diff options
Diffstat (limited to 'llvm/lib/Transforms/Utils/SimplifyCFG.cpp')
| -rw-r--r-- | llvm/lib/Transforms/Utils/SimplifyCFG.cpp | 32 |
1 files changed, 26 insertions, 6 deletions
diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp index 3efb89a4d7f..daa576cfbdc 100644 --- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp @@ -2027,6 +2027,24 @@ static bool SimplifyCondBranchToTwoReturns(BranchInst *BI, return true; } +/// ExtractBranchMetadata - Given a conditional BranchInstruction, retrieve the +/// probabilities of the branch taking each edge. Fills in the two APInt +/// parameters and return true, or returns false if no or invalid metadata was +/// found. +static bool ExtractBranchMetadata(BranchInst *BI, + uint64_t &ProbTrue, uint64_t &ProbFalse) { + assert(BI->isConditional() && + "Looking for probabilities on unconditional branch?"); + MDNode *ProfileData = BI->getMetadata(LLVMContext::MD_prof); + if (!ProfileData || ProfileData->getNumOperands() != 3) return false; + ConstantInt *CITrue = dyn_cast<ConstantInt>(ProfileData->getOperand(1)); + ConstantInt *CIFalse = dyn_cast<ConstantInt>(ProfileData->getOperand(2)); + if (!CITrue || !CIFalse) return false; + ProbTrue = CITrue->getValue().getZExtValue(); + ProbFalse = CIFalse->getValue().getZExtValue(); + return true; +} + /// checkCSEInPredecessor - Return true if the given instruction is available /// in its predecessor block. If yes, the instruction will be removed. /// @@ -2232,10 +2250,10 @@ bool llvm::FoldBranchToCommonDest(BranchInst *BI, const DataLayout *DL, PBI->setCondition(NewCond); uint64_t PredTrueWeight, PredFalseWeight, SuccTrueWeight, SuccFalseWeight; - bool PredHasWeights = - PBI->getBranchWeights(PredTrueWeight, PredFalseWeight); - bool SuccHasWeights = - BI->getBranchWeights(SuccTrueWeight, SuccFalseWeight); + bool PredHasWeights = ExtractBranchMetadata(PBI, PredTrueWeight, + PredFalseWeight); + bool SuccHasWeights = ExtractBranchMetadata(BI, SuccTrueWeight, + SuccFalseWeight); SmallVector<uint64_t, 8> NewWeights; if (PBI->getSuccessor(0) == BB) { @@ -2505,8 +2523,10 @@ static bool SimplifyCondBranchToCondBranch(BranchInst *PBI, BranchInst *BI) { // Update branch weight for PBI. uint64_t PredTrueWeight, PredFalseWeight, SuccTrueWeight, SuccFalseWeight; - bool PredHasWeights = PBI->getBranchWeights(PredTrueWeight, PredFalseWeight); - bool SuccHasWeights = BI->getBranchWeights(SuccTrueWeight, SuccFalseWeight); + bool PredHasWeights = ExtractBranchMetadata(PBI, PredTrueWeight, + PredFalseWeight); + bool SuccHasWeights = ExtractBranchMetadata(BI, SuccTrueWeight, + SuccFalseWeight); if (PredHasWeights && SuccHasWeights) { uint64_t PredCommon = PBIOp ? PredFalseWeight : PredTrueWeight; uint64_t PredOther = PBIOp ?PredTrueWeight : PredFalseWeight; |
