Revert "BlockFrequency: Saturate at 1 instead of 0 when multiplying a frequency with a branch probability."
This reverts commit r184584. Breaks PPC selfhost.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184590 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/BlockFrequency.cpp b/lib/Support/BlockFrequency.cpp
index 53bbd8a..84a993e 100644
--- a/lib/Support/BlockFrequency.cpp
+++ b/lib/Support/BlockFrequency.cpp
@@ -65,9 +65,6 @@
BlockFrequency &BlockFrequency::operator*=(const BranchProbability &Prob) {
- if (Frequency == 0)
- return *this;
-
uint32_t n = Prob.getNumerator();
uint32_t d = Prob.getDenominator();
@@ -87,15 +84,10 @@
// 64-bit.
mult96bit(Frequency, n, W);
Frequency = div96bit(W, d);
- } else {
- // Fast case.
- Frequency = mulRes / d;
+ return *this;
}
- // 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;
+ Frequency = mulRes / d;
return *this;
}