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llvm-project/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp

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//===-- llvm/CodeGen/GlobalISel/IRTranslator.cpp - IRTranslator --*- C++ -*-==//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
/// \file
/// This file implements the IRTranslator class.
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/GlobalISel/IRTranslator.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/CodeGen/GlobalISel/CallLowering.h"
#include "llvm/CodeGen/Analysis.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/TargetPassConfig.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/Value.h"
#include "llvm/Target/TargetFrameLowering.h"
#include "llvm/Target/TargetIntrinsicInfo.h"
#include "llvm/Target/TargetLowering.h"
#define DEBUG_TYPE "irtranslator"
using namespace llvm;
char IRTranslator::ID = 0;
INITIALIZE_PASS_BEGIN(IRTranslator, DEBUG_TYPE, "IRTranslator LLVM IR -> MI",
false, false)
INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
INITIALIZE_PASS_END(IRTranslator, DEBUG_TYPE, "IRTranslator LLVM IR -> MI",
false, false)
static void reportTranslationError(const Value &V, const Twine &Message) {
std::string ErrStorage;
raw_string_ostream Err(ErrStorage);
Err << Message << ": " << V << '\n';
report_fatal_error(Err.str());
}
IRTranslator::IRTranslator() : MachineFunctionPass(ID), MRI(nullptr) {
initializeIRTranslatorPass(*PassRegistry::getPassRegistry());
}
void IRTranslator::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<TargetPassConfig>();
MachineFunctionPass::getAnalysisUsage(AU);
}
unsigned IRTranslator::getOrCreateVReg(const Value &Val) {
unsigned &ValReg = ValToVReg[&Val];
if (ValReg)
return ValReg;
// Fill ValRegsSequence with the sequence of registers
// we need to concat together to produce the value.
assert(Val.getType()->isSized() &&
"Don't know how to create an empty vreg");
unsigned VReg = MRI->createGenericVirtualRegister(LLT{*Val.getType(), *DL});
ValReg = VReg;
if (auto CV = dyn_cast<Constant>(&Val)) {
bool Success = translate(*CV, VReg);
if (!Success) {
if (!TPC->isGlobalISelAbortEnabled()) {
MF->getProperties().set(
MachineFunctionProperties::Property::FailedISel);
return VReg;
}
reportTranslationError(Val, "unable to translate constant");
}
}
return VReg;
}
int IRTranslator::getOrCreateFrameIndex(const AllocaInst &AI) {
if (FrameIndices.find(&AI) != FrameIndices.end())
return FrameIndices[&AI];
unsigned ElementSize = DL->getTypeStoreSize(AI.getAllocatedType());
unsigned Size =
ElementSize * cast<ConstantInt>(AI.getArraySize())->getZExtValue();
// Always allocate at least one byte.
Size = std::max(Size, 1u);
unsigned Alignment = AI.getAlignment();
if (!Alignment)
Alignment = DL->getABITypeAlignment(AI.getAllocatedType());
int &FI = FrameIndices[&AI];
FI = MF->getFrameInfo().CreateStackObject(Size, Alignment, false, &AI);
return FI;
}
unsigned IRTranslator::getMemOpAlignment(const Instruction &I) {
unsigned Alignment = 0;
Type *ValTy = nullptr;
if (const StoreInst *SI = dyn_cast<StoreInst>(&I)) {
Alignment = SI->getAlignment();
ValTy = SI->getValueOperand()->getType();
} else if (const LoadInst *LI = dyn_cast<LoadInst>(&I)) {
Alignment = LI->getAlignment();
ValTy = LI->getType();
} else if (!TPC->isGlobalISelAbortEnabled()) {
MF->getProperties().set(
MachineFunctionProperties::Property::FailedISel);
return 1;
} else
llvm_unreachable("unhandled memory instruction");
return Alignment ? Alignment : DL->getABITypeAlignment(ValTy);
}
MachineBasicBlock &IRTranslator::getOrCreateBB(const BasicBlock &BB) {
MachineBasicBlock *&MBB = BBToMBB[&BB];
if (!MBB) {
MBB = MF->CreateMachineBasicBlock(&BB);
MF->push_back(MBB);
if (BB.hasAddressTaken())
MBB->setHasAddressTaken();
}
return *MBB;
}
void IRTranslator::addMachineCFGPred(CFGEdge Edge, MachineBasicBlock *NewPred) {
assert(NewPred && "new predecessor must be a real MachineBasicBlock");
MachinePreds[Edge].push_back(NewPred);
}
bool IRTranslator::translateBinaryOp(unsigned Opcode, const User &U,
MachineIRBuilder &MIRBuilder) {
// FIXME: handle signed/unsigned wrapping flags.
// Get or create a virtual register for each value.
// Unless the value is a Constant => loadimm cst?
// or inline constant each time?
// Creation of a virtual register needs to have a size.
unsigned Op0 = getOrCreateVReg(*U.getOperand(0));
unsigned Op1 = getOrCreateVReg(*U.getOperand(1));
unsigned Res = getOrCreateVReg(U);
MIRBuilder.buildInstr(Opcode).addDef(Res).addUse(Op0).addUse(Op1);
return true;
}
bool IRTranslator::translateCompare(const User &U,
MachineIRBuilder &MIRBuilder) {
const CmpInst *CI = dyn_cast<CmpInst>(&U);
unsigned Op0 = getOrCreateVReg(*U.getOperand(0));
unsigned Op1 = getOrCreateVReg(*U.getOperand(1));
unsigned Res = getOrCreateVReg(U);
CmpInst::Predicate Pred =
CI ? CI->getPredicate() : static_cast<CmpInst::Predicate>(
cast<ConstantExpr>(U).getPredicate());
if (CmpInst::isIntPredicate(Pred))
MIRBuilder.buildICmp(Pred, Res, Op0, Op1);
else
MIRBuilder.buildFCmp(Pred, Res, Op0, Op1);
return true;
}
bool IRTranslator::translateRet(const User &U, MachineIRBuilder &MIRBuilder) {
const ReturnInst &RI = cast<ReturnInst>(U);
const Value *Ret = RI.getReturnValue();
// The target may mess up with the insertion point, but
// this is not important as a return is the last instruction
// of the block anyway.
return CLI->lowerReturn(MIRBuilder, Ret, !Ret ? 0 : getOrCreateVReg(*Ret));
}
bool IRTranslator::translateBr(const User &U, MachineIRBuilder &MIRBuilder) {
const BranchInst &BrInst = cast<BranchInst>(U);
unsigned Succ = 0;
if (!BrInst.isUnconditional()) {
// We want a G_BRCOND to the true BB followed by an unconditional branch.
unsigned Tst = getOrCreateVReg(*BrInst.getCondition());
const BasicBlock &TrueTgt = *cast<BasicBlock>(BrInst.getSuccessor(Succ++));
MachineBasicBlock &TrueBB = getOrCreateBB(TrueTgt);
MIRBuilder.buildBrCond(Tst, TrueBB);
}
const BasicBlock &BrTgt = *cast<BasicBlock>(BrInst.getSuccessor(Succ));
MachineBasicBlock &TgtBB = getOrCreateBB(BrTgt);
MIRBuilder.buildBr(TgtBB);
// Link successors.
MachineBasicBlock &CurBB = MIRBuilder.getMBB();
for (const BasicBlock *Succ : BrInst.successors())
CurBB.addSuccessor(&getOrCreateBB(*Succ));
return true;
}
bool IRTranslator::translateSwitch(const User &U,
MachineIRBuilder &MIRBuilder) {
// For now, just translate as a chain of conditional branches.
// FIXME: could we share most of the logic/code in
// SelectionDAGBuilder::visitSwitch between SelectionDAG and GlobalISel?
// At first sight, it seems most of the logic in there is independent of
// SelectionDAG-specifics and a lot of work went in to optimize switch
// lowering in there.
const SwitchInst &SwInst = cast<SwitchInst>(U);
const unsigned SwCondValue = getOrCreateVReg(*SwInst.getCondition());
const BasicBlock *OrigBB = SwInst.getParent();
LLT LLTi1 = LLT(*Type::getInt1Ty(U.getContext()), *DL);
for (auto &CaseIt : SwInst.cases()) {
const unsigned CaseValueReg = getOrCreateVReg(*CaseIt.getCaseValue());
const unsigned Tst = MRI->createGenericVirtualRegister(LLTi1);
MIRBuilder.buildICmp(CmpInst::ICMP_EQ, Tst, CaseValueReg, SwCondValue);
MachineBasicBlock &CurMBB = MIRBuilder.getMBB();
const BasicBlock *TrueBB = CaseIt.getCaseSuccessor();
MachineBasicBlock &TrueMBB = getOrCreateBB(*TrueBB);
MIRBuilder.buildBrCond(Tst, TrueMBB);
CurMBB.addSuccessor(&TrueMBB);
addMachineCFGPred({OrigBB, TrueBB}, &CurMBB);
MachineBasicBlock *FalseMBB =
MF->CreateMachineBasicBlock(SwInst.getParent());
MF->push_back(FalseMBB);
MIRBuilder.buildBr(*FalseMBB);
CurMBB.addSuccessor(FalseMBB);
MIRBuilder.setMBB(*FalseMBB);
}
// handle default case
const BasicBlock *DefaultBB = SwInst.getDefaultDest();
MachineBasicBlock &DefaultMBB = getOrCreateBB(*DefaultBB);
MIRBuilder.buildBr(DefaultMBB);
MachineBasicBlock &CurMBB = MIRBuilder.getMBB();
CurMBB.addSuccessor(&DefaultMBB);
addMachineCFGPred({OrigBB, DefaultBB}, &CurMBB);
return true;
}
bool IRTranslator::translateIndirectBr(const User &U,
MachineIRBuilder &MIRBuilder) {
const IndirectBrInst &BrInst = cast<IndirectBrInst>(U);
const unsigned Tgt = getOrCreateVReg(*BrInst.getAddress());
MIRBuilder.buildBrIndirect(Tgt);
// Link successors.
MachineBasicBlock &CurBB = MIRBuilder.getMBB();
for (const BasicBlock *Succ : BrInst.successors())
CurBB.addSuccessor(&getOrCreateBB(*Succ));
return true;
}
bool IRTranslator::translateLoad(const User &U, MachineIRBuilder &MIRBuilder) {
const LoadInst &LI = cast<LoadInst>(U);
if (!TPC->isGlobalISelAbortEnabled() && LI.isAtomic())
return false;
assert(!LI.isAtomic() && "only non-atomic loads are supported at the moment");
auto Flags = LI.isVolatile() ? MachineMemOperand::MOVolatile
: MachineMemOperand::MONone;
Flags |= MachineMemOperand::MOLoad;
unsigned Res = getOrCreateVReg(LI);
unsigned Addr = getOrCreateVReg(*LI.getPointerOperand());
LLT VTy{*LI.getType(), *DL}, PTy{*LI.getPointerOperand()->getType(), *DL};
MIRBuilder.buildLoad(
Res, Addr,
*MF->getMachineMemOperand(MachinePointerInfo(LI.getPointerOperand()),
Flags, DL->getTypeStoreSize(LI.getType()),
getMemOpAlignment(LI)));
return true;
}
bool IRTranslator::translateStore(const User &U, MachineIRBuilder &MIRBuilder) {
const StoreInst &SI = cast<StoreInst>(U);
if (!TPC->isGlobalISelAbortEnabled() && SI.isAtomic())
return false;
assert(!SI.isAtomic() && "only non-atomic stores supported at the moment");
auto Flags = SI.isVolatile() ? MachineMemOperand::MOVolatile
: MachineMemOperand::MONone;
Flags |= MachineMemOperand::MOStore;
unsigned Val = getOrCreateVReg(*SI.getValueOperand());
unsigned Addr = getOrCreateVReg(*SI.getPointerOperand());
LLT VTy{*SI.getValueOperand()->getType(), *DL},
PTy{*SI.getPointerOperand()->getType(), *DL};
MIRBuilder.buildStore(
Val, Addr,
*MF->getMachineMemOperand(
MachinePointerInfo(SI.getPointerOperand()), Flags,
DL->getTypeStoreSize(SI.getValueOperand()->getType()),
getMemOpAlignment(SI)));
return true;
}
bool IRTranslator::translateExtractValue(const User &U,
MachineIRBuilder &MIRBuilder) {
const Value *Src = U.getOperand(0);
Type *Int32Ty = Type::getInt32Ty(U.getContext());
SmallVector<Value *, 1> Indices;
// getIndexedOffsetInType is designed for GEPs, so the first index is the
// usual array element rather than looking into the actual aggregate.
Indices.push_back(ConstantInt::get(Int32Ty, 0));
if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(&U)) {
for (auto Idx : EVI->indices())
Indices.push_back(ConstantInt::get(Int32Ty, Idx));
} else {
for (unsigned i = 1; i < U.getNumOperands(); ++i)
Indices.push_back(U.getOperand(i));
}
uint64_t Offset = 8 * DL->getIndexedOffsetInType(Src->getType(), Indices);
unsigned Res = getOrCreateVReg(U);
MIRBuilder.buildExtract(Res, Offset, getOrCreateVReg(*Src));
return true;
}
bool IRTranslator::translateInsertValue(const User &U,
MachineIRBuilder &MIRBuilder) {
const Value *Src = U.getOperand(0);
Type *Int32Ty = Type::getInt32Ty(U.getContext());
SmallVector<Value *, 1> Indices;
// getIndexedOffsetInType is designed for GEPs, so the first index is the
// usual array element rather than looking into the actual aggregate.
Indices.push_back(ConstantInt::get(Int32Ty, 0));
if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(&U)) {
for (auto Idx : IVI->indices())
Indices.push_back(ConstantInt::get(Int32Ty, Idx));
} else {
for (unsigned i = 2; i < U.getNumOperands(); ++i)
Indices.push_back(U.getOperand(i));
}
uint64_t Offset = 8 * DL->getIndexedOffsetInType(Src->getType(), Indices);
unsigned Res = getOrCreateVReg(U);
const Value &Inserted = *U.getOperand(1);
MIRBuilder.buildInsert(Res, getOrCreateVReg(*Src), getOrCreateVReg(Inserted),
Offset);
return true;
}
bool IRTranslator::translateSelect(const User &U,
MachineIRBuilder &MIRBuilder) {
MIRBuilder.buildSelect(getOrCreateVReg(U), getOrCreateVReg(*U.getOperand(0)),
getOrCreateVReg(*U.getOperand(1)),
getOrCreateVReg(*U.getOperand(2)));
return true;
}
bool IRTranslator::translateBitCast(const User &U,
MachineIRBuilder &MIRBuilder) {
if (LLT{*U.getOperand(0)->getType(), *DL} == LLT{*U.getType(), *DL}) {
unsigned &Reg = ValToVReg[&U];
if (Reg)
MIRBuilder.buildCopy(Reg, getOrCreateVReg(*U.getOperand(0)));
else
Reg = getOrCreateVReg(*U.getOperand(0));
return true;
}
return translateCast(TargetOpcode::G_BITCAST, U, MIRBuilder);
}
bool IRTranslator::translateCast(unsigned Opcode, const User &U,
MachineIRBuilder &MIRBuilder) {
unsigned Op = getOrCreateVReg(*U.getOperand(0));
unsigned Res = getOrCreateVReg(U);
MIRBuilder.buildInstr(Opcode).addDef(Res).addUse(Op);
return true;
}
bool IRTranslator::translateGetElementPtr(const User &U,
MachineIRBuilder &MIRBuilder) {
// FIXME: support vector GEPs.
if (U.getType()->isVectorTy())
return false;
Value &Op0 = *U.getOperand(0);
unsigned BaseReg = getOrCreateVReg(Op0);
LLT PtrTy{*Op0.getType(), *DL};
unsigned PtrSize = DL->getPointerSizeInBits(PtrTy.getAddressSpace());
LLT OffsetTy = LLT::scalar(PtrSize);
int64_t Offset = 0;
for (gep_type_iterator GTI = gep_type_begin(&U), E = gep_type_end(&U);
GTI != E; ++GTI) {
const Value *Idx = GTI.getOperand();
if (StructType *StTy = GTI.getStructTypeOrNull()) {
unsigned Field = cast<Constant>(Idx)->getUniqueInteger().getZExtValue();
Offset += DL->getStructLayout(StTy)->getElementOffset(Field);
continue;
} else {
uint64_t ElementSize = DL->getTypeAllocSize(GTI.getIndexedType());
// If this is a scalar constant or a splat vector of constants,
// handle it quickly.
if (const auto *CI = dyn_cast<ConstantInt>(Idx)) {
Offset += ElementSize * CI->getSExtValue();
continue;
}
if (Offset != 0) {
unsigned NewBaseReg = MRI->createGenericVirtualRegister(PtrTy);
unsigned OffsetReg = MRI->createGenericVirtualRegister(OffsetTy);
MIRBuilder.buildConstant(OffsetReg, Offset);
MIRBuilder.buildGEP(NewBaseReg, BaseReg, OffsetReg);
BaseReg = NewBaseReg;
Offset = 0;
}
// N = N + Idx * ElementSize;
unsigned ElementSizeReg = MRI->createGenericVirtualRegister(OffsetTy);
MIRBuilder.buildConstant(ElementSizeReg, ElementSize);
unsigned IdxReg = getOrCreateVReg(*Idx);
if (MRI->getType(IdxReg) != OffsetTy) {
unsigned NewIdxReg = MRI->createGenericVirtualRegister(OffsetTy);
MIRBuilder.buildSExtOrTrunc(NewIdxReg, IdxReg);
IdxReg = NewIdxReg;
}
unsigned OffsetReg = MRI->createGenericVirtualRegister(OffsetTy);
MIRBuilder.buildMul(OffsetReg, ElementSizeReg, IdxReg);
unsigned NewBaseReg = MRI->createGenericVirtualRegister(PtrTy);
MIRBuilder.buildGEP(NewBaseReg, BaseReg, OffsetReg);
BaseReg = NewBaseReg;
}
}
if (Offset != 0) {
unsigned OffsetReg = MRI->createGenericVirtualRegister(OffsetTy);
MIRBuilder.buildConstant(OffsetReg, Offset);
MIRBuilder.buildGEP(getOrCreateVReg(U), BaseReg, OffsetReg);
return true;
}
MIRBuilder.buildCopy(getOrCreateVReg(U), BaseReg);
return true;
}
bool IRTranslator::translateMemfunc(const CallInst &CI,
MachineIRBuilder &MIRBuilder,
unsigned ID) {
LLT SizeTy{*CI.getArgOperand(2)->getType(), *DL};
Type *DstTy = CI.getArgOperand(0)->getType();
if (cast<PointerType>(DstTy)->getAddressSpace() != 0 ||
SizeTy.getSizeInBits() != DL->getPointerSizeInBits(0))
return false;
SmallVector<CallLowering::ArgInfo, 8> Args;
for (int i = 0; i < 3; ++i) {
const auto &Arg = CI.getArgOperand(i);
Args.emplace_back(getOrCreateVReg(*Arg), Arg->getType());
}
const char *Callee;
switch (ID) {
case Intrinsic::memmove:
case Intrinsic::memcpy: {
Type *SrcTy = CI.getArgOperand(1)->getType();
if(cast<PointerType>(SrcTy)->getAddressSpace() != 0)
return false;
Callee = ID == Intrinsic::memcpy ? "memcpy" : "memmove";
break;
}
case Intrinsic::memset:
Callee = "memset";
break;
default:
return false;
}
return CLI->lowerCall(MIRBuilder, MachineOperand::CreateES(Callee),
CallLowering::ArgInfo(0, CI.getType()), Args);
}
void IRTranslator::getStackGuard(unsigned DstReg,
MachineIRBuilder &MIRBuilder) {
const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
MRI->setRegClass(DstReg, TRI->getPointerRegClass(*MF));
auto MIB = MIRBuilder.buildInstr(TargetOpcode::LOAD_STACK_GUARD);
MIB.addDef(DstReg);
auto &TLI = *MF->getSubtarget().getTargetLowering();
Value *Global = TLI.getSDagStackGuard(*MF->getFunction()->getParent());
if (!Global)
return;
MachinePointerInfo MPInfo(Global);
MachineInstr::mmo_iterator MemRefs = MF->allocateMemRefsArray(1);
auto Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOInvariant |
MachineMemOperand::MODereferenceable;
*MemRefs =
MF->getMachineMemOperand(MPInfo, Flags, DL->getPointerSizeInBits() / 8,
DL->getPointerABIAlignment());
MIB.setMemRefs(MemRefs, MemRefs + 1);
}
bool IRTranslator::translateOverflowIntrinsic(const CallInst &CI, unsigned Op,
MachineIRBuilder &MIRBuilder) {
LLT Ty{*CI.getOperand(0)->getType(), *DL};
LLT s1 = LLT::scalar(1);
unsigned Width = Ty.getSizeInBits();
unsigned Res = MRI->createGenericVirtualRegister(Ty);
unsigned Overflow = MRI->createGenericVirtualRegister(s1);
auto MIB = MIRBuilder.buildInstr(Op)
.addDef(Res)
.addDef(Overflow)
.addUse(getOrCreateVReg(*CI.getOperand(0)))
.addUse(getOrCreateVReg(*CI.getOperand(1)));
if (Op == TargetOpcode::G_UADDE || Op == TargetOpcode::G_USUBE) {
unsigned Zero = MRI->createGenericVirtualRegister(s1);
EntryBuilder.buildConstant(Zero, 0);
MIB.addUse(Zero);
}
MIRBuilder.buildSequence(getOrCreateVReg(CI), Res, 0, Overflow, Width);
return true;
}
bool IRTranslator::translateKnownIntrinsic(const CallInst &CI, Intrinsic::ID ID,
MachineIRBuilder &MIRBuilder) {
switch (ID) {
default:
break;
case Intrinsic::dbg_declare: {
const DbgDeclareInst &DI = cast<DbgDeclareInst>(CI);
assert(DI.getVariable() && "Missing variable");
const Value *Address = DI.getAddress();
if (!Address || isa<UndefValue>(Address)) {
DEBUG(dbgs() << "Dropping debug info for " << DI << "\n");
return true;
}
unsigned Reg = getOrCreateVReg(*Address);
auto RegDef = MRI->def_instr_begin(Reg);
assert(DI.getVariable()->isValidLocationForIntrinsic(
MIRBuilder.getDebugLoc()) &&
"Expected inlined-at fields to agree");
if (RegDef != MRI->def_instr_end() &&
RegDef->getOpcode() == TargetOpcode::G_FRAME_INDEX) {
MIRBuilder.buildFIDbgValue(RegDef->getOperand(1).getIndex(),
DI.getVariable(), DI.getExpression());
} else
MIRBuilder.buildDirectDbgValue(Reg, DI.getVariable(), DI.getExpression());
return true;
}
case Intrinsic::vaend:
// No target I know of cares about va_end. Certainly no in-tree target
// does. Simplest intrinsic ever!
return true;
case Intrinsic::dbg_value: {
// This form of DBG_VALUE is target-independent.
const DbgValueInst &DI = cast<DbgValueInst>(CI);
const Value *V = DI.getValue();
assert(DI.getVariable()->isValidLocationForIntrinsic(
MIRBuilder.getDebugLoc()) &&
"Expected inlined-at fields to agree");
if (!V) {
// Currently the optimizer can produce this; insert an undef to
// help debugging. Probably the optimizer should not do this.
MIRBuilder.buildIndirectDbgValue(0, DI.getOffset(), DI.getVariable(),
DI.getExpression());
} else if (const auto *CI = dyn_cast<Constant>(V)) {
MIRBuilder.buildConstDbgValue(*CI, DI.getOffset(), DI.getVariable(),
DI.getExpression());
} else {
unsigned Reg = getOrCreateVReg(*V);
// FIXME: This does not handle register-indirect values at offset 0. The
// direct/indirect thing shouldn't really be handled by something as
// implicit as reg+noreg vs reg+imm in the first palce, but it seems
// pretty baked in right now.
if (DI.getOffset() != 0)
MIRBuilder.buildIndirectDbgValue(Reg, DI.getOffset(), DI.getVariable(),
DI.getExpression());
else
MIRBuilder.buildDirectDbgValue(Reg, DI.getVariable(),
DI.getExpression());
}
return true;
}
case Intrinsic::uadd_with_overflow:
return translateOverflowIntrinsic(CI, TargetOpcode::G_UADDE, MIRBuilder);
case Intrinsic::sadd_with_overflow:
return translateOverflowIntrinsic(CI, TargetOpcode::G_SADDO, MIRBuilder);
case Intrinsic::usub_with_overflow:
return translateOverflowIntrinsic(CI, TargetOpcode::G_USUBE, MIRBuilder);
case Intrinsic::ssub_with_overflow:
return translateOverflowIntrinsic(CI, TargetOpcode::G_SSUBO, MIRBuilder);
case Intrinsic::umul_with_overflow:
return translateOverflowIntrinsic(CI, TargetOpcode::G_UMULO, MIRBuilder);
case Intrinsic::smul_with_overflow:
return translateOverflowIntrinsic(CI, TargetOpcode::G_SMULO, MIRBuilder);
case Intrinsic::memcpy:
case Intrinsic::memmove:
case Intrinsic::memset:
return translateMemfunc(CI, MIRBuilder, ID);
case Intrinsic::eh_typeid_for: {
GlobalValue *GV = ExtractTypeInfo(CI.getArgOperand(0));
unsigned Reg = getOrCreateVReg(CI);
unsigned TypeID = MF->getTypeIDFor(GV);
MIRBuilder.buildConstant(Reg, TypeID);
return true;
}
case Intrinsic::objectsize: {
// If we don't know by now, we're never going to know.
const ConstantInt *Min = cast<ConstantInt>(CI.getArgOperand(1));
MIRBuilder.buildConstant(getOrCreateVReg(CI), Min->isZero() ? -1ULL : 0);
return true;
}
case Intrinsic::stackguard:
getStackGuard(getOrCreateVReg(CI), MIRBuilder);
return true;
case Intrinsic::stackprotector: {
LLT PtrTy{*CI.getArgOperand(0)->getType(), *DL};
unsigned GuardVal = MRI->createGenericVirtualRegister(PtrTy);
getStackGuard(GuardVal, MIRBuilder);
AllocaInst *Slot = cast<AllocaInst>(CI.getArgOperand(1));
MIRBuilder.buildStore(
GuardVal, getOrCreateVReg(*Slot),
*MF->getMachineMemOperand(
MachinePointerInfo::getFixedStack(*MF,
getOrCreateFrameIndex(*Slot)),
MachineMemOperand::MOStore | MachineMemOperand::MOVolatile,
PtrTy.getSizeInBits() / 8, 8));
return true;
}
}
return false;
}
bool IRTranslator::translateCall(const User &U, MachineIRBuilder &MIRBuilder) {
const CallInst &CI = cast<CallInst>(U);
auto TII = MF->getTarget().getIntrinsicInfo();
const Function *F = CI.getCalledFunction();
if (CI.isInlineAsm())
return false;
if (!F || !F->isIntrinsic()) {
unsigned Res = CI.getType()->isVoidTy() ? 0 : getOrCreateVReg(CI);
SmallVector<unsigned, 8> Args;
for (auto &Arg: CI.arg_operands())
Args.push_back(getOrCreateVReg(*Arg));
return CLI->lowerCall(MIRBuilder, CI, Res, Args, [&]() {
return getOrCreateVReg(*CI.getCalledValue());
});
}
Intrinsic::ID ID = F->getIntrinsicID();
if (TII && ID == Intrinsic::not_intrinsic)
ID = static_cast<Intrinsic::ID>(TII->getIntrinsicID(F));
assert(ID != Intrinsic::not_intrinsic && "unknown intrinsic");
if (translateKnownIntrinsic(CI, ID, MIRBuilder))
return true;
unsigned Res = CI.getType()->isVoidTy() ? 0 : getOrCreateVReg(CI);
MachineInstrBuilder MIB =
MIRBuilder.buildIntrinsic(ID, Res, !CI.doesNotAccessMemory());
for (auto &Arg : CI.arg_operands()) {
if (ConstantInt *CI = dyn_cast<ConstantInt>(Arg))
MIB.addImm(CI->getSExtValue());
else
MIB.addUse(getOrCreateVReg(*Arg));
}
return true;
}
bool IRTranslator::translateInvoke(const User &U,
MachineIRBuilder &MIRBuilder) {
const InvokeInst &I = cast<InvokeInst>(U);
MCContext &Context = MF->getContext();
const BasicBlock *ReturnBB = I.getSuccessor(0);
const BasicBlock *EHPadBB = I.getSuccessor(1);
const Value *Callee(I.getCalledValue());
const Function *Fn = dyn_cast<Function>(Callee);
if (isa<InlineAsm>(Callee))
return false;
// FIXME: support invoking patchpoint and statepoint intrinsics.
if (Fn && Fn->isIntrinsic())
return false;
// FIXME: support whatever these are.
if (I.countOperandBundlesOfType(LLVMContext::OB_deopt))
return false;
// FIXME: support Windows exception handling.
if (!isa<LandingPadInst>(EHPadBB->front()))
return false;
// Emit the actual call, bracketed by EH_LABELs so that the MF knows about
// the region covered by the try.
MCSymbol *BeginSymbol = Context.createTempSymbol();
MIRBuilder.buildInstr(TargetOpcode::EH_LABEL).addSym(BeginSymbol);
unsigned Res = I.getType()->isVoidTy() ? 0 : getOrCreateVReg(I);
SmallVector<unsigned, 8> Args;
for (auto &Arg: I.arg_operands())
Args.push_back(getOrCreateVReg(*Arg));
CLI->lowerCall(MIRBuilder, I, Res, Args,
[&]() { return getOrCreateVReg(*I.getCalledValue()); });
MCSymbol *EndSymbol = Context.createTempSymbol();
MIRBuilder.buildInstr(TargetOpcode::EH_LABEL).addSym(EndSymbol);
// FIXME: track probabilities.
MachineBasicBlock &EHPadMBB = getOrCreateBB(*EHPadBB),
&ReturnMBB = getOrCreateBB(*ReturnBB);
MF->addInvoke(&EHPadMBB, BeginSymbol, EndSymbol);
MIRBuilder.getMBB().addSuccessor(&ReturnMBB);
MIRBuilder.getMBB().addSuccessor(&EHPadMBB);
MIRBuilder.buildBr(ReturnMBB);
return true;
}
bool IRTranslator::translateLandingPad(const User &U,
MachineIRBuilder &MIRBuilder) {
const LandingPadInst &LP = cast<LandingPadInst>(U);
MachineBasicBlock &MBB = MIRBuilder.getMBB();
addLandingPadInfo(LP, MBB);
MBB.setIsEHPad();
// If there aren't registers to copy the values into (e.g., during SjLj
// exceptions), then don't bother.
auto &TLI = *MF->getSubtarget().getTargetLowering();
const Constant *PersonalityFn = MF->getFunction()->getPersonalityFn();
if (TLI.getExceptionPointerRegister(PersonalityFn) == 0 &&
TLI.getExceptionSelectorRegister(PersonalityFn) == 0)
return true;
// If landingpad's return type is token type, we don't create DAG nodes
// for its exception pointer and selector value. The extraction of exception
// pointer or selector value from token type landingpads is not currently
// supported.
if (LP.getType()->isTokenTy())
return true;
// Add a label to mark the beginning of the landing pad. Deletion of the
// landing pad can thus be detected via the MachineModuleInfo.
MIRBuilder.buildInstr(TargetOpcode::EH_LABEL)
.addSym(MF->addLandingPad(&MBB));
SmallVector<LLT, 2> Tys;
for (Type *Ty : cast<StructType>(LP.getType())->elements())
Tys.push_back(LLT{*Ty, *DL});
assert(Tys.size() == 2 && "Only two-valued landingpads are supported");
// Mark exception register as live in.
SmallVector<unsigned, 2> Regs;
SmallVector<uint64_t, 2> Offsets;
if (unsigned Reg = TLI.getExceptionPointerRegister(PersonalityFn)) {
MBB.addLiveIn(Reg);
unsigned VReg = MRI->createGenericVirtualRegister(Tys[0]);
MIRBuilder.buildCopy(VReg, Reg);
Regs.push_back(VReg);
Offsets.push_back(0);
}
if (unsigned Reg = TLI.getExceptionSelectorRegister(PersonalityFn)) {
MBB.addLiveIn(Reg);
// N.b. the exception selector register always has pointer type and may not
// match the actual IR-level type in the landingpad so an extra cast is
// needed.
unsigned PtrVReg = MRI->createGenericVirtualRegister(Tys[0]);
MIRBuilder.buildCopy(PtrVReg, Reg);
unsigned VReg = MRI->createGenericVirtualRegister(Tys[1]);
MIRBuilder.buildInstr(TargetOpcode::G_PTRTOINT)
.addDef(VReg)
.addUse(PtrVReg);
Regs.push_back(VReg);
Offsets.push_back(Tys[0].getSizeInBits());
}
MIRBuilder.buildSequence(getOrCreateVReg(LP), Regs, Offsets);
return true;
}
bool IRTranslator::translateAlloca(const User &U,
MachineIRBuilder &MIRBuilder) {
auto &AI = cast<AllocaInst>(U);
if (AI.isStaticAlloca()) {
unsigned Res = getOrCreateVReg(AI);
int FI = getOrCreateFrameIndex(AI);
MIRBuilder.buildFrameIndex(Res, FI);
return true;
}
// Now we're in the harder dynamic case.
Type *Ty = AI.getAllocatedType();
unsigned Align =
std::max((unsigned)DL->getPrefTypeAlignment(Ty), AI.getAlignment());
unsigned NumElts = getOrCreateVReg(*AI.getArraySize());
LLT IntPtrTy = LLT::scalar(DL->getPointerSizeInBits());
if (MRI->getType(NumElts) != IntPtrTy) {
unsigned ExtElts = MRI->createGenericVirtualRegister(IntPtrTy);
MIRBuilder.buildZExtOrTrunc(ExtElts, NumElts);
NumElts = ExtElts;
}
unsigned AllocSize = MRI->createGenericVirtualRegister(IntPtrTy);
unsigned TySize = MRI->createGenericVirtualRegister(IntPtrTy);
MIRBuilder.buildConstant(TySize, DL->getTypeAllocSize(Ty));
MIRBuilder.buildMul(AllocSize, NumElts, TySize);
LLT PtrTy = LLT{*AI.getType(), *DL};
auto &TLI = *MF->getSubtarget().getTargetLowering();
unsigned SPReg = TLI.getStackPointerRegisterToSaveRestore();
unsigned SPTmp = MRI->createGenericVirtualRegister(PtrTy);
MIRBuilder.buildCopy(SPTmp, SPReg);
unsigned SPInt = MRI->createGenericVirtualRegister(IntPtrTy);
MIRBuilder.buildInstr(TargetOpcode::G_PTRTOINT).addDef(SPInt).addUse(SPTmp);
unsigned AllocInt = MRI->createGenericVirtualRegister(IntPtrTy);
MIRBuilder.buildSub(AllocInt, SPInt, AllocSize);
// Handle alignment. We have to realign if the allocation granule was smaller
// than stack alignment, or the specific alloca requires more than stack
// alignment.
unsigned StackAlign =
MF->getSubtarget().getFrameLowering()->getStackAlignment();
Align = std::max(Align, StackAlign);
if (Align > StackAlign || DL->getTypeAllocSize(Ty) % StackAlign != 0) {
// Round the size of the allocation up to the stack alignment size
// by add SA-1 to the size. This doesn't overflow because we're computing
// an address inside an alloca.
unsigned TmpSize = MRI->createGenericVirtualRegister(IntPtrTy);
unsigned AlignMinus1 = MRI->createGenericVirtualRegister(IntPtrTy);
MIRBuilder.buildConstant(AlignMinus1, Align - 1);
MIRBuilder.buildSub(TmpSize, AllocInt, AlignMinus1);
unsigned AlignedAlloc = MRI->createGenericVirtualRegister(IntPtrTy);
unsigned AlignMask = MRI->createGenericVirtualRegister(IntPtrTy);
MIRBuilder.buildConstant(AlignMask, -(uint64_t)Align);
MIRBuilder.buildAnd(AlignedAlloc, TmpSize, AlignMask);
AllocInt = AlignedAlloc;
}
unsigned DstReg = getOrCreateVReg(AI);
MIRBuilder.buildInstr(TargetOpcode::G_INTTOPTR)
.addDef(DstReg)
.addUse(AllocInt);
MIRBuilder.buildCopy(SPReg, DstReg);
MF->getFrameInfo().CreateVariableSizedObject(Align ? Align : 1, &AI);
assert(MF->getFrameInfo().hasVarSizedObjects());
return true;
}
bool IRTranslator::translatePHI(const User &U, MachineIRBuilder &MIRBuilder) {
const PHINode &PI = cast<PHINode>(U);
auto MIB = MIRBuilder.buildInstr(TargetOpcode::PHI);
MIB.addDef(getOrCreateVReg(PI));
PendingPHIs.emplace_back(&PI, MIB.getInstr());
return true;
}
void IRTranslator::finishPendingPhis() {
for (std::pair<const PHINode *, MachineInstr *> &Phi : PendingPHIs) {
const PHINode *PI = Phi.first;
MachineInstrBuilder MIB(*MF, Phi.second);
// All MachineBasicBlocks exist, add them to the PHI. We assume IRTranslator
// won't create extra control flow here, otherwise we need to find the
// dominating predecessor here (or perhaps force the weirder IRTranslators
// to provide a simple boundary).
SmallSet<const BasicBlock *, 4> HandledPreds;
for (unsigned i = 0; i < PI->getNumIncomingValues(); ++i) {
auto IRPred = PI->getIncomingBlock(i);
if (HandledPreds.count(IRPred))
continue;
HandledPreds.insert(IRPred);
unsigned ValReg = getOrCreateVReg(*PI->getIncomingValue(i));
for (auto Pred : getMachinePredBBs({IRPred, PI->getParent()})) {
assert(Pred->isSuccessor(MIB->getParent()) &&
"incorrect CFG at MachineBasicBlock level");
MIB.addUse(ValReg);
MIB.addMBB(Pred);
}
}
}
}
bool IRTranslator::translate(const Instruction &Inst) {
CurBuilder.setDebugLoc(Inst.getDebugLoc());
switch(Inst.getOpcode()) {
#define HANDLE_INST(NUM, OPCODE, CLASS) \
case Instruction::OPCODE: return translate##OPCODE(Inst, CurBuilder);
#include "llvm/IR/Instruction.def"
default:
if (!TPC->isGlobalISelAbortEnabled())
return false;
llvm_unreachable("unknown opcode");
}
}
bool IRTranslator::translate(const Constant &C, unsigned Reg) {
if (auto CI = dyn_cast<ConstantInt>(&C))
EntryBuilder.buildConstant(Reg, *CI);
else if (auto CF = dyn_cast<ConstantFP>(&C))
EntryBuilder.buildFConstant(Reg, *CF);
else if (isa<UndefValue>(C))
EntryBuilder.buildInstr(TargetOpcode::IMPLICIT_DEF).addDef(Reg);
else if (isa<ConstantPointerNull>(C))
EntryBuilder.buildConstant(Reg, 0);
else if (auto GV = dyn_cast<GlobalValue>(&C))
EntryBuilder.buildGlobalValue(Reg, GV);
else if (auto CE = dyn_cast<ConstantExpr>(&C)) {
switch(CE->getOpcode()) {
#define HANDLE_INST(NUM, OPCODE, CLASS) \
case Instruction::OPCODE: return translate##OPCODE(*CE, EntryBuilder);
#include "llvm/IR/Instruction.def"
default:
if (!TPC->isGlobalISelAbortEnabled())
return false;
llvm_unreachable("unknown opcode");
}
} else if (!TPC->isGlobalISelAbortEnabled())
return false;
else
llvm_unreachable("unhandled constant kind");
return true;
}
void IRTranslator::finalizeFunction() {
// Release the memory used by the different maps we
// needed during the translation.
PendingPHIs.clear();
ValToVReg.clear();
FrameIndices.clear();
Constants.clear();
MachinePreds.clear();
}
bool IRTranslator::runOnMachineFunction(MachineFunction &CurMF) {
MF = &CurMF;
const Function &F = *MF->getFunction();
if (F.empty())
return false;
CLI = MF->getSubtarget().getCallLowering();
CurBuilder.setMF(*MF);
EntryBuilder.setMF(*MF);
MRI = &MF->getRegInfo();
DL = &F.getParent()->getDataLayout();
TPC = &getAnalysis<TargetPassConfig>();
assert(PendingPHIs.empty() && "stale PHIs");
// Setup a separate basic-block for the arguments and constants, falling
// through to the IR-level Function's entry block.
MachineBasicBlock *EntryBB = MF->CreateMachineBasicBlock();
MF->push_back(EntryBB);
EntryBB->addSuccessor(&getOrCreateBB(F.front()));
EntryBuilder.setMBB(*EntryBB);
// Lower the actual args into this basic block.
SmallVector<unsigned, 8> VRegArgs;
for (const Argument &Arg: F.args())
VRegArgs.push_back(getOrCreateVReg(Arg));
bool Succeeded = CLI->lowerFormalArguments(EntryBuilder, F, VRegArgs);
if (!Succeeded) {
if (!TPC->isGlobalISelAbortEnabled()) {
MF->getProperties().set(
MachineFunctionProperties::Property::FailedISel);
finalizeFunction();
return false;
}
report_fatal_error("Unable to lower arguments");
}
// And translate the function!
for (const BasicBlock &BB: F) {
MachineBasicBlock &MBB = getOrCreateBB(BB);
// Set the insertion point of all the following translations to
// the end of this basic block.
CurBuilder.setMBB(MBB);
for (const Instruction &Inst: BB) {
Succeeded &= translate(Inst);
if (!Succeeded) {
if (TPC->isGlobalISelAbortEnabled())
reportTranslationError(Inst, "unable to translate instruction");
MF->getProperties().set(
MachineFunctionProperties::Property::FailedISel);
break;
}
}
}
if (Succeeded) {
finishPendingPhis();
// Now that the MachineFrameInfo has been configured, no further changes to
// the reserved registers are possible.
MRI->freezeReservedRegs(*MF);
// Merge the argument lowering and constants block with its single
// successor, the LLVM-IR entry block. We want the basic block to
// be maximal.
assert(EntryBB->succ_size() == 1 &&
"Custom BB used for lowering should have only one successor");
// Get the successor of the current entry block.
MachineBasicBlock &NewEntryBB = **EntryBB->succ_begin();
assert(NewEntryBB.pred_size() == 1 &&
"LLVM-IR entry block has a predecessor!?");
// Move all the instruction from the current entry block to the
// new entry block.
NewEntryBB.splice(NewEntryBB.begin(), EntryBB, EntryBB->begin(),
EntryBB->end());
// Update the live-in information for the new entry block.
for (const MachineBasicBlock::RegisterMaskPair &LiveIn : EntryBB->liveins())
NewEntryBB.addLiveIn(LiveIn);
NewEntryBB.sortUniqueLiveIns();
// Get rid of the now empty basic block.
EntryBB->removeSuccessor(&NewEntryBB);
MF->remove(EntryBB);
MF->DeleteMachineBasicBlock(EntryBB);
assert(&MF->front() == &NewEntryBB &&
"New entry wasn't next in the list of basic block!");
}
finalizeFunction();
return false;
}
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