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Commit | Line | Data |
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6d716ca8 RS |
1 | /* Fold a constant sub-tree into a single node for C-compiler |
2 | Copyright (C) 1987, 1988, 1992 Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of GNU CC. | |
5 | ||
6 | GNU CC is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GNU CC is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GNU CC; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
19 | ||
20 | /*@@ Fix lossage on folding division of big integers. */ | |
21 | ||
6dc42e49 | 22 | /*@@ This file should be rewritten to use an arbitrary precision |
6d716ca8 RS |
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 | ||
30 | ||
31 | /* The entry points in this file are fold, size_int and size_binop. | |
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 | |
40 | with type from `sizetype'. */ | |
41 | ||
42 | #include <stdio.h> | |
43 | #include <setjmp.h> | |
44 | #include "config.h" | |
45 | #include "flags.h" | |
46 | #include "tree.h" | |
47 | ||
7c7b029d RS |
48 | /* Handle floating overflow for `const_binop'. */ |
49 | static jmp_buf float_error; | |
50 | ||
fe3e8e40 | 51 | int lshift_double (); |
6d716ca8 RS |
52 | void rshift_double (); |
53 | void lrotate_double (); | |
54 | void rrotate_double (); | |
55 | static tree const_binop (); | |
d35357ed RS |
56 | |
57 | #ifndef BRANCH_COST | |
58 | #define BRANCH_COST 1 | |
59 | #endif | |
fe3e8e40 RS |
60 | |
61 | /* Yield nonzero if a signed left shift of A by B bits overflows. */ | |
62 | #define left_shift_overflows(a, b) ((a) != ((a) << (b)) >> (b)) | |
63 | ||
64 | /* Yield nonzero if A and B have the same sign. */ | |
65 | #define same_sign(a, b) ((a) ^ (b) >= 0) | |
66 | ||
67 | /* Suppose A1 + B1 = SUM1, using 2's complement arithmetic ignoring overflow. | |
68 | Suppose A, B and SUM have the same respective signs as A1, B1, and SUM1. | |
69 | Then this yields nonzero if overflow occurred during the addition. | |
70 | Overflow occurs if A and B have the same sign, but A and SUM differ in sign. | |
71 | Use `^' to test whether signs differ, and `< 0' to isolate the sign. */ | |
72 | #define overflow_sum_sign(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0) | |
6d716ca8 | 73 | \f |
906c4e36 RK |
74 | /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic. |
75 | We do that by representing the two-word integer as MAX_SHORTS shorts, | |
6d716ca8 RS |
76 | with only 8 bits stored in each short, as a positive number. */ |
77 | ||
906c4e36 RK |
78 | /* Unpack a two-word integer into MAX_SHORTS shorts. |
79 | LOW and HI are the integer, as two `HOST_WIDE_INT' pieces. | |
6d716ca8 RS |
80 | SHORTS points to the array of shorts. */ |
81 | ||
82 | static void | |
83 | encode (shorts, low, hi) | |
84 | short *shorts; | |
906c4e36 | 85 | HOST_WIDE_INT low, hi; |
6d716ca8 | 86 | { |
906c4e36 RK |
87 | register int i; |
88 | ||
89 | for (i = 0; i < MAX_SHORTS / 2; i++) | |
90 | { | |
91 | shorts[i] = (low >> (i * 8)) & 0xff; | |
92 | shorts[i + MAX_SHORTS / 2] = (hi >> (i * 8) & 0xff); | |
93 | } | |
6d716ca8 RS |
94 | } |
95 | ||
906c4e36 | 96 | /* Pack an array of MAX_SHORTS shorts into a two-word integer. |
6d716ca8 | 97 | SHORTS points to the array of shorts. |
906c4e36 | 98 | The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */ |
6d716ca8 RS |
99 | |
100 | static void | |
101 | decode (shorts, low, hi) | |
102 | short *shorts; | |
906c4e36 | 103 | HOST_WIDE_INT *low, *hi; |
6d716ca8 | 104 | { |
906c4e36 RK |
105 | register int i; |
106 | HOST_WIDE_INT lv = 0, hv = 0; | |
107 | ||
108 | for (i = 0; i < MAX_SHORTS / 2; i++) | |
109 | { | |
110 | lv |= (HOST_WIDE_INT) shorts[i] << (i * 8); | |
111 | hv |= (HOST_WIDE_INT) shorts[i + MAX_SHORTS / 2] << (i * 8); | |
112 | } | |
113 | ||
114 | *low = lv, *hi = hv; | |
6d716ca8 RS |
115 | } |
116 | \f | |
117 | /* Make the integer constant T valid for its type | |
118 | by setting to 0 or 1 all the bits in the constant | |
119 | that don't belong in the type. */ | |
120 | ||
121 | static void | |
122 | force_fit_type (t) | |
123 | tree t; | |
124 | { | |
125 | register int prec = TYPE_PRECISION (TREE_TYPE (t)); | |
126 | ||
127 | if (TREE_CODE (TREE_TYPE (t)) == POINTER_TYPE) | |
128 | prec = POINTER_SIZE; | |
129 | ||
130 | /* First clear all bits that are beyond the type's precision. */ | |
131 | ||
906c4e36 | 132 | if (prec == 2 * HOST_BITS_PER_WIDE_INT) |
6d716ca8 | 133 | ; |
906c4e36 | 134 | else if (prec > HOST_BITS_PER_WIDE_INT) |
6d716ca8 RS |
135 | { |
136 | TREE_INT_CST_HIGH (t) | |
906c4e36 | 137 | &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT)); |
6d716ca8 RS |
138 | } |
139 | else | |
140 | { | |
141 | TREE_INT_CST_HIGH (t) = 0; | |
906c4e36 RK |
142 | if (prec < HOST_BITS_PER_WIDE_INT) |
143 | TREE_INT_CST_LOW (t) &= ~((HOST_WIDE_INT) (-1) << prec); | |
6d716ca8 RS |
144 | } |
145 | ||
146 | /* If it's a signed type and value's sign bit is set, extend the sign. */ | |
147 | ||
148 | if (! TREE_UNSIGNED (TREE_TYPE (t)) | |
906c4e36 RK |
149 | && prec != 2 * HOST_BITS_PER_WIDE_INT |
150 | && (prec > HOST_BITS_PER_WIDE_INT | |
151 | ? (TREE_INT_CST_HIGH (t) | |
152 | & ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1))) | |
153 | : TREE_INT_CST_LOW (t) & ((HOST_WIDE_INT) 1 << (prec - 1)))) | |
6d716ca8 RS |
154 | { |
155 | /* Value is negative: | |
156 | set to 1 all the bits that are outside this type's precision. */ | |
906c4e36 | 157 | if (prec > HOST_BITS_PER_WIDE_INT) |
6d716ca8 RS |
158 | { |
159 | TREE_INT_CST_HIGH (t) | |
906c4e36 | 160 | |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT)); |
6d716ca8 RS |
161 | } |
162 | else | |
163 | { | |
164 | TREE_INT_CST_HIGH (t) = -1; | |
906c4e36 RK |
165 | if (prec < HOST_BITS_PER_WIDE_INT) |
166 | TREE_INT_CST_LOW (t) |= ((HOST_WIDE_INT) (-1) << prec); | |
6d716ca8 RS |
167 | } |
168 | } | |
169 | } | |
170 | \f | |
906c4e36 RK |
171 | /* Add two doubleword integers with doubleword result. |
172 | Each argument is given as two `HOST_WIDE_INT' pieces. | |
6d716ca8 | 173 | One argument is L1 and H1; the other, L2 and H2. |
906c4e36 | 174 | The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. |
6d716ca8 RS |
175 | We use the 8-shorts representation internally. */ |
176 | ||
fe3e8e40 | 177 | int |
6d716ca8 | 178 | add_double (l1, h1, l2, h2, lv, hv) |
906c4e36 RK |
179 | HOST_WIDE_INT l1, h1, l2, h2; |
180 | HOST_WIDE_INT *lv, *hv; | |
6d716ca8 | 181 | { |
906c4e36 RK |
182 | short arg1[MAX_SHORTS]; |
183 | short arg2[MAX_SHORTS]; | |
6d716ca8 RS |
184 | register int carry = 0; |
185 | register int i; | |
186 | ||
187 | encode (arg1, l1, h1); | |
188 | encode (arg2, l2, h2); | |
189 | ||
906c4e36 | 190 | for (i = 0; i < MAX_SHORTS; i++) |
6d716ca8 RS |
191 | { |
192 | carry += arg1[i] + arg2[i]; | |
193 | arg1[i] = carry & 0xff; | |
194 | carry >>= 8; | |
195 | } | |
196 | ||
197 | decode (arg1, lv, hv); | |
fe3e8e40 | 198 | return overflow_sum_sign (h1, h2, *hv); |
6d716ca8 RS |
199 | } |
200 | ||
906c4e36 | 201 | /* Negate a doubleword integer with doubleword result. |
fe3e8e40 | 202 | Return nonzero if the operation overflows, assuming it's signed. |
906c4e36 RK |
203 | The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1. |
204 | The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. | |
6d716ca8 RS |
205 | We use the 8-shorts representation internally. */ |
206 | ||
fe3e8e40 | 207 | int |
6d716ca8 | 208 | neg_double (l1, h1, lv, hv) |
906c4e36 RK |
209 | HOST_WIDE_INT l1, h1; |
210 | HOST_WIDE_INT *lv, *hv; | |
6d716ca8 RS |
211 | { |
212 | if (l1 == 0) | |
213 | { | |
214 | *lv = 0; | |
215 | *hv = - h1; | |
fe3e8e40 | 216 | return same_sign (h1, *hv); |
6d716ca8 RS |
217 | } |
218 | else | |
219 | { | |
220 | *lv = - l1; | |
221 | *hv = ~ h1; | |
fe3e8e40 | 222 | return 0; |
6d716ca8 RS |
223 | } |
224 | } | |
225 | \f | |
906c4e36 | 226 | /* Multiply two doubleword integers with doubleword result. |
fe3e8e40 | 227 | Return nonzero if the operation overflows, assuming it's signed. |
906c4e36 | 228 | Each argument is given as two `HOST_WIDE_INT' pieces. |
6d716ca8 | 229 | One argument is L1 and H1; the other, L2 and H2. |
906c4e36 | 230 | The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. |
6d716ca8 RS |
231 | We use the 8-shorts representation internally. */ |
232 | ||
fe3e8e40 | 233 | int |
6d716ca8 | 234 | mul_double (l1, h1, l2, h2, lv, hv) |
906c4e36 RK |
235 | HOST_WIDE_INT l1, h1, l2, h2; |
236 | HOST_WIDE_INT *lv, *hv; | |
6d716ca8 | 237 | { |
906c4e36 RK |
238 | short arg1[MAX_SHORTS]; |
239 | short arg2[MAX_SHORTS]; | |
240 | short prod[MAX_SHORTS * 2]; | |
6d716ca8 RS |
241 | register int carry = 0; |
242 | register int i, j, k; | |
fe3e8e40 | 243 | HOST_WIDE_INT toplow, tophigh, neglow, neghigh; |
6d716ca8 | 244 | |
fe3e8e40 | 245 | /* These cases are used extensively, arising from pointer combinations. */ |
6d716ca8 RS |
246 | if (h2 == 0) |
247 | { | |
248 | if (l2 == 2) | |
249 | { | |
fe3e8e40 | 250 | int overflow = left_shift_overflows (h1, 1); |
906c4e36 | 251 | unsigned HOST_WIDE_INT temp = l1 + l1; |
fe3e8e40 | 252 | *hv = (h1 << 1) + (temp < l1); |
6d716ca8 | 253 | *lv = temp; |
fe3e8e40 | 254 | return overflow; |
6d716ca8 RS |
255 | } |
256 | if (l2 == 4) | |
257 | { | |
fe3e8e40 | 258 | int overflow = left_shift_overflows (h1, 2); |
906c4e36 | 259 | unsigned HOST_WIDE_INT temp = l1 + l1; |
fe3e8e40 | 260 | h1 = (h1 << 2) + ((temp < l1) << 1); |
6d716ca8 RS |
261 | l1 = temp; |
262 | temp += temp; | |
263 | h1 += (temp < l1); | |
264 | *lv = temp; | |
265 | *hv = h1; | |
fe3e8e40 | 266 | return overflow; |
6d716ca8 RS |
267 | } |
268 | if (l2 == 8) | |
269 | { | |
fe3e8e40 | 270 | int overflow = left_shift_overflows (h1, 3); |
906c4e36 | 271 | unsigned HOST_WIDE_INT temp = l1 + l1; |
fe3e8e40 | 272 | h1 = (h1 << 3) + ((temp < l1) << 2); |
6d716ca8 RS |
273 | l1 = temp; |
274 | temp += temp; | |
275 | h1 += (temp < l1) << 1; | |
276 | l1 = temp; | |
277 | temp += temp; | |
278 | h1 += (temp < l1); | |
279 | *lv = temp; | |
280 | *hv = h1; | |
fe3e8e40 | 281 | return overflow; |
6d716ca8 RS |
282 | } |
283 | } | |
284 | ||
285 | encode (arg1, l1, h1); | |
286 | encode (arg2, l2, h2); | |
287 | ||
288 | bzero (prod, sizeof prod); | |
289 | ||
906c4e36 RK |
290 | for (i = 0; i < MAX_SHORTS; i++) |
291 | for (j = 0; j < MAX_SHORTS; j++) | |
6d716ca8 RS |
292 | { |
293 | k = i + j; | |
294 | carry = arg1[i] * arg2[j]; | |
295 | while (carry) | |
296 | { | |
297 | carry += prod[k]; | |
298 | prod[k] = carry & 0xff; | |
299 | carry >>= 8; | |
300 | k++; | |
301 | } | |
302 | } | |
303 | ||
fe3e8e40 | 304 | decode (prod, lv, hv); /* This ignores |
906c4e36 | 305 | prod[MAX_SHORTS] -> prod[MAX_SHORTS*2-1] */ |
fe3e8e40 RS |
306 | |
307 | /* Check for overflow by calculating the top half of the answer in full; | |
308 | it should agree with the low half's sign bit. */ | |
309 | decode (prod+MAX_SHORTS, &toplow, &tophigh); | |
310 | if (h1 < 0) | |
311 | { | |
312 | neg_double (l2, h2, &neglow, &neghigh); | |
313 | add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh); | |
314 | } | |
315 | if (h2 < 0) | |
316 | { | |
317 | neg_double (l1, h1, &neglow, &neghigh); | |
318 | add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh); | |
319 | } | |
320 | return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0; | |
6d716ca8 RS |
321 | } |
322 | \f | |
906c4e36 | 323 | /* Shift the doubleword integer in L1, H1 left by COUNT places |
6d716ca8 RS |
324 | keeping only PREC bits of result. |
325 | Shift right if COUNT is negative. | |
326 | ARITH nonzero specifies arithmetic shifting; otherwise use logical shift. | |
fe3e8e40 | 327 | Return nonzero if the arithmetic shift overflows, assuming it's signed. |
906c4e36 | 328 | Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */ |
6d716ca8 | 329 | |
fe3e8e40 | 330 | int |
6d716ca8 | 331 | lshift_double (l1, h1, count, prec, lv, hv, arith) |
906c4e36 RK |
332 | HOST_WIDE_INT l1, h1; |
333 | int count, prec; | |
334 | HOST_WIDE_INT *lv, *hv; | |
6d716ca8 RS |
335 | int arith; |
336 | { | |
906c4e36 | 337 | short arg1[MAX_SHORTS]; |
6d716ca8 | 338 | register int i; |
fe3e8e40 | 339 | register int carry, overflow; |
6d716ca8 RS |
340 | |
341 | if (count < 0) | |
342 | { | |
343 | rshift_double (l1, h1, - count, prec, lv, hv, arith); | |
fe3e8e40 | 344 | return 0; |
6d716ca8 RS |
345 | } |
346 | ||
347 | encode (arg1, l1, h1); | |
348 | ||
349 | if (count > prec) | |
350 | count = prec; | |
351 | ||
fe3e8e40 | 352 | overflow = 0; |
6d716ca8 RS |
353 | while (count > 0) |
354 | { | |
355 | carry = 0; | |
906c4e36 | 356 | for (i = 0; i < MAX_SHORTS; i++) |
6d716ca8 RS |
357 | { |
358 | carry += arg1[i] << 1; | |
359 | arg1[i] = carry & 0xff; | |
360 | carry >>= 8; | |
361 | } | |
362 | count--; | |
fe3e8e40 | 363 | overflow |= carry ^ (arg1[7] >> 7); |
6d716ca8 RS |
364 | } |
365 | ||
366 | decode (arg1, lv, hv); | |
fe3e8e40 | 367 | return overflow; |
6d716ca8 RS |
368 | } |
369 | ||
906c4e36 | 370 | /* Shift the doubleword integer in L1, H1 right by COUNT places |
6d716ca8 RS |
371 | keeping only PREC bits of result. COUNT must be positive. |
372 | ARITH nonzero specifies arithmetic shifting; otherwise use logical shift. | |
906c4e36 | 373 | Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */ |
6d716ca8 RS |
374 | |
375 | void | |
376 | rshift_double (l1, h1, count, prec, lv, hv, arith) | |
906c4e36 RK |
377 | HOST_WIDE_INT l1, h1, count, prec; |
378 | HOST_WIDE_INT *lv, *hv; | |
6d716ca8 RS |
379 | int arith; |
380 | { | |
906c4e36 | 381 | short arg1[MAX_SHORTS]; |
6d716ca8 RS |
382 | register int i; |
383 | register int carry; | |
384 | ||
385 | encode (arg1, l1, h1); | |
386 | ||
387 | if (count > prec) | |
388 | count = prec; | |
389 | ||
390 | while (count > 0) | |
391 | { | |
392 | carry = arith && arg1[7] >> 7; | |
906c4e36 | 393 | for (i = MAX_SHORTS - 1; i >= 0; i--) |
6d716ca8 RS |
394 | { |
395 | carry <<= 8; | |
396 | carry += arg1[i]; | |
397 | arg1[i] = (carry >> 1) & 0xff; | |
398 | } | |
399 | count--; | |
400 | } | |
401 | ||
402 | decode (arg1, lv, hv); | |
403 | } | |
404 | \f | |
906c4e36 | 405 | /* Rotate the doubldword integer in L1, H1 left by COUNT places |
6d716ca8 RS |
406 | keeping only PREC bits of result. |
407 | Rotate right if COUNT is negative. | |
906c4e36 | 408 | Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */ |
6d716ca8 RS |
409 | |
410 | void | |
411 | lrotate_double (l1, h1, count, prec, lv, hv) | |
906c4e36 RK |
412 | HOST_WIDE_INT l1, h1, count, prec; |
413 | HOST_WIDE_INT *lv, *hv; | |
6d716ca8 | 414 | { |
906c4e36 | 415 | short arg1[MAX_SHORTS]; |
6d716ca8 RS |
416 | register int i; |
417 | register int carry; | |
418 | ||
419 | if (count < 0) | |
420 | { | |
421 | rrotate_double (l1, h1, - count, prec, lv, hv); | |
422 | return; | |
423 | } | |
424 | ||
425 | encode (arg1, l1, h1); | |
426 | ||
427 | if (count > prec) | |
428 | count = prec; | |
429 | ||
906c4e36 | 430 | carry = arg1[MAX_SHORTS - 1] >> 7; |
6d716ca8 RS |
431 | while (count > 0) |
432 | { | |
906c4e36 | 433 | for (i = 0; i < MAX_SHORTS; i++) |
6d716ca8 RS |
434 | { |
435 | carry += arg1[i] << 1; | |
436 | arg1[i] = carry & 0xff; | |
437 | carry >>= 8; | |
438 | } | |
439 | count--; | |
440 | } | |
441 | ||
442 | decode (arg1, lv, hv); | |
443 | } | |
444 | ||
906c4e36 | 445 | /* Rotate the doubleword integer in L1, H1 left by COUNT places |
6d716ca8 | 446 | keeping only PREC bits of result. COUNT must be positive. |
906c4e36 | 447 | Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */ |
6d716ca8 RS |
448 | |
449 | void | |
450 | rrotate_double (l1, h1, count, prec, lv, hv) | |
906c4e36 RK |
451 | HOST_WIDE_INT l1, h1, count, prec; |
452 | HOST_WIDE_INT *lv, *hv; | |
6d716ca8 | 453 | { |
906c4e36 | 454 | short arg1[MAX_SHORTS]; |
6d716ca8 RS |
455 | register int i; |
456 | register int carry; | |
457 | ||
458 | encode (arg1, l1, h1); | |
459 | ||
460 | if (count > prec) | |
461 | count = prec; | |
462 | ||
463 | carry = arg1[0] & 1; | |
464 | while (count > 0) | |
465 | { | |
906c4e36 | 466 | for (i = MAX_SHORTS - 1; i >= 0; i--) |
6d716ca8 RS |
467 | { |
468 | carry <<= 8; | |
469 | carry += arg1[i]; | |
470 | arg1[i] = (carry >> 1) & 0xff; | |
471 | } | |
472 | count--; | |
473 | } | |
474 | ||
475 | decode (arg1, lv, hv); | |
476 | } | |
477 | \f | |
906c4e36 | 478 | /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN |
6d716ca8 RS |
479 | for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM). |
480 | CODE is a tree code for a kind of division, one of | |
481 | TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR | |
482 | or EXACT_DIV_EXPR | |
fe3e8e40 RS |
483 | It controls how the quotient is rounded to a integer. |
484 | Return nonzero if the operation overflows. | |
6d716ca8 RS |
485 | UNS nonzero says do unsigned division. */ |
486 | ||
fe3e8e40 | 487 | static int |
6d716ca8 RS |
488 | div_and_round_double (code, uns, |
489 | lnum_orig, hnum_orig, lden_orig, hden_orig, | |
490 | lquo, hquo, lrem, hrem) | |
491 | enum tree_code code; | |
492 | int uns; | |
906c4e36 RK |
493 | HOST_WIDE_INT lnum_orig, hnum_orig; /* num == numerator == dividend */ |
494 | HOST_WIDE_INT lden_orig, hden_orig; /* den == denominator == divisor */ | |
495 | HOST_WIDE_INT *lquo, *hquo, *lrem, *hrem; | |
6d716ca8 RS |
496 | { |
497 | int quo_neg = 0; | |
906c4e36 RK |
498 | short num[MAX_SHORTS + 1]; /* extra element for scaling. */ |
499 | short den[MAX_SHORTS], quo[MAX_SHORTS]; | |
6d716ca8 RS |
500 | register int i, j, work; |
501 | register int carry = 0; | |
b8eb43a2 RK |
502 | unsigned HOST_WIDE_INT lnum = lnum_orig; |
503 | HOST_WIDE_INT hnum = hnum_orig; | |
504 | unsigned HOST_WIDE_INT lden = lden_orig; | |
505 | HOST_WIDE_INT hden = hden_orig; | |
fe3e8e40 | 506 | int overflow = 0; |
6d716ca8 RS |
507 | |
508 | if ((hden == 0) && (lden == 0)) | |
509 | abort (); | |
510 | ||
511 | /* calculate quotient sign and convert operands to unsigned. */ | |
512 | if (!uns) | |
513 | { | |
fe3e8e40 | 514 | if (hnum < 0) |
6d716ca8 RS |
515 | { |
516 | quo_neg = ~ quo_neg; | |
fe3e8e40 RS |
517 | /* (minimum integer) / (-1) is the only overflow case. */ |
518 | if (neg_double (lnum, hnum, &lnum, &hnum) && (lden & hden) == -1) | |
519 | overflow = 1; | |
6d716ca8 | 520 | } |
fe3e8e40 | 521 | if (hden < 0) |
6d716ca8 RS |
522 | { |
523 | quo_neg = ~ quo_neg; | |
fe3e8e40 | 524 | neg_double (lden, hden, &lden, &hden); |
6d716ca8 RS |
525 | } |
526 | } | |
527 | ||
528 | if (hnum == 0 && hden == 0) | |
529 | { /* single precision */ | |
530 | *hquo = *hrem = 0; | |
531 | *lquo = lnum / lden; /* rounds toward zero since positive args */ | |
532 | goto finish_up; | |
533 | } | |
534 | ||
535 | if (hnum == 0) | |
536 | { /* trivial case: dividend < divisor */ | |
537 | /* hden != 0 already checked. */ | |
538 | *hquo = *lquo = 0; | |
539 | *hrem = hnum; | |
540 | *lrem = lnum; | |
541 | goto finish_up; | |
542 | } | |
543 | ||
544 | bzero (quo, sizeof quo); | |
545 | ||
546 | bzero (num, sizeof num); /* to zero 9th element */ | |
547 | bzero (den, sizeof den); | |
548 | ||
549 | encode (num, lnum, hnum); | |
550 | encode (den, lden, hden); | |
551 | ||
552 | /* This code requires more than just hden == 0. | |
553 | We also have to require that we don't need more than three bytes | |
554 | to hold CARRY. If we ever did need four bytes to hold it, we | |
555 | would lose part of it when computing WORK on the next round. */ | |
556 | if (hden == 0 && ((lden << 8) >> 8) == lden) | |
557 | { /* simpler algorithm */ | |
558 | /* hnum != 0 already checked. */ | |
906c4e36 | 559 | for (i = MAX_SHORTS - 1; i >= 0; i--) |
6d716ca8 RS |
560 | { |
561 | work = num[i] + (carry << 8); | |
562 | quo[i] = work / lden; | |
563 | carry = work % lden; | |
564 | } | |
565 | } | |
566 | else { /* full double precision, | |
567 | with thanks to Don Knuth's | |
6dc42e49 | 568 | "Seminumerical Algorithms". */ |
6d716ca8 RS |
569 | #define BASE 256 |
570 | int quo_est, scale, num_hi_sig, den_hi_sig, quo_hi_sig; | |
571 | ||
572 | /* Find the highest non-zero divisor digit. */ | |
906c4e36 | 573 | for (i = MAX_SHORTS - 1; ; i--) |
6d716ca8 RS |
574 | if (den[i] != 0) { |
575 | den_hi_sig = i; | |
576 | break; | |
577 | } | |
906c4e36 | 578 | for (i = MAX_SHORTS - 1; ; i--) |
6d716ca8 RS |
579 | if (num[i] != 0) { |
580 | num_hi_sig = i; | |
581 | break; | |
582 | } | |
583 | quo_hi_sig = num_hi_sig - den_hi_sig + 1; | |
584 | ||
585 | /* Insure that the first digit of the divisor is at least BASE/2. | |
586 | This is required by the quotient digit estimation algorithm. */ | |
587 | ||
588 | scale = BASE / (den[den_hi_sig] + 1); | |
589 | if (scale > 1) { /* scale divisor and dividend */ | |
590 | carry = 0; | |
906c4e36 | 591 | for (i = 0; i <= MAX_SHORTS - 1; i++) { |
6d716ca8 RS |
592 | work = (num[i] * scale) + carry; |
593 | num[i] = work & 0xff; | |
594 | carry = work >> 8; | |
595 | if (num[i] != 0) num_hi_sig = i; | |
596 | } | |
597 | carry = 0; | |
906c4e36 | 598 | for (i = 0; i <= MAX_SHORTS - 1; i++) { |
6d716ca8 RS |
599 | work = (den[i] * scale) + carry; |
600 | den[i] = work & 0xff; | |
601 | carry = work >> 8; | |
602 | if (den[i] != 0) den_hi_sig = i; | |
603 | } | |
604 | } | |
605 | ||
606 | /* Main loop */ | |
607 | for (i = quo_hi_sig; i > 0; i--) { | |
6dc42e49 | 608 | /* guess the next quotient digit, quo_est, by dividing the first |
6d716ca8 RS |
609 | two remaining dividend digits by the high order quotient digit. |
610 | quo_est is never low and is at most 2 high. */ | |
611 | ||
612 | int num_hi; /* index of highest remaining dividend digit */ | |
613 | ||
614 | num_hi = i + den_hi_sig; | |
615 | ||
616 | work = (num[num_hi] * BASE) + (num_hi > 0 ? num[num_hi - 1] : 0); | |
617 | if (num[num_hi] != den[den_hi_sig]) { | |
618 | quo_est = work / den[den_hi_sig]; | |
619 | } | |
620 | else { | |
621 | quo_est = BASE - 1; | |
622 | } | |
623 | ||
624 | /* refine quo_est so it's usually correct, and at most one high. */ | |
625 | while ((den[den_hi_sig - 1] * quo_est) | |
626 | > (((work - (quo_est * den[den_hi_sig])) * BASE) | |
627 | + ((num_hi - 1) > 0 ? num[num_hi - 2] : 0))) | |
628 | quo_est--; | |
629 | ||
630 | /* Try QUO_EST as the quotient digit, by multiplying the | |
631 | divisor by QUO_EST and subtracting from the remaining dividend. | |
632 | Keep in mind that QUO_EST is the I - 1st digit. */ | |
633 | ||
634 | carry = 0; | |
635 | ||
636 | for (j = 0; j <= den_hi_sig; j++) | |
637 | { | |
638 | int digit; | |
639 | ||
640 | work = num[i + j - 1] - (quo_est * den[j]) + carry; | |
641 | digit = work & 0xff; | |
642 | carry = work >> 8; | |
643 | if (digit < 0) | |
644 | { | |
645 | digit += BASE; | |
646 | carry--; | |
647 | } | |
648 | num[i + j - 1] = digit; | |
649 | } | |
650 | ||
651 | /* if quo_est was high by one, then num[i] went negative and | |
652 | we need to correct things. */ | |
653 | ||
654 | if (num[num_hi] < 0) | |
655 | { | |
656 | quo_est--; | |
657 | carry = 0; /* add divisor back in */ | |
658 | for (j = 0; j <= den_hi_sig; j++) | |
659 | { | |
660 | work = num[i + j - 1] + den[j] + carry; | |
661 | if (work > BASE) | |
662 | { | |
663 | work -= BASE; | |
664 | carry = 1; | |
665 | } | |
666 | else | |
667 | { | |
668 | carry = 0; | |
669 | } | |
670 | num[i + j - 1] = work; | |
671 | } | |
672 | num [num_hi] += carry; | |
673 | } | |
674 | ||
675 | /* store the quotient digit. */ | |
676 | quo[i - 1] = quo_est; | |
677 | } | |
678 | } | |
679 | ||
680 | decode (quo, lquo, hquo); | |
681 | ||
682 | finish_up: | |
683 | /* if result is negative, make it so. */ | |
684 | if (quo_neg) | |
685 | neg_double (*lquo, *hquo, lquo, hquo); | |
686 | ||
687 | /* compute trial remainder: rem = num - (quo * den) */ | |
688 | mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem); | |
689 | neg_double (*lrem, *hrem, lrem, hrem); | |
690 | add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem); | |
691 | ||
692 | switch (code) | |
693 | { | |
694 | case TRUNC_DIV_EXPR: | |
695 | case TRUNC_MOD_EXPR: /* round toward zero */ | |
696 | case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */ | |
fe3e8e40 | 697 | return overflow; |
6d716ca8 RS |
698 | |
699 | case FLOOR_DIV_EXPR: | |
700 | case FLOOR_MOD_EXPR: /* round toward negative infinity */ | |
701 | if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */ | |
702 | { | |
703 | /* quo = quo - 1; */ | |
906c4e36 RK |
704 | add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, |
705 | lquo, hquo); | |
6d716ca8 | 706 | } |
fe3e8e40 | 707 | else return overflow; |
6d716ca8 RS |
708 | break; |
709 | ||
710 | case CEIL_DIV_EXPR: | |
711 | case CEIL_MOD_EXPR: /* round toward positive infinity */ | |
712 | if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */ | |
713 | { | |
906c4e36 RK |
714 | add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0, |
715 | lquo, hquo); | |
6d716ca8 | 716 | } |
fe3e8e40 | 717 | else return overflow; |
6d716ca8 RS |
718 | break; |
719 | ||
720 | case ROUND_DIV_EXPR: | |
721 | case ROUND_MOD_EXPR: /* round to closest integer */ | |
722 | { | |
906c4e36 RK |
723 | HOST_WIDE_INT labs_rem = *lrem, habs_rem = *hrem; |
724 | HOST_WIDE_INT labs_den = lden, habs_den = hden, ltwice, htwice; | |
6d716ca8 RS |
725 | |
726 | /* get absolute values */ | |
727 | if (*hrem < 0) neg_double (*lrem, *hrem, &labs_rem, &habs_rem); | |
728 | if (hden < 0) neg_double (lden, hden, &labs_den, &habs_den); | |
729 | ||
730 | /* if (2 * abs (lrem) >= abs (lden)) */ | |
906c4e36 RK |
731 | mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0, |
732 | labs_rem, habs_rem, <wice, &htwice); | |
733 | if (((unsigned HOST_WIDE_INT) habs_den | |
734 | < (unsigned HOST_WIDE_INT) htwice) | |
735 | || (((unsigned HOST_WIDE_INT) habs_den | |
736 | == (unsigned HOST_WIDE_INT) htwice) | |
737 | && ((HOST_WIDE_INT unsigned) labs_den | |
738 | < (unsigned HOST_WIDE_INT) ltwice))) | |
6d716ca8 RS |
739 | { |
740 | if (*hquo < 0) | |
741 | /* quo = quo - 1; */ | |
906c4e36 RK |
742 | add_double (*lquo, *hquo, |
743 | (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo); | |
6d716ca8 RS |
744 | else |
745 | /* quo = quo + 1; */ | |
906c4e36 RK |
746 | add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0, |
747 | lquo, hquo); | |
6d716ca8 | 748 | } |
fe3e8e40 | 749 | else return overflow; |
6d716ca8 RS |
750 | } |
751 | break; | |
752 | ||
753 | default: | |
754 | abort (); | |
755 | } | |
756 | ||
757 | /* compute true remainder: rem = num - (quo * den) */ | |
758 | mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem); | |
759 | neg_double (*lrem, *hrem, lrem, hrem); | |
760 | add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem); | |
fe3e8e40 | 761 | return overflow; |
6d716ca8 RS |
762 | } |
763 | \f | |
5352b11a RS |
764 | /* Effectively truncate a real value to represent |
765 | the nearest possible value in a narrower mode. | |
766 | The result is actually represented in the same data type as the argument, | |
767 | but its value is usually different. */ | |
768 | ||
769 | REAL_VALUE_TYPE | |
770 | real_value_truncate (mode, arg) | |
771 | enum machine_mode mode; | |
772 | REAL_VALUE_TYPE arg; | |
773 | { | |
774 | #ifdef __STDC__ | |
775 | /* Make sure the value is actually stored in memory before we turn off | |
776 | the handler. */ | |
777 | volatile | |
778 | #endif | |
779 | REAL_VALUE_TYPE value; | |
780 | jmp_buf handler; | |
781 | ||
782 | if (setjmp (handler)) | |
783 | { | |
784 | error ("floating overflow"); | |
785 | return dconst0; | |
786 | } | |
787 | set_float_handler (handler); | |
788 | value = REAL_VALUE_TRUNCATE (mode, arg); | |
906c4e36 | 789 | set_float_handler (NULL_PTR); |
5352b11a RS |
790 | return value; |
791 | } | |
792 | ||
6d716ca8 RS |
793 | #if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT |
794 | ||
795 | /* Check for infinity in an IEEE double precision number. */ | |
796 | ||
797 | int | |
798 | target_isinf (x) | |
799 | REAL_VALUE_TYPE x; | |
800 | { | |
801 | /* The IEEE 64-bit double format. */ | |
802 | union { | |
803 | REAL_VALUE_TYPE d; | |
804 | struct { | |
805 | unsigned sign : 1; | |
806 | unsigned exponent : 11; | |
807 | unsigned mantissa1 : 20; | |
808 | unsigned mantissa2; | |
809 | } little_endian; | |
810 | struct { | |
811 | unsigned mantissa2; | |
812 | unsigned mantissa1 : 20; | |
813 | unsigned exponent : 11; | |
814 | unsigned sign : 1; | |
815 | } big_endian; | |
816 | } u; | |
817 | ||
818 | u.d = dconstm1; | |
819 | if (u.big_endian.sign == 1) | |
820 | { | |
821 | u.d = x; | |
822 | return (u.big_endian.exponent == 2047 | |
823 | && u.big_endian.mantissa1 == 0 | |
824 | && u.big_endian.mantissa2 == 0); | |
825 | } | |
826 | else | |
827 | { | |
828 | u.d = x; | |
829 | return (u.little_endian.exponent == 2047 | |
830 | && u.little_endian.mantissa1 == 0 | |
831 | && u.little_endian.mantissa2 == 0); | |
832 | } | |
833 | } | |
834 | ||
7d4d4d22 RS |
835 | /* Check whether an IEEE double precision number is a NaN. */ |
836 | ||
837 | int | |
838 | target_isnan (x) | |
839 | REAL_VALUE_TYPE x; | |
840 | { | |
841 | /* The IEEE 64-bit double format. */ | |
842 | union { | |
843 | REAL_VALUE_TYPE d; | |
844 | struct { | |
845 | unsigned sign : 1; | |
846 | unsigned exponent : 11; | |
847 | unsigned mantissa1 : 20; | |
848 | unsigned mantissa2; | |
849 | } little_endian; | |
850 | struct { | |
851 | unsigned mantissa2; | |
852 | unsigned mantissa1 : 20; | |
853 | unsigned exponent : 11; | |
854 | unsigned sign : 1; | |
855 | } big_endian; | |
856 | } u; | |
857 | ||
858 | u.d = dconstm1; | |
859 | if (u.big_endian.sign == 1) | |
860 | { | |
861 | u.d = x; | |
862 | return (u.big_endian.exponent == 2047 | |
863 | && (u.big_endian.mantissa1 != 0 | |
864 | || u.big_endian.mantissa2 != 0)); | |
865 | } | |
866 | else | |
867 | { | |
868 | u.d = x; | |
869 | return (u.little_endian.exponent == 2047 | |
870 | && (u.little_endian.mantissa1 != 0 | |
871 | || u.little_endian.mantissa2 != 0)); | |
872 | } | |
873 | } | |
874 | ||
c05a9b68 | 875 | /* Check for a negative IEEE double precision number. */ |
6d716ca8 RS |
876 | |
877 | int | |
c05a9b68 | 878 | target_negative (x) |
6d716ca8 RS |
879 | REAL_VALUE_TYPE x; |
880 | { | |
c05a9b68 RS |
881 | /* The IEEE 64-bit double format. */ |
882 | union { | |
883 | REAL_VALUE_TYPE d; | |
884 | struct { | |
885 | unsigned sign : 1; | |
886 | unsigned exponent : 11; | |
887 | unsigned mantissa1 : 20; | |
888 | unsigned mantissa2; | |
889 | } little_endian; | |
890 | struct { | |
891 | unsigned mantissa2; | |
892 | unsigned mantissa1 : 20; | |
893 | unsigned exponent : 11; | |
894 | unsigned sign : 1; | |
895 | } big_endian; | |
896 | } u; | |
6d716ca8 | 897 | |
c05a9b68 RS |
898 | u.d = dconstm1; |
899 | if (u.big_endian.sign == 1) | |
900 | { | |
901 | u.d = x; | |
902 | return u.big_endian.sign; | |
903 | } | |
904 | else | |
905 | { | |
906 | u.d = x; | |
907 | return u.little_endian.sign; | |
908 | } | |
6d716ca8 RS |
909 | } |
910 | #else /* Target not IEEE */ | |
911 | ||
912 | /* Let's assume other float formats don't have infinity. | |
913 | (This can be overridden by redefining REAL_VALUE_ISINF.) */ | |
914 | ||
915 | target_isinf (x) | |
916 | REAL_VALUE_TYPE x; | |
917 | { | |
918 | return 0; | |
919 | } | |
920 | ||
7d4d4d22 RS |
921 | /* Let's assume other float formats don't have NaNs. |
922 | (This can be overridden by redefining REAL_VALUE_ISNAN.) */ | |
923 | ||
924 | target_isnan (x) | |
925 | REAL_VALUE_TYPE x; | |
926 | { | |
927 | return 0; | |
928 | } | |
929 | ||
6d716ca8 | 930 | /* Let's assume other float formats don't have minus zero. |
c05a9b68 | 931 | (This can be overridden by redefining REAL_VALUE_NEGATIVE.) */ |
6d716ca8 | 932 | |
c05a9b68 | 933 | target_negative (x) |
6d716ca8 RS |
934 | REAL_VALUE_TYPE x; |
935 | { | |
c05a9b68 | 936 | return x < 0; |
6d716ca8 RS |
937 | } |
938 | #endif /* Target not IEEE */ | |
939 | \f | |
940 | /* Split a tree IN into a constant and a variable part | |
941 | that could be combined with CODE to make IN. | |
942 | CODE must be a commutative arithmetic operation. | |
943 | Store the constant part into *CONP and the variable in &VARP. | |
944 | Return 1 if this was done; zero means the tree IN did not decompose | |
945 | this way. | |
946 | ||
947 | If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. | |
948 | Therefore, we must tell the caller whether the variable part | |
949 | was subtracted. We do this by storing 1 or -1 into *VARSIGNP. | |
950 | The value stored is the coefficient for the variable term. | |
951 | The constant term we return should always be added; | |
952 | we negate it if necessary. */ | |
953 | ||
954 | static int | |
955 | split_tree (in, code, varp, conp, varsignp) | |
956 | tree in; | |
957 | enum tree_code code; | |
958 | tree *varp, *conp; | |
959 | int *varsignp; | |
960 | { | |
961 | register tree outtype = TREE_TYPE (in); | |
962 | *varp = 0; | |
963 | *conp = 0; | |
964 | ||
965 | /* Strip any conversions that don't change the machine mode. */ | |
966 | while ((TREE_CODE (in) == NOP_EXPR | |
967 | || TREE_CODE (in) == CONVERT_EXPR) | |
968 | && (TYPE_MODE (TREE_TYPE (in)) | |
969 | == TYPE_MODE (TREE_TYPE (TREE_OPERAND (in, 0))))) | |
970 | in = TREE_OPERAND (in, 0); | |
971 | ||
972 | if (TREE_CODE (in) == code | |
973 | || (TREE_CODE (TREE_TYPE (in)) != REAL_TYPE | |
974 | /* We can associate addition and subtraction together | |
975 | (even though the C standard doesn't say so) | |
976 | for integers because the value is not affected. | |
977 | For reals, the value might be affected, so we can't. */ | |
978 | && | |
979 | ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR) | |
980 | || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR)))) | |
981 | { | |
982 | enum tree_code code = TREE_CODE (TREE_OPERAND (in, 0)); | |
983 | if (code == INTEGER_CST) | |
984 | { | |
985 | *conp = TREE_OPERAND (in, 0); | |
986 | *varp = TREE_OPERAND (in, 1); | |
987 | if (TYPE_MODE (TREE_TYPE (*varp)) != TYPE_MODE (outtype) | |
988 | && TREE_TYPE (*varp) != outtype) | |
989 | *varp = convert (outtype, *varp); | |
990 | *varsignp = (TREE_CODE (in) == MINUS_EXPR) ? -1 : 1; | |
991 | return 1; | |
992 | } | |
993 | if (TREE_CONSTANT (TREE_OPERAND (in, 1))) | |
994 | { | |
995 | *conp = TREE_OPERAND (in, 1); | |
996 | *varp = TREE_OPERAND (in, 0); | |
997 | *varsignp = 1; | |
998 | if (TYPE_MODE (TREE_TYPE (*varp)) != TYPE_MODE (outtype) | |
999 | && TREE_TYPE (*varp) != outtype) | |
1000 | *varp = convert (outtype, *varp); | |
1001 | if (TREE_CODE (in) == MINUS_EXPR) | |
1002 | { | |
1003 | /* If operation is subtraction and constant is second, | |
1004 | must negate it to get an additive constant. | |
1005 | And this cannot be done unless it is a manifest constant. | |
1006 | It could also be the address of a static variable. | |
1007 | We cannot negate that, so give up. */ | |
1008 | if (TREE_CODE (*conp) == INTEGER_CST) | |
1009 | /* Subtracting from integer_zero_node loses for long long. */ | |
1010 | *conp = fold (build1 (NEGATE_EXPR, TREE_TYPE (*conp), *conp)); | |
1011 | else | |
1012 | return 0; | |
1013 | } | |
1014 | return 1; | |
1015 | } | |
1016 | if (TREE_CONSTANT (TREE_OPERAND (in, 0))) | |
1017 | { | |
1018 | *conp = TREE_OPERAND (in, 0); | |
1019 | *varp = TREE_OPERAND (in, 1); | |
1020 | if (TYPE_MODE (TREE_TYPE (*varp)) != TYPE_MODE (outtype) | |
1021 | && TREE_TYPE (*varp) != outtype) | |
1022 | *varp = convert (outtype, *varp); | |
1023 | *varsignp = (TREE_CODE (in) == MINUS_EXPR) ? -1 : 1; | |
1024 | return 1; | |
1025 | } | |
1026 | } | |
1027 | return 0; | |
1028 | } | |
1029 | \f | |
1030 | /* Combine two constants NUM and ARG2 under operation CODE | |
1031 | to produce a new constant. | |
1032 | We assume ARG1 and ARG2 have the same data type, | |
1033 | or at least are the same kind of constant and the same machine mode. */ | |
1034 | ||
6d716ca8 RS |
1035 | static tree |
1036 | const_binop (code, arg1, arg2) | |
1037 | enum tree_code code; | |
1038 | register tree arg1, arg2; | |
1039 | { | |
1040 | if (TREE_CODE (arg1) == INTEGER_CST) | |
1041 | { | |
906c4e36 RK |
1042 | register HOST_WIDE_INT int1l = TREE_INT_CST_LOW (arg1); |
1043 | register HOST_WIDE_INT int1h = TREE_INT_CST_HIGH (arg1); | |
1044 | HOST_WIDE_INT int2l = TREE_INT_CST_LOW (arg2); | |
1045 | HOST_WIDE_INT int2h = TREE_INT_CST_HIGH (arg2); | |
1046 | HOST_WIDE_INT low, hi; | |
1047 | HOST_WIDE_INT garbagel, garbageh; | |
6d716ca8 RS |
1048 | register tree t; |
1049 | int uns = TREE_UNSIGNED (TREE_TYPE (arg1)); | |
fe3e8e40 RS |
1050 | /* Propagate overflow flags from operands; also record new overflow. */ |
1051 | int overflow | |
1052 | = TREE_CONSTANT_OVERFLOW (arg0) | TREE_CONSTANT_OVERFLOW (arg1); | |
6d716ca8 RS |
1053 | |
1054 | switch (code) | |
1055 | { | |
1056 | case BIT_IOR_EXPR: | |
1057 | t = build_int_2 (int1l | int2l, int1h | int2h); | |
1058 | break; | |
1059 | ||
1060 | case BIT_XOR_EXPR: | |
1061 | t = build_int_2 (int1l ^ int2l, int1h ^ int2h); | |
1062 | break; | |
1063 | ||
1064 | case BIT_AND_EXPR: | |
1065 | t = build_int_2 (int1l & int2l, int1h & int2h); | |
1066 | break; | |
1067 | ||
1068 | case BIT_ANDTC_EXPR: | |
1069 | t = build_int_2 (int1l & ~int2l, int1h & ~int2h); | |
1070 | break; | |
1071 | ||
1072 | case RSHIFT_EXPR: | |
1073 | int2l = - int2l; | |
1074 | case LSHIFT_EXPR: | |
fe3e8e40 RS |
1075 | overflow = lshift_double (int1l, int1h, int2l, |
1076 | TYPE_PRECISION (TREE_TYPE (arg1)), | |
1077 | &low, &hi, | |
1078 | !uns); | |
6d716ca8 RS |
1079 | t = build_int_2 (low, hi); |
1080 | break; | |
1081 | ||
1082 | case RROTATE_EXPR: | |
1083 | int2l = - int2l; | |
1084 | case LROTATE_EXPR: | |
1085 | lrotate_double (int1l, int1h, int2l, | |
1086 | TYPE_PRECISION (TREE_TYPE (arg1)), | |
1087 | &low, &hi); | |
1088 | t = build_int_2 (low, hi); | |
1089 | break; | |
1090 | ||
1091 | case PLUS_EXPR: | |
1092 | if (int1h == 0) | |
1093 | { | |
1094 | int2l += int1l; | |
906c4e36 | 1095 | if ((unsigned HOST_WIDE_INT) int2l < int1l) |
fe3e8e40 RS |
1096 | { |
1097 | hi = int2h++; | |
1098 | overflow = ! same_sign (hi, int2h); | |
1099 | } | |
6d716ca8 RS |
1100 | t = build_int_2 (int2l, int2h); |
1101 | break; | |
1102 | } | |
1103 | if (int2h == 0) | |
1104 | { | |
1105 | int1l += int2l; | |
906c4e36 | 1106 | if ((unsigned HOST_WIDE_INT) int1l < int2l) |
fe3e8e40 RS |
1107 | { |
1108 | hi = int1h++; | |
1109 | overflow = ! same_sign (hi, int1h); | |
1110 | } | |
6d716ca8 RS |
1111 | t = build_int_2 (int1l, int1h); |
1112 | break; | |
1113 | } | |
fe3e8e40 | 1114 | overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi); |
6d716ca8 RS |
1115 | t = build_int_2 (low, hi); |
1116 | break; | |
1117 | ||
1118 | case MINUS_EXPR: | |
1119 | if (int2h == 0 && int2l == 0) | |
1120 | { | |
1121 | t = build_int_2 (int1l, int1h); | |
1122 | break; | |
1123 | } | |
fe3e8e40 RS |
1124 | neg_double (int2l, int2h, &low, &hi); |
1125 | add_double (int1l, int1h, low, hi, &low, &hi); | |
1126 | overflow = overflow_sum_sign (hi, int2h, int1h); | |
6d716ca8 RS |
1127 | t = build_int_2 (low, hi); |
1128 | break; | |
1129 | ||
1130 | case MULT_EXPR: | |
812dd8a3 | 1131 | /* Optimize simple cases. */ |
6d716ca8 RS |
1132 | if (int1h == 0) |
1133 | { | |
906c4e36 | 1134 | unsigned HOST_WIDE_INT temp; |
6d716ca8 RS |
1135 | |
1136 | switch (int1l) | |
1137 | { | |
1138 | case 0: | |
1139 | t = build_int_2 (0, 0); | |
1140 | goto got_it; | |
1141 | case 1: | |
1142 | t = build_int_2 (int2l, int2h); | |
1143 | goto got_it; | |
1144 | case 2: | |
fe3e8e40 | 1145 | overflow = left_shift_overflows (int2h, 1); |
6d716ca8 | 1146 | temp = int2l + int2l; |
fe3e8e40 | 1147 | int2h = (int2h << 1) + (temp < int2l); |
6d716ca8 RS |
1148 | t = build_int_2 (temp, int2h); |
1149 | goto got_it; | |
812dd8a3 | 1150 | #if 0 /* This code can lose carries. */ |
6d716ca8 RS |
1151 | case 3: |
1152 | temp = int2l + int2l + int2l; | |
1153 | int2h = int2h * 3 + (temp < int2l); | |
1154 | t = build_int_2 (temp, int2h); | |
1155 | goto got_it; | |
812dd8a3 | 1156 | #endif |
6d716ca8 | 1157 | case 4: |
fe3e8e40 | 1158 | overflow = left_shift_overflows (int2h, 2); |
6d716ca8 | 1159 | temp = int2l + int2l; |
fe3e8e40 | 1160 | int2h = (int2h << 2) + ((temp < int2l) << 1); |
6d716ca8 RS |
1161 | int2l = temp; |
1162 | temp += temp; | |
1163 | int2h += (temp < int2l); | |
1164 | t = build_int_2 (temp, int2h); | |
1165 | goto got_it; | |
1166 | case 8: | |
fe3e8e40 | 1167 | overflow = left_shift_overflows (int2h, 3); |
6d716ca8 | 1168 | temp = int2l + int2l; |
fe3e8e40 | 1169 | int2h = (int2h << 3) + ((temp < int2l) << 2); |
6d716ca8 RS |
1170 | int2l = temp; |
1171 | temp += temp; | |
1172 | int2h += (temp < int2l) << 1; | |
1173 | int2l = temp; | |
1174 | temp += temp; | |
1175 | int2h += (temp < int2l); | |
1176 | t = build_int_2 (temp, int2h); | |
1177 | goto got_it; | |
1178 | default: | |
1179 | break; | |
1180 | } | |
1181 | } | |
1182 | ||
1183 | if (int2h == 0) | |
1184 | { | |
1185 | if (int2l == 0) | |
1186 | { | |
1187 | t = build_int_2 (0, 0); | |
1188 | break; | |
1189 | } | |
1190 | if (int2l == 1) | |
1191 | { | |
1192 | t = build_int_2 (int1l, int1h); | |
1193 | break; | |
1194 | } | |
1195 | } | |
1196 | ||
fe3e8e40 | 1197 | overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi); |
6d716ca8 RS |
1198 | t = build_int_2 (low, hi); |
1199 | break; | |
1200 | ||
1201 | case TRUNC_DIV_EXPR: | |
1202 | case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR: | |
1203 | case EXACT_DIV_EXPR: | |
1204 | /* This is a shortcut for a common special case. | |
1205 | It reduces the number of tree nodes generated | |
1206 | and saves time. */ | |
1207 | if (int2h == 0 && int2l > 0 | |
1208 | && TREE_TYPE (arg1) == sizetype | |
1209 | && int1h == 0 && int1l >= 0) | |
1210 | { | |
1211 | if (code == CEIL_DIV_EXPR) | |
1212 | int1l += int2l-1; | |
1213 | return size_int (int1l / int2l); | |
1214 | } | |
1215 | case ROUND_DIV_EXPR: | |
1216 | if (int2h == 0 && int2l == 1) | |
1217 | { | |
1218 | t = build_int_2 (int1l, int1h); | |
1219 | break; | |
1220 | } | |
1221 | if (int1l == int2l && int1h == int2h) | |
1222 | { | |
1223 | if ((int1l | int1h) == 0) | |
1224 | abort (); | |
1225 | t = build_int_2 (1, 0); | |
1226 | break; | |
1227 | } | |
fe3e8e40 RS |
1228 | overflow = div_and_round_double (code, uns, |
1229 | int1l, int1h, int2l, int2h, | |
1230 | &low, &hi, &garbagel, &garbageh); | |
6d716ca8 RS |
1231 | t = build_int_2 (low, hi); |
1232 | break; | |
1233 | ||
1234 | case TRUNC_MOD_EXPR: case ROUND_MOD_EXPR: | |
1235 | case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR: | |
fe3e8e40 RS |
1236 | overflow = div_and_round_double (code, uns, |
1237 | int1l, int1h, int2l, int2h, | |
1238 | &garbagel, &garbageh, &low, &hi); | |
6d716ca8 RS |
1239 | t = build_int_2 (low, hi); |
1240 | break; | |
1241 | ||
1242 | case MIN_EXPR: | |
1243 | case MAX_EXPR: | |
1244 | if (uns) | |
1245 | { | |
906c4e36 RK |
1246 | low = (((unsigned HOST_WIDE_INT) int1h |
1247 | < (unsigned HOST_WIDE_INT) int2h) | |
1248 | || (((unsigned HOST_WIDE_INT) int1h | |
1249 | == (unsigned HOST_WIDE_INT) int2h) | |
1250 | && ((unsigned HOST_WIDE_INT) int1l | |
1251 | < (unsigned HOST_WIDE_INT) int2l))); | |
6d716ca8 RS |
1252 | } |
1253 | else | |
1254 | { | |
1255 | low = ((int1h < int2h) | |
1256 | || ((int1h == int2h) | |
906c4e36 RK |
1257 | && ((unsigned HOST_WIDE_INT) int1l |
1258 | < (unsigned HOST_WIDE_INT) int2l))); | |
6d716ca8 RS |
1259 | } |
1260 | if (low == (code == MIN_EXPR)) | |
1261 | t = build_int_2 (int1l, int1h); | |
1262 | else | |
1263 | t = build_int_2 (int2l, int2h); | |
1264 | break; | |
1265 | ||
1266 | default: | |
1267 | abort (); | |
1268 | } | |
1269 | got_it: | |
1270 | TREE_TYPE (t) = TREE_TYPE (arg1); | |
1271 | force_fit_type (t); | |
fe3e8e40 | 1272 | TREE_CONSTANT_OVERFLOW (t) = overflow; |
6d716ca8 RS |
1273 | return t; |
1274 | } | |
1275 | #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) | |
1276 | if (TREE_CODE (arg1) == REAL_CST) | |
1277 | { | |
1278 | register REAL_VALUE_TYPE d1; | |
1279 | register REAL_VALUE_TYPE d2; | |
1280 | register REAL_VALUE_TYPE value; | |
7c7b029d | 1281 | tree t; |
6d716ca8 RS |
1282 | |
1283 | d1 = TREE_REAL_CST (arg1); | |
1284 | d2 = TREE_REAL_CST (arg2); | |
7c7b029d | 1285 | if (setjmp (float_error)) |
6d716ca8 | 1286 | { |
fe3e8e40 | 1287 | pedwarn ("floating overflow in constant expression"); |
6d716ca8 RS |
1288 | return build (code, TREE_TYPE (arg1), arg1, arg2); |
1289 | } | |
7c7b029d | 1290 | set_float_handler (float_error); |
6d716ca8 RS |
1291 | |
1292 | #ifdef REAL_ARITHMETIC | |
1293 | REAL_ARITHMETIC (value, code, d1, d2); | |
1294 | #else | |
1295 | switch (code) | |
1296 | { | |
1297 | case PLUS_EXPR: | |
1298 | value = d1 + d2; | |
1299 | break; | |
1300 | ||
1301 | case MINUS_EXPR: | |
1302 | value = d1 - d2; | |
1303 | break; | |
1304 | ||
1305 | case MULT_EXPR: | |
1306 | value = d1 * d2; | |
1307 | break; | |
1308 | ||
1309 | case RDIV_EXPR: | |
1310 | #ifndef REAL_INFINITY | |
1311 | if (d2 == 0) | |
1312 | abort (); | |
1313 | #endif | |
1314 | ||
1315 | value = d1 / d2; | |
1316 | break; | |
1317 | ||
1318 | case MIN_EXPR: | |
1319 | value = MIN (d1, d2); | |
1320 | break; | |
1321 | ||
1322 | case MAX_EXPR: | |
1323 | value = MAX (d1, d2); | |
1324 | break; | |
1325 | ||
1326 | default: | |
1327 | abort (); | |
1328 | } | |
1329 | #endif /* no REAL_ARITHMETIC */ | |
7c7b029d | 1330 | t = build_real (TREE_TYPE (arg1), |
5352b11a | 1331 | real_value_truncate (TYPE_MODE (TREE_TYPE (arg1)), value)); |
906c4e36 | 1332 | set_float_handler (NULL_PTR); |
7c7b029d | 1333 | return t; |
6d716ca8 RS |
1334 | } |
1335 | #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */ | |
1336 | if (TREE_CODE (arg1) == COMPLEX_CST) | |
1337 | { | |
1338 | register tree r1 = TREE_REALPART (arg1); | |
1339 | register tree i1 = TREE_IMAGPART (arg1); | |
1340 | register tree r2 = TREE_REALPART (arg2); | |
1341 | register tree i2 = TREE_IMAGPART (arg2); | |
1342 | register tree t; | |
1343 | ||
1344 | switch (code) | |
1345 | { | |
1346 | case PLUS_EXPR: | |
1347 | t = build_complex (const_binop (PLUS_EXPR, r1, r2), | |
1348 | const_binop (PLUS_EXPR, i1, i2)); | |
1349 | break; | |
1350 | ||
1351 | case MINUS_EXPR: | |
1352 | t = build_complex (const_binop (MINUS_EXPR, r1, r2), | |
1353 | const_binop (MINUS_EXPR, i1, i2)); | |
1354 | break; | |
1355 | ||
1356 | case MULT_EXPR: | |
1357 | t = build_complex (const_binop (MINUS_EXPR, | |
1358 | const_binop (MULT_EXPR, r1, r2), | |
1359 | const_binop (MULT_EXPR, i1, i2)), | |
1360 | const_binop (PLUS_EXPR, | |
1361 | const_binop (MULT_EXPR, r1, i2), | |
1362 | const_binop (MULT_EXPR, i1, r2))); | |
1363 | break; | |
1364 | ||
1365 | case RDIV_EXPR: | |
1366 | { | |
1367 | register tree magsquared | |
1368 | = const_binop (PLUS_EXPR, | |
1369 | const_binop (MULT_EXPR, r2, r2), | |
1370 | const_binop (MULT_EXPR, i2, i2)); | |
1371 | t = build_complex (const_binop (RDIV_EXPR, | |
1372 | const_binop (PLUS_EXPR, | |
1373 | const_binop (MULT_EXPR, r1, r2), | |
1374 | const_binop (MULT_EXPR, i1, i2)), | |
1375 | magsquared), | |
1376 | const_binop (RDIV_EXPR, | |
1377 | const_binop (MINUS_EXPR, | |
1378 | const_binop (MULT_EXPR, i1, r2), | |
1379 | const_binop (MULT_EXPR, r1, i2)), | |
1380 | magsquared)); | |
1381 | } | |
1382 | break; | |
1383 | ||
1384 | default: | |
1385 | abort (); | |
1386 | } | |
1387 | TREE_TYPE (t) = TREE_TYPE (arg1); | |
1388 | return t; | |
1389 | } | |
1390 | return 0; | |
1391 | } | |
1392 | \f | |
1393 | /* Return an INTEGER_CST with value V and type from `sizetype'. */ | |
1394 | ||
1395 | tree | |
1396 | size_int (number) | |
1397 | unsigned int number; | |
1398 | { | |
1399 | register tree t; | |
1400 | /* Type-size nodes already made for small sizes. */ | |
906c4e36 | 1401 | static tree size_table[2*HOST_BITS_PER_WIDE_INT + 1]; |
6d716ca8 | 1402 | |
906c4e36 RK |
1403 | if (number >= 0 && number < 2*HOST_BITS_PER_WIDE_INT + 1 |
1404 | && size_table[number] != 0) | |
6d716ca8 | 1405 | return size_table[number]; |
906c4e36 | 1406 | if (number >= 0 && number < 2*HOST_BITS_PER_WIDE_INT + 1) |
6d716ca8 | 1407 | { |
6d716ca8 RS |
1408 | push_obstacks_nochange (); |
1409 | /* Make this a permanent node. */ | |
c05a9b68 | 1410 | end_temporary_allocation (); |
6d716ca8 RS |
1411 | t = build_int_2 (number, 0); |
1412 | TREE_TYPE (t) = sizetype; | |
1413 | size_table[number] = t; | |
1414 | pop_obstacks (); | |
1415 | } | |
1416 | else | |
1417 | { | |
1418 | t = build_int_2 (number, 0); | |
1419 | TREE_TYPE (t) = sizetype; | |
1420 | } | |
1421 | return t; | |
1422 | } | |
1423 | ||
1424 | /* Combine operands OP1 and OP2 with arithmetic operation CODE. | |
1425 | CODE is a tree code. Data type is taken from `sizetype', | |
1426 | If the operands are constant, so is the result. */ | |
1427 | ||
1428 | tree | |
1429 | size_binop (code, arg0, arg1) | |
1430 | enum tree_code code; | |
1431 | tree arg0, arg1; | |
1432 | { | |
1433 | /* Handle the special case of two integer constants faster. */ | |
1434 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST) | |
1435 | { | |
1436 | /* And some specific cases even faster than that. */ | |
1437 | if (code == PLUS_EXPR | |
1438 | && TREE_INT_CST_LOW (arg0) == 0 | |
1439 | && TREE_INT_CST_HIGH (arg0) == 0) | |
1440 | return arg1; | |
1441 | if (code == MINUS_EXPR | |
1442 | && TREE_INT_CST_LOW (arg1) == 0 | |
1443 | && TREE_INT_CST_HIGH (arg1) == 0) | |
1444 | return arg0; | |
1445 | if (code == MULT_EXPR | |
1446 | && TREE_INT_CST_LOW (arg0) == 1 | |
1447 | && TREE_INT_CST_HIGH (arg0) == 0) | |
1448 | return arg1; | |
1449 | /* Handle general case of two integer constants. */ | |
1450 | return const_binop (code, arg0, arg1); | |
1451 | } | |
1452 | ||
1453 | if (arg0 == error_mark_node || arg1 == error_mark_node) | |
1454 | return error_mark_node; | |
1455 | ||
1456 | return fold (build (code, sizetype, arg0, arg1)); | |
1457 | } | |
1458 | \f | |
1459 | /* Given T, a tree representing type conversion of ARG1, a constant, | |
1460 | return a constant tree representing the result of conversion. */ | |
1461 | ||
1462 | static tree | |
1463 | fold_convert (t, arg1) | |
1464 | register tree t; | |
1465 | register tree arg1; | |
1466 | { | |
1467 | register tree type = TREE_TYPE (t); | |
1468 | ||
1469 | if (TREE_CODE (type) == POINTER_TYPE | |
1470 | || TREE_CODE (type) == INTEGER_TYPE | |
1471 | || TREE_CODE (type) == ENUMERAL_TYPE) | |
1472 | { | |
1473 | if (TREE_CODE (arg1) == INTEGER_CST) | |
1474 | { | |
1475 | /* Given an integer constant, make new constant with new type, | |
1476 | appropriately sign-extended or truncated. */ | |
1477 | t = build_int_2 (TREE_INT_CST_LOW (arg1), | |
1478 | TREE_INT_CST_HIGH (arg1)); | |
fe3e8e40 RS |
1479 | /* Carry forward overflow indication unless truncating. */ |
1480 | if (TYPE_PRECISION (type) >= TYPE_PRECISION (TREE_TYPE (t))) | |
1481 | TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg1); | |
6d716ca8 RS |
1482 | TREE_TYPE (t) = type; |
1483 | force_fit_type (t); | |
1484 | } | |
1485 | #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) | |
1486 | else if (TREE_CODE (arg1) == REAL_CST) | |
1487 | { | |
c05a9b68 RS |
1488 | REAL_VALUE_TYPE |
1489 | l = real_value_from_int_cst (TYPE_MIN_VALUE (type)), | |
1490 | x = TREE_REAL_CST (arg1), | |
1491 | u = real_value_from_int_cst (TYPE_MAX_VALUE (type)); | |
4b3d5ea0 RS |
1492 | /* See if X will be in range after truncation towards 0. |
1493 | To compensate for truncation, move the bounds away from 0, | |
1494 | but reject if X exactly equals the adjusted bounds. */ | |
1495 | #ifdef REAL_ARITHMETIC | |
1496 | REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1); | |
1497 | REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1); | |
1498 | #else | |
1499 | l--; | |
1500 | u++; | |
1501 | #endif | |
1502 | if (! (REAL_VALUES_LESS (l, x) && REAL_VALUES_LESS (x, u))) | |
6d716ca8 | 1503 | { |
fe3e8e40 | 1504 | pedwarn ("real constant out of range for integer conversion"); |
6d716ca8 RS |
1505 | return t; |
1506 | } | |
1507 | #ifndef REAL_ARITHMETIC | |
1508 | { | |
1509 | REAL_VALUE_TYPE d; | |
906c4e36 RK |
1510 | HOST_WIDE_INT low, high; |
1511 | HOST_WIDE_INT half_word | |
1512 | = (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2); | |
6d716ca8 RS |
1513 | |
1514 | d = TREE_REAL_CST (arg1); | |
1515 | if (d < 0) | |
1516 | d = -d; | |
1517 | ||
906c4e36 | 1518 | high = (HOST_WIDE_INT) (d / half_word / half_word); |
6d716ca8 | 1519 | d -= (REAL_VALUE_TYPE) high * half_word * half_word; |
906c4e36 | 1520 | low = (unsigned HOST_WIDE_INT) d; |
6d716ca8 RS |
1521 | if (TREE_REAL_CST (arg1) < 0) |
1522 | neg_double (low, high, &low, &high); | |
1523 | t = build_int_2 (low, high); | |
1524 | } | |
1525 | #else | |
1526 | { | |
906c4e36 | 1527 | HOST_WIDE_INT low, high; |
6d716ca8 RS |
1528 | REAL_VALUE_TO_INT (low, high, TREE_REAL_CST (arg1)); |
1529 | t = build_int_2 (low, high); | |
1530 | } | |
1531 | #endif | |
1532 | TREE_TYPE (t) = type; | |
1533 | force_fit_type (t); | |
1534 | } | |
1535 | #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */ | |
1536 | TREE_TYPE (t) = type; | |
1537 | } | |
1538 | else if (TREE_CODE (type) == REAL_TYPE) | |
1539 | { | |
1540 | #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) | |
1541 | if (TREE_CODE (arg1) == INTEGER_CST) | |
1542 | return build_real_from_int_cst (type, arg1); | |
1543 | #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */ | |
1544 | if (TREE_CODE (arg1) == REAL_CST) | |
7c7b029d RS |
1545 | { |
1546 | if (setjmp (float_error)) | |
1547 | { | |
fe3e8e40 | 1548 | pedwarn ("floating overflow in constant expression"); |
7c7b029d RS |
1549 | return t; |
1550 | } | |
1551 | set_float_handler (float_error); | |
1552 | ||
5352b11a | 1553 | t = build_real (type, real_value_truncate (TYPE_MODE (type), |
7c7b029d | 1554 | TREE_REAL_CST (arg1))); |
906c4e36 | 1555 | set_float_handler (NULL_PTR); |
7c7b029d RS |
1556 | return t; |
1557 | } | |
6d716ca8 RS |
1558 | } |
1559 | TREE_CONSTANT (t) = 1; | |
1560 | return t; | |
1561 | } | |
1562 | \f | |
1563 | /* Return an expr equal to X but certainly not valid as an lvalue. */ | |
1564 | ||
1565 | tree | |
1566 | non_lvalue (x) | |
1567 | tree x; | |
1568 | { | |
1569 | tree result; | |
1570 | ||
1571 | /* These things are certainly not lvalues. */ | |
1572 | if (TREE_CODE (x) == NON_LVALUE_EXPR | |
1573 | || TREE_CODE (x) == INTEGER_CST | |
1574 | || TREE_CODE (x) == REAL_CST | |
1575 | || TREE_CODE (x) == STRING_CST | |
1576 | || TREE_CODE (x) == ADDR_EXPR) | |
1577 | return x; | |
1578 | ||
1579 | result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x); | |
1580 | TREE_CONSTANT (result) = TREE_CONSTANT (x); | |
1581 | return result; | |
1582 | } | |
c05a9b68 RS |
1583 | \f |
1584 | /* Given a tree comparison code, return the code that is the logical inverse | |
1585 | of the given code. It is not safe to do this for floating-point | |
1586 | comparisons, except for NE_EXPR and EQ_EXPR. */ | |
6d716ca8 | 1587 | |
c05a9b68 RS |
1588 | static enum tree_code |
1589 | invert_tree_comparison (code) | |
1590 | enum tree_code code; | |
1591 | { | |
1592 | switch (code) | |
1593 | { | |
1594 | case EQ_EXPR: | |
1595 | return NE_EXPR; | |
1596 | case NE_EXPR: | |
1597 | return EQ_EXPR; | |
1598 | case GT_EXPR: | |
1599 | return LE_EXPR; | |
1600 | case GE_EXPR: | |
1601 | return LT_EXPR; | |
1602 | case LT_EXPR: | |
1603 | return GE_EXPR; | |
1604 | case LE_EXPR: | |
1605 | return GT_EXPR; | |
1606 | default: | |
1607 | abort (); | |
1608 | } | |
1609 | } | |
1610 | ||
1611 | /* Similar, but return the comparison that results if the operands are | |
1612 | swapped. This is safe for floating-point. */ | |
1613 | ||
1614 | static enum tree_code | |
1615 | swap_tree_comparison (code) | |
1616 | enum tree_code code; | |
1617 | { | |
1618 | switch (code) | |
1619 | { | |
1620 | case EQ_EXPR: | |
1621 | case NE_EXPR: | |
1622 | return code; | |
1623 | case GT_EXPR: | |
1624 | return LT_EXPR; | |
1625 | case GE_EXPR: | |
1626 | return LE_EXPR; | |
1627 | case LT_EXPR: | |
1628 | return GT_EXPR; | |
1629 | case LE_EXPR: | |
1630 | return GE_EXPR; | |
1631 | default: | |
1632 | abort (); | |
1633 | } | |
1634 | } | |
1635 | \f | |
6a1746af RS |
1636 | /* Return nonzero if two operands are necessarily equal. |
1637 | If ONLY_CONST is non-zero, only return non-zero for constants. | |
1638 | This function tests whether the operands are indistinguishable; | |
1639 | it does not test whether they are equal using C's == operation. | |
1640 | The distinction is important for IEEE floating point, because | |
1641 | (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and | |
1642 | (2) two NaNs may be indistinguishable, but NaN!=NaN. */ | |
6d716ca8 RS |
1643 | |
1644 | int | |
1645 | operand_equal_p (arg0, arg1, only_const) | |
1646 | tree arg0, arg1; | |
1647 | int only_const; | |
1648 | { | |
1649 | /* If both types don't have the same signedness, then we can't consider | |
1650 | them equal. We must check this before the STRIP_NOPS calls | |
1651 | because they may change the signedness of the arguments. */ | |
1652 | if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1))) | |
1653 | return 0; | |
1654 | ||
1655 | STRIP_NOPS (arg0); | |
1656 | STRIP_NOPS (arg1); | |
1657 | ||
1658 | /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal. | |
1659 | We don't care about side effects in that case because the SAVE_EXPR | |
1660 | takes care of that for us. */ | |
1661 | if (TREE_CODE (arg0) == SAVE_EXPR && arg0 == arg1) | |
1662 | return ! only_const; | |
1663 | ||
1664 | if (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)) | |
1665 | return 0; | |
1666 | ||
1667 | if (TREE_CODE (arg0) == TREE_CODE (arg1) | |
1668 | && TREE_CODE (arg0) == ADDR_EXPR | |
1669 | && TREE_OPERAND (arg0, 0) == TREE_OPERAND (arg1, 0)) | |
1670 | return 1; | |
1671 | ||
1672 | if (TREE_CODE (arg0) == TREE_CODE (arg1) | |
1673 | && TREE_CODE (arg0) == INTEGER_CST | |
1674 | && TREE_INT_CST_LOW (arg0) == TREE_INT_CST_LOW (arg1) | |
1675 | && TREE_INT_CST_HIGH (arg0) == TREE_INT_CST_HIGH (arg1)) | |
1676 | return 1; | |
1677 | ||
6a1746af | 1678 | /* Detect when real constants are equal. */ |
6d716ca8 | 1679 | if (TREE_CODE (arg0) == TREE_CODE (arg1) |
6a1746af RS |
1680 | && TREE_CODE (arg0) == REAL_CST) |
1681 | return !bcmp (&TREE_REAL_CST (arg0), &TREE_REAL_CST (arg1), | |
1682 | sizeof (REAL_VALUE_TYPE)); | |
6d716ca8 RS |
1683 | |
1684 | if (only_const) | |
1685 | return 0; | |
1686 | ||
1687 | if (arg0 == arg1) | |
1688 | return 1; | |
1689 | ||
1690 | if (TREE_CODE (arg0) != TREE_CODE (arg1)) | |
1691 | return 0; | |
1692 | /* This is needed for conversions and for COMPONENT_REF. | |
1693 | Might as well play it safe and always test this. */ | |
1694 | if (TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1))) | |
1695 | return 0; | |
1696 | ||
1697 | switch (TREE_CODE_CLASS (TREE_CODE (arg0))) | |
1698 | { | |
1699 | case '1': | |
1700 | /* Two conversions are equal only if signedness and modes match. */ | |
1701 | if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR) | |
1702 | && (TREE_UNSIGNED (TREE_TYPE (arg0)) | |
1703 | != TREE_UNSIGNED (TREE_TYPE (arg1)))) | |
1704 | return 0; | |
1705 | ||
1706 | return operand_equal_p (TREE_OPERAND (arg0, 0), | |
1707 | TREE_OPERAND (arg1, 0), 0); | |
1708 | ||
1709 | case '<': | |
1710 | case '2': | |
1711 | return (operand_equal_p (TREE_OPERAND (arg0, 0), | |
1712 | TREE_OPERAND (arg1, 0), 0) | |
1713 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
1714 | TREE_OPERAND (arg1, 1), 0)); | |
1715 | ||
1716 | case 'r': | |
1717 | switch (TREE_CODE (arg0)) | |
1718 | { | |
1719 | case INDIRECT_REF: | |
1720 | return operand_equal_p (TREE_OPERAND (arg0, 0), | |
1721 | TREE_OPERAND (arg1, 0), 0); | |
1722 | ||
1723 | case COMPONENT_REF: | |
1724 | case ARRAY_REF: | |
1725 | return (operand_equal_p (TREE_OPERAND (arg0, 0), | |
1726 | TREE_OPERAND (arg1, 0), 0) | |
1727 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
1728 | TREE_OPERAND (arg1, 1), 0)); | |
1729 | ||
1730 | case BIT_FIELD_REF: | |
1731 | return (operand_equal_p (TREE_OPERAND (arg0, 0), | |
1732 | TREE_OPERAND (arg1, 0), 0) | |
1733 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
1734 | TREE_OPERAND (arg1, 1), 0) | |
1735 | && operand_equal_p (TREE_OPERAND (arg0, 2), | |
1736 | TREE_OPERAND (arg1, 2), 0)); | |
1737 | } | |
1738 | break; | |
1739 | } | |
1740 | ||
1741 | return 0; | |
1742 | } | |
c05a9b68 RS |
1743 | \f |
1744 | /* Similar to operand_equal_p, but see if ARG0 might have been made by | |
1745 | shorten_compare from ARG1 when ARG1 was being compared with OTHER. | |
6d716ca8 | 1746 | |
6d716ca8 RS |
1747 | When in doubt, return 0. */ |
1748 | ||
1749 | static int | |
c05a9b68 RS |
1750 | operand_equal_for_comparison_p (arg0, arg1, other) |
1751 | tree arg0, arg1; | |
1752 | tree other; | |
6d716ca8 | 1753 | { |
c05a9b68 RS |
1754 | int unsignedp1, unsignedpo; |
1755 | tree primarg1, primother; | |
6d716ca8 RS |
1756 | int correct_width; |
1757 | ||
c05a9b68 | 1758 | if (operand_equal_p (arg0, arg1, 0)) |
6d716ca8 RS |
1759 | return 1; |
1760 | ||
c05a9b68 | 1761 | if (TREE_CODE (TREE_TYPE (arg0)) != INTEGER_TYPE) |
6d716ca8 RS |
1762 | return 0; |
1763 | ||
c05a9b68 RS |
1764 | /* Duplicate what shorten_compare does to ARG1 and see if that gives the |
1765 | actual comparison operand, ARG0. | |
6d716ca8 | 1766 | |
c05a9b68 | 1767 | First throw away any conversions to wider types |
6d716ca8 | 1768 | already present in the operands. */ |
6d716ca8 | 1769 | |
c05a9b68 RS |
1770 | primarg1 = get_narrower (arg1, &unsignedp1); |
1771 | primother = get_narrower (other, &unsignedpo); | |
1772 | ||
1773 | correct_width = TYPE_PRECISION (TREE_TYPE (arg1)); | |
1774 | if (unsignedp1 == unsignedpo | |
1775 | && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width | |
1776 | && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width) | |
6d716ca8 | 1777 | { |
c05a9b68 | 1778 | tree type = TREE_TYPE (arg0); |
6d716ca8 RS |
1779 | |
1780 | /* Make sure shorter operand is extended the right way | |
1781 | to match the longer operand. */ | |
c05a9b68 RS |
1782 | primarg1 = convert (signed_or_unsigned_type (unsignedp1, |
1783 | TREE_TYPE (primarg1)), | |
1784 | primarg1); | |
6d716ca8 | 1785 | |
c05a9b68 | 1786 | if (operand_equal_p (arg0, convert (type, primarg1), 0)) |
6d716ca8 RS |
1787 | return 1; |
1788 | } | |
1789 | ||
1790 | return 0; | |
1791 | } | |
1792 | \f | |
f72aed24 | 1793 | /* See if ARG is an expression that is either a comparison or is performing |
c05a9b68 RS |
1794 | arithmetic on comparisons. The comparisons must only be comparing |
1795 | two different values, which will be stored in *CVAL1 and *CVAL2; if | |
1796 | they are non-zero it means that some operands have already been found. | |
1797 | No variables may be used anywhere else in the expression except in the | |
1798 | comparisons. | |
1799 | ||
1800 | If this is true, return 1. Otherwise, return zero. */ | |
1801 | ||
1802 | static int | |
1803 | twoval_comparison_p (arg, cval1, cval2) | |
1804 | tree arg; | |
1805 | tree *cval1, *cval2; | |
1806 | { | |
1807 | enum tree_code code = TREE_CODE (arg); | |
1808 | char class = TREE_CODE_CLASS (code); | |
1809 | ||
1810 | /* We can handle some of the 'e' cases here. */ | |
1811 | if (class == 'e' | |
1812 | && (code == TRUTH_NOT_EXPR | |
1813 | || (code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0))) | |
1814 | class = '1'; | |
1815 | else if (class == 'e' | |
1816 | && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR | |
1817 | || code == COMPOUND_EXPR)) | |
1818 | class = '2'; | |
1819 | ||
1820 | switch (class) | |
1821 | { | |
1822 | case '1': | |
1823 | return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2); | |
1824 | ||
1825 | case '2': | |
1826 | return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2) | |
1827 | && twoval_comparison_p (TREE_OPERAND (arg, 1), cval1, cval2)); | |
1828 | ||
1829 | case 'c': | |
1830 | return 1; | |
1831 | ||
1832 | case 'e': | |
1833 | if (code == COND_EXPR) | |
1834 | return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2) | |
1835 | && twoval_comparison_p (TREE_OPERAND (arg, 1), cval1, cval2) | |
1836 | && twoval_comparison_p (TREE_OPERAND (arg, 2), | |
1837 | cval1, cval2)); | |
1838 | return 0; | |
1839 | ||
1840 | case '<': | |
1841 | /* First see if we can handle the first operand, then the second. For | |
1842 | the second operand, we know *CVAL1 can't be zero. It must be that | |
1843 | one side of the comparison is each of the values; test for the | |
1844 | case where this isn't true by failing if the two operands | |
1845 | are the same. */ | |
1846 | ||
1847 | if (operand_equal_p (TREE_OPERAND (arg, 0), | |
1848 | TREE_OPERAND (arg, 1), 0)) | |
1849 | return 0; | |
1850 | ||
1851 | if (*cval1 == 0) | |
1852 | *cval1 = TREE_OPERAND (arg, 0); | |
1853 | else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0)) | |
1854 | ; | |
1855 | else if (*cval2 == 0) | |
1856 | *cval2 = TREE_OPERAND (arg, 0); | |
1857 | else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0)) | |
1858 | ; | |
1859 | else | |
1860 | return 0; | |
1861 | ||
1862 | if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0)) | |
1863 | ; | |
1864 | else if (*cval2 == 0) | |
1865 | *cval2 = TREE_OPERAND (arg, 1); | |
1866 | else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0)) | |
1867 | ; | |
1868 | else | |
1869 | return 0; | |
1870 | ||
1871 | return 1; | |
1872 | } | |
1873 | ||
1874 | return 0; | |
1875 | } | |
1876 | \f | |
1877 | /* ARG is a tree that is known to contain just arithmetic operations and | |
1878 | comparisons. Evaluate the operations in the tree substituting NEW0 for | |
f72aed24 | 1879 | any occurrence of OLD0 as an operand of a comparison and likewise for |
c05a9b68 RS |
1880 | NEW1 and OLD1. */ |
1881 | ||
1882 | static tree | |
1883 | eval_subst (arg, old0, new0, old1, new1) | |
1884 | tree arg; | |
1885 | tree old0, new0, old1, new1; | |
1886 | { | |
1887 | tree type = TREE_TYPE (arg); | |
1888 | enum tree_code code = TREE_CODE (arg); | |
1889 | char class = TREE_CODE_CLASS (code); | |
1890 | ||
1891 | /* We can handle some of the 'e' cases here. */ | |
1892 | if (class == 'e' && code == TRUTH_NOT_EXPR) | |
1893 | class = '1'; | |
1894 | else if (class == 'e' | |
1895 | && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)) | |
1896 | class = '2'; | |
1897 | ||
1898 | switch (class) | |
1899 | { | |
1900 | case '1': | |
1901 | return fold (build1 (code, type, | |
1902 | eval_subst (TREE_OPERAND (arg, 0), | |
1903 | old0, new0, old1, new1))); | |
1904 | ||
1905 | case '2': | |
1906 | return fold (build (code, type, | |
1907 | eval_subst (TREE_OPERAND (arg, 0), | |
1908 | old0, new0, old1, new1), | |
1909 | eval_subst (TREE_OPERAND (arg, 1), | |
1910 | old0, new0, old1, new1))); | |
1911 | ||
1912 | case 'e': | |
1913 | switch (code) | |
1914 | { | |
1915 | case SAVE_EXPR: | |
1916 | return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1); | |
1917 | ||
1918 | case COMPOUND_EXPR: | |
1919 | return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1); | |
1920 | ||
1921 | case COND_EXPR: | |
1922 | return fold (build (code, type, | |
1923 | eval_subst (TREE_OPERAND (arg, 0), | |
1924 | old0, new0, old1, new1), | |
1925 | eval_subst (TREE_OPERAND (arg, 1), | |
1926 | old0, new0, old1, new1), | |
1927 | eval_subst (TREE_OPERAND (arg, 2), | |
1928 | old0, new0, old1, new1))); | |
1929 | } | |
1930 | ||
1931 | case '<': | |
1932 | { | |
1933 | tree arg0 = TREE_OPERAND (arg, 0); | |
1934 | tree arg1 = TREE_OPERAND (arg, 1); | |
1935 | ||
1936 | /* We need to check both for exact equality and tree equality. The | |
1937 | former will be true if the operand has a side-effect. In that | |
1938 | case, we know the operand occurred exactly once. */ | |
1939 | ||
1940 | if (arg0 == old0 || operand_equal_p (arg0, old0, 0)) | |
1941 | arg0 = new0; | |
1942 | else if (arg0 == old1 || operand_equal_p (arg0, old1, 0)) | |
1943 | arg0 = new1; | |
1944 | ||
1945 | if (arg1 == old0 || operand_equal_p (arg1, old0, 0)) | |
1946 | arg1 = new0; | |
1947 | else if (arg1 == old1 || operand_equal_p (arg1, old1, 0)) | |
1948 | arg1 = new1; | |
1949 | ||
1950 | return fold (build (code, type, arg0, arg1)); | |
1951 | } | |
1952 | } | |
1953 | ||
1954 | return arg; | |
1955 | } | |
1956 | \f | |
6d716ca8 RS |
1957 | /* Return a tree for the case when the result of an expression is RESULT |
1958 | converted to TYPE and OMITTED was previously an operand of the expression | |
1959 | but is now not needed (e.g., we folded OMITTED * 0). | |
1960 | ||
1961 | If OMITTED has side effects, we must evaluate it. Otherwise, just do | |
1962 | the conversion of RESULT to TYPE. */ | |
1963 | ||
1964 | static tree | |
1965 | omit_one_operand (type, result, omitted) | |
1966 | tree type, result, omitted; | |
1967 | { | |
1968 | tree t = convert (type, result); | |
1969 | ||
1970 | if (TREE_SIDE_EFFECTS (omitted)) | |
1971 | return build (COMPOUND_EXPR, type, omitted, t); | |
1972 | ||
1973 | return t; | |
1974 | } | |
1975 | \f | |
1976 | /* Return a simplified tree node for the truth-negation of ARG | |
1977 | (perhaps by altering ARG). It is known that ARG is an operation that | |
1978 | returns a truth value (0 or 1). */ | |
1979 | ||
1980 | tree | |
1981 | invert_truthvalue (arg) | |
1982 | tree arg; | |
1983 | { | |
1984 | tree type = TREE_TYPE (arg); | |
c05a9b68 | 1985 | enum tree_code code = TREE_CODE (arg); |
6d716ca8 | 1986 | |
c05a9b68 RS |
1987 | /* If this is a comparison, we can simply invert it, except for |
1988 | floating-point non-equality comparisons, in which case we just | |
1989 | enclose a TRUTH_NOT_EXPR around what we have. */ | |
6d716ca8 | 1990 | |
c05a9b68 | 1991 | if (TREE_CODE_CLASS (code) == '<') |
6d716ca8 | 1992 | { |
c05a9b68 RS |
1993 | if (TREE_CODE (TREE_TYPE (TREE_OPERAND (arg, 0))) == REAL_TYPE |
1994 | && code != NE_EXPR && code != EQ_EXPR) | |
1995 | return build1 (TRUTH_NOT_EXPR, type, arg); | |
1996 | else | |
1997 | { | |
1998 | TREE_SET_CODE (arg, invert_tree_comparison (code)); | |
1999 | return arg; | |
2000 | } | |
2001 | } | |
6d716ca8 | 2002 | |
c05a9b68 RS |
2003 | switch (code) |
2004 | { | |
6d716ca8 RS |
2005 | case INTEGER_CST: |
2006 | return convert (type, build_int_2 (TREE_INT_CST_LOW (arg) == 0 | |
2007 | && TREE_INT_CST_HIGH (arg) == 0, 0)); | |
2008 | ||
2009 | case TRUTH_AND_EXPR: | |
2010 | return build (TRUTH_OR_EXPR, type, | |
2011 | invert_truthvalue (TREE_OPERAND (arg, 0)), | |
2012 | invert_truthvalue (TREE_OPERAND (arg, 1))); | |
2013 | ||
2014 | case TRUTH_OR_EXPR: | |
2015 | return build (TRUTH_AND_EXPR, type, | |
2016 | invert_truthvalue (TREE_OPERAND (arg, 0)), | |
2017 | invert_truthvalue (TREE_OPERAND (arg, 1))); | |
2018 | ||
2019 | case TRUTH_ANDIF_EXPR: | |
2020 | return build (TRUTH_ORIF_EXPR, type, | |
2021 | invert_truthvalue (TREE_OPERAND (arg, 0)), | |
2022 | invert_truthvalue (TREE_OPERAND (arg, 1))); | |
2023 | ||
2024 | case TRUTH_ORIF_EXPR: | |
2025 | return build (TRUTH_ANDIF_EXPR, type, | |
2026 | invert_truthvalue (TREE_OPERAND (arg, 0)), | |
2027 | invert_truthvalue (TREE_OPERAND (arg, 1))); | |
2028 | ||
2029 | case TRUTH_NOT_EXPR: | |
2030 | return TREE_OPERAND (arg, 0); | |
2031 | ||
2032 | case COND_EXPR: | |
2033 | return build (COND_EXPR, type, TREE_OPERAND (arg, 0), | |
2034 | invert_truthvalue (TREE_OPERAND (arg, 1)), | |
2035 | invert_truthvalue (TREE_OPERAND (arg, 2))); | |
2036 | ||
ef9fe0da RK |
2037 | case COMPOUND_EXPR: |
2038 | return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0), | |
2039 | invert_truthvalue (TREE_OPERAND (arg, 1))); | |
2040 | ||
6d716ca8 RS |
2041 | case NON_LVALUE_EXPR: |
2042 | return invert_truthvalue (TREE_OPERAND (arg, 0)); | |
2043 | ||
2044 | case NOP_EXPR: | |
2045 | case CONVERT_EXPR: | |
2046 | case FLOAT_EXPR: | |
2047 | return build1 (TREE_CODE (arg), type, | |
2048 | invert_truthvalue (TREE_OPERAND (arg, 0))); | |
2049 | ||
2050 | case BIT_AND_EXPR: | |
2051 | if (! integer_onep (TREE_OPERAND (arg, 1))) | |
2052 | abort (); | |
2053 | return build (EQ_EXPR, type, arg, convert (type, integer_zero_node)); | |
2054 | } | |
2055 | ||
2056 | abort (); | |
2057 | } | |
2058 | ||
2059 | /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both | |
2060 | operands are another bit-wise operation with a common input. If so, | |
2061 | distribute the bit operations to save an operation and possibly two if | |
2062 | constants are involved. For example, convert | |
2063 | (A | B) & (A | C) into A | (B & C) | |
2064 | Further simplification will occur if B and C are constants. | |
2065 | ||
2066 | If this optimization cannot be done, 0 will be returned. */ | |
2067 | ||
2068 | static tree | |
2069 | distribute_bit_expr (code, type, arg0, arg1) | |
2070 | enum tree_code code; | |
2071 | tree type; | |
2072 | tree arg0, arg1; | |
2073 | { | |
2074 | tree common; | |
2075 | tree left, right; | |
2076 | ||
2077 | if (TREE_CODE (arg0) != TREE_CODE (arg1) | |
2078 | || TREE_CODE (arg0) == code | |
9c0ae98b CH |
2079 | || (TREE_CODE (arg0) != TRUTH_AND_EXPR |
2080 | && TREE_CODE (arg0) != TRUTH_OR_EXPR)) | |
6d716ca8 RS |
2081 | return 0; |
2082 | ||
2083 | if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)) | |
2084 | { | |
2085 | common = TREE_OPERAND (arg0, 0); | |
2086 | left = TREE_OPERAND (arg0, 1); | |
2087 | right = TREE_OPERAND (arg1, 1); | |
2088 | } | |
2089 | else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0)) | |
2090 | { | |
2091 | common = TREE_OPERAND (arg0, 0); | |
2092 | left = TREE_OPERAND (arg0, 1); | |
2093 | right = TREE_OPERAND (arg1, 0); | |
2094 | } | |
2095 | else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0)) | |
2096 | { | |
2097 | common = TREE_OPERAND (arg0, 1); | |
2098 | left = TREE_OPERAND (arg0, 0); | |
2099 | right = TREE_OPERAND (arg1, 1); | |
2100 | } | |
2101 | else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0)) | |
2102 | { | |
2103 | common = TREE_OPERAND (arg0, 1); | |
2104 | left = TREE_OPERAND (arg0, 0); | |
2105 | right = TREE_OPERAND (arg1, 0); | |
2106 | } | |
2107 | else | |
2108 | return 0; | |
2109 | ||
2110 | return fold (build (TREE_CODE (arg0), type, common, | |
2111 | fold (build (code, type, left, right)))); | |
2112 | } | |
2113 | \f | |
2114 | /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER | |
2115 | starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */ | |
2116 | ||
2117 | static tree | |
2118 | make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp) | |
2119 | tree inner; | |
2120 | tree type; | |
2121 | int bitsize, bitpos; | |
2122 | int unsignedp; | |
2123 | { | |
2124 | tree result = build (BIT_FIELD_REF, type, inner, | |
2125 | size_int (bitsize), size_int (bitpos)); | |
2126 | ||
2127 | TREE_UNSIGNED (result) = unsignedp; | |
2128 | ||
2129 | return result; | |
2130 | } | |
2131 | ||
2132 | /* Optimize a bit-field compare. | |
2133 | ||
2134 | There are two cases: First is a compare against a constant and the | |
2135 | second is a comparison of two items where the fields are at the same | |
2136 | bit position relative to the start of a chunk (byte, halfword, word) | |
2137 | large enough to contain it. In these cases we can avoid the shift | |
2138 | implicit in bitfield extractions. | |
2139 | ||
2140 | For constants, we emit a compare of the shifted constant with the | |
2141 | BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being | |
2142 | compared. For two fields at the same position, we do the ANDs with the | |
2143 | similar mask and compare the result of the ANDs. | |
2144 | ||
2145 | CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR. | |
2146 | COMPARE_TYPE is the type of the comparison, and LHS and RHS | |
2147 | are the left and right operands of the comparison, respectively. | |
2148 | ||
6dc42e49 | 2149 | If the optimization described above can be done, we return the resulting |
6d716ca8 RS |
2150 | tree. Otherwise we return zero. */ |
2151 | ||
2152 | static tree | |
2153 | optimize_bit_field_compare (code, compare_type, lhs, rhs) | |
2154 | enum tree_code code; | |
2155 | tree compare_type; | |
2156 | tree lhs, rhs; | |
2157 | { | |
2158 | int lbitpos, lbitsize, rbitpos, rbitsize; | |
2159 | int lnbitpos, lnbitsize, rnbitpos, rnbitsize; | |
2160 | tree type = TREE_TYPE (lhs); | |
2161 | tree signed_type, unsigned_type; | |
2162 | int const_p = TREE_CODE (rhs) == INTEGER_CST; | |
2163 | enum machine_mode lmode, rmode, lnmode, rnmode; | |
2164 | int lunsignedp, runsignedp; | |
2165 | int lvolatilep = 0, rvolatilep = 0; | |
2166 | tree linner, rinner; | |
2167 | tree mask; | |
f1e60ec6 | 2168 | tree offset; |
6d716ca8 RS |
2169 | |
2170 | /* Get all the information about the extractions being done. If the bit size | |
2171 | if the same as the size of the underlying object, we aren't doing an | |
2172 | extraction at all and so can do nothing. */ | |
f1e60ec6 | 2173 | linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode, |
6d716ca8 | 2174 | &lunsignedp, &lvolatilep); |
f1e60ec6 RS |
2175 | if (lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0 |
2176 | || offset != 0) | |
6d716ca8 RS |
2177 | return 0; |
2178 | ||
2179 | if (!const_p) | |
2180 | { | |
2181 | /* If this is not a constant, we can only do something if bit positions, | |
2182 | sizes, and signedness are the same. */ | |
f1e60ec6 | 2183 | rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, |
6d716ca8 RS |
2184 | &rmode, &runsignedp, &rvolatilep); |
2185 | ||
2186 | if (lbitpos != rbitpos || lbitsize != rbitsize | |
f1e60ec6 | 2187 | || lunsignedp != runsignedp || offset != 0) |
6d716ca8 RS |
2188 | return 0; |
2189 | } | |
2190 | ||
2191 | /* See if we can find a mode to refer to this field. We should be able to, | |
2192 | but fail if we can't. */ | |
2193 | lnmode = get_best_mode (lbitsize, lbitpos, | |
2194 | TYPE_ALIGN (TREE_TYPE (linner)), word_mode, | |
2195 | lvolatilep); | |
2196 | if (lnmode == VOIDmode) | |
2197 | return 0; | |
2198 | ||
2199 | /* Set signed and unsigned types of the precision of this mode for the | |
2200 | shifts below. */ | |
2201 | signed_type = type_for_mode (lnmode, 0); | |
2202 | unsigned_type = type_for_mode (lnmode, 1); | |
2203 | ||
2204 | if (! const_p) | |
2205 | { | |
2206 | rnmode = get_best_mode (rbitsize, rbitpos, | |
2207 | TYPE_ALIGN (TREE_TYPE (rinner)), word_mode, | |
2208 | rvolatilep); | |
2209 | if (rnmode == VOIDmode) | |
2210 | return 0; | |
2211 | } | |
2212 | ||
2213 | /* Compute the bit position and size for the new reference and our offset | |
2214 | within it. If the new reference is the same size as the original, we | |
2215 | won't optimize anything, so return zero. */ | |
2216 | lnbitsize = GET_MODE_BITSIZE (lnmode); | |
2217 | lnbitpos = lbitpos & ~ (lnbitsize - 1); | |
2218 | lbitpos -= lnbitpos; | |
2219 | if (lnbitsize == lbitsize) | |
2220 | return 0; | |
2221 | ||
2222 | if (! const_p) | |
2223 | { | |
2224 | rnbitsize = GET_MODE_BITSIZE (rnmode); | |
2225 | rnbitpos = rbitpos & ~ (rnbitsize - 1); | |
2226 | rbitpos -= rnbitpos; | |
2227 | if (rnbitsize == rbitsize) | |
2228 | return 0; | |
2229 | } | |
2230 | ||
2231 | #if BYTES_BIG_ENDIAN | |
2232 | lbitpos = lnbitsize - lbitsize - lbitpos; | |
6d716ca8 RS |
2233 | #endif |
2234 | ||
2235 | /* Make the mask to be used against the extracted field. */ | |
2236 | mask = convert (unsigned_type, build_int_2 (~0, ~0)); | |
2237 | mask = const_binop (LSHIFT_EXPR, mask, size_int (lnbitsize - lbitsize)); | |
2238 | mask = const_binop (RSHIFT_EXPR, mask, | |
2239 | size_int (lnbitsize - lbitsize - lbitpos)); | |
2240 | ||
2241 | if (! const_p) | |
2242 | /* If not comparing with constant, just rework the comparison | |
2243 | and return. */ | |
2244 | return build (code, compare_type, | |
c0b9d4c8 RK |
2245 | build (BIT_AND_EXPR, unsigned_type, |
2246 | make_bit_field_ref (linner, unsigned_type, | |
2247 | lnbitsize, lnbitpos, 1), | |
6d716ca8 | 2248 | mask), |
c0b9d4c8 RK |
2249 | build (BIT_AND_EXPR, unsigned_type, |
2250 | make_bit_field_ref (rinner, unsigned_type, | |
2251 | rnbitsize, rnbitpos, 1), | |
6d716ca8 RS |
2252 | mask)); |
2253 | ||
2254 | /* Otherwise, we are handling the constant case. See if the constant is too | |
2255 | big for the field. Warn and return a tree of for 0 (false) if so. We do | |
2256 | this not only for its own sake, but to avoid having to test for this | |
2257 | error case below. If we didn't, we might generate wrong code. | |
2258 | ||
2259 | For unsigned fields, the constant shifted right by the field length should | |
2260 | be all zero. For signed fields, the high-order bits should agree with | |
2261 | the sign bit. */ | |
2262 | ||
2263 | if (lunsignedp) | |
2264 | { | |
2265 | if (! integer_zerop (const_binop (RSHIFT_EXPR, | |
2266 | convert (unsigned_type, rhs), | |
2267 | size_int (lbitsize)))) | |
2268 | { | |
2269 | warning ("comparison is always %s due to width of bitfield", | |
2270 | code == NE_EXPR ? "one" : "zero"); | |
2271 | return convert (compare_type, | |
2272 | (code == NE_EXPR | |
2273 | ? integer_one_node : integer_zero_node)); | |
2274 | } | |
2275 | } | |
2276 | else | |
2277 | { | |
2278 | tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs), | |
2279 | size_int (lbitsize - 1)); | |
2280 | if (! integer_zerop (tem) && ! integer_all_onesp (tem)) | |
2281 | { | |
2282 | warning ("comparison is always %s due to width of bitfield", | |
2283 | code == NE_EXPR ? "one" : "zero"); | |
2284 | return convert (compare_type, | |
2285 | (code == NE_EXPR | |
2286 | ? integer_one_node : integer_zero_node)); | |
2287 | } | |
2288 | } | |
2289 | ||
2290 | /* Single-bit compares should always be against zero. */ | |
2291 | if (lbitsize == 1 && ! integer_zerop (rhs)) | |
2292 | { | |
2293 | code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR; | |
2294 | rhs = convert (type, integer_zero_node); | |
2295 | } | |
2296 | ||
2297 | /* Make a new bitfield reference, shift the constant over the | |
2298 | appropriate number of bits and mask it with the computed mask | |
2299 | (in case this was a signed field). If we changed it, make a new one. */ | |
c0b9d4c8 | 2300 | lhs = make_bit_field_ref (linner, unsigned_type, lnbitsize, lnbitpos, 1); |
6d716ca8 | 2301 | |
c0b9d4c8 RK |
2302 | rhs = fold (const_binop (BIT_AND_EXPR, |
2303 | const_binop (LSHIFT_EXPR, | |
2304 | convert (unsigned_type, rhs), | |
2305 | size_int (lbitpos)), | |
2306 | mask)); | |
6d716ca8 RS |
2307 | |
2308 | return build (code, compare_type, | |
c0b9d4c8 | 2309 | build (BIT_AND_EXPR, unsigned_type, lhs, mask), |
6d716ca8 RS |
2310 | rhs); |
2311 | } | |
2312 | \f | |
b2215d83 | 2313 | /* Subroutine for fold_truthop: decode a field reference. |
6d716ca8 RS |
2314 | |
2315 | If EXP is a comparison reference, we return the innermost reference. | |
2316 | ||
2317 | *PBITSIZE is set to the number of bits in the reference, *PBITPOS is | |
2318 | set to the starting bit number. | |
2319 | ||
2320 | If the innermost field can be completely contained in a mode-sized | |
2321 | unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode. | |
2322 | ||
2323 | *PVOLATILEP is set to 1 if the any expression encountered is volatile; | |
2324 | otherwise it is not changed. | |
2325 | ||
2326 | *PUNSIGNEDP is set to the signedness of the field. | |
2327 | ||
2328 | *PMASK is set to the mask used. This is either contained in a | |
2329 | BIT_AND_EXPR or derived from the width of the field. | |
2330 | ||
2331 | Return 0 if this is not a component reference or is one that we can't | |
2332 | do anything with. */ | |
2333 | ||
2334 | static tree | |
2335 | decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp, | |
2336 | pvolatilep, pmask) | |
2337 | tree exp; | |
2338 | int *pbitsize, *pbitpos; | |
2339 | enum machine_mode *pmode; | |
2340 | int *punsignedp, *pvolatilep; | |
2341 | tree *pmask; | |
2342 | { | |
2343 | tree mask = 0; | |
2344 | tree inner; | |
f1e60ec6 | 2345 | tree offset; |
6d716ca8 RS |
2346 | |
2347 | STRIP_NOPS (exp); | |
2348 | ||
2349 | if (TREE_CODE (exp) == BIT_AND_EXPR) | |
2350 | { | |
2351 | mask = TREE_OPERAND (exp, 1); | |
2352 | exp = TREE_OPERAND (exp, 0); | |
2353 | STRIP_NOPS (exp); STRIP_NOPS (mask); | |
2354 | if (TREE_CODE (mask) != INTEGER_CST) | |
2355 | return 0; | |
2356 | } | |
2357 | ||
2358 | if (TREE_CODE (exp) != COMPONENT_REF && TREE_CODE (exp) != ARRAY_REF | |
2359 | && TREE_CODE (exp) != BIT_FIELD_REF) | |
2360 | return 0; | |
2361 | ||
f1e60ec6 | 2362 | inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode, |
6d716ca8 | 2363 | punsignedp, pvolatilep); |
f1e60ec6 | 2364 | if (*pbitsize < 0 || offset != 0) |
c05a9b68 | 2365 | return 0; |
6d716ca8 RS |
2366 | |
2367 | if (mask == 0) | |
2368 | { | |
2369 | tree unsigned_type = type_for_size (*pbitsize, 1); | |
2370 | int precision = TYPE_PRECISION (unsigned_type); | |
2371 | ||
2372 | mask = convert (unsigned_type, build_int_2 (~0, ~0)); | |
2373 | mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize)); | |
2374 | mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize)); | |
2375 | } | |
2376 | ||
2377 | *pmask = mask; | |
2378 | return inner; | |
2379 | } | |
2380 | ||
6dc42e49 | 2381 | /* Return non-zero if MASK represents a mask of SIZE ones in the low-order |
6d716ca8 RS |
2382 | bit positions. */ |
2383 | ||
2384 | static int | |
2385 | all_ones_mask_p (mask, size) | |
2386 | tree mask; | |
2387 | int size; | |
2388 | { | |
2389 | tree type = TREE_TYPE (mask); | |
2390 | int precision = TYPE_PRECISION (type); | |
2391 | ||
2392 | return | |
2393 | operand_equal_p (mask, | |
2394 | const_binop (RSHIFT_EXPR, | |
2395 | const_binop (LSHIFT_EXPR, | |
2396 | convert (signed_type (type), | |
2397 | build_int_2 (~0, ~0)), | |
2398 | size_int (precision - size)), | |
2399 | size_int (precision - size)), 0); | |
2400 | } | |
b2215d83 TW |
2401 | |
2402 | /* Subroutine for fold_truthop: determine if an operand is simple enough | |
2403 | to be evaluated unconditionally. */ | |
2404 | ||
2405 | #ifdef __GNUC__ | |
2406 | __inline | |
2407 | #endif | |
2408 | static int | |
2409 | simple_operand_p (exp) | |
2410 | tree exp; | |
2411 | { | |
2412 | /* Strip any conversions that don't change the machine mode. */ | |
2413 | while ((TREE_CODE (exp) == NOP_EXPR | |
2414 | || TREE_CODE (exp) == CONVERT_EXPR) | |
2415 | && (TYPE_MODE (TREE_TYPE (exp)) | |
2416 | == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0))))) | |
2417 | exp = TREE_OPERAND (exp, 0); | |
2418 | ||
2419 | return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c' | |
2420 | || (TREE_CODE_CLASS (TREE_CODE (exp)) == 'd' | |
2421 | && ! TREE_ADDRESSABLE (exp) | |
2422 | && ! TREE_THIS_VOLATILE (exp) | |
0924ddef | 2423 | && ! DECL_NONLOCAL (exp))); |
b2215d83 | 2424 | } |
6d716ca8 | 2425 | \f |
b2215d83 | 2426 | /* Subroutine for fold_truthop: try to optimize a range test. |
ef659ec0 TW |
2427 | |
2428 | For example, "i >= 2 && i =< 9" can be done as "(unsigned) (i - 2) <= 7". | |
2429 | ||
9c0ae98b CH |
2430 | JCODE is the logical combination of the two terms. It is TRUTH_AND_EXPR |
2431 | (representing TRUTH_ANDIF_EXPR and TRUTH_AND_EXPR) or TRUTH_OR_EXPR | |
b2215d83 TW |
2432 | (representing TRUTH_ORIF_EXPR and TRUTH_OR_EXPR). TYPE is the type of |
2433 | the result. | |
ef659ec0 TW |
2434 | |
2435 | VAR is the value being tested. LO_CODE and HI_CODE are the comparison | |
2436 | operators comparing VAR to LO_CST and HI_CST. LO_CST is known to be no | |
2437 | larger than HI_CST (they may be equal). | |
2438 | ||
2439 | We return the simplified tree or 0 if no optimization is possible. */ | |
2440 | ||
2441 | tree | |
2442 | range_test (jcode, type, lo_code, hi_code, var, lo_cst, hi_cst) | |
2443 | enum tree_code jcode, lo_code, hi_code; | |
2444 | tree type, var, lo_cst, hi_cst; | |
2445 | { | |
2446 | tree utype; | |
2447 | enum tree_code rcode; | |
2448 | ||
2449 | /* See if this is a range test and normalize the constant terms. */ | |
2450 | ||
9c0ae98b | 2451 | if (jcode == TRUTH_AND_EXPR) |
ef659ec0 TW |
2452 | { |
2453 | switch (lo_code) | |
2454 | { | |
2455 | case NE_EXPR: | |
2456 | /* See if we have VAR != CST && VAR != CST+1. */ | |
2457 | if (! (hi_code == NE_EXPR | |
2458 | && TREE_INT_CST_LOW (hi_cst) - TREE_INT_CST_LOW (lo_cst) == 1 | |
2459 | && tree_int_cst_equal (integer_one_node, | |
2460 | const_binop (MINUS_EXPR, | |
2461 | hi_cst, lo_cst)))) | |
2462 | return 0; | |
2463 | ||
2464 | rcode = GT_EXPR; | |
2465 | break; | |
2466 | ||
2467 | case GT_EXPR: | |
2468 | case GE_EXPR: | |
2469 | if (hi_code == LT_EXPR) | |
2470 | hi_cst = const_binop (MINUS_EXPR, hi_cst, integer_one_node); | |
2471 | else if (hi_code != LE_EXPR) | |
2472 | return 0; | |
2473 | ||
2474 | if (lo_code == GT_EXPR) | |
2475 | lo_cst = const_binop (PLUS_EXPR, lo_cst, integer_one_node); | |
2476 | ||
2477 | /* We now have VAR >= LO_CST && VAR <= HI_CST. */ | |
2478 | rcode = LE_EXPR; | |
2479 | break; | |
2480 | ||
2481 | default: | |
2482 | return 0; | |
2483 | } | |
2484 | } | |
2485 | else | |
2486 | { | |
2487 | switch (lo_code) | |
2488 | { | |
2489 | case EQ_EXPR: | |
2490 | /* See if we have VAR == CST || VAR == CST+1. */ | |
2491 | if (! (hi_code == EQ_EXPR | |
2492 | && TREE_INT_CST_LOW (hi_cst) - TREE_INT_CST_LOW (lo_cst) == 1 | |
2493 | && tree_int_cst_equal (integer_one_node, | |
2494 | const_binop (MINUS_EXPR, | |
2495 | hi_cst, lo_cst)))) | |
2496 | return 0; | |
2497 | ||
2498 | rcode = LE_EXPR; | |
2499 | break; | |
2500 | ||
2501 | case LE_EXPR: | |
2502 | case LT_EXPR: | |
2503 | if (hi_code == GE_EXPR) | |
2504 | hi_cst = const_binop (MINUS_EXPR, hi_cst, integer_one_node); | |
2505 | else if (hi_code != GT_EXPR) | |
2506 | return 0; | |
2507 | ||
2508 | if (lo_code == LE_EXPR) | |
2509 | lo_cst = const_binop (PLUS_EXPR, lo_cst, integer_one_node); | |
2510 | ||
2511 | /* We now have VAR < LO_CST || VAR > HI_CST. */ | |
2512 | rcode = GT_EXPR; | |
2513 | break; | |
2514 | ||
2515 | default: | |
2516 | return 0; | |
2517 | } | |
2518 | } | |
2519 | ||
2520 | /* When normalizing, it is possible to both increment the smaller constant | |
2521 | and decrement the larger constant. See if they are still ordered. */ | |
f5902869 TW |
2522 | if (tree_int_cst_lt (hi_cst, lo_cst)) |
2523 | return 0; | |
2524 | ||
2525 | /* Fail if VAR isn't an integer. */ | |
2526 | utype = TREE_TYPE (var); | |
2527 | if (TREE_CODE (utype) != INTEGER_TYPE | |
2528 | && TREE_CODE (utype) != ENUMERAL_TYPE) | |
ef659ec0 TW |
2529 | return 0; |
2530 | ||
2531 | /* The range test is invalid if subtracting the two constants results | |
2532 | in overflow. This can happen in traditional mode. */ | |
2533 | if (! int_fits_type_p (hi_cst, TREE_TYPE (var)) | |
2534 | || ! int_fits_type_p (lo_cst, TREE_TYPE (var))) | |
2535 | return 0; | |
2536 | ||
ef659ec0 TW |
2537 | if (! TREE_UNSIGNED (utype)) |
2538 | { | |
2539 | utype = unsigned_type (utype); | |
2540 | var = convert (utype, var); | |
2541 | } | |
2542 | ||
2543 | return fold (convert (type, | |
2544 | build (rcode, utype, | |
2545 | build (MINUS_EXPR, utype, var, lo_cst), | |
2546 | const_binop (MINUS_EXPR, hi_cst, lo_cst)))); | |
2547 | } | |
2548 | \f | |
b2215d83 TW |
2549 | /* Find ways of folding logical expressions of LHS and RHS: |
2550 | Try to merge two comparisons to the same innermost item. | |
2551 | Look for range tests like "ch >= '0' && ch <= '9'". | |
2552 | Look for combinations of simple terms on machines with expensive branches | |
2553 | and evaluate the RHS unconditionally. | |
6d716ca8 RS |
2554 | |
2555 | For example, if we have p->a == 2 && p->b == 4 and we can make an | |
2556 | object large enough to span both A and B, we can do this with a comparison | |
2557 | against the object ANDed with the a mask. | |
2558 | ||
2559 | If we have p->a == q->a && p->b == q->b, we may be able to use bit masking | |
2560 | operations to do this with one comparison. | |
2561 | ||
2562 | We check for both normal comparisons and the BIT_AND_EXPRs made this by | |
2563 | function and the one above. | |
2564 | ||
2565 | CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR, | |
2566 | TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR. | |
2567 | ||
2568 | TRUTH_TYPE is the type of the logical operand and LHS and RHS are its | |
2569 | two operands. | |
2570 | ||
2571 | We return the simplified tree or 0 if no optimization is possible. */ | |
2572 | ||
2573 | static tree | |
b2215d83 | 2574 | fold_truthop (code, truth_type, lhs, rhs) |
6d716ca8 RS |
2575 | enum tree_code code; |
2576 | tree truth_type, lhs, rhs; | |
2577 | { | |
2578 | /* If this is the "or" of two comparisons, we can do something if we | |
2579 | the comparisons are NE_EXPR. If this is the "and", we can do something | |
2580 | if the comparisons are EQ_EXPR. I.e., | |
2581 | (a->b == 2 && a->c == 4) can become (a->new == NEW). | |
2582 | ||
2583 | WANTED_CODE is this operation code. For single bit fields, we can | |
2584 | convert EQ_EXPR to NE_EXPR so we need not reject the "wrong" | |
2585 | comparison for one-bit fields. */ | |
2586 | ||
b2215d83 | 2587 | enum tree_code wanted_code; |
6d716ca8 | 2588 | enum tree_code lcode, rcode; |
b2215d83 | 2589 | tree ll_arg, lr_arg, rl_arg, rr_arg; |
6d716ca8 RS |
2590 | tree ll_inner, lr_inner, rl_inner, rr_inner; |
2591 | int ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos; | |
2592 | int rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos; | |
2593 | int xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos; | |
2594 | int lnbitsize, lnbitpos, rnbitsize, rnbitpos; | |
2595 | int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp; | |
2596 | enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode; | |
2597 | enum machine_mode lnmode, rnmode; | |
2598 | tree ll_mask, lr_mask, rl_mask, rr_mask; | |
b2215d83 | 2599 | tree l_const, r_const; |
6d716ca8 RS |
2600 | tree type, result; |
2601 | int first_bit, end_bit; | |
b2215d83 | 2602 | int volatilep; |
6d716ca8 | 2603 | |
ef659ec0 TW |
2604 | /* Start by getting the comparison codes and seeing if this looks like |
2605 | a range test. Fail if anything is volatile. */ | |
6d716ca8 | 2606 | |
b2215d83 TW |
2607 | if (TREE_SIDE_EFFECTS (lhs) |
2608 | || TREE_SIDE_EFFECTS (rhs)) | |
2609 | return 0; | |
2610 | ||
6d716ca8 RS |
2611 | lcode = TREE_CODE (lhs); |
2612 | rcode = TREE_CODE (rhs); | |
ef659ec0 | 2613 | |
b2215d83 | 2614 | if (TREE_CODE_CLASS (lcode) != '<' |
ef659ec0 TW |
2615 | || TREE_CODE_CLASS (rcode) != '<') |
2616 | return 0; | |
2617 | ||
b2215d83 | 2618 | code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR) |
9c0ae98b | 2619 | ? TRUTH_AND_EXPR : TRUTH_OR_EXPR); |
b2215d83 TW |
2620 | |
2621 | ll_arg = TREE_OPERAND (lhs, 0); | |
2622 | lr_arg = TREE_OPERAND (lhs, 1); | |
2623 | rl_arg = TREE_OPERAND (rhs, 0); | |
2624 | rr_arg = TREE_OPERAND (rhs, 1); | |
2625 | ||
2626 | if (TREE_CODE (lr_arg) == INTEGER_CST | |
2627 | && TREE_CODE (rr_arg) == INTEGER_CST | |
2628 | && operand_equal_p (ll_arg, rl_arg, 0)) | |
ef659ec0 | 2629 | { |
b2215d83 | 2630 | if (tree_int_cst_lt (lr_arg, rr_arg)) |
ef659ec0 | 2631 | result = range_test (code, truth_type, lcode, rcode, |
b2215d83 | 2632 | ll_arg, lr_arg, rr_arg); |
ef659ec0 TW |
2633 | else |
2634 | result = range_test (code, truth_type, rcode, lcode, | |
b2215d83 | 2635 | ll_arg, rr_arg, lr_arg); |
ef659ec0 TW |
2636 | |
2637 | /* If this isn't a range test, it also isn't a comparison that | |
b2215d83 TW |
2638 | can be merged. However, it wins to evaluate the RHS unconditionally |
2639 | on machines with expensive branches. */ | |
2640 | ||
2641 | if (result == 0 && BRANCH_COST >= 2) | |
2642 | { | |
2643 | if (TREE_CODE (ll_arg) != VAR_DECL | |
2644 | && TREE_CODE (ll_arg) != PARM_DECL) | |
2645 | { | |
2646 | /* Avoid evaluating the variable part twice. */ | |
2647 | ll_arg = save_expr (ll_arg); | |
2648 | lhs = build (lcode, TREE_TYPE (lhs), ll_arg, lr_arg); | |
2649 | rhs = build (rcode, TREE_TYPE (rhs), ll_arg, rr_arg); | |
2650 | } | |
2651 | return build (code, truth_type, lhs, rhs); | |
2652 | } | |
ef659ec0 TW |
2653 | return result; |
2654 | } | |
2655 | ||
b2215d83 TW |
2656 | /* If the RHS can be evaluated unconditionally and all operands are |
2657 | simple, it wins to evaluate the RHS unconditionally on machines | |
2658 | with expensive branches. In this case, this isn't a comparison | |
2659 | that can be merged. */ | |
2660 | ||
2661 | /* @@ I'm not sure it wins on the m88110 to do this if the comparisons | |
2662 | are with zero (tmw). */ | |
2663 | ||
2664 | if (BRANCH_COST >= 2 | |
2665 | && TREE_CODE (TREE_TYPE (rhs)) == INTEGER_TYPE | |
2666 | && simple_operand_p (rl_arg) | |
2667 | && simple_operand_p (ll_arg) | |
2668 | && simple_operand_p (rr_arg) | |
2669 | && simple_operand_p (lr_arg)) | |
2670 | return build (code, truth_type, lhs, rhs); | |
2671 | ||
ef659ec0 TW |
2672 | /* See if the comparisons can be merged. Then get all the parameters for |
2673 | each side. */ | |
2674 | ||
6d716ca8 | 2675 | if ((lcode != EQ_EXPR && lcode != NE_EXPR) |
ef659ec0 | 2676 | || (rcode != EQ_EXPR && rcode != NE_EXPR)) |
6d716ca8 RS |
2677 | return 0; |
2678 | ||
b2215d83 TW |
2679 | volatilep = 0; |
2680 | ll_inner = decode_field_reference (ll_arg, | |
6d716ca8 RS |
2681 | &ll_bitsize, &ll_bitpos, &ll_mode, |
2682 | &ll_unsignedp, &volatilep, &ll_mask); | |
b2215d83 | 2683 | lr_inner = decode_field_reference (lr_arg, |
6d716ca8 RS |
2684 | &lr_bitsize, &lr_bitpos, &lr_mode, |
2685 | &lr_unsignedp, &volatilep, &lr_mask); | |
b2215d83 | 2686 | rl_inner = decode_field_reference (rl_arg, |
6d716ca8 RS |
2687 | &rl_bitsize, &rl_bitpos, &rl_mode, |
2688 | &rl_unsignedp, &volatilep, &rl_mask); | |
b2215d83 | 2689 | rr_inner = decode_field_reference (rr_arg, |
6d716ca8 RS |
2690 | &rr_bitsize, &rr_bitpos, &rr_mode, |
2691 | &rr_unsignedp, &volatilep, &rr_mask); | |
2692 | ||
2693 | /* It must be true that the inner operation on the lhs of each | |
2694 | comparison must be the same if we are to be able to do anything. | |
2695 | Then see if we have constants. If not, the same must be true for | |
2696 | the rhs's. */ | |
2697 | if (volatilep || ll_inner == 0 || rl_inner == 0 | |
2698 | || ! operand_equal_p (ll_inner, rl_inner, 0)) | |
2699 | return 0; | |
2700 | ||
b2215d83 TW |
2701 | if (TREE_CODE (lr_arg) == INTEGER_CST |
2702 | && TREE_CODE (rr_arg) == INTEGER_CST) | |
2703 | l_const = lr_arg, r_const = rr_arg; | |
6d716ca8 RS |
2704 | else if (lr_inner == 0 || rr_inner == 0 |
2705 | || ! operand_equal_p (lr_inner, rr_inner, 0)) | |
2706 | return 0; | |
b2215d83 TW |
2707 | else |
2708 | l_const = r_const = 0; | |
6d716ca8 RS |
2709 | |
2710 | /* If either comparison code is not correct for our logical operation, | |
2711 | fail. However, we can convert a one-bit comparison against zero into | |
2712 | the opposite comparison against that bit being set in the field. */ | |
b2215d83 | 2713 | |
9c0ae98b | 2714 | wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR); |
6d716ca8 RS |
2715 | if (lcode != wanted_code) |
2716 | { | |
2717 | if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask)) | |
2718 | l_const = ll_mask; | |
2719 | else | |
2720 | return 0; | |
2721 | } | |
2722 | ||
2723 | if (rcode != wanted_code) | |
2724 | { | |
2725 | if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask)) | |
2726 | r_const = rl_mask; | |
2727 | else | |
2728 | return 0; | |
2729 | } | |
2730 | ||
2731 | /* See if we can find a mode that contains both fields being compared on | |
2732 | the left. If we can't, fail. Otherwise, update all constants and masks | |
2733 | to be relative to a field of that size. */ | |
2734 | first_bit = MIN (ll_bitpos, rl_bitpos); | |
2735 | end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize); | |
2736 | lnmode = get_best_mode (end_bit - first_bit, first_bit, | |
2737 | TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode, | |
2738 | volatilep); | |
2739 | if (lnmode == VOIDmode) | |
2740 | return 0; | |
2741 | ||
2742 | lnbitsize = GET_MODE_BITSIZE (lnmode); | |
2743 | lnbitpos = first_bit & ~ (lnbitsize - 1); | |
2744 | type = type_for_size (lnbitsize, 1); | |
2745 | xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos; | |
2746 | ||
2747 | #if BYTES_BIG_ENDIAN | |
2748 | xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize; | |
2749 | xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize; | |
2750 | #endif | |
2751 | ||
2752 | ll_mask = const_binop (LSHIFT_EXPR, convert (type, ll_mask), | |
2753 | size_int (xll_bitpos)); | |
2754 | rl_mask = const_binop (LSHIFT_EXPR, convert (type, rl_mask), | |
2755 | size_int (xrl_bitpos)); | |
2756 | ||
2757 | /* Make sure the constants are interpreted as unsigned, so we | |
2758 | don't have sign bits outside the range of their type. */ | |
2759 | ||
2760 | if (l_const) | |
2761 | { | |
2762 | l_const = convert (unsigned_type (TREE_TYPE (l_const)), l_const); | |
2763 | l_const = const_binop (LSHIFT_EXPR, convert (type, l_const), | |
2764 | size_int (xll_bitpos)); | |
2765 | } | |
2766 | if (r_const) | |
2767 | { | |
2768 | r_const = convert (unsigned_type (TREE_TYPE (r_const)), r_const); | |
2769 | r_const = const_binop (LSHIFT_EXPR, convert (type, r_const), | |
2770 | size_int (xrl_bitpos)); | |
2771 | } | |
2772 | ||
2773 | /* If the right sides are not constant, do the same for it. Also, | |
2774 | disallow this optimization if a size or signedness mismatch occurs | |
2775 | between the left and right sides. */ | |
2776 | if (l_const == 0) | |
2777 | { | |
2778 | if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize | |
e6a28f26 RS |
2779 | || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp |
2780 | /* Make sure the two fields on the right | |
2781 | correspond to the left without being swapped. */ | |
2782 | || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos) | |
6d716ca8 RS |
2783 | return 0; |
2784 | ||
2785 | first_bit = MIN (lr_bitpos, rr_bitpos); | |
2786 | end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize); | |
2787 | rnmode = get_best_mode (end_bit - first_bit, first_bit, | |
2788 | TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode, | |
2789 | volatilep); | |
2790 | if (rnmode == VOIDmode) | |
2791 | return 0; | |
2792 | ||
2793 | rnbitsize = GET_MODE_BITSIZE (rnmode); | |
2794 | rnbitpos = first_bit & ~ (rnbitsize - 1); | |
2795 | xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos; | |
2796 | ||
2797 | #if BYTES_BIG_ENDIAN | |
2798 | xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize; | |
2799 | xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize; | |
2800 | #endif | |
2801 | ||
2802 | lr_mask = const_binop (LSHIFT_EXPR, convert (type, lr_mask), | |
2803 | size_int (xlr_bitpos)); | |
2804 | rr_mask = const_binop (LSHIFT_EXPR, convert (type, rr_mask), | |
2805 | size_int (xrr_bitpos)); | |
2806 | ||
2807 | /* Make a mask that corresponds to both fields being compared. | |
2808 | Do this for both items being compared. If the masks agree, | |
2809 | we can do this by masking both and comparing the masked | |
2810 | results. */ | |
2811 | ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask); | |
2812 | lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask); | |
2813 | if (operand_equal_p (ll_mask, lr_mask, 0) && lnbitsize == rnbitsize) | |
2814 | { | |
2815 | lhs = make_bit_field_ref (ll_inner, type, lnbitsize, lnbitpos, | |
2816 | ll_unsignedp || rl_unsignedp); | |
2817 | rhs = make_bit_field_ref (lr_inner, type, rnbitsize, rnbitpos, | |
2818 | lr_unsignedp || rr_unsignedp); | |
2819 | if (! all_ones_mask_p (ll_mask, lnbitsize)) | |
2820 | { | |
2821 | lhs = build (BIT_AND_EXPR, type, lhs, ll_mask); | |
2822 | rhs = build (BIT_AND_EXPR, type, rhs, ll_mask); | |
2823 | } | |
2824 | return build (wanted_code, truth_type, lhs, rhs); | |
2825 | } | |
2826 | ||
2827 | /* There is still another way we can do something: If both pairs of | |
2828 | fields being compared are adjacent, we may be able to make a wider | |
2829 | field containing them both. */ | |
2830 | if ((ll_bitsize + ll_bitpos == rl_bitpos | |
2831 | && lr_bitsize + lr_bitpos == rr_bitpos) | |
2832 | || (ll_bitpos == rl_bitpos + rl_bitsize | |
2833 | && lr_bitpos == rr_bitpos + rr_bitsize)) | |
2834 | return build (wanted_code, truth_type, | |
2835 | make_bit_field_ref (ll_inner, type, | |
2836 | ll_bitsize + rl_bitsize, | |
2837 | MIN (ll_bitpos, rl_bitpos), | |
2838 | ll_unsignedp), | |
2839 | make_bit_field_ref (lr_inner, type, | |
2840 | lr_bitsize + rr_bitsize, | |
2841 | MIN (lr_bitpos, rr_bitpos), | |
2842 | lr_unsignedp)); | |
2843 | ||
2844 | return 0; | |
2845 | } | |
2846 | ||
2847 | /* Handle the case of comparisons with constants. If there is something in | |
2848 | common between the masks, those bits of the constants must be the same. | |
2849 | If not, the condition is always false. Test for this to avoid generating | |
2850 | incorrect code below. */ | |
2851 | result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask); | |
2852 | if (! integer_zerop (result) | |
2853 | && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const), | |
2854 | const_binop (BIT_AND_EXPR, result, r_const)) != 1) | |
2855 | { | |
2856 | if (wanted_code == NE_EXPR) | |
2857 | { | |
2858 | warning ("`or' of unmatched not-equal tests is always 1"); | |
2859 | return convert (truth_type, integer_one_node); | |
2860 | } | |
2861 | else | |
2862 | { | |
2863 | warning ("`and' of mutually exclusive equal-tests is always zero"); | |
2864 | return convert (truth_type, integer_zero_node); | |
2865 | } | |
2866 | } | |
2867 | ||
2868 | /* Construct the expression we will return. First get the component | |
2869 | reference we will make. Unless the mask is all ones the width of | |
2870 | that field, perform the mask operation. Then compare with the | |
2871 | merged constant. */ | |
2872 | result = make_bit_field_ref (ll_inner, type, lnbitsize, lnbitpos, | |
2873 | ll_unsignedp || rl_unsignedp); | |
2874 | ||
2875 | ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask); | |
2876 | if (! all_ones_mask_p (ll_mask, lnbitsize)) | |
2877 | result = build (BIT_AND_EXPR, type, result, ll_mask); | |
2878 | ||
2879 | return build (wanted_code, truth_type, result, | |
2880 | const_binop (BIT_IOR_EXPR, l_const, r_const)); | |
2881 | } | |
2882 | \f | |
2883 | /* Perform constant folding and related simplification of EXPR. | |
2884 | The related simplifications include x*1 => x, x*0 => 0, etc., | |
2885 | and application of the associative law. | |
2886 | NOP_EXPR conversions may be removed freely (as long as we | |
2887 | are careful not to change the C type of the overall expression) | |
2888 | We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR, | |
2889 | but we can constant-fold them if they have constant operands. */ | |
2890 | ||
2891 | tree | |
2892 | fold (expr) | |
2893 | tree expr; | |
2894 | { | |
2895 | register tree t = expr; | |
2896 | tree t1 = NULL_TREE; | |
c05a9b68 | 2897 | tree tem; |
6d716ca8 RS |
2898 | tree type = TREE_TYPE (expr); |
2899 | register tree arg0, arg1; | |
2900 | register enum tree_code code = TREE_CODE (t); | |
2901 | register int kind; | |
c05a9b68 | 2902 | int invert; |
6d716ca8 RS |
2903 | |
2904 | /* WINS will be nonzero when the switch is done | |
2905 | if all operands are constant. */ | |
2906 | ||
2907 | int wins = 1; | |
2908 | ||
2909 | /* Return right away if already constant. */ | |
2910 | if (TREE_CONSTANT (t)) | |
2911 | { | |
2912 | if (code == CONST_DECL) | |
2913 | return DECL_INITIAL (t); | |
2914 | return t; | |
2915 | } | |
2916 | ||
2917 | kind = TREE_CODE_CLASS (code); | |
1b81aa14 RS |
2918 | if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR) |
2919 | { | |
2920 | /* Special case for conversion ops that can have fixed point args. */ | |
2921 | arg0 = TREE_OPERAND (t, 0); | |
2922 | ||
2923 | /* Don't use STRIP_NOPS, because signedness of argument type matters. */ | |
2924 | if (arg0 != 0) | |
2925 | STRIP_TYPE_NOPS (arg0); | |
2926 | ||
2927 | if (arg0 != 0 && TREE_CODE (arg0) != INTEGER_CST | |
2928 | #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) | |
2929 | && TREE_CODE (arg0) != REAL_CST | |
2930 | #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */ | |
2931 | ) | |
2932 | /* Note that TREE_CONSTANT isn't enough: | |
2933 | static var addresses are constant but we can't | |
2934 | do arithmetic on them. */ | |
2935 | wins = 0; | |
2936 | } | |
2937 | else if (kind == 'e' || kind == '<' | |
2938 | || kind == '1' || kind == '2' || kind == 'r') | |
6d716ca8 RS |
2939 | { |
2940 | register int len = tree_code_length[(int) code]; | |
2941 | register int i; | |
2942 | for (i = 0; i < len; i++) | |
2943 | { | |
2944 | tree op = TREE_OPERAND (t, i); | |
2945 | ||
2946 | if (op == 0) | |
2947 | continue; /* Valid for CALL_EXPR, at least. */ | |
2948 | ||
2949 | /* Strip any conversions that don't change the mode. */ | |
2950 | STRIP_NOPS (op); | |
2951 | ||
2952 | if (TREE_CODE (op) != INTEGER_CST | |
2953 | #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) | |
2954 | && TREE_CODE (op) != REAL_CST | |
2955 | #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */ | |
2956 | ) | |
2957 | /* Note that TREE_CONSTANT isn't enough: | |
2958 | static var addresses are constant but we can't | |
2959 | do arithmetic on them. */ | |
2960 | wins = 0; | |
2961 | ||
2962 | if (i == 0) | |
2963 | arg0 = op; | |
2964 | else if (i == 1) | |
2965 | arg1 = op; | |
2966 | } | |
2967 | } | |
2968 | ||
2969 | /* If this is a commutative operation, and ARG0 is a constant, move it | |
2970 | to ARG1 to reduce the number of tests below. */ | |
2971 | if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR | |
2972 | || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR | |
2973 | || code == BIT_AND_EXPR) | |
2974 | && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)) | |
2975 | { | |
c05a9b68 | 2976 | tem = arg0; arg0 = arg1; arg1 = tem; |
6d716ca8 | 2977 | |
c05a9b68 RS |
2978 | tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1); |
2979 | TREE_OPERAND (t, 1) = tem; | |
6d716ca8 RS |
2980 | } |
2981 | ||
2982 | /* Now WINS is set as described above, | |
2983 | ARG0 is the first operand of EXPR, | |
2984 | and ARG1 is the second operand (if it has more than one operand). | |
2985 | ||
2986 | First check for cases where an arithmetic operation is applied to a | |
2987 | compound, conditional, or comparison operation. Push the arithmetic | |
2988 | operation inside the compound or conditional to see if any folding | |
2989 | can then be done. Convert comparison to conditional for this purpose. | |
2990 | The also optimizes non-constant cases that used to be done in | |
2991 | expand_expr. */ | |
2992 | if (TREE_CODE_CLASS (code) == '1') | |
2993 | { | |
2994 | if (TREE_CODE (arg0) == COMPOUND_EXPR) | |
2995 | return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0), | |
2996 | fold (build1 (code, type, TREE_OPERAND (arg0, 1)))); | |
2997 | else if (TREE_CODE (arg0) == COND_EXPR) | |
b8eb43a2 RK |
2998 | { |
2999 | t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0), | |
3000 | fold (build1 (code, type, TREE_OPERAND (arg0, 1))), | |
3001 | fold (build1 (code, type, TREE_OPERAND (arg0, 2))))); | |
3002 | ||
3003 | /* If this was a conversion, and all we did was to move into | |
3004 | inside the COND_EXPR, bring it back out. Then return so we | |
3005 | don't get into an infinite recursion loop taking the conversion | |
3006 | out and then back in. */ | |
3007 | ||
3008 | if ((code == NOP_EXPR || code == CONVERT_EXPR | |
3009 | || code == NON_LVALUE_EXPR) | |
3010 | && TREE_CODE (t) == COND_EXPR | |
3011 | && TREE_CODE (TREE_OPERAND (t, 1)) == code | |
3012 | && TREE_CODE (TREE_OPERAND (t, 2)) == code) | |
3013 | t = build1 (code, type, | |
3014 | build (COND_EXPR, | |
3015 | TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0)), | |
3016 | TREE_OPERAND (t, 0), | |
3017 | TREE_OPERAND (TREE_OPERAND (t, 1), 0), | |
3018 | TREE_OPERAND (TREE_OPERAND (t, 2), 0))); | |
3019 | return t; | |
3020 | } | |
6d716ca8 RS |
3021 | else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<') |
3022 | return fold (build (COND_EXPR, type, arg0, | |
3023 | fold (build1 (code, type, integer_one_node)), | |
3024 | fold (build1 (code, type, integer_zero_node)))); | |
3025 | } | |
3026 | else if (TREE_CODE_CLASS (code) == '2') | |
3027 | { | |
3028 | if (TREE_CODE (arg1) == COMPOUND_EXPR) | |
3029 | return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0), | |
3030 | fold (build (code, type, arg0, TREE_OPERAND (arg1, 1)))); | |
3031 | else if (TREE_CODE (arg1) == COND_EXPR | |
3032 | || TREE_CODE_CLASS (TREE_CODE (arg1)) == '<') | |
3033 | { | |
3034 | tree test, true_value, false_value; | |
3035 | ||
3036 | if (TREE_CODE (arg1) == COND_EXPR) | |
3037 | { | |
3038 | test = TREE_OPERAND (arg1, 0); | |
3039 | true_value = TREE_OPERAND (arg1, 1); | |
3040 | false_value = TREE_OPERAND (arg1, 2); | |
3041 | } | |
3042 | else | |
3043 | { | |
3044 | test = arg1; | |
3045 | true_value = integer_one_node; | |
3046 | false_value = integer_zero_node; | |
3047 | } | |
3048 | ||
3049 | if (TREE_CODE (arg0) != VAR_DECL && TREE_CODE (arg0) != PARM_DECL) | |
3050 | arg0 = save_expr (arg0); | |
3051 | test = fold (build (COND_EXPR, type, test, | |
3052 | fold (build (code, type, arg0, true_value)), | |
3053 | fold (build (code, type, arg0, false_value)))); | |
3054 | if (TREE_CODE (arg0) == SAVE_EXPR) | |
3055 | return build (COMPOUND_EXPR, type, | |
3056 | convert (void_type_node, arg0), test); | |
3057 | else | |
3058 | return convert (type, test); | |
3059 | } | |
3060 | ||
3061 | else if (TREE_CODE (arg0) == COMPOUND_EXPR) | |
3062 | return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0), | |
3063 | fold (build (code, type, TREE_OPERAND (arg0, 1), arg1))); | |
3064 | else if (TREE_CODE (arg0) == COND_EXPR | |
3065 | || TREE_CODE_CLASS (TREE_CODE (arg0)) == '<') | |
3066 | { | |
3067 | tree test, true_value, false_value; | |
3068 | ||
3069 | if (TREE_CODE (arg0) == COND_EXPR) | |
3070 | { | |
3071 | test = TREE_OPERAND (arg0, 0); | |
3072 | true_value = TREE_OPERAND (arg0, 1); | |
3073 | false_value = TREE_OPERAND (arg0, 2); | |
3074 | } | |
3075 | else | |
3076 | { | |
3077 | test = arg0; | |
3078 | true_value = integer_one_node; | |
3079 | false_value = integer_zero_node; | |
3080 | } | |
3081 | ||
3082 | if (TREE_CODE (arg1) != VAR_DECL && TREE_CODE (arg1) != PARM_DECL) | |
3083 | arg1 = save_expr (arg1); | |
3084 | test = fold (build (COND_EXPR, type, test, | |
3085 | fold (build (code, type, true_value, arg1)), | |
3086 | fold (build (code, type, false_value, arg1)))); | |
3087 | if (TREE_CODE (arg1) == SAVE_EXPR) | |
3088 | return build (COMPOUND_EXPR, type, | |
3089 | convert (void_type_node, arg1), test); | |
3090 | else | |
3091 | return convert (type, test); | |
3092 | } | |
3093 | } | |
c05a9b68 RS |
3094 | else if (TREE_CODE_CLASS (code) == '<' |
3095 | && TREE_CODE (arg0) == COMPOUND_EXPR) | |
3096 | return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0), | |
3097 | fold (build (code, type, TREE_OPERAND (arg0, 1), arg1))); | |
3098 | else if (TREE_CODE_CLASS (code) == '<' | |
3099 | && TREE_CODE (arg1) == COMPOUND_EXPR) | |
3100 | return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0), | |
3101 | fold (build (code, type, arg0, TREE_OPERAND (arg1, 1)))); | |
6d716ca8 RS |
3102 | |
3103 | switch (code) | |
3104 | { | |
3105 | case INTEGER_CST: | |
3106 | case REAL_CST: | |
3107 | case STRING_CST: | |
3108 | case COMPLEX_CST: | |
3109 | case CONSTRUCTOR: | |
3110 | return t; | |
3111 | ||
3112 | case CONST_DECL: | |
3113 | return fold (DECL_INITIAL (t)); | |
3114 | ||
3115 | case NOP_EXPR: | |
3116 | case FLOAT_EXPR: | |
3117 | case CONVERT_EXPR: | |
3118 | case FIX_TRUNC_EXPR: | |
3119 | /* Other kinds of FIX are not handled properly by fold_convert. */ | |
3120 | /* Two conversions in a row are not needed unless: | |
3121 | - the intermediate type is narrower than both initial and final, or | |
68d88491 RS |
3122 | - the intermediate type and innermost type differ in signedness, |
3123 | and the outermost type is wider than the intermediate, or | |
6d716ca8 RS |
3124 | - the initial type is a pointer type and the precisions of the |
3125 | intermediate and final types differ, or | |
3126 | - the final type is a pointer type and the precisions of the | |
3127 | initial and intermediate types differ. */ | |
3128 | if ((TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR | |
3129 | || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR) | |
3130 | && (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t, 0))) | |
3131 | > TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))) | |
3132 | || | |
3133 | TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t, 0))) | |
3134 | > TYPE_PRECISION (TREE_TYPE (t))) | |
68d88491 RS |
3135 | && ! ((TREE_CODE (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))) |
3136 | == INTEGER_TYPE) | |
3137 | && (TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) | |
3138 | == INTEGER_TYPE) | |
3139 | && (TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (t, 0))) | |
3140 | != TREE_UNSIGNED (TREE_OPERAND (TREE_OPERAND (t, 0), 0))) | |
3141 | && (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t, 0))) | |
3142 | < TYPE_PRECISION (TREE_TYPE (t)))) | |
6d716ca8 RS |
3143 | && ((TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (t, 0))) |
3144 | && (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t, 0))) | |
3145 | > TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))))) | |
3146 | == | |
3147 | (TREE_UNSIGNED (TREE_TYPE (t)) | |
3148 | && (TYPE_PRECISION (TREE_TYPE (t)) | |
3149 | > TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t, 0)))))) | |
3150 | && ! ((TREE_CODE (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))) | |
3151 | == POINTER_TYPE) | |
3152 | && (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t, 0))) | |
3153 | != TYPE_PRECISION (TREE_TYPE (t)))) | |
3154 | && ! (TREE_CODE (TREE_TYPE (t)) == POINTER_TYPE | |
3155 | && (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))) | |
3156 | != TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t, 0)))))) | |
3157 | return convert (TREE_TYPE (t), TREE_OPERAND (TREE_OPERAND (t, 0), 0)); | |
3158 | ||
3159 | if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR | |
d8f6dbb9 RS |
3160 | && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) |
3161 | /* Detect assigning a bitfield. */ | |
3162 | && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF | |
3163 | && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1)))) | |
6d716ca8 | 3164 | { |
d8f6dbb9 | 3165 | /* Don't leave an assignment inside a conversion |
f72aed24 | 3166 | unless assigning a bitfield. */ |
6d716ca8 RS |
3167 | tree prev = TREE_OPERAND (t, 0); |
3168 | TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1); | |
3169 | /* First do the assignment, then return converted constant. */ | |
3170 | t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t)); | |
3171 | TREE_USED (t) = 1; | |
3172 | return t; | |
3173 | } | |
3174 | if (!wins) | |
3175 | { | |
3176 | TREE_CONSTANT (t) = TREE_CONSTANT (arg0); | |
3177 | return t; | |
3178 | } | |
3179 | return fold_convert (t, arg0); | |
3180 | ||
3181 | #if 0 /* This loses on &"foo"[0]. */ | |
3182 | case ARRAY_REF: | |
3183 | { | |
3184 | int i; | |
3185 | ||
3186 | /* Fold an expression like: "foo"[2] */ | |
3187 | if (TREE_CODE (arg0) == STRING_CST | |
3188 | && TREE_CODE (arg1) == INTEGER_CST | |
3189 | && !TREE_INT_CST_HIGH (arg1) | |
3190 | && (i = TREE_INT_CST_LOW (arg1)) < TREE_STRING_LENGTH (arg0)) | |
3191 | { | |
3192 | t = build_int_2 (TREE_STRING_POINTER (arg0)[i], 0); | |
3193 | TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (arg0)); | |
3194 | force_fit_type (t); | |
3195 | } | |
3196 | } | |
3197 | return t; | |
3198 | #endif /* 0 */ | |
3199 | ||
3200 | case RANGE_EXPR: | |
3201 | TREE_CONSTANT (t) = wins; | |
3202 | return t; | |
3203 | ||
3204 | case NEGATE_EXPR: | |
3205 | if (wins) | |
3206 | { | |
3207 | if (TREE_CODE (arg0) == INTEGER_CST) | |
3208 | { | |
fe3e8e40 RS |
3209 | HOST_WIDE_INT low, high; |
3210 | int overflow = neg_double (TREE_INT_CST_LOW (arg0), | |
3211 | TREE_INT_CST_HIGH (arg0), | |
3212 | &low, &high); | |
3213 | t = build_int_2 (low, high); | |
3214 | TREE_CONSTANT_OVERFLOW (t) | |
3215 | = overflow | TREE_CONSTANT_OVERFLOW (arg0); | |
6d716ca8 RS |
3216 | TREE_TYPE (t) = type; |
3217 | force_fit_type (t); | |
3218 | } | |
3219 | else if (TREE_CODE (arg0) == REAL_CST) | |
3220 | t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0))); | |
3221 | TREE_TYPE (t) = type; | |
3222 | } | |
3223 | else if (TREE_CODE (arg0) == NEGATE_EXPR) | |
3224 | return TREE_OPERAND (arg0, 0); | |
3225 | ||
3226 | /* Convert - (a - b) to (b - a) for non-floating-point. */ | |
3227 | else if (TREE_CODE (arg0) == MINUS_EXPR && TREE_CODE (type) != REAL_TYPE) | |
3228 | return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1), | |
3229 | TREE_OPERAND (arg0, 0)); | |
3230 | ||
3231 | return t; | |
3232 | ||
3233 | case ABS_EXPR: | |
3234 | if (wins) | |
3235 | { | |
3236 | if (TREE_CODE (arg0) == INTEGER_CST) | |
3237 | { | |
3238 | if (! TREE_UNSIGNED (type) | |
3239 | && TREE_INT_CST_HIGH (arg0) < 0) | |
3240 | { | |
3241 | if (TREE_INT_CST_LOW (arg0) == 0) | |
3242 | t = build_int_2 (0, - TREE_INT_CST_HIGH (arg0)); | |
3243 | else | |
3244 | t = build_int_2 (- TREE_INT_CST_LOW (arg0), | |
3245 | ~ TREE_INT_CST_HIGH (arg0)); | |
3246 | } | |
3247 | } | |
3248 | else if (TREE_CODE (arg0) == REAL_CST) | |
3249 | { | |
c05a9b68 | 3250 | if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0))) |
6d716ca8 RS |
3251 | t = build_real (type, |
3252 | REAL_VALUE_NEGATE (TREE_REAL_CST (arg0))); | |
3253 | } | |
3254 | TREE_TYPE (t) = type; | |
3255 | } | |
3256 | else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR) | |
3257 | return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)); | |
3258 | return t; | |
3259 | ||
3260 | case BIT_NOT_EXPR: | |
3261 | if (wins) | |
3262 | { | |
3263 | if (TREE_CODE (arg0) == INTEGER_CST) | |
3264 | t = build_int_2 (~ TREE_INT_CST_LOW (arg0), | |
3265 | ~ TREE_INT_CST_HIGH (arg0)); | |
3266 | TREE_TYPE (t) = type; | |
3267 | force_fit_type (t); | |
fe3e8e40 | 3268 | TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0); |
6d716ca8 RS |
3269 | } |
3270 | else if (TREE_CODE (arg0) == BIT_NOT_EXPR) | |
3271 | return TREE_OPERAND (arg0, 0); | |
3272 | return t; | |
3273 | ||
3274 | case PLUS_EXPR: | |
3275 | /* A + (-B) -> A - B */ | |
3276 | if (TREE_CODE (arg1) == NEGATE_EXPR) | |
3277 | return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0))); | |
3278 | else if (TREE_CODE (type) != REAL_TYPE) | |
3279 | { | |
3280 | if (integer_zerop (arg1)) | |
3281 | return non_lvalue (convert (type, arg0)); | |
3282 | ||
3283 | /* If we are adding two BIT_AND_EXPR's, both of which are and'ing | |
3284 | with a constant, and the two constants have no bits in common, | |
3285 | we should treat this as a BIT_IOR_EXPR since this may produce more | |
3286 | simplifications. */ | |
3287 | if (TREE_CODE (arg0) == BIT_AND_EXPR | |
3288 | && TREE_CODE (arg1) == BIT_AND_EXPR | |
3289 | && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST | |
3290 | && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST | |
3291 | && integer_zerop (const_binop (BIT_AND_EXPR, | |
3292 | TREE_OPERAND (arg0, 1), | |
3293 | TREE_OPERAND (arg1, 1)))) | |
3294 | { | |
3295 | code = BIT_IOR_EXPR; | |
3296 | goto bit_ior; | |
3297 | } | |
3298 | } | |
3299 | /* In IEEE floating point, x+0 may not equal x. */ | |
3300 | else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT | |
3301 | && real_zerop (arg1)) | |
3302 | return non_lvalue (convert (type, arg0)); | |
3303 | associate: | |
3304 | /* In most languages, can't associate operations on floats | |
3305 | through parentheses. Rather than remember where the parentheses | |
3306 | were, we don't associate floats at all. It shouldn't matter much. */ | |
3307 | if (TREE_CODE (type) == REAL_TYPE) | |
3308 | goto binary; | |
3309 | /* The varsign == -1 cases happen only for addition and subtraction. | |
3310 | It says that the arg that was split was really CON minus VAR. | |
3311 | The rest of the code applies to all associative operations. */ | |
3312 | if (!wins) | |
3313 | { | |
c05a9b68 | 3314 | tree var, con; |
6d716ca8 RS |
3315 | int varsign; |
3316 | ||
3317 | if (split_tree (arg0, code, &var, &con, &varsign)) | |
3318 | { | |
3319 | if (varsign == -1) | |
3320 | { | |
3321 | /* EXPR is (CON-VAR) +- ARG1. */ | |
3322 | /* If it is + and VAR==ARG1, return just CONST. */ | |
3323 | if (code == PLUS_EXPR && operand_equal_p (var, arg1, 0)) | |
3324 | return convert (TREE_TYPE (t), con); | |
3325 | ||
3326 | /* Otherwise return (CON +- ARG1) - VAR. */ | |
3327 | TREE_SET_CODE (t, MINUS_EXPR); | |
3328 | TREE_OPERAND (t, 1) = var; | |
3329 | TREE_OPERAND (t, 0) | |
3330 | = fold (build (code, TREE_TYPE (t), con, arg1)); | |
3331 | } | |
3332 | else | |
3333 | { | |
3334 | /* EXPR is (VAR+CON) +- ARG1. */ | |
3335 | /* If it is - and VAR==ARG1, return just CONST. */ | |
3336 | if (code == MINUS_EXPR && operand_equal_p (var, arg1, 0)) | |
3337 | return convert (TREE_TYPE (t), con); | |
3338 | ||
3339 | /* Otherwise return VAR +- (ARG1 +- CON). */ | |
3340 | TREE_OPERAND (t, 1) = tem | |
3341 | = fold (build (code, TREE_TYPE (t), arg1, con)); | |
3342 | TREE_OPERAND (t, 0) = var; | |
3343 | if (integer_zerop (tem) | |
3344 | && (code == PLUS_EXPR || code == MINUS_EXPR)) | |
3345 | return convert (type, var); | |
3346 | /* If we have x +/- (c - d) [c an explicit integer] | |
3347 | change it to x -/+ (d - c) since if d is relocatable | |
3348 | then the latter can be a single immediate insn | |
3349 | and the former cannot. */ | |
3350 | if (TREE_CODE (tem) == MINUS_EXPR | |
3351 | && TREE_CODE (TREE_OPERAND (tem, 0)) == INTEGER_CST) | |
3352 | { | |
3353 | tree tem1 = TREE_OPERAND (tem, 1); | |
3354 | TREE_OPERAND (tem, 1) = TREE_OPERAND (tem, 0); | |
3355 | TREE_OPERAND (tem, 0) = tem1; | |
3356 | TREE_SET_CODE (t, | |
3357 | (code == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR)); | |
3358 | } | |
3359 | } | |
3360 | return t; | |
3361 | } | |
3362 | ||
3363 | if (split_tree (arg1, code, &var, &con, &varsign)) | |
3364 | { | |
3365 | /* EXPR is ARG0 +- (CON +- VAR). */ | |
3366 | if (varsign == -1) | |
3367 | TREE_SET_CODE (t, | |
3368 | (code == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR)); | |
3369 | if (TREE_CODE (t) == MINUS_EXPR | |
3370 | && operand_equal_p (var, arg0, 0)) | |
3371 | { | |
3372 | /* If VAR and ARG0 cancel, return just CON or -CON. */ | |
3373 | if (code == PLUS_EXPR) | |
3374 | return convert (TREE_TYPE (t), con); | |
3375 | return fold (build1 (NEGATE_EXPR, TREE_TYPE (t), | |
3376 | convert (TREE_TYPE (t), con))); | |
3377 | } | |
3378 | TREE_OPERAND (t, 0) | |
3379 | = fold (build (code, TREE_TYPE (t), arg0, con)); | |
3380 | TREE_OPERAND (t, 1) = var; | |
3381 | if (integer_zerop (TREE_OPERAND (t, 0)) | |
3382 | && TREE_CODE (t) == PLUS_EXPR) | |
3383 | return convert (TREE_TYPE (t), var); | |
3384 | return t; | |
3385 | } | |
3386 | } | |
3387 | binary: | |
3388 | #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC) | |
3389 | if (TREE_CODE (arg1) == REAL_CST) | |
3390 | return t; | |
3391 | #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */ | |
3392 | if (wins) | |
3393 | t1 = const_binop (code, arg0, arg1); | |
3394 | if (t1 != NULL_TREE) | |
3395 | { | |
3396 | /* The return value should always have | |
3397 | the same type as the original expression. */ | |
3398 | TREE_TYPE (t1) = TREE_TYPE (t); | |
3399 | return t1; | |
3400 | } | |
3401 | return t; | |
3402 | ||
3403 | case MINUS_EXPR: | |
3404 | if (TREE_CODE (type) != REAL_TYPE) | |
3405 | { | |
3406 | if (! wins && integer_zerop (arg0)) | |
3407 | return build1 (NEGATE_EXPR, type, arg1); | |
3408 | if (integer_zerop (arg1)) | |
3409 | return non_lvalue (convert (type, arg0)); | |
3410 | } | |
3411 | /* Convert A - (-B) to A + B. */ | |
3412 | else if (TREE_CODE (arg1) == NEGATE_EXPR) | |
3413 | return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0))); | |
c05a9b68 | 3414 | else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT) |
6d716ca8 | 3415 | { |
c05a9b68 | 3416 | /* Except with IEEE floating point, 0-x equals -x. */ |
6d716ca8 RS |
3417 | if (! wins && real_zerop (arg0)) |
3418 | return build1 (NEGATE_EXPR, type, arg1); | |
c05a9b68 RS |
3419 | /* Except with IEEE floating point, x-0 equals x. */ |
3420 | if (real_zerop (arg1)) | |
6d716ca8 | 3421 | return non_lvalue (convert (type, arg0)); |
a6acbe15 RS |
3422 | |
3423 | /* Fold &x - &x. This can happen from &x.foo - &x. | |
3424 | This is unsafe for certain floats even in non-IEEE formats. | |
3425 | In IEEE, it is unsafe because it does wrong for NaNs. | |
6a1746af | 3426 | Also note that operand_equal_p is always false if an operand |
a6acbe15 RS |
3427 | is volatile. */ |
3428 | ||
3429 | if (operand_equal_p (arg0, arg1, | |
3430 | TREE_CODE (type) == REAL_TYPE)) | |
3431 | return convert (type, integer_zero_node); | |
6d716ca8 | 3432 | } |
6d716ca8 RS |
3433 | goto associate; |
3434 | ||
3435 | case MULT_EXPR: | |
3436 | if (TREE_CODE (type) != REAL_TYPE) | |
3437 | { | |
3438 | if (integer_zerop (arg1)) | |
3439 | return omit_one_operand (type, arg1, arg0); | |
3440 | if (integer_onep (arg1)) | |
3441 | return non_lvalue (convert (type, arg0)); | |
3442 | ||
3443 | /* (a * (1 << b)) is (a << b) */ | |
3444 | if (TREE_CODE (arg1) == LSHIFT_EXPR | |
3445 | && integer_onep (TREE_OPERAND (arg1, 0))) | |
3446 | return fold (build (LSHIFT_EXPR, type, arg0, | |
3447 | TREE_OPERAND (arg1, 1))); | |
3448 | if (TREE_CODE (arg0) == LSHIFT_EXPR | |
3449 | && integer_onep (TREE_OPERAND (arg0, 0))) | |
3450 | return fold (build (LSHIFT_EXPR, type, arg1, | |
3451 | TREE_OPERAND (arg0, 1))); | |
3452 | } | |
6d716ca8 RS |
3453 | else |
3454 | { | |
c05a9b68 | 3455 | /* x*0 is 0, except for IEEE floating point. */ |
6d716ca8 RS |
3456 | if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT |
3457 | && real_zerop (arg1)) | |
3458 | return omit_one_operand (type, arg1, arg0); | |
c05a9b68 | 3459 | /* In IEEE floating point, x*1 is not equivalent to x for snans. |
6d716ca8 RS |
3460 | However, ANSI says we can drop signals, |
3461 | so we can do this anyway. */ | |
3462 | if (real_onep (arg1)) | |
3463 | return non_lvalue (convert (type, arg0)); | |
3464 | /* x*2 is x+x */ | |
3465 | if (! wins && real_twop (arg1)) | |
3466 | { | |
3467 | tree arg = save_expr (arg0); | |
3468 | return build (PLUS_EXPR, type, arg, arg); | |
3469 | } | |
3470 | } | |
3471 | goto associate; | |
3472 | ||
3473 | case BIT_IOR_EXPR: | |
3474 | bit_ior: | |
3475 | if (integer_all_onesp (arg1)) | |
3476 | return omit_one_operand (type, arg1, arg0); | |
3477 | if (integer_zerop (arg1)) | |
3478 | return non_lvalue (convert (type, arg0)); | |
3479 | t1 = distribute_bit_expr (code, type, arg0, arg1); | |
3480 | if (t1 != NULL_TREE) | |
3481 | return t1; | |
3482 | goto associate; | |
3483 | ||
3484 | case BIT_XOR_EXPR: | |
3485 | if (integer_zerop (arg1)) | |
3486 | return non_lvalue (convert (type, arg0)); | |
3487 | if (integer_all_onesp (arg1)) | |
3488 | return fold (build1 (BIT_NOT_EXPR, type, arg0)); | |
3489 | goto associate; | |
3490 | ||
3491 | case BIT_AND_EXPR: | |
3492 | bit_and: | |
3493 | if (integer_all_onesp (arg1)) | |
3494 | return non_lvalue (convert (type, arg0)); | |
3495 | if (integer_zerop (arg1)) | |
3496 | return omit_one_operand (type, arg1, arg0); | |
3497 | t1 = distribute_bit_expr (code, type, arg0, arg1); | |
3498 | if (t1 != NULL_TREE) | |
3499 | return t1; | |
3500 | /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */ | |
3501 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == NOP_EXPR | |
3502 | && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0)))) | |
3503 | { | |
3504 | int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0))); | |
906c4e36 RK |
3505 | if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT |
3506 | && (~TREE_INT_CST_LOW (arg0) | |
3507 | & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0) | |
6d716ca8 RS |
3508 | return build1 (NOP_EXPR, type, TREE_OPERAND (arg1, 0)); |
3509 | } | |
3510 | if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR | |
3511 | && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0)))) | |
3512 | { | |
3513 | int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))); | |
906c4e36 RK |
3514 | if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT |
3515 | && (~TREE_INT_CST_LOW (arg1) | |
3516 | & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0) | |
6d716ca8 RS |
3517 | return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0)); |
3518 | } | |
3519 | goto associate; | |
3520 | ||
3521 | case BIT_ANDTC_EXPR: | |
3522 | if (integer_all_onesp (arg0)) | |
3523 | return non_lvalue (convert (type, arg1)); | |
3524 | if (integer_zerop (arg0)) | |
3525 | return omit_one_operand (type, arg0, arg1); | |
3526 | if (TREE_CODE (arg1) == INTEGER_CST) | |
3527 | { | |
3528 | arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1)); | |
3529 | code = BIT_AND_EXPR; | |
3530 | goto bit_and; | |
3531 | } | |
3532 | goto binary; | |
3533 | ||
3534 | case TRUNC_DIV_EXPR: | |
3535 | case ROUND_DIV_EXPR: | |
3536 | case FLOOR_DIV_EXPR: | |
3537 | case CEIL_DIV_EXPR: | |
3538 | case EXACT_DIV_EXPR: | |
3539 | case RDIV_EXPR: | |
3540 | if (integer_onep (arg1)) | |
3541 | return non_lvalue (convert (type, arg0)); | |
3542 | if (integer_zerop (arg1)) | |
3543 | return t; | |
3b998c11 RK |
3544 | |
3545 | /* If we have ((a * C1) / C2) and C1 % C2 == 0, we can replace this with | |
3546 | (a * (C1/C2). Also look for when we have a SAVE_EXPR in | |
3547 | between. */ | |
3548 | if (TREE_CODE (arg1) == INTEGER_CST | |
3549 | && TREE_INT_CST_LOW (arg1) > 0 && TREE_INT_CST_HIGH (arg1) == 0 | |
3550 | && TREE_CODE (arg0) == MULT_EXPR | |
3551 | && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST | |
3552 | && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) > 0 | |
3553 | && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0 | |
3554 | && 0 == (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) | |
3555 | % TREE_INT_CST_LOW (arg1))) | |
3556 | { | |
3557 | tree new_op | |
3558 | = build_int_2 (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) | |
906c4e36 | 3559 | / TREE_INT_CST_LOW (arg1), 0); |
3b998c11 RK |
3560 | |
3561 | TREE_TYPE (new_op) = type; | |
3562 | return build (MULT_EXPR, type, TREE_OPERAND (arg0, 0), new_op); | |
3563 | } | |
3564 | ||
3565 | else if (TREE_CODE (arg1) == INTEGER_CST | |
3566 | && TREE_INT_CST_LOW (arg1) > 0 && TREE_INT_CST_HIGH (arg1) == 0 | |
3567 | && TREE_CODE (arg0) == SAVE_EXPR | |
3568 | && TREE_CODE (TREE_OPERAND (arg0, 0)) == MULT_EXPR | |
3569 | && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)) | |
3570 | == INTEGER_CST) | |
3571 | && (TREE_INT_CST_LOW (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)) | |
3572 | > 0) | |
3573 | && (TREE_INT_CST_HIGH (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)) | |
3574 | == 0) | |
3575 | && (TREE_INT_CST_LOW (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)) | |
3576 | % TREE_INT_CST_LOW (arg1)) == 0) | |
3577 | { | |
3578 | tree new_op | |
3579 | = build_int_2 (TREE_INT_CST_LOW (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)) | |
906c4e36 | 3580 | / TREE_INT_CST_LOW (arg1), 0); |
3b998c11 RK |
3581 | |
3582 | TREE_TYPE (new_op) = type; | |
3583 | return build (MULT_EXPR, type, | |
3584 | TREE_OPERAND (TREE_OPERAND (arg0, 0), 0), new_op); | |
3585 | } | |
3586 | ||
6d716ca8 RS |
3587 | #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) |
3588 | #ifndef REAL_INFINITY | |
3589 | if (TREE_CODE (arg1) == REAL_CST | |
3590 | && real_zerop (arg1)) | |
3591 | return t; | |
3592 | #endif | |
3593 | #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */ | |
3594 | ||
3595 | goto binary; | |
3596 | ||
3597 | case CEIL_MOD_EXPR: | |
3598 | case FLOOR_MOD_EXPR: | |
3599 | case ROUND_MOD_EXPR: | |
3600 | case TRUNC_MOD_EXPR: | |
3601 | if (integer_onep (arg1)) | |
3602 | return omit_one_operand (type, integer_zero_node, arg0); | |
3603 | if (integer_zerop (arg1)) | |
3604 | return t; | |
3605 | goto binary; | |
3606 | ||
3607 | case LSHIFT_EXPR: | |
3608 | case RSHIFT_EXPR: | |
3609 | case LROTATE_EXPR: | |
3610 | case RROTATE_EXPR: | |
3611 | if (integer_zerop (arg1)) | |
3612 | return non_lvalue (convert (type, arg0)); | |
3613 | /* Since negative shift count is not well-defined, | |
3614 | don't try to compute it in the compiler. */ | |
3615 | if (tree_int_cst_lt (arg1, integer_zero_node)) | |
3616 | return t; | |
3617 | goto binary; | |
3618 | ||
3619 | case MIN_EXPR: | |
3620 | if (operand_equal_p (arg0, arg1, 0)) | |
3621 | return arg0; | |
3622 | if (TREE_CODE (type) == INTEGER_TYPE | |
3623 | && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1)) | |
3624 | return omit_one_operand (type, arg1, arg0); | |
3625 | goto associate; | |
3626 | ||
3627 | case MAX_EXPR: | |
3628 | if (operand_equal_p (arg0, arg1, 0)) | |
3629 | return arg0; | |
3630 | if (TREE_CODE (type) == INTEGER_TYPE | |
3631 | && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1)) | |
3632 | return omit_one_operand (type, arg1, arg0); | |
3633 | goto associate; | |
3634 | ||
3635 | case TRUTH_NOT_EXPR: | |
3636 | /* Note that the operand of this must be an int | |
3637 | and its values must be 0 or 1. | |
3638 | ("true" is a fixed value perhaps depending on the language, | |
3639 | but we don't handle values other than 1 correctly yet.) */ | |
3640 | return invert_truthvalue (arg0); | |
3641 | ||
3642 | case TRUTH_ANDIF_EXPR: | |
3643 | /* Note that the operands of this must be ints | |
3644 | and their values must be 0 or 1. | |
3645 | ("true" is a fixed value perhaps depending on the language.) */ | |
3646 | /* If first arg is constant zero, return it. */ | |
3647 | if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0)) | |
3648 | return arg0; | |
3649 | case TRUTH_AND_EXPR: | |
3650 | /* If either arg is constant true, drop it. */ | |
3651 | if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0)) | |
3652 | return non_lvalue (arg1); | |
3653 | if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)) | |
3654 | return non_lvalue (arg0); | |
3655 | /* Both known to be zero => return zero. */ | |
3656 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST) | |
3657 | return arg0; | |
3658 | ||
3659 | truth_andor: | |
3660 | /* Check for the possibility of merging component references. If our | |
3661 | lhs is another similar operation, try to merge its rhs with our | |
3662 | rhs. Then try to merge our lhs and rhs. */ | |
3663 | if (optimize) | |
3664 | { | |
6d716ca8 RS |
3665 | if (TREE_CODE (arg0) == code) |
3666 | { | |
b2215d83 TW |
3667 | tem = fold_truthop (code, type, |
3668 | TREE_OPERAND (arg0, 1), arg1); | |
6d716ca8 RS |
3669 | if (tem) |
3670 | return fold (build (code, type, TREE_OPERAND (arg0, 0), tem)); | |
3671 | } | |
3672 | ||
b2215d83 | 3673 | tem = fold_truthop (code, type, arg0, arg1); |
6d716ca8 RS |
3674 | if (tem) |
3675 | return tem; | |
3676 | } | |
3677 | return t; | |
3678 | ||
3679 | case TRUTH_ORIF_EXPR: | |
3680 | /* Note that the operands of this must be ints | |
3681 | and their values must be 0 or true. | |
3682 | ("true" is a fixed value perhaps depending on the language.) */ | |
3683 | /* If first arg is constant true, return it. */ | |
3684 | if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0)) | |
3685 | return arg0; | |
3686 | case TRUTH_OR_EXPR: | |
3687 | /* If either arg is constant zero, drop it. */ | |
3688 | if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0)) | |
3689 | return non_lvalue (arg1); | |
3690 | if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)) | |
3691 | return non_lvalue (arg0); | |
3692 | /* Both known to be true => return true. */ | |
3693 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST) | |
3694 | return arg0; | |
3695 | goto truth_andor; | |
3696 | ||
3697 | case EQ_EXPR: | |
3698 | case NE_EXPR: | |
3699 | case LT_EXPR: | |
3700 | case GT_EXPR: | |
3701 | case LE_EXPR: | |
3702 | case GE_EXPR: | |
3703 | /* If one arg is a constant integer, put it last. */ | |
3704 | if (TREE_CODE (arg0) == INTEGER_CST | |
3705 | && TREE_CODE (arg1) != INTEGER_CST) | |
3706 | { | |
3707 | TREE_OPERAND (t, 0) = arg1; | |
3708 | TREE_OPERAND (t, 1) = arg0; | |
3709 | arg0 = TREE_OPERAND (t, 0); | |
3710 | arg1 = TREE_OPERAND (t, 1); | |
c05a9b68 | 3711 | code = swap_tree_comparison (code); |
6d716ca8 RS |
3712 | TREE_SET_CODE (t, code); |
3713 | } | |
3714 | ||
3715 | /* Convert foo++ == CONST into ++foo == CONST + INCR. | |
3716 | First, see if one arg is constant; find the constant arg | |
3717 | and the other one. */ | |
3718 | { | |
3719 | tree constop = 0, varop; | |
3720 | tree *constoploc; | |
3721 | ||
3722 | if (TREE_CONSTANT (arg1)) | |
3723 | constoploc = &TREE_OPERAND (t, 1), constop = arg1, varop = arg0; | |
3724 | if (TREE_CONSTANT (arg0)) | |
3725 | constoploc = &TREE_OPERAND (t, 0), constop = arg0, varop = arg1; | |
3726 | ||
3727 | if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR) | |
3728 | { | |
6d716ca8 RS |
3729 | /* This optimization is invalid for ordered comparisons |
3730 | if CONST+INCR overflows or if foo+incr might overflow. | |
c05a9b68 | 3731 | This optimization is invalid for floating point due to rounding. |
6d716ca8 RS |
3732 | For pointer types we assume overflow doesn't happen. */ |
3733 | if (TREE_CODE (TREE_TYPE (varop)) == POINTER_TYPE | |
c05a9b68 RS |
3734 | || (TREE_CODE (TREE_TYPE (varop)) != REAL_TYPE |
3735 | && (code == EQ_EXPR || code == NE_EXPR))) | |
6d716ca8 | 3736 | { |
c05a9b68 RS |
3737 | tree newconst |
3738 | = fold (build (PLUS_EXPR, TREE_TYPE (varop), | |
3739 | constop, TREE_OPERAND (varop, 1))); | |
3740 | TREE_SET_CODE (varop, PREINCREMENT_EXPR); | |
3741 | *constoploc = newconst; | |
3742 | return t; | |
6d716ca8 RS |
3743 | } |
3744 | } | |
3745 | else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR) | |
3746 | { | |
6d716ca8 | 3747 | if (TREE_CODE (TREE_TYPE (varop)) == POINTER_TYPE |
c05a9b68 RS |
3748 | || (TREE_CODE (TREE_TYPE (varop)) != REAL_TYPE |
3749 | && (code == EQ_EXPR || code == NE_EXPR))) | |
6d716ca8 | 3750 | { |
c05a9b68 RS |
3751 | tree newconst |
3752 | = fold (build (MINUS_EXPR, TREE_TYPE (varop), | |
3753 | constop, TREE_OPERAND (varop, 1))); | |
3754 | TREE_SET_CODE (varop, PREDECREMENT_EXPR); | |
3755 | *constoploc = newconst; | |
3756 | return t; | |
6d716ca8 RS |
3757 | } |
3758 | } | |
3759 | } | |
3760 | ||
3761 | /* Change X >= CST to X > (CST - 1) if CST is positive. */ | |
3762 | if (TREE_CODE (arg1) == INTEGER_CST | |
3763 | && TREE_CODE (arg0) != INTEGER_CST | |
3764 | && ! tree_int_cst_lt (arg1, integer_one_node)) | |
3765 | { | |
3766 | switch (TREE_CODE (t)) | |
3767 | { | |
3768 | case GE_EXPR: | |
3769 | code = GT_EXPR; | |
3770 | TREE_SET_CODE (t, code); | |
3771 | arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node); | |
3772 | TREE_OPERAND (t, 1) = arg1; | |
3773 | break; | |
3774 | ||
3775 | case LT_EXPR: | |
3776 | code = LE_EXPR; | |
3777 | TREE_SET_CODE (t, code); | |
3778 | arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node); | |
3779 | TREE_OPERAND (t, 1) = arg1; | |
3780 | } | |
3781 | } | |
3782 | ||
6d716ca8 RS |
3783 | /* If this is an EQ or NE comparison with zero and ARG0 is |
3784 | (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require | |
3785 | two operations, but the latter can be done in one less insn | |
3786 | one machine that have only two-operand insns or on which a | |
3787 | constant cannot be the first operand. */ | |
3788 | if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR) | |
3789 | && TREE_CODE (arg0) == BIT_AND_EXPR) | |
3790 | { | |
3791 | if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR | |
3792 | && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0))) | |
3793 | return | |
3794 | fold (build (code, type, | |
3795 | build (BIT_AND_EXPR, TREE_TYPE (arg0), | |
3796 | build (RSHIFT_EXPR, | |
3797 | TREE_TYPE (TREE_OPERAND (arg0, 0)), | |
3798 | TREE_OPERAND (arg0, 1), | |
3799 | TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)), | |
3800 | convert (TREE_TYPE (arg0), | |
3801 | integer_one_node)), | |
3802 | arg1)); | |
3803 | else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR | |
3804 | && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0))) | |
3805 | return | |
3806 | fold (build (code, type, | |
3807 | build (BIT_AND_EXPR, TREE_TYPE (arg0), | |
3808 | build (RSHIFT_EXPR, | |
3809 | TREE_TYPE (TREE_OPERAND (arg0, 1)), | |
3810 | TREE_OPERAND (arg0, 0), | |
3811 | TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)), | |
3812 | convert (TREE_TYPE (arg0), | |
3813 | integer_one_node)), | |
3814 | arg1)); | |
3815 | } | |
3816 | ||
3817 | /* If this is an NE comparison of zero with an AND of one, remove the | |
3818 | comparison since the AND will give the correct value. */ | |
3819 | if (code == NE_EXPR && integer_zerop (arg1) | |
3820 | && TREE_CODE (arg0) == BIT_AND_EXPR | |
3821 | && integer_onep (TREE_OPERAND (arg0, 1))) | |
3822 | return convert (type, arg0); | |
3823 | ||
3824 | /* If we have (A & C) == C where C is a power of 2, convert this into | |
3825 | (A & C) != 0. Similarly for NE_EXPR. */ | |
3826 | if ((code == EQ_EXPR || code == NE_EXPR) | |
3827 | && TREE_CODE (arg0) == BIT_AND_EXPR | |
3828 | && integer_pow2p (TREE_OPERAND (arg0, 1)) | |
3829 | && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0)) | |
3830 | return build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type, | |
3831 | arg0, integer_zero_node); | |
3832 | ||
c05a9b68 RS |
3833 | /* Simplify comparison of something with itself. (For IEEE |
3834 | floating-point, we can only do some of these simplifications.) */ | |
3835 | if (operand_equal_p (arg0, arg1, 0)) | |
6d716ca8 RS |
3836 | { |
3837 | switch (code) | |
3838 | { | |
3839 | case EQ_EXPR: | |
3840 | case GE_EXPR: | |
3841 | case LE_EXPR: | |
c05a9b68 RS |
3842 | if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE) |
3843 | { | |
3844 | t = build_int_2 (1, 0); | |
3845 | TREE_TYPE (t) = type; | |
3846 | return t; | |
3847 | } | |
3848 | code = EQ_EXPR; | |
3849 | TREE_SET_CODE (t, code); | |
3850 | break; | |
3851 | ||
6d716ca8 | 3852 | case NE_EXPR: |
c05a9b68 RS |
3853 | /* For NE, we can only do this simplification if integer. */ |
3854 | if (TREE_CODE (TREE_TYPE (arg0)) != INTEGER_TYPE) | |
3855 | break; | |
3856 | /* ... fall through ... */ | |
6d716ca8 RS |
3857 | case GT_EXPR: |
3858 | case LT_EXPR: | |
3859 | t = build_int_2 (0, 0); | |
3860 | TREE_TYPE (t) = type; | |
3861 | return t; | |
3862 | } | |
3863 | } | |
3864 | ||
3865 | /* An unsigned comparison against 0 can be simplified. */ | |
3866 | if (integer_zerop (arg1) | |
3867 | && (TREE_CODE (TREE_TYPE (arg1)) == INTEGER_TYPE | |
3868 | || TREE_CODE (TREE_TYPE (arg1)) == POINTER_TYPE) | |
3869 | && TREE_UNSIGNED (TREE_TYPE (arg1))) | |
3870 | { | |
3871 | switch (TREE_CODE (t)) | |
3872 | { | |
3873 | case GT_EXPR: | |
c05a9b68 | 3874 | code = NE_EXPR; |
6d716ca8 RS |
3875 | TREE_SET_CODE (t, NE_EXPR); |
3876 | break; | |
3877 | case LE_EXPR: | |
c05a9b68 | 3878 | code = EQ_EXPR; |
6d716ca8 RS |
3879 | TREE_SET_CODE (t, EQ_EXPR); |
3880 | break; | |
3881 | case GE_EXPR: | |
3882 | return omit_one_operand (integer_type_node, | |
3883 | integer_one_node, arg0); | |
3884 | case LT_EXPR: | |
3885 | return omit_one_operand (integer_type_node, | |
3886 | integer_zero_node, arg0); | |
3887 | } | |
3888 | } | |
3889 | ||
c05a9b68 RS |
3890 | /* If we are comparing an expression that just has comparisons |
3891 | of two integer values, arithmetic expressions of those comparisons, | |
3892 | and constants, we can simplify it. There are only three cases | |
3893 | to check: the two values can either be equal, the first can be | |
3894 | greater, or the second can be greater. Fold the expression for | |
3895 | those three values. Since each value must be 0 or 1, we have | |
3896 | eight possibilities, each of which corresponds to the constant 0 | |
3897 | or 1 or one of the six possible comparisons. | |
3898 | ||
3899 | This handles common cases like (a > b) == 0 but also handles | |
3900 | expressions like ((x > y) - (y > x)) > 0, which supposedly | |
3901 | occur in macroized code. */ | |
3902 | ||
3903 | if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST) | |
3904 | { | |
3905 | tree cval1 = 0, cval2 = 0; | |
3906 | ||
3907 | if (twoval_comparison_p (arg0, &cval1, &cval2) | |
3908 | /* Don't handle degenerate cases here; they should already | |
3909 | have been handled anyway. */ | |
3910 | && cval1 != 0 && cval2 != 0 | |
3911 | && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2)) | |
3912 | && TREE_TYPE (cval1) == TREE_TYPE (cval2) | |
3913 | && TREE_CODE (TREE_TYPE (cval1)) == INTEGER_TYPE | |
3914 | && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)), | |
3915 | TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0)) | |
3916 | { | |
3917 | tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1)); | |
3918 | tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1)); | |
3919 | ||
3920 | /* We can't just pass T to eval_subst in case cval1 or cval2 | |
3921 | was the same as ARG1. */ | |
3922 | ||
3923 | tree high_result | |
3924 | = fold (build (code, type, | |
3925 | eval_subst (arg0, cval1, maxval, cval2, minval), | |
3926 | arg1)); | |
3927 | tree equal_result | |
3928 | = fold (build (code, type, | |
3929 | eval_subst (arg0, cval1, maxval, cval2, maxval), | |
3930 | arg1)); | |
3931 | tree low_result | |
3932 | = fold (build (code, type, | |
3933 | eval_subst (arg0, cval1, minval, cval2, maxval), | |
3934 | arg1)); | |
3935 | ||
3936 | /* All three of these results should be 0 or 1. Confirm they | |
3937 | are. Then use those values to select the proper code | |
3938 | to use. */ | |
3939 | ||
3940 | if ((integer_zerop (high_result) | |
3941 | || integer_onep (high_result)) | |
3942 | && (integer_zerop (equal_result) | |
3943 | || integer_onep (equal_result)) | |
3944 | && (integer_zerop (low_result) | |
3945 | || integer_onep (low_result))) | |
3946 | { | |
3947 | /* Make a 3-bit mask with the high-order bit being the | |
3948 | value for `>', the next for '=', and the low for '<'. */ | |
3949 | switch ((integer_onep (high_result) * 4) | |
3950 | + (integer_onep (equal_result) * 2) | |
3951 | + integer_onep (low_result)) | |
3952 | { | |
3953 | case 0: | |
3954 | /* Always false. */ | |
13837058 | 3955 | return omit_one_operand (type, integer_zero_node, arg0); |
c05a9b68 RS |
3956 | case 1: |
3957 | code = LT_EXPR; | |
3958 | break; | |
3959 | case 2: | |
3960 | code = EQ_EXPR; | |
3961 | break; | |
3962 | case 3: | |
3963 | code = LE_EXPR; | |
3964 | break; | |
3965 | case 4: | |
3966 | code = GT_EXPR; | |
3967 | break; | |
3968 | case 5: | |
3969 | code = NE_EXPR; | |
3970 | break; | |
3971 | case 6: | |
3972 | code = GE_EXPR; | |
3973 | break; | |
3974 | case 7: | |
3975 | /* Always true. */ | |
13837058 | 3976 | return omit_one_operand (type, integer_one_node, arg0); |
c05a9b68 RS |
3977 | } |
3978 | ||
95ca4f96 | 3979 | return fold (build (code, type, cval1, cval2)); |
c05a9b68 RS |
3980 | } |
3981 | } | |
3982 | } | |
3983 | ||
3984 | /* If this is a comparison of a field, we may be able to simplify it. */ | |
3985 | if ((TREE_CODE (arg0) == COMPONENT_REF | |
3986 | || TREE_CODE (arg0) == BIT_FIELD_REF) | |
3987 | && (code == EQ_EXPR || code == NE_EXPR) | |
3988 | /* Handle the constant case even without -O | |
3989 | to make sure the warnings are given. */ | |
3990 | && (optimize || TREE_CODE (arg1) == INTEGER_CST)) | |
3991 | { | |
3992 | t1 = optimize_bit_field_compare (code, type, arg0, arg1); | |
3993 | return t1 ? t1 : t; | |
3994 | } | |
3995 | ||
3996 | /* From here on, the only cases we handle are when the result is | |
3997 | known to be a constant. | |
3998 | ||
3999 | To compute GT, swap the arguments and do LT. | |
6d716ca8 RS |
4000 | To compute GE, do LT and invert the result. |
4001 | To compute LE, swap the arguments, do LT and invert the result. | |
c05a9b68 RS |
4002 | To compute NE, do EQ and invert the result. |
4003 | ||
4004 | Therefore, the code below must handle only EQ and LT. */ | |
4005 | ||
6d716ca8 RS |
4006 | if (code == LE_EXPR || code == GT_EXPR) |
4007 | { | |
c05a9b68 RS |
4008 | tem = arg0, arg0 = arg1, arg1 = tem; |
4009 | code = swap_tree_comparison (code); | |
4010 | } | |
4011 | ||
4012 | /* Note that it is safe to invert for real values here because we | |
4013 | will check below in the one case that it matters. */ | |
4014 | ||
4015 | invert = 0; | |
4016 | if (code == NE_EXPR || code == GE_EXPR) | |
4017 | { | |
4018 | invert = 1; | |
4019 | code = invert_tree_comparison (code); | |
6d716ca8 RS |
4020 | } |
4021 | ||
4022 | /* Compute a result for LT or EQ if args permit; | |
4023 | otherwise return T. */ | |
c05a9b68 | 4024 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST) |
6d716ca8 | 4025 | { |
c05a9b68 RS |
4026 | if (code == EQ_EXPR) |
4027 | t1 = build_int_2 ((TREE_INT_CST_LOW (arg0) | |
4028 | == TREE_INT_CST_LOW (arg1)) | |
4029 | && (TREE_INT_CST_HIGH (arg0) | |
4030 | == TREE_INT_CST_HIGH (arg1)), | |
4031 | 0); | |
6d716ca8 | 4032 | else |
c05a9b68 RS |
4033 | t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0)) |
4034 | ? INT_CST_LT_UNSIGNED (arg0, arg1) | |
4035 | : INT_CST_LT (arg0, arg1)), | |
4036 | 0); | |
6d716ca8 | 4037 | } |
c05a9b68 | 4038 | |
6d716ca8 RS |
4039 | /* Assume a nonexplicit constant cannot equal an explicit one, |
4040 | since such code would be undefined anyway. | |
4041 | Exception: on sysvr4, using #pragma weak, | |
4042 | a label can come out as 0. */ | |
4043 | else if (TREE_CODE (arg1) == INTEGER_CST | |
4044 | && !integer_zerop (arg1) | |
4045 | && TREE_CONSTANT (arg0) | |
4046 | && TREE_CODE (arg0) == ADDR_EXPR | |
c05a9b68 RS |
4047 | && code == EQ_EXPR) |
4048 | t1 = build_int_2 (0, 0); | |
4049 | ||
6d716ca8 | 4050 | /* Two real constants can be compared explicitly. */ |
c05a9b68 | 4051 | else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST) |
6d716ca8 | 4052 | { |
c05a9b68 RS |
4053 | /* If either operand is a NaN, the result is false with two |
4054 | exceptions: First, an NE_EXPR is true on NaNs, but that case | |
4055 | is already handled correctly since we will be inverting the | |
4056 | result for NE_EXPR. Second, if we had inverted a LE_EXPR | |
4057 | or a GE_EXPR into a LT_EXPR, we must return true so that it | |
4058 | will be inverted into false. */ | |
4059 | ||
4060 | if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0)) | |
4061 | || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))) | |
4062 | t1 = build_int_2 (invert && code == LT_EXPR, 0); | |
4063 | ||
4064 | else if (code == EQ_EXPR) | |
4065 | t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0), | |
4066 | TREE_REAL_CST (arg1)), | |
4067 | 0); | |
6d716ca8 | 4068 | else |
c05a9b68 RS |
4069 | t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0), |
4070 | TREE_REAL_CST (arg1)), | |
4071 | 0); | |
6d716ca8 RS |
4072 | } |
4073 | ||
c05a9b68 RS |
4074 | if (t1 == NULL_TREE) |
4075 | return t; | |
4076 | ||
4077 | if (invert) | |
4078 | TREE_INT_CST_LOW (t1) ^= 1; | |
4079 | ||
4080 | TREE_TYPE (t1) = type; | |
4081 | return t1; | |
6d716ca8 RS |
4082 | |
4083 | case COND_EXPR: | |
4084 | if (TREE_CODE (arg0) == INTEGER_CST) | |
4085 | return TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)); | |
4086 | else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0)) | |
4087 | return omit_one_operand (type, arg1, arg0); | |
6d716ca8 | 4088 | |
c05a9b68 RS |
4089 | /* If the second operand is zero, invert the comparison and swap |
4090 | the second and third operands. Likewise if the second operand | |
4091 | is constant and the third is not or if the third operand is | |
4092 | equivalent to the first operand of the comparison. */ | |
6d716ca8 | 4093 | |
c05a9b68 RS |
4094 | if (integer_zerop (arg1) |
4095 | || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2))) | |
4096 | || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<' | |
4097 | && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0), | |
4098 | TREE_OPERAND (t, 2), | |
4099 | TREE_OPERAND (arg0, 1)))) | |
4100 | { | |
4101 | /* See if this can be inverted. If it can't, possibly because | |
4102 | it was a floating-point inequality comparison, don't do | |
4103 | anything. */ | |
4104 | tem = invert_truthvalue (arg0); | |
6d716ca8 | 4105 | |
c05a9b68 RS |
4106 | if (TREE_CODE (tem) != TRUTH_NOT_EXPR) |
4107 | { | |
4108 | arg0 = TREE_OPERAND (t, 0) = tem; | |
4109 | TREE_OPERAND (t, 1) = TREE_OPERAND (t, 2); | |
4110 | TREE_OPERAND (t, 2) = arg1; | |
4111 | arg1 = TREE_OPERAND (t, 1); | |
4112 | } | |
4113 | } | |
6d716ca8 | 4114 | |
c05a9b68 RS |
4115 | /* If we have A op B ? A : C, we may be able to convert this to a |
4116 | simpler expression, depending on the operation and the values | |
b5c52586 RS |
4117 | of B and C. IEEE floating point prevents this though, |
4118 | because A or B might be -0.0 or a NaN. */ | |
6d716ca8 | 4119 | |
c05a9b68 | 4120 | if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<' |
b5c52586 RS |
4121 | && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT |
4122 | || TREE_CODE (TREE_TYPE (TREE_OPERAND (arg0, 0))) != REAL_TYPE) | |
c05a9b68 RS |
4123 | && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0), |
4124 | arg1, TREE_OPERAND (arg0, 1))) | |
6d716ca8 | 4125 | { |
c05a9b68 RS |
4126 | tree arg2 = TREE_OPERAND (t, 2); |
4127 | enum tree_code comp_code = TREE_CODE (arg0); | |
4128 | ||
4129 | /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A), | |
4130 | depending on the comparison operation. */ | |
4131 | if (integer_zerop (TREE_OPERAND (arg0, 1)) | |
4132 | && TREE_CODE (arg2) == NEGATE_EXPR | |
4133 | && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0)) | |
4134 | switch (comp_code) | |
4135 | { | |
4136 | case EQ_EXPR: | |
4137 | return fold (build1 (NEGATE_EXPR, type, arg1)); | |
4138 | case NE_EXPR: | |
cdc54cc9 | 4139 | return convert (type, arg1); |
c05a9b68 RS |
4140 | case GE_EXPR: |
4141 | case GT_EXPR: | |
4142 | return fold (build1 (ABS_EXPR, type, arg1)); | |
4143 | case LE_EXPR: | |
4144 | case LT_EXPR: | |
4145 | return fold (build1 (NEGATE_EXPR, type, | |
4146 | fold (build1 (ABS_EXPR, type, arg1)))); | |
4147 | } | |
6d716ca8 | 4148 | |
c05a9b68 RS |
4149 | /* If this is A != 0 ? A : 0, this is simply A. For ==, it is |
4150 | always zero. */ | |
6d716ca8 | 4151 | |
29ebe69a | 4152 | if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2)) |
c05a9b68 RS |
4153 | { |
4154 | if (comp_code == NE_EXPR) | |
cdc54cc9 | 4155 | return convert (type, arg1); |
c05a9b68 RS |
4156 | else if (comp_code == EQ_EXPR) |
4157 | return convert (type, integer_zero_node); | |
4158 | } | |
4159 | ||
4160 | /* If this is A op B ? A : B, this is either A, B, min (A, B), | |
4161 | or max (A, B), depending on the operation. */ | |
4162 | ||
4163 | if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1), | |
4164 | arg2, TREE_OPERAND (arg0, 0))) | |
4165 | switch (comp_code) | |
4166 | { | |
4167 | case EQ_EXPR: | |
cdc54cc9 | 4168 | return convert (type, arg2); |
c05a9b68 | 4169 | case NE_EXPR: |
cdc54cc9 | 4170 | return convert (type, arg1); |
c05a9b68 RS |
4171 | case LE_EXPR: |
4172 | case LT_EXPR: | |
4173 | return fold (build (MIN_EXPR, type, arg1, arg2)); | |
4174 | case GE_EXPR: | |
4175 | case GT_EXPR: | |
4176 | return fold (build (MAX_EXPR, type, arg1, arg2)); | |
4177 | } | |
4178 | ||
4179 | /* If this is A op C1 ? A : C2 with C1 and C2 constant integers, | |
4180 | we might still be able to simplify this. For example, | |
4181 | if C1 is one less or one more than C2, this might have started | |
53d2fb4f RS |
4182 | out as a MIN or MAX and been transformed by this function. |
4183 | Only good for INTEGER_TYPE, because we need TYPE_MAX_VALUE. */ | |
c05a9b68 | 4184 | |
53d2fb4f RS |
4185 | if (TREE_CODE (type) == INTEGER_TYPE |
4186 | && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST | |
c05a9b68 RS |
4187 | && TREE_CODE (arg2) == INTEGER_CST) |
4188 | switch (comp_code) | |
4189 | { | |
4190 | case EQ_EXPR: | |
4191 | /* We can replace A with C1 in this case. */ | |
4192 | arg1 = TREE_OPERAND (t, 1) | |
4193 | = convert (type, TREE_OPERAND (arg0, 1)); | |
4194 | break; | |
4195 | ||
4196 | case LT_EXPR: | |
4197 | /* If C1 is C2 + 1, this is min(A, C2). */ | |
4198 | if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1) | |
4199 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
4200 | const_binop (PLUS_EXPR, arg2, | |
4201 | integer_one_node), 1)) | |
4202 | return fold (build (MIN_EXPR, type, arg1, arg2)); | |
4203 | break; | |
4204 | ||
4205 | case LE_EXPR: | |
4206 | /* If C1 is C2 - 1, this is min(A, C2). */ | |
4207 | if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1) | |
4208 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
4209 | const_binop (MINUS_EXPR, arg2, | |
4210 | integer_one_node), 1)) | |
4211 | return fold (build (MIN_EXPR, type, arg1, arg2)); | |
4212 | break; | |
4213 | ||
4214 | case GT_EXPR: | |
4215 | /* If C1 is C2 - 1, this is max(A, C2). */ | |
4216 | if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1) | |
4217 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
4218 | const_binop (MINUS_EXPR, arg2, | |
4219 | integer_one_node), 1)) | |
4220 | return fold (build (MAX_EXPR, type, arg1, arg2)); | |
4221 | break; | |
4222 | ||
4223 | case GE_EXPR: | |
4224 | /* If C1 is C2 + 1, this is max(A, C2). */ | |
4225 | if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1) | |
4226 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
4227 | const_binop (PLUS_EXPR, arg2, | |
4228 | integer_one_node), 1)) | |
4229 | return fold (build (MAX_EXPR, type, arg1, arg2)); | |
4230 | break; | |
4231 | } | |
6d716ca8 RS |
4232 | } |
4233 | ||
c05a9b68 RS |
4234 | /* Convert A ? 1 : 0 to simply A. */ |
4235 | if (integer_onep (TREE_OPERAND (t, 1)) | |
4236 | && integer_zerop (TREE_OPERAND (t, 2)) | |
4237 | /* If we try to convert TREE_OPERAND (t, 0) to our type, the | |
4238 | call to fold will try to move the conversion inside | |
4239 | a COND, which will recurse. In that case, the COND_EXPR | |
4240 | is probably the best choice, so leave it alone. */ | |
4241 | && type == TREE_TYPE (arg0)) | |
4242 | return arg0; | |
6d716ca8 | 4243 | |
6d716ca8 | 4244 | |
c05a9b68 RS |
4245 | /* Look for expressions of the form A & 2 ? 2 : 0. The result of this |
4246 | operation is simply A & 2. */ | |
6d716ca8 RS |
4247 | |
4248 | if (integer_zerop (TREE_OPERAND (t, 2)) | |
4249 | && TREE_CODE (arg0) == NE_EXPR | |
4250 | && integer_zerop (TREE_OPERAND (arg0, 1)) | |
c05a9b68 RS |
4251 | && integer_pow2p (arg1) |
4252 | && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR | |
4253 | && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1), | |
4254 | arg1, 1)) | |
4255 | return convert (type, TREE_OPERAND (arg0, 0)); | |
6d716ca8 | 4256 | |
6d716ca8 RS |
4257 | return t; |
4258 | ||
4259 | case COMPOUND_EXPR: | |
4260 | if (!TREE_SIDE_EFFECTS (arg0)) | |
4261 | return arg1; | |
4262 | return t; | |
4263 | ||
4264 | default: | |
4265 | return t; | |
4266 | } /* switch (code) */ | |
4267 | } |