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author | Martin Liska <mliska@suse.cz> | 2020-01-31 13:10:14 +0100 |
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committer | Martin Liska <mliska@suse.cz> | 2020-06-02 12:11:02 +0200 |
commit | 871e5ada6d53d5eb495cc9f323983f347487c1b2 (patch) | |
tree | 15075fc87b2c7817e72f0b26b065a91e7963d0e6 /libgcc | |
parent | 23438370f768802fefd732529177fcea074c493b (diff) | |
download | gcc-871e5ada6d53d5eb495cc9f323983f347487c1b2.zip gcc-871e5ada6d53d5eb495cc9f323983f347487c1b2.tar.gz gcc-871e5ada6d53d5eb495cc9f323983f347487c1b2.tar.bz2 |
Make TOPN counter dynamically allocated.
gcc/ChangeLog:
* coverage.c (get_coverage_counts): Skip sanity check for TOP N counters
as they have variable number of counters.
* gcov-dump.c (main): Add new option -r.
(print_usage): Likewise.
(tag_counters): All new raw format.
* gcov-io.h (struct gcov_kvp): New.
(GCOV_TOPN_VALUES): Remove.
(GCOV_TOPN_VALUES_COUNTERS): Likewise.
(GCOV_TOPN_MEM_COUNTERS): New.
(GCOV_TOPN_DISK_COUNTERS): Likewise.
(GCOV_TOPN_MAXIMUM_TRACKED_VALUES): Likewise.
* ipa-profile.c (ipa_profile_generate_summary): Use
GCOV_TOPN_MAXIMUM_TRACKED_VALUES.
(ipa_profile_write_edge_summary): Likewise.
(ipa_profile_read_edge_summary): Likewise.
(ipa_profile): Remove usage of GCOV_TOPN_VALUES.
* profile.c (sort_hist_values): Sort variable number
of counters.
(compute_value_histograms): Special case for TOP N counters
that have dynamic number of key-value pairs.
* value-prof.c (dump_histogram_value): Dump variable number
of key-value pairs.
(stream_in_histogram_value): Stream in variable number
of key-value pairs for TOP N counter.
(get_nth_most_common_value): Deal with variable number
of key-value pairs.
(dump_ic_profile): Use GCOV_TOPN_MAXIMUM_TRACKED_VALUES
for loop iteration.
(gimple_find_values_to_profile): Set GCOV_TOPN_MEM_COUNTERS
to n_counters.
* doc/gcov-dump.texi: Document new -r option.
libgcc/ChangeLog:
* libgcov-driver.c (prune_topn_counter): Remove.
(prune_counters): Likewise.
(merge_one_data): Special case TOP N counters
as they have variable length.
(write_top_counters): New.
(write_one_data): Special case TOP N.
(dump_one_gcov): Do not prune TOP N counters.
* libgcov-merge.c (merge_topn_values_set): Remove.
(__gcov_merge_topn): Use gcov_topn_add_value.
* libgcov-profiler.c (__gcov_topn_values_profiler_body):
Likewise here.
* libgcov.h (gcov_counter_add): New.
(gcov_counter_set_if_null): Likewise.
(gcov_topn_add_value): New.
Diffstat (limited to 'libgcc')
-rw-r--r-- | libgcc/libgcov-driver.c | 116 | ||||
-rw-r--r-- | libgcc/libgcov-merge.c | 103 | ||||
-rw-r--r-- | libgcc/libgcov-profiler.c | 40 | ||||
-rw-r--r-- | libgcc/libgcov.h | 87 |
4 files changed, 162 insertions, 184 deletions
diff --git a/libgcc/libgcov-driver.c b/libgcc/libgcov-driver.c index fb32073..8348d9f 100644 --- a/libgcc/libgcov-driver.c +++ b/libgcc/libgcov-driver.c @@ -213,51 +213,6 @@ 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) -{ - 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. */ @@ -346,16 +301,18 @@ merge_one_data (const char *filename, if (!merge) continue; - tag = gcov_read_unsigned (); - length = gcov_read_unsigned (); - if (tag != GCOV_TAG_FOR_COUNTER (t_ix) - || length != GCOV_TAG_COUNTER_LENGTH (ci_ptr->num)) - goto read_mismatch; - (*merge) (ci_ptr->values, ci_ptr->num); - ci_ptr++; - } + tag = gcov_read_unsigned (); + length = gcov_read_unsigned (); + if (tag != GCOV_TAG_FOR_COUNTER (t_ix) + || (length != GCOV_TAG_COUNTER_LENGTH (ci_ptr->num) + && t_ix != GCOV_COUNTER_V_TOPN + && t_ix != GCOV_COUNTER_V_INDIR)) + goto read_mismatch; + (*merge) (ci_ptr->values, ci_ptr->num); + ci_ptr++; + } if ((error = gcov_is_error ())) - goto read_error; + goto read_error; } if (tag) @@ -374,6 +331,37 @@ read_error: return -1; } +/* Store all TOP N counters where each has a dynamic length. */ + +static void +write_top_counters (const struct gcov_ctr_info *ci_ptr, + unsigned t_ix, + gcov_unsigned_t n_counts) +{ + unsigned counters = n_counts / GCOV_TOPN_MEM_COUNTERS; + gcc_assert (n_counts % GCOV_TOPN_MEM_COUNTERS == 0); + unsigned pair_total = 0; + for (unsigned i = 0; i < counters; i++) + pair_total += ci_ptr->values[GCOV_TOPN_MEM_COUNTERS * i + 1]; + unsigned disk_size = GCOV_TOPN_DISK_COUNTERS * counters + 2 * pair_total; + gcov_write_tag_length (GCOV_TAG_FOR_COUNTER (t_ix), + GCOV_TAG_COUNTER_LENGTH (disk_size)); + + for (unsigned i = 0; i < counters; i++) + { + gcov_type pair_count = ci_ptr->values[GCOV_TOPN_MEM_COUNTERS * i + 1]; + gcov_write_counter (ci_ptr->values[GCOV_TOPN_MEM_COUNTERS * i]); + gcov_write_counter (pair_count); + for (struct gcov_kvp *node + = (struct gcov_kvp *)ci_ptr->values[GCOV_TOPN_MEM_COUNTERS * i + 2]; + node != NULL; node = node->next) + { + gcov_write_counter (node->value); + gcov_write_counter (node->count); + } + } +} + /* Write counters in GI_PTR and the summary in PRG to a gcda file. In the case of appending to an existing file, SUMMARY_POS will be non-zero. We will write the file starting from SUMMAY_POS. */ @@ -433,11 +421,18 @@ write_one_data (const struct gcov_info *gi_ptr, continue; n_counts = ci_ptr->num; - gcov_write_tag_length (GCOV_TAG_FOR_COUNTER (t_ix), - GCOV_TAG_COUNTER_LENGTH (n_counts)); - c_ptr = ci_ptr->values; - while (n_counts--) - gcov_write_counter (*c_ptr++); + + if (gi_ptr->merge[t_ix] == __gcov_merge_topn) + write_top_counters (ci_ptr, t_ix, n_counts); + else + { + gcov_write_tag_length (GCOV_TAG_FOR_COUNTER (t_ix), + GCOV_TAG_COUNTER_LENGTH (n_counts)); + c_ptr = ci_ptr->values; + while (n_counts--) + gcov_write_counter (*c_ptr++); + } + ci_ptr++; } if (buffered) @@ -476,9 +471,6 @@ dump_one_gcov (struct gcov_info *gi_ptr, struct gcov_filename *gf, 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-merge.c b/libgcc/libgcov-merge.c index c0785b0..1acdaa0 100644 --- a/libgcc/libgcov-merge.c +++ b/libgcc/libgcov-merge.c @@ -86,86 +86,6 @@ __gcov_merge_time_profile (gcov_type *counters, unsigned n_counters) #ifdef L_gcov_merge_topn -/* To merging of TOPN profiles. - counters[0] is the number of executions - for i in 0 ... TOPN-1 - counters[2 * i + 1] is target - counters[2 * i + 2] is corresponding hitrate counter. - - Because we prune counters only those with probability >= 1/TOPN are - present now. - - We use sign of counters[0] to track whether the number of different - targets exceeds TOPN. */ - -static void -merge_topn_values_set (gcov_type *counters) -{ - /* First value is number of total executions of the profiler. */ - gcov_type all = gcov_get_counter (); - gcov_type *total = &counters[0]; - ++counters; - - /* Negative value means that counter is missing some of values. */ - if (all < 0) - *total = -(*total); - - *total += all; - - /* Read all part values. */ - gcov_type read_counters[2 * GCOV_TOPN_VALUES]; - for (unsigned i = 0; i < GCOV_TOPN_VALUES; i++) - { - read_counters[2 * i] = gcov_get_counter_target (); - read_counters[2 * i + 1] = gcov_get_counter_ignore_scaling (-1); - } - - for (unsigned i = 0; i < GCOV_TOPN_VALUES; i++) - { - if (read_counters[2 * i + 1] == 0) - continue; - - unsigned j; - int slot = 0; - - for (j = 0; j < GCOV_TOPN_VALUES; j++) - { - if (counters[2 * j] == read_counters[2 * i]) - { - counters[2 * j + 1] += read_counters[2 * i + 1]; - break; - } - else if (counters[2 * j + 1] < counters[2 * slot + 1]) - slot = j; - } - - if (j == GCOV_TOPN_VALUES) - { - gcov_type slot_count = counters[2 * slot + 1]; - /* We found an empty slot. */ - if (slot_count == 0) - { - /* If we found empty slot, add the value. */ - counters[2 * slot] = read_counters[2 * i]; - counters[2 * slot + 1] = read_counters[2 * i + 1]; - } - else - { - /* Here we are loosing some values. */ - if (*total >= 0) - *total = -(*total); - if (read_counters[2 * i + 1] > slot_count) - { - counters[2 * slot] = read_counters[2 * i]; - counters[2 * slot + 1] = read_counters[2 * i + 1]; - } - else - counters[2 * slot + 1] -= read_counters[2 * i + 1]; - } - } - } -} - /* The profile merging function for choosing the most common value. It is given an array COUNTERS of N_COUNTERS old counters and it reads the same number of counters from the gcov file. The counters @@ -175,13 +95,30 @@ merge_topn_values_set (gcov_type *counters) -- the stored candidate on the most common value of the measured entity -- counter */ + void __gcov_merge_topn (gcov_type *counters, unsigned n_counters) { - gcc_assert (!(n_counters % GCOV_TOPN_VALUES_COUNTERS)); + gcc_assert (!(n_counters % GCOV_TOPN_MEM_COUNTERS)); - for (unsigned i = 0; i < (n_counters / GCOV_TOPN_VALUES_COUNTERS); i++) - merge_topn_values_set (counters + (i * GCOV_TOPN_VALUES_COUNTERS)); + for (unsigned i = 0; i < (n_counters / GCOV_TOPN_MEM_COUNTERS); i++) + { + /* First value is number of total executions of the profiler. */ + gcov_type all = gcov_get_counter_ignore_scaling (-1); + gcov_type n = gcov_get_counter_ignore_scaling (-1); + + counters[GCOV_TOPN_MEM_COUNTERS * i] += all; + + for (unsigned j = 0; j < n; j++) + { + gcov_type value = gcov_get_counter_target (); + gcov_type count = gcov_get_counter_ignore_scaling (-1); + + // TODO: we should use atomic here + gcov_topn_add_value (counters + GCOV_TOPN_MEM_COUNTERS * i, value, + count, 0, 0); + } + } } #endif /* L_gcov_merge_topn */ diff --git a/libgcc/libgcov-profiler.c b/libgcc/libgcov-profiler.c index 6043ac4..7b17138 100644 --- a/libgcc/libgcov-profiler.c +++ b/libgcc/libgcov-profiler.c @@ -105,51 +105,13 @@ __gcov_pow2_profiler_atomic (gcov_type *counters, gcov_type value) } #endif - /* Tries to determine N most commons value among its inputs. */ static inline void __gcov_topn_values_profiler_body (gcov_type *counters, gcov_type value, int use_atomic) { - if (use_atomic) - __atomic_fetch_add (&counters[0], 1, __ATOMIC_RELAXED); - else - counters[0]++; - - ++counters; - - /* First try to find an existing value. */ - int empty_counter = -1; - - for (unsigned i = 0; i < GCOV_TOPN_VALUES; i++) - if (value == counters[2 * i]) - { - if (use_atomic) - __atomic_fetch_add (&counters[2 * i + 1], GCOV_TOPN_VALUES, - __ATOMIC_RELAXED); - else - counters[2 * i + 1] += GCOV_TOPN_VALUES; - return; - } - else if (counters[2 * i + 1] <= 0) - empty_counter = i; - - /* Find an empty slot for a new value. */ - if (empty_counter != -1) - { - counters[2 * empty_counter] = value; - counters[2 * empty_counter + 1] = GCOV_TOPN_VALUES; - return; - } - - /* 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]--; + gcov_topn_add_value (counters, value, 1, use_atomic, 1); } #ifdef L_gcov_topn_values_profiler diff --git a/libgcc/libgcov.h b/libgcc/libgcov.h index b248690..bc38f4d 100644 --- a/libgcc/libgcov.h +++ b/libgcc/libgcov.h @@ -373,6 +373,93 @@ gcov_get_counter_target (void) #endif } +/* Add VALUE to *COUNTER and make it with atomic operation + if USE_ATOMIC is true. */ + +static inline void +gcov_counter_add (gcov_type *counter, gcov_type value, int use_atomic) +{ + if (use_atomic) + __atomic_fetch_add (counter, value, __ATOMIC_RELAXED); + else + *counter += value; +} + +/* Set NODE to memory location COUNTER and make it with atomic operation + if USE_ATOMIC is true. */ + +static inline int +gcov_counter_set_if_null (gcov_type *counter, struct gcov_kvp *node, + int use_atomic) +{ + if (use_atomic) + return !__sync_val_compare_and_swap (counter, NULL, (intptr_t)node); + else + { + *counter = (intptr_t)node; + return 1; + } +} + +/* Add key value pair VALUE:COUNT to a top N COUNTERS. When INCREMENT_TOTAL + is true, add COUNT to total of the TOP counter. If USE_ATOMIC is true, + do it in atomic way. */ + +static inline void +gcov_topn_add_value (gcov_type *counters, gcov_type value, gcov_type count, + int use_atomic, int increment_total) +{ + if (increment_total) + gcov_counter_add (&counters[0], 1, use_atomic); + + struct gcov_kvp *prev_node = NULL; + struct gcov_kvp *minimal_node = NULL; + struct gcov_kvp *current_node = (struct gcov_kvp *)counters[2]; + + while (current_node) + { + if (current_node->value == value) + { + gcov_counter_add (¤t_node->count, count, use_atomic); + return; + } + + if (minimal_node == NULL + || current_node->count < minimal_node->count) + minimal_node = current_node; + + prev_node = current_node; + current_node = current_node->next; + } + + if (counters[1] == GCOV_TOPN_MAXIMUM_TRACKED_VALUES) + { + if (--minimal_node->count < count) + { + minimal_node->value = value; + minimal_node->count = count; + } + } + else + { + struct gcov_kvp *new_node + = (struct gcov_kvp *)xmalloc (sizeof (struct gcov_kvp)); + new_node->value = value; + new_node->count = count; + + int success = 0; + if (!counters[2]) + success = gcov_counter_set_if_null (&counters[2], new_node, use_atomic); + else if (prev_node && !prev_node->next) + success = gcov_counter_set_if_null ((gcov_type *)&prev_node->next, + new_node, use_atomic); + + /* Increment number of nodes. */ + if (success) + gcov_counter_add (&counters[1], 1, use_atomic); + } +} + #endif /* !inhibit_libc */ #endif /* GCC_LIBGCOV_H */ |