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8b11a64c | 1 | /* Induction variable optimizations. |
6615c446 | 2 | Copyright (C) 2003, 2004 Free Software Foundation, Inc. |
8b11a64c ZD |
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 2, 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 COPYING. If not, write to the Free | |
18 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
19 | 02111-1307, USA. */ | |
20 | ||
21 | /* This pass tries to find the optimal set of induction variables for the loop. | |
22 | It optimizes just the basic linear induction variables (although adding | |
23 | support for other types should not be too hard). It includes the | |
24 | optimizations commonly known as strength reduction, induction variable | |
25 | coalescing and induction variable elimination. It does it in the | |
26 | following steps: | |
27 | ||
28 | 1) The interesting uses of induction variables are found. This includes | |
29 | ||
30 | -- uses of induction variables in non-linear expressions | |
31 | -- addresses of arrays | |
32 | -- comparisons of induction variables | |
33 | ||
34 | 2) Candidates for the induction variables are found. This includes | |
35 | ||
36 | -- old induction variables | |
37 | -- the variables defined by expressions derived from the "interesting | |
38 | uses" above | |
39 | ||
40 | 3) The optimal (w.r. to a cost function) set of variables is chosen. The | |
41 | cost function assigns a cost to sets of induction variables and consists | |
42 | of three parts: | |
43 | ||
44 | -- The use costs. Each of the interesting uses chooses the best induction | |
45 | variable in the set and adds its cost to the sum. The cost reflects | |
46 | the time spent on modifying the induction variables value to be usable | |
47 | for the given purpose (adding base and offset for arrays, etc.). | |
48 | -- The variable costs. Each of the variables has a cost assigned that | |
49 | reflects the costs associated with incrementing the value of the | |
50 | variable. The original variables are somewhat preferred. | |
51 | -- The set cost. Depending on the size of the set, extra cost may be | |
52 | added to reflect register pressure. | |
53 | ||
54 | All the costs are defined in a machine-specific way, using the target | |
55 | hooks and machine descriptions to determine them. | |
56 | ||
57 | 4) The trees are transformed to use the new variables, the dead code is | |
58 | removed. | |
59 | ||
60 | All of this is done loop by loop. Doing it globally is theoretically | |
61 | possible, it might give a better performance and it might enable us | |
62 | to decide costs more precisely, but getting all the interactions right | |
63 | would be complicated. */ | |
64 | ||
65 | #include "config.h" | |
66 | #include "system.h" | |
67 | #include "coretypes.h" | |
68 | #include "tm.h" | |
69 | #include "tree.h" | |
70 | #include "rtl.h" | |
71 | #include "tm_p.h" | |
72 | #include "hard-reg-set.h" | |
73 | #include "basic-block.h" | |
74 | #include "output.h" | |
75 | #include "diagnostic.h" | |
76 | #include "tree-flow.h" | |
77 | #include "tree-dump.h" | |
78 | #include "timevar.h" | |
79 | #include "cfgloop.h" | |
80 | #include "varray.h" | |
81 | #include "expr.h" | |
82 | #include "tree-pass.h" | |
83 | #include "ggc.h" | |
84 | #include "insn-config.h" | |
85 | #include "recog.h" | |
86 | #include "hashtab.h" | |
87 | #include "tree-chrec.h" | |
88 | #include "tree-scalar-evolution.h" | |
89 | #include "cfgloop.h" | |
90 | #include "params.h" | |
91 | ||
92 | /* The infinite cost. */ | |
93 | #define INFTY 10000000 | |
94 | ||
95 | /* The expected number of loop iterations. TODO -- use profiling instead of | |
96 | this. */ | |
97 | #define AVG_LOOP_NITER(LOOP) 5 | |
98 | ||
99 | /* Just to shorten the ugly names. */ | |
100 | #define EXEC_BINARY nondestructive_fold_binary_to_constant | |
101 | #define EXEC_UNARY nondestructive_fold_unary_to_constant | |
102 | ||
103 | /* Representation of the induction variable. */ | |
104 | struct iv | |
105 | { | |
106 | tree base; /* Initial value of the iv. */ | |
107 | tree step; /* Step of the iv (constant only). */ | |
108 | tree ssa_name; /* The ssa name with the value. */ | |
109 | bool biv_p; /* Is it a biv? */ | |
110 | bool have_use_for; /* Do we already have a use for it? */ | |
111 | unsigned use_id; /* The identifier in the use if it is the case. */ | |
112 | }; | |
113 | ||
114 | /* Per-ssa version information (induction variable descriptions, etc.). */ | |
115 | struct version_info | |
116 | { | |
117 | tree name; /* The ssa name. */ | |
118 | struct iv *iv; /* Induction variable description. */ | |
119 | bool has_nonlin_use; /* For a loop-level invariant, whether it is used in | |
120 | an expression that is not an induction variable. */ | |
121 | unsigned inv_id; /* Id of an invariant. */ | |
122 | bool preserve_biv; /* For the original biv, whether to preserve it. */ | |
123 | }; | |
124 | ||
125 | /* Information attached to loop. */ | |
126 | struct loop_data | |
127 | { | |
128 | struct tree_niter_desc niter; | |
129 | /* Number of iterations. */ | |
130 | ||
131 | unsigned regs_used; /* Number of registers used. */ | |
132 | }; | |
133 | ||
134 | /* Types of uses. */ | |
135 | enum use_type | |
136 | { | |
137 | USE_NONLINEAR_EXPR, /* Use in a nonlinear expression. */ | |
138 | USE_OUTER, /* The induction variable is used outside the loop. */ | |
139 | USE_ADDRESS, /* Use in an address. */ | |
140 | USE_COMPARE /* Use is a compare. */ | |
141 | }; | |
142 | ||
143 | /* The candidate - cost pair. */ | |
144 | struct cost_pair | |
145 | { | |
146 | struct iv_cand *cand; /* The candidate. */ | |
147 | unsigned cost; /* The cost. */ | |
148 | bitmap depends_on; /* The list of invariants that have to be | |
149 | preserved. */ | |
150 | }; | |
151 | ||
152 | /* Use. */ | |
153 | struct iv_use | |
154 | { | |
155 | unsigned id; /* The id of the use. */ | |
156 | enum use_type type; /* Type of the use. */ | |
157 | struct iv *iv; /* The induction variable it is based on. */ | |
158 | tree stmt; /* Statement in that it occurs. */ | |
159 | tree *op_p; /* The place where it occurs. */ | |
160 | bitmap related_cands; /* The set of "related" iv candidates. */ | |
161 | ||
162 | unsigned n_map_members; /* Number of candidates in the cost_map list. */ | |
163 | struct cost_pair *cost_map; | |
164 | /* The costs wrto the iv candidates. */ | |
165 | ||
166 | struct iv_cand *selected; | |
167 | /* The selected candidate. */ | |
168 | }; | |
169 | ||
170 | /* The position where the iv is computed. */ | |
171 | enum iv_position | |
172 | { | |
173 | IP_NORMAL, /* At the end, just before the exit condition. */ | |
174 | IP_END, /* At the end of the latch block. */ | |
175 | IP_ORIGINAL /* The original biv. */ | |
176 | }; | |
177 | ||
178 | /* The induction variable candidate. */ | |
179 | struct iv_cand | |
180 | { | |
181 | unsigned id; /* The number of the candidate. */ | |
182 | bool important; /* Whether this is an "important" candidate, i.e. such | |
183 | that it should be considered by all uses. */ | |
184 | enum iv_position pos; /* Where it is computed. */ | |
185 | tree incremented_at; /* For original biv, the statement where it is | |
186 | incremented. */ | |
187 | tree var_before; /* The variable used for it before increment. */ | |
188 | tree var_after; /* The variable used for it after increment. */ | |
189 | struct iv *iv; /* The value of the candidate. NULL for | |
190 | "pseudocandidate" used to indicate the possibility | |
191 | to replace the final value of an iv by direct | |
192 | computation of the value. */ | |
193 | unsigned cost; /* Cost of the candidate. */ | |
194 | }; | |
195 | ||
196 | /* The data used by the induction variable optimizations. */ | |
197 | ||
198 | struct ivopts_data | |
199 | { | |
200 | /* The currently optimized loop. */ | |
201 | struct loop *current_loop; | |
202 | ||
203 | /* The size of version_info array allocated. */ | |
204 | unsigned version_info_size; | |
205 | ||
206 | /* The array of information for the ssa names. */ | |
207 | struct version_info *version_info; | |
208 | ||
209 | /* The bitmap of indices in version_info whose value was changed. */ | |
210 | bitmap relevant; | |
211 | ||
212 | /* The maximum invariant id. */ | |
213 | unsigned max_inv_id; | |
214 | ||
215 | /* The uses of induction variables. */ | |
216 | varray_type iv_uses; | |
217 | ||
218 | /* The candidates. */ | |
219 | varray_type iv_candidates; | |
220 | ||
221 | /* Whether to consider just related and important candidates when replacing a | |
222 | use. */ | |
223 | bool consider_all_candidates; | |
224 | }; | |
225 | ||
226 | /* Bound on number of candidates below that all candidates are considered. */ | |
227 | ||
228 | #define CONSIDER_ALL_CANDIDATES_BOUND \ | |
229 | ((unsigned) PARAM_VALUE (PARAM_IV_CONSIDER_ALL_CANDIDATES_BOUND)) | |
230 | ||
2a7e31df | 231 | /* If there are more iv occurrences, we just give up (it is quite unlikely that |
8b11a64c ZD |
232 | optimizing such a loop would help, and it would take ages). */ |
233 | ||
234 | #define MAX_CONSIDERED_USES \ | |
235 | ((unsigned) PARAM_VALUE (PARAM_IV_MAX_CONSIDERED_USES)) | |
236 | ||
237 | /* The list of trees for that the decl_rtl field must be reset is stored | |
238 | here. */ | |
239 | ||
240 | static varray_type decl_rtl_to_reset; | |
241 | ||
242 | /* Number of uses recorded in DATA. */ | |
243 | ||
244 | static inline unsigned | |
245 | n_iv_uses (struct ivopts_data *data) | |
246 | { | |
247 | return VARRAY_ACTIVE_SIZE (data->iv_uses); | |
248 | } | |
249 | ||
250 | /* Ith use recorded in DATA. */ | |
251 | ||
252 | static inline struct iv_use * | |
253 | iv_use (struct ivopts_data *data, unsigned i) | |
254 | { | |
255 | return VARRAY_GENERIC_PTR_NOGC (data->iv_uses, i); | |
256 | } | |
257 | ||
258 | /* Number of candidates recorded in DATA. */ | |
259 | ||
260 | static inline unsigned | |
261 | n_iv_cands (struct ivopts_data *data) | |
262 | { | |
263 | return VARRAY_ACTIVE_SIZE (data->iv_candidates); | |
264 | } | |
265 | ||
266 | /* Ith candidate recorded in DATA. */ | |
267 | ||
268 | static inline struct iv_cand * | |
269 | iv_cand (struct ivopts_data *data, unsigned i) | |
270 | { | |
271 | return VARRAY_GENERIC_PTR_NOGC (data->iv_candidates, i); | |
272 | } | |
273 | ||
274 | /* The data for LOOP. */ | |
275 | ||
276 | static inline struct loop_data * | |
277 | loop_data (struct loop *loop) | |
278 | { | |
279 | return loop->aux; | |
280 | } | |
281 | ||
282 | /* The single loop exit if it dominates the latch, NULL otherwise. */ | |
283 | ||
284 | static edge | |
285 | single_dom_exit (struct loop *loop) | |
286 | { | |
287 | edge exit = loop->single_exit; | |
288 | ||
289 | if (!exit) | |
290 | return NULL; | |
291 | ||
292 | if (!just_once_each_iteration_p (loop, exit->src)) | |
293 | return NULL; | |
294 | ||
295 | return exit; | |
296 | } | |
297 | ||
298 | /* Dumps information about the induction variable IV to FILE. */ | |
299 | ||
300 | extern void dump_iv (FILE *, struct iv *); | |
301 | void | |
302 | dump_iv (FILE *file, struct iv *iv) | |
303 | { | |
304 | fprintf (file, "ssa name "); | |
305 | print_generic_expr (file, iv->ssa_name, TDF_SLIM); | |
306 | fprintf (file, "\n"); | |
307 | ||
2f4675b4 ZD |
308 | fprintf (file, " type "); |
309 | print_generic_expr (file, TREE_TYPE (iv->base), TDF_SLIM); | |
310 | fprintf (file, "\n"); | |
311 | ||
8b11a64c ZD |
312 | if (iv->step) |
313 | { | |
314 | fprintf (file, " base "); | |
315 | print_generic_expr (file, iv->base, TDF_SLIM); | |
316 | fprintf (file, "\n"); | |
317 | ||
318 | fprintf (file, " step "); | |
319 | print_generic_expr (file, iv->step, TDF_SLIM); | |
320 | fprintf (file, "\n"); | |
321 | } | |
322 | else | |
323 | { | |
324 | fprintf (file, " invariant "); | |
325 | print_generic_expr (file, iv->base, TDF_SLIM); | |
326 | fprintf (file, "\n"); | |
327 | } | |
328 | ||
329 | if (iv->biv_p) | |
330 | fprintf (file, " is a biv\n"); | |
331 | } | |
332 | ||
333 | /* Dumps information about the USE to FILE. */ | |
334 | ||
335 | extern void dump_use (FILE *, struct iv_use *); | |
336 | void | |
337 | dump_use (FILE *file, struct iv_use *use) | |
338 | { | |
339 | struct iv *iv = use->iv; | |
340 | ||
341 | fprintf (file, "use %d\n", use->id); | |
342 | ||
343 | switch (use->type) | |
344 | { | |
345 | case USE_NONLINEAR_EXPR: | |
346 | fprintf (file, " generic\n"); | |
347 | break; | |
348 | ||
349 | case USE_OUTER: | |
350 | fprintf (file, " outside\n"); | |
351 | break; | |
352 | ||
353 | case USE_ADDRESS: | |
354 | fprintf (file, " address\n"); | |
355 | break; | |
356 | ||
357 | case USE_COMPARE: | |
358 | fprintf (file, " compare\n"); | |
359 | break; | |
360 | ||
361 | default: | |
1e128c5f | 362 | gcc_unreachable (); |
8b11a64c ZD |
363 | } |
364 | ||
2f4675b4 ZD |
365 | fprintf (file, " in statement "); |
366 | print_generic_expr (file, use->stmt, TDF_SLIM); | |
367 | fprintf (file, "\n"); | |
368 | ||
369 | fprintf (file, " at position "); | |
370 | if (use->op_p) | |
371 | print_generic_expr (file, *use->op_p, TDF_SLIM); | |
372 | fprintf (file, "\n"); | |
373 | ||
374 | fprintf (file, " type "); | |
375 | print_generic_expr (file, TREE_TYPE (iv->base), TDF_SLIM); | |
376 | fprintf (file, "\n"); | |
377 | ||
378 | if (iv->step) | |
379 | { | |
380 | fprintf (file, " base "); | |
381 | print_generic_expr (file, iv->base, TDF_SLIM); | |
382 | fprintf (file, "\n"); | |
383 | ||
384 | fprintf (file, " step "); | |
385 | print_generic_expr (file, iv->step, TDF_SLIM); | |
386 | fprintf (file, "\n"); | |
387 | } | |
388 | else | |
389 | { | |
390 | fprintf (file, " invariant "); | |
391 | print_generic_expr (file, iv->base, TDF_SLIM); | |
392 | fprintf (file, "\n"); | |
393 | } | |
394 | ||
395 | fprintf (file, " related candidates "); | |
396 | dump_bitmap (file, use->related_cands); | |
8b11a64c ZD |
397 | } |
398 | ||
399 | /* Dumps information about the uses to FILE. */ | |
400 | ||
401 | extern void dump_uses (FILE *, struct ivopts_data *); | |
402 | void | |
403 | dump_uses (FILE *file, struct ivopts_data *data) | |
404 | { | |
405 | unsigned i; | |
406 | struct iv_use *use; | |
407 | ||
408 | for (i = 0; i < n_iv_uses (data); i++) | |
409 | { | |
410 | use = iv_use (data, i); | |
411 | ||
412 | dump_use (file, use); | |
413 | fprintf (file, "\n"); | |
414 | } | |
415 | } | |
416 | ||
417 | /* Dumps information about induction variable candidate CAND to FILE. */ | |
418 | ||
419 | extern void dump_cand (FILE *, struct iv_cand *); | |
420 | void | |
421 | dump_cand (FILE *file, struct iv_cand *cand) | |
422 | { | |
423 | struct iv *iv = cand->iv; | |
424 | ||
425 | fprintf (file, "candidate %d%s\n", | |
426 | cand->id, cand->important ? " (important)" : ""); | |
427 | ||
428 | if (!iv) | |
429 | { | |
430 | fprintf (file, " final value replacement\n"); | |
431 | return; | |
432 | } | |
433 | ||
434 | switch (cand->pos) | |
435 | { | |
436 | case IP_NORMAL: | |
437 | fprintf (file, " incremented before exit test\n"); | |
438 | break; | |
439 | ||
440 | case IP_END: | |
441 | fprintf (file, " incremented at end\n"); | |
442 | break; | |
443 | ||
444 | case IP_ORIGINAL: | |
445 | fprintf (file, " original biv\n"); | |
446 | break; | |
447 | } | |
448 | ||
2f4675b4 ZD |
449 | fprintf (file, " type "); |
450 | print_generic_expr (file, TREE_TYPE (iv->base), TDF_SLIM); | |
451 | fprintf (file, "\n"); | |
452 | ||
453 | if (iv->step) | |
454 | { | |
455 | fprintf (file, " base "); | |
456 | print_generic_expr (file, iv->base, TDF_SLIM); | |
457 | fprintf (file, "\n"); | |
458 | ||
459 | fprintf (file, " step "); | |
460 | print_generic_expr (file, iv->step, TDF_SLIM); | |
461 | fprintf (file, "\n"); | |
462 | } | |
463 | else | |
464 | { | |
465 | fprintf (file, " invariant "); | |
466 | print_generic_expr (file, iv->base, TDF_SLIM); | |
467 | fprintf (file, "\n"); | |
468 | } | |
8b11a64c ZD |
469 | } |
470 | ||
471 | /* Returns the info for ssa version VER. */ | |
472 | ||
473 | static inline struct version_info * | |
474 | ver_info (struct ivopts_data *data, unsigned ver) | |
475 | { | |
476 | return data->version_info + ver; | |
477 | } | |
478 | ||
479 | /* Returns the info for ssa name NAME. */ | |
480 | ||
481 | static inline struct version_info * | |
482 | name_info (struct ivopts_data *data, tree name) | |
483 | { | |
484 | return ver_info (data, SSA_NAME_VERSION (name)); | |
485 | } | |
486 | ||
487 | /* Checks whether there exists number X such that X * B = A, counting modulo | |
488 | 2^BITS. */ | |
489 | ||
490 | static bool | |
491 | divide (unsigned bits, unsigned HOST_WIDE_INT a, unsigned HOST_WIDE_INT b, | |
492 | HOST_WIDE_INT *x) | |
493 | { | |
494 | unsigned HOST_WIDE_INT mask = ~(~(unsigned HOST_WIDE_INT) 0 << (bits - 1) << 1); | |
495 | unsigned HOST_WIDE_INT inv, ex, val; | |
496 | unsigned i; | |
497 | ||
498 | a &= mask; | |
499 | b &= mask; | |
500 | ||
501 | /* First divide the whole equation by 2 as long as possible. */ | |
502 | while (!(a & 1) && !(b & 1)) | |
503 | { | |
504 | a >>= 1; | |
505 | b >>= 1; | |
506 | bits--; | |
507 | mask >>= 1; | |
508 | } | |
509 | ||
510 | if (!(b & 1)) | |
511 | { | |
512 | /* If b is still even, a is odd and there is no such x. */ | |
513 | return false; | |
514 | } | |
515 | ||
516 | /* Find the inverse of b. We compute it as | |
517 | b^(2^(bits - 1) - 1) (mod 2^bits). */ | |
518 | inv = 1; | |
519 | ex = b; | |
520 | for (i = 0; i < bits - 1; i++) | |
521 | { | |
522 | inv = (inv * ex) & mask; | |
523 | ex = (ex * ex) & mask; | |
524 | } | |
525 | ||
526 | val = (a * inv) & mask; | |
527 | ||
1e128c5f | 528 | gcc_assert (((val * b) & mask) == a); |
8b11a64c ZD |
529 | |
530 | if ((val >> (bits - 1)) & 1) | |
531 | val |= ~mask; | |
532 | ||
533 | *x = val; | |
534 | ||
535 | return true; | |
536 | } | |
537 | ||
538 | /* Returns true if STMT is after the place where the IP_NORMAL ivs will be | |
539 | emitted in LOOP. */ | |
540 | ||
541 | static bool | |
542 | stmt_after_ip_normal_pos (struct loop *loop, tree stmt) | |
543 | { | |
544 | basic_block bb = ip_normal_pos (loop), sbb = bb_for_stmt (stmt); | |
545 | ||
1e128c5f | 546 | gcc_assert (bb); |
8b11a64c ZD |
547 | |
548 | if (sbb == loop->latch) | |
549 | return true; | |
550 | ||
551 | if (sbb != bb) | |
552 | return false; | |
553 | ||
554 | return stmt == last_stmt (bb); | |
555 | } | |
556 | ||
557 | /* Returns true if STMT if after the place where the original induction | |
558 | variable CAND is incremented. */ | |
559 | ||
560 | static bool | |
561 | stmt_after_ip_original_pos (struct iv_cand *cand, tree stmt) | |
562 | { | |
563 | basic_block cand_bb = bb_for_stmt (cand->incremented_at); | |
564 | basic_block stmt_bb = bb_for_stmt (stmt); | |
565 | block_stmt_iterator bsi; | |
566 | ||
567 | if (!dominated_by_p (CDI_DOMINATORS, stmt_bb, cand_bb)) | |
568 | return false; | |
569 | ||
570 | if (stmt_bb != cand_bb) | |
571 | return true; | |
572 | ||
573 | /* Scan the block from the end, since the original ivs are usually | |
574 | incremented at the end of the loop body. */ | |
575 | for (bsi = bsi_last (stmt_bb); ; bsi_prev (&bsi)) | |
576 | { | |
577 | if (bsi_stmt (bsi) == cand->incremented_at) | |
578 | return false; | |
579 | if (bsi_stmt (bsi) == stmt) | |
580 | return true; | |
581 | } | |
582 | } | |
583 | ||
584 | /* Returns true if STMT if after the place where the induction variable | |
585 | CAND is incremented in LOOP. */ | |
586 | ||
587 | static bool | |
588 | stmt_after_increment (struct loop *loop, struct iv_cand *cand, tree stmt) | |
589 | { | |
590 | switch (cand->pos) | |
591 | { | |
592 | case IP_END: | |
593 | return false; | |
594 | ||
595 | case IP_NORMAL: | |
596 | return stmt_after_ip_normal_pos (loop, stmt); | |
597 | ||
598 | case IP_ORIGINAL: | |
599 | return stmt_after_ip_original_pos (cand, stmt); | |
600 | ||
601 | default: | |
1e128c5f | 602 | gcc_unreachable (); |
8b11a64c ZD |
603 | } |
604 | } | |
605 | ||
606 | /* Initializes data structures used by the iv optimization pass, stored | |
607 | in DATA. LOOPS is the loop tree. */ | |
608 | ||
609 | static void | |
610 | tree_ssa_iv_optimize_init (struct loops *loops, struct ivopts_data *data) | |
611 | { | |
612 | unsigned i; | |
613 | ||
614 | data->version_info_size = 2 * num_ssa_names; | |
615 | data->version_info = xcalloc (data->version_info_size, | |
616 | sizeof (struct version_info)); | |
617 | data->relevant = BITMAP_XMALLOC (); | |
618 | data->max_inv_id = 0; | |
619 | ||
620 | for (i = 1; i < loops->num; i++) | |
621 | if (loops->parray[i]) | |
622 | loops->parray[i]->aux = xcalloc (1, sizeof (struct loop_data)); | |
623 | ||
624 | VARRAY_GENERIC_PTR_NOGC_INIT (data->iv_uses, 20, "iv_uses"); | |
625 | VARRAY_GENERIC_PTR_NOGC_INIT (data->iv_candidates, 20, "iv_candidates"); | |
626 | VARRAY_GENERIC_PTR_NOGC_INIT (decl_rtl_to_reset, 20, "decl_rtl_to_reset"); | |
627 | } | |
628 | ||
629 | /* Allocates an induction variable with given initial value BASE and step STEP | |
630 | for loop LOOP. */ | |
631 | ||
632 | static struct iv * | |
633 | alloc_iv (tree base, tree step) | |
634 | { | |
635 | struct iv *iv = xcalloc (1, sizeof (struct iv)); | |
636 | ||
637 | if (step && integer_zerop (step)) | |
638 | step = NULL_TREE; | |
639 | ||
640 | iv->base = base; | |
641 | iv->step = step; | |
642 | iv->biv_p = false; | |
643 | iv->have_use_for = false; | |
644 | iv->use_id = 0; | |
645 | iv->ssa_name = NULL_TREE; | |
646 | ||
647 | return iv; | |
648 | } | |
649 | ||
650 | /* Sets STEP and BASE for induction variable IV. */ | |
651 | ||
652 | static void | |
653 | set_iv (struct ivopts_data *data, tree iv, tree base, tree step) | |
654 | { | |
655 | struct version_info *info = name_info (data, iv); | |
656 | ||
1e128c5f | 657 | gcc_assert (!info->iv); |
8b11a64c ZD |
658 | |
659 | bitmap_set_bit (data->relevant, SSA_NAME_VERSION (iv)); | |
660 | info->iv = alloc_iv (base, step); | |
661 | info->iv->ssa_name = iv; | |
662 | } | |
663 | ||
664 | /* Finds induction variable declaration for VAR. */ | |
665 | ||
666 | static struct iv * | |
667 | get_iv (struct ivopts_data *data, tree var) | |
668 | { | |
669 | basic_block bb; | |
670 | ||
671 | if (!name_info (data, var)->iv) | |
672 | { | |
673 | bb = bb_for_stmt (SSA_NAME_DEF_STMT (var)); | |
674 | ||
675 | if (!bb | |
676 | || !flow_bb_inside_loop_p (data->current_loop, bb)) | |
677 | set_iv (data, var, var, NULL_TREE); | |
678 | } | |
679 | ||
680 | return name_info (data, var)->iv; | |
681 | } | |
682 | ||
683 | /* Determines the step of a biv defined in PHI. */ | |
684 | ||
685 | static tree | |
686 | determine_biv_step (tree phi) | |
687 | { | |
688 | struct loop *loop = bb_for_stmt (phi)->loop_father; | |
689 | tree name = PHI_RESULT (phi), base, step; | |
690 | tree type = TREE_TYPE (name); | |
691 | ||
692 | if (!is_gimple_reg (name)) | |
693 | return NULL_TREE; | |
694 | ||
695 | if (!simple_iv (loop, phi, name, &base, &step)) | |
696 | return NULL_TREE; | |
697 | ||
698 | if (!step) | |
5212068f | 699 | return build_int_cst (type, 0); |
8b11a64c ZD |
700 | |
701 | return step; | |
702 | } | |
703 | ||
be35cf60 ZD |
704 | /* Returns true if EXP is a ssa name that occurs in an abnormal phi node. */ |
705 | ||
706 | static bool | |
707 | abnormal_ssa_name_p (tree exp) | |
708 | { | |
709 | if (!exp) | |
710 | return false; | |
711 | ||
712 | if (TREE_CODE (exp) != SSA_NAME) | |
713 | return false; | |
714 | ||
715 | return SSA_NAME_OCCURS_IN_ABNORMAL_PHI (exp) != 0; | |
716 | } | |
717 | ||
718 | /* Returns false if BASE or INDEX contains a ssa name that occurs in an | |
8b11a64c ZD |
719 | abnormal phi node. Callback for for_each_index. */ |
720 | ||
721 | static bool | |
be35cf60 | 722 | idx_contains_abnormal_ssa_name_p (tree base, tree *index, |
8b11a64c ZD |
723 | void *data ATTRIBUTE_UNUSED) |
724 | { | |
be35cf60 ZD |
725 | if (TREE_CODE (base) == ARRAY_REF) |
726 | { | |
727 | if (abnormal_ssa_name_p (TREE_OPERAND (base, 2))) | |
728 | return false; | |
729 | if (abnormal_ssa_name_p (TREE_OPERAND (base, 3))) | |
730 | return false; | |
731 | } | |
8b11a64c | 732 | |
be35cf60 | 733 | return !abnormal_ssa_name_p (*index); |
8b11a64c ZD |
734 | } |
735 | ||
736 | /* Returns true if EXPR contains a ssa name that occurs in an | |
737 | abnormal phi node. */ | |
738 | ||
739 | static bool | |
740 | contains_abnormal_ssa_name_p (tree expr) | |
741 | { | |
742 | enum tree_code code = TREE_CODE (expr); | |
6615c446 | 743 | enum tree_code_class class = TREE_CODE_CLASS (code); |
8b11a64c ZD |
744 | |
745 | if (code == SSA_NAME) | |
746 | return SSA_NAME_OCCURS_IN_ABNORMAL_PHI (expr) != 0; | |
747 | ||
748 | if (code == INTEGER_CST | |
749 | || is_gimple_min_invariant (expr)) | |
750 | return false; | |
751 | ||
752 | if (code == ADDR_EXPR) | |
753 | return !for_each_index (&TREE_OPERAND (expr, 1), | |
754 | idx_contains_abnormal_ssa_name_p, | |
755 | NULL); | |
756 | ||
757 | switch (class) | |
758 | { | |
6615c446 JO |
759 | case tcc_binary: |
760 | case tcc_comparison: | |
8b11a64c ZD |
761 | if (contains_abnormal_ssa_name_p (TREE_OPERAND (expr, 1))) |
762 | return true; | |
763 | ||
764 | /* Fallthru. */ | |
6615c446 | 765 | case tcc_unary: |
8b11a64c ZD |
766 | if (contains_abnormal_ssa_name_p (TREE_OPERAND (expr, 0))) |
767 | return true; | |
768 | ||
769 | break; | |
770 | ||
771 | default: | |
1e128c5f | 772 | gcc_unreachable (); |
8b11a64c ZD |
773 | } |
774 | ||
775 | return false; | |
776 | } | |
777 | ||
778 | /* Finds basic ivs. */ | |
779 | ||
780 | static bool | |
781 | find_bivs (struct ivopts_data *data) | |
782 | { | |
783 | tree phi, step, type, base; | |
784 | bool found = false; | |
785 | struct loop *loop = data->current_loop; | |
786 | ||
787 | for (phi = phi_nodes (loop->header); phi; phi = TREE_CHAIN (phi)) | |
788 | { | |
789 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (PHI_RESULT (phi))) | |
790 | continue; | |
791 | ||
792 | step = determine_biv_step (phi); | |
793 | ||
794 | if (!step) | |
795 | continue; | |
796 | if (cst_and_fits_in_hwi (step) | |
797 | && int_cst_value (step) == 0) | |
798 | continue; | |
799 | ||
800 | base = PHI_ARG_DEF_FROM_EDGE (phi, loop_preheader_edge (loop)); | |
801 | if (contains_abnormal_ssa_name_p (base)) | |
802 | continue; | |
803 | ||
804 | type = TREE_TYPE (PHI_RESULT (phi)); | |
805 | base = fold_convert (type, base); | |
806 | step = fold_convert (type, step); | |
807 | ||
808 | /* FIXME: We do not handle induction variables whose step does | |
809 | not satisfy cst_and_fits_in_hwi. */ | |
810 | if (!cst_and_fits_in_hwi (step)) | |
811 | continue; | |
812 | ||
813 | set_iv (data, PHI_RESULT (phi), base, step); | |
814 | found = true; | |
815 | } | |
816 | ||
817 | return found; | |
818 | } | |
819 | ||
820 | /* Marks basic ivs. */ | |
821 | ||
822 | static void | |
823 | mark_bivs (struct ivopts_data *data) | |
824 | { | |
825 | tree phi, var; | |
826 | struct iv *iv, *incr_iv; | |
827 | struct loop *loop = data->current_loop; | |
828 | basic_block incr_bb; | |
829 | ||
830 | for (phi = phi_nodes (loop->header); phi; phi = TREE_CHAIN (phi)) | |
831 | { | |
832 | iv = get_iv (data, PHI_RESULT (phi)); | |
833 | if (!iv) | |
834 | continue; | |
835 | ||
836 | var = PHI_ARG_DEF_FROM_EDGE (phi, loop_latch_edge (loop)); | |
837 | incr_iv = get_iv (data, var); | |
838 | if (!incr_iv) | |
839 | continue; | |
840 | ||
841 | /* If the increment is in the subloop, ignore it. */ | |
842 | incr_bb = bb_for_stmt (SSA_NAME_DEF_STMT (var)); | |
843 | if (incr_bb->loop_father != data->current_loop | |
844 | || (incr_bb->flags & BB_IRREDUCIBLE_LOOP)) | |
845 | continue; | |
846 | ||
847 | iv->biv_p = true; | |
848 | incr_iv->biv_p = true; | |
849 | } | |
850 | } | |
851 | ||
852 | /* Checks whether STMT defines a linear induction variable and stores its | |
853 | parameters to BASE and STEP. */ | |
854 | ||
855 | static bool | |
856 | find_givs_in_stmt_scev (struct ivopts_data *data, tree stmt, | |
857 | tree *base, tree *step) | |
858 | { | |
859 | tree lhs; | |
860 | struct loop *loop = data->current_loop; | |
861 | ||
862 | *base = NULL_TREE; | |
863 | *step = NULL_TREE; | |
864 | ||
865 | if (TREE_CODE (stmt) != MODIFY_EXPR) | |
866 | return false; | |
867 | ||
868 | lhs = TREE_OPERAND (stmt, 0); | |
869 | if (TREE_CODE (lhs) != SSA_NAME) | |
870 | return false; | |
871 | ||
872 | if (!simple_iv (loop, stmt, TREE_OPERAND (stmt, 1), base, step)) | |
873 | return false; | |
874 | ||
875 | /* FIXME: We do not handle induction variables whose step does | |
876 | not satisfy cst_and_fits_in_hwi. */ | |
877 | if (!zero_p (*step) | |
878 | && !cst_and_fits_in_hwi (*step)) | |
879 | return false; | |
880 | ||
881 | if (contains_abnormal_ssa_name_p (*base)) | |
882 | return false; | |
883 | ||
884 | return true; | |
885 | } | |
886 | ||
887 | /* Finds general ivs in statement STMT. */ | |
888 | ||
889 | static void | |
890 | find_givs_in_stmt (struct ivopts_data *data, tree stmt) | |
891 | { | |
892 | tree base, step; | |
893 | ||
894 | if (!find_givs_in_stmt_scev (data, stmt, &base, &step)) | |
895 | return; | |
896 | ||
897 | set_iv (data, TREE_OPERAND (stmt, 0), base, step); | |
898 | } | |
899 | ||
900 | /* Finds general ivs in basic block BB. */ | |
901 | ||
902 | static void | |
903 | find_givs_in_bb (struct ivopts_data *data, basic_block bb) | |
904 | { | |
905 | block_stmt_iterator bsi; | |
906 | ||
907 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
908 | find_givs_in_stmt (data, bsi_stmt (bsi)); | |
909 | } | |
910 | ||
911 | /* Finds general ivs. */ | |
912 | ||
913 | static void | |
914 | find_givs (struct ivopts_data *data) | |
915 | { | |
916 | struct loop *loop = data->current_loop; | |
917 | basic_block *body = get_loop_body_in_dom_order (loop); | |
918 | unsigned i; | |
919 | ||
920 | for (i = 0; i < loop->num_nodes; i++) | |
921 | find_givs_in_bb (data, body[i]); | |
922 | free (body); | |
923 | } | |
924 | ||
925 | /* Determine the number of iterations of the current loop. */ | |
926 | ||
927 | static void | |
928 | determine_number_of_iterations (struct ivopts_data *data) | |
929 | { | |
930 | struct loop *loop = data->current_loop; | |
931 | edge exit = single_dom_exit (loop); | |
932 | ||
933 | if (!exit) | |
934 | return; | |
935 | ||
936 | number_of_iterations_exit (loop, exit, &loop_data (loop)->niter); | |
937 | } | |
938 | ||
939 | /* For each ssa name defined in LOOP determines whether it is an induction | |
940 | variable and if so, its initial value and step. */ | |
941 | ||
942 | static bool | |
943 | find_induction_variables (struct ivopts_data *data) | |
944 | { | |
945 | unsigned i; | |
946 | struct loop *loop = data->current_loop; | |
87c476a2 | 947 | bitmap_iterator bi; |
8b11a64c ZD |
948 | |
949 | if (!find_bivs (data)) | |
950 | return false; | |
951 | ||
952 | find_givs (data); | |
953 | mark_bivs (data); | |
954 | determine_number_of_iterations (data); | |
955 | ||
956 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
957 | { | |
958 | if (loop_data (loop)->niter.niter) | |
959 | { | |
960 | fprintf (dump_file, " number of iterations "); | |
961 | print_generic_expr (dump_file, loop_data (loop)->niter.niter, | |
962 | TDF_SLIM); | |
963 | fprintf (dump_file, "\n"); | |
964 | ||
965 | fprintf (dump_file, " may be zero if "); | |
966 | print_generic_expr (dump_file, loop_data (loop)->niter.may_be_zero, | |
967 | TDF_SLIM); | |
968 | fprintf (dump_file, "\n"); | |
969 | ||
970 | fprintf (dump_file, " bogus unless "); | |
971 | print_generic_expr (dump_file, loop_data (loop)->niter.assumptions, | |
972 | TDF_SLIM); | |
973 | fprintf (dump_file, "\n"); | |
974 | fprintf (dump_file, "\n"); | |
975 | }; | |
976 | ||
977 | fprintf (dump_file, "Induction variables:\n\n"); | |
978 | ||
87c476a2 | 979 | EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi) |
8b11a64c ZD |
980 | { |
981 | if (ver_info (data, i)->iv) | |
982 | dump_iv (dump_file, ver_info (data, i)->iv); | |
87c476a2 | 983 | } |
8b11a64c ZD |
984 | } |
985 | ||
986 | return true; | |
987 | } | |
988 | ||
989 | /* Records a use of type USE_TYPE at *USE_P in STMT whose value is IV. */ | |
990 | ||
991 | static struct iv_use * | |
992 | record_use (struct ivopts_data *data, tree *use_p, struct iv *iv, | |
993 | tree stmt, enum use_type use_type) | |
994 | { | |
995 | struct iv_use *use = xcalloc (1, sizeof (struct iv_use)); | |
996 | ||
997 | use->id = n_iv_uses (data); | |
998 | use->type = use_type; | |
999 | use->iv = iv; | |
1000 | use->stmt = stmt; | |
1001 | use->op_p = use_p; | |
1002 | use->related_cands = BITMAP_XMALLOC (); | |
1003 | ||
1004 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1005 | dump_use (dump_file, use); | |
1006 | ||
1007 | VARRAY_PUSH_GENERIC_PTR_NOGC (data->iv_uses, use); | |
1008 | ||
1009 | return use; | |
1010 | } | |
1011 | ||
1012 | /* Checks whether OP is a loop-level invariant and if so, records it. | |
1013 | NONLINEAR_USE is true if the invariant is used in a way we do not | |
1014 | handle specially. */ | |
1015 | ||
1016 | static void | |
1017 | record_invariant (struct ivopts_data *data, tree op, bool nonlinear_use) | |
1018 | { | |
1019 | basic_block bb; | |
1020 | struct version_info *info; | |
1021 | ||
1022 | if (TREE_CODE (op) != SSA_NAME | |
1023 | || !is_gimple_reg (op)) | |
1024 | return; | |
1025 | ||
1026 | bb = bb_for_stmt (SSA_NAME_DEF_STMT (op)); | |
1027 | if (bb | |
1028 | && flow_bb_inside_loop_p (data->current_loop, bb)) | |
1029 | return; | |
1030 | ||
1031 | info = name_info (data, op); | |
1032 | info->name = op; | |
1033 | info->has_nonlin_use |= nonlinear_use; | |
1034 | if (!info->inv_id) | |
1035 | info->inv_id = ++data->max_inv_id; | |
1036 | bitmap_set_bit (data->relevant, SSA_NAME_VERSION (op)); | |
1037 | } | |
1038 | ||
1039 | /* Checks whether the use OP is interesting and if so, records it | |
1040 | as TYPE. */ | |
1041 | ||
1042 | static struct iv_use * | |
1043 | find_interesting_uses_outer_or_nonlin (struct ivopts_data *data, tree op, | |
1044 | enum use_type type) | |
1045 | { | |
1046 | struct iv *iv; | |
1047 | struct iv *civ; | |
1048 | tree stmt; | |
1049 | struct iv_use *use; | |
1050 | ||
1051 | if (TREE_CODE (op) != SSA_NAME) | |
1052 | return NULL; | |
1053 | ||
1054 | iv = get_iv (data, op); | |
1055 | if (!iv) | |
1056 | return NULL; | |
1057 | ||
1058 | if (iv->have_use_for) | |
1059 | { | |
1060 | use = iv_use (data, iv->use_id); | |
1061 | ||
1e128c5f GB |
1062 | gcc_assert (use->type == USE_NONLINEAR_EXPR |
1063 | || use->type == USE_OUTER); | |
8b11a64c ZD |
1064 | |
1065 | if (type == USE_NONLINEAR_EXPR) | |
1066 | use->type = USE_NONLINEAR_EXPR; | |
1067 | return use; | |
1068 | } | |
1069 | ||
1070 | if (zero_p (iv->step)) | |
1071 | { | |
1072 | record_invariant (data, op, true); | |
1073 | return NULL; | |
1074 | } | |
1075 | iv->have_use_for = true; | |
1076 | ||
1077 | civ = xmalloc (sizeof (struct iv)); | |
1078 | *civ = *iv; | |
1079 | ||
1080 | stmt = SSA_NAME_DEF_STMT (op); | |
1e128c5f GB |
1081 | gcc_assert (TREE_CODE (stmt) == PHI_NODE |
1082 | || TREE_CODE (stmt) == MODIFY_EXPR); | |
8b11a64c ZD |
1083 | |
1084 | use = record_use (data, NULL, civ, stmt, type); | |
1085 | iv->use_id = use->id; | |
1086 | ||
1087 | return use; | |
1088 | } | |
1089 | ||
1090 | /* Checks whether the use OP is interesting and if so, records it. */ | |
1091 | ||
1092 | static struct iv_use * | |
1093 | find_interesting_uses_op (struct ivopts_data *data, tree op) | |
1094 | { | |
1095 | return find_interesting_uses_outer_or_nonlin (data, op, USE_NONLINEAR_EXPR); | |
1096 | } | |
1097 | ||
1098 | /* Records a definition of induction variable OP that is used outside of the | |
1099 | loop. */ | |
1100 | ||
1101 | static struct iv_use * | |
1102 | find_interesting_uses_outer (struct ivopts_data *data, tree op) | |
1103 | { | |
1104 | return find_interesting_uses_outer_or_nonlin (data, op, USE_OUTER); | |
1105 | } | |
1106 | ||
1107 | /* Checks whether the condition *COND_P in STMT is interesting | |
1108 | and if so, records it. */ | |
1109 | ||
1110 | static void | |
1111 | find_interesting_uses_cond (struct ivopts_data *data, tree stmt, tree *cond_p) | |
1112 | { | |
1113 | tree *op0_p; | |
1114 | tree *op1_p; | |
1115 | struct iv *iv0 = NULL, *iv1 = NULL, *civ; | |
1116 | struct iv const_iv; | |
1117 | tree zero = integer_zero_node; | |
1118 | ||
1119 | const_iv.step = NULL_TREE; | |
1120 | ||
1121 | if (integer_zerop (*cond_p) | |
1122 | || integer_nonzerop (*cond_p)) | |
1123 | return; | |
1124 | ||
1125 | if (TREE_CODE (*cond_p) == SSA_NAME) | |
1126 | { | |
1127 | op0_p = cond_p; | |
1128 | op1_p = &zero; | |
1129 | } | |
1130 | else | |
1131 | { | |
1132 | op0_p = &TREE_OPERAND (*cond_p, 0); | |
1133 | op1_p = &TREE_OPERAND (*cond_p, 1); | |
1134 | } | |
1135 | ||
1136 | if (TREE_CODE (*op0_p) == SSA_NAME) | |
1137 | iv0 = get_iv (data, *op0_p); | |
1138 | else | |
1139 | iv0 = &const_iv; | |
1140 | ||
1141 | if (TREE_CODE (*op1_p) == SSA_NAME) | |
1142 | iv1 = get_iv (data, *op1_p); | |
1143 | else | |
1144 | iv1 = &const_iv; | |
1145 | ||
1146 | if (/* When comparing with non-invariant value, we may not do any senseful | |
1147 | induction variable elimination. */ | |
1148 | (!iv0 || !iv1) | |
1149 | /* Eliminating condition based on two ivs would be nontrivial. | |
1150 | ??? TODO -- it is not really important to handle this case. */ | |
1151 | || (!zero_p (iv0->step) && !zero_p (iv1->step))) | |
1152 | { | |
1153 | find_interesting_uses_op (data, *op0_p); | |
1154 | find_interesting_uses_op (data, *op1_p); | |
1155 | return; | |
1156 | } | |
1157 | ||
1158 | if (zero_p (iv0->step) && zero_p (iv1->step)) | |
1159 | { | |
1160 | /* If both are invariants, this is a work for unswitching. */ | |
1161 | return; | |
1162 | } | |
1163 | ||
1164 | civ = xmalloc (sizeof (struct iv)); | |
1165 | *civ = zero_p (iv0->step) ? *iv1: *iv0; | |
1166 | record_use (data, cond_p, civ, stmt, USE_COMPARE); | |
1167 | } | |
1168 | ||
be35cf60 ZD |
1169 | /* Returns true if expression EXPR is obviously invariant in LOOP, |
1170 | i.e. if all its operands are defined outside of the LOOP. */ | |
1171 | ||
1172 | static bool | |
1173 | expr_invariant_in_loop_p (struct loop *loop, tree expr) | |
1174 | { | |
1175 | basic_block def_bb; | |
1176 | unsigned i, len; | |
1177 | ||
1178 | if (is_gimple_min_invariant (expr)) | |
1179 | return true; | |
1180 | ||
1181 | if (TREE_CODE (expr) == SSA_NAME) | |
1182 | { | |
1183 | def_bb = bb_for_stmt (SSA_NAME_DEF_STMT (expr)); | |
1184 | if (def_bb | |
1185 | && flow_bb_inside_loop_p (loop, def_bb)) | |
1186 | return false; | |
1187 | ||
1188 | return true; | |
1189 | } | |
1190 | ||
1191 | if (!EXPR_P (expr)) | |
1192 | return false; | |
1193 | ||
1194 | len = first_rtl_op (TREE_CODE (expr)); | |
1195 | for (i = 0; i < len; i++) | |
1196 | if (!expr_invariant_in_loop_p (loop, TREE_OPERAND (expr, i))) | |
1197 | return false; | |
1198 | ||
1199 | return true; | |
1200 | } | |
1201 | ||
8b11a64c ZD |
1202 | /* Cumulates the steps of indices into DATA and replaces their values with the |
1203 | initial ones. Returns false when the value of the index cannot be determined. | |
1204 | Callback for for_each_index. */ | |
1205 | ||
1206 | struct ifs_ivopts_data | |
1207 | { | |
1208 | struct ivopts_data *ivopts_data; | |
1209 | tree stmt; | |
1210 | tree *step_p; | |
1211 | }; | |
1212 | ||
1213 | static bool | |
1214 | idx_find_step (tree base, tree *idx, void *data) | |
1215 | { | |
1216 | struct ifs_ivopts_data *dta = data; | |
1217 | struct iv *iv; | |
be35cf60 | 1218 | tree step, type, iv_type, iv_step, lbound, off; |
2f4675b4 | 1219 | struct loop *loop = dta->ivopts_data->current_loop; |
be35cf60 ZD |
1220 | |
1221 | if (TREE_CODE (base) == MISALIGNED_INDIRECT_REF | |
1222 | || TREE_CODE (base) == ALIGN_INDIRECT_REF) | |
1223 | return false; | |
1224 | ||
1225 | /* If base is a component ref, require that the offset of the reference | |
1226 | is invariant. */ | |
1227 | if (TREE_CODE (base) == COMPONENT_REF) | |
1228 | { | |
1229 | off = component_ref_field_offset (base); | |
1230 | return expr_invariant_in_loop_p (loop, off); | |
1231 | } | |
1232 | ||
1233 | /* If base is array, first check whether we will be able to move the | |
1234 | reference out of the loop (in order to take its address in strength | |
1235 | reduction). In order for this to work we need both lower bound | |
1236 | and step to be loop invariants. */ | |
1237 | if (TREE_CODE (base) == ARRAY_REF) | |
1238 | { | |
1239 | step = array_ref_element_size (base); | |
1240 | lbound = array_ref_low_bound (base); | |
1241 | ||
1242 | if (!expr_invariant_in_loop_p (loop, step) | |
1243 | || !expr_invariant_in_loop_p (loop, lbound)) | |
1244 | return false; | |
1245 | } | |
1246 | ||
8b11a64c ZD |
1247 | if (TREE_CODE (*idx) != SSA_NAME) |
1248 | return true; | |
1249 | ||
1250 | iv = get_iv (dta->ivopts_data, *idx); | |
1251 | if (!iv) | |
1252 | return false; | |
1253 | ||
1254 | *idx = iv->base; | |
1255 | ||
1256 | if (!iv->step) | |
1257 | return true; | |
1258 | ||
1259 | iv_type = TREE_TYPE (iv->base); | |
1260 | type = build_pointer_type (TREE_TYPE (base)); | |
1261 | if (TREE_CODE (base) == ARRAY_REF) | |
2f4675b4 ZD |
1262 | { |
1263 | step = array_ref_element_size (base); | |
2f4675b4 ZD |
1264 | |
1265 | /* We only handle addresses whose step is an integer constant. */ | |
1266 | if (TREE_CODE (step) != INTEGER_CST) | |
1267 | return false; | |
2f4675b4 | 1268 | } |
8b11a64c | 1269 | else |
5212068f NS |
1270 | /* The step for pointer arithmetics already is 1 byte. */ |
1271 | step = build_int_cst (type, 1); | |
8b11a64c ZD |
1272 | |
1273 | if (TYPE_PRECISION (iv_type) < TYPE_PRECISION (type)) | |
1274 | iv_step = can_count_iv_in_wider_type (dta->ivopts_data->current_loop, | |
1275 | type, iv->base, iv->step, dta->stmt); | |
1276 | else | |
1277 | iv_step = fold_convert (iv_type, iv->step); | |
1278 | ||
1279 | if (!iv_step) | |
1280 | { | |
1281 | /* The index might wrap. */ | |
1282 | return false; | |
1283 | } | |
1284 | ||
1285 | step = EXEC_BINARY (MULT_EXPR, type, step, iv_step); | |
1286 | ||
1287 | if (!*dta->step_p) | |
1288 | *dta->step_p = step; | |
1289 | else | |
1290 | *dta->step_p = EXEC_BINARY (PLUS_EXPR, type, *dta->step_p, step); | |
1291 | ||
1292 | return true; | |
1293 | } | |
1294 | ||
1295 | /* Records use in index IDX. Callback for for_each_index. Ivopts data | |
1296 | object is passed to it in DATA. */ | |
1297 | ||
1298 | static bool | |
2f4675b4 | 1299 | idx_record_use (tree base, tree *idx, |
8b11a64c ZD |
1300 | void *data) |
1301 | { | |
1302 | find_interesting_uses_op (data, *idx); | |
2f4675b4 ZD |
1303 | if (TREE_CODE (base) == ARRAY_REF) |
1304 | { | |
1305 | find_interesting_uses_op (data, array_ref_element_size (base)); | |
1306 | find_interesting_uses_op (data, array_ref_low_bound (base)); | |
1307 | } | |
8b11a64c ZD |
1308 | return true; |
1309 | } | |
1310 | ||
1311 | /* Finds addresses in *OP_P inside STMT. */ | |
1312 | ||
1313 | static void | |
1314 | find_interesting_uses_address (struct ivopts_data *data, tree stmt, tree *op_p) | |
1315 | { | |
1316 | tree base = unshare_expr (*op_p), step = NULL; | |
1317 | struct iv *civ; | |
1318 | struct ifs_ivopts_data ifs_ivopts_data; | |
1319 | ||
1320 | /* Ignore bitfields for now. Not really something terribly complicated | |
1321 | to handle. TODO. */ | |
1322 | if (TREE_CODE (base) == COMPONENT_REF | |
1323 | && DECL_NONADDRESSABLE_P (TREE_OPERAND (base, 1))) | |
1324 | goto fail; | |
1325 | ||
1326 | ifs_ivopts_data.ivopts_data = data; | |
1327 | ifs_ivopts_data.stmt = stmt; | |
1328 | ifs_ivopts_data.step_p = &step; | |
1329 | if (!for_each_index (&base, idx_find_step, &ifs_ivopts_data) | |
1330 | || zero_p (step)) | |
1331 | goto fail; | |
1332 | ||
be35cf60 ZD |
1333 | gcc_assert (TREE_CODE (base) != ALIGN_INDIRECT_REF); |
1334 | gcc_assert (TREE_CODE (base) != MISALIGNED_INDIRECT_REF); | |
1335 | ||
1336 | if (TREE_CODE (base) == INDIRECT_REF) | |
8b11a64c ZD |
1337 | base = TREE_OPERAND (base, 0); |
1338 | else | |
1339 | base = build_addr (base); | |
1340 | ||
1341 | civ = alloc_iv (base, step); | |
1342 | record_use (data, op_p, civ, stmt, USE_ADDRESS); | |
1343 | return; | |
1344 | ||
1345 | fail: | |
1346 | for_each_index (op_p, idx_record_use, data); | |
1347 | } | |
1348 | ||
1349 | /* Finds and records invariants used in STMT. */ | |
1350 | ||
1351 | static void | |
1352 | find_invariants_stmt (struct ivopts_data *data, tree stmt) | |
1353 | { | |
1354 | use_optype uses = NULL; | |
1355 | unsigned i, n; | |
1356 | tree op; | |
1357 | ||
1358 | if (TREE_CODE (stmt) == PHI_NODE) | |
1359 | n = PHI_NUM_ARGS (stmt); | |
1360 | else | |
1361 | { | |
1362 | get_stmt_operands (stmt); | |
1363 | uses = STMT_USE_OPS (stmt); | |
1364 | n = NUM_USES (uses); | |
1365 | } | |
1366 | ||
1367 | for (i = 0; i < n; i++) | |
1368 | { | |
1369 | if (TREE_CODE (stmt) == PHI_NODE) | |
1370 | op = PHI_ARG_DEF (stmt, i); | |
1371 | else | |
1372 | op = USE_OP (uses, i); | |
1373 | ||
1374 | record_invariant (data, op, false); | |
1375 | } | |
1376 | } | |
1377 | ||
1378 | /* Finds interesting uses of induction variables in the statement STMT. */ | |
1379 | ||
1380 | static void | |
1381 | find_interesting_uses_stmt (struct ivopts_data *data, tree stmt) | |
1382 | { | |
1383 | struct iv *iv; | |
1384 | tree op, lhs, rhs; | |
1385 | use_optype uses = NULL; | |
1386 | unsigned i, n; | |
1387 | ||
1388 | find_invariants_stmt (data, stmt); | |
1389 | ||
1390 | if (TREE_CODE (stmt) == COND_EXPR) | |
1391 | { | |
1392 | find_interesting_uses_cond (data, stmt, &COND_EXPR_COND (stmt)); | |
1393 | return; | |
1394 | } | |
1395 | ||
1396 | if (TREE_CODE (stmt) == MODIFY_EXPR) | |
1397 | { | |
1398 | lhs = TREE_OPERAND (stmt, 0); | |
1399 | rhs = TREE_OPERAND (stmt, 1); | |
1400 | ||
1401 | if (TREE_CODE (lhs) == SSA_NAME) | |
1402 | { | |
1403 | /* If the statement defines an induction variable, the uses are not | |
1404 | interesting by themselves. */ | |
1405 | ||
1406 | iv = get_iv (data, lhs); | |
1407 | ||
1408 | if (iv && !zero_p (iv->step)) | |
1409 | return; | |
1410 | } | |
1411 | ||
1412 | switch (TREE_CODE_CLASS (TREE_CODE (rhs))) | |
1413 | { | |
6615c446 | 1414 | case tcc_comparison: |
8b11a64c ZD |
1415 | find_interesting_uses_cond (data, stmt, &TREE_OPERAND (stmt, 1)); |
1416 | return; | |
1417 | ||
6615c446 | 1418 | case tcc_reference: |
8b11a64c | 1419 | find_interesting_uses_address (data, stmt, &TREE_OPERAND (stmt, 1)); |
6615c446 | 1420 | if (REFERENCE_CLASS_P (lhs)) |
8b11a64c ZD |
1421 | find_interesting_uses_address (data, stmt, &TREE_OPERAND (stmt, 0)); |
1422 | return; | |
1423 | ||
1424 | default: ; | |
1425 | } | |
1426 | ||
6615c446 | 1427 | if (REFERENCE_CLASS_P (lhs) |
2f4675b4 | 1428 | && is_gimple_val (rhs)) |
8b11a64c ZD |
1429 | { |
1430 | find_interesting_uses_address (data, stmt, &TREE_OPERAND (stmt, 0)); | |
1431 | find_interesting_uses_op (data, rhs); | |
1432 | return; | |
1433 | } | |
2f4675b4 ZD |
1434 | |
1435 | /* TODO -- we should also handle address uses of type | |
1436 | ||
1437 | memory = call (whatever); | |
1438 | ||
1439 | and | |
1440 | ||
1441 | call (memory). */ | |
8b11a64c ZD |
1442 | } |
1443 | ||
1444 | if (TREE_CODE (stmt) == PHI_NODE | |
1445 | && bb_for_stmt (stmt) == data->current_loop->header) | |
1446 | { | |
1447 | lhs = PHI_RESULT (stmt); | |
1448 | iv = get_iv (data, lhs); | |
1449 | ||
1450 | if (iv && !zero_p (iv->step)) | |
1451 | return; | |
1452 | } | |
1453 | ||
1454 | if (TREE_CODE (stmt) == PHI_NODE) | |
1455 | n = PHI_NUM_ARGS (stmt); | |
1456 | else | |
1457 | { | |
1458 | uses = STMT_USE_OPS (stmt); | |
1459 | n = NUM_USES (uses); | |
1460 | } | |
1461 | ||
1462 | for (i = 0; i < n; i++) | |
1463 | { | |
1464 | if (TREE_CODE (stmt) == PHI_NODE) | |
1465 | op = PHI_ARG_DEF (stmt, i); | |
1466 | else | |
1467 | op = USE_OP (uses, i); | |
1468 | ||
1469 | if (TREE_CODE (op) != SSA_NAME) | |
1470 | continue; | |
1471 | ||
1472 | iv = get_iv (data, op); | |
1473 | if (!iv) | |
1474 | continue; | |
1475 | ||
1476 | find_interesting_uses_op (data, op); | |
1477 | } | |
1478 | } | |
1479 | ||
1480 | /* Finds interesting uses of induction variables outside of loops | |
1481 | on loop exit edge EXIT. */ | |
1482 | ||
1483 | static void | |
1484 | find_interesting_uses_outside (struct ivopts_data *data, edge exit) | |
1485 | { | |
1486 | tree phi, def; | |
1487 | ||
1488 | for (phi = phi_nodes (exit->dest); phi; phi = TREE_CHAIN (phi)) | |
1489 | { | |
1490 | def = PHI_ARG_DEF_FROM_EDGE (phi, exit); | |
1491 | find_interesting_uses_outer (data, def); | |
1492 | } | |
1493 | } | |
1494 | ||
1495 | /* Finds uses of the induction variables that are interesting. */ | |
1496 | ||
1497 | static void | |
1498 | find_interesting_uses (struct ivopts_data *data) | |
1499 | { | |
1500 | basic_block bb; | |
1501 | block_stmt_iterator bsi; | |
1502 | tree phi; | |
1503 | basic_block *body = get_loop_body (data->current_loop); | |
1504 | unsigned i; | |
1505 | struct version_info *info; | |
1506 | edge e; | |
1507 | ||
1508 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1509 | fprintf (dump_file, "Uses:\n\n"); | |
1510 | ||
1511 | for (i = 0; i < data->current_loop->num_nodes; i++) | |
1512 | { | |
628f6a4e | 1513 | edge_iterator ei; |
8b11a64c ZD |
1514 | bb = body[i]; |
1515 | ||
628f6a4e | 1516 | FOR_EACH_EDGE (e, ei, bb->succs) |
8b11a64c ZD |
1517 | if (e->dest != EXIT_BLOCK_PTR |
1518 | && !flow_bb_inside_loop_p (data->current_loop, e->dest)) | |
1519 | find_interesting_uses_outside (data, e); | |
1520 | ||
1521 | for (phi = phi_nodes (bb); phi; phi = TREE_CHAIN (phi)) | |
1522 | find_interesting_uses_stmt (data, phi); | |
1523 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
1524 | find_interesting_uses_stmt (data, bsi_stmt (bsi)); | |
1525 | } | |
1526 | ||
1527 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1528 | { | |
87c476a2 ZD |
1529 | bitmap_iterator bi; |
1530 | ||
8b11a64c ZD |
1531 | fprintf (dump_file, "\n"); |
1532 | ||
87c476a2 | 1533 | EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi) |
8b11a64c ZD |
1534 | { |
1535 | info = ver_info (data, i); | |
1536 | if (info->inv_id) | |
1537 | { | |
1538 | fprintf (dump_file, " "); | |
1539 | print_generic_expr (dump_file, info->name, TDF_SLIM); | |
1540 | fprintf (dump_file, " is invariant (%d)%s\n", | |
1541 | info->inv_id, info->has_nonlin_use ? "" : ", eliminable"); | |
1542 | } | |
87c476a2 | 1543 | } |
8b11a64c ZD |
1544 | |
1545 | fprintf (dump_file, "\n"); | |
1546 | } | |
1547 | ||
1548 | free (body); | |
1549 | } | |
1550 | ||
1551 | /* Adds a candidate BASE + STEP * i. Important field is set to IMPORTANT and | |
1552 | position to POS. If USE is not NULL, the candidate is set as related to | |
1553 | it. If both BASE and STEP are NULL, we add a pseudocandidate for the | |
1554 | replacement of the final value of the iv by a direct computation. */ | |
1555 | ||
1556 | static struct iv_cand * | |
1557 | add_candidate_1 (struct ivopts_data *data, | |
1558 | tree base, tree step, bool important, enum iv_position pos, | |
1559 | struct iv_use *use, tree incremented_at) | |
1560 | { | |
1561 | unsigned i; | |
1562 | struct iv_cand *cand = NULL; | |
1563 | tree type; | |
1564 | ||
1565 | if (base) | |
1566 | { | |
1567 | type = TREE_TYPE (base); | |
1568 | if (!TYPE_UNSIGNED (type)) | |
1569 | { | |
1570 | type = unsigned_type_for (type); | |
1571 | base = fold_convert (type, base); | |
1572 | if (step) | |
1573 | step = fold_convert (type, step); | |
1574 | } | |
1575 | } | |
1576 | ||
1577 | for (i = 0; i < n_iv_cands (data); i++) | |
1578 | { | |
1579 | cand = iv_cand (data, i); | |
1580 | ||
1581 | if (cand->pos != pos) | |
1582 | continue; | |
1583 | ||
1584 | if (cand->incremented_at != incremented_at) | |
1585 | continue; | |
1586 | ||
1587 | if (!cand->iv) | |
1588 | { | |
1589 | if (!base && !step) | |
1590 | break; | |
1591 | ||
1592 | continue; | |
1593 | } | |
1594 | ||
1595 | if (!base && !step) | |
1596 | continue; | |
1597 | ||
1598 | if (!operand_equal_p (base, cand->iv->base, 0)) | |
1599 | continue; | |
1600 | ||
1601 | if (zero_p (cand->iv->step)) | |
1602 | { | |
1603 | if (zero_p (step)) | |
1604 | break; | |
1605 | } | |
1606 | else | |
1607 | { | |
1608 | if (step && operand_equal_p (step, cand->iv->step, 0)) | |
1609 | break; | |
1610 | } | |
1611 | } | |
1612 | ||
1613 | if (i == n_iv_cands (data)) | |
1614 | { | |
1615 | cand = xcalloc (1, sizeof (struct iv_cand)); | |
1616 | cand->id = i; | |
1617 | ||
1618 | if (!base && !step) | |
1619 | cand->iv = NULL; | |
1620 | else | |
1621 | cand->iv = alloc_iv (base, step); | |
1622 | ||
1623 | cand->pos = pos; | |
1624 | if (pos != IP_ORIGINAL && cand->iv) | |
1625 | { | |
1626 | cand->var_before = create_tmp_var_raw (TREE_TYPE (base), "ivtmp"); | |
1627 | cand->var_after = cand->var_before; | |
1628 | } | |
1629 | cand->important = important; | |
1630 | cand->incremented_at = incremented_at; | |
1631 | VARRAY_PUSH_GENERIC_PTR_NOGC (data->iv_candidates, cand); | |
1632 | ||
1633 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1634 | dump_cand (dump_file, cand); | |
1635 | } | |
1636 | ||
1637 | if (important && !cand->important) | |
1638 | { | |
1639 | cand->important = true; | |
1640 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1641 | fprintf (dump_file, "Candidate %d is important\n", cand->id); | |
1642 | } | |
1643 | ||
1644 | if (use) | |
1645 | { | |
1646 | bitmap_set_bit (use->related_cands, i); | |
1647 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1648 | fprintf (dump_file, "Candidate %d is related to use %d\n", | |
1649 | cand->id, use->id); | |
1650 | } | |
1651 | ||
1652 | return cand; | |
1653 | } | |
1654 | ||
1655 | /* Adds a candidate BASE + STEP * i. Important field is set to IMPORTANT and | |
1656 | position to POS. If USE is not NULL, the candidate is set as related to | |
1657 | it. The candidate computation is scheduled on all available positions. */ | |
1658 | ||
1659 | static void | |
1660 | add_candidate (struct ivopts_data *data, | |
1661 | tree base, tree step, bool important, struct iv_use *use) | |
1662 | { | |
1663 | if (ip_normal_pos (data->current_loop)) | |
1664 | add_candidate_1 (data, base, step, important, IP_NORMAL, use, NULL_TREE); | |
1665 | if (ip_end_pos (data->current_loop)) | |
1666 | add_candidate_1 (data, base, step, important, IP_END, use, NULL_TREE); | |
1667 | } | |
1668 | ||
1669 | /* Adds standard iv candidates. */ | |
1670 | ||
1671 | static void | |
1672 | add_standard_iv_candidates (struct ivopts_data *data) | |
1673 | { | |
1674 | /* Add 0 + 1 * iteration candidate. */ | |
1675 | add_candidate (data, | |
8679c649 JH |
1676 | build_int_cst (unsigned_intSI_type_node, 0), |
1677 | build_int_cst (unsigned_intSI_type_node, 1), | |
8b11a64c ZD |
1678 | true, NULL); |
1679 | ||
229031d0 | 1680 | /* The same for a long type if it is still fast enough. */ |
8679c649 JH |
1681 | if (BITS_PER_WORD > 32) |
1682 | add_candidate (data, | |
1683 | build_int_cst (unsigned_intDI_type_node, 0), | |
1684 | build_int_cst (unsigned_intDI_type_node, 1), | |
1685 | true, NULL); | |
8b11a64c ZD |
1686 | } |
1687 | ||
1688 | ||
1689 | /* Adds candidates bases on the old induction variable IV. */ | |
1690 | ||
1691 | static void | |
1692 | add_old_iv_candidates (struct ivopts_data *data, struct iv *iv) | |
1693 | { | |
1694 | tree phi, def; | |
1695 | struct iv_cand *cand; | |
1696 | ||
1697 | add_candidate (data, iv->base, iv->step, true, NULL); | |
1698 | ||
1699 | /* The same, but with initial value zero. */ | |
1700 | add_candidate (data, | |
5212068f | 1701 | build_int_cst (TREE_TYPE (iv->base), 0), |
8b11a64c ZD |
1702 | iv->step, true, NULL); |
1703 | ||
1704 | phi = SSA_NAME_DEF_STMT (iv->ssa_name); | |
1705 | if (TREE_CODE (phi) == PHI_NODE) | |
1706 | { | |
1707 | /* Additionally record the possibility of leaving the original iv | |
1708 | untouched. */ | |
1709 | def = PHI_ARG_DEF_FROM_EDGE (phi, loop_latch_edge (data->current_loop)); | |
1710 | cand = add_candidate_1 (data, | |
1711 | iv->base, iv->step, true, IP_ORIGINAL, NULL, | |
1712 | SSA_NAME_DEF_STMT (def)); | |
1713 | cand->var_before = iv->ssa_name; | |
1714 | cand->var_after = def; | |
1715 | } | |
1716 | } | |
1717 | ||
1718 | /* Adds candidates based on the old induction variables. */ | |
1719 | ||
1720 | static void | |
1721 | add_old_ivs_candidates (struct ivopts_data *data) | |
1722 | { | |
1723 | unsigned i; | |
1724 | struct iv *iv; | |
87c476a2 | 1725 | bitmap_iterator bi; |
8b11a64c | 1726 | |
87c476a2 | 1727 | EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi) |
8b11a64c ZD |
1728 | { |
1729 | iv = ver_info (data, i)->iv; | |
1730 | if (iv && iv->biv_p && !zero_p (iv->step)) | |
1731 | add_old_iv_candidates (data, iv); | |
87c476a2 | 1732 | } |
8b11a64c ZD |
1733 | } |
1734 | ||
1735 | /* Adds candidates based on the value of the induction variable IV and USE. */ | |
1736 | ||
1737 | static void | |
1738 | add_iv_value_candidates (struct ivopts_data *data, | |
1739 | struct iv *iv, struct iv_use *use) | |
1740 | { | |
1741 | add_candidate (data, iv->base, iv->step, false, use); | |
1742 | ||
1743 | /* The same, but with initial value zero. */ | |
5212068f | 1744 | add_candidate (data, build_int_cst (TREE_TYPE (iv->base), 0), |
8b11a64c ZD |
1745 | iv->step, false, use); |
1746 | } | |
1747 | ||
1748 | /* Adds candidates based on the address IV and USE. */ | |
1749 | ||
1750 | static void | |
1751 | add_address_candidates (struct ivopts_data *data, | |
1752 | struct iv *iv, struct iv_use *use) | |
1753 | { | |
1754 | tree base, abase, tmp, *act; | |
1755 | ||
1756 | /* First, the trivial choices. */ | |
1757 | add_iv_value_candidates (data, iv, use); | |
1758 | ||
1759 | /* Second, try removing the COMPONENT_REFs. */ | |
1760 | if (TREE_CODE (iv->base) == ADDR_EXPR) | |
1761 | { | |
1762 | base = TREE_OPERAND (iv->base, 0); | |
1763 | while (TREE_CODE (base) == COMPONENT_REF | |
1764 | || (TREE_CODE (base) == ARRAY_REF | |
1765 | && TREE_CODE (TREE_OPERAND (base, 1)) == INTEGER_CST)) | |
1766 | base = TREE_OPERAND (base, 0); | |
1767 | ||
1768 | if (base != TREE_OPERAND (iv->base, 0)) | |
1769 | { | |
be35cf60 ZD |
1770 | gcc_assert (TREE_CODE (base) != ALIGN_INDIRECT_REF); |
1771 | gcc_assert (TREE_CODE (base) != MISALIGNED_INDIRECT_REF); | |
1772 | ||
1773 | if (TREE_CODE (base) == INDIRECT_REF) | |
8b11a64c ZD |
1774 | base = TREE_OPERAND (base, 0); |
1775 | else | |
1776 | base = build_addr (base); | |
1777 | add_candidate (data, base, iv->step, false, use); | |
1778 | } | |
1779 | } | |
1780 | ||
1781 | /* Third, try removing the constant offset. */ | |
1782 | abase = iv->base; | |
1783 | while (TREE_CODE (abase) == PLUS_EXPR | |
1784 | && TREE_CODE (TREE_OPERAND (abase, 1)) != INTEGER_CST) | |
1785 | abase = TREE_OPERAND (abase, 0); | |
1786 | /* We found the offset, so make the copy of the non-shared part and | |
1787 | remove it. */ | |
1788 | if (TREE_CODE (abase) == PLUS_EXPR) | |
1789 | { | |
1790 | tmp = iv->base; | |
1791 | act = &base; | |
1792 | ||
1793 | for (tmp = iv->base; tmp != abase; tmp = TREE_OPERAND (tmp, 0)) | |
1794 | { | |
1795 | *act = build2 (PLUS_EXPR, TREE_TYPE (tmp), | |
1796 | NULL_TREE, TREE_OPERAND (tmp, 1)); | |
1797 | act = &TREE_OPERAND (*act, 0); | |
1798 | } | |
1799 | *act = TREE_OPERAND (tmp, 0); | |
1800 | ||
1801 | add_candidate (data, base, iv->step, false, use); | |
1802 | } | |
1803 | } | |
1804 | ||
1805 | /* Possibly adds pseudocandidate for replacing the final value of USE by | |
1806 | a direct computation. */ | |
1807 | ||
1808 | static void | |
1809 | add_iv_outer_candidates (struct ivopts_data *data, struct iv_use *use) | |
1810 | { | |
1811 | struct tree_niter_desc *niter; | |
1812 | struct loop *loop = data->current_loop; | |
1813 | ||
1814 | /* We must know where we exit the loop and how many times does it roll. */ | |
1815 | if (!single_dom_exit (loop)) | |
1816 | return; | |
1817 | ||
1818 | niter = &loop_data (loop)->niter; | |
1819 | if (!niter->niter | |
1820 | || !operand_equal_p (niter->assumptions, boolean_true_node, 0) | |
1821 | || !operand_equal_p (niter->may_be_zero, boolean_false_node, 0)) | |
1822 | return; | |
1823 | ||
1824 | add_candidate_1 (data, NULL, NULL, false, IP_NORMAL, use, NULL_TREE); | |
1825 | } | |
1826 | ||
1827 | /* Adds candidates based on the uses. */ | |
1828 | ||
1829 | static void | |
1830 | add_derived_ivs_candidates (struct ivopts_data *data) | |
1831 | { | |
1832 | unsigned i; | |
1833 | ||
1834 | for (i = 0; i < n_iv_uses (data); i++) | |
1835 | { | |
1836 | struct iv_use *use = iv_use (data, i); | |
1837 | ||
1838 | if (!use) | |
1839 | continue; | |
1840 | ||
1841 | switch (use->type) | |
1842 | { | |
1843 | case USE_NONLINEAR_EXPR: | |
1844 | case USE_COMPARE: | |
1845 | /* Just add the ivs based on the value of the iv used here. */ | |
1846 | add_iv_value_candidates (data, use->iv, use); | |
1847 | break; | |
1848 | ||
1849 | case USE_OUTER: | |
1850 | add_iv_value_candidates (data, use->iv, use); | |
1851 | ||
1852 | /* Additionally, add the pseudocandidate for the possibility to | |
1853 | replace the final value by a direct computation. */ | |
1854 | add_iv_outer_candidates (data, use); | |
1855 | break; | |
1856 | ||
1857 | case USE_ADDRESS: | |
1858 | add_address_candidates (data, use->iv, use); | |
1859 | break; | |
1860 | ||
1861 | default: | |
1e128c5f | 1862 | gcc_unreachable (); |
8b11a64c ZD |
1863 | } |
1864 | } | |
1865 | } | |
1866 | ||
1867 | /* Finds the candidates for the induction variables. */ | |
1868 | ||
1869 | static void | |
1870 | find_iv_candidates (struct ivopts_data *data) | |
1871 | { | |
1872 | /* Add commonly used ivs. */ | |
1873 | add_standard_iv_candidates (data); | |
1874 | ||
1875 | /* Add old induction variables. */ | |
1876 | add_old_ivs_candidates (data); | |
1877 | ||
1878 | /* Add induction variables derived from uses. */ | |
1879 | add_derived_ivs_candidates (data); | |
1880 | } | |
1881 | ||
1882 | /* Allocates the data structure mapping the (use, candidate) pairs to costs. | |
1883 | If consider_all_candidates is true, we use a two-dimensional array, otherwise | |
1884 | we allocate a simple list to every use. */ | |
1885 | ||
1886 | static void | |
1887 | alloc_use_cost_map (struct ivopts_data *data) | |
1888 | { | |
1889 | unsigned i, n_imp = 0, size, j; | |
1890 | ||
1891 | if (!data->consider_all_candidates) | |
1892 | { | |
1893 | for (i = 0; i < n_iv_cands (data); i++) | |
1894 | { | |
1895 | struct iv_cand *cand = iv_cand (data, i); | |
1896 | if (cand->important) | |
1897 | n_imp++; | |
1898 | } | |
1899 | } | |
1900 | ||
1901 | for (i = 0; i < n_iv_uses (data); i++) | |
1902 | { | |
1903 | struct iv_use *use = iv_use (data, i); | |
87c476a2 | 1904 | bitmap_iterator bi; |
8b11a64c ZD |
1905 | |
1906 | if (data->consider_all_candidates) | |
1907 | { | |
1908 | size = n_iv_cands (data); | |
1909 | use->n_map_members = size; | |
1910 | } | |
1911 | else | |
1912 | { | |
1913 | size = n_imp; | |
87c476a2 ZD |
1914 | EXECUTE_IF_SET_IN_BITMAP (use->related_cands, 0, j, bi) |
1915 | { | |
1916 | size++; | |
1917 | } | |
8b11a64c ZD |
1918 | use->n_map_members = 0; |
1919 | } | |
1920 | ||
1921 | use->cost_map = xcalloc (size, sizeof (struct cost_pair)); | |
1922 | } | |
1923 | } | |
1924 | ||
1925 | /* Sets cost of (USE, CANDIDATE) pair to COST and record that it depends | |
1926 | on invariants DEPENDS_ON. */ | |
1927 | ||
1928 | static void | |
1929 | set_use_iv_cost (struct ivopts_data *data, | |
1930 | struct iv_use *use, struct iv_cand *cand, unsigned cost, | |
1931 | bitmap depends_on) | |
1932 | { | |
1933 | if (cost == INFTY | |
1934 | && depends_on) | |
1935 | { | |
1936 | BITMAP_XFREE (depends_on); | |
1937 | depends_on = NULL; | |
1938 | } | |
1939 | ||
1940 | if (data->consider_all_candidates) | |
1941 | { | |
1942 | use->cost_map[cand->id].cand = cand; | |
1943 | use->cost_map[cand->id].cost = cost; | |
1944 | use->cost_map[cand->id].depends_on = depends_on; | |
1945 | return; | |
1946 | } | |
1947 | ||
1948 | if (cost == INFTY) | |
1949 | return; | |
1950 | ||
1951 | use->cost_map[use->n_map_members].cand = cand; | |
1952 | use->cost_map[use->n_map_members].cost = cost; | |
1953 | use->cost_map[use->n_map_members].depends_on = depends_on; | |
1954 | use->n_map_members++; | |
1955 | } | |
1956 | ||
1957 | /* Gets cost of (USE, CANDIDATE) pair. Stores the bitmap of dependencies to | |
1958 | DEPENDS_ON. */ | |
1959 | ||
1960 | static unsigned | |
1961 | get_use_iv_cost (struct ivopts_data *data, | |
1962 | struct iv_use *use, struct iv_cand *cand, bitmap *depends_on) | |
1963 | { | |
1964 | unsigned i; | |
1965 | ||
1966 | if (!cand) | |
1967 | return INFTY; | |
1968 | ||
1969 | if (data->consider_all_candidates) | |
1970 | i = cand->id; | |
1971 | else | |
1972 | { | |
1973 | for (i = 0; i < use->n_map_members; i++) | |
1974 | if (use->cost_map[i].cand == cand) | |
1975 | break; | |
1976 | ||
1977 | if (i == use->n_map_members) | |
1978 | return INFTY; | |
1979 | } | |
1980 | ||
1981 | if (depends_on) | |
1982 | *depends_on = use->cost_map[i].depends_on; | |
1983 | return use->cost_map[i].cost; | |
1984 | } | |
1985 | ||
1986 | /* Returns estimate on cost of computing SEQ. */ | |
1987 | ||
1988 | static unsigned | |
1989 | seq_cost (rtx seq) | |
1990 | { | |
1991 | unsigned cost = 0; | |
1992 | rtx set; | |
1993 | ||
1994 | for (; seq; seq = NEXT_INSN (seq)) | |
1995 | { | |
1996 | set = single_set (seq); | |
1997 | if (set) | |
1998 | cost += rtx_cost (set, SET); | |
1999 | else | |
2000 | cost++; | |
2001 | } | |
2002 | ||
2003 | return cost; | |
2004 | } | |
2005 | ||
8679c649 JH |
2006 | /* Produce DECL_RTL for object obj so it looks like it is stored in memory. */ |
2007 | static rtx | |
2008 | produce_memory_decl_rtl (tree obj, int *regno) | |
2009 | { | |
2010 | rtx x; | |
2011 | if (!obj) | |
2012 | abort (); | |
2013 | if (TREE_STATIC (obj) || DECL_EXTERNAL (obj)) | |
2014 | { | |
2015 | const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (obj)); | |
2016 | x = gen_rtx_SYMBOL_REF (Pmode, name); | |
2017 | } | |
2018 | else | |
2019 | x = gen_raw_REG (Pmode, (*regno)++); | |
2020 | ||
2021 | return gen_rtx_MEM (DECL_MODE (obj), x); | |
2022 | } | |
2023 | ||
8b11a64c ZD |
2024 | /* Prepares decl_rtl for variables referred in *EXPR_P. Callback for |
2025 | walk_tree. DATA contains the actual fake register number. */ | |
2026 | ||
2027 | static tree | |
2028 | prepare_decl_rtl (tree *expr_p, int *ws, void *data) | |
2029 | { | |
2030 | tree obj = NULL_TREE; | |
2031 | rtx x = NULL_RTX; | |
2032 | int *regno = data; | |
2033 | ||
2034 | switch (TREE_CODE (*expr_p)) | |
2035 | { | |
8679c649 JH |
2036 | case ADDR_EXPR: |
2037 | for (expr_p = &TREE_OPERAND (*expr_p, 0); | |
2038 | (handled_component_p (*expr_p) | |
2039 | || TREE_CODE (*expr_p) == REALPART_EXPR | |
2040 | || TREE_CODE (*expr_p) == IMAGPART_EXPR); | |
2041 | expr_p = &TREE_OPERAND (*expr_p, 0)); | |
2042 | obj = *expr_p; | |
2043 | if (DECL_P (obj)) | |
2044 | x = produce_memory_decl_rtl (obj, regno); | |
2045 | break; | |
2046 | ||
8b11a64c ZD |
2047 | case SSA_NAME: |
2048 | *ws = 0; | |
2049 | obj = SSA_NAME_VAR (*expr_p); | |
2050 | if (!DECL_RTL_SET_P (obj)) | |
2051 | x = gen_raw_REG (DECL_MODE (obj), (*regno)++); | |
2052 | break; | |
2053 | ||
2054 | case VAR_DECL: | |
2055 | case PARM_DECL: | |
2056 | case RESULT_DECL: | |
2057 | *ws = 0; | |
2058 | obj = *expr_p; | |
2059 | ||
2060 | if (DECL_RTL_SET_P (obj)) | |
2061 | break; | |
2062 | ||
2063 | if (DECL_MODE (obj) == BLKmode) | |
8679c649 | 2064 | x = produce_memory_decl_rtl (obj, regno); |
8b11a64c ZD |
2065 | else |
2066 | x = gen_raw_REG (DECL_MODE (obj), (*regno)++); | |
2067 | ||
2068 | break; | |
2069 | ||
2070 | default: | |
2071 | break; | |
2072 | } | |
2073 | ||
2074 | if (x) | |
2075 | { | |
2076 | VARRAY_PUSH_GENERIC_PTR_NOGC (decl_rtl_to_reset, obj); | |
2077 | SET_DECL_RTL (obj, x); | |
2078 | } | |
2079 | ||
2080 | return NULL_TREE; | |
2081 | } | |
2082 | ||
2083 | /* Determines cost of the computation of EXPR. */ | |
2084 | ||
2085 | static unsigned | |
2086 | computation_cost (tree expr) | |
2087 | { | |
2088 | rtx seq, rslt; | |
2089 | tree type = TREE_TYPE (expr); | |
2090 | unsigned cost; | |
2091 | int regno = 0; | |
2092 | ||
2093 | walk_tree (&expr, prepare_decl_rtl, ®no, NULL); | |
2094 | start_sequence (); | |
2095 | rslt = expand_expr (expr, NULL_RTX, TYPE_MODE (type), EXPAND_NORMAL); | |
2096 | seq = get_insns (); | |
2097 | end_sequence (); | |
2098 | ||
2099 | cost = seq_cost (seq); | |
2100 | if (GET_CODE (rslt) == MEM) | |
2101 | cost += address_cost (XEXP (rslt, 0), TYPE_MODE (type)); | |
2102 | ||
2103 | return cost; | |
2104 | } | |
2105 | ||
2106 | /* Returns variable containing the value of candidate CAND at statement AT. */ | |
2107 | ||
2108 | static tree | |
2109 | var_at_stmt (struct loop *loop, struct iv_cand *cand, tree stmt) | |
2110 | { | |
2111 | if (stmt_after_increment (loop, cand, stmt)) | |
2112 | return cand->var_after; | |
2113 | else | |
2114 | return cand->var_before; | |
2115 | } | |
2116 | ||
2117 | /* Determines the expression by that USE is expressed from induction variable | |
2118 | CAND at statement AT in LOOP. */ | |
2119 | ||
2120 | static tree | |
2121 | get_computation_at (struct loop *loop, | |
2122 | struct iv_use *use, struct iv_cand *cand, tree at) | |
2123 | { | |
2f4675b4 ZD |
2124 | tree ubase = use->iv->base; |
2125 | tree ustep = use->iv->step; | |
2126 | tree cbase = cand->iv->base; | |
2127 | tree cstep = cand->iv->step; | |
8b11a64c ZD |
2128 | tree utype = TREE_TYPE (ubase), ctype = TREE_TYPE (cbase); |
2129 | tree uutype; | |
2130 | tree expr, delta; | |
2131 | tree ratio; | |
2132 | unsigned HOST_WIDE_INT ustepi, cstepi; | |
2133 | HOST_WIDE_INT ratioi; | |
2134 | ||
2135 | if (TYPE_PRECISION (utype) > TYPE_PRECISION (ctype)) | |
2136 | { | |
2137 | /* We do not have a precision to express the values of use. */ | |
2138 | return NULL_TREE; | |
2139 | } | |
2140 | ||
2141 | expr = var_at_stmt (loop, cand, at); | |
2142 | ||
2143 | if (TREE_TYPE (expr) != ctype) | |
2144 | { | |
2145 | /* This may happen with the original ivs. */ | |
2146 | expr = fold_convert (ctype, expr); | |
2147 | } | |
2148 | ||
2149 | if (TYPE_UNSIGNED (utype)) | |
2150 | uutype = utype; | |
2151 | else | |
2152 | { | |
2153 | uutype = unsigned_type_for (utype); | |
2154 | ubase = fold_convert (uutype, ubase); | |
2155 | ustep = fold_convert (uutype, ustep); | |
2156 | } | |
2157 | ||
2158 | if (uutype != ctype) | |
2159 | { | |
2160 | expr = fold_convert (uutype, expr); | |
2161 | cbase = fold_convert (uutype, cbase); | |
2162 | cstep = fold_convert (uutype, cstep); | |
2163 | } | |
2164 | ||
2165 | if (!cst_and_fits_in_hwi (cstep) | |
2166 | || !cst_and_fits_in_hwi (ustep)) | |
2167 | return NULL_TREE; | |
2168 | ||
2169 | ustepi = int_cst_value (ustep); | |
2170 | cstepi = int_cst_value (cstep); | |
2171 | ||
2172 | if (!divide (TYPE_PRECISION (uutype), ustepi, cstepi, &ratioi)) | |
2173 | { | |
2174 | /* TODO maybe consider case when ustep divides cstep and the ratio is | |
2175 | a power of 2 (so that the division is fast to execute)? We would | |
2176 | need to be much more careful with overflows etc. then. */ | |
2177 | return NULL_TREE; | |
2178 | } | |
2179 | ||
2180 | /* We may need to shift the value if we are after the increment. */ | |
2181 | if (stmt_after_increment (loop, cand, at)) | |
2182 | cbase = fold (build2 (PLUS_EXPR, uutype, cbase, cstep)); | |
2183 | ||
2184 | /* use = ubase + ratio * (var - cbase). If either cbase is a constant | |
2185 | or |ratio| == 1, it is better to handle this like | |
2186 | ||
2187 | ubase - ratio * cbase + ratio * var. */ | |
2188 | ||
2189 | if (ratioi == 1) | |
2190 | { | |
2191 | delta = fold (build2 (MINUS_EXPR, uutype, ubase, cbase)); | |
2192 | expr = fold (build2 (PLUS_EXPR, uutype, expr, delta)); | |
2193 | } | |
2194 | else if (ratioi == -1) | |
2195 | { | |
2196 | delta = fold (build2 (PLUS_EXPR, uutype, ubase, cbase)); | |
2197 | expr = fold (build2 (MINUS_EXPR, uutype, delta, expr)); | |
2198 | } | |
2199 | else if (TREE_CODE (cbase) == INTEGER_CST) | |
2200 | { | |
2201 | ratio = build_int_cst_type (uutype, ratioi); | |
2202 | delta = fold (build2 (MULT_EXPR, uutype, ratio, cbase)); | |
2203 | delta = fold (build2 (MINUS_EXPR, uutype, ubase, delta)); | |
2204 | expr = fold (build2 (MULT_EXPR, uutype, ratio, expr)); | |
2205 | expr = fold (build2 (PLUS_EXPR, uutype, delta, expr)); | |
2206 | } | |
2207 | else | |
2208 | { | |
2209 | expr = fold (build2 (MINUS_EXPR, uutype, expr, cbase)); | |
2210 | ratio = build_int_cst_type (uutype, ratioi); | |
2211 | expr = fold (build2 (MULT_EXPR, uutype, ratio, expr)); | |
2212 | expr = fold (build2 (PLUS_EXPR, uutype, ubase, expr)); | |
2213 | } | |
2214 | ||
2215 | return fold_convert (utype, expr); | |
2216 | } | |
2217 | ||
2218 | /* Determines the expression by that USE is expressed from induction variable | |
2219 | CAND in LOOP. */ | |
2220 | ||
2221 | static tree | |
2222 | get_computation (struct loop *loop, struct iv_use *use, struct iv_cand *cand) | |
2223 | { | |
2224 | return get_computation_at (loop, use, cand, use->stmt); | |
2225 | } | |
2226 | ||
2227 | /* Strips constant offsets from EXPR and adds them to OFFSET. */ | |
2228 | ||
2229 | static void | |
2230 | strip_offset (tree *expr, unsigned HOST_WIDE_INT *offset) | |
2231 | { | |
2232 | tree op0, op1; | |
2233 | enum tree_code code; | |
2234 | ||
2235 | while (1) | |
2236 | { | |
2237 | if (cst_and_fits_in_hwi (*expr)) | |
2238 | { | |
2239 | *offset += int_cst_value (*expr); | |
2240 | *expr = integer_zero_node; | |
2241 | return; | |
2242 | } | |
2243 | ||
2244 | code = TREE_CODE (*expr); | |
2245 | ||
2246 | if (code != PLUS_EXPR && code != MINUS_EXPR) | |
2247 | return; | |
2248 | ||
2249 | op0 = TREE_OPERAND (*expr, 0); | |
2250 | op1 = TREE_OPERAND (*expr, 1); | |
2251 | ||
2252 | if (cst_and_fits_in_hwi (op1)) | |
2253 | { | |
2254 | if (code == PLUS_EXPR) | |
2255 | *offset += int_cst_value (op1); | |
2256 | else | |
2257 | *offset -= int_cst_value (op1); | |
2258 | ||
2259 | *expr = op0; | |
2260 | continue; | |
2261 | } | |
2262 | ||
2263 | if (code != PLUS_EXPR) | |
2264 | return; | |
2265 | ||
2266 | if (!cst_and_fits_in_hwi (op0)) | |
2267 | return; | |
2268 | ||
2269 | *offset += int_cst_value (op0); | |
2270 | *expr = op1; | |
2271 | } | |
2272 | } | |
2273 | ||
2274 | /* Returns cost of addition in MODE. */ | |
2275 | ||
2276 | static unsigned | |
2277 | add_cost (enum machine_mode mode) | |
2278 | { | |
2279 | static unsigned costs[NUM_MACHINE_MODES]; | |
2280 | rtx seq; | |
2281 | unsigned cost; | |
2282 | ||
2283 | if (costs[mode]) | |
2284 | return costs[mode]; | |
2285 | ||
2286 | start_sequence (); | |
2287 | force_operand (gen_rtx_fmt_ee (PLUS, mode, | |
2288 | gen_raw_REG (mode, FIRST_PSEUDO_REGISTER), | |
2289 | gen_raw_REG (mode, FIRST_PSEUDO_REGISTER + 1)), | |
2290 | NULL_RTX); | |
2291 | seq = get_insns (); | |
2292 | end_sequence (); | |
2293 | ||
2294 | cost = seq_cost (seq); | |
2295 | if (!cost) | |
2296 | cost = 1; | |
2297 | ||
2298 | costs[mode] = cost; | |
2299 | ||
2300 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2301 | fprintf (dump_file, "Addition in %s costs %d\n", | |
2302 | GET_MODE_NAME (mode), cost); | |
2303 | return cost; | |
2304 | } | |
2305 | ||
2306 | /* Entry in a hashtable of already known costs for multiplication. */ | |
2307 | struct mbc_entry | |
2308 | { | |
2309 | HOST_WIDE_INT cst; /* The constant to multiply by. */ | |
2310 | enum machine_mode mode; /* In mode. */ | |
2311 | unsigned cost; /* The cost. */ | |
2312 | }; | |
2313 | ||
2314 | /* Counts hash value for the ENTRY. */ | |
2315 | ||
2316 | static hashval_t | |
2317 | mbc_entry_hash (const void *entry) | |
2318 | { | |
2319 | const struct mbc_entry *e = entry; | |
2320 | ||
2321 | return 57 * (hashval_t) e->mode + (hashval_t) (e->cst % 877); | |
2322 | } | |
2323 | ||
2324 | /* Compares the hash table entries ENTRY1 and ENTRY2. */ | |
2325 | ||
2326 | static int | |
2327 | mbc_entry_eq (const void *entry1, const void *entry2) | |
2328 | { | |
2329 | const struct mbc_entry *e1 = entry1; | |
2330 | const struct mbc_entry *e2 = entry2; | |
2331 | ||
2332 | return (e1->mode == e2->mode | |
2333 | && e1->cst == e2->cst); | |
2334 | } | |
2335 | ||
2336 | /* Returns cost of multiplication by constant CST in MODE. */ | |
2337 | ||
2338 | static unsigned | |
2339 | multiply_by_cost (HOST_WIDE_INT cst, enum machine_mode mode) | |
2340 | { | |
2341 | static htab_t costs; | |
2342 | struct mbc_entry **cached, act; | |
2343 | rtx seq; | |
2344 | unsigned cost; | |
2345 | ||
2346 | if (!costs) | |
2347 | costs = htab_create (100, mbc_entry_hash, mbc_entry_eq, free); | |
2348 | ||
2349 | act.mode = mode; | |
2350 | act.cst = cst; | |
2351 | cached = (struct mbc_entry **) htab_find_slot (costs, &act, INSERT); | |
2352 | if (*cached) | |
2353 | return (*cached)->cost; | |
2354 | ||
2355 | *cached = xmalloc (sizeof (struct mbc_entry)); | |
2356 | (*cached)->mode = mode; | |
2357 | (*cached)->cst = cst; | |
2358 | ||
2359 | start_sequence (); | |
2360 | expand_mult (mode, gen_raw_REG (mode, FIRST_PSEUDO_REGISTER), GEN_INT (cst), | |
2361 | NULL_RTX, 0); | |
2362 | seq = get_insns (); | |
2363 | end_sequence (); | |
2364 | ||
2365 | cost = seq_cost (seq); | |
2366 | ||
2367 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2368 | fprintf (dump_file, "Multiplication by %d in %s costs %d\n", | |
2369 | (int) cst, GET_MODE_NAME (mode), cost); | |
2370 | ||
2371 | (*cached)->cost = cost; | |
2372 | ||
2373 | return cost; | |
2374 | } | |
2375 | ||
2376 | /* Returns cost of address in shape symbol + var + OFFSET + RATIO * index. | |
2377 | If SYMBOL_PRESENT is false, symbol is omitted. If VAR_PRESENT is false, | |
2378 | variable is omitted. The created memory accesses MODE. | |
2379 | ||
2380 | TODO -- there must be some better way. This all is quite crude. */ | |
2381 | ||
2382 | static unsigned | |
2383 | get_address_cost (bool symbol_present, bool var_present, | |
2384 | unsigned HOST_WIDE_INT offset, HOST_WIDE_INT ratio) | |
2385 | { | |
2386 | #define MAX_RATIO 128 | |
2387 | static sbitmap valid_mult; | |
2388 | static HOST_WIDE_INT rat, off; | |
2389 | static HOST_WIDE_INT min_offset, max_offset; | |
2390 | static unsigned costs[2][2][2][2]; | |
2391 | unsigned cost, acost; | |
2392 | rtx seq, addr, base; | |
2393 | bool offset_p, ratio_p; | |
2394 | rtx reg1; | |
2395 | HOST_WIDE_INT s_offset; | |
2396 | unsigned HOST_WIDE_INT mask; | |
2397 | unsigned bits; | |
2398 | ||
2399 | if (!valid_mult) | |
2400 | { | |
2401 | HOST_WIDE_INT i; | |
2402 | ||
2403 | reg1 = gen_raw_REG (Pmode, FIRST_PSEUDO_REGISTER); | |
2404 | ||
2405 | addr = gen_rtx_fmt_ee (PLUS, Pmode, reg1, NULL_RTX); | |
2406 | for (i = 1; i <= 1 << 20; i <<= 1) | |
2407 | { | |
2408 | XEXP (addr, 1) = GEN_INT (i); | |
2409 | if (!memory_address_p (Pmode, addr)) | |
2410 | break; | |
2411 | } | |
2412 | max_offset = i >> 1; | |
2413 | off = max_offset; | |
2414 | ||
2415 | for (i = 1; i <= 1 << 20; i <<= 1) | |
2416 | { | |
2417 | XEXP (addr, 1) = GEN_INT (-i); | |
2418 | if (!memory_address_p (Pmode, addr)) | |
2419 | break; | |
2420 | } | |
2421 | min_offset = -(i >> 1); | |
2422 | ||
2423 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2424 | { | |
2425 | fprintf (dump_file, "get_address_cost:\n"); | |
2426 | fprintf (dump_file, " min offset %d\n", (int) min_offset); | |
2427 | fprintf (dump_file, " max offset %d\n", (int) max_offset); | |
2428 | } | |
2429 | ||
2430 | valid_mult = sbitmap_alloc (2 * MAX_RATIO + 1); | |
2431 | sbitmap_zero (valid_mult); | |
2432 | rat = 1; | |
2433 | addr = gen_rtx_fmt_ee (MULT, Pmode, reg1, NULL_RTX); | |
2434 | for (i = -MAX_RATIO; i <= MAX_RATIO; i++) | |
2435 | { | |
2436 | XEXP (addr, 1) = GEN_INT (i); | |
2437 | if (memory_address_p (Pmode, addr)) | |
2438 | { | |
2439 | SET_BIT (valid_mult, i + MAX_RATIO); | |
2440 | rat = i; | |
2441 | } | |
2442 | } | |
2443 | ||
2444 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2445 | { | |
2446 | fprintf (dump_file, " allowed multipliers:"); | |
2447 | for (i = -MAX_RATIO; i <= MAX_RATIO; i++) | |
2448 | if (TEST_BIT (valid_mult, i + MAX_RATIO)) | |
2449 | fprintf (dump_file, " %d", (int) i); | |
2450 | fprintf (dump_file, "\n"); | |
2451 | fprintf (dump_file, "\n"); | |
2452 | } | |
2453 | } | |
2454 | ||
2455 | bits = GET_MODE_BITSIZE (Pmode); | |
2456 | mask = ~(~(unsigned HOST_WIDE_INT) 0 << (bits - 1) << 1); | |
2457 | offset &= mask; | |
2458 | if ((offset >> (bits - 1) & 1)) | |
2459 | offset |= ~mask; | |
2460 | s_offset = offset; | |
2461 | ||
2462 | cost = 0; | |
2463 | offset_p = (min_offset <= s_offset && s_offset <= max_offset); | |
2464 | ratio_p = (ratio != 1 | |
2465 | && -MAX_RATIO <= ratio && ratio <= MAX_RATIO | |
2466 | && TEST_BIT (valid_mult, ratio + MAX_RATIO)); | |
2467 | ||
2468 | if (ratio != 1 && !ratio_p) | |
2469 | cost += multiply_by_cost (ratio, Pmode); | |
2470 | ||
2471 | if (s_offset && !offset_p && !symbol_present) | |
2472 | { | |
2473 | cost += add_cost (Pmode); | |
2474 | var_present = true; | |
2475 | } | |
2476 | ||
2477 | acost = costs[symbol_present][var_present][offset_p][ratio_p]; | |
2478 | if (!acost) | |
2479 | { | |
2480 | acost = 0; | |
2481 | ||
2482 | addr = gen_raw_REG (Pmode, FIRST_PSEUDO_REGISTER); | |
2483 | reg1 = gen_raw_REG (Pmode, FIRST_PSEUDO_REGISTER + 1); | |
2484 | if (ratio_p) | |
2485 | addr = gen_rtx_fmt_ee (MULT, Pmode, addr, GEN_INT (rat)); | |
2486 | ||
2487 | if (symbol_present) | |
2488 | { | |
2489 | base = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup ("")); | |
2490 | if (offset_p) | |
2491 | base = gen_rtx_fmt_e (CONST, Pmode, | |
2492 | gen_rtx_fmt_ee (PLUS, Pmode, | |
2493 | base, | |
2494 | GEN_INT (off))); | |
2495 | if (var_present) | |
2496 | base = gen_rtx_fmt_ee (PLUS, Pmode, reg1, base); | |
2497 | } | |
2498 | ||
2499 | else if (var_present) | |
2500 | { | |
2501 | base = reg1; | |
2502 | if (offset_p) | |
2503 | base = gen_rtx_fmt_ee (PLUS, Pmode, base, GEN_INT (off)); | |
2504 | } | |
2505 | else if (offset_p) | |
2506 | base = GEN_INT (off); | |
2507 | else | |
2508 | base = NULL_RTX; | |
2509 | ||
2510 | if (base) | |
2511 | addr = gen_rtx_fmt_ee (PLUS, Pmode, base, addr); | |
2512 | ||
2513 | start_sequence (); | |
2514 | addr = memory_address (Pmode, addr); | |
2515 | seq = get_insns (); | |
2516 | end_sequence (); | |
2517 | ||
2518 | acost = seq_cost (seq); | |
2519 | acost += address_cost (addr, Pmode); | |
2520 | ||
2521 | if (!acost) | |
2522 | acost = 1; | |
2523 | costs[symbol_present][var_present][offset_p][ratio_p] = acost; | |
2524 | } | |
2525 | ||
2526 | return cost + acost; | |
2527 | } | |
2528 | ||
2529 | /* Records invariants in *EXPR_P. Callback for walk_tree. DATA contains | |
2530 | the bitmap to that we should store it. */ | |
2531 | ||
2532 | static struct ivopts_data *fd_ivopts_data; | |
2533 | static tree | |
2534 | find_depends (tree *expr_p, int *ws ATTRIBUTE_UNUSED, void *data) | |
2535 | { | |
2536 | bitmap *depends_on = data; | |
2537 | struct version_info *info; | |
2538 | ||
2539 | if (TREE_CODE (*expr_p) != SSA_NAME) | |
2540 | return NULL_TREE; | |
2541 | info = name_info (fd_ivopts_data, *expr_p); | |
2542 | ||
2543 | if (!info->inv_id || info->has_nonlin_use) | |
2544 | return NULL_TREE; | |
2545 | ||
2546 | if (!*depends_on) | |
2547 | *depends_on = BITMAP_XMALLOC (); | |
2548 | bitmap_set_bit (*depends_on, info->inv_id); | |
2549 | ||
2550 | return NULL_TREE; | |
2551 | } | |
2552 | ||
2553 | /* Estimates cost of forcing EXPR into variable. DEPENDS_ON is a set of the | |
2554 | invariants the computation depends on. */ | |
2555 | ||
2556 | static unsigned | |
2557 | force_var_cost (struct ivopts_data *data, | |
2558 | tree expr, bitmap *depends_on) | |
2559 | { | |
2560 | static bool costs_initialized = false; | |
2561 | static unsigned integer_cost; | |
2562 | static unsigned symbol_cost; | |
2563 | static unsigned address_cost; | |
2564 | ||
2565 | if (!costs_initialized) | |
2566 | { | |
2567 | tree var = create_tmp_var_raw (integer_type_node, "test_var"); | |
2568 | rtx x = gen_rtx_MEM (DECL_MODE (var), | |
2569 | gen_rtx_SYMBOL_REF (Pmode, "test_var")); | |
2570 | tree addr; | |
2571 | tree type = build_pointer_type (integer_type_node); | |
2572 | ||
2573 | integer_cost = computation_cost (build_int_cst_type (integer_type_node, | |
2574 | 2000)); | |
2575 | ||
2576 | SET_DECL_RTL (var, x); | |
2577 | TREE_STATIC (var) = 1; | |
2578 | addr = build1 (ADDR_EXPR, type, var); | |
2579 | symbol_cost = computation_cost (addr) + 1; | |
2580 | ||
2581 | address_cost | |
2582 | = computation_cost (build2 (PLUS_EXPR, type, | |
2583 | addr, | |
2584 | build_int_cst_type (type, 2000))) + 1; | |
2585 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2586 | { | |
2587 | fprintf (dump_file, "force_var_cost:\n"); | |
2588 | fprintf (dump_file, " integer %d\n", (int) integer_cost); | |
2589 | fprintf (dump_file, " symbol %d\n", (int) symbol_cost); | |
2590 | fprintf (dump_file, " address %d\n", (int) address_cost); | |
2591 | fprintf (dump_file, " other %d\n", (int) target_spill_cost); | |
2592 | fprintf (dump_file, "\n"); | |
2593 | } | |
2594 | ||
2595 | costs_initialized = true; | |
2596 | } | |
2597 | ||
2598 | if (depends_on) | |
2599 | { | |
2600 | fd_ivopts_data = data; | |
2601 | walk_tree (&expr, find_depends, depends_on, NULL); | |
2602 | } | |
2603 | ||
2604 | if (SSA_VAR_P (expr)) | |
2605 | return 0; | |
2606 | ||
2607 | if (TREE_INVARIANT (expr)) | |
2608 | { | |
2609 | if (TREE_CODE (expr) == INTEGER_CST) | |
2610 | return integer_cost; | |
2611 | ||
2612 | if (TREE_CODE (expr) == ADDR_EXPR) | |
2613 | { | |
2614 | tree obj = TREE_OPERAND (expr, 0); | |
2615 | ||
2616 | if (TREE_CODE (obj) == VAR_DECL | |
2617 | || TREE_CODE (obj) == PARM_DECL | |
2618 | || TREE_CODE (obj) == RESULT_DECL) | |
2619 | return symbol_cost; | |
2620 | } | |
2621 | ||
2622 | return address_cost; | |
2623 | } | |
2624 | ||
2625 | /* Just an arbitrary value, FIXME. */ | |
2626 | return target_spill_cost; | |
2627 | } | |
2628 | ||
8b11a64c ZD |
2629 | /* Estimates cost of expressing address ADDR as var + symbol + offset. The |
2630 | value of offset is added to OFFSET, SYMBOL_PRESENT and VAR_PRESENT are set | |
2631 | to false if the corresponding part is missing. DEPENDS_ON is a set of the | |
2632 | invariants the computation depends on. */ | |
2633 | ||
2634 | static unsigned | |
2635 | split_address_cost (struct ivopts_data *data, | |
2636 | tree addr, bool *symbol_present, bool *var_present, | |
2637 | unsigned HOST_WIDE_INT *offset, bitmap *depends_on) | |
2638 | { | |
2f4675b4 ZD |
2639 | tree core; |
2640 | HOST_WIDE_INT bitsize; | |
2641 | HOST_WIDE_INT bitpos; | |
2642 | tree toffset; | |
2643 | enum machine_mode mode; | |
2644 | int unsignedp, volatilep; | |
2645 | ||
2646 | core = get_inner_reference (addr, &bitsize, &bitpos, &toffset, &mode, | |
2647 | &unsignedp, &volatilep); | |
8b11a64c | 2648 | |
2f4675b4 ZD |
2649 | if (toffset != 0 |
2650 | || bitpos % BITS_PER_UNIT != 0 | |
2651 | || TREE_CODE (core) != VAR_DECL) | |
8b11a64c ZD |
2652 | { |
2653 | *symbol_present = false; | |
2654 | *var_present = true; | |
2655 | fd_ivopts_data = data; | |
2656 | walk_tree (&addr, find_depends, depends_on, NULL); | |
2657 | return target_spill_cost; | |
2f4675b4 ZD |
2658 | } |
2659 | ||
2660 | *offset += bitpos / BITS_PER_UNIT; | |
8b11a64c ZD |
2661 | if (TREE_STATIC (core) |
2662 | || DECL_EXTERNAL (core)) | |
2663 | { | |
2664 | *symbol_present = true; | |
2665 | *var_present = false; | |
2666 | return 0; | |
2667 | } | |
2668 | ||
2669 | *symbol_present = false; | |
2670 | *var_present = true; | |
2671 | return 0; | |
2672 | } | |
2673 | ||
2674 | /* Estimates cost of expressing difference of addresses E1 - E2 as | |
2675 | var + symbol + offset. The value of offset is added to OFFSET, | |
2676 | SYMBOL_PRESENT and VAR_PRESENT are set to false if the corresponding | |
2677 | part is missing. DEPENDS_ON is a set of the invariants the computation | |
2678 | depends on. */ | |
2679 | ||
2680 | static unsigned | |
2681 | ptr_difference_cost (struct ivopts_data *data, | |
2682 | tree e1, tree e2, bool *symbol_present, bool *var_present, | |
2683 | unsigned HOST_WIDE_INT *offset, bitmap *depends_on) | |
2684 | { | |
2f4675b4 | 2685 | HOST_WIDE_INT diff = 0; |
8b11a64c ZD |
2686 | unsigned cost; |
2687 | ||
1e128c5f | 2688 | gcc_assert (TREE_CODE (e1) == ADDR_EXPR); |
8b11a64c ZD |
2689 | |
2690 | if (TREE_CODE (e2) == ADDR_EXPR | |
2691 | && ptr_difference_const (TREE_OPERAND (e1, 0), | |
2692 | TREE_OPERAND (e2, 0), &diff)) | |
2693 | { | |
2694 | *offset += diff; | |
2695 | *symbol_present = false; | |
2696 | *var_present = false; | |
2697 | return 0; | |
2698 | } | |
2699 | ||
2700 | if (e2 == integer_zero_node) | |
2701 | return split_address_cost (data, TREE_OPERAND (e1, 0), | |
2702 | symbol_present, var_present, offset, depends_on); | |
2703 | ||
2704 | *symbol_present = false; | |
2705 | *var_present = true; | |
2706 | ||
2707 | cost = force_var_cost (data, e1, depends_on); | |
2708 | cost += force_var_cost (data, e2, depends_on); | |
2709 | cost += add_cost (Pmode); | |
2710 | ||
2711 | return cost; | |
2712 | } | |
2713 | ||
2714 | /* Estimates cost of expressing difference E1 - E2 as | |
2715 | var + symbol + offset. The value of offset is added to OFFSET, | |
2716 | SYMBOL_PRESENT and VAR_PRESENT are set to false if the corresponding | |
2717 | part is missing. DEPENDS_ON is a set of the invariants the computation | |
2718 | depends on. */ | |
2719 | ||
2720 | static unsigned | |
2721 | difference_cost (struct ivopts_data *data, | |
2722 | tree e1, tree e2, bool *symbol_present, bool *var_present, | |
2723 | unsigned HOST_WIDE_INT *offset, bitmap *depends_on) | |
2724 | { | |
2725 | unsigned cost; | |
2726 | enum machine_mode mode = TYPE_MODE (TREE_TYPE (e1)); | |
2727 | ||
2728 | strip_offset (&e1, offset); | |
2729 | *offset = -*offset; | |
2730 | strip_offset (&e2, offset); | |
2731 | *offset = -*offset; | |
2732 | ||
2733 | if (TREE_CODE (e1) == ADDR_EXPR) | |
2734 | return ptr_difference_cost (data, e1, e2, symbol_present, var_present, offset, | |
2735 | depends_on); | |
2736 | *symbol_present = false; | |
2737 | ||
2738 | if (operand_equal_p (e1, e2, 0)) | |
2739 | { | |
2740 | *var_present = false; | |
2741 | return 0; | |
2742 | } | |
2743 | *var_present = true; | |
2744 | if (zero_p (e2)) | |
2745 | return force_var_cost (data, e1, depends_on); | |
2746 | ||
2747 | if (zero_p (e1)) | |
2748 | { | |
2749 | cost = force_var_cost (data, e2, depends_on); | |
2750 | cost += multiply_by_cost (-1, mode); | |
2751 | ||
2752 | return cost; | |
2753 | } | |
2754 | ||
2755 | cost = force_var_cost (data, e1, depends_on); | |
2756 | cost += force_var_cost (data, e2, depends_on); | |
2757 | cost += add_cost (mode); | |
2758 | ||
2759 | return cost; | |
2760 | } | |
2761 | ||
2762 | /* Determines the cost of the computation by that USE is expressed | |
2763 | from induction variable CAND. If ADDRESS_P is true, we just need | |
2764 | to create an address from it, otherwise we want to get it into | |
2765 | register. A set of invariants we depend on is stored in | |
2766 | DEPENDS_ON. AT is the statement at that the value is computed. */ | |
2767 | ||
2768 | static unsigned | |
2769 | get_computation_cost_at (struct ivopts_data *data, | |
2770 | struct iv_use *use, struct iv_cand *cand, | |
2771 | bool address_p, bitmap *depends_on, tree at) | |
2772 | { | |
2773 | tree ubase = use->iv->base, ustep = use->iv->step; | |
2774 | tree cbase, cstep; | |
2775 | tree utype = TREE_TYPE (ubase), ctype; | |
2776 | unsigned HOST_WIDE_INT ustepi, cstepi, offset = 0; | |
2777 | HOST_WIDE_INT ratio, aratio; | |
2778 | bool var_present, symbol_present; | |
2779 | unsigned cost = 0, n_sums; | |
2780 | ||
2781 | *depends_on = NULL; | |
2782 | ||
2783 | /* Only consider real candidates. */ | |
2784 | if (!cand->iv) | |
2785 | return INFTY; | |
2786 | ||
2787 | cbase = cand->iv->base; | |
2788 | cstep = cand->iv->step; | |
2789 | ctype = TREE_TYPE (cbase); | |
2790 | ||
2791 | if (TYPE_PRECISION (utype) > TYPE_PRECISION (ctype)) | |
2792 | { | |
2793 | /* We do not have a precision to express the values of use. */ | |
2794 | return INFTY; | |
2795 | } | |
2796 | ||
2797 | if (!cst_and_fits_in_hwi (ustep) | |
2798 | || !cst_and_fits_in_hwi (cstep)) | |
2799 | return INFTY; | |
2800 | ||
2801 | if (TREE_CODE (ubase) == INTEGER_CST | |
2802 | && !cst_and_fits_in_hwi (ubase)) | |
2803 | goto fallback; | |
2804 | ||
2805 | if (TREE_CODE (cbase) == INTEGER_CST | |
2806 | && !cst_and_fits_in_hwi (cbase)) | |
2807 | goto fallback; | |
2808 | ||
2809 | ustepi = int_cst_value (ustep); | |
2810 | cstepi = int_cst_value (cstep); | |
2811 | ||
2812 | if (TYPE_PRECISION (utype) != TYPE_PRECISION (ctype)) | |
2813 | { | |
2814 | /* TODO -- add direct handling of this case. */ | |
2815 | goto fallback; | |
2816 | } | |
2817 | ||
2818 | if (!divide (TYPE_PRECISION (utype), ustepi, cstepi, &ratio)) | |
2819 | return INFTY; | |
2820 | ||
2821 | /* use = ubase + ratio * (var - cbase). If either cbase is a constant | |
2822 | or ratio == 1, it is better to handle this like | |
2823 | ||
2824 | ubase - ratio * cbase + ratio * var | |
2825 | ||
2826 | (also holds in the case ratio == -1, TODO. */ | |
2827 | ||
2828 | if (TREE_CODE (cbase) == INTEGER_CST) | |
2829 | { | |
2830 | offset = - ratio * int_cst_value (cbase); | |
2831 | cost += difference_cost (data, | |
2832 | ubase, integer_zero_node, | |
2833 | &symbol_present, &var_present, &offset, | |
2834 | depends_on); | |
2835 | } | |
2836 | else if (ratio == 1) | |
2837 | { | |
2838 | cost += difference_cost (data, | |
2839 | ubase, cbase, | |
2840 | &symbol_present, &var_present, &offset, | |
2841 | depends_on); | |
2842 | } | |
2843 | else | |
2844 | { | |
2845 | cost += force_var_cost (data, cbase, depends_on); | |
2846 | cost += add_cost (TYPE_MODE (ctype)); | |
2847 | cost += difference_cost (data, | |
2848 | ubase, integer_zero_node, | |
2849 | &symbol_present, &var_present, &offset, | |
2850 | depends_on); | |
2851 | } | |
2852 | ||
2853 | /* If we are after the increment, the value of the candidate is higher by | |
2854 | one iteration. */ | |
2855 | if (stmt_after_increment (data->current_loop, cand, at)) | |
2856 | offset -= ratio * cstepi; | |
2857 | ||
2858 | /* Now the computation is in shape symbol + var1 + const + ratio * var2. | |
2859 | (symbol/var/const parts may be omitted). If we are looking for an address, | |
2860 | find the cost of addressing this. */ | |
2861 | if (address_p) | |
2862 | return get_address_cost (symbol_present, var_present, offset, ratio); | |
2863 | ||
2864 | /* Otherwise estimate the costs for computing the expression. */ | |
2865 | aratio = ratio > 0 ? ratio : -ratio; | |
2866 | if (!symbol_present && !var_present && !offset) | |
2867 | { | |
2868 | if (ratio != 1) | |
2869 | cost += multiply_by_cost (ratio, TYPE_MODE (ctype)); | |
2870 | ||
2871 | return cost; | |
2872 | } | |
2873 | ||
2874 | if (aratio != 1) | |
2875 | cost += multiply_by_cost (aratio, TYPE_MODE (ctype)); | |
2876 | ||
2877 | n_sums = 1; | |
2878 | if (var_present | |
2879 | /* Symbol + offset should be compile-time computable. */ | |
2880 | && (symbol_present || offset)) | |
2881 | n_sums++; | |
2882 | ||
2883 | return cost + n_sums * add_cost (TYPE_MODE (ctype)); | |
2884 | ||
2885 | fallback: | |
2886 | { | |
2887 | /* Just get the expression, expand it and measure the cost. */ | |
2888 | tree comp = get_computation_at (data->current_loop, use, cand, at); | |
2889 | ||
2890 | if (!comp) | |
2891 | return INFTY; | |
2892 | ||
2893 | if (address_p) | |
2894 | comp = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (comp)), comp); | |
2895 | ||
2896 | return computation_cost (comp); | |
2897 | } | |
2898 | } | |
2899 | ||
2900 | /* Determines the cost of the computation by that USE is expressed | |
2901 | from induction variable CAND. If ADDRESS_P is true, we just need | |
2902 | to create an address from it, otherwise we want to get it into | |
2903 | register. A set of invariants we depend on is stored in | |
2904 | DEPENDS_ON. */ | |
2905 | ||
2906 | static unsigned | |
2907 | get_computation_cost (struct ivopts_data *data, | |
2908 | struct iv_use *use, struct iv_cand *cand, | |
2909 | bool address_p, bitmap *depends_on) | |
2910 | { | |
2911 | return get_computation_cost_at (data, | |
2912 | use, cand, address_p, depends_on, use->stmt); | |
2913 | } | |
2914 | ||
2915 | /* Determines cost of basing replacement of USE on CAND in a generic | |
2916 | expression. */ | |
2917 | ||
2918 | static void | |
2919 | determine_use_iv_cost_generic (struct ivopts_data *data, | |
2920 | struct iv_use *use, struct iv_cand *cand) | |
2921 | { | |
2922 | bitmap depends_on; | |
2923 | unsigned cost = get_computation_cost (data, use, cand, false, &depends_on); | |
2924 | ||
2925 | set_use_iv_cost (data, use, cand, cost, depends_on); | |
2926 | } | |
2927 | ||
2928 | /* Determines cost of basing replacement of USE on CAND in an address. */ | |
2929 | ||
2930 | static void | |
2931 | determine_use_iv_cost_address (struct ivopts_data *data, | |
2932 | struct iv_use *use, struct iv_cand *cand) | |
2933 | { | |
2934 | bitmap depends_on; | |
2935 | unsigned cost = get_computation_cost (data, use, cand, true, &depends_on); | |
2936 | ||
2937 | set_use_iv_cost (data, use, cand, cost, depends_on); | |
2938 | } | |
2939 | ||
2940 | /* Computes value of induction variable IV in iteration NITER. */ | |
2941 | ||
2942 | static tree | |
2943 | iv_value (struct iv *iv, tree niter) | |
2944 | { | |
2945 | tree val; | |
2946 | tree type = TREE_TYPE (iv->base); | |
2947 | ||
2948 | niter = fold_convert (type, niter); | |
2f4675b4 | 2949 | val = fold (build2 (MULT_EXPR, type, iv->step, niter)); |
8b11a64c ZD |
2950 | |
2951 | return fold (build2 (PLUS_EXPR, type, iv->base, val)); | |
2952 | } | |
2953 | ||
2954 | /* Computes value of candidate CAND at position AT in iteration NITER. */ | |
2955 | ||
2956 | static tree | |
2957 | cand_value_at (struct loop *loop, struct iv_cand *cand, tree at, tree niter) | |
2958 | { | |
2959 | tree val = iv_value (cand->iv, niter); | |
2960 | tree type = TREE_TYPE (cand->iv->base); | |
2961 | ||
2962 | if (stmt_after_increment (loop, cand, at)) | |
2963 | val = fold (build2 (PLUS_EXPR, type, val, cand->iv->step)); | |
2964 | ||
2965 | return val; | |
2966 | } | |
2967 | ||
2968 | /* Check whether it is possible to express the condition in USE by comparison | |
2969 | of candidate CAND. If so, store the comparison code to COMPARE and the | |
2970 | value compared with to BOUND. */ | |
2971 | ||
2972 | static bool | |
2973 | may_eliminate_iv (struct loop *loop, | |
2974 | struct iv_use *use, struct iv_cand *cand, | |
2975 | enum tree_code *compare, tree *bound) | |
2976 | { | |
2977 | edge exit; | |
2978 | struct tree_niter_desc *niter, new_niter; | |
2979 | tree wider_type, type, base; | |
2980 | ||
2981 | /* For now just very primitive -- we work just for the single exit condition, | |
2982 | and are quite conservative about the possible overflows. TODO -- both of | |
2983 | these can be improved. */ | |
2984 | exit = single_dom_exit (loop); | |
2985 | if (!exit) | |
2986 | return false; | |
2987 | if (use->stmt != last_stmt (exit->src)) | |
2988 | return false; | |
2989 | ||
2990 | niter = &loop_data (loop)->niter; | |
2991 | if (!niter->niter | |
2992 | || !integer_nonzerop (niter->assumptions) | |
2993 | || !integer_zerop (niter->may_be_zero)) | |
2994 | return false; | |
2995 | ||
2996 | if (exit->flags & EDGE_TRUE_VALUE) | |
2997 | *compare = EQ_EXPR; | |
2998 | else | |
2999 | *compare = NE_EXPR; | |
3000 | ||
3001 | *bound = cand_value_at (loop, cand, use->stmt, niter->niter); | |
3002 | ||
3003 | /* Let us check there is not some problem with overflows, by checking that | |
3004 | the number of iterations is unchanged. */ | |
3005 | base = cand->iv->base; | |
3006 | type = TREE_TYPE (base); | |
3007 | if (stmt_after_increment (loop, cand, use->stmt)) | |
3008 | base = fold (build2 (PLUS_EXPR, type, base, cand->iv->step)); | |
3009 | ||
3010 | new_niter.niter = NULL_TREE; | |
3011 | number_of_iterations_cond (TREE_TYPE (cand->iv->base), base, | |
3012 | cand->iv->step, NE_EXPR, *bound, NULL_TREE, | |
3013 | &new_niter); | |
3014 | if (!new_niter.niter | |
3015 | || !integer_nonzerop (new_niter.assumptions) | |
3016 | || !integer_zerop (new_niter.may_be_zero)) | |
3017 | return false; | |
3018 | ||
3019 | wider_type = TREE_TYPE (new_niter.niter); | |
3020 | if (TYPE_PRECISION (wider_type) < TYPE_PRECISION (TREE_TYPE (niter->niter))) | |
3021 | wider_type = TREE_TYPE (niter->niter); | |
3022 | if (!operand_equal_p (fold_convert (wider_type, niter->niter), | |
3023 | fold_convert (wider_type, new_niter.niter), 0)) | |
3024 | return false; | |
3025 | ||
3026 | return true; | |
3027 | } | |
3028 | ||
3029 | /* Determines cost of basing replacement of USE on CAND in a condition. */ | |
3030 | ||
3031 | static void | |
3032 | determine_use_iv_cost_condition (struct ivopts_data *data, | |
3033 | struct iv_use *use, struct iv_cand *cand) | |
3034 | { | |
3035 | tree bound; | |
3036 | enum tree_code compare; | |
3037 | ||
3038 | /* Only consider real candidates. */ | |
3039 | if (!cand->iv) | |
3040 | { | |
3041 | set_use_iv_cost (data, use, cand, INFTY, NULL); | |
3042 | return; | |
3043 | } | |
3044 | ||
3045 | if (may_eliminate_iv (data->current_loop, use, cand, &compare, &bound)) | |
3046 | { | |
3047 | bitmap depends_on = NULL; | |
3048 | unsigned cost = force_var_cost (data, bound, &depends_on); | |
3049 | ||
3050 | set_use_iv_cost (data, use, cand, cost, depends_on); | |
3051 | return; | |
3052 | } | |
3053 | ||
3054 | /* The induction variable elimination failed; just express the original | |
3055 | giv. If it is compared with an invariant, note that we cannot get | |
3056 | rid of it. */ | |
3057 | if (TREE_CODE (*use->op_p) == SSA_NAME) | |
3058 | record_invariant (data, *use->op_p, true); | |
3059 | else | |
3060 | { | |
3061 | record_invariant (data, TREE_OPERAND (*use->op_p, 0), true); | |
3062 | record_invariant (data, TREE_OPERAND (*use->op_p, 1), true); | |
3063 | } | |
3064 | ||
3065 | determine_use_iv_cost_generic (data, use, cand); | |
3066 | } | |
3067 | ||
3068 | /* Checks whether it is possible to replace the final value of USE by | |
3069 | a direct computation. If so, the formula is stored to *VALUE. */ | |
3070 | ||
3071 | static bool | |
3072 | may_replace_final_value (struct loop *loop, struct iv_use *use, tree *value) | |
3073 | { | |
3074 | edge exit; | |
3075 | struct tree_niter_desc *niter; | |
3076 | ||
3077 | exit = single_dom_exit (loop); | |
3078 | if (!exit) | |
3079 | return false; | |
3080 | ||
1e128c5f GB |
3081 | gcc_assert (dominated_by_p (CDI_DOMINATORS, exit->src, |
3082 | bb_for_stmt (use->stmt))); | |
8b11a64c ZD |
3083 | |
3084 | niter = &loop_data (loop)->niter; | |
3085 | if (!niter->niter | |
3086 | || !operand_equal_p (niter->assumptions, boolean_true_node, 0) | |
3087 | || !operand_equal_p (niter->may_be_zero, boolean_false_node, 0)) | |
3088 | return false; | |
3089 | ||
3090 | *value = iv_value (use->iv, niter->niter); | |
3091 | ||
3092 | return true; | |
3093 | } | |
3094 | ||
3095 | /* Determines cost of replacing final value of USE using CAND. */ | |
3096 | ||
3097 | static void | |
3098 | determine_use_iv_cost_outer (struct ivopts_data *data, | |
3099 | struct iv_use *use, struct iv_cand *cand) | |
3100 | { | |
3101 | bitmap depends_on; | |
3102 | unsigned cost; | |
3103 | edge exit; | |
3104 | tree value; | |
3105 | struct loop *loop = data->current_loop; | |
3106 | ||
3107 | if (!cand->iv) | |
3108 | { | |
3109 | if (!may_replace_final_value (loop, use, &value)) | |
3110 | { | |
3111 | set_use_iv_cost (data, use, cand, INFTY, NULL); | |
3112 | return; | |
3113 | } | |
3114 | ||
3115 | depends_on = NULL; | |
3116 | cost = force_var_cost (data, value, &depends_on); | |
3117 | ||
3118 | cost /= AVG_LOOP_NITER (loop); | |
3119 | ||
3120 | set_use_iv_cost (data, use, cand, cost, depends_on); | |
3121 | return; | |
3122 | } | |
3123 | ||
3124 | exit = single_dom_exit (loop); | |
3125 | if (exit) | |
3126 | { | |
3127 | /* If there is just a single exit, we may use value of the candidate | |
3128 | after we take it to determine the value of use. */ | |
3129 | cost = get_computation_cost_at (data, use, cand, false, &depends_on, | |
3130 | last_stmt (exit->src)); | |
3131 | if (cost != INFTY) | |
3132 | cost /= AVG_LOOP_NITER (loop); | |
3133 | } | |
3134 | else | |
3135 | { | |
3136 | /* Otherwise we just need to compute the iv. */ | |
3137 | cost = get_computation_cost (data, use, cand, false, &depends_on); | |
3138 | } | |
3139 | ||
3140 | set_use_iv_cost (data, use, cand, cost, depends_on); | |
3141 | } | |
3142 | ||
3143 | /* Determines cost of basing replacement of USE on CAND. */ | |
3144 | ||
3145 | static void | |
3146 | determine_use_iv_cost (struct ivopts_data *data, | |
3147 | struct iv_use *use, struct iv_cand *cand) | |
3148 | { | |
3149 | switch (use->type) | |
3150 | { | |
3151 | case USE_NONLINEAR_EXPR: | |
3152 | determine_use_iv_cost_generic (data, use, cand); | |
3153 | break; | |
3154 | ||
3155 | case USE_OUTER: | |
3156 | determine_use_iv_cost_outer (data, use, cand); | |
3157 | break; | |
3158 | ||
3159 | case USE_ADDRESS: | |
3160 | determine_use_iv_cost_address (data, use, cand); | |
3161 | break; | |
3162 | ||
3163 | case USE_COMPARE: | |
3164 | determine_use_iv_cost_condition (data, use, cand); | |
3165 | break; | |
3166 | ||
3167 | default: | |
1e128c5f | 3168 | gcc_unreachable (); |
8b11a64c ZD |
3169 | } |
3170 | } | |
3171 | ||
3172 | /* Determines costs of basing the use of the iv on an iv candidate. */ | |
3173 | ||
3174 | static void | |
3175 | determine_use_iv_costs (struct ivopts_data *data) | |
3176 | { | |
3177 | unsigned i, j; | |
3178 | struct iv_use *use; | |
3179 | struct iv_cand *cand; | |
3180 | ||
3181 | data->consider_all_candidates = (n_iv_cands (data) | |
3182 | <= CONSIDER_ALL_CANDIDATES_BOUND); | |
3183 | ||
3184 | alloc_use_cost_map (data); | |
3185 | ||
3186 | if (!data->consider_all_candidates) | |
3187 | { | |
3188 | /* Add the important candidate entries. */ | |
3189 | for (j = 0; j < n_iv_cands (data); j++) | |
3190 | { | |
3191 | cand = iv_cand (data, j); | |
3192 | if (!cand->important) | |
3193 | continue; | |
3194 | for (i = 0; i < n_iv_uses (data); i++) | |
3195 | { | |
3196 | use = iv_use (data, i); | |
3197 | determine_use_iv_cost (data, use, cand); | |
3198 | } | |
3199 | } | |
3200 | } | |
3201 | ||
3202 | for (i = 0; i < n_iv_uses (data); i++) | |
3203 | { | |
3204 | use = iv_use (data, i); | |
3205 | ||
3206 | if (data->consider_all_candidates) | |
3207 | { | |
3208 | for (j = 0; j < n_iv_cands (data); j++) | |
3209 | { | |
3210 | cand = iv_cand (data, j); | |
3211 | determine_use_iv_cost (data, use, cand); | |
3212 | } | |
3213 | } | |
3214 | else | |
3215 | { | |
87c476a2 ZD |
3216 | bitmap_iterator bi; |
3217 | ||
3218 | EXECUTE_IF_SET_IN_BITMAP (use->related_cands, 0, j, bi) | |
8b11a64c ZD |
3219 | { |
3220 | cand = iv_cand (data, j); | |
3221 | if (!cand->important) | |
3222 | determine_use_iv_cost (data, use, cand); | |
87c476a2 | 3223 | } |
8b11a64c ZD |
3224 | } |
3225 | } | |
3226 | ||
3227 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3228 | { | |
3229 | fprintf (dump_file, "Use-candidate costs:\n"); | |
3230 | ||
3231 | for (i = 0; i < n_iv_uses (data); i++) | |
3232 | { | |
3233 | use = iv_use (data, i); | |
3234 | ||
3235 | fprintf (dump_file, "Use %d:\n", i); | |
3236 | fprintf (dump_file, " cand\tcost\tdepends on\n"); | |
3237 | for (j = 0; j < use->n_map_members; j++) | |
3238 | { | |
3239 | if (!use->cost_map[j].cand | |
3240 | || use->cost_map[j].cost == INFTY) | |
3241 | continue; | |
3242 | ||
3243 | fprintf (dump_file, " %d\t%d\t", | |
3244 | use->cost_map[j].cand->id, | |
3245 | use->cost_map[j].cost); | |
3246 | if (use->cost_map[j].depends_on) | |
3247 | bitmap_print (dump_file, | |
3248 | use->cost_map[j].depends_on, "",""); | |
3249 | fprintf (dump_file, "\n"); | |
3250 | } | |
3251 | ||
3252 | fprintf (dump_file, "\n"); | |
3253 | } | |
3254 | fprintf (dump_file, "\n"); | |
3255 | } | |
3256 | } | |
3257 | ||
3258 | /* Determines cost of the candidate CAND. */ | |
3259 | ||
3260 | static void | |
3261 | determine_iv_cost (struct ivopts_data *data, struct iv_cand *cand) | |
3262 | { | |
3263 | unsigned cost_base, cost_step; | |
3264 | tree base, last; | |
3265 | basic_block bb; | |
3266 | ||
3267 | if (!cand->iv) | |
3268 | { | |
3269 | cand->cost = 0; | |
3270 | return; | |
3271 | } | |
3272 | ||
3273 | /* There are two costs associated with the candidate -- its increment | |
3274 | and its initialization. The second is almost negligible for any loop | |
3275 | that rolls enough, so we take it just very little into account. */ | |
3276 | ||
3277 | base = cand->iv->base; | |
3278 | cost_base = force_var_cost (data, base, NULL); | |
3279 | cost_step = add_cost (TYPE_MODE (TREE_TYPE (base))); | |
3280 | ||
3281 | cand->cost = cost_step + cost_base / AVG_LOOP_NITER (current_loop); | |
3282 | ||
3283 | /* Prefer the original iv unless we may gain something by replacing it. */ | |
3284 | if (cand->pos == IP_ORIGINAL) | |
3285 | cand->cost--; | |
3286 | ||
3287 | /* Prefer not to insert statements into latch unless there are some | |
3288 | already (so that we do not create unnecessary jumps). */ | |
3289 | if (cand->pos == IP_END) | |
3290 | { | |
3291 | bb = ip_end_pos (data->current_loop); | |
3292 | last = last_stmt (bb); | |
3293 | ||
3294 | if (!last | |
3295 | || TREE_CODE (last) == LABEL_EXPR) | |
3296 | cand->cost++; | |
3297 | } | |
3298 | } | |
3299 | ||
3300 | /* Determines costs of computation of the candidates. */ | |
3301 | ||
3302 | static void | |
3303 | determine_iv_costs (struct ivopts_data *data) | |
3304 | { | |
3305 | unsigned i; | |
3306 | ||
3307 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3308 | { | |
3309 | fprintf (dump_file, "Candidate costs:\n"); | |
3310 | fprintf (dump_file, " cand\tcost\n"); | |
3311 | } | |
3312 | ||
3313 | for (i = 0; i < n_iv_cands (data); i++) | |
3314 | { | |
3315 | struct iv_cand *cand = iv_cand (data, i); | |
3316 | ||
3317 | determine_iv_cost (data, cand); | |
3318 | ||
3319 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3320 | fprintf (dump_file, " %d\t%d\n", i, cand->cost); | |
3321 | } | |
3322 | ||
3323 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3324 | fprintf (dump_file, "\n"); | |
3325 | } | |
3326 | ||
3327 | /* Calculates cost for having SIZE induction variables. */ | |
3328 | ||
3329 | static unsigned | |
3330 | ivopts_global_cost_for_size (struct ivopts_data *data, unsigned size) | |
3331 | { | |
3332 | return global_cost_for_size (size, | |
3333 | loop_data (data->current_loop)->regs_used, | |
3334 | n_iv_uses (data)); | |
3335 | } | |
3336 | ||
3337 | /* For each size of the induction variable set determine the penalty. */ | |
3338 | ||
3339 | static void | |
3340 | determine_set_costs (struct ivopts_data *data) | |
3341 | { | |
3342 | unsigned j, n; | |
3343 | tree phi, op; | |
3344 | struct loop *loop = data->current_loop; | |
87c476a2 | 3345 | bitmap_iterator bi; |
8b11a64c ZD |
3346 | |
3347 | /* We use the following model (definitely improvable, especially the | |
3348 | cost function -- TODO): | |
3349 | ||
3350 | We estimate the number of registers available (using MD data), name it A. | |
3351 | ||
3352 | We estimate the number of registers used by the loop, name it U. This | |
3353 | number is obtained as the number of loop phi nodes (not counting virtual | |
3354 | registers and bivs) + the number of variables from outside of the loop. | |
3355 | ||
3356 | We set a reserve R (free regs that are used for temporary computations, | |
3357 | etc.). For now the reserve is a constant 3. | |
3358 | ||
3359 | Let I be the number of induction variables. | |
3360 | ||
3361 | -- if U + I + R <= A, the cost is I * SMALL_COST (just not to encourage | |
3362 | make a lot of ivs without a reason). | |
3363 | -- if A - R < U + I <= A, the cost is I * PRES_COST | |
3364 | -- if U + I > A, the cost is I * PRES_COST and | |
3365 | number of uses * SPILL_COST * (U + I - A) / (U + I) is added. */ | |
3366 | ||
3367 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3368 | { | |
3369 | fprintf (dump_file, "Global costs:\n"); | |
3370 | fprintf (dump_file, " target_avail_regs %d\n", target_avail_regs); | |
3371 | fprintf (dump_file, " target_small_cost %d\n", target_small_cost); | |
3372 | fprintf (dump_file, " target_pres_cost %d\n", target_pres_cost); | |
3373 | fprintf (dump_file, " target_spill_cost %d\n", target_spill_cost); | |
3374 | } | |
3375 | ||
3376 | n = 0; | |
3377 | for (phi = phi_nodes (loop->header); phi; phi = TREE_CHAIN (phi)) | |
3378 | { | |
3379 | op = PHI_RESULT (phi); | |
3380 | ||
3381 | if (!is_gimple_reg (op)) | |
3382 | continue; | |
3383 | ||
3384 | if (get_iv (data, op)) | |
3385 | continue; | |
3386 | ||
3387 | n++; | |
3388 | } | |
3389 | ||
87c476a2 | 3390 | EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, j, bi) |
8b11a64c ZD |
3391 | { |
3392 | struct version_info *info = ver_info (data, j); | |
3393 | ||
3394 | if (info->inv_id && info->has_nonlin_use) | |
3395 | n++; | |
87c476a2 | 3396 | } |
8b11a64c ZD |
3397 | |
3398 | loop_data (loop)->regs_used = n; | |
3399 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3400 | fprintf (dump_file, " regs_used %d\n", n); | |
3401 | ||
3402 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3403 | { | |
3404 | fprintf (dump_file, " cost for size:\n"); | |
3405 | fprintf (dump_file, " ivs\tcost\n"); | |
3406 | for (j = 0; j <= 2 * target_avail_regs; j++) | |
3407 | fprintf (dump_file, " %d\t%d\n", j, | |
3408 | ivopts_global_cost_for_size (data, j)); | |
3409 | fprintf (dump_file, "\n"); | |
3410 | } | |
3411 | } | |
3412 | ||
3413 | /* Finds a best candidate for USE and stores it to CAND. The candidates are | |
3414 | taken from the set SOL and they may depend on invariants in the set INV. | |
3415 | The really used candidate and invariants are noted to USED_IVS and | |
3416 | USED_INV. */ | |
3417 | ||
3418 | static unsigned | |
3419 | find_best_candidate (struct ivopts_data *data, | |
3420 | struct iv_use *use, bitmap sol, bitmap inv, | |
3421 | bitmap used_ivs, bitmap used_inv, struct iv_cand **cand) | |
3422 | { | |
3423 | unsigned c, d; | |
3424 | unsigned best_cost = INFTY, cost; | |
3425 | struct iv_cand *cnd = NULL, *acnd; | |
3426 | bitmap depends_on = NULL, asol; | |
87c476a2 | 3427 | bitmap_iterator bi, bi1; |
8b11a64c ZD |
3428 | |
3429 | if (data->consider_all_candidates) | |
3430 | asol = sol; | |
3431 | else | |
3432 | { | |
3433 | asol = BITMAP_XMALLOC (); | |
3434 | bitmap_a_and_b (asol, sol, use->related_cands); | |
3435 | } | |
3436 | ||
87c476a2 | 3437 | EXECUTE_IF_SET_IN_BITMAP (asol, 0, c, bi) |
8b11a64c ZD |
3438 | { |
3439 | acnd = iv_cand (data, c); | |
3440 | cost = get_use_iv_cost (data, use, acnd, &depends_on); | |
3441 | ||
3442 | if (cost == INFTY) | |
87c476a2 | 3443 | continue; |
8b11a64c | 3444 | if (cost > best_cost) |
87c476a2 | 3445 | continue; |
8b11a64c ZD |
3446 | if (cost == best_cost) |
3447 | { | |
3448 | /* Prefer the cheaper iv. */ | |
3449 | if (acnd->cost >= cnd->cost) | |
87c476a2 | 3450 | continue; |
8b11a64c ZD |
3451 | } |
3452 | ||
3453 | if (depends_on) | |
3454 | { | |
87c476a2 ZD |
3455 | EXECUTE_IF_AND_COMPL_IN_BITMAP (depends_on, inv, 0, d, bi1) |
3456 | { | |
3457 | goto next_cand; | |
3458 | } | |
8b11a64c ZD |
3459 | if (used_inv) |
3460 | bitmap_a_or_b (used_inv, used_inv, depends_on); | |
3461 | } | |
3462 | ||
3463 | cnd = acnd; | |
3464 | best_cost = cost; | |
87c476a2 | 3465 | |
8b11a64c | 3466 | next_cand: ; |
87c476a2 | 3467 | } |
8b11a64c ZD |
3468 | |
3469 | if (cnd && used_ivs) | |
3470 | bitmap_set_bit (used_ivs, cnd->id); | |
3471 | ||
3472 | if (cand) | |
3473 | *cand = cnd; | |
3474 | ||
3475 | if (!data->consider_all_candidates) | |
3476 | BITMAP_XFREE (asol); | |
3477 | ||
3478 | return best_cost; | |
3479 | } | |
3480 | ||
3481 | /* Returns cost of set of ivs SOL + invariants INV. Removes unnecessary | |
3482 | induction variable candidates and invariants from the sets. Only | |
3483 | uses 0 .. MAX_USE - 1 are taken into account. */ | |
3484 | ||
3485 | static unsigned | |
3486 | set_cost_up_to (struct ivopts_data *data, bitmap sol, bitmap inv, | |
3487 | unsigned max_use) | |
3488 | { | |
3489 | unsigned i; | |
3490 | unsigned cost = 0, size = 0, acost; | |
3491 | struct iv_use *use; | |
3492 | struct iv_cand *cand; | |
3493 | bitmap used_ivs = BITMAP_XMALLOC (), used_inv = BITMAP_XMALLOC (); | |
87c476a2 | 3494 | bitmap_iterator bi; |
8b11a64c ZD |
3495 | |
3496 | for (i = 0; i < max_use; i++) | |
3497 | { | |
3498 | use = iv_use (data, i); | |
3499 | acost = find_best_candidate (data, use, sol, inv, | |
3500 | used_ivs, used_inv, NULL); | |
3501 | if (acost == INFTY) | |
3502 | { | |
3503 | BITMAP_XFREE (used_ivs); | |
3504 | BITMAP_XFREE (used_inv); | |
3505 | return INFTY; | |
3506 | } | |
3507 | cost += acost; | |
3508 | } | |
3509 | ||
87c476a2 | 3510 | EXECUTE_IF_SET_IN_BITMAP (used_ivs, 0, i, bi) |
8b11a64c ZD |
3511 | { |
3512 | cand = iv_cand (data, i); | |
3513 | ||
3514 | /* Do not count the pseudocandidates. */ | |
3515 | if (cand->iv) | |
3516 | size++; | |
3517 | ||
3518 | cost += cand->cost; | |
87c476a2 ZD |
3519 | } |
3520 | EXECUTE_IF_SET_IN_BITMAP (used_inv, 0, i, bi) | |
3521 | { | |
3522 | size++; | |
3523 | } | |
8b11a64c ZD |
3524 | cost += ivopts_global_cost_for_size (data, size); |
3525 | ||
3526 | bitmap_copy (sol, used_ivs); | |
3527 | bitmap_copy (inv, used_inv); | |
3528 | ||
3529 | BITMAP_XFREE (used_ivs); | |
3530 | BITMAP_XFREE (used_inv); | |
3531 | ||
3532 | return cost; | |
3533 | } | |
3534 | ||
3535 | /* Computes cost of set of ivs SOL + invariants INV. Removes unnecessary | |
3536 | induction variable candidates and invariants from the sets. */ | |
3537 | ||
3538 | static unsigned | |
3539 | set_cost (struct ivopts_data *data, bitmap sol, bitmap inv) | |
3540 | { | |
3541 | return set_cost_up_to (data, sol, inv, n_iv_uses (data)); | |
3542 | } | |
3543 | ||
3544 | /* Tries to extend the sets IVS and INV in the best possible way in order | |
3545 | to express the USE. */ | |
3546 | ||
3547 | static bool | |
3548 | try_add_cand_for (struct ivopts_data *data, bitmap ivs, bitmap inv, | |
3549 | struct iv_use *use) | |
3550 | { | |
3551 | unsigned best_cost = set_cost_up_to (data, ivs, inv, use->id + 1), act_cost; | |
3552 | bitmap best_ivs = BITMAP_XMALLOC (); | |
3553 | bitmap best_inv = BITMAP_XMALLOC (); | |
3554 | bitmap act_ivs = BITMAP_XMALLOC (); | |
3555 | bitmap act_inv = BITMAP_XMALLOC (); | |
3556 | unsigned i; | |
3557 | struct cost_pair *cp; | |
3558 | ||
3559 | bitmap_copy (best_ivs, ivs); | |
3560 | bitmap_copy (best_inv, inv); | |
3561 | ||
3562 | for (i = 0; i < use->n_map_members; i++) | |
3563 | { | |
3564 | cp = use->cost_map + i; | |
3565 | if (cp->cost == INFTY) | |
3566 | continue; | |
3567 | ||
3568 | bitmap_copy (act_ivs, ivs); | |
3569 | bitmap_set_bit (act_ivs, cp->cand->id); | |
3570 | if (cp->depends_on) | |
3571 | bitmap_a_or_b (act_inv, inv, cp->depends_on); | |
3572 | else | |
3573 | bitmap_copy (act_inv, inv); | |
3574 | act_cost = set_cost_up_to (data, act_ivs, act_inv, use->id + 1); | |
3575 | ||
3576 | if (act_cost < best_cost) | |
3577 | { | |
3578 | best_cost = act_cost; | |
3579 | bitmap_copy (best_ivs, act_ivs); | |
3580 | bitmap_copy (best_inv, act_inv); | |
3581 | } | |
3582 | } | |
3583 | ||
3584 | bitmap_copy (ivs, best_ivs); | |
3585 | bitmap_copy (inv, best_inv); | |
3586 | ||
3587 | BITMAP_XFREE (best_ivs); | |
3588 | BITMAP_XFREE (best_inv); | |
3589 | BITMAP_XFREE (act_ivs); | |
3590 | BITMAP_XFREE (act_inv); | |
3591 | ||
3592 | return (best_cost != INFTY); | |
3593 | } | |
3594 | ||
3595 | /* Finds an initial set of IVS and invariants INV. We do this by simply | |
3596 | choosing the best candidate for each use. */ | |
3597 | ||
3598 | static unsigned | |
3599 | get_initial_solution (struct ivopts_data *data, bitmap ivs, bitmap inv) | |
3600 | { | |
3601 | unsigned i; | |
3602 | ||
3603 | for (i = 0; i < n_iv_uses (data); i++) | |
3604 | if (!try_add_cand_for (data, ivs, inv, iv_use (data, i))) | |
3605 | return INFTY; | |
3606 | ||
3607 | return set_cost (data, ivs, inv); | |
3608 | } | |
3609 | ||
3610 | /* Tries to improve set of induction variables IVS and invariants INV to get | |
3611 | it better than COST. */ | |
3612 | ||
3613 | static bool | |
3614 | try_improve_iv_set (struct ivopts_data *data, | |
3615 | bitmap ivs, bitmap inv, unsigned *cost) | |
3616 | { | |
3617 | unsigned i, acost; | |
3618 | bitmap new_ivs = BITMAP_XMALLOC (), new_inv = BITMAP_XMALLOC (); | |
3619 | bitmap best_new_ivs = NULL, best_new_inv = NULL; | |
3620 | ||
3621 | /* Try altering the set of induction variables by one. */ | |
3622 | for (i = 0; i < n_iv_cands (data); i++) | |
3623 | { | |
3624 | bitmap_copy (new_ivs, ivs); | |
3625 | bitmap_copy (new_inv, inv); | |
3626 | ||
3627 | if (bitmap_bit_p (ivs, i)) | |
3628 | bitmap_clear_bit (new_ivs, i); | |
3629 | else | |
3630 | bitmap_set_bit (new_ivs, i); | |
3631 | ||
3632 | acost = set_cost (data, new_ivs, new_inv); | |
3633 | if (acost >= *cost) | |
3634 | continue; | |
3635 | ||
3636 | if (!best_new_ivs) | |
3637 | { | |
3638 | best_new_ivs = BITMAP_XMALLOC (); | |
3639 | best_new_inv = BITMAP_XMALLOC (); | |
3640 | } | |
3641 | ||
3642 | *cost = acost; | |
3643 | bitmap_copy (best_new_ivs, new_ivs); | |
3644 | bitmap_copy (best_new_inv, new_inv); | |
3645 | } | |
3646 | ||
3647 | /* Ditto for invariants. */ | |
3648 | for (i = 1; i <= data->max_inv_id; i++) | |
3649 | { | |
3650 | if (ver_info (data, i)->has_nonlin_use) | |
3651 | continue; | |
3652 | ||
3653 | bitmap_copy (new_ivs, ivs); | |
3654 | bitmap_copy (new_inv, inv); | |
3655 | ||
3656 | if (bitmap_bit_p (inv, i)) | |
3657 | bitmap_clear_bit (new_inv, i); | |
3658 | else | |
3659 | bitmap_set_bit (new_inv, i); | |
3660 | ||
3661 | acost = set_cost (data, new_ivs, new_inv); | |
3662 | if (acost >= *cost) | |
3663 | continue; | |
3664 | ||
3665 | if (!best_new_ivs) | |
3666 | { | |
3667 | best_new_ivs = BITMAP_XMALLOC (); | |
3668 | best_new_inv = BITMAP_XMALLOC (); | |
3669 | } | |
3670 | ||
3671 | *cost = acost; | |
3672 | bitmap_copy (best_new_ivs, new_ivs); | |
3673 | bitmap_copy (best_new_inv, new_inv); | |
3674 | } | |
3675 | ||
3676 | BITMAP_XFREE (new_ivs); | |
3677 | BITMAP_XFREE (new_inv); | |
3678 | ||
3679 | if (!best_new_ivs) | |
3680 | return false; | |
3681 | ||
3682 | bitmap_copy (ivs, best_new_ivs); | |
3683 | bitmap_copy (inv, best_new_inv); | |
3684 | BITMAP_XFREE (best_new_ivs); | |
3685 | BITMAP_XFREE (best_new_inv); | |
3686 | return true; | |
3687 | } | |
3688 | ||
3689 | /* Attempts to find the optimal set of induction variables. We do simple | |
3690 | greedy heuristic -- we try to replace at most one candidate in the selected | |
3691 | solution and remove the unused ivs while this improves the cost. */ | |
3692 | ||
3693 | static bitmap | |
3694 | find_optimal_iv_set (struct ivopts_data *data) | |
3695 | { | |
3696 | unsigned cost, i; | |
3697 | bitmap set = BITMAP_XMALLOC (); | |
3698 | bitmap inv = BITMAP_XMALLOC (); | |
3699 | struct iv_use *use; | |
3700 | ||
3701 | /* Set the upper bound. */ | |
3702 | cost = get_initial_solution (data, set, inv); | |
3703 | if (cost == INFTY) | |
3704 | { | |
3705 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3706 | fprintf (dump_file, "Unable to substitute for ivs, failed.\n"); | |
3707 | BITMAP_XFREE (inv); | |
3708 | BITMAP_XFREE (set); | |
3709 | return NULL; | |
3710 | } | |
3711 | ||
3712 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3713 | { | |
3714 | fprintf (dump_file, "Initial set of candidates (cost %d): ", cost); | |
3715 | bitmap_print (dump_file, set, "", ""); | |
3716 | fprintf (dump_file, " invariants "); | |
3717 | bitmap_print (dump_file, inv, "", ""); | |
3718 | fprintf (dump_file, "\n"); | |
3719 | } | |
3720 | ||
3721 | while (try_improve_iv_set (data, set, inv, &cost)) | |
3722 | { | |
3723 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3724 | { | |
3725 | fprintf (dump_file, "Improved to (cost %d): ", cost); | |
3726 | bitmap_print (dump_file, set, "", ""); | |
3727 | fprintf (dump_file, " invariants "); | |
3728 | bitmap_print (dump_file, inv, "", ""); | |
3729 | fprintf (dump_file, "\n"); | |
3730 | } | |
3731 | } | |
3732 | ||
3733 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3734 | fprintf (dump_file, "Final cost %d\n\n", cost); | |
3735 | ||
3736 | for (i = 0; i < n_iv_uses (data); i++) | |
3737 | { | |
3738 | use = iv_use (data, i); | |
3739 | find_best_candidate (data, use, set, inv, NULL, NULL, &use->selected); | |
3740 | } | |
3741 | ||
3742 | BITMAP_XFREE (inv); | |
3743 | ||
3744 | return set; | |
3745 | } | |
3746 | ||
3747 | /* Creates a new induction variable corresponding to CAND. */ | |
3748 | ||
3749 | static void | |
3750 | create_new_iv (struct ivopts_data *data, struct iv_cand *cand) | |
3751 | { | |
3752 | block_stmt_iterator incr_pos; | |
3753 | tree base; | |
3754 | bool after = false; | |
3755 | ||
3756 | if (!cand->iv) | |
3757 | return; | |
3758 | ||
3759 | switch (cand->pos) | |
3760 | { | |
3761 | case IP_NORMAL: | |
3762 | incr_pos = bsi_last (ip_normal_pos (data->current_loop)); | |
3763 | break; | |
3764 | ||
3765 | case IP_END: | |
3766 | incr_pos = bsi_last (ip_end_pos (data->current_loop)); | |
3767 | after = true; | |
3768 | break; | |
3769 | ||
3770 | case IP_ORIGINAL: | |
3771 | /* Mark that the iv is preserved. */ | |
3772 | name_info (data, cand->var_before)->preserve_biv = true; | |
3773 | name_info (data, cand->var_after)->preserve_biv = true; | |
3774 | ||
3775 | /* Rewrite the increment so that it uses var_before directly. */ | |
3776 | find_interesting_uses_op (data, cand->var_after)->selected = cand; | |
3777 | ||
3778 | return; | |
3779 | } | |
3780 | ||
3781 | gimple_add_tmp_var (cand->var_before); | |
3782 | add_referenced_tmp_var (cand->var_before); | |
3783 | ||
3784 | base = unshare_expr (cand->iv->base); | |
3785 | ||
3786 | create_iv (base, cand->iv->step, cand->var_before, data->current_loop, | |
3787 | &incr_pos, after, &cand->var_before, &cand->var_after); | |
3788 | } | |
3789 | ||
3790 | /* Creates new induction variables described in SET. */ | |
3791 | ||
3792 | static void | |
3793 | create_new_ivs (struct ivopts_data *data, bitmap set) | |
3794 | { | |
3795 | unsigned i; | |
3796 | struct iv_cand *cand; | |
87c476a2 | 3797 | bitmap_iterator bi; |
8b11a64c | 3798 | |
87c476a2 | 3799 | EXECUTE_IF_SET_IN_BITMAP (set, 0, i, bi) |
8b11a64c ZD |
3800 | { |
3801 | cand = iv_cand (data, i); | |
3802 | create_new_iv (data, cand); | |
87c476a2 | 3803 | } |
8b11a64c ZD |
3804 | } |
3805 | ||
3806 | /* Removes statement STMT (real or a phi node). If INCLUDING_DEFINED_NAME | |
3807 | is true, remove also the ssa name defined by the statement. */ | |
3808 | ||
3809 | static void | |
3810 | remove_statement (tree stmt, bool including_defined_name) | |
3811 | { | |
3812 | if (TREE_CODE (stmt) == PHI_NODE) | |
3813 | { | |
3814 | if (!including_defined_name) | |
3815 | { | |
3816 | /* Prevent the ssa name defined by the statement from being removed. */ | |
3817 | SET_PHI_RESULT (stmt, NULL); | |
3818 | } | |
3819 | remove_phi_node (stmt, NULL_TREE, bb_for_stmt (stmt)); | |
3820 | } | |
3821 | else | |
3822 | { | |
3823 | block_stmt_iterator bsi = stmt_for_bsi (stmt); | |
3824 | ||
3825 | bsi_remove (&bsi); | |
3826 | } | |
3827 | } | |
3828 | ||
3829 | /* Rewrites USE (definition of iv used in a nonlinear expression) | |
3830 | using candidate CAND. */ | |
3831 | ||
3832 | static void | |
3833 | rewrite_use_nonlinear_expr (struct ivopts_data *data, | |
3834 | struct iv_use *use, struct iv_cand *cand) | |
3835 | { | |
3836 | tree comp = unshare_expr (get_computation (data->current_loop, | |
3837 | use, cand)); | |
3838 | tree op, stmts, tgt, ass; | |
3839 | block_stmt_iterator bsi, pbsi; | |
3840 | ||
1e128c5f | 3841 | switch (TREE_CODE (use->stmt)) |
8b11a64c | 3842 | { |
1e128c5f | 3843 | case PHI_NODE: |
8b11a64c ZD |
3844 | tgt = PHI_RESULT (use->stmt); |
3845 | ||
3846 | /* If we should keep the biv, do not replace it. */ | |
3847 | if (name_info (data, tgt)->preserve_biv) | |
3848 | return; | |
3849 | ||
3850 | pbsi = bsi = bsi_start (bb_for_stmt (use->stmt)); | |
3851 | while (!bsi_end_p (pbsi) | |
3852 | && TREE_CODE (bsi_stmt (pbsi)) == LABEL_EXPR) | |
3853 | { | |
3854 | bsi = pbsi; | |
3855 | bsi_next (&pbsi); | |
3856 | } | |
1e128c5f GB |
3857 | break; |
3858 | ||
3859 | case MODIFY_EXPR: | |
8b11a64c ZD |
3860 | tgt = TREE_OPERAND (use->stmt, 0); |
3861 | bsi = stmt_for_bsi (use->stmt); | |
1e128c5f GB |
3862 | break; |
3863 | ||
3864 | default: | |
3865 | gcc_unreachable (); | |
8b11a64c | 3866 | } |
8b11a64c ZD |
3867 | |
3868 | op = force_gimple_operand (comp, &stmts, false, SSA_NAME_VAR (tgt)); | |
3869 | ||
3870 | if (TREE_CODE (use->stmt) == PHI_NODE) | |
3871 | { | |
3872 | if (stmts) | |
3873 | bsi_insert_after (&bsi, stmts, BSI_CONTINUE_LINKING); | |
3874 | ass = build2 (MODIFY_EXPR, TREE_TYPE (tgt), tgt, op); | |
3875 | bsi_insert_after (&bsi, ass, BSI_NEW_STMT); | |
3876 | remove_statement (use->stmt, false); | |
3877 | SSA_NAME_DEF_STMT (tgt) = ass; | |
3878 | } | |
3879 | else | |
3880 | { | |
3881 | if (stmts) | |
3882 | bsi_insert_before (&bsi, stmts, BSI_SAME_STMT); | |
3883 | TREE_OPERAND (use->stmt, 1) = op; | |
3884 | } | |
3885 | } | |
3886 | ||
3887 | /* Replaces ssa name in index IDX by its basic variable. Callback for | |
3888 | for_each_index. */ | |
3889 | ||
3890 | static bool | |
be35cf60 | 3891 | idx_remove_ssa_names (tree base, tree *idx, |
8b11a64c ZD |
3892 | void *data ATTRIBUTE_UNUSED) |
3893 | { | |
be35cf60 ZD |
3894 | tree *op; |
3895 | ||
8b11a64c ZD |
3896 | if (TREE_CODE (*idx) == SSA_NAME) |
3897 | *idx = SSA_NAME_VAR (*idx); | |
be35cf60 ZD |
3898 | |
3899 | if (TREE_CODE (base) == ARRAY_REF) | |
3900 | { | |
3901 | op = &TREE_OPERAND (base, 2); | |
3902 | if (*op | |
3903 | && TREE_CODE (*op) == SSA_NAME) | |
3904 | *op = SSA_NAME_VAR (*op); | |
3905 | op = &TREE_OPERAND (base, 3); | |
3906 | if (*op | |
3907 | && TREE_CODE (*op) == SSA_NAME) | |
3908 | *op = SSA_NAME_VAR (*op); | |
3909 | } | |
3910 | ||
8b11a64c ZD |
3911 | return true; |
3912 | } | |
3913 | ||
3914 | /* Unshares REF and replaces ssa names inside it by their basic variables. */ | |
3915 | ||
3916 | static tree | |
3917 | unshare_and_remove_ssa_names (tree ref) | |
3918 | { | |
3919 | ref = unshare_expr (ref); | |
3920 | for_each_index (&ref, idx_remove_ssa_names, NULL); | |
3921 | ||
3922 | return ref; | |
3923 | } | |
3924 | ||
3925 | /* Rewrites base of memory access OP with expression WITH in statement | |
3926 | pointed to by BSI. */ | |
3927 | ||
3928 | static void | |
3929 | rewrite_address_base (block_stmt_iterator *bsi, tree *op, tree with) | |
3930 | { | |
7ccf35ed | 3931 | tree bvar, var, new_var, new_name, copy, name; |
8b11a64c ZD |
3932 | tree orig; |
3933 | ||
7ccf35ed DN |
3934 | var = bvar = get_base_address (*op); |
3935 | ||
8b11a64c ZD |
3936 | if (!var || TREE_CODE (with) != SSA_NAME) |
3937 | goto do_rewrite; | |
be35cf60 ZD |
3938 | |
3939 | gcc_assert (TREE_CODE (var) != ALIGN_INDIRECT_REF); | |
3940 | gcc_assert (TREE_CODE (var) != MISALIGNED_INDIRECT_REF); | |
3941 | if (TREE_CODE (var) == INDIRECT_REF) | |
8b11a64c ZD |
3942 | var = TREE_OPERAND (var, 0); |
3943 | if (TREE_CODE (var) == SSA_NAME) | |
3944 | { | |
3945 | name = var; | |
3946 | var = SSA_NAME_VAR (var); | |
3947 | } | |
3948 | else if (DECL_P (var)) | |
3949 | name = NULL_TREE; | |
3950 | else | |
3951 | goto do_rewrite; | |
3952 | ||
3953 | if (var_ann (var)->type_mem_tag) | |
3954 | var = var_ann (var)->type_mem_tag; | |
3955 | ||
3956 | /* We need to add a memory tag for the variable. But we do not want | |
3957 | to add it to the temporary used for the computations, since this leads | |
3958 | to problems in redundancy elimination when there are common parts | |
3959 | in two computations referring to the different arrays. So we copy | |
3960 | the variable to a new temporary. */ | |
3961 | copy = build2 (MODIFY_EXPR, void_type_node, NULL_TREE, with); | |
3962 | if (name) | |
3963 | new_name = duplicate_ssa_name (name, copy); | |
3964 | else | |
3965 | { | |
3966 | new_var = create_tmp_var (TREE_TYPE (with), "ruatmp"); | |
3967 | add_referenced_tmp_var (new_var); | |
3968 | var_ann (new_var)->type_mem_tag = var; | |
3969 | new_name = make_ssa_name (new_var, copy); | |
3970 | } | |
3971 | TREE_OPERAND (copy, 0) = new_name; | |
3972 | bsi_insert_before (bsi, copy, BSI_SAME_STMT); | |
3973 | with = new_name; | |
3974 | ||
3975 | do_rewrite: | |
3976 | ||
3977 | orig = NULL_TREE; | |
be35cf60 ZD |
3978 | gcc_assert (TREE_CODE (*op) != ALIGN_INDIRECT_REF); |
3979 | gcc_assert (TREE_CODE (*op) != MISALIGNED_INDIRECT_REF); | |
3980 | ||
3981 | if (TREE_CODE (*op) == INDIRECT_REF) | |
8b11a64c ZD |
3982 | orig = REF_ORIGINAL (*op); |
3983 | if (!orig) | |
3984 | orig = unshare_and_remove_ssa_names (*op); | |
3985 | ||
be35cf60 | 3986 | *op = build1 (INDIRECT_REF, TREE_TYPE (*op), with); |
7ccf35ed | 3987 | |
8b11a64c ZD |
3988 | /* Record the original reference, for purposes of alias analysis. */ |
3989 | REF_ORIGINAL (*op) = orig; | |
3990 | } | |
3991 | ||
3992 | /* Rewrites USE (address that is an iv) using candidate CAND. */ | |
3993 | ||
3994 | static void | |
3995 | rewrite_use_address (struct ivopts_data *data, | |
3996 | struct iv_use *use, struct iv_cand *cand) | |
3997 | { | |
3998 | tree comp = unshare_expr (get_computation (data->current_loop, | |
3999 | use, cand)); | |
4000 | block_stmt_iterator bsi = stmt_for_bsi (use->stmt); | |
4001 | tree stmts; | |
4002 | tree op = force_gimple_operand (comp, &stmts, true, NULL_TREE); | |
4003 | ||
4004 | if (stmts) | |
4005 | bsi_insert_before (&bsi, stmts, BSI_SAME_STMT); | |
4006 | ||
4007 | rewrite_address_base (&bsi, use->op_p, op); | |
4008 | } | |
4009 | ||
4010 | /* Rewrites USE (the condition such that one of the arguments is an iv) using | |
4011 | candidate CAND. */ | |
4012 | ||
4013 | static void | |
4014 | rewrite_use_compare (struct ivopts_data *data, | |
4015 | struct iv_use *use, struct iv_cand *cand) | |
4016 | { | |
4017 | tree comp; | |
4018 | tree *op_p, cond, op, stmts, bound; | |
4019 | block_stmt_iterator bsi = stmt_for_bsi (use->stmt); | |
4020 | enum tree_code compare; | |
4021 | ||
4022 | if (may_eliminate_iv (data->current_loop, | |
4023 | use, cand, &compare, &bound)) | |
4024 | { | |
4025 | op = force_gimple_operand (unshare_expr (bound), &stmts, | |
4026 | true, NULL_TREE); | |
4027 | ||
4028 | if (stmts) | |
4029 | bsi_insert_before (&bsi, stmts, BSI_SAME_STMT); | |
4030 | ||
4031 | *use->op_p = build2 (compare, boolean_type_node, | |
4032 | var_at_stmt (data->current_loop, | |
4033 | cand, use->stmt), op); | |
4034 | modify_stmt (use->stmt); | |
4035 | return; | |
4036 | } | |
4037 | ||
4038 | /* The induction variable elimination failed; just express the original | |
4039 | giv. */ | |
4040 | comp = unshare_expr (get_computation (data->current_loop, use, cand)); | |
4041 | ||
4042 | cond = *use->op_p; | |
4043 | op_p = &TREE_OPERAND (cond, 0); | |
4044 | if (TREE_CODE (*op_p) != SSA_NAME | |
4045 | || zero_p (get_iv (data, *op_p)->step)) | |
4046 | op_p = &TREE_OPERAND (cond, 1); | |
4047 | ||
4048 | op = force_gimple_operand (comp, &stmts, true, SSA_NAME_VAR (*op_p)); | |
4049 | if (stmts) | |
4050 | bsi_insert_before (&bsi, stmts, BSI_SAME_STMT); | |
4051 | ||
4052 | *op_p = op; | |
4053 | } | |
4054 | ||
4055 | /* Ensure that operand *OP_P may be used at the end of EXIT without | |
4056 | violating loop closed ssa form. */ | |
4057 | ||
4058 | static void | |
4059 | protect_loop_closed_ssa_form_use (edge exit, use_operand_p op_p) | |
4060 | { | |
4061 | basic_block def_bb; | |
4062 | struct loop *def_loop; | |
4063 | tree phi, use; | |
4064 | ||
4065 | use = USE_FROM_PTR (op_p); | |
4066 | if (TREE_CODE (use) != SSA_NAME) | |
4067 | return; | |
4068 | ||
4069 | def_bb = bb_for_stmt (SSA_NAME_DEF_STMT (use)); | |
4070 | if (!def_bb) | |
4071 | return; | |
4072 | ||
4073 | def_loop = def_bb->loop_father; | |
4074 | if (flow_bb_inside_loop_p (def_loop, exit->dest)) | |
4075 | return; | |
4076 | ||
4077 | /* Try finding a phi node that copies the value out of the loop. */ | |
4078 | for (phi = phi_nodes (exit->dest); phi; phi = TREE_CHAIN (phi)) | |
4079 | if (PHI_ARG_DEF_FROM_EDGE (phi, exit) == use) | |
4080 | break; | |
4081 | ||
4082 | if (!phi) | |
4083 | { | |
4084 | /* Create such a phi node. */ | |
4085 | tree new_name = duplicate_ssa_name (use, NULL); | |
4086 | ||
4087 | phi = create_phi_node (new_name, exit->dest); | |
4088 | SSA_NAME_DEF_STMT (new_name) = phi; | |
4089 | add_phi_arg (&phi, use, exit); | |
4090 | } | |
4091 | ||
4092 | SET_USE (op_p, PHI_RESULT (phi)); | |
4093 | } | |
4094 | ||
4095 | /* Ensure that operands of STMT may be used at the end of EXIT without | |
4096 | violating loop closed ssa form. */ | |
4097 | ||
4098 | static void | |
4099 | protect_loop_closed_ssa_form (edge exit, tree stmt) | |
4100 | { | |
4101 | use_optype uses; | |
4102 | vuse_optype vuses; | |
4103 | v_may_def_optype v_may_defs; | |
4104 | unsigned i; | |
4105 | ||
4106 | get_stmt_operands (stmt); | |
4107 | ||
4108 | uses = STMT_USE_OPS (stmt); | |
4109 | for (i = 0; i < NUM_USES (uses); i++) | |
4110 | protect_loop_closed_ssa_form_use (exit, USE_OP_PTR (uses, i)); | |
4111 | ||
4112 | vuses = STMT_VUSE_OPS (stmt); | |
4113 | for (i = 0; i < NUM_VUSES (vuses); i++) | |
4114 | protect_loop_closed_ssa_form_use (exit, VUSE_OP_PTR (vuses, i)); | |
4115 | ||
4116 | v_may_defs = STMT_V_MAY_DEF_OPS (stmt); | |
4117 | for (i = 0; i < NUM_V_MAY_DEFS (v_may_defs); i++) | |
4118 | protect_loop_closed_ssa_form_use (exit, V_MAY_DEF_OP_PTR (v_may_defs, i)); | |
4119 | } | |
4120 | ||
4121 | /* STMTS compute a value of a phi argument OP on EXIT of a loop. Arrange things | |
4122 | so that they are emitted on the correct place, and so that the loop closed | |
4123 | ssa form is preserved. */ | |
4124 | ||
4125 | static void | |
4126 | compute_phi_arg_on_exit (edge exit, tree stmts, tree op) | |
4127 | { | |
4128 | tree_stmt_iterator tsi; | |
4129 | block_stmt_iterator bsi; | |
4130 | tree phi, stmt, def, next; | |
4131 | ||
628f6a4e | 4132 | if (EDGE_COUNT (exit->dest->preds) > 1) |
8b11a64c ZD |
4133 | split_loop_exit_edge (exit); |
4134 | ||
4135 | if (TREE_CODE (stmts) == STATEMENT_LIST) | |
4136 | { | |
4137 | for (tsi = tsi_start (stmts); !tsi_end_p (tsi); tsi_next (&tsi)) | |
4138 | protect_loop_closed_ssa_form (exit, tsi_stmt (tsi)); | |
4139 | } | |
4140 | else | |
4141 | protect_loop_closed_ssa_form (exit, stmts); | |
4142 | ||
4143 | /* Ensure there is label in exit->dest, so that we can | |
4144 | insert after it. */ | |
4145 | tree_block_label (exit->dest); | |
4146 | bsi = bsi_after_labels (exit->dest); | |
4147 | bsi_insert_after (&bsi, stmts, BSI_CONTINUE_LINKING); | |
4148 | ||
4149 | if (!op) | |
4150 | return; | |
4151 | ||
4152 | for (phi = phi_nodes (exit->dest); phi; phi = next) | |
4153 | { | |
4154 | next = TREE_CHAIN (phi); | |
4155 | ||
4156 | if (PHI_ARG_DEF_FROM_EDGE (phi, exit) == op) | |
4157 | { | |
4158 | def = PHI_RESULT (phi); | |
4159 | remove_statement (phi, false); | |
4160 | stmt = build2 (MODIFY_EXPR, TREE_TYPE (op), | |
4161 | def, op); | |
4162 | SSA_NAME_DEF_STMT (def) = stmt; | |
4163 | bsi_insert_after (&bsi, stmt, BSI_CONTINUE_LINKING); | |
4164 | } | |
4165 | } | |
4166 | } | |
4167 | ||
4168 | /* Rewrites the final value of USE (that is only needed outside of the loop) | |
4169 | using candidate CAND. */ | |
4170 | ||
4171 | static void | |
4172 | rewrite_use_outer (struct ivopts_data *data, | |
4173 | struct iv_use *use, struct iv_cand *cand) | |
4174 | { | |
4175 | edge exit; | |
4176 | tree value, op, stmts, tgt; | |
4177 | tree phi; | |
4178 | ||
1e128c5f GB |
4179 | switch (TREE_CODE (use->stmt)) |
4180 | { | |
4181 | case PHI_NODE: | |
4182 | tgt = PHI_RESULT (use->stmt); | |
4183 | break; | |
4184 | case MODIFY_EXPR: | |
4185 | tgt = TREE_OPERAND (use->stmt, 0); | |
4186 | break; | |
4187 | default: | |
4188 | gcc_unreachable (); | |
4189 | } | |
4190 | ||
8b11a64c ZD |
4191 | exit = single_dom_exit (data->current_loop); |
4192 | ||
4193 | if (exit) | |
4194 | { | |
4195 | if (!cand->iv) | |
4196 | { | |
1e128c5f GB |
4197 | bool ok = may_replace_final_value (data->current_loop, use, &value); |
4198 | gcc_assert (ok); | |
8b11a64c ZD |
4199 | } |
4200 | else | |
4201 | value = get_computation_at (data->current_loop, | |
4202 | use, cand, last_stmt (exit->src)); | |
4203 | ||
2f4675b4 | 4204 | value = unshare_expr (value); |
8b11a64c ZD |
4205 | op = force_gimple_operand (value, &stmts, true, SSA_NAME_VAR (tgt)); |
4206 | ||
4207 | /* If we will preserve the iv anyway and we would need to perform | |
4208 | some computation to replace the final value, do nothing. */ | |
4209 | if (stmts && name_info (data, tgt)->preserve_biv) | |
4210 | return; | |
4211 | ||
4212 | for (phi = phi_nodes (exit->dest); phi; phi = TREE_CHAIN (phi)) | |
4213 | { | |
4214 | use_operand_p use_p = PHI_ARG_DEF_PTR_FROM_EDGE (phi, exit); | |
4215 | ||
4216 | if (USE_FROM_PTR (use_p) == tgt) | |
4217 | SET_USE (use_p, op); | |
4218 | } | |
4219 | ||
4220 | if (stmts) | |
4221 | compute_phi_arg_on_exit (exit, stmts, op); | |
4222 | ||
4223 | /* Enable removal of the statement. We cannot remove it directly, | |
4224 | since we may still need the aliasing information attached to the | |
4225 | ssa name defined by it. */ | |
4226 | name_info (data, tgt)->iv->have_use_for = false; | |
4227 | return; | |
4228 | } | |
4229 | ||
4230 | /* If the variable is going to be preserved anyway, there is nothing to | |
4231 | do. */ | |
4232 | if (name_info (data, tgt)->preserve_biv) | |
4233 | return; | |
4234 | ||
4235 | /* Otherwise we just need to compute the iv. */ | |
4236 | rewrite_use_nonlinear_expr (data, use, cand); | |
4237 | } | |
4238 | ||
4239 | /* Rewrites USE using candidate CAND. */ | |
4240 | ||
4241 | static void | |
4242 | rewrite_use (struct ivopts_data *data, | |
4243 | struct iv_use *use, struct iv_cand *cand) | |
4244 | { | |
4245 | switch (use->type) | |
4246 | { | |
4247 | case USE_NONLINEAR_EXPR: | |
4248 | rewrite_use_nonlinear_expr (data, use, cand); | |
4249 | break; | |
4250 | ||
4251 | case USE_OUTER: | |
4252 | rewrite_use_outer (data, use, cand); | |
4253 | break; | |
4254 | ||
4255 | case USE_ADDRESS: | |
4256 | rewrite_use_address (data, use, cand); | |
4257 | break; | |
4258 | ||
4259 | case USE_COMPARE: | |
4260 | rewrite_use_compare (data, use, cand); | |
4261 | break; | |
4262 | ||
4263 | default: | |
1e128c5f | 4264 | gcc_unreachable (); |
8b11a64c ZD |
4265 | } |
4266 | modify_stmt (use->stmt); | |
4267 | } | |
4268 | ||
4269 | /* Rewrite the uses using the selected induction variables. */ | |
4270 | ||
4271 | static void | |
4272 | rewrite_uses (struct ivopts_data *data) | |
4273 | { | |
4274 | unsigned i; | |
4275 | struct iv_cand *cand; | |
4276 | struct iv_use *use; | |
4277 | ||
4278 | for (i = 0; i < n_iv_uses (data); i++) | |
4279 | { | |
4280 | use = iv_use (data, i); | |
4281 | cand = use->selected; | |
1e128c5f | 4282 | gcc_assert (cand); |
8b11a64c ZD |
4283 | |
4284 | rewrite_use (data, use, cand); | |
4285 | } | |
4286 | } | |
4287 | ||
4288 | /* Removes the ivs that are not used after rewriting. */ | |
4289 | ||
4290 | static void | |
4291 | remove_unused_ivs (struct ivopts_data *data) | |
4292 | { | |
4293 | unsigned j; | |
87c476a2 | 4294 | bitmap_iterator bi; |
8b11a64c | 4295 | |
87c476a2 | 4296 | EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, j, bi) |
8b11a64c ZD |
4297 | { |
4298 | struct version_info *info; | |
4299 | ||
4300 | info = ver_info (data, j); | |
4301 | if (info->iv | |
4302 | && !zero_p (info->iv->step) | |
4303 | && !info->inv_id | |
4304 | && !info->iv->have_use_for | |
4305 | && !info->preserve_biv) | |
4306 | remove_statement (SSA_NAME_DEF_STMT (info->iv->ssa_name), true); | |
87c476a2 | 4307 | } |
8b11a64c ZD |
4308 | } |
4309 | ||
4310 | /* Frees data allocated by the optimization of a single loop. */ | |
4311 | ||
4312 | static void | |
4313 | free_loop_data (struct ivopts_data *data) | |
4314 | { | |
4315 | unsigned i, j; | |
87c476a2 | 4316 | bitmap_iterator bi; |
8b11a64c | 4317 | |
87c476a2 | 4318 | EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi) |
8b11a64c ZD |
4319 | { |
4320 | struct version_info *info; | |
4321 | ||
4322 | info = ver_info (data, i); | |
4323 | if (info->iv) | |
4324 | free (info->iv); | |
4325 | info->iv = NULL; | |
4326 | info->has_nonlin_use = false; | |
4327 | info->preserve_biv = false; | |
4328 | info->inv_id = 0; | |
87c476a2 | 4329 | } |
8b11a64c ZD |
4330 | bitmap_clear (data->relevant); |
4331 | ||
4332 | for (i = 0; i < n_iv_uses (data); i++) | |
4333 | { | |
4334 | struct iv_use *use = iv_use (data, i); | |
4335 | ||
4336 | free (use->iv); | |
4337 | BITMAP_XFREE (use->related_cands); | |
4338 | for (j = 0; j < use->n_map_members; j++) | |
4339 | if (use->cost_map[j].depends_on) | |
4340 | BITMAP_XFREE (use->cost_map[j].depends_on); | |
4341 | free (use->cost_map); | |
4342 | free (use); | |
4343 | } | |
4344 | VARRAY_POP_ALL (data->iv_uses); | |
4345 | ||
4346 | for (i = 0; i < n_iv_cands (data); i++) | |
4347 | { | |
4348 | struct iv_cand *cand = iv_cand (data, i); | |
4349 | ||
4350 | if (cand->iv) | |
4351 | free (cand->iv); | |
4352 | free (cand); | |
4353 | } | |
4354 | VARRAY_POP_ALL (data->iv_candidates); | |
4355 | ||
4356 | if (data->version_info_size < num_ssa_names) | |
4357 | { | |
4358 | data->version_info_size = 2 * num_ssa_names; | |
4359 | free (data->version_info); | |
4360 | data->version_info = xcalloc (data->version_info_size, | |
4361 | sizeof (struct version_info)); | |
4362 | } | |
4363 | ||
4364 | data->max_inv_id = 0; | |
4365 | ||
4366 | for (i = 0; i < VARRAY_ACTIVE_SIZE (decl_rtl_to_reset); i++) | |
4367 | { | |
4368 | tree obj = VARRAY_GENERIC_PTR_NOGC (decl_rtl_to_reset, i); | |
4369 | ||
4370 | SET_DECL_RTL (obj, NULL_RTX); | |
4371 | } | |
4372 | VARRAY_POP_ALL (decl_rtl_to_reset); | |
4373 | } | |
4374 | ||
4375 | /* Finalizes data structures used by the iv optimization pass. LOOPS is the | |
4376 | loop tree. */ | |
4377 | ||
4378 | static void | |
4379 | tree_ssa_iv_optimize_finalize (struct loops *loops, struct ivopts_data *data) | |
4380 | { | |
4381 | unsigned i; | |
4382 | ||
4383 | for (i = 1; i < loops->num; i++) | |
4384 | if (loops->parray[i]) | |
4385 | { | |
4386 | free (loops->parray[i]->aux); | |
4387 | loops->parray[i]->aux = NULL; | |
4388 | } | |
4389 | ||
4390 | free_loop_data (data); | |
4391 | free (data->version_info); | |
4392 | BITMAP_XFREE (data->relevant); | |
4393 | ||
4394 | VARRAY_FREE (decl_rtl_to_reset); | |
4395 | VARRAY_FREE (data->iv_uses); | |
4396 | VARRAY_FREE (data->iv_candidates); | |
4397 | } | |
4398 | ||
4399 | /* Optimizes the LOOP. Returns true if anything changed. */ | |
4400 | ||
4401 | static bool | |
4402 | tree_ssa_iv_optimize_loop (struct ivopts_data *data, struct loop *loop) | |
4403 | { | |
4404 | bool changed = false; | |
4405 | bitmap iv_set; | |
4406 | edge exit; | |
4407 | ||
4408 | data->current_loop = loop; | |
4409 | ||
4410 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4411 | { | |
4412 | fprintf (dump_file, "Processing loop %d\n", loop->num); | |
4413 | ||
4414 | exit = single_dom_exit (loop); | |
4415 | if (exit) | |
4416 | { | |
4417 | fprintf (dump_file, " single exit %d -> %d, exit condition ", | |
4418 | exit->src->index, exit->dest->index); | |
4419 | print_generic_expr (dump_file, last_stmt (exit->src), TDF_SLIM); | |
4420 | fprintf (dump_file, "\n"); | |
4421 | } | |
4422 | ||
4423 | fprintf (dump_file, "\n"); | |
4424 | } | |
4425 | ||
4426 | /* For each ssa name determines whether it behaves as an induction variable | |
4427 | in some loop. */ | |
4428 | if (!find_induction_variables (data)) | |
4429 | goto finish; | |
4430 | ||
4431 | /* Finds interesting uses (item 1). */ | |
4432 | find_interesting_uses (data); | |
4433 | if (n_iv_uses (data) > MAX_CONSIDERED_USES) | |
4434 | goto finish; | |
4435 | ||
4436 | /* Finds candidates for the induction variables (item 2). */ | |
4437 | find_iv_candidates (data); | |
4438 | ||
4439 | /* Calculates the costs (item 3, part 1). */ | |
4440 | determine_use_iv_costs (data); | |
4441 | determine_iv_costs (data); | |
4442 | determine_set_costs (data); | |
4443 | ||
4444 | /* Find the optimal set of induction variables (item 3, part 2). */ | |
4445 | iv_set = find_optimal_iv_set (data); | |
4446 | if (!iv_set) | |
4447 | goto finish; | |
4448 | changed = true; | |
4449 | ||
4450 | /* Create the new induction variables (item 4, part 1). */ | |
4451 | create_new_ivs (data, iv_set); | |
4452 | ||
4453 | /* Rewrite the uses (item 4, part 2). */ | |
4454 | rewrite_uses (data); | |
4455 | ||
4456 | /* Remove the ivs that are unused after rewriting. */ | |
4457 | remove_unused_ivs (data); | |
4458 | ||
4459 | loop_commit_inserts (); | |
4460 | ||
4461 | BITMAP_XFREE (iv_set); | |
4462 | ||
4463 | /* We have changed the structure of induction variables; it might happen | |
4464 | that definitions in the scev database refer to some of them that were | |
4465 | eliminated. */ | |
4466 | scev_reset (); | |
4467 | ||
4468 | finish: | |
4469 | free_loop_data (data); | |
4470 | ||
4471 | return changed; | |
4472 | } | |
4473 | ||
4474 | /* Main entry point. Optimizes induction variables in LOOPS. */ | |
4475 | ||
4476 | void | |
4477 | tree_ssa_iv_optimize (struct loops *loops) | |
4478 | { | |
4479 | struct loop *loop; | |
4480 | struct ivopts_data data; | |
4481 | ||
4482 | tree_ssa_iv_optimize_init (loops, &data); | |
4483 | ||
4484 | /* Optimize the loops starting with the innermost ones. */ | |
4485 | loop = loops->tree_root; | |
4486 | while (loop->inner) | |
4487 | loop = loop->inner; | |
4488 | ||
4489 | #ifdef ENABLE_CHECKING | |
4490 | verify_loop_closed_ssa (); | |
8679c649 | 4491 | verify_stmts (); |
8b11a64c ZD |
4492 | #endif |
4493 | ||
4494 | /* Scan the loops, inner ones first. */ | |
4495 | while (loop != loops->tree_root) | |
4496 | { | |
8679c649 JH |
4497 | if (dump_file && (dump_flags & TDF_DETAILS)) |
4498 | flow_loop_dump (loop, dump_file, NULL, 1); | |
8b11a64c ZD |
4499 | if (tree_ssa_iv_optimize_loop (&data, loop)) |
4500 | { | |
4501 | #ifdef ENABLE_CHECKING | |
4502 | verify_loop_closed_ssa (); | |
8679c649 | 4503 | verify_stmts (); |
8b11a64c ZD |
4504 | #endif |
4505 | } | |
4506 | ||
4507 | if (loop->next) | |
4508 | { | |
4509 | loop = loop->next; | |
4510 | while (loop->inner) | |
4511 | loop = loop->inner; | |
4512 | } | |
4513 | else | |
4514 | loop = loop->outer; | |
4515 | } | |
4516 | ||
4517 | tree_ssa_iv_optimize_finalize (loops, &data); | |
4518 | } |