- LoadSDNode *LD = cast<LoadSDNode>(Node);
- Tmp1 = LegalizeOp(LD->getChain()); // Legalize the chain.
- Tmp2 = LegalizeOp(LD->getBasePtr()); // Legalize the base pointer.
-
- ISD::LoadExtType ExtType = LD->getExtensionType();
- if (ExtType == ISD::NON_EXTLOAD) {
- EVT VT = Node->getValueType(0);
- Result = SDValue(DAG.UpdateNodeOperands(Result.getNode(),
- Tmp1, Tmp2, LD->getOffset()),
- Result.getResNo());
- Tmp3 = Result.getValue(0);
- Tmp4 = Result.getValue(1);
-
- switch (TLI.getOperationAction(Node->getOpcode(), VT)) {
- default: assert(0 && "This action is not supported yet!");
- case TargetLowering::Legal:
- // If this is an unaligned load and the target doesn't support it,
- // expand it.
- if (!TLI.allowsUnalignedMemoryAccesses(LD->getMemoryVT())) {
- Type *Ty = LD->getMemoryVT().getTypeForEVT(*DAG.getContext());
- unsigned ABIAlignment = TLI.getTargetData()->getABITypeAlignment(Ty);
- if (LD->getAlignment() < ABIAlignment){
- Result = ExpandUnalignedLoad(cast<LoadSDNode>(Result.getNode()),
- DAG, TLI);
- Tmp3 = Result.getOperand(0);
- Tmp4 = Result.getOperand(1);
- Tmp3 = LegalizeOp(Tmp3);
- Tmp4 = LegalizeOp(Tmp4);
- }
- }
- break;
- case TargetLowering::Custom:
- Tmp1 = TLI.LowerOperation(Tmp3, DAG);
- if (Tmp1.getNode()) {
- Tmp3 = LegalizeOp(Tmp1);
- Tmp4 = LegalizeOp(Tmp1.getValue(1));
- }
- break;
- case TargetLowering::Promote: {
- // Only promote a load of vector type to another.
- assert(VT.isVector() && "Cannot promote this load!");
- // Change base type to a different vector type.
- EVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), VT);
-
- Tmp1 = DAG.getLoad(NVT, dl, Tmp1, Tmp2, LD->getPointerInfo(),
- LD->isVolatile(), LD->isNonTemporal(),
- LD->getAlignment());
- Tmp3 = LegalizeOp(DAG.getNode(ISD::BITCAST, dl, VT, Tmp1));
- Tmp4 = LegalizeOp(Tmp1.getValue(1));
- break;
- }
- }
- // Since loads produce two values, make sure to remember that we
- // legalized both of them.
- AddLegalizedOperand(SDValue(Node, 0), Tmp3);
- AddLegalizedOperand(SDValue(Node, 1), Tmp4);
- return Op.getResNo() ? Tmp4 : Tmp3;
- }
-
- EVT SrcVT = LD->getMemoryVT();
- unsigned SrcWidth = SrcVT.getSizeInBits();
- unsigned Alignment = LD->getAlignment();
- bool isVolatile = LD->isVolatile();
- bool isNonTemporal = LD->isNonTemporal();
-
- if (SrcWidth != SrcVT.getStoreSizeInBits() &&
- // Some targets pretend to have an i1 loading operation, and actually
- // load an i8. This trick is correct for ZEXTLOAD because the top 7
- // bits are guaranteed to be zero; it helps the optimizers understand
- // that these bits are zero. It is also useful for EXTLOAD, since it
- // tells the optimizers that those bits are undefined. It would be
- // nice to have an effective generic way of getting these benefits...
- // Until such a way is found, don't insist on promoting i1 here.
- (SrcVT != MVT::i1 ||
- TLI.getLoadExtAction(ExtType, MVT::i1) == TargetLowering::Promote)) {
- // Promote to a byte-sized load if not loading an integral number of
- // bytes. For example, promote EXTLOAD:i20 -> EXTLOAD:i24.
- unsigned NewWidth = SrcVT.getStoreSizeInBits();
- EVT NVT = EVT::getIntegerVT(*DAG.getContext(), NewWidth);
- SDValue Ch;
-
- // The extra bits are guaranteed to be zero, since we stored them that
- // way. A zext load from NVT thus automatically gives zext from SrcVT.
-
- ISD::LoadExtType NewExtType =
- ExtType == ISD::ZEXTLOAD ? ISD::ZEXTLOAD : ISD::EXTLOAD;
-
- Result = DAG.getExtLoad(NewExtType, dl, Node->getValueType(0),
- Tmp1, Tmp2, LD->getPointerInfo(),
- NVT, isVolatile, isNonTemporal, Alignment);
-
- Ch = Result.getValue(1); // The chain.
-
- if (ExtType == ISD::SEXTLOAD)
- // Having the top bits zero doesn't help when sign extending.
- Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
- Result.getValueType(),
- Result, DAG.getValueType(SrcVT));
- else if (ExtType == ISD::ZEXTLOAD || NVT == Result.getValueType())
- // All the top bits are guaranteed to be zero - inform the optimizers.
- Result = DAG.getNode(ISD::AssertZext, dl,
- Result.getValueType(), Result,
- DAG.getValueType(SrcVT));
-
- Tmp1 = LegalizeOp(Result);
- Tmp2 = LegalizeOp(Ch);
- } else if (SrcWidth & (SrcWidth - 1)) {
- // If not loading a power-of-2 number of bits, expand as two loads.
- assert(!SrcVT.isVector() && "Unsupported extload!");
- unsigned RoundWidth = 1 << Log2_32(SrcWidth);
- assert(RoundWidth < SrcWidth);
- unsigned ExtraWidth = SrcWidth - RoundWidth;
- assert(ExtraWidth < RoundWidth);
- assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
- "Load size not an integral number of bytes!");
- EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
- EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
- SDValue Lo, Hi, Ch;
- unsigned IncrementSize;
-
- if (TLI.isLittleEndian()) {
- // EXTLOAD:i24 -> ZEXTLOAD:i16 | (shl EXTLOAD@+2:i8, 16)
- // Load the bottom RoundWidth bits.
- Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0),
- Tmp1, Tmp2,
- LD->getPointerInfo(), RoundVT, isVolatile,
- isNonTemporal, Alignment);
-
- // Load the remaining ExtraWidth bits.
- IncrementSize = RoundWidth / 8;
- Tmp2 = DAG.getNode(ISD::ADD, dl, Tmp2.getValueType(), Tmp2,
- DAG.getIntPtrConstant(IncrementSize));
- Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Tmp1, Tmp2,
- LD->getPointerInfo().getWithOffset(IncrementSize),
- ExtraVT, isVolatile, isNonTemporal,
- MinAlign(Alignment, IncrementSize));
-
- // Build a factor node to remember that this load is independent of
- // the other one.
- Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
- Hi.getValue(1));
-
- // Move the top bits to the right place.
- Hi = DAG.getNode(ISD::SHL, dl, Hi.getValueType(), Hi,
- DAG.getConstant(RoundWidth,
- TLI.getShiftAmountTy(Hi.getValueType())));
-
- // Join the hi and lo parts.
- Result = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
- } else {
- // Big endian - avoid unaligned loads.
- // EXTLOAD:i24 -> (shl EXTLOAD:i16, 8) | ZEXTLOAD@+2:i8
- // Load the top RoundWidth bits.
- Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Tmp1, Tmp2,
- LD->getPointerInfo(), RoundVT, isVolatile,
- isNonTemporal, Alignment);
-
- // Load the remaining ExtraWidth bits.
- IncrementSize = RoundWidth / 8;
- Tmp2 = DAG.getNode(ISD::ADD, dl, Tmp2.getValueType(), Tmp2,
- DAG.getIntPtrConstant(IncrementSize));
- Lo = DAG.getExtLoad(ISD::ZEXTLOAD,
- dl, Node->getValueType(0), Tmp1, Tmp2,
- LD->getPointerInfo().getWithOffset(IncrementSize),
- ExtraVT, isVolatile, isNonTemporal,
- MinAlign(Alignment, IncrementSize));
-
- // Build a factor node to remember that this load is independent of
- // the other one.
- Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
- Hi.getValue(1));
-
- // Move the top bits to the right place.
- Hi = DAG.getNode(ISD::SHL, dl, Hi.getValueType(), Hi,
- DAG.getConstant(ExtraWidth,
- TLI.getShiftAmountTy(Hi.getValueType())));
-
- // Join the hi and lo parts.
- Result = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
- }
-
- Tmp1 = LegalizeOp(Result);
- Tmp2 = LegalizeOp(Ch);
- } else {
- switch (TLI.getLoadExtAction(ExtType, SrcVT)) {
- default: assert(0 && "This action is not supported yet!");
- case TargetLowering::Custom:
- isCustom = true;
- // FALLTHROUGH
- case TargetLowering::Legal:
- Result = SDValue(DAG.UpdateNodeOperands(Result.getNode(),
- Tmp1, Tmp2, LD->getOffset()),
- Result.getResNo());
- Tmp1 = Result.getValue(0);
- Tmp2 = Result.getValue(1);
-
- if (isCustom) {
- Tmp3 = TLI.LowerOperation(Result, DAG);
- if (Tmp3.getNode()) {
- Tmp1 = LegalizeOp(Tmp3);
- Tmp2 = LegalizeOp(Tmp3.getValue(1));
- }
- } else {
- // If this is an unaligned load and the target doesn't support it,
- // expand it.
- if (!TLI.allowsUnalignedMemoryAccesses(LD->getMemoryVT())) {
- Type *Ty =
- LD->getMemoryVT().getTypeForEVT(*DAG.getContext());
- unsigned ABIAlignment =
- TLI.getTargetData()->getABITypeAlignment(Ty);
- if (LD->getAlignment() < ABIAlignment){
- Result = ExpandUnalignedLoad(cast<LoadSDNode>(Result.getNode()),
- DAG, TLI);
- Tmp1 = Result.getOperand(0);
- Tmp2 = Result.getOperand(1);
- Tmp1 = LegalizeOp(Tmp1);
- Tmp2 = LegalizeOp(Tmp2);
- }
- }
- }
- break;
- case TargetLowering::Expand:
- if (!TLI.isLoadExtLegal(ISD::EXTLOAD, SrcVT) && TLI.isTypeLegal(SrcVT)) {
- SDValue Load = DAG.getLoad(SrcVT, dl, Tmp1, Tmp2,
- LD->getPointerInfo(),
- LD->isVolatile(), LD->isNonTemporal(),
- LD->getAlignment());
- unsigned ExtendOp;
- switch (ExtType) {
- case ISD::EXTLOAD:
- ExtendOp = (SrcVT.isFloatingPoint() ?
- ISD::FP_EXTEND : ISD::ANY_EXTEND);
- break;
- case ISD::SEXTLOAD: ExtendOp = ISD::SIGN_EXTEND; break;
- case ISD::ZEXTLOAD: ExtendOp = ISD::ZERO_EXTEND; break;
- default: llvm_unreachable("Unexpected extend load type!");
- }
- Result = DAG.getNode(ExtendOp, dl, Node->getValueType(0), Load);
- Tmp1 = LegalizeOp(Result); // Relegalize new nodes.
- Tmp2 = LegalizeOp(Load.getValue(1));
- break;
- }
-
- assert(!SrcVT.isVector() &&
- "Vector Loads are handled in LegalizeVectorOps");
-
- // FIXME: This does not work for vectors on most targets. Sign- and
- // zero-extend operations are currently folded into extending loads,
- // whether they are legal or not, and then we end up here without any
- // support for legalizing them.
- assert(ExtType != ISD::EXTLOAD &&
- "EXTLOAD should always be supported!");
- // Turn the unsupported load into an EXTLOAD followed by an explicit
- // zero/sign extend inreg.
- Result = DAG.getExtLoad(ISD::EXTLOAD, dl, Node->getValueType(0),
- Tmp1, Tmp2, LD->getPointerInfo(), SrcVT,
- LD->isVolatile(), LD->isNonTemporal(),
- LD->getAlignment());
- SDValue ValRes;
- if (ExtType == ISD::SEXTLOAD)
- ValRes = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
- Result.getValueType(),
- Result, DAG.getValueType(SrcVT));
- else
- ValRes = DAG.getZeroExtendInReg(Result, dl, SrcVT.getScalarType());
- Tmp1 = LegalizeOp(ValRes); // Relegalize new nodes.
- Tmp2 = LegalizeOp(Result.getValue(1)); // Relegalize new nodes.
- break;
- }
- }
-
- // Since loads produce two values, make sure to remember that we legalized
- // both of them.
- AddLegalizedOperand(SDValue(Node, 0), Tmp1);
- AddLegalizedOperand(SDValue(Node, 1), Tmp2);
- return Op.getResNo() ? Tmp2 : Tmp1;