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"
53 /* Additional information about the edges we need. */
56 unsigned int count_valid : 1;
57 unsigned int on_tree : 1;
58 unsigned int ignore : 1;
62 unsigned int count_valid : 1;
67 #define EDGE_INFO(e) ((struct edge_info *) (e)->aux)
68 #define BB_INFO(b) ((struct bb_info *) (b)->aux)
70 /* Keep all basic block indexes nonnegative in the gcov output. Index 0
71 is used for entry block, last block exit block. */
72 #define GCOV_INDEX_TO_BB(i) ((i) == 0 ? ENTRY_BLOCK_PTR \
73 : (((i) == n_basic_blocks + 1) \
74 ? EXIT_BLOCK_PTR : BASIC_BLOCK ((i)-1)))
75 #define BB_TO_GCOV_INDEX(bb) ((bb) == ENTRY_BLOCK_PTR ? 0 \
76 : ((bb) == EXIT_BLOCK_PTR \
77 ? n_basic_blocks + 1 : (bb)->index + 1))
79 /* Name and file pointer of the output file for the basic block graph. */
81 static FILE *bbg_file;
83 /* Name and file pointer of the input file for the arc count data. */
87 /* Pointer of the output file for the basic block/line number map. */
90 /* Last source file name written to bb_file. */
92 static char *last_bb_file_name;
94 /* Used by final, for allocating the proper amount of storage for the
95 instrumented arc execution counts. */
97 int count_instrumented_edges;
99 /* Collect statistics on the performance of this pass for the entire source
102 static int total_num_blocks;
103 static int total_num_edges;
104 static int total_num_edges_ignored;
105 static int total_num_edges_instrumented;
106 static int total_num_blocks_created;
107 static int total_num_passes;
108 static int total_num_times_called;
109 static int total_hist_br_prob[20];
110 static int total_num_never_executed;
111 static int total_num_branches;
113 /* Forward declarations. */
114 static void find_spanning_tree PARAMS ((struct edge_list *));
115 static void init_edge_profiler PARAMS ((void));
116 static rtx gen_edge_profiler PARAMS ((int));
117 static void instrument_edges PARAMS ((struct edge_list *));
118 static void output_gcov_string PARAMS ((const char *, long));
119 static void compute_branch_probabilities PARAMS ((void));
120 static basic_block find_group PARAMS ((basic_block));
121 static void union_groups PARAMS ((basic_block, basic_block));
123 /* If non-zero, we need to output a constructor to set up the
124 per-object-file data. */
125 static int need_func_profiler = 0;
127 /* Add edge instrumentation code to the entire insn chain.
129 F is the first insn of the chain.
130 NUM_BLOCKS is the number of basic blocks found in F. */
133 instrument_edges (el)
134 struct edge_list *el;
137 int num_instr_edges = 0;
138 int num_edges = NUM_EDGES (el);
139 remove_fake_edges ();
141 for (i = 0; i < n_basic_blocks + 2; i++)
143 basic_block bb = GCOV_INDEX_TO_BB (i);
147 struct edge_info *inf = EDGE_INFO (e);
148 if (!inf->ignore && !inf->on_tree)
150 if (e->flags & EDGE_ABNORMAL)
153 fprintf (rtl_dump_file, "Edge %d to %d instrumented%s\n",
154 e->src->index, e->dest->index,
155 e->flags & EDGE_CRITICAL ? " (and split)" : "");
156 need_func_profiler = 1;
157 insert_insn_on_edge (
158 gen_edge_profiler (total_num_edges_instrumented
159 + num_instr_edges++), e);
165 total_num_edges_instrumented += num_instr_edges;
166 count_instrumented_edges = total_num_edges_instrumented;
168 total_num_blocks_created += num_edges;
170 fprintf (rtl_dump_file, "%d edges instrumented\n", num_instr_edges);
172 commit_edge_insertions ();
175 /* Output STRING to bb_file, surrounded by DELIMITER. */
178 output_gcov_string (string, delimiter)
184 /* Write a delimiter to indicate that a file name follows. */
185 __write_long (delimiter, bb_file, 4);
187 /* Write the string. */
188 temp = strlen (string) + 1;
189 fwrite (string, temp, 1, bb_file);
191 /* Append a few zeros, to align the output to a 4 byte boundary. */
197 c[0] = c[1] = c[2] = c[3] = 0;
198 fwrite (c, sizeof (char), 4 - temp, bb_file);
201 /* Store another delimiter in the .bb file, just to make it easy to find
202 the end of the file name. */
203 __write_long (delimiter, bb_file, 4);
207 /* Compute the branch probabilities for the various branches.
208 Annotate them accordingly. */
211 compute_branch_probabilities ()
217 int hist_br_prob[20];
218 int num_never_executed;
220 struct bb_info *bb_infos;
222 /* Attach extra info block to each bb. */
224 bb_infos = (struct bb_info *)
225 xcalloc (n_basic_blocks + 2, sizeof (struct bb_info));
226 for (i = 0; i < n_basic_blocks + 2; i++)
228 basic_block bb = GCOV_INDEX_TO_BB (i);
231 bb->aux = &bb_infos[i];
232 for (e = bb->succ; e; e = e->succ_next)
233 if (!EDGE_INFO (e)->ignore)
234 BB_INFO (bb)->succ_count++;
235 for (e = bb->pred; e; e = e->pred_next)
236 if (!EDGE_INFO (e)->ignore)
237 BB_INFO (bb)->pred_count++;
240 /* Avoid predicting entry on exit nodes. */
241 BB_INFO (EXIT_BLOCK_PTR)->succ_count = 2;
242 BB_INFO (ENTRY_BLOCK_PTR)->pred_count = 2;
244 /* For each edge not on the spanning tree, set its execution count from
247 /* The first count in the .da file is the number of times that the function
248 was entered. This is the exec_count for block zero. */
250 for (i = 0; i < n_basic_blocks + 2; i++)
252 basic_block bb = GCOV_INDEX_TO_BB (i);
254 for (e = bb->succ; e; e = e->succ_next)
255 if (!EDGE_INFO (e)->ignore && !EDGE_INFO (e)->on_tree)
261 __read_gcov_type (&value, da_file, 8);
266 EDGE_INFO (e)->count_valid = 1;
267 BB_INFO (bb)->succ_count--;
268 BB_INFO (e->dest)->pred_count--;
271 fprintf (rtl_dump_file, "\nRead edge from %i to %i, count:",
272 bb->index, e->dest->index);
273 fprintf (rtl_dump_file, HOST_WIDEST_INT_PRINT_DEC,
274 (HOST_WIDEST_INT) e->count);
280 fprintf (rtl_dump_file, "\n%d edge counts read\n", num_edges);
282 /* For every block in the file,
283 - if every exit/entrance edge has a known count, then set the block count
284 - if the block count is known, and every exit/entrance edge but one has
285 a known execution count, then set the count of the remaining edge
287 As edge counts are set, decrement the succ/pred count, but don't delete
288 the edge, that way we can easily tell when all edges are known, or only
289 one edge is unknown. */
291 /* The order that the basic blocks are iterated through is important.
292 Since the code that finds spanning trees starts with block 0, low numbered
293 edges are put on the spanning tree in preference to high numbered edges.
294 Hence, most instrumented edges are at the end. Graph solving works much
295 faster if we propagate numbers from the end to the start.
297 This takes an average of slightly more than 3 passes. */
305 for (i = n_basic_blocks + 1; i >= 0; i--)
307 basic_block bb = GCOV_INDEX_TO_BB (i);
308 struct bb_info *bi = BB_INFO (bb);
309 if (! bi->count_valid)
311 if (bi->succ_count == 0)
316 for (e = bb->succ; e; e = e->succ_next)
322 else if (bi->pred_count == 0)
327 for (e = bb->pred; e; e = e->pred_next)
336 if (bi->succ_count == 1)
341 /* One of the counts will be invalid, but it is zero,
342 so adding it in also doesn't hurt. */
343 for (e = bb->succ; e; e = e->succ_next)
346 /* Seedgeh for the invalid edge, and set its count. */
347 for (e = bb->succ; e; e = e->succ_next)
348 if (! EDGE_INFO (e)->count_valid && ! EDGE_INFO (e)->ignore)
351 /* Calculate count for remaining edge by conservation. */
352 total = bb->count - total;
356 EDGE_INFO (e)->count_valid = 1;
360 BB_INFO (e->dest)->pred_count--;
363 if (bi->pred_count == 1)
368 /* One of the counts will be invalid, but it is zero,
369 so adding it in also doesn't hurt. */
370 for (e = bb->pred; e; e = e->pred_next)
373 /* Seedgeh for the invalid edge, and set its count. */
374 for (e = bb->pred; e; e = e->pred_next)
375 if (! EDGE_INFO (e)->count_valid && ! EDGE_INFO (e)->ignore)
378 /* Calculate count for remaining edge by conservation. */
379 total = bb->count - total + e->count;
383 EDGE_INFO (e)->count_valid = 1;
387 BB_INFO (e->src)->succ_count--;
394 dump_flow_info (rtl_dump_file);
396 total_num_passes += passes;
398 fprintf (rtl_dump_file, "Graph solving took %d passes.\n\n", passes);
400 /* If the graph has been correctly solved, every block will have a
401 succ and pred count of zero. */
402 for (i = 0; i < n_basic_blocks; i++)
404 basic_block bb = BASIC_BLOCK (i);
405 if (BB_INFO (bb)->succ_count || BB_INFO (bb)->pred_count)
409 /* For every edge, calculate its branch probability and add a reg_note
410 to the branch insn to indicate this. */
412 for (i = 0; i < 20; i++)
414 num_never_executed = 0;
417 for (i = 0; i < n_basic_blocks; i++)
419 basic_block bb = BASIC_BLOCK (i);
426 for (e = bb->succ; e; e = e->succ_next)
428 e->probability = (e->count * REG_BR_PROB_BASE + total / 2) / total;
429 if (e->probability < 0 || e->probability > REG_BR_PROB_BASE)
431 error ("Corrupted profile info: prob for %d-%d thought to be %d\n",
432 e->src->index, e->dest->index, e->probability);
433 e->probability = REG_BR_PROB_BASE / 2;
436 if (any_condjump_p (bb->end)
437 && bb->succ->succ_next)
446 num_never_executed++;
451 /* Find the branch edge. It is possible that we do have fake
453 for (e = bb->succ; e->flags & (EDGE_FAKE | EDGE_FALLTHRU);
455 continue; /* Loop body has been intentionally left blank. */
457 prob = e->probability;
458 index = prob * 20 / REG_BR_PROB_BASE;
462 hist_br_prob[index]++;
464 note = find_reg_note (bb->end, REG_BR_PROB, 0);
465 /* There may be already note put by some other pass, such
466 as builtin_expect expander. */
468 XEXP (note, 0) = GEN_INT (prob);
471 = gen_rtx_EXPR_LIST (REG_BR_PROB, GEN_INT (prob),
472 REG_NOTES (bb->end));
481 fprintf (rtl_dump_file, "%d branches\n", num_branches);
482 fprintf (rtl_dump_file, "%d branches never executed\n",
485 for (i = 0; i < 10; i++)
486 fprintf (rtl_dump_file, "%d%% branches in range %d-%d%%\n",
487 (hist_br_prob[i] + hist_br_prob[19-i]) * 100 / num_branches,
490 total_num_branches += num_branches;
491 total_num_never_executed += num_never_executed;
492 for (i = 0; i < 20; i++)
493 total_hist_br_prob[i] += hist_br_prob[i];
495 fputc ('\n', rtl_dump_file);
496 fputc ('\n', rtl_dump_file);
502 /* Instrument and/or analyze program behavior based on program flow graph.
503 In either case, this function builds a flow graph for the function being
504 compiled. The flow graph is stored in BB_GRAPH.
506 When FLAG_PROFILE_ARCS is nonzero, this function instruments the edges in
507 the flow graph that are needed to reconstruct the dynamic behavior of the
510 When FLAG_BRANCH_PROBABILITIES is nonzero, this function reads auxiliary
511 information from a data file containing edge count information from previous
512 executions of the function being compiled. In this case, the flow graph is
513 annotated with actual execution counts, which are later propagated into the
514 rtl for optimization purposes.
516 Main entry point of this file. */
522 int num_edges, ignored_edges;
523 struct edge_info *edge_infos;
524 struct edge_list *el;
526 /* Start of a function. */
527 if (flag_test_coverage)
528 output_gcov_string (current_function_name, (long) -2);
530 total_num_times_called++;
532 flow_call_edges_add (NULL);
534 /* We can't handle cyclic regions constructed using abnormal edges.
535 To avoid these we replace every source of abnormal edge by a fake
536 edge from entry node and every destination by fake edge to exit.
537 This keeps graph acyclic and our calculation exact for all normal
538 edges except for exit and entrance ones.
540 We also add fake exit edges for each call and asm statement in the
541 basic, since it may not return. */
543 for (i = 0; i < n_basic_blocks ; i++)
545 int need_exit_edge = 0, need_entry_edge = 0;
546 int have_exit_edge = 0, have_entry_edge = 0;
547 basic_block bb = BASIC_BLOCK (i);
551 /* Add fake edges from entry block to the call insns that may return
552 twice. The CFG is not quite correct then, as call insn plays more
553 role of CODE_LABEL, but for our purposes, everything should be OK,
554 as we never insert code to the beggining of basic block. */
555 for (insn = bb->head; insn != NEXT_INSN (bb->end);
556 insn = NEXT_INSN (insn))
558 if (GET_CODE (insn) == CALL_INSN
559 && find_reg_note (insn, REG_SETJMP, NULL))
561 if (GET_CODE (bb->head) == CODE_LABEL
562 || insn != NEXT_INSN (bb->head))
564 e = split_block (bb, PREV_INSN (insn));
565 make_edge (NULL, ENTRY_BLOCK_PTR, e->dest, EDGE_FAKE);
570 /* We should not get abort here, as call to setjmp should not
571 be the very first instruction of function. */
574 make_edge (NULL, ENTRY_BLOCK_PTR, bb, EDGE_FAKE);
579 for (e = bb->succ; e; e = e->succ_next)
581 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
582 && e->dest != EXIT_BLOCK_PTR)
584 if (e->dest == EXIT_BLOCK_PTR)
587 for (e = bb->pred; e; e = e->pred_next)
589 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
590 && e->src != ENTRY_BLOCK_PTR)
592 if (e->src == ENTRY_BLOCK_PTR)
596 if (need_exit_edge && !have_exit_edge)
599 fprintf (rtl_dump_file, "Adding fake exit edge to bb %i\n",
601 make_edge (NULL, bb, EXIT_BLOCK_PTR, EDGE_FAKE);
603 if (need_entry_edge && !have_entry_edge)
606 fprintf (rtl_dump_file, "Adding fake entry edge to bb %i\n",
608 make_edge (NULL, ENTRY_BLOCK_PTR, bb, EDGE_FAKE);
612 el = create_edge_list ();
613 num_edges = NUM_EDGES (el);
614 edge_infos = (struct edge_info *)
615 xcalloc (num_edges, sizeof (struct edge_info));
618 for (i = 0 ; i < num_edges ; i++)
620 edge e = INDEX_EDGE (el, i);
622 e->aux = &edge_infos[i];
624 /* Mark edges we've replaced by fake edges above as ignored. */
625 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
626 && e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR)
628 EDGE_INFO (e)->ignore = 1;
633 #ifdef ENABLE_CHECKING
637 /* Output line number information about each basic block for
639 if (flag_test_coverage)
642 for (i = 0 ; i < n_basic_blocks; i++)
644 basic_block bb = BASIC_BLOCK (i);
646 static int ignore_next_note = 0;
648 /* We are looking for line number notes. Search backward before
649 basic block to find correct ones. */
650 insn = prev_nonnote_insn (insn);
654 insn = NEXT_INSN (insn);
656 /* Output a zero to the .bb file to indicate that a new
657 block list is starting. */
658 __write_long (0, bb_file, 4);
660 while (insn != bb->end)
662 if (GET_CODE (insn) == NOTE)
664 /* Must ignore the line number notes that immediately
665 follow the end of an inline function to avoid counting
666 it twice. There is a note before the call, and one
668 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_REPEATED_LINE_NUMBER)
669 ignore_next_note = 1;
670 else if (NOTE_LINE_NUMBER (insn) > 0)
672 if (ignore_next_note)
673 ignore_next_note = 0;
676 /* If this is a new source file, then output the
677 file's name to the .bb file. */
678 if (! last_bb_file_name
679 || strcmp (NOTE_SOURCE_FILE (insn),
682 if (last_bb_file_name)
683 free (last_bb_file_name);
685 = xstrdup (NOTE_SOURCE_FILE (insn));
686 output_gcov_string (NOTE_SOURCE_FILE (insn),
689 /* Output the line number to the .bb file. Must be
690 done after the output_bb_profile_data() call, and
691 after the file name is written, to ensure that it
692 is correctly handled by gcov. */
693 __write_long (NOTE_LINE_NUMBER (insn), bb_file, 4);
697 insn = NEXT_INSN (insn);
700 __write_long (0, bb_file, 4);
703 /* Create spanning tree from basic block graph, mark each edge that is
704 on the spanning tree. We insert as many abnormal and critical edges
705 as possible to minimize number of edge splits necesary. */
707 find_spanning_tree (el);
709 /* Fake edges that are not on the tree will not be instrumented, so
710 mark them ignored. */
711 for (i = 0; i < num_edges; i++)
713 edge e = INDEX_EDGE (el, i);
714 struct edge_info *inf = EDGE_INFO (e);
715 if ((e->flags & EDGE_FAKE) && !inf->ignore && !inf->on_tree)
722 total_num_blocks += n_basic_blocks + 2;
724 fprintf (rtl_dump_file, "%d basic blocks\n", n_basic_blocks);
726 total_num_edges += num_edges;
728 fprintf (rtl_dump_file, "%d edges\n", num_edges);
730 total_num_edges_ignored += ignored_edges;
732 fprintf (rtl_dump_file, "%d ignored edges\n", ignored_edges);
734 /* Create a .bbg file from which gcov can reconstruct the basic block
735 graph. First output the number of basic blocks, and then for every
736 edge output the source and target basic block numbers.
737 NOTE: The format of this file must be compatible with gcov. */
739 if (flag_test_coverage)
743 /* The plus 2 stands for entry and exit block. */
744 __write_long (n_basic_blocks + 2, bbg_file, 4);
745 __write_long (num_edges - ignored_edges + 1, bbg_file, 4);
747 for (i = 0; i < n_basic_blocks + 1; i++)
749 basic_block bb = GCOV_INDEX_TO_BB (i);
753 for (e = bb->succ; e; e = e->succ_next)
754 if (!EDGE_INFO (e)->ignore)
756 __write_long (count, bbg_file, 4);
758 for (e = bb->succ; e; e = e->succ_next)
760 struct edge_info *i = EDGE_INFO (e);
766 if (e->flags & EDGE_FAKE)
768 if (e->flags & EDGE_FALLTHRU)
771 __write_long (BB_TO_GCOV_INDEX (e->dest), bbg_file, 4);
772 __write_long (flag_bits, bbg_file, 4);
776 /* Emit fake loopback edge for EXIT block to maitain compatibility with
778 __write_long (1, bbg_file, 4);
779 __write_long (0, bbg_file, 4);
780 __write_long (0x1, bbg_file, 4);
782 /* Emit a -1 to separate the list of all edges from the list of
783 loop back edges that follows. */
784 __write_long (-1, bbg_file, 4);
787 if (flag_branch_probabilities)
788 compute_branch_probabilities ();
790 /* For each edge not on the spanning tree, add counting code as rtl. */
792 if (profile_arc_flag)
794 instrument_edges (el);
795 allocate_reg_info (max_reg_num (), FALSE, FALSE);
798 remove_fake_edges ();
799 /* Re-merge split basic blocks and the mess introduced by
800 insert_insn_on_edge. */
801 cleanup_cfg (profile_arc_flag ? CLEANUP_EXPENSIVE : 0);
803 dump_flow_info (rtl_dump_file);
809 /* Union find algorithm implementation for the basic blocks using
816 basic_block group = bb, bb1;
818 while ((basic_block) group->aux != group)
819 group = (basic_block) group->aux;
822 while ((basic_block) bb->aux != group)
824 bb1 = (basic_block) bb->aux;
825 bb->aux = (void *) group;
832 union_groups (bb1, bb2)
833 basic_block bb1, bb2;
835 basic_block bb1g = find_group (bb1);
836 basic_block bb2g = find_group (bb2);
838 /* ??? I don't have a place for the rank field. OK. Lets go w/o it,
839 this code is unlikely going to be performance problem anyway. */
846 /* This function searches all of the edges in the program flow graph, and puts
847 as many bad edges as possible onto the spanning tree. Bad edges include
848 abnormals edges, which can't be instrumented at the moment. Since it is
849 possible for fake edges to form an cycle, we will have to develop some
850 better way in the future. Also put critical edges to the tree, since they
851 are more expensive to instrument. */
854 find_spanning_tree (el)
855 struct edge_list *el;
858 int num_edges = NUM_EDGES (el);
860 /* We use aux field for standard union-find algorithm. */
861 EXIT_BLOCK_PTR->aux = EXIT_BLOCK_PTR;
862 ENTRY_BLOCK_PTR->aux = ENTRY_BLOCK_PTR;
863 for (i = 0; i < n_basic_blocks; i++)
864 BASIC_BLOCK (i)->aux = BASIC_BLOCK (i);
866 /* Add fake edge exit to entry we can't instrument. */
867 union_groups (EXIT_BLOCK_PTR, ENTRY_BLOCK_PTR);
869 /* First add all abnormal edges to the tree unless they form an cycle. */
870 for (i = 0; i < num_edges; i++)
872 edge e = INDEX_EDGE (el, i);
873 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_FAKE))
874 && !EDGE_INFO (e)->ignore
875 && (find_group (e->src) != find_group (e->dest)))
877 EDGE_INFO (e)->on_tree = 1;
878 union_groups (e->src, e->dest);
882 /* Now insert all critical edges to the tree unless they form an cycle. */
883 for (i = 0; i < num_edges; i++)
885 edge e = INDEX_EDGE (el, i);
886 if ((e->flags & EDGE_CRITICAL)
887 && !EDGE_INFO (e)->ignore
888 && (find_group (e->src) != find_group (e->dest)))
890 EDGE_INFO (e)->on_tree = 1;
891 union_groups (e->src, e->dest);
895 /* And now the rest. */
896 for (i = 0; i < num_edges; i++)
898 edge e = INDEX_EDGE (el, i);
899 if (find_group (e->src) != find_group (e->dest)
900 && !EDGE_INFO (e)->ignore)
902 EDGE_INFO (e)->on_tree = 1;
903 union_groups (e->src, e->dest);
908 /* Perform file-level initialization for branch-prob processing. */
911 init_branch_prob (filename)
912 const char *filename;
917 if (flag_test_coverage)
919 int len = strlen (filename);
920 char *data_file, *bbg_file_name;
922 /* Open an output file for the basic block/line number map. */
923 data_file = (char *) alloca (len + 4);
924 strcpy (data_file, filename);
925 strip_off_ending (data_file, len);
926 strcat (data_file, ".bb");
927 if ((bb_file = fopen (data_file, "wb")) == 0)
928 fatal_io_error ("can't open %s", data_file);
930 /* Open an output file for the program flow graph. */
931 bbg_file_name = (char *) alloca (len + 5);
932 strcpy (bbg_file_name, filename);
933 strip_off_ending (bbg_file_name, len);
934 strcat (bbg_file_name, ".bbg");
935 if ((bbg_file = fopen (bbg_file_name, "wb")) == 0)
936 fatal_io_error ("can't open %s", bbg_file_name);
938 /* Initialize to zero, to ensure that the first file name will be
939 written to the .bb file. */
940 last_bb_file_name = 0;
943 if (flag_branch_probabilities)
947 len = strlen (filename);
948 da_file_name = (char *) alloca (len + 4);
949 strcpy (da_file_name, filename);
950 strip_off_ending (da_file_name, len);
951 strcat (da_file_name, ".da");
952 if ((da_file = fopen (da_file_name, "rb")) == 0)
953 warning ("file %s not found, execution counts assumed to be zero.",
956 /* The first word in the .da file gives the number of instrumented
957 edges, which is not needed for our purposes. */
960 __read_long (&len, da_file, 8);
963 if (profile_arc_flag)
964 init_edge_profiler ();
966 total_num_blocks = 0;
968 total_num_edges_ignored = 0;
969 total_num_edges_instrumented = 0;
970 total_num_blocks_created = 0;
971 total_num_passes = 0;
972 total_num_times_called = 0;
973 total_num_branches = 0;
974 total_num_never_executed = 0;
975 for (i = 0; i < 20; i++)
976 total_hist_br_prob[i] = 0;
979 /* Performs file-level cleanup after branch-prob processing
985 if (flag_test_coverage)
991 if (flag_branch_probabilities)
996 /* This seems slightly dangerous, as it presumes the EOF
997 flag will not be set until an attempt is made to read
998 past the end of the file. */
1000 error (".da file contents exhausted too early");
1001 /* Should be at end of file now. */
1002 if (__read_long (&temp, da_file, 8) == 0)
1003 error (".da file contents not exhausted");
1010 fprintf (rtl_dump_file, "\n");
1011 fprintf (rtl_dump_file, "Total number of blocks: %d\n",
1013 fprintf (rtl_dump_file, "Total number of edges: %d\n", total_num_edges);
1014 fprintf (rtl_dump_file, "Total number of ignored edges: %d\n",
1015 total_num_edges_ignored);
1016 fprintf (rtl_dump_file, "Total number of instrumented edges: %d\n",
1017 total_num_edges_instrumented);
1018 fprintf (rtl_dump_file, "Total number of blocks created: %d\n",
1019 total_num_blocks_created);
1020 fprintf (rtl_dump_file, "Total number of graph solution passes: %d\n",
1022 if (total_num_times_called != 0)
1023 fprintf (rtl_dump_file, "Average number of graph solution passes: %d\n",
1024 (total_num_passes + (total_num_times_called >> 1))
1025 / total_num_times_called);
1026 fprintf (rtl_dump_file, "Total number of branches: %d\n",
1027 total_num_branches);
1028 fprintf (rtl_dump_file, "Total number of branches never executed: %d\n",
1029 total_num_never_executed);
1030 if (total_num_branches)
1034 for (i = 0; i < 10; i++)
1035 fprintf (rtl_dump_file, "%d%% branches in range %d-%d%%\n",
1036 (total_hist_br_prob[i] + total_hist_br_prob[19-i]) * 100
1037 / total_num_branches, 5*i, 5*i+5);
1042 /* The label used by the edge profiling code. */
1044 static rtx profiler_label;
1046 /* Initialize the profiler_label. */
1049 init_edge_profiler ()
1051 /* Generate and save a copy of this so it can be shared. */
1053 ASM_GENERATE_INTERNAL_LABEL (buf, "LPBX", 2);
1054 profiler_label = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (buf));
1055 ggc_add_rtx_root (&profiler_label, 1);
1058 /* Output instructions as RTL to increment the edge execution count. */
1061 gen_edge_profiler (edgeno)
1064 enum machine_mode mode = mode_for_size (GCOV_TYPE_SIZE, MODE_INT, 0);
1070 tmp = force_reg (Pmode, profiler_label);
1071 tmp = plus_constant (tmp, GCOV_TYPE_SIZE / BITS_PER_UNIT * edgeno);
1072 mem_ref = validize_mem (gen_rtx_MEM (mode, tmp));
1074 tmp = expand_simple_binop (mode, PLUS, mem_ref, const1_rtx,
1075 mem_ref, 0, OPTAB_WIDEN);
1078 emit_move_insn (copy_rtx (mem_ref), tmp);
1080 sequence = gen_sequence ();
1085 /* Output code for a constructor that will invoke __bb_init_func, if
1086 this has not already been done. */
1089 output_func_start_profiler ()
1091 tree fnname, fndecl;
1094 const char *cfnname;
1096 enum machine_mode mode = mode_for_size (GCOV_TYPE_SIZE, MODE_INT, 0);
1097 int save_flag_inline_functions = flag_inline_functions;
1098 int save_flag_test_coverage = flag_test_coverage;
1099 int save_profile_arc_flag = profile_arc_flag;
1100 int save_flag_branch_probabilities = flag_branch_probabilities;
1102 /* It's either already been output, or we don't need it because we're
1103 not doing profile-edges. */
1104 if (! need_func_profiler)
1107 need_func_profiler = 0;
1109 /* Synthesize a constructor function to invoke __bb_init_func with a
1110 pointer to this object file's profile block. */
1112 /* Try and make a unique name given the "file function name".
1114 And no, I don't like this either. */
1116 fnname = get_file_function_name ('I');
1117 cfnname = IDENTIFIER_POINTER (fnname);
1118 name = concat (cfnname, "GCOV", NULL);
1119 fnname = get_identifier (name);
1122 fndecl = build_decl (FUNCTION_DECL, fnname,
1123 build_function_type (void_type_node, NULL_TREE));
1124 DECL_EXTERNAL (fndecl) = 0;
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) = ! targetm.have_ctors_dtors;
1130 TREE_USED (fndecl) = 1;
1132 DECL_RESULT (fndecl) = build_decl (RESULT_DECL, NULL_TREE, void_type_node);
1134 fndecl = pushdecl (fndecl);
1135 rest_of_decl_compilation (fndecl, 0, 1, 0);
1136 announce_function (fndecl);
1137 current_function_decl = fndecl;
1138 DECL_INITIAL (fndecl) = error_mark_node;
1139 make_decl_rtl (fndecl, NULL);
1140 init_function_start (fndecl, input_filename, lineno);
1142 expand_function_start (fndecl, 0);
1144 /* Actually generate the code to call __bb_init_func. */
1145 ASM_GENERATE_INTERNAL_LABEL (buf, "LPBX", 0);
1146 table_address = force_reg (Pmode,
1147 gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (buf)));
1148 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__bb_init_func"), 0,
1149 mode, 1, table_address, Pmode);
1151 expand_function_end (input_filename, lineno, 0);
1154 /* Since fndecl isn't in the list of globals, it would never be emitted
1155 when it's considered to be 'safe' for inlining, so turn off
1156 flag_inline_functions. */
1157 flag_inline_functions = 0;
1159 /* Don't instrument the function that turns on instrumentation. Which
1160 is also handy since we'd get silly warnings about not consuming all
1161 of our da_file input. */
1162 flag_test_coverage = 0;
1163 profile_arc_flag = 0;
1164 flag_branch_probabilities = 0;
1166 rest_of_compilation (fndecl);
1168 /* Reset flag_inline_functions to its original value. */
1169 flag_inline_functions = save_flag_inline_functions;
1170 flag_test_coverage = save_flag_test_coverage;
1171 profile_arc_flag = save_profile_arc_flag;
1172 flag_branch_probabilities = save_flag_branch_probabilities;
1175 fflush (asm_out_file);
1176 current_function_decl = NULL_TREE;
1178 if (targetm.have_ctors_dtors)
1179 (* targetm.asm_out.constructor) (XEXP (DECL_RTL (fndecl), 0),
1180 DEFAULT_INIT_PRIORITY);