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_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 /* If non-zero, we need to output a constructor to set up the
122 per-object-file data. */
123 static int need_func_profiler
= 0;
125 /* Add edge instrumentation code to the entire insn chain.
127 F is the first insn of the chain.
128 NUM_BLOCKS is the number of basic blocks found in F. */
131 instrument_edges (el
)
132 struct edge_list
*el
;
135 int num_instr_edges
= 0;
136 int num_edges
= NUM_EDGES (el
);
137 remove_fake_edges ();
139 for (i
= 0; i
< n_basic_blocks
+ 2; i
++)
141 basic_block bb
= GCOV_INDEX_TO_BB (i
);
145 struct edge_info
*inf
= EDGE_INFO (e
);
146 if (!inf
->ignore
&& !inf
->on_tree
)
148 if (e
->flags
& EDGE_ABNORMAL
)
151 fprintf (rtl_dump_file
, "Edge %d to %d instrumented%s\n",
152 e
->src
->index
, e
->dest
->index
,
153 e
->flags
& EDGE_CRITICAL
? " (and split)" : "");
154 need_func_profiler
= 1;
155 insert_insn_on_edge (
156 gen_edge_profiler (total_num_edges_instrumented
157 + num_instr_edges
++), e
);
163 total_num_edges_instrumented
+= num_instr_edges
;
164 count_instrumented_edges
= total_num_edges_instrumented
;
166 total_num_blocks_created
+= num_edges
;
168 fprintf (rtl_dump_file
, "%d edges instrumented\n", num_instr_edges
);
170 commit_edge_insertions ();
173 /* Output STRING to bb_file, surrounded by DELIMITER. */
176 output_gcov_string (string
, delimiter
)
182 /* Write a delimiter to indicate that a file name follows. */
183 __write_long (delimiter
, bb_file
, 4);
185 /* Write the string. */
186 temp
= strlen (string
) + 1;
187 fwrite (string
, temp
, 1, bb_file
);
189 /* Append a few zeros, to align the output to a 4 byte boundary. */
195 c
[0] = c
[1] = c
[2] = c
[3] = 0;
196 fwrite (c
, sizeof (char), 4 - temp
, bb_file
);
199 /* Store another delimiter in the .bb file, just to make it easy to find
200 the end of the file name. */
201 __write_long (delimiter
, bb_file
, 4);
205 /* Compute the branch probabilities for the various branches.
206 Annotate them accordingly. */
209 compute_branch_probabilities ()
215 int hist_br_prob
[20];
216 int num_never_executed
;
219 struct bb_info
*bb_infos
;
221 /* Attach extra info block to each bb. */
223 bb_infos
= (struct bb_info
*)
224 xcalloc (n_basic_blocks
+ 2, sizeof (struct bb_info
));
225 for (i
= 0; i
< n_basic_blocks
+ 2; i
++)
227 basic_block bb
= GCOV_INDEX_TO_BB (i
);
230 bb
->aux
= &bb_infos
[i
];
231 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
232 if (!EDGE_INFO (e
)->ignore
)
233 BB_INFO (bb
)->succ_count
++;
234 for (e
= bb
->pred
; e
; e
= e
->pred_next
)
235 if (!EDGE_INFO (e
)->ignore
)
236 BB_INFO (bb
)->pred_count
++;
239 /* Avoid predicting entry on exit nodes. */
240 BB_INFO (EXIT_BLOCK_PTR
)->succ_count
= 2;
241 BB_INFO (ENTRY_BLOCK_PTR
)->pred_count
= 2;
243 /* For each edge not on the spanning tree, set its execution count from
246 /* The first count in the .da file is the number of times that the function
247 was entered. This is the exec_count for block zero. */
249 for (i
= 0; i
< n_basic_blocks
+ 2; i
++)
251 basic_block bb
= GCOV_INDEX_TO_BB (i
);
253 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
254 if (!EDGE_INFO (e
)->ignore
&& !EDGE_INFO (e
)->on_tree
)
260 __read_gcov_type (&value
, da_file
, 8);
265 EDGE_INFO (e
)->count_valid
= 1;
266 BB_INFO (bb
)->succ_count
--;
267 BB_INFO (e
->dest
)->pred_count
--;
270 fprintf (rtl_dump_file
, "\nRead edge from %i to %i, count:",
271 bb
->index
, e
->dest
->index
);
272 fprintf (rtl_dump_file
, HOST_WIDEST_INT_PRINT_DEC
,
273 (HOST_WIDEST_INT
) e
->count
);
279 fprintf (rtl_dump_file
, "\n%d edge counts read\n", num_edges
);
281 /* For every block in the file,
282 - if every exit/entrance edge has a known count, then set the block count
283 - if the block count is known, and every exit/entrance edge but one has
284 a known execution count, then set the count of the remaining edge
286 As edge counts are set, decrement the succ/pred count, but don't delete
287 the edge, that way we can easily tell when all edges are known, or only
288 one edge is unknown. */
290 /* The order that the basic blocks are iterated through is important.
291 Since the code that finds spanning trees starts with block 0, low numbered
292 edges are put on the spanning tree in preference to high numbered edges.
293 Hence, most instrumented edges are at the end. Graph solving works much
294 faster if we propagate numbers from the end to the start.
296 This takes an average of slightly more than 3 passes. */
304 for (i
= n_basic_blocks
+ 1; i
>= 0; i
--)
306 basic_block bb
= GCOV_INDEX_TO_BB (i
);
307 struct bb_info
*bi
= BB_INFO (bb
);
308 if (! bi
->count_valid
)
310 if (bi
->succ_count
== 0)
315 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
321 else if (bi
->pred_count
== 0)
326 for (e
= bb
->pred
; e
; e
= e
->pred_next
)
335 if (bi
->succ_count
== 1)
340 /* One of the counts will be invalid, but it is zero,
341 so adding it in also doesn't hurt. */
342 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
345 /* Seedgeh for the invalid edge, and set its count. */
346 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
347 if (! EDGE_INFO (e
)->count_valid
&& ! EDGE_INFO (e
)->ignore
)
350 /* Calculate count for remaining edge by conservation. */
351 total
= bb
->count
- total
;
355 EDGE_INFO (e
)->count_valid
= 1;
359 BB_INFO (e
->dest
)->pred_count
--;
362 if (bi
->pred_count
== 1)
367 /* One of the counts will be invalid, but it is zero,
368 so adding it in also doesn't hurt. */
369 for (e
= bb
->pred
; e
; e
= e
->pred_next
)
372 /* Seedgeh for the invalid edge, and set its count. */
373 for (e
= bb
->pred
; e
; e
= e
->pred_next
)
374 if (! EDGE_INFO (e
)->count_valid
&& ! EDGE_INFO (e
)->ignore
)
377 /* Calculate count for remaining edge by conservation. */
378 total
= bb
->count
- total
+ e
->count
;
382 EDGE_INFO (e
)->count_valid
= 1;
386 BB_INFO (e
->src
)->succ_count
--;
393 dump_flow_info (rtl_dump_file
);
395 total_num_passes
+= passes
;
397 fprintf (rtl_dump_file
, "Graph solving took %d passes.\n\n", passes
);
399 /* If the graph has been correctly solved, every block will have a
400 succ and pred count of zero. */
401 for (i
= 0; i
< n_basic_blocks
; i
++)
403 basic_block bb
= BASIC_BLOCK (i
);
404 if (BB_INFO (bb
)->succ_count
|| BB_INFO (bb
)->pred_count
)
408 /* For every edge, calculate its branch probability and add a reg_note
409 to the branch insn to indicate this. */
411 for (i
= 0; i
< 20; i
++)
413 num_never_executed
= 0;
416 for (i
= 0; i
< n_basic_blocks
; i
++)
418 basic_block bb
= BASIC_BLOCK (i
);
427 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
429 if (any_condjump_p (e
->src
->end
)
430 && !EDGE_INFO (e
)->ignore
431 && !(e
->flags
& (EDGE_ABNORMAL
| EDGE_ABNORMAL_CALL
| EDGE_FAKE
)))
434 /* This calculates the branch probability as an integer between
435 0 and REG_BR_PROB_BASE, properly rounded to the nearest
436 integer. Perform the arithmetic in double to avoid
437 overflowing the range of ints. */
442 prob
= (((double)e
->count
* REG_BR_PROB_BASE
)
443 + (total
>> 1)) / total
;
444 if (prob
< 0 || prob
> REG_BR_PROB_BASE
)
447 fprintf (rtl_dump_file
, "bad count: prob for %d-%d thought to be %d (forcibly normalized)\n",
448 e
->src
->index
, e
->dest
->index
, prob
);
451 prob
= REG_BR_PROB_BASE
/ 2;
454 /* Match up probability with JUMP pattern. */
455 if (e
->flags
& EDGE_FALLTHRU
)
456 prob
= REG_BR_PROB_BASE
- prob
;
460 num_never_executed
++;
463 int index
= prob
* 20 / REG_BR_PROB_BASE
;
466 hist_br_prob
[index
]++;
470 note
= find_reg_note (e
->src
->end
, REG_BR_PROB
, 0);
471 /* There may be already note put by some other pass, such
472 as builtin_expect expander. */
474 XEXP (note
, 0) = GEN_INT (prob
);
476 REG_NOTES (e
->src
->end
)
477 = gen_rtx_EXPR_LIST (REG_BR_PROB
, GEN_INT (prob
),
478 REG_NOTES (e
->src
->end
));
482 /* Add a REG_EXEC_COUNT note to the first instruction of this block. */
483 insn
= next_nonnote_insn (bb
->head
);
485 if (GET_CODE (bb
->head
) == CODE_LABEL
)
486 insn
= next_nonnote_insn (insn
);
488 /* Avoid crash on empty basic blocks. */
489 if (insn
&& INSN_P (insn
))
491 = gen_rtx_EXPR_LIST (REG_EXEC_COUNT
, GEN_INT (total
),
495 /* This should never happen. */
497 warning ("Arc profiling: some edge counts were bad.");
501 fprintf (rtl_dump_file
, "%d branches\n", num_branches
);
502 fprintf (rtl_dump_file
, "%d branches never executed\n",
505 for (i
= 0; i
< 10; i
++)
506 fprintf (rtl_dump_file
, "%d%% branches in range %d-%d%%\n",
507 (hist_br_prob
[i
] + hist_br_prob
[19-i
]) * 100 / num_branches
,
510 total_num_branches
+= num_branches
;
511 total_num_never_executed
+= num_never_executed
;
512 for (i
= 0; i
< 20; i
++)
513 total_hist_br_prob
[i
] += hist_br_prob
[i
];
515 fputc ('\n', rtl_dump_file
);
516 fputc ('\n', rtl_dump_file
);
522 /* Instrument and/or analyze program behavior based on program flow graph.
523 In either case, this function builds a flow graph for the function being
524 compiled. The flow graph is stored in BB_GRAPH.
526 When FLAG_PROFILE_ARCS is nonzero, this function instruments the edges in
527 the flow graph that are needed to reconstruct the dynamic behavior of the
530 When FLAG_BRANCH_PROBABILITIES is nonzero, this function reads auxiliary
531 information from a data file containing edge count information from previous
532 executions of the function being compiled. In this case, the flow graph is
533 annotated with actual execution counts, which are later propagated into the
534 rtl for optimization purposes.
536 Main entry point of this file. */
543 struct edge_info
*edge_infos
;
544 struct edge_list
*el
;
546 /* Start of a function. */
547 if (flag_test_coverage
)
548 output_gcov_string (current_function_name
, (long) -2);
550 total_num_times_called
++;
552 /* We can't handle cyclic regions constructed using abnormal edges.
553 To avoid these we replace every source of abnormal edge by a fake
554 edge from entry node and every destination by fake edge to exit.
555 This keeps graph acyclic and our calculation exact for all normal
556 edges except for exit and entrance ones.
558 We also add fake exit edges for each call and asm statement in the
559 basic, since it may not return. */
561 for (i
= 0; i
< n_basic_blocks
; i
++)
564 int need_exit_edge
= 0, need_entry_edge
= 0;
565 int have_exit_edge
= 0, have_entry_edge
= 0;
566 basic_block bb
= BASIC_BLOCK (i
);
569 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
571 if ((e
->flags
& (EDGE_ABNORMAL
| EDGE_ABNORMAL_CALL
))
572 && e
->dest
!= EXIT_BLOCK_PTR
)
574 if (e
->dest
== EXIT_BLOCK_PTR
)
577 for (e
= bb
->pred
; e
; e
= e
->pred_next
)
579 if ((e
->flags
& (EDGE_ABNORMAL
| EDGE_ABNORMAL_CALL
))
580 && e
->src
!= ENTRY_BLOCK_PTR
)
582 if (e
->src
== ENTRY_BLOCK_PTR
)
586 /* ??? Not strictly needed unless flag_test_coverage, but adding
587 them anyway keeps the .da file consistent. */
588 /* ??? Currently inexact for basic blocks with multiple calls.
589 We need to split blocks here. */
590 for (insn
= bb
->head
;
591 insn
!= NEXT_INSN (bb
->end
);
592 insn
= NEXT_INSN (insn
))
595 if (GET_CODE (insn
) == CALL_INSN
&& !CONST_CALL_P (insn
))
597 else if (GET_CODE (insn
) == INSN
)
599 set
= PATTERN (insn
);
600 if (GET_CODE (set
) == PARALLEL
)
601 set
= XVECEXP (set
, 0, 0);
602 if ((GET_CODE (set
) == ASM_OPERANDS
&& MEM_VOLATILE_P (set
))
603 || GET_CODE (set
) == ASM_INPUT
)
608 if (need_exit_edge
&& !have_exit_edge
)
611 fprintf (rtl_dump_file
, "Adding fake exit edge to bb %i\n",
613 make_edge (NULL
, bb
, EXIT_BLOCK_PTR
, EDGE_FAKE
);
615 if (need_entry_edge
&& !have_entry_edge
)
618 fprintf (rtl_dump_file
, "Adding fake entry edge to bb %i\n",
620 make_edge (NULL
, ENTRY_BLOCK_PTR
, bb
, EDGE_FAKE
);
624 el
= create_edge_list ();
625 num_edges
= NUM_EDGES (el
);
626 edge_infos
= (struct edge_info
*)
627 xcalloc (num_edges
, sizeof (struct edge_info
));
629 for (i
= 0 ; i
< num_edges
; i
++)
631 edge e
= INDEX_EDGE (el
, i
);
633 e
->aux
= &edge_infos
[i
];
635 /* Mark edges we've replaced by fake edges above as ignored. */
636 if ((e
->flags
& (EDGE_ABNORMAL
| EDGE_ABNORMAL_CALL
))
637 && e
->src
!= ENTRY_BLOCK_PTR
&& e
->dest
!= EXIT_BLOCK_PTR
)
638 EDGE_INFO (e
)->ignore
= 1;
641 total_num_blocks
+= n_basic_blocks
+ 2;
643 fprintf (rtl_dump_file
, "%d basic blocks\n", n_basic_blocks
);
645 total_num_edges
+= num_edges
;
647 fprintf (rtl_dump_file
, "%d edges\n", num_edges
);
649 #ifdef ENABLE_CHECKING
653 /* Output line number information about each basic block for
655 if (flag_test_coverage
)
658 for (i
= 0 ; i
< n_basic_blocks
; i
++)
660 basic_block bb
= BASIC_BLOCK (i
);
662 static int ignore_next_note
= 0;
664 /* We are looking for line number notes. Search backward before
665 basic block to find correct ones. */
666 insn
= prev_nonnote_insn (insn
);
670 insn
= NEXT_INSN (insn
);
672 /* Output a zero to the .bb file to indicate that a new
673 block list is starting. */
674 __write_long (0, bb_file
, 4);
676 while (insn
!= bb
->end
)
678 if (GET_CODE (insn
) == NOTE
)
680 /* Must ignore the line number notes that immediately
681 follow the end of an inline function to avoid counting
682 it twice. There is a note before the call, and one
684 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_REPEATED_LINE_NUMBER
)
685 ignore_next_note
= 1;
686 else if (NOTE_LINE_NUMBER (insn
) > 0)
688 if (ignore_next_note
)
689 ignore_next_note
= 0;
692 /* If this is a new source file, then output the
693 file's name to the .bb file. */
694 if (! last_bb_file_name
695 || strcmp (NOTE_SOURCE_FILE (insn
),
698 if (last_bb_file_name
)
699 free (last_bb_file_name
);
701 = xstrdup (NOTE_SOURCE_FILE (insn
));
702 output_gcov_string (NOTE_SOURCE_FILE (insn
),
705 /* Output the line number to the .bb file. Must be
706 done after the output_bb_profile_data() call, and
707 after the file name is written, to ensure that it
708 is correctly handled by gcov. */
709 __write_long (NOTE_LINE_NUMBER (insn
), bb_file
, 4);
713 insn
= NEXT_INSN (insn
);
716 __write_long (0, bb_file
, 4);
719 /* Create spanning tree from basic block graph, mark each edge that is
720 on the spanning tree. We insert as many abnormal and critical edges
721 as possible to minimize number of edge splits necesary. */
723 find_spanning_tree (el
);
725 /* Create a .bbg file from which gcov can reconstruct the basic block
726 graph. First output the number of basic blocks, and then for every
727 edge output the source and target basic block numbers.
728 NOTE: The format of this file must be compatible with gcov. */
730 if (flag_test_coverage
)
734 /* The plus 2 stands for entry and exit block. */
735 __write_long (n_basic_blocks
+ 2, bbg_file
, 4);
736 __write_long (num_edges
+ 1, bbg_file
, 4);
738 for (i
= 0; i
< n_basic_blocks
+ 1; i
++)
740 basic_block bb
= GCOV_INDEX_TO_BB (i
);
744 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
745 if (!EDGE_INFO (e
)->ignore
)
747 __write_long (count
, bbg_file
, 4);
749 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
751 struct edge_info
*i
= EDGE_INFO (e
);
757 if (e
->flags
& EDGE_ABNORMAL
)
759 if (e
->flags
& EDGE_FALLTHRU
)
762 __write_long (BB_TO_GCOV_INDEX (e
->dest
), bbg_file
, 4);
763 __write_long (flag_bits
, bbg_file
, 4);
767 /* Emit fake loopback edge for EXIT block to maitain compatibility with
769 __write_long (1, bbg_file
, 4);
770 __write_long (0, bbg_file
, 4);
771 __write_long (0x1, bbg_file
, 4);
773 /* Emit a -1 to separate the list of all edges from the list of
774 loop back edges that follows. */
775 __write_long (-1, bbg_file
, 4);
778 if (flag_branch_probabilities
)
779 compute_branch_probabilities ();
781 /* For each edge not on the spanning tree, add counting code as rtl. */
783 if (profile_arc_flag
)
785 instrument_edges (el
);
786 allocate_reg_info (max_reg_num (), FALSE
, FALSE
);
789 remove_fake_edges ();
794 /* Union find algorithm implementation for the basic blocks using
801 basic_block group
= bb
, bb1
;
803 while ((basic_block
) group
->aux
!= group
)
804 group
= (basic_block
) group
->aux
;
807 while ((basic_block
) bb
->aux
!= group
)
809 bb1
= (basic_block
) bb
->aux
;
810 bb
->aux
= (void *) group
;
817 union_groups (bb1
, bb2
)
818 basic_block bb1
, bb2
;
820 basic_block bb1g
= find_group (bb1
);
821 basic_block bb2g
= find_group (bb2
);
823 /* ??? I don't have a place for the rank field. OK. Lets go w/o it,
824 this code is unlikely going to be performance problem anyway. */
831 /* This function searches all of the edges in the program flow graph, and puts
832 as many bad edges as possible onto the spanning tree. Bad edges include
833 abnormals edges, which can't be instrumented at the moment. Since it is
834 possible for fake edges to form an cycle, we will have to develop some
835 better way in the future. Also put critical edges to the tree, since they
836 are more expensive to instrument. */
839 find_spanning_tree (el
)
840 struct edge_list
*el
;
843 int num_edges
= NUM_EDGES (el
);
845 /* We use aux field for standard union-find algorithm. */
846 EXIT_BLOCK_PTR
->aux
= EXIT_BLOCK_PTR
;
847 ENTRY_BLOCK_PTR
->aux
= ENTRY_BLOCK_PTR
;
848 for (i
= 0; i
< n_basic_blocks
; i
++)
849 BASIC_BLOCK (i
)->aux
= BASIC_BLOCK (i
);
851 /* Add fake edge exit to entry we can't instrument. */
852 union_groups (EXIT_BLOCK_PTR
, ENTRY_BLOCK_PTR
);
854 /* First add all abnormal edges to the tree unless they form an cycle. */
855 for (i
= 0; i
< num_edges
; i
++)
857 edge e
= INDEX_EDGE (el
, i
);
858 if ((e
->flags
& (EDGE_ABNORMAL
| EDGE_ABNORMAL_CALL
| EDGE_FAKE
))
859 && !EDGE_INFO (e
)->ignore
860 && (find_group (e
->src
) != find_group (e
->dest
)))
862 EDGE_INFO (e
)->on_tree
= 1;
863 union_groups (e
->src
, e
->dest
);
867 /* Now insert all critical edges to the tree unless they form an cycle. */
868 for (i
= 0; i
< num_edges
; i
++)
870 edge e
= INDEX_EDGE (el
, i
);
871 if ((e
->flags
& EDGE_CRITICAL
)
872 && !EDGE_INFO (e
)->ignore
873 && (find_group (e
->src
) != find_group (e
->dest
)))
875 EDGE_INFO (e
)->on_tree
= 1;
876 union_groups (e
->src
, e
->dest
);
880 /* And now the rest. */
881 for (i
= 0; i
< num_edges
; i
++)
883 edge e
= INDEX_EDGE (el
, i
);
884 if (find_group (e
->src
) != find_group (e
->dest
)
885 && !EDGE_INFO (e
)->ignore
)
887 EDGE_INFO (e
)->on_tree
= 1;
888 union_groups (e
->src
, e
->dest
);
893 /* Perform file-level initialization for branch-prob processing. */
896 init_branch_prob (filename
)
897 const char *filename
;
902 if (flag_test_coverage
)
904 int len
= strlen (filename
);
905 char *data_file
, *bbg_file_name
;
907 /* Open an output file for the basic block/line number map. */
908 data_file
= (char *) alloca (len
+ 4);
909 strcpy (data_file
, filename
);
910 strip_off_ending (data_file
, len
);
911 strcat (data_file
, ".bb");
912 if ((bb_file
= fopen (data_file
, "wb")) == 0)
913 fatal_io_error ("can't open %s", data_file
);
915 /* Open an output file for the program flow graph. */
916 bbg_file_name
= (char *) alloca (len
+ 5);
917 strcpy (bbg_file_name
, filename
);
918 strip_off_ending (bbg_file_name
, len
);
919 strcat (bbg_file_name
, ".bbg");
920 if ((bbg_file
= fopen (bbg_file_name
, "wb")) == 0)
921 fatal_io_error ("can't open %s", bbg_file_name
);
923 /* Initialize to zero, to ensure that the first file name will be
924 written to the .bb file. */
925 last_bb_file_name
= 0;
928 if (flag_branch_probabilities
)
932 len
= strlen (filename
);
933 da_file_name
= (char *) alloca (len
+ 4);
934 strcpy (da_file_name
, filename
);
935 strip_off_ending (da_file_name
, len
);
936 strcat (da_file_name
, ".da");
937 if ((da_file
= fopen (da_file_name
, "rb")) == 0)
938 warning ("file %s not found, execution counts assumed to be zero.",
941 /* The first word in the .da file gives the number of instrumented
942 edges, which is not needed for our purposes. */
945 __read_long (&len
, da_file
, 8);
948 if (profile_arc_flag
)
949 init_edge_profiler ();
951 total_num_blocks
= 0;
953 total_num_edges_instrumented
= 0;
954 total_num_blocks_created
= 0;
955 total_num_passes
= 0;
956 total_num_times_called
= 0;
957 total_num_branches
= 0;
958 total_num_never_executed
= 0;
959 for (i
= 0; i
< 20; i
++)
960 total_hist_br_prob
[i
] = 0;
963 /* Performs file-level cleanup after branch-prob processing
969 if (flag_test_coverage
)
975 if (flag_branch_probabilities
)
980 /* This seems slightly dangerous, as it presumes the EOF
981 flag will not be set until an attempt is made to read
982 past the end of the file. */
984 warning (".da file contents exhausted too early\n");
985 /* Should be at end of file now. */
986 if (__read_long (&temp
, da_file
, 8) == 0)
987 warning (".da file contents not exhausted\n");
994 fprintf (rtl_dump_file
, "\n");
995 fprintf (rtl_dump_file
, "Total number of blocks: %d\n",
997 fprintf (rtl_dump_file
, "Total number of edges: %d\n", total_num_edges
);
998 fprintf (rtl_dump_file
, "Total number of instrumented edges: %d\n",
999 total_num_edges_instrumented
);
1000 fprintf (rtl_dump_file
, "Total number of blocks created: %d\n",
1001 total_num_blocks_created
);
1002 fprintf (rtl_dump_file
, "Total number of graph solution passes: %d\n",
1004 if (total_num_times_called
!= 0)
1005 fprintf (rtl_dump_file
, "Average number of graph solution passes: %d\n",
1006 (total_num_passes
+ (total_num_times_called
>> 1))
1007 / total_num_times_called
);
1008 fprintf (rtl_dump_file
, "Total number of branches: %d\n",
1009 total_num_branches
);
1010 fprintf (rtl_dump_file
, "Total number of branches never executed: %d\n",
1011 total_num_never_executed
);
1012 if (total_num_branches
)
1016 for (i
= 0; i
< 10; i
++)
1017 fprintf (rtl_dump_file
, "%d%% branches in range %d-%d%%\n",
1018 (total_hist_br_prob
[i
] + total_hist_br_prob
[19-i
]) * 100
1019 / total_num_branches
, 5*i
, 5*i
+5);
1024 /* The label used by the edge profiling code. */
1026 static rtx profiler_label
;
1028 /* Initialize the profiler_label. */
1031 init_edge_profiler ()
1033 /* Generate and save a copy of this so it can be shared. */
1035 ASM_GENERATE_INTERNAL_LABEL (buf
, "LPBX", 2);
1036 profiler_label
= gen_rtx_SYMBOL_REF (Pmode
, ggc_strdup (buf
));
1037 ggc_add_rtx_root (&profiler_label
, 1);
1040 /* Output instructions as RTL to increment the edge execution count. */
1043 gen_edge_profiler (edgeno
)
1046 enum machine_mode mode
= mode_for_size (GCOV_TYPE_SIZE
, MODE_INT
, 0);
1052 tmp
= force_reg (Pmode
, profiler_label
);
1053 tmp
= plus_constant (tmp
, GCOV_TYPE_SIZE
/ BITS_PER_UNIT
* edgeno
);
1054 mem_ref
= validize_mem (gen_rtx_MEM (mode
, tmp
));
1056 tmp
= expand_binop (mode
, add_optab
, mem_ref
, const1_rtx
,
1057 mem_ref
, 0, OPTAB_WIDEN
);
1060 emit_move_insn (copy_rtx (mem_ref
), tmp
);
1062 sequence
= gen_sequence ();
1067 /* Output code for a constructor that will invoke __bb_init_func, if
1068 this has not already been done. */
1071 output_func_start_profiler ()
1073 tree fnname
, fndecl
;
1076 const char *cfnname
;
1078 enum machine_mode mode
= mode_for_size (GCOV_TYPE_SIZE
, MODE_INT
, 0);
1079 int save_flag_inline_functions
= flag_inline_functions
;
1080 int save_flag_test_coverage
= flag_test_coverage
;
1081 int save_profile_arc_flag
= profile_arc_flag
;
1082 int save_flag_branch_probabilities
= flag_branch_probabilities
;
1084 /* It's either already been output, or we don't need it because we're
1085 not doing profile-edges. */
1086 if (! need_func_profiler
)
1089 need_func_profiler
= 0;
1091 /* Synthesize a constructor function to invoke __bb_init_func with a
1092 pointer to this object file's profile block. */
1094 /* Try and make a unique name given the "file function name".
1096 And no, I don't like this either. */
1098 fnname
= get_file_function_name ('I');
1099 cfnname
= IDENTIFIER_POINTER (fnname
);
1100 name
= concat (cfnname
, "GCOV", NULL
);
1101 fnname
= get_identifier (name
);
1104 fndecl
= build_decl (FUNCTION_DECL
, fnname
,
1105 build_function_type (void_type_node
, NULL_TREE
));
1106 DECL_EXTERNAL (fndecl
) = 0;
1108 #if defined(ASM_OUTPUT_CONSTRUCTOR) && defined(ASM_OUTPUT_DESTRUCTOR)
1109 /* It can be a static function as long as collect2 does not have
1110 to scan the object file to find its ctor/dtor routine. */
1111 TREE_PUBLIC (fndecl
) = 0;
1113 TREE_PUBLIC (fndecl
) = 1;
1116 DECL_RESULT (fndecl
) = build_decl (RESULT_DECL
, NULL_TREE
, void_type_node
);
1118 fndecl
= pushdecl (fndecl
);
1119 rest_of_decl_compilation (fndecl
, 0, 1, 0);
1120 announce_function (fndecl
);
1121 current_function_decl
= fndecl
;
1122 DECL_INITIAL (fndecl
) = error_mark_node
;
1123 make_decl_rtl (fndecl
, NULL
);
1124 init_function_start (fndecl
, input_filename
, lineno
);
1126 expand_function_start (fndecl
, 0);
1128 /* Actually generate the code to call __bb_init_func. */
1129 ASM_GENERATE_INTERNAL_LABEL (buf
, "LPBX", 0);
1130 table_address
= force_reg (Pmode
,
1131 gen_rtx_SYMBOL_REF (Pmode
, ggc_strdup (buf
)));
1132 emit_library_call (gen_rtx_SYMBOL_REF (Pmode
, "__bb_init_func"), 0,
1133 mode
, 1, table_address
, Pmode
);
1135 expand_function_end (input_filename
, lineno
, 0);
1138 /* Since fndecl isn't in the list of globals, it would never be emitted
1139 when it's considered to be 'safe' for inlining, so turn off
1140 flag_inline_functions. */
1141 flag_inline_functions
= 0;
1143 /* Don't instrument the function that turns on instrumentation. Which
1144 is also handy since we'd get silly warnings about not consuming all
1145 of our da_file input. */
1146 flag_test_coverage
= 0;
1147 profile_arc_flag
= 0;
1148 flag_branch_probabilities
= 0;
1150 rest_of_compilation (fndecl
);
1152 /* Reset flag_inline_functions to its original value. */
1153 flag_inline_functions
= save_flag_inline_functions
;
1154 flag_test_coverage
= save_flag_test_coverage
;
1155 profile_arc_flag
= save_profile_arc_flag
;
1156 flag_branch_probabilities
= save_flag_branch_probabilities
;
1159 fflush (asm_out_file
);
1160 current_function_decl
= NULL_TREE
;
1162 assemble_constructor (IDENTIFIER_POINTER (DECL_NAME (fndecl
)));