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;
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);
428 for (e = bb->succ; e; e = e->succ_next)
430 if (any_condjump_p (e->src->end)
431 && !EDGE_INFO (e)->ignore
432 && !(e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_FAKE)))
435 /* This calculates the branch probability as an integer between
436 0 and REG_BR_PROB_BASE, properly rounded to the nearest
437 integer. Perform the arithmetic in double to avoid
438 overflowing the range of ints. */
443 prob = (((double)e->count * REG_BR_PROB_BASE)
444 + (total >> 1)) / total;
445 if (prob < 0 || prob > REG_BR_PROB_BASE)
448 fprintf (rtl_dump_file, "bad count: prob for %d-%d thought to be %d (forcibly normalized)\n",
449 e->src->index, e->dest->index, prob);
452 prob = REG_BR_PROB_BASE / 2;
455 /* Match up probability with JUMP pattern. */
456 if (e->flags & EDGE_FALLTHRU)
457 prob = REG_BR_PROB_BASE - prob;
461 num_never_executed++;
464 int index = prob * 20 / REG_BR_PROB_BASE;
467 hist_br_prob[index]++;
471 note = find_reg_note (e->src->end, REG_BR_PROB, 0);
472 /* There may be already note put by some other pass, such
473 as builtin_expect expander. */
475 XEXP (note, 0) = GEN_INT (prob);
477 REG_NOTES (e->src->end)
478 = gen_rtx_EXPR_LIST (REG_BR_PROB, GEN_INT (prob),
479 REG_NOTES (e->src->end));
483 /* Add a REG_EXEC_COUNT note to the first instruction of this block. */
484 insn = next_nonnote_insn (bb->head);
486 if (GET_CODE (bb->head) == CODE_LABEL)
487 insn = next_nonnote_insn (insn);
489 /* Avoid crash on empty basic blocks. */
490 if (insn && INSN_P (insn))
492 = gen_rtx_EXPR_LIST (REG_EXEC_COUNT, GEN_INT (total),
496 /* This should never happen. */
498 warning ("Arc profiling: some edge counts were bad.");
502 fprintf (rtl_dump_file, "%d branches\n", num_branches);
503 fprintf (rtl_dump_file, "%d branches never executed\n",
506 for (i = 0; i < 10; i++)
507 fprintf (rtl_dump_file, "%d%% branches in range %d-%d%%\n",
508 (hist_br_prob[i] + hist_br_prob[19-i]) * 100 / num_branches,
511 total_num_branches += num_branches;
512 total_num_never_executed += num_never_executed;
513 for (i = 0; i < 20; i++)
514 total_hist_br_prob[i] += hist_br_prob[i];
516 fputc ('\n', rtl_dump_file);
517 fputc ('\n', rtl_dump_file);
523 /* Instrument and/or analyze program behavior based on program flow graph.
524 In either case, this function builds a flow graph for the function being
525 compiled. The flow graph is stored in BB_GRAPH.
527 When FLAG_PROFILE_ARCS is nonzero, this function instruments the edges in
528 the flow graph that are needed to reconstruct the dynamic behavior of the
531 When FLAG_BRANCH_PROBABILITIES is nonzero, this function reads auxiliary
532 information from a data file containing edge count information from previous
533 executions of the function being compiled. In this case, the flow graph is
534 annotated with actual execution counts, which are later propagated into the
535 rtl for optimization purposes.
537 Main entry point of this file. */
543 int num_edges, ignored_edges;
544 struct edge_info *edge_infos;
545 struct edge_list *el;
547 /* Start of a function. */
548 if (flag_test_coverage)
549 output_gcov_string (current_function_name, (long) -2);
551 total_num_times_called++;
553 /* We can't handle cyclic regions constructed using abnormal edges.
554 To avoid these we replace every source of abnormal edge by a fake
555 edge from entry node and every destination by fake edge to exit.
556 This keeps graph acyclic and our calculation exact for all normal
557 edges except for exit and entrance ones.
559 We also add fake exit edges for each call and asm statement in the
560 basic, since it may not return. */
562 for (i = 0; i < n_basic_blocks ; i++)
565 int need_exit_edge = 0, need_entry_edge = 0;
566 int have_exit_edge = 0, have_entry_edge = 0;
567 basic_block bb = BASIC_BLOCK (i);
570 for (e = bb->succ; e; e = e->succ_next)
572 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
573 && e->dest != EXIT_BLOCK_PTR)
575 if (e->dest == EXIT_BLOCK_PTR)
578 for (e = bb->pred; e; e = e->pred_next)
580 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
581 && e->src != ENTRY_BLOCK_PTR)
583 if (e->src == ENTRY_BLOCK_PTR)
587 /* ??? Not strictly needed unless flag_test_coverage, but adding
588 them anyway keeps the .da file consistent. */
589 /* ??? Currently inexact for basic blocks with multiple calls.
590 We need to split blocks here. */
591 for (insn = bb->head;
592 insn != NEXT_INSN (bb->end);
593 insn = NEXT_INSN (insn))
596 if (GET_CODE (insn) == CALL_INSN && !CONST_CALL_P (insn))
598 else if (GET_CODE (insn) == INSN)
600 set = PATTERN (insn);
601 if (GET_CODE (set) == PARALLEL)
602 set = XVECEXP (set, 0, 0);
603 if ((GET_CODE (set) == ASM_OPERANDS && MEM_VOLATILE_P (set))
604 || GET_CODE (set) == ASM_INPUT)
609 if (need_exit_edge && !have_exit_edge)
612 fprintf (rtl_dump_file, "Adding fake exit edge to bb %i\n",
614 make_edge (NULL, bb, EXIT_BLOCK_PTR, EDGE_FAKE);
616 if (need_entry_edge && !have_entry_edge)
619 fprintf (rtl_dump_file, "Adding fake entry edge to bb %i\n",
621 make_edge (NULL, ENTRY_BLOCK_PTR, bb, EDGE_FAKE);
625 el = create_edge_list ();
626 num_edges = NUM_EDGES (el);
627 edge_infos = (struct edge_info *)
628 xcalloc (num_edges, sizeof (struct edge_info));
631 for (i = 0 ; i < num_edges ; i++)
633 edge e = INDEX_EDGE (el, i);
635 e->aux = &edge_infos[i];
637 /* Mark edges we've replaced by fake edges above as ignored. */
638 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
639 && e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR)
641 EDGE_INFO (e)->ignore = 1;
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 /* Fake edges that are not on the tree will not be instrumented, so
723 mark them ignored. */
724 for (i = 0; i < num_edges; i++)
726 edge e = INDEX_EDGE (el, i);
727 struct edge_info *inf = EDGE_INFO (e);
728 if ((e->flags & EDGE_FAKE) && !inf->ignore && !inf->on_tree)
735 total_num_blocks += n_basic_blocks + 2;
737 fprintf (rtl_dump_file, "%d basic blocks\n", n_basic_blocks);
739 total_num_edges += num_edges;
741 fprintf (rtl_dump_file, "%d edges\n", num_edges);
743 total_num_edges_ignored += ignored_edges;
745 fprintf (rtl_dump_file, "%d ignored edges\n", ignored_edges);
747 /* Create a .bbg file from which gcov can reconstruct the basic block
748 graph. First output the number of basic blocks, and then for every
749 edge output the source and target basic block numbers.
750 NOTE: The format of this file must be compatible with gcov. */
752 if (flag_test_coverage)
756 /* The plus 2 stands for entry and exit block. */
757 __write_long (n_basic_blocks + 2, bbg_file, 4);
758 __write_long (num_edges - ignored_edges + 1, bbg_file, 4);
760 for (i = 0; i < n_basic_blocks + 1; i++)
762 basic_block bb = GCOV_INDEX_TO_BB (i);
766 for (e = bb->succ; e; e = e->succ_next)
767 if (!EDGE_INFO (e)->ignore)
769 __write_long (count, bbg_file, 4);
771 for (e = bb->succ; e; e = e->succ_next)
773 struct edge_info *i = EDGE_INFO (e);
779 if (e->flags & EDGE_FAKE)
781 if (e->flags & EDGE_FALLTHRU)
784 __write_long (BB_TO_GCOV_INDEX (e->dest), bbg_file, 4);
785 __write_long (flag_bits, bbg_file, 4);
789 /* Emit fake loopback edge for EXIT block to maitain compatibility with
791 __write_long (1, bbg_file, 4);
792 __write_long (0, bbg_file, 4);
793 __write_long (0x1, bbg_file, 4);
795 /* Emit a -1 to separate the list of all edges from the list of
796 loop back edges that follows. */
797 __write_long (-1, bbg_file, 4);
800 if (flag_branch_probabilities)
801 compute_branch_probabilities ();
803 /* For each edge not on the spanning tree, add counting code as rtl. */
805 if (profile_arc_flag)
807 instrument_edges (el);
808 allocate_reg_info (max_reg_num (), FALSE, FALSE);
811 remove_fake_edges ();
816 /* Union find algorithm implementation for the basic blocks using
823 basic_block group = bb, bb1;
825 while ((basic_block) group->aux != group)
826 group = (basic_block) group->aux;
829 while ((basic_block) bb->aux != group)
831 bb1 = (basic_block) bb->aux;
832 bb->aux = (void *) group;
839 union_groups (bb1, bb2)
840 basic_block bb1, bb2;
842 basic_block bb1g = find_group (bb1);
843 basic_block bb2g = find_group (bb2);
845 /* ??? I don't have a place for the rank field. OK. Lets go w/o it,
846 this code is unlikely going to be performance problem anyway. */
853 /* This function searches all of the edges in the program flow graph, and puts
854 as many bad edges as possible onto the spanning tree. Bad edges include
855 abnormals edges, which can't be instrumented at the moment. Since it is
856 possible for fake edges to form an cycle, we will have to develop some
857 better way in the future. Also put critical edges to the tree, since they
858 are more expensive to instrument. */
861 find_spanning_tree (el)
862 struct edge_list *el;
865 int num_edges = NUM_EDGES (el);
867 /* We use aux field for standard union-find algorithm. */
868 EXIT_BLOCK_PTR->aux = EXIT_BLOCK_PTR;
869 ENTRY_BLOCK_PTR->aux = ENTRY_BLOCK_PTR;
870 for (i = 0; i < n_basic_blocks; i++)
871 BASIC_BLOCK (i)->aux = BASIC_BLOCK (i);
873 /* Add fake edge exit to entry we can't instrument. */
874 union_groups (EXIT_BLOCK_PTR, ENTRY_BLOCK_PTR);
876 /* First add all abnormal edges to the tree unless they form an cycle. */
877 for (i = 0; i < num_edges; i++)
879 edge e = INDEX_EDGE (el, i);
880 if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_FAKE))
881 && !EDGE_INFO (e)->ignore
882 && (find_group (e->src) != find_group (e->dest)))
884 EDGE_INFO (e)->on_tree = 1;
885 union_groups (e->src, e->dest);
889 /* Now insert all critical edges to the tree unless they form an cycle. */
890 for (i = 0; i < num_edges; i++)
892 edge e = INDEX_EDGE (el, i);
893 if ((e->flags & EDGE_CRITICAL)
894 && !EDGE_INFO (e)->ignore
895 && (find_group (e->src) != find_group (e->dest)))
897 EDGE_INFO (e)->on_tree = 1;
898 union_groups (e->src, e->dest);
902 /* And now the rest. */
903 for (i = 0; i < num_edges; i++)
905 edge e = INDEX_EDGE (el, i);
906 if (find_group (e->src) != find_group (e->dest)
907 && !EDGE_INFO (e)->ignore)
909 EDGE_INFO (e)->on_tree = 1;
910 union_groups (e->src, e->dest);
915 /* Perform file-level initialization for branch-prob processing. */
918 init_branch_prob (filename)
919 const char *filename;
924 if (flag_test_coverage)
926 int len = strlen (filename);
927 char *data_file, *bbg_file_name;
929 /* Open an output file for the basic block/line number map. */
930 data_file = (char *) alloca (len + 4);
931 strcpy (data_file, filename);
932 strip_off_ending (data_file, len);
933 strcat (data_file, ".bb");
934 if ((bb_file = fopen (data_file, "wb")) == 0)
935 fatal_io_error ("can't open %s", data_file);
937 /* Open an output file for the program flow graph. */
938 bbg_file_name = (char *) alloca (len + 5);
939 strcpy (bbg_file_name, filename);
940 strip_off_ending (bbg_file_name, len);
941 strcat (bbg_file_name, ".bbg");
942 if ((bbg_file = fopen (bbg_file_name, "wb")) == 0)
943 fatal_io_error ("can't open %s", bbg_file_name);
945 /* Initialize to zero, to ensure that the first file name will be
946 written to the .bb file. */
947 last_bb_file_name = 0;
950 if (flag_branch_probabilities)
954 len = strlen (filename);
955 da_file_name = (char *) alloca (len + 4);
956 strcpy (da_file_name, filename);
957 strip_off_ending (da_file_name, len);
958 strcat (da_file_name, ".da");
959 if ((da_file = fopen (da_file_name, "rb")) == 0)
960 warning ("file %s not found, execution counts assumed to be zero.",
963 /* The first word in the .da file gives the number of instrumented
964 edges, which is not needed for our purposes. */
967 __read_long (&len, da_file, 8);
970 if (profile_arc_flag)
971 init_edge_profiler ();
973 total_num_blocks = 0;
975 total_num_edges_ignored = 0;
976 total_num_edges_instrumented = 0;
977 total_num_blocks_created = 0;
978 total_num_passes = 0;
979 total_num_times_called = 0;
980 total_num_branches = 0;
981 total_num_never_executed = 0;
982 for (i = 0; i < 20; i++)
983 total_hist_br_prob[i] = 0;
986 /* Performs file-level cleanup after branch-prob processing
992 if (flag_test_coverage)
998 if (flag_branch_probabilities)
1003 /* This seems slightly dangerous, as it presumes the EOF
1004 flag will not be set until an attempt is made to read
1005 past the end of the file. */
1007 warning (".da file contents exhausted too early\n");
1008 /* Should be at end of file now. */
1009 if (__read_long (&temp, da_file, 8) == 0)
1010 warning (".da file contents not exhausted\n");
1017 fprintf (rtl_dump_file, "\n");
1018 fprintf (rtl_dump_file, "Total number of blocks: %d\n",
1020 fprintf (rtl_dump_file, "Total number of edges: %d\n", total_num_edges);
1021 fprintf (rtl_dump_file, "Total number of ignored edges: %d\n",
1022 total_num_edges_ignored);
1023 fprintf (rtl_dump_file, "Total number of instrumented edges: %d\n",
1024 total_num_edges_instrumented);
1025 fprintf (rtl_dump_file, "Total number of blocks created: %d\n",
1026 total_num_blocks_created);
1027 fprintf (rtl_dump_file, "Total number of graph solution passes: %d\n",
1029 if (total_num_times_called != 0)
1030 fprintf (rtl_dump_file, "Average number of graph solution passes: %d\n",
1031 (total_num_passes + (total_num_times_called >> 1))
1032 / total_num_times_called);
1033 fprintf (rtl_dump_file, "Total number of branches: %d\n",
1034 total_num_branches);
1035 fprintf (rtl_dump_file, "Total number of branches never executed: %d\n",
1036 total_num_never_executed);
1037 if (total_num_branches)
1041 for (i = 0; i < 10; i++)
1042 fprintf (rtl_dump_file, "%d%% branches in range %d-%d%%\n",
1043 (total_hist_br_prob[i] + total_hist_br_prob[19-i]) * 100
1044 / total_num_branches, 5*i, 5*i+5);
1049 /* The label used by the edge profiling code. */
1051 static rtx profiler_label;
1053 /* Initialize the profiler_label. */
1056 init_edge_profiler ()
1058 /* Generate and save a copy of this so it can be shared. */
1060 ASM_GENERATE_INTERNAL_LABEL (buf, "LPBX", 2);
1061 profiler_label = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (buf));
1062 ggc_add_rtx_root (&profiler_label, 1);
1065 /* Output instructions as RTL to increment the edge execution count. */
1068 gen_edge_profiler (edgeno)
1071 enum machine_mode mode = mode_for_size (GCOV_TYPE_SIZE, MODE_INT, 0);
1077 tmp = force_reg (Pmode, profiler_label);
1078 tmp = plus_constant (tmp, GCOV_TYPE_SIZE / BITS_PER_UNIT * edgeno);
1079 mem_ref = validize_mem (gen_rtx_MEM (mode, tmp));
1081 tmp = expand_binop (mode, add_optab, mem_ref, const1_rtx,
1082 mem_ref, 0, OPTAB_WIDEN);
1085 emit_move_insn (copy_rtx (mem_ref), tmp);
1087 sequence = gen_sequence ();
1092 /* Output code for a constructor that will invoke __bb_init_func, if
1093 this has not already been done. */
1096 output_func_start_profiler ()
1098 tree fnname, fndecl;
1101 const char *cfnname;
1103 enum machine_mode mode = mode_for_size (GCOV_TYPE_SIZE, MODE_INT, 0);
1104 int save_flag_inline_functions = flag_inline_functions;
1105 int save_flag_test_coverage = flag_test_coverage;
1106 int save_profile_arc_flag = profile_arc_flag;
1107 int save_flag_branch_probabilities = flag_branch_probabilities;
1109 /* It's either already been output, or we don't need it because we're
1110 not doing profile-edges. */
1111 if (! need_func_profiler)
1114 need_func_profiler = 0;
1116 /* Synthesize a constructor function to invoke __bb_init_func with a
1117 pointer to this object file's profile block. */
1119 /* Try and make a unique name given the "file function name".
1121 And no, I don't like this either. */
1123 fnname = get_file_function_name ('I');
1124 cfnname = IDENTIFIER_POINTER (fnname);
1125 name = concat (cfnname, "GCOV", NULL);
1126 fnname = get_identifier (name);
1129 fndecl = build_decl (FUNCTION_DECL, fnname,
1130 build_function_type (void_type_node, NULL_TREE));
1131 DECL_EXTERNAL (fndecl) = 0;
1133 #if defined(ASM_OUTPUT_CONSTRUCTOR) && defined(ASM_OUTPUT_DESTRUCTOR)
1134 /* It can be a static function as long as collect2 does not have
1135 to scan the object file to find its ctor/dtor routine. */
1136 TREE_PUBLIC (fndecl) = 0;
1138 TREE_PUBLIC (fndecl) = 1;
1141 DECL_RESULT (fndecl) = build_decl (RESULT_DECL, NULL_TREE, void_type_node);
1143 fndecl = pushdecl (fndecl);
1144 rest_of_decl_compilation (fndecl, 0, 1, 0);
1145 announce_function (fndecl);
1146 current_function_decl = fndecl;
1147 DECL_INITIAL (fndecl) = error_mark_node;
1148 make_decl_rtl (fndecl, NULL);
1149 init_function_start (fndecl, input_filename, lineno);
1151 expand_function_start (fndecl, 0);
1153 /* Actually generate the code to call __bb_init_func. */
1154 ASM_GENERATE_INTERNAL_LABEL (buf, "LPBX", 0);
1155 table_address = force_reg (Pmode,
1156 gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (buf)));
1157 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__bb_init_func"), 0,
1158 mode, 1, table_address, Pmode);
1160 expand_function_end (input_filename, lineno, 0);
1163 /* Since fndecl isn't in the list of globals, it would never be emitted
1164 when it's considered to be 'safe' for inlining, so turn off
1165 flag_inline_functions. */
1166 flag_inline_functions = 0;
1168 /* Don't instrument the function that turns on instrumentation. Which
1169 is also handy since we'd get silly warnings about not consuming all
1170 of our da_file input. */
1171 flag_test_coverage = 0;
1172 profile_arc_flag = 0;
1173 flag_branch_probabilities = 0;
1175 rest_of_compilation (fndecl);
1177 /* Reset flag_inline_functions to its original value. */
1178 flag_inline_functions = save_flag_inline_functions;
1179 flag_test_coverage = save_flag_test_coverage;
1180 profile_arc_flag = save_profile_arc_flag;
1181 flag_branch_probabilities = save_flag_branch_probabilities;
1184 fflush (asm_out_file);
1185 current_function_decl = NULL_TREE;
1187 assemble_constructor (IDENTIFIER_POINTER (DECL_NAME (fndecl)));