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) 2011-2023 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 (stream: dump_file, format: ";; loop %d: " , loop->loop_no); |
49 | if (loop->bad) |
50 | fprintf (stream: dump_file, format: "(bad) " ); |
51 | fprintf (stream: dump_file, format: "{head:%d, depth:%d, reg:%u}" , |
52 | loop->head == NULL ? -1 : loop->head->index, |
53 | loop->depth, REGNO (loop->iter_reg)); |
54 | |
55 | fprintf (stream: dump_file, format: " blocks: [ " ); |
56 | for (ix = 0; loop->blocks.iterate (ix, ptr: &b); ix++) |
57 | fprintf (stream: dump_file, format: "%d " , b->index); |
58 | fprintf (stream: dump_file, format: "] " ); |
59 | |
60 | fprintf (stream: dump_file, format: " inner loops: [ " ); |
61 | for (ix = 0; loop->loops.iterate (ix, ptr: &i); ix++) |
62 | fprintf (stream: dump_file, format: "%d " , i->loop_no); |
63 | fprintf (stream: dump_file, format: "]\n" ); |
64 | } |
65 | fprintf (stream: dump_file, format: "\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, ptr: &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, bb: 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&: 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 (regs: &set_this_insn, GET_MODE (dreg), |
137 | REGNO (dreg)); |
138 | } |
139 | |
140 | if (insn == loop->loop_end) |
141 | CLEAR_HARD_REG_BIT (set&: 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 | 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 (stream: dump_file, |
207 | format: ";; Adding forwarder block %d to loop %d and retrying\n" , |
208 | e->src->index, loop->loop_no); |
209 | loop->blocks.safe_push (obj: 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 (v&: loop->incoming, obj: e2); |
213 | loop->incoming->unordered_remove (ix: 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 (v&: loop->incoming, nelems: 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 (obj: loop->head); |
252 | |
253 | found_tail = false; |
254 | for (dwork = 0; works.iterate (ix: dwork, ptr: &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 (stream: dump_file, |
263 | format: ";; 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 (obj: 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 (obj: 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, bb: pred)) |
306 | { |
307 | if (dump_file) |
308 | fprintf (stream: dump_file, format: ";; Loop %d: incoming edge %d -> %d\n" , |
309 | loop->loop_no, pred->index, |
310 | e->dest->index); |
311 | vec_safe_push (v&: loop->incoming, obj: e); |
312 | } |
313 | } |
314 | } |
315 | |
316 | if (!process_incoming_edges (loop)) |
317 | { |
318 | if (dump_file) |
319 | fprintf (stream: dump_file, |
320 | format: ";; retrying loop %d with forwarder blocks\n" , |
321 | loop->loop_no); |
322 | if (!add_forwarder_blocks (loop)) |
323 | { |
324 | if (dump_file) |
325 | fprintf (stream: dump_file, format: ";; No forwarder blocks found\n" ); |
326 | loop->bad = true; |
327 | } |
328 | else if (!process_incoming_edges (loop)) |
329 | { |
330 | if (dump_file) |
331 | fprintf (stream: dump_file, |
332 | format: ";; 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 (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 (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 (stream: dump_file, format: ";; 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 (stream: dump_file, format: ";; 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 (nelems: 20); |
402 | loop->block_bitmap = BITMAP_ALLOC (obstack: loop_stack); |
403 | |
404 | if (dump_file) |
405 | { |
406 | fprintf (stream: dump_file, format: ";; potential loop %d ending at\n" , |
407 | loop->loop_no); |
408 | print_rtl_single (dump_file, tail); |
409 | } |
410 | |
411 | discover_loop (loop, tail_bb: bb, tail_insn: 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 (obj: other); |
434 | else if (!bitmap_intersect_compl_p (loop->block_bitmap, |
435 | other->block_bitmap)) |
436 | other->loops.safe_push (obj: loop); |
437 | else |
438 | { |
439 | if (dump_file) |
440 | fprintf (stream: dump_file, |
441 | format: ";; 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 (stream: dump_file, format: ";; 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 (stream: dump_file, format: ";; 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, ptr: &inner); ix++) |
577 | { |
578 | optimize_loop (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 | 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 (stream: dump_file, format: ";; 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 (stream: dump_file, format: ";; Find loops, first pass\n\n" ); |
632 | |
633 | loops = discover_loops (loop_stack: &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 (stream: dump_file, format: ";; Find loops, second pass\n\n" ); |
644 | |
645 | loops = discover_loops (loop_stack: &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 (stream: dump_file, format: ";; 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 | } |
667 | |