Files
clang-p2996/llvm/lib/Target/SPIRV/SPIRVISelLowering.cpp
Vyacheslav Levytskyy ebdadcfeb9 [SPIR-V] Improve correctness of emitted MIR between passes for branching instructions (#106966)
This PR improves correctness of emitted MIR between passes for branching
instructions and thus increase number of passing tests when expensive
checks are on. Specifically, we address here such issues with machine
verifier as:
* fix switch generation: generate correct successors and undo the
"address taken" status to reflect that a successor doesn't actually
correspond to an IR-level basic block;
* fix incorrect definition of OpBranch and OpBranchConditional in
TableGen (SPIRVInstrInfo.td) to set isBarrier status properly and set a
correct type of virtual registers;
* fix a case when Phi refers to a type definition that goes after the
Phi instruction, so that the virtual register definition of the type
doesn't dominate all uses.

This PR decrease number of failing tests under expensive checks from 56
to 50.
2024-09-03 19:02:03 +02:00

481 lines
21 KiB
C++

//===- 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;
}
std::pair<unsigned, const TargetRegisterClass *>
SPIRVTargetLowering::getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
StringRef Constraint,
MVT VT) const {
const TargetRegisterClass *RC = nullptr;
if (Constraint.starts_with("{"))
return std::make_pair(0u, RC);
if (VT.isFloatingPoint())
RC = VT.isVector() ? &SPIRV::vfIDRegClass : &SPIRV::fIDRegClass;
else if (VT.isInteger())
RC = VT.isVector() ? &SPIRV::vIDRegClass : &SPIRV::iIDRegClass;
else
RC = &SPIRV::iIDRegClass;
return std::make_pair(0u, RC);
}
inline Register getTypeReg(MachineRegisterInfo *MRI, Register OpReg) {
SPIRVType *TypeInst = MRI->getVRegDef(OpReg);
return TypeInst && TypeInst->getOpcode() == SPIRV::OpFunctionParameter
? TypeInst->getOperand(1).getReg()
: OpReg;
}
static void doInsertBitcast(const SPIRVSubtarget &STI, MachineRegisterInfo *MRI,
SPIRVGlobalRegistry &GR, MachineInstr &I,
Register OpReg, unsigned OpIdx,
SPIRVType *NewPtrType) {
Register NewReg = MRI->createGenericVirtualRegister(LLT::scalar(64));
MachineIRBuilder MIB(I);
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::iIDRegClass);
GR.assignSPIRVTypeToVReg(NewPtrType, NewReg, MIB.getMF());
I.getOperand(OpIdx).setReg(NewReg);
}
static SPIRVType *createNewPtrType(SPIRVGlobalRegistry &GR, MachineInstr &I,
SPIRVType *OpType, bool ReuseType,
bool EmitIR, SPIRVType *ResType,
const Type *ResTy) {
SPIRV::StorageClass::StorageClass SC =
static_cast<SPIRV::StorageClass::StorageClass>(
OpType->getOperand(1).getImm());
MachineIRBuilder MIB(I);
SPIRVType *NewBaseType =
ReuseType ? ResType
: GR.getOrCreateSPIRVType(
ResTy, MIB, SPIRV::AccessQualifier::ReadWrite, EmitIR);
return GR.getOrCreateSPIRVPointerType(NewBaseType, MIB, SC);
}
// 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();
Register OpTypeReg = getTypeReg(MRI, 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
SPIRVType *NewPtrType =
createNewPtrType(GR, I, OpType, IsSameMF, false, ResType, ResTy);
if (!GR.isBitcastCompatible(NewPtrType, OpType))
report_fatal_error(
"insert validation bitcast: incompatible result and operand types");
doInsertBitcast(STI, MRI, GR, I, OpReg, OpIdx, NewPtrType);
}
// Insert a bitcast before OpGroupWaitEvents if the last argument is a pointer
// that doesn't point to OpTypeEvent.
static void validateGroupWaitEventsPtr(const SPIRVSubtarget &STI,
MachineRegisterInfo *MRI,
SPIRVGlobalRegistry &GR,
MachineInstr &I) {
constexpr unsigned OpIdx = 2;
MachineFunction *MF = I.getParent()->getParent();
Register OpReg = I.getOperand(OpIdx).getReg();
Register OpTypeReg = getTypeReg(MRI, OpReg);
SPIRVType *OpType = GR.getSPIRVTypeForVReg(OpTypeReg, MF);
if (!OpType || OpType->getOpcode() != SPIRV::OpTypePointer)
return;
SPIRVType *ElemType = GR.getSPIRVTypeForVReg(OpType->getOperand(2).getReg());
if (!ElemType || ElemType->getOpcode() == SPIRV::OpTypeEvent)
return;
// Insert a bitcast before the instruction to keep SPIR-V code valid.
LLVMContext &Context = MF->getFunction().getContext();
SPIRVType *NewPtrType =
createNewPtrType(GR, I, OpType, false, true, nullptr,
TargetExtType::get(Context, "spirv.Event"));
doInsertBitcast(STI, MRI, GR, I, OpReg, OpIdx, NewPtrType);
}
static void validateLifetimeStart(const SPIRVSubtarget &STI,
MachineRegisterInfo *MRI,
SPIRVGlobalRegistry &GR, MachineInstr &I) {
Register PtrReg = I.getOperand(0).getReg();
MachineFunction *MF = I.getParent()->getParent();
Register PtrTypeReg = getTypeReg(MRI, PtrReg);
SPIRVType *PtrType = GR.getSPIRVTypeForVReg(PtrTypeReg, MF);
SPIRVType *PonteeElemType = PtrType ? GR.getPointeeType(PtrType) : nullptr;
if (!PonteeElemType || PonteeElemType->getOpcode() == SPIRV::OpTypeVoid ||
(PonteeElemType->getOpcode() == SPIRV::OpTypeInt &&
PonteeElemType->getOperand(1).getImm() == 8))
return;
// To keep the code valid a bitcast must be inserted
SPIRV::StorageClass::StorageClass SC =
static_cast<SPIRV::StorageClass::StorageClass>(
PtrType->getOperand(1).getImm());
MachineIRBuilder MIB(I);
LLVMContext &Context = MF->getFunction().getContext();
SPIRVType *ElemType =
GR.getOrCreateSPIRVType(IntegerType::getInt8Ty(Context), MIB);
SPIRVType *NewPtrType = GR.getOrCreateSPIRVPointerType(ElemType, MIB, SC);
doInsertBitcast(STI, MRI, GR, I, PtrReg, 0, NewPtrType);
}
static void validateGroupAsyncCopyPtr(const SPIRVSubtarget &STI,
MachineRegisterInfo *MRI,
SPIRVGlobalRegistry &GR, MachineInstr &I,
unsigned OpIdx) {
MachineFunction *MF = I.getParent()->getParent();
Register OpReg = I.getOperand(OpIdx).getReg();
Register OpTypeReg = getTypeReg(MRI, OpReg);
SPIRVType *OpType = GR.getSPIRVTypeForVReg(OpTypeReg, MF);
if (!OpType || OpType->getOpcode() != SPIRV::OpTypePointer)
return;
SPIRVType *ElemType = GR.getSPIRVTypeForVReg(OpType->getOperand(2).getReg());
if (!ElemType || ElemType->getOpcode() != SPIRV::OpTypeStruct ||
ElemType->getNumOperands() != 2)
return;
// It's a structure-wrapper around another type with a single member field.
SPIRVType *MemberType =
GR.getSPIRVTypeForVReg(ElemType->getOperand(1).getReg());
if (!MemberType)
return;
unsigned MemberTypeOp = MemberType->getOpcode();
if (MemberTypeOp != SPIRV::OpTypeVector && MemberTypeOp != SPIRV::OpTypeInt &&
MemberTypeOp != SPIRV::OpTypeFloat && MemberTypeOp != SPIRV::OpTypeBool)
return;
// It's a structure-wrapper around a valid type. 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 *NewPtrType = GR.getOrCreateSPIRVPointerType(MemberType, MIB, SC);
doInsertBitcast(STI, MRI, GR, I, OpReg, OpIdx, NewPtrType);
}
// 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;
SmallPtrSet<MachineInstr *, 8> ToMove;
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:
case SPIRV::OpGenericCastToPtr:
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::OpLifetimeStart:
case SPIRV::OpLifetimeStop:
if (MI.getOperand(1).getImm() > 0)
validateLifetimeStart(STI, MRI, GR, MI);
break;
case SPIRV::OpGroupAsyncCopy:
validateGroupAsyncCopyPtr(STI, MRI, GR, MI, 3);
validateGroupAsyncCopyPtr(STI, MRI, GR, MI, 4);
break;
case SPIRV::OpGroupWaitEvents:
// OpGroupWaitEvents ..., ..., <pointer to OpTypeEvent>
validateGroupWaitEventsPtr(STI, MRI, GR, MI);
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;
case SPIRV::OpPhi: {
// Phi refers to a type definition that goes after the Phi
// instruction, so that the virtual register definition of the type
// doesn't dominate all uses. Let's place the type definition
// instruction at the end of the predecessor.
MachineBasicBlock *Curr = MI.getParent();
SPIRVType *Type = GR.getSPIRVTypeForVReg(MI.getOperand(1).getReg());
if (Type->getParent() == Curr && !Curr->pred_empty())
ToMove.insert(const_cast<MachineInstr *>(Type));
} break;
}
}
for (MachineInstr *MI : ToMove) {
MachineBasicBlock *Curr = MI->getParent();
MachineBasicBlock *Pred = *Curr->pred_begin();
Pred->insert(Pred->getFirstTerminator(), Curr->remove_instr(MI));
}
}
ProcessedMF.insert(&MF);
TargetLowering::finalizeLowering(MF);
}