diff options
Diffstat (limited to 'lib')
-rw-r--r-- | lib/Support/BlockFrequency.cpp | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/lib/Support/BlockFrequency.cpp b/lib/Support/BlockFrequency.cpp index 84a993e3e5..53bbd8ad12 100644 --- a/lib/Support/BlockFrequency.cpp +++ b/lib/Support/BlockFrequency.cpp @@ -65,6 +65,9 @@ uint64_t div96bit(uint64_t W[2], uint32_t D) { BlockFrequency &BlockFrequency::operator*=(const BranchProbability &Prob) { + if (Frequency == 0) + return *this; + uint32_t n = Prob.getNumerator(); uint32_t d = Prob.getDenominator(); @@ -84,10 +87,15 @@ BlockFrequency &BlockFrequency::operator*=(const BranchProbability &Prob) { // 64-bit. mult96bit(Frequency, n, W); Frequency = div96bit(W, d); - return *this; + } else { + // Fast case. + Frequency = mulRes / d; } - Frequency = mulRes / d; + // Limit the result to 1; 0 is a sentinel value. This keeps BlockFrequencyInfo + // from getting stuck at zero frequencies just because a value became too + // small to be represented as a BlockFrequency. + Frequency = (n == 0 || Frequency != 0) ? Frequency : 1; return *this; } |