unsigned NumElems = Node->getNumOperands();
bool isOnlyLowElement = true;
SDOperand SplatValue = Node->getOperand(0);
+
+ // FIXME: it would be far nicer to change this into map<SDOperand,uint64_t>
+ // and use a bitmask instead of a list of elements.
std::map<SDOperand, std::vector<unsigned> > Values;
Values[SplatValue].push_back(0);
bool isConstant = true;
// If there are only two unique elements, we may be able to turn this into a
// vector shuffle.
if (Values.size() == 2) {
+ // Get the two values in deterministic order.
+ SDOperand Val1 = Node->getOperand(1);
+ SDOperand Val2;
+ std::map<SDOperand, std::vector<unsigned> >::iterator MI = Values.begin();
+ if (MI->first != Val1)
+ Val2 = MI->first;
+ else
+ Val2 = (++MI)->first;
+
+ // If Val1 is an undef, make sure end ends up as Val2, to ensure that our
+ // vector shuffle has the undef vector on the RHS.
+ if (Val1.getOpcode() == ISD::UNDEF)
+ std::swap(Val1, Val2);
+
// Build the shuffle constant vector: e.g. <0, 4, 0, 4>
- MVT::ValueType MaskVT =
- MVT::getIntVectorWithNumElements(NumElems);
+ MVT::ValueType MaskVT = MVT::getIntVectorWithNumElements(NumElems);
+ MVT::ValueType MaskEltVT = MVT::getVectorElementType(MaskVT);
std::vector<SDOperand> MaskVec(NumElems);
- unsigned i = 0;
- for (std::map<SDOperand,std::vector<unsigned> >::iterator I=Values.begin(),
- E = Values.end(); I != E; ++I) {
- for (std::vector<unsigned>::iterator II = I->second.begin(),
- EE = I->second.end(); II != EE; ++II)
- MaskVec[*II] = DAG.getConstant(i, MVT::getVectorElementType(MaskVT));
- i += NumElems;
- }
+
+ // Set elements of the shuffle mask for Val1.
+ std::vector<unsigned> &Val1Elts = Values[Val1];
+ for (unsigned i = 0, e = Val1Elts.size(); i != e; ++i)
+ MaskVec[Val1Elts[i]] = DAG.getConstant(0, MaskEltVT);
+
+ // Set elements of the shuffle mask for Val2.
+ std::vector<unsigned> &Val2Elts = Values[Val2];
+ for (unsigned i = 0, e = Val2Elts.size(); i != e; ++i)
+ if (Val2.getOpcode() != ISD::UNDEF)
+ MaskVec[Val2Elts[i]] = DAG.getConstant(NumElems, MaskEltVT);
+ else
+ MaskVec[Val2Elts[i]] = DAG.getNode(ISD::UNDEF, MaskEltVT);
+
SDOperand ShuffleMask = DAG.getNode(ISD::BUILD_VECTOR, MaskVT,
&MaskVec[0], MaskVec.size());
- // If the target supports VECTOR_SHUFFLE and this shuffle mask, use it.
+ // If the target supports SCALAR_TO_VECTOR and this shuffle mask, use it.
if (TLI.isOperationLegal(ISD::SCALAR_TO_VECTOR, Node->getValueType(0)) &&
isShuffleLegal(Node->getValueType(0), ShuffleMask)) {
- SmallVector<SDOperand, 8> Ops;
- for(std::map<SDOperand,std::vector<unsigned> >::iterator I=Values.begin(),
- E = Values.end(); I != E; ++I) {
- SDOperand Op = DAG.getNode(ISD::SCALAR_TO_VECTOR, Node->getValueType(0),
- I->first);
- Ops.push_back(Op);
- }
- Ops.push_back(ShuffleMask);
+ Val1 = DAG.getNode(ISD::SCALAR_TO_VECTOR, Node->getValueType(0), Val1);
+ Val2 = DAG.getNode(ISD::SCALAR_TO_VECTOR, Node->getValueType(0), Val2);
+ SDOperand Ops[] = { Val1, Val2, ShuffleMask };
// Return shuffle(LoValVec, HiValVec, <0,1,0,1>)
- return DAG.getNode(ISD::VECTOR_SHUFFLE, Node->getValueType(0),
- &Ops[0], Ops.size());
+ return DAG.getNode(ISD::VECTOR_SHUFFLE, Node->getValueType(0), Ops, 3);
}
}