Add a new ShuffleVectorInst::getMaskValue method.
llvm-svn: 47813
diff --git a/llvm/lib/VMCore/Instructions.cpp b/llvm/lib/VMCore/Instructions.cpp
index c0b3413..dfd3b83 100644
--- a/llvm/lib/VMCore/Instructions.cpp
+++ b/llvm/lib/VMCore/Instructions.cpp
@@ -1350,16 +1350,34 @@
bool ShuffleVectorInst::isValidOperands(const Value *V1, const Value *V2,
const Value *Mask) {
- if (!isa<VectorType>(V1->getType())) return false;
- if (V1->getType() != V2->getType()) return false;
- if (!isa<VectorType>(Mask->getType()) ||
- cast<VectorType>(Mask->getType())->getElementType() != Type::Int32Ty ||
- cast<VectorType>(Mask->getType())->getNumElements() !=
- cast<VectorType>(V1->getType())->getNumElements())
+ if (!isa<VectorType>(V1->getType()) ||
+ V1->getType() != V2->getType())
+ return false;
+
+ const VectorType *MaskTy = dyn_cast<VectorType>(Mask->getType());
+ if (!isa<Constant>(Mask) || MaskTy == 0 ||
+ MaskTy->getElementType() != Type::Int32Ty ||
+ MaskTy->getNumElements() !=
+ cast<VectorType>(V1->getType())->getNumElements())
return false;
return true;
}
+/// getMaskValue - Return the index from the shuffle mask for the specified
+/// output result. This is either -1 if the element is undef or a number less
+/// than 2*numelements.
+int ShuffleVectorInst::getMaskValue(unsigned i) const {
+ const Constant *Mask = cast<Constant>(getOperand(2));
+ if (isa<UndefValue>(Mask)) return -1;
+ if (isa<ConstantAggregateZero>(Mask)) return 0;
+ const ConstantVector *MaskCV = cast<ConstantVector>(Mask);
+ assert(i < MaskCV->getNumOperands() && "Index out of range");
+
+ if (isa<UndefValue>(MaskCV->getOperand(i)))
+ return -1;
+ return cast<ConstantInt>(MaskCV->getOperand(i))->getZExtValue();
+}
+
//===----------------------------------------------------------------------===//
// BinaryOperator Class