1 /* Calculate branch probabilities, and basic block execution counts.
2 Copyright (C) 1990, 91-94, 96-99, 2000 Free Software Foundation, Inc.
3 Contributed by James E. Wilson, UC Berkeley/Cygnus Support;
4 based on some ideas from Dain Samples of UC Berkeley.
5 Further mangling by Bob Manson, Cygnus Support.
7 This file is part of GNU CC.
9 GNU CC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2, or (at your option)
14 GNU CC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GNU CC; see the file COPYING. If not, write to
21 the Free Software Foundation, 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
24 /* ??? Register allocation should use basic block execution counts to
25 give preference to the most commonly executed blocks. */
27 /* ??? The .da files are not safe. Changing the program after creating .da
28 files or using different options when compiling with -fbranch-probabilities
29 can result the arc data not matching the program. Maybe add instrumented
30 arc count to .bbg file? Maybe check whether PFG matches the .bbg file? */
32 /* ??? Should calculate branch probabilities before instrumenting code, since
33 then we can use arc counts to help decide which arcs to instrument. */
40 #include "insn-flags.h"
41 #include "insn-config.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_instrumented;
104 static int total_num_blocks_created;
105 static int total_num_passes;
106 static int total_num_times_called;
107 static int total_hist_br_prob[20];
108 static int total_num_never_executed;
109 static int total_num_branches;
111 /* Forward declarations. */
112 static void find_spanning_tree PARAMS ((struct edge_list *));
113 static void init_edge_profiler PARAMS ((void));
114 static rtx gen_edge_profiler PARAMS ((int));
115 static void instrument_edges PARAMS ((struct edge_list *));
116 static void output_gcov_string PARAMS ((const char *, long));
117 static void compute_branch_probabilities PARAMS ((void));
118 static basic_block find_group PARAMS ((basic_block));
119 static void union_groups PARAMS ((basic_block, basic_block));
121 #ifndef LONG_TYPE_SIZE
122 #define LONG_TYPE_SIZE BITS_PER_WORD
125 /* If non-zero, we need to output a constructor to set up the
126 per-object-file data. */
127 static int need_func_profiler = 0;
129 /* Add edge instrumentation code to the entire insn chain.
131 F is the first insn of the chain.
132 NUM_BLOCKS is the number of basic blocks found in F. */
135 instrument_edges (el)
136 struct edge_list *el;
139 int num_instr_edges = 0;
140 int num_edges = NUM_EDGES (el);
141 remove_fake_edges ();
143 for (i = 0; i < n_basic_blocks + 2; i++)
145 basic_block bb = GCOV_INDEX_TO_BB (i);
149 struct edge_info *inf = EDGE_INFO (e);
150 if (!inf->ignore && !inf->on_tree)
152 if (e->flags & EDGE_ABNORMAL)
155 fprintf (rtl_dump_file, "Edge %d to %d instrumented%s\n",
156 e->src->index, e->dest->index,
157 e->flags & EDGE_CRITICAL ? " (and split)" : "");
158 need_func_profiler = 1;
159 insert_insn_on_edge (
160 gen_edge_profiler (total_num_edges_instrumented
161 + num_instr_edges++), e);
167 total_num_edges_instrumented += num_instr_edges;
168 count_instrumented_edges = total_num_edges_instrumented;
170 total_num_blocks_created += num_edges;
172 fprintf (rtl_dump_file, "%d edges instrumented\n", num_instr_edges);
174 commit_edge_insertions ();
177 /* Output STRING to bb_file, surrounded by DELIMITER. */
180 output_gcov_string (string, delimiter)
186 /* Write a delimiter to indicate that a file name follows. */
187 __write_long (delimiter, bb_file, 4);
189 /* Write the string. */
190 temp = strlen (string) + 1;
191 fwrite (string, temp, 1, bb_file);
193 /* Append a few zeros, to align the output to a 4 byte boundary. */
199 c[0] = c[1] = c[2] = c[3] = 0;
200 fwrite (c, sizeof (char), 4 - temp, bb_file);
203 /* Store another delimiter in the .bb file, just to make it easy to find
204 the end of the file name. */
205 __write_long (delimiter, bb_file, 4);
209 /* Compute the branch probabilities for the various branches.
210 Annotate them accordingly. */
213 compute_branch_probabilities ()
219 int hist_br_prob[20];
220 int num_never_executed;
223 struct bb_info *bb_infos;
225 /* Attach extra info block to each bb. */
227 bb_infos = (struct bb_info *)
228 xcalloc (n_basic_blocks + 2, sizeof (struct bb_info));
229 for (i = 0; i < n_basic_blocks + 2; i++)
231 basic_block bb = GCOV_INDEX_TO_BB (i);
234 bb->aux = &bb_infos[i];
235 for (e = bb->succ; e; e = e->succ_next)
236 if (!EDGE_INFO (e)->ignore)
237 BB_INFO (bb)->succ_count++;
238 for (e = bb->pred; e; e = e->pred_next)
239 if (!EDGE_INFO (e)->ignore)
240 BB_INFO (bb)->pred_count++;
243 /* Avoid predicting entry on exit nodes. */
244 BB_INFO (EXIT_BLOCK_PTR)->succ_count = 2;
245 BB_INFO (ENTRY_BLOCK_PTR)->pred_count = 2;
247 /* For each edge not on the spanning tree, set its execution count from
250 /* The first count in the .da file is the number of times that the function
251 was entered. This is the exec_count for block zero. */
253 for (i = 0; i < n_basic_blocks + 2; i++)
255 basic_block bb = GCOV_INDEX_TO_BB (i);
257 for (e = bb->succ; e; e = e->succ_next)
258 if (!EDGE_INFO (e)->ignore && !EDGE_INFO (e)->on_tree)
264 __read_long (&value, da_file, 8);
269 EDGE_INFO (e)->count_valid = 1;
270 BB_INFO (bb)->succ_count--;
271 BB_INFO (e->dest)->pred_count--;
276 fprintf (rtl_dump_file, "%d edge counts read\n", num_edges);
278 /* For every block in the file,
279 - if every exit/entrance edge has a known count, then set the block count
280 - if the block count is known, and every exit/entrance edge but one has
281 a known execution count, then set the count of the remaining edge
283 As edge counts are set, decrement the succ/pred count, but don't delete
284 the edge, that way we can easily tell when all edges are known, or only
285 one edge is unknown. */
287 /* The order that the basic blocks are iterated through is important.
288 Since the code that finds spanning trees starts with block 0, low numbered
289 edges are put on the spanning tree in preference to high numbered edges.
290 Hence, most instrumented edges are at the end. Graph solving works much
291 faster if we propagate numbers from the end to the start.
293 This takes an average of slightly more than 3 passes. */
301 for (i = n_basic_blocks + 1; i >= 0; i--)
303 basic_block bb = GCOV_INDEX_TO_BB (i);
304 struct bb_info *bi = BB_INFO (bb);
305 if (! bi->count_valid)
307 if (bi->succ_count == 0)
312 for (e = bb->succ; e; e = e->succ_next)
318 else if (bi->pred_count == 0)
323 for (e = bb->pred; e; e = e->pred_next)
332 if (bi->succ_count == 1)
337 /* One of the counts will be invalid, but it is zero,
338 so adding it in also doesn't hurt. */
339 for (e = bb->succ; e; e = e->succ_next)
342 /* Seedgeh for the invalid edge, and set its count. */
343 for (e = bb->succ; e; e = e->succ_next)
344 if (! EDGE_INFO (e)->count_valid && ! EDGE_INFO (e)->ignore)
347 /* Calculate count for remaining edge by conservation. */
348 total = bb->count - total;
352 EDGE_INFO (e)->count_valid = 1;
356 BB_INFO (e->dest)->pred_count--;
359 if (bi->pred_count == 1)
364 /* One of the counts will be invalid, but it is zero,
365 so adding it in also doesn't hurt. */
366 for (e = bb->pred; e; e = e->pred_next)
369 /* Seedgeh for the invalid edge, and set its count. */
370 for (e = bb->pred; e; e = e->pred_next)
371 if (! EDGE_INFO (e)->count_valid && ! EDGE_INFO (e)->ignore)
374 /* Calculate count for remaining edge by conservation. */
375 total = bb->count - total + e->count;
379 EDGE_INFO (e)->count_valid = 1;
383 BB_INFO (e->src)->succ_count--;
390 dump_flow_info (rtl_dump_file);
392 total_num_passes += passes;
394 fprintf (rtl_dump_file, "Graph solving took %d passes.\n\n", passes);
396 /* If the graph has been correctly solved, every block will have a
397 succ and pred count of zero. */
398 for (i = 0; i < n_basic_blocks; i++)
400 basic_block bb = BASIC_BLOCK (i);
401 if (BB_INFO (bb)->succ_count || BB_INFO (bb)->pred_count)
405 /* For every edge, calculate its branch probability and add a reg_note
406 to the branch insn to indicate this. */
408 for (i = 0; i < 20; i++)
410 num_never_executed = 0;
413 for (i = 0; i < n_basic_blocks; i++)
415 basic_block bb = BASIC_BLOCK (i);
424 for (e = bb->succ; e; e = e->succ_next)
426 if (any_condjump_p (e->src->end)
427 && !EDGE_INFO (e)->ignore
428 && !(e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_FAKE)))
431 /* This calculates the branch probability as an integer between
432 0 and REG_BR_PROB_BASE, properly rounded to the nearest
433 integer. Perform the arithmetic in double to avoid
434 overflowing the range of ints. */
439 prob = (((double)e->count * REG_BR_PROB_BASE)
440 + (total >> 1)) / total;
441 if (prob < 0 || prob > REG_BR_PROB_BASE)
444 fprintf (rtl_dump_file, "bad count: prob for %d-%d thought to be %d (forcibly normalized)\n",
445 e->src->index, e->dest->index, prob);
448 prob = REG_BR_PROB_BASE / 2;
451 /* Match up probability with JUMP pattern. */
452 if (e->flags & EDGE_FALLTHRU)
453 prob = REG_BR_PROB_BASE - prob;
457 num_never_executed++;
460 int index = prob * 20 / REG_BR_PROB_BASE;
463 hist_br_prob[index]++;
467 note = find_reg_note (e->src->end, REG_BR_PROB, 0);
468 /* There may be already note put by some other pass, such
469 as builtin_expect expander. */
471 XEXP (note, 0) = GEN_INT (prob);
473 REG_NOTES (e->src->end)
474 = gen_rtx_EXPR_LIST (REG_BR_PROB, GEN_INT (prob),
475 REG_NOTES (e->src->end));
479 /* Add a REG_EXEC_COUNT note to the first instruction of this block. */
480 insn = next_nonnote_insn (bb->head);
482 if (GET_CODE (bb->head) == CODE_LABEL)
483 insn = next_nonnote_insn (insn);
485 /* Avoid crash on empty basic blocks. */
486 if (insn && INSN_P (insn))
488 = gen_rtx_EXPR_LIST (REG_EXEC_COUNT, GEN_INT (total),
492 /* This should never happen. */
494 warning ("Arc profiling: some edge counts were bad.");
498 fprintf (rtl_dump_file, "%d branches\n", num_branches);
499 fprintf (rtl_dump_file, "%d branches never executed\n",
502 for (i = 0; i < 10; i++)
503 fprintf (rtl_dump_file, "%d%% branches in range %d-%d%%\n",
504 (hist_br_prob[i] + hist_br_prob[19-i]) * 100 / num_branches,
507 total_num_branches += num_branches;
508 total_num_never_executed += num_never_executed;
509 for (i = 0; i < 20; i++)
510 total_hist_br_prob[i] += hist_br_prob[i];
512 fputc ('\n', rtl_dump_file);
513 fputc ('\n', rtl_dump_file);
519 /* Instrument and/or analyze program behavior based on program flow graph.
520 In either case, this function builds a flow graph for the function being
521 compiled. The flow graph is stored in BB_GRAPH.
523 When FLAG_PROFILE_ARCS is nonzero, this function instruments the edges in
524 the flow graph that are needed to reconstruct the dynamic behavior of the
527 When FLAG_BRANCH_PROBABILITIES is nonzero, this function reads auxiliary
528 information from a data file containing edge count information from previous
529 executions of the function being compiled. In this case, the flow graph is
530 annotated with actual execution counts, which are later propagated into the
531 rtl for optimization purposes.
533 Main entry point of this file. */
540 struct edge_info *edge_infos;
541 struct edge_list *el;
543 /* Start of a function. */
544 if (flag_test_coverage)
545 output_gcov_string (current_function_name, (long) -2);
547 total_num_times_called++;
549 /* We can't handle cyclic regions constructed using abnormal edges.
550 To avoid these we replace every source of abnormal edge by a fake
551 edge from entry node and every destination by fake edge to exit.
552 This keeps graph acyclic and our calculation exact for all normal
553 edges except for exit and entrance ones.
555 We also add fake exit edges for each call and asm statement in the
556 basic, since it may not return. */
558 for (i = 0; i < n_basic_blocks ; i++)
561 int need_exit_edge = 0, need_entry_edge = 0;
562 int have_exit_edge = 0, have_entry_edge = 0;
563 basic_block bb = BASIC_BLOCK (i);
566 for (e = bb->succ; e; e = e->succ_next)
568 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
569 && e->dest != EXIT_BLOCK_PTR)
571 if (e->dest == EXIT_BLOCK_PTR)
574 for (e = bb->pred; e; e = e->pred_next)
576 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
577 && e->src != ENTRY_BLOCK_PTR)
579 if (e->src == ENTRY_BLOCK_PTR)
583 /* ??? Not strictly needed unless flag_test_coverage, but adding
584 them anyway keeps the .da file consistent. */
585 /* ??? Currently inexact for basic blocks with multiple calls.
586 We need to split blocks here. */
587 for (insn = bb->head;
588 insn != NEXT_INSN (bb->end);
589 insn = NEXT_INSN (insn))
592 if (GET_CODE (insn) == CALL_INSN && !CONST_CALL_P (insn))
594 else if (GET_CODE (insn) == INSN)
596 set = PATTERN (insn);
597 if (GET_CODE (set) == PARALLEL)
598 set = XVECEXP (set, 0, 0);
599 if ((GET_CODE (set) == ASM_OPERANDS && MEM_VOLATILE_P (set))
600 || GET_CODE (set) == ASM_INPUT)
605 if (need_exit_edge && !have_exit_edge)
608 fprintf (rtl_dump_file, "Adding fake exit edge to bb %i\n",
610 make_edge (NULL, bb, EXIT_BLOCK_PTR, EDGE_FAKE);
612 if (need_entry_edge && !have_entry_edge)
615 fprintf (rtl_dump_file, "Adding fake entry edge to bb %i\n",
617 make_edge (NULL, ENTRY_BLOCK_PTR, bb, EDGE_FAKE);
621 el = create_edge_list ();
622 num_edges = NUM_EDGES (el);
623 edge_infos = (struct edge_info *)
624 xcalloc (num_edges, sizeof (struct edge_info));
626 for (i = 0 ; i < num_edges ; i++)
628 edge e = INDEX_EDGE (el, i);
630 e->aux = &edge_infos[i];
632 /* Mark edges we've replaced by fake edges above as ignored. */
633 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
634 && e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR)
635 EDGE_INFO (e)->ignore = 1;
638 total_num_blocks += n_basic_blocks + 2;
640 fprintf (rtl_dump_file, "%d basic blocks\n", n_basic_blocks);
642 total_num_edges += num_edges;
644 fprintf (rtl_dump_file, "%d edges\n", num_edges);
646 #ifdef ENABLE_CHECKING
650 /* Output line number information about each basic block for
652 if (flag_test_coverage)
655 for (i = 0 ; i < n_basic_blocks; i++)
657 basic_block bb = BASIC_BLOCK (i);
659 static int ignore_next_note = 0;
661 /* We are looking for line number notes. Search backward before
662 basic block to find correct ones. */
663 insn = prev_nonnote_insn (insn);
667 insn = NEXT_INSN (insn);
669 /* Output a zero to the .bb file to indicate that a new
670 block list is starting. */
671 __write_long (0, bb_file, 4);
673 while (insn != bb->end)
675 if (GET_CODE (insn) == NOTE)
677 /* Must ignore the line number notes that immediately
678 follow the end of an inline function to avoid counting
679 it twice. There is a note before the call, and one
681 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_REPEATED_LINE_NUMBER)
682 ignore_next_note = 1;
683 else if (NOTE_LINE_NUMBER (insn) > 0)
685 if (ignore_next_note)
686 ignore_next_note = 0;
689 /* If this is a new source file, then output the
690 file's name to the .bb file. */
691 if (! last_bb_file_name
692 || strcmp (NOTE_SOURCE_FILE (insn),
695 if (last_bb_file_name)
696 free (last_bb_file_name);
698 = xstrdup (NOTE_SOURCE_FILE (insn));
699 output_gcov_string (NOTE_SOURCE_FILE (insn),
702 /* Output the line number to the .bb file. Must be
703 done after the output_bb_profile_data() call, and
704 after the file name is written, to ensure that it
705 is correctly handled by gcov. */
706 __write_long (NOTE_LINE_NUMBER (insn), bb_file, 4);
710 insn = NEXT_INSN (insn);
713 __write_long (0, bb_file, 4);
716 /* Create spanning tree from basic block graph, mark each edge that is
717 on the spanning tree. We insert as many abnormal and critical edges
718 as possible to minimize number of edge splits necesary. */
720 find_spanning_tree (el);
722 /* Create a .bbg file from which gcov can reconstruct the basic block
723 graph. First output the number of basic blocks, and then for every
724 edge output the source and target basic block numbers.
725 NOTE: The format of this file must be compatible with gcov. */
727 if (flag_test_coverage)
731 /* The plus 2 stands for entry and exit block. */
732 __write_long (n_basic_blocks + 2, bbg_file, 4);
733 __write_long (num_edges + 1, bbg_file, 4);
735 for (i = 0; i < n_basic_blocks + 1; i++)
737 basic_block bb = GCOV_INDEX_TO_BB (i);
741 for (e = bb->succ; e; e = e->succ_next)
742 if (!EDGE_INFO (e)->ignore)
744 __write_long (count, bbg_file, 4);
746 for (e = bb->succ; e; e = e->succ_next)
748 struct edge_info *i = EDGE_INFO (e);
754 if (e->flags & EDGE_ABNORMAL)
756 if (e->flags & EDGE_FALLTHRU)
759 __write_long (BB_TO_GCOV_INDEX (e->dest), bbg_file, 4);
760 __write_long (flag_bits, bbg_file, 4);
764 /* Emit fake loopback edge for EXIT block to maitain compatibility with
766 __write_long (1, bbg_file, 4);
767 __write_long (0, bbg_file, 4);
768 __write_long (0x1, bbg_file, 4);
770 /* Emit a -1 to separate the list of all edges from the list of
771 loop back edges that follows. */
772 __write_long (-1, bbg_file, 4);
775 if (flag_branch_probabilities)
776 compute_branch_probabilities ();
778 /* For each edge not on the spanning tree, add counting code as rtl. */
780 if (profile_arc_flag)
782 instrument_edges (el);
783 allocate_reg_info (max_reg_num (), FALSE, FALSE);
786 remove_fake_edges ();
791 /* Union find algorithm implementation for the basic blocks using
798 basic_block group = bb, bb1;
800 while ((basic_block) group->aux != group)
801 group = (basic_block) group->aux;
804 while ((basic_block) bb->aux != group)
806 bb1 = (basic_block) bb->aux;
807 bb->aux = (void *) group;
814 union_groups (bb1, bb2)
815 basic_block bb1, bb2;
817 basic_block bb1g = find_group (bb1);
818 basic_block bb2g = find_group (bb2);
820 /* ??? I don't have a place for the rank field. OK. Lets go w/o it,
821 this code is unlikely going to be performance problem anyway. */
828 /* This function searches all of the edges in the program flow graph, and puts
829 as many bad edges as possible onto the spanning tree. Bad edges include
830 abnormals edges, which can't be instrumented at the moment. Since it is
831 possible for fake edges to form an cycle, we will have to develop some
832 better way in the future. Also put critical edges to the tree, since they
833 are more expensive to instrument. */
836 find_spanning_tree (el)
837 struct edge_list *el;
840 int num_edges = NUM_EDGES (el);
842 /* We use aux field for standard union-find algorithm. */
843 EXIT_BLOCK_PTR->aux = EXIT_BLOCK_PTR;
844 ENTRY_BLOCK_PTR->aux = ENTRY_BLOCK_PTR;
845 for (i = 0; i < n_basic_blocks; i++)
846 BASIC_BLOCK (i)->aux = BASIC_BLOCK (i);
848 /* Add fake edge exit to entry we can't instrument. */
849 union_groups (EXIT_BLOCK_PTR, ENTRY_BLOCK_PTR);
851 /* First add all abnormal edges to the tree unless they form an cycle. */
852 for (i = 0; i < num_edges; i++)
854 edge e = INDEX_EDGE (el, i);
855 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_FAKE))
856 && !EDGE_INFO (e)->ignore
857 && (find_group (e->src) != find_group (e->dest)))
859 EDGE_INFO (e)->on_tree = 1;
860 union_groups (e->src, e->dest);
864 /* Now insert all critical edges to the tree unless they form an cycle. */
865 for (i = 0; i < num_edges; i++)
867 edge e = INDEX_EDGE (el, i);
868 if ((e->flags & EDGE_CRITICAL)
869 && !EDGE_INFO (e)->ignore
870 && (find_group (e->src) != find_group (e->dest)))
872 EDGE_INFO (e)->on_tree = 1;
873 union_groups (e->src, e->dest);
877 /* And now the rest. */
878 for (i = 0; i < num_edges; i++)
880 edge e = INDEX_EDGE (el, i);
881 if (find_group (e->src) != find_group (e->dest)
882 && !EDGE_INFO (e)->ignore)
884 EDGE_INFO (e)->on_tree = 1;
885 union_groups (e->src, e->dest);
890 /* Perform file-level initialization for branch-prob processing. */
893 init_branch_prob (filename)
894 const char *filename;
899 if (flag_test_coverage)
901 int len = strlen (filename);
902 char *data_file, *bbg_file_name;
904 /* Open an output file for the basic block/line number map. */
905 data_file = (char *) alloca (len + 4);
906 strcpy (data_file, filename);
907 strip_off_ending (data_file, len);
908 strcat (data_file, ".bb");
909 if ((bb_file = fopen (data_file, "wb")) == 0)
910 pfatal_with_name (data_file);
912 /* Open an output file for the program flow graph. */
913 bbg_file_name = (char *) alloca (len + 5);
914 strcpy (bbg_file_name, filename);
915 strip_off_ending (bbg_file_name, len);
916 strcat (bbg_file_name, ".bbg");
917 if ((bbg_file = fopen (bbg_file_name, "wb")) == 0)
918 pfatal_with_name (bbg_file_name);
920 /* Initialize to zero, to ensure that the first file name will be
921 written to the .bb file. */
922 last_bb_file_name = 0;
925 if (flag_branch_probabilities)
929 len = strlen (filename);
930 da_file_name = (char *) alloca (len + 4);
931 strcpy (da_file_name, filename);
932 strip_off_ending (da_file_name, len);
933 strcat (da_file_name, ".da");
934 if ((da_file = fopen (da_file_name, "rb")) == 0)
935 warning ("file %s not found, execution counts assumed to be zero.",
938 /* The first word in the .da file gives the number of instrumented
939 edges, which is not needed for our purposes. */
942 __read_long (&len, da_file, 8);
945 if (profile_arc_flag)
946 init_edge_profiler ();
948 total_num_blocks = 0;
950 total_num_edges_instrumented = 0;
951 total_num_blocks_created = 0;
952 total_num_passes = 0;
953 total_num_times_called = 0;
954 total_num_branches = 0;
955 total_num_never_executed = 0;
956 for (i = 0; i < 20; i++)
957 total_hist_br_prob[i] = 0;
960 /* Performs file-level cleanup after branch-prob processing
966 if (flag_test_coverage)
972 if (flag_branch_probabilities)
977 /* This seems slightly dangerous, as it presumes the EOF
978 flag will not be set until an attempt is made to read
979 past the end of the file. */
981 warning (".da file contents exhausted too early\n");
982 /* Should be at end of file now. */
983 if (__read_long (&temp, da_file, 8) == 0)
984 warning (".da file contents not exhausted\n");
991 fprintf (rtl_dump_file, "\n");
992 fprintf (rtl_dump_file, "Total number of blocks: %d\n",
994 fprintf (rtl_dump_file, "Total number of edges: %d\n", total_num_edges);
995 fprintf (rtl_dump_file, "Total number of instrumented edges: %d\n",
996 total_num_edges_instrumented);
997 fprintf (rtl_dump_file, "Total number of blocks created: %d\n",
998 total_num_blocks_created);
999 fprintf (rtl_dump_file, "Total number of graph solution passes: %d\n",
1001 if (total_num_times_called != 0)
1002 fprintf (rtl_dump_file, "Average number of graph solution passes: %d\n",
1003 (total_num_passes + (total_num_times_called >> 1))
1004 / total_num_times_called);
1005 fprintf (rtl_dump_file, "Total number of branches: %d\n",
1006 total_num_branches);
1007 fprintf (rtl_dump_file, "Total number of branches never executed: %d\n",
1008 total_num_never_executed);
1009 if (total_num_branches)
1013 for (i = 0; i < 10; i++)
1014 fprintf (rtl_dump_file, "%d%% branches in range %d-%d%%\n",
1015 (total_hist_br_prob[i] + total_hist_br_prob[19-i]) * 100
1016 / total_num_branches, 5*i, 5*i+5);
1021 /* The label used by the edge profiling code. */
1023 static rtx profiler_label;
1025 /* Initialize the profiler_label. */
1028 init_edge_profiler ()
1030 /* Generate and save a copy of this so it can be shared. */
1031 char *name = ggc_alloc_string (NULL, 20);
1032 ASM_GENERATE_INTERNAL_LABEL (name, "LPBX", 2);
1033 profiler_label = gen_rtx_SYMBOL_REF (Pmode, name);
1034 ggc_add_rtx_root (&profiler_label, 1);
1037 /* Output instructions as RTL to increment the edge execution count. */
1040 gen_edge_profiler (edgeno)
1043 enum machine_mode mode = mode_for_size (LONG_TYPE_SIZE, MODE_INT, 0);
1049 tmp = force_reg (Pmode, profiler_label);
1050 tmp = plus_constant (tmp, LONG_TYPE_SIZE / BITS_PER_UNIT * edgeno);
1051 mem_ref = validize_mem (gen_rtx_MEM (mode, tmp));
1053 tmp = expand_binop (mode, add_optab, mem_ref, const1_rtx,
1054 mem_ref, 0, OPTAB_WIDEN);
1057 emit_move_insn (copy_rtx (mem_ref), tmp);
1059 sequence = gen_sequence ();
1064 /* Output code for a constructor that will invoke __bb_init_func, if
1065 this has not already been done. */
1068 output_func_start_profiler ()
1070 tree fnname, fndecl;
1071 char *name, *cfnname;
1073 enum machine_mode mode = mode_for_size (LONG_TYPE_SIZE, MODE_INT, 0);
1074 int save_flag_inline_functions = flag_inline_functions;
1075 int save_flag_test_coverage = flag_test_coverage;
1076 int save_profile_arc_flag = profile_arc_flag;
1077 int save_flag_branch_probabilities = flag_branch_probabilities;
1079 /* It's either already been output, or we don't need it because we're
1080 not doing profile-edges. */
1081 if (! need_func_profiler)
1084 need_func_profiler = 0;
1086 /* Synthesize a constructor function to invoke __bb_init_func with a
1087 pointer to this object file's profile block. */
1089 /* Try and make a unique name given the "file function name".
1091 And no, I don't like this either. */
1093 fnname = get_file_function_name ('I');
1094 cfnname = IDENTIFIER_POINTER (fnname);
1095 name = xmalloc (strlen (cfnname) + 5);
1096 sprintf (name, "%sGCOV",cfnname);
1097 fnname = get_identifier (name);
1100 fndecl = build_decl (FUNCTION_DECL, fnname,
1101 build_function_type (void_type_node, NULL_TREE));
1102 DECL_EXTERNAL (fndecl) = 0;
1104 #if defined(ASM_OUTPUT_CONSTRUCTOR) && defined(ASM_OUTPUT_DESTRUCTOR)
1105 /* It can be a static function as long as collect2 does not have
1106 to scan the object file to find its ctor/dtor routine. */
1107 TREE_PUBLIC (fndecl) = 0;
1109 TREE_PUBLIC (fndecl) = 1;
1112 DECL_ASSEMBLER_NAME (fndecl) = fnname;
1113 DECL_RESULT (fndecl) = build_decl (RESULT_DECL, NULL_TREE, void_type_node);
1115 fndecl = pushdecl (fndecl);
1116 rest_of_decl_compilation (fndecl, 0, 1, 0);
1117 announce_function (fndecl);
1118 current_function_decl = fndecl;
1119 DECL_INITIAL (fndecl) = error_mark_node;
1120 temporary_allocation ();
1121 make_function_rtl (fndecl);
1122 init_function_start (fndecl, input_filename, lineno);
1124 expand_function_start (fndecl, 0);
1126 /* Actually generate the code to call __bb_init_func. */
1127 name = ggc_alloc_string (NULL, 20);
1128 ASM_GENERATE_INTERNAL_LABEL (name, "LPBX", 0);
1129 table_address = force_reg (Pmode, gen_rtx_SYMBOL_REF (Pmode, name));
1130 emit_library_call (gen_rtx_SYMBOL_REF
1131 (Pmode, ggc_alloc_string ("__bb_init_func", 14)), 0,
1132 mode, 1, table_address, Pmode);
1134 expand_function_end (input_filename, lineno, 0);
1137 /* Since fndecl isn't in the list of globals, it would never be emitted
1138 when it's considered to be 'safe' for inlining, so turn off
1139 flag_inline_functions. */
1140 flag_inline_functions = 0;
1142 /* Don't instrument the function that turns on instrumentation. Which
1143 is also handy since we'd get silly warnings about not consuming all
1144 of our da_file input. */
1145 flag_test_coverage = 0;
1146 profile_arc_flag = 0;
1147 flag_branch_probabilities = 0;
1149 rest_of_compilation (fndecl);
1151 /* Reset flag_inline_functions to its original value. */
1152 flag_inline_functions = save_flag_inline_functions;
1153 flag_test_coverage = save_flag_test_coverage;
1154 profile_arc_flag = save_profile_arc_flag;
1155 flag_branch_probabilities = save_flag_branch_probabilities;
1158 fflush (asm_out_file);
1159 current_function_decl = NULL_TREE;
1161 assemble_constructor (IDENTIFIER_POINTER (DECL_NAME (fndecl)));