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Diffstat (limited to 'contrib/llvm/lib/Target/R600/AMDGPUISelDAGToDAG.cpp')
-rw-r--r-- | contrib/llvm/lib/Target/R600/AMDGPUISelDAGToDAG.cpp | 585 |
1 files changed, 585 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/R600/AMDGPUISelDAGToDAG.cpp b/contrib/llvm/lib/Target/R600/AMDGPUISelDAGToDAG.cpp new file mode 100644 index 0000000..a989135 --- /dev/null +++ b/contrib/llvm/lib/Target/R600/AMDGPUISelDAGToDAG.cpp @@ -0,0 +1,585 @@ +//===-- AMDILISelDAGToDAG.cpp - A dag to dag inst selector for AMDIL ------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//==-----------------------------------------------------------------------===// +// +/// \file +/// \brief Defines an instruction selector for the AMDGPU target. +// +//===----------------------------------------------------------------------===// +#include "AMDGPUInstrInfo.h" +#include "AMDGPUISelLowering.h" // For AMDGPUISD +#include "AMDGPURegisterInfo.h" +#include "R600InstrInfo.h" +#include "SIISelLowering.h" +#include "llvm/ADT/ValueMap.h" +#include "llvm/Analysis/ValueTracking.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" +#include "llvm/CodeGen/PseudoSourceValue.h" +#include "llvm/CodeGen/SelectionDAG.h" +#include "llvm/CodeGen/SelectionDAGISel.h" +#include "llvm/Support/Compiler.h" +#include <list> +#include <queue> + +using namespace llvm; + +//===----------------------------------------------------------------------===// +// Instruction Selector Implementation +//===----------------------------------------------------------------------===// + +namespace { +/// AMDGPU specific code to select AMDGPU machine instructions for +/// SelectionDAG operations. +class AMDGPUDAGToDAGISel : public SelectionDAGISel { + // Subtarget - Keep a pointer to the AMDGPU Subtarget around so that we can + // make the right decision when generating code for different targets. + const AMDGPUSubtarget &Subtarget; +public: + AMDGPUDAGToDAGISel(TargetMachine &TM); + virtual ~AMDGPUDAGToDAGISel(); + + SDNode *Select(SDNode *N); + virtual const char *getPassName() const; + virtual void PostprocessISelDAG(); + +private: + inline SDValue getSmallIPtrImm(unsigned Imm); + bool FoldOperand(SDValue &Src, SDValue &Sel, SDValue &Neg, SDValue &Abs, + const R600InstrInfo *TII); + bool FoldOperands(unsigned, const R600InstrInfo *, std::vector<SDValue> &); + bool FoldDotOperands(unsigned, const R600InstrInfo *, std::vector<SDValue> &); + + // Complex pattern selectors + bool SelectADDRParam(SDValue Addr, SDValue& R1, SDValue& R2); + bool SelectADDR(SDValue N, SDValue &R1, SDValue &R2); + bool SelectADDR64(SDValue N, SDValue &R1, SDValue &R2); + SDValue SimplifyI24(SDValue &Op); + bool SelectI24(SDValue Addr, SDValue &Op); + bool SelectU24(SDValue Addr, SDValue &Op); + + static bool checkType(const Value *ptr, unsigned int addrspace); + + static bool isGlobalStore(const StoreSDNode *N); + static bool isPrivateStore(const StoreSDNode *N); + static bool isLocalStore(const StoreSDNode *N); + static bool isRegionStore(const StoreSDNode *N); + + bool isCPLoad(const LoadSDNode *N) const; + bool isConstantLoad(const LoadSDNode *N, int cbID) const; + bool isGlobalLoad(const LoadSDNode *N) const; + bool isParamLoad(const LoadSDNode *N) const; + bool isPrivateLoad(const LoadSDNode *N) const; + bool isLocalLoad(const LoadSDNode *N) const; + bool isRegionLoad(const LoadSDNode *N) const; + + const TargetRegisterClass *getOperandRegClass(SDNode *N, unsigned OpNo) const; + bool SelectGlobalValueConstantOffset(SDValue Addr, SDValue& IntPtr); + bool SelectGlobalValueVariableOffset(SDValue Addr, + SDValue &BaseReg, SDValue& Offset); + bool SelectADDRVTX_READ(SDValue Addr, SDValue &Base, SDValue &Offset); + bool SelectADDRIndirect(SDValue Addr, SDValue &Base, SDValue &Offset); + + // Include the pieces autogenerated from the target description. +#include "AMDGPUGenDAGISel.inc" +}; +} // end anonymous namespace + +/// \brief This pass converts a legalized DAG into a AMDGPU-specific +// DAG, ready for instruction scheduling. +FunctionPass *llvm::createAMDGPUISelDag(TargetMachine &TM + ) { + return new AMDGPUDAGToDAGISel(TM); +} + +AMDGPUDAGToDAGISel::AMDGPUDAGToDAGISel(TargetMachine &TM) + : SelectionDAGISel(TM), Subtarget(TM.getSubtarget<AMDGPUSubtarget>()) { +} + +AMDGPUDAGToDAGISel::~AMDGPUDAGToDAGISel() { +} + +/// \brief Determine the register class for \p OpNo +/// \returns The register class of the virtual register that will be used for +/// the given operand number \OpNo or NULL if the register class cannot be +/// determined. +const TargetRegisterClass *AMDGPUDAGToDAGISel::getOperandRegClass(SDNode *N, + unsigned OpNo) const { + if (!N->isMachineOpcode()) { + return NULL; + } + switch (N->getMachineOpcode()) { + default: { + const MCInstrDesc &Desc = TM.getInstrInfo()->get(N->getMachineOpcode()); + unsigned OpIdx = Desc.getNumDefs() + OpNo; + if (OpIdx >= Desc.getNumOperands()) + return NULL; + int RegClass = Desc.OpInfo[OpIdx].RegClass; + if (RegClass == -1) { + return NULL; + } + return TM.getRegisterInfo()->getRegClass(RegClass); + } + case AMDGPU::REG_SEQUENCE: { + const TargetRegisterClass *SuperRC = TM.getRegisterInfo()->getRegClass( + cast<ConstantSDNode>(N->getOperand(0))->getZExtValue()); + unsigned SubRegIdx = + dyn_cast<ConstantSDNode>(N->getOperand(OpNo + 1))->getZExtValue(); + return TM.getRegisterInfo()->getSubClassWithSubReg(SuperRC, SubRegIdx); + } + } +} + +SDValue AMDGPUDAGToDAGISel::getSmallIPtrImm(unsigned int Imm) { + return CurDAG->getTargetConstant(Imm, MVT::i32); +} + +bool AMDGPUDAGToDAGISel::SelectADDRParam( + SDValue Addr, SDValue& R1, SDValue& R2) { + + if (Addr.getOpcode() == ISD::FrameIndex) { + if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(Addr)) { + R1 = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i32); + R2 = CurDAG->getTargetConstant(0, MVT::i32); + } else { + R1 = Addr; + R2 = CurDAG->getTargetConstant(0, MVT::i32); + } + } else if (Addr.getOpcode() == ISD::ADD) { + R1 = Addr.getOperand(0); + R2 = Addr.getOperand(1); + } else { + R1 = Addr; + R2 = CurDAG->getTargetConstant(0, MVT::i32); + } + return true; +} + +bool AMDGPUDAGToDAGISel::SelectADDR(SDValue Addr, SDValue& R1, SDValue& R2) { + if (Addr.getOpcode() == ISD::TargetExternalSymbol || + Addr.getOpcode() == ISD::TargetGlobalAddress) { + return false; + } + return SelectADDRParam(Addr, R1, R2); +} + + +bool AMDGPUDAGToDAGISel::SelectADDR64(SDValue Addr, SDValue& R1, SDValue& R2) { + if (Addr.getOpcode() == ISD::TargetExternalSymbol || + Addr.getOpcode() == ISD::TargetGlobalAddress) { + return false; + } + + if (Addr.getOpcode() == ISD::FrameIndex) { + if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(Addr)) { + R1 = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i64); + R2 = CurDAG->getTargetConstant(0, MVT::i64); + } else { + R1 = Addr; + R2 = CurDAG->getTargetConstant(0, MVT::i64); + } + } else if (Addr.getOpcode() == ISD::ADD) { + R1 = Addr.getOperand(0); + R2 = Addr.getOperand(1); + } else { + R1 = Addr; + R2 = CurDAG->getTargetConstant(0, MVT::i64); + } + return true; +} + +SDNode *AMDGPUDAGToDAGISel::Select(SDNode *N) { + unsigned int Opc = N->getOpcode(); + if (N->isMachineOpcode()) { + N->setNodeId(-1); + return NULL; // Already selected. + } + switch (Opc) { + default: break; + case ISD::BUILD_VECTOR: { + unsigned RegClassID; + const AMDGPUSubtarget &ST = TM.getSubtarget<AMDGPUSubtarget>(); + const AMDGPURegisterInfo *TRI = + static_cast<const AMDGPURegisterInfo*>(TM.getRegisterInfo()); + const SIRegisterInfo *SIRI = + static_cast<const SIRegisterInfo*>(TM.getRegisterInfo()); + EVT VT = N->getValueType(0); + unsigned NumVectorElts = VT.getVectorNumElements(); + assert(VT.getVectorElementType().bitsEq(MVT::i32)); + if (ST.getGeneration() >= AMDGPUSubtarget::SOUTHERN_ISLANDS) { + bool UseVReg = true; + for (SDNode::use_iterator U = N->use_begin(), E = SDNode::use_end(); + U != E; ++U) { + if (!U->isMachineOpcode()) { + continue; + } + const TargetRegisterClass *RC = getOperandRegClass(*U, U.getOperandNo()); + if (!RC) { + continue; + } + if (SIRI->isSGPRClass(RC)) { + UseVReg = false; + } + } + switch(NumVectorElts) { + case 1: RegClassID = UseVReg ? AMDGPU::VReg_32RegClassID : + AMDGPU::SReg_32RegClassID; + break; + case 2: RegClassID = UseVReg ? AMDGPU::VReg_64RegClassID : + AMDGPU::SReg_64RegClassID; + break; + case 4: RegClassID = UseVReg ? AMDGPU::VReg_128RegClassID : + AMDGPU::SReg_128RegClassID; + break; + case 8: RegClassID = UseVReg ? AMDGPU::VReg_256RegClassID : + AMDGPU::SReg_256RegClassID; + break; + case 16: RegClassID = UseVReg ? AMDGPU::VReg_512RegClassID : + AMDGPU::SReg_512RegClassID; + break; + default: llvm_unreachable("Do not know how to lower this BUILD_VECTOR"); + } + } else { + // BUILD_VECTOR was lowered into an IMPLICIT_DEF + 4 INSERT_SUBREG + // that adds a 128 bits reg copy when going through TwoAddressInstructions + // pass. We want to avoid 128 bits copies as much as possible because they + // can't be bundled by our scheduler. + switch(NumVectorElts) { + case 2: RegClassID = AMDGPU::R600_Reg64RegClassID; break; + case 4: RegClassID = AMDGPU::R600_Reg128RegClassID; break; + default: llvm_unreachable("Do not know how to lower this BUILD_VECTOR"); + } + } + + SDValue RegClass = CurDAG->getTargetConstant(RegClassID, MVT::i32); + + if (NumVectorElts == 1) { + return CurDAG->SelectNodeTo(N, AMDGPU::COPY_TO_REGCLASS, + VT.getVectorElementType(), + N->getOperand(0), RegClass); + } + + assert(NumVectorElts <= 16 && "Vectors with more than 16 elements not " + "supported yet"); + // 16 = Max Num Vector Elements + // 2 = 2 REG_SEQUENCE operands per element (value, subreg index) + // 1 = Vector Register Class + SDValue RegSeqArgs[16 * 2 + 1]; + + RegSeqArgs[0] = CurDAG->getTargetConstant(RegClassID, MVT::i32); + bool IsRegSeq = true; + for (unsigned i = 0; i < N->getNumOperands(); i++) { + // XXX: Why is this here? + if (dyn_cast<RegisterSDNode>(N->getOperand(i))) { + IsRegSeq = false; + break; + } + RegSeqArgs[1 + (2 * i)] = N->getOperand(i); + RegSeqArgs[1 + (2 * i) + 1] = + CurDAG->getTargetConstant(TRI->getSubRegFromChannel(i), MVT::i32); + } + if (!IsRegSeq) + break; + return CurDAG->SelectNodeTo(N, AMDGPU::REG_SEQUENCE, N->getVTList(), + RegSeqArgs, 2 * N->getNumOperands() + 1); + } + case ISD::BUILD_PAIR: { + SDValue RC, SubReg0, SubReg1; + const AMDGPUSubtarget &ST = TM.getSubtarget<AMDGPUSubtarget>(); + if (ST.getGeneration() <= AMDGPUSubtarget::NORTHERN_ISLANDS) { + break; + } + if (N->getValueType(0) == MVT::i128) { + RC = CurDAG->getTargetConstant(AMDGPU::SReg_128RegClassID, MVT::i32); + SubReg0 = CurDAG->getTargetConstant(AMDGPU::sub0_sub1, MVT::i32); + SubReg1 = CurDAG->getTargetConstant(AMDGPU::sub2_sub3, MVT::i32); + } else if (N->getValueType(0) == MVT::i64) { + RC = CurDAG->getTargetConstant(AMDGPU::VSrc_64RegClassID, MVT::i32); + SubReg0 = CurDAG->getTargetConstant(AMDGPU::sub0, MVT::i32); + SubReg1 = CurDAG->getTargetConstant(AMDGPU::sub1, MVT::i32); + } else { + llvm_unreachable("Unhandled value type for BUILD_PAIR"); + } + const SDValue Ops[] = { RC, N->getOperand(0), SubReg0, + N->getOperand(1), SubReg1 }; + return CurDAG->getMachineNode(TargetOpcode::REG_SEQUENCE, + SDLoc(N), N->getValueType(0), Ops); + } + case AMDGPUISD::REGISTER_LOAD: { + const AMDGPUSubtarget &ST = TM.getSubtarget<AMDGPUSubtarget>(); + if (ST.getGeneration() <= AMDGPUSubtarget::NORTHERN_ISLANDS) + break; + SDValue Addr, Offset; + + SelectADDRIndirect(N->getOperand(1), Addr, Offset); + const SDValue Ops[] = { + Addr, + Offset, + CurDAG->getTargetConstant(0, MVT::i32), + N->getOperand(0), + }; + return CurDAG->getMachineNode(AMDGPU::SI_RegisterLoad, SDLoc(N), + CurDAG->getVTList(MVT::i32, MVT::i64, MVT::Other), + Ops); + } + case AMDGPUISD::REGISTER_STORE: { + const AMDGPUSubtarget &ST = TM.getSubtarget<AMDGPUSubtarget>(); + if (ST.getGeneration() <= AMDGPUSubtarget::NORTHERN_ISLANDS) + break; + SDValue Addr, Offset; + SelectADDRIndirect(N->getOperand(2), Addr, Offset); + const SDValue Ops[] = { + N->getOperand(1), + Addr, + Offset, + CurDAG->getTargetConstant(0, MVT::i32), + N->getOperand(0), + }; + return CurDAG->getMachineNode(AMDGPU::SI_RegisterStorePseudo, SDLoc(N), + CurDAG->getVTList(MVT::Other), + Ops); + } + } + return SelectCode(N); +} + + +bool AMDGPUDAGToDAGISel::checkType(const Value *ptr, unsigned int addrspace) { + if (!ptr) { + return false; + } + Type *ptrType = ptr->getType(); + return dyn_cast<PointerType>(ptrType)->getAddressSpace() == addrspace; +} + +bool AMDGPUDAGToDAGISel::isGlobalStore(const StoreSDNode *N) { + return checkType(N->getSrcValue(), AMDGPUAS::GLOBAL_ADDRESS); +} + +bool AMDGPUDAGToDAGISel::isPrivateStore(const StoreSDNode *N) { + return (!checkType(N->getSrcValue(), AMDGPUAS::LOCAL_ADDRESS) + && !checkType(N->getSrcValue(), AMDGPUAS::GLOBAL_ADDRESS) + && !checkType(N->getSrcValue(), AMDGPUAS::REGION_ADDRESS)); +} + +bool AMDGPUDAGToDAGISel::isLocalStore(const StoreSDNode *N) { + return checkType(N->getSrcValue(), AMDGPUAS::LOCAL_ADDRESS); +} + +bool AMDGPUDAGToDAGISel::isRegionStore(const StoreSDNode *N) { + return checkType(N->getSrcValue(), AMDGPUAS::REGION_ADDRESS); +} + +bool AMDGPUDAGToDAGISel::isConstantLoad(const LoadSDNode *N, int CbId) const { + if (CbId == -1) { + return checkType(N->getSrcValue(), AMDGPUAS::CONSTANT_ADDRESS); + } + return checkType(N->getSrcValue(), AMDGPUAS::CONSTANT_BUFFER_0 + CbId); +} + +bool AMDGPUDAGToDAGISel::isGlobalLoad(const LoadSDNode *N) const { + if (N->getAddressSpace() == AMDGPUAS::CONSTANT_ADDRESS) { + const AMDGPUSubtarget &ST = TM.getSubtarget<AMDGPUSubtarget>(); + if (ST.getGeneration() < AMDGPUSubtarget::SOUTHERN_ISLANDS || + N->getMemoryVT().bitsLT(MVT::i32)) { + return true; + } + } + return checkType(N->getSrcValue(), AMDGPUAS::GLOBAL_ADDRESS); +} + +bool AMDGPUDAGToDAGISel::isParamLoad(const LoadSDNode *N) const { + return checkType(N->getSrcValue(), AMDGPUAS::PARAM_I_ADDRESS); +} + +bool AMDGPUDAGToDAGISel::isLocalLoad(const LoadSDNode *N) const { + return checkType(N->getSrcValue(), AMDGPUAS::LOCAL_ADDRESS); +} + +bool AMDGPUDAGToDAGISel::isRegionLoad(const LoadSDNode *N) const { + return checkType(N->getSrcValue(), AMDGPUAS::REGION_ADDRESS); +} + +bool AMDGPUDAGToDAGISel::isCPLoad(const LoadSDNode *N) const { + MachineMemOperand *MMO = N->getMemOperand(); + if (checkType(N->getSrcValue(), AMDGPUAS::PRIVATE_ADDRESS)) { + if (MMO) { + const Value *V = MMO->getValue(); + const PseudoSourceValue *PSV = dyn_cast<PseudoSourceValue>(V); + if (PSV && PSV == PseudoSourceValue::getConstantPool()) { + return true; + } + } + } + return false; +} + +bool AMDGPUDAGToDAGISel::isPrivateLoad(const LoadSDNode *N) const { + if (checkType(N->getSrcValue(), AMDGPUAS::PRIVATE_ADDRESS)) { + // Check to make sure we are not a constant pool load or a constant load + // that is marked as a private load + if (isCPLoad(N) || isConstantLoad(N, -1)) { + return false; + } + } + if (!checkType(N->getSrcValue(), AMDGPUAS::LOCAL_ADDRESS) + && !checkType(N->getSrcValue(), AMDGPUAS::GLOBAL_ADDRESS) + && !checkType(N->getSrcValue(), AMDGPUAS::REGION_ADDRESS) + && !checkType(N->getSrcValue(), AMDGPUAS::CONSTANT_ADDRESS) + && !checkType(N->getSrcValue(), AMDGPUAS::PARAM_D_ADDRESS) + && !checkType(N->getSrcValue(), AMDGPUAS::PARAM_I_ADDRESS)) { + return true; + } + return false; +} + +const char *AMDGPUDAGToDAGISel::getPassName() const { + return "AMDGPU DAG->DAG Pattern Instruction Selection"; +} + +#ifdef DEBUGTMP +#undef INT64_C +#endif +#undef DEBUGTMP + +//===----------------------------------------------------------------------===// +// Complex Patterns +//===----------------------------------------------------------------------===// + +bool AMDGPUDAGToDAGISel::SelectGlobalValueConstantOffset(SDValue Addr, + SDValue& IntPtr) { + if (ConstantSDNode *Cst = dyn_cast<ConstantSDNode>(Addr)) { + IntPtr = CurDAG->getIntPtrConstant(Cst->getZExtValue() / 4, true); + return true; + } + return false; +} + +bool AMDGPUDAGToDAGISel::SelectGlobalValueVariableOffset(SDValue Addr, + SDValue& BaseReg, SDValue &Offset) { + if (!dyn_cast<ConstantSDNode>(Addr)) { + BaseReg = Addr; + Offset = CurDAG->getIntPtrConstant(0, true); + return true; + } + return false; +} + +bool AMDGPUDAGToDAGISel::SelectADDRVTX_READ(SDValue Addr, SDValue &Base, + SDValue &Offset) { + ConstantSDNode * IMMOffset; + + if (Addr.getOpcode() == ISD::ADD + && (IMMOffset = dyn_cast<ConstantSDNode>(Addr.getOperand(1))) + && isInt<16>(IMMOffset->getZExtValue())) { + + Base = Addr.getOperand(0); + Offset = CurDAG->getTargetConstant(IMMOffset->getZExtValue(), MVT::i32); + return true; + // If the pointer address is constant, we can move it to the offset field. + } else if ((IMMOffset = dyn_cast<ConstantSDNode>(Addr)) + && isInt<16>(IMMOffset->getZExtValue())) { + Base = CurDAG->getCopyFromReg(CurDAG->getEntryNode(), + SDLoc(CurDAG->getEntryNode()), + AMDGPU::ZERO, MVT::i32); + Offset = CurDAG->getTargetConstant(IMMOffset->getZExtValue(), MVT::i32); + return true; + } + + // Default case, no offset + Base = Addr; + Offset = CurDAG->getTargetConstant(0, MVT::i32); + return true; +} + +bool AMDGPUDAGToDAGISel::SelectADDRIndirect(SDValue Addr, SDValue &Base, + SDValue &Offset) { + ConstantSDNode *C; + + if ((C = dyn_cast<ConstantSDNode>(Addr))) { + Base = CurDAG->getRegister(AMDGPU::INDIRECT_BASE_ADDR, MVT::i32); + Offset = CurDAG->getTargetConstant(C->getZExtValue(), MVT::i32); + } else if ((Addr.getOpcode() == ISD::ADD || Addr.getOpcode() == ISD::OR) && + (C = dyn_cast<ConstantSDNode>(Addr.getOperand(1)))) { + Base = Addr.getOperand(0); + Offset = CurDAG->getTargetConstant(C->getZExtValue(), MVT::i32); + } else { + Base = Addr; + Offset = CurDAG->getTargetConstant(0, MVT::i32); + } + + return true; +} + +SDValue AMDGPUDAGToDAGISel::SimplifyI24(SDValue &Op) { + APInt Demanded = APInt(32, 0x00FFFFFF); + APInt KnownZero, KnownOne; + TargetLowering::TargetLoweringOpt TLO(*CurDAG, true, true); + const TargetLowering *TLI = getTargetLowering(); + if (TLI->SimplifyDemandedBits(Op, Demanded, KnownZero, KnownOne, TLO)) { + CurDAG->ReplaceAllUsesWith(Op, TLO.New); + CurDAG->RepositionNode(Op.getNode(), TLO.New.getNode()); + return SimplifyI24(TLO.New); + } else { + return Op; + } +} + +bool AMDGPUDAGToDAGISel::SelectI24(SDValue Op, SDValue &I24) { + + assert(Op.getValueType() == MVT::i32); + + if (CurDAG->ComputeNumSignBits(Op) == 9) { + I24 = SimplifyI24(Op); + return true; + } + return false; +} + +bool AMDGPUDAGToDAGISel::SelectU24(SDValue Op, SDValue &U24) { + APInt KnownZero; + APInt KnownOne; + CurDAG->ComputeMaskedBits(Op, KnownZero, KnownOne); + + assert (Op.getValueType() == MVT::i32); + + // ANY_EXTEND and EXTLOAD operations can only be done on types smaller than + // i32. These smaller types are legal to use with the i24 instructions. + if ((KnownZero & APInt(KnownZero.getBitWidth(), 0xFF000000)) == 0xFF000000 || + Op.getOpcode() == ISD::ANY_EXTEND || + ISD::isEXTLoad(Op.getNode())) { + U24 = SimplifyI24(Op); + return true; + } + return false; +} + +void AMDGPUDAGToDAGISel::PostprocessISelDAG() { + const AMDGPUTargetLowering& Lowering = + (*(const AMDGPUTargetLowering*)getTargetLowering()); + bool IsModified = false; + do { + IsModified = false; + // Go over all selected nodes and try to fold them a bit more + for (SelectionDAG::allnodes_iterator I = CurDAG->allnodes_begin(), + E = CurDAG->allnodes_end(); I != E; ++I) { + + SDNode *Node = I; + + MachineSDNode *MachineNode = dyn_cast<MachineSDNode>(I); + if (!MachineNode) + continue; + + SDNode *ResNode = Lowering.PostISelFolding(MachineNode, *CurDAG); + if (ResNode != Node) { + ReplaceUses(Node, ResNode); + IsModified = true; + } + } + CurDAG->RemoveDeadNodes(); + } while (IsModified); +} |