| //===- SPIRVISelLowering.cpp - SPIR-V DAG Lowering Impl ---------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements the SPIRVTargetLowering class. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "SPIRVISelLowering.h" |
| #include "SPIRV.h" |
| #include "SPIRVInstrInfo.h" |
| #include "SPIRVRegisterBankInfo.h" |
| #include "SPIRVRegisterInfo.h" |
| #include "SPIRVSubtarget.h" |
| #include "SPIRVTargetMachine.h" |
| #include "llvm/CodeGen/MachineInstrBuilder.h" |
| #include "llvm/CodeGen/MachineRegisterInfo.h" |
| #include "llvm/IR/IntrinsicsSPIRV.h" |
| |
| #define DEBUG_TYPE "spirv-lower" |
| |
| using namespace llvm; |
| |
| unsigned SPIRVTargetLowering::getNumRegistersForCallingConv( |
| LLVMContext &Context, CallingConv::ID CC, EVT VT) const { |
| // This code avoids CallLowering fail inside getVectorTypeBreakdown |
| // on v3i1 arguments. Maybe we need to return 1 for all types. |
| // TODO: remove it once this case is supported by the default implementation. |
| if (VT.isVector() && VT.getVectorNumElements() == 3 && |
| (VT.getVectorElementType() == MVT::i1 || |
| VT.getVectorElementType() == MVT::i8)) |
| return 1; |
| if (!VT.isVector() && VT.isInteger() && VT.getSizeInBits() <= 64) |
| return 1; |
| return getNumRegisters(Context, VT); |
| } |
| |
| MVT SPIRVTargetLowering::getRegisterTypeForCallingConv(LLVMContext &Context, |
| CallingConv::ID CC, |
| EVT VT) const { |
| // This code avoids CallLowering fail inside getVectorTypeBreakdown |
| // on v3i1 arguments. Maybe we need to return i32 for all types. |
| // TODO: remove it once this case is supported by the default implementation. |
| if (VT.isVector() && VT.getVectorNumElements() == 3) { |
| if (VT.getVectorElementType() == MVT::i1) |
| return MVT::v4i1; |
| else if (VT.getVectorElementType() == MVT::i8) |
| return MVT::v4i8; |
| } |
| return getRegisterType(Context, VT); |
| } |
| |
| bool SPIRVTargetLowering::getTgtMemIntrinsic(IntrinsicInfo &Info, |
| const CallInst &I, |
| MachineFunction &MF, |
| unsigned Intrinsic) const { |
| unsigned AlignIdx = 3; |
| switch (Intrinsic) { |
| case Intrinsic::spv_load: |
| AlignIdx = 2; |
| [[fallthrough]]; |
| case Intrinsic::spv_store: { |
| if (I.getNumOperands() >= AlignIdx + 1) { |
| auto *AlignOp = cast<ConstantInt>(I.getOperand(AlignIdx)); |
| Info.align = Align(AlignOp->getZExtValue()); |
| } |
| Info.flags = static_cast<MachineMemOperand::Flags>( |
| cast<ConstantInt>(I.getOperand(AlignIdx - 1))->getZExtValue()); |
| Info.memVT = MVT::i64; |
| // TODO: take into account opaque pointers (don't use getElementType). |
| // MVT::getVT(PtrTy->getElementType()); |
| return true; |
| break; |
| } |
| default: |
| break; |
| } |
| return false; |
| } |
| |
| // Insert a bitcast before the instruction to keep SPIR-V code valid |
| // when there is a type mismatch between results and operand types. |
| static void validatePtrTypes(const SPIRVSubtarget &STI, |
| MachineRegisterInfo *MRI, SPIRVGlobalRegistry &GR, |
| MachineInstr &I, unsigned OpIdx, |
| SPIRVType *ResType, const Type *ResTy = nullptr) { |
| // Get operand type |
| MachineFunction *MF = I.getParent()->getParent(); |
| Register OpReg = I.getOperand(OpIdx).getReg(); |
| SPIRVType *TypeInst = MRI->getVRegDef(OpReg); |
| Register OpTypeReg = |
| TypeInst && TypeInst->getOpcode() == SPIRV::OpFunctionParameter |
| ? TypeInst->getOperand(1).getReg() |
| : OpReg; |
| SPIRVType *OpType = GR.getSPIRVTypeForVReg(OpTypeReg, MF); |
| if (!ResType || !OpType || OpType->getOpcode() != SPIRV::OpTypePointer) |
| return; |
| // Get operand's pointee type |
| Register ElemTypeReg = OpType->getOperand(2).getReg(); |
| SPIRVType *ElemType = GR.getSPIRVTypeForVReg(ElemTypeReg, MF); |
| if (!ElemType) |
| return; |
| // Check if we need a bitcast to make a statement valid |
| bool IsSameMF = MF == ResType->getParent()->getParent(); |
| bool IsEqualTypes = IsSameMF ? ElemType == ResType |
| : GR.getTypeForSPIRVType(ElemType) == ResTy; |
| if (IsEqualTypes) |
| return; |
| // There is a type mismatch between results and operand types |
| // and we insert a bitcast before the instruction to keep SPIR-V code valid |
| SPIRV::StorageClass::StorageClass SC = |
| static_cast<SPIRV::StorageClass::StorageClass>( |
| OpType->getOperand(1).getImm()); |
| MachineIRBuilder MIB(I); |
| SPIRVType *NewBaseType = |
| IsSameMF ? ResType |
| : GR.getOrCreateSPIRVType( |
| ResTy, MIB, SPIRV::AccessQualifier::ReadWrite, false); |
| SPIRVType *NewPtrType = GR.getOrCreateSPIRVPointerType(NewBaseType, MIB, SC); |
| if (!GR.isBitcastCompatible(NewPtrType, OpType)) |
| report_fatal_error( |
| "insert validation bitcast: incompatible result and operand types"); |
| Register NewReg = MRI->createGenericVirtualRegister(LLT::scalar(32)); |
| bool Res = MIB.buildInstr(SPIRV::OpBitcast) |
| .addDef(NewReg) |
| .addUse(GR.getSPIRVTypeID(NewPtrType)) |
| .addUse(OpReg) |
| .constrainAllUses(*STI.getInstrInfo(), *STI.getRegisterInfo(), |
| *STI.getRegBankInfo()); |
| if (!Res) |
| report_fatal_error("insert validation bitcast: cannot constrain all uses"); |
| MRI->setRegClass(NewReg, &SPIRV::IDRegClass); |
| GR.assignSPIRVTypeToVReg(NewPtrType, NewReg, MIB.getMF()); |
| I.getOperand(OpIdx).setReg(NewReg); |
| } |
| |
| // Insert a bitcast before the function call instruction to keep SPIR-V code |
| // valid when there is a type mismatch between actual and expected types of an |
| // argument: |
| // %formal = OpFunctionParameter %formal_type |
| // ... |
| // %res = OpFunctionCall %ty %fun %actual ... |
| // implies that %actual is of %formal_type, and in case of opaque pointers. |
| // We may need to insert a bitcast to ensure this. |
| void validateFunCallMachineDef(const SPIRVSubtarget &STI, |
| MachineRegisterInfo *DefMRI, |
| MachineRegisterInfo *CallMRI, |
| SPIRVGlobalRegistry &GR, MachineInstr &FunCall, |
| MachineInstr *FunDef) { |
| if (FunDef->getOpcode() != SPIRV::OpFunction) |
| return; |
| unsigned OpIdx = 3; |
| for (FunDef = FunDef->getNextNode(); |
| FunDef && FunDef->getOpcode() == SPIRV::OpFunctionParameter && |
| OpIdx < FunCall.getNumOperands(); |
| FunDef = FunDef->getNextNode(), OpIdx++) { |
| SPIRVType *DefPtrType = DefMRI->getVRegDef(FunDef->getOperand(1).getReg()); |
| SPIRVType *DefElemType = |
| DefPtrType && DefPtrType->getOpcode() == SPIRV::OpTypePointer |
| ? GR.getSPIRVTypeForVReg(DefPtrType->getOperand(2).getReg(), |
| DefPtrType->getParent()->getParent()) |
| : nullptr; |
| if (DefElemType) { |
| const Type *DefElemTy = GR.getTypeForSPIRVType(DefElemType); |
| // validatePtrTypes() works in the context if the call site |
| // When we process historical records about forward calls |
| // we need to switch context to the (forward) call site and |
| // then restore it back to the current machine function. |
| MachineFunction *CurMF = |
| GR.setCurrentFunc(*FunCall.getParent()->getParent()); |
| validatePtrTypes(STI, CallMRI, GR, FunCall, OpIdx, DefElemType, |
| DefElemTy); |
| GR.setCurrentFunc(*CurMF); |
| } |
| } |
| } |
| |
| // Ensure there is no mismatch between actual and expected arg types: calls |
| // with a processed definition. Return Function pointer if it's a forward |
| // call (ahead of definition), and nullptr otherwise. |
| const Function *validateFunCall(const SPIRVSubtarget &STI, |
| MachineRegisterInfo *CallMRI, |
| SPIRVGlobalRegistry &GR, |
| MachineInstr &FunCall) { |
| const GlobalValue *GV = FunCall.getOperand(2).getGlobal(); |
| const Function *F = dyn_cast<Function>(GV); |
| MachineInstr *FunDef = |
| const_cast<MachineInstr *>(GR.getFunctionDefinition(F)); |
| if (!FunDef) |
| return F; |
| MachineRegisterInfo *DefMRI = &FunDef->getParent()->getParent()->getRegInfo(); |
| validateFunCallMachineDef(STI, DefMRI, CallMRI, GR, FunCall, FunDef); |
| return nullptr; |
| } |
| |
| // Ensure there is no mismatch between actual and expected arg types: calls |
| // ahead of a processed definition. |
| void validateForwardCalls(const SPIRVSubtarget &STI, |
| MachineRegisterInfo *DefMRI, SPIRVGlobalRegistry &GR, |
| MachineInstr &FunDef) { |
| const Function *F = GR.getFunctionByDefinition(&FunDef); |
| if (SmallPtrSet<MachineInstr *, 8> *FwdCalls = GR.getForwardCalls(F)) |
| for (MachineInstr *FunCall : *FwdCalls) { |
| MachineRegisterInfo *CallMRI = |
| &FunCall->getParent()->getParent()->getRegInfo(); |
| validateFunCallMachineDef(STI, DefMRI, CallMRI, GR, *FunCall, &FunDef); |
| } |
| } |
| |
| // Validation of an access chain. |
| void validateAccessChain(const SPIRVSubtarget &STI, MachineRegisterInfo *MRI, |
| SPIRVGlobalRegistry &GR, MachineInstr &I) { |
| SPIRVType *BaseTypeInst = GR.getSPIRVTypeForVReg(I.getOperand(0).getReg()); |
| if (BaseTypeInst && BaseTypeInst->getOpcode() == SPIRV::OpTypePointer) { |
| SPIRVType *BaseElemType = |
| GR.getSPIRVTypeForVReg(BaseTypeInst->getOperand(2).getReg()); |
| validatePtrTypes(STI, MRI, GR, I, 2, BaseElemType); |
| } |
| } |
| |
| // TODO: the logic of inserting additional bitcast's is to be moved |
| // to pre-IRTranslation passes eventually |
| void SPIRVTargetLowering::finalizeLowering(MachineFunction &MF) const { |
| // finalizeLowering() is called twice (see GlobalISel/InstructionSelect.cpp) |
| // We'd like to avoid the needless second processing pass. |
| if (ProcessedMF.find(&MF) != ProcessedMF.end()) |
| return; |
| |
| MachineRegisterInfo *MRI = &MF.getRegInfo(); |
| SPIRVGlobalRegistry &GR = *STI.getSPIRVGlobalRegistry(); |
| GR.setCurrentFunc(MF); |
| for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I) { |
| MachineBasicBlock *MBB = &*I; |
| for (MachineBasicBlock::iterator MBBI = MBB->begin(), MBBE = MBB->end(); |
| MBBI != MBBE;) { |
| MachineInstr &MI = *MBBI++; |
| switch (MI.getOpcode()) { |
| case SPIRV::OpAtomicLoad: |
| case SPIRV::OpAtomicExchange: |
| case SPIRV::OpAtomicCompareExchange: |
| case SPIRV::OpAtomicCompareExchangeWeak: |
| case SPIRV::OpAtomicIIncrement: |
| case SPIRV::OpAtomicIDecrement: |
| case SPIRV::OpAtomicIAdd: |
| case SPIRV::OpAtomicISub: |
| case SPIRV::OpAtomicSMin: |
| case SPIRV::OpAtomicUMin: |
| case SPIRV::OpAtomicSMax: |
| case SPIRV::OpAtomicUMax: |
| case SPIRV::OpAtomicAnd: |
| case SPIRV::OpAtomicOr: |
| case SPIRV::OpAtomicXor: |
| // for the above listed instructions |
| // OpAtomicXXX <ResType>, ptr %Op, ... |
| // implies that %Op is a pointer to <ResType> |
| case SPIRV::OpLoad: |
| // OpLoad <ResType>, ptr %Op implies that %Op is a pointer to <ResType> |
| validatePtrTypes(STI, MRI, GR, MI, 2, |
| GR.getSPIRVTypeForVReg(MI.getOperand(0).getReg())); |
| break; |
| case SPIRV::OpAtomicStore: |
| // OpAtomicStore ptr %Op, <Scope>, <Mem>, <Obj> |
| // implies that %Op points to the <Obj>'s type |
| validatePtrTypes(STI, MRI, GR, MI, 0, |
| GR.getSPIRVTypeForVReg(MI.getOperand(3).getReg())); |
| break; |
| case SPIRV::OpStore: |
| // OpStore ptr %Op, <Obj> implies that %Op points to the <Obj>'s type |
| validatePtrTypes(STI, MRI, GR, MI, 0, |
| GR.getSPIRVTypeForVReg(MI.getOperand(1).getReg())); |
| break; |
| case SPIRV::OpPtrCastToGeneric: |
| validateAccessChain(STI, MRI, GR, MI); |
| break; |
| case SPIRV::OpInBoundsPtrAccessChain: |
| if (MI.getNumOperands() == 4) |
| validateAccessChain(STI, MRI, GR, MI); |
| break; |
| |
| case SPIRV::OpFunctionCall: |
| // ensure there is no mismatch between actual and expected arg types: |
| // calls with a processed definition |
| if (MI.getNumOperands() > 3) |
| if (const Function *F = validateFunCall(STI, MRI, GR, MI)) |
| GR.addForwardCall(F, &MI); |
| break; |
| case SPIRV::OpFunction: |
| // ensure there is no mismatch between actual and expected arg types: |
| // calls ahead of a processed definition |
| validateForwardCalls(STI, MRI, GR, MI); |
| break; |
| |
| // ensure that LLVM IR bitwise instructions result in logical SPIR-V |
| // instructions when applied to bool type |
| case SPIRV::OpBitwiseOrS: |
| case SPIRV::OpBitwiseOrV: |
| if (GR.isScalarOrVectorOfType(MI.getOperand(1).getReg(), |
| SPIRV::OpTypeBool)) |
| MI.setDesc(STI.getInstrInfo()->get(SPIRV::OpLogicalOr)); |
| break; |
| case SPIRV::OpBitwiseAndS: |
| case SPIRV::OpBitwiseAndV: |
| if (GR.isScalarOrVectorOfType(MI.getOperand(1).getReg(), |
| SPIRV::OpTypeBool)) |
| MI.setDesc(STI.getInstrInfo()->get(SPIRV::OpLogicalAnd)); |
| break; |
| case SPIRV::OpBitwiseXorS: |
| case SPIRV::OpBitwiseXorV: |
| if (GR.isScalarOrVectorOfType(MI.getOperand(1).getReg(), |
| SPIRV::OpTypeBool)) |
| MI.setDesc(STI.getInstrInfo()->get(SPIRV::OpLogicalNotEqual)); |
| break; |
| case SPIRV::OpConstantI: { |
| SPIRVType *Type = GR.getSPIRVTypeForVReg(MI.getOperand(1).getReg()); |
| if (Type->getOpcode() != SPIRV::OpTypeInt && MI.getOperand(2).isImm() && |
| MI.getOperand(2).getImm() == 0) { |
| // Validate the null constant of a target extension type |
| MI.setDesc(STI.getInstrInfo()->get(SPIRV::OpConstantNull)); |
| for (unsigned i = MI.getNumOperands() - 1; i > 1; --i) |
| MI.removeOperand(i); |
| } |
| } break; |
| } |
| } |
| } |
| ProcessedMF.insert(&MF); |
| TargetLowering::finalizeLowering(MF); |
| } |
