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8b11a64c | 1 | /* Induction variable optimizations. |
ad616de1 | 2 | Copyright (C) 2003, 2004, 2005 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" | |
39b4020c | 91 | #include "langhooks.h" |
8b11a64c ZD |
92 | |
93 | /* The infinite cost. */ | |
94 | #define INFTY 10000000 | |
95 | ||
96 | /* The expected number of loop iterations. TODO -- use profiling instead of | |
97 | this. */ | |
98 | #define AVG_LOOP_NITER(LOOP) 5 | |
99 | ||
8b11a64c ZD |
100 | |
101 | /* Representation of the induction variable. */ | |
102 | struct iv | |
103 | { | |
104 | tree base; /* Initial value of the iv. */ | |
e6845c23 | 105 | tree base_object; /* A memory object to that the induction variable points. */ |
8b11a64c ZD |
106 | tree step; /* Step of the iv (constant only). */ |
107 | tree ssa_name; /* The ssa name with the value. */ | |
108 | bool biv_p; /* Is it a biv? */ | |
109 | bool have_use_for; /* Do we already have a use for it? */ | |
110 | unsigned use_id; /* The identifier in the use if it is the case. */ | |
111 | }; | |
112 | ||
113 | /* Per-ssa version information (induction variable descriptions, etc.). */ | |
114 | struct version_info | |
115 | { | |
116 | tree name; /* The ssa name. */ | |
117 | struct iv *iv; /* Induction variable description. */ | |
118 | bool has_nonlin_use; /* For a loop-level invariant, whether it is used in | |
119 | an expression that is not an induction variable. */ | |
120 | unsigned inv_id; /* Id of an invariant. */ | |
121 | bool preserve_biv; /* For the original biv, whether to preserve it. */ | |
122 | }; | |
123 | ||
124 | /* Information attached to loop. */ | |
125 | struct loop_data | |
126 | { | |
8b11a64c ZD |
127 | unsigned regs_used; /* Number of registers used. */ |
128 | }; | |
129 | ||
130 | /* Types of uses. */ | |
131 | enum use_type | |
132 | { | |
133 | USE_NONLINEAR_EXPR, /* Use in a nonlinear expression. */ | |
134 | USE_OUTER, /* The induction variable is used outside the loop. */ | |
135 | USE_ADDRESS, /* Use in an address. */ | |
136 | USE_COMPARE /* Use is a compare. */ | |
137 | }; | |
138 | ||
139 | /* The candidate - cost pair. */ | |
140 | struct cost_pair | |
141 | { | |
142 | struct iv_cand *cand; /* The candidate. */ | |
143 | unsigned cost; /* The cost. */ | |
144 | bitmap depends_on; /* The list of invariants that have to be | |
145 | preserved. */ | |
146 | }; | |
147 | ||
148 | /* Use. */ | |
149 | struct iv_use | |
150 | { | |
151 | unsigned id; /* The id of the use. */ | |
152 | enum use_type type; /* Type of the use. */ | |
153 | struct iv *iv; /* The induction variable it is based on. */ | |
154 | tree stmt; /* Statement in that it occurs. */ | |
155 | tree *op_p; /* The place where it occurs. */ | |
b1b02be2 ZD |
156 | bitmap related_cands; /* The set of "related" iv candidates, plus the common |
157 | important ones. */ | |
8b11a64c ZD |
158 | |
159 | unsigned n_map_members; /* Number of candidates in the cost_map list. */ | |
160 | struct cost_pair *cost_map; | |
161 | /* The costs wrto the iv candidates. */ | |
162 | ||
163 | struct iv_cand *selected; | |
164 | /* The selected candidate. */ | |
165 | }; | |
166 | ||
167 | /* The position where the iv is computed. */ | |
168 | enum iv_position | |
169 | { | |
170 | IP_NORMAL, /* At the end, just before the exit condition. */ | |
171 | IP_END, /* At the end of the latch block. */ | |
172 | IP_ORIGINAL /* The original biv. */ | |
173 | }; | |
174 | ||
175 | /* The induction variable candidate. */ | |
176 | struct iv_cand | |
177 | { | |
178 | unsigned id; /* The number of the candidate. */ | |
179 | bool important; /* Whether this is an "important" candidate, i.e. such | |
180 | that it should be considered by all uses. */ | |
181 | enum iv_position pos; /* Where it is computed. */ | |
182 | tree incremented_at; /* For original biv, the statement where it is | |
183 | incremented. */ | |
184 | tree var_before; /* The variable used for it before increment. */ | |
185 | tree var_after; /* The variable used for it after increment. */ | |
186 | struct iv *iv; /* The value of the candidate. NULL for | |
187 | "pseudocandidate" used to indicate the possibility | |
188 | to replace the final value of an iv by direct | |
189 | computation of the value. */ | |
190 | unsigned cost; /* Cost of the candidate. */ | |
191 | }; | |
192 | ||
193 | /* The data used by the induction variable optimizations. */ | |
194 | ||
195 | struct ivopts_data | |
196 | { | |
197 | /* The currently optimized loop. */ | |
198 | struct loop *current_loop; | |
199 | ||
ca4c3169 ZD |
200 | /* Numbers of iterations for all exits of the current loop. */ |
201 | htab_t niters; | |
202 | ||
8b11a64c ZD |
203 | /* The size of version_info array allocated. */ |
204 | unsigned version_info_size; | |
205 | ||
206 | /* The array of information for the ssa names. */ | |
207 | struct version_info *version_info; | |
208 | ||
209 | /* The bitmap of indices in version_info whose value was changed. */ | |
210 | bitmap relevant; | |
211 | ||
212 | /* The maximum invariant id. */ | |
213 | unsigned max_inv_id; | |
214 | ||
215 | /* The uses of induction variables. */ | |
216 | varray_type iv_uses; | |
217 | ||
218 | /* The candidates. */ | |
219 | varray_type iv_candidates; | |
220 | ||
80cad5fa ZD |
221 | /* A bitmap of important candidates. */ |
222 | bitmap important_candidates; | |
223 | ||
8b11a64c ZD |
224 | /* Whether to consider just related and important candidates when replacing a |
225 | use. */ | |
226 | bool consider_all_candidates; | |
227 | }; | |
228 | ||
b1b02be2 ZD |
229 | /* An assignment of iv candidates to uses. */ |
230 | ||
231 | struct iv_ca | |
232 | { | |
233 | /* The number of uses covered by the assignment. */ | |
234 | unsigned upto; | |
235 | ||
236 | /* Number of uses that cannot be expressed by the candidates in the set. */ | |
237 | unsigned bad_uses; | |
238 | ||
239 | /* Candidate assigned to a use, together with the related costs. */ | |
240 | struct cost_pair **cand_for_use; | |
241 | ||
242 | /* Number of times each candidate is used. */ | |
243 | unsigned *n_cand_uses; | |
244 | ||
245 | /* The candidates used. */ | |
246 | bitmap cands; | |
247 | ||
36f5ada1 ZD |
248 | /* The number of candidates in the set. */ |
249 | unsigned n_cands; | |
250 | ||
b1b02be2 ZD |
251 | /* Total number of registers needed. */ |
252 | unsigned n_regs; | |
253 | ||
254 | /* Total cost of expressing uses. */ | |
255 | unsigned cand_use_cost; | |
256 | ||
257 | /* Total cost of candidates. */ | |
258 | unsigned cand_cost; | |
259 | ||
260 | /* Number of times each invariant is used. */ | |
261 | unsigned *n_invariant_uses; | |
262 | ||
263 | /* Total cost of the assignment. */ | |
264 | unsigned cost; | |
265 | }; | |
266 | ||
267 | /* Difference of two iv candidate assignments. */ | |
268 | ||
269 | struct iv_ca_delta | |
270 | { | |
271 | /* Changed use. */ | |
272 | struct iv_use *use; | |
273 | ||
274 | /* An old assignment (for rollback purposes). */ | |
275 | struct cost_pair *old_cp; | |
276 | ||
277 | /* A new assignment. */ | |
278 | struct cost_pair *new_cp; | |
279 | ||
280 | /* Next change in the list. */ | |
281 | struct iv_ca_delta *next_change; | |
282 | }; | |
283 | ||
8b11a64c ZD |
284 | /* Bound on number of candidates below that all candidates are considered. */ |
285 | ||
286 | #define CONSIDER_ALL_CANDIDATES_BOUND \ | |
287 | ((unsigned) PARAM_VALUE (PARAM_IV_CONSIDER_ALL_CANDIDATES_BOUND)) | |
288 | ||
2a7e31df | 289 | /* If there are more iv occurrences, we just give up (it is quite unlikely that |
8b11a64c ZD |
290 | optimizing such a loop would help, and it would take ages). */ |
291 | ||
292 | #define MAX_CONSIDERED_USES \ | |
293 | ((unsigned) PARAM_VALUE (PARAM_IV_MAX_CONSIDERED_USES)) | |
294 | ||
36f5ada1 ZD |
295 | /* If there are at most this number of ivs in the set, try removing unnecessary |
296 | ivs from the set always. */ | |
297 | ||
298 | #define ALWAYS_PRUNE_CAND_SET_BOUND \ | |
299 | ((unsigned) PARAM_VALUE (PARAM_IV_ALWAYS_PRUNE_CAND_SET_BOUND)) | |
300 | ||
8b11a64c ZD |
301 | /* The list of trees for that the decl_rtl field must be reset is stored |
302 | here. */ | |
303 | ||
304 | static varray_type decl_rtl_to_reset; | |
305 | ||
306 | /* Number of uses recorded in DATA. */ | |
307 | ||
308 | static inline unsigned | |
309 | n_iv_uses (struct ivopts_data *data) | |
310 | { | |
311 | return VARRAY_ACTIVE_SIZE (data->iv_uses); | |
312 | } | |
313 | ||
314 | /* Ith use recorded in DATA. */ | |
315 | ||
316 | static inline struct iv_use * | |
317 | iv_use (struct ivopts_data *data, unsigned i) | |
318 | { | |
319 | return VARRAY_GENERIC_PTR_NOGC (data->iv_uses, i); | |
320 | } | |
321 | ||
322 | /* Number of candidates recorded in DATA. */ | |
323 | ||
324 | static inline unsigned | |
325 | n_iv_cands (struct ivopts_data *data) | |
326 | { | |
327 | return VARRAY_ACTIVE_SIZE (data->iv_candidates); | |
328 | } | |
329 | ||
330 | /* Ith candidate recorded in DATA. */ | |
331 | ||
332 | static inline struct iv_cand * | |
333 | iv_cand (struct ivopts_data *data, unsigned i) | |
334 | { | |
335 | return VARRAY_GENERIC_PTR_NOGC (data->iv_candidates, i); | |
336 | } | |
337 | ||
338 | /* The data for LOOP. */ | |
339 | ||
340 | static inline struct loop_data * | |
341 | loop_data (struct loop *loop) | |
342 | { | |
343 | return loop->aux; | |
344 | } | |
345 | ||
346 | /* The single loop exit if it dominates the latch, NULL otherwise. */ | |
347 | ||
348 | static edge | |
349 | single_dom_exit (struct loop *loop) | |
350 | { | |
351 | edge exit = loop->single_exit; | |
352 | ||
353 | if (!exit) | |
354 | return NULL; | |
355 | ||
356 | if (!just_once_each_iteration_p (loop, exit->src)) | |
357 | return NULL; | |
358 | ||
359 | return exit; | |
360 | } | |
361 | ||
362 | /* Dumps information about the induction variable IV to FILE. */ | |
363 | ||
364 | extern void dump_iv (FILE *, struct iv *); | |
365 | void | |
366 | dump_iv (FILE *file, struct iv *iv) | |
367 | { | |
e6845c23 ZD |
368 | if (iv->ssa_name) |
369 | { | |
370 | fprintf (file, "ssa name "); | |
371 | print_generic_expr (file, iv->ssa_name, TDF_SLIM); | |
372 | fprintf (file, "\n"); | |
373 | } | |
8b11a64c | 374 | |
2f4675b4 ZD |
375 | fprintf (file, " type "); |
376 | print_generic_expr (file, TREE_TYPE (iv->base), TDF_SLIM); | |
377 | fprintf (file, "\n"); | |
378 | ||
8b11a64c ZD |
379 | if (iv->step) |
380 | { | |
381 | fprintf (file, " base "); | |
382 | print_generic_expr (file, iv->base, TDF_SLIM); | |
383 | fprintf (file, "\n"); | |
384 | ||
385 | fprintf (file, " step "); | |
386 | print_generic_expr (file, iv->step, TDF_SLIM); | |
387 | fprintf (file, "\n"); | |
388 | } | |
389 | else | |
390 | { | |
391 | fprintf (file, " invariant "); | |
392 | print_generic_expr (file, iv->base, TDF_SLIM); | |
393 | fprintf (file, "\n"); | |
394 | } | |
395 | ||
e6845c23 ZD |
396 | if (iv->base_object) |
397 | { | |
398 | fprintf (file, " base object "); | |
399 | print_generic_expr (file, iv->base_object, TDF_SLIM); | |
400 | fprintf (file, "\n"); | |
401 | } | |
402 | ||
8b11a64c ZD |
403 | if (iv->biv_p) |
404 | fprintf (file, " is a biv\n"); | |
405 | } | |
406 | ||
407 | /* Dumps information about the USE to FILE. */ | |
408 | ||
409 | extern void dump_use (FILE *, struct iv_use *); | |
410 | void | |
411 | dump_use (FILE *file, struct iv_use *use) | |
412 | { | |
8b11a64c ZD |
413 | fprintf (file, "use %d\n", use->id); |
414 | ||
415 | switch (use->type) | |
416 | { | |
417 | case USE_NONLINEAR_EXPR: | |
418 | fprintf (file, " generic\n"); | |
419 | break; | |
420 | ||
421 | case USE_OUTER: | |
422 | fprintf (file, " outside\n"); | |
423 | break; | |
424 | ||
425 | case USE_ADDRESS: | |
426 | fprintf (file, " address\n"); | |
427 | break; | |
428 | ||
429 | case USE_COMPARE: | |
430 | fprintf (file, " compare\n"); | |
431 | break; | |
432 | ||
433 | default: | |
1e128c5f | 434 | gcc_unreachable (); |
8b11a64c ZD |
435 | } |
436 | ||
2f4675b4 ZD |
437 | fprintf (file, " in statement "); |
438 | print_generic_expr (file, use->stmt, TDF_SLIM); | |
439 | fprintf (file, "\n"); | |
440 | ||
441 | fprintf (file, " at position "); | |
442 | if (use->op_p) | |
443 | print_generic_expr (file, *use->op_p, TDF_SLIM); | |
444 | fprintf (file, "\n"); | |
445 | ||
e6845c23 | 446 | dump_iv (file, use->iv); |
2f4675b4 | 447 | |
eec5fec9 ZD |
448 | if (use->related_cands) |
449 | { | |
450 | fprintf (file, " related candidates "); | |
451 | dump_bitmap (file, use->related_cands); | |
452 | } | |
8b11a64c ZD |
453 | } |
454 | ||
455 | /* Dumps information about the uses to FILE. */ | |
456 | ||
457 | extern void dump_uses (FILE *, struct ivopts_data *); | |
458 | void | |
459 | dump_uses (FILE *file, struct ivopts_data *data) | |
460 | { | |
461 | unsigned i; | |
462 | struct iv_use *use; | |
463 | ||
464 | for (i = 0; i < n_iv_uses (data); i++) | |
465 | { | |
466 | use = iv_use (data, i); | |
467 | ||
468 | dump_use (file, use); | |
469 | fprintf (file, "\n"); | |
470 | } | |
471 | } | |
472 | ||
473 | /* Dumps information about induction variable candidate CAND to FILE. */ | |
474 | ||
475 | extern void dump_cand (FILE *, struct iv_cand *); | |
476 | void | |
477 | dump_cand (FILE *file, struct iv_cand *cand) | |
478 | { | |
479 | struct iv *iv = cand->iv; | |
480 | ||
481 | fprintf (file, "candidate %d%s\n", | |
482 | cand->id, cand->important ? " (important)" : ""); | |
483 | ||
484 | if (!iv) | |
485 | { | |
486 | fprintf (file, " final value replacement\n"); | |
487 | return; | |
488 | } | |
489 | ||
490 | switch (cand->pos) | |
491 | { | |
492 | case IP_NORMAL: | |
493 | fprintf (file, " incremented before exit test\n"); | |
494 | break; | |
495 | ||
496 | case IP_END: | |
497 | fprintf (file, " incremented at end\n"); | |
498 | break; | |
499 | ||
500 | case IP_ORIGINAL: | |
501 | fprintf (file, " original biv\n"); | |
502 | break; | |
503 | } | |
504 | ||
e6845c23 | 505 | dump_iv (file, iv); |
8b11a64c ZD |
506 | } |
507 | ||
508 | /* Returns the info for ssa version VER. */ | |
509 | ||
510 | static inline struct version_info * | |
511 | ver_info (struct ivopts_data *data, unsigned ver) | |
512 | { | |
513 | return data->version_info + ver; | |
514 | } | |
515 | ||
516 | /* Returns the info for ssa name NAME. */ | |
517 | ||
518 | static inline struct version_info * | |
519 | name_info (struct ivopts_data *data, tree name) | |
520 | { | |
521 | return ver_info (data, SSA_NAME_VERSION (name)); | |
522 | } | |
523 | ||
524 | /* Checks whether there exists number X such that X * B = A, counting modulo | |
525 | 2^BITS. */ | |
526 | ||
527 | static bool | |
528 | divide (unsigned bits, unsigned HOST_WIDE_INT a, unsigned HOST_WIDE_INT b, | |
529 | HOST_WIDE_INT *x) | |
530 | { | |
531 | unsigned HOST_WIDE_INT mask = ~(~(unsigned HOST_WIDE_INT) 0 << (bits - 1) << 1); | |
532 | unsigned HOST_WIDE_INT inv, ex, val; | |
533 | unsigned i; | |
534 | ||
535 | a &= mask; | |
536 | b &= mask; | |
537 | ||
538 | /* First divide the whole equation by 2 as long as possible. */ | |
539 | while (!(a & 1) && !(b & 1)) | |
540 | { | |
541 | a >>= 1; | |
542 | b >>= 1; | |
543 | bits--; | |
544 | mask >>= 1; | |
545 | } | |
546 | ||
547 | if (!(b & 1)) | |
548 | { | |
549 | /* If b is still even, a is odd and there is no such x. */ | |
550 | return false; | |
551 | } | |
552 | ||
553 | /* Find the inverse of b. We compute it as | |
554 | b^(2^(bits - 1) - 1) (mod 2^bits). */ | |
555 | inv = 1; | |
556 | ex = b; | |
557 | for (i = 0; i < bits - 1; i++) | |
558 | { | |
559 | inv = (inv * ex) & mask; | |
560 | ex = (ex * ex) & mask; | |
561 | } | |
562 | ||
563 | val = (a * inv) & mask; | |
564 | ||
1e128c5f | 565 | gcc_assert (((val * b) & mask) == a); |
8b11a64c ZD |
566 | |
567 | if ((val >> (bits - 1)) & 1) | |
568 | val |= ~mask; | |
569 | ||
570 | *x = val; | |
571 | ||
572 | return true; | |
573 | } | |
574 | ||
575 | /* Returns true if STMT is after the place where the IP_NORMAL ivs will be | |
576 | emitted in LOOP. */ | |
577 | ||
578 | static bool | |
579 | stmt_after_ip_normal_pos (struct loop *loop, tree stmt) | |
580 | { | |
581 | basic_block bb = ip_normal_pos (loop), sbb = bb_for_stmt (stmt); | |
582 | ||
1e128c5f | 583 | gcc_assert (bb); |
8b11a64c ZD |
584 | |
585 | if (sbb == loop->latch) | |
586 | return true; | |
587 | ||
588 | if (sbb != bb) | |
589 | return false; | |
590 | ||
591 | return stmt == last_stmt (bb); | |
592 | } | |
593 | ||
594 | /* Returns true if STMT if after the place where the original induction | |
595 | variable CAND is incremented. */ | |
596 | ||
597 | static bool | |
598 | stmt_after_ip_original_pos (struct iv_cand *cand, tree stmt) | |
599 | { | |
600 | basic_block cand_bb = bb_for_stmt (cand->incremented_at); | |
601 | basic_block stmt_bb = bb_for_stmt (stmt); | |
602 | block_stmt_iterator bsi; | |
603 | ||
604 | if (!dominated_by_p (CDI_DOMINATORS, stmt_bb, cand_bb)) | |
605 | return false; | |
606 | ||
607 | if (stmt_bb != cand_bb) | |
608 | return true; | |
609 | ||
610 | /* Scan the block from the end, since the original ivs are usually | |
611 | incremented at the end of the loop body. */ | |
612 | for (bsi = bsi_last (stmt_bb); ; bsi_prev (&bsi)) | |
613 | { | |
614 | if (bsi_stmt (bsi) == cand->incremented_at) | |
615 | return false; | |
616 | if (bsi_stmt (bsi) == stmt) | |
617 | return true; | |
618 | } | |
619 | } | |
620 | ||
621 | /* Returns true if STMT if after the place where the induction variable | |
622 | CAND is incremented in LOOP. */ | |
623 | ||
624 | static bool | |
625 | stmt_after_increment (struct loop *loop, struct iv_cand *cand, tree stmt) | |
626 | { | |
627 | switch (cand->pos) | |
628 | { | |
629 | case IP_END: | |
630 | return false; | |
631 | ||
632 | case IP_NORMAL: | |
633 | return stmt_after_ip_normal_pos (loop, stmt); | |
634 | ||
635 | case IP_ORIGINAL: | |
636 | return stmt_after_ip_original_pos (cand, stmt); | |
637 | ||
638 | default: | |
1e128c5f | 639 | gcc_unreachable (); |
8b11a64c ZD |
640 | } |
641 | } | |
642 | ||
ca4c3169 ZD |
643 | /* Element of the table in that we cache the numbers of iterations obtained |
644 | from exits of the loop. */ | |
645 | ||
646 | struct nfe_cache_elt | |
647 | { | |
648 | /* The edge for that the number of iterations is cached. */ | |
649 | edge exit; | |
650 | ||
0388d40a | 651 | /* True if the # of iterations was successfully determined. */ |
ca4c3169 ZD |
652 | bool valid_p; |
653 | ||
654 | /* Description of # of iterations. */ | |
655 | struct tree_niter_desc niter; | |
656 | }; | |
657 | ||
658 | /* Hash function for nfe_cache_elt E. */ | |
659 | ||
660 | static hashval_t | |
661 | nfe_hash (const void *e) | |
662 | { | |
663 | const struct nfe_cache_elt *elt = e; | |
664 | ||
665 | return htab_hash_pointer (elt->exit); | |
666 | } | |
667 | ||
668 | /* Equality function for nfe_cache_elt E1 and edge E2. */ | |
669 | ||
670 | static int | |
671 | nfe_eq (const void *e1, const void *e2) | |
672 | { | |
673 | const struct nfe_cache_elt *elt1 = e1; | |
674 | ||
675 | return elt1->exit == e2; | |
676 | } | |
677 | ||
678 | /* Returns structure describing number of iterations determined from | |
679 | EXIT of DATA->current_loop, or NULL if something goes wrong. */ | |
680 | ||
681 | static struct tree_niter_desc * | |
682 | niter_for_exit (struct ivopts_data *data, edge exit) | |
683 | { | |
684 | struct nfe_cache_elt *nfe_desc; | |
685 | PTR *slot; | |
686 | ||
687 | slot = htab_find_slot_with_hash (data->niters, exit, | |
688 | htab_hash_pointer (exit), | |
689 | INSERT); | |
690 | ||
691 | if (!*slot) | |
692 | { | |
693 | nfe_desc = xmalloc (sizeof (struct nfe_cache_elt)); | |
694 | nfe_desc->exit = exit; | |
695 | nfe_desc->valid_p = number_of_iterations_exit (data->current_loop, | |
696 | exit, &nfe_desc->niter); | |
697 | *slot = nfe_desc; | |
698 | } | |
699 | else | |
700 | nfe_desc = *slot; | |
701 | ||
702 | if (!nfe_desc->valid_p) | |
703 | return NULL; | |
704 | ||
705 | return &nfe_desc->niter; | |
706 | } | |
707 | ||
708 | /* Returns structure describing number of iterations determined from | |
709 | single dominating exit of DATA->current_loop, or NULL if something | |
710 | goes wrong. */ | |
711 | ||
712 | static struct tree_niter_desc * | |
713 | niter_for_single_dom_exit (struct ivopts_data *data) | |
714 | { | |
715 | edge exit = single_dom_exit (data->current_loop); | |
716 | ||
717 | if (!exit) | |
718 | return NULL; | |
719 | ||
720 | return niter_for_exit (data, exit); | |
721 | } | |
722 | ||
8b11a64c ZD |
723 | /* Initializes data structures used by the iv optimization pass, stored |
724 | in DATA. LOOPS is the loop tree. */ | |
725 | ||
726 | static void | |
727 | tree_ssa_iv_optimize_init (struct loops *loops, struct ivopts_data *data) | |
728 | { | |
729 | unsigned i; | |
730 | ||
731 | data->version_info_size = 2 * num_ssa_names; | |
732 | data->version_info = xcalloc (data->version_info_size, | |
733 | sizeof (struct version_info)); | |
8bdbfff5 NS |
734 | data->relevant = BITMAP_ALLOC (NULL); |
735 | data->important_candidates = BITMAP_ALLOC (NULL); | |
8b11a64c | 736 | data->max_inv_id = 0; |
ca4c3169 | 737 | data->niters = htab_create (10, nfe_hash, nfe_eq, free); |
8b11a64c ZD |
738 | |
739 | for (i = 1; i < loops->num; i++) | |
740 | if (loops->parray[i]) | |
741 | loops->parray[i]->aux = xcalloc (1, sizeof (struct loop_data)); | |
742 | ||
743 | VARRAY_GENERIC_PTR_NOGC_INIT (data->iv_uses, 20, "iv_uses"); | |
744 | VARRAY_GENERIC_PTR_NOGC_INIT (data->iv_candidates, 20, "iv_candidates"); | |
745 | VARRAY_GENERIC_PTR_NOGC_INIT (decl_rtl_to_reset, 20, "decl_rtl_to_reset"); | |
746 | } | |
747 | ||
e6845c23 ZD |
748 | /* Returns a memory object to that EXPR points. In case we are able to |
749 | determine that it does not point to any such object, NULL is returned. */ | |
750 | ||
751 | static tree | |
752 | determine_base_object (tree expr) | |
753 | { | |
754 | enum tree_code code = TREE_CODE (expr); | |
755 | tree base, obj, op0, op1; | |
756 | ||
757 | if (!POINTER_TYPE_P (TREE_TYPE (expr))) | |
758 | return NULL_TREE; | |
759 | ||
760 | switch (code) | |
761 | { | |
762 | case INTEGER_CST: | |
763 | return NULL_TREE; | |
764 | ||
765 | case ADDR_EXPR: | |
766 | obj = TREE_OPERAND (expr, 0); | |
767 | base = get_base_address (obj); | |
768 | ||
769 | if (!base) | |
f5e2738c | 770 | return expr; |
e6845c23 | 771 | |
7299dbfb | 772 | if (TREE_CODE (base) == INDIRECT_REF) |
f5e2738c | 773 | return determine_base_object (TREE_OPERAND (base, 0)); |
7299dbfb | 774 | |
e6845c23 ZD |
775 | return fold (build1 (ADDR_EXPR, ptr_type_node, base)); |
776 | ||
777 | case PLUS_EXPR: | |
778 | case MINUS_EXPR: | |
779 | op0 = determine_base_object (TREE_OPERAND (expr, 0)); | |
780 | op1 = determine_base_object (TREE_OPERAND (expr, 1)); | |
781 | ||
782 | if (!op1) | |
783 | return op0; | |
784 | ||
785 | if (!op0) | |
786 | return (code == PLUS_EXPR | |
787 | ? op1 | |
788 | : fold (build1 (NEGATE_EXPR, ptr_type_node, op1))); | |
789 | ||
790 | return fold (build (code, ptr_type_node, op0, op1)); | |
791 | ||
f5e2738c ZD |
792 | case NOP_EXPR: |
793 | case CONVERT_EXPR: | |
794 | return determine_base_object (TREE_OPERAND (expr, 0)); | |
795 | ||
e6845c23 ZD |
796 | default: |
797 | return fold_convert (ptr_type_node, expr); | |
798 | } | |
799 | } | |
800 | ||
8b11a64c ZD |
801 | /* Allocates an induction variable with given initial value BASE and step STEP |
802 | for loop LOOP. */ | |
803 | ||
804 | static struct iv * | |
805 | alloc_iv (tree base, tree step) | |
806 | { | |
807 | struct iv *iv = xcalloc (1, sizeof (struct iv)); | |
808 | ||
809 | if (step && integer_zerop (step)) | |
810 | step = NULL_TREE; | |
811 | ||
812 | iv->base = base; | |
e6845c23 | 813 | iv->base_object = determine_base_object (base); |
8b11a64c ZD |
814 | iv->step = step; |
815 | iv->biv_p = false; | |
816 | iv->have_use_for = false; | |
817 | iv->use_id = 0; | |
818 | iv->ssa_name = NULL_TREE; | |
819 | ||
820 | return iv; | |
821 | } | |
822 | ||
823 | /* Sets STEP and BASE for induction variable IV. */ | |
824 | ||
825 | static void | |
826 | set_iv (struct ivopts_data *data, tree iv, tree base, tree step) | |
827 | { | |
828 | struct version_info *info = name_info (data, iv); | |
829 | ||
1e128c5f | 830 | gcc_assert (!info->iv); |
8b11a64c ZD |
831 | |
832 | bitmap_set_bit (data->relevant, SSA_NAME_VERSION (iv)); | |
833 | info->iv = alloc_iv (base, step); | |
834 | info->iv->ssa_name = iv; | |
835 | } | |
836 | ||
837 | /* Finds induction variable declaration for VAR. */ | |
838 | ||
839 | static struct iv * | |
840 | get_iv (struct ivopts_data *data, tree var) | |
841 | { | |
842 | basic_block bb; | |
843 | ||
844 | if (!name_info (data, var)->iv) | |
845 | { | |
846 | bb = bb_for_stmt (SSA_NAME_DEF_STMT (var)); | |
847 | ||
848 | if (!bb | |
849 | || !flow_bb_inside_loop_p (data->current_loop, bb)) | |
850 | set_iv (data, var, var, NULL_TREE); | |
851 | } | |
852 | ||
853 | return name_info (data, var)->iv; | |
854 | } | |
855 | ||
856 | /* Determines the step of a biv defined in PHI. */ | |
857 | ||
858 | static tree | |
859 | determine_biv_step (tree phi) | |
860 | { | |
861 | struct loop *loop = bb_for_stmt (phi)->loop_father; | |
862 | tree name = PHI_RESULT (phi), base, step; | |
863 | tree type = TREE_TYPE (name); | |
864 | ||
865 | if (!is_gimple_reg (name)) | |
866 | return NULL_TREE; | |
867 | ||
868 | if (!simple_iv (loop, phi, name, &base, &step)) | |
869 | return NULL_TREE; | |
870 | ||
871 | if (!step) | |
5212068f | 872 | return build_int_cst (type, 0); |
8b11a64c ZD |
873 | |
874 | return step; | |
875 | } | |
876 | ||
be35cf60 ZD |
877 | /* Returns true if EXP is a ssa name that occurs in an abnormal phi node. */ |
878 | ||
879 | static bool | |
880 | abnormal_ssa_name_p (tree exp) | |
881 | { | |
882 | if (!exp) | |
883 | return false; | |
884 | ||
885 | if (TREE_CODE (exp) != SSA_NAME) | |
886 | return false; | |
887 | ||
888 | return SSA_NAME_OCCURS_IN_ABNORMAL_PHI (exp) != 0; | |
889 | } | |
890 | ||
891 | /* Returns false if BASE or INDEX contains a ssa name that occurs in an | |
8b11a64c ZD |
892 | abnormal phi node. Callback for for_each_index. */ |
893 | ||
894 | static bool | |
be35cf60 | 895 | idx_contains_abnormal_ssa_name_p (tree base, tree *index, |
8b11a64c ZD |
896 | void *data ATTRIBUTE_UNUSED) |
897 | { | |
be35cf60 ZD |
898 | if (TREE_CODE (base) == ARRAY_REF) |
899 | { | |
900 | if (abnormal_ssa_name_p (TREE_OPERAND (base, 2))) | |
901 | return false; | |
902 | if (abnormal_ssa_name_p (TREE_OPERAND (base, 3))) | |
903 | return false; | |
904 | } | |
8b11a64c | 905 | |
be35cf60 | 906 | return !abnormal_ssa_name_p (*index); |
8b11a64c ZD |
907 | } |
908 | ||
909 | /* Returns true if EXPR contains a ssa name that occurs in an | |
910 | abnormal phi node. */ | |
911 | ||
912 | static bool | |
913 | contains_abnormal_ssa_name_p (tree expr) | |
914 | { | |
915 | enum tree_code code = TREE_CODE (expr); | |
6615c446 | 916 | enum tree_code_class class = TREE_CODE_CLASS (code); |
8b11a64c ZD |
917 | |
918 | if (code == SSA_NAME) | |
919 | return SSA_NAME_OCCURS_IN_ABNORMAL_PHI (expr) != 0; | |
920 | ||
921 | if (code == INTEGER_CST | |
922 | || is_gimple_min_invariant (expr)) | |
923 | return false; | |
924 | ||
925 | if (code == ADDR_EXPR) | |
6efa2c71 | 926 | return !for_each_index (&TREE_OPERAND (expr, 0), |
8b11a64c ZD |
927 | idx_contains_abnormal_ssa_name_p, |
928 | NULL); | |
929 | ||
930 | switch (class) | |
931 | { | |
6615c446 JO |
932 | case tcc_binary: |
933 | case tcc_comparison: | |
8b11a64c ZD |
934 | if (contains_abnormal_ssa_name_p (TREE_OPERAND (expr, 1))) |
935 | return true; | |
936 | ||
937 | /* Fallthru. */ | |
6615c446 | 938 | case tcc_unary: |
8b11a64c ZD |
939 | if (contains_abnormal_ssa_name_p (TREE_OPERAND (expr, 0))) |
940 | return true; | |
941 | ||
942 | break; | |
943 | ||
944 | default: | |
1e128c5f | 945 | gcc_unreachable (); |
8b11a64c ZD |
946 | } |
947 | ||
948 | return false; | |
949 | } | |
950 | ||
951 | /* Finds basic ivs. */ | |
952 | ||
953 | static bool | |
954 | find_bivs (struct ivopts_data *data) | |
955 | { | |
956 | tree phi, step, type, base; | |
957 | bool found = false; | |
958 | struct loop *loop = data->current_loop; | |
959 | ||
bb29d951 | 960 | for (phi = phi_nodes (loop->header); phi; phi = PHI_CHAIN (phi)) |
8b11a64c ZD |
961 | { |
962 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (PHI_RESULT (phi))) | |
963 | continue; | |
964 | ||
965 | step = determine_biv_step (phi); | |
966 | ||
967 | if (!step) | |
968 | continue; | |
969 | if (cst_and_fits_in_hwi (step) | |
970 | && int_cst_value (step) == 0) | |
971 | continue; | |
972 | ||
973 | base = PHI_ARG_DEF_FROM_EDGE (phi, loop_preheader_edge (loop)); | |
974 | if (contains_abnormal_ssa_name_p (base)) | |
975 | continue; | |
976 | ||
977 | type = TREE_TYPE (PHI_RESULT (phi)); | |
978 | base = fold_convert (type, base); | |
979 | step = fold_convert (type, step); | |
980 | ||
981 | /* FIXME: We do not handle induction variables whose step does | |
982 | not satisfy cst_and_fits_in_hwi. */ | |
983 | if (!cst_and_fits_in_hwi (step)) | |
984 | continue; | |
985 | ||
986 | set_iv (data, PHI_RESULT (phi), base, step); | |
987 | found = true; | |
988 | } | |
989 | ||
990 | return found; | |
991 | } | |
992 | ||
993 | /* Marks basic ivs. */ | |
994 | ||
995 | static void | |
996 | mark_bivs (struct ivopts_data *data) | |
997 | { | |
998 | tree phi, var; | |
999 | struct iv *iv, *incr_iv; | |
1000 | struct loop *loop = data->current_loop; | |
1001 | basic_block incr_bb; | |
1002 | ||
bb29d951 | 1003 | for (phi = phi_nodes (loop->header); phi; phi = PHI_CHAIN (phi)) |
8b11a64c ZD |
1004 | { |
1005 | iv = get_iv (data, PHI_RESULT (phi)); | |
1006 | if (!iv) | |
1007 | continue; | |
1008 | ||
1009 | var = PHI_ARG_DEF_FROM_EDGE (phi, loop_latch_edge (loop)); | |
1010 | incr_iv = get_iv (data, var); | |
1011 | if (!incr_iv) | |
1012 | continue; | |
1013 | ||
1014 | /* If the increment is in the subloop, ignore it. */ | |
1015 | incr_bb = bb_for_stmt (SSA_NAME_DEF_STMT (var)); | |
1016 | if (incr_bb->loop_father != data->current_loop | |
1017 | || (incr_bb->flags & BB_IRREDUCIBLE_LOOP)) | |
1018 | continue; | |
1019 | ||
1020 | iv->biv_p = true; | |
1021 | incr_iv->biv_p = true; | |
1022 | } | |
1023 | } | |
1024 | ||
1025 | /* Checks whether STMT defines a linear induction variable and stores its | |
1026 | parameters to BASE and STEP. */ | |
1027 | ||
1028 | static bool | |
1029 | find_givs_in_stmt_scev (struct ivopts_data *data, tree stmt, | |
1030 | tree *base, tree *step) | |
1031 | { | |
1032 | tree lhs; | |
1033 | struct loop *loop = data->current_loop; | |
1034 | ||
1035 | *base = NULL_TREE; | |
1036 | *step = NULL_TREE; | |
1037 | ||
1038 | if (TREE_CODE (stmt) != MODIFY_EXPR) | |
1039 | return false; | |
1040 | ||
1041 | lhs = TREE_OPERAND (stmt, 0); | |
1042 | if (TREE_CODE (lhs) != SSA_NAME) | |
1043 | return false; | |
1044 | ||
1045 | if (!simple_iv (loop, stmt, TREE_OPERAND (stmt, 1), base, step)) | |
1046 | return false; | |
1047 | ||
1048 | /* FIXME: We do not handle induction variables whose step does | |
1049 | not satisfy cst_and_fits_in_hwi. */ | |
1050 | if (!zero_p (*step) | |
1051 | && !cst_and_fits_in_hwi (*step)) | |
1052 | return false; | |
1053 | ||
1054 | if (contains_abnormal_ssa_name_p (*base)) | |
1055 | return false; | |
1056 | ||
1057 | return true; | |
1058 | } | |
1059 | ||
1060 | /* Finds general ivs in statement STMT. */ | |
1061 | ||
1062 | static void | |
1063 | find_givs_in_stmt (struct ivopts_data *data, tree stmt) | |
1064 | { | |
1065 | tree base, step; | |
1066 | ||
1067 | if (!find_givs_in_stmt_scev (data, stmt, &base, &step)) | |
1068 | return; | |
1069 | ||
1070 | set_iv (data, TREE_OPERAND (stmt, 0), base, step); | |
1071 | } | |
1072 | ||
1073 | /* Finds general ivs in basic block BB. */ | |
1074 | ||
1075 | static void | |
1076 | find_givs_in_bb (struct ivopts_data *data, basic_block bb) | |
1077 | { | |
1078 | block_stmt_iterator bsi; | |
1079 | ||
1080 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
1081 | find_givs_in_stmt (data, bsi_stmt (bsi)); | |
1082 | } | |
1083 | ||
1084 | /* Finds general ivs. */ | |
1085 | ||
1086 | static void | |
1087 | find_givs (struct ivopts_data *data) | |
1088 | { | |
1089 | struct loop *loop = data->current_loop; | |
1090 | basic_block *body = get_loop_body_in_dom_order (loop); | |
1091 | unsigned i; | |
1092 | ||
1093 | for (i = 0; i < loop->num_nodes; i++) | |
1094 | find_givs_in_bb (data, body[i]); | |
1095 | free (body); | |
1096 | } | |
1097 | ||
8b11a64c ZD |
1098 | /* For each ssa name defined in LOOP determines whether it is an induction |
1099 | variable and if so, its initial value and step. */ | |
1100 | ||
1101 | static bool | |
1102 | find_induction_variables (struct ivopts_data *data) | |
1103 | { | |
1104 | unsigned i; | |
87c476a2 | 1105 | bitmap_iterator bi; |
8b11a64c ZD |
1106 | |
1107 | if (!find_bivs (data)) | |
1108 | return false; | |
1109 | ||
1110 | find_givs (data); | |
1111 | mark_bivs (data); | |
8b11a64c ZD |
1112 | |
1113 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1114 | { | |
ca4c3169 ZD |
1115 | struct tree_niter_desc *niter; |
1116 | ||
1117 | niter = niter_for_single_dom_exit (data); | |
1118 | ||
1119 | if (niter) | |
8b11a64c ZD |
1120 | { |
1121 | fprintf (dump_file, " number of iterations "); | |
ca4c3169 | 1122 | print_generic_expr (dump_file, niter->niter, TDF_SLIM); |
8b11a64c ZD |
1123 | fprintf (dump_file, "\n"); |
1124 | ||
1125 | fprintf (dump_file, " may be zero if "); | |
ca4c3169 | 1126 | print_generic_expr (dump_file, niter->may_be_zero, TDF_SLIM); |
8b11a64c ZD |
1127 | fprintf (dump_file, "\n"); |
1128 | fprintf (dump_file, "\n"); | |
1129 | }; | |
1130 | ||
1131 | fprintf (dump_file, "Induction variables:\n\n"); | |
1132 | ||
87c476a2 | 1133 | EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi) |
8b11a64c ZD |
1134 | { |
1135 | if (ver_info (data, i)->iv) | |
1136 | dump_iv (dump_file, ver_info (data, i)->iv); | |
87c476a2 | 1137 | } |
8b11a64c ZD |
1138 | } |
1139 | ||
1140 | return true; | |
1141 | } | |
1142 | ||
1143 | /* Records a use of type USE_TYPE at *USE_P in STMT whose value is IV. */ | |
1144 | ||
1145 | static struct iv_use * | |
1146 | record_use (struct ivopts_data *data, tree *use_p, struct iv *iv, | |
1147 | tree stmt, enum use_type use_type) | |
1148 | { | |
1149 | struct iv_use *use = xcalloc (1, sizeof (struct iv_use)); | |
1150 | ||
1151 | use->id = n_iv_uses (data); | |
1152 | use->type = use_type; | |
1153 | use->iv = iv; | |
1154 | use->stmt = stmt; | |
1155 | use->op_p = use_p; | |
8bdbfff5 | 1156 | use->related_cands = BITMAP_ALLOC (NULL); |
8b11a64c | 1157 | |
e6845c23 ZD |
1158 | /* To avoid showing ssa name in the dumps, if it was not reset by the |
1159 | caller. */ | |
1160 | iv->ssa_name = NULL_TREE; | |
1161 | ||
8b11a64c ZD |
1162 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1163 | dump_use (dump_file, use); | |
1164 | ||
1165 | VARRAY_PUSH_GENERIC_PTR_NOGC (data->iv_uses, use); | |
1166 | ||
1167 | return use; | |
1168 | } | |
1169 | ||
1170 | /* Checks whether OP is a loop-level invariant and if so, records it. | |
1171 | NONLINEAR_USE is true if the invariant is used in a way we do not | |
1172 | handle specially. */ | |
1173 | ||
1174 | static void | |
1175 | record_invariant (struct ivopts_data *data, tree op, bool nonlinear_use) | |
1176 | { | |
1177 | basic_block bb; | |
1178 | struct version_info *info; | |
1179 | ||
1180 | if (TREE_CODE (op) != SSA_NAME | |
1181 | || !is_gimple_reg (op)) | |
1182 | return; | |
1183 | ||
1184 | bb = bb_for_stmt (SSA_NAME_DEF_STMT (op)); | |
1185 | if (bb | |
1186 | && flow_bb_inside_loop_p (data->current_loop, bb)) | |
1187 | return; | |
1188 | ||
1189 | info = name_info (data, op); | |
1190 | info->name = op; | |
1191 | info->has_nonlin_use |= nonlinear_use; | |
1192 | if (!info->inv_id) | |
1193 | info->inv_id = ++data->max_inv_id; | |
1194 | bitmap_set_bit (data->relevant, SSA_NAME_VERSION (op)); | |
1195 | } | |
1196 | ||
1197 | /* Checks whether the use OP is interesting and if so, records it | |
1198 | as TYPE. */ | |
1199 | ||
1200 | static struct iv_use * | |
1201 | find_interesting_uses_outer_or_nonlin (struct ivopts_data *data, tree op, | |
1202 | enum use_type type) | |
1203 | { | |
1204 | struct iv *iv; | |
1205 | struct iv *civ; | |
1206 | tree stmt; | |
1207 | struct iv_use *use; | |
1208 | ||
1209 | if (TREE_CODE (op) != SSA_NAME) | |
1210 | return NULL; | |
1211 | ||
1212 | iv = get_iv (data, op); | |
1213 | if (!iv) | |
1214 | return NULL; | |
1215 | ||
1216 | if (iv->have_use_for) | |
1217 | { | |
1218 | use = iv_use (data, iv->use_id); | |
1219 | ||
1e128c5f GB |
1220 | gcc_assert (use->type == USE_NONLINEAR_EXPR |
1221 | || use->type == USE_OUTER); | |
8b11a64c ZD |
1222 | |
1223 | if (type == USE_NONLINEAR_EXPR) | |
1224 | use->type = USE_NONLINEAR_EXPR; | |
1225 | return use; | |
1226 | } | |
1227 | ||
1228 | if (zero_p (iv->step)) | |
1229 | { | |
1230 | record_invariant (data, op, true); | |
1231 | return NULL; | |
1232 | } | |
1233 | iv->have_use_for = true; | |
1234 | ||
1235 | civ = xmalloc (sizeof (struct iv)); | |
1236 | *civ = *iv; | |
1237 | ||
1238 | stmt = SSA_NAME_DEF_STMT (op); | |
1e128c5f GB |
1239 | gcc_assert (TREE_CODE (stmt) == PHI_NODE |
1240 | || TREE_CODE (stmt) == MODIFY_EXPR); | |
8b11a64c ZD |
1241 | |
1242 | use = record_use (data, NULL, civ, stmt, type); | |
1243 | iv->use_id = use->id; | |
1244 | ||
1245 | return use; | |
1246 | } | |
1247 | ||
1248 | /* Checks whether the use OP is interesting and if so, records it. */ | |
1249 | ||
1250 | static struct iv_use * | |
1251 | find_interesting_uses_op (struct ivopts_data *data, tree op) | |
1252 | { | |
1253 | return find_interesting_uses_outer_or_nonlin (data, op, USE_NONLINEAR_EXPR); | |
1254 | } | |
1255 | ||
1256 | /* Records a definition of induction variable OP that is used outside of the | |
1257 | loop. */ | |
1258 | ||
1259 | static struct iv_use * | |
1260 | find_interesting_uses_outer (struct ivopts_data *data, tree op) | |
1261 | { | |
1262 | return find_interesting_uses_outer_or_nonlin (data, op, USE_OUTER); | |
1263 | } | |
1264 | ||
1265 | /* Checks whether the condition *COND_P in STMT is interesting | |
1266 | and if so, records it. */ | |
1267 | ||
1268 | static void | |
1269 | find_interesting_uses_cond (struct ivopts_data *data, tree stmt, tree *cond_p) | |
1270 | { | |
1271 | tree *op0_p; | |
1272 | tree *op1_p; | |
1273 | struct iv *iv0 = NULL, *iv1 = NULL, *civ; | |
1274 | struct iv const_iv; | |
1275 | tree zero = integer_zero_node; | |
1276 | ||
1277 | const_iv.step = NULL_TREE; | |
1278 | ||
1279 | if (integer_zerop (*cond_p) | |
1280 | || integer_nonzerop (*cond_p)) | |
1281 | return; | |
1282 | ||
1283 | if (TREE_CODE (*cond_p) == SSA_NAME) | |
1284 | { | |
1285 | op0_p = cond_p; | |
1286 | op1_p = &zero; | |
1287 | } | |
1288 | else | |
1289 | { | |
1290 | op0_p = &TREE_OPERAND (*cond_p, 0); | |
1291 | op1_p = &TREE_OPERAND (*cond_p, 1); | |
1292 | } | |
1293 | ||
1294 | if (TREE_CODE (*op0_p) == SSA_NAME) | |
1295 | iv0 = get_iv (data, *op0_p); | |
1296 | else | |
1297 | iv0 = &const_iv; | |
1298 | ||
1299 | if (TREE_CODE (*op1_p) == SSA_NAME) | |
1300 | iv1 = get_iv (data, *op1_p); | |
1301 | else | |
1302 | iv1 = &const_iv; | |
1303 | ||
1304 | if (/* When comparing with non-invariant value, we may not do any senseful | |
1305 | induction variable elimination. */ | |
1306 | (!iv0 || !iv1) | |
1307 | /* Eliminating condition based on two ivs would be nontrivial. | |
1308 | ??? TODO -- it is not really important to handle this case. */ | |
1309 | || (!zero_p (iv0->step) && !zero_p (iv1->step))) | |
1310 | { | |
1311 | find_interesting_uses_op (data, *op0_p); | |
1312 | find_interesting_uses_op (data, *op1_p); | |
1313 | return; | |
1314 | } | |
1315 | ||
1316 | if (zero_p (iv0->step) && zero_p (iv1->step)) | |
1317 | { | |
1318 | /* If both are invariants, this is a work for unswitching. */ | |
1319 | return; | |
1320 | } | |
1321 | ||
1322 | civ = xmalloc (sizeof (struct iv)); | |
1323 | *civ = zero_p (iv0->step) ? *iv1: *iv0; | |
1324 | record_use (data, cond_p, civ, stmt, USE_COMPARE); | |
1325 | } | |
1326 | ||
be35cf60 ZD |
1327 | /* Returns true if expression EXPR is obviously invariant in LOOP, |
1328 | i.e. if all its operands are defined outside of the LOOP. */ | |
1329 | ||
feb075f4 | 1330 | bool |
be35cf60 ZD |
1331 | expr_invariant_in_loop_p (struct loop *loop, tree expr) |
1332 | { | |
1333 | basic_block def_bb; | |
1334 | unsigned i, len; | |
1335 | ||
1336 | if (is_gimple_min_invariant (expr)) | |
1337 | return true; | |
1338 | ||
1339 | if (TREE_CODE (expr) == SSA_NAME) | |
1340 | { | |
1341 | def_bb = bb_for_stmt (SSA_NAME_DEF_STMT (expr)); | |
1342 | if (def_bb | |
1343 | && flow_bb_inside_loop_p (loop, def_bb)) | |
1344 | return false; | |
1345 | ||
1346 | return true; | |
1347 | } | |
1348 | ||
1349 | if (!EXPR_P (expr)) | |
1350 | return false; | |
1351 | ||
54e4aedb | 1352 | len = TREE_CODE_LENGTH (TREE_CODE (expr)); |
be35cf60 ZD |
1353 | for (i = 0; i < len; i++) |
1354 | if (!expr_invariant_in_loop_p (loop, TREE_OPERAND (expr, i))) | |
1355 | return false; | |
1356 | ||
1357 | return true; | |
1358 | } | |
1359 | ||
8b11a64c ZD |
1360 | /* Cumulates the steps of indices into DATA and replaces their values with the |
1361 | initial ones. Returns false when the value of the index cannot be determined. | |
1362 | Callback for for_each_index. */ | |
1363 | ||
1364 | struct ifs_ivopts_data | |
1365 | { | |
1366 | struct ivopts_data *ivopts_data; | |
1367 | tree stmt; | |
1368 | tree *step_p; | |
1369 | }; | |
1370 | ||
1371 | static bool | |
1372 | idx_find_step (tree base, tree *idx, void *data) | |
1373 | { | |
1374 | struct ifs_ivopts_data *dta = data; | |
1375 | struct iv *iv; | |
be35cf60 | 1376 | tree step, type, iv_type, iv_step, lbound, off; |
2f4675b4 | 1377 | struct loop *loop = dta->ivopts_data->current_loop; |
be35cf60 ZD |
1378 | |
1379 | if (TREE_CODE (base) == MISALIGNED_INDIRECT_REF | |
1380 | || TREE_CODE (base) == ALIGN_INDIRECT_REF) | |
1381 | return false; | |
1382 | ||
1383 | /* If base is a component ref, require that the offset of the reference | |
3a7c155d | 1384 | be invariant. */ |
be35cf60 ZD |
1385 | if (TREE_CODE (base) == COMPONENT_REF) |
1386 | { | |
1387 | off = component_ref_field_offset (base); | |
1388 | return expr_invariant_in_loop_p (loop, off); | |
1389 | } | |
1390 | ||
1391 | /* If base is array, first check whether we will be able to move the | |
1392 | reference out of the loop (in order to take its address in strength | |
1393 | reduction). In order for this to work we need both lower bound | |
1394 | and step to be loop invariants. */ | |
1395 | if (TREE_CODE (base) == ARRAY_REF) | |
1396 | { | |
1397 | step = array_ref_element_size (base); | |
1398 | lbound = array_ref_low_bound (base); | |
1399 | ||
1400 | if (!expr_invariant_in_loop_p (loop, step) | |
1401 | || !expr_invariant_in_loop_p (loop, lbound)) | |
1402 | return false; | |
1403 | } | |
1404 | ||
8b11a64c ZD |
1405 | if (TREE_CODE (*idx) != SSA_NAME) |
1406 | return true; | |
1407 | ||
1408 | iv = get_iv (dta->ivopts_data, *idx); | |
1409 | if (!iv) | |
1410 | return false; | |
1411 | ||
1412 | *idx = iv->base; | |
1413 | ||
1414 | if (!iv->step) | |
1415 | return true; | |
1416 | ||
1417 | iv_type = TREE_TYPE (iv->base); | |
1418 | type = build_pointer_type (TREE_TYPE (base)); | |
1419 | if (TREE_CODE (base) == ARRAY_REF) | |
2f4675b4 ZD |
1420 | { |
1421 | step = array_ref_element_size (base); | |
2f4675b4 ZD |
1422 | |
1423 | /* We only handle addresses whose step is an integer constant. */ | |
1424 | if (TREE_CODE (step) != INTEGER_CST) | |
1425 | return false; | |
2f4675b4 | 1426 | } |
8b11a64c | 1427 | else |
5212068f NS |
1428 | /* The step for pointer arithmetics already is 1 byte. */ |
1429 | step = build_int_cst (type, 1); | |
8b11a64c ZD |
1430 | |
1431 | if (TYPE_PRECISION (iv_type) < TYPE_PRECISION (type)) | |
1432 | iv_step = can_count_iv_in_wider_type (dta->ivopts_data->current_loop, | |
1433 | type, iv->base, iv->step, dta->stmt); | |
1434 | else | |
1435 | iv_step = fold_convert (iv_type, iv->step); | |
1436 | ||
1437 | if (!iv_step) | |
1438 | { | |
1439 | /* The index might wrap. */ | |
1440 | return false; | |
1441 | } | |
1442 | ||
b52d5eaa | 1443 | step = fold_binary_to_constant (MULT_EXPR, type, step, iv_step); |
8b11a64c ZD |
1444 | |
1445 | if (!*dta->step_p) | |
1446 | *dta->step_p = step; | |
1447 | else | |
b52d5eaa RS |
1448 | *dta->step_p = fold_binary_to_constant (PLUS_EXPR, type, |
1449 | *dta->step_p, step); | |
8b11a64c ZD |
1450 | |
1451 | return true; | |
1452 | } | |
1453 | ||
1454 | /* Records use in index IDX. Callback for for_each_index. Ivopts data | |
1455 | object is passed to it in DATA. */ | |
1456 | ||
1457 | static bool | |
2f4675b4 | 1458 | idx_record_use (tree base, tree *idx, |
8b11a64c ZD |
1459 | void *data) |
1460 | { | |
1461 | find_interesting_uses_op (data, *idx); | |
2f4675b4 ZD |
1462 | if (TREE_CODE (base) == ARRAY_REF) |
1463 | { | |
1464 | find_interesting_uses_op (data, array_ref_element_size (base)); | |
1465 | find_interesting_uses_op (data, array_ref_low_bound (base)); | |
1466 | } | |
8b11a64c ZD |
1467 | return true; |
1468 | } | |
1469 | ||
0a915e3d ZD |
1470 | /* Returns true if memory reference REF may be unaligned. */ |
1471 | ||
1472 | static bool | |
1473 | may_be_unaligned_p (tree ref) | |
1474 | { | |
1475 | tree base; | |
1476 | tree base_type; | |
1477 | HOST_WIDE_INT bitsize; | |
1478 | HOST_WIDE_INT bitpos; | |
1479 | tree toffset; | |
1480 | enum machine_mode mode; | |
1481 | int unsignedp, volatilep; | |
1482 | unsigned base_align; | |
1483 | ||
1484 | /* The test below is basically copy of what expr.c:normal_inner_ref | |
1485 | does to check whether the object must be loaded by parts when | |
1486 | STRICT_ALIGNMENT is true. */ | |
1487 | base = get_inner_reference (ref, &bitsize, &bitpos, &toffset, &mode, | |
1488 | &unsignedp, &volatilep, true); | |
1489 | base_type = TREE_TYPE (base); | |
1490 | base_align = TYPE_ALIGN (base_type); | |
1491 | ||
1492 | if (mode != BLKmode | |
1493 | && (base_align < GET_MODE_ALIGNMENT (mode) | |
1494 | || bitpos % GET_MODE_ALIGNMENT (mode) != 0 | |
1495 | || bitpos % BITS_PER_UNIT != 0)) | |
1496 | return true; | |
1497 | ||
1498 | return false; | |
1499 | } | |
1500 | ||
8b11a64c ZD |
1501 | /* Finds addresses in *OP_P inside STMT. */ |
1502 | ||
1503 | static void | |
1504 | find_interesting_uses_address (struct ivopts_data *data, tree stmt, tree *op_p) | |
1505 | { | |
1506 | tree base = unshare_expr (*op_p), step = NULL; | |
1507 | struct iv *civ; | |
1508 | struct ifs_ivopts_data ifs_ivopts_data; | |
1509 | ||
1510 | /* Ignore bitfields for now. Not really something terribly complicated | |
1511 | to handle. TODO. */ | |
1512 | if (TREE_CODE (base) == COMPONENT_REF | |
1513 | && DECL_NONADDRESSABLE_P (TREE_OPERAND (base, 1))) | |
1514 | goto fail; | |
1515 | ||
0a915e3d ZD |
1516 | if (STRICT_ALIGNMENT |
1517 | && may_be_unaligned_p (base)) | |
1518 | goto fail; | |
1519 | ||
8b11a64c ZD |
1520 | ifs_ivopts_data.ivopts_data = data; |
1521 | ifs_ivopts_data.stmt = stmt; | |
1522 | ifs_ivopts_data.step_p = &step; | |
1523 | if (!for_each_index (&base, idx_find_step, &ifs_ivopts_data) | |
1524 | || zero_p (step)) | |
1525 | goto fail; | |
1526 | ||
be35cf60 ZD |
1527 | gcc_assert (TREE_CODE (base) != ALIGN_INDIRECT_REF); |
1528 | gcc_assert (TREE_CODE (base) != MISALIGNED_INDIRECT_REF); | |
1529 | ||
1530 | if (TREE_CODE (base) == INDIRECT_REF) | |
8b11a64c ZD |
1531 | base = TREE_OPERAND (base, 0); |
1532 | else | |
1533 | base = build_addr (base); | |
1534 | ||
1535 | civ = alloc_iv (base, step); | |
1536 | record_use (data, op_p, civ, stmt, USE_ADDRESS); | |
1537 | return; | |
1538 | ||
1539 | fail: | |
1540 | for_each_index (op_p, idx_record_use, data); | |
1541 | } | |
1542 | ||
1543 | /* Finds and records invariants used in STMT. */ | |
1544 | ||
1545 | static void | |
1546 | find_invariants_stmt (struct ivopts_data *data, tree stmt) | |
1547 | { | |
1548 | use_optype uses = NULL; | |
1549 | unsigned i, n; | |
1550 | tree op; | |
1551 | ||
1552 | if (TREE_CODE (stmt) == PHI_NODE) | |
1553 | n = PHI_NUM_ARGS (stmt); | |
1554 | else | |
1555 | { | |
8b11a64c ZD |
1556 | uses = STMT_USE_OPS (stmt); |
1557 | n = NUM_USES (uses); | |
1558 | } | |
1559 | ||
1560 | for (i = 0; i < n; i++) | |
1561 | { | |
1562 | if (TREE_CODE (stmt) == PHI_NODE) | |
1563 | op = PHI_ARG_DEF (stmt, i); | |
1564 | else | |
1565 | op = USE_OP (uses, i); | |
1566 | ||
1567 | record_invariant (data, op, false); | |
1568 | } | |
1569 | } | |
1570 | ||
1571 | /* Finds interesting uses of induction variables in the statement STMT. */ | |
1572 | ||
1573 | static void | |
1574 | find_interesting_uses_stmt (struct ivopts_data *data, tree stmt) | |
1575 | { | |
1576 | struct iv *iv; | |
1577 | tree op, lhs, rhs; | |
1578 | use_optype uses = NULL; | |
1579 | unsigned i, n; | |
1580 | ||
1581 | find_invariants_stmt (data, stmt); | |
1582 | ||
1583 | if (TREE_CODE (stmt) == COND_EXPR) | |
1584 | { | |
1585 | find_interesting_uses_cond (data, stmt, &COND_EXPR_COND (stmt)); | |
1586 | return; | |
1587 | } | |
1588 | ||
1589 | if (TREE_CODE (stmt) == MODIFY_EXPR) | |
1590 | { | |
1591 | lhs = TREE_OPERAND (stmt, 0); | |
1592 | rhs = TREE_OPERAND (stmt, 1); | |
1593 | ||
1594 | if (TREE_CODE (lhs) == SSA_NAME) | |
1595 | { | |
1596 | /* If the statement defines an induction variable, the uses are not | |
1597 | interesting by themselves. */ | |
1598 | ||
1599 | iv = get_iv (data, lhs); | |
1600 | ||
1601 | if (iv && !zero_p (iv->step)) | |
1602 | return; | |
1603 | } | |
1604 | ||
1605 | switch (TREE_CODE_CLASS (TREE_CODE (rhs))) | |
1606 | { | |
6615c446 | 1607 | case tcc_comparison: |
8b11a64c ZD |
1608 | find_interesting_uses_cond (data, stmt, &TREE_OPERAND (stmt, 1)); |
1609 | return; | |
1610 | ||
6615c446 | 1611 | case tcc_reference: |
8b11a64c | 1612 | find_interesting_uses_address (data, stmt, &TREE_OPERAND (stmt, 1)); |
6615c446 | 1613 | if (REFERENCE_CLASS_P (lhs)) |
8b11a64c ZD |
1614 | find_interesting_uses_address (data, stmt, &TREE_OPERAND (stmt, 0)); |
1615 | return; | |
1616 | ||
1617 | default: ; | |
1618 | } | |
1619 | ||
6615c446 | 1620 | if (REFERENCE_CLASS_P (lhs) |
2f4675b4 | 1621 | && is_gimple_val (rhs)) |
8b11a64c ZD |
1622 | { |
1623 | find_interesting_uses_address (data, stmt, &TREE_OPERAND (stmt, 0)); | |
1624 | find_interesting_uses_op (data, rhs); | |
1625 | return; | |
1626 | } | |
2f4675b4 ZD |
1627 | |
1628 | /* TODO -- we should also handle address uses of type | |
1629 | ||
1630 | memory = call (whatever); | |
1631 | ||
1632 | and | |
1633 | ||
1634 | call (memory). */ | |
8b11a64c ZD |
1635 | } |
1636 | ||
1637 | if (TREE_CODE (stmt) == PHI_NODE | |
1638 | && bb_for_stmt (stmt) == data->current_loop->header) | |
1639 | { | |
1640 | lhs = PHI_RESULT (stmt); | |
1641 | iv = get_iv (data, lhs); | |
1642 | ||
1643 | if (iv && !zero_p (iv->step)) | |
1644 | return; | |
1645 | } | |
1646 | ||
1647 | if (TREE_CODE (stmt) == PHI_NODE) | |
1648 | n = PHI_NUM_ARGS (stmt); | |
1649 | else | |
1650 | { | |
1651 | uses = STMT_USE_OPS (stmt); | |
1652 | n = NUM_USES (uses); | |
1653 | } | |
1654 | ||
1655 | for (i = 0; i < n; i++) | |
1656 | { | |
1657 | if (TREE_CODE (stmt) == PHI_NODE) | |
1658 | op = PHI_ARG_DEF (stmt, i); | |
1659 | else | |
1660 | op = USE_OP (uses, i); | |
1661 | ||
1662 | if (TREE_CODE (op) != SSA_NAME) | |
1663 | continue; | |
1664 | ||
1665 | iv = get_iv (data, op); | |
1666 | if (!iv) | |
1667 | continue; | |
1668 | ||
1669 | find_interesting_uses_op (data, op); | |
1670 | } | |
1671 | } | |
1672 | ||
1673 | /* Finds interesting uses of induction variables outside of loops | |
1674 | on loop exit edge EXIT. */ | |
1675 | ||
1676 | static void | |
1677 | find_interesting_uses_outside (struct ivopts_data *data, edge exit) | |
1678 | { | |
1679 | tree phi, def; | |
1680 | ||
bb29d951 | 1681 | for (phi = phi_nodes (exit->dest); phi; phi = PHI_CHAIN (phi)) |
8b11a64c ZD |
1682 | { |
1683 | def = PHI_ARG_DEF_FROM_EDGE (phi, exit); | |
1684 | find_interesting_uses_outer (data, def); | |
1685 | } | |
1686 | } | |
1687 | ||
1688 | /* Finds uses of the induction variables that are interesting. */ | |
1689 | ||
1690 | static void | |
1691 | find_interesting_uses (struct ivopts_data *data) | |
1692 | { | |
1693 | basic_block bb; | |
1694 | block_stmt_iterator bsi; | |
1695 | tree phi; | |
1696 | basic_block *body = get_loop_body (data->current_loop); | |
1697 | unsigned i; | |
1698 | struct version_info *info; | |
1699 | edge e; | |
1700 | ||
1701 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1702 | fprintf (dump_file, "Uses:\n\n"); | |
1703 | ||
1704 | for (i = 0; i < data->current_loop->num_nodes; i++) | |
1705 | { | |
628f6a4e | 1706 | edge_iterator ei; |
8b11a64c ZD |
1707 | bb = body[i]; |
1708 | ||
628f6a4e | 1709 | FOR_EACH_EDGE (e, ei, bb->succs) |
8b11a64c ZD |
1710 | if (e->dest != EXIT_BLOCK_PTR |
1711 | && !flow_bb_inside_loop_p (data->current_loop, e->dest)) | |
1712 | find_interesting_uses_outside (data, e); | |
1713 | ||
bb29d951 | 1714 | for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) |
8b11a64c ZD |
1715 | find_interesting_uses_stmt (data, phi); |
1716 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
1717 | find_interesting_uses_stmt (data, bsi_stmt (bsi)); | |
1718 | } | |
1719 | ||
1720 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1721 | { | |
87c476a2 ZD |
1722 | bitmap_iterator bi; |
1723 | ||
8b11a64c ZD |
1724 | fprintf (dump_file, "\n"); |
1725 | ||
87c476a2 | 1726 | EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi) |
8b11a64c ZD |
1727 | { |
1728 | info = ver_info (data, i); | |
1729 | if (info->inv_id) | |
1730 | { | |
1731 | fprintf (dump_file, " "); | |
1732 | print_generic_expr (dump_file, info->name, TDF_SLIM); | |
1733 | fprintf (dump_file, " is invariant (%d)%s\n", | |
1734 | info->inv_id, info->has_nonlin_use ? "" : ", eliminable"); | |
1735 | } | |
87c476a2 | 1736 | } |
8b11a64c ZD |
1737 | |
1738 | fprintf (dump_file, "\n"); | |
1739 | } | |
1740 | ||
1741 | free (body); | |
1742 | } | |
1743 | ||
f5e2738c ZD |
1744 | /* Strips constant offsets from EXPR and stores them to OFFSET. If INSIDE_ADDR |
1745 | is true, assume we are inside an address. */ | |
1746 | ||
1747 | static tree | |
1748 | strip_offset (tree expr, bool inside_addr, unsigned HOST_WIDE_INT *offset) | |
1749 | { | |
1750 | tree op0 = NULL_TREE, op1 = NULL_TREE, step; | |
1751 | enum tree_code code; | |
1752 | tree type, orig_type = TREE_TYPE (expr); | |
1753 | unsigned HOST_WIDE_INT off0, off1, st; | |
1754 | tree orig_expr = expr; | |
1755 | ||
1756 | STRIP_NOPS (expr); | |
1757 | type = TREE_TYPE (expr); | |
1758 | code = TREE_CODE (expr); | |
1759 | *offset = 0; | |
1760 | ||
1761 | switch (code) | |
1762 | { | |
1763 | case INTEGER_CST: | |
1764 | if (!cst_and_fits_in_hwi (expr) | |
1765 | || zero_p (expr)) | |
1766 | return orig_expr; | |
1767 | ||
1768 | *offset = int_cst_value (expr); | |
1769 | return build_int_cst_type (orig_type, 0); | |
1770 | ||
1771 | case PLUS_EXPR: | |
1772 | case MINUS_EXPR: | |
1773 | op0 = TREE_OPERAND (expr, 0); | |
1774 | op1 = TREE_OPERAND (expr, 1); | |
1775 | ||
1776 | op0 = strip_offset (op0, false, &off0); | |
1777 | op1 = strip_offset (op1, false, &off1); | |
1778 | ||
1779 | *offset = (code == PLUS_EXPR ? off0 + off1 : off0 - off1); | |
1780 | if (op0 == TREE_OPERAND (expr, 0) | |
1781 | && op1 == TREE_OPERAND (expr, 1)) | |
1782 | return orig_expr; | |
1783 | ||
1784 | if (zero_p (op1)) | |
1785 | expr = op0; | |
1786 | else if (zero_p (op0)) | |
1787 | { | |
1788 | if (code == PLUS_EXPR) | |
1789 | expr = op1; | |
1790 | else | |
1791 | expr = build1 (NEGATE_EXPR, type, op1); | |
1792 | } | |
1793 | else | |
1794 | expr = build2 (code, type, op0, op1); | |
1795 | ||
1796 | return fold_convert (orig_type, expr); | |
1797 | ||
1798 | case ARRAY_REF: | |
1799 | if (!inside_addr) | |
1800 | return orig_expr; | |
1801 | ||
1802 | step = array_ref_element_size (expr); | |
1803 | if (!cst_and_fits_in_hwi (step)) | |
1804 | break; | |
1805 | ||
1806 | st = int_cst_value (step); | |
1807 | op1 = TREE_OPERAND (expr, 1); | |
1808 | op1 = strip_offset (op1, false, &off1); | |
1809 | *offset = off1 * st; | |
1810 | break; | |
1811 | ||
1812 | case COMPONENT_REF: | |
1813 | if (!inside_addr) | |
1814 | return orig_expr; | |
1815 | break; | |
1816 | ||
1817 | case ADDR_EXPR: | |
1818 | inside_addr = true; | |
1819 | break; | |
1820 | ||
1821 | default: | |
1822 | return orig_expr; | |
1823 | } | |
1824 | ||
1825 | /* Default handling of expressions for that we want to recurse into | |
1826 | the first operand. */ | |
1827 | op0 = TREE_OPERAND (expr, 0); | |
1828 | op0 = strip_offset (op0, inside_addr, &off0); | |
1829 | *offset += off0; | |
1830 | ||
1831 | if (op0 == TREE_OPERAND (expr, 0) | |
1832 | && (!op1 || op1 == TREE_OPERAND (expr, 1))) | |
1833 | return orig_expr; | |
1834 | ||
1835 | expr = copy_node (expr); | |
1836 | TREE_OPERAND (expr, 0) = op0; | |
1837 | if (op1) | |
1838 | TREE_OPERAND (expr, 1) = op1; | |
1839 | ||
1840 | return fold_convert (orig_type, expr); | |
1841 | } | |
1842 | ||
d482f417 ZD |
1843 | /* Returns variant of TYPE that can be used as base for different uses. |
1844 | For integer types, we return unsigned variant of the type, which | |
1845 | avoids problems with overflows. For pointer types, we return void *. */ | |
1846 | ||
1847 | static tree | |
1848 | generic_type_for (tree type) | |
1849 | { | |
1850 | if (POINTER_TYPE_P (type)) | |
1851 | return ptr_type_node; | |
1852 | ||
1853 | if (TYPE_UNSIGNED (type)) | |
1854 | return type; | |
1855 | ||
1856 | return unsigned_type_for (type); | |
1857 | } | |
1858 | ||
8b11a64c ZD |
1859 | /* Adds a candidate BASE + STEP * i. Important field is set to IMPORTANT and |
1860 | position to POS. If USE is not NULL, the candidate is set as related to | |
1861 | it. If both BASE and STEP are NULL, we add a pseudocandidate for the | |
1862 | replacement of the final value of the iv by a direct computation. */ | |
1863 | ||
1864 | static struct iv_cand * | |
1865 | add_candidate_1 (struct ivopts_data *data, | |
1866 | tree base, tree step, bool important, enum iv_position pos, | |
1867 | struct iv_use *use, tree incremented_at) | |
1868 | { | |
1869 | unsigned i; | |
1870 | struct iv_cand *cand = NULL; | |
d482f417 | 1871 | tree type, orig_type; |
8b11a64c ZD |
1872 | |
1873 | if (base) | |
1874 | { | |
d482f417 ZD |
1875 | orig_type = TREE_TYPE (base); |
1876 | type = generic_type_for (orig_type); | |
1877 | if (type != orig_type) | |
8b11a64c | 1878 | { |
8b11a64c ZD |
1879 | base = fold_convert (type, base); |
1880 | if (step) | |
1881 | step = fold_convert (type, step); | |
1882 | } | |
1883 | } | |
1884 | ||
1885 | for (i = 0; i < n_iv_cands (data); i++) | |
1886 | { | |
1887 | cand = iv_cand (data, i); | |
1888 | ||
1889 | if (cand->pos != pos) | |
1890 | continue; | |
1891 | ||
1892 | if (cand->incremented_at != incremented_at) | |
1893 | continue; | |
1894 | ||
1895 | if (!cand->iv) | |
1896 | { | |
1897 | if (!base && !step) | |
1898 | break; | |
1899 | ||
1900 | continue; | |
1901 | } | |
1902 | ||
1903 | if (!base && !step) | |
1904 | continue; | |
1905 | ||
1906 | if (!operand_equal_p (base, cand->iv->base, 0)) | |
1907 | continue; | |
1908 | ||
1909 | if (zero_p (cand->iv->step)) | |
1910 | { | |
1911 | if (zero_p (step)) | |
1912 | break; | |
1913 | } | |
1914 | else | |
1915 | { | |
1916 | if (step && operand_equal_p (step, cand->iv->step, 0)) | |
1917 | break; | |
1918 | } | |
1919 | } | |
1920 | ||
1921 | if (i == n_iv_cands (data)) | |
1922 | { | |
1923 | cand = xcalloc (1, sizeof (struct iv_cand)); | |
1924 | cand->id = i; | |
1925 | ||
1926 | if (!base && !step) | |
1927 | cand->iv = NULL; | |
1928 | else | |
1929 | cand->iv = alloc_iv (base, step); | |
1930 | ||
1931 | cand->pos = pos; | |
1932 | if (pos != IP_ORIGINAL && cand->iv) | |
1933 | { | |
1934 | cand->var_before = create_tmp_var_raw (TREE_TYPE (base), "ivtmp"); | |
1935 | cand->var_after = cand->var_before; | |
1936 | } | |
1937 | cand->important = important; | |
1938 | cand->incremented_at = incremented_at; | |
1939 | VARRAY_PUSH_GENERIC_PTR_NOGC (data->iv_candidates, cand); | |
1940 | ||
1941 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1942 | dump_cand (dump_file, cand); | |
1943 | } | |
1944 | ||
1945 | if (important && !cand->important) | |
1946 | { | |
1947 | cand->important = true; | |
1948 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1949 | fprintf (dump_file, "Candidate %d is important\n", cand->id); | |
1950 | } | |
1951 | ||
1952 | if (use) | |
1953 | { | |
1954 | bitmap_set_bit (use->related_cands, i); | |
1955 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1956 | fprintf (dump_file, "Candidate %d is related to use %d\n", | |
1957 | cand->id, use->id); | |
1958 | } | |
1959 | ||
1960 | return cand; | |
1961 | } | |
1962 | ||
4366cf6d ZD |
1963 | /* Returns true if incrementing the induction variable at the end of the LOOP |
1964 | is allowed. | |
1965 | ||
1966 | The purpose is to avoid splitting latch edge with a biv increment, thus | |
1967 | creating a jump, possibly confusing other optimization passes and leaving | |
1968 | less freedom to scheduler. So we allow IP_END_POS only if IP_NORMAL_POS | |
1969 | is not available (so we do not have a better alternative), or if the latch | |
1970 | edge is already nonempty. */ | |
1971 | ||
1972 | static bool | |
1973 | allow_ip_end_pos_p (struct loop *loop) | |
1974 | { | |
1975 | if (!ip_normal_pos (loop)) | |
1976 | return true; | |
1977 | ||
1978 | if (!empty_block_p (ip_end_pos (loop))) | |
1979 | return true; | |
1980 | ||
1981 | return false; | |
1982 | } | |
1983 | ||
8b11a64c ZD |
1984 | /* Adds a candidate BASE + STEP * i. Important field is set to IMPORTANT and |
1985 | position to POS. If USE is not NULL, the candidate is set as related to | |
1986 | it. The candidate computation is scheduled on all available positions. */ | |
1987 | ||
1988 | static void | |
1989 | add_candidate (struct ivopts_data *data, | |
1990 | tree base, tree step, bool important, struct iv_use *use) | |
1991 | { | |
1992 | if (ip_normal_pos (data->current_loop)) | |
1993 | add_candidate_1 (data, base, step, important, IP_NORMAL, use, NULL_TREE); | |
4366cf6d ZD |
1994 | if (ip_end_pos (data->current_loop) |
1995 | && allow_ip_end_pos_p (data->current_loop)) | |
8b11a64c ZD |
1996 | add_candidate_1 (data, base, step, important, IP_END, use, NULL_TREE); |
1997 | } | |
1998 | ||
39b4020c RS |
1999 | /* Add a standard "0 + 1 * iteration" iv candidate for a |
2000 | type with SIZE bits. */ | |
2001 | ||
2002 | static void | |
2003 | add_standard_iv_candidates_for_size (struct ivopts_data *data, | |
2004 | unsigned int size) | |
2005 | { | |
2006 | tree type = lang_hooks.types.type_for_size (size, true); | |
2007 | add_candidate (data, build_int_cst (type, 0), build_int_cst (type, 1), | |
2008 | true, NULL); | |
2009 | } | |
2010 | ||
8b11a64c ZD |
2011 | /* Adds standard iv candidates. */ |
2012 | ||
2013 | static void | |
2014 | add_standard_iv_candidates (struct ivopts_data *data) | |
2015 | { | |
39b4020c | 2016 | add_standard_iv_candidates_for_size (data, INT_TYPE_SIZE); |
8b11a64c | 2017 | |
39b4020c RS |
2018 | /* The same for a double-integer type if it is still fast enough. */ |
2019 | if (BITS_PER_WORD >= INT_TYPE_SIZE * 2) | |
2020 | add_standard_iv_candidates_for_size (data, INT_TYPE_SIZE * 2); | |
8b11a64c ZD |
2021 | } |
2022 | ||
2023 | ||
2024 | /* Adds candidates bases on the old induction variable IV. */ | |
2025 | ||
2026 | static void | |
2027 | add_old_iv_candidates (struct ivopts_data *data, struct iv *iv) | |
2028 | { | |
2029 | tree phi, def; | |
2030 | struct iv_cand *cand; | |
2031 | ||
2032 | add_candidate (data, iv->base, iv->step, true, NULL); | |
2033 | ||
2034 | /* The same, but with initial value zero. */ | |
2035 | add_candidate (data, | |
5212068f | 2036 | build_int_cst (TREE_TYPE (iv->base), 0), |
8b11a64c ZD |
2037 | iv->step, true, NULL); |
2038 | ||
2039 | phi = SSA_NAME_DEF_STMT (iv->ssa_name); | |
2040 | if (TREE_CODE (phi) == PHI_NODE) | |
2041 | { | |
2042 | /* Additionally record the possibility of leaving the original iv | |
2043 | untouched. */ | |
2044 | def = PHI_ARG_DEF_FROM_EDGE (phi, loop_latch_edge (data->current_loop)); | |
2045 | cand = add_candidate_1 (data, | |
2046 | iv->base, iv->step, true, IP_ORIGINAL, NULL, | |
2047 | SSA_NAME_DEF_STMT (def)); | |
2048 | cand->var_before = iv->ssa_name; | |
2049 | cand->var_after = def; | |
2050 | } | |
2051 | } | |
2052 | ||
2053 | /* Adds candidates based on the old induction variables. */ | |
2054 | ||
2055 | static void | |
2056 | add_old_ivs_candidates (struct ivopts_data *data) | |
2057 | { | |
2058 | unsigned i; | |
2059 | struct iv *iv; | |
87c476a2 | 2060 | bitmap_iterator bi; |
8b11a64c | 2061 | |
87c476a2 | 2062 | EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi) |
8b11a64c ZD |
2063 | { |
2064 | iv = ver_info (data, i)->iv; | |
2065 | if (iv && iv->biv_p && !zero_p (iv->step)) | |
2066 | add_old_iv_candidates (data, iv); | |
87c476a2 | 2067 | } |
8b11a64c ZD |
2068 | } |
2069 | ||
2070 | /* Adds candidates based on the value of the induction variable IV and USE. */ | |
2071 | ||
2072 | static void | |
2073 | add_iv_value_candidates (struct ivopts_data *data, | |
2074 | struct iv *iv, struct iv_use *use) | |
2075 | { | |
2076 | add_candidate (data, iv->base, iv->step, false, use); | |
2077 | ||
2078 | /* The same, but with initial value zero. */ | |
5212068f | 2079 | add_candidate (data, build_int_cst (TREE_TYPE (iv->base), 0), |
8b11a64c ZD |
2080 | iv->step, false, use); |
2081 | } | |
2082 | ||
2083 | /* Adds candidates based on the address IV and USE. */ | |
2084 | ||
2085 | static void | |
2086 | add_address_candidates (struct ivopts_data *data, | |
2087 | struct iv *iv, struct iv_use *use) | |
2088 | { | |
f5e2738c ZD |
2089 | tree base, abase; |
2090 | unsigned HOST_WIDE_INT offset; | |
8b11a64c ZD |
2091 | |
2092 | /* First, the trivial choices. */ | |
2093 | add_iv_value_candidates (data, iv, use); | |
2094 | ||
2095 | /* Second, try removing the COMPONENT_REFs. */ | |
2096 | if (TREE_CODE (iv->base) == ADDR_EXPR) | |
2097 | { | |
2098 | base = TREE_OPERAND (iv->base, 0); | |
2099 | while (TREE_CODE (base) == COMPONENT_REF | |
2100 | || (TREE_CODE (base) == ARRAY_REF | |
2101 | && TREE_CODE (TREE_OPERAND (base, 1)) == INTEGER_CST)) | |
2102 | base = TREE_OPERAND (base, 0); | |
2103 | ||
2104 | if (base != TREE_OPERAND (iv->base, 0)) | |
2105 | { | |
be35cf60 ZD |
2106 | gcc_assert (TREE_CODE (base) != ALIGN_INDIRECT_REF); |
2107 | gcc_assert (TREE_CODE (base) != MISALIGNED_INDIRECT_REF); | |
2108 | ||
2109 | if (TREE_CODE (base) == INDIRECT_REF) | |
8b11a64c ZD |
2110 | base = TREE_OPERAND (base, 0); |
2111 | else | |
2112 | base = build_addr (base); | |
2113 | add_candidate (data, base, iv->step, false, use); | |
2114 | } | |
2115 | } | |
2116 | ||
2117 | /* Third, try removing the constant offset. */ | |
2118 | abase = iv->base; | |
f5e2738c ZD |
2119 | base = strip_offset (abase, false, &offset); |
2120 | if (offset) | |
2121 | add_candidate (data, base, iv->step, false, use); | |
8b11a64c ZD |
2122 | } |
2123 | ||
2124 | /* Possibly adds pseudocandidate for replacing the final value of USE by | |
2125 | a direct computation. */ | |
2126 | ||
2127 | static void | |
2128 | add_iv_outer_candidates (struct ivopts_data *data, struct iv_use *use) | |
2129 | { | |
2130 | struct tree_niter_desc *niter; | |
8b11a64c ZD |
2131 | |
2132 | /* We must know where we exit the loop and how many times does it roll. */ | |
ca4c3169 ZD |
2133 | niter = niter_for_single_dom_exit (data); |
2134 | if (!niter | |
2135 | || !zero_p (niter->may_be_zero)) | |
8b11a64c ZD |
2136 | return; |
2137 | ||
2138 | add_candidate_1 (data, NULL, NULL, false, IP_NORMAL, use, NULL_TREE); | |
2139 | } | |
2140 | ||
2141 | /* Adds candidates based on the uses. */ | |
2142 | ||
2143 | static void | |
2144 | add_derived_ivs_candidates (struct ivopts_data *data) | |
2145 | { | |
2146 | unsigned i; | |
2147 | ||
2148 | for (i = 0; i < n_iv_uses (data); i++) | |
2149 | { | |
2150 | struct iv_use *use = iv_use (data, i); | |
2151 | ||
2152 | if (!use) | |
2153 | continue; | |
2154 | ||
2155 | switch (use->type) | |
2156 | { | |
2157 | case USE_NONLINEAR_EXPR: | |
2158 | case USE_COMPARE: | |
2159 | /* Just add the ivs based on the value of the iv used here. */ | |
2160 | add_iv_value_candidates (data, use->iv, use); | |
2161 | break; | |
2162 | ||
2163 | case USE_OUTER: | |
2164 | add_iv_value_candidates (data, use->iv, use); | |
2165 | ||
2166 | /* Additionally, add the pseudocandidate for the possibility to | |
2167 | replace the final value by a direct computation. */ | |
2168 | add_iv_outer_candidates (data, use); | |
2169 | break; | |
2170 | ||
2171 | case USE_ADDRESS: | |
2172 | add_address_candidates (data, use->iv, use); | |
2173 | break; | |
2174 | ||
2175 | default: | |
1e128c5f | 2176 | gcc_unreachable (); |
8b11a64c ZD |
2177 | } |
2178 | } | |
2179 | } | |
2180 | ||
b1b02be2 ZD |
2181 | /* Record important candidates and add them to related_cands bitmaps |
2182 | if needed. */ | |
2183 | ||
2184 | static void | |
2185 | record_important_candidates (struct ivopts_data *data) | |
2186 | { | |
2187 | unsigned i; | |
2188 | struct iv_use *use; | |
2189 | ||
2190 | for (i = 0; i < n_iv_cands (data); i++) | |
2191 | { | |
2192 | struct iv_cand *cand = iv_cand (data, i); | |
2193 | ||
2194 | if (cand->important) | |
2195 | bitmap_set_bit (data->important_candidates, i); | |
2196 | } | |
2197 | ||
2198 | data->consider_all_candidates = (n_iv_cands (data) | |
2199 | <= CONSIDER_ALL_CANDIDATES_BOUND); | |
2200 | ||
2201 | if (data->consider_all_candidates) | |
2202 | { | |
2203 | /* We will not need "related_cands" bitmaps in this case, | |
2204 | so release them to decrease peak memory consumption. */ | |
2205 | for (i = 0; i < n_iv_uses (data); i++) | |
2206 | { | |
2207 | use = iv_use (data, i); | |
8bdbfff5 | 2208 | BITMAP_FREE (use->related_cands); |
b1b02be2 ZD |
2209 | } |
2210 | } | |
2211 | else | |
2212 | { | |
2213 | /* Add important candidates to the related_cands bitmaps. */ | |
2214 | for (i = 0; i < n_iv_uses (data); i++) | |
2215 | bitmap_ior_into (iv_use (data, i)->related_cands, | |
2216 | data->important_candidates); | |
2217 | } | |
2218 | } | |
2219 | ||
8b11a64c ZD |
2220 | /* Finds the candidates for the induction variables. */ |
2221 | ||
2222 | static void | |
2223 | find_iv_candidates (struct ivopts_data *data) | |
2224 | { | |
2225 | /* Add commonly used ivs. */ | |
2226 | add_standard_iv_candidates (data); | |
2227 | ||
2228 | /* Add old induction variables. */ | |
2229 | add_old_ivs_candidates (data); | |
2230 | ||
2231 | /* Add induction variables derived from uses. */ | |
2232 | add_derived_ivs_candidates (data); | |
b1b02be2 ZD |
2233 | |
2234 | /* Record the important candidates. */ | |
2235 | record_important_candidates (data); | |
8b11a64c ZD |
2236 | } |
2237 | ||
2238 | /* Allocates the data structure mapping the (use, candidate) pairs to costs. | |
2239 | If consider_all_candidates is true, we use a two-dimensional array, otherwise | |
2240 | we allocate a simple list to every use. */ | |
2241 | ||
2242 | static void | |
2243 | alloc_use_cost_map (struct ivopts_data *data) | |
2244 | { | |
b1b02be2 | 2245 | unsigned i, size, s, j; |
8b11a64c ZD |
2246 | |
2247 | for (i = 0; i < n_iv_uses (data); i++) | |
2248 | { | |
2249 | struct iv_use *use = iv_use (data, i); | |
87c476a2 | 2250 | bitmap_iterator bi; |
8b11a64c ZD |
2251 | |
2252 | if (data->consider_all_candidates) | |
b1b02be2 | 2253 | size = n_iv_cands (data); |
8b11a64c ZD |
2254 | else |
2255 | { | |
b1b02be2 | 2256 | s = 0; |
87c476a2 ZD |
2257 | EXECUTE_IF_SET_IN_BITMAP (use->related_cands, 0, j, bi) |
2258 | { | |
b1b02be2 | 2259 | s++; |
87c476a2 | 2260 | } |
b1b02be2 ZD |
2261 | |
2262 | /* Round up to the power of two, so that moduling by it is fast. */ | |
2263 | for (size = 1; size < s; size <<= 1) | |
2264 | continue; | |
8b11a64c ZD |
2265 | } |
2266 | ||
b1b02be2 | 2267 | use->n_map_members = size; |
8b11a64c ZD |
2268 | use->cost_map = xcalloc (size, sizeof (struct cost_pair)); |
2269 | } | |
2270 | } | |
2271 | ||
2272 | /* Sets cost of (USE, CANDIDATE) pair to COST and record that it depends | |
2273 | on invariants DEPENDS_ON. */ | |
2274 | ||
2275 | static void | |
2276 | set_use_iv_cost (struct ivopts_data *data, | |
2277 | struct iv_use *use, struct iv_cand *cand, unsigned cost, | |
2278 | bitmap depends_on) | |
2279 | { | |
b1b02be2 ZD |
2280 | unsigned i, s; |
2281 | ||
2282 | if (cost == INFTY) | |
8b11a64c | 2283 | { |
8bdbfff5 | 2284 | BITMAP_FREE (depends_on); |
b1b02be2 | 2285 | return; |
8b11a64c ZD |
2286 | } |
2287 | ||
2288 | if (data->consider_all_candidates) | |
2289 | { | |
2290 | use->cost_map[cand->id].cand = cand; | |
2291 | use->cost_map[cand->id].cost = cost; | |
2292 | use->cost_map[cand->id].depends_on = depends_on; | |
2293 | return; | |
2294 | } | |
2295 | ||
b1b02be2 ZD |
2296 | /* n_map_members is a power of two, so this computes modulo. */ |
2297 | s = cand->id & (use->n_map_members - 1); | |
2298 | for (i = s; i < use->n_map_members; i++) | |
2299 | if (!use->cost_map[i].cand) | |
2300 | goto found; | |
2301 | for (i = 0; i < s; i++) | |
2302 | if (!use->cost_map[i].cand) | |
2303 | goto found; | |
2304 | ||
2305 | gcc_unreachable (); | |
8b11a64c | 2306 | |
b1b02be2 ZD |
2307 | found: |
2308 | use->cost_map[i].cand = cand; | |
2309 | use->cost_map[i].cost = cost; | |
2310 | use->cost_map[i].depends_on = depends_on; | |
8b11a64c ZD |
2311 | } |
2312 | ||
b1b02be2 | 2313 | /* Gets cost of (USE, CANDIDATE) pair. */ |
8b11a64c | 2314 | |
b1b02be2 ZD |
2315 | static struct cost_pair * |
2316 | get_use_iv_cost (struct ivopts_data *data, struct iv_use *use, | |
2317 | struct iv_cand *cand) | |
8b11a64c | 2318 | { |
b1b02be2 ZD |
2319 | unsigned i, s; |
2320 | struct cost_pair *ret; | |
8b11a64c ZD |
2321 | |
2322 | if (!cand) | |
b1b02be2 | 2323 | return NULL; |
8b11a64c ZD |
2324 | |
2325 | if (data->consider_all_candidates) | |
8b11a64c | 2326 | { |
b1b02be2 ZD |
2327 | ret = use->cost_map + cand->id; |
2328 | if (!ret->cand) | |
2329 | return NULL; | |
8b11a64c | 2330 | |
b1b02be2 | 2331 | return ret; |
8b11a64c | 2332 | } |
b1b02be2 ZD |
2333 | |
2334 | /* n_map_members is a power of two, so this computes modulo. */ | |
2335 | s = cand->id & (use->n_map_members - 1); | |
2336 | for (i = s; i < use->n_map_members; i++) | |
2337 | if (use->cost_map[i].cand == cand) | |
2338 | return use->cost_map + i; | |
8b11a64c | 2339 | |
b1b02be2 ZD |
2340 | for (i = 0; i < s; i++) |
2341 | if (use->cost_map[i].cand == cand) | |
2342 | return use->cost_map + i; | |
2343 | ||
2344 | return NULL; | |
8b11a64c ZD |
2345 | } |
2346 | ||
2347 | /* Returns estimate on cost of computing SEQ. */ | |
2348 | ||
2349 | static unsigned | |
2350 | seq_cost (rtx seq) | |
2351 | { | |
2352 | unsigned cost = 0; | |
2353 | rtx set; | |
2354 | ||
2355 | for (; seq; seq = NEXT_INSN (seq)) | |
2356 | { | |
2357 | set = single_set (seq); | |
2358 | if (set) | |
2359 | cost += rtx_cost (set, SET); | |
2360 | else | |
2361 | cost++; | |
2362 | } | |
2363 | ||
2364 | return cost; | |
2365 | } | |
2366 | ||
8679c649 JH |
2367 | /* Produce DECL_RTL for object obj so it looks like it is stored in memory. */ |
2368 | static rtx | |
2369 | produce_memory_decl_rtl (tree obj, int *regno) | |
2370 | { | |
2371 | rtx x; | |
e16acfcd NS |
2372 | |
2373 | gcc_assert (obj); | |
8679c649 JH |
2374 | if (TREE_STATIC (obj) || DECL_EXTERNAL (obj)) |
2375 | { | |
2376 | const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (obj)); | |
2377 | x = gen_rtx_SYMBOL_REF (Pmode, name); | |
2378 | } | |
2379 | else | |
2380 | x = gen_raw_REG (Pmode, (*regno)++); | |
2381 | ||
2382 | return gen_rtx_MEM (DECL_MODE (obj), x); | |
2383 | } | |
2384 | ||
8b11a64c ZD |
2385 | /* Prepares decl_rtl for variables referred in *EXPR_P. Callback for |
2386 | walk_tree. DATA contains the actual fake register number. */ | |
2387 | ||
2388 | static tree | |
2389 | prepare_decl_rtl (tree *expr_p, int *ws, void *data) | |
2390 | { | |
2391 | tree obj = NULL_TREE; | |
2392 | rtx x = NULL_RTX; | |
2393 | int *regno = data; | |
2394 | ||
2395 | switch (TREE_CODE (*expr_p)) | |
2396 | { | |
8679c649 JH |
2397 | case ADDR_EXPR: |
2398 | for (expr_p = &TREE_OPERAND (*expr_p, 0); | |
afe84921 RH |
2399 | handled_component_p (*expr_p); |
2400 | expr_p = &TREE_OPERAND (*expr_p, 0)) | |
2401 | continue; | |
8679c649 JH |
2402 | obj = *expr_p; |
2403 | if (DECL_P (obj)) | |
2404 | x = produce_memory_decl_rtl (obj, regno); | |
2405 | break; | |
2406 | ||
8b11a64c ZD |
2407 | case SSA_NAME: |
2408 | *ws = 0; | |
2409 | obj = SSA_NAME_VAR (*expr_p); | |
2410 | if (!DECL_RTL_SET_P (obj)) | |
2411 | x = gen_raw_REG (DECL_MODE (obj), (*regno)++); | |
2412 | break; | |
2413 | ||
2414 | case VAR_DECL: | |
2415 | case PARM_DECL: | |
2416 | case RESULT_DECL: | |
2417 | *ws = 0; | |
2418 | obj = *expr_p; | |
2419 | ||
2420 | if (DECL_RTL_SET_P (obj)) | |
2421 | break; | |
2422 | ||
2423 | if (DECL_MODE (obj) == BLKmode) | |
8679c649 | 2424 | x = produce_memory_decl_rtl (obj, regno); |
8b11a64c ZD |
2425 | else |
2426 | x = gen_raw_REG (DECL_MODE (obj), (*regno)++); | |
2427 | ||
2428 | break; | |
2429 | ||
2430 | default: | |
2431 | break; | |
2432 | } | |
2433 | ||
2434 | if (x) | |
2435 | { | |
2436 | VARRAY_PUSH_GENERIC_PTR_NOGC (decl_rtl_to_reset, obj); | |
2437 | SET_DECL_RTL (obj, x); | |
2438 | } | |
2439 | ||
2440 | return NULL_TREE; | |
2441 | } | |
2442 | ||
2443 | /* Determines cost of the computation of EXPR. */ | |
2444 | ||
2445 | static unsigned | |
2446 | computation_cost (tree expr) | |
2447 | { | |
2448 | rtx seq, rslt; | |
2449 | tree type = TREE_TYPE (expr); | |
2450 | unsigned cost; | |
1d27fed4 DD |
2451 | /* Avoid using hard regs in ways which may be unsupported. */ |
2452 | int regno = LAST_VIRTUAL_REGISTER + 1; | |
8b11a64c ZD |
2453 | |
2454 | walk_tree (&expr, prepare_decl_rtl, ®no, NULL); | |
2455 | start_sequence (); | |
2456 | rslt = expand_expr (expr, NULL_RTX, TYPE_MODE (type), EXPAND_NORMAL); | |
2457 | seq = get_insns (); | |
2458 | end_sequence (); | |
2459 | ||
2460 | cost = seq_cost (seq); | |
2461 | if (GET_CODE (rslt) == MEM) | |
2462 | cost += address_cost (XEXP (rslt, 0), TYPE_MODE (type)); | |
2463 | ||
2464 | return cost; | |
2465 | } | |
2466 | ||
2467 | /* Returns variable containing the value of candidate CAND at statement AT. */ | |
2468 | ||
2469 | static tree | |
2470 | var_at_stmt (struct loop *loop, struct iv_cand *cand, tree stmt) | |
2471 | { | |
2472 | if (stmt_after_increment (loop, cand, stmt)) | |
2473 | return cand->var_after; | |
2474 | else | |
2475 | return cand->var_before; | |
2476 | } | |
2477 | ||
2478 | /* Determines the expression by that USE is expressed from induction variable | |
2479 | CAND at statement AT in LOOP. */ | |
2480 | ||
2481 | static tree | |
2482 | get_computation_at (struct loop *loop, | |
2483 | struct iv_use *use, struct iv_cand *cand, tree at) | |
2484 | { | |
2f4675b4 ZD |
2485 | tree ubase = use->iv->base; |
2486 | tree ustep = use->iv->step; | |
2487 | tree cbase = cand->iv->base; | |
2488 | tree cstep = cand->iv->step; | |
8b11a64c ZD |
2489 | tree utype = TREE_TYPE (ubase), ctype = TREE_TYPE (cbase); |
2490 | tree uutype; | |
2491 | tree expr, delta; | |
2492 | tree ratio; | |
2493 | unsigned HOST_WIDE_INT ustepi, cstepi; | |
2494 | HOST_WIDE_INT ratioi; | |
2495 | ||
2496 | if (TYPE_PRECISION (utype) > TYPE_PRECISION (ctype)) | |
2497 | { | |
2498 | /* We do not have a precision to express the values of use. */ | |
2499 | return NULL_TREE; | |
2500 | } | |
2501 | ||
2502 | expr = var_at_stmt (loop, cand, at); | |
2503 | ||
2504 | if (TREE_TYPE (expr) != ctype) | |
2505 | { | |
2506 | /* This may happen with the original ivs. */ | |
2507 | expr = fold_convert (ctype, expr); | |
2508 | } | |
2509 | ||
2510 | if (TYPE_UNSIGNED (utype)) | |
2511 | uutype = utype; | |
2512 | else | |
2513 | { | |
2514 | uutype = unsigned_type_for (utype); | |
2515 | ubase = fold_convert (uutype, ubase); | |
2516 | ustep = fold_convert (uutype, ustep); | |
2517 | } | |
2518 | ||
2519 | if (uutype != ctype) | |
2520 | { | |
2521 | expr = fold_convert (uutype, expr); | |
2522 | cbase = fold_convert (uutype, cbase); | |
2523 | cstep = fold_convert (uutype, cstep); | |
2524 | } | |
2525 | ||
2526 | if (!cst_and_fits_in_hwi (cstep) | |
2527 | || !cst_and_fits_in_hwi (ustep)) | |
2528 | return NULL_TREE; | |
2529 | ||
2530 | ustepi = int_cst_value (ustep); | |
2531 | cstepi = int_cst_value (cstep); | |
2532 | ||
2533 | if (!divide (TYPE_PRECISION (uutype), ustepi, cstepi, &ratioi)) | |
2534 | { | |
2535 | /* TODO maybe consider case when ustep divides cstep and the ratio is | |
2536 | a power of 2 (so that the division is fast to execute)? We would | |
2537 | need to be much more careful with overflows etc. then. */ | |
2538 | return NULL_TREE; | |
2539 | } | |
2540 | ||
2541 | /* We may need to shift the value if we are after the increment. */ | |
2542 | if (stmt_after_increment (loop, cand, at)) | |
2543 | cbase = fold (build2 (PLUS_EXPR, uutype, cbase, cstep)); | |
2544 | ||
b0a168b6 ZD |
2545 | /* use = ubase - ratio * cbase + ratio * var. |
2546 | ||
2547 | In general case ubase + ratio * (var - cbase) could be better (one less | |
2548 | multiplication), but often it is possible to eliminate redundant parts | |
2549 | of computations from (ubase - ratio * cbase) term, and if it does not | |
2550 | happen, fold is able to apply the distributive law to obtain this form | |
2551 | anyway. */ | |
8b11a64c ZD |
2552 | |
2553 | if (ratioi == 1) | |
2554 | { | |
2555 | delta = fold (build2 (MINUS_EXPR, uutype, ubase, cbase)); | |
2556 | expr = fold (build2 (PLUS_EXPR, uutype, expr, delta)); | |
2557 | } | |
2558 | else if (ratioi == -1) | |
2559 | { | |
2560 | delta = fold (build2 (PLUS_EXPR, uutype, ubase, cbase)); | |
2561 | expr = fold (build2 (MINUS_EXPR, uutype, delta, expr)); | |
2562 | } | |
b0a168b6 | 2563 | else |
8b11a64c ZD |
2564 | { |
2565 | ratio = build_int_cst_type (uutype, ratioi); | |
2566 | delta = fold (build2 (MULT_EXPR, uutype, ratio, cbase)); | |
2567 | delta = fold (build2 (MINUS_EXPR, uutype, ubase, delta)); | |
2568 | expr = fold (build2 (MULT_EXPR, uutype, ratio, expr)); | |
2569 | expr = fold (build2 (PLUS_EXPR, uutype, delta, expr)); | |
2570 | } | |
8b11a64c ZD |
2571 | |
2572 | return fold_convert (utype, expr); | |
2573 | } | |
2574 | ||
2575 | /* Determines the expression by that USE is expressed from induction variable | |
2576 | CAND in LOOP. */ | |
2577 | ||
2578 | static tree | |
2579 | get_computation (struct loop *loop, struct iv_use *use, struct iv_cand *cand) | |
2580 | { | |
2581 | return get_computation_at (loop, use, cand, use->stmt); | |
2582 | } | |
2583 | ||
8b11a64c ZD |
2584 | /* Returns cost of addition in MODE. */ |
2585 | ||
2586 | static unsigned | |
2587 | add_cost (enum machine_mode mode) | |
2588 | { | |
2589 | static unsigned costs[NUM_MACHINE_MODES]; | |
2590 | rtx seq; | |
2591 | unsigned cost; | |
2592 | ||
2593 | if (costs[mode]) | |
2594 | return costs[mode]; | |
2595 | ||
2596 | start_sequence (); | |
2597 | force_operand (gen_rtx_fmt_ee (PLUS, mode, | |
2598 | gen_raw_REG (mode, FIRST_PSEUDO_REGISTER), | |
2599 | gen_raw_REG (mode, FIRST_PSEUDO_REGISTER + 1)), | |
2600 | NULL_RTX); | |
2601 | seq = get_insns (); | |
2602 | end_sequence (); | |
2603 | ||
2604 | cost = seq_cost (seq); | |
2605 | if (!cost) | |
2606 | cost = 1; | |
2607 | ||
2608 | costs[mode] = cost; | |
2609 | ||
2610 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2611 | fprintf (dump_file, "Addition in %s costs %d\n", | |
2612 | GET_MODE_NAME (mode), cost); | |
2613 | return cost; | |
2614 | } | |
2615 | ||
2616 | /* Entry in a hashtable of already known costs for multiplication. */ | |
2617 | struct mbc_entry | |
2618 | { | |
2619 | HOST_WIDE_INT cst; /* The constant to multiply by. */ | |
2620 | enum machine_mode mode; /* In mode. */ | |
2621 | unsigned cost; /* The cost. */ | |
2622 | }; | |
2623 | ||
2624 | /* Counts hash value for the ENTRY. */ | |
2625 | ||
2626 | static hashval_t | |
2627 | mbc_entry_hash (const void *entry) | |
2628 | { | |
2629 | const struct mbc_entry *e = entry; | |
2630 | ||
2631 | return 57 * (hashval_t) e->mode + (hashval_t) (e->cst % 877); | |
2632 | } | |
2633 | ||
2634 | /* Compares the hash table entries ENTRY1 and ENTRY2. */ | |
2635 | ||
2636 | static int | |
2637 | mbc_entry_eq (const void *entry1, const void *entry2) | |
2638 | { | |
2639 | const struct mbc_entry *e1 = entry1; | |
2640 | const struct mbc_entry *e2 = entry2; | |
2641 | ||
2642 | return (e1->mode == e2->mode | |
2643 | && e1->cst == e2->cst); | |
2644 | } | |
2645 | ||
2646 | /* Returns cost of multiplication by constant CST in MODE. */ | |
2647 | ||
2648 | static unsigned | |
2649 | multiply_by_cost (HOST_WIDE_INT cst, enum machine_mode mode) | |
2650 | { | |
2651 | static htab_t costs; | |
2652 | struct mbc_entry **cached, act; | |
2653 | rtx seq; | |
2654 | unsigned cost; | |
2655 | ||
2656 | if (!costs) | |
2657 | costs = htab_create (100, mbc_entry_hash, mbc_entry_eq, free); | |
2658 | ||
2659 | act.mode = mode; | |
2660 | act.cst = cst; | |
2661 | cached = (struct mbc_entry **) htab_find_slot (costs, &act, INSERT); | |
2662 | if (*cached) | |
2663 | return (*cached)->cost; | |
2664 | ||
2665 | *cached = xmalloc (sizeof (struct mbc_entry)); | |
2666 | (*cached)->mode = mode; | |
2667 | (*cached)->cst = cst; | |
2668 | ||
2669 | start_sequence (); | |
2670 | expand_mult (mode, gen_raw_REG (mode, FIRST_PSEUDO_REGISTER), GEN_INT (cst), | |
2671 | NULL_RTX, 0); | |
2672 | seq = get_insns (); | |
2673 | end_sequence (); | |
2674 | ||
2675 | cost = seq_cost (seq); | |
2676 | ||
2677 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2678 | fprintf (dump_file, "Multiplication by %d in %s costs %d\n", | |
2679 | (int) cst, GET_MODE_NAME (mode), cost); | |
2680 | ||
2681 | (*cached)->cost = cost; | |
2682 | ||
2683 | return cost; | |
2684 | } | |
2685 | ||
2686 | /* Returns cost of address in shape symbol + var + OFFSET + RATIO * index. | |
2687 | If SYMBOL_PRESENT is false, symbol is omitted. If VAR_PRESENT is false, | |
2688 | variable is omitted. The created memory accesses MODE. | |
2689 | ||
2690 | TODO -- there must be some better way. This all is quite crude. */ | |
2691 | ||
2692 | static unsigned | |
2693 | get_address_cost (bool symbol_present, bool var_present, | |
2694 | unsigned HOST_WIDE_INT offset, HOST_WIDE_INT ratio) | |
2695 | { | |
2696 | #define MAX_RATIO 128 | |
2697 | static sbitmap valid_mult; | |
2698 | static HOST_WIDE_INT rat, off; | |
2699 | static HOST_WIDE_INT min_offset, max_offset; | |
2700 | static unsigned costs[2][2][2][2]; | |
2701 | unsigned cost, acost; | |
2702 | rtx seq, addr, base; | |
2703 | bool offset_p, ratio_p; | |
2704 | rtx reg1; | |
2705 | HOST_WIDE_INT s_offset; | |
2706 | unsigned HOST_WIDE_INT mask; | |
2707 | unsigned bits; | |
2708 | ||
2709 | if (!valid_mult) | |
2710 | { | |
2711 | HOST_WIDE_INT i; | |
2712 | ||
2713 | reg1 = gen_raw_REG (Pmode, FIRST_PSEUDO_REGISTER); | |
2714 | ||
2715 | addr = gen_rtx_fmt_ee (PLUS, Pmode, reg1, NULL_RTX); | |
2716 | for (i = 1; i <= 1 << 20; i <<= 1) | |
2717 | { | |
2718 | XEXP (addr, 1) = GEN_INT (i); | |
2719 | if (!memory_address_p (Pmode, addr)) | |
2720 | break; | |
2721 | } | |
2722 | max_offset = i >> 1; | |
2723 | off = max_offset; | |
2724 | ||
2725 | for (i = 1; i <= 1 << 20; i <<= 1) | |
2726 | { | |
2727 | XEXP (addr, 1) = GEN_INT (-i); | |
2728 | if (!memory_address_p (Pmode, addr)) | |
2729 | break; | |
2730 | } | |
2731 | min_offset = -(i >> 1); | |
2732 | ||
2733 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2734 | { | |
2735 | fprintf (dump_file, "get_address_cost:\n"); | |
2736 | fprintf (dump_file, " min offset %d\n", (int) min_offset); | |
2737 | fprintf (dump_file, " max offset %d\n", (int) max_offset); | |
2738 | } | |
2739 | ||
2740 | valid_mult = sbitmap_alloc (2 * MAX_RATIO + 1); | |
2741 | sbitmap_zero (valid_mult); | |
2742 | rat = 1; | |
2743 | addr = gen_rtx_fmt_ee (MULT, Pmode, reg1, NULL_RTX); | |
2744 | for (i = -MAX_RATIO; i <= MAX_RATIO; i++) | |
2745 | { | |
2746 | XEXP (addr, 1) = GEN_INT (i); | |
2747 | if (memory_address_p (Pmode, addr)) | |
2748 | { | |
2749 | SET_BIT (valid_mult, i + MAX_RATIO); | |
2750 | rat = i; | |
2751 | } | |
2752 | } | |
2753 | ||
2754 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2755 | { | |
2756 | fprintf (dump_file, " allowed multipliers:"); | |
2757 | for (i = -MAX_RATIO; i <= MAX_RATIO; i++) | |
2758 | if (TEST_BIT (valid_mult, i + MAX_RATIO)) | |
2759 | fprintf (dump_file, " %d", (int) i); | |
2760 | fprintf (dump_file, "\n"); | |
2761 | fprintf (dump_file, "\n"); | |
2762 | } | |
2763 | } | |
2764 | ||
2765 | bits = GET_MODE_BITSIZE (Pmode); | |
2766 | mask = ~(~(unsigned HOST_WIDE_INT) 0 << (bits - 1) << 1); | |
2767 | offset &= mask; | |
2768 | if ((offset >> (bits - 1) & 1)) | |
2769 | offset |= ~mask; | |
2770 | s_offset = offset; | |
2771 | ||
2772 | cost = 0; | |
a85a9024 UW |
2773 | offset_p = (s_offset != 0 |
2774 | && min_offset <= s_offset && s_offset <= max_offset); | |
8b11a64c ZD |
2775 | ratio_p = (ratio != 1 |
2776 | && -MAX_RATIO <= ratio && ratio <= MAX_RATIO | |
2777 | && TEST_BIT (valid_mult, ratio + MAX_RATIO)); | |
2778 | ||
2779 | if (ratio != 1 && !ratio_p) | |
2780 | cost += multiply_by_cost (ratio, Pmode); | |
2781 | ||
2782 | if (s_offset && !offset_p && !symbol_present) | |
2783 | { | |
2784 | cost += add_cost (Pmode); | |
2785 | var_present = true; | |
2786 | } | |
2787 | ||
2788 | acost = costs[symbol_present][var_present][offset_p][ratio_p]; | |
2789 | if (!acost) | |
2790 | { | |
2791 | acost = 0; | |
2792 | ||
2793 | addr = gen_raw_REG (Pmode, FIRST_PSEUDO_REGISTER); | |
2794 | reg1 = gen_raw_REG (Pmode, FIRST_PSEUDO_REGISTER + 1); | |
2795 | if (ratio_p) | |
2796 | addr = gen_rtx_fmt_ee (MULT, Pmode, addr, GEN_INT (rat)); | |
2797 | ||
a85a9024 | 2798 | if (var_present) |
7299dbfb | 2799 | addr = gen_rtx_fmt_ee (PLUS, Pmode, addr, reg1); |
a85a9024 | 2800 | |
8b11a64c ZD |
2801 | if (symbol_present) |
2802 | { | |
2803 | base = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup ("")); | |
2804 | if (offset_p) | |
2805 | base = gen_rtx_fmt_e (CONST, Pmode, | |
2806 | gen_rtx_fmt_ee (PLUS, Pmode, | |
2807 | base, | |
2808 | GEN_INT (off))); | |
8b11a64c ZD |
2809 | } |
2810 | else if (offset_p) | |
2811 | base = GEN_INT (off); | |
2812 | else | |
2813 | base = NULL_RTX; | |
2814 | ||
2815 | if (base) | |
7299dbfb | 2816 | addr = gen_rtx_fmt_ee (PLUS, Pmode, addr, base); |
8b11a64c ZD |
2817 | |
2818 | start_sequence (); | |
2819 | addr = memory_address (Pmode, addr); | |
2820 | seq = get_insns (); | |
2821 | end_sequence (); | |
2822 | ||
2823 | acost = seq_cost (seq); | |
2824 | acost += address_cost (addr, Pmode); | |
2825 | ||
2826 | if (!acost) | |
2827 | acost = 1; | |
2828 | costs[symbol_present][var_present][offset_p][ratio_p] = acost; | |
2829 | } | |
2830 | ||
2831 | return cost + acost; | |
2832 | } | |
2833 | ||
2834 | /* Records invariants in *EXPR_P. Callback for walk_tree. DATA contains | |
2835 | the bitmap to that we should store it. */ | |
2836 | ||
2837 | static struct ivopts_data *fd_ivopts_data; | |
2838 | static tree | |
2839 | find_depends (tree *expr_p, int *ws ATTRIBUTE_UNUSED, void *data) | |
2840 | { | |
2841 | bitmap *depends_on = data; | |
2842 | struct version_info *info; | |
2843 | ||
2844 | if (TREE_CODE (*expr_p) != SSA_NAME) | |
2845 | return NULL_TREE; | |
2846 | info = name_info (fd_ivopts_data, *expr_p); | |
2847 | ||
2848 | if (!info->inv_id || info->has_nonlin_use) | |
2849 | return NULL_TREE; | |
2850 | ||
2851 | if (!*depends_on) | |
8bdbfff5 | 2852 | *depends_on = BITMAP_ALLOC (NULL); |
8b11a64c ZD |
2853 | bitmap_set_bit (*depends_on, info->inv_id); |
2854 | ||
2855 | return NULL_TREE; | |
2856 | } | |
2857 | ||
7299dbfb | 2858 | /* Estimates cost of forcing EXPR into a variable. DEPENDS_ON is a set of the |
8b11a64c ZD |
2859 | invariants the computation depends on. */ |
2860 | ||
2861 | static unsigned | |
2862 | force_var_cost (struct ivopts_data *data, | |
2863 | tree expr, bitmap *depends_on) | |
2864 | { | |
2865 | static bool costs_initialized = false; | |
2866 | static unsigned integer_cost; | |
2867 | static unsigned symbol_cost; | |
2868 | static unsigned address_cost; | |
7299dbfb ZD |
2869 | tree op0, op1; |
2870 | unsigned cost0, cost1, cost; | |
2871 | enum machine_mode mode; | |
8b11a64c ZD |
2872 | |
2873 | if (!costs_initialized) | |
2874 | { | |
2875 | tree var = create_tmp_var_raw (integer_type_node, "test_var"); | |
2876 | rtx x = gen_rtx_MEM (DECL_MODE (var), | |
2877 | gen_rtx_SYMBOL_REF (Pmode, "test_var")); | |
2878 | tree addr; | |
2879 | tree type = build_pointer_type (integer_type_node); | |
2880 | ||
2881 | integer_cost = computation_cost (build_int_cst_type (integer_type_node, | |
2882 | 2000)); | |
2883 | ||
2884 | SET_DECL_RTL (var, x); | |
2885 | TREE_STATIC (var) = 1; | |
2886 | addr = build1 (ADDR_EXPR, type, var); | |
2887 | symbol_cost = computation_cost (addr) + 1; | |
2888 | ||
2889 | address_cost | |
2890 | = computation_cost (build2 (PLUS_EXPR, type, | |
2891 | addr, | |
2892 | build_int_cst_type (type, 2000))) + 1; | |
2893 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2894 | { | |
2895 | fprintf (dump_file, "force_var_cost:\n"); | |
2896 | fprintf (dump_file, " integer %d\n", (int) integer_cost); | |
2897 | fprintf (dump_file, " symbol %d\n", (int) symbol_cost); | |
2898 | fprintf (dump_file, " address %d\n", (int) address_cost); | |
2899 | fprintf (dump_file, " other %d\n", (int) target_spill_cost); | |
2900 | fprintf (dump_file, "\n"); | |
2901 | } | |
2902 | ||
2903 | costs_initialized = true; | |
2904 | } | |
2905 | ||
f5e2738c ZD |
2906 | STRIP_NOPS (expr); |
2907 | ||
8b11a64c ZD |
2908 | if (depends_on) |
2909 | { | |
2910 | fd_ivopts_data = data; | |
2911 | walk_tree (&expr, find_depends, depends_on, NULL); | |
2912 | } | |
2913 | ||
2914 | if (SSA_VAR_P (expr)) | |
2915 | return 0; | |
2916 | ||
2917 | if (TREE_INVARIANT (expr)) | |
2918 | { | |
2919 | if (TREE_CODE (expr) == INTEGER_CST) | |
2920 | return integer_cost; | |
2921 | ||
2922 | if (TREE_CODE (expr) == ADDR_EXPR) | |
2923 | { | |
2924 | tree obj = TREE_OPERAND (expr, 0); | |
2925 | ||
2926 | if (TREE_CODE (obj) == VAR_DECL | |
2927 | || TREE_CODE (obj) == PARM_DECL | |
2928 | || TREE_CODE (obj) == RESULT_DECL) | |
2929 | return symbol_cost; | |
2930 | } | |
2931 | ||
2932 | return address_cost; | |
2933 | } | |
2934 | ||
7299dbfb ZD |
2935 | switch (TREE_CODE (expr)) |
2936 | { | |
2937 | case PLUS_EXPR: | |
2938 | case MINUS_EXPR: | |
2939 | case MULT_EXPR: | |
2940 | op0 = TREE_OPERAND (expr, 0); | |
2941 | op1 = TREE_OPERAND (expr, 1); | |
f5e2738c ZD |
2942 | STRIP_NOPS (op0); |
2943 | STRIP_NOPS (op1); | |
7299dbfb ZD |
2944 | |
2945 | if (is_gimple_val (op0)) | |
2946 | cost0 = 0; | |
2947 | else | |
2948 | cost0 = force_var_cost (data, op0, NULL); | |
2949 | ||
2950 | if (is_gimple_val (op1)) | |
2951 | cost1 = 0; | |
2952 | else | |
2953 | cost1 = force_var_cost (data, op1, NULL); | |
2954 | ||
2955 | break; | |
2956 | ||
2957 | default: | |
2958 | /* Just an arbitrary value, FIXME. */ | |
2959 | return target_spill_cost; | |
2960 | } | |
2961 | ||
2962 | mode = TYPE_MODE (TREE_TYPE (expr)); | |
2963 | switch (TREE_CODE (expr)) | |
2964 | { | |
2965 | case PLUS_EXPR: | |
2966 | case MINUS_EXPR: | |
2967 | cost = add_cost (mode); | |
2968 | break; | |
2969 | ||
2970 | case MULT_EXPR: | |
2971 | if (cst_and_fits_in_hwi (op0)) | |
2972 | cost = multiply_by_cost (int_cst_value (op0), mode); | |
2973 | else if (cst_and_fits_in_hwi (op1)) | |
2974 | cost = multiply_by_cost (int_cst_value (op1), mode); | |
2975 | else | |
2976 | return target_spill_cost; | |
2977 | break; | |
2978 | ||
2979 | default: | |
2980 | gcc_unreachable (); | |
2981 | } | |
2982 | ||
2983 | cost += cost0; | |
2984 | cost += cost1; | |
2985 | ||
2986 | /* Bound the cost by target_spill_cost. The parts of complicated | |
2987 | computations often are either loop invariant or at least can | |
2988 | be shared between several iv uses, so letting this grow without | |
2989 | limits would not give reasonable results. */ | |
2990 | return cost < target_spill_cost ? cost : target_spill_cost; | |
8b11a64c ZD |
2991 | } |
2992 | ||
8b11a64c ZD |
2993 | /* Estimates cost of expressing address ADDR as var + symbol + offset. The |
2994 | value of offset is added to OFFSET, SYMBOL_PRESENT and VAR_PRESENT are set | |
2995 | to false if the corresponding part is missing. DEPENDS_ON is a set of the | |
2996 | invariants the computation depends on. */ | |
2997 | ||
2998 | static unsigned | |
2999 | split_address_cost (struct ivopts_data *data, | |
3000 | tree addr, bool *symbol_present, bool *var_present, | |
3001 | unsigned HOST_WIDE_INT *offset, bitmap *depends_on) | |
3002 | { | |
2f4675b4 ZD |
3003 | tree core; |
3004 | HOST_WIDE_INT bitsize; | |
3005 | HOST_WIDE_INT bitpos; | |
3006 | tree toffset; | |
3007 | enum machine_mode mode; | |
3008 | int unsignedp, volatilep; | |
3009 | ||
3010 | core = get_inner_reference (addr, &bitsize, &bitpos, &toffset, &mode, | |
2614034e | 3011 | &unsignedp, &volatilep, false); |
8b11a64c | 3012 | |
2f4675b4 ZD |
3013 | if (toffset != 0 |
3014 | || bitpos % BITS_PER_UNIT != 0 | |
3015 | || TREE_CODE (core) != VAR_DECL) | |
8b11a64c ZD |
3016 | { |
3017 | *symbol_present = false; | |
3018 | *var_present = true; | |
3019 | fd_ivopts_data = data; | |
3020 | walk_tree (&addr, find_depends, depends_on, NULL); | |
3021 | return target_spill_cost; | |
2f4675b4 ZD |
3022 | } |
3023 | ||
3024 | *offset += bitpos / BITS_PER_UNIT; | |
8b11a64c ZD |
3025 | if (TREE_STATIC (core) |
3026 | || DECL_EXTERNAL (core)) | |
3027 | { | |
3028 | *symbol_present = true; | |
3029 | *var_present = false; | |
3030 | return 0; | |
3031 | } | |
3032 | ||
3033 | *symbol_present = false; | |
3034 | *var_present = true; | |
3035 | return 0; | |
3036 | } | |
3037 | ||
3038 | /* Estimates cost of expressing difference of addresses E1 - E2 as | |
3039 | var + symbol + offset. The value of offset is added to OFFSET, | |
3040 | SYMBOL_PRESENT and VAR_PRESENT are set to false if the corresponding | |
3041 | part is missing. DEPENDS_ON is a set of the invariants the computation | |
3042 | depends on. */ | |
3043 | ||
3044 | static unsigned | |
3045 | ptr_difference_cost (struct ivopts_data *data, | |
3046 | tree e1, tree e2, bool *symbol_present, bool *var_present, | |
3047 | unsigned HOST_WIDE_INT *offset, bitmap *depends_on) | |
3048 | { | |
2f4675b4 | 3049 | HOST_WIDE_INT diff = 0; |
8b11a64c ZD |
3050 | unsigned cost; |
3051 | ||
1e128c5f | 3052 | gcc_assert (TREE_CODE (e1) == ADDR_EXPR); |
8b11a64c | 3053 | |
7299dbfb | 3054 | if (ptr_difference_const (e1, e2, &diff)) |
8b11a64c ZD |
3055 | { |
3056 | *offset += diff; | |
3057 | *symbol_present = false; | |
3058 | *var_present = false; | |
3059 | return 0; | |
3060 | } | |
3061 | ||
3062 | if (e2 == integer_zero_node) | |
3063 | return split_address_cost (data, TREE_OPERAND (e1, 0), | |
3064 | symbol_present, var_present, offset, depends_on); | |
3065 | ||
3066 | *symbol_present = false; | |
3067 | *var_present = true; | |
3068 | ||
3069 | cost = force_var_cost (data, e1, depends_on); | |
3070 | cost += force_var_cost (data, e2, depends_on); | |
3071 | cost += add_cost (Pmode); | |
3072 | ||
3073 | return cost; | |
3074 | } | |
3075 | ||
3076 | /* Estimates cost of expressing difference E1 - E2 as | |
3077 | var + symbol + offset. The value of offset is added to OFFSET, | |
3078 | SYMBOL_PRESENT and VAR_PRESENT are set to false if the corresponding | |
3079 | part is missing. DEPENDS_ON is a set of the invariants the computation | |
3080 | depends on. */ | |
3081 | ||
3082 | static unsigned | |
3083 | difference_cost (struct ivopts_data *data, | |
3084 | tree e1, tree e2, bool *symbol_present, bool *var_present, | |
3085 | unsigned HOST_WIDE_INT *offset, bitmap *depends_on) | |
3086 | { | |
3087 | unsigned cost; | |
3088 | enum machine_mode mode = TYPE_MODE (TREE_TYPE (e1)); | |
f5e2738c ZD |
3089 | unsigned HOST_WIDE_INT off1, off2; |
3090 | ||
3091 | e1 = strip_offset (e1, false, &off1); | |
3092 | e2 = strip_offset (e2, false, &off2); | |
3093 | *offset += off1 - off2; | |
8b11a64c | 3094 | |
f5e2738c ZD |
3095 | STRIP_NOPS (e1); |
3096 | STRIP_NOPS (e2); | |
8b11a64c ZD |
3097 | |
3098 | if (TREE_CODE (e1) == ADDR_EXPR) | |
3099 | return ptr_difference_cost (data, e1, e2, symbol_present, var_present, offset, | |
3100 | depends_on); | |
3101 | *symbol_present = false; | |
3102 | ||
3103 | if (operand_equal_p (e1, e2, 0)) | |
3104 | { | |
3105 | *var_present = false; | |
3106 | return 0; | |
3107 | } | |
3108 | *var_present = true; | |
3109 | if (zero_p (e2)) | |
3110 | return force_var_cost (data, e1, depends_on); | |
3111 | ||
3112 | if (zero_p (e1)) | |
3113 | { | |
3114 | cost = force_var_cost (data, e2, depends_on); | |
3115 | cost += multiply_by_cost (-1, mode); | |
3116 | ||
3117 | return cost; | |
3118 | } | |
3119 | ||
3120 | cost = force_var_cost (data, e1, depends_on); | |
3121 | cost += force_var_cost (data, e2, depends_on); | |
3122 | cost += add_cost (mode); | |
3123 | ||
3124 | return cost; | |
3125 | } | |
3126 | ||
3127 | /* Determines the cost of the computation by that USE is expressed | |
3128 | from induction variable CAND. If ADDRESS_P is true, we just need | |
3129 | to create an address from it, otherwise we want to get it into | |
3130 | register. A set of invariants we depend on is stored in | |
3131 | DEPENDS_ON. AT is the statement at that the value is computed. */ | |
3132 | ||
3133 | static unsigned | |
3134 | get_computation_cost_at (struct ivopts_data *data, | |
3135 | struct iv_use *use, struct iv_cand *cand, | |
3136 | bool address_p, bitmap *depends_on, tree at) | |
3137 | { | |
3138 | tree ubase = use->iv->base, ustep = use->iv->step; | |
3139 | tree cbase, cstep; | |
3140 | tree utype = TREE_TYPE (ubase), ctype; | |
3141 | unsigned HOST_WIDE_INT ustepi, cstepi, offset = 0; | |
3142 | HOST_WIDE_INT ratio, aratio; | |
3143 | bool var_present, symbol_present; | |
3144 | unsigned cost = 0, n_sums; | |
3145 | ||
3146 | *depends_on = NULL; | |
3147 | ||
3148 | /* Only consider real candidates. */ | |
3149 | if (!cand->iv) | |
3150 | return INFTY; | |
3151 | ||
3152 | cbase = cand->iv->base; | |
3153 | cstep = cand->iv->step; | |
3154 | ctype = TREE_TYPE (cbase); | |
3155 | ||
3156 | if (TYPE_PRECISION (utype) > TYPE_PRECISION (ctype)) | |
3157 | { | |
3158 | /* We do not have a precision to express the values of use. */ | |
3159 | return INFTY; | |
3160 | } | |
3161 | ||
e6845c23 ZD |
3162 | if (address_p) |
3163 | { | |
3164 | /* Do not try to express address of an object with computation based | |
3165 | on address of a different object. This may cause problems in rtl | |
3166 | level alias analysis (that does not expect this to be happening, | |
3167 | as this is illegal in C), and would be unlikely to be useful | |
3168 | anyway. */ | |
3169 | if (use->iv->base_object | |
3170 | && cand->iv->base_object | |
3171 | && !operand_equal_p (use->iv->base_object, cand->iv->base_object, 0)) | |
3172 | return INFTY; | |
3173 | } | |
3174 | ||
8b11a64c ZD |
3175 | if (!cst_and_fits_in_hwi (ustep) |
3176 | || !cst_and_fits_in_hwi (cstep)) | |
3177 | return INFTY; | |
3178 | ||
3179 | if (TREE_CODE (ubase) == INTEGER_CST | |
3180 | && !cst_and_fits_in_hwi (ubase)) | |
3181 | goto fallback; | |
3182 | ||
3183 | if (TREE_CODE (cbase) == INTEGER_CST | |
3184 | && !cst_and_fits_in_hwi (cbase)) | |
3185 | goto fallback; | |
3186 | ||
3187 | ustepi = int_cst_value (ustep); | |
3188 | cstepi = int_cst_value (cstep); | |
3189 | ||
3190 | if (TYPE_PRECISION (utype) != TYPE_PRECISION (ctype)) | |
3191 | { | |
3192 | /* TODO -- add direct handling of this case. */ | |
3193 | goto fallback; | |
3194 | } | |
3195 | ||
3196 | if (!divide (TYPE_PRECISION (utype), ustepi, cstepi, &ratio)) | |
3197 | return INFTY; | |
3198 | ||
3199 | /* use = ubase + ratio * (var - cbase). If either cbase is a constant | |
3200 | or ratio == 1, it is better to handle this like | |
3201 | ||
3202 | ubase - ratio * cbase + ratio * var | |
3203 | ||
3204 | (also holds in the case ratio == -1, TODO. */ | |
3205 | ||
3206 | if (TREE_CODE (cbase) == INTEGER_CST) | |
3207 | { | |
3208 | offset = - ratio * int_cst_value (cbase); | |
3209 | cost += difference_cost (data, | |
3210 | ubase, integer_zero_node, | |
3211 | &symbol_present, &var_present, &offset, | |
3212 | depends_on); | |
3213 | } | |
3214 | else if (ratio == 1) | |
3215 | { | |
3216 | cost += difference_cost (data, | |
3217 | ubase, cbase, | |
3218 | &symbol_present, &var_present, &offset, | |
3219 | depends_on); | |
3220 | } | |
3221 | else | |
3222 | { | |
3223 | cost += force_var_cost (data, cbase, depends_on); | |
3224 | cost += add_cost (TYPE_MODE (ctype)); | |
3225 | cost += difference_cost (data, | |
3226 | ubase, integer_zero_node, | |
3227 | &symbol_present, &var_present, &offset, | |
3228 | depends_on); | |
3229 | } | |
3230 | ||
3231 | /* If we are after the increment, the value of the candidate is higher by | |
3232 | one iteration. */ | |
3233 | if (stmt_after_increment (data->current_loop, cand, at)) | |
3234 | offset -= ratio * cstepi; | |
3235 | ||
3236 | /* Now the computation is in shape symbol + var1 + const + ratio * var2. | |
3237 | (symbol/var/const parts may be omitted). If we are looking for an address, | |
3238 | find the cost of addressing this. */ | |
3239 | if (address_p) | |
7299dbfb | 3240 | return cost + get_address_cost (symbol_present, var_present, offset, ratio); |
8b11a64c ZD |
3241 | |
3242 | /* Otherwise estimate the costs for computing the expression. */ | |
3243 | aratio = ratio > 0 ? ratio : -ratio; | |
3244 | if (!symbol_present && !var_present && !offset) | |
3245 | { | |
3246 | if (ratio != 1) | |
3247 | cost += multiply_by_cost (ratio, TYPE_MODE (ctype)); | |
3248 | ||
3249 | return cost; | |
3250 | } | |
3251 | ||
3252 | if (aratio != 1) | |
3253 | cost += multiply_by_cost (aratio, TYPE_MODE (ctype)); | |
3254 | ||
3255 | n_sums = 1; | |
3256 | if (var_present | |
3257 | /* Symbol + offset should be compile-time computable. */ | |
3258 | && (symbol_present || offset)) | |
3259 | n_sums++; | |
3260 | ||
3261 | return cost + n_sums * add_cost (TYPE_MODE (ctype)); | |
3262 | ||
3263 | fallback: | |
3264 | { | |
3265 | /* Just get the expression, expand it and measure the cost. */ | |
3266 | tree comp = get_computation_at (data->current_loop, use, cand, at); | |
3267 | ||
3268 | if (!comp) | |
3269 | return INFTY; | |
3270 | ||
3271 | if (address_p) | |
3272 | comp = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (comp)), comp); | |
3273 | ||
3274 | return computation_cost (comp); | |
3275 | } | |
3276 | } | |
3277 | ||
3278 | /* Determines the cost of the computation by that USE is expressed | |
3279 | from induction variable CAND. If ADDRESS_P is true, we just need | |
3280 | to create an address from it, otherwise we want to get it into | |
3281 | register. A set of invariants we depend on is stored in | |
3282 | DEPENDS_ON. */ | |
3283 | ||
3284 | static unsigned | |
3285 | get_computation_cost (struct ivopts_data *data, | |
3286 | struct iv_use *use, struct iv_cand *cand, | |
3287 | bool address_p, bitmap *depends_on) | |
3288 | { | |
3289 | return get_computation_cost_at (data, | |
3290 | use, cand, address_p, depends_on, use->stmt); | |
3291 | } | |
3292 | ||
3293 | /* Determines cost of basing replacement of USE on CAND in a generic | |
3294 | expression. */ | |
3295 | ||
b1b02be2 | 3296 | static bool |
8b11a64c ZD |
3297 | determine_use_iv_cost_generic (struct ivopts_data *data, |
3298 | struct iv_use *use, struct iv_cand *cand) | |
3299 | { | |
3300 | bitmap depends_on; | |
eec5fec9 ZD |
3301 | unsigned cost; |
3302 | ||
3303 | /* The simple case first -- if we need to express value of the preserved | |
3304 | original biv, the cost is 0. This also prevents us from counting the | |
3305 | cost of increment twice -- once at this use and once in the cost of | |
3306 | the candidate. */ | |
3307 | if (cand->pos == IP_ORIGINAL | |
3308 | && cand->incremented_at == use->stmt) | |
3309 | { | |
3310 | set_use_iv_cost (data, use, cand, 0, NULL); | |
3311 | return true; | |
3312 | } | |
8b11a64c | 3313 | |
eec5fec9 | 3314 | cost = get_computation_cost (data, use, cand, false, &depends_on); |
8b11a64c | 3315 | set_use_iv_cost (data, use, cand, cost, depends_on); |
b1b02be2 ZD |
3316 | |
3317 | return cost != INFTY; | |
8b11a64c ZD |
3318 | } |
3319 | ||
3320 | /* Determines cost of basing replacement of USE on CAND in an address. */ | |
3321 | ||
b1b02be2 | 3322 | static bool |
8b11a64c ZD |
3323 | determine_use_iv_cost_address (struct ivopts_data *data, |
3324 | struct iv_use *use, struct iv_cand *cand) | |
3325 | { | |
3326 | bitmap depends_on; | |
3327 | unsigned cost = get_computation_cost (data, use, cand, true, &depends_on); | |
3328 | ||
3329 | set_use_iv_cost (data, use, cand, cost, depends_on); | |
b1b02be2 ZD |
3330 | |
3331 | return cost != INFTY; | |
8b11a64c ZD |
3332 | } |
3333 | ||
3334 | /* Computes value of induction variable IV in iteration NITER. */ | |
3335 | ||
3336 | static tree | |
3337 | iv_value (struct iv *iv, tree niter) | |
3338 | { | |
3339 | tree val; | |
3340 | tree type = TREE_TYPE (iv->base); | |
3341 | ||
3342 | niter = fold_convert (type, niter); | |
2f4675b4 | 3343 | val = fold (build2 (MULT_EXPR, type, iv->step, niter)); |
8b11a64c ZD |
3344 | |
3345 | return fold (build2 (PLUS_EXPR, type, iv->base, val)); | |
3346 | } | |
3347 | ||
3348 | /* Computes value of candidate CAND at position AT in iteration NITER. */ | |
3349 | ||
3350 | static tree | |
3351 | cand_value_at (struct loop *loop, struct iv_cand *cand, tree at, tree niter) | |
3352 | { | |
3353 | tree val = iv_value (cand->iv, niter); | |
3354 | tree type = TREE_TYPE (cand->iv->base); | |
3355 | ||
3356 | if (stmt_after_increment (loop, cand, at)) | |
3357 | val = fold (build2 (PLUS_EXPR, type, val, cand->iv->step)); | |
3358 | ||
3359 | return val; | |
3360 | } | |
3361 | ||
ca4c3169 ZD |
3362 | /* Returns period of induction variable iv. */ |
3363 | ||
3364 | static tree | |
3365 | iv_period (struct iv *iv) | |
3366 | { | |
3367 | tree step = iv->step, period, type; | |
3368 | tree pow2div; | |
3369 | ||
3370 | gcc_assert (step && TREE_CODE (step) == INTEGER_CST); | |
3371 | ||
3372 | /* Period of the iv is gcd (step, type range). Since type range is power | |
3373 | of two, it suffices to determine the maximum power of two that divides | |
3374 | step. */ | |
3375 | pow2div = num_ending_zeros (step); | |
3376 | type = unsigned_type_for (TREE_TYPE (step)); | |
3377 | ||
3378 | period = build_low_bits_mask (type, | |
3379 | (TYPE_PRECISION (type) | |
3380 | - tree_low_cst (pow2div, 1))); | |
3381 | ||
3382 | return period; | |
3383 | } | |
3384 | ||
8b11a64c ZD |
3385 | /* Check whether it is possible to express the condition in USE by comparison |
3386 | of candidate CAND. If so, store the comparison code to COMPARE and the | |
3387 | value compared with to BOUND. */ | |
3388 | ||
3389 | static bool | |
ca4c3169 | 3390 | may_eliminate_iv (struct ivopts_data *data, |
8b11a64c ZD |
3391 | struct iv_use *use, struct iv_cand *cand, |
3392 | enum tree_code *compare, tree *bound) | |
3393 | { | |
e6845c23 | 3394 | basic_block ex_bb; |
8b11a64c | 3395 | edge exit; |
ca4c3169 ZD |
3396 | struct tree_niter_desc *niter; |
3397 | tree nit, nit_type; | |
3398 | tree wider_type, period, per_type; | |
3399 | struct loop *loop = data->current_loop; | |
e6845c23 ZD |
3400 | |
3401 | /* For now works only for exits that dominate the loop latch. TODO -- extend | |
3402 | for other conditions inside loop body. */ | |
3403 | ex_bb = bb_for_stmt (use->stmt); | |
3404 | if (use->stmt != last_stmt (ex_bb) | |
3405 | || TREE_CODE (use->stmt) != COND_EXPR) | |
8b11a64c | 3406 | return false; |
e6845c23 | 3407 | if (!dominated_by_p (CDI_DOMINATORS, loop->latch, ex_bb)) |
8b11a64c ZD |
3408 | return false; |
3409 | ||
e6845c23 ZD |
3410 | exit = EDGE_SUCC (ex_bb, 0); |
3411 | if (flow_bb_inside_loop_p (loop, exit->dest)) | |
3412 | exit = EDGE_SUCC (ex_bb, 1); | |
3413 | if (flow_bb_inside_loop_p (loop, exit->dest)) | |
3414 | return false; | |
3415 | ||
ca4c3169 ZD |
3416 | niter = niter_for_exit (data, exit); |
3417 | if (!niter | |
3418 | || !zero_p (niter->may_be_zero)) | |
8b11a64c ZD |
3419 | return false; |
3420 | ||
ca4c3169 ZD |
3421 | nit = niter->niter; |
3422 | nit_type = TREE_TYPE (nit); | |
8b11a64c | 3423 | |
ca4c3169 ZD |
3424 | /* Determine whether we may use the variable to test whether niter iterations |
3425 | elapsed. This is the case iff the period of the induction variable is | |
3426 | greater than the number of iterations. */ | |
3427 | period = iv_period (cand->iv); | |
3428 | if (!period) | |
8b11a64c | 3429 | return false; |
ca4c3169 ZD |
3430 | per_type = TREE_TYPE (period); |
3431 | ||
3432 | wider_type = TREE_TYPE (period); | |
3433 | if (TYPE_PRECISION (nit_type) < TYPE_PRECISION (per_type)) | |
3434 | wider_type = per_type; | |
3435 | else | |
3436 | wider_type = nit_type; | |
8b11a64c | 3437 | |
ca4c3169 ZD |
3438 | if (!integer_nonzerop (fold (build2 (GE_EXPR, boolean_type_node, |
3439 | fold_convert (wider_type, period), | |
3440 | fold_convert (wider_type, nit))))) | |
8b11a64c ZD |
3441 | return false; |
3442 | ||
ca4c3169 ZD |
3443 | if (exit->flags & EDGE_TRUE_VALUE) |
3444 | *compare = EQ_EXPR; | |
3445 | else | |
3446 | *compare = NE_EXPR; | |
3447 | ||
3448 | *bound = cand_value_at (loop, cand, use->stmt, nit); | |
8b11a64c ZD |
3449 | return true; |
3450 | } | |
3451 | ||
3452 | /* Determines cost of basing replacement of USE on CAND in a condition. */ | |
3453 | ||
b1b02be2 | 3454 | static bool |
8b11a64c ZD |
3455 | determine_use_iv_cost_condition (struct ivopts_data *data, |
3456 | struct iv_use *use, struct iv_cand *cand) | |
3457 | { | |
3458 | tree bound; | |
3459 | enum tree_code compare; | |
3460 | ||
3461 | /* Only consider real candidates. */ | |
3462 | if (!cand->iv) | |
3463 | { | |
3464 | set_use_iv_cost (data, use, cand, INFTY, NULL); | |
b1b02be2 | 3465 | return false; |
8b11a64c ZD |
3466 | } |
3467 | ||
ca4c3169 | 3468 | if (may_eliminate_iv (data, use, cand, &compare, &bound)) |
8b11a64c ZD |
3469 | { |
3470 | bitmap depends_on = NULL; | |
3471 | unsigned cost = force_var_cost (data, bound, &depends_on); | |
3472 | ||
3473 | set_use_iv_cost (data, use, cand, cost, depends_on); | |
b1b02be2 | 3474 | return cost != INFTY; |
8b11a64c ZD |
3475 | } |
3476 | ||
3477 | /* The induction variable elimination failed; just express the original | |
3478 | giv. If it is compared with an invariant, note that we cannot get | |
3479 | rid of it. */ | |
3480 | if (TREE_CODE (*use->op_p) == SSA_NAME) | |
3481 | record_invariant (data, *use->op_p, true); | |
3482 | else | |
3483 | { | |
3484 | record_invariant (data, TREE_OPERAND (*use->op_p, 0), true); | |
3485 | record_invariant (data, TREE_OPERAND (*use->op_p, 1), true); | |
3486 | } | |
3487 | ||
b1b02be2 | 3488 | return determine_use_iv_cost_generic (data, use, cand); |
8b11a64c ZD |
3489 | } |
3490 | ||
3491 | /* Checks whether it is possible to replace the final value of USE by | |
3492 | a direct computation. If so, the formula is stored to *VALUE. */ | |
3493 | ||
3494 | static bool | |
ca4c3169 ZD |
3495 | may_replace_final_value (struct ivopts_data *data, struct iv_use *use, |
3496 | tree *value) | |
8b11a64c | 3497 | { |
ca4c3169 | 3498 | struct loop *loop = data->current_loop; |
8b11a64c ZD |
3499 | edge exit; |
3500 | struct tree_niter_desc *niter; | |
3501 | ||
3502 | exit = single_dom_exit (loop); | |
3503 | if (!exit) | |
3504 | return false; | |
3505 | ||
1e128c5f GB |
3506 | gcc_assert (dominated_by_p (CDI_DOMINATORS, exit->src, |
3507 | bb_for_stmt (use->stmt))); | |
8b11a64c | 3508 | |
ca4c3169 ZD |
3509 | niter = niter_for_single_dom_exit (data); |
3510 | if (!niter | |
3511 | || !zero_p (niter->may_be_zero)) | |
8b11a64c ZD |
3512 | return false; |
3513 | ||
3514 | *value = iv_value (use->iv, niter->niter); | |
3515 | ||
3516 | return true; | |
3517 | } | |
3518 | ||
3519 | /* Determines cost of replacing final value of USE using CAND. */ | |
3520 | ||
b1b02be2 | 3521 | static bool |
8b11a64c ZD |
3522 | determine_use_iv_cost_outer (struct ivopts_data *data, |
3523 | struct iv_use *use, struct iv_cand *cand) | |
3524 | { | |
3525 | bitmap depends_on; | |
3526 | unsigned cost; | |
3527 | edge exit; | |
3528 | tree value; | |
3529 | struct loop *loop = data->current_loop; | |
eec5fec9 ZD |
3530 | |
3531 | /* The simple case first -- if we need to express value of the preserved | |
3532 | original biv, the cost is 0. This also prevents us from counting the | |
3533 | cost of increment twice -- once at this use and once in the cost of | |
3534 | the candidate. */ | |
3535 | if (cand->pos == IP_ORIGINAL | |
3536 | && cand->incremented_at == use->stmt) | |
3537 | { | |
3538 | set_use_iv_cost (data, use, cand, 0, NULL); | |
3539 | return true; | |
3540 | } | |
3541 | ||
8b11a64c ZD |
3542 | if (!cand->iv) |
3543 | { | |
ca4c3169 | 3544 | if (!may_replace_final_value (data, use, &value)) |
8b11a64c ZD |
3545 | { |
3546 | set_use_iv_cost (data, use, cand, INFTY, NULL); | |
b1b02be2 | 3547 | return false; |
8b11a64c ZD |
3548 | } |
3549 | ||
3550 | depends_on = NULL; | |
3551 | cost = force_var_cost (data, value, &depends_on); | |
3552 | ||
3553 | cost /= AVG_LOOP_NITER (loop); | |
3554 | ||
3555 | set_use_iv_cost (data, use, cand, cost, depends_on); | |
b1b02be2 | 3556 | return cost != INFTY; |
8b11a64c ZD |
3557 | } |
3558 | ||
3559 | exit = single_dom_exit (loop); | |
3560 | if (exit) | |
3561 | { | |
3562 | /* If there is just a single exit, we may use value of the candidate | |
3563 | after we take it to determine the value of use. */ | |
3564 | cost = get_computation_cost_at (data, use, cand, false, &depends_on, | |
3565 | last_stmt (exit->src)); | |
3566 | if (cost != INFTY) | |
3567 | cost /= AVG_LOOP_NITER (loop); | |
3568 | } | |
3569 | else | |
3570 | { | |
3571 | /* Otherwise we just need to compute the iv. */ | |
3572 | cost = get_computation_cost (data, use, cand, false, &depends_on); | |
3573 | } | |
3574 | ||
3575 | set_use_iv_cost (data, use, cand, cost, depends_on); | |
b1b02be2 ZD |
3576 | |
3577 | return cost != INFTY; | |
8b11a64c ZD |
3578 | } |
3579 | ||
b1b02be2 ZD |
3580 | /* Determines cost of basing replacement of USE on CAND. Returns false |
3581 | if USE cannot be based on CAND. */ | |
8b11a64c | 3582 | |
b1b02be2 | 3583 | static bool |
8b11a64c ZD |
3584 | determine_use_iv_cost (struct ivopts_data *data, |
3585 | struct iv_use *use, struct iv_cand *cand) | |
3586 | { | |
3587 | switch (use->type) | |
3588 | { | |
3589 | case USE_NONLINEAR_EXPR: | |
b1b02be2 | 3590 | return determine_use_iv_cost_generic (data, use, cand); |
8b11a64c ZD |
3591 | |
3592 | case USE_OUTER: | |
b1b02be2 | 3593 | return determine_use_iv_cost_outer (data, use, cand); |
8b11a64c ZD |
3594 | |
3595 | case USE_ADDRESS: | |
b1b02be2 | 3596 | return determine_use_iv_cost_address (data, use, cand); |
8b11a64c ZD |
3597 | |
3598 | case USE_COMPARE: | |
b1b02be2 | 3599 | return determine_use_iv_cost_condition (data, use, cand); |
8b11a64c ZD |
3600 | |
3601 | default: | |
1e128c5f | 3602 | gcc_unreachable (); |
8b11a64c ZD |
3603 | } |
3604 | } | |
3605 | ||
3606 | /* Determines costs of basing the use of the iv on an iv candidate. */ | |
3607 | ||
3608 | static void | |
3609 | determine_use_iv_costs (struct ivopts_data *data) | |
3610 | { | |
3611 | unsigned i, j; | |
3612 | struct iv_use *use; | |
3613 | struct iv_cand *cand; | |
8bdbfff5 | 3614 | bitmap to_clear = BITMAP_ALLOC (NULL); |
8b11a64c ZD |
3615 | |
3616 | alloc_use_cost_map (data); | |
3617 | ||
8b11a64c ZD |
3618 | for (i = 0; i < n_iv_uses (data); i++) |
3619 | { | |
3620 | use = iv_use (data, i); | |
3621 | ||
3622 | if (data->consider_all_candidates) | |
3623 | { | |
3624 | for (j = 0; j < n_iv_cands (data); j++) | |
3625 | { | |
3626 | cand = iv_cand (data, j); | |
3627 | determine_use_iv_cost (data, use, cand); | |
3628 | } | |
3629 | } | |
3630 | else | |
3631 | { | |
87c476a2 ZD |
3632 | bitmap_iterator bi; |
3633 | ||
3634 | EXECUTE_IF_SET_IN_BITMAP (use->related_cands, 0, j, bi) | |
8b11a64c ZD |
3635 | { |
3636 | cand = iv_cand (data, j); | |
b1b02be2 ZD |
3637 | if (!determine_use_iv_cost (data, use, cand)) |
3638 | bitmap_set_bit (to_clear, j); | |
87c476a2 | 3639 | } |
b1b02be2 ZD |
3640 | |
3641 | /* Remove the candidates for that the cost is infinite from | |
3642 | the list of related candidates. */ | |
3643 | bitmap_and_compl_into (use->related_cands, to_clear); | |
3644 | bitmap_clear (to_clear); | |
8b11a64c ZD |
3645 | } |
3646 | } | |
3647 | ||
8bdbfff5 | 3648 | BITMAP_FREE (to_clear); |
b1b02be2 | 3649 | |
8b11a64c ZD |
3650 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3651 | { | |
3652 | fprintf (dump_file, "Use-candidate costs:\n"); | |
3653 | ||
3654 | for (i = 0; i < n_iv_uses (data); i++) | |
3655 | { | |
3656 | use = iv_use (data, i); | |
3657 | ||
3658 | fprintf (dump_file, "Use %d:\n", i); | |
3659 | fprintf (dump_file, " cand\tcost\tdepends on\n"); | |
3660 | for (j = 0; j < use->n_map_members; j++) | |
3661 | { | |
3662 | if (!use->cost_map[j].cand | |
3663 | || use->cost_map[j].cost == INFTY) | |
3664 | continue; | |
3665 | ||
3666 | fprintf (dump_file, " %d\t%d\t", | |
3667 | use->cost_map[j].cand->id, | |
3668 | use->cost_map[j].cost); | |
3669 | if (use->cost_map[j].depends_on) | |
3670 | bitmap_print (dump_file, | |
3671 | use->cost_map[j].depends_on, "",""); | |
3672 | fprintf (dump_file, "\n"); | |
3673 | } | |
3674 | ||
3675 | fprintf (dump_file, "\n"); | |
3676 | } | |
3677 | fprintf (dump_file, "\n"); | |
3678 | } | |
3679 | } | |
3680 | ||
3681 | /* Determines cost of the candidate CAND. */ | |
3682 | ||
3683 | static void | |
3684 | determine_iv_cost (struct ivopts_data *data, struct iv_cand *cand) | |
3685 | { | |
3686 | unsigned cost_base, cost_step; | |
4366cf6d | 3687 | tree base; |
8b11a64c ZD |
3688 | |
3689 | if (!cand->iv) | |
3690 | { | |
3691 | cand->cost = 0; | |
3692 | return; | |
3693 | } | |
3694 | ||
3695 | /* There are two costs associated with the candidate -- its increment | |
3696 | and its initialization. The second is almost negligible for any loop | |
3697 | that rolls enough, so we take it just very little into account. */ | |
3698 | ||
3699 | base = cand->iv->base; | |
3700 | cost_base = force_var_cost (data, base, NULL); | |
3701 | cost_step = add_cost (TYPE_MODE (TREE_TYPE (base))); | |
3702 | ||
3703 | cand->cost = cost_step + cost_base / AVG_LOOP_NITER (current_loop); | |
3704 | ||
cf5d1802 ZD |
3705 | /* Prefer the original iv unless we may gain something by replacing it; |
3706 | this is not really relevant for artificial ivs created by other | |
3707 | passes. */ | |
3708 | if (cand->pos == IP_ORIGINAL | |
3709 | && !DECL_ARTIFICIAL (SSA_NAME_VAR (cand->var_before))) | |
8b11a64c ZD |
3710 | cand->cost--; |
3711 | ||
3712 | /* Prefer not to insert statements into latch unless there are some | |
3713 | already (so that we do not create unnecessary jumps). */ | |
4366cf6d ZD |
3714 | if (cand->pos == IP_END |
3715 | && empty_block_p (ip_end_pos (data->current_loop))) | |
3716 | cand->cost++; | |
8b11a64c ZD |
3717 | } |
3718 | ||
3719 | /* Determines costs of computation of the candidates. */ | |
3720 | ||
3721 | static void | |
3722 | determine_iv_costs (struct ivopts_data *data) | |
3723 | { | |
3724 | unsigned i; | |
3725 | ||
3726 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3727 | { | |
3728 | fprintf (dump_file, "Candidate costs:\n"); | |
3729 | fprintf (dump_file, " cand\tcost\n"); | |
3730 | } | |
3731 | ||
3732 | for (i = 0; i < n_iv_cands (data); i++) | |
3733 | { | |
3734 | struct iv_cand *cand = iv_cand (data, i); | |
3735 | ||
3736 | determine_iv_cost (data, cand); | |
3737 | ||
3738 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3739 | fprintf (dump_file, " %d\t%d\n", i, cand->cost); | |
3740 | } | |
3741 | ||
3742 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3743 | fprintf (dump_file, "\n"); | |
3744 | } | |
3745 | ||
3746 | /* Calculates cost for having SIZE induction variables. */ | |
3747 | ||
3748 | static unsigned | |
3749 | ivopts_global_cost_for_size (struct ivopts_data *data, unsigned size) | |
3750 | { | |
3751 | return global_cost_for_size (size, | |
3752 | loop_data (data->current_loop)->regs_used, | |
3753 | n_iv_uses (data)); | |
3754 | } | |
3755 | ||
3756 | /* For each size of the induction variable set determine the penalty. */ | |
3757 | ||
3758 | static void | |
3759 | determine_set_costs (struct ivopts_data *data) | |
3760 | { | |
3761 | unsigned j, n; | |
3762 | tree phi, op; | |
3763 | struct loop *loop = data->current_loop; | |
87c476a2 | 3764 | bitmap_iterator bi; |
8b11a64c ZD |
3765 | |
3766 | /* We use the following model (definitely improvable, especially the | |
3767 | cost function -- TODO): | |
3768 | ||
3769 | We estimate the number of registers available (using MD data), name it A. | |
3770 | ||
3771 | We estimate the number of registers used by the loop, name it U. This | |
3772 | number is obtained as the number of loop phi nodes (not counting virtual | |
3773 | registers and bivs) + the number of variables from outside of the loop. | |
3774 | ||
3775 | We set a reserve R (free regs that are used for temporary computations, | |
3776 | etc.). For now the reserve is a constant 3. | |
3777 | ||
3778 | Let I be the number of induction variables. | |
3779 | ||
3780 | -- if U + I + R <= A, the cost is I * SMALL_COST (just not to encourage | |
3781 | make a lot of ivs without a reason). | |
3782 | -- if A - R < U + I <= A, the cost is I * PRES_COST | |
3783 | -- if U + I > A, the cost is I * PRES_COST and | |
3784 | number of uses * SPILL_COST * (U + I - A) / (U + I) is added. */ | |
3785 | ||
3786 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3787 | { | |
3788 | fprintf (dump_file, "Global costs:\n"); | |
3789 | fprintf (dump_file, " target_avail_regs %d\n", target_avail_regs); | |
3790 | fprintf (dump_file, " target_small_cost %d\n", target_small_cost); | |
3791 | fprintf (dump_file, " target_pres_cost %d\n", target_pres_cost); | |
3792 | fprintf (dump_file, " target_spill_cost %d\n", target_spill_cost); | |
3793 | } | |
3794 | ||
3795 | n = 0; | |
bb29d951 | 3796 | for (phi = phi_nodes (loop->header); phi; phi = PHI_CHAIN (phi)) |
8b11a64c ZD |
3797 | { |
3798 | op = PHI_RESULT (phi); | |
3799 | ||
3800 | if (!is_gimple_reg (op)) | |
3801 | continue; | |
3802 | ||
3803 | if (get_iv (data, op)) | |
3804 | continue; | |
3805 | ||
3806 | n++; | |
3807 | } | |
3808 | ||
87c476a2 | 3809 | EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, j, bi) |
8b11a64c ZD |
3810 | { |
3811 | struct version_info *info = ver_info (data, j); | |
3812 | ||
3813 | if (info->inv_id && info->has_nonlin_use) | |
3814 | n++; | |
87c476a2 | 3815 | } |
8b11a64c ZD |
3816 | |
3817 | loop_data (loop)->regs_used = n; | |
3818 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3819 | fprintf (dump_file, " regs_used %d\n", n); | |
3820 | ||
3821 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3822 | { | |
3823 | fprintf (dump_file, " cost for size:\n"); | |
3824 | fprintf (dump_file, " ivs\tcost\n"); | |
3825 | for (j = 0; j <= 2 * target_avail_regs; j++) | |
3826 | fprintf (dump_file, " %d\t%d\n", j, | |
3827 | ivopts_global_cost_for_size (data, j)); | |
3828 | fprintf (dump_file, "\n"); | |
3829 | } | |
3830 | } | |
3831 | ||
b1b02be2 | 3832 | /* Returns true if A is a cheaper cost pair than B. */ |
8b11a64c | 3833 | |
b1b02be2 ZD |
3834 | static bool |
3835 | cheaper_cost_pair (struct cost_pair *a, struct cost_pair *b) | |
8b11a64c | 3836 | { |
b1b02be2 ZD |
3837 | if (!a) |
3838 | return false; | |
8b11a64c | 3839 | |
b1b02be2 ZD |
3840 | if (!b) |
3841 | return true; | |
3842 | ||
3843 | if (a->cost < b->cost) | |
3844 | return true; | |
3845 | ||
3846 | if (a->cost > b->cost) | |
3847 | return false; | |
3848 | ||
3849 | /* In case the costs are the same, prefer the cheaper candidate. */ | |
3850 | if (a->cand->cost < b->cand->cost) | |
3851 | return true; | |
3852 | ||
3853 | return false; | |
3854 | } | |
3855 | ||
3856 | /* Computes the cost field of IVS structure. */ | |
3857 | ||
3858 | static void | |
3859 | iv_ca_recount_cost (struct ivopts_data *data, struct iv_ca *ivs) | |
3860 | { | |
3861 | unsigned cost = 0; | |
3862 | ||
3863 | cost += ivs->cand_use_cost; | |
3864 | cost += ivs->cand_cost; | |
3865 | cost += ivopts_global_cost_for_size (data, ivs->n_regs); | |
3866 | ||
3867 | ivs->cost = cost; | |
3868 | } | |
3869 | ||
3870 | /* Set USE not to be expressed by any candidate in IVS. */ | |
3871 | ||
3872 | static void | |
3873 | iv_ca_set_no_cp (struct ivopts_data *data, struct iv_ca *ivs, | |
3874 | struct iv_use *use) | |
3875 | { | |
3876 | unsigned uid = use->id, cid, iid; | |
3877 | bitmap deps; | |
3878 | struct cost_pair *cp; | |
3879 | bitmap_iterator bi; | |
3880 | ||
3881 | cp = ivs->cand_for_use[uid]; | |
3882 | if (!cp) | |
3883 | return; | |
3884 | cid = cp->cand->id; | |
3885 | ||
3886 | ivs->bad_uses++; | |
3887 | ivs->cand_for_use[uid] = NULL; | |
3888 | ivs->n_cand_uses[cid]--; | |
3889 | ||
3890 | if (ivs->n_cand_uses[cid] == 0) | |
8b11a64c | 3891 | { |
b1b02be2 ZD |
3892 | bitmap_clear_bit (ivs->cands, cid); |
3893 | /* Do not count the pseudocandidates. */ | |
3894 | if (cp->cand->iv) | |
3895 | ivs->n_regs--; | |
36f5ada1 | 3896 | ivs->n_cands--; |
b1b02be2 ZD |
3897 | ivs->cand_cost -= cp->cand->cost; |
3898 | } | |
3899 | ||
3900 | ivs->cand_use_cost -= cp->cost; | |
3901 | ||
3902 | deps = cp->depends_on; | |
80cad5fa | 3903 | |
b1b02be2 ZD |
3904 | if (deps) |
3905 | { | |
3906 | EXECUTE_IF_SET_IN_BITMAP (deps, 0, iid, bi) | |
3907 | { | |
3908 | ivs->n_invariant_uses[iid]--; | |
3909 | if (ivs->n_invariant_uses[iid] == 0) | |
3910 | ivs->n_regs--; | |
3911 | } | |
8b11a64c ZD |
3912 | } |
3913 | ||
b1b02be2 ZD |
3914 | iv_ca_recount_cost (data, ivs); |
3915 | } | |
3916 | ||
3917 | /* Set cost pair for USE in set IVS to CP. */ | |
3918 | ||
3919 | static void | |
3920 | iv_ca_set_cp (struct ivopts_data *data, struct iv_ca *ivs, | |
3921 | struct iv_use *use, struct cost_pair *cp) | |
3922 | { | |
3923 | unsigned uid = use->id, cid, iid; | |
3924 | bitmap deps; | |
3925 | bitmap_iterator bi; | |
3926 | ||
3927 | if (ivs->cand_for_use[uid] == cp) | |
3928 | return; | |
3929 | ||
3930 | if (ivs->cand_for_use[uid]) | |
3931 | iv_ca_set_no_cp (data, ivs, use); | |
3932 | ||
3933 | if (cp) | |
8b11a64c | 3934 | { |
b1b02be2 | 3935 | cid = cp->cand->id; |
8b11a64c | 3936 | |
b1b02be2 ZD |
3937 | ivs->bad_uses--; |
3938 | ivs->cand_for_use[uid] = cp; | |
3939 | ivs->n_cand_uses[cid]++; | |
3940 | if (ivs->n_cand_uses[cid] == 1) | |
8b11a64c | 3941 | { |
b1b02be2 ZD |
3942 | bitmap_set_bit (ivs->cands, cid); |
3943 | /* Do not count the pseudocandidates. */ | |
3944 | if (cp->cand->iv) | |
3945 | ivs->n_regs++; | |
36f5ada1 | 3946 | ivs->n_cands++; |
b1b02be2 | 3947 | ivs->cand_cost += cp->cand->cost; |
8b11a64c ZD |
3948 | } |
3949 | ||
b1b02be2 ZD |
3950 | ivs->cand_use_cost += cp->cost; |
3951 | ||
3952 | deps = cp->depends_on; | |
3953 | ||
3954 | if (deps) | |
8b11a64c | 3955 | { |
b1b02be2 | 3956 | EXECUTE_IF_SET_IN_BITMAP (deps, 0, iid, bi) |
87c476a2 | 3957 | { |
b1b02be2 ZD |
3958 | ivs->n_invariant_uses[iid]++; |
3959 | if (ivs->n_invariant_uses[iid] == 1) | |
3960 | ivs->n_regs++; | |
87c476a2 | 3961 | } |
8b11a64c ZD |
3962 | } |
3963 | ||
b1b02be2 | 3964 | iv_ca_recount_cost (data, ivs); |
87c476a2 | 3965 | } |
b1b02be2 ZD |
3966 | } |
3967 | ||
3968 | /* Extend set IVS by expressing USE by some of the candidates in it | |
3969 | if possible. */ | |
3970 | ||
3971 | static void | |
3972 | iv_ca_add_use (struct ivopts_data *data, struct iv_ca *ivs, | |
3973 | struct iv_use *use) | |
3974 | { | |
3975 | struct cost_pair *best_cp = NULL, *cp; | |
3976 | bitmap_iterator bi; | |
3977 | unsigned i; | |
8b11a64c | 3978 | |
b1b02be2 ZD |
3979 | gcc_assert (ivs->upto >= use->id); |
3980 | ||
3981 | if (ivs->upto == use->id) | |
3982 | { | |
3983 | ivs->upto++; | |
3984 | ivs->bad_uses++; | |
3985 | } | |
8b11a64c | 3986 | |
b1b02be2 ZD |
3987 | EXECUTE_IF_SET_IN_BITMAP (ivs->cands, 0, i, bi) |
3988 | { | |
3989 | cp = get_use_iv_cost (data, use, iv_cand (data, i)); | |
8b11a64c | 3990 | |
b1b02be2 ZD |
3991 | if (cheaper_cost_pair (cp, best_cp)) |
3992 | best_cp = cp; | |
3993 | } | |
8b11a64c | 3994 | |
b1b02be2 | 3995 | iv_ca_set_cp (data, ivs, use, best_cp); |
8b11a64c ZD |
3996 | } |
3997 | ||
b1b02be2 | 3998 | /* Get cost for assignment IVS. */ |
8b11a64c ZD |
3999 | |
4000 | static unsigned | |
b1b02be2 ZD |
4001 | iv_ca_cost (struct iv_ca *ivs) |
4002 | { | |
4003 | return (ivs->bad_uses ? INFTY : ivs->cost); | |
4004 | } | |
4005 | ||
4006 | /* Returns true if all dependences of CP are among invariants in IVS. */ | |
4007 | ||
4008 | static bool | |
4009 | iv_ca_has_deps (struct iv_ca *ivs, struct cost_pair *cp) | |
8b11a64c ZD |
4010 | { |
4011 | unsigned i; | |
87c476a2 | 4012 | bitmap_iterator bi; |
8b11a64c | 4013 | |
b1b02be2 ZD |
4014 | if (!cp->depends_on) |
4015 | return true; | |
4016 | ||
4017 | EXECUTE_IF_SET_IN_BITMAP (cp->depends_on, 0, i, bi) | |
8b11a64c | 4018 | { |
b1b02be2 ZD |
4019 | if (ivs->n_invariant_uses[i] == 0) |
4020 | return false; | |
4021 | } | |
4022 | ||
4023 | return true; | |
4024 | } | |
4025 | ||
4026 | /* Creates change of expressing USE by NEW_CP instead of OLD_CP and chains | |
4027 | it before NEXT_CHANGE. */ | |
4028 | ||
4029 | static struct iv_ca_delta * | |
4030 | iv_ca_delta_add (struct iv_use *use, struct cost_pair *old_cp, | |
4031 | struct cost_pair *new_cp, struct iv_ca_delta *next_change) | |
4032 | { | |
4033 | struct iv_ca_delta *change = xmalloc (sizeof (struct iv_ca_delta)); | |
4034 | ||
4035 | change->use = use; | |
4036 | change->old_cp = old_cp; | |
4037 | change->new_cp = new_cp; | |
4038 | change->next_change = next_change; | |
4039 | ||
4040 | return change; | |
4041 | } | |
4042 | ||
36f5ada1 | 4043 | /* Joins two lists of changes L1 and L2. Destructive -- old lists |
6c6cfbfd | 4044 | are rewritten. */ |
36f5ada1 ZD |
4045 | |
4046 | static struct iv_ca_delta * | |
4047 | iv_ca_delta_join (struct iv_ca_delta *l1, struct iv_ca_delta *l2) | |
4048 | { | |
4049 | struct iv_ca_delta *last; | |
4050 | ||
4051 | if (!l2) | |
4052 | return l1; | |
4053 | ||
4054 | if (!l1) | |
4055 | return l2; | |
4056 | ||
4057 | for (last = l1; last->next_change; last = last->next_change) | |
4058 | continue; | |
4059 | last->next_change = l2; | |
4060 | ||
4061 | return l1; | |
4062 | } | |
4063 | ||
b1b02be2 ZD |
4064 | /* Returns candidate by that USE is expressed in IVS. */ |
4065 | ||
4066 | static struct cost_pair * | |
4067 | iv_ca_cand_for_use (struct iv_ca *ivs, struct iv_use *use) | |
4068 | { | |
4069 | return ivs->cand_for_use[use->id]; | |
4070 | } | |
4071 | ||
36f5ada1 ZD |
4072 | /* Reverse the list of changes DELTA, forming the inverse to it. */ |
4073 | ||
4074 | static struct iv_ca_delta * | |
4075 | iv_ca_delta_reverse (struct iv_ca_delta *delta) | |
4076 | { | |
4077 | struct iv_ca_delta *act, *next, *prev = NULL; | |
4078 | struct cost_pair *tmp; | |
4079 | ||
4080 | for (act = delta; act; act = next) | |
4081 | { | |
4082 | next = act->next_change; | |
4083 | act->next_change = prev; | |
4084 | prev = act; | |
4085 | ||
4086 | tmp = act->old_cp; | |
4087 | act->old_cp = act->new_cp; | |
4088 | act->new_cp = tmp; | |
4089 | } | |
4090 | ||
4091 | return prev; | |
4092 | } | |
4093 | ||
b1b02be2 ZD |
4094 | /* Commit changes in DELTA to IVS. If FORWARD is false, the changes are |
4095 | reverted instead. */ | |
4096 | ||
4097 | static void | |
4098 | iv_ca_delta_commit (struct ivopts_data *data, struct iv_ca *ivs, | |
4099 | struct iv_ca_delta *delta, bool forward) | |
4100 | { | |
4101 | struct cost_pair *from, *to; | |
36f5ada1 | 4102 | struct iv_ca_delta *act; |
b1b02be2 | 4103 | |
36f5ada1 ZD |
4104 | if (!forward) |
4105 | delta = iv_ca_delta_reverse (delta); | |
b1b02be2 | 4106 | |
36f5ada1 ZD |
4107 | for (act = delta; act; act = act->next_change) |
4108 | { | |
4109 | from = act->old_cp; | |
4110 | to = act->new_cp; | |
4111 | gcc_assert (iv_ca_cand_for_use (ivs, act->use) == from); | |
4112 | iv_ca_set_cp (data, ivs, act->use, to); | |
8b11a64c | 4113 | } |
36f5ada1 ZD |
4114 | |
4115 | if (!forward) | |
4116 | iv_ca_delta_reverse (delta); | |
b1b02be2 | 4117 | } |
8b11a64c | 4118 | |
b1b02be2 | 4119 | /* Returns true if CAND is used in IVS. */ |
8b11a64c | 4120 | |
b1b02be2 ZD |
4121 | static bool |
4122 | iv_ca_cand_used_p (struct iv_ca *ivs, struct iv_cand *cand) | |
4123 | { | |
4124 | return ivs->n_cand_uses[cand->id] > 0; | |
4125 | } | |
8b11a64c | 4126 | |
36f5ada1 ZD |
4127 | /* Returns number of induction variable candidates in the set IVS. */ |
4128 | ||
4129 | static unsigned | |
4130 | iv_ca_n_cands (struct iv_ca *ivs) | |
4131 | { | |
4132 | return ivs->n_cands; | |
4133 | } | |
4134 | ||
b1b02be2 ZD |
4135 | /* Free the list of changes DELTA. */ |
4136 | ||
4137 | static void | |
4138 | iv_ca_delta_free (struct iv_ca_delta **delta) | |
4139 | { | |
4140 | struct iv_ca_delta *act, *next; | |
4141 | ||
4142 | for (act = *delta; act; act = next) | |
87c476a2 | 4143 | { |
b1b02be2 ZD |
4144 | next = act->next_change; |
4145 | free (act); | |
87c476a2 | 4146 | } |
8b11a64c | 4147 | |
b1b02be2 ZD |
4148 | *delta = NULL; |
4149 | } | |
4150 | ||
4151 | /* Allocates new iv candidates assignment. */ | |
4152 | ||
4153 | static struct iv_ca * | |
4154 | iv_ca_new (struct ivopts_data *data) | |
4155 | { | |
4156 | struct iv_ca *nw = xmalloc (sizeof (struct iv_ca)); | |
8b11a64c | 4157 | |
b1b02be2 ZD |
4158 | nw->upto = 0; |
4159 | nw->bad_uses = 0; | |
4160 | nw->cand_for_use = xcalloc (n_iv_uses (data), sizeof (struct cost_pair *)); | |
4161 | nw->n_cand_uses = xcalloc (n_iv_cands (data), sizeof (unsigned)); | |
8bdbfff5 | 4162 | nw->cands = BITMAP_ALLOC (NULL); |
36f5ada1 | 4163 | nw->n_cands = 0; |
b1b02be2 ZD |
4164 | nw->n_regs = 0; |
4165 | nw->cand_use_cost = 0; | |
4166 | nw->cand_cost = 0; | |
4167 | nw->n_invariant_uses = xcalloc (data->max_inv_id + 1, sizeof (unsigned)); | |
4168 | nw->cost = 0; | |
4169 | ||
4170 | return nw; | |
4171 | } | |
4172 | ||
4173 | /* Free memory occupied by the set IVS. */ | |
4174 | ||
4175 | static void | |
4176 | iv_ca_free (struct iv_ca **ivs) | |
4177 | { | |
4178 | free ((*ivs)->cand_for_use); | |
4179 | free ((*ivs)->n_cand_uses); | |
8bdbfff5 | 4180 | BITMAP_FREE ((*ivs)->cands); |
b1b02be2 ZD |
4181 | free ((*ivs)->n_invariant_uses); |
4182 | free (*ivs); | |
4183 | *ivs = NULL; | |
4184 | } | |
4185 | ||
4186 | /* Dumps IVS to FILE. */ | |
4187 | ||
4188 | static void | |
4189 | iv_ca_dump (struct ivopts_data *data, FILE *file, struct iv_ca *ivs) | |
4190 | { | |
4191 | const char *pref = " invariants "; | |
4192 | unsigned i; | |
4193 | ||
4194 | fprintf (file, " cost %d\n", iv_ca_cost (ivs)); | |
4195 | bitmap_print (file, ivs->cands, " candidates ","\n"); | |
4196 | ||
4197 | for (i = 1; i <= data->max_inv_id; i++) | |
4198 | if (ivs->n_invariant_uses[i]) | |
4199 | { | |
4200 | fprintf (file, "%s%d", pref, i); | |
4201 | pref = ", "; | |
4202 | } | |
4203 | fprintf (file, "\n"); | |
4204 | } | |
4205 | ||
4206 | /* Try changing candidate in IVS to CAND for each use. Return cost of the | |
36f5ada1 ZD |
4207 | new set, and store differences in DELTA. Number of induction variables |
4208 | in the new set is stored to N_IVS. */ | |
b1b02be2 ZD |
4209 | |
4210 | static unsigned | |
4211 | iv_ca_extend (struct ivopts_data *data, struct iv_ca *ivs, | |
36f5ada1 ZD |
4212 | struct iv_cand *cand, struct iv_ca_delta **delta, |
4213 | unsigned *n_ivs) | |
b1b02be2 ZD |
4214 | { |
4215 | unsigned i, cost; | |
4216 | struct iv_use *use; | |
4217 | struct cost_pair *old_cp, *new_cp; | |
4218 | ||
4219 | *delta = NULL; | |
4220 | for (i = 0; i < ivs->upto; i++) | |
4221 | { | |
4222 | use = iv_use (data, i); | |
4223 | old_cp = iv_ca_cand_for_use (ivs, use); | |
4224 | ||
4225 | if (old_cp | |
4226 | && old_cp->cand == cand) | |
4227 | continue; | |
4228 | ||
4229 | new_cp = get_use_iv_cost (data, use, cand); | |
4230 | if (!new_cp) | |
4231 | continue; | |
4232 | ||
4233 | if (!iv_ca_has_deps (ivs, new_cp)) | |
4234 | continue; | |
4235 | ||
4236 | if (!cheaper_cost_pair (new_cp, old_cp)) | |
4237 | continue; | |
4238 | ||
4239 | *delta = iv_ca_delta_add (use, old_cp, new_cp, *delta); | |
4240 | } | |
4241 | ||
4242 | iv_ca_delta_commit (data, ivs, *delta, true); | |
4243 | cost = iv_ca_cost (ivs); | |
36f5ada1 ZD |
4244 | if (n_ivs) |
4245 | *n_ivs = iv_ca_n_cands (ivs); | |
b1b02be2 | 4246 | iv_ca_delta_commit (data, ivs, *delta, false); |
8b11a64c ZD |
4247 | |
4248 | return cost; | |
4249 | } | |
4250 | ||
a0eca485 | 4251 | /* Try narrowing set IVS by removing CAND. Return the cost of |
b1b02be2 | 4252 | the new set and store the differences in DELTA. */ |
8b11a64c ZD |
4253 | |
4254 | static unsigned | |
b1b02be2 ZD |
4255 | iv_ca_narrow (struct ivopts_data *data, struct iv_ca *ivs, |
4256 | struct iv_cand *cand, struct iv_ca_delta **delta) | |
8b11a64c | 4257 | { |
b1b02be2 ZD |
4258 | unsigned i, ci; |
4259 | struct iv_use *use; | |
4260 | struct cost_pair *old_cp, *new_cp, *cp; | |
4261 | bitmap_iterator bi; | |
4262 | struct iv_cand *cnd; | |
4263 | unsigned cost; | |
4264 | ||
4265 | *delta = NULL; | |
4266 | for (i = 0; i < n_iv_uses (data); i++) | |
4267 | { | |
4268 | use = iv_use (data, i); | |
4269 | ||
4270 | old_cp = iv_ca_cand_for_use (ivs, use); | |
4271 | if (old_cp->cand != cand) | |
4272 | continue; | |
4273 | ||
4274 | new_cp = NULL; | |
4275 | ||
4276 | if (data->consider_all_candidates) | |
4277 | { | |
4278 | EXECUTE_IF_SET_IN_BITMAP (ivs->cands, 0, ci, bi) | |
4279 | { | |
4280 | if (ci == cand->id) | |
4281 | continue; | |
4282 | ||
4283 | cnd = iv_cand (data, ci); | |
4284 | ||
4285 | cp = get_use_iv_cost (data, use, cnd); | |
4286 | if (!cp) | |
4287 | continue; | |
4288 | if (!iv_ca_has_deps (ivs, cp)) | |
4289 | continue; | |
4290 | ||
4291 | if (!cheaper_cost_pair (cp, new_cp)) | |
4292 | continue; | |
4293 | ||
4294 | new_cp = cp; | |
4295 | } | |
4296 | } | |
4297 | else | |
4298 | { | |
4299 | EXECUTE_IF_AND_IN_BITMAP (use->related_cands, ivs->cands, 0, ci, bi) | |
4300 | { | |
4301 | if (ci == cand->id) | |
4302 | continue; | |
4303 | ||
4304 | cnd = iv_cand (data, ci); | |
4305 | ||
4306 | cp = get_use_iv_cost (data, use, cnd); | |
4307 | if (!cp) | |
4308 | continue; | |
4309 | if (!iv_ca_has_deps (ivs, cp)) | |
4310 | continue; | |
4311 | ||
4312 | if (!cheaper_cost_pair (cp, new_cp)) | |
4313 | continue; | |
4314 | ||
4315 | new_cp = cp; | |
4316 | } | |
4317 | } | |
4318 | ||
4319 | if (!new_cp) | |
4320 | { | |
4321 | iv_ca_delta_free (delta); | |
4322 | return INFTY; | |
4323 | } | |
4324 | ||
4325 | *delta = iv_ca_delta_add (use, old_cp, new_cp, *delta); | |
4326 | } | |
4327 | ||
4328 | iv_ca_delta_commit (data, ivs, *delta, true); | |
4329 | cost = iv_ca_cost (ivs); | |
4330 | iv_ca_delta_commit (data, ivs, *delta, false); | |
4331 | ||
4332 | return cost; | |
8b11a64c ZD |
4333 | } |
4334 | ||
36f5ada1 ZD |
4335 | /* Try optimizing the set of candidates IVS by removing candidates different |
4336 | from to EXCEPT_CAND from it. Return cost of the new set, and store | |
4337 | differences in DELTA. */ | |
4338 | ||
4339 | static unsigned | |
4340 | iv_ca_prune (struct ivopts_data *data, struct iv_ca *ivs, | |
4341 | struct iv_cand *except_cand, struct iv_ca_delta **delta) | |
4342 | { | |
4343 | bitmap_iterator bi; | |
4344 | struct iv_ca_delta *act_delta, *best_delta; | |
4345 | unsigned i, best_cost, acost; | |
4346 | struct iv_cand *cand; | |
4347 | ||
4348 | best_delta = NULL; | |
4349 | best_cost = iv_ca_cost (ivs); | |
4350 | ||
4351 | EXECUTE_IF_SET_IN_BITMAP (ivs->cands, 0, i, bi) | |
4352 | { | |
4353 | cand = iv_cand (data, i); | |
4354 | ||
4355 | if (cand == except_cand) | |
4356 | continue; | |
4357 | ||
4358 | acost = iv_ca_narrow (data, ivs, cand, &act_delta); | |
4359 | ||
4360 | if (acost < best_cost) | |
4361 | { | |
4362 | best_cost = acost; | |
4363 | iv_ca_delta_free (&best_delta); | |
4364 | best_delta = act_delta; | |
4365 | } | |
4366 | else | |
4367 | iv_ca_delta_free (&act_delta); | |
4368 | } | |
4369 | ||
4370 | if (!best_delta) | |
4371 | { | |
4372 | *delta = NULL; | |
4373 | return best_cost; | |
4374 | } | |
4375 | ||
4376 | /* Recurse to possibly remove other unnecessary ivs. */ | |
4377 | iv_ca_delta_commit (data, ivs, best_delta, true); | |
4378 | best_cost = iv_ca_prune (data, ivs, except_cand, delta); | |
4379 | iv_ca_delta_commit (data, ivs, best_delta, false); | |
4380 | *delta = iv_ca_delta_join (best_delta, *delta); | |
4381 | return best_cost; | |
4382 | } | |
4383 | ||
b1b02be2 | 4384 | /* Tries to extend the sets IVS in the best possible way in order |
8b11a64c ZD |
4385 | to express the USE. */ |
4386 | ||
4387 | static bool | |
b1b02be2 | 4388 | try_add_cand_for (struct ivopts_data *data, struct iv_ca *ivs, |
8b11a64c ZD |
4389 | struct iv_use *use) |
4390 | { | |
b1b02be2 | 4391 | unsigned best_cost, act_cost; |
8b11a64c | 4392 | unsigned i; |
38b0dcb8 ZD |
4393 | bitmap_iterator bi; |
4394 | struct iv_cand *cand; | |
b1b02be2 ZD |
4395 | struct iv_ca_delta *best_delta = NULL, *act_delta; |
4396 | struct cost_pair *cp; | |
4397 | ||
4398 | iv_ca_add_use (data, ivs, use); | |
4399 | best_cost = iv_ca_cost (ivs); | |
8b11a64c | 4400 | |
b1b02be2 ZD |
4401 | cp = iv_ca_cand_for_use (ivs, use); |
4402 | if (cp) | |
4403 | { | |
4404 | best_delta = iv_ca_delta_add (use, NULL, cp, NULL); | |
4405 | iv_ca_set_no_cp (data, ivs, use); | |
4406 | } | |
8b11a64c | 4407 | |
38b0dcb8 ZD |
4408 | /* First try important candidates. Only if it fails, try the specific ones. |
4409 | Rationale -- in loops with many variables the best choice often is to use | |
4410 | just one generic biv. If we added here many ivs specific to the uses, | |
4411 | the optimization algorithm later would be likely to get stuck in a local | |
4412 | minimum, thus causing us to create too many ivs. The approach from | |
1c170b5e | 4413 | few ivs to more seems more likely to be successful -- starting from few |
38b0dcb8 ZD |
4414 | ivs, replacing an expensive use by a specific iv should always be a |
4415 | win. */ | |
4416 | EXECUTE_IF_SET_IN_BITMAP (data->important_candidates, 0, i, bi) | |
8b11a64c | 4417 | { |
38b0dcb8 ZD |
4418 | cand = iv_cand (data, i); |
4419 | ||
b1b02be2 | 4420 | if (iv_ca_cand_used_p (ivs, cand)) |
8b11a64c ZD |
4421 | continue; |
4422 | ||
b1b02be2 ZD |
4423 | cp = get_use_iv_cost (data, use, cand); |
4424 | if (!cp) | |
4425 | continue; | |
4426 | ||
4427 | iv_ca_set_cp (data, ivs, use, cp); | |
36f5ada1 | 4428 | act_cost = iv_ca_extend (data, ivs, cand, &act_delta, NULL); |
b1b02be2 ZD |
4429 | iv_ca_set_no_cp (data, ivs, use); |
4430 | act_delta = iv_ca_delta_add (use, NULL, cp, act_delta); | |
8b11a64c ZD |
4431 | |
4432 | if (act_cost < best_cost) | |
4433 | { | |
4434 | best_cost = act_cost; | |
b1b02be2 ZD |
4435 | |
4436 | iv_ca_delta_free (&best_delta); | |
4437 | best_delta = act_delta; | |
8b11a64c | 4438 | } |
b1b02be2 ZD |
4439 | else |
4440 | iv_ca_delta_free (&act_delta); | |
8b11a64c ZD |
4441 | } |
4442 | ||
38b0dcb8 ZD |
4443 | if (best_cost == INFTY) |
4444 | { | |
4445 | for (i = 0; i < use->n_map_members; i++) | |
4446 | { | |
4447 | cp = use->cost_map + i; | |
b1b02be2 ZD |
4448 | cand = cp->cand; |
4449 | if (!cand) | |
38b0dcb8 ZD |
4450 | continue; |
4451 | ||
4452 | /* Already tried this. */ | |
b1b02be2 ZD |
4453 | if (cand->important) |
4454 | continue; | |
4455 | ||
4456 | if (iv_ca_cand_used_p (ivs, cand)) | |
38b0dcb8 ZD |
4457 | continue; |
4458 | ||
b1b02be2 ZD |
4459 | act_delta = NULL; |
4460 | iv_ca_set_cp (data, ivs, use, cp); | |
36f5ada1 | 4461 | act_cost = iv_ca_extend (data, ivs, cand, &act_delta, NULL); |
b1b02be2 ZD |
4462 | iv_ca_set_no_cp (data, ivs, use); |
4463 | act_delta = iv_ca_delta_add (use, iv_ca_cand_for_use (ivs, use), | |
4464 | cp, act_delta); | |
38b0dcb8 ZD |
4465 | |
4466 | if (act_cost < best_cost) | |
4467 | { | |
4468 | best_cost = act_cost; | |
b1b02be2 ZD |
4469 | |
4470 | if (best_delta) | |
4471 | iv_ca_delta_free (&best_delta); | |
4472 | best_delta = act_delta; | |
38b0dcb8 | 4473 | } |
b1b02be2 ZD |
4474 | else |
4475 | iv_ca_delta_free (&act_delta); | |
38b0dcb8 ZD |
4476 | } |
4477 | } | |
4478 | ||
b1b02be2 ZD |
4479 | iv_ca_delta_commit (data, ivs, best_delta, true); |
4480 | iv_ca_delta_free (&best_delta); | |
8b11a64c ZD |
4481 | |
4482 | return (best_cost != INFTY); | |
4483 | } | |
4484 | ||
b1b02be2 | 4485 | /* Finds an initial assignment of candidates to uses. */ |
8b11a64c | 4486 | |
b1b02be2 ZD |
4487 | static struct iv_ca * |
4488 | get_initial_solution (struct ivopts_data *data) | |
8b11a64c | 4489 | { |
b1b02be2 | 4490 | struct iv_ca *ivs = iv_ca_new (data); |
8b11a64c ZD |
4491 | unsigned i; |
4492 | ||
4493 | for (i = 0; i < n_iv_uses (data); i++) | |
b1b02be2 ZD |
4494 | if (!try_add_cand_for (data, ivs, iv_use (data, i))) |
4495 | { | |
4496 | iv_ca_free (&ivs); | |
4497 | return NULL; | |
4498 | } | |
8b11a64c | 4499 | |
b1b02be2 | 4500 | return ivs; |
8b11a64c ZD |
4501 | } |
4502 | ||
b1b02be2 | 4503 | /* Tries to improve set of induction variables IVS. */ |
8b11a64c ZD |
4504 | |
4505 | static bool | |
b1b02be2 | 4506 | try_improve_iv_set (struct ivopts_data *data, struct iv_ca *ivs) |
8b11a64c | 4507 | { |
36f5ada1 ZD |
4508 | unsigned i, acost, best_cost = iv_ca_cost (ivs), n_ivs; |
4509 | struct iv_ca_delta *best_delta = NULL, *act_delta, *tmp_delta; | |
b1b02be2 | 4510 | struct iv_cand *cand; |
8b11a64c | 4511 | |
36f5ada1 | 4512 | /* Try extending the set of induction variables by one. */ |
8b11a64c ZD |
4513 | for (i = 0; i < n_iv_cands (data); i++) |
4514 | { | |
b1b02be2 ZD |
4515 | cand = iv_cand (data, i); |
4516 | ||
4517 | if (iv_ca_cand_used_p (ivs, cand)) | |
36f5ada1 ZD |
4518 | continue; |
4519 | ||
4520 | acost = iv_ca_extend (data, ivs, cand, &act_delta, &n_ivs); | |
4521 | if (!act_delta) | |
4522 | continue; | |
4523 | ||
4524 | /* If we successfully added the candidate and the set is small enough, | |
4525 | try optimizing it by removing other candidates. */ | |
4526 | if (n_ivs <= ALWAYS_PRUNE_CAND_SET_BOUND) | |
4527 | { | |
4528 | iv_ca_delta_commit (data, ivs, act_delta, true); | |
4529 | acost = iv_ca_prune (data, ivs, cand, &tmp_delta); | |
4530 | iv_ca_delta_commit (data, ivs, act_delta, false); | |
4531 | act_delta = iv_ca_delta_join (act_delta, tmp_delta); | |
4532 | } | |
8b11a64c | 4533 | |
b1b02be2 | 4534 | if (acost < best_cost) |
8b11a64c | 4535 | { |
b1b02be2 | 4536 | best_cost = acost; |
36f5ada1 | 4537 | iv_ca_delta_free (&best_delta); |
b1b02be2 | 4538 | best_delta = act_delta; |
8b11a64c | 4539 | } |
8b11a64c | 4540 | else |
b1b02be2 | 4541 | iv_ca_delta_free (&act_delta); |
8b11a64c ZD |
4542 | } |
4543 | ||
b1b02be2 | 4544 | if (!best_delta) |
36f5ada1 ZD |
4545 | { |
4546 | /* Try removing the candidates from the set instead. */ | |
4547 | best_cost = iv_ca_prune (data, ivs, NULL, &best_delta); | |
4548 | ||
4549 | /* Nothing more we can do. */ | |
4550 | if (!best_delta) | |
4551 | return false; | |
4552 | } | |
8b11a64c | 4553 | |
b1b02be2 | 4554 | iv_ca_delta_commit (data, ivs, best_delta, true); |
36f5ada1 | 4555 | gcc_assert (best_cost == iv_ca_cost (ivs)); |
b1b02be2 | 4556 | iv_ca_delta_free (&best_delta); |
8b11a64c ZD |
4557 | return true; |
4558 | } | |
4559 | ||
4560 | /* Attempts to find the optimal set of induction variables. We do simple | |
4561 | greedy heuristic -- we try to replace at most one candidate in the selected | |
4562 | solution and remove the unused ivs while this improves the cost. */ | |
4563 | ||
b1b02be2 | 4564 | static struct iv_ca * |
8b11a64c ZD |
4565 | find_optimal_iv_set (struct ivopts_data *data) |
4566 | { | |
b1b02be2 ZD |
4567 | unsigned i; |
4568 | struct iv_ca *set; | |
8b11a64c ZD |
4569 | struct iv_use *use; |
4570 | ||
b1b02be2 ZD |
4571 | /* Get the initial solution. */ |
4572 | set = get_initial_solution (data); | |
4573 | if (!set) | |
8b11a64c ZD |
4574 | { |
4575 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4576 | fprintf (dump_file, "Unable to substitute for ivs, failed.\n"); | |
8b11a64c ZD |
4577 | return NULL; |
4578 | } | |
4579 | ||
4580 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4581 | { | |
b1b02be2 ZD |
4582 | fprintf (dump_file, "Initial set of candidates:\n"); |
4583 | iv_ca_dump (data, dump_file, set); | |
8b11a64c ZD |
4584 | } |
4585 | ||
b1b02be2 | 4586 | while (try_improve_iv_set (data, set)) |
8b11a64c ZD |
4587 | { |
4588 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4589 | { | |
b1b02be2 ZD |
4590 | fprintf (dump_file, "Improved to:\n"); |
4591 | iv_ca_dump (data, dump_file, set); | |
8b11a64c ZD |
4592 | } |
4593 | } | |
4594 | ||
4595 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
b1b02be2 | 4596 | fprintf (dump_file, "Final cost %d\n\n", iv_ca_cost (set)); |
8b11a64c ZD |
4597 | |
4598 | for (i = 0; i < n_iv_uses (data); i++) | |
4599 | { | |
4600 | use = iv_use (data, i); | |
b1b02be2 | 4601 | use->selected = iv_ca_cand_for_use (set, use)->cand; |
8b11a64c ZD |
4602 | } |
4603 | ||
8b11a64c ZD |
4604 | return set; |
4605 | } | |
4606 | ||
4607 | /* Creates a new induction variable corresponding to CAND. */ | |
4608 | ||
4609 | static void | |
4610 | create_new_iv (struct ivopts_data *data, struct iv_cand *cand) | |
4611 | { | |
4612 | block_stmt_iterator incr_pos; | |
4613 | tree base; | |
4614 | bool after = false; | |
4615 | ||
4616 | if (!cand->iv) | |
4617 | return; | |
4618 | ||
4619 | switch (cand->pos) | |
4620 | { | |
4621 | case IP_NORMAL: | |
4622 | incr_pos = bsi_last (ip_normal_pos (data->current_loop)); | |
4623 | break; | |
4624 | ||
4625 | case IP_END: | |
4626 | incr_pos = bsi_last (ip_end_pos (data->current_loop)); | |
4627 | after = true; | |
4628 | break; | |
4629 | ||
4630 | case IP_ORIGINAL: | |
4631 | /* Mark that the iv is preserved. */ | |
4632 | name_info (data, cand->var_before)->preserve_biv = true; | |
4633 | name_info (data, cand->var_after)->preserve_biv = true; | |
4634 | ||
4635 | /* Rewrite the increment so that it uses var_before directly. */ | |
4636 | find_interesting_uses_op (data, cand->var_after)->selected = cand; | |
4637 | ||
4638 | return; | |
4639 | } | |
4640 | ||
4641 | gimple_add_tmp_var (cand->var_before); | |
4642 | add_referenced_tmp_var (cand->var_before); | |
4643 | ||
4644 | base = unshare_expr (cand->iv->base); | |
4645 | ||
4646 | create_iv (base, cand->iv->step, cand->var_before, data->current_loop, | |
4647 | &incr_pos, after, &cand->var_before, &cand->var_after); | |
4648 | } | |
4649 | ||
4650 | /* Creates new induction variables described in SET. */ | |
4651 | ||
4652 | static void | |
b1b02be2 | 4653 | create_new_ivs (struct ivopts_data *data, struct iv_ca *set) |
8b11a64c ZD |
4654 | { |
4655 | unsigned i; | |
4656 | struct iv_cand *cand; | |
87c476a2 | 4657 | bitmap_iterator bi; |
8b11a64c | 4658 | |
b1b02be2 | 4659 | EXECUTE_IF_SET_IN_BITMAP (set->cands, 0, i, bi) |
8b11a64c ZD |
4660 | { |
4661 | cand = iv_cand (data, i); | |
4662 | create_new_iv (data, cand); | |
87c476a2 | 4663 | } |
8b11a64c ZD |
4664 | } |
4665 | ||
4666 | /* Removes statement STMT (real or a phi node). If INCLUDING_DEFINED_NAME | |
4667 | is true, remove also the ssa name defined by the statement. */ | |
4668 | ||
4669 | static void | |
4670 | remove_statement (tree stmt, bool including_defined_name) | |
4671 | { | |
4672 | if (TREE_CODE (stmt) == PHI_NODE) | |
4673 | { | |
4674 | if (!including_defined_name) | |
4675 | { | |
4676 | /* Prevent the ssa name defined by the statement from being removed. */ | |
4677 | SET_PHI_RESULT (stmt, NULL); | |
4678 | } | |
d19e3ef6 | 4679 | remove_phi_node (stmt, NULL_TREE); |
8b11a64c ZD |
4680 | } |
4681 | else | |
4682 | { | |
1a1804c2 | 4683 | block_stmt_iterator bsi = bsi_for_stmt (stmt); |
8b11a64c ZD |
4684 | |
4685 | bsi_remove (&bsi); | |
4686 | } | |
4687 | } | |
4688 | ||
4689 | /* Rewrites USE (definition of iv used in a nonlinear expression) | |
4690 | using candidate CAND. */ | |
4691 | ||
4692 | static void | |
4693 | rewrite_use_nonlinear_expr (struct ivopts_data *data, | |
4694 | struct iv_use *use, struct iv_cand *cand) | |
4695 | { | |
3520b745 | 4696 | tree comp; |
8b11a64c ZD |
4697 | tree op, stmts, tgt, ass; |
4698 | block_stmt_iterator bsi, pbsi; | |
3520b745 ZD |
4699 | |
4700 | /* An important special case -- if we are asked to express value of | |
4701 | the original iv by itself, just exit; there is no need to | |
4702 | introduce a new computation (that might also need casting the | |
4703 | variable to unsigned and back). */ | |
4704 | if (cand->pos == IP_ORIGINAL | |
4705 | && TREE_CODE (use->stmt) == MODIFY_EXPR | |
4706 | && TREE_OPERAND (use->stmt, 0) == cand->var_after) | |
4707 | { | |
4708 | op = TREE_OPERAND (use->stmt, 1); | |
4709 | ||
4710 | /* Be a bit careful. In case variable is expressed in some | |
4711 | complicated way, rewrite it so that we may get rid of this | |
4712 | complicated expression. */ | |
4713 | if ((TREE_CODE (op) == PLUS_EXPR | |
4714 | || TREE_CODE (op) == MINUS_EXPR) | |
4715 | && TREE_OPERAND (op, 0) == cand->var_before | |
4716 | && TREE_CODE (TREE_OPERAND (op, 1)) == INTEGER_CST) | |
4717 | return; | |
4718 | } | |
4719 | ||
4720 | comp = unshare_expr (get_computation (data->current_loop, | |
4721 | use, cand)); | |
1e128c5f | 4722 | switch (TREE_CODE (use->stmt)) |
8b11a64c | 4723 | { |
1e128c5f | 4724 | case PHI_NODE: |
8b11a64c ZD |
4725 | tgt = PHI_RESULT (use->stmt); |
4726 | ||
4727 | /* If we should keep the biv, do not replace it. */ | |
4728 | if (name_info (data, tgt)->preserve_biv) | |
4729 | return; | |
4730 | ||
4731 | pbsi = bsi = bsi_start (bb_for_stmt (use->stmt)); | |
4732 | while (!bsi_end_p (pbsi) | |
4733 | && TREE_CODE (bsi_stmt (pbsi)) == LABEL_EXPR) | |
4734 | { | |
4735 | bsi = pbsi; | |
4736 | bsi_next (&pbsi); | |
4737 | } | |
1e128c5f GB |
4738 | break; |
4739 | ||
4740 | case MODIFY_EXPR: | |
8b11a64c | 4741 | tgt = TREE_OPERAND (use->stmt, 0); |
1a1804c2 | 4742 | bsi = bsi_for_stmt (use->stmt); |
1e128c5f GB |
4743 | break; |
4744 | ||
4745 | default: | |
4746 | gcc_unreachable (); | |
8b11a64c | 4747 | } |
8b11a64c ZD |
4748 | |
4749 | op = force_gimple_operand (comp, &stmts, false, SSA_NAME_VAR (tgt)); | |
4750 | ||
4751 | if (TREE_CODE (use->stmt) == PHI_NODE) | |
4752 | { | |
4753 | if (stmts) | |
4754 | bsi_insert_after (&bsi, stmts, BSI_CONTINUE_LINKING); | |
4755 | ass = build2 (MODIFY_EXPR, TREE_TYPE (tgt), tgt, op); | |
4756 | bsi_insert_after (&bsi, ass, BSI_NEW_STMT); | |
4757 | remove_statement (use->stmt, false); | |
4758 | SSA_NAME_DEF_STMT (tgt) = ass; | |
4759 | } | |
4760 | else | |
4761 | { | |
4762 | if (stmts) | |
4763 | bsi_insert_before (&bsi, stmts, BSI_SAME_STMT); | |
4764 | TREE_OPERAND (use->stmt, 1) = op; | |
4765 | } | |
4766 | } | |
4767 | ||
4768 | /* Replaces ssa name in index IDX by its basic variable. Callback for | |
4769 | for_each_index. */ | |
4770 | ||
4771 | static bool | |
be35cf60 | 4772 | idx_remove_ssa_names (tree base, tree *idx, |
8b11a64c ZD |
4773 | void *data ATTRIBUTE_UNUSED) |
4774 | { | |
be35cf60 ZD |
4775 | tree *op; |
4776 | ||
8b11a64c ZD |
4777 | if (TREE_CODE (*idx) == SSA_NAME) |
4778 | *idx = SSA_NAME_VAR (*idx); | |
be35cf60 ZD |
4779 | |
4780 | if (TREE_CODE (base) == ARRAY_REF) | |
4781 | { | |
4782 | op = &TREE_OPERAND (base, 2); | |
4783 | if (*op | |
4784 | && TREE_CODE (*op) == SSA_NAME) | |
4785 | *op = SSA_NAME_VAR (*op); | |
4786 | op = &TREE_OPERAND (base, 3); | |
4787 | if (*op | |
4788 | && TREE_CODE (*op) == SSA_NAME) | |
4789 | *op = SSA_NAME_VAR (*op); | |
4790 | } | |
4791 | ||
8b11a64c ZD |
4792 | return true; |
4793 | } | |
4794 | ||
4795 | /* Unshares REF and replaces ssa names inside it by their basic variables. */ | |
4796 | ||
4797 | static tree | |
4798 | unshare_and_remove_ssa_names (tree ref) | |
4799 | { | |
4800 | ref = unshare_expr (ref); | |
4801 | for_each_index (&ref, idx_remove_ssa_names, NULL); | |
4802 | ||
4803 | return ref; | |
4804 | } | |
4805 | ||
4806 | /* Rewrites base of memory access OP with expression WITH in statement | |
4807 | pointed to by BSI. */ | |
4808 | ||
4809 | static void | |
4810 | rewrite_address_base (block_stmt_iterator *bsi, tree *op, tree with) | |
4811 | { | |
0bca51f0 | 4812 | tree bvar, var, new_name, copy, name; |
8b11a64c ZD |
4813 | tree orig; |
4814 | ||
7ccf35ed DN |
4815 | var = bvar = get_base_address (*op); |
4816 | ||
8b11a64c ZD |
4817 | if (!var || TREE_CODE (with) != SSA_NAME) |
4818 | goto do_rewrite; | |
be35cf60 ZD |
4819 | |
4820 | gcc_assert (TREE_CODE (var) != ALIGN_INDIRECT_REF); | |
4821 | gcc_assert (TREE_CODE (var) != MISALIGNED_INDIRECT_REF); | |
4822 | if (TREE_CODE (var) == INDIRECT_REF) | |
8b11a64c ZD |
4823 | var = TREE_OPERAND (var, 0); |
4824 | if (TREE_CODE (var) == SSA_NAME) | |
4825 | { | |
4826 | name = var; | |
4827 | var = SSA_NAME_VAR (var); | |
4828 | } | |
4829 | else if (DECL_P (var)) | |
4830 | name = NULL_TREE; | |
4831 | else | |
4832 | goto do_rewrite; | |
4833 | ||
8b11a64c ZD |
4834 | /* We need to add a memory tag for the variable. But we do not want |
4835 | to add it to the temporary used for the computations, since this leads | |
4836 | to problems in redundancy elimination when there are common parts | |
4837 | in two computations referring to the different arrays. So we copy | |
4838 | the variable to a new temporary. */ | |
4839 | copy = build2 (MODIFY_EXPR, void_type_node, NULL_TREE, with); | |
0bca51f0 | 4840 | |
8b11a64c ZD |
4841 | if (name) |
4842 | new_name = duplicate_ssa_name (name, copy); | |
4843 | else | |
4844 | { | |
0bca51f0 DN |
4845 | tree tag = var_ann (var)->type_mem_tag; |
4846 | tree new_ptr = create_tmp_var (TREE_TYPE (with), "ruatmp"); | |
4847 | add_referenced_tmp_var (new_ptr); | |
4848 | if (tag) | |
4849 | var_ann (new_ptr)->type_mem_tag = tag; | |
4850 | else | |
4851 | add_type_alias (new_ptr, var); | |
4852 | new_name = make_ssa_name (new_ptr, copy); | |
8b11a64c | 4853 | } |
0bca51f0 | 4854 | |
8b11a64c | 4855 | TREE_OPERAND (copy, 0) = new_name; |
f430bae8 | 4856 | update_stmt (copy); |
8b11a64c ZD |
4857 | bsi_insert_before (bsi, copy, BSI_SAME_STMT); |
4858 | with = new_name; | |
4859 | ||
4860 | do_rewrite: | |
4861 | ||
4862 | orig = NULL_TREE; | |
be35cf60 ZD |
4863 | gcc_assert (TREE_CODE (*op) != ALIGN_INDIRECT_REF); |
4864 | gcc_assert (TREE_CODE (*op) != MISALIGNED_INDIRECT_REF); | |
4865 | ||
4866 | if (TREE_CODE (*op) == INDIRECT_REF) | |
8b11a64c ZD |
4867 | orig = REF_ORIGINAL (*op); |
4868 | if (!orig) | |
4869 | orig = unshare_and_remove_ssa_names (*op); | |
4870 | ||
be35cf60 | 4871 | *op = build1 (INDIRECT_REF, TREE_TYPE (*op), with); |
7ccf35ed | 4872 | |
8b11a64c ZD |
4873 | /* Record the original reference, for purposes of alias analysis. */ |
4874 | REF_ORIGINAL (*op) = orig; | |
0bca51f0 DN |
4875 | |
4876 | /* Virtual operands in the original statement may have to be renamed | |
4877 | because of the replacement. */ | |
4878 | mark_new_vars_to_rename (bsi_stmt (*bsi)); | |
8b11a64c ZD |
4879 | } |
4880 | ||
4881 | /* Rewrites USE (address that is an iv) using candidate CAND. */ | |
4882 | ||
4883 | static void | |
4884 | rewrite_use_address (struct ivopts_data *data, | |
4885 | struct iv_use *use, struct iv_cand *cand) | |
4886 | { | |
4887 | tree comp = unshare_expr (get_computation (data->current_loop, | |
4888 | use, cand)); | |
1a1804c2 | 4889 | block_stmt_iterator bsi = bsi_for_stmt (use->stmt); |
8b11a64c ZD |
4890 | tree stmts; |
4891 | tree op = force_gimple_operand (comp, &stmts, true, NULL_TREE); | |
4892 | ||
4893 | if (stmts) | |
4894 | bsi_insert_before (&bsi, stmts, BSI_SAME_STMT); | |
4895 | ||
4896 | rewrite_address_base (&bsi, use->op_p, op); | |
4897 | } | |
4898 | ||
4899 | /* Rewrites USE (the condition such that one of the arguments is an iv) using | |
4900 | candidate CAND. */ | |
4901 | ||
4902 | static void | |
4903 | rewrite_use_compare (struct ivopts_data *data, | |
4904 | struct iv_use *use, struct iv_cand *cand) | |
4905 | { | |
4906 | tree comp; | |
4907 | tree *op_p, cond, op, stmts, bound; | |
1a1804c2 | 4908 | block_stmt_iterator bsi = bsi_for_stmt (use->stmt); |
8b11a64c ZD |
4909 | enum tree_code compare; |
4910 | ||
ca4c3169 | 4911 | if (may_eliminate_iv (data, use, cand, &compare, &bound)) |
8b11a64c | 4912 | { |
9e7376e5 ZD |
4913 | tree var = var_at_stmt (data->current_loop, cand, use->stmt); |
4914 | tree var_type = TREE_TYPE (var); | |
4915 | ||
4916 | bound = fold_convert (var_type, bound); | |
8b11a64c ZD |
4917 | op = force_gimple_operand (unshare_expr (bound), &stmts, |
4918 | true, NULL_TREE); | |
4919 | ||
4920 | if (stmts) | |
4921 | bsi_insert_before (&bsi, stmts, BSI_SAME_STMT); | |
4922 | ||
9e7376e5 | 4923 | *use->op_p = build2 (compare, boolean_type_node, var, op); |
f430bae8 | 4924 | update_stmt (use->stmt); |
8b11a64c ZD |
4925 | return; |
4926 | } | |
4927 | ||
4928 | /* The induction variable elimination failed; just express the original | |
4929 | giv. */ | |
4930 | comp = unshare_expr (get_computation (data->current_loop, use, cand)); | |
4931 | ||
4932 | cond = *use->op_p; | |
4933 | op_p = &TREE_OPERAND (cond, 0); | |
4934 | if (TREE_CODE (*op_p) != SSA_NAME | |
4935 | || zero_p (get_iv (data, *op_p)->step)) | |
4936 | op_p = &TREE_OPERAND (cond, 1); | |
4937 | ||
4938 | op = force_gimple_operand (comp, &stmts, true, SSA_NAME_VAR (*op_p)); | |
4939 | if (stmts) | |
4940 | bsi_insert_before (&bsi, stmts, BSI_SAME_STMT); | |
4941 | ||
4942 | *op_p = op; | |
4943 | } | |
4944 | ||
4945 | /* Ensure that operand *OP_P may be used at the end of EXIT without | |
4946 | violating loop closed ssa form. */ | |
4947 | ||
4948 | static void | |
4949 | protect_loop_closed_ssa_form_use (edge exit, use_operand_p op_p) | |
4950 | { | |
4951 | basic_block def_bb; | |
4952 | struct loop *def_loop; | |
4953 | tree phi, use; | |
4954 | ||
4955 | use = USE_FROM_PTR (op_p); | |
4956 | if (TREE_CODE (use) != SSA_NAME) | |
4957 | return; | |
4958 | ||
4959 | def_bb = bb_for_stmt (SSA_NAME_DEF_STMT (use)); | |
4960 | if (!def_bb) | |
4961 | return; | |
4962 | ||
4963 | def_loop = def_bb->loop_father; | |
4964 | if (flow_bb_inside_loop_p (def_loop, exit->dest)) | |
4965 | return; | |
4966 | ||
4967 | /* Try finding a phi node that copies the value out of the loop. */ | |
bb29d951 | 4968 | for (phi = phi_nodes (exit->dest); phi; phi = PHI_CHAIN (phi)) |
8b11a64c ZD |
4969 | if (PHI_ARG_DEF_FROM_EDGE (phi, exit) == use) |
4970 | break; | |
4971 | ||
4972 | if (!phi) | |
4973 | { | |
4974 | /* Create such a phi node. */ | |
4975 | tree new_name = duplicate_ssa_name (use, NULL); | |
4976 | ||
4977 | phi = create_phi_node (new_name, exit->dest); | |
4978 | SSA_NAME_DEF_STMT (new_name) = phi; | |
d2e398df | 4979 | add_phi_arg (phi, use, exit); |
8b11a64c ZD |
4980 | } |
4981 | ||
4982 | SET_USE (op_p, PHI_RESULT (phi)); | |
4983 | } | |
4984 | ||
4985 | /* Ensure that operands of STMT may be used at the end of EXIT without | |
4986 | violating loop closed ssa form. */ | |
4987 | ||
4988 | static void | |
4989 | protect_loop_closed_ssa_form (edge exit, tree stmt) | |
4990 | { | |
4991 | use_optype uses; | |
4992 | vuse_optype vuses; | |
4993 | v_may_def_optype v_may_defs; | |
4994 | unsigned i; | |
4995 | ||
8b11a64c ZD |
4996 | uses = STMT_USE_OPS (stmt); |
4997 | for (i = 0; i < NUM_USES (uses); i++) | |
4998 | protect_loop_closed_ssa_form_use (exit, USE_OP_PTR (uses, i)); | |
4999 | ||
5000 | vuses = STMT_VUSE_OPS (stmt); | |
5001 | for (i = 0; i < NUM_VUSES (vuses); i++) | |
5002 | protect_loop_closed_ssa_form_use (exit, VUSE_OP_PTR (vuses, i)); | |
5003 | ||
5004 | v_may_defs = STMT_V_MAY_DEF_OPS (stmt); | |
5005 | for (i = 0; i < NUM_V_MAY_DEFS (v_may_defs); i++) | |
5006 | protect_loop_closed_ssa_form_use (exit, V_MAY_DEF_OP_PTR (v_may_defs, i)); | |
5007 | } | |
5008 | ||
5009 | /* STMTS compute a value of a phi argument OP on EXIT of a loop. Arrange things | |
5010 | so that they are emitted on the correct place, and so that the loop closed | |
5011 | ssa form is preserved. */ | |
5012 | ||
5013 | static void | |
5014 | compute_phi_arg_on_exit (edge exit, tree stmts, tree op) | |
5015 | { | |
5016 | tree_stmt_iterator tsi; | |
5017 | block_stmt_iterator bsi; | |
5018 | tree phi, stmt, def, next; | |
5019 | ||
c5cbcccf | 5020 | if (!single_pred_p (exit->dest)) |
8b11a64c ZD |
5021 | split_loop_exit_edge (exit); |
5022 | ||
f430bae8 AM |
5023 | /* Ensure there is label in exit->dest, so that we can |
5024 | insert after it. */ | |
5025 | tree_block_label (exit->dest); | |
5026 | bsi = bsi_after_labels (exit->dest); | |
5027 | ||
8b11a64c ZD |
5028 | if (TREE_CODE (stmts) == STATEMENT_LIST) |
5029 | { | |
5030 | for (tsi = tsi_start (stmts); !tsi_end_p (tsi); tsi_next (&tsi)) | |
f430bae8 AM |
5031 | { |
5032 | bsi_insert_after (&bsi, tsi_stmt (tsi), BSI_NEW_STMT); | |
5033 | protect_loop_closed_ssa_form (exit, bsi_stmt (bsi)); | |
5034 | } | |
8b11a64c ZD |
5035 | } |
5036 | else | |
f430bae8 AM |
5037 | { |
5038 | bsi_insert_after (&bsi, stmts, BSI_NEW_STMT); | |
5039 | protect_loop_closed_ssa_form (exit, bsi_stmt (bsi)); | |
5040 | } | |
8b11a64c ZD |
5041 | |
5042 | if (!op) | |
5043 | return; | |
5044 | ||
5045 | for (phi = phi_nodes (exit->dest); phi; phi = next) | |
5046 | { | |
eaf0dc02 | 5047 | next = PHI_CHAIN (phi); |
8b11a64c ZD |
5048 | |
5049 | if (PHI_ARG_DEF_FROM_EDGE (phi, exit) == op) | |
5050 | { | |
5051 | def = PHI_RESULT (phi); | |
5052 | remove_statement (phi, false); | |
5053 | stmt = build2 (MODIFY_EXPR, TREE_TYPE (op), | |
5054 | def, op); | |
5055 | SSA_NAME_DEF_STMT (def) = stmt; | |
5056 | bsi_insert_after (&bsi, stmt, BSI_CONTINUE_LINKING); | |
5057 | } | |
5058 | } | |
5059 | } | |
5060 | ||
5061 | /* Rewrites the final value of USE (that is only needed outside of the loop) | |
5062 | using candidate CAND. */ | |
5063 | ||
5064 | static void | |
5065 | rewrite_use_outer (struct ivopts_data *data, | |
5066 | struct iv_use *use, struct iv_cand *cand) | |
5067 | { | |
5068 | edge exit; | |
5069 | tree value, op, stmts, tgt; | |
5070 | tree phi; | |
5071 | ||
1e128c5f GB |
5072 | switch (TREE_CODE (use->stmt)) |
5073 | { | |
5074 | case PHI_NODE: | |
5075 | tgt = PHI_RESULT (use->stmt); | |
5076 | break; | |
5077 | case MODIFY_EXPR: | |
5078 | tgt = TREE_OPERAND (use->stmt, 0); | |
5079 | break; | |
5080 | default: | |
5081 | gcc_unreachable (); | |
5082 | } | |
5083 | ||
8b11a64c ZD |
5084 | exit = single_dom_exit (data->current_loop); |
5085 | ||
5086 | if (exit) | |
5087 | { | |
5088 | if (!cand->iv) | |
5089 | { | |
ca4c3169 | 5090 | bool ok = may_replace_final_value (data, use, &value); |
1e128c5f | 5091 | gcc_assert (ok); |
8b11a64c ZD |
5092 | } |
5093 | else | |
5094 | value = get_computation_at (data->current_loop, | |
5095 | use, cand, last_stmt (exit->src)); | |
5096 | ||
2f4675b4 | 5097 | value = unshare_expr (value); |
8b11a64c ZD |
5098 | op = force_gimple_operand (value, &stmts, true, SSA_NAME_VAR (tgt)); |
5099 | ||
5100 | /* If we will preserve the iv anyway and we would need to perform | |
5101 | some computation to replace the final value, do nothing. */ | |
5102 | if (stmts && name_info (data, tgt)->preserve_biv) | |
5103 | return; | |
5104 | ||
bb29d951 | 5105 | for (phi = phi_nodes (exit->dest); phi; phi = PHI_CHAIN (phi)) |
8b11a64c ZD |
5106 | { |
5107 | use_operand_p use_p = PHI_ARG_DEF_PTR_FROM_EDGE (phi, exit); | |
5108 | ||
5109 | if (USE_FROM_PTR (use_p) == tgt) | |
5110 | SET_USE (use_p, op); | |
5111 | } | |
5112 | ||
5113 | if (stmts) | |
5114 | compute_phi_arg_on_exit (exit, stmts, op); | |
5115 | ||
5116 | /* Enable removal of the statement. We cannot remove it directly, | |
5117 | since we may still need the aliasing information attached to the | |
5118 | ssa name defined by it. */ | |
5119 | name_info (data, tgt)->iv->have_use_for = false; | |
5120 | return; | |
5121 | } | |
5122 | ||
5123 | /* If the variable is going to be preserved anyway, there is nothing to | |
5124 | do. */ | |
5125 | if (name_info (data, tgt)->preserve_biv) | |
5126 | return; | |
5127 | ||
5128 | /* Otherwise we just need to compute the iv. */ | |
5129 | rewrite_use_nonlinear_expr (data, use, cand); | |
5130 | } | |
5131 | ||
5132 | /* Rewrites USE using candidate CAND. */ | |
5133 | ||
5134 | static void | |
5135 | rewrite_use (struct ivopts_data *data, | |
5136 | struct iv_use *use, struct iv_cand *cand) | |
5137 | { | |
5138 | switch (use->type) | |
5139 | { | |
5140 | case USE_NONLINEAR_EXPR: | |
5141 | rewrite_use_nonlinear_expr (data, use, cand); | |
5142 | break; | |
5143 | ||
5144 | case USE_OUTER: | |
5145 | rewrite_use_outer (data, use, cand); | |
5146 | break; | |
5147 | ||
5148 | case USE_ADDRESS: | |
5149 | rewrite_use_address (data, use, cand); | |
5150 | break; | |
5151 | ||
5152 | case USE_COMPARE: | |
5153 | rewrite_use_compare (data, use, cand); | |
5154 | break; | |
5155 | ||
5156 | default: | |
1e128c5f | 5157 | gcc_unreachable (); |
8b11a64c | 5158 | } |
f430bae8 | 5159 | update_stmt (use->stmt); |
8b11a64c ZD |
5160 | } |
5161 | ||
5162 | /* Rewrite the uses using the selected induction variables. */ | |
5163 | ||
5164 | static void | |
5165 | rewrite_uses (struct ivopts_data *data) | |
5166 | { | |
5167 | unsigned i; | |
5168 | struct iv_cand *cand; | |
5169 | struct iv_use *use; | |
5170 | ||
5171 | for (i = 0; i < n_iv_uses (data); i++) | |
5172 | { | |
5173 | use = iv_use (data, i); | |
5174 | cand = use->selected; | |
1e128c5f | 5175 | gcc_assert (cand); |
8b11a64c ZD |
5176 | |
5177 | rewrite_use (data, use, cand); | |
5178 | } | |
5179 | } | |
5180 | ||
5181 | /* Removes the ivs that are not used after rewriting. */ | |
5182 | ||
5183 | static void | |
5184 | remove_unused_ivs (struct ivopts_data *data) | |
5185 | { | |
5186 | unsigned j; | |
87c476a2 | 5187 | bitmap_iterator bi; |
8b11a64c | 5188 | |
87c476a2 | 5189 | EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, j, bi) |
8b11a64c ZD |
5190 | { |
5191 | struct version_info *info; | |
5192 | ||
5193 | info = ver_info (data, j); | |
5194 | if (info->iv | |
5195 | && !zero_p (info->iv->step) | |
5196 | && !info->inv_id | |
5197 | && !info->iv->have_use_for | |
5198 | && !info->preserve_biv) | |
5199 | remove_statement (SSA_NAME_DEF_STMT (info->iv->ssa_name), true); | |
87c476a2 | 5200 | } |
8b11a64c ZD |
5201 | } |
5202 | ||
5203 | /* Frees data allocated by the optimization of a single loop. */ | |
5204 | ||
5205 | static void | |
5206 | free_loop_data (struct ivopts_data *data) | |
5207 | { | |
5208 | unsigned i, j; | |
87c476a2 | 5209 | bitmap_iterator bi; |
8b11a64c | 5210 | |
ca4c3169 ZD |
5211 | htab_empty (data->niters); |
5212 | ||
87c476a2 | 5213 | EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi) |
8b11a64c ZD |
5214 | { |
5215 | struct version_info *info; | |
5216 | ||
5217 | info = ver_info (data, i); | |
5218 | if (info->iv) | |
5219 | free (info->iv); | |
5220 | info->iv = NULL; | |
5221 | info->has_nonlin_use = false; | |
5222 | info->preserve_biv = false; | |
5223 | info->inv_id = 0; | |
87c476a2 | 5224 | } |
8b11a64c | 5225 | bitmap_clear (data->relevant); |
b1b02be2 | 5226 | bitmap_clear (data->important_candidates); |
8b11a64c ZD |
5227 | |
5228 | for (i = 0; i < n_iv_uses (data); i++) | |
5229 | { | |
5230 | struct iv_use *use = iv_use (data, i); | |
5231 | ||
5232 | free (use->iv); | |
8bdbfff5 | 5233 | BITMAP_FREE (use->related_cands); |
8b11a64c ZD |
5234 | for (j = 0; j < use->n_map_members; j++) |
5235 | if (use->cost_map[j].depends_on) | |
8bdbfff5 | 5236 | BITMAP_FREE (use->cost_map[j].depends_on); |
8b11a64c ZD |
5237 | free (use->cost_map); |
5238 | free (use); | |
5239 | } | |
5240 | VARRAY_POP_ALL (data->iv_uses); | |
5241 | ||
5242 | for (i = 0; i < n_iv_cands (data); i++) | |
5243 | { | |
5244 | struct iv_cand *cand = iv_cand (data, i); | |
5245 | ||
5246 | if (cand->iv) | |
5247 | free (cand->iv); | |
5248 | free (cand); | |
5249 | } | |
5250 | VARRAY_POP_ALL (data->iv_candidates); | |
5251 | ||
5252 | if (data->version_info_size < num_ssa_names) | |
5253 | { | |
5254 | data->version_info_size = 2 * num_ssa_names; | |
5255 | free (data->version_info); | |
5256 | data->version_info = xcalloc (data->version_info_size, | |
5257 | sizeof (struct version_info)); | |
5258 | } | |
5259 | ||
5260 | data->max_inv_id = 0; | |
5261 | ||
5262 | for (i = 0; i < VARRAY_ACTIVE_SIZE (decl_rtl_to_reset); i++) | |
5263 | { | |
5264 | tree obj = VARRAY_GENERIC_PTR_NOGC (decl_rtl_to_reset, i); | |
5265 | ||
5266 | SET_DECL_RTL (obj, NULL_RTX); | |
5267 | } | |
5268 | VARRAY_POP_ALL (decl_rtl_to_reset); | |
5269 | } | |
5270 | ||
5271 | /* Finalizes data structures used by the iv optimization pass. LOOPS is the | |
5272 | loop tree. */ | |
5273 | ||
5274 | static void | |
5275 | tree_ssa_iv_optimize_finalize (struct loops *loops, struct ivopts_data *data) | |
5276 | { | |
5277 | unsigned i; | |
5278 | ||
5279 | for (i = 1; i < loops->num; i++) | |
5280 | if (loops->parray[i]) | |
5281 | { | |
5282 | free (loops->parray[i]->aux); | |
5283 | loops->parray[i]->aux = NULL; | |
5284 | } | |
5285 | ||
5286 | free_loop_data (data); | |
5287 | free (data->version_info); | |
8bdbfff5 NS |
5288 | BITMAP_FREE (data->relevant); |
5289 | BITMAP_FREE (data->important_candidates); | |
ca4c3169 | 5290 | htab_delete (data->niters); |
8b11a64c ZD |
5291 | |
5292 | VARRAY_FREE (decl_rtl_to_reset); | |
5293 | VARRAY_FREE (data->iv_uses); | |
5294 | VARRAY_FREE (data->iv_candidates); | |
5295 | } | |
5296 | ||
5297 | /* Optimizes the LOOP. Returns true if anything changed. */ | |
5298 | ||
5299 | static bool | |
5300 | tree_ssa_iv_optimize_loop (struct ivopts_data *data, struct loop *loop) | |
5301 | { | |
5302 | bool changed = false; | |
b1b02be2 | 5303 | struct iv_ca *iv_ca; |
8b11a64c ZD |
5304 | edge exit; |
5305 | ||
5306 | data->current_loop = loop; | |
5307 | ||
5308 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
5309 | { | |
5310 | fprintf (dump_file, "Processing loop %d\n", loop->num); | |
5311 | ||
5312 | exit = single_dom_exit (loop); | |
5313 | if (exit) | |
5314 | { | |
5315 | fprintf (dump_file, " single exit %d -> %d, exit condition ", | |
5316 | exit->src->index, exit->dest->index); | |
5317 | print_generic_expr (dump_file, last_stmt (exit->src), TDF_SLIM); | |
5318 | fprintf (dump_file, "\n"); | |
5319 | } | |
5320 | ||
5321 | fprintf (dump_file, "\n"); | |
5322 | } | |
5323 | ||
5324 | /* For each ssa name determines whether it behaves as an induction variable | |
5325 | in some loop. */ | |
5326 | if (!find_induction_variables (data)) | |
5327 | goto finish; | |
5328 | ||
5329 | /* Finds interesting uses (item 1). */ | |
5330 | find_interesting_uses (data); | |
5331 | if (n_iv_uses (data) > MAX_CONSIDERED_USES) | |
5332 | goto finish; | |
5333 | ||
5334 | /* Finds candidates for the induction variables (item 2). */ | |
5335 | find_iv_candidates (data); | |
5336 | ||
5337 | /* Calculates the costs (item 3, part 1). */ | |
5338 | determine_use_iv_costs (data); | |
5339 | determine_iv_costs (data); | |
5340 | determine_set_costs (data); | |
5341 | ||
5342 | /* Find the optimal set of induction variables (item 3, part 2). */ | |
b1b02be2 ZD |
5343 | iv_ca = find_optimal_iv_set (data); |
5344 | if (!iv_ca) | |
8b11a64c ZD |
5345 | goto finish; |
5346 | changed = true; | |
5347 | ||
5348 | /* Create the new induction variables (item 4, part 1). */ | |
b1b02be2 ZD |
5349 | create_new_ivs (data, iv_ca); |
5350 | iv_ca_free (&iv_ca); | |
8b11a64c ZD |
5351 | |
5352 | /* Rewrite the uses (item 4, part 2). */ | |
5353 | rewrite_uses (data); | |
5354 | ||
5355 | /* Remove the ivs that are unused after rewriting. */ | |
5356 | remove_unused_ivs (data); | |
5357 | ||
8b11a64c ZD |
5358 | /* We have changed the structure of induction variables; it might happen |
5359 | that definitions in the scev database refer to some of them that were | |
5360 | eliminated. */ | |
5361 | scev_reset (); | |
5362 | ||
5363 | finish: | |
5364 | free_loop_data (data); | |
5365 | ||
5366 | return changed; | |
5367 | } | |
5368 | ||
5369 | /* Main entry point. Optimizes induction variables in LOOPS. */ | |
5370 | ||
5371 | void | |
5372 | tree_ssa_iv_optimize (struct loops *loops) | |
5373 | { | |
5374 | struct loop *loop; | |
5375 | struct ivopts_data data; | |
5376 | ||
5377 | tree_ssa_iv_optimize_init (loops, &data); | |
5378 | ||
5379 | /* Optimize the loops starting with the innermost ones. */ | |
5380 | loop = loops->tree_root; | |
5381 | while (loop->inner) | |
5382 | loop = loop->inner; | |
5383 | ||
8b11a64c ZD |
5384 | /* Scan the loops, inner ones first. */ |
5385 | while (loop != loops->tree_root) | |
5386 | { | |
8679c649 JH |
5387 | if (dump_file && (dump_flags & TDF_DETAILS)) |
5388 | flow_loop_dump (loop, dump_file, NULL, 1); | |
e9472263 ZD |
5389 | |
5390 | tree_ssa_iv_optimize_loop (&data, loop); | |
8b11a64c ZD |
5391 | |
5392 | if (loop->next) | |
5393 | { | |
5394 | loop = loop->next; | |
5395 | while (loop->inner) | |
5396 | loop = loop->inner; | |
5397 | } | |
5398 | else | |
5399 | loop = loop->outer; | |
5400 | } | |
5401 | ||
0bca51f0 DN |
5402 | /* FIXME. IV opts introduces new aliases and call-clobbered |
5403 | variables, which need to be renamed. However, when we call the | |
5404 | renamer, not all statements will be scanned for operands. In | |
5405 | particular, the newly introduced aliases may appear in statements | |
5406 | that are considered "unmodified", so the renamer will not get a | |
5407 | chance to rename those operands. | |
5408 | ||
5409 | Work around this problem by forcing an operand re-scan on every | |
5410 | statement. This will not be necessary once the new operand | |
5411 | scanner is implemented. */ | |
5412 | if (need_ssa_update_p ()) | |
5413 | { | |
5414 | basic_block bb; | |
5415 | block_stmt_iterator si; | |
5416 | FOR_EACH_BB (bb) | |
5417 | for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si)) | |
5418 | update_stmt (bsi_stmt (si)); | |
5419 | ||
5420 | update_ssa (TODO_update_ssa); | |
5421 | } | |
e9472263 | 5422 | |
0bca51f0 | 5423 | rewrite_into_loop_closed_ssa (NULL); |
8b11a64c ZD |
5424 | tree_ssa_iv_optimize_finalize (loops, &data); |
5425 | } |