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 /* We can't handle cyclic regions constructed using abnormal edges.
532 To avoid these we replace every source of abnormal edge by a fake
533 edge from entry node and every destination by fake edge to exit.
534 This keeps graph acyclic and our calculation exact for all normal
535 edges except for exit and entrance ones.
537 We also add fake exit edges for each call and asm statement in the
538 basic, since it may not return. */
540 for (i = 0; i < n_basic_blocks ; i++)
543 int need_exit_edge = 0, need_entry_edge = 0;
544 int have_exit_edge = 0, have_entry_edge = 0;
545 basic_block bb = BASIC_BLOCK (i);
548 for (e = bb->succ; e; e = e->succ_next)
550 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
551 && e->dest != EXIT_BLOCK_PTR)
553 if (e->dest == EXIT_BLOCK_PTR)
556 for (e = bb->pred; e; e = e->pred_next)
558 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
559 && e->src != ENTRY_BLOCK_PTR)
561 if (e->src == ENTRY_BLOCK_PTR)
565 /* ??? Not strictly needed unless flag_test_coverage, but adding
566 them anyway keeps the .da file consistent. */
567 /* ??? Currently inexact for basic blocks with multiple calls.
568 We need to split blocks here. */
569 for (insn = bb->head;
570 insn != NEXT_INSN (bb->end);
571 insn = NEXT_INSN (insn))
574 if (GET_CODE (insn) == CALL_INSN && !CONST_CALL_P (insn))
576 else if (GET_CODE (insn) == INSN)
578 set = PATTERN (insn);
579 if (GET_CODE (set) == PARALLEL)
580 set = XVECEXP (set, 0, 0);
581 if ((GET_CODE (set) == ASM_OPERANDS && MEM_VOLATILE_P (set))
582 || GET_CODE (set) == ASM_INPUT)
587 if (need_exit_edge && !have_exit_edge)
590 fprintf (rtl_dump_file, "Adding fake exit edge to bb %i\n",
592 make_edge (NULL, bb, EXIT_BLOCK_PTR, EDGE_FAKE);
594 if (need_entry_edge && !have_entry_edge)
597 fprintf (rtl_dump_file, "Adding fake entry edge to bb %i\n",
599 make_edge (NULL, ENTRY_BLOCK_PTR, bb, EDGE_FAKE);
603 el = create_edge_list ();
604 num_edges = NUM_EDGES (el);
605 edge_infos = (struct edge_info *)
606 xcalloc (num_edges, sizeof (struct edge_info));
609 for (i = 0 ; i < num_edges ; i++)
611 edge e = INDEX_EDGE (el, i);
613 e->aux = &edge_infos[i];
615 /* Mark edges we've replaced by fake edges above as ignored. */
616 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
617 && e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR)
619 EDGE_INFO (e)->ignore = 1;
624 #ifdef ENABLE_CHECKING
628 /* Output line number information about each basic block for
630 if (flag_test_coverage)
633 for (i = 0 ; i < n_basic_blocks; i++)
635 basic_block bb = BASIC_BLOCK (i);
637 static int ignore_next_note = 0;
639 /* We are looking for line number notes. Search backward before
640 basic block to find correct ones. */
641 insn = prev_nonnote_insn (insn);
645 insn = NEXT_INSN (insn);
647 /* Output a zero to the .bb file to indicate that a new
648 block list is starting. */
649 __write_long (0, bb_file, 4);
651 while (insn != bb->end)
653 if (GET_CODE (insn) == NOTE)
655 /* Must ignore the line number notes that immediately
656 follow the end of an inline function to avoid counting
657 it twice. There is a note before the call, and one
659 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_REPEATED_LINE_NUMBER)
660 ignore_next_note = 1;
661 else if (NOTE_LINE_NUMBER (insn) > 0)
663 if (ignore_next_note)
664 ignore_next_note = 0;
667 /* If this is a new source file, then output the
668 file's name to the .bb file. */
669 if (! last_bb_file_name
670 || strcmp (NOTE_SOURCE_FILE (insn),
673 if (last_bb_file_name)
674 free (last_bb_file_name);
676 = xstrdup (NOTE_SOURCE_FILE (insn));
677 output_gcov_string (NOTE_SOURCE_FILE (insn),
680 /* Output the line number to the .bb file. Must be
681 done after the output_bb_profile_data() call, and
682 after the file name is written, to ensure that it
683 is correctly handled by gcov. */
684 __write_long (NOTE_LINE_NUMBER (insn), bb_file, 4);
688 insn = NEXT_INSN (insn);
691 __write_long (0, bb_file, 4);
694 /* Create spanning tree from basic block graph, mark each edge that is
695 on the spanning tree. We insert as many abnormal and critical edges
696 as possible to minimize number of edge splits necesary. */
698 find_spanning_tree (el);
700 /* Fake edges that are not on the tree will not be instrumented, so
701 mark them ignored. */
702 for (i = 0; i < num_edges; i++)
704 edge e = INDEX_EDGE (el, i);
705 struct edge_info *inf = EDGE_INFO (e);
706 if ((e->flags & EDGE_FAKE) && !inf->ignore && !inf->on_tree)
713 total_num_blocks += n_basic_blocks + 2;
715 fprintf (rtl_dump_file, "%d basic blocks\n", n_basic_blocks);
717 total_num_edges += num_edges;
719 fprintf (rtl_dump_file, "%d edges\n", num_edges);
721 total_num_edges_ignored += ignored_edges;
723 fprintf (rtl_dump_file, "%d ignored edges\n", ignored_edges);
725 /* Create a .bbg file from which gcov can reconstruct the basic block
726 graph. First output the number of basic blocks, and then for every
727 edge output the source and target basic block numbers.
728 NOTE: The format of this file must be compatible with gcov. */
730 if (flag_test_coverage)
734 /* The plus 2 stands for entry and exit block. */
735 __write_long (n_basic_blocks + 2, bbg_file, 4);
736 __write_long (num_edges - ignored_edges + 1, bbg_file, 4);
738 for (i = 0; i < n_basic_blocks + 1; i++)
740 basic_block bb = GCOV_INDEX_TO_BB (i);
744 for (e = bb->succ; e; e = e->succ_next)
745 if (!EDGE_INFO (e)->ignore)
747 __write_long (count, bbg_file, 4);
749 for (e = bb->succ; e; e = e->succ_next)
751 struct edge_info *i = EDGE_INFO (e);
757 if (e->flags & EDGE_FAKE)
759 if (e->flags & EDGE_FALLTHRU)
762 __write_long (BB_TO_GCOV_INDEX (e->dest), bbg_file, 4);
763 __write_long (flag_bits, bbg_file, 4);
767 /* Emit fake loopback edge for EXIT block to maitain compatibility with
769 __write_long (1, bbg_file, 4);
770 __write_long (0, bbg_file, 4);
771 __write_long (0x1, bbg_file, 4);
773 /* Emit a -1 to separate the list of all edges from the list of
774 loop back edges that follows. */
775 __write_long (-1, bbg_file, 4);
778 if (flag_branch_probabilities)
779 compute_branch_probabilities ();
781 /* For each edge not on the spanning tree, add counting code as rtl. */
783 if (profile_arc_flag)
785 instrument_edges (el);
786 allocate_reg_info (max_reg_num (), FALSE, FALSE);
789 remove_fake_edges ();
794 /* Union find algorithm implementation for the basic blocks using
801 basic_block group = bb, bb1;
803 while ((basic_block) group->aux != group)
804 group = (basic_block) group->aux;
807 while ((basic_block) bb->aux != group)
809 bb1 = (basic_block) bb->aux;
810 bb->aux = (void *) group;
817 union_groups (bb1, bb2)
818 basic_block bb1, bb2;
820 basic_block bb1g = find_group (bb1);
821 basic_block bb2g = find_group (bb2);
823 /* ??? I don't have a place for the rank field. OK. Lets go w/o it,
824 this code is unlikely going to be performance problem anyway. */
831 /* This function searches all of the edges in the program flow graph, and puts
832 as many bad edges as possible onto the spanning tree. Bad edges include
833 abnormals edges, which can't be instrumented at the moment. Since it is
834 possible for fake edges to form an cycle, we will have to develop some
835 better way in the future. Also put critical edges to the tree, since they
836 are more expensive to instrument. */
839 find_spanning_tree (el)
840 struct edge_list *el;
843 int num_edges = NUM_EDGES (el);
845 /* We use aux field for standard union-find algorithm. */
846 EXIT_BLOCK_PTR->aux = EXIT_BLOCK_PTR;
847 ENTRY_BLOCK_PTR->aux = ENTRY_BLOCK_PTR;
848 for (i = 0; i < n_basic_blocks; i++)
849 BASIC_BLOCK (i)->aux = BASIC_BLOCK (i);
851 /* Add fake edge exit to entry we can't instrument. */
852 union_groups (EXIT_BLOCK_PTR, ENTRY_BLOCK_PTR);
854 /* First add all abnormal edges to the tree unless they form an cycle. */
855 for (i = 0; i < num_edges; i++)
857 edge e = INDEX_EDGE (el, i);
858 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_FAKE))
859 && !EDGE_INFO (e)->ignore
860 && (find_group (e->src) != find_group (e->dest)))
862 EDGE_INFO (e)->on_tree = 1;
863 union_groups (e->src, e->dest);
867 /* Now insert all critical edges to the tree unless they form an cycle. */
868 for (i = 0; i < num_edges; i++)
870 edge e = INDEX_EDGE (el, i);
871 if ((e->flags & EDGE_CRITICAL)
872 && !EDGE_INFO (e)->ignore
873 && (find_group (e->src) != find_group (e->dest)))
875 EDGE_INFO (e)->on_tree = 1;
876 union_groups (e->src, e->dest);
880 /* And now the rest. */
881 for (i = 0; i < num_edges; i++)
883 edge e = INDEX_EDGE (el, i);
884 if (find_group (e->src) != find_group (e->dest)
885 && !EDGE_INFO (e)->ignore)
887 EDGE_INFO (e)->on_tree = 1;
888 union_groups (e->src, e->dest);
893 /* Perform file-level initialization for branch-prob processing. */
896 init_branch_prob (filename)
897 const char *filename;
902 if (flag_test_coverage)
904 int len = strlen (filename);
905 char *data_file, *bbg_file_name;
907 /* Open an output file for the basic block/line number map. */
908 data_file = (char *) alloca (len + 4);
909 strcpy (data_file, filename);
910 strip_off_ending (data_file, len);
911 strcat (data_file, ".bb");
912 if ((bb_file = fopen (data_file, "wb")) == 0)
913 fatal_io_error ("can't open %s", data_file);
915 /* Open an output file for the program flow graph. */
916 bbg_file_name = (char *) alloca (len + 5);
917 strcpy (bbg_file_name, filename);
918 strip_off_ending (bbg_file_name, len);
919 strcat (bbg_file_name, ".bbg");
920 if ((bbg_file = fopen (bbg_file_name, "wb")) == 0)
921 fatal_io_error ("can't open %s", bbg_file_name);
923 /* Initialize to zero, to ensure that the first file name will be
924 written to the .bb file. */
925 last_bb_file_name = 0;
928 if (flag_branch_probabilities)
932 len = strlen (filename);
933 da_file_name = (char *) alloca (len + 4);
934 strcpy (da_file_name, filename);
935 strip_off_ending (da_file_name, len);
936 strcat (da_file_name, ".da");
937 if ((da_file = fopen (da_file_name, "rb")) == 0)
938 warning ("file %s not found, execution counts assumed to be zero.",
941 /* The first word in the .da file gives the number of instrumented
942 edges, which is not needed for our purposes. */
945 __read_long (&len, da_file, 8);
948 if (profile_arc_flag)
949 init_edge_profiler ();
951 total_num_blocks = 0;
953 total_num_edges_ignored = 0;
954 total_num_edges_instrumented = 0;
955 total_num_blocks_created = 0;
956 total_num_passes = 0;
957 total_num_times_called = 0;
958 total_num_branches = 0;
959 total_num_never_executed = 0;
960 for (i = 0; i < 20; i++)
961 total_hist_br_prob[i] = 0;
964 /* Performs file-level cleanup after branch-prob processing
970 if (flag_test_coverage)
976 if (flag_branch_probabilities)
981 /* This seems slightly dangerous, as it presumes the EOF
982 flag will not be set until an attempt is made to read
983 past the end of the file. */
985 error (".da file contents exhausted too early");
986 /* Should be at end of file now. */
987 if (__read_long (&temp, da_file, 8) == 0)
988 error (".da file contents not exhausted");
995 fprintf (rtl_dump_file, "\n");
996 fprintf (rtl_dump_file, "Total number of blocks: %d\n",
998 fprintf (rtl_dump_file, "Total number of edges: %d\n", total_num_edges);
999 fprintf (rtl_dump_file, "Total number of ignored edges: %d\n",
1000 total_num_edges_ignored);
1001 fprintf (rtl_dump_file, "Total number of instrumented edges: %d\n",
1002 total_num_edges_instrumented);
1003 fprintf (rtl_dump_file, "Total number of blocks created: %d\n",
1004 total_num_blocks_created);
1005 fprintf (rtl_dump_file, "Total number of graph solution passes: %d\n",
1007 if (total_num_times_called != 0)
1008 fprintf (rtl_dump_file, "Average number of graph solution passes: %d\n",
1009 (total_num_passes + (total_num_times_called >> 1))
1010 / total_num_times_called);
1011 fprintf (rtl_dump_file, "Total number of branches: %d\n",
1012 total_num_branches);
1013 fprintf (rtl_dump_file, "Total number of branches never executed: %d\n",
1014 total_num_never_executed);
1015 if (total_num_branches)
1019 for (i = 0; i < 10; i++)
1020 fprintf (rtl_dump_file, "%d%% branches in range %d-%d%%\n",
1021 (total_hist_br_prob[i] + total_hist_br_prob[19-i]) * 100
1022 / total_num_branches, 5*i, 5*i+5);
1027 /* The label used by the edge profiling code. */
1029 static rtx profiler_label;
1031 /* Initialize the profiler_label. */
1034 init_edge_profiler ()
1036 /* Generate and save a copy of this so it can be shared. */
1038 ASM_GENERATE_INTERNAL_LABEL (buf, "LPBX", 2);
1039 profiler_label = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (buf));
1040 ggc_add_rtx_root (&profiler_label, 1);
1043 /* Output instructions as RTL to increment the edge execution count. */
1046 gen_edge_profiler (edgeno)
1049 enum machine_mode mode = mode_for_size (GCOV_TYPE_SIZE, MODE_INT, 0);
1055 tmp = force_reg (Pmode, profiler_label);
1056 tmp = plus_constant (tmp, GCOV_TYPE_SIZE / BITS_PER_UNIT * edgeno);
1057 mem_ref = validize_mem (gen_rtx_MEM (mode, tmp));
1059 tmp = expand_binop (mode, add_optab, mem_ref, const1_rtx,
1060 mem_ref, 0, OPTAB_WIDEN);
1063 emit_move_insn (copy_rtx (mem_ref), tmp);
1065 sequence = gen_sequence ();
1070 /* Output code for a constructor that will invoke __bb_init_func, if
1071 this has not already been done. */
1074 output_func_start_profiler ()
1076 tree fnname, fndecl;
1079 const char *cfnname;
1081 enum machine_mode mode = mode_for_size (GCOV_TYPE_SIZE, MODE_INT, 0);
1082 int save_flag_inline_functions = flag_inline_functions;
1083 int save_flag_test_coverage = flag_test_coverage;
1084 int save_profile_arc_flag = profile_arc_flag;
1085 int save_flag_branch_probabilities = flag_branch_probabilities;
1087 /* It's either already been output, or we don't need it because we're
1088 not doing profile-edges. */
1089 if (! need_func_profiler)
1092 need_func_profiler = 0;
1094 /* Synthesize a constructor function to invoke __bb_init_func with a
1095 pointer to this object file's profile block. */
1097 /* Try and make a unique name given the "file function name".
1099 And no, I don't like this either. */
1101 fnname = get_file_function_name ('I');
1102 cfnname = IDENTIFIER_POINTER (fnname);
1103 name = concat (cfnname, "GCOV", NULL);
1104 fnname = get_identifier (name);
1107 fndecl = build_decl (FUNCTION_DECL, fnname,
1108 build_function_type (void_type_node, NULL_TREE));
1109 DECL_EXTERNAL (fndecl) = 0;
1111 #if defined(ASM_OUTPUT_CONSTRUCTOR) && defined(ASM_OUTPUT_DESTRUCTOR)
1112 /* It can be a static function as long as collect2 does not have
1113 to scan the object file to find its ctor/dtor routine. */
1114 TREE_PUBLIC (fndecl) = 0;
1116 TREE_PUBLIC (fndecl) = 1;
1119 DECL_RESULT (fndecl) = build_decl (RESULT_DECL, NULL_TREE, void_type_node);
1121 fndecl = pushdecl (fndecl);
1122 rest_of_decl_compilation (fndecl, 0, 1, 0);
1123 announce_function (fndecl);
1124 current_function_decl = fndecl;
1125 DECL_INITIAL (fndecl) = error_mark_node;
1126 make_decl_rtl (fndecl, NULL);
1127 init_function_start (fndecl, input_filename, lineno);
1129 expand_function_start (fndecl, 0);
1131 /* Actually generate the code to call __bb_init_func. */
1132 ASM_GENERATE_INTERNAL_LABEL (buf, "LPBX", 0);
1133 table_address = force_reg (Pmode,
1134 gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (buf)));
1135 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__bb_init_func"), 0,
1136 mode, 1, table_address, Pmode);
1138 expand_function_end (input_filename, lineno, 0);
1141 /* Since fndecl isn't in the list of globals, it would never be emitted
1142 when it's considered to be 'safe' for inlining, so turn off
1143 flag_inline_functions. */
1144 flag_inline_functions = 0;
1146 /* Don't instrument the function that turns on instrumentation. Which
1147 is also handy since we'd get silly warnings about not consuming all
1148 of our da_file input. */
1149 flag_test_coverage = 0;
1150 profile_arc_flag = 0;
1151 flag_branch_probabilities = 0;
1153 rest_of_compilation (fndecl);
1155 /* Reset flag_inline_functions to its original value. */
1156 flag_inline_functions = save_flag_inline_functions;
1157 flag_test_coverage = save_flag_test_coverage;
1158 profile_arc_flag = save_profile_arc_flag;
1159 flag_branch_probabilities = save_flag_branch_probabilities;
1162 fflush (asm_out_file);
1163 current_function_decl = NULL_TREE;
1165 assemble_constructor (IDENTIFIER_POINTER (DECL_NAME (fndecl)));