1 /* Hooks for cfg representation specific functions.
2 Copyright (C) 2003-2014 Free Software Foundation, Inc.
3 Contributed by Sebastian Pop <s.pop@laposte.net>
5 This file is part of GCC.
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 3, or (at your option)
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.
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/>. */
23 #include "coretypes.h"
28 #include "basic-block.h"
31 #include "diagnostic-core.h"
33 #include "pretty-print.h"
35 /* A pointer to one of the hooks containers. */
36 static struct cfg_hooks *cfg_hooks;
38 /* Initialization of functions specific to the rtl IR. */
40 rtl_register_cfg_hooks (void)
42 cfg_hooks = &rtl_cfg_hooks;
45 /* Initialization of functions specific to the rtl IR. */
47 cfg_layout_rtl_register_cfg_hooks (void)
49 cfg_hooks = &cfg_layout_rtl_cfg_hooks;
52 /* Initialization of functions specific to the tree IR. */
55 gimple_register_cfg_hooks (void)
57 cfg_hooks = &gimple_cfg_hooks;
67 set_cfg_hooks (struct cfg_hooks new_cfg_hooks)
69 *cfg_hooks = new_cfg_hooks;
72 /* Returns current ir type. */
75 current_ir_type (void)
77 if (cfg_hooks == &gimple_cfg_hooks)
79 else if (cfg_hooks == &rtl_cfg_hooks)
81 else if (cfg_hooks == &cfg_layout_rtl_cfg_hooks)
82 return IR_RTL_CFGLAYOUT;
87 /* Verify the CFG consistency.
89 Currently it does following: checks edge and basic block list correctness
90 and calls into IL dependent checking then. */
93 verify_flow_info (void)
95 size_t *edge_checksum;
97 basic_block bb, last_bb_seen;
98 basic_block *last_visited;
100 timevar_push (TV_CFG_VERIFY);
101 last_visited = XCNEWVEC (basic_block, last_basic_block_for_fn (cfun));
102 edge_checksum = XCNEWVEC (size_t, last_basic_block_for_fn (cfun));
104 /* Check bb chain & numbers. */
105 last_bb_seen = ENTRY_BLOCK_PTR_FOR_FN (cfun);
106 FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb, NULL, next_bb)
108 if (bb != EXIT_BLOCK_PTR_FOR_FN (cfun)
109 && bb != BASIC_BLOCK_FOR_FN (cfun, bb->index))
111 error ("bb %d on wrong place", bb->index);
115 if (bb->prev_bb != last_bb_seen)
117 error ("prev_bb of %d should be %d, not %d",
118 bb->index, last_bb_seen->index, bb->prev_bb->index);
125 /* Now check the basic blocks (boundaries etc.) */
126 FOR_EACH_BB_REVERSE_FN (bb, cfun)
132 if (bb->loop_father != NULL && current_loops == NULL)
134 error ("verify_flow_info: Block %i has loop_father, but there are no loops",
138 if (bb->loop_father == NULL && current_loops != NULL)
140 error ("verify_flow_info: Block %i lacks loop_father", bb->index);
146 error ("verify_flow_info: Wrong count of block %i %i",
147 bb->index, (int)bb->count);
150 if (bb->frequency < 0)
152 error ("verify_flow_info: Wrong frequency of block %i %i",
153 bb->index, bb->frequency);
156 FOR_EACH_EDGE (e, ei, bb->succs)
158 if (last_visited [e->dest->index] == bb)
160 error ("verify_flow_info: Duplicate edge %i->%i",
161 e->src->index, e->dest->index);
164 if (e->probability < 0 || e->probability > REG_BR_PROB_BASE)
166 error ("verify_flow_info: Wrong probability of edge %i->%i %i",
167 e->src->index, e->dest->index, e->probability);
172 error ("verify_flow_info: Wrong count of edge %i->%i %i",
173 e->src->index, e->dest->index, (int)e->count);
177 last_visited [e->dest->index] = bb;
179 if (e->flags & EDGE_FALLTHRU)
184 error ("verify_flow_info: Basic block %d succ edge is corrupted",
186 fprintf (stderr, "Predecessor: ");
187 dump_edge_info (stderr, e, TDF_DETAILS, 0);
188 fprintf (stderr, "\nSuccessor: ");
189 dump_edge_info (stderr, e, TDF_DETAILS, 1);
190 fprintf (stderr, "\n");
194 edge_checksum[e->dest->index] += (size_t) e;
198 error ("wrong amount of branch edges after unconditional jump %i", bb->index);
202 FOR_EACH_EDGE (e, ei, bb->preds)
206 error ("basic block %d pred edge is corrupted", bb->index);
207 fputs ("Predecessor: ", stderr);
208 dump_edge_info (stderr, e, TDF_DETAILS, 0);
209 fputs ("\nSuccessor: ", stderr);
210 dump_edge_info (stderr, e, TDF_DETAILS, 1);
211 fputc ('\n', stderr);
215 if (ei.index != e->dest_idx)
217 error ("basic block %d pred edge is corrupted", bb->index);
218 error ("its dest_idx should be %d, not %d",
219 ei.index, e->dest_idx);
220 fputs ("Predecessor: ", stderr);
221 dump_edge_info (stderr, e, TDF_DETAILS, 0);
222 fputs ("\nSuccessor: ", stderr);
223 dump_edge_info (stderr, e, TDF_DETAILS, 1);
224 fputc ('\n', stderr);
228 edge_checksum[e->dest->index] -= (size_t) e;
232 /* Complete edge checksumming for ENTRY and EXIT. */
237 FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR_FOR_FN (cfun)->succs)
238 edge_checksum[e->dest->index] += (size_t) e;
240 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
241 edge_checksum[e->dest->index] -= (size_t) e;
244 FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun), NULL, next_bb)
245 if (edge_checksum[bb->index])
247 error ("basic block %i edge lists are corrupted", bb->index);
251 last_bb_seen = ENTRY_BLOCK_PTR_FOR_FN (cfun);
255 free (edge_checksum);
257 if (cfg_hooks->verify_flow_info)
258 err |= cfg_hooks->verify_flow_info ();
260 internal_error ("verify_flow_info failed");
261 timevar_pop (TV_CFG_VERIFY);
264 /* Print out one basic block BB to file OUTF. INDENT is printed at the
265 start of each new line. FLAGS are the TDF_* flags in dumpfile.h.
267 This function takes care of the purely graph related information.
268 The cfg hook for the active representation should dump
269 representation-specific information. */
272 dump_bb (FILE *outf, basic_block bb, int indent, int flags)
274 if (flags & TDF_BLOCKS)
275 dump_bb_info (outf, bb, indent, flags, true, false);
276 if (cfg_hooks->dump_bb)
277 cfg_hooks->dump_bb (outf, bb, indent, flags);
278 if (flags & TDF_BLOCKS)
279 dump_bb_info (outf, bb, indent, flags, false, true);
284 debug (basic_block_def &ref)
286 dump_bb (stderr, &ref, 0, 0);
290 debug (basic_block_def *ptr)
295 fprintf (stderr, "<nil>\n");
299 /* Dumps basic block BB to pretty-printer PP, for use as a label of
300 a DOT graph record-node. The implementation of this hook is
301 expected to write the label to the stream that is attached to PP.
302 Field separators between instructions are pipe characters printed
303 verbatim. Instructions should be written with some characters
304 escaped, using pp_write_text_as_dot_label_to_stream(). */
307 dump_bb_for_graph (pretty_printer *pp, basic_block bb)
309 if (!cfg_hooks->dump_bb_for_graph)
310 internal_error ("%s does not support dump_bb_for_graph",
313 pp_printf (pp, "COUNT:" HOST_WIDEST_INT_PRINT_DEC, bb->count);
314 pp_printf (pp, " FREQ:%i |", bb->frequency);
315 pp_write_text_to_stream (pp);
316 if (!(dump_flags & TDF_SLIM))
317 cfg_hooks->dump_bb_for_graph (pp, bb);
320 /* Dump the complete CFG to FILE. FLAGS are the TDF_* flags in dumpfile.h. */
322 dump_flow_info (FILE *file, int flags)
326 fprintf (file, "\n%d basic blocks, %d edges.\n", n_basic_blocks_for_fn (cfun),
327 n_edges_for_fn (cfun));
328 FOR_ALL_BB_FN (bb, cfun)
329 dump_bb (file, bb, 0, flags);
334 /* Like above, but dump to stderr. To be called from debuggers. */
335 void debug_flow_info (void);
337 debug_flow_info (void)
339 dump_flow_info (stderr, TDF_DETAILS);
342 /* Redirect edge E to the given basic block DEST and update underlying program
343 representation. Returns edge representing redirected branch (that may not
344 be equivalent to E in the case of duplicate edges being removed) or NULL
345 if edge is not easily redirectable for whatever reason. */
348 redirect_edge_and_branch (edge e, basic_block dest)
352 if (!cfg_hooks->redirect_edge_and_branch)
353 internal_error ("%s does not support redirect_edge_and_branch",
356 ret = cfg_hooks->redirect_edge_and_branch (e, dest);
358 /* If RET != E, then either the redirection failed, or the edge E
359 was removed since RET already lead to the same destination. */
360 if (current_loops != NULL && ret == e)
361 rescan_loop_exit (e, false, false);
366 /* Returns true if it is possible to remove the edge E by redirecting it
367 to the destination of the other edge going from its source. */
370 can_remove_branch_p (const_edge e)
372 if (!cfg_hooks->can_remove_branch_p)
373 internal_error ("%s does not support can_remove_branch_p",
376 if (EDGE_COUNT (e->src->succs) != 2)
379 return cfg_hooks->can_remove_branch_p (e);
382 /* Removes E, by redirecting it to the destination of the other edge going
383 from its source. Can_remove_branch_p must be true for E, hence this
384 operation cannot fail. */
387 remove_branch (edge e)
390 basic_block src = e->src;
393 gcc_assert (EDGE_COUNT (e->src->succs) == 2);
395 other = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e);
396 irr = other->flags & EDGE_IRREDUCIBLE_LOOP;
398 e = redirect_edge_and_branch (e, other->dest);
399 gcc_assert (e != NULL);
401 e->flags &= ~EDGE_IRREDUCIBLE_LOOP;
405 /* Removes edge E from cfg. Unlike remove_branch, it does not update IL. */
410 if (current_loops != NULL)
411 rescan_loop_exit (e, false, true);
413 /* This is probably not needed, but it doesn't hurt. */
414 /* FIXME: This should be called via a remove_edge hook. */
415 if (current_ir_type () == IR_GIMPLE)
416 redirect_edge_var_map_clear (e);
421 /* Like redirect_edge_succ but avoid possible duplicate edge. */
424 redirect_edge_succ_nodup (edge e, basic_block new_succ)
428 s = find_edge (e->src, new_succ);
431 s->flags |= e->flags;
432 s->probability += e->probability;
433 if (s->probability > REG_BR_PROB_BASE)
434 s->probability = REG_BR_PROB_BASE;
435 s->count += e->count;
436 /* FIXME: This should be called via a hook and only for IR_GIMPLE. */
437 redirect_edge_var_map_dup (s, e);
442 redirect_edge_succ (e, new_succ);
447 /* Redirect the edge E to basic block DEST even if it requires creating
448 of a new basic block; then it returns the newly created basic block.
449 Aborts when redirection is impossible. */
452 redirect_edge_and_branch_force (edge e, basic_block dest)
454 basic_block ret, src = e->src;
456 if (!cfg_hooks->redirect_edge_and_branch_force)
457 internal_error ("%s does not support redirect_edge_and_branch_force",
460 if (current_loops != NULL)
461 rescan_loop_exit (e, false, true);
463 ret = cfg_hooks->redirect_edge_and_branch_force (e, dest);
465 if (ret != NULL && dom_info_available_p (CDI_DOMINATORS))
466 set_immediate_dominator (CDI_DOMINATORS, ret, src);
468 if (current_loops != NULL)
473 = find_common_loop (single_pred (ret)->loop_father,
474 single_succ (ret)->loop_father);
475 add_bb_to_loop (ret, loop);
477 else if (find_edge (src, dest) == e)
478 rescan_loop_exit (e, true, false);
484 /* Splits basic block BB after the specified instruction I (but at least after
485 the labels). If I is NULL, splits just after labels. The newly created edge
486 is returned. The new basic block is created just after the old one. */
489 split_block (basic_block bb, void *i)
494 if (!cfg_hooks->split_block)
495 internal_error ("%s does not support split_block", cfg_hooks->name);
497 new_bb = cfg_hooks->split_block (bb, i);
501 new_bb->count = bb->count;
502 new_bb->frequency = bb->frequency;
504 if (dom_info_available_p (CDI_DOMINATORS))
506 redirect_immediate_dominators (CDI_DOMINATORS, bb, new_bb);
507 set_immediate_dominator (CDI_DOMINATORS, new_bb, bb);
510 if (current_loops != NULL)
514 add_bb_to_loop (new_bb, bb->loop_father);
515 /* Identify all loops bb may have been the latch of and adjust them. */
516 FOR_EACH_EDGE (e, ei, new_bb->succs)
517 if (e->dest->loop_father->latch == bb)
518 e->dest->loop_father->latch = new_bb;
521 res = make_single_succ_edge (bb, new_bb, EDGE_FALLTHRU);
523 if (bb->flags & BB_IRREDUCIBLE_LOOP)
525 new_bb->flags |= BB_IRREDUCIBLE_LOOP;
526 res->flags |= EDGE_IRREDUCIBLE_LOOP;
532 /* Splits block BB just after labels. The newly created edge is returned. */
535 split_block_after_labels (basic_block bb)
537 return split_block (bb, NULL);
540 /* Moves block BB immediately after block AFTER. Returns false if the
541 movement was impossible. */
544 move_block_after (basic_block bb, basic_block after)
548 if (!cfg_hooks->move_block_after)
549 internal_error ("%s does not support move_block_after", cfg_hooks->name);
551 ret = cfg_hooks->move_block_after (bb, after);
556 /* Deletes the basic block BB. */
559 delete_basic_block (basic_block bb)
561 if (!cfg_hooks->delete_basic_block)
562 internal_error ("%s does not support delete_basic_block", cfg_hooks->name);
564 cfg_hooks->delete_basic_block (bb);
566 if (current_loops != NULL)
568 struct loop *loop = bb->loop_father;
570 /* If we remove the header or the latch of a loop, mark the loop for
571 removal by setting its header and latch to NULL. */
572 if (loop->latch == bb
573 || loop->header == bb)
577 loops_state_set (LOOPS_NEED_FIXUP);
580 remove_bb_from_loops (bb);
583 /* Remove the edges into and out of this block. Note that there may
584 indeed be edges in, if we are removing an unreachable loop. */
585 while (EDGE_COUNT (bb->preds) != 0)
586 remove_edge (EDGE_PRED (bb, 0));
587 while (EDGE_COUNT (bb->succs) != 0)
588 remove_edge (EDGE_SUCC (bb, 0));
590 if (dom_info_available_p (CDI_DOMINATORS))
591 delete_from_dominance_info (CDI_DOMINATORS, bb);
592 if (dom_info_available_p (CDI_POST_DOMINATORS))
593 delete_from_dominance_info (CDI_POST_DOMINATORS, bb);
595 /* Remove the basic block from the array. */
599 /* Splits edge E and returns the newly created basic block. */
605 gcov_type count = e->count;
606 int freq = EDGE_FREQUENCY (e);
608 bool irr = (e->flags & EDGE_IRREDUCIBLE_LOOP) != 0;
610 basic_block src = e->src, dest = e->dest;
612 if (!cfg_hooks->split_edge)
613 internal_error ("%s does not support split_edge", cfg_hooks->name);
615 if (current_loops != NULL)
616 rescan_loop_exit (e, false, true);
618 ret = cfg_hooks->split_edge (e);
620 ret->frequency = freq;
621 single_succ_edge (ret)->probability = REG_BR_PROB_BASE;
622 single_succ_edge (ret)->count = count;
626 ret->flags |= BB_IRREDUCIBLE_LOOP;
627 single_pred_edge (ret)->flags |= EDGE_IRREDUCIBLE_LOOP;
628 single_succ_edge (ret)->flags |= EDGE_IRREDUCIBLE_LOOP;
631 if (dom_info_available_p (CDI_DOMINATORS))
632 set_immediate_dominator (CDI_DOMINATORS, ret, single_pred (ret));
634 if (dom_info_state (CDI_DOMINATORS) >= DOM_NO_FAST_QUERY)
636 /* There are two cases:
638 If the immediate dominator of e->dest is not e->src, it
641 If immediate dominator of e->dest is e->src, it may become
642 ret, provided that all other predecessors of e->dest are
643 dominated by e->dest. */
645 if (get_immediate_dominator (CDI_DOMINATORS, single_succ (ret))
646 == single_pred (ret))
649 FOR_EACH_EDGE (f, ei, single_succ (ret)->preds)
651 if (f == single_succ_edge (ret))
654 if (!dominated_by_p (CDI_DOMINATORS, f->src,
660 set_immediate_dominator (CDI_DOMINATORS, single_succ (ret), ret);
664 if (current_loops != NULL)
666 loop = find_common_loop (src->loop_father, dest->loop_father);
667 add_bb_to_loop (ret, loop);
669 /* If we split the latch edge of loop adjust the latch block. */
670 if (loop->latch == src
671 && loop->header == dest)
678 /* Creates a new basic block just after the basic block AFTER.
679 HEAD and END are the first and the last statement belonging
680 to the block. If both are NULL, an empty block is created. */
683 create_basic_block (void *head, void *end, basic_block after)
687 if (!cfg_hooks->create_basic_block)
688 internal_error ("%s does not support create_basic_block", cfg_hooks->name);
690 ret = cfg_hooks->create_basic_block (head, end, after);
692 if (dom_info_available_p (CDI_DOMINATORS))
693 add_to_dominance_info (CDI_DOMINATORS, ret);
694 if (dom_info_available_p (CDI_POST_DOMINATORS))
695 add_to_dominance_info (CDI_POST_DOMINATORS, ret);
700 /* Creates an empty basic block just after basic block AFTER. */
703 create_empty_bb (basic_block after)
705 return create_basic_block (NULL, NULL, after);
708 /* Checks whether we may merge blocks BB1 and BB2. */
711 can_merge_blocks_p (basic_block bb1, basic_block bb2)
715 if (!cfg_hooks->can_merge_blocks_p)
716 internal_error ("%s does not support can_merge_blocks_p", cfg_hooks->name);
718 ret = cfg_hooks->can_merge_blocks_p (bb1, bb2);
724 predict_edge (edge e, enum br_predictor predictor, int probability)
726 if (!cfg_hooks->predict_edge)
727 internal_error ("%s does not support predict_edge", cfg_hooks->name);
729 cfg_hooks->predict_edge (e, predictor, probability);
733 predicted_by_p (const_basic_block bb, enum br_predictor predictor)
735 if (!cfg_hooks->predict_edge)
736 internal_error ("%s does not support predicted_by_p", cfg_hooks->name);
738 return cfg_hooks->predicted_by_p (bb, predictor);
741 /* Merges basic block B into basic block A. */
744 merge_blocks (basic_block a, basic_block b)
749 if (!cfg_hooks->merge_blocks)
750 internal_error ("%s does not support merge_blocks", cfg_hooks->name);
752 cfg_hooks->merge_blocks (a, b);
754 if (current_loops != NULL)
756 /* If the block we merge into is a loop header do nothing unless ... */
757 if (a->loop_father->header == a)
759 /* ... we merge two loop headers, in which case we kill
761 if (b->loop_father->header == b)
763 b->loop_father->header = NULL;
764 b->loop_father->latch = NULL;
765 loops_state_set (LOOPS_NEED_FIXUP);
768 /* If we merge a loop header into its predecessor, update the loop
770 else if (b->loop_father->header == b)
772 remove_bb_from_loops (a);
773 add_bb_to_loop (a, b->loop_father);
774 a->loop_father->header = a;
776 remove_bb_from_loops (b);
779 /* Normally there should only be one successor of A and that is B, but
780 partway though the merge of blocks for conditional_execution we'll
781 be merging a TEST block with THEN and ELSE successors. Free the
782 whole lot of them and hope the caller knows what they're doing. */
784 while (EDGE_COUNT (a->succs) != 0)
785 remove_edge (EDGE_SUCC (a, 0));
787 /* Adjust the edges out of B for the new owner. */
788 FOR_EACH_EDGE (e, ei, b->succs)
791 if (current_loops != NULL)
793 /* If b was a latch, a now is. */
794 if (e->dest->loop_father->latch == b)
795 e->dest->loop_father->latch = a;
796 rescan_loop_exit (e, true, false);
800 a->flags |= b->flags;
802 /* B hasn't quite yet ceased to exist. Attempt to prevent mishap. */
803 b->preds = b->succs = NULL;
805 if (dom_info_available_p (CDI_DOMINATORS))
806 redirect_immediate_dominators (CDI_DOMINATORS, b, a);
808 if (dom_info_available_p (CDI_DOMINATORS))
809 delete_from_dominance_info (CDI_DOMINATORS, b);
810 if (dom_info_available_p (CDI_POST_DOMINATORS))
811 delete_from_dominance_info (CDI_POST_DOMINATORS, b);
816 /* Split BB into entry part and the rest (the rest is the newly created block).
817 Redirect those edges for that REDIRECT_EDGE_P returns true to the entry
818 part. Returns the edge connecting the entry part to the rest. */
821 make_forwarder_block (basic_block bb, bool (*redirect_edge_p) (edge),
822 void (*new_bb_cbk) (basic_block))
826 basic_block dummy, jump;
827 struct loop *loop, *ploop, *cloop;
829 if (!cfg_hooks->make_forwarder_block)
830 internal_error ("%s does not support make_forwarder_block",
833 fallthru = split_block_after_labels (bb);
834 dummy = fallthru->src;
837 /* Redirect back edges we want to keep. */
838 for (ei = ei_start (dummy->preds); (e = ei_safe_edge (ei)); )
842 if (redirect_edge_p (e))
848 dummy->frequency -= EDGE_FREQUENCY (e);
849 dummy->count -= e->count;
850 if (dummy->frequency < 0)
851 dummy->frequency = 0;
852 if (dummy->count < 0)
854 fallthru->count -= e->count;
855 if (fallthru->count < 0)
859 jump = redirect_edge_and_branch_force (e, bb);
862 /* If we redirected the loop latch edge, the JUMP block now acts like
863 the new latch of the loop. */
864 if (current_loops != NULL
865 && dummy->loop_father != NULL
866 && dummy->loop_father->header == dummy
867 && dummy->loop_father->latch == e_src)
868 dummy->loop_father->latch = jump;
870 if (new_bb_cbk != NULL)
875 if (dom_info_available_p (CDI_DOMINATORS))
877 vec<basic_block> doms_to_fix;
878 doms_to_fix.create (2);
879 doms_to_fix.quick_push (dummy);
880 doms_to_fix.quick_push (bb);
881 iterate_fix_dominators (CDI_DOMINATORS, doms_to_fix, false);
882 doms_to_fix.release ();
885 if (current_loops != NULL)
887 /* If we do not split a loop header, then both blocks belong to the
888 same loop. In case we split loop header and do not redirect the
889 latch edge to DUMMY, then DUMMY belongs to the outer loop, and
890 BB becomes the new header. If latch is not recorded for the loop,
891 we leave this updating on the caller (this may only happen during
893 loop = dummy->loop_father;
894 if (loop->header == dummy
895 && loop->latch != NULL
896 && find_edge (loop->latch, dummy) == NULL)
898 remove_bb_from_loops (dummy);
902 FOR_EACH_EDGE (e, ei, dummy->preds)
904 cloop = find_common_loop (cloop, e->src->loop_father);
906 add_bb_to_loop (dummy, cloop);
909 /* In case we split loop latch, update it. */
910 for (ploop = loop; ploop; ploop = loop_outer (ploop))
911 if (ploop->latch == dummy)
915 cfg_hooks->make_forwarder_block (fallthru);
920 /* Try to make the edge fallthru. */
923 tidy_fallthru_edge (edge e)
925 if (cfg_hooks->tidy_fallthru_edge)
926 cfg_hooks->tidy_fallthru_edge (e);
929 /* Fix up edges that now fall through, or rather should now fall through
930 but previously required a jump around now deleted blocks. Simplify
931 the search by only examining blocks numerically adjacent, since this
932 is how they were created.
934 ??? This routine is currently RTL specific. */
937 tidy_fallthru_edges (void)
941 if (!cfg_hooks->tidy_fallthru_edge)
944 if (ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb == EXIT_BLOCK_PTR_FOR_FN (cfun))
947 FOR_BB_BETWEEN (b, ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb,
948 EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb, next_bb)
954 /* We care about simple conditional or unconditional jumps with
957 If we had a conditional branch to the next instruction when
958 CFG was built, then there will only be one out edge for the
959 block which ended with the conditional branch (since we do
960 not create duplicate edges).
962 Furthermore, the edge will be marked as a fallthru because we
963 merge the flags for the duplicate edges. So we do not want to
964 check that the edge is not a FALLTHRU edge. */
966 if (single_succ_p (b))
968 s = single_succ_edge (b);
969 if (! (s->flags & EDGE_COMPLEX)
971 && !find_reg_note (BB_END (b), REG_CROSSING_JUMP, NULL_RTX))
972 tidy_fallthru_edge (s);
977 /* Edge E is assumed to be fallthru edge. Emit needed jump instruction
978 (and possibly create new basic block) to make edge non-fallthru.
979 Return newly created BB or NULL if none. */
982 force_nonfallthru (edge e)
984 basic_block ret, src = e->src;
986 if (!cfg_hooks->force_nonfallthru)
987 internal_error ("%s does not support force_nonfallthru",
990 ret = cfg_hooks->force_nonfallthru (e);
993 if (dom_info_available_p (CDI_DOMINATORS))
994 set_immediate_dominator (CDI_DOMINATORS, ret, src);
996 if (current_loops != NULL)
999 = find_common_loop (single_pred (ret)->loop_father,
1000 single_succ (ret)->loop_father);
1001 rescan_loop_exit (e, false, true);
1002 add_bb_to_loop (ret, loop);
1009 /* Returns true if we can duplicate basic block BB. */
1012 can_duplicate_block_p (const_basic_block bb)
1014 if (!cfg_hooks->can_duplicate_block_p)
1015 internal_error ("%s does not support can_duplicate_block_p",
1018 if (bb == EXIT_BLOCK_PTR_FOR_FN (cfun) || bb == ENTRY_BLOCK_PTR_FOR_FN (cfun))
1021 return cfg_hooks->can_duplicate_block_p (bb);
1024 /* Duplicates basic block BB and redirects edge E to it. Returns the
1025 new basic block. The new basic block is placed after the basic block
1029 duplicate_block (basic_block bb, edge e, basic_block after)
1033 gcov_type new_count = e ? e->count : 0;
1036 if (!cfg_hooks->duplicate_block)
1037 internal_error ("%s does not support duplicate_block",
1040 if (bb->count < new_count)
1041 new_count = bb->count;
1043 gcc_checking_assert (can_duplicate_block_p (bb));
1045 new_bb = cfg_hooks->duplicate_block (bb);
1047 move_block_after (new_bb, after);
1049 new_bb->flags = bb->flags;
1050 FOR_EACH_EDGE (s, ei, bb->succs)
1052 /* Since we are creating edges from a new block to successors
1053 of another block (which therefore are known to be disjoint), there
1054 is no need to actually check for duplicated edges. */
1055 n = unchecked_make_edge (new_bb, s->dest, s->flags);
1056 n->probability = s->probability;
1059 /* Take care for overflows! */
1060 n->count = s->count * (new_count * 10000 / bb->count) / 10000;
1061 s->count -= n->count;
1064 n->count = s->count;
1070 new_bb->count = new_count;
1071 bb->count -= new_count;
1073 new_bb->frequency = EDGE_FREQUENCY (e);
1074 bb->frequency -= EDGE_FREQUENCY (e);
1076 redirect_edge_and_branch_force (e, new_bb);
1080 if (bb->frequency < 0)
1085 new_bb->count = bb->count;
1086 new_bb->frequency = bb->frequency;
1089 set_bb_original (new_bb, bb);
1090 set_bb_copy (bb, new_bb);
1092 /* Add the new block to the copy of the loop of BB, or directly to the loop
1093 of BB if the loop is not being copied. */
1094 if (current_loops != NULL)
1096 struct loop *cloop = bb->loop_father;
1097 struct loop *copy = get_loop_copy (cloop);
1098 /* If we copied the loop header block but not the loop
1099 we have created a loop with multiple entries. Ditch the loop,
1100 add the new block to the outer loop and arrange for a fixup. */
1102 && cloop->header == bb)
1104 add_bb_to_loop (new_bb, loop_outer (cloop));
1105 cloop->header = NULL;
1106 cloop->latch = NULL;
1107 loops_state_set (LOOPS_NEED_FIXUP);
1111 add_bb_to_loop (new_bb, copy ? copy : cloop);
1112 /* If we copied the loop latch block but not the loop, adjust
1115 && cloop->latch == bb)
1117 cloop->latch = NULL;
1118 loops_state_set (LOOPS_MAY_HAVE_MULTIPLE_LATCHES);
1126 /* Return 1 if BB ends with a call, possibly followed by some
1127 instructions that must stay with the call, 0 otherwise. */
1130 block_ends_with_call_p (basic_block bb)
1132 if (!cfg_hooks->block_ends_with_call_p)
1133 internal_error ("%s does not support block_ends_with_call_p", cfg_hooks->name);
1135 return (cfg_hooks->block_ends_with_call_p) (bb);
1138 /* Return 1 if BB ends with a conditional branch, 0 otherwise. */
1141 block_ends_with_condjump_p (const_basic_block bb)
1143 if (!cfg_hooks->block_ends_with_condjump_p)
1144 internal_error ("%s does not support block_ends_with_condjump_p",
1147 return (cfg_hooks->block_ends_with_condjump_p) (bb);
1150 /* Add fake edges to the function exit for any non constant and non noreturn
1151 calls, volatile inline assembly in the bitmap of blocks specified by
1152 BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks
1155 The goal is to expose cases in which entering a basic block does not imply
1156 that all subsequent instructions must be executed. */
1159 flow_call_edges_add (sbitmap blocks)
1161 if (!cfg_hooks->flow_call_edges_add)
1162 internal_error ("%s does not support flow_call_edges_add",
1165 return (cfg_hooks->flow_call_edges_add) (blocks);
1168 /* This function is called immediately after edge E is added to the
1169 edge vector E->dest->preds. */
1172 execute_on_growing_pred (edge e)
1174 if (cfg_hooks->execute_on_growing_pred)
1175 cfg_hooks->execute_on_growing_pred (e);
1178 /* This function is called immediately before edge E is removed from
1179 the edge vector E->dest->preds. */
1182 execute_on_shrinking_pred (edge e)
1184 if (cfg_hooks->execute_on_shrinking_pred)
1185 cfg_hooks->execute_on_shrinking_pred (e);
1188 /* This is used inside loop versioning when we want to insert
1189 stmts/insns on the edges, which have a different behavior
1190 in tree's and in RTL, so we made a CFG hook. */
1192 lv_flush_pending_stmts (edge e)
1194 if (cfg_hooks->flush_pending_stmts)
1195 cfg_hooks->flush_pending_stmts (e);
1198 /* Loop versioning uses the duplicate_loop_to_header_edge to create
1199 a new version of the loop basic-blocks, the parameters here are
1200 exactly the same as in duplicate_loop_to_header_edge or
1201 tree_duplicate_loop_to_header_edge; while in tree-ssa there is
1202 additional work to maintain ssa information that's why there is
1203 a need to call the tree_duplicate_loop_to_header_edge rather
1204 than duplicate_loop_to_header_edge when we are in tree mode. */
1206 cfg_hook_duplicate_loop_to_header_edge (struct loop *loop, edge e,
1208 sbitmap wont_exit, edge orig,
1209 vec<edge> *to_remove,
1212 gcc_assert (cfg_hooks->cfg_hook_duplicate_loop_to_header_edge);
1213 return cfg_hooks->cfg_hook_duplicate_loop_to_header_edge (loop, e,
1219 /* Conditional jumps are represented differently in trees and RTL,
1220 this hook takes a basic block that is known to have a cond jump
1221 at its end and extracts the taken and not taken edges out of it
1222 and store it in E1 and E2 respectively. */
1224 extract_cond_bb_edges (basic_block b, edge *e1, edge *e2)
1226 gcc_assert (cfg_hooks->extract_cond_bb_edges);
1227 cfg_hooks->extract_cond_bb_edges (b, e1, e2);
1230 /* Responsible for updating the ssa info (PHI nodes) on the
1231 new condition basic block that guards the versioned loop. */
1233 lv_adjust_loop_header_phi (basic_block first, basic_block second,
1234 basic_block new_block, edge e)
1236 if (cfg_hooks->lv_adjust_loop_header_phi)
1237 cfg_hooks->lv_adjust_loop_header_phi (first, second, new_block, e);
1240 /* Conditions in trees and RTL are different so we need
1241 a different handling when we add the condition to the
1244 lv_add_condition_to_bb (basic_block first, basic_block second,
1245 basic_block new_block, void *cond)
1247 gcc_assert (cfg_hooks->lv_add_condition_to_bb);
1248 cfg_hooks->lv_add_condition_to_bb (first, second, new_block, cond);
1251 /* Checks whether all N blocks in BBS array can be copied. */
1253 can_copy_bbs_p (basic_block *bbs, unsigned n)
1259 for (i = 0; i < n; i++)
1260 bbs[i]->flags |= BB_DUPLICATED;
1262 for (i = 0; i < n; i++)
1264 /* In case we should redirect abnormal edge during duplication, fail. */
1266 FOR_EACH_EDGE (e, ei, bbs[i]->succs)
1267 if ((e->flags & EDGE_ABNORMAL)
1268 && (e->dest->flags & BB_DUPLICATED))
1274 if (!can_duplicate_block_p (bbs[i]))
1282 for (i = 0; i < n; i++)
1283 bbs[i]->flags &= ~BB_DUPLICATED;
1288 /* Duplicates N basic blocks stored in array BBS. Newly created basic blocks
1289 are placed into array NEW_BBS in the same order. Edges from basic blocks
1290 in BBS are also duplicated and copies of those that lead into BBS are
1291 redirected to appropriate newly created block. The function assigns bbs
1292 into loops (copy of basic block bb is assigned to bb->loop_father->copy
1293 loop, so this must be set up correctly in advance)
1295 If UPDATE_DOMINANCE is true then this function updates dominators locally
1296 (LOOPS structure that contains the information about dominators is passed
1297 to enable this), otherwise it does not update the dominator information
1298 and it assumed that the caller will do this, perhaps by destroying and
1299 recreating it instead of trying to do an incremental update like this
1300 function does when update_dominance is true.
1302 BASE is the superloop to that basic block belongs; if its header or latch
1303 is copied, we do not set the new blocks as header or latch.
1305 Created copies of N_EDGES edges in array EDGES are stored in array NEW_EDGES,
1306 also in the same order.
1308 Newly created basic blocks are put after the basic block AFTER in the
1309 instruction stream, and the order of the blocks in BBS array is preserved. */
1312 copy_bbs (basic_block *bbs, unsigned n, basic_block *new_bbs,
1313 edge *edges, unsigned num_edges, edge *new_edges,
1314 struct loop *base, basic_block after, bool update_dominance)
1317 basic_block bb, new_bb, dom_bb;
1320 /* Duplicate bbs, update dominators, assign bbs to loops. */
1321 for (i = 0; i < n; i++)
1325 new_bb = new_bbs[i] = duplicate_block (bb, NULL, after);
1327 bb->flags |= BB_DUPLICATED;
1328 if (bb->loop_father)
1330 /* Possibly set loop header. */
1331 if (bb->loop_father->header == bb && bb->loop_father != base)
1332 new_bb->loop_father->header = new_bb;
1334 if (bb->loop_father->latch == bb && bb->loop_father != base)
1335 new_bb->loop_father->latch = new_bb;
1339 /* Set dominators. */
1340 if (update_dominance)
1342 for (i = 0; i < n; i++)
1345 new_bb = new_bbs[i];
1347 dom_bb = get_immediate_dominator (CDI_DOMINATORS, bb);
1348 if (dom_bb->flags & BB_DUPLICATED)
1350 dom_bb = get_bb_copy (dom_bb);
1351 set_immediate_dominator (CDI_DOMINATORS, new_bb, dom_bb);
1356 /* Redirect edges. */
1357 for (j = 0; j < num_edges; j++)
1358 new_edges[j] = NULL;
1359 for (i = 0; i < n; i++)
1362 new_bb = new_bbs[i];
1365 FOR_EACH_EDGE (e, ei, new_bb->succs)
1367 for (j = 0; j < num_edges; j++)
1368 if (edges[j] && edges[j]->src == bb && edges[j]->dest == e->dest)
1371 if (!(e->dest->flags & BB_DUPLICATED))
1373 redirect_edge_and_branch_force (e, get_bb_copy (e->dest));
1377 /* Clear information about duplicates. */
1378 for (i = 0; i < n; i++)
1379 bbs[i]->flags &= ~BB_DUPLICATED;
1382 /* Return true if BB contains only labels or non-executable
1385 empty_block_p (basic_block bb)
1387 gcc_assert (cfg_hooks->empty_block_p);
1388 return cfg_hooks->empty_block_p (bb);
1391 /* Split a basic block if it ends with a conditional branch and if
1392 the other part of the block is not empty. */
1394 split_block_before_cond_jump (basic_block bb)
1396 gcc_assert (cfg_hooks->split_block_before_cond_jump);
1397 return cfg_hooks->split_block_before_cond_jump (bb);
1400 /* Work-horse for passes.c:check_profile_consistency.
1401 Do book-keeping of the CFG for the profile consistency checker.
1402 If AFTER_PASS is 0, do pre-pass accounting, or if AFTER_PASS is 1
1403 then do post-pass accounting. Store the counting in RECORD. */
1406 account_profile_record (struct profile_record *record, int after_pass)
1414 FOR_ALL_BB_FN (bb, cfun)
1416 if (bb != EXIT_BLOCK_PTR_FOR_FN (cfun)
1417 && profile_status_for_fn (cfun) != PROFILE_ABSENT)
1420 FOR_EACH_EDGE (e, ei, bb->succs)
1421 sum += e->probability;
1422 if (EDGE_COUNT (bb->succs) && abs (sum - REG_BR_PROB_BASE) > 100)
1423 record->num_mismatched_freq_out[after_pass]++;
1425 FOR_EACH_EDGE (e, ei, bb->succs)
1427 if (EDGE_COUNT (bb->succs)
1428 && (lsum - bb->count > 100 || lsum - bb->count < -100))
1429 record->num_mismatched_count_out[after_pass]++;
1431 if (bb != ENTRY_BLOCK_PTR_FOR_FN (cfun)
1432 && profile_status_for_fn (cfun) != PROFILE_ABSENT)
1435 FOR_EACH_EDGE (e, ei, bb->preds)
1436 sum += EDGE_FREQUENCY (e);
1437 if (abs (sum - bb->frequency) > 100
1438 || (MAX (sum, bb->frequency) > 10
1439 && abs ((sum - bb->frequency) * 100 / (MAX (sum, bb->frequency) + 1)) > 10))
1440 record->num_mismatched_freq_in[after_pass]++;
1442 FOR_EACH_EDGE (e, ei, bb->preds)
1444 if (lsum - bb->count > 100 || lsum - bb->count < -100)
1445 record->num_mismatched_count_in[after_pass]++;
1447 if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun)
1448 || bb == EXIT_BLOCK_PTR_FOR_FN (cfun))
1450 gcc_assert (cfg_hooks->account_profile_record);
1451 cfg_hooks->account_profile_record (bb, after_pass, record);