1 /* Calculate branch probabilities, and basic block execution counts.
2 Copyright (C) 1990, 1991, 1992, 1993, 1994, 1996, 1997, 1998, 1999,
3 2000, 2001 Free Software Foundation, Inc.
4 Contributed by James E. Wilson, UC Berkeley/Cygnus Support;
5 based on some ideas from Dain Samples of UC Berkeley.
6 Further mangling by Bob Manson, Cygnus Support.
8 This file is part of GNU CC.
10 GNU CC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 2, or (at your option)
15 GNU CC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GNU CC; see the file COPYING. If not, write to
22 the Free Software Foundation, 59 Temple Place - Suite 330,
23 Boston, MA 02111-1307, USA. */
25 /* ??? Register allocation should use basic block execution counts to
26 give preference to the most commonly executed blocks. */
28 /* ??? The .da files are not safe. Changing the program after creating .da
29 files or using different options when compiling with -fbranch-probabilities
30 can result the arc data not matching the program. Maybe add instrumented
31 arc count to .bbg file? Maybe check whether PFG matches the .bbg file? */
33 /* ??? Should calculate branch probabilities before instrumenting code, since
34 then we can use arc counts to help decide which arcs to instrument. */
41 #include "insn-config.h"
48 #include "hard-reg-set.h"
49 #include "basic-block.h"
52 /* Additional information about the edges we need. */
55 unsigned int count_valid : 1;
56 unsigned int on_tree : 1;
57 unsigned int ignore : 1;
61 unsigned int count_valid : 1;
66 #define EDGE_INFO(e) ((struct edge_info *) (e)->aux)
67 #define BB_INFO(b) ((struct bb_info *) (b)->aux)
69 /* Keep all basic block indexes nonnegative in the gcov output. Index 0
70 is used for entry block, last block exit block. */
71 #define GCOV_INDEX_TO_BB(i) ((i) == 0 ? ENTRY_BLOCK_PTR \
72 : (((i) == n_basic_blocks + 1) \
73 ? EXIT_BLOCK_PTR : BASIC_BLOCK ((i)-1)))
74 #define BB_TO_GCOV_INDEX(bb) ((bb) == ENTRY_BLOCK_PTR ? 0 \
75 : ((bb) == EXIT_BLOCK_PTR \
76 ? n_basic_blocks + 1 : (bb)->index + 1))
78 /* Name and file pointer of the output file for the basic block graph. */
80 static FILE *bbg_file;
82 /* Name and file pointer of the input file for the arc count data. */
86 /* Pointer of the output file for the basic block/line number map. */
89 /* Last source file name written to bb_file. */
91 static char *last_bb_file_name;
93 /* Used by final, for allocating the proper amount of storage for the
94 instrumented arc execution counts. */
96 int count_instrumented_edges;
98 /* Collect statistics on the performance of this pass for the entire source
101 static int total_num_blocks;
102 static int total_num_edges;
103 static int total_num_edges_ignored;
104 static int total_num_edges_instrumented;
105 static int total_num_blocks_created;
106 static int total_num_passes;
107 static int total_num_times_called;
108 static int total_hist_br_prob[20];
109 static int total_num_never_executed;
110 static int total_num_branches;
112 /* Forward declarations. */
113 static void find_spanning_tree PARAMS ((struct edge_list *));
114 static void init_edge_profiler PARAMS ((void));
115 static rtx gen_edge_profiler PARAMS ((int));
116 static void instrument_edges PARAMS ((struct edge_list *));
117 static void output_gcov_string PARAMS ((const char *, long));
118 static void compute_branch_probabilities PARAMS ((void));
119 static basic_block find_group PARAMS ((basic_block));
120 static void union_groups PARAMS ((basic_block, basic_block));
122 /* If non-zero, we need to output a constructor to set up the
123 per-object-file data. */
124 static int need_func_profiler = 0;
126 /* Add edge instrumentation code to the entire insn chain.
128 F is the first insn of the chain.
129 NUM_BLOCKS is the number of basic blocks found in F. */
132 instrument_edges (el)
133 struct edge_list *el;
136 int num_instr_edges = 0;
137 int num_edges = NUM_EDGES (el);
138 remove_fake_edges ();
140 for (i = 0; i < n_basic_blocks + 2; i++)
142 basic_block bb = GCOV_INDEX_TO_BB (i);
146 struct edge_info *inf = EDGE_INFO (e);
147 if (!inf->ignore && !inf->on_tree)
149 if (e->flags & EDGE_ABNORMAL)
152 fprintf (rtl_dump_file, "Edge %d to %d instrumented%s\n",
153 e->src->index, e->dest->index,
154 e->flags & EDGE_CRITICAL ? " (and split)" : "");
155 need_func_profiler = 1;
156 insert_insn_on_edge (
157 gen_edge_profiler (total_num_edges_instrumented
158 + num_instr_edges++), e);
164 total_num_edges_instrumented += num_instr_edges;
165 count_instrumented_edges = total_num_edges_instrumented;
167 total_num_blocks_created += num_edges;
169 fprintf (rtl_dump_file, "%d edges instrumented\n", num_instr_edges);
171 commit_edge_insertions ();
174 /* Output STRING to bb_file, surrounded by DELIMITER. */
177 output_gcov_string (string, delimiter)
183 /* Write a delimiter to indicate that a file name follows. */
184 __write_long (delimiter, bb_file, 4);
186 /* Write the string. */
187 temp = strlen (string) + 1;
188 fwrite (string, temp, 1, bb_file);
190 /* Append a few zeros, to align the output to a 4 byte boundary. */
196 c[0] = c[1] = c[2] = c[3] = 0;
197 fwrite (c, sizeof (char), 4 - temp, bb_file);
200 /* Store another delimiter in the .bb file, just to make it easy to find
201 the end of the file name. */
202 __write_long (delimiter, bb_file, 4);
206 /* Compute the branch probabilities for the various branches.
207 Annotate them accordingly. */
210 compute_branch_probabilities ()
216 int hist_br_prob[20];
217 int num_never_executed;
219 struct bb_info *bb_infos;
221 /* Attach extra info block to each bb. */
223 bb_infos = (struct bb_info *)
224 xcalloc (n_basic_blocks + 2, sizeof (struct bb_info));
225 for (i = 0; i < n_basic_blocks + 2; i++)
227 basic_block bb = GCOV_INDEX_TO_BB (i);
230 bb->aux = &bb_infos[i];
231 for (e = bb->succ; e; e = e->succ_next)
232 if (!EDGE_INFO (e)->ignore)
233 BB_INFO (bb)->succ_count++;
234 for (e = bb->pred; e; e = e->pred_next)
235 if (!EDGE_INFO (e)->ignore)
236 BB_INFO (bb)->pred_count++;
239 /* Avoid predicting entry on exit nodes. */
240 BB_INFO (EXIT_BLOCK_PTR)->succ_count = 2;
241 BB_INFO (ENTRY_BLOCK_PTR)->pred_count = 2;
243 /* For each edge not on the spanning tree, set its execution count from
246 /* The first count in the .da file is the number of times that the function
247 was entered. This is the exec_count for block zero. */
249 for (i = 0; i < n_basic_blocks + 2; i++)
251 basic_block bb = GCOV_INDEX_TO_BB (i);
253 for (e = bb->succ; e; e = e->succ_next)
254 if (!EDGE_INFO (e)->ignore && !EDGE_INFO (e)->on_tree)
260 __read_gcov_type (&value, da_file, 8);
265 EDGE_INFO (e)->count_valid = 1;
266 BB_INFO (bb)->succ_count--;
267 BB_INFO (e->dest)->pred_count--;
270 fprintf (rtl_dump_file, "\nRead edge from %i to %i, count:",
271 bb->index, e->dest->index);
272 fprintf (rtl_dump_file, HOST_WIDEST_INT_PRINT_DEC,
273 (HOST_WIDEST_INT) e->count);
279 fprintf (rtl_dump_file, "\n%d edge counts read\n", num_edges);
281 /* For every block in the file,
282 - if every exit/entrance edge has a known count, then set the block count
283 - if the block count is known, and every exit/entrance edge but one has
284 a known execution count, then set the count of the remaining edge
286 As edge counts are set, decrement the succ/pred count, but don't delete
287 the edge, that way we can easily tell when all edges are known, or only
288 one edge is unknown. */
290 /* The order that the basic blocks are iterated through is important.
291 Since the code that finds spanning trees starts with block 0, low numbered
292 edges are put on the spanning tree in preference to high numbered edges.
293 Hence, most instrumented edges are at the end. Graph solving works much
294 faster if we propagate numbers from the end to the start.
296 This takes an average of slightly more than 3 passes. */
304 for (i = n_basic_blocks + 1; i >= 0; i--)
306 basic_block bb = GCOV_INDEX_TO_BB (i);
307 struct bb_info *bi = BB_INFO (bb);
308 if (! bi->count_valid)
310 if (bi->succ_count == 0)
315 for (e = bb->succ; e; e = e->succ_next)
321 else if (bi->pred_count == 0)
326 for (e = bb->pred; e; e = e->pred_next)
335 if (bi->succ_count == 1)
340 /* One of the counts will be invalid, but it is zero,
341 so adding it in also doesn't hurt. */
342 for (e = bb->succ; e; e = e->succ_next)
345 /* Seedgeh for the invalid edge, and set its count. */
346 for (e = bb->succ; e; e = e->succ_next)
347 if (! EDGE_INFO (e)->count_valid && ! EDGE_INFO (e)->ignore)
350 /* Calculate count for remaining edge by conservation. */
351 total = bb->count - total;
355 EDGE_INFO (e)->count_valid = 1;
359 BB_INFO (e->dest)->pred_count--;
362 if (bi->pred_count == 1)
367 /* One of the counts will be invalid, but it is zero,
368 so adding it in also doesn't hurt. */
369 for (e = bb->pred; e; e = e->pred_next)
372 /* Seedgeh for the invalid edge, and set its count. */
373 for (e = bb->pred; e; e = e->pred_next)
374 if (! EDGE_INFO (e)->count_valid && ! EDGE_INFO (e)->ignore)
377 /* Calculate count for remaining edge by conservation. */
378 total = bb->count - total + e->count;
382 EDGE_INFO (e)->count_valid = 1;
386 BB_INFO (e->src)->succ_count--;
393 dump_flow_info (rtl_dump_file);
395 total_num_passes += passes;
397 fprintf (rtl_dump_file, "Graph solving took %d passes.\n\n", passes);
399 /* If the graph has been correctly solved, every block will have a
400 succ and pred count of zero. */
401 for (i = 0; i < n_basic_blocks; i++)
403 basic_block bb = BASIC_BLOCK (i);
404 if (BB_INFO (bb)->succ_count || BB_INFO (bb)->pred_count)
408 /* For every edge, calculate its branch probability and add a reg_note
409 to the branch insn to indicate this. */
411 for (i = 0; i < 20; i++)
413 num_never_executed = 0;
416 for (i = 0; i < n_basic_blocks; i++)
418 basic_block bb = BASIC_BLOCK (i);
425 for (e = bb->succ; e; e = e->succ_next)
427 e->probability = (e->count * REG_BR_PROB_BASE + total / 2) / total;
428 if (e->probability < 0 || e->probability > REG_BR_PROB_BASE)
430 error ("Corrupted profile info: prob for %d-%d thought to be %d\n",
431 e->src->index, e->dest->index, e->probability);
432 e->probability = REG_BR_PROB_BASE / 2;
435 if (any_condjump_p (bb->end)
436 && bb->succ->succ_next)
445 num_never_executed++;
450 /* Find the branch edge. It is possible that we do have fake
452 for (e = bb->succ; e->flags & (EDGE_FAKE | EDGE_FALLTHRU);
454 continue; /* Loop body has been intentionally left blank. */
456 prob = e->probability;
457 index = prob * 20 / REG_BR_PROB_BASE;
461 hist_br_prob[index]++;
463 note = find_reg_note (bb->end, REG_BR_PROB, 0);
464 /* There may be already note put by some other pass, such
465 as builtin_expect expander. */
467 XEXP (note, 0) = GEN_INT (prob);
470 = gen_rtx_EXPR_LIST (REG_BR_PROB, GEN_INT (prob),
471 REG_NOTES (bb->end));
480 fprintf (rtl_dump_file, "%d branches\n", num_branches);
481 fprintf (rtl_dump_file, "%d branches never executed\n",
484 for (i = 0; i < 10; i++)
485 fprintf (rtl_dump_file, "%d%% branches in range %d-%d%%\n",
486 (hist_br_prob[i] + hist_br_prob[19-i]) * 100 / num_branches,
489 total_num_branches += num_branches;
490 total_num_never_executed += num_never_executed;
491 for (i = 0; i < 20; i++)
492 total_hist_br_prob[i] += hist_br_prob[i];
494 fputc ('\n', rtl_dump_file);
495 fputc ('\n', rtl_dump_file);
501 /* Instrument and/or analyze program behavior based on program flow graph.
502 In either case, this function builds a flow graph for the function being
503 compiled. The flow graph is stored in BB_GRAPH.
505 When FLAG_PROFILE_ARCS is nonzero, this function instruments the edges in
506 the flow graph that are needed to reconstruct the dynamic behavior of the
509 When FLAG_BRANCH_PROBABILITIES is nonzero, this function reads auxiliary
510 information from a data file containing edge count information from previous
511 executions of the function being compiled. In this case, the flow graph is
512 annotated with actual execution counts, which are later propagated into the
513 rtl for optimization purposes.
515 Main entry point of this file. */
521 int num_edges, ignored_edges;
522 struct edge_info *edge_infos;
523 struct edge_list *el;
525 /* Start of a function. */
526 if (flag_test_coverage)
527 output_gcov_string (current_function_name, (long) -2);
529 total_num_times_called++;
531 flow_call_edges_add (NULL);
533 /* We can't handle cyclic regions constructed using abnormal edges.
534 To avoid these we replace every source of abnormal edge by a fake
535 edge from entry node and every destination by fake edge to exit.
536 This keeps graph acyclic and our calculation exact for all normal
537 edges except for exit and entrance ones.
539 We also add fake exit edges for each call and asm statement in the
540 basic, since it may not return. */
542 for (i = 0; i < n_basic_blocks ; i++)
544 int need_exit_edge = 0, need_entry_edge = 0;
545 int have_exit_edge = 0, have_entry_edge = 0;
546 basic_block bb = BASIC_BLOCK (i);
550 /* Add fake edges from entry block to the call insns that may return
551 twice. The CFG is not quite correct then, as call insn plays more
552 role of CODE_LABEL, but for our purposes, everything should be OK,
553 as we never insert code to the beggining of basic block. */
554 for (insn = bb->head; insn != NEXT_INSN (bb->end);
555 insn = NEXT_INSN (insn))
557 if (GET_CODE (insn) == CALL_INSN
558 && find_reg_note (insn, REG_SETJMP, NULL))
560 if (GET_CODE (bb->head) == CODE_LABEL
561 || insn != NEXT_INSN (bb->head))
563 e = split_block (bb, PREV_INSN (insn));
564 make_edge (NULL, ENTRY_BLOCK_PTR, e->dest, EDGE_FAKE);
569 /* We should not get abort here, as call to setjmp should not
570 be the very first instruction of function. */
573 make_edge (NULL, ENTRY_BLOCK_PTR, bb, EDGE_FAKE);
578 for (e = bb->succ; e; e = e->succ_next)
580 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
581 && e->dest != EXIT_BLOCK_PTR)
583 if (e->dest == EXIT_BLOCK_PTR)
586 for (e = bb->pred; e; e = e->pred_next)
588 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
589 && e->src != ENTRY_BLOCK_PTR)
591 if (e->src == ENTRY_BLOCK_PTR)
595 if (need_exit_edge && !have_exit_edge)
598 fprintf (rtl_dump_file, "Adding fake exit edge to bb %i\n",
600 make_edge (NULL, bb, EXIT_BLOCK_PTR, EDGE_FAKE);
602 if (need_entry_edge && !have_entry_edge)
605 fprintf (rtl_dump_file, "Adding fake entry edge to bb %i\n",
607 make_edge (NULL, ENTRY_BLOCK_PTR, bb, EDGE_FAKE);
611 el = create_edge_list ();
612 num_edges = NUM_EDGES (el);
613 edge_infos = (struct edge_info *)
614 xcalloc (num_edges, sizeof (struct edge_info));
617 for (i = 0 ; i < num_edges ; i++)
619 edge e = INDEX_EDGE (el, i);
621 e->aux = &edge_infos[i];
623 /* Mark edges we've replaced by fake edges above as ignored. */
624 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
625 && e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR)
627 EDGE_INFO (e)->ignore = 1;
632 #ifdef ENABLE_CHECKING
636 /* Output line number information about each basic block for
638 if (flag_test_coverage)
641 for (i = 0 ; i < n_basic_blocks; i++)
643 basic_block bb = BASIC_BLOCK (i);
645 static int ignore_next_note = 0;
647 /* We are looking for line number notes. Search backward before
648 basic block to find correct ones. */
649 insn = prev_nonnote_insn (insn);
653 insn = NEXT_INSN (insn);
655 /* Output a zero to the .bb file to indicate that a new
656 block list is starting. */
657 __write_long (0, bb_file, 4);
659 while (insn != bb->end)
661 if (GET_CODE (insn) == NOTE)
663 /* Must ignore the line number notes that immediately
664 follow the end of an inline function to avoid counting
665 it twice. There is a note before the call, and one
667 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_REPEATED_LINE_NUMBER)
668 ignore_next_note = 1;
669 else if (NOTE_LINE_NUMBER (insn) > 0)
671 if (ignore_next_note)
672 ignore_next_note = 0;
675 /* If this is a new source file, then output the
676 file's name to the .bb file. */
677 if (! last_bb_file_name
678 || strcmp (NOTE_SOURCE_FILE (insn),
681 if (last_bb_file_name)
682 free (last_bb_file_name);
684 = xstrdup (NOTE_SOURCE_FILE (insn));
685 output_gcov_string (NOTE_SOURCE_FILE (insn),
688 /* Output the line number to the .bb file. Must be
689 done after the output_bb_profile_data() call, and
690 after the file name is written, to ensure that it
691 is correctly handled by gcov. */
692 __write_long (NOTE_LINE_NUMBER (insn), bb_file, 4);
696 insn = NEXT_INSN (insn);
699 __write_long (0, bb_file, 4);
702 /* Create spanning tree from basic block graph, mark each edge that is
703 on the spanning tree. We insert as many abnormal and critical edges
704 as possible to minimize number of edge splits necesary. */
706 find_spanning_tree (el);
708 /* Fake edges that are not on the tree will not be instrumented, so
709 mark them ignored. */
710 for (i = 0; i < num_edges; i++)
712 edge e = INDEX_EDGE (el, i);
713 struct edge_info *inf = EDGE_INFO (e);
714 if ((e->flags & EDGE_FAKE) && !inf->ignore && !inf->on_tree)
721 total_num_blocks += n_basic_blocks + 2;
723 fprintf (rtl_dump_file, "%d basic blocks\n", n_basic_blocks);
725 total_num_edges += num_edges;
727 fprintf (rtl_dump_file, "%d edges\n", num_edges);
729 total_num_edges_ignored += ignored_edges;
731 fprintf (rtl_dump_file, "%d ignored edges\n", ignored_edges);
733 /* Create a .bbg file from which gcov can reconstruct the basic block
734 graph. First output the number of basic blocks, and then for every
735 edge output the source and target basic block numbers.
736 NOTE: The format of this file must be compatible with gcov. */
738 if (flag_test_coverage)
742 /* The plus 2 stands for entry and exit block. */
743 __write_long (n_basic_blocks + 2, bbg_file, 4);
744 __write_long (num_edges - ignored_edges + 1, bbg_file, 4);
746 for (i = 0; i < n_basic_blocks + 1; i++)
748 basic_block bb = GCOV_INDEX_TO_BB (i);
752 for (e = bb->succ; e; e = e->succ_next)
753 if (!EDGE_INFO (e)->ignore)
755 __write_long (count, bbg_file, 4);
757 for (e = bb->succ; e; e = e->succ_next)
759 struct edge_info *i = EDGE_INFO (e);
765 if (e->flags & EDGE_FAKE)
767 if (e->flags & EDGE_FALLTHRU)
770 __write_long (BB_TO_GCOV_INDEX (e->dest), bbg_file, 4);
771 __write_long (flag_bits, bbg_file, 4);
775 /* Emit fake loopback edge for EXIT block to maitain compatibility with
777 __write_long (1, bbg_file, 4);
778 __write_long (0, bbg_file, 4);
779 __write_long (0x1, bbg_file, 4);
781 /* Emit a -1 to separate the list of all edges from the list of
782 loop back edges that follows. */
783 __write_long (-1, bbg_file, 4);
786 if (flag_branch_probabilities)
787 compute_branch_probabilities ();
789 /* For each edge not on the spanning tree, add counting code as rtl. */
791 if (profile_arc_flag)
793 instrument_edges (el);
794 allocate_reg_info (max_reg_num (), FALSE, FALSE);
797 remove_fake_edges ();
798 /* Re-merge split basic blocks and the mess introduced by
799 insert_insn_on_edge. */
800 cleanup_cfg (profile_arc_flag ? CLEANUP_EXPENSIVE : 0);
802 dump_flow_info (rtl_dump_file);
808 /* Union find algorithm implementation for the basic blocks using
815 basic_block group = bb, bb1;
817 while ((basic_block) group->aux != group)
818 group = (basic_block) group->aux;
821 while ((basic_block) bb->aux != group)
823 bb1 = (basic_block) bb->aux;
824 bb->aux = (void *) group;
831 union_groups (bb1, bb2)
832 basic_block bb1, bb2;
834 basic_block bb1g = find_group (bb1);
835 basic_block bb2g = find_group (bb2);
837 /* ??? I don't have a place for the rank field. OK. Lets go w/o it,
838 this code is unlikely going to be performance problem anyway. */
845 /* This function searches all of the edges in the program flow graph, and puts
846 as many bad edges as possible onto the spanning tree. Bad edges include
847 abnormals edges, which can't be instrumented at the moment. Since it is
848 possible for fake edges to form an cycle, we will have to develop some
849 better way in the future. Also put critical edges to the tree, since they
850 are more expensive to instrument. */
853 find_spanning_tree (el)
854 struct edge_list *el;
857 int num_edges = NUM_EDGES (el);
859 /* We use aux field for standard union-find algorithm. */
860 EXIT_BLOCK_PTR->aux = EXIT_BLOCK_PTR;
861 ENTRY_BLOCK_PTR->aux = ENTRY_BLOCK_PTR;
862 for (i = 0; i < n_basic_blocks; i++)
863 BASIC_BLOCK (i)->aux = BASIC_BLOCK (i);
865 /* Add fake edge exit to entry we can't instrument. */
866 union_groups (EXIT_BLOCK_PTR, ENTRY_BLOCK_PTR);
868 /* First add all abnormal edges to the tree unless they form an cycle. */
869 for (i = 0; i < num_edges; i++)
871 edge e = INDEX_EDGE (el, i);
872 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_FAKE))
873 && !EDGE_INFO (e)->ignore
874 && (find_group (e->src) != find_group (e->dest)))
876 EDGE_INFO (e)->on_tree = 1;
877 union_groups (e->src, e->dest);
881 /* Now insert all critical edges to the tree unless they form an cycle. */
882 for (i = 0; i < num_edges; i++)
884 edge e = INDEX_EDGE (el, i);
885 if ((e->flags & EDGE_CRITICAL)
886 && !EDGE_INFO (e)->ignore
887 && (find_group (e->src) != find_group (e->dest)))
889 EDGE_INFO (e)->on_tree = 1;
890 union_groups (e->src, e->dest);
894 /* And now the rest. */
895 for (i = 0; i < num_edges; i++)
897 edge e = INDEX_EDGE (el, i);
898 if (find_group (e->src) != find_group (e->dest)
899 && !EDGE_INFO (e)->ignore)
901 EDGE_INFO (e)->on_tree = 1;
902 union_groups (e->src, e->dest);
907 /* Perform file-level initialization for branch-prob processing. */
910 init_branch_prob (filename)
911 const char *filename;
916 if (flag_test_coverage)
918 int len = strlen (filename);
919 char *data_file, *bbg_file_name;
921 /* Open an output file for the basic block/line number map. */
922 data_file = (char *) alloca (len + 4);
923 strcpy (data_file, filename);
924 strip_off_ending (data_file, len);
925 strcat (data_file, ".bb");
926 if ((bb_file = fopen (data_file, "wb")) == 0)
927 fatal_io_error ("can't open %s", data_file);
929 /* Open an output file for the program flow graph. */
930 bbg_file_name = (char *) alloca (len + 5);
931 strcpy (bbg_file_name, filename);
932 strip_off_ending (bbg_file_name, len);
933 strcat (bbg_file_name, ".bbg");
934 if ((bbg_file = fopen (bbg_file_name, "wb")) == 0)
935 fatal_io_error ("can't open %s", bbg_file_name);
937 /* Initialize to zero, to ensure that the first file name will be
938 written to the .bb file. */
939 last_bb_file_name = 0;
942 if (flag_branch_probabilities)
946 len = strlen (filename);
947 da_file_name = (char *) alloca (len + 4);
948 strcpy (da_file_name, filename);
949 strip_off_ending (da_file_name, len);
950 strcat (da_file_name, ".da");
951 if ((da_file = fopen (da_file_name, "rb")) == 0)
952 warning ("file %s not found, execution counts assumed to be zero.",
955 /* The first word in the .da file gives the number of instrumented
956 edges, which is not needed for our purposes. */
959 __read_long (&len, da_file, 8);
962 if (profile_arc_flag)
963 init_edge_profiler ();
965 total_num_blocks = 0;
967 total_num_edges_ignored = 0;
968 total_num_edges_instrumented = 0;
969 total_num_blocks_created = 0;
970 total_num_passes = 0;
971 total_num_times_called = 0;
972 total_num_branches = 0;
973 total_num_never_executed = 0;
974 for (i = 0; i < 20; i++)
975 total_hist_br_prob[i] = 0;
978 /* Performs file-level cleanup after branch-prob processing
984 if (flag_test_coverage)
990 if (flag_branch_probabilities)
995 /* This seems slightly dangerous, as it presumes the EOF
996 flag will not be set until an attempt is made to read
997 past the end of the file. */
999 error (".da file contents exhausted too early");
1000 /* Should be at end of file now. */
1001 if (__read_long (&temp, da_file, 8) == 0)
1002 error (".da file contents not exhausted");
1009 fprintf (rtl_dump_file, "\n");
1010 fprintf (rtl_dump_file, "Total number of blocks: %d\n",
1012 fprintf (rtl_dump_file, "Total number of edges: %d\n", total_num_edges);
1013 fprintf (rtl_dump_file, "Total number of ignored edges: %d\n",
1014 total_num_edges_ignored);
1015 fprintf (rtl_dump_file, "Total number of instrumented edges: %d\n",
1016 total_num_edges_instrumented);
1017 fprintf (rtl_dump_file, "Total number of blocks created: %d\n",
1018 total_num_blocks_created);
1019 fprintf (rtl_dump_file, "Total number of graph solution passes: %d\n",
1021 if (total_num_times_called != 0)
1022 fprintf (rtl_dump_file, "Average number of graph solution passes: %d\n",
1023 (total_num_passes + (total_num_times_called >> 1))
1024 / total_num_times_called);
1025 fprintf (rtl_dump_file, "Total number of branches: %d\n",
1026 total_num_branches);
1027 fprintf (rtl_dump_file, "Total number of branches never executed: %d\n",
1028 total_num_never_executed);
1029 if (total_num_branches)
1033 for (i = 0; i < 10; i++)
1034 fprintf (rtl_dump_file, "%d%% branches in range %d-%d%%\n",
1035 (total_hist_br_prob[i] + total_hist_br_prob[19-i]) * 100
1036 / total_num_branches, 5*i, 5*i+5);
1041 /* The label used by the edge profiling code. */
1043 static rtx profiler_label;
1045 /* Initialize the profiler_label. */
1048 init_edge_profiler ()
1050 /* Generate and save a copy of this so it can be shared. */
1052 ASM_GENERATE_INTERNAL_LABEL (buf, "LPBX", 2);
1053 profiler_label = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (buf));
1054 ggc_add_rtx_root (&profiler_label, 1);
1057 /* Output instructions as RTL to increment the edge execution count. */
1060 gen_edge_profiler (edgeno)
1063 enum machine_mode mode = mode_for_size (GCOV_TYPE_SIZE, MODE_INT, 0);
1069 tmp = force_reg (Pmode, profiler_label);
1070 tmp = plus_constant (tmp, GCOV_TYPE_SIZE / BITS_PER_UNIT * edgeno);
1071 mem_ref = validize_mem (gen_rtx_MEM (mode, tmp));
1073 tmp = expand_binop (mode, add_optab, mem_ref, const1_rtx,
1074 mem_ref, 0, OPTAB_WIDEN);
1077 emit_move_insn (copy_rtx (mem_ref), tmp);
1079 sequence = gen_sequence ();
1084 /* Output code for a constructor that will invoke __bb_init_func, if
1085 this has not already been done. */
1088 output_func_start_profiler ()
1090 tree fnname, fndecl;
1093 const char *cfnname;
1095 enum machine_mode mode = mode_for_size (GCOV_TYPE_SIZE, MODE_INT, 0);
1096 int save_flag_inline_functions = flag_inline_functions;
1097 int save_flag_test_coverage = flag_test_coverage;
1098 int save_profile_arc_flag = profile_arc_flag;
1099 int save_flag_branch_probabilities = flag_branch_probabilities;
1101 /* It's either already been output, or we don't need it because we're
1102 not doing profile-edges. */
1103 if (! need_func_profiler)
1106 need_func_profiler = 0;
1108 /* Synthesize a constructor function to invoke __bb_init_func with a
1109 pointer to this object file's profile block. */
1111 /* Try and make a unique name given the "file function name".
1113 And no, I don't like this either. */
1115 fnname = get_file_function_name ('I');
1116 cfnname = IDENTIFIER_POINTER (fnname);
1117 name = concat (cfnname, "GCOV", NULL);
1118 fnname = get_identifier (name);
1121 fndecl = build_decl (FUNCTION_DECL, fnname,
1122 build_function_type (void_type_node, NULL_TREE));
1123 DECL_EXTERNAL (fndecl) = 0;
1125 #if defined(ASM_OUTPUT_CONSTRUCTOR) && defined(ASM_OUTPUT_DESTRUCTOR)
1126 /* It can be a static function as long as collect2 does not have
1127 to scan the object file to find its ctor/dtor routine. */
1128 TREE_PUBLIC (fndecl) = 0;
1130 TREE_PUBLIC (fndecl) = 1;
1133 DECL_RESULT (fndecl) = build_decl (RESULT_DECL, NULL_TREE, void_type_node);
1135 fndecl = pushdecl (fndecl);
1136 rest_of_decl_compilation (fndecl, 0, 1, 0);
1137 announce_function (fndecl);
1138 current_function_decl = fndecl;
1139 DECL_INITIAL (fndecl) = error_mark_node;
1140 make_decl_rtl (fndecl, NULL);
1141 init_function_start (fndecl, input_filename, lineno);
1143 expand_function_start (fndecl, 0);
1145 /* Actually generate the code to call __bb_init_func. */
1146 ASM_GENERATE_INTERNAL_LABEL (buf, "LPBX", 0);
1147 table_address = force_reg (Pmode,
1148 gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (buf)));
1149 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__bb_init_func"), 0,
1150 mode, 1, table_address, Pmode);
1152 expand_function_end (input_filename, lineno, 0);
1155 /* Since fndecl isn't in the list of globals, it would never be emitted
1156 when it's considered to be 'safe' for inlining, so turn off
1157 flag_inline_functions. */
1158 flag_inline_functions = 0;
1160 /* Don't instrument the function that turns on instrumentation. Which
1161 is also handy since we'd get silly warnings about not consuming all
1162 of our da_file input. */
1163 flag_test_coverage = 0;
1164 profile_arc_flag = 0;
1165 flag_branch_probabilities = 0;
1167 rest_of_compilation (fndecl);
1169 /* Reset flag_inline_functions to its original value. */
1170 flag_inline_functions = save_flag_inline_functions;
1171 flag_test_coverage = save_flag_test_coverage;
1172 profile_arc_flag = save_profile_arc_flag;
1173 flag_branch_probabilities = save_flag_branch_probabilities;
1176 fflush (asm_out_file);
1177 current_function_decl = NULL_TREE;
1179 assemble_constructor (XEXP (DECL_RTL (fndecl), 0), DEFAULT_INIT_PRIORITY);