diff options
| -rw-r--r-- | gcc/ChangeLog | 11 | ||||
| -rw-r--r-- | gcc/common.opt | 16 | ||||
| -rw-r--r-- | gcc/coretypes.h | 7 | ||||
| -rw-r--r-- | gcc/doc/invoke.texi | 31 | ||||
| -rw-r--r-- | gcc/value-prof.c | 29 | ||||
| -rw-r--r-- | libgcc/ChangeLog | 7 | ||||
| -rw-r--r-- | libgcc/libgcov-merge.c | 50 |
7 files changed, 128 insertions, 23 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index efc21166d6a..db6740a5006 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,14 @@ +2020-02-18 Martin Liska <mliska@suse.cz> + + PR ipa/92924 + * common.opt: Add -fprofile-reproducibility. + * doc/invoke.texi: Document it. + * value-prof.c (dump_histogram_value): + Document and support behavior for counters[0] + being a negative value. + (get_nth_most_common_value): Handle negative + counters[0] in respect to flag_profile_reproducible. + 2020-02-18 Jakub Jelinek <jakub@redhat.com> PR ipa/93797 diff --git a/gcc/common.opt b/gcc/common.opt index 5692cd04374..fa9da505fc2 100644 --- a/gcc/common.opt +++ b/gcc/common.opt @@ -2169,6 +2169,22 @@ Common Joined RejectNegative Var(flag_profile_exclude_files) Instrument only functions from files where names do not match all the regular expressions (separated by a semi-colon). Enum +Name(profile_reproducibility) Type(enum profile_reproducibility) UnknownError(unknown profile reproducibility method %qs) + +EnumValue +Enum(profile_reproducibility) String(serial) Value(PROFILE_REPRODUCIBILITY_SERIAL) + +EnumValue +Enum(profile_reproducibility) String(parallel-runs) Value(PROFILE_REPRODUCIBILITY_PARALLEL_RUNS) + +EnumValue +Enum(profile_reproducibility) String(multithreaded) Value(PROFILE_REPRODUCIBILITY_MULTITHREADED) + +fprofile-reproducible +Common Joined RejectNegative Var(flag_profile_reproducible) Enum(profile_reproducibility) Init(PROFILE_REPRODUCIBILITY_SERIAL) +-fprofile-reproducible=[serial|parallel-runs|multithreaded] Control level of reproducibility of profile gathered by -fprofile-generate. + +Enum Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs) EnumValue diff --git a/gcc/coretypes.h b/gcc/coretypes.h index d8fd50d79a4..cda22697cc3 100644 --- a/gcc/coretypes.h +++ b/gcc/coretypes.h @@ -212,6 +212,13 @@ enum profile_update { PROFILE_UPDATE_PREFER_ATOMIC }; +/* Type of profile reproducibility methods. */ +enum profile_reproducibility { + PROFILE_REPRODUCIBILITY_SERIAL, + PROFILE_REPRODUCIBILITY_PARALLEL_RUNS, + PROFILE_REPRODUCIBILITY_MULTITHREADED +}; + /* Types of unwind/exception handling info that can be generated. */ enum unwind_info_type diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 3e47d06f0d5..ba2b7e42520 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -562,7 +562,7 @@ Objective-C and Objective-C++ Dialects}. -fprofile-abs-path @gol -fprofile-dir=@var{path} -fprofile-generate -fprofile-generate=@var{path} @gol -fprofile-note=@var{path} -fprofile-update=@var{method} @gol --fprofile-filter-files=@var{regex} -fprofile-exclude-files=@var{regex} @gol +-fprofile-filter-files=@var{regex} -fprofile-exclude-files=@var{regex} -fprofile-reproducibility @gol -fsanitize=@var{style} -fsanitize-recover -fsanitize-recover=@var{style} @gol -fasan-shadow-offset=@var{number} -fsanitize-sections=@var{s1},@var{s2},... @gol -fsanitize-undefined-trap-on-error -fbounds-check @gol @@ -13360,6 +13360,35 @@ all the regular expressions (separated by a semi-colon). For example, @option{-fprofile-exclude-files=/usr/*} will prevent instrumentation of all files that are located in @file{/usr/} folder. +@item -fprofile-reproducible +@opindex fprofile-reproducible +Control level of reproducibility of profile gathered by +@code{-fprofile-generate}. This makes it possible to rebuild program +with same outcome which is useful, for example, for distribution +packages. + +With @option{-fprofile-reproducibility=serial} the profile gathered by +@option{-fprofile-generate} is reproducible provided the trained program +behaves the same at each invocation of the train run, it is not +multi-threaded and profile data streaming is always done in the same +order. Note that profile streaming happens at the end of program run but +also before @code{fork} function is invoked. + +Note that it is quite common that execution counts of some part of +programs depends, for example, on length of temporary file names or +memory space randomization (that may affect hash-table collision rate). +Such non-reproducible part of programs may be annotated by +@code{no_instrument_function} function attribute. @code{gcov-dump} with +@option{-l} can be used to dump gathered data and verify that they are +indeed reproducible. + +With @option{-fprofile-reproducibility=parallel-runs} collected profile +stays reproducible regardless the order of streaming of the data into +gcda files. This setting makes it possible to run multiple instances of +instrumented program in parallel (such as with @code{make -j}). This +reduces quality of gathered data, in particular of indirect call +profiling. + @item -fsanitize=address @opindex fsanitize=address Enable AddressSanitizer, a fast memory error detector. diff --git a/gcc/value-prof.c b/gcc/value-prof.c index f0456c8e93d..5f940f40399 100644 --- a/gcc/value-prof.c +++ b/gcc/value-prof.c @@ -265,8 +265,10 @@ dump_histogram_value (FILE *dump_file, histogram_value hist) ? "Top N value counter" : "Indirect call counter")); if (hist->hvalue.counters) { - fprintf (dump_file, " all: %" PRId64 ", values: ", - (int64_t) hist->hvalue.counters[0]); + fprintf (dump_file, " all: %" PRId64 "%s, values: ", + abs ((int64_t) hist->hvalue.counters[0]), + hist->hvalue.counters[0] < 0 + ? " (values missing)": ""); for (unsigned i = 0; i < GCOV_TOPN_VALUES; i++) { fprintf (dump_file, "[%" PRId64 ":%" PRId64 "]", @@ -719,26 +721,39 @@ gimple_divmod_fixed_value (gassign *stmt, tree value, profile_probability prob, /* Return the n-th value count of TOPN_VALUE histogram. If there's a value, return true and set VALUE and COUNT - arguments. */ + arguments. + + Counters have the following meaning. + + abs (counters[0]) is the number of executions + for i in 0 ... TOPN-1 + counters[2 * i + 1] is target + abs (counters[2 * i + 2]) is corresponding hitrate counter. + + Value of counters[0] negative when counter became + full during merging and some values are lost. */ bool get_nth_most_common_value (gimple *stmt, const char *counter_type, histogram_value hist, gcov_type *value, gcov_type *count, gcov_type *all, unsigned n) { - if (hist->hvalue.counters[2] == -1) - return false; - gcc_assert (n < GCOV_TOPN_VALUES); *count = 0; *value = 0; - gcov_type read_all = hist->hvalue.counters[0]; + gcov_type read_all = abs (hist->hvalue.counters[0]); gcov_type v = hist->hvalue.counters[2 * n + 1]; gcov_type c = hist->hvalue.counters[2 * n + 2]; + if (hist->hvalue.counters[0] < 0 + && (flag_profile_reproducible == PROFILE_REPRODUCIBILITY_PARALLEL_RUNS + || (flag_profile_reproducible + == PROFILE_REPRODUCIBILITY_MULTITHREADED))) + return false; + /* Indirect calls can't be verified. */ if (stmt && check_counter (stmt, counter_type, &c, &read_all, diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog index 7b46ccb40c9..dedc308b3bc 100644 --- a/libgcc/ChangeLog +++ b/libgcc/ChangeLog @@ -1,3 +1,10 @@ +2020-02-18 Martin Liska <mliska@suse.cz> + + PR ipa/92924 + * libgcov-merge.c (merge_topn_values_set): Record + when a TOP N counter becomes invalid. When merging + remove a smallest value if the space is needed. + 2020-02-12 Sandra Loosemore <sandra@codesourcery.com> PR libstdc++/79193 diff --git a/libgcc/libgcov-merge.c b/libgcc/libgcov-merge.c index 19b8ee72ae9..c0785b0bf10 100644 --- a/libgcc/libgcov-merge.c +++ b/libgcc/libgcov-merge.c @@ -86,36 +86,47 @@ __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_ignore_scaling (-1); - counters[0] += all; + 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); } - if (read_counters[1] == -1) - { - counters[1] = -1; - return; - } - for (unsigned i = 0; i < GCOV_TOPN_VALUES; i++) { if (read_counters[2 * i + 1] == 0) continue; unsigned j; - int slot = -1; + int slot = 0; for (j = 0; j < GCOV_TOPN_VALUES; j++) { @@ -124,13 +135,15 @@ merge_topn_values_set (gcov_type *counters) counters[2 * j + 1] += read_counters[2 * i + 1]; break; } - else if (counters[2 * j + 1] == 0) + else if (counters[2 * j + 1] < counters[2 * slot + 1]) slot = j; } if (j == GCOV_TOPN_VALUES) { - if (slot > 0) + 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]; @@ -138,9 +151,16 @@ merge_topn_values_set (gcov_type *counters) } else { - /* We haven't found a slot, bail out. */ - counters[1] = -1; - return; + /* 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]; } } } |