diff options
Diffstat (limited to 'gcc/predict.c')
| -rw-r--r-- | gcc/predict.c | 26 |
1 files changed, 21 insertions, 5 deletions
diff --git a/gcc/predict.c b/gcc/predict.c index ca1a0c9..2f1cb89 100644 --- a/gcc/predict.c +++ b/gcc/predict.c @@ -237,17 +237,33 @@ probably_never_executed (struct function *fun, gcc_checking_assert (fun); if (profile_status_for_function (fun) == PROFILE_READ) { - if ((count * 4 + profile_info->runs / 2) / profile_info->runs > 0) + int unlikely_count_fraction = PARAM_VALUE (UNLIKELY_BB_COUNT_FRACTION); + if (count * unlikely_count_fraction >= profile_info->runs) return false; if (!frequency) return true; if (!ENTRY_BLOCK_PTR->frequency) return false; - if (ENTRY_BLOCK_PTR->count && ENTRY_BLOCK_PTR->count < REG_BR_PROB_BASE) + if (ENTRY_BLOCK_PTR->count) { - return (RDIV (frequency * ENTRY_BLOCK_PTR->count, - ENTRY_BLOCK_PTR->frequency) - < REG_BR_PROB_BASE / 4); + gcov_type computed_count; + /* Check for possibility of overflow, in which case entry bb count + is large enough to do the division first without losing much + precision. */ + if (ENTRY_BLOCK_PTR->count < REG_BR_PROB_BASE * REG_BR_PROB_BASE) + { + gcov_type scaled_count + = frequency * ENTRY_BLOCK_PTR->count * unlikely_count_fraction; + computed_count = RDIV (scaled_count, ENTRY_BLOCK_PTR->frequency); + } + else + { + computed_count = RDIV (ENTRY_BLOCK_PTR->count, + ENTRY_BLOCK_PTR->frequency); + computed_count *= frequency * unlikely_count_fraction; + } + if (computed_count >= profile_info->runs) + return false; } return true; } |