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 "hard-reg-set.h"
50 #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 #ifndef LONG_TYPE_SIZE
123 #define LONG_TYPE_SIZE BITS_PER_WORD
126 /* If non-zero, we need to output a constructor to set up the
127 per-object-file data. */
128 static int need_func_profiler
= 0;
130 /* Add edge instrumentation code to the entire insn chain.
132 F is the first insn of the chain.
133 NUM_BLOCKS is the number of basic blocks found in F. */
136 instrument_edges (el
)
137 struct edge_list
*el
;
140 int num_instr_edges
= 0;
141 int num_edges
= NUM_EDGES (el
);
142 remove_fake_edges ();
144 for (i
= 0; i
< n_basic_blocks
+ 2; i
++)
146 basic_block bb
= GCOV_INDEX_TO_BB (i
);
150 struct edge_info
*inf
= EDGE_INFO (e
);
151 if (!inf
->ignore
&& !inf
->on_tree
)
153 if (e
->flags
& EDGE_ABNORMAL
)
156 fprintf (rtl_dump_file
, "Edge %d to %d instrumented%s\n",
157 e
->src
->index
, e
->dest
->index
,
158 e
->flags
& EDGE_CRITICAL
? " (and split)" : "");
159 need_func_profiler
= 1;
160 insert_insn_on_edge (
161 gen_edge_profiler (total_num_edges_instrumented
162 + num_instr_edges
++), e
);
168 total_num_edges_instrumented
+= num_instr_edges
;
169 count_instrumented_edges
= total_num_edges_instrumented
;
171 total_num_blocks_created
+= num_edges
;
173 fprintf (rtl_dump_file
, "%d edges instrumented\n", num_instr_edges
);
175 commit_edge_insertions ();
178 /* Output STRING to bb_file, surrounded by DELIMITER. */
181 output_gcov_string (string
, delimiter
)
187 /* Write a delimiter to indicate that a file name follows. */
188 __write_long (delimiter
, bb_file
, 4);
190 /* Write the string. */
191 temp
= strlen (string
) + 1;
192 fwrite (string
, temp
, 1, bb_file
);
194 /* Append a few zeros, to align the output to a 4 byte boundary. */
200 c
[0] = c
[1] = c
[2] = c
[3] = 0;
201 fwrite (c
, sizeof (char), 4 - temp
, bb_file
);
204 /* Store another delimiter in the .bb file, just to make it easy to find
205 the end of the file name. */
206 __write_long (delimiter
, bb_file
, 4);
210 /* Compute the branch probabilities for the various branches.
211 Annotate them accordingly. */
214 compute_branch_probabilities ()
220 int hist_br_prob
[20];
221 int num_never_executed
;
224 struct bb_info
*bb_infos
;
226 /* Attach extra info block to each bb. */
228 bb_infos
= (struct bb_info
*)
229 xcalloc (n_basic_blocks
+ 2, sizeof (struct bb_info
));
230 for (i
= 0; i
< n_basic_blocks
+ 2; i
++)
232 basic_block bb
= GCOV_INDEX_TO_BB (i
);
235 bb
->aux
= &bb_infos
[i
];
236 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
237 if (!EDGE_INFO (e
)->ignore
)
238 BB_INFO (bb
)->succ_count
++;
239 for (e
= bb
->pred
; e
; e
= e
->pred_next
)
240 if (!EDGE_INFO (e
)->ignore
)
241 BB_INFO (bb
)->pred_count
++;
244 /* Avoid predicting entry on exit nodes. */
245 BB_INFO (EXIT_BLOCK_PTR
)->succ_count
= 2;
246 BB_INFO (ENTRY_BLOCK_PTR
)->pred_count
= 2;
248 /* For each edge not on the spanning tree, set its execution count from
251 /* The first count in the .da file is the number of times that the function
252 was entered. This is the exec_count for block zero. */
254 for (i
= 0; i
< n_basic_blocks
+ 2; i
++)
256 basic_block bb
= GCOV_INDEX_TO_BB (i
);
258 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
259 if (!EDGE_INFO (e
)->ignore
&& !EDGE_INFO (e
)->on_tree
)
265 __read_long (&value
, da_file
, 8);
270 EDGE_INFO (e
)->count_valid
= 1;
271 BB_INFO (bb
)->succ_count
--;
272 BB_INFO (e
->dest
)->pred_count
--;
277 fprintf (rtl_dump_file
, "%d edge counts read\n", num_edges
);
279 /* For every block in the file,
280 - if every exit/entrance edge has a known count, then set the block count
281 - if the block count is known, and every exit/entrance edge but one has
282 a known execution count, then set the count of the remaining edge
284 As edge counts are set, decrement the succ/pred count, but don't delete
285 the edge, that way we can easily tell when all edges are known, or only
286 one edge is unknown. */
288 /* The order that the basic blocks are iterated through is important.
289 Since the code that finds spanning trees starts with block 0, low numbered
290 edges are put on the spanning tree in preference to high numbered edges.
291 Hence, most instrumented edges are at the end. Graph solving works much
292 faster if we propagate numbers from the end to the start.
294 This takes an average of slightly more than 3 passes. */
302 for (i
= n_basic_blocks
+ 1; i
>= 0; i
--)
304 basic_block bb
= GCOV_INDEX_TO_BB (i
);
305 struct bb_info
*bi
= BB_INFO (bb
);
306 if (! bi
->count_valid
)
308 if (bi
->succ_count
== 0)
313 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
319 else if (bi
->pred_count
== 0)
324 for (e
= bb
->pred
; e
; e
= e
->pred_next
)
333 if (bi
->succ_count
== 1)
338 /* One of the counts will be invalid, but it is zero,
339 so adding it in also doesn't hurt. */
340 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
343 /* Seedgeh for the invalid edge, and set its count. */
344 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
345 if (! EDGE_INFO (e
)->count_valid
&& ! EDGE_INFO (e
)->ignore
)
348 /* Calculate count for remaining edge by conservation. */
349 total
= bb
->count
- total
;
353 EDGE_INFO (e
)->count_valid
= 1;
357 BB_INFO (e
->dest
)->pred_count
--;
360 if (bi
->pred_count
== 1)
365 /* One of the counts will be invalid, but it is zero,
366 so adding it in also doesn't hurt. */
367 for (e
= bb
->pred
; e
; e
= e
->pred_next
)
370 /* Seedgeh for the invalid edge, and set its count. */
371 for (e
= bb
->pred
; e
; e
= e
->pred_next
)
372 if (! EDGE_INFO (e
)->count_valid
&& ! EDGE_INFO (e
)->ignore
)
375 /* Calculate count for remaining edge by conservation. */
376 total
= bb
->count
- total
+ e
->count
;
380 EDGE_INFO (e
)->count_valid
= 1;
384 BB_INFO (e
->src
)->succ_count
--;
391 dump_flow_info (rtl_dump_file
);
393 total_num_passes
+= passes
;
395 fprintf (rtl_dump_file
, "Graph solving took %d passes.\n\n", passes
);
397 /* If the graph has been correctly solved, every block will have a
398 succ and pred count of zero. */
399 for (i
= 0; i
< n_basic_blocks
; i
++)
401 basic_block bb
= BASIC_BLOCK (i
);
402 if (BB_INFO (bb
)->succ_count
|| BB_INFO (bb
)->pred_count
)
406 /* For every edge, calculate its branch probability and add a reg_note
407 to the branch insn to indicate this. */
409 for (i
= 0; i
< 20; i
++)
411 num_never_executed
= 0;
414 for (i
= 0; i
< n_basic_blocks
; i
++)
416 basic_block bb
= BASIC_BLOCK (i
);
425 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
427 if (any_condjump_p (e
->src
->end
)
428 && !EDGE_INFO (e
)->ignore
429 && !(e
->flags
& (EDGE_ABNORMAL
| EDGE_ABNORMAL_CALL
| EDGE_FAKE
)))
432 /* This calculates the branch probability as an integer between
433 0 and REG_BR_PROB_BASE, properly rounded to the nearest
434 integer. Perform the arithmetic in double to avoid
435 overflowing the range of ints. */
440 prob
= (((double)e
->count
* REG_BR_PROB_BASE
)
441 + (total
>> 1)) / total
;
442 if (prob
< 0 || prob
> REG_BR_PROB_BASE
)
445 fprintf (rtl_dump_file
, "bad count: prob for %d-%d thought to be %d (forcibly normalized)\n",
446 e
->src
->index
, e
->dest
->index
, prob
);
449 prob
= REG_BR_PROB_BASE
/ 2;
452 /* Match up probability with JUMP pattern. */
453 if (e
->flags
& EDGE_FALLTHRU
)
454 prob
= REG_BR_PROB_BASE
- prob
;
458 num_never_executed
++;
461 int index
= prob
* 20 / REG_BR_PROB_BASE
;
464 hist_br_prob
[index
]++;
468 note
= find_reg_note (e
->src
->end
, REG_BR_PROB
, 0);
469 /* There may be already note put by some other pass, such
470 as builtin_expect expander. */
472 XEXP (note
, 0) = GEN_INT (prob
);
474 REG_NOTES (e
->src
->end
)
475 = gen_rtx_EXPR_LIST (REG_BR_PROB
, GEN_INT (prob
),
476 REG_NOTES (e
->src
->end
));
480 /* Add a REG_EXEC_COUNT note to the first instruction of this block. */
481 insn
= next_nonnote_insn (bb
->head
);
483 if (GET_CODE (bb
->head
) == CODE_LABEL
)
484 insn
= next_nonnote_insn (insn
);
486 /* Avoid crash on empty basic blocks. */
487 if (insn
&& INSN_P (insn
))
489 = gen_rtx_EXPR_LIST (REG_EXEC_COUNT
, GEN_INT (total
),
493 /* This should never happen. */
495 warning ("Arc profiling: some edge counts were bad.");
499 fprintf (rtl_dump_file
, "%d branches\n", num_branches
);
500 fprintf (rtl_dump_file
, "%d branches never executed\n",
503 for (i
= 0; i
< 10; i
++)
504 fprintf (rtl_dump_file
, "%d%% branches in range %d-%d%%\n",
505 (hist_br_prob
[i
] + hist_br_prob
[19-i
]) * 100 / num_branches
,
508 total_num_branches
+= num_branches
;
509 total_num_never_executed
+= num_never_executed
;
510 for (i
= 0; i
< 20; i
++)
511 total_hist_br_prob
[i
] += hist_br_prob
[i
];
513 fputc ('\n', rtl_dump_file
);
514 fputc ('\n', rtl_dump_file
);
520 /* Instrument and/or analyze program behavior based on program flow graph.
521 In either case, this function builds a flow graph for the function being
522 compiled. The flow graph is stored in BB_GRAPH.
524 When FLAG_PROFILE_ARCS is nonzero, this function instruments the edges in
525 the flow graph that are needed to reconstruct the dynamic behavior of the
528 When FLAG_BRANCH_PROBABILITIES is nonzero, this function reads auxiliary
529 information from a data file containing edge count information from previous
530 executions of the function being compiled. In this case, the flow graph is
531 annotated with actual execution counts, which are later propagated into the
532 rtl for optimization purposes.
534 Main entry point of this file. */
541 struct edge_info
*edge_infos
;
542 struct edge_list
*el
;
544 /* Start of a function. */
545 if (flag_test_coverage
)
546 output_gcov_string (current_function_name
, (long) -2);
548 total_num_times_called
++;
550 /* We can't handle cyclic regions constructed using abnormal edges.
551 To avoid these we replace every source of abnormal edge by a fake
552 edge from entry node and every destination by fake edge to exit.
553 This keeps graph acyclic and our calculation exact for all normal
554 edges except for exit and entrance ones.
556 We also add fake exit edges for each call and asm statement in the
557 basic, since it may not return. */
559 for (i
= 0; i
< n_basic_blocks
; i
++)
562 int need_exit_edge
= 0, need_entry_edge
= 0;
563 int have_exit_edge
= 0, have_entry_edge
= 0;
564 basic_block bb
= BASIC_BLOCK (i
);
567 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
569 if ((e
->flags
& (EDGE_ABNORMAL
| EDGE_ABNORMAL_CALL
))
570 && e
->dest
!= EXIT_BLOCK_PTR
)
572 if (e
->dest
== EXIT_BLOCK_PTR
)
575 for (e
= bb
->pred
; e
; e
= e
->pred_next
)
577 if ((e
->flags
& (EDGE_ABNORMAL
| EDGE_ABNORMAL_CALL
))
578 && e
->src
!= ENTRY_BLOCK_PTR
)
580 if (e
->src
== ENTRY_BLOCK_PTR
)
584 /* ??? Not strictly needed unless flag_test_coverage, but adding
585 them anyway keeps the .da file consistent. */
586 /* ??? Currently inexact for basic blocks with multiple calls.
587 We need to split blocks here. */
588 for (insn
= bb
->head
;
589 insn
!= NEXT_INSN (bb
->end
);
590 insn
= NEXT_INSN (insn
))
593 if (GET_CODE (insn
) == CALL_INSN
&& !CONST_CALL_P (insn
))
595 else if (GET_CODE (insn
) == INSN
)
597 set
= PATTERN (insn
);
598 if (GET_CODE (set
) == PARALLEL
)
599 set
= XVECEXP (set
, 0, 0);
600 if ((GET_CODE (set
) == ASM_OPERANDS
&& MEM_VOLATILE_P (set
))
601 || GET_CODE (set
) == ASM_INPUT
)
606 if (need_exit_edge
&& !have_exit_edge
)
609 fprintf (rtl_dump_file
, "Adding fake exit edge to bb %i\n",
611 make_edge (NULL
, bb
, EXIT_BLOCK_PTR
, EDGE_FAKE
);
613 if (need_entry_edge
&& !have_entry_edge
)
616 fprintf (rtl_dump_file
, "Adding fake entry edge to bb %i\n",
618 make_edge (NULL
, ENTRY_BLOCK_PTR
, bb
, EDGE_FAKE
);
622 el
= create_edge_list ();
623 num_edges
= NUM_EDGES (el
);
624 edge_infos
= (struct edge_info
*)
625 xcalloc (num_edges
, sizeof (struct edge_info
));
627 for (i
= 0 ; i
< num_edges
; i
++)
629 edge e
= INDEX_EDGE (el
, i
);
631 e
->aux
= &edge_infos
[i
];
633 /* Mark edges we've replaced by fake edges above as ignored. */
634 if ((e
->flags
& (EDGE_ABNORMAL
| EDGE_ABNORMAL_CALL
))
635 && e
->src
!= ENTRY_BLOCK_PTR
&& e
->dest
!= EXIT_BLOCK_PTR
)
636 EDGE_INFO (e
)->ignore
= 1;
639 total_num_blocks
+= n_basic_blocks
+ 2;
641 fprintf (rtl_dump_file
, "%d basic blocks\n", n_basic_blocks
);
643 total_num_edges
+= num_edges
;
645 fprintf (rtl_dump_file
, "%d edges\n", num_edges
);
647 #ifdef ENABLE_CHECKING
651 /* Output line number information about each basic block for
653 if (flag_test_coverage
)
656 for (i
= 0 ; i
< n_basic_blocks
; i
++)
658 basic_block bb
= BASIC_BLOCK (i
);
660 static int ignore_next_note
= 0;
662 /* We are looking for line number notes. Search backward before
663 basic block to find correct ones. */
664 insn
= prev_nonnote_insn (insn
);
668 insn
= NEXT_INSN (insn
);
670 /* Output a zero to the .bb file to indicate that a new
671 block list is starting. */
672 __write_long (0, bb_file
, 4);
674 while (insn
!= bb
->end
)
676 if (GET_CODE (insn
) == NOTE
)
678 /* Must ignore the line number notes that immediately
679 follow the end of an inline function to avoid counting
680 it twice. There is a note before the call, and one
682 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_REPEATED_LINE_NUMBER
)
683 ignore_next_note
= 1;
684 else if (NOTE_LINE_NUMBER (insn
) > 0)
686 if (ignore_next_note
)
687 ignore_next_note
= 0;
690 /* If this is a new source file, then output the
691 file's name to the .bb file. */
692 if (! last_bb_file_name
693 || strcmp (NOTE_SOURCE_FILE (insn
),
696 if (last_bb_file_name
)
697 free (last_bb_file_name
);
699 = xstrdup (NOTE_SOURCE_FILE (insn
));
700 output_gcov_string (NOTE_SOURCE_FILE (insn
),
703 /* Output the line number to the .bb file. Must be
704 done after the output_bb_profile_data() call, and
705 after the file name is written, to ensure that it
706 is correctly handled by gcov. */
707 __write_long (NOTE_LINE_NUMBER (insn
), bb_file
, 4);
711 insn
= NEXT_INSN (insn
);
714 __write_long (0, bb_file
, 4);
717 /* Create spanning tree from basic block graph, mark each edge that is
718 on the spanning tree. We insert as many abnormal and critical edges
719 as possible to minimize number of edge splits necesary. */
721 find_spanning_tree (el
);
723 /* Create a .bbg file from which gcov can reconstruct the basic block
724 graph. First output the number of basic blocks, and then for every
725 edge output the source and target basic block numbers.
726 NOTE: The format of this file must be compatible with gcov. */
728 if (flag_test_coverage
)
732 /* The plus 2 stands for entry and exit block. */
733 __write_long (n_basic_blocks
+ 2, bbg_file
, 4);
734 __write_long (num_edges
+ 1, bbg_file
, 4);
736 for (i
= 0; i
< n_basic_blocks
+ 1; i
++)
738 basic_block bb
= GCOV_INDEX_TO_BB (i
);
742 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
743 if (!EDGE_INFO (e
)->ignore
)
745 __write_long (count
, bbg_file
, 4);
747 for (e
= bb
->succ
; e
; e
= e
->succ_next
)
749 struct edge_info
*i
= EDGE_INFO (e
);
755 if (e
->flags
& EDGE_ABNORMAL
)
757 if (e
->flags
& EDGE_FALLTHRU
)
760 __write_long (BB_TO_GCOV_INDEX (e
->dest
), bbg_file
, 4);
761 __write_long (flag_bits
, bbg_file
, 4);
765 /* Emit fake loopback edge for EXIT block to maitain compatibility with
767 __write_long (1, bbg_file
, 4);
768 __write_long (0, bbg_file
, 4);
769 __write_long (0x1, bbg_file
, 4);
771 /* Emit a -1 to separate the list of all edges from the list of
772 loop back edges that follows. */
773 __write_long (-1, bbg_file
, 4);
776 if (flag_branch_probabilities
)
777 compute_branch_probabilities ();
779 /* For each edge not on the spanning tree, add counting code as rtl. */
781 if (profile_arc_flag
)
783 instrument_edges (el
);
784 allocate_reg_info (max_reg_num (), FALSE
, FALSE
);
787 remove_fake_edges ();
792 /* Union find algorithm implementation for the basic blocks using
799 basic_block group
= bb
, bb1
;
801 while ((basic_block
) group
->aux
!= group
)
802 group
= (basic_block
) group
->aux
;
805 while ((basic_block
) bb
->aux
!= group
)
807 bb1
= (basic_block
) bb
->aux
;
808 bb
->aux
= (void *) group
;
815 union_groups (bb1
, bb2
)
816 basic_block bb1
, bb2
;
818 basic_block bb1g
= find_group (bb1
);
819 basic_block bb2g
= find_group (bb2
);
821 /* ??? I don't have a place for the rank field. OK. Lets go w/o it,
822 this code is unlikely going to be performance problem anyway. */
829 /* This function searches all of the edges in the program flow graph, and puts
830 as many bad edges as possible onto the spanning tree. Bad edges include
831 abnormals edges, which can't be instrumented at the moment. Since it is
832 possible for fake edges to form an cycle, we will have to develop some
833 better way in the future. Also put critical edges to the tree, since they
834 are more expensive to instrument. */
837 find_spanning_tree (el
)
838 struct edge_list
*el
;
841 int num_edges
= NUM_EDGES (el
);
843 /* We use aux field for standard union-find algorithm. */
844 EXIT_BLOCK_PTR
->aux
= EXIT_BLOCK_PTR
;
845 ENTRY_BLOCK_PTR
->aux
= ENTRY_BLOCK_PTR
;
846 for (i
= 0; i
< n_basic_blocks
; i
++)
847 BASIC_BLOCK (i
)->aux
= BASIC_BLOCK (i
);
849 /* Add fake edge exit to entry we can't instrument. */
850 union_groups (EXIT_BLOCK_PTR
, ENTRY_BLOCK_PTR
);
852 /* First add all abnormal edges to the tree unless they form an cycle. */
853 for (i
= 0; i
< num_edges
; i
++)
855 edge e
= INDEX_EDGE (el
, i
);
856 if ((e
->flags
& (EDGE_ABNORMAL
| EDGE_ABNORMAL_CALL
| EDGE_FAKE
))
857 && !EDGE_INFO (e
)->ignore
858 && (find_group (e
->src
) != find_group (e
->dest
)))
860 EDGE_INFO (e
)->on_tree
= 1;
861 union_groups (e
->src
, e
->dest
);
865 /* Now insert all critical edges to the tree unless they form an cycle. */
866 for (i
= 0; i
< num_edges
; i
++)
868 edge e
= INDEX_EDGE (el
, i
);
869 if ((e
->flags
& EDGE_CRITICAL
)
870 && !EDGE_INFO (e
)->ignore
871 && (find_group (e
->src
) != find_group (e
->dest
)))
873 EDGE_INFO (e
)->on_tree
= 1;
874 union_groups (e
->src
, e
->dest
);
878 /* And now the rest. */
879 for (i
= 0; i
< num_edges
; i
++)
881 edge e
= INDEX_EDGE (el
, i
);
882 if (find_group (e
->src
) != find_group (e
->dest
)
883 && !EDGE_INFO (e
)->ignore
)
885 EDGE_INFO (e
)->on_tree
= 1;
886 union_groups (e
->src
, e
->dest
);
891 /* Perform file-level initialization for branch-prob processing. */
894 init_branch_prob (filename
)
895 const char *filename
;
900 if (flag_test_coverage
)
902 int len
= strlen (filename
);
903 char *data_file
, *bbg_file_name
;
905 /* Open an output file for the basic block/line number map. */
906 data_file
= (char *) alloca (len
+ 4);
907 strcpy (data_file
, filename
);
908 strip_off_ending (data_file
, len
);
909 strcat (data_file
, ".bb");
910 if ((bb_file
= fopen (data_file
, "wb")) == 0)
911 pfatal_with_name (data_file
);
913 /* Open an output file for the program flow graph. */
914 bbg_file_name
= (char *) alloca (len
+ 5);
915 strcpy (bbg_file_name
, filename
);
916 strip_off_ending (bbg_file_name
, len
);
917 strcat (bbg_file_name
, ".bbg");
918 if ((bbg_file
= fopen (bbg_file_name
, "wb")) == 0)
919 pfatal_with_name (bbg_file_name
);
921 /* Initialize to zero, to ensure that the first file name will be
922 written to the .bb file. */
923 last_bb_file_name
= 0;
926 if (flag_branch_probabilities
)
930 len
= strlen (filename
);
931 da_file_name
= (char *) alloca (len
+ 4);
932 strcpy (da_file_name
, filename
);
933 strip_off_ending (da_file_name
, len
);
934 strcat (da_file_name
, ".da");
935 if ((da_file
= fopen (da_file_name
, "rb")) == 0)
936 warning ("file %s not found, execution counts assumed to be zero.",
939 /* The first word in the .da file gives the number of instrumented
940 edges, which is not needed for our purposes. */
943 __read_long (&len
, da_file
, 8);
946 if (profile_arc_flag
)
947 init_edge_profiler ();
949 total_num_blocks
= 0;
951 total_num_edges_instrumented
= 0;
952 total_num_blocks_created
= 0;
953 total_num_passes
= 0;
954 total_num_times_called
= 0;
955 total_num_branches
= 0;
956 total_num_never_executed
= 0;
957 for (i
= 0; i
< 20; i
++)
958 total_hist_br_prob
[i
] = 0;
961 /* Performs file-level cleanup after branch-prob processing
967 if (flag_test_coverage
)
973 if (flag_branch_probabilities
)
978 /* This seems slightly dangerous, as it presumes the EOF
979 flag will not be set until an attempt is made to read
980 past the end of the file. */
982 warning (".da file contents exhausted too early\n");
983 /* Should be at end of file now. */
984 if (__read_long (&temp
, da_file
, 8) == 0)
985 warning (".da file contents not exhausted\n");
992 fprintf (rtl_dump_file
, "\n");
993 fprintf (rtl_dump_file
, "Total number of blocks: %d\n",
995 fprintf (rtl_dump_file
, "Total number of edges: %d\n", total_num_edges
);
996 fprintf (rtl_dump_file
, "Total number of instrumented edges: %d\n",
997 total_num_edges_instrumented
);
998 fprintf (rtl_dump_file
, "Total number of blocks created: %d\n",
999 total_num_blocks_created
);
1000 fprintf (rtl_dump_file
, "Total number of graph solution passes: %d\n",
1002 if (total_num_times_called
!= 0)
1003 fprintf (rtl_dump_file
, "Average number of graph solution passes: %d\n",
1004 (total_num_passes
+ (total_num_times_called
>> 1))
1005 / total_num_times_called
);
1006 fprintf (rtl_dump_file
, "Total number of branches: %d\n",
1007 total_num_branches
);
1008 fprintf (rtl_dump_file
, "Total number of branches never executed: %d\n",
1009 total_num_never_executed
);
1010 if (total_num_branches
)
1014 for (i
= 0; i
< 10; i
++)
1015 fprintf (rtl_dump_file
, "%d%% branches in range %d-%d%%\n",
1016 (total_hist_br_prob
[i
] + total_hist_br_prob
[19-i
]) * 100
1017 / total_num_branches
, 5*i
, 5*i
+5);
1022 /* The label used by the edge profiling code. */
1024 static rtx profiler_label
;
1026 /* Initialize the profiler_label. */
1029 init_edge_profiler ()
1031 /* Generate and save a copy of this so it can be shared. */
1032 char *name
= ggc_alloc_string (NULL
, 20);
1033 ASM_GENERATE_INTERNAL_LABEL (name
, "LPBX", 2);
1034 profiler_label
= gen_rtx_SYMBOL_REF (Pmode
, name
);
1035 ggc_add_rtx_root (&profiler_label
, 1);
1038 /* Output instructions as RTL to increment the edge execution count. */
1041 gen_edge_profiler (edgeno
)
1044 enum machine_mode mode
= mode_for_size (LONG_TYPE_SIZE
, MODE_INT
, 0);
1050 tmp
= force_reg (Pmode
, profiler_label
);
1051 tmp
= plus_constant (tmp
, LONG_TYPE_SIZE
/ BITS_PER_UNIT
* edgeno
);
1052 mem_ref
= validize_mem (gen_rtx_MEM (mode
, tmp
));
1054 tmp
= expand_binop (mode
, add_optab
, mem_ref
, const1_rtx
,
1055 mem_ref
, 0, OPTAB_WIDEN
);
1058 emit_move_insn (copy_rtx (mem_ref
), tmp
);
1060 sequence
= gen_sequence ();
1065 /* Output code for a constructor that will invoke __bb_init_func, if
1066 this has not already been done. */
1069 output_func_start_profiler ()
1071 tree fnname
, fndecl
;
1072 char *name
, *cfnname
;
1074 enum machine_mode mode
= mode_for_size (LONG_TYPE_SIZE
, MODE_INT
, 0);
1075 int save_flag_inline_functions
= flag_inline_functions
;
1076 int save_flag_test_coverage
= flag_test_coverage
;
1077 int save_profile_arc_flag
= profile_arc_flag
;
1078 int save_flag_branch_probabilities
= flag_branch_probabilities
;
1080 /* It's either already been output, or we don't need it because we're
1081 not doing profile-edges. */
1082 if (! need_func_profiler
)
1085 need_func_profiler
= 0;
1087 /* Synthesize a constructor function to invoke __bb_init_func with a
1088 pointer to this object file's profile block. */
1090 /* Try and make a unique name given the "file function name".
1092 And no, I don't like this either. */
1094 fnname
= get_file_function_name ('I');
1095 cfnname
= IDENTIFIER_POINTER (fnname
);
1096 name
= xmalloc (strlen (cfnname
) + 5);
1097 sprintf (name
, "%sGCOV",cfnname
);
1098 fnname
= get_identifier (name
);
1101 fndecl
= build_decl (FUNCTION_DECL
, fnname
,
1102 build_function_type (void_type_node
, NULL_TREE
));
1103 DECL_EXTERNAL (fndecl
) = 0;
1105 #if defined(ASM_OUTPUT_CONSTRUCTOR) && defined(ASM_OUTPUT_DESTRUCTOR)
1106 /* It can be a static function as long as collect2 does not have
1107 to scan the object file to find its ctor/dtor routine. */
1108 TREE_PUBLIC (fndecl
) = 0;
1110 TREE_PUBLIC (fndecl
) = 1;
1113 DECL_ASSEMBLER_NAME (fndecl
) = fnname
;
1114 DECL_RESULT (fndecl
) = build_decl (RESULT_DECL
, NULL_TREE
, void_type_node
);
1116 fndecl
= pushdecl (fndecl
);
1117 rest_of_decl_compilation (fndecl
, 0, 1, 0);
1118 announce_function (fndecl
);
1119 current_function_decl
= fndecl
;
1120 DECL_INITIAL (fndecl
) = error_mark_node
;
1121 temporary_allocation ();
1122 make_function_rtl (fndecl
);
1123 init_function_start (fndecl
, input_filename
, lineno
);
1125 expand_function_start (fndecl
, 0);
1127 /* Actually generate the code to call __bb_init_func. */
1128 name
= ggc_alloc_string (NULL
, 20);
1129 ASM_GENERATE_INTERNAL_LABEL (name
, "LPBX", 0);
1130 table_address
= force_reg (Pmode
, gen_rtx_SYMBOL_REF (Pmode
, name
));
1131 emit_library_call (gen_rtx_SYMBOL_REF
1132 (Pmode
, ggc_alloc_string ("__bb_init_func", 14)), 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
)));