1 files changed, 16 insertions, 23 deletions
diff --git a/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp b/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
index 096faad..a072ba2 100644
--- a/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
+++ b/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
@@ -29,6 +29,7 @@
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/MDBuilder.h"
 #include "llvm/IR/PassManager.h"
+#include "llvm/IR/ProfDataUtils.h"
 #include "llvm/InitializePasses.h"
 #include "llvm/Support/BranchProbability.h"
 #include "llvm/Support/CommandLine.h"
@@ -575,32 +576,26 @@ checkHoistValue(Value *V, Instruction *InsertPoint, DominatorTree &DT,
   return true;
 }
 
-// Returns true and sets the true probability and false probability of an
-// MD_prof metadata if it's well-formed.
-static bool checkMDProf(MDNode *MD, BranchProbability &TrueProb,
-                        BranchProbability &FalseProb) {
-  if (!MD) return false;
-  MDString *MDName = cast<MDString>(MD->getOperand(0));
-  if (MDName->getString() != "branch_weights" ||
-      MD->getNumOperands() != 3)
+// Constructs the true and false branch probabilities if the the instruction has
+// valid branch weights. Returns true when this was successful, false otherwise.
+static bool extractBranchProbabilities(Instruction *I,
+                                       BranchProbability &TrueProb,
+                                       BranchProbability &FalseProb) {
+  uint64_t TrueWeight;
+  uint64_t FalseWeight;
+  if (!extractBranchWeights(*I, TrueWeight, FalseWeight))
     return false;
-  ConstantInt *TrueWeight = mdconst::extract<ConstantInt>(MD->getOperand(1));
-  ConstantInt *FalseWeight = mdconst::extract<ConstantInt>(MD->getOperand(2));
-  if (!TrueWeight || !FalseWeight)
-    return false;
-  uint64_t TrueWt = TrueWeight->getValue().getZExtValue();
-  uint64_t FalseWt = FalseWeight->getValue().getZExtValue();
-  uint64_t SumWt = TrueWt + FalseWt;
+  uint64_t SumWeight = TrueWeight + FalseWeight;
 
-  assert(SumWt >= TrueWt && SumWt >= FalseWt &&
+  assert(SumWeight >= TrueWeight && SumWeight >= FalseWeight &&
          "Overflow calculating branch probabilities.");
 
   // Guard against 0-to-0 branch weights to avoid a division-by-zero crash.
-  if (SumWt == 0)
+  if (SumWeight == 0)
     return false;
 
-  TrueProb = BranchProbability::getBranchProbability(TrueWt, SumWt);
-  FalseProb = BranchProbability::getBranchProbability(FalseWt, SumWt);
+  TrueProb = BranchProbability::getBranchProbability(TrueWeight, SumWeight);
+  FalseProb = BranchProbability::getBranchProbability(FalseWeight, SumWeight);
   return true;
 }
 
@@ -639,8 +634,7 @@ static bool checkBiasedBranch(BranchInst *BI, Region *R,
   if (!BI->isConditional())
     return false;
   BranchProbability ThenProb, ElseProb;
-  if (!checkMDProf(BI->getMetadata(LLVMContext::MD_prof),
-                   ThenProb, ElseProb))
+  if (!extractBranchProbabilities(BI, ThenProb, ElseProb))
     return false;
   BasicBlock *IfThen = BI->getSuccessor(0);
   BasicBlock *IfElse = BI->getSuccessor(1);
@@ -669,8 +663,7 @@ static bool checkBiasedSelect(
     DenseSet<SelectInst *> &FalseBiasedSelectsGlobal,
     DenseMap<SelectInst *, BranchProbability> &SelectBiasMap) {
   BranchProbability TrueProb, FalseProb;
-  if (!checkMDProf(SI->getMetadata(LLVMContext::MD_prof),
-                   TrueProb, FalseProb))
+  if (!extractBranchProbabilities(SI, TrueProb, FalseProb))
     return false;
   CHR_DEBUG(dbgs() << "SI " << *SI << " ");
   CHR_DEBUG(dbgs() << "TrueProb " << TrueProb << " ");