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9ee634e3 | 1 | /* Hooks for cfg representation specific functions. |
283334f0 | 2 | Copyright (C) 2003, 2004 Free Software Foundation, Inc. |
9ee634e3 JH |
3 | Contributed by Sebastian Pop <s.pop@laposte.net> |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING. If not, write to | |
19 | the Free Software Foundation, 59 Temple Place - Suite 330, | |
20 | Boston, MA 02111-1307, USA. */ | |
21 | ||
22 | #include "config.h" | |
23 | #include "system.h" | |
24 | #include "coretypes.h" | |
25 | #include "tm.h" | |
26 | #include "tree.h" | |
27 | #include "rtl.h" | |
28 | #include "basic-block.h" | |
6de9cd9a | 29 | #include "tree-flow.h" |
f470c378 ZD |
30 | #include "timevar.h" |
31 | #include "toplev.h" | |
9ee634e3 JH |
32 | |
33 | /* A pointer to one of the hooks containers. */ | |
f470c378 | 34 | static struct cfg_hooks *cfg_hooks; |
9ee634e3 JH |
35 | |
36 | /* Initialization of functions specific to the rtl IR. */ | |
d329e058 AJ |
37 | void |
38 | rtl_register_cfg_hooks (void) | |
9ee634e3 JH |
39 | { |
40 | cfg_hooks = &rtl_cfg_hooks; | |
41 | } | |
42 | ||
43 | /* Initialization of functions specific to the rtl IR. */ | |
d329e058 AJ |
44 | void |
45 | cfg_layout_rtl_register_cfg_hooks (void) | |
9ee634e3 JH |
46 | { |
47 | cfg_hooks = &cfg_layout_rtl_cfg_hooks; | |
48 | } | |
f470c378 | 49 | |
6de9cd9a DN |
50 | /* Initialization of functions specific to the tree IR. */ |
51 | ||
52 | void | |
53 | tree_register_cfg_hooks (void) | |
54 | { | |
55 | cfg_hooks = &tree_cfg_hooks; | |
56 | } | |
57 | ||
58 | /* Returns current ir type (rtl = 0, trees = 1). */ | |
59 | ||
60 | int | |
61 | ir_type (void) | |
62 | { | |
63 | return cfg_hooks == &tree_cfg_hooks ? 1 : 0; | |
64 | } | |
65 | ||
f470c378 ZD |
66 | /* Verify the CFG consistency. |
67 | ||
68 | Currently it does following: checks edge and basic block list correctness | |
69 | and calls into IL dependent checking then. */ | |
70 | ||
71 | void | |
72 | verify_flow_info (void) | |
73 | { | |
74 | size_t *edge_checksum; | |
75 | int num_bb_notes, err = 0; | |
76 | basic_block bb, last_bb_seen; | |
77 | basic_block *last_visited; | |
78 | ||
79 | timevar_push (TV_CFG_VERIFY); | |
80 | last_visited = xcalloc (last_basic_block + 2, sizeof (basic_block)); | |
81 | edge_checksum = xcalloc (last_basic_block + 2, sizeof (size_t)); | |
82 | ||
83 | /* Check bb chain & numbers. */ | |
84 | last_bb_seen = ENTRY_BLOCK_PTR; | |
85 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb, NULL, next_bb) | |
86 | { | |
87 | if (bb != EXIT_BLOCK_PTR | |
88 | && bb != BASIC_BLOCK (bb->index)) | |
89 | { | |
90 | error ("bb %d on wrong place", bb->index); | |
91 | err = 1; | |
92 | } | |
93 | ||
94 | if (bb->prev_bb != last_bb_seen) | |
95 | { | |
96 | error ("prev_bb of %d should be %d, not %d", | |
97 | bb->index, last_bb_seen->index, bb->prev_bb->index); | |
98 | err = 1; | |
99 | } | |
100 | ||
101 | last_bb_seen = bb; | |
102 | } | |
103 | ||
104 | /* Now check the basic blocks (boundaries etc.) */ | |
105 | FOR_EACH_BB_REVERSE (bb) | |
106 | { | |
107 | int n_fallthru = 0; | |
108 | edge e; | |
109 | ||
110 | if (bb->count < 0) | |
111 | { | |
112 | error ("verify_flow_info: Wrong count of block %i %i", | |
113 | bb->index, (int)bb->count); | |
114 | err = 1; | |
115 | } | |
116 | if (bb->frequency < 0) | |
117 | { | |
118 | error ("verify_flow_info: Wrong frequency of block %i %i", | |
119 | bb->index, bb->frequency); | |
120 | err = 1; | |
121 | } | |
122 | for (e = bb->succ; e; e = e->succ_next) | |
123 | { | |
124 | if (last_visited [e->dest->index + 2] == bb) | |
125 | { | |
126 | error ("verify_flow_info: Duplicate edge %i->%i", | |
127 | e->src->index, e->dest->index); | |
128 | err = 1; | |
129 | } | |
130 | if (e->probability < 0 || e->probability > REG_BR_PROB_BASE) | |
131 | { | |
132 | error ("verify_flow_info: Wrong probability of edge %i->%i %i", | |
133 | e->src->index, e->dest->index, e->probability); | |
134 | err = 1; | |
135 | } | |
136 | if (e->count < 0) | |
137 | { | |
138 | error ("verify_flow_info: Wrong count of edge %i->%i %i", | |
139 | e->src->index, e->dest->index, (int)e->count); | |
140 | err = 1; | |
141 | } | |
142 | ||
143 | last_visited [e->dest->index + 2] = bb; | |
144 | ||
145 | if (e->flags & EDGE_FALLTHRU) | |
146 | n_fallthru++; | |
147 | ||
148 | if (e->src != bb) | |
149 | { | |
150 | error ("verify_flow_info: Basic block %d succ edge is corrupted", | |
151 | bb->index); | |
152 | fprintf (stderr, "Predecessor: "); | |
153 | dump_edge_info (stderr, e, 0); | |
154 | fprintf (stderr, "\nSuccessor: "); | |
155 | dump_edge_info (stderr, e, 1); | |
156 | fprintf (stderr, "\n"); | |
157 | err = 1; | |
158 | } | |
159 | ||
160 | edge_checksum[e->dest->index + 2] += (size_t) e; | |
161 | } | |
162 | if (n_fallthru > 1) | |
163 | { | |
164 | error ("Wrong amount of branch edges after unconditional jump %i", bb->index); | |
165 | err = 1; | |
166 | } | |
167 | ||
168 | for (e = bb->pred; e; e = e->pred_next) | |
169 | { | |
170 | if (e->dest != bb) | |
171 | { | |
172 | error ("basic block %d pred edge is corrupted", bb->index); | |
173 | fputs ("Predecessor: ", stderr); | |
174 | dump_edge_info (stderr, e, 0); | |
175 | fputs ("\nSuccessor: ", stderr); | |
176 | dump_edge_info (stderr, e, 1); | |
177 | fputc ('\n', stderr); | |
178 | err = 1; | |
179 | } | |
180 | edge_checksum[e->dest->index + 2] -= (size_t) e; | |
181 | } | |
182 | } | |
183 | ||
184 | /* Complete edge checksumming for ENTRY and EXIT. */ | |
185 | { | |
186 | edge e; | |
187 | ||
188 | for (e = ENTRY_BLOCK_PTR->succ; e ; e = e->succ_next) | |
189 | edge_checksum[e->dest->index + 2] += (size_t) e; | |
190 | ||
191 | for (e = EXIT_BLOCK_PTR->pred; e ; e = e->pred_next) | |
192 | edge_checksum[e->dest->index + 2] -= (size_t) e; | |
193 | } | |
194 | ||
195 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb) | |
196 | if (edge_checksum[bb->index + 2]) | |
197 | { | |
198 | error ("basic block %i edge lists are corrupted", bb->index); | |
199 | err = 1; | |
200 | } | |
201 | ||
202 | num_bb_notes = 0; | |
203 | last_bb_seen = ENTRY_BLOCK_PTR; | |
204 | ||
205 | /* Clean up. */ | |
206 | free (last_visited); | |
207 | free (edge_checksum); | |
208 | ||
209 | if (cfg_hooks->verify_flow_info) | |
210 | err |= cfg_hooks->verify_flow_info (); | |
211 | if (err) | |
212 | internal_error ("verify_flow_info failed"); | |
213 | timevar_pop (TV_CFG_VERIFY); | |
214 | } | |
215 | ||
216 | /* Print out one basic block. This function takes care of the purely | |
217 | graph related information. The cfg hook for the active representation | |
218 | should dump representation-specific information. */ | |
219 | ||
220 | void | |
221 | dump_bb (basic_block bb, FILE *outf, int indent) | |
222 | { | |
223 | edge e; | |
224 | char *s_indent; | |
225 | ||
400e39e3 KH |
226 | s_indent = alloca ((size_t) indent + 1); |
227 | memset (s_indent, ' ', (size_t) indent); | |
f470c378 ZD |
228 | s_indent[indent] = '\0'; |
229 | ||
230 | fprintf (outf, ";;%s basic block %d, loop depth %d, count ", | |
231 | s_indent, bb->index, bb->loop_depth); | |
232 | fprintf (outf, HOST_WIDEST_INT_PRINT_DEC, (HOST_WIDEST_INT) bb->count); | |
233 | putc ('\n', outf); | |
234 | ||
235 | fprintf (outf, ";;%s prev block ", s_indent); | |
236 | if (bb->prev_bb) | |
237 | fprintf (outf, "%d, ", bb->prev_bb->index); | |
238 | else | |
239 | fprintf (outf, "(nil), "); | |
240 | fprintf (outf, "next block "); | |
241 | if (bb->next_bb) | |
242 | fprintf (outf, "%d", bb->next_bb->index); | |
243 | else | |
244 | fprintf (outf, "(nil)"); | |
245 | putc ('\n', outf); | |
246 | ||
247 | fprintf (outf, ";;%s pred: ", s_indent); | |
248 | for (e = bb->pred; e; e = e->pred_next) | |
249 | dump_edge_info (outf, e, 0); | |
250 | putc ('\n', outf); | |
251 | ||
252 | fprintf (outf, ";;%s succ: ", s_indent); | |
253 | for (e = bb->succ; e; e = e->succ_next) | |
254 | dump_edge_info (outf, e, 1); | |
255 | putc ('\n', outf); | |
256 | ||
257 | if (cfg_hooks->dump_bb) | |
258 | cfg_hooks->dump_bb (bb, outf, indent); | |
259 | } | |
260 | ||
261 | /* Redirect edge E to the given basic block DEST and update underlying program | |
262 | representation. Returns edge representing redirected branch (that may not | |
263 | be equivalent to E in the case of duplicate edges being removed) or NULL | |
264 | if edge is not easily redirectable for whatever reason. */ | |
265 | ||
6de9cd9a | 266 | edge |
f470c378 ZD |
267 | redirect_edge_and_branch (edge e, basic_block dest) |
268 | { | |
6de9cd9a | 269 | edge ret; |
f470c378 ZD |
270 | |
271 | if (!cfg_hooks->redirect_edge_and_branch) | |
272 | internal_error ("%s does not support redirect_edge_and_branch.", | |
273 | cfg_hooks->name); | |
274 | ||
275 | ret = cfg_hooks->redirect_edge_and_branch (e, dest); | |
276 | ||
277 | return ret; | |
278 | } | |
279 | ||
280 | /* Redirect the edge E to basic block DEST even if it requires creating | |
281 | of a new basic block; then it returns the newly created basic block. | |
282 | Aborts when redirection is impossible. */ | |
283 | ||
284 | basic_block | |
285 | redirect_edge_and_branch_force (edge e, basic_block dest) | |
286 | { | |
287 | basic_block ret; | |
288 | ||
289 | if (!cfg_hooks->redirect_edge_and_branch_force) | |
290 | internal_error ("%s does not support redirect_edge_and_branch_force.", | |
291 | cfg_hooks->name); | |
292 | ||
293 | ret = cfg_hooks->redirect_edge_and_branch_force (e, dest); | |
294 | ||
295 | return ret; | |
296 | } | |
297 | ||
298 | /* Splits basic block BB after the specified instruction I (but at least after | |
299 | the labels). If I is NULL, splits just after labels. The newly created edge | |
300 | is returned. The new basic block is created just after the old one. */ | |
301 | ||
302 | edge | |
303 | split_block (basic_block bb, void *i) | |
304 | { | |
305 | basic_block new_bb; | |
306 | ||
307 | if (!cfg_hooks->split_block) | |
308 | internal_error ("%s does not support split_block.", cfg_hooks->name); | |
309 | ||
310 | new_bb = cfg_hooks->split_block (bb, i); | |
311 | if (!new_bb) | |
312 | return NULL; | |
313 | ||
314 | new_bb->count = bb->count; | |
315 | new_bb->frequency = bb->frequency; | |
316 | new_bb->loop_depth = bb->loop_depth; | |
317 | ||
318 | if (dom_computed[CDI_DOMINATORS] >= DOM_CONS_OK) | |
319 | { | |
320 | redirect_immediate_dominators (CDI_DOMINATORS, bb, new_bb); | |
321 | set_immediate_dominator (CDI_DOMINATORS, new_bb, bb); | |
322 | } | |
323 | ||
649b2789 | 324 | return make_single_succ_edge (bb, new_bb, EDGE_FALLTHRU); |
f470c378 ZD |
325 | } |
326 | ||
327 | /* Splits block BB just after labels. The newly created edge is returned. */ | |
328 | ||
329 | edge | |
330 | split_block_after_labels (basic_block bb) | |
331 | { | |
332 | return split_block (bb, NULL); | |
333 | } | |
334 | ||
321440fd | 335 | /* Moves block BB immediately after block AFTER. Returns false if the |
f470c378 ZD |
336 | movement was impossible. */ |
337 | ||
338 | bool | |
339 | move_block_after (basic_block bb, basic_block after) | |
340 | { | |
341 | bool ret; | |
342 | ||
343 | if (!cfg_hooks->move_block_after) | |
344 | internal_error ("%s does not support move_block_after.", cfg_hooks->name); | |
345 | ||
346 | ret = cfg_hooks->move_block_after (bb, after); | |
347 | ||
348 | return ret; | |
349 | } | |
350 | ||
351 | /* Deletes the basic block BB. */ | |
352 | ||
353 | void | |
354 | delete_basic_block (basic_block bb) | |
355 | { | |
356 | if (!cfg_hooks->delete_basic_block) | |
357 | internal_error ("%s does not support delete_basic_block.", cfg_hooks->name); | |
358 | ||
359 | cfg_hooks->delete_basic_block (bb); | |
360 | ||
361 | /* Remove the edges into and out of this block. Note that there may | |
362 | indeed be edges in, if we are removing an unreachable loop. */ | |
363 | while (bb->pred != NULL) | |
364 | remove_edge (bb->pred); | |
365 | while (bb->succ != NULL) | |
366 | remove_edge (bb->succ); | |
367 | ||
368 | bb->pred = NULL; | |
369 | bb->succ = NULL; | |
370 | ||
371 | if (dom_computed[CDI_DOMINATORS]) | |
372 | delete_from_dominance_info (CDI_DOMINATORS, bb); | |
373 | if (dom_computed[CDI_POST_DOMINATORS]) | |
374 | delete_from_dominance_info (CDI_POST_DOMINATORS, bb); | |
375 | ||
376 | /* Remove the basic block from the array. */ | |
377 | expunge_block (bb); | |
378 | } | |
379 | ||
380 | /* Splits edge E and returns the newly created basic block. */ | |
381 | ||
382 | basic_block | |
383 | split_edge (edge e) | |
384 | { | |
385 | basic_block ret; | |
386 | gcov_type count = e->count; | |
387 | int freq = EDGE_FREQUENCY (e); | |
017b3258 | 388 | edge f; |
f470c378 ZD |
389 | |
390 | if (!cfg_hooks->split_edge) | |
391 | internal_error ("%s does not support split_edge.", cfg_hooks->name); | |
392 | ||
393 | ret = cfg_hooks->split_edge (e); | |
394 | ret->count = count; | |
395 | ret->frequency = freq; | |
396 | ret->succ->probability = REG_BR_PROB_BASE; | |
397 | ret->succ->count = count; | |
398 | ||
399 | if (dom_computed[CDI_DOMINATORS]) | |
400 | set_immediate_dominator (CDI_DOMINATORS, ret, ret->pred->src); | |
401 | ||
402 | if (dom_computed[CDI_DOMINATORS] >= DOM_NO_FAST_QUERY) | |
017b3258 ZD |
403 | { |
404 | /* There are two cases: | |
405 | ||
406 | If the immediate dominator of e->dest is not e->src, it | |
407 | remains unchanged. | |
408 | ||
409 | If immediate dominator of e->dest is e->src, it may become | |
410 | ret, provided that all other predecessors of e->dest are | |
411 | dominated by e->dest. */ | |
412 | ||
413 | if (get_immediate_dominator (CDI_DOMINATORS, ret->succ->dest) | |
414 | == ret->pred->src) | |
415 | { | |
416 | for (f = ret->succ->dest->pred; f; f = f->pred_next) | |
417 | { | |
418 | if (f == ret->succ) | |
419 | continue; | |
420 | ||
421 | if (!dominated_by_p (CDI_DOMINATORS, f->src, | |
422 | ret->succ->dest)) | |
423 | break; | |
424 | } | |
425 | ||
426 | if (!f) | |
427 | set_immediate_dominator (CDI_DOMINATORS, ret->succ->dest, ret); | |
428 | } | |
429 | }; | |
f470c378 ZD |
430 | |
431 | return ret; | |
432 | } | |
433 | ||
434 | /* Creates a new basic block just after the basic block AFTER. | |
435 | HEAD and END are the first and the last statement belonging | |
436 | to the block. If both are NULL, an empty block is created. */ | |
437 | ||
438 | basic_block | |
439 | create_basic_block (void *head, void *end, basic_block after) | |
440 | { | |
441 | basic_block ret; | |
442 | ||
443 | if (!cfg_hooks->create_basic_block) | |
444 | internal_error ("%s does not support create_basic_block.", cfg_hooks->name); | |
445 | ||
446 | ret = cfg_hooks->create_basic_block (head, end, after); | |
447 | ||
448 | if (dom_computed[CDI_DOMINATORS]) | |
449 | add_to_dominance_info (CDI_DOMINATORS, ret); | |
450 | if (dom_computed[CDI_POST_DOMINATORS]) | |
451 | add_to_dominance_info (CDI_POST_DOMINATORS, ret); | |
452 | ||
453 | return ret; | |
454 | } | |
455 | ||
456 | /* Creates an empty basic block just after basic block AFTER. */ | |
457 | ||
458 | basic_block | |
459 | create_empty_bb (basic_block after) | |
460 | { | |
461 | return create_basic_block (NULL, NULL, after); | |
462 | } | |
463 | ||
464 | /* Checks whether we may merge blocks BB1 and BB2. */ | |
465 | ||
466 | bool | |
467 | can_merge_blocks_p (basic_block bb1, basic_block bb2) | |
468 | { | |
469 | bool ret; | |
470 | ||
471 | if (!cfg_hooks->can_merge_blocks_p) | |
472 | internal_error ("%s does not support can_merge_blocks_p.", cfg_hooks->name); | |
473 | ||
474 | ret = cfg_hooks->can_merge_blocks_p (bb1, bb2); | |
475 | ||
476 | return ret; | |
477 | } | |
478 | ||
6de9cd9a DN |
479 | void |
480 | predict_edge (edge e, enum br_predictor predictor, int probability) | |
481 | { | |
482 | if (!cfg_hooks->predict_edge) | |
483 | internal_error ("%s does not support predict_edge.", cfg_hooks->name); | |
484 | ||
485 | cfg_hooks->predict_edge (e, predictor, probability); | |
486 | } | |
487 | ||
488 | bool | |
489 | predicted_by_p (basic_block bb, enum br_predictor predictor) | |
490 | { | |
491 | if (!cfg_hooks->predict_edge) | |
492 | internal_error ("%s does not support predicted_by_p.", cfg_hooks->name); | |
493 | ||
494 | return cfg_hooks->predicted_by_p (bb, predictor); | |
495 | } | |
496 | ||
f470c378 ZD |
497 | /* Merges basic block B into basic block A. */ |
498 | ||
499 | void | |
500 | merge_blocks (basic_block a, basic_block b) | |
501 | { | |
502 | edge e; | |
503 | ||
504 | if (!cfg_hooks->merge_blocks) | |
505 | internal_error ("%s does not support merge_blocks.", cfg_hooks->name); | |
506 | ||
507 | cfg_hooks->merge_blocks (a, b); | |
508 | ||
509 | /* Normally there should only be one successor of A and that is B, but | |
510 | partway though the merge of blocks for conditional_execution we'll | |
511 | be merging a TEST block with THEN and ELSE successors. Free the | |
512 | whole lot of them and hope the caller knows what they're doing. */ | |
513 | while (a->succ) | |
514 | remove_edge (a->succ); | |
515 | ||
516 | /* Adjust the edges out of B for the new owner. */ | |
517 | for (e = b->succ; e; e = e->succ_next) | |
518 | e->src = a; | |
519 | a->succ = b->succ; | |
520 | a->flags |= b->flags; | |
521 | ||
522 | /* B hasn't quite yet ceased to exist. Attempt to prevent mishap. */ | |
523 | b->pred = b->succ = NULL; | |
524 | a->global_live_at_end = b->global_live_at_end; | |
525 | ||
526 | if (dom_computed[CDI_DOMINATORS]) | |
527 | redirect_immediate_dominators (CDI_DOMINATORS, b, a); | |
528 | ||
529 | if (dom_computed[CDI_DOMINATORS]) | |
530 | delete_from_dominance_info (CDI_DOMINATORS, b); | |
531 | if (dom_computed[CDI_POST_DOMINATORS]) | |
532 | delete_from_dominance_info (CDI_POST_DOMINATORS, b); | |
533 | ||
534 | expunge_block (b); | |
535 | } | |
536 | ||
537 | /* Split BB into entry part and the rest (the rest is the newly created block). | |
538 | Redirect those edges for that REDIRECT_EDGE_P returns true to the entry | |
539 | part. Returns the edge connecting the entry part to the rest. */ | |
540 | ||
541 | edge | |
542 | make_forwarder_block (basic_block bb, bool (*redirect_edge_p) (edge), | |
543 | void (*new_bb_cbk) (basic_block)) | |
544 | { | |
545 | edge e, next_e, fallthru; | |
546 | basic_block dummy, jump; | |
547 | ||
548 | if (!cfg_hooks->make_forwarder_block) | |
549 | internal_error ("%s does not support make_forwarder_block.", | |
550 | cfg_hooks->name); | |
551 | ||
552 | fallthru = split_block_after_labels (bb); | |
553 | dummy = fallthru->src; | |
554 | bb = fallthru->dest; | |
555 | ||
556 | /* Redirect back edges we want to keep. */ | |
557 | for (e = dummy->pred; e; e = next_e) | |
558 | { | |
559 | next_e = e->pred_next; | |
560 | if (redirect_edge_p (e)) | |
561 | continue; | |
562 | ||
563 | dummy->frequency -= EDGE_FREQUENCY (e); | |
564 | dummy->count -= e->count; | |
565 | if (dummy->frequency < 0) | |
566 | dummy->frequency = 0; | |
567 | if (dummy->count < 0) | |
568 | dummy->count = 0; | |
649b2789 PH |
569 | fallthru->count -= e->count; |
570 | if (fallthru->count < 0) | |
571 | fallthru->count = 0; | |
f470c378 ZD |
572 | |
573 | jump = redirect_edge_and_branch_force (e, bb); | |
574 | if (jump) | |
575 | new_bb_cbk (jump); | |
576 | } | |
577 | ||
578 | if (dom_computed[CDI_DOMINATORS] >= DOM_CONS_OK) | |
579 | { | |
580 | basic_block doms_to_fix[2]; | |
581 | ||
582 | doms_to_fix[0] = dummy; | |
583 | doms_to_fix[1] = bb; | |
584 | iterate_fix_dominators (CDI_DOMINATORS, doms_to_fix, 2); | |
585 | } | |
586 | ||
587 | cfg_hooks->make_forwarder_block (fallthru); | |
588 | ||
589 | return fallthru; | |
590 | } | |
591 | ||
592 | void | |
593 | tidy_fallthru_edge (edge e) | |
594 | { | |
595 | if (cfg_hooks->tidy_fallthru_edge) | |
596 | cfg_hooks->tidy_fallthru_edge (e); | |
597 | } | |
598 | ||
599 | /* Fix up edges that now fall through, or rather should now fall through | |
600 | but previously required a jump around now deleted blocks. Simplify | |
601 | the search by only examining blocks numerically adjacent, since this | |
602 | is how find_basic_blocks created them. */ | |
603 | ||
604 | void | |
605 | tidy_fallthru_edges (void) | |
606 | { | |
607 | basic_block b, c; | |
608 | ||
609 | if (!cfg_hooks->tidy_fallthru_edge) | |
610 | return; | |
611 | ||
612 | if (ENTRY_BLOCK_PTR->next_bb == EXIT_BLOCK_PTR) | |
613 | return; | |
614 | ||
615 | FOR_BB_BETWEEN (b, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR->prev_bb, next_bb) | |
616 | { | |
617 | edge s; | |
618 | ||
619 | c = b->next_bb; | |
620 | ||
621 | /* We care about simple conditional or unconditional jumps with | |
622 | a single successor. | |
623 | ||
624 | If we had a conditional branch to the next instruction when | |
625 | find_basic_blocks was called, then there will only be one | |
626 | out edge for the block which ended with the conditional | |
627 | branch (since we do not create duplicate edges). | |
628 | ||
629 | Furthermore, the edge will be marked as a fallthru because we | |
630 | merge the flags for the duplicate edges. So we do not want to | |
631 | check that the edge is not a FALLTHRU edge. */ | |
632 | ||
633 | if ((s = b->succ) != NULL | |
634 | && ! (s->flags & EDGE_COMPLEX) | |
635 | && s->succ_next == NULL | |
750054a2 CT |
636 | && s->dest == c |
637 | && !find_reg_note (BB_END (b), REG_CROSSING_JUMP, NULL_RTX)) | |
f470c378 ZD |
638 | tidy_fallthru_edge (s); |
639 | } | |
640 | } | |
6de9cd9a DN |
641 | |
642 | /* Returns true if we can duplicate basic block BB. */ | |
643 | ||
644 | bool | |
645 | can_duplicate_block_p (basic_block bb) | |
646 | { | |
647 | edge e; | |
648 | ||
649 | if (!cfg_hooks->can_duplicate_block_p) | |
650 | internal_error ("%s does not support can_duplicate_block_p.", | |
651 | cfg_hooks->name); | |
652 | ||
653 | if (bb == EXIT_BLOCK_PTR || bb == ENTRY_BLOCK_PTR) | |
654 | return false; | |
655 | ||
656 | /* Duplicating fallthru block to exit would require adding a jump | |
657 | and splitting the real last BB. */ | |
658 | for (e = bb->succ; e; e = e->succ_next) | |
659 | if (e->dest == EXIT_BLOCK_PTR && e->flags & EDGE_FALLTHRU) | |
660 | return false; | |
661 | ||
662 | return cfg_hooks->can_duplicate_block_p (bb); | |
663 | } | |
664 | ||
665 | /* Duplicates basic block BB and redirects edge E to it. Returns the | |
666 | new basic block. */ | |
667 | ||
668 | basic_block | |
669 | duplicate_block (basic_block bb, edge e) | |
670 | { | |
671 | edge s, n; | |
672 | basic_block new_bb; | |
673 | gcov_type new_count = e ? e->count : 0; | |
674 | ||
675 | if (!cfg_hooks->duplicate_block) | |
676 | internal_error ("%s does not support duplicate_block.", | |
677 | cfg_hooks->name); | |
678 | ||
679 | if (bb->count < new_count) | |
680 | new_count = bb->count; | |
341c100f | 681 | gcc_assert (bb->pred); |
6de9cd9a | 682 | #ifdef ENABLE_CHECKING |
341c100f | 683 | gcc_assert (can_duplicate_block_p (bb)); |
6de9cd9a DN |
684 | #endif |
685 | ||
686 | new_bb = cfg_hooks->duplicate_block (bb); | |
687 | ||
688 | new_bb->loop_depth = bb->loop_depth; | |
689 | new_bb->flags = bb->flags; | |
690 | for (s = bb->succ; s; s = s->succ_next) | |
691 | { | |
692 | /* Since we are creating edges from a new block to successors | |
693 | of another block (which therefore are known to be disjoint), there | |
694 | is no need to actually check for duplicated edges. */ | |
695 | n = unchecked_make_edge (new_bb, s->dest, s->flags); | |
696 | n->probability = s->probability; | |
697 | if (e && bb->count) | |
698 | { | |
699 | /* Take care for overflows! */ | |
700 | n->count = s->count * (new_count * 10000 / bb->count) / 10000; | |
701 | s->count -= n->count; | |
702 | } | |
703 | else | |
704 | n->count = s->count; | |
705 | n->aux = s->aux; | |
706 | } | |
707 | ||
708 | if (e) | |
709 | { | |
710 | new_bb->count = new_count; | |
711 | bb->count -= new_count; | |
712 | ||
713 | new_bb->frequency = EDGE_FREQUENCY (e); | |
714 | bb->frequency -= EDGE_FREQUENCY (e); | |
715 | ||
716 | redirect_edge_and_branch_force (e, new_bb); | |
717 | ||
718 | if (bb->count < 0) | |
719 | bb->count = 0; | |
720 | if (bb->frequency < 0) | |
721 | bb->frequency = 0; | |
722 | } | |
723 | else | |
724 | { | |
725 | new_bb->count = bb->count; | |
726 | new_bb->frequency = bb->frequency; | |
727 | } | |
728 | ||
729 | new_bb->rbi->original = bb; | |
730 | bb->rbi->copy = new_bb; | |
731 | ||
732 | return new_bb; | |
733 | } | |
734 | ||
735 | /* Return 1 if BB ends with a call, possibly followed by some | |
736 | instructions that must stay with the call, 0 otherwise. */ | |
737 | ||
738 | bool | |
739 | block_ends_with_call_p (basic_block bb) | |
740 | { | |
741 | if (!cfg_hooks->block_ends_with_call_p) | |
742 | internal_error ("%s does not support block_ends_with_call_p", cfg_hooks->name); | |
743 | ||
744 | return (cfg_hooks->block_ends_with_call_p) (bb); | |
745 | } | |
746 | ||
747 | /* Return 1 if BB ends with a conditional branch, 0 otherwise. */ | |
748 | ||
749 | bool | |
750 | block_ends_with_condjump_p (basic_block bb) | |
751 | { | |
752 | if (!cfg_hooks->block_ends_with_condjump_p) | |
753 | internal_error ("%s does not support block_ends_with_condjump_p", | |
754 | cfg_hooks->name); | |
755 | ||
756 | return (cfg_hooks->block_ends_with_condjump_p) (bb); | |
757 | } | |
758 | ||
759 | /* Add fake edges to the function exit for any non constant and non noreturn | |
760 | calls, volatile inline assembly in the bitmap of blocks specified by | |
761 | BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks | |
762 | that were split. | |
763 | ||
764 | The goal is to expose cases in which entering a basic block does not imply | |
765 | that all subsequent instructions must be executed. */ | |
766 | ||
767 | int | |
768 | flow_call_edges_add (sbitmap blocks) | |
769 | { | |
770 | if (!cfg_hooks->flow_call_edges_add) | |
771 | internal_error ("%s does not support flow_call_edges_add", | |
772 | cfg_hooks->name); | |
773 | ||
774 | return (cfg_hooks->flow_call_edges_add) (blocks); | |
775 | } |