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-flags.h"
42 #include "insn-config.h"
50 #include "hard-reg-set.h"
51 #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_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_long (&value
, da_file
, 8);
266 EDGE_INFO (e
)->count_valid
= 1;
267 BB_INFO (bb
)->succ_count
--;
268 BB_INFO (e
->dest
)->pred_count
--;
273 fprintf (rtl_dump_file
, "%d edge counts read\n", num_edges
);
275 /* For every block in the file,
276 - if every exit/entrance edge has a known count, then set the block count
277 - if the block count is known, and every exit/entrance edge but one has
278 a known execution count, then set the count of the remaining edge
280 As edge counts are set, decrement the succ/pred count, but don't delete
281 the edge, that way we can easily tell when all edges are known, or only
282 one edge is unknown. */
284 /* The order that the basic blocks are iterated through is important.
285 Since the code that finds spanning trees starts with block 0, low numbered
286 edges are put on the spanning tree in preference to high numbered edges.
287 Hence, most instrumented edges are at the end. Graph solving works much
288 faster if we propagate numbers from the end to the start.
290 This takes an average of slightly more than 3 passes. */
298 for (i
= n_basic_blocks
+ 1; i
>= 0; i
--)
300 basic_block bb
= GCOV_INDEX_TO_BB (i
);
301 struct bb_info
*bi
= BB_INFO (bb
);
302 if (! bi
->count_valid
)
304 if (bi
->succ_count
== 0)
309 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
315 else if (bi
->pred_count
== 0)
320 for (e
= bb
->pred
; e
; e
= e
->pred_next
)
329 if (bi
->succ_count
== 1)
334 /* One of the counts will be invalid, but it is zero,
335 so adding it in also doesn't hurt. */
336 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
339 /* Seedgeh for the invalid edge, and set its count. */
340 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
341 if (! EDGE_INFO (e
)->count_valid
&& ! EDGE_INFO (e
)->ignore
)
344 /* Calculate count for remaining edge by conservation. */
345 total
= bb
->count
- total
;
349 EDGE_INFO (e
)->count_valid
= 1;
353 BB_INFO (e
->dest
)->pred_count
--;
356 if (bi
->pred_count
== 1)
361 /* One of the counts will be invalid, but it is zero,
362 so adding it in also doesn't hurt. */
363 for (e
= bb
->pred
; e
; e
= e
->pred_next
)
366 /* Seedgeh for the invalid edge, and set its count. */
367 for (e
= bb
->pred
; e
; e
= e
->pred_next
)
368 if (! EDGE_INFO (e
)->count_valid
&& ! EDGE_INFO (e
)->ignore
)
371 /* Calculate count for remaining edge by conservation. */
372 total
= bb
->count
- total
+ e
->count
;
376 EDGE_INFO (e
)->count_valid
= 1;
380 BB_INFO (e
->src
)->succ_count
--;
387 dump_flow_info (rtl_dump_file
);
389 total_num_passes
+= passes
;
391 fprintf (rtl_dump_file
, "Graph solving took %d passes.\n\n", passes
);
393 /* If the graph has been correctly solved, every block will have a
394 succ and pred count of zero. */
395 for (i
= 0; i
< n_basic_blocks
; i
++)
397 basic_block bb
= BASIC_BLOCK (i
);
398 if (BB_INFO (bb
)->succ_count
|| BB_INFO (bb
)->pred_count
)
402 /* For every edge, calculate its branch probability and add a reg_note
403 to the branch insn to indicate this. */
405 for (i
= 0; i
< 20; i
++)
407 num_never_executed
= 0;
410 for (i
= 0; i
< n_basic_blocks
; i
++)
412 basic_block bb
= BASIC_BLOCK (i
);
421 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
423 if (any_condjump_p (e
->src
->end
)
424 && !EDGE_INFO (e
)->ignore
425 && !(e
->flags
& (EDGE_ABNORMAL
| EDGE_ABNORMAL_CALL
| EDGE_FAKE
)))
428 /* This calculates the branch probability as an integer between
429 0 and REG_BR_PROB_BASE, properly rounded to the nearest
430 integer. Perform the arithmetic in double to avoid
431 overflowing the range of ints. */
436 prob
= (((double)e
->count
* REG_BR_PROB_BASE
)
437 + (total
>> 1)) / total
;
438 if (prob
< 0 || prob
> REG_BR_PROB_BASE
)
441 fprintf (rtl_dump_file
, "bad count: prob for %d-%d thought to be %d (forcibly normalized)\n",
442 e
->src
->index
, e
->dest
->index
, prob
);
445 prob
= REG_BR_PROB_BASE
/ 2;
448 /* Match up probability with JUMP pattern. */
449 if (e
->flags
& EDGE_FALLTHRU
)
450 prob
= REG_BR_PROB_BASE
- prob
;
454 num_never_executed
++;
457 int index
= prob
* 20 / REG_BR_PROB_BASE
;
460 hist_br_prob
[index
]++;
464 note
= find_reg_note (e
->src
->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
);
470 REG_NOTES (e
->src
->end
)
471 = gen_rtx_EXPR_LIST (REG_BR_PROB
, GEN_INT (prob
),
472 REG_NOTES (e
->src
->end
));
476 /* Add a REG_EXEC_COUNT note to the first instruction of this block. */
477 insn
= next_nonnote_insn (bb
->head
);
479 if (GET_CODE (bb
->head
) == CODE_LABEL
)
480 insn
= next_nonnote_insn (insn
);
482 /* Avoid crash on empty basic blocks. */
483 if (insn
&& INSN_P (insn
))
485 = gen_rtx_EXPR_LIST (REG_EXEC_COUNT
, GEN_INT (total
),
489 /* This should never happen. */
491 warning ("Arc profiling: some edge counts were bad.");
495 fprintf (rtl_dump_file
, "%d branches\n", num_branches
);
496 fprintf (rtl_dump_file
, "%d branches never executed\n",
499 for (i
= 0; i
< 10; i
++)
500 fprintf (rtl_dump_file
, "%d%% branches in range %d-%d%%\n",
501 (hist_br_prob
[i
] + hist_br_prob
[19-i
]) * 100 / num_branches
,
504 total_num_branches
+= num_branches
;
505 total_num_never_executed
+= num_never_executed
;
506 for (i
= 0; i
< 20; i
++)
507 total_hist_br_prob
[i
] += hist_br_prob
[i
];
509 fputc ('\n', rtl_dump_file
);
510 fputc ('\n', rtl_dump_file
);
516 /* Instrument and/or analyze program behavior based on program flow graph.
517 In either case, this function builds a flow graph for the function being
518 compiled. The flow graph is stored in BB_GRAPH.
520 When FLAG_PROFILE_ARCS is nonzero, this function instruments the edges in
521 the flow graph that are needed to reconstruct the dynamic behavior of the
524 When FLAG_BRANCH_PROBABILITIES is nonzero, this function reads auxiliary
525 information from a data file containing edge count information from previous
526 executions of the function being compiled. In this case, the flow graph is
527 annotated with actual execution counts, which are later propagated into the
528 rtl for optimization purposes.
530 Main entry point of this file. */
537 struct edge_info
*edge_infos
;
538 struct edge_list
*el
;
540 /* Start of a function. */
541 if (flag_test_coverage
)
542 output_gcov_string (current_function_name
, (long) -2);
544 total_num_times_called
++;
546 /* We can't handle cyclic regions constructed using abnormal edges.
547 To avoid these we replace every source of abnormal edge by a fake
548 edge from entry node and every destination by fake edge to exit.
549 This keeps graph acyclic and our calculation exact for all normal
550 edges except for exit and entrance ones.
552 We also add fake exit edges for each call and asm statement in the
553 basic, since it may not return. */
555 for (i
= 0; i
< n_basic_blocks
; i
++)
558 int need_exit_edge
= 0, need_entry_edge
= 0;
559 int have_exit_edge
= 0, have_entry_edge
= 0;
560 basic_block bb
= BASIC_BLOCK (i
);
563 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
565 if ((e
->flags
& (EDGE_ABNORMAL
| EDGE_ABNORMAL_CALL
))
566 && e
->dest
!= EXIT_BLOCK_PTR
)
568 if (e
->dest
== EXIT_BLOCK_PTR
)
571 for (e
= bb
->pred
; e
; e
= e
->pred_next
)
573 if ((e
->flags
& (EDGE_ABNORMAL
| EDGE_ABNORMAL_CALL
))
574 && e
->src
!= ENTRY_BLOCK_PTR
)
576 if (e
->src
== ENTRY_BLOCK_PTR
)
580 /* ??? Not strictly needed unless flag_test_coverage, but adding
581 them anyway keeps the .da file consistent. */
582 /* ??? Currently inexact for basic blocks with multiple calls.
583 We need to split blocks here. */
584 for (insn
= bb
->head
;
585 insn
!= NEXT_INSN (bb
->end
);
586 insn
= NEXT_INSN (insn
))
589 if (GET_CODE (insn
) == CALL_INSN
&& !CONST_CALL_P (insn
))
591 else if (GET_CODE (insn
) == INSN
)
593 set
= PATTERN (insn
);
594 if (GET_CODE (set
) == PARALLEL
)
595 set
= XVECEXP (set
, 0, 0);
596 if ((GET_CODE (set
) == ASM_OPERANDS
&& MEM_VOLATILE_P (set
))
597 || GET_CODE (set
) == ASM_INPUT
)
602 if (need_exit_edge
&& !have_exit_edge
)
605 fprintf (rtl_dump_file
, "Adding fake exit edge to bb %i\n",
607 make_edge (NULL
, bb
, EXIT_BLOCK_PTR
, EDGE_FAKE
);
609 if (need_entry_edge
&& !have_entry_edge
)
612 fprintf (rtl_dump_file
, "Adding fake entry edge to bb %i\n",
614 make_edge (NULL
, ENTRY_BLOCK_PTR
, bb
, EDGE_FAKE
);
618 el
= create_edge_list ();
619 num_edges
= NUM_EDGES (el
);
620 edge_infos
= (struct edge_info
*)
621 xcalloc (num_edges
, sizeof (struct edge_info
));
623 for (i
= 0 ; i
< num_edges
; i
++)
625 edge e
= INDEX_EDGE (el
, i
);
627 e
->aux
= &edge_infos
[i
];
629 /* Mark edges we've replaced by fake edges above as ignored. */
630 if ((e
->flags
& (EDGE_ABNORMAL
| EDGE_ABNORMAL_CALL
))
631 && e
->src
!= ENTRY_BLOCK_PTR
&& e
->dest
!= EXIT_BLOCK_PTR
)
632 EDGE_INFO (e
)->ignore
= 1;
635 total_num_blocks
+= n_basic_blocks
+ 2;
637 fprintf (rtl_dump_file
, "%d basic blocks\n", n_basic_blocks
);
639 total_num_edges
+= num_edges
;
641 fprintf (rtl_dump_file
, "%d edges\n", num_edges
);
643 #ifdef ENABLE_CHECKING
647 /* Output line number information about each basic block for
649 if (flag_test_coverage
)
652 for (i
= 0 ; i
< n_basic_blocks
; i
++)
654 basic_block bb
= BASIC_BLOCK (i
);
656 static int ignore_next_note
= 0;
658 /* We are looking for line number notes. Search backward before
659 basic block to find correct ones. */
660 insn
= prev_nonnote_insn (insn
);
664 insn
= NEXT_INSN (insn
);
666 /* Output a zero to the .bb file to indicate that a new
667 block list is starting. */
668 __write_long (0, bb_file
, 4);
670 while (insn
!= bb
->end
)
672 if (GET_CODE (insn
) == NOTE
)
674 /* Must ignore the line number notes that immediately
675 follow the end of an inline function to avoid counting
676 it twice. There is a note before the call, and one
678 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_REPEATED_LINE_NUMBER
)
679 ignore_next_note
= 1;
680 else if (NOTE_LINE_NUMBER (insn
) > 0)
682 if (ignore_next_note
)
683 ignore_next_note
= 0;
686 /* If this is a new source file, then output the
687 file's name to the .bb file. */
688 if (! last_bb_file_name
689 || strcmp (NOTE_SOURCE_FILE (insn
),
692 if (last_bb_file_name
)
693 free (last_bb_file_name
);
695 = xstrdup (NOTE_SOURCE_FILE (insn
));
696 output_gcov_string (NOTE_SOURCE_FILE (insn
),
699 /* Output the line number to the .bb file. Must be
700 done after the output_bb_profile_data() call, and
701 after the file name is written, to ensure that it
702 is correctly handled by gcov. */
703 __write_long (NOTE_LINE_NUMBER (insn
), bb_file
, 4);
707 insn
= NEXT_INSN (insn
);
710 __write_long (0, bb_file
, 4);
713 /* Create spanning tree from basic block graph, mark each edge that is
714 on the spanning tree. We insert as many abnormal and critical edges
715 as possible to minimize number of edge splits necesary. */
717 find_spanning_tree (el
);
719 /* Create a .bbg file from which gcov can reconstruct the basic block
720 graph. First output the number of basic blocks, and then for every
721 edge output the source and target basic block numbers.
722 NOTE: The format of this file must be compatible with gcov. */
724 if (flag_test_coverage
)
728 /* The plus 2 stands for entry and exit block. */
729 __write_long (n_basic_blocks
+ 2, bbg_file
, 4);
730 __write_long (num_edges
+ 1, bbg_file
, 4);
732 for (i
= 0; i
< n_basic_blocks
+ 1; i
++)
734 basic_block bb
= GCOV_INDEX_TO_BB (i
);
738 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
739 if (!EDGE_INFO (e
)->ignore
)
741 __write_long (count
, bbg_file
, 4);
743 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
745 struct edge_info
*i
= EDGE_INFO (e
);
751 if (e
->flags
& EDGE_ABNORMAL
)
753 if (e
->flags
& EDGE_FALLTHRU
)
756 __write_long (BB_TO_GCOV_INDEX (e
->dest
), bbg_file
, 4);
757 __write_long (flag_bits
, bbg_file
, 4);
761 /* Emit fake loopback edge for EXIT block to maitain compatibility with
763 __write_long (1, bbg_file
, 4);
764 __write_long (0, bbg_file
, 4);
765 __write_long (0x1, bbg_file
, 4);
767 /* Emit a -1 to separate the list of all edges from the list of
768 loop back edges that follows. */
769 __write_long (-1, bbg_file
, 4);
772 if (flag_branch_probabilities
)
773 compute_branch_probabilities ();
775 /* For each edge not on the spanning tree, add counting code as rtl. */
777 if (profile_arc_flag
)
779 instrument_edges (el
);
780 allocate_reg_info (max_reg_num (), FALSE
, FALSE
);
783 remove_fake_edges ();
788 /* Union find algorithm implementation for the basic blocks using
795 basic_block group
= bb
, bb1
;
797 while ((basic_block
) group
->aux
!= group
)
798 group
= (basic_block
) group
->aux
;
801 while ((basic_block
) bb
->aux
!= group
)
803 bb1
= (basic_block
) bb
->aux
;
804 bb
->aux
= (void *) group
;
811 union_groups (bb1
, bb2
)
812 basic_block bb1
, bb2
;
814 basic_block bb1g
= find_group (bb1
);
815 basic_block bb2g
= find_group (bb2
);
817 /* ??? I don't have a place for the rank field. OK. Lets go w/o it,
818 this code is unlikely going to be performance problem anyway. */
825 /* This function searches all of the edges in the program flow graph, and puts
826 as many bad edges as possible onto the spanning tree. Bad edges include
827 abnormals edges, which can't be instrumented at the moment. Since it is
828 possible for fake edges to form an cycle, we will have to develop some
829 better way in the future. Also put critical edges to the tree, since they
830 are more expensive to instrument. */
833 find_spanning_tree (el
)
834 struct edge_list
*el
;
837 int num_edges
= NUM_EDGES (el
);
839 /* We use aux field for standard union-find algorithm. */
840 EXIT_BLOCK_PTR
->aux
= EXIT_BLOCK_PTR
;
841 ENTRY_BLOCK_PTR
->aux
= ENTRY_BLOCK_PTR
;
842 for (i
= 0; i
< n_basic_blocks
; i
++)
843 BASIC_BLOCK (i
)->aux
= BASIC_BLOCK (i
);
845 /* Add fake edge exit to entry we can't instrument. */
846 union_groups (EXIT_BLOCK_PTR
, ENTRY_BLOCK_PTR
);
848 /* First add all abnormal edges to the tree unless they form an cycle. */
849 for (i
= 0; i
< num_edges
; i
++)
851 edge e
= INDEX_EDGE (el
, i
);
852 if ((e
->flags
& (EDGE_ABNORMAL
| EDGE_ABNORMAL_CALL
| EDGE_FAKE
))
853 && !EDGE_INFO (e
)->ignore
854 && (find_group (e
->src
) != find_group (e
->dest
)))
856 EDGE_INFO (e
)->on_tree
= 1;
857 union_groups (e
->src
, e
->dest
);
861 /* Now insert all critical edges to the tree unless they form an cycle. */
862 for (i
= 0; i
< num_edges
; i
++)
864 edge e
= INDEX_EDGE (el
, i
);
865 if ((e
->flags
& EDGE_CRITICAL
)
866 && !EDGE_INFO (e
)->ignore
867 && (find_group (e
->src
) != find_group (e
->dest
)))
869 EDGE_INFO (e
)->on_tree
= 1;
870 union_groups (e
->src
, e
->dest
);
874 /* And now the rest. */
875 for (i
= 0; i
< num_edges
; i
++)
877 edge e
= INDEX_EDGE (el
, i
);
878 if (find_group (e
->src
) != find_group (e
->dest
)
879 && !EDGE_INFO (e
)->ignore
)
881 EDGE_INFO (e
)->on_tree
= 1;
882 union_groups (e
->src
, e
->dest
);
887 /* Perform file-level initialization for branch-prob processing. */
890 init_branch_prob (filename
)
891 const char *filename
;
896 if (flag_test_coverage
)
898 int len
= strlen (filename
);
899 char *data_file
, *bbg_file_name
;
901 /* Open an output file for the basic block/line number map. */
902 data_file
= (char *) alloca (len
+ 4);
903 strcpy (data_file
, filename
);
904 strip_off_ending (data_file
, len
);
905 strcat (data_file
, ".bb");
906 if ((bb_file
= fopen (data_file
, "wb")) == 0)
907 pfatal_with_name (data_file
);
909 /* Open an output file for the program flow graph. */
910 bbg_file_name
= (char *) alloca (len
+ 5);
911 strcpy (bbg_file_name
, filename
);
912 strip_off_ending (bbg_file_name
, len
);
913 strcat (bbg_file_name
, ".bbg");
914 if ((bbg_file
= fopen (bbg_file_name
, "wb")) == 0)
915 pfatal_with_name (bbg_file_name
);
917 /* Initialize to zero, to ensure that the first file name will be
918 written to the .bb file. */
919 last_bb_file_name
= 0;
922 if (flag_branch_probabilities
)
926 len
= strlen (filename
);
927 da_file_name
= (char *) alloca (len
+ 4);
928 strcpy (da_file_name
, filename
);
929 strip_off_ending (da_file_name
, len
);
930 strcat (da_file_name
, ".da");
931 if ((da_file
= fopen (da_file_name
, "rb")) == 0)
932 warning ("file %s not found, execution counts assumed to be zero.",
935 /* The first word in the .da file gives the number of instrumented
936 edges, which is not needed for our purposes. */
939 __read_long (&len
, da_file
, 8);
942 if (profile_arc_flag
)
943 init_edge_profiler ();
945 total_num_blocks
= 0;
947 total_num_edges_instrumented
= 0;
948 total_num_blocks_created
= 0;
949 total_num_passes
= 0;
950 total_num_times_called
= 0;
951 total_num_branches
= 0;
952 total_num_never_executed
= 0;
953 for (i
= 0; i
< 20; i
++)
954 total_hist_br_prob
[i
] = 0;
957 /* Performs file-level cleanup after branch-prob processing
963 if (flag_test_coverage
)
969 if (flag_branch_probabilities
)
974 /* This seems slightly dangerous, as it presumes the EOF
975 flag will not be set until an attempt is made to read
976 past the end of the file. */
978 warning (".da file contents exhausted too early\n");
979 /* Should be at end of file now. */
980 if (__read_long (&temp
, da_file
, 8) == 0)
981 warning (".da file contents not exhausted\n");
988 fprintf (rtl_dump_file
, "\n");
989 fprintf (rtl_dump_file
, "Total number of blocks: %d\n",
991 fprintf (rtl_dump_file
, "Total number of edges: %d\n", total_num_edges
);
992 fprintf (rtl_dump_file
, "Total number of instrumented edges: %d\n",
993 total_num_edges_instrumented
);
994 fprintf (rtl_dump_file
, "Total number of blocks created: %d\n",
995 total_num_blocks_created
);
996 fprintf (rtl_dump_file
, "Total number of graph solution passes: %d\n",
998 if (total_num_times_called
!= 0)
999 fprintf (rtl_dump_file
, "Average number of graph solution passes: %d\n",
1000 (total_num_passes
+ (total_num_times_called
>> 1))
1001 / total_num_times_called
);
1002 fprintf (rtl_dump_file
, "Total number of branches: %d\n",
1003 total_num_branches
);
1004 fprintf (rtl_dump_file
, "Total number of branches never executed: %d\n",
1005 total_num_never_executed
);
1006 if (total_num_branches
)
1010 for (i
= 0; i
< 10; i
++)
1011 fprintf (rtl_dump_file
, "%d%% branches in range %d-%d%%\n",
1012 (total_hist_br_prob
[i
] + total_hist_br_prob
[19-i
]) * 100
1013 / total_num_branches
, 5*i
, 5*i
+5);
1018 /* The label used by the edge profiling code. */
1020 static rtx profiler_label
;
1022 /* Initialize the profiler_label. */
1025 init_edge_profiler ()
1027 /* Generate and save a copy of this so it can be shared. */
1029 ASM_GENERATE_INTERNAL_LABEL (buf
, "LPBX", 2);
1030 profiler_label
= gen_rtx_SYMBOL_REF (Pmode
, ggc_strdup (buf
));
1031 ggc_add_rtx_root (&profiler_label
, 1);
1034 /* Output instructions as RTL to increment the edge execution count. */
1037 gen_edge_profiler (edgeno
)
1040 enum machine_mode mode
= mode_for_size (LONG_TYPE_SIZE
, MODE_INT
, 0);
1046 tmp
= force_reg (Pmode
, profiler_label
);
1047 tmp
= plus_constant (tmp
, LONG_TYPE_SIZE
/ BITS_PER_UNIT
* edgeno
);
1048 mem_ref
= validize_mem (gen_rtx_MEM (mode
, tmp
));
1050 tmp
= expand_binop (mode
, add_optab
, mem_ref
, const1_rtx
,
1051 mem_ref
, 0, OPTAB_WIDEN
);
1054 emit_move_insn (copy_rtx (mem_ref
), tmp
);
1056 sequence
= gen_sequence ();
1061 /* Output code for a constructor that will invoke __bb_init_func, if
1062 this has not already been done. */
1065 output_func_start_profiler ()
1067 tree fnname
, fndecl
;
1070 const char *cfnname
;
1072 enum machine_mode mode
= mode_for_size (LONG_TYPE_SIZE
, MODE_INT
, 0);
1073 int save_flag_inline_functions
= flag_inline_functions
;
1074 int save_flag_test_coverage
= flag_test_coverage
;
1075 int save_profile_arc_flag
= profile_arc_flag
;
1076 int save_flag_branch_probabilities
= flag_branch_probabilities
;
1078 /* It's either already been output, or we don't need it because we're
1079 not doing profile-edges. */
1080 if (! need_func_profiler
)
1083 need_func_profiler
= 0;
1085 /* Synthesize a constructor function to invoke __bb_init_func with a
1086 pointer to this object file's profile block. */
1088 /* Try and make a unique name given the "file function name".
1090 And no, I don't like this either. */
1092 fnname
= get_file_function_name ('I');
1093 cfnname
= IDENTIFIER_POINTER (fnname
);
1094 name
= xmalloc (strlen (cfnname
) + 5);
1095 sprintf (name
, "%sGCOV",cfnname
);
1096 fnname
= get_identifier (name
);
1099 fndecl
= build_decl (FUNCTION_DECL
, fnname
,
1100 build_function_type (void_type_node
, NULL_TREE
));
1101 DECL_EXTERNAL (fndecl
) = 0;
1103 #if defined(ASM_OUTPUT_CONSTRUCTOR) && defined(ASM_OUTPUT_DESTRUCTOR)
1104 /* It can be a static function as long as collect2 does not have
1105 to scan the object file to find its ctor/dtor routine. */
1106 TREE_PUBLIC (fndecl
) = 0;
1108 TREE_PUBLIC (fndecl
) = 1;
1111 DECL_ASSEMBLER_NAME (fndecl
) = fnname
;
1112 DECL_RESULT (fndecl
) = build_decl (RESULT_DECL
, NULL_TREE
, void_type_node
);
1114 fndecl
= pushdecl (fndecl
);
1115 rest_of_decl_compilation (fndecl
, 0, 1, 0);
1116 announce_function (fndecl
);
1117 current_function_decl
= fndecl
;
1118 DECL_INITIAL (fndecl
) = error_mark_node
;
1119 make_decl_rtl (fndecl
, NULL
);
1120 init_function_start (fndecl
, input_filename
, lineno
);
1122 expand_function_start (fndecl
, 0);
1124 /* Actually generate the code to call __bb_init_func. */
1125 ASM_GENERATE_INTERNAL_LABEL (buf
, "LPBX", 0);
1126 table_address
= force_reg (Pmode
,
1127 gen_rtx_SYMBOL_REF (Pmode
, ggc_strdup (buf
)));
1128 emit_library_call (gen_rtx_SYMBOL_REF (Pmode
, "__bb_init_func"), 0,
1129 mode
, 1, table_address
, Pmode
);
1131 expand_function_end (input_filename
, lineno
, 0);
1134 /* Since fndecl isn't in the list of globals, it would never be emitted
1135 when it's considered to be 'safe' for inlining, so turn off
1136 flag_inline_functions. */
1137 flag_inline_functions
= 0;
1139 /* Don't instrument the function that turns on instrumentation. Which
1140 is also handy since we'd get silly warnings about not consuming all
1141 of our da_file input. */
1142 flag_test_coverage
= 0;
1143 profile_arc_flag
= 0;
1144 flag_branch_probabilities
= 0;
1146 rest_of_compilation (fndecl
);
1148 /* Reset flag_inline_functions to its original value. */
1149 flag_inline_functions
= save_flag_inline_functions
;
1150 flag_test_coverage
= save_flag_test_coverage
;
1151 profile_arc_flag
= save_profile_arc_flag
;
1152 flag_branch_probabilities
= save_flag_branch_probabilities
;
1155 fflush (asm_out_file
);
1156 current_function_decl
= NULL_TREE
;
1158 assemble_constructor (IDENTIFIER_POINTER (DECL_NAME (fndecl
)));