diff options
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 1c4bceaef4..590e0d9d97 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -6959,12 +6959,23 @@ static bool CollectSingleShuffleElements(Value *V, Value *LHS, Value *RHS, Value *ScalarOp = IEI->getOperand(1); Value *IdxOp = IEI->getOperand(2); - if (ExtractElementInst *EI = dyn_cast<ExtractElementInst>(ScalarOp)) { - if (isa<ConstantInt>(EI->getOperand(1)) && isa<ConstantInt>(IdxOp) && + if (!isa<ConstantInt>(IdxOp)) + return false; + unsigned InsertedIdx = cast<ConstantInt>(IdxOp)->getRawValue(); + + if (isa<UndefValue>(ScalarOp)) { // inserting undef into vector. + // Okay, we can handle this if the vector we are insertinting into is + // transitively ok. + if (CollectSingleShuffleElements(VecOp, LHS, RHS, Mask)) { + // If so, update the mask to reflect the inserted undef. + Mask[InsertedIdx] = UndefValue::get(Type::UIntTy); + return true; + } + } else if (ExtractElementInst *EI = dyn_cast<ExtractElementInst>(ScalarOp)){ + if (isa<ConstantInt>(EI->getOperand(1)) && EI->getOperand(0)->getType() == V->getType()) { unsigned ExtractedIdx = cast<ConstantInt>(EI->getOperand(1))->getRawValue(); - unsigned InsertedIdx = cast<ConstantInt>(IdxOp)->getRawValue(); // This must be extracting from either LHS or RHS. if (EI->getOperand(0) == LHS || EI->getOperand(0) == RHS) { |