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')
1173 k
= hex_value (c
& CHARMASK
);
1175 if ((high
& 0xf0000000) == 0)
1177 high
= (high
<< 4) + ((low
>> 28) & 15);
1178 low
= (low
<< 4) + k
;
1185 /* Record nonzero lost bits. */
1198 else if (c
== 'p' || c
== 'P')
1202 /* Sign of exponent. */
1209 /* Value of exponent.
1210 The exponent field is a decimal integer. */
1211 while (ISDIGIT (*p
))
1213 k
= (*p
++ & CHARMASK
) - '0';
1214 expon
= 10 * expon
+ k
;
1218 /* F suffix is ambiguous in the significand part
1219 so it must appear after the decimal exponent field. */
1220 if (*p
== 'f' || *p
== 'F')
1228 else if (c
== 'l' || c
== 'L')
1237 /* Abort if last character read was not legitimate. */
1239 if ((c
!= '\0' && c
!= ' ' && c
!= '\n' && c
!= '\r') || (decpt
> 1))
1242 /* There must be either one decimal point or one p. */
1243 if (decpt
== 0 && gotp
== 0)
1247 if (high
== 0 && low
== 0)
1259 /* Leave a high guard bit for carry-out. */
1260 if ((high
& 0x80000000) != 0)
1263 low
= (low
>> 1) | (high
<< 31);
1268 if ((high
& 0xffff8000) == 0)
1270 high
= (high
<< 16) + ((low
>> 16) & 0xffff);
1275 while ((high
& 0xc0000000) == 0)
1277 high
= (high
<< 1) + ((low
>> 31) & 1);
1282 if (isfloat
|| GET_MODE_SIZE (mode
) == UNITS_PER_WORD
)
1284 /* Keep 24 bits precision, bits 0x7fffff80.
1285 Rounding bit is 0x40. */
1286 lost
= lost
| low
| (high
& 0x3f);
1290 if ((high
& 0x80) || lost
)
1297 /* We need real.c to do long double formats, so here default
1298 to double precision. */
1299 #if HOST_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
1301 Keep 53 bits precision, bits 0x7fffffff fffffc00.
1302 Rounding bit is low word 0x200. */
1303 lost
= lost
| (low
& 0x1ff);
1306 if ((low
& 0x400) || lost
)
1308 low
= (low
+ 0x200) & 0xfffffc00;
1315 /* Assume it's a VAX with 56-bit significand,
1316 bits 0x7fffffff ffffff80. */
1317 lost
= lost
| (low
& 0x7f);
1320 if ((low
& 0x80) || lost
)
1322 low
= (low
+ 0x40) & 0xffffff80;
1332 ip
= REAL_VALUE_LDEXP (ip
, 32) + (double) low
;
1333 /* Apply shifts and exponent value as power of 2. */
1334 ip
= REAL_VALUE_LDEXP (ip
, expon
- (nrmcount
+ frexpon
));
1341 #endif /* no REAL_ARITHMETIC */
1343 /* Given T, an expression, return the negation of T. Allow for T to be
1344 null, in which case return null. */
1356 type
= TREE_TYPE (t
);
1357 STRIP_SIGN_NOPS (t
);
1359 switch (TREE_CODE (t
))
1363 if (! TREE_UNSIGNED (type
)
1364 && 0 != (tem
= fold (build1 (NEGATE_EXPR
, type
, t
)))
1365 && ! TREE_OVERFLOW (tem
))
1370 return convert (type
, TREE_OPERAND (t
, 0));
1373 /* - (A - B) -> B - A */
1374 if (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
1375 return convert (type
,
1376 fold (build (MINUS_EXPR
, TREE_TYPE (t
),
1377 TREE_OPERAND (t
, 1),
1378 TREE_OPERAND (t
, 0))));
1385 return convert (type
, fold (build1 (NEGATE_EXPR
, TREE_TYPE (t
), t
)));
1388 /* Split a tree IN into a constant, literal and variable parts that could be
1389 combined with CODE to make IN. "constant" means an expression with
1390 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1391 commutative arithmetic operation. Store the constant part into *CONP,
1392 the literal in &LITP and return the variable part. If a part isn't
1393 present, set it to null. If the tree does not decompose in this way,
1394 return the entire tree as the variable part and the other parts as null.
1396 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1397 case, we negate an operand that was subtracted. If NEGATE_P is true, we
1398 are negating all of IN.
1400 If IN is itself a literal or constant, return it as appropriate.
1402 Note that we do not guarantee that any of the three values will be the
1403 same type as IN, but they will have the same signedness and mode. */
1406 split_tree (in
, code
, conp
, litp
, negate_p
)
1408 enum tree_code code
;
1417 /* Strip any conversions that don't change the machine mode or signedness. */
1418 STRIP_SIGN_NOPS (in
);
1420 if (TREE_CODE (in
) == INTEGER_CST
|| TREE_CODE (in
) == REAL_CST
)
1422 else if (TREE_CODE (in
) == code
1423 || (! FLOAT_TYPE_P (TREE_TYPE (in
))
1424 /* We can associate addition and subtraction together (even
1425 though the C standard doesn't say so) for integers because
1426 the value is not affected. For reals, the value might be
1427 affected, so we can't. */
1428 && ((code
== PLUS_EXPR
&& TREE_CODE (in
) == MINUS_EXPR
)
1429 || (code
== MINUS_EXPR
&& TREE_CODE (in
) == PLUS_EXPR
))))
1431 tree op0
= TREE_OPERAND (in
, 0);
1432 tree op1
= TREE_OPERAND (in
, 1);
1433 int neg1_p
= TREE_CODE (in
) == MINUS_EXPR
;
1434 int neg_litp_p
= 0, neg_conp_p
= 0, neg_var_p
= 0;
1436 /* First see if either of the operands is a literal, then a constant. */
1437 if (TREE_CODE (op0
) == INTEGER_CST
|| TREE_CODE (op0
) == REAL_CST
)
1438 *litp
= op0
, op0
= 0;
1439 else if (TREE_CODE (op1
) == INTEGER_CST
|| TREE_CODE (op1
) == REAL_CST
)
1440 *litp
= op1
, neg_litp_p
= neg1_p
, op1
= 0;
1442 if (op0
!= 0 && TREE_CONSTANT (op0
))
1443 *conp
= op0
, op0
= 0;
1444 else if (op1
!= 0 && TREE_CONSTANT (op1
))
1445 *conp
= op1
, neg_conp_p
= neg1_p
, op1
= 0;
1447 /* If we haven't dealt with either operand, this is not a case we can
1448 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1449 if (op0
!= 0 && op1
!= 0)
1454 var
= op1
, neg_var_p
= neg1_p
;
1456 /* Now do any needed negations. */
1457 if (neg_litp_p
) *litp
= negate_expr (*litp
);
1458 if (neg_conp_p
) *conp
= negate_expr (*conp
);
1459 if (neg_var_p
) var
= negate_expr (var
);
1461 else if (TREE_CONSTANT (in
))
1468 var
= negate_expr (var
);
1469 *conp
= negate_expr (*conp
);
1470 *litp
= negate_expr (*litp
);
1476 /* Re-associate trees split by the above function. T1 and T2 are either
1477 expressions to associate or null. Return the new expression, if any. If
1478 we build an operation, do it in TYPE and with CODE, except if CODE is a
1479 MINUS_EXPR, in which case we use PLUS_EXPR since split_tree will already
1480 have taken care of the negations. */
1483 associate_trees (t1
, t2
, code
, type
)
1485 enum tree_code code
;
1493 if (code
== MINUS_EXPR
)
1496 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1497 try to fold this since we will have infinite recursion. But do
1498 deal with any NEGATE_EXPRs. */
1499 if (TREE_CODE (t1
) == code
|| TREE_CODE (t2
) == code
1500 || TREE_CODE (t1
) == MINUS_EXPR
|| TREE_CODE (t2
) == MINUS_EXPR
)
1502 if (TREE_CODE (t1
) == NEGATE_EXPR
)
1503 return build (MINUS_EXPR
, type
, convert (type
, t2
),
1504 convert (type
, TREE_OPERAND (t1
, 0)));
1505 else if (TREE_CODE (t2
) == NEGATE_EXPR
)
1506 return build (MINUS_EXPR
, type
, convert (type
, t1
),
1507 convert (type
, TREE_OPERAND (t2
, 0)));
1509 return build (code
, type
, convert (type
, t1
), convert (type
, t2
));
1512 return fold (build (code
, type
, convert (type
, t1
), convert (type
, t2
)));
1515 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1516 to produce a new constant.
1518 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1521 int_const_binop (code
, arg1
, arg2
, notrunc
)
1522 enum tree_code code
;
1526 unsigned HOST_WIDE_INT int1l
, int2l
;
1527 HOST_WIDE_INT int1h
, int2h
;
1528 unsigned HOST_WIDE_INT low
;
1530 unsigned HOST_WIDE_INT garbagel
;
1531 HOST_WIDE_INT garbageh
;
1533 tree type
= TREE_TYPE (arg1
);
1534 int uns
= TREE_UNSIGNED (type
);
1536 = (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
));
1538 int no_overflow
= 0;
1540 int1l
= TREE_INT_CST_LOW (arg1
);
1541 int1h
= TREE_INT_CST_HIGH (arg1
);
1542 int2l
= TREE_INT_CST_LOW (arg2
);
1543 int2h
= TREE_INT_CST_HIGH (arg2
);
1548 low
= int1l
| int2l
, hi
= int1h
| int2h
;
1552 low
= int1l
^ int2l
, hi
= int1h
^ int2h
;
1556 low
= int1l
& int2l
, hi
= int1h
& int2h
;
1559 case BIT_ANDTC_EXPR
:
1560 low
= int1l
& ~int2l
, hi
= int1h
& ~int2h
;
1566 /* It's unclear from the C standard whether shifts can overflow.
1567 The following code ignores overflow; perhaps a C standard
1568 interpretation ruling is needed. */
1569 lshift_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1577 lrotate_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1582 overflow
= add_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1586 neg_double (int2l
, int2h
, &low
, &hi
);
1587 add_double (int1l
, int1h
, low
, hi
, &low
, &hi
);
1588 overflow
= OVERFLOW_SUM_SIGN (hi
, int2h
, int1h
);
1592 overflow
= mul_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1595 case TRUNC_DIV_EXPR
:
1596 case FLOOR_DIV_EXPR
: case CEIL_DIV_EXPR
:
1597 case EXACT_DIV_EXPR
:
1598 /* This is a shortcut for a common special case. */
1599 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1600 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1601 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1602 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1604 if (code
== CEIL_DIV_EXPR
)
1607 low
= int1l
/ int2l
, hi
= 0;
1611 /* ... fall through ... */
1613 case ROUND_DIV_EXPR
:
1614 if (int2h
== 0 && int2l
== 1)
1616 low
= int1l
, hi
= int1h
;
1619 if (int1l
== int2l
&& int1h
== int2h
1620 && ! (int1l
== 0 && int1h
== 0))
1625 overflow
= div_and_round_double (code
, uns
, int1l
, int1h
, int2l
, int2h
,
1626 &low
, &hi
, &garbagel
, &garbageh
);
1629 case TRUNC_MOD_EXPR
:
1630 case FLOOR_MOD_EXPR
: case CEIL_MOD_EXPR
:
1631 /* This is a shortcut for a common special case. */
1632 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1633 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1634 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1635 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1637 if (code
== CEIL_MOD_EXPR
)
1639 low
= int1l
% int2l
, hi
= 0;
1643 /* ... fall through ... */
1645 case ROUND_MOD_EXPR
:
1646 overflow
= div_and_round_double (code
, uns
,
1647 int1l
, int1h
, int2l
, int2h
,
1648 &garbagel
, &garbageh
, &low
, &hi
);
1654 low
= (((unsigned HOST_WIDE_INT
) int1h
1655 < (unsigned HOST_WIDE_INT
) int2h
)
1656 || (((unsigned HOST_WIDE_INT
) int1h
1657 == (unsigned HOST_WIDE_INT
) int2h
)
1660 low
= (int1h
< int2h
1661 || (int1h
== int2h
&& int1l
< int2l
));
1663 if (low
== (code
== MIN_EXPR
))
1664 low
= int1l
, hi
= int1h
;
1666 low
= int2l
, hi
= int2h
;
1673 /* If this is for a sizetype, can be represented as one (signed)
1674 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1677 && ((hi
== 0 && (HOST_WIDE_INT
) low
>= 0)
1678 || (hi
== -1 && (HOST_WIDE_INT
) low
< 0))
1679 && overflow
== 0 && ! TREE_OVERFLOW (arg1
) && ! TREE_OVERFLOW (arg2
))
1680 return size_int_type_wide (low
, type
);
1683 t
= build_int_2 (low
, hi
);
1684 TREE_TYPE (t
) = TREE_TYPE (arg1
);
1689 ? (!uns
|| is_sizetype
) && overflow
1690 : (force_fit_type (t
, (!uns
|| is_sizetype
) && overflow
)
1692 | TREE_OVERFLOW (arg1
)
1693 | TREE_OVERFLOW (arg2
));
1695 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1696 So check if force_fit_type truncated the value. */
1698 && ! TREE_OVERFLOW (t
)
1699 && (TREE_INT_CST_HIGH (t
) != hi
1700 || TREE_INT_CST_LOW (t
) != low
))
1701 TREE_OVERFLOW (t
) = 1;
1703 TREE_CONSTANT_OVERFLOW (t
) = (TREE_OVERFLOW (t
)
1704 | TREE_CONSTANT_OVERFLOW (arg1
)
1705 | TREE_CONSTANT_OVERFLOW (arg2
));
1709 /* Define input and output argument for const_binop_1. */
1712 enum tree_code code
; /* Input: tree code for operation. */
1713 tree type
; /* Input: tree type for operation. */
1714 REAL_VALUE_TYPE d1
, d2
; /* Input: floating point operands. */
1715 tree t
; /* Output: constant for result. */
1718 /* Do the real arithmetic for const_binop while protected by a
1719 float overflow handler. */
1722 const_binop_1 (data
)
1725 struct cb_args
*args
= (struct cb_args
*) data
;
1726 REAL_VALUE_TYPE value
;
1728 #ifdef REAL_ARITHMETIC
1729 REAL_ARITHMETIC (value
, args
->code
, args
->d1
, args
->d2
);
1734 value
= args
->d1
+ args
->d2
;
1738 value
= args
->d1
- args
->d2
;
1742 value
= args
->d1
* args
->d2
;
1746 #ifndef REAL_INFINITY
1751 value
= args
->d1
/ args
->d2
;
1755 value
= MIN (args
->d1
, args
->d2
);
1759 value
= MAX (args
->d1
, args
->d2
);
1765 #endif /* no REAL_ARITHMETIC */
1768 = build_real (args
->type
,
1769 real_value_truncate (TYPE_MODE (args
->type
), value
));
1772 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1773 constant. We assume ARG1 and ARG2 have the same data type, or at least
1774 are the same kind of constant and the same machine mode.
1776 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1779 const_binop (code
, arg1
, arg2
, notrunc
)
1780 enum tree_code code
;
1787 if (TREE_CODE (arg1
) == INTEGER_CST
)
1788 return int_const_binop (code
, arg1
, arg2
, notrunc
);
1790 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1791 if (TREE_CODE (arg1
) == REAL_CST
)
1797 struct cb_args args
;
1799 d1
= TREE_REAL_CST (arg1
);
1800 d2
= TREE_REAL_CST (arg2
);
1802 /* If either operand is a NaN, just return it. Otherwise, set up
1803 for floating-point trap; we return an overflow. */
1804 if (REAL_VALUE_ISNAN (d1
))
1806 else if (REAL_VALUE_ISNAN (d2
))
1809 /* Setup input for const_binop_1() */
1810 args
.type
= TREE_TYPE (arg1
);
1815 if (do_float_handler (const_binop_1
, (PTR
) &args
))
1816 /* Receive output from const_binop_1. */
1820 /* We got an exception from const_binop_1. */
1821 t
= copy_node (arg1
);
1826 = (force_fit_type (t
, overflow
)
1827 | TREE_OVERFLOW (arg1
) | TREE_OVERFLOW (arg2
));
1828 TREE_CONSTANT_OVERFLOW (t
)
1830 | TREE_CONSTANT_OVERFLOW (arg1
)
1831 | TREE_CONSTANT_OVERFLOW (arg2
);
1834 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1835 if (TREE_CODE (arg1
) == COMPLEX_CST
)
1837 tree type
= TREE_TYPE (arg1
);
1838 tree r1
= TREE_REALPART (arg1
);
1839 tree i1
= TREE_IMAGPART (arg1
);
1840 tree r2
= TREE_REALPART (arg2
);
1841 tree i2
= TREE_IMAGPART (arg2
);
1847 t
= build_complex (type
,
1848 const_binop (PLUS_EXPR
, r1
, r2
, notrunc
),
1849 const_binop (PLUS_EXPR
, i1
, i2
, notrunc
));
1853 t
= build_complex (type
,
1854 const_binop (MINUS_EXPR
, r1
, r2
, notrunc
),
1855 const_binop (MINUS_EXPR
, i1
, i2
, notrunc
));
1859 t
= build_complex (type
,
1860 const_binop (MINUS_EXPR
,
1861 const_binop (MULT_EXPR
,
1863 const_binop (MULT_EXPR
,
1866 const_binop (PLUS_EXPR
,
1867 const_binop (MULT_EXPR
,
1869 const_binop (MULT_EXPR
,
1877 = const_binop (PLUS_EXPR
,
1878 const_binop (MULT_EXPR
, r2
, r2
, notrunc
),
1879 const_binop (MULT_EXPR
, i2
, i2
, notrunc
),
1882 t
= build_complex (type
,
1884 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1885 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1886 const_binop (PLUS_EXPR
,
1887 const_binop (MULT_EXPR
, r1
, r2
,
1889 const_binop (MULT_EXPR
, i1
, i2
,
1892 magsquared
, notrunc
),
1894 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1895 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1896 const_binop (MINUS_EXPR
,
1897 const_binop (MULT_EXPR
, i1
, r2
,
1899 const_binop (MULT_EXPR
, r1
, i2
,
1902 magsquared
, notrunc
));
1914 /* These are the hash table functions for the hash table of INTEGER_CST
1915 nodes of a sizetype. */
1917 /* Return the hash code code X, an INTEGER_CST. */
1925 return (TREE_INT_CST_HIGH (t
) ^ TREE_INT_CST_LOW (t
)
1926 ^ (hashval_t
) ((long) TREE_TYPE (t
) >> 3)
1927 ^ (TREE_OVERFLOW (t
) << 20));
1930 /* Return non-zero if the value represented by *X (an INTEGER_CST tree node)
1931 is the same as that given by *Y, which is the same. */
1941 return (TREE_INT_CST_HIGH (xt
) == TREE_INT_CST_HIGH (yt
)
1942 && TREE_INT_CST_LOW (xt
) == TREE_INT_CST_LOW (yt
)
1943 && TREE_TYPE (xt
) == TREE_TYPE (yt
)
1944 && TREE_OVERFLOW (xt
) == TREE_OVERFLOW (yt
));
1947 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1948 bits are given by NUMBER and of the sizetype represented by KIND. */
1951 size_int_wide (number
, kind
)
1952 HOST_WIDE_INT number
;
1953 enum size_type_kind kind
;
1955 return size_int_type_wide (number
, sizetype_tab
[(int) kind
]);
1958 /* Likewise, but the desired type is specified explicitly. */
1961 size_int_type_wide (number
, type
)
1962 HOST_WIDE_INT number
;
1965 static htab_t size_htab
= 0;
1966 static tree new_const
= 0;
1971 size_htab
= htab_create (1024, size_htab_hash
, size_htab_eq
, NULL
);
1972 ggc_add_deletable_htab (size_htab
, NULL
, NULL
);
1973 new_const
= make_node (INTEGER_CST
);
1974 ggc_add_tree_root (&new_const
, 1);
1977 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1978 hash table, we return the value from the hash table. Otherwise, we
1979 place that in the hash table and make a new node for the next time. */
1980 TREE_INT_CST_LOW (new_const
) = number
;
1981 TREE_INT_CST_HIGH (new_const
) = number
< 0 ? -1 : 0;
1982 TREE_TYPE (new_const
) = type
;
1983 TREE_OVERFLOW (new_const
) = TREE_CONSTANT_OVERFLOW (new_const
)
1984 = force_fit_type (new_const
, 0);
1986 slot
= htab_find_slot (size_htab
, new_const
, INSERT
);
1991 *slot
= (PTR
) new_const
;
1992 new_const
= make_node (INTEGER_CST
);
1996 return (tree
) *slot
;
1999 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
2000 is a tree code. The type of the result is taken from the operands.
2001 Both must be the same type integer type and it must be a size type.
2002 If the operands are constant, so is the result. */
2005 size_binop (code
, arg0
, arg1
)
2006 enum tree_code code
;
2009 tree type
= TREE_TYPE (arg0
);
2011 if (TREE_CODE (type
) != INTEGER_TYPE
|| ! TYPE_IS_SIZETYPE (type
)
2012 || type
!= TREE_TYPE (arg1
))
2015 /* Handle the special case of two integer constants faster. */
2016 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
2018 /* And some specific cases even faster than that. */
2019 if (code
== PLUS_EXPR
&& integer_zerop (arg0
))
2021 else if ((code
== MINUS_EXPR
|| code
== PLUS_EXPR
)
2022 && integer_zerop (arg1
))
2024 else if (code
== MULT_EXPR
&& integer_onep (arg0
))
2027 /* Handle general case of two integer constants. */
2028 return int_const_binop (code
, arg0
, arg1
, 0);
2031 if (arg0
== error_mark_node
|| arg1
== error_mark_node
)
2032 return error_mark_node
;
2034 return fold (build (code
, type
, arg0
, arg1
));
2037 /* Given two values, either both of sizetype or both of bitsizetype,
2038 compute the difference between the two values. Return the value
2039 in signed type corresponding to the type of the operands. */
2042 size_diffop (arg0
, arg1
)
2045 tree type
= TREE_TYPE (arg0
);
2048 if (TREE_CODE (type
) != INTEGER_TYPE
|| ! TYPE_IS_SIZETYPE (type
)
2049 || type
!= TREE_TYPE (arg1
))
2052 /* If the type is already signed, just do the simple thing. */
2053 if (! TREE_UNSIGNED (type
))
2054 return size_binop (MINUS_EXPR
, arg0
, arg1
);
2056 ctype
= (type
== bitsizetype
|| type
== ubitsizetype
2057 ? sbitsizetype
: ssizetype
);
2059 /* If either operand is not a constant, do the conversions to the signed
2060 type and subtract. The hardware will do the right thing with any
2061 overflow in the subtraction. */
2062 if (TREE_CODE (arg0
) != INTEGER_CST
|| TREE_CODE (arg1
) != INTEGER_CST
)
2063 return size_binop (MINUS_EXPR
, convert (ctype
, arg0
),
2064 convert (ctype
, arg1
));
2066 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
2067 Otherwise, subtract the other way, convert to CTYPE (we know that can't
2068 overflow) and negate (which can't either). Special-case a result
2069 of zero while we're here. */
2070 if (tree_int_cst_equal (arg0
, arg1
))
2071 return convert (ctype
, integer_zero_node
);
2072 else if (tree_int_cst_lt (arg1
, arg0
))
2073 return convert (ctype
, size_binop (MINUS_EXPR
, arg0
, arg1
));
2075 return size_binop (MINUS_EXPR
, convert (ctype
, integer_zero_node
),
2076 convert (ctype
, size_binop (MINUS_EXPR
, arg1
, arg0
)));
2079 /* This structure is used to communicate arguments to fold_convert_1. */
2082 tree arg1
; /* Input: value to convert. */
2083 tree type
; /* Input: type to convert value to. */
2084 tree t
; /* Output: result of conversion. */
2087 /* Function to convert floating-point constants, protected by floating
2088 point exception handler. */
2091 fold_convert_1 (data
)
2094 struct fc_args
*args
= (struct fc_args
*) data
;
2096 args
->t
= build_real (args
->type
,
2097 real_value_truncate (TYPE_MODE (args
->type
),
2098 TREE_REAL_CST (args
->arg1
)));
2101 /* Given T, a tree representing type conversion of ARG1, a constant,
2102 return a constant tree representing the result of conversion. */
2105 fold_convert (t
, arg1
)
2109 tree type
= TREE_TYPE (t
);
2112 if (POINTER_TYPE_P (type
) || INTEGRAL_TYPE_P (type
))
2114 if (TREE_CODE (arg1
) == INTEGER_CST
)
2116 /* If we would build a constant wider than GCC supports,
2117 leave the conversion unfolded. */
2118 if (TYPE_PRECISION (type
) > 2 * HOST_BITS_PER_WIDE_INT
)
2121 /* If we are trying to make a sizetype for a small integer, use
2122 size_int to pick up cached types to reduce duplicate nodes. */
2123 if (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
)
2124 && !TREE_CONSTANT_OVERFLOW (arg1
)
2125 && compare_tree_int (arg1
, 10000) < 0)
2126 return size_int_type_wide (TREE_INT_CST_LOW (arg1
), type
);
2128 /* Given an integer constant, make new constant with new type,
2129 appropriately sign-extended or truncated. */
2130 t
= build_int_2 (TREE_INT_CST_LOW (arg1
),
2131 TREE_INT_CST_HIGH (arg1
));
2132 TREE_TYPE (t
) = type
;
2133 /* Indicate an overflow if (1) ARG1 already overflowed,
2134 or (2) force_fit_type indicates an overflow.
2135 Tell force_fit_type that an overflow has already occurred
2136 if ARG1 is a too-large unsigned value and T is signed.
2137 But don't indicate an overflow if converting a pointer. */
2139 = ((force_fit_type (t
,
2140 (TREE_INT_CST_HIGH (arg1
) < 0
2141 && (TREE_UNSIGNED (type
)
2142 < TREE_UNSIGNED (TREE_TYPE (arg1
)))))
2143 && ! POINTER_TYPE_P (TREE_TYPE (arg1
)))
2144 || TREE_OVERFLOW (arg1
));
2145 TREE_CONSTANT_OVERFLOW (t
)
2146 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
2148 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2149 else if (TREE_CODE (arg1
) == REAL_CST
)
2151 /* Don't initialize these, use assignments.
2152 Initialized local aggregates don't work on old compilers. */
2156 tree type1
= TREE_TYPE (arg1
);
2159 x
= TREE_REAL_CST (arg1
);
2160 l
= real_value_from_int_cst (type1
, TYPE_MIN_VALUE (type
));
2162 no_upper_bound
= (TYPE_MAX_VALUE (type
) == NULL
);
2163 if (!no_upper_bound
)
2164 u
= real_value_from_int_cst (type1
, TYPE_MAX_VALUE (type
));
2166 /* See if X will be in range after truncation towards 0.
2167 To compensate for truncation, move the bounds away from 0,
2168 but reject if X exactly equals the adjusted bounds. */
2169 #ifdef REAL_ARITHMETIC
2170 REAL_ARITHMETIC (l
, MINUS_EXPR
, l
, dconst1
);
2171 if (!no_upper_bound
)
2172 REAL_ARITHMETIC (u
, PLUS_EXPR
, u
, dconst1
);
2175 if (!no_upper_bound
)
2178 /* If X is a NaN, use zero instead and show we have an overflow.
2179 Otherwise, range check. */
2180 if (REAL_VALUE_ISNAN (x
))
2181 overflow
= 1, x
= dconst0
;
2182 else if (! (REAL_VALUES_LESS (l
, x
)
2184 && REAL_VALUES_LESS (x
, u
)))
2187 #ifndef REAL_ARITHMETIC
2189 HOST_WIDE_INT low
, high
;
2190 HOST_WIDE_INT half_word
2191 = (HOST_WIDE_INT
) 1 << (HOST_BITS_PER_WIDE_INT
/ 2);
2196 high
= (HOST_WIDE_INT
) (x
/ half_word
/ half_word
);
2197 x
-= (REAL_VALUE_TYPE
) high
* half_word
* half_word
;
2198 if (x
>= (REAL_VALUE_TYPE
) half_word
* half_word
/ 2)
2200 low
= x
- (REAL_VALUE_TYPE
) half_word
* half_word
/ 2;
2201 low
|= (HOST_WIDE_INT
) -1 << (HOST_BITS_PER_WIDE_INT
- 1);
2204 low
= (HOST_WIDE_INT
) x
;
2205 if (TREE_REAL_CST (arg1
) < 0)
2206 neg_double (low
, high
, &low
, &high
);
2207 t
= build_int_2 (low
, high
);
2211 HOST_WIDE_INT low
, high
;
2212 REAL_VALUE_TO_INT (&low
, &high
, x
);
2213 t
= build_int_2 (low
, high
);
2216 TREE_TYPE (t
) = type
;
2218 = TREE_OVERFLOW (arg1
) | force_fit_type (t
, overflow
);
2219 TREE_CONSTANT_OVERFLOW (t
)
2220 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
2222 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2223 TREE_TYPE (t
) = type
;
2225 else if (TREE_CODE (type
) == REAL_TYPE
)
2227 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2228 if (TREE_CODE (arg1
) == INTEGER_CST
)
2229 return build_real_from_int_cst (type
, arg1
);
2230 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2231 if (TREE_CODE (arg1
) == REAL_CST
)
2233 struct fc_args args
;
2235 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
2238 TREE_TYPE (arg1
) = type
;
2242 /* Setup input for fold_convert_1() */
2246 if (do_float_handler (fold_convert_1
, (PTR
) &args
))
2248 /* Receive output from fold_convert_1() */
2253 /* We got an exception from fold_convert_1() */
2255 t
= copy_node (arg1
);
2259 = TREE_OVERFLOW (arg1
) | force_fit_type (t
, overflow
);
2260 TREE_CONSTANT_OVERFLOW (t
)
2261 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
2265 TREE_CONSTANT (t
) = 1;
2269 /* Return an expr equal to X but certainly not valid as an lvalue. */
2277 /* These things are certainly not lvalues. */
2278 if (TREE_CODE (x
) == NON_LVALUE_EXPR
2279 || TREE_CODE (x
) == INTEGER_CST
2280 || TREE_CODE (x
) == REAL_CST
2281 || TREE_CODE (x
) == STRING_CST
2282 || TREE_CODE (x
) == ADDR_EXPR
)
2285 result
= build1 (NON_LVALUE_EXPR
, TREE_TYPE (x
), x
);
2286 TREE_CONSTANT (result
) = TREE_CONSTANT (x
);
2290 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2291 Zero means allow extended lvalues. */
2293 int pedantic_lvalues
;
2295 /* When pedantic, return an expr equal to X but certainly not valid as a
2296 pedantic lvalue. Otherwise, return X. */
2299 pedantic_non_lvalue (x
)
2302 if (pedantic_lvalues
)
2303 return non_lvalue (x
);
2308 /* Given a tree comparison code, return the code that is the logical inverse
2309 of the given code. It is not safe to do this for floating-point
2310 comparisons, except for NE_EXPR and EQ_EXPR. */
2312 static enum tree_code
2313 invert_tree_comparison (code
)
2314 enum tree_code code
;
2335 /* Similar, but return the comparison that results if the operands are
2336 swapped. This is safe for floating-point. */
2338 static enum tree_code
2339 swap_tree_comparison (code
)
2340 enum tree_code code
;
2360 /* Return nonzero if CODE is a tree code that represents a truth value. */
2363 truth_value_p (code
)
2364 enum tree_code code
;
2366 return (TREE_CODE_CLASS (code
) == '<'
2367 || code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
2368 || code
== TRUTH_OR_EXPR
|| code
== TRUTH_ORIF_EXPR
2369 || code
== TRUTH_XOR_EXPR
|| code
== TRUTH_NOT_EXPR
);
2372 /* Return nonzero if two operands are necessarily equal.
2373 If ONLY_CONST is non-zero, only return non-zero for constants.
2374 This function tests whether the operands are indistinguishable;
2375 it does not test whether they are equal using C's == operation.
2376 The distinction is important for IEEE floating point, because
2377 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2378 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
2381 operand_equal_p (arg0
, arg1
, only_const
)
2385 /* If both types don't have the same signedness, then we can't consider
2386 them equal. We must check this before the STRIP_NOPS calls
2387 because they may change the signedness of the arguments. */
2388 if (TREE_UNSIGNED (TREE_TYPE (arg0
)) != TREE_UNSIGNED (TREE_TYPE (arg1
)))
2394 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
2395 /* This is needed for conversions and for COMPONENT_REF.
2396 Might as well play it safe and always test this. */
2397 || TREE_CODE (TREE_TYPE (arg0
)) == ERROR_MARK
2398 || TREE_CODE (TREE_TYPE (arg1
)) == ERROR_MARK
2399 || TYPE_MODE (TREE_TYPE (arg0
)) != TYPE_MODE (TREE_TYPE (arg1
)))
2402 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2403 We don't care about side effects in that case because the SAVE_EXPR
2404 takes care of that for us. In all other cases, two expressions are
2405 equal if they have no side effects. If we have two identical
2406 expressions with side effects that should be treated the same due
2407 to the only side effects being identical SAVE_EXPR's, that will
2408 be detected in the recursive calls below. */
2409 if (arg0
== arg1
&& ! only_const
2410 && (TREE_CODE (arg0
) == SAVE_EXPR
2411 || (! TREE_SIDE_EFFECTS (arg0
) && ! TREE_SIDE_EFFECTS (arg1
))))
2414 /* Next handle constant cases, those for which we can return 1 even
2415 if ONLY_CONST is set. */
2416 if (TREE_CONSTANT (arg0
) && TREE_CONSTANT (arg1
))
2417 switch (TREE_CODE (arg0
))
2420 return (! TREE_CONSTANT_OVERFLOW (arg0
)
2421 && ! TREE_CONSTANT_OVERFLOW (arg1
)
2422 && tree_int_cst_equal (arg0
, arg1
));
2425 return (! TREE_CONSTANT_OVERFLOW (arg0
)
2426 && ! TREE_CONSTANT_OVERFLOW (arg1
)
2427 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0
),
2428 TREE_REAL_CST (arg1
)));
2431 return (operand_equal_p (TREE_REALPART (arg0
), TREE_REALPART (arg1
),
2433 && operand_equal_p (TREE_IMAGPART (arg0
), TREE_IMAGPART (arg1
),
2437 return (TREE_STRING_LENGTH (arg0
) == TREE_STRING_LENGTH (arg1
)
2438 && ! memcmp (TREE_STRING_POINTER (arg0
),
2439 TREE_STRING_POINTER (arg1
),
2440 TREE_STRING_LENGTH (arg0
)));
2443 return operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0),
2452 switch (TREE_CODE_CLASS (TREE_CODE (arg0
)))
2455 /* Two conversions are equal only if signedness and modes match. */
2456 if ((TREE_CODE (arg0
) == NOP_EXPR
|| TREE_CODE (arg0
) == CONVERT_EXPR
)
2457 && (TREE_UNSIGNED (TREE_TYPE (arg0
))
2458 != TREE_UNSIGNED (TREE_TYPE (arg1
))))
2461 return operand_equal_p (TREE_OPERAND (arg0
, 0),
2462 TREE_OPERAND (arg1
, 0), 0);
2466 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0)
2467 && operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1),
2471 /* For commutative ops, allow the other order. */
2472 return ((TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MULT_EXPR
2473 || TREE_CODE (arg0
) == MIN_EXPR
|| TREE_CODE (arg0
) == MAX_EXPR
2474 || TREE_CODE (arg0
) == BIT_IOR_EXPR
2475 || TREE_CODE (arg0
) == BIT_XOR_EXPR
2476 || TREE_CODE (arg0
) == BIT_AND_EXPR
2477 || TREE_CODE (arg0
) == NE_EXPR
|| TREE_CODE (arg0
) == EQ_EXPR
)
2478 && operand_equal_p (TREE_OPERAND (arg0
, 0),
2479 TREE_OPERAND (arg1
, 1), 0)
2480 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2481 TREE_OPERAND (arg1
, 0), 0));
2484 /* If either of the pointer (or reference) expressions we are dereferencing
2485 contain a side effect, these cannot be equal. */
2486 if (TREE_SIDE_EFFECTS (arg0
)
2487 || TREE_SIDE_EFFECTS (arg1
))
2490 switch (TREE_CODE (arg0
))
2493 return operand_equal_p (TREE_OPERAND (arg0
, 0),
2494 TREE_OPERAND (arg1
, 0), 0);
2498 case ARRAY_RANGE_REF
:
2499 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
2500 TREE_OPERAND (arg1
, 0), 0)
2501 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2502 TREE_OPERAND (arg1
, 1), 0));
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)
2509 && operand_equal_p (TREE_OPERAND (arg0
, 2),
2510 TREE_OPERAND (arg1
, 2), 0));
2516 if (TREE_CODE (arg0
) == RTL_EXPR
)
2517 return rtx_equal_p (RTL_EXPR_RTL (arg0
), RTL_EXPR_RTL (arg1
));
2525 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2526 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2528 When in doubt, return 0. */
2531 operand_equal_for_comparison_p (arg0
, arg1
, other
)
2535 int unsignedp1
, unsignedpo
;
2536 tree primarg0
, primarg1
, primother
;
2537 unsigned int correct_width
;
2539 if (operand_equal_p (arg0
, arg1
, 0))
2542 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
2543 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
2546 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2547 and see if the inner values are the same. This removes any
2548 signedness comparison, which doesn't matter here. */
2549 primarg0
= arg0
, primarg1
= arg1
;
2550 STRIP_NOPS (primarg0
);
2551 STRIP_NOPS (primarg1
);
2552 if (operand_equal_p (primarg0
, primarg1
, 0))
2555 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2556 actual comparison operand, ARG0.
2558 First throw away any conversions to wider types
2559 already present in the operands. */
2561 primarg1
= get_narrower (arg1
, &unsignedp1
);
2562 primother
= get_narrower (other
, &unsignedpo
);
2564 correct_width
= TYPE_PRECISION (TREE_TYPE (arg1
));
2565 if (unsignedp1
== unsignedpo
2566 && TYPE_PRECISION (TREE_TYPE (primarg1
)) < correct_width
2567 && TYPE_PRECISION (TREE_TYPE (primother
)) < correct_width
)
2569 tree type
= TREE_TYPE (arg0
);
2571 /* Make sure shorter operand is extended the right way
2572 to match the longer operand. */
2573 primarg1
= convert (signed_or_unsigned_type (unsignedp1
,
2574 TREE_TYPE (primarg1
)),
2577 if (operand_equal_p (arg0
, convert (type
, primarg1
), 0))
2584 /* See if ARG is an expression that is either a comparison or is performing
2585 arithmetic on comparisons. The comparisons must only be comparing
2586 two different values, which will be stored in *CVAL1 and *CVAL2; if
2587 they are non-zero it means that some operands have already been found.
2588 No variables may be used anywhere else in the expression except in the
2589 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2590 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2592 If this is true, return 1. Otherwise, return zero. */
2595 twoval_comparison_p (arg
, cval1
, cval2
, save_p
)
2597 tree
*cval1
, *cval2
;
2600 enum tree_code code
= TREE_CODE (arg
);
2601 char class = TREE_CODE_CLASS (code
);
2603 /* We can handle some of the 'e' cases here. */
2604 if (class == 'e' && code
== TRUTH_NOT_EXPR
)
2606 else if (class == 'e'
2607 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
2608 || code
== COMPOUND_EXPR
))
2611 else if (class == 'e' && code
== SAVE_EXPR
&& SAVE_EXPR_RTL (arg
) == 0
2612 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg
, 0)))
2614 /* If we've already found a CVAL1 or CVAL2, this expression is
2615 two complex to handle. */
2616 if (*cval1
|| *cval2
)
2626 return twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
);
2629 return (twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
)
2630 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2631 cval1
, cval2
, save_p
));
2637 if (code
== COND_EXPR
)
2638 return (twoval_comparison_p (TREE_OPERAND (arg
, 0),
2639 cval1
, cval2
, save_p
)
2640 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2641 cval1
, cval2
, save_p
)
2642 && twoval_comparison_p (TREE_OPERAND (arg
, 2),
2643 cval1
, cval2
, save_p
));
2647 /* First see if we can handle the first operand, then the second. For
2648 the second operand, we know *CVAL1 can't be zero. It must be that
2649 one side of the comparison is each of the values; test for the
2650 case where this isn't true by failing if the two operands
2653 if (operand_equal_p (TREE_OPERAND (arg
, 0),
2654 TREE_OPERAND (arg
, 1), 0))
2658 *cval1
= TREE_OPERAND (arg
, 0);
2659 else if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 0), 0))
2661 else if (*cval2
== 0)
2662 *cval2
= TREE_OPERAND (arg
, 0);
2663 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 0), 0))
2668 if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 1), 0))
2670 else if (*cval2
== 0)
2671 *cval2
= TREE_OPERAND (arg
, 1);
2672 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 1), 0))
2684 /* ARG is a tree that is known to contain just arithmetic operations and
2685 comparisons. Evaluate the operations in the tree substituting NEW0 for
2686 any occurrence of OLD0 as an operand of a comparison and likewise for
2690 eval_subst (arg
, old0
, new0
, old1
, new1
)
2692 tree old0
, new0
, old1
, new1
;
2694 tree type
= TREE_TYPE (arg
);
2695 enum tree_code code
= TREE_CODE (arg
);
2696 char class = TREE_CODE_CLASS (code
);
2698 /* We can handle some of the 'e' cases here. */
2699 if (class == 'e' && code
== TRUTH_NOT_EXPR
)
2701 else if (class == 'e'
2702 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
))
2708 return fold (build1 (code
, type
,
2709 eval_subst (TREE_OPERAND (arg
, 0),
2710 old0
, new0
, old1
, new1
)));
2713 return fold (build (code
, type
,
2714 eval_subst (TREE_OPERAND (arg
, 0),
2715 old0
, new0
, old1
, new1
),
2716 eval_subst (TREE_OPERAND (arg
, 1),
2717 old0
, new0
, old1
, new1
)));
2723 return eval_subst (TREE_OPERAND (arg
, 0), old0
, new0
, old1
, new1
);
2726 return eval_subst (TREE_OPERAND (arg
, 1), old0
, new0
, old1
, new1
);
2729 return fold (build (code
, type
,
2730 eval_subst (TREE_OPERAND (arg
, 0),
2731 old0
, new0
, old1
, new1
),
2732 eval_subst (TREE_OPERAND (arg
, 1),
2733 old0
, new0
, old1
, new1
),
2734 eval_subst (TREE_OPERAND (arg
, 2),
2735 old0
, new0
, old1
, new1
)));
2739 /* fall through - ??? */
2743 tree arg0
= TREE_OPERAND (arg
, 0);
2744 tree arg1
= TREE_OPERAND (arg
, 1);
2746 /* We need to check both for exact equality and tree equality. The
2747 former will be true if the operand has a side-effect. In that
2748 case, we know the operand occurred exactly once. */
2750 if (arg0
== old0
|| operand_equal_p (arg0
, old0
, 0))
2752 else if (arg0
== old1
|| operand_equal_p (arg0
, old1
, 0))
2755 if (arg1
== old0
|| operand_equal_p (arg1
, old0
, 0))
2757 else if (arg1
== old1
|| operand_equal_p (arg1
, old1
, 0))
2760 return fold (build (code
, type
, arg0
, arg1
));
2768 /* Return a tree for the case when the result of an expression is RESULT
2769 converted to TYPE and OMITTED was previously an operand of the expression
2770 but is now not needed (e.g., we folded OMITTED * 0).
2772 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2773 the conversion of RESULT to TYPE. */
2776 omit_one_operand (type
, result
, omitted
)
2777 tree type
, result
, omitted
;
2779 tree t
= convert (type
, result
);
2781 if (TREE_SIDE_EFFECTS (omitted
))
2782 return build (COMPOUND_EXPR
, type
, omitted
, t
);
2784 return non_lvalue (t
);
2787 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2790 pedantic_omit_one_operand (type
, result
, omitted
)
2791 tree type
, result
, omitted
;
2793 tree t
= convert (type
, result
);
2795 if (TREE_SIDE_EFFECTS (omitted
))
2796 return build (COMPOUND_EXPR
, type
, omitted
, t
);
2798 return pedantic_non_lvalue (t
);
2801 /* Return a simplified tree node for the truth-negation of ARG. This
2802 never alters ARG itself. We assume that ARG is an operation that
2803 returns a truth value (0 or 1). */
2806 invert_truthvalue (arg
)
2809 tree type
= TREE_TYPE (arg
);
2810 enum tree_code code
= TREE_CODE (arg
);
2812 if (code
== ERROR_MARK
)
2815 /* If this is a comparison, we can simply invert it, except for
2816 floating-point non-equality comparisons, in which case we just
2817 enclose a TRUTH_NOT_EXPR around what we have. */
2819 if (TREE_CODE_CLASS (code
) == '<')
2821 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg
, 0)))
2822 && !flag_unsafe_math_optimizations
2825 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2827 return build (invert_tree_comparison (code
), type
,
2828 TREE_OPERAND (arg
, 0), TREE_OPERAND (arg
, 1));
2834 return convert (type
, build_int_2 (integer_zerop (arg
), 0));
2836 case TRUTH_AND_EXPR
:
2837 return build (TRUTH_OR_EXPR
, type
,
2838 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2839 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2842 return build (TRUTH_AND_EXPR
, type
,
2843 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2844 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2846 case TRUTH_XOR_EXPR
:
2847 /* Here we can invert either operand. We invert the first operand
2848 unless the second operand is a TRUTH_NOT_EXPR in which case our
2849 result is the XOR of the first operand with the inside of the
2850 negation of the second operand. */
2852 if (TREE_CODE (TREE_OPERAND (arg
, 1)) == TRUTH_NOT_EXPR
)
2853 return build (TRUTH_XOR_EXPR
, type
, TREE_OPERAND (arg
, 0),
2854 TREE_OPERAND (TREE_OPERAND (arg
, 1), 0));
2856 return build (TRUTH_XOR_EXPR
, type
,
2857 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2858 TREE_OPERAND (arg
, 1));
2860 case TRUTH_ANDIF_EXPR
:
2861 return build (TRUTH_ORIF_EXPR
, type
,
2862 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2863 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2865 case TRUTH_ORIF_EXPR
:
2866 return build (TRUTH_ANDIF_EXPR
, type
,
2867 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2868 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2870 case TRUTH_NOT_EXPR
:
2871 return TREE_OPERAND (arg
, 0);
2874 return build (COND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2875 invert_truthvalue (TREE_OPERAND (arg
, 1)),
2876 invert_truthvalue (TREE_OPERAND (arg
, 2)));
2879 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2880 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2882 case WITH_RECORD_EXPR
:
2883 return build (WITH_RECORD_EXPR
, type
,
2884 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2885 TREE_OPERAND (arg
, 1));
2887 case NON_LVALUE_EXPR
:
2888 return invert_truthvalue (TREE_OPERAND (arg
, 0));
2893 return build1 (TREE_CODE (arg
), type
,
2894 invert_truthvalue (TREE_OPERAND (arg
, 0)));
2897 if (!integer_onep (TREE_OPERAND (arg
, 1)))
2899 return build (EQ_EXPR
, type
, arg
, convert (type
, integer_zero_node
));
2902 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2904 case CLEANUP_POINT_EXPR
:
2905 return build1 (CLEANUP_POINT_EXPR
, type
,
2906 invert_truthvalue (TREE_OPERAND (arg
, 0)));
2911 if (TREE_CODE (TREE_TYPE (arg
)) != BOOLEAN_TYPE
)
2913 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2916 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2917 operands are another bit-wise operation with a common input. If so,
2918 distribute the bit operations to save an operation and possibly two if
2919 constants are involved. For example, convert
2920 (A | B) & (A | C) into A | (B & C)
2921 Further simplification will occur if B and C are constants.
2923 If this optimization cannot be done, 0 will be returned. */
2926 distribute_bit_expr (code
, type
, arg0
, arg1
)
2927 enum tree_code code
;
2934 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
2935 || TREE_CODE (arg0
) == code
2936 || (TREE_CODE (arg0
) != BIT_AND_EXPR
2937 && TREE_CODE (arg0
) != BIT_IOR_EXPR
))
2940 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0))
2942 common
= TREE_OPERAND (arg0
, 0);
2943 left
= TREE_OPERAND (arg0
, 1);
2944 right
= TREE_OPERAND (arg1
, 1);
2946 else if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 1), 0))
2948 common
= TREE_OPERAND (arg0
, 0);
2949 left
= TREE_OPERAND (arg0
, 1);
2950 right
= TREE_OPERAND (arg1
, 0);
2952 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 0), 0))
2954 common
= TREE_OPERAND (arg0
, 1);
2955 left
= TREE_OPERAND (arg0
, 0);
2956 right
= TREE_OPERAND (arg1
, 1);
2958 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1), 0))
2960 common
= TREE_OPERAND (arg0
, 1);
2961 left
= TREE_OPERAND (arg0
, 0);
2962 right
= TREE_OPERAND (arg1
, 0);
2967 return fold (build (TREE_CODE (arg0
), type
, common
,
2968 fold (build (code
, type
, left
, right
))));
2971 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2972 starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */
2975 make_bit_field_ref (inner
, type
, bitsize
, bitpos
, unsignedp
)
2978 int bitsize
, bitpos
;
2981 tree result
= build (BIT_FIELD_REF
, type
, inner
,
2982 size_int (bitsize
), bitsize_int (bitpos
));
2984 TREE_UNSIGNED (result
) = unsignedp
;
2989 /* Optimize a bit-field compare.
2991 There are two cases: First is a compare against a constant and the
2992 second is a comparison of two items where the fields are at the same
2993 bit position relative to the start of a chunk (byte, halfword, word)
2994 large enough to contain it. In these cases we can avoid the shift
2995 implicit in bitfield extractions.
2997 For constants, we emit a compare of the shifted constant with the
2998 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2999 compared. For two fields at the same position, we do the ANDs with the
3000 similar mask and compare the result of the ANDs.
3002 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3003 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3004 are the left and right operands of the comparison, respectively.
3006 If the optimization described above can be done, we return the resulting
3007 tree. Otherwise we return zero. */
3010 optimize_bit_field_compare (code
, compare_type
, lhs
, rhs
)
3011 enum tree_code code
;
3015 HOST_WIDE_INT lbitpos
, lbitsize
, rbitpos
, rbitsize
, nbitpos
, nbitsize
;
3016 tree type
= TREE_TYPE (lhs
);
3017 tree signed_type
, unsigned_type
;
3018 int const_p
= TREE_CODE (rhs
) == INTEGER_CST
;
3019 enum machine_mode lmode
, rmode
, nmode
;
3020 int lunsignedp
, runsignedp
;
3021 int lvolatilep
= 0, rvolatilep
= 0;
3022 tree linner
, rinner
= NULL_TREE
;
3026 /* Get all the information about the extractions being done. If the bit size
3027 if the same as the size of the underlying object, we aren't doing an
3028 extraction at all and so can do nothing. We also don't want to
3029 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3030 then will no longer be able to replace it. */
3031 linner
= get_inner_reference (lhs
, &lbitsize
, &lbitpos
, &offset
, &lmode
,
3032 &lunsignedp
, &lvolatilep
);
3033 if (linner
== lhs
|| lbitsize
== GET_MODE_BITSIZE (lmode
) || lbitsize
< 0
3034 || offset
!= 0 || TREE_CODE (linner
) == PLACEHOLDER_EXPR
)
3039 /* If this is not a constant, we can only do something if bit positions,
3040 sizes, and signedness are the same. */
3041 rinner
= get_inner_reference (rhs
, &rbitsize
, &rbitpos
, &offset
, &rmode
,
3042 &runsignedp
, &rvolatilep
);
3044 if (rinner
== rhs
|| lbitpos
!= rbitpos
|| lbitsize
!= rbitsize
3045 || lunsignedp
!= runsignedp
|| offset
!= 0
3046 || TREE_CODE (rinner
) == PLACEHOLDER_EXPR
)
3050 /* See if we can find a mode to refer to this field. We should be able to,
3051 but fail if we can't. */
3052 nmode
= get_best_mode (lbitsize
, lbitpos
,
3053 const_p
? TYPE_ALIGN (TREE_TYPE (linner
))
3054 : MIN (TYPE_ALIGN (TREE_TYPE (linner
)),
3055 TYPE_ALIGN (TREE_TYPE (rinner
))),
3056 word_mode
, lvolatilep
|| rvolatilep
);
3057 if (nmode
== VOIDmode
)
3060 /* Set signed and unsigned types of the precision of this mode for the
3062 signed_type
= type_for_mode (nmode
, 0);
3063 unsigned_type
= type_for_mode (nmode
, 1);
3065 /* Compute the bit position and size for the new reference and our offset
3066 within it. If the new reference is the same size as the original, we
3067 won't optimize anything, so return zero. */
3068 nbitsize
= GET_MODE_BITSIZE (nmode
);
3069 nbitpos
= lbitpos
& ~ (nbitsize
- 1);
3071 if (nbitsize
== lbitsize
)
3074 if (BYTES_BIG_ENDIAN
)
3075 lbitpos
= nbitsize
- lbitsize
- lbitpos
;
3077 /* Make the mask to be used against the extracted field. */
3078 mask
= build_int_2 (~0, ~0);
3079 TREE_TYPE (mask
) = unsigned_type
;
3080 force_fit_type (mask
, 0);
3081 mask
= convert (unsigned_type
, mask
);
3082 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (nbitsize
- lbitsize
), 0);
3083 mask
= const_binop (RSHIFT_EXPR
, mask
,
3084 size_int (nbitsize
- lbitsize
- lbitpos
), 0);
3087 /* If not comparing with constant, just rework the comparison
3089 return build (code
, compare_type
,
3090 build (BIT_AND_EXPR
, unsigned_type
,
3091 make_bit_field_ref (linner
, unsigned_type
,
3092 nbitsize
, nbitpos
, 1),
3094 build (BIT_AND_EXPR
, unsigned_type
,
3095 make_bit_field_ref (rinner
, unsigned_type
,
3096 nbitsize
, nbitpos
, 1),
3099 /* Otherwise, we are handling the constant case. See if the constant is too
3100 big for the field. Warn and return a tree of for 0 (false) if so. We do
3101 this not only for its own sake, but to avoid having to test for this
3102 error case below. If we didn't, we might generate wrong code.
3104 For unsigned fields, the constant shifted right by the field length should
3105 be all zero. For signed fields, the high-order bits should agree with
3110 if (! integer_zerop (const_binop (RSHIFT_EXPR
,
3111 convert (unsigned_type
, rhs
),
3112 size_int (lbitsize
), 0)))
3114 warning ("comparison is always %d due to width of bit-field",
3116 return convert (compare_type
,
3118 ? integer_one_node
: integer_zero_node
));
3123 tree tem
= const_binop (RSHIFT_EXPR
, convert (signed_type
, rhs
),
3124 size_int (lbitsize
- 1), 0);
3125 if (! integer_zerop (tem
) && ! integer_all_onesp (tem
))
3127 warning ("comparison is always %d due to width of bit-field",
3129 return convert (compare_type
,
3131 ? integer_one_node
: integer_zero_node
));
3135 /* Single-bit compares should always be against zero. */
3136 if (lbitsize
== 1 && ! integer_zerop (rhs
))
3138 code
= code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
;
3139 rhs
= convert (type
, integer_zero_node
);
3142 /* Make a new bitfield reference, shift the constant over the
3143 appropriate number of bits and mask it with the computed mask
3144 (in case this was a signed field). If we changed it, make a new one. */
3145 lhs
= make_bit_field_ref (linner
, unsigned_type
, nbitsize
, nbitpos
, 1);
3148 TREE_SIDE_EFFECTS (lhs
) = 1;
3149 TREE_THIS_VOLATILE (lhs
) = 1;
3152 rhs
= fold (const_binop (BIT_AND_EXPR
,
3153 const_binop (LSHIFT_EXPR
,
3154 convert (unsigned_type
, rhs
),
3155 size_int (lbitpos
), 0),
3158 return build (code
, compare_type
,
3159 build (BIT_AND_EXPR
, unsigned_type
, lhs
, mask
),
3163 /* Subroutine for fold_truthop: decode a field reference.
3165 If EXP is a comparison reference, we return the innermost reference.
3167 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3168 set to the starting bit number.
3170 If the innermost field can be completely contained in a mode-sized
3171 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3173 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3174 otherwise it is not changed.
3176 *PUNSIGNEDP is set to the signedness of the field.
3178 *PMASK is set to the mask used. This is either contained in a
3179 BIT_AND_EXPR or derived from the width of the field.
3181 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3183 Return 0 if this is not a component reference or is one that we can't
3184 do anything with. */
3187 decode_field_reference (exp
, pbitsize
, pbitpos
, pmode
, punsignedp
,
3188 pvolatilep
, pmask
, pand_mask
)
3190 HOST_WIDE_INT
*pbitsize
, *pbitpos
;
3191 enum machine_mode
*pmode
;
3192 int *punsignedp
, *pvolatilep
;
3197 tree mask
, inner
, offset
;
3199 unsigned int precision
;
3201 /* All the optimizations using this function assume integer fields.
3202 There are problems with FP fields since the type_for_size call
3203 below can fail for, e.g., XFmode. */
3204 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp
)))
3209 if (TREE_CODE (exp
) == BIT_AND_EXPR
)
3211 and_mask
= TREE_OPERAND (exp
, 1);
3212 exp
= TREE_OPERAND (exp
, 0);
3213 STRIP_NOPS (exp
); STRIP_NOPS (and_mask
);
3214 if (TREE_CODE (and_mask
) != INTEGER_CST
)
3218 inner
= get_inner_reference (exp
, pbitsize
, pbitpos
, &offset
, pmode
,
3219 punsignedp
, pvolatilep
);
3220 if ((inner
== exp
&& and_mask
== 0)
3221 || *pbitsize
< 0 || offset
!= 0
3222 || TREE_CODE (inner
) == PLACEHOLDER_EXPR
)
3225 /* Compute the mask to access the bitfield. */
3226 unsigned_type
= type_for_size (*pbitsize
, 1);
3227 precision
= TYPE_PRECISION (unsigned_type
);
3229 mask
= build_int_2 (~0, ~0);
3230 TREE_TYPE (mask
) = unsigned_type
;
3231 force_fit_type (mask
, 0);
3232 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
3233 mask
= const_binop (RSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
3235 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3237 mask
= fold (build (BIT_AND_EXPR
, unsigned_type
,
3238 convert (unsigned_type
, and_mask
), mask
));
3241 *pand_mask
= and_mask
;
3245 /* Return non-zero if MASK represents a mask of SIZE ones in the low-order
3249 all_ones_mask_p (mask
, size
)
3253 tree type
= TREE_TYPE (mask
);
3254 unsigned int precision
= TYPE_PRECISION (type
);
3257 tmask
= build_int_2 (~0, ~0);
3258 TREE_TYPE (tmask
) = signed_type (type
);
3259 force_fit_type (tmask
, 0);
3261 tree_int_cst_equal (mask
,
3262 const_binop (RSHIFT_EXPR
,
3263 const_binop (LSHIFT_EXPR
, tmask
,
3264 size_int (precision
- size
),
3266 size_int (precision
- size
), 0));
3269 /* Subroutine for fold_truthop: determine if an operand is simple enough
3270 to be evaluated unconditionally. */
3273 simple_operand_p (exp
)
3276 /* Strip any conversions that don't change the machine mode. */
3277 while ((TREE_CODE (exp
) == NOP_EXPR
3278 || TREE_CODE (exp
) == CONVERT_EXPR
)
3279 && (TYPE_MODE (TREE_TYPE (exp
))
3280 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp
, 0)))))
3281 exp
= TREE_OPERAND (exp
, 0);
3283 return (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'c'
3285 && ! TREE_ADDRESSABLE (exp
)
3286 && ! TREE_THIS_VOLATILE (exp
)
3287 && ! DECL_NONLOCAL (exp
)
3288 /* Don't regard global variables as simple. They may be
3289 allocated in ways unknown to the compiler (shared memory,
3290 #pragma weak, etc). */
3291 && ! TREE_PUBLIC (exp
)
3292 && ! DECL_EXTERNAL (exp
)
3293 /* Loading a static variable is unduly expensive, but global
3294 registers aren't expensive. */
3295 && (! TREE_STATIC (exp
) || DECL_REGISTER (exp
))));
3298 /* The following functions are subroutines to fold_range_test and allow it to
3299 try to change a logical combination of comparisons into a range test.
3302 X == 2 || X == 3 || X == 4 || X == 5
3306 (unsigned) (X - 2) <= 3
3308 We describe each set of comparisons as being either inside or outside
3309 a range, using a variable named like IN_P, and then describe the
3310 range with a lower and upper bound. If one of the bounds is omitted,
3311 it represents either the highest or lowest value of the type.
3313 In the comments below, we represent a range by two numbers in brackets
3314 preceded by a "+" to designate being inside that range, or a "-" to
3315 designate being outside that range, so the condition can be inverted by
3316 flipping the prefix. An omitted bound is represented by a "-". For
3317 example, "- [-, 10]" means being outside the range starting at the lowest
3318 possible value and ending at 10, in other words, being greater than 10.
3319 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3322 We set up things so that the missing bounds are handled in a consistent
3323 manner so neither a missing bound nor "true" and "false" need to be
3324 handled using a special case. */
3326 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3327 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3328 and UPPER1_P are nonzero if the respective argument is an upper bound
3329 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3330 must be specified for a comparison. ARG1 will be converted to ARG0's
3331 type if both are specified. */
3334 range_binop (code
, type
, arg0
, upper0_p
, arg1
, upper1_p
)
3335 enum tree_code code
;
3338 int upper0_p
, upper1_p
;
3344 /* If neither arg represents infinity, do the normal operation.
3345 Else, if not a comparison, return infinity. Else handle the special
3346 comparison rules. Note that most of the cases below won't occur, but
3347 are handled for consistency. */
3349 if (arg0
!= 0 && arg1
!= 0)
3351 tem
= fold (build (code
, type
!= 0 ? type
: TREE_TYPE (arg0
),
3352 arg0
, convert (TREE_TYPE (arg0
), arg1
)));
3354 return TREE_CODE (tem
) == INTEGER_CST
? tem
: 0;
3357 if (TREE_CODE_CLASS (code
) != '<')
3360 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3361 for neither. In real maths, we cannot assume open ended ranges are
3362 the same. But, this is computer arithmetic, where numbers are finite.
3363 We can therefore make the transformation of any unbounded range with
3364 the value Z, Z being greater than any representable number. This permits
3365 us to treat unbounded ranges as equal. */
3366 sgn0
= arg0
!= 0 ? 0 : (upper0_p
? 1 : -1);
3367 sgn1
= arg1
!= 0 ? 0 : (upper1_p
? 1 : -1);
3371 result
= sgn0
== sgn1
;
3374 result
= sgn0
!= sgn1
;
3377 result
= sgn0
< sgn1
;
3380 result
= sgn0
<= sgn1
;
3383 result
= sgn0
> sgn1
;
3386 result
= sgn0
>= sgn1
;
3392 return convert (type
, result
? integer_one_node
: integer_zero_node
);
3395 /* Given EXP, a logical expression, set the range it is testing into
3396 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3397 actually being tested. *PLOW and *PHIGH will be made of the same type
3398 as the returned expression. If EXP is not a comparison, we will most
3399 likely not be returning a useful value and range. */
3402 make_range (exp
, pin_p
, plow
, phigh
)
3407 enum tree_code code
;
3408 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
, type
= NULL_TREE
;
3409 tree orig_type
= NULL_TREE
;
3411 tree low
, high
, n_low
, n_high
;
3413 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3414 and see if we can refine the range. Some of the cases below may not
3415 happen, but it doesn't seem worth worrying about this. We "continue"
3416 the outer loop when we've changed something; otherwise we "break"
3417 the switch, which will "break" the while. */
3419 in_p
= 0, low
= high
= convert (TREE_TYPE (exp
), integer_zero_node
);
3423 code
= TREE_CODE (exp
);
3425 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code
)))
3427 arg0
= TREE_OPERAND (exp
, 0);
3428 if (TREE_CODE_CLASS (code
) == '<'
3429 || TREE_CODE_CLASS (code
) == '1'
3430 || TREE_CODE_CLASS (code
) == '2')
3431 type
= TREE_TYPE (arg0
);
3432 if (TREE_CODE_CLASS (code
) == '2'
3433 || TREE_CODE_CLASS (code
) == '<'
3434 || (TREE_CODE_CLASS (code
) == 'e'
3435 && TREE_CODE_LENGTH (code
) > 1))
3436 arg1
= TREE_OPERAND (exp
, 1);
3439 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3440 lose a cast by accident. */
3441 if (type
!= NULL_TREE
&& orig_type
== NULL_TREE
)
3446 case TRUTH_NOT_EXPR
:
3447 in_p
= ! in_p
, exp
= arg0
;
3450 case EQ_EXPR
: case NE_EXPR
:
3451 case LT_EXPR
: case LE_EXPR
: case GE_EXPR
: case GT_EXPR
:
3452 /* We can only do something if the range is testing for zero
3453 and if the second operand is an integer constant. Note that
3454 saying something is "in" the range we make is done by
3455 complementing IN_P since it will set in the initial case of
3456 being not equal to zero; "out" is leaving it alone. */
3457 if (low
== 0 || high
== 0
3458 || ! integer_zerop (low
) || ! integer_zerop (high
)
3459 || TREE_CODE (arg1
) != INTEGER_CST
)
3464 case NE_EXPR
: /* - [c, c] */
3467 case EQ_EXPR
: /* + [c, c] */
3468 in_p
= ! in_p
, low
= high
= arg1
;
3470 case GT_EXPR
: /* - [-, c] */
3471 low
= 0, high
= arg1
;
3473 case GE_EXPR
: /* + [c, -] */
3474 in_p
= ! in_p
, low
= arg1
, high
= 0;
3476 case LT_EXPR
: /* - [c, -] */
3477 low
= arg1
, high
= 0;
3479 case LE_EXPR
: /* + [-, c] */
3480 in_p
= ! in_p
, low
= 0, high
= arg1
;
3488 /* If this is an unsigned comparison, we also know that EXP is
3489 greater than or equal to zero. We base the range tests we make
3490 on that fact, so we record it here so we can parse existing
3492 if (TREE_UNSIGNED (type
) && (low
== 0 || high
== 0))
3494 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
, in_p
, low
, high
,
3495 1, convert (type
, integer_zero_node
),
3499 in_p
= n_in_p
, low
= n_low
, high
= n_high
;
3501 /* If the high bound is missing, but we
3502 have a low bound, reverse the range so
3503 it goes from zero to the low bound minus 1. */
3504 if (high
== 0 && low
)
3507 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low
, 0,
3508 integer_one_node
, 0);
3509 low
= convert (type
, integer_zero_node
);
3515 /* (-x) IN [a,b] -> x in [-b, -a] */
3516 n_low
= range_binop (MINUS_EXPR
, type
,
3517 convert (type
, integer_zero_node
), 0, high
, 1);
3518 n_high
= range_binop (MINUS_EXPR
, type
,
3519 convert (type
, integer_zero_node
), 0, low
, 0);
3520 low
= n_low
, high
= n_high
;
3526 exp
= build (MINUS_EXPR
, type
, negate_expr (arg0
),
3527 convert (type
, integer_one_node
));
3530 case PLUS_EXPR
: case MINUS_EXPR
:
3531 if (TREE_CODE (arg1
) != INTEGER_CST
)
3534 /* If EXP is signed, any overflow in the computation is undefined,
3535 so we don't worry about it so long as our computations on
3536 the bounds don't overflow. For unsigned, overflow is defined
3537 and this is exactly the right thing. */
3538 n_low
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3539 type
, low
, 0, arg1
, 0);
3540 n_high
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3541 type
, high
, 1, arg1
, 0);
3542 if ((n_low
!= 0 && TREE_OVERFLOW (n_low
))
3543 || (n_high
!= 0 && TREE_OVERFLOW (n_high
)))
3546 /* Check for an unsigned range which has wrapped around the maximum
3547 value thus making n_high < n_low, and normalize it. */
3548 if (n_low
&& n_high
&& tree_int_cst_lt (n_high
, n_low
))
3550 low
= range_binop (PLUS_EXPR
, type
, n_high
, 0,
3551 integer_one_node
, 0);
3552 high
= range_binop (MINUS_EXPR
, type
, n_low
, 0,
3553 integer_one_node
, 0);
3555 /* If the range is of the form +/- [ x+1, x ], we won't
3556 be able to normalize it. But then, it represents the
3557 whole range or the empty set, so make it
3559 if (tree_int_cst_equal (n_low
, low
)
3560 && tree_int_cst_equal (n_high
, high
))
3566 low
= n_low
, high
= n_high
;
3571 case NOP_EXPR
: case NON_LVALUE_EXPR
: case CONVERT_EXPR
:
3572 if (TYPE_PRECISION (type
) > TYPE_PRECISION (orig_type
))
3575 if (! INTEGRAL_TYPE_P (type
)
3576 || (low
!= 0 && ! int_fits_type_p (low
, type
))
3577 || (high
!= 0 && ! int_fits_type_p (high
, type
)))
3580 n_low
= low
, n_high
= high
;
3583 n_low
= convert (type
, n_low
);
3586 n_high
= convert (type
, n_high
);
3588 /* If we're converting from an unsigned to a signed type,
3589 we will be doing the comparison as unsigned. The tests above
3590 have already verified that LOW and HIGH are both positive.
3592 So we have to make sure that the original unsigned value will
3593 be interpreted as positive. */
3594 if (TREE_UNSIGNED (type
) && ! TREE_UNSIGNED (TREE_TYPE (exp
)))
3596 tree equiv_type
= type_for_mode (TYPE_MODE (type
), 1);
3599 /* A range without an upper bound is, naturally, unbounded.
3600 Since convert would have cropped a very large value, use
3601 the max value for the destination type. */
3603 = TYPE_MAX_VALUE (equiv_type
) ? TYPE_MAX_VALUE (equiv_type
)
3604 : TYPE_MAX_VALUE (type
);
3606 high_positive
= fold (build (RSHIFT_EXPR
, type
,
3607 convert (type
, high_positive
),
3608 convert (type
, integer_one_node
)));
3610 /* If the low bound is specified, "and" the range with the
3611 range for which the original unsigned value will be
3615 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3617 1, convert (type
, integer_zero_node
),
3621 in_p
= (n_in_p
== in_p
);
3625 /* Otherwise, "or" the range with the range of the input
3626 that will be interpreted as negative. */
3627 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3629 1, convert (type
, integer_zero_node
),
3633 in_p
= (in_p
!= n_in_p
);
3638 low
= n_low
, high
= n_high
;
3648 /* If EXP is a constant, we can evaluate whether this is true or false. */
3649 if (TREE_CODE (exp
) == INTEGER_CST
)
3651 in_p
= in_p
== (integer_onep (range_binop (GE_EXPR
, integer_type_node
,
3653 && integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3659 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
3663 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3664 type, TYPE, return an expression to test if EXP is in (or out of, depending
3665 on IN_P) the range. */
3668 build_range_check (type
, exp
, in_p
, low
, high
)
3674 tree etype
= TREE_TYPE (exp
);
3678 && (0 != (value
= build_range_check (type
, exp
, 1, low
, high
))))
3679 return invert_truthvalue (value
);
3681 else if (low
== 0 && high
== 0)
3682 return convert (type
, integer_one_node
);
3685 return fold (build (LE_EXPR
, type
, exp
, high
));
3688 return fold (build (GE_EXPR
, type
, exp
, low
));
3690 else if (operand_equal_p (low
, high
, 0))
3691 return fold (build (EQ_EXPR
, type
, exp
, low
));
3693 else if (TREE_UNSIGNED (etype
) && integer_zerop (low
))
3694 return build_range_check (type
, exp
, 1, 0, high
);
3696 else if (integer_zerop (low
))
3698 utype
= unsigned_type (etype
);
3699 return build_range_check (type
, convert (utype
, exp
), 1, 0,
3700 convert (utype
, high
));
3703 else if (0 != (value
= const_binop (MINUS_EXPR
, high
, low
, 0))
3704 && ! TREE_OVERFLOW (value
))
3705 return build_range_check (type
,
3706 fold (build (MINUS_EXPR
, etype
, exp
, low
)),
3707 1, convert (etype
, integer_zero_node
), value
);
3712 /* Given two ranges, see if we can merge them into one. Return 1 if we
3713 can, 0 if we can't. Set the output range into the specified parameters. */
3716 merge_ranges (pin_p
, plow
, phigh
, in0_p
, low0
, high0
, in1_p
, low1
, high1
)
3720 tree low0
, high0
, low1
, high1
;
3728 int lowequal
= ((low0
== 0 && low1
== 0)
3729 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3730 low0
, 0, low1
, 0)));
3731 int highequal
= ((high0
== 0 && high1
== 0)
3732 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3733 high0
, 1, high1
, 1)));
3735 /* Make range 0 be the range that starts first, or ends last if they
3736 start at the same value. Swap them if it isn't. */
3737 if (integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3740 && integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3741 high1
, 1, high0
, 1))))
3743 temp
= in0_p
, in0_p
= in1_p
, in1_p
= temp
;
3744 tem
= low0
, low0
= low1
, low1
= tem
;
3745 tem
= high0
, high0
= high1
, high1
= tem
;
3748 /* Now flag two cases, whether the ranges are disjoint or whether the
3749 second range is totally subsumed in the first. Note that the tests
3750 below are simplified by the ones above. */
3751 no_overlap
= integer_onep (range_binop (LT_EXPR
, integer_type_node
,
3752 high0
, 1, low1
, 0));
3753 subset
= integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3754 high1
, 1, high0
, 1));
3756 /* We now have four cases, depending on whether we are including or
3757 excluding the two ranges. */
3760 /* If they don't overlap, the result is false. If the second range
3761 is a subset it is the result. Otherwise, the range is from the start
3762 of the second to the end of the first. */
3764 in_p
= 0, low
= high
= 0;
3766 in_p
= 1, low
= low1
, high
= high1
;
3768 in_p
= 1, low
= low1
, high
= high0
;
3771 else if (in0_p
&& ! in1_p
)
3773 /* If they don't overlap, the result is the first range. If they are
3774 equal, the result is false. If the second range is a subset of the
3775 first, and the ranges begin at the same place, we go from just after
3776 the end of the first range to the end of the second. If the second
3777 range is not a subset of the first, or if it is a subset and both
3778 ranges end at the same place, the range starts at the start of the
3779 first range and ends just before the second range.
3780 Otherwise, we can't describe this as a single range. */
3782 in_p
= 1, low
= low0
, high
= high0
;
3783 else if (lowequal
&& highequal
)
3784 in_p
= 0, low
= high
= 0;
3785 else if (subset
&& lowequal
)
3787 in_p
= 1, high
= high0
;
3788 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high1
, 0,
3789 integer_one_node
, 0);
3791 else if (! subset
|| highequal
)
3793 in_p
= 1, low
= low0
;
3794 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low1
, 0,
3795 integer_one_node
, 0);
3801 else if (! in0_p
&& in1_p
)
3803 /* If they don't overlap, the result is the second range. If the second
3804 is a subset of the first, the result is false. Otherwise,
3805 the range starts just after the first range and ends at the
3806 end of the second. */
3808 in_p
= 1, low
= low1
, high
= high1
;
3809 else if (subset
|| highequal
)
3810 in_p
= 0, low
= high
= 0;
3813 in_p
= 1, high
= high1
;
3814 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high0
, 1,
3815 integer_one_node
, 0);
3821 /* The case where we are excluding both ranges. Here the complex case
3822 is if they don't overlap. In that case, the only time we have a
3823 range is if they are adjacent. If the second is a subset of the
3824 first, the result is the first. Otherwise, the range to exclude
3825 starts at the beginning of the first range and ends at the end of the
3829 if (integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3830 range_binop (PLUS_EXPR
, NULL_TREE
,
3832 integer_one_node
, 1),
3834 in_p
= 0, low
= low0
, high
= high1
;
3839 in_p
= 0, low
= low0
, high
= high0
;
3841 in_p
= 0, low
= low0
, high
= high1
;
3844 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
3848 /* EXP is some logical combination of boolean tests. See if we can
3849 merge it into some range test. Return the new tree if so. */
3852 fold_range_test (exp
)
3855 int or_op
= (TREE_CODE (exp
) == TRUTH_ORIF_EXPR
3856 || TREE_CODE (exp
) == TRUTH_OR_EXPR
);
3857 int in0_p
, in1_p
, in_p
;
3858 tree low0
, low1
, low
, high0
, high1
, high
;
3859 tree lhs
= make_range (TREE_OPERAND (exp
, 0), &in0_p
, &low0
, &high0
);
3860 tree rhs
= make_range (TREE_OPERAND (exp
, 1), &in1_p
, &low1
, &high1
);
3863 /* If this is an OR operation, invert both sides; we will invert
3864 again at the end. */
3866 in0_p
= ! in0_p
, in1_p
= ! in1_p
;
3868 /* If both expressions are the same, if we can merge the ranges, and we
3869 can build the range test, return it or it inverted. If one of the
3870 ranges is always true or always false, consider it to be the same
3871 expression as the other. */
3872 if ((lhs
== 0 || rhs
== 0 || operand_equal_p (lhs
, rhs
, 0))
3873 && merge_ranges (&in_p
, &low
, &high
, in0_p
, low0
, high0
,
3875 && 0 != (tem
= (build_range_check (TREE_TYPE (exp
),
3877 : rhs
!= 0 ? rhs
: integer_zero_node
,
3879 return or_op
? invert_truthvalue (tem
) : tem
;
3881 /* On machines where the branch cost is expensive, if this is a
3882 short-circuited branch and the underlying object on both sides
3883 is the same, make a non-short-circuit operation. */
3884 else if (BRANCH_COST
>= 2
3885 && lhs
!= 0 && rhs
!= 0
3886 && (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3887 || TREE_CODE (exp
) == TRUTH_ORIF_EXPR
)
3888 && operand_equal_p (lhs
, rhs
, 0))
3890 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3891 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3892 which cases we can't do this. */
3893 if (simple_operand_p (lhs
))
3894 return build (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3895 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
3896 TREE_TYPE (exp
), TREE_OPERAND (exp
, 0),
3897 TREE_OPERAND (exp
, 1));
3899 else if (global_bindings_p () == 0
3900 && ! contains_placeholder_p (lhs
))
3902 tree common
= save_expr (lhs
);
3904 if (0 != (lhs
= build_range_check (TREE_TYPE (exp
), common
,
3905 or_op
? ! in0_p
: in0_p
,
3907 && (0 != (rhs
= build_range_check (TREE_TYPE (exp
), common
,
3908 or_op
? ! in1_p
: in1_p
,
3910 return build (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3911 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
3912 TREE_TYPE (exp
), lhs
, rhs
);
3919 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3920 bit value. Arrange things so the extra bits will be set to zero if and
3921 only if C is signed-extended to its full width. If MASK is nonzero,
3922 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3925 unextend (c
, p
, unsignedp
, mask
)
3931 tree type
= TREE_TYPE (c
);
3932 int modesize
= GET_MODE_BITSIZE (TYPE_MODE (type
));
3935 if (p
== modesize
|| unsignedp
)
3938 /* We work by getting just the sign bit into the low-order bit, then
3939 into the high-order bit, then sign-extend. We then XOR that value
3941 temp
= const_binop (RSHIFT_EXPR
, c
, size_int (p
- 1), 0);
3942 temp
= const_binop (BIT_AND_EXPR
, temp
, size_int (1), 0);
3944 /* We must use a signed type in order to get an arithmetic right shift.
3945 However, we must also avoid introducing accidental overflows, so that
3946 a subsequent call to integer_zerop will work. Hence we must
3947 do the type conversion here. At this point, the constant is either
3948 zero or one, and the conversion to a signed type can never overflow.
3949 We could get an overflow if this conversion is done anywhere else. */
3950 if (TREE_UNSIGNED (type
))
3951 temp
= convert (signed_type (type
), temp
);
3953 temp
= const_binop (LSHIFT_EXPR
, temp
, size_int (modesize
- 1), 0);
3954 temp
= const_binop (RSHIFT_EXPR
, temp
, size_int (modesize
- p
- 1), 0);
3956 temp
= const_binop (BIT_AND_EXPR
, temp
, convert (TREE_TYPE (c
), mask
), 0);
3957 /* If necessary, convert the type back to match the type of C. */
3958 if (TREE_UNSIGNED (type
))
3959 temp
= convert (type
, temp
);
3961 return convert (type
, const_binop (BIT_XOR_EXPR
, c
, temp
, 0));
3964 /* Find ways of folding logical expressions of LHS and RHS:
3965 Try to merge two comparisons to the same innermost item.
3966 Look for range tests like "ch >= '0' && ch <= '9'".
3967 Look for combinations of simple terms on machines with expensive branches
3968 and evaluate the RHS unconditionally.
3970 For example, if we have p->a == 2 && p->b == 4 and we can make an
3971 object large enough to span both A and B, we can do this with a comparison
3972 against the object ANDed with the a mask.
3974 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3975 operations to do this with one comparison.
3977 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3978 function and the one above.
3980 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3981 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3983 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3986 We return the simplified tree or 0 if no optimization is possible. */
3989 fold_truthop (code
, truth_type
, lhs
, rhs
)
3990 enum tree_code code
;
3991 tree truth_type
, lhs
, rhs
;
3993 /* If this is the "or" of two comparisons, we can do something if
3994 the comparisons are NE_EXPR. If this is the "and", we can do something
3995 if the comparisons are EQ_EXPR. I.e.,
3996 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3998 WANTED_CODE is this operation code. For single bit fields, we can
3999 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
4000 comparison for one-bit fields. */
4002 enum tree_code wanted_code
;
4003 enum tree_code lcode
, rcode
;
4004 tree ll_arg
, lr_arg
, rl_arg
, rr_arg
;
4005 tree ll_inner
, lr_inner
, rl_inner
, rr_inner
;
4006 HOST_WIDE_INT ll_bitsize
, ll_bitpos
, lr_bitsize
, lr_bitpos
;
4007 HOST_WIDE_INT rl_bitsize
, rl_bitpos
, rr_bitsize
, rr_bitpos
;
4008 HOST_WIDE_INT xll_bitpos
, xlr_bitpos
, xrl_bitpos
, xrr_bitpos
;
4009 HOST_WIDE_INT lnbitsize
, lnbitpos
, rnbitsize
, rnbitpos
;
4010 int ll_unsignedp
, lr_unsignedp
, rl_unsignedp
, rr_unsignedp
;
4011 enum machine_mode ll_mode
, lr_mode
, rl_mode
, rr_mode
;
4012 enum machine_mode lnmode
, rnmode
;
4013 tree ll_mask
, lr_mask
, rl_mask
, rr_mask
;
4014 tree ll_and_mask
, lr_and_mask
, rl_and_mask
, rr_and_mask
;
4015 tree l_const
, r_const
;
4016 tree lntype
, rntype
, result
;
4017 int first_bit
, end_bit
;
4020 /* Start by getting the comparison codes. Fail if anything is volatile.
4021 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
4022 it were surrounded with a NE_EXPR. */
4024 if (TREE_SIDE_EFFECTS (lhs
) || TREE_SIDE_EFFECTS (rhs
))
4027 lcode
= TREE_CODE (lhs
);
4028 rcode
= TREE_CODE (rhs
);
4030 if (lcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (lhs
, 1)))
4031 lcode
= NE_EXPR
, lhs
= build (NE_EXPR
, truth_type
, lhs
, integer_zero_node
);
4033 if (rcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (rhs
, 1)))
4034 rcode
= NE_EXPR
, rhs
= build (NE_EXPR
, truth_type
, rhs
, integer_zero_node
);
4036 if (TREE_CODE_CLASS (lcode
) != '<' || TREE_CODE_CLASS (rcode
) != '<')
4039 code
= ((code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
)
4040 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
);
4042 ll_arg
= TREE_OPERAND (lhs
, 0);
4043 lr_arg
= TREE_OPERAND (lhs
, 1);
4044 rl_arg
= TREE_OPERAND (rhs
, 0);
4045 rr_arg
= TREE_OPERAND (rhs
, 1);
4047 /* If the RHS can be evaluated unconditionally and its operands are
4048 simple, it wins to evaluate the RHS unconditionally on machines
4049 with expensive branches. In this case, this isn't a comparison
4050 that can be merged. Avoid doing this if the RHS is a floating-point
4051 comparison since those can trap. */
4053 if (BRANCH_COST
>= 2
4054 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg
))
4055 && simple_operand_p (rl_arg
)
4056 && simple_operand_p (rr_arg
))
4057 return build (code
, truth_type
, lhs
, rhs
);
4059 /* See if the comparisons can be merged. Then get all the parameters for
4062 if ((lcode
!= EQ_EXPR
&& lcode
!= NE_EXPR
)
4063 || (rcode
!= EQ_EXPR
&& rcode
!= NE_EXPR
))
4067 ll_inner
= decode_field_reference (ll_arg
,
4068 &ll_bitsize
, &ll_bitpos
, &ll_mode
,
4069 &ll_unsignedp
, &volatilep
, &ll_mask
,
4071 lr_inner
= decode_field_reference (lr_arg
,
4072 &lr_bitsize
, &lr_bitpos
, &lr_mode
,
4073 &lr_unsignedp
, &volatilep
, &lr_mask
,
4075 rl_inner
= decode_field_reference (rl_arg
,
4076 &rl_bitsize
, &rl_bitpos
, &rl_mode
,
4077 &rl_unsignedp
, &volatilep
, &rl_mask
,
4079 rr_inner
= decode_field_reference (rr_arg
,
4080 &rr_bitsize
, &rr_bitpos
, &rr_mode
,
4081 &rr_unsignedp
, &volatilep
, &rr_mask
,
4084 /* It must be true that the inner operation on the lhs of each
4085 comparison must be the same if we are to be able to do anything.
4086 Then see if we have constants. If not, the same must be true for
4088 if (volatilep
|| ll_inner
== 0 || rl_inner
== 0
4089 || ! operand_equal_p (ll_inner
, rl_inner
, 0))
4092 if (TREE_CODE (lr_arg
) == INTEGER_CST
4093 && TREE_CODE (rr_arg
) == INTEGER_CST
)
4094 l_const
= lr_arg
, r_const
= rr_arg
;
4095 else if (lr_inner
== 0 || rr_inner
== 0
4096 || ! operand_equal_p (lr_inner
, rr_inner
, 0))
4099 l_const
= r_const
= 0;
4101 /* If either comparison code is not correct for our logical operation,
4102 fail. However, we can convert a one-bit comparison against zero into
4103 the opposite comparison against that bit being set in the field. */
4105 wanted_code
= (code
== TRUTH_AND_EXPR
? EQ_EXPR
: NE_EXPR
);
4106 if (lcode
!= wanted_code
)
4108 if (l_const
&& integer_zerop (l_const
) && integer_pow2p (ll_mask
))
4110 /* Make the left operand unsigned, since we are only interested
4111 in the value of one bit. Otherwise we are doing the wrong
4120 /* This is analogous to the code for l_const above. */
4121 if (rcode
!= wanted_code
)
4123 if (r_const
&& integer_zerop (r_const
) && integer_pow2p (rl_mask
))
4132 /* See if we can find a mode that contains both fields being compared on
4133 the left. If we can't, fail. Otherwise, update all constants and masks
4134 to be relative to a field of that size. */
4135 first_bit
= MIN (ll_bitpos
, rl_bitpos
);
4136 end_bit
= MAX (ll_bitpos
+ ll_bitsize
, rl_bitpos
+ rl_bitsize
);
4137 lnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
4138 TYPE_ALIGN (TREE_TYPE (ll_inner
)), word_mode
,
4140 if (lnmode
== VOIDmode
)
4143 lnbitsize
= GET_MODE_BITSIZE (lnmode
);
4144 lnbitpos
= first_bit
& ~ (lnbitsize
- 1);
4145 lntype
= type_for_size (lnbitsize
, 1);
4146 xll_bitpos
= ll_bitpos
- lnbitpos
, xrl_bitpos
= rl_bitpos
- lnbitpos
;
4148 if (BYTES_BIG_ENDIAN
)
4150 xll_bitpos
= lnbitsize
- xll_bitpos
- ll_bitsize
;
4151 xrl_bitpos
= lnbitsize
- xrl_bitpos
- rl_bitsize
;
4154 ll_mask
= const_binop (LSHIFT_EXPR
, convert (lntype
, ll_mask
),
4155 size_int (xll_bitpos
), 0);
4156 rl_mask
= const_binop (LSHIFT_EXPR
, convert (lntype
, rl_mask
),
4157 size_int (xrl_bitpos
), 0);
4161 l_const
= convert (lntype
, l_const
);
4162 l_const
= unextend (l_const
, ll_bitsize
, ll_unsignedp
, ll_and_mask
);
4163 l_const
= const_binop (LSHIFT_EXPR
, l_const
, size_int (xll_bitpos
), 0);
4164 if (! integer_zerop (const_binop (BIT_AND_EXPR
, l_const
,
4165 fold (build1 (BIT_NOT_EXPR
,
4169 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
4171 return convert (truth_type
,
4172 wanted_code
== NE_EXPR
4173 ? integer_one_node
: integer_zero_node
);
4178 r_const
= convert (lntype
, r_const
);
4179 r_const
= unextend (r_const
, rl_bitsize
, rl_unsignedp
, rl_and_mask
);
4180 r_const
= const_binop (LSHIFT_EXPR
, r_const
, size_int (xrl_bitpos
), 0);
4181 if (! integer_zerop (const_binop (BIT_AND_EXPR
, r_const
,
4182 fold (build1 (BIT_NOT_EXPR
,
4186 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
4188 return convert (truth_type
,
4189 wanted_code
== NE_EXPR
4190 ? integer_one_node
: integer_zero_node
);
4194 /* If the right sides are not constant, do the same for it. Also,
4195 disallow this optimization if a size or signedness mismatch occurs
4196 between the left and right sides. */
4199 if (ll_bitsize
!= lr_bitsize
|| rl_bitsize
!= rr_bitsize
4200 || ll_unsignedp
!= lr_unsignedp
|| rl_unsignedp
!= rr_unsignedp
4201 /* Make sure the two fields on the right
4202 correspond to the left without being swapped. */
4203 || ll_bitpos
- rl_bitpos
!= lr_bitpos
- rr_bitpos
)
4206 first_bit
= MIN (lr_bitpos
, rr_bitpos
);
4207 end_bit
= MAX (lr_bitpos
+ lr_bitsize
, rr_bitpos
+ rr_bitsize
);
4208 rnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
4209 TYPE_ALIGN (TREE_TYPE (lr_inner
)), word_mode
,
4211 if (rnmode
== VOIDmode
)
4214 rnbitsize
= GET_MODE_BITSIZE (rnmode
);
4215 rnbitpos
= first_bit
& ~ (rnbitsize
- 1);
4216 rntype
= type_for_size (rnbitsize
, 1);
4217 xlr_bitpos
= lr_bitpos
- rnbitpos
, xrr_bitpos
= rr_bitpos
- rnbitpos
;
4219 if (BYTES_BIG_ENDIAN
)
4221 xlr_bitpos
= rnbitsize
- xlr_bitpos
- lr_bitsize
;
4222 xrr_bitpos
= rnbitsize
- xrr_bitpos
- rr_bitsize
;
4225 lr_mask
= const_binop (LSHIFT_EXPR
, convert (rntype
, lr_mask
),
4226 size_int (xlr_bitpos
), 0);
4227 rr_mask
= const_binop (LSHIFT_EXPR
, convert (rntype
, rr_mask
),
4228 size_int (xrr_bitpos
), 0);
4230 /* Make a mask that corresponds to both fields being compared.
4231 Do this for both items being compared. If the operands are the
4232 same size and the bits being compared are in the same position
4233 then we can do this by masking both and comparing the masked
4235 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
4236 lr_mask
= const_binop (BIT_IOR_EXPR
, lr_mask
, rr_mask
, 0);
4237 if (lnbitsize
== rnbitsize
&& xll_bitpos
== xlr_bitpos
)
4239 lhs
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
4240 ll_unsignedp
|| rl_unsignedp
);
4241 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
4242 lhs
= build (BIT_AND_EXPR
, lntype
, lhs
, ll_mask
);
4244 rhs
= make_bit_field_ref (lr_inner
, rntype
, rnbitsize
, rnbitpos
,
4245 lr_unsignedp
|| rr_unsignedp
);
4246 if (! all_ones_mask_p (lr_mask
, rnbitsize
))
4247 rhs
= build (BIT_AND_EXPR
, rntype
, rhs
, lr_mask
);
4249 return build (wanted_code
, truth_type
, lhs
, rhs
);
4252 /* There is still another way we can do something: If both pairs of
4253 fields being compared are adjacent, we may be able to make a wider
4254 field containing them both.
4256 Note that we still must mask the lhs/rhs expressions. Furthermore,
4257 the mask must be shifted to account for the shift done by
4258 make_bit_field_ref. */
4259 if ((ll_bitsize
+ ll_bitpos
== rl_bitpos
4260 && lr_bitsize
+ lr_bitpos
== rr_bitpos
)
4261 || (ll_bitpos
== rl_bitpos
+ rl_bitsize
4262 && lr_bitpos
== rr_bitpos
+ rr_bitsize
))
4266 lhs
= make_bit_field_ref (ll_inner
, lntype
, ll_bitsize
+ rl_bitsize
,
4267 MIN (ll_bitpos
, rl_bitpos
), ll_unsignedp
);
4268 rhs
= make_bit_field_ref (lr_inner
, rntype
, lr_bitsize
+ rr_bitsize
,
4269 MIN (lr_bitpos
, rr_bitpos
), lr_unsignedp
);
4271 ll_mask
= const_binop (RSHIFT_EXPR
, ll_mask
,
4272 size_int (MIN (xll_bitpos
, xrl_bitpos
)), 0);
4273 lr_mask
= const_binop (RSHIFT_EXPR
, lr_mask
,
4274 size_int (MIN (xlr_bitpos
, xrr_bitpos
)), 0);
4276 /* Convert to the smaller type before masking out unwanted bits. */
4278 if (lntype
!= rntype
)
4280 if (lnbitsize
> rnbitsize
)
4282 lhs
= convert (rntype
, lhs
);
4283 ll_mask
= convert (rntype
, ll_mask
);
4286 else if (lnbitsize
< rnbitsize
)
4288 rhs
= convert (lntype
, rhs
);
4289 lr_mask
= convert (lntype
, lr_mask
);
4294 if (! all_ones_mask_p (ll_mask
, ll_bitsize
+ rl_bitsize
))
4295 lhs
= build (BIT_AND_EXPR
, type
, lhs
, ll_mask
);
4297 if (! all_ones_mask_p (lr_mask
, lr_bitsize
+ rr_bitsize
))
4298 rhs
= build (BIT_AND_EXPR
, type
, rhs
, lr_mask
);
4300 return build (wanted_code
, truth_type
, lhs
, rhs
);
4306 /* Handle the case of comparisons with constants. If there is something in
4307 common between the masks, those bits of the constants must be the same.
4308 If not, the condition is always false. Test for this to avoid generating
4309 incorrect code below. */
4310 result
= const_binop (BIT_AND_EXPR
, ll_mask
, rl_mask
, 0);
4311 if (! integer_zerop (result
)
4312 && simple_cst_equal (const_binop (BIT_AND_EXPR
, result
, l_const
, 0),
4313 const_binop (BIT_AND_EXPR
, result
, r_const
, 0)) != 1)
4315 if (wanted_code
== NE_EXPR
)
4317 warning ("`or' of unmatched not-equal tests is always 1");
4318 return convert (truth_type
, integer_one_node
);
4322 warning ("`and' of mutually exclusive equal-tests is always 0");
4323 return convert (truth_type
, integer_zero_node
);
4327 /* Construct the expression we will return. First get the component
4328 reference we will make. Unless the mask is all ones the width of
4329 that field, perform the mask operation. Then compare with the
4331 result
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
4332 ll_unsignedp
|| rl_unsignedp
);
4334 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
4335 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
4336 result
= build (BIT_AND_EXPR
, lntype
, result
, ll_mask
);
4338 return build (wanted_code
, truth_type
, result
,
4339 const_binop (BIT_IOR_EXPR
, l_const
, r_const
, 0));
4342 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4346 optimize_minmax_comparison (t
)
4349 tree type
= TREE_TYPE (t
);
4350 tree arg0
= TREE_OPERAND (t
, 0);
4351 enum tree_code op_code
;
4352 tree comp_const
= TREE_OPERAND (t
, 1);
4354 int consts_equal
, consts_lt
;
4357 STRIP_SIGN_NOPS (arg0
);
4359 op_code
= TREE_CODE (arg0
);
4360 minmax_const
= TREE_OPERAND (arg0
, 1);
4361 consts_equal
= tree_int_cst_equal (minmax_const
, comp_const
);
4362 consts_lt
= tree_int_cst_lt (minmax_const
, comp_const
);
4363 inner
= TREE_OPERAND (arg0
, 0);
4365 /* If something does not permit us to optimize, return the original tree. */
4366 if ((op_code
!= MIN_EXPR
&& op_code
!= MAX_EXPR
)
4367 || TREE_CODE (comp_const
) != INTEGER_CST
4368 || TREE_CONSTANT_OVERFLOW (comp_const
)
4369 || TREE_CODE (minmax_const
) != INTEGER_CST
4370 || TREE_CONSTANT_OVERFLOW (minmax_const
))
4373 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4374 and GT_EXPR, doing the rest with recursive calls using logical
4376 switch (TREE_CODE (t
))
4378 case NE_EXPR
: case LT_EXPR
: case LE_EXPR
:
4380 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t
)));
4384 fold (build (TRUTH_ORIF_EXPR
, type
,
4385 optimize_minmax_comparison
4386 (build (EQ_EXPR
, type
, arg0
, comp_const
)),
4387 optimize_minmax_comparison
4388 (build (GT_EXPR
, type
, arg0
, comp_const
))));
4391 if (op_code
== MAX_EXPR
&& consts_equal
)
4392 /* MAX (X, 0) == 0 -> X <= 0 */
4393 return fold (build (LE_EXPR
, type
, inner
, comp_const
));
4395 else if (op_code
== MAX_EXPR
&& consts_lt
)
4396 /* MAX (X, 0) == 5 -> X == 5 */
4397 return fold (build (EQ_EXPR
, type
, inner
, comp_const
));
4399 else if (op_code
== MAX_EXPR
)
4400 /* MAX (X, 0) == -1 -> false */
4401 return omit_one_operand (type
, integer_zero_node
, inner
);
4403 else if (consts_equal
)
4404 /* MIN (X, 0) == 0 -> X >= 0 */
4405 return fold (build (GE_EXPR
, type
, inner
, comp_const
));
4408 /* MIN (X, 0) == 5 -> false */
4409 return omit_one_operand (type
, integer_zero_node
, inner
);
4412 /* MIN (X, 0) == -1 -> X == -1 */
4413 return fold (build (EQ_EXPR
, type
, inner
, comp_const
));
4416 if (op_code
== MAX_EXPR
&& (consts_equal
|| consts_lt
))
4417 /* MAX (X, 0) > 0 -> X > 0
4418 MAX (X, 0) > 5 -> X > 5 */
4419 return fold (build (GT_EXPR
, type
, inner
, comp_const
));
4421 else if (op_code
== MAX_EXPR
)
4422 /* MAX (X, 0) > -1 -> true */
4423 return omit_one_operand (type
, integer_one_node
, inner
);
4425 else if (op_code
== MIN_EXPR
&& (consts_equal
|| consts_lt
))
4426 /* MIN (X, 0) > 0 -> false
4427 MIN (X, 0) > 5 -> false */
4428 return omit_one_operand (type
, integer_zero_node
, inner
);
4431 /* MIN (X, 0) > -1 -> X > -1 */
4432 return fold (build (GT_EXPR
, type
, inner
, comp_const
));
4439 /* T is an integer expression that is being multiplied, divided, or taken a
4440 modulus (CODE says which and what kind of divide or modulus) by a
4441 constant C. See if we can eliminate that operation by folding it with
4442 other operations already in T. WIDE_TYPE, if non-null, is a type that
4443 should be used for the computation if wider than our type.
4445 For example, if we are dividing (X * 8) + (Y + 16) by 4, we can return
4446 (X * 2) + (Y + 4). We must, however, be assured that either the original
4447 expression would not overflow or that overflow is undefined for the type
4448 in the language in question.
4450 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4451 the machine has a multiply-accumulate insn or that this is part of an
4452 addressing calculation.
4454 If we return a non-null expression, it is an equivalent form of the
4455 original computation, but need not be in the original type. */
4458 extract_muldiv (t
, c
, code
, wide_type
)
4461 enum tree_code code
;
4464 tree type
= TREE_TYPE (t
);
4465 enum tree_code tcode
= TREE_CODE (t
);
4466 tree ctype
= (wide_type
!= 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type
))
4467 > GET_MODE_SIZE (TYPE_MODE (type
)))
4468 ? wide_type
: type
);
4470 int same_p
= tcode
== code
;
4471 tree op0
= NULL_TREE
, op1
= NULL_TREE
;
4473 /* Don't deal with constants of zero here; they confuse the code below. */
4474 if (integer_zerop (c
))
4477 if (TREE_CODE_CLASS (tcode
) == '1')
4478 op0
= TREE_OPERAND (t
, 0);
4480 if (TREE_CODE_CLASS (tcode
) == '2')
4481 op0
= TREE_OPERAND (t
, 0), op1
= TREE_OPERAND (t
, 1);
4483 /* Note that we need not handle conditional operations here since fold
4484 already handles those cases. So just do arithmetic here. */
4488 /* For a constant, we can always simplify if we are a multiply
4489 or (for divide and modulus) if it is a multiple of our constant. */
4490 if (code
== MULT_EXPR
4491 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, t
, c
, 0)))
4492 return const_binop (code
, convert (ctype
, t
), convert (ctype
, c
), 0);
4495 case CONVERT_EXPR
: case NON_LVALUE_EXPR
: case NOP_EXPR
:
4496 /* If op0 is an expression, and is unsigned, and the type is
4497 smaller than ctype, then we cannot widen the expression. */
4498 if ((TREE_CODE_CLASS (TREE_CODE (op0
)) == '<'
4499 || TREE_CODE_CLASS (TREE_CODE (op0
)) == '1'
4500 || TREE_CODE_CLASS (TREE_CODE (op0
)) == '2'
4501 || TREE_CODE_CLASS (TREE_CODE (op0
)) == 'e')
4502 && TREE_UNSIGNED (TREE_TYPE (op0
))
4503 && ! (TREE_CODE (TREE_TYPE (op0
)) == INTEGER_TYPE
4504 && TYPE_IS_SIZETYPE (TREE_TYPE (op0
)))
4505 && (GET_MODE_SIZE (TYPE_MODE (ctype
))
4506 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
)))))
4509 /* Pass the constant down and see if we can make a simplification. If
4510 we can, replace this expression with the inner simplification for
4511 possible later conversion to our or some other type. */
4512 if (0 != (t1
= extract_muldiv (op0
, convert (TREE_TYPE (op0
), c
), code
,
4513 code
== MULT_EXPR
? ctype
: NULL_TREE
)))
4517 case NEGATE_EXPR
: case ABS_EXPR
:
4518 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
4519 return fold (build1 (tcode
, ctype
, convert (ctype
, t1
)));
4522 case MIN_EXPR
: case MAX_EXPR
:
4523 /* If widening the type changes the signedness, then we can't perform
4524 this optimization as that changes the result. */
4525 if (TREE_UNSIGNED (ctype
) != TREE_UNSIGNED (type
))
4528 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4529 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0
4530 && (t2
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
4532 if (tree_int_cst_sgn (c
) < 0)
4533 tcode
= (tcode
== MIN_EXPR
? MAX_EXPR
: MIN_EXPR
);
4535 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4536 convert (ctype
, t2
)));
4540 case WITH_RECORD_EXPR
:
4541 if ((t1
= extract_muldiv (TREE_OPERAND (t
, 0), c
, code
, wide_type
)) != 0)
4542 return build (WITH_RECORD_EXPR
, TREE_TYPE (t1
), t1
,
4543 TREE_OPERAND (t
, 1));
4547 /* If this has not been evaluated and the operand has no side effects,
4548 we can see if we can do something inside it and make a new one.
4549 Note that this test is overly conservative since we can do this
4550 if the only reason it had side effects is that it was another
4551 similar SAVE_EXPR, but that isn't worth bothering with. */
4552 if (SAVE_EXPR_RTL (t
) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 0))
4553 && 0 != (t1
= extract_muldiv (TREE_OPERAND (t
, 0), c
, code
,
4556 t1
= save_expr (t1
);
4557 if (SAVE_EXPR_PERSISTENT_P (t
) && TREE_CODE (t1
) == SAVE_EXPR
)
4558 SAVE_EXPR_PERSISTENT_P (t1
) = 1;
4559 if (is_pending_size (t
))
4560 put_pending_size (t1
);
4565 case LSHIFT_EXPR
: case RSHIFT_EXPR
:
4566 /* If the second operand is constant, this is a multiplication
4567 or floor division, by a power of two, so we can treat it that
4568 way unless the multiplier or divisor overflows. */
4569 if (TREE_CODE (op1
) == INTEGER_CST
4570 /* const_binop may not detect overflow correctly,
4571 so check for it explicitly here. */
4572 && TYPE_PRECISION (TREE_TYPE (size_one_node
)) > TREE_INT_CST_LOW (op1
)
4573 && TREE_INT_CST_HIGH (op1
) == 0
4574 && 0 != (t1
= convert (ctype
,
4575 const_binop (LSHIFT_EXPR
, size_one_node
,
4577 && ! TREE_OVERFLOW (t1
))
4578 return extract_muldiv (build (tcode
== LSHIFT_EXPR
4579 ? MULT_EXPR
: FLOOR_DIV_EXPR
,
4580 ctype
, convert (ctype
, op0
), t1
),
4581 c
, code
, wide_type
);
4584 case PLUS_EXPR
: case MINUS_EXPR
:
4585 /* See if we can eliminate the operation on both sides. If we can, we
4586 can return a new PLUS or MINUS. If we can't, the only remaining
4587 cases where we can do anything are if the second operand is a
4589 t1
= extract_muldiv (op0
, c
, code
, wide_type
);
4590 t2
= extract_muldiv (op1
, c
, code
, wide_type
);
4591 if (t1
!= 0 && t2
!= 0
4592 && (code
== MULT_EXPR
4593 /* If not multiplication, we can only do this if either operand
4594 is divisible by c. */
4595 || multiple_of_p (ctype
, op0
, c
)
4596 || multiple_of_p (ctype
, op1
, c
)))
4597 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4598 convert (ctype
, t2
)));
4600 /* If this was a subtraction, negate OP1 and set it to be an addition.
4601 This simplifies the logic below. */
4602 if (tcode
== MINUS_EXPR
)
4603 tcode
= PLUS_EXPR
, op1
= negate_expr (op1
);
4605 if (TREE_CODE (op1
) != INTEGER_CST
)
4608 /* If either OP1 or C are negative, this optimization is not safe for
4609 some of the division and remainder types while for others we need
4610 to change the code. */
4611 if (tree_int_cst_sgn (op1
) < 0 || tree_int_cst_sgn (c
) < 0)
4613 if (code
== CEIL_DIV_EXPR
)
4614 code
= FLOOR_DIV_EXPR
;
4615 else if (code
== FLOOR_DIV_EXPR
)
4616 code
= CEIL_DIV_EXPR
;
4617 else if (code
!= MULT_EXPR
4618 && code
!= CEIL_MOD_EXPR
&& code
!= FLOOR_MOD_EXPR
)
4622 /* If it's a multiply or a division/modulus operation of a multiple
4623 of our constant, do the operation and verify it doesn't overflow. */
4624 if (code
== MULT_EXPR
4625 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4627 op1
= const_binop (code
, convert (ctype
, op1
), convert (ctype
, c
), 0);
4628 if (op1
== 0 || TREE_OVERFLOW (op1
))
4634 /* If we have an unsigned type is not a sizetype, we cannot widen
4635 the operation since it will change the result if the original
4636 computation overflowed. */
4637 if (TREE_UNSIGNED (ctype
)
4638 && ! (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
))
4642 /* If we were able to eliminate our operation from the first side,
4643 apply our operation to the second side and reform the PLUS. */
4644 if (t1
!= 0 && (TREE_CODE (t1
) != code
|| code
== MULT_EXPR
))
4645 return fold (build (tcode
, ctype
, convert (ctype
, t1
), op1
));
4647 /* The last case is if we are a multiply. In that case, we can
4648 apply the distributive law to commute the multiply and addition
4649 if the multiplication of the constants doesn't overflow. */
4650 if (code
== MULT_EXPR
)
4651 return fold (build (tcode
, ctype
, fold (build (code
, ctype
,
4652 convert (ctype
, op0
),
4653 convert (ctype
, c
))),
4659 /* We have a special case here if we are doing something like
4660 (C * 8) % 4 since we know that's zero. */
4661 if ((code
== TRUNC_MOD_EXPR
|| code
== CEIL_MOD_EXPR
4662 || code
== FLOOR_MOD_EXPR
|| code
== ROUND_MOD_EXPR
)
4663 && TREE_CODE (TREE_OPERAND (t
, 1)) == INTEGER_CST
4664 && integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4665 return omit_one_operand (type
, integer_zero_node
, op0
);
4667 /* ... fall through ... */
4669 case TRUNC_DIV_EXPR
: case CEIL_DIV_EXPR
: case FLOOR_DIV_EXPR
:
4670 case ROUND_DIV_EXPR
: case EXACT_DIV_EXPR
:
4671 /* If we can extract our operation from the LHS, do so and return a
4672 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4673 do something only if the second operand is a constant. */
4675 && (t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
4676 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4677 convert (ctype
, op1
)));
4678 else if (tcode
== MULT_EXPR
&& code
== MULT_EXPR
4679 && (t1
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
4680 return fold (build (tcode
, ctype
, convert (ctype
, op0
),
4681 convert (ctype
, t1
)));
4682 else if (TREE_CODE (op1
) != INTEGER_CST
)
4685 /* If these are the same operation types, we can associate them
4686 assuming no overflow. */
4688 && 0 != (t1
= const_binop (MULT_EXPR
, convert (ctype
, op1
),
4689 convert (ctype
, c
), 0))
4690 && ! TREE_OVERFLOW (t1
))
4691 return fold (build (tcode
, ctype
, convert (ctype
, op0
), t1
));
4693 /* If these operations "cancel" each other, we have the main
4694 optimizations of this pass, which occur when either constant is a
4695 multiple of the other, in which case we replace this with either an
4696 operation or CODE or TCODE.
4698 If we have an unsigned type that is not a sizetype, we cannot do
4699 this since it will change the result if the original computation
4701 if ((! TREE_UNSIGNED (ctype
)
4702 || (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
)))
4703 && ((code
== MULT_EXPR
&& tcode
== EXACT_DIV_EXPR
)
4704 || (tcode
== MULT_EXPR
4705 && code
!= TRUNC_MOD_EXPR
&& code
!= CEIL_MOD_EXPR
4706 && code
!= FLOOR_MOD_EXPR
&& code
!= ROUND_MOD_EXPR
)))
4708 if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4709 return fold (build (tcode
, ctype
, convert (ctype
, op0
),
4711 const_binop (TRUNC_DIV_EXPR
,
4713 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, c
, op1
, 0)))
4714 return fold (build (code
, ctype
, convert (ctype
, op0
),
4716 const_binop (TRUNC_DIV_EXPR
,
4728 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4729 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4730 that we may sometimes modify the tree. */
4733 strip_compound_expr (t
, s
)
4737 enum tree_code code
= TREE_CODE (t
);
4739 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4740 if (code
== COMPOUND_EXPR
&& TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
4741 && TREE_OPERAND (TREE_OPERAND (t
, 0), 0) == s
)
4742 return TREE_OPERAND (t
, 1);
4744 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4745 don't bother handling any other types. */
4746 else if (code
== COND_EXPR
)
4748 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4749 TREE_OPERAND (t
, 1) = strip_compound_expr (TREE_OPERAND (t
, 1), s
);
4750 TREE_OPERAND (t
, 2) = strip_compound_expr (TREE_OPERAND (t
, 2), s
);
4752 else if (TREE_CODE_CLASS (code
) == '1')
4753 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4754 else if (TREE_CODE_CLASS (code
) == '<'
4755 || TREE_CODE_CLASS (code
) == '2')
4757 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4758 TREE_OPERAND (t
, 1) = strip_compound_expr (TREE_OPERAND (t
, 1), s
);
4764 /* Return a node which has the indicated constant VALUE (either 0 or
4765 1), and is of the indicated TYPE. */
4768 constant_boolean_node (value
, type
)
4772 if (type
== integer_type_node
)
4773 return value
? integer_one_node
: integer_zero_node
;
4774 else if (TREE_CODE (type
) == BOOLEAN_TYPE
)
4775 return truthvalue_conversion (value
? integer_one_node
:
4779 tree t
= build_int_2 (value
, 0);
4781 TREE_TYPE (t
) = type
;
4786 /* Utility function for the following routine, to see how complex a nesting of
4787 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4788 we don't care (to avoid spending too much time on complex expressions.). */
4791 count_cond (expr
, lim
)
4797 if (TREE_CODE (expr
) != COND_EXPR
)
4802 ctrue
= count_cond (TREE_OPERAND (expr
, 1), lim
- 1);
4803 cfalse
= count_cond (TREE_OPERAND (expr
, 2), lim
- 1 - ctrue
);
4804 return MIN (lim
, 1 + ctrue
+ cfalse
);
4807 /* Transform `a + (b ? x : y)' into `x ? (a + b) : (a + y)'.
4808 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4809 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4810 expression, and ARG to `a'. If COND_FIRST_P is non-zero, then the
4811 COND is the first argument to CODE; otherwise (as in the example
4812 given here), it is the second argument. TYPE is the type of the
4813 original expression. */
4816 fold_binary_op_with_conditional_arg (code
, type
, cond
, arg
, cond_first_p
)
4817 enum tree_code code
;
4823 tree test
, true_value
, false_value
;
4824 tree lhs
= NULL_TREE
;
4825 tree rhs
= NULL_TREE
;
4826 /* In the end, we'll produce a COND_EXPR. Both arms of the
4827 conditional expression will be binary operations. The left-hand
4828 side of the expression to be executed if the condition is true
4829 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4830 of the expression to be executed if the condition is true will be
4831 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4832 but apply to the expression to be executed if the conditional is
4838 /* These are the codes to use for the left-hand side and right-hand
4839 side of the COND_EXPR. Normally, they are the same as CODE. */
4840 enum tree_code lhs_code
= code
;
4841 enum tree_code rhs_code
= code
;
4842 /* And these are the types of the expressions. */
4843 tree lhs_type
= type
;
4844 tree rhs_type
= type
;
4848 true_rhs
= false_rhs
= &arg
;
4849 true_lhs
= &true_value
;
4850 false_lhs
= &false_value
;
4854 true_lhs
= false_lhs
= &arg
;
4855 true_rhs
= &true_value
;
4856 false_rhs
= &false_value
;
4859 if (TREE_CODE (cond
) == COND_EXPR
)
4861 test
= TREE_OPERAND (cond
, 0);
4862 true_value
= TREE_OPERAND (cond
, 1);
4863 false_value
= TREE_OPERAND (cond
, 2);
4864 /* If this operand throws an expression, then it does not make
4865 sense to try to perform a logical or arithmetic operation
4866 involving it. Instead of building `a + throw 3' for example,
4867 we simply build `a, throw 3'. */
4868 if (VOID_TYPE_P (TREE_TYPE (true_value
)))
4870 lhs_code
= COMPOUND_EXPR
;
4872 lhs_type
= void_type_node
;
4874 if (VOID_TYPE_P (TREE_TYPE (false_value
)))
4876 rhs_code
= COMPOUND_EXPR
;
4878 rhs_type
= void_type_node
;
4883 tree testtype
= TREE_TYPE (cond
);
4885 true_value
= convert (testtype
, integer_one_node
);
4886 false_value
= convert (testtype
, integer_zero_node
);
4889 /* If ARG is complex we want to make sure we only evaluate
4890 it once. Though this is only required if it is volatile, it
4891 might be more efficient even if it is not. However, if we
4892 succeed in folding one part to a constant, we do not need
4893 to make this SAVE_EXPR. Since we do this optimization
4894 primarily to see if we do end up with constant and this
4895 SAVE_EXPR interferes with later optimizations, suppressing
4896 it when we can is important.
4898 If we are not in a function, we can't make a SAVE_EXPR, so don't
4899 try to do so. Don't try to see if the result is a constant
4900 if an arm is a COND_EXPR since we get exponential behavior
4903 if (TREE_CODE (arg
) != SAVE_EXPR
&& ! TREE_CONSTANT (arg
)
4904 && global_bindings_p () == 0
4905 && ((TREE_CODE (arg
) != VAR_DECL
4906 && TREE_CODE (arg
) != PARM_DECL
)
4907 || TREE_SIDE_EFFECTS (arg
)))
4909 if (TREE_CODE (true_value
) != COND_EXPR
)
4910 lhs
= fold (build (lhs_code
, lhs_type
, *true_lhs
, *true_rhs
));
4912 if (TREE_CODE (false_value
) != COND_EXPR
)
4913 rhs
= fold (build (rhs_code
, rhs_type
, *false_lhs
, *false_rhs
));
4915 if ((lhs
== 0 || ! TREE_CONSTANT (lhs
))
4916 && (rhs
== 0 || !TREE_CONSTANT (rhs
)))
4917 arg
= save_expr (arg
), lhs
= rhs
= 0;
4921 lhs
= fold (build (lhs_code
, lhs_type
, *true_lhs
, *true_rhs
));
4923 rhs
= fold (build (rhs_code
, rhs_type
, *false_lhs
, *false_rhs
));
4925 test
= fold (build (COND_EXPR
, type
, test
, lhs
, rhs
));
4927 if (TREE_CODE (arg
) == SAVE_EXPR
)
4928 return build (COMPOUND_EXPR
, type
,
4929 convert (void_type_node
, arg
),
4930 strip_compound_expr (test
, arg
));
4932 return convert (type
, test
);
4936 /* Perform constant folding and related simplification of EXPR.
4937 The related simplifications include x*1 => x, x*0 => 0, etc.,
4938 and application of the associative law.
4939 NOP_EXPR conversions may be removed freely (as long as we
4940 are careful not to change the C type of the overall expression)
4941 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4942 but we can constant-fold them if they have constant operands. */
4949 tree t1
= NULL_TREE
;
4951 tree type
= TREE_TYPE (expr
);
4952 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
;
4953 enum tree_code code
= TREE_CODE (t
);
4954 int kind
= TREE_CODE_CLASS (code
);
4956 /* WINS will be nonzero when the switch is done
4957 if all operands are constant. */
4960 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4961 Likewise for a SAVE_EXPR that's already been evaluated. */
4962 if (code
== RTL_EXPR
|| (code
== SAVE_EXPR
&& SAVE_EXPR_RTL (t
) != 0))
4965 /* Return right away if a constant. */
4969 #ifdef MAX_INTEGER_COMPUTATION_MODE
4970 check_max_integer_computation_mode (expr
);
4973 if (code
== NOP_EXPR
|| code
== FLOAT_EXPR
|| code
== CONVERT_EXPR
)
4977 /* Special case for conversion ops that can have fixed point args. */
4978 arg0
= TREE_OPERAND (t
, 0);
4980 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4982 STRIP_SIGN_NOPS (arg0
);
4984 if (arg0
!= 0 && TREE_CODE (arg0
) == COMPLEX_CST
)
4985 subop
= TREE_REALPART (arg0
);
4989 if (subop
!= 0 && TREE_CODE (subop
) != INTEGER_CST
4990 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4991 && TREE_CODE (subop
) != REAL_CST
4992 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4994 /* Note that TREE_CONSTANT isn't enough:
4995 static var addresses are constant but we can't
4996 do arithmetic on them. */
4999 else if (IS_EXPR_CODE_CLASS (kind
) || kind
== 'r')
5001 int len
= first_rtl_op (code
);
5003 for (i
= 0; i
< len
; i
++)
5005 tree op
= TREE_OPERAND (t
, i
);
5009 continue; /* Valid for CALL_EXPR, at least. */
5011 if (kind
== '<' || code
== RSHIFT_EXPR
)
5013 /* Signedness matters here. Perhaps we can refine this
5015 STRIP_SIGN_NOPS (op
);
5018 /* Strip any conversions that don't change the mode. */
5021 if (TREE_CODE (op
) == COMPLEX_CST
)
5022 subop
= TREE_REALPART (op
);
5026 if (TREE_CODE (subop
) != INTEGER_CST
5027 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5028 && TREE_CODE (subop
) != REAL_CST
5029 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5031 /* Note that TREE_CONSTANT isn't enough:
5032 static var addresses are constant but we can't
5033 do arithmetic on them. */
5043 /* If this is a commutative operation, and ARG0 is a constant, move it
5044 to ARG1 to reduce the number of tests below. */
5045 if ((code
== PLUS_EXPR
|| code
== MULT_EXPR
|| code
== MIN_EXPR
5046 || code
== MAX_EXPR
|| code
== BIT_IOR_EXPR
|| code
== BIT_XOR_EXPR
5047 || code
== BIT_AND_EXPR
)
5048 && (TREE_CODE (arg0
) == INTEGER_CST
|| TREE_CODE (arg0
) == REAL_CST
))
5050 tem
= arg0
; arg0
= arg1
; arg1
= tem
;
5052 tem
= TREE_OPERAND (t
, 0); TREE_OPERAND (t
, 0) = TREE_OPERAND (t
, 1);
5053 TREE_OPERAND (t
, 1) = tem
;
5056 /* Now WINS is set as described above,
5057 ARG0 is the first operand of EXPR,
5058 and ARG1 is the second operand (if it has more than one operand).
5060 First check for cases where an arithmetic operation is applied to a
5061 compound, conditional, or comparison operation. Push the arithmetic
5062 operation inside the compound or conditional to see if any folding
5063 can then be done. Convert comparison to conditional for this purpose.
5064 The also optimizes non-constant cases that used to be done in
5067 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
5068 one of the operands is a comparison and the other is a comparison, a
5069 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
5070 code below would make the expression more complex. Change it to a
5071 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
5072 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
5074 if ((code
== BIT_AND_EXPR
|| code
== BIT_IOR_EXPR
5075 || code
== EQ_EXPR
|| code
== NE_EXPR
)
5076 && ((truth_value_p (TREE_CODE (arg0
))
5077 && (truth_value_p (TREE_CODE (arg1
))
5078 || (TREE_CODE (arg1
) == BIT_AND_EXPR
5079 && integer_onep (TREE_OPERAND (arg1
, 1)))))
5080 || (truth_value_p (TREE_CODE (arg1
))
5081 && (truth_value_p (TREE_CODE (arg0
))
5082 || (TREE_CODE (arg0
) == BIT_AND_EXPR
5083 && integer_onep (TREE_OPERAND (arg0
, 1)))))))
5085 t
= fold (build (code
== BIT_AND_EXPR
? TRUTH_AND_EXPR
5086 : code
== BIT_IOR_EXPR
? TRUTH_OR_EXPR
5090 if (code
== EQ_EXPR
)
5091 t
= invert_truthvalue (t
);
5096 if (TREE_CODE_CLASS (code
) == '1')
5098 if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
5099 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5100 fold (build1 (code
, type
, TREE_OPERAND (arg0
, 1))));
5101 else if (TREE_CODE (arg0
) == COND_EXPR
)
5103 t
= fold (build (COND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5104 fold (build1 (code
, type
, TREE_OPERAND (arg0
, 1))),
5105 fold (build1 (code
, type
, TREE_OPERAND (arg0
, 2)))));
5107 /* If this was a conversion, and all we did was to move into
5108 inside the COND_EXPR, bring it back out. But leave it if
5109 it is a conversion from integer to integer and the
5110 result precision is no wider than a word since such a
5111 conversion is cheap and may be optimized away by combine,
5112 while it couldn't if it were outside the COND_EXPR. Then return
5113 so we don't get into an infinite recursion loop taking the
5114 conversion out and then back in. */
5116 if ((code
== NOP_EXPR
|| code
== CONVERT_EXPR
5117 || code
== NON_LVALUE_EXPR
)
5118 && TREE_CODE (t
) == COND_EXPR
5119 && TREE_CODE (TREE_OPERAND (t
, 1)) == code
5120 && TREE_CODE (TREE_OPERAND (t
, 2)) == code
5121 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0))
5122 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 2), 0)))
5123 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t
))
5125 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0))))
5126 && TYPE_PRECISION (TREE_TYPE (t
)) <= BITS_PER_WORD
))
5127 t
= build1 (code
, type
,
5129 TREE_TYPE (TREE_OPERAND
5130 (TREE_OPERAND (t
, 1), 0)),
5131 TREE_OPERAND (t
, 0),
5132 TREE_OPERAND (TREE_OPERAND (t
, 1), 0),
5133 TREE_OPERAND (TREE_OPERAND (t
, 2), 0)));
5136 else if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<')
5137 return fold (build (COND_EXPR
, type
, arg0
,
5138 fold (build1 (code
, type
, integer_one_node
)),
5139 fold (build1 (code
, type
, integer_zero_node
))));
5141 else if (TREE_CODE_CLASS (code
) == '2'
5142 || TREE_CODE_CLASS (code
) == '<')
5144 if (TREE_CODE (arg1
) == COMPOUND_EXPR
)
5145 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
5146 fold (build (code
, type
,
5147 arg0
, TREE_OPERAND (arg1
, 1))));
5148 else if ((TREE_CODE (arg1
) == COND_EXPR
5149 || (TREE_CODE_CLASS (TREE_CODE (arg1
)) == '<'
5150 && TREE_CODE_CLASS (code
) != '<'))
5151 && (TREE_CODE (arg0
) != COND_EXPR
5152 || count_cond (arg0
, 25) + count_cond (arg1
, 25) <= 25)
5153 && (! TREE_SIDE_EFFECTS (arg0
)
5154 || (global_bindings_p () == 0
5155 && ! contains_placeholder_p (arg0
))))
5157 fold_binary_op_with_conditional_arg (code
, type
, arg1
, arg0
,
5158 /*cond_first_p=*/0);
5159 else if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
5160 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5161 fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
5162 else if ((TREE_CODE (arg0
) == COND_EXPR
5163 || (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
5164 && TREE_CODE_CLASS (code
) != '<'))
5165 && (TREE_CODE (arg1
) != COND_EXPR
5166 || count_cond (arg0
, 25) + count_cond (arg1
, 25) <= 25)
5167 && (! TREE_SIDE_EFFECTS (arg1
)
5168 || (global_bindings_p () == 0
5169 && ! contains_placeholder_p (arg1
))))
5171 fold_binary_op_with_conditional_arg (code
, type
, arg0
, arg1
,
5172 /*cond_first_p=*/1);
5174 else if (TREE_CODE_CLASS (code
) == '<'
5175 && TREE_CODE (arg0
) == COMPOUND_EXPR
)
5176 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5177 fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
5178 else if (TREE_CODE_CLASS (code
) == '<'
5179 && TREE_CODE (arg1
) == COMPOUND_EXPR
)
5180 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
5181 fold (build (code
, type
, arg0
, TREE_OPERAND (arg1
, 1))));
5193 return fold (DECL_INITIAL (t
));
5198 case FIX_TRUNC_EXPR
:
5199 /* Other kinds of FIX are not handled properly by fold_convert. */
5201 if (TREE_TYPE (TREE_OPERAND (t
, 0)) == TREE_TYPE (t
))
5202 return TREE_OPERAND (t
, 0);
5204 /* Handle cases of two conversions in a row. */
5205 if (TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
5206 || TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
)
5208 tree inside_type
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5209 tree inter_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
5210 tree final_type
= TREE_TYPE (t
);
5211 int inside_int
= INTEGRAL_TYPE_P (inside_type
);
5212 int inside_ptr
= POINTER_TYPE_P (inside_type
);
5213 int inside_float
= FLOAT_TYPE_P (inside_type
);
5214 unsigned int inside_prec
= TYPE_PRECISION (inside_type
);
5215 int inside_unsignedp
= TREE_UNSIGNED (inside_type
);
5216 int inter_int
= INTEGRAL_TYPE_P (inter_type
);
5217 int inter_ptr
= POINTER_TYPE_P (inter_type
);
5218 int inter_float
= FLOAT_TYPE_P (inter_type
);
5219 unsigned int inter_prec
= TYPE_PRECISION (inter_type
);
5220 int inter_unsignedp
= TREE_UNSIGNED (inter_type
);
5221 int final_int
= INTEGRAL_TYPE_P (final_type
);
5222 int final_ptr
= POINTER_TYPE_P (final_type
);
5223 int final_float
= FLOAT_TYPE_P (final_type
);
5224 unsigned int final_prec
= TYPE_PRECISION (final_type
);
5225 int final_unsignedp
= TREE_UNSIGNED (final_type
);
5227 /* In addition to the cases of two conversions in a row
5228 handled below, if we are converting something to its own
5229 type via an object of identical or wider precision, neither
5230 conversion is needed. */
5231 if (TYPE_MAIN_VARIANT (inside_type
) == TYPE_MAIN_VARIANT (final_type
)
5232 && ((inter_int
&& final_int
) || (inter_float
&& final_float
))
5233 && inter_prec
>= final_prec
)
5234 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5236 /* Likewise, if the intermediate and final types are either both
5237 float or both integer, we don't need the middle conversion if
5238 it is wider than the final type and doesn't change the signedness
5239 (for integers). Avoid this if the final type is a pointer
5240 since then we sometimes need the inner conversion. Likewise if
5241 the outer has a precision not equal to the size of its mode. */
5242 if ((((inter_int
|| inter_ptr
) && (inside_int
|| inside_ptr
))
5243 || (inter_float
&& inside_float
))
5244 && inter_prec
>= inside_prec
5245 && (inter_float
|| inter_unsignedp
== inside_unsignedp
)
5246 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (final_type
))
5247 && TYPE_MODE (final_type
) == TYPE_MODE (inter_type
))
5249 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5251 /* If we have a sign-extension of a zero-extended value, we can
5252 replace that by a single zero-extension. */
5253 if (inside_int
&& inter_int
&& final_int
5254 && inside_prec
< inter_prec
&& inter_prec
< final_prec
5255 && inside_unsignedp
&& !inter_unsignedp
)
5256 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5258 /* Two conversions in a row are not needed unless:
5259 - some conversion is floating-point (overstrict for now), or
5260 - the intermediate type is narrower than both initial and
5262 - the intermediate type and innermost type differ in signedness,
5263 and the outermost type is wider than the intermediate, or
5264 - the initial type is a pointer type and the precisions of the
5265 intermediate and final types differ, or
5266 - the final type is a pointer type and the precisions of the
5267 initial and intermediate types differ. */
5268 if (! inside_float
&& ! inter_float
&& ! final_float
5269 && (inter_prec
> inside_prec
|| inter_prec
> final_prec
)
5270 && ! (inside_int
&& inter_int
5271 && inter_unsignedp
!= inside_unsignedp
5272 && inter_prec
< final_prec
)
5273 && ((inter_unsignedp
&& inter_prec
> inside_prec
)
5274 == (final_unsignedp
&& final_prec
> inter_prec
))
5275 && ! (inside_ptr
&& inter_prec
!= final_prec
)
5276 && ! (final_ptr
&& inside_prec
!= inter_prec
)
5277 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (final_type
))
5278 && TYPE_MODE (final_type
) == TYPE_MODE (inter_type
))
5280 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5283 if (TREE_CODE (TREE_OPERAND (t
, 0)) == MODIFY_EXPR
5284 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t
, 0), 1))
5285 /* Detect assigning a bitfield. */
5286 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0)) == COMPONENT_REF
5287 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t
, 0), 0), 1))))
5289 /* Don't leave an assignment inside a conversion
5290 unless assigning a bitfield. */
5291 tree prev
= TREE_OPERAND (t
, 0);
5292 TREE_OPERAND (t
, 0) = TREE_OPERAND (prev
, 1);
5293 /* First do the assignment, then return converted constant. */
5294 t
= build (COMPOUND_EXPR
, TREE_TYPE (t
), prev
, fold (t
));
5300 TREE_CONSTANT (t
) = TREE_CONSTANT (arg0
);
5303 return fold_convert (t
, arg0
);
5305 case VIEW_CONVERT_EXPR
:
5306 if (TREE_CODE (TREE_OPERAND (t
, 0)) == VIEW_CONVERT_EXPR
)
5307 return build1 (VIEW_CONVERT_EXPR
, type
,
5308 TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5311 #if 0 /* This loses on &"foo"[0]. */
5316 /* Fold an expression like: "foo"[2] */
5317 if (TREE_CODE (arg0
) == STRING_CST
5318 && TREE_CODE (arg1
) == INTEGER_CST
5319 && compare_tree_int (arg1
, TREE_STRING_LENGTH (arg0
)) < 0)
5321 t
= build_int_2 (TREE_STRING_POINTER (arg0
)[TREE_INT_CST_LOW (arg
))], 0);
5322 TREE_TYPE (t
) = TREE_TYPE (TREE_TYPE (arg0
));
5323 force_fit_type (t
, 0);
5330 if (TREE_CODE (arg0
) == CONSTRUCTOR
)
5332 tree m
= purpose_member (arg1
, CONSTRUCTOR_ELTS (arg0
));
5339 TREE_CONSTANT (t
) = wins
;
5345 if (TREE_CODE (arg0
) == INTEGER_CST
)
5347 unsigned HOST_WIDE_INT low
;
5349 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
5350 TREE_INT_CST_HIGH (arg0
),
5352 t
= build_int_2 (low
, high
);
5353 TREE_TYPE (t
) = type
;
5355 = (TREE_OVERFLOW (arg0
)
5356 | force_fit_type (t
, overflow
&& !TREE_UNSIGNED (type
)));
5357 TREE_CONSTANT_OVERFLOW (t
)
5358 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg0
);
5360 else if (TREE_CODE (arg0
) == REAL_CST
)
5361 t
= build_real (type
, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
5363 else if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5364 return TREE_OPERAND (arg0
, 0);
5366 /* Convert - (a - b) to (b - a) for non-floating-point. */
5367 else if (TREE_CODE (arg0
) == MINUS_EXPR
5368 && (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
))
5369 return build (MINUS_EXPR
, type
, TREE_OPERAND (arg0
, 1),
5370 TREE_OPERAND (arg0
, 0));
5377 if (TREE_CODE (arg0
) == INTEGER_CST
)
5379 /* If the value is unsigned, then the absolute value is
5380 the same as the ordinary value. */
5381 if (TREE_UNSIGNED (type
))
5383 /* Similarly, if the value is non-negative. */
5384 else if (INT_CST_LT (integer_minus_one_node
, arg0
))
5386 /* If the value is negative, then the absolute value is
5390 unsigned HOST_WIDE_INT low
;
5392 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
5393 TREE_INT_CST_HIGH (arg0
),
5395 t
= build_int_2 (low
, high
);
5396 TREE_TYPE (t
) = type
;
5398 = (TREE_OVERFLOW (arg0
)
5399 | force_fit_type (t
, overflow
));
5400 TREE_CONSTANT_OVERFLOW (t
)
5401 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg0
);
5404 else if (TREE_CODE (arg0
) == REAL_CST
)
5406 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0
)))
5407 t
= build_real (type
,
5408 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
5411 else if (TREE_CODE (arg0
) == ABS_EXPR
|| TREE_CODE (arg0
) == NEGATE_EXPR
)
5412 return build1 (ABS_EXPR
, type
, TREE_OPERAND (arg0
, 0));
5416 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
5417 return convert (type
, arg0
);
5418 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
5419 return build (COMPLEX_EXPR
, type
,
5420 TREE_OPERAND (arg0
, 0),
5421 negate_expr (TREE_OPERAND (arg0
, 1)));
5422 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
5423 return build_complex (type
, TREE_REALPART (arg0
),
5424 negate_expr (TREE_IMAGPART (arg0
)));
5425 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
5426 return fold (build (TREE_CODE (arg0
), type
,
5427 fold (build1 (CONJ_EXPR
, type
,
5428 TREE_OPERAND (arg0
, 0))),
5429 fold (build1 (CONJ_EXPR
,
5430 type
, TREE_OPERAND (arg0
, 1)))));
5431 else if (TREE_CODE (arg0
) == CONJ_EXPR
)
5432 return TREE_OPERAND (arg0
, 0);
5438 t
= build_int_2 (~ TREE_INT_CST_LOW (arg0
),
5439 ~ TREE_INT_CST_HIGH (arg0
));
5440 TREE_TYPE (t
) = type
;
5441 force_fit_type (t
, 0);
5442 TREE_OVERFLOW (t
) = TREE_OVERFLOW (arg0
);
5443 TREE_CONSTANT_OVERFLOW (t
) = TREE_CONSTANT_OVERFLOW (arg0
);
5445 else if (TREE_CODE (arg0
) == BIT_NOT_EXPR
)
5446 return TREE_OPERAND (arg0
, 0);
5450 /* A + (-B) -> A - B */
5451 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
5452 return fold (build (MINUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
5453 /* (-A) + B -> B - A */
5454 if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5455 return fold (build (MINUS_EXPR
, type
, arg1
, TREE_OPERAND (arg0
, 0)));
5456 else if (! FLOAT_TYPE_P (type
))
5458 if (integer_zerop (arg1
))
5459 return non_lvalue (convert (type
, arg0
));
5461 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5462 with a constant, and the two constants have no bits in common,
5463 we should treat this as a BIT_IOR_EXPR since this may produce more
5465 if (TREE_CODE (arg0
) == BIT_AND_EXPR
5466 && TREE_CODE (arg1
) == BIT_AND_EXPR
5467 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
5468 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
5469 && integer_zerop (const_binop (BIT_AND_EXPR
,
5470 TREE_OPERAND (arg0
, 1),
5471 TREE_OPERAND (arg1
, 1), 0)))
5473 code
= BIT_IOR_EXPR
;
5477 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5478 (plus (plus (mult) (mult)) (foo)) so that we can
5479 take advantage of the factoring cases below. */
5480 if ((TREE_CODE (arg0
) == PLUS_EXPR
5481 && TREE_CODE (arg1
) == MULT_EXPR
)
5482 || (TREE_CODE (arg1
) == PLUS_EXPR
5483 && TREE_CODE (arg0
) == MULT_EXPR
))
5485 tree parg0
, parg1
, parg
, marg
;
5487 if (TREE_CODE (arg0
) == PLUS_EXPR
)
5488 parg
= arg0
, marg
= arg1
;
5490 parg
= arg1
, marg
= arg0
;
5491 parg0
= TREE_OPERAND (parg
, 0);
5492 parg1
= TREE_OPERAND (parg
, 1);
5496 if (TREE_CODE (parg0
) == MULT_EXPR
5497 && TREE_CODE (parg1
) != MULT_EXPR
)
5498 return fold (build (PLUS_EXPR
, type
,
5499 fold (build (PLUS_EXPR
, type
, parg0
, marg
)),
5501 if (TREE_CODE (parg0
) != MULT_EXPR
5502 && TREE_CODE (parg1
) == MULT_EXPR
)
5503 return fold (build (PLUS_EXPR
, type
,
5504 fold (build (PLUS_EXPR
, type
, parg1
, marg
)),
5508 if (TREE_CODE (arg0
) == MULT_EXPR
&& TREE_CODE (arg1
) == MULT_EXPR
)
5510 tree arg00
, arg01
, arg10
, arg11
;
5511 tree alt0
= NULL_TREE
, alt1
= NULL_TREE
, same
;
5513 /* (A * C) + (B * C) -> (A+B) * C.
5514 We are most concerned about the case where C is a constant,
5515 but other combinations show up during loop reduction. Since
5516 it is not difficult, try all four possibilities. */
5518 arg00
= TREE_OPERAND (arg0
, 0);
5519 arg01
= TREE_OPERAND (arg0
, 1);
5520 arg10
= TREE_OPERAND (arg1
, 0);
5521 arg11
= TREE_OPERAND (arg1
, 1);
5524 if (operand_equal_p (arg01
, arg11
, 0))
5525 same
= arg01
, alt0
= arg00
, alt1
= arg10
;
5526 else if (operand_equal_p (arg00
, arg10
, 0))
5527 same
= arg00
, alt0
= arg01
, alt1
= arg11
;
5528 else if (operand_equal_p (arg00
, arg11
, 0))
5529 same
= arg00
, alt0
= arg01
, alt1
= arg10
;
5530 else if (operand_equal_p (arg01
, arg10
, 0))
5531 same
= arg01
, alt0
= arg00
, alt1
= arg11
;
5533 /* No identical multiplicands; see if we can find a common
5534 power-of-two factor in non-power-of-two multiplies. This
5535 can help in multi-dimensional array access. */
5536 else if (TREE_CODE (arg01
) == INTEGER_CST
5537 && TREE_CODE (arg11
) == INTEGER_CST
5538 && TREE_INT_CST_HIGH (arg01
) == 0
5539 && TREE_INT_CST_HIGH (arg11
) == 0)
5541 HOST_WIDE_INT int01
, int11
, tmp
;
5542 int01
= TREE_INT_CST_LOW (arg01
);
5543 int11
= TREE_INT_CST_LOW (arg11
);
5545 /* Move min of absolute values to int11. */
5546 if ((int01
>= 0 ? int01
: -int01
)
5547 < (int11
>= 0 ? int11
: -int11
))
5549 tmp
= int01
, int01
= int11
, int11
= tmp
;
5550 alt0
= arg00
, arg00
= arg10
, arg10
= alt0
;
5551 alt0
= arg01
, arg01
= arg11
, arg11
= alt0
;
5554 if (exact_log2 (int11
) > 0 && int01
% int11
== 0)
5556 alt0
= fold (build (MULT_EXPR
, type
, arg00
,
5557 build_int_2 (int01
/ int11
, 0)));
5564 return fold (build (MULT_EXPR
, type
,
5565 fold (build (PLUS_EXPR
, type
, alt0
, alt1
)),
5569 /* In IEEE floating point, x+0 may not equal x. */
5570 else if ((TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
5571 || flag_unsafe_math_optimizations
)
5572 && real_zerop (arg1
))
5573 return non_lvalue (convert (type
, arg0
));
5574 /* x+(-0) equals x, even for IEEE. */
5575 else if (TREE_CODE (arg1
) == REAL_CST
5576 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1
)))
5577 return non_lvalue (convert (type
, arg0
));
5580 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5581 is a rotate of A by C1 bits. */
5582 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5583 is a rotate of A by B bits. */
5585 enum tree_code code0
, code1
;
5586 code0
= TREE_CODE (arg0
);
5587 code1
= TREE_CODE (arg1
);
5588 if (((code0
== RSHIFT_EXPR
&& code1
== LSHIFT_EXPR
)
5589 || (code1
== RSHIFT_EXPR
&& code0
== LSHIFT_EXPR
))
5590 && operand_equal_p (TREE_OPERAND (arg0
, 0),
5591 TREE_OPERAND (arg1
, 0), 0)
5592 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
5594 tree tree01
, tree11
;
5595 enum tree_code code01
, code11
;
5597 tree01
= TREE_OPERAND (arg0
, 1);
5598 tree11
= TREE_OPERAND (arg1
, 1);
5599 STRIP_NOPS (tree01
);
5600 STRIP_NOPS (tree11
);
5601 code01
= TREE_CODE (tree01
);
5602 code11
= TREE_CODE (tree11
);
5603 if (code01
== INTEGER_CST
5604 && code11
== INTEGER_CST
5605 && TREE_INT_CST_HIGH (tree01
) == 0
5606 && TREE_INT_CST_HIGH (tree11
) == 0
5607 && ((TREE_INT_CST_LOW (tree01
) + TREE_INT_CST_LOW (tree11
))
5608 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)))))
5609 return build (LROTATE_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5610 code0
== LSHIFT_EXPR
? tree01
: tree11
);
5611 else if (code11
== MINUS_EXPR
)
5613 tree tree110
, tree111
;
5614 tree110
= TREE_OPERAND (tree11
, 0);
5615 tree111
= TREE_OPERAND (tree11
, 1);
5616 STRIP_NOPS (tree110
);
5617 STRIP_NOPS (tree111
);
5618 if (TREE_CODE (tree110
) == INTEGER_CST
5619 && 0 == compare_tree_int (tree110
,
5621 (TREE_TYPE (TREE_OPERAND
5623 && operand_equal_p (tree01
, tree111
, 0))
5624 return build ((code0
== LSHIFT_EXPR
5627 type
, TREE_OPERAND (arg0
, 0), tree01
);
5629 else if (code01
== MINUS_EXPR
)
5631 tree tree010
, tree011
;
5632 tree010
= TREE_OPERAND (tree01
, 0);
5633 tree011
= TREE_OPERAND (tree01
, 1);
5634 STRIP_NOPS (tree010
);
5635 STRIP_NOPS (tree011
);
5636 if (TREE_CODE (tree010
) == INTEGER_CST
5637 && 0 == compare_tree_int (tree010
,
5639 (TREE_TYPE (TREE_OPERAND
5641 && operand_equal_p (tree11
, tree011
, 0))
5642 return build ((code0
!= LSHIFT_EXPR
5645 type
, TREE_OPERAND (arg0
, 0), tree11
);
5651 /* In most languages, can't associate operations on floats through
5652 parentheses. Rather than remember where the parentheses were, we
5653 don't associate floats at all. It shouldn't matter much. However,
5654 associating multiplications is only very slightly inaccurate, so do
5655 that if -funsafe-math-optimizations is specified. */
5658 && (! FLOAT_TYPE_P (type
)
5659 || (flag_unsafe_math_optimizations
&& code
== MULT_EXPR
)))
5661 tree var0
, con0
, lit0
, var1
, con1
, lit1
;
5663 /* Split both trees into variables, constants, and literals. Then
5664 associate each group together, the constants with literals,
5665 then the result with variables. This increases the chances of
5666 literals being recombined later and of generating relocatable
5667 expressions for the sum of a constant and literal. */
5668 var0
= split_tree (arg0
, code
, &con0
, &lit0
, 0);
5669 var1
= split_tree (arg1
, code
, &con1
, &lit1
, code
== MINUS_EXPR
);
5671 /* Only do something if we found more than two objects. Otherwise,
5672 nothing has changed and we risk infinite recursion. */
5673 if (2 < ((var0
!= 0) + (var1
!= 0) + (con0
!= 0) + (con1
!= 0)
5674 + (lit0
!= 0) + (lit1
!= 0)))
5676 var0
= associate_trees (var0
, var1
, code
, type
);
5677 con0
= associate_trees (con0
, con1
, code
, type
);
5678 lit0
= associate_trees (lit0
, lit1
, code
, type
);
5679 con0
= associate_trees (con0
, lit0
, code
, type
);
5680 return convert (type
, associate_trees (var0
, con0
, code
, type
));
5685 #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
5686 if (TREE_CODE (arg1
) == REAL_CST
)
5688 #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
5690 t1
= const_binop (code
, arg0
, arg1
, 0);
5691 if (t1
!= NULL_TREE
)
5693 /* The return value should always have
5694 the same type as the original expression. */
5695 if (TREE_TYPE (t1
) != TREE_TYPE (t
))
5696 t1
= convert (TREE_TYPE (t
), t1
);
5703 /* A - (-B) -> A + B */
5704 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
5705 return fold (build (PLUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
5706 /* (-A) - CST -> (-CST) - A for floating point (what about ints ?) */
5707 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == REAL_CST
)
5709 fold (build (MINUS_EXPR
, type
,
5710 build_real (TREE_TYPE (arg1
),
5711 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1
))),
5712 TREE_OPERAND (arg0
, 0)));
5714 if (! FLOAT_TYPE_P (type
))
5716 if (! wins
&& integer_zerop (arg0
))
5717 return negate_expr (convert (type
, arg1
));
5718 if (integer_zerop (arg1
))
5719 return non_lvalue (convert (type
, arg0
));
5721 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5722 about the case where C is a constant, just try one of the
5723 four possibilities. */
5725 if (TREE_CODE (arg0
) == MULT_EXPR
&& TREE_CODE (arg1
) == MULT_EXPR
5726 && operand_equal_p (TREE_OPERAND (arg0
, 1),
5727 TREE_OPERAND (arg1
, 1), 0))
5728 return fold (build (MULT_EXPR
, type
,
5729 fold (build (MINUS_EXPR
, type
,
5730 TREE_OPERAND (arg0
, 0),
5731 TREE_OPERAND (arg1
, 0))),
5732 TREE_OPERAND (arg0
, 1)));
5735 else if (TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
5736 || flag_unsafe_math_optimizations
)
5738 /* Except with IEEE floating point, 0-x equals -x. */
5739 if (! wins
&& real_zerop (arg0
))
5740 return negate_expr (convert (type
, arg1
));
5741 /* Except with IEEE floating point, x-0 equals x. */
5742 if (real_zerop (arg1
))
5743 return non_lvalue (convert (type
, arg0
));
5746 /* Fold &x - &x. This can happen from &x.foo - &x.
5747 This is unsafe for certain floats even in non-IEEE formats.
5748 In IEEE, it is unsafe because it does wrong for NaNs.
5749 Also note that operand_equal_p is always false if an operand
5752 if ((! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
5753 && operand_equal_p (arg0
, arg1
, 0))
5754 return convert (type
, integer_zero_node
);
5759 /* (-A) * (-B) -> A * B */
5760 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == NEGATE_EXPR
)
5761 return fold (build (MULT_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5762 TREE_OPERAND (arg1
, 0)));
5764 if (! FLOAT_TYPE_P (type
))
5766 if (integer_zerop (arg1
))
5767 return omit_one_operand (type
, arg1
, arg0
);
5768 if (integer_onep (arg1
))
5769 return non_lvalue (convert (type
, arg0
));
5771 /* (a * (1 << b)) is (a << b) */
5772 if (TREE_CODE (arg1
) == LSHIFT_EXPR
5773 && integer_onep (TREE_OPERAND (arg1
, 0)))
5774 return fold (build (LSHIFT_EXPR
, type
, arg0
,
5775 TREE_OPERAND (arg1
, 1)));
5776 if (TREE_CODE (arg0
) == LSHIFT_EXPR
5777 && integer_onep (TREE_OPERAND (arg0
, 0)))
5778 return fold (build (LSHIFT_EXPR
, type
, arg1
,
5779 TREE_OPERAND (arg0
, 1)));
5781 if (TREE_CODE (arg1
) == INTEGER_CST
5782 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
5784 return convert (type
, tem
);
5789 /* x*0 is 0, except for IEEE floating point. */
5790 if ((TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
5791 || flag_unsafe_math_optimizations
)
5792 && real_zerop (arg1
))
5793 return omit_one_operand (type
, arg1
, arg0
);
5794 /* In IEEE floating point, x*1 is not equivalent to x for snans.
5795 However, ANSI says we can drop signals,
5796 so we can do this anyway. */
5797 if (real_onep (arg1
))
5798 return non_lvalue (convert (type
, arg0
));
5800 if (! wins
&& real_twop (arg1
) && global_bindings_p () == 0
5801 && ! contains_placeholder_p (arg0
))
5803 tree arg
= save_expr (arg0
);
5804 return build (PLUS_EXPR
, type
, arg
, arg
);
5811 if (integer_all_onesp (arg1
))
5812 return omit_one_operand (type
, arg1
, arg0
);
5813 if (integer_zerop (arg1
))
5814 return non_lvalue (convert (type
, arg0
));
5815 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
5816 if (t1
!= NULL_TREE
)
5819 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
5821 This results in more efficient code for machines without a NAND
5822 instruction. Combine will canonicalize to the first form
5823 which will allow use of NAND instructions provided by the
5824 backend if they exist. */
5825 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
5826 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
5828 return fold (build1 (BIT_NOT_EXPR
, type
,
5829 build (BIT_AND_EXPR
, type
,
5830 TREE_OPERAND (arg0
, 0),
5831 TREE_OPERAND (arg1
, 0))));
5834 /* See if this can be simplified into a rotate first. If that
5835 is unsuccessful continue in the association code. */
5839 if (integer_zerop (arg1
))
5840 return non_lvalue (convert (type
, arg0
));
5841 if (integer_all_onesp (arg1
))
5842 return fold (build1 (BIT_NOT_EXPR
, type
, arg0
));
5844 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
5845 with a constant, and the two constants have no bits in common,
5846 we should treat this as a BIT_IOR_EXPR since this may produce more
5848 if (TREE_CODE (arg0
) == BIT_AND_EXPR
5849 && TREE_CODE (arg1
) == BIT_AND_EXPR
5850 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
5851 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
5852 && integer_zerop (const_binop (BIT_AND_EXPR
,
5853 TREE_OPERAND (arg0
, 1),
5854 TREE_OPERAND (arg1
, 1), 0)))
5856 code
= BIT_IOR_EXPR
;
5860 /* See if this can be simplified into a rotate first. If that
5861 is unsuccessful continue in the association code. */
5866 if (integer_all_onesp (arg1
))
5867 return non_lvalue (convert (type
, arg0
));
5868 if (integer_zerop (arg1
))
5869 return omit_one_operand (type
, arg1
, arg0
);
5870 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
5871 if (t1
!= NULL_TREE
)
5873 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5874 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == NOP_EXPR
5875 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1
, 0))))
5878 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1
, 0)));
5880 if (prec
< BITS_PER_WORD
&& prec
< HOST_BITS_PER_WIDE_INT
5881 && (~TREE_INT_CST_LOW (arg0
)
5882 & (((HOST_WIDE_INT
) 1 << prec
) - 1)) == 0)
5883 return build1 (NOP_EXPR
, type
, TREE_OPERAND (arg1
, 0));
5885 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) == NOP_EXPR
5886 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
5889 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)));
5891 if (prec
< BITS_PER_WORD
&& prec
< HOST_BITS_PER_WIDE_INT
5892 && (~TREE_INT_CST_LOW (arg1
)
5893 & (((HOST_WIDE_INT
) 1 << prec
) - 1)) == 0)
5894 return build1 (NOP_EXPR
, type
, TREE_OPERAND (arg0
, 0));
5897 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
5899 This results in more efficient code for machines without a NOR
5900 instruction. Combine will canonicalize to the first form
5901 which will allow use of NOR instructions provided by the
5902 backend if they exist. */
5903 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
5904 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
5906 return fold (build1 (BIT_NOT_EXPR
, type
,
5907 build (BIT_IOR_EXPR
, type
,
5908 TREE_OPERAND (arg0
, 0),
5909 TREE_OPERAND (arg1
, 0))));
5914 case BIT_ANDTC_EXPR
:
5915 if (integer_all_onesp (arg0
))
5916 return non_lvalue (convert (type
, arg1
));
5917 if (integer_zerop (arg0
))
5918 return omit_one_operand (type
, arg0
, arg1
);
5919 if (TREE_CODE (arg1
) == INTEGER_CST
)
5921 arg1
= fold (build1 (BIT_NOT_EXPR
, type
, arg1
));
5922 code
= BIT_AND_EXPR
;
5928 /* In most cases, do nothing with a divide by zero. */
5929 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5930 #ifndef REAL_INFINITY
5931 if (TREE_CODE (arg1
) == REAL_CST
&& real_zerop (arg1
))
5934 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5936 /* (-A) / (-B) -> A / B */
5937 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == NEGATE_EXPR
)
5938 return fold (build (RDIV_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5939 TREE_OPERAND (arg1
, 0)));
5941 /* In IEEE floating point, x/1 is not equivalent to x for snans.
5942 However, ANSI says we can drop signals, so we can do this anyway. */
5943 if (real_onep (arg1
))
5944 return non_lvalue (convert (type
, arg0
));
5946 /* If ARG1 is a constant, we can convert this to a multiply by the
5947 reciprocal. This does not have the same rounding properties,
5948 so only do this if -funsafe-math-optimizations. We can actually
5949 always safely do it if ARG1 is a power of two, but it's hard to
5950 tell if it is or not in a portable manner. */
5951 if (TREE_CODE (arg1
) == REAL_CST
)
5953 if (flag_unsafe_math_optimizations
5954 && 0 != (tem
= const_binop (code
, build_real (type
, dconst1
),
5956 return fold (build (MULT_EXPR
, type
, arg0
, tem
));
5957 /* Find the reciprocal if optimizing and the result is exact. */
5961 r
= TREE_REAL_CST (arg1
);
5962 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0
)), &r
))
5964 tem
= build_real (type
, r
);
5965 return fold (build (MULT_EXPR
, type
, arg0
, tem
));
5969 /* Convert A/B/C to A/(B*C). */
5970 if (flag_unsafe_math_optimizations
5971 && TREE_CODE (arg0
) == RDIV_EXPR
)
5973 return fold (build (RDIV_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5974 build (MULT_EXPR
, type
, TREE_OPERAND (arg0
, 1),
5977 /* Convert A/(B/C) to (A/B)*C. */
5978 if (flag_unsafe_math_optimizations
5979 && TREE_CODE (arg1
) == RDIV_EXPR
)
5981 return fold (build (MULT_EXPR
, type
,
5982 build (RDIV_EXPR
, type
, arg0
,
5983 TREE_OPERAND (arg1
, 0)),
5984 TREE_OPERAND (arg1
, 1)));
5988 case TRUNC_DIV_EXPR
:
5989 case ROUND_DIV_EXPR
:
5990 case FLOOR_DIV_EXPR
:
5992 case EXACT_DIV_EXPR
:
5993 if (integer_onep (arg1
))
5994 return non_lvalue (convert (type
, arg0
));
5995 if (integer_zerop (arg1
))
5998 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
5999 operation, EXACT_DIV_EXPR.
6001 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
6002 At one time others generated faster code, it's not clear if they do
6003 after the last round to changes to the DIV code in expmed.c. */
6004 if ((code
== CEIL_DIV_EXPR
|| code
== FLOOR_DIV_EXPR
)
6005 && multiple_of_p (type
, arg0
, arg1
))
6006 return fold (build (EXACT_DIV_EXPR
, type
, arg0
, arg1
));
6008 if (TREE_CODE (arg1
) == INTEGER_CST
6009 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
6011 return convert (type
, tem
);
6016 case FLOOR_MOD_EXPR
:
6017 case ROUND_MOD_EXPR
:
6018 case TRUNC_MOD_EXPR
:
6019 if (integer_onep (arg1
))
6020 return omit_one_operand (type
, integer_zero_node
, arg0
);
6021 if (integer_zerop (arg1
))
6024 if (TREE_CODE (arg1
) == INTEGER_CST
6025 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
6027 return convert (type
, tem
);
6035 if (integer_zerop (arg1
))
6036 return non_lvalue (convert (type
, arg0
));
6037 /* Since negative shift count is not well-defined,
6038 don't try to compute it in the compiler. */
6039 if (TREE_CODE (arg1
) == INTEGER_CST
&& tree_int_cst_sgn (arg1
) < 0)
6041 /* Rewrite an LROTATE_EXPR by a constant into an
6042 RROTATE_EXPR by a new constant. */
6043 if (code
== LROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
)
6045 TREE_SET_CODE (t
, RROTATE_EXPR
);
6046 code
= RROTATE_EXPR
;
6047 TREE_OPERAND (t
, 1) = arg1
6050 convert (TREE_TYPE (arg1
),
6051 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type
)), 0)),
6053 if (tree_int_cst_sgn (arg1
) < 0)
6057 /* If we have a rotate of a bit operation with the rotate count and
6058 the second operand of the bit operation both constant,
6059 permute the two operations. */
6060 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
6061 && (TREE_CODE (arg0
) == BIT_AND_EXPR
6062 || TREE_CODE (arg0
) == BIT_ANDTC_EXPR
6063 || TREE_CODE (arg0
) == BIT_IOR_EXPR
6064 || TREE_CODE (arg0
) == BIT_XOR_EXPR
)
6065 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
6066 return fold (build (TREE_CODE (arg0
), type
,
6067 fold (build (code
, type
,
6068 TREE_OPERAND (arg0
, 0), arg1
)),
6069 fold (build (code
, type
,
6070 TREE_OPERAND (arg0
, 1), arg1
))));
6072 /* Two consecutive rotates adding up to the width of the mode can
6074 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
6075 && TREE_CODE (arg0
) == RROTATE_EXPR
6076 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
6077 && TREE_INT_CST_HIGH (arg1
) == 0
6078 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0
, 1)) == 0
6079 && ((TREE_INT_CST_LOW (arg1
)
6080 + TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1)))
6081 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type
))))
6082 return TREE_OPERAND (arg0
, 0);
6087 if (operand_equal_p (arg0
, arg1
, 0))
6088 return omit_one_operand (type
, arg0
, arg1
);
6089 if (INTEGRAL_TYPE_P (type
)
6090 && operand_equal_p (arg1
, TYPE_MIN_VALUE (type
), 1))
6091 return omit_one_operand (type
, arg1
, arg0
);
6095 if (operand_equal_p (arg0
, arg1
, 0))
6096 return omit_one_operand (type
, arg0
, arg1
);
6097 if (INTEGRAL_TYPE_P (type
)
6098 && TYPE_MAX_VALUE (type
)
6099 && operand_equal_p (arg1
, TYPE_MAX_VALUE (type
), 1))
6100 return omit_one_operand (type
, arg1
, arg0
);
6103 case TRUTH_NOT_EXPR
:
6104 /* Note that the operand of this must be an int
6105 and its values must be 0 or 1.
6106 ("true" is a fixed value perhaps depending on the language,
6107 but we don't handle values other than 1 correctly yet.) */
6108 tem
= invert_truthvalue (arg0
);
6109 /* Avoid infinite recursion. */
6110 if (TREE_CODE (tem
) == TRUTH_NOT_EXPR
)
6112 return convert (type
, tem
);
6114 case TRUTH_ANDIF_EXPR
:
6115 /* Note that the operands of this must be ints
6116 and their values must be 0 or 1.
6117 ("true" is a fixed value perhaps depending on the language.) */
6118 /* If first arg is constant zero, return it. */
6119 if (integer_zerop (arg0
))
6120 return convert (type
, arg0
);
6121 case TRUTH_AND_EXPR
:
6122 /* If either arg is constant true, drop it. */
6123 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6124 return non_lvalue (convert (type
, arg1
));
6125 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
)
6126 /* Preserve sequence points. */
6127 && (code
!= TRUTH_ANDIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
6128 return non_lvalue (convert (type
, arg0
));
6129 /* If second arg is constant zero, result is zero, but first arg
6130 must be evaluated. */
6131 if (integer_zerop (arg1
))
6132 return omit_one_operand (type
, arg1
, arg0
);
6133 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
6134 case will be handled here. */
6135 if (integer_zerop (arg0
))
6136 return omit_one_operand (type
, arg0
, arg1
);
6139 /* We only do these simplifications if we are optimizing. */
6143 /* Check for things like (A || B) && (A || C). We can convert this
6144 to A || (B && C). Note that either operator can be any of the four
6145 truth and/or operations and the transformation will still be
6146 valid. Also note that we only care about order for the
6147 ANDIF and ORIF operators. If B contains side effects, this
6148 might change the truth-value of A. */
6149 if (TREE_CODE (arg0
) == TREE_CODE (arg1
)
6150 && (TREE_CODE (arg0
) == TRUTH_ANDIF_EXPR
6151 || TREE_CODE (arg0
) == TRUTH_ORIF_EXPR
6152 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
6153 || TREE_CODE (arg0
) == TRUTH_OR_EXPR
)
6154 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0
, 1)))
6156 tree a00
= TREE_OPERAND (arg0
, 0);
6157 tree a01
= TREE_OPERAND (arg0
, 1);
6158 tree a10
= TREE_OPERAND (arg1
, 0);
6159 tree a11
= TREE_OPERAND (arg1
, 1);
6160 int commutative
= ((TREE_CODE (arg0
) == TRUTH_OR_EXPR
6161 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
)
6162 && (code
== TRUTH_AND_EXPR
6163 || code
== TRUTH_OR_EXPR
));
6165 if (operand_equal_p (a00
, a10
, 0))
6166 return fold (build (TREE_CODE (arg0
), type
, a00
,
6167 fold (build (code
, type
, a01
, a11
))));
6168 else if (commutative
&& operand_equal_p (a00
, a11
, 0))
6169 return fold (build (TREE_CODE (arg0
), type
, a00
,
6170 fold (build (code
, type
, a01
, a10
))));
6171 else if (commutative
&& operand_equal_p (a01
, a10
, 0))
6172 return fold (build (TREE_CODE (arg0
), type
, a01
,
6173 fold (build (code
, type
, a00
, a11
))));
6175 /* This case if tricky because we must either have commutative
6176 operators or else A10 must not have side-effects. */
6178 else if ((commutative
|| ! TREE_SIDE_EFFECTS (a10
))
6179 && operand_equal_p (a01
, a11
, 0))
6180 return fold (build (TREE_CODE (arg0
), type
,
6181 fold (build (code
, type
, a00
, a10
)),
6185 /* See if we can build a range comparison. */
6186 if (0 != (tem
= fold_range_test (t
)))
6189 /* Check for the possibility of merging component references. If our
6190 lhs is another similar operation, try to merge its rhs with our
6191 rhs. Then try to merge our lhs and rhs. */
6192 if (TREE_CODE (arg0
) == code
6193 && 0 != (tem
= fold_truthop (code
, type
,
6194 TREE_OPERAND (arg0
, 1), arg1
)))
6195 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6197 if ((tem
= fold_truthop (code
, type
, arg0
, arg1
)) != 0)
6202 case TRUTH_ORIF_EXPR
:
6203 /* Note that the operands of this must be ints
6204 and their values must be 0 or true.
6205 ("true" is a fixed value perhaps depending on the language.) */
6206 /* If first arg is constant true, return it. */
6207 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6208 return convert (type
, arg0
);
6210 /* If either arg is constant zero, drop it. */
6211 if (TREE_CODE (arg0
) == INTEGER_CST
&& integer_zerop (arg0
))
6212 return non_lvalue (convert (type
, arg1
));
6213 if (TREE_CODE (arg1
) == INTEGER_CST
&& integer_zerop (arg1
)
6214 /* Preserve sequence points. */
6215 && (code
!= TRUTH_ORIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
6216 return non_lvalue (convert (type
, arg0
));
6217 /* If second arg is constant true, result is true, but we must
6218 evaluate first arg. */
6219 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
))
6220 return omit_one_operand (type
, arg1
, arg0
);
6221 /* Likewise for first arg, but note this only occurs here for
6223 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6224 return omit_one_operand (type
, arg0
, arg1
);
6227 case TRUTH_XOR_EXPR
:
6228 /* If either arg is constant zero, drop it. */
6229 if (integer_zerop (arg0
))
6230 return non_lvalue (convert (type
, arg1
));
6231 if (integer_zerop (arg1
))
6232 return non_lvalue (convert (type
, arg0
));
6233 /* If either arg is constant true, this is a logical inversion. */
6234 if (integer_onep (arg0
))
6235 return non_lvalue (convert (type
, invert_truthvalue (arg1
)));
6236 if (integer_onep (arg1
))
6237 return non_lvalue (convert (type
, invert_truthvalue (arg0
)));
6246 if (FLOAT_TYPE_P (TREE_TYPE (arg0
)))
6248 /* (-a) CMP (-b) -> b CMP a */
6249 if (TREE_CODE (arg0
) == NEGATE_EXPR
6250 && TREE_CODE (arg1
) == NEGATE_EXPR
)
6251 return fold (build (code
, type
, TREE_OPERAND (arg1
, 0),
6252 TREE_OPERAND (arg0
, 0)));
6253 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6254 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == REAL_CST
)
6257 (swap_tree_comparison (code
), type
,
6258 TREE_OPERAND (arg0
, 0),
6259 build_real (TREE_TYPE (arg1
),
6260 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1
)))));
6261 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6262 /* a CMP (-0) -> a CMP 0 */
6263 if (TREE_CODE (arg1
) == REAL_CST
6264 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1
)))
6265 return fold (build (code
, type
, arg0
,
6266 build_real (TREE_TYPE (arg1
), dconst0
)));
6269 /* If one arg is a constant integer, put it last. */
6270 if (TREE_CODE (arg0
) == INTEGER_CST
6271 && TREE_CODE (arg1
) != INTEGER_CST
)
6273 TREE_OPERAND (t
, 0) = arg1
;
6274 TREE_OPERAND (t
, 1) = arg0
;
6275 arg0
= TREE_OPERAND (t
, 0);
6276 arg1
= TREE_OPERAND (t
, 1);
6277 code
= swap_tree_comparison (code
);
6278 TREE_SET_CODE (t
, code
);
6281 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6282 First, see if one arg is constant; find the constant arg
6283 and the other one. */
6285 tree constop
= 0, varop
= NULL_TREE
;
6286 int constopnum
= -1;
6288 if (TREE_CONSTANT (arg1
))
6289 constopnum
= 1, constop
= arg1
, varop
= arg0
;
6290 if (TREE_CONSTANT (arg0
))
6291 constopnum
= 0, constop
= arg0
, varop
= arg1
;
6293 if (constop
&& TREE_CODE (varop
) == POSTINCREMENT_EXPR
)
6295 /* This optimization is invalid for ordered comparisons
6296 if CONST+INCR overflows or if foo+incr might overflow.
6297 This optimization is invalid for floating point due to rounding.
6298 For pointer types we assume overflow doesn't happen. */
6299 if (POINTER_TYPE_P (TREE_TYPE (varop
))
6300 || (! FLOAT_TYPE_P (TREE_TYPE (varop
))
6301 && (code
== EQ_EXPR
|| code
== NE_EXPR
)))
6304 = fold (build (PLUS_EXPR
, TREE_TYPE (varop
),
6305 constop
, TREE_OPERAND (varop
, 1)));
6307 /* Do not overwrite the current varop to be a preincrement,
6308 create a new node so that we won't confuse our caller who
6309 might create trees and throw them away, reusing the
6310 arguments that they passed to build. This shows up in
6311 the THEN or ELSE parts of ?: being postincrements. */
6312 varop
= build (PREINCREMENT_EXPR
, TREE_TYPE (varop
),
6313 TREE_OPERAND (varop
, 0),
6314 TREE_OPERAND (varop
, 1));
6316 /* If VAROP is a reference to a bitfield, we must mask
6317 the constant by the width of the field. */
6318 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
6319 && DECL_BIT_FIELD(TREE_OPERAND
6320 (TREE_OPERAND (varop
, 0), 1)))
6323 = TREE_INT_CST_LOW (DECL_SIZE
6325 (TREE_OPERAND (varop
, 0), 1)));
6326 tree mask
, unsigned_type
;
6327 unsigned int precision
;
6328 tree folded_compare
;
6330 /* First check whether the comparison would come out
6331 always the same. If we don't do that we would
6332 change the meaning with the masking. */
6333 if (constopnum
== 0)
6334 folded_compare
= fold (build (code
, type
, constop
,
6335 TREE_OPERAND (varop
, 0)));
6337 folded_compare
= fold (build (code
, type
,
6338 TREE_OPERAND (varop
, 0),
6340 if (integer_zerop (folded_compare
)
6341 || integer_onep (folded_compare
))
6342 return omit_one_operand (type
, folded_compare
, varop
);
6344 unsigned_type
= type_for_size (size
, 1);
6345 precision
= TYPE_PRECISION (unsigned_type
);
6346 mask
= build_int_2 (~0, ~0);
6347 TREE_TYPE (mask
) = unsigned_type
;
6348 force_fit_type (mask
, 0);
6349 mask
= const_binop (RSHIFT_EXPR
, mask
,
6350 size_int (precision
- size
), 0);
6351 newconst
= fold (build (BIT_AND_EXPR
,
6352 TREE_TYPE (varop
), newconst
,
6353 convert (TREE_TYPE (varop
),
6357 t
= build (code
, type
,
6358 (constopnum
== 0) ? newconst
: varop
,
6359 (constopnum
== 1) ? newconst
: varop
);
6363 else if (constop
&& TREE_CODE (varop
) == POSTDECREMENT_EXPR
)
6365 if (POINTER_TYPE_P (TREE_TYPE (varop
))
6366 || (! FLOAT_TYPE_P (TREE_TYPE (varop
))
6367 && (code
== EQ_EXPR
|| code
== NE_EXPR
)))
6370 = fold (build (MINUS_EXPR
, TREE_TYPE (varop
),
6371 constop
, TREE_OPERAND (varop
, 1)));
6373 /* Do not overwrite the current varop to be a predecrement,
6374 create a new node so that we won't confuse our caller who
6375 might create trees and throw them away, reusing the
6376 arguments that they passed to build. This shows up in
6377 the THEN or ELSE parts of ?: being postdecrements. */
6378 varop
= build (PREDECREMENT_EXPR
, TREE_TYPE (varop
),
6379 TREE_OPERAND (varop
, 0),
6380 TREE_OPERAND (varop
, 1));
6382 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
6383 && DECL_BIT_FIELD(TREE_OPERAND
6384 (TREE_OPERAND (varop
, 0), 1)))
6387 = TREE_INT_CST_LOW (DECL_SIZE
6389 (TREE_OPERAND (varop
, 0), 1)));
6390 tree mask
, unsigned_type
;
6391 unsigned int precision
;
6392 tree folded_compare
;
6394 if (constopnum
== 0)
6395 folded_compare
= fold (build (code
, type
, constop
,
6396 TREE_OPERAND (varop
, 0)));
6398 folded_compare
= fold (build (code
, type
,
6399 TREE_OPERAND (varop
, 0),
6401 if (integer_zerop (folded_compare
)
6402 || integer_onep (folded_compare
))
6403 return omit_one_operand (type
, folded_compare
, varop
);
6405 unsigned_type
= type_for_size (size
, 1);
6406 precision
= TYPE_PRECISION (unsigned_type
);
6407 mask
= build_int_2 (~0, ~0);
6408 TREE_TYPE (mask
) = TREE_TYPE (varop
);
6409 force_fit_type (mask
, 0);
6410 mask
= const_binop (RSHIFT_EXPR
, mask
,
6411 size_int (precision
- size
), 0);
6412 newconst
= fold (build (BIT_AND_EXPR
,
6413 TREE_TYPE (varop
), newconst
,
6414 convert (TREE_TYPE (varop
),
6418 t
= build (code
, type
,
6419 (constopnum
== 0) ? newconst
: varop
,
6420 (constopnum
== 1) ? newconst
: varop
);
6426 /* Change X >= CST to X > (CST - 1) if CST is positive. */
6427 if (TREE_CODE (arg1
) == INTEGER_CST
6428 && TREE_CODE (arg0
) != INTEGER_CST
6429 && tree_int_cst_sgn (arg1
) > 0)
6431 switch (TREE_CODE (t
))
6435 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6436 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6441 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6442 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6450 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6451 a MINUS_EXPR of a constant, we can convert it into a comparison with
6452 a revised constant as long as no overflow occurs. */
6453 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6454 && TREE_CODE (arg1
) == INTEGER_CST
6455 && (TREE_CODE (arg0
) == PLUS_EXPR
6456 || TREE_CODE (arg0
) == MINUS_EXPR
)
6457 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
6458 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
6459 ? MINUS_EXPR
: PLUS_EXPR
,
6460 arg1
, TREE_OPERAND (arg0
, 1), 0))
6461 && ! TREE_CONSTANT_OVERFLOW (tem
))
6462 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6464 /* Similarly for a NEGATE_EXPR. */
6465 else if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6466 && TREE_CODE (arg0
) == NEGATE_EXPR
6467 && TREE_CODE (arg1
) == INTEGER_CST
6468 && 0 != (tem
= negate_expr (arg1
))
6469 && TREE_CODE (tem
) == INTEGER_CST
6470 && ! TREE_CONSTANT_OVERFLOW (tem
))
6471 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6473 /* If we have X - Y == 0, we can convert that to X == Y and similarly
6474 for !=. Don't do this for ordered comparisons due to overflow. */
6475 else if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
6476 && integer_zerop (arg1
) && TREE_CODE (arg0
) == MINUS_EXPR
)
6477 return fold (build (code
, type
,
6478 TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg0
, 1)));
6480 /* If we are widening one operand of an integer comparison,
6481 see if the other operand is similarly being widened. Perhaps we
6482 can do the comparison in the narrower type. */
6483 else if (TREE_CODE (TREE_TYPE (arg0
)) == INTEGER_TYPE
6484 && TREE_CODE (arg0
) == NOP_EXPR
6485 && (tem
= get_unwidened (arg0
, NULL_TREE
)) != arg0
6486 && (t1
= get_unwidened (arg1
, TREE_TYPE (tem
))) != 0
6487 && (TREE_TYPE (t1
) == TREE_TYPE (tem
)
6488 || (TREE_CODE (t1
) == INTEGER_CST
6489 && int_fits_type_p (t1
, TREE_TYPE (tem
)))))
6490 return fold (build (code
, type
, tem
, convert (TREE_TYPE (tem
), t1
)));
6492 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
6493 constant, we can simplify it. */
6494 else if (TREE_CODE (arg1
) == INTEGER_CST
6495 && (TREE_CODE (arg0
) == MIN_EXPR
6496 || TREE_CODE (arg0
) == MAX_EXPR
)
6497 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
6498 return optimize_minmax_comparison (t
);
6500 /* If we are comparing an ABS_EXPR with a constant, we can
6501 convert all the cases into explicit comparisons, but they may
6502 well not be faster than doing the ABS and one comparison.
6503 But ABS (X) <= C is a range comparison, which becomes a subtraction
6504 and a comparison, and is probably faster. */
6505 else if (code
== LE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
6506 && TREE_CODE (arg0
) == ABS_EXPR
6507 && ! TREE_SIDE_EFFECTS (arg0
)
6508 && (0 != (tem
= negate_expr (arg1
)))
6509 && TREE_CODE (tem
) == INTEGER_CST
6510 && ! TREE_CONSTANT_OVERFLOW (tem
))
6511 return fold (build (TRUTH_ANDIF_EXPR
, type
,
6512 build (GE_EXPR
, type
, TREE_OPERAND (arg0
, 0), tem
),
6513 build (LE_EXPR
, type
,
6514 TREE_OPERAND (arg0
, 0), arg1
)));
6516 /* If this is an EQ or NE comparison with zero and ARG0 is
6517 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
6518 two operations, but the latter can be done in one less insn
6519 on machines that have only two-operand insns or on which a
6520 constant cannot be the first operand. */
6521 if (integer_zerop (arg1
) && (code
== EQ_EXPR
|| code
== NE_EXPR
)
6522 && TREE_CODE (arg0
) == BIT_AND_EXPR
)
6524 if (TREE_CODE (TREE_OPERAND (arg0
, 0)) == LSHIFT_EXPR
6525 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0)))
6527 fold (build (code
, type
,
6528 build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
6530 TREE_TYPE (TREE_OPERAND (arg0
, 0)),
6531 TREE_OPERAND (arg0
, 1),
6532 TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1)),
6533 convert (TREE_TYPE (arg0
),
6536 else if (TREE_CODE (TREE_OPERAND (arg0
, 1)) == LSHIFT_EXPR
6537 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 1), 0)))
6539 fold (build (code
, type
,
6540 build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
6542 TREE_TYPE (TREE_OPERAND (arg0
, 1)),
6543 TREE_OPERAND (arg0
, 0),
6544 TREE_OPERAND (TREE_OPERAND (arg0
, 1), 1)),
6545 convert (TREE_TYPE (arg0
),
6550 /* If this is an NE or EQ comparison of zero against the result of a
6551 signed MOD operation whose second operand is a power of 2, make
6552 the MOD operation unsigned since it is simpler and equivalent. */
6553 if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
6554 && integer_zerop (arg1
)
6555 && ! TREE_UNSIGNED (TREE_TYPE (arg0
))
6556 && (TREE_CODE (arg0
) == TRUNC_MOD_EXPR
6557 || TREE_CODE (arg0
) == CEIL_MOD_EXPR
6558 || TREE_CODE (arg0
) == FLOOR_MOD_EXPR
6559 || TREE_CODE (arg0
) == ROUND_MOD_EXPR
)
6560 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
6562 tree newtype
= unsigned_type (TREE_TYPE (arg0
));
6563 tree newmod
= build (TREE_CODE (arg0
), newtype
,
6564 convert (newtype
, TREE_OPERAND (arg0
, 0)),
6565 convert (newtype
, TREE_OPERAND (arg0
, 1)));
6567 return build (code
, type
, newmod
, convert (newtype
, arg1
));
6570 /* If this is an NE comparison of zero with an AND of one, remove the
6571 comparison since the AND will give the correct value. */
6572 if (code
== NE_EXPR
&& integer_zerop (arg1
)
6573 && TREE_CODE (arg0
) == BIT_AND_EXPR
6574 && integer_onep (TREE_OPERAND (arg0
, 1)))
6575 return convert (type
, arg0
);
6577 /* If we have (A & C) == C where C is a power of 2, convert this into
6578 (A & C) != 0. Similarly for NE_EXPR. */
6579 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6580 && TREE_CODE (arg0
) == BIT_AND_EXPR
6581 && integer_pow2p (TREE_OPERAND (arg0
, 1))
6582 && operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
6583 return build (code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
, type
,
6584 arg0
, integer_zero_node
);
6586 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
6587 and similarly for >= into !=. */
6588 if ((code
== LT_EXPR
|| code
== GE_EXPR
)
6589 && TREE_UNSIGNED (TREE_TYPE (arg0
))
6590 && TREE_CODE (arg1
) == LSHIFT_EXPR
6591 && integer_onep (TREE_OPERAND (arg1
, 0)))
6592 return build (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
6593 build (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
6594 TREE_OPERAND (arg1
, 1)),
6595 convert (TREE_TYPE (arg0
), integer_zero_node
));
6597 else if ((code
== LT_EXPR
|| code
== GE_EXPR
)
6598 && TREE_UNSIGNED (TREE_TYPE (arg0
))
6599 && (TREE_CODE (arg1
) == NOP_EXPR
6600 || TREE_CODE (arg1
) == CONVERT_EXPR
)
6601 && TREE_CODE (TREE_OPERAND (arg1
, 0)) == LSHIFT_EXPR
6602 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0)))
6604 build (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
6605 convert (TREE_TYPE (arg0
),
6606 build (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
6607 TREE_OPERAND (TREE_OPERAND (arg1
, 0), 1))),
6608 convert (TREE_TYPE (arg0
), integer_zero_node
));
6610 /* Simplify comparison of something with itself. (For IEEE
6611 floating-point, we can only do some of these simplifications.) */
6612 if (operand_equal_p (arg0
, arg1
, 0))
6619 if (! FLOAT_TYPE_P (TREE_TYPE (arg0
)))
6620 return constant_boolean_node (1, type
);
6622 TREE_SET_CODE (t
, code
);
6626 /* For NE, we can only do this simplification if integer. */
6627 if (FLOAT_TYPE_P (TREE_TYPE (arg0
)))
6629 /* ... fall through ... */
6632 return constant_boolean_node (0, type
);
6638 /* An unsigned comparison against 0 can be simplified. */
6639 if (integer_zerop (arg1
)
6640 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
6641 || POINTER_TYPE_P (TREE_TYPE (arg1
)))
6642 && TREE_UNSIGNED (TREE_TYPE (arg1
)))
6644 switch (TREE_CODE (t
))
6648 TREE_SET_CODE (t
, NE_EXPR
);
6652 TREE_SET_CODE (t
, EQ_EXPR
);
6655 return omit_one_operand (type
,
6656 convert (type
, integer_one_node
),
6659 return omit_one_operand (type
,
6660 convert (type
, integer_zero_node
),
6667 /* Comparisons with the highest or lowest possible integer of
6668 the specified size will have known values and an unsigned
6669 <= 0x7fffffff can be simplified. */
6671 int width
= GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1
)));
6673 if (TREE_CODE (arg1
) == INTEGER_CST
6674 && ! TREE_CONSTANT_OVERFLOW (arg1
)
6675 && width
<= HOST_BITS_PER_WIDE_INT
6676 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
6677 || POINTER_TYPE_P (TREE_TYPE (arg1
))))
6679 if (TREE_INT_CST_HIGH (arg1
) == 0
6680 && (TREE_INT_CST_LOW (arg1
)
6681 == ((unsigned HOST_WIDE_INT
) 1 << (width
- 1)) - 1)
6682 && ! TREE_UNSIGNED (TREE_TYPE (arg1
)))
6683 switch (TREE_CODE (t
))
6686 return omit_one_operand (type
,
6687 convert (type
, integer_zero_node
),
6690 TREE_SET_CODE (t
, EQ_EXPR
);
6694 return omit_one_operand (type
,
6695 convert (type
, integer_one_node
),
6698 TREE_SET_CODE (t
, NE_EXPR
);
6705 else if (TREE_INT_CST_HIGH (arg1
) == -1
6706 && (- TREE_INT_CST_LOW (arg1
)
6707 == ((unsigned HOST_WIDE_INT
) 1 << (width
- 1)))
6708 && ! TREE_UNSIGNED (TREE_TYPE (arg1
)))
6709 switch (TREE_CODE (t
))
6712 return omit_one_operand (type
,
6713 convert (type
, integer_zero_node
),
6716 TREE_SET_CODE (t
, EQ_EXPR
);
6720 return omit_one_operand (type
,
6721 convert (type
, integer_one_node
),
6724 TREE_SET_CODE (t
, NE_EXPR
);
6731 else if (TREE_INT_CST_HIGH (arg1
) == 0
6732 && (TREE_INT_CST_LOW (arg1
)
6733 == ((unsigned HOST_WIDE_INT
) 1 << (width
- 1)) - 1)
6734 && TREE_UNSIGNED (TREE_TYPE (arg1
))
6735 /* signed_type does not work on pointer types. */
6736 && INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
6738 switch (TREE_CODE (t
))
6741 return fold (build (GE_EXPR
, type
,
6742 convert (signed_type (TREE_TYPE (arg0
)),
6744 convert (signed_type (TREE_TYPE (arg1
)),
6745 integer_zero_node
)));
6747 return fold (build (LT_EXPR
, type
,
6748 convert (signed_type (TREE_TYPE (arg0
)),
6750 convert (signed_type (TREE_TYPE (arg1
)),
6751 integer_zero_node
)));
6759 /* If we are comparing an expression that just has comparisons
6760 of two integer values, arithmetic expressions of those comparisons,
6761 and constants, we can simplify it. There are only three cases
6762 to check: the two values can either be equal, the first can be
6763 greater, or the second can be greater. Fold the expression for
6764 those three values. Since each value must be 0 or 1, we have
6765 eight possibilities, each of which corresponds to the constant 0
6766 or 1 or one of the six possible comparisons.
6768 This handles common cases like (a > b) == 0 but also handles
6769 expressions like ((x > y) - (y > x)) > 0, which supposedly
6770 occur in macroized code. */
6772 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) != INTEGER_CST
)
6774 tree cval1
= 0, cval2
= 0;
6777 if (twoval_comparison_p (arg0
, &cval1
, &cval2
, &save_p
)
6778 /* Don't handle degenerate cases here; they should already
6779 have been handled anyway. */
6780 && cval1
!= 0 && cval2
!= 0
6781 && ! (TREE_CONSTANT (cval1
) && TREE_CONSTANT (cval2
))
6782 && TREE_TYPE (cval1
) == TREE_TYPE (cval2
)
6783 && INTEGRAL_TYPE_P (TREE_TYPE (cval1
))
6784 && TYPE_MAX_VALUE (TREE_TYPE (cval1
))
6785 && TYPE_MAX_VALUE (TREE_TYPE (cval2
))
6786 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1
)),
6787 TYPE_MAX_VALUE (TREE_TYPE (cval2
)), 0))
6789 tree maxval
= TYPE_MAX_VALUE (TREE_TYPE (cval1
));
6790 tree minval
= TYPE_MIN_VALUE (TREE_TYPE (cval1
));
6792 /* We can't just pass T to eval_subst in case cval1 or cval2
6793 was the same as ARG1. */
6796 = fold (build (code
, type
,
6797 eval_subst (arg0
, cval1
, maxval
, cval2
, minval
),
6800 = fold (build (code
, type
,
6801 eval_subst (arg0
, cval1
, maxval
, cval2
, maxval
),
6804 = fold (build (code
, type
,
6805 eval_subst (arg0
, cval1
, minval
, cval2
, maxval
),
6808 /* All three of these results should be 0 or 1. Confirm they
6809 are. Then use those values to select the proper code
6812 if ((integer_zerop (high_result
)
6813 || integer_onep (high_result
))
6814 && (integer_zerop (equal_result
)
6815 || integer_onep (equal_result
))
6816 && (integer_zerop (low_result
)
6817 || integer_onep (low_result
)))
6819 /* Make a 3-bit mask with the high-order bit being the
6820 value for `>', the next for '=', and the low for '<'. */
6821 switch ((integer_onep (high_result
) * 4)
6822 + (integer_onep (equal_result
) * 2)
6823 + integer_onep (low_result
))
6827 return omit_one_operand (type
, integer_zero_node
, arg0
);
6848 return omit_one_operand (type
, integer_one_node
, arg0
);
6851 t
= build (code
, type
, cval1
, cval2
);
6853 return save_expr (t
);
6860 /* If this is a comparison of a field, we may be able to simplify it. */
6861 if ((TREE_CODE (arg0
) == COMPONENT_REF
6862 || TREE_CODE (arg0
) == BIT_FIELD_REF
)
6863 && (code
== EQ_EXPR
|| code
== NE_EXPR
)
6864 /* Handle the constant case even without -O
6865 to make sure the warnings are given. */
6866 && (optimize
|| TREE_CODE (arg1
) == INTEGER_CST
))
6868 t1
= optimize_bit_field_compare (code
, type
, arg0
, arg1
);
6872 /* If this is a comparison of complex values and either or both sides
6873 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6874 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6875 This may prevent needless evaluations. */
6876 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6877 && TREE_CODE (TREE_TYPE (arg0
)) == COMPLEX_TYPE
6878 && (TREE_CODE (arg0
) == COMPLEX_EXPR
6879 || TREE_CODE (arg1
) == COMPLEX_EXPR
6880 || TREE_CODE (arg0
) == COMPLEX_CST
6881 || TREE_CODE (arg1
) == COMPLEX_CST
))
6883 tree subtype
= TREE_TYPE (TREE_TYPE (arg0
));
6884 tree real0
, imag0
, real1
, imag1
;
6886 arg0
= save_expr (arg0
);
6887 arg1
= save_expr (arg1
);
6888 real0
= fold (build1 (REALPART_EXPR
, subtype
, arg0
));
6889 imag0
= fold (build1 (IMAGPART_EXPR
, subtype
, arg0
));
6890 real1
= fold (build1 (REALPART_EXPR
, subtype
, arg1
));
6891 imag1
= fold (build1 (IMAGPART_EXPR
, subtype
, arg1
));
6893 return fold (build ((code
== EQ_EXPR
? TRUTH_ANDIF_EXPR
6896 fold (build (code
, type
, real0
, real1
)),
6897 fold (build (code
, type
, imag0
, imag1
))));
6900 /* Optimize comparisons of strlen vs zero to a compare of the
6901 first character of the string vs zero. To wit,
6902 strlen(ptr) == 0 => *ptr == 0
6903 strlen(ptr) != 0 => *ptr != 0
6904 Other cases should reduce to one of these two (or a constant)
6905 due to the return value of strlen being unsigned. */
6906 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6907 && integer_zerop (arg1
)
6908 && TREE_CODE (arg0
) == CALL_EXPR
6909 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == ADDR_EXPR
)
6911 tree fndecl
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
6914 if (TREE_CODE (fndecl
) == FUNCTION_DECL
6915 && DECL_BUILT_IN (fndecl
)
6916 && DECL_BUILT_IN_CLASS (fndecl
) != BUILT_IN_MD
6917 && DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STRLEN
6918 && (arglist
= TREE_OPERAND (arg0
, 1))
6919 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist
))) == POINTER_TYPE
6920 && ! TREE_CHAIN (arglist
))
6921 return fold (build (code
, type
,
6922 build1 (INDIRECT_REF
, char_type_node
,
6923 TREE_VALUE(arglist
)),
6924 integer_zero_node
));
6927 /* From here on, the only cases we handle are when the result is
6928 known to be a constant.
6930 To compute GT, swap the arguments and do LT.
6931 To compute GE, do LT and invert the result.
6932 To compute LE, swap the arguments, do LT and invert the result.
6933 To compute NE, do EQ and invert the result.
6935 Therefore, the code below must handle only EQ and LT. */
6937 if (code
== LE_EXPR
|| code
== GT_EXPR
)
6939 tem
= arg0
, arg0
= arg1
, arg1
= tem
;
6940 code
= swap_tree_comparison (code
);
6943 /* Note that it is safe to invert for real values here because we
6944 will check below in the one case that it matters. */
6948 if (code
== NE_EXPR
|| code
== GE_EXPR
)
6951 code
= invert_tree_comparison (code
);
6954 /* Compute a result for LT or EQ if args permit;
6955 otherwise return T. */
6956 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
6958 if (code
== EQ_EXPR
)
6959 t1
= build_int_2 (tree_int_cst_equal (arg0
, arg1
), 0);
6961 t1
= build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0
))
6962 ? INT_CST_LT_UNSIGNED (arg0
, arg1
)
6963 : INT_CST_LT (arg0
, arg1
)),
6967 #if 0 /* This is no longer useful, but breaks some real code. */
6968 /* Assume a nonexplicit constant cannot equal an explicit one,
6969 since such code would be undefined anyway.
6970 Exception: on sysvr4, using #pragma weak,
6971 a label can come out as 0. */
6972 else if (TREE_CODE (arg1
) == INTEGER_CST
6973 && !integer_zerop (arg1
)
6974 && TREE_CONSTANT (arg0
)
6975 && TREE_CODE (arg0
) == ADDR_EXPR
6977 t1
= build_int_2 (0, 0);
6979 /* Two real constants can be compared explicitly. */
6980 else if (TREE_CODE (arg0
) == REAL_CST
&& TREE_CODE (arg1
) == REAL_CST
)
6982 /* If either operand is a NaN, the result is false with two
6983 exceptions: First, an NE_EXPR is true on NaNs, but that case
6984 is already handled correctly since we will be inverting the
6985 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6986 or a GE_EXPR into a LT_EXPR, we must return true so that it
6987 will be inverted into false. */
6989 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0
))
6990 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
6991 t1
= build_int_2 (invert
&& code
== LT_EXPR
, 0);
6993 else if (code
== EQ_EXPR
)
6994 t1
= build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0
),
6995 TREE_REAL_CST (arg1
)),
6998 t1
= build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0
),
6999 TREE_REAL_CST (arg1
)),
7003 if (t1
== NULL_TREE
)
7007 TREE_INT_CST_LOW (t1
) ^= 1;
7009 TREE_TYPE (t1
) = type
;
7010 if (TREE_CODE (type
) == BOOLEAN_TYPE
)
7011 return truthvalue_conversion (t1
);
7015 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
7016 so all simple results must be passed through pedantic_non_lvalue. */
7017 if (TREE_CODE (arg0
) == INTEGER_CST
)
7018 return pedantic_non_lvalue
7019 (TREE_OPERAND (t
, (integer_zerop (arg0
) ? 2 : 1)));
7020 else if (operand_equal_p (arg1
, TREE_OPERAND (expr
, 2), 0))
7021 return pedantic_omit_one_operand (type
, arg1
, arg0
);
7023 /* If the second operand is zero, invert the comparison and swap
7024 the second and third operands. Likewise if the second operand
7025 is constant and the third is not or if the third operand is
7026 equivalent to the first operand of the comparison. */
7028 if (integer_zerop (arg1
)
7029 || (TREE_CONSTANT (arg1
) && ! TREE_CONSTANT (TREE_OPERAND (t
, 2)))
7030 || (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
7031 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
7032 TREE_OPERAND (t
, 2),
7033 TREE_OPERAND (arg0
, 1))))
7035 /* See if this can be inverted. If it can't, possibly because
7036 it was a floating-point inequality comparison, don't do
7038 tem
= invert_truthvalue (arg0
);
7040 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
7042 t
= build (code
, type
, tem
,
7043 TREE_OPERAND (t
, 2), TREE_OPERAND (t
, 1));
7045 /* arg1 should be the first argument of the new T. */
7046 arg1
= TREE_OPERAND (t
, 1);
7051 /* If we have A op B ? A : C, we may be able to convert this to a
7052 simpler expression, depending on the operation and the values
7053 of B and C. IEEE floating point prevents this though,
7054 because A or B might be -0.0 or a NaN. */
7056 if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
7057 && (TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
7058 || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0
, 0)))
7059 || flag_unsafe_math_optimizations
)
7060 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
7061 arg1
, TREE_OPERAND (arg0
, 1)))
7063 tree arg2
= TREE_OPERAND (t
, 2);
7064 enum tree_code comp_code
= TREE_CODE (arg0
);
7068 /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
7069 depending on the comparison operation. */
7070 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0
, 1)))
7071 ? real_zerop (TREE_OPERAND (arg0
, 1))
7072 : integer_zerop (TREE_OPERAND (arg0
, 1)))
7073 && TREE_CODE (arg2
) == NEGATE_EXPR
7074 && operand_equal_p (TREE_OPERAND (arg2
, 0), arg1
, 0))
7082 (convert (TREE_TYPE (TREE_OPERAND (t
, 1)),
7086 return pedantic_non_lvalue (convert (type
, arg1
));
7089 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
7090 arg1
= convert (signed_type (TREE_TYPE (arg1
)), arg1
);
7091 return pedantic_non_lvalue
7092 (convert (type
, fold (build1 (ABS_EXPR
,
7093 TREE_TYPE (arg1
), arg1
))));
7096 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
7097 arg1
= convert (signed_type (TREE_TYPE (arg1
)), arg1
);
7098 return pedantic_non_lvalue
7099 (negate_expr (convert (type
,
7100 fold (build1 (ABS_EXPR
,
7107 /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
7110 if (integer_zerop (TREE_OPERAND (arg0
, 1)) && integer_zerop (arg2
))
7112 if (comp_code
== NE_EXPR
)
7113 return pedantic_non_lvalue (convert (type
, arg1
));
7114 else if (comp_code
== EQ_EXPR
)
7115 return pedantic_non_lvalue (convert (type
, integer_zero_node
));
7118 /* If this is A op B ? A : B, this is either A, B, min (A, B),
7119 or max (A, B), depending on the operation. */
7121 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 1),
7122 arg2
, TREE_OPERAND (arg0
, 0)))
7124 tree comp_op0
= TREE_OPERAND (arg0
, 0);
7125 tree comp_op1
= TREE_OPERAND (arg0
, 1);
7126 tree comp_type
= TREE_TYPE (comp_op0
);
7128 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
7129 if (TYPE_MAIN_VARIANT (comp_type
) == TYPE_MAIN_VARIANT (type
))
7135 return pedantic_non_lvalue (convert (type
, arg2
));
7137 return pedantic_non_lvalue (convert (type
, arg1
));
7140 /* In C++ a ?: expression can be an lvalue, so put the
7141 operand which will be used if they are equal first
7142 so that we can convert this back to the
7143 corresponding COND_EXPR. */
7144 return pedantic_non_lvalue
7145 (convert (type
, fold (build (MIN_EXPR
, comp_type
,
7146 (comp_code
== LE_EXPR
7147 ? comp_op0
: comp_op1
),
7148 (comp_code
== LE_EXPR
7149 ? comp_op1
: comp_op0
)))));
7153 return pedantic_non_lvalue
7154 (convert (type
, fold (build (MAX_EXPR
, comp_type
,
7155 (comp_code
== GE_EXPR
7156 ? comp_op0
: comp_op1
),
7157 (comp_code
== GE_EXPR
7158 ? comp_op1
: comp_op0
)))));
7165 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
7166 we might still be able to simplify this. For example,
7167 if C1 is one less or one more than C2, this might have started
7168 out as a MIN or MAX and been transformed by this function.
7169 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
7171 if (INTEGRAL_TYPE_P (type
)
7172 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
7173 && TREE_CODE (arg2
) == INTEGER_CST
)
7177 /* We can replace A with C1 in this case. */
7178 arg1
= convert (type
, TREE_OPERAND (arg0
, 1));
7179 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
,
7180 TREE_OPERAND (t
, 2));
7184 /* If C1 is C2 + 1, this is min(A, C2). */
7185 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
7186 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7187 const_binop (PLUS_EXPR
, arg2
,
7188 integer_one_node
, 0), 1))
7189 return pedantic_non_lvalue
7190 (fold (build (MIN_EXPR
, type
, arg1
, arg2
)));
7194 /* If C1 is C2 - 1, this is min(A, C2). */
7195 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
7196 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7197 const_binop (MINUS_EXPR
, arg2
,
7198 integer_one_node
, 0), 1))
7199 return pedantic_non_lvalue
7200 (fold (build (MIN_EXPR
, type
, arg1
, arg2
)));
7204 /* If C1 is C2 - 1, this is max(A, C2). */
7205 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
7206 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7207 const_binop (MINUS_EXPR
, arg2
,
7208 integer_one_node
, 0), 1))
7209 return pedantic_non_lvalue
7210 (fold (build (MAX_EXPR
, type
, arg1
, arg2
)));
7214 /* If C1 is C2 + 1, this is max(A, C2). */
7215 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
7216 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7217 const_binop (PLUS_EXPR
, arg2
,
7218 integer_one_node
, 0), 1))
7219 return pedantic_non_lvalue
7220 (fold (build (MAX_EXPR
, type
, arg1
, arg2
)));
7229 /* If the second operand is simpler than the third, swap them
7230 since that produces better jump optimization results. */
7231 if ((TREE_CONSTANT (arg1
) || DECL_P (arg1
)
7232 || TREE_CODE (arg1
) == SAVE_EXPR
)
7233 && ! (TREE_CONSTANT (TREE_OPERAND (t
, 2))
7234 || DECL_P (TREE_OPERAND (t
, 2))
7235 || TREE_CODE (TREE_OPERAND (t
, 2)) == SAVE_EXPR
))
7237 /* See if this can be inverted. If it can't, possibly because
7238 it was a floating-point inequality comparison, don't do
7240 tem
= invert_truthvalue (arg0
);
7242 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
7244 t
= build (code
, type
, tem
,
7245 TREE_OPERAND (t
, 2), TREE_OPERAND (t
, 1));
7247 /* arg1 should be the first argument of the new T. */
7248 arg1
= TREE_OPERAND (t
, 1);
7253 /* Convert A ? 1 : 0 to simply A. */
7254 if (integer_onep (TREE_OPERAND (t
, 1))
7255 && integer_zerop (TREE_OPERAND (t
, 2))
7256 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7257 call to fold will try to move the conversion inside
7258 a COND, which will recurse. In that case, the COND_EXPR
7259 is probably the best choice, so leave it alone. */
7260 && type
== TREE_TYPE (arg0
))
7261 return pedantic_non_lvalue (arg0
);
7263 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7264 operation is simply A & 2. */
7266 if (integer_zerop (TREE_OPERAND (t
, 2))
7267 && TREE_CODE (arg0
) == NE_EXPR
7268 && integer_zerop (TREE_OPERAND (arg0
, 1))
7269 && integer_pow2p (arg1
)
7270 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == BIT_AND_EXPR
7271 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1),
7273 return pedantic_non_lvalue (convert (type
, TREE_OPERAND (arg0
, 0)));
7278 /* When pedantic, a compound expression can be neither an lvalue
7279 nor an integer constant expression. */
7280 if (TREE_SIDE_EFFECTS (arg0
) || pedantic
)
7282 /* Don't let (0, 0) be null pointer constant. */
7283 if (integer_zerop (arg1
))
7284 return build1 (NOP_EXPR
, type
, arg1
);
7285 return convert (type
, arg1
);
7289 return build_complex (type
, arg0
, arg1
);
7293 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
7295 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
7296 return omit_one_operand (type
, TREE_OPERAND (arg0
, 0),
7297 TREE_OPERAND (arg0
, 1));
7298 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
7299 return TREE_REALPART (arg0
);
7300 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
7301 return fold (build (TREE_CODE (arg0
), type
,
7302 fold (build1 (REALPART_EXPR
, type
,
7303 TREE_OPERAND (arg0
, 0))),
7304 fold (build1 (REALPART_EXPR
,
7305 type
, TREE_OPERAND (arg0
, 1)))));
7309 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
7310 return convert (type
, integer_zero_node
);
7311 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
7312 return omit_one_operand (type
, TREE_OPERAND (arg0
, 1),
7313 TREE_OPERAND (arg0
, 0));
7314 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
7315 return TREE_IMAGPART (arg0
);
7316 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
7317 return fold (build (TREE_CODE (arg0
), type
,
7318 fold (build1 (IMAGPART_EXPR
, type
,
7319 TREE_OPERAND (arg0
, 0))),
7320 fold (build1 (IMAGPART_EXPR
, type
,
7321 TREE_OPERAND (arg0
, 1)))));
7324 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7326 case CLEANUP_POINT_EXPR
:
7327 if (! has_cleanups (arg0
))
7328 return TREE_OPERAND (t
, 0);
7331 enum tree_code code0
= TREE_CODE (arg0
);
7332 int kind0
= TREE_CODE_CLASS (code0
);
7333 tree arg00
= TREE_OPERAND (arg0
, 0);
7336 if (kind0
== '1' || code0
== TRUTH_NOT_EXPR
)
7337 return fold (build1 (code0
, type
,
7338 fold (build1 (CLEANUP_POINT_EXPR
,
7339 TREE_TYPE (arg00
), arg00
))));
7341 if (kind0
== '<' || kind0
== '2'
7342 || code0
== TRUTH_ANDIF_EXPR
|| code0
== TRUTH_ORIF_EXPR
7343 || code0
== TRUTH_AND_EXPR
|| code0
== TRUTH_OR_EXPR
7344 || code0
== TRUTH_XOR_EXPR
)
7346 arg01
= TREE_OPERAND (arg0
, 1);
7348 if (TREE_CONSTANT (arg00
)
7349 || ((code0
== TRUTH_ANDIF_EXPR
|| code0
== TRUTH_ORIF_EXPR
)
7350 && ! has_cleanups (arg00
)))
7351 return fold (build (code0
, type
, arg00
,
7352 fold (build1 (CLEANUP_POINT_EXPR
,
7353 TREE_TYPE (arg01
), arg01
))));
7355 if (TREE_CONSTANT (arg01
))
7356 return fold (build (code0
, type
,
7357 fold (build1 (CLEANUP_POINT_EXPR
,
7358 TREE_TYPE (arg00
), arg00
)),
7366 /* Check for a built-in function. */
7367 if (TREE_CODE (TREE_OPERAND (expr
, 0)) == ADDR_EXPR
7368 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr
, 0), 0))
7370 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr
, 0), 0)))
7372 tree tmp
= fold_builtin (expr
);
7380 } /* switch (code) */
7383 /* Determine if first argument is a multiple of second argument. Return 0 if
7384 it is not, or we cannot easily determined it to be.
7386 An example of the sort of thing we care about (at this point; this routine
7387 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7388 fold cases do now) is discovering that
7390 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7396 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7398 This code also handles discovering that
7400 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7402 is a multiple of 8 so we don't have to worry about dealing with a
7405 Note that we *look* inside a SAVE_EXPR only to determine how it was
7406 calculated; it is not safe for fold to do much of anything else with the
7407 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7408 at run time. For example, the latter example above *cannot* be implemented
7409 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7410 evaluation time of the original SAVE_EXPR is not necessarily the same at
7411 the time the new expression is evaluated. The only optimization of this
7412 sort that would be valid is changing
7414 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7418 SAVE_EXPR (I) * SAVE_EXPR (J)
7420 (where the same SAVE_EXPR (J) is used in the original and the
7421 transformed version). */
7424 multiple_of_p (type
, top
, bottom
)
7429 if (operand_equal_p (top
, bottom
, 0))
7432 if (TREE_CODE (type
) != INTEGER_TYPE
)
7435 switch (TREE_CODE (top
))
7438 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
7439 || multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
7443 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
7444 && multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
7447 if (TREE_CODE (TREE_OPERAND (top
, 1)) == INTEGER_CST
)
7451 op1
= TREE_OPERAND (top
, 1);
7452 /* const_binop may not detect overflow correctly,
7453 so check for it explicitly here. */
7454 if (TYPE_PRECISION (TREE_TYPE (size_one_node
))
7455 > TREE_INT_CST_LOW (op1
)
7456 && TREE_INT_CST_HIGH (op1
) == 0
7457 && 0 != (t1
= convert (type
,
7458 const_binop (LSHIFT_EXPR
, size_one_node
,
7460 && ! TREE_OVERFLOW (t1
))
7461 return multiple_of_p (type
, t1
, bottom
);
7466 /* Can't handle conversions from non-integral or wider integral type. */
7467 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top
, 0))) != INTEGER_TYPE
)
7468 || (TYPE_PRECISION (type
)
7469 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top
, 0)))))
7472 /* .. fall through ... */
7475 return multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
);
7478 if (TREE_CODE (bottom
) != INTEGER_CST
7479 || (TREE_UNSIGNED (type
)
7480 && (tree_int_cst_sgn (top
) < 0
7481 || tree_int_cst_sgn (bottom
) < 0)))
7483 return integer_zerop (const_binop (TRUNC_MOD_EXPR
,
7491 /* Return true if `t' is known to be non-negative. */
7494 tree_expr_nonnegative_p (t
)
7497 switch (TREE_CODE (t
))
7503 return tree_int_cst_sgn (t
) >= 0;
7504 case TRUNC_DIV_EXPR
:
7506 case FLOOR_DIV_EXPR
:
7507 case ROUND_DIV_EXPR
:
7508 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
7509 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7510 case TRUNC_MOD_EXPR
:
7512 case FLOOR_MOD_EXPR
:
7513 case ROUND_MOD_EXPR
:
7514 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
7516 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1))
7517 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 2));
7519 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7521 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
7522 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7524 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
7525 || tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7527 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7529 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7531 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
7532 case NON_LVALUE_EXPR
:
7533 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
7535 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t
));
7538 if (truth_value_p (TREE_CODE (t
)))
7539 /* Truth values evaluate to 0 or 1, which is nonnegative. */
7542 /* We don't know sign of `t', so be conservative and return false. */
7547 /* Return true if `r' is known to be non-negative.
7548 Only handles constants at the moment. */
7551 rtl_expr_nonnegative_p (r
)
7554 switch (GET_CODE (r
))
7557 return INTVAL (r
) >= 0;
7560 if (GET_MODE (r
) == VOIDmode
)
7561 return CONST_DOUBLE_HIGH (r
) >= 0;
7566 /* These are always nonnegative. */