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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. */ | |
e6845c23 | 107 | tree base_object; /* A memory object to that the induction variable points. */ |
8b11a64c ZD |
108 | tree step; /* Step of the iv (constant only). */ |
109 | tree ssa_name; /* The ssa name with the value. */ | |
110 | bool biv_p; /* Is it a biv? */ | |
111 | bool have_use_for; /* Do we already have a use for it? */ | |
112 | unsigned use_id; /* The identifier in the use if it is the case. */ | |
113 | }; | |
114 | ||
115 | /* Per-ssa version information (induction variable descriptions, etc.). */ | |
116 | struct version_info | |
117 | { | |
118 | tree name; /* The ssa name. */ | |
119 | struct iv *iv; /* Induction variable description. */ | |
120 | bool has_nonlin_use; /* For a loop-level invariant, whether it is used in | |
121 | an expression that is not an induction variable. */ | |
122 | unsigned inv_id; /* Id of an invariant. */ | |
123 | bool preserve_biv; /* For the original biv, whether to preserve it. */ | |
124 | }; | |
125 | ||
126 | /* Information attached to loop. */ | |
127 | struct loop_data | |
128 | { | |
129 | struct tree_niter_desc niter; | |
130 | /* Number of iterations. */ | |
131 | ||
132 | unsigned regs_used; /* Number of registers used. */ | |
133 | }; | |
134 | ||
135 | /* Types of uses. */ | |
136 | enum use_type | |
137 | { | |
138 | USE_NONLINEAR_EXPR, /* Use in a nonlinear expression. */ | |
139 | USE_OUTER, /* The induction variable is used outside the loop. */ | |
140 | USE_ADDRESS, /* Use in an address. */ | |
141 | USE_COMPARE /* Use is a compare. */ | |
142 | }; | |
143 | ||
144 | /* The candidate - cost pair. */ | |
145 | struct cost_pair | |
146 | { | |
147 | struct iv_cand *cand; /* The candidate. */ | |
148 | unsigned cost; /* The cost. */ | |
149 | bitmap depends_on; /* The list of invariants that have to be | |
150 | preserved. */ | |
151 | }; | |
152 | ||
153 | /* Use. */ | |
154 | struct iv_use | |
155 | { | |
156 | unsigned id; /* The id of the use. */ | |
157 | enum use_type type; /* Type of the use. */ | |
158 | struct iv *iv; /* The induction variable it is based on. */ | |
159 | tree stmt; /* Statement in that it occurs. */ | |
160 | tree *op_p; /* The place where it occurs. */ | |
b1b02be2 ZD |
161 | bitmap related_cands; /* The set of "related" iv candidates, plus the common |
162 | important ones. */ | |
8b11a64c ZD |
163 | |
164 | unsigned n_map_members; /* Number of candidates in the cost_map list. */ | |
165 | struct cost_pair *cost_map; | |
166 | /* The costs wrto the iv candidates. */ | |
167 | ||
168 | struct iv_cand *selected; | |
169 | /* The selected candidate. */ | |
170 | }; | |
171 | ||
172 | /* The position where the iv is computed. */ | |
173 | enum iv_position | |
174 | { | |
175 | IP_NORMAL, /* At the end, just before the exit condition. */ | |
176 | IP_END, /* At the end of the latch block. */ | |
177 | IP_ORIGINAL /* The original biv. */ | |
178 | }; | |
179 | ||
180 | /* The induction variable candidate. */ | |
181 | struct iv_cand | |
182 | { | |
183 | unsigned id; /* The number of the candidate. */ | |
184 | bool important; /* Whether this is an "important" candidate, i.e. such | |
185 | that it should be considered by all uses. */ | |
186 | enum iv_position pos; /* Where it is computed. */ | |
187 | tree incremented_at; /* For original biv, the statement where it is | |
188 | incremented. */ | |
189 | tree var_before; /* The variable used for it before increment. */ | |
190 | tree var_after; /* The variable used for it after increment. */ | |
191 | struct iv *iv; /* The value of the candidate. NULL for | |
192 | "pseudocandidate" used to indicate the possibility | |
193 | to replace the final value of an iv by direct | |
194 | computation of the value. */ | |
195 | unsigned cost; /* Cost of the candidate. */ | |
196 | }; | |
197 | ||
198 | /* The data used by the induction variable optimizations. */ | |
199 | ||
200 | struct ivopts_data | |
201 | { | |
202 | /* The currently optimized loop. */ | |
203 | struct loop *current_loop; | |
204 | ||
205 | /* The size of version_info array allocated. */ | |
206 | unsigned version_info_size; | |
207 | ||
208 | /* The array of information for the ssa names. */ | |
209 | struct version_info *version_info; | |
210 | ||
211 | /* The bitmap of indices in version_info whose value was changed. */ | |
212 | bitmap relevant; | |
213 | ||
214 | /* The maximum invariant id. */ | |
215 | unsigned max_inv_id; | |
216 | ||
217 | /* The uses of induction variables. */ | |
218 | varray_type iv_uses; | |
219 | ||
220 | /* The candidates. */ | |
221 | varray_type iv_candidates; | |
222 | ||
80cad5fa ZD |
223 | /* A bitmap of important candidates. */ |
224 | bitmap important_candidates; | |
225 | ||
8b11a64c ZD |
226 | /* Whether to consider just related and important candidates when replacing a |
227 | use. */ | |
228 | bool consider_all_candidates; | |
229 | }; | |
230 | ||
b1b02be2 ZD |
231 | /* An assignment of iv candidates to uses. */ |
232 | ||
233 | struct iv_ca | |
234 | { | |
235 | /* The number of uses covered by the assignment. */ | |
236 | unsigned upto; | |
237 | ||
238 | /* Number of uses that cannot be expressed by the candidates in the set. */ | |
239 | unsigned bad_uses; | |
240 | ||
241 | /* Candidate assigned to a use, together with the related costs. */ | |
242 | struct cost_pair **cand_for_use; | |
243 | ||
244 | /* Number of times each candidate is used. */ | |
245 | unsigned *n_cand_uses; | |
246 | ||
247 | /* The candidates used. */ | |
248 | bitmap cands; | |
249 | ||
250 | /* Total number of registers needed. */ | |
251 | unsigned n_regs; | |
252 | ||
253 | /* Total cost of expressing uses. */ | |
254 | unsigned cand_use_cost; | |
255 | ||
256 | /* Total cost of candidates. */ | |
257 | unsigned cand_cost; | |
258 | ||
259 | /* Number of times each invariant is used. */ | |
260 | unsigned *n_invariant_uses; | |
261 | ||
262 | /* Total cost of the assignment. */ | |
263 | unsigned cost; | |
264 | }; | |
265 | ||
266 | /* Difference of two iv candidate assignments. */ | |
267 | ||
268 | struct iv_ca_delta | |
269 | { | |
270 | /* Changed use. */ | |
271 | struct iv_use *use; | |
272 | ||
273 | /* An old assignment (for rollback purposes). */ | |
274 | struct cost_pair *old_cp; | |
275 | ||
276 | /* A new assignment. */ | |
277 | struct cost_pair *new_cp; | |
278 | ||
279 | /* Next change in the list. */ | |
280 | struct iv_ca_delta *next_change; | |
281 | }; | |
282 | ||
8b11a64c ZD |
283 | /* Bound on number of candidates below that all candidates are considered. */ |
284 | ||
285 | #define CONSIDER_ALL_CANDIDATES_BOUND \ | |
286 | ((unsigned) PARAM_VALUE (PARAM_IV_CONSIDER_ALL_CANDIDATES_BOUND)) | |
287 | ||
2a7e31df | 288 | /* If there are more iv occurrences, we just give up (it is quite unlikely that |
8b11a64c ZD |
289 | optimizing such a loop would help, and it would take ages). */ |
290 | ||
291 | #define MAX_CONSIDERED_USES \ | |
292 | ((unsigned) PARAM_VALUE (PARAM_IV_MAX_CONSIDERED_USES)) | |
293 | ||
294 | /* The list of trees for that the decl_rtl field must be reset is stored | |
295 | here. */ | |
296 | ||
297 | static varray_type decl_rtl_to_reset; | |
298 | ||
299 | /* Number of uses recorded in DATA. */ | |
300 | ||
301 | static inline unsigned | |
302 | n_iv_uses (struct ivopts_data *data) | |
303 | { | |
304 | return VARRAY_ACTIVE_SIZE (data->iv_uses); | |
305 | } | |
306 | ||
307 | /* Ith use recorded in DATA. */ | |
308 | ||
309 | static inline struct iv_use * | |
310 | iv_use (struct ivopts_data *data, unsigned i) | |
311 | { | |
312 | return VARRAY_GENERIC_PTR_NOGC (data->iv_uses, i); | |
313 | } | |
314 | ||
315 | /* Number of candidates recorded in DATA. */ | |
316 | ||
317 | static inline unsigned | |
318 | n_iv_cands (struct ivopts_data *data) | |
319 | { | |
320 | return VARRAY_ACTIVE_SIZE (data->iv_candidates); | |
321 | } | |
322 | ||
323 | /* Ith candidate recorded in DATA. */ | |
324 | ||
325 | static inline struct iv_cand * | |
326 | iv_cand (struct ivopts_data *data, unsigned i) | |
327 | { | |
328 | return VARRAY_GENERIC_PTR_NOGC (data->iv_candidates, i); | |
329 | } | |
330 | ||
331 | /* The data for LOOP. */ | |
332 | ||
333 | static inline struct loop_data * | |
334 | loop_data (struct loop *loop) | |
335 | { | |
336 | return loop->aux; | |
337 | } | |
338 | ||
339 | /* The single loop exit if it dominates the latch, NULL otherwise. */ | |
340 | ||
341 | static edge | |
342 | single_dom_exit (struct loop *loop) | |
343 | { | |
344 | edge exit = loop->single_exit; | |
345 | ||
346 | if (!exit) | |
347 | return NULL; | |
348 | ||
349 | if (!just_once_each_iteration_p (loop, exit->src)) | |
350 | return NULL; | |
351 | ||
352 | return exit; | |
353 | } | |
354 | ||
355 | /* Dumps information about the induction variable IV to FILE. */ | |
356 | ||
357 | extern void dump_iv (FILE *, struct iv *); | |
358 | void | |
359 | dump_iv (FILE *file, struct iv *iv) | |
360 | { | |
e6845c23 ZD |
361 | if (iv->ssa_name) |
362 | { | |
363 | fprintf (file, "ssa name "); | |
364 | print_generic_expr (file, iv->ssa_name, TDF_SLIM); | |
365 | fprintf (file, "\n"); | |
366 | } | |
8b11a64c | 367 | |
2f4675b4 ZD |
368 | fprintf (file, " type "); |
369 | print_generic_expr (file, TREE_TYPE (iv->base), TDF_SLIM); | |
370 | fprintf (file, "\n"); | |
371 | ||
8b11a64c ZD |
372 | if (iv->step) |
373 | { | |
374 | fprintf (file, " base "); | |
375 | print_generic_expr (file, iv->base, TDF_SLIM); | |
376 | fprintf (file, "\n"); | |
377 | ||
378 | fprintf (file, " step "); | |
379 | print_generic_expr (file, iv->step, TDF_SLIM); | |
380 | fprintf (file, "\n"); | |
381 | } | |
382 | else | |
383 | { | |
384 | fprintf (file, " invariant "); | |
385 | print_generic_expr (file, iv->base, TDF_SLIM); | |
386 | fprintf (file, "\n"); | |
387 | } | |
388 | ||
e6845c23 ZD |
389 | if (iv->base_object) |
390 | { | |
391 | fprintf (file, " base object "); | |
392 | print_generic_expr (file, iv->base_object, TDF_SLIM); | |
393 | fprintf (file, "\n"); | |
394 | } | |
395 | ||
8b11a64c ZD |
396 | if (iv->biv_p) |
397 | fprintf (file, " is a biv\n"); | |
398 | } | |
399 | ||
400 | /* Dumps information about the USE to FILE. */ | |
401 | ||
402 | extern void dump_use (FILE *, struct iv_use *); | |
403 | void | |
404 | dump_use (FILE *file, struct iv_use *use) | |
405 | { | |
8b11a64c ZD |
406 | fprintf (file, "use %d\n", use->id); |
407 | ||
408 | switch (use->type) | |
409 | { | |
410 | case USE_NONLINEAR_EXPR: | |
411 | fprintf (file, " generic\n"); | |
412 | break; | |
413 | ||
414 | case USE_OUTER: | |
415 | fprintf (file, " outside\n"); | |
416 | break; | |
417 | ||
418 | case USE_ADDRESS: | |
419 | fprintf (file, " address\n"); | |
420 | break; | |
421 | ||
422 | case USE_COMPARE: | |
423 | fprintf (file, " compare\n"); | |
424 | break; | |
425 | ||
426 | default: | |
1e128c5f | 427 | gcc_unreachable (); |
8b11a64c ZD |
428 | } |
429 | ||
2f4675b4 ZD |
430 | fprintf (file, " in statement "); |
431 | print_generic_expr (file, use->stmt, TDF_SLIM); | |
432 | fprintf (file, "\n"); | |
433 | ||
434 | fprintf (file, " at position "); | |
435 | if (use->op_p) | |
436 | print_generic_expr (file, *use->op_p, TDF_SLIM); | |
437 | fprintf (file, "\n"); | |
438 | ||
e6845c23 | 439 | dump_iv (file, use->iv); |
2f4675b4 ZD |
440 | |
441 | fprintf (file, " related candidates "); | |
442 | dump_bitmap (file, use->related_cands); | |
8b11a64c ZD |
443 | } |
444 | ||
445 | /* Dumps information about the uses to FILE. */ | |
446 | ||
447 | extern void dump_uses (FILE *, struct ivopts_data *); | |
448 | void | |
449 | dump_uses (FILE *file, struct ivopts_data *data) | |
450 | { | |
451 | unsigned i; | |
452 | struct iv_use *use; | |
453 | ||
454 | for (i = 0; i < n_iv_uses (data); i++) | |
455 | { | |
456 | use = iv_use (data, i); | |
457 | ||
458 | dump_use (file, use); | |
459 | fprintf (file, "\n"); | |
460 | } | |
461 | } | |
462 | ||
463 | /* Dumps information about induction variable candidate CAND to FILE. */ | |
464 | ||
465 | extern void dump_cand (FILE *, struct iv_cand *); | |
466 | void | |
467 | dump_cand (FILE *file, struct iv_cand *cand) | |
468 | { | |
469 | struct iv *iv = cand->iv; | |
470 | ||
471 | fprintf (file, "candidate %d%s\n", | |
472 | cand->id, cand->important ? " (important)" : ""); | |
473 | ||
474 | if (!iv) | |
475 | { | |
476 | fprintf (file, " final value replacement\n"); | |
477 | return; | |
478 | } | |
479 | ||
480 | switch (cand->pos) | |
481 | { | |
482 | case IP_NORMAL: | |
483 | fprintf (file, " incremented before exit test\n"); | |
484 | break; | |
485 | ||
486 | case IP_END: | |
487 | fprintf (file, " incremented at end\n"); | |
488 | break; | |
489 | ||
490 | case IP_ORIGINAL: | |
491 | fprintf (file, " original biv\n"); | |
492 | break; | |
493 | } | |
494 | ||
e6845c23 | 495 | dump_iv (file, iv); |
8b11a64c ZD |
496 | } |
497 | ||
498 | /* Returns the info for ssa version VER. */ | |
499 | ||
500 | static inline struct version_info * | |
501 | ver_info (struct ivopts_data *data, unsigned ver) | |
502 | { | |
503 | return data->version_info + ver; | |
504 | } | |
505 | ||
506 | /* Returns the info for ssa name NAME. */ | |
507 | ||
508 | static inline struct version_info * | |
509 | name_info (struct ivopts_data *data, tree name) | |
510 | { | |
511 | return ver_info (data, SSA_NAME_VERSION (name)); | |
512 | } | |
513 | ||
514 | /* Checks whether there exists number X such that X * B = A, counting modulo | |
515 | 2^BITS. */ | |
516 | ||
517 | static bool | |
518 | divide (unsigned bits, unsigned HOST_WIDE_INT a, unsigned HOST_WIDE_INT b, | |
519 | HOST_WIDE_INT *x) | |
520 | { | |
521 | unsigned HOST_WIDE_INT mask = ~(~(unsigned HOST_WIDE_INT) 0 << (bits - 1) << 1); | |
522 | unsigned HOST_WIDE_INT inv, ex, val; | |
523 | unsigned i; | |
524 | ||
525 | a &= mask; | |
526 | b &= mask; | |
527 | ||
528 | /* First divide the whole equation by 2 as long as possible. */ | |
529 | while (!(a & 1) && !(b & 1)) | |
530 | { | |
531 | a >>= 1; | |
532 | b >>= 1; | |
533 | bits--; | |
534 | mask >>= 1; | |
535 | } | |
536 | ||
537 | if (!(b & 1)) | |
538 | { | |
539 | /* If b is still even, a is odd and there is no such x. */ | |
540 | return false; | |
541 | } | |
542 | ||
543 | /* Find the inverse of b. We compute it as | |
544 | b^(2^(bits - 1) - 1) (mod 2^bits). */ | |
545 | inv = 1; | |
546 | ex = b; | |
547 | for (i = 0; i < bits - 1; i++) | |
548 | { | |
549 | inv = (inv * ex) & mask; | |
550 | ex = (ex * ex) & mask; | |
551 | } | |
552 | ||
553 | val = (a * inv) & mask; | |
554 | ||
1e128c5f | 555 | gcc_assert (((val * b) & mask) == a); |
8b11a64c ZD |
556 | |
557 | if ((val >> (bits - 1)) & 1) | |
558 | val |= ~mask; | |
559 | ||
560 | *x = val; | |
561 | ||
562 | return true; | |
563 | } | |
564 | ||
565 | /* Returns true if STMT is after the place where the IP_NORMAL ivs will be | |
566 | emitted in LOOP. */ | |
567 | ||
568 | static bool | |
569 | stmt_after_ip_normal_pos (struct loop *loop, tree stmt) | |
570 | { | |
571 | basic_block bb = ip_normal_pos (loop), sbb = bb_for_stmt (stmt); | |
572 | ||
1e128c5f | 573 | gcc_assert (bb); |
8b11a64c ZD |
574 | |
575 | if (sbb == loop->latch) | |
576 | return true; | |
577 | ||
578 | if (sbb != bb) | |
579 | return false; | |
580 | ||
581 | return stmt == last_stmt (bb); | |
582 | } | |
583 | ||
584 | /* Returns true if STMT if after the place where the original induction | |
585 | variable CAND is incremented. */ | |
586 | ||
587 | static bool | |
588 | stmt_after_ip_original_pos (struct iv_cand *cand, tree stmt) | |
589 | { | |
590 | basic_block cand_bb = bb_for_stmt (cand->incremented_at); | |
591 | basic_block stmt_bb = bb_for_stmt (stmt); | |
592 | block_stmt_iterator bsi; | |
593 | ||
594 | if (!dominated_by_p (CDI_DOMINATORS, stmt_bb, cand_bb)) | |
595 | return false; | |
596 | ||
597 | if (stmt_bb != cand_bb) | |
598 | return true; | |
599 | ||
600 | /* Scan the block from the end, since the original ivs are usually | |
601 | incremented at the end of the loop body. */ | |
602 | for (bsi = bsi_last (stmt_bb); ; bsi_prev (&bsi)) | |
603 | { | |
604 | if (bsi_stmt (bsi) == cand->incremented_at) | |
605 | return false; | |
606 | if (bsi_stmt (bsi) == stmt) | |
607 | return true; | |
608 | } | |
609 | } | |
610 | ||
611 | /* Returns true if STMT if after the place where the induction variable | |
612 | CAND is incremented in LOOP. */ | |
613 | ||
614 | static bool | |
615 | stmt_after_increment (struct loop *loop, struct iv_cand *cand, tree stmt) | |
616 | { | |
617 | switch (cand->pos) | |
618 | { | |
619 | case IP_END: | |
620 | return false; | |
621 | ||
622 | case IP_NORMAL: | |
623 | return stmt_after_ip_normal_pos (loop, stmt); | |
624 | ||
625 | case IP_ORIGINAL: | |
626 | return stmt_after_ip_original_pos (cand, stmt); | |
627 | ||
628 | default: | |
1e128c5f | 629 | gcc_unreachable (); |
8b11a64c ZD |
630 | } |
631 | } | |
632 | ||
633 | /* Initializes data structures used by the iv optimization pass, stored | |
634 | in DATA. LOOPS is the loop tree. */ | |
635 | ||
636 | static void | |
637 | tree_ssa_iv_optimize_init (struct loops *loops, struct ivopts_data *data) | |
638 | { | |
639 | unsigned i; | |
640 | ||
641 | data->version_info_size = 2 * num_ssa_names; | |
642 | data->version_info = xcalloc (data->version_info_size, | |
643 | sizeof (struct version_info)); | |
644 | data->relevant = BITMAP_XMALLOC (); | |
b1b02be2 | 645 | data->important_candidates = BITMAP_XMALLOC (); |
8b11a64c ZD |
646 | data->max_inv_id = 0; |
647 | ||
648 | for (i = 1; i < loops->num; i++) | |
649 | if (loops->parray[i]) | |
650 | loops->parray[i]->aux = xcalloc (1, sizeof (struct loop_data)); | |
651 | ||
652 | VARRAY_GENERIC_PTR_NOGC_INIT (data->iv_uses, 20, "iv_uses"); | |
653 | VARRAY_GENERIC_PTR_NOGC_INIT (data->iv_candidates, 20, "iv_candidates"); | |
654 | VARRAY_GENERIC_PTR_NOGC_INIT (decl_rtl_to_reset, 20, "decl_rtl_to_reset"); | |
655 | } | |
656 | ||
e6845c23 ZD |
657 | /* Returns a memory object to that EXPR points. In case we are able to |
658 | determine that it does not point to any such object, NULL is returned. */ | |
659 | ||
660 | static tree | |
661 | determine_base_object (tree expr) | |
662 | { | |
663 | enum tree_code code = TREE_CODE (expr); | |
664 | tree base, obj, op0, op1; | |
665 | ||
666 | if (!POINTER_TYPE_P (TREE_TYPE (expr))) | |
667 | return NULL_TREE; | |
668 | ||
669 | switch (code) | |
670 | { | |
671 | case INTEGER_CST: | |
672 | return NULL_TREE; | |
673 | ||
674 | case ADDR_EXPR: | |
675 | obj = TREE_OPERAND (expr, 0); | |
676 | base = get_base_address (obj); | |
677 | ||
678 | if (!base) | |
679 | return fold_convert (ptr_type_node, expr); | |
680 | ||
7299dbfb ZD |
681 | if (TREE_CODE (base) == INDIRECT_REF) |
682 | return fold_convert (ptr_type_node, TREE_OPERAND (base, 0)); | |
683 | ||
e6845c23 ZD |
684 | return fold (build1 (ADDR_EXPR, ptr_type_node, base)); |
685 | ||
686 | case PLUS_EXPR: | |
687 | case MINUS_EXPR: | |
688 | op0 = determine_base_object (TREE_OPERAND (expr, 0)); | |
689 | op1 = determine_base_object (TREE_OPERAND (expr, 1)); | |
690 | ||
691 | if (!op1) | |
692 | return op0; | |
693 | ||
694 | if (!op0) | |
695 | return (code == PLUS_EXPR | |
696 | ? op1 | |
697 | : fold (build1 (NEGATE_EXPR, ptr_type_node, op1))); | |
698 | ||
699 | return fold (build (code, ptr_type_node, op0, op1)); | |
700 | ||
701 | default: | |
702 | return fold_convert (ptr_type_node, expr); | |
703 | } | |
704 | } | |
705 | ||
8b11a64c ZD |
706 | /* Allocates an induction variable with given initial value BASE and step STEP |
707 | for loop LOOP. */ | |
708 | ||
709 | static struct iv * | |
710 | alloc_iv (tree base, tree step) | |
711 | { | |
712 | struct iv *iv = xcalloc (1, sizeof (struct iv)); | |
713 | ||
714 | if (step && integer_zerop (step)) | |
715 | step = NULL_TREE; | |
716 | ||
717 | iv->base = base; | |
e6845c23 | 718 | iv->base_object = determine_base_object (base); |
8b11a64c ZD |
719 | iv->step = step; |
720 | iv->biv_p = false; | |
721 | iv->have_use_for = false; | |
722 | iv->use_id = 0; | |
723 | iv->ssa_name = NULL_TREE; | |
724 | ||
725 | return iv; | |
726 | } | |
727 | ||
728 | /* Sets STEP and BASE for induction variable IV. */ | |
729 | ||
730 | static void | |
731 | set_iv (struct ivopts_data *data, tree iv, tree base, tree step) | |
732 | { | |
733 | struct version_info *info = name_info (data, iv); | |
734 | ||
1e128c5f | 735 | gcc_assert (!info->iv); |
8b11a64c ZD |
736 | |
737 | bitmap_set_bit (data->relevant, SSA_NAME_VERSION (iv)); | |
738 | info->iv = alloc_iv (base, step); | |
739 | info->iv->ssa_name = iv; | |
740 | } | |
741 | ||
742 | /* Finds induction variable declaration for VAR. */ | |
743 | ||
744 | static struct iv * | |
745 | get_iv (struct ivopts_data *data, tree var) | |
746 | { | |
747 | basic_block bb; | |
748 | ||
749 | if (!name_info (data, var)->iv) | |
750 | { | |
751 | bb = bb_for_stmt (SSA_NAME_DEF_STMT (var)); | |
752 | ||
753 | if (!bb | |
754 | || !flow_bb_inside_loop_p (data->current_loop, bb)) | |
755 | set_iv (data, var, var, NULL_TREE); | |
756 | } | |
757 | ||
758 | return name_info (data, var)->iv; | |
759 | } | |
760 | ||
761 | /* Determines the step of a biv defined in PHI. */ | |
762 | ||
763 | static tree | |
764 | determine_biv_step (tree phi) | |
765 | { | |
766 | struct loop *loop = bb_for_stmt (phi)->loop_father; | |
767 | tree name = PHI_RESULT (phi), base, step; | |
768 | tree type = TREE_TYPE (name); | |
769 | ||
770 | if (!is_gimple_reg (name)) | |
771 | return NULL_TREE; | |
772 | ||
773 | if (!simple_iv (loop, phi, name, &base, &step)) | |
774 | return NULL_TREE; | |
775 | ||
776 | if (!step) | |
5212068f | 777 | return build_int_cst (type, 0); |
8b11a64c ZD |
778 | |
779 | return step; | |
780 | } | |
781 | ||
be35cf60 ZD |
782 | /* Returns true if EXP is a ssa name that occurs in an abnormal phi node. */ |
783 | ||
784 | static bool | |
785 | abnormal_ssa_name_p (tree exp) | |
786 | { | |
787 | if (!exp) | |
788 | return false; | |
789 | ||
790 | if (TREE_CODE (exp) != SSA_NAME) | |
791 | return false; | |
792 | ||
793 | return SSA_NAME_OCCURS_IN_ABNORMAL_PHI (exp) != 0; | |
794 | } | |
795 | ||
796 | /* Returns false if BASE or INDEX contains a ssa name that occurs in an | |
8b11a64c ZD |
797 | abnormal phi node. Callback for for_each_index. */ |
798 | ||
799 | static bool | |
be35cf60 | 800 | idx_contains_abnormal_ssa_name_p (tree base, tree *index, |
8b11a64c ZD |
801 | void *data ATTRIBUTE_UNUSED) |
802 | { | |
be35cf60 ZD |
803 | if (TREE_CODE (base) == ARRAY_REF) |
804 | { | |
805 | if (abnormal_ssa_name_p (TREE_OPERAND (base, 2))) | |
806 | return false; | |
807 | if (abnormal_ssa_name_p (TREE_OPERAND (base, 3))) | |
808 | return false; | |
809 | } | |
8b11a64c | 810 | |
be35cf60 | 811 | return !abnormal_ssa_name_p (*index); |
8b11a64c ZD |
812 | } |
813 | ||
814 | /* Returns true if EXPR contains a ssa name that occurs in an | |
815 | abnormal phi node. */ | |
816 | ||
817 | static bool | |
818 | contains_abnormal_ssa_name_p (tree expr) | |
819 | { | |
820 | enum tree_code code = TREE_CODE (expr); | |
6615c446 | 821 | enum tree_code_class class = TREE_CODE_CLASS (code); |
8b11a64c ZD |
822 | |
823 | if (code == SSA_NAME) | |
824 | return SSA_NAME_OCCURS_IN_ABNORMAL_PHI (expr) != 0; | |
825 | ||
826 | if (code == INTEGER_CST | |
827 | || is_gimple_min_invariant (expr)) | |
828 | return false; | |
829 | ||
830 | if (code == ADDR_EXPR) | |
831 | return !for_each_index (&TREE_OPERAND (expr, 1), | |
832 | idx_contains_abnormal_ssa_name_p, | |
833 | NULL); | |
834 | ||
835 | switch (class) | |
836 | { | |
6615c446 JO |
837 | case tcc_binary: |
838 | case tcc_comparison: | |
8b11a64c ZD |
839 | if (contains_abnormal_ssa_name_p (TREE_OPERAND (expr, 1))) |
840 | return true; | |
841 | ||
842 | /* Fallthru. */ | |
6615c446 | 843 | case tcc_unary: |
8b11a64c ZD |
844 | if (contains_abnormal_ssa_name_p (TREE_OPERAND (expr, 0))) |
845 | return true; | |
846 | ||
847 | break; | |
848 | ||
849 | default: | |
1e128c5f | 850 | gcc_unreachable (); |
8b11a64c ZD |
851 | } |
852 | ||
853 | return false; | |
854 | } | |
855 | ||
856 | /* Finds basic ivs. */ | |
857 | ||
858 | static bool | |
859 | find_bivs (struct ivopts_data *data) | |
860 | { | |
861 | tree phi, step, type, base; | |
862 | bool found = false; | |
863 | struct loop *loop = data->current_loop; | |
864 | ||
bb29d951 | 865 | for (phi = phi_nodes (loop->header); phi; phi = PHI_CHAIN (phi)) |
8b11a64c ZD |
866 | { |
867 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (PHI_RESULT (phi))) | |
868 | continue; | |
869 | ||
870 | step = determine_biv_step (phi); | |
871 | ||
872 | if (!step) | |
873 | continue; | |
874 | if (cst_and_fits_in_hwi (step) | |
875 | && int_cst_value (step) == 0) | |
876 | continue; | |
877 | ||
878 | base = PHI_ARG_DEF_FROM_EDGE (phi, loop_preheader_edge (loop)); | |
879 | if (contains_abnormal_ssa_name_p (base)) | |
880 | continue; | |
881 | ||
882 | type = TREE_TYPE (PHI_RESULT (phi)); | |
883 | base = fold_convert (type, base); | |
884 | step = fold_convert (type, step); | |
885 | ||
886 | /* FIXME: We do not handle induction variables whose step does | |
887 | not satisfy cst_and_fits_in_hwi. */ | |
888 | if (!cst_and_fits_in_hwi (step)) | |
889 | continue; | |
890 | ||
891 | set_iv (data, PHI_RESULT (phi), base, step); | |
892 | found = true; | |
893 | } | |
894 | ||
895 | return found; | |
896 | } | |
897 | ||
898 | /* Marks basic ivs. */ | |
899 | ||
900 | static void | |
901 | mark_bivs (struct ivopts_data *data) | |
902 | { | |
903 | tree phi, var; | |
904 | struct iv *iv, *incr_iv; | |
905 | struct loop *loop = data->current_loop; | |
906 | basic_block incr_bb; | |
907 | ||
bb29d951 | 908 | for (phi = phi_nodes (loop->header); phi; phi = PHI_CHAIN (phi)) |
8b11a64c ZD |
909 | { |
910 | iv = get_iv (data, PHI_RESULT (phi)); | |
911 | if (!iv) | |
912 | continue; | |
913 | ||
914 | var = PHI_ARG_DEF_FROM_EDGE (phi, loop_latch_edge (loop)); | |
915 | incr_iv = get_iv (data, var); | |
916 | if (!incr_iv) | |
917 | continue; | |
918 | ||
919 | /* If the increment is in the subloop, ignore it. */ | |
920 | incr_bb = bb_for_stmt (SSA_NAME_DEF_STMT (var)); | |
921 | if (incr_bb->loop_father != data->current_loop | |
922 | || (incr_bb->flags & BB_IRREDUCIBLE_LOOP)) | |
923 | continue; | |
924 | ||
925 | iv->biv_p = true; | |
926 | incr_iv->biv_p = true; | |
927 | } | |
928 | } | |
929 | ||
930 | /* Checks whether STMT defines a linear induction variable and stores its | |
931 | parameters to BASE and STEP. */ | |
932 | ||
933 | static bool | |
934 | find_givs_in_stmt_scev (struct ivopts_data *data, tree stmt, | |
935 | tree *base, tree *step) | |
936 | { | |
937 | tree lhs; | |
938 | struct loop *loop = data->current_loop; | |
939 | ||
940 | *base = NULL_TREE; | |
941 | *step = NULL_TREE; | |
942 | ||
943 | if (TREE_CODE (stmt) != MODIFY_EXPR) | |
944 | return false; | |
945 | ||
946 | lhs = TREE_OPERAND (stmt, 0); | |
947 | if (TREE_CODE (lhs) != SSA_NAME) | |
948 | return false; | |
949 | ||
950 | if (!simple_iv (loop, stmt, TREE_OPERAND (stmt, 1), base, step)) | |
951 | return false; | |
952 | ||
953 | /* FIXME: We do not handle induction variables whose step does | |
954 | not satisfy cst_and_fits_in_hwi. */ | |
955 | if (!zero_p (*step) | |
956 | && !cst_and_fits_in_hwi (*step)) | |
957 | return false; | |
958 | ||
959 | if (contains_abnormal_ssa_name_p (*base)) | |
960 | return false; | |
961 | ||
962 | return true; | |
963 | } | |
964 | ||
965 | /* Finds general ivs in statement STMT. */ | |
966 | ||
967 | static void | |
968 | find_givs_in_stmt (struct ivopts_data *data, tree stmt) | |
969 | { | |
970 | tree base, step; | |
971 | ||
972 | if (!find_givs_in_stmt_scev (data, stmt, &base, &step)) | |
973 | return; | |
974 | ||
975 | set_iv (data, TREE_OPERAND (stmt, 0), base, step); | |
976 | } | |
977 | ||
978 | /* Finds general ivs in basic block BB. */ | |
979 | ||
980 | static void | |
981 | find_givs_in_bb (struct ivopts_data *data, basic_block bb) | |
982 | { | |
983 | block_stmt_iterator bsi; | |
984 | ||
985 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
986 | find_givs_in_stmt (data, bsi_stmt (bsi)); | |
987 | } | |
988 | ||
989 | /* Finds general ivs. */ | |
990 | ||
991 | static void | |
992 | find_givs (struct ivopts_data *data) | |
993 | { | |
994 | struct loop *loop = data->current_loop; | |
995 | basic_block *body = get_loop_body_in_dom_order (loop); | |
996 | unsigned i; | |
997 | ||
998 | for (i = 0; i < loop->num_nodes; i++) | |
999 | find_givs_in_bb (data, body[i]); | |
1000 | free (body); | |
1001 | } | |
1002 | ||
1003 | /* Determine the number of iterations of the current loop. */ | |
1004 | ||
1005 | static void | |
1006 | determine_number_of_iterations (struct ivopts_data *data) | |
1007 | { | |
1008 | struct loop *loop = data->current_loop; | |
1009 | edge exit = single_dom_exit (loop); | |
1010 | ||
1011 | if (!exit) | |
1012 | return; | |
1013 | ||
1014 | number_of_iterations_exit (loop, exit, &loop_data (loop)->niter); | |
1015 | } | |
1016 | ||
1017 | /* For each ssa name defined in LOOP determines whether it is an induction | |
1018 | variable and if so, its initial value and step. */ | |
1019 | ||
1020 | static bool | |
1021 | find_induction_variables (struct ivopts_data *data) | |
1022 | { | |
1023 | unsigned i; | |
1024 | struct loop *loop = data->current_loop; | |
87c476a2 | 1025 | bitmap_iterator bi; |
8b11a64c ZD |
1026 | |
1027 | if (!find_bivs (data)) | |
1028 | return false; | |
1029 | ||
1030 | find_givs (data); | |
1031 | mark_bivs (data); | |
1032 | determine_number_of_iterations (data); | |
1033 | ||
1034 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1035 | { | |
1036 | if (loop_data (loop)->niter.niter) | |
1037 | { | |
1038 | fprintf (dump_file, " number of iterations "); | |
1039 | print_generic_expr (dump_file, loop_data (loop)->niter.niter, | |
1040 | TDF_SLIM); | |
1041 | fprintf (dump_file, "\n"); | |
1042 | ||
1043 | fprintf (dump_file, " may be zero if "); | |
1044 | print_generic_expr (dump_file, loop_data (loop)->niter.may_be_zero, | |
1045 | TDF_SLIM); | |
1046 | fprintf (dump_file, "\n"); | |
1047 | ||
1048 | fprintf (dump_file, " bogus unless "); | |
1049 | print_generic_expr (dump_file, loop_data (loop)->niter.assumptions, | |
1050 | TDF_SLIM); | |
1051 | fprintf (dump_file, "\n"); | |
1052 | fprintf (dump_file, "\n"); | |
1053 | }; | |
1054 | ||
1055 | fprintf (dump_file, "Induction variables:\n\n"); | |
1056 | ||
87c476a2 | 1057 | EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi) |
8b11a64c ZD |
1058 | { |
1059 | if (ver_info (data, i)->iv) | |
1060 | dump_iv (dump_file, ver_info (data, i)->iv); | |
87c476a2 | 1061 | } |
8b11a64c ZD |
1062 | } |
1063 | ||
1064 | return true; | |
1065 | } | |
1066 | ||
1067 | /* Records a use of type USE_TYPE at *USE_P in STMT whose value is IV. */ | |
1068 | ||
1069 | static struct iv_use * | |
1070 | record_use (struct ivopts_data *data, tree *use_p, struct iv *iv, | |
1071 | tree stmt, enum use_type use_type) | |
1072 | { | |
1073 | struct iv_use *use = xcalloc (1, sizeof (struct iv_use)); | |
1074 | ||
1075 | use->id = n_iv_uses (data); | |
1076 | use->type = use_type; | |
1077 | use->iv = iv; | |
1078 | use->stmt = stmt; | |
1079 | use->op_p = use_p; | |
1080 | use->related_cands = BITMAP_XMALLOC (); | |
1081 | ||
e6845c23 ZD |
1082 | /* To avoid showing ssa name in the dumps, if it was not reset by the |
1083 | caller. */ | |
1084 | iv->ssa_name = NULL_TREE; | |
1085 | ||
8b11a64c ZD |
1086 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1087 | dump_use (dump_file, use); | |
1088 | ||
1089 | VARRAY_PUSH_GENERIC_PTR_NOGC (data->iv_uses, use); | |
1090 | ||
1091 | return use; | |
1092 | } | |
1093 | ||
1094 | /* Checks whether OP is a loop-level invariant and if so, records it. | |
1095 | NONLINEAR_USE is true if the invariant is used in a way we do not | |
1096 | handle specially. */ | |
1097 | ||
1098 | static void | |
1099 | record_invariant (struct ivopts_data *data, tree op, bool nonlinear_use) | |
1100 | { | |
1101 | basic_block bb; | |
1102 | struct version_info *info; | |
1103 | ||
1104 | if (TREE_CODE (op) != SSA_NAME | |
1105 | || !is_gimple_reg (op)) | |
1106 | return; | |
1107 | ||
1108 | bb = bb_for_stmt (SSA_NAME_DEF_STMT (op)); | |
1109 | if (bb | |
1110 | && flow_bb_inside_loop_p (data->current_loop, bb)) | |
1111 | return; | |
1112 | ||
1113 | info = name_info (data, op); | |
1114 | info->name = op; | |
1115 | info->has_nonlin_use |= nonlinear_use; | |
1116 | if (!info->inv_id) | |
1117 | info->inv_id = ++data->max_inv_id; | |
1118 | bitmap_set_bit (data->relevant, SSA_NAME_VERSION (op)); | |
1119 | } | |
1120 | ||
1121 | /* Checks whether the use OP is interesting and if so, records it | |
1122 | as TYPE. */ | |
1123 | ||
1124 | static struct iv_use * | |
1125 | find_interesting_uses_outer_or_nonlin (struct ivopts_data *data, tree op, | |
1126 | enum use_type type) | |
1127 | { | |
1128 | struct iv *iv; | |
1129 | struct iv *civ; | |
1130 | tree stmt; | |
1131 | struct iv_use *use; | |
1132 | ||
1133 | if (TREE_CODE (op) != SSA_NAME) | |
1134 | return NULL; | |
1135 | ||
1136 | iv = get_iv (data, op); | |
1137 | if (!iv) | |
1138 | return NULL; | |
1139 | ||
1140 | if (iv->have_use_for) | |
1141 | { | |
1142 | use = iv_use (data, iv->use_id); | |
1143 | ||
1e128c5f GB |
1144 | gcc_assert (use->type == USE_NONLINEAR_EXPR |
1145 | || use->type == USE_OUTER); | |
8b11a64c ZD |
1146 | |
1147 | if (type == USE_NONLINEAR_EXPR) | |
1148 | use->type = USE_NONLINEAR_EXPR; | |
1149 | return use; | |
1150 | } | |
1151 | ||
1152 | if (zero_p (iv->step)) | |
1153 | { | |
1154 | record_invariant (data, op, true); | |
1155 | return NULL; | |
1156 | } | |
1157 | iv->have_use_for = true; | |
1158 | ||
1159 | civ = xmalloc (sizeof (struct iv)); | |
1160 | *civ = *iv; | |
1161 | ||
1162 | stmt = SSA_NAME_DEF_STMT (op); | |
1e128c5f GB |
1163 | gcc_assert (TREE_CODE (stmt) == PHI_NODE |
1164 | || TREE_CODE (stmt) == MODIFY_EXPR); | |
8b11a64c ZD |
1165 | |
1166 | use = record_use (data, NULL, civ, stmt, type); | |
1167 | iv->use_id = use->id; | |
1168 | ||
1169 | return use; | |
1170 | } | |
1171 | ||
1172 | /* Checks whether the use OP is interesting and if so, records it. */ | |
1173 | ||
1174 | static struct iv_use * | |
1175 | find_interesting_uses_op (struct ivopts_data *data, tree op) | |
1176 | { | |
1177 | return find_interesting_uses_outer_or_nonlin (data, op, USE_NONLINEAR_EXPR); | |
1178 | } | |
1179 | ||
1180 | /* Records a definition of induction variable OP that is used outside of the | |
1181 | loop. */ | |
1182 | ||
1183 | static struct iv_use * | |
1184 | find_interesting_uses_outer (struct ivopts_data *data, tree op) | |
1185 | { | |
1186 | return find_interesting_uses_outer_or_nonlin (data, op, USE_OUTER); | |
1187 | } | |
1188 | ||
1189 | /* Checks whether the condition *COND_P in STMT is interesting | |
1190 | and if so, records it. */ | |
1191 | ||
1192 | static void | |
1193 | find_interesting_uses_cond (struct ivopts_data *data, tree stmt, tree *cond_p) | |
1194 | { | |
1195 | tree *op0_p; | |
1196 | tree *op1_p; | |
1197 | struct iv *iv0 = NULL, *iv1 = NULL, *civ; | |
1198 | struct iv const_iv; | |
1199 | tree zero = integer_zero_node; | |
1200 | ||
1201 | const_iv.step = NULL_TREE; | |
1202 | ||
1203 | if (integer_zerop (*cond_p) | |
1204 | || integer_nonzerop (*cond_p)) | |
1205 | return; | |
1206 | ||
1207 | if (TREE_CODE (*cond_p) == SSA_NAME) | |
1208 | { | |
1209 | op0_p = cond_p; | |
1210 | op1_p = &zero; | |
1211 | } | |
1212 | else | |
1213 | { | |
1214 | op0_p = &TREE_OPERAND (*cond_p, 0); | |
1215 | op1_p = &TREE_OPERAND (*cond_p, 1); | |
1216 | } | |
1217 | ||
1218 | if (TREE_CODE (*op0_p) == SSA_NAME) | |
1219 | iv0 = get_iv (data, *op0_p); | |
1220 | else | |
1221 | iv0 = &const_iv; | |
1222 | ||
1223 | if (TREE_CODE (*op1_p) == SSA_NAME) | |
1224 | iv1 = get_iv (data, *op1_p); | |
1225 | else | |
1226 | iv1 = &const_iv; | |
1227 | ||
1228 | if (/* When comparing with non-invariant value, we may not do any senseful | |
1229 | induction variable elimination. */ | |
1230 | (!iv0 || !iv1) | |
1231 | /* Eliminating condition based on two ivs would be nontrivial. | |
1232 | ??? TODO -- it is not really important to handle this case. */ | |
1233 | || (!zero_p (iv0->step) && !zero_p (iv1->step))) | |
1234 | { | |
1235 | find_interesting_uses_op (data, *op0_p); | |
1236 | find_interesting_uses_op (data, *op1_p); | |
1237 | return; | |
1238 | } | |
1239 | ||
1240 | if (zero_p (iv0->step) && zero_p (iv1->step)) | |
1241 | { | |
1242 | /* If both are invariants, this is a work for unswitching. */ | |
1243 | return; | |
1244 | } | |
1245 | ||
1246 | civ = xmalloc (sizeof (struct iv)); | |
1247 | *civ = zero_p (iv0->step) ? *iv1: *iv0; | |
1248 | record_use (data, cond_p, civ, stmt, USE_COMPARE); | |
1249 | } | |
1250 | ||
be35cf60 ZD |
1251 | /* Returns true if expression EXPR is obviously invariant in LOOP, |
1252 | i.e. if all its operands are defined outside of the LOOP. */ | |
1253 | ||
feb075f4 | 1254 | bool |
be35cf60 ZD |
1255 | expr_invariant_in_loop_p (struct loop *loop, tree expr) |
1256 | { | |
1257 | basic_block def_bb; | |
1258 | unsigned i, len; | |
1259 | ||
1260 | if (is_gimple_min_invariant (expr)) | |
1261 | return true; | |
1262 | ||
1263 | if (TREE_CODE (expr) == SSA_NAME) | |
1264 | { | |
1265 | def_bb = bb_for_stmt (SSA_NAME_DEF_STMT (expr)); | |
1266 | if (def_bb | |
1267 | && flow_bb_inside_loop_p (loop, def_bb)) | |
1268 | return false; | |
1269 | ||
1270 | return true; | |
1271 | } | |
1272 | ||
1273 | if (!EXPR_P (expr)) | |
1274 | return false; | |
1275 | ||
1276 | len = first_rtl_op (TREE_CODE (expr)); | |
1277 | for (i = 0; i < len; i++) | |
1278 | if (!expr_invariant_in_loop_p (loop, TREE_OPERAND (expr, i))) | |
1279 | return false; | |
1280 | ||
1281 | return true; | |
1282 | } | |
1283 | ||
8b11a64c ZD |
1284 | /* Cumulates the steps of indices into DATA and replaces their values with the |
1285 | initial ones. Returns false when the value of the index cannot be determined. | |
1286 | Callback for for_each_index. */ | |
1287 | ||
1288 | struct ifs_ivopts_data | |
1289 | { | |
1290 | struct ivopts_data *ivopts_data; | |
1291 | tree stmt; | |
1292 | tree *step_p; | |
1293 | }; | |
1294 | ||
1295 | static bool | |
1296 | idx_find_step (tree base, tree *idx, void *data) | |
1297 | { | |
1298 | struct ifs_ivopts_data *dta = data; | |
1299 | struct iv *iv; | |
be35cf60 | 1300 | tree step, type, iv_type, iv_step, lbound, off; |
2f4675b4 | 1301 | struct loop *loop = dta->ivopts_data->current_loop; |
be35cf60 ZD |
1302 | |
1303 | if (TREE_CODE (base) == MISALIGNED_INDIRECT_REF | |
1304 | || TREE_CODE (base) == ALIGN_INDIRECT_REF) | |
1305 | return false; | |
1306 | ||
1307 | /* If base is a component ref, require that the offset of the reference | |
1308 | is invariant. */ | |
1309 | if (TREE_CODE (base) == COMPONENT_REF) | |
1310 | { | |
1311 | off = component_ref_field_offset (base); | |
1312 | return expr_invariant_in_loop_p (loop, off); | |
1313 | } | |
1314 | ||
1315 | /* If base is array, first check whether we will be able to move the | |
1316 | reference out of the loop (in order to take its address in strength | |
1317 | reduction). In order for this to work we need both lower bound | |
1318 | and step to be loop invariants. */ | |
1319 | if (TREE_CODE (base) == ARRAY_REF) | |
1320 | { | |
1321 | step = array_ref_element_size (base); | |
1322 | lbound = array_ref_low_bound (base); | |
1323 | ||
1324 | if (!expr_invariant_in_loop_p (loop, step) | |
1325 | || !expr_invariant_in_loop_p (loop, lbound)) | |
1326 | return false; | |
1327 | } | |
1328 | ||
8b11a64c ZD |
1329 | if (TREE_CODE (*idx) != SSA_NAME) |
1330 | return true; | |
1331 | ||
1332 | iv = get_iv (dta->ivopts_data, *idx); | |
1333 | if (!iv) | |
1334 | return false; | |
1335 | ||
1336 | *idx = iv->base; | |
1337 | ||
1338 | if (!iv->step) | |
1339 | return true; | |
1340 | ||
1341 | iv_type = TREE_TYPE (iv->base); | |
1342 | type = build_pointer_type (TREE_TYPE (base)); | |
1343 | if (TREE_CODE (base) == ARRAY_REF) | |
2f4675b4 ZD |
1344 | { |
1345 | step = array_ref_element_size (base); | |
2f4675b4 ZD |
1346 | |
1347 | /* We only handle addresses whose step is an integer constant. */ | |
1348 | if (TREE_CODE (step) != INTEGER_CST) | |
1349 | return false; | |
2f4675b4 | 1350 | } |
8b11a64c | 1351 | else |
5212068f NS |
1352 | /* The step for pointer arithmetics already is 1 byte. */ |
1353 | step = build_int_cst (type, 1); | |
8b11a64c ZD |
1354 | |
1355 | if (TYPE_PRECISION (iv_type) < TYPE_PRECISION (type)) | |
1356 | iv_step = can_count_iv_in_wider_type (dta->ivopts_data->current_loop, | |
1357 | type, iv->base, iv->step, dta->stmt); | |
1358 | else | |
1359 | iv_step = fold_convert (iv_type, iv->step); | |
1360 | ||
1361 | if (!iv_step) | |
1362 | { | |
1363 | /* The index might wrap. */ | |
1364 | return false; | |
1365 | } | |
1366 | ||
1367 | step = EXEC_BINARY (MULT_EXPR, type, step, iv_step); | |
1368 | ||
1369 | if (!*dta->step_p) | |
1370 | *dta->step_p = step; | |
1371 | else | |
1372 | *dta->step_p = EXEC_BINARY (PLUS_EXPR, type, *dta->step_p, step); | |
1373 | ||
1374 | return true; | |
1375 | } | |
1376 | ||
1377 | /* Records use in index IDX. Callback for for_each_index. Ivopts data | |
1378 | object is passed to it in DATA. */ | |
1379 | ||
1380 | static bool | |
2f4675b4 | 1381 | idx_record_use (tree base, tree *idx, |
8b11a64c ZD |
1382 | void *data) |
1383 | { | |
1384 | find_interesting_uses_op (data, *idx); | |
2f4675b4 ZD |
1385 | if (TREE_CODE (base) == ARRAY_REF) |
1386 | { | |
1387 | find_interesting_uses_op (data, array_ref_element_size (base)); | |
1388 | find_interesting_uses_op (data, array_ref_low_bound (base)); | |
1389 | } | |
8b11a64c ZD |
1390 | return true; |
1391 | } | |
1392 | ||
1393 | /* Finds addresses in *OP_P inside STMT. */ | |
1394 | ||
1395 | static void | |
1396 | find_interesting_uses_address (struct ivopts_data *data, tree stmt, tree *op_p) | |
1397 | { | |
1398 | tree base = unshare_expr (*op_p), step = NULL; | |
1399 | struct iv *civ; | |
1400 | struct ifs_ivopts_data ifs_ivopts_data; | |
1401 | ||
1402 | /* Ignore bitfields for now. Not really something terribly complicated | |
1403 | to handle. TODO. */ | |
1404 | if (TREE_CODE (base) == COMPONENT_REF | |
1405 | && DECL_NONADDRESSABLE_P (TREE_OPERAND (base, 1))) | |
1406 | goto fail; | |
1407 | ||
1408 | ifs_ivopts_data.ivopts_data = data; | |
1409 | ifs_ivopts_data.stmt = stmt; | |
1410 | ifs_ivopts_data.step_p = &step; | |
1411 | if (!for_each_index (&base, idx_find_step, &ifs_ivopts_data) | |
1412 | || zero_p (step)) | |
1413 | goto fail; | |
1414 | ||
be35cf60 ZD |
1415 | gcc_assert (TREE_CODE (base) != ALIGN_INDIRECT_REF); |
1416 | gcc_assert (TREE_CODE (base) != MISALIGNED_INDIRECT_REF); | |
1417 | ||
1418 | if (TREE_CODE (base) == INDIRECT_REF) | |
8b11a64c ZD |
1419 | base = TREE_OPERAND (base, 0); |
1420 | else | |
1421 | base = build_addr (base); | |
1422 | ||
1423 | civ = alloc_iv (base, step); | |
1424 | record_use (data, op_p, civ, stmt, USE_ADDRESS); | |
1425 | return; | |
1426 | ||
1427 | fail: | |
1428 | for_each_index (op_p, idx_record_use, data); | |
1429 | } | |
1430 | ||
1431 | /* Finds and records invariants used in STMT. */ | |
1432 | ||
1433 | static void | |
1434 | find_invariants_stmt (struct ivopts_data *data, tree stmt) | |
1435 | { | |
1436 | use_optype uses = NULL; | |
1437 | unsigned i, n; | |
1438 | tree op; | |
1439 | ||
1440 | if (TREE_CODE (stmt) == PHI_NODE) | |
1441 | n = PHI_NUM_ARGS (stmt); | |
1442 | else | |
1443 | { | |
1444 | get_stmt_operands (stmt); | |
1445 | uses = STMT_USE_OPS (stmt); | |
1446 | n = NUM_USES (uses); | |
1447 | } | |
1448 | ||
1449 | for (i = 0; i < n; i++) | |
1450 | { | |
1451 | if (TREE_CODE (stmt) == PHI_NODE) | |
1452 | op = PHI_ARG_DEF (stmt, i); | |
1453 | else | |
1454 | op = USE_OP (uses, i); | |
1455 | ||
1456 | record_invariant (data, op, false); | |
1457 | } | |
1458 | } | |
1459 | ||
1460 | /* Finds interesting uses of induction variables in the statement STMT. */ | |
1461 | ||
1462 | static void | |
1463 | find_interesting_uses_stmt (struct ivopts_data *data, tree stmt) | |
1464 | { | |
1465 | struct iv *iv; | |
1466 | tree op, lhs, rhs; | |
1467 | use_optype uses = NULL; | |
1468 | unsigned i, n; | |
1469 | ||
1470 | find_invariants_stmt (data, stmt); | |
1471 | ||
1472 | if (TREE_CODE (stmt) == COND_EXPR) | |
1473 | { | |
1474 | find_interesting_uses_cond (data, stmt, &COND_EXPR_COND (stmt)); | |
1475 | return; | |
1476 | } | |
1477 | ||
1478 | if (TREE_CODE (stmt) == MODIFY_EXPR) | |
1479 | { | |
1480 | lhs = TREE_OPERAND (stmt, 0); | |
1481 | rhs = TREE_OPERAND (stmt, 1); | |
1482 | ||
1483 | if (TREE_CODE (lhs) == SSA_NAME) | |
1484 | { | |
1485 | /* If the statement defines an induction variable, the uses are not | |
1486 | interesting by themselves. */ | |
1487 | ||
1488 | iv = get_iv (data, lhs); | |
1489 | ||
1490 | if (iv && !zero_p (iv->step)) | |
1491 | return; | |
1492 | } | |
1493 | ||
1494 | switch (TREE_CODE_CLASS (TREE_CODE (rhs))) | |
1495 | { | |
6615c446 | 1496 | case tcc_comparison: |
8b11a64c ZD |
1497 | find_interesting_uses_cond (data, stmt, &TREE_OPERAND (stmt, 1)); |
1498 | return; | |
1499 | ||
6615c446 | 1500 | case tcc_reference: |
8b11a64c | 1501 | find_interesting_uses_address (data, stmt, &TREE_OPERAND (stmt, 1)); |
6615c446 | 1502 | if (REFERENCE_CLASS_P (lhs)) |
8b11a64c ZD |
1503 | find_interesting_uses_address (data, stmt, &TREE_OPERAND (stmt, 0)); |
1504 | return; | |
1505 | ||
1506 | default: ; | |
1507 | } | |
1508 | ||
6615c446 | 1509 | if (REFERENCE_CLASS_P (lhs) |
2f4675b4 | 1510 | && is_gimple_val (rhs)) |
8b11a64c ZD |
1511 | { |
1512 | find_interesting_uses_address (data, stmt, &TREE_OPERAND (stmt, 0)); | |
1513 | find_interesting_uses_op (data, rhs); | |
1514 | return; | |
1515 | } | |
2f4675b4 ZD |
1516 | |
1517 | /* TODO -- we should also handle address uses of type | |
1518 | ||
1519 | memory = call (whatever); | |
1520 | ||
1521 | and | |
1522 | ||
1523 | call (memory). */ | |
8b11a64c ZD |
1524 | } |
1525 | ||
1526 | if (TREE_CODE (stmt) == PHI_NODE | |
1527 | && bb_for_stmt (stmt) == data->current_loop->header) | |
1528 | { | |
1529 | lhs = PHI_RESULT (stmt); | |
1530 | iv = get_iv (data, lhs); | |
1531 | ||
1532 | if (iv && !zero_p (iv->step)) | |
1533 | return; | |
1534 | } | |
1535 | ||
1536 | if (TREE_CODE (stmt) == PHI_NODE) | |
1537 | n = PHI_NUM_ARGS (stmt); | |
1538 | else | |
1539 | { | |
1540 | uses = STMT_USE_OPS (stmt); | |
1541 | n = NUM_USES (uses); | |
1542 | } | |
1543 | ||
1544 | for (i = 0; i < n; i++) | |
1545 | { | |
1546 | if (TREE_CODE (stmt) == PHI_NODE) | |
1547 | op = PHI_ARG_DEF (stmt, i); | |
1548 | else | |
1549 | op = USE_OP (uses, i); | |
1550 | ||
1551 | if (TREE_CODE (op) != SSA_NAME) | |
1552 | continue; | |
1553 | ||
1554 | iv = get_iv (data, op); | |
1555 | if (!iv) | |
1556 | continue; | |
1557 | ||
1558 | find_interesting_uses_op (data, op); | |
1559 | } | |
1560 | } | |
1561 | ||
1562 | /* Finds interesting uses of induction variables outside of loops | |
1563 | on loop exit edge EXIT. */ | |
1564 | ||
1565 | static void | |
1566 | find_interesting_uses_outside (struct ivopts_data *data, edge exit) | |
1567 | { | |
1568 | tree phi, def; | |
1569 | ||
bb29d951 | 1570 | for (phi = phi_nodes (exit->dest); phi; phi = PHI_CHAIN (phi)) |
8b11a64c ZD |
1571 | { |
1572 | def = PHI_ARG_DEF_FROM_EDGE (phi, exit); | |
1573 | find_interesting_uses_outer (data, def); | |
1574 | } | |
1575 | } | |
1576 | ||
1577 | /* Finds uses of the induction variables that are interesting. */ | |
1578 | ||
1579 | static void | |
1580 | find_interesting_uses (struct ivopts_data *data) | |
1581 | { | |
1582 | basic_block bb; | |
1583 | block_stmt_iterator bsi; | |
1584 | tree phi; | |
1585 | basic_block *body = get_loop_body (data->current_loop); | |
1586 | unsigned i; | |
1587 | struct version_info *info; | |
1588 | edge e; | |
1589 | ||
1590 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1591 | fprintf (dump_file, "Uses:\n\n"); | |
1592 | ||
1593 | for (i = 0; i < data->current_loop->num_nodes; i++) | |
1594 | { | |
628f6a4e | 1595 | edge_iterator ei; |
8b11a64c ZD |
1596 | bb = body[i]; |
1597 | ||
628f6a4e | 1598 | FOR_EACH_EDGE (e, ei, bb->succs) |
8b11a64c ZD |
1599 | if (e->dest != EXIT_BLOCK_PTR |
1600 | && !flow_bb_inside_loop_p (data->current_loop, e->dest)) | |
1601 | find_interesting_uses_outside (data, e); | |
1602 | ||
bb29d951 | 1603 | for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) |
8b11a64c ZD |
1604 | find_interesting_uses_stmt (data, phi); |
1605 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
1606 | find_interesting_uses_stmt (data, bsi_stmt (bsi)); | |
1607 | } | |
1608 | ||
1609 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1610 | { | |
87c476a2 ZD |
1611 | bitmap_iterator bi; |
1612 | ||
8b11a64c ZD |
1613 | fprintf (dump_file, "\n"); |
1614 | ||
87c476a2 | 1615 | EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi) |
8b11a64c ZD |
1616 | { |
1617 | info = ver_info (data, i); | |
1618 | if (info->inv_id) | |
1619 | { | |
1620 | fprintf (dump_file, " "); | |
1621 | print_generic_expr (dump_file, info->name, TDF_SLIM); | |
1622 | fprintf (dump_file, " is invariant (%d)%s\n", | |
1623 | info->inv_id, info->has_nonlin_use ? "" : ", eliminable"); | |
1624 | } | |
87c476a2 | 1625 | } |
8b11a64c ZD |
1626 | |
1627 | fprintf (dump_file, "\n"); | |
1628 | } | |
1629 | ||
1630 | free (body); | |
1631 | } | |
1632 | ||
1633 | /* Adds a candidate BASE + STEP * i. Important field is set to IMPORTANT and | |
1634 | position to POS. If USE is not NULL, the candidate is set as related to | |
1635 | it. If both BASE and STEP are NULL, we add a pseudocandidate for the | |
1636 | replacement of the final value of the iv by a direct computation. */ | |
1637 | ||
1638 | static struct iv_cand * | |
1639 | add_candidate_1 (struct ivopts_data *data, | |
1640 | tree base, tree step, bool important, enum iv_position pos, | |
1641 | struct iv_use *use, tree incremented_at) | |
1642 | { | |
1643 | unsigned i; | |
1644 | struct iv_cand *cand = NULL; | |
1645 | tree type; | |
1646 | ||
1647 | if (base) | |
1648 | { | |
1649 | type = TREE_TYPE (base); | |
1650 | if (!TYPE_UNSIGNED (type)) | |
1651 | { | |
1652 | type = unsigned_type_for (type); | |
1653 | base = fold_convert (type, base); | |
1654 | if (step) | |
1655 | step = fold_convert (type, step); | |
1656 | } | |
1657 | } | |
1658 | ||
1659 | for (i = 0; i < n_iv_cands (data); i++) | |
1660 | { | |
1661 | cand = iv_cand (data, i); | |
1662 | ||
1663 | if (cand->pos != pos) | |
1664 | continue; | |
1665 | ||
1666 | if (cand->incremented_at != incremented_at) | |
1667 | continue; | |
1668 | ||
1669 | if (!cand->iv) | |
1670 | { | |
1671 | if (!base && !step) | |
1672 | break; | |
1673 | ||
1674 | continue; | |
1675 | } | |
1676 | ||
1677 | if (!base && !step) | |
1678 | continue; | |
1679 | ||
1680 | if (!operand_equal_p (base, cand->iv->base, 0)) | |
1681 | continue; | |
1682 | ||
1683 | if (zero_p (cand->iv->step)) | |
1684 | { | |
1685 | if (zero_p (step)) | |
1686 | break; | |
1687 | } | |
1688 | else | |
1689 | { | |
1690 | if (step && operand_equal_p (step, cand->iv->step, 0)) | |
1691 | break; | |
1692 | } | |
1693 | } | |
1694 | ||
1695 | if (i == n_iv_cands (data)) | |
1696 | { | |
1697 | cand = xcalloc (1, sizeof (struct iv_cand)); | |
1698 | cand->id = i; | |
1699 | ||
1700 | if (!base && !step) | |
1701 | cand->iv = NULL; | |
1702 | else | |
1703 | cand->iv = alloc_iv (base, step); | |
1704 | ||
1705 | cand->pos = pos; | |
1706 | if (pos != IP_ORIGINAL && cand->iv) | |
1707 | { | |
1708 | cand->var_before = create_tmp_var_raw (TREE_TYPE (base), "ivtmp"); | |
1709 | cand->var_after = cand->var_before; | |
1710 | } | |
1711 | cand->important = important; | |
1712 | cand->incremented_at = incremented_at; | |
1713 | VARRAY_PUSH_GENERIC_PTR_NOGC (data->iv_candidates, cand); | |
1714 | ||
1715 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1716 | dump_cand (dump_file, cand); | |
1717 | } | |
1718 | ||
1719 | if (important && !cand->important) | |
1720 | { | |
1721 | cand->important = true; | |
1722 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1723 | fprintf (dump_file, "Candidate %d is important\n", cand->id); | |
1724 | } | |
1725 | ||
1726 | if (use) | |
1727 | { | |
1728 | bitmap_set_bit (use->related_cands, i); | |
1729 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1730 | fprintf (dump_file, "Candidate %d is related to use %d\n", | |
1731 | cand->id, use->id); | |
1732 | } | |
1733 | ||
1734 | return cand; | |
1735 | } | |
1736 | ||
1737 | /* Adds a candidate BASE + STEP * i. Important field is set to IMPORTANT and | |
1738 | position to POS. If USE is not NULL, the candidate is set as related to | |
1739 | it. The candidate computation is scheduled on all available positions. */ | |
1740 | ||
1741 | static void | |
1742 | add_candidate (struct ivopts_data *data, | |
1743 | tree base, tree step, bool important, struct iv_use *use) | |
1744 | { | |
1745 | if (ip_normal_pos (data->current_loop)) | |
1746 | add_candidate_1 (data, base, step, important, IP_NORMAL, use, NULL_TREE); | |
1747 | if (ip_end_pos (data->current_loop)) | |
1748 | add_candidate_1 (data, base, step, important, IP_END, use, NULL_TREE); | |
1749 | } | |
1750 | ||
1751 | /* Adds standard iv candidates. */ | |
1752 | ||
1753 | static void | |
1754 | add_standard_iv_candidates (struct ivopts_data *data) | |
1755 | { | |
1756 | /* Add 0 + 1 * iteration candidate. */ | |
1757 | add_candidate (data, | |
8679c649 JH |
1758 | build_int_cst (unsigned_intSI_type_node, 0), |
1759 | build_int_cst (unsigned_intSI_type_node, 1), | |
8b11a64c ZD |
1760 | true, NULL); |
1761 | ||
229031d0 | 1762 | /* The same for a long type if it is still fast enough. */ |
8679c649 JH |
1763 | if (BITS_PER_WORD > 32) |
1764 | add_candidate (data, | |
1765 | build_int_cst (unsigned_intDI_type_node, 0), | |
1766 | build_int_cst (unsigned_intDI_type_node, 1), | |
1767 | true, NULL); | |
8b11a64c ZD |
1768 | } |
1769 | ||
1770 | ||
1771 | /* Adds candidates bases on the old induction variable IV. */ | |
1772 | ||
1773 | static void | |
1774 | add_old_iv_candidates (struct ivopts_data *data, struct iv *iv) | |
1775 | { | |
1776 | tree phi, def; | |
1777 | struct iv_cand *cand; | |
1778 | ||
1779 | add_candidate (data, iv->base, iv->step, true, NULL); | |
1780 | ||
1781 | /* The same, but with initial value zero. */ | |
1782 | add_candidate (data, | |
5212068f | 1783 | build_int_cst (TREE_TYPE (iv->base), 0), |
8b11a64c ZD |
1784 | iv->step, true, NULL); |
1785 | ||
1786 | phi = SSA_NAME_DEF_STMT (iv->ssa_name); | |
1787 | if (TREE_CODE (phi) == PHI_NODE) | |
1788 | { | |
1789 | /* Additionally record the possibility of leaving the original iv | |
1790 | untouched. */ | |
1791 | def = PHI_ARG_DEF_FROM_EDGE (phi, loop_latch_edge (data->current_loop)); | |
1792 | cand = add_candidate_1 (data, | |
1793 | iv->base, iv->step, true, IP_ORIGINAL, NULL, | |
1794 | SSA_NAME_DEF_STMT (def)); | |
1795 | cand->var_before = iv->ssa_name; | |
1796 | cand->var_after = def; | |
1797 | } | |
1798 | } | |
1799 | ||
1800 | /* Adds candidates based on the old induction variables. */ | |
1801 | ||
1802 | static void | |
1803 | add_old_ivs_candidates (struct ivopts_data *data) | |
1804 | { | |
1805 | unsigned i; | |
1806 | struct iv *iv; | |
87c476a2 | 1807 | bitmap_iterator bi; |
8b11a64c | 1808 | |
87c476a2 | 1809 | EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi) |
8b11a64c ZD |
1810 | { |
1811 | iv = ver_info (data, i)->iv; | |
1812 | if (iv && iv->biv_p && !zero_p (iv->step)) | |
1813 | add_old_iv_candidates (data, iv); | |
87c476a2 | 1814 | } |
8b11a64c ZD |
1815 | } |
1816 | ||
1817 | /* Adds candidates based on the value of the induction variable IV and USE. */ | |
1818 | ||
1819 | static void | |
1820 | add_iv_value_candidates (struct ivopts_data *data, | |
1821 | struct iv *iv, struct iv_use *use) | |
1822 | { | |
1823 | add_candidate (data, iv->base, iv->step, false, use); | |
1824 | ||
1825 | /* The same, but with initial value zero. */ | |
5212068f | 1826 | add_candidate (data, build_int_cst (TREE_TYPE (iv->base), 0), |
8b11a64c ZD |
1827 | iv->step, false, use); |
1828 | } | |
1829 | ||
1830 | /* Adds candidates based on the address IV and USE. */ | |
1831 | ||
1832 | static void | |
1833 | add_address_candidates (struct ivopts_data *data, | |
1834 | struct iv *iv, struct iv_use *use) | |
1835 | { | |
1836 | tree base, abase, tmp, *act; | |
1837 | ||
1838 | /* First, the trivial choices. */ | |
1839 | add_iv_value_candidates (data, iv, use); | |
1840 | ||
1841 | /* Second, try removing the COMPONENT_REFs. */ | |
1842 | if (TREE_CODE (iv->base) == ADDR_EXPR) | |
1843 | { | |
1844 | base = TREE_OPERAND (iv->base, 0); | |
1845 | while (TREE_CODE (base) == COMPONENT_REF | |
1846 | || (TREE_CODE (base) == ARRAY_REF | |
1847 | && TREE_CODE (TREE_OPERAND (base, 1)) == INTEGER_CST)) | |
1848 | base = TREE_OPERAND (base, 0); | |
1849 | ||
1850 | if (base != TREE_OPERAND (iv->base, 0)) | |
1851 | { | |
be35cf60 ZD |
1852 | gcc_assert (TREE_CODE (base) != ALIGN_INDIRECT_REF); |
1853 | gcc_assert (TREE_CODE (base) != MISALIGNED_INDIRECT_REF); | |
1854 | ||
1855 | if (TREE_CODE (base) == INDIRECT_REF) | |
8b11a64c ZD |
1856 | base = TREE_OPERAND (base, 0); |
1857 | else | |
1858 | base = build_addr (base); | |
1859 | add_candidate (data, base, iv->step, false, use); | |
1860 | } | |
1861 | } | |
1862 | ||
1863 | /* Third, try removing the constant offset. */ | |
1864 | abase = iv->base; | |
1865 | while (TREE_CODE (abase) == PLUS_EXPR | |
1866 | && TREE_CODE (TREE_OPERAND (abase, 1)) != INTEGER_CST) | |
1867 | abase = TREE_OPERAND (abase, 0); | |
1868 | /* We found the offset, so make the copy of the non-shared part and | |
1869 | remove it. */ | |
1870 | if (TREE_CODE (abase) == PLUS_EXPR) | |
1871 | { | |
1872 | tmp = iv->base; | |
1873 | act = &base; | |
1874 | ||
1875 | for (tmp = iv->base; tmp != abase; tmp = TREE_OPERAND (tmp, 0)) | |
1876 | { | |
1877 | *act = build2 (PLUS_EXPR, TREE_TYPE (tmp), | |
1878 | NULL_TREE, TREE_OPERAND (tmp, 1)); | |
1879 | act = &TREE_OPERAND (*act, 0); | |
1880 | } | |
1881 | *act = TREE_OPERAND (tmp, 0); | |
1882 | ||
1883 | add_candidate (data, base, iv->step, false, use); | |
1884 | } | |
1885 | } | |
1886 | ||
1887 | /* Possibly adds pseudocandidate for replacing the final value of USE by | |
1888 | a direct computation. */ | |
1889 | ||
1890 | static void | |
1891 | add_iv_outer_candidates (struct ivopts_data *data, struct iv_use *use) | |
1892 | { | |
1893 | struct tree_niter_desc *niter; | |
1894 | struct loop *loop = data->current_loop; | |
1895 | ||
1896 | /* We must know where we exit the loop and how many times does it roll. */ | |
1897 | if (!single_dom_exit (loop)) | |
1898 | return; | |
1899 | ||
1900 | niter = &loop_data (loop)->niter; | |
1901 | if (!niter->niter | |
1902 | || !operand_equal_p (niter->assumptions, boolean_true_node, 0) | |
1903 | || !operand_equal_p (niter->may_be_zero, boolean_false_node, 0)) | |
1904 | return; | |
1905 | ||
1906 | add_candidate_1 (data, NULL, NULL, false, IP_NORMAL, use, NULL_TREE); | |
1907 | } | |
1908 | ||
1909 | /* Adds candidates based on the uses. */ | |
1910 | ||
1911 | static void | |
1912 | add_derived_ivs_candidates (struct ivopts_data *data) | |
1913 | { | |
1914 | unsigned i; | |
1915 | ||
1916 | for (i = 0; i < n_iv_uses (data); i++) | |
1917 | { | |
1918 | struct iv_use *use = iv_use (data, i); | |
1919 | ||
1920 | if (!use) | |
1921 | continue; | |
1922 | ||
1923 | switch (use->type) | |
1924 | { | |
1925 | case USE_NONLINEAR_EXPR: | |
1926 | case USE_COMPARE: | |
1927 | /* Just add the ivs based on the value of the iv used here. */ | |
1928 | add_iv_value_candidates (data, use->iv, use); | |
1929 | break; | |
1930 | ||
1931 | case USE_OUTER: | |
1932 | add_iv_value_candidates (data, use->iv, use); | |
1933 | ||
1934 | /* Additionally, add the pseudocandidate for the possibility to | |
1935 | replace the final value by a direct computation. */ | |
1936 | add_iv_outer_candidates (data, use); | |
1937 | break; | |
1938 | ||
1939 | case USE_ADDRESS: | |
1940 | add_address_candidates (data, use->iv, use); | |
1941 | break; | |
1942 | ||
1943 | default: | |
1e128c5f | 1944 | gcc_unreachable (); |
8b11a64c ZD |
1945 | } |
1946 | } | |
1947 | } | |
1948 | ||
b1b02be2 ZD |
1949 | /* Record important candidates and add them to related_cands bitmaps |
1950 | if needed. */ | |
1951 | ||
1952 | static void | |
1953 | record_important_candidates (struct ivopts_data *data) | |
1954 | { | |
1955 | unsigned i; | |
1956 | struct iv_use *use; | |
1957 | ||
1958 | for (i = 0; i < n_iv_cands (data); i++) | |
1959 | { | |
1960 | struct iv_cand *cand = iv_cand (data, i); | |
1961 | ||
1962 | if (cand->important) | |
1963 | bitmap_set_bit (data->important_candidates, i); | |
1964 | } | |
1965 | ||
1966 | data->consider_all_candidates = (n_iv_cands (data) | |
1967 | <= CONSIDER_ALL_CANDIDATES_BOUND); | |
1968 | ||
1969 | if (data->consider_all_candidates) | |
1970 | { | |
1971 | /* We will not need "related_cands" bitmaps in this case, | |
1972 | so release them to decrease peak memory consumption. */ | |
1973 | for (i = 0; i < n_iv_uses (data); i++) | |
1974 | { | |
1975 | use = iv_use (data, i); | |
1976 | BITMAP_XFREE (use->related_cands); | |
1977 | } | |
1978 | } | |
1979 | else | |
1980 | { | |
1981 | /* Add important candidates to the related_cands bitmaps. */ | |
1982 | for (i = 0; i < n_iv_uses (data); i++) | |
1983 | bitmap_ior_into (iv_use (data, i)->related_cands, | |
1984 | data->important_candidates); | |
1985 | } | |
1986 | } | |
1987 | ||
8b11a64c ZD |
1988 | /* Finds the candidates for the induction variables. */ |
1989 | ||
1990 | static void | |
1991 | find_iv_candidates (struct ivopts_data *data) | |
1992 | { | |
1993 | /* Add commonly used ivs. */ | |
1994 | add_standard_iv_candidates (data); | |
1995 | ||
1996 | /* Add old induction variables. */ | |
1997 | add_old_ivs_candidates (data); | |
1998 | ||
1999 | /* Add induction variables derived from uses. */ | |
2000 | add_derived_ivs_candidates (data); | |
b1b02be2 ZD |
2001 | |
2002 | /* Record the important candidates. */ | |
2003 | record_important_candidates (data); | |
8b11a64c ZD |
2004 | } |
2005 | ||
2006 | /* Allocates the data structure mapping the (use, candidate) pairs to costs. | |
2007 | If consider_all_candidates is true, we use a two-dimensional array, otherwise | |
2008 | we allocate a simple list to every use. */ | |
2009 | ||
2010 | static void | |
2011 | alloc_use_cost_map (struct ivopts_data *data) | |
2012 | { | |
b1b02be2 | 2013 | unsigned i, size, s, j; |
8b11a64c ZD |
2014 | |
2015 | for (i = 0; i < n_iv_uses (data); i++) | |
2016 | { | |
2017 | struct iv_use *use = iv_use (data, i); | |
87c476a2 | 2018 | bitmap_iterator bi; |
8b11a64c ZD |
2019 | |
2020 | if (data->consider_all_candidates) | |
b1b02be2 | 2021 | size = n_iv_cands (data); |
8b11a64c ZD |
2022 | else |
2023 | { | |
b1b02be2 | 2024 | s = 0; |
87c476a2 ZD |
2025 | EXECUTE_IF_SET_IN_BITMAP (use->related_cands, 0, j, bi) |
2026 | { | |
b1b02be2 | 2027 | s++; |
87c476a2 | 2028 | } |
b1b02be2 ZD |
2029 | |
2030 | /* Round up to the power of two, so that moduling by it is fast. */ | |
2031 | for (size = 1; size < s; size <<= 1) | |
2032 | continue; | |
8b11a64c ZD |
2033 | } |
2034 | ||
b1b02be2 | 2035 | use->n_map_members = size; |
8b11a64c ZD |
2036 | use->cost_map = xcalloc (size, sizeof (struct cost_pair)); |
2037 | } | |
2038 | } | |
2039 | ||
2040 | /* Sets cost of (USE, CANDIDATE) pair to COST and record that it depends | |
2041 | on invariants DEPENDS_ON. */ | |
2042 | ||
2043 | static void | |
2044 | set_use_iv_cost (struct ivopts_data *data, | |
2045 | struct iv_use *use, struct iv_cand *cand, unsigned cost, | |
2046 | bitmap depends_on) | |
2047 | { | |
b1b02be2 ZD |
2048 | unsigned i, s; |
2049 | ||
2050 | if (cost == INFTY) | |
8b11a64c | 2051 | { |
b1b02be2 ZD |
2052 | if (depends_on) |
2053 | BITMAP_XFREE (depends_on); | |
2054 | return; | |
8b11a64c ZD |
2055 | } |
2056 | ||
2057 | if (data->consider_all_candidates) | |
2058 | { | |
2059 | use->cost_map[cand->id].cand = cand; | |
2060 | use->cost_map[cand->id].cost = cost; | |
2061 | use->cost_map[cand->id].depends_on = depends_on; | |
2062 | return; | |
2063 | } | |
2064 | ||
b1b02be2 ZD |
2065 | /* n_map_members is a power of two, so this computes modulo. */ |
2066 | s = cand->id & (use->n_map_members - 1); | |
2067 | for (i = s; i < use->n_map_members; i++) | |
2068 | if (!use->cost_map[i].cand) | |
2069 | goto found; | |
2070 | for (i = 0; i < s; i++) | |
2071 | if (!use->cost_map[i].cand) | |
2072 | goto found; | |
2073 | ||
2074 | gcc_unreachable (); | |
8b11a64c | 2075 | |
b1b02be2 ZD |
2076 | found: |
2077 | use->cost_map[i].cand = cand; | |
2078 | use->cost_map[i].cost = cost; | |
2079 | use->cost_map[i].depends_on = depends_on; | |
8b11a64c ZD |
2080 | } |
2081 | ||
b1b02be2 | 2082 | /* Gets cost of (USE, CANDIDATE) pair. */ |
8b11a64c | 2083 | |
b1b02be2 ZD |
2084 | static struct cost_pair * |
2085 | get_use_iv_cost (struct ivopts_data *data, struct iv_use *use, | |
2086 | struct iv_cand *cand) | |
8b11a64c | 2087 | { |
b1b02be2 ZD |
2088 | unsigned i, s; |
2089 | struct cost_pair *ret; | |
8b11a64c ZD |
2090 | |
2091 | if (!cand) | |
b1b02be2 | 2092 | return NULL; |
8b11a64c ZD |
2093 | |
2094 | if (data->consider_all_candidates) | |
8b11a64c | 2095 | { |
b1b02be2 ZD |
2096 | ret = use->cost_map + cand->id; |
2097 | if (!ret->cand) | |
2098 | return NULL; | |
8b11a64c | 2099 | |
b1b02be2 | 2100 | return ret; |
8b11a64c | 2101 | } |
b1b02be2 ZD |
2102 | |
2103 | /* n_map_members is a power of two, so this computes modulo. */ | |
2104 | s = cand->id & (use->n_map_members - 1); | |
2105 | for (i = s; i < use->n_map_members; i++) | |
2106 | if (use->cost_map[i].cand == cand) | |
2107 | return use->cost_map + i; | |
8b11a64c | 2108 | |
b1b02be2 ZD |
2109 | for (i = 0; i < s; i++) |
2110 | if (use->cost_map[i].cand == cand) | |
2111 | return use->cost_map + i; | |
2112 | ||
2113 | return NULL; | |
8b11a64c ZD |
2114 | } |
2115 | ||
2116 | /* Returns estimate on cost of computing SEQ. */ | |
2117 | ||
2118 | static unsigned | |
2119 | seq_cost (rtx seq) | |
2120 | { | |
2121 | unsigned cost = 0; | |
2122 | rtx set; | |
2123 | ||
2124 | for (; seq; seq = NEXT_INSN (seq)) | |
2125 | { | |
2126 | set = single_set (seq); | |
2127 | if (set) | |
2128 | cost += rtx_cost (set, SET); | |
2129 | else | |
2130 | cost++; | |
2131 | } | |
2132 | ||
2133 | return cost; | |
2134 | } | |
2135 | ||
8679c649 JH |
2136 | /* Produce DECL_RTL for object obj so it looks like it is stored in memory. */ |
2137 | static rtx | |
2138 | produce_memory_decl_rtl (tree obj, int *regno) | |
2139 | { | |
2140 | rtx x; | |
2141 | if (!obj) | |
2142 | abort (); | |
2143 | if (TREE_STATIC (obj) || DECL_EXTERNAL (obj)) | |
2144 | { | |
2145 | const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (obj)); | |
2146 | x = gen_rtx_SYMBOL_REF (Pmode, name); | |
2147 | } | |
2148 | else | |
2149 | x = gen_raw_REG (Pmode, (*regno)++); | |
2150 | ||
2151 | return gen_rtx_MEM (DECL_MODE (obj), x); | |
2152 | } | |
2153 | ||
8b11a64c ZD |
2154 | /* Prepares decl_rtl for variables referred in *EXPR_P. Callback for |
2155 | walk_tree. DATA contains the actual fake register number. */ | |
2156 | ||
2157 | static tree | |
2158 | prepare_decl_rtl (tree *expr_p, int *ws, void *data) | |
2159 | { | |
2160 | tree obj = NULL_TREE; | |
2161 | rtx x = NULL_RTX; | |
2162 | int *regno = data; | |
2163 | ||
2164 | switch (TREE_CODE (*expr_p)) | |
2165 | { | |
8679c649 JH |
2166 | case ADDR_EXPR: |
2167 | for (expr_p = &TREE_OPERAND (*expr_p, 0); | |
2168 | (handled_component_p (*expr_p) | |
2169 | || TREE_CODE (*expr_p) == REALPART_EXPR | |
2170 | || TREE_CODE (*expr_p) == IMAGPART_EXPR); | |
2171 | expr_p = &TREE_OPERAND (*expr_p, 0)); | |
2172 | obj = *expr_p; | |
2173 | if (DECL_P (obj)) | |
2174 | x = produce_memory_decl_rtl (obj, regno); | |
2175 | break; | |
2176 | ||
8b11a64c ZD |
2177 | case SSA_NAME: |
2178 | *ws = 0; | |
2179 | obj = SSA_NAME_VAR (*expr_p); | |
2180 | if (!DECL_RTL_SET_P (obj)) | |
2181 | x = gen_raw_REG (DECL_MODE (obj), (*regno)++); | |
2182 | break; | |
2183 | ||
2184 | case VAR_DECL: | |
2185 | case PARM_DECL: | |
2186 | case RESULT_DECL: | |
2187 | *ws = 0; | |
2188 | obj = *expr_p; | |
2189 | ||
2190 | if (DECL_RTL_SET_P (obj)) | |
2191 | break; | |
2192 | ||
2193 | if (DECL_MODE (obj) == BLKmode) | |
8679c649 | 2194 | x = produce_memory_decl_rtl (obj, regno); |
8b11a64c ZD |
2195 | else |
2196 | x = gen_raw_REG (DECL_MODE (obj), (*regno)++); | |
2197 | ||
2198 | break; | |
2199 | ||
2200 | default: | |
2201 | break; | |
2202 | } | |
2203 | ||
2204 | if (x) | |
2205 | { | |
2206 | VARRAY_PUSH_GENERIC_PTR_NOGC (decl_rtl_to_reset, obj); | |
2207 | SET_DECL_RTL (obj, x); | |
2208 | } | |
2209 | ||
2210 | return NULL_TREE; | |
2211 | } | |
2212 | ||
2213 | /* Determines cost of the computation of EXPR. */ | |
2214 | ||
2215 | static unsigned | |
2216 | computation_cost (tree expr) | |
2217 | { | |
2218 | rtx seq, rslt; | |
2219 | tree type = TREE_TYPE (expr); | |
2220 | unsigned cost; | |
2221 | int regno = 0; | |
2222 | ||
2223 | walk_tree (&expr, prepare_decl_rtl, ®no, NULL); | |
2224 | start_sequence (); | |
2225 | rslt = expand_expr (expr, NULL_RTX, TYPE_MODE (type), EXPAND_NORMAL); | |
2226 | seq = get_insns (); | |
2227 | end_sequence (); | |
2228 | ||
2229 | cost = seq_cost (seq); | |
2230 | if (GET_CODE (rslt) == MEM) | |
2231 | cost += address_cost (XEXP (rslt, 0), TYPE_MODE (type)); | |
2232 | ||
2233 | return cost; | |
2234 | } | |
2235 | ||
2236 | /* Returns variable containing the value of candidate CAND at statement AT. */ | |
2237 | ||
2238 | static tree | |
2239 | var_at_stmt (struct loop *loop, struct iv_cand *cand, tree stmt) | |
2240 | { | |
2241 | if (stmt_after_increment (loop, cand, stmt)) | |
2242 | return cand->var_after; | |
2243 | else | |
2244 | return cand->var_before; | |
2245 | } | |
2246 | ||
2247 | /* Determines the expression by that USE is expressed from induction variable | |
2248 | CAND at statement AT in LOOP. */ | |
2249 | ||
2250 | static tree | |
2251 | get_computation_at (struct loop *loop, | |
2252 | struct iv_use *use, struct iv_cand *cand, tree at) | |
2253 | { | |
2f4675b4 ZD |
2254 | tree ubase = use->iv->base; |
2255 | tree ustep = use->iv->step; | |
2256 | tree cbase = cand->iv->base; | |
2257 | tree cstep = cand->iv->step; | |
8b11a64c ZD |
2258 | tree utype = TREE_TYPE (ubase), ctype = TREE_TYPE (cbase); |
2259 | tree uutype; | |
2260 | tree expr, delta; | |
2261 | tree ratio; | |
2262 | unsigned HOST_WIDE_INT ustepi, cstepi; | |
2263 | HOST_WIDE_INT ratioi; | |
2264 | ||
2265 | if (TYPE_PRECISION (utype) > TYPE_PRECISION (ctype)) | |
2266 | { | |
2267 | /* We do not have a precision to express the values of use. */ | |
2268 | return NULL_TREE; | |
2269 | } | |
2270 | ||
2271 | expr = var_at_stmt (loop, cand, at); | |
2272 | ||
2273 | if (TREE_TYPE (expr) != ctype) | |
2274 | { | |
2275 | /* This may happen with the original ivs. */ | |
2276 | expr = fold_convert (ctype, expr); | |
2277 | } | |
2278 | ||
2279 | if (TYPE_UNSIGNED (utype)) | |
2280 | uutype = utype; | |
2281 | else | |
2282 | { | |
2283 | uutype = unsigned_type_for (utype); | |
2284 | ubase = fold_convert (uutype, ubase); | |
2285 | ustep = fold_convert (uutype, ustep); | |
2286 | } | |
2287 | ||
2288 | if (uutype != ctype) | |
2289 | { | |
2290 | expr = fold_convert (uutype, expr); | |
2291 | cbase = fold_convert (uutype, cbase); | |
2292 | cstep = fold_convert (uutype, cstep); | |
2293 | } | |
2294 | ||
2295 | if (!cst_and_fits_in_hwi (cstep) | |
2296 | || !cst_and_fits_in_hwi (ustep)) | |
2297 | return NULL_TREE; | |
2298 | ||
2299 | ustepi = int_cst_value (ustep); | |
2300 | cstepi = int_cst_value (cstep); | |
2301 | ||
2302 | if (!divide (TYPE_PRECISION (uutype), ustepi, cstepi, &ratioi)) | |
2303 | { | |
2304 | /* TODO maybe consider case when ustep divides cstep and the ratio is | |
2305 | a power of 2 (so that the division is fast to execute)? We would | |
2306 | need to be much more careful with overflows etc. then. */ | |
2307 | return NULL_TREE; | |
2308 | } | |
2309 | ||
2310 | /* We may need to shift the value if we are after the increment. */ | |
2311 | if (stmt_after_increment (loop, cand, at)) | |
2312 | cbase = fold (build2 (PLUS_EXPR, uutype, cbase, cstep)); | |
2313 | ||
2314 | /* use = ubase + ratio * (var - cbase). If either cbase is a constant | |
2315 | or |ratio| == 1, it is better to handle this like | |
2316 | ||
2317 | ubase - ratio * cbase + ratio * var. */ | |
2318 | ||
2319 | if (ratioi == 1) | |
2320 | { | |
2321 | delta = fold (build2 (MINUS_EXPR, uutype, ubase, cbase)); | |
2322 | expr = fold (build2 (PLUS_EXPR, uutype, expr, delta)); | |
2323 | } | |
2324 | else if (ratioi == -1) | |
2325 | { | |
2326 | delta = fold (build2 (PLUS_EXPR, uutype, ubase, cbase)); | |
2327 | expr = fold (build2 (MINUS_EXPR, uutype, delta, expr)); | |
2328 | } | |
2329 | else if (TREE_CODE (cbase) == INTEGER_CST) | |
2330 | { | |
2331 | ratio = build_int_cst_type (uutype, ratioi); | |
2332 | delta = fold (build2 (MULT_EXPR, uutype, ratio, cbase)); | |
2333 | delta = fold (build2 (MINUS_EXPR, uutype, ubase, delta)); | |
2334 | expr = fold (build2 (MULT_EXPR, uutype, ratio, expr)); | |
2335 | expr = fold (build2 (PLUS_EXPR, uutype, delta, expr)); | |
2336 | } | |
2337 | else | |
2338 | { | |
2339 | expr = fold (build2 (MINUS_EXPR, uutype, expr, cbase)); | |
2340 | ratio = build_int_cst_type (uutype, ratioi); | |
2341 | expr = fold (build2 (MULT_EXPR, uutype, ratio, expr)); | |
2342 | expr = fold (build2 (PLUS_EXPR, uutype, ubase, expr)); | |
2343 | } | |
2344 | ||
2345 | return fold_convert (utype, expr); | |
2346 | } | |
2347 | ||
2348 | /* Determines the expression by that USE is expressed from induction variable | |
2349 | CAND in LOOP. */ | |
2350 | ||
2351 | static tree | |
2352 | get_computation (struct loop *loop, struct iv_use *use, struct iv_cand *cand) | |
2353 | { | |
2354 | return get_computation_at (loop, use, cand, use->stmt); | |
2355 | } | |
2356 | ||
2357 | /* Strips constant offsets from EXPR and adds them to OFFSET. */ | |
2358 | ||
2359 | static void | |
2360 | strip_offset (tree *expr, unsigned HOST_WIDE_INT *offset) | |
2361 | { | |
2362 | tree op0, op1; | |
2363 | enum tree_code code; | |
2364 | ||
2365 | while (1) | |
2366 | { | |
2367 | if (cst_and_fits_in_hwi (*expr)) | |
2368 | { | |
2369 | *offset += int_cst_value (*expr); | |
2370 | *expr = integer_zero_node; | |
2371 | return; | |
2372 | } | |
2373 | ||
2374 | code = TREE_CODE (*expr); | |
2375 | ||
2376 | if (code != PLUS_EXPR && code != MINUS_EXPR) | |
2377 | return; | |
2378 | ||
2379 | op0 = TREE_OPERAND (*expr, 0); | |
2380 | op1 = TREE_OPERAND (*expr, 1); | |
2381 | ||
2382 | if (cst_and_fits_in_hwi (op1)) | |
2383 | { | |
2384 | if (code == PLUS_EXPR) | |
2385 | *offset += int_cst_value (op1); | |
2386 | else | |
2387 | *offset -= int_cst_value (op1); | |
2388 | ||
2389 | *expr = op0; | |
2390 | continue; | |
2391 | } | |
2392 | ||
2393 | if (code != PLUS_EXPR) | |
2394 | return; | |
2395 | ||
2396 | if (!cst_and_fits_in_hwi (op0)) | |
2397 | return; | |
2398 | ||
2399 | *offset += int_cst_value (op0); | |
2400 | *expr = op1; | |
2401 | } | |
2402 | } | |
2403 | ||
2404 | /* Returns cost of addition in MODE. */ | |
2405 | ||
2406 | static unsigned | |
2407 | add_cost (enum machine_mode mode) | |
2408 | { | |
2409 | static unsigned costs[NUM_MACHINE_MODES]; | |
2410 | rtx seq; | |
2411 | unsigned cost; | |
2412 | ||
2413 | if (costs[mode]) | |
2414 | return costs[mode]; | |
2415 | ||
2416 | start_sequence (); | |
2417 | force_operand (gen_rtx_fmt_ee (PLUS, mode, | |
2418 | gen_raw_REG (mode, FIRST_PSEUDO_REGISTER), | |
2419 | gen_raw_REG (mode, FIRST_PSEUDO_REGISTER + 1)), | |
2420 | NULL_RTX); | |
2421 | seq = get_insns (); | |
2422 | end_sequence (); | |
2423 | ||
2424 | cost = seq_cost (seq); | |
2425 | if (!cost) | |
2426 | cost = 1; | |
2427 | ||
2428 | costs[mode] = cost; | |
2429 | ||
2430 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2431 | fprintf (dump_file, "Addition in %s costs %d\n", | |
2432 | GET_MODE_NAME (mode), cost); | |
2433 | return cost; | |
2434 | } | |
2435 | ||
2436 | /* Entry in a hashtable of already known costs for multiplication. */ | |
2437 | struct mbc_entry | |
2438 | { | |
2439 | HOST_WIDE_INT cst; /* The constant to multiply by. */ | |
2440 | enum machine_mode mode; /* In mode. */ | |
2441 | unsigned cost; /* The cost. */ | |
2442 | }; | |
2443 | ||
2444 | /* Counts hash value for the ENTRY. */ | |
2445 | ||
2446 | static hashval_t | |
2447 | mbc_entry_hash (const void *entry) | |
2448 | { | |
2449 | const struct mbc_entry *e = entry; | |
2450 | ||
2451 | return 57 * (hashval_t) e->mode + (hashval_t) (e->cst % 877); | |
2452 | } | |
2453 | ||
2454 | /* Compares the hash table entries ENTRY1 and ENTRY2. */ | |
2455 | ||
2456 | static int | |
2457 | mbc_entry_eq (const void *entry1, const void *entry2) | |
2458 | { | |
2459 | const struct mbc_entry *e1 = entry1; | |
2460 | const struct mbc_entry *e2 = entry2; | |
2461 | ||
2462 | return (e1->mode == e2->mode | |
2463 | && e1->cst == e2->cst); | |
2464 | } | |
2465 | ||
2466 | /* Returns cost of multiplication by constant CST in MODE. */ | |
2467 | ||
2468 | static unsigned | |
2469 | multiply_by_cost (HOST_WIDE_INT cst, enum machine_mode mode) | |
2470 | { | |
2471 | static htab_t costs; | |
2472 | struct mbc_entry **cached, act; | |
2473 | rtx seq; | |
2474 | unsigned cost; | |
2475 | ||
2476 | if (!costs) | |
2477 | costs = htab_create (100, mbc_entry_hash, mbc_entry_eq, free); | |
2478 | ||
2479 | act.mode = mode; | |
2480 | act.cst = cst; | |
2481 | cached = (struct mbc_entry **) htab_find_slot (costs, &act, INSERT); | |
2482 | if (*cached) | |
2483 | return (*cached)->cost; | |
2484 | ||
2485 | *cached = xmalloc (sizeof (struct mbc_entry)); | |
2486 | (*cached)->mode = mode; | |
2487 | (*cached)->cst = cst; | |
2488 | ||
2489 | start_sequence (); | |
2490 | expand_mult (mode, gen_raw_REG (mode, FIRST_PSEUDO_REGISTER), GEN_INT (cst), | |
2491 | NULL_RTX, 0); | |
2492 | seq = get_insns (); | |
2493 | end_sequence (); | |
2494 | ||
2495 | cost = seq_cost (seq); | |
2496 | ||
2497 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2498 | fprintf (dump_file, "Multiplication by %d in %s costs %d\n", | |
2499 | (int) cst, GET_MODE_NAME (mode), cost); | |
2500 | ||
2501 | (*cached)->cost = cost; | |
2502 | ||
2503 | return cost; | |
2504 | } | |
2505 | ||
2506 | /* Returns cost of address in shape symbol + var + OFFSET + RATIO * index. | |
2507 | If SYMBOL_PRESENT is false, symbol is omitted. If VAR_PRESENT is false, | |
2508 | variable is omitted. The created memory accesses MODE. | |
2509 | ||
2510 | TODO -- there must be some better way. This all is quite crude. */ | |
2511 | ||
2512 | static unsigned | |
2513 | get_address_cost (bool symbol_present, bool var_present, | |
2514 | unsigned HOST_WIDE_INT offset, HOST_WIDE_INT ratio) | |
2515 | { | |
2516 | #define MAX_RATIO 128 | |
2517 | static sbitmap valid_mult; | |
2518 | static HOST_WIDE_INT rat, off; | |
2519 | static HOST_WIDE_INT min_offset, max_offset; | |
2520 | static unsigned costs[2][2][2][2]; | |
2521 | unsigned cost, acost; | |
2522 | rtx seq, addr, base; | |
2523 | bool offset_p, ratio_p; | |
2524 | rtx reg1; | |
2525 | HOST_WIDE_INT s_offset; | |
2526 | unsigned HOST_WIDE_INT mask; | |
2527 | unsigned bits; | |
2528 | ||
2529 | if (!valid_mult) | |
2530 | { | |
2531 | HOST_WIDE_INT i; | |
2532 | ||
2533 | reg1 = gen_raw_REG (Pmode, FIRST_PSEUDO_REGISTER); | |
2534 | ||
2535 | addr = gen_rtx_fmt_ee (PLUS, Pmode, reg1, NULL_RTX); | |
2536 | for (i = 1; i <= 1 << 20; i <<= 1) | |
2537 | { | |
2538 | XEXP (addr, 1) = GEN_INT (i); | |
2539 | if (!memory_address_p (Pmode, addr)) | |
2540 | break; | |
2541 | } | |
2542 | max_offset = i >> 1; | |
2543 | off = max_offset; | |
2544 | ||
2545 | for (i = 1; i <= 1 << 20; i <<= 1) | |
2546 | { | |
2547 | XEXP (addr, 1) = GEN_INT (-i); | |
2548 | if (!memory_address_p (Pmode, addr)) | |
2549 | break; | |
2550 | } | |
2551 | min_offset = -(i >> 1); | |
2552 | ||
2553 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2554 | { | |
2555 | fprintf (dump_file, "get_address_cost:\n"); | |
2556 | fprintf (dump_file, " min offset %d\n", (int) min_offset); | |
2557 | fprintf (dump_file, " max offset %d\n", (int) max_offset); | |
2558 | } | |
2559 | ||
2560 | valid_mult = sbitmap_alloc (2 * MAX_RATIO + 1); | |
2561 | sbitmap_zero (valid_mult); | |
2562 | rat = 1; | |
2563 | addr = gen_rtx_fmt_ee (MULT, Pmode, reg1, NULL_RTX); | |
2564 | for (i = -MAX_RATIO; i <= MAX_RATIO; i++) | |
2565 | { | |
2566 | XEXP (addr, 1) = GEN_INT (i); | |
2567 | if (memory_address_p (Pmode, addr)) | |
2568 | { | |
2569 | SET_BIT (valid_mult, i + MAX_RATIO); | |
2570 | rat = i; | |
2571 | } | |
2572 | } | |
2573 | ||
2574 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2575 | { | |
2576 | fprintf (dump_file, " allowed multipliers:"); | |
2577 | for (i = -MAX_RATIO; i <= MAX_RATIO; i++) | |
2578 | if (TEST_BIT (valid_mult, i + MAX_RATIO)) | |
2579 | fprintf (dump_file, " %d", (int) i); | |
2580 | fprintf (dump_file, "\n"); | |
2581 | fprintf (dump_file, "\n"); | |
2582 | } | |
2583 | } | |
2584 | ||
2585 | bits = GET_MODE_BITSIZE (Pmode); | |
2586 | mask = ~(~(unsigned HOST_WIDE_INT) 0 << (bits - 1) << 1); | |
2587 | offset &= mask; | |
2588 | if ((offset >> (bits - 1) & 1)) | |
2589 | offset |= ~mask; | |
2590 | s_offset = offset; | |
2591 | ||
2592 | cost = 0; | |
a85a9024 UW |
2593 | offset_p = (s_offset != 0 |
2594 | && min_offset <= s_offset && s_offset <= max_offset); | |
8b11a64c ZD |
2595 | ratio_p = (ratio != 1 |
2596 | && -MAX_RATIO <= ratio && ratio <= MAX_RATIO | |
2597 | && TEST_BIT (valid_mult, ratio + MAX_RATIO)); | |
2598 | ||
2599 | if (ratio != 1 && !ratio_p) | |
2600 | cost += multiply_by_cost (ratio, Pmode); | |
2601 | ||
2602 | if (s_offset && !offset_p && !symbol_present) | |
2603 | { | |
2604 | cost += add_cost (Pmode); | |
2605 | var_present = true; | |
2606 | } | |
2607 | ||
2608 | acost = costs[symbol_present][var_present][offset_p][ratio_p]; | |
2609 | if (!acost) | |
2610 | { | |
2611 | acost = 0; | |
2612 | ||
2613 | addr = gen_raw_REG (Pmode, FIRST_PSEUDO_REGISTER); | |
2614 | reg1 = gen_raw_REG (Pmode, FIRST_PSEUDO_REGISTER + 1); | |
2615 | if (ratio_p) | |
2616 | addr = gen_rtx_fmt_ee (MULT, Pmode, addr, GEN_INT (rat)); | |
2617 | ||
a85a9024 | 2618 | if (var_present) |
7299dbfb | 2619 | addr = gen_rtx_fmt_ee (PLUS, Pmode, addr, reg1); |
a85a9024 | 2620 | |
8b11a64c ZD |
2621 | if (symbol_present) |
2622 | { | |
2623 | base = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup ("")); | |
2624 | if (offset_p) | |
2625 | base = gen_rtx_fmt_e (CONST, Pmode, | |
2626 | gen_rtx_fmt_ee (PLUS, Pmode, | |
2627 | base, | |
2628 | GEN_INT (off))); | |
8b11a64c ZD |
2629 | } |
2630 | else if (offset_p) | |
2631 | base = GEN_INT (off); | |
2632 | else | |
2633 | base = NULL_RTX; | |
2634 | ||
2635 | if (base) | |
7299dbfb | 2636 | addr = gen_rtx_fmt_ee (PLUS, Pmode, addr, base); |
8b11a64c ZD |
2637 | |
2638 | start_sequence (); | |
2639 | addr = memory_address (Pmode, addr); | |
2640 | seq = get_insns (); | |
2641 | end_sequence (); | |
2642 | ||
2643 | acost = seq_cost (seq); | |
2644 | acost += address_cost (addr, Pmode); | |
2645 | ||
2646 | if (!acost) | |
2647 | acost = 1; | |
2648 | costs[symbol_present][var_present][offset_p][ratio_p] = acost; | |
2649 | } | |
2650 | ||
2651 | return cost + acost; | |
2652 | } | |
2653 | ||
2654 | /* Records invariants in *EXPR_P. Callback for walk_tree. DATA contains | |
2655 | the bitmap to that we should store it. */ | |
2656 | ||
2657 | static struct ivopts_data *fd_ivopts_data; | |
2658 | static tree | |
2659 | find_depends (tree *expr_p, int *ws ATTRIBUTE_UNUSED, void *data) | |
2660 | { | |
2661 | bitmap *depends_on = data; | |
2662 | struct version_info *info; | |
2663 | ||
2664 | if (TREE_CODE (*expr_p) != SSA_NAME) | |
2665 | return NULL_TREE; | |
2666 | info = name_info (fd_ivopts_data, *expr_p); | |
2667 | ||
2668 | if (!info->inv_id || info->has_nonlin_use) | |
2669 | return NULL_TREE; | |
2670 | ||
2671 | if (!*depends_on) | |
2672 | *depends_on = BITMAP_XMALLOC (); | |
2673 | bitmap_set_bit (*depends_on, info->inv_id); | |
2674 | ||
2675 | return NULL_TREE; | |
2676 | } | |
2677 | ||
7299dbfb | 2678 | /* Estimates cost of forcing EXPR into a variable. DEPENDS_ON is a set of the |
8b11a64c ZD |
2679 | invariants the computation depends on. */ |
2680 | ||
2681 | static unsigned | |
2682 | force_var_cost (struct ivopts_data *data, | |
2683 | tree expr, bitmap *depends_on) | |
2684 | { | |
2685 | static bool costs_initialized = false; | |
2686 | static unsigned integer_cost; | |
2687 | static unsigned symbol_cost; | |
2688 | static unsigned address_cost; | |
7299dbfb ZD |
2689 | tree op0, op1; |
2690 | unsigned cost0, cost1, cost; | |
2691 | enum machine_mode mode; | |
8b11a64c ZD |
2692 | |
2693 | if (!costs_initialized) | |
2694 | { | |
2695 | tree var = create_tmp_var_raw (integer_type_node, "test_var"); | |
2696 | rtx x = gen_rtx_MEM (DECL_MODE (var), | |
2697 | gen_rtx_SYMBOL_REF (Pmode, "test_var")); | |
2698 | tree addr; | |
2699 | tree type = build_pointer_type (integer_type_node); | |
2700 | ||
2701 | integer_cost = computation_cost (build_int_cst_type (integer_type_node, | |
2702 | 2000)); | |
2703 | ||
2704 | SET_DECL_RTL (var, x); | |
2705 | TREE_STATIC (var) = 1; | |
2706 | addr = build1 (ADDR_EXPR, type, var); | |
2707 | symbol_cost = computation_cost (addr) + 1; | |
2708 | ||
2709 | address_cost | |
2710 | = computation_cost (build2 (PLUS_EXPR, type, | |
2711 | addr, | |
2712 | build_int_cst_type (type, 2000))) + 1; | |
2713 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2714 | { | |
2715 | fprintf (dump_file, "force_var_cost:\n"); | |
2716 | fprintf (dump_file, " integer %d\n", (int) integer_cost); | |
2717 | fprintf (dump_file, " symbol %d\n", (int) symbol_cost); | |
2718 | fprintf (dump_file, " address %d\n", (int) address_cost); | |
2719 | fprintf (dump_file, " other %d\n", (int) target_spill_cost); | |
2720 | fprintf (dump_file, "\n"); | |
2721 | } | |
2722 | ||
2723 | costs_initialized = true; | |
2724 | } | |
2725 | ||
2726 | if (depends_on) | |
2727 | { | |
2728 | fd_ivopts_data = data; | |
2729 | walk_tree (&expr, find_depends, depends_on, NULL); | |
2730 | } | |
2731 | ||
2732 | if (SSA_VAR_P (expr)) | |
2733 | return 0; | |
2734 | ||
2735 | if (TREE_INVARIANT (expr)) | |
2736 | { | |
2737 | if (TREE_CODE (expr) == INTEGER_CST) | |
2738 | return integer_cost; | |
2739 | ||
2740 | if (TREE_CODE (expr) == ADDR_EXPR) | |
2741 | { | |
2742 | tree obj = TREE_OPERAND (expr, 0); | |
2743 | ||
2744 | if (TREE_CODE (obj) == VAR_DECL | |
2745 | || TREE_CODE (obj) == PARM_DECL | |
2746 | || TREE_CODE (obj) == RESULT_DECL) | |
2747 | return symbol_cost; | |
2748 | } | |
2749 | ||
2750 | return address_cost; | |
2751 | } | |
2752 | ||
7299dbfb ZD |
2753 | switch (TREE_CODE (expr)) |
2754 | { | |
2755 | case PLUS_EXPR: | |
2756 | case MINUS_EXPR: | |
2757 | case MULT_EXPR: | |
2758 | op0 = TREE_OPERAND (expr, 0); | |
2759 | op1 = TREE_OPERAND (expr, 1); | |
2760 | ||
2761 | if (is_gimple_val (op0)) | |
2762 | cost0 = 0; | |
2763 | else | |
2764 | cost0 = force_var_cost (data, op0, NULL); | |
2765 | ||
2766 | if (is_gimple_val (op1)) | |
2767 | cost1 = 0; | |
2768 | else | |
2769 | cost1 = force_var_cost (data, op1, NULL); | |
2770 | ||
2771 | break; | |
2772 | ||
2773 | default: | |
2774 | /* Just an arbitrary value, FIXME. */ | |
2775 | return target_spill_cost; | |
2776 | } | |
2777 | ||
2778 | mode = TYPE_MODE (TREE_TYPE (expr)); | |
2779 | switch (TREE_CODE (expr)) | |
2780 | { | |
2781 | case PLUS_EXPR: | |
2782 | case MINUS_EXPR: | |
2783 | cost = add_cost (mode); | |
2784 | break; | |
2785 | ||
2786 | case MULT_EXPR: | |
2787 | if (cst_and_fits_in_hwi (op0)) | |
2788 | cost = multiply_by_cost (int_cst_value (op0), mode); | |
2789 | else if (cst_and_fits_in_hwi (op1)) | |
2790 | cost = multiply_by_cost (int_cst_value (op1), mode); | |
2791 | else | |
2792 | return target_spill_cost; | |
2793 | break; | |
2794 | ||
2795 | default: | |
2796 | gcc_unreachable (); | |
2797 | } | |
2798 | ||
2799 | cost += cost0; | |
2800 | cost += cost1; | |
2801 | ||
2802 | /* Bound the cost by target_spill_cost. The parts of complicated | |
2803 | computations often are either loop invariant or at least can | |
2804 | be shared between several iv uses, so letting this grow without | |
2805 | limits would not give reasonable results. */ | |
2806 | return cost < target_spill_cost ? cost : target_spill_cost; | |
8b11a64c ZD |
2807 | } |
2808 | ||
8b11a64c ZD |
2809 | /* Estimates cost of expressing address ADDR as var + symbol + offset. The |
2810 | value of offset is added to OFFSET, SYMBOL_PRESENT and VAR_PRESENT are set | |
2811 | to false if the corresponding part is missing. DEPENDS_ON is a set of the | |
2812 | invariants the computation depends on. */ | |
2813 | ||
2814 | static unsigned | |
2815 | split_address_cost (struct ivopts_data *data, | |
2816 | tree addr, bool *symbol_present, bool *var_present, | |
2817 | unsigned HOST_WIDE_INT *offset, bitmap *depends_on) | |
2818 | { | |
2f4675b4 ZD |
2819 | tree core; |
2820 | HOST_WIDE_INT bitsize; | |
2821 | HOST_WIDE_INT bitpos; | |
2822 | tree toffset; | |
2823 | enum machine_mode mode; | |
2824 | int unsignedp, volatilep; | |
2825 | ||
2826 | core = get_inner_reference (addr, &bitsize, &bitpos, &toffset, &mode, | |
2827 | &unsignedp, &volatilep); | |
8b11a64c | 2828 | |
2f4675b4 ZD |
2829 | if (toffset != 0 |
2830 | || bitpos % BITS_PER_UNIT != 0 | |
2831 | || TREE_CODE (core) != VAR_DECL) | |
8b11a64c ZD |
2832 | { |
2833 | *symbol_present = false; | |
2834 | *var_present = true; | |
2835 | fd_ivopts_data = data; | |
2836 | walk_tree (&addr, find_depends, depends_on, NULL); | |
2837 | return target_spill_cost; | |
2f4675b4 ZD |
2838 | } |
2839 | ||
2840 | *offset += bitpos / BITS_PER_UNIT; | |
8b11a64c ZD |
2841 | if (TREE_STATIC (core) |
2842 | || DECL_EXTERNAL (core)) | |
2843 | { | |
2844 | *symbol_present = true; | |
2845 | *var_present = false; | |
2846 | return 0; | |
2847 | } | |
2848 | ||
2849 | *symbol_present = false; | |
2850 | *var_present = true; | |
2851 | return 0; | |
2852 | } | |
2853 | ||
2854 | /* Estimates cost of expressing difference of addresses E1 - E2 as | |
2855 | var + symbol + offset. The value of offset is added to OFFSET, | |
2856 | SYMBOL_PRESENT and VAR_PRESENT are set to false if the corresponding | |
2857 | part is missing. DEPENDS_ON is a set of the invariants the computation | |
2858 | depends on. */ | |
2859 | ||
2860 | static unsigned | |
2861 | ptr_difference_cost (struct ivopts_data *data, | |
2862 | tree e1, tree e2, bool *symbol_present, bool *var_present, | |
2863 | unsigned HOST_WIDE_INT *offset, bitmap *depends_on) | |
2864 | { | |
2f4675b4 | 2865 | HOST_WIDE_INT diff = 0; |
8b11a64c ZD |
2866 | unsigned cost; |
2867 | ||
1e128c5f | 2868 | gcc_assert (TREE_CODE (e1) == ADDR_EXPR); |
8b11a64c | 2869 | |
7299dbfb | 2870 | if (ptr_difference_const (e1, e2, &diff)) |
8b11a64c ZD |
2871 | { |
2872 | *offset += diff; | |
2873 | *symbol_present = false; | |
2874 | *var_present = false; | |
2875 | return 0; | |
2876 | } | |
2877 | ||
2878 | if (e2 == integer_zero_node) | |
2879 | return split_address_cost (data, TREE_OPERAND (e1, 0), | |
2880 | symbol_present, var_present, offset, depends_on); | |
2881 | ||
2882 | *symbol_present = false; | |
2883 | *var_present = true; | |
2884 | ||
2885 | cost = force_var_cost (data, e1, depends_on); | |
2886 | cost += force_var_cost (data, e2, depends_on); | |
2887 | cost += add_cost (Pmode); | |
2888 | ||
2889 | return cost; | |
2890 | } | |
2891 | ||
2892 | /* Estimates cost of expressing difference E1 - E2 as | |
2893 | var + symbol + offset. The value of offset is added to OFFSET, | |
2894 | SYMBOL_PRESENT and VAR_PRESENT are set to false if the corresponding | |
2895 | part is missing. DEPENDS_ON is a set of the invariants the computation | |
2896 | depends on. */ | |
2897 | ||
2898 | static unsigned | |
2899 | difference_cost (struct ivopts_data *data, | |
2900 | tree e1, tree e2, bool *symbol_present, bool *var_present, | |
2901 | unsigned HOST_WIDE_INT *offset, bitmap *depends_on) | |
2902 | { | |
2903 | unsigned cost; | |
2904 | enum machine_mode mode = TYPE_MODE (TREE_TYPE (e1)); | |
2905 | ||
2906 | strip_offset (&e1, offset); | |
2907 | *offset = -*offset; | |
2908 | strip_offset (&e2, offset); | |
2909 | *offset = -*offset; | |
2910 | ||
2911 | if (TREE_CODE (e1) == ADDR_EXPR) | |
2912 | return ptr_difference_cost (data, e1, e2, symbol_present, var_present, offset, | |
2913 | depends_on); | |
2914 | *symbol_present = false; | |
2915 | ||
2916 | if (operand_equal_p (e1, e2, 0)) | |
2917 | { | |
2918 | *var_present = false; | |
2919 | return 0; | |
2920 | } | |
2921 | *var_present = true; | |
2922 | if (zero_p (e2)) | |
2923 | return force_var_cost (data, e1, depends_on); | |
2924 | ||
2925 | if (zero_p (e1)) | |
2926 | { | |
2927 | cost = force_var_cost (data, e2, depends_on); | |
2928 | cost += multiply_by_cost (-1, mode); | |
2929 | ||
2930 | return cost; | |
2931 | } | |
2932 | ||
2933 | cost = force_var_cost (data, e1, depends_on); | |
2934 | cost += force_var_cost (data, e2, depends_on); | |
2935 | cost += add_cost (mode); | |
2936 | ||
2937 | return cost; | |
2938 | } | |
2939 | ||
2940 | /* Determines the cost of the computation by that USE is expressed | |
2941 | from induction variable CAND. If ADDRESS_P is true, we just need | |
2942 | to create an address from it, otherwise we want to get it into | |
2943 | register. A set of invariants we depend on is stored in | |
2944 | DEPENDS_ON. AT is the statement at that the value is computed. */ | |
2945 | ||
2946 | static unsigned | |
2947 | get_computation_cost_at (struct ivopts_data *data, | |
2948 | struct iv_use *use, struct iv_cand *cand, | |
2949 | bool address_p, bitmap *depends_on, tree at) | |
2950 | { | |
2951 | tree ubase = use->iv->base, ustep = use->iv->step; | |
2952 | tree cbase, cstep; | |
2953 | tree utype = TREE_TYPE (ubase), ctype; | |
2954 | unsigned HOST_WIDE_INT ustepi, cstepi, offset = 0; | |
2955 | HOST_WIDE_INT ratio, aratio; | |
2956 | bool var_present, symbol_present; | |
2957 | unsigned cost = 0, n_sums; | |
2958 | ||
2959 | *depends_on = NULL; | |
2960 | ||
2961 | /* Only consider real candidates. */ | |
2962 | if (!cand->iv) | |
2963 | return INFTY; | |
2964 | ||
2965 | cbase = cand->iv->base; | |
2966 | cstep = cand->iv->step; | |
2967 | ctype = TREE_TYPE (cbase); | |
2968 | ||
2969 | if (TYPE_PRECISION (utype) > TYPE_PRECISION (ctype)) | |
2970 | { | |
2971 | /* We do not have a precision to express the values of use. */ | |
2972 | return INFTY; | |
2973 | } | |
2974 | ||
e6845c23 ZD |
2975 | if (address_p) |
2976 | { | |
2977 | /* Do not try to express address of an object with computation based | |
2978 | on address of a different object. This may cause problems in rtl | |
2979 | level alias analysis (that does not expect this to be happening, | |
2980 | as this is illegal in C), and would be unlikely to be useful | |
2981 | anyway. */ | |
2982 | if (use->iv->base_object | |
2983 | && cand->iv->base_object | |
2984 | && !operand_equal_p (use->iv->base_object, cand->iv->base_object, 0)) | |
2985 | return INFTY; | |
2986 | } | |
2987 | ||
8b11a64c ZD |
2988 | if (!cst_and_fits_in_hwi (ustep) |
2989 | || !cst_and_fits_in_hwi (cstep)) | |
2990 | return INFTY; | |
2991 | ||
2992 | if (TREE_CODE (ubase) == INTEGER_CST | |
2993 | && !cst_and_fits_in_hwi (ubase)) | |
2994 | goto fallback; | |
2995 | ||
2996 | if (TREE_CODE (cbase) == INTEGER_CST | |
2997 | && !cst_and_fits_in_hwi (cbase)) | |
2998 | goto fallback; | |
2999 | ||
3000 | ustepi = int_cst_value (ustep); | |
3001 | cstepi = int_cst_value (cstep); | |
3002 | ||
3003 | if (TYPE_PRECISION (utype) != TYPE_PRECISION (ctype)) | |
3004 | { | |
3005 | /* TODO -- add direct handling of this case. */ | |
3006 | goto fallback; | |
3007 | } | |
3008 | ||
3009 | if (!divide (TYPE_PRECISION (utype), ustepi, cstepi, &ratio)) | |
3010 | return INFTY; | |
3011 | ||
3012 | /* use = ubase + ratio * (var - cbase). If either cbase is a constant | |
3013 | or ratio == 1, it is better to handle this like | |
3014 | ||
3015 | ubase - ratio * cbase + ratio * var | |
3016 | ||
3017 | (also holds in the case ratio == -1, TODO. */ | |
3018 | ||
3019 | if (TREE_CODE (cbase) == INTEGER_CST) | |
3020 | { | |
3021 | offset = - ratio * int_cst_value (cbase); | |
3022 | cost += difference_cost (data, | |
3023 | ubase, integer_zero_node, | |
3024 | &symbol_present, &var_present, &offset, | |
3025 | depends_on); | |
3026 | } | |
3027 | else if (ratio == 1) | |
3028 | { | |
3029 | cost += difference_cost (data, | |
3030 | ubase, cbase, | |
3031 | &symbol_present, &var_present, &offset, | |
3032 | depends_on); | |
3033 | } | |
3034 | else | |
3035 | { | |
3036 | cost += force_var_cost (data, cbase, depends_on); | |
3037 | cost += add_cost (TYPE_MODE (ctype)); | |
3038 | cost += difference_cost (data, | |
3039 | ubase, integer_zero_node, | |
3040 | &symbol_present, &var_present, &offset, | |
3041 | depends_on); | |
3042 | } | |
3043 | ||
3044 | /* If we are after the increment, the value of the candidate is higher by | |
3045 | one iteration. */ | |
3046 | if (stmt_after_increment (data->current_loop, cand, at)) | |
3047 | offset -= ratio * cstepi; | |
3048 | ||
3049 | /* Now the computation is in shape symbol + var1 + const + ratio * var2. | |
3050 | (symbol/var/const parts may be omitted). If we are looking for an address, | |
3051 | find the cost of addressing this. */ | |
3052 | if (address_p) | |
7299dbfb | 3053 | return cost + get_address_cost (symbol_present, var_present, offset, ratio); |
8b11a64c ZD |
3054 | |
3055 | /* Otherwise estimate the costs for computing the expression. */ | |
3056 | aratio = ratio > 0 ? ratio : -ratio; | |
3057 | if (!symbol_present && !var_present && !offset) | |
3058 | { | |
3059 | if (ratio != 1) | |
3060 | cost += multiply_by_cost (ratio, TYPE_MODE (ctype)); | |
3061 | ||
3062 | return cost; | |
3063 | } | |
3064 | ||
3065 | if (aratio != 1) | |
3066 | cost += multiply_by_cost (aratio, TYPE_MODE (ctype)); | |
3067 | ||
3068 | n_sums = 1; | |
3069 | if (var_present | |
3070 | /* Symbol + offset should be compile-time computable. */ | |
3071 | && (symbol_present || offset)) | |
3072 | n_sums++; | |
3073 | ||
3074 | return cost + n_sums * add_cost (TYPE_MODE (ctype)); | |
3075 | ||
3076 | fallback: | |
3077 | { | |
3078 | /* Just get the expression, expand it and measure the cost. */ | |
3079 | tree comp = get_computation_at (data->current_loop, use, cand, at); | |
3080 | ||
3081 | if (!comp) | |
3082 | return INFTY; | |
3083 | ||
3084 | if (address_p) | |
3085 | comp = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (comp)), comp); | |
3086 | ||
3087 | return computation_cost (comp); | |
3088 | } | |
3089 | } | |
3090 | ||
3091 | /* Determines the cost of the computation by that USE is expressed | |
3092 | from induction variable CAND. If ADDRESS_P is true, we just need | |
3093 | to create an address from it, otherwise we want to get it into | |
3094 | register. A set of invariants we depend on is stored in | |
3095 | DEPENDS_ON. */ | |
3096 | ||
3097 | static unsigned | |
3098 | get_computation_cost (struct ivopts_data *data, | |
3099 | struct iv_use *use, struct iv_cand *cand, | |
3100 | bool address_p, bitmap *depends_on) | |
3101 | { | |
3102 | return get_computation_cost_at (data, | |
3103 | use, cand, address_p, depends_on, use->stmt); | |
3104 | } | |
3105 | ||
3106 | /* Determines cost of basing replacement of USE on CAND in a generic | |
3107 | expression. */ | |
3108 | ||
b1b02be2 | 3109 | static bool |
8b11a64c ZD |
3110 | determine_use_iv_cost_generic (struct ivopts_data *data, |
3111 | struct iv_use *use, struct iv_cand *cand) | |
3112 | { | |
3113 | bitmap depends_on; | |
3114 | unsigned cost = get_computation_cost (data, use, cand, false, &depends_on); | |
3115 | ||
3116 | set_use_iv_cost (data, use, cand, cost, depends_on); | |
b1b02be2 ZD |
3117 | |
3118 | return cost != INFTY; | |
8b11a64c ZD |
3119 | } |
3120 | ||
3121 | /* Determines cost of basing replacement of USE on CAND in an address. */ | |
3122 | ||
b1b02be2 | 3123 | static bool |
8b11a64c ZD |
3124 | determine_use_iv_cost_address (struct ivopts_data *data, |
3125 | struct iv_use *use, struct iv_cand *cand) | |
3126 | { | |
3127 | bitmap depends_on; | |
3128 | unsigned cost = get_computation_cost (data, use, cand, true, &depends_on); | |
3129 | ||
3130 | set_use_iv_cost (data, use, cand, cost, depends_on); | |
b1b02be2 ZD |
3131 | |
3132 | return cost != INFTY; | |
8b11a64c ZD |
3133 | } |
3134 | ||
3135 | /* Computes value of induction variable IV in iteration NITER. */ | |
3136 | ||
3137 | static tree | |
3138 | iv_value (struct iv *iv, tree niter) | |
3139 | { | |
3140 | tree val; | |
3141 | tree type = TREE_TYPE (iv->base); | |
3142 | ||
3143 | niter = fold_convert (type, niter); | |
2f4675b4 | 3144 | val = fold (build2 (MULT_EXPR, type, iv->step, niter)); |
8b11a64c ZD |
3145 | |
3146 | return fold (build2 (PLUS_EXPR, type, iv->base, val)); | |
3147 | } | |
3148 | ||
3149 | /* Computes value of candidate CAND at position AT in iteration NITER. */ | |
3150 | ||
3151 | static tree | |
3152 | cand_value_at (struct loop *loop, struct iv_cand *cand, tree at, tree niter) | |
3153 | { | |
3154 | tree val = iv_value (cand->iv, niter); | |
3155 | tree type = TREE_TYPE (cand->iv->base); | |
3156 | ||
3157 | if (stmt_after_increment (loop, cand, at)) | |
3158 | val = fold (build2 (PLUS_EXPR, type, val, cand->iv->step)); | |
3159 | ||
3160 | return val; | |
3161 | } | |
3162 | ||
3163 | /* Check whether it is possible to express the condition in USE by comparison | |
3164 | of candidate CAND. If so, store the comparison code to COMPARE and the | |
3165 | value compared with to BOUND. */ | |
3166 | ||
3167 | static bool | |
3168 | may_eliminate_iv (struct loop *loop, | |
3169 | struct iv_use *use, struct iv_cand *cand, | |
3170 | enum tree_code *compare, tree *bound) | |
3171 | { | |
e6845c23 | 3172 | basic_block ex_bb; |
8b11a64c | 3173 | edge exit; |
e6845c23 | 3174 | struct tree_niter_desc niter, new_niter; |
8b11a64c | 3175 | tree wider_type, type, base; |
e6845c23 ZD |
3176 | |
3177 | /* For now works only for exits that dominate the loop latch. TODO -- extend | |
3178 | for other conditions inside loop body. */ | |
3179 | ex_bb = bb_for_stmt (use->stmt); | |
3180 | if (use->stmt != last_stmt (ex_bb) | |
3181 | || TREE_CODE (use->stmt) != COND_EXPR) | |
8b11a64c | 3182 | return false; |
e6845c23 | 3183 | if (!dominated_by_p (CDI_DOMINATORS, loop->latch, ex_bb)) |
8b11a64c ZD |
3184 | return false; |
3185 | ||
e6845c23 ZD |
3186 | exit = EDGE_SUCC (ex_bb, 0); |
3187 | if (flow_bb_inside_loop_p (loop, exit->dest)) | |
3188 | exit = EDGE_SUCC (ex_bb, 1); | |
3189 | if (flow_bb_inside_loop_p (loop, exit->dest)) | |
3190 | return false; | |
3191 | ||
3192 | niter.niter = NULL_TREE; | |
3193 | number_of_iterations_exit (loop, exit, &niter); | |
3194 | if (!niter.niter | |
3195 | || !integer_nonzerop (niter.assumptions) | |
3196 | || !integer_zerop (niter.may_be_zero)) | |
8b11a64c ZD |
3197 | return false; |
3198 | ||
3199 | if (exit->flags & EDGE_TRUE_VALUE) | |
3200 | *compare = EQ_EXPR; | |
3201 | else | |
3202 | *compare = NE_EXPR; | |
3203 | ||
e6845c23 | 3204 | *bound = cand_value_at (loop, cand, use->stmt, niter.niter); |
8b11a64c ZD |
3205 | |
3206 | /* Let us check there is not some problem with overflows, by checking that | |
3207 | the number of iterations is unchanged. */ | |
3208 | base = cand->iv->base; | |
3209 | type = TREE_TYPE (base); | |
3210 | if (stmt_after_increment (loop, cand, use->stmt)) | |
3211 | base = fold (build2 (PLUS_EXPR, type, base, cand->iv->step)); | |
3212 | ||
3213 | new_niter.niter = NULL_TREE; | |
3214 | number_of_iterations_cond (TREE_TYPE (cand->iv->base), base, | |
3215 | cand->iv->step, NE_EXPR, *bound, NULL_TREE, | |
3216 | &new_niter); | |
3217 | if (!new_niter.niter | |
3218 | || !integer_nonzerop (new_niter.assumptions) | |
3219 | || !integer_zerop (new_niter.may_be_zero)) | |
3220 | return false; | |
3221 | ||
3222 | wider_type = TREE_TYPE (new_niter.niter); | |
e6845c23 ZD |
3223 | if (TYPE_PRECISION (wider_type) < TYPE_PRECISION (TREE_TYPE (niter.niter))) |
3224 | wider_type = TREE_TYPE (niter.niter); | |
3225 | if (!operand_equal_p (fold_convert (wider_type, niter.niter), | |
8b11a64c ZD |
3226 | fold_convert (wider_type, new_niter.niter), 0)) |
3227 | return false; | |
3228 | ||
3229 | return true; | |
3230 | } | |
3231 | ||
3232 | /* Determines cost of basing replacement of USE on CAND in a condition. */ | |
3233 | ||
b1b02be2 | 3234 | static bool |
8b11a64c ZD |
3235 | determine_use_iv_cost_condition (struct ivopts_data *data, |
3236 | struct iv_use *use, struct iv_cand *cand) | |
3237 | { | |
3238 | tree bound; | |
3239 | enum tree_code compare; | |
3240 | ||
3241 | /* Only consider real candidates. */ | |
3242 | if (!cand->iv) | |
3243 | { | |
3244 | set_use_iv_cost (data, use, cand, INFTY, NULL); | |
b1b02be2 | 3245 | return false; |
8b11a64c ZD |
3246 | } |
3247 | ||
3248 | if (may_eliminate_iv (data->current_loop, use, cand, &compare, &bound)) | |
3249 | { | |
3250 | bitmap depends_on = NULL; | |
3251 | unsigned cost = force_var_cost (data, bound, &depends_on); | |
3252 | ||
3253 | set_use_iv_cost (data, use, cand, cost, depends_on); | |
b1b02be2 | 3254 | return cost != INFTY; |
8b11a64c ZD |
3255 | } |
3256 | ||
3257 | /* The induction variable elimination failed; just express the original | |
3258 | giv. If it is compared with an invariant, note that we cannot get | |
3259 | rid of it. */ | |
3260 | if (TREE_CODE (*use->op_p) == SSA_NAME) | |
3261 | record_invariant (data, *use->op_p, true); | |
3262 | else | |
3263 | { | |
3264 | record_invariant (data, TREE_OPERAND (*use->op_p, 0), true); | |
3265 | record_invariant (data, TREE_OPERAND (*use->op_p, 1), true); | |
3266 | } | |
3267 | ||
b1b02be2 | 3268 | return determine_use_iv_cost_generic (data, use, cand); |
8b11a64c ZD |
3269 | } |
3270 | ||
3271 | /* Checks whether it is possible to replace the final value of USE by | |
3272 | a direct computation. If so, the formula is stored to *VALUE. */ | |
3273 | ||
3274 | static bool | |
3275 | may_replace_final_value (struct loop *loop, struct iv_use *use, tree *value) | |
3276 | { | |
3277 | edge exit; | |
3278 | struct tree_niter_desc *niter; | |
3279 | ||
3280 | exit = single_dom_exit (loop); | |
3281 | if (!exit) | |
3282 | return false; | |
3283 | ||
1e128c5f GB |
3284 | gcc_assert (dominated_by_p (CDI_DOMINATORS, exit->src, |
3285 | bb_for_stmt (use->stmt))); | |
8b11a64c ZD |
3286 | |
3287 | niter = &loop_data (loop)->niter; | |
3288 | if (!niter->niter | |
3289 | || !operand_equal_p (niter->assumptions, boolean_true_node, 0) | |
3290 | || !operand_equal_p (niter->may_be_zero, boolean_false_node, 0)) | |
3291 | return false; | |
3292 | ||
3293 | *value = iv_value (use->iv, niter->niter); | |
3294 | ||
3295 | return true; | |
3296 | } | |
3297 | ||
3298 | /* Determines cost of replacing final value of USE using CAND. */ | |
3299 | ||
b1b02be2 | 3300 | static bool |
8b11a64c ZD |
3301 | determine_use_iv_cost_outer (struct ivopts_data *data, |
3302 | struct iv_use *use, struct iv_cand *cand) | |
3303 | { | |
3304 | bitmap depends_on; | |
3305 | unsigned cost; | |
3306 | edge exit; | |
3307 | tree value; | |
3308 | struct loop *loop = data->current_loop; | |
3309 | ||
3310 | if (!cand->iv) | |
3311 | { | |
3312 | if (!may_replace_final_value (loop, use, &value)) | |
3313 | { | |
3314 | set_use_iv_cost (data, use, cand, INFTY, NULL); | |
b1b02be2 | 3315 | return false; |
8b11a64c ZD |
3316 | } |
3317 | ||
3318 | depends_on = NULL; | |
3319 | cost = force_var_cost (data, value, &depends_on); | |
3320 | ||
3321 | cost /= AVG_LOOP_NITER (loop); | |
3322 | ||
3323 | set_use_iv_cost (data, use, cand, cost, depends_on); | |
b1b02be2 | 3324 | return cost != INFTY; |
8b11a64c ZD |
3325 | } |
3326 | ||
3327 | exit = single_dom_exit (loop); | |
3328 | if (exit) | |
3329 | { | |
3330 | /* If there is just a single exit, we may use value of the candidate | |
3331 | after we take it to determine the value of use. */ | |
3332 | cost = get_computation_cost_at (data, use, cand, false, &depends_on, | |
3333 | last_stmt (exit->src)); | |
3334 | if (cost != INFTY) | |
3335 | cost /= AVG_LOOP_NITER (loop); | |
3336 | } | |
3337 | else | |
3338 | { | |
3339 | /* Otherwise we just need to compute the iv. */ | |
3340 | cost = get_computation_cost (data, use, cand, false, &depends_on); | |
3341 | } | |
3342 | ||
3343 | set_use_iv_cost (data, use, cand, cost, depends_on); | |
b1b02be2 ZD |
3344 | |
3345 | return cost != INFTY; | |
8b11a64c ZD |
3346 | } |
3347 | ||
b1b02be2 ZD |
3348 | /* Determines cost of basing replacement of USE on CAND. Returns false |
3349 | if USE cannot be based on CAND. */ | |
8b11a64c | 3350 | |
b1b02be2 | 3351 | static bool |
8b11a64c ZD |
3352 | determine_use_iv_cost (struct ivopts_data *data, |
3353 | struct iv_use *use, struct iv_cand *cand) | |
3354 | { | |
3355 | switch (use->type) | |
3356 | { | |
3357 | case USE_NONLINEAR_EXPR: | |
b1b02be2 | 3358 | return determine_use_iv_cost_generic (data, use, cand); |
8b11a64c ZD |
3359 | |
3360 | case USE_OUTER: | |
b1b02be2 | 3361 | return determine_use_iv_cost_outer (data, use, cand); |
8b11a64c ZD |
3362 | |
3363 | case USE_ADDRESS: | |
b1b02be2 | 3364 | return determine_use_iv_cost_address (data, use, cand); |
8b11a64c ZD |
3365 | |
3366 | case USE_COMPARE: | |
b1b02be2 | 3367 | return determine_use_iv_cost_condition (data, use, cand); |
8b11a64c ZD |
3368 | |
3369 | default: | |
1e128c5f | 3370 | gcc_unreachable (); |
8b11a64c ZD |
3371 | } |
3372 | } | |
3373 | ||
3374 | /* Determines costs of basing the use of the iv on an iv candidate. */ | |
3375 | ||
3376 | static void | |
3377 | determine_use_iv_costs (struct ivopts_data *data) | |
3378 | { | |
3379 | unsigned i, j; | |
3380 | struct iv_use *use; | |
3381 | struct iv_cand *cand; | |
b1b02be2 | 3382 | bitmap to_clear = BITMAP_XMALLOC (); |
8b11a64c ZD |
3383 | |
3384 | alloc_use_cost_map (data); | |
3385 | ||
8b11a64c ZD |
3386 | for (i = 0; i < n_iv_uses (data); i++) |
3387 | { | |
3388 | use = iv_use (data, i); | |
3389 | ||
3390 | if (data->consider_all_candidates) | |
3391 | { | |
3392 | for (j = 0; j < n_iv_cands (data); j++) | |
3393 | { | |
3394 | cand = iv_cand (data, j); | |
3395 | determine_use_iv_cost (data, use, cand); | |
3396 | } | |
3397 | } | |
3398 | else | |
3399 | { | |
87c476a2 ZD |
3400 | bitmap_iterator bi; |
3401 | ||
3402 | EXECUTE_IF_SET_IN_BITMAP (use->related_cands, 0, j, bi) | |
8b11a64c ZD |
3403 | { |
3404 | cand = iv_cand (data, j); | |
b1b02be2 ZD |
3405 | if (!determine_use_iv_cost (data, use, cand)) |
3406 | bitmap_set_bit (to_clear, j); | |
87c476a2 | 3407 | } |
b1b02be2 ZD |
3408 | |
3409 | /* Remove the candidates for that the cost is infinite from | |
3410 | the list of related candidates. */ | |
3411 | bitmap_and_compl_into (use->related_cands, to_clear); | |
3412 | bitmap_clear (to_clear); | |
8b11a64c ZD |
3413 | } |
3414 | } | |
3415 | ||
b1b02be2 ZD |
3416 | BITMAP_XFREE (to_clear); |
3417 | ||
8b11a64c ZD |
3418 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3419 | { | |
3420 | fprintf (dump_file, "Use-candidate costs:\n"); | |
3421 | ||
3422 | for (i = 0; i < n_iv_uses (data); i++) | |
3423 | { | |
3424 | use = iv_use (data, i); | |
3425 | ||
3426 | fprintf (dump_file, "Use %d:\n", i); | |
3427 | fprintf (dump_file, " cand\tcost\tdepends on\n"); | |
3428 | for (j = 0; j < use->n_map_members; j++) | |
3429 | { | |
3430 | if (!use->cost_map[j].cand | |
3431 | || use->cost_map[j].cost == INFTY) | |
3432 | continue; | |
3433 | ||
3434 | fprintf (dump_file, " %d\t%d\t", | |
3435 | use->cost_map[j].cand->id, | |
3436 | use->cost_map[j].cost); | |
3437 | if (use->cost_map[j].depends_on) | |
3438 | bitmap_print (dump_file, | |
3439 | use->cost_map[j].depends_on, "",""); | |
3440 | fprintf (dump_file, "\n"); | |
3441 | } | |
3442 | ||
3443 | fprintf (dump_file, "\n"); | |
3444 | } | |
3445 | fprintf (dump_file, "\n"); | |
3446 | } | |
3447 | } | |
3448 | ||
3449 | /* Determines cost of the candidate CAND. */ | |
3450 | ||
3451 | static void | |
3452 | determine_iv_cost (struct ivopts_data *data, struct iv_cand *cand) | |
3453 | { | |
3454 | unsigned cost_base, cost_step; | |
3455 | tree base, last; | |
3456 | basic_block bb; | |
3457 | ||
3458 | if (!cand->iv) | |
3459 | { | |
3460 | cand->cost = 0; | |
3461 | return; | |
3462 | } | |
3463 | ||
3464 | /* There are two costs associated with the candidate -- its increment | |
3465 | and its initialization. The second is almost negligible for any loop | |
3466 | that rolls enough, so we take it just very little into account. */ | |
3467 | ||
3468 | base = cand->iv->base; | |
3469 | cost_base = force_var_cost (data, base, NULL); | |
3470 | cost_step = add_cost (TYPE_MODE (TREE_TYPE (base))); | |
3471 | ||
3472 | cand->cost = cost_step + cost_base / AVG_LOOP_NITER (current_loop); | |
3473 | ||
3474 | /* Prefer the original iv unless we may gain something by replacing it. */ | |
3475 | if (cand->pos == IP_ORIGINAL) | |
3476 | cand->cost--; | |
3477 | ||
3478 | /* Prefer not to insert statements into latch unless there are some | |
3479 | already (so that we do not create unnecessary jumps). */ | |
3480 | if (cand->pos == IP_END) | |
3481 | { | |
3482 | bb = ip_end_pos (data->current_loop); | |
3483 | last = last_stmt (bb); | |
3484 | ||
3485 | if (!last | |
3486 | || TREE_CODE (last) == LABEL_EXPR) | |
3487 | cand->cost++; | |
3488 | } | |
3489 | } | |
3490 | ||
3491 | /* Determines costs of computation of the candidates. */ | |
3492 | ||
3493 | static void | |
3494 | determine_iv_costs (struct ivopts_data *data) | |
3495 | { | |
3496 | unsigned i; | |
3497 | ||
3498 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3499 | { | |
3500 | fprintf (dump_file, "Candidate costs:\n"); | |
3501 | fprintf (dump_file, " cand\tcost\n"); | |
3502 | } | |
3503 | ||
3504 | for (i = 0; i < n_iv_cands (data); i++) | |
3505 | { | |
3506 | struct iv_cand *cand = iv_cand (data, i); | |
3507 | ||
3508 | determine_iv_cost (data, cand); | |
3509 | ||
3510 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3511 | fprintf (dump_file, " %d\t%d\n", i, cand->cost); | |
3512 | } | |
3513 | ||
3514 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3515 | fprintf (dump_file, "\n"); | |
3516 | } | |
3517 | ||
3518 | /* Calculates cost for having SIZE induction variables. */ | |
3519 | ||
3520 | static unsigned | |
3521 | ivopts_global_cost_for_size (struct ivopts_data *data, unsigned size) | |
3522 | { | |
3523 | return global_cost_for_size (size, | |
3524 | loop_data (data->current_loop)->regs_used, | |
3525 | n_iv_uses (data)); | |
3526 | } | |
3527 | ||
3528 | /* For each size of the induction variable set determine the penalty. */ | |
3529 | ||
3530 | static void | |
3531 | determine_set_costs (struct ivopts_data *data) | |
3532 | { | |
3533 | unsigned j, n; | |
3534 | tree phi, op; | |
3535 | struct loop *loop = data->current_loop; | |
87c476a2 | 3536 | bitmap_iterator bi; |
8b11a64c ZD |
3537 | |
3538 | /* We use the following model (definitely improvable, especially the | |
3539 | cost function -- TODO): | |
3540 | ||
3541 | We estimate the number of registers available (using MD data), name it A. | |
3542 | ||
3543 | We estimate the number of registers used by the loop, name it U. This | |
3544 | number is obtained as the number of loop phi nodes (not counting virtual | |
3545 | registers and bivs) + the number of variables from outside of the loop. | |
3546 | ||
3547 | We set a reserve R (free regs that are used for temporary computations, | |
3548 | etc.). For now the reserve is a constant 3. | |
3549 | ||
3550 | Let I be the number of induction variables. | |
3551 | ||
3552 | -- if U + I + R <= A, the cost is I * SMALL_COST (just not to encourage | |
3553 | make a lot of ivs without a reason). | |
3554 | -- if A - R < U + I <= A, the cost is I * PRES_COST | |
3555 | -- if U + I > A, the cost is I * PRES_COST and | |
3556 | number of uses * SPILL_COST * (U + I - A) / (U + I) is added. */ | |
3557 | ||
3558 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3559 | { | |
3560 | fprintf (dump_file, "Global costs:\n"); | |
3561 | fprintf (dump_file, " target_avail_regs %d\n", target_avail_regs); | |
3562 | fprintf (dump_file, " target_small_cost %d\n", target_small_cost); | |
3563 | fprintf (dump_file, " target_pres_cost %d\n", target_pres_cost); | |
3564 | fprintf (dump_file, " target_spill_cost %d\n", target_spill_cost); | |
3565 | } | |
3566 | ||
3567 | n = 0; | |
bb29d951 | 3568 | for (phi = phi_nodes (loop->header); phi; phi = PHI_CHAIN (phi)) |
8b11a64c ZD |
3569 | { |
3570 | op = PHI_RESULT (phi); | |
3571 | ||
3572 | if (!is_gimple_reg (op)) | |
3573 | continue; | |
3574 | ||
3575 | if (get_iv (data, op)) | |
3576 | continue; | |
3577 | ||
3578 | n++; | |
3579 | } | |
3580 | ||
87c476a2 | 3581 | EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, j, bi) |
8b11a64c ZD |
3582 | { |
3583 | struct version_info *info = ver_info (data, j); | |
3584 | ||
3585 | if (info->inv_id && info->has_nonlin_use) | |
3586 | n++; | |
87c476a2 | 3587 | } |
8b11a64c ZD |
3588 | |
3589 | loop_data (loop)->regs_used = n; | |
3590 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3591 | fprintf (dump_file, " regs_used %d\n", n); | |
3592 | ||
3593 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3594 | { | |
3595 | fprintf (dump_file, " cost for size:\n"); | |
3596 | fprintf (dump_file, " ivs\tcost\n"); | |
3597 | for (j = 0; j <= 2 * target_avail_regs; j++) | |
3598 | fprintf (dump_file, " %d\t%d\n", j, | |
3599 | ivopts_global_cost_for_size (data, j)); | |
3600 | fprintf (dump_file, "\n"); | |
3601 | } | |
3602 | } | |
3603 | ||
b1b02be2 | 3604 | /* Returns true if A is a cheaper cost pair than B. */ |
8b11a64c | 3605 | |
b1b02be2 ZD |
3606 | static bool |
3607 | cheaper_cost_pair (struct cost_pair *a, struct cost_pair *b) | |
8b11a64c | 3608 | { |
b1b02be2 ZD |
3609 | if (!a) |
3610 | return false; | |
8b11a64c | 3611 | |
b1b02be2 ZD |
3612 | if (!b) |
3613 | return true; | |
3614 | ||
3615 | if (a->cost < b->cost) | |
3616 | return true; | |
3617 | ||
3618 | if (a->cost > b->cost) | |
3619 | return false; | |
3620 | ||
3621 | /* In case the costs are the same, prefer the cheaper candidate. */ | |
3622 | if (a->cand->cost < b->cand->cost) | |
3623 | return true; | |
3624 | ||
3625 | return false; | |
3626 | } | |
3627 | ||
3628 | /* Computes the cost field of IVS structure. */ | |
3629 | ||
3630 | static void | |
3631 | iv_ca_recount_cost (struct ivopts_data *data, struct iv_ca *ivs) | |
3632 | { | |
3633 | unsigned cost = 0; | |
3634 | ||
3635 | cost += ivs->cand_use_cost; | |
3636 | cost += ivs->cand_cost; | |
3637 | cost += ivopts_global_cost_for_size (data, ivs->n_regs); | |
3638 | ||
3639 | ivs->cost = cost; | |
3640 | } | |
3641 | ||
3642 | /* Set USE not to be expressed by any candidate in IVS. */ | |
3643 | ||
3644 | static void | |
3645 | iv_ca_set_no_cp (struct ivopts_data *data, struct iv_ca *ivs, | |
3646 | struct iv_use *use) | |
3647 | { | |
3648 | unsigned uid = use->id, cid, iid; | |
3649 | bitmap deps; | |
3650 | struct cost_pair *cp; | |
3651 | bitmap_iterator bi; | |
3652 | ||
3653 | cp = ivs->cand_for_use[uid]; | |
3654 | if (!cp) | |
3655 | return; | |
3656 | cid = cp->cand->id; | |
3657 | ||
3658 | ivs->bad_uses++; | |
3659 | ivs->cand_for_use[uid] = NULL; | |
3660 | ivs->n_cand_uses[cid]--; | |
3661 | ||
3662 | if (ivs->n_cand_uses[cid] == 0) | |
8b11a64c | 3663 | { |
b1b02be2 ZD |
3664 | bitmap_clear_bit (ivs->cands, cid); |
3665 | /* Do not count the pseudocandidates. */ | |
3666 | if (cp->cand->iv) | |
3667 | ivs->n_regs--; | |
3668 | ivs->cand_cost -= cp->cand->cost; | |
3669 | } | |
3670 | ||
3671 | ivs->cand_use_cost -= cp->cost; | |
3672 | ||
3673 | deps = cp->depends_on; | |
80cad5fa | 3674 | |
b1b02be2 ZD |
3675 | if (deps) |
3676 | { | |
3677 | EXECUTE_IF_SET_IN_BITMAP (deps, 0, iid, bi) | |
3678 | { | |
3679 | ivs->n_invariant_uses[iid]--; | |
3680 | if (ivs->n_invariant_uses[iid] == 0) | |
3681 | ivs->n_regs--; | |
3682 | } | |
8b11a64c ZD |
3683 | } |
3684 | ||
b1b02be2 ZD |
3685 | iv_ca_recount_cost (data, ivs); |
3686 | } | |
3687 | ||
3688 | /* Set cost pair for USE in set IVS to CP. */ | |
3689 | ||
3690 | static void | |
3691 | iv_ca_set_cp (struct ivopts_data *data, struct iv_ca *ivs, | |
3692 | struct iv_use *use, struct cost_pair *cp) | |
3693 | { | |
3694 | unsigned uid = use->id, cid, iid; | |
3695 | bitmap deps; | |
3696 | bitmap_iterator bi; | |
3697 | ||
3698 | if (ivs->cand_for_use[uid] == cp) | |
3699 | return; | |
3700 | ||
3701 | if (ivs->cand_for_use[uid]) | |
3702 | iv_ca_set_no_cp (data, ivs, use); | |
3703 | ||
3704 | if (cp) | |
8b11a64c | 3705 | { |
b1b02be2 | 3706 | cid = cp->cand->id; |
8b11a64c | 3707 | |
b1b02be2 ZD |
3708 | ivs->bad_uses--; |
3709 | ivs->cand_for_use[uid] = cp; | |
3710 | ivs->n_cand_uses[cid]++; | |
3711 | if (ivs->n_cand_uses[cid] == 1) | |
8b11a64c | 3712 | { |
b1b02be2 ZD |
3713 | bitmap_set_bit (ivs->cands, cid); |
3714 | /* Do not count the pseudocandidates. */ | |
3715 | if (cp->cand->iv) | |
3716 | ivs->n_regs++; | |
3717 | ivs->cand_cost += cp->cand->cost; | |
8b11a64c ZD |
3718 | } |
3719 | ||
b1b02be2 ZD |
3720 | ivs->cand_use_cost += cp->cost; |
3721 | ||
3722 | deps = cp->depends_on; | |
3723 | ||
3724 | if (deps) | |
8b11a64c | 3725 | { |
b1b02be2 | 3726 | EXECUTE_IF_SET_IN_BITMAP (deps, 0, iid, bi) |
87c476a2 | 3727 | { |
b1b02be2 ZD |
3728 | ivs->n_invariant_uses[iid]++; |
3729 | if (ivs->n_invariant_uses[iid] == 1) | |
3730 | ivs->n_regs++; | |
87c476a2 | 3731 | } |
8b11a64c ZD |
3732 | } |
3733 | ||
b1b02be2 | 3734 | iv_ca_recount_cost (data, ivs); |
87c476a2 | 3735 | } |
b1b02be2 ZD |
3736 | } |
3737 | ||
3738 | /* Extend set IVS by expressing USE by some of the candidates in it | |
3739 | if possible. */ | |
3740 | ||
3741 | static void | |
3742 | iv_ca_add_use (struct ivopts_data *data, struct iv_ca *ivs, | |
3743 | struct iv_use *use) | |
3744 | { | |
3745 | struct cost_pair *best_cp = NULL, *cp; | |
3746 | bitmap_iterator bi; | |
3747 | unsigned i; | |
8b11a64c | 3748 | |
b1b02be2 ZD |
3749 | gcc_assert (ivs->upto >= use->id); |
3750 | ||
3751 | if (ivs->upto == use->id) | |
3752 | { | |
3753 | ivs->upto++; | |
3754 | ivs->bad_uses++; | |
3755 | } | |
8b11a64c | 3756 | |
b1b02be2 ZD |
3757 | EXECUTE_IF_SET_IN_BITMAP (ivs->cands, 0, i, bi) |
3758 | { | |
3759 | cp = get_use_iv_cost (data, use, iv_cand (data, i)); | |
8b11a64c | 3760 | |
b1b02be2 ZD |
3761 | if (cheaper_cost_pair (cp, best_cp)) |
3762 | best_cp = cp; | |
3763 | } | |
8b11a64c | 3764 | |
b1b02be2 | 3765 | iv_ca_set_cp (data, ivs, use, best_cp); |
8b11a64c ZD |
3766 | } |
3767 | ||
b1b02be2 | 3768 | /* Get cost for assignment IVS. */ |
8b11a64c ZD |
3769 | |
3770 | static unsigned | |
b1b02be2 ZD |
3771 | iv_ca_cost (struct iv_ca *ivs) |
3772 | { | |
3773 | return (ivs->bad_uses ? INFTY : ivs->cost); | |
3774 | } | |
3775 | ||
3776 | /* Returns true if all dependences of CP are among invariants in IVS. */ | |
3777 | ||
3778 | static bool | |
3779 | iv_ca_has_deps (struct iv_ca *ivs, struct cost_pair *cp) | |
8b11a64c ZD |
3780 | { |
3781 | unsigned i; | |
87c476a2 | 3782 | bitmap_iterator bi; |
8b11a64c | 3783 | |
b1b02be2 ZD |
3784 | if (!cp->depends_on) |
3785 | return true; | |
3786 | ||
3787 | EXECUTE_IF_SET_IN_BITMAP (cp->depends_on, 0, i, bi) | |
8b11a64c | 3788 | { |
b1b02be2 ZD |
3789 | if (ivs->n_invariant_uses[i] == 0) |
3790 | return false; | |
3791 | } | |
3792 | ||
3793 | return true; | |
3794 | } | |
3795 | ||
3796 | /* Creates change of expressing USE by NEW_CP instead of OLD_CP and chains | |
3797 | it before NEXT_CHANGE. */ | |
3798 | ||
3799 | static struct iv_ca_delta * | |
3800 | iv_ca_delta_add (struct iv_use *use, struct cost_pair *old_cp, | |
3801 | struct cost_pair *new_cp, struct iv_ca_delta *next_change) | |
3802 | { | |
3803 | struct iv_ca_delta *change = xmalloc (sizeof (struct iv_ca_delta)); | |
3804 | ||
3805 | change->use = use; | |
3806 | change->old_cp = old_cp; | |
3807 | change->new_cp = new_cp; | |
3808 | change->next_change = next_change; | |
3809 | ||
3810 | return change; | |
3811 | } | |
3812 | ||
3813 | /* Returns candidate by that USE is expressed in IVS. */ | |
3814 | ||
3815 | static struct cost_pair * | |
3816 | iv_ca_cand_for_use (struct iv_ca *ivs, struct iv_use *use) | |
3817 | { | |
3818 | return ivs->cand_for_use[use->id]; | |
3819 | } | |
3820 | ||
3821 | /* Commit changes in DELTA to IVS. If FORWARD is false, the changes are | |
3822 | reverted instead. */ | |
3823 | ||
3824 | static void | |
3825 | iv_ca_delta_commit (struct ivopts_data *data, struct iv_ca *ivs, | |
3826 | struct iv_ca_delta *delta, bool forward) | |
3827 | { | |
3828 | struct cost_pair *from, *to; | |
3829 | ||
3830 | for (; delta; delta = delta->next_change) | |
3831 | { | |
3832 | if (forward) | |
8b11a64c | 3833 | { |
b1b02be2 ZD |
3834 | from = delta->old_cp; |
3835 | to = delta->new_cp; | |
3836 | } | |
3837 | else | |
3838 | { | |
3839 | from = delta->new_cp; | |
3840 | to = delta->old_cp; | |
8b11a64c | 3841 | } |
b1b02be2 ZD |
3842 | |
3843 | gcc_assert (iv_ca_cand_for_use (ivs, delta->use) == from); | |
3844 | iv_ca_set_cp (data, ivs, delta->use, to); | |
8b11a64c | 3845 | } |
b1b02be2 | 3846 | } |
8b11a64c | 3847 | |
b1b02be2 | 3848 | /* Returns true if CAND is used in IVS. */ |
8b11a64c | 3849 | |
b1b02be2 ZD |
3850 | static bool |
3851 | iv_ca_cand_used_p (struct iv_ca *ivs, struct iv_cand *cand) | |
3852 | { | |
3853 | return ivs->n_cand_uses[cand->id] > 0; | |
3854 | } | |
8b11a64c | 3855 | |
b1b02be2 ZD |
3856 | /* Free the list of changes DELTA. */ |
3857 | ||
3858 | static void | |
3859 | iv_ca_delta_free (struct iv_ca_delta **delta) | |
3860 | { | |
3861 | struct iv_ca_delta *act, *next; | |
3862 | ||
3863 | for (act = *delta; act; act = next) | |
87c476a2 | 3864 | { |
b1b02be2 ZD |
3865 | next = act->next_change; |
3866 | free (act); | |
87c476a2 | 3867 | } |
8b11a64c | 3868 | |
b1b02be2 ZD |
3869 | *delta = NULL; |
3870 | } | |
3871 | ||
3872 | /* Allocates new iv candidates assignment. */ | |
3873 | ||
3874 | static struct iv_ca * | |
3875 | iv_ca_new (struct ivopts_data *data) | |
3876 | { | |
3877 | struct iv_ca *nw = xmalloc (sizeof (struct iv_ca)); | |
8b11a64c | 3878 | |
b1b02be2 ZD |
3879 | nw->upto = 0; |
3880 | nw->bad_uses = 0; | |
3881 | nw->cand_for_use = xcalloc (n_iv_uses (data), sizeof (struct cost_pair *)); | |
3882 | nw->n_cand_uses = xcalloc (n_iv_cands (data), sizeof (unsigned)); | |
3883 | nw->cands = BITMAP_XMALLOC (); | |
3884 | nw->n_regs = 0; | |
3885 | nw->cand_use_cost = 0; | |
3886 | nw->cand_cost = 0; | |
3887 | nw->n_invariant_uses = xcalloc (data->max_inv_id + 1, sizeof (unsigned)); | |
3888 | nw->cost = 0; | |
3889 | ||
3890 | return nw; | |
3891 | } | |
3892 | ||
3893 | /* Free memory occupied by the set IVS. */ | |
3894 | ||
3895 | static void | |
3896 | iv_ca_free (struct iv_ca **ivs) | |
3897 | { | |
3898 | free ((*ivs)->cand_for_use); | |
3899 | free ((*ivs)->n_cand_uses); | |
3900 | BITMAP_XFREE ((*ivs)->cands); | |
3901 | free ((*ivs)->n_invariant_uses); | |
3902 | free (*ivs); | |
3903 | *ivs = NULL; | |
3904 | } | |
3905 | ||
3906 | /* Dumps IVS to FILE. */ | |
3907 | ||
3908 | static void | |
3909 | iv_ca_dump (struct ivopts_data *data, FILE *file, struct iv_ca *ivs) | |
3910 | { | |
3911 | const char *pref = " invariants "; | |
3912 | unsigned i; | |
3913 | ||
3914 | fprintf (file, " cost %d\n", iv_ca_cost (ivs)); | |
3915 | bitmap_print (file, ivs->cands, " candidates ","\n"); | |
3916 | ||
3917 | for (i = 1; i <= data->max_inv_id; i++) | |
3918 | if (ivs->n_invariant_uses[i]) | |
3919 | { | |
3920 | fprintf (file, "%s%d", pref, i); | |
3921 | pref = ", "; | |
3922 | } | |
3923 | fprintf (file, "\n"); | |
3924 | } | |
3925 | ||
3926 | /* Try changing candidate in IVS to CAND for each use. Return cost of the | |
3927 | new set, and store differences in DELTA. */ | |
3928 | ||
3929 | static unsigned | |
3930 | iv_ca_extend (struct ivopts_data *data, struct iv_ca *ivs, | |
3931 | struct iv_cand *cand, struct iv_ca_delta **delta) | |
3932 | { | |
3933 | unsigned i, cost; | |
3934 | struct iv_use *use; | |
3935 | struct cost_pair *old_cp, *new_cp; | |
3936 | ||
3937 | *delta = NULL; | |
3938 | for (i = 0; i < ivs->upto; i++) | |
3939 | { | |
3940 | use = iv_use (data, i); | |
3941 | old_cp = iv_ca_cand_for_use (ivs, use); | |
3942 | ||
3943 | if (old_cp | |
3944 | && old_cp->cand == cand) | |
3945 | continue; | |
3946 | ||
3947 | new_cp = get_use_iv_cost (data, use, cand); | |
3948 | if (!new_cp) | |
3949 | continue; | |
3950 | ||
3951 | if (!iv_ca_has_deps (ivs, new_cp)) | |
3952 | continue; | |
3953 | ||
3954 | if (!cheaper_cost_pair (new_cp, old_cp)) | |
3955 | continue; | |
3956 | ||
3957 | *delta = iv_ca_delta_add (use, old_cp, new_cp, *delta); | |
3958 | } | |
3959 | ||
3960 | iv_ca_delta_commit (data, ivs, *delta, true); | |
3961 | cost = iv_ca_cost (ivs); | |
3962 | iv_ca_delta_commit (data, ivs, *delta, false); | |
8b11a64c ZD |
3963 | |
3964 | return cost; | |
3965 | } | |
3966 | ||
a0eca485 | 3967 | /* Try narrowing set IVS by removing CAND. Return the cost of |
b1b02be2 | 3968 | the new set and store the differences in DELTA. */ |
8b11a64c ZD |
3969 | |
3970 | static unsigned | |
b1b02be2 ZD |
3971 | iv_ca_narrow (struct ivopts_data *data, struct iv_ca *ivs, |
3972 | struct iv_cand *cand, struct iv_ca_delta **delta) | |
8b11a64c | 3973 | { |
b1b02be2 ZD |
3974 | unsigned i, ci; |
3975 | struct iv_use *use; | |
3976 | struct cost_pair *old_cp, *new_cp, *cp; | |
3977 | bitmap_iterator bi; | |
3978 | struct iv_cand *cnd; | |
3979 | unsigned cost; | |
3980 | ||
3981 | *delta = NULL; | |
3982 | for (i = 0; i < n_iv_uses (data); i++) | |
3983 | { | |
3984 | use = iv_use (data, i); | |
3985 | ||
3986 | old_cp = iv_ca_cand_for_use (ivs, use); | |
3987 | if (old_cp->cand != cand) | |
3988 | continue; | |
3989 | ||
3990 | new_cp = NULL; | |
3991 | ||
3992 | if (data->consider_all_candidates) | |
3993 | { | |
3994 | EXECUTE_IF_SET_IN_BITMAP (ivs->cands, 0, ci, bi) | |
3995 | { | |
3996 | if (ci == cand->id) | |
3997 | continue; | |
3998 | ||
3999 | cnd = iv_cand (data, ci); | |
4000 | ||
4001 | cp = get_use_iv_cost (data, use, cnd); | |
4002 | if (!cp) | |
4003 | continue; | |
4004 | if (!iv_ca_has_deps (ivs, cp)) | |
4005 | continue; | |
4006 | ||
4007 | if (!cheaper_cost_pair (cp, new_cp)) | |
4008 | continue; | |
4009 | ||
4010 | new_cp = cp; | |
4011 | } | |
4012 | } | |
4013 | else | |
4014 | { | |
4015 | EXECUTE_IF_AND_IN_BITMAP (use->related_cands, ivs->cands, 0, ci, bi) | |
4016 | { | |
4017 | if (ci == cand->id) | |
4018 | continue; | |
4019 | ||
4020 | cnd = iv_cand (data, ci); | |
4021 | ||
4022 | cp = get_use_iv_cost (data, use, cnd); | |
4023 | if (!cp) | |
4024 | continue; | |
4025 | if (!iv_ca_has_deps (ivs, cp)) | |
4026 | continue; | |
4027 | ||
4028 | if (!cheaper_cost_pair (cp, new_cp)) | |
4029 | continue; | |
4030 | ||
4031 | new_cp = cp; | |
4032 | } | |
4033 | } | |
4034 | ||
4035 | if (!new_cp) | |
4036 | { | |
4037 | iv_ca_delta_free (delta); | |
4038 | return INFTY; | |
4039 | } | |
4040 | ||
4041 | *delta = iv_ca_delta_add (use, old_cp, new_cp, *delta); | |
4042 | } | |
4043 | ||
4044 | iv_ca_delta_commit (data, ivs, *delta, true); | |
4045 | cost = iv_ca_cost (ivs); | |
4046 | iv_ca_delta_commit (data, ivs, *delta, false); | |
4047 | ||
4048 | return cost; | |
8b11a64c ZD |
4049 | } |
4050 | ||
b1b02be2 | 4051 | /* Tries to extend the sets IVS in the best possible way in order |
8b11a64c ZD |
4052 | to express the USE. */ |
4053 | ||
4054 | static bool | |
b1b02be2 | 4055 | try_add_cand_for (struct ivopts_data *data, struct iv_ca *ivs, |
8b11a64c ZD |
4056 | struct iv_use *use) |
4057 | { | |
b1b02be2 | 4058 | unsigned best_cost, act_cost; |
8b11a64c | 4059 | unsigned i; |
38b0dcb8 ZD |
4060 | bitmap_iterator bi; |
4061 | struct iv_cand *cand; | |
b1b02be2 ZD |
4062 | struct iv_ca_delta *best_delta = NULL, *act_delta; |
4063 | struct cost_pair *cp; | |
4064 | ||
4065 | iv_ca_add_use (data, ivs, use); | |
4066 | best_cost = iv_ca_cost (ivs); | |
8b11a64c | 4067 | |
b1b02be2 ZD |
4068 | cp = iv_ca_cand_for_use (ivs, use); |
4069 | if (cp) | |
4070 | { | |
4071 | best_delta = iv_ca_delta_add (use, NULL, cp, NULL); | |
4072 | iv_ca_set_no_cp (data, ivs, use); | |
4073 | } | |
8b11a64c | 4074 | |
38b0dcb8 ZD |
4075 | /* First try important candidates. Only if it fails, try the specific ones. |
4076 | Rationale -- in loops with many variables the best choice often is to use | |
4077 | just one generic biv. If we added here many ivs specific to the uses, | |
4078 | the optimization algorithm later would be likely to get stuck in a local | |
4079 | minimum, thus causing us to create too many ivs. The approach from | |
1c170b5e | 4080 | few ivs to more seems more likely to be successful -- starting from few |
38b0dcb8 ZD |
4081 | ivs, replacing an expensive use by a specific iv should always be a |
4082 | win. */ | |
4083 | EXECUTE_IF_SET_IN_BITMAP (data->important_candidates, 0, i, bi) | |
8b11a64c | 4084 | { |
38b0dcb8 ZD |
4085 | cand = iv_cand (data, i); |
4086 | ||
b1b02be2 | 4087 | if (iv_ca_cand_used_p (ivs, cand)) |
8b11a64c ZD |
4088 | continue; |
4089 | ||
b1b02be2 ZD |
4090 | cp = get_use_iv_cost (data, use, cand); |
4091 | if (!cp) | |
4092 | continue; | |
4093 | ||
4094 | iv_ca_set_cp (data, ivs, use, cp); | |
4095 | act_cost = iv_ca_extend (data, ivs, cand, &act_delta); | |
4096 | iv_ca_set_no_cp (data, ivs, use); | |
4097 | act_delta = iv_ca_delta_add (use, NULL, cp, act_delta); | |
8b11a64c ZD |
4098 | |
4099 | if (act_cost < best_cost) | |
4100 | { | |
4101 | best_cost = act_cost; | |
b1b02be2 ZD |
4102 | |
4103 | iv_ca_delta_free (&best_delta); | |
4104 | best_delta = act_delta; | |
8b11a64c | 4105 | } |
b1b02be2 ZD |
4106 | else |
4107 | iv_ca_delta_free (&act_delta); | |
8b11a64c ZD |
4108 | } |
4109 | ||
38b0dcb8 ZD |
4110 | if (best_cost == INFTY) |
4111 | { | |
4112 | for (i = 0; i < use->n_map_members; i++) | |
4113 | { | |
4114 | cp = use->cost_map + i; | |
b1b02be2 ZD |
4115 | cand = cp->cand; |
4116 | if (!cand) | |
38b0dcb8 ZD |
4117 | continue; |
4118 | ||
4119 | /* Already tried this. */ | |
b1b02be2 ZD |
4120 | if (cand->important) |
4121 | continue; | |
4122 | ||
4123 | if (iv_ca_cand_used_p (ivs, cand)) | |
38b0dcb8 ZD |
4124 | continue; |
4125 | ||
b1b02be2 ZD |
4126 | act_delta = NULL; |
4127 | iv_ca_set_cp (data, ivs, use, cp); | |
4128 | act_cost = iv_ca_extend (data, ivs, cand, &act_delta); | |
4129 | iv_ca_set_no_cp (data, ivs, use); | |
4130 | act_delta = iv_ca_delta_add (use, iv_ca_cand_for_use (ivs, use), | |
4131 | cp, act_delta); | |
38b0dcb8 ZD |
4132 | |
4133 | if (act_cost < best_cost) | |
4134 | { | |
4135 | best_cost = act_cost; | |
b1b02be2 ZD |
4136 | |
4137 | if (best_delta) | |
4138 | iv_ca_delta_free (&best_delta); | |
4139 | best_delta = act_delta; | |
38b0dcb8 | 4140 | } |
b1b02be2 ZD |
4141 | else |
4142 | iv_ca_delta_free (&act_delta); | |
38b0dcb8 ZD |
4143 | } |
4144 | } | |
4145 | ||
b1b02be2 ZD |
4146 | iv_ca_delta_commit (data, ivs, best_delta, true); |
4147 | iv_ca_delta_free (&best_delta); | |
8b11a64c ZD |
4148 | |
4149 | return (best_cost != INFTY); | |
4150 | } | |
4151 | ||
b1b02be2 | 4152 | /* Finds an initial assignment of candidates to uses. */ |
8b11a64c | 4153 | |
b1b02be2 ZD |
4154 | static struct iv_ca * |
4155 | get_initial_solution (struct ivopts_data *data) | |
8b11a64c | 4156 | { |
b1b02be2 | 4157 | struct iv_ca *ivs = iv_ca_new (data); |
8b11a64c ZD |
4158 | unsigned i; |
4159 | ||
4160 | for (i = 0; i < n_iv_uses (data); i++) | |
b1b02be2 ZD |
4161 | if (!try_add_cand_for (data, ivs, iv_use (data, i))) |
4162 | { | |
4163 | iv_ca_free (&ivs); | |
4164 | return NULL; | |
4165 | } | |
8b11a64c | 4166 | |
b1b02be2 | 4167 | return ivs; |
8b11a64c ZD |
4168 | } |
4169 | ||
b1b02be2 | 4170 | /* Tries to improve set of induction variables IVS. */ |
8b11a64c ZD |
4171 | |
4172 | static bool | |
b1b02be2 | 4173 | try_improve_iv_set (struct ivopts_data *data, struct iv_ca *ivs) |
8b11a64c | 4174 | { |
b1b02be2 ZD |
4175 | unsigned i, acost, best_cost = iv_ca_cost (ivs); |
4176 | struct iv_ca_delta *best_delta = NULL, *act_delta; | |
4177 | struct iv_cand *cand; | |
8b11a64c ZD |
4178 | |
4179 | /* Try altering the set of induction variables by one. */ | |
4180 | for (i = 0; i < n_iv_cands (data); i++) | |
4181 | { | |
b1b02be2 ZD |
4182 | cand = iv_cand (data, i); |
4183 | ||
4184 | if (iv_ca_cand_used_p (ivs, cand)) | |
4185 | acost = iv_ca_narrow (data, ivs, cand, &act_delta); | |
8b11a64c | 4186 | else |
b1b02be2 | 4187 | acost = iv_ca_extend (data, ivs, cand, &act_delta); |
8b11a64c | 4188 | |
b1b02be2 | 4189 | if (acost < best_cost) |
8b11a64c | 4190 | { |
b1b02be2 ZD |
4191 | best_cost = acost; |
4192 | if (best_delta) | |
4193 | iv_ca_delta_free (&best_delta); | |
4194 | best_delta = act_delta; | |
8b11a64c | 4195 | } |
8b11a64c | 4196 | else |
b1b02be2 | 4197 | iv_ca_delta_free (&act_delta); |
8b11a64c ZD |
4198 | } |
4199 | ||
b1b02be2 | 4200 | if (!best_delta) |
8b11a64c ZD |
4201 | return false; |
4202 | ||
b1b02be2 ZD |
4203 | iv_ca_delta_commit (data, ivs, best_delta, true); |
4204 | iv_ca_delta_free (&best_delta); | |
8b11a64c ZD |
4205 | return true; |
4206 | } | |
4207 | ||
4208 | /* Attempts to find the optimal set of induction variables. We do simple | |
4209 | greedy heuristic -- we try to replace at most one candidate in the selected | |
4210 | solution and remove the unused ivs while this improves the cost. */ | |
4211 | ||
b1b02be2 | 4212 | static struct iv_ca * |
8b11a64c ZD |
4213 | find_optimal_iv_set (struct ivopts_data *data) |
4214 | { | |
b1b02be2 ZD |
4215 | unsigned i; |
4216 | struct iv_ca *set; | |
8b11a64c ZD |
4217 | struct iv_use *use; |
4218 | ||
b1b02be2 ZD |
4219 | /* Get the initial solution. */ |
4220 | set = get_initial_solution (data); | |
4221 | if (!set) | |
8b11a64c ZD |
4222 | { |
4223 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4224 | fprintf (dump_file, "Unable to substitute for ivs, failed.\n"); | |
8b11a64c ZD |
4225 | return NULL; |
4226 | } | |
4227 | ||
4228 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4229 | { | |
b1b02be2 ZD |
4230 | fprintf (dump_file, "Initial set of candidates:\n"); |
4231 | iv_ca_dump (data, dump_file, set); | |
8b11a64c ZD |
4232 | } |
4233 | ||
b1b02be2 | 4234 | while (try_improve_iv_set (data, set)) |
8b11a64c ZD |
4235 | { |
4236 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4237 | { | |
b1b02be2 ZD |
4238 | fprintf (dump_file, "Improved to:\n"); |
4239 | iv_ca_dump (data, dump_file, set); | |
8b11a64c ZD |
4240 | } |
4241 | } | |
4242 | ||
4243 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
b1b02be2 | 4244 | fprintf (dump_file, "Final cost %d\n\n", iv_ca_cost (set)); |
8b11a64c ZD |
4245 | |
4246 | for (i = 0; i < n_iv_uses (data); i++) | |
4247 | { | |
4248 | use = iv_use (data, i); | |
b1b02be2 | 4249 | use->selected = iv_ca_cand_for_use (set, use)->cand; |
8b11a64c ZD |
4250 | } |
4251 | ||
8b11a64c ZD |
4252 | return set; |
4253 | } | |
4254 | ||
4255 | /* Creates a new induction variable corresponding to CAND. */ | |
4256 | ||
4257 | static void | |
4258 | create_new_iv (struct ivopts_data *data, struct iv_cand *cand) | |
4259 | { | |
4260 | block_stmt_iterator incr_pos; | |
4261 | tree base; | |
4262 | bool after = false; | |
4263 | ||
4264 | if (!cand->iv) | |
4265 | return; | |
4266 | ||
4267 | switch (cand->pos) | |
4268 | { | |
4269 | case IP_NORMAL: | |
4270 | incr_pos = bsi_last (ip_normal_pos (data->current_loop)); | |
4271 | break; | |
4272 | ||
4273 | case IP_END: | |
4274 | incr_pos = bsi_last (ip_end_pos (data->current_loop)); | |
4275 | after = true; | |
4276 | break; | |
4277 | ||
4278 | case IP_ORIGINAL: | |
4279 | /* Mark that the iv is preserved. */ | |
4280 | name_info (data, cand->var_before)->preserve_biv = true; | |
4281 | name_info (data, cand->var_after)->preserve_biv = true; | |
4282 | ||
4283 | /* Rewrite the increment so that it uses var_before directly. */ | |
4284 | find_interesting_uses_op (data, cand->var_after)->selected = cand; | |
4285 | ||
4286 | return; | |
4287 | } | |
4288 | ||
4289 | gimple_add_tmp_var (cand->var_before); | |
4290 | add_referenced_tmp_var (cand->var_before); | |
4291 | ||
4292 | base = unshare_expr (cand->iv->base); | |
4293 | ||
4294 | create_iv (base, cand->iv->step, cand->var_before, data->current_loop, | |
4295 | &incr_pos, after, &cand->var_before, &cand->var_after); | |
4296 | } | |
4297 | ||
4298 | /* Creates new induction variables described in SET. */ | |
4299 | ||
4300 | static void | |
b1b02be2 | 4301 | create_new_ivs (struct ivopts_data *data, struct iv_ca *set) |
8b11a64c ZD |
4302 | { |
4303 | unsigned i; | |
4304 | struct iv_cand *cand; | |
87c476a2 | 4305 | bitmap_iterator bi; |
8b11a64c | 4306 | |
b1b02be2 | 4307 | EXECUTE_IF_SET_IN_BITMAP (set->cands, 0, i, bi) |
8b11a64c ZD |
4308 | { |
4309 | cand = iv_cand (data, i); | |
4310 | create_new_iv (data, cand); | |
87c476a2 | 4311 | } |
8b11a64c ZD |
4312 | } |
4313 | ||
4314 | /* Removes statement STMT (real or a phi node). If INCLUDING_DEFINED_NAME | |
4315 | is true, remove also the ssa name defined by the statement. */ | |
4316 | ||
4317 | static void | |
4318 | remove_statement (tree stmt, bool including_defined_name) | |
4319 | { | |
4320 | if (TREE_CODE (stmt) == PHI_NODE) | |
4321 | { | |
4322 | if (!including_defined_name) | |
4323 | { | |
4324 | /* Prevent the ssa name defined by the statement from being removed. */ | |
4325 | SET_PHI_RESULT (stmt, NULL); | |
4326 | } | |
4327 | remove_phi_node (stmt, NULL_TREE, bb_for_stmt (stmt)); | |
4328 | } | |
4329 | else | |
4330 | { | |
1a1804c2 | 4331 | block_stmt_iterator bsi = bsi_for_stmt (stmt); |
8b11a64c ZD |
4332 | |
4333 | bsi_remove (&bsi); | |
4334 | } | |
4335 | } | |
4336 | ||
4337 | /* Rewrites USE (definition of iv used in a nonlinear expression) | |
4338 | using candidate CAND. */ | |
4339 | ||
4340 | static void | |
4341 | rewrite_use_nonlinear_expr (struct ivopts_data *data, | |
4342 | struct iv_use *use, struct iv_cand *cand) | |
4343 | { | |
4344 | tree comp = unshare_expr (get_computation (data->current_loop, | |
4345 | use, cand)); | |
4346 | tree op, stmts, tgt, ass; | |
4347 | block_stmt_iterator bsi, pbsi; | |
4348 | ||
1e128c5f | 4349 | switch (TREE_CODE (use->stmt)) |
8b11a64c | 4350 | { |
1e128c5f | 4351 | case PHI_NODE: |
8b11a64c ZD |
4352 | tgt = PHI_RESULT (use->stmt); |
4353 | ||
4354 | /* If we should keep the biv, do not replace it. */ | |
4355 | if (name_info (data, tgt)->preserve_biv) | |
4356 | return; | |
4357 | ||
4358 | pbsi = bsi = bsi_start (bb_for_stmt (use->stmt)); | |
4359 | while (!bsi_end_p (pbsi) | |
4360 | && TREE_CODE (bsi_stmt (pbsi)) == LABEL_EXPR) | |
4361 | { | |
4362 | bsi = pbsi; | |
4363 | bsi_next (&pbsi); | |
4364 | } | |
1e128c5f GB |
4365 | break; |
4366 | ||
4367 | case MODIFY_EXPR: | |
8b11a64c | 4368 | tgt = TREE_OPERAND (use->stmt, 0); |
1a1804c2 | 4369 | bsi = bsi_for_stmt (use->stmt); |
1e128c5f GB |
4370 | break; |
4371 | ||
4372 | default: | |
4373 | gcc_unreachable (); | |
8b11a64c | 4374 | } |
8b11a64c ZD |
4375 | |
4376 | op = force_gimple_operand (comp, &stmts, false, SSA_NAME_VAR (tgt)); | |
4377 | ||
4378 | if (TREE_CODE (use->stmt) == PHI_NODE) | |
4379 | { | |
4380 | if (stmts) | |
4381 | bsi_insert_after (&bsi, stmts, BSI_CONTINUE_LINKING); | |
4382 | ass = build2 (MODIFY_EXPR, TREE_TYPE (tgt), tgt, op); | |
4383 | bsi_insert_after (&bsi, ass, BSI_NEW_STMT); | |
4384 | remove_statement (use->stmt, false); | |
4385 | SSA_NAME_DEF_STMT (tgt) = ass; | |
4386 | } | |
4387 | else | |
4388 | { | |
4389 | if (stmts) | |
4390 | bsi_insert_before (&bsi, stmts, BSI_SAME_STMT); | |
4391 | TREE_OPERAND (use->stmt, 1) = op; | |
4392 | } | |
4393 | } | |
4394 | ||
4395 | /* Replaces ssa name in index IDX by its basic variable. Callback for | |
4396 | for_each_index. */ | |
4397 | ||
4398 | static bool | |
be35cf60 | 4399 | idx_remove_ssa_names (tree base, tree *idx, |
8b11a64c ZD |
4400 | void *data ATTRIBUTE_UNUSED) |
4401 | { | |
be35cf60 ZD |
4402 | tree *op; |
4403 | ||
8b11a64c ZD |
4404 | if (TREE_CODE (*idx) == SSA_NAME) |
4405 | *idx = SSA_NAME_VAR (*idx); | |
be35cf60 ZD |
4406 | |
4407 | if (TREE_CODE (base) == ARRAY_REF) | |
4408 | { | |
4409 | op = &TREE_OPERAND (base, 2); | |
4410 | if (*op | |
4411 | && TREE_CODE (*op) == SSA_NAME) | |
4412 | *op = SSA_NAME_VAR (*op); | |
4413 | op = &TREE_OPERAND (base, 3); | |
4414 | if (*op | |
4415 | && TREE_CODE (*op) == SSA_NAME) | |
4416 | *op = SSA_NAME_VAR (*op); | |
4417 | } | |
4418 | ||
8b11a64c ZD |
4419 | return true; |
4420 | } | |
4421 | ||
4422 | /* Unshares REF and replaces ssa names inside it by their basic variables. */ | |
4423 | ||
4424 | static tree | |
4425 | unshare_and_remove_ssa_names (tree ref) | |
4426 | { | |
4427 | ref = unshare_expr (ref); | |
4428 | for_each_index (&ref, idx_remove_ssa_names, NULL); | |
4429 | ||
4430 | return ref; | |
4431 | } | |
4432 | ||
4433 | /* Rewrites base of memory access OP with expression WITH in statement | |
4434 | pointed to by BSI. */ | |
4435 | ||
4436 | static void | |
4437 | rewrite_address_base (block_stmt_iterator *bsi, tree *op, tree with) | |
4438 | { | |
7ccf35ed | 4439 | tree bvar, var, new_var, new_name, copy, name; |
8b11a64c ZD |
4440 | tree orig; |
4441 | ||
7ccf35ed DN |
4442 | var = bvar = get_base_address (*op); |
4443 | ||
8b11a64c ZD |
4444 | if (!var || TREE_CODE (with) != SSA_NAME) |
4445 | goto do_rewrite; | |
be35cf60 ZD |
4446 | |
4447 | gcc_assert (TREE_CODE (var) != ALIGN_INDIRECT_REF); | |
4448 | gcc_assert (TREE_CODE (var) != MISALIGNED_INDIRECT_REF); | |
4449 | if (TREE_CODE (var) == INDIRECT_REF) | |
8b11a64c ZD |
4450 | var = TREE_OPERAND (var, 0); |
4451 | if (TREE_CODE (var) == SSA_NAME) | |
4452 | { | |
4453 | name = var; | |
4454 | var = SSA_NAME_VAR (var); | |
4455 | } | |
4456 | else if (DECL_P (var)) | |
4457 | name = NULL_TREE; | |
4458 | else | |
4459 | goto do_rewrite; | |
4460 | ||
4461 | if (var_ann (var)->type_mem_tag) | |
4462 | var = var_ann (var)->type_mem_tag; | |
4463 | ||
4464 | /* We need to add a memory tag for the variable. But we do not want | |
4465 | to add it to the temporary used for the computations, since this leads | |
4466 | to problems in redundancy elimination when there are common parts | |
4467 | in two computations referring to the different arrays. So we copy | |
4468 | the variable to a new temporary. */ | |
4469 | copy = build2 (MODIFY_EXPR, void_type_node, NULL_TREE, with); | |
4470 | if (name) | |
4471 | new_name = duplicate_ssa_name (name, copy); | |
4472 | else | |
4473 | { | |
4474 | new_var = create_tmp_var (TREE_TYPE (with), "ruatmp"); | |
4475 | add_referenced_tmp_var (new_var); | |
4476 | var_ann (new_var)->type_mem_tag = var; | |
4477 | new_name = make_ssa_name (new_var, copy); | |
4478 | } | |
4479 | TREE_OPERAND (copy, 0) = new_name; | |
4480 | bsi_insert_before (bsi, copy, BSI_SAME_STMT); | |
4481 | with = new_name; | |
4482 | ||
4483 | do_rewrite: | |
4484 | ||
4485 | orig = NULL_TREE; | |
be35cf60 ZD |
4486 | gcc_assert (TREE_CODE (*op) != ALIGN_INDIRECT_REF); |
4487 | gcc_assert (TREE_CODE (*op) != MISALIGNED_INDIRECT_REF); | |
4488 | ||
4489 | if (TREE_CODE (*op) == INDIRECT_REF) | |
8b11a64c ZD |
4490 | orig = REF_ORIGINAL (*op); |
4491 | if (!orig) | |
4492 | orig = unshare_and_remove_ssa_names (*op); | |
4493 | ||
be35cf60 | 4494 | *op = build1 (INDIRECT_REF, TREE_TYPE (*op), with); |
7ccf35ed | 4495 | |
8b11a64c ZD |
4496 | /* Record the original reference, for purposes of alias analysis. */ |
4497 | REF_ORIGINAL (*op) = orig; | |
4498 | } | |
4499 | ||
4500 | /* Rewrites USE (address that is an iv) using candidate CAND. */ | |
4501 | ||
4502 | static void | |
4503 | rewrite_use_address (struct ivopts_data *data, | |
4504 | struct iv_use *use, struct iv_cand *cand) | |
4505 | { | |
4506 | tree comp = unshare_expr (get_computation (data->current_loop, | |
4507 | use, cand)); | |
1a1804c2 | 4508 | block_stmt_iterator bsi = bsi_for_stmt (use->stmt); |
8b11a64c ZD |
4509 | tree stmts; |
4510 | tree op = force_gimple_operand (comp, &stmts, true, NULL_TREE); | |
4511 | ||
4512 | if (stmts) | |
4513 | bsi_insert_before (&bsi, stmts, BSI_SAME_STMT); | |
4514 | ||
4515 | rewrite_address_base (&bsi, use->op_p, op); | |
4516 | } | |
4517 | ||
4518 | /* Rewrites USE (the condition such that one of the arguments is an iv) using | |
4519 | candidate CAND. */ | |
4520 | ||
4521 | static void | |
4522 | rewrite_use_compare (struct ivopts_data *data, | |
4523 | struct iv_use *use, struct iv_cand *cand) | |
4524 | { | |
4525 | tree comp; | |
4526 | tree *op_p, cond, op, stmts, bound; | |
1a1804c2 | 4527 | block_stmt_iterator bsi = bsi_for_stmt (use->stmt); |
8b11a64c ZD |
4528 | enum tree_code compare; |
4529 | ||
4530 | if (may_eliminate_iv (data->current_loop, | |
4531 | use, cand, &compare, &bound)) | |
4532 | { | |
4533 | op = force_gimple_operand (unshare_expr (bound), &stmts, | |
4534 | true, NULL_TREE); | |
4535 | ||
4536 | if (stmts) | |
4537 | bsi_insert_before (&bsi, stmts, BSI_SAME_STMT); | |
4538 | ||
4539 | *use->op_p = build2 (compare, boolean_type_node, | |
4540 | var_at_stmt (data->current_loop, | |
4541 | cand, use->stmt), op); | |
4542 | modify_stmt (use->stmt); | |
4543 | return; | |
4544 | } | |
4545 | ||
4546 | /* The induction variable elimination failed; just express the original | |
4547 | giv. */ | |
4548 | comp = unshare_expr (get_computation (data->current_loop, use, cand)); | |
4549 | ||
4550 | cond = *use->op_p; | |
4551 | op_p = &TREE_OPERAND (cond, 0); | |
4552 | if (TREE_CODE (*op_p) != SSA_NAME | |
4553 | || zero_p (get_iv (data, *op_p)->step)) | |
4554 | op_p = &TREE_OPERAND (cond, 1); | |
4555 | ||
4556 | op = force_gimple_operand (comp, &stmts, true, SSA_NAME_VAR (*op_p)); | |
4557 | if (stmts) | |
4558 | bsi_insert_before (&bsi, stmts, BSI_SAME_STMT); | |
4559 | ||
4560 | *op_p = op; | |
4561 | } | |
4562 | ||
4563 | /* Ensure that operand *OP_P may be used at the end of EXIT without | |
4564 | violating loop closed ssa form. */ | |
4565 | ||
4566 | static void | |
4567 | protect_loop_closed_ssa_form_use (edge exit, use_operand_p op_p) | |
4568 | { | |
4569 | basic_block def_bb; | |
4570 | struct loop *def_loop; | |
4571 | tree phi, use; | |
4572 | ||
4573 | use = USE_FROM_PTR (op_p); | |
4574 | if (TREE_CODE (use) != SSA_NAME) | |
4575 | return; | |
4576 | ||
4577 | def_bb = bb_for_stmt (SSA_NAME_DEF_STMT (use)); | |
4578 | if (!def_bb) | |
4579 | return; | |
4580 | ||
4581 | def_loop = def_bb->loop_father; | |
4582 | if (flow_bb_inside_loop_p (def_loop, exit->dest)) | |
4583 | return; | |
4584 | ||
4585 | /* Try finding a phi node that copies the value out of the loop. */ | |
bb29d951 | 4586 | for (phi = phi_nodes (exit->dest); phi; phi = PHI_CHAIN (phi)) |
8b11a64c ZD |
4587 | if (PHI_ARG_DEF_FROM_EDGE (phi, exit) == use) |
4588 | break; | |
4589 | ||
4590 | if (!phi) | |
4591 | { | |
4592 | /* Create such a phi node. */ | |
4593 | tree new_name = duplicate_ssa_name (use, NULL); | |
4594 | ||
4595 | phi = create_phi_node (new_name, exit->dest); | |
4596 | SSA_NAME_DEF_STMT (new_name) = phi; | |
4597 | add_phi_arg (&phi, use, exit); | |
4598 | } | |
4599 | ||
4600 | SET_USE (op_p, PHI_RESULT (phi)); | |
4601 | } | |
4602 | ||
4603 | /* Ensure that operands of STMT may be used at the end of EXIT without | |
4604 | violating loop closed ssa form. */ | |
4605 | ||
4606 | static void | |
4607 | protect_loop_closed_ssa_form (edge exit, tree stmt) | |
4608 | { | |
4609 | use_optype uses; | |
4610 | vuse_optype vuses; | |
4611 | v_may_def_optype v_may_defs; | |
4612 | unsigned i; | |
4613 | ||
4614 | get_stmt_operands (stmt); | |
4615 | ||
4616 | uses = STMT_USE_OPS (stmt); | |
4617 | for (i = 0; i < NUM_USES (uses); i++) | |
4618 | protect_loop_closed_ssa_form_use (exit, USE_OP_PTR (uses, i)); | |
4619 | ||
4620 | vuses = STMT_VUSE_OPS (stmt); | |
4621 | for (i = 0; i < NUM_VUSES (vuses); i++) | |
4622 | protect_loop_closed_ssa_form_use (exit, VUSE_OP_PTR (vuses, i)); | |
4623 | ||
4624 | v_may_defs = STMT_V_MAY_DEF_OPS (stmt); | |
4625 | for (i = 0; i < NUM_V_MAY_DEFS (v_may_defs); i++) | |
4626 | protect_loop_closed_ssa_form_use (exit, V_MAY_DEF_OP_PTR (v_may_defs, i)); | |
4627 | } | |
4628 | ||
4629 | /* STMTS compute a value of a phi argument OP on EXIT of a loop. Arrange things | |
4630 | so that they are emitted on the correct place, and so that the loop closed | |
4631 | ssa form is preserved. */ | |
4632 | ||
4633 | static void | |
4634 | compute_phi_arg_on_exit (edge exit, tree stmts, tree op) | |
4635 | { | |
4636 | tree_stmt_iterator tsi; | |
4637 | block_stmt_iterator bsi; | |
4638 | tree phi, stmt, def, next; | |
4639 | ||
628f6a4e | 4640 | if (EDGE_COUNT (exit->dest->preds) > 1) |
8b11a64c ZD |
4641 | split_loop_exit_edge (exit); |
4642 | ||
4643 | if (TREE_CODE (stmts) == STATEMENT_LIST) | |
4644 | { | |
4645 | for (tsi = tsi_start (stmts); !tsi_end_p (tsi); tsi_next (&tsi)) | |
4646 | protect_loop_closed_ssa_form (exit, tsi_stmt (tsi)); | |
4647 | } | |
4648 | else | |
4649 | protect_loop_closed_ssa_form (exit, stmts); | |
4650 | ||
4651 | /* Ensure there is label in exit->dest, so that we can | |
4652 | insert after it. */ | |
4653 | tree_block_label (exit->dest); | |
4654 | bsi = bsi_after_labels (exit->dest); | |
4655 | bsi_insert_after (&bsi, stmts, BSI_CONTINUE_LINKING); | |
4656 | ||
4657 | if (!op) | |
4658 | return; | |
4659 | ||
4660 | for (phi = phi_nodes (exit->dest); phi; phi = next) | |
4661 | { | |
4662 | next = TREE_CHAIN (phi); | |
4663 | ||
4664 | if (PHI_ARG_DEF_FROM_EDGE (phi, exit) == op) | |
4665 | { | |
4666 | def = PHI_RESULT (phi); | |
4667 | remove_statement (phi, false); | |
4668 | stmt = build2 (MODIFY_EXPR, TREE_TYPE (op), | |
4669 | def, op); | |
4670 | SSA_NAME_DEF_STMT (def) = stmt; | |
4671 | bsi_insert_after (&bsi, stmt, BSI_CONTINUE_LINKING); | |
4672 | } | |
4673 | } | |
4674 | } | |
4675 | ||
4676 | /* Rewrites the final value of USE (that is only needed outside of the loop) | |
4677 | using candidate CAND. */ | |
4678 | ||
4679 | static void | |
4680 | rewrite_use_outer (struct ivopts_data *data, | |
4681 | struct iv_use *use, struct iv_cand *cand) | |
4682 | { | |
4683 | edge exit; | |
4684 | tree value, op, stmts, tgt; | |
4685 | tree phi; | |
4686 | ||
1e128c5f GB |
4687 | switch (TREE_CODE (use->stmt)) |
4688 | { | |
4689 | case PHI_NODE: | |
4690 | tgt = PHI_RESULT (use->stmt); | |
4691 | break; | |
4692 | case MODIFY_EXPR: | |
4693 | tgt = TREE_OPERAND (use->stmt, 0); | |
4694 | break; | |
4695 | default: | |
4696 | gcc_unreachable (); | |
4697 | } | |
4698 | ||
8b11a64c ZD |
4699 | exit = single_dom_exit (data->current_loop); |
4700 | ||
4701 | if (exit) | |
4702 | { | |
4703 | if (!cand->iv) | |
4704 | { | |
1e128c5f GB |
4705 | bool ok = may_replace_final_value (data->current_loop, use, &value); |
4706 | gcc_assert (ok); | |
8b11a64c ZD |
4707 | } |
4708 | else | |
4709 | value = get_computation_at (data->current_loop, | |
4710 | use, cand, last_stmt (exit->src)); | |
4711 | ||
2f4675b4 | 4712 | value = unshare_expr (value); |
8b11a64c ZD |
4713 | op = force_gimple_operand (value, &stmts, true, SSA_NAME_VAR (tgt)); |
4714 | ||
4715 | /* If we will preserve the iv anyway and we would need to perform | |
4716 | some computation to replace the final value, do nothing. */ | |
4717 | if (stmts && name_info (data, tgt)->preserve_biv) | |
4718 | return; | |
4719 | ||
bb29d951 | 4720 | for (phi = phi_nodes (exit->dest); phi; phi = PHI_CHAIN (phi)) |
8b11a64c ZD |
4721 | { |
4722 | use_operand_p use_p = PHI_ARG_DEF_PTR_FROM_EDGE (phi, exit); | |
4723 | ||
4724 | if (USE_FROM_PTR (use_p) == tgt) | |
4725 | SET_USE (use_p, op); | |
4726 | } | |
4727 | ||
4728 | if (stmts) | |
4729 | compute_phi_arg_on_exit (exit, stmts, op); | |
4730 | ||
4731 | /* Enable removal of the statement. We cannot remove it directly, | |
4732 | since we may still need the aliasing information attached to the | |
4733 | ssa name defined by it. */ | |
4734 | name_info (data, tgt)->iv->have_use_for = false; | |
4735 | return; | |
4736 | } | |
4737 | ||
4738 | /* If the variable is going to be preserved anyway, there is nothing to | |
4739 | do. */ | |
4740 | if (name_info (data, tgt)->preserve_biv) | |
4741 | return; | |
4742 | ||
4743 | /* Otherwise we just need to compute the iv. */ | |
4744 | rewrite_use_nonlinear_expr (data, use, cand); | |
4745 | } | |
4746 | ||
4747 | /* Rewrites USE using candidate CAND. */ | |
4748 | ||
4749 | static void | |
4750 | rewrite_use (struct ivopts_data *data, | |
4751 | struct iv_use *use, struct iv_cand *cand) | |
4752 | { | |
4753 | switch (use->type) | |
4754 | { | |
4755 | case USE_NONLINEAR_EXPR: | |
4756 | rewrite_use_nonlinear_expr (data, use, cand); | |
4757 | break; | |
4758 | ||
4759 | case USE_OUTER: | |
4760 | rewrite_use_outer (data, use, cand); | |
4761 | break; | |
4762 | ||
4763 | case USE_ADDRESS: | |
4764 | rewrite_use_address (data, use, cand); | |
4765 | break; | |
4766 | ||
4767 | case USE_COMPARE: | |
4768 | rewrite_use_compare (data, use, cand); | |
4769 | break; | |
4770 | ||
4771 | default: | |
1e128c5f | 4772 | gcc_unreachable (); |
8b11a64c ZD |
4773 | } |
4774 | modify_stmt (use->stmt); | |
4775 | } | |
4776 | ||
4777 | /* Rewrite the uses using the selected induction variables. */ | |
4778 | ||
4779 | static void | |
4780 | rewrite_uses (struct ivopts_data *data) | |
4781 | { | |
4782 | unsigned i; | |
4783 | struct iv_cand *cand; | |
4784 | struct iv_use *use; | |
4785 | ||
4786 | for (i = 0; i < n_iv_uses (data); i++) | |
4787 | { | |
4788 | use = iv_use (data, i); | |
4789 | cand = use->selected; | |
1e128c5f | 4790 | gcc_assert (cand); |
8b11a64c ZD |
4791 | |
4792 | rewrite_use (data, use, cand); | |
4793 | } | |
4794 | } | |
4795 | ||
4796 | /* Removes the ivs that are not used after rewriting. */ | |
4797 | ||
4798 | static void | |
4799 | remove_unused_ivs (struct ivopts_data *data) | |
4800 | { | |
4801 | unsigned j; | |
87c476a2 | 4802 | bitmap_iterator bi; |
8b11a64c | 4803 | |
87c476a2 | 4804 | EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, j, bi) |
8b11a64c ZD |
4805 | { |
4806 | struct version_info *info; | |
4807 | ||
4808 | info = ver_info (data, j); | |
4809 | if (info->iv | |
4810 | && !zero_p (info->iv->step) | |
4811 | && !info->inv_id | |
4812 | && !info->iv->have_use_for | |
4813 | && !info->preserve_biv) | |
4814 | remove_statement (SSA_NAME_DEF_STMT (info->iv->ssa_name), true); | |
87c476a2 | 4815 | } |
8b11a64c ZD |
4816 | } |
4817 | ||
4818 | /* Frees data allocated by the optimization of a single loop. */ | |
4819 | ||
4820 | static void | |
4821 | free_loop_data (struct ivopts_data *data) | |
4822 | { | |
4823 | unsigned i, j; | |
87c476a2 | 4824 | bitmap_iterator bi; |
8b11a64c | 4825 | |
87c476a2 | 4826 | EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi) |
8b11a64c ZD |
4827 | { |
4828 | struct version_info *info; | |
4829 | ||
4830 | info = ver_info (data, i); | |
4831 | if (info->iv) | |
4832 | free (info->iv); | |
4833 | info->iv = NULL; | |
4834 | info->has_nonlin_use = false; | |
4835 | info->preserve_biv = false; | |
4836 | info->inv_id = 0; | |
87c476a2 | 4837 | } |
8b11a64c | 4838 | bitmap_clear (data->relevant); |
b1b02be2 | 4839 | bitmap_clear (data->important_candidates); |
8b11a64c ZD |
4840 | |
4841 | for (i = 0; i < n_iv_uses (data); i++) | |
4842 | { | |
4843 | struct iv_use *use = iv_use (data, i); | |
4844 | ||
4845 | free (use->iv); | |
4846 | BITMAP_XFREE (use->related_cands); | |
4847 | for (j = 0; j < use->n_map_members; j++) | |
4848 | if (use->cost_map[j].depends_on) | |
4849 | BITMAP_XFREE (use->cost_map[j].depends_on); | |
4850 | free (use->cost_map); | |
4851 | free (use); | |
4852 | } | |
4853 | VARRAY_POP_ALL (data->iv_uses); | |
4854 | ||
4855 | for (i = 0; i < n_iv_cands (data); i++) | |
4856 | { | |
4857 | struct iv_cand *cand = iv_cand (data, i); | |
4858 | ||
4859 | if (cand->iv) | |
4860 | free (cand->iv); | |
4861 | free (cand); | |
4862 | } | |
4863 | VARRAY_POP_ALL (data->iv_candidates); | |
4864 | ||
4865 | if (data->version_info_size < num_ssa_names) | |
4866 | { | |
4867 | data->version_info_size = 2 * num_ssa_names; | |
4868 | free (data->version_info); | |
4869 | data->version_info = xcalloc (data->version_info_size, | |
4870 | sizeof (struct version_info)); | |
4871 | } | |
4872 | ||
4873 | data->max_inv_id = 0; | |
4874 | ||
4875 | for (i = 0; i < VARRAY_ACTIVE_SIZE (decl_rtl_to_reset); i++) | |
4876 | { | |
4877 | tree obj = VARRAY_GENERIC_PTR_NOGC (decl_rtl_to_reset, i); | |
4878 | ||
4879 | SET_DECL_RTL (obj, NULL_RTX); | |
4880 | } | |
4881 | VARRAY_POP_ALL (decl_rtl_to_reset); | |
4882 | } | |
4883 | ||
4884 | /* Finalizes data structures used by the iv optimization pass. LOOPS is the | |
4885 | loop tree. */ | |
4886 | ||
4887 | static void | |
4888 | tree_ssa_iv_optimize_finalize (struct loops *loops, struct ivopts_data *data) | |
4889 | { | |
4890 | unsigned i; | |
4891 | ||
4892 | for (i = 1; i < loops->num; i++) | |
4893 | if (loops->parray[i]) | |
4894 | { | |
4895 | free (loops->parray[i]->aux); | |
4896 | loops->parray[i]->aux = NULL; | |
4897 | } | |
4898 | ||
4899 | free_loop_data (data); | |
4900 | free (data->version_info); | |
4901 | BITMAP_XFREE (data->relevant); | |
b1b02be2 | 4902 | BITMAP_XFREE (data->important_candidates); |
8b11a64c ZD |
4903 | |
4904 | VARRAY_FREE (decl_rtl_to_reset); | |
4905 | VARRAY_FREE (data->iv_uses); | |
4906 | VARRAY_FREE (data->iv_candidates); | |
4907 | } | |
4908 | ||
4909 | /* Optimizes the LOOP. Returns true if anything changed. */ | |
4910 | ||
4911 | static bool | |
4912 | tree_ssa_iv_optimize_loop (struct ivopts_data *data, struct loop *loop) | |
4913 | { | |
4914 | bool changed = false; | |
b1b02be2 | 4915 | struct iv_ca *iv_ca; |
8b11a64c ZD |
4916 | edge exit; |
4917 | ||
4918 | data->current_loop = loop; | |
4919 | ||
4920 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4921 | { | |
4922 | fprintf (dump_file, "Processing loop %d\n", loop->num); | |
4923 | ||
4924 | exit = single_dom_exit (loop); | |
4925 | if (exit) | |
4926 | { | |
4927 | fprintf (dump_file, " single exit %d -> %d, exit condition ", | |
4928 | exit->src->index, exit->dest->index); | |
4929 | print_generic_expr (dump_file, last_stmt (exit->src), TDF_SLIM); | |
4930 | fprintf (dump_file, "\n"); | |
4931 | } | |
4932 | ||
4933 | fprintf (dump_file, "\n"); | |
4934 | } | |
4935 | ||
4936 | /* For each ssa name determines whether it behaves as an induction variable | |
4937 | in some loop. */ | |
4938 | if (!find_induction_variables (data)) | |
4939 | goto finish; | |
4940 | ||
4941 | /* Finds interesting uses (item 1). */ | |
4942 | find_interesting_uses (data); | |
4943 | if (n_iv_uses (data) > MAX_CONSIDERED_USES) | |
4944 | goto finish; | |
4945 | ||
4946 | /* Finds candidates for the induction variables (item 2). */ | |
4947 | find_iv_candidates (data); | |
4948 | ||
4949 | /* Calculates the costs (item 3, part 1). */ | |
4950 | determine_use_iv_costs (data); | |
4951 | determine_iv_costs (data); | |
4952 | determine_set_costs (data); | |
4953 | ||
4954 | /* Find the optimal set of induction variables (item 3, part 2). */ | |
b1b02be2 ZD |
4955 | iv_ca = find_optimal_iv_set (data); |
4956 | if (!iv_ca) | |
8b11a64c ZD |
4957 | goto finish; |
4958 | changed = true; | |
4959 | ||
4960 | /* Create the new induction variables (item 4, part 1). */ | |
b1b02be2 ZD |
4961 | create_new_ivs (data, iv_ca); |
4962 | iv_ca_free (&iv_ca); | |
8b11a64c ZD |
4963 | |
4964 | /* Rewrite the uses (item 4, part 2). */ | |
4965 | rewrite_uses (data); | |
4966 | ||
4967 | /* Remove the ivs that are unused after rewriting. */ | |
4968 | remove_unused_ivs (data); | |
4969 | ||
4970 | loop_commit_inserts (); | |
4971 | ||
8b11a64c ZD |
4972 | /* We have changed the structure of induction variables; it might happen |
4973 | that definitions in the scev database refer to some of them that were | |
4974 | eliminated. */ | |
4975 | scev_reset (); | |
4976 | ||
4977 | finish: | |
4978 | free_loop_data (data); | |
4979 | ||
4980 | return changed; | |
4981 | } | |
4982 | ||
4983 | /* Main entry point. Optimizes induction variables in LOOPS. */ | |
4984 | ||
4985 | void | |
4986 | tree_ssa_iv_optimize (struct loops *loops) | |
4987 | { | |
4988 | struct loop *loop; | |
4989 | struct ivopts_data data; | |
4990 | ||
4991 | tree_ssa_iv_optimize_init (loops, &data); | |
4992 | ||
4993 | /* Optimize the loops starting with the innermost ones. */ | |
4994 | loop = loops->tree_root; | |
4995 | while (loop->inner) | |
4996 | loop = loop->inner; | |
4997 | ||
4998 | #ifdef ENABLE_CHECKING | |
4999 | verify_loop_closed_ssa (); | |
8679c649 | 5000 | verify_stmts (); |
8b11a64c ZD |
5001 | #endif |
5002 | ||
5003 | /* Scan the loops, inner ones first. */ | |
5004 | while (loop != loops->tree_root) | |
5005 | { | |
8679c649 JH |
5006 | if (dump_file && (dump_flags & TDF_DETAILS)) |
5007 | flow_loop_dump (loop, dump_file, NULL, 1); | |
e9472263 ZD |
5008 | |
5009 | tree_ssa_iv_optimize_loop (&data, loop); | |
8b11a64c ZD |
5010 | |
5011 | if (loop->next) | |
5012 | { | |
5013 | loop = loop->next; | |
5014 | while (loop->inner) | |
5015 | loop = loop->inner; | |
5016 | } | |
5017 | else | |
5018 | loop = loop->outer; | |
5019 | } | |
5020 | ||
e9472263 ZD |
5021 | #ifdef ENABLE_CHECKING |
5022 | verify_loop_closed_ssa (); | |
5023 | verify_stmts (); | |
5024 | #endif | |
5025 | ||
8b11a64c ZD |
5026 | tree_ssa_iv_optimize_finalize (loops, &data); |
5027 | } |