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"
49 #include "hard-reg-set.h"
50 #include "basic-block.h"
54 /* Additional information about the edges we need. */
57 unsigned int count_valid : 1;
58 unsigned int on_tree : 1;
59 unsigned int ignore : 1;
63 unsigned int count_valid : 1;
68 #define EDGE_INFO(e) ((struct edge_info *) (e)->aux)
69 #define BB_INFO(b) ((struct bb_info *) (b)->aux)
71 /* Keep all basic block indexes nonnegative in the gcov output. Index 0
72 is used for entry block, last block exit block. */
73 #define GCOV_INDEX_TO_BB(i) ((i) == 0 ? ENTRY_BLOCK_PTR \
74 : (((i) == n_basic_blocks + 1) \
75 ? EXIT_BLOCK_PTR : BASIC_BLOCK ((i)-1)))
76 #define BB_TO_GCOV_INDEX(bb) ((bb) == ENTRY_BLOCK_PTR ? 0 \
77 : ((bb) == EXIT_BLOCK_PTR \
78 ? n_basic_blocks + 1 : (bb)->index + 1))
80 /* Name and file pointer of the output file for the basic block graph. */
82 static FILE *bbg_file;
84 /* Name and file pointer of the input file for the arc count data. */
88 /* Pointer of the output file for the basic block/line number map. */
91 /* Last source file name written to bb_file. */
93 static char *last_bb_file_name;
95 /* Used by final, for allocating the proper amount of storage for the
96 instrumented arc execution counts. */
98 int count_instrumented_edges;
100 /* Collect statistics on the performance of this pass for the entire source
103 static int total_num_blocks;
104 static int total_num_edges;
105 static int total_num_edges_ignored;
106 static int total_num_edges_instrumented;
107 static int total_num_blocks_created;
108 static int total_num_passes;
109 static int total_num_times_called;
110 static int total_hist_br_prob[20];
111 static int total_num_never_executed;
112 static int total_num_branches;
114 /* Forward declarations. */
115 static void find_spanning_tree PARAMS ((struct edge_list *));
116 static void init_edge_profiler PARAMS ((void));
117 static rtx gen_edge_profiler PARAMS ((int));
118 static void instrument_edges PARAMS ((struct edge_list *));
119 static void output_gcov_string PARAMS ((const char *, long));
120 static void compute_branch_probabilities PARAMS ((void));
121 static basic_block find_group PARAMS ((basic_block));
122 static void union_groups PARAMS ((basic_block, basic_block));
124 /* If non-zero, we need to output a constructor to set up the
125 per-object-file data. */
126 static int need_func_profiler = 0;
128 /* Add edge instrumentation code to the entire insn chain.
130 F is the first insn of the chain.
131 NUM_BLOCKS is the number of basic blocks found in F. */
134 instrument_edges (el)
135 struct edge_list *el;
138 int num_instr_edges = 0;
139 int num_edges = NUM_EDGES (el);
140 remove_fake_edges ();
142 for (i = 0; i < n_basic_blocks + 2; i++)
144 basic_block bb = GCOV_INDEX_TO_BB (i);
148 struct edge_info *inf = EDGE_INFO (e);
149 if (!inf->ignore && !inf->on_tree)
151 if (e->flags & EDGE_ABNORMAL)
154 fprintf (rtl_dump_file, "Edge %d to %d instrumented%s\n",
155 e->src->index, e->dest->index,
156 e->flags & EDGE_CRITICAL ? " (and split)" : "");
157 need_func_profiler = 1;
158 insert_insn_on_edge (
159 gen_edge_profiler (total_num_edges_instrumented
160 + num_instr_edges++), e);
166 total_num_edges_instrumented += num_instr_edges;
167 count_instrumented_edges = total_num_edges_instrumented;
169 total_num_blocks_created += num_edges;
171 fprintf (rtl_dump_file, "%d edges instrumented\n", num_instr_edges);
173 commit_edge_insertions ();
176 /* Output STRING to bb_file, surrounded by DELIMITER. */
179 output_gcov_string (string, delimiter)
185 /* Write a delimiter to indicate that a file name follows. */
186 __write_long (delimiter, bb_file, 4);
188 /* Write the string. */
189 temp = strlen (string) + 1;
190 fwrite (string, temp, 1, bb_file);
192 /* Append a few zeros, to align the output to a 4 byte boundary. */
198 c[0] = c[1] = c[2] = c[3] = 0;
199 fwrite (c, sizeof (char), 4 - temp, bb_file);
202 /* Store another delimiter in the .bb file, just to make it easy to find
203 the end of the file name. */
204 __write_long (delimiter, bb_file, 4);
208 /* Compute the branch probabilities for the various branches.
209 Annotate them accordingly. */
212 compute_branch_probabilities ()
218 int hist_br_prob[20];
219 int num_never_executed;
221 struct bb_info *bb_infos;
223 /* Attach extra info block to each bb. */
225 bb_infos = (struct bb_info *)
226 xcalloc (n_basic_blocks + 2, sizeof (struct bb_info));
227 for (i = 0; i < n_basic_blocks + 2; i++)
229 basic_block bb = GCOV_INDEX_TO_BB (i);
232 bb->aux = &bb_infos[i];
233 for (e = bb->succ; e; e = e->succ_next)
234 if (!EDGE_INFO (e)->ignore)
235 BB_INFO (bb)->succ_count++;
236 for (e = bb->pred; e; e = e->pred_next)
237 if (!EDGE_INFO (e)->ignore)
238 BB_INFO (bb)->pred_count++;
241 /* Avoid predicting entry on exit nodes. */
242 BB_INFO (EXIT_BLOCK_PTR)->succ_count = 2;
243 BB_INFO (ENTRY_BLOCK_PTR)->pred_count = 2;
245 /* For each edge not on the spanning tree, set its execution count from
248 /* The first count in the .da file is the number of times that the function
249 was entered. This is the exec_count for block zero. */
251 for (i = 0; i < n_basic_blocks + 2; i++)
253 basic_block bb = GCOV_INDEX_TO_BB (i);
255 for (e = bb->succ; e; e = e->succ_next)
256 if (!EDGE_INFO (e)->ignore && !EDGE_INFO (e)->on_tree)
262 __read_gcov_type (&value, da_file, 8);
267 EDGE_INFO (e)->count_valid = 1;
268 BB_INFO (bb)->succ_count--;
269 BB_INFO (e->dest)->pred_count--;
272 fprintf (rtl_dump_file, "\nRead edge from %i to %i, count:",
273 bb->index, e->dest->index);
274 fprintf (rtl_dump_file, HOST_WIDEST_INT_PRINT_DEC,
275 (HOST_WIDEST_INT) e->count);
281 fprintf (rtl_dump_file, "\n%d edge counts read\n", num_edges);
283 /* For every block in the file,
284 - if every exit/entrance edge has a known count, then set the block count
285 - if the block count is known, and every exit/entrance edge but one has
286 a known execution count, then set the count of the remaining edge
288 As edge counts are set, decrement the succ/pred count, but don't delete
289 the edge, that way we can easily tell when all edges are known, or only
290 one edge is unknown. */
292 /* The order that the basic blocks are iterated through is important.
293 Since the code that finds spanning trees starts with block 0, low numbered
294 edges are put on the spanning tree in preference to high numbered edges.
295 Hence, most instrumented edges are at the end. Graph solving works much
296 faster if we propagate numbers from the end to the start.
298 This takes an average of slightly more than 3 passes. */
306 for (i = n_basic_blocks + 1; i >= 0; i--)
308 basic_block bb = GCOV_INDEX_TO_BB (i);
309 struct bb_info *bi = BB_INFO (bb);
310 if (! bi->count_valid)
312 if (bi->succ_count == 0)
317 for (e = bb->succ; e; e = e->succ_next)
323 else if (bi->pred_count == 0)
328 for (e = bb->pred; e; e = e->pred_next)
337 if (bi->succ_count == 1)
342 /* One of the counts will be invalid, but it is zero,
343 so adding it in also doesn't hurt. */
344 for (e = bb->succ; e; e = e->succ_next)
347 /* Seedgeh for the invalid edge, and set its count. */
348 for (e = bb->succ; e; e = e->succ_next)
349 if (! EDGE_INFO (e)->count_valid && ! EDGE_INFO (e)->ignore)
352 /* Calculate count for remaining edge by conservation. */
353 total = bb->count - total;
357 EDGE_INFO (e)->count_valid = 1;
361 BB_INFO (e->dest)->pred_count--;
364 if (bi->pred_count == 1)
369 /* One of the counts will be invalid, but it is zero,
370 so adding it in also doesn't hurt. */
371 for (e = bb->pred; e; e = e->pred_next)
374 /* Seedgeh for the invalid edge, and set its count. */
375 for (e = bb->pred; e; e = e->pred_next)
376 if (! EDGE_INFO (e)->count_valid && ! EDGE_INFO (e)->ignore)
379 /* Calculate count for remaining edge by conservation. */
380 total = bb->count - total + e->count;
384 EDGE_INFO (e)->count_valid = 1;
388 BB_INFO (e->src)->succ_count--;
395 dump_flow_info (rtl_dump_file);
397 total_num_passes += passes;
399 fprintf (rtl_dump_file, "Graph solving took %d passes.\n\n", passes);
401 /* If the graph has been correctly solved, every block will have a
402 succ and pred count of zero. */
403 for (i = 0; i < n_basic_blocks; i++)
405 basic_block bb = BASIC_BLOCK (i);
406 if (BB_INFO (bb)->succ_count || BB_INFO (bb)->pred_count)
410 /* For every edge, calculate its branch probability and add a reg_note
411 to the branch insn to indicate this. */
413 for (i = 0; i < 20; i++)
415 num_never_executed = 0;
418 for (i = 0; i < n_basic_blocks; i++)
420 basic_block bb = BASIC_BLOCK (i);
427 for (e = bb->succ; e; e = e->succ_next)
429 e->probability = (e->count * REG_BR_PROB_BASE + total / 2) / total;
430 if (e->probability < 0 || e->probability > REG_BR_PROB_BASE)
432 error ("Corrupted profile info: prob for %d-%d thought to be %d\n",
433 e->src->index, e->dest->index, e->probability);
434 e->probability = REG_BR_PROB_BASE / 2;
437 if (any_condjump_p (bb->end)
438 && bb->succ->succ_next)
447 num_never_executed++;
452 /* Find the branch edge. It is possible that we do have fake
454 for (e = bb->succ; e->flags & (EDGE_FAKE | EDGE_FALLTHRU);
456 continue; /* Loop body has been intentionally left blank. */
458 prob = e->probability;
459 index = prob * 20 / REG_BR_PROB_BASE;
463 hist_br_prob[index]++;
465 note = find_reg_note (bb->end, REG_BR_PROB, 0);
466 /* There may be already note put by some other pass, such
467 as builtin_expect expander. */
469 XEXP (note, 0) = GEN_INT (prob);
472 = gen_rtx_EXPR_LIST (REG_BR_PROB, GEN_INT (prob),
473 REG_NOTES (bb->end));
482 fprintf (rtl_dump_file, "%d branches\n", num_branches);
483 fprintf (rtl_dump_file, "%d branches never executed\n",
486 for (i = 0; i < 10; i++)
487 fprintf (rtl_dump_file, "%d%% branches in range %d-%d%%\n",
488 (hist_br_prob[i] + hist_br_prob[19-i]) * 100 / num_branches,
491 total_num_branches += num_branches;
492 total_num_never_executed += num_never_executed;
493 for (i = 0; i < 20; i++)
494 total_hist_br_prob[i] += hist_br_prob[i];
496 fputc ('\n', rtl_dump_file);
497 fputc ('\n', rtl_dump_file);
503 /* Instrument and/or analyze program behavior based on program flow graph.
504 In either case, this function builds a flow graph for the function being
505 compiled. The flow graph is stored in BB_GRAPH.
507 When FLAG_PROFILE_ARCS is nonzero, this function instruments the edges in
508 the flow graph that are needed to reconstruct the dynamic behavior of the
511 When FLAG_BRANCH_PROBABILITIES is nonzero, this function reads auxiliary
512 information from a data file containing edge count information from previous
513 executions of the function being compiled. In this case, the flow graph is
514 annotated with actual execution counts, which are later propagated into the
515 rtl for optimization purposes.
517 Main entry point of this file. */
523 int num_edges, ignored_edges;
524 struct edge_info *edge_infos;
525 struct edge_list *el;
527 /* Start of a function. */
528 if (flag_test_coverage)
529 output_gcov_string (current_function_name, (long) -2);
531 total_num_times_called++;
533 flow_call_edges_add (NULL);
535 /* We can't handle cyclic regions constructed using abnormal edges.
536 To avoid these we replace every source of abnormal edge by a fake
537 edge from entry node and every destination by fake edge to exit.
538 This keeps graph acyclic and our calculation exact for all normal
539 edges except for exit and entrance ones.
541 We also add fake exit edges for each call and asm statement in the
542 basic, since it may not return. */
544 for (i = 0; i < n_basic_blocks ; i++)
546 int need_exit_edge = 0, need_entry_edge = 0;
547 int have_exit_edge = 0, have_entry_edge = 0;
548 basic_block bb = BASIC_BLOCK (i);
552 /* Add fake edges from entry block to the call insns that may return
553 twice. The CFG is not quite correct then, as call insn plays more
554 role of CODE_LABEL, but for our purposes, everything should be OK,
555 as we never insert code to the beggining of basic block. */
556 for (insn = bb->head; insn != NEXT_INSN (bb->end);
557 insn = NEXT_INSN (insn))
559 if (GET_CODE (insn) == CALL_INSN
560 && find_reg_note (insn, REG_SETJMP, NULL))
562 if (GET_CODE (bb->head) == CODE_LABEL
563 || insn != NEXT_INSN (bb->head))
565 e = split_block (bb, PREV_INSN (insn));
566 make_edge (NULL, ENTRY_BLOCK_PTR, e->dest, EDGE_FAKE);
571 /* We should not get abort here, as call to setjmp should not
572 be the very first instruction of function. */
575 make_edge (NULL, ENTRY_BLOCK_PTR, bb, EDGE_FAKE);
580 for (e = bb->succ; e; e = e->succ_next)
582 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
583 && e->dest != EXIT_BLOCK_PTR)
585 if (e->dest == EXIT_BLOCK_PTR)
588 for (e = bb->pred; e; e = e->pred_next)
590 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
591 && e->src != ENTRY_BLOCK_PTR)
593 if (e->src == ENTRY_BLOCK_PTR)
597 if (need_exit_edge && !have_exit_edge)
600 fprintf (rtl_dump_file, "Adding fake exit edge to bb %i\n",
602 make_edge (NULL, bb, EXIT_BLOCK_PTR, EDGE_FAKE);
604 if (need_entry_edge && !have_entry_edge)
607 fprintf (rtl_dump_file, "Adding fake entry edge to bb %i\n",
609 make_edge (NULL, ENTRY_BLOCK_PTR, bb, EDGE_FAKE);
613 el = create_edge_list ();
614 num_edges = NUM_EDGES (el);
615 edge_infos = (struct edge_info *)
616 xcalloc (num_edges, sizeof (struct edge_info));
619 for (i = 0 ; i < num_edges ; i++)
621 edge e = INDEX_EDGE (el, i);
623 e->aux = &edge_infos[i];
625 /* Mark edges we've replaced by fake edges above as ignored. */
626 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
627 && e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR)
629 EDGE_INFO (e)->ignore = 1;
634 #ifdef ENABLE_CHECKING
638 /* Output line number information about each basic block for
640 if (flag_test_coverage)
643 for (i = 0 ; i < n_basic_blocks; i++)
645 basic_block bb = BASIC_BLOCK (i);
647 static int ignore_next_note = 0;
649 /* We are looking for line number notes. Search backward before
650 basic block to find correct ones. */
651 insn = prev_nonnote_insn (insn);
655 insn = NEXT_INSN (insn);
657 /* Output a zero to the .bb file to indicate that a new
658 block list is starting. */
659 __write_long (0, bb_file, 4);
661 while (insn != bb->end)
663 if (GET_CODE (insn) == NOTE)
665 /* Must ignore the line number notes that immediately
666 follow the end of an inline function to avoid counting
667 it twice. There is a note before the call, and one
669 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_REPEATED_LINE_NUMBER)
670 ignore_next_note = 1;
671 else if (NOTE_LINE_NUMBER (insn) > 0)
673 if (ignore_next_note)
674 ignore_next_note = 0;
677 /* If this is a new source file, then output the
678 file's name to the .bb file. */
679 if (! last_bb_file_name
680 || strcmp (NOTE_SOURCE_FILE (insn),
683 if (last_bb_file_name)
684 free (last_bb_file_name);
686 = xstrdup (NOTE_SOURCE_FILE (insn));
687 output_gcov_string (NOTE_SOURCE_FILE (insn),
690 /* Output the line number to the .bb file. Must be
691 done after the output_bb_profile_data() call, and
692 after the file name is written, to ensure that it
693 is correctly handled by gcov. */
694 __write_long (NOTE_LINE_NUMBER (insn), bb_file, 4);
698 insn = NEXT_INSN (insn);
701 __write_long (0, bb_file, 4);
704 /* Create spanning tree from basic block graph, mark each edge that is
705 on the spanning tree. We insert as many abnormal and critical edges
706 as possible to minimize number of edge splits necesary. */
708 find_spanning_tree (el);
710 /* Fake edges that are not on the tree will not be instrumented, so
711 mark them ignored. */
712 for (i = 0; i < num_edges; i++)
714 edge e = INDEX_EDGE (el, i);
715 struct edge_info *inf = EDGE_INFO (e);
716 if ((e->flags & EDGE_FAKE) && !inf->ignore && !inf->on_tree)
723 total_num_blocks += n_basic_blocks + 2;
725 fprintf (rtl_dump_file, "%d basic blocks\n", n_basic_blocks);
727 total_num_edges += num_edges;
729 fprintf (rtl_dump_file, "%d edges\n", num_edges);
731 total_num_edges_ignored += ignored_edges;
733 fprintf (rtl_dump_file, "%d ignored edges\n", ignored_edges);
735 /* Create a .bbg file from which gcov can reconstruct the basic block
736 graph. First output the number of basic blocks, and then for every
737 edge output the source and target basic block numbers.
738 NOTE: The format of this file must be compatible with gcov. */
740 if (flag_test_coverage)
744 /* The plus 2 stands for entry and exit block. */
745 __write_long (n_basic_blocks + 2, bbg_file, 4);
746 __write_long (num_edges - ignored_edges + 1, bbg_file, 4);
748 for (i = 0; i < n_basic_blocks + 1; i++)
750 basic_block bb = GCOV_INDEX_TO_BB (i);
754 for (e = bb->succ; e; e = e->succ_next)
755 if (!EDGE_INFO (e)->ignore)
757 __write_long (count, bbg_file, 4);
759 for (e = bb->succ; e; e = e->succ_next)
761 struct edge_info *i = EDGE_INFO (e);
767 if (e->flags & EDGE_FAKE)
769 if (e->flags & EDGE_FALLTHRU)
772 __write_long (BB_TO_GCOV_INDEX (e->dest), bbg_file, 4);
773 __write_long (flag_bits, bbg_file, 4);
777 /* Emit fake loopback edge for EXIT block to maitain compatibility with
779 __write_long (1, bbg_file, 4);
780 __write_long (0, bbg_file, 4);
781 __write_long (0x1, bbg_file, 4);
783 /* Emit a -1 to separate the list of all edges from the list of
784 loop back edges that follows. */
785 __write_long (-1, bbg_file, 4);
788 if (flag_branch_probabilities)
789 compute_branch_probabilities ();
791 /* For each edge not on the spanning tree, add counting code as rtl. */
793 if (profile_arc_flag)
795 instrument_edges (el);
796 allocate_reg_info (max_reg_num (), FALSE, FALSE);
799 remove_fake_edges ();
800 /* Re-merge split basic blocks and the mess introduced by
801 insert_insn_on_edge. */
802 cleanup_cfg (profile_arc_flag ? CLEANUP_EXPENSIVE : 0);
804 dump_flow_info (rtl_dump_file);
810 /* Union find algorithm implementation for the basic blocks using
817 basic_block group = bb, bb1;
819 while ((basic_block) group->aux != group)
820 group = (basic_block) group->aux;
823 while ((basic_block) bb->aux != group)
825 bb1 = (basic_block) bb->aux;
826 bb->aux = (void *) group;
833 union_groups (bb1, bb2)
834 basic_block bb1, bb2;
836 basic_block bb1g = find_group (bb1);
837 basic_block bb2g = find_group (bb2);
839 /* ??? I don't have a place for the rank field. OK. Lets go w/o it,
840 this code is unlikely going to be performance problem anyway. */
847 /* This function searches all of the edges in the program flow graph, and puts
848 as many bad edges as possible onto the spanning tree. Bad edges include
849 abnormals edges, which can't be instrumented at the moment. Since it is
850 possible for fake edges to form an cycle, we will have to develop some
851 better way in the future. Also put critical edges to the tree, since they
852 are more expensive to instrument. */
855 find_spanning_tree (el)
856 struct edge_list *el;
859 int num_edges = NUM_EDGES (el);
861 /* We use aux field for standard union-find algorithm. */
862 EXIT_BLOCK_PTR->aux = EXIT_BLOCK_PTR;
863 ENTRY_BLOCK_PTR->aux = ENTRY_BLOCK_PTR;
864 for (i = 0; i < n_basic_blocks; i++)
865 BASIC_BLOCK (i)->aux = BASIC_BLOCK (i);
867 /* Add fake edge exit to entry we can't instrument. */
868 union_groups (EXIT_BLOCK_PTR, ENTRY_BLOCK_PTR);
870 /* First add all abnormal edges to the tree unless they form an cycle. */
871 for (i = 0; i < num_edges; i++)
873 edge e = INDEX_EDGE (el, i);
874 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_FAKE))
875 && !EDGE_INFO (e)->ignore
876 && (find_group (e->src) != find_group (e->dest)))
878 EDGE_INFO (e)->on_tree = 1;
879 union_groups (e->src, e->dest);
883 /* Now insert all critical edges to the tree unless they form an cycle. */
884 for (i = 0; i < num_edges; i++)
886 edge e = INDEX_EDGE (el, i);
887 if ((e->flags & EDGE_CRITICAL)
888 && !EDGE_INFO (e)->ignore
889 && (find_group (e->src) != find_group (e->dest)))
891 EDGE_INFO (e)->on_tree = 1;
892 union_groups (e->src, e->dest);
896 /* And now the rest. */
897 for (i = 0; i < num_edges; i++)
899 edge e = INDEX_EDGE (el, i);
900 if (find_group (e->src) != find_group (e->dest)
901 && !EDGE_INFO (e)->ignore)
903 EDGE_INFO (e)->on_tree = 1;
904 union_groups (e->src, e->dest);
909 /* Perform file-level initialization for branch-prob processing. */
912 init_branch_prob (filename)
913 const char *filename;
918 if (flag_test_coverage)
920 int len = strlen (filename);
921 char *data_file, *bbg_file_name;
923 /* Open an output file for the basic block/line number map. */
924 data_file = (char *) alloca (len + 4);
925 strcpy (data_file, filename);
926 strip_off_ending (data_file, len);
927 strcat (data_file, ".bb");
928 if ((bb_file = fopen (data_file, "wb")) == 0)
929 fatal_io_error ("can't open %s", data_file);
931 /* Open an output file for the program flow graph. */
932 bbg_file_name = (char *) alloca (len + 5);
933 strcpy (bbg_file_name, filename);
934 strip_off_ending (bbg_file_name, len);
935 strcat (bbg_file_name, ".bbg");
936 if ((bbg_file = fopen (bbg_file_name, "wb")) == 0)
937 fatal_io_error ("can't open %s", bbg_file_name);
939 /* Initialize to zero, to ensure that the first file name will be
940 written to the .bb file. */
941 last_bb_file_name = 0;
944 if (flag_branch_probabilities)
948 len = strlen (filename);
949 da_file_name = (char *) alloca (len + 4);
950 strcpy (da_file_name, filename);
951 strip_off_ending (da_file_name, len);
952 strcat (da_file_name, ".da");
953 if ((da_file = fopen (da_file_name, "rb")) == 0)
954 warning ("file %s not found, execution counts assumed to be zero.",
957 /* The first word in the .da file gives the number of instrumented
958 edges, which is not needed for our purposes. */
961 __read_long (&len, da_file, 8);
964 if (profile_arc_flag)
965 init_edge_profiler ();
967 total_num_blocks = 0;
969 total_num_edges_ignored = 0;
970 total_num_edges_instrumented = 0;
971 total_num_blocks_created = 0;
972 total_num_passes = 0;
973 total_num_times_called = 0;
974 total_num_branches = 0;
975 total_num_never_executed = 0;
976 for (i = 0; i < 20; i++)
977 total_hist_br_prob[i] = 0;
980 /* Performs file-level cleanup after branch-prob processing
986 if (flag_test_coverage)
992 if (flag_branch_probabilities)
997 /* This seems slightly dangerous, as it presumes the EOF
998 flag will not be set until an attempt is made to read
999 past the end of the file. */
1001 error (".da file contents exhausted too early");
1002 /* Should be at end of file now. */
1003 if (__read_long (&temp, da_file, 8) == 0)
1004 error (".da file contents not exhausted");
1011 fprintf (rtl_dump_file, "\n");
1012 fprintf (rtl_dump_file, "Total number of blocks: %d\n",
1014 fprintf (rtl_dump_file, "Total number of edges: %d\n", total_num_edges);
1015 fprintf (rtl_dump_file, "Total number of ignored edges: %d\n",
1016 total_num_edges_ignored);
1017 fprintf (rtl_dump_file, "Total number of instrumented edges: %d\n",
1018 total_num_edges_instrumented);
1019 fprintf (rtl_dump_file, "Total number of blocks created: %d\n",
1020 total_num_blocks_created);
1021 fprintf (rtl_dump_file, "Total number of graph solution passes: %d\n",
1023 if (total_num_times_called != 0)
1024 fprintf (rtl_dump_file, "Average number of graph solution passes: %d\n",
1025 (total_num_passes + (total_num_times_called >> 1))
1026 / total_num_times_called);
1027 fprintf (rtl_dump_file, "Total number of branches: %d\n",
1028 total_num_branches);
1029 fprintf (rtl_dump_file, "Total number of branches never executed: %d\n",
1030 total_num_never_executed);
1031 if (total_num_branches)
1035 for (i = 0; i < 10; i++)
1036 fprintf (rtl_dump_file, "%d%% branches in range %d-%d%%\n",
1037 (total_hist_br_prob[i] + total_hist_br_prob[19-i]) * 100
1038 / total_num_branches, 5*i, 5*i+5);
1043 /* The label used by the edge profiling code. */
1045 static rtx profiler_label;
1047 /* Initialize the profiler_label. */
1050 init_edge_profiler ()
1052 /* Generate and save a copy of this so it can be shared. */
1054 ASM_GENERATE_INTERNAL_LABEL (buf, "LPBX", 2);
1055 profiler_label = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (buf));
1056 ggc_add_rtx_root (&profiler_label, 1);
1059 /* Output instructions as RTL to increment the edge execution count. */
1062 gen_edge_profiler (edgeno)
1065 enum machine_mode mode = mode_for_size (GCOV_TYPE_SIZE, MODE_INT, 0);
1071 tmp = force_reg (Pmode, profiler_label);
1072 tmp = plus_constant (tmp, GCOV_TYPE_SIZE / BITS_PER_UNIT * edgeno);
1073 mem_ref = validize_mem (gen_rtx_MEM (mode, tmp));
1075 tmp = expand_binop (mode, add_optab, mem_ref, const1_rtx,
1076 mem_ref, 0, OPTAB_WIDEN);
1079 emit_move_insn (copy_rtx (mem_ref), tmp);
1081 sequence = gen_sequence ();
1086 /* Output code for a constructor that will invoke __bb_init_func, if
1087 this has not already been done. */
1090 output_func_start_profiler ()
1092 tree fnname, fndecl;
1095 const char *cfnname;
1097 enum machine_mode mode = mode_for_size (GCOV_TYPE_SIZE, MODE_INT, 0);
1098 int save_flag_inline_functions = flag_inline_functions;
1099 int save_flag_test_coverage = flag_test_coverage;
1100 int save_profile_arc_flag = profile_arc_flag;
1101 int save_flag_branch_probabilities = flag_branch_probabilities;
1103 /* It's either already been output, or we don't need it because we're
1104 not doing profile-edges. */
1105 if (! need_func_profiler)
1108 need_func_profiler = 0;
1110 /* Synthesize a constructor function to invoke __bb_init_func with a
1111 pointer to this object file's profile block. */
1113 /* Try and make a unique name given the "file function name".
1115 And no, I don't like this either. */
1117 fnname = get_file_function_name ('I');
1118 cfnname = IDENTIFIER_POINTER (fnname);
1119 name = concat (cfnname, "GCOV", NULL);
1120 fnname = get_identifier (name);
1123 fndecl = build_decl (FUNCTION_DECL, fnname,
1124 build_function_type (void_type_node, NULL_TREE));
1125 DECL_EXTERNAL (fndecl) = 0;
1127 /* It can be a static function as long as collect2 does not have
1128 to scan the object file to find its ctor/dtor routine. */
1129 TREE_PUBLIC (fndecl) = ! targetm.have_ctors_dtors;
1131 TREE_USED (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 if (targetm.have_ctors_dtors)
1180 (* targetm.asm_out.constructor) (XEXP (DECL_RTL (fndecl), 0),
1181 DEFAULT_INIT_PRIORITY);