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author | Martin Liska <mliska@suse.cz> | 2020-01-22 12:08:11 +0100 |
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committer | Martin Liska <mliska@suse.cz> | 2020-01-22 12:08:11 +0100 |
commit | 5f32f9cf13f99f6295591927950aaf98aa8dba91 (patch) | |
tree | 59ab45c6e2d886178d1ca9e17317ffdc1c043c31 /libgcc | |
parent | f96af171bee93486896407ccad0e1e4dc200bc0c (diff) | |
download | gcc-5f32f9cf13f99f6295591927950aaf98aa8dba91.zip gcc-5f32f9cf13f99f6295591927950aaf98aa8dba91.tar.gz gcc-5f32f9cf13f99f6295591927950aaf98aa8dba91.tar.bz2 |
Smart relaxation of TOP N counter.
PR tree-optimization/92924
* profile.c (compute_value_histograms): Divide
all counter values.
PR tree-optimization/92924
* libgcov-driver.c (prune_topn_counter): New.
(prune_counters): Likewise.
(dump_one_gcov): Prune a run-time counter.
* libgcov-profiler.c (__gcov_topn_values_profiler_body):
For a known value, add GCOV_TOPN_VALUES to value.
Otherwise, decrement all counters by one.
Diffstat (limited to 'libgcc')
-rw-r--r-- | libgcc/ChangeLog | 10 | ||||
-rw-r--r-- | libgcc/libgcov-driver.c | 54 | ||||
-rw-r--r-- | libgcc/libgcov-profiler.c | 30 |
3 files changed, 77 insertions, 17 deletions
diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog index 5e8b506..441c8f0 100644 --- a/libgcc/ChangeLog +++ b/libgcc/ChangeLog @@ -1,3 +1,13 @@ +2020-01-22 Martin Liska <mliska@suse.cz> + + PR tree-optimization/92924 + * libgcov-driver.c (prune_topn_counter): New. + (prune_counters): Likewise. + (dump_one_gcov): Prune a run-time counter. + * libgcov-profiler.c (__gcov_topn_values_profiler_body): + For a known value, add GCOV_TOPN_VALUES to value. + Otherwise, decrement all counters by one. + 2020-01-18 Hans-Peter Nilsson <hp@axis.com> * config/cris/arit.c (DS): Apply attribute __fallthrough__. diff --git a/libgcc/libgcov-driver.c b/libgcc/libgcov-driver.c index 1c07761..cdb611d 100644 --- a/libgcc/libgcov-driver.c +++ b/libgcc/libgcov-driver.c @@ -213,6 +213,56 @@ static struct gcov_fn_buffer *fn_buffer; /* Including system dependent components. */ #include "libgcov-driver-system.c" +/* Prune TOP N value COUNTERS. It's needed in order to preserve + reproducibility of builds. */ + +static void +prune_topn_counter (gcov_type *counters, gcov_type all) +{ + if (counters[1] == -1) + return; + + for (unsigned i = 0; i < GCOV_TOPN_VALUES; i++) + { + if (counters[2 * i + 1] < all) + { + counters[2 * i] = 0; + counters[2 * i + 1] = 0; + } + } +} + +/* Prune counters so that they are ready to store or merge. */ + +static void +prune_counters (struct gcov_info *gi) +{ + for (unsigned i = 0; i < gi->n_functions; i++) + { + const struct gcov_fn_info *gfi = gi->functions[i]; + const struct gcov_ctr_info *ci = gfi->ctrs; + + for (unsigned j = 0; j < GCOV_COUNTERS; j++) + { + if (gi->merge[j] == NULL) + continue; + + if (gi->merge[j] == __gcov_merge_topn) + { + gcc_assert (!(ci->num % GCOV_TOPN_VALUES_COUNTERS)); + for (unsigned k = 0; k < (ci->num / GCOV_TOPN_VALUES_COUNTERS); + k++) + { + gcov_type *counters + = ci->values + (k * GCOV_TOPN_VALUES_COUNTERS); + prune_topn_counter (counters + 1, *counters); + } + } + ci++; + } + } +} + /* This function merges counters in GI_PTR to an existing gcda file. Return 0 on success. Return -1 on error. In this case, caller will goto read_fatal. */ @@ -429,9 +479,11 @@ dump_one_gcov (struct gcov_info *gi_ptr, struct gcov_filename *gf, struct gcov_summary summary = {}; int error; gcov_unsigned_t tag; - fn_buffer = 0; + /* Prune current counters before we merge them. */ + prune_counters (gi_ptr); + error = gcov_exit_open_gcda_file (gi_ptr, gf); if (error == -1) return; diff --git a/libgcc/libgcov-profiler.c b/libgcc/libgcov-profiler.c index 9417904..f45ef49 100644 --- a/libgcc/libgcov-profiler.c +++ b/libgcc/libgcov-profiler.c @@ -119,37 +119,35 @@ __gcov_topn_values_profiler_body (gcov_type *counters, gcov_type value, ++counters; - /* We have GCOV_TOPN_VALUES as we can keep multiple values - next to each other. */ - unsigned sindex = 0; - for (unsigned i = 0; i < GCOV_TOPN_VALUES; i++) { if (value == counters[2 * i]) { if (use_atomic) - __atomic_fetch_add (&counters[2 * i + 1], 1, __ATOMIC_RELAXED); + __atomic_fetch_add (&counters[2 * i + 1], GCOV_TOPN_VALUES, + __ATOMIC_RELAXED); else - counters[2 * i + 1]++; + counters[2 * i + 1] += GCOV_TOPN_VALUES; return; } - else if (counters[2 * i + 1] == 0) + else if (counters[2 * i + 1] <= 0) { /* We found an empty slot. */ counters[2 * i] = value; - counters[2 * i + 1] = 1; + counters[2 * i + 1] = GCOV_TOPN_VALUES; return; } - - if (counters[2 * i + 1] < counters[2 * sindex + 1]) - sindex = i; } - /* We haven't found an empty slot, then decrement the smallest. */ - if (use_atomic) - __atomic_fetch_sub (&counters[2 * sindex + 1], 1, __ATOMIC_RELAXED); - else - counters[2 * sindex + 1]--; + /* We haven't found an empty slot, then decrement all + counter values by one. */ + for (unsigned i = 0; i < GCOV_TOPN_VALUES; i++) + { + if (use_atomic) + __atomic_fetch_sub (&counters[2 * i + 1], 1, __ATOMIC_RELAXED); + else + counters[2 * i + 1]--; + } } #ifdef L_gcov_topn_values_profiler |