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2bc77e10 | 1 | /* Fold a constant sub-tree into a single node for C-compiler |
d50b22af | 2 | Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 2002, |
a3f632bd | 3 | 1999, 2000, 2001, 2002 Free Software Foundation, Inc. |
2bc77e10 | 4 | |
f12b58b3 | 5 | This file is part of GCC. |
2bc77e10 | 6 | |
f12b58b3 | 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 | |
10 | version. | |
2bc77e10 | 11 | |
f12b58b3 | 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 | |
15 | for more details. | |
2bc77e10 | 16 | |
17 | You should have received a copy of the GNU General Public License | |
f12b58b3 | 18 | along with GCC; see the file COPYING. If not, write to the Free |
19 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
20 | 02111-1307, USA. */ | |
2bc77e10 | 21 | |
4bbea254 | 22 | /*@@ This file should be rewritten to use an arbitrary precision |
2bc77e10 | 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. */ | |
29 | ||
30384dcf | 30 | /* The entry points in this file are fold, size_int_wide, size_binop |
6e44befc | 31 | and force_fit_type. |
2bc77e10 | 32 | |
33 | fold takes a tree as argument and returns a simplified tree. | |
34 | ||
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'. | |
38 | ||
39 | size_int takes an integer value, and creates a tree constant | |
6e44befc | 40 | with type from `sizetype'. |
41 | ||
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. */ | |
44 | ||
0dbd1c74 | 45 | #include "config.h" |
5ee8fe30 | 46 | #include "system.h" |
2bc77e10 | 47 | #include "flags.h" |
48 | #include "tree.h" | |
ef258422 | 49 | #include "real.h" |
0f9685e4 | 50 | #include "rtl.h" |
aed0bd19 | 51 | #include "expr.h" |
7953c610 | 52 | #include "tm_p.h" |
12874aaf | 53 | #include "toplev.h" |
1bfd55c5 | 54 | #include "ggc.h" |
15d769aa | 55 | #include "hashtab.h" |
20325f61 | 56 | #include "langhooks.h" |
2bc77e10 | 57 | |
621f6678 | 58 | static void encode PARAMS ((HOST_WIDE_INT *, |
a0c2c45b | 59 | unsigned HOST_WIDE_INT, |
60 | HOST_WIDE_INT)); | |
621f6678 | 61 | static void decode PARAMS ((HOST_WIDE_INT *, |
a0c2c45b | 62 | unsigned HOST_WIDE_INT *, |
621f6678 | 63 | HOST_WIDE_INT *)); |
64 | static tree negate_expr PARAMS ((tree)); | |
65 | static tree split_tree PARAMS ((tree, enum tree_code, tree *, tree *, | |
b07ba9ff | 66 | tree *, int)); |
621f6678 | 67 | static tree associate_trees PARAMS ((tree, tree, enum tree_code, tree)); |
15d769aa | 68 | static tree int_const_binop PARAMS ((enum tree_code, tree, tree, int)); |
621f6678 | 69 | static tree const_binop PARAMS ((enum tree_code, tree, tree, int)); |
15d769aa | 70 | static hashval_t size_htab_hash PARAMS ((const void *)); |
71 | static int size_htab_eq PARAMS ((const void *, const void *)); | |
621f6678 | 72 | static tree fold_convert PARAMS ((tree, tree)); |
73 | static enum tree_code invert_tree_comparison PARAMS ((enum tree_code)); | |
74 | static enum tree_code swap_tree_comparison PARAMS ((enum tree_code)); | |
7835f163 | 75 | static int comparison_to_compcode PARAMS ((enum tree_code)); |
76 | static enum tree_code compcode_to_comparison PARAMS ((int)); | |
621f6678 | 77 | static int truth_value_p PARAMS ((enum tree_code)); |
78 | static int operand_equal_for_comparison_p PARAMS ((tree, tree, tree)); | |
79 | static int twoval_comparison_p PARAMS ((tree, tree *, tree *, int *)); | |
80 | static tree eval_subst PARAMS ((tree, tree, tree, tree, tree)); | |
81 | static tree omit_one_operand PARAMS ((tree, tree, tree)); | |
82 | static tree pedantic_omit_one_operand PARAMS ((tree, tree, tree)); | |
83 | static tree distribute_bit_expr PARAMS ((enum tree_code, tree, tree, tree)); | |
84 | static tree make_bit_field_ref PARAMS ((tree, tree, int, int, int)); | |
85 | static tree optimize_bit_field_compare PARAMS ((enum tree_code, tree, | |
86 | tree, tree)); | |
02e7a332 | 87 | static tree decode_field_reference PARAMS ((tree, HOST_WIDE_INT *, |
88 | HOST_WIDE_INT *, | |
621f6678 | 89 | enum machine_mode *, int *, |
90 | int *, tree *, tree *)); | |
91 | static int all_ones_mask_p PARAMS ((tree, int)); | |
203a24c4 | 92 | static tree sign_bit_p PARAMS ((tree, tree)); |
621f6678 | 93 | static int simple_operand_p PARAMS ((tree)); |
94 | static tree range_binop PARAMS ((enum tree_code, tree, tree, int, | |
95 | 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, | |
12ec0a8a | 99 | int, tree, tree)); |
621f6678 | 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)); | |
d3371fcd | 109 | static tree fold_binary_op_with_conditional_arg |
47cbd05d | 110 | PARAMS ((enum tree_code, tree, tree, tree, int)); |
920d0fb5 | 111 | static bool fold_real_zero_addition_p PARAMS ((tree, tree, int)); |
d3371fcd | 112 | |
7835f163 | 113 | /* The following constants represent a bit based encoding of GCC's |
114 | comparison operators. This encoding simplifies transformations | |
115 | on relational comparison operators, such as AND and OR. */ | |
116 | #define COMPCODE_FALSE 0 | |
117 | #define COMPCODE_LT 1 | |
118 | #define COMPCODE_EQ 2 | |
119 | #define COMPCODE_LE 3 | |
120 | #define COMPCODE_GT 4 | |
121 | #define COMPCODE_NE 5 | |
122 | #define COMPCODE_GE 6 | |
123 | #define COMPCODE_TRUE 7 | |
124 | ||
083a2b5e | 125 | /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring |
126 | overflow. Suppose A, B and SUM have the same respective signs as A1, B1, | |
127 | and SUM1. Then this yields nonzero if overflow occurred during the | |
128 | addition. | |
129 | ||
130 | Overflow occurs if A and B have the same sign, but A and SUM differ in | |
131 | sign. Use `^' to test whether signs differ, and `< 0' to isolate the | |
132 | sign. */ | |
133 | #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0) | |
2bc77e10 | 134 | \f |
b572011e | 135 | /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic. |
bd5b3bce | 136 | We do that by representing the two-word integer in 4 words, with only |
083a2b5e | 137 | HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive |
138 | number. The value of the word is LOWPART + HIGHPART * BASE. */ | |
bd5b3bce | 139 | |
140 | #define LOWPART(x) \ | |
083a2b5e | 141 | ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1)) |
bd5b3bce | 142 | #define HIGHPART(x) \ |
083a2b5e | 143 | ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2) |
144 | #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2) | |
2bc77e10 | 145 | |
bd5b3bce | 146 | /* Unpack a two-word integer into 4 words. |
b572011e | 147 | LOW and HI are the integer, as two `HOST_WIDE_INT' pieces. |
bd5b3bce | 148 | WORDS points to the array of HOST_WIDE_INTs. */ |
2bc77e10 | 149 | |
150 | static void | |
bd5b3bce | 151 | encode (words, low, hi) |
152 | HOST_WIDE_INT *words; | |
a0c2c45b | 153 | unsigned HOST_WIDE_INT low; |
154 | HOST_WIDE_INT hi; | |
2bc77e10 | 155 | { |
bd5b3bce | 156 | words[0] = LOWPART (low); |
157 | words[1] = HIGHPART (low); | |
158 | words[2] = LOWPART (hi); | |
159 | words[3] = HIGHPART (hi); | |
2bc77e10 | 160 | } |
161 | ||
bd5b3bce | 162 | /* Pack an array of 4 words into a two-word integer. |
163 | WORDS points to the array of words. | |
b572011e | 164 | The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */ |
2bc77e10 | 165 | |
166 | static void | |
bd5b3bce | 167 | decode (words, low, hi) |
168 | HOST_WIDE_INT *words; | |
a0c2c45b | 169 | unsigned HOST_WIDE_INT *low; |
170 | HOST_WIDE_INT *hi; | |
2bc77e10 | 171 | { |
083a2b5e | 172 | *low = words[0] + words[1] * BASE; |
173 | *hi = words[2] + words[3] * BASE; | |
2bc77e10 | 174 | } |
175 | \f | |
083a2b5e | 176 | /* Make the integer constant T valid for its type by setting to 0 or 1 all |
177 | the bits in the constant that don't belong in the type. | |
178 | ||
179 | Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is | |
180 | nonzero, a signed overflow has already occurred in calculating T, so | |
aa870c1b | 181 | propagate it. */ |
2bc77e10 | 182 | |
f55401f0 | 183 | int |
184 | force_fit_type (t, overflow) | |
2bc77e10 | 185 | tree t; |
f55401f0 | 186 | int overflow; |
2bc77e10 | 187 | { |
a0c2c45b | 188 | unsigned HOST_WIDE_INT low; |
189 | HOST_WIDE_INT high; | |
190 | unsigned int prec; | |
2bc77e10 | 191 | |
23fed9b2 | 192 | if (TREE_CODE (t) == REAL_CST) |
193 | { | |
aa870c1b | 194 | /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE. |
195 | Consider doing it via real_convert now. */ | |
23fed9b2 | 196 | return overflow; |
197 | } | |
198 | ||
199 | else if (TREE_CODE (t) != INTEGER_CST) | |
817e5691 | 200 | return overflow; |
201 | ||
202 | low = TREE_INT_CST_LOW (t); | |
203 | high = TREE_INT_CST_HIGH (t); | |
d7b6c802 | 204 | |
997d68fe | 205 | if (POINTER_TYPE_P (TREE_TYPE (t))) |
2bc77e10 | 206 | prec = POINTER_SIZE; |
817e5691 | 207 | else |
208 | prec = TYPE_PRECISION (TREE_TYPE (t)); | |
2bc77e10 | 209 | |
210 | /* First clear all bits that are beyond the type's precision. */ | |
211 | ||
b572011e | 212 | if (prec == 2 * HOST_BITS_PER_WIDE_INT) |
2bc77e10 | 213 | ; |
b572011e | 214 | else if (prec > HOST_BITS_PER_WIDE_INT) |
083a2b5e | 215 | TREE_INT_CST_HIGH (t) |
216 | &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT)); | |
2bc77e10 | 217 | else |
218 | { | |
219 | TREE_INT_CST_HIGH (t) = 0; | |
b572011e | 220 | if (prec < HOST_BITS_PER_WIDE_INT) |
a0c2c45b | 221 | TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec); |
2bc77e10 | 222 | } |
223 | ||
708d4303 | 224 | /* Unsigned types do not suffer sign extension or overflow unless they |
225 | are a sizetype. */ | |
226 | if (TREE_UNSIGNED (TREE_TYPE (t)) | |
227 | && ! (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE | |
228 | && TYPE_IS_SIZETYPE (TREE_TYPE (t)))) | |
941709f7 | 229 | return overflow; |
2bc77e10 | 230 | |
f55401f0 | 231 | /* If the value's sign bit is set, extend the sign. */ |
232 | if (prec != 2 * HOST_BITS_PER_WIDE_INT | |
b572011e | 233 | && (prec > HOST_BITS_PER_WIDE_INT |
a0c2c45b | 234 | ? 0 != (TREE_INT_CST_HIGH (t) |
235 | & ((HOST_WIDE_INT) 1 | |
236 | << (prec - HOST_BITS_PER_WIDE_INT - 1))) | |
237 | : 0 != (TREE_INT_CST_LOW (t) | |
238 | & ((unsigned HOST_WIDE_INT) 1 << (prec - 1))))) | |
2bc77e10 | 239 | { |
240 | /* Value is negative: | |
241 | set to 1 all the bits that are outside this type's precision. */ | |
b572011e | 242 | if (prec > HOST_BITS_PER_WIDE_INT) |
083a2b5e | 243 | TREE_INT_CST_HIGH (t) |
244 | |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT)); | |
2bc77e10 | 245 | else |
246 | { | |
247 | TREE_INT_CST_HIGH (t) = -1; | |
b572011e | 248 | if (prec < HOST_BITS_PER_WIDE_INT) |
a0c2c45b | 249 | TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec); |
2bc77e10 | 250 | } |
251 | } | |
f55401f0 | 252 | |
083a2b5e | 253 | /* Return nonzero if signed overflow occurred. */ |
f55401f0 | 254 | return |
255 | ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t))) | |
256 | != 0); | |
2bc77e10 | 257 | } |
258 | \f | |
b572011e | 259 | /* Add two doubleword integers with doubleword result. |
260 | Each argument is given as two `HOST_WIDE_INT' pieces. | |
2bc77e10 | 261 | One argument is L1 and H1; the other, L2 and H2. |
bd5b3bce | 262 | The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */ |
2bc77e10 | 263 | |
b9e999f0 | 264 | int |
2bc77e10 | 265 | add_double (l1, h1, l2, h2, lv, hv) |
a0c2c45b | 266 | unsigned HOST_WIDE_INT l1, l2; |
267 | HOST_WIDE_INT h1, h2; | |
268 | unsigned HOST_WIDE_INT *lv; | |
269 | HOST_WIDE_INT *hv; | |
2bc77e10 | 270 | { |
a0c2c45b | 271 | unsigned HOST_WIDE_INT l; |
272 | HOST_WIDE_INT h; | |
2bc77e10 | 273 | |
bd5b3bce | 274 | l = l1 + l2; |
a0c2c45b | 275 | h = h1 + h2 + (l < l1); |
2bc77e10 | 276 | |
bd5b3bce | 277 | *lv = l; |
278 | *hv = h; | |
083a2b5e | 279 | return OVERFLOW_SUM_SIGN (h1, h2, h); |
2bc77e10 | 280 | } |
281 | ||
b572011e | 282 | /* Negate a doubleword integer with doubleword result. |
b9e999f0 | 283 | Return nonzero if the operation overflows, assuming it's signed. |
b572011e | 284 | The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1. |
bd5b3bce | 285 | The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */ |
2bc77e10 | 286 | |
b9e999f0 | 287 | int |
2bc77e10 | 288 | neg_double (l1, h1, lv, hv) |
a0c2c45b | 289 | unsigned HOST_WIDE_INT l1; |
290 | HOST_WIDE_INT h1; | |
291 | unsigned HOST_WIDE_INT *lv; | |
292 | HOST_WIDE_INT *hv; | |
2bc77e10 | 293 | { |
294 | if (l1 == 0) | |
295 | { | |
296 | *lv = 0; | |
297 | *hv = - h1; | |
f55401f0 | 298 | return (*hv & h1) < 0; |
2bc77e10 | 299 | } |
300 | else | |
301 | { | |
cc049fa3 | 302 | *lv = -l1; |
303 | *hv = ~h1; | |
b9e999f0 | 304 | return 0; |
2bc77e10 | 305 | } |
306 | } | |
307 | \f | |
b572011e | 308 | /* Multiply two doubleword integers with doubleword result. |
b9e999f0 | 309 | Return nonzero if the operation overflows, assuming it's signed. |
b572011e | 310 | Each argument is given as two `HOST_WIDE_INT' pieces. |
2bc77e10 | 311 | One argument is L1 and H1; the other, L2 and H2. |
bd5b3bce | 312 | The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */ |
2bc77e10 | 313 | |
b9e999f0 | 314 | int |
2bc77e10 | 315 | mul_double (l1, h1, l2, h2, lv, hv) |
a0c2c45b | 316 | unsigned HOST_WIDE_INT l1, l2; |
317 | HOST_WIDE_INT h1, h2; | |
318 | unsigned HOST_WIDE_INT *lv; | |
319 | HOST_WIDE_INT *hv; | |
2bc77e10 | 320 | { |
bd5b3bce | 321 | HOST_WIDE_INT arg1[4]; |
322 | HOST_WIDE_INT arg2[4]; | |
323 | HOST_WIDE_INT prod[4 * 2]; | |
19cb6b50 | 324 | unsigned HOST_WIDE_INT carry; |
325 | int i, j, k; | |
a0c2c45b | 326 | unsigned HOST_WIDE_INT toplow, neglow; |
327 | HOST_WIDE_INT tophigh, neghigh; | |
2bc77e10 | 328 | |
2bc77e10 | 329 | encode (arg1, l1, h1); |
330 | encode (arg2, l2, h2); | |
331 | ||
93d3b7de | 332 | memset ((char *) prod, 0, sizeof prod); |
2bc77e10 | 333 | |
bd5b3bce | 334 | for (i = 0; i < 4; i++) |
335 | { | |
336 | carry = 0; | |
337 | for (j = 0; j < 4; j++) | |
338 | { | |
339 | k = i + j; | |
340 | /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */ | |
341 | carry += arg1[i] * arg2[j]; | |
342 | /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */ | |
343 | carry += prod[k]; | |
344 | prod[k] = LOWPART (carry); | |
345 | carry = HIGHPART (carry); | |
346 | } | |
347 | prod[i + 4] = carry; | |
348 | } | |
2bc77e10 | 349 | |
bd5b3bce | 350 | decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */ |
b9e999f0 | 351 | |
352 | /* Check for overflow by calculating the top half of the answer in full; | |
353 | it should agree with the low half's sign bit. */ | |
cc049fa3 | 354 | decode (prod + 4, &toplow, &tophigh); |
b9e999f0 | 355 | if (h1 < 0) |
356 | { | |
357 | neg_double (l2, h2, &neglow, &neghigh); | |
358 | add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh); | |
359 | } | |
360 | if (h2 < 0) | |
361 | { | |
362 | neg_double (l1, h1, &neglow, &neghigh); | |
363 | add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh); | |
364 | } | |
365 | return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0; | |
2bc77e10 | 366 | } |
367 | \f | |
b572011e | 368 | /* Shift the doubleword integer in L1, H1 left by COUNT places |
2bc77e10 | 369 | keeping only PREC bits of result. |
370 | Shift right if COUNT is negative. | |
371 | ARITH nonzero specifies arithmetic shifting; otherwise use logical shift. | |
b572011e | 372 | Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */ |
2bc77e10 | 373 | |
f55401f0 | 374 | void |
2bc77e10 | 375 | lshift_double (l1, h1, count, prec, lv, hv, arith) |
a0c2c45b | 376 | unsigned HOST_WIDE_INT l1; |
377 | HOST_WIDE_INT h1, count; | |
378 | unsigned int prec; | |
379 | unsigned HOST_WIDE_INT *lv; | |
380 | HOST_WIDE_INT *hv; | |
2bc77e10 | 381 | int arith; |
382 | { | |
7c5b13dc | 383 | unsigned HOST_WIDE_INT signmask; |
384 | ||
2bc77e10 | 385 | if (count < 0) |
386 | { | |
cc049fa3 | 387 | rshift_double (l1, h1, -count, prec, lv, hv, arith); |
f55401f0 | 388 | return; |
2bc77e10 | 389 | } |
cc049fa3 | 390 | |
0bb60c65 | 391 | #ifdef SHIFT_COUNT_TRUNCATED |
392 | if (SHIFT_COUNT_TRUNCATED) | |
393 | count %= prec; | |
394 | #endif | |
2bc77e10 | 395 | |
016d117a | 396 | if (count >= 2 * HOST_BITS_PER_WIDE_INT) |
397 | { | |
398 | /* Shifting by the host word size is undefined according to the | |
399 | ANSI standard, so we must handle this as a special case. */ | |
400 | *hv = 0; | |
401 | *lv = 0; | |
402 | } | |
403 | else if (count >= HOST_BITS_PER_WIDE_INT) | |
2bc77e10 | 404 | { |
a0c2c45b | 405 | *hv = l1 << (count - HOST_BITS_PER_WIDE_INT); |
bd5b3bce | 406 | *lv = 0; |
407 | } | |
408 | else | |
409 | { | |
410 | *hv = (((unsigned HOST_WIDE_INT) h1 << count) | |
a0c2c45b | 411 | | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1)); |
412 | *lv = l1 << count; | |
2bc77e10 | 413 | } |
7c5b13dc | 414 | |
415 | /* Sign extend all bits that are beyond the precision. */ | |
416 | ||
417 | signmask = -((prec > HOST_BITS_PER_WIDE_INT | |
f9a532b0 | 418 | ? ((unsigned HOST_WIDE_INT) *hv |
d3371fcd | 419 | >> (prec - HOST_BITS_PER_WIDE_INT - 1)) |
7c5b13dc | 420 | : (*lv >> (prec - 1))) & 1); |
421 | ||
422 | if (prec >= 2 * HOST_BITS_PER_WIDE_INT) | |
423 | ; | |
424 | else if (prec >= HOST_BITS_PER_WIDE_INT) | |
425 | { | |
426 | *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT)); | |
427 | *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT); | |
428 | } | |
429 | else | |
430 | { | |
431 | *hv = signmask; | |
432 | *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec); | |
433 | *lv |= signmask << prec; | |
434 | } | |
2bc77e10 | 435 | } |
436 | ||
b572011e | 437 | /* Shift the doubleword integer in L1, H1 right by COUNT places |
2bc77e10 | 438 | keeping only PREC bits of result. COUNT must be positive. |
439 | ARITH nonzero specifies arithmetic shifting; otherwise use logical shift. | |
b572011e | 440 | Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */ |
2bc77e10 | 441 | |
442 | void | |
443 | rshift_double (l1, h1, count, prec, lv, hv, arith) | |
a0c2c45b | 444 | unsigned HOST_WIDE_INT l1; |
445 | HOST_WIDE_INT h1, count; | |
7c5b13dc | 446 | unsigned int prec; |
a0c2c45b | 447 | unsigned HOST_WIDE_INT *lv; |
448 | HOST_WIDE_INT *hv; | |
2bc77e10 | 449 | int arith; |
450 | { | |
bd5b3bce | 451 | unsigned HOST_WIDE_INT signmask; |
a0c2c45b | 452 | |
bd5b3bce | 453 | signmask = (arith |
454 | ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1)) | |
455 | : 0); | |
2bc77e10 | 456 | |
0bb60c65 | 457 | #ifdef SHIFT_COUNT_TRUNCATED |
458 | if (SHIFT_COUNT_TRUNCATED) | |
459 | count %= prec; | |
460 | #endif | |
2bc77e10 | 461 | |
016d117a | 462 | if (count >= 2 * HOST_BITS_PER_WIDE_INT) |
463 | { | |
464 | /* Shifting by the host word size is undefined according to the | |
465 | ANSI standard, so we must handle this as a special case. */ | |
7c5b13dc | 466 | *hv = 0; |
467 | *lv = 0; | |
016d117a | 468 | } |
469 | else if (count >= HOST_BITS_PER_WIDE_INT) | |
2bc77e10 | 470 | { |
7c5b13dc | 471 | *hv = 0; |
472 | *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT); | |
bd5b3bce | 473 | } |
474 | else | |
475 | { | |
7c5b13dc | 476 | *hv = (unsigned HOST_WIDE_INT) h1 >> count; |
a0c2c45b | 477 | *lv = ((l1 >> count) |
5ee8fe30 | 478 | | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1)); |
7c5b13dc | 479 | } |
480 | ||
481 | /* Zero / sign extend all bits that are beyond the precision. */ | |
482 | ||
483 | if (count >= (HOST_WIDE_INT)prec) | |
484 | { | |
485 | *hv = signmask; | |
486 | *lv = signmask; | |
487 | } | |
488 | else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT) | |
489 | ; | |
490 | else if ((prec - count) >= HOST_BITS_PER_WIDE_INT) | |
491 | { | |
492 | *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT)); | |
493 | *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT); | |
494 | } | |
495 | else | |
496 | { | |
497 | *hv = signmask; | |
498 | *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count)); | |
499 | *lv |= signmask << (prec - count); | |
2bc77e10 | 500 | } |
2bc77e10 | 501 | } |
502 | \f | |
bd5b3bce | 503 | /* Rotate the doubleword integer in L1, H1 left by COUNT places |
2bc77e10 | 504 | keeping only PREC bits of result. |
505 | Rotate right if COUNT is negative. | |
b572011e | 506 | Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */ |
2bc77e10 | 507 | |
508 | void | |
509 | lrotate_double (l1, h1, count, prec, lv, hv) | |
a0c2c45b | 510 | unsigned HOST_WIDE_INT l1; |
511 | HOST_WIDE_INT h1, count; | |
512 | unsigned int prec; | |
513 | unsigned HOST_WIDE_INT *lv; | |
514 | HOST_WIDE_INT *hv; | |
2bc77e10 | 515 | { |
a0c2c45b | 516 | unsigned HOST_WIDE_INT s1l, s2l; |
517 | HOST_WIDE_INT s1h, s2h; | |
2bc77e10 | 518 | |
7a1b56a9 | 519 | count %= prec; |
2bc77e10 | 520 | if (count < 0) |
7a1b56a9 | 521 | count += prec; |
2bc77e10 | 522 | |
7a1b56a9 | 523 | lshift_double (l1, h1, count, prec, &s1l, &s1h, 0); |
524 | rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0); | |
525 | *lv = s1l | s2l; | |
526 | *hv = s1h | s2h; | |
2bc77e10 | 527 | } |
528 | ||
b572011e | 529 | /* Rotate the doubleword integer in L1, H1 left by COUNT places |
2bc77e10 | 530 | keeping only PREC bits of result. COUNT must be positive. |
b572011e | 531 | Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */ |
2bc77e10 | 532 | |
533 | void | |
534 | rrotate_double (l1, h1, count, prec, lv, hv) | |
a0c2c45b | 535 | unsigned HOST_WIDE_INT l1; |
536 | HOST_WIDE_INT h1, count; | |
537 | unsigned int prec; | |
538 | unsigned HOST_WIDE_INT *lv; | |
539 | HOST_WIDE_INT *hv; | |
2bc77e10 | 540 | { |
a0c2c45b | 541 | unsigned HOST_WIDE_INT s1l, s2l; |
542 | HOST_WIDE_INT s1h, s2h; | |
2bc77e10 | 543 | |
7a1b56a9 | 544 | count %= prec; |
545 | if (count < 0) | |
546 | count += prec; | |
2bc77e10 | 547 | |
7a1b56a9 | 548 | rshift_double (l1, h1, count, prec, &s1l, &s1h, 0); |
549 | lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0); | |
550 | *lv = s1l | s2l; | |
551 | *hv = s1h | s2h; | |
2bc77e10 | 552 | } |
553 | \f | |
b572011e | 554 | /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN |
2bc77e10 | 555 | for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM). |
556 | CODE is a tree code for a kind of division, one of | |
557 | TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR | |
558 | or EXACT_DIV_EXPR | |
20dd417a | 559 | It controls how the quotient is rounded to an integer. |
b9e999f0 | 560 | Return nonzero if the operation overflows. |
2bc77e10 | 561 | UNS nonzero says do unsigned division. */ |
562 | ||
15ca565e | 563 | int |
2bc77e10 | 564 | div_and_round_double (code, uns, |
565 | lnum_orig, hnum_orig, lden_orig, hden_orig, | |
566 | lquo, hquo, lrem, hrem) | |
567 | enum tree_code code; | |
568 | int uns; | |
a0c2c45b | 569 | unsigned HOST_WIDE_INT lnum_orig; /* num == numerator == dividend */ |
570 | HOST_WIDE_INT hnum_orig; | |
571 | unsigned HOST_WIDE_INT lden_orig; /* den == denominator == divisor */ | |
572 | HOST_WIDE_INT hden_orig; | |
573 | unsigned HOST_WIDE_INT *lquo, *lrem; | |
574 | HOST_WIDE_INT *hquo, *hrem; | |
2bc77e10 | 575 | { |
576 | int quo_neg = 0; | |
bd5b3bce | 577 | HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */ |
578 | HOST_WIDE_INT den[4], quo[4]; | |
19cb6b50 | 579 | int i, j; |
bd5b3bce | 580 | unsigned HOST_WIDE_INT work; |
a0c2c45b | 581 | unsigned HOST_WIDE_INT carry = 0; |
582 | unsigned HOST_WIDE_INT lnum = lnum_orig; | |
abd9ac9c | 583 | HOST_WIDE_INT hnum = hnum_orig; |
a0c2c45b | 584 | unsigned HOST_WIDE_INT lden = lden_orig; |
abd9ac9c | 585 | HOST_WIDE_INT hden = hden_orig; |
b9e999f0 | 586 | int overflow = 0; |
2bc77e10 | 587 | |
a0c2c45b | 588 | if (hden == 0 && lden == 0) |
ad87de1e | 589 | overflow = 1, lden = 1; |
2bc77e10 | 590 | |
591 | /* calculate quotient sign and convert operands to unsigned. */ | |
cc049fa3 | 592 | if (!uns) |
2bc77e10 | 593 | { |
b9e999f0 | 594 | if (hnum < 0) |
2bc77e10 | 595 | { |
596 | quo_neg = ~ quo_neg; | |
b9e999f0 | 597 | /* (minimum integer) / (-1) is the only overflow case. */ |
a0c2c45b | 598 | if (neg_double (lnum, hnum, &lnum, &hnum) |
599 | && ((HOST_WIDE_INT) lden & hden) == -1) | |
b9e999f0 | 600 | overflow = 1; |
2bc77e10 | 601 | } |
cc049fa3 | 602 | if (hden < 0) |
2bc77e10 | 603 | { |
604 | quo_neg = ~ quo_neg; | |
b9e999f0 | 605 | neg_double (lden, hden, &lden, &hden); |
2bc77e10 | 606 | } |
607 | } | |
608 | ||
609 | if (hnum == 0 && hden == 0) | |
610 | { /* single precision */ | |
611 | *hquo = *hrem = 0; | |
802ddb63 | 612 | /* This unsigned division rounds toward zero. */ |
a0c2c45b | 613 | *lquo = lnum / lden; |
2bc77e10 | 614 | goto finish_up; |
615 | } | |
616 | ||
617 | if (hnum == 0) | |
618 | { /* trivial case: dividend < divisor */ | |
619 | /* hden != 0 already checked. */ | |
620 | *hquo = *lquo = 0; | |
621 | *hrem = hnum; | |
622 | *lrem = lnum; | |
623 | goto finish_up; | |
624 | } | |
625 | ||
93d3b7de | 626 | memset ((char *) quo, 0, sizeof quo); |
2bc77e10 | 627 | |
93d3b7de | 628 | memset ((char *) num, 0, sizeof num); /* to zero 9th element */ |
629 | memset ((char *) den, 0, sizeof den); | |
2bc77e10 | 630 | |
cc049fa3 | 631 | encode (num, lnum, hnum); |
2bc77e10 | 632 | encode (den, lden, hden); |
633 | ||
bd5b3bce | 634 | /* Special code for when the divisor < BASE. */ |
a0c2c45b | 635 | if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE) |
bd5b3bce | 636 | { |
2bc77e10 | 637 | /* hnum != 0 already checked. */ |
bd5b3bce | 638 | for (i = 4 - 1; i >= 0; i--) |
2bc77e10 | 639 | { |
bd5b3bce | 640 | work = num[i] + carry * BASE; |
a0c2c45b | 641 | quo[i] = work / lden; |
642 | carry = work % lden; | |
2bc77e10 | 643 | } |
644 | } | |
bd5b3bce | 645 | else |
646 | { | |
647 | /* Full double precision division, | |
648 | with thanks to Don Knuth's "Seminumerical Algorithms". */ | |
a0c2c45b | 649 | int num_hi_sig, den_hi_sig; |
650 | unsigned HOST_WIDE_INT quo_est, scale; | |
2bc77e10 | 651 | |
6ef828f9 | 652 | /* Find the highest nonzero divisor digit. */ |
cc049fa3 | 653 | for (i = 4 - 1;; i--) |
654 | if (den[i] != 0) | |
655 | { | |
656 | den_hi_sig = i; | |
657 | break; | |
658 | } | |
bd5b3bce | 659 | |
a0c2c45b | 660 | /* Insure that the first digit of the divisor is at least BASE/2. |
661 | This is required by the quotient digit estimation algorithm. */ | |
2bc77e10 | 662 | |
a0c2c45b | 663 | scale = BASE / (den[den_hi_sig] + 1); |
664 | if (scale > 1) | |
665 | { /* scale divisor and dividend */ | |
666 | carry = 0; | |
667 | for (i = 0; i <= 4 - 1; i++) | |
668 | { | |
669 | work = (num[i] * scale) + carry; | |
670 | num[i] = LOWPART (work); | |
671 | carry = HIGHPART (work); | |
672 | } | |
2bc77e10 | 673 | |
a0c2c45b | 674 | num[4] = carry; |
675 | carry = 0; | |
676 | for (i = 0; i <= 4 - 1; i++) | |
677 | { | |
678 | work = (den[i] * scale) + carry; | |
679 | den[i] = LOWPART (work); | |
680 | carry = HIGHPART (work); | |
681 | if (den[i] != 0) den_hi_sig = i; | |
682 | } | |
683 | } | |
2bc77e10 | 684 | |
a0c2c45b | 685 | num_hi_sig = 4; |
2bc77e10 | 686 | |
a0c2c45b | 687 | /* Main loop */ |
688 | for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--) | |
2bc77e10 | 689 | { |
a0c2c45b | 690 | /* Guess the next quotient digit, quo_est, by dividing the first |
691 | two remaining dividend digits by the high order quotient digit. | |
692 | quo_est is never low and is at most 2 high. */ | |
693 | unsigned HOST_WIDE_INT tmp; | |
694 | ||
695 | num_hi_sig = i + den_hi_sig + 1; | |
696 | work = num[num_hi_sig] * BASE + num[num_hi_sig - 1]; | |
697 | if (num[num_hi_sig] != den[den_hi_sig]) | |
698 | quo_est = work / den[den_hi_sig]; | |
699 | else | |
700 | quo_est = BASE - 1; | |
2bc77e10 | 701 | |
1e625a2e | 702 | /* Refine quo_est so it's usually correct, and at most one high. */ |
a0c2c45b | 703 | tmp = work - quo_est * den[den_hi_sig]; |
704 | if (tmp < BASE | |
705 | && (den[den_hi_sig - 1] * quo_est | |
706 | > (tmp * BASE + num[num_hi_sig - 2]))) | |
707 | quo_est--; | |
2bc77e10 | 708 | |
a0c2c45b | 709 | /* Try QUO_EST as the quotient digit, by multiplying the |
710 | divisor by QUO_EST and subtracting from the remaining dividend. | |
711 | Keep in mind that QUO_EST is the I - 1st digit. */ | |
712 | ||
713 | carry = 0; | |
2bc77e10 | 714 | for (j = 0; j <= den_hi_sig; j++) |
715 | { | |
a0c2c45b | 716 | work = quo_est * den[j] + carry; |
bd5b3bce | 717 | carry = HIGHPART (work); |
a0c2c45b | 718 | work = num[i + j] - LOWPART (work); |
bd5b3bce | 719 | num[i + j] = LOWPART (work); |
a0c2c45b | 720 | carry += HIGHPART (work) != 0; |
2bc77e10 | 721 | } |
2bc77e10 | 722 | |
a0c2c45b | 723 | /* If quo_est was high by one, then num[i] went negative and |
724 | we need to correct things. */ | |
f9a532b0 | 725 | if (num[num_hi_sig] < (HOST_WIDE_INT) carry) |
a0c2c45b | 726 | { |
727 | quo_est--; | |
728 | carry = 0; /* add divisor back in */ | |
729 | for (j = 0; j <= den_hi_sig; j++) | |
730 | { | |
731 | work = num[i + j] + den[j] + carry; | |
732 | carry = HIGHPART (work); | |
733 | num[i + j] = LOWPART (work); | |
734 | } | |
735 | ||
736 | num [num_hi_sig] += carry; | |
737 | } | |
738 | ||
739 | /* Store the quotient digit. */ | |
740 | quo[i] = quo_est; | |
741 | } | |
2bc77e10 | 742 | } |
2bc77e10 | 743 | |
744 | decode (quo, lquo, hquo); | |
745 | ||
746 | finish_up: | |
747 | /* if result is negative, make it so. */ | |
748 | if (quo_neg) | |
749 | neg_double (*lquo, *hquo, lquo, hquo); | |
750 | ||
751 | /* compute trial remainder: rem = num - (quo * den) */ | |
752 | mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem); | |
753 | neg_double (*lrem, *hrem, lrem, hrem); | |
754 | add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem); | |
755 | ||
756 | switch (code) | |
757 | { | |
758 | case TRUNC_DIV_EXPR: | |
759 | case TRUNC_MOD_EXPR: /* round toward zero */ | |
760 | case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */ | |
b9e999f0 | 761 | return overflow; |
2bc77e10 | 762 | |
763 | case FLOOR_DIV_EXPR: | |
764 | case FLOOR_MOD_EXPR: /* round toward negative infinity */ | |
765 | if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */ | |
766 | { | |
767 | /* quo = quo - 1; */ | |
b572011e | 768 | add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, |
769 | lquo, hquo); | |
2bc77e10 | 770 | } |
a0c2c45b | 771 | else |
772 | return overflow; | |
2bc77e10 | 773 | break; |
774 | ||
775 | case CEIL_DIV_EXPR: | |
776 | case CEIL_MOD_EXPR: /* round toward positive infinity */ | |
777 | if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */ | |
778 | { | |
b572011e | 779 | add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0, |
780 | lquo, hquo); | |
2bc77e10 | 781 | } |
a0c2c45b | 782 | else |
783 | return overflow; | |
2bc77e10 | 784 | break; |
cc049fa3 | 785 | |
2bc77e10 | 786 | case ROUND_DIV_EXPR: |
787 | case ROUND_MOD_EXPR: /* round to closest integer */ | |
788 | { | |
a0c2c45b | 789 | unsigned HOST_WIDE_INT labs_rem = *lrem; |
790 | HOST_WIDE_INT habs_rem = *hrem; | |
791 | unsigned HOST_WIDE_INT labs_den = lden, ltwice; | |
792 | HOST_WIDE_INT habs_den = hden, htwice; | |
793 | ||
794 | /* Get absolute values */ | |
795 | if (*hrem < 0) | |
796 | neg_double (*lrem, *hrem, &labs_rem, &habs_rem); | |
797 | if (hden < 0) | |
798 | neg_double (lden, hden, &labs_den, &habs_den); | |
799 | ||
800 | /* If (2 * abs (lrem) >= abs (lden)) */ | |
b572011e | 801 | mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0, |
802 | labs_rem, habs_rem, <wice, &htwice); | |
a0c2c45b | 803 | |
b572011e | 804 | if (((unsigned HOST_WIDE_INT) habs_den |
805 | < (unsigned HOST_WIDE_INT) htwice) | |
806 | || (((unsigned HOST_WIDE_INT) habs_den | |
807 | == (unsigned HOST_WIDE_INT) htwice) | |
a0c2c45b | 808 | && (labs_den < ltwice))) |
2bc77e10 | 809 | { |
810 | if (*hquo < 0) | |
811 | /* quo = quo - 1; */ | |
b572011e | 812 | add_double (*lquo, *hquo, |
813 | (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo); | |
2bc77e10 | 814 | else |
815 | /* quo = quo + 1; */ | |
b572011e | 816 | add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0, |
817 | lquo, hquo); | |
2bc77e10 | 818 | } |
a0c2c45b | 819 | else |
820 | return overflow; | |
2bc77e10 | 821 | } |
822 | break; | |
823 | ||
824 | default: | |
825 | abort (); | |
826 | } | |
827 | ||
828 | /* compute true remainder: rem = num - (quo * den) */ | |
829 | mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem); | |
830 | neg_double (*lrem, *hrem, lrem, hrem); | |
831 | add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem); | |
b9e999f0 | 832 | return overflow; |
2bc77e10 | 833 | } |
834 | \f | |
23ec2d5e | 835 | /* Given T, an expression, return the negation of T. Allow for T to be |
836 | null, in which case return null. */ | |
2bc77e10 | 837 | |
23ec2d5e | 838 | static tree |
839 | negate_expr (t) | |
840 | tree t; | |
841 | { | |
842 | tree type; | |
843 | tree tem; | |
844 | ||
845 | if (t == 0) | |
846 | return 0; | |
847 | ||
848 | type = TREE_TYPE (t); | |
849 | STRIP_SIGN_NOPS (t); | |
850 | ||
851 | switch (TREE_CODE (t)) | |
852 | { | |
853 | case INTEGER_CST: | |
854 | case REAL_CST: | |
855 | if (! TREE_UNSIGNED (type) | |
856 | && 0 != (tem = fold (build1 (NEGATE_EXPR, type, t))) | |
857 | && ! TREE_OVERFLOW (tem)) | |
858 | return tem; | |
859 | break; | |
860 | ||
861 | case NEGATE_EXPR: | |
862 | return convert (type, TREE_OPERAND (t, 0)); | |
863 | ||
864 | case MINUS_EXPR: | |
865 | /* - (A - B) -> B - A */ | |
7f3be425 | 866 | if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations) |
23ec2d5e | 867 | return convert (type, |
868 | fold (build (MINUS_EXPR, TREE_TYPE (t), | |
869 | TREE_OPERAND (t, 1), | |
870 | TREE_OPERAND (t, 0)))); | |
871 | break; | |
872 | ||
873 | default: | |
874 | break; | |
875 | } | |
876 | ||
c5581a0b | 877 | return convert (type, fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t))); |
23ec2d5e | 878 | } |
879 | \f | |
880 | /* Split a tree IN into a constant, literal and variable parts that could be | |
881 | combined with CODE to make IN. "constant" means an expression with | |
882 | TREE_CONSTANT but that isn't an actual constant. CODE must be a | |
883 | commutative arithmetic operation. Store the constant part into *CONP, | |
b07ba9ff | 884 | the literal in *LITP and return the variable part. If a part isn't |
23ec2d5e | 885 | present, set it to null. If the tree does not decompose in this way, |
886 | return the entire tree as the variable part and the other parts as null. | |
887 | ||
888 | If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that | |
b07ba9ff | 889 | case, we negate an operand that was subtracted. Except if it is a |
890 | literal for which we use *MINUS_LITP instead. | |
891 | ||
892 | If NEGATE_P is true, we are negating all of IN, again except a literal | |
893 | for which we use *MINUS_LITP instead. | |
23ec2d5e | 894 | |
895 | If IN is itself a literal or constant, return it as appropriate. | |
896 | ||
897 | Note that we do not guarantee that any of the three values will be the | |
898 | same type as IN, but they will have the same signedness and mode. */ | |
899 | ||
900 | static tree | |
b07ba9ff | 901 | split_tree (in, code, conp, litp, minus_litp, negate_p) |
2bc77e10 | 902 | tree in; |
903 | enum tree_code code; | |
b07ba9ff | 904 | tree *conp, *litp, *minus_litp; |
23ec2d5e | 905 | int negate_p; |
2bc77e10 | 906 | { |
23ec2d5e | 907 | tree var = 0; |
908 | ||
2bc77e10 | 909 | *conp = 0; |
23ec2d5e | 910 | *litp = 0; |
b07ba9ff | 911 | *minus_litp = 0; |
23ec2d5e | 912 | |
6312a35e | 913 | /* Strip any conversions that don't change the machine mode or signedness. */ |
23ec2d5e | 914 | STRIP_SIGN_NOPS (in); |
915 | ||
916 | if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST) | |
917 | *litp = in; | |
23ec2d5e | 918 | else if (TREE_CODE (in) == code |
919 | || (! FLOAT_TYPE_P (TREE_TYPE (in)) | |
920 | /* We can associate addition and subtraction together (even | |
921 | though the C standard doesn't say so) for integers because | |
922 | the value is not affected. For reals, the value might be | |
923 | affected, so we can't. */ | |
924 | && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR) | |
925 | || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR)))) | |
926 | { | |
927 | tree op0 = TREE_OPERAND (in, 0); | |
928 | tree op1 = TREE_OPERAND (in, 1); | |
929 | int neg1_p = TREE_CODE (in) == MINUS_EXPR; | |
930 | int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0; | |
931 | ||
932 | /* First see if either of the operands is a literal, then a constant. */ | |
933 | if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST) | |
934 | *litp = op0, op0 = 0; | |
935 | else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST) | |
936 | *litp = op1, neg_litp_p = neg1_p, op1 = 0; | |
937 | ||
938 | if (op0 != 0 && TREE_CONSTANT (op0)) | |
939 | *conp = op0, op0 = 0; | |
940 | else if (op1 != 0 && TREE_CONSTANT (op1)) | |
941 | *conp = op1, neg_conp_p = neg1_p, op1 = 0; | |
942 | ||
943 | /* If we haven't dealt with either operand, this is not a case we can | |
6312a35e | 944 | decompose. Otherwise, VAR is either of the ones remaining, if any. */ |
23ec2d5e | 945 | if (op0 != 0 && op1 != 0) |
946 | var = in; | |
947 | else if (op0 != 0) | |
948 | var = op0; | |
949 | else | |
950 | var = op1, neg_var_p = neg1_p; | |
2bc77e10 | 951 | |
23ec2d5e | 952 | /* Now do any needed negations. */ |
b07ba9ff | 953 | if (neg_litp_p) |
954 | *minus_litp = *litp, *litp = 0; | |
955 | if (neg_conp_p) | |
956 | *conp = negate_expr (*conp); | |
957 | if (neg_var_p) | |
958 | var = negate_expr (var); | |
23ec2d5e | 959 | } |
8541c166 | 960 | else if (TREE_CONSTANT (in)) |
961 | *conp = in; | |
23ec2d5e | 962 | else |
963 | var = in; | |
964 | ||
965 | if (negate_p) | |
2bc77e10 | 966 | { |
b07ba9ff | 967 | if (*litp) |
968 | *minus_litp = *litp, *litp = 0; | |
969 | else if (*minus_litp) | |
970 | *litp = *minus_litp, *minus_litp = 0; | |
23ec2d5e | 971 | *conp = negate_expr (*conp); |
b07ba9ff | 972 | var = negate_expr (var); |
2bc77e10 | 973 | } |
23ec2d5e | 974 | |
975 | return var; | |
976 | } | |
977 | ||
978 | /* Re-associate trees split by the above function. T1 and T2 are either | |
979 | expressions to associate or null. Return the new expression, if any. If | |
b07ba9ff | 980 | we build an operation, do it in TYPE and with CODE. */ |
23ec2d5e | 981 | |
982 | static tree | |
983 | associate_trees (t1, t2, code, type) | |
984 | tree t1, t2; | |
985 | enum tree_code code; | |
986 | tree type; | |
987 | { | |
23ec2d5e | 988 | if (t1 == 0) |
989 | return t2; | |
990 | else if (t2 == 0) | |
991 | return t1; | |
992 | ||
23ec2d5e | 993 | /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't |
994 | try to fold this since we will have infinite recursion. But do | |
995 | deal with any NEGATE_EXPRs. */ | |
996 | if (TREE_CODE (t1) == code || TREE_CODE (t2) == code | |
997 | || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR) | |
998 | { | |
5a3fb4d3 | 999 | if (code == PLUS_EXPR) |
1000 | { | |
1001 | if (TREE_CODE (t1) == NEGATE_EXPR) | |
1002 | return build (MINUS_EXPR, type, convert (type, t2), | |
1003 | convert (type, TREE_OPERAND (t1, 0))); | |
1004 | else if (TREE_CODE (t2) == NEGATE_EXPR) | |
1005 | return build (MINUS_EXPR, type, convert (type, t1), | |
1006 | convert (type, TREE_OPERAND (t2, 0))); | |
1007 | } | |
1008 | return build (code, type, convert (type, t1), convert (type, t2)); | |
23ec2d5e | 1009 | } |
1010 | ||
1011 | return fold (build (code, type, convert (type, t1), convert (type, t2))); | |
2bc77e10 | 1012 | } |
1013 | \f | |
0dbd1c74 | 1014 | /* Combine two integer constants ARG1 and ARG2 under operation CODE |
2bc77e10 | 1015 | to produce a new constant. |
5485823f | 1016 | |
15d769aa | 1017 | If NOTRUNC is nonzero, do not truncate the result to fit the data type. */ |
2bc77e10 | 1018 | |
2bc77e10 | 1019 | static tree |
15d769aa | 1020 | int_const_binop (code, arg1, arg2, notrunc) |
2bc77e10 | 1021 | enum tree_code code; |
19cb6b50 | 1022 | tree arg1, arg2; |
15d769aa | 1023 | int notrunc; |
2bc77e10 | 1024 | { |
a0c2c45b | 1025 | unsigned HOST_WIDE_INT int1l, int2l; |
1026 | HOST_WIDE_INT int1h, int2h; | |
1027 | unsigned HOST_WIDE_INT low; | |
1028 | HOST_WIDE_INT hi; | |
1029 | unsigned HOST_WIDE_INT garbagel; | |
1030 | HOST_WIDE_INT garbageh; | |
19cb6b50 | 1031 | tree t; |
15d769aa | 1032 | tree type = TREE_TYPE (arg1); |
1033 | int uns = TREE_UNSIGNED (type); | |
1034 | int is_sizetype | |
1035 | = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)); | |
0dbd1c74 | 1036 | int overflow = 0; |
1037 | int no_overflow = 0; | |
8ea862a9 | 1038 | |
0dbd1c74 | 1039 | int1l = TREE_INT_CST_LOW (arg1); |
1040 | int1h = TREE_INT_CST_HIGH (arg1); | |
1041 | int2l = TREE_INT_CST_LOW (arg2); | |
1042 | int2h = TREE_INT_CST_HIGH (arg2); | |
1043 | ||
1044 | switch (code) | |
2bc77e10 | 1045 | { |
0dbd1c74 | 1046 | case BIT_IOR_EXPR: |
1047 | low = int1l | int2l, hi = int1h | int2h; | |
1048 | break; | |
2bc77e10 | 1049 | |
0dbd1c74 | 1050 | case BIT_XOR_EXPR: |
1051 | low = int1l ^ int2l, hi = int1h ^ int2h; | |
1052 | break; | |
2bc77e10 | 1053 | |
0dbd1c74 | 1054 | case BIT_AND_EXPR: |
1055 | low = int1l & int2l, hi = int1h & int2h; | |
1056 | break; | |
2bc77e10 | 1057 | |
0dbd1c74 | 1058 | case BIT_ANDTC_EXPR: |
1059 | low = int1l & ~int2l, hi = int1h & ~int2h; | |
1060 | break; | |
2bc77e10 | 1061 | |
0dbd1c74 | 1062 | case RSHIFT_EXPR: |
cc049fa3 | 1063 | int2l = -int2l; |
0dbd1c74 | 1064 | case LSHIFT_EXPR: |
1065 | /* It's unclear from the C standard whether shifts can overflow. | |
1066 | The following code ignores overflow; perhaps a C standard | |
1067 | interpretation ruling is needed. */ | |
15d769aa | 1068 | lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type), |
02e7a332 | 1069 | &low, &hi, !uns); |
0dbd1c74 | 1070 | no_overflow = 1; |
1071 | break; | |
2bc77e10 | 1072 | |
0dbd1c74 | 1073 | case RROTATE_EXPR: |
1074 | int2l = - int2l; | |
1075 | case LROTATE_EXPR: | |
15d769aa | 1076 | lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type), |
0dbd1c74 | 1077 | &low, &hi); |
1078 | break; | |
2bc77e10 | 1079 | |
0dbd1c74 | 1080 | case PLUS_EXPR: |
1081 | overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi); | |
1082 | break; | |
2bc77e10 | 1083 | |
0dbd1c74 | 1084 | case MINUS_EXPR: |
1085 | neg_double (int2l, int2h, &low, &hi); | |
1086 | add_double (int1l, int1h, low, hi, &low, &hi); | |
083a2b5e | 1087 | overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h); |
0dbd1c74 | 1088 | break; |
2bc77e10 | 1089 | |
0dbd1c74 | 1090 | case MULT_EXPR: |
1091 | overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi); | |
1092 | break; | |
2bc77e10 | 1093 | |
0dbd1c74 | 1094 | case TRUNC_DIV_EXPR: |
1095 | case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR: | |
1096 | case EXACT_DIV_EXPR: | |
1097 | /* This is a shortcut for a common special case. */ | |
a0c2c45b | 1098 | if (int2h == 0 && (HOST_WIDE_INT) int2l > 0 |
0dbd1c74 | 1099 | && ! TREE_CONSTANT_OVERFLOW (arg1) |
1100 | && ! TREE_CONSTANT_OVERFLOW (arg2) | |
a0c2c45b | 1101 | && int1h == 0 && (HOST_WIDE_INT) int1l >= 0) |
0dbd1c74 | 1102 | { |
1103 | if (code == CEIL_DIV_EXPR) | |
1104 | int1l += int2l - 1; | |
a0c2c45b | 1105 | |
0dbd1c74 | 1106 | low = int1l / int2l, hi = 0; |
2bc77e10 | 1107 | break; |
0dbd1c74 | 1108 | } |
2bc77e10 | 1109 | |
6312a35e | 1110 | /* ... fall through ... */ |
2bc77e10 | 1111 | |
cc049fa3 | 1112 | case ROUND_DIV_EXPR: |
0dbd1c74 | 1113 | if (int2h == 0 && int2l == 1) |
1114 | { | |
1115 | low = int1l, hi = int1h; | |
2bc77e10 | 1116 | break; |
0dbd1c74 | 1117 | } |
1118 | if (int1l == int2l && int1h == int2h | |
1119 | && ! (int1l == 0 && int1h == 0)) | |
1120 | { | |
1121 | low = 1, hi = 0; | |
c13e6dce | 1122 | break; |
0dbd1c74 | 1123 | } |
15d769aa | 1124 | overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h, |
0dbd1c74 | 1125 | &low, &hi, &garbagel, &garbageh); |
1126 | break; | |
c13e6dce | 1127 | |
0dbd1c74 | 1128 | case TRUNC_MOD_EXPR: |
1129 | case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR: | |
1130 | /* This is a shortcut for a common special case. */ | |
a0c2c45b | 1131 | if (int2h == 0 && (HOST_WIDE_INT) int2l > 0 |
0dbd1c74 | 1132 | && ! TREE_CONSTANT_OVERFLOW (arg1) |
1133 | && ! TREE_CONSTANT_OVERFLOW (arg2) | |
a0c2c45b | 1134 | && int1h == 0 && (HOST_WIDE_INT) int1l >= 0) |
0dbd1c74 | 1135 | { |
1136 | if (code == CEIL_MOD_EXPR) | |
1137 | int1l += int2l - 1; | |
1138 | low = int1l % int2l, hi = 0; | |
c13e6dce | 1139 | break; |
0dbd1c74 | 1140 | } |
c13e6dce | 1141 | |
6312a35e | 1142 | /* ... fall through ... */ |
0dbd1c74 | 1143 | |
cc049fa3 | 1144 | case ROUND_MOD_EXPR: |
0dbd1c74 | 1145 | overflow = div_and_round_double (code, uns, |
1146 | int1l, int1h, int2l, int2h, | |
1147 | &garbagel, &garbageh, &low, &hi); | |
1148 | break; | |
1149 | ||
1150 | case MIN_EXPR: | |
1151 | case MAX_EXPR: | |
1152 | if (uns) | |
083a2b5e | 1153 | low = (((unsigned HOST_WIDE_INT) int1h |
1154 | < (unsigned HOST_WIDE_INT) int2h) | |
1155 | || (((unsigned HOST_WIDE_INT) int1h | |
1156 | == (unsigned HOST_WIDE_INT) int2h) | |
a0c2c45b | 1157 | && int1l < int2l)); |
a3f1e3ec | 1158 | else |
a0c2c45b | 1159 | low = (int1h < int2h |
1160 | || (int1h == int2h && int1l < int2l)); | |
083a2b5e | 1161 | |
0dbd1c74 | 1162 | if (low == (code == MIN_EXPR)) |
1163 | low = int1l, hi = int1h; | |
1164 | else | |
1165 | low = int2l, hi = int2h; | |
1166 | break; | |
8ea862a9 | 1167 | |
0dbd1c74 | 1168 | default: |
1169 | abort (); | |
8ea862a9 | 1170 | } |
0dbd1c74 | 1171 | |
15d769aa | 1172 | /* If this is for a sizetype, can be represented as one (signed) |
1173 | HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches | |
1174 | constants. */ | |
1175 | if (is_sizetype | |
1176 | && ((hi == 0 && (HOST_WIDE_INT) low >= 0) | |
1177 | || (hi == -1 && (HOST_WIDE_INT) low < 0)) | |
708d4303 | 1178 | && overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2)) |
15d769aa | 1179 | return size_int_type_wide (low, type); |
0dbd1c74 | 1180 | else |
1181 | { | |
1182 | t = build_int_2 (low, hi); | |
1183 | TREE_TYPE (t) = TREE_TYPE (arg1); | |
1184 | } | |
1185 | ||
1186 | TREE_OVERFLOW (t) | |
15d769aa | 1187 | = ((notrunc |
1188 | ? (!uns || is_sizetype) && overflow | |
1189 | : (force_fit_type (t, (!uns || is_sizetype) && overflow) | |
1190 | && ! no_overflow)) | |
0dbd1c74 | 1191 | | TREE_OVERFLOW (arg1) |
1192 | | TREE_OVERFLOW (arg2)); | |
083a2b5e | 1193 | |
0dbd1c74 | 1194 | /* If we're doing a size calculation, unsigned arithmetic does overflow. |
1195 | So check if force_fit_type truncated the value. */ | |
15d769aa | 1196 | if (is_sizetype |
0dbd1c74 | 1197 | && ! TREE_OVERFLOW (t) |
1198 | && (TREE_INT_CST_HIGH (t) != hi | |
1199 | || TREE_INT_CST_LOW (t) != low)) | |
1200 | TREE_OVERFLOW (t) = 1; | |
083a2b5e | 1201 | |
0dbd1c74 | 1202 | TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t) |
1203 | | TREE_CONSTANT_OVERFLOW (arg1) | |
1204 | | TREE_CONSTANT_OVERFLOW (arg2)); | |
1205 | return t; | |
1206 | } | |
1207 | ||
083a2b5e | 1208 | /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new |
1209 | constant. We assume ARG1 and ARG2 have the same data type, or at least | |
1210 | are the same kind of constant and the same machine mode. | |
0dbd1c74 | 1211 | |
1212 | If NOTRUNC is nonzero, do not truncate the result to fit the data type. */ | |
1213 | ||
1214 | static tree | |
1215 | const_binop (code, arg1, arg2, notrunc) | |
1216 | enum tree_code code; | |
19cb6b50 | 1217 | tree arg1, arg2; |
0dbd1c74 | 1218 | int notrunc; |
1219 | { | |
cc049fa3 | 1220 | STRIP_NOPS (arg1); |
1221 | STRIP_NOPS (arg2); | |
0dbd1c74 | 1222 | |
1223 | if (TREE_CODE (arg1) == INTEGER_CST) | |
15d769aa | 1224 | return int_const_binop (code, arg1, arg2, notrunc); |
0dbd1c74 | 1225 | |
2bc77e10 | 1226 | if (TREE_CODE (arg1) == REAL_CST) |
1227 | { | |
9a24cfc6 | 1228 | REAL_VALUE_TYPE d1; |
1229 | REAL_VALUE_TYPE d2; | |
536f5fb1 | 1230 | REAL_VALUE_TYPE value; |
c0244247 | 1231 | tree t; |
2bc77e10 | 1232 | |
9a24cfc6 | 1233 | d1 = TREE_REAL_CST (arg1); |
1234 | d2 = TREE_REAL_CST (arg2); | |
9248d3e0 | 1235 | |
1236 | /* If either operand is a NaN, just return it. Otherwise, set up | |
1237 | for floating-point trap; we return an overflow. */ | |
1238 | if (REAL_VALUE_ISNAN (d1)) | |
1239 | return arg1; | |
1240 | else if (REAL_VALUE_ISNAN (d2)) | |
1241 | return arg2; | |
70192c5e | 1242 | |
536f5fb1 | 1243 | REAL_ARITHMETIC (value, code, d1, d2); |
cc049fa3 | 1244 | |
536f5fb1 | 1245 | t = build_real (TREE_TYPE (arg1), |
1246 | real_value_truncate (TYPE_MODE (TREE_TYPE (arg1)), | |
1247 | value)); | |
23fed9b2 | 1248 | |
1249 | TREE_OVERFLOW (t) | |
536f5fb1 | 1250 | = (force_fit_type (t, 0) |
23fed9b2 | 1251 | | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2)); |
1252 | TREE_CONSTANT_OVERFLOW (t) | |
1253 | = TREE_OVERFLOW (t) | |
1254 | | TREE_CONSTANT_OVERFLOW (arg1) | |
1255 | | TREE_CONSTANT_OVERFLOW (arg2); | |
c0244247 | 1256 | return t; |
2bc77e10 | 1257 | } |
2bc77e10 | 1258 | if (TREE_CODE (arg1) == COMPLEX_CST) |
1259 | { | |
19cb6b50 | 1260 | tree type = TREE_TYPE (arg1); |
1261 | tree r1 = TREE_REALPART (arg1); | |
1262 | tree i1 = TREE_IMAGPART (arg1); | |
1263 | tree r2 = TREE_REALPART (arg2); | |
1264 | tree i2 = TREE_IMAGPART (arg2); | |
1265 | tree t; | |
2bc77e10 | 1266 | |
1267 | switch (code) | |
1268 | { | |
1269 | case PLUS_EXPR: | |
5b2ade4d | 1270 | t = build_complex (type, |
1271 | const_binop (PLUS_EXPR, r1, r2, notrunc), | |
5485823f | 1272 | const_binop (PLUS_EXPR, i1, i2, notrunc)); |
2bc77e10 | 1273 | break; |
1274 | ||
1275 | case MINUS_EXPR: | |
5b2ade4d | 1276 | t = build_complex (type, |
1277 | const_binop (MINUS_EXPR, r1, r2, notrunc), | |
5485823f | 1278 | const_binop (MINUS_EXPR, i1, i2, notrunc)); |
2bc77e10 | 1279 | break; |
1280 | ||
1281 | case MULT_EXPR: | |
5b2ade4d | 1282 | t = build_complex (type, |
1283 | const_binop (MINUS_EXPR, | |
5485823f | 1284 | const_binop (MULT_EXPR, |
1285 | r1, r2, notrunc), | |
1286 | const_binop (MULT_EXPR, | |
1287 | i1, i2, notrunc), | |
1288 | notrunc), | |
2bc77e10 | 1289 | const_binop (PLUS_EXPR, |
5485823f | 1290 | const_binop (MULT_EXPR, |
1291 | r1, i2, notrunc), | |
1292 | const_binop (MULT_EXPR, | |
1293 | i1, r2, notrunc), | |
1294 | notrunc)); | |
2bc77e10 | 1295 | break; |
1296 | ||
1297 | case RDIV_EXPR: | |
1298 | { | |
19cb6b50 | 1299 | tree magsquared |
2bc77e10 | 1300 | = const_binop (PLUS_EXPR, |
5485823f | 1301 | const_binop (MULT_EXPR, r2, r2, notrunc), |
1302 | const_binop (MULT_EXPR, i2, i2, notrunc), | |
1303 | notrunc); | |
56d9b5a8 | 1304 | |
5b2ade4d | 1305 | t = build_complex (type, |
1306 | const_binop | |
1307 | (INTEGRAL_TYPE_P (TREE_TYPE (r1)) | |
1308 | ? TRUNC_DIV_EXPR : RDIV_EXPR, | |
1309 | const_binop (PLUS_EXPR, | |
1310 | const_binop (MULT_EXPR, r1, r2, | |
1311 | notrunc), | |
1312 | const_binop (MULT_EXPR, i1, i2, | |
1313 | notrunc), | |
1314 | notrunc), | |
1315 | magsquared, notrunc), | |
1316 | const_binop | |
1317 | (INTEGRAL_TYPE_P (TREE_TYPE (r1)) | |
1318 | ? TRUNC_DIV_EXPR : RDIV_EXPR, | |
1319 | const_binop (MINUS_EXPR, | |
1320 | const_binop (MULT_EXPR, i1, r2, | |
1321 | notrunc), | |
1322 | const_binop (MULT_EXPR, r1, i2, | |
1323 | notrunc), | |
1324 | notrunc), | |
1325 | magsquared, notrunc)); | |
2bc77e10 | 1326 | } |
1327 | break; | |
1328 | ||
1329 | default: | |
1330 | abort (); | |
1331 | } | |
2bc77e10 | 1332 | return t; |
1333 | } | |
1334 | return 0; | |
1335 | } | |
15d769aa | 1336 | |
1337 | /* These are the hash table functions for the hash table of INTEGER_CST | |
1338 | nodes of a sizetype. */ | |
1339 | ||
1340 | /* Return the hash code code X, an INTEGER_CST. */ | |
1341 | ||
1342 | static hashval_t | |
1343 | size_htab_hash (x) | |
1344 | const void *x; | |
1345 | { | |
1346 | tree t = (tree) x; | |
1347 | ||
1348 | return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t) | |
1349 | ^ (hashval_t) ((long) TREE_TYPE (t) >> 3) | |
1350 | ^ (TREE_OVERFLOW (t) << 20)); | |
1351 | } | |
1352 | ||
6ef828f9 | 1353 | /* Return nonzero if the value represented by *X (an INTEGER_CST tree node) |
15d769aa | 1354 | is the same as that given by *Y, which is the same. */ |
1355 | ||
1356 | static int | |
1357 | size_htab_eq (x, y) | |
1358 | const void *x; | |
1359 | const void *y; | |
1360 | { | |
1361 | tree xt = (tree) x; | |
1362 | tree yt = (tree) y; | |
1363 | ||
1364 | return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt) | |
1365 | && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt) | |
1366 | && TREE_TYPE (xt) == TREE_TYPE (yt) | |
1367 | && TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt)); | |
1368 | } | |
2bc77e10 | 1369 | \f |
b278476e | 1370 | /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT |
902de8ed | 1371 | bits are given by NUMBER and of the sizetype represented by KIND. */ |
083a2b5e | 1372 | |
902de8ed | 1373 | tree |
1374 | size_int_wide (number, kind) | |
1375 | HOST_WIDE_INT number; | |
1376 | enum size_type_kind kind; | |
1377 | { | |
1378 | return size_int_type_wide (number, sizetype_tab[(int) kind]); | |
1379 | } | |
1380 | ||
1381 | /* Likewise, but the desired type is specified explicitly. */ | |
2bc77e10 | 1382 | |
1f3233d1 | 1383 | static GTY (()) tree new_const; |
1384 | static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node))) | |
1385 | htab_t size_htab; | |
1386 | ||
2bc77e10 | 1387 | tree |
902de8ed | 1388 | size_int_type_wide (number, type) |
b278476e | 1389 | HOST_WIDE_INT number; |
902de8ed | 1390 | tree type; |
2bc77e10 | 1391 | { |
15d769aa | 1392 | PTR *slot; |
cc049fa3 | 1393 | |
15d769aa | 1394 | if (size_htab == 0) |
2bc77e10 | 1395 | { |
15d769aa | 1396 | size_htab = htab_create (1024, size_htab_hash, size_htab_eq, NULL); |
15d769aa | 1397 | new_const = make_node (INTEGER_CST); |
083a2b5e | 1398 | } |
1399 | ||
15d769aa | 1400 | /* Adjust NEW_CONST to be the constant we want. If it's already in the |
1401 | hash table, we return the value from the hash table. Otherwise, we | |
1402 | place that in the hash table and make a new node for the next time. */ | |
1403 | TREE_INT_CST_LOW (new_const) = number; | |
1404 | TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0; | |
1405 | TREE_TYPE (new_const) = type; | |
1406 | TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const) | |
1407 | = force_fit_type (new_const, 0); | |
1408 | ||
1409 | slot = htab_find_slot (size_htab, new_const, INSERT); | |
1410 | if (*slot == 0) | |
083a2b5e | 1411 | { |
15d769aa | 1412 | tree t = new_const; |
083a2b5e | 1413 | |
15d769aa | 1414 | *slot = (PTR) new_const; |
1415 | new_const = make_node (INTEGER_CST); | |
083a2b5e | 1416 | return t; |
2bc77e10 | 1417 | } |
15d769aa | 1418 | else |
1419 | return (tree) *slot; | |
2bc77e10 | 1420 | } |
1421 | ||
902de8ed | 1422 | /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE |
1423 | is a tree code. The type of the result is taken from the operands. | |
1424 | Both must be the same type integer type and it must be a size type. | |
2bc77e10 | 1425 | If the operands are constant, so is the result. */ |
1426 | ||
1427 | tree | |
1428 | size_binop (code, arg0, arg1) | |
1429 | enum tree_code code; | |
1430 | tree arg0, arg1; | |
1431 | { | |
902de8ed | 1432 | tree type = TREE_TYPE (arg0); |
1433 | ||
46fd7177 | 1434 | if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type) |
1435 | || type != TREE_TYPE (arg1)) | |
902de8ed | 1436 | abort (); |
1437 | ||
2bc77e10 | 1438 | /* Handle the special case of two integer constants faster. */ |
1439 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST) | |
1440 | { | |
1441 | /* And some specific cases even faster than that. */ | |
a7baffe5 | 1442 | if (code == PLUS_EXPR && integer_zerop (arg0)) |
2bc77e10 | 1443 | return arg1; |
a7baffe5 | 1444 | else if ((code == MINUS_EXPR || code == PLUS_EXPR) |
1445 | && integer_zerop (arg1)) | |
2bc77e10 | 1446 | return arg0; |
a7baffe5 | 1447 | else if (code == MULT_EXPR && integer_onep (arg0)) |
2bc77e10 | 1448 | return arg1; |
a7baffe5 | 1449 | |
2bc77e10 | 1450 | /* Handle general case of two integer constants. */ |
15d769aa | 1451 | return int_const_binop (code, arg0, arg1, 0); |
2bc77e10 | 1452 | } |
1453 | ||
1454 | if (arg0 == error_mark_node || arg1 == error_mark_node) | |
1455 | return error_mark_node; | |
1456 | ||
902de8ed | 1457 | return fold (build (code, type, arg0, arg1)); |
2bc77e10 | 1458 | } |
3fd3b688 | 1459 | |
902de8ed | 1460 | /* Given two values, either both of sizetype or both of bitsizetype, |
1461 | compute the difference between the two values. Return the value | |
1462 | in signed type corresponding to the type of the operands. */ | |
3fd3b688 | 1463 | |
1464 | tree | |
902de8ed | 1465 | size_diffop (arg0, arg1) |
3fd3b688 | 1466 | tree arg0, arg1; |
1467 | { | |
902de8ed | 1468 | tree type = TREE_TYPE (arg0); |
1469 | tree ctype; | |
3fd3b688 | 1470 | |
46fd7177 | 1471 | if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type) |
1472 | || type != TREE_TYPE (arg1)) | |
902de8ed | 1473 | abort (); |
3fd3b688 | 1474 | |
902de8ed | 1475 | /* If the type is already signed, just do the simple thing. */ |
1476 | if (! TREE_UNSIGNED (type)) | |
1477 | return size_binop (MINUS_EXPR, arg0, arg1); | |
1478 | ||
1479 | ctype = (type == bitsizetype || type == ubitsizetype | |
1480 | ? sbitsizetype : ssizetype); | |
1481 | ||
1482 | /* If either operand is not a constant, do the conversions to the signed | |
1483 | type and subtract. The hardware will do the right thing with any | |
1484 | overflow in the subtraction. */ | |
1485 | if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST) | |
1486 | return size_binop (MINUS_EXPR, convert (ctype, arg0), | |
1487 | convert (ctype, arg1)); | |
1488 | ||
1489 | /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE. | |
1490 | Otherwise, subtract the other way, convert to CTYPE (we know that can't | |
1491 | overflow) and negate (which can't either). Special-case a result | |
1492 | of zero while we're here. */ | |
1493 | if (tree_int_cst_equal (arg0, arg1)) | |
1494 | return convert (ctype, integer_zero_node); | |
1495 | else if (tree_int_cst_lt (arg1, arg0)) | |
1496 | return convert (ctype, size_binop (MINUS_EXPR, arg0, arg1)); | |
1497 | else | |
1498 | return size_binop (MINUS_EXPR, convert (ctype, integer_zero_node), | |
1499 | convert (ctype, size_binop (MINUS_EXPR, arg1, arg0))); | |
3fd3b688 | 1500 | } |
2bc77e10 | 1501 | \f |
70192c5e | 1502 | |
2bc77e10 | 1503 | /* Given T, a tree representing type conversion of ARG1, a constant, |
1504 | return a constant tree representing the result of conversion. */ | |
1505 | ||
1506 | static tree | |
1507 | fold_convert (t, arg1) | |
19cb6b50 | 1508 | tree t; |
1509 | tree arg1; | |
2bc77e10 | 1510 | { |
19cb6b50 | 1511 | tree type = TREE_TYPE (t); |
23fed9b2 | 1512 | int overflow = 0; |
2bc77e10 | 1513 | |
997d68fe | 1514 | if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type)) |
2bc77e10 | 1515 | { |
1516 | if (TREE_CODE (arg1) == INTEGER_CST) | |
1517 | { | |
ccf05f85 | 1518 | /* If we would build a constant wider than GCC supports, |
1519 | leave the conversion unfolded. */ | |
1520 | if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT) | |
1521 | return t; | |
1522 | ||
902de8ed | 1523 | /* If we are trying to make a sizetype for a small integer, use |
1524 | size_int to pick up cached types to reduce duplicate nodes. */ | |
4369f917 | 1525 | if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type) |
587f0f27 | 1526 | && !TREE_CONSTANT_OVERFLOW (arg1) |
02e7a332 | 1527 | && compare_tree_int (arg1, 10000) < 0) |
902de8ed | 1528 | return size_int_type_wide (TREE_INT_CST_LOW (arg1), type); |
1529 | ||
2bc77e10 | 1530 | /* Given an integer constant, make new constant with new type, |
1531 | appropriately sign-extended or truncated. */ | |
1532 | t = build_int_2 (TREE_INT_CST_LOW (arg1), | |
1533 | TREE_INT_CST_HIGH (arg1)); | |
1534 | TREE_TYPE (t) = type; | |
f55401f0 | 1535 | /* Indicate an overflow if (1) ARG1 already overflowed, |
f17f1965 | 1536 | or (2) force_fit_type indicates an overflow. |
1537 | Tell force_fit_type that an overflow has already occurred | |
271a8499 | 1538 | if ARG1 is a too-large unsigned value and T is signed. |
1539 | But don't indicate an overflow if converting a pointer. */ | |
f17f1965 | 1540 | TREE_OVERFLOW (t) |
997d68fe | 1541 | = ((force_fit_type (t, |
1542 | (TREE_INT_CST_HIGH (arg1) < 0 | |
dd1399ef | 1543 | && (TREE_UNSIGNED (type) |
997d68fe | 1544 | < TREE_UNSIGNED (TREE_TYPE (arg1))))) |
1545 | && ! POINTER_TYPE_P (TREE_TYPE (arg1))) | |
1546 | || TREE_OVERFLOW (arg1)); | |
f17f1965 | 1547 | TREE_CONSTANT_OVERFLOW (t) |
1548 | = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1); | |
2bc77e10 | 1549 | } |
2bc77e10 | 1550 | else if (TREE_CODE (arg1) == REAL_CST) |
1551 | { | |
a95b20e3 | 1552 | /* Don't initialize these, use assignments. |
1553 | Initialized local aggregates don't work on old compilers. */ | |
1554 | REAL_VALUE_TYPE x; | |
1555 | REAL_VALUE_TYPE l; | |
1556 | REAL_VALUE_TYPE u; | |
81b60185 | 1557 | tree type1 = TREE_TYPE (arg1); |
f52483b5 | 1558 | int no_upper_bound; |
a95b20e3 | 1559 | |
1560 | x = TREE_REAL_CST (arg1); | |
81b60185 | 1561 | l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type)); |
f52483b5 | 1562 | |
1563 | no_upper_bound = (TYPE_MAX_VALUE (type) == NULL); | |
1564 | if (!no_upper_bound) | |
1565 | u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type)); | |
1566 | ||
9658b5af | 1567 | /* See if X will be in range after truncation towards 0. |
1568 | To compensate for truncation, move the bounds away from 0, | |
1569 | but reject if X exactly equals the adjusted bounds. */ | |
9658b5af | 1570 | REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1); |
f52483b5 | 1571 | if (!no_upper_bound) |
1572 | REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1); | |
9248d3e0 | 1573 | /* If X is a NaN, use zero instead and show we have an overflow. |
1574 | Otherwise, range check. */ | |
1575 | if (REAL_VALUE_ISNAN (x)) | |
1576 | overflow = 1, x = dconst0; | |
f52483b5 | 1577 | else if (! (REAL_VALUES_LESS (l, x) |
1578 | && !no_upper_bound | |
1579 | && REAL_VALUES_LESS (x, u))) | |
23fed9b2 | 1580 | overflow = 1; |
1581 | ||
2bc77e10 | 1582 | { |
b572011e | 1583 | HOST_WIDE_INT low, high; |
9248d3e0 | 1584 | REAL_VALUE_TO_INT (&low, &high, x); |
2bc77e10 | 1585 | t = build_int_2 (low, high); |
1586 | } | |
2bc77e10 | 1587 | TREE_TYPE (t) = type; |
23fed9b2 | 1588 | TREE_OVERFLOW (t) |
1589 | = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow); | |
1590 | TREE_CONSTANT_OVERFLOW (t) | |
1591 | = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1); | |
2bc77e10 | 1592 | } |
2bc77e10 | 1593 | TREE_TYPE (t) = type; |
1594 | } | |
1595 | else if (TREE_CODE (type) == REAL_TYPE) | |
1596 | { | |
2bc77e10 | 1597 | if (TREE_CODE (arg1) == INTEGER_CST) |
1598 | return build_real_from_int_cst (type, arg1); | |
2bc77e10 | 1599 | if (TREE_CODE (arg1) == REAL_CST) |
c0244247 | 1600 | { |
9248d3e0 | 1601 | if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))) |
55a78ca1 | 1602 | { |
95ed90bf | 1603 | /* We make a copy of ARG1 so that we don't modify an |
1604 | existing constant tree. */ | |
1605 | t = copy_node (arg1); | |
1606 | TREE_TYPE (t) = type; | |
55a78ca1 | 1607 | return t; |
1608 | } | |
70192c5e | 1609 | |
536f5fb1 | 1610 | t = build_real (type, |
1611 | real_value_truncate (TYPE_MODE (type), | |
1612 | TREE_REAL_CST (arg1))); | |
23fed9b2 | 1613 | |
23fed9b2 | 1614 | TREE_OVERFLOW (t) |
536f5fb1 | 1615 | = TREE_OVERFLOW (arg1) | force_fit_type (t, 0); |
23fed9b2 | 1616 | TREE_CONSTANT_OVERFLOW (t) |
1617 | = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1); | |
c0244247 | 1618 | return t; |
1619 | } | |
2bc77e10 | 1620 | } |
1621 | TREE_CONSTANT (t) = 1; | |
1622 | return t; | |
1623 | } | |
1624 | \f | |
84791d69 | 1625 | /* Return an expr equal to X but certainly not valid as an lvalue. */ |
2bc77e10 | 1626 | |
1627 | tree | |
1628 | non_lvalue (x) | |
1629 | tree x; | |
1630 | { | |
1631 | tree result; | |
1632 | ||
1633 | /* These things are certainly not lvalues. */ | |
1634 | if (TREE_CODE (x) == NON_LVALUE_EXPR | |
1635 | || TREE_CODE (x) == INTEGER_CST | |
1636 | || TREE_CODE (x) == REAL_CST | |
1637 | || TREE_CODE (x) == STRING_CST | |
1638 | || TREE_CODE (x) == ADDR_EXPR) | |
84791d69 | 1639 | return x; |
2bc77e10 | 1640 | |
1641 | result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x); | |
1642 | TREE_CONSTANT (result) = TREE_CONSTANT (x); | |
1643 | return result; | |
1644 | } | |
56753054 | 1645 | |
b12c26dc | 1646 | /* Nonzero means lvalues are limited to those valid in pedantic ANSI C. |
1647 | Zero means allow extended lvalues. */ | |
1648 | ||
1649 | int pedantic_lvalues; | |
1650 | ||
56753054 | 1651 | /* When pedantic, return an expr equal to X but certainly not valid as a |
1652 | pedantic lvalue. Otherwise, return X. */ | |
1653 | ||
1654 | tree | |
1655 | pedantic_non_lvalue (x) | |
1656 | tree x; | |
1657 | { | |
b12c26dc | 1658 | if (pedantic_lvalues) |
56753054 | 1659 | return non_lvalue (x); |
1660 | else | |
1661 | return x; | |
1662 | } | |
e233264a | 1663 | \f |
1664 | /* Given a tree comparison code, return the code that is the logical inverse | |
1665 | of the given code. It is not safe to do this for floating-point | |
1666 | comparisons, except for NE_EXPR and EQ_EXPR. */ | |
2bc77e10 | 1667 | |
e233264a | 1668 | static enum tree_code |
1669 | invert_tree_comparison (code) | |
1670 | enum tree_code code; | |
1671 | { | |
1672 | switch (code) | |
1673 | { | |
1674 | case EQ_EXPR: | |
1675 | return NE_EXPR; | |
1676 | case NE_EXPR: | |
1677 | return EQ_EXPR; | |
1678 | case GT_EXPR: | |
1679 | return LE_EXPR; | |
1680 | case GE_EXPR: | |
1681 | return LT_EXPR; | |
1682 | case LT_EXPR: | |
1683 | return GE_EXPR; | |
1684 | case LE_EXPR: | |
1685 | return GT_EXPR; | |
1686 | default: | |
1687 | abort (); | |
1688 | } | |
1689 | } | |
1690 | ||
1691 | /* Similar, but return the comparison that results if the operands are | |
1692 | swapped. This is safe for floating-point. */ | |
1693 | ||
1694 | static enum tree_code | |
1695 | swap_tree_comparison (code) | |
1696 | enum tree_code code; | |
1697 | { | |
1698 | switch (code) | |
1699 | { | |
1700 | case EQ_EXPR: | |
1701 | case NE_EXPR: | |
1702 | return code; | |
1703 | case GT_EXPR: | |
1704 | return LT_EXPR; | |
1705 | case GE_EXPR: | |
1706 | return LE_EXPR; | |
1707 | case LT_EXPR: | |
1708 | return GT_EXPR; | |
1709 | case LE_EXPR: | |
1710 | return GE_EXPR; | |
1711 | default: | |
1712 | abort (); | |
1713 | } | |
1714 | } | |
8b94828f | 1715 | |
7835f163 | 1716 | |
1717 | /* Convert a comparison tree code from an enum tree_code representation | |
1718 | into a compcode bit-based encoding. This function is the inverse of | |
1719 | compcode_to_comparison. */ | |
1720 | ||
1721 | static int | |
1722 | comparison_to_compcode (code) | |
1723 | enum tree_code code; | |
1724 | { | |
1725 | switch (code) | |
1726 | { | |
1727 | case LT_EXPR: | |
1728 | return COMPCODE_LT; | |
1729 | case EQ_EXPR: | |
1730 | return COMPCODE_EQ; | |
1731 | case LE_EXPR: | |
1732 | return COMPCODE_LE; | |
1733 | case GT_EXPR: | |
1734 | return COMPCODE_GT; | |
1735 | case NE_EXPR: | |
1736 | return COMPCODE_NE; | |
1737 | case GE_EXPR: | |
1738 | return COMPCODE_GE; | |
1739 | default: | |
1740 | abort (); | |
1741 | } | |
1742 | } | |
1743 | ||
1744 | /* Convert a compcode bit-based encoding of a comparison operator back | |
1745 | to GCC's enum tree_code representation. This function is the | |
1746 | inverse of comparison_to_compcode. */ | |
1747 | ||
1748 | static enum tree_code | |
1749 | compcode_to_comparison (code) | |
1750 | int code; | |
1751 | { | |
1752 | switch (code) | |
1753 | { | |
1754 | case COMPCODE_LT: | |
1755 | return LT_EXPR; | |
1756 | case COMPCODE_EQ: | |
1757 | return EQ_EXPR; | |
1758 | case COMPCODE_LE: | |
1759 | return LE_EXPR; | |
1760 | case COMPCODE_GT: | |
1761 | return GT_EXPR; | |
1762 | case COMPCODE_NE: | |
1763 | return NE_EXPR; | |
1764 | case COMPCODE_GE: | |
1765 | return GE_EXPR; | |
1766 | default: | |
1767 | abort (); | |
1768 | } | |
1769 | } | |
1770 | ||
8b94828f | 1771 | /* Return nonzero if CODE is a tree code that represents a truth value. */ |
1772 | ||
1773 | static int | |
1774 | truth_value_p (code) | |
1775 | enum tree_code code; | |
1776 | { | |
1777 | return (TREE_CODE_CLASS (code) == '<' | |
1778 | || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR | |
1779 | || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR | |
1780 | || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR); | |
1781 | } | |
e233264a | 1782 | \f |
11acc1df | 1783 | /* Return nonzero if two operands are necessarily equal. |
6ef828f9 | 1784 | If ONLY_CONST is nonzero, only return nonzero for constants. |
11acc1df | 1785 | This function tests whether the operands are indistinguishable; |
1786 | it does not test whether they are equal using C's == operation. | |
1787 | The distinction is important for IEEE floating point, because | |
1788 | (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and | |
1789 | (2) two NaNs may be indistinguishable, but NaN!=NaN. */ | |
2bc77e10 | 1790 | |
1791 | int | |
1792 | operand_equal_p (arg0, arg1, only_const) | |
1793 | tree arg0, arg1; | |
1794 | int only_const; | |
1795 | { | |
1796 | /* If both types don't have the same signedness, then we can't consider | |
1797 | them equal. We must check this before the STRIP_NOPS calls | |
1798 | because they may change the signedness of the arguments. */ | |
1799 | if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1))) | |
1800 | return 0; | |
1801 | ||
1802 | STRIP_NOPS (arg0); | |
1803 | STRIP_NOPS (arg1); | |
1804 | ||
8faaadf1 | 1805 | if (TREE_CODE (arg0) != TREE_CODE (arg1) |
1806 | /* This is needed for conversions and for COMPONENT_REF. | |
1807 | Might as well play it safe and always test this. */ | |
6a4737bf | 1808 | || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK |
1809 | || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK | |
8faaadf1 | 1810 | || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1))) |
2bc77e10 | 1811 | return 0; |
1812 | ||
8faaadf1 | 1813 | /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal. |
1814 | We don't care about side effects in that case because the SAVE_EXPR | |
1815 | takes care of that for us. In all other cases, two expressions are | |
1816 | equal if they have no side effects. If we have two identical | |
1817 | expressions with side effects that should be treated the same due | |
1818 | to the only side effects being identical SAVE_EXPR's, that will | |
1819 | be detected in the recursive calls below. */ | |
1820 | if (arg0 == arg1 && ! only_const | |
1821 | && (TREE_CODE (arg0) == SAVE_EXPR | |
1822 | || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1)))) | |
2bc77e10 | 1823 | return 1; |
1824 | ||
8faaadf1 | 1825 | /* Next handle constant cases, those for which we can return 1 even |
1826 | if ONLY_CONST is set. */ | |
1827 | if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1)) | |
1828 | switch (TREE_CODE (arg0)) | |
1829 | { | |
1830 | case INTEGER_CST: | |
d3041b98 | 1831 | return (! TREE_CONSTANT_OVERFLOW (arg0) |
1832 | && ! TREE_CONSTANT_OVERFLOW (arg1) | |
a0c2c45b | 1833 | && tree_int_cst_equal (arg0, arg1)); |
8faaadf1 | 1834 | |
1835 | case REAL_CST: | |
d3041b98 | 1836 | return (! TREE_CONSTANT_OVERFLOW (arg0) |
1837 | && ! TREE_CONSTANT_OVERFLOW (arg1) | |
62aa7862 | 1838 | && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0), |
1839 | TREE_REAL_CST (arg1))); | |
8faaadf1 | 1840 | |
886cfd4f | 1841 | case VECTOR_CST: |
1842 | { | |
1843 | tree v1, v2; | |
1844 | ||
1845 | if (TREE_CONSTANT_OVERFLOW (arg0) | |
1846 | || TREE_CONSTANT_OVERFLOW (arg1)) | |
1847 | return 0; | |
1848 | ||
1849 | v1 = TREE_VECTOR_CST_ELTS (arg0); | |
1850 | v2 = TREE_VECTOR_CST_ELTS (arg1); | |
1851 | while (v1 && v2) | |
1852 | { | |
1853 | if (!operand_equal_p (v1, v2, only_const)) | |
1854 | return 0; | |
1855 | v1 = TREE_CHAIN (v1); | |
1856 | v2 = TREE_CHAIN (v2); | |
1857 | } | |
1858 | ||
1859 | return 1; | |
1860 | } | |
1861 | ||
8faaadf1 | 1862 | case COMPLEX_CST: |
1863 | return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1), | |
1864 | only_const) | |
1865 | && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1), | |
1866 | only_const)); | |
1867 | ||
1868 | case STRING_CST: | |
1869 | return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1) | |
6b918462 | 1870 | && ! memcmp (TREE_STRING_POINTER (arg0), |
8faaadf1 | 1871 | TREE_STRING_POINTER (arg1), |
1872 | TREE_STRING_LENGTH (arg0))); | |
1873 | ||
1874 | case ADDR_EXPR: | |
1875 | return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), | |
1876 | 0); | |
0dbd1c74 | 1877 | default: |
1878 | break; | |
8faaadf1 | 1879 | } |
2bc77e10 | 1880 | |
1881 | if (only_const) | |
1882 | return 0; | |
1883 | ||
2bc77e10 | 1884 | switch (TREE_CODE_CLASS (TREE_CODE (arg0))) |
1885 | { | |
1886 | case '1': | |
1887 | /* Two conversions are equal only if signedness and modes match. */ | |
1888 | if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR) | |
1889 | && (TREE_UNSIGNED (TREE_TYPE (arg0)) | |
1890 | != TREE_UNSIGNED (TREE_TYPE (arg1)))) | |
1891 | return 0; | |
1892 | ||
1893 | return operand_equal_p (TREE_OPERAND (arg0, 0), | |
1894 | TREE_OPERAND (arg1, 0), 0); | |
1895 | ||
1896 | case '<': | |
1897 | case '2': | |
8faaadf1 | 1898 | if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0) |
1899 | && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), | |
1900 | 0)) | |
1901 | return 1; | |
1902 | ||
1903 | /* For commutative ops, allow the other order. */ | |
1904 | return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR | |
1905 | || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR | |
1906 | || TREE_CODE (arg0) == BIT_IOR_EXPR | |
1907 | || TREE_CODE (arg0) == BIT_XOR_EXPR | |
1908 | || TREE_CODE (arg0) == BIT_AND_EXPR | |
1909 | || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR) | |
1910 | && operand_equal_p (TREE_OPERAND (arg0, 0), | |
1911 | TREE_OPERAND (arg1, 1), 0) | |
2bc77e10 | 1912 | && operand_equal_p (TREE_OPERAND (arg0, 1), |
8faaadf1 | 1913 | TREE_OPERAND (arg1, 0), 0)); |
2bc77e10 | 1914 | |
1915 | case 'r': | |
dbc71562 | 1916 | /* If either of the pointer (or reference) expressions we are dereferencing |
6312a35e | 1917 | contain a side effect, these cannot be equal. */ |
dbc71562 | 1918 | if (TREE_SIDE_EFFECTS (arg0) |
1919 | || TREE_SIDE_EFFECTS (arg1)) | |
1920 | return 0; | |
1921 | ||
2bc77e10 | 1922 | switch (TREE_CODE (arg0)) |
1923 | { | |
1924 | case INDIRECT_REF: | |
1925 | return operand_equal_p (TREE_OPERAND (arg0, 0), | |
1926 | TREE_OPERAND (arg1, 0), 0); | |
1927 | ||
1928 | case COMPONENT_REF: | |
1929 | case ARRAY_REF: | |
ba04d9d5 | 1930 | case ARRAY_RANGE_REF: |
2bc77e10 | 1931 | return (operand_equal_p (TREE_OPERAND (arg0, 0), |
1932 | TREE_OPERAND (arg1, 0), 0) | |
1933 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
1934 | TREE_OPERAND (arg1, 1), 0)); | |
1935 | ||
1936 | case BIT_FIELD_REF: | |
1937 | return (operand_equal_p (TREE_OPERAND (arg0, 0), | |
1938 | TREE_OPERAND (arg1, 0), 0) | |
1939 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
1940 | TREE_OPERAND (arg1, 1), 0) | |
1941 | && operand_equal_p (TREE_OPERAND (arg0, 2), | |
1942 | TREE_OPERAND (arg1, 2), 0)); | |
0dbd1c74 | 1943 | default: |
1944 | return 0; | |
2bc77e10 | 1945 | } |
1d322a97 | 1946 | |
1947 | case 'e': | |
1948 | if (TREE_CODE (arg0) == RTL_EXPR) | |
1949 | return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1)); | |
1950 | return 0; | |
cc049fa3 | 1951 | |
0dbd1c74 | 1952 | default: |
1953 | return 0; | |
2bc77e10 | 1954 | } |
2bc77e10 | 1955 | } |
e233264a | 1956 | \f |
1957 | /* Similar to operand_equal_p, but see if ARG0 might have been made by | |
cc049fa3 | 1958 | shorten_compare from ARG1 when ARG1 was being compared with OTHER. |
2bc77e10 | 1959 | |
2bc77e10 | 1960 | When in doubt, return 0. */ |
1961 | ||
cc049fa3 | 1962 | static int |
e233264a | 1963 | operand_equal_for_comparison_p (arg0, arg1, other) |
1964 | tree arg0, arg1; | |
1965 | tree other; | |
2bc77e10 | 1966 | { |
e233264a | 1967 | int unsignedp1, unsignedpo; |
df7caa7b | 1968 | tree primarg0, primarg1, primother; |
02e7a332 | 1969 | unsigned int correct_width; |
2bc77e10 | 1970 | |
e233264a | 1971 | if (operand_equal_p (arg0, arg1, 0)) |
2bc77e10 | 1972 | return 1; |
1973 | ||
154e6f12 | 1974 | if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0)) |
1975 | || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1))) | |
2bc77e10 | 1976 | return 0; |
1977 | ||
df7caa7b | 1978 | /* Discard any conversions that don't change the modes of ARG0 and ARG1 |
1979 | and see if the inner values are the same. This removes any | |
1980 | signedness comparison, which doesn't matter here. */ | |
1981 | primarg0 = arg0, primarg1 = arg1; | |
cc049fa3 | 1982 | STRIP_NOPS (primarg0); |
1983 | STRIP_NOPS (primarg1); | |
df7caa7b | 1984 | if (operand_equal_p (primarg0, primarg1, 0)) |
1985 | return 1; | |
1986 | ||
e233264a | 1987 | /* Duplicate what shorten_compare does to ARG1 and see if that gives the |
1988 | actual comparison operand, ARG0. | |
2bc77e10 | 1989 | |
e233264a | 1990 | First throw away any conversions to wider types |
2bc77e10 | 1991 | already present in the operands. */ |
2bc77e10 | 1992 | |
e233264a | 1993 | primarg1 = get_narrower (arg1, &unsignedp1); |
1994 | primother = get_narrower (other, &unsignedpo); | |
1995 | ||
1996 | correct_width = TYPE_PRECISION (TREE_TYPE (arg1)); | |
1997 | if (unsignedp1 == unsignedpo | |
1998 | && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width | |
1999 | && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width) | |
2bc77e10 | 2000 | { |
e233264a | 2001 | tree type = TREE_TYPE (arg0); |
2bc77e10 | 2002 | |
2003 | /* Make sure shorter operand is extended the right way | |
2004 | to match the longer operand. */ | |
4070745f | 2005 | primarg1 = convert ((*lang_hooks.types.signed_or_unsigned_type) |
2006 | (unsignedp1, TREE_TYPE (primarg1)), primarg1); | |
2bc77e10 | 2007 | |
e233264a | 2008 | if (operand_equal_p (arg0, convert (type, primarg1), 0)) |
2bc77e10 | 2009 | return 1; |
2010 | } | |
2011 | ||
2012 | return 0; | |
2013 | } | |
2014 | \f | |
eb2f80f3 | 2015 | /* See if ARG is an expression that is either a comparison or is performing |
e233264a | 2016 | arithmetic on comparisons. The comparisons must only be comparing |
2017 | two different values, which will be stored in *CVAL1 and *CVAL2; if | |
6ef828f9 | 2018 | they are nonzero it means that some operands have already been found. |
e233264a | 2019 | No variables may be used anywhere else in the expression except in the |
d0314131 | 2020 | comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around |
2021 | the expression and save_expr needs to be called with CVAL1 and CVAL2. | |
e233264a | 2022 | |
2023 | If this is true, return 1. Otherwise, return zero. */ | |
2024 | ||
2025 | static int | |
d0314131 | 2026 | twoval_comparison_p (arg, cval1, cval2, save_p) |
e233264a | 2027 | tree arg; |
2028 | tree *cval1, *cval2; | |
d0314131 | 2029 | int *save_p; |
e233264a | 2030 | { |
2031 | enum tree_code code = TREE_CODE (arg); | |
2032 | char class = TREE_CODE_CLASS (code); | |
2033 | ||
2034 | /* We can handle some of the 'e' cases here. */ | |
d0314131 | 2035 | if (class == 'e' && code == TRUTH_NOT_EXPR) |
e233264a | 2036 | class = '1'; |
2037 | else if (class == 'e' | |
2038 | && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR | |
2039 | || code == COMPOUND_EXPR)) | |
2040 | class = '2'; | |
8be91fe5 | 2041 | |
083a2b5e | 2042 | else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0 |
2043 | && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0))) | |
d0314131 | 2044 | { |
2045 | /* If we've already found a CVAL1 or CVAL2, this expression is | |
2046 | two complex to handle. */ | |
2047 | if (*cval1 || *cval2) | |
2048 | return 0; | |
2049 | ||
2050 | class = '1'; | |
2051 | *save_p = 1; | |
2052 | } | |
e233264a | 2053 | |
2054 | switch (class) | |
2055 | { | |
2056 | case '1': | |
d0314131 | 2057 | return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p); |
e233264a | 2058 | |
2059 | case '2': | |
d0314131 | 2060 | return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p) |
2061 | && twoval_comparison_p (TREE_OPERAND (arg, 1), | |
2062 | cval1, cval2, save_p)); | |
e233264a | 2063 | |
2064 | case 'c': | |
2065 | return 1; | |
2066 | ||
2067 | case 'e': | |
2068 | if (code == COND_EXPR) | |
d0314131 | 2069 | return (twoval_comparison_p (TREE_OPERAND (arg, 0), |
2070 | cval1, cval2, save_p) | |
2071 | && twoval_comparison_p (TREE_OPERAND (arg, 1), | |
2072 | cval1, cval2, save_p) | |
e233264a | 2073 | && twoval_comparison_p (TREE_OPERAND (arg, 2), |
d0314131 | 2074 | cval1, cval2, save_p)); |
e233264a | 2075 | return 0; |
cc049fa3 | 2076 | |
e233264a | 2077 | case '<': |
2078 | /* First see if we can handle the first operand, then the second. For | |
2079 | the second operand, we know *CVAL1 can't be zero. It must be that | |
2080 | one side of the comparison is each of the values; test for the | |
2081 | case where this isn't true by failing if the two operands | |
2082 | are the same. */ | |
2083 | ||
2084 | if (operand_equal_p (TREE_OPERAND (arg, 0), | |
2085 | TREE_OPERAND (arg, 1), 0)) | |
2086 | return 0; | |
2087 | ||
2088 | if (*cval1 == 0) | |
2089 | *cval1 = TREE_OPERAND (arg, 0); | |
2090 | else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0)) | |
2091 | ; | |
2092 | else if (*cval2 == 0) | |
2093 | *cval2 = TREE_OPERAND (arg, 0); | |
2094 | else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0)) | |
2095 | ; | |
2096 | else | |
2097 | return 0; | |
2098 | ||
2099 | if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0)) | |
2100 | ; | |
2101 | else if (*cval2 == 0) | |
2102 | *cval2 = TREE_OPERAND (arg, 1); | |
2103 | else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0)) | |
2104 | ; | |
2105 | else | |
2106 | return 0; | |
2107 | ||
2108 | return 1; | |
e233264a | 2109 | |
0dbd1c74 | 2110 | default: |
2111 | return 0; | |
2112 | } | |
e233264a | 2113 | } |
2114 | \f | |
2115 | /* ARG is a tree that is known to contain just arithmetic operations and | |
2116 | comparisons. Evaluate the operations in the tree substituting NEW0 for | |
eb2f80f3 | 2117 | any occurrence of OLD0 as an operand of a comparison and likewise for |
e233264a | 2118 | NEW1 and OLD1. */ |
2119 | ||
2120 | static tree | |
2121 | eval_subst (arg, old0, new0, old1, new1) | |
2122 | tree arg; | |
2123 | tree old0, new0, old1, new1; | |
2124 | { | |
2125 | tree type = TREE_TYPE (arg); | |
2126 | enum tree_code code = TREE_CODE (arg); | |
2127 | char class = TREE_CODE_CLASS (code); | |
2128 | ||
2129 | /* We can handle some of the 'e' cases here. */ | |
2130 | if (class == 'e' && code == TRUTH_NOT_EXPR) | |
2131 | class = '1'; | |
2132 | else if (class == 'e' | |
2133 | && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)) | |
2134 | class = '2'; | |
2135 | ||
2136 | switch (class) | |
2137 | { | |
2138 | case '1': | |
2139 | return fold (build1 (code, type, | |
2140 | eval_subst (TREE_OPERAND (arg, 0), | |
2141 | old0, new0, old1, new1))); | |
2142 | ||
2143 | case '2': | |
2144 | return fold (build (code, type, | |
2145 | eval_subst (TREE_OPERAND (arg, 0), | |
2146 | old0, new0, old1, new1), | |
2147 | eval_subst (TREE_OPERAND (arg, 1), | |
2148 | old0, new0, old1, new1))); | |
2149 | ||
2150 | case 'e': | |
2151 | switch (code) | |
2152 | { | |
2153 | case SAVE_EXPR: | |
2154 | return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1); | |
2155 | ||
2156 | case COMPOUND_EXPR: | |
2157 | return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1); | |
2158 | ||
2159 | case COND_EXPR: | |
2160 | return fold (build (code, type, | |
2161 | eval_subst (TREE_OPERAND (arg, 0), | |
2162 | old0, new0, old1, new1), | |
2163 | eval_subst (TREE_OPERAND (arg, 1), | |
2164 | old0, new0, old1, new1), | |
2165 | eval_subst (TREE_OPERAND (arg, 2), | |
2166 | old0, new0, old1, new1))); | |
0dbd1c74 | 2167 | default: |
2168 | break; | |
e233264a | 2169 | } |
ea727b1a | 2170 | /* fall through - ??? */ |
e233264a | 2171 | |
2172 | case '<': | |
2173 | { | |
2174 | tree arg0 = TREE_OPERAND (arg, 0); | |
2175 | tree arg1 = TREE_OPERAND (arg, 1); | |
2176 | ||
2177 | /* We need to check both for exact equality and tree equality. The | |
2178 | former will be true if the operand has a side-effect. In that | |
2179 | case, we know the operand occurred exactly once. */ | |
2180 | ||
2181 | if (arg0 == old0 || operand_equal_p (arg0, old0, 0)) | |
2182 | arg0 = new0; | |
2183 | else if (arg0 == old1 || operand_equal_p (arg0, old1, 0)) | |
2184 | arg0 = new1; | |
2185 | ||
2186 | if (arg1 == old0 || operand_equal_p (arg1, old0, 0)) | |
2187 | arg1 = new0; | |
2188 | else if (arg1 == old1 || operand_equal_p (arg1, old1, 0)) | |
2189 | arg1 = new1; | |
2190 | ||
2191 | return fold (build (code, type, arg0, arg1)); | |
2192 | } | |
e233264a | 2193 | |
0dbd1c74 | 2194 | default: |
2195 | return arg; | |
2196 | } | |
e233264a | 2197 | } |
2198 | \f | |
2bc77e10 | 2199 | /* Return a tree for the case when the result of an expression is RESULT |
2200 | converted to TYPE and OMITTED was previously an operand of the expression | |
2201 | but is now not needed (e.g., we folded OMITTED * 0). | |
2202 | ||
2203 | If OMITTED has side effects, we must evaluate it. Otherwise, just do | |
2204 | the conversion of RESULT to TYPE. */ | |
2205 | ||
2206 | static tree | |
2207 | omit_one_operand (type, result, omitted) | |
2208 | tree type, result, omitted; | |
2209 | { | |
2210 | tree t = convert (type, result); | |
2211 | ||
2212 | if (TREE_SIDE_EFFECTS (omitted)) | |
2213 | return build (COMPOUND_EXPR, type, omitted, t); | |
2214 | ||
c3ce5d04 | 2215 | return non_lvalue (t); |
2bc77e10 | 2216 | } |
6df5edfa | 2217 | |
2218 | /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */ | |
2219 | ||
2220 | static tree | |
2221 | pedantic_omit_one_operand (type, result, omitted) | |
2222 | tree type, result, omitted; | |
2223 | { | |
2224 | tree t = convert (type, result); | |
2225 | ||
2226 | if (TREE_SIDE_EFFECTS (omitted)) | |
2227 | return build (COMPOUND_EXPR, type, omitted, t); | |
2228 | ||
2229 | return pedantic_non_lvalue (t); | |
2230 | } | |
2bc77e10 | 2231 | \f |
46b0e007 | 2232 | /* Return a simplified tree node for the truth-negation of ARG. This |
2233 | never alters ARG itself. We assume that ARG is an operation that | |
2bc77e10 | 2234 | returns a truth value (0 or 1). */ |
2235 | ||
2236 | tree | |
2237 | invert_truthvalue (arg) | |
2238 | tree arg; | |
2239 | { | |
2240 | tree type = TREE_TYPE (arg); | |
e233264a | 2241 | enum tree_code code = TREE_CODE (arg); |
2bc77e10 | 2242 | |
c34cc7e5 | 2243 | if (code == ERROR_MARK) |
2244 | return arg; | |
2245 | ||
e233264a | 2246 | /* If this is a comparison, we can simply invert it, except for |
2247 | floating-point non-equality comparisons, in which case we just | |
2248 | enclose a TRUTH_NOT_EXPR around what we have. */ | |
2bc77e10 | 2249 | |
e233264a | 2250 | if (TREE_CODE_CLASS (code) == '<') |
2bc77e10 | 2251 | { |
780a4395 | 2252 | if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0))) |
7f3be425 | 2253 | && !flag_unsafe_math_optimizations |
d3371fcd | 2254 | && code != NE_EXPR |
7f3be425 | 2255 | && code != EQ_EXPR) |
e233264a | 2256 | return build1 (TRUTH_NOT_EXPR, type, arg); |
2257 | else | |
c26f1a45 | 2258 | return build (invert_tree_comparison (code), type, |
46b0e007 | 2259 | TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1)); |
e233264a | 2260 | } |
2bc77e10 | 2261 | |
e233264a | 2262 | switch (code) |
2263 | { | |
2bc77e10 | 2264 | case INTEGER_CST: |
a0c2c45b | 2265 | return convert (type, build_int_2 (integer_zerop (arg), 0)); |
2bc77e10 | 2266 | |
2267 | case TRUTH_AND_EXPR: | |
2268 | return build (TRUTH_OR_EXPR, type, | |
2269 | invert_truthvalue (TREE_OPERAND (arg, 0)), | |
2270 | invert_truthvalue (TREE_OPERAND (arg, 1))); | |
2271 | ||
2272 | case TRUTH_OR_EXPR: | |
2273 | return build (TRUTH_AND_EXPR, type, | |
2274 | invert_truthvalue (TREE_OPERAND (arg, 0)), | |
2275 | invert_truthvalue (TREE_OPERAND (arg, 1))); | |
2276 | ||
9a7b73a1 | 2277 | case TRUTH_XOR_EXPR: |
2278 | /* Here we can invert either operand. We invert the first operand | |
2279 | unless the second operand is a TRUTH_NOT_EXPR in which case our | |
2280 | result is the XOR of the first operand with the inside of the | |
2281 | negation of the second operand. */ | |
2282 | ||
2283 | if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR) | |
2284 | return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0), | |
2285 | TREE_OPERAND (TREE_OPERAND (arg, 1), 0)); | |
2286 | else | |
2287 | return build (TRUTH_XOR_EXPR, type, | |
2288 | invert_truthvalue (TREE_OPERAND (arg, 0)), | |
2289 | TREE_OPERAND (arg, 1)); | |
2290 | ||
2bc77e10 | 2291 | case TRUTH_ANDIF_EXPR: |
2292 | return build (TRUTH_ORIF_EXPR, type, | |
2293 | invert_truthvalue (TREE_OPERAND (arg, 0)), | |
2294 | invert_truthvalue (TREE_OPERAND (arg, 1))); | |
2295 | ||
2296 | case TRUTH_ORIF_EXPR: | |
2297 | return build (TRUTH_ANDIF_EXPR, type, | |
2298 | invert_truthvalue (TREE_OPERAND (arg, 0)), | |
2299 | invert_truthvalue (TREE_OPERAND (arg, 1))); | |
2300 | ||
2301 | case TRUTH_NOT_EXPR: | |
2302 | return TREE_OPERAND (arg, 0); | |
2303 | ||
2304 | case COND_EXPR: | |
2305 | return build (COND_EXPR, type, TREE_OPERAND (arg, 0), | |
2306 | invert_truthvalue (TREE_OPERAND (arg, 1)), | |
2307 | invert_truthvalue (TREE_OPERAND (arg, 2))); | |
2308 | ||
3139f3ce | 2309 | case COMPOUND_EXPR: |
2310 | return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0), | |
2311 | invert_truthvalue (TREE_OPERAND (arg, 1))); | |
2312 | ||
155b05dc | 2313 | case WITH_RECORD_EXPR: |
2314 | return build (WITH_RECORD_EXPR, type, | |
2315 | invert_truthvalue (TREE_OPERAND (arg, 0)), | |
2316 | TREE_OPERAND (arg, 1)); | |
2317 | ||
2bc77e10 | 2318 | case NON_LVALUE_EXPR: |
2319 | return invert_truthvalue (TREE_OPERAND (arg, 0)); | |
2320 | ||
2321 | case NOP_EXPR: | |
2322 | case CONVERT_EXPR: | |
2323 | case FLOAT_EXPR: | |
2324 | return build1 (TREE_CODE (arg), type, | |
2325 | invert_truthvalue (TREE_OPERAND (arg, 0))); | |
2326 | ||
2327 | case BIT_AND_EXPR: | |
c35387e1 | 2328 | if (!integer_onep (TREE_OPERAND (arg, 1))) |
2329 | break; | |
2bc77e10 | 2330 | return build (EQ_EXPR, type, arg, convert (type, integer_zero_node)); |
2bc77e10 | 2331 | |
468d693c | 2332 | case SAVE_EXPR: |
2333 | return build1 (TRUTH_NOT_EXPR, type, arg); | |
f33c3a83 | 2334 | |
2335 | case CLEANUP_POINT_EXPR: | |
2336 | return build1 (CLEANUP_POINT_EXPR, type, | |
2337 | invert_truthvalue (TREE_OPERAND (arg, 0))); | |
0dbd1c74 | 2338 | |
2339 | default: | |
2340 | break; | |
c35387e1 | 2341 | } |
2342 | if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE) | |
468d693c | 2343 | abort (); |
c35387e1 | 2344 | return build1 (TRUTH_NOT_EXPR, type, arg); |
2bc77e10 | 2345 | } |
2346 | ||
2347 | /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both | |
2348 | operands are another bit-wise operation with a common input. If so, | |
2349 | distribute the bit operations to save an operation and possibly two if | |
2350 | constants are involved. For example, convert | |
2351 | (A | B) & (A | C) into A | (B & C) | |
2352 | Further simplification will occur if B and C are constants. | |
2353 | ||
2354 | If this optimization cannot be done, 0 will be returned. */ | |
2355 | ||
2356 | static tree | |
2357 | distribute_bit_expr (code, type, arg0, arg1) | |
2358 | enum tree_code code; | |
2359 | tree type; | |
2360 | tree arg0, arg1; | |
2361 | { | |
2362 | tree common; | |
2363 | tree left, right; | |
2364 | ||
2365 | if (TREE_CODE (arg0) != TREE_CODE (arg1) | |
2366 | || TREE_CODE (arg0) == code | |
5b1de181 | 2367 | || (TREE_CODE (arg0) != BIT_AND_EXPR |
2368 | && TREE_CODE (arg0) != BIT_IOR_EXPR)) | |
2bc77e10 | 2369 | return 0; |
2370 | ||
2371 | if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)) | |
2372 | { | |
2373 | common = TREE_OPERAND (arg0, 0); | |
2374 | left = TREE_OPERAND (arg0, 1); | |
2375 | right = TREE_OPERAND (arg1, 1); | |
2376 | } | |
2377 | else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0)) | |
2378 | { | |
2379 | common = TREE_OPERAND (arg0, 0); | |
2380 | left = TREE_OPERAND (arg0, 1); | |
2381 | right = TREE_OPERAND (arg1, 0); | |
2382 | } | |
2383 | else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0)) | |
2384 | { | |
2385 | common = TREE_OPERAND (arg0, 1); | |
2386 | left = TREE_OPERAND (arg0, 0); | |
2387 | right = TREE_OPERAND (arg1, 1); | |
2388 | } | |
2389 | else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0)) | |
2390 | { | |
2391 | common = TREE_OPERAND (arg0, 1); | |
2392 | left = TREE_OPERAND (arg0, 0); | |
2393 | right = TREE_OPERAND (arg1, 0); | |
2394 | } | |
2395 | else | |
2396 | return 0; | |
2397 | ||
2398 | return fold (build (TREE_CODE (arg0), type, common, | |
2399 | fold (build (code, type, left, right)))); | |
2400 | } | |
2401 | \f | |
2402 | /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER | |
6ef828f9 | 2403 | starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */ |
2bc77e10 | 2404 | |
2405 | static tree | |
2406 | make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp) | |
2407 | tree inner; | |
2408 | tree type; | |
2409 | int bitsize, bitpos; | |
2410 | int unsignedp; | |
2411 | { | |
2412 | tree result = build (BIT_FIELD_REF, type, inner, | |
b278476e | 2413 | size_int (bitsize), bitsize_int (bitpos)); |
2bc77e10 | 2414 | |
2415 | TREE_UNSIGNED (result) = unsignedp; | |
2416 | ||
2417 | return result; | |
2418 | } | |
2419 | ||
2420 | /* Optimize a bit-field compare. | |
2421 | ||
2422 | There are two cases: First is a compare against a constant and the | |
2423 | second is a comparison of two items where the fields are at the same | |
2424 | bit position relative to the start of a chunk (byte, halfword, word) | |
2425 | large enough to contain it. In these cases we can avoid the shift | |
2426 | implicit in bitfield extractions. | |
2427 | ||
2428 | For constants, we emit a compare of the shifted constant with the | |
2429 | BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being | |
2430 | compared. For two fields at the same position, we do the ANDs with the | |
2431 | similar mask and compare the result of the ANDs. | |
2432 | ||
2433 | CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR. | |
2434 | COMPARE_TYPE is the type of the comparison, and LHS and RHS | |
2435 | are the left and right operands of the comparison, respectively. | |
2436 | ||
4bbea254 | 2437 | If the optimization described above can be done, we return the resulting |
2bc77e10 | 2438 | tree. Otherwise we return zero. */ |
2439 | ||
2440 | static tree | |
2441 | optimize_bit_field_compare (code, compare_type, lhs, rhs) | |
2442 | enum tree_code code; | |
2443 | tree compare_type; | |
2444 | tree lhs, rhs; | |
2445 | { | |
02e7a332 | 2446 | HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize; |
2bc77e10 | 2447 | tree type = TREE_TYPE (lhs); |
2448 | tree signed_type, unsigned_type; | |
2449 | int const_p = TREE_CODE (rhs) == INTEGER_CST; | |
4d1060a2 | 2450 | enum machine_mode lmode, rmode, nmode; |
2bc77e10 | 2451 | int lunsignedp, runsignedp; |
2452 | int lvolatilep = 0, rvolatilep = 0; | |
93b6a460 | 2453 | tree linner, rinner = NULL_TREE; |
2bc77e10 | 2454 | tree mask; |
bbfbdece | 2455 | tree offset; |
2bc77e10 | 2456 | |
2457 | /* Get all the information about the extractions being done. If the bit size | |
2458 | if the same as the size of the underlying object, we aren't doing an | |
155b05dc | 2459 | extraction at all and so can do nothing. We also don't want to |
2460 | do anything if the inner expression is a PLACEHOLDER_EXPR since we | |
2461 | then will no longer be able to replace it. */ | |
bbfbdece | 2462 | linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode, |
2b96c5f6 | 2463 | &lunsignedp, &lvolatilep); |
f73497ef | 2464 | if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0 |
155b05dc | 2465 | || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR) |
2bc77e10 | 2466 | return 0; |
2467 | ||
2468 | if (!const_p) | |
2469 | { | |
2470 | /* If this is not a constant, we can only do something if bit positions, | |
1e625a2e | 2471 | sizes, and signedness are the same. */ |
417d3458 | 2472 | rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode, |
2b96c5f6 | 2473 | &runsignedp, &rvolatilep); |
2bc77e10 | 2474 | |
f73497ef | 2475 | if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize |
155b05dc | 2476 | || lunsignedp != runsignedp || offset != 0 |
2477 | || TREE_CODE (rinner) == PLACEHOLDER_EXPR) | |
2bc77e10 | 2478 | return 0; |
2479 | } | |
2480 | ||
2481 | /* See if we can find a mode to refer to this field. We should be able to, | |
2482 | but fail if we can't. */ | |
4d1060a2 | 2483 | nmode = get_best_mode (lbitsize, lbitpos, |
2484 | const_p ? TYPE_ALIGN (TREE_TYPE (linner)) | |
2485 | : MIN (TYPE_ALIGN (TREE_TYPE (linner)), | |
2486 | TYPE_ALIGN (TREE_TYPE (rinner))), | |
2487 | word_mode, lvolatilep || rvolatilep); | |
2488 | if (nmode == VOIDmode) | |
2bc77e10 | 2489 | return 0; |
2490 | ||
2491 | /* Set signed and unsigned types of the precision of this mode for the | |
2492 | shifts below. */ | |
771d21fa | 2493 | signed_type = (*lang_hooks.types.type_for_mode) (nmode, 0); |
2494 | unsigned_type = (*lang_hooks.types.type_for_mode) (nmode, 1); | |
2bc77e10 | 2495 | |
2bc77e10 | 2496 | /* Compute the bit position and size for the new reference and our offset |
2497 | within it. If the new reference is the same size as the original, we | |
2498 | won't optimize anything, so return zero. */ | |
4d1060a2 | 2499 | nbitsize = GET_MODE_BITSIZE (nmode); |
2500 | nbitpos = lbitpos & ~ (nbitsize - 1); | |
2501 | lbitpos -= nbitpos; | |
2502 | if (nbitsize == lbitsize) | |
2bc77e10 | 2503 | return 0; |
2504 | ||
51356f86 | 2505 | if (BYTES_BIG_ENDIAN) |
4d1060a2 | 2506 | lbitpos = nbitsize - lbitsize - lbitpos; |
2bc77e10 | 2507 | |
2508 | /* Make the mask to be used against the extracted field. */ | |
52a49c7c | 2509 | mask = build_int_2 (~0, ~0); |
2510 | TREE_TYPE (mask) = unsigned_type; | |
86814797 | 2511 | force_fit_type (mask, 0); |
52a49c7c | 2512 | mask = convert (unsigned_type, mask); |
4d1060a2 | 2513 | mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0); |
2bc77e10 | 2514 | mask = const_binop (RSHIFT_EXPR, mask, |
4d1060a2 | 2515 | size_int (nbitsize - lbitsize - lbitpos), 0); |
2bc77e10 | 2516 | |
2517 | if (! const_p) | |
2518 | /* If not comparing with constant, just rework the comparison | |
2519 | and return. */ | |
2520 | return build (code, compare_type, | |
66716a97 | 2521 | build (BIT_AND_EXPR, unsigned_type, |
2522 | make_bit_field_ref (linner, unsigned_type, | |
4d1060a2 | 2523 | nbitsize, nbitpos, 1), |
2bc77e10 | 2524 | mask), |
66716a97 | 2525 | build (BIT_AND_EXPR, unsigned_type, |
2526 | make_bit_field_ref (rinner, unsigned_type, | |
4d1060a2 | 2527 | nbitsize, nbitpos, 1), |
2bc77e10 | 2528 | mask)); |
2529 | ||
2530 | /* Otherwise, we are handling the constant case. See if the constant is too | |
2531 | big for the field. Warn and return a tree of for 0 (false) if so. We do | |
2532 | this not only for its own sake, but to avoid having to test for this | |
2533 | error case below. If we didn't, we might generate wrong code. | |
2534 | ||
2535 | For unsigned fields, the constant shifted right by the field length should | |
cc049fa3 | 2536 | be all zero. For signed fields, the high-order bits should agree with |
2bc77e10 | 2537 | the sign bit. */ |
2538 | ||
2539 | if (lunsignedp) | |
2540 | { | |
2541 | if (! integer_zerop (const_binop (RSHIFT_EXPR, | |
2542 | convert (unsigned_type, rhs), | |
5485823f | 2543 | size_int (lbitsize), 0))) |
2bc77e10 | 2544 | { |
f4ec69cb | 2545 | warning ("comparison is always %d due to width of bit-field", |
be2828ce | 2546 | code == NE_EXPR); |
2bc77e10 | 2547 | return convert (compare_type, |
2548 | (code == NE_EXPR | |
2549 | ? integer_one_node : integer_zero_node)); | |
2550 | } | |
2551 | } | |
2552 | else | |
2553 | { | |
2554 | tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs), | |
5485823f | 2555 | size_int (lbitsize - 1), 0); |
2bc77e10 | 2556 | if (! integer_zerop (tem) && ! integer_all_onesp (tem)) |
2557 | { | |
f4ec69cb | 2558 | warning ("comparison is always %d due to width of bit-field", |
be2828ce | 2559 | code == NE_EXPR); |
2bc77e10 | 2560 | return convert (compare_type, |
2561 | (code == NE_EXPR | |
2562 | ? integer_one_node : integer_zero_node)); | |
2563 | } | |
2564 | } | |
2565 | ||
2566 | /* Single-bit compares should always be against zero. */ | |
2567 | if (lbitsize == 1 && ! integer_zerop (rhs)) | |
2568 | { | |
2569 | code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR; | |
2570 | rhs = convert (type, integer_zero_node); | |
2571 | } | |
2572 | ||
2573 | /* Make a new bitfield reference, shift the constant over the | |
2574 | appropriate number of bits and mask it with the computed mask | |
2575 | (in case this was a signed field). If we changed it, make a new one. */ | |
4d1060a2 | 2576 | lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1); |
e03ab35e | 2577 | if (lvolatilep) |
2578 | { | |
2579 | TREE_SIDE_EFFECTS (lhs) = 1; | |
2580 | TREE_THIS_VOLATILE (lhs) = 1; | |
2581 | } | |
2bc77e10 | 2582 | |
66716a97 | 2583 | rhs = fold (const_binop (BIT_AND_EXPR, |
2584 | const_binop (LSHIFT_EXPR, | |
2585 | convert (unsigned_type, rhs), | |
eb8ae79c | 2586 | size_int (lbitpos), 0), |
5485823f | 2587 | mask, 0)); |
2bc77e10 | 2588 | |
2589 | return build (code, compare_type, | |
66716a97 | 2590 | build (BIT_AND_EXPR, unsigned_type, lhs, mask), |
2bc77e10 | 2591 | rhs); |
2592 | } | |
2593 | \f | |
79109eec | 2594 | /* Subroutine for fold_truthop: decode a field reference. |
2bc77e10 | 2595 | |
2596 | If EXP is a comparison reference, we return the innermost reference. | |
2597 | ||
2598 | *PBITSIZE is set to the number of bits in the reference, *PBITPOS is | |
2599 | set to the starting bit number. | |
2600 | ||
2601 | If the innermost field can be completely contained in a mode-sized | |
2602 | unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode. | |
2603 | ||
2604 | *PVOLATILEP is set to 1 if the any expression encountered is volatile; | |
2605 | otherwise it is not changed. | |
2606 | ||
2607 | *PUNSIGNEDP is set to the signedness of the field. | |
2608 | ||
2609 | *PMASK is set to the mask used. This is either contained in a | |
2610 | BIT_AND_EXPR or derived from the width of the field. | |
2611 | ||
3398e91d | 2612 | *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any. |
2a6329ae | 2613 | |
2bc77e10 | 2614 | Return 0 if this is not a component reference or is one that we can't |
2615 | do anything with. */ | |
2616 | ||
2617 | static tree | |
2618 | decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp, | |
2a6329ae | 2619 | pvolatilep, pmask, pand_mask) |
2bc77e10 | 2620 | tree exp; |
02e7a332 | 2621 | HOST_WIDE_INT *pbitsize, *pbitpos; |
2bc77e10 | 2622 | enum machine_mode *pmode; |
2623 | int *punsignedp, *pvolatilep; | |
2624 | tree *pmask; | |
2a6329ae | 2625 | tree *pand_mask; |
2bc77e10 | 2626 | { |
4843fe7c | 2627 | tree and_mask = 0; |
2628 | tree mask, inner, offset; | |
2629 | tree unsigned_type; | |
02e7a332 | 2630 | unsigned int precision; |
2bc77e10 | 2631 | |
cc049fa3 | 2632 | /* All the optimizations using this function assume integer fields. |
e40566fc | 2633 | There are problems with FP fields since the type_for_size call |
2634 | below can fail for, e.g., XFmode. */ | |
2635 | if (! INTEGRAL_TYPE_P (TREE_TYPE (exp))) | |
2636 | return 0; | |
2637 | ||
2bc77e10 | 2638 | STRIP_NOPS (exp); |
2639 | ||
2640 | if (TREE_CODE (exp) == BIT_AND_EXPR) | |
2641 | { | |
4843fe7c | 2642 | and_mask = TREE_OPERAND (exp, 1); |
2bc77e10 | 2643 | exp = TREE_OPERAND (exp, 0); |
4843fe7c | 2644 | STRIP_NOPS (exp); STRIP_NOPS (and_mask); |
2645 | if (TREE_CODE (and_mask) != INTEGER_CST) | |
2bc77e10 | 2646 | return 0; |
2647 | } | |
2648 | ||
bbfbdece | 2649 | inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode, |
2b96c5f6 | 2650 | punsignedp, pvolatilep); |
94f29e88 | 2651 | if ((inner == exp && and_mask == 0) |
155b05dc | 2652 | || *pbitsize < 0 || offset != 0 |
2653 | || TREE_CODE (inner) == PLACEHOLDER_EXPR) | |
e233264a | 2654 | return 0; |
cc049fa3 | 2655 | |
4843fe7c | 2656 | /* Compute the mask to access the bitfield. */ |
771d21fa | 2657 | unsigned_type = (*lang_hooks.types.type_for_size) (*pbitsize, 1); |
4843fe7c | 2658 | precision = TYPE_PRECISION (unsigned_type); |
2659 | ||
2660 | mask = build_int_2 (~0, ~0); | |
2661 | TREE_TYPE (mask) = unsigned_type; | |
2662 | force_fit_type (mask, 0); | |
2663 | mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0); | |
2664 | mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0); | |
2665 | ||
2666 | /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */ | |
2667 | if (and_mask != 0) | |
2668 | mask = fold (build (BIT_AND_EXPR, unsigned_type, | |
2669 | convert (unsigned_type, and_mask), mask)); | |
2bc77e10 | 2670 | |
2671 | *pmask = mask; | |
2a6329ae | 2672 | *pand_mask = and_mask; |
2bc77e10 | 2673 | return inner; |
2674 | } | |
2675 | ||
6ef828f9 | 2676 | /* Return nonzero if MASK represents a mask of SIZE ones in the low-order |
2bc77e10 | 2677 | bit positions. */ |
2678 | ||
2679 | static int | |
2680 | all_ones_mask_p (mask, size) | |
2681 | tree mask; | |
2682 | int size; | |
2683 | { | |
2684 | tree type = TREE_TYPE (mask); | |
02e7a332 | 2685 | unsigned int precision = TYPE_PRECISION (type); |
52a49c7c | 2686 | tree tmask; |
2bc77e10 | 2687 | |
52a49c7c | 2688 | tmask = build_int_2 (~0, ~0); |
4070745f | 2689 | TREE_TYPE (tmask) = (*lang_hooks.types.signed_type) (type); |
86814797 | 2690 | force_fit_type (tmask, 0); |
2bc77e10 | 2691 | return |
cc049fa3 | 2692 | tree_int_cst_equal (mask, |
94f29e88 | 2693 | const_binop (RSHIFT_EXPR, |
2694 | const_binop (LSHIFT_EXPR, tmask, | |
2695 | size_int (precision - size), | |
2696 | 0), | |
2697 | size_int (precision - size), 0)); | |
2bc77e10 | 2698 | } |
79109eec | 2699 | |
203a24c4 | 2700 | /* Subroutine for fold: determine if VAL is the INTEGER_CONST that |
2701 | represents the sign bit of EXP's type. If EXP represents a sign | |
2702 | or zero extension, also test VAL against the unextended type. | |
2703 | The return value is the (sub)expression whose sign bit is VAL, | |
2704 | or NULL_TREE otherwise. */ | |
2705 | ||
2706 | static tree | |
2707 | sign_bit_p (exp, val) | |
2708 | tree exp; | |
2709 | tree val; | |
2710 | { | |
2711 | unsigned HOST_WIDE_INT lo; | |
2712 | HOST_WIDE_INT hi; | |
2713 | int width; | |
2714 | tree t; | |
2715 | ||
95cc2547 | 2716 | /* Tree EXP must have an integral type. */ |
203a24c4 | 2717 | t = TREE_TYPE (exp); |
2718 | if (! INTEGRAL_TYPE_P (t)) | |
2719 | return NULL_TREE; | |
2720 | ||
2721 | /* Tree VAL must be an integer constant. */ | |
2722 | if (TREE_CODE (val) != INTEGER_CST | |
2723 | || TREE_CONSTANT_OVERFLOW (val)) | |
2724 | return NULL_TREE; | |
2725 | ||
2726 | width = TYPE_PRECISION (t); | |
2727 | if (width > HOST_BITS_PER_WIDE_INT) | |
2728 | { | |
2729 | hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1); | |
2730 | lo = 0; | |
2731 | } | |
2732 | else | |
2733 | { | |
2734 | hi = 0; | |
2735 | lo = (unsigned HOST_WIDE_INT) 1 << (width - 1); | |
2736 | } | |
2737 | ||
2738 | if (TREE_INT_CST_HIGH (val) == hi && TREE_INT_CST_LOW (val) == lo) | |
2739 | return exp; | |
2740 | ||
2741 | /* Handle extension from a narrower type. */ | |
2742 | if (TREE_CODE (exp) == NOP_EXPR | |
2743 | && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width) | |
2744 | return sign_bit_p (TREE_OPERAND (exp, 0), val); | |
2745 | ||
2746 | return NULL_TREE; | |
2747 | } | |
2748 | ||
79109eec | 2749 | /* Subroutine for fold_truthop: determine if an operand is simple enough |
2750 | to be evaluated unconditionally. */ | |
2751 | ||
cc049fa3 | 2752 | static int |
79109eec | 2753 | simple_operand_p (exp) |
2754 | tree exp; | |
2755 | { | |
2756 | /* Strip any conversions that don't change the machine mode. */ | |
2757 | while ((TREE_CODE (exp) == NOP_EXPR | |
2758 | || TREE_CODE (exp) == CONVERT_EXPR) | |
2759 | && (TYPE_MODE (TREE_TYPE (exp)) | |
2760 | == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0))))) | |
2761 | exp = TREE_OPERAND (exp, 0); | |
2762 | ||
2763 | return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c' | |
9308e976 | 2764 | || (DECL_P (exp) |
79109eec | 2765 | && ! TREE_ADDRESSABLE (exp) |
2766 | && ! TREE_THIS_VOLATILE (exp) | |
7735dddb | 2767 | && ! DECL_NONLOCAL (exp) |
2768 | /* Don't regard global variables as simple. They may be | |
2769 | allocated in ways unknown to the compiler (shared memory, | |
2770 | #pragma weak, etc). */ | |
2771 | && ! TREE_PUBLIC (exp) | |
2772 | && ! DECL_EXTERNAL (exp) | |
2773 | /* Loading a static variable is unduly expensive, but global | |
2774 | registers aren't expensive. */ | |
2775 | && (! TREE_STATIC (exp) || DECL_REGISTER (exp)))); | |
79109eec | 2776 | } |
2bc77e10 | 2777 | \f |
12ec0a8a | 2778 | /* The following functions are subroutines to fold_range_test and allow it to |
2779 | try to change a logical combination of comparisons into a range test. | |
2780 | ||
2781 | For example, both | |
62af9abe | 2782 | X == 2 || X == 3 || X == 4 || X == 5 |
12ec0a8a | 2783 | and |
2784 | X >= 2 && X <= 5 | |
2785 | are converted to | |
2786 | (unsigned) (X - 2) <= 3 | |
2787 | ||
ad87de1e | 2788 | We describe each set of comparisons as being either inside or outside |
12ec0a8a | 2789 | a range, using a variable named like IN_P, and then describe the |
2790 | range with a lower and upper bound. If one of the bounds is omitted, | |
2791 | it represents either the highest or lowest value of the type. | |
2792 | ||
2793 | In the comments below, we represent a range by two numbers in brackets | |
ad87de1e | 2794 | preceded by a "+" to designate being inside that range, or a "-" to |
12ec0a8a | 2795 | designate being outside that range, so the condition can be inverted by |
2796 | flipping the prefix. An omitted bound is represented by a "-". For | |
2797 | example, "- [-, 10]" means being outside the range starting at the lowest | |
2798 | possible value and ending at 10, in other words, being greater than 10. | |
2799 | The range "+ [-, -]" is always true and hence the range "- [-, -]" is | |
2800 | always false. | |
2801 | ||
2802 | We set up things so that the missing bounds are handled in a consistent | |
2803 | manner so neither a missing bound nor "true" and "false" need to be | |
2804 | handled using a special case. */ | |
2805 | ||
2806 | /* Return the result of applying CODE to ARG0 and ARG1, but handle the case | |
2807 | of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P | |
2808 | and UPPER1_P are nonzero if the respective argument is an upper bound | |
2809 | and zero for a lower. TYPE, if nonzero, is the type of the result; it | |
2810 | must be specified for a comparison. ARG1 will be converted to ARG0's | |
2811 | type if both are specified. */ | |
6f725368 | 2812 | |
12ec0a8a | 2813 | static tree |
2814 | range_binop (code, type, arg0, upper0_p, arg1, upper1_p) | |
2815 | enum tree_code code; | |
2816 | tree type; | |
2817 | tree arg0, arg1; | |
2818 | int upper0_p, upper1_p; | |
2819 | { | |
7560c8de | 2820 | tree tem; |
12ec0a8a | 2821 | int result; |
2822 | int sgn0, sgn1; | |
6f725368 | 2823 | |
12ec0a8a | 2824 | /* If neither arg represents infinity, do the normal operation. |
2825 | Else, if not a comparison, return infinity. Else handle the special | |
2826 | comparison rules. Note that most of the cases below won't occur, but | |
2827 | are handled for consistency. */ | |
6f725368 | 2828 | |
12ec0a8a | 2829 | if (arg0 != 0 && arg1 != 0) |
7560c8de | 2830 | { |
2831 | tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0), | |
2832 | arg0, convert (TREE_TYPE (arg0), arg1))); | |
2833 | STRIP_NOPS (tem); | |
2834 | return TREE_CODE (tem) == INTEGER_CST ? tem : 0; | |
2835 | } | |
6f725368 | 2836 | |
12ec0a8a | 2837 | if (TREE_CODE_CLASS (code) != '<') |
2838 | return 0; | |
2839 | ||
2840 | /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0 | |
621ba396 | 2841 | for neither. In real maths, we cannot assume open ended ranges are |
2842 | the same. But, this is computer arithmetic, where numbers are finite. | |
2843 | We can therefore make the transformation of any unbounded range with | |
2844 | the value Z, Z being greater than any representable number. This permits | |
6312a35e | 2845 | us to treat unbounded ranges as equal. */ |
12ec0a8a | 2846 | sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1); |
263497ab | 2847 | sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1); |
12ec0a8a | 2848 | switch (code) |
2849 | { | |
621ba396 | 2850 | case EQ_EXPR: |
2851 | result = sgn0 == sgn1; | |
2852 | break; | |
2853 | case NE_EXPR: | |
2854 | result = sgn0 != sgn1; | |
12ec0a8a | 2855 | break; |
621ba396 | 2856 | case LT_EXPR: |
12ec0a8a | 2857 | result = sgn0 < sgn1; |
2858 | break; | |
621ba396 | 2859 | case LE_EXPR: |
2860 | result = sgn0 <= sgn1; | |
2861 | break; | |
2862 | case GT_EXPR: | |
12ec0a8a | 2863 | result = sgn0 > sgn1; |
2864 | break; | |
621ba396 | 2865 | case GE_EXPR: |
2866 | result = sgn0 >= sgn1; | |
2867 | break; | |
0dbd1c74 | 2868 | default: |
2869 | abort (); | |
12ec0a8a | 2870 | } |
2871 | ||
2872 | return convert (type, result ? integer_one_node : integer_zero_node); | |
2873 | } | |
cc049fa3 | 2874 | \f |
12ec0a8a | 2875 | /* Given EXP, a logical expression, set the range it is testing into |
2876 | variables denoted by PIN_P, PLOW, and PHIGH. Return the expression | |
62af9abe | 2877 | actually being tested. *PLOW and *PHIGH will be made of the same type |
12ec0a8a | 2878 | as the returned expression. If EXP is not a comparison, we will most |
2879 | likely not be returning a useful value and range. */ | |
6f725368 | 2880 | |
bfd67d2c | 2881 | static tree |
12ec0a8a | 2882 | make_range (exp, pin_p, plow, phigh) |
2883 | tree exp; | |
2884 | int *pin_p; | |
2885 | tree *plow, *phigh; | |
6f725368 | 2886 | { |
12ec0a8a | 2887 | enum tree_code code; |
5b7dad94 | 2888 | tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE; |
d6d65bd2 | 2889 | tree orig_type = NULL_TREE; |
12ec0a8a | 2890 | int in_p, n_in_p; |
2891 | tree low, high, n_low, n_high; | |
6f725368 | 2892 | |
12ec0a8a | 2893 | /* Start with simply saying "EXP != 0" and then look at the code of EXP |
2894 | and see if we can refine the range. Some of the cases below may not | |
2895 | happen, but it doesn't seem worth worrying about this. We "continue" | |
2896 | the outer loop when we've changed something; otherwise we "break" | |
2897 | the switch, which will "break" the while. */ | |
6f725368 | 2898 | |
12ec0a8a | 2899 | in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node); |
2900 | ||
2901 | while (1) | |
6f725368 | 2902 | { |
12ec0a8a | 2903 | code = TREE_CODE (exp); |
5eb945de | 2904 | |
2905 | if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code))) | |
2906 | { | |
2907 | arg0 = TREE_OPERAND (exp, 0); | |
cc049fa3 | 2908 | if (TREE_CODE_CLASS (code) == '<' |
5eb945de | 2909 | || TREE_CODE_CLASS (code) == '1' |
2910 | || TREE_CODE_CLASS (code) == '2') | |
2911 | type = TREE_TYPE (arg0); | |
cc049fa3 | 2912 | if (TREE_CODE_CLASS (code) == '2' |
5eb945de | 2913 | || TREE_CODE_CLASS (code) == '<' |
cc049fa3 | 2914 | || (TREE_CODE_CLASS (code) == 'e' |
3f1e707c | 2915 | && TREE_CODE_LENGTH (code) > 1)) |
5eb945de | 2916 | arg1 = TREE_OPERAND (exp, 1); |
2917 | } | |
6f725368 | 2918 | |
4c1dda4b | 2919 | /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not |
2920 | lose a cast by accident. */ | |
2921 | if (type != NULL_TREE && orig_type == NULL_TREE) | |
2922 | orig_type = type; | |
2923 | ||
12ec0a8a | 2924 | switch (code) |
2925 | { | |
2926 | case TRUTH_NOT_EXPR: | |
2927 | in_p = ! in_p, exp = arg0; | |
2928 | continue; | |
2929 | ||
2930 | case EQ_EXPR: case NE_EXPR: | |
2931 | case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR: | |
2932 | /* We can only do something if the range is testing for zero | |
2933 | and if the second operand is an integer constant. Note that | |
2934 | saying something is "in" the range we make is done by | |
2935 | complementing IN_P since it will set in the initial case of | |
2936 | being not equal to zero; "out" is leaving it alone. */ | |
2937 | if (low == 0 || high == 0 | |
2938 | || ! integer_zerop (low) || ! integer_zerop (high) | |
2939 | || TREE_CODE (arg1) != INTEGER_CST) | |
2940 | break; | |
6f725368 | 2941 | |
12ec0a8a | 2942 | switch (code) |
2943 | { | |
2944 | case NE_EXPR: /* - [c, c] */ | |
2945 | low = high = arg1; | |
2946 | break; | |
2947 | case EQ_EXPR: /* + [c, c] */ | |
2948 | in_p = ! in_p, low = high = arg1; | |
2949 | break; | |
2950 | case GT_EXPR: /* - [-, c] */ | |
2951 | low = 0, high = arg1; | |
2952 | break; | |
2953 | case GE_EXPR: /* + [c, -] */ | |
2954 | in_p = ! in_p, low = arg1, high = 0; | |
2955 | break; | |
2956 | case LT_EXPR: /* - [c, -] */ | |
2957 | low = arg1, high = 0; | |
2958 | break; | |
2959 | case LE_EXPR: /* + [-, c] */ | |
2960 | in_p = ! in_p, low = 0, high = arg1; | |
2961 | break; | |
0dbd1c74 | 2962 | default: |
2963 | abort (); | |
12ec0a8a | 2964 | } |
6f725368 | 2965 | |
12ec0a8a | 2966 | exp = arg0; |
6f725368 | 2967 | |
c317c285 | 2968 | /* If this is an unsigned comparison, we also know that EXP is |
a9e29e86 | 2969 | greater than or equal to zero. We base the range tests we make |
2970 | on that fact, so we record it here so we can parse existing | |
2971 | range tests. */ | |
c317c285 | 2972 | if (TREE_UNSIGNED (type) && (low == 0 || high == 0)) |
12ec0a8a | 2973 | { |
2974 | if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high, | |
2975 | 1, convert (type, integer_zero_node), | |
a9e29e86 | 2976 | NULL_TREE)) |
12ec0a8a | 2977 | break; |
6f725368 | 2978 | |
12ec0a8a | 2979 | in_p = n_in_p, low = n_low, high = n_high; |
a9e29e86 | 2980 | |
ce7c53cc | 2981 | /* If the high bound is missing, but we |
2982 | have a low bound, reverse the range so | |
2983 | it goes from zero to the low bound minus 1. */ | |
2984 | if (high == 0 && low) | |
a9e29e86 | 2985 | { |
2986 | in_p = ! in_p; | |
2987 | high = range_binop (MINUS_EXPR, NULL_TREE, low, 0, | |
2988 | integer_one_node, 0); | |
2989 | low = convert (type, integer_zero_node); | |
2990 | } | |
12ec0a8a | 2991 | } |
2992 | continue; | |
2993 | ||
2994 | case NEGATE_EXPR: | |
2995 | /* (-x) IN [a,b] -> x in [-b, -a] */ | |
2996 | n_low = range_binop (MINUS_EXPR, type, | |
2997 | convert (type, integer_zero_node), 0, high, 1); | |
2998 | n_high = range_binop (MINUS_EXPR, type, | |
2999 | convert (type, integer_zero_node), 0, low, 0); | |
3000 | low = n_low, high = n_high; | |
3001 | exp = arg0; | |
3002 | continue; | |
3003 | ||
3004 | case BIT_NOT_EXPR: | |
3005 | /* ~ X -> -X - 1 */ | |
23ec2d5e | 3006 | exp = build (MINUS_EXPR, type, negate_expr (arg0), |
7560c8de | 3007 | convert (type, integer_one_node)); |
12ec0a8a | 3008 | continue; |
3009 | ||
3010 | case PLUS_EXPR: case MINUS_EXPR: | |
3011 | if (TREE_CODE (arg1) != INTEGER_CST) | |
3012 | break; | |
3013 | ||
3014 | /* If EXP is signed, any overflow in the computation is undefined, | |
3015 | so we don't worry about it so long as our computations on | |
3016 | the bounds don't overflow. For unsigned, overflow is defined | |
3017 | and this is exactly the right thing. */ | |
3018 | n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR, | |
3019 | type, low, 0, arg1, 0); | |
3020 | n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR, | |
3021 | type, high, 1, arg1, 0); | |
3022 | if ((n_low != 0 && TREE_OVERFLOW (n_low)) | |
3023 | || (n_high != 0 && TREE_OVERFLOW (n_high))) | |
3024 | break; | |
3025 | ||
6b457c77 | 3026 | /* Check for an unsigned range which has wrapped around the maximum |
3027 | value thus making n_high < n_low, and normalize it. */ | |
98db800f | 3028 | if (n_low && n_high && tree_int_cst_lt (n_high, n_low)) |
6b457c77 | 3029 | { |
3030 | low = range_binop (PLUS_EXPR, type, n_high, 0, | |
a9e29e86 | 3031 | integer_one_node, 0); |
6b457c77 | 3032 | high = range_binop (MINUS_EXPR, type, n_low, 0, |
a80d786b | 3033 | integer_one_node, 0); |
3034 | ||
3035 | /* If the range is of the form +/- [ x+1, x ], we won't | |
3036 | be able to normalize it. But then, it represents the | |
3037 | whole range or the empty set, so make it | |
3038 | +/- [ -, - ]. */ | |
3039 | if (tree_int_cst_equal (n_low, low) | |
3040 | && tree_int_cst_equal (n_high, high)) | |
3041 | low = high = 0; | |
3042 | else | |
3043 | in_p = ! in_p; | |
6b457c77 | 3044 | } |
98db800f | 3045 | else |
3046 | low = n_low, high = n_high; | |
7560c8de | 3047 | |
12ec0a8a | 3048 | exp = arg0; |
3049 | continue; | |
3050 | ||
3051 | case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR: | |
d6d65bd2 | 3052 | if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type)) |
3053 | break; | |
3054 | ||
12ec0a8a | 3055 | if (! INTEGRAL_TYPE_P (type) |
3056 | || (low != 0 && ! int_fits_type_p (low, type)) | |
3057 | || (high != 0 && ! int_fits_type_p (high, type))) | |
3058 | break; | |
3059 | ||
4cd44a59 | 3060 | n_low = low, n_high = high; |
12ec0a8a | 3061 | |
4cd44a59 | 3062 | if (n_low != 0) |
3063 | n_low = convert (type, n_low); | |
3064 | ||
3065 | if (n_high != 0) | |
3066 | n_high = convert (type, n_high); | |
3067 | ||
3068 | /* If we're converting from an unsigned to a signed type, | |
3069 | we will be doing the comparison as unsigned. The tests above | |
3070 | have already verified that LOW and HIGH are both positive. | |
3071 | ||
3072 | So we have to make sure that the original unsigned value will | |
3073 | be interpreted as positive. */ | |
3074 | if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp))) | |
3075 | { | |
771d21fa | 3076 | tree equiv_type = (*lang_hooks.types.type_for_mode) |
3077 | (TYPE_MODE (type), 1); | |
f52483b5 | 3078 | tree high_positive; |
3079 | ||
3080 | /* A range without an upper bound is, naturally, unbounded. | |
3081 | Since convert would have cropped a very large value, use | |
155b05dc | 3082 | the max value for the destination type. */ |
3083 | high_positive | |
3084 | = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type) | |
3085 | : TYPE_MAX_VALUE (type); | |
f52483b5 | 3086 | |
02846a3d | 3087 | if (TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (exp))) |
3088 | high_positive = fold (build (RSHIFT_EXPR, type, | |
3089 | convert (type, high_positive), | |
3090 | convert (type, integer_one_node))); | |
cc049fa3 | 3091 | |
4cd44a59 | 3092 | /* If the low bound is specified, "and" the range with the |
3093 | range for which the original unsigned value will be | |
3094 | positive. */ | |
3095 | if (low != 0) | |
3096 | { | |
3097 | if (! merge_ranges (&n_in_p, &n_low, &n_high, | |
3098 | 1, n_low, n_high, | |
3099 | 1, convert (type, integer_zero_node), | |
3100 | high_positive)) | |
3101 | break; | |
3102 | ||
3103 | in_p = (n_in_p == in_p); | |
3104 | } | |
3105 | else | |
3106 | { | |
3107 | /* Otherwise, "or" the range with the range of the input | |
3108 | that will be interpreted as negative. */ | |
3109 | if (! merge_ranges (&n_in_p, &n_low, &n_high, | |
3110 | 0, n_low, n_high, | |
3111 | 1, convert (type, integer_zero_node), | |
3112 | high_positive)) | |
3113 | break; | |
3114 | ||
3115 | in_p = (in_p != n_in_p); | |
3116 | } | |
3117 | } | |
12ec0a8a | 3118 | |
3119 | exp = arg0; | |
4cd44a59 | 3120 | low = n_low, high = n_high; |
12ec0a8a | 3121 | continue; |
4cd44a59 | 3122 | |
3123 | default: | |
3124 | break; | |
6f725368 | 3125 | } |
12ec0a8a | 3126 | |
3127 | break; | |
6f725368 | 3128 | } |
12ec0a8a | 3129 | |
f83854c8 | 3130 | /* If EXP is a constant, we can evaluate whether this is true or false. */ |
3131 | if (TREE_CODE (exp) == INTEGER_CST) | |
3132 | { | |
3133 | in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node, | |
3134 | exp, 0, low, 0)) | |
3135 | && integer_onep (range_binop (LE_EXPR, integer_type_node, | |
3136 | exp, 1, high, 1))); | |
3137 | low = high = 0; | |
3138 | exp = 0; | |
3139 | } | |
3140 | ||
12ec0a8a | 3141 | *pin_p = in_p, *plow = low, *phigh = high; |
3142 | return exp; | |
3143 | } | |
3144 | \f | |
3145 | /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result | |
3146 | type, TYPE, return an expression to test if EXP is in (or out of, depending | |
3147 | on IN_P) the range. */ | |
3148 | ||
3149 | static tree | |
3150 | build_range_check (type, exp, in_p, low, high) | |
3151 | tree type; | |
3152 | tree exp; | |
3153 | int in_p; | |
3154 | tree low, high; | |
3155 | { | |
3156 | tree etype = TREE_TYPE (exp); | |
843dd7a3 | 3157 | tree value; |
12ec0a8a | 3158 | |
3159 | if (! in_p | |
3160 | && (0 != (value = build_range_check (type, exp, 1, low, high)))) | |
3161 | return invert_truthvalue (value); | |
3162 | ||
843dd7a3 | 3163 | if (low == 0 && high == 0) |
12ec0a8a | 3164 | return convert (type, integer_one_node); |
3165 | ||
843dd7a3 | 3166 | if (low == 0) |
12ec0a8a | 3167 | return fold (build (LE_EXPR, type, exp, high)); |
3168 | ||
843dd7a3 | 3169 | if (high == 0) |
12ec0a8a | 3170 | return fold (build (GE_EXPR, type, exp, low)); |
3171 | ||
843dd7a3 | 3172 | if (operand_equal_p (low, high, 0)) |
12ec0a8a | 3173 | return fold (build (EQ_EXPR, type, exp, low)); |
3174 | ||
843dd7a3 | 3175 | if (integer_zerop (low)) |
6f725368 | 3176 | { |
843dd7a3 | 3177 | if (! TREE_UNSIGNED (etype)) |
d3371fcd | 3178 | { |
3179 | etype = (*lang_hooks.types.unsigned_type) (etype); | |
3180 | high = convert (etype, high); | |
3181 | exp = convert (etype, exp); | |
3182 | } | |
843dd7a3 | 3183 | return build_range_check (type, exp, 1, 0, high); |
12ec0a8a | 3184 | } |
6f725368 | 3185 | |
843dd7a3 | 3186 | /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */ |
3187 | if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST) | |
3188 | { | |
3189 | unsigned HOST_WIDE_INT lo; | |
3190 | HOST_WIDE_INT hi; | |
3191 | int prec; | |
3192 | ||
3193 | prec = TYPE_PRECISION (etype); | |
3194 | if (prec <= HOST_BITS_PER_WIDE_INT) | |
d3371fcd | 3195 | { |
3196 | hi = 0; | |
3197 | lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1; | |
3198 | } | |
843dd7a3 | 3199 | else |
d3371fcd | 3200 | { |
3201 | hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1; | |
3202 | lo = (unsigned HOST_WIDE_INT) -1; | |
3203 | } | |
843dd7a3 | 3204 | |
3205 | if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo) | |
d3371fcd | 3206 | { |
3207 | if (TREE_UNSIGNED (etype)) | |
3208 | { | |
3209 | etype = (*lang_hooks.types.signed_type) (etype); | |
3210 | exp = convert (etype, exp); | |
3211 | } | |
3212 | return fold (build (GT_EXPR, type, exp, | |
3213 | convert (etype, integer_zero_node))); | |
3214 | } | |
843dd7a3 | 3215 | } |
3216 | ||
3217 | if (0 != (value = const_binop (MINUS_EXPR, high, low, 0)) | |
3218 | && ! TREE_OVERFLOW (value)) | |
12ec0a8a | 3219 | return build_range_check (type, |
3220 | fold (build (MINUS_EXPR, etype, exp, low)), | |
3221 | 1, convert (etype, integer_zero_node), value); | |
843dd7a3 | 3222 | |
3223 | return 0; | |
12ec0a8a | 3224 | } |
3225 | \f | |
cc049fa3 | 3226 | /* Given two ranges, see if we can merge them into one. Return 1 if we |
12ec0a8a | 3227 | can, 0 if we can't. Set the output range into the specified parameters. */ |
6f725368 | 3228 | |
12ec0a8a | 3229 | static int |
3230 | merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1) | |
3231 | int *pin_p; | |
3232 | tree *plow, *phigh; | |
3233 | int in0_p, in1_p; | |
3234 | tree low0, high0, low1, high1; | |
3235 | { | |
3236 | int no_overlap; | |
3237 | int subset; | |
3238 | int temp; | |
3239 | tree tem; | |
3240 | int in_p; | |
3241 | tree low, high; | |
4cd44a59 | 3242 | int lowequal = ((low0 == 0 && low1 == 0) |
3243 | || integer_onep (range_binop (EQ_EXPR, integer_type_node, | |
3244 | low0, 0, low1, 0))); | |
3245 | int highequal = ((high0 == 0 && high1 == 0) | |
3246 | || integer_onep (range_binop (EQ_EXPR, integer_type_node, | |
3247 | high0, 1, high1, 1))); | |
3248 | ||
3249 | /* Make range 0 be the range that starts first, or ends last if they | |
3250 | start at the same value. Swap them if it isn't. */ | |
cc049fa3 | 3251 | if (integer_onep (range_binop (GT_EXPR, integer_type_node, |
12ec0a8a | 3252 | low0, 0, low1, 0)) |
4cd44a59 | 3253 | || (lowequal |
12ec0a8a | 3254 | && integer_onep (range_binop (GT_EXPR, integer_type_node, |
4cd44a59 | 3255 | high1, 1, high0, 1)))) |
12ec0a8a | 3256 | { |
3257 | temp = in0_p, in0_p = in1_p, in1_p = temp; | |
3258 | tem = low0, low0 = low1, low1 = tem; | |
3259 | tem = high0, high0 = high1, high1 = tem; | |
3260 | } | |
6f725368 | 3261 | |
12ec0a8a | 3262 | /* Now flag two cases, whether the ranges are disjoint or whether the |
3263 | second range is totally subsumed in the first. Note that the tests | |
3264 | below are simplified by the ones above. */ | |
3265 | no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node, | |
3266 | high0, 1, low1, 0)); | |
718acf6d | 3267 | subset = integer_onep (range_binop (LE_EXPR, integer_type_node, |
12ec0a8a | 3268 | high1, 1, high0, 1)); |
3269 | ||
3270 | /* We now have four cases, depending on whether we are including or | |
3271 | excluding the two ranges. */ | |
3272 | if (in0_p && in1_p) | |
3273 | { | |
3274 | /* If they don't overlap, the result is false. If the second range | |
3275 | is a subset it is the result. Otherwise, the range is from the start | |
3276 | of the second to the end of the first. */ | |
3277 | if (no_overlap) | |
3278 | in_p = 0, low = high = 0; | |
3279 | else if (subset) | |
3280 | in_p = 1, low = low1, high = high1; | |
3281 | else | |
3282 | in_p = 1, low = low1, high = high0; | |
3283 | } | |
6f725368 | 3284 | |
12ec0a8a | 3285 | else if (in0_p && ! in1_p) |
3286 | { | |
4cd44a59 | 3287 | /* If they don't overlap, the result is the first range. If they are |
3288 | equal, the result is false. If the second range is a subset of the | |
3289 | first, and the ranges begin at the same place, we go from just after | |
3290 | the end of the first range to the end of the second. If the second | |
3291 | range is not a subset of the first, or if it is a subset and both | |
3292 | ranges end at the same place, the range starts at the start of the | |
3293 | first range and ends just before the second range. | |
3294 | Otherwise, we can't describe this as a single range. */ | |
12ec0a8a | 3295 | if (no_overlap) |
3296 | in_p = 1, low = low0, high = high0; | |
4cd44a59 | 3297 | else if (lowequal && highequal) |
08986c47 | 3298 | in_p = 0, low = high = 0; |
4cd44a59 | 3299 | else if (subset && lowequal) |
3300 | { | |
3301 | in_p = 1, high = high0; | |
3302 | low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0, | |
cc049fa3 | 3303 | integer_one_node, 0); |
4cd44a59 | 3304 | } |
3305 | else if (! subset || highequal) | |
12ec0a8a | 3306 | { |
3307 | in_p = 1, low = low0; | |
3308 | high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0, | |
a9e29e86 | 3309 | integer_one_node, 0); |
12ec0a8a | 3310 | } |
4cd44a59 | 3311 | else |
3312 | return 0; | |
12ec0a8a | 3313 | } |
6f725368 | 3314 | |
12ec0a8a | 3315 | else if (! in0_p && in1_p) |
3316 | { | |
3317 | /* If they don't overlap, the result is the second range. If the second | |
3318 | is a subset of the first, the result is false. Otherwise, | |
3319 | the range starts just after the first range and ends at the | |
3320 | end of the second. */ | |
3321 | if (no_overlap) | |
3322 | in_p = 1, low = low1, high = high1; | |
155b05dc | 3323 | else if (subset || highequal) |
12ec0a8a | 3324 | in_p = 0, low = high = 0; |
3325 | else | |
3326 | { | |
3327 | in_p = 1, high = high1; | |
3328 | low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1, | |
3329 | integer_one_node, 0); | |
6f725368 | 3330 | } |
3331 | } | |
3332 | ||
12ec0a8a | 3333 | else |
3334 | { | |
3335 | /* The case where we are excluding both ranges. Here the complex case | |
3336 | is if they don't overlap. In that case, the only time we have a | |
3337 | range is if they are adjacent. If the second is a subset of the | |
3338 | first, the result is the first. Otherwise, the range to exclude | |
3339 | starts at the beginning of the first range and ends at the end of the | |
3340 | second. */ | |
3341 | if (no_overlap) | |
3342 | { | |
3343 | if (integer_onep (range_binop (EQ_EXPR, integer_type_node, | |
3344 | range_binop (PLUS_EXPR, NULL_TREE, | |
3345 | high0, 1, | |
3346 | integer_one_node, 1), | |
3347 | 1, low1, 0))) | |
3348 | in_p = 0, low = low0, high = high1; | |
3349 | else | |
3350 | return 0; | |
3351 | } | |
3352 | else if (subset) | |
3353 | in_p = 0, low = low0, high = high0; | |
3354 | else | |
3355 | in_p = 0, low = low0, high = high1; | |
3356 | } | |
b29eae68 | 3357 | |
12ec0a8a | 3358 | *pin_p = in_p, *plow = low, *phigh = high; |
3359 | return 1; | |
3360 | } | |
3361 | \f | |
3362 | /* EXP is some logical combination of boolean tests. See if we can | |
3363 | merge it into some range test. Return the new tree if so. */ | |
6f725368 | 3364 | |
12ec0a8a | 3365 | static tree |
3366 | fold_range_test (exp) | |
3367 | tree exp; | |
3368 | { | |
3369 | int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR | |
3370 | || TREE_CODE (exp) == TRUTH_OR_EXPR); | |
3371 | int in0_p, in1_p, in_p; | |
3372 | tree low0, low1, low, high0, high1, high; | |
3373 | tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0); | |
3374 | tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1); | |
3375 | tree tem; | |
6f725368 | 3376 | |
12ec0a8a | 3377 | /* If this is an OR operation, invert both sides; we will invert |
3378 | again at the end. */ | |
3379 | if (or_op) | |
3380 | in0_p = ! in0_p, in1_p = ! in1_p; | |
3381 | ||
3382 | /* If both expressions are the same, if we can merge the ranges, and we | |
f83854c8 | 3383 | can build the range test, return it or it inverted. If one of the |
3384 | ranges is always true or always false, consider it to be the same | |
3385 | expression as the other. */ | |
3386 | if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0)) | |
12ec0a8a | 3387 | && merge_ranges (&in_p, &low, &high, in0_p, low0, high0, |
3388 | in1_p, low1, high1) | |
f83854c8 | 3389 | && 0 != (tem = (build_range_check (TREE_TYPE (exp), |
3390 | lhs != 0 ? lhs | |
3391 | : rhs != 0 ? rhs : integer_zero_node, | |
12ec0a8a | 3392 | in_p, low, high)))) |
3393 | return or_op ? invert_truthvalue (tem) : tem; | |
3394 | ||
3395 | /* On machines where the branch cost is expensive, if this is a | |
3396 | short-circuited branch and the underlying object on both sides | |
3397 | is the same, make a non-short-circuit operation. */ | |
3398 | else if (BRANCH_COST >= 2 | |
1fdbc76b | 3399 | && lhs != 0 && rhs != 0 |
12ec0a8a | 3400 | && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR |
3401 | || TREE_CODE (exp) == TRUTH_ORIF_EXPR) | |
3402 | && operand_equal_p (lhs, rhs, 0)) | |
6f725368 | 3403 | { |
90a73592 | 3404 | /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR |
9e042f31 | 3405 | unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in |
3406 | which cases we can't do this. */ | |
12ec0a8a | 3407 | if (simple_operand_p (lhs)) |
3408 | return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR | |
3409 | ? TRUTH_AND_EXPR : TRUTH_OR_EXPR, | |
3410 | TREE_TYPE (exp), TREE_OPERAND (exp, 0), | |
3411 | TREE_OPERAND (exp, 1)); | |
90a73592 | 3412 | |
20325f61 | 3413 | else if ((*lang_hooks.decls.global_bindings_p) () == 0 |
9e042f31 | 3414 | && ! contains_placeholder_p (lhs)) |
12ec0a8a | 3415 | { |
3416 | tree common = save_expr (lhs); | |
3417 | ||
3418 | if (0 != (lhs = build_range_check (TREE_TYPE (exp), common, | |
3419 | or_op ? ! in0_p : in0_p, | |
3420 | low0, high0)) | |
3421 | && (0 != (rhs = build_range_check (TREE_TYPE (exp), common, | |
3422 | or_op ? ! in1_p : in1_p, | |
3423 | low1, high1)))) | |
3424 | return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR | |
3425 | ? TRUTH_AND_EXPR : TRUTH_OR_EXPR, | |
3426 | TREE_TYPE (exp), lhs, rhs); | |
3427 | } | |
6f725368 | 3428 | } |
831e3af4 | 3429 | |
831e3af4 | 3430 | return 0; |
6f725368 | 3431 | } |
3432 | \f | |
94f29e88 | 3433 | /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P |
b2dcfbf7 | 3434 | bit value. Arrange things so the extra bits will be set to zero if and |
2a6329ae | 3435 | only if C is signed-extended to its full width. If MASK is nonzero, |
3436 | it is an INTEGER_CST that should be AND'ed with the extra bits. */ | |
94f29e88 | 3437 | |
3438 | static tree | |
2a6329ae | 3439 | unextend (c, p, unsignedp, mask) |
94f29e88 | 3440 | tree c; |
3441 | int p; | |
3442 | int unsignedp; | |
2a6329ae | 3443 | tree mask; |
94f29e88 | 3444 | { |
3445 | tree type = TREE_TYPE (c); | |
3446 | int modesize = GET_MODE_BITSIZE (TYPE_MODE (type)); | |
3447 | tree temp; | |
3448 | ||
3449 | if (p == modesize || unsignedp) | |
3450 | return c; | |
3451 | ||
94f29e88 | 3452 | /* We work by getting just the sign bit into the low-order bit, then |
c3418f42 | 3453 | into the high-order bit, then sign-extend. We then XOR that value |
94f29e88 | 3454 | with C. */ |
3455 | temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0); | |
3456 | temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0); | |
dd5f6dae | 3457 | |
3458 | /* We must use a signed type in order to get an arithmetic right shift. | |
3459 | However, we must also avoid introducing accidental overflows, so that | |
cc049fa3 | 3460 | a subsequent call to integer_zerop will work. Hence we must |
dd5f6dae | 3461 | do the type conversion here. At this point, the constant is either |
3462 | zero or one, and the conversion to a signed type can never overflow. | |
3463 | We could get an overflow if this conversion is done anywhere else. */ | |
3464 | if (TREE_UNSIGNED (type)) | |
4070745f | 3465 | temp = convert ((*lang_hooks.types.signed_type) (type), temp); |
dd5f6dae | 3466 | |
94f29e88 | 3467 | temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0); |
3468 | temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0); | |
2a6329ae | 3469 | if (mask != 0) |
3470 | temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0); | |
dd5f6dae | 3471 | /* If necessary, convert the type back to match the type of C. */ |
3472 | if (TREE_UNSIGNED (type)) | |
3473 | temp = convert (type, temp); | |
2a6329ae | 3474 | |
94f29e88 | 3475 | return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0)); |
3476 | } | |
3477 | \f | |
79109eec | 3478 | /* Find ways of folding logical expressions of LHS and RHS: |
3479 | Try to merge two comparisons to the same innermost item. | |
3480 | Look for range tests like "ch >= '0' && ch <= '9'". | |
3481 | Look for combinations of simple terms on machines with expensive branches | |
3482 | and evaluate the RHS unconditionally. | |
2bc77e10 | 3483 | |
3484 | For example, if we have p->a == 2 && p->b == 4 and we can make an | |
3485 | object large enough to span both A and B, we can do this with a comparison | |
3486 | against the object ANDed with the a mask. | |
3487 | ||
3488 | If we have p->a == q->a && p->b == q->b, we may be able to use bit masking | |
3489 | operations to do this with one comparison. | |
3490 | ||
3491 | We check for both normal comparisons and the BIT_AND_EXPRs made this by | |
3492 | function and the one above. | |
3493 | ||
3494 | CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR, | |
3495 | TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR. | |
3496 | ||
3497 | TRUTH_TYPE is the type of the logical operand and LHS and RHS are its | |
3498 | two operands. | |
3499 | ||
3500 | We return the simplified tree or 0 if no optimization is possible. */ | |
3501 | ||
3502 | static tree | |
79109eec | 3503 | fold_truthop (code, truth_type, lhs, rhs) |
2bc77e10 | 3504 | enum tree_code code; |
3505 | tree truth_type, lhs, rhs; | |
3506 | { | |
62af9abe | 3507 | /* If this is the "or" of two comparisons, we can do something if |
2bc77e10 | 3508 | the comparisons are NE_EXPR. If this is the "and", we can do something |
cc049fa3 | 3509 | if the comparisons are EQ_EXPR. I.e., |
2bc77e10 | 3510 | (a->b == 2 && a->c == 4) can become (a->new == NEW). |
3511 | ||
3512 | WANTED_CODE is this operation code. For single bit fields, we can | |
3513 | convert EQ_EXPR to NE_EXPR so we need not reject the "wrong" | |
3514 | comparison for one-bit fields. */ | |
3515 | ||
79109eec | 3516 | enum tree_code wanted_code; |
2bc77e10 | 3517 | enum tree_code lcode, rcode; |
79109eec | 3518 | tree ll_arg, lr_arg, rl_arg, rr_arg; |
2bc77e10 | 3519 | tree ll_inner, lr_inner, rl_inner, rr_inner; |
02e7a332 | 3520 | HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos; |
3521 | HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos; | |
3522 | HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos; | |
3523 | HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos; | |
2bc77e10 | 3524 | int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp; |
3525 | enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode; | |
3526 | enum machine_mode lnmode, rnmode; | |
3527 | tree ll_mask, lr_mask, rl_mask, rr_mask; | |
2a6329ae | 3528 | tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask; |
79109eec | 3529 | tree l_const, r_const; |
ffba564c | 3530 | tree lntype, rntype, result; |
2bc77e10 | 3531 | int first_bit, end_bit; |
79109eec | 3532 | int volatilep; |
2bc77e10 | 3533 | |
12ec0a8a | 3534 | /* Start by getting the comparison codes. Fail if anything is volatile. |
3535 | If one operand is a BIT_AND_EXPR with the constant one, treat it as if | |
3536 | it were surrounded with a NE_EXPR. */ | |
2bc77e10 | 3537 | |
12ec0a8a | 3538 | if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs)) |
79109eec | 3539 | return 0; |
3540 | ||
2bc77e10 | 3541 | lcode = TREE_CODE (lhs); |
3542 | rcode = TREE_CODE (rhs); | |
6f725368 | 3543 | |
b5ab1edd | 3544 | if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1))) |
3545 | lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node); | |
3546 | ||
3547 | if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1))) | |
3548 | rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node); | |
3549 | ||
12ec0a8a | 3550 | if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<') |
6f725368 | 3551 | return 0; |
3552 | ||
79109eec | 3553 | code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR) |
76e4a18b | 3554 | ? TRUTH_AND_EXPR : TRUTH_OR_EXPR); |
79109eec | 3555 | |
3556 | ll_arg = TREE_OPERAND (lhs, 0); | |
3557 | lr_arg = TREE_OPERAND (lhs, 1); | |
3558 | rl_arg = TREE_OPERAND (rhs, 0); | |
3559 | rr_arg = TREE_OPERAND (rhs, 1); | |
cc049fa3 | 3560 | |
7835f163 | 3561 | /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */ |
3562 | if (simple_operand_p (ll_arg) | |
3563 | && simple_operand_p (lr_arg) | |
3564 | && !FLOAT_TYPE_P (TREE_TYPE (ll_arg))) | |
3565 | { | |
3566 | int compcode; | |
3567 | ||
3568 | if (operand_equal_p (ll_arg, rl_arg, 0) | |
3569 | && operand_equal_p (lr_arg, rr_arg, 0)) | |
3570 | { | |
3571 | int lcompcode, rcompcode; | |
3572 | ||
3573 | lcompcode = comparison_to_compcode (lcode); | |
3574 | rcompcode = comparison_to_compcode (rcode); | |
3575 | compcode = (code == TRUTH_AND_EXPR) | |
3576 | ? lcompcode & rcompcode | |
3577 | : lcompcode | rcompcode; | |
3578 | } | |
3579 | else if (operand_equal_p (ll_arg, rr_arg, 0) | |
3580 | && operand_equal_p (lr_arg, rl_arg, 0)) | |
3581 | { | |
3582 | int lcompcode, rcompcode; | |
3583 | ||
3584 | rcode = swap_tree_comparison (rcode); | |
3585 | lcompcode = comparison_to_compcode (lcode); | |
3586 | rcompcode = comparison_to_compcode (rcode); | |
3587 | compcode = (code == TRUTH_AND_EXPR) | |
3588 | ? lcompcode & rcompcode | |
3589 | : lcompcode | rcompcode; | |
3590 | } | |
3591 | else | |
3592 | compcode = -1; | |
3593 | ||
3594 | if (compcode == COMPCODE_TRUE) | |
3595 | return convert (truth_type, integer_one_node); | |
3596 | else if (compcode == COMPCODE_FALSE) | |
3597 | return convert (truth_type, integer_zero_node); | |
3598 | else if (compcode != -1) | |
3599 | return build (compcode_to_comparison (compcode), | |
3600 | truth_type, ll_arg, lr_arg); | |
3601 | } | |
3602 | ||
7735dddb | 3603 | /* If the RHS can be evaluated unconditionally and its operands are |
79109eec | 3604 | simple, it wins to evaluate the RHS unconditionally on machines |
3605 | with expensive branches. In this case, this isn't a comparison | |
35212e61 | 3606 | that can be merged. Avoid doing this if the RHS is a floating-point |
3607 | comparison since those can trap. */ | |
79109eec | 3608 | |
3609 | if (BRANCH_COST >= 2 | |
35212e61 | 3610 | && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg)) |
79109eec | 3611 | && simple_operand_p (rl_arg) |
7735dddb | 3612 | && simple_operand_p (rr_arg)) |
0425437e | 3613 | { |
3614 | /* Convert (a != 0) || (b != 0) into (a | b) != 0. */ | |
3615 | if (code == TRUTH_OR_EXPR | |
3616 | && lcode == NE_EXPR && integer_zerop (lr_arg) | |
3617 | && rcode == NE_EXPR && integer_zerop (rr_arg) | |
3618 | && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)) | |
3619 | return build (NE_EXPR, truth_type, | |
3620 | build (BIT_IOR_EXPR, TREE_TYPE (ll_arg), | |
3621 | ll_arg, rl_arg), | |
3622 | integer_zero_node); | |
3623 | ||
3624 | /* Convert (a == 0) && (b == 0) into (a | b) == 0. */ | |
3625 | if (code == TRUTH_AND_EXPR | |
3626 | && lcode == EQ_EXPR && integer_zerop (lr_arg) | |
3627 | && rcode == EQ_EXPR && integer_zerop (rr_arg) | |
3628 | && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)) | |
3629 | return build (EQ_EXPR, truth_type, | |
3630 | build (BIT_IOR_EXPR, TREE_TYPE (ll_arg), | |
3631 | ll_arg, rl_arg), | |
3632 | integer_zero_node); | |
3633 | ||
3634 | return build (code, truth_type, lhs, rhs); | |
3635 | } | |
79109eec | 3636 | |
6f725368 | 3637 | /* See if the comparisons can be merged. Then get all the parameters for |
3638 | each side. */ | |
3639 | ||
2bc77e10 | 3640 | if ((lcode != EQ_EXPR && lcode != NE_EXPR) |
6f725368 | 3641 | || (rcode != EQ_EXPR && rcode != NE_EXPR)) |
2bc77e10 | 3642 | return 0; |
3643 | ||
79109eec | 3644 | volatilep = 0; |
3645 | ll_inner = decode_field_reference (ll_arg, | |
2bc77e10 | 3646 | &ll_bitsize, &ll_bitpos, &ll_mode, |
2a6329ae | 3647 | &ll_unsignedp, &volatilep, &ll_mask, |
3648 | &ll_and_mask); | |
79109eec | 3649 | lr_inner = decode_field_reference (lr_arg, |
2bc77e10 | 3650 | &lr_bitsize, &lr_bitpos, &lr_mode, |
2a6329ae | 3651 | &lr_unsignedp, &volatilep, &lr_mask, |
3652 | &lr_and_mask); | |
79109eec | 3653 | rl_inner = decode_field_reference (rl_arg, |
2bc77e10 | 3654 | &rl_bitsize, &rl_bitpos, &rl_mode, |
2a6329ae | 3655 | &rl_unsignedp, &volatilep, &rl_mask, |
3656 | &rl_and_mask); | |
79109eec | 3657 | rr_inner = decode_field_reference (rr_arg, |
2bc77e10 | 3658 | &rr_bitsize, &rr_bitpos, &rr_mode, |
2a6329ae | 3659 | &rr_unsignedp, &volatilep, &rr_mask, |
3660 | &rr_and_mask); | |
2bc77e10 | 3661 | |
3662 | /* It must be true that the inner operation on the lhs of each | |
3663 | comparison must be the same if we are to be able to do anything. | |
3664 | Then see if we have constants. If not, the same must be true for | |
3665 | the rhs's. */ | |
3666 | if (volatilep || ll_inner == 0 || rl_inner == 0 | |
3667 | || ! operand_equal_p (ll_inner, rl_inner, 0)) | |
3668 | return 0; | |
3669 | ||
79109eec | 3670 | if (TREE_CODE (lr_arg) == INTEGER_CST |
3671 | && TREE_CODE (rr_arg) == INTEGER_CST) | |
3672 | l_const = lr_arg, r_const = rr_arg; | |
2bc77e10 | 3673 | else if (lr_inner == 0 || rr_inner == 0 |
3674 | || ! operand_equal_p (lr_inner, rr_inner, 0)) | |
3675 | return 0; | |
79109eec | 3676 | else |
3677 | l_const = r_const = 0; | |
2bc77e10 | 3678 | |
3679 | /* If either comparison code is not correct for our logical operation, | |
3680 | fail. However, we can convert a one-bit comparison against zero into | |
3681 | the opposite comparison against that bit being set in the field. */ | |
79109eec | 3682 | |
76e4a18b | 3683 | wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR); |
2bc77e10 | 3684 | if (lcode != wanted_code) |
3685 | { | |
3686 | if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask)) | |
c6107ab0 | 3687 | { |
28bb328d | 3688 | /* Make the left operand unsigned, since we are only interested |
3689 | in the value of one bit. Otherwise we are doing the wrong | |
3690 | thing below. */ | |
3691 | ll_unsignedp = 1; | |
68ae709d | 3692 | l_const = ll_mask; |
c6107ab0 | 3693 | } |
2bc77e10 | 3694 | else |
3695 | return 0; | |
3696 | } | |
3697 | ||
68ae709d | 3698 | /* This is analogous to the code for l_const above. */ |
2bc77e10 | 3699 | if (rcode != wanted_code) |
3700 | { | |
3701 | if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask)) | |
c6107ab0 | 3702 | { |
28bb328d | 3703 | rl_unsignedp = 1; |
68ae709d | 3704 | r_const = rl_mask; |
c6107ab0 | 3705 | } |
2bc77e10 | 3706 | else |
3707 | return 0; | |
3708 | } | |
3709 | ||
d50b22af | 3710 | /* After this point all optimizations will generate bit-field |
3711 | references, which we might not want. */ | |
3712 | if (! (*lang_hooks.can_use_bit_fields_p) ()) | |
3713 | return 0; | |
3714 | ||
2bc77e10 | 3715 | /* See if we can find a mode that contains both fields being compared on |
3716 | the left. If we can't, fail. Otherwise, update all constants and masks | |
3717 | to be relative to a field of that size. */ | |
3718 | first_bit = MIN (ll_bitpos, rl_bitpos); | |
3719 | end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize); | |
3720 | lnmode = get_best_mode (end_bit - first_bit, first_bit, | |
3721 | TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode, | |
3722 | volatilep); | |
3723 | if (lnmode == VOIDmode) | |
3724 | return 0; | |
3725 | ||
3726 | lnbitsize = GET_MODE_BITSIZE (lnmode); | |
3727 | lnbitpos = first_bit & ~ (lnbitsize - 1); | |
771d21fa | 3728 | lntype = (*lang_hooks.types.type_for_size) (lnbitsize, 1); |
2bc77e10 | 3729 | xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos; |
3730 | ||
51356f86 | 3731 | if (BYTES_BIG_ENDIAN) |
3732 | { | |
3733 | xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize; | |
3734 | xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize; | |
3735 | } | |
2bc77e10 | 3736 | |
ffba564c | 3737 | ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask), |
5485823f | 3738 | size_int (xll_bitpos), 0); |
ffba564c | 3739 | rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask), |
5485823f | 3740 | size_int (xrl_bitpos), 0); |
2bc77e10 | 3741 | |
2bc77e10 | 3742 | if (l_const) |
3743 | { | |
ffba564c | 3744 | l_const = convert (lntype, l_const); |
cc049fa3 | 3745 | l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask); |
94f29e88 | 3746 | l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0); |
3747 | if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const, | |
3748 | fold (build1 (BIT_NOT_EXPR, | |
ffba564c | 3749 | lntype, ll_mask)), |
94f29e88 | 3750 | 0))) |
3751 | { | |
be2828ce | 3752 | warning ("comparison is always %d", wanted_code == NE_EXPR); |
cc049fa3 | 3753 | |
94f29e88 | 3754 | return convert (truth_type, |
3755 | wanted_code == NE_EXPR | |
3756 | ? integer_one_node : integer_zero_node); | |
3757 | } | |
2bc77e10 | 3758 | } |
3759 | if (r_const) | |
3760 | { | |
ffba564c | 3761 | r_const = convert (lntype, r_const); |
2a6329ae | 3762 | r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask); |
94f29e88 | 3763 | r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0); |
3764 | if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const, | |
3765 | fold (build1 (BIT_NOT_EXPR, | |
ffba564c | 3766 | lntype, rl_mask)), |
94f29e88 | 3767 | 0))) |
3768 | { | |
be2828ce | 3769 | warning ("comparison is always %d", wanted_code == NE_EXPR); |
3770 | ||
94f29e88 | 3771 | return convert (truth_type, |
3772 | wanted_code == NE_EXPR | |
3773 | ? integer_one_node : integer_zero_node); | |
3774 | } | |
2bc77e10 | 3775 | } |
3776 | ||
3777 | /* If the right sides are not constant, do the same for it. Also, | |
3778 | disallow this optimization if a size or signedness mismatch occurs | |
3779 | between the left and right sides. */ | |
3780 | if (l_const == 0) | |
3781 | { | |
3782 | if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize | |
15e4fe21 | 3783 | || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp |
3784 | /* Make sure the two fields on the right | |
3785 | correspond to the left without being swapped. */ | |
3786 | || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos) | |
2bc77e10 | 3787 | return 0; |
3788 | ||
3789 | first_bit = MIN (lr_bitpos, rr_bitpos); | |
3790 | end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize); | |
3791 | rnmode = get_best_mode (end_bit - first_bit, first_bit, | |
3792 | TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode, | |
3793 | volatilep); | |
3794 | if (rnmode == VOIDmode) | |
3795 | return 0; | |
3796 | ||
3797 | rnbitsize = GET_MODE_BITSIZE (rnmode); | |
3798 | rnbitpos = first_bit & ~ (rnbitsize - 1); | |
771d21fa | 3799 | rntype = (*lang_hooks.types.type_for_size) (rnbitsize, 1); |
2bc77e10 | 3800 | xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos; |
3801 | ||
51356f86 | 3802 | if (BYTES_BIG_ENDIAN) |
3803 | { | |
3804 | xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize; | |
3805 | xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize; | |
3806 | } | |
2bc77e10 | 3807 | |
ffba564c | 3808 | lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask), |
5485823f | 3809 | size_int (xlr_bitpos), 0); |
ffba564c | 3810 | rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask), |
5485823f | 3811 | size_int (xrr_bitpos), 0); |
2bc77e10 | 3812 | |
3813 | /* Make a mask that corresponds to both fields being compared. | |
00ee0921 | 3814 | Do this for both items being compared. If the operands are the |
3815 | same size and the bits being compared are in the same position | |
3816 | then we can do this by masking both and comparing the masked | |
3817 | results. */ | |
5485823f | 3818 | ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0); |
3819 | lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0); | |
00ee0921 | 3820 | if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos) |
2bc77e10 | 3821 | { |
ffba564c | 3822 | lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos, |
2bc77e10 | 3823 | ll_unsignedp || rl_unsignedp); |
00ee0921 | 3824 | if (! all_ones_mask_p (ll_mask, lnbitsize)) |
3825 | lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask); | |
3826 | ||
ffba564c | 3827 | rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos, |
2bc77e10 | 3828 | lr_unsignedp || rr_unsignedp); |
00ee0921 | 3829 | if (! all_ones_mask_p (lr_mask, rnbitsize)) |
3830 | rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask); | |
3831 | ||
2bc77e10 | 3832 | return build (wanted_code, truth_type, lhs, rhs); |
3833 | } | |
3834 | ||
3835 | /* There is still another way we can do something: If both pairs of | |
3836 | fields being compared are adjacent, we may be able to make a wider | |
4cf66b97 | 3837 | field containing them both. |
3838 | ||
3839 | Note that we still must mask the lhs/rhs expressions. Furthermore, | |
cc049fa3 | 3840 | the mask must be shifted to account for the shift done by |
4cf66b97 | 3841 | make_bit_field_ref. */ |
2bc77e10 | 3842 | if ((ll_bitsize + ll_bitpos == rl_bitpos |
3843 | && lr_bitsize + lr_bitpos == rr_bitpos) | |
3844 | || (ll_bitpos == rl_bitpos + rl_bitsize | |
3845 | && lr_bitpos == rr_bitpos + rr_bitsize)) | |
4cf66b97 | 3846 | { |
ffba564c | 3847 | tree type; |
3848 | ||
3849 | lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize, | |
4cf66b97 | 3850 | MIN (ll_bitpos, rl_bitpos), ll_unsignedp); |
ffba564c | 3851 | rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize, |
3852 | MIN (lr_bitpos, rr_bitpos), lr_unsignedp); | |
3853 | ||
4cf66b97 | 3854 | ll_mask = const_binop (RSHIFT_EXPR, ll_mask, |
3855 | size_int (MIN (xll_bitpos, xrl_bitpos)), 0); | |
ffba564c | 3856 | lr_mask = const_binop (RSHIFT_EXPR, lr_mask, |
3857 | size_int (MIN (xlr_bitpos, xrr_bitpos)), 0); | |
3858 | ||
3859 | /* Convert to the smaller type before masking out unwanted bits. */ | |
3860 | type = lntype; | |
3861 | if (lntype != rntype) | |
3862 | { | |
3863 | if (lnbitsize > rnbitsize) | |
3864 | { | |
3865 | lhs = convert (rntype, lhs); | |
3866 | ll_mask = convert (rntype, ll_mask); | |
3867 | type = rntype; | |
3868 | } | |
3869 | else if (lnbitsize < rnbitsize) | |
3870 | { | |
3871 | rhs = convert (lntype, rhs); | |
3872 | lr_mask = convert (lntype, lr_mask); | |
3873 | type = lntype; | |
3874 | } | |
3875 | } | |
3876 | ||
4cf66b97 | 3877 | if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize)) |
3878 | lhs = build (BIT_AND_EXPR, type, lhs, ll_mask); | |
3879 | ||
4cf66b97 | 3880 | if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize)) |
3881 | rhs = build (BIT_AND_EXPR, type, rhs, lr_mask); | |
3882 | ||
3883 | return build (wanted_code, truth_type, lhs, rhs); | |
3884 | } | |
2bc77e10 | 3885 | |
3886 | return 0; | |
3887 | } | |
3888 | ||
3889 | /* Handle the case of comparisons with constants. If there is something in | |
3890 | common between the masks, those bits of the constants must be the same. | |
3891 | If not, the condition is always false. Test for this to avoid generating | |
3892 | incorrect code below. */ | |
5485823f | 3893 | result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0); |
2bc77e10 | 3894 | if (! integer_zerop (result) |
5485823f | 3895 | && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0), |
3896 | const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1) | |
2bc77e10 | 3897 | { |
3898 | if (wanted_code == NE_EXPR) | |
3899 | { | |
3900 | warning ("`or' of unmatched not-equal tests is always 1"); | |
3901 | return convert (truth_type, integer_one_node); | |
3902 | } | |
3903 | else | |
3904 | { | |
be2828ce | 3905 | warning ("`and' of mutually exclusive equal-tests is always 0"); |
2bc77e10 | 3906 | return convert (truth_type, integer_zero_node); |
3907 | } | |
3908 | } | |
3909 | ||
3910 | /* Construct the expression we will return. First get the component | |
3911 | reference we will make. Unless the mask is all ones the width of | |
3912 | that field, perform the mask operation. Then compare with the | |
3913 | merged constant. */ | |
ffba564c | 3914 | result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos, |
2bc77e10 | 3915 | ll_unsignedp || rl_unsignedp); |
3916 | ||
5485823f | 3917 | ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0); |
2bc77e10 | 3918 | if (! all_ones_mask_p (ll_mask, lnbitsize)) |
ffba564c | 3919 | result = build (BIT_AND_EXPR, lntype, result, ll_mask); |
2bc77e10 | 3920 | |
3921 | return build (wanted_code, truth_type, result, | |
5485823f | 3922 | const_binop (BIT_IOR_EXPR, l_const, r_const, 0)); |
2bc77e10 | 3923 | } |
3924 | \f | |
cc049fa3 | 3925 | /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a |
155b05dc | 3926 | constant. */ |
3927 | ||
3928 | static tree | |
3929 | optimize_minmax_comparison (t) | |
3930 | tree t; | |
3931 | { | |
3932 | tree type = TREE_TYPE (t); | |
3933 | tree arg0 = TREE_OPERAND (t, 0); | |
3934 | enum tree_code op_code; | |
3935 | tree comp_const = TREE_OPERAND (t, 1); | |
3936 | tree minmax_const; | |
3937 | int consts_equal, consts_lt; | |
3938 | tree inner; | |
3939 | ||
3940 | STRIP_SIGN_NOPS (arg0); | |
3941 | ||
3942 | op_code = TREE_CODE (arg0); | |
3943 | minmax_const = TREE_OPERAND (arg0, 1); | |
3944 | consts_equal = tree_int_cst_equal (minmax_const, comp_const); | |
3945 | consts_lt = tree_int_cst_lt (minmax_const, comp_const); | |
3946 | inner = TREE_OPERAND (arg0, 0); | |
3947 | ||
3948 | /* If something does not permit us to optimize, return the original tree. */ | |
3949 | if ((op_code != MIN_EXPR && op_code != MAX_EXPR) | |
3950 | || TREE_CODE (comp_const) != INTEGER_CST | |
3951 | || TREE_CONSTANT_OVERFLOW (comp_const) | |
3952 | || TREE_CODE (minmax_const) != INTEGER_CST | |
3953 | || TREE_CONSTANT_OVERFLOW (minmax_const)) | |
3954 | return t; | |
3955 | ||
3956 | /* Now handle all the various comparison codes. We only handle EQ_EXPR | |
3957 | and GT_EXPR, doing the rest with recursive calls using logical | |
3958 | simplifications. */ | |
3959 | switch (TREE_CODE (t)) | |
3960 | { | |
3961 | case NE_EXPR: case LT_EXPR: case LE_EXPR: | |
3962 | return | |
3963 | invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t))); | |
3964 | ||
3965 | case GE_EXPR: | |
3966 | return | |
3967 | fold (build (TRUTH_ORIF_EXPR, type, | |
3968 | optimize_minmax_comparison | |
3969 | (build (EQ_EXPR, type, arg0, comp_const)), | |
3970 | optimize_minmax_comparison | |
3971 | (build (GT_EXPR, type, arg0, comp_const)))); | |
3972 | ||
3973 | case EQ_EXPR: | |
3974 | if (op_code == MAX_EXPR && consts_equal) | |
3975 | /* MAX (X, 0) == 0 -> X <= 0 */ | |
3976 | return fold (build (LE_EXPR, type, inner, comp_const)); | |
3977 | ||
3978 | else if (op_code == MAX_EXPR && consts_lt) | |
3979 | /* MAX (X, 0) == 5 -> X == 5 */ | |
3980 | return fold (build (EQ_EXPR, type, inner, comp_const)); | |
3981 | ||
3982 | else if (op_code == MAX_EXPR) | |
3983 | /* MAX (X, 0) == -1 -> false */ | |
3984 | return omit_one_operand (type, integer_zero_node, inner); | |
3985 | ||
3986 | else if (consts_equal) | |
3987 | /* MIN (X, 0) == 0 -> X >= 0 */ | |
3988 | return fold (build (GE_EXPR, type, inner, comp_const)); | |
3989 | ||
3990 | else if (consts_lt) | |
3991 | /* MIN (X, 0) == 5 -> false */ | |
3992 | return omit_one_operand (type, integer_zero_node, inner); | |
3993 | ||
3994 | else | |
3995 | /* MIN (X, 0) == -1 -> X == -1 */ | |
3996 | return fold (build (EQ_EXPR, type, inner, comp_const)); | |
3997 | ||
3998 | case GT_EXPR: | |
3999 | if (op_code == MAX_EXPR && (consts_equal || consts_lt)) | |
4000 | /* MAX (X, 0) > 0 -> X > 0 | |
4001 | MAX (X, 0) > 5 -> X > 5 */ | |
4002 | return fold (build (GT_EXPR, type, inner, comp_const)); | |
4003 | ||
4004 | else if (op_code == MAX_EXPR) | |
4005 | /* MAX (X, 0) > -1 -> true */ | |
4006 | return omit_one_operand (type, integer_one_node, inner); | |
4007 | ||
4008 | else if (op_code == MIN_EXPR && (consts_equal || consts_lt)) | |
4009 | /* MIN (X, 0) > 0 -> false | |
4010 | MIN (X, 0) > 5 -> false */ | |
4011 | return omit_one_operand (type, integer_zero_node, inner); | |
4012 | ||
4013 | else | |
4014 | /* MIN (X, 0) > -1 -> X > -1 */ | |
4015 | return fold (build (GT_EXPR, type, inner, comp_const)); | |
4016 | ||
4017 | default: | |
4018 | return t; | |
4019 | } | |
4020 | } | |
4021 | \f | |
23ec2d5e | 4022 | /* T is an integer expression that is being multiplied, divided, or taken a |
4023 | modulus (CODE says which and what kind of divide or modulus) by a | |
4024 | constant C. See if we can eliminate that operation by folding it with | |
4025 | other operations already in T. WIDE_TYPE, if non-null, is a type that | |
4026 | should be used for the computation if wider than our type. | |
4027 | ||
b07ba9ff | 4028 | For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return |
4029 | (X * 2) + (Y * 4). We must, however, be assured that either the original | |
2f5cf552 | 4030 | expression would not overflow or that overflow is undefined for the type |
4031 | in the language in question. | |
4032 | ||
4033 | We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either | |
4034 | the machine has a multiply-accumulate insn or that this is part of an | |
4035 | addressing calculation. | |
23ec2d5e | 4036 | |
4037 | If we return a non-null expression, it is an equivalent form of the | |
4038 | original computation, but need not be in the original type. */ | |
4039 | ||
4040 | static tree | |
4041 | extract_muldiv (t, c, code, wide_type) | |
4042 | tree t; | |
4043 | tree c; | |
4044 | enum tree_code code; | |
4045 | tree wide_type; | |
4046 | { | |
4047 | tree type = TREE_TYPE (t); | |
4048 | enum tree_code tcode = TREE_CODE (t); | |
cc049fa3 | 4049 | tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type)) |
23ec2d5e | 4050 | > GET_MODE_SIZE (TYPE_MODE (type))) |
4051 | ? wide_type : type); | |
4052 | tree t1, t2; | |
4053 | int same_p = tcode == code; | |
03435587 | 4054 | tree op0 = NULL_TREE, op1 = NULL_TREE; |
23ec2d5e | 4055 | |
4056 | /* Don't deal with constants of zero here; they confuse the code below. */ | |
4057 | if (integer_zerop (c)) | |
2f5cf552 | 4058 | return NULL_TREE; |
23ec2d5e | 4059 | |
4060 | if (TREE_CODE_CLASS (tcode) == '1') | |
4061 | op0 = TREE_OPERAND (t, 0); | |
4062 | ||
4063 | if (TREE_CODE_CLASS (tcode) == '2') | |
4064 | op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1); | |
4065 | ||
4066 | /* Note that we need not handle conditional operations here since fold | |
4067 | already handles those cases. So just do arithmetic here. */ | |
4068 | switch (tcode) | |
4069 | { | |
4070 | case INTEGER_CST: | |
4071 | /* For a constant, we can always simplify if we are a multiply | |
4072 | or (for divide and modulus) if it is a multiple of our constant. */ | |
4073 | if (code == MULT_EXPR | |
4074 | || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0))) | |
4075 | return const_binop (code, convert (ctype, t), convert (ctype, c), 0); | |
4076 | break; | |
4077 | ||
4078 | case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR: | |
12480406 | 4079 | /* If op0 is an expression ... */ |
3cb1a3c6 | 4080 | if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<' |
4081 | || TREE_CODE_CLASS (TREE_CODE (op0)) == '1' | |
4082 | || TREE_CODE_CLASS (TREE_CODE (op0)) == '2' | |
4083 | || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e') | |
12480406 | 4084 | /* ... and is unsigned, and its type is smaller than ctype, |
4085 | then we cannot pass through as widening. */ | |
4086 | && ((TREE_UNSIGNED (TREE_TYPE (op0)) | |
4087 | && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE | |
4088 | && TYPE_IS_SIZETYPE (TREE_TYPE (op0))) | |
4089 | && (GET_MODE_SIZE (TYPE_MODE (ctype)) | |
4090 | > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))) | |
4091 | /* ... or its type is larger than ctype, | |
4092 | then we cannot pass through this truncation. */ | |
4093 | || (GET_MODE_SIZE (TYPE_MODE (ctype)) | |
4094 | < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))) | |
3cb1a3c6 | 4095 | break; |
4096 | ||
23ec2d5e | 4097 | /* Pass the constant down and see if we can make a simplification. If |
5f0002b0 | 4098 | we can, replace this expression with the inner simplification for |
4099 | possible later conversion to our or some other type. */ | |
23ec2d5e | 4100 | if (0 != (t1 = extract_muldiv (op0, convert (TREE_TYPE (op0), c), code, |
4101 | code == MULT_EXPR ? ctype : NULL_TREE))) | |
4102 | return t1; | |
4103 | break; | |
4104 | ||
4105 | case NEGATE_EXPR: case ABS_EXPR: | |
4106 | if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0) | |
4107 | return fold (build1 (tcode, ctype, convert (ctype, t1))); | |
4108 | break; | |
4109 | ||
4110 | case MIN_EXPR: case MAX_EXPR: | |
6269027b | 4111 | /* If widening the type changes the signedness, then we can't perform |
4112 | this optimization as that changes the result. */ | |
3cb1a3c6 | 4113 | if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type)) |
6269027b | 4114 | break; |
4115 | ||
23ec2d5e | 4116 | /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */ |
4117 | if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0 | |
4118 | && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0) | |
5f0002b0 | 4119 | { |
4120 | if (tree_int_cst_sgn (c) < 0) | |
4121 | tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR); | |
4122 | ||
4123 | return fold (build (tcode, ctype, convert (ctype, t1), | |
4124 | convert (ctype, t2))); | |
4125 | } | |
23ec2d5e | 4126 | break; |
4127 | ||
4128 | case WITH_RECORD_EXPR: | |
4129 | if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0) | |
4130 | return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1, | |
4131 | TREE_OPERAND (t, 1)); | |
4132 | break; | |
4133 | ||
4134 | case SAVE_EXPR: | |
5f0002b0 | 4135 | /* If this has not been evaluated and the operand has no side effects, |
4136 | we can see if we can do something inside it and make a new one. | |
4137 | Note that this test is overly conservative since we can do this | |
4138 | if the only reason it had side effects is that it was another | |
4139 | similar SAVE_EXPR, but that isn't worth bothering with. */ | |
4140 | if (SAVE_EXPR_RTL (t) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)) | |
23ec2d5e | 4141 | && 0 != (t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, |
4142 | wide_type))) | |
fe1302cf | 4143 | { |
4144 | t1 = save_expr (t1); | |
4145 | if (SAVE_EXPR_PERSISTENT_P (t) && TREE_CODE (t1) == SAVE_EXPR) | |
4146 | SAVE_EXPR_PERSISTENT_P (t1) = 1; | |
4147 | if (is_pending_size (t)) | |
4148 | put_pending_size (t1); | |
4149 | return t1; | |
4150 | } | |
23ec2d5e | 4151 | break; |
4152 | ||
4153 | case LSHIFT_EXPR: case RSHIFT_EXPR: | |
4154 | /* If the second operand is constant, this is a multiplication | |
4155 | or floor division, by a power of two, so we can treat it that | |
4156 | way unless the multiplier or divisor overflows. */ | |
4157 | if (TREE_CODE (op1) == INTEGER_CST | |
c011f821 | 4158 | /* const_binop may not detect overflow correctly, |
4159 | so check for it explicitly here. */ | |
4160 | && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1) | |
4161 | && TREE_INT_CST_HIGH (op1) == 0 | |
23ec2d5e | 4162 | && 0 != (t1 = convert (ctype, |
4163 | const_binop (LSHIFT_EXPR, size_one_node, | |
4164 | op1, 0))) | |
4165 | && ! TREE_OVERFLOW (t1)) | |
4166 | return extract_muldiv (build (tcode == LSHIFT_EXPR | |
4167 | ? MULT_EXPR : FLOOR_DIV_EXPR, | |
4168 | ctype, convert (ctype, op0), t1), | |
4169 | c, code, wide_type); | |
4170 | break; | |
4171 | ||
4172 | case PLUS_EXPR: case MINUS_EXPR: | |
4173 | /* See if we can eliminate the operation on both sides. If we can, we | |
4174 | can return a new PLUS or MINUS. If we can't, the only remaining | |
4175 | cases where we can do anything are if the second operand is a | |
4176 | constant. */ | |
4177 | t1 = extract_muldiv (op0, c, code, wide_type); | |
4178 | t2 = extract_muldiv (op1, c, code, wide_type); | |
17e3940f | 4179 | if (t1 != 0 && t2 != 0 |
4180 | && (code == MULT_EXPR | |
4181 | /* If not multiplication, we can only do this if either operand | |
4182 | is divisible by c. */ | |
4183 | || multiple_of_p (ctype, op0, c) | |
4184 | || multiple_of_p (ctype, op1, c))) | |
23ec2d5e | 4185 | return fold (build (tcode, ctype, convert (ctype, t1), |
4186 | convert (ctype, t2))); | |
23ec2d5e | 4187 | |
5f0002b0 | 4188 | /* If this was a subtraction, negate OP1 and set it to be an addition. |
4189 | This simplifies the logic below. */ | |
4190 | if (tcode == MINUS_EXPR) | |
4191 | tcode = PLUS_EXPR, op1 = negate_expr (op1); | |
4192 | ||
ec4d93b0 | 4193 | if (TREE_CODE (op1) != INTEGER_CST) |
4194 | break; | |
4195 | ||
5f0002b0 | 4196 | /* If either OP1 or C are negative, this optimization is not safe for |
4197 | some of the division and remainder types while for others we need | |
4198 | to change the code. */ | |
4199 | if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0) | |
4200 | { | |
4201 | if (code == CEIL_DIV_EXPR) | |
4202 | code = FLOOR_DIV_EXPR; | |
5f0002b0 | 4203 | else if (code == FLOOR_DIV_EXPR) |
4204 | code = CEIL_DIV_EXPR; | |
b575bb01 | 4205 | else if (code != MULT_EXPR |
4206 | && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR) | |
5f0002b0 | 4207 | break; |
4208 | } | |
4209 | ||
98248b34 | 4210 | /* If it's a multiply or a division/modulus operation of a multiple |
4211 | of our constant, do the operation and verify it doesn't overflow. */ | |
4212 | if (code == MULT_EXPR | |
4213 | || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0))) | |
d3371fcd | 4214 | { |
4215 | op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0); | |
4216 | if (op1 == 0 || TREE_OVERFLOW (op1)) | |
4217 | break; | |
4218 | } | |
98248b34 | 4219 | else |
d3371fcd | 4220 | break; |
5f0002b0 | 4221 | |
fc452262 | 4222 | /* If we have an unsigned type is not a sizetype, we cannot widen |
4223 | the operation since it will change the result if the original | |
4224 | computation overflowed. */ | |
4225 | if (TREE_UNSIGNED (ctype) | |
d490e2f2 | 4226 | && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)) |
fc452262 | 4227 | && ctype != type) |
4228 | break; | |
4229 | ||
23ec2d5e | 4230 | /* If we were able to eliminate our operation from the first side, |
5f0002b0 | 4231 | apply our operation to the second side and reform the PLUS. */ |
4232 | if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR)) | |
4233 | return fold (build (tcode, ctype, convert (ctype, t1), op1)); | |
23ec2d5e | 4234 | |
4235 | /* The last case is if we are a multiply. In that case, we can | |
4236 | apply the distributive law to commute the multiply and addition | |
6312a35e | 4237 | if the multiplication of the constants doesn't overflow. */ |
5f0002b0 | 4238 | if (code == MULT_EXPR) |
23ec2d5e | 4239 | return fold (build (tcode, ctype, fold (build (code, ctype, |
4240 | convert (ctype, op0), | |
4241 | convert (ctype, c))), | |
5f0002b0 | 4242 | op1)); |
23ec2d5e | 4243 | |
4244 | break; | |
4245 | ||
4246 | case MULT_EXPR: | |
4247 | /* We have a special case here if we are doing something like | |
4248 | (C * 8) % 4 since we know that's zero. */ | |
4249 | if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR | |
4250 | || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR) | |
4251 | && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST | |
4252 | && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0))) | |
4253 | return omit_one_operand (type, integer_zero_node, op0); | |
4254 | ||
6312a35e | 4255 | /* ... fall through ... */ |
23ec2d5e | 4256 | |
4257 | case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR: | |
4258 | case ROUND_DIV_EXPR: case EXACT_DIV_EXPR: | |
4259 | /* If we can extract our operation from the LHS, do so and return a | |
4260 | new operation. Likewise for the RHS from a MULT_EXPR. Otherwise, | |
4261 | do something only if the second operand is a constant. */ | |
4262 | if (same_p | |
4263 | && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0) | |
4264 | return fold (build (tcode, ctype, convert (ctype, t1), | |
4265 | convert (ctype, op1))); | |
4266 | else if (tcode == MULT_EXPR && code == MULT_EXPR | |
4267 | && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0) | |
4268 | return fold (build (tcode, ctype, convert (ctype, op0), | |
4269 | convert (ctype, t1))); | |
4270 | else if (TREE_CODE (op1) != INTEGER_CST) | |
4271 | return 0; | |
4272 | ||
4273 | /* If these are the same operation types, we can associate them | |
4274 | assuming no overflow. */ | |
4275 | if (tcode == code | |
4276 | && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1), | |
4277 | convert (ctype, c), 0)) | |
4278 | && ! TREE_OVERFLOW (t1)) | |
4279 | return fold (build (tcode, ctype, convert (ctype, op0), t1)); | |
4280 | ||
4281 | /* If these operations "cancel" each other, we have the main | |
4282 | optimizations of this pass, which occur when either constant is a | |
4283 | multiple of the other, in which case we replace this with either an | |
cc049fa3 | 4284 | operation or CODE or TCODE. |
2f5cf552 | 4285 | |
35a3065a | 4286 | If we have an unsigned type that is not a sizetype, we cannot do |
2f5cf552 | 4287 | this since it will change the result if the original computation |
4288 | overflowed. */ | |
4289 | if ((! TREE_UNSIGNED (ctype) | |
d490e2f2 | 4290 | || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))) |
2f5cf552 | 4291 | && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR) |
4292 | || (tcode == MULT_EXPR | |
4293 | && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR | |
4294 | && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR))) | |
23ec2d5e | 4295 | { |
4296 | if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0))) | |
4297 | return fold (build (tcode, ctype, convert (ctype, op0), | |
4298 | convert (ctype, | |
4299 | const_binop (TRUNC_DIV_EXPR, | |
4300 | op1, c, 0)))); | |
4301 | else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0))) | |
4302 | return fold (build (code, ctype, convert (ctype, op0), | |
4303 | convert (ctype, | |
4304 | const_binop (TRUNC_DIV_EXPR, | |
4305 | c, op1, 0)))); | |
4306 | } | |
4307 | break; | |
4308 | ||
4309 | default: | |
4310 | break; | |
4311 | } | |
4312 | ||
4313 | return 0; | |
4314 | } | |
4315 | \f | |
58a718ca | 4316 | /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate |
4317 | S, a SAVE_EXPR, return the expression actually being evaluated. Note | |
4318 | that we may sometimes modify the tree. */ | |
4319 | ||
4320 | static tree | |
4321 | strip_compound_expr (t, s) | |
4322 | tree t; | |
4323 | tree s; | |
4324 | { | |
58a718ca | 4325 | enum tree_code code = TREE_CODE (t); |
4326 | ||
4327 | /* See if this is the COMPOUND_EXPR we want to eliminate. */ | |
4328 | if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR | |
4329 | && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s) | |
4330 | return TREE_OPERAND (t, 1); | |
4331 | ||
4332 | /* See if this is a COND_EXPR or a simple arithmetic operator. We | |
4333 | don't bother handling any other types. */ | |
4334 | else if (code == COND_EXPR) | |
4335 | { | |
4336 | TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s); | |
4337 | TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s); | |
4338 | TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s); | |
4339 | } | |
4340 | else if (TREE_CODE_CLASS (code) == '1') | |
4341 | TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s); | |
4342 | else if (TREE_CODE_CLASS (code) == '<' | |
4343 | || TREE_CODE_CLASS (code) == '2') | |
4344 | { | |
4345 | TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s); | |
4346 | TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s); | |
4347 | } | |
4348 | ||
4349 | return t; | |
4350 | } | |
4351 | \f | |
b4af30fd | 4352 | /* Return a node which has the indicated constant VALUE (either 0 or |
4353 | 1), and is of the indicated TYPE. */ | |
4354 | ||
1704bc4a | 4355 | static tree |
b4af30fd | 4356 | constant_boolean_node (value, type) |
4357 | int value; | |
4358 | tree type; | |
4359 | { | |
4360 | if (type == integer_type_node) | |
4361 | return value ? integer_one_node : integer_zero_node; | |
4362 | else if (TREE_CODE (type) == BOOLEAN_TYPE) | |
aff9e656 | 4363 | return (*lang_hooks.truthvalue_conversion) (value ? integer_one_node : |
4364 | integer_zero_node); | |
cc049fa3 | 4365 | else |
b4af30fd | 4366 | { |
4367 | tree t = build_int_2 (value, 0); | |
083a2b5e | 4368 | |
b4af30fd | 4369 | TREE_TYPE (t) = type; |
4370 | return t; | |
4371 | } | |
4372 | } | |
4373 | ||
be2828ce | 4374 | /* Utility function for the following routine, to see how complex a nesting of |
4375 | COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which | |
4376 | we don't care (to avoid spending too much time on complex expressions.). */ | |
4377 | ||
4378 | static int | |
4379 | count_cond (expr, lim) | |
4380 | tree expr; | |
4381 | int lim; | |
4382 | { | |
9c811526 | 4383 | int ctrue, cfalse; |
be2828ce | 4384 | |
4385 | if (TREE_CODE (expr) != COND_EXPR) | |
4386 | return 0; | |
4387 | else if (lim <= 0) | |
4388 | return 0; | |
4389 | ||
9c811526 | 4390 | ctrue = count_cond (TREE_OPERAND (expr, 1), lim - 1); |
4391 | cfalse = count_cond (TREE_OPERAND (expr, 2), lim - 1 - ctrue); | |
4392 | return MIN (lim, 1 + ctrue + cfalse); | |
be2828ce | 4393 | } |
47cbd05d | 4394 | |
203a24c4 | 4395 | /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'. |
47cbd05d | 4396 | Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here |
4397 | CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)' | |
6ef828f9 | 4398 | expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the |
47cbd05d | 4399 | COND is the first argument to CODE; otherwise (as in the example |
4400 | given here), it is the second argument. TYPE is the type of the | |
4401 | original expression. */ | |
4402 | ||
4403 | static tree | |
4404 | fold_binary_op_with_conditional_arg (code, type, cond, arg, cond_first_p) | |
4405 | enum tree_code code; | |
4406 | tree type; | |
4407 | tree cond; | |
4408 | tree arg; | |
4409 | int cond_first_p; | |
4410 | { | |
4411 | tree test, true_value, false_value; | |
4412 | tree lhs = NULL_TREE; | |
4413 | tree rhs = NULL_TREE; | |
4414 | /* In the end, we'll produce a COND_EXPR. Both arms of the | |
4415 | conditional expression will be binary operations. The left-hand | |
4416 | side of the expression to be executed if the condition is true | |
4417 | will be pointed to by TRUE_LHS. Similarly, the right-hand side | |
4418 | of the expression to be executed if the condition is true will be | |
cb0ccc1e | 4419 | pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous -- |
47cbd05d | 4420 | but apply to the expression to be executed if the conditional is |
4421 | false. */ | |
4422 | tree *true_lhs; | |
4423 | tree *true_rhs; | |
4424 | tree *false_lhs; | |
4425 | tree *false_rhs; | |
4426 | /* These are the codes to use for the left-hand side and right-hand | |
4427 | side of the COND_EXPR. Normally, they are the same as CODE. */ | |
4428 | enum tree_code lhs_code = code; | |
4429 | enum tree_code rhs_code = code; | |
4430 | /* And these are the types of the expressions. */ | |
4431 | tree lhs_type = type; | |
4432 | tree rhs_type = type; | |
4433 | ||
4434 | if (cond_first_p) | |
4435 | { | |
4436 | true_rhs = false_rhs = &arg; | |
4437 | true_lhs = &true_value; | |
4438 | false_lhs = &false_value; | |
4439 | } | |
4440 | else | |
4441 | { | |
4442 | true_lhs = false_lhs = &arg; | |
4443 | true_rhs = &true_value; | |
4444 | false_rhs = &false_value; | |
4445 | } | |
4446 | ||
4447 | if (TREE_CODE (cond) == COND_EXPR) | |
4448 | { | |
4449 | test = TREE_OPERAND (cond, 0); | |
4450 | true_value = TREE_OPERAND (cond, 1); | |
4451 | false_value = TREE_OPERAND (cond, 2); | |
4452 | /* If this operand throws an expression, then it does not make | |
4453 | sense to try to perform a logical or arithmetic operation | |
4454 | involving it. Instead of building `a + throw 3' for example, | |
4455 | we simply build `a, throw 3'. */ | |
4456 | if (VOID_TYPE_P (TREE_TYPE (true_value))) | |
4457 | { | |
4458 | lhs_code = COMPOUND_EXPR; | |
4459 | if (!cond_first_p) | |
4460 | lhs_type = void_type_node; | |
4461 | } | |
4462 | if (VOID_TYPE_P (TREE_TYPE (false_value))) | |
4463 | { | |
4464 | rhs_code = COMPOUND_EXPR; | |
4465 | if (!cond_first_p) | |
4466 | rhs_type = void_type_node; | |
4467 | } | |
4468 | } | |
4469 | else | |
4470 | { | |
4471 | tree testtype = TREE_TYPE (cond); | |
4472 | test = cond; | |
4473 | true_value = convert (testtype, integer_one_node); | |
4474 | false_value = convert (testtype, integer_zero_node); | |
4475 | } | |
d3371fcd | 4476 | |
47cbd05d | 4477 | /* If ARG is complex we want to make sure we only evaluate |
4478 | it once. Though this is only required if it is volatile, it | |
4479 | might be more efficient even if it is not. However, if we | |
4480 | succeed in folding one part to a constant, we do not need | |
4481 | to make this SAVE_EXPR. Since we do this optimization | |
4482 | primarily to see if we do end up with constant and this | |
4483 | SAVE_EXPR interferes with later optimizations, suppressing | |
4484 | it when we can is important. | |
d3371fcd | 4485 | |
47cbd05d | 4486 | If we are not in a function, we can't make a SAVE_EXPR, so don't |
4487 | try to do so. Don't try to see if the result is a constant | |
4488 | if an arm is a COND_EXPR since we get exponential behavior | |
4489 | in that case. */ | |
d3371fcd | 4490 | |
47cbd05d | 4491 | if (TREE_CODE (arg) != SAVE_EXPR && ! TREE_CONSTANT (arg) |
20325f61 | 4492 | && (*lang_hooks.decls.global_bindings_p) () == 0 |
47cbd05d | 4493 | && ((TREE_CODE (arg) != VAR_DECL |
4494 | && TREE_CODE (arg) != PARM_DECL) | |
4495 | || TREE_SIDE_EFFECTS (arg))) | |
4496 | { | |
4497 | if (TREE_CODE (true_value) != COND_EXPR) | |
4498 | lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs)); | |
d3371fcd | 4499 | |
47cbd05d | 4500 | if (TREE_CODE (false_value) != COND_EXPR) |
4501 | rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs)); | |
d3371fcd | 4502 | |
47cbd05d | 4503 | if ((lhs == 0 || ! TREE_CONSTANT (lhs)) |
4504 | && (rhs == 0 || !TREE_CONSTANT (rhs))) | |
4505 | arg = save_expr (arg), lhs = rhs = 0; | |
4506 | } | |
d3371fcd | 4507 | |
47cbd05d | 4508 | if (lhs == 0) |
4509 | lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs)); | |
4510 | if (rhs == 0) | |
4511 | rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs)); | |
d3371fcd | 4512 | |
47cbd05d | 4513 | test = fold (build (COND_EXPR, type, test, lhs, rhs)); |
d3371fcd | 4514 | |
47cbd05d | 4515 | if (TREE_CODE (arg) == SAVE_EXPR) |
4516 | return build (COMPOUND_EXPR, type, | |
4517 | convert (void_type_node, arg), | |
4518 | strip_compound_expr (test, arg)); | |
4519 | else | |
4520 | return convert (type, test); | |
4521 | } | |
4522 | ||
be2828ce | 4523 | \f |
920d0fb5 | 4524 | /* Subroutine of fold() that checks for the addition of +/- 0.0. |
4525 | ||
4526 | If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type | |
4527 | TYPE, X + ADDEND is the same as X. If NEGATE, return true if X - | |
4528 | ADDEND is the same as X. | |
4529 | ||
6ef828f9 | 4530 | X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero |
920d0fb5 | 4531 | and finite. The problematic cases are when X is zero, and its mode |
4532 | has signed zeros. In the case of rounding towards -infinity, | |
4533 | X - 0 is not the same as X because 0 - 0 is -0. In other rounding | |
4534 | modes, X + 0 is not the same as X because -0 + 0 is 0. */ | |
4535 | ||
4536 | static bool | |
4537 | fold_real_zero_addition_p (type, addend, negate) | |
4538 | tree type, addend; | |
4539 | int negate; | |
4540 | { | |
4541 | if (!real_zerop (addend)) | |
4542 | return false; | |
4543 | ||
4544 | /* Allow the fold if zeros aren't signed, or their sign isn't important. */ | |
4545 | if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))) | |
4546 | return true; | |
4547 | ||
4548 | /* Treat x + -0 as x - 0 and x - -0 as x + 0. */ | |
4549 | if (TREE_CODE (addend) == REAL_CST | |
4550 | && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend))) | |
4551 | negate = !negate; | |
4552 | ||
4553 | /* The mode has signed zeros, and we have to honor their sign. | |
4554 | In this situation, there is only one case we can return true for. | |
4555 | X - 0 is the same as X unless rounding towards -infinity is | |
4556 | supported. */ | |
4557 | return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type)); | |
4558 | } | |
4559 | ||
4560 | ||
2bc77e10 | 4561 | /* Perform constant folding and related simplification of EXPR. |
4562 | The related simplifications include x*1 => x, x*0 => 0, etc., | |
4563 | and application of the associative law. | |
4564 | NOP_EXPR conversions may be removed freely (as long as we | |
4565 | are careful not to change the C type of the overall expression) | |
4566 | We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR, | |
4567 | but we can constant-fold them if they have constant operands. */ | |
4568 | ||
4569 | tree | |
cc049fa3 | 4570 | fold (expr) |
2bc77e10 | 4571 | tree expr; |
4572 | { | |
19cb6b50 | 4573 | tree t = expr; |
2bc77e10 | 4574 | tree t1 = NULL_TREE; |
e233264a | 4575 | tree tem; |
2bc77e10 | 4576 | tree type = TREE_TYPE (expr); |
19cb6b50 | 4577 | tree arg0 = NULL_TREE, arg1 = NULL_TREE; |
4578 | enum tree_code code = TREE_CODE (t); | |
4579 | int kind = TREE_CODE_CLASS (code); | |
e233264a | 4580 | int invert; |
2bc77e10 | 4581 | /* WINS will be nonzero when the switch is done |
4582 | if all operands are constant. */ | |
2bc77e10 | 4583 | int wins = 1; |
4584 | ||
cc049fa3 | 4585 | /* Don't try to process an RTL_EXPR since its operands aren't trees. |
14a7560f | 4586 | Likewise for a SAVE_EXPR that's already been evaluated. */ |
e4ad77f8 | 4587 | if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0)) |
e9d8d238 | 4588 | return t; |
4589 | ||
8541c166 | 4590 | /* Return right away if a constant. */ |
4591 | if (kind == 'c') | |
4592 | return t; | |
cc049fa3 | 4593 | |
32a0589f | 4594 | #ifdef MAX_INTEGER_COMPUTATION_MODE |
4595 | check_max_integer_computation_mode (expr); | |
4596 | #endif | |
4597 | ||
233c0cbd | 4598 | if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR) |
4599 | { | |
bb6b5123 | 4600 | tree subop; |
4601 | ||
233c0cbd | 4602 | /* Special case for conversion ops that can have fixed point args. */ |
4603 | arg0 = TREE_OPERAND (t, 0); | |
4604 | ||
4605 | /* Don't use STRIP_NOPS, because signedness of argument type matters. */ | |
4606 | if (arg0 != 0) | |
155b05dc | 4607 | STRIP_SIGN_NOPS (arg0); |
233c0cbd | 4608 | |
bb6b5123 | 4609 | if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST) |
4610 | subop = TREE_REALPART (arg0); | |
4611 | else | |
4612 | subop = arg0; | |
4613 | ||
4614 | if (subop != 0 && TREE_CODE (subop) != INTEGER_CST | |
bb6b5123 | 4615 | && TREE_CODE (subop) != REAL_CST |
233c0cbd | 4616 | ) |
4617 | /* Note that TREE_CONSTANT isn't enough: | |
4618 | static var addresses are constant but we can't | |
4619 | do arithmetic on them. */ | |
4620 | wins = 0; | |
4621 | } | |
3f1e707c | 4622 | else if (IS_EXPR_CODE_CLASS (kind) || kind == 'r') |
2bc77e10 | 4623 | { |
19cb6b50 | 4624 | int len = first_rtl_op (code); |
4625 | int i; | |
2bc77e10 | 4626 | for (i = 0; i < len; i++) |
4627 | { | |
4628 | tree op = TREE_OPERAND (t, i); | |
bb6b5123 | 4629 | tree subop; |
2bc77e10 | 4630 | |
4631 | if (op == 0) | |
4632 | continue; /* Valid for CALL_EXPR, at least. */ | |
4633 | ||
c2cbd9a8 | 4634 | if (kind == '<' || code == RSHIFT_EXPR) |
4635 | { | |
4636 | /* Signedness matters here. Perhaps we can refine this | |
4637 | later. */ | |
155b05dc | 4638 | STRIP_SIGN_NOPS (op); |
c2cbd9a8 | 4639 | } |
4640 | else | |
3a6656ad | 4641 | /* Strip any conversions that don't change the mode. */ |
4642 | STRIP_NOPS (op); | |
cc049fa3 | 4643 | |
bb6b5123 | 4644 | if (TREE_CODE (op) == COMPLEX_CST) |
4645 | subop = TREE_REALPART (op); | |
4646 | else | |
4647 | subop = op; | |
4648 | ||
4649 | if (TREE_CODE (subop) != INTEGER_CST | |
4268f174 | 4650 | && TREE_CODE (subop) != REAL_CST) |
2bc77e10 | 4651 | /* Note that TREE_CONSTANT isn't enough: |
4652 | static var addresses are constant but we can't | |
4653 | do arithmetic on them. */ | |
4654 | wins = 0; | |
4655 | ||
4656 | if (i == 0) | |
4657 | arg0 = op; | |
4658 | else if (i == 1) | |
4659 | arg1 = op; | |
4660 | } | |
4661 | } | |
4662 | ||
4663 | /* If this is a commutative operation, and ARG0 is a constant, move it | |
4664 | to ARG1 to reduce the number of tests below. */ | |
4665 | if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR | |
4666 | || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR | |
4667 | || code == BIT_AND_EXPR) | |
4668 | && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)) | |
4669 | { | |
e233264a | 4670 | tem = arg0; arg0 = arg1; arg1 = tem; |
2bc77e10 | 4671 | |
e233264a | 4672 | tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1); |
4673 | TREE_OPERAND (t, 1) = tem; | |
2bc77e10 | 4674 | } |
4675 | ||
4676 | /* Now WINS is set as described above, | |
4677 | ARG0 is the first operand of EXPR, | |
4678 | and ARG1 is the second operand (if it has more than one operand). | |
4679 | ||
4680 | First check for cases where an arithmetic operation is applied to a | |
4681 | compound, conditional, or comparison operation. Push the arithmetic | |
4682 | operation inside the compound or conditional to see if any folding | |
4683 | can then be done. Convert comparison to conditional for this purpose. | |
4684 | The also optimizes non-constant cases that used to be done in | |
b5ab1edd | 4685 | expand_expr. |
4686 | ||
ea7a28cf | 4687 | Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR, |
8b94828f | 4688 | one of the operands is a comparison and the other is a comparison, a |
4689 | BIT_AND_EXPR with the constant 1, or a truth value. In that case, the | |
4690 | code below would make the expression more complex. Change it to a | |
cc049fa3 | 4691 | TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to |
5c0dba00 | 4692 | TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */ |
b5ab1edd | 4693 | |
5c0dba00 | 4694 | if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR |
4695 | || code == EQ_EXPR || code == NE_EXPR) | |
8b94828f | 4696 | && ((truth_value_p (TREE_CODE (arg0)) |
4697 | && (truth_value_p (TREE_CODE (arg1)) | |
b5ab1edd | 4698 | || (TREE_CODE (arg1) == BIT_AND_EXPR |
4699 | && integer_onep (TREE_OPERAND (arg1, 1))))) | |
8b94828f | 4700 | || (truth_value_p (TREE_CODE (arg1)) |
4701 | && (truth_value_p (TREE_CODE (arg0)) | |
b5ab1edd | 4702 | || (TREE_CODE (arg0) == BIT_AND_EXPR |
4703 | && integer_onep (TREE_OPERAND (arg0, 1))))))) | |
5c0dba00 | 4704 | { |
4705 | t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR | |
4706 | : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR | |
4707 | : TRUTH_XOR_EXPR, | |
4708 | type, arg0, arg1)); | |
4709 | ||
4710 | if (code == EQ_EXPR) | |
4711 | t = invert_truthvalue (t); | |
4712 | ||
4713 | return t; | |
4714 | } | |
b5ab1edd | 4715 | |
2bc77e10 | 4716 | if (TREE_CODE_CLASS (code) == '1') |
4717 | { | |
4718 | if (TREE_CODE (arg0) == COMPOUND_EXPR) | |
4719 | return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0), | |
4720 | fold (build1 (code, type, TREE_OPERAND (arg0, 1)))); | |
4721 | else if (TREE_CODE (arg0) == COND_EXPR) | |
abd9ac9c | 4722 | { |
4723 | t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0), | |
4724 | fold (build1 (code, type, TREE_OPERAND (arg0, 1))), | |
4725 | fold (build1 (code, type, TREE_OPERAND (arg0, 2))))); | |
4726 | ||
4727 | /* If this was a conversion, and all we did was to move into | |
2483911d | 4728 | inside the COND_EXPR, bring it back out. But leave it if |
4729 | it is a conversion from integer to integer and the | |
4730 | result precision is no wider than a word since such a | |
4731 | conversion is cheap and may be optimized away by combine, | |
4732 | while it couldn't if it were outside the COND_EXPR. Then return | |
4733 | so we don't get into an infinite recursion loop taking the | |
4734 | conversion out and then back in. */ | |
abd9ac9c | 4735 | |
4736 | if ((code == NOP_EXPR || code == CONVERT_EXPR | |
4737 | || code == NON_LVALUE_EXPR) | |
4738 | && TREE_CODE (t) == COND_EXPR | |
4739 | && TREE_CODE (TREE_OPERAND (t, 1)) == code | |
6e23378f | 4740 | && TREE_CODE (TREE_OPERAND (t, 2)) == code |
4741 | && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0)) | |
2483911d | 4742 | == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0))) |
4743 | && ! (INTEGRAL_TYPE_P (TREE_TYPE (t)) | |
083a2b5e | 4744 | && (INTEGRAL_TYPE_P |
4745 | (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0)))) | |
2483911d | 4746 | && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD)) |
abd9ac9c | 4747 | t = build1 (code, type, |
4748 | build (COND_EXPR, | |
083a2b5e | 4749 | TREE_TYPE (TREE_OPERAND |
4750 | (TREE_OPERAND (t, 1), 0)), | |
abd9ac9c | 4751 | TREE_OPERAND (t, 0), |
4752 | TREE_OPERAND (TREE_OPERAND (t, 1), 0), | |
4753 | TREE_OPERAND (TREE_OPERAND (t, 2), 0))); | |
4754 | return t; | |
4755 | } | |
cc049fa3 | 4756 | else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<') |
2bc77e10 | 4757 | return fold (build (COND_EXPR, type, arg0, |
4758 | fold (build1 (code, type, integer_one_node)), | |
4759 | fold (build1 (code, type, integer_zero_node)))); | |
4760 | } | |
b5ab1edd | 4761 | else if (TREE_CODE_CLASS (code) == '2' |
4762 | || TREE_CODE_CLASS (code) == '<') | |
2bc77e10 | 4763 | { |
4764 | if (TREE_CODE (arg1) == COMPOUND_EXPR) | |
4765 | return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0), | |
b5ab1edd | 4766 | fold (build (code, type, |
4767 | arg0, TREE_OPERAND (arg1, 1)))); | |
90a73592 | 4768 | else if ((TREE_CODE (arg1) == COND_EXPR |
4769 | || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<' | |
4770 | && TREE_CODE_CLASS (code) != '<')) | |
be2828ce | 4771 | && (TREE_CODE (arg0) != COND_EXPR |
4772 | || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25) | |
9e042f31 | 4773 | && (! TREE_SIDE_EFFECTS (arg0) |
20325f61 | 4774 | || ((*lang_hooks.decls.global_bindings_p) () == 0 |
9e042f31 | 4775 | && ! contains_placeholder_p (arg0)))) |
d3371fcd | 4776 | return |
47cbd05d | 4777 | fold_binary_op_with_conditional_arg (code, type, arg1, arg0, |
4778 | /*cond_first_p=*/0); | |
2bc77e10 | 4779 | else if (TREE_CODE (arg0) == COMPOUND_EXPR) |
4780 | return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0), | |
4781 | fold (build (code, type, TREE_OPERAND (arg0, 1), arg1))); | |
90a73592 | 4782 | else if ((TREE_CODE (arg0) == COND_EXPR |
4783 | || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<' | |
4784 | && TREE_CODE_CLASS (code) != '<')) | |
be2828ce | 4785 | && (TREE_CODE (arg1) != COND_EXPR |
4786 | || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25) | |
9e042f31 | 4787 | && (! TREE_SIDE_EFFECTS (arg1) |
20325f61 | 4788 | || ((*lang_hooks.decls.global_bindings_p) () == 0 |
9e042f31 | 4789 | && ! contains_placeholder_p (arg1)))) |
d3371fcd | 4790 | return |
47cbd05d | 4791 | fold_binary_op_with_conditional_arg (code, type, arg0, arg1, |
4792 | /*cond_first_p=*/1); | |
2bc77e10 | 4793 | } |
e233264a | 4794 | else if (TREE_CODE_CLASS (code) == '<' |
4795 | && TREE_CODE (arg0) == COMPOUND_EXPR) | |
4796 | return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0), | |
4797 | fold (build (code, type, TREE_OPERAND (arg0, 1), arg1))); | |
4798 | else if (TREE_CODE_CLASS (code) == '<' | |
4799 | && TREE_CODE (arg1) == COMPOUND_EXPR) | |
4800 | return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0), | |
4801 | fold (build (code, type, arg0, TREE_OPERAND (arg1, 1)))); | |
cc049fa3 | 4802 | |
2bc77e10 | 4803 | switch (code) |
4804 | { | |
4805 | case INTEGER_CST: | |
4806 | case REAL_CST: | |
886cfd4f | 4807 | case VECTOR_CST: |
2bc77e10 | 4808 | case STRING_CST: |
4809 | case COMPLEX_CST: | |
4810 | case CONSTRUCTOR: | |
4811 | return t; | |
4812 | ||
4813 | case CONST_DECL: | |
4814 | return fold (DECL_INITIAL (t)); | |
4815 | ||
4816 | case NOP_EXPR: | |
4817 | case FLOAT_EXPR: | |
4818 | case CONVERT_EXPR: | |
4819 | case FIX_TRUNC_EXPR: | |
4820 | /* Other kinds of FIX are not handled properly by fold_convert. */ | |
4c608263 | 4821 | |
2483911d | 4822 | if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t)) |
4823 | return TREE_OPERAND (t, 0); | |
4824 | ||
fa4ebe56 | 4825 | /* Handle cases of two conversions in a row. */ |
4826 | if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR | |
4827 | || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR) | |
4828 | { | |
4829 | tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)); | |
4830 | tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0)); | |
4831 | tree final_type = TREE_TYPE (t); | |
4832 | int inside_int = INTEGRAL_TYPE_P (inside_type); | |
cc58e392 | 4833 | int inside_ptr = POINTER_TYPE_P (inside_type); |
fa4ebe56 | 4834 | int inside_float = FLOAT_TYPE_P (inside_type); |
02e7a332 | 4835 | unsigned int inside_prec = TYPE_PRECISION (inside_type); |
fa4ebe56 | 4836 | int inside_unsignedp = TREE_UNSIGNED (inside_type); |
4837 | int inter_int = INTEGRAL_TYPE_P (inter_type); | |
cc58e392 | 4838 | int inter_ptr = POINTER_TYPE_P (inter_type); |
fa4ebe56 | 4839 | int inter_float = FLOAT_TYPE_P (inter_type); |
02e7a332 | 4840 | unsigned int inter_prec = TYPE_PRECISION (inter_type); |
fa4ebe56 | 4841 | int inter_unsignedp = TREE_UNSIGNED (inter_type); |
4842 | int final_int = INTEGRAL_TYPE_P (final_type); | |
cc58e392 | 4843 | int final_ptr = POINTER_TYPE_P (final_type); |
fa4ebe56 | 4844 | int final_float = FLOAT_TYPE_P (final_type); |
02e7a332 | 4845 | unsigned int final_prec = TYPE_PRECISION (final_type); |
fa4ebe56 | 4846 | int final_unsignedp = TREE_UNSIGNED (final_type); |
4847 | ||
cc049fa3 | 4848 | /* In addition to the cases of two conversions in a row |
fa4ebe56 | 4849 | handled below, if we are converting something to its own |
4850 | type via an object of identical or wider precision, neither | |
4851 | conversion is needed. */ | |
0c9a39fe | 4852 | if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (final_type) |
fa4ebe56 | 4853 | && ((inter_int && final_int) || (inter_float && final_float)) |
4854 | && inter_prec >= final_prec) | |
39ab05ed | 4855 | return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0)); |
fa4ebe56 | 4856 | |
4857 | /* Likewise, if the intermediate and final types are either both | |
4858 | float or both integer, we don't need the middle conversion if | |
4859 | it is wider than the final type and doesn't change the signedness | |
cc58e392 | 4860 | (for integers). Avoid this if the final type is a pointer |
7cf60649 | 4861 | since then we sometimes need the inner conversion. Likewise if |
4862 | the outer has a precision not equal to the size of its mode. */ | |
fa4ebe56 | 4863 | if ((((inter_int || inter_ptr) && (inside_int || inside_ptr)) |
4864 | || (inter_float && inside_float)) | |
4865 | && inter_prec >= inside_prec | |
cc58e392 | 4866 | && (inter_float || inter_unsignedp == inside_unsignedp) |
7cf60649 | 4867 | && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type)) |
4868 | && TYPE_MODE (final_type) == TYPE_MODE (inter_type)) | |
cc58e392 | 4869 | && ! final_ptr) |
fa4ebe56 | 4870 | return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0)); |
4871 | ||
6800ce58 | 4872 | /* If we have a sign-extension of a zero-extended value, we can |
4873 | replace that by a single zero-extension. */ | |
4874 | if (inside_int && inter_int && final_int | |
4875 | && inside_prec < inter_prec && inter_prec < final_prec | |
4876 | && inside_unsignedp && !inter_unsignedp) | |
4877 | return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0)); | |
4878 | ||
fa4ebe56 | 4879 | /* Two conversions in a row are not needed unless: |
4880 | - some conversion is floating-point (overstrict for now), or | |
4881 | - the intermediate type is narrower than both initial and | |
4882 | final, or | |
4883 | - the intermediate type and innermost type differ in signedness, | |
4884 | and the outermost type is wider than the intermediate, or | |
4885 | - the initial type is a pointer type and the precisions of the | |
4886 | intermediate and final types differ, or | |
cc049fa3 | 4887 | - the final type is a pointer type and the precisions of the |
fa4ebe56 | 4888 | initial and intermediate types differ. */ |
4889 | if (! inside_float && ! inter_float && ! final_float | |
4890 | && (inter_prec > inside_prec || inter_prec > final_prec) | |
4891 | && ! (inside_int && inter_int | |
4892 | && inter_unsignedp != inside_unsignedp | |
4893 | && inter_prec < final_prec) | |
4894 | && ((inter_unsignedp && inter_prec > inside_prec) | |
4895 | == (final_unsignedp && final_prec > inter_prec)) | |
4896 | && ! (inside_ptr && inter_prec != final_prec) | |
7cf60649 | 4897 | && ! (final_ptr && inside_prec != inter_prec) |
4898 | && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type)) | |
4899 | && TYPE_MODE (final_type) == TYPE_MODE (inter_type)) | |
4900 | && ! final_ptr) | |
fa4ebe56 | 4901 | return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0)); |
4902 | } | |
2bc77e10 | 4903 | |
4904 | if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR | |
e70afa40 | 4905 | && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) |
4906 | /* Detect assigning a bitfield. */ | |
4907 | && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF | |
4908 | && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1)))) | |
2bc77e10 | 4909 | { |
e70afa40 | 4910 | /* Don't leave an assignment inside a conversion |
eb2f80f3 | 4911 | unless assigning a bitfield. */ |
2bc77e10 | 4912 | tree prev = TREE_OPERAND (t, 0); |
4913 | TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1); | |
4914 | /* First do the assignment, then return converted constant. */ | |
4915 | t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t)); | |
4916 | TREE_USED (t) = 1; | |
4917 | return t; | |
4918 | } | |
4c342eac | 4919 | |
4920 | /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer | |
4921 | constants (if x has signed type, the sign bit cannot be set | |
4922 | in c). This folds extension into the BIT_AND_EXPR. */ | |
4923 | if (INTEGRAL_TYPE_P (TREE_TYPE (t)) | |
7effcd30 | 4924 | && TREE_CODE (TREE_TYPE (t)) != BOOLEAN_TYPE |
4c342eac | 4925 | && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR |
4926 | && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST) | |
4927 | { | |
4928 | tree and = TREE_OPERAND (t, 0); | |
4929 | tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1); | |
4930 | int change = 0; | |
4931 | ||
4932 | if (TREE_UNSIGNED (TREE_TYPE (and)) | |
4933 | || (TYPE_PRECISION (TREE_TYPE (t)) | |
4934 | <= TYPE_PRECISION (TREE_TYPE (and)))) | |
4935 | change = 1; | |
4936 | else if (TYPE_PRECISION (TREE_TYPE (and1)) | |
4937 | <= HOST_BITS_PER_WIDE_INT | |
4938 | && host_integerp (and1, 1)) | |
4939 | { | |
4940 | unsigned HOST_WIDE_INT cst; | |
4941 | ||
4942 | cst = tree_low_cst (and1, 1); | |
4943 | cst &= (HOST_WIDE_INT) -1 | |
4944 | << (TYPE_PRECISION (TREE_TYPE (and1)) - 1); | |
4945 | change = (cst == 0); | |
4946 | #ifdef LOAD_EXTEND_OP | |
4947 | if (change | |
4948 | && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0))) | |
4949 | == ZERO_EXTEND)) | |
4950 | { | |
6a7078b0 | 4951 | tree uns = (*lang_hooks.types.unsigned_type) (TREE_TYPE (and0)); |
4c342eac | 4952 | and0 = convert (uns, and0); |
4953 | and1 = convert (uns, and1); | |
4954 | } | |
4955 | #endif | |
4956 | } | |
4957 | if (change) | |
4958 | return fold (build (BIT_AND_EXPR, TREE_TYPE (t), | |
4959 | convert (TREE_TYPE (t), and0), | |
4960 | convert (TREE_TYPE (t), and1))); | |
4961 | } | |
4962 | ||
2bc77e10 | 4963 | if (!wins) |
4964 | { | |
4965 | TREE_CONSTANT (t) = TREE_CONSTANT (arg0); | |
4966 | return t; | |
4967 | } | |
4968 | return fold_convert (t, arg0); | |
4969 | ||
f96c43fb | 4970 | case VIEW_CONVERT_EXPR: |
4971 | if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR) | |
4972 | return build1 (VIEW_CONVERT_EXPR, type, | |
4973 | TREE_OPERAND (TREE_OPERAND (t, 0), 0)); | |
4974 | return t; | |
4975 | ||
09a738e9 | 4976 | case COMPONENT_REF: |
4977 | if (TREE_CODE (arg0) == CONSTRUCTOR) | |
f5541a8b | 4978 | { |
4979 | tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0)); | |
4980 | if (m) | |
4981 | t = TREE_VALUE (m); | |
4982 | } | |
09a738e9 | 4983 | return t; |
4984 | ||
2bc77e10 | 4985 | case RANGE_EXPR: |
4986 | TREE_CONSTANT (t) = wins; | |
4987 | return t; | |
4988 | ||
4989 | case NEGATE_EXPR: | |
4990 | if (wins) | |
4991 | { | |
4992 | if (TREE_CODE (arg0) == INTEGER_CST) | |
4993 | { | |
4491f79f | 4994 | unsigned HOST_WIDE_INT low; |
4995 | HOST_WIDE_INT high; | |
b9e999f0 | 4996 | int overflow = neg_double (TREE_INT_CST_LOW (arg0), |
4997 | TREE_INT_CST_HIGH (arg0), | |
4998 | &low, &high); | |
4999 | t = build_int_2 (low, high); | |
2bc77e10 | 5000 | TREE_TYPE (t) = type; |
f17f1965 | 5001 | TREE_OVERFLOW (t) |
5002 | = (TREE_OVERFLOW (arg0) | |
3f430a71 | 5003 | | force_fit_type (t, overflow && !TREE_UNSIGNED (type))); |
f17f1965 | 5004 | TREE_CONSTANT_OVERFLOW (t) |
5005 | = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0); | |
2bc77e10 | 5006 | } |
5007 | else if (TREE_CODE (arg0) == REAL_CST) | |
5008 | t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0))); | |
2bc77e10 | 5009 | } |
5010 | else if (TREE_CODE (arg0) == NEGATE_EXPR) | |
5011 | return TREE_OPERAND (arg0, 0); | |
5012 | ||
5013 | /* Convert - (a - b) to (b - a) for non-floating-point. */ | |
23ec2d5e | 5014 | else if (TREE_CODE (arg0) == MINUS_EXPR |
7f3be425 | 5015 | && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)) |
2bc77e10 | 5016 | return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1), |
5017 | TREE_OPERAND (arg0, 0)); | |
5018 | ||
5019 | return t; | |
5020 | ||
5021 | case ABS_EXPR: | |
5022 | if (wins) | |
5023 | { | |
5024 | if (TREE_CODE (arg0) == INTEGER_CST) | |
5025 | { | |
43dd9cb8 | 5026 | /* If the value is unsigned, then the absolute value is |
5027 | the same as the ordinary value. */ | |
5028 | if (TREE_UNSIGNED (type)) | |
5029 | return arg0; | |
5030 | /* Similarly, if the value is non-negative. */ | |
5031 | else if (INT_CST_LT (integer_minus_one_node, arg0)) | |
5032 | return arg0; | |
5033 | /* If the value is negative, then the absolute value is | |
5034 | its negation. */ | |
5035 | else | |
2bc77e10 | 5036 | { |
4491f79f | 5037 | unsigned HOST_WIDE_INT low; |
5038 | HOST_WIDE_INT high; | |
f52f18a3 | 5039 | int overflow = neg_double (TREE_INT_CST_LOW (arg0), |
5040 | TREE_INT_CST_HIGH (arg0), | |
5041 | &low, &high); | |
5042 | t = build_int_2 (low, high); | |
5043 | TREE_TYPE (t) = type; | |
f17f1965 | 5044 | TREE_OVERFLOW (t) |
5045 | = (TREE_OVERFLOW (arg0) | |
f55401f0 | 5046 | | force_fit_type (t, overflow)); |
f17f1965 | 5047 | TREE_CONSTANT_OVERFLOW (t) |
5048 | = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0); | |
2bc77e10 | 5049 | } |
5050 | } | |
5051 | else if (TREE_CODE (arg0) == REAL_CST) | |
5052 | { | |
e233264a | 5053 | if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0))) |
2bc77e10 | 5054 | t = build_real (type, |
5055 | REAL_VALUE_NEGATE (TREE_REAL_CST (arg0))); | |
5056 | } | |
2bc77e10 | 5057 | } |
5058 | else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR) | |
5059 | return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)); | |
5060 | return t; | |
5061 | ||
03aa4df2 | 5062 | case CONJ_EXPR: |
5063 | if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE) | |
3a6656ad | 5064 | return convert (type, arg0); |
03aa4df2 | 5065 | else if (TREE_CODE (arg0) == COMPLEX_EXPR) |
64a83102 | 5066 | return build (COMPLEX_EXPR, type, |
03aa4df2 | 5067 | TREE_OPERAND (arg0, 0), |
23ec2d5e | 5068 | negate_expr (TREE_OPERAND (arg0, 1))); |
03aa4df2 | 5069 | else if (TREE_CODE (arg0) == COMPLEX_CST) |
8b3ab5d0 | 5070 | return build_complex (type, TREE_REALPART (arg0), |
5071 | negate_expr (TREE_IMAGPART (arg0))); | |
03aa4df2 | 5072 | else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR) |
5073 | return fold (build (TREE_CODE (arg0), type, | |
5074 | fold (build1 (CONJ_EXPR, type, | |
5075 | TREE_OPERAND (arg0, 0))), | |
5076 | fold (build1 (CONJ_EXPR, | |
5077 | type, TREE_OPERAND (arg0, 1))))); | |
5078 | else if (TREE_CODE (arg0) == CONJ_EXPR) | |
5079 | return TREE_OPERAND (arg0, 0); | |
5080 | return t; | |
5081 | ||
2bc77e10 | 5082 | case BIT_NOT_EXPR: |
5083 | if (wins) | |
5084 | { | |
a3f1e3ec | 5085 | t = build_int_2 (~ TREE_INT_CST_LOW (arg0), |
5086 | ~ TREE_INT_CST_HIGH (arg0)); | |
2bc77e10 | 5087 | TREE_TYPE (t) = type; |
f55401f0 | 5088 | force_fit_type (t, 0); |
f17f1965 | 5089 | TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0); |
b9e999f0 | 5090 | TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0); |
2bc77e10 | 5091 | } |
5092 | else if (TREE_CODE (arg0) == BIT_NOT_EXPR) | |
5093 | return TREE_OPERAND (arg0, 0); | |
5094 | return t; | |
5095 | ||
5096 | case PLUS_EXPR: | |
5097 | /* A + (-B) -> A - B */ | |
5098 | if (TREE_CODE (arg1) == NEGATE_EXPR) | |
5099 | return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0))); | |
88b41b10 | 5100 | /* (-A) + B -> B - A */ |
5101 | if (TREE_CODE (arg0) == NEGATE_EXPR) | |
5102 | return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0))); | |
780a4395 | 5103 | else if (! FLOAT_TYPE_P (type)) |
2bc77e10 | 5104 | { |
5105 | if (integer_zerop (arg1)) | |
5106 | return non_lvalue (convert (type, arg0)); | |
5107 | ||
5108 | /* If we are adding two BIT_AND_EXPR's, both of which are and'ing | |
5109 | with a constant, and the two constants have no bits in common, | |
5110 | we should treat this as a BIT_IOR_EXPR since this may produce more | |
5111 | simplifications. */ | |
5112 | if (TREE_CODE (arg0) == BIT_AND_EXPR | |
5113 | && TREE_CODE (arg1) == BIT_AND_EXPR | |
5114 | && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST | |
5115 | && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST | |
5116 | && integer_zerop (const_binop (BIT_AND_EXPR, | |
5117 | TREE_OPERAND (arg0, 1), | |
5485823f | 5118 | TREE_OPERAND (arg1, 1), 0))) |
2bc77e10 | 5119 | { |
5120 | code = BIT_IOR_EXPR; | |
5121 | goto bit_ior; | |
5122 | } | |
e4142c0f | 5123 | |
578e821c | 5124 | /* Reassociate (plus (plus (mult) (foo)) (mult)) as |
cc049fa3 | 5125 | (plus (plus (mult) (mult)) (foo)) so that we can |
578e821c | 5126 | take advantage of the factoring cases below. */ |
5127 | if ((TREE_CODE (arg0) == PLUS_EXPR | |
5128 | && TREE_CODE (arg1) == MULT_EXPR) | |
5129 | || (TREE_CODE (arg1) == PLUS_EXPR | |
cc049fa3 | 5130 | && TREE_CODE (arg0) == MULT_EXPR)) |
578e821c | 5131 | { |
5132 | tree parg0, parg1, parg, marg; | |
5133 | ||
5134 | if (TREE_CODE (arg0) == PLUS_EXPR) | |
5135 | parg = arg0, marg = arg1; | |
5136 | else | |
5137 | parg = arg1, marg = arg0; | |
5138 | parg0 = TREE_OPERAND (parg, 0); | |
5139 | parg1 = TREE_OPERAND (parg, 1); | |
5140 | STRIP_NOPS (parg0); | |
5141 | STRIP_NOPS (parg1); | |
5142 | ||
5143 | if (TREE_CODE (parg0) == MULT_EXPR | |
5144 | && TREE_CODE (parg1) != MULT_EXPR) | |
5145 | return fold (build (PLUS_EXPR, type, | |
5146 | fold (build (PLUS_EXPR, type, parg0, marg)), | |
5147 | parg1)); | |
5148 | if (TREE_CODE (parg0) != MULT_EXPR | |
5149 | && TREE_CODE (parg1) == MULT_EXPR) | |
5150 | return fold (build (PLUS_EXPR, type, | |
5151 | fold (build (PLUS_EXPR, type, parg1, marg)), | |
5152 | parg0)); | |
5153 | } | |
5154 | ||
1d322a97 | 5155 | if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR) |
5156 | { | |
5157 | tree arg00, arg01, arg10, arg11; | |
5b7dad94 | 5158 | tree alt0 = NULL_TREE, alt1 = NULL_TREE, same; |
1d322a97 | 5159 | |
5160 | /* (A * C) + (B * C) -> (A+B) * C. | |
5161 | We are most concerned about the case where C is a constant, | |
5162 | but other combinations show up during loop reduction. Since | |
5163 | it is not difficult, try all four possibilities. */ | |
5164 | ||
5165 | arg00 = TREE_OPERAND (arg0, 0); | |
5166 | arg01 = TREE_OPERAND (arg0, 1); | |
5167 | arg10 = TREE_OPERAND (arg1, 0); | |
5168 | arg11 = TREE_OPERAND (arg1, 1); | |
5169 | same = NULL_TREE; | |
5170 | ||
5171 | if (operand_equal_p (arg01, arg11, 0)) | |
5172 | same = arg01, alt0 = arg00, alt1 = arg10; | |
5173 | else if (operand_equal_p (arg00, arg10, 0)) | |
5174 | same = arg00, alt0 = arg01, alt1 = arg11; | |
5175 | else if (operand_equal_p (arg00, arg11, 0)) | |
5176 | same = arg00, alt0 = arg01, alt1 = arg10; | |
5177 | else if (operand_equal_p (arg01, arg10, 0)) | |
5178 | same = arg01, alt0 = arg00, alt1 = arg11; | |
5179 | ||
578e821c | 5180 | /* No identical multiplicands; see if we can find a common |
5181 | power-of-two factor in non-power-of-two multiplies. This | |
5182 | can help in multi-dimensional array access. */ | |
5183 | else if (TREE_CODE (arg01) == INTEGER_CST | |
5184 | && TREE_CODE (arg11) == INTEGER_CST | |
5185 | && TREE_INT_CST_HIGH (arg01) == 0 | |
5186 | && TREE_INT_CST_HIGH (arg11) == 0) | |
5187 | { | |
5188 | HOST_WIDE_INT int01, int11, tmp; | |
5189 | int01 = TREE_INT_CST_LOW (arg01); | |
5190 | int11 = TREE_INT_CST_LOW (arg11); | |
5191 | ||
5192 | /* Move min of absolute values to int11. */ | |
5193 | if ((int01 >= 0 ? int01 : -int01) | |
5194 | < (int11 >= 0 ? int11 : -int11)) | |
5195 | { | |
5196 | tmp = int01, int01 = int11, int11 = tmp; | |
5197 | alt0 = arg00, arg00 = arg10, arg10 = alt0; | |
5198 | alt0 = arg01, arg01 = arg11, arg11 = alt0; | |
5199 | } | |
5200 | ||
5201 | if (exact_log2 (int11) > 0 && int01 % int11 == 0) | |
5202 | { | |
5203 | alt0 = fold (build (MULT_EXPR, type, arg00, | |
5204 | build_int_2 (int01 / int11, 0))); | |
5205 | alt1 = arg10; | |
5206 | same = arg11; | |
5207 | } | |
5208 | } | |
5209 | ||
1d322a97 | 5210 | if (same) |
cc049fa3 | 5211 | return fold (build (MULT_EXPR, type, |
1d322a97 | 5212 | fold (build (PLUS_EXPR, type, alt0, alt1)), |
5213 | same)); | |
5214 | } | |
2bc77e10 | 5215 | } |
920d0fb5 | 5216 | |
5217 | /* See if ARG1 is zero and X + ARG1 reduces to X. */ | |
5218 | else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0)) | |
88b41b10 | 5219 | return non_lvalue (convert (type, arg0)); |
5220 | ||
920d0fb5 | 5221 | /* Likewise if the operands are reversed. */ |
5222 | else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0)) | |
5223 | return non_lvalue (convert (type, arg1)); | |
5224 | ||
0e1e143e | 5225 | bit_rotate: |
5226 | /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A | |
5227 | is a rotate of A by C1 bits. */ | |
5228 | /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A | |
5229 | is a rotate of A by B bits. */ | |
5230 | { | |
19cb6b50 | 5231 | enum tree_code code0, code1; |
cc049fa3 | 5232 | code0 = TREE_CODE (arg0); |
5233 | code1 = TREE_CODE (arg1); | |
5234 | if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR) | |
5235 | || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR)) | |
0e1e143e | 5236 | && operand_equal_p (TREE_OPERAND (arg0, 0), |
cc049fa3 | 5237 | TREE_OPERAND (arg1, 0), 0) |
0e1e143e | 5238 | && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0)))) |
5239 | { | |
19cb6b50 | 5240 | tree tree01, tree11; |
5241 | enum tree_code code01, code11; | |
0e1e143e | 5242 | |
5243 | tree01 = TREE_OPERAND (arg0, 1); | |
5244 | tree11 = TREE_OPERAND (arg1, 1); | |
5245 | STRIP_NOPS (tree01); | |
5246 | STRIP_NOPS (tree11); | |
5247 | code01 = TREE_CODE (tree01); | |
5248 | code11 = TREE_CODE (tree11); | |
5249 | if (code01 == INTEGER_CST | |
cc049fa3 | 5250 | && code11 == INTEGER_CST |
5251 | && TREE_INT_CST_HIGH (tree01) == 0 | |
5252 | && TREE_INT_CST_HIGH (tree11) == 0 | |
5253 | && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11)) | |
5254 | == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))) | |
0e1e143e | 5255 | return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0), |
cc049fa3 | 5256 | code0 == LSHIFT_EXPR ? tree01 : tree11); |
0e1e143e | 5257 | else if (code11 == MINUS_EXPR) |
5258 | { | |
cc049fa3 | 5259 | tree tree110, tree111; |
5260 | tree110 = TREE_OPERAND (tree11, 0); | |
5261 | tree111 = TREE_OPERAND (tree11, 1); | |
5262 | STRIP_NOPS (tree110); | |
5263 | STRIP_NOPS (tree111); | |
5264 | if (TREE_CODE (tree110) == INTEGER_CST | |
a0c2c45b | 5265 | && 0 == compare_tree_int (tree110, |
5266 | TYPE_PRECISION | |
5267 | (TREE_TYPE (TREE_OPERAND | |
5268 | (arg0, 0)))) | |
0e1e143e | 5269 | && operand_equal_p (tree01, tree111, 0)) |
cc049fa3 | 5270 | return build ((code0 == LSHIFT_EXPR |
5271 | ? LROTATE_EXPR | |
5272 | : RROTATE_EXPR), | |
5273 | type, TREE_OPERAND (arg0, 0), tree01); | |
0e1e143e | 5274 | } |
5275 | else if (code01 == MINUS_EXPR) | |
5276 | { | |
cc049fa3 | 5277 | tree tree010, tree011; |
5278 | tree010 = TREE_OPERAND (tree01, 0); | |
5279 | tree011 = TREE_OPERAND (tree01, 1); | |
5280 | STRIP_NOPS (tree010); | |
5281 | STRIP_NOPS (tree011); | |
5282 | if (TREE_CODE (tree010) == INTEGER_CST | |
a0c2c45b | 5283 | && 0 == compare_tree_int (tree010, |
5284 | TYPE_PRECISION | |
5285 | (TREE_TYPE (TREE_OPERAND | |
5286 | (arg0, 0)))) | |
0e1e143e | 5287 | && operand_equal_p (tree11, tree011, 0)) |
cc049fa3 | 5288 | return build ((code0 != LSHIFT_EXPR |
5289 | ? LROTATE_EXPR | |
5290 | : RROTATE_EXPR), | |
5291 | type, TREE_OPERAND (arg0, 0), tree11); | |
0e1e143e | 5292 | } |
5293 | } | |
5294 | } | |
88b41b10 | 5295 | |
2bc77e10 | 5296 | associate: |
23ec2d5e | 5297 | /* In most languages, can't associate operations on floats through |
5298 | parentheses. Rather than remember where the parentheses were, we | |
5299 | don't associate floats at all. It shouldn't matter much. However, | |
5300 | associating multiplications is only very slightly inaccurate, so do | |
7f3be425 | 5301 | that if -funsafe-math-optimizations is specified. */ |
23ec2d5e | 5302 | |
5303 | if (! wins | |
5304 | && (! FLOAT_TYPE_P (type) | |
7f3be425 | 5305 | || (flag_unsafe_math_optimizations && code == MULT_EXPR))) |
2bc77e10 | 5306 | { |
b07ba9ff | 5307 | tree var0, con0, lit0, minus_lit0; |
5308 | tree var1, con1, lit1, minus_lit1; | |
23ec2d5e | 5309 | |
5310 | /* Split both trees into variables, constants, and literals. Then | |
5311 | associate each group together, the constants with literals, | |
5312 | then the result with variables. This increases the chances of | |
5313 | literals being recombined later and of generating relocatable | |
6312a35e | 5314 | expressions for the sum of a constant and literal. */ |
b07ba9ff | 5315 | var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0); |
5316 | var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1, | |
5317 | code == MINUS_EXPR); | |
23ec2d5e | 5318 | |
5319 | /* Only do something if we found more than two objects. Otherwise, | |
5320 | nothing has changed and we risk infinite recursion. */ | |
b07ba9ff | 5321 | if (2 < ((var0 != 0) + (var1 != 0) |
5322 | + (con0 != 0) + (con1 != 0) | |
5323 | + (lit0 != 0) + (lit1 != 0) | |
5324 | + (minus_lit0 != 0) + (minus_lit1 != 0))) | |
2bc77e10 | 5325 | { |
b07ba9ff | 5326 | /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */ |
5327 | if (code == MINUS_EXPR) | |
5328 | code = PLUS_EXPR; | |
5329 | ||
23ec2d5e | 5330 | var0 = associate_trees (var0, var1, code, type); |
5331 | con0 = associate_trees (con0, con1, code, type); | |
5332 | lit0 = associate_trees (lit0, lit1, code, type); | |
b07ba9ff | 5333 | minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type); |
5334 | ||
5335 | /* Preserve the MINUS_EXPR if the negative part of the literal is | |
5336 | greater than the positive part. Otherwise, the multiplicative | |
5337 | folding code (i.e extract_muldiv) may be fooled in case | |
5338 | unsigned constants are substracted, like in the following | |
5339 | example: ((X*2 + 4) - 8U)/2. */ | |
5340 | if (minus_lit0 && lit0) | |
5341 | { | |
5342 | if (tree_int_cst_lt (lit0, minus_lit0)) | |
5343 | { | |
5344 | minus_lit0 = associate_trees (minus_lit0, lit0, | |
5345 | MINUS_EXPR, type); | |
5346 | lit0 = 0; | |
5347 | } | |
5348 | else | |
5349 | { | |
5350 | lit0 = associate_trees (lit0, minus_lit0, | |
5351 | MINUS_EXPR, type); | |
5352 | minus_lit0 = 0; | |
5353 | } | |
5354 | } | |
5355 | if (minus_lit0) | |
5356 | { | |
5357 | if (con0 == 0) | |
5358 | return convert (type, associate_trees (var0, minus_lit0, | |
5359 | MINUS_EXPR, type)); | |
5360 | else | |
5361 | { | |
5362 | con0 = associate_trees (con0, minus_lit0, | |
5363 | MINUS_EXPR, type); | |
5364 | return convert (type, associate_trees (var0, con0, | |
5365 | PLUS_EXPR, type)); | |
5366 | } | |
5367 | } | |
5368 | ||
23ec2d5e | 5369 | con0 = associate_trees (con0, lit0, code, type); |
5370 | return convert (type, associate_trees (var0, con0, code, type)); | |
2bc77e10 | 5371 | } |
5372 | } | |
23ec2d5e | 5373 | |
2bc77e10 | 5374 | binary: |
2bc77e10 | 5375 | if (wins) |
5485823f | 5376 | t1 = const_binop (code, arg0, arg1, 0); |
2bc77e10 | 5377 | if (t1 != NULL_TREE) |
5378 | { | |
5379 | /* The return value should always have | |
5380 | the same type as the original expression. */ | |
a3f1e3ec | 5381 | if (TREE_TYPE (t1) != TREE_TYPE (t)) |
5382 | t1 = convert (TREE_TYPE (t), t1); | |
5383 | ||
2bc77e10 | 5384 | return t1; |
5385 | } | |
5386 | return t; | |
5387 | ||
5388 | case MINUS_EXPR: | |
88b41b10 | 5389 | /* A - (-B) -> A + B */ |
5390 | if (TREE_CODE (arg1) == NEGATE_EXPR) | |
5391 | return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0))); | |
5392 | /* (-A) - CST -> (-CST) - A for floating point (what about ints ?) */ | |
5393 | if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST) | |
5394 | return | |
cc049fa3 | 5395 | fold (build (MINUS_EXPR, type, |
88b41b10 | 5396 | build_real (TREE_TYPE (arg1), |
5397 | REAL_VALUE_NEGATE (TREE_REAL_CST (arg1))), | |
5398 | TREE_OPERAND (arg0, 0))); | |
5399 | ||
780a4395 | 5400 | if (! FLOAT_TYPE_P (type)) |
2bc77e10 | 5401 | { |
5402 | if (! wins && integer_zerop (arg0)) | |
18bea959 | 5403 | return negate_expr (convert (type, arg1)); |
2bc77e10 | 5404 | if (integer_zerop (arg1)) |
5405 | return non_lvalue (convert (type, arg0)); | |
e4142c0f | 5406 | |
5407 | /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned | |
5408 | about the case where C is a constant, just try one of the | |
5409 | four possibilities. */ | |
5410 | ||
5411 | if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR | |
5412 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
5413 | TREE_OPERAND (arg1, 1), 0)) | |
5414 | return fold (build (MULT_EXPR, type, | |
5415 | fold (build (MINUS_EXPR, type, | |
5416 | TREE_OPERAND (arg0, 0), | |
5417 | TREE_OPERAND (arg1, 0))), | |
5418 | TREE_OPERAND (arg0, 1))); | |
2bc77e10 | 5419 | } |
8045c7c3 | 5420 | |
920d0fb5 | 5421 | /* See if ARG1 is zero and X - ARG1 reduces to X. */ |
5422 | else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1)) | |
5423 | return non_lvalue (convert (type, arg0)); | |
5424 | ||
5425 | /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether | |
5426 | ARG0 is zero and X + ARG0 reduces to X, since that would mean | |
5427 | (-ARG1 + ARG0) reduces to -ARG1. */ | |
5428 | else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0)) | |
5429 | return negate_expr (convert (type, arg1)); | |
b2c6bec0 | 5430 | |
cc049fa3 | 5431 | /* Fold &x - &x. This can happen from &x.foo - &x. |
8045c7c3 | 5432 | This is unsafe for certain floats even in non-IEEE formats. |
5433 | In IEEE, it is unsafe because it does wrong for NaNs. | |
5434 | Also note that operand_equal_p is always false if an operand | |
5435 | is volatile. */ | |
5436 | ||
7f3be425 | 5437 | if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations) |
d3d5ed2a | 5438 | && operand_equal_p (arg0, arg1, 0)) |
8045c7c3 | 5439 | return convert (type, integer_zero_node); |
b2c6bec0 | 5440 | |
2bc77e10 | 5441 | goto associate; |
5442 | ||
5443 | case MULT_EXPR: | |
88b41b10 | 5444 | /* (-A) * (-B) -> A * B */ |
5445 | if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR) | |
5446 | return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0), | |
cc049fa3 | 5447 | TREE_OPERAND (arg1, 0))); |
88b41b10 | 5448 | |
780a4395 | 5449 | if (! FLOAT_TYPE_P (type)) |
2bc77e10 | 5450 | { |
5451 | if (integer_zerop (arg1)) | |
5452 | return omit_one_operand (type, arg1, arg0); | |
5453 | if (integer_onep (arg1)) | |
5454 | return non_lvalue (convert (type, arg0)); | |
5455 | ||
5456 | /* (a * (1 << b)) is (a << b) */ | |
5457 | if (TREE_CODE (arg1) == LSHIFT_EXPR | |
5458 | && integer_onep (TREE_OPERAND (arg1, 0))) | |
5459 | return fold (build (LSHIFT_EXPR, type, arg0, | |
5460 | TREE_OPERAND (arg1, 1))); | |
5461 | if (TREE_CODE (arg0) == LSHIFT_EXPR | |
5462 | && integer_onep (TREE_OPERAND (arg0, 0))) | |
5463 | return fold (build (LSHIFT_EXPR, type, arg1, | |
5464 | TREE_OPERAND (arg0, 1))); | |
23ec2d5e | 5465 | |
5466 | if (TREE_CODE (arg1) == INTEGER_CST | |
5467 | && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1, | |
5468 | code, NULL_TREE))) | |
5469 | return convert (type, tem); | |
5470 | ||
2bc77e10 | 5471 | } |
2bc77e10 | 5472 | else |
5473 | { | |
920d0fb5 | 5474 | /* Maybe fold x * 0 to 0. The expressions aren't the same |
5475 | when x is NaN, since x * 0 is also NaN. Nor are they the | |
5476 | same in modes with signed zeros, since multiplying a | |
5477 | negative value by 0 gives -0, not +0. */ | |
5478 | if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))) | |
5479 | && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0))) | |
2bc77e10 | 5480 | && real_zerop (arg1)) |
5481 | return omit_one_operand (type, arg1, arg0); | |
0a8176f3 | 5482 | /* In IEEE floating point, x*1 is not equivalent to x for snans. */ |
5483 | if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))) | |
5484 | && real_onep (arg1)) | |
2bc77e10 | 5485 | return non_lvalue (convert (type, arg0)); |
19fe5401 | 5486 | |
0a8176f3 | 5487 | /* Transform x * -1.0 into -x. */ |
5488 | if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))) | |
19fe5401 | 5489 | && real_minus_onep (arg1)) |
5490 | return fold (build1 (NEGATE_EXPR, type, arg0)); | |
5491 | ||
2bc77e10 | 5492 | /* x*2 is x+x */ |
20325f61 | 5493 | if (! wins && real_twop (arg1) |
5494 | && (*lang_hooks.decls.global_bindings_p) () == 0 | |
9e042f31 | 5495 | && ! contains_placeholder_p (arg0)) |
2bc77e10 | 5496 | { |
5497 | tree arg = save_expr (arg0); | |
5498 | return build (PLUS_EXPR, type, arg, arg); | |
5499 | } | |
5500 | } | |
5501 | goto associate; | |
5502 | ||
5503 | case BIT_IOR_EXPR: | |
5504 | bit_ior: | |
5505 | if (integer_all_onesp (arg1)) | |
5506 | return omit_one_operand (type, arg1, arg0); | |
5507 | if (integer_zerop (arg1)) | |
5508 | return non_lvalue (convert (type, arg0)); | |
5509 | t1 = distribute_bit_expr (code, type, arg0, arg1); | |
5510 | if (t1 != NULL_TREE) | |
5511 | return t1; | |
3bba0206 | 5512 | |
71c3029a | 5513 | /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))). |
5514 | ||
cc049fa3 | 5515 | This results in more efficient code for machines without a NAND |
71c3029a | 5516 | instruction. Combine will canonicalize to the first form |
5517 | which will allow use of NAND instructions provided by the | |
5518 | backend if they exist. */ | |
5519 | if (TREE_CODE (arg0) == BIT_NOT_EXPR | |
5520 | && TREE_CODE (arg1) == BIT_NOT_EXPR) | |
5521 | { | |
5522 | return fold (build1 (BIT_NOT_EXPR, type, | |
5523 | build (BIT_AND_EXPR, type, | |
5524 | TREE_OPERAND (arg0, 0), | |
5525 | TREE_OPERAND (arg1, 0)))); | |
5526 | } | |
5527 | ||
0e1e143e | 5528 | /* See if this can be simplified into a rotate first. If that |
5529 | is unsuccessful continue in the association code. */ | |
5530 | goto bit_rotate; | |
2bc77e10 | 5531 | |
5532 | case BIT_XOR_EXPR: | |
5533 | if (integer_zerop (arg1)) | |
5534 | return non_lvalue (convert (type, arg0)); | |
5535 | if (integer_all_onesp (arg1)) | |
5536 | return fold (build1 (BIT_NOT_EXPR, type, arg0)); | |
0e1e143e | 5537 | |
5538 | /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing | |
5539 | with a constant, and the two constants have no bits in common, | |
5540 | we should treat this as a BIT_IOR_EXPR since this may produce more | |
5541 | simplifications. */ | |
5542 | if (TREE_CODE (arg0) == BIT_AND_EXPR | |
5543 | && TREE_CODE (arg1) == BIT_AND_EXPR | |
5544 | && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST | |
5545 | && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST | |
5546 | && integer_zerop (const_binop (BIT_AND_EXPR, | |
5547 | TREE_OPERAND (arg0, 1), | |
5548 | TREE_OPERAND (arg1, 1), 0))) | |
cc049fa3 | 5549 | { |
5550 | code = BIT_IOR_EXPR; | |
5551 | goto bit_ior; | |
5552 | } | |
0e1e143e | 5553 | |
6d94dc5c | 5554 | /* See if this can be simplified into a rotate first. If that |
0e1e143e | 5555 | is unsuccessful continue in the association code. */ |
6d94dc5c | 5556 | goto bit_rotate; |
2bc77e10 | 5557 | |
5558 | case BIT_AND_EXPR: | |
5559 | bit_and: | |
5560 | if (integer_all_onesp (arg1)) | |
5561 | return non_lvalue (convert (type, arg0)); | |
5562 | if (integer_zerop (arg1)) | |
5563 | return omit_one_operand (type, arg1, arg0); | |
5564 | t1 = distribute_bit_expr (code, type, arg0, arg1); | |
5565 | if (t1 != NULL_TREE) | |
5566 | return t1; | |
5567 | /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */ | |
2bc77e10 | 5568 | if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR |
5569 | && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0)))) | |
5570 | { | |
02e7a332 | 5571 | unsigned int prec |
5572 | = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))); | |
5573 | ||
b572011e | 5574 | if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT |
5575 | && (~TREE_INT_CST_LOW (arg1) | |
5576 | & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0) | |
2bc77e10 | 5577 | return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0)); |
5578 | } | |
71c3029a | 5579 | |
965506c6 | 5580 | /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))). |
71c3029a | 5581 | |
cc049fa3 | 5582 | This results in more efficient code for machines without a NOR |
71c3029a | 5583 | instruction. Combine will canonicalize to the first form |
5584 | which will allow use of NOR instructions provided by the | |
5585 | backend if they exist. */ | |
5586 | if (TREE_CODE (arg0) == BIT_NOT_EXPR | |
5587 | && TREE_CODE (arg1) == BIT_NOT_EXPR) | |
5588 | { | |
5589 | return fold (build1 (BIT_NOT_EXPR, type, | |
5590 | build (BIT_IOR_EXPR, type, | |
5591 | TREE_OPERAND (arg0, 0), | |
5592 | TREE_OPERAND (arg1, 0)))); | |
5593 | } | |
5594 | ||
2bc77e10 | 5595 | goto associate; |
5596 | ||
5597 | case BIT_ANDTC_EXPR: | |
5598 | if (integer_all_onesp (arg0)) | |
5599 | return non_lvalue (convert (type, arg1)); | |
5600 | if (integer_zerop (arg0)) | |
5601 | return omit_one_operand (type, arg0, arg1); | |
5602 | if (TREE_CODE (arg1) == INTEGER_CST) | |
5603 | { | |
5604 | arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1)); | |
5605 | code = BIT_AND_EXPR; | |
5606 | goto bit_and; | |
5607 | } | |
5608 | goto binary; | |
5609 | ||
0f586b9b | 5610 | case RDIV_EXPR: |
badfe841 | 5611 | /* Don't touch a floating-point divide by zero unless the mode |
5612 | of the constant can represent infinity. */ | |
5613 | if (TREE_CODE (arg1) == REAL_CST | |
5614 | && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1))) | |
5615 | && real_zerop (arg1)) | |
0f586b9b | 5616 | return t; |
0f586b9b | 5617 | |
88b41b10 | 5618 | /* (-A) / (-B) -> A / B */ |
5619 | if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR) | |
5620 | return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0), | |
5621 | TREE_OPERAND (arg1, 0))); | |
5622 | ||
0a8176f3 | 5623 | /* In IEEE floating point, x/1 is not equivalent to x for snans. */ |
5624 | if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))) | |
5625 | && real_onep (arg1)) | |
0f586b9b | 5626 | return non_lvalue (convert (type, arg0)); |
5627 | ||
5628 | /* If ARG1 is a constant, we can convert this to a multiply by the | |
5629 | reciprocal. This does not have the same rounding properties, | |
7f3be425 | 5630 | so only do this if -funsafe-math-optimizations. We can actually |
5631 | always safely do it if ARG1 is a power of two, but it's hard to | |
5632 | tell if it is or not in a portable manner. */ | |
88181ec5 | 5633 | if (TREE_CODE (arg1) == REAL_CST) |
5634 | { | |
7f3be425 | 5635 | if (flag_unsafe_math_optimizations |
88181ec5 | 5636 | && 0 != (tem = const_binop (code, build_real (type, dconst1), |
5637 | arg1, 0))) | |
5638 | return fold (build (MULT_EXPR, type, arg0, tem)); | |
6312a35e | 5639 | /* Find the reciprocal if optimizing and the result is exact. */ |
88181ec5 | 5640 | else if (optimize) |
5641 | { | |
5642 | REAL_VALUE_TYPE r; | |
5643 | r = TREE_REAL_CST (arg1); | |
5644 | if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r)) | |
cc049fa3 | 5645 | { |
5646 | tem = build_real (type, r); | |
5647 | return fold (build (MULT_EXPR, type, arg0, tem)); | |
5648 | } | |
88181ec5 | 5649 | } |
5650 | } | |
d82dc0a7 | 5651 | /* Convert A/B/C to A/(B*C). */ |
5652 | if (flag_unsafe_math_optimizations | |
5653 | && TREE_CODE (arg0) == RDIV_EXPR) | |
5654 | { | |
5655 | return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0), | |
5656 | build (MULT_EXPR, type, TREE_OPERAND (arg0, 1), | |
5657 | arg1))); | |
5658 | } | |
5659 | /* Convert A/(B/C) to (A/B)*C. */ | |
5660 | if (flag_unsafe_math_optimizations | |
5661 | && TREE_CODE (arg1) == RDIV_EXPR) | |
5662 | { | |
5663 | return fold (build (MULT_EXPR, type, | |
5664 | build (RDIV_EXPR, type, arg0, | |
5665 | TREE_OPERAND (arg1, 0)), | |
5666 | TREE_OPERAND (arg1, 1))); | |
5667 | } | |
0f586b9b | 5668 | goto binary; |
5669 | ||
2bc77e10 | 5670 | case TRUNC_DIV_EXPR: |
5671 | case ROUND_DIV_EXPR: | |
5672 | case FLOOR_DIV_EXPR: | |
5673 | case CEIL_DIV_EXPR: | |
5674 | case EXACT_DIV_EXPR: | |
2bc77e10 | 5675 | if (integer_onep (arg1)) |
5676 | return non_lvalue (convert (type, arg0)); | |
5677 | if (integer_zerop (arg1)) | |
5678 | return t; | |
39635df9 | 5679 | |
76a0ced5 | 5680 | /* If arg0 is a multiple of arg1, then rewrite to the fastest div |
5681 | operation, EXACT_DIV_EXPR. | |
5682 | ||
a433cd39 | 5683 | Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now. |
5684 | At one time others generated faster code, it's not clear if they do | |
5685 | after the last round to changes to the DIV code in expmed.c. */ | |
5686 | if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR) | |
76a0ced5 | 5687 | && multiple_of_p (type, arg0, arg1)) |
5688 | return fold (build (EXACT_DIV_EXPR, type, arg0, arg1)); | |
5689 | ||
cc049fa3 | 5690 | if (TREE_CODE (arg1) == INTEGER_CST |
23ec2d5e | 5691 | && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1, |
5692 | code, NULL_TREE))) | |
5693 | return convert (type, tem); | |
39635df9 | 5694 | |
2bc77e10 | 5695 | goto binary; |
5696 | ||
5697 | case CEIL_MOD_EXPR: | |
5698 | case FLOOR_MOD_EXPR: | |
5699 | case ROUND_MOD_EXPR: | |
5700 | case TRUNC_MOD_EXPR: | |
5701 | if (integer_onep (arg1)) | |
5702 | return omit_one_operand (type, integer_zero_node, arg0); | |
5703 | if (integer_zerop (arg1)) | |
5704 | return t; | |
e4142c0f | 5705 | |
e4142c0f | 5706 | if (TREE_CODE (arg1) == INTEGER_CST |
23ec2d5e | 5707 | && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1, |
5708 | code, NULL_TREE))) | |
5709 | return convert (type, tem); | |
e4142c0f | 5710 | |
2bc77e10 | 5711 | goto binary; |
5712 | ||
5713 | case LSHIFT_EXPR: | |
5714 | case RSHIFT_EXPR: | |
5715 | case LROTATE_EXPR: | |
5716 | case RROTATE_EXPR: | |
5717 | if (integer_zerop (arg1)) | |
5718 | return non_lvalue (convert (type, arg0)); | |
5719 | /* Since negative shift count is not well-defined, | |
5720 | don't try to compute it in the compiler. */ | |
7a1b56a9 | 5721 | if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0) |
2bc77e10 | 5722 | return t; |
7a1b56a9 | 5723 | /* Rewrite an LROTATE_EXPR by a constant into an |
5724 | RROTATE_EXPR by a new constant. */ | |
5725 | if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST) | |
5726 | { | |
5727 | TREE_SET_CODE (t, RROTATE_EXPR); | |
5728 | code = RROTATE_EXPR; | |
5729 | TREE_OPERAND (t, 1) = arg1 | |
5730 | = const_binop | |
5731 | (MINUS_EXPR, | |
5732 | convert (TREE_TYPE (arg1), | |
5733 | build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)), | |
5734 | arg1, 0); | |
5735 | if (tree_int_cst_sgn (arg1) < 0) | |
5736 | return t; | |
5737 | } | |
5738 | ||
5739 | /* If we have a rotate of a bit operation with the rotate count and | |
5740 | the second operand of the bit operation both constant, | |
5741 | permute the two operations. */ | |
5742 | if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST | |
5743 | && (TREE_CODE (arg0) == BIT_AND_EXPR | |
5744 | || TREE_CODE (arg0) == BIT_ANDTC_EXPR | |
5745 | || TREE_CODE (arg0) == BIT_IOR_EXPR | |
5746 | || TREE_CODE (arg0) == BIT_XOR_EXPR) | |
5747 | && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST) | |
5748 | return fold (build (TREE_CODE (arg0), type, | |
5749 | fold (build (code, type, | |
5750 | TREE_OPERAND (arg0, 0), arg1)), | |
5751 | fold (build (code, type, | |
5752 | TREE_OPERAND (arg0, 1), arg1)))); | |
5753 | ||
5754 | /* Two consecutive rotates adding up to the width of the mode can | |
5755 | be ignored. */ | |
5756 | if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST | |
5757 | && TREE_CODE (arg0) == RROTATE_EXPR | |
5758 | && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST | |
5759 | && TREE_INT_CST_HIGH (arg1) == 0 | |
5760 | && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0 | |
5761 | && ((TREE_INT_CST_LOW (arg1) | |
5762 | + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1))) | |
a0c2c45b | 5763 | == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type)))) |
7a1b56a9 | 5764 | return TREE_OPERAND (arg0, 0); |
5765 | ||
2bc77e10 | 5766 | goto binary; |
5767 | ||
5768 | case MIN_EXPR: | |
5769 | if (operand_equal_p (arg0, arg1, 0)) | |
3a6656ad | 5770 | return omit_one_operand (type, arg0, arg1); |
780a4395 | 5771 | if (INTEGRAL_TYPE_P (type) |
2bc77e10 | 5772 | && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1)) |
5773 | return omit_one_operand (type, arg1, arg0); | |
5774 | goto associate; | |
5775 | ||
5776 | case MAX_EXPR: | |
5777 | if (operand_equal_p (arg0, arg1, 0)) | |
3a6656ad | 5778 | return omit_one_operand (type, arg0, arg1); |
780a4395 | 5779 | if (INTEGRAL_TYPE_P (type) |
f52483b5 | 5780 | && TYPE_MAX_VALUE (type) |
2bc77e10 | 5781 | && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1)) |
5782 | return omit_one_operand (type, arg1, arg0); | |
5783 | goto associate; | |
5784 | ||
5785 | case TRUTH_NOT_EXPR: | |
5786 | /* Note that the operand of this must be an int | |
5787 | and its values must be 0 or 1. | |
5788 | ("true" is a fixed value perhaps depending on the language, | |
5789 | but we don't handle values other than 1 correctly yet.) */ | |
7bbc42b5 | 5790 | tem = invert_truthvalue (arg0); |
5791 | /* Avoid infinite recursion. */ | |
5792 | if (TREE_CODE (tem) == TRUTH_NOT_EXPR) | |
5793 | return t; | |
5794 | return convert (type, tem); | |
2bc77e10 | 5795 | |
5796 | case TRUTH_ANDIF_EXPR: | |
5797 | /* Note that the operands of this must be ints | |
5798 | and their values must be 0 or 1. | |
5799 | ("true" is a fixed value perhaps depending on the language.) */ | |
5800 | /* If first arg is constant zero, return it. */ | |
9a7b73a1 | 5801 | if (integer_zerop (arg0)) |
3a6656ad | 5802 | return convert (type, arg0); |
2bc77e10 | 5803 | case TRUTH_AND_EXPR: |
5804 | /* If either arg is constant true, drop it. */ | |
5805 | if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0)) | |
3a6656ad | 5806 | return non_lvalue (convert (type, arg1)); |
4e91a871 | 5807 | if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1) |
5808 | /* Preserve sequence points. */ | |
5809 | && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0))) | |
3a6656ad | 5810 | return non_lvalue (convert (type, arg0)); |
9a7b73a1 | 5811 | /* If second arg is constant zero, result is zero, but first arg |
5812 | must be evaluated. */ | |
5813 | if (integer_zerop (arg1)) | |
5814 | return omit_one_operand (type, arg1, arg0); | |
f83854c8 | 5815 | /* Likewise for first arg, but note that only the TRUTH_AND_EXPR |
5816 | case will be handled here. */ | |
5817 | if (integer_zerop (arg0)) | |
5818 | return omit_one_operand (type, arg0, arg1); | |
2bc77e10 | 5819 | |
5820 | truth_andor: | |
935abd69 | 5821 | /* We only do these simplifications if we are optimizing. */ |
5822 | if (!optimize) | |
5823 | return t; | |
5824 | ||
5825 | /* Check for things like (A || B) && (A || C). We can convert this | |
5826 | to A || (B && C). Note that either operator can be any of the four | |
5827 | truth and/or operations and the transformation will still be | |
5828 | valid. Also note that we only care about order for the | |
a8149ca2 | 5829 | ANDIF and ORIF operators. If B contains side effects, this |
6312a35e | 5830 | might change the truth-value of A. */ |
935abd69 | 5831 | if (TREE_CODE (arg0) == TREE_CODE (arg1) |
5832 | && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR | |
5833 | || TREE_CODE (arg0) == TRUTH_ORIF_EXPR | |
5834 | || TREE_CODE (arg0) == TRUTH_AND_EXPR | |
a8149ca2 | 5835 | || TREE_CODE (arg0) == TRUTH_OR_EXPR) |
5836 | && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1))) | |
935abd69 | 5837 | { |
5838 | tree a00 = TREE_OPERAND (arg0, 0); | |
5839 | tree a01 = TREE_OPERAND (arg0, 1); | |
5840 | tree a10 = TREE_OPERAND (arg1, 0); | |
5841 | tree a11 = TREE_OPERAND (arg1, 1); | |
5842 | int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR | |
5843 | || TREE_CODE (arg0) == TRUTH_AND_EXPR) | |
5844 | && (code == TRUTH_AND_EXPR | |
5845 | || code == TRUTH_OR_EXPR)); | |
5846 | ||
5847 | if (operand_equal_p (a00, a10, 0)) | |
5848 | return fold (build (TREE_CODE (arg0), type, a00, | |
5849 | fold (build (code, type, a01, a11)))); | |
5850 | else if (commutative && operand_equal_p (a00, a11, 0)) | |
5851 | return fold (build (TREE_CODE (arg0), type, a00, | |
5852 | fold (build (code, type, a01, a10)))); | |
5853 | else if (commutative && operand_equal_p (a01, a10, 0)) | |
5854 | return fold (build (TREE_CODE (arg0), type, a01, | |
5855 | fold (build (code, type, a00, a11)))); | |
5856 | ||
5857 | /* This case if tricky because we must either have commutative | |
5858 | operators or else A10 must not have side-effects. */ | |
5859 | ||
5860 | else if ((commutative || ! TREE_SIDE_EFFECTS (a10)) | |
5861 | && operand_equal_p (a01, a11, 0)) | |
5862 | return fold (build (TREE_CODE (arg0), type, | |
5863 | fold (build (code, type, a00, a10)), | |
5864 | a01)); | |
5865 | } | |
5866 | ||
12ec0a8a | 5867 | /* See if we can build a range comparison. */ |
5868 | if (0 != (tem = fold_range_test (t))) | |
5869 | return tem; | |
5870 | ||
2bc77e10 | 5871 | /* Check for the possibility of merging component references. If our |
5872 | lhs is another similar operation, try to merge its rhs with our | |
5873 | rhs. Then try to merge our lhs and rhs. */ | |
935abd69 | 5874 | if (TREE_CODE (arg0) == code |
5875 | && 0 != (tem = fold_truthop (code, type, | |
5876 | TREE_OPERAND (arg0, 1), arg1))) | |
5877 | return fold (build (code, type, TREE_OPERAND (arg0, 0), tem)); | |
2bc77e10 | 5878 | |
935abd69 | 5879 | if ((tem = fold_truthop (code, type, arg0, arg1)) != 0) |
5880 | return tem; | |
8b94828f | 5881 | |
2bc77e10 | 5882 | return t; |
5883 | ||
5884 | case TRUTH_ORIF_EXPR: | |
5885 | /* Note that the operands of this must be ints | |
5886 | and their values must be 0 or true. | |
5887 | ("true" is a fixed value perhaps depending on the language.) */ | |
5888 | /* If first arg is constant true, return it. */ | |
5889 | if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0)) | |
3a6656ad | 5890 | return convert (type, arg0); |
2bc77e10 | 5891 | case TRUTH_OR_EXPR: |
5892 | /* If either arg is constant zero, drop it. */ | |
5893 | if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0)) | |
3a6656ad | 5894 | return non_lvalue (convert (type, arg1)); |
4e91a871 | 5895 | if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1) |
5896 | /* Preserve sequence points. */ | |
5897 | && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0))) | |
3a6656ad | 5898 | return non_lvalue (convert (type, arg0)); |
9a7b73a1 | 5899 | /* If second arg is constant true, result is true, but we must |
5900 | evaluate first arg. */ | |
5901 | if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)) | |
5902 | return omit_one_operand (type, arg1, arg0); | |
f83854c8 | 5903 | /* Likewise for first arg, but note this only occurs here for |
5904 | TRUTH_OR_EXPR. */ | |
5905 | if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0)) | |
5906 | return omit_one_operand (type, arg0, arg1); | |
2bc77e10 | 5907 | goto truth_andor; |
5908 | ||
9a7b73a1 | 5909 | case TRUTH_XOR_EXPR: |
5910 | /* If either arg is constant zero, drop it. */ | |
5911 | if (integer_zerop (arg0)) | |
3a6656ad | 5912 | return non_lvalue (convert (type, arg1)); |
9a7b73a1 | 5913 | if (integer_zerop (arg1)) |
3a6656ad | 5914 | return non_lvalue (convert (type, arg0)); |
9a7b73a1 | 5915 | /* If either arg is constant true, this is a logical inversion. */ |
5916 | if (integer_onep (arg0)) | |
3a6656ad | 5917 | return non_lvalue (convert (type, invert_truthvalue (arg1))); |
9a7b73a1 | 5918 | if (integer_onep (arg1)) |
3a6656ad | 5919 | return non_lvalue (convert (type, invert_truthvalue (arg0))); |
54e99035 | 5920 | return t; |
9a7b73a1 | 5921 | |
2bc77e10 | 5922 | case EQ_EXPR: |
5923 | case NE_EXPR: | |
5924 | case LT_EXPR: | |
5925 | case GT_EXPR: | |
5926 | case LE_EXPR: | |
5927 | case GE_EXPR: | |
f4185d2b | 5928 | /* If one arg is a real or integer constant, put it last. */ |
5929 | if ((TREE_CODE (arg0) == INTEGER_CST | |
5930 | && TREE_CODE (arg1) != INTEGER_CST) | |
5931 | || (TREE_CODE (arg0) == REAL_CST | |
5932 | && TREE_CODE (arg0) != REAL_CST)) | |
5933 | { | |
5934 | TREE_OPERAND (t, 0) = arg1; | |
5935 | TREE_OPERAND (t, 1) = arg0; | |
5936 | arg0 = TREE_OPERAND (t, 0); | |
5937 | arg1 = TREE_OPERAND (t, 1); | |
5938 | code = swap_tree_comparison (code); | |
5939 | TREE_SET_CODE (t, code); | |
5940 | } | |
5941 | ||
88b41b10 | 5942 | if (FLOAT_TYPE_P (TREE_TYPE (arg0))) |
5943 | { | |
5944 | /* (-a) CMP (-b) -> b CMP a */ | |
5945 | if (TREE_CODE (arg0) == NEGATE_EXPR | |
5946 | && TREE_CODE (arg1) == NEGATE_EXPR) | |
5947 | return fold (build (code, type, TREE_OPERAND (arg1, 0), | |
5948 | TREE_OPERAND (arg0, 0))); | |
5949 | /* (-a) CMP CST -> a swap(CMP) (-CST) */ | |
5950 | if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == REAL_CST) | |
5951 | return | |
5952 | fold (build | |
cc049fa3 | 5953 | (swap_tree_comparison (code), type, |
5954 | TREE_OPERAND (arg0, 0), | |
5955 | build_real (TREE_TYPE (arg1), | |
5956 | REAL_VALUE_NEGATE (TREE_REAL_CST (arg1))))); | |
88b41b10 | 5957 | /* IEEE doesn't distinguish +0 and -0 in comparisons. */ |
5958 | /* a CMP (-0) -> a CMP 0 */ | |
6f96ce2b | 5959 | if (TREE_CODE (arg1) == REAL_CST |
5960 | && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1))) | |
88b41b10 | 5961 | return fold (build (code, type, arg0, |
5962 | build_real (TREE_TYPE (arg1), dconst0))); | |
88b41b10 | 5963 | |
f4185d2b | 5964 | /* If this is a comparison of a real constant with a PLUS_EXPR |
5965 | or a MINUS_EXPR of a real constant, we can convert it into a | |
5966 | comparison with a revised real constant as long as no overflow | |
5967 | occurs when unsafe_math_optimizations are enabled. */ | |
5968 | if (flag_unsafe_math_optimizations | |
5969 | && TREE_CODE (arg1) == REAL_CST | |
5970 | && (TREE_CODE (arg0) == PLUS_EXPR | |
5971 | || TREE_CODE (arg0) == MINUS_EXPR) | |
5972 | && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST | |
5973 | && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR | |
5974 | ? MINUS_EXPR : PLUS_EXPR, | |
5975 | arg1, TREE_OPERAND (arg0, 1), 0)) | |
5976 | && ! TREE_CONSTANT_OVERFLOW (tem)) | |
5977 | return fold (build (code, type, TREE_OPERAND (arg0, 0), tem)); | |
2bc77e10 | 5978 | } |
5979 | ||
5980 | /* Convert foo++ == CONST into ++foo == CONST + INCR. | |
5981 | First, see if one arg is constant; find the constant arg | |
5982 | and the other one. */ | |
5983 | { | |
93b6a460 | 5984 | tree constop = 0, varop = NULL_TREE; |
f13f9c7f | 5985 | int constopnum = -1; |
2bc77e10 | 5986 | |
5987 | if (TREE_CONSTANT (arg1)) | |
f13f9c7f | 5988 | constopnum = 1, constop = arg1, varop = arg0; |
2bc77e10 | 5989 | if (TREE_CONSTANT (arg0)) |
f13f9c7f | 5990 | constopnum = 0, constop = arg0, varop = arg1; |
2bc77e10 | 5991 | |
5992 | if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR) | |
5993 | { | |
2bc77e10 | 5994 | /* This optimization is invalid for ordered comparisons |
5995 | if CONST+INCR overflows or if foo+incr might overflow. | |
e233264a | 5996 | This optimization is invalid for floating point due to rounding. |
2bc77e10 | 5997 | For pointer types we assume overflow doesn't happen. */ |
997d68fe | 5998 | if (POINTER_TYPE_P (TREE_TYPE (varop)) |
780a4395 | 5999 | || (! FLOAT_TYPE_P (TREE_TYPE (varop)) |
e233264a | 6000 | && (code == EQ_EXPR || code == NE_EXPR))) |
2bc77e10 | 6001 | { |
e233264a | 6002 | tree newconst |
6003 | = fold (build (PLUS_EXPR, TREE_TYPE (varop), | |
6004 | constop, TREE_OPERAND (varop, 1))); | |
e8d76c53 | 6005 | |
6006 | /* Do not overwrite the current varop to be a preincrement, | |
6007 | create a new node so that we won't confuse our caller who | |
6008 | might create trees and throw them away, reusing the | |
6009 | arguments that they passed to build. This shows up in | |
6010 | the THEN or ELSE parts of ?: being postincrements. */ | |
6011 | varop = build (PREINCREMENT_EXPR, TREE_TYPE (varop), | |
6012 | TREE_OPERAND (varop, 0), | |
6013 | TREE_OPERAND (varop, 1)); | |
f13f9c7f | 6014 | |
9d5c6945 | 6015 | /* If VAROP is a reference to a bitfield, we must mask |
6016 | the constant by the width of the field. */ | |
6017 | if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF | |
6018 | && DECL_BIT_FIELD(TREE_OPERAND | |
6019 | (TREE_OPERAND (varop, 0), 1))) | |
6020 | { | |
6021 | int size | |
6022 | = TREE_INT_CST_LOW (DECL_SIZE | |
6023 | (TREE_OPERAND | |
6024 | (TREE_OPERAND (varop, 0), 1))); | |
a67ad12d | 6025 | tree mask, unsigned_type; |
02e7a332 | 6026 | unsigned int precision; |
a67ad12d | 6027 | tree folded_compare; |
6028 | ||
6029 | /* First check whether the comparison would come out | |
6030 | always the same. If we don't do that we would | |
6031 | change the meaning with the masking. */ | |
6032 | if (constopnum == 0) | |
6033 | folded_compare = fold (build (code, type, constop, | |
6034 | TREE_OPERAND (varop, 0))); | |
6035 | else | |
6036 | folded_compare = fold (build (code, type, | |
6037 | TREE_OPERAND (varop, 0), | |
6038 | constop)); | |
6039 | if (integer_zerop (folded_compare) | |
6040 | || integer_onep (folded_compare)) | |
6041 | return omit_one_operand (type, folded_compare, varop); | |
6042 | ||
771d21fa | 6043 | unsigned_type = (*lang_hooks.types.type_for_size)(size, 1); |
a67ad12d | 6044 | precision = TYPE_PRECISION (unsigned_type); |
6045 | mask = build_int_2 (~0, ~0); | |
6046 | TREE_TYPE (mask) = unsigned_type; | |
6047 | force_fit_type (mask, 0); | |
6048 | mask = const_binop (RSHIFT_EXPR, mask, | |
6049 | size_int (precision - size), 0); | |
9d5c6945 | 6050 | newconst = fold (build (BIT_AND_EXPR, |
6051 | TREE_TYPE (varop), newconst, | |
6052 | convert (TREE_TYPE (varop), | |
a67ad12d | 6053 | mask))); |
9d5c6945 | 6054 | } |
9d5c6945 | 6055 | |
e8d76c53 | 6056 | t = build (code, type, |
6057 | (constopnum == 0) ? newconst : varop, | |
6058 | (constopnum == 1) ? newconst : varop); | |
e233264a | 6059 | return t; |
2bc77e10 | 6060 | } |
6061 | } | |
6062 | else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR) | |
6063 | { | |
997d68fe | 6064 | if (POINTER_TYPE_P (TREE_TYPE (varop)) |
780a4395 | 6065 | || (! FLOAT_TYPE_P (TREE_TYPE (varop)) |
e233264a | 6066 | && (code == EQ_EXPR || code == NE_EXPR))) |
2bc77e10 | 6067 | { |
e233264a | 6068 | tree newconst |
6069 | = fold (build (MINUS_EXPR, TREE_TYPE (varop), | |
6070 | constop, TREE_OPERAND (varop, 1))); | |
e8d76c53 | 6071 | |
6072 | /* Do not overwrite the current varop to be a predecrement, | |
6073 | create a new node so that we won't confuse our caller who | |
6074 | might create trees and throw them away, reusing the | |
6075 | arguments that they passed to build. This shows up in | |
6076 | the THEN or ELSE parts of ?: being postdecrements. */ | |
6077 | varop = build (PREDECREMENT_EXPR, TREE_TYPE (varop), | |
6078 | TREE_OPERAND (varop, 0), | |
6079 | TREE_OPERAND (varop, 1)); | |
9d5c6945 | 6080 | |
6081 | if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF | |
6082 | && DECL_BIT_FIELD(TREE_OPERAND | |
6083 | (TREE_OPERAND (varop, 0), 1))) | |
6084 | { | |
6085 | int size | |
6086 | = TREE_INT_CST_LOW (DECL_SIZE | |
6087 | (TREE_OPERAND | |
6088 | (TREE_OPERAND (varop, 0), 1))); | |
a67ad12d | 6089 | tree mask, unsigned_type; |
02e7a332 | 6090 | unsigned int precision; |
a67ad12d | 6091 | tree folded_compare; |
6092 | ||
6093 | if (constopnum == 0) | |
6094 | folded_compare = fold (build (code, type, constop, | |
6095 | TREE_OPERAND (varop, 0))); | |
6096 | else | |
6097 | folded_compare = fold (build (code, type, | |
6098 | TREE_OPERAND (varop, 0), | |
6099 | constop)); | |
6100 | if (integer_zerop (folded_compare) | |
6101 | || integer_onep (folded_compare)) | |
6102 | return omit_one_operand (type, folded_compare, varop); | |
6103 | ||
771d21fa | 6104 | unsigned_type = (*lang_hooks.types.type_for_size)(size, 1); |
a67ad12d | 6105 | precision = TYPE_PRECISION (unsigned_type); |
6106 | mask = build_int_2 (~0, ~0); | |
6107 | TREE_TYPE (mask) = TREE_TYPE (varop); | |
6108 | force_fit_type (mask, 0); | |
6109 | mask = const_binop (RSHIFT_EXPR, mask, | |
6110 | size_int (precision - size), 0); | |
9d5c6945 | 6111 | newconst = fold (build (BIT_AND_EXPR, |
6112 | TREE_TYPE (varop), newconst, | |
6113 | convert (TREE_TYPE (varop), | |
a67ad12d | 6114 | mask))); |
9d5c6945 | 6115 | } |
9d5c6945 | 6116 | |
e8d76c53 | 6117 | t = build (code, type, |
6118 | (constopnum == 0) ? newconst : varop, | |
6119 | (constopnum == 1) ? newconst : varop); | |
e233264a | 6120 | return t; |
2bc77e10 | 6121 | } |
6122 | } | |
6123 | } | |
6124 | ||
7df2ee7b | 6125 | /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0. |
6126 | This transformation affects the cases which are handled in later | |
6127 | optimizations involving comparisons with non-negative constants. */ | |
6128 | if (TREE_CODE (arg1) == INTEGER_CST | |
6129 | && TREE_CODE (arg0) != INTEGER_CST | |
6130 | && tree_int_cst_sgn (arg1) > 0) | |
6131 | { | |
6132 | switch (code) | |
6133 | { | |
6134 | case GE_EXPR: | |
6135 | code = GT_EXPR; | |
6136 | arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0); | |
6137 | t = build (code, type, TREE_OPERAND (t, 0), arg1); | |
6138 | break; | |
6139 | ||
6140 | case LT_EXPR: | |
6141 | code = LE_EXPR; | |
6142 | arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0); | |
6143 | t = build (code, type, TREE_OPERAND (t, 0), arg1); | |
6144 | break; | |
6145 | ||
6146 | default: | |
6147 | break; | |
6148 | } | |
6149 | } | |
6150 | ||
8539da5e | 6151 | /* Comparisons with the highest or lowest possible integer of |
7df2ee7b | 6152 | the specified size will have known values. */ |
8539da5e | 6153 | { |
6154 | int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1))); | |
6155 | ||
6156 | if (TREE_CODE (arg1) == INTEGER_CST | |
6157 | && ! TREE_CONSTANT_OVERFLOW (arg1) | |
6158 | && width <= HOST_BITS_PER_WIDE_INT | |
6159 | && (INTEGRAL_TYPE_P (TREE_TYPE (arg1)) | |
6160 | || POINTER_TYPE_P (TREE_TYPE (arg1)))) | |
6161 | { | |
7df2ee7b | 6162 | unsigned HOST_WIDE_INT signed_max; |
6163 | unsigned HOST_WIDE_INT max, min; | |
6164 | ||
6165 | signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1; | |
6166 | ||
6167 | if (TREE_UNSIGNED (TREE_TYPE (arg1))) | |
6168 | { | |
6169 | max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1; | |
6170 | min = 0; | |
6171 | } | |
6172 | else | |
6173 | { | |
6174 | max = signed_max; | |
6175 | min = ((unsigned HOST_WIDE_INT) -1 << (width - 1)); | |
6176 | } | |
6177 | ||
8539da5e | 6178 | if (TREE_INT_CST_HIGH (arg1) == 0 |
7df2ee7b | 6179 | && TREE_INT_CST_LOW (arg1) == max) |
6180 | switch (code) | |
8539da5e | 6181 | { |
6182 | case GT_EXPR: | |
6183 | return omit_one_operand (type, | |
6184 | convert (type, integer_zero_node), | |
6185 | arg0); | |
6186 | case GE_EXPR: | |
7df2ee7b | 6187 | code = EQ_EXPR; |
8539da5e | 6188 | TREE_SET_CODE (t, EQ_EXPR); |
6189 | break; | |
8539da5e | 6190 | case LE_EXPR: |
6191 | return omit_one_operand (type, | |
6192 | convert (type, integer_one_node), | |
6193 | arg0); | |
6194 | case LT_EXPR: | |
7df2ee7b | 6195 | code = NE_EXPR; |
8539da5e | 6196 | TREE_SET_CODE (t, NE_EXPR); |
6197 | break; | |
6198 | ||
7df2ee7b | 6199 | /* The GE_EXPR and LT_EXPR cases above are not normally |
6200 | reached because of previous transformations. */ | |
6201 | ||
8539da5e | 6202 | default: |
6203 | break; | |
6204 | } | |
7df2ee7b | 6205 | else if (TREE_INT_CST_HIGH (arg1) == 0 |
6206 | && TREE_INT_CST_LOW (arg1) == max - 1) | |
6207 | switch (code) | |
6208 | { | |
6209 | case GT_EXPR: | |
6210 | code = EQ_EXPR; | |
6211 | arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0); | |
6212 | t = build (code, type, TREE_OPERAND (t, 0), arg1); | |
6213 | break; | |
6214 | case LE_EXPR: | |
6215 | code = NE_EXPR; | |
6216 | arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0); | |
6217 | t = build (code, type, TREE_OPERAND (t, 0), arg1); | |
6218 | break; | |
6219 | default: | |
6220 | break; | |
6221 | } | |
6222 | else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0) | |
6223 | && TREE_INT_CST_LOW (arg1) == min) | |
6224 | switch (code) | |
8539da5e | 6225 | { |
6226 | case LT_EXPR: | |
6227 | return omit_one_operand (type, | |
6228 | convert (type, integer_zero_node), | |
6229 | arg0); | |
6230 | case LE_EXPR: | |
7df2ee7b | 6231 | code = EQ_EXPR; |
8539da5e | 6232 | TREE_SET_CODE (t, EQ_EXPR); |
6233 | break; | |
6234 | ||
6235 | case GE_EXPR: | |
6236 | return omit_one_operand (type, | |
6237 | convert (type, integer_one_node), | |
6238 | arg0); | |
6239 | case GT_EXPR: | |
7df2ee7b | 6240 | code = NE_EXPR; |
8539da5e | 6241 | TREE_SET_CODE (t, NE_EXPR); |
6242 | break; | |
6243 | ||
6244 | default: | |
6245 | break; | |
6246 | } | |
7df2ee7b | 6247 | else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0) |
6248 | && TREE_INT_CST_LOW (arg1) == min + 1) | |
6249 | switch (code) | |
6250 | { | |
6251 | case GE_EXPR: | |
6252 | code = NE_EXPR; | |
6253 | arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0); | |
6254 | t = build (code, type, TREE_OPERAND (t, 0), arg1); | |
6255 | break; | |
6256 | case LT_EXPR: | |
6257 | code = EQ_EXPR; | |
6258 | arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0); | |
6259 | t = build (code, type, TREE_OPERAND (t, 0), arg1); | |
6260 | break; | |
6261 | default: | |
6262 | break; | |
6263 | } | |
8539da5e | 6264 | |
6265 | else if (TREE_INT_CST_HIGH (arg1) == 0 | |
7df2ee7b | 6266 | && TREE_INT_CST_LOW (arg1) == signed_max |
8539da5e | 6267 | && TREE_UNSIGNED (TREE_TYPE (arg1)) |
6268 | /* signed_type does not work on pointer types. */ | |
6269 | && INTEGRAL_TYPE_P (TREE_TYPE (arg1))) | |
6270 | { | |
7df2ee7b | 6271 | /* The following case also applies to X < signed_max+1 |
6272 | and X >= signed_max+1 because previous transformations. */ | |
6273 | if (code == LE_EXPR || code == GT_EXPR) | |
8539da5e | 6274 | { |
6275 | tree st0, st1; | |
6276 | st0 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg0)); | |
6277 | st1 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg1)); | |
6278 | return fold | |
7df2ee7b | 6279 | (build (code == LE_EXPR ? GE_EXPR: LT_EXPR, |
8539da5e | 6280 | type, convert (st0, arg0), |
6281 | convert (st1, integer_zero_node))); | |
6282 | } | |
6283 | } | |
8539da5e | 6284 | } |
6285 | } | |
6286 | ||
155b05dc | 6287 | /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or |
6288 | a MINUS_EXPR of a constant, we can convert it into a comparison with | |
6289 | a revised constant as long as no overflow occurs. */ | |
6290 | if ((code == EQ_EXPR || code == NE_EXPR) | |
6291 | && TREE_CODE (arg1) == INTEGER_CST | |
6292 | && (TREE_CODE (arg0) == PLUS_EXPR | |
6293 | || TREE_CODE (arg0) == MINUS_EXPR) | |
6294 | && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST | |
6295 | && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR | |
6296 | ? MINUS_EXPR : PLUS_EXPR, | |
6297 | arg1, TREE_OPERAND (arg0, 1), 0)) | |
6298 | && ! TREE_CONSTANT_OVERFLOW (tem)) | |
6299 | return fold (build (code, type, TREE_OPERAND (arg0, 0), tem)); | |
6300 | ||
6301 | /* Similarly for a NEGATE_EXPR. */ | |
6302 | else if ((code == EQ_EXPR || code == NE_EXPR) | |
6303 | && TREE_CODE (arg0) == NEGATE_EXPR | |
6304 | && TREE_CODE (arg1) == INTEGER_CST | |
23ec2d5e | 6305 | && 0 != (tem = negate_expr (arg1)) |
155b05dc | 6306 | && TREE_CODE (tem) == INTEGER_CST |
6307 | && ! TREE_CONSTANT_OVERFLOW (tem)) | |
6308 | return fold (build (code, type, TREE_OPERAND (arg0, 0), tem)); | |
6309 | ||
6310 | /* If we have X - Y == 0, we can convert that to X == Y and similarly | |
6311 | for !=. Don't do this for ordered comparisons due to overflow. */ | |
6312 | else if ((code == NE_EXPR || code == EQ_EXPR) | |
6313 | && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR) | |
6314 | return fold (build (code, type, | |
6315 | TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1))); | |
6316 | ||
6317 | /* If we are widening one operand of an integer comparison, | |
6318 | see if the other operand is similarly being widened. Perhaps we | |
6319 | can do the comparison in the narrower type. */ | |
6320 | else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE | |
6321 | && TREE_CODE (arg0) == NOP_EXPR | |
6322 | && (tem = get_unwidened (arg0, NULL_TREE)) != arg0 | |
6323 | && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0 | |
6324 | && (TREE_TYPE (t1) == TREE_TYPE (tem) | |
6325 | || (TREE_CODE (t1) == INTEGER_CST | |
6326 | && int_fits_type_p (t1, TREE_TYPE (tem))))) | |
6327 | return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1))); | |
cc049fa3 | 6328 | |
155b05dc | 6329 | /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a |
6330 | constant, we can simplify it. */ | |
6331 | else if (TREE_CODE (arg1) == INTEGER_CST | |
6332 | && (TREE_CODE (arg0) == MIN_EXPR | |
6333 | || TREE_CODE (arg0) == MAX_EXPR) | |
6334 | && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST) | |
6335 | return optimize_minmax_comparison (t); | |
6336 | ||
6337 | /* If we are comparing an ABS_EXPR with a constant, we can | |
6338 | convert all the cases into explicit comparisons, but they may | |
6339 | well not be faster than doing the ABS and one comparison. | |
6340 | But ABS (X) <= C is a range comparison, which becomes a subtraction | |
6341 | and a comparison, and is probably faster. */ | |
6342 | else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST | |
6343 | && TREE_CODE (arg0) == ABS_EXPR | |
23ec2d5e | 6344 | && ! TREE_SIDE_EFFECTS (arg0) |
6345 | && (0 != (tem = negate_expr (arg1))) | |
6346 | && TREE_CODE (tem) == INTEGER_CST | |
6347 | && ! TREE_CONSTANT_OVERFLOW (tem)) | |
6348 | return fold (build (TRUTH_ANDIF_EXPR, type, | |
6349 | build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem), | |
6350 | build (LE_EXPR, type, | |
6351 | TREE_OPERAND (arg0, 0), arg1))); | |
cc049fa3 | 6352 | |
2bc77e10 | 6353 | /* If this is an EQ or NE comparison with zero and ARG0 is |
6354 | (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require | |
6355 | two operations, but the latter can be done in one less insn | |
0dbd1c74 | 6356 | on machines that have only two-operand insns or on which a |
2bc77e10 | 6357 | constant cannot be the first operand. */ |
6358 | if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR) | |
6359 | && TREE_CODE (arg0) == BIT_AND_EXPR) | |
6360 | { | |
6361 | if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR | |
6362 | && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0))) | |
6363 | return | |
6364 | fold (build (code, type, | |
6365 | build (BIT_AND_EXPR, TREE_TYPE (arg0), | |
6366 | build (RSHIFT_EXPR, | |
6367 | TREE_TYPE (TREE_OPERAND (arg0, 0)), | |
6368 | TREE_OPERAND (arg0, 1), | |
6369 | TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)), | |
6370 | convert (TREE_TYPE (arg0), | |
6371 | integer_one_node)), | |
6372 | arg1)); | |
6373 | else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR | |
6374 | && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0))) | |
6375 | return | |
6376 | fold (build (code, type, | |
6377 | build (BIT_AND_EXPR, TREE_TYPE (arg0), | |
6378 | build (RSHIFT_EXPR, | |
6379 | TREE_TYPE (TREE_OPERAND (arg0, 1)), | |
6380 | TREE_OPERAND (arg0, 0), | |
6381 | TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)), | |
6382 | convert (TREE_TYPE (arg0), | |
6383 | integer_one_node)), | |
6384 | arg1)); | |
6385 | } | |
6386 | ||
c393c7ff | 6387 | /* If this is an NE or EQ comparison of zero against the result of a |
722b90ac | 6388 | signed MOD operation whose second operand is a power of 2, make |
6389 | the MOD operation unsigned since it is simpler and equivalent. */ | |
c393c7ff | 6390 | if ((code == NE_EXPR || code == EQ_EXPR) |
6391 | && integer_zerop (arg1) | |
6392 | && ! TREE_UNSIGNED (TREE_TYPE (arg0)) | |
6393 | && (TREE_CODE (arg0) == TRUNC_MOD_EXPR | |
6394 | || TREE_CODE (arg0) == CEIL_MOD_EXPR | |
6395 | || TREE_CODE (arg0) == FLOOR_MOD_EXPR | |
722b90ac | 6396 | || TREE_CODE (arg0) == ROUND_MOD_EXPR) |
6397 | && integer_pow2p (TREE_OPERAND (arg0, 1))) | |
c393c7ff | 6398 | { |
4070745f | 6399 | tree newtype = (*lang_hooks.types.unsigned_type) (TREE_TYPE (arg0)); |
c393c7ff | 6400 | tree newmod = build (TREE_CODE (arg0), newtype, |
6401 | convert (newtype, TREE_OPERAND (arg0, 0)), | |
6402 | convert (newtype, TREE_OPERAND (arg0, 1))); | |
6403 | ||
6404 | return build (code, type, newmod, convert (newtype, arg1)); | |
6405 | } | |
6406 | ||
2bc77e10 | 6407 | /* If this is an NE comparison of zero with an AND of one, remove the |
6408 | comparison since the AND will give the correct value. */ | |
6409 | if (code == NE_EXPR && integer_zerop (arg1) | |
6410 | && TREE_CODE (arg0) == BIT_AND_EXPR | |
6411 | && integer_onep (TREE_OPERAND (arg0, 1))) | |
6412 | return convert (type, arg0); | |
6413 | ||
6414 | /* If we have (A & C) == C where C is a power of 2, convert this into | |
6415 | (A & C) != 0. Similarly for NE_EXPR. */ | |
6416 | if ((code == EQ_EXPR || code == NE_EXPR) | |
6417 | && TREE_CODE (arg0) == BIT_AND_EXPR | |
6418 | && integer_pow2p (TREE_OPERAND (arg0, 1)) | |
6419 | && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0)) | |
203a24c4 | 6420 | return fold (build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type, |
6421 | arg0, integer_zero_node)); | |
6422 | ||
6423 | /* If we have (A & C) != 0 where C is the sign bit of A, convert | |
6424 | this into A < 0. Similarly for (A & C) == 0 into A >= 0. */ | |
6425 | if ((code == EQ_EXPR || code == NE_EXPR) | |
6426 | && TREE_CODE (arg0) == BIT_AND_EXPR | |
6427 | && integer_zerop (arg1)) | |
6428 | { | |
6429 | tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), | |
6430 | TREE_OPERAND (arg0, 1)); | |
6431 | if (arg00 != NULL_TREE) | |
6432 | { | |
6433 | tree stype = (*lang_hooks.types.signed_type) (TREE_TYPE (arg00)); | |
6434 | return fold (build (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type, | |
6435 | convert (stype, arg00), | |
6436 | convert (stype, integer_zero_node))); | |
6437 | } | |
6438 | } | |
2bc77e10 | 6439 | |
898bfb9d | 6440 | /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0 |
e8526af9 | 6441 | and similarly for >= into !=. */ |
898bfb9d | 6442 | if ((code == LT_EXPR || code == GE_EXPR) |
6443 | && TREE_UNSIGNED (TREE_TYPE (arg0)) | |
6444 | && TREE_CODE (arg1) == LSHIFT_EXPR | |
6445 | && integer_onep (TREE_OPERAND (arg1, 0))) | |
cc049fa3 | 6446 | return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type, |
898bfb9d | 6447 | build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0, |
6448 | TREE_OPERAND (arg1, 1)), | |
6449 | convert (TREE_TYPE (arg0), integer_zero_node)); | |
6450 | ||
6451 | else if ((code == LT_EXPR || code == GE_EXPR) | |
6452 | && TREE_UNSIGNED (TREE_TYPE (arg0)) | |
6453 | && (TREE_CODE (arg1) == NOP_EXPR | |
6454 | || TREE_CODE (arg1) == CONVERT_EXPR) | |
6455 | && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR | |
6456 | && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0))) | |
6457 | return | |
6458 | build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type, | |
6459 | convert (TREE_TYPE (arg0), | |
6460 | build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0, | |
6461 | TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))), | |
6462 | convert (TREE_TYPE (arg0), integer_zero_node)); | |
6463 | ||
e233264a | 6464 | /* Simplify comparison of something with itself. (For IEEE |
6465 | floating-point, we can only do some of these simplifications.) */ | |
6466 | if (operand_equal_p (arg0, arg1, 0)) | |
2bc77e10 | 6467 | { |
6468 | switch (code) | |
6469 | { | |
6470 | case EQ_EXPR: | |
6471 | case GE_EXPR: | |
6472 | case LE_EXPR: | |
06deaf7e | 6473 | if (! FLOAT_TYPE_P (TREE_TYPE (arg0))) |
b4af30fd | 6474 | return constant_boolean_node (1, type); |
e233264a | 6475 | code = EQ_EXPR; |
6476 | TREE_SET_CODE (t, code); | |
6477 | break; | |
6478 | ||
2bc77e10 | 6479 | case NE_EXPR: |
e233264a | 6480 | /* For NE, we can only do this simplification if integer. */ |
06deaf7e | 6481 | if (FLOAT_TYPE_P (TREE_TYPE (arg0))) |
e233264a | 6482 | break; |
a92771b8 | 6483 | /* ... fall through ... */ |
2bc77e10 | 6484 | case GT_EXPR: |
6485 | case LT_EXPR: | |
b4af30fd | 6486 | return constant_boolean_node (0, type); |
0dbd1c74 | 6487 | default: |
6488 | abort (); | |
2bc77e10 | 6489 | } |
6490 | } | |
6491 | ||
e233264a | 6492 | /* If we are comparing an expression that just has comparisons |
6493 | of two integer values, arithmetic expressions of those comparisons, | |
6494 | and constants, we can simplify it. There are only three cases | |
6495 | to check: the two values can either be equal, the first can be | |
6496 | greater, or the second can be greater. Fold the expression for | |
6497 | those three values. Since each value must be 0 or 1, we have | |
6498 | eight possibilities, each of which corresponds to the constant 0 | |
6499 | or 1 or one of the six possible comparisons. | |
6500 | ||
6501 | This handles common cases like (a > b) == 0 but also handles | |
6502 | expressions like ((x > y) - (y > x)) > 0, which supposedly | |
6503 | occur in macroized code. */ | |
6504 | ||
6505 | if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST) | |
6506 | { | |
6507 | tree cval1 = 0, cval2 = 0; | |
d0314131 | 6508 | int save_p = 0; |
e233264a | 6509 | |
d0314131 | 6510 | if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p) |
e233264a | 6511 | /* Don't handle degenerate cases here; they should already |
6512 | have been handled anyway. */ | |
6513 | && cval1 != 0 && cval2 != 0 | |
6514 | && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2)) | |
6515 | && TREE_TYPE (cval1) == TREE_TYPE (cval2) | |
780a4395 | 6516 | && INTEGRAL_TYPE_P (TREE_TYPE (cval1)) |
f52483b5 | 6517 | && TYPE_MAX_VALUE (TREE_TYPE (cval1)) |
6518 | && TYPE_MAX_VALUE (TREE_TYPE (cval2)) | |
e233264a | 6519 | && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)), |
6520 | TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0)) | |
6521 | { | |
6522 | tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1)); | |
6523 | tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1)); | |
6524 | ||
6525 | /* We can't just pass T to eval_subst in case cval1 or cval2 | |
6526 | was the same as ARG1. */ | |
6527 | ||
6528 | tree high_result | |
6529 | = fold (build (code, type, | |
6530 | eval_subst (arg0, cval1, maxval, cval2, minval), | |
6531 | arg1)); | |
6532 | tree equal_result | |
6533 | = fold (build (code, type, | |
6534 | eval_subst (arg0, cval1, maxval, cval2, maxval), | |
6535 | arg1)); | |
6536 | tree low_result | |
6537 | = fold (build (code, type, | |
6538 | eval_subst (arg0, cval1, minval, cval2, maxval), | |
6539 | arg1)); | |
6540 | ||
6541 | /* All three of these results should be 0 or 1. Confirm they | |
6542 | are. Then use those values to select the proper code | |
6543 | to use. */ | |
6544 | ||
6545 | if ((integer_zerop (high_result) | |
6546 | || integer_onep (high_result)) | |
6547 | && (integer_zerop (equal_result) | |
6548 | || integer_onep (equal_result)) | |
6549 | && (integer_zerop (low_result) | |
6550 | || integer_onep (low_result))) | |
6551 | { | |
6552 | /* Make a 3-bit mask with the high-order bit being the | |
6553 | value for `>', the next for '=', and the low for '<'. */ | |
6554 | switch ((integer_onep (high_result) * 4) | |
6555 | + (integer_onep (equal_result) * 2) | |
6556 | + integer_onep (low_result)) | |
6557 | { | |
6558 | case 0: | |
6559 | /* Always false. */ | |
88d56342 | 6560 | return omit_one_operand (type, integer_zero_node, arg0); |
e233264a | 6561 | case 1: |
6562 | code = LT_EXPR; | |
6563 | break; | |
6564 | case 2: | |
6565 | code = EQ_EXPR; | |
6566 | break; | |
6567 | case 3: | |
6568 | code = LE_EXPR; | |
6569 | break; | |
6570 | case 4: | |
6571 | code = GT_EXPR; | |
6572 | break; | |
6573 | case 5: | |
6574 | code = NE_EXPR; | |
6575 | break; | |
6576 | case 6: | |
6577 | code = GE_EXPR; | |
6578 | break; | |
6579 | case 7: | |
6580 | /* Always true. */ | |
88d56342 | 6581 | return omit_one_operand (type, integer_one_node, arg0); |
e233264a | 6582 | } |
6583 | ||
d0314131 | 6584 | t = build (code, type, cval1, cval2); |
6585 | if (save_p) | |
6586 | return save_expr (t); | |
6587 | else | |
6588 | return fold (t); | |
e233264a | 6589 | } |
6590 | } | |
6591 | } | |
6592 | ||
6593 | /* If this is a comparison of a field, we may be able to simplify it. */ | |
d50b22af | 6594 | if (((TREE_CODE (arg0) == COMPONENT_REF |
6595 | && (*lang_hooks.can_use_bit_fields_p) ()) | |
6bc517c5 | 6596 | || TREE_CODE (arg0) == BIT_FIELD_REF) |
6597 | && (code == EQ_EXPR || code == NE_EXPR) | |
6598 | /* Handle the constant case even without -O | |
6599 | to make sure the warnings are given. */ | |
6600 | && (optimize || TREE_CODE (arg1) == INTEGER_CST)) | |
6601 | { | |
6602 | t1 = optimize_bit_field_compare (code, type, arg0, arg1); | |
6603 | return t1 ? t1 : t; | |
6604 | } | |
e233264a | 6605 | |
9e042f31 | 6606 | /* If this is a comparison of complex values and either or both sides |
6607 | are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the | |
6608 | comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR. | |
6609 | This may prevent needless evaluations. */ | |
a77cc7ac | 6610 | if ((code == EQ_EXPR || code == NE_EXPR) |
6611 | && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE | |
6612 | && (TREE_CODE (arg0) == COMPLEX_EXPR | |
9e042f31 | 6613 | || TREE_CODE (arg1) == COMPLEX_EXPR |
6614 | || TREE_CODE (arg0) == COMPLEX_CST | |
6615 | || TREE_CODE (arg1) == COMPLEX_CST)) | |
a77cc7ac | 6616 | { |
6617 | tree subtype = TREE_TYPE (TREE_TYPE (arg0)); | |
a0748b7d | 6618 | tree real0, imag0, real1, imag1; |
6619 | ||
6620 | arg0 = save_expr (arg0); | |
6621 | arg1 = save_expr (arg1); | |
6622 | real0 = fold (build1 (REALPART_EXPR, subtype, arg0)); | |
6623 | imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0)); | |
6624 | real1 = fold (build1 (REALPART_EXPR, subtype, arg1)); | |
6625 | imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1)); | |
a77cc7ac | 6626 | |
6627 | return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR | |
6628 | : TRUTH_ORIF_EXPR), | |
6629 | type, | |
6630 | fold (build (code, type, real0, real1)), | |
6631 | fold (build (code, type, imag0, imag1)))); | |
6632 | } | |
6633 | ||
53e0ea7e | 6634 | /* Optimize comparisons of strlen vs zero to a compare of the |
d3371fcd | 6635 | first character of the string vs zero. To wit, |
53e0ea7e | 6636 | strlen(ptr) == 0 => *ptr == 0 |
6637 | strlen(ptr) != 0 => *ptr != 0 | |
6638 | Other cases should reduce to one of these two (or a constant) | |
6639 | due to the return value of strlen being unsigned. */ | |
6640 | if ((code == EQ_EXPR || code == NE_EXPR) | |
6641 | && integer_zerop (arg1) | |
6642 | && TREE_CODE (arg0) == CALL_EXPR | |
6643 | && TREE_CODE (TREE_OPERAND (arg0, 0)) == ADDR_EXPR) | |
6644 | { | |
6645 | tree fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0); | |
6646 | tree arglist; | |
6647 | ||
6648 | if (TREE_CODE (fndecl) == FUNCTION_DECL | |
6649 | && DECL_BUILT_IN (fndecl) | |
6650 | && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD | |
6651 | && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN | |
6652 | && (arglist = TREE_OPERAND (arg0, 1)) | |
6653 | && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE | |
6654 | && ! TREE_CHAIN (arglist)) | |
6655 | return fold (build (code, type, | |
6656 | build1 (INDIRECT_REF, char_type_node, | |
6657 | TREE_VALUE(arglist)), | |
6658 | integer_zero_node)); | |
6659 | } | |
6660 | ||
e233264a | 6661 | /* From here on, the only cases we handle are when the result is |
6662 | known to be a constant. | |
6663 | ||
6664 | To compute GT, swap the arguments and do LT. | |
2bc77e10 | 6665 | To compute GE, do LT and invert the result. |
6666 | To compute LE, swap the arguments, do LT and invert the result. | |
e233264a | 6667 | To compute NE, do EQ and invert the result. |
6668 | ||
6669 | Therefore, the code below must handle only EQ and LT. */ | |
6670 | ||
2bc77e10 | 6671 | if (code == LE_EXPR || code == GT_EXPR) |
6672 | { | |
e233264a | 6673 | tem = arg0, arg0 = arg1, arg1 = tem; |
6674 | code = swap_tree_comparison (code); | |
6675 | } | |
6676 | ||
6677 | /* Note that it is safe to invert for real values here because we | |
6678 | will check below in the one case that it matters. */ | |
6679 | ||
155b05dc | 6680 | t1 = NULL_TREE; |
e233264a | 6681 | invert = 0; |
6682 | if (code == NE_EXPR || code == GE_EXPR) | |
6683 | { | |
6684 | invert = 1; | |
6685 | code = invert_tree_comparison (code); | |
2bc77e10 | 6686 | } |
6687 | ||
6688 | /* Compute a result for LT or EQ if args permit; | |
6689 | otherwise return T. */ | |
e233264a | 6690 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST) |
2bc77e10 | 6691 | { |
e233264a | 6692 | if (code == EQ_EXPR) |
a0c2c45b | 6693 | t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0); |
2bc77e10 | 6694 | else |
e233264a | 6695 | t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0)) |
6696 | ? INT_CST_LT_UNSIGNED (arg0, arg1) | |
6697 | : INT_CST_LT (arg0, arg1)), | |
6698 | 0); | |
2bc77e10 | 6699 | } |
e233264a | 6700 | |
ed74d475 | 6701 | #if 0 /* This is no longer useful, but breaks some real code. */ |
2bc77e10 | 6702 | /* Assume a nonexplicit constant cannot equal an explicit one, |
6703 | since such code would be undefined anyway. | |
6704 | Exception: on sysvr4, using #pragma weak, | |
6705 | a label can come out as 0. */ | |
6706 | else if (TREE_CODE (arg1) == INTEGER_CST | |
6707 | && !integer_zerop (arg1) | |
6708 | && TREE_CONSTANT (arg0) | |
6709 | && TREE_CODE (arg0) == ADDR_EXPR | |
e233264a | 6710 | && code == EQ_EXPR) |
6711 | t1 = build_int_2 (0, 0); | |
ed74d475 | 6712 | #endif |
2bc77e10 | 6713 | /* Two real constants can be compared explicitly. */ |
e233264a | 6714 | else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST) |
2bc77e10 | 6715 | { |
e233264a | 6716 | /* If either operand is a NaN, the result is false with two |
6717 | exceptions: First, an NE_EXPR is true on NaNs, but that case | |
6718 | is already handled correctly since we will be inverting the | |
6719 | result for NE_EXPR. Second, if we had inverted a LE_EXPR | |
6720 | or a GE_EXPR into a LT_EXPR, we must return true so that it | |
6721 | will be inverted into false. */ | |
6722 | ||
6723 | if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0)) | |
6724 | || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))) | |
6725 | t1 = build_int_2 (invert && code == LT_EXPR, 0); | |
6726 | ||
6727 | else if (code == EQ_EXPR) | |
6728 | t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0), | |
6729 | TREE_REAL_CST (arg1)), | |
6730 | 0); | |
2bc77e10 | 6731 | else |
e233264a | 6732 | t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0), |
6733 | TREE_REAL_CST (arg1)), | |
6734 | 0); | |
2bc77e10 | 6735 | } |
6736 | ||
e233264a | 6737 | if (t1 == NULL_TREE) |
6738 | return t; | |
6739 | ||
6740 | if (invert) | |
6741 | TREE_INT_CST_LOW (t1) ^= 1; | |
6742 | ||
6743 | TREE_TYPE (t1) = type; | |
ea56eec5 | 6744 | if (TREE_CODE (type) == BOOLEAN_TYPE) |
aff9e656 | 6745 | return (*lang_hooks.truthvalue_conversion) (t1); |
e233264a | 6746 | return t1; |
2bc77e10 | 6747 | |
6748 | case COND_EXPR: | |
56753054 | 6749 | /* Pedantic ANSI C says that a conditional expression is never an lvalue, |
6750 | so all simple results must be passed through pedantic_non_lvalue. */ | |
2bc77e10 | 6751 | if (TREE_CODE (arg0) == INTEGER_CST) |
56753054 | 6752 | return pedantic_non_lvalue |
6753 | (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1))); | |
2bc77e10 | 6754 | else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0)) |
6df5edfa | 6755 | return pedantic_omit_one_operand (type, arg1, arg0); |
2bc77e10 | 6756 | |
e233264a | 6757 | /* If the second operand is zero, invert the comparison and swap |
6758 | the second and third operands. Likewise if the second operand | |
6759 | is constant and the third is not or if the third operand is | |
6760 | equivalent to the first operand of the comparison. */ | |
2bc77e10 | 6761 | |
e233264a | 6762 | if (integer_zerop (arg1) |
6763 | || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2))) | |
6764 | || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<' | |
6765 | && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0), | |
6766 | TREE_OPERAND (t, 2), | |
6767 | TREE_OPERAND (arg0, 1)))) | |
6768 | { | |
6769 | /* See if this can be inverted. If it can't, possibly because | |
6770 | it was a floating-point inequality comparison, don't do | |
6771 | anything. */ | |
6772 | tem = invert_truthvalue (arg0); | |
2bc77e10 | 6773 | |
e233264a | 6774 | if (TREE_CODE (tem) != TRUTH_NOT_EXPR) |
6775 | { | |
f13f9c7f | 6776 | t = build (code, type, tem, |
6777 | TREE_OPERAND (t, 2), TREE_OPERAND (t, 1)); | |
6778 | arg0 = tem; | |
b3744b6b | 6779 | /* arg1 should be the first argument of the new T. */ |
6780 | arg1 = TREE_OPERAND (t, 1); | |
5923aeca | 6781 | STRIP_NOPS (arg1); |
e233264a | 6782 | } |
6783 | } | |
2bc77e10 | 6784 | |
e233264a | 6785 | /* If we have A op B ? A : C, we may be able to convert this to a |
6786 | simpler expression, depending on the operation and the values | |
920d0fb5 | 6787 | of B and C. Signed zeros prevent all of these transformations, |
6788 | for reasons given above each one. */ | |
2bc77e10 | 6789 | |
e233264a | 6790 | if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<' |
6791 | && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0), | |
920d0fb5 | 6792 | arg1, TREE_OPERAND (arg0, 1)) |
6793 | && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1)))) | |
2bc77e10 | 6794 | { |
e233264a | 6795 | tree arg2 = TREE_OPERAND (t, 2); |
6796 | enum tree_code comp_code = TREE_CODE (arg0); | |
6797 | ||
5923aeca | 6798 | STRIP_NOPS (arg2); |
6799 | ||
920d0fb5 | 6800 | /* If we have A op 0 ? A : -A, consider applying the following |
6801 | transformations: | |
6802 | ||
6803 | A == 0? A : -A same as -A | |
6804 | A != 0? A : -A same as A | |
6805 | A >= 0? A : -A same as abs (A) | |
6806 | A > 0? A : -A same as abs (A) | |
6807 | A <= 0? A : -A same as -abs (A) | |
6808 | A < 0? A : -A same as -abs (A) | |
6809 | ||
6810 | None of these transformations work for modes with signed | |
6811 | zeros. If A is +/-0, the first two transformations will | |
6812 | change the sign of the result (from +0 to -0, or vice | |
6813 | versa). The last four will fix the sign of the result, | |
6814 | even though the original expressions could be positive or | |
6815 | negative, depending on the sign of A. | |
6816 | ||
6817 | Note that all these transformations are correct if A is | |
6818 | NaN, since the two alternatives (A and -A) are also NaNs. */ | |
bdb341a3 | 6819 | if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1))) |
6820 | ? real_zerop (TREE_OPERAND (arg0, 1)) | |
6821 | : integer_zerop (TREE_OPERAND (arg0, 1))) | |
e233264a | 6822 | && TREE_CODE (arg2) == NEGATE_EXPR |
6823 | && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0)) | |
6824 | switch (comp_code) | |
6825 | { | |
6826 | case EQ_EXPR: | |
64a83102 | 6827 | return |
18bea959 | 6828 | pedantic_non_lvalue |
6829 | (convert (type, | |
6830 | negate_expr | |
6831 | (convert (TREE_TYPE (TREE_OPERAND (t, 1)), | |
6832 | arg1)))); | |
e233264a | 6833 | case NE_EXPR: |
56753054 | 6834 | return pedantic_non_lvalue (convert (type, arg1)); |
e233264a | 6835 | case GE_EXPR: |
6836 | case GT_EXPR: | |
f757c65c | 6837 | if (TREE_UNSIGNED (TREE_TYPE (arg1))) |
4070745f | 6838 | arg1 = convert ((*lang_hooks.types.signed_type) |
6839 | (TREE_TYPE (arg1)), arg1); | |
56753054 | 6840 | return pedantic_non_lvalue |
573bdf94 | 6841 | (convert (type, fold (build1 (ABS_EXPR, |
6842 | TREE_TYPE (arg1), arg1)))); | |
e233264a | 6843 | case LE_EXPR: |
6844 | case LT_EXPR: | |
f757c65c | 6845 | if (TREE_UNSIGNED (TREE_TYPE (arg1))) |
4070745f | 6846 | arg1 = convert ((lang_hooks.types.signed_type) |
6847 | (TREE_TYPE (arg1)), arg1); | |
56753054 | 6848 | return pedantic_non_lvalue |
23ec2d5e | 6849 | (negate_expr (convert (type, |
6850 | fold (build1 (ABS_EXPR, | |
6851 | TREE_TYPE (arg1), | |
6852 | arg1))))); | |
0dbd1c74 | 6853 | default: |
6854 | abort (); | |
e233264a | 6855 | } |
2bc77e10 | 6856 | |
920d0fb5 | 6857 | /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise |
6858 | A == 0 ? A : 0 is always 0 unless A is -0. Note that | |
6859 | both transformations are correct when A is NaN: A != 0 | |
6860 | is then true, and A == 0 is false. */ | |
2bc77e10 | 6861 | |
13cf6a4c | 6862 | if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2)) |
e233264a | 6863 | { |
6864 | if (comp_code == NE_EXPR) | |
56753054 | 6865 | return pedantic_non_lvalue (convert (type, arg1)); |
e233264a | 6866 | else if (comp_code == EQ_EXPR) |
56753054 | 6867 | return pedantic_non_lvalue (convert (type, integer_zero_node)); |
e233264a | 6868 | } |
6869 | ||
920d0fb5 | 6870 | /* Try some transformations of A op B ? A : B. |
6871 | ||
6872 | A == B? A : B same as B | |
6873 | A != B? A : B same as A | |
6874 | A >= B? A : B same as max (A, B) | |
6875 | A > B? A : B same as max (B, A) | |
6876 | A <= B? A : B same as min (A, B) | |
6877 | A < B? A : B same as min (B, A) | |
6878 | ||
6879 | As above, these transformations don't work in the presence | |
6880 | of signed zeros. For example, if A and B are zeros of | |
6881 | opposite sign, the first two transformations will change | |
6882 | the sign of the result. In the last four, the original | |
6883 | expressions give different results for (A=+0, B=-0) and | |
6884 | (A=-0, B=+0), but the transformed expressions do not. | |
6885 | ||
6886 | The first two transformations are correct if either A or B | |
6887 | is a NaN. In the first transformation, the condition will | |
6888 | be false, and B will indeed be chosen. In the case of the | |
6889 | second transformation, the condition A != B will be true, | |
6890 | and A will be chosen. | |
6891 | ||
6892 | The conversions to max() and min() are not correct if B is | |
6893 | a number and A is not. The conditions in the original | |
6894 | expressions will be false, so all four give B. The min() | |
6895 | and max() versions would give a NaN instead. */ | |
e233264a | 6896 | if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1), |
6897 | arg2, TREE_OPERAND (arg0, 0))) | |
5923aeca | 6898 | { |
6899 | tree comp_op0 = TREE_OPERAND (arg0, 0); | |
6900 | tree comp_op1 = TREE_OPERAND (arg0, 1); | |
6901 | tree comp_type = TREE_TYPE (comp_op0); | |
6902 | ||
5d8ac4eb | 6903 | /* Avoid adding NOP_EXPRs in case this is an lvalue. */ |
6904 | if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type)) | |
6905 | comp_type = type; | |
6906 | ||
5923aeca | 6907 | switch (comp_code) |
6908 | { | |
6909 | case EQ_EXPR: | |
6910 | return pedantic_non_lvalue (convert (type, arg2)); | |
6911 | case NE_EXPR: | |
6912 | return pedantic_non_lvalue (convert (type, arg1)); | |
6913 | case LE_EXPR: | |
6914 | case LT_EXPR: | |
0dbd1c74 | 6915 | /* In C++ a ?: expression can be an lvalue, so put the |
6916 | operand which will be used if they are equal first | |
cc049fa3 | 6917 | so that we can convert this back to the |
0dbd1c74 | 6918 | corresponding COND_EXPR. */ |
920d0fb5 | 6919 | if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))) |
6920 | return pedantic_non_lvalue | |
6921 | (convert (type, fold (build (MIN_EXPR, comp_type, | |
6922 | (comp_code == LE_EXPR | |
6923 | ? comp_op0 : comp_op1), | |
6924 | (comp_code == LE_EXPR | |
6925 | ? comp_op1 : comp_op0))))); | |
673abec3 | 6926 | break; |
5923aeca | 6927 | case GE_EXPR: |
6928 | case GT_EXPR: | |
920d0fb5 | 6929 | if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))) |
6930 | return pedantic_non_lvalue | |
6931 | (convert (type, fold (build (MAX_EXPR, comp_type, | |
6932 | (comp_code == GE_EXPR | |
6933 | ? comp_op0 : comp_op1), | |
6934 | (comp_code == GE_EXPR | |
6935 | ? comp_op1 : comp_op0))))); | |
673abec3 | 6936 | break; |
0dbd1c74 | 6937 | default: |
6938 | abort (); | |
5923aeca | 6939 | } |
6940 | } | |
e233264a | 6941 | |
6942 | /* If this is A op C1 ? A : C2 with C1 and C2 constant integers, | |
6943 | we might still be able to simplify this. For example, | |
6944 | if C1 is one less or one more than C2, this might have started | |
85761785 | 6945 | out as a MIN or MAX and been transformed by this function. |
780a4395 | 6946 | Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */ |
e233264a | 6947 | |
780a4395 | 6948 | if (INTEGRAL_TYPE_P (type) |
85761785 | 6949 | && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST |
e233264a | 6950 | && TREE_CODE (arg2) == INTEGER_CST) |
6951 | switch (comp_code) | |
6952 | { | |
6953 | case EQ_EXPR: | |
6954 | /* We can replace A with C1 in this case. */ | |
f13f9c7f | 6955 | arg1 = convert (type, TREE_OPERAND (arg0, 1)); |
6956 | t = build (code, type, TREE_OPERAND (t, 0), arg1, | |
6957 | TREE_OPERAND (t, 2)); | |
e233264a | 6958 | break; |
6959 | ||
6960 | case LT_EXPR: | |
6961 | /* If C1 is C2 + 1, this is min(A, C2). */ | |
6962 | if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1) | |
6963 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
6964 | const_binop (PLUS_EXPR, arg2, | |
5485823f | 6965 | integer_one_node, 0), 1)) |
56753054 | 6966 | return pedantic_non_lvalue |
6967 | (fold (build (MIN_EXPR, type, arg1, arg2))); | |
e233264a | 6968 | break; |
6969 | ||
6970 | case LE_EXPR: | |
6971 | /* If C1 is C2 - 1, this is min(A, C2). */ | |
6972 | if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1) | |
6973 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
6974 | const_binop (MINUS_EXPR, arg2, | |
5485823f | 6975 | integer_one_node, 0), 1)) |
56753054 | 6976 | return pedantic_non_lvalue |
6977 | (fold (build (MIN_EXPR, type, arg1, arg2))); | |
e233264a | 6978 | break; |
6979 | ||
6980 | case GT_EXPR: | |
6981 | /* If C1 is C2 - 1, this is max(A, C2). */ | |
6982 | if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1) | |
6983 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
6984 | const_binop (MINUS_EXPR, arg2, | |
5485823f | 6985 | integer_one_node, 0), 1)) |
56753054 | 6986 | return pedantic_non_lvalue |
6987 | (fold (build (MAX_EXPR, type, arg1, arg2))); | |
e233264a | 6988 | break; |
6989 | ||
6990 | case GE_EXPR: | |
6991 | /* If C1 is C2 + 1, this is max(A, C2). */ | |
6992 | if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1) | |
6993 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
6994 | const_binop (PLUS_EXPR, arg2, | |
5485823f | 6995 | integer_one_node, 0), 1)) |
56753054 | 6996 | return pedantic_non_lvalue |
6997 | (fold (build (MAX_EXPR, type, arg1, arg2))); | |
e233264a | 6998 | break; |
0dbd1c74 | 6999 | case NE_EXPR: |
7000 | break; | |
7001 | default: | |
7002 | abort (); | |
e233264a | 7003 | } |
2bc77e10 | 7004 | } |
7005 | ||
2483911d | 7006 | /* If the second operand is simpler than the third, swap them |
7007 | since that produces better jump optimization results. */ | |
9308e976 | 7008 | if ((TREE_CONSTANT (arg1) || DECL_P (arg1) |
2483911d | 7009 | || TREE_CODE (arg1) == SAVE_EXPR) |
7010 | && ! (TREE_CONSTANT (TREE_OPERAND (t, 2)) | |
9308e976 | 7011 | || DECL_P (TREE_OPERAND (t, 2)) |
2483911d | 7012 | || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR)) |
7013 | { | |
7014 | /* See if this can be inverted. If it can't, possibly because | |
7015 | it was a floating-point inequality comparison, don't do | |
7016 | anything. */ | |
7017 | tem = invert_truthvalue (arg0); | |
7018 | ||
7019 | if (TREE_CODE (tem) != TRUTH_NOT_EXPR) | |
7020 | { | |
f13f9c7f | 7021 | t = build (code, type, tem, |
7022 | TREE_OPERAND (t, 2), TREE_OPERAND (t, 1)); | |
7023 | arg0 = tem; | |
f3391f1b | 7024 | /* arg1 should be the first argument of the new T. */ |
7025 | arg1 = TREE_OPERAND (t, 1); | |
5923aeca | 7026 | STRIP_NOPS (arg1); |
2483911d | 7027 | } |
7028 | } | |
7029 | ||
e233264a | 7030 | /* Convert A ? 1 : 0 to simply A. */ |
7031 | if (integer_onep (TREE_OPERAND (t, 1)) | |
7032 | && integer_zerop (TREE_OPERAND (t, 2)) | |
7033 | /* If we try to convert TREE_OPERAND (t, 0) to our type, the | |
cc049fa3 | 7034 | call to fold will try to move the conversion inside |
e233264a | 7035 | a COND, which will recurse. In that case, the COND_EXPR |
7036 | is probably the best choice, so leave it alone. */ | |
7037 | && type == TREE_TYPE (arg0)) | |
56753054 | 7038 | return pedantic_non_lvalue (arg0); |
2bc77e10 | 7039 | |
7687025a | 7040 | /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR |
7041 | over COND_EXPR in cases such as floating point comparisons. */ | |
7042 | if (integer_zerop (TREE_OPERAND (t, 1)) | |
7043 | && integer_onep (TREE_OPERAND (t, 2)) | |
7044 | && truth_value_p (TREE_CODE (arg0))) | |
7045 | return pedantic_non_lvalue (convert (type, | |
7046 | invert_truthvalue (arg0))); | |
7047 | ||
e233264a | 7048 | /* Look for expressions of the form A & 2 ? 2 : 0. The result of this |
7049 | operation is simply A & 2. */ | |
2bc77e10 | 7050 | |
7051 | if (integer_zerop (TREE_OPERAND (t, 2)) | |
7052 | && TREE_CODE (arg0) == NE_EXPR | |
7053 | && integer_zerop (TREE_OPERAND (arg0, 1)) | |
e233264a | 7054 | && integer_pow2p (arg1) |
7055 | && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR | |
7056 | && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1), | |
7057 | arg1, 1)) | |
56753054 | 7058 | return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0))); |
2bc77e10 | 7059 | |
7687025a | 7060 | /* Convert A ? B : 0 into A && B if A and B are truth values. */ |
7061 | if (integer_zerop (TREE_OPERAND (t, 2)) | |
7062 | && truth_value_p (TREE_CODE (arg0)) | |
7063 | && truth_value_p (TREE_CODE (arg1))) | |
7064 | return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR, type, | |
7065 | arg0, arg1))); | |
7066 | ||
7067 | /* Convert A ? B : 1 into !A || B if A and B are truth values. */ | |
7068 | if (integer_onep (TREE_OPERAND (t, 2)) | |
7069 | && truth_value_p (TREE_CODE (arg0)) | |
7070 | && truth_value_p (TREE_CODE (arg1))) | |
7071 | { | |
7072 | /* Only perform transformation if ARG0 is easily inverted. */ | |
7073 | tem = invert_truthvalue (arg0); | |
7074 | if (TREE_CODE (tem) != TRUTH_NOT_EXPR) | |
7075 | return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR, type, | |
7076 | tem, arg1))); | |
7077 | } | |
7078 | ||
2bc77e10 | 7079 | return t; |
7080 | ||
7081 | case COMPOUND_EXPR: | |
b468bbc6 | 7082 | /* When pedantic, a compound expression can be neither an lvalue |
7083 | nor an integer constant expression. */ | |
7084 | if (TREE_SIDE_EFFECTS (arg0) || pedantic) | |
c3ce5d04 | 7085 | return t; |
7086 | /* Don't let (0, 0) be null pointer constant. */ | |
7087 | if (integer_zerop (arg1)) | |
3a6656ad | 7088 | return build1 (NOP_EXPR, type, arg1); |
7089 | return convert (type, arg1); | |
2bc77e10 | 7090 | |
bb6b5123 | 7091 | case COMPLEX_EXPR: |
7092 | if (wins) | |
5b2ade4d | 7093 | return build_complex (type, arg0, arg1); |
bb6b5123 | 7094 | return t; |
7095 | ||
7096 | case REALPART_EXPR: | |
27395c25 | 7097 | if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE) |
bb6b5123 | 7098 | return t; |
7099 | else if (TREE_CODE (arg0) == COMPLEX_EXPR) | |
7100 | return omit_one_operand (type, TREE_OPERAND (arg0, 0), | |
7101 | TREE_OPERAND (arg0, 1)); | |
7102 | else if (TREE_CODE (arg0) == COMPLEX_CST) | |
7103 | return TREE_REALPART (arg0); | |
7104 | else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR) | |
a1397da2 | 7105 | return fold (build (TREE_CODE (arg0), type, |
7106 | fold (build1 (REALPART_EXPR, type, | |
7107 | TREE_OPERAND (arg0, 0))), | |
7108 | fold (build1 (REALPART_EXPR, | |
7109 | type, TREE_OPERAND (arg0, 1))))); | |
bb6b5123 | 7110 | return t; |
7111 | ||
7112 | case IMAGPART_EXPR: | |
27395c25 | 7113 | if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE) |
bb6b5123 | 7114 | return convert (type, integer_zero_node); |
7115 | else if (TREE_CODE (arg0) == COMPLEX_EXPR) | |
7116 | return omit_one_operand (type, TREE_OPERAND (arg0, 1), | |
7117 | TREE_OPERAND (arg0, 0)); | |
7118 | else if (TREE_CODE (arg0) == COMPLEX_CST) | |
7119 | return TREE_IMAGPART (arg0); | |
7120 | else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR) | |
a1397da2 | 7121 | return fold (build (TREE_CODE (arg0), type, |
7122 | fold (build1 (IMAGPART_EXPR, type, | |
7123 | TREE_OPERAND (arg0, 0))), | |
7124 | fold (build1 (IMAGPART_EXPR, type, | |
7125 | TREE_OPERAND (arg0, 1))))); | |
bb6b5123 | 7126 | return t; |
7127 | ||
49f9d16d | 7128 | /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where |
7129 | appropriate. */ | |
7130 | case CLEANUP_POINT_EXPR: | |
bc280274 | 7131 | if (! has_cleanups (arg0)) |
47853bac | 7132 | return TREE_OPERAND (t, 0); |
49f9d16d | 7133 | |
7134 | { | |
7135 | enum tree_code code0 = TREE_CODE (arg0); | |
7136 | int kind0 = TREE_CODE_CLASS (code0); | |
7137 | tree arg00 = TREE_OPERAND (arg0, 0); | |
7138 | tree arg01; | |
7139 | ||
154e6f12 | 7140 | if (kind0 == '1' || code0 == TRUTH_NOT_EXPR) |
cc049fa3 | 7141 | return fold (build1 (code0, type, |
49f9d16d | 7142 | fold (build1 (CLEANUP_POINT_EXPR, |
7143 | TREE_TYPE (arg00), arg00)))); | |
154e6f12 | 7144 | |
7145 | if (kind0 == '<' || kind0 == '2' | |
7146 | || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR | |
7147 | || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR | |
7148 | || code0 == TRUTH_XOR_EXPR) | |
7149 | { | |
7150 | arg01 = TREE_OPERAND (arg0, 1); | |
7151 | ||
bc280274 | 7152 | if (TREE_CONSTANT (arg00) |
7153 | || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR) | |
7154 | && ! has_cleanups (arg00))) | |
154e6f12 | 7155 | return fold (build (code0, type, arg00, |
7156 | fold (build1 (CLEANUP_POINT_EXPR, | |
7157 | TREE_TYPE (arg01), arg01)))); | |
7158 | ||
bc280274 | 7159 | if (TREE_CONSTANT (arg01)) |
154e6f12 | 7160 | return fold (build (code0, type, |
7161 | fold (build1 (CLEANUP_POINT_EXPR, | |
7162 | TREE_TYPE (arg00), arg00)), | |
7163 | arg01)); | |
7164 | } | |
49f9d16d | 7165 | |
7166 | return t; | |
7167 | } | |
7168 | ||
650e4c94 | 7169 | case CALL_EXPR: |
7170 | /* Check for a built-in function. */ | |
7171 | if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR | |
7172 | && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr, 0), 0)) | |
7173 | == FUNCTION_DECL) | |
7174 | && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr, 0), 0))) | |
7175 | { | |
7176 | tree tmp = fold_builtin (expr); | |
7177 | if (tmp) | |
7178 | return tmp; | |
7179 | } | |
7180 | return t; | |
7181 | ||
2bc77e10 | 7182 | default: |
7183 | return t; | |
7184 | } /* switch (code) */ | |
7185 | } | |
76a0ced5 | 7186 | |
7014838c | 7187 | /* Determine if first argument is a multiple of second argument. Return 0 if |
7188 | it is not, or we cannot easily determined it to be. | |
76a0ced5 | 7189 | |
7014838c | 7190 | An example of the sort of thing we care about (at this point; this routine |
7191 | could surely be made more general, and expanded to do what the *_DIV_EXPR's | |
7192 | fold cases do now) is discovering that | |
76a0ced5 | 7193 | |
7194 | SAVE_EXPR (I) * SAVE_EXPR (J * 8) | |
7195 | ||
7196 | is a multiple of | |
7197 | ||
7198 | SAVE_EXPR (J * 8) | |
7199 | ||
7014838c | 7200 | when we know that the two SAVE_EXPR (J * 8) nodes are the same node. |
76a0ced5 | 7201 | |
7202 | This code also handles discovering that | |
7203 | ||
7204 | SAVE_EXPR (I) * SAVE_EXPR (J * 8) | |
7205 | ||
7014838c | 7206 | is a multiple of 8 so we don't have to worry about dealing with a |
76a0ced5 | 7207 | possible remainder. |
7208 | ||
7014838c | 7209 | Note that we *look* inside a SAVE_EXPR only to determine how it was |
7210 | calculated; it is not safe for fold to do much of anything else with the | |
7211 | internals of a SAVE_EXPR, since it cannot know when it will be evaluated | |
7212 | at run time. For example, the latter example above *cannot* be implemented | |
7213 | as SAVE_EXPR (I) * J or any variant thereof, since the value of J at | |
7214 | evaluation time of the original SAVE_EXPR is not necessarily the same at | |
7215 | the time the new expression is evaluated. The only optimization of this | |
76a0ced5 | 7216 | sort that would be valid is changing |
7217 | ||
7218 | SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8) | |
76a0ced5 | 7219 | |
7014838c | 7220 | divided by 8 to |
76a0ced5 | 7221 | |
7222 | SAVE_EXPR (I) * SAVE_EXPR (J) | |
7223 | ||
7224 | (where the same SAVE_EXPR (J) is used in the original and the | |
7225 | transformed version). */ | |
7226 | ||
7227 | static int | |
7228 | multiple_of_p (type, top, bottom) | |
7229 | tree type; | |
7230 | tree top; | |
7231 | tree bottom; | |
7232 | { | |
7233 | if (operand_equal_p (top, bottom, 0)) | |
7234 | return 1; | |
7235 | ||
7236 | if (TREE_CODE (type) != INTEGER_TYPE) | |
7237 | return 0; | |
7238 | ||
7239 | switch (TREE_CODE (top)) | |
7240 | { | |
7241 | case MULT_EXPR: | |
7242 | return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom) | |
7243 | || multiple_of_p (type, TREE_OPERAND (top, 1), bottom)); | |
7244 | ||
7245 | case PLUS_EXPR: | |
7246 | case MINUS_EXPR: | |
7247 | return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom) | |
7248 | && multiple_of_p (type, TREE_OPERAND (top, 1), bottom)); | |
7249 | ||
17e3940f | 7250 | case LSHIFT_EXPR: |
7251 | if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST) | |
7252 | { | |
7253 | tree op1, t1; | |
7254 | ||
7255 | op1 = TREE_OPERAND (top, 1); | |
7256 | /* const_binop may not detect overflow correctly, | |
7257 | so check for it explicitly here. */ | |
7258 | if (TYPE_PRECISION (TREE_TYPE (size_one_node)) | |
7259 | > TREE_INT_CST_LOW (op1) | |
7260 | && TREE_INT_CST_HIGH (op1) == 0 | |
7261 | && 0 != (t1 = convert (type, | |
7262 | const_binop (LSHIFT_EXPR, size_one_node, | |
7263 | op1, 0))) | |
7264 | && ! TREE_OVERFLOW (t1)) | |
7265 | return multiple_of_p (type, t1, bottom); | |
7266 | } | |
7267 | return 0; | |
7268 | ||
76a0ced5 | 7269 | case NOP_EXPR: |
7014838c | 7270 | /* Can't handle conversions from non-integral or wider integral type. */ |
76a0ced5 | 7271 | if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE) |
7272 | || (TYPE_PRECISION (type) | |
7273 | < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0))))) | |
7274 | return 0; | |
7014838c | 7275 | |
6312a35e | 7276 | /* .. fall through ... */ |
7014838c | 7277 | |
76a0ced5 | 7278 | case SAVE_EXPR: |
7279 | return multiple_of_p (type, TREE_OPERAND (top, 0), bottom); | |
7280 | ||
7281 | case INTEGER_CST: | |
17e3940f | 7282 | if (TREE_CODE (bottom) != INTEGER_CST |
7283 | || (TREE_UNSIGNED (type) | |
7284 | && (tree_int_cst_sgn (top) < 0 | |
7285 | || tree_int_cst_sgn (bottom) < 0))) | |
76a0ced5 | 7286 | return 0; |
7287 | return integer_zerop (const_binop (TRUNC_MOD_EXPR, | |
7288 | top, bottom, 0)); | |
7289 | ||
7290 | default: | |
7291 | return 0; | |
7292 | } | |
7293 | } | |
0f221fb7 | 7294 | |
7295 | /* Return true if `t' is known to be non-negative. */ | |
7296 | ||
7297 | int | |
7298 | tree_expr_nonnegative_p (t) | |
7299 | tree t; | |
7300 | { | |
7301 | switch (TREE_CODE (t)) | |
7302 | { | |
cde9d0c7 | 7303 | case ABS_EXPR: |
7304 | case FFS_EXPR: | |
7305 | return 1; | |
0f221fb7 | 7306 | case INTEGER_CST: |
7307 | return tree_int_cst_sgn (t) >= 0; | |
a9436f5c | 7308 | case TRUNC_DIV_EXPR: |
7309 | case CEIL_DIV_EXPR: | |
7310 | case FLOOR_DIV_EXPR: | |
7311 | case ROUND_DIV_EXPR: | |
7312 | return tree_expr_nonnegative_p (TREE_OPERAND (t, 0)) | |
d3371fcd | 7313 | && tree_expr_nonnegative_p (TREE_OPERAND (t, 1)); |
a9436f5c | 7314 | case TRUNC_MOD_EXPR: |
7315 | case CEIL_MOD_EXPR: | |
7316 | case FLOOR_MOD_EXPR: | |
7317 | case ROUND_MOD_EXPR: | |
7318 | return tree_expr_nonnegative_p (TREE_OPERAND (t, 0)); | |
0f221fb7 | 7319 | case COND_EXPR: |
7320 | return tree_expr_nonnegative_p (TREE_OPERAND (t, 1)) | |
7321 | && tree_expr_nonnegative_p (TREE_OPERAND (t, 2)); | |
cde9d0c7 | 7322 | case COMPOUND_EXPR: |
7323 | return tree_expr_nonnegative_p (TREE_OPERAND (t, 1)); | |
7324 | case MIN_EXPR: | |
7325 | return tree_expr_nonnegative_p (TREE_OPERAND (t, 0)) | |
d3371fcd | 7326 | && tree_expr_nonnegative_p (TREE_OPERAND (t, 1)); |
cde9d0c7 | 7327 | case MAX_EXPR: |
7328 | return tree_expr_nonnegative_p (TREE_OPERAND (t, 0)) | |
d3371fcd | 7329 | || tree_expr_nonnegative_p (TREE_OPERAND (t, 1)); |
cde9d0c7 | 7330 | case MODIFY_EXPR: |
7331 | return tree_expr_nonnegative_p (TREE_OPERAND (t, 1)); | |
0f221fb7 | 7332 | case BIND_EXPR: |
7333 | return tree_expr_nonnegative_p (TREE_OPERAND (t, 1)); | |
a9436f5c | 7334 | case SAVE_EXPR: |
7335 | return tree_expr_nonnegative_p (TREE_OPERAND (t, 0)); | |
7336 | case NON_LVALUE_EXPR: | |
7337 | return tree_expr_nonnegative_p (TREE_OPERAND (t, 0)); | |
0f221fb7 | 7338 | case RTL_EXPR: |
7339 | return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t)); | |
d3371fcd | 7340 | |
0f221fb7 | 7341 | default: |
88e6440b | 7342 | if (truth_value_p (TREE_CODE (t))) |
7343 | /* Truth values evaluate to 0 or 1, which is nonnegative. */ | |
7344 | return 1; | |
7345 | else | |
7346 | /* We don't know sign of `t', so be conservative and return false. */ | |
7347 | return 0; | |
0f221fb7 | 7348 | } |
7349 | } | |
7350 | ||
7351 | /* Return true if `r' is known to be non-negative. | |
7352 | Only handles constants at the moment. */ | |
7353 | ||
7354 | int | |
7355 | rtl_expr_nonnegative_p (r) | |
7356 | rtx r; | |
7357 | { | |
7358 | switch (GET_CODE (r)) | |
7359 | { | |
7360 | case CONST_INT: | |
7361 | return INTVAL (r) >= 0; | |
7362 | ||
7363 | case CONST_DOUBLE: | |
7364 | if (GET_MODE (r) == VOIDmode) | |
7365 | return CONST_DOUBLE_HIGH (r) >= 0; | |
7366 | return 0; | |
7367 | ||
886cfd4f | 7368 | case CONST_VECTOR: |
7369 | { | |
7370 | int units, i; | |
7371 | rtx elt; | |
7372 | ||
7373 | units = CONST_VECTOR_NUNITS (r); | |
7374 | ||
7375 | for (i = 0; i < units; ++i) | |
7376 | { | |
7377 | elt = CONST_VECTOR_ELT (r, i); | |
7378 | if (!rtl_expr_nonnegative_p (elt)) | |
7379 | return 0; | |
7380 | } | |
7381 | ||
7382 | return 1; | |
7383 | } | |
7384 | ||
0f221fb7 | 7385 | case SYMBOL_REF: |
7386 | case LABEL_REF: | |
7387 | /* These are always nonnegative. */ | |
7388 | return 1; | |
7389 | ||
7390 | default: | |
7391 | return 0; | |
7392 | } | |
7393 | } | |
1f3233d1 | 7394 | |
7395 | #include "gt-fold-const.h" |