From 44eb49c2a191108df801977c8e3dc03466c6c02a Mon Sep 17 00:00:00 2001 From: Jakub Staszak Date: Thu, 23 Jun 2011 21:45:20 +0000 Subject: Introduce BlockFrequency analysis for BasicBlocks. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133766 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/BranchProbabilityInfo.cpp | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'lib/Analysis/BranchProbabilityInfo.cpp') 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 @@ uint32_t BranchProbabilityInfo::getSumForBlock(BasicBlock *BB) const { 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 @@ getEdgeProbability(BasicBlock *Src, BasicBlock *Dst) const { 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 { -- cgit v1.1