1 | /* Operations with affine combinations of trees. |
2 | Copyright (C) 2005-2017 Free Software Foundation, Inc. |
3 | |
4 | This file is part of GCC. |
5 | |
6 | GCC is free software; you can redistribute it and/or modify it |
7 | under the terms of the GNU General Public License as published by the |
8 | Free Software Foundation; either version 3, or (at your option) any |
9 | later version. |
10 | |
11 | GCC is distributed in the hope that it will be useful, but WITHOUT |
12 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
14 | for more details. |
15 | |
16 | You should have received a copy of the GNU General Public License |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ |
19 | |
20 | #include "config.h" |
21 | #include "system.h" |
22 | #include "coretypes.h" |
23 | #include "backend.h" |
24 | #include "rtl.h" |
25 | #include "tree.h" |
26 | #include "gimple.h" |
27 | #include "ssa.h" |
28 | #include "tree-pretty-print.h" |
29 | #include "fold-const.h" |
30 | #include "tree-affine.h" |
31 | #include "gimplify.h" |
32 | #include "dumpfile.h" |
33 | #include "cfgexpand.h" |
34 | |
35 | /* Extends CST as appropriate for the affine combinations COMB. */ |
36 | |
37 | widest_int |
38 | wide_int_ext_for_comb (const widest_int &cst, tree type) |
39 | { |
40 | return wi::sext (cst, TYPE_PRECISION (type)); |
41 | } |
42 | |
43 | /* Initializes affine combination COMB so that its value is zero in TYPE. */ |
44 | |
45 | static void |
46 | aff_combination_zero (aff_tree *comb, tree type) |
47 | { |
48 | int i; |
49 | comb->type = type; |
50 | comb->offset = 0; |
51 | comb->n = 0; |
52 | for (i = 0; i < MAX_AFF_ELTS; i++) |
53 | comb->elts[i].coef = 0; |
54 | comb->rest = NULL_TREE; |
55 | } |
56 | |
57 | /* Sets COMB to CST. */ |
58 | |
59 | void |
60 | aff_combination_const (aff_tree *comb, tree type, const widest_int &cst) |
61 | { |
62 | aff_combination_zero (comb, type); |
63 | comb->offset = wide_int_ext_for_comb (cst, comb->type);; |
64 | } |
65 | |
66 | /* Sets COMB to single element ELT. */ |
67 | |
68 | void |
69 | aff_combination_elt (aff_tree *comb, tree type, tree elt) |
70 | { |
71 | aff_combination_zero (comb, type); |
72 | |
73 | comb->n = 1; |
74 | comb->elts[0].val = elt; |
75 | comb->elts[0].coef = 1; |
76 | } |
77 | |
78 | /* Scales COMB by SCALE. */ |
79 | |
80 | void |
81 | aff_combination_scale (aff_tree *comb, const widest_int &scale_in) |
82 | { |
83 | unsigned i, j; |
84 | |
85 | widest_int scale = wide_int_ext_for_comb (scale_in, comb->type); |
86 | if (scale == 1) |
87 | return; |
88 | |
89 | if (scale == 0) |
90 | { |
91 | aff_combination_zero (comb, comb->type); |
92 | return; |
93 | } |
94 | |
95 | comb->offset = wide_int_ext_for_comb (scale * comb->offset, comb->type); |
96 | for (i = 0, j = 0; i < comb->n; i++) |
97 | { |
98 | widest_int new_coef |
99 | = wide_int_ext_for_comb (scale * comb->elts[i].coef, comb->type); |
100 | /* A coefficient may become zero due to overflow. Remove the zero |
101 | elements. */ |
102 | if (new_coef == 0) |
103 | continue; |
104 | comb->elts[j].coef = new_coef; |
105 | comb->elts[j].val = comb->elts[i].val; |
106 | j++; |
107 | } |
108 | comb->n = j; |
109 | |
110 | if (comb->rest) |
111 | { |
112 | tree type = comb->type; |
113 | if (POINTER_TYPE_P (type)) |
114 | type = sizetype; |
115 | if (comb->n < MAX_AFF_ELTS) |
116 | { |
117 | comb->elts[comb->n].coef = scale; |
118 | comb->elts[comb->n].val = comb->rest; |
119 | comb->rest = NULL_TREE; |
120 | comb->n++; |
121 | } |
122 | else |
123 | comb->rest = fold_build2 (MULT_EXPR, type, comb->rest, |
124 | wide_int_to_tree (type, scale)); |
125 | } |
126 | } |
127 | |
128 | /* Adds ELT * SCALE to COMB. */ |
129 | |
130 | void |
131 | aff_combination_add_elt (aff_tree *comb, tree elt, const widest_int &scale_in) |
132 | { |
133 | unsigned i; |
134 | tree type; |
135 | |
136 | widest_int scale = wide_int_ext_for_comb (scale_in, comb->type); |
137 | if (scale == 0) |
138 | return; |
139 | |
140 | for (i = 0; i < comb->n; i++) |
141 | if (operand_equal_p (comb->elts[i].val, elt, 0)) |
142 | { |
143 | widest_int new_coef |
144 | = wide_int_ext_for_comb (comb->elts[i].coef + scale, comb->type); |
145 | if (new_coef != 0) |
146 | { |
147 | comb->elts[i].coef = new_coef; |
148 | return; |
149 | } |
150 | |
151 | comb->n--; |
152 | comb->elts[i] = comb->elts[comb->n]; |
153 | |
154 | if (comb->rest) |
155 | { |
156 | gcc_assert (comb->n == MAX_AFF_ELTS - 1); |
157 | comb->elts[comb->n].coef = 1; |
158 | comb->elts[comb->n].val = comb->rest; |
159 | comb->rest = NULL_TREE; |
160 | comb->n++; |
161 | } |
162 | return; |
163 | } |
164 | if (comb->n < MAX_AFF_ELTS) |
165 | { |
166 | comb->elts[comb->n].coef = scale; |
167 | comb->elts[comb->n].val = elt; |
168 | comb->n++; |
169 | return; |
170 | } |
171 | |
172 | type = comb->type; |
173 | if (POINTER_TYPE_P (type)) |
174 | type = sizetype; |
175 | |
176 | if (scale == 1) |
177 | elt = fold_convert (type, elt); |
178 | else |
179 | elt = fold_build2 (MULT_EXPR, type, |
180 | fold_convert (type, elt), |
181 | wide_int_to_tree (type, scale)); |
182 | |
183 | if (comb->rest) |
184 | comb->rest = fold_build2 (PLUS_EXPR, type, comb->rest, |
185 | elt); |
186 | else |
187 | comb->rest = elt; |
188 | } |
189 | |
190 | /* Adds CST to C. */ |
191 | |
192 | static void |
193 | aff_combination_add_cst (aff_tree *c, const widest_int &cst) |
194 | { |
195 | c->offset = wide_int_ext_for_comb (c->offset + cst, c->type); |
196 | } |
197 | |
198 | /* Adds COMB2 to COMB1. */ |
199 | |
200 | void |
201 | aff_combination_add (aff_tree *comb1, aff_tree *comb2) |
202 | { |
203 | unsigned i; |
204 | |
205 | aff_combination_add_cst (comb1, comb2->offset); |
206 | for (i = 0; i < comb2->n; i++) |
207 | aff_combination_add_elt (comb1, comb2->elts[i].val, comb2->elts[i].coef); |
208 | if (comb2->rest) |
209 | aff_combination_add_elt (comb1, comb2->rest, 1); |
210 | } |
211 | |
212 | /* Converts affine combination COMB to TYPE. */ |
213 | |
214 | void |
215 | aff_combination_convert (aff_tree *comb, tree type) |
216 | { |
217 | unsigned i, j; |
218 | tree comb_type = comb->type; |
219 | |
220 | if (TYPE_PRECISION (type) > TYPE_PRECISION (comb_type)) |
221 | { |
222 | tree val = fold_convert (type, aff_combination_to_tree (comb)); |
223 | tree_to_aff_combination (val, type, comb); |
224 | return; |
225 | } |
226 | |
227 | comb->type = type; |
228 | if (comb->rest && !POINTER_TYPE_P (type)) |
229 | comb->rest = fold_convert (type, comb->rest); |
230 | |
231 | if (TYPE_PRECISION (type) == TYPE_PRECISION (comb_type)) |
232 | return; |
233 | |
234 | comb->offset = wide_int_ext_for_comb (comb->offset, comb->type); |
235 | for (i = j = 0; i < comb->n; i++) |
236 | { |
237 | if (comb->elts[i].coef == 0) |
238 | continue; |
239 | comb->elts[j].coef = comb->elts[i].coef; |
240 | comb->elts[j].val = fold_convert (type, comb->elts[i].val); |
241 | j++; |
242 | } |
243 | |
244 | comb->n = j; |
245 | if (comb->n < MAX_AFF_ELTS && comb->rest) |
246 | { |
247 | comb->elts[comb->n].coef = 1; |
248 | comb->elts[comb->n].val = comb->rest; |
249 | comb->rest = NULL_TREE; |
250 | comb->n++; |
251 | } |
252 | } |
253 | |
254 | /* Splits EXPR into an affine combination of parts. */ |
255 | |
256 | void |
257 | tree_to_aff_combination (tree expr, tree type, aff_tree *comb) |
258 | { |
259 | aff_tree tmp; |
260 | enum tree_code code; |
261 | tree cst, core, toffset; |
262 | HOST_WIDE_INT bitpos, bitsize; |
263 | machine_mode mode; |
264 | int unsignedp, reversep, volatilep; |
265 | |
266 | STRIP_NOPS (expr); |
267 | |
268 | code = TREE_CODE (expr); |
269 | switch (code) |
270 | { |
271 | case INTEGER_CST: |
272 | aff_combination_const (comb, type, wi::to_widest (expr)); |
273 | return; |
274 | |
275 | case POINTER_PLUS_EXPR: |
276 | tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb); |
277 | tree_to_aff_combination (TREE_OPERAND (expr, 1), sizetype, &tmp); |
278 | aff_combination_add (comb, &tmp); |
279 | return; |
280 | |
281 | case PLUS_EXPR: |
282 | case MINUS_EXPR: |
283 | tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb); |
284 | tree_to_aff_combination (TREE_OPERAND (expr, 1), type, &tmp); |
285 | if (code == MINUS_EXPR) |
286 | aff_combination_scale (&tmp, -1); |
287 | aff_combination_add (comb, &tmp); |
288 | return; |
289 | |
290 | case MULT_EXPR: |
291 | cst = TREE_OPERAND (expr, 1); |
292 | if (TREE_CODE (cst) != INTEGER_CST) |
293 | break; |
294 | tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb); |
295 | aff_combination_scale (comb, wi::to_widest (cst)); |
296 | return; |
297 | |
298 | case NEGATE_EXPR: |
299 | tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb); |
300 | aff_combination_scale (comb, -1); |
301 | return; |
302 | |
303 | case BIT_NOT_EXPR: |
304 | /* ~x = -x - 1 */ |
305 | tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb); |
306 | aff_combination_scale (comb, -1); |
307 | aff_combination_add_cst (comb, -1); |
308 | return; |
309 | |
310 | case ADDR_EXPR: |
311 | /* Handle &MEM[ptr + CST] which is equivalent to POINTER_PLUS_EXPR. */ |
312 | if (TREE_CODE (TREE_OPERAND (expr, 0)) == MEM_REF) |
313 | { |
314 | expr = TREE_OPERAND (expr, 0); |
315 | tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb); |
316 | tree_to_aff_combination (TREE_OPERAND (expr, 1), sizetype, &tmp); |
317 | aff_combination_add (comb, &tmp); |
318 | return; |
319 | } |
320 | core = get_inner_reference (TREE_OPERAND (expr, 0), &bitsize, &bitpos, |
321 | &toffset, &mode, &unsignedp, &reversep, |
322 | &volatilep); |
323 | if (bitpos % BITS_PER_UNIT != 0) |
324 | break; |
325 | aff_combination_const (comb, type, bitpos / BITS_PER_UNIT); |
326 | if (TREE_CODE (core) == MEM_REF) |
327 | { |
328 | aff_combination_add_cst (comb, wi::to_widest (TREE_OPERAND (core, 1))); |
329 | core = TREE_OPERAND (core, 0); |
330 | } |
331 | else |
332 | core = build_fold_addr_expr (core); |
333 | |
334 | if (TREE_CODE (core) == ADDR_EXPR) |
335 | aff_combination_add_elt (comb, core, 1); |
336 | else |
337 | { |
338 | tree_to_aff_combination (core, type, &tmp); |
339 | aff_combination_add (comb, &tmp); |
340 | } |
341 | if (toffset) |
342 | { |
343 | tree_to_aff_combination (toffset, type, &tmp); |
344 | aff_combination_add (comb, &tmp); |
345 | } |
346 | return; |
347 | |
348 | case MEM_REF: |
349 | if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR) |
350 | tree_to_aff_combination (TREE_OPERAND (TREE_OPERAND (expr, 0), 0), |
351 | type, comb); |
352 | else if (integer_zerop (TREE_OPERAND (expr, 1))) |
353 | { |
354 | aff_combination_elt (comb, type, expr); |
355 | return; |
356 | } |
357 | else |
358 | aff_combination_elt (comb, type, |
359 | build2 (MEM_REF, TREE_TYPE (expr), |
360 | TREE_OPERAND (expr, 0), |
361 | build_int_cst |
362 | (TREE_TYPE (TREE_OPERAND (expr, 1)), 0))); |
363 | tree_to_aff_combination (TREE_OPERAND (expr, 1), sizetype, &tmp); |
364 | aff_combination_add (comb, &tmp); |
365 | return; |
366 | |
367 | CASE_CONVERT: |
368 | { |
369 | tree otype = TREE_TYPE (expr); |
370 | tree inner = TREE_OPERAND (expr, 0); |
371 | tree itype = TREE_TYPE (inner); |
372 | enum tree_code icode = TREE_CODE (inner); |
373 | |
374 | /* In principle this is a valid folding, but it isn't necessarily |
375 | an optimization, so do it here and not in fold_unary. */ |
376 | if ((icode == PLUS_EXPR || icode == MINUS_EXPR || icode == MULT_EXPR) |
377 | && TREE_CODE (itype) == INTEGER_TYPE |
378 | && TREE_CODE (otype) == INTEGER_TYPE |
379 | && TYPE_PRECISION (otype) > TYPE_PRECISION (itype)) |
380 | { |
381 | tree op0 = TREE_OPERAND (inner, 0), op1 = TREE_OPERAND (inner, 1); |
382 | |
383 | /* If inner type has undefined overflow behavior, fold conversion |
384 | for below two cases: |
385 | (T1)(X *+- CST) -> (T1)X *+- (T1)CST |
386 | (T1)(X + X) -> (T1)X + (T1)X. */ |
387 | if (TYPE_OVERFLOW_UNDEFINED (itype) |
388 | && (TREE_CODE (op1) == INTEGER_CST |
389 | || (icode == PLUS_EXPR && operand_equal_p (op0, op1, 0)))) |
390 | { |
391 | op0 = fold_convert (otype, op0); |
392 | op1 = fold_convert (otype, op1); |
393 | expr = fold_build2 (icode, otype, op0, op1); |
394 | tree_to_aff_combination (expr, type, comb); |
395 | return; |
396 | } |
397 | wide_int minv, maxv; |
398 | /* If inner type has wrapping overflow behavior, fold conversion |
399 | for below case: |
400 | (T1)(X - CST) -> (T1)X - (T1)CST |
401 | if X - CST doesn't overflow by range information. Also handle |
402 | (T1)(X + CST) as (T1)(X - (-CST)). */ |
403 | if (TYPE_UNSIGNED (itype) |
404 | && TYPE_OVERFLOW_WRAPS (itype) |
405 | && TREE_CODE (op0) == SSA_NAME |
406 | && TREE_CODE (op1) == INTEGER_CST |
407 | && icode != MULT_EXPR |
408 | && get_range_info (op0, &minv, &maxv) == VR_RANGE) |
409 | { |
410 | if (icode == PLUS_EXPR) |
411 | op1 = wide_int_to_tree (itype, -wi::to_wide (op1)); |
412 | if (wi::geu_p (minv, wi::to_wide (op1))) |
413 | { |
414 | op0 = fold_convert (otype, op0); |
415 | op1 = fold_convert (otype, op1); |
416 | expr = fold_build2 (MINUS_EXPR, otype, op0, op1); |
417 | tree_to_aff_combination (expr, type, comb); |
418 | return; |
419 | } |
420 | } |
421 | } |
422 | } |
423 | break; |
424 | |
425 | default: |
426 | break; |
427 | } |
428 | |
429 | aff_combination_elt (comb, type, expr); |
430 | } |
431 | |
432 | /* Creates EXPR + ELT * SCALE in TYPE. EXPR is taken from affine |
433 | combination COMB. */ |
434 | |
435 | static tree |
436 | add_elt_to_tree (tree expr, tree type, tree elt, const widest_int &scale_in) |
437 | { |
438 | enum tree_code code; |
439 | |
440 | widest_int scale = wide_int_ext_for_comb (scale_in, type); |
441 | |
442 | elt = fold_convert (type, elt); |
443 | if (scale == 1) |
444 | { |
445 | if (!expr) |
446 | return elt; |
447 | |
448 | return fold_build2 (PLUS_EXPR, type, expr, elt); |
449 | } |
450 | |
451 | if (scale == -1) |
452 | { |
453 | if (!expr) |
454 | return fold_build1 (NEGATE_EXPR, type, elt); |
455 | |
456 | return fold_build2 (MINUS_EXPR, type, expr, elt); |
457 | } |
458 | |
459 | if (!expr) |
460 | return fold_build2 (MULT_EXPR, type, elt, wide_int_to_tree (type, scale)); |
461 | |
462 | if (wi::neg_p (scale)) |
463 | { |
464 | code = MINUS_EXPR; |
465 | scale = -scale; |
466 | } |
467 | else |
468 | code = PLUS_EXPR; |
469 | |
470 | elt = fold_build2 (MULT_EXPR, type, elt, wide_int_to_tree (type, scale)); |
471 | return fold_build2 (code, type, expr, elt); |
472 | } |
473 | |
474 | /* Makes tree from the affine combination COMB. */ |
475 | |
476 | tree |
477 | aff_combination_to_tree (aff_tree *comb) |
478 | { |
479 | tree type = comb->type, base = NULL_TREE, expr = NULL_TREE; |
480 | unsigned i; |
481 | widest_int off, sgn; |
482 | |
483 | gcc_assert (comb->n == MAX_AFF_ELTS || comb->rest == NULL_TREE); |
484 | |
485 | i = 0; |
486 | if (POINTER_TYPE_P (type)) |
487 | { |
488 | type = sizetype; |
489 | if (comb->n > 0 && comb->elts[0].coef == 1 |
490 | && POINTER_TYPE_P (TREE_TYPE (comb->elts[0].val))) |
491 | { |
492 | base = comb->elts[0].val; |
493 | ++i; |
494 | } |
495 | } |
496 | |
497 | for (; i < comb->n; i++) |
498 | expr = add_elt_to_tree (expr, type, comb->elts[i].val, comb->elts[i].coef); |
499 | |
500 | if (comb->rest) |
501 | expr = add_elt_to_tree (expr, type, comb->rest, 1); |
502 | |
503 | /* Ensure that we get x - 1, not x + (-1) or x + 0xff..f if x is |
504 | unsigned. */ |
505 | if (wi::neg_p (comb->offset)) |
506 | { |
507 | off = -comb->offset; |
508 | sgn = -1; |
509 | } |
510 | else |
511 | { |
512 | off = comb->offset; |
513 | sgn = 1; |
514 | } |
515 | expr = add_elt_to_tree (expr, type, wide_int_to_tree (type, off), sgn); |
516 | |
517 | if (base) |
518 | return fold_build_pointer_plus (base, expr); |
519 | else |
520 | return fold_convert (comb->type, expr); |
521 | } |
522 | |
523 | /* Copies the tree elements of COMB to ensure that they are not shared. */ |
524 | |
525 | void |
526 | unshare_aff_combination (aff_tree *comb) |
527 | { |
528 | unsigned i; |
529 | |
530 | for (i = 0; i < comb->n; i++) |
531 | comb->elts[i].val = unshare_expr (comb->elts[i].val); |
532 | if (comb->rest) |
533 | comb->rest = unshare_expr (comb->rest); |
534 | } |
535 | |
536 | /* Remove M-th element from COMB. */ |
537 | |
538 | void |
539 | aff_combination_remove_elt (aff_tree *comb, unsigned m) |
540 | { |
541 | comb->n--; |
542 | if (m <= comb->n) |
543 | comb->elts[m] = comb->elts[comb->n]; |
544 | if (comb->rest) |
545 | { |
546 | comb->elts[comb->n].coef = 1; |
547 | comb->elts[comb->n].val = comb->rest; |
548 | comb->rest = NULL_TREE; |
549 | comb->n++; |
550 | } |
551 | } |
552 | |
553 | /* Adds C * COEF * VAL to R. VAL may be NULL, in that case only |
554 | C * COEF is added to R. */ |
555 | |
556 | |
557 | static void |
558 | aff_combination_add_product (aff_tree *c, const widest_int &coef, tree val, |
559 | aff_tree *r) |
560 | { |
561 | unsigned i; |
562 | tree aval, type; |
563 | |
564 | for (i = 0; i < c->n; i++) |
565 | { |
566 | aval = c->elts[i].val; |
567 | if (val) |
568 | { |
569 | type = TREE_TYPE (aval); |
570 | aval = fold_build2 (MULT_EXPR, type, aval, |
571 | fold_convert (type, val)); |
572 | } |
573 | |
574 | aff_combination_add_elt (r, aval, coef * c->elts[i].coef); |
575 | } |
576 | |
577 | if (c->rest) |
578 | { |
579 | aval = c->rest; |
580 | if (val) |
581 | { |
582 | type = TREE_TYPE (aval); |
583 | aval = fold_build2 (MULT_EXPR, type, aval, |
584 | fold_convert (type, val)); |
585 | } |
586 | |
587 | aff_combination_add_elt (r, aval, coef); |
588 | } |
589 | |
590 | if (val) |
591 | aff_combination_add_elt (r, val, coef * c->offset); |
592 | else |
593 | aff_combination_add_cst (r, coef * c->offset); |
594 | } |
595 | |
596 | /* Multiplies C1 by C2, storing the result to R */ |
597 | |
598 | void |
599 | aff_combination_mult (aff_tree *c1, aff_tree *c2, aff_tree *r) |
600 | { |
601 | unsigned i; |
602 | gcc_assert (TYPE_PRECISION (c1->type) == TYPE_PRECISION (c2->type)); |
603 | |
604 | aff_combination_zero (r, c1->type); |
605 | |
606 | for (i = 0; i < c2->n; i++) |
607 | aff_combination_add_product (c1, c2->elts[i].coef, c2->elts[i].val, r); |
608 | if (c2->rest) |
609 | aff_combination_add_product (c1, 1, c2->rest, r); |
610 | aff_combination_add_product (c1, c2->offset, NULL, r); |
611 | } |
612 | |
613 | /* Returns the element of COMB whose value is VAL, or NULL if no such |
614 | element exists. If IDX is not NULL, it is set to the index of VAL in |
615 | COMB. */ |
616 | |
617 | static struct aff_comb_elt * |
618 | aff_combination_find_elt (aff_tree *comb, tree val, unsigned *idx) |
619 | { |
620 | unsigned i; |
621 | |
622 | for (i = 0; i < comb->n; i++) |
623 | if (operand_equal_p (comb->elts[i].val, val, 0)) |
624 | { |
625 | if (idx) |
626 | *idx = i; |
627 | |
628 | return &comb->elts[i]; |
629 | } |
630 | |
631 | return NULL; |
632 | } |
633 | |
634 | /* Element of the cache that maps ssa name NAME to its expanded form |
635 | as an affine expression EXPANSION. */ |
636 | |
637 | struct name_expansion |
638 | { |
639 | aff_tree expansion; |
640 | |
641 | /* True if the expansion for the name is just being generated. */ |
642 | unsigned in_progress : 1; |
643 | }; |
644 | |
645 | /* Expands SSA names in COMB recursively. CACHE is used to cache the |
646 | results. */ |
647 | |
648 | void |
649 | aff_combination_expand (aff_tree *comb ATTRIBUTE_UNUSED, |
650 | hash_map<tree, name_expansion *> **cache) |
651 | { |
652 | unsigned i; |
653 | aff_tree to_add, current, curre; |
654 | tree e, rhs; |
655 | gimple *def; |
656 | widest_int scale; |
657 | struct name_expansion *exp; |
658 | |
659 | aff_combination_zero (&to_add, comb->type); |
660 | for (i = 0; i < comb->n; i++) |
661 | { |
662 | tree type, name; |
663 | enum tree_code code; |
664 | |
665 | e = comb->elts[i].val; |
666 | type = TREE_TYPE (e); |
667 | name = e; |
668 | /* Look through some conversions. */ |
669 | if (CONVERT_EXPR_P (e) |
670 | && (TYPE_PRECISION (type) |
671 | >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (e, 0))))) |
672 | name = TREE_OPERAND (e, 0); |
673 | if (TREE_CODE (name) != SSA_NAME) |
674 | continue; |
675 | def = SSA_NAME_DEF_STMT (name); |
676 | if (!is_gimple_assign (def) || gimple_assign_lhs (def) != name) |
677 | continue; |
678 | |
679 | code = gimple_assign_rhs_code (def); |
680 | if (code != SSA_NAME |
681 | && !IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)) |
682 | && (get_gimple_rhs_class (code) != GIMPLE_SINGLE_RHS |
683 | || !is_gimple_min_invariant (gimple_assign_rhs1 (def)))) |
684 | continue; |
685 | |
686 | /* We do not know whether the reference retains its value at the |
687 | place where the expansion is used. */ |
688 | if (TREE_CODE_CLASS (code) == tcc_reference) |
689 | continue; |
690 | |
691 | if (!*cache) |
692 | *cache = new hash_map<tree, name_expansion *>; |
693 | name_expansion **slot = &(*cache)->get_or_insert (e); |
694 | exp = *slot; |
695 | |
696 | if (!exp) |
697 | { |
698 | exp = XNEW (struct name_expansion); |
699 | exp->in_progress = 1; |
700 | *slot = exp; |
701 | rhs = gimple_assign_rhs_to_tree (def); |
702 | if (e != name) |
703 | rhs = fold_convert (type, rhs); |
704 | |
705 | tree_to_aff_combination_expand (rhs, comb->type, ¤t, cache); |
706 | exp->expansion = current; |
707 | exp->in_progress = 0; |
708 | } |
709 | else |
710 | { |
711 | /* Since we follow the definitions in the SSA form, we should not |
712 | enter a cycle unless we pass through a phi node. */ |
713 | gcc_assert (!exp->in_progress); |
714 | current = exp->expansion; |
715 | } |
716 | |
717 | /* Accumulate the new terms to TO_ADD, so that we do not modify |
718 | COMB while traversing it; include the term -coef * E, to remove |
719 | it from COMB. */ |
720 | scale = comb->elts[i].coef; |
721 | aff_combination_zero (&curre, comb->type); |
722 | aff_combination_add_elt (&curre, e, -scale); |
723 | aff_combination_scale (¤t, scale); |
724 | aff_combination_add (&to_add, ¤t); |
725 | aff_combination_add (&to_add, &curre); |
726 | } |
727 | aff_combination_add (comb, &to_add); |
728 | } |
729 | |
730 | /* Similar to tree_to_aff_combination, but follows SSA name definitions |
731 | and expands them recursively. CACHE is used to cache the expansions |
732 | of the ssa names, to avoid exponential time complexity for cases |
733 | like |
734 | |
735 | a1 = a0 + a0; |
736 | a2 = a1 + a1; |
737 | a3 = a2 + a2; |
738 | ... */ |
739 | |
740 | void |
741 | tree_to_aff_combination_expand (tree expr, tree type, aff_tree *comb, |
742 | hash_map<tree, name_expansion *> **cache) |
743 | { |
744 | tree_to_aff_combination (expr, type, comb); |
745 | aff_combination_expand (comb, cache); |
746 | } |
747 | |
748 | /* Frees memory occupied by struct name_expansion in *VALUE. Callback for |
749 | hash_map::traverse. */ |
750 | |
751 | bool |
752 | free_name_expansion (tree const &, name_expansion **value, void *) |
753 | { |
754 | free (*value); |
755 | return true; |
756 | } |
757 | |
758 | /* Frees memory allocated for the CACHE used by |
759 | tree_to_aff_combination_expand. */ |
760 | |
761 | void |
762 | free_affine_expand_cache (hash_map<tree, name_expansion *> **cache) |
763 | { |
764 | if (!*cache) |
765 | return; |
766 | |
767 | (*cache)->traverse<void *, free_name_expansion> (NULL); |
768 | delete (*cache); |
769 | *cache = NULL; |
770 | } |
771 | |
772 | /* If VAL != CST * DIV for any constant CST, returns false. |
773 | Otherwise, if *MULT_SET is true, additionally compares CST and MULT, |
774 | and if they are different, returns false. Finally, if neither of these |
775 | two cases occur, true is returned, and CST is stored to MULT and MULT_SET |
776 | is set to true. */ |
777 | |
778 | static bool |
779 | wide_int_constant_multiple_p (const widest_int &val, const widest_int &div, |
780 | bool *mult_set, widest_int *mult) |
781 | { |
782 | widest_int rem, cst; |
783 | |
784 | if (val == 0) |
785 | { |
786 | if (*mult_set && *mult != 0) |
787 | return false; |
788 | *mult_set = true; |
789 | *mult = 0; |
790 | return true; |
791 | } |
792 | |
793 | if (div == 0) |
794 | return false; |
795 | |
796 | if (!wi::multiple_of_p (val, div, SIGNED, &cst)) |
797 | return false; |
798 | |
799 | if (*mult_set && *mult != cst) |
800 | return false; |
801 | |
802 | *mult_set = true; |
803 | *mult = cst; |
804 | return true; |
805 | } |
806 | |
807 | /* Returns true if VAL = X * DIV for some constant X. If this is the case, |
808 | X is stored to MULT. */ |
809 | |
810 | bool |
811 | aff_combination_constant_multiple_p (aff_tree *val, aff_tree *div, |
812 | widest_int *mult) |
813 | { |
814 | bool mult_set = false; |
815 | unsigned i; |
816 | |
817 | if (val->n == 0 && val->offset == 0) |
818 | { |
819 | *mult = 0; |
820 | return true; |
821 | } |
822 | if (val->n != div->n) |
823 | return false; |
824 | |
825 | if (val->rest || div->rest) |
826 | return false; |
827 | |
828 | if (!wide_int_constant_multiple_p (val->offset, div->offset, |
829 | &mult_set, mult)) |
830 | return false; |
831 | |
832 | for (i = 0; i < div->n; i++) |
833 | { |
834 | struct aff_comb_elt *elt |
835 | = aff_combination_find_elt (val, div->elts[i].val, NULL); |
836 | if (!elt) |
837 | return false; |
838 | if (!wide_int_constant_multiple_p (elt->coef, div->elts[i].coef, |
839 | &mult_set, mult)) |
840 | return false; |
841 | } |
842 | |
843 | gcc_assert (mult_set); |
844 | return true; |
845 | } |
846 | |
847 | /* Prints the affine VAL to the FILE. */ |
848 | |
849 | static void |
850 | print_aff (FILE *file, aff_tree *val) |
851 | { |
852 | unsigned i; |
853 | signop sgn = TYPE_SIGN (val->type); |
854 | if (POINTER_TYPE_P (val->type)) |
855 | sgn = SIGNED; |
856 | fprintf (file, "{\n type = " ); |
857 | print_generic_expr (file, val->type, TDF_VOPS|TDF_MEMSYMS); |
858 | fprintf (file, "\n offset = " ); |
859 | print_dec (val->offset, file, sgn); |
860 | if (val->n > 0) |
861 | { |
862 | fprintf (file, "\n elements = {\n" ); |
863 | for (i = 0; i < val->n; i++) |
864 | { |
865 | fprintf (file, " [%d] = " , i); |
866 | print_generic_expr (file, val->elts[i].val, TDF_VOPS|TDF_MEMSYMS); |
867 | |
868 | fprintf (file, " * " ); |
869 | print_dec (val->elts[i].coef, file, sgn); |
870 | if (i != val->n - 1) |
871 | fprintf (file, ", \n" ); |
872 | } |
873 | fprintf (file, "\n }" ); |
874 | } |
875 | if (val->rest) |
876 | { |
877 | fprintf (file, "\n rest = " ); |
878 | print_generic_expr (file, val->rest, TDF_VOPS|TDF_MEMSYMS); |
879 | } |
880 | fprintf (file, "\n}" ); |
881 | } |
882 | |
883 | /* Prints the affine VAL to the standard error, used for debugging. */ |
884 | |
885 | DEBUG_FUNCTION void |
886 | debug_aff (aff_tree *val) |
887 | { |
888 | print_aff (stderr, val); |
889 | fprintf (stderr, "\n" ); |
890 | } |
891 | |
892 | /* Computes address of the reference REF in ADDR. The size of the accessed |
893 | location is stored to SIZE. Returns the ultimate containing object to |
894 | which REF refers. */ |
895 | |
896 | tree |
897 | get_inner_reference_aff (tree ref, aff_tree *addr, widest_int *size) |
898 | { |
899 | HOST_WIDE_INT bitsize, bitpos; |
900 | tree toff; |
901 | machine_mode mode; |
902 | int uns, rev, vol; |
903 | aff_tree tmp; |
904 | tree base = get_inner_reference (ref, &bitsize, &bitpos, &toff, &mode, |
905 | &uns, &rev, &vol); |
906 | tree base_addr = build_fold_addr_expr (base); |
907 | |
908 | /* ADDR = &BASE + TOFF + BITPOS / BITS_PER_UNIT. */ |
909 | |
910 | tree_to_aff_combination (base_addr, sizetype, addr); |
911 | |
912 | if (toff) |
913 | { |
914 | tree_to_aff_combination (toff, sizetype, &tmp); |
915 | aff_combination_add (addr, &tmp); |
916 | } |
917 | |
918 | aff_combination_const (&tmp, sizetype, bitpos / BITS_PER_UNIT); |
919 | aff_combination_add (addr, &tmp); |
920 | |
921 | *size = (bitsize + BITS_PER_UNIT - 1) / BITS_PER_UNIT; |
922 | |
923 | return base; |
924 | } |
925 | |
926 | /* Returns true if a region of size SIZE1 at position 0 and a region of |
927 | size SIZE2 at position DIFF cannot overlap. */ |
928 | |
929 | bool |
930 | aff_comb_cannot_overlap_p (aff_tree *diff, const widest_int &size1, |
931 | const widest_int &size2) |
932 | { |
933 | /* Unless the difference is a constant, we fail. */ |
934 | if (diff->n != 0) |
935 | return false; |
936 | |
937 | if (wi::neg_p (diff->offset)) |
938 | { |
939 | /* The second object is before the first one, we succeed if the last |
940 | element of the second object is before the start of the first one. */ |
941 | return wi::neg_p (diff->offset + size2 - 1); |
942 | } |
943 | else |
944 | { |
945 | /* We succeed if the second object starts after the first one ends. */ |
946 | return size1 <= diff->offset; |
947 | } |
948 | } |
949 | |
950 | |