARMASK 0x7f
123 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
124 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
125 and SUM1. Then this yields nonzero if overflow occurred during the
128 Overflow occurs if A and B have the same sign, but A and SUM differ in
129 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
131 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
133 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
134 We do that by representing the two-word integer in 4 words, with only
135 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
136 number. The value of the word is LOWPART + HIGHPART * BASE. */
139 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
140 #define HIGHPART(x) \
141 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
142 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
144 /* Unpack a two-word integer into 4 words.
145 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
146 WORDS points to the array of HOST_WIDE_INTs. */
149 encode (words
, low
, hi
)
150 HOST_WIDE_INT
*words
;
151 unsigned HOST_WIDE_INT low
;
154 words
[0] = LOWPART (low
);
155 words
[1] = HIGHPART (low
);
156 words
[2] = LOWPART (hi
);
157 words
[3] = HIGHPART (hi
);
160 /* Pack an array of 4 words into a two-word integer.
161 WORDS points to the array of words.
162 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
165 decode (words
, low
, hi
)
166 HOST_WIDE_INT
*words
;
167 unsigned HOST_WIDE_INT
*low
;
170 *low
= words
[0] + words
[1] * BASE
;
171 *hi
= words
[2] + words
[3] * BASE
;
174 /* Make the integer constant T valid for its type by setting to 0 or 1 all
175 the bits in the constant that don't belong in the type.
177 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
178 nonzero, a signed overflow has already occurred in calculating T, so
181 Make the real constant T valid for its type by calling CHECK_FLOAT_VALUE,
185 force_fit_type (t
, overflow
)
189 unsigned HOST_WIDE_INT low
;
193 if (TREE_CODE (t
) == REAL_CST
)
195 #ifdef CHECK_FLOAT_VALUE
196 CHECK_FLOAT_VALUE (TYPE_MODE (TREE_TYPE (t
)), TREE_REAL_CST (t
),
202 else if (TREE_CODE (t
) != INTEGER_CST
)
205 low
= TREE_INT_CST_LOW (t
);
206 high
= TREE_INT_CST_HIGH (t
);
208 if (POINTER_TYPE_P (TREE_TYPE (t
)))
211 prec
= TYPE_PRECISION (TREE_TYPE (t
));
213 /* First clear all bits that are beyond the type's precision. */
215 if (prec
== 2 * HOST_BITS_PER_WIDE_INT
)
217 else if (prec
> HOST_BITS_PER_WIDE_INT
)
218 TREE_INT_CST_HIGH (t
)
219 &= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
222 TREE_INT_CST_HIGH (t
) = 0;
223 if (prec
< HOST_BITS_PER_WIDE_INT
)
224 TREE_INT_CST_LOW (t
) &= ~((unsigned HOST_WIDE_INT
) (-1) << prec
);
227 /* Unsigned types do not suffer sign extension or overflow unless they
229 if (TREE_UNSIGNED (TREE_TYPE (t
))
230 && ! (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
231 && TYPE_IS_SIZETYPE (TREE_TYPE (t
))))
234 /* If the value's sign bit is set, extend the sign. */
235 if (prec
!= 2 * HOST_BITS_PER_WIDE_INT
236 && (prec
> HOST_BITS_PER_WIDE_INT
237 ? 0 != (TREE_INT_CST_HIGH (t
)
239 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)))
240 : 0 != (TREE_INT_CST_LOW (t
)
241 & ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1)))))
243 /* Value is negative:
244 set to 1 all the bits that are outside this type's precision. */
245 if (prec
> HOST_BITS_PER_WIDE_INT
)
246 TREE_INT_CST_HIGH (t
)
247 |= ((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
250 TREE_INT_CST_HIGH (t
) = -1;
251 if (prec
< HOST_BITS_PER_WIDE_INT
)
252 TREE_INT_CST_LOW (t
) |= ((unsigned HOST_WIDE_INT
) (-1) << prec
);
256 /* Return nonzero if signed overflow occurred. */
258 ((overflow
| (low
^ TREE_INT_CST_LOW (t
)) | (high
^ TREE_INT_CST_HIGH (t
)))
262 /* Add two doubleword integers with doubleword result.
263 Each argument is given as two `HOST_WIDE_INT' pieces.
264 One argument is L1 and H1; the other, L2 and H2.
265 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
268 add_double (l1
, h1
, l2
, h2
, lv
, hv
)
269 unsigned HOST_WIDE_INT l1
, l2
;
270 HOST_WIDE_INT h1
, h2
;
271 unsigned HOST_WIDE_INT
*lv
;
274 unsigned HOST_WIDE_INT l
;
278 h
= h1
+ h2
+ (l
< l1
);
282 return OVERFLOW_SUM_SIGN (h1
, h2
, h
);
285 /* Negate a doubleword integer with doubleword result.
286 Return nonzero if the operation overflows, assuming it's signed.
287 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
288 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
291 neg_double (l1
, h1
, lv
, hv
)
292 unsigned HOST_WIDE_INT l1
;
294 unsigned HOST_WIDE_INT
*lv
;
301 return (*hv
& h1
) < 0;
311 /* Multiply two doubleword integers with doubleword result.
312 Return nonzero if the operation overflows, assuming it's signed.
313 Each argument is given as two `HOST_WIDE_INT' pieces.
314 One argument is L1 and H1; the other, L2 and H2.
315 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
318 mul_double (l1
, h1
, l2
, h2
, lv
, hv
)
319 unsigned HOST_WIDE_INT l1
, l2
;
320 HOST_WIDE_INT h1
, h2
;
321 unsigned HOST_WIDE_INT
*lv
;
324 HOST_WIDE_INT arg1
[4];
325 HOST_WIDE_INT arg2
[4];
326 HOST_WIDE_INT prod
[4 * 2];
327 unsigned HOST_WIDE_INT carry
;
329 unsigned HOST_WIDE_INT toplow
, neglow
;
330 HOST_WIDE_INT tophigh
, neghigh
;
332 encode (arg1
, l1
, h1
);
333 encode (arg2
, l2
, h2
);
335 memset ((char *) prod
, 0, sizeof prod
);
337 for (i
= 0; i
< 4; i
++)
340 for (j
= 0; j
< 4; j
++)
343 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
344 carry
+= arg1
[i
] * arg2
[j
];
345 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
347 prod
[k
] = LOWPART (carry
);
348 carry
= HIGHPART (carry
);
353 decode (prod
, lv
, hv
); /* This ignores prod[4] through prod[4*2-1] */
355 /* Check for overflow by calculating the top half of the answer in full;
356 it should agree with the low half's sign bit. */
357 decode (prod
+ 4, &toplow
, &tophigh
);
360 neg_double (l2
, h2
, &neglow
, &neghigh
);
361 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
365 neg_double (l1
, h1
, &neglow
, &neghigh
);
366 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
368 return (*hv
< 0 ? ~(toplow
& tophigh
) : toplow
| tophigh
) != 0;
371 /* Shift the doubleword integer in L1, H1 left by COUNT places
372 keeping only PREC bits of result.
373 Shift right if COUNT is negative.
374 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
375 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
378 lshift_double (l1
, h1
, count
, prec
, lv
, hv
, arith
)
379 unsigned HOST_WIDE_INT l1
;
380 HOST_WIDE_INT h1
, count
;
382 unsigned HOST_WIDE_INT
*lv
;
386 unsigned HOST_WIDE_INT signmask
;
390 rshift_double (l1
, h1
, -count
, prec
, lv
, hv
, arith
);
394 #ifdef SHIFT_COUNT_TRUNCATED
395 if (SHIFT_COUNT_TRUNCATED
)
399 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
401 /* Shifting by the host word size is undefined according to the
402 ANSI standard, so we must handle this as a special case. */
406 else if (count
>= HOST_BITS_PER_WIDE_INT
)
408 *hv
= l1
<< (count
- HOST_BITS_PER_WIDE_INT
);
413 *hv
= (((unsigned HOST_WIDE_INT
) h1
<< count
)
414 | (l1
>> (HOST_BITS_PER_WIDE_INT
- count
- 1) >> 1));
418 /* Sign extend all bits that are beyond the precision. */
420 signmask
= -((prec
> HOST_BITS_PER_WIDE_INT
421 ? (*hv
>> (prec
- HOST_BITS_PER_WIDE_INT
- 1))
422 : (*lv
>> (prec
- 1))) & 1);
424 if (prec
>= 2 * HOST_BITS_PER_WIDE_INT
)
426 else if (prec
>= HOST_BITS_PER_WIDE_INT
)
428 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
429 *hv
|= signmask
<< (prec
- HOST_BITS_PER_WIDE_INT
);
434 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << prec
);
435 *lv
|= signmask
<< prec
;
439 /* Shift the doubleword integer in L1, H1 right by COUNT places
440 keeping only PREC bits of result. COUNT must be positive.
441 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
442 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
445 rshift_double (l1
, h1
, count
, prec
, lv
, hv
, arith
)
446 unsigned HOST_WIDE_INT l1
;
447 HOST_WIDE_INT h1
, count
;
449 unsigned HOST_WIDE_INT
*lv
;
453 unsigned HOST_WIDE_INT signmask
;
456 ? -((unsigned HOST_WIDE_INT
) h1
>> (HOST_BITS_PER_WIDE_INT
- 1))
459 #ifdef SHIFT_COUNT_TRUNCATED
460 if (SHIFT_COUNT_TRUNCATED
)
464 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
466 /* Shifting by the host word size is undefined according to the
467 ANSI standard, so we must handle this as a special case. */
471 else if (count
>= HOST_BITS_PER_WIDE_INT
)
474 *lv
= (unsigned HOST_WIDE_INT
) h1
>> (count
- HOST_BITS_PER_WIDE_INT
);
478 *hv
= (unsigned HOST_WIDE_INT
) h1
>> count
;
480 | ((unsigned HOST_WIDE_INT
) h1
<< (HOST_BITS_PER_WIDE_INT
- count
- 1) << 1));
483 /* Zero / sign extend all bits that are beyond the precision. */
485 if (count
>= (HOST_WIDE_INT
)prec
)
490 else if ((prec
- count
) >= 2 * HOST_BITS_PER_WIDE_INT
)
492 else if ((prec
- count
) >= HOST_BITS_PER_WIDE_INT
)
494 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- count
- HOST_BITS_PER_WIDE_INT
));
495 *hv
|= signmask
<< (prec
- count
- HOST_BITS_PER_WIDE_INT
);
500 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << (prec
- count
));
501 *lv
|= signmask
<< (prec
- count
);
505 /* Rotate the doubleword integer in L1, H1 left by COUNT places
506 keeping only PREC bits of result.
507 Rotate right if COUNT is negative.
508 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
511 lrotate_double (l1
, h1
, count
, prec
, lv
, hv
)
512 unsigned HOST_WIDE_INT l1
;
513 HOST_WIDE_INT h1
, count
;
515 unsigned HOST_WIDE_INT
*lv
;
518 unsigned HOST_WIDE_INT s1l
, s2l
;
519 HOST_WIDE_INT s1h
, s2h
;
525 lshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
526 rshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
531 /* Rotate the doubleword integer in L1, H1 left by COUNT places
532 keeping only PREC bits of result. COUNT must be positive.
533 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
536 rrotate_double (l1
, h1
, count
, prec
, lv
, hv
)
537 unsigned HOST_WIDE_INT l1
;
538 HOST_WIDE_INT h1
, count
;
540 unsigned HOST_WIDE_INT
*lv
;
543 unsigned HOST_WIDE_INT s1l
, s2l
;
544 HOST_WIDE_INT s1h
, s2h
;
550 rshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
551 lshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
556 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
557 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
558 CODE is a tree code for a kind of division, one of
559 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
561 It controls how the quotient is rounded to an integer.
562 Return nonzero if the operation overflows.
563 UNS nonzero says do unsigned division. */
566 div_and_round_double (code
, uns
,
567 lnum_orig
, hnum_orig
, lden_orig
, hden_orig
,
568 lquo
, hquo
, lrem
, hrem
)
571 unsigned HOST_WIDE_INT lnum_orig
; /* num == numerator == dividend */
572 HOST_WIDE_INT hnum_orig
;
573 unsigned HOST_WIDE_INT lden_orig
; /* den == denominator == divisor */
574 HOST_WIDE_INT hden_orig
;
575 unsigned HOST_WIDE_INT
*lquo
, *lrem
;
576 HOST_WIDE_INT
*hquo
, *hrem
;
579 HOST_WIDE_INT num
[4 + 1]; /* extra element for scaling. */
580 HOST_WIDE_INT den
[4], quo
[4];
582 unsigned HOST_WIDE_INT work
;
583 unsigned HOST_WIDE_INT carry
= 0;
584 unsigned HOST_WIDE_INT lnum
= lnum_orig
;
585 HOST_WIDE_INT hnum
= hnum_orig
;
586 unsigned HOST_WIDE_INT lden
= lden_orig
;
587 HOST_WIDE_INT hden
= hden_orig
;
590 if (hden
== 0 && lden
== 0)
591 overflow
= 1, lden
= 1;
593 /* calculate quotient sign and convert operands to unsigned. */
599 /* (minimum integer) / (-1) is the only overflow case. */
600 if (neg_double (lnum
, hnum
, &lnum
, &hnum
)
601 && ((HOST_WIDE_INT
) lden
& hden
) == -1)
607 neg_double (lden
, hden
, &lden
, &hden
);
611 if (hnum
== 0 && hden
== 0)
612 { /* single precision */
614 /* This unsigned division rounds toward zero. */
620 { /* trivial case: dividend < divisor */
621 /* hden != 0 already checked. */
628 memset ((char *) quo
, 0, sizeof quo
);
630 memset ((char *) num
, 0, sizeof num
); /* to zero 9th element */
631 memset ((char *) den
, 0, sizeof den
);
633 encode (num
, lnum
, hnum
);
634 encode (den
, lden
, hden
);
636 /* Special code for when the divisor < BASE. */
637 if (hden
== 0 && lden
< (unsigned HOST_WIDE_INT
) BASE
)
639 /* hnum != 0 already checked. */
640 for (i
= 4 - 1; i
>= 0; i
--)
642 work
= num
[i
] + carry
* BASE
;
643 quo
[i
] = work
/ lden
;
649 /* Full double precision division,
650 with thanks to Don Knuth's "Seminumerical Algorithms". */
651 int num_hi_sig
, den_hi_sig
;
652 unsigned HOST_WIDE_INT quo_est
, scale
;
654 /* Find the highest non-zero divisor digit. */
655 for (i
= 4 - 1;; i
--)
662 /* Insure that the first digit of the divisor is at least BASE/2.
663 This is required by the quotient digit estimation algorithm. */
665 scale
= BASE
/ (den
[den_hi_sig
] + 1);
667 { /* scale divisor and dividend */
669 for (i
= 0; i
<= 4 - 1; i
++)
671 work
= (num
[i
] * scale
) + carry
;
672 num
[i
] = LOWPART (work
);
673 carry
= HIGHPART (work
);
678 for (i
= 0; i
<= 4 - 1; i
++)
680 work
= (den
[i
] * scale
) + carry
;
681 den
[i
] = LOWPART (work
);
682 carry
= HIGHPART (work
);
683 if (den
[i
] != 0) den_hi_sig
= i
;
690 for (i
= num_hi_sig
- den_hi_sig
- 1; i
>= 0; i
--)
692 /* Guess the next quotient digit, quo_est, by dividing the first
693 two remaining dividend digits by the high order quotient digit.
694 quo_est is never low and is at most 2 high. */
695 unsigned HOST_WIDE_INT tmp
;
697 num_hi_sig
= i
+ den_hi_sig
+ 1;
698 work
= num
[num_hi_sig
] * BASE
+ num
[num_hi_sig
- 1];
699 if (num
[num_hi_sig
] != den
[den_hi_sig
])
700 quo_est
= work
/ den
[den_hi_sig
];
704 /* Refine quo_est so it's usually correct, and at most one high. */
705 tmp
= work
- quo_est
* den
[den_hi_sig
];
707 && (den
[den_hi_sig
- 1] * quo_est
708 > (tmp
* BASE
+ num
[num_hi_sig
- 2])))
711 /* Try QUO_EST as the quotient digit, by multiplying the
712 divisor by QUO_EST and subtracting from the remaining dividend.
713 Keep in mind that QUO_EST is the I - 1st digit. */
716 for (j
= 0; j
<= den_hi_sig
; j
++)
718 work
= quo_est
* den
[j
] + carry
;
719 carry
= HIGHPART (work
);
720 work
= num
[i
+ j
] - LOWPART (work
);
721 num
[i
+ j
] = LOWPART (work
);
722 carry
+= HIGHPART (work
) != 0;
725 /* If quo_est was high by one, then num[i] went negative and
726 we need to correct things. */
727 if (num
[num_hi_sig
] < carry
)
730 carry
= 0; /* add divisor back in */
731 for (j
= 0; j
<= den_hi_sig
; j
++)
733 work
= num
[i
+ j
] + den
[j
] + carry
;
734 carry
= HIGHPART (work
);
735 num
[i
+ j
] = LOWPART (work
);
738 num
[num_hi_sig
] += carry
;
741 /* Store the quotient digit. */
746 decode (quo
, lquo
, hquo
);
749 /* if result is negative, make it so. */
751 neg_double (*lquo
, *hquo
, lquo
, hquo
);
753 /* compute trial remainder: rem = num - (quo * den) */
754 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
755 neg_double (*lrem
, *hrem
, lrem
, hrem
);
756 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
761 case TRUNC_MOD_EXPR
: /* round toward zero */
762 case EXACT_DIV_EXPR
: /* for this one, it shouldn't matter */
766 case FLOOR_MOD_EXPR
: /* round toward negative infinity */
767 if (quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio < 0 && rem != 0 */
770 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1,
778 case CEIL_MOD_EXPR
: /* round toward positive infinity */
779 if (!quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio > 0 && rem != 0 */
781 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
789 case ROUND_MOD_EXPR
: /* round to closest integer */
791 unsigned HOST_WIDE_INT labs_rem
= *lrem
;
792 HOST_WIDE_INT habs_rem
= *hrem
;
793 unsigned HOST_WIDE_INT labs_den
= lden
, ltwice
;
794 HOST_WIDE_INT habs_den
= hden
, htwice
;
796 /* Get absolute values */
798 neg_double (*lrem
, *hrem
, &labs_rem
, &habs_rem
);
800 neg_double (lden
, hden
, &labs_den
, &habs_den
);
802 /* If (2 * abs (lrem) >= abs (lden)) */
803 mul_double ((HOST_WIDE_INT
) 2, (HOST_WIDE_INT
) 0,
804 labs_rem
, habs_rem
, <wice
, &htwice
);
806 if (((unsigned HOST_WIDE_INT
) habs_den
807 < (unsigned HOST_WIDE_INT
) htwice
)
808 || (((unsigned HOST_WIDE_INT
) habs_den
809 == (unsigned HOST_WIDE_INT
) htwice
)
810 && (labs_den
< ltwice
)))
814 add_double (*lquo
, *hquo
,
815 (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1, lquo
, hquo
);
818 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
830 /* compute true remainder: rem = num - (quo * den) */
831 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
832 neg_double (*lrem
, *hrem
, lrem
, hrem
);
833 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
837 #ifndef REAL_ARITHMETIC
838 /* Effectively truncate a real value to represent the nearest possible value
839 in a narrower mode. The result is actually represented in the same data
840 type as the argument, but its value is usually different.
842 A trap may occur during the FP operations and it is the responsibility
843 of the calling function to have a handler established. */
846 real_value_truncate (mode
, arg
)
847 enum machine_mode mode
;
850 return REAL_VALUE_TRUNCATE (mode
, arg
);
853 #if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
855 /* Check for infinity in an IEEE double precision number. */
861 /* The IEEE 64-bit double format. */
866 unsigned exponent
: 11;
867 unsigned mantissa1
: 20;
868 unsigned mantissa2
: 32;
871 unsigned mantissa2
: 32;
872 unsigned mantissa1
: 20;
873 unsigned exponent
: 11;
879 if (u
.big_endian
.sign
== 1)
882 return (u
.big_endian
.exponent
== 2047
883 && u
.big_endian
.mantissa1
== 0
884 && u
.big_endian
.mantissa2
== 0);
889 return (u
.little_endian
.exponent
== 2047
890 && u
.little_endian
.mantissa1
== 0
891 && u
.little_endian
.mantissa2
== 0);
895 /* Check whether an IEEE double precision number is a NaN. */
901 /* The IEEE 64-bit double format. */
906 unsigned exponent
: 11;
907 unsigned mantissa1
: 20;
908 unsigned mantissa2
: 32;
911 unsigned mantissa2
: 32;
912 unsigned mantissa1
: 20;
913 unsigned exponent
: 11;
919 if (u
.big_endian
.sign
== 1)
922 return (u
.big_endian
.exponent
== 2047
923 && (u
.big_endian
.mantissa1
!= 0
924 || u
.big_endian
.mantissa2
!= 0));
929 return (u
.little_endian
.exponent
== 2047
930 && (u
.little_endian
.mantissa1
!= 0
931 || u
.little_endian
.mantissa2
!= 0));
935 /* Check for a negative IEEE double precision number. */
941 /* The IEEE 64-bit double format. */
946 unsigned exponent
: 11;
947 unsigned mantissa1
: 20;
948 unsigned mantissa2
: 32;
951 unsigned mantissa2
: 32;
952 unsigned mantissa1
: 20;
953 unsigned exponent
: 11;
959 if (u
.big_endian
.sign
== 1)
962 return u
.big_endian
.sign
;
967 return u
.little_endian
.sign
;
970 #else /* Target not IEEE */
972 /* Let's assume other float formats don't have infinity.
973 (This can be overridden by redefining REAL_VALUE_ISINF.) */
977 REAL_VALUE_TYPE x ATTRIBUTE_UNUSED
;
982 /* Let's assume other float formats don't have NaNs.
983 (This can be overridden by redefining REAL_VALUE_ISNAN.) */
987 REAL_VALUE_TYPE x ATTRIBUTE_UNUSED
;
992 /* Let's assume other float formats don't have minus zero.
993 (This can be overridden by redefining REAL_VALUE_NEGATIVE.) */
1001 #endif /* Target not IEEE */
1003 /* Try to change R into its exact multiplicative inverse in machine mode
1004 MODE. Return nonzero function value if successful. */
1005 struct exact_real_inverse_args
1008 enum machine_mode mode
;
1013 exact_real_inverse_1 (p
)
1016 struct exact_real_inverse_args
*args
=
1017 (struct exact_real_inverse_args
*) p
;
1019 enum machine_mode mode
= args
->mode
;
1020 REAL_VALUE_TYPE
*r
= args
->r
;
1025 unsigned short i
[4];
1028 #ifdef CHECK_FLOAT_VALUE
1032 /* Set array index to the less significant bits in the unions, depending
1033 on the endian-ness of the host doubles. */
1034 #if HOST_FLOAT_FORMAT == VAX_FLOAT_FORMAT \
1035 || HOST_FLOAT_FORMAT == IBM_FLOAT_FORMAT
1038 # define K (2 * HOST_FLOAT_WORDS_BIG_ENDIAN)
1041 /* Domain check the argument. */
1046 #ifdef REAL_INFINITY
1047 if (REAL_VALUE_ISINF (x
.d
) || REAL_VALUE_ISNAN (x
.d
))
1051 /* Compute the reciprocal and check for numerical exactness.
1052 It is unnecessary to check all the significand bits to determine
1053 whether X is a power of 2. If X is not, then it is impossible for
1054 the bottom half significand of both X and 1/X to be all zero bits.
1055 Hence we ignore the data structure of the top half and examine only
1056 the low order bits of the two significands. */
1058 if (x
.i
[K
] != 0 || x
.i
[K
+ 1] != 0 || t
.i
[K
] != 0 || t
.i
[K
+ 1] != 0)
1061 /* Truncate to the required mode and range-check the result. */
1062 y
.d
= REAL_VALUE_TRUNCATE (mode
, t
.d
);
1063 #ifdef CHECK_FLOAT_VALUE
1065 if (CHECK_FLOAT_VALUE (mode
, y
.d
, i
))
1069 /* Fail if truncation changed the value. */
1070 if (y
.d
!= t
.d
|| y
.d
== 0.0)
1073 #ifdef REAL_INFINITY
1074 if (REAL_VALUE_ISINF (y
.d
) || REAL_VALUE_ISNAN (y
.d
))
1078 /* Output the reciprocal and return success flag. */
1092 exact_real_inverse (mode
, r
)
1093 enum machine_mode mode
;
1096 struct exact_real_inverse_args args
;
1098 /* Disable if insufficient information on the data structure. */
1099 #if HOST_FLOAT_FORMAT == UNKNOWN_FLOAT_FORMAT
1103 /* Usually disable if bounds checks are not reliable. */
1104 if ((HOST_FLOAT_FORMAT
!= TARGET_FLOAT_FORMAT
) && !flag_pretend_float
)
1110 if (do_float_handler (exact_real_inverse_1
, (PTR
) &args
))
1111 return args
.success
;
1115 /* Convert C99 hexadecimal floating point string constant S. Return
1116 real value type in mode MODE. This function uses the host computer's
1117 floating point arithmetic when there is no REAL_ARITHMETIC. */
1120 real_hex_to_f (s
, mode
)
1122 enum machine_mode mode
;
1126 unsigned HOST_WIDE_INT low
, high
;
1127 int shcount
, nrmcount
, k
;
1128 int sign
, expsign
, isfloat
;
1129 int lost
= 0;/* Nonzero low order bits shifted out and discarded. */
1130 int frexpon
= 0; /* Bits after the decimal point. */
1131 int expon
= 0; /* Value of exponent. */
1132 int decpt
= 0; /* How many decimal points. */
1133 int gotp
= 0; /* How many P's. */
1140 while (*p
== ' ' || *p
== '\t')
1143 /* Sign, if any, comes first. */
1151 /* The string is supposed to start with 0x or 0X . */
1155 if (*p
== 'x' || *p
== 'X')
1169 while ((c
= *p
) != '\0')
1174 if (k
>= 'a' && k
<= 'f')
1181 if ((high
& 0xf0000000) == 0)
1183 high
= (high
<< 4) + ((low
>> 28) & 15);
1184 low
= (low
<< 4) + k
;
1191 /* Record nonzero lost bits. */
1204 else if (c
== 'p' || c
== 'P')
1208 /* Sign of exponent. */
1215 /* Value of exponent.
1216 The exponent field is a decimal integer. */
1217 while (ISDIGIT (*p
))
1219 k
= (*p
++ & CHARMASK
) - '0';
1220 expon
= 10 * expon
+ k
;
1224 /* F suffix is ambiguous in the significand part
1225 so it must appear after the decimal exponent field. */
1226 if (*p
== 'f' || *p
== 'F')
1234 else if (c
== 'l' || c
== 'L')
1243 /* Abort if last character read was not legitimate. */
1245 if ((c
!= '\0' && c
!= ' ' && c
!= '\n' && c
!= '\r') || (decpt
> 1))
1248 /* There must be either one decimal point or one p. */
1249 if (decpt
== 0 && gotp
== 0)
1253 if (high
== 0 && low
== 0)
1265 /* Leave a high guard bit for carry-out. */
1266 if ((high
& 0x80000000) != 0)
1269 low
= (low
>> 1) | (high
<< 31);
1274 if ((high
& 0xffff8000) == 0)
1276 high
= (high
<< 16) + ((low
>> 16) & 0xffff);
1281 while ((high
& 0xc0000000) == 0)
1283 high
= (high
<< 1) + ((low
>> 31) & 1);
1288 if (isfloat
|| GET_MODE_SIZE (mode
) == UNITS_PER_WORD
)
1290 /* Keep 24 bits precision, bits 0x7fffff80.
1291 Rounding bit is 0x40. */
1292 lost
= lost
| low
| (high
& 0x3f);
1296 if ((high
& 0x80) || lost
)
1303 /* We need real.c to do long double formats, so here default
1304 to double precision. */
1305 #if HOST_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
1307 Keep 53 bits precision, bits 0x7fffffff fffffc00.
1308 Rounding bit is low word 0x200. */
1309 lost
= lost
| (low
& 0x1ff);
1312 if ((low
& 0x400) || lost
)
1314 low
= (low
+ 0x200) & 0xfffffc00;
1321 /* Assume it's a VAX with 56-bit significand,
1322 bits 0x7fffffff ffffff80. */
1323 lost
= lost
| (low
& 0x7f);
1326 if ((low
& 0x80) || lost
)
1328 low
= (low
+ 0x40) & 0xffffff80;
1338 ip
= REAL_VALUE_LDEXP (ip
, 32) + (double) low
;
1339 /* Apply shifts and exponent value as power of 2. */
1340 ip
= REAL_VALUE_LDEXP (ip
, expon
- (nrmcount
+ frexpon
));
1347 #endif /* no REAL_ARITHMETIC */
1349 /* Given T, an expression, return the negation of T. Allow for T to be
1350 null, in which case return null. */
1362 type
= TREE_TYPE (t
);
1363 STRIP_SIGN_NOPS (t
);
1365 switch (TREE_CODE (t
))
1369 if (! TREE_UNSIGNED (type
)
1370 && 0 != (tem
= fold (build1 (NEGATE_EXPR
, type
, t
)))
1371 && ! TREE_OVERFLOW (tem
))
1376 return convert (type
, TREE_OPERAND (t
, 0));
1379 /* - (A - B) -> B - A */
1380 if (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
1381 return convert (type
,
1382 fold (build (MINUS_EXPR
, TREE_TYPE (t
),
1383 TREE_OPERAND (t
, 1),
1384 TREE_OPERAND (t
, 0))));
1391 return convert (type
, build1 (NEGATE_EXPR
, TREE_TYPE (t
), t
));
1394 /* Split a tree IN into a constant, literal and variable parts that could be
1395 combined with CODE to make IN. "constant" means an expression with
1396 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1397 commutative arithmetic operation. Store the constant part into *CONP,
1398 the literal in &LITP and return the variable part. If a part isn't
1399 present, set it to null. If the tree does not decompose in this way,
1400 return the entire tree as the variable part and the other parts as null.
1402 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1403 case, we negate an operand that was subtracted. If NEGATE_P is true, we
1404 are negating all of IN.
1406 If IN is itself a literal or constant, return it as appropriate.
1408 Note that we do not guarantee that any of the three values will be the
1409 same type as IN, but they will have the same signedness and mode. */
1412 split_tree (in
, code
, conp
, litp
, negate_p
)
1414 enum tree_code code
;
1423 /* Strip any conversions that don't change the machine mode or signedness. */
1424 STRIP_SIGN_NOPS (in
);
1426 if (TREE_CODE (in
) == INTEGER_CST
|| TREE_CODE (in
) == REAL_CST
)
1428 else if (TREE_CODE (in
) == code
1429 || (! FLOAT_TYPE_P (TREE_TYPE (in
))
1430 /* We can associate addition and subtraction together (even
1431 though the C standard doesn't say so) for integers because
1432 the value is not affected. For reals, the value might be
1433 affected, so we can't. */
1434 && ((code
== PLUS_EXPR
&& TREE_CODE (in
) == MINUS_EXPR
)
1435 || (code
== MINUS_EXPR
&& TREE_CODE (in
) == PLUS_EXPR
))))
1437 tree op0
= TREE_OPERAND (in
, 0);
1438 tree op1
= TREE_OPERAND (in
, 1);
1439 int neg1_p
= TREE_CODE (in
) == MINUS_EXPR
;
1440 int neg_litp_p
= 0, neg_conp_p
= 0, neg_var_p
= 0;
1442 /* First see if either of the operands is a literal, then a constant. */
1443 if (TREE_CODE (op0
) == INTEGER_CST
|| TREE_CODE (op0
) == REAL_CST
)
1444 *litp
= op0
, op0
= 0;
1445 else if (TREE_CODE (op1
) == INTEGER_CST
|| TREE_CODE (op1
) == REAL_CST
)
1446 *litp
= op1
, neg_litp_p
= neg1_p
, op1
= 0;
1448 if (op0
!= 0 && TREE_CONSTANT (op0
))
1449 *conp
= op0
, op0
= 0;
1450 else if (op1
!= 0 && TREE_CONSTANT (op1
))
1451 *conp
= op1
, neg_conp_p
= neg1_p
, op1
= 0;
1453 /* If we haven't dealt with either operand, this is not a case we can
1454 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1455 if (op0
!= 0 && op1
!= 0)
1460 var
= op1
, neg_var_p
= neg1_p
;
1462 /* Now do any needed negations. */
1463 if (neg_litp_p
) *litp
= negate_expr (*litp
);
1464 if (neg_conp_p
) *conp
= negate_expr (*conp
);
1465 if (neg_var_p
) var
= negate_expr (var
);
1467 else if (TREE_CONSTANT (in
))
1474 var
= negate_expr (var
);
1475 *conp
= negate_expr (*conp
);
1476 *litp
= negate_expr (*litp
);
1482 /* Re-associate trees split by the above function. T1 and T2 are either
1483 expressions to associate or null. Return the new expression, if any. If
1484 we build an operation, do it in TYPE and with CODE, except if CODE is a
1485 MINUS_EXPR, in which case we use PLUS_EXPR since split_tree will already
1486 have taken care of the negations. */
1489 associate_trees (t1
, t2
, code
, type
)
1491 enum tree_code code
;
1499 if (code
== MINUS_EXPR
)
1502 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1503 try to fold this since we will have infinite recursion. But do
1504 deal with any NEGATE_EXPRs. */
1505 if (TREE_CODE (t1
) == code
|| TREE_CODE (t2
) == code
1506 || TREE_CODE (t1
) == MINUS_EXPR
|| TREE_CODE (t2
) == MINUS_EXPR
)
1508 if (TREE_CODE (t1
) == NEGATE_EXPR
)
1509 return build (MINUS_EXPR
, type
, convert (type
, t2
),
1510 convert (type
, TREE_OPERAND (t1
, 0)));
1511 else if (TREE_CODE (t2
) == NEGATE_EXPR
)
1512 return build (MINUS_EXPR
, type
, convert (type
, t1
),
1513 convert (type
, TREE_OPERAND (t2
, 0)));
1515 return build (code
, type
, convert (type
, t1
), convert (type
, t2
));
1518 return fold (build (code
, type
, convert (type
, t1
), convert (type
, t2
)));
1521 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1522 to produce a new constant.
1524 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1527 int_const_binop (code
, arg1
, arg2
, notrunc
)
1528 enum tree_code code
;
1532 unsigned HOST_WIDE_INT int1l
, int2l
;
1533 HOST_WIDE_INT int1h
, int2h
;
1534 unsigned HOST_WIDE_INT low
;
1536 unsigned HOST_WIDE_INT garbagel
;
1537 HOST_WIDE_INT garbageh
;
1539 tree type
= TREE_TYPE (arg1
);
1540 int uns
= TREE_UNSIGNED (type
);
1542 = (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
));
1544 int no_overflow
= 0;
1546 int1l
= TREE_INT_CST_LOW (arg1
);
1547 int1h
= TREE_INT_CST_HIGH (arg1
);
1548 int2l
= TREE_INT_CST_LOW (arg2
);
1549 int2h
= TREE_INT_CST_HIGH (arg2
);
1554 low
= int1l
| int2l
, hi
= int1h
| int2h
;
1558 low
= int1l
^ int2l
, hi
= int1h
^ int2h
;
1562 low
= int1l
& int2l
, hi
= int1h
& int2h
;
1565 case BIT_ANDTC_EXPR
:
1566 low
= int1l
& ~int2l
, hi
= int1h
& ~int2h
;
1572 /* It's unclear from the C standard whether shifts can overflow.
1573 The following code ignores overflow; perhaps a C standard
1574 interpretation ruling is needed. */
1575 lshift_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1583 lrotate_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1588 overflow
= add_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1592 neg_double (int2l
, int2h
, &low
, &hi
);
1593 add_double (int1l
, int1h
, low
, hi
, &low
, &hi
);
1594 overflow
= OVERFLOW_SUM_SIGN (hi
, int2h
, int1h
);
1598 overflow
= mul_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1601 case TRUNC_DIV_EXPR
:
1602 case FLOOR_DIV_EXPR
: case CEIL_DIV_EXPR
:
1603 case EXACT_DIV_EXPR
:
1604 /* This is a shortcut for a common special case. */
1605 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1606 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1607 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1608 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1610 if (code
== CEIL_DIV_EXPR
)
1613 low
= int1l
/ int2l
, hi
= 0;
1617 /* ... fall through ... */
1619 case ROUND_DIV_EXPR
:
1620 if (int2h
== 0 && int2l
== 1)
1622 low
= int1l
, hi
= int1h
;
1625 if (int1l
== int2l
&& int1h
== int2h
1626 && ! (int1l
== 0 && int1h
== 0))
1631 overflow
= div_and_round_double (code
, uns
, int1l
, int1h
, int2l
, int2h
,
1632 &low
, &hi
, &garbagel
, &garbageh
);
1635 case TRUNC_MOD_EXPR
:
1636 case FLOOR_MOD_EXPR
: case CEIL_MOD_EXPR
:
1637 /* This is a shortcut for a common special case. */
1638 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1639 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1640 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1641 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1643 if (code
== CEIL_MOD_EXPR
)
1645 low
= int1l
% int2l
, hi
= 0;
1649 /* ... fall through ... */
1651 case ROUND_MOD_EXPR
:
1652 overflow
= div_and_round_double (code
, uns
,
1653 int1l
, int1h
, int2l
, int2h
,
1654 &garbagel
, &garbageh
, &low
, &hi
);
1660 low
= (((unsigned HOST_WIDE_INT
) int1h
1661 < (unsigned HOST_WIDE_INT
) int2h
)
1662 || (((unsigned HOST_WIDE_INT
) int1h
1663 == (unsigned HOST_WIDE_INT
) int2h
)
1666 low
= (int1h
< int2h
1667 || (int1h
== int2h
&& int1l
< int2l
));
1669 if (low
== (code
== MIN_EXPR
))
1670 low
= int1l
, hi
= int1h
;
1672 low
= int2l
, hi
= int2h
;
1679 /* If this is for a sizetype, can be represented as one (signed)
1680 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1683 && ((hi
== 0 && (HOST_WIDE_INT
) low
>= 0)
1684 || (hi
== -1 && (HOST_WIDE_INT
) low
< 0))
1685 && overflow
== 0 && ! TREE_OVERFLOW (arg1
) && ! TREE_OVERFLOW (arg2
))
1686 return size_int_type_wide (low
, type
);
1689 t
= build_int_2 (low
, hi
);
1690 TREE_TYPE (t
) = TREE_TYPE (arg1
);
1695 ? (!uns
|| is_sizetype
) && overflow
1696 : (force_fit_type (t
, (!uns
|| is_sizetype
) && overflow
)
1698 | TREE_OVERFLOW (arg1
)
1699 | TREE_OVERFLOW (arg2
));
1701 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1702 So check if force_fit_type truncated the value. */
1704 && ! TREE_OVERFLOW (t
)
1705 && (TREE_INT_CST_HIGH (t
) != hi
1706 || TREE_INT_CST_LOW (t
) != low
))
1707 TREE_OVERFLOW (t
) = 1;
1709 TREE_CONSTANT_OVERFLOW (t
) = (TREE_OVERFLOW (t
)
1710 | TREE_CONSTANT_OVERFLOW (arg1
)
1711 | TREE_CONSTANT_OVERFLOW (arg2
));
1715 /* Define input and output argument for const_binop_1. */
1718 enum tree_code code
; /* Input: tree code for operation. */
1719 tree type
; /* Input: tree type for operation. */
1720 REAL_VALUE_TYPE d1
, d2
; /* Input: floating point operands. */
1721 tree t
; /* Output: constant for result. */
1724 /* Do the real arithmetic for const_binop while protected by a
1725 float overflow handler. */
1728 const_binop_1 (data
)
1731 struct cb_args
*args
= (struct cb_args
*) data
;
1732 REAL_VALUE_TYPE value
;
1734 #ifdef REAL_ARITHMETIC
1735 REAL_ARITHMETIC (value
, args
->code
, args
->d1
, args
->d2
);
1740 value
= args
->d1
+ args
->d2
;
1744 value
= args
->d1
- args
->d2
;
1748 value
= args
->d1
* args
->d2
;
1752 #ifndef REAL_INFINITY
1757 value
= args
->d1
/ args
->d2
;
1761 value
= MIN (args
->d1
, args
->d2
);
1765 value
= MAX (args
->d1
, args
->d2
);
1771 #endif /* no REAL_ARITHMETIC */
1774 = build_real (args
->type
,
1775 real_value_truncate (TYPE_MODE (args
->type
), value
));
1778 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1779 constant. We assume ARG1 and ARG2 have the same data type, or at least
1780 are the same kind of constant and the same machine mode.
1782 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1785 const_binop (code
, arg1
, arg2
, notrunc
)
1786 enum tree_code code
;
1793 if (TREE_CODE (arg1
) == INTEGER_CST
)
1794 return int_const_binop (code
, arg1
, arg2
, notrunc
);
1796 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1797 if (TREE_CODE (arg1
) == REAL_CST
)
1803 struct cb_args args
;
1805 d1
= TREE_REAL_CST (arg1
);
1806 d2
= TREE_REAL_CST (arg2
);
1808 /* If either operand is a NaN, just return it. Otherwise, set up
1809 for floating-point trap; we return an overflow. */
1810 if (REAL_VALUE_ISNAN (d1
))
1812 else if (REAL_VALUE_ISNAN (d2
))
1815 /* Setup input for const_binop_1() */
1816 args
.type
= TREE_TYPE (arg1
);
1821 if (do_float_handler (const_binop_1
, (PTR
) &args
))
1822 /* Receive output from const_binop_1. */
1826 /* We got an exception from const_binop_1. */
1827 t
= copy_node (arg1
);
1832 = (force_fit_type (t
, overflow
)
1833 | TREE_OVERFLOW (arg1
) | TREE_OVERFLOW (arg2
));
1834 TREE_CONSTANT_OVERFLOW (t
)
1836 | TREE_CONSTANT_OVERFLOW (arg1
)
1837 | TREE_CONSTANT_OVERFLOW (arg2
);
1840 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1841 if (TREE_CODE (arg1
) == COMPLEX_CST
)
1843 tree type
= TREE_TYPE (arg1
);
1844 tree r1
= TREE_REALPART (arg1
);
1845 tree i1
= TREE_IMAGPART (arg1
);
1846 tree r2
= TREE_REALPART (arg2
);
1847 tree i2
= TREE_IMAGPART (arg2
);
1853 t
= build_complex (type
,
1854 const_binop (PLUS_EXPR
, r1
, r2
, notrunc
),
1855 const_binop (PLUS_EXPR
, i1
, i2
, notrunc
));
1859 t
= build_complex (type
,
1860 const_binop (MINUS_EXPR
, r1
, r2
, notrunc
),
1861 const_binop (MINUS_EXPR
, i1
, i2
, notrunc
));
1865 t
= build_complex (type
,
1866 const_binop (MINUS_EXPR
,
1867 const_binop (MULT_EXPR
,
1869 const_binop (MULT_EXPR
,
1872 const_binop (PLUS_EXPR
,
1873 const_binop (MULT_EXPR
,
1875 const_binop (MULT_EXPR
,
1883 = const_binop (PLUS_EXPR
,
1884 const_binop (MULT_EXPR
, r2
, r2
, notrunc
),
1885 const_binop (MULT_EXPR
, i2
, i2
, notrunc
),
1888 t
= build_complex (type
,
1890 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1891 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1892 const_binop (PLUS_EXPR
,
1893 const_binop (MULT_EXPR
, r1
, r2
,
1895 const_binop (MULT_EXPR
, i1
, i2
,
1898 magsquared
, notrunc
),
1900 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1901 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1902 const_binop (MINUS_EXPR
,
1903 const_binop (MULT_EXPR
, i1
, r2
,
1905 const_binop (MULT_EXPR
, r1
, i2
,
1908 magsquared
, notrunc
));
1920 /* These are the hash table functions for the hash table of INTEGER_CST
1921 nodes of a sizetype. */
1923 /* Return the hash code code X, an INTEGER_CST. */
1931 return (TREE_INT_CST_HIGH (t
) ^ TREE_INT_CST_LOW (t
)
1932 ^ (hashval_t
) ((long) TREE_TYPE (t
) >> 3)
1933 ^ (TREE_OVERFLOW (t
) << 20));
1936 /* Return non-zero if the value represented by *X (an INTEGER_CST tree node)
1937 is the same as that given by *Y, which is the same. */
1947 return (TREE_INT_CST_HIGH (xt
) == TREE_INT_CST_HIGH (yt
)
1948 && TREE_INT_CST_LOW (xt
) == TREE_INT_CST_LOW (yt
)
1949 && TREE_TYPE (xt
) == TREE_TYPE (yt
)
1950 && TREE_OVERFLOW (xt
) == TREE_OVERFLOW (yt
));
1953 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1954 bits are given by NUMBER and of the sizetype represented by KIND. */
1957 size_int_wide (number
, kind
)
1958 HOST_WIDE_INT number
;
1959 enum size_type_kind kind
;
1961 return size_int_type_wide (number
, sizetype_tab
[(int) kind
]);
1964 /* Likewise, but the desired type is specified explicitly. */
1967 size_int_type_wide (number
, type
)
1968 HOST_WIDE_INT number
;
1971 static htab_t size_htab
= 0;
1972 static tree new_const
= 0;
1977 size_htab
= htab_create (1024, size_htab_hash
, size_htab_eq
, NULL
);
1978 ggc_add_deletable_htab (size_htab
, NULL
, NULL
);
1979 new_const
= make_node (INTEGER_CST
);
1980 ggc_add_tree_root (&new_const
, 1);
1983 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1984 hash table, we return the value from the hash table. Otherwise, we
1985 place that in the hash table and make a new node for the next time. */
1986 TREE_INT_CST_LOW (new_const
) = number
;
1987 TREE_INT_CST_HIGH (new_const
) = number
< 0 ? -1 : 0;
1988 TREE_TYPE (new_const
) = type
;
1989 TREE_OVERFLOW (new_const
) = TREE_CONSTANT_OVERFLOW (new_const
)
1990 = force_fit_type (new_const
, 0);
1992 slot
= htab_find_slot (size_htab
, new_const
, INSERT
);
1997 *slot
= (PTR
) new_const
;
1998 new_const
= make_node (INTEGER_CST
);
2002 return (tree
) *slot
;
2005 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
2006 is a tree code. The type of the result is taken from the operands.
2007 Both must be the same type integer type and it must be a size type.
2008 If the operands are constant, so is the result. */
2011 size_binop (code
, arg0
, arg1
)
2012 enum tree_code code
;
2015 tree type
= TREE_TYPE (arg0
);
2017 if (TREE_CODE (type
) != INTEGER_TYPE
|| ! TYPE_IS_SIZETYPE (type
)
2018 || type
!= TREE_TYPE (arg1
))
2021 /* Handle the special case of two integer constants faster. */
2022 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
2024 /* And some specific cases even faster than that. */
2025 if (code
== PLUS_EXPR
&& integer_zerop (arg0
))
2027 else if ((code
== MINUS_EXPR
|| code
== PLUS_EXPR
)
2028 && integer_zerop (arg1
))
2030 else if (code
== MULT_EXPR
&& integer_onep (arg0
))
2033 /* Handle general case of two integer constants. */
2034 return int_const_binop (code
, arg0
, arg1
, 0);
2037 if (arg0
== error_mark_node
|| arg1
== error_mark_node
)
2038 return error_mark_node
;
2040 return fold (build (code
, type
, arg0
, arg1
));
2043 /* Given two values, either both of sizetype or both of bitsizetype,
2044 compute the difference between the two values. Return the value
2045 in signed type corresponding to the type of the operands. */
2048 size_diffop (arg0
, arg1
)
2051 tree type
= TREE_TYPE (arg0
);
2054 if (TREE_CODE (type
) != INTEGER_TYPE
|| ! TYPE_IS_SIZETYPE (type
)
2055 || type
!= TREE_TYPE (arg1
))
2058 /* If the type is already signed, just do the simple thing. */
2059 if (! TREE_UNSIGNED (type
))
2060 return size_binop (MINUS_EXPR
, arg0
, arg1
);
2062 ctype
= (type
== bitsizetype
|| type
== ubitsizetype
2063 ? sbitsizetype
: ssizetype
);
2065 /* If either operand is not a constant, do the conversions to the signed
2066 type and subtract. The hardware will do the right thing with any
2067 overflow in the subtraction. */
2068 if (TREE_CODE (arg0
) != INTEGER_CST
|| TREE_CODE (arg1
) != INTEGER_CST
)
2069 return size_binop (MINUS_EXPR
, convert (ctype
, arg0
),
2070 convert (ctype
, arg1
));
2072 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
2073 Otherwise, subtract the other way, convert to CTYPE (we know that can't
2074 overflow) and negate (which can't either). Special-case a result
2075 of zero while we're here. */
2076 if (tree_int_cst_equal (arg0
, arg1
))
2077 return convert (ctype
, integer_zero_node
);
2078 else if (tree_int_cst_lt (arg1
, arg0
))
2079 return convert (ctype
, size_binop (MINUS_EXPR
, arg0
, arg1
));
2081 return size_binop (MINUS_EXPR
, convert (ctype
, integer_zero_node
),
2082 convert (ctype
, size_binop (MINUS_EXPR
, arg1
, arg0
)));
2085 /* This structure is used to communicate arguments to fold_convert_1. */
2088 tree arg1
; /* Input: value to convert. */
2089 tree type
; /* Input: type to convert value to. */
2090 tree t
; /* Output: result of conversion. */
2093 /* Function to convert floating-point constants, protected by floating
2094 point exception handler. */
2097 fold_convert_1 (data
)
2100 struct fc_args
*args
= (struct fc_args
*) data
;
2102 args
->t
= build_real (args
->type
,
2103 real_value_truncate (TYPE_MODE (args
->type
),
2104 TREE_REAL_CST (args
->arg1
)));
2107 /* Given T, a tree representing type conversion of ARG1, a constant,
2108 return a constant tree representing the result of conversion. */
2111 fold_convert (t
, arg1
)
2115 tree type
= TREE_TYPE (t
);
2118 if (POINTER_TYPE_P (type
) || INTEGRAL_TYPE_P (type
))
2120 if (TREE_CODE (arg1
) == INTEGER_CST
)
2122 /* If we would build a constant wider than GCC supports,
2123 leave the conversion unfolded. */
2124 if (TYPE_PRECISION (type
) > 2 * HOST_BITS_PER_WIDE_INT
)
2127 /* If we are trying to make a sizetype for a small integer, use
2128 size_int to pick up cached types to reduce duplicate nodes. */
2129 if (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
)
2130 && !TREE_CONSTANT_OVERFLOW (arg1
)
2131 && compare_tree_int (arg1
, 10000) < 0)
2132 return size_int_type_wide (TREE_INT_CST_LOW (arg1
), type
);
2134 /* Given an integer constant, make new constant with new type,
2135 appropriately sign-extended or truncated. */
2136 t
= build_int_2 (TREE_INT_CST_LOW (arg1
),
2137 TREE_INT_CST_HIGH (arg1
));
2138 TREE_TYPE (t
) = type
;
2139 /* Indicate an overflow if (1) ARG1 already overflowed,
2140 or (2) force_fit_type indicates an overflow.
2141 Tell force_fit_type that an overflow has already occurred
2142 if ARG1 is a too-large unsigned value and T is signed.
2143 But don't indicate an overflow if converting a pointer. */
2145 = ((force_fit_type (t
,
2146 (TREE_INT_CST_HIGH (arg1
) < 0
2147 && (TREE_UNSIGNED (type
)
2148 < TREE_UNSIGNED (TREE_TYPE (arg1
)))))
2149 && ! POINTER_TYPE_P (TREE_TYPE (arg1
)))
2150 || TREE_OVERFLOW (arg1
));
2151 TREE_CONSTANT_OVERFLOW (t
)
2152 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
2154 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2155 else if (TREE_CODE (arg1
) == REAL_CST
)
2157 /* Don't initialize these, use assignments.
2158 Initialized local aggregates don't work on old compilers. */
2162 tree type1
= TREE_TYPE (arg1
);
2165 x
= TREE_REAL_CST (arg1
);
2166 l
= real_value_from_int_cst (type1
, TYPE_MIN_VALUE (type
));
2168 no_upper_bound
= (TYPE_MAX_VALUE (type
) == NULL
);
2169 if (!no_upper_bound
)
2170 u
= real_value_from_int_cst (type1
, TYPE_MAX_VALUE (type
));
2172 /* See if X will be in range after truncation towards 0.
2173 To compensate for truncation, move the bounds away from 0,
2174 but reject if X exactly equals the adjusted bounds. */
2175 #ifdef REAL_ARITHMETIC
2176 REAL_ARITHMETIC (l
, MINUS_EXPR
, l
, dconst1
);
2177 if (!no_upper_bound
)
2178 REAL_ARITHMETIC (u
, PLUS_EXPR
, u
, dconst1
);
2181 if (!no_upper_bound
)
2184 /* If X is a NaN, use zero instead and show we have an overflow.
2185 Otherwise, range check. */
2186 if (REAL_VALUE_ISNAN (x
))
2187 overflow
= 1, x
= dconst0
;
2188 else if (! (REAL_VALUES_LESS (l
, x
)
2190 && REAL_VALUES_LESS (x
, u
)))
2193 #ifndef REAL_ARITHMETIC
2195 HOST_WIDE_INT low
, high
;
2196 HOST_WIDE_INT half_word
2197 = (HOST_WIDE_INT
) 1 << (HOST_BITS_PER_WIDE_INT
/ 2);
2202 high
= (HOST_WIDE_INT
) (x
/ half_word
/ half_word
);
2203 x
-= (REAL_VALUE_TYPE
) high
* half_word
* half_word
;
2204 if (x
>= (REAL_VALUE_TYPE
) half_word
* half_word
/ 2)
2206 low
= x
- (REAL_VALUE_TYPE
) half_word
* half_word
/ 2;
2207 low
|= (HOST_WIDE_INT
) -1 << (HOST_BITS_PER_WIDE_INT
- 1);
2210 low
= (HOST_WIDE_INT
) x
;
2211 if (TREE_REAL_CST (arg1
) < 0)
2212 neg_double (low
, high
, &low
, &high
);
2213 t
= build_int_2 (low
, high
);
2217 HOST_WIDE_INT low
, high
;
2218 REAL_VALUE_TO_INT (&low
, &high
, x
);
2219 t
= build_int_2 (low
, high
);
2222 TREE_TYPE (t
) = type
;
2224 = TREE_OVERFLOW (arg1
) | force_fit_type (t
, overflow
);
2225 TREE_CONSTANT_OVERFLOW (t
)
2226 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
2228 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2229 TREE_TYPE (t
) = type
;
2231 else if (TREE_CODE (type
) == REAL_TYPE
)
2233 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2234 if (TREE_CODE (arg1
) == INTEGER_CST
)
2235 return build_real_from_int_cst (type
, arg1
);
2236 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2237 if (TREE_CODE (arg1
) == REAL_CST
)
2239 struct fc_args args
;
2241 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
2244 TREE_TYPE (arg1
) = type
;
2248 /* Setup input for fold_convert_1() */
2252 if (do_float_handler (fold_convert_1
, (PTR
) &args
))
2254 /* Receive output from fold_convert_1() */
2259 /* We got an exception from fold_convert_1() */
2261 t
= copy_node (arg1
);
2265 = TREE_OVERFLOW (arg1
) | force_fit_type (t
, overflow
);
2266 TREE_CONSTANT_OVERFLOW (t
)
2267 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
2271 TREE_CONSTANT (t
) = 1;
2275 /* Return an expr equal to X but certainly not valid as an lvalue. */
2283 /* These things are certainly not lvalues. */
2284 if (TREE_CODE (x
) == NON_LVALUE_EXPR
2285 || TREE_CODE (x
) == INTEGER_CST
2286 || TREE_CODE (x
) == REAL_CST
2287 || TREE_CODE (x
) == STRING_CST
2288 || TREE_CODE (x
) == ADDR_EXPR
)
2291 result
= build1 (NON_LVALUE_EXPR
, TREE_TYPE (x
), x
);
2292 TREE_CONSTANT (result
) = TREE_CONSTANT (x
);
2296 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2297 Zero means allow extended lvalues. */
2299 int pedantic_lvalues
;
2301 /* When pedantic, return an expr equal to X but certainly not valid as a
2302 pedantic lvalue. Otherwise, return X. */
2305 pedantic_non_lvalue (x
)
2308 if (pedantic_lvalues
)
2309 return non_lvalue (x
);
2314 /* Given a tree comparison code, return the code that is the logical inverse
2315 of the given code. It is not safe to do this for floating-point
2316 comparisons, except for NE_EXPR and EQ_EXPR. */
2318 static enum tree_code
2319 invert_tree_comparison (code
)
2320 enum tree_code code
;
2341 /* Similar, but return the comparison that results if the operands are
2342 swapped. This is safe for floating-point. */
2344 static enum tree_code
2345 swap_tree_comparison (code
)
2346 enum tree_code code
;
2366 /* Return nonzero if CODE is a tree code that represents a truth value. */
2369 truth_value_p (code
)
2370 enum tree_code code
;
2372 return (TREE_CODE_CLASS (code
) == '<'
2373 || code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
2374 || code
== TRUTH_OR_EXPR
|| code
== TRUTH_ORIF_EXPR
2375 || code
== TRUTH_XOR_EXPR
|| code
== TRUTH_NOT_EXPR
);
2378 /* Return nonzero if two operands are necessarily equal.
2379 If ONLY_CONST is non-zero, only return non-zero for constants.
2380 This function tests whether the operands are indistinguishable;
2381 it does not test whether they are equal using C's == operation.
2382 The distinction is important for IEEE floating point, because
2383 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2384 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
2387 operand_equal_p (arg0
, arg1
, only_const
)
2391 /* If both types don't have the same signedness, then we can't consider
2392 them equal. We must check this before the STRIP_NOPS calls
2393 because they may change the signedness of the arguments. */
2394 if (TREE_UNSIGNED (TREE_TYPE (arg0
)) != TREE_UNSIGNED (TREE_TYPE (arg1
)))
2400 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
2401 /* This is needed for conversions and for COMPONENT_REF.
2402 Might as well play it safe and always test this. */
2403 || TREE_CODE (TREE_TYPE (arg0
)) == ERROR_MARK
2404 || TREE_CODE (TREE_TYPE (arg1
)) == ERROR_MARK
2405 || TYPE_MODE (TREE_TYPE (arg0
)) != TYPE_MODE (TREE_TYPE (arg1
)))
2408 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2409 We don't care about side effects in that case because the SAVE_EXPR
2410 takes care of that for us. In all other cases, two expressions are
2411 equal if they have no side effects. If we have two identical
2412 expressions with side effects that should be treated the same due
2413 to the only side effects being identical SAVE_EXPR's, that will
2414 be detected in the recursive calls below. */
2415 if (arg0
== arg1
&& ! only_const
2416 && (TREE_CODE (arg0
) == SAVE_EXPR
2417 || (! TREE_SIDE_EFFECTS (arg0
) && ! TREE_SIDE_EFFECTS (arg1
))))
2420 /* Next handle constant cases, those for which we can return 1 even
2421 if ONLY_CONST is set. */
2422 if (TREE_CONSTANT (arg0
) && TREE_CONSTANT (arg1
))
2423 switch (TREE_CODE (arg0
))
2426 return (! TREE_CONSTANT_OVERFLOW (arg0
)
2427 && ! TREE_CONSTANT_OVERFLOW (arg1
)
2428 && tree_int_cst_equal (arg0
, arg1
));
2431 return (! TREE_CONSTANT_OVERFLOW (arg0
)
2432 && ! TREE_CONSTANT_OVERFLOW (arg1
)
2433 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0
),
2434 TREE_REAL_CST (arg1
)));
2437 return (operand_equal_p (TREE_REALPART (arg0
), TREE_REALPART (arg1
),
2439 && operand_equal_p (TREE_IMAGPART (arg0
), TREE_IMAGPART (arg1
),
2443 return (TREE_STRING_LENGTH (arg0
) == TREE_STRING_LENGTH (arg1
)
2444 && ! memcmp (TREE_STRING_POINTER (arg0
),
2445 TREE_STRING_POINTER (arg1
),
2446 TREE_STRING_LENGTH (arg0
)));
2449 return operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0),
2458 switch (TREE_CODE_CLASS (TREE_CODE (arg0
)))
2461 /* Two conversions are equal only if signedness and modes match. */
2462 if ((TREE_CODE (arg0
) == NOP_EXPR
|| TREE_CODE (arg0
) == CONVERT_EXPR
)
2463 && (TREE_UNSIGNED (TREE_TYPE (arg0
))
2464 != TREE_UNSIGNED (TREE_TYPE (arg1
))))
2467 return operand_equal_p (TREE_OPERAND (arg0
, 0),
2468 TREE_OPERAND (arg1
, 0), 0);
2472 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0)
2473 && operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1),
2477 /* For commutative ops, allow the other order. */
2478 return ((TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MULT_EXPR
2479 || TREE_CODE (arg0
) == MIN_EXPR
|| TREE_CODE (arg0
) == MAX_EXPR
2480 || TREE_CODE (arg0
) == BIT_IOR_EXPR
2481 || TREE_CODE (arg0
) == BIT_XOR_EXPR
2482 || TREE_CODE (arg0
) == BIT_AND_EXPR
2483 || TREE_CODE (arg0
) == NE_EXPR
|| TREE_CODE (arg0
) == EQ_EXPR
)
2484 && operand_equal_p (TREE_OPERAND (arg0
, 0),
2485 TREE_OPERAND (arg1
, 1), 0)
2486 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2487 TREE_OPERAND (arg1
, 0), 0));
2490 /* If either of the pointer (or reference) expressions we are dereferencing
2491 contain a side effect, these cannot be equal. */
2492 if (TREE_SIDE_EFFECTS (arg0
)
2493 || TREE_SIDE_EFFECTS (arg1
))
2496 switch (TREE_CODE (arg0
))
2499 return operand_equal_p (TREE_OPERAND (arg0
, 0),
2500 TREE_OPERAND (arg1
, 0), 0);
2504 case ARRAY_RANGE_REF
:
2505 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
2506 TREE_OPERAND (arg1
, 0), 0)
2507 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2508 TREE_OPERAND (arg1
, 1), 0));
2511 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
2512 TREE_OPERAND (arg1
, 0), 0)
2513 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2514 TREE_OPERAND (arg1
, 1), 0)
2515 && operand_equal_p (TREE_OPERAND (arg0
, 2),
2516 TREE_OPERAND (arg1
, 2), 0));
2522 if (TREE_CODE (arg0
) == RTL_EXPR
)
2523 return rtx_equal_p (RTL_EXPR_RTL (arg0
), RTL_EXPR_RTL (arg1
));
2531 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2532 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2534 When in doubt, return 0. */
2537 operand_equal_for_comparison_p (arg0
, arg1
, other
)
2541 int unsignedp1
, unsignedpo
;
2542 tree primarg0
, primarg1
, primother
;
2543 unsigned int correct_width
;
2545 if (operand_equal_p (arg0
, arg1
, 0))
2548 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
2549 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
2552 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2553 and see if the inner values are the same. This removes any
2554 signedness comparison, which doesn't matter here. */
2555 primarg0
= arg0
, primarg1
= arg1
;
2556 STRIP_NOPS (primarg0
);
2557 STRIP_NOPS (primarg1
);
2558 if (operand_equal_p (primarg0
, primarg1
, 0))
2561 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2562 actual comparison operand, ARG0.
2564 First throw away any conversions to wider types
2565 already present in the operands. */
2567 primarg1
= get_narrower (arg1
, &unsignedp1
);
2568 primother
= get_narrower (other
, &unsignedpo
);
2570 correct_width
= TYPE_PRECISION (TREE_TYPE (arg1
));
2571 if (unsignedp1
== unsignedpo
2572 && TYPE_PRECISION (TREE_TYPE (primarg1
)) < correct_width
2573 && TYPE_PRECISION (TREE_TYPE (primother
)) < correct_width
)
2575 tree type
= TREE_TYPE (arg0
);
2577 /* Make sure shorter operand is extended the right way
2578 to match the longer operand. */
2579 primarg1
= convert (signed_or_unsigned_type (unsignedp1
,
2580 TREE_TYPE (primarg1
)),
2583 if (operand_equal_p (arg0
, convert (type
, primarg1
), 0))
2590 /* See if ARG is an expression that is either a comparison or is performing
2591 arithmetic on comparisons. The comparisons must only be comparing
2592 two different values, which will be stored in *CVAL1 and *CVAL2; if
2593 they are non-zero it means that some operands have already been found.
2594 No variables may be used anywhere else in the expression except in the
2595 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2596 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2598 If this is true, return 1. Otherwise, return zero. */
2601 twoval_comparison_p (arg
, cval1
, cval2
, save_p
)
2603 tree
*cval1
, *cval2
;
2606 enum tree_code code
= TREE_CODE (arg
);
2607 char class = TREE_CODE_CLASS (code
);
2609 /* We can handle some of the 'e' cases here. */
2610 if (class == 'e' && code
== TRUTH_NOT_EXPR
)
2612 else if (class == 'e'
2613 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
2614 || code
== COMPOUND_EXPR
))
2617 else if (class == 'e' && code
== SAVE_EXPR
&& SAVE_EXPR_RTL (arg
) == 0
2618 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg
, 0)))
2620 /* If we've already found a CVAL1 or CVAL2, this expression is
2621 two complex to handle. */
2622 if (*cval1
|| *cval2
)
2632 return twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
);
2635 return (twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
)
2636 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2637 cval1
, cval2
, save_p
));
2643 if (code
== COND_EXPR
)
2644 return (twoval_comparison_p (TREE_OPERAND (arg
, 0),
2645 cval1
, cval2
, save_p
)
2646 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2647 cval1
, cval2
, save_p
)
2648 && twoval_comparison_p (TREE_OPERAND (arg
, 2),
2649 cval1
, cval2
, save_p
));
2653 /* First see if we can handle the first operand, then the second. For
2654 the second operand, we know *CVAL1 can't be zero. It must be that
2655 one side of the comparison is each of the values; test for the
2656 case where this isn't true by failing if the two operands
2659 if (operand_equal_p (TREE_OPERAND (arg
, 0),
2660 TREE_OPERAND (arg
, 1), 0))
2664 *cval1
= TREE_OPERAND (arg
, 0);
2665 else if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 0), 0))
2667 else if (*cval2
== 0)
2668 *cval2
= TREE_OPERAND (arg
, 0);
2669 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 0), 0))
2674 if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 1), 0))
2676 else if (*cval2
== 0)
2677 *cval2
= TREE_OPERAND (arg
, 1);
2678 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 1), 0))
2690 /* ARG is a tree that is known to contain just arithmetic operations and
2691 comparisons. Evaluate the operations in the tree substituting NEW0 for
2692 any occurrence of OLD0 as an operand of a comparison and likewise for
2696 eval_subst (arg
, old0
, new0
, old1
, new1
)
2698 tree old0
, new0
, old1
, new1
;
2700 tree type
= TREE_TYPE (arg
);
2701 enum tree_code code
= TREE_CODE (arg
);
2702 char class = TREE_CODE_CLASS (code
);
2704 /* We can handle some of the 'e' cases here. */
2705 if (class == 'e' && code
== TRUTH_NOT_EXPR
)
2707 else if (class == 'e'
2708 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
))
2714 return fold (build1 (code
, type
,
2715 eval_subst (TREE_OPERAND (arg
, 0),
2716 old0
, new0
, old1
, new1
)));
2719 return fold (build (code
, type
,
2720 eval_subst (TREE_OPERAND (arg
, 0),
2721 old0
, new0
, old1
, new1
),
2722 eval_subst (TREE_OPERAND (arg
, 1),
2723 old0
, new0
, old1
, new1
)));
2729 return eval_subst (TREE_OPERAND (arg
, 0), old0
, new0
, old1
, new1
);
2732 return eval_subst (TREE_OPERAND (arg
, 1), old0
, new0
, old1
, new1
);
2735 return fold (build (code
, type
,
2736 eval_subst (TREE_OPERAND (arg
, 0),
2737 old0
, new0
, old1
, new1
),
2738 eval_subst (TREE_OPERAND (arg
, 1),
2739 old0
, new0
, old1
, new1
),
2740 eval_subst (TREE_OPERAND (arg
, 2),
2741 old0
, new0
, old1
, new1
)));
2745 /* fall through - ??? */
2749 tree arg0
= TREE_OPERAND (arg
, 0);
2750 tree arg1
= TREE_OPERAND (arg
, 1);
2752 /* We need to check both for exact equality and tree equality. The
2753 former will be true if the operand has a side-effect. In that
2754 case, we know the operand occurred exactly once. */
2756 if (arg0
== old0
|| operand_equal_p (arg0
, old0
, 0))
2758 else if (arg0
== old1
|| operand_equal_p (arg0
, old1
, 0))
2761 if (arg1
== old0
|| operand_equal_p (arg1
, old0
, 0))
2763 else if (arg1
== old1
|| operand_equal_p (arg1
, old1
, 0))
2766 return fold (build (code
, type
, arg0
, arg1
));
2774 /* Return a tree for the case when the result of an expression is RESULT
2775 converted to TYPE and OMITTED was previously an operand of the expression
2776 but is now not needed (e.g., we folded OMITTED * 0).
2778 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2779 the conversion of RESULT to TYPE. */
2782 omit_one_operand (type
, result
, omitted
)
2783 tree type
, result
, omitted
;
2785 tree t
= convert (type
, result
);
2787 if (TREE_SIDE_EFFECTS (omitted
))
2788 return build (COMPOUND_EXPR
, type
, omitted
, t
);
2790 return non_lvalue (t
);
2793 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2796 pedantic_omit_one_operand (type
, result
, omitted
)
2797 tree type
, result
, omitted
;
2799 tree t
= convert (type
, result
);
2801 if (TREE_SIDE_EFFECTS (omitted
))
2802 return build (COMPOUND_EXPR
, type
, omitted
, t
);
2804 return pedantic_non_lvalue (t
);
2807 /* Return a simplified tree node for the truth-negation of ARG. This
2808 never alters ARG itself. We assume that ARG is an operation that
2809 returns a truth value (0 or 1). */
2812 invert_truthvalue (arg
)
2815 tree type
= TREE_TYPE (arg
);
2816 enum tree_code code
= TREE_CODE (arg
);
2818 if (code
== ERROR_MARK
)
2821 /* If this is a comparison, we can simply invert it, except for
2822 floating-point non-equality comparisons, in which case we just
2823 enclose a TRUTH_NOT_EXPR around what we have. */
2825 if (TREE_CODE_CLASS (code
) == '<')
2827 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg
, 0)))
2828 && !flag_unsafe_math_optimizations
2831 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2833 return build (invert_tree_comparison (code
), type
,
2834 TREE_OPERAND (arg
, 0), TREE_OPERAND (arg
, 1));
2840 return convert (type
, build_int_2 (integer_zerop (arg
), 0));
2842 case TRUTH_AND_EXPR
:
2843 return build (TRUTH_OR_EXPR
, type
,
2844 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2845 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2848 return build (TRUTH_AND_EXPR
, type
,
2849 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2850 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2852 case TRUTH_XOR_EXPR
:
2853 /* Here we can invert either operand. We invert the first operand
2854 unless the second operand is a TRUTH_NOT_EXPR in which case our
2855 result is the XOR of the first operand with the inside of the
2856 negation of the second operand. */
2858 if (TREE_CODE (TREE_OPERAND (arg
, 1)) == TRUTH_NOT_EXPR
)
2859 return build (TRUTH_XOR_EXPR
, type
, TREE_OPERAND (arg
, 0),
2860 TREE_OPERAND (TREE_OPERAND (arg
, 1), 0));
2862 return build (TRUTH_XOR_EXPR
, type
,
2863 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2864 TREE_OPERAND (arg
, 1));
2866 case TRUTH_ANDIF_EXPR
:
2867 return build (TRUTH_ORIF_EXPR
, type
,
2868 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2869 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2871 case TRUTH_ORIF_EXPR
:
2872 return build (TRUTH_ANDIF_EXPR
, type
,
2873 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2874 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2876 case TRUTH_NOT_EXPR
:
2877 return TREE_OPERAND (arg
, 0);
2880 return build (COND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2881 invert_truthvalue (TREE_OPERAND (arg
, 1)),
2882 invert_truthvalue (TREE_OPERAND (arg
, 2)));
2885 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2886 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2888 case WITH_RECORD_EXPR
:
2889 return build (WITH_RECORD_EXPR
, type
,
2890 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2891 TREE_OPERAND (arg
, 1));
2893 case NON_LVALUE_EXPR
:
2894 return invert_truthvalue (TREE_OPERAND (arg
, 0));
2899 return build1 (TREE_CODE (arg
), type
,
2900 invert_truthvalue (TREE_OPERAND (arg
, 0)));
2903 if (!integer_onep (TREE_OPERAND (arg
, 1)))
2905 return build (EQ_EXPR
, type
, arg
, convert (type
, integer_zero_node
));
2908 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2910 case CLEANUP_POINT_EXPR
:
2911 return build1 (CLEANUP_POINT_EXPR
, type
,
2912 invert_truthvalue (TREE_OPERAND (arg
, 0)));
2917 if (TREE_CODE (TREE_TYPE (arg
)) != BOOLEAN_TYPE
)
2919 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2922 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2923 operands are another bit-wise operation with a common input. If so,
2924 distribute the bit operations to save an operation and possibly two if
2925 constants are involved. For example, convert
2926 (A | B) & (A | C) into A | (B & C)
2927 Further simplification will occur if B and C are constants.
2929 If this optimization cannot be done, 0 will be returned. */
2932 distribute_bit_expr (code
, type
, arg0
, arg1
)
2933 enum tree_code code
;
2940 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
2941 || TREE_CODE (arg0
) == code
2942 || (TREE_CODE (arg0
) != BIT_AND_EXPR
2943 && TREE_CODE (arg0
) != BIT_IOR_EXPR
))
2946 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0))
2948 common
= TREE_OPERAND (arg0
, 0);
2949 left
= TREE_OPERAND (arg0
, 1);
2950 right
= TREE_OPERAND (arg1
, 1);
2952 else if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 1), 0))
2954 common
= TREE_OPERAND (arg0
, 0);
2955 left
= TREE_OPERAND (arg0
, 1);
2956 right
= TREE_OPERAND (arg1
, 0);
2958 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 0), 0))
2960 common
= TREE_OPERAND (arg0
, 1);
2961 left
= TREE_OPERAND (arg0
, 0);
2962 right
= TREE_OPERAND (arg1
, 1);
2964 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1), 0))
2966 common
= TREE_OPERAND (arg0
, 1);
2967 left
= TREE_OPERAND (arg0
, 0);
2968 right
= TREE_OPERAND (arg1
, 0);
2973 return fold (build (TREE_CODE (arg0
), type
, common
,
2974 fold (build (code
, type
, left
, right
))));
2977 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2978 starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */
2981 make_bit_field_ref (inner
, type
, bitsize
, bitpos
, unsignedp
)
2984 int bitsize
, bitpos
;
2987 tree result
= build (BIT_FIELD_REF
, type
, inner
,
2988 size_int (bitsize
), bitsize_int (bitpos
));
2990 TREE_UNSIGNED (result
) = unsignedp
;
2995 /* Optimize a bit-field compare.
2997 There are two cases: First is a compare against a constant and the
2998 second is a comparison of two items where the fields are at the same
2999 bit position relative to the start of a chunk (byte, halfword, word)
3000 large enough to contain it. In these cases we can avoid the shift
3001 implicit in bitfield extractions.
3003 For constants, we emit a compare of the shifted constant with the
3004 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3005 compared. For two fields at the same position, we do the ANDs with the
3006 similar mask and compare the result of the ANDs.
3008 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3009 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3010 are the left and right operands of the comparison, respectively.
3012 If the optimization described above can be done, we return the resulting
3013 tree. Otherwise we return zero. */
3016 optimize_bit_field_compare (code
, compare_type
, lhs
, rhs
)
3017 enum tree_code code
;
3021 HOST_WIDE_INT lbitpos
, lbitsize
, rbitpos
, rbitsize
, nbitpos
, nbitsize
;
3022 tree type
= TREE_TYPE (lhs
);
3023 tree signed_type
, unsigned_type
;
3024 int const_p
= TREE_CODE (rhs
) == INTEGER_CST
;
3025 enum machine_mode lmode
, rmode
, nmode
;
3026 int lunsignedp
, runsignedp
;
3027 int lvolatilep
= 0, rvolatilep
= 0;
3028 tree linner
, rinner
= NULL_TREE
;
3032 /* Get all the information about the extractions being done. If the bit size
3033 if the same as the size of the underlying object, we aren't doing an
3034 extraction at all and so can do nothing. We also don't want to
3035 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3036 then will no longer be able to replace it. */
3037 linner
= get_inner_reference (lhs
, &lbitsize
, &lbitpos
, &offset
, &lmode
,
3038 &lunsignedp
, &lvolatilep
);
3039 if (linner
== lhs
|| lbitsize
== GET_MODE_BITSIZE (lmode
) || lbitsize
< 0
3040 || offset
!= 0 || TREE_CODE (linner
) == PLACEHOLDER_EXPR
)
3045 /* If this is not a constant, we can only do something if bit positions,
3046 sizes, and signedness are the same. */
3047 rinner
= get_inner_reference (rhs
, &rbitsize
, &rbitpos
, &offset
, &rmode
,
3048 &runsignedp
, &rvolatilep
);
3050 if (rinner
== rhs
|| lbitpos
!= rbitpos
|| lbitsize
!= rbitsize
3051 || lunsignedp
!= runsignedp
|| offset
!= 0
3052 || TREE_CODE (rinner
) == PLACEHOLDER_EXPR
)
3056 /* See if we can find a mode to refer to this field. We should be able to,
3057 but fail if we can't. */
3058 nmode
= get_best_mode (lbitsize
, lbitpos
,
3059 const_p
? TYPE_ALIGN (TREE_TYPE (linner
))
3060 : MIN (TYPE_ALIGN (TREE_TYPE (linner
)),
3061 TYPE_ALIGN (TREE_TYPE (rinner
))),
3062 word_mode
, lvolatilep
|| rvolatilep
);
3063 if (nmode
== VOIDmode
)
3066 /* Set signed and unsigned types of the precision of this mode for the
3068 signed_type
= type_for_mode (nmode
, 0);
3069 unsigned_type
= type_for_mode (nmode
, 1);
3071 /* Compute the bit position and size for the new reference and our offset
3072 within it. If the new reference is the same size as the original, we
3073 won't optimize anything, so return zero. */
3074 nbitsize
= GET_MODE_BITSIZE (nmode
);
3075 nbitpos
= lbitpos
& ~ (nbitsize
- 1);
3077 if (nbitsize
== lbitsize
)
3080 if (BYTES_BIG_ENDIAN
)
3081 lbitpos
= nbitsize
- lbitsize
- lbitpos
;
3083 /* Make the mask to be used against the extracted field. */
3084 mask
= build_int_2 (~0, ~0);
3085 TREE_TYPE (mask
) = unsigned_type
;
3086 force_fit_type (mask
, 0);
3087 mask
= convert (unsigned_type
, mask
);
3088 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (nbitsize
- lbitsize
), 0);
3089 mask
= const_binop (RSHIFT_EXPR
, mask
,
3090 size_int (nbitsize
- lbitsize
- lbitpos
), 0);
3093 /* If not comparing with constant, just rework the comparison
3095 return build (code
, compare_type
,
3096 build (BIT_AND_EXPR
, unsigned_type
,
3097 make_bit_field_ref (linner
, unsigned_type
,
3098 nbitsize
, nbitpos
, 1),
3100 build (BIT_AND_EXPR
, unsigned_type
,
3101 make_bit_field_ref (rinner
, unsigned_type
,
3102 nbitsize
, nbitpos
, 1),
3105 /* Otherwise, we are handling the constant case. See if the constant is too
3106 big for the field. Warn and return a tree of for 0 (false) if so. We do
3107 this not only for its own sake, but to avoid having to test for this
3108 error case below. If we didn't, we might generate wrong code.
3110 For unsigned fields, the constant shifted right by the field length should
3111 be all zero. For signed fields, the high-order bits should agree with
3116 if (! integer_zerop (const_binop (RSHIFT_EXPR
,
3117 convert (unsigned_type
, rhs
),
3118 size_int (lbitsize
), 0)))
3120 warning ("comparison is always %d due to width of bit-field",
3122 return convert (compare_type
,
3124 ? integer_one_node
: integer_zero_node
));
3129 tree tem
= const_binop (RSHIFT_EXPR
, convert (signed_type
, rhs
),
3130 size_int (lbitsize
- 1), 0);
3131 if (! integer_zerop (tem
) && ! integer_all_onesp (tem
))
3133 warning ("comparison is always %d due to width of bit-field",
3135 return convert (compare_type
,
3137 ? integer_one_node
: integer_zero_node
));
3141 /* Single-bit compares should always be against zero. */
3142 if (lbitsize
== 1 && ! integer_zerop (rhs
))
3144 code
= code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
;
3145 rhs
= convert (type
, integer_zero_node
);
3148 /* Make a new bitfield reference, shift the constant over the
3149 appropriate number of bits and mask it with the computed mask
3150 (in case this was a signed field). If we changed it, make a new one. */
3151 lhs
= make_bit_field_ref (linner
, unsigned_type
, nbitsize
, nbitpos
, 1);
3154 TREE_SIDE_EFFECTS (lhs
) = 1;
3155 TREE_THIS_VOLATILE (lhs
) = 1;
3158 rhs
= fold (const_binop (BIT_AND_EXPR
,
3159 const_binop (LSHIFT_EXPR
,
3160 convert (unsigned_type
, rhs
),
3161 size_int (lbitpos
), 0),
3164 return build (code
, compare_type
,
3165 build (BIT_AND_EXPR
, unsigned_type
, lhs
, mask
),
3169 /* Subroutine for fold_truthop: decode a field reference.
3171 If EXP is a comparison reference, we return the innermost reference.
3173 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3174 set to the starting bit number.
3176 If the innermost field can be completely contained in a mode-sized
3177 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3179 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3180 otherwise it is not changed.
3182 *PUNSIGNEDP is set to the signedness of the field.
3184 *PMASK is set to the mask used. This is either contained in a
3185 BIT_AND_EXPR or derived from the width of the field.
3187 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3189 Return 0 if this is not a component reference or is one that we can't
3190 do anything with. */
3193 decode_field_reference (exp
, pbitsize
, pbitpos
, pmode
, punsignedp
,
3194 pvolatilep
, pmask
, pand_mask
)
3196 HOST_WIDE_INT
*pbitsize
, *pbitpos
;
3197 enum machine_mode
*pmode
;
3198 int *punsignedp
, *pvolatilep
;
3203 tree mask
, inner
, offset
;
3205 unsigned int precision
;
3207 /* All the optimizations using this function assume integer fields.
3208 There are problems with FP fields since the type_for_size call
3209 below can fail for, e.g., XFmode. */
3210 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp
)))
3215 if (TREE_CODE (exp
) == BIT_AND_EXPR
)
3217 and_mask
= TREE_OPERAND (exp
, 1);
3218 exp
= TREE_OPERAND (exp
, 0);
3219 STRIP_NOPS (exp
); STRIP_NOPS (and_mask
);
3220 if (TREE_CODE (and_mask
) != INTEGER_CST
)
3224 inner
= get_inner_reference (exp
, pbitsize
, pbitpos
, &offset
, pmode
,
3225 punsignedp
, pvolatilep
);
3226 if ((inner
== exp
&& and_mask
== 0)
3227 || *pbitsize
< 0 || offset
!= 0
3228 || TREE_CODE (inner
) == PLACEHOLDER_EXPR
)
3231 /* Compute the mask to access the bitfield. */
3232 unsigned_type
= type_for_size (*pbitsize
, 1);
3233 precision
= TYPE_PRECISION (unsigned_type
);
3235 mask
= build_int_2 (~0, ~0);
3236 TREE_TYPE (mask
) = unsigned_type
;
3237 force_fit_type (mask
, 0);
3238 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
3239 mask
= const_binop (RSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
3241 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3243 mask
= fold (build (BIT_AND_EXPR
, unsigned_type
,
3244 convert (unsigned_type
, and_mask
), mask
));
3247 *pand_mask
= and_mask
;
3251 /* Return non-zero if MASK represents a mask of SIZE ones in the low-order
3255 all_ones_mask_p (mask
, size
)
3259 tree type
= TREE_TYPE (mask
);
3260 unsigned int precision
= TYPE_PRECISION (type
);
3263 tmask
= build_int_2 (~0, ~0);
3264 TREE_TYPE (tmask
) = signed_type (type
);
3265 force_fit_type (tmask
, 0);
3267 tree_int_cst_equal (mask
,
3268 const_binop (RSHIFT_EXPR
,
3269 const_binop (LSHIFT_EXPR
, tmask
,
3270 size_int (precision
- size
),
3272 size_int (precision
- size
), 0));
3275 /* Subroutine for fold_truthop: determine if an operand is simple enough
3276 to be evaluated unconditionally. */
3279 simple_operand_p (exp
)
3282 /* Strip any conversions that don't change the machine mode. */
3283 while ((TREE_CODE (exp
) == NOP_EXPR
3284 || TREE_CODE (exp
) == CONVERT_EXPR
)
3285 && (TYPE_MODE (TREE_TYPE (exp
))
3286 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp
, 0)))))
3287 exp
= TREE_OPERAND (exp
, 0);
3289 return (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'c'
3291 && ! TREE_ADDRESSABLE (exp
)
3292 && ! TREE_THIS_VOLATILE (exp
)
3293 && ! DECL_NONLOCAL (exp
)
3294 /* Don't regard global variables as simple. They may be
3295 allocated in ways unknown to the compiler (shared memory,
3296 #pragma weak, etc). */
3297 && ! TREE_PUBLIC (exp
)
3298 && ! DECL_EXTERNAL (exp
)
3299 /* Loading a static variable is unduly expensive, but global
3300 registers aren't expensive. */
3301 && (! TREE_STATIC (exp
) || DECL_REGISTER (exp
))));
3304 /* The following functions are subroutines to fold_range_test and allow it to
3305 try to change a logical combination of comparisons into a range test.
3308 X == 2 || X == 3 || X == 4 || X == 5
3312 (unsigned) (X - 2) <= 3
3314 We describe each set of comparisons as being either inside or outside
3315 a range, using a variable named like IN_P, and then describe the
3316 range with a lower and upper bound. If one of the bounds is omitted,
3317 it represents either the highest or lowest value of the type.
3319 In the comments below, we represent a range by two numbers in brackets
3320 preceded by a "+" to designate being inside that range, or a "-" to
3321 designate being outside that range, so the condition can be inverted by
3322 flipping the prefix. An omitted bound is represented by a "-". For
3323 example, "- [-, 10]" means being outside the range starting at the lowest
3324 possible value and ending at 10, in other words, being greater than 10.
3325 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3328 We set up things so that the missing bounds are handled in a consistent
3329 manner so neither a missing bound nor "true" and "false" need to be
3330 handled using a special case. */
3332 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3333 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3334 and UPPER1_P are nonzero if the respective argument is an upper bound
3335 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3336 must be specified for a comparison. ARG1 will be converted to ARG0's
3337 type if both are specified. */
3340 range_binop (code
, type
, arg0
, upper0_p
, arg1
, upper1_p
)
3341 enum tree_code code
;
3344 int upper0_p
, upper1_p
;
3350 /* If neither arg represents infinity, do the normal operation.
3351 Else, if not a comparison, return infinity. Else handle the special
3352 comparison rules. Note that most of the cases below won't occur, but
3353 are handled for consistency. */
3355 if (arg0
!= 0 && arg1
!= 0)
3357 tem
= fold (build (code
, type
!= 0 ? type
: TREE_TYPE (arg0
),
3358 arg0
, convert (TREE_TYPE (arg0
), arg1
)));
3360 return TREE_CODE (tem
) == INTEGER_CST
? tem
: 0;
3363 if (TREE_CODE_CLASS (code
) != '<')
3366 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3367 for neither. In real maths, we cannot assume open ended ranges are
3368 the same. But, this is computer arithmetic, where numbers are finite.
3369 We can therefore make the transformation of any unbounded range with
3370 the value Z, Z being greater than any representable number. This permits
3371 us to treat unbounded ranges as equal. */
3372 sgn0
= arg0
!= 0 ? 0 : (upper0_p
? 1 : -1);
3373 sgn1
= arg1
!= 0 ? 0 : (upper1_p
? 1 : -1);
3377 result
= sgn0
== sgn1
;
3380 result
= sgn0
!= sgn1
;
3383 result
= sgn0
< sgn1
;
3386 result
= sgn0
<= sgn1
;
3389 result
= sgn0
> sgn1
;
3392 result
= sgn0
>= sgn1
;
3398 return convert (type
, result
? integer_one_node
: integer_zero_node
);
3401 /* Given EXP, a logical expression, set the range it is testing into
3402 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3403 actually being tested. *PLOW and *PHIGH will be made of the same type
3404 as the returned expression. If EXP is not a comparison, we will most
3405 likely not be returning a useful value and range. */
3408 make_range (exp
, pin_p
, plow
, phigh
)
3413 enum tree_code code
;
3414 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
, type
= NULL_TREE
;
3415 tree orig_type
= NULL_TREE
;
3417 tree low
, high
, n_low
, n_high
;
3419 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3420 and see if we can refine the range. Some of the cases below may not
3421 happen, but it doesn't seem worth worrying about this. We "continue"
3422 the outer loop when we've changed something; otherwise we "break"
3423 the switch, which will "break" the while. */
3425 in_p
= 0, low
= high
= convert (TREE_TYPE (exp
), integer_zero_node
);
3429 code
= TREE_CODE (exp
);
3431 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code
)))
3433 arg0
= TREE_OPERAND (exp
, 0);
3434 if (TREE_CODE_CLASS (code
) == '<'
3435 || TREE_CODE_CLASS (code
) == '1'
3436 || TREE_CODE_CLASS (code
) == '2')
3437 type
= TREE_TYPE (arg0
);
3438 if (TREE_CODE_CLASS (code
) == '2'
3439 || TREE_CODE_CLASS (code
) == '<'
3440 || (TREE_CODE_CLASS (code
) == 'e'
3441 && TREE_CODE_LENGTH (code
) > 1))
3442 arg1
= TREE_OPERAND (exp
, 1);
3445 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3446 lose a cast by accident. */
3447 if (type
!= NULL_TREE
&& orig_type
== NULL_TREE
)
3452 case TRUTH_NOT_EXPR
:
3453 in_p
= ! in_p
, exp
= arg0
;
3456 case EQ_EXPR
: case NE_EXPR
:
3457 case LT_EXPR
: case LE_EXPR
: case GE_EXPR
: case GT_EXPR
:
3458 /* We can only do something if the range is testing for zero
3459 and if the second operand is an integer constant. Note that
3460 saying something is "in" the range we make is done by
3461 complementing IN_P since it will set in the initial case of
3462 being not equal to zero; "out" is leaving it alone. */
3463 if (low
== 0 || high
== 0
3464 || ! integer_zerop (low
) || ! integer_zerop (high
)
3465 || TREE_CODE (arg1
) != INTEGER_CST
)
3470 case NE_EXPR
: /* - [c, c] */
3473 case EQ_EXPR
: /* + [c, c] */
3474 in_p
= ! in_p
, low
= high
= arg1
;
3476 case GT_EXPR
: /* - [-, c] */
3477 low
= 0, high
= arg1
;
3479 case GE_EXPR
: /* + [c, -] */
3480 in_p
= ! in_p
, low
= arg1
, high
= 0;
3482 case LT_EXPR
: /* - [c, -] */
3483 low
= arg1
, high
= 0;
3485 case LE_EXPR
: /* + [-, c] */
3486 in_p
= ! in_p
, low
= 0, high
= arg1
;
3494 /* If this is an unsigned comparison, we also know that EXP is
3495 greater than or equal to zero. We base the range tests we make
3496 on that fact, so we record it here so we can parse existing
3498 if (TREE_UNSIGNED (type
) && (low
== 0 || high
== 0))
3500 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
, in_p
, low
, high
,
3501 1, convert (type
, integer_zero_node
),
3505 in_p
= n_in_p
, low
= n_low
, high
= n_high
;
3507 /* If the high bound is missing, but we
3508 have a low bound, reverse the range so
3509 it goes from zero to the low bound minus 1. */
3510 if (high
== 0 && low
)
3513 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low
, 0,
3514 integer_one_node
, 0);
3515 low
= convert (type
, integer_zero_node
);
3521 /* (-x) IN [a,b] -> x in [-b, -a] */
3522 n_low
= range_binop (MINUS_EXPR
, type
,
3523 convert (type
, integer_zero_node
), 0, high
, 1);
3524 n_high
= range_binop (MINUS_EXPR
, type
,
3525 convert (type
, integer_zero_node
), 0, low
, 0);
3526 low
= n_low
, high
= n_high
;
3532 exp
= build (MINUS_EXPR
, type
, negate_expr (arg0
),
3533 convert (type
, integer_one_node
));
3536 case PLUS_EXPR
: case MINUS_EXPR
:
3537 if (TREE_CODE (arg1
) != INTEGER_CST
)
3540 /* If EXP is signed, any overflow in the computation is undefined,
3541 so we don't worry about it so long as our computations on
3542 the bounds don't overflow. For unsigned, overflow is defined
3543 and this is exactly the right thing. */
3544 n_low
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3545 type
, low
, 0, arg1
, 0);
3546 n_high
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3547 type
, high
, 1, arg1
, 0);
3548 if ((n_low
!= 0 && TREE_OVERFLOW (n_low
))
3549 || (n_high
!= 0 && TREE_OVERFLOW (n_high
)))
3552 /* Check for an unsigned range which has wrapped around the maximum
3553 value thus making n_high < n_low, and normalize it. */
3554 if (n_low
&& n_high
&& tree_int_cst_lt (n_high
, n_low
))
3556 low
= range_binop (PLUS_EXPR
, type
, n_high
, 0,
3557 integer_one_node
, 0);
3558 high
= range_binop (MINUS_EXPR
, type
, n_low
, 0,
3559 integer_one_node
, 0);
3561 /* If the range is of the form +/- [ x+1, x ], we won't
3562 be able to normalize it. But then, it represents the
3563 whole range or the empty set, so make it
3565 if (tree_int_cst_equal (n_low
, low
)
3566 && tree_int_cst_equal (n_high
, high
))
3572 low
= n_low
, high
= n_high
;
3577 case NOP_EXPR
: case NON_LVALUE_EXPR
: case CONVERT_EXPR
:
3578 if (TYPE_PRECISION (type
) > TYPE_PRECISION (orig_type
))
3581 if (! INTEGRAL_TYPE_P (type
)
3582 || (low
!= 0 && ! int_fits_type_p (low
, type
))
3583 || (high
!= 0 && ! int_fits_type_p (high
, type
)))
3586 n_low
= low
, n_high
= high
;
3589 n_low
= convert (type
, n_low
);
3592 n_high
= convert (type
, n_high
);
3594 /* If we're converting from an unsigned to a signed type,
3595 we will be doing the comparison as unsigned. The tests above
3596 have already verified that LOW and HIGH are both positive.
3598 So we have to make sure that the original unsigned value will
3599 be interpreted as positive. */
3600 if (TREE_UNSIGNED (type
) && ! TREE_UNSIGNED (TREE_TYPE (exp
)))
3602 tree equiv_type
= type_for_mode (TYPE_MODE (type
), 1);
3605 /* A range without an upper bound is, naturally, unbounded.
3606 Since convert would have cropped a very large value, use
3607 the max value for the destination type. */
3609 = TYPE_MAX_VALUE (equiv_type
) ? TYPE_MAX_VALUE (equiv_type
)
3610 : TYPE_MAX_VALUE (type
);
3612 high_positive
= fold (build (RSHIFT_EXPR
, type
,
3613 convert (type
, high_positive
),
3614 convert (type
, integer_one_node
)));
3616 /* If the low bound is specified, "and" the range with the
3617 range for which the original unsigned value will be
3621 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3623 1, convert (type
, integer_zero_node
),
3627 in_p
= (n_in_p
== in_p
);
3631 /* Otherwise, "or" the range with the range of the input
3632 that will be interpreted as negative. */
3633 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3635 1, convert (type
, integer_zero_node
),
3639 in_p
= (in_p
!= n_in_p
);
3644 low
= n_low
, high
= n_high
;
3654 /* If EXP is a constant, we can evaluate whether this is true or false. */
3655 if (TREE_CODE (exp
) == INTEGER_CST
)
3657 in_p
= in_p
== (integer_onep (range_binop (GE_EXPR
, integer_type_node
,
3659 && integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3665 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
3669 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3670 type, TYPE, return an expression to test if EXP is in (or out of, depending
3671 on IN_P) the range. */
3674 build_range_check (type
, exp
, in_p
, low
, high
)
3680 tree etype
= TREE_TYPE (exp
);
3684 && (0 != (value
= build_range_check (type
, exp
, 1, low
, high
))))
3685 return invert_truthvalue (value
);
3687 else if (low
== 0 && high
== 0)
3688 return convert (type
, integer_one_node
);
3691 return fold (build (LE_EXPR
, type
, exp
, high
));
3694 return fold (build (GE_EXPR
, type
, exp
, low
));
3696 else if (operand_equal_p (low
, high
, 0))
3697 return fold (build (EQ_EXPR
, type
, exp
, low
));
3699 else if (TREE_UNSIGNED (etype
) && integer_zerop (low
))
3700 return build_range_check (type
, exp
, 1, 0, high
);
3702 else if (integer_zerop (low
))
3704 utype
= unsigned_type (etype
);
3705 return build_range_check (type
, convert (utype
, exp
), 1, 0,
3706 convert (utype
, high
));
3709 else if (0 != (value
= const_binop (MINUS_EXPR
, high
, low
, 0))
3710 && ! TREE_OVERFLOW (value
))
3711 return build_range_check (type
,
3712 fold (build (MINUS_EXPR
, etype
, exp
, low
)),
3713 1, convert (etype
, integer_zero_node
), value
);
3718 /* Given two ranges, see if we can merge them into one. Return 1 if we
3719 can, 0 if we can't. Set the output range into the specified parameters. */
3722 merge_ranges (pin_p
, plow
, phigh
, in0_p
, low0
, high0
, in1_p
, low1
, high1
)
3726 tree low0
, high0
, low1
, high1
;
3734 int lowequal
= ((low0
== 0 && low1
== 0)
3735 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3736 low0
, 0, low1
, 0)));
3737 int highequal
= ((high0
== 0 && high1
== 0)
3738 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3739 high0
, 1, high1
, 1)));
3741 /* Make range 0 be the range that starts first, or ends last if they
3742 start at the same value. Swap them if it isn't. */
3743 if (integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3746 && integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3747 high1
, 1, high0
, 1))))
3749 temp
= in0_p
, in0_p
= in1_p
, in1_p
= temp
;
3750 tem
= low0
, low0
= low1
, low1
= tem
;
3751 tem
= high0
, high0
= high1
, high1
= tem
;
3754 /* Now flag two cases, whether the ranges are disjoint or whether the
3755 second range is totally subsumed in the first. Note that the tests
3756 below are simplified by the ones above. */
3757 no_overlap
= integer_onep (range_binop (LT_EXPR
, integer_type_node
,
3758 high0
, 1, low1
, 0));
3759 subset
= integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3760 high1
, 1, high0
, 1));
3762 /* We now have four cases, depending on whether we are including or
3763 excluding the two ranges. */
3766 /* If they don't overlap, the result is false. If the second range
3767 is a subset it is the result. Otherwise, the range is from the start
3768 of the second to the end of the first. */
3770 in_p
= 0, low
= high
= 0;
3772 in_p
= 1, low
= low1
, high
= high1
;
3774 in_p
= 1, low
= low1
, high
= high0
;
3777 else if (in0_p
&& ! in1_p
)
3779 /* If they don't overlap, the result is the first range. If they are
3780 equal, the result is false. If the second range is a subset of the
3781 first, and the ranges begin at the same place, we go from just after
3782 the end of the first range to the end of the second. If the second
3783 range is not a subset of the first, or if it is a subset and both
3784 ranges end at the same place, the range starts at the start of the
3785 first range and ends just before the second range.
3786 Otherwise, we can't describe this as a single range. */
3788 in_p
= 1, low
= low0
, high
= high0
;
3789 else if (lowequal
&& highequal
)
3790 in_p
= 0, low
= high
= 0;
3791 else if (subset
&& lowequal
)
3793 in_p
= 1, high
= high0
;
3794 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high1
, 0,
3795 integer_one_node
, 0);
3797 else if (! subset
|| highequal
)
3799 in_p
= 1, low
= low0
;
3800 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low1
, 0,
3801 integer_one_node
, 0);
3807 else if (! in0_p
&& in1_p
)
3809 /* If they don't overlap, the result is the second range. If the second
3810 is a subset of the first, the result is false. Otherwise,
3811 the range starts just after the first range and ends at the
3812 end of the second. */
3814 in_p
= 1, low
= low1
, high
= high1
;
3815 else if (subset
|| highequal
)
3816 in_p
= 0, low
= high
= 0;
3819 in_p
= 1, high
= high1
;
3820 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high0
, 1,
3821 integer_one_node
, 0);
3827 /* The case where we are excluding both ranges. Here the complex case
3828 is if they don't overlap. In that case, the only time we have a
3829 range is if they are adjacent. If the second is a subset of the
3830 first, the result is the first. Otherwise, the range to exclude
3831 starts at the beginning of the first range and ends at the end of the
3835 if (integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3836 range_binop (PLUS_EXPR
, NULL_TREE
,
3838 integer_one_node
, 1),
3840 in_p
= 0, low
= low0
, high
= high1
;
3845 in_p
= 0, low
= low0
, high
= high0
;
3847 in_p
= 0, low
= low0
, high
= high1
;
3850 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
3854 /* EXP is some logical combination of boolean tests. See if we can
3855 merge it into some range test. Return the new tree if so. */
3858 fold_range_test (exp
)
3861 int or_op
= (TREE_CODE (exp
) == TRUTH_ORIF_EXPR
3862 || TREE_CODE (exp
) == TRUTH_OR_EXPR
);
3863 int in0_p
, in1_p
, in_p
;
3864 tree low0
, low1
, low
, high0
, high1
, high
;
3865 tree lhs
= make_range (TREE_OPERAND (exp
, 0), &in0_p
, &low0
, &high0
);
3866 tree rhs
= make_range (TREE_OPERAND (exp
, 1), &in1_p
, &low1
, &high1
);
3869 /* If this is an OR operation, invert both sides; we will invert
3870 again at the end. */
3872 in0_p
= ! in0_p
, in1_p
= ! in1_p
;
3874 /* If both expressions are the same, if we can merge the ranges, and we
3875 can build the range test, return it or it inverted. If one of the
3876 ranges is always true or always false, consider it to be the same
3877 expression as the other. */
3878 if ((lhs
== 0 || rhs
== 0 || operand_equal_p (lhs
, rhs
, 0))
3879 && merge_ranges (&in_p
, &low
, &high
, in0_p
, low0
, high0
,
3881 && 0 != (tem
= (build_range_check (TREE_TYPE (exp
),
3883 : rhs
!= 0 ? rhs
: integer_zero_node
,
3885 return or_op
? invert_truthvalue (tem
) : tem
;
3887 /* On machines where the branch cost is expensive, if this is a
3888 short-circuited branch and the underlying object on both sides
3889 is the same, make a non-short-circuit operation. */
3890 else if (BRANCH_COST
>= 2
3891 && lhs
!= 0 && rhs
!= 0
3892 && (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3893 || TREE_CODE (exp
) == TRUTH_ORIF_EXPR
)
3894 && operand_equal_p (lhs
, rhs
, 0))
3896 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3897 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3898 which cases we can't do this. */
3899 if (simple_operand_p (lhs
))
3900 return build (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3901 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
3902 TREE_TYPE (exp
), TREE_OPERAND (exp
, 0),
3903 TREE_OPERAND (exp
, 1));
3905 else if (global_bindings_p () == 0
3906 && ! contains_placeholder_p (lhs
))
3908 tree common
= save_expr (lhs
);
3910 if (0 != (lhs
= build_range_check (TREE_TYPE (exp
), common
,
3911 or_op
? ! in0_p
: in0_p
,
3913 && (0 != (rhs
= build_range_check (TREE_TYPE (exp
), common
,
3914 or_op
? ! in1_p
: in1_p
,
3916 return build (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3917 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
3918 TREE_TYPE (exp
), lhs
, rhs
);
3925 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3926 bit value. Arrange things so the extra bits will be set to zero if and
3927 only if C is signed-extended to its full width. If MASK is nonzero,
3928 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3931 unextend (c
, p
, unsignedp
, mask
)
3937 tree type
= TREE_TYPE (c
);
3938 int modesize
= GET_MODE_BITSIZE (TYPE_MODE (type
));
3941 if (p
== modesize
|| unsignedp
)
3944 /* We work by getting just the sign bit into the low-order bit, then
3945 into the high-order bit, then sign-extend. We then XOR that value
3947 temp
= const_binop (RSHIFT_EXPR
, c
, size_int (p
- 1), 0);
3948 temp
= const_binop (BIT_AND_EXPR
, temp
, size_int (1), 0);
3950 /* We must use a signed type in order to get an arithmetic right shift.
3951 However, we must also avoid introducing accidental overflows, so that
3952 a subsequent call to integer_zerop will work. Hence we must
3953 do the type conversion here. At this point, the constant is either
3954 zero or one, and the conversion to a signed type can never overflow.
3955 We could get an overflow if this conversion is done anywhere else. */
3956 if (TREE_UNSIGNED (type
))
3957 temp
= convert (signed_type (type
), temp
);
3959 temp
= const_binop (LSHIFT_EXPR
, temp
, size_int (modesize
- 1), 0);
3960 temp
= const_binop (RSHIFT_EXPR
, temp
, size_int (modesize
- p
- 1), 0);
3962 temp
= const_binop (BIT_AND_EXPR
, temp
, convert (TREE_TYPE (c
), mask
), 0);
3963 /* If necessary, convert the type back to match the type of C. */
3964 if (TREE_UNSIGNED (type
))
3965 temp
= convert (type
, temp
);
3967 return convert (type
, const_binop (BIT_XOR_EXPR
, c
, temp
, 0));
3970 /* Find ways of folding logical expressions of LHS and RHS:
3971 Try to merge two comparisons to the same innermost item.
3972 Look for range tests like "ch >= '0' && ch <= '9'".
3973 Look for combinations of simple terms on machines with expensive branches
3974 and evaluate the RHS unconditionally.
3976 For example, if we have p->a == 2 && p->b == 4 and we can make an
3977 object large enough to span both A and B, we can do this with a comparison
3978 against the object ANDed with the a mask.
3980 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3981 operations to do this with one comparison.
3983 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3984 function and the one above.
3986 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3987 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3989 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3992 We return the simplified tree or 0 if no optimization is possible. */
3995 fold_truthop (code
, truth_type
, lhs
, rhs
)
3996 enum tree_code code
;
3997 tree truth_type
, lhs
, rhs
;
3999 /* If this is the "or" of two comparisons, we can do something if
4000 the comparisons are NE_EXPR. If this is the "and", we can do something
4001 if the comparisons are EQ_EXPR. I.e.,
4002 (a->b == 2 && a->c == 4) can become (a->new == NEW).
4004 WANTED_CODE is this operation code. For single bit fields, we can
4005 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
4006 comparison for one-bit fields. */
4008 enum tree_code wanted_code
;
4009 enum tree_code lcode
, rcode
;
4010 tree ll_arg
, lr_arg
, rl_arg
, rr_arg
;
4011 tree ll_inner
, lr_inner
, rl_inner
, rr_inner
;
4012 HOST_WIDE_INT ll_bitsize
, ll_bitpos
, lr_bitsize
, lr_bitpos
;
4013 HOST_WIDE_INT rl_bitsize
, rl_bitpos
, rr_bitsize
, rr_bitpos
;
4014 HOST_WIDE_INT xll_bitpos
, xlr_bitpos
, xrl_bitpos
, xrr_bitpos
;
4015 HOST_WIDE_INT lnbitsize
, lnbitpos
, rnbitsize
, rnbitpos
;
4016 int ll_unsignedp
, lr_unsignedp
, rl_unsignedp
, rr_unsignedp
;
4017 enum machine_mode ll_mode
, lr_mode
, rl_mode
, rr_mode
;
4018 enum machine_mode lnmode
, rnmode
;
4019 tree ll_mask
, lr_mask
, rl_mask
, rr_mask
;
4020 tree ll_and_mask
, lr_and_mask
, rl_and_mask
, rr_and_mask
;
4021 tree l_const
, r_const
;
4022 tree lntype
, rntype
, result
;
4023 int first_bit
, end_bit
;
4026 /* Start by getting the comparison codes. Fail if anything is volatile.
4027 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
4028 it were surrounded with a NE_EXPR. */
4030 if (TREE_SIDE_EFFECTS (lhs
) || TREE_SIDE_EFFECTS (rhs
))
4033 lcode
= TREE_CODE (lhs
);
4034 rcode
= TREE_CODE (rhs
);
4036 if (lcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (lhs
, 1)))
4037 lcode
= NE_EXPR
, lhs
= build (NE_EXPR
, truth_type
, lhs
, integer_zero_node
);
4039 if (rcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (rhs
, 1)))
4040 rcode
= NE_EXPR
, rhs
= build (NE_EXPR
, truth_type
, rhs
, integer_zero_node
);
4042 if (TREE_CODE_CLASS (lcode
) != '<' || TREE_CODE_CLASS (rcode
) != '<')
4045 code
= ((code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
)
4046 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
);
4048 ll_arg
= TREE_OPERAND (lhs
, 0);
4049 lr_arg
= TREE_OPERAND (lhs
, 1);
4050 rl_arg
= TREE_OPERAND (rhs
, 0);
4051 rr_arg
= TREE_OPERAND (rhs
, 1);
4053 /* If the RHS can be evaluated unconditionally and its operands are
4054 simple, it wins to evaluate the RHS unconditionally on machines
4055 with expensive branches. In this case, this isn't a comparison
4056 that can be merged. Avoid doing this if the RHS is a floating-point
4057 comparison since those can trap. */
4059 if (BRANCH_COST
>= 2
4060 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg
))
4061 && simple_operand_p (rl_arg
)
4062 && simple_operand_p (rr_arg
))
4063 return build (code
, truth_type
, lhs
, rhs
);
4065 /* See if the comparisons can be merged. Then get all the parameters for
4068 if ((lcode
!= EQ_EXPR
&& lcode
!= NE_EXPR
)
4069 || (rcode
!= EQ_EXPR
&& rcode
!= NE_EXPR
))
4073 ll_inner
= decode_field_reference (ll_arg
,
4074 &ll_bitsize
, &ll_bitpos
, &ll_mode
,
4075 &ll_unsignedp
, &volatilep
, &ll_mask
,
4077 lr_inner
= decode_field_reference (lr_arg
,
4078 &lr_bitsize
, &lr_bitpos
, &lr_mode
,
4079 &lr_unsignedp
, &volatilep
, &lr_mask
,
4081 rl_inner
= decode_field_reference (rl_arg
,
4082 &rl_bitsize
, &rl_bitpos
, &rl_mode
,
4083 &rl_unsignedp
, &volatilep
, &rl_mask
,
4085 rr_inner
= decode_field_reference (rr_arg
,
4086 &rr_bitsize
, &rr_bitpos
, &rr_mode
,
4087 &rr_unsignedp
, &volatilep
, &rr_mask
,
4090 /* It must be true that the inner operation on the lhs of each
4091 comparison must be the same if we are to be able to do anything.
4092 Then see if we have constants. If not, the same must be true for
4094 if (volatilep
|| ll_inner
== 0 || rl_inner
== 0
4095 || ! operand_equal_p (ll_inner
, rl_inner
, 0))
4098 if (TREE_CODE (lr_arg
) == INTEGER_CST
4099 && TREE_CODE (rr_arg
) == INTEGER_CST
)
4100 l_const
= lr_arg
, r_const
= rr_arg
;
4101 else if (lr_inner
== 0 || rr_inner
== 0
4102 || ! operand_equal_p (lr_inner
, rr_inner
, 0))
4105 l_const
= r_const
= 0;
4107 /* If either comparison code is not correct for our logical operation,
4108 fail. However, we can convert a one-bit comparison against zero into
4109 the opposite comparison against that bit being set in the field. */
4111 wanted_code
= (code
== TRUTH_AND_EXPR
? EQ_EXPR
: NE_EXPR
);
4112 if (lcode
!= wanted_code
)
4114 if (l_const
&& integer_zerop (l_const
) && integer_pow2p (ll_mask
))
4116 /* Make the left operand unsigned, since we are only interested
4117 in the value of one bit. Otherwise we are doing the wrong
4126 /* This is analogous to the code for l_const above. */
4127 if (rcode
!= wanted_code
)
4129 if (r_const
&& integer_zerop (r_const
) && integer_pow2p (rl_mask
))
4138 /* See if we can find a mode that contains both fields being compared on
4139 the left. If we can't, fail. Otherwise, update all constants and masks
4140 to be relative to a field of that size. */
4141 first_bit
= MIN (ll_bitpos
, rl_bitpos
);
4142 end_bit
= MAX (ll_bitpos
+ ll_bitsize
, rl_bitpos
+ rl_bitsize
);
4143 lnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
4144 TYPE_ALIGN (TREE_TYPE (ll_inner
)), word_mode
,
4146 if (lnmode
== VOIDmode
)
4149 lnbitsize
= GET_MODE_BITSIZE (lnmode
);
4150 lnbitpos
= first_bit
& ~ (lnbitsize
- 1);
4151 lntype
= type_for_size (lnbitsize
, 1);
4152 xll_bitpos
= ll_bitpos
- lnbitpos
, xrl_bitpos
= rl_bitpos
- lnbitpos
;
4154 if (BYTES_BIG_ENDIAN
)
4156 xll_bitpos
= lnbitsize
- xll_bitpos
- ll_bitsize
;
4157 xrl_bitpos
= lnbitsize
- xrl_bitpos
- rl_bitsize
;
4160 ll_mask
= const_binop (LSHIFT_EXPR
, convert (lntype
, ll_mask
),
4161 size_int (xll_bitpos
), 0);
4162 rl_mask
= const_binop (LSHIFT_EXPR
, convert (lntype
, rl_mask
),
4163 size_int (xrl_bitpos
), 0);
4167 l_const
= convert (lntype
, l_const
);
4168 l_const
= unextend (l_const
, ll_bitsize
, ll_unsignedp
, ll_and_mask
);
4169 l_const
= const_binop (LSHIFT_EXPR
, l_const
, size_int (xll_bitpos
), 0);
4170 if (! integer_zerop (const_binop (BIT_AND_EXPR
, l_const
,
4171 fold (build1 (BIT_NOT_EXPR
,
4175 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
4177 return convert (truth_type
,
4178 wanted_code
== NE_EXPR
4179 ? integer_one_node
: integer_zero_node
);
4184 r_const
= convert (lntype
, r_const
);
4185 r_const
= unextend (r_const
, rl_bitsize
, rl_unsignedp
, rl_and_mask
);
4186 r_const
= const_binop (LSHIFT_EXPR
, r_const
, size_int (xrl_bitpos
), 0);
4187 if (! integer_zerop (const_binop (BIT_AND_EXPR
, r_const
,
4188 fold (build1 (BIT_NOT_EXPR
,
4192 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
4194 return convert (truth_type
,
4195 wanted_code
== NE_EXPR
4196 ? integer_one_node
: integer_zero_node
);
4200 /* If the right sides are not constant, do the same for it. Also,
4201 disallow this optimization if a size or signedness mismatch occurs
4202 between the left and right sides. */
4205 if (ll_bitsize
!= lr_bitsize
|| rl_bitsize
!= rr_bitsize
4206 || ll_unsignedp
!= lr_unsignedp
|| rl_unsignedp
!= rr_unsignedp
4207 /* Make sure the two fields on the right
4208 correspond to the left without being swapped. */
4209 || ll_bitpos
- rl_bitpos
!= lr_bitpos
- rr_bitpos
)
4212 first_bit
= MIN (lr_bitpos
, rr_bitpos
);
4213 end_bit
= MAX (lr_bitpos
+ lr_bitsize
, rr_bitpos
+ rr_bitsize
);
4214 rnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
4215 TYPE_ALIGN (TREE_TYPE (lr_inner
)), word_mode
,
4217 if (rnmode
== VOIDmode
)
4220 rnbitsize
= GET_MODE_BITSIZE (rnmode
);
4221 rnbitpos
= first_bit
& ~ (rnbitsize
- 1);
4222 rntype
= type_for_size (rnbitsize
, 1);
4223 xlr_bitpos
= lr_bitpos
- rnbitpos
, xrr_bitpos
= rr_bitpos
- rnbitpos
;
4225 if (BYTES_BIG_ENDIAN
)
4227 xlr_bitpos
= rnbitsize
- xlr_bitpos
- lr_bitsize
;
4228 xrr_bitpos
= rnbitsize
- xrr_bitpos
- rr_bitsize
;
4231 lr_mask
= const_binop (LSHIFT_EXPR
, convert (rntype
, lr_mask
),
4232 size_int (xlr_bitpos
), 0);
4233 rr_mask
= const_binop (LSHIFT_EXPR
, convert (rntype
, rr_mask
),
4234 size_int (xrr_bitpos
), 0);
4236 /* Make a mask that corresponds to both fields being compared.
4237 Do this for both items being compared. If the operands are the
4238 same size and the bits being compared are in the same position
4239 then we can do this by masking both and comparing the masked
4241 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
4242 lr_mask
= const_binop (BIT_IOR_EXPR
, lr_mask
, rr_mask
, 0);
4243 if (lnbitsize
== rnbitsize
&& xll_bitpos
== xlr_bitpos
)
4245 lhs
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
4246 ll_unsignedp
|| rl_unsignedp
);
4247 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
4248 lhs
= build (BIT_AND_EXPR
, lntype
, lhs
, ll_mask
);
4250 rhs
= make_bit_field_ref (lr_inner
, rntype
, rnbitsize
, rnbitpos
,
4251 lr_unsignedp
|| rr_unsignedp
);
4252 if (! all_ones_mask_p (lr_mask
, rnbitsize
))
4253 rhs
= build (BIT_AND_EXPR
, rntype
, rhs
, lr_mask
);
4255 return build (wanted_code
, truth_type
, lhs
, rhs
);
4258 /* There is still another way we can do something: If both pairs of
4259 fields being compared are adjacent, we may be able to make a wider
4260 field containing them both.
4262 Note that we still must mask the lhs/rhs expressions. Furthermore,
4263 the mask must be shifted to account for the shift done by
4264 make_bit_field_ref. */
4265 if ((ll_bitsize
+ ll_bitpos
== rl_bitpos
4266 && lr_bitsize
+ lr_bitpos
== rr_bitpos
)
4267 || (ll_bitpos
== rl_bitpos
+ rl_bitsize
4268 && lr_bitpos
== rr_bitpos
+ rr_bitsize
))
4272 lhs
= make_bit_field_ref (ll_inner
, lntype
, ll_bitsize
+ rl_bitsize
,
4273 MIN (ll_bitpos
, rl_bitpos
), ll_unsignedp
);
4274 rhs
= make_bit_field_ref (lr_inner
, rntype
, lr_bitsize
+ rr_bitsize
,
4275 MIN (lr_bitpos
, rr_bitpos
), lr_unsignedp
);
4277 ll_mask
= const_binop (RSHIFT_EXPR
, ll_mask
,
4278 size_int (MIN (xll_bitpos
, xrl_bitpos
)), 0);
4279 lr_mask
= const_binop (RSHIFT_EXPR
, lr_mask
,
4280 size_int (MIN (xlr_bitpos
, xrr_bitpos
)), 0);
4282 /* Convert to the smaller type before masking out unwanted bits. */
4284 if (lntype
!= rntype
)
4286 if (lnbitsize
> rnbitsize
)
4288 lhs
= convert (rntype
, lhs
);
4289 ll_mask
= convert (rntype
, ll_mask
);
4292 else if (lnbitsize
< rnbitsize
)
4294 rhs
= convert (lntype
, rhs
);
4295 lr_mask
= convert (lntype
, lr_mask
);
4300 if (! all_ones_mask_p (ll_mask
, ll_bitsize
+ rl_bitsize
))
4301 lhs
= build (BIT_AND_EXPR
, type
, lhs
, ll_mask
);
4303 if (! all_ones_mask_p (lr_mask
, lr_bitsize
+ rr_bitsize
))
4304 rhs
= build (BIT_AND_EXPR
, type
, rhs
, lr_mask
);
4306 return build (wanted_code
, truth_type
, lhs
, rhs
);
4312 /* Handle the case of comparisons with constants. If there is something in
4313 common between the masks, those bits of the constants must be the same.
4314 If not, the condition is always false. Test for this to avoid generating
4315 incorrect code below. */
4316 result
= const_binop (BIT_AND_EXPR
, ll_mask
, rl_mask
, 0);
4317 if (! integer_zerop (result
)
4318 && simple_cst_equal (const_binop (BIT_AND_EXPR
, result
, l_const
, 0),
4319 const_binop (BIT_AND_EXPR
, result
, r_const
, 0)) != 1)
4321 if (wanted_code
== NE_EXPR
)
4323 warning ("`or' of unmatched not-equal tests is always 1");
4324 return convert (truth_type
, integer_one_node
);
4328 warning ("`and' of mutually exclusive equal-tests is always 0");
4329 return convert (truth_type
, integer_zero_node
);
4333 /* Construct the expression we will return. First get the component
4334 reference we will make. Unless the mask is all ones the width of
4335 that field, perform the mask operation. Then compare with the
4337 result
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
4338 ll_unsignedp
|| rl_unsignedp
);
4340 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
4341 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
4342 result
= build (BIT_AND_EXPR
, lntype
, result
, ll_mask
);
4344 return build (wanted_code
, truth_type
, result
,
4345 const_binop (BIT_IOR_EXPR
, l_const
, r_const
, 0));
4348 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4352 optimize_minmax_comparison (t
)
4355 tree type
= TREE_TYPE (t
);
4356 tree arg0
= TREE_OPERAND (t
, 0);
4357 enum tree_code op_code
;
4358 tree comp_const
= TREE_OPERAND (t
, 1);
4360 int consts_equal
, consts_lt
;
4363 STRIP_SIGN_NOPS (arg0
);
4365 op_code
= TREE_CODE (arg0
);
4366 minmax_const
= TREE_OPERAND (arg0
, 1);
4367 consts_equal
= tree_int_cst_equal (minmax_const
, comp_const
);
4368 consts_lt
= tree_int_cst_lt (minmax_const
, comp_const
);
4369 inner
= TREE_OPERAND (arg0
, 0);
4371 /* If something does not permit us to optimize, return the original tree. */
4372 if ((op_code
!= MIN_EXPR
&& op_code
!= MAX_EXPR
)
4373 || TREE_CODE (comp_const
) != INTEGER_CST
4374 || TREE_CONSTANT_OVERFLOW (comp_const
)
4375 || TREE_CODE (minmax_const
) != INTEGER_CST
4376 || TREE_CONSTANT_OVERFLOW (minmax_const
))
4379 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4380 and GT_EXPR, doing the rest with recursive calls using logical
4382 switch (TREE_CODE (t
))
4384 case NE_EXPR
: case LT_EXPR
: case LE_EXPR
:
4386 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t
)));
4390 fold (build (TRUTH_ORIF_EXPR
, type
,
4391 optimize_minmax_comparison
4392 (build (EQ_EXPR
, type
, arg0
, comp_const
)),
4393 optimize_minmax_comparison
4394 (build (GT_EXPR
, type
, arg0
, comp_const
))));
4397 if (op_code
== MAX_EXPR
&& consts_equal
)
4398 /* MAX (X, 0) == 0 -> X <= 0 */
4399 return fold (build (LE_EXPR
, type
, inner
, comp_const
));
4401 else if (op_code
== MAX_EXPR
&& consts_lt
)
4402 /* MAX (X, 0) == 5 -> X == 5 */
4403 return fold (build (EQ_EXPR
, type
, inner
, comp_const
));
4405 else if (op_code
== MAX_EXPR
)
4406 /* MAX (X, 0) == -1 -> false */
4407 return omit_one_operand (type
, integer_zero_node
, inner
);
4409 else if (consts_equal
)
4410 /* MIN (X, 0) == 0 -> X >= 0 */
4411 return fold (build (GE_EXPR
, type
, inner
, comp_const
));
4414 /* MIN (X, 0) == 5 -> false */
4415 return omit_one_operand (type
, integer_zero_node
, inner
);
4418 /* MIN (X, 0) == -1 -> X == -1 */
4419 return fold (build (EQ_EXPR
, type
, inner
, comp_const
));
4422 if (op_code
== MAX_EXPR
&& (consts_equal
|| consts_lt
))
4423 /* MAX (X, 0) > 0 -> X > 0
4424 MAX (X, 0) > 5 -> X > 5 */
4425 return fold (build (GT_EXPR
, type
, inner
, comp_const
));
4427 else if (op_code
== MAX_EXPR
)
4428 /* MAX (X, 0) > -1 -> true */
4429 return omit_one_operand (type
, integer_one_node
, inner
);
4431 else if (op_code
== MIN_EXPR
&& (consts_equal
|| consts_lt
))
4432 /* MIN (X, 0) > 0 -> false
4433 MIN (X, 0) > 5 -> false */
4434 return omit_one_operand (type
, integer_zero_node
, inner
);
4437 /* MIN (X, 0) > -1 -> X > -1 */
4438 return fold (build (GT_EXPR
, type
, inner
, comp_const
));
4445 /* T is an integer expression that is being multiplied, divided, or taken a
4446 modulus (CODE says which and what kind of divide or modulus) by a
4447 constant C. See if we can eliminate that operation by folding it with
4448 other operations already in T. WIDE_TYPE, if non-null, is a type that
4449 should be used for the computation if wider than our type.
4451 For example, if we are dividing (X * 8) + (Y + 16) by 4, we can return
4452 (X * 2) + (Y + 4). We must, however, be assured that either the original
4453 expression would not overflow or that overflow is undefined for the type
4454 in the language in question.
4456 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4457 the machine has a multiply-accumulate insn or that this is part of an
4458 addressing calculation.
4460 If we return a non-null expression, it is an equivalent form of the
4461 original computation, but need not be in the original type. */
4464 extract_muldiv (t
, c
, code
, wide_type
)
4467 enum tree_code code
;
4470 tree type
= TREE_TYPE (t
);
4471 enum tree_code tcode
= TREE_CODE (t
);
4472 tree ctype
= (wide_type
!= 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type
))
4473 > GET_MODE_SIZE (TYPE_MODE (type
)))
4474 ? wide_type
: type
);
4476 int same_p
= tcode
== code
;
4477 tree op0
= NULL_TREE
, op1
= NULL_TREE
;
4479 /* Don't deal with constants of zero here; they confuse the code below. */
4480 if (integer_zerop (c
))
4483 if (TREE_CODE_CLASS (tcode
) == '1')
4484 op0
= TREE_OPERAND (t
, 0);
4486 if (TREE_CODE_CLASS (tcode
) == '2')
4487 op0
= TREE_OPERAND (t
, 0), op1
= TREE_OPERAND (t
, 1);
4489 /* Note that we need not handle conditional operations here since fold
4490 already handles those cases. So just do arithmetic here. */
4494 /* For a constant, we can always simplify if we are a multiply
4495 or (for divide and modulus) if it is a multiple of our constant. */
4496 if (code
== MULT_EXPR
4497 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, t
, c
, 0)))
4498 return const_binop (code
, convert (ctype
, t
), convert (ctype
, c
), 0);
4501 case CONVERT_EXPR
: case NON_LVALUE_EXPR
: case NOP_EXPR
:
4502 /* If op0 is an expression, and is unsigned, and the type is
4503 smaller than ctype, then we cannot widen the expression. */
4504 if ((TREE_CODE_CLASS (TREE_CODE (op0
)) == '<'
4505 || TREE_CODE_CLASS (TREE_CODE (op0
)) == '1'
4506 || TREE_CODE_CLASS (TREE_CODE (op0
)) == '2'
4507 || TREE_CODE_CLASS (TREE_CODE (op0
)) == 'e')
4508 && TREE_UNSIGNED (TREE_TYPE (op0
))
4509 && ! (TREE_CODE (TREE_TYPE (op0
)) == INTEGER_TYPE
4510 && TYPE_IS_SIZETYPE (TREE_TYPE (op0
)))
4511 && (GET_MODE_SIZE (TYPE_MODE (ctype
))
4512 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
)))))
4515 /* Pass the constant down and see if we can make a simplification. If
4516 we can, replace this expression with the inner simplification for
4517 possible later conversion to our or some other type. */
4518 if (0 != (t1
= extract_muldiv (op0
, convert (TREE_TYPE (op0
), c
), code
,
4519 code
== MULT_EXPR
? ctype
: NULL_TREE
)))
4523 case NEGATE_EXPR
: case ABS_EXPR
:
4524 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
4525 return fold (build1 (tcode
, ctype
, convert (ctype
, t1
)));
4528 case MIN_EXPR
: case MAX_EXPR
:
4529 /* If widening the type changes the signedness, then we can't perform
4530 this optimization as that changes the result. */
4531 if (TREE_UNSIGNED (ctype
) != TREE_UNSIGNED (type
))
4534 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4535 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0
4536 && (t2
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
4538 if (tree_int_cst_sgn (c
) < 0)
4539 tcode
= (tcode
== MIN_EXPR
? MAX_EXPR
: MIN_EXPR
);
4541 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4542 convert (ctype
, t2
)));
4546 case WITH_RECORD_EXPR
:
4547 if ((t1
= extract_muldiv (TREE_OPERAND (t
, 0), c
, code
, wide_type
)) != 0)
4548 return build (WITH_RECORD_EXPR
, TREE_TYPE (t1
), t1
,
4549 TREE_OPERAND (t
, 1));
4553 /* If this has not been evaluated and the operand has no side effects,
4554 we can see if we can do something inside it and make a new one.
4555 Note that this test is overly conservative since we can do this
4556 if the only reason it had side effects is that it was another
4557 similar SAVE_EXPR, but that isn't worth bothering with. */
4558 if (SAVE_EXPR_RTL (t
) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 0))
4559 && 0 != (t1
= extract_muldiv (TREE_OPERAND (t
, 0), c
, code
,
4562 t1
= save_expr (t1
);
4563 if (SAVE_EXPR_PERSISTENT_P (t
) && TREE_CODE (t1
) == SAVE_EXPR
)
4564 SAVE_EXPR_PERSISTENT_P (t1
) = 1;
4565 if (is_pending_size (t
))
4566 put_pending_size (t1
);
4571 case LSHIFT_EXPR
: case RSHIFT_EXPR
:
4572 /* If the second operand is constant, this is a multiplication
4573 or floor division, by a power of two, so we can treat it that
4574 way unless the multiplier or divisor overflows. */
4575 if (TREE_CODE (op1
) == INTEGER_CST
4576 /* const_binop may not detect overflow correctly,
4577 so check for it explicitly here. */
4578 && TYPE_PRECISION (TREE_TYPE (size_one_node
)) > TREE_INT_CST_LOW (op1
)
4579 && TREE_INT_CST_HIGH (op1
) == 0
4580 && 0 != (t1
= convert (ctype
,
4581 const_binop (LSHIFT_EXPR
, size_one_node
,
4583 && ! TREE_OVERFLOW (t1
))
4584 return extract_muldiv (build (tcode
== LSHIFT_EXPR
4585 ? MULT_EXPR
: FLOOR_DIV_EXPR
,
4586 ctype
, convert (ctype
, op0
), t1
),
4587 c
, code
, wide_type
);
4590 case PLUS_EXPR
: case MINUS_EXPR
:
4591 /* See if we can eliminate the operation on both sides. If we can, we
4592 can return a new PLUS or MINUS. If we can't, the only remaining
4593 cases where we can do anything are if the second operand is a
4595 t1
= extract_muldiv (op0
, c
, code
, wide_type
);
4596 t2
= extract_muldiv (op1
, c
, code
, wide_type
);
4597 if (t1
!= 0 && t2
!= 0
4598 && (code
== MULT_EXPR
4599 /* If not multiplication, we can only do this if either operand
4600 is divisible by c. */
4601 || multiple_of_p (ctype
, op0
, c
)
4602 || multiple_of_p (ctype
, op1
, c
)))
4603 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4604 convert (ctype
, t2
)));
4606 /* If this was a subtraction, negate OP1 and set it to be an addition.
4607 This simplifies the logic below. */
4608 if (tcode
== MINUS_EXPR
)
4609 tcode
= PLUS_EXPR
, op1
= negate_expr (op1
);
4611 if (TREE_CODE (op1
) != INTEGER_CST
)
4614 /* If either OP1 or C are negative, this optimization is not safe for
4615 some of the division and remainder types while for others we need
4616 to change the code. */
4617 if (tree_int_cst_sgn (op1
) < 0 || tree_int_cst_sgn (c
) < 0)
4619 if (code
== CEIL_DIV_EXPR
)
4620 code
= FLOOR_DIV_EXPR
;
4621 else if (code
== FLOOR_DIV_EXPR
)
4622 code
= CEIL_DIV_EXPR
;
4623 else if (code
!= MULT_EXPR
4624 && code
!= CEIL_MOD_EXPR
&& code
!= FLOOR_MOD_EXPR
)
4628 /* If it's a multiply or a division/modulus operation of a multiple
4629 of our constant, do the operation and verify it doesn't overflow. */
4630 if (code
== MULT_EXPR
4631 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4633 op1
= const_binop (code
, convert (ctype
, op1
), convert (ctype
, c
), 0);
4634 if (op1
== 0 || TREE_OVERFLOW (op1
))
4640 /* If we have an unsigned type is not a sizetype, we cannot widen
4641 the operation since it will change the result if the original
4642 computation overflowed. */
4643 if (TREE_UNSIGNED (ctype
)
4644 && ! (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
))
4648 /* If we were able to eliminate our operation from the first side,
4649 apply our operation to the second side and reform the PLUS. */
4650 if (t1
!= 0 && (TREE_CODE (t1
) != code
|| code
== MULT_EXPR
))
4651 return fold (build (tcode
, ctype
, convert (ctype
, t1
), op1
));
4653 /* The last case is if we are a multiply. In that case, we can
4654 apply the distributive law to commute the multiply and addition
4655 if the multiplication of the constants doesn't overflow. */
4656 if (code
== MULT_EXPR
)
4657 return fold (build (tcode
, ctype
, fold (build (code
, ctype
,
4658 convert (ctype
, op0
),
4659 convert (ctype
, c
))),
4665 /* We have a special case here if we are doing something like
4666 (C * 8) % 4 since we know that's zero. */
4667 if ((code
== TRUNC_MOD_EXPR
|| code
== CEIL_MOD_EXPR
4668 || code
== FLOOR_MOD_EXPR
|| code
== ROUND_MOD_EXPR
)
4669 && TREE_CODE (TREE_OPERAND (t
, 1)) == INTEGER_CST
4670 && integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4671 return omit_one_operand (type
, integer_zero_node
, op0
);
4673 /* ... fall through ... */
4675 case TRUNC_DIV_EXPR
: case CEIL_DIV_EXPR
: case FLOOR_DIV_EXPR
:
4676 case ROUND_DIV_EXPR
: case EXACT_DIV_EXPR
:
4677 /* If we can extract our operation from the LHS, do so and return a
4678 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4679 do something only if the second operand is a constant. */
4681 && (t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
4682 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4683 convert (ctype
, op1
)));
4684 else if (tcode
== MULT_EXPR
&& code
== MULT_EXPR
4685 && (t1
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
4686 return fold (build (tcode
, ctype
, convert (ctype
, op0
),
4687 convert (ctype
, t1
)));
4688 else if (TREE_CODE (op1
) != INTEGER_CST
)
4691 /* If these are the same operation types, we can associate them
4692 assuming no overflow. */
4694 && 0 != (t1
= const_binop (MULT_EXPR
, convert (ctype
, op1
),
4695 convert (ctype
, c
), 0))
4696 && ! TREE_OVERFLOW (t1
))
4697 return fold (build (tcode
, ctype
, convert (ctype
, op0
), t1
));
4699 /* If these operations "cancel" each other, we have the main
4700 optimizations of this pass, which occur when either constant is a
4701 multiple of the other, in which case we replace this with either an
4702 operation or CODE or TCODE.
4704 If we have an unsigned type that is not a sizetype, we cannot do
4705 this since it will change the result if the original computation
4707 if ((! TREE_UNSIGNED (ctype
)
4708 || (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
)))
4709 && ((code
== MULT_EXPR
&& tcode
== EXACT_DIV_EXPR
)
4710 || (tcode
== MULT_EXPR
4711 && code
!= TRUNC_MOD_EXPR
&& code
!= CEIL_MOD_EXPR
4712 && code
!= FLOOR_MOD_EXPR
&& code
!= ROUND_MOD_EXPR
)))
4714 if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4715 return fold (build (tcode
, ctype
, convert (ctype
, op0
),
4717 const_binop (TRUNC_DIV_EXPR
,
4719 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, c
, op1
, 0)))
4720 return fold (build (code
, ctype
, convert (ctype
, op0
),
4722 const_binop (TRUNC_DIV_EXPR
,
4734 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4735 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4736 that we may sometimes modify the tree. */
4739 strip_compound_expr (t
, s
)
4743 enum tree_code code
= TREE_CODE (t
);
4745 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4746 if (code
== COMPOUND_EXPR
&& TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
4747 && TREE_OPERAND (TREE_OPERAND (t
, 0), 0) == s
)
4748 return TREE_OPERAND (t
, 1);
4750 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4751 don't bother handling any other types. */
4752 else if (code
== COND_EXPR
)
4754 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4755 TREE_OPERAND (t
, 1) = strip_compound_expr (TREE_OPERAND (t
, 1), s
);
4756 TREE_OPERAND (t
, 2) = strip_compound_expr (TREE_OPERAND (t
, 2), s
);
4758 else if (TREE_CODE_CLASS (code
) == '1')
4759 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4760 else if (TREE_CODE_CLASS (code
) == '<'
4761 || TREE_CODE_CLASS (code
) == '2')
4763 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4764 TREE_OPERAND (t
, 1) = strip_compound_expr (TREE_OPERAND (t
, 1), s
);
4770 /* Return a node which has the indicated constant VALUE (either 0 or
4771 1), and is of the indicated TYPE. */
4774 constant_boolean_node (value
, type
)
4778 if (type
== integer_type_node
)
4779 return value
? integer_one_node
: integer_zero_node
;
4780 else if (TREE_CODE (type
) == BOOLEAN_TYPE
)
4781 return truthvalue_conversion (value
? integer_one_node
:
4785 tree t
= build_int_2 (value
, 0);
4787 TREE_TYPE (t
) = type
;
4792 /* Utility function for the following routine, to see how complex a nesting of
4793 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4794 we don't care (to avoid spending too much time on complex expressions.). */
4797 count_cond (expr
, lim
)
4803 if (TREE_CODE (expr
) != COND_EXPR
)
4808 ctrue
= count_cond (TREE_OPERAND (expr
, 1), lim
- 1);
4809 cfalse
= count_cond (TREE_OPERAND (expr
, 2), lim
- 1 - ctrue
);
4810 return MIN (lim
, 1 + ctrue
+ cfalse
);
4813 /* Transform `a + (b ? x : y)' into `x ? (a + b) : (a + y)'.
4814 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4815 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4816 expression, and ARG to `a'. If COND_FIRST_P is non-zero, then the
4817 COND is the first argument to CODE; otherwise (as in the example
4818 given here), it is the second argument. TYPE is the type of the
4819 original expression. */
4822 fold_binary_op_with_conditional_arg (code
, type
, cond
, arg
, cond_first_p
)
4823 enum tree_code code
;
4829 tree test
, true_value
, false_value
;
4830 tree lhs
= NULL_TREE
;
4831 tree rhs
= NULL_TREE
;
4832 /* In the end, we'll produce a COND_EXPR. Both arms of the
4833 conditional expression will be binary operations. The left-hand
4834 side of the expression to be executed if the condition is true
4835 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4836 of the expression to be executed if the condition is true will be
4837 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4838 but apply to the expression to be executed if the conditional is
4844 /* These are the codes to use for the left-hand side and right-hand
4845 side of the COND_EXPR. Normally, they are the same as CODE. */
4846 enum tree_code lhs_code
= code
;
4847 enum tree_code rhs_code
= code
;
4848 /* And these are the types of the expressions. */
4849 tree lhs_type
= type
;
4850 tree rhs_type
= type
;
4854 true_rhs
= false_rhs
= &arg
;
4855 true_lhs
= &true_value
;
4856 false_lhs
= &false_value
;
4860 true_lhs
= false_lhs
= &arg
;
4861 true_rhs
= &true_value
;
4862 false_rhs
= &false_value
;
4865 if (TREE_CODE (cond
) == COND_EXPR
)
4867 test
= TREE_OPERAND (cond
, 0);
4868 true_value
= TREE_OPERAND (cond
, 1);
4869 false_value
= TREE_OPERAND (cond
, 2);
4870 /* If this operand throws an expression, then it does not make
4871 sense to try to perform a logical or arithmetic operation
4872 involving it. Instead of building `a + throw 3' for example,
4873 we simply build `a, throw 3'. */
4874 if (VOID_TYPE_P (TREE_TYPE (true_value
)))
4876 lhs_code
= COMPOUND_EXPR
;
4878 lhs_type
= void_type_node
;
4880 if (VOID_TYPE_P (TREE_TYPE (false_value
)))
4882 rhs_code
= COMPOUND_EXPR
;
4884 rhs_type
= void_type_node
;
4889 tree testtype
= TREE_TYPE (cond
);
4891 true_value
= convert (testtype
, integer_one_node
);
4892 false_value
= convert (testtype
, integer_zero_node
);
4895 /* If ARG is complex we want to make sure we only evaluate
4896 it once. Though this is only required if it is volatile, it
4897 might be more efficient even if it is not. However, if we
4898 succeed in folding one part to a constant, we do not need
4899 to make this SAVE_EXPR. Since we do this optimization
4900 primarily to see if we do end up with constant and this
4901 SAVE_EXPR interferes with later optimizations, suppressing
4902 it when we can is important.
4904 If we are not in a function, we can't make a SAVE_EXPR, so don't
4905 try to do so. Don't try to see if the result is a constant
4906 if an arm is a COND_EXPR since we get exponential behavior
4909 if (TREE_CODE (arg
) != SAVE_EXPR
&& ! TREE_CONSTANT (arg
)
4910 && global_bindings_p () == 0
4911 && ((TREE_CODE (arg
) != VAR_DECL
4912 && TREE_CODE (arg
) != PARM_DECL
)
4913 || TREE_SIDE_EFFECTS (arg
)))
4915 if (TREE_CODE (true_value
) != COND_EXPR
)
4916 lhs
= fold (build (lhs_code
, lhs_type
, *true_lhs
, *true_rhs
));
4918 if (TREE_CODE (false_value
) != COND_EXPR
)
4919 rhs
= fold (build (rhs_code
, rhs_type
, *false_lhs
, *false_rhs
));
4921 if ((lhs
== 0 || ! TREE_CONSTANT (lhs
))
4922 && (rhs
== 0 || !TREE_CONSTANT (rhs
)))
4923 arg
= save_expr (arg
), lhs
= rhs
= 0;
4927 lhs
= fold (build (lhs_code
, lhs_type
, *true_lhs
, *true_rhs
));
4929 rhs
= fold (build (rhs_code
, rhs_type
, *false_lhs
, *false_rhs
));
4931 test
= fold (build (COND_EXPR
, type
, test
, lhs
, rhs
));
4933 if (TREE_CODE (arg
) == SAVE_EXPR
)
4934 return build (COMPOUND_EXPR
, type
,
4935 convert (void_type_node
, arg
),
4936 strip_compound_expr (test
, arg
));
4938 return convert (type
, test
);
4942 /* Perform constant folding and related simplification of EXPR.
4943 The related simplifications include x*1 => x, x*0 => 0, etc.,
4944 and application of the associative law.
4945 NOP_EXPR conversions may be removed freely (as long as we
4946 are careful not to change the C type of the overall expression)
4947 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4948 but we can constant-fold them if they have constant operands. */
4955 tree t1
= NULL_TREE
;
4957 tree type
= TREE_TYPE (expr
);
4958 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
;
4959 enum tree_code code
= TREE_CODE (t
);
4960 int kind
= TREE_CODE_CLASS (code
);
4962 /* WINS will be nonzero when the switch is done
4963 if all operands are constant. */
4966 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4967 Likewise for a SAVE_EXPR that's already been evaluated. */
4968 if (code
== RTL_EXPR
|| (code
== SAVE_EXPR
&& SAVE_EXPR_RTL (t
) != 0))
4971 /* Return right away if a constant. */
4975 #ifdef MAX_INTEGER_COMPUTATION_MODE
4976 check_max_integer_computation_mode (expr
);
4979 if (code
== NOP_EXPR
|| code
== FLOAT_EXPR
|| code
== CONVERT_EXPR
)
4983 /* Special case for conversion ops that can have fixed point args. */
4984 arg0
= TREE_OPERAND (t
, 0);
4986 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4988 STRIP_SIGN_NOPS (arg0
);
4990 if (arg0
!= 0 && TREE_CODE (arg0
) == COMPLEX_CST
)
4991 subop
= TREE_REALPART (arg0
);
4995 if (subop
!= 0 && TREE_CODE (subop
) != INTEGER_CST
4996 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4997 && TREE_CODE (subop
) != REAL_CST
4998 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5000 /* Note that TREE_CONSTANT isn't enough:
5001 static var addresses are constant but we can't
5002 do arithmetic on them. */
5005 else if (IS_EXPR_CODE_CLASS (kind
) || kind
== 'r')
5007 int len
= first_rtl_op (code
);
5009 for (i
= 0; i
< len
; i
++)
5011 tree op
= TREE_OPERAND (t
, i
);
5015 continue; /* Valid for CALL_EXPR, at least. */
5017 if (kind
== '<' || code
== RSHIFT_EXPR
)
5019 /* Signedness matters here. Perhaps we can refine this
5021 STRIP_SIGN_NOPS (op
);
5024 /* Strip any conversions that don't change the mode. */
5027 if (TREE_CODE (op
) == COMPLEX_CST
)
5028 subop
= TREE_REALPART (op
);
5032 if (TREE_CODE (subop
) != INTEGER_CST
5033 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5034 && TREE_CODE (subop
) != REAL_CST
5035 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5037 /* Note that TREE_CONSTANT isn't enough:
5038 static var addresses are constant but we can't
5039 do arithmetic on them. */
5049 /* If this is a commutative operation, and ARG0 is a constant, move it
5050 to ARG1 to reduce the number of tests below. */
5051 if ((code
== PLUS_EXPR
|| code
== MULT_EXPR
|| code
== MIN_EXPR
5052 || code
== MAX_EXPR
|| code
== BIT_IOR_EXPR
|| code
== BIT_XOR_EXPR
5053 || code
== BIT_AND_EXPR
)
5054 && (TREE_CODE (arg0
) == INTEGER_CST
|| TREE_CODE (arg0
) == REAL_CST
))
5056 tem
= arg0
; arg0
= arg1
; arg1
= tem
;
5058 tem
= TREE_OPERAND (t
, 0); TREE_OPERAND (t
, 0) = TREE_OPERAND (t
, 1);
5059 TREE_OPERAND (t
, 1) = tem
;
5062 /* Now WINS is set as described above,
5063 ARG0 is the first operand of EXPR,
5064 and ARG1 is the second operand (if it has more than one operand).
5066 First check for cases where an arithmetic operation is applied to a
5067 compound, conditional, or comparison operation. Push the arithmetic
5068 operation inside the compound or conditional to see if any folding
5069 can then be done. Convert comparison to conditional for this purpose.
5070 The also optimizes non-constant cases that used to be done in
5073 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
5074 one of the operands is a comparison and the other is a comparison, a
5075 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
5076 code below would make the expression more complex. Change it to a
5077 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
5078 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
5080 if ((code
== BIT_AND_EXPR
|| code
== BIT_IOR_EXPR
5081 || code
== EQ_EXPR
|| code
== NE_EXPR
)
5082 && ((truth_value_p (TREE_CODE (arg0
))
5083 && (truth_value_p (TREE_CODE (arg1
))
5084 || (TREE_CODE (arg1
) == BIT_AND_EXPR
5085 && integer_onep (TREE_OPERAND (arg1
, 1)))))
5086 || (truth_value_p (TREE_CODE (arg1
))
5087 && (truth_value_p (TREE_CODE (arg0
))
5088 || (TREE_CODE (arg0
) == BIT_AND_EXPR
5089 && integer_onep (TREE_OPERAND (arg0
, 1)))))))
5091 t
= fold (build (code
== BIT_AND_EXPR
? TRUTH_AND_EXPR
5092 : code
== BIT_IOR_EXPR
? TRUTH_OR_EXPR
5096 if (code
== EQ_EXPR
)
5097 t
= invert_truthvalue (t
);
5102 if (TREE_CODE_CLASS (code
) == '1')
5104 if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
5105 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5106 fold (build1 (code
, type
, TREE_OPERAND (arg0
, 1))));
5107 else if (TREE_CODE (arg0
) == COND_EXPR
)
5109 t
= fold (build (COND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5110 fold (build1 (code
, type
, TREE_OPERAND (arg0
, 1))),
5111 fold (build1 (code
, type
, TREE_OPERAND (arg0
, 2)))));
5113 /* If this was a conversion, and all we did was to move into
5114 inside the COND_EXPR, bring it back out. But leave it if
5115 it is a conversion from integer to integer and the
5116 result precision is no wider than a word since such a
5117 conversion is cheap and may be optimized away by combine,
5118 while it couldn't if it were outside the COND_EXPR. Then return
5119 so we don't get into an infinite recursion loop taking the
5120 conversion out and then back in. */
5122 if ((code
== NOP_EXPR
|| code
== CONVERT_EXPR
5123 || code
== NON_LVALUE_EXPR
)
5124 && TREE_CODE (t
) == COND_EXPR
5125 && TREE_CODE (TREE_OPERAND (t
, 1)) == code
5126 && TREE_CODE (TREE_OPERAND (t
, 2)) == code
5127 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0))
5128 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 2), 0)))
5129 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t
))
5131 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0))))
5132 && TYPE_PRECISION (TREE_TYPE (t
)) <= BITS_PER_WORD
))
5133 t
= build1 (code
, type
,
5135 TREE_TYPE (TREE_OPERAND
5136 (TREE_OPERAND (t
, 1), 0)),
5137 TREE_OPERAND (t
, 0),
5138 TREE_OPERAND (TREE_OPERAND (t
, 1), 0),
5139 TREE_OPERAND (TREE_OPERAND (t
, 2), 0)));
5142 else if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<')
5143 return fold (build (COND_EXPR
, type
, arg0
,
5144 fold (build1 (code
, type
, integer_one_node
)),
5145 fold (build1 (code
, type
, integer_zero_node
))));
5147 else if (TREE_CODE_CLASS (code
) == '2'
5148 || TREE_CODE_CLASS (code
) == '<')
5150 if (TREE_CODE (arg1
) == COMPOUND_EXPR
)
5151 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
5152 fold (build (code
, type
,
5153 arg0
, TREE_OPERAND (arg1
, 1))));
5154 else if ((TREE_CODE (arg1
) == COND_EXPR
5155 || (TREE_CODE_CLASS (TREE_CODE (arg1
)) == '<'
5156 && TREE_CODE_CLASS (code
) != '<'))
5157 && (TREE_CODE (arg0
) != COND_EXPR
5158 || count_cond (arg0
, 25) + count_cond (arg1
, 25) <= 25)
5159 && (! TREE_SIDE_EFFECTS (arg0
)
5160 || (global_bindings_p () == 0
5161 && ! contains_placeholder_p (arg0
))))
5163 fold_binary_op_with_conditional_arg (code
, type
, arg1
, arg0
,
5164 /*cond_first_p=*/0);
5165 else if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
5166 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5167 fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
5168 else if ((TREE_CODE (arg0
) == COND_EXPR
5169 || (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
5170 && TREE_CODE_CLASS (code
) != '<'))
5171 && (TREE_CODE (arg1
) != COND_EXPR
5172 || count_cond (arg0
, 25) + count_cond (arg1
, 25) <= 25)
5173 && (! TREE_SIDE_EFFECTS (arg1
)
5174 || (global_bindings_p () == 0
5175 && ! contains_placeholder_p (arg1
))))
5177 fold_binary_op_with_conditional_arg (code
, type
, arg0
, arg1
,
5178 /*cond_first_p=*/1);
5180 else if (TREE_CODE_CLASS (code
) == '<'
5181 && TREE_CODE (arg0
) == COMPOUND_EXPR
)
5182 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5183 fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
5184 else if (TREE_CODE_CLASS (code
) == '<'
5185 && TREE_CODE (arg1
) == COMPOUND_EXPR
)
5186 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
5187 fold (build (code
, type
, arg0
, TREE_OPERAND (arg1
, 1))));
5199 return fold (DECL_INITIAL (t
));
5204 case FIX_TRUNC_EXPR
:
5205 /* Other kinds of FIX are not handled properly by fold_convert. */
5207 if (TREE_TYPE (TREE_OPERAND (t
, 0)) == TREE_TYPE (t
))
5208 return TREE_OPERAND (t
, 0);
5210 /* Handle cases of two conversions in a row. */
5211 if (TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
5212 || TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
)
5214 tree inside_type
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5215 tree inter_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
5216 tree final_type
= TREE_TYPE (t
);
5217 int inside_int
= INTEGRAL_TYPE_P (inside_type
);
5218 int inside_ptr
= POINTER_TYPE_P (inside_type
);
5219 int inside_float
= FLOAT_TYPE_P (inside_type
);
5220 unsigned int inside_prec
= TYPE_PRECISION (inside_type
);
5221 int inside_unsignedp
= TREE_UNSIGNED (inside_type
);
5222 int inter_int
= INTEGRAL_TYPE_P (inter_type
);
5223 int inter_ptr
= POINTER_TYPE_P (inter_type
);
5224 int inter_float
= FLOAT_TYPE_P (inter_type
);
5225 unsigned int inter_prec
= TYPE_PRECISION (inter_type
);
5226 int inter_unsignedp
= TREE_UNSIGNED (inter_type
);
5227 int final_int
= INTEGRAL_TYPE_P (final_type
);
5228 int final_ptr
= POINTER_TYPE_P (final_type
);
5229 int final_float
= FLOAT_TYPE_P (final_type
);
5230 unsigned int final_prec
= TYPE_PRECISION (final_type
);
5231 int final_unsignedp
= TREE_UNSIGNED (final_type
);
5233 /* In addition to the cases of two conversions in a row
5234 handled below, if we are converting something to its own
5235 type via an object of identical or wider precision, neither
5236 conversion is needed. */
5237 if (TYPE_MAIN_VARIANT (inside_type
) == TYPE_MAIN_VARIANT (final_type
)
5238 && ((inter_int
&& final_int
) || (inter_float
&& final_float
))
5239 && inter_prec
>= final_prec
)
5240 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5242 /* Likewise, if the intermediate and final types are either both
5243 float or both integer, we don't need the middle conversion if
5244 it is wider than the final type and doesn't change the signedness
5245 (for integers). Avoid this if the final type is a pointer
5246 since then we sometimes need the inner conversion. Likewise if
5247 the outer has a precision not equal to the size of its mode. */
5248 if ((((inter_int
|| inter_ptr
) && (inside_int
|| inside_ptr
))
5249 || (inter_float
&& inside_float
))
5250 && inter_prec
>= inside_prec
5251 && (inter_float
|| inter_unsignedp
== inside_unsignedp
)
5252 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (final_type
))
5253 && TYPE_MODE (final_type
) == TYPE_MODE (inter_type
))
5255 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5257 /* If we have a sign-extension of a zero-extended value, we can
5258 replace that by a single zero-extension. */
5259 if (inside_int
&& inter_int
&& final_int
5260 && inside_prec
< inter_prec
&& inter_prec
< final_prec
5261 && inside_unsignedp
&& !inter_unsignedp
)
5262 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5264 /* Two conversions in a row are not needed unless:
5265 - some conversion is floating-point (overstrict for now), or
5266 - the intermediate type is narrower than both initial and
5268 - the intermediate type and innermost type differ in signedness,
5269 and the outermost type is wider than the intermediate, or
5270 - the initial type is a pointer type and the precisions of the
5271 intermediate and final types differ, or
5272 - the final type is a pointer type and the precisions of the
5273 initial and intermediate types differ. */
5274 if (! inside_float
&& ! inter_float
&& ! final_float
5275 && (inter_prec
> inside_prec
|| inter_prec
> final_prec
)
5276 && ! (inside_int
&& inter_int
5277 && inter_unsignedp
!= inside_unsignedp
5278 && inter_prec
< final_prec
)
5279 && ((inter_unsignedp
&& inter_prec
> inside_prec
)
5280 == (final_unsignedp
&& final_prec
> inter_prec
))
5281 && ! (inside_ptr
&& inter_prec
!= final_prec
)
5282 && ! (final_ptr
&& inside_prec
!= inter_prec
)
5283 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (final_type
))
5284 && TYPE_MODE (final_type
) == TYPE_MODE (inter_type
))
5286 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5289 if (TREE_CODE (TREE_OPERAND (t
, 0)) == MODIFY_EXPR
5290 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t
, 0), 1))
5291 /* Detect assigning a bitfield. */
5292 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0)) == COMPONENT_REF
5293 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t
, 0), 0), 1))))
5295 /* Don't leave an assignment inside a conversion
5296 unless assigning a bitfield. */
5297 tree prev
= TREE_OPERAND (t
, 0);
5298 TREE_OPERAND (t
, 0) = TREE_OPERAND (prev
, 1);
5299 /* First do the assignment, then return converted constant. */
5300 t
= build (COMPOUND_EXPR
, TREE_TYPE (t
), prev
, fold (t
));
5306 TREE_CONSTANT (t
) = TREE_CONSTANT (arg0
);
5309 return fold_convert (t
, arg0
);
5311 case VIEW_CONVERT_EXPR
:
5312 if (TREE_CODE (TREE_OPERAND (t
, 0)) == VIEW_CONVERT_EXPR
)
5313 return build1 (VIEW_CONVERT_EXPR
, type
,
5314 TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5317 #if 0 /* This loses on &"foo"[0]. */
5322 /* Fold an expression like: "foo"[2] */
5323 if (TREE_CODE (arg0
) == STRING_CST
5324 && TREE_CODE (arg1
) == INTEGER_CST
5325 && compare_tree_int (arg1
, TREE_STRING_LENGTH (arg0
)) < 0)
5327 t
= build_int_2 (TREE_STRING_POINTER (arg0
)[TREE_INT_CST_LOW (arg
))], 0);
5328 TREE_TYPE (t
) = TREE_TYPE (TREE_TYPE (arg0
));
5329 force_fit_type (t
, 0);
5336 if (TREE_CODE (arg0
) == CONSTRUCTOR
)
5338 tree m
= purpose_member (arg1
, CONSTRUCTOR_ELTS (arg0
));
5345 TREE_CONSTANT (t
) = wins
;
5351 if (TREE_CODE (arg0
) == INTEGER_CST
)
5353 unsigned HOST_WIDE_INT low
;
5355 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
5356 TREE_INT_CST_HIGH (arg0
),
5358 t
= build_int_2 (low
, high
);
5359 TREE_TYPE (t
) = type
;
5361 = (TREE_OVERFLOW (arg0
)
5362 | force_fit_type (t
, overflow
&& !TREE_UNSIGNED (type
)));
5363 TREE_CONSTANT_OVERFLOW (t
)
5364 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg0
);
5366 else if (TREE_CODE (arg0
) == REAL_CST
)
5367 t
= build_real (type
, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
5369 else if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5370 return TREE_OPERAND (arg0
, 0);
5372 /* Convert - (a - b) to (b - a) for non-floating-point. */
5373 else if (TREE_CODE (arg0
) == MINUS_EXPR
5374 && (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
))
5375 return build (MINUS_EXPR
, type
, TREE_OPERAND (arg0
, 1),
5376 TREE_OPERAND (arg0
, 0));
5383 if (TREE_CODE (arg0
) == INTEGER_CST
)
5385 /* If the value is unsigned, then the absolute value is
5386 the same as the ordinary value. */
5387 if (TREE_UNSIGNED (type
))
5389 /* Similarly, if the value is non-negative. */
5390 else if (INT_CST_LT (integer_minus_one_node
, arg0
))
5392 /* If the value is negative, then the absolute value is
5396 unsigned HOST_WIDE_INT low
;
5398 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
5399 TREE_INT_CST_HIGH (arg0
),
5401 t
= build_int_2 (low
, high
);
5402 TREE_TYPE (t
) = type
;
5404 = (TREE_OVERFLOW (arg0
)
5405 | force_fit_type (t
, overflow
));
5406 TREE_CONSTANT_OVERFLOW (t
)
5407 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg0
);
5410 else if (TREE_CODE (arg0
) == REAL_CST
)
5412 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0
)))
5413 t
= build_real (type
,
5414 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
5417 else if (TREE_CODE (arg0
) == ABS_EXPR
|| TREE_CODE (arg0
) == NEGATE_EXPR
)
5418 return build1 (ABS_EXPR
, type
, TREE_OPERAND (arg0
, 0));
5422 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
5423 return convert (type
, arg0
);
5424 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
5425 return build (COMPLEX_EXPR
, type
,
5426 TREE_OPERAND (arg0
, 0),
5427 negate_expr (TREE_OPERAND (arg0
, 1)));
5428 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
5429 return build_complex (type
, TREE_REALPART (arg0
),
5430 negate_expr (TREE_IMAGPART (arg0
)));
5431 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
5432 return fold (build (TREE_CODE (arg0
), type
,
5433 fold (build1 (CONJ_EXPR
, type
,
5434 TREE_OPERAND (arg0
, 0))),
5435 fold (build1 (CONJ_EXPR
,
5436 type
, TREE_OPERAND (arg0
, 1)))));
5437 else if (TREE_CODE (arg0
) == CONJ_EXPR
)
5438 return TREE_OPERAND (arg0
, 0);
5444 t
= build_int_2 (~ TREE_INT_CST_LOW (arg0
),
5445 ~ TREE_INT_CST_HIGH (arg0
));
5446 TREE_TYPE (t
) = type
;
5447 force_fit_type (t
, 0);
5448 TREE_OVERFLOW (t
) = TREE_OVERFLOW (arg0
);
5449 TREE_CONSTANT_OVERFLOW (t
) = TREE_CONSTANT_OVERFLOW (arg0
);
5451 else if (TREE_CODE (arg0
) == BIT_NOT_EXPR
)
5452 return TREE_OPERAND (arg0
, 0);
5456 /* A + (-B) -> A - B */
5457 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
5458 return fold (build (MINUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
5459 /* (-A) + B -> B - A */
5460 if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5461 return fold (build (MINUS_EXPR
, type
, arg1
, TREE_OPERAND (arg0
, 0)));
5462 else if (! FLOAT_TYPE_P (type
))
5464 if (integer_zerop (arg1
))
5465 return non_lvalue (convert (type
, arg0
));
5467 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5468 with a constant, and the two constants have no bits in common,
5469 we should treat this as a BIT_IOR_EXPR since this may produce more
5471 if (TREE_CODE (arg0
) == BIT_AND_EXPR
5472 && TREE_CODE (arg1
) == BIT_AND_EXPR
5473 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
5474 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
5475 && integer_zerop (const_binop (BIT_AND_EXPR
,
5476 TREE_OPERAND (arg0
, 1),
5477 TREE_OPERAND (arg1
, 1), 0)))
5479 code
= BIT_IOR_EXPR
;
5483 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5484 (plus (plus (mult) (mult)) (foo)) so that we can
5485 take advantage of the factoring cases below. */
5486 if ((TREE_CODE (arg0
) == PLUS_EXPR
5487 && TREE_CODE (arg1
) == MULT_EXPR
)
5488 || (TREE_CODE (arg1
) == PLUS_EXPR
5489 && TREE_CODE (arg0
) == MULT_EXPR
))
5491 tree parg0
, parg1
, parg
, marg
;
5493 if (TREE_CODE (arg0
) == PLUS_EXPR
)
5494 parg
= arg0
, marg
= arg1
;
5496 parg
= arg1
, marg
= arg0
;
5497 parg0
= TREE_OPERAND (parg
, 0);
5498 parg1
= TREE_OPERAND (parg
, 1);
5502 if (TREE_CODE (parg0
) == MULT_EXPR
5503 && TREE_CODE (parg1
) != MULT_EXPR
)
5504 return fold (build (PLUS_EXPR
, type
,
5505 fold (build (PLUS_EXPR
, type
, parg0
, marg
)),
5507 if (TREE_CODE (parg0
) != MULT_EXPR
5508 && TREE_CODE (parg1
) == MULT_EXPR
)
5509 return fold (build (PLUS_EXPR
, type
,
5510 fold (build (PLUS_EXPR
, type
, parg1
, marg
)),
5514 if (TREE_CODE (arg0
) == MULT_EXPR
&& TREE_CODE (arg1
) == MULT_EXPR
)
5516 tree arg00
, arg01
, arg10
, arg11
;
5517 tree alt0
= NULL_TREE
, alt1
= NULL_TREE
, same
;
5519 /* (A * C) + (B * C) -> (A+B) * C.
5520 We are most concerned about the case where C is a constant,
5521 but other combinations show up during loop reduction. Since
5522 it is not difficult, try all four possibilities. */
5524 arg00
= TREE_OPERAND (arg0
, 0);
5525 arg01
= TREE_OPERAND (arg0
, 1);
5526 arg10
= TREE_OPERAND (arg1
, 0);
5527 arg11
= TREE_OPERAND (arg1
, 1);
5530 if (operand_equal_p (arg01
, arg11
, 0))
5531 same
= arg01
, alt0
= arg00
, alt1
= arg10
;
5532 else if (operand_equal_p (arg00
, arg10
, 0))
5533 same
= arg00
, alt0
= arg01
, alt1
= arg11
;
5534 else if (operand_equal_p (arg00
, arg11
, 0))
5535 same
= arg00
, alt0
= arg01
, alt1
= arg10
;
5536 else if (operand_equal_p (arg01
, arg10
, 0))
5537 same
= arg01
, alt0
= arg00
, alt1
= arg11
;
5539 /* No identical multiplicands; see if we can find a common
5540 power-of-two factor in non-power-of-two multiplies. This
5541 can help in multi-dimensional array access. */
5542 else if (TREE_CODE (arg01
) == INTEGER_CST
5543 && TREE_CODE (arg11
) == INTEGER_CST
5544 && TREE_INT_CST_HIGH (arg01
) == 0
5545 && TREE_INT_CST_HIGH (arg11
) == 0)
5547 HOST_WIDE_INT int01
, int11
, tmp
;
5548 int01
= TREE_INT_CST_LOW (arg01
);
5549 int11
= TREE_INT_CST_LOW (arg11
);
5551 /* Move min of absolute values to int11. */
5552 if ((int01
>= 0 ? int01
: -int01
)
5553 < (int11
>= 0 ? int11
: -int11
))
5555 tmp
= int01
, int01
= int11
, int11
= tmp
;
5556 alt0
= arg00
, arg00
= arg10
, arg10
= alt0
;
5557 alt0
= arg01
, arg01
= arg11
, arg11
= alt0
;
5560 if (exact_log2 (int11
) > 0 && int01
% int11
== 0)
5562 alt0
= fold (build (MULT_EXPR
, type
, arg00
,
5563 build_int_2 (int01
/ int11
, 0)));
5570 return fold (build (MULT_EXPR
, type
,
5571 fold (build (PLUS_EXPR
, type
, alt0
, alt1
)),
5575 /* In IEEE floating point, x+0 may not equal x. */
5576 else if ((TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
5577 || flag_unsafe_math_optimizations
)
5578 && real_zerop (arg1
))
5579 return non_lvalue (convert (type
, arg0
));
5580 /* x+(-0) equals x, even for IEEE. */
5581 else if (TREE_CODE (arg1
) == REAL_CST
5582 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1
)))
5583 return non_lvalue (convert (type
, arg0
));
5586 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5587 is a rotate of A by C1 bits. */
5588 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5589 is a rotate of A by B bits. */
5591 enum tree_code code0
, code1
;
5592 code0
= TREE_CODE (arg0
);
5593 code1
= TREE_CODE (arg1
);
5594 if (((code0
== RSHIFT_EXPR
&& code1
== LSHIFT_EXPR
)
5595 || (code1
== RSHIFT_EXPR
&& code0
== LSHIFT_EXPR
))
5596 && operand_equal_p (TREE_OPERAND (arg0
, 0),
5597 TREE_OPERAND (arg1
, 0), 0)
5598 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
5600 tree tree01
, tree11
;
5601 enum tree_code code01
, code11
;
5603 tree01
= TREE_OPERAND (arg0
, 1);
5604 tree11
= TREE_OPERAND (arg1
, 1);
5605 STRIP_NOPS (tree01
);
5606 STRIP_NOPS (tree11
);
5607 code01
= TREE_CODE (tree01
);
5608 code11
= TREE_CODE (tree11
);
5609 if (code01
== INTEGER_CST
5610 && code11
== INTEGER_CST
5611 && TREE_INT_CST_HIGH (tree01
) == 0
5612 && TREE_INT_CST_HIGH (tree11
) == 0
5613 && ((TREE_INT_CST_LOW (tree01
) + TREE_INT_CST_LOW (tree11
))
5614 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)))))
5615 return build (LROTATE_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5616 code0
== LSHIFT_EXPR
? tree01
: tree11
);
5617 else if (code11
== MINUS_EXPR
)
5619 tree tree110
, tree111
;
5620 tree110
= TREE_OPERAND (tree11
, 0);
5621 tree111
= TREE_OPERAND (tree11
, 1);
5622 STRIP_NOPS (tree110
);
5623 STRIP_NOPS (tree111
);
5624 if (TREE_CODE (tree110
) == INTEGER_CST
5625 && 0 == compare_tree_int (tree110
,
5627 (TREE_TYPE (TREE_OPERAND
5629 && operand_equal_p (tree01
, tree111
, 0))
5630 return build ((code0
== LSHIFT_EXPR
5633 type
, TREE_OPERAND (arg0
, 0), tree01
);
5635 else if (code01
== MINUS_EXPR
)
5637 tree tree010
, tree011
;
5638 tree010
= TREE_OPERAND (tree01
, 0);
5639 tree011
= TREE_OPERAND (tree01
, 1);
5640 STRIP_NOPS (tree010
);
5641 STRIP_NOPS (tree011
);
5642 if (TREE_CODE (tree010
) == INTEGER_CST
5643 && 0 == compare_tree_int (tree010
,
5645 (TREE_TYPE (TREE_OPERAND
5647 && operand_equal_p (tree11
, tree011
, 0))
5648 return build ((code0
!= LSHIFT_EXPR
5651 type
, TREE_OPERAND (arg0
, 0), tree11
);
5657 /* In most languages, can't associate operations on floats through
5658 parentheses. Rather than remember where the parentheses were, we
5659 don't associate floats at all. It shouldn't matter much. However,
5660 associating multiplications is only very slightly inaccurate, so do
5661 that if -funsafe-math-optimizations is specified. */
5664 && (! FLOAT_TYPE_P (type
)
5665 || (flag_unsafe_math_optimizations
&& code
== MULT_EXPR
)))
5667 tree var0
, con0
, lit0
, var1
, con1
, lit1
;
5669 /* Split both trees into variables, constants, and literals. Then
5670 associate each group together, the constants with literals,
5671 then the result with variables. This increases the chances of
5672 literals being recombined later and of generating relocatable
5673 expressions for the sum of a constant and literal. */
5674 var0
= split_tree (arg0
, code
, &con0
, &lit0
, 0);
5675 var1
= split_tree (arg1
, code
, &con1
, &lit1
, code
== MINUS_EXPR
);
5677 /* Only do something if we found more than two objects. Otherwise,
5678 nothing has changed and we risk infinite recursion. */
5679 if (2 < ((var0
!= 0) + (var1
!= 0) + (con0
!= 0) + (con1
!= 0)
5680 + (lit0
!= 0) + (lit1
!= 0)))
5682 var0
= associate_trees (var0
, var1
, code
, type
);
5683 con0
= associate_trees (con0
, con1
, code
, type
);
5684 lit0
= associate_trees (lit0
, lit1
, code
, type
);
5685 con0
= associate_trees (con0
, lit0
, code
, type
);
5686 return convert (type
, associate_trees (var0
, con0
, code
, type
));
5691 #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
5692 if (TREE_CODE (arg1
) == REAL_CST
)
5694 #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
5696 t1
= const_binop (code
, arg0
, arg1
, 0);
5697 if (t1
!= NULL_TREE
)
5699 /* The return value should always have
5700 the same type as the original expression. */
5701 if (TREE_TYPE (t1
) != TREE_TYPE (t
))
5702 t1
= convert (TREE_TYPE (t
), t1
);
5709 /* A - (-B) -> A + B */
5710 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
5711 return fold (build (PLUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
5712 /* (-A) - CST -> (-CST) - A for floating point (what about ints ?) */
5713 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == REAL_CST
)
5715 fold (build (MINUS_EXPR
, type
,
5716 build_real (TREE_TYPE (arg1
),
5717 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1
))),
5718 TREE_OPERAND (arg0
, 0)));
5720 if (! FLOAT_TYPE_P (type
))
5722 if (! wins
&& integer_zerop (arg0
))
5723 return negate_expr (convert (type
, arg1
));
5724 if (integer_zerop (arg1
))
5725 return non_lvalue (convert (type
, arg0
));
5727 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5728 about the case where C is a constant, just try one of the
5729 four possibilities. */
5731 if (TREE_CODE (arg0
) == MULT_EXPR
&& TREE_CODE (arg1
) == MULT_EXPR
5732 && operand_equal_p (TREE_OPERAND (arg0
, 1),
5733 TREE_OPERAND (arg1
, 1), 0))
5734 return fold (build (MULT_EXPR
, type
,
5735 fold (build (MINUS_EXPR
, type
,
5736 TREE_OPERAND (arg0
, 0),
5737 TREE_OPERAND (arg1
, 0))),
5738 TREE_OPERAND (arg0
, 1)));
5741 else if (TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
5742 || flag_unsafe_math_optimizations
)
5744 /* Except with IEEE floating point, 0-x equals -x. */
5745 if (! wins
&& real_zerop (arg0
))
5746 return negate_expr (convert (type
, arg1
));
5747 /* Except with IEEE floating point, x-0 equals x. */
5748 if (real_zerop (arg1
))
5749 return non_lvalue (convert (type
, arg0
));
5752 /* Fold &x - &x. This can happen from &x.foo - &x.
5753 This is unsafe for certain floats even in non-IEEE formats.
5754 In IEEE, it is unsafe because it does wrong for NaNs.
5755 Also note that operand_equal_p is always false if an operand
5758 if ((! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
5759 && operand_equal_p (arg0
, arg1
, 0))
5760 return convert (type
, integer_zero_node
);
5765 /* (-A) * (-B) -> A * B */
5766 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == NEGATE_EXPR
)
5767 return fold (build (MULT_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5768 TREE_OPERAND (arg1
, 0)));
5770 if (! FLOAT_TYPE_P (type
))
5772 if (integer_zerop (arg1
))
5773 return omit_one_operand (type
, arg1
, arg0
);
5774 if (integer_onep (arg1
))
5775 return non_lvalue (convert (type
, arg0
));
5777 /* (a * (1 << b)) is (a << b) */
5778 if (TREE_CODE (arg1
) == LSHIFT_EXPR
5779 && integer_onep (TREE_OPERAND (arg1
, 0)))
5780 return fold (build (LSHIFT_EXPR
, type
, arg0
,
5781 TREE_OPERAND (arg1
, 1)));
5782 if (TREE_CODE (arg0
) == LSHIFT_EXPR
5783 && integer_onep (TREE_OPERAND (arg0
, 0)))
5784 return fold (build (LSHIFT_EXPR
, type
, arg1
,
5785 TREE_OPERAND (arg0
, 1)));
5787 if (TREE_CODE (arg1
) == INTEGER_CST
5788 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
5790 return convert (type
, tem
);
5795 /* x*0 is 0, except for IEEE floating point. */
5796 if ((TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
5797 || flag_unsafe_math_optimizations
)
5798 && real_zerop (arg1
))
5799 return omit_one_operand (type
, arg1
, arg0
);
5800 /* In IEEE floating point, x*1 is not equivalent to x for snans.
5801 However, ANSI says we can drop signals,
5802 so we can do this anyway. */
5803 if (real_onep (arg1
))
5804 return non_lvalue (convert (type
, arg0
));
5806 if (! wins
&& real_twop (arg1
) && global_bindings_p () == 0
5807 && ! contains_placeholder_p (arg0
))
5809 tree arg
= save_expr (arg0
);
5810 return build (PLUS_EXPR
, type
, arg
, arg
);
5817 if (integer_all_onesp (arg1
))
5818 return omit_one_operand (type
, arg1
, arg0
);
5819 if (integer_zerop (arg1
))
5820 return non_lvalue (convert (type
, arg0
));
5821 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
5822 if (t1
!= NULL_TREE
)
5825 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
5827 This results in more efficient code for machines without a NAND
5828 instruction. Combine will canonicalize to the first form
5829 which will allow use of NAND instructions provided by the
5830 backend if they exist. */
5831 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
5832 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
5834 return fold (build1 (BIT_NOT_EXPR
, type
,
5835 build (BIT_AND_EXPR
, type
,
5836 TREE_OPERAND (arg0
, 0),
5837 TREE_OPERAND (arg1
, 0))));
5840 /* See if this can be simplified into a rotate first. If that
5841 is unsuccessful continue in the association code. */
5845 if (integer_zerop (arg1
))
5846 return non_lvalue (convert (type
, arg0
));
5847 if (integer_all_onesp (arg1
))
5848 return fold (build1 (BIT_NOT_EXPR
, type
, arg0
));
5850 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
5851 with a constant, and the two constants have no bits in common,
5852 we should treat this as a BIT_IOR_EXPR since this may produce more
5854 if (TREE_CODE (arg0
) == BIT_AND_EXPR
5855 && TREE_CODE (arg1
) == BIT_AND_EXPR
5856 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
5857 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
5858 && integer_zerop (const_binop (BIT_AND_EXPR
,
5859 TREE_OPERAND (arg0
, 1),
5860 TREE_OPERAND (arg1
, 1), 0)))
5862 code
= BIT_IOR_EXPR
;
5866 /* See if this can be simplified into a rotate first. If that
5867 is unsuccessful continue in the association code. */
5872 if (integer_all_onesp (arg1
))
5873 return non_lvalue (convert (type
, arg0
));
5874 if (integer_zerop (arg1
))
5875 return omit_one_operand (type
, arg1
, arg0
);
5876 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
5877 if (t1
!= NULL_TREE
)
5879 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5880 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == NOP_EXPR
5881 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1
, 0))))
5884 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1
, 0)));
5886 if (prec
< BITS_PER_WORD
&& prec
< HOST_BITS_PER_WIDE_INT
5887 && (~TREE_INT_CST_LOW (arg0
)
5888 & (((HOST_WIDE_INT
) 1 << prec
) - 1)) == 0)
5889 return build1 (NOP_EXPR
, type
, TREE_OPERAND (arg1
, 0));
5891 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) == NOP_EXPR
5892 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
5895 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)));
5897 if (prec
< BITS_PER_WORD
&& prec
< HOST_BITS_PER_WIDE_INT
5898 && (~TREE_INT_CST_LOW (arg1
)
5899 & (((HOST_WIDE_INT
) 1 << prec
) - 1)) == 0)
5900 return build1 (NOP_EXPR
, type
, TREE_OPERAND (arg0
, 0));
5903 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
5905 This results in more efficient code for machines without a NOR
5906 instruction. Combine will canonicalize to the first form
5907 which will allow use of NOR instructions provided by the
5908 backend if they exist. */
5909 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
5910 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
5912 return fold (build1 (BIT_NOT_EXPR
, type
,
5913 build (BIT_IOR_EXPR
, type
,
5914 TREE_OPERAND (arg0
, 0),
5915 TREE_OPERAND (arg1
, 0))));
5920 case BIT_ANDTC_EXPR
:
5921 if (integer_all_onesp (arg0
))
5922 return non_lvalue (convert (type
, arg1
));
5923 if (integer_zerop (arg0
))
5924 return omit_one_operand (type
, arg0
, arg1
);
5925 if (TREE_CODE (arg1
) == INTEGER_CST
)
5927 arg1
= fold (build1 (BIT_NOT_EXPR
, type
, arg1
));
5928 code
= BIT_AND_EXPR
;
5934 /* In most cases, do nothing with a divide by zero. */
5935 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5936 #ifndef REAL_INFINITY
5937 if (TREE_CODE (arg1
) == REAL_CST
&& real_zerop (arg1
))
5940 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5942 /* (-A) / (-B) -> A / B */
5943 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == NEGATE_EXPR
)
5944 return fold (build (RDIV_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5945 TREE_OPERAND (arg1
, 0)));
5947 /* In IEEE floating point, x/1 is not equivalent to x for snans.
5948 However, ANSI says we can drop signals, so we can do this anyway. */
5949 if (real_onep (arg1
))
5950 return non_lvalue (convert (type
, arg0
));
5952 /* If ARG1 is a constant, we can convert this to a multiply by the
5953 reciprocal. This does not have the same rounding properties,
5954 so only do this if -funsafe-math-optimizations. We can actually
5955 always safely do it if ARG1 is a power of two, but it's hard to
5956 tell if it is or not in a portable manner. */
5957 if (TREE_CODE (arg1
) == REAL_CST
)
5959 if (flag_unsafe_math_optimizations
5960 && 0 != (tem
= const_binop (code
, build_real (type
, dconst1
),
5962 return fold (build (MULT_EXPR
, type
, arg0
, tem
));
5963 /* Find the reciprocal if optimizing and the result is exact. */
5967 r
= TREE_REAL_CST (arg1
);
5968 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0
)), &r
))
5970 tem
= build_real (type
, r
);
5971 return fold (build (MULT_EXPR
, type
, arg0
, tem
));
5975 /* Convert A/B/C to A/(B*C). */
5976 if (flag_unsafe_math_optimizations
5977 && TREE_CODE (arg0
) == RDIV_EXPR
)
5979 return fold (build (RDIV_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5980 build (MULT_EXPR
, type
, TREE_OPERAND (arg0
, 1),
5983 /* Convert A/(B/C) to (A/B)*C. */
5984 if (flag_unsafe_math_optimizations
5985 && TREE_CODE (arg1
) == RDIV_EXPR
)
5987 return fold (build (MULT_EXPR
, type
,
5988 build (RDIV_EXPR
, type
, arg0
,
5989 TREE_OPERAND (arg1
, 0)),
5990 TREE_OPERAND (arg1
, 1)));
5994 case TRUNC_DIV_EXPR
:
5995 case ROUND_DIV_EXPR
:
5996 case FLOOR_DIV_EXPR
:
5998 case EXACT_DIV_EXPR
:
5999 if (integer_onep (arg1
))
6000 return non_lvalue (convert (type
, arg0
));
6001 if (integer_zerop (arg1
))
6004 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
6005 operation, EXACT_DIV_EXPR.
6007 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
6008 At one time others generated faster code, it's not clear if they do
6009 after the last round to changes to the DIV code in expmed.c. */
6010 if ((code
== CEIL_DIV_EXPR
|| code
== FLOOR_DIV_EXPR
)
6011 && multiple_of_p (type
, arg0
, arg1
))
6012 return fold (build (EXACT_DIV_EXPR
, type
, arg0
, arg1
));
6014 if (TREE_CODE (arg1
) == INTEGER_CST
6015 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
6017 return convert (type
, tem
);
6022 case FLOOR_MOD_EXPR
:
6023 case ROUND_MOD_EXPR
:
6024 case TRUNC_MOD_EXPR
:
6025 if (integer_onep (arg1
))
6026 return omit_one_operand (type
, integer_zero_node
, arg0
);
6027 if (integer_zerop (arg1
))
6030 if (TREE_CODE (arg1
) == INTEGER_CST
6031 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
6033 return convert (type
, tem
);
6041 if (integer_zerop (arg1
))
6042 return non_lvalue (convert (type
, arg0
));
6043 /* Since negative shift count is not well-defined,
6044 don't try to compute it in the compiler. */
6045 if (TREE_CODE (arg1
) == INTEGER_CST
&& tree_int_cst_sgn (arg1
) < 0)
6047 /* Rewrite an LROTATE_EXPR by a constant into an
6048 RROTATE_EXPR by a new constant. */
6049 if (code
== LROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
)
6051 TREE_SET_CODE (t
, RROTATE_EXPR
);
6052 code
= RROTATE_EXPR
;
6053 TREE_OPERAND (t
, 1) = arg1
6056 convert (TREE_TYPE (arg1
),
6057 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type
)), 0)),
6059 if (tree_int_cst_sgn (arg1
) < 0)
6063 /* If we have a rotate of a bit operation with the rotate count and
6064 the second operand of the bit operation both constant,
6065 permute the two operations. */
6066 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
6067 && (TREE_CODE (arg0
) == BIT_AND_EXPR
6068 || TREE_CODE (arg0
) == BIT_ANDTC_EXPR
6069 || TREE_CODE (arg0
) == BIT_IOR_EXPR
6070 || TREE_CODE (arg0
) == BIT_XOR_EXPR
)
6071 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
6072 return fold (build (TREE_CODE (arg0
), type
,
6073 fold (build (code
, type
,
6074 TREE_OPERAND (arg0
, 0), arg1
)),
6075 fold (build (code
, type
,
6076 TREE_OPERAND (arg0
, 1), arg1
))));
6078 /* Two consecutive rotates adding up to the width of the mode can
6080 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
6081 && TREE_CODE (arg0
) == RROTATE_EXPR
6082 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
6083 && TREE_INT_CST_HIGH (arg1
) == 0
6084 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0
, 1)) == 0
6085 && ((TREE_INT_CST_LOW (arg1
)
6086 + TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1)))
6087 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type
))))
6088 return TREE_OPERAND (arg0
, 0);
6093 if (operand_equal_p (arg0
, arg1
, 0))
6094 return omit_one_operand (type
, arg0
, arg1
);
6095 if (INTEGRAL_TYPE_P (type
)
6096 && operand_equal_p (arg1
, TYPE_MIN_VALUE (type
), 1))
6097 return omit_one_operand (type
, arg1
, arg0
);
6101 if (operand_equal_p (arg0
, arg1
, 0))
6102 return omit_one_operand (type
, arg0
, arg1
);
6103 if (INTEGRAL_TYPE_P (type
)
6104 && TYPE_MAX_VALUE (type
)
6105 && operand_equal_p (arg1
, TYPE_MAX_VALUE (type
), 1))
6106 return omit_one_operand (type
, arg1
, arg0
);
6109 case TRUTH_NOT_EXPR
:
6110 /* Note that the operand of this must be an int
6111 and its values must be 0 or 1.
6112 ("true" is a fixed value perhaps depending on the language,
6113 but we don't handle values other than 1 correctly yet.) */
6114 tem
= invert_truthvalue (arg0
);
6115 /* Avoid infinite recursion. */
6116 if (TREE_CODE (tem
) == TRUTH_NOT_EXPR
)
6118 return convert (type
, tem
);
6120 case TRUTH_ANDIF_EXPR
:
6121 /* Note that the operands of this must be ints
6122 and their values must be 0 or 1.
6123 ("true" is a fixed value perhaps depending on the language.) */
6124 /* If first arg is constant zero, return it. */
6125 if (integer_zerop (arg0
))
6126 return convert (type
, arg0
);
6127 case TRUTH_AND_EXPR
:
6128 /* If either arg is constant true, drop it. */
6129 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6130 return non_lvalue (convert (type
, arg1
));
6131 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
)
6132 /* Preserve sequence points. */
6133 && (code
!= TRUTH_ANDIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
6134 return non_lvalue (convert (type
, arg0
));
6135 /* If second arg is constant zero, result is zero, but first arg
6136 must be evaluated. */
6137 if (integer_zerop (arg1
))
6138 return omit_one_operand (type
, arg1
, arg0
);
6139 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
6140 case will be handled here. */
6141 if (integer_zerop (arg0
))
6142 return omit_one_operand (type
, arg0
, arg1
);
6145 /* We only do these simplifications if we are optimizing. */
6149 /* Check for things like (A || B) && (A || C). We can convert this
6150 to A || (B && C). Note that either operator can be any of the four
6151 truth and/or operations and the transformation will still be
6152 valid. Also note that we only care about order for the
6153 ANDIF and ORIF operators. If B contains side effects, this
6154 might change the truth-value of A. */
6155 if (TREE_CODE (arg0
) == TREE_CODE (arg1
)
6156 && (TREE_CODE (arg0
) == TRUTH_ANDIF_EXPR
6157 || TREE_CODE (arg0
) == TRUTH_ORIF_EXPR
6158 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
6159 || TREE_CODE (arg0
) == TRUTH_OR_EXPR
)
6160 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0
, 1)))
6162 tree a00
= TREE_OPERAND (arg0
, 0);
6163 tree a01
= TREE_OPERAND (arg0
, 1);
6164 tree a10
= TREE_OPERAND (arg1
, 0);
6165 tree a11
= TREE_OPERAND (arg1
, 1);
6166 int commutative
= ((TREE_CODE (arg0
) == TRUTH_OR_EXPR
6167 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
)
6168 && (code
== TRUTH_AND_EXPR
6169 || code
== TRUTH_OR_EXPR
));
6171 if (operand_equal_p (a00
, a10
, 0))
6172 return fold (build (TREE_CODE (arg0
), type
, a00
,
6173 fold (build (code
, type
, a01
, a11
))));
6174 else if (commutative
&& operand_equal_p (a00
, a11
, 0))
6175 return fold (build (TREE_CODE (arg0
), type
, a00
,
6176 fold (build (code
, type
, a01
, a10
))));
6177 else if (commutative
&& operand_equal_p (a01
, a10
, 0))
6178 return fold (build (TREE_CODE (arg0
), type
, a01
,
6179 fold (build (code
, type
, a00
, a11
))));
6181 /* This case if tricky because we must either have commutative
6182 operators or else A10 must not have side-effects. */
6184 else if ((commutative
|| ! TREE_SIDE_EFFECTS (a10
))
6185 && operand_equal_p (a01
, a11
, 0))
6186 return fold (build (TREE_CODE (arg0
), type
,
6187 fold (build (code
, type
, a00
, a10
)),
6191 /* See if we can build a range comparison. */
6192 if (0 != (tem
= fold_range_test (t
)))
6195 /* Check for the possibility of merging component references. If our
6196 lhs is another similar operation, try to merge its rhs with our
6197 rhs. Then try to merge our lhs and rhs. */
6198 if (TREE_CODE (arg0
) == code
6199 && 0 != (tem
= fold_truthop (code
, type
,
6200 TREE_OPERAND (arg0
, 1), arg1
)))
6201 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6203 if ((tem
= fold_truthop (code
, type
, arg0
, arg1
)) != 0)
6208 case TRUTH_ORIF_EXPR
:
6209 /* Note that the operands of this must be ints
6210 and their values must be 0 or true.
6211 ("true" is a fixed value perhaps depending on the language.) */
6212 /* If first arg is constant true, return it. */
6213 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6214 return convert (type
, arg0
);
6216 /* If either arg is constant zero, drop it. */
6217 if (TREE_CODE (arg0
) == INTEGER_CST
&& integer_zerop (arg0
))
6218 return non_lvalue (convert (type
, arg1
));
6219 if (TREE_CODE (arg1
) == INTEGER_CST
&& integer_zerop (arg1
)
6220 /* Preserve sequence points. */
6221 && (code
!= TRUTH_ORIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
6222 return non_lvalue (convert (type
, arg0
));
6223 /* If second arg is constant true, result is true, but we must
6224 evaluate first arg. */
6225 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
))
6226 return omit_one_operand (type
, arg1
, arg0
);
6227 /* Likewise for first arg, but note this only occurs here for
6229 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6230 return omit_one_operand (type
, arg0
, arg1
);
6233 case TRUTH_XOR_EXPR
:
6234 /* If either arg is constant zero, drop it. */
6235 if (integer_zerop (arg0
))
6236 return non_lvalue (convert (type
, arg1
));
6237 if (integer_zerop (arg1
))
6238 return non_lvalue (convert (type
, arg0
));
6239 /* If either arg is constant true, this is a logical inversion. */
6240 if (integer_onep (arg0
))
6241 return non_lvalue (convert (type
, invert_truthvalue (arg1
)));
6242 if (integer_onep (arg1
))
6243 return non_lvalue (convert (type
, invert_truthvalue (arg0
)));
6252 if (FLOAT_TYPE_P (TREE_TYPE (arg0
)))
6254 /* (-a) CMP (-b) -> b CMP a */
6255 if (TREE_CODE (arg0
) == NEGATE_EXPR
6256 && TREE_CODE (arg1
) == NEGATE_EXPR
)
6257 return fold (build (code
, type
, TREE_OPERAND (arg1
, 0),
6258 TREE_OPERAND (arg0
, 0)));
6259 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6260 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == REAL_CST
)
6263 (swap_tree_comparison (code
), type
,
6264 TREE_OPERAND (arg0
, 0),
6265 build_real (TREE_TYPE (arg1
),
6266 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1
)))));
6267 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6268 /* a CMP (-0) -> a CMP 0 */
6269 if (TREE_CODE (arg1
) == REAL_CST
6270 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1
)))
6271 return fold (build (code
, type
, arg0
,
6272 build_real (TREE_TYPE (arg1
), dconst0
)));
6275 /* If one arg is a constant integer, put it last. */
6276 if (TREE_CODE (arg0
) == INTEGER_CST
6277 && TREE_CODE (arg1
) != INTEGER_CST
)
6279 TREE_OPERAND (t
, 0) = arg1
;
6280 TREE_OPERAND (t
, 1) = arg0
;
6281 arg0
= TREE_OPERAND (t
, 0);
6282 arg1
= TREE_OPERAND (t
, 1);
6283 code
= swap_tree_comparison (code
);
6284 TREE_SET_CODE (t
, code
);
6287 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6288 First, see if one arg is constant; find the constant arg
6289 and the other one. */
6291 tree constop
= 0, varop
= NULL_TREE
;
6292 int constopnum
= -1;
6294 if (TREE_CONSTANT (arg1
))
6295 constopnum
= 1, constop
= arg1
, varop
= arg0
;
6296 if (TREE_CONSTANT (arg0
))
6297 constopnum
= 0, constop
= arg0
, varop
= arg1
;
6299 if (constop
&& TREE_CODE (varop
) == POSTINCREMENT_EXPR
)
6301 /* This optimization is invalid for ordered comparisons
6302 if CONST+INCR overflows or if foo+incr might overflow.
6303 This optimization is invalid for floating point due to rounding.
6304 For pointer types we assume overflow doesn't happen. */
6305 if (POINTER_TYPE_P (TREE_TYPE (varop
))
6306 || (! FLOAT_TYPE_P (TREE_TYPE (varop
))
6307 && (code
== EQ_EXPR
|| code
== NE_EXPR
)))
6310 = fold (build (PLUS_EXPR
, TREE_TYPE (varop
),
6311 constop
, TREE_OPERAND (varop
, 1)));
6313 /* Do not overwrite the current varop to be a preincrement,
6314 create a new node so that we won't confuse our caller who
6315 might create trees and throw them away, reusing the
6316 arguments that they passed to build. This shows up in
6317 the THEN or ELSE parts of ?: being postincrements. */
6318 varop
= build (PREINCREMENT_EXPR
, TREE_TYPE (varop
),
6319 TREE_OPERAND (varop
, 0),
6320 TREE_OPERAND (varop
, 1));
6322 /* If VAROP is a reference to a bitfield, we must mask
6323 the constant by the width of the field. */
6324 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
6325 && DECL_BIT_FIELD(TREE_OPERAND
6326 (TREE_OPERAND (varop
, 0), 1)))
6329 = TREE_INT_CST_LOW (DECL_SIZE
6331 (TREE_OPERAND (varop
, 0), 1)));
6332 tree mask
, unsigned_type
;
6333 unsigned int precision
;
6334 tree folded_compare
;
6336 /* First check whether the comparison would come out
6337 always the same. If we don't do that we would
6338 change the meaning with the masking. */
6339 if (constopnum
== 0)
6340 folded_compare
= fold (build (code
, type
, constop
,
6341 TREE_OPERAND (varop
, 0)));
6343 folded_compare
= fold (build (code
, type
,
6344 TREE_OPERAND (varop
, 0),
6346 if (integer_zerop (folded_compare
)
6347 || integer_onep (folded_compare
))
6348 return omit_one_operand (type
, folded_compare
, varop
);
6350 unsigned_type
= type_for_size (size
, 1);
6351 precision
= TYPE_PRECISION (unsigned_type
);
6352 mask
= build_int_2 (~0, ~0);
6353 TREE_TYPE (mask
) = unsigned_type
;
6354 force_fit_type (mask
, 0);
6355 mask
= const_binop (RSHIFT_EXPR
, mask
,
6356 size_int (precision
- size
), 0);
6357 newconst
= fold (build (BIT_AND_EXPR
,
6358 TREE_TYPE (varop
), newconst
,
6359 convert (TREE_TYPE (varop
),
6363 t
= build (code
, type
,
6364 (constopnum
== 0) ? newconst
: varop
,
6365 (constopnum
== 1) ? newconst
: varop
);
6369 else if (constop
&& TREE_CODE (varop
) == POSTDECREMENT_EXPR
)
6371 if (POINTER_TYPE_P (TREE_TYPE (varop
))
6372 || (! FLOAT_TYPE_P (TREE_TYPE (varop
))
6373 && (code
== EQ_EXPR
|| code
== NE_EXPR
)))
6376 = fold (build (MINUS_EXPR
, TREE_TYPE (varop
),
6377 constop
, TREE_OPERAND (varop
, 1)));
6379 /* Do not overwrite the current varop to be a predecrement,
6380 create a new node so that we won't confuse our caller who
6381 might create trees and throw them away, reusing the
6382 arguments that they passed to build. This shows up in
6383 the THEN or ELSE parts of ?: being postdecrements. */
6384 varop
= build (PREDECREMENT_EXPR
, TREE_TYPE (varop
),
6385 TREE_OPERAND (varop
, 0),
6386 TREE_OPERAND (varop
, 1));
6388 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
6389 && DECL_BIT_FIELD(TREE_OPERAND
6390 (TREE_OPERAND (varop
, 0), 1)))
6393 = TREE_INT_CST_LOW (DECL_SIZE
6395 (TREE_OPERAND (varop
, 0), 1)));
6396 tree mask
, unsigned_type
;
6397 unsigned int precision
;
6398 tree folded_compare
;
6400 if (constopnum
== 0)
6401 folded_compare
= fold (build (code
, type
, constop
,
6402 TREE_OPERAND (varop
, 0)));
6404 folded_compare
= fold (build (code
, type
,
6405 TREE_OPERAND (varop
, 0),
6407 if (integer_zerop (folded_compare
)
6408 || integer_onep (folded_compare
))
6409 return omit_one_operand (type
, folded_compare
, varop
);
6411 unsigned_type
= type_for_size (size
, 1);
6412 precision
= TYPE_PRECISION (unsigned_type
);
6413 mask
= build_int_2 (~0, ~0);
6414 TREE_TYPE (mask
) = TREE_TYPE (varop
);
6415 force_fit_type (mask
, 0);
6416 mask
= const_binop (RSHIFT_EXPR
, mask
,
6417 size_int (precision
- size
), 0);
6418 newconst
= fold (build (BIT_AND_EXPR
,
6419 TREE_TYPE (varop
), newconst
,
6420 convert (TREE_TYPE (varop
),
6424 t
= build (code
, type
,
6425 (constopnum
== 0) ? newconst
: varop
,
6426 (constopnum
== 1) ? newconst
: varop
);
6432 /* Change X >= CST to X > (CST - 1) if CST is positive. */
6433 if (TREE_CODE (arg1
) == INTEGER_CST
6434 && TREE_CODE (arg0
) != INTEGER_CST
6435 && tree_int_cst_sgn (arg1
) > 0)
6437 switch (TREE_CODE (t
))
6441 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6442 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6447 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6448 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6456 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6457 a MINUS_EXPR of a constant, we can convert it into a comparison with
6458 a revised constant as long as no overflow occurs. */
6459 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6460 && TREE_CODE (arg1
) == INTEGER_CST
6461 && (TREE_CODE (arg0
) == PLUS_EXPR
6462 || TREE_CODE (arg0
) == MINUS_EXPR
)
6463 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
6464 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
6465 ? MINUS_EXPR
: PLUS_EXPR
,
6466 arg1
, TREE_OPERAND (arg0
, 1), 0))
6467 && ! TREE_CONSTANT_OVERFLOW (tem
))
6468 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6470 /* Similarly for a NEGATE_EXPR. */
6471 else if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6472 && TREE_CODE (arg0
) == NEGATE_EXPR
6473 && TREE_CODE (arg1
) == INTEGER_CST
6474 && 0 != (tem
= negate_expr (arg1
))
6475 && TREE_CODE (tem
) == INTEGER_CST
6476 && ! TREE_CONSTANT_OVERFLOW (tem
))
6477 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6479 /* If we have X - Y == 0, we can convert that to X == Y and similarly
6480 for !=. Don't do this for ordered comparisons due to overflow. */
6481 else if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
6482 && integer_zerop (arg1
) && TREE_CODE (arg0
) == MINUS_EXPR
)
6483 return fold (build (code
, type
,
6484 TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg0
, 1)));
6486 /* If we are widening one operand of an integer comparison,
6487 see if the other operand is similarly being widened. Perhaps we
6488 can do the comparison in the narrower type. */
6489 else if (TREE_CODE (TREE_TYPE (arg0
)) == INTEGER_TYPE
6490 && TREE_CODE (arg0
) == NOP_EXPR
6491 && (tem
= get_unwidened (arg0
, NULL_TREE
)) != arg0
6492 && (t1
= get_unwidened (arg1
, TREE_TYPE (tem
))) != 0
6493 && (TREE_TYPE (t1
) == TREE_TYPE (tem
)
6494 || (TREE_CODE (t1
) == INTEGER_CST
6495 && int_fits_type_p (t1
, TREE_TYPE (tem
)))))
6496 return fold (build (code
, type
, tem
, convert (TREE_TYPE (tem
), t1
)));
6498 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
6499 constant, we can simplify it. */
6500 else if (TREE_CODE (arg1
) == INTEGER_CST
6501 && (TREE_CODE (arg0
) == MIN_EXPR
6502 || TREE_CODE (arg0
) == MAX_EXPR
)
6503 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
6504 return optimize_minmax_comparison (t
);
6506 /* If we are comparing an ABS_EXPR with a constant, we can
6507 convert all the cases into explicit comparisons, but they may
6508 well not be faster than doing the ABS and one comparison.
6509 But ABS (X) <= C is a range comparison, which becomes a subtraction
6510 and a comparison, and is probably faster. */
6511 else if (code
== LE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
6512 && TREE_CODE (arg0
) == ABS_EXPR
6513 && ! TREE_SIDE_EFFECTS (arg0
)
6514 && (0 != (tem
= negate_expr (arg1
)))
6515 && TREE_CODE (tem
) == INTEGER_CST
6516 && ! TREE_CONSTANT_OVERFLOW (tem
))
6517 return fold (build (TRUTH_ANDIF_EXPR
, type
,
6518 build (GE_EXPR
, type
, TREE_OPERAND (arg0
, 0), tem
),
6519 build (LE_EXPR
, type
,
6520 TREE_OPERAND (arg0
, 0), arg1
)));
6522 /* If this is an EQ or NE comparison with zero and ARG0 is
6523 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
6524 two operations, but the latter can be done in one less insn
6525 on machines that have only two-operand insns or on which a
6526 constant cannot be the first operand. */
6527 if (integer_zerop (arg1
) && (code
== EQ_EXPR
|| code
== NE_EXPR
)
6528 && TREE_CODE (arg0
) == BIT_AND_EXPR
)
6530 if (TREE_CODE (TREE_OPERAND (arg0
, 0)) == LSHIFT_EXPR
6531 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0)))
6533 fold (build (code
, type
,
6534 build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
6536 TREE_TYPE (TREE_OPERAND (arg0
, 0)),
6537 TREE_OPERAND (arg0
, 1),
6538 TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1)),
6539 convert (TREE_TYPE (arg0
),
6542 else if (TREE_CODE (TREE_OPERAND (arg0
, 1)) == LSHIFT_EXPR
6543 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 1), 0)))
6545 fold (build (code
, type
,
6546 build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
6548 TREE_TYPE (TREE_OPERAND (arg0
, 1)),
6549 TREE_OPERAND (arg0
, 0),
6550 TREE_OPERAND (TREE_OPERAND (arg0
, 1), 1)),
6551 convert (TREE_TYPE (arg0
),
6556 /* If this is an NE or EQ comparison of zero against the result of a
6557 signed MOD operation whose second operand is a power of 2, make
6558 the MOD operation unsigned since it is simpler and equivalent. */
6559 if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
6560 && integer_zerop (arg1
)
6561 && ! TREE_UNSIGNED (TREE_TYPE (arg0
))
6562 && (TREE_CODE (arg0
) == TRUNC_MOD_EXPR
6563 || TREE_CODE (arg0
) == CEIL_MOD_EXPR
6564 || TREE_CODE (arg0
) == FLOOR_MOD_EXPR
6565 || TREE_CODE (arg0
) == ROUND_MOD_EXPR
)
6566 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
6568 tree newtype
= unsigned_type (TREE_TYPE (arg0
));
6569 tree newmod
= build (TREE_CODE (arg0
), newtype
,
6570 convert (newtype
, TREE_OPERAND (arg0
, 0)),
6571 convert (newtype
, TREE_OPERAND (arg0
, 1)));
6573 return build (code
, type
, newmod
, convert (newtype
, arg1
));
6576 /* If this is an NE comparison of zero with an AND of one, remove the
6577 comparison since the AND will give the correct value. */
6578 if (code
== NE_EXPR
&& integer_zerop (arg1
)
6579 && TREE_CODE (arg0
) == BIT_AND_EXPR
6580 && integer_onep (TREE_OPERAND (arg0
, 1)))
6581 return convert (type
, arg0
);
6583 /* If we have (A & C) == C where C is a power of 2, convert this into
6584 (A & C) != 0. Similarly for NE_EXPR. */
6585 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6586 && TREE_CODE (arg0
) == BIT_AND_EXPR
6587 && integer_pow2p (TREE_OPERAND (arg0
, 1))
6588 && operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
6589 return build (code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
, type
,
6590 arg0
, integer_zero_node
);
6592 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
6593 and similarly for >= into !=. */
6594 if ((code
== LT_EXPR
|| code
== GE_EXPR
)
6595 && TREE_UNSIGNED (TREE_TYPE (arg0
))
6596 && TREE_CODE (arg1
) == LSHIFT_EXPR
6597 && integer_onep (TREE_OPERAND (arg1
, 0)))
6598 return build (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
6599 build (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
6600 TREE_OPERAND (arg1
, 1)),
6601 convert (TREE_TYPE (arg0
), integer_zero_node
));
6603 else if ((code
== LT_EXPR
|| code
== GE_EXPR
)
6604 && TREE_UNSIGNED (TREE_TYPE (arg0
))
6605 && (TREE_CODE (arg1
) == NOP_EXPR
6606 || TREE_CODE (arg1
) == CONVERT_EXPR
)
6607 && TREE_CODE (TREE_OPERAND (arg1
, 0)) == LSHIFT_EXPR
6608 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0)))
6610 build (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
6611 convert (TREE_TYPE (arg0
),
6612 build (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
6613 TREE_OPERAND (TREE_OPERAND (arg1
, 0), 1))),
6614 convert (TREE_TYPE (arg0
), integer_zero_node
));
6616 /* Simplify comparison of something with itself. (For IEEE
6617 floating-point, we can only do some of these simplifications.) */
6618 if (operand_equal_p (arg0
, arg1
, 0))
6625 if (! FLOAT_TYPE_P (TREE_TYPE (arg0
)))
6626 return constant_boolean_node (1, type
);
6628 TREE_SET_CODE (t
, code
);
6632 /* For NE, we can only do this simplification if integer. */
6633 if (FLOAT_TYPE_P (TREE_TYPE (arg0
)))
6635 /* ... fall through ... */
6638 return constant_boolean_node (0, type
);
6644 /* An unsigned comparison against 0 can be simplified. */
6645 if (integer_zerop (arg1
)
6646 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
6647 || POINTER_TYPE_P (TREE_TYPE (arg1
)))
6648 && TREE_UNSIGNED (TREE_TYPE (arg1
)))
6650 switch (TREE_CODE (t
))
6654 TREE_SET_CODE (t
, NE_EXPR
);
6658 TREE_SET_CODE (t
, EQ_EXPR
);
6661 return omit_one_operand (type
,
6662 convert (type
, integer_one_node
),
6665 return omit_one_operand (type
,
6666 convert (type
, integer_zero_node
),
6673 /* Comparisons with the highest or lowest possible integer of
6674 the specified size will have known values and an unsigned
6675 <= 0x7fffffff can be simplified. */
6677 int width
= GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1
)));
6679 if (TREE_CODE (arg1
) == INTEGER_CST
6680 && ! TREE_CONSTANT_OVERFLOW (arg1
)
6681 && width
<= HOST_BITS_PER_WIDE_INT
6682 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
6683 || POINTER_TYPE_P (TREE_TYPE (arg1
))))
6685 if (TREE_INT_CST_HIGH (arg1
) == 0
6686 && (TREE_INT_CST_LOW (arg1
)
6687 == ((unsigned HOST_WIDE_INT
) 1 << (width
- 1)) - 1)
6688 && ! TREE_UNSIGNED (TREE_TYPE (arg1
)))
6689 switch (TREE_CODE (t
))
6692 return omit_one_operand (type
,
6693 convert (type
, integer_zero_node
),
6696 TREE_SET_CODE (t
, EQ_EXPR
);
6700 return omit_one_operand (type
,
6701 convert (type
, integer_one_node
),
6704 TREE_SET_CODE (t
, NE_EXPR
);
6711 else if (TREE_INT_CST_HIGH (arg1
) == -1
6712 && (- TREE_INT_CST_LOW (arg1
)
6713 == ((unsigned HOST_WIDE_INT
) 1 << (width
- 1)))
6714 && ! TREE_UNSIGNED (TREE_TYPE (arg1
)))
6715 switch (TREE_CODE (t
))
6718 return omit_one_operand (type
,
6719 convert (type
, integer_zero_node
),
6722 TREE_SET_CODE (t
, EQ_EXPR
);
6726 return omit_one_operand (type
,
6727 convert (type
, integer_one_node
),
6730 TREE_SET_CODE (t
, NE_EXPR
);
6737 else if (TREE_INT_CST_HIGH (arg1
) == 0
6738 && (TREE_INT_CST_LOW (arg1
)
6739 == ((unsigned HOST_WIDE_INT
) 1 << (width
- 1)) - 1)
6740 && TREE_UNSIGNED (TREE_TYPE (arg1
))
6741 /* signed_type does not work on pointer types. */
6742 && INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
6744 switch (TREE_CODE (t
))
6747 return fold (build (GE_EXPR
, type
,
6748 convert (signed_type (TREE_TYPE (arg0
)),
6750 convert (signed_type (TREE_TYPE (arg1
)),
6751 integer_zero_node
)));
6753 return fold (build (LT_EXPR
, type
,
6754 convert (signed_type (TREE_TYPE (arg0
)),
6756 convert (signed_type (TREE_TYPE (arg1
)),
6757 integer_zero_node
)));
6765 /* If we are comparing an expression that just has comparisons
6766 of two integer values, arithmetic expressions of those comparisons,
6767 and constants, we can simplify it. There are only three cases
6768 to check: the two values can either be equal, the first can be
6769 greater, or the second can be greater. Fold the expression for
6770 those three values. Since each value must be 0 or 1, we have
6771 eight possibilities, each of which corresponds to the constant 0
6772 or 1 or one of the six possible comparisons.
6774 This handles common cases like (a > b) == 0 but also handles
6775 expressions like ((x > y) - (y > x)) > 0, which supposedly
6776 occur in macroized code. */
6778 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) != INTEGER_CST
)
6780 tree cval1
= 0, cval2
= 0;
6783 if (twoval_comparison_p (arg0
, &cval1
, &cval2
, &save_p
)
6784 /* Don't handle degenerate cases here; they should already
6785 have been handled anyway. */
6786 && cval1
!= 0 && cval2
!= 0
6787 && ! (TREE_CONSTANT (cval1
) && TREE_CONSTANT (cval2
))
6788 && TREE_TYPE (cval1
) == TREE_TYPE (cval2
)
6789 && INTEGRAL_TYPE_P (TREE_TYPE (cval1
))
6790 && TYPE_MAX_VALUE (TREE_TYPE (cval1
))
6791 && TYPE_MAX_VALUE (TREE_TYPE (cval2
))
6792 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1
)),
6793 TYPE_MAX_VALUE (TREE_TYPE (cval2
)), 0))
6795 tree maxval
= TYPE_MAX_VALUE (TREE_TYPE (cval1
));
6796 tree minval
= TYPE_MIN_VALUE (TREE_TYPE (cval1
));
6798 /* We can't just pass T to eval_subst in case cval1 or cval2
6799 was the same as ARG1. */
6802 = fold (build (code
, type
,
6803 eval_subst (arg0
, cval1
, maxval
, cval2
, minval
),
6806 = fold (build (code
, type
,
6807 eval_subst (arg0
, cval1
, maxval
, cval2
, maxval
),
6810 = fold (build (code
, type
,
6811 eval_subst (arg0
, cval1
, minval
, cval2
, maxval
),
6814 /* All three of these results should be 0 or 1. Confirm they
6815 are. Then use those values to select the proper code
6818 if ((integer_zerop (high_result
)
6819 || integer_onep (high_result
))
6820 && (integer_zerop (equal_result
)
6821 || integer_onep (equal_result
))
6822 && (integer_zerop (low_result
)
6823 || integer_onep (low_result
)))
6825 /* Make a 3-bit mask with the high-order bit being the
6826 value for `>', the next for '=', and the low for '<'. */
6827 switch ((integer_onep (high_result
) * 4)
6828 + (integer_onep (equal_result
) * 2)
6829 + integer_onep (low_result
))
6833 return omit_one_operand (type
, integer_zero_node
, arg0
);
6854 return omit_one_operand (type
, integer_one_node
, arg0
);
6857 t
= build (code
, type
, cval1
, cval2
);
6859 return save_expr (t
);
6866 /* If this is a comparison of a field, we may be able to simplify it. */
6867 if ((TREE_CODE (arg0
) == COMPONENT_REF
6868 || TREE_CODE (arg0
) == BIT_FIELD_REF
)
6869 && (code
== EQ_EXPR
|| code
== NE_EXPR
)
6870 /* Handle the constant case even without -O
6871 to make sure the warnings are given. */
6872 && (optimize
|| TREE_CODE (arg1
) == INTEGER_CST
))
6874 t1
= optimize_bit_field_compare (code
, type
, arg0
, arg1
);
6878 /* If this is a comparison of complex values and either or both sides
6879 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6880 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6881 This may prevent needless evaluations. */
6882 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6883 && TREE_CODE (TREE_TYPE (arg0
)) == COMPLEX_TYPE
6884 && (TREE_CODE (arg0
) == COMPLEX_EXPR
6885 || TREE_CODE (arg1
) == COMPLEX_EXPR
6886 || TREE_CODE (arg0
) == COMPLEX_CST
6887 || TREE_CODE (arg1
) == COMPLEX_CST
))
6889 tree subtype
= TREE_TYPE (TREE_TYPE (arg0
));
6890 tree real0
, imag0
, real1
, imag1
;
6892 arg0
= save_expr (arg0
);
6893 arg1
= save_expr (arg1
);
6894 real0
= fold (build1 (REALPART_EXPR
, subtype
, arg0
));
6895 imag0
= fold (build1 (IMAGPART_EXPR
, subtype
, arg0
));
6896 real1
= fold (build1 (REALPART_EXPR
, subtype
, arg1
));
6897 imag1
= fold (build1 (IMAGPART_EXPR
, subtype
, arg1
));
6899 return fold (build ((code
== EQ_EXPR
? TRUTH_ANDIF_EXPR
6902 fold (build (code
, type
, real0
, real1
)),
6903 fold (build (code
, type
, imag0
, imag1
))));
6906 /* Optimize comparisons of strlen vs zero to a compare of the
6907 first character of the string vs zero. To wit,
6908 strlen(ptr) == 0 => *ptr == 0
6909 strlen(ptr) != 0 => *ptr != 0
6910 Other cases should reduce to one of these two (or a constant)
6911 due to the return value of strlen being unsigned. */
6912 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6913 && integer_zerop (arg1
)
6914 && TREE_CODE (arg0
) == CALL_EXPR
6915 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == ADDR_EXPR
)
6917 tree fndecl
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
6920 if (TREE_CODE (fndecl
) == FUNCTION_DECL
6921 && DECL_BUILT_IN (fndecl
)
6922 && DECL_BUILT_IN_CLASS (fndecl
) != BUILT_IN_MD
6923 && DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STRLEN
6924 && (arglist
= TREE_OPERAND (arg0
, 1))
6925 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist
))) == POINTER_TYPE
6926 && ! TREE_CHAIN (arglist
))
6927 return fold (build (code
, type
,
6928 build1 (INDIRECT_REF
, char_type_node
,
6929 TREE_VALUE(arglist
)),
6930 integer_zero_node
));
6933 /* From here on, the only cases we handle are when the result is
6934 known to be a constant.
6936 To compute GT, swap the arguments and do LT.
6937 To compute GE, do LT and invert the result.
6938 To compute LE, swap the arguments, do LT and invert the result.
6939 To compute NE, do EQ and invert the result.
6941 Therefore, the code below must handle only EQ and LT. */
6943 if (code
== LE_EXPR
|| code
== GT_EXPR
)
6945 tem
= arg0
, arg0
= arg1
, arg1
= tem
;
6946 code
= swap_tree_comparison (code
);
6949 /* Note that it is safe to invert for real values here because we
6950 will check below in the one case that it matters. */
6954 if (code
== NE_EXPR
|| code
== GE_EXPR
)
6957 code
= invert_tree_comparison (code
);
6960 /* Compute a result for LT or EQ if args permit;
6961 otherwise return T. */
6962 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
6964 if (code
== EQ_EXPR
)
6965 t1
= build_int_2 (tree_int_cst_equal (arg0
, arg1
), 0);
6967 t1
= build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0
))
6968 ? INT_CST_LT_UNSIGNED (arg0
, arg1
)
6969 : INT_CST_LT (arg0
, arg1
)),
6973 #if 0 /* This is no longer useful, but breaks some real code. */
6974 /* Assume a nonexplicit constant cannot equal an explicit one,
6975 since such code would be undefined anyway.
6976 Exception: on sysvr4, using #pragma weak,
6977 a label can come out as 0. */
6978 else if (TREE_CODE (arg1
) == INTEGER_CST
6979 && !integer_zerop (arg1
)
6980 && TREE_CONSTANT (arg0
)
6981 && TREE_CODE (arg0
) == ADDR_EXPR
6983 t1
= build_int_2 (0, 0);
6985 /* Two real constants can be compared explicitly. */
6986 else if (TREE_CODE (arg0
) == REAL_CST
&& TREE_CODE (arg1
) == REAL_CST
)
6988 /* If either operand is a NaN, the result is false with two
6989 exceptions: First, an NE_EXPR is true on NaNs, but that case
6990 is already handled correctly since we will be inverting the
6991 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6992 or a GE_EXPR into a LT_EXPR, we must return true so that it
6993 will be inverted into false. */
6995 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0
))
6996 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
6997 t1
= build_int_2 (invert
&& code
== LT_EXPR
, 0);
6999 else if (code
== EQ_EXPR
)
7000 t1
= build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0
),
7001 TREE_REAL_CST (arg1
)),
7004 t1
= build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0
),
7005 TREE_REAL_CST (arg1
)),
7009 if (t1
== NULL_TREE
)
7013 TREE_INT_CST_LOW (t1
) ^= 1;
7015 TREE_TYPE (t1
) = type
;
7016 if (TREE_CODE (type
) == BOOLEAN_TYPE
)
7017 return truthvalue_conversion (t1
);
7021 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
7022 so all simple results must be passed through pedantic_non_lvalue. */
7023 if (TREE_CODE (arg0
) == INTEGER_CST
)
7024 return pedantic_non_lvalue
7025 (TREE_OPERAND (t
, (integer_zerop (arg0
) ? 2 : 1)));
7026 else if (operand_equal_p (arg1
, TREE_OPERAND (expr
, 2), 0))
7027 return pedantic_omit_one_operand (type
, arg1
, arg0
);
7029 /* If the second operand is zero, invert the comparison and swap
7030 the second and third operands. Likewise if the second operand
7031 is constant and the third is not or if the third operand is
7032 equivalent to the first operand of the comparison. */
7034 if (integer_zerop (arg1
)
7035 || (TREE_CONSTANT (arg1
) && ! TREE_CONSTANT (TREE_OPERAND (t
, 2)))
7036 || (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
7037 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
7038 TREE_OPERAND (t
, 2),
7039 TREE_OPERAND (arg0
, 1))))
7041 /* See if this can be inverted. If it can't, possibly because
7042 it was a floating-point inequality comparison, don't do
7044 tem
= invert_truthvalue (arg0
);
7046 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
7048 t
= build (code
, type
, tem
,
7049 TREE_OPERAND (t
, 2), TREE_OPERAND (t
, 1));
7051 /* arg1 should be the first argument of the new T. */
7052 arg1
= TREE_OPERAND (t
, 1);
7057 /* If we have A op B ? A : C, we may be able to convert this to a
7058 simpler expression, depending on the operation and the values
7059 of B and C. IEEE floating point prevents this though,
7060 because A or B might be -0.0 or a NaN. */
7062 if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
7063 && (TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
7064 || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0
, 0)))
7065 || flag_unsafe_math_optimizations
)
7066 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
7067 arg1
, TREE_OPERAND (arg0
, 1)))
7069 tree arg2
= TREE_OPERAND (t
, 2);
7070 enum tree_code comp_code
= TREE_CODE (arg0
);
7074 /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
7075 depending on the comparison operation. */
7076 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0
, 1)))
7077 ? real_zerop (TREE_OPERAND (arg0
, 1))
7078 : integer_zerop (TREE_OPERAND (arg0
, 1)))
7079 && TREE_CODE (arg2
) == NEGATE_EXPR
7080 && operand_equal_p (TREE_OPERAND (arg2
, 0), arg1
, 0))
7088 (convert (TREE_TYPE (TREE_OPERAND (t
, 1)),
7092 return pedantic_non_lvalue (convert (type
, arg1
));
7095 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
7096 arg1
= convert (signed_type (TREE_TYPE (arg1
)), arg1
);
7097 return pedantic_non_lvalue
7098 (convert (type
, fold (build1 (ABS_EXPR
,
7099 TREE_TYPE (arg1
), arg1
))));
7102 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
7103 arg1
= convert (signed_type (TREE_TYPE (arg1
)), arg1
);
7104 return pedantic_non_lvalue
7105 (negate_expr (convert (type
,
7106 fold (build1 (ABS_EXPR
,
7113 /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
7116 if (integer_zerop (TREE_OPERAND (arg0
, 1)) && integer_zerop (arg2
))
7118 if (comp_code
== NE_EXPR
)
7119 return pedantic_non_lvalue (convert (type
, arg1
));
7120 else if (comp_code
== EQ_EXPR
)
7121 return pedantic_non_lvalue (convert (type
, integer_zero_node
));
7124 /* If this is A op B ? A : B, this is either A, B, min (A, B),
7125 or max (A, B), depending on the operation. */
7127 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 1),
7128 arg2
, TREE_OPERAND (arg0
, 0)))
7130 tree comp_op0
= TREE_OPERAND (arg0
, 0);
7131 tree comp_op1
= TREE_OPERAND (arg0
, 1);
7132 tree comp_type
= TREE_TYPE (comp_op0
);
7134 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
7135 if (TYPE_MAIN_VARIANT (comp_type
) == TYPE_MAIN_VARIANT (type
))
7141 return pedantic_non_lvalue (convert (type
, arg2
));
7143 return pedantic_non_lvalue (convert (type
, arg1
));
7146 /* In C++ a ?: expression can be an lvalue, so put the
7147 operand which will be used if they are equal first
7148 so that we can convert this back to the
7149 corresponding COND_EXPR. */
7150 return pedantic_non_lvalue
7151 (convert (type
, fold (build (MIN_EXPR
, comp_type
,
7152 (comp_code
== LE_EXPR
7153 ? comp_op0
: comp_op1
),
7154 (comp_code
== LE_EXPR
7155 ? comp_op1
: comp_op0
)))));
7159 return pedantic_non_lvalue
7160 (convert (type
, fold (build (MAX_EXPR
, comp_type
,
7161 (comp_code
== GE_EXPR
7162 ? comp_op0
: comp_op1
),
7163 (comp_code
== GE_EXPR
7164 ? comp_op1
: comp_op0
)))));
7171 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
7172 we might still be able to simplify this. For example,
7173 if C1 is one less or one more than C2, this might have started
7174 out as a MIN or MAX and been transformed by this function.
7175 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
7177 if (INTEGRAL_TYPE_P (type
)
7178 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
7179 && TREE_CODE (arg2
) == INTEGER_CST
)
7183 /* We can replace A with C1 in this case. */
7184 arg1
= convert (type
, TREE_OPERAND (arg0
, 1));
7185 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
,
7186 TREE_OPERAND (t
, 2));
7190 /* If C1 is C2 + 1, this is min(A, C2). */
7191 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
7192 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7193 const_binop (PLUS_EXPR
, arg2
,
7194 integer_one_node
, 0), 1))
7195 return pedantic_non_lvalue
7196 (fold (build (MIN_EXPR
, type
, arg1
, arg2
)));
7200 /* If C1 is C2 - 1, this is min(A, C2). */
7201 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
7202 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7203 const_binop (MINUS_EXPR
, arg2
,
7204 integer_one_node
, 0), 1))
7205 return pedantic_non_lvalue
7206 (fold (build (MIN_EXPR
, type
, arg1
, arg2
)));
7210 /* If C1 is C2 - 1, this is max(A, C2). */
7211 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
7212 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7213 const_binop (MINUS_EXPR
, arg2
,
7214 integer_one_node
, 0), 1))
7215 return pedantic_non_lvalue
7216 (fold (build (MAX_EXPR
, type
, arg1
, arg2
)));
7220 /* If C1 is C2 + 1, this is max(A, C2). */
7221 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
7222 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7223 const_binop (PLUS_EXPR
, arg2
,
7224 integer_one_node
, 0), 1))
7225 return pedantic_non_lvalue
7226 (fold (build (MAX_EXPR
, type
, arg1
, arg2
)));
7235 /* If the second operand is simpler than the third, swap them
7236 since that produces better jump optimization results. */
7237 if ((TREE_CONSTANT (arg1
) || DECL_P (arg1
)
7238 || TREE_CODE (arg1
) == SAVE_EXPR
)
7239 && ! (TREE_CONSTANT (TREE_OPERAND (t
, 2))
7240 || DECL_P (TREE_OPERAND (t
, 2))
7241 || TREE_CODE (TREE_OPERAND (t
, 2)) == SAVE_EXPR
))
7243 /* See if this can be inverted. If it can't, possibly because
7244 it was a floating-point inequality comparison, don't do
7246 tem
= invert_truthvalue (arg0
);
7248 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
7250 t
= build (code
, type
, tem
,
7251 TREE_OPERAND (t
, 2), TREE_OPERAND (t
, 1));
7253 /* arg1 should be the first argument of the new T. */
7254 arg1
= TREE_OPERAND (t
, 1);
7259 /* Convert A ? 1 : 0 to simply A. */
7260 if (integer_onep (TREE_OPERAND (t
, 1))
7261 && integer_zerop (TREE_OPERAND (t
, 2))
7262 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7263 call to fold will try to move the conversion inside
7264 a COND, which will recurse. In that case, the COND_EXPR
7265 is probably the best choice, so leave it alone. */
7266 && type
== TREE_TYPE (arg0
))
7267 return pedantic_non_lvalue (arg0
);
7269 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7270 operation is simply A & 2. */
7272 if (integer_zerop (TREE_OPERAND (t
, 2))
7273 && TREE_CODE (arg0
) == NE_EXPR
7274 && integer_zerop (TREE_OPERAND (arg0
, 1))
7275 && integer_pow2p (arg1
)
7276 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == BIT_AND_EXPR
7277 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1),
7279 return pedantic_non_lvalue (convert (type
, TREE_OPERAND (arg0
, 0)));
7284 /* When pedantic, a compound expression can be neither an lvalue
7285 nor an integer constant expression. */
7286 if (TREE_SIDE_EFFECTS (arg0
) || pedantic
)
7288 /* Don't let (0, 0) be null pointer constant. */
7289 if (integer_zerop (arg1
))
7290 return build1 (NOP_EXPR
, type
, arg1
);
7291 return convert (type
, arg1
);
7295 return build_complex (type
, arg0
, arg1
);
7299 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
7301 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
7302 return omit_one_operand (type
, TREE_OPERAND (arg0
, 0),
7303 TREE_OPERAND (arg0
, 1));
7304 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
7305 return TREE_REALPART (arg0
);
7306 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
7307 return fold (build (TREE_CODE (arg0
), type
,
7308 fold (build1 (REALPART_EXPR
, type
,
7309 TREE_OPERAND (arg0
, 0))),
7310 fold (build1 (REALPART_EXPR
,
7311 type
, TREE_OPERAND (arg0
, 1)))));
7315 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
7316 return convert (type
, integer_zero_node
);
7317 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
7318 return omit_one_operand (type
, TREE_OPERAND (arg0
, 1),
7319 TREE_OPERAND (arg0
, 0));
7320 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
7321 return TREE_IMAGPART (arg0
);
7322 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
7323 return fold (build (TREE_CODE (arg0
), type
,
7324 fold (build1 (IMAGPART_EXPR
, type
,
7325 TREE_OPERAND (arg0
, 0))),
7326 fold (build1 (IMAGPART_EXPR
, type
,
7327 TREE_OPERAND (arg0
, 1)))));
7330 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7332 case CLEANUP_POINT_EXPR
:
7333 if (! has_cleanups (arg0
))
7334 return TREE_OPERAND (t
, 0);
7337 enum tree_code code0
= TREE_CODE (arg0
);
7338 int kind0
= TREE_CODE_CLASS (code0
);
7339 tree arg00
= TREE_OPERAND (arg0
, 0);
7342 if (kind0
== '1' || code0
== TRUTH_NOT_EXPR
)
7343 return fold (build1 (code0
, type
,
7344 fold (build1 (CLEANUP_POINT_EXPR
,
7345 TREE_TYPE (arg00
), arg00
))));
7347 if (kind0
== '<' || kind0
== '2'
7348 || code0
== TRUTH_ANDIF_EXPR
|| code0
== TRUTH_ORIF_EXPR
7349 || code0
== TRUTH_AND_EXPR
|| code0
== TRUTH_OR_EXPR
7350 || code0
== TRUTH_XOR_EXPR
)
7352 arg01
= TREE_OPERAND (arg0
, 1);
7354 if (TREE_CONSTANT (arg00
)
7355 || ((code0
== TRUTH_ANDIF_EXPR
|| code0
== TRUTH_ORIF_EXPR
)
7356 && ! has_cleanups (arg00
)))
7357 return fold (build (code0
, type
, arg00
,
7358 fold (build1 (CLEANUP_POINT_EXPR
,
7359 TREE_TYPE (arg01
), arg01
))));
7361 if (TREE_CONSTANT (arg01
))
7362 return fold (build (code0
, type
,
7363 fold (build1 (CLEANUP_POINT_EXPR
,
7364 TREE_TYPE (arg00
), arg00
)),
7372 /* Check for a built-in function. */
7373 if (TREE_CODE (TREE_OPERAND (expr
, 0)) == ADDR_EXPR
7374 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr
, 0), 0))
7376 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr
, 0), 0)))
7378 tree tmp
= fold_builtin (expr
);
7386 } /* switch (code) */
7389 /* Determine if first argument is a multiple of second argument. Return 0 if
7390 it is not, or we cannot easily determined it to be.
7392 An example of the sort of thing we care about (at this point; this routine
7393 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7394 fold cases do now) is discovering that
7396 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7402 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7404 This code also handles discovering that
7406 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7408 is a multiple of 8 so we don't have to worry about dealing with a
7411 Note that we *look* inside a SAVE_EXPR only to determine how it was
7412 calculated; it is not safe for fold to do much of anything else with the
7413 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7414 at run time. For example, the latter example above *cannot* be implemented
7415 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7416 evaluation time of the original SAVE_EXPR is not necessarily the same at
7417 the time the new expression is evaluated. The only optimization of this
7418 sort that would be valid is changing
7420 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7424 SAVE_EXPR (I) * SAVE_EXPR (J)
7426 (where the same SAVE_EXPR (J) is used in the original and the
7427 transformed version). */
7430 multiple_of_p (type
, top
, bottom
)
7435 if (operand_equal_p (top
, bottom
, 0))
7438 if (TREE_CODE (type
) != INTEGER_TYPE
)
7441 switch (TREE_CODE (top
))
7444 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
7445 || multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
7449 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
7450 && multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
7453 if (TREE_CODE (TREE_OPERAND (top
, 1)) == INTEGER_CST
)
7457 op1
= TREE_OPERAND (top
, 1);
7458 /* const_binop may not detect overflow correctly,
7459 so check for it explicitly here. */
7460 if (TYPE_PRECISION (TREE_TYPE (size_one_node
))
7461 > TREE_INT_CST_LOW (op1
)
7462 && TREE_INT_CST_HIGH (op1
) == 0
7463 && 0 != (t1
= convert (type
,
7464 const_binop (LSHIFT_EXPR
, size_one_node
,
7466 && ! TREE_OVERFLOW (t1
))
7467 return multiple_of_p (type
, t1
, bottom
);
7472 /* Can't handle conversions from non-integral or wider integral type. */
7473 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top
, 0))) != INTEGER_TYPE
)
7474 || (TYPE_PRECISION (type
)
7475 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top
, 0)))))
7478 /* .. fall through ... */
7481 return multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
);
7484 if (TREE_CODE (bottom
) != INTEGER_CST
7485 || (TREE_UNSIGNED (type
)
7486 && (tree_int_cst_sgn (top
) < 0
7487 || tree_int_cst_sgn (bottom
) < 0)))
7489 return integer_zerop (const_binop (TRUNC_MOD_EXPR
,
7497 /* Return true if `t' is known to be non-negative. */
7500 tree_expr_nonnegative_p (t
)
7503 switch (TREE_CODE (t
))
7509 return tree_int_cst_sgn (t
) >= 0;
7510 case TRUNC_DIV_EXPR
:
7512 case FLOOR_DIV_EXPR
:
7513 case ROUND_DIV_EXPR
:
7514 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
7515 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7516 case TRUNC_MOD_EXPR
:
7518 case FLOOR_MOD_EXPR
:
7519 case ROUND_MOD_EXPR
:
7520 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
7522 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1))
7523 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 2));
7525 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7527 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
7528 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7530 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
7531 || tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7533 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7535 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7537 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
7538 case NON_LVALUE_EXPR
:
7539 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
7541 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t
));
7544 if (truth_value_p (TREE_CODE (t
)))
7545 /* Truth values evaluate to 0 or 1, which is nonnegative. */
7548 /* We don't know sign of `t', so be conservative and return false. */
7553 /* Return true if `r' is known to be non-negative.
7554 Only handles constants at the moment. */
7557 rtl_expr_nonnegative_p (r
)
7560 switch (GET_CODE (r
))
7563 return INTVAL (r
) >= 0;
7566 if (GET_MODE (r
) == VOIDmode
)
7567 return CONST_DOUBLE_HIGH (r
) >= 0;
7572 /* These are always nonnegative. */