1 /* Control flow graph manipulation code for GNU compiler.
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* This file contains low level functions to manipulate the CFG and
23 analyze it. All other modules should not transform the data structure
24 directly and use abstraction instead. The file is supposed to be
25 ordered bottom-up and should not contain any code dependent on a
26 particular intermediate language (RTL or trees).
28 Available functionality:
29 - Initialization/deallocation
30 init_flow, clear_edges
31 - Low level basic block manipulation
32 alloc_block, expunge_block
34 make_edge, make_single_succ_edge, cached_make_edge, remove_edge
35 - Low level edge redirection (without updating instruction chain)
36 redirect_edge_succ, redirect_edge_succ_nodup, redirect_edge_pred
37 - Dumping and debugging
38 dump_flow_info, debug_flow_info, dump_edge_info
39 - Allocation of AUX fields for basic blocks
40 alloc_aux_for_blocks, free_aux_for_blocks, alloc_aux_for_block
42 - Consistency checking
44 - Dumping and debugging
45 print_rtl_with_bb, dump_bb, debug_bb, debug_bb_n
50 #include "coretypes.h"
54 #include "hard-reg-set.h"
64 #include "tree-pass.h"
67 #include "alloc-pool.h"
71 /* The obstack on which the flow graph components are allocated. */
73 struct bitmap_obstack reg_obstack
;
75 void debug_flow_info (void);
76 static void free_edge (edge
);
78 #define RDIV(X,Y) (((X) + (Y) / 2) / (Y))
80 /* Called once at initialization time. */
86 cfun
->cfg
= GGC_CNEW (struct control_flow_graph
);
88 ENTRY_BLOCK_PTR
= GGC_CNEW (struct basic_block_def
);
89 ENTRY_BLOCK_PTR
->index
= ENTRY_BLOCK
;
90 EXIT_BLOCK_PTR
= GGC_CNEW (struct basic_block_def
);
91 EXIT_BLOCK_PTR
->index
= EXIT_BLOCK
;
92 ENTRY_BLOCK_PTR
->next_bb
= EXIT_BLOCK_PTR
;
93 EXIT_BLOCK_PTR
->prev_bb
= ENTRY_BLOCK_PTR
;
96 /* Helper function for remove_edge and clear_edges. Frees edge structure
97 without actually unlinking it from the pred/succ lists. */
100 free_edge (edge e ATTRIBUTE_UNUSED
)
106 /* Free the memory associated with the edge structures. */
117 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
119 VEC_truncate (edge
, bb
->succs
, 0);
120 VEC_truncate (edge
, bb
->preds
, 0);
123 FOR_EACH_EDGE (e
, ei
, ENTRY_BLOCK_PTR
->succs
)
125 VEC_truncate (edge
, EXIT_BLOCK_PTR
->preds
, 0);
126 VEC_truncate (edge
, ENTRY_BLOCK_PTR
->succs
, 0);
128 gcc_assert (!n_edges
);
131 /* Allocate memory for basic_block. */
137 bb
= GGC_CNEW (struct basic_block_def
);
141 /* Link block B to chain after AFTER. */
143 link_block (basic_block b
, basic_block after
)
145 b
->next_bb
= after
->next_bb
;
148 b
->next_bb
->prev_bb
= b
;
151 /* Unlink block B from chain. */
153 unlink_block (basic_block b
)
155 b
->next_bb
->prev_bb
= b
->prev_bb
;
156 b
->prev_bb
->next_bb
= b
->next_bb
;
161 /* Sequentially order blocks and compact the arrays. */
163 compact_blocks (void)
167 SET_BASIC_BLOCK (ENTRY_BLOCK
, ENTRY_BLOCK_PTR
);
168 SET_BASIC_BLOCK (EXIT_BLOCK
, EXIT_BLOCK_PTR
);
171 df_compact_blocks ();
176 i
= NUM_FIXED_BLOCKS
;
179 SET_BASIC_BLOCK (i
, bb
);
183 gcc_assert (i
== n_basic_blocks
);
185 for (; i
< last_basic_block
; i
++)
186 SET_BASIC_BLOCK (i
, NULL
);
188 last_basic_block
= n_basic_blocks
;
191 /* Remove block B from the basic block array. */
194 expunge_block (basic_block b
)
197 SET_BASIC_BLOCK (b
->index
, NULL
);
199 /* We should be able to ggc_free here, but we are not.
200 The dead SSA_NAMES are left pointing to dead statements that are pointing
201 to dead basic blocks making garbage collector to die.
202 We should be able to release all dead SSA_NAMES and at the same time we should
203 clear out BB pointer of dead statements consistently. */
206 /* Connect E to E->src. */
211 VEC_safe_push (edge
, gc
, e
->src
->succs
, e
);
212 df_mark_solutions_dirty ();
215 /* Connect E to E->dest. */
218 connect_dest (edge e
)
220 basic_block dest
= e
->dest
;
221 VEC_safe_push (edge
, gc
, dest
->preds
, e
);
222 e
->dest_idx
= EDGE_COUNT (dest
->preds
) - 1;
223 df_mark_solutions_dirty ();
226 /* Disconnect edge E from E->src. */
229 disconnect_src (edge e
)
231 basic_block src
= e
->src
;
235 for (ei
= ei_start (src
->succs
); (tmp
= ei_safe_edge (ei
)); )
239 VEC_unordered_remove (edge
, src
->succs
, ei
.index
);
246 df_mark_solutions_dirty ();
250 /* Disconnect edge E from E->dest. */
253 disconnect_dest (edge e
)
255 basic_block dest
= e
->dest
;
256 unsigned int dest_idx
= e
->dest_idx
;
258 VEC_unordered_remove (edge
, dest
->preds
, dest_idx
);
260 /* If we removed an edge in the middle of the edge vector, we need
261 to update dest_idx of the edge that moved into the "hole". */
262 if (dest_idx
< EDGE_COUNT (dest
->preds
))
263 EDGE_PRED (dest
, dest_idx
)->dest_idx
= dest_idx
;
264 df_mark_solutions_dirty ();
267 /* Create an edge connecting SRC and DEST with flags FLAGS. Return newly
268 created edge. Use this only if you are sure that this edge can't
269 possibly already exist. */
272 unchecked_make_edge (basic_block src
, basic_block dst
, int flags
)
275 e
= GGC_CNEW (struct edge_def
);
285 execute_on_growing_pred (e
);
289 /* Create an edge connecting SRC and DST with FLAGS optionally using
290 edge cache CACHE. Return the new edge, NULL if already exist. */
293 cached_make_edge (sbitmap edge_cache
, basic_block src
, basic_block dst
, int flags
)
295 if (edge_cache
== NULL
296 || src
== ENTRY_BLOCK_PTR
297 || dst
== EXIT_BLOCK_PTR
)
298 return make_edge (src
, dst
, flags
);
300 /* Does the requested edge already exist? */
301 if (! TEST_BIT (edge_cache
, dst
->index
))
303 /* The edge does not exist. Create one and update the
305 SET_BIT (edge_cache
, dst
->index
);
306 return unchecked_make_edge (src
, dst
, flags
);
309 /* At this point, we know that the requested edge exists. Adjust
310 flags if necessary. */
313 edge e
= find_edge (src
, dst
);
320 /* Create an edge connecting SRC and DEST with flags FLAGS. Return newly
321 created edge or NULL if already exist. */
324 make_edge (basic_block src
, basic_block dest
, int flags
)
326 edge e
= find_edge (src
, dest
);
328 /* Make sure we don't add duplicate edges. */
335 return unchecked_make_edge (src
, dest
, flags
);
338 /* Create an edge connecting SRC to DEST and set probability by knowing
339 that it is the single edge leaving SRC. */
342 make_single_succ_edge (basic_block src
, basic_block dest
, int flags
)
344 edge e
= make_edge (src
, dest
, flags
);
346 e
->probability
= REG_BR_PROB_BASE
;
347 e
->count
= src
->count
;
351 /* This function will remove an edge from the flow graph. */
354 remove_edge_raw (edge e
)
356 remove_predictions_associated_with_edge (e
);
357 execute_on_shrinking_pred (e
);
365 /* Redirect an edge's successor from one block to another. */
368 redirect_edge_succ (edge e
, basic_block new_succ
)
370 execute_on_shrinking_pred (e
);
376 /* Reconnect the edge to the new successor block. */
379 execute_on_growing_pred (e
);
382 /* Like previous but avoid possible duplicate edge. */
385 redirect_edge_succ_nodup (edge e
, basic_block new_succ
)
389 s
= find_edge (e
->src
, new_succ
);
392 s
->flags
|= e
->flags
;
393 s
->probability
+= e
->probability
;
394 if (s
->probability
> REG_BR_PROB_BASE
)
395 s
->probability
= REG_BR_PROB_BASE
;
396 s
->count
+= e
->count
;
401 redirect_edge_succ (e
, new_succ
);
406 /* Redirect an edge's predecessor from one block to another. */
409 redirect_edge_pred (edge e
, basic_block new_pred
)
415 /* Reconnect the edge to the new predecessor block. */
419 /* Clear all basic block flags, with the exception of partitioning and
422 clear_bb_flags (void)
426 FOR_BB_BETWEEN (bb
, ENTRY_BLOCK_PTR
, NULL
, next_bb
)
427 bb
->flags
= (BB_PARTITION (bb
)
428 | (bb
->flags
& (BB_DISABLE_SCHEDULE
+ BB_RTL
+ BB_NON_LOCAL_GOTO_TARGET
)));
431 /* Check the consistency of profile information. We can't do that
432 in verify_flow_info, as the counts may get invalid for incompletely
433 solved graphs, later eliminating of conditionals or roundoff errors.
434 It is still practical to have them reported for debugging of simple
437 check_bb_profile (basic_block bb
, FILE * file
)
444 if (profile_status
== PROFILE_ABSENT
)
447 if (bb
!= EXIT_BLOCK_PTR
)
449 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
450 sum
+= e
->probability
;
451 if (EDGE_COUNT (bb
->succs
) && abs (sum
- REG_BR_PROB_BASE
) > 100)
452 fprintf (file
, "Invalid sum of outgoing probabilities %.1f%%\n",
453 sum
* 100.0 / REG_BR_PROB_BASE
);
455 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
457 if (EDGE_COUNT (bb
->succs
)
458 && (lsum
- bb
->count
> 100 || lsum
- bb
->count
< -100))
459 fprintf (file
, "Invalid sum of outgoing counts %i, should be %i\n",
460 (int) lsum
, (int) bb
->count
);
462 if (bb
!= ENTRY_BLOCK_PTR
)
465 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
466 sum
+= EDGE_FREQUENCY (e
);
467 if (abs (sum
- bb
->frequency
) > 100)
469 "Invalid sum of incoming frequencies %i, should be %i\n",
472 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
474 if (lsum
- bb
->count
> 100 || lsum
- bb
->count
< -100)
475 fprintf (file
, "Invalid sum of incoming counts %i, should be %i\n",
476 (int) lsum
, (int) bb
->count
);
480 /* Write information about registers and basic blocks into FILE.
481 This is part of making a debugging dump. */
484 dump_regset (regset r
, FILE *outf
)
487 reg_set_iterator rsi
;
491 fputs (" (nil)", outf
);
495 EXECUTE_IF_SET_IN_REG_SET (r
, 0, i
, rsi
)
497 fprintf (outf
, " %d", i
);
498 if (i
< FIRST_PSEUDO_REGISTER
)
499 fprintf (outf
, " [%s]",
504 /* Print a human-readable representation of R on the standard error
505 stream. This function is designed to be used from within the
509 debug_regset (regset r
)
511 dump_regset (r
, stderr
);
515 /* Emit basic block information for BB. HEADER is true if the user wants
516 the generic information and the predecessors, FOOTER is true if they want
517 the successors. FLAGS is the dump flags of interest; TDF_DETAILS emit
518 global register liveness information. PREFIX is put in front of every
519 line. The output is emitted to FILE. */
521 dump_bb_info (basic_block bb
, bool header
, bool footer
, int flags
,
522 const char *prefix
, FILE *file
)
529 fprintf (file
, "\n%sBasic block %d ", prefix
, bb
->index
);
531 fprintf (file
, ", prev %d", bb
->prev_bb
->index
);
533 fprintf (file
, ", next %d", bb
->next_bb
->index
);
534 fprintf (file
, ", loop_depth %d, count ", bb
->loop_depth
);
535 fprintf (file
, HOST_WIDEST_INT_PRINT_DEC
, bb
->count
);
536 fprintf (file
, ", freq %i", bb
->frequency
);
537 if (maybe_hot_bb_p (bb
))
538 fprintf (file
, ", maybe hot");
539 if (probably_never_executed_bb_p (bb
))
540 fprintf (file
, ", probably never executed");
541 fprintf (file
, ".\n");
543 fprintf (file
, "%sPredecessors: ", prefix
);
544 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
545 dump_edge_info (file
, e
, 0);
547 if ((flags
& TDF_DETAILS
)
548 && (bb
->flags
& BB_RTL
)
551 fprintf (file
, "\n");
552 df_dump_top (bb
, file
);
558 fprintf (file
, "\n%sSuccessors: ", prefix
);
559 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
560 dump_edge_info (file
, e
, 1);
562 if ((flags
& TDF_DETAILS
)
563 && (bb
->flags
& BB_RTL
)
566 fprintf (file
, "\n");
567 df_dump_bottom (bb
, file
);
574 /* Dump the register info to FILE. */
577 dump_reg_info (FILE *file
)
579 unsigned int i
, max
= max_reg_num ();
580 if (reload_completed
)
583 if (reg_info_p_size
< max
)
584 max
= reg_info_p_size
;
586 fprintf (file
, "%d registers.\n", max
);
587 for (i
= FIRST_PSEUDO_REGISTER
; i
< max
; i
++)
589 enum reg_class
class, altclass
;
591 if (regstat_n_sets_and_refs
)
592 fprintf (file
, "\nRegister %d used %d times across %d insns",
593 i
, REG_N_REFS (i
), REG_LIVE_LENGTH (i
));
595 fprintf (file
, "\nRegister %d used %d times across %d insns",
596 i
, DF_REG_USE_COUNT (i
) + DF_REG_DEF_COUNT (i
), REG_LIVE_LENGTH (i
));
598 if (REG_BASIC_BLOCK (i
) >= NUM_FIXED_BLOCKS
)
599 fprintf (file
, " in block %d", REG_BASIC_BLOCK (i
));
600 if (regstat_n_sets_and_refs
)
601 fprintf (file
, "; set %d time%s", REG_N_SETS (i
),
602 (REG_N_SETS (i
) == 1) ? "" : "s");
604 fprintf (file
, "; set %d time%s", DF_REG_DEF_COUNT (i
),
605 (DF_REG_DEF_COUNT (i
) == 1) ? "" : "s");
606 if (regno_reg_rtx
[i
] != NULL
&& REG_USERVAR_P (regno_reg_rtx
[i
]))
607 fprintf (file
, "; user var");
608 if (REG_N_DEATHS (i
) != 1)
609 fprintf (file
, "; dies in %d places", REG_N_DEATHS (i
));
610 if (REG_N_CALLS_CROSSED (i
) == 1)
611 fprintf (file
, "; crosses 1 call");
612 else if (REG_N_CALLS_CROSSED (i
))
613 fprintf (file
, "; crosses %d calls", REG_N_CALLS_CROSSED (i
));
614 if (regno_reg_rtx
[i
] != NULL
615 && PSEUDO_REGNO_BYTES (i
) != UNITS_PER_WORD
)
616 fprintf (file
, "; %d bytes", PSEUDO_REGNO_BYTES (i
));
618 class = reg_preferred_class (i
);
619 altclass
= reg_alternate_class (i
);
620 if (class != GENERAL_REGS
|| altclass
!= ALL_REGS
)
622 if (altclass
== ALL_REGS
|| class == ALL_REGS
)
623 fprintf (file
, "; pref %s", reg_class_names
[(int) class]);
624 else if (altclass
== NO_REGS
)
625 fprintf (file
, "; %s or none", reg_class_names
[(int) class]);
627 fprintf (file
, "; pref %s, else %s",
628 reg_class_names
[(int) class],
629 reg_class_names
[(int) altclass
]);
632 if (regno_reg_rtx
[i
] != NULL
&& REG_POINTER (regno_reg_rtx
[i
]))
633 fprintf (file
, "; pointer");
634 fprintf (file
, ".\n");
640 dump_flow_info (FILE *file
, int flags
)
644 /* There are no pseudo registers after reload. Don't dump them. */
645 if (reg_info_p_size
&& (flags
& TDF_DETAILS
) != 0)
646 dump_reg_info (file
);
648 fprintf (file
, "\n%d basic blocks, %d edges.\n", n_basic_blocks
, n_edges
);
651 dump_bb_info (bb
, true, true, flags
, "", file
);
652 check_bb_profile (bb
, file
);
659 debug_flow_info (void)
661 dump_flow_info (stderr
, TDF_DETAILS
);
665 dump_edge_info (FILE *file
, edge e
, int do_succ
)
667 basic_block side
= (do_succ
? e
->dest
: e
->src
);
669 if (side
== ENTRY_BLOCK_PTR
)
670 fputs (" ENTRY", file
);
671 else if (side
== EXIT_BLOCK_PTR
)
672 fputs (" EXIT", file
);
674 fprintf (file
, " %d", side
->index
);
677 fprintf (file
, " [%.1f%%] ", e
->probability
* 100.0 / REG_BR_PROB_BASE
);
681 fprintf (file
, " count:");
682 fprintf (file
, HOST_WIDEST_INT_PRINT_DEC
, e
->count
);
687 static const char * const bitnames
[] = {
688 "fallthru", "ab", "abcall", "eh", "fake", "dfs_back",
689 "can_fallthru", "irreducible", "sibcall", "loop_exit",
690 "true", "false", "exec"
693 int i
, flags
= e
->flags
;
696 for (i
= 0; flags
; i
++)
697 if (flags
& (1 << i
))
703 if (i
< (int) ARRAY_SIZE (bitnames
))
704 fputs (bitnames
[i
], file
);
706 fprintf (file
, "%d", i
);
714 /* Simple routines to easily allocate AUX fields of basic blocks. */
716 static struct obstack block_aux_obstack
;
717 static void *first_block_aux_obj
= 0;
718 static struct obstack edge_aux_obstack
;
719 static void *first_edge_aux_obj
= 0;
721 /* Allocate a memory block of SIZE as BB->aux. The obstack must
722 be first initialized by alloc_aux_for_blocks. */
725 alloc_aux_for_block (basic_block bb
, int size
)
727 /* Verify that aux field is clear. */
728 gcc_assert (!bb
->aux
&& first_block_aux_obj
);
729 bb
->aux
= obstack_alloc (&block_aux_obstack
, size
);
730 memset (bb
->aux
, 0, size
);
733 /* Initialize the block_aux_obstack and if SIZE is nonzero, call
734 alloc_aux_for_block for each basic block. */
737 alloc_aux_for_blocks (int size
)
739 static int initialized
;
743 gcc_obstack_init (&block_aux_obstack
);
747 /* Check whether AUX data are still allocated. */
748 gcc_assert (!first_block_aux_obj
);
750 first_block_aux_obj
= obstack_alloc (&block_aux_obstack
, 0);
755 FOR_BB_BETWEEN (bb
, ENTRY_BLOCK_PTR
, NULL
, next_bb
)
756 alloc_aux_for_block (bb
, size
);
760 /* Clear AUX pointers of all blocks. */
763 clear_aux_for_blocks (void)
767 FOR_BB_BETWEEN (bb
, ENTRY_BLOCK_PTR
, NULL
, next_bb
)
771 /* Free data allocated in block_aux_obstack and clear AUX pointers
775 free_aux_for_blocks (void)
777 gcc_assert (first_block_aux_obj
);
778 obstack_free (&block_aux_obstack
, first_block_aux_obj
);
779 first_block_aux_obj
= NULL
;
781 clear_aux_for_blocks ();
784 /* Allocate a memory edge of SIZE as BB->aux. The obstack must
785 be first initialized by alloc_aux_for_edges. */
788 alloc_aux_for_edge (edge e
, int size
)
790 /* Verify that aux field is clear. */
791 gcc_assert (!e
->aux
&& first_edge_aux_obj
);
792 e
->aux
= obstack_alloc (&edge_aux_obstack
, size
);
793 memset (e
->aux
, 0, size
);
796 /* Initialize the edge_aux_obstack and if SIZE is nonzero, call
797 alloc_aux_for_edge for each basic edge. */
800 alloc_aux_for_edges (int size
)
802 static int initialized
;
806 gcc_obstack_init (&edge_aux_obstack
);
810 /* Check whether AUX data are still allocated. */
811 gcc_assert (!first_edge_aux_obj
);
813 first_edge_aux_obj
= obstack_alloc (&edge_aux_obstack
, 0);
818 FOR_BB_BETWEEN (bb
, ENTRY_BLOCK_PTR
, EXIT_BLOCK_PTR
, next_bb
)
823 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
824 alloc_aux_for_edge (e
, size
);
829 /* Clear AUX pointers of all edges. */
832 clear_aux_for_edges (void)
837 FOR_BB_BETWEEN (bb
, ENTRY_BLOCK_PTR
, EXIT_BLOCK_PTR
, next_bb
)
840 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
845 /* Free data allocated in edge_aux_obstack and clear AUX pointers
849 free_aux_for_edges (void)
851 gcc_assert (first_edge_aux_obj
);
852 obstack_free (&edge_aux_obstack
, first_edge_aux_obj
);
853 first_edge_aux_obj
= NULL
;
855 clear_aux_for_edges ();
859 debug_bb (basic_block bb
)
861 dump_bb (bb
, stderr
, 0);
867 basic_block bb
= BASIC_BLOCK (n
);
868 dump_bb (bb
, stderr
, 0);
872 /* Dumps cfg related information about basic block BB to FILE. */
875 dump_cfg_bb_info (FILE *file
, basic_block bb
)
880 static const char * const bb_bitnames
[] =
882 "dirty", "new", "reachable", "visited", "irreducible_loop", "superblock"
884 const unsigned n_bitnames
= sizeof (bb_bitnames
) / sizeof (char *);
887 fprintf (file
, "Basic block %d", bb
->index
);
888 for (i
= 0; i
< n_bitnames
; i
++)
889 if (bb
->flags
& (1 << i
))
892 fprintf (file
, " (");
894 fprintf (file
, ", ");
896 fprintf (file
, bb_bitnames
[i
]);
900 fprintf (file
, "\n");
902 fprintf (file
, "Predecessors: ");
903 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
904 dump_edge_info (file
, e
, 0);
906 fprintf (file
, "\nSuccessors: ");
907 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
908 dump_edge_info (file
, e
, 1);
909 fprintf (file
, "\n\n");
912 /* Dumps a brief description of cfg to FILE. */
915 brief_dump_cfg (FILE *file
)
921 dump_cfg_bb_info (file
, bb
);
925 /* An edge originally destinating BB of FREQUENCY and COUNT has been proved to
926 leave the block by TAKEN_EDGE. Update profile of BB such that edge E can be
927 redirected to destination of TAKEN_EDGE.
929 This function may leave the profile inconsistent in the case TAKEN_EDGE
930 frequency or count is believed to be lower than FREQUENCY or COUNT
933 update_bb_profile_for_threading (basic_block bb
, int edge_frequency
,
934 gcov_type count
, edge taken_edge
)
944 fprintf (dump_file
, "bb %i count became negative after threading",
949 /* Compute the probability of TAKEN_EDGE being reached via threaded edge.
950 Watch for overflows. */
952 prob
= edge_frequency
* REG_BR_PROB_BASE
/ bb
->frequency
;
955 if (prob
> taken_edge
->probability
)
958 fprintf (dump_file
, "Jump threading proved probability of edge "
959 "%i->%i too small (it is %i, should be %i).\n",
960 taken_edge
->src
->index
, taken_edge
->dest
->index
,
961 taken_edge
->probability
, prob
);
962 prob
= taken_edge
->probability
;
965 /* Now rescale the probabilities. */
966 taken_edge
->probability
-= prob
;
967 prob
= REG_BR_PROB_BASE
- prob
;
968 bb
->frequency
-= edge_frequency
;
969 if (bb
->frequency
< 0)
974 fprintf (dump_file
, "Edge frequencies of bb %i has been reset, "
975 "frequency of block should end up being 0, it is %i\n",
976 bb
->index
, bb
->frequency
);
977 EDGE_SUCC (bb
, 0)->probability
= REG_BR_PROB_BASE
;
978 ei
= ei_start (bb
->succs
);
980 for (; (c
= ei_safe_edge (ei
)); ei_next (&ei
))
983 else if (prob
!= REG_BR_PROB_BASE
)
985 int scale
= RDIV (65536 * REG_BR_PROB_BASE
, prob
);
987 FOR_EACH_EDGE (c
, ei
, bb
->succs
)
989 c
->probability
= RDIV (c
->probability
* scale
, 65536);
990 if (c
->probability
> REG_BR_PROB_BASE
)
991 c
->probability
= REG_BR_PROB_BASE
;
995 gcc_assert (bb
== taken_edge
->src
);
996 taken_edge
->count
-= count
;
997 if (taken_edge
->count
< 0)
1000 fprintf (dump_file
, "edge %i->%i count became negative after threading",
1001 taken_edge
->src
->index
, taken_edge
->dest
->index
);
1002 taken_edge
->count
= 0;
1006 /* Multiply all frequencies of basic blocks in array BBS of length NBBS
1007 by NUM/DEN, in int arithmetic. May lose some accuracy. */
1009 scale_bbs_frequencies_int (basic_block
*bbs
, int nbbs
, int num
, int den
)
1016 /* Scale NUM and DEN to avoid overflows. Frequencies are in order of
1017 10^4, if we make DEN <= 10^3, we can afford to upscale by 100
1018 and still safely fit in int during calculations. */
1024 num
= RDIV (1000 * num
, den
);
1027 if (num
> 100 * den
)
1030 for (i
= 0; i
< nbbs
; i
++)
1033 bbs
[i
]->frequency
= RDIV (bbs
[i
]->frequency
* num
, den
);
1034 /* Make sure the frequencies do not grow over BB_FREQ_MAX. */
1035 if (bbs
[i
]->frequency
> BB_FREQ_MAX
)
1036 bbs
[i
]->frequency
= BB_FREQ_MAX
;
1037 bbs
[i
]->count
= RDIV (bbs
[i
]->count
* num
, den
);
1038 FOR_EACH_EDGE (e
, ei
, bbs
[i
]->succs
)
1039 e
->count
= RDIV (e
->count
* num
, den
);
1043 /* numbers smaller than this value are safe to multiply without getting
1045 #define MAX_SAFE_MULTIPLIER (1 << (sizeof (HOST_WIDEST_INT) * 4 - 1))
1047 /* Multiply all frequencies of basic blocks in array BBS of length NBBS
1048 by NUM/DEN, in gcov_type arithmetic. More accurate than previous
1049 function but considerably slower. */
1051 scale_bbs_frequencies_gcov_type (basic_block
*bbs
, int nbbs
, gcov_type num
,
1056 gcov_type fraction
= RDIV (num
* 65536, den
);
1058 gcc_assert (fraction
>= 0);
1060 if (num
< MAX_SAFE_MULTIPLIER
)
1061 for (i
= 0; i
< nbbs
; i
++)
1064 bbs
[i
]->frequency
= RDIV (bbs
[i
]->frequency
* num
, den
);
1065 if (bbs
[i
]->count
<= MAX_SAFE_MULTIPLIER
)
1066 bbs
[i
]->count
= RDIV (bbs
[i
]->count
* num
, den
);
1068 bbs
[i
]->count
= RDIV (bbs
[i
]->count
* fraction
, 65536);
1069 FOR_EACH_EDGE (e
, ei
, bbs
[i
]->succs
)
1070 if (bbs
[i
]->count
<= MAX_SAFE_MULTIPLIER
)
1071 e
->count
= RDIV (e
->count
* num
, den
);
1073 e
->count
= RDIV (e
->count
* fraction
, 65536);
1076 for (i
= 0; i
< nbbs
; i
++)
1079 if (sizeof (gcov_type
) > sizeof (int))
1080 bbs
[i
]->frequency
= RDIV (bbs
[i
]->frequency
* num
, den
);
1082 bbs
[i
]->frequency
= RDIV (bbs
[i
]->frequency
* fraction
, 65536);
1083 bbs
[i
]->count
= RDIV (bbs
[i
]->count
* fraction
, 65536);
1084 FOR_EACH_EDGE (e
, ei
, bbs
[i
]->succs
)
1085 e
->count
= RDIV (e
->count
* fraction
, 65536);
1089 /* Data structures used to maintain mapping between basic blocks and
1091 static htab_t bb_original
;
1092 static htab_t bb_copy
;
1094 /* And between loops and copies. */
1095 static htab_t loop_copy
;
1096 static alloc_pool original_copy_bb_pool
;
1098 struct htab_bb_copy_original_entry
1100 /* Block we are attaching info to. */
1102 /* Index of original or copy (depending on the hashtable) */
1107 bb_copy_original_hash (const void *p
)
1109 const struct htab_bb_copy_original_entry
*data
1110 = ((const struct htab_bb_copy_original_entry
*)p
);
1112 return data
->index1
;
1115 bb_copy_original_eq (const void *p
, const void *q
)
1117 const struct htab_bb_copy_original_entry
*data
1118 = ((const struct htab_bb_copy_original_entry
*)p
);
1119 const struct htab_bb_copy_original_entry
*data2
1120 = ((const struct htab_bb_copy_original_entry
*)q
);
1122 return data
->index1
== data2
->index1
;
1125 /* Initialize the data structures to maintain mapping between blocks
1128 initialize_original_copy_tables (void)
1130 gcc_assert (!original_copy_bb_pool
);
1131 original_copy_bb_pool
1132 = create_alloc_pool ("original_copy",
1133 sizeof (struct htab_bb_copy_original_entry
), 10);
1134 bb_original
= htab_create (10, bb_copy_original_hash
,
1135 bb_copy_original_eq
, NULL
);
1136 bb_copy
= htab_create (10, bb_copy_original_hash
, bb_copy_original_eq
, NULL
);
1137 loop_copy
= htab_create (10, bb_copy_original_hash
, bb_copy_original_eq
, NULL
);
1140 /* Free the data structures to maintain mapping between blocks and
1143 free_original_copy_tables (void)
1145 gcc_assert (original_copy_bb_pool
);
1146 htab_delete (bb_copy
);
1147 htab_delete (bb_original
);
1148 htab_delete (loop_copy
);
1149 free_alloc_pool (original_copy_bb_pool
);
1153 original_copy_bb_pool
= NULL
;
1156 /* Removes the value associated with OBJ from table TAB. */
1159 copy_original_table_clear (htab_t tab
, unsigned obj
)
1162 struct htab_bb_copy_original_entry key
, *elt
;
1164 if (!original_copy_bb_pool
)
1168 slot
= htab_find_slot (tab
, &key
, NO_INSERT
);
1172 elt
= (struct htab_bb_copy_original_entry
*) *slot
;
1173 htab_clear_slot (tab
, slot
);
1174 pool_free (original_copy_bb_pool
, elt
);
1177 /* Sets the value associated with OBJ in table TAB to VAL.
1178 Do nothing when data structures are not initialized. */
1181 copy_original_table_set (htab_t tab
, unsigned obj
, unsigned val
)
1183 struct htab_bb_copy_original_entry
**slot
;
1184 struct htab_bb_copy_original_entry key
;
1186 if (!original_copy_bb_pool
)
1190 slot
= (struct htab_bb_copy_original_entry
**)
1191 htab_find_slot (tab
, &key
, INSERT
);
1194 *slot
= (struct htab_bb_copy_original_entry
*)
1195 pool_alloc (original_copy_bb_pool
);
1196 (*slot
)->index1
= obj
;
1198 (*slot
)->index2
= val
;
1201 /* Set original for basic block. Do nothing when data structures are not
1202 initialized so passes not needing this don't need to care. */
1204 set_bb_original (basic_block bb
, basic_block original
)
1206 copy_original_table_set (bb_original
, bb
->index
, original
->index
);
1209 /* Get the original basic block. */
1211 get_bb_original (basic_block bb
)
1213 struct htab_bb_copy_original_entry
*entry
;
1214 struct htab_bb_copy_original_entry key
;
1216 gcc_assert (original_copy_bb_pool
);
1218 key
.index1
= bb
->index
;
1219 entry
= (struct htab_bb_copy_original_entry
*) htab_find (bb_original
, &key
);
1221 return BASIC_BLOCK (entry
->index2
);
1226 /* Set copy for basic block. Do nothing when data structures are not
1227 initialized so passes not needing this don't need to care. */
1229 set_bb_copy (basic_block bb
, basic_block copy
)
1231 copy_original_table_set (bb_copy
, bb
->index
, copy
->index
);
1234 /* Get the copy of basic block. */
1236 get_bb_copy (basic_block bb
)
1238 struct htab_bb_copy_original_entry
*entry
;
1239 struct htab_bb_copy_original_entry key
;
1241 gcc_assert (original_copy_bb_pool
);
1243 key
.index1
= bb
->index
;
1244 entry
= (struct htab_bb_copy_original_entry
*) htab_find (bb_copy
, &key
);
1246 return BASIC_BLOCK (entry
->index2
);
1251 /* Set copy for LOOP to COPY. Do nothing when data structures are not
1252 initialized so passes not needing this don't need to care. */
1255 set_loop_copy (struct loop
*loop
, struct loop
*copy
)
1258 copy_original_table_clear (loop_copy
, loop
->num
);
1260 copy_original_table_set (loop_copy
, loop
->num
, copy
->num
);
1263 /* Get the copy of LOOP. */
1266 get_loop_copy (struct loop
*loop
)
1268 struct htab_bb_copy_original_entry
*entry
;
1269 struct htab_bb_copy_original_entry key
;
1271 gcc_assert (original_copy_bb_pool
);
1273 key
.index1
= loop
->num
;
1274 entry
= (struct htab_bb_copy_original_entry
*) htab_find (loop_copy
, &key
);
1276 return get_loop (entry
->index2
);