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>.
5
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify it under
9the terms of the GNU General Public License as published by the Free
10Software Foundation; either version 3, or (at your option) any later
11version.
12
13GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14WARRANTY; without even the implied warranty of MERCHANTABILITY or
15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16for more details.
17
18Under Section 7 of GPL version 3, you are granted additional
19permissions described in the GCC Runtime Library Exception, version
203.1, as published by the Free Software Foundation.
21
22You should have received a copy of the GNU General Public License and
23a copy of the GCC Runtime Library Exception along with this program;
24see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
25<http://www.gnu.org/licenses/>. */
26
27/* Routines declared in gcov-io.h. This file should be #included by
28 another source file, after having #included gcov-io.h. */
29
30#if !IN_GCOV
31static void gcov_write_block (unsigned);
32static gcov_unsigned_t *gcov_write_words (unsigned);
33#endif
34static const gcov_unsigned_t *gcov_read_words (unsigned);
35#if !IN_LIBGCOV
36static void gcov_allocate (unsigned);
37#endif
38
39/* Optimum number of gcov_unsigned_t's read from or written to disk. */
40#define GCOV_BLOCK_SIZE (1 << 10)
41
42struct gcov_var
43{
44 FILE *file;
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 */
51#if IN_LIBGCOV
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
55 or 8 byte objects. */
56 gcov_unsigned_t buffer[GCOV_BLOCK_SIZE + 1];
57#else
58 int endian; /* Swap endianness. */
59 /* Holds a variable length block, as the compiler can write
60 strings and needs to backtrack. */
61 size_t alloc;
62 gcov_unsigned_t *buffer;
63#endif
64} gcov_var;
65
66/* Save the current position in the gcov file. */
67/* We need to expose this function when compiling for gcov-tool. */
68#ifndef IN_GCOV_TOOL
69static inline
70#endif
71gcov_position_t
72gcov_position (void)
73{
74 gcov_nonruntime_assert (gcov_var.mode > 0);
75 return gcov_var.start + gcov_var.offset;
76}
77
78/* Return nonzero if the error flag is set. */
79/* We need to expose this function when compiling for gcov-tool. */
80#ifndef IN_GCOV_TOOL
81static inline
82#endif
83int
84gcov_is_error (void)
85{
86 return gcov_var.file ? gcov_var.error : 1;
87}
88
89#if IN_LIBGCOV
90/* Move to beginning of file and initialize for writing. */
91GCOV_LINKAGE inline void
92gcov_rewrite (void)
93{
94 gcov_var.mode = -1;
95 gcov_var.start = 0;
96 gcov_var.offset = 0;
97 fseek (gcov_var.file, 0L, SEEK_SET);
98}
99#endif
100
101static inline gcov_unsigned_t from_file (gcov_unsigned_t value)
102{
103#if !IN_LIBGCOV
104 if (gcov_var.endian)
105 {
106 value = (value >> 16) | (value << 16);
107 value = ((value & 0xff00ff) << 8) | ((value >> 8) & 0xff00ff);
108 }
109#endif
110 return value;
111}
112
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. */
121
122GCOV_LINKAGE int
123#if IN_LIBGCOV
124gcov_open (const char *name)
125#else
126gcov_open (const char *name, int mode)
127#endif
128{
129#if IN_LIBGCOV
130 int mode = 0;
131#endif
132#if GCOV_LOCKED
133 struct flock s_flock;
134 int fd;
135
136 s_flock.l_whence = SEEK_SET;
137 s_flock.l_start = 0;
138 s_flock.l_len = 0; /* Until EOF. */
139 s_flock.l_pid = getpid ();
140#endif
141
142 gcov_nonruntime_assert (!gcov_var.file);
143 gcov_var.start = 0;
144 gcov_var.offset = gcov_var.length = 0;
145 gcov_var.overread = -1u;
146 gcov_var.error = 0;
147#if !IN_LIBGCOV
148 gcov_var.endian = 0;
149#endif
150#if GCOV_LOCKED
151 if (mode > 0)
152 {
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);
157 }
158 else
159 {
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);
164 }
165 if (fd < 0)
166 return 0;
167
168 while (fcntl (fd, F_SETLKW, &s_flock) && errno == EINTR)
169 continue;
170
171 gcov_var.file = fdopen (fd, (mode > 0) ? "rb" : "r+b");
172
173 if (!gcov_var.file)
174 {
175 close (fd);
176 return 0;
177 }
178#else
179 if (mode >= 0)
180 /* Open an existing file. */
181 gcov_var.file = fopen (name, (mode > 0) ? "rb" : "r+b");
182
183 if (gcov_var.file)
184 mode = 1;
185 else if (mode <= 0)
186 /* Create a new file. */
187 gcov_var.file = fopen (name, "w+b");
188
189 if (!gcov_var.file)
190 return 0;
191#endif
192
193 gcov_var.mode = mode ? mode : 1;
194
195 setbuf (gcov_var.file, (char *)0);
196
197 return 1;
198}
199
200/* Close the current gcov file. Flushes data to disk. Returns nonzero
201 on failure or error flag set. */
202
203GCOV_LINKAGE int
204gcov_close (void)
205{
206 if (gcov_var.file)
207 {
208#if !IN_GCOV
209 if (gcov_var.offset && gcov_var.mode < 0)
210 gcov_write_block (gcov_var.offset);
211#endif
212 fclose (gcov_var.file);
213 gcov_var.file = 0;
214 gcov_var.length = 0;
215 }
216#if !IN_LIBGCOV
217 free (gcov_var.buffer);
218 gcov_var.alloc = 0;
219 gcov_var.buffer = 0;
220#endif
221 gcov_var.mode = 0;
222 return gcov_var.error;
223}
224
225#if !IN_LIBGCOV
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
228 not EXPECTED. */
229
230GCOV_LINKAGE int
231gcov_magic (gcov_unsigned_t magic, gcov_unsigned_t expected)
232{
233 if (magic == expected)
234 return 1;
235 magic = (magic >> 16) | (magic << 16);
236 magic = ((magic & 0xff00ff) << 8) | ((magic >> 8) & 0xff00ff);
237 if (magic == expected)
238 {
239 gcov_var.endian = 1;
240 return -1;
241 }
242 return 0;
243}
244#endif
245
246#if !IN_LIBGCOV
247static void
248gcov_allocate (unsigned length)
249{
250 size_t new_size = gcov_var.alloc;
251
252 if (!new_size)
253 new_size = GCOV_BLOCK_SIZE;
254 new_size += length;
255 new_size *= 2;
256
257 gcov_var.alloc = new_size;
258 gcov_var.buffer = XRESIZEVAR (gcov_unsigned_t, gcov_var.buffer, new_size << 2);
259}
260#endif
261
262#if !IN_GCOV
263/* Write out the current block, if needs be. */
264
265static void
266gcov_write_block (unsigned size)
267{
268 if (fwrite (gcov_var.buffer, size << 2, 1, gcov_var.file) != 1)
269 gcov_var.error = 1;
270 gcov_var.start += size;
271 gcov_var.offset -= size;
272}
273
274/* Allocate space to write BYTES bytes to the gcov file. Return a
275 pointer to those bytes, or NULL on failure. */
276
277static gcov_unsigned_t *
278gcov_write_words (unsigned words)
279{
280 gcov_unsigned_t *result;
281
282 gcov_nonruntime_assert (gcov_var.mode < 0);
283#if IN_LIBGCOV
284 if (gcov_var.offset >= GCOV_BLOCK_SIZE)
285 {
286 gcov_write_block (GCOV_BLOCK_SIZE);
287 if (gcov_var.offset)
288 {
289 memcpy (gcov_var.buffer, gcov_var.buffer + GCOV_BLOCK_SIZE, 4);
290 }
291 }
292#else
293 if (gcov_var.offset + words > gcov_var.alloc)
294 gcov_allocate (gcov_var.offset + words);
295#endif
296 result = &gcov_var.buffer[gcov_var.offset];
297 gcov_var.offset += words;
298
299 return result;
300}
301
302/* Write unsigned VALUE to coverage file. Sets error flag
303 appropriately. */
304
305GCOV_LINKAGE void
306gcov_write_unsigned (gcov_unsigned_t value)
307{
308 gcov_unsigned_t *buffer = gcov_write_words (1);
309
310 buffer[0] = value;
311}
312
313/* Write counter VALUE to coverage file. Sets error flag
314 appropriately. */
315
316#if IN_LIBGCOV
317GCOV_LINKAGE void
318gcov_write_counter (gcov_type value)
319{
320 gcov_unsigned_t *buffer = gcov_write_words (2);
321
322 buffer[0] = (gcov_unsigned_t) value;
323 if (sizeof (value) > sizeof (gcov_unsigned_t))
324 buffer[1] = (gcov_unsigned_t) (value >> 32);
325 else
326 buffer[1] = 0;
327}
328#endif /* IN_LIBGCOV */
329
330#if !IN_LIBGCOV
331/* Write STRING to coverage file. Sets error flag on file
332 error, overflow flag on overflow */
333
334GCOV_LINKAGE void
335gcov_write_string (const char *string)
336{
337 unsigned length = 0;
338 unsigned alloc = 0;
339 gcov_unsigned_t *buffer;
340
341 if (string)
342 {
343 length = strlen (string);
344 alloc = (length + 4) >> 2;
345 }
346
347 buffer = gcov_write_words (1 + alloc);
348
349 buffer[0] = alloc;
350
351 if (alloc > 0)
352 {
353 buffer[alloc] = 0; /* place nul terminators. */
354 memcpy (&buffer[1], string, length);
355 }
356}
357#endif
358
359#if !IN_LIBGCOV
360/* Write FILENAME to coverage file. Sets error flag on file
361 error, overflow flag on overflow */
362
363GCOV_LINKAGE void
364gcov_write_filename (const char *filename)
365{
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] == ':'
370#endif
371 ))
372 {
373 char *buf = getcwd (NULL, 0);
374 if (buf != NULL && buf[0])
375 {
376 size_t len = strlen (buf);
377 buf = (char*)xrealloc (buf, len + strlen (filename) + 2);
378 if (!IS_DIR_SEPARATOR (buf[len - 1]))
379 strcat (buf, "/");
380 strcat (buf, filename);
381 gcov_write_string (buf);
382 free (buf);
383 return;
384 }
385 }
386
387 gcov_write_string (filename);
388}
389#endif
390
391#if !IN_LIBGCOV
392/* Write a tag TAG and reserve space for the record length. Return a
393 value to be used for gcov_write_length. */
394
395GCOV_LINKAGE gcov_position_t
396gcov_write_tag (gcov_unsigned_t tag)
397{
398 gcov_position_t result = gcov_var.start + gcov_var.offset;
399 gcov_unsigned_t *buffer = gcov_write_words (2);
400
401 buffer[0] = tag;
402 buffer[1] = 0;
403
404 return result;
405}
406
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
410 overflow. */
411
412GCOV_LINKAGE void
413gcov_write_length (gcov_position_t position)
414{
415 unsigned offset;
416 gcov_unsigned_t length;
417 gcov_unsigned_t *buffer;
418
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];
425 buffer[1] = length;
426 if (gcov_var.offset >= GCOV_BLOCK_SIZE)
427 gcov_write_block (gcov_var.offset);
428}
429
430#else /* IN_LIBGCOV */
431
432/* Write a tag TAG and length LENGTH. */
433
434GCOV_LINKAGE void
435gcov_write_tag_length (gcov_unsigned_t tag, gcov_unsigned_t length)
436{
437 gcov_unsigned_t *buffer = gcov_write_words (2);
438
439 buffer[0] = tag;
440 buffer[1] = length;
441}
442
443/* Write a summary structure to the gcov file. Return nonzero on
444 overflow. */
445
446GCOV_LINKAGE void
447gcov_write_summary (gcov_unsigned_t tag, const struct gcov_summary *summary)
448{
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];
452
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
455 counters. */
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)
461 {
462 histo_bitvector[h_ix / 32] |= 1 << (h_ix % 32);
463 h_cnt++;
464 }
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++)
468 {
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)
475 {
476 for (bv_ix = 0; bv_ix < GCOV_HISTOGRAM_BITVECTOR_SIZE; bv_ix++)
477 gcov_write_unsigned (0);
478 continue;
479 }
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++)
483 {
484 if (!csum->histogram[h_ix].num_counters)
485 continue;
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);
489 }
490 }
491}
492#endif /* IN_LIBGCOV */
493
494#endif /*!IN_GCOV */
495
496/* Return a pointer to read BYTES bytes from the gcov file. Returns
497 NULL on failure (read past EOF). */
498
499static const gcov_unsigned_t *
500gcov_read_words (unsigned words)
501{
502 const gcov_unsigned_t *result;
503 unsigned excess = gcov_var.length - gcov_var.offset;
504
505 if (gcov_var.mode <= 0)
506 return NULL;
507
508 if (excess < words)
509 {
510 gcov_var.start += gcov_var.offset;
511 if (excess)
512 {
513#if IN_LIBGCOV
514 memcpy (gcov_var.buffer, gcov_var.buffer + gcov_var.offset, 4);
515#else
516 memmove (gcov_var.buffer, gcov_var.buffer + gcov_var.offset,
517 excess * 4);
518#endif
519 }
520 gcov_var.offset = 0;
521 gcov_var.length = excess;
522#if IN_LIBGCOV
523 excess = GCOV_BLOCK_SIZE;
524#else
525 if (gcov_var.length + words > gcov_var.alloc)
526 gcov_allocate (gcov_var.length + words);
527 excess = gcov_var.alloc - gcov_var.length;
528#endif
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)
533 {
534 gcov_var.overread += words - gcov_var.length;
535 gcov_var.length = 0;
536 return 0;
537 }
538 }
539 result = &gcov_var.buffer[gcov_var.offset];
540 gcov_var.offset += words;
541 return result;
542}
543
544/* Read unsigned value from a coverage file. Sets error flag on file
545 error, overflow flag on overflow */
546
547GCOV_LINKAGE gcov_unsigned_t
548gcov_read_unsigned (void)
549{
550 gcov_unsigned_t value;
551 const gcov_unsigned_t *buffer = gcov_read_words (1);
552
553 if (!buffer)
554 return 0;
555 value = from_file (buffer[0]);
556 return value;
557}
558
559/* Read counter value from a coverage file. Sets error flag on file
560 error, overflow flag on overflow */
561
562GCOV_LINKAGE gcov_type
563gcov_read_counter (void)
564{
565 gcov_type value;
566 const gcov_unsigned_t *buffer = gcov_read_words (2);
567
568 if (!buffer)
569 return 0;
570 value = from_file (buffer[0]);
571 if (sizeof (value) > sizeof (gcov_unsigned_t))
572 value |= ((gcov_type) from_file (buffer[1])) << 32;
573 else if (buffer[1])
574 gcov_var.error = -1;
575
576 return value;
577}
578
579/* We need to expose the below function when compiling for gcov-tool. */
580
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. */
585
586GCOV_LINKAGE const char *
587gcov_read_string (void)
588{
589 unsigned length = gcov_read_unsigned ();
590
591 if (!length)
592 return 0;
593
594 return (const char *) gcov_read_words (length);
595}
596#endif
597
598GCOV_LINKAGE void
599gcov_read_summary (struct gcov_summary *summary)
600{
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;
605
606 summary->checksum = gcov_read_unsigned ();
607 for (csum = summary->ctrs, ix = GCOV_COUNTERS_SUMMABLE; ix--; csum++)
608 {
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++)
617 {
618 histo_bitvector[bv_ix] = gcov_read_unsigned ();
619#if IN_LIBGCOV
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]);
625#else
626 h_cnt += popcount_hwi (histo_bitvector[bv_ix]);
627#endif
628 }
629 bv_ix = 0;
630 h_ix = 0;
631 cur_bitvector = 0;
632 while (h_cnt--)
633 {
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)
639 {
640 h_ix = bv_ix * 32;
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++];
645 }
646 while (!(cur_bitvector & 0x1))
647 {
648 h_ix++;
649 cur_bitvector >>= 1;
650 }
651 if (h_ix >= GCOV_HISTOGRAM_SIZE)
652 gcov_error ("corrupted profile info: summary histogram "
653 "index is corrupt");
654
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. */
660 cur_bitvector >>= 1;
661 h_ix++;
662 }
663 }
664}
665
666/* We need to expose the below function when compiling for gcov-tool. */
667
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. */
671
672GCOV_LINKAGE void
673gcov_sync (gcov_position_t base, gcov_unsigned_t length)
674{
675 gcov_nonruntime_assert (gcov_var.mode > 0);
676 base += length;
677 if (base - gcov_var.start <= gcov_var.length)
678 gcov_var.offset = base - gcov_var.start;
679 else
680 {
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;
684 }
685}
686#endif
687
688#if IN_LIBGCOV
689/* Move to a given position in a gcov file. */
690
691GCOV_LINKAGE void
692gcov_seek (gcov_position_t base)
693{
694 if (gcov_var.offset)
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;
698}
699#endif
700
701#if IN_GCOV > 0
702/* Return the modification time of the current gcov file. */
703
704GCOV_LINKAGE time_t
705gcov_time (void)
706{
707 struct stat status;
708
709 if (fstat (fileno (gcov_var.file), &status))
710 return 0;
711 else
712 return status.st_mtime;
713}
714#endif /* IN_GCOV */
715
716#if !IN_GCOV
717/* Determine the index into histogram for VALUE. */
718
719#if IN_LIBGCOV
720static unsigned
721#else
722GCOV_LINKAGE unsigned
723#endif
724gcov_histo_index (gcov_type value)
725{
726 gcov_type_unsigned v = (gcov_type_unsigned)value;
727 unsigned r = 0;
728 unsigned prev2bits = 0;
729
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. */
733
734 /* Find the place of the most-significant bit set. */
735 if (v > 0)
736 {
737#if IN_LIBGCOV
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);
743#else
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. */
746 r = floor_log2 (v);
747#endif
748 }
749
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
752 four buckets. */
753 if (r < 2)
754 return (unsigned)value;
755
756 gcov_nonruntime_assert (r < 64);
757
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
764 point is 4. */
765 return (r - 1) * 4 + prev2bits;
766}
767
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. */
773
774static void gcov_histogram_merge (gcov_bucket_type *tgt_histo,
775 gcov_bucket_type *src_histo)
776{
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;
780 gcov_type merge_min;
781 gcov_bucket_type tmp_histo[GCOV_HISTOGRAM_SIZE];
782 int src_done = 0;
783
784 memset (tmp_histo, 0, sizeof (gcov_bucket_type) * GCOV_HISTOGRAM_SIZE);
785
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. */
789 src_num = 0;
790 src_cum = 0;
791 src_i = GCOV_HISTOGRAM_SIZE - 1;
792 for (tgt_i = GCOV_HISTOGRAM_SIZE - 1; tgt_i >= 0 && !src_done; tgt_i--)
793 {
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
798 source histogram. */
799 while (tgt_num > 0 && !src_done)
800 {
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. */
804 if (!src_num)
805 {
806 /* Locate the next non-zero entry. */
807 while (src_i >= 0 && !src_histo[src_i].num_counters)
808 src_i--;
809 /* If source histogram has fewer counters, then just copy over the
810 remaining target counters and quit. */
811 if (src_i < 0)
812 {
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;
818 while (--tgt_i >= 0)
819 {
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;
827 }
828
829 src_done = 1;
830 break;
831 }
832
833 src_num = src_histo[src_i].num_counters;
834 src_cum = src_histo[src_i].cum_value;
835 }
836
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. */
840 merge_num = tgt_num;
841 if (src_num < merge_num)
842 merge_num = src_num;
843
844 /* The merged min_value is the sum of the min_values from target
845 and source. */
846 merge_min = tgt_histo[tgt_i].min_value + src_histo[src_i].min_value;
847
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
860 components. */
861 merge_cum = merge_src_cum + merge_tgt_cum;
862
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;
869
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;
879
880 /* Ensure the search for the next non-zero src_histo entry starts
881 at the next smallest histogram bucket. */
882 if (!src_num)
883 src_i--;
884 }
885 }
886
887 gcov_nonruntime_assert (tgt_i < 0);
888
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. */
895 if (src_num)
896 src_i--;
897 while (src_i >= 0)
898 {
899 src_cum += src_histo[src_i].cum_value;
900 src_i--;
901 }
902 /* At this point, tmp_i should be the smallest non-zero entry in the
903 tmp_histo. */
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;
907
908 /* Finally, copy the merged histogram into tgt_histo. */
909 memcpy (tgt_histo, tmp_histo,
910 sizeof (gcov_bucket_type) * GCOV_HISTOGRAM_SIZE);
911}
912#endif /* !IN_GCOV */
913
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. */
922
923GCOV_LINKAGE void
924compute_working_sets (const struct gcov_ctr_summary *summary,
925 gcov_working_set_t *gcov_working_sets)
926{
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;
932 int h_ix;
933
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;
938
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;
952
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--)
964 {
965 histo_bucket = &summary->histogram[h_ix];
966
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
970 entry. */
971 if (cum + histo_bucket->cum_value < working_set_cum_values[ws_ix])
972 {
973 cum += histo_bucket->cum_value;
974 count += histo_bucket->num_counters;
975 continue;
976 }
977
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;
985 c_num++)
986 {
987 count++;
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
993 divide operation. */
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. */
998 else
999 tmp_cum = cum + histo_bucket->cum_value;
1000
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])
1006 {
1007 gcov_working_sets[ws_ix].num_counters = count;
1008 gcov_working_sets[ws_ix].min_counter
1009 = histo_bucket->min_value;
1010 ws_ix++;
1011 }
1012 }
1013 /* Finally, update the running cumulative value since we were
1014 using a temporary above. */
1015 cum += histo_bucket->cum_value;
1016 }
1017 gcov_nonruntime_assert (ws_ix == NUM_GCOV_WORKING_SETS);
1018}
1019#endif /* IN_GCOV <= 0 && !IN_LIBGCOV */
1020