1 /* File format for coverage information
2 Copyright (C) 1996-2017 Free Software Foundation, Inc.
3 Contributed by Bob Manson <manson@cygnus.com>.
4 Completely remangled by Nathan Sidwell <nathan@codesourcery.com>.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 Under Section 7 of GPL version 3, you are granted additional
19 permissions described in the GCC Runtime Library Exception, version
20 3.1, as published by the Free Software Foundation.
22 You should have received a copy of the GNU General Public License and
23 a copy of the GCC Runtime Library Exception along with this program;
24 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
25 <http://www.gnu.org/licenses/>. */
27 /* Routines declared in gcov-io.h. This file should be #included by
28 another source file, after having #included gcov-io.h. */
31 static void gcov_write_block (unsigned);
32 static gcov_unsigned_t
*gcov_write_words (unsigned);
34 static const gcov_unsigned_t
*gcov_read_words (unsigned);
36 static void gcov_allocate (unsigned);
39 /* Optimum number of gcov_unsigned_t's read from or written to disk. */
40 #define GCOV_BLOCK_SIZE (1 << 10)
45 gcov_position_t start
; /* Position of first byte of block */
46 unsigned offset
; /* Read/write position within the block. */
47 unsigned length
; /* Read limit in the block. */
48 unsigned overread
; /* Number of words overread. */
49 int error
; /* < 0 overflow, > 0 disk error. */
50 int mode
; /* < 0 writing, > 0 reading */
52 /* Holds one block plus 4 bytes, thus all coverage reads & writes
53 fit within this buffer and we always can transfer GCOV_BLOCK_SIZE
54 to and from the disk. libgcov never backtracks and only writes 4
56 gcov_unsigned_t buffer
[GCOV_BLOCK_SIZE
+ 1];
58 int endian
; /* Swap endianness. */
59 /* Holds a variable length block, as the compiler can write
60 strings and needs to backtrack. */
62 gcov_unsigned_t
*buffer
;
66 /* Save the current position in the gcov file. */
67 /* We need to expose this function when compiling for gcov-tool. */
74 gcov_nonruntime_assert (gcov_var
.mode
> 0);
75 return gcov_var
.start
+ gcov_var
.offset
;
78 /* Return nonzero if the error flag is set. */
79 /* We need to expose this function when compiling for gcov-tool. */
86 return gcov_var
.file
? gcov_var
.error
: 1;
90 /* Move to beginning of file and initialize for writing. */
91 GCOV_LINKAGE
inline void
97 fseek (gcov_var
.file
, 0L, SEEK_SET
);
101 static inline gcov_unsigned_t
from_file (gcov_unsigned_t value
)
106 value
= (value
>> 16) | (value
<< 16);
107 value
= ((value
& 0xff00ff) << 8) | ((value
>> 8) & 0xff00ff);
113 /* Open a gcov file. NAME is the name of the file to open and MODE
114 indicates whether a new file should be created, or an existing file
115 opened. If MODE is >= 0 an existing file will be opened, if
116 possible, and if MODE is <= 0, a new file will be created. Use
117 MODE=0 to attempt to reopen an existing file and then fall back on
118 creating a new one. If MODE > 0, the file will be opened in
119 read-only mode. Otherwise it will be opened for modification.
120 Return zero on failure, non-zero on success. */
124 gcov_open (const char *name
)
126 gcov_open (const char *name
, int mode
)
133 struct flock s_flock
;
136 s_flock
.l_whence
= SEEK_SET
;
138 s_flock
.l_len
= 0; /* Until EOF. */
139 s_flock
.l_pid
= getpid ();
142 gcov_nonruntime_assert (!gcov_var
.file
);
144 gcov_var
.offset
= gcov_var
.length
= 0;
145 gcov_var
.overread
= -1u;
153 /* Read-only mode - acquire a read-lock. */
154 s_flock
.l_type
= F_RDLCK
;
155 /* pass mode (ignored) for compatibility */
156 fd
= open (name
, O_RDONLY
, S_IRUSR
| S_IWUSR
);
160 /* Write mode - acquire a write-lock. */
161 s_flock
.l_type
= F_WRLCK
;
162 /* Truncate if force new mode. */
163 fd
= open (name
, O_RDWR
| O_CREAT
| (mode
< 0 ? O_TRUNC
: 0), 0666);
168 while (fcntl (fd
, F_SETLKW
, &s_flock
) && errno
== EINTR
)
171 gcov_var
.file
= fdopen (fd
, (mode
> 0) ? "rb" : "r+b");
180 /* Open an existing file. */
181 gcov_var
.file
= fopen (name
, (mode
> 0) ? "rb" : "r+b");
186 /* Create a new file. */
187 gcov_var
.file
= fopen (name
, "w+b");
193 gcov_var
.mode
= mode
? mode
: 1;
195 setbuf (gcov_var
.file
, (char *)0);
200 /* Close the current gcov file. Flushes data to disk. Returns nonzero
201 on failure or error flag set. */
209 if (gcov_var
.offset
&& gcov_var
.mode
< 0)
210 gcov_write_block (gcov_var
.offset
);
212 fclose (gcov_var
.file
);
217 free (gcov_var
.buffer
);
222 return gcov_var
.error
;
226 /* Check if MAGIC is EXPECTED. Use it to determine endianness of the
227 file. Returns +1 for same endian, -1 for other endian and zero for
231 gcov_magic (gcov_unsigned_t magic
, gcov_unsigned_t expected
)
233 if (magic
== expected
)
235 magic
= (magic
>> 16) | (magic
<< 16);
236 magic
= ((magic
& 0xff00ff) << 8) | ((magic
>> 8) & 0xff00ff);
237 if (magic
== expected
)
248 gcov_allocate (unsigned length
)
250 size_t new_size
= gcov_var
.alloc
;
253 new_size
= GCOV_BLOCK_SIZE
;
257 gcov_var
.alloc
= new_size
;
258 gcov_var
.buffer
= XRESIZEVAR (gcov_unsigned_t
, gcov_var
.buffer
, new_size
<< 2);
263 /* Write out the current block, if needs be. */
266 gcov_write_block (unsigned size
)
268 if (fwrite (gcov_var
.buffer
, size
<< 2, 1, gcov_var
.file
) != 1)
270 gcov_var
.start
+= size
;
271 gcov_var
.offset
-= size
;
274 /* Allocate space to write BYTES bytes to the gcov file. Return a
275 pointer to those bytes, or NULL on failure. */
277 static gcov_unsigned_t
*
278 gcov_write_words (unsigned words
)
280 gcov_unsigned_t
*result
;
282 gcov_nonruntime_assert (gcov_var
.mode
< 0);
284 if (gcov_var
.offset
>= GCOV_BLOCK_SIZE
)
286 gcov_write_block (GCOV_BLOCK_SIZE
);
289 memcpy (gcov_var
.buffer
, gcov_var
.buffer
+ GCOV_BLOCK_SIZE
, 4);
293 if (gcov_var
.offset
+ words
> gcov_var
.alloc
)
294 gcov_allocate (gcov_var
.offset
+ words
);
296 result
= &gcov_var
.buffer
[gcov_var
.offset
];
297 gcov_var
.offset
+= words
;
302 /* Write unsigned VALUE to coverage file. Sets error flag
306 gcov_write_unsigned (gcov_unsigned_t value
)
308 gcov_unsigned_t
*buffer
= gcov_write_words (1);
313 /* Write counter VALUE to coverage file. Sets error flag
318 gcov_write_counter (gcov_type value
)
320 gcov_unsigned_t
*buffer
= gcov_write_words (2);
322 buffer
[0] = (gcov_unsigned_t
) value
;
323 if (sizeof (value
) > sizeof (gcov_unsigned_t
))
324 buffer
[1] = (gcov_unsigned_t
) (value
>> 32);
328 #endif /* IN_LIBGCOV */
331 /* Write STRING to coverage file. Sets error flag on file
332 error, overflow flag on overflow */
335 gcov_write_string (const char *string
)
339 gcov_unsigned_t
*buffer
;
343 length
= strlen (string
);
344 alloc
= (length
+ 4) >> 2;
347 buffer
= gcov_write_words (1 + alloc
);
353 buffer
[alloc
] = 0; /* place nul terminators. */
354 memcpy (&buffer
[1], string
, length
);
360 /* Write FILENAME to coverage file. Sets error flag on file
361 error, overflow flag on overflow */
364 gcov_write_filename (const char *filename
)
366 if (profile_abs_path_flag
&& filename
&& filename
[0]
367 && !(IS_DIR_SEPARATOR (filename
[0])
368 #if HAVE_DOS_BASED_FILE_SYSTEM
369 || filename
[1] == ':'
373 char *buf
= getcwd (NULL
, 0);
374 if (buf
!= NULL
&& buf
[0])
376 size_t len
= strlen (buf
);
377 buf
= (char*)xrealloc (buf
, len
+ strlen (filename
) + 2);
378 if (!IS_DIR_SEPARATOR (buf
[len
- 1]))
380 strcat (buf
, filename
);
381 gcov_write_string (buf
);
387 gcov_write_string (filename
);
392 /* Write a tag TAG and reserve space for the record length. Return a
393 value to be used for gcov_write_length. */
395 GCOV_LINKAGE gcov_position_t
396 gcov_write_tag (gcov_unsigned_t tag
)
398 gcov_position_t result
= gcov_var
.start
+ gcov_var
.offset
;
399 gcov_unsigned_t
*buffer
= gcov_write_words (2);
407 /* Write a record length using POSITION, which was returned by
408 gcov_write_tag. The current file position is the end of the
409 record, and is restored before returning. Returns nonzero on
413 gcov_write_length (gcov_position_t position
)
416 gcov_unsigned_t length
;
417 gcov_unsigned_t
*buffer
;
419 gcov_nonruntime_assert (gcov_var
.mode
< 0);
420 gcov_nonruntime_assert (position
+ 2 <= gcov_var
.start
+ gcov_var
.offset
);
421 gcov_nonruntime_assert (position
>= gcov_var
.start
);
422 offset
= position
- gcov_var
.start
;
423 length
= gcov_var
.offset
- offset
- 2;
424 buffer
= (gcov_unsigned_t
*) &gcov_var
.buffer
[offset
];
426 if (gcov_var
.offset
>= GCOV_BLOCK_SIZE
)
427 gcov_write_block (gcov_var
.offset
);
430 #else /* IN_LIBGCOV */
432 /* Write a tag TAG and length LENGTH. */
435 gcov_write_tag_length (gcov_unsigned_t tag
, gcov_unsigned_t length
)
437 gcov_unsigned_t
*buffer
= gcov_write_words (2);
443 /* Write a summary structure to the gcov file. Return nonzero on
447 gcov_write_summary (gcov_unsigned_t tag
, const struct gcov_summary
*summary
)
449 unsigned ix
, h_ix
, bv_ix
, h_cnt
= 0;
450 const struct gcov_ctr_summary
*csum
;
451 unsigned histo_bitvector
[GCOV_HISTOGRAM_BITVECTOR_SIZE
];
453 /* Count number of non-zero histogram entries, and fill in a bit vector
454 of non-zero indices. The histogram is only currently computed for arc
456 for (bv_ix
= 0; bv_ix
< GCOV_HISTOGRAM_BITVECTOR_SIZE
; bv_ix
++)
457 histo_bitvector
[bv_ix
] = 0;
458 csum
= &summary
->ctrs
[GCOV_COUNTER_ARCS
];
459 for (h_ix
= 0; h_ix
< GCOV_HISTOGRAM_SIZE
; h_ix
++)
460 if (csum
->histogram
[h_ix
].num_counters
)
462 histo_bitvector
[h_ix
/ 32] |= 1 << (h_ix
% 32);
465 gcov_write_tag_length (tag
, GCOV_TAG_SUMMARY_LENGTH (h_cnt
));
466 gcov_write_unsigned (summary
->checksum
);
467 for (csum
= summary
->ctrs
, ix
= GCOV_COUNTERS_SUMMABLE
; ix
--; csum
++)
469 gcov_write_unsigned (csum
->num
);
470 gcov_write_unsigned (csum
->runs
);
471 gcov_write_counter (csum
->sum_all
);
472 gcov_write_counter (csum
->run_max
);
473 gcov_write_counter (csum
->sum_max
);
474 if (ix
!= GCOV_COUNTER_ARCS
)
476 for (bv_ix
= 0; bv_ix
< GCOV_HISTOGRAM_BITVECTOR_SIZE
; bv_ix
++)
477 gcov_write_unsigned (0);
480 for (bv_ix
= 0; bv_ix
< GCOV_HISTOGRAM_BITVECTOR_SIZE
; bv_ix
++)
481 gcov_write_unsigned (histo_bitvector
[bv_ix
]);
482 for (h_ix
= 0; h_ix
< GCOV_HISTOGRAM_SIZE
; h_ix
++)
484 if (!csum
->histogram
[h_ix
].num_counters
)
486 gcov_write_unsigned (csum
->histogram
[h_ix
].num_counters
);
487 gcov_write_counter (csum
->histogram
[h_ix
].min_value
);
488 gcov_write_counter (csum
->histogram
[h_ix
].cum_value
);
492 #endif /* IN_LIBGCOV */
496 /* Return a pointer to read BYTES bytes from the gcov file. Returns
497 NULL on failure (read past EOF). */
499 static const gcov_unsigned_t
*
500 gcov_read_words (unsigned words
)
502 const gcov_unsigned_t
*result
;
503 unsigned excess
= gcov_var
.length
- gcov_var
.offset
;
505 if (gcov_var
.mode
<= 0)
510 gcov_var
.start
+= gcov_var
.offset
;
514 memcpy (gcov_var
.buffer
, gcov_var
.buffer
+ gcov_var
.offset
, 4);
516 memmove (gcov_var
.buffer
, gcov_var
.buffer
+ gcov_var
.offset
,
521 gcov_var
.length
= excess
;
523 excess
= GCOV_BLOCK_SIZE
;
525 if (gcov_var
.length
+ words
> gcov_var
.alloc
)
526 gcov_allocate (gcov_var
.length
+ words
);
527 excess
= gcov_var
.alloc
- gcov_var
.length
;
529 excess
= fread (gcov_var
.buffer
+ gcov_var
.length
,
530 1, excess
<< 2, gcov_var
.file
) >> 2;
531 gcov_var
.length
+= excess
;
532 if (gcov_var
.length
< words
)
534 gcov_var
.overread
+= words
- gcov_var
.length
;
539 result
= &gcov_var
.buffer
[gcov_var
.offset
];
540 gcov_var
.offset
+= words
;
544 /* Read unsigned value from a coverage file. Sets error flag on file
545 error, overflow flag on overflow */
547 GCOV_LINKAGE gcov_unsigned_t
548 gcov_read_unsigned (void)
550 gcov_unsigned_t value
;
551 const gcov_unsigned_t
*buffer
= gcov_read_words (1);
555 value
= from_file (buffer
[0]);
559 /* Read counter value from a coverage file. Sets error flag on file
560 error, overflow flag on overflow */
562 GCOV_LINKAGE gcov_type
563 gcov_read_counter (void)
566 const gcov_unsigned_t
*buffer
= gcov_read_words (2);
570 value
= from_file (buffer
[0]);
571 if (sizeof (value
) > sizeof (gcov_unsigned_t
))
572 value
|= ((gcov_type
) from_file (buffer
[1])) << 32;
579 /* We need to expose the below function when compiling for gcov-tool. */
581 #if !IN_LIBGCOV || defined (IN_GCOV_TOOL)
582 /* Read string from coverage file. Returns a pointer to a static
583 buffer, or NULL on empty string. You must copy the string before
584 calling another gcov function. */
586 GCOV_LINKAGE
const char *
587 gcov_read_string (void)
589 unsigned length
= gcov_read_unsigned ();
594 return (const char *) gcov_read_words (length
);
599 gcov_read_summary (struct gcov_summary
*summary
)
601 unsigned ix
, h_ix
, bv_ix
, h_cnt
= 0;
602 struct gcov_ctr_summary
*csum
;
603 unsigned histo_bitvector
[GCOV_HISTOGRAM_BITVECTOR_SIZE
];
604 unsigned cur_bitvector
;
606 summary
->checksum
= gcov_read_unsigned ();
607 for (csum
= summary
->ctrs
, ix
= GCOV_COUNTERS_SUMMABLE
; ix
--; csum
++)
609 csum
->num
= gcov_read_unsigned ();
610 csum
->runs
= gcov_read_unsigned ();
611 csum
->sum_all
= gcov_read_counter ();
612 csum
->run_max
= gcov_read_counter ();
613 csum
->sum_max
= gcov_read_counter ();
614 memset (csum
->histogram
, 0,
615 sizeof (gcov_bucket_type
) * GCOV_HISTOGRAM_SIZE
);
616 for (bv_ix
= 0; bv_ix
< GCOV_HISTOGRAM_BITVECTOR_SIZE
; bv_ix
++)
618 histo_bitvector
[bv_ix
] = gcov_read_unsigned ();
620 /* When building libgcov we don't include system.h, which includes
621 hwint.h (where popcount_hwi is declared). However, libgcov.a
622 is built by the bootstrapped compiler and therefore the builtins
623 are always available. */
624 h_cnt
+= __builtin_popcount (histo_bitvector
[bv_ix
]);
626 h_cnt
+= popcount_hwi (histo_bitvector
[bv_ix
]);
634 /* Find the index corresponding to the next entry we will read in.
635 First find the next non-zero bitvector and re-initialize
636 the histogram index accordingly, then right shift and increment
637 the index until we find a set bit. */
638 while (!cur_bitvector
)
641 if (bv_ix
>= GCOV_HISTOGRAM_BITVECTOR_SIZE
)
642 gcov_error ("corrupted profile info: summary histogram "
643 "bitvector is corrupt");
644 cur_bitvector
= histo_bitvector
[bv_ix
++];
646 while (!(cur_bitvector
& 0x1))
651 if (h_ix
>= GCOV_HISTOGRAM_SIZE
)
652 gcov_error ("corrupted profile info: summary histogram "
655 csum
->histogram
[h_ix
].num_counters
= gcov_read_unsigned ();
656 csum
->histogram
[h_ix
].min_value
= gcov_read_counter ();
657 csum
->histogram
[h_ix
].cum_value
= gcov_read_counter ();
658 /* Shift off the index we are done with and increment to the
659 corresponding next histogram entry. */
666 /* We need to expose the below function when compiling for gcov-tool. */
668 #if !IN_LIBGCOV || defined (IN_GCOV_TOOL)
669 /* Reset to a known position. BASE should have been obtained from
670 gcov_position, LENGTH should be a record length. */
673 gcov_sync (gcov_position_t base
, gcov_unsigned_t length
)
675 gcov_nonruntime_assert (gcov_var
.mode
> 0);
677 if (base
- gcov_var
.start
<= gcov_var
.length
)
678 gcov_var
.offset
= base
- gcov_var
.start
;
681 gcov_var
.offset
= gcov_var
.length
= 0;
682 fseek (gcov_var
.file
, base
<< 2, SEEK_SET
);
683 gcov_var
.start
= ftell (gcov_var
.file
) >> 2;
689 /* Move to a given position in a gcov file. */
692 gcov_seek (gcov_position_t base
)
695 gcov_write_block (gcov_var
.offset
);
696 fseek (gcov_var
.file
, base
<< 2, SEEK_SET
);
697 gcov_var
.start
= ftell (gcov_var
.file
) >> 2;
702 /* Return the modification time of the current gcov file. */
709 if (fstat (fileno (gcov_var
.file
), &status
))
712 return status
.st_mtime
;
717 /* Determine the index into histogram for VALUE. */
722 GCOV_LINKAGE
unsigned
724 gcov_histo_index (gcov_type value
)
726 gcov_type_unsigned v
= (gcov_type_unsigned
)value
;
728 unsigned prev2bits
= 0;
730 /* Find index into log2 scale histogram, where each of the log2
731 sized buckets is divided into 4 linear sub-buckets for better
732 focus in the higher buckets. */
734 /* Find the place of the most-significant bit set. */
738 /* When building libgcov we don't include system.h, which includes
739 hwint.h (where floor_log2 is declared). However, libgcov.a
740 is built by the bootstrapped compiler and therefore the builtins
741 are always available. */
742 r
= sizeof (long long) * __CHAR_BIT__
- 1 - __builtin_clzll (v
);
744 /* We use floor_log2 from hwint.c, which takes a HOST_WIDE_INT
745 that is 64 bits and gcov_type_unsigned is 64 bits. */
750 /* If at most the 2 least significant bits are set (value is
751 0 - 3) then that value is our index into the lowest set of
754 return (unsigned)value
;
756 gcov_nonruntime_assert (r
< 64);
758 /* Find the two next most significant bits to determine which
759 of the four linear sub-buckets to select. */
760 prev2bits
= (v
>> (r
- 2)) & 0x3;
761 /* Finally, compose the final bucket index from the log2 index and
762 the next 2 bits. The minimum r value at this point is 2 since we
763 returned above if r was 2 or more, so the minimum bucket at this
765 return (r
- 1) * 4 + prev2bits
;
768 /* Merge SRC_HISTO into TGT_HISTO. The counters are assumed to be in
769 the same relative order in both histograms, and are matched up
770 and merged in reverse order. Each counter is assigned an equal portion of
771 its entry's original cumulative counter value when computing the
772 new merged cum_value. */
774 static void gcov_histogram_merge (gcov_bucket_type
*tgt_histo
,
775 gcov_bucket_type
*src_histo
)
777 int src_i
, tgt_i
, tmp_i
= 0;
778 unsigned src_num
, tgt_num
, merge_num
;
779 gcov_type src_cum
, tgt_cum
, merge_src_cum
, merge_tgt_cum
, merge_cum
;
781 gcov_bucket_type tmp_histo
[GCOV_HISTOGRAM_SIZE
];
784 memset (tmp_histo
, 0, sizeof (gcov_bucket_type
) * GCOV_HISTOGRAM_SIZE
);
786 /* Assume that the counters are in the same relative order in both
787 histograms. Walk the histograms from largest to smallest entry,
788 matching up and combining counters in order. */
791 src_i
= GCOV_HISTOGRAM_SIZE
- 1;
792 for (tgt_i
= GCOV_HISTOGRAM_SIZE
- 1; tgt_i
>= 0 && !src_done
; tgt_i
--)
794 tgt_num
= tgt_histo
[tgt_i
].num_counters
;
795 tgt_cum
= tgt_histo
[tgt_i
].cum_value
;
796 /* Keep going until all of the target histogram's counters at this
797 position have been matched and merged with counters from the
799 while (tgt_num
> 0 && !src_done
)
801 /* If this is either the first time through this loop or we just
802 exhausted the previous non-zero source histogram entry, look
803 for the next non-zero source histogram entry. */
806 /* Locate the next non-zero entry. */
807 while (src_i
>= 0 && !src_histo
[src_i
].num_counters
)
809 /* If source histogram has fewer counters, then just copy over the
810 remaining target counters and quit. */
813 tmp_histo
[tgt_i
].num_counters
+= tgt_num
;
814 tmp_histo
[tgt_i
].cum_value
+= tgt_cum
;
815 if (!tmp_histo
[tgt_i
].min_value
||
816 tgt_histo
[tgt_i
].min_value
< tmp_histo
[tgt_i
].min_value
)
817 tmp_histo
[tgt_i
].min_value
= tgt_histo
[tgt_i
].min_value
;
820 tmp_histo
[tgt_i
].num_counters
821 += tgt_histo
[tgt_i
].num_counters
;
822 tmp_histo
[tgt_i
].cum_value
+= tgt_histo
[tgt_i
].cum_value
;
823 if (!tmp_histo
[tgt_i
].min_value
||
824 tgt_histo
[tgt_i
].min_value
825 < tmp_histo
[tgt_i
].min_value
)
826 tmp_histo
[tgt_i
].min_value
= tgt_histo
[tgt_i
].min_value
;
833 src_num
= src_histo
[src_i
].num_counters
;
834 src_cum
= src_histo
[src_i
].cum_value
;
837 /* The number of counters to merge on this pass is the minimum
838 of the remaining counters from the current target and source
839 histogram entries. */
841 if (src_num
< merge_num
)
844 /* The merged min_value is the sum of the min_values from target
846 merge_min
= tgt_histo
[tgt_i
].min_value
+ src_histo
[src_i
].min_value
;
848 /* Compute the portion of source and target entries' cum_value
849 that will be apportioned to the counters being merged.
850 The total remaining cum_value from each entry is divided
851 equally among the counters from that histogram entry if we
852 are not merging all of them. */
853 merge_src_cum
= src_cum
;
854 if (merge_num
< src_num
)
855 merge_src_cum
= merge_num
* src_cum
/ src_num
;
856 merge_tgt_cum
= tgt_cum
;
857 if (merge_num
< tgt_num
)
858 merge_tgt_cum
= merge_num
* tgt_cum
/ tgt_num
;
859 /* The merged cum_value is the sum of the source and target
861 merge_cum
= merge_src_cum
+ merge_tgt_cum
;
863 /* Update the remaining number of counters and cum_value left
864 to be merged from this source and target entry. */
865 src_cum
-= merge_src_cum
;
866 tgt_cum
-= merge_tgt_cum
;
867 src_num
-= merge_num
;
868 tgt_num
-= merge_num
;
870 /* The merged counters get placed in the new merged histogram
871 at the entry for the merged min_value. */
872 tmp_i
= gcov_histo_index (merge_min
);
873 gcov_nonruntime_assert (tmp_i
< GCOV_HISTOGRAM_SIZE
);
874 tmp_histo
[tmp_i
].num_counters
+= merge_num
;
875 tmp_histo
[tmp_i
].cum_value
+= merge_cum
;
876 if (!tmp_histo
[tmp_i
].min_value
||
877 merge_min
< tmp_histo
[tmp_i
].min_value
)
878 tmp_histo
[tmp_i
].min_value
= merge_min
;
880 /* Ensure the search for the next non-zero src_histo entry starts
881 at the next smallest histogram bucket. */
887 gcov_nonruntime_assert (tgt_i
< 0);
889 /* In the case where there were more counters in the source histogram,
890 accumulate the remaining unmerged cumulative counter values. Add
891 those to the smallest non-zero target histogram entry. Otherwise,
892 the total cumulative counter values in the histogram will be smaller
893 than the sum_all stored in the summary, which will complicate
894 computing the working set information from the histogram later on. */
899 src_cum
+= src_histo
[src_i
].cum_value
;
902 /* At this point, tmp_i should be the smallest non-zero entry in the
904 gcov_nonruntime_assert (tmp_i
>= 0 && tmp_i
< GCOV_HISTOGRAM_SIZE
905 && tmp_histo
[tmp_i
].num_counters
> 0);
906 tmp_histo
[tmp_i
].cum_value
+= src_cum
;
908 /* Finally, copy the merged histogram into tgt_histo. */
909 memcpy (tgt_histo
, tmp_histo
,
910 sizeof (gcov_bucket_type
) * GCOV_HISTOGRAM_SIZE
);
912 #endif /* !IN_GCOV */
914 /* This is used by gcov-dump (IN_GCOV == -1) and in the compiler
915 (!IN_GCOV && !IN_LIBGCOV). */
916 #if IN_GCOV <= 0 && !IN_LIBGCOV
917 /* Compute the working set information from the counter histogram in
918 the profile summary. This is an array of information corresponding to a
919 range of percentages of the total execution count (sum_all), and includes
920 the number of counters required to cover that working set percentage and
921 the minimum counter value in that working set. */
924 compute_working_sets (const struct gcov_ctr_summary
*summary
,
925 gcov_working_set_t
*gcov_working_sets
)
927 gcov_type working_set_cum_values
[NUM_GCOV_WORKING_SETS
];
928 gcov_type ws_cum_hotness_incr
;
929 gcov_type cum
, tmp_cum
;
930 const gcov_bucket_type
*histo_bucket
;
931 unsigned ws_ix
, c_num
, count
;
934 /* Compute the amount of sum_all that the cumulative hotness grows
935 by in each successive working set entry, which depends on the
936 number of working set entries. */
937 ws_cum_hotness_incr
= summary
->sum_all
/ NUM_GCOV_WORKING_SETS
;
939 /* Next fill in an array of the cumulative hotness values corresponding
940 to each working set summary entry we are going to compute below.
941 Skip 0% statistics, which can be extrapolated from the
942 rest of the summary data. */
943 cum
= ws_cum_hotness_incr
;
944 for (ws_ix
= 0; ws_ix
< NUM_GCOV_WORKING_SETS
;
945 ws_ix
++, cum
+= ws_cum_hotness_incr
)
946 working_set_cum_values
[ws_ix
] = cum
;
947 /* The last summary entry is reserved for (roughly) 99.9% of the
948 working set. Divide by 1024 so it becomes a shift, which gives
949 almost exactly 99.9%. */
950 working_set_cum_values
[NUM_GCOV_WORKING_SETS
-1]
951 = summary
->sum_all
- summary
->sum_all
/1024;
953 /* Next, walk through the histogram in decending order of hotness
954 and compute the statistics for the working set summary array.
955 As histogram entries are accumulated, we check to see which
956 working set entries have had their expected cum_value reached
957 and fill them in, walking the working set entries in increasing
958 size of cum_value. */
959 ws_ix
= 0; /* The current entry into the working set array. */
960 cum
= 0; /* The current accumulated counter sum. */
961 count
= 0; /* The current accumulated count of block counters. */
962 for (h_ix
= GCOV_HISTOGRAM_SIZE
- 1;
963 h_ix
>= 0 && ws_ix
< NUM_GCOV_WORKING_SETS
; h_ix
--)
965 histo_bucket
= &summary
->histogram
[h_ix
];
967 /* If we haven't reached the required cumulative counter value for
968 the current working set percentage, simply accumulate this histogram
969 entry into the running sums and continue to the next histogram
971 if (cum
+ histo_bucket
->cum_value
< working_set_cum_values
[ws_ix
])
973 cum
+= histo_bucket
->cum_value
;
974 count
+= histo_bucket
->num_counters
;
978 /* If adding the current histogram entry's cumulative counter value
979 causes us to exceed the current working set size, then estimate
980 how many of this histogram entry's counter values are required to
981 reach the working set size, and fill in working set entries
982 as we reach their expected cumulative value. */
983 for (c_num
= 0, tmp_cum
= cum
;
984 c_num
< histo_bucket
->num_counters
&& ws_ix
< NUM_GCOV_WORKING_SETS
;
988 /* If we haven't reached the last histogram entry counter, add
989 in the minimum value again. This will underestimate the
990 cumulative sum so far, because many of the counter values in this
991 entry may have been larger than the minimum. We could add in the
992 average value every time, but that would require an expensive
994 if (c_num
+ 1 < histo_bucket
->num_counters
)
995 tmp_cum
+= histo_bucket
->min_value
;
996 /* If we have reached the last histogram entry counter, then add
997 in the entire cumulative value. */
999 tmp_cum
= cum
+ histo_bucket
->cum_value
;
1001 /* Next walk through successive working set entries and fill in
1002 the statistics for any whose size we have reached by accumulating
1003 this histogram counter. */
1004 while (ws_ix
< NUM_GCOV_WORKING_SETS
1005 && tmp_cum
>= working_set_cum_values
[ws_ix
])
1007 gcov_working_sets
[ws_ix
].num_counters
= count
;
1008 gcov_working_sets
[ws_ix
].min_counter
1009 = histo_bucket
->min_value
;
1013 /* Finally, update the running cumulative value since we were
1014 using a temporary above. */
1015 cum
+= histo_bucket
->cum_value
;
1017 gcov_nonruntime_assert (ws_ix
== NUM_GCOV_WORKING_SETS
);
1019 #endif /* IN_GCOV <= 0 && !IN_LIBGCOV */