Introduce BlockFrequency analysis for BasicBlocks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133766 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/BranchProbabilityInfo.cpp b/lib/Analysis/BranchProbabilityInfo.cpp
index 15059c7..263ea2c 100644
--- a/lib/Analysis/BranchProbabilityInfo.cpp
+++ b/lib/Analysis/BranchProbabilityInfo.cpp
@@ -279,6 +279,21 @@
return Sum;
}
+uint32_t BranchProbabilityInfo::getBackSumForBlock(BasicBlock *BB) const {
+ uint32_t Sum = 0;
+
+ for (pred_iterator I = pred_begin(BB), E = pred_end(BB); I != E; ++I) {
+ BasicBlock *Pred = *I;
+ uint32_t Weight = getEdgeWeight(Pred, BB);
+ uint32_t PrevSum = Sum;
+
+ Sum += Weight;
+ assert(Sum > PrevSum); (void) PrevSum;
+ }
+
+ return Sum;
+}
+
bool BranchProbabilityInfo::isEdgeHot(BasicBlock *Src, BasicBlock *Dst) const {
// Hot probability is at least 4/5 = 80%
uint32_t Weight = getEdgeWeight(Src, Dst);
@@ -345,6 +360,15 @@
return BranchProbability(N, D);
}
+BranchProbability BranchProbabilityInfo::
+getBackEdgeProbability(BasicBlock *Src, BasicBlock *Dst) const {
+
+ uint32_t N = getEdgeWeight(Src, Dst);
+ uint32_t D = getBackSumForBlock(Dst);
+
+ return BranchProbability(N, D);
+}
+
raw_ostream &
BranchProbabilityInfo::printEdgeProbability(raw_ostream &OS, BasicBlock *Src,
BasicBlock *Dst) const {