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1 | /* Code to analyze doloop loops in order for targets to perform late | |
2 | optimizations converting doloops to other forms of hardware loops. | |
3 | Copyright (C) 2011-2019 Free Software Foundation, Inc. | |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
9 | Software Foundation; either version 3, or (at your option) any later | |
10 | version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING3. If not see | |
19 | <http://www.gnu.org/licenses/>. */ | |
20 | ||
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
24 | #include "backend.h" | |
25 | #include "rtl.h" | |
26 | #include "df.h" | |
27 | #include "insn-config.h" | |
28 | #include "regs.h" | |
29 | #include "memmodel.h" | |
30 | #include "emit-rtl.h" | |
31 | #include "recog.h" | |
32 | #include "cfgrtl.h" | |
33 | #include "hw-doloop.h" | |
34 | #include "dumpfile.h" | |
35 | ||
36 | /* Dump information collected in LOOPS. */ | |
37 | static void | |
38 | dump_hwloops (hwloop_info loops) | |
39 | { | |
40 | hwloop_info loop; | |
41 | ||
42 | for (loop = loops; loop; loop = loop->next) | |
43 | { | |
44 | hwloop_info i; | |
45 | basic_block b; | |
46 | unsigned ix; | |
47 | ||
48 | fprintf (dump_file, ";; loop %d: ", loop->loop_no); | |
49 | if (loop->bad) | |
50 | fprintf (dump_file, "(bad) "); | |
51 | fprintf (dump_file, "{head:%d, depth:%d, reg:%u}", | |
52 | loop->head == NULL ? -1 : loop->head->index, | |
53 | loop->depth, REGNO (loop->iter_reg)); | |
54 | ||
55 | fprintf (dump_file, " blocks: [ "); | |
56 | for (ix = 0; loop->blocks.iterate (ix, &b); ix++) | |
57 | fprintf (dump_file, "%d ", b->index); | |
58 | fprintf (dump_file, "] "); | |
59 | ||
60 | fprintf (dump_file, " inner loops: [ "); | |
61 | for (ix = 0; loop->loops.iterate (ix, &i); ix++) | |
62 | fprintf (dump_file, "%d ", i->loop_no); | |
63 | fprintf (dump_file, "]\n"); | |
64 | } | |
65 | fprintf (dump_file, "\n"); | |
66 | } | |
67 | ||
68 | /* Return true if BB is part of LOOP. */ | |
69 | static bool | |
70 | bb_in_loop_p (hwloop_info loop, basic_block bb) | |
71 | { | |
72 | return bitmap_bit_p (loop->block_bitmap, bb->index); | |
73 | } | |
74 | ||
75 | /* Scan the blocks of LOOP (and its inferiors), and record things such as | |
76 | hard registers set, jumps out of and within the loop. */ | |
77 | static void | |
78 | scan_loop (hwloop_info loop) | |
79 | { | |
80 | unsigned ix; | |
81 | basic_block bb; | |
82 | ||
83 | if (loop->bad) | |
84 | return; | |
85 | ||
86 | if (REGNO_REG_SET_P (df_get_live_in (loop->successor), | |
87 | REGNO (loop->iter_reg))) | |
88 | loop->iter_reg_used_outside = true; | |
89 | ||
90 | for (ix = 0; loop->blocks.iterate (ix, &bb); ix++) | |
91 | { | |
92 | rtx_insn *insn; | |
93 | edge e; | |
94 | edge_iterator ei; | |
95 | ||
96 | if (bb != loop->tail) | |
97 | FOR_EACH_EDGE (e, ei, bb->succs) | |
98 | { | |
99 | if (bb_in_loop_p (loop, e->dest)) | |
100 | { | |
101 | if (!(e->flags & EDGE_FALLTHRU)) | |
102 | loop->jumps_within = true; | |
103 | } | |
104 | else | |
105 | { | |
106 | loop->jumps_outof = true; | |
107 | if (!loop->bad) | |
108 | gcc_assert (!REGNO_REG_SET_P (df_get_live_in (e->dest), | |
109 | REGNO (loop->iter_reg))); | |
110 | } | |
111 | } | |
112 | ||
113 | for (insn = BB_HEAD (bb); | |
114 | insn != NEXT_INSN (BB_END (bb)); | |
115 | insn = NEXT_INSN (insn)) | |
116 | { | |
117 | df_ref def; | |
118 | HARD_REG_SET set_this_insn; | |
119 | ||
120 | if (!NONDEBUG_INSN_P (insn)) | |
121 | continue; | |
122 | ||
123 | if (recog_memoized (insn) < 0 | |
124 | && (GET_CODE (PATTERN (insn)) == ASM_INPUT | |
125 | || asm_noperands (PATTERN (insn)) >= 0)) | |
126 | loop->has_asm = true; | |
127 | ||
128 | CLEAR_HARD_REG_SET (set_this_insn); | |
129 | FOR_EACH_INSN_DEF (def, insn) | |
130 | { | |
131 | rtx dreg = DF_REF_REG (def); | |
132 | ||
133 | if (!REG_P (dreg)) | |
134 | continue; | |
135 | ||
136 | add_to_hard_reg_set (&set_this_insn, GET_MODE (dreg), | |
137 | REGNO (dreg)); | |
138 | } | |
139 | ||
140 | if (insn == loop->loop_end) | |
141 | CLEAR_HARD_REG_BIT (set_this_insn, REGNO (loop->iter_reg)); | |
142 | else if (reg_mentioned_p (loop->iter_reg, PATTERN (insn))) | |
143 | loop->iter_reg_used = true; | |
144 | IOR_HARD_REG_SET (loop->regs_set_in_loop, set_this_insn); | |
145 | } | |
146 | } | |
147 | } | |
148 | ||
149 | /* Compute the incoming_dest and incoming_src members of LOOP by | |
150 | identifying the edges that jump into the loop. If there is more | |
151 | than one block that jumps into the loop, incoming_src will be set | |
152 | to NULL; likewise, if there is more than one block in the loop that | |
153 | is the destination of an incoming edge, incoming_dest will be NULL. | |
154 | ||
155 | Return true if either of these two fields is nonnull, false | |
156 | otherwise. */ | |
157 | static bool | |
158 | process_incoming_edges (hwloop_info loop) | |
159 | { | |
160 | edge e; | |
161 | edge_iterator ei; | |
162 | bool first = true; | |
163 | ||
164 | FOR_EACH_EDGE (e, ei, loop->incoming) | |
165 | { | |
166 | if (first) | |
167 | { | |
168 | loop->incoming_src = e->src; | |
169 | loop->incoming_dest = e->dest; | |
170 | first = false; | |
171 | } | |
172 | else | |
173 | { | |
174 | if (e->dest != loop->incoming_dest) | |
175 | loop->incoming_dest = NULL; | |
176 | if (e->src != loop->incoming_src) | |
177 | loop->incoming_src = NULL; | |
178 | } | |
179 | } | |
180 | if (loop->incoming_src == NULL && loop->incoming_dest == NULL) | |
181 | return false; | |
182 | ||
183 | return true; | |
184 | } | |
185 | ||
186 | /* Try to identify a forwarder block that jump into LOOP, and add it to | |
187 | the set of blocks in the loop, updating the vector of incoming blocks as | |
188 | well. This transformation gives a second chance to loops we couldn't | |
189 | otherwise handle by increasing the chance that we'll end up with one | |
190 | incoming_src block. | |
191 | Return true if we made a change, false otherwise. */ | |
192 | static bool | |
193 | add_forwarder_blocks (hwloop_info loop) | |
194 | { | |
195 | edge e; | |
196 | edge_iterator ei; | |
197 | ||
198 | FOR_EACH_EDGE (e, ei, loop->incoming) | |
199 | { | |
200 | if (forwarder_block_p (e->src)) | |
201 | { | |
202 | edge e2; | |
203 | edge_iterator ei2; | |
204 | ||
205 | if (dump_file) | |
206 | fprintf (dump_file, | |
207 | ";; Adding forwarder block %d to loop %d and retrying\n", | |
208 | e->src->index, loop->loop_no); | |
209 | loop->blocks.safe_push (e->src); | |
210 | bitmap_set_bit (loop->block_bitmap, e->src->index); | |
211 | FOR_EACH_EDGE (e2, ei2, e->src->preds) | |
212 | vec_safe_push (loop->incoming, e2); | |
213 | loop->incoming->unordered_remove (ei.index); | |
214 | return true; | |
215 | } | |
216 | } | |
217 | return false; | |
218 | } | |
219 | ||
220 | /* Called from reorg_loops when a potential loop end is found. LOOP is | |
221 | a newly set up structure describing the loop, it is this function's | |
222 | responsibility to fill most of it. TAIL_BB and TAIL_INSN point to the | |
223 | loop_end insn and its enclosing basic block. REG is the loop counter | |
224 | register. | |
225 | For our purposes, a loop is defined by the set of blocks reachable from | |
226 | the loop head in which the loop counter register is live. This matches | |
227 | the expected use; targets that call into this code usually replace the | |
228 | loop counter with a different special register. */ | |
229 | static void | |
230 | discover_loop (hwloop_info loop, basic_block tail_bb, rtx_insn *tail_insn, rtx reg) | |
231 | { | |
232 | bool found_tail; | |
233 | unsigned dwork = 0; | |
234 | basic_block bb; | |
235 | ||
236 | loop->tail = tail_bb; | |
237 | loop->loop_end = tail_insn; | |
238 | loop->iter_reg = reg; | |
239 | vec_alloc (loop->incoming, 2); | |
240 | loop->start_label = as_a <rtx_insn *> (JUMP_LABEL (tail_insn)); | |
241 | ||
242 | if (EDGE_COUNT (tail_bb->succs) != 2) | |
243 | { | |
244 | loop->bad = true; | |
245 | return; | |
246 | } | |
247 | loop->head = BRANCH_EDGE (tail_bb)->dest; | |
248 | loop->successor = FALLTHRU_EDGE (tail_bb)->dest; | |
249 | ||
250 | auto_vec<basic_block, 20> works; | |
251 | works.safe_push (loop->head); | |
252 | ||
253 | found_tail = false; | |
254 | for (dwork = 0; works.iterate (dwork, &bb); dwork++) | |
255 | { | |
256 | edge e; | |
257 | edge_iterator ei; | |
258 | if (bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
259 | { | |
260 | /* We've reached the exit block. The loop must be bad. */ | |
261 | if (dump_file) | |
262 | fprintf (dump_file, | |
263 | ";; Loop is bad - reached exit block while scanning\n"); | |
264 | loop->bad = true; | |
265 | break; | |
266 | } | |
267 | ||
268 | if (bitmap_bit_p (loop->block_bitmap, bb->index)) | |
269 | continue; | |
270 | ||
271 | /* We've not seen this block before. Add it to the loop's | |
272 | list and then add each successor to the work list. */ | |
273 | ||
274 | loop->blocks.safe_push (bb); | |
275 | bitmap_set_bit (loop->block_bitmap, bb->index); | |
276 | ||
277 | if (bb == tail_bb) | |
278 | found_tail = true; | |
279 | else | |
280 | { | |
281 | FOR_EACH_EDGE (e, ei, bb->succs) | |
282 | { | |
283 | basic_block succ = EDGE_SUCC (bb, ei.index)->dest; | |
284 | if (REGNO_REG_SET_P (df_get_live_in (succ), | |
285 | REGNO (loop->iter_reg))) | |
286 | works.safe_push (succ); | |
287 | } | |
288 | } | |
289 | } | |
290 | ||
291 | if (!found_tail) | |
292 | loop->bad = true; | |
293 | ||
294 | /* Find the predecessor, and make sure nothing else jumps into this loop. */ | |
295 | if (!loop->bad) | |
296 | { | |
297 | FOR_EACH_VEC_ELT (loop->blocks, dwork, bb) | |
298 | { | |
299 | edge e; | |
300 | edge_iterator ei; | |
301 | FOR_EACH_EDGE (e, ei, bb->preds) | |
302 | { | |
303 | basic_block pred = e->src; | |
304 | ||
305 | if (!bb_in_loop_p (loop, pred)) | |
306 | { | |
307 | if (dump_file) | |
308 | fprintf (dump_file, ";; Loop %d: incoming edge %d -> %d\n", | |
309 | loop->loop_no, pred->index, | |
310 | e->dest->index); | |
311 | vec_safe_push (loop->incoming, e); | |
312 | } | |
313 | } | |
314 | } | |
315 | ||
316 | if (!process_incoming_edges (loop)) | |
317 | { | |
318 | if (dump_file) | |
319 | fprintf (dump_file, | |
320 | ";; retrying loop %d with forwarder blocks\n", | |
321 | loop->loop_no); | |
322 | if (!add_forwarder_blocks (loop)) | |
323 | { | |
324 | if (dump_file) | |
325 | fprintf (dump_file, ";; No forwarder blocks found\n"); | |
326 | loop->bad = true; | |
327 | } | |
328 | else if (!process_incoming_edges (loop)) | |
329 | { | |
330 | if (dump_file) | |
331 | fprintf (dump_file, | |
332 | ";; can't find suitable entry for loop %d\n", | |
333 | loop->loop_no); | |
334 | } | |
335 | } | |
336 | } | |
337 | } | |
338 | ||
339 | /* Analyze the structure of the loops in the current function. Use | |
340 | LOOP_STACK for bitmap allocations. Returns all the valid candidates for | |
341 | hardware loops found in this function. HOOKS is the argument | |
342 | passed to reorg_loops, used here to find the iteration registers | |
343 | from a loop_end pattern. */ | |
344 | static hwloop_info | |
345 | discover_loops (bitmap_obstack *loop_stack, struct hw_doloop_hooks *hooks) | |
346 | { | |
347 | hwloop_info loops = NULL; | |
348 | hwloop_info loop; | |
349 | basic_block bb; | |
350 | int nloops = 0; | |
351 | ||
352 | /* Find all the possible loop tails. This means searching for every | |
353 | loop_end instruction. For each one found, create a hwloop_info | |
354 | structure and add the head block to the work list. */ | |
355 | FOR_EACH_BB_FN (bb, cfun) | |
356 | { | |
357 | rtx_insn *tail = BB_END (bb); | |
358 | rtx_insn *insn; | |
359 | rtx reg; | |
360 | ||
361 | while (tail && NOTE_P (tail) && tail != BB_HEAD (bb)) | |
362 | tail = PREV_INSN (tail); | |
363 | ||
364 | if (tail == NULL_RTX) | |
365 | continue; | |
366 | ||
367 | if (!JUMP_P (tail)) | |
368 | continue; | |
369 | reg = hooks->end_pattern_reg (tail); | |
370 | if (reg == NULL_RTX) | |
371 | continue; | |
372 | ||
373 | /* A possible loop end */ | |
374 | ||
375 | /* There's a degenerate case we can handle - an empty loop consisting | |
376 | of only a back branch. Handle that by deleting the branch. */ | |
377 | insn = JUMP_LABEL_AS_INSN (tail); | |
378 | while (insn && !NONDEBUG_INSN_P (insn)) | |
379 | insn = NEXT_INSN (insn); | |
380 | if (insn == tail) | |
381 | { | |
382 | basic_block succ = FALLTHRU_EDGE (bb)->dest; | |
383 | if (dump_file) | |
384 | { | |
385 | fprintf (dump_file, ";; degenerate loop ending at\n"); | |
386 | print_rtl_single (dump_file, tail); | |
387 | } | |
388 | if (!REGNO_REG_SET_P (df_get_live_in (succ), REGNO (reg))) | |
389 | { | |
390 | if (dump_file) | |
391 | fprintf (dump_file, ";; deleting it\n"); | |
392 | delete_insn_and_edges (tail); | |
393 | continue; | |
394 | } | |
395 | } | |
396 | ||
397 | loop = XCNEW (struct hwloop_info_d); | |
398 | loop->next = loops; | |
399 | loops = loop; | |
400 | loop->loop_no = nloops++; | |
401 | loop->blocks.create (20); | |
402 | loop->block_bitmap = BITMAP_ALLOC (loop_stack); | |
403 | ||
404 | if (dump_file) | |
405 | { | |
406 | fprintf (dump_file, ";; potential loop %d ending at\n", | |
407 | loop->loop_no); | |
408 | print_rtl_single (dump_file, tail); | |
409 | } | |
410 | ||
411 | discover_loop (loop, bb, tail, reg); | |
412 | } | |
413 | ||
414 | /* Compute loop nestings. Given two loops A and B, either the sets | |
415 | of their blocks don't intersect at all, or one is the subset of | |
416 | the other, or the blocks don't form a good nesting structure. */ | |
417 | for (loop = loops; loop; loop = loop->next) | |
418 | { | |
419 | hwloop_info other; | |
420 | ||
421 | if (loop->bad) | |
422 | continue; | |
423 | ||
424 | for (other = loops; other; other = other->next) | |
425 | { | |
426 | if (other->bad) | |
427 | continue; | |
428 | ||
429 | if (!bitmap_intersect_p (other->block_bitmap, loop->block_bitmap)) | |
430 | continue; | |
431 | if (!bitmap_intersect_compl_p (other->block_bitmap, | |
432 | loop->block_bitmap)) | |
433 | loop->loops.safe_push (other); | |
434 | else if (!bitmap_intersect_compl_p (loop->block_bitmap, | |
435 | other->block_bitmap)) | |
436 | other->loops.safe_push (loop); | |
437 | else | |
438 | { | |
439 | if (dump_file) | |
440 | fprintf (dump_file, | |
441 | ";; can't find suitable nesting for loops %d and %d\n", | |
442 | loop->loop_no, other->loop_no); | |
443 | loop->bad = other->bad = true; | |
444 | } | |
445 | } | |
446 | } | |
447 | ||
448 | if (dump_file) | |
449 | dump_hwloops (loops); | |
450 | ||
451 | return loops; | |
452 | } | |
453 | ||
454 | /* Free up the loop structures in LOOPS. */ | |
455 | static void | |
456 | free_loops (hwloop_info loops) | |
457 | { | |
458 | while (loops) | |
459 | { | |
460 | hwloop_info loop = loops; | |
461 | loops = loop->next; | |
462 | loop->loops.release (); | |
463 | loop->blocks.release (); | |
464 | BITMAP_FREE (loop->block_bitmap); | |
465 | XDELETE (loop); | |
466 | } | |
467 | } | |
468 | ||
469 | #define BB_AUX_INDEX(BB) ((intptr_t) (BB)->aux) | |
470 | ||
471 | /* Initialize the aux fields to give ascending indices to basic blocks. */ | |
472 | static void | |
473 | set_bb_indices (void) | |
474 | { | |
475 | basic_block bb; | |
476 | intptr_t index; | |
477 | ||
478 | index = 0; | |
479 | FOR_EACH_BB_FN (bb, cfun) | |
480 | bb->aux = (void *) index++; | |
481 | } | |
482 | ||
483 | /* The taken-branch edge from the loop end can actually go forward. | |
484 | If the target's hardware loop support requires that the loop end be | |
485 | after the loop start, try to reorder a loop's basic blocks when we | |
486 | find such a case. | |
487 | This is not very aggressive; it only moves at most one block. It | |
488 | does not introduce new branches into loops; it may remove them, or | |
489 | it may switch fallthru/jump edges. */ | |
490 | static void | |
491 | reorder_loops (hwloop_info loops) | |
492 | { | |
493 | basic_block bb; | |
494 | hwloop_info loop; | |
495 | ||
496 | cfg_layout_initialize (0); | |
497 | ||
498 | set_bb_indices (); | |
499 | ||
500 | for (loop = loops; loop; loop = loop->next) | |
501 | { | |
502 | edge e; | |
503 | edge_iterator ei; | |
504 | ||
505 | if (loop->bad) | |
506 | continue; | |
507 | ||
508 | if (BB_AUX_INDEX (loop->head) <= BB_AUX_INDEX (loop->tail)) | |
509 | continue; | |
510 | ||
511 | FOR_EACH_EDGE (e, ei, loop->head->succs) | |
512 | { | |
513 | if (bitmap_bit_p (loop->block_bitmap, e->dest->index) | |
514 | && BB_AUX_INDEX (e->dest) < BB_AUX_INDEX (loop->tail)) | |
515 | { | |
516 | basic_block start_bb = e->dest; | |
517 | basic_block start_prev_bb = start_bb->prev_bb; | |
518 | ||
519 | if (dump_file) | |
520 | fprintf (dump_file, ";; Moving block %d before block %d\n", | |
521 | loop->head->index, start_bb->index); | |
522 | loop->head->prev_bb->next_bb = loop->head->next_bb; | |
523 | loop->head->next_bb->prev_bb = loop->head->prev_bb; | |
524 | ||
525 | loop->head->prev_bb = start_prev_bb; | |
526 | loop->head->next_bb = start_bb; | |
527 | start_prev_bb->next_bb = start_bb->prev_bb = loop->head; | |
528 | ||
529 | set_bb_indices (); | |
530 | break; | |
531 | } | |
532 | } | |
533 | loops = loops->next; | |
534 | } | |
535 | ||
536 | FOR_EACH_BB_FN (bb, cfun) | |
537 | { | |
538 | if (bb->next_bb != EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
539 | bb->aux = bb->next_bb; | |
540 | else | |
541 | bb->aux = NULL; | |
542 | } | |
543 | cfg_layout_finalize (); | |
544 | clear_aux_for_blocks (); | |
545 | df_analyze (); | |
546 | } | |
547 | ||
548 | /* Call the OPT function for LOOP and all of its sub-loops. This is | |
549 | done in a depth-first search; innermost loops are visited first. | |
550 | OPTIMIZE and FAIL are the functions passed to reorg_loops by the | |
551 | target's reorg pass. */ | |
552 | static void | |
553 | optimize_loop (hwloop_info loop, struct hw_doloop_hooks *hooks) | |
554 | { | |
555 | int ix; | |
556 | hwloop_info inner; | |
557 | int inner_depth = 0; | |
558 | ||
559 | if (loop->visited) | |
560 | return; | |
561 | ||
562 | loop->visited = 1; | |
563 | ||
564 | if (loop->bad) | |
565 | { | |
566 | if (dump_file) | |
567 | fprintf (dump_file, ";; loop %d bad when found\n", loop->loop_no); | |
568 | goto bad_loop; | |
569 | } | |
570 | ||
571 | /* Every loop contains in its list of inner loops every loop nested inside | |
572 | it, even if there are intermediate loops. This works because we're doing | |
573 | a depth-first search here and never visit a loop more than once. | |
574 | Recursion depth is effectively limited by the number of available | |
575 | hardware registers. */ | |
576 | for (ix = 0; loop->loops.iterate (ix, &inner); ix++) | |
577 | { | |
578 | optimize_loop (inner, hooks); | |
579 | ||
580 | if (!inner->bad && inner_depth < inner->depth) | |
581 | inner_depth = inner->depth; | |
582 | /* The set of registers may be changed while optimizing the inner | |
583 | loop. */ | |
584 | IOR_HARD_REG_SET (loop->regs_set_in_loop, inner->regs_set_in_loop); | |
585 | } | |
586 | ||
587 | loop->depth = inner_depth + 1; | |
588 | ||
589 | if (hooks->opt (loop)) | |
590 | return; | |
591 | ||
592 | bad_loop: | |
593 | if (dump_file) | |
594 | fprintf (dump_file, ";; loop %d is bad\n", loop->loop_no); | |
595 | ||
596 | loop->bad = true; | |
597 | hooks->fail (loop); | |
598 | } | |
599 | ||
600 | /* This function can be used from a port's machine_dependent_reorg to | |
601 | find and analyze loops that end in loop_end instructions. It uses | |
602 | a set of function pointers in HOOKS to call back into the | |
603 | target-specific functions to perform the actual machine-specific | |
604 | transformations. | |
605 | ||
606 | Such transformations typically involve additional set-up | |
607 | instructions before the loop, to define loop bounds or set up a | |
608 | special loop counter register. | |
609 | ||
610 | DO_REORDER should be set to true if we should try to use the | |
611 | reorder_loops function to ensure the loop end occurs after the loop | |
612 | start. This is for use by targets where the loop hardware requires | |
613 | this condition. | |
614 | ||
615 | HOOKS is used to pass in target specific hooks; see | |
616 | hw-doloop.h. */ | |
617 | void | |
618 | reorg_loops (bool do_reorder, struct hw_doloop_hooks *hooks) | |
619 | { | |
620 | hwloop_info loops = NULL; | |
621 | hwloop_info loop; | |
622 | bitmap_obstack loop_stack; | |
623 | ||
624 | df_live_add_problem (); | |
625 | df_live_set_all_dirty (); | |
626 | df_analyze (); | |
627 | ||
628 | bitmap_obstack_initialize (&loop_stack); | |
629 | ||
630 | if (dump_file) | |
631 | fprintf (dump_file, ";; Find loops, first pass\n\n"); | |
632 | ||
633 | loops = discover_loops (&loop_stack, hooks); | |
634 | ||
635 | /* We can't enter cfglayout mode anymore if basic block partitioning | |
636 | already happened. */ | |
637 | if (do_reorder && !crtl->has_bb_partition) | |
638 | { | |
639 | reorder_loops (loops); | |
640 | free_loops (loops); | |
641 | ||
642 | if (dump_file) | |
643 | fprintf (dump_file, ";; Find loops, second pass\n\n"); | |
644 | ||
645 | loops = discover_loops (&loop_stack, hooks); | |
646 | } | |
647 | ||
648 | for (loop = loops; loop; loop = loop->next) | |
649 | scan_loop (loop); | |
650 | ||
651 | /* Now apply the optimizations. */ | |
652 | for (loop = loops; loop; loop = loop->next) | |
653 | optimize_loop (loop, hooks); | |
654 | ||
655 | if (dump_file) | |
656 | { | |
657 | fprintf (dump_file, ";; After hardware loops optimization:\n\n"); | |
658 | dump_hwloops (loops); | |
659 | } | |
660 | ||
661 | free_loops (loops); | |
662 | bitmap_obstack_release (&loop_stack); | |
663 | ||
664 | if (dump_file) | |
665 | print_rtl (dump_file, get_insns ()); | |
666 | } |