diff options
Diffstat (limited to 'libgcc/libgcov-profiler.c')
| -rw-r--r-- | libgcc/libgcov-profiler.c | 103 |
1 files changed, 98 insertions, 5 deletions
diff --git a/libgcc/libgcov-profiler.c b/libgcc/libgcov-profiler.c index a99d93bb412..70a821dc625 100644 --- a/libgcc/libgcov-profiler.c +++ b/libgcc/libgcov-profiler.c @@ -46,6 +46,26 @@ __gcov_interval_profiler (gcov_type *counters, gcov_type value, } #endif +#ifdef L_gcov_interval_profiler_atomic +/* If VALUE is in interval <START, START + STEPS - 1>, then increases the + corresponding counter in COUNTERS. If the VALUE is above or below + the interval, COUNTERS[STEPS] or COUNTERS[STEPS + 1] is increased + instead. Function is thread-safe. */ + +void +__gcov_interval_profiler_atomic (gcov_type *counters, gcov_type value, + int start, unsigned steps) +{ + gcov_type delta = value - start; + if (delta < 0) + __atomic_fetch_add (&counters[steps + 1], 1, MEMMODEL_RELAXED); + else if (delta >= steps) + __atomic_fetch_add (&counters[steps], 1, MEMMODEL_RELAXED); + else + __atomic_fetch_add (&counters[delta], 1, MEMMODEL_RELAXED); +} +#endif + #ifdef L_gcov_pow2_profiler /* If VALUE is a power of two, COUNTERS[1] is incremented. Otherwise COUNTERS[0] is incremented. */ @@ -60,6 +80,21 @@ __gcov_pow2_profiler (gcov_type *counters, gcov_type value) } #endif +#ifdef L_gcov_pow2_profiler_atomic +/* If VALUE is a power of two, COUNTERS[1] is incremented. Otherwise + COUNTERS[0] is incremented. Function is thread-safe. */ + +void +__gcov_pow2_profiler_atomic (gcov_type *counters, gcov_type value) +{ + if (value == 0 || (value & (value - 1))) + __atomic_fetch_add (&counters[0], 1, MEMMODEL_RELAXED); + else + __atomic_fetch_add (&counters[1], 1, MEMMODEL_RELAXED); +} +#endif + + /* Tries to determine the most common value among its inputs. Checks if the value stored in COUNTERS[0] matches VALUE. If this is the case, COUNTERS[1] is incremented. If this is not the case and COUNTERS[1] is not zero, @@ -68,10 +103,12 @@ __gcov_pow2_profiler (gcov_type *counters, gcov_type value) function is called more than 50% of the time with one value, this value will be in COUNTERS[0] in the end. - In any case, COUNTERS[2] is incremented. */ + In any case, COUNTERS[2] is incremented. If USE_ATOMIC is set to 1, + COUNTERS[2] is updated with an atomic instruction. */ static inline void -__gcov_one_value_profiler_body (gcov_type *counters, gcov_type value) +__gcov_one_value_profiler_body (gcov_type *counters, gcov_type value, + int use_atomic) { if (value == counters[0]) counters[1]++; @@ -82,14 +119,36 @@ __gcov_one_value_profiler_body (gcov_type *counters, gcov_type value) } else counters[1]--; - counters[2]++; + + if (use_atomic) + __atomic_fetch_add (&counters[2], 1, MEMMODEL_RELAXED); + else + counters[2]++; } #ifdef L_gcov_one_value_profiler void __gcov_one_value_profiler (gcov_type *counters, gcov_type value) { - __gcov_one_value_profiler_body (counters, value); + __gcov_one_value_profiler_body (counters, value, 0); +} +#endif + +#ifdef L_gcov_one_value_profiler_atomic + +/* Update one value profilers (COUNTERS) for a given VALUE. + + CAVEAT: Following function is not thread-safe, only total number + of executions (COUNTERS[2]) is update with an atomic instruction. + Problem is that one cannot atomically update two counters + (COUNTERS[0] and COUNTERS[1]), for more information please read + following email thread: + https://gcc.gnu.org/ml/gcc-patches/2016-08/msg00024.html. */ + +void +__gcov_one_value_profiler_atomic (gcov_type *counters, gcov_type value) +{ + __gcov_one_value_profiler_body (counters, value, 1); } #endif @@ -265,7 +324,7 @@ __gcov_indirect_call_profiler_v2 (gcov_type value, void* cur_func) if (cur_func == __gcov_indirect_call_callee || (__LIBGCC_VTABLE_USES_DESCRIPTORS__ && __gcov_indirect_call_callee && *(void **) cur_func == *(void **) __gcov_indirect_call_callee)) - __gcov_one_value_profiler_body (__gcov_indirect_call_counters, value); + __gcov_one_value_profiler_body (__gcov_indirect_call_counters, value, 0); } #endif @@ -282,8 +341,19 @@ __gcov_time_profiler (gcov_type* counters) if (!counters[0]) counters[0] = ++function_counter; } + +/* Sets corresponding COUNTERS if there is no value. + Function is thread-safe. */ + +void +__gcov_time_profiler_atomic (gcov_type* counters) +{ + if (!counters[0]) + counters[0] = __atomic_add_fetch (&function_counter, 1, MEMMODEL_RELAXED); +} #endif + #ifdef L_gcov_average_profiler /* Increase corresponding COUNTER by VALUE. FIXME: Perhaps we want to saturate up. */ @@ -296,6 +366,18 @@ __gcov_average_profiler (gcov_type *counters, gcov_type value) } #endif +#ifdef L_gcov_average_profiler_atomic +/* Increase corresponding COUNTER by VALUE. FIXME: Perhaps we want + to saturate up. Function is thread-safe. */ + +void +__gcov_average_profiler_atomic (gcov_type *counters, gcov_type value) +{ + __atomic_fetch_add (&counters[0], value, MEMMODEL_RELAXED); + __atomic_fetch_add (&counters[1], 1, MEMMODEL_RELAXED); +} +#endif + #ifdef L_gcov_ior_profiler /* Bitwise-OR VALUE into COUNTER. */ @@ -306,4 +388,15 @@ __gcov_ior_profiler (gcov_type *counters, gcov_type value) } #endif +#ifdef L_gcov_ior_profiler_atomic +/* Bitwise-OR VALUE into COUNTER. Function is thread-safe. */ + +void +__gcov_ior_profiler_atomic (gcov_type *counters, gcov_type value) +{ + __atomic_fetch_or (&counters[0], value, MEMMODEL_RELAXED); +} +#endif + + #endif /* inhibit_libc */ |