- Generated by
1.8.1.1
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GCC Middle and Back End API Reference
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| static void | gcov_write_block (unsigned) |
| static gcov_unsigned_t * | gcov_write_words (unsigned) |
| static const gcov_unsigned_t * | gcov_read_words (unsigned) |
| static void | gcov_allocate (unsigned) |
| static gcov_unsigned_t | from_file (gcov_unsigned_t value) |
| GCOV_LINKAGE int | gcov_open (#else gcov_open(const char *name, int mode)#endif) |
| GCOV_LINKAGE int | gcov_close () |
| GCOV_LINKAGE int | gcov_magic () |
| static void | gcov_allocate () |
| static void | gcov_write_block () |
| static gcov_unsigned_t * | gcov_write_words () |
| GCOV_LINKAGE void | gcov_write_unsigned () |
| GCOV_LINKAGE void | gcov_write_counter () |
| GCOV_LINKAGE void | gcov_write_string () |
| GCOV_LINKAGE gcov_position_t | gcov_write_tag () |
| GCOV_LINKAGE void | gcov_write_length () |
| GCOV_LINKAGE void | gcov_write_tag_length () |
| GCOV_LINKAGE void | gcov_write_summary () |
| static const gcov_unsigned_t * | gcov_read_words () |
| GCOV_LINKAGE gcov_unsigned_t | gcov_read_unsigned () |
| GCOV_LINKAGE gcov_type | gcov_read_counter () |
| GCOV_LINKAGE const char * | gcov_read_string () |
| GCOV_LINKAGE void | gcov_read_summary () |
| GCOV_LINKAGE void | gcov_sync () |
| GCOV_LINKAGE void | gcov_seek () |
| GCOV_LINKAGE time_t | gcov_time () |
| static unsigned GCOV_LINKAGE unsigned | gcov_histo_index () |
| static void | gcov_histogram_merge (gcov_bucket_type *tgt_histo, gcov_bucket_type *src_histo) |
| GCOV_LINKAGE void | compute_working_sets (const struct gcov_ctr_summary *summary, gcov_working_set_t *gcov_working_sets) |
| GCOV_LINKAGE void compute_working_sets | ( | const struct gcov_ctr_summary * | summary, |
| gcov_working_set_t * | gcov_working_sets | ||
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This is used by gcov-dump (IN_GCOV == -1) and in the compiler (!IN_GCOV && !IN_LIBGCOV).
Compute the working set information from the counter histogram in the profile summary. This is an array of information corresponding to a range of percentages of the total execution count (sum_all), and includes the number of counters required to cover that working set percentage and the minimum counter value in that working set.
Compute the amount of sum_all that the cumulative hotness grows
by in each successive working set entry, which depends on the
number of working set entries. Next fill in an array of the cumulative hotness values corresponding
to each working set summary entry we are going to compute below.
Skip 0% statistics, which can be extrapolated from the
rest of the summary data. The last summary entry is reserved for (roughly) 99.9% of the
working set. Divide by 1024 so it becomes a shift, which gives
almost exactly 99.9%. Next, walk through the histogram in decending order of hotness
and compute the statistics for the working set summary array.
As histogram entries are accumulated, we check to see which
working set entries have had their expected cum_value reached
and fill them in, walking the working set entries in increasing
size of cum_value. If we haven't reached the required cumulative counter value for
the current working set percentage, simply accumulate this histogram
entry into the running sums and continue to the next histogram
entry. If adding the current histogram entry's cumulative counter value
causes us to exceed the current working set size, then estimate
how many of this histogram entry's counter values are required to
reach the working set size, and fill in working set entries
as we reach their expected cumulative value. If we haven't reached the last histogram entry counter, add
in the minimum value again. This will underestimate the
cumulative sum so far, because many of the counter values in this
entry may have been larger than the minimum. We could add in the
average value every time, but that would require an expensive
divide operation. If we have reached the last histogram entry counter, then add
in the entire cumulative value. Next walk through successive working set entries and fill in
the statistics for any whose size we have reached by accumulating
this histogram counter. Finally, update the running cumulative value since we were
using a temporary above.
References count, gcov_bucket_type::cum_value, gcov_working_set_info::min_counter, gcov_bucket_type::min_value, gcov_bucket_type::num_counters, and gcov_working_set_info::num_counters.
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| GCOV_LINKAGE int gcov_close | ( | void | ) |
Close the current gcov file. Flushes data to disk. Returns nonzero on failure or error flag set.
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Determine the index into histogram for VALUE.
Find index into log2 scale histogram, where each of the log2
sized buckets is divided into 4 linear sub-buckets for better
focus in the higher buckets. Find the place of the most-significant bit set.
When building libgcov we don't include system.h, which includes
hwint.h (where floor_log2 is declared). However, libgcov.a
is built by the bootstrapped compiler and therefore the builtins
are always available. We use floor_log2 from hwint.c, which takes a HOST_WIDE_INT
that is either 32 or 64 bits, and gcov_type_unsigned may be 64 bits.
Need to check for the case where gcov_type_unsigned is 64 bits
and HOST_WIDE_INT is 32 bits and handle it specially. If at most the 2 least significant bits are set (value is
0 - 3) then that value is our index into the lowest set of
four buckets. Find the two next most significant bits to determine which
of the four linear sub-buckets to select. Finally, compose the final bucket index from the log2 index and
the next 2 bits. The minimum r value at this point is 2 since we
returned above if r was 2 or more, so the minimum bucket at this
point is 4.
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Merge SRC_HISTO into TGT_HISTO. The counters are assumed to be in the same relative order in both histograms, and are matched up and merged in reverse order. Each counter is assigned an equal portion of its entry's original cumulative counter value when computing the new merged cum_value.
Assume that the counters are in the same relative order in both
histograms. Walk the histograms from largest to smallest entry,
matching up and combining counters in order. Keep going until all of the target histogram's counters at this
position have been matched and merged with counters from the
source histogram. If this is either the first time through this loop or we just
exhausted the previous non-zero source histogram entry, look
for the next non-zero source histogram entry. Locate the next non-zero entry.
If source histogram has fewer counters, then just copy over the
remaining target counters and quit. The number of counters to merge on this pass is the minimum
of the remaining counters from the current target and source
histogram entries. The merged min_value is the sum of the min_values from target
and source. Compute the portion of source and target entries' cum_value
that will be apportioned to the counters being merged.
The total remaining cum_value from each entry is divided
equally among the counters from that histogram entry if we
are not merging all of them. The merged cum_value is the sum of the source and target
components. Update the remaining number of counters and cum_value left
to be merged from this source and target entry. The merged counters get placed in the new merged histogram
at the entry for the merged min_value. Ensure the search for the next non-zero src_histo entry starts
at the next smallest histogram bucket. In the case where there were more counters in the source histogram,
accumulate the remaining unmerged cumulative counter values. Add
those to the smallest non-zero target histogram entry. Otherwise,
the total cumulative counter values in the histogram will be smaller
than the sum_all stored in the summary, which will complicate
computing the working set information from the histogram later on. At this point, tmp_i should be the smallest non-zero entry in the
tmp_histo. Finally, copy the merged histogram into tgt_histo.
References gcov_bucket_type::cum_value, gcov_bucket_type::min_value, and gcov_bucket_type::num_counters.
| GCOV_LINKAGE int gcov_magic | ( | ) |
Check if MAGIC is EXPECTED. Use it to determine endianness of the file. Returns +1 for same endian, -1 for other endian and zero for not EXPECTED.
| GCOV_LINKAGE int gcov_open | ( | #else gcov_open(const char *name, int mode)# | endif | ) |
Open a gcov file. NAME is the name of the file to open and MODE indicates whether a new file should be created, or an existing file opened. If MODE is >= 0 an existing file will be opened, if possible, and if MODE is <= 0, a new file will be created. Use MODE=0 to attempt to reopen an existing file and then fall back on creating a new one. If MODE < 0, the file will be opened in read-only mode. Otherwise it will be opened for modification. Return zero on failure, >0 on opening an existing file and <0 on creating a new one.
Read-only mode - acquire a read-lock.
pass mode (ignored) for compatibility
Write mode - acquire a write-lock.
References gcov_var::endian, errno, gcov_var::error, gcov_var::file, gcov_var::length, gcov_var::mode, gcov_var::offset, gcov_var::overread, and gcov_var::start.
Referenced by coverage_obj_fn().
| GCOV_LINKAGE gcov_type gcov_read_counter | ( | void | ) |
Read counter value from a coverage file. Sets error flag on file error, overflow flag on overflow
References gcov_read_unsigned(), and gcov_read_words().
| GCOV_LINKAGE const char* gcov_read_string | ( | void | ) |
Read string from coverage file. Returns a pointer to a static buffer, or NULL on empty string. You must copy the string before calling another gcov function.
Referenced by tag_lines().
| GCOV_LINKAGE void gcov_read_summary | ( | ) |
When building libgcov we don't include system.h, which includes
hwint.h (where popcount_hwi is declared). However, libgcov.a
is built by the bootstrapped compiler and therefore the builtins
are always available. Find the index corresponding to the next entry we will read in.
First find the next non-zero bitvector and re-initialize
the histogram index accordingly, then right shift and increment
the index until we find a set bit. Shift off the index we are done with and increment to the
corresponding next histogram entry.
| GCOV_LINKAGE gcov_unsigned_t gcov_read_unsigned | ( | void | ) |
Read unsigned value from a coverage file. Sets error flag on file error, overflow flag on overflow
Referenced by gcov_read_counter(), read_graph_file(), and tag_lines().
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Referenced by gcov_read_counter().
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Return a pointer to read BYTES bytes from the gcov file. Returns NULL on failure (read past EOF).
| GCOV_LINKAGE void gcov_seek | ( | ) |
Move to a given position in a gcov file.
| GCOV_LINKAGE void gcov_sync | ( | ) |
Reset to a known position. BASE should have been obtained from gcov_position, LENGTH should be a record length.
| GCOV_LINKAGE time_t gcov_time | ( | void | ) |
Return the modification time of the current gcov file.
References floor_log2(), HOST_BITS_PER_WIDE_INT, and HOST_WIDE_INT.
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@verbatim
File format for coverage information Copyright (C) 1996-2013 Free Software Foundation, Inc. Contributed by Bob Manson manson@cygnus.com. Completely remangled by Nathan Sidwell nathan@codesourcery.com.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
Under Section 7 of GPL version 3, you are granted additional permissions described in the GCC Runtime Library Exception, version 3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and a copy of the GCC Runtime Library Exception along with this program; see the files COPYING3 and COPYING.RUNTIME respectively. If not, see http://www.gnu.org/licenses/.
Routines declared in gcov-io.h. This file should be #included by another source file, after having #included gcov-io.h.
Referenced by gcov_write_block(), and gcov_write_tag().
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Write out the current block, if needs be.
References gcov_write_block(), gcov_var::mode, and gcov_var::offset.
| GCOV_LINKAGE void gcov_write_counter | ( | ) |
Write counter VALUE to coverage file. Sets error flag appropriately.
References buffer, gcov_write_words(), and strlen().
| GCOV_LINKAGE void gcov_write_length | ( | ) |
Write a record length using POSITION, which was returned by gcov_write_tag. The current file position is the end of the record, and is restored before returning. Returns nonzero on overflow.
| GCOV_LINKAGE void gcov_write_string | ( | ) |
Write STRING to coverage file. Sets error flag on file error, overflow flag on overflow
| GCOV_LINKAGE void gcov_write_summary | ( | ) |
Write a summary structure to the gcov file. Return nonzero on overflow.
Count number of non-zero histogram entries, and fill in a bit vector
of non-zero indices. The histogram is only currently computed for arc
counters.
| GCOV_LINKAGE gcov_position_t gcov_write_tag | ( | ) |
Write a tag TAG and reserve space for the record length. Return a value to be used for gcov_write_length.
References buffer, gcov_var::buffer, gcov_write_block(), gcov_var::mode, gcov_var::offset, offset, and gcov_var::start.
| GCOV_LINKAGE void gcov_write_tag_length | ( | ) |
Write a tag TAG and length LENGTH.
References gcov_ctr_summary::histogram, and gcov_bucket_type::num_counters.
| GCOV_LINKAGE void gcov_write_unsigned | ( | ) |
Write unsigned VALUE to coverage file. Sets error flag appropriately.
References buffer, and gcov_write_words().
Referenced by coverage_obj_fn().
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Referenced by gcov_write_counter(), and gcov_write_unsigned().
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Allocate space to write BYTES bytes to the gcov file. Return a pointer to those bytes, or NULL on failure.
References gcov_var::buffer, memcpy(), and gcov_var::offset.
1.8.1.1