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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 | ||
6d716ca8 RS |
51 | void lshift_double (); |
52 | void rshift_double (); | |
53 | void lrotate_double (); | |
54 | void rrotate_double (); | |
55 | static tree const_binop (); | |
56 | \f | |
57 | /* To do constant folding on INTEGER_CST nodes requires 64-bit arithmetic. | |
58 | We do that by representing the 64-bit integer as 8 shorts, | |
59 | with only 8 bits stored in each short, as a positive number. */ | |
60 | ||
61 | /* Unpack a 64-bit integer into 8 shorts. | |
62 | LOW and HI are the integer, as two `int' pieces. | |
63 | SHORTS points to the array of shorts. */ | |
64 | ||
65 | static void | |
66 | encode (shorts, low, hi) | |
67 | short *shorts; | |
68 | int low, hi; | |
69 | { | |
70 | shorts[0] = low & 0xff; | |
71 | shorts[1] = (low >> 8) & 0xff; | |
72 | shorts[2] = (low >> 16) & 0xff; | |
73 | shorts[3] = (low >> 24) & 0xff; | |
74 | shorts[4] = hi & 0xff; | |
75 | shorts[5] = (hi >> 8) & 0xff; | |
76 | shorts[6] = (hi >> 16) & 0xff; | |
77 | shorts[7] = (hi >> 24) & 0xff; | |
78 | } | |
79 | ||
80 | /* Pack an array of 8 shorts into a 64-bit integer. | |
81 | SHORTS points to the array of shorts. | |
82 | The integer is stored into *LOW and *HI as two `int' pieces. */ | |
83 | ||
84 | static void | |
85 | decode (shorts, low, hi) | |
86 | short *shorts; | |
87 | int *low, *hi; | |
88 | { | |
89 | /* The casts in the following statement should not be | |
90 | needed, but they get around bugs in some C compilers. */ | |
91 | *low = (((long)shorts[3] << 24) | ((long)shorts[2] << 16) | |
92 | | ((long)shorts[1] << 8) | (long)shorts[0]); | |
93 | *hi = (((long)shorts[7] << 24) | ((long)shorts[6] << 16) | |
94 | | ((long)shorts[5] << 8) | (long)shorts[4]); | |
95 | } | |
96 | \f | |
97 | /* Make the integer constant T valid for its type | |
98 | by setting to 0 or 1 all the bits in the constant | |
99 | that don't belong in the type. */ | |
100 | ||
101 | static void | |
102 | force_fit_type (t) | |
103 | tree t; | |
104 | { | |
105 | register int prec = TYPE_PRECISION (TREE_TYPE (t)); | |
106 | ||
107 | if (TREE_CODE (TREE_TYPE (t)) == POINTER_TYPE) | |
108 | prec = POINTER_SIZE; | |
109 | ||
110 | /* First clear all bits that are beyond the type's precision. */ | |
111 | ||
112 | if (prec == 2 * HOST_BITS_PER_INT) | |
113 | ; | |
114 | else if (prec > HOST_BITS_PER_INT) | |
115 | { | |
116 | TREE_INT_CST_HIGH (t) | |
117 | &= ~((-1) << (prec - HOST_BITS_PER_INT)); | |
118 | } | |
119 | else | |
120 | { | |
121 | TREE_INT_CST_HIGH (t) = 0; | |
122 | if (prec < HOST_BITS_PER_INT) | |
123 | TREE_INT_CST_LOW (t) | |
124 | &= ~((-1) << prec); | |
125 | } | |
126 | ||
127 | /* If it's a signed type and value's sign bit is set, extend the sign. */ | |
128 | ||
129 | if (! TREE_UNSIGNED (TREE_TYPE (t)) | |
130 | && prec != 2 * HOST_BITS_PER_INT | |
131 | && (prec > HOST_BITS_PER_INT | |
132 | ? TREE_INT_CST_HIGH (t) & (1 << (prec - HOST_BITS_PER_INT - 1)) | |
133 | : TREE_INT_CST_LOW (t) & (1 << (prec - 1)))) | |
134 | { | |
135 | /* Value is negative: | |
136 | set to 1 all the bits that are outside this type's precision. */ | |
137 | if (prec > HOST_BITS_PER_INT) | |
138 | { | |
139 | TREE_INT_CST_HIGH (t) | |
140 | |= ((-1) << (prec - HOST_BITS_PER_INT)); | |
141 | } | |
142 | else | |
143 | { | |
144 | TREE_INT_CST_HIGH (t) = -1; | |
145 | if (prec < HOST_BITS_PER_INT) | |
146 | TREE_INT_CST_LOW (t) | |
147 | |= ((-1) << prec); | |
148 | } | |
149 | } | |
150 | } | |
151 | \f | |
152 | /* Add two 64-bit integers with 64-bit result. | |
153 | Each argument is given as two `int' pieces. | |
154 | One argument is L1 and H1; the other, L2 and H2. | |
155 | The value is stored as two `int' pieces in *LV and *HV. | |
156 | We use the 8-shorts representation internally. */ | |
157 | ||
158 | void | |
159 | add_double (l1, h1, l2, h2, lv, hv) | |
160 | int l1, h1, l2, h2; | |
161 | int *lv, *hv; | |
162 | { | |
163 | short arg1[8]; | |
164 | short arg2[8]; | |
165 | register int carry = 0; | |
166 | register int i; | |
167 | ||
168 | encode (arg1, l1, h1); | |
169 | encode (arg2, l2, h2); | |
170 | ||
171 | for (i = 0; i < 8; i++) | |
172 | { | |
173 | carry += arg1[i] + arg2[i]; | |
174 | arg1[i] = carry & 0xff; | |
175 | carry >>= 8; | |
176 | } | |
177 | ||
178 | decode (arg1, lv, hv); | |
179 | } | |
180 | ||
181 | /* Negate a 64-bit integers with 64-bit result. | |
182 | The argument is given as two `int' pieces in L1 and H1. | |
183 | The value is stored as two `int' pieces in *LV and *HV. | |
184 | We use the 8-shorts representation internally. */ | |
185 | ||
186 | void | |
187 | neg_double (l1, h1, lv, hv) | |
188 | int l1, h1; | |
189 | int *lv, *hv; | |
190 | { | |
191 | if (l1 == 0) | |
192 | { | |
193 | *lv = 0; | |
194 | *hv = - h1; | |
195 | } | |
196 | else | |
197 | { | |
198 | *lv = - l1; | |
199 | *hv = ~ h1; | |
200 | } | |
201 | } | |
202 | \f | |
203 | /* Multiply two 64-bit integers with 64-bit result. | |
204 | Each argument is given as two `int' pieces. | |
205 | One argument is L1 and H1; the other, L2 and H2. | |
206 | The value is stored as two `int' pieces in *LV and *HV. | |
207 | We use the 8-shorts representation internally. */ | |
208 | ||
209 | void | |
210 | mul_double (l1, h1, l2, h2, lv, hv) | |
211 | int l1, h1, l2, h2; | |
212 | int *lv, *hv; | |
213 | { | |
214 | short arg1[8]; | |
215 | short arg2[8]; | |
216 | short prod[16]; | |
217 | register int carry = 0; | |
218 | register int i, j, k; | |
219 | ||
220 | /* These two cases are used extensively, arising from pointer | |
221 | combinations. */ | |
222 | if (h2 == 0) | |
223 | { | |
224 | if (l2 == 2) | |
225 | { | |
226 | unsigned temp = l1 + l1; | |
227 | *hv = h1 * 2 + (temp < l1); | |
228 | *lv = temp; | |
229 | return; | |
230 | } | |
231 | if (l2 == 4) | |
232 | { | |
233 | unsigned temp = l1 + l1; | |
234 | h1 = h1 * 4 + ((temp < l1) << 1); | |
235 | l1 = temp; | |
236 | temp += temp; | |
237 | h1 += (temp < l1); | |
238 | *lv = temp; | |
239 | *hv = h1; | |
240 | return; | |
241 | } | |
242 | if (l2 == 8) | |
243 | { | |
244 | unsigned temp = l1 + l1; | |
245 | h1 = h1 * 8 + ((temp < l1) << 2); | |
246 | l1 = temp; | |
247 | temp += temp; | |
248 | h1 += (temp < l1) << 1; | |
249 | l1 = temp; | |
250 | temp += temp; | |
251 | h1 += (temp < l1); | |
252 | *lv = temp; | |
253 | *hv = h1; | |
254 | return; | |
255 | } | |
256 | } | |
257 | ||
258 | encode (arg1, l1, h1); | |
259 | encode (arg2, l2, h2); | |
260 | ||
261 | bzero (prod, sizeof prod); | |
262 | ||
263 | for (i = 0; i < 8; i++) | |
264 | for (j = 0; j < 8; j++) | |
265 | { | |
266 | k = i + j; | |
267 | carry = arg1[i] * arg2[j]; | |
268 | while (carry) | |
269 | { | |
270 | carry += prod[k]; | |
271 | prod[k] = carry & 0xff; | |
272 | carry >>= 8; | |
273 | k++; | |
274 | } | |
275 | } | |
276 | ||
277 | decode (prod, lv, hv); /* @@decode ignores prod[8] -> prod[15] */ | |
278 | } | |
279 | \f | |
280 | /* Shift the 64-bit integer in L1, H1 left by COUNT places | |
281 | keeping only PREC bits of result. | |
282 | Shift right if COUNT is negative. | |
283 | ARITH nonzero specifies arithmetic shifting; otherwise use logical shift. | |
284 | Store the value as two `int' pieces in *LV and *HV. */ | |
285 | ||
286 | void | |
287 | lshift_double (l1, h1, count, prec, lv, hv, arith) | |
288 | int l1, h1, count, prec; | |
289 | int *lv, *hv; | |
290 | int arith; | |
291 | { | |
292 | short arg1[8]; | |
293 | register int i; | |
294 | register int carry; | |
295 | ||
296 | if (count < 0) | |
297 | { | |
298 | rshift_double (l1, h1, - count, prec, lv, hv, arith); | |
299 | return; | |
300 | } | |
301 | ||
302 | encode (arg1, l1, h1); | |
303 | ||
304 | if (count > prec) | |
305 | count = prec; | |
306 | ||
307 | while (count > 0) | |
308 | { | |
309 | carry = 0; | |
310 | for (i = 0; i < 8; i++) | |
311 | { | |
312 | carry += arg1[i] << 1; | |
313 | arg1[i] = carry & 0xff; | |
314 | carry >>= 8; | |
315 | } | |
316 | count--; | |
317 | } | |
318 | ||
319 | decode (arg1, lv, hv); | |
320 | } | |
321 | ||
322 | /* Shift the 64-bit integer in L1, H1 right by COUNT places | |
323 | keeping only PREC bits of result. COUNT must be positive. | |
324 | ARITH nonzero specifies arithmetic shifting; otherwise use logical shift. | |
325 | Store the value as two `int' pieces in *LV and *HV. */ | |
326 | ||
327 | void | |
328 | rshift_double (l1, h1, count, prec, lv, hv, arith) | |
329 | int l1, h1, count, prec; | |
330 | int *lv, *hv; | |
331 | int arith; | |
332 | { | |
333 | short arg1[8]; | |
334 | register int i; | |
335 | register int carry; | |
336 | ||
337 | encode (arg1, l1, h1); | |
338 | ||
339 | if (count > prec) | |
340 | count = prec; | |
341 | ||
342 | while (count > 0) | |
343 | { | |
344 | carry = arith && arg1[7] >> 7; | |
345 | for (i = 7; i >= 0; i--) | |
346 | { | |
347 | carry <<= 8; | |
348 | carry += arg1[i]; | |
349 | arg1[i] = (carry >> 1) & 0xff; | |
350 | } | |
351 | count--; | |
352 | } | |
353 | ||
354 | decode (arg1, lv, hv); | |
355 | } | |
356 | \f | |
357 | /* Rotate the 64-bit integer in L1, H1 left by COUNT places | |
358 | keeping only PREC bits of result. | |
359 | Rotate right if COUNT is negative. | |
360 | Store the value as two `int' pieces in *LV and *HV. */ | |
361 | ||
362 | void | |
363 | lrotate_double (l1, h1, count, prec, lv, hv) | |
364 | int l1, h1, count, prec; | |
365 | int *lv, *hv; | |
366 | { | |
367 | short arg1[8]; | |
368 | register int i; | |
369 | register int carry; | |
370 | ||
371 | if (count < 0) | |
372 | { | |
373 | rrotate_double (l1, h1, - count, prec, lv, hv); | |
374 | return; | |
375 | } | |
376 | ||
377 | encode (arg1, l1, h1); | |
378 | ||
379 | if (count > prec) | |
380 | count = prec; | |
381 | ||
382 | carry = arg1[7] >> 7; | |
383 | while (count > 0) | |
384 | { | |
385 | for (i = 0; i < 8; i++) | |
386 | { | |
387 | carry += arg1[i] << 1; | |
388 | arg1[i] = carry & 0xff; | |
389 | carry >>= 8; | |
390 | } | |
391 | count--; | |
392 | } | |
393 | ||
394 | decode (arg1, lv, hv); | |
395 | } | |
396 | ||
397 | /* Rotate the 64-bit integer in L1, H1 left by COUNT places | |
398 | keeping only PREC bits of result. COUNT must be positive. | |
399 | Store the value as two `int' pieces in *LV and *HV. */ | |
400 | ||
401 | void | |
402 | rrotate_double (l1, h1, count, prec, lv, hv) | |
403 | int l1, h1, count, prec; | |
404 | int *lv, *hv; | |
405 | { | |
406 | short arg1[8]; | |
407 | register int i; | |
408 | register int carry; | |
409 | ||
410 | encode (arg1, l1, h1); | |
411 | ||
412 | if (count > prec) | |
413 | count = prec; | |
414 | ||
415 | carry = arg1[0] & 1; | |
416 | while (count > 0) | |
417 | { | |
418 | for (i = 7; i >= 0; i--) | |
419 | { | |
420 | carry <<= 8; | |
421 | carry += arg1[i]; | |
422 | arg1[i] = (carry >> 1) & 0xff; | |
423 | } | |
424 | count--; | |
425 | } | |
426 | ||
427 | decode (arg1, lv, hv); | |
428 | } | |
429 | \f | |
430 | /* Divide 64 bit integer LNUM, HNUM by 64 bit integer LDEN, HDEN | |
431 | for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM). | |
432 | CODE is a tree code for a kind of division, one of | |
433 | TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR | |
434 | or EXACT_DIV_EXPR | |
435 | It controls how the quotient is rounded to a integer. | |
436 | UNS nonzero says do unsigned division. */ | |
437 | ||
438 | static void | |
439 | div_and_round_double (code, uns, | |
440 | lnum_orig, hnum_orig, lden_orig, hden_orig, | |
441 | lquo, hquo, lrem, hrem) | |
442 | enum tree_code code; | |
443 | int uns; | |
444 | int lnum_orig, hnum_orig; /* num == numerator == dividend */ | |
445 | int lden_orig, hden_orig; /* den == denominator == divisor */ | |
446 | int *lquo, *hquo, *lrem, *hrem; | |
447 | { | |
448 | int quo_neg = 0; | |
449 | short num[9], den[8], quo[8]; /* extra element for scaling. */ | |
450 | register int i, j, work; | |
451 | register int carry = 0; | |
452 | unsigned int lnum = lnum_orig; | |
453 | int hnum = hnum_orig; | |
454 | unsigned int lden = lden_orig; | |
455 | int hden = hden_orig; | |
456 | ||
457 | if ((hden == 0) && (lden == 0)) | |
458 | abort (); | |
459 | ||
460 | /* calculate quotient sign and convert operands to unsigned. */ | |
461 | if (!uns) | |
462 | { | |
463 | if (hden < 0) | |
464 | { | |
465 | quo_neg = ~ quo_neg; | |
466 | neg_double (lden, hden, &lden, &hden); | |
467 | } | |
468 | if (hnum < 0) | |
469 | { | |
470 | quo_neg = ~ quo_neg; | |
471 | neg_double (lnum, hnum, &lnum, &hnum); | |
472 | } | |
473 | } | |
474 | ||
475 | if (hnum == 0 && hden == 0) | |
476 | { /* single precision */ | |
477 | *hquo = *hrem = 0; | |
478 | *lquo = lnum / lden; /* rounds toward zero since positive args */ | |
479 | goto finish_up; | |
480 | } | |
481 | ||
482 | if (hnum == 0) | |
483 | { /* trivial case: dividend < divisor */ | |
484 | /* hden != 0 already checked. */ | |
485 | *hquo = *lquo = 0; | |
486 | *hrem = hnum; | |
487 | *lrem = lnum; | |
488 | goto finish_up; | |
489 | } | |
490 | ||
491 | bzero (quo, sizeof quo); | |
492 | ||
493 | bzero (num, sizeof num); /* to zero 9th element */ | |
494 | bzero (den, sizeof den); | |
495 | ||
496 | encode (num, lnum, hnum); | |
497 | encode (den, lden, hden); | |
498 | ||
499 | /* This code requires more than just hden == 0. | |
500 | We also have to require that we don't need more than three bytes | |
501 | to hold CARRY. If we ever did need four bytes to hold it, we | |
502 | would lose part of it when computing WORK on the next round. */ | |
503 | if (hden == 0 && ((lden << 8) >> 8) == lden) | |
504 | { /* simpler algorithm */ | |
505 | /* hnum != 0 already checked. */ | |
506 | for (i = 7; i >= 0; i--) | |
507 | { | |
508 | work = num[i] + (carry << 8); | |
509 | quo[i] = work / lden; | |
510 | carry = work % lden; | |
511 | } | |
512 | } | |
513 | else { /* full double precision, | |
514 | with thanks to Don Knuth's | |
6dc42e49 | 515 | "Seminumerical Algorithms". */ |
6d716ca8 RS |
516 | #define BASE 256 |
517 | int quo_est, scale, num_hi_sig, den_hi_sig, quo_hi_sig; | |
518 | ||
519 | /* Find the highest non-zero divisor digit. */ | |
520 | for (i = 7; ; i--) | |
521 | if (den[i] != 0) { | |
522 | den_hi_sig = i; | |
523 | break; | |
524 | } | |
525 | for (i = 7; ; i--) | |
526 | if (num[i] != 0) { | |
527 | num_hi_sig = i; | |
528 | break; | |
529 | } | |
530 | quo_hi_sig = num_hi_sig - den_hi_sig + 1; | |
531 | ||
532 | /* Insure that the first digit of the divisor is at least BASE/2. | |
533 | This is required by the quotient digit estimation algorithm. */ | |
534 | ||
535 | scale = BASE / (den[den_hi_sig] + 1); | |
536 | if (scale > 1) { /* scale divisor and dividend */ | |
537 | carry = 0; | |
538 | for (i = 0; i <= 8; i++) { | |
539 | work = (num[i] * scale) + carry; | |
540 | num[i] = work & 0xff; | |
541 | carry = work >> 8; | |
542 | if (num[i] != 0) num_hi_sig = i; | |
543 | } | |
544 | carry = 0; | |
545 | for (i = 0; i <= 7; i++) { | |
546 | work = (den[i] * scale) + carry; | |
547 | den[i] = work & 0xff; | |
548 | carry = work >> 8; | |
549 | if (den[i] != 0) den_hi_sig = i; | |
550 | } | |
551 | } | |
552 | ||
553 | /* Main loop */ | |
554 | for (i = quo_hi_sig; i > 0; i--) { | |
6dc42e49 | 555 | /* guess the next quotient digit, quo_est, by dividing the first |
6d716ca8 RS |
556 | two remaining dividend digits by the high order quotient digit. |
557 | quo_est is never low and is at most 2 high. */ | |
558 | ||
559 | int num_hi; /* index of highest remaining dividend digit */ | |
560 | ||
561 | num_hi = i + den_hi_sig; | |
562 | ||
563 | work = (num[num_hi] * BASE) + (num_hi > 0 ? num[num_hi - 1] : 0); | |
564 | if (num[num_hi] != den[den_hi_sig]) { | |
565 | quo_est = work / den[den_hi_sig]; | |
566 | } | |
567 | else { | |
568 | quo_est = BASE - 1; | |
569 | } | |
570 | ||
571 | /* refine quo_est so it's usually correct, and at most one high. */ | |
572 | while ((den[den_hi_sig - 1] * quo_est) | |
573 | > (((work - (quo_est * den[den_hi_sig])) * BASE) | |
574 | + ((num_hi - 1) > 0 ? num[num_hi - 2] : 0))) | |
575 | quo_est--; | |
576 | ||
577 | /* Try QUO_EST as the quotient digit, by multiplying the | |
578 | divisor by QUO_EST and subtracting from the remaining dividend. | |
579 | Keep in mind that QUO_EST is the I - 1st digit. */ | |
580 | ||
581 | carry = 0; | |
582 | ||
583 | for (j = 0; j <= den_hi_sig; j++) | |
584 | { | |
585 | int digit; | |
586 | ||
587 | work = num[i + j - 1] - (quo_est * den[j]) + carry; | |
588 | digit = work & 0xff; | |
589 | carry = work >> 8; | |
590 | if (digit < 0) | |
591 | { | |
592 | digit += BASE; | |
593 | carry--; | |
594 | } | |
595 | num[i + j - 1] = digit; | |
596 | } | |
597 | ||
598 | /* if quo_est was high by one, then num[i] went negative and | |
599 | we need to correct things. */ | |
600 | ||
601 | if (num[num_hi] < 0) | |
602 | { | |
603 | quo_est--; | |
604 | carry = 0; /* add divisor back in */ | |
605 | for (j = 0; j <= den_hi_sig; j++) | |
606 | { | |
607 | work = num[i + j - 1] + den[j] + carry; | |
608 | if (work > BASE) | |
609 | { | |
610 | work -= BASE; | |
611 | carry = 1; | |
612 | } | |
613 | else | |
614 | { | |
615 | carry = 0; | |
616 | } | |
617 | num[i + j - 1] = work; | |
618 | } | |
619 | num [num_hi] += carry; | |
620 | } | |
621 | ||
622 | /* store the quotient digit. */ | |
623 | quo[i - 1] = quo_est; | |
624 | } | |
625 | } | |
626 | ||
627 | decode (quo, lquo, hquo); | |
628 | ||
629 | finish_up: | |
630 | /* if result is negative, make it so. */ | |
631 | if (quo_neg) | |
632 | neg_double (*lquo, *hquo, lquo, hquo); | |
633 | ||
634 | /* compute trial remainder: rem = num - (quo * den) */ | |
635 | mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem); | |
636 | neg_double (*lrem, *hrem, lrem, hrem); | |
637 | add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem); | |
638 | ||
639 | switch (code) | |
640 | { | |
641 | case TRUNC_DIV_EXPR: | |
642 | case TRUNC_MOD_EXPR: /* round toward zero */ | |
643 | case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */ | |
644 | return; | |
645 | ||
646 | case FLOOR_DIV_EXPR: | |
647 | case FLOOR_MOD_EXPR: /* round toward negative infinity */ | |
648 | if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */ | |
649 | { | |
650 | /* quo = quo - 1; */ | |
651 | add_double (*lquo, *hquo, -1, -1, lquo, hquo); | |
652 | } | |
653 | else return; | |
654 | break; | |
655 | ||
656 | case CEIL_DIV_EXPR: | |
657 | case CEIL_MOD_EXPR: /* round toward positive infinity */ | |
658 | if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */ | |
659 | { | |
660 | add_double (*lquo, *hquo, 1, 0, lquo, hquo); | |
661 | } | |
662 | else return; | |
663 | break; | |
664 | ||
665 | case ROUND_DIV_EXPR: | |
666 | case ROUND_MOD_EXPR: /* round to closest integer */ | |
667 | { | |
668 | int labs_rem = *lrem, habs_rem = *hrem; | |
669 | int labs_den = lden, habs_den = hden, ltwice, htwice; | |
670 | ||
671 | /* get absolute values */ | |
672 | if (*hrem < 0) neg_double (*lrem, *hrem, &labs_rem, &habs_rem); | |
673 | if (hden < 0) neg_double (lden, hden, &labs_den, &habs_den); | |
674 | ||
675 | /* if (2 * abs (lrem) >= abs (lden)) */ | |
676 | mul_double (2, 0, labs_rem, habs_rem, <wice, &htwice); | |
677 | if (((unsigned) habs_den < (unsigned) htwice) | |
678 | || (((unsigned) habs_den == (unsigned) htwice) | |
679 | && ((unsigned) labs_den < (unsigned) ltwice))) | |
680 | { | |
681 | if (*hquo < 0) | |
682 | /* quo = quo - 1; */ | |
683 | add_double (*lquo, *hquo, -1, -1, lquo, hquo); | |
684 | else | |
685 | /* quo = quo + 1; */ | |
686 | add_double (*lquo, *hquo, 1, 0, lquo, hquo); | |
687 | } | |
688 | else return; | |
689 | } | |
690 | break; | |
691 | ||
692 | default: | |
693 | abort (); | |
694 | } | |
695 | ||
696 | /* compute true remainder: rem = num - (quo * den) */ | |
697 | mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem); | |
698 | neg_double (*lrem, *hrem, lrem, hrem); | |
699 | add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem); | |
700 | } | |
701 | \f | |
702 | #if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT | |
703 | ||
704 | /* Check for infinity in an IEEE double precision number. */ | |
705 | ||
706 | int | |
707 | target_isinf (x) | |
708 | REAL_VALUE_TYPE x; | |
709 | { | |
710 | /* The IEEE 64-bit double format. */ | |
711 | union { | |
712 | REAL_VALUE_TYPE d; | |
713 | struct { | |
714 | unsigned sign : 1; | |
715 | unsigned exponent : 11; | |
716 | unsigned mantissa1 : 20; | |
717 | unsigned mantissa2; | |
718 | } little_endian; | |
719 | struct { | |
720 | unsigned mantissa2; | |
721 | unsigned mantissa1 : 20; | |
722 | unsigned exponent : 11; | |
723 | unsigned sign : 1; | |
724 | } big_endian; | |
725 | } u; | |
726 | ||
727 | u.d = dconstm1; | |
728 | if (u.big_endian.sign == 1) | |
729 | { | |
730 | u.d = x; | |
731 | return (u.big_endian.exponent == 2047 | |
732 | && u.big_endian.mantissa1 == 0 | |
733 | && u.big_endian.mantissa2 == 0); | |
734 | } | |
735 | else | |
736 | { | |
737 | u.d = x; | |
738 | return (u.little_endian.exponent == 2047 | |
739 | && u.little_endian.mantissa1 == 0 | |
740 | && u.little_endian.mantissa2 == 0); | |
741 | } | |
742 | } | |
743 | ||
7d4d4d22 RS |
744 | /* Check whether an IEEE double precision number is a NaN. */ |
745 | ||
746 | int | |
747 | target_isnan (x) | |
748 | REAL_VALUE_TYPE x; | |
749 | { | |
750 | /* The IEEE 64-bit double format. */ | |
751 | union { | |
752 | REAL_VALUE_TYPE d; | |
753 | struct { | |
754 | unsigned sign : 1; | |
755 | unsigned exponent : 11; | |
756 | unsigned mantissa1 : 20; | |
757 | unsigned mantissa2; | |
758 | } little_endian; | |
759 | struct { | |
760 | unsigned mantissa2; | |
761 | unsigned mantissa1 : 20; | |
762 | unsigned exponent : 11; | |
763 | unsigned sign : 1; | |
764 | } big_endian; | |
765 | } u; | |
766 | ||
767 | u.d = dconstm1; | |
768 | if (u.big_endian.sign == 1) | |
769 | { | |
770 | u.d = x; | |
771 | return (u.big_endian.exponent == 2047 | |
772 | && (u.big_endian.mantissa1 != 0 | |
773 | || u.big_endian.mantissa2 != 0)); | |
774 | } | |
775 | else | |
776 | { | |
777 | u.d = x; | |
778 | return (u.little_endian.exponent == 2047 | |
779 | && (u.little_endian.mantissa1 != 0 | |
780 | || u.little_endian.mantissa2 != 0)); | |
781 | } | |
782 | } | |
783 | ||
c05a9b68 | 784 | /* Check for a negative IEEE double precision number. */ |
6d716ca8 RS |
785 | |
786 | int | |
c05a9b68 | 787 | target_negative (x) |
6d716ca8 RS |
788 | REAL_VALUE_TYPE x; |
789 | { | |
c05a9b68 RS |
790 | /* The IEEE 64-bit double format. */ |
791 | union { | |
792 | REAL_VALUE_TYPE d; | |
793 | struct { | |
794 | unsigned sign : 1; | |
795 | unsigned exponent : 11; | |
796 | unsigned mantissa1 : 20; | |
797 | unsigned mantissa2; | |
798 | } little_endian; | |
799 | struct { | |
800 | unsigned mantissa2; | |
801 | unsigned mantissa1 : 20; | |
802 | unsigned exponent : 11; | |
803 | unsigned sign : 1; | |
804 | } big_endian; | |
805 | } u; | |
6d716ca8 | 806 | |
c05a9b68 RS |
807 | u.d = dconstm1; |
808 | if (u.big_endian.sign == 1) | |
809 | { | |
810 | u.d = x; | |
811 | return u.big_endian.sign; | |
812 | } | |
813 | else | |
814 | { | |
815 | u.d = x; | |
816 | return u.little_endian.sign; | |
817 | } | |
6d716ca8 RS |
818 | } |
819 | #else /* Target not IEEE */ | |
820 | ||
821 | /* Let's assume other float formats don't have infinity. | |
822 | (This can be overridden by redefining REAL_VALUE_ISINF.) */ | |
823 | ||
824 | target_isinf (x) | |
825 | REAL_VALUE_TYPE x; | |
826 | { | |
827 | return 0; | |
828 | } | |
829 | ||
7d4d4d22 RS |
830 | /* Let's assume other float formats don't have NaNs. |
831 | (This can be overridden by redefining REAL_VALUE_ISNAN.) */ | |
832 | ||
833 | target_isnan (x) | |
834 | REAL_VALUE_TYPE x; | |
835 | { | |
836 | return 0; | |
837 | } | |
838 | ||
6d716ca8 | 839 | /* Let's assume other float formats don't have minus zero. |
c05a9b68 | 840 | (This can be overridden by redefining REAL_VALUE_NEGATIVE.) */ |
6d716ca8 | 841 | |
c05a9b68 | 842 | target_negative (x) |
6d716ca8 RS |
843 | REAL_VALUE_TYPE x; |
844 | { | |
c05a9b68 | 845 | return x < 0; |
6d716ca8 RS |
846 | } |
847 | #endif /* Target not IEEE */ | |
848 | \f | |
849 | /* Split a tree IN into a constant and a variable part | |
850 | that could be combined with CODE to make IN. | |
851 | CODE must be a commutative arithmetic operation. | |
852 | Store the constant part into *CONP and the variable in &VARP. | |
853 | Return 1 if this was done; zero means the tree IN did not decompose | |
854 | this way. | |
855 | ||
856 | If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. | |
857 | Therefore, we must tell the caller whether the variable part | |
858 | was subtracted. We do this by storing 1 or -1 into *VARSIGNP. | |
859 | The value stored is the coefficient for the variable term. | |
860 | The constant term we return should always be added; | |
861 | we negate it if necessary. */ | |
862 | ||
863 | static int | |
864 | split_tree (in, code, varp, conp, varsignp) | |
865 | tree in; | |
866 | enum tree_code code; | |
867 | tree *varp, *conp; | |
868 | int *varsignp; | |
869 | { | |
870 | register tree outtype = TREE_TYPE (in); | |
871 | *varp = 0; | |
872 | *conp = 0; | |
873 | ||
874 | /* Strip any conversions that don't change the machine mode. */ | |
875 | while ((TREE_CODE (in) == NOP_EXPR | |
876 | || TREE_CODE (in) == CONVERT_EXPR) | |
877 | && (TYPE_MODE (TREE_TYPE (in)) | |
878 | == TYPE_MODE (TREE_TYPE (TREE_OPERAND (in, 0))))) | |
879 | in = TREE_OPERAND (in, 0); | |
880 | ||
881 | if (TREE_CODE (in) == code | |
882 | || (TREE_CODE (TREE_TYPE (in)) != REAL_TYPE | |
883 | /* We can associate addition and subtraction together | |
884 | (even though the C standard doesn't say so) | |
885 | for integers because the value is not affected. | |
886 | For reals, the value might be affected, so we can't. */ | |
887 | && | |
888 | ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR) | |
889 | || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR)))) | |
890 | { | |
891 | enum tree_code code = TREE_CODE (TREE_OPERAND (in, 0)); | |
892 | if (code == INTEGER_CST) | |
893 | { | |
894 | *conp = TREE_OPERAND (in, 0); | |
895 | *varp = TREE_OPERAND (in, 1); | |
896 | if (TYPE_MODE (TREE_TYPE (*varp)) != TYPE_MODE (outtype) | |
897 | && TREE_TYPE (*varp) != outtype) | |
898 | *varp = convert (outtype, *varp); | |
899 | *varsignp = (TREE_CODE (in) == MINUS_EXPR) ? -1 : 1; | |
900 | return 1; | |
901 | } | |
902 | if (TREE_CONSTANT (TREE_OPERAND (in, 1))) | |
903 | { | |
904 | *conp = TREE_OPERAND (in, 1); | |
905 | *varp = TREE_OPERAND (in, 0); | |
906 | *varsignp = 1; | |
907 | if (TYPE_MODE (TREE_TYPE (*varp)) != TYPE_MODE (outtype) | |
908 | && TREE_TYPE (*varp) != outtype) | |
909 | *varp = convert (outtype, *varp); | |
910 | if (TREE_CODE (in) == MINUS_EXPR) | |
911 | { | |
912 | /* If operation is subtraction and constant is second, | |
913 | must negate it to get an additive constant. | |
914 | And this cannot be done unless it is a manifest constant. | |
915 | It could also be the address of a static variable. | |
916 | We cannot negate that, so give up. */ | |
917 | if (TREE_CODE (*conp) == INTEGER_CST) | |
918 | /* Subtracting from integer_zero_node loses for long long. */ | |
919 | *conp = fold (build1 (NEGATE_EXPR, TREE_TYPE (*conp), *conp)); | |
920 | else | |
921 | return 0; | |
922 | } | |
923 | return 1; | |
924 | } | |
925 | if (TREE_CONSTANT (TREE_OPERAND (in, 0))) | |
926 | { | |
927 | *conp = TREE_OPERAND (in, 0); | |
928 | *varp = TREE_OPERAND (in, 1); | |
929 | if (TYPE_MODE (TREE_TYPE (*varp)) != TYPE_MODE (outtype) | |
930 | && TREE_TYPE (*varp) != outtype) | |
931 | *varp = convert (outtype, *varp); | |
932 | *varsignp = (TREE_CODE (in) == MINUS_EXPR) ? -1 : 1; | |
933 | return 1; | |
934 | } | |
935 | } | |
936 | return 0; | |
937 | } | |
938 | \f | |
939 | /* Combine two constants NUM and ARG2 under operation CODE | |
940 | to produce a new constant. | |
941 | We assume ARG1 and ARG2 have the same data type, | |
942 | or at least are the same kind of constant and the same machine mode. */ | |
943 | ||
6d716ca8 RS |
944 | static tree |
945 | const_binop (code, arg1, arg2) | |
946 | enum tree_code code; | |
947 | register tree arg1, arg2; | |
948 | { | |
949 | if (TREE_CODE (arg1) == INTEGER_CST) | |
950 | { | |
951 | register int int1l = TREE_INT_CST_LOW (arg1); | |
952 | register int int1h = TREE_INT_CST_HIGH (arg1); | |
953 | int int2l = TREE_INT_CST_LOW (arg2); | |
954 | int int2h = TREE_INT_CST_HIGH (arg2); | |
955 | int low, hi; | |
956 | int garbagel, garbageh; | |
957 | register tree t; | |
958 | int uns = TREE_UNSIGNED (TREE_TYPE (arg1)); | |
959 | ||
960 | switch (code) | |
961 | { | |
962 | case BIT_IOR_EXPR: | |
963 | t = build_int_2 (int1l | int2l, int1h | int2h); | |
964 | break; | |
965 | ||
966 | case BIT_XOR_EXPR: | |
967 | t = build_int_2 (int1l ^ int2l, int1h ^ int2h); | |
968 | break; | |
969 | ||
970 | case BIT_AND_EXPR: | |
971 | t = build_int_2 (int1l & int2l, int1h & int2h); | |
972 | break; | |
973 | ||
974 | case BIT_ANDTC_EXPR: | |
975 | t = build_int_2 (int1l & ~int2l, int1h & ~int2h); | |
976 | break; | |
977 | ||
978 | case RSHIFT_EXPR: | |
979 | int2l = - int2l; | |
980 | case LSHIFT_EXPR: | |
981 | lshift_double (int1l, int1h, int2l, | |
982 | TYPE_PRECISION (TREE_TYPE (arg1)), | |
983 | &low, &hi, | |
984 | !uns); | |
985 | t = build_int_2 (low, hi); | |
986 | break; | |
987 | ||
988 | case RROTATE_EXPR: | |
989 | int2l = - int2l; | |
990 | case LROTATE_EXPR: | |
991 | lrotate_double (int1l, int1h, int2l, | |
992 | TYPE_PRECISION (TREE_TYPE (arg1)), | |
993 | &low, &hi); | |
994 | t = build_int_2 (low, hi); | |
995 | break; | |
996 | ||
997 | case PLUS_EXPR: | |
998 | if (int1h == 0) | |
999 | { | |
1000 | int2l += int1l; | |
1001 | if ((unsigned) int2l < int1l) | |
1002 | int2h += 1; | |
1003 | t = build_int_2 (int2l, int2h); | |
1004 | break; | |
1005 | } | |
1006 | if (int2h == 0) | |
1007 | { | |
1008 | int1l += int2l; | |
1009 | if ((unsigned) int1l < int2l) | |
1010 | int1h += 1; | |
1011 | t = build_int_2 (int1l, int1h); | |
1012 | break; | |
1013 | } | |
1014 | add_double (int1l, int1h, int2l, int2h, &low, &hi); | |
1015 | t = build_int_2 (low, hi); | |
1016 | break; | |
1017 | ||
1018 | case MINUS_EXPR: | |
1019 | if (int2h == 0 && int2l == 0) | |
1020 | { | |
1021 | t = build_int_2 (int1l, int1h); | |
1022 | break; | |
1023 | } | |
1024 | neg_double (int2l, int2h, &int2l, &int2h); | |
1025 | add_double (int1l, int1h, int2l, int2h, &low, &hi); | |
1026 | t = build_int_2 (low, hi); | |
1027 | break; | |
1028 | ||
1029 | case MULT_EXPR: | |
1030 | /* Optimize simple cases. */ | |
1031 | if (int1h == 0) | |
1032 | { | |
1033 | unsigned temp; | |
1034 | ||
1035 | switch (int1l) | |
1036 | { | |
1037 | case 0: | |
1038 | t = build_int_2 (0, 0); | |
1039 | goto got_it; | |
1040 | case 1: | |
1041 | t = build_int_2 (int2l, int2h); | |
1042 | goto got_it; | |
1043 | case 2: | |
1044 | temp = int2l + int2l; | |
1045 | int2h = int2h * 2 + (temp < int2l); | |
1046 | t = build_int_2 (temp, int2h); | |
1047 | goto got_it; | |
1048 | case 3: | |
1049 | temp = int2l + int2l + int2l; | |
1050 | int2h = int2h * 3 + (temp < int2l); | |
1051 | t = build_int_2 (temp, int2h); | |
1052 | goto got_it; | |
1053 | case 4: | |
1054 | temp = int2l + int2l; | |
1055 | int2h = int2h * 4 + ((temp < int2l) << 1); | |
1056 | int2l = temp; | |
1057 | temp += temp; | |
1058 | int2h += (temp < int2l); | |
1059 | t = build_int_2 (temp, int2h); | |
1060 | goto got_it; | |
1061 | case 8: | |
1062 | temp = int2l + int2l; | |
1063 | int2h = int2h * 8 + ((temp < int2l) << 2); | |
1064 | int2l = temp; | |
1065 | temp += temp; | |
1066 | int2h += (temp < int2l) << 1; | |
1067 | int2l = temp; | |
1068 | temp += temp; | |
1069 | int2h += (temp < int2l); | |
1070 | t = build_int_2 (temp, int2h); | |
1071 | goto got_it; | |
1072 | default: | |
1073 | break; | |
1074 | } | |
1075 | } | |
1076 | ||
1077 | if (int2h == 0) | |
1078 | { | |
1079 | if (int2l == 0) | |
1080 | { | |
1081 | t = build_int_2 (0, 0); | |
1082 | break; | |
1083 | } | |
1084 | if (int2l == 1) | |
1085 | { | |
1086 | t = build_int_2 (int1l, int1h); | |
1087 | break; | |
1088 | } | |
1089 | } | |
1090 | ||
1091 | mul_double (int1l, int1h, int2l, int2h, &low, &hi); | |
1092 | t = build_int_2 (low, hi); | |
1093 | break; | |
1094 | ||
1095 | case TRUNC_DIV_EXPR: | |
1096 | case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR: | |
1097 | case EXACT_DIV_EXPR: | |
1098 | /* This is a shortcut for a common special case. | |
1099 | It reduces the number of tree nodes generated | |
1100 | and saves time. */ | |
1101 | if (int2h == 0 && int2l > 0 | |
1102 | && TREE_TYPE (arg1) == sizetype | |
1103 | && int1h == 0 && int1l >= 0) | |
1104 | { | |
1105 | if (code == CEIL_DIV_EXPR) | |
1106 | int1l += int2l-1; | |
1107 | return size_int (int1l / int2l); | |
1108 | } | |
1109 | case ROUND_DIV_EXPR: | |
1110 | if (int2h == 0 && int2l == 1) | |
1111 | { | |
1112 | t = build_int_2 (int1l, int1h); | |
1113 | break; | |
1114 | } | |
1115 | if (int1l == int2l && int1h == int2h) | |
1116 | { | |
1117 | if ((int1l | int1h) == 0) | |
1118 | abort (); | |
1119 | t = build_int_2 (1, 0); | |
1120 | break; | |
1121 | } | |
1122 | div_and_round_double (code, uns, int1l, int1h, int2l, int2h, | |
1123 | &low, &hi, &garbagel, &garbageh); | |
1124 | t = build_int_2 (low, hi); | |
1125 | break; | |
1126 | ||
1127 | case TRUNC_MOD_EXPR: case ROUND_MOD_EXPR: | |
1128 | case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR: | |
1129 | div_and_round_double (code, uns, int1l, int1h, int2l, int2h, | |
1130 | &garbagel, &garbageh, &low, &hi); | |
1131 | t = build_int_2 (low, hi); | |
1132 | break; | |
1133 | ||
1134 | case MIN_EXPR: | |
1135 | case MAX_EXPR: | |
1136 | if (uns) | |
1137 | { | |
1138 | low = (((unsigned) int1h < (unsigned) int2h) | |
1139 | || (((unsigned) int1h == (unsigned) int2h) | |
1140 | && ((unsigned) int1l < (unsigned) int2l))); | |
1141 | } | |
1142 | else | |
1143 | { | |
1144 | low = ((int1h < int2h) | |
1145 | || ((int1h == int2h) | |
1146 | && ((unsigned) int1l < (unsigned) int2l))); | |
1147 | } | |
1148 | if (low == (code == MIN_EXPR)) | |
1149 | t = build_int_2 (int1l, int1h); | |
1150 | else | |
1151 | t = build_int_2 (int2l, int2h); | |
1152 | break; | |
1153 | ||
1154 | default: | |
1155 | abort (); | |
1156 | } | |
1157 | got_it: | |
1158 | TREE_TYPE (t) = TREE_TYPE (arg1); | |
1159 | force_fit_type (t); | |
1160 | return t; | |
1161 | } | |
1162 | #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) | |
1163 | if (TREE_CODE (arg1) == REAL_CST) | |
1164 | { | |
1165 | register REAL_VALUE_TYPE d1; | |
1166 | register REAL_VALUE_TYPE d2; | |
1167 | register REAL_VALUE_TYPE value; | |
7c7b029d | 1168 | tree t; |
6d716ca8 RS |
1169 | |
1170 | d1 = TREE_REAL_CST (arg1); | |
1171 | d2 = TREE_REAL_CST (arg2); | |
7c7b029d | 1172 | if (setjmp (float_error)) |
6d716ca8 RS |
1173 | { |
1174 | warning ("floating overflow in constant folding"); | |
1175 | return build (code, TREE_TYPE (arg1), arg1, arg2); | |
1176 | } | |
7c7b029d | 1177 | set_float_handler (float_error); |
6d716ca8 RS |
1178 | |
1179 | #ifdef REAL_ARITHMETIC | |
1180 | REAL_ARITHMETIC (value, code, d1, d2); | |
1181 | #else | |
1182 | switch (code) | |
1183 | { | |
1184 | case PLUS_EXPR: | |
1185 | value = d1 + d2; | |
1186 | break; | |
1187 | ||
1188 | case MINUS_EXPR: | |
1189 | value = d1 - d2; | |
1190 | break; | |
1191 | ||
1192 | case MULT_EXPR: | |
1193 | value = d1 * d2; | |
1194 | break; | |
1195 | ||
1196 | case RDIV_EXPR: | |
1197 | #ifndef REAL_INFINITY | |
1198 | if (d2 == 0) | |
1199 | abort (); | |
1200 | #endif | |
1201 | ||
1202 | value = d1 / d2; | |
1203 | break; | |
1204 | ||
1205 | case MIN_EXPR: | |
1206 | value = MIN (d1, d2); | |
1207 | break; | |
1208 | ||
1209 | case MAX_EXPR: | |
1210 | value = MAX (d1, d2); | |
1211 | break; | |
1212 | ||
1213 | default: | |
1214 | abort (); | |
1215 | } | |
1216 | #endif /* no REAL_ARITHMETIC */ | |
7c7b029d RS |
1217 | t = build_real (TREE_TYPE (arg1), |
1218 | REAL_VALUE_TRUNCATE (TYPE_MODE (TREE_TYPE (arg1)), value)); | |
6d716ca8 | 1219 | set_float_handler (0); |
7c7b029d | 1220 | return t; |
6d716ca8 RS |
1221 | } |
1222 | #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */ | |
1223 | if (TREE_CODE (arg1) == COMPLEX_CST) | |
1224 | { | |
1225 | register tree r1 = TREE_REALPART (arg1); | |
1226 | register tree i1 = TREE_IMAGPART (arg1); | |
1227 | register tree r2 = TREE_REALPART (arg2); | |
1228 | register tree i2 = TREE_IMAGPART (arg2); | |
1229 | register tree t; | |
1230 | ||
1231 | switch (code) | |
1232 | { | |
1233 | case PLUS_EXPR: | |
1234 | t = build_complex (const_binop (PLUS_EXPR, r1, r2), | |
1235 | const_binop (PLUS_EXPR, i1, i2)); | |
1236 | break; | |
1237 | ||
1238 | case MINUS_EXPR: | |
1239 | t = build_complex (const_binop (MINUS_EXPR, r1, r2), | |
1240 | const_binop (MINUS_EXPR, i1, i2)); | |
1241 | break; | |
1242 | ||
1243 | case MULT_EXPR: | |
1244 | t = build_complex (const_binop (MINUS_EXPR, | |
1245 | const_binop (MULT_EXPR, r1, r2), | |
1246 | const_binop (MULT_EXPR, i1, i2)), | |
1247 | const_binop (PLUS_EXPR, | |
1248 | const_binop (MULT_EXPR, r1, i2), | |
1249 | const_binop (MULT_EXPR, i1, r2))); | |
1250 | break; | |
1251 | ||
1252 | case RDIV_EXPR: | |
1253 | { | |
1254 | register tree magsquared | |
1255 | = const_binop (PLUS_EXPR, | |
1256 | const_binop (MULT_EXPR, r2, r2), | |
1257 | const_binop (MULT_EXPR, i2, i2)); | |
1258 | t = build_complex (const_binop (RDIV_EXPR, | |
1259 | const_binop (PLUS_EXPR, | |
1260 | const_binop (MULT_EXPR, r1, r2), | |
1261 | const_binop (MULT_EXPR, i1, i2)), | |
1262 | magsquared), | |
1263 | const_binop (RDIV_EXPR, | |
1264 | const_binop (MINUS_EXPR, | |
1265 | const_binop (MULT_EXPR, i1, r2), | |
1266 | const_binop (MULT_EXPR, r1, i2)), | |
1267 | magsquared)); | |
1268 | } | |
1269 | break; | |
1270 | ||
1271 | default: | |
1272 | abort (); | |
1273 | } | |
1274 | TREE_TYPE (t) = TREE_TYPE (arg1); | |
1275 | return t; | |
1276 | } | |
1277 | return 0; | |
1278 | } | |
1279 | \f | |
1280 | /* Return an INTEGER_CST with value V and type from `sizetype'. */ | |
1281 | ||
1282 | tree | |
1283 | size_int (number) | |
1284 | unsigned int number; | |
1285 | { | |
1286 | register tree t; | |
1287 | /* Type-size nodes already made for small sizes. */ | |
1288 | static tree size_table[2*HOST_BITS_PER_INT+1]; | |
1289 | ||
1290 | if (number >= 0 && number < 2*HOST_BITS_PER_INT+1 && size_table[number] != 0) | |
1291 | return size_table[number]; | |
1292 | if (number >= 0 && number < 2*HOST_BITS_PER_INT+1) | |
1293 | { | |
6d716ca8 RS |
1294 | push_obstacks_nochange (); |
1295 | /* Make this a permanent node. */ | |
c05a9b68 | 1296 | end_temporary_allocation (); |
6d716ca8 RS |
1297 | t = build_int_2 (number, 0); |
1298 | TREE_TYPE (t) = sizetype; | |
1299 | size_table[number] = t; | |
1300 | pop_obstacks (); | |
1301 | } | |
1302 | else | |
1303 | { | |
1304 | t = build_int_2 (number, 0); | |
1305 | TREE_TYPE (t) = sizetype; | |
1306 | } | |
1307 | return t; | |
1308 | } | |
1309 | ||
1310 | /* Combine operands OP1 and OP2 with arithmetic operation CODE. | |
1311 | CODE is a tree code. Data type is taken from `sizetype', | |
1312 | If the operands are constant, so is the result. */ | |
1313 | ||
1314 | tree | |
1315 | size_binop (code, arg0, arg1) | |
1316 | enum tree_code code; | |
1317 | tree arg0, arg1; | |
1318 | { | |
1319 | /* Handle the special case of two integer constants faster. */ | |
1320 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST) | |
1321 | { | |
1322 | /* And some specific cases even faster than that. */ | |
1323 | if (code == PLUS_EXPR | |
1324 | && TREE_INT_CST_LOW (arg0) == 0 | |
1325 | && TREE_INT_CST_HIGH (arg0) == 0) | |
1326 | return arg1; | |
1327 | if (code == MINUS_EXPR | |
1328 | && TREE_INT_CST_LOW (arg1) == 0 | |
1329 | && TREE_INT_CST_HIGH (arg1) == 0) | |
1330 | return arg0; | |
1331 | if (code == MULT_EXPR | |
1332 | && TREE_INT_CST_LOW (arg0) == 1 | |
1333 | && TREE_INT_CST_HIGH (arg0) == 0) | |
1334 | return arg1; | |
1335 | /* Handle general case of two integer constants. */ | |
1336 | return const_binop (code, arg0, arg1); | |
1337 | } | |
1338 | ||
1339 | if (arg0 == error_mark_node || arg1 == error_mark_node) | |
1340 | return error_mark_node; | |
1341 | ||
1342 | return fold (build (code, sizetype, arg0, arg1)); | |
1343 | } | |
1344 | \f | |
1345 | /* Given T, a tree representing type conversion of ARG1, a constant, | |
1346 | return a constant tree representing the result of conversion. */ | |
1347 | ||
1348 | static tree | |
1349 | fold_convert (t, arg1) | |
1350 | register tree t; | |
1351 | register tree arg1; | |
1352 | { | |
1353 | register tree type = TREE_TYPE (t); | |
1354 | ||
1355 | if (TREE_CODE (type) == POINTER_TYPE | |
1356 | || TREE_CODE (type) == INTEGER_TYPE | |
1357 | || TREE_CODE (type) == ENUMERAL_TYPE) | |
1358 | { | |
1359 | if (TREE_CODE (arg1) == INTEGER_CST) | |
1360 | { | |
1361 | /* Given an integer constant, make new constant with new type, | |
1362 | appropriately sign-extended or truncated. */ | |
1363 | t = build_int_2 (TREE_INT_CST_LOW (arg1), | |
1364 | TREE_INT_CST_HIGH (arg1)); | |
1365 | TREE_TYPE (t) = type; | |
1366 | force_fit_type (t); | |
1367 | } | |
1368 | #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) | |
1369 | else if (TREE_CODE (arg1) == REAL_CST) | |
1370 | { | |
c05a9b68 RS |
1371 | REAL_VALUE_TYPE |
1372 | l = real_value_from_int_cst (TYPE_MIN_VALUE (type)), | |
1373 | x = TREE_REAL_CST (arg1), | |
1374 | u = real_value_from_int_cst (TYPE_MAX_VALUE (type)); | |
1375 | if (! ((REAL_VALUES_LESS (l, x) || REAL_VALUES_EQUAL (l, x)) | |
1376 | && (REAL_VALUES_LESS (x, u) || REAL_VALUES_EQUAL (x, u)))) | |
6d716ca8 RS |
1377 | { |
1378 | warning ("real constant out of range for integer conversion"); | |
1379 | return t; | |
1380 | } | |
1381 | #ifndef REAL_ARITHMETIC | |
1382 | { | |
1383 | REAL_VALUE_TYPE d; | |
1384 | int low, high; | |
1385 | int half_word = 1 << (HOST_BITS_PER_INT / 2); | |
1386 | ||
1387 | d = TREE_REAL_CST (arg1); | |
1388 | if (d < 0) | |
1389 | d = -d; | |
1390 | ||
1391 | high = (int) (d / half_word / half_word); | |
1392 | d -= (REAL_VALUE_TYPE) high * half_word * half_word; | |
1393 | low = (unsigned) d; | |
1394 | if (TREE_REAL_CST (arg1) < 0) | |
1395 | neg_double (low, high, &low, &high); | |
1396 | t = build_int_2 (low, high); | |
1397 | } | |
1398 | #else | |
1399 | { | |
1400 | int low, high; | |
1401 | REAL_VALUE_TO_INT (low, high, TREE_REAL_CST (arg1)); | |
1402 | t = build_int_2 (low, high); | |
1403 | } | |
1404 | #endif | |
1405 | TREE_TYPE (t) = type; | |
1406 | force_fit_type (t); | |
1407 | } | |
1408 | #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */ | |
1409 | TREE_TYPE (t) = type; | |
1410 | } | |
1411 | else if (TREE_CODE (type) == REAL_TYPE) | |
1412 | { | |
1413 | #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) | |
1414 | if (TREE_CODE (arg1) == INTEGER_CST) | |
1415 | return build_real_from_int_cst (type, arg1); | |
1416 | #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */ | |
1417 | if (TREE_CODE (arg1) == REAL_CST) | |
7c7b029d RS |
1418 | { |
1419 | if (setjmp (float_error)) | |
1420 | { | |
1421 | warning ("floating overflow in constant folding"); | |
1422 | return t; | |
1423 | } | |
1424 | set_float_handler (float_error); | |
1425 | ||
1426 | t = build_real (type, REAL_VALUE_TRUNCATE (TYPE_MODE (type), | |
1427 | TREE_REAL_CST (arg1))); | |
1428 | set_float_handler (0); | |
1429 | return t; | |
1430 | } | |
6d716ca8 RS |
1431 | } |
1432 | TREE_CONSTANT (t) = 1; | |
1433 | return t; | |
1434 | } | |
1435 | \f | |
1436 | /* Return an expr equal to X but certainly not valid as an lvalue. */ | |
1437 | ||
1438 | tree | |
1439 | non_lvalue (x) | |
1440 | tree x; | |
1441 | { | |
1442 | tree result; | |
1443 | ||
1444 | /* These things are certainly not lvalues. */ | |
1445 | if (TREE_CODE (x) == NON_LVALUE_EXPR | |
1446 | || TREE_CODE (x) == INTEGER_CST | |
1447 | || TREE_CODE (x) == REAL_CST | |
1448 | || TREE_CODE (x) == STRING_CST | |
1449 | || TREE_CODE (x) == ADDR_EXPR) | |
1450 | return x; | |
1451 | ||
1452 | result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x); | |
1453 | TREE_CONSTANT (result) = TREE_CONSTANT (x); | |
1454 | return result; | |
1455 | } | |
c05a9b68 RS |
1456 | \f |
1457 | /* Given a tree comparison code, return the code that is the logical inverse | |
1458 | of the given code. It is not safe to do this for floating-point | |
1459 | comparisons, except for NE_EXPR and EQ_EXPR. */ | |
6d716ca8 | 1460 | |
c05a9b68 RS |
1461 | static enum tree_code |
1462 | invert_tree_comparison (code) | |
1463 | enum tree_code code; | |
1464 | { | |
1465 | switch (code) | |
1466 | { | |
1467 | case EQ_EXPR: | |
1468 | return NE_EXPR; | |
1469 | case NE_EXPR: | |
1470 | return EQ_EXPR; | |
1471 | case GT_EXPR: | |
1472 | return LE_EXPR; | |
1473 | case GE_EXPR: | |
1474 | return LT_EXPR; | |
1475 | case LT_EXPR: | |
1476 | return GE_EXPR; | |
1477 | case LE_EXPR: | |
1478 | return GT_EXPR; | |
1479 | default: | |
1480 | abort (); | |
1481 | } | |
1482 | } | |
1483 | ||
1484 | /* Similar, but return the comparison that results if the operands are | |
1485 | swapped. This is safe for floating-point. */ | |
1486 | ||
1487 | static enum tree_code | |
1488 | swap_tree_comparison (code) | |
1489 | enum tree_code code; | |
1490 | { | |
1491 | switch (code) | |
1492 | { | |
1493 | case EQ_EXPR: | |
1494 | case NE_EXPR: | |
1495 | return code; | |
1496 | case GT_EXPR: | |
1497 | return LT_EXPR; | |
1498 | case GE_EXPR: | |
1499 | return LE_EXPR; | |
1500 | case LT_EXPR: | |
1501 | return GT_EXPR; | |
1502 | case LE_EXPR: | |
1503 | return GE_EXPR; | |
1504 | default: | |
1505 | abort (); | |
1506 | } | |
1507 | } | |
1508 | \f | |
6d716ca8 RS |
1509 | /* Return nonzero if two operands are necessarily equal. |
1510 | If ONLY_CONST is non-zero, only return non-zero for constants. */ | |
1511 | ||
1512 | int | |
1513 | operand_equal_p (arg0, arg1, only_const) | |
1514 | tree arg0, arg1; | |
1515 | int only_const; | |
1516 | { | |
1517 | /* If both types don't have the same signedness, then we can't consider | |
1518 | them equal. We must check this before the STRIP_NOPS calls | |
1519 | because they may change the signedness of the arguments. */ | |
1520 | if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1))) | |
1521 | return 0; | |
1522 | ||
1523 | STRIP_NOPS (arg0); | |
1524 | STRIP_NOPS (arg1); | |
1525 | ||
1526 | /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal. | |
1527 | We don't care about side effects in that case because the SAVE_EXPR | |
1528 | takes care of that for us. */ | |
1529 | if (TREE_CODE (arg0) == SAVE_EXPR && arg0 == arg1) | |
1530 | return ! only_const; | |
1531 | ||
1532 | if (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)) | |
1533 | return 0; | |
1534 | ||
1535 | if (TREE_CODE (arg0) == TREE_CODE (arg1) | |
1536 | && TREE_CODE (arg0) == ADDR_EXPR | |
1537 | && TREE_OPERAND (arg0, 0) == TREE_OPERAND (arg1, 0)) | |
1538 | return 1; | |
1539 | ||
1540 | if (TREE_CODE (arg0) == TREE_CODE (arg1) | |
1541 | && TREE_CODE (arg0) == INTEGER_CST | |
1542 | && TREE_INT_CST_LOW (arg0) == TREE_INT_CST_LOW (arg1) | |
1543 | && TREE_INT_CST_HIGH (arg0) == TREE_INT_CST_HIGH (arg1)) | |
1544 | return 1; | |
1545 | ||
7d4d4d22 RS |
1546 | /* Detect when real constants are equal. |
1547 | But reject weird values because we can't be sure what to do with them. */ | |
6d716ca8 RS |
1548 | if (TREE_CODE (arg0) == TREE_CODE (arg1) |
1549 | && TREE_CODE (arg0) == REAL_CST | |
c05a9b68 RS |
1550 | && !bcmp (&TREE_REAL_CST (arg0), &TREE_REAL_CST (arg1), |
1551 | sizeof (REAL_VALUE_TYPE)) | |
1552 | /* Some people say these are not necessary. | |
1553 | But they do little harm, and taking them out would be risky. | |
1554 | So leave them and let's not spend any more time on them--rms. */ | |
7d4d4d22 RS |
1555 | && !REAL_VALUE_ISINF (TREE_REAL_CST (arg0)) |
1556 | && !REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))) | |
6d716ca8 RS |
1557 | return 1; |
1558 | ||
1559 | if (only_const) | |
1560 | return 0; | |
1561 | ||
1562 | if (arg0 == arg1) | |
1563 | return 1; | |
1564 | ||
1565 | if (TREE_CODE (arg0) != TREE_CODE (arg1)) | |
1566 | return 0; | |
1567 | /* This is needed for conversions and for COMPONENT_REF. | |
1568 | Might as well play it safe and always test this. */ | |
1569 | if (TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1))) | |
1570 | return 0; | |
1571 | ||
1572 | switch (TREE_CODE_CLASS (TREE_CODE (arg0))) | |
1573 | { | |
1574 | case '1': | |
1575 | /* Two conversions are equal only if signedness and modes match. */ | |
1576 | if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR) | |
1577 | && (TREE_UNSIGNED (TREE_TYPE (arg0)) | |
1578 | != TREE_UNSIGNED (TREE_TYPE (arg1)))) | |
1579 | return 0; | |
1580 | ||
1581 | return operand_equal_p (TREE_OPERAND (arg0, 0), | |
1582 | TREE_OPERAND (arg1, 0), 0); | |
1583 | ||
1584 | case '<': | |
1585 | case '2': | |
1586 | return (operand_equal_p (TREE_OPERAND (arg0, 0), | |
1587 | TREE_OPERAND (arg1, 0), 0) | |
1588 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
1589 | TREE_OPERAND (arg1, 1), 0)); | |
1590 | ||
1591 | case 'r': | |
1592 | switch (TREE_CODE (arg0)) | |
1593 | { | |
1594 | case INDIRECT_REF: | |
1595 | return operand_equal_p (TREE_OPERAND (arg0, 0), | |
1596 | TREE_OPERAND (arg1, 0), 0); | |
1597 | ||
1598 | case COMPONENT_REF: | |
1599 | case ARRAY_REF: | |
1600 | return (operand_equal_p (TREE_OPERAND (arg0, 0), | |
1601 | TREE_OPERAND (arg1, 0), 0) | |
1602 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
1603 | TREE_OPERAND (arg1, 1), 0)); | |
1604 | ||
1605 | case BIT_FIELD_REF: | |
1606 | return (operand_equal_p (TREE_OPERAND (arg0, 0), | |
1607 | TREE_OPERAND (arg1, 0), 0) | |
1608 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
1609 | TREE_OPERAND (arg1, 1), 0) | |
1610 | && operand_equal_p (TREE_OPERAND (arg0, 2), | |
1611 | TREE_OPERAND (arg1, 2), 0)); | |
1612 | } | |
1613 | break; | |
1614 | } | |
1615 | ||
1616 | return 0; | |
1617 | } | |
c05a9b68 RS |
1618 | \f |
1619 | /* Similar to operand_equal_p, but see if ARG0 might have been made by | |
1620 | shorten_compare from ARG1 when ARG1 was being compared with OTHER. | |
6d716ca8 | 1621 | |
6d716ca8 RS |
1622 | When in doubt, return 0. */ |
1623 | ||
1624 | static int | |
c05a9b68 RS |
1625 | operand_equal_for_comparison_p (arg0, arg1, other) |
1626 | tree arg0, arg1; | |
1627 | tree other; | |
6d716ca8 | 1628 | { |
c05a9b68 RS |
1629 | int unsignedp1, unsignedpo; |
1630 | tree primarg1, primother; | |
6d716ca8 RS |
1631 | int correct_width; |
1632 | ||
c05a9b68 | 1633 | if (operand_equal_p (arg0, arg1, 0)) |
6d716ca8 RS |
1634 | return 1; |
1635 | ||
c05a9b68 | 1636 | if (TREE_CODE (TREE_TYPE (arg0)) != INTEGER_TYPE) |
6d716ca8 RS |
1637 | return 0; |
1638 | ||
c05a9b68 RS |
1639 | /* Duplicate what shorten_compare does to ARG1 and see if that gives the |
1640 | actual comparison operand, ARG0. | |
6d716ca8 | 1641 | |
c05a9b68 | 1642 | First throw away any conversions to wider types |
6d716ca8 | 1643 | already present in the operands. */ |
6d716ca8 | 1644 | |
c05a9b68 RS |
1645 | primarg1 = get_narrower (arg1, &unsignedp1); |
1646 | primother = get_narrower (other, &unsignedpo); | |
1647 | ||
1648 | correct_width = TYPE_PRECISION (TREE_TYPE (arg1)); | |
1649 | if (unsignedp1 == unsignedpo | |
1650 | && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width | |
1651 | && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width) | |
6d716ca8 | 1652 | { |
c05a9b68 | 1653 | tree type = TREE_TYPE (arg0); |
6d716ca8 RS |
1654 | |
1655 | /* Make sure shorter operand is extended the right way | |
1656 | to match the longer operand. */ | |
c05a9b68 RS |
1657 | primarg1 = convert (signed_or_unsigned_type (unsignedp1, |
1658 | TREE_TYPE (primarg1)), | |
1659 | primarg1); | |
6d716ca8 | 1660 | |
c05a9b68 | 1661 | if (operand_equal_p (arg0, convert (type, primarg1), 0)) |
6d716ca8 RS |
1662 | return 1; |
1663 | } | |
1664 | ||
1665 | return 0; | |
1666 | } | |
1667 | \f | |
c05a9b68 RS |
1668 | /* See if ARG is an expression is either a comparison or is peforming |
1669 | arithmetic on comparisons. The comparisons must only be comparing | |
1670 | two different values, which will be stored in *CVAL1 and *CVAL2; if | |
1671 | they are non-zero it means that some operands have already been found. | |
1672 | No variables may be used anywhere else in the expression except in the | |
1673 | comparisons. | |
1674 | ||
1675 | If this is true, return 1. Otherwise, return zero. */ | |
1676 | ||
1677 | static int | |
1678 | twoval_comparison_p (arg, cval1, cval2) | |
1679 | tree arg; | |
1680 | tree *cval1, *cval2; | |
1681 | { | |
1682 | enum tree_code code = TREE_CODE (arg); | |
1683 | char class = TREE_CODE_CLASS (code); | |
1684 | ||
1685 | /* We can handle some of the 'e' cases here. */ | |
1686 | if (class == 'e' | |
1687 | && (code == TRUTH_NOT_EXPR | |
1688 | || (code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0))) | |
1689 | class = '1'; | |
1690 | else if (class == 'e' | |
1691 | && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR | |
1692 | || code == COMPOUND_EXPR)) | |
1693 | class = '2'; | |
1694 | ||
1695 | switch (class) | |
1696 | { | |
1697 | case '1': | |
1698 | return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2); | |
1699 | ||
1700 | case '2': | |
1701 | return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2) | |
1702 | && twoval_comparison_p (TREE_OPERAND (arg, 1), cval1, cval2)); | |
1703 | ||
1704 | case 'c': | |
1705 | return 1; | |
1706 | ||
1707 | case 'e': | |
1708 | if (code == COND_EXPR) | |
1709 | return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2) | |
1710 | && twoval_comparison_p (TREE_OPERAND (arg, 1), cval1, cval2) | |
1711 | && twoval_comparison_p (TREE_OPERAND (arg, 2), | |
1712 | cval1, cval2)); | |
1713 | return 0; | |
1714 | ||
1715 | case '<': | |
1716 | /* First see if we can handle the first operand, then the second. For | |
1717 | the second operand, we know *CVAL1 can't be zero. It must be that | |
1718 | one side of the comparison is each of the values; test for the | |
1719 | case where this isn't true by failing if the two operands | |
1720 | are the same. */ | |
1721 | ||
1722 | if (operand_equal_p (TREE_OPERAND (arg, 0), | |
1723 | TREE_OPERAND (arg, 1), 0)) | |
1724 | return 0; | |
1725 | ||
1726 | if (*cval1 == 0) | |
1727 | *cval1 = TREE_OPERAND (arg, 0); | |
1728 | else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0)) | |
1729 | ; | |
1730 | else if (*cval2 == 0) | |
1731 | *cval2 = TREE_OPERAND (arg, 0); | |
1732 | else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0)) | |
1733 | ; | |
1734 | else | |
1735 | return 0; | |
1736 | ||
1737 | if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0)) | |
1738 | ; | |
1739 | else if (*cval2 == 0) | |
1740 | *cval2 = TREE_OPERAND (arg, 1); | |
1741 | else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0)) | |
1742 | ; | |
1743 | else | |
1744 | return 0; | |
1745 | ||
1746 | return 1; | |
1747 | } | |
1748 | ||
1749 | return 0; | |
1750 | } | |
1751 | \f | |
1752 | /* ARG is a tree that is known to contain just arithmetic operations and | |
1753 | comparisons. Evaluate the operations in the tree substituting NEW0 for | |
1754 | any occurrance of OLD0 as an operand of a comparison and likewise for | |
1755 | NEW1 and OLD1. */ | |
1756 | ||
1757 | static tree | |
1758 | eval_subst (arg, old0, new0, old1, new1) | |
1759 | tree arg; | |
1760 | tree old0, new0, old1, new1; | |
1761 | { | |
1762 | tree type = TREE_TYPE (arg); | |
1763 | enum tree_code code = TREE_CODE (arg); | |
1764 | char class = TREE_CODE_CLASS (code); | |
1765 | ||
1766 | /* We can handle some of the 'e' cases here. */ | |
1767 | if (class == 'e' && code == TRUTH_NOT_EXPR) | |
1768 | class = '1'; | |
1769 | else if (class == 'e' | |
1770 | && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)) | |
1771 | class = '2'; | |
1772 | ||
1773 | switch (class) | |
1774 | { | |
1775 | case '1': | |
1776 | return fold (build1 (code, type, | |
1777 | eval_subst (TREE_OPERAND (arg, 0), | |
1778 | old0, new0, old1, new1))); | |
1779 | ||
1780 | case '2': | |
1781 | return fold (build (code, type, | |
1782 | eval_subst (TREE_OPERAND (arg, 0), | |
1783 | old0, new0, old1, new1), | |
1784 | eval_subst (TREE_OPERAND (arg, 1), | |
1785 | old0, new0, old1, new1))); | |
1786 | ||
1787 | case 'e': | |
1788 | switch (code) | |
1789 | { | |
1790 | case SAVE_EXPR: | |
1791 | return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1); | |
1792 | ||
1793 | case COMPOUND_EXPR: | |
1794 | return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1); | |
1795 | ||
1796 | case COND_EXPR: | |
1797 | return fold (build (code, type, | |
1798 | eval_subst (TREE_OPERAND (arg, 0), | |
1799 | old0, new0, old1, new1), | |
1800 | eval_subst (TREE_OPERAND (arg, 1), | |
1801 | old0, new0, old1, new1), | |
1802 | eval_subst (TREE_OPERAND (arg, 2), | |
1803 | old0, new0, old1, new1))); | |
1804 | } | |
1805 | ||
1806 | case '<': | |
1807 | { | |
1808 | tree arg0 = TREE_OPERAND (arg, 0); | |
1809 | tree arg1 = TREE_OPERAND (arg, 1); | |
1810 | ||
1811 | /* We need to check both for exact equality and tree equality. The | |
1812 | former will be true if the operand has a side-effect. In that | |
1813 | case, we know the operand occurred exactly once. */ | |
1814 | ||
1815 | if (arg0 == old0 || operand_equal_p (arg0, old0, 0)) | |
1816 | arg0 = new0; | |
1817 | else if (arg0 == old1 || operand_equal_p (arg0, old1, 0)) | |
1818 | arg0 = new1; | |
1819 | ||
1820 | if (arg1 == old0 || operand_equal_p (arg1, old0, 0)) | |
1821 | arg1 = new0; | |
1822 | else if (arg1 == old1 || operand_equal_p (arg1, old1, 0)) | |
1823 | arg1 = new1; | |
1824 | ||
1825 | return fold (build (code, type, arg0, arg1)); | |
1826 | } | |
1827 | } | |
1828 | ||
1829 | return arg; | |
1830 | } | |
1831 | \f | |
6d716ca8 RS |
1832 | /* Return a tree for the case when the result of an expression is RESULT |
1833 | converted to TYPE and OMITTED was previously an operand of the expression | |
1834 | but is now not needed (e.g., we folded OMITTED * 0). | |
1835 | ||
1836 | If OMITTED has side effects, we must evaluate it. Otherwise, just do | |
1837 | the conversion of RESULT to TYPE. */ | |
1838 | ||
1839 | static tree | |
1840 | omit_one_operand (type, result, omitted) | |
1841 | tree type, result, omitted; | |
1842 | { | |
1843 | tree t = convert (type, result); | |
1844 | ||
1845 | if (TREE_SIDE_EFFECTS (omitted)) | |
1846 | return build (COMPOUND_EXPR, type, omitted, t); | |
1847 | ||
1848 | return t; | |
1849 | } | |
1850 | \f | |
1851 | /* Return a simplified tree node for the truth-negation of ARG | |
1852 | (perhaps by altering ARG). It is known that ARG is an operation that | |
1853 | returns a truth value (0 or 1). */ | |
1854 | ||
1855 | tree | |
1856 | invert_truthvalue (arg) | |
1857 | tree arg; | |
1858 | { | |
1859 | tree type = TREE_TYPE (arg); | |
c05a9b68 | 1860 | enum tree_code code = TREE_CODE (arg); |
6d716ca8 | 1861 | |
c05a9b68 RS |
1862 | /* If this is a comparison, we can simply invert it, except for |
1863 | floating-point non-equality comparisons, in which case we just | |
1864 | enclose a TRUTH_NOT_EXPR around what we have. */ | |
6d716ca8 | 1865 | |
c05a9b68 | 1866 | if (TREE_CODE_CLASS (code) == '<') |
6d716ca8 | 1867 | { |
c05a9b68 RS |
1868 | if (TREE_CODE (TREE_TYPE (TREE_OPERAND (arg, 0))) == REAL_TYPE |
1869 | && code != NE_EXPR && code != EQ_EXPR) | |
1870 | return build1 (TRUTH_NOT_EXPR, type, arg); | |
1871 | else | |
1872 | { | |
1873 | TREE_SET_CODE (arg, invert_tree_comparison (code)); | |
1874 | return arg; | |
1875 | } | |
1876 | } | |
6d716ca8 | 1877 | |
c05a9b68 RS |
1878 | switch (code) |
1879 | { | |
6d716ca8 RS |
1880 | case INTEGER_CST: |
1881 | return convert (type, build_int_2 (TREE_INT_CST_LOW (arg) == 0 | |
1882 | && TREE_INT_CST_HIGH (arg) == 0, 0)); | |
1883 | ||
1884 | case TRUTH_AND_EXPR: | |
1885 | return build (TRUTH_OR_EXPR, type, | |
1886 | invert_truthvalue (TREE_OPERAND (arg, 0)), | |
1887 | invert_truthvalue (TREE_OPERAND (arg, 1))); | |
1888 | ||
1889 | case TRUTH_OR_EXPR: | |
1890 | return build (TRUTH_AND_EXPR, type, | |
1891 | invert_truthvalue (TREE_OPERAND (arg, 0)), | |
1892 | invert_truthvalue (TREE_OPERAND (arg, 1))); | |
1893 | ||
1894 | case TRUTH_ANDIF_EXPR: | |
1895 | return build (TRUTH_ORIF_EXPR, type, | |
1896 | invert_truthvalue (TREE_OPERAND (arg, 0)), | |
1897 | invert_truthvalue (TREE_OPERAND (arg, 1))); | |
1898 | ||
1899 | case TRUTH_ORIF_EXPR: | |
1900 | return build (TRUTH_ANDIF_EXPR, type, | |
1901 | invert_truthvalue (TREE_OPERAND (arg, 0)), | |
1902 | invert_truthvalue (TREE_OPERAND (arg, 1))); | |
1903 | ||
1904 | case TRUTH_NOT_EXPR: | |
1905 | return TREE_OPERAND (arg, 0); | |
1906 | ||
1907 | case COND_EXPR: | |
1908 | return build (COND_EXPR, type, TREE_OPERAND (arg, 0), | |
1909 | invert_truthvalue (TREE_OPERAND (arg, 1)), | |
1910 | invert_truthvalue (TREE_OPERAND (arg, 2))); | |
1911 | ||
ef9fe0da RK |
1912 | case COMPOUND_EXPR: |
1913 | return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0), | |
1914 | invert_truthvalue (TREE_OPERAND (arg, 1))); | |
1915 | ||
6d716ca8 RS |
1916 | case NON_LVALUE_EXPR: |
1917 | return invert_truthvalue (TREE_OPERAND (arg, 0)); | |
1918 | ||
1919 | case NOP_EXPR: | |
1920 | case CONVERT_EXPR: | |
1921 | case FLOAT_EXPR: | |
1922 | return build1 (TREE_CODE (arg), type, | |
1923 | invert_truthvalue (TREE_OPERAND (arg, 0))); | |
1924 | ||
1925 | case BIT_AND_EXPR: | |
1926 | if (! integer_onep (TREE_OPERAND (arg, 1))) | |
1927 | abort (); | |
1928 | return build (EQ_EXPR, type, arg, convert (type, integer_zero_node)); | |
1929 | } | |
1930 | ||
1931 | abort (); | |
1932 | } | |
1933 | ||
1934 | /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both | |
1935 | operands are another bit-wise operation with a common input. If so, | |
1936 | distribute the bit operations to save an operation and possibly two if | |
1937 | constants are involved. For example, convert | |
1938 | (A | B) & (A | C) into A | (B & C) | |
1939 | Further simplification will occur if B and C are constants. | |
1940 | ||
1941 | If this optimization cannot be done, 0 will be returned. */ | |
1942 | ||
1943 | static tree | |
1944 | distribute_bit_expr (code, type, arg0, arg1) | |
1945 | enum tree_code code; | |
1946 | tree type; | |
1947 | tree arg0, arg1; | |
1948 | { | |
1949 | tree common; | |
1950 | tree left, right; | |
1951 | ||
1952 | if (TREE_CODE (arg0) != TREE_CODE (arg1) | |
1953 | || TREE_CODE (arg0) == code | |
1954 | || (TREE_CODE (arg0) != BIT_AND_EXPR | |
1955 | && TREE_CODE (arg0) != BIT_IOR_EXPR)) | |
1956 | return 0; | |
1957 | ||
1958 | if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)) | |
1959 | { | |
1960 | common = TREE_OPERAND (arg0, 0); | |
1961 | left = TREE_OPERAND (arg0, 1); | |
1962 | right = TREE_OPERAND (arg1, 1); | |
1963 | } | |
1964 | else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0)) | |
1965 | { | |
1966 | common = TREE_OPERAND (arg0, 0); | |
1967 | left = TREE_OPERAND (arg0, 1); | |
1968 | right = TREE_OPERAND (arg1, 0); | |
1969 | } | |
1970 | else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0)) | |
1971 | { | |
1972 | common = TREE_OPERAND (arg0, 1); | |
1973 | left = TREE_OPERAND (arg0, 0); | |
1974 | right = TREE_OPERAND (arg1, 1); | |
1975 | } | |
1976 | else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0)) | |
1977 | { | |
1978 | common = TREE_OPERAND (arg0, 1); | |
1979 | left = TREE_OPERAND (arg0, 0); | |
1980 | right = TREE_OPERAND (arg1, 0); | |
1981 | } | |
1982 | else | |
1983 | return 0; | |
1984 | ||
1985 | return fold (build (TREE_CODE (arg0), type, common, | |
1986 | fold (build (code, type, left, right)))); | |
1987 | } | |
1988 | \f | |
1989 | /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER | |
1990 | starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */ | |
1991 | ||
1992 | static tree | |
1993 | make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp) | |
1994 | tree inner; | |
1995 | tree type; | |
1996 | int bitsize, bitpos; | |
1997 | int unsignedp; | |
1998 | { | |
1999 | tree result = build (BIT_FIELD_REF, type, inner, | |
2000 | size_int (bitsize), size_int (bitpos)); | |
2001 | ||
2002 | TREE_UNSIGNED (result) = unsignedp; | |
2003 | ||
2004 | return result; | |
2005 | } | |
2006 | ||
2007 | /* Optimize a bit-field compare. | |
2008 | ||
2009 | There are two cases: First is a compare against a constant and the | |
2010 | second is a comparison of two items where the fields are at the same | |
2011 | bit position relative to the start of a chunk (byte, halfword, word) | |
2012 | large enough to contain it. In these cases we can avoid the shift | |
2013 | implicit in bitfield extractions. | |
2014 | ||
2015 | For constants, we emit a compare of the shifted constant with the | |
2016 | BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being | |
2017 | compared. For two fields at the same position, we do the ANDs with the | |
2018 | similar mask and compare the result of the ANDs. | |
2019 | ||
2020 | CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR. | |
2021 | COMPARE_TYPE is the type of the comparison, and LHS and RHS | |
2022 | are the left and right operands of the comparison, respectively. | |
2023 | ||
6dc42e49 | 2024 | If the optimization described above can be done, we return the resulting |
6d716ca8 RS |
2025 | tree. Otherwise we return zero. */ |
2026 | ||
2027 | static tree | |
2028 | optimize_bit_field_compare (code, compare_type, lhs, rhs) | |
2029 | enum tree_code code; | |
2030 | tree compare_type; | |
2031 | tree lhs, rhs; | |
2032 | { | |
2033 | int lbitpos, lbitsize, rbitpos, rbitsize; | |
2034 | int lnbitpos, lnbitsize, rnbitpos, rnbitsize; | |
2035 | tree type = TREE_TYPE (lhs); | |
2036 | tree signed_type, unsigned_type; | |
2037 | int const_p = TREE_CODE (rhs) == INTEGER_CST; | |
2038 | enum machine_mode lmode, rmode, lnmode, rnmode; | |
2039 | int lunsignedp, runsignedp; | |
2040 | int lvolatilep = 0, rvolatilep = 0; | |
2041 | tree linner, rinner; | |
2042 | tree mask; | |
f1e60ec6 | 2043 | tree offset; |
6d716ca8 RS |
2044 | |
2045 | /* Get all the information about the extractions being done. If the bit size | |
2046 | if the same as the size of the underlying object, we aren't doing an | |
2047 | extraction at all and so can do nothing. */ | |
f1e60ec6 | 2048 | linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode, |
6d716ca8 | 2049 | &lunsignedp, &lvolatilep); |
f1e60ec6 RS |
2050 | if (lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0 |
2051 | || offset != 0) | |
6d716ca8 RS |
2052 | return 0; |
2053 | ||
2054 | if (!const_p) | |
2055 | { | |
2056 | /* If this is not a constant, we can only do something if bit positions, | |
2057 | sizes, and signedness are the same. */ | |
f1e60ec6 | 2058 | rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, |
6d716ca8 RS |
2059 | &rmode, &runsignedp, &rvolatilep); |
2060 | ||
2061 | if (lbitpos != rbitpos || lbitsize != rbitsize | |
f1e60ec6 | 2062 | || lunsignedp != runsignedp || offset != 0) |
6d716ca8 RS |
2063 | return 0; |
2064 | } | |
2065 | ||
2066 | /* See if we can find a mode to refer to this field. We should be able to, | |
2067 | but fail if we can't. */ | |
2068 | lnmode = get_best_mode (lbitsize, lbitpos, | |
2069 | TYPE_ALIGN (TREE_TYPE (linner)), word_mode, | |
2070 | lvolatilep); | |
2071 | if (lnmode == VOIDmode) | |
2072 | return 0; | |
2073 | ||
2074 | /* Set signed and unsigned types of the precision of this mode for the | |
2075 | shifts below. */ | |
2076 | signed_type = type_for_mode (lnmode, 0); | |
2077 | unsigned_type = type_for_mode (lnmode, 1); | |
2078 | ||
2079 | if (! const_p) | |
2080 | { | |
2081 | rnmode = get_best_mode (rbitsize, rbitpos, | |
2082 | TYPE_ALIGN (TREE_TYPE (rinner)), word_mode, | |
2083 | rvolatilep); | |
2084 | if (rnmode == VOIDmode) | |
2085 | return 0; | |
2086 | } | |
2087 | ||
2088 | /* Compute the bit position and size for the new reference and our offset | |
2089 | within it. If the new reference is the same size as the original, we | |
2090 | won't optimize anything, so return zero. */ | |
2091 | lnbitsize = GET_MODE_BITSIZE (lnmode); | |
2092 | lnbitpos = lbitpos & ~ (lnbitsize - 1); | |
2093 | lbitpos -= lnbitpos; | |
2094 | if (lnbitsize == lbitsize) | |
2095 | return 0; | |
2096 | ||
2097 | if (! const_p) | |
2098 | { | |
2099 | rnbitsize = GET_MODE_BITSIZE (rnmode); | |
2100 | rnbitpos = rbitpos & ~ (rnbitsize - 1); | |
2101 | rbitpos -= rnbitpos; | |
2102 | if (rnbitsize == rbitsize) | |
2103 | return 0; | |
2104 | } | |
2105 | ||
2106 | #if BYTES_BIG_ENDIAN | |
2107 | lbitpos = lnbitsize - lbitsize - lbitpos; | |
2108 | rbitpos = rnbitsize - rbitsize - rbitpos; | |
2109 | #endif | |
2110 | ||
2111 | /* Make the mask to be used against the extracted field. */ | |
2112 | mask = convert (unsigned_type, build_int_2 (~0, ~0)); | |
2113 | mask = const_binop (LSHIFT_EXPR, mask, size_int (lnbitsize - lbitsize)); | |
2114 | mask = const_binop (RSHIFT_EXPR, mask, | |
2115 | size_int (lnbitsize - lbitsize - lbitpos)); | |
2116 | ||
2117 | if (! const_p) | |
2118 | /* If not comparing with constant, just rework the comparison | |
2119 | and return. */ | |
2120 | return build (code, compare_type, | |
2121 | build (BIT_AND_EXPR, type, | |
2122 | make_bit_field_ref (linner, type, | |
2123 | lnbitsize, lnbitpos, lunsignedp), | |
2124 | mask), | |
2125 | build (BIT_AND_EXPR, type, | |
2126 | make_bit_field_ref (rinner, type, | |
2127 | rnbitsize, rnbitpos, runsignedp), | |
2128 | mask)); | |
2129 | ||
2130 | /* Otherwise, we are handling the constant case. See if the constant is too | |
2131 | big for the field. Warn and return a tree of for 0 (false) if so. We do | |
2132 | this not only for its own sake, but to avoid having to test for this | |
2133 | error case below. If we didn't, we might generate wrong code. | |
2134 | ||
2135 | For unsigned fields, the constant shifted right by the field length should | |
2136 | be all zero. For signed fields, the high-order bits should agree with | |
2137 | the sign bit. */ | |
2138 | ||
2139 | if (lunsignedp) | |
2140 | { | |
2141 | if (! integer_zerop (const_binop (RSHIFT_EXPR, | |
2142 | convert (unsigned_type, rhs), | |
2143 | size_int (lbitsize)))) | |
2144 | { | |
2145 | warning ("comparison is always %s due to width of bitfield", | |
2146 | code == NE_EXPR ? "one" : "zero"); | |
2147 | return convert (compare_type, | |
2148 | (code == NE_EXPR | |
2149 | ? integer_one_node : integer_zero_node)); | |
2150 | } | |
2151 | } | |
2152 | else | |
2153 | { | |
2154 | tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs), | |
2155 | size_int (lbitsize - 1)); | |
2156 | if (! integer_zerop (tem) && ! integer_all_onesp (tem)) | |
2157 | { | |
2158 | warning ("comparison is always %s due to width of bitfield", | |
2159 | code == NE_EXPR ? "one" : "zero"); | |
2160 | return convert (compare_type, | |
2161 | (code == NE_EXPR | |
2162 | ? integer_one_node : integer_zero_node)); | |
2163 | } | |
2164 | } | |
2165 | ||
2166 | /* Single-bit compares should always be against zero. */ | |
2167 | if (lbitsize == 1 && ! integer_zerop (rhs)) | |
2168 | { | |
2169 | code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR; | |
2170 | rhs = convert (type, integer_zero_node); | |
2171 | } | |
2172 | ||
2173 | /* Make a new bitfield reference, shift the constant over the | |
2174 | appropriate number of bits and mask it with the computed mask | |
2175 | (in case this was a signed field). If we changed it, make a new one. */ | |
2176 | lhs = make_bit_field_ref (linner, TREE_TYPE (lhs), lnbitsize, lnbitpos, | |
2177 | lunsignedp); | |
2178 | ||
2179 | rhs = fold (build1 (NOP_EXPR, type, | |
2180 | const_binop (BIT_AND_EXPR, | |
2181 | const_binop (LSHIFT_EXPR, | |
2182 | convert (unsigned_type, rhs), | |
2183 | size_int (lbitpos)), mask))); | |
2184 | ||
2185 | return build (code, compare_type, | |
2186 | build (BIT_AND_EXPR, type, lhs, mask), | |
2187 | rhs); | |
2188 | } | |
2189 | \f | |
2190 | /* Subroutine for the following routine: decode a field reference. | |
2191 | ||
2192 | If EXP is a comparison reference, we return the innermost reference. | |
2193 | ||
2194 | *PBITSIZE is set to the number of bits in the reference, *PBITPOS is | |
2195 | set to the starting bit number. | |
2196 | ||
2197 | If the innermost field can be completely contained in a mode-sized | |
2198 | unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode. | |
2199 | ||
2200 | *PVOLATILEP is set to 1 if the any expression encountered is volatile; | |
2201 | otherwise it is not changed. | |
2202 | ||
2203 | *PUNSIGNEDP is set to the signedness of the field. | |
2204 | ||
2205 | *PMASK is set to the mask used. This is either contained in a | |
2206 | BIT_AND_EXPR or derived from the width of the field. | |
2207 | ||
2208 | Return 0 if this is not a component reference or is one that we can't | |
2209 | do anything with. */ | |
2210 | ||
2211 | static tree | |
2212 | decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp, | |
2213 | pvolatilep, pmask) | |
2214 | tree exp; | |
2215 | int *pbitsize, *pbitpos; | |
2216 | enum machine_mode *pmode; | |
2217 | int *punsignedp, *pvolatilep; | |
2218 | tree *pmask; | |
2219 | { | |
2220 | tree mask = 0; | |
2221 | tree inner; | |
f1e60ec6 | 2222 | tree offset; |
6d716ca8 RS |
2223 | |
2224 | STRIP_NOPS (exp); | |
2225 | ||
2226 | if (TREE_CODE (exp) == BIT_AND_EXPR) | |
2227 | { | |
2228 | mask = TREE_OPERAND (exp, 1); | |
2229 | exp = TREE_OPERAND (exp, 0); | |
2230 | STRIP_NOPS (exp); STRIP_NOPS (mask); | |
2231 | if (TREE_CODE (mask) != INTEGER_CST) | |
2232 | return 0; | |
2233 | } | |
2234 | ||
2235 | if (TREE_CODE (exp) != COMPONENT_REF && TREE_CODE (exp) != ARRAY_REF | |
2236 | && TREE_CODE (exp) != BIT_FIELD_REF) | |
2237 | return 0; | |
2238 | ||
f1e60ec6 | 2239 | inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode, |
6d716ca8 | 2240 | punsignedp, pvolatilep); |
f1e60ec6 | 2241 | if (*pbitsize < 0 || offset != 0) |
c05a9b68 | 2242 | return 0; |
6d716ca8 RS |
2243 | |
2244 | if (mask == 0) | |
2245 | { | |
2246 | tree unsigned_type = type_for_size (*pbitsize, 1); | |
2247 | int precision = TYPE_PRECISION (unsigned_type); | |
2248 | ||
2249 | mask = convert (unsigned_type, build_int_2 (~0, ~0)); | |
2250 | mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize)); | |
2251 | mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize)); | |
2252 | } | |
2253 | ||
2254 | *pmask = mask; | |
2255 | return inner; | |
2256 | } | |
2257 | ||
6dc42e49 | 2258 | /* Return non-zero if MASK represents a mask of SIZE ones in the low-order |
6d716ca8 RS |
2259 | bit positions. */ |
2260 | ||
2261 | static int | |
2262 | all_ones_mask_p (mask, size) | |
2263 | tree mask; | |
2264 | int size; | |
2265 | { | |
2266 | tree type = TREE_TYPE (mask); | |
2267 | int precision = TYPE_PRECISION (type); | |
2268 | ||
2269 | return | |
2270 | operand_equal_p (mask, | |
2271 | const_binop (RSHIFT_EXPR, | |
2272 | const_binop (LSHIFT_EXPR, | |
2273 | convert (signed_type (type), | |
2274 | build_int_2 (~0, ~0)), | |
2275 | size_int (precision - size)), | |
2276 | size_int (precision - size)), 0); | |
2277 | } | |
2278 | \f | |
2279 | /* Try to merge two comparisons to the same innermost item. | |
2280 | ||
2281 | For example, if we have p->a == 2 && p->b == 4 and we can make an | |
2282 | object large enough to span both A and B, we can do this with a comparison | |
2283 | against the object ANDed with the a mask. | |
2284 | ||
2285 | If we have p->a == q->a && p->b == q->b, we may be able to use bit masking | |
2286 | operations to do this with one comparison. | |
2287 | ||
2288 | We check for both normal comparisons and the BIT_AND_EXPRs made this by | |
2289 | function and the one above. | |
2290 | ||
2291 | CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR, | |
2292 | TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR. | |
2293 | ||
2294 | TRUTH_TYPE is the type of the logical operand and LHS and RHS are its | |
2295 | two operands. | |
2296 | ||
2297 | We return the simplified tree or 0 if no optimization is possible. */ | |
2298 | ||
2299 | static tree | |
2300 | merge_component_references (code, truth_type, lhs, rhs) | |
2301 | enum tree_code code; | |
2302 | tree truth_type, lhs, rhs; | |
2303 | { | |
2304 | /* If this is the "or" of two comparisons, we can do something if we | |
2305 | the comparisons are NE_EXPR. If this is the "and", we can do something | |
2306 | if the comparisons are EQ_EXPR. I.e., | |
2307 | (a->b == 2 && a->c == 4) can become (a->new == NEW). | |
2308 | ||
2309 | WANTED_CODE is this operation code. For single bit fields, we can | |
2310 | convert EQ_EXPR to NE_EXPR so we need not reject the "wrong" | |
2311 | comparison for one-bit fields. */ | |
2312 | ||
2313 | enum tree_code wanted_code | |
2314 | = (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR) ? EQ_EXPR : NE_EXPR; | |
2315 | enum tree_code lcode, rcode; | |
2316 | tree ll_inner, lr_inner, rl_inner, rr_inner; | |
2317 | int ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos; | |
2318 | int rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos; | |
2319 | int xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos; | |
2320 | int lnbitsize, lnbitpos, rnbitsize, rnbitpos; | |
2321 | int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp; | |
2322 | enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode; | |
2323 | enum machine_mode lnmode, rnmode; | |
2324 | tree ll_mask, lr_mask, rl_mask, rr_mask; | |
2325 | tree l_const = 0, r_const = 0; | |
2326 | tree type, result; | |
2327 | int first_bit, end_bit; | |
2328 | int volatilep = 0; | |
2329 | ||
2330 | /* Start by getting the comparison codes and seeing if we may be able | |
2331 | to do something. Then get all the parameters for each side. Fail | |
2332 | if anything is volatile. */ | |
2333 | ||
2334 | lcode = TREE_CODE (lhs); | |
2335 | rcode = TREE_CODE (rhs); | |
2336 | if ((lcode != EQ_EXPR && lcode != NE_EXPR) | |
2337 | || (rcode != EQ_EXPR && rcode != NE_EXPR) | |
2338 | || TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs)) | |
2339 | return 0; | |
2340 | ||
2341 | ll_inner = decode_field_reference (TREE_OPERAND (lhs, 0), | |
2342 | &ll_bitsize, &ll_bitpos, &ll_mode, | |
2343 | &ll_unsignedp, &volatilep, &ll_mask); | |
2344 | lr_inner = decode_field_reference (TREE_OPERAND (lhs, 1), | |
2345 | &lr_bitsize, &lr_bitpos, &lr_mode, | |
2346 | &lr_unsignedp, &volatilep, &lr_mask); | |
2347 | rl_inner = decode_field_reference (TREE_OPERAND (rhs, 0), | |
2348 | &rl_bitsize, &rl_bitpos, &rl_mode, | |
2349 | &rl_unsignedp, &volatilep, &rl_mask); | |
2350 | rr_inner = decode_field_reference (TREE_OPERAND (rhs, 1), | |
2351 | &rr_bitsize, &rr_bitpos, &rr_mode, | |
2352 | &rr_unsignedp, &volatilep, &rr_mask); | |
2353 | ||
2354 | /* It must be true that the inner operation on the lhs of each | |
2355 | comparison must be the same if we are to be able to do anything. | |
2356 | Then see if we have constants. If not, the same must be true for | |
2357 | the rhs's. */ | |
2358 | if (volatilep || ll_inner == 0 || rl_inner == 0 | |
2359 | || ! operand_equal_p (ll_inner, rl_inner, 0)) | |
2360 | return 0; | |
2361 | ||
2362 | if (TREE_CODE (TREE_OPERAND (lhs, 1)) == INTEGER_CST | |
2363 | && TREE_CODE (TREE_OPERAND (rhs, 1)) == INTEGER_CST) | |
2364 | l_const = TREE_OPERAND (lhs, 1), r_const = TREE_OPERAND (rhs, 1); | |
2365 | else if (lr_inner == 0 || rr_inner == 0 | |
2366 | || ! operand_equal_p (lr_inner, rr_inner, 0)) | |
2367 | return 0; | |
2368 | ||
2369 | /* If either comparison code is not correct for our logical operation, | |
2370 | fail. However, we can convert a one-bit comparison against zero into | |
2371 | the opposite comparison against that bit being set in the field. */ | |
2372 | if (lcode != wanted_code) | |
2373 | { | |
2374 | if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask)) | |
2375 | l_const = ll_mask; | |
2376 | else | |
2377 | return 0; | |
2378 | } | |
2379 | ||
2380 | if (rcode != wanted_code) | |
2381 | { | |
2382 | if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask)) | |
2383 | r_const = rl_mask; | |
2384 | else | |
2385 | return 0; | |
2386 | } | |
2387 | ||
2388 | /* See if we can find a mode that contains both fields being compared on | |
2389 | the left. If we can't, fail. Otherwise, update all constants and masks | |
2390 | to be relative to a field of that size. */ | |
2391 | first_bit = MIN (ll_bitpos, rl_bitpos); | |
2392 | end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize); | |
2393 | lnmode = get_best_mode (end_bit - first_bit, first_bit, | |
2394 | TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode, | |
2395 | volatilep); | |
2396 | if (lnmode == VOIDmode) | |
2397 | return 0; | |
2398 | ||
2399 | lnbitsize = GET_MODE_BITSIZE (lnmode); | |
2400 | lnbitpos = first_bit & ~ (lnbitsize - 1); | |
2401 | type = type_for_size (lnbitsize, 1); | |
2402 | xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos; | |
2403 | ||
2404 | #if BYTES_BIG_ENDIAN | |
2405 | xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize; | |
2406 | xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize; | |
2407 | #endif | |
2408 | ||
2409 | ll_mask = const_binop (LSHIFT_EXPR, convert (type, ll_mask), | |
2410 | size_int (xll_bitpos)); | |
2411 | rl_mask = const_binop (LSHIFT_EXPR, convert (type, rl_mask), | |
2412 | size_int (xrl_bitpos)); | |
2413 | ||
2414 | /* Make sure the constants are interpreted as unsigned, so we | |
2415 | don't have sign bits outside the range of their type. */ | |
2416 | ||
2417 | if (l_const) | |
2418 | { | |
2419 | l_const = convert (unsigned_type (TREE_TYPE (l_const)), l_const); | |
2420 | l_const = const_binop (LSHIFT_EXPR, convert (type, l_const), | |
2421 | size_int (xll_bitpos)); | |
2422 | } | |
2423 | if (r_const) | |
2424 | { | |
2425 | r_const = convert (unsigned_type (TREE_TYPE (r_const)), r_const); | |
2426 | r_const = const_binop (LSHIFT_EXPR, convert (type, r_const), | |
2427 | size_int (xrl_bitpos)); | |
2428 | } | |
2429 | ||
2430 | /* If the right sides are not constant, do the same for it. Also, | |
2431 | disallow this optimization if a size or signedness mismatch occurs | |
2432 | between the left and right sides. */ | |
2433 | if (l_const == 0) | |
2434 | { | |
2435 | if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize | |
2436 | || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp) | |
2437 | return 0; | |
2438 | ||
2439 | first_bit = MIN (lr_bitpos, rr_bitpos); | |
2440 | end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize); | |
2441 | rnmode = get_best_mode (end_bit - first_bit, first_bit, | |
2442 | TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode, | |
2443 | volatilep); | |
2444 | if (rnmode == VOIDmode) | |
2445 | return 0; | |
2446 | ||
2447 | rnbitsize = GET_MODE_BITSIZE (rnmode); | |
2448 | rnbitpos = first_bit & ~ (rnbitsize - 1); | |
2449 | xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos; | |
2450 | ||
2451 | #if BYTES_BIG_ENDIAN | |
2452 | xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize; | |
2453 | xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize; | |
2454 | #endif | |
2455 | ||
2456 | lr_mask = const_binop (LSHIFT_EXPR, convert (type, lr_mask), | |
2457 | size_int (xlr_bitpos)); | |
2458 | rr_mask = const_binop (LSHIFT_EXPR, convert (type, rr_mask), | |
2459 | size_int (xrr_bitpos)); | |
2460 | ||
2461 | /* Make a mask that corresponds to both fields being compared. | |
2462 | Do this for both items being compared. If the masks agree, | |
2463 | we can do this by masking both and comparing the masked | |
2464 | results. */ | |
2465 | ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask); | |
2466 | lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask); | |
2467 | if (operand_equal_p (ll_mask, lr_mask, 0) && lnbitsize == rnbitsize) | |
2468 | { | |
2469 | lhs = make_bit_field_ref (ll_inner, type, lnbitsize, lnbitpos, | |
2470 | ll_unsignedp || rl_unsignedp); | |
2471 | rhs = make_bit_field_ref (lr_inner, type, rnbitsize, rnbitpos, | |
2472 | lr_unsignedp || rr_unsignedp); | |
2473 | if (! all_ones_mask_p (ll_mask, lnbitsize)) | |
2474 | { | |
2475 | lhs = build (BIT_AND_EXPR, type, lhs, ll_mask); | |
2476 | rhs = build (BIT_AND_EXPR, type, rhs, ll_mask); | |
2477 | } | |
2478 | return build (wanted_code, truth_type, lhs, rhs); | |
2479 | } | |
2480 | ||
2481 | /* There is still another way we can do something: If both pairs of | |
2482 | fields being compared are adjacent, we may be able to make a wider | |
2483 | field containing them both. */ | |
2484 | if ((ll_bitsize + ll_bitpos == rl_bitpos | |
2485 | && lr_bitsize + lr_bitpos == rr_bitpos) | |
2486 | || (ll_bitpos == rl_bitpos + rl_bitsize | |
2487 | && lr_bitpos == rr_bitpos + rr_bitsize)) | |
2488 | return build (wanted_code, truth_type, | |
2489 | make_bit_field_ref (ll_inner, type, | |
2490 | ll_bitsize + rl_bitsize, | |
2491 | MIN (ll_bitpos, rl_bitpos), | |
2492 | ll_unsignedp), | |
2493 | make_bit_field_ref (lr_inner, type, | |
2494 | lr_bitsize + rr_bitsize, | |
2495 | MIN (lr_bitpos, rr_bitpos), | |
2496 | lr_unsignedp)); | |
2497 | ||
2498 | return 0; | |
2499 | } | |
2500 | ||
2501 | /* Handle the case of comparisons with constants. If there is something in | |
2502 | common between the masks, those bits of the constants must be the same. | |
2503 | If not, the condition is always false. Test for this to avoid generating | |
2504 | incorrect code below. */ | |
2505 | result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask); | |
2506 | if (! integer_zerop (result) | |
2507 | && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const), | |
2508 | const_binop (BIT_AND_EXPR, result, r_const)) != 1) | |
2509 | { | |
2510 | if (wanted_code == NE_EXPR) | |
2511 | { | |
2512 | warning ("`or' of unmatched not-equal tests is always 1"); | |
2513 | return convert (truth_type, integer_one_node); | |
2514 | } | |
2515 | else | |
2516 | { | |
2517 | warning ("`and' of mutually exclusive equal-tests is always zero"); | |
2518 | return convert (truth_type, integer_zero_node); | |
2519 | } | |
2520 | } | |
2521 | ||
2522 | /* Construct the expression we will return. First get the component | |
2523 | reference we will make. Unless the mask is all ones the width of | |
2524 | that field, perform the mask operation. Then compare with the | |
2525 | merged constant. */ | |
2526 | result = make_bit_field_ref (ll_inner, type, lnbitsize, lnbitpos, | |
2527 | ll_unsignedp || rl_unsignedp); | |
2528 | ||
2529 | ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask); | |
2530 | if (! all_ones_mask_p (ll_mask, lnbitsize)) | |
2531 | result = build (BIT_AND_EXPR, type, result, ll_mask); | |
2532 | ||
2533 | return build (wanted_code, truth_type, result, | |
2534 | const_binop (BIT_IOR_EXPR, l_const, r_const)); | |
2535 | } | |
2536 | \f | |
2537 | /* Perform constant folding and related simplification of EXPR. | |
2538 | The related simplifications include x*1 => x, x*0 => 0, etc., | |
2539 | and application of the associative law. | |
2540 | NOP_EXPR conversions may be removed freely (as long as we | |
2541 | are careful not to change the C type of the overall expression) | |
2542 | We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR, | |
2543 | but we can constant-fold them if they have constant operands. */ | |
2544 | ||
2545 | tree | |
2546 | fold (expr) | |
2547 | tree expr; | |
2548 | { | |
2549 | register tree t = expr; | |
2550 | tree t1 = NULL_TREE; | |
c05a9b68 | 2551 | tree tem; |
6d716ca8 RS |
2552 | tree type = TREE_TYPE (expr); |
2553 | register tree arg0, arg1; | |
2554 | register enum tree_code code = TREE_CODE (t); | |
2555 | register int kind; | |
c05a9b68 | 2556 | int invert; |
6d716ca8 RS |
2557 | |
2558 | /* WINS will be nonzero when the switch is done | |
2559 | if all operands are constant. */ | |
2560 | ||
2561 | int wins = 1; | |
2562 | ||
2563 | /* Return right away if already constant. */ | |
2564 | if (TREE_CONSTANT (t)) | |
2565 | { | |
2566 | if (code == CONST_DECL) | |
2567 | return DECL_INITIAL (t); | |
2568 | return t; | |
2569 | } | |
2570 | ||
2571 | kind = TREE_CODE_CLASS (code); | |
2572 | if (kind == 'e' || kind == '<' || kind == '1' || kind == '2' || kind == 'r') | |
2573 | { | |
2574 | register int len = tree_code_length[(int) code]; | |
2575 | register int i; | |
2576 | for (i = 0; i < len; i++) | |
2577 | { | |
2578 | tree op = TREE_OPERAND (t, i); | |
2579 | ||
2580 | if (op == 0) | |
2581 | continue; /* Valid for CALL_EXPR, at least. */ | |
2582 | ||
2583 | /* Strip any conversions that don't change the mode. */ | |
2584 | STRIP_NOPS (op); | |
2585 | ||
2586 | if (TREE_CODE (op) != INTEGER_CST | |
2587 | #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) | |
2588 | && TREE_CODE (op) != REAL_CST | |
2589 | #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */ | |
2590 | ) | |
2591 | /* Note that TREE_CONSTANT isn't enough: | |
2592 | static var addresses are constant but we can't | |
2593 | do arithmetic on them. */ | |
2594 | wins = 0; | |
2595 | ||
2596 | if (i == 0) | |
2597 | arg0 = op; | |
2598 | else if (i == 1) | |
2599 | arg1 = op; | |
2600 | } | |
2601 | } | |
2602 | ||
2603 | /* If this is a commutative operation, and ARG0 is a constant, move it | |
2604 | to ARG1 to reduce the number of tests below. */ | |
2605 | if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR | |
2606 | || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR | |
2607 | || code == BIT_AND_EXPR) | |
2608 | && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)) | |
2609 | { | |
c05a9b68 | 2610 | tem = arg0; arg0 = arg1; arg1 = tem; |
6d716ca8 | 2611 | |
c05a9b68 RS |
2612 | tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1); |
2613 | TREE_OPERAND (t, 1) = tem; | |
6d716ca8 RS |
2614 | } |
2615 | ||
2616 | /* Now WINS is set as described above, | |
2617 | ARG0 is the first operand of EXPR, | |
2618 | and ARG1 is the second operand (if it has more than one operand). | |
2619 | ||
2620 | First check for cases where an arithmetic operation is applied to a | |
2621 | compound, conditional, or comparison operation. Push the arithmetic | |
2622 | operation inside the compound or conditional to see if any folding | |
2623 | can then be done. Convert comparison to conditional for this purpose. | |
2624 | The also optimizes non-constant cases that used to be done in | |
2625 | expand_expr. */ | |
2626 | if (TREE_CODE_CLASS (code) == '1') | |
2627 | { | |
2628 | if (TREE_CODE (arg0) == COMPOUND_EXPR) | |
2629 | return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0), | |
2630 | fold (build1 (code, type, TREE_OPERAND (arg0, 1)))); | |
2631 | else if (TREE_CODE (arg0) == COND_EXPR) | |
2632 | return fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0), | |
2633 | fold (build1 (code, type, TREE_OPERAND (arg0, 1))), | |
2634 | fold (build1 (code, type, TREE_OPERAND (arg0, 2))))); | |
2635 | else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<') | |
2636 | return fold (build (COND_EXPR, type, arg0, | |
2637 | fold (build1 (code, type, integer_one_node)), | |
2638 | fold (build1 (code, type, integer_zero_node)))); | |
2639 | } | |
2640 | else if (TREE_CODE_CLASS (code) == '2') | |
2641 | { | |
2642 | if (TREE_CODE (arg1) == COMPOUND_EXPR) | |
2643 | return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0), | |
2644 | fold (build (code, type, arg0, TREE_OPERAND (arg1, 1)))); | |
2645 | else if (TREE_CODE (arg1) == COND_EXPR | |
2646 | || TREE_CODE_CLASS (TREE_CODE (arg1)) == '<') | |
2647 | { | |
2648 | tree test, true_value, false_value; | |
2649 | ||
2650 | if (TREE_CODE (arg1) == COND_EXPR) | |
2651 | { | |
2652 | test = TREE_OPERAND (arg1, 0); | |
2653 | true_value = TREE_OPERAND (arg1, 1); | |
2654 | false_value = TREE_OPERAND (arg1, 2); | |
2655 | } | |
2656 | else | |
2657 | { | |
2658 | test = arg1; | |
2659 | true_value = integer_one_node; | |
2660 | false_value = integer_zero_node; | |
2661 | } | |
2662 | ||
2663 | if (TREE_CODE (arg0) != VAR_DECL && TREE_CODE (arg0) != PARM_DECL) | |
2664 | arg0 = save_expr (arg0); | |
2665 | test = fold (build (COND_EXPR, type, test, | |
2666 | fold (build (code, type, arg0, true_value)), | |
2667 | fold (build (code, type, arg0, false_value)))); | |
2668 | if (TREE_CODE (arg0) == SAVE_EXPR) | |
2669 | return build (COMPOUND_EXPR, type, | |
2670 | convert (void_type_node, arg0), test); | |
2671 | else | |
2672 | return convert (type, test); | |
2673 | } | |
2674 | ||
2675 | else if (TREE_CODE (arg0) == COMPOUND_EXPR) | |
2676 | return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0), | |
2677 | fold (build (code, type, TREE_OPERAND (arg0, 1), arg1))); | |
2678 | else if (TREE_CODE (arg0) == COND_EXPR | |
2679 | || TREE_CODE_CLASS (TREE_CODE (arg0)) == '<') | |
2680 | { | |
2681 | tree test, true_value, false_value; | |
2682 | ||
2683 | if (TREE_CODE (arg0) == COND_EXPR) | |
2684 | { | |
2685 | test = TREE_OPERAND (arg0, 0); | |
2686 | true_value = TREE_OPERAND (arg0, 1); | |
2687 | false_value = TREE_OPERAND (arg0, 2); | |
2688 | } | |
2689 | else | |
2690 | { | |
2691 | test = arg0; | |
2692 | true_value = integer_one_node; | |
2693 | false_value = integer_zero_node; | |
2694 | } | |
2695 | ||
2696 | if (TREE_CODE (arg1) != VAR_DECL && TREE_CODE (arg1) != PARM_DECL) | |
2697 | arg1 = save_expr (arg1); | |
2698 | test = fold (build (COND_EXPR, type, test, | |
2699 | fold (build (code, type, true_value, arg1)), | |
2700 | fold (build (code, type, false_value, arg1)))); | |
2701 | if (TREE_CODE (arg1) == SAVE_EXPR) | |
2702 | return build (COMPOUND_EXPR, type, | |
2703 | convert (void_type_node, arg1), test); | |
2704 | else | |
2705 | return convert (type, test); | |
2706 | } | |
2707 | } | |
c05a9b68 RS |
2708 | else if (TREE_CODE_CLASS (code) == '<' |
2709 | && TREE_CODE (arg0) == COMPOUND_EXPR) | |
2710 | return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0), | |
2711 | fold (build (code, type, TREE_OPERAND (arg0, 1), arg1))); | |
2712 | else if (TREE_CODE_CLASS (code) == '<' | |
2713 | && TREE_CODE (arg1) == COMPOUND_EXPR) | |
2714 | return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0), | |
2715 | fold (build (code, type, arg0, TREE_OPERAND (arg1, 1)))); | |
6d716ca8 RS |
2716 | |
2717 | switch (code) | |
2718 | { | |
2719 | case INTEGER_CST: | |
2720 | case REAL_CST: | |
2721 | case STRING_CST: | |
2722 | case COMPLEX_CST: | |
2723 | case CONSTRUCTOR: | |
2724 | return t; | |
2725 | ||
2726 | case CONST_DECL: | |
2727 | return fold (DECL_INITIAL (t)); | |
2728 | ||
2729 | case NOP_EXPR: | |
2730 | case FLOAT_EXPR: | |
2731 | case CONVERT_EXPR: | |
2732 | case FIX_TRUNC_EXPR: | |
2733 | /* Other kinds of FIX are not handled properly by fold_convert. */ | |
2734 | /* Two conversions in a row are not needed unless: | |
2735 | - the intermediate type is narrower than both initial and final, or | |
68d88491 RS |
2736 | - the intermediate type and innermost type differ in signedness, |
2737 | and the outermost type is wider than the intermediate, or | |
6d716ca8 RS |
2738 | - the initial type is a pointer type and the precisions of the |
2739 | intermediate and final types differ, or | |
2740 | - the final type is a pointer type and the precisions of the | |
2741 | initial and intermediate types differ. */ | |
2742 | if ((TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR | |
2743 | || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR) | |
2744 | && (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t, 0))) | |
2745 | > TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))) | |
2746 | || | |
2747 | TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t, 0))) | |
2748 | > TYPE_PRECISION (TREE_TYPE (t))) | |
68d88491 RS |
2749 | && ! ((TREE_CODE (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))) |
2750 | == INTEGER_TYPE) | |
2751 | && (TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) | |
2752 | == INTEGER_TYPE) | |
2753 | && (TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (t, 0))) | |
2754 | != TREE_UNSIGNED (TREE_OPERAND (TREE_OPERAND (t, 0), 0))) | |
2755 | && (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t, 0))) | |
2756 | < TYPE_PRECISION (TREE_TYPE (t)))) | |
6d716ca8 RS |
2757 | && ((TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (t, 0))) |
2758 | && (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t, 0))) | |
2759 | > TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))))) | |
2760 | == | |
2761 | (TREE_UNSIGNED (TREE_TYPE (t)) | |
2762 | && (TYPE_PRECISION (TREE_TYPE (t)) | |
2763 | > TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t, 0)))))) | |
2764 | && ! ((TREE_CODE (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))) | |
2765 | == POINTER_TYPE) | |
2766 | && (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t, 0))) | |
2767 | != TYPE_PRECISION (TREE_TYPE (t)))) | |
2768 | && ! (TREE_CODE (TREE_TYPE (t)) == POINTER_TYPE | |
2769 | && (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))) | |
2770 | != TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t, 0)))))) | |
2771 | return convert (TREE_TYPE (t), TREE_OPERAND (TREE_OPERAND (t, 0), 0)); | |
2772 | ||
2773 | if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR | |
d8f6dbb9 RS |
2774 | && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) |
2775 | /* Detect assigning a bitfield. */ | |
2776 | && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF | |
2777 | && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1)))) | |
6d716ca8 | 2778 | { |
d8f6dbb9 RS |
2779 | /* Don't leave an assignment inside a conversion |
2780 | unless assiging a bitfield. */ | |
6d716ca8 RS |
2781 | tree prev = TREE_OPERAND (t, 0); |
2782 | TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1); | |
2783 | /* First do the assignment, then return converted constant. */ | |
2784 | t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t)); | |
2785 | TREE_USED (t) = 1; | |
2786 | return t; | |
2787 | } | |
2788 | if (!wins) | |
2789 | { | |
2790 | TREE_CONSTANT (t) = TREE_CONSTANT (arg0); | |
2791 | return t; | |
2792 | } | |
2793 | return fold_convert (t, arg0); | |
2794 | ||
2795 | #if 0 /* This loses on &"foo"[0]. */ | |
2796 | case ARRAY_REF: | |
2797 | { | |
2798 | int i; | |
2799 | ||
2800 | /* Fold an expression like: "foo"[2] */ | |
2801 | if (TREE_CODE (arg0) == STRING_CST | |
2802 | && TREE_CODE (arg1) == INTEGER_CST | |
2803 | && !TREE_INT_CST_HIGH (arg1) | |
2804 | && (i = TREE_INT_CST_LOW (arg1)) < TREE_STRING_LENGTH (arg0)) | |
2805 | { | |
2806 | t = build_int_2 (TREE_STRING_POINTER (arg0)[i], 0); | |
2807 | TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (arg0)); | |
2808 | force_fit_type (t); | |
2809 | } | |
2810 | } | |
2811 | return t; | |
2812 | #endif /* 0 */ | |
2813 | ||
2814 | case RANGE_EXPR: | |
2815 | TREE_CONSTANT (t) = wins; | |
2816 | return t; | |
2817 | ||
2818 | case NEGATE_EXPR: | |
2819 | if (wins) | |
2820 | { | |
2821 | if (TREE_CODE (arg0) == INTEGER_CST) | |
2822 | { | |
2823 | if (TREE_INT_CST_LOW (arg0) == 0) | |
2824 | t = build_int_2 (0, - TREE_INT_CST_HIGH (arg0)); | |
2825 | else | |
2826 | t = build_int_2 (- TREE_INT_CST_LOW (arg0), | |
2827 | ~ TREE_INT_CST_HIGH (arg0)); | |
2828 | TREE_TYPE (t) = type; | |
2829 | force_fit_type (t); | |
2830 | } | |
2831 | else if (TREE_CODE (arg0) == REAL_CST) | |
2832 | t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0))); | |
2833 | TREE_TYPE (t) = type; | |
2834 | } | |
2835 | else if (TREE_CODE (arg0) == NEGATE_EXPR) | |
2836 | return TREE_OPERAND (arg0, 0); | |
2837 | ||
2838 | /* Convert - (a - b) to (b - a) for non-floating-point. */ | |
2839 | else if (TREE_CODE (arg0) == MINUS_EXPR && TREE_CODE (type) != REAL_TYPE) | |
2840 | return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1), | |
2841 | TREE_OPERAND (arg0, 0)); | |
2842 | ||
2843 | return t; | |
2844 | ||
2845 | case ABS_EXPR: | |
2846 | if (wins) | |
2847 | { | |
2848 | if (TREE_CODE (arg0) == INTEGER_CST) | |
2849 | { | |
2850 | if (! TREE_UNSIGNED (type) | |
2851 | && TREE_INT_CST_HIGH (arg0) < 0) | |
2852 | { | |
2853 | if (TREE_INT_CST_LOW (arg0) == 0) | |
2854 | t = build_int_2 (0, - TREE_INT_CST_HIGH (arg0)); | |
2855 | else | |
2856 | t = build_int_2 (- TREE_INT_CST_LOW (arg0), | |
2857 | ~ TREE_INT_CST_HIGH (arg0)); | |
2858 | } | |
2859 | } | |
2860 | else if (TREE_CODE (arg0) == REAL_CST) | |
2861 | { | |
c05a9b68 | 2862 | if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0))) |
6d716ca8 RS |
2863 | t = build_real (type, |
2864 | REAL_VALUE_NEGATE (TREE_REAL_CST (arg0))); | |
2865 | } | |
2866 | TREE_TYPE (t) = type; | |
2867 | } | |
2868 | else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR) | |
2869 | return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)); | |
2870 | return t; | |
2871 | ||
2872 | case BIT_NOT_EXPR: | |
2873 | if (wins) | |
2874 | { | |
2875 | if (TREE_CODE (arg0) == INTEGER_CST) | |
2876 | t = build_int_2 (~ TREE_INT_CST_LOW (arg0), | |
2877 | ~ TREE_INT_CST_HIGH (arg0)); | |
2878 | TREE_TYPE (t) = type; | |
2879 | force_fit_type (t); | |
2880 | } | |
2881 | else if (TREE_CODE (arg0) == BIT_NOT_EXPR) | |
2882 | return TREE_OPERAND (arg0, 0); | |
2883 | return t; | |
2884 | ||
2885 | case PLUS_EXPR: | |
2886 | /* A + (-B) -> A - B */ | |
2887 | if (TREE_CODE (arg1) == NEGATE_EXPR) | |
2888 | return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0))); | |
2889 | else if (TREE_CODE (type) != REAL_TYPE) | |
2890 | { | |
2891 | if (integer_zerop (arg1)) | |
2892 | return non_lvalue (convert (type, arg0)); | |
2893 | ||
2894 | /* If we are adding two BIT_AND_EXPR's, both of which are and'ing | |
2895 | with a constant, and the two constants have no bits in common, | |
2896 | we should treat this as a BIT_IOR_EXPR since this may produce more | |
2897 | simplifications. */ | |
2898 | if (TREE_CODE (arg0) == BIT_AND_EXPR | |
2899 | && TREE_CODE (arg1) == BIT_AND_EXPR | |
2900 | && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST | |
2901 | && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST | |
2902 | && integer_zerop (const_binop (BIT_AND_EXPR, | |
2903 | TREE_OPERAND (arg0, 1), | |
2904 | TREE_OPERAND (arg1, 1)))) | |
2905 | { | |
2906 | code = BIT_IOR_EXPR; | |
2907 | goto bit_ior; | |
2908 | } | |
2909 | } | |
2910 | /* In IEEE floating point, x+0 may not equal x. */ | |
2911 | else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT | |
2912 | && real_zerop (arg1)) | |
2913 | return non_lvalue (convert (type, arg0)); | |
2914 | associate: | |
2915 | /* In most languages, can't associate operations on floats | |
2916 | through parentheses. Rather than remember where the parentheses | |
2917 | were, we don't associate floats at all. It shouldn't matter much. */ | |
2918 | if (TREE_CODE (type) == REAL_TYPE) | |
2919 | goto binary; | |
2920 | /* The varsign == -1 cases happen only for addition and subtraction. | |
2921 | It says that the arg that was split was really CON minus VAR. | |
2922 | The rest of the code applies to all associative operations. */ | |
2923 | if (!wins) | |
2924 | { | |
c05a9b68 | 2925 | tree var, con; |
6d716ca8 RS |
2926 | int varsign; |
2927 | ||
2928 | if (split_tree (arg0, code, &var, &con, &varsign)) | |
2929 | { | |
2930 | if (varsign == -1) | |
2931 | { | |
2932 | /* EXPR is (CON-VAR) +- ARG1. */ | |
2933 | /* If it is + and VAR==ARG1, return just CONST. */ | |
2934 | if (code == PLUS_EXPR && operand_equal_p (var, arg1, 0)) | |
2935 | return convert (TREE_TYPE (t), con); | |
2936 | ||
2937 | /* Otherwise return (CON +- ARG1) - VAR. */ | |
2938 | TREE_SET_CODE (t, MINUS_EXPR); | |
2939 | TREE_OPERAND (t, 1) = var; | |
2940 | TREE_OPERAND (t, 0) | |
2941 | = fold (build (code, TREE_TYPE (t), con, arg1)); | |
2942 | } | |
2943 | else | |
2944 | { | |
2945 | /* EXPR is (VAR+CON) +- ARG1. */ | |
2946 | /* If it is - and VAR==ARG1, return just CONST. */ | |
2947 | if (code == MINUS_EXPR && operand_equal_p (var, arg1, 0)) | |
2948 | return convert (TREE_TYPE (t), con); | |
2949 | ||
2950 | /* Otherwise return VAR +- (ARG1 +- CON). */ | |
2951 | TREE_OPERAND (t, 1) = tem | |
2952 | = fold (build (code, TREE_TYPE (t), arg1, con)); | |
2953 | TREE_OPERAND (t, 0) = var; | |
2954 | if (integer_zerop (tem) | |
2955 | && (code == PLUS_EXPR || code == MINUS_EXPR)) | |
2956 | return convert (type, var); | |
2957 | /* If we have x +/- (c - d) [c an explicit integer] | |
2958 | change it to x -/+ (d - c) since if d is relocatable | |
2959 | then the latter can be a single immediate insn | |
2960 | and the former cannot. */ | |
2961 | if (TREE_CODE (tem) == MINUS_EXPR | |
2962 | && TREE_CODE (TREE_OPERAND (tem, 0)) == INTEGER_CST) | |
2963 | { | |
2964 | tree tem1 = TREE_OPERAND (tem, 1); | |
2965 | TREE_OPERAND (tem, 1) = TREE_OPERAND (tem, 0); | |
2966 | TREE_OPERAND (tem, 0) = tem1; | |
2967 | TREE_SET_CODE (t, | |
2968 | (code == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR)); | |
2969 | } | |
2970 | } | |
2971 | return t; | |
2972 | } | |
2973 | ||
2974 | if (split_tree (arg1, code, &var, &con, &varsign)) | |
2975 | { | |
2976 | /* EXPR is ARG0 +- (CON +- VAR). */ | |
2977 | if (varsign == -1) | |
2978 | TREE_SET_CODE (t, | |
2979 | (code == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR)); | |
2980 | if (TREE_CODE (t) == MINUS_EXPR | |
2981 | && operand_equal_p (var, arg0, 0)) | |
2982 | { | |
2983 | /* If VAR and ARG0 cancel, return just CON or -CON. */ | |
2984 | if (code == PLUS_EXPR) | |
2985 | return convert (TREE_TYPE (t), con); | |
2986 | return fold (build1 (NEGATE_EXPR, TREE_TYPE (t), | |
2987 | convert (TREE_TYPE (t), con))); | |
2988 | } | |
2989 | TREE_OPERAND (t, 0) | |
2990 | = fold (build (code, TREE_TYPE (t), arg0, con)); | |
2991 | TREE_OPERAND (t, 1) = var; | |
2992 | if (integer_zerop (TREE_OPERAND (t, 0)) | |
2993 | && TREE_CODE (t) == PLUS_EXPR) | |
2994 | return convert (TREE_TYPE (t), var); | |
2995 | return t; | |
2996 | } | |
2997 | } | |
2998 | binary: | |
2999 | #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC) | |
3000 | if (TREE_CODE (arg1) == REAL_CST) | |
3001 | return t; | |
3002 | #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */ | |
3003 | if (wins) | |
3004 | t1 = const_binop (code, arg0, arg1); | |
3005 | if (t1 != NULL_TREE) | |
3006 | { | |
3007 | /* The return value should always have | |
3008 | the same type as the original expression. */ | |
3009 | TREE_TYPE (t1) = TREE_TYPE (t); | |
3010 | return t1; | |
3011 | } | |
3012 | return t; | |
3013 | ||
3014 | case MINUS_EXPR: | |
3015 | if (TREE_CODE (type) != REAL_TYPE) | |
3016 | { | |
3017 | if (! wins && integer_zerop (arg0)) | |
3018 | return build1 (NEGATE_EXPR, type, arg1); | |
3019 | if (integer_zerop (arg1)) | |
3020 | return non_lvalue (convert (type, arg0)); | |
3021 | } | |
3022 | /* Convert A - (-B) to A + B. */ | |
3023 | else if (TREE_CODE (arg1) == NEGATE_EXPR) | |
3024 | return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0))); | |
c05a9b68 | 3025 | else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT) |
6d716ca8 | 3026 | { |
c05a9b68 | 3027 | /* Except with IEEE floating point, 0-x equals -x. */ |
6d716ca8 RS |
3028 | if (! wins && real_zerop (arg0)) |
3029 | return build1 (NEGATE_EXPR, type, arg1); | |
c05a9b68 RS |
3030 | /* Except with IEEE floating point, x-0 equals x. */ |
3031 | if (real_zerop (arg1)) | |
6d716ca8 | 3032 | return non_lvalue (convert (type, arg0)); |
a6acbe15 RS |
3033 | |
3034 | /* Fold &x - &x. This can happen from &x.foo - &x. | |
3035 | This is unsafe for certain floats even in non-IEEE formats. | |
3036 | In IEEE, it is unsafe because it does wrong for NaNs. | |
3037 | Also note that operand_equal_p is always false is an operand | |
3038 | is volatile. */ | |
3039 | ||
3040 | if (operand_equal_p (arg0, arg1, | |
3041 | TREE_CODE (type) == REAL_TYPE)) | |
3042 | return convert (type, integer_zero_node); | |
6d716ca8 | 3043 | } |
6d716ca8 RS |
3044 | goto associate; |
3045 | ||
3046 | case MULT_EXPR: | |
3047 | if (TREE_CODE (type) != REAL_TYPE) | |
3048 | { | |
3049 | if (integer_zerop (arg1)) | |
3050 | return omit_one_operand (type, arg1, arg0); | |
3051 | if (integer_onep (arg1)) | |
3052 | return non_lvalue (convert (type, arg0)); | |
3053 | ||
3054 | /* (a * (1 << b)) is (a << b) */ | |
3055 | if (TREE_CODE (arg1) == LSHIFT_EXPR | |
3056 | && integer_onep (TREE_OPERAND (arg1, 0))) | |
3057 | return fold (build (LSHIFT_EXPR, type, arg0, | |
3058 | TREE_OPERAND (arg1, 1))); | |
3059 | if (TREE_CODE (arg0) == LSHIFT_EXPR | |
3060 | && integer_onep (TREE_OPERAND (arg0, 0))) | |
3061 | return fold (build (LSHIFT_EXPR, type, arg1, | |
3062 | TREE_OPERAND (arg0, 1))); | |
3063 | } | |
6d716ca8 RS |
3064 | else |
3065 | { | |
c05a9b68 | 3066 | /* x*0 is 0, except for IEEE floating point. */ |
6d716ca8 RS |
3067 | if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT |
3068 | && real_zerop (arg1)) | |
3069 | return omit_one_operand (type, arg1, arg0); | |
c05a9b68 | 3070 | /* In IEEE floating point, x*1 is not equivalent to x for snans. |
6d716ca8 RS |
3071 | However, ANSI says we can drop signals, |
3072 | so we can do this anyway. */ | |
3073 | if (real_onep (arg1)) | |
3074 | return non_lvalue (convert (type, arg0)); | |
3075 | /* x*2 is x+x */ | |
3076 | if (! wins && real_twop (arg1)) | |
3077 | { | |
3078 | tree arg = save_expr (arg0); | |
3079 | return build (PLUS_EXPR, type, arg, arg); | |
3080 | } | |
3081 | } | |
3082 | goto associate; | |
3083 | ||
3084 | case BIT_IOR_EXPR: | |
3085 | bit_ior: | |
3086 | if (integer_all_onesp (arg1)) | |
3087 | return omit_one_operand (type, arg1, arg0); | |
3088 | if (integer_zerop (arg1)) | |
3089 | return non_lvalue (convert (type, arg0)); | |
3090 | t1 = distribute_bit_expr (code, type, arg0, arg1); | |
3091 | if (t1 != NULL_TREE) | |
3092 | return t1; | |
3093 | goto associate; | |
3094 | ||
3095 | case BIT_XOR_EXPR: | |
3096 | if (integer_zerop (arg1)) | |
3097 | return non_lvalue (convert (type, arg0)); | |
3098 | if (integer_all_onesp (arg1)) | |
3099 | return fold (build1 (BIT_NOT_EXPR, type, arg0)); | |
3100 | goto associate; | |
3101 | ||
3102 | case BIT_AND_EXPR: | |
3103 | bit_and: | |
3104 | if (integer_all_onesp (arg1)) | |
3105 | return non_lvalue (convert (type, arg0)); | |
3106 | if (integer_zerop (arg1)) | |
3107 | return omit_one_operand (type, arg1, arg0); | |
3108 | t1 = distribute_bit_expr (code, type, arg0, arg1); | |
3109 | if (t1 != NULL_TREE) | |
3110 | return t1; | |
3111 | /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */ | |
3112 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == NOP_EXPR | |
3113 | && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0)))) | |
3114 | { | |
3115 | int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0))); | |
3116 | if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_INT | |
3117 | && (~TREE_INT_CST_LOW (arg0) & ((1 << prec) - 1)) == 0) | |
3118 | return build1 (NOP_EXPR, type, TREE_OPERAND (arg1, 0)); | |
3119 | } | |
3120 | if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR | |
3121 | && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0)))) | |
3122 | { | |
3123 | int prec = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))); | |
3124 | if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_INT | |
3125 | && (~TREE_INT_CST_LOW (arg1) & ((1 << prec) - 1)) == 0) | |
3126 | return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0)); | |
3127 | } | |
3128 | goto associate; | |
3129 | ||
3130 | case BIT_ANDTC_EXPR: | |
3131 | if (integer_all_onesp (arg0)) | |
3132 | return non_lvalue (convert (type, arg1)); | |
3133 | if (integer_zerop (arg0)) | |
3134 | return omit_one_operand (type, arg0, arg1); | |
3135 | if (TREE_CODE (arg1) == INTEGER_CST) | |
3136 | { | |
3137 | arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1)); | |
3138 | code = BIT_AND_EXPR; | |
3139 | goto bit_and; | |
3140 | } | |
3141 | goto binary; | |
3142 | ||
3143 | case TRUNC_DIV_EXPR: | |
3144 | case ROUND_DIV_EXPR: | |
3145 | case FLOOR_DIV_EXPR: | |
3146 | case CEIL_DIV_EXPR: | |
3147 | case EXACT_DIV_EXPR: | |
3148 | case RDIV_EXPR: | |
3149 | if (integer_onep (arg1)) | |
3150 | return non_lvalue (convert (type, arg0)); | |
3151 | if (integer_zerop (arg1)) | |
3152 | return t; | |
3b998c11 RK |
3153 | |
3154 | /* If we have ((a * C1) / C2) and C1 % C2 == 0, we can replace this with | |
3155 | (a * (C1/C2). Also look for when we have a SAVE_EXPR in | |
3156 | between. */ | |
3157 | if (TREE_CODE (arg1) == INTEGER_CST | |
3158 | && TREE_INT_CST_LOW (arg1) > 0 && TREE_INT_CST_HIGH (arg1) == 0 | |
3159 | && TREE_CODE (arg0) == MULT_EXPR | |
3160 | && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST | |
3161 | && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) > 0 | |
3162 | && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0 | |
3163 | && 0 == (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) | |
3164 | % TREE_INT_CST_LOW (arg1))) | |
3165 | { | |
3166 | tree new_op | |
3167 | = build_int_2 (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) | |
3168 | / TREE_INT_CST_LOW (arg1)); | |
3169 | ||
3170 | TREE_TYPE (new_op) = type; | |
3171 | return build (MULT_EXPR, type, TREE_OPERAND (arg0, 0), new_op); | |
3172 | } | |
3173 | ||
3174 | else if (TREE_CODE (arg1) == INTEGER_CST | |
3175 | && TREE_INT_CST_LOW (arg1) > 0 && TREE_INT_CST_HIGH (arg1) == 0 | |
3176 | && TREE_CODE (arg0) == SAVE_EXPR | |
3177 | && TREE_CODE (TREE_OPERAND (arg0, 0)) == MULT_EXPR | |
3178 | && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)) | |
3179 | == INTEGER_CST) | |
3180 | && (TREE_INT_CST_LOW (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)) | |
3181 | > 0) | |
3182 | && (TREE_INT_CST_HIGH (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)) | |
3183 | == 0) | |
3184 | && (TREE_INT_CST_LOW (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)) | |
3185 | % TREE_INT_CST_LOW (arg1)) == 0) | |
3186 | { | |
3187 | tree new_op | |
3188 | = build_int_2 (TREE_INT_CST_LOW (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)) | |
3189 | / TREE_INT_CST_LOW (arg1)); | |
3190 | ||
3191 | TREE_TYPE (new_op) = type; | |
3192 | return build (MULT_EXPR, type, | |
3193 | TREE_OPERAND (TREE_OPERAND (arg0, 0), 0), new_op); | |
3194 | } | |
3195 | ||
6d716ca8 RS |
3196 | #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) |
3197 | #ifndef REAL_INFINITY | |
3198 | if (TREE_CODE (arg1) == REAL_CST | |
3199 | && real_zerop (arg1)) | |
3200 | return t; | |
3201 | #endif | |
3202 | #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */ | |
3203 | ||
3204 | goto binary; | |
3205 | ||
3206 | case CEIL_MOD_EXPR: | |
3207 | case FLOOR_MOD_EXPR: | |
3208 | case ROUND_MOD_EXPR: | |
3209 | case TRUNC_MOD_EXPR: | |
3210 | if (integer_onep (arg1)) | |
3211 | return omit_one_operand (type, integer_zero_node, arg0); | |
3212 | if (integer_zerop (arg1)) | |
3213 | return t; | |
3214 | goto binary; | |
3215 | ||
3216 | case LSHIFT_EXPR: | |
3217 | case RSHIFT_EXPR: | |
3218 | case LROTATE_EXPR: | |
3219 | case RROTATE_EXPR: | |
3220 | if (integer_zerop (arg1)) | |
3221 | return non_lvalue (convert (type, arg0)); | |
3222 | /* Since negative shift count is not well-defined, | |
3223 | don't try to compute it in the compiler. */ | |
3224 | if (tree_int_cst_lt (arg1, integer_zero_node)) | |
3225 | return t; | |
3226 | goto binary; | |
3227 | ||
3228 | case MIN_EXPR: | |
3229 | if (operand_equal_p (arg0, arg1, 0)) | |
3230 | return arg0; | |
3231 | if (TREE_CODE (type) == INTEGER_TYPE | |
3232 | && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1)) | |
3233 | return omit_one_operand (type, arg1, arg0); | |
3234 | goto associate; | |
3235 | ||
3236 | case MAX_EXPR: | |
3237 | if (operand_equal_p (arg0, arg1, 0)) | |
3238 | return arg0; | |
3239 | if (TREE_CODE (type) == INTEGER_TYPE | |
3240 | && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1)) | |
3241 | return omit_one_operand (type, arg1, arg0); | |
3242 | goto associate; | |
3243 | ||
3244 | case TRUTH_NOT_EXPR: | |
3245 | /* Note that the operand of this must be an int | |
3246 | and its values must be 0 or 1. | |
3247 | ("true" is a fixed value perhaps depending on the language, | |
3248 | but we don't handle values other than 1 correctly yet.) */ | |
3249 | return invert_truthvalue (arg0); | |
3250 | ||
3251 | case TRUTH_ANDIF_EXPR: | |
3252 | /* Note that the operands of this must be ints | |
3253 | and their values must be 0 or 1. | |
3254 | ("true" is a fixed value perhaps depending on the language.) */ | |
3255 | /* If first arg is constant zero, return it. */ | |
3256 | if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0)) | |
3257 | return arg0; | |
3258 | case TRUTH_AND_EXPR: | |
3259 | /* If either arg is constant true, drop it. */ | |
3260 | if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0)) | |
3261 | return non_lvalue (arg1); | |
3262 | if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)) | |
3263 | return non_lvalue (arg0); | |
3264 | /* Both known to be zero => return zero. */ | |
3265 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST) | |
3266 | return arg0; | |
3267 | ||
3268 | truth_andor: | |
3269 | /* Check for the possibility of merging component references. If our | |
3270 | lhs is another similar operation, try to merge its rhs with our | |
3271 | rhs. Then try to merge our lhs and rhs. */ | |
3272 | if (optimize) | |
3273 | { | |
6d716ca8 RS |
3274 | if (TREE_CODE (arg0) == code) |
3275 | { | |
3276 | tem = merge_component_references (code, type, | |
3277 | TREE_OPERAND (arg0, 1), arg1); | |
3278 | if (tem) | |
3279 | return fold (build (code, type, TREE_OPERAND (arg0, 0), tem)); | |
3280 | } | |
3281 | ||
3282 | tem = merge_component_references (code, type, arg0, arg1); | |
3283 | if (tem) | |
3284 | return tem; | |
3285 | } | |
3286 | return t; | |
3287 | ||
3288 | case TRUTH_ORIF_EXPR: | |
3289 | /* Note that the operands of this must be ints | |
3290 | and their values must be 0 or true. | |
3291 | ("true" is a fixed value perhaps depending on the language.) */ | |
3292 | /* If first arg is constant true, return it. */ | |
3293 | if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0)) | |
3294 | return arg0; | |
3295 | case TRUTH_OR_EXPR: | |
3296 | /* If either arg is constant zero, drop it. */ | |
3297 | if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0)) | |
3298 | return non_lvalue (arg1); | |
3299 | if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)) | |
3300 | return non_lvalue (arg0); | |
3301 | /* Both known to be true => return true. */ | |
3302 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST) | |
3303 | return arg0; | |
3304 | goto truth_andor; | |
3305 | ||
3306 | case EQ_EXPR: | |
3307 | case NE_EXPR: | |
3308 | case LT_EXPR: | |
3309 | case GT_EXPR: | |
3310 | case LE_EXPR: | |
3311 | case GE_EXPR: | |
3312 | /* If one arg is a constant integer, put it last. */ | |
3313 | if (TREE_CODE (arg0) == INTEGER_CST | |
3314 | && TREE_CODE (arg1) != INTEGER_CST) | |
3315 | { | |
3316 | TREE_OPERAND (t, 0) = arg1; | |
3317 | TREE_OPERAND (t, 1) = arg0; | |
3318 | arg0 = TREE_OPERAND (t, 0); | |
3319 | arg1 = TREE_OPERAND (t, 1); | |
c05a9b68 | 3320 | code = swap_tree_comparison (code); |
6d716ca8 RS |
3321 | TREE_SET_CODE (t, code); |
3322 | } | |
3323 | ||
3324 | /* Convert foo++ == CONST into ++foo == CONST + INCR. | |
3325 | First, see if one arg is constant; find the constant arg | |
3326 | and the other one. */ | |
3327 | { | |
3328 | tree constop = 0, varop; | |
3329 | tree *constoploc; | |
3330 | ||
3331 | if (TREE_CONSTANT (arg1)) | |
3332 | constoploc = &TREE_OPERAND (t, 1), constop = arg1, varop = arg0; | |
3333 | if (TREE_CONSTANT (arg0)) | |
3334 | constoploc = &TREE_OPERAND (t, 0), constop = arg0, varop = arg1; | |
3335 | ||
3336 | if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR) | |
3337 | { | |
6d716ca8 RS |
3338 | /* This optimization is invalid for ordered comparisons |
3339 | if CONST+INCR overflows or if foo+incr might overflow. | |
c05a9b68 | 3340 | This optimization is invalid for floating point due to rounding. |
6d716ca8 RS |
3341 | For pointer types we assume overflow doesn't happen. */ |
3342 | if (TREE_CODE (TREE_TYPE (varop)) == POINTER_TYPE | |
c05a9b68 RS |
3343 | || (TREE_CODE (TREE_TYPE (varop)) != REAL_TYPE |
3344 | && (code == EQ_EXPR || code == NE_EXPR))) | |
6d716ca8 | 3345 | { |
c05a9b68 RS |
3346 | tree newconst |
3347 | = fold (build (PLUS_EXPR, TREE_TYPE (varop), | |
3348 | constop, TREE_OPERAND (varop, 1))); | |
3349 | TREE_SET_CODE (varop, PREINCREMENT_EXPR); | |
3350 | *constoploc = newconst; | |
3351 | return t; | |
6d716ca8 RS |
3352 | } |
3353 | } | |
3354 | else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR) | |
3355 | { | |
6d716ca8 | 3356 | if (TREE_CODE (TREE_TYPE (varop)) == POINTER_TYPE |
c05a9b68 RS |
3357 | || (TREE_CODE (TREE_TYPE (varop)) != REAL_TYPE |
3358 | && (code == EQ_EXPR || code == NE_EXPR))) | |
6d716ca8 | 3359 | { |
c05a9b68 RS |
3360 | tree newconst |
3361 | = fold (build (MINUS_EXPR, TREE_TYPE (varop), | |
3362 | constop, TREE_OPERAND (varop, 1))); | |
3363 | TREE_SET_CODE (varop, PREDECREMENT_EXPR); | |
3364 | *constoploc = newconst; | |
3365 | return t; | |
6d716ca8 RS |
3366 | } |
3367 | } | |
3368 | } | |
3369 | ||
3370 | /* Change X >= CST to X > (CST - 1) if CST is positive. */ | |
3371 | if (TREE_CODE (arg1) == INTEGER_CST | |
3372 | && TREE_CODE (arg0) != INTEGER_CST | |
3373 | && ! tree_int_cst_lt (arg1, integer_one_node)) | |
3374 | { | |
3375 | switch (TREE_CODE (t)) | |
3376 | { | |
3377 | case GE_EXPR: | |
3378 | code = GT_EXPR; | |
3379 | TREE_SET_CODE (t, code); | |
3380 | arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node); | |
3381 | TREE_OPERAND (t, 1) = arg1; | |
3382 | break; | |
3383 | ||
3384 | case LT_EXPR: | |
3385 | code = LE_EXPR; | |
3386 | TREE_SET_CODE (t, code); | |
3387 | arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node); | |
3388 | TREE_OPERAND (t, 1) = arg1; | |
3389 | } | |
3390 | } | |
3391 | ||
6d716ca8 RS |
3392 | /* If this is an EQ or NE comparison with zero and ARG0 is |
3393 | (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require | |
3394 | two operations, but the latter can be done in one less insn | |
3395 | one machine that have only two-operand insns or on which a | |
3396 | constant cannot be the first operand. */ | |
3397 | if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR) | |
3398 | && TREE_CODE (arg0) == BIT_AND_EXPR) | |
3399 | { | |
3400 | if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR | |
3401 | && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0))) | |
3402 | return | |
3403 | fold (build (code, type, | |
3404 | build (BIT_AND_EXPR, TREE_TYPE (arg0), | |
3405 | build (RSHIFT_EXPR, | |
3406 | TREE_TYPE (TREE_OPERAND (arg0, 0)), | |
3407 | TREE_OPERAND (arg0, 1), | |
3408 | TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)), | |
3409 | convert (TREE_TYPE (arg0), | |
3410 | integer_one_node)), | |
3411 | arg1)); | |
3412 | else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR | |
3413 | && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0))) | |
3414 | return | |
3415 | fold (build (code, type, | |
3416 | build (BIT_AND_EXPR, TREE_TYPE (arg0), | |
3417 | build (RSHIFT_EXPR, | |
3418 | TREE_TYPE (TREE_OPERAND (arg0, 1)), | |
3419 | TREE_OPERAND (arg0, 0), | |
3420 | TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)), | |
3421 | convert (TREE_TYPE (arg0), | |
3422 | integer_one_node)), | |
3423 | arg1)); | |
3424 | } | |
3425 | ||
3426 | /* If this is an NE comparison of zero with an AND of one, remove the | |
3427 | comparison since the AND will give the correct value. */ | |
3428 | if (code == NE_EXPR && integer_zerop (arg1) | |
3429 | && TREE_CODE (arg0) == BIT_AND_EXPR | |
3430 | && integer_onep (TREE_OPERAND (arg0, 1))) | |
3431 | return convert (type, arg0); | |
3432 | ||
3433 | /* If we have (A & C) == C where C is a power of 2, convert this into | |
3434 | (A & C) != 0. Similarly for NE_EXPR. */ | |
3435 | if ((code == EQ_EXPR || code == NE_EXPR) | |
3436 | && TREE_CODE (arg0) == BIT_AND_EXPR | |
3437 | && integer_pow2p (TREE_OPERAND (arg0, 1)) | |
3438 | && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0)) | |
3439 | return build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type, | |
3440 | arg0, integer_zero_node); | |
3441 | ||
c05a9b68 RS |
3442 | /* Simplify comparison of something with itself. (For IEEE |
3443 | floating-point, we can only do some of these simplifications.) */ | |
3444 | if (operand_equal_p (arg0, arg1, 0)) | |
6d716ca8 RS |
3445 | { |
3446 | switch (code) | |
3447 | { | |
3448 | case EQ_EXPR: | |
3449 | case GE_EXPR: | |
3450 | case LE_EXPR: | |
c05a9b68 RS |
3451 | if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE) |
3452 | { | |
3453 | t = build_int_2 (1, 0); | |
3454 | TREE_TYPE (t) = type; | |
3455 | return t; | |
3456 | } | |
3457 | code = EQ_EXPR; | |
3458 | TREE_SET_CODE (t, code); | |
3459 | break; | |
3460 | ||
6d716ca8 | 3461 | case NE_EXPR: |
c05a9b68 RS |
3462 | /* For NE, we can only do this simplification if integer. */ |
3463 | if (TREE_CODE (TREE_TYPE (arg0)) != INTEGER_TYPE) | |
3464 | break; | |
3465 | /* ... fall through ... */ | |
6d716ca8 RS |
3466 | case GT_EXPR: |
3467 | case LT_EXPR: | |
3468 | t = build_int_2 (0, 0); | |
3469 | TREE_TYPE (t) = type; | |
3470 | return t; | |
3471 | } | |
3472 | } | |
3473 | ||
3474 | /* An unsigned comparison against 0 can be simplified. */ | |
3475 | if (integer_zerop (arg1) | |
3476 | && (TREE_CODE (TREE_TYPE (arg1)) == INTEGER_TYPE | |
3477 | || TREE_CODE (TREE_TYPE (arg1)) == POINTER_TYPE) | |
3478 | && TREE_UNSIGNED (TREE_TYPE (arg1))) | |
3479 | { | |
3480 | switch (TREE_CODE (t)) | |
3481 | { | |
3482 | case GT_EXPR: | |
c05a9b68 | 3483 | code = NE_EXPR; |
6d716ca8 RS |
3484 | TREE_SET_CODE (t, NE_EXPR); |
3485 | break; | |
3486 | case LE_EXPR: | |
c05a9b68 | 3487 | code = EQ_EXPR; |
6d716ca8 RS |
3488 | TREE_SET_CODE (t, EQ_EXPR); |
3489 | break; | |
3490 | case GE_EXPR: | |
3491 | return omit_one_operand (integer_type_node, | |
3492 | integer_one_node, arg0); | |
3493 | case LT_EXPR: | |
3494 | return omit_one_operand (integer_type_node, | |
3495 | integer_zero_node, arg0); | |
3496 | } | |
3497 | } | |
3498 | ||
c05a9b68 RS |
3499 | /* If we are comparing an expression that just has comparisons |
3500 | of two integer values, arithmetic expressions of those comparisons, | |
3501 | and constants, we can simplify it. There are only three cases | |
3502 | to check: the two values can either be equal, the first can be | |
3503 | greater, or the second can be greater. Fold the expression for | |
3504 | those three values. Since each value must be 0 or 1, we have | |
3505 | eight possibilities, each of which corresponds to the constant 0 | |
3506 | or 1 or one of the six possible comparisons. | |
3507 | ||
3508 | This handles common cases like (a > b) == 0 but also handles | |
3509 | expressions like ((x > y) - (y > x)) > 0, which supposedly | |
3510 | occur in macroized code. */ | |
3511 | ||
3512 | if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST) | |
3513 | { | |
3514 | tree cval1 = 0, cval2 = 0; | |
3515 | ||
3516 | if (twoval_comparison_p (arg0, &cval1, &cval2) | |
3517 | /* Don't handle degenerate cases here; they should already | |
3518 | have been handled anyway. */ | |
3519 | && cval1 != 0 && cval2 != 0 | |
3520 | && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2)) | |
3521 | && TREE_TYPE (cval1) == TREE_TYPE (cval2) | |
3522 | && TREE_CODE (TREE_TYPE (cval1)) == INTEGER_TYPE | |
3523 | && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)), | |
3524 | TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0)) | |
3525 | { | |
3526 | tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1)); | |
3527 | tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1)); | |
3528 | ||
3529 | /* We can't just pass T to eval_subst in case cval1 or cval2 | |
3530 | was the same as ARG1. */ | |
3531 | ||
3532 | tree high_result | |
3533 | = fold (build (code, type, | |
3534 | eval_subst (arg0, cval1, maxval, cval2, minval), | |
3535 | arg1)); | |
3536 | tree equal_result | |
3537 | = fold (build (code, type, | |
3538 | eval_subst (arg0, cval1, maxval, cval2, maxval), | |
3539 | arg1)); | |
3540 | tree low_result | |
3541 | = fold (build (code, type, | |
3542 | eval_subst (arg0, cval1, minval, cval2, maxval), | |
3543 | arg1)); | |
3544 | ||
3545 | /* All three of these results should be 0 or 1. Confirm they | |
3546 | are. Then use those values to select the proper code | |
3547 | to use. */ | |
3548 | ||
3549 | if ((integer_zerop (high_result) | |
3550 | || integer_onep (high_result)) | |
3551 | && (integer_zerop (equal_result) | |
3552 | || integer_onep (equal_result)) | |
3553 | && (integer_zerop (low_result) | |
3554 | || integer_onep (low_result))) | |
3555 | { | |
3556 | /* Make a 3-bit mask with the high-order bit being the | |
3557 | value for `>', the next for '=', and the low for '<'. */ | |
3558 | switch ((integer_onep (high_result) * 4) | |
3559 | + (integer_onep (equal_result) * 2) | |
3560 | + integer_onep (low_result)) | |
3561 | { | |
3562 | case 0: | |
3563 | /* Always false. */ | |
13837058 | 3564 | return omit_one_operand (type, integer_zero_node, arg0); |
c05a9b68 RS |
3565 | case 1: |
3566 | code = LT_EXPR; | |
3567 | break; | |
3568 | case 2: | |
3569 | code = EQ_EXPR; | |
3570 | break; | |
3571 | case 3: | |
3572 | code = LE_EXPR; | |
3573 | break; | |
3574 | case 4: | |
3575 | code = GT_EXPR; | |
3576 | break; | |
3577 | case 5: | |
3578 | code = NE_EXPR; | |
3579 | break; | |
3580 | case 6: | |
3581 | code = GE_EXPR; | |
3582 | break; | |
3583 | case 7: | |
3584 | /* Always true. */ | |
13837058 | 3585 | return omit_one_operand (type, integer_one_node, arg0); |
c05a9b68 RS |
3586 | } |
3587 | ||
95ca4f96 | 3588 | return fold (build (code, type, cval1, cval2)); |
c05a9b68 RS |
3589 | } |
3590 | } | |
3591 | } | |
3592 | ||
3593 | /* If this is a comparison of a field, we may be able to simplify it. */ | |
3594 | if ((TREE_CODE (arg0) == COMPONENT_REF | |
3595 | || TREE_CODE (arg0) == BIT_FIELD_REF) | |
3596 | && (code == EQ_EXPR || code == NE_EXPR) | |
3597 | /* Handle the constant case even without -O | |
3598 | to make sure the warnings are given. */ | |
3599 | && (optimize || TREE_CODE (arg1) == INTEGER_CST)) | |
3600 | { | |
3601 | t1 = optimize_bit_field_compare (code, type, arg0, arg1); | |
3602 | return t1 ? t1 : t; | |
3603 | } | |
3604 | ||
3605 | /* From here on, the only cases we handle are when the result is | |
3606 | known to be a constant. | |
3607 | ||
3608 | To compute GT, swap the arguments and do LT. | |
6d716ca8 RS |
3609 | To compute GE, do LT and invert the result. |
3610 | To compute LE, swap the arguments, do LT and invert the result. | |
c05a9b68 RS |
3611 | To compute NE, do EQ and invert the result. |
3612 | ||
3613 | Therefore, the code below must handle only EQ and LT. */ | |
3614 | ||
6d716ca8 RS |
3615 | if (code == LE_EXPR || code == GT_EXPR) |
3616 | { | |
c05a9b68 RS |
3617 | tem = arg0, arg0 = arg1, arg1 = tem; |
3618 | code = swap_tree_comparison (code); | |
3619 | } | |
3620 | ||
3621 | /* Note that it is safe to invert for real values here because we | |
3622 | will check below in the one case that it matters. */ | |
3623 | ||
3624 | invert = 0; | |
3625 | if (code == NE_EXPR || code == GE_EXPR) | |
3626 | { | |
3627 | invert = 1; | |
3628 | code = invert_tree_comparison (code); | |
6d716ca8 RS |
3629 | } |
3630 | ||
3631 | /* Compute a result for LT or EQ if args permit; | |
3632 | otherwise return T. */ | |
c05a9b68 | 3633 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST) |
6d716ca8 | 3634 | { |
c05a9b68 RS |
3635 | if (code == EQ_EXPR) |
3636 | t1 = build_int_2 ((TREE_INT_CST_LOW (arg0) | |
3637 | == TREE_INT_CST_LOW (arg1)) | |
3638 | && (TREE_INT_CST_HIGH (arg0) | |
3639 | == TREE_INT_CST_HIGH (arg1)), | |
3640 | 0); | |
6d716ca8 | 3641 | else |
c05a9b68 RS |
3642 | t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0)) |
3643 | ? INT_CST_LT_UNSIGNED (arg0, arg1) | |
3644 | : INT_CST_LT (arg0, arg1)), | |
3645 | 0); | |
6d716ca8 | 3646 | } |
c05a9b68 | 3647 | |
6d716ca8 RS |
3648 | /* Assume a nonexplicit constant cannot equal an explicit one, |
3649 | since such code would be undefined anyway. | |
3650 | Exception: on sysvr4, using #pragma weak, | |
3651 | a label can come out as 0. */ | |
3652 | else if (TREE_CODE (arg1) == INTEGER_CST | |
3653 | && !integer_zerop (arg1) | |
3654 | && TREE_CONSTANT (arg0) | |
3655 | && TREE_CODE (arg0) == ADDR_EXPR | |
c05a9b68 RS |
3656 | && code == EQ_EXPR) |
3657 | t1 = build_int_2 (0, 0); | |
3658 | ||
6d716ca8 | 3659 | /* Two real constants can be compared explicitly. */ |
c05a9b68 | 3660 | else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST) |
6d716ca8 | 3661 | { |
c05a9b68 RS |
3662 | /* If either operand is a NaN, the result is false with two |
3663 | exceptions: First, an NE_EXPR is true on NaNs, but that case | |
3664 | is already handled correctly since we will be inverting the | |
3665 | result for NE_EXPR. Second, if we had inverted a LE_EXPR | |
3666 | or a GE_EXPR into a LT_EXPR, we must return true so that it | |
3667 | will be inverted into false. */ | |
3668 | ||
3669 | if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0)) | |
3670 | || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))) | |
3671 | t1 = build_int_2 (invert && code == LT_EXPR, 0); | |
3672 | ||
3673 | else if (code == EQ_EXPR) | |
3674 | t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0), | |
3675 | TREE_REAL_CST (arg1)), | |
3676 | 0); | |
6d716ca8 | 3677 | else |
c05a9b68 RS |
3678 | t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0), |
3679 | TREE_REAL_CST (arg1)), | |
3680 | 0); | |
6d716ca8 RS |
3681 | } |
3682 | ||
c05a9b68 RS |
3683 | if (t1 == NULL_TREE) |
3684 | return t; | |
3685 | ||
3686 | if (invert) | |
3687 | TREE_INT_CST_LOW (t1) ^= 1; | |
3688 | ||
3689 | TREE_TYPE (t1) = type; | |
3690 | return t1; | |
6d716ca8 RS |
3691 | |
3692 | case COND_EXPR: | |
3693 | if (TREE_CODE (arg0) == INTEGER_CST) | |
3694 | return TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)); | |
3695 | else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0)) | |
3696 | return omit_one_operand (type, arg1, arg0); | |
6d716ca8 | 3697 | |
c05a9b68 RS |
3698 | /* If the second operand is zero, invert the comparison and swap |
3699 | the second and third operands. Likewise if the second operand | |
3700 | is constant and the third is not or if the third operand is | |
3701 | equivalent to the first operand of the comparison. */ | |
6d716ca8 | 3702 | |
c05a9b68 RS |
3703 | if (integer_zerop (arg1) |
3704 | || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2))) | |
3705 | || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<' | |
3706 | && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0), | |
3707 | TREE_OPERAND (t, 2), | |
3708 | TREE_OPERAND (arg0, 1)))) | |
3709 | { | |
3710 | /* See if this can be inverted. If it can't, possibly because | |
3711 | it was a floating-point inequality comparison, don't do | |
3712 | anything. */ | |
3713 | tem = invert_truthvalue (arg0); | |
6d716ca8 | 3714 | |
c05a9b68 RS |
3715 | if (TREE_CODE (tem) != TRUTH_NOT_EXPR) |
3716 | { | |
3717 | arg0 = TREE_OPERAND (t, 0) = tem; | |
3718 | TREE_OPERAND (t, 1) = TREE_OPERAND (t, 2); | |
3719 | TREE_OPERAND (t, 2) = arg1; | |
3720 | arg1 = TREE_OPERAND (t, 1); | |
3721 | } | |
3722 | } | |
6d716ca8 | 3723 | |
c05a9b68 RS |
3724 | /* If we have A op B ? A : C, we may be able to convert this to a |
3725 | simpler expression, depending on the operation and the values | |
3726 | of B and C. */ | |
6d716ca8 | 3727 | |
c05a9b68 RS |
3728 | if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<' |
3729 | && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0), | |
3730 | arg1, TREE_OPERAND (arg0, 1))) | |
6d716ca8 | 3731 | { |
c05a9b68 RS |
3732 | tree arg2 = TREE_OPERAND (t, 2); |
3733 | enum tree_code comp_code = TREE_CODE (arg0); | |
3734 | ||
3735 | /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A), | |
3736 | depending on the comparison operation. */ | |
3737 | if (integer_zerop (TREE_OPERAND (arg0, 1)) | |
3738 | && TREE_CODE (arg2) == NEGATE_EXPR | |
3739 | && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0)) | |
3740 | switch (comp_code) | |
3741 | { | |
3742 | case EQ_EXPR: | |
3743 | return fold (build1 (NEGATE_EXPR, type, arg1)); | |
3744 | case NE_EXPR: | |
cdc54cc9 | 3745 | return convert (type, arg1); |
c05a9b68 RS |
3746 | case GE_EXPR: |
3747 | case GT_EXPR: | |
3748 | return fold (build1 (ABS_EXPR, type, arg1)); | |
3749 | case LE_EXPR: | |
3750 | case LT_EXPR: | |
3751 | return fold (build1 (NEGATE_EXPR, type, | |
3752 | fold (build1 (ABS_EXPR, type, arg1)))); | |
3753 | } | |
6d716ca8 | 3754 | |
c05a9b68 RS |
3755 | /* If this is A != 0 ? A : 0, this is simply A. For ==, it is |
3756 | always zero. */ | |
6d716ca8 | 3757 | |
29ebe69a | 3758 | if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2)) |
c05a9b68 RS |
3759 | { |
3760 | if (comp_code == NE_EXPR) | |
cdc54cc9 | 3761 | return convert (type, arg1); |
c05a9b68 RS |
3762 | else if (comp_code == EQ_EXPR) |
3763 | return convert (type, integer_zero_node); | |
3764 | } | |
3765 | ||
3766 | /* If this is A op B ? A : B, this is either A, B, min (A, B), | |
3767 | or max (A, B), depending on the operation. */ | |
3768 | ||
3769 | if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1), | |
3770 | arg2, TREE_OPERAND (arg0, 0))) | |
3771 | switch (comp_code) | |
3772 | { | |
3773 | case EQ_EXPR: | |
cdc54cc9 | 3774 | return convert (type, arg2); |
c05a9b68 | 3775 | case NE_EXPR: |
cdc54cc9 | 3776 | return convert (type, arg1); |
c05a9b68 RS |
3777 | case LE_EXPR: |
3778 | case LT_EXPR: | |
3779 | return fold (build (MIN_EXPR, type, arg1, arg2)); | |
3780 | case GE_EXPR: | |
3781 | case GT_EXPR: | |
3782 | return fold (build (MAX_EXPR, type, arg1, arg2)); | |
3783 | } | |
3784 | ||
3785 | /* If this is A op C1 ? A : C2 with C1 and C2 constant integers, | |
3786 | we might still be able to simplify this. For example, | |
3787 | if C1 is one less or one more than C2, this might have started | |
3788 | out as a MIN or MAX and been transformed by this function. */ | |
3789 | ||
3790 | if (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST | |
3791 | && TREE_CODE (arg2) == INTEGER_CST) | |
3792 | switch (comp_code) | |
3793 | { | |
3794 | case EQ_EXPR: | |
3795 | /* We can replace A with C1 in this case. */ | |
3796 | arg1 = TREE_OPERAND (t, 1) | |
3797 | = convert (type, TREE_OPERAND (arg0, 1)); | |
3798 | break; | |
3799 | ||
3800 | case LT_EXPR: | |
3801 | /* If C1 is C2 + 1, this is min(A, C2). */ | |
3802 | if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1) | |
3803 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
3804 | const_binop (PLUS_EXPR, arg2, | |
3805 | integer_one_node), 1)) | |
3806 | return fold (build (MIN_EXPR, type, arg1, arg2)); | |
3807 | break; | |
3808 | ||
3809 | case LE_EXPR: | |
3810 | /* If C1 is C2 - 1, this is min(A, C2). */ | |
3811 | if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1) | |
3812 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
3813 | const_binop (MINUS_EXPR, arg2, | |
3814 | integer_one_node), 1)) | |
3815 | return fold (build (MIN_EXPR, type, arg1, arg2)); | |
3816 | break; | |
3817 | ||
3818 | case GT_EXPR: | |
3819 | /* If C1 is C2 - 1, this is max(A, C2). */ | |
3820 | if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1) | |
3821 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
3822 | const_binop (MINUS_EXPR, arg2, | |
3823 | integer_one_node), 1)) | |
3824 | return fold (build (MAX_EXPR, type, arg1, arg2)); | |
3825 | break; | |
3826 | ||
3827 | case GE_EXPR: | |
3828 | /* If C1 is C2 + 1, this is max(A, C2). */ | |
3829 | if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1) | |
3830 | && operand_equal_p (TREE_OPERAND (arg0, 1), | |
3831 | const_binop (PLUS_EXPR, arg2, | |
3832 | integer_one_node), 1)) | |
3833 | return fold (build (MAX_EXPR, type, arg1, arg2)); | |
3834 | break; | |
3835 | } | |
6d716ca8 RS |
3836 | } |
3837 | ||
c05a9b68 RS |
3838 | /* Convert A ? 1 : 0 to simply A. */ |
3839 | if (integer_onep (TREE_OPERAND (t, 1)) | |
3840 | && integer_zerop (TREE_OPERAND (t, 2)) | |
3841 | /* If we try to convert TREE_OPERAND (t, 0) to our type, the | |
3842 | call to fold will try to move the conversion inside | |
3843 | a COND, which will recurse. In that case, the COND_EXPR | |
3844 | is probably the best choice, so leave it alone. */ | |
3845 | && type == TREE_TYPE (arg0)) | |
3846 | return arg0; | |
6d716ca8 | 3847 | |
6d716ca8 | 3848 | |
c05a9b68 RS |
3849 | /* Look for expressions of the form A & 2 ? 2 : 0. The result of this |
3850 | operation is simply A & 2. */ | |
6d716ca8 RS |
3851 | |
3852 | if (integer_zerop (TREE_OPERAND (t, 2)) | |
3853 | && TREE_CODE (arg0) == NE_EXPR | |
3854 | && integer_zerop (TREE_OPERAND (arg0, 1)) | |
c05a9b68 RS |
3855 | && integer_pow2p (arg1) |
3856 | && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR | |
3857 | && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1), | |
3858 | arg1, 1)) | |
3859 | return convert (type, TREE_OPERAND (arg0, 0)); | |
6d716ca8 | 3860 | |
6d716ca8 RS |
3861 | return t; |
3862 | ||
3863 | case COMPOUND_EXPR: | |
3864 | if (!TREE_SIDE_EFFECTS (arg0)) | |
3865 | return arg1; | |
3866 | return t; | |
3867 | ||
3868 | default: | |
3869 | return t; | |
3870 | } /* switch (code) */ | |
3871 | } |