1 | /* Control flow graph manipulation code for GNU compiler. |
2 | Copyright (C) 1987-2023 Free Software Foundation, Inc. |
3 | |
4 | This file is part of GCC. |
5 | |
6 | GCC is free software; you can redistribute it and/or modify it under |
7 | the terms of the GNU General Public License as published by the Free |
8 | Software Foundation; either version 3, or (at your option) any later |
9 | version. |
10 | |
11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
12 | 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 COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ |
19 | |
20 | /* This file contains low level functions to manipulate the CFG and |
21 | analyze it. All other modules should not transform the data structure |
22 | directly and use abstraction instead. The file is supposed to be |
23 | ordered bottom-up and should not contain any code dependent on a |
24 | particular intermediate language (RTL or trees). |
25 | |
26 | Available functionality: |
27 | - Initialization/deallocation |
28 | init_flow, free_cfg |
29 | - Low level basic block manipulation |
30 | alloc_block, expunge_block |
31 | - Edge manipulation |
32 | make_edge, make_single_succ_edge, cached_make_edge, remove_edge |
33 | - Low level edge redirection (without updating instruction chain) |
34 | redirect_edge_succ, redirect_edge_succ_nodup, redirect_edge_pred |
35 | - Dumping and debugging |
36 | dump_flow_info, debug_flow_info, dump_edge_info |
37 | - Allocation of AUX fields for basic blocks |
38 | alloc_aux_for_blocks, free_aux_for_blocks, alloc_aux_for_block |
39 | - clear_bb_flags |
40 | - Consistency checking |
41 | verify_flow_info |
42 | - Dumping and debugging |
43 | print_rtl_with_bb, dump_bb, debug_bb, debug_bb_n |
44 | |
45 | TODO: Document these "Available functionality" functions in the files |
46 | that implement them. |
47 | */ |
48 | |
49 | #include "config.h" |
50 | #include "system.h" |
51 | #include "coretypes.h" |
52 | #include "backend.h" |
53 | #include "hard-reg-set.h" |
54 | #include "tree.h" |
55 | #include "cfghooks.h" |
56 | #include "df.h" |
57 | #include "cfganal.h" |
58 | #include "cfgloop.h" /* FIXME: For struct loop. */ |
59 | #include "dumpfile.h" |
60 | |
61 | |
62 | |
63 | /* Called once at initialization time. */ |
64 | |
65 | void |
66 | init_flow (struct function *the_fun) |
67 | { |
68 | if (!the_fun->cfg) |
69 | the_fun->cfg = ggc_cleared_alloc<control_flow_graph> (); |
70 | n_edges_for_fn (the_fun) = 0; |
71 | the_fun->cfg->count_max = profile_count::uninitialized (); |
72 | ENTRY_BLOCK_PTR_FOR_FN (the_fun) |
73 | = alloc_block (); |
74 | ENTRY_BLOCK_PTR_FOR_FN (the_fun)->index = ENTRY_BLOCK; |
75 | EXIT_BLOCK_PTR_FOR_FN (the_fun) |
76 | = alloc_block (); |
77 | EXIT_BLOCK_PTR_FOR_FN (the_fun)->index = EXIT_BLOCK; |
78 | ENTRY_BLOCK_PTR_FOR_FN (the_fun)->next_bb |
79 | = EXIT_BLOCK_PTR_FOR_FN (the_fun); |
80 | EXIT_BLOCK_PTR_FOR_FN (the_fun)->prev_bb |
81 | = ENTRY_BLOCK_PTR_FOR_FN (the_fun); |
82 | the_fun->cfg->edge_flags_allocated = EDGE_ALL_FLAGS; |
83 | the_fun->cfg->bb_flags_allocated = BB_ALL_FLAGS; |
84 | the_fun->cfg->full_profile = false; |
85 | } |
86 | |
87 | /* Helper function for remove_edge and free_cffg. Frees edge structure |
88 | without actually removing it from the pred/succ arrays. */ |
89 | |
90 | static void |
91 | free_edge (function *fn, edge e) |
92 | { |
93 | n_edges_for_fn (fn)--; |
94 | ggc_free (e); |
95 | } |
96 | |
97 | /* Free basic block BB. */ |
98 | |
99 | static void |
100 | free_block (basic_block bb) |
101 | { |
102 | vec_free (v&: bb->succs); |
103 | bb->succs = NULL; |
104 | vec_free (v&: bb->preds); |
105 | bb->preds = NULL; |
106 | ggc_free (bb); |
107 | } |
108 | |
109 | /* Free the memory associated with the CFG in FN. */ |
110 | |
111 | void |
112 | free_cfg (struct function *fn) |
113 | { |
114 | edge e; |
115 | edge_iterator ei; |
116 | basic_block next; |
117 | |
118 | for (basic_block bb = ENTRY_BLOCK_PTR_FOR_FN (fn); bb; bb = next) |
119 | { |
120 | next = bb->next_bb; |
121 | FOR_EACH_EDGE (e, ei, bb->succs) |
122 | free_edge (fn, e); |
123 | free_block (bb); |
124 | } |
125 | |
126 | gcc_assert (!n_edges_for_fn (fn)); |
127 | /* Sanity check that dominance tree is freed. */ |
128 | gcc_assert (!fn->cfg->x_dom_computed[0] && !fn->cfg->x_dom_computed[1]); |
129 | |
130 | vec_free (v&: fn->cfg->x_label_to_block_map); |
131 | vec_free (basic_block_info_for_fn (fn)); |
132 | ggc_free (fn->cfg); |
133 | fn->cfg = NULL; |
134 | } |
135 | |
136 | /* Allocate memory for basic_block. */ |
137 | |
138 | basic_block |
139 | alloc_block (void) |
140 | { |
141 | basic_block bb; |
142 | bb = ggc_cleared_alloc<basic_block_def> (); |
143 | bb->count = profile_count::uninitialized (); |
144 | return bb; |
145 | } |
146 | |
147 | /* Link block B to chain after AFTER. */ |
148 | void |
149 | link_block (basic_block b, basic_block after) |
150 | { |
151 | b->next_bb = after->next_bb; |
152 | b->prev_bb = after; |
153 | after->next_bb = b; |
154 | b->next_bb->prev_bb = b; |
155 | } |
156 | |
157 | /* Unlink block B from chain. */ |
158 | void |
159 | unlink_block (basic_block b) |
160 | { |
161 | b->next_bb->prev_bb = b->prev_bb; |
162 | b->prev_bb->next_bb = b->next_bb; |
163 | b->prev_bb = NULL; |
164 | b->next_bb = NULL; |
165 | } |
166 | |
167 | /* Sequentially order blocks and compact the arrays. */ |
168 | void |
169 | compact_blocks (void) |
170 | { |
171 | int i; |
172 | |
173 | SET_BASIC_BLOCK_FOR_FN (cfun, ENTRY_BLOCK, ENTRY_BLOCK_PTR_FOR_FN (cfun)); |
174 | SET_BASIC_BLOCK_FOR_FN (cfun, EXIT_BLOCK, EXIT_BLOCK_PTR_FOR_FN (cfun)); |
175 | |
176 | if (df) |
177 | df_compact_blocks (); |
178 | else |
179 | { |
180 | basic_block bb; |
181 | |
182 | i = NUM_FIXED_BLOCKS; |
183 | FOR_EACH_BB_FN (bb, cfun) |
184 | { |
185 | SET_BASIC_BLOCK_FOR_FN (cfun, i, bb); |
186 | bb->index = i; |
187 | i++; |
188 | } |
189 | gcc_assert (i == n_basic_blocks_for_fn (cfun)); |
190 | |
191 | for (; i < last_basic_block_for_fn (cfun); i++) |
192 | SET_BASIC_BLOCK_FOR_FN (cfun, i, NULL); |
193 | } |
194 | last_basic_block_for_fn (cfun) = n_basic_blocks_for_fn (cfun); |
195 | } |
196 | |
197 | /* Remove block B from the basic block array. */ |
198 | |
199 | void |
200 | expunge_block (basic_block b) |
201 | { |
202 | unlink_block (b); |
203 | SET_BASIC_BLOCK_FOR_FN (cfun, b->index, NULL); |
204 | n_basic_blocks_for_fn (cfun)--; |
205 | /* We should be able to ggc_free here, but we are not. |
206 | The dead SSA_NAMES are left pointing to dead statements that are pointing |
207 | to dead basic blocks making garbage collector to die. |
208 | We should be able to release all dead SSA_NAMES and at the same time we |
209 | should clear out BB pointer of dead statements consistently. */ |
210 | } |
211 | |
212 | /* Connect E to E->src. */ |
213 | |
214 | static inline void |
215 | connect_src (edge e) |
216 | { |
217 | vec_safe_push (v&: e->src->succs, obj: e); |
218 | df_mark_solutions_dirty (); |
219 | } |
220 | |
221 | /* Connect E to E->dest. */ |
222 | |
223 | static inline void |
224 | connect_dest (edge e) |
225 | { |
226 | basic_block dest = e->dest; |
227 | vec_safe_push (v&: dest->preds, obj: e); |
228 | e->dest_idx = EDGE_COUNT (dest->preds) - 1; |
229 | df_mark_solutions_dirty (); |
230 | } |
231 | |
232 | /* Disconnect edge E from E->src. */ |
233 | |
234 | static inline void |
235 | disconnect_src (edge e) |
236 | { |
237 | basic_block src = e->src; |
238 | edge_iterator ei; |
239 | edge tmp; |
240 | |
241 | for (ei = ei_start (src->succs); (tmp = ei_safe_edge (i: ei)); ) |
242 | { |
243 | if (tmp == e) |
244 | { |
245 | src->succs->unordered_remove (ix: ei.index); |
246 | df_mark_solutions_dirty (); |
247 | return; |
248 | } |
249 | else |
250 | ei_next (i: &ei); |
251 | } |
252 | |
253 | gcc_unreachable (); |
254 | } |
255 | |
256 | /* Disconnect edge E from E->dest. */ |
257 | |
258 | static inline void |
259 | disconnect_dest (edge e) |
260 | { |
261 | basic_block dest = e->dest; |
262 | unsigned int dest_idx = e->dest_idx; |
263 | |
264 | dest->preds->unordered_remove (ix: dest_idx); |
265 | |
266 | /* If we removed an edge in the middle of the edge vector, we need |
267 | to update dest_idx of the edge that moved into the "hole". */ |
268 | if (dest_idx < EDGE_COUNT (dest->preds)) |
269 | EDGE_PRED (dest, dest_idx)->dest_idx = dest_idx; |
270 | df_mark_solutions_dirty (); |
271 | } |
272 | |
273 | /* Create an edge connecting SRC and DEST with flags FLAGS. Return newly |
274 | created edge. Use this only if you are sure that this edge can't |
275 | possibly already exist. */ |
276 | |
277 | edge |
278 | unchecked_make_edge (basic_block src, basic_block dst, int flags) |
279 | { |
280 | edge e; |
281 | e = ggc_cleared_alloc<edge_def> (); |
282 | n_edges_for_fn (cfun)++; |
283 | |
284 | e->probability = profile_probability::uninitialized (); |
285 | e->src = src; |
286 | e->dest = dst; |
287 | e->flags = flags; |
288 | |
289 | connect_src (e); |
290 | connect_dest (e); |
291 | |
292 | execute_on_growing_pred (e); |
293 | return e; |
294 | } |
295 | |
296 | /* Create an edge connecting SRC and DST with FLAGS optionally using |
297 | edge cache CACHE. Return the new edge, NULL if already exist. */ |
298 | |
299 | edge |
300 | cached_make_edge (sbitmap edge_cache, basic_block src, basic_block dst, int flags) |
301 | { |
302 | if (edge_cache == NULL |
303 | || src == ENTRY_BLOCK_PTR_FOR_FN (cfun) |
304 | || dst == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
305 | return make_edge (src, dst, flags); |
306 | |
307 | /* Does the requested edge already exist? */ |
308 | if (! bitmap_bit_p (map: edge_cache, bitno: dst->index)) |
309 | { |
310 | /* The edge does not exist. Create one and update the |
311 | cache. */ |
312 | bitmap_set_bit (map: edge_cache, bitno: dst->index); |
313 | return unchecked_make_edge (src, dst, flags); |
314 | } |
315 | |
316 | /* At this point, we know that the requested edge exists. Adjust |
317 | flags if necessary. */ |
318 | if (flags) |
319 | { |
320 | edge e = find_edge (src, dst); |
321 | e->flags |= flags; |
322 | } |
323 | |
324 | return NULL; |
325 | } |
326 | |
327 | /* Create an edge connecting SRC and DEST with flags FLAGS. Return newly |
328 | created edge or NULL if already exist. */ |
329 | |
330 | edge |
331 | make_edge (basic_block src, basic_block dest, int flags) |
332 | { |
333 | edge e = find_edge (src, dest); |
334 | |
335 | /* Make sure we don't add duplicate edges. */ |
336 | if (e) |
337 | { |
338 | e->flags |= flags; |
339 | return NULL; |
340 | } |
341 | |
342 | return unchecked_make_edge (src, dst: dest, flags); |
343 | } |
344 | |
345 | /* Create an edge connecting SRC to DEST and set probability by knowing |
346 | that it is the single edge leaving SRC. */ |
347 | |
348 | edge |
349 | make_single_succ_edge (basic_block src, basic_block dest, int flags) |
350 | { |
351 | edge e = make_edge (src, dest, flags); |
352 | |
353 | e->probability = profile_probability::always (); |
354 | return e; |
355 | } |
356 | |
357 | /* This function will remove an edge from the flow graph. */ |
358 | |
359 | void |
360 | remove_edge_raw (edge e) |
361 | { |
362 | remove_predictions_associated_with_edge (e); |
363 | execute_on_shrinking_pred (e); |
364 | |
365 | disconnect_src (e); |
366 | disconnect_dest (e); |
367 | |
368 | free_edge (cfun, e); |
369 | } |
370 | |
371 | /* Redirect an edge's successor from one block to another. */ |
372 | |
373 | void |
374 | redirect_edge_succ (edge e, basic_block new_succ) |
375 | { |
376 | execute_on_shrinking_pred (e); |
377 | |
378 | disconnect_dest (e); |
379 | |
380 | e->dest = new_succ; |
381 | |
382 | /* Reconnect the edge to the new successor block. */ |
383 | connect_dest (e); |
384 | |
385 | execute_on_growing_pred (e); |
386 | } |
387 | |
388 | /* Redirect an edge's predecessor from one block to another. */ |
389 | |
390 | void |
391 | redirect_edge_pred (edge e, basic_block new_pred) |
392 | { |
393 | disconnect_src (e); |
394 | |
395 | e->src = new_pred; |
396 | |
397 | /* Reconnect the edge to the new predecessor block. */ |
398 | connect_src (e); |
399 | } |
400 | |
401 | /* Clear all basic block flags that do not have to be preserved. */ |
402 | void |
403 | clear_bb_flags (void) |
404 | { |
405 | basic_block bb; |
406 | int flags_to_preserve = BB_FLAGS_TO_PRESERVE; |
407 | if (current_loops |
408 | && loops_state_satisfies_p (cfun, flags: LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) |
409 | flags_to_preserve |= BB_IRREDUCIBLE_LOOP; |
410 | |
411 | FOR_ALL_BB_FN (bb, cfun) |
412 | bb->flags &= flags_to_preserve; |
413 | } |
414 | |
415 | /* Check the consistency of profile information. We can't do that |
416 | in verify_flow_info, as the counts may get invalid for incompletely |
417 | solved graphs, later eliminating of conditionals or roundoff errors. |
418 | It is still practical to have them reported for debugging of simple |
419 | testcases. */ |
420 | static void |
421 | check_bb_profile (basic_block bb, FILE * file, int indent) |
422 | { |
423 | edge e; |
424 | edge_iterator ei; |
425 | struct function *fun = DECL_STRUCT_FUNCTION (current_function_decl); |
426 | char *s_indent = (char *) alloca ((size_t) indent + 1); |
427 | memset (s: (void *) s_indent, c: ' ', n: (size_t) indent); |
428 | s_indent[indent] = '\0'; |
429 | |
430 | if (profile_status_for_fn (fun) == PROFILE_ABSENT) |
431 | return; |
432 | |
433 | if (bb != EXIT_BLOCK_PTR_FOR_FN (fun)) |
434 | { |
435 | bool found = false; |
436 | profile_probability sum = profile_probability::never (); |
437 | int isum = 0; |
438 | |
439 | FOR_EACH_EDGE (e, ei, bb->succs) |
440 | { |
441 | if (!(e->flags & (EDGE_EH | EDGE_FAKE))) |
442 | found = true; |
443 | sum += e->probability; |
444 | if (e->probability.initialized_p ()) |
445 | isum += e->probability.to_reg_br_prob_base (); |
446 | } |
447 | /* Only report mismatches for non-EH control flow. If there are only EH |
448 | edges it means that the BB ends by noreturn call. Here the control |
449 | flow may just terminate. */ |
450 | if (found) |
451 | { |
452 | if (sum.differs_from_p (other: profile_probability::always ())) |
453 | { |
454 | fprintf (stream: file, |
455 | format: ";; %sInvalid sum of outgoing probabilities " , |
456 | s_indent); |
457 | sum.dump (f: file); |
458 | fprintf (stream: file, format: "\n" ); |
459 | } |
460 | /* Probabilities caps to 100% and thus the previous test will never |
461 | fire if the sum of probabilities is too large. */ |
462 | else if (isum > REG_BR_PROB_BASE + 100) |
463 | { |
464 | fprintf (stream: file, |
465 | format: ";; %sInvalid sum of outgoing probabilities %.1f%%\n" , |
466 | s_indent, isum * 100.0 / REG_BR_PROB_BASE); |
467 | } |
468 | } |
469 | } |
470 | if (bb != ENTRY_BLOCK_PTR_FOR_FN (fun)) |
471 | { |
472 | profile_count sum = profile_count::zero (); |
473 | FOR_EACH_EDGE (e, ei, bb->preds) |
474 | sum += e->count (); |
475 | if (sum.differs_from_p (other: bb->count)) |
476 | { |
477 | fprintf (stream: file, format: ";; %sInvalid sum of incoming counts " , |
478 | s_indent); |
479 | sum.dump (f: file, fun); |
480 | fprintf (stream: file, format: ", should be " ); |
481 | bb->count.dump (f: file, fun); |
482 | fprintf (stream: file, format: "\n" ); |
483 | } |
484 | } |
485 | if (BB_PARTITION (bb) == BB_COLD_PARTITION) |
486 | { |
487 | /* Warn about inconsistencies in the partitioning that are |
488 | currently caused by profile insanities created via optimization. */ |
489 | if (!probably_never_executed_bb_p (fun, bb)) |
490 | fprintf (stream: file, format: ";; %sBlock in cold partition with hot count\n" , |
491 | s_indent); |
492 | FOR_EACH_EDGE (e, ei, bb->preds) |
493 | { |
494 | if (!probably_never_executed_edge_p (fun, e)) |
495 | fprintf (stream: file, |
496 | format: ";; %sBlock in cold partition with incoming hot edge\n" , |
497 | s_indent); |
498 | } |
499 | } |
500 | } |
501 | |
502 | void |
503 | dump_edge_info (FILE *file, edge e, dump_flags_t flags, int do_succ) |
504 | { |
505 | basic_block side = (do_succ ? e->dest : e->src); |
506 | bool do_details = false; |
507 | |
508 | if ((flags & TDF_DETAILS) != 0 |
509 | && (flags & TDF_SLIM) == 0) |
510 | do_details = true; |
511 | |
512 | if (side->index == ENTRY_BLOCK) |
513 | fputs (s: " ENTRY" , stream: file); |
514 | else if (side->index == EXIT_BLOCK) |
515 | fputs (s: " EXIT" , stream: file); |
516 | else |
517 | fprintf (stream: file, format: " %d" , side->index); |
518 | |
519 | if (e->probability.initialized_p () && do_details) |
520 | { |
521 | fprintf (stream: file, format: " [" ); |
522 | e->probability.dump (f: file); |
523 | fprintf (stream: file, format: "] " ); |
524 | } |
525 | |
526 | if (e->count ().initialized_p () && do_details) |
527 | { |
528 | fputs (s: " count:" , stream: file); |
529 | e->count ().dump (f: file, cfun); |
530 | } |
531 | |
532 | if (e->flags && do_details) |
533 | { |
534 | static const char * const bitnames[] = |
535 | { |
536 | #define DEF_EDGE_FLAG(NAME,IDX) #NAME , |
537 | #include "cfg-flags.def" |
538 | NULL |
539 | #undef DEF_EDGE_FLAG |
540 | }; |
541 | bool comma = false; |
542 | int i, flags = e->flags; |
543 | |
544 | gcc_assert (e->flags <= EDGE_ALL_FLAGS); |
545 | fputs (s: " (" , stream: file); |
546 | for (i = 0; flags; i++) |
547 | if (flags & (1 << i)) |
548 | { |
549 | flags &= ~(1 << i); |
550 | |
551 | if (comma) |
552 | fputc (c: ',', stream: file); |
553 | fputs (s: bitnames[i], stream: file); |
554 | comma = true; |
555 | } |
556 | |
557 | fputc (c: ')', stream: file); |
558 | } |
559 | |
560 | if (do_details && LOCATION_LOCUS (e->goto_locus) > BUILTINS_LOCATION) |
561 | fprintf (stream: file, format: " %s:%d:%d" , LOCATION_FILE (e->goto_locus), |
562 | LOCATION_LINE (e->goto_locus), LOCATION_COLUMN (e->goto_locus)); |
563 | } |
564 | |
565 | DEBUG_FUNCTION void |
566 | debug (edge_def &ref) |
567 | { |
568 | fprintf (stderr, format: "<edge (%d -> %d)>\n" , |
569 | ref.src->index, ref.dest->index); |
570 | dump_edge_info (stderr, e: &ref, flags: TDF_DETAILS, do_succ: false); |
571 | fprintf (stderr, format: "\n" ); |
572 | } |
573 | |
574 | DEBUG_FUNCTION void |
575 | debug (edge_def *ptr) |
576 | { |
577 | if (ptr) |
578 | debug (ref&: *ptr); |
579 | else |
580 | fprintf (stderr, format: "<nil>\n" ); |
581 | } |
582 | |
583 | static void |
584 | debug_slim (edge e) |
585 | { |
586 | fprintf (stderr, format: "<edge 0x%p (%d -> %d)>" , (void *) e, |
587 | e->src->index, e->dest->index); |
588 | } |
589 | |
590 | DEFINE_DEBUG_VEC (edge) |
591 | DEFINE_DEBUG_HASH_SET (edge) |
592 | |
593 | /* Simple routines to easily allocate AUX fields of basic blocks. */ |
594 | |
595 | static struct obstack block_aux_obstack; |
596 | static void *first_block_aux_obj = 0; |
597 | static struct obstack edge_aux_obstack; |
598 | static void *first_edge_aux_obj = 0; |
599 | |
600 | /* Allocate a memory block of SIZE as BB->aux. The obstack must |
601 | be first initialized by alloc_aux_for_blocks. */ |
602 | |
603 | static void |
604 | alloc_aux_for_block (basic_block bb, int size) |
605 | { |
606 | /* Verify that aux field is clear. */ |
607 | gcc_assert (!bb->aux && first_block_aux_obj); |
608 | bb->aux = obstack_alloc (&block_aux_obstack, size); |
609 | memset (s: bb->aux, c: 0, n: size); |
610 | } |
611 | |
612 | /* Initialize the block_aux_obstack and if SIZE is nonzero, call |
613 | alloc_aux_for_block for each basic block. */ |
614 | |
615 | void |
616 | alloc_aux_for_blocks (int size) |
617 | { |
618 | static int initialized; |
619 | |
620 | if (!initialized) |
621 | { |
622 | gcc_obstack_init (&block_aux_obstack); |
623 | initialized = 1; |
624 | } |
625 | else |
626 | /* Check whether AUX data are still allocated. */ |
627 | gcc_assert (!first_block_aux_obj); |
628 | |
629 | first_block_aux_obj = obstack_alloc (&block_aux_obstack, 0); |
630 | if (size) |
631 | { |
632 | basic_block bb; |
633 | |
634 | FOR_ALL_BB_FN (bb, cfun) |
635 | alloc_aux_for_block (bb, size); |
636 | } |
637 | } |
638 | |
639 | /* Clear AUX pointers of all blocks. */ |
640 | |
641 | void |
642 | clear_aux_for_blocks (void) |
643 | { |
644 | basic_block bb; |
645 | |
646 | FOR_ALL_BB_FN (bb, cfun) |
647 | bb->aux = NULL; |
648 | } |
649 | |
650 | /* Free data allocated in block_aux_obstack and clear AUX pointers |
651 | of all blocks. */ |
652 | |
653 | void |
654 | free_aux_for_blocks (void) |
655 | { |
656 | gcc_assert (first_block_aux_obj); |
657 | obstack_free (&block_aux_obstack, first_block_aux_obj); |
658 | first_block_aux_obj = NULL; |
659 | |
660 | clear_aux_for_blocks (); |
661 | } |
662 | |
663 | /* Allocate a memory edge of SIZE as E->aux. The obstack must |
664 | be first initialized by alloc_aux_for_edges. */ |
665 | |
666 | void |
667 | alloc_aux_for_edge (edge e, int size) |
668 | { |
669 | /* Verify that aux field is clear. */ |
670 | gcc_assert (!e->aux && first_edge_aux_obj); |
671 | e->aux = obstack_alloc (&edge_aux_obstack, size); |
672 | memset (s: e->aux, c: 0, n: size); |
673 | } |
674 | |
675 | /* Initialize the edge_aux_obstack and if SIZE is nonzero, call |
676 | alloc_aux_for_edge for each basic edge. */ |
677 | |
678 | void |
679 | alloc_aux_for_edges (int size) |
680 | { |
681 | static int initialized; |
682 | |
683 | if (!initialized) |
684 | { |
685 | gcc_obstack_init (&edge_aux_obstack); |
686 | initialized = 1; |
687 | } |
688 | else |
689 | /* Check whether AUX data are still allocated. */ |
690 | gcc_assert (!first_edge_aux_obj); |
691 | |
692 | first_edge_aux_obj = obstack_alloc (&edge_aux_obstack, 0); |
693 | if (size) |
694 | { |
695 | basic_block bb; |
696 | |
697 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun), |
698 | EXIT_BLOCK_PTR_FOR_FN (cfun), next_bb) |
699 | { |
700 | edge e; |
701 | edge_iterator ei; |
702 | |
703 | FOR_EACH_EDGE (e, ei, bb->succs) |
704 | alloc_aux_for_edge (e, size); |
705 | } |
706 | } |
707 | } |
708 | |
709 | /* Clear AUX pointers of all edges. */ |
710 | |
711 | void |
712 | clear_aux_for_edges (void) |
713 | { |
714 | basic_block bb; |
715 | edge e; |
716 | |
717 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun), |
718 | EXIT_BLOCK_PTR_FOR_FN (cfun), next_bb) |
719 | { |
720 | edge_iterator ei; |
721 | FOR_EACH_EDGE (e, ei, bb->succs) |
722 | e->aux = NULL; |
723 | } |
724 | } |
725 | |
726 | /* Free data allocated in edge_aux_obstack and clear AUX pointers |
727 | of all edges. */ |
728 | |
729 | void |
730 | free_aux_for_edges (void) |
731 | { |
732 | gcc_assert (first_edge_aux_obj); |
733 | obstack_free (&edge_aux_obstack, first_edge_aux_obj); |
734 | first_edge_aux_obj = NULL; |
735 | |
736 | clear_aux_for_edges (); |
737 | } |
738 | |
739 | DEBUG_FUNCTION void |
740 | debug_bb (basic_block bb) |
741 | { |
742 | debug_bb (bb, dump_flags); |
743 | } |
744 | |
745 | DEBUG_FUNCTION basic_block |
746 | debug_bb_n (int n) |
747 | { |
748 | basic_block bb = BASIC_BLOCK_FOR_FN (cfun, n); |
749 | debug_bb (bb); |
750 | return bb; |
751 | } |
752 | |
753 | /* Print BB with specified FLAGS. */ |
754 | |
755 | DEBUG_FUNCTION void |
756 | debug_bb (basic_block bb, dump_flags_t flags) |
757 | { |
758 | dump_bb (stderr, bb, 0, flags); |
759 | } |
760 | |
761 | /* Print basic block numbered N with specified FLAGS. */ |
762 | |
763 | DEBUG_FUNCTION basic_block |
764 | debug_bb_n (int n, dump_flags_t flags) |
765 | { |
766 | basic_block bb = BASIC_BLOCK_FOR_FN (cfun, n); |
767 | debug_bb (bb, flags); |
768 | return bb; |
769 | } |
770 | |
771 | /* Dumps cfg related information about basic block BB to OUTF. |
772 | If HEADER is true, dump things that appear before the instructions |
773 | contained in BB. If FOOTER is true, dump things that appear after. |
774 | Flags are the TDF_* masks as documented in dumpfile.h. |
775 | NB: With TDF_DETAILS, it is assumed that cfun is available, so |
776 | that maybe_hot_bb_p and probably_never_executed_bb_p don't ICE. */ |
777 | |
778 | void |
779 | dump_bb_info (FILE *outf, basic_block bb, int indent, dump_flags_t flags, |
780 | bool , bool ) |
781 | { |
782 | edge_iterator ei; |
783 | edge e; |
784 | static const char * const bb_bitnames[] = |
785 | { |
786 | #define DEF_BASIC_BLOCK_FLAG(NAME,IDX) #NAME , |
787 | #include "cfg-flags.def" |
788 | NULL |
789 | #undef DEF_BASIC_BLOCK_FLAG |
790 | }; |
791 | const unsigned n_bitnames = ARRAY_SIZE (bb_bitnames); |
792 | bool first; |
793 | char *s_indent = (char *) alloca ((size_t) indent + 1); |
794 | memset (s: (void *) s_indent, c: ' ', n: (size_t) indent); |
795 | s_indent[indent] = '\0'; |
796 | |
797 | gcc_assert (bb->flags <= BB_ALL_FLAGS); |
798 | |
799 | if (do_header) |
800 | { |
801 | unsigned i; |
802 | |
803 | fputs (s: ";; " , stream: outf); |
804 | fprintf (stream: outf, format: "%sbasic block %d, loop depth %d" , |
805 | s_indent, bb->index, bb_loop_depth (bb)); |
806 | if (flags & TDF_DETAILS) |
807 | { |
808 | struct function *fun = DECL_STRUCT_FUNCTION (current_function_decl); |
809 | if (bb->count.initialized_p ()) |
810 | { |
811 | fputs (s: ", count " , stream: outf); |
812 | bb->count.dump (f: outf, cfun); |
813 | } |
814 | if (maybe_hot_bb_p (fun, bb)) |
815 | fputs (s: ", maybe hot" , stream: outf); |
816 | if (probably_never_executed_bb_p (fun, bb)) |
817 | fputs (s: ", probably never executed" , stream: outf); |
818 | } |
819 | fputc (c: '\n', stream: outf); |
820 | |
821 | if (flags & TDF_DETAILS) |
822 | { |
823 | check_bb_profile (bb, file: outf, indent); |
824 | fputs (s: ";; " , stream: outf); |
825 | fprintf (stream: outf, format: "%s prev block " , s_indent); |
826 | if (bb->prev_bb) |
827 | fprintf (stream: outf, format: "%d" , bb->prev_bb->index); |
828 | else |
829 | fprintf (stream: outf, format: "(nil)" ); |
830 | fprintf (stream: outf, format: ", next block " ); |
831 | if (bb->next_bb) |
832 | fprintf (stream: outf, format: "%d" , bb->next_bb->index); |
833 | else |
834 | fprintf (stream: outf, format: "(nil)" ); |
835 | |
836 | fputs (s: ", flags:" , stream: outf); |
837 | first = true; |
838 | for (i = 0; i < n_bitnames; i++) |
839 | if (bb->flags & (1 << i)) |
840 | { |
841 | if (first) |
842 | fputs (s: " (" , stream: outf); |
843 | else |
844 | fputs (s: ", " , stream: outf); |
845 | first = false; |
846 | fputs (s: bb_bitnames[i], stream: outf); |
847 | } |
848 | if (!first) |
849 | fputc (c: ')', stream: outf); |
850 | fputc (c: '\n', stream: outf); |
851 | } |
852 | |
853 | fputs (s: ";; " , stream: outf); |
854 | fprintf (stream: outf, format: "%s pred: " , s_indent); |
855 | first = true; |
856 | FOR_EACH_EDGE (e, ei, bb->preds) |
857 | { |
858 | if (! first) |
859 | { |
860 | fputs (s: ";; " , stream: outf); |
861 | fprintf (stream: outf, format: "%s " , s_indent); |
862 | } |
863 | first = false; |
864 | dump_edge_info (file: outf, e, flags, do_succ: 0); |
865 | fputc (c: '\n', stream: outf); |
866 | } |
867 | if (first) |
868 | fputc (c: '\n', stream: outf); |
869 | } |
870 | |
871 | if (do_footer) |
872 | { |
873 | fputs (s: ";; " , stream: outf); |
874 | fprintf (stream: outf, format: "%s succ: " , s_indent); |
875 | first = true; |
876 | FOR_EACH_EDGE (e, ei, bb->succs) |
877 | { |
878 | if (! first) |
879 | { |
880 | fputs (s: ";; " , stream: outf); |
881 | fprintf (stream: outf, format: "%s " , s_indent); |
882 | } |
883 | first = false; |
884 | dump_edge_info (file: outf, e, flags, do_succ: 1); |
885 | fputc (c: '\n', stream: outf); |
886 | } |
887 | if (first) |
888 | fputc (c: '\n', stream: outf); |
889 | } |
890 | } |
891 | |
892 | /* Dumps a brief description of cfg to FILE. */ |
893 | |
894 | void |
895 | brief_dump_cfg (FILE *file, dump_flags_t flags) |
896 | { |
897 | basic_block bb; |
898 | |
899 | FOR_EACH_BB_FN (bb, cfun) |
900 | { |
901 | dump_bb_info (outf: file, bb, indent: 0, flags: flags & TDF_DETAILS, do_header: true, do_footer: true); |
902 | } |
903 | } |
904 | |
905 | /* Set probability of E to NEW_PROB and rescale other edges |
906 | from E->src so their sum remains the same. */ |
907 | |
908 | void |
909 | set_edge_probability_and_rescale_others (edge e, profile_probability new_prob) |
910 | { |
911 | edge e2; |
912 | edge_iterator ei; |
913 | if (e->probability == new_prob) |
914 | return; |
915 | /* If we made E unconditional, drop other frequencies to 0. */ |
916 | if (new_prob == profile_probability::always ()) |
917 | { |
918 | FOR_EACH_EDGE (e2, ei, e->src->succs) |
919 | if (e2 != e) |
920 | e2->probability = profile_probability::never (); |
921 | } |
922 | else |
923 | { |
924 | int n = 0; |
925 | edge other_e = NULL; |
926 | |
927 | /* See how many other edges are leaving exit_edge->src. */ |
928 | FOR_EACH_EDGE (e2, ei, e->src->succs) |
929 | if (e2 != e && !(e2->flags & EDGE_FAKE)) |
930 | { |
931 | other_e = e2; |
932 | n++; |
933 | } |
934 | /* If there is only one other edge with non-zero probability we do not |
935 | need to scale which drops quality of profile from precise |
936 | to adjusted. */ |
937 | if (n == 1) |
938 | other_e->probability = new_prob.invert (); |
939 | /* Nothing to do if there are no other edges. */ |
940 | else if (!n) |
941 | ; |
942 | /* Do scaling if possible. */ |
943 | else if (e->probability.invert ().nonzero_p ()) |
944 | { |
945 | profile_probability num = new_prob.invert (), |
946 | den = e->probability.invert (); |
947 | FOR_EACH_EDGE (e2, ei, e->src->succs) |
948 | if (e2 != e && !(e2->flags & EDGE_FAKE)) |
949 | e2->probability = e2->probability.apply_scale (num, den); |
950 | } |
951 | else |
952 | { |
953 | if (dump_file && (dump_flags & TDF_DETAILS)) |
954 | fprintf (stream: dump_file, |
955 | format: ";; probability of edge %i->%i set reduced from 1." |
956 | " The remaining edges are left inconsistent.\n" , |
957 | e->src->index, e->dest->index); |
958 | FOR_EACH_EDGE (e2, ei, e->src->succs) |
959 | if (e2 != e && !(e2->flags & EDGE_FAKE)) |
960 | e2->probability = new_prob.invert ().guessed () / n; |
961 | } |
962 | } |
963 | e->probability = new_prob; |
964 | } |
965 | |
966 | /* An edge originally destinating BB of COUNT has been proved to |
967 | leave the block by TAKEN_EDGE. Update profile of BB such that edge E can be |
968 | redirected to destination of TAKEN_EDGE. |
969 | |
970 | This function may leave the profile inconsistent in the case TAKEN_EDGE |
971 | frequency or count is believed to be lower than COUNT |
972 | respectively. */ |
973 | void |
974 | update_bb_profile_for_threading (basic_block bb, |
975 | profile_count count, edge taken_edge) |
976 | { |
977 | gcc_assert (bb == taken_edge->src); |
978 | |
979 | /* If there is no profile or the threaded path is never executed |
980 | we don't need to upate. */ |
981 | if (!bb->count.initialized_p () |
982 | || count == profile_count::zero ()) |
983 | return; |
984 | |
985 | if (bb->count < count) |
986 | { |
987 | if (dump_file) |
988 | fprintf (stream: dump_file, format: "bb %i count became negative after threading" , |
989 | bb->index); |
990 | /* If probabilities looks very off, scale down and reduce to guesses |
991 | to avoid dropping the other path close to zero. */ |
992 | if (bb->count < count.apply_scale (num: 7, den: 8)) |
993 | count = bb->count.apply_scale (num: 1, den: 2).guessed (); |
994 | } |
995 | |
996 | /* If bb->count will become zero, the probabilities on the original path |
997 | are not really known, but it is probably better to keep original ones |
998 | then try to invent something new. */ |
999 | if (!(bb->count <= count)) |
1000 | { |
1001 | profile_probability prob; |
1002 | /* Compute the probability of TAKEN_EDGE being reached via threaded edge. |
1003 | Watch for overflows. */ |
1004 | if (bb->count.nonzero_p ()) |
1005 | prob = count.probability_in (overall: bb->count); |
1006 | else |
1007 | prob = taken_edge->probability.apply_scale (num: 1, den: 2).guessed (); |
1008 | if (prob > taken_edge->probability) |
1009 | { |
1010 | if (dump_file) |
1011 | { |
1012 | fprintf (stream: dump_file, format: "Jump threading proved that the probability " |
1013 | "of edge %i->%i was originally estimated too small. " |
1014 | "(it is " , |
1015 | taken_edge->src->index, taken_edge->dest->index); |
1016 | taken_edge->probability.dump (f: dump_file); |
1017 | fprintf (stream: dump_file, format: " should be " ); |
1018 | prob.dump (f: dump_file); |
1019 | fprintf (stream: dump_file, format: ")\n" ); |
1020 | } |
1021 | prob = taken_edge->probability.apply_scale (num: 6, den: 8).guessed (); |
1022 | } |
1023 | set_edge_probability_and_rescale_others (e: taken_edge, |
1024 | new_prob: (taken_edge->probability - prob) |
1025 | / prob.invert ()); |
1026 | } |
1027 | bb->count -= count; |
1028 | } |
1029 | |
1030 | /* Multiply all frequencies of basic blocks in array BBS of length NBBS |
1031 | by NUM/DEN, in profile_count arithmetic. More accurate than previous |
1032 | function but considerably slower. */ |
1033 | void |
1034 | scale_bbs_frequencies_profile_count (basic_block *bbs, int nbbs, |
1035 | profile_count num, profile_count den) |
1036 | { |
1037 | int i; |
1038 | if (num == profile_count::zero () || den.nonzero_p ()) |
1039 | for (i = 0; i < nbbs; i++) |
1040 | bbs[i]->count = bbs[i]->count.apply_scale (num, den); |
1041 | } |
1042 | |
1043 | /* Multiply all frequencies of basic blocks in array BBS of length NBBS |
1044 | by NUM/DEN, in profile_count arithmetic. More accurate than previous |
1045 | function but considerably slower. */ |
1046 | void |
1047 | scale_bbs_frequencies (basic_block *bbs, int nbbs, |
1048 | profile_probability p) |
1049 | { |
1050 | int i; |
1051 | |
1052 | for (i = 0; i < nbbs; i++) |
1053 | bbs[i]->count = bbs[i]->count.apply_probability (prob: p); |
1054 | } |
1055 | |
1056 | /* Data structures used to maintain mapping between basic blocks and |
1057 | copies. */ |
1058 | typedef hash_map<int_hash<int, -1, -2>, int> copy_map_t; |
1059 | static copy_map_t *bb_original; |
1060 | static copy_map_t *bb_copy; |
1061 | |
1062 | /* And between loops and copies. */ |
1063 | static copy_map_t *loop_copy; |
1064 | |
1065 | /* Initialize the data structures to maintain mapping between blocks |
1066 | and its copies. */ |
1067 | void |
1068 | initialize_original_copy_tables (void) |
1069 | { |
1070 | bb_original = new copy_map_t (10); |
1071 | bb_copy = new copy_map_t (10); |
1072 | loop_copy = new copy_map_t (10); |
1073 | } |
1074 | |
1075 | /* Reset the data structures to maintain mapping between blocks and |
1076 | its copies. */ |
1077 | |
1078 | void |
1079 | reset_original_copy_tables (void) |
1080 | { |
1081 | bb_original->empty (); |
1082 | bb_copy->empty (); |
1083 | loop_copy->empty (); |
1084 | } |
1085 | |
1086 | /* Free the data structures to maintain mapping between blocks and |
1087 | its copies. */ |
1088 | void |
1089 | free_original_copy_tables (void) |
1090 | { |
1091 | delete bb_copy; |
1092 | bb_copy = NULL; |
1093 | delete bb_original; |
1094 | bb_original = NULL; |
1095 | delete loop_copy; |
1096 | loop_copy = NULL; |
1097 | } |
1098 | |
1099 | /* Return true iff we have had a call to initialize_original_copy_tables |
1100 | without a corresponding call to free_original_copy_tables. */ |
1101 | |
1102 | bool |
1103 | original_copy_tables_initialized_p (void) |
1104 | { |
1105 | return bb_copy != NULL; |
1106 | } |
1107 | |
1108 | /* Removes the value associated with OBJ from table TAB. */ |
1109 | |
1110 | static void |
1111 | copy_original_table_clear (copy_map_t *tab, unsigned obj) |
1112 | { |
1113 | if (!original_copy_tables_initialized_p ()) |
1114 | return; |
1115 | |
1116 | tab->remove (k: obj); |
1117 | } |
1118 | |
1119 | /* Sets the value associated with OBJ in table TAB to VAL. |
1120 | Do nothing when data structures are not initialized. */ |
1121 | |
1122 | static void |
1123 | copy_original_table_set (copy_map_t *tab, |
1124 | unsigned obj, unsigned val) |
1125 | { |
1126 | if (!original_copy_tables_initialized_p ()) |
1127 | return; |
1128 | |
1129 | tab->put (k: obj, v: val); |
1130 | } |
1131 | |
1132 | /* Set original for basic block. Do nothing when data structures are not |
1133 | initialized so passes not needing this don't need to care. */ |
1134 | void |
1135 | set_bb_original (basic_block bb, basic_block original) |
1136 | { |
1137 | copy_original_table_set (tab: bb_original, obj: bb->index, val: original->index); |
1138 | } |
1139 | |
1140 | /* Get the original basic block. */ |
1141 | basic_block |
1142 | get_bb_original (basic_block bb) |
1143 | { |
1144 | gcc_assert (original_copy_tables_initialized_p ()); |
1145 | |
1146 | int *entry = bb_original->get (k: bb->index); |
1147 | if (entry) |
1148 | return BASIC_BLOCK_FOR_FN (cfun, *entry); |
1149 | else |
1150 | return NULL; |
1151 | } |
1152 | |
1153 | /* Set copy for basic block. Do nothing when data structures are not |
1154 | initialized so passes not needing this don't need to care. */ |
1155 | void |
1156 | set_bb_copy (basic_block bb, basic_block copy) |
1157 | { |
1158 | copy_original_table_set (tab: bb_copy, obj: bb->index, val: copy->index); |
1159 | } |
1160 | |
1161 | /* Get the copy of basic block. */ |
1162 | basic_block |
1163 | get_bb_copy (basic_block bb) |
1164 | { |
1165 | gcc_assert (original_copy_tables_initialized_p ()); |
1166 | |
1167 | int *entry = bb_copy->get (k: bb->index); |
1168 | if (entry) |
1169 | return BASIC_BLOCK_FOR_FN (cfun, *entry); |
1170 | else |
1171 | return NULL; |
1172 | } |
1173 | |
1174 | /* Set copy for LOOP to COPY. Do nothing when data structures are not |
1175 | initialized so passes not needing this don't need to care. */ |
1176 | |
1177 | void |
1178 | set_loop_copy (class loop *loop, class loop *copy) |
1179 | { |
1180 | if (!copy) |
1181 | copy_original_table_clear (tab: loop_copy, obj: loop->num); |
1182 | else |
1183 | copy_original_table_set (tab: loop_copy, obj: loop->num, val: copy->num); |
1184 | } |
1185 | |
1186 | /* Get the copy of LOOP. */ |
1187 | |
1188 | class loop * |
1189 | get_loop_copy (class loop *loop) |
1190 | { |
1191 | gcc_assert (original_copy_tables_initialized_p ()); |
1192 | |
1193 | int *entry = loop_copy->get (k: loop->num); |
1194 | if (entry) |
1195 | return get_loop (cfun, num: *entry); |
1196 | else |
1197 | return NULL; |
1198 | } |
1199 | |
1200 | /* Scales the frequencies of all basic blocks that are strictly |
1201 | dominated by BB by NUM/DEN. */ |
1202 | |
1203 | void |
1204 | scale_strictly_dominated_blocks (basic_block bb, |
1205 | profile_count num, profile_count den) |
1206 | { |
1207 | basic_block son; |
1208 | |
1209 | if (!den.nonzero_p () && !(num == profile_count::zero ())) |
1210 | return; |
1211 | auto_vec <basic_block, 8> worklist; |
1212 | worklist.safe_push (obj: bb); |
1213 | |
1214 | while (!worklist.is_empty ()) |
1215 | for (son = first_dom_son (CDI_DOMINATORS, worklist.pop ()); |
1216 | son; |
1217 | son = next_dom_son (CDI_DOMINATORS, son)) |
1218 | { |
1219 | son->count = son->count.apply_scale (num, den); |
1220 | worklist.safe_push (obj: son); |
1221 | } |
1222 | } |
1223 | |