+/// GetSplitDestVTs - Compute the VTs needed for the low/hi parts of a type
+/// which is split (or expanded) into two not necessarily identical pieces.
+std::pair<EVT, EVT> SelectionDAG::GetSplitDestVTs(const EVT &VT) const {
+ // Currently all types are split in half.
+ EVT LoVT, HiVT;
+ if (!VT.isVector()) {
+ LoVT = HiVT = TLI->getTypeToTransformTo(*getContext(), VT);
+ } else {
+ unsigned NumElements = VT.getVectorNumElements();
+ assert(!(NumElements & 1) && "Splitting vector, but not in half!");
+ LoVT = HiVT = EVT::getVectorVT(*getContext(), VT.getVectorElementType(),
+ NumElements/2);
+ }
+ return std::make_pair(LoVT, HiVT);
+}
+
+/// SplitVector - Split the vector with EXTRACT_SUBVECTOR and return the
+/// low/high part.
+std::pair<SDValue, SDValue>
+SelectionDAG::SplitVector(const SDValue &N, const SDLoc &DL, const EVT &LoVT,
+ const EVT &HiVT) {
+ assert(LoVT.getVectorNumElements() + HiVT.getVectorNumElements() <=
+ N.getValueType().getVectorNumElements() &&
+ "More vector elements requested than available!");
+ SDValue Lo, Hi;
+ Lo = getNode(ISD::EXTRACT_SUBVECTOR, DL, LoVT, N,
+ getConstant(0, TLI->getVectorIdxTy()));
+ Hi = getNode(ISD::EXTRACT_SUBVECTOR, DL, HiVT, N,
+ getConstant(LoVT.getVectorNumElements(), TLI->getVectorIdxTy()));
+ return std::make_pair(Lo, Hi);
+}
+