FunctionLoweringInfo.cpp [plain text]
#include "llvm/CodeGen/FunctionLoweringInfo.h"
#include "llvm/ADT/PostOrderIterator.h"
#include "llvm/CodeGen/Analysis.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/WinEHFuncInfo.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetFrameLowering.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Target/TargetSubtargetInfo.h"
#include <algorithm>
using namespace llvm;
#define DEBUG_TYPE "function-lowering-info"
static bool isUsedOutsideOfDefiningBlock(const Instruction *I) {
if (I->use_empty()) return false;
if (isa<PHINode>(I)) return true;
const BasicBlock *BB = I->getParent();
for (const User *U : I->users())
if (cast<Instruction>(U)->getParent() != BB || isa<PHINode>(U))
return true;
return false;
}
static ISD::NodeType getPreferredExtendForValue(const Value *V) {
ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
unsigned NumOfSigned = 0, NumOfUnsigned = 0;
for (const User *U : V->users()) {
if (const auto *CI = dyn_cast<CmpInst>(U)) {
NumOfSigned += CI->isSigned();
NumOfUnsigned += CI->isUnsigned();
}
}
if (NumOfSigned > NumOfUnsigned)
ExtendKind = ISD::SIGN_EXTEND;
return ExtendKind;
}
void FunctionLoweringInfo::set(const Function &fn, MachineFunction &mf,
SelectionDAG *DAG) {
Fn = &fn;
MF = &mf;
TLI = MF->getSubtarget().getTargetLowering();
RegInfo = &MF->getRegInfo();
MachineModuleInfo &MMI = MF->getMMI();
SmallVector<ISD::OutputArg, 4> Outs;
GetReturnInfo(Fn->getReturnType(), Fn->getAttributes(), Outs, *TLI,
mf.getDataLayout());
CanLowerReturn = TLI->CanLowerReturn(Fn->getCallingConv(), *MF,
Fn->isVarArg(), Outs, Fn->getContext());
Function::const_iterator BB = Fn->begin(), EB = Fn->end();
for (; BB != EB; ++BB)
for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
I != E; ++I) {
if (const AllocaInst *AI = dyn_cast<AllocaInst>(I)) {
if (AI->isStaticAlloca()) {
const ConstantInt *CUI = cast<ConstantInt>(AI->getArraySize());
Type *Ty = AI->getAllocatedType();
uint64_t TySize = MF->getDataLayout().getTypeAllocSize(Ty);
unsigned Align =
std::max((unsigned)MF->getDataLayout().getPrefTypeAlignment(Ty),
AI->getAlignment());
TySize *= CUI->getZExtValue(); if (TySize == 0) TySize = 1;
StaticAllocaMap[AI] =
MF->getFrameInfo()->CreateStackObject(TySize, Align, false, AI);
} else {
unsigned Align =
std::max((unsigned)MF->getDataLayout().getPrefTypeAlignment(
AI->getAllocatedType()),
AI->getAlignment());
unsigned StackAlign =
MF->getSubtarget().getFrameLowering()->getStackAlignment();
if (Align <= StackAlign)
Align = 0;
MF->getFrameInfo()->CreateVariableSizedObject(Align ? Align : 1, AI);
}
}
if (isa<CallInst>(I) || isa<InvokeInst>(I)) {
ImmutableCallSite CS(&*I);
if (isa<InlineAsm>(CS.getCalledValue())) {
unsigned SP = TLI->getStackPointerRegisterToSaveRestore();
const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
std::vector<TargetLowering::AsmOperandInfo> Ops =
TLI->ParseConstraints(Fn->getParent()->getDataLayout(), TRI, CS);
for (size_t I = 0, E = Ops.size(); I != E; ++I) {
TargetLowering::AsmOperandInfo &Op = Ops[I];
if (Op.Type == InlineAsm::isClobber) {
TLI->ComputeConstraintToUse(Op, SDValue(), DAG);
std::pair<unsigned, const TargetRegisterClass *> PhysReg =
TLI->getRegForInlineAsmConstraint(TRI, Op.ConstraintCode,
Op.ConstraintVT);
if (PhysReg.first == SP)
MF->getFrameInfo()->setHasOpaqueSPAdjustment(true);
}
}
}
}
if (const auto *II = dyn_cast<IntrinsicInst>(I)) {
if (II->getIntrinsicID() == Intrinsic::vastart)
MF->getFrameInfo()->setHasVAStart(true);
}
if (const auto *CI = dyn_cast<CallInst>(I)) {
if (CI->isMustTailCall() && Fn->isVarArg())
MF->getFrameInfo()->setHasMustTailInVarArgFunc(true);
}
if (isUsedOutsideOfDefiningBlock(&*I))
if (!isa<AllocaInst>(I) || !StaticAllocaMap.count(cast<AllocaInst>(I)))
InitializeRegForValue(&*I);
if (const DbgDeclareInst *DI = dyn_cast<DbgDeclareInst>(I)) {
assert(DI->getVariable() && "Missing variable");
assert(DI->getDebugLoc() && "Missing location");
if (MMI.hasDebugInfo()) {
const Value *Address = DI->getAddress();
if (Address) {
if (const BitCastInst *BCI = dyn_cast<BitCastInst>(Address))
Address = BCI->getOperand(0);
if (const AllocaInst *AI = dyn_cast<AllocaInst>(Address)) {
DenseMap<const AllocaInst *, int>::iterator SI =
StaticAllocaMap.find(AI);
if (SI != StaticAllocaMap.end()) { int FI = SI->second;
MMI.setVariableDbgInfo(DI->getVariable(), DI->getExpression(),
FI, DI->getDebugLoc());
}
}
}
}
}
PreferredExtendType[&*I] = getPreferredExtendForValue(&*I);
}
for (BB = Fn->begin(); BB != EB; ++BB) {
if (BB->isEHPad()) {
const Instruction *I = BB->getFirstNonPHI();
if (!isa<LandingPadInst>(I)) {
MMI.setHasEHFunclets(true);
MF->getFrameInfo()->setHasOpaqueSPAdjustment(true);
}
if (isa<CatchEndPadInst>(I) || isa<CleanupEndPadInst>(I)) {
assert(&*BB->begin() == I &&
"WinEHPrepare failed to remove PHIs from imaginary BBs");
continue;
}
if (isa<CatchPadInst>(I) || isa<CleanupPadInst>(I))
assert(&*BB->begin() == I && "WinEHPrepare failed to demote PHIs");
}
MachineBasicBlock *MBB = mf.CreateMachineBasicBlock(&*BB);
MBBMap[&*BB] = MBB;
MF->push_back(MBB);
if (BB->hasAddressTaken())
MBB->setHasAddressTaken();
for (BasicBlock::const_iterator I = BB->begin();
const PHINode *PN = dyn_cast<PHINode>(I); ++I) {
if (PN->use_empty()) continue;
if (PN->getType()->isEmptyTy())
continue;
DebugLoc DL = PN->getDebugLoc();
unsigned PHIReg = ValueMap[PN];
assert(PHIReg && "PHI node does not have an assigned virtual register!");
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(*TLI, MF->getDataLayout(), PN->getType(), ValueVTs);
for (unsigned vti = 0, vte = ValueVTs.size(); vti != vte; ++vti) {
EVT VT = ValueVTs[vti];
unsigned NumRegisters = TLI->getNumRegisters(Fn->getContext(), VT);
const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
for (unsigned i = 0; i != NumRegisters; ++i)
BuildMI(MBB, DL, TII->get(TargetOpcode::PHI), PHIReg + i);
PHIReg += NumRegisters;
}
}
}
SmallVector<const LandingPadInst *, 4> LPads;
for (BB = Fn->begin(); BB != EB; ++BB) {
const Instruction *FNP = BB->getFirstNonPHI();
if (BB->isEHPad() && MBBMap.count(&*BB))
MBBMap[&*BB]->setIsEHPad();
if (const auto *LPI = dyn_cast<LandingPadInst>(FNP))
LPads.push_back(LPI);
}
if (!Fn->hasPersonalityFn())
return;
EHPersonality Personality = classifyEHPersonality(Fn->getPersonalityFn());
if (!isFuncletEHPersonality(Personality))
return;
WinEHFuncInfo &EHInfo = MMI.getWinEHFuncInfo(&fn);
if (Personality == EHPersonality::MSVC_CXX)
calculateWinCXXEHStateNumbers(&fn, EHInfo);
else if (isAsynchronousEHPersonality(Personality))
calculateSEHStateNumbers(&fn, EHInfo);
else if (Personality == EHPersonality::CoreCLR)
calculateClrEHStateNumbers(&fn, EHInfo);
calculateCatchReturnSuccessorColors(&fn, EHInfo);
for (WinEHTryBlockMapEntry &TBME : EHInfo.TryBlockMap) {
for (WinEHHandlerType &H : TBME.HandlerArray) {
if (H.CatchObj.Alloca) {
assert(StaticAllocaMap.count(H.CatchObj.Alloca));
H.CatchObj.FrameIndex = StaticAllocaMap[H.CatchObj.Alloca];
} else {
H.CatchObj.FrameIndex = INT_MAX;
}
if (H.Handler)
H.Handler = MBBMap[H.Handler.get<const BasicBlock *>()];
}
}
for (CxxUnwindMapEntry &UME : EHInfo.CxxUnwindMap)
if (UME.Cleanup)
UME.Cleanup = MBBMap[UME.Cleanup.get<const BasicBlock *>()];
for (SEHUnwindMapEntry &UME : EHInfo.SEHUnwindMap) {
const BasicBlock *BB = UME.Handler.get<const BasicBlock *>();
UME.Handler = MBBMap[BB];
}
for (ClrEHUnwindMapEntry &CME : EHInfo.ClrEHUnwindMap) {
const BasicBlock *BB = CME.Handler.get<const BasicBlock *>();
CME.Handler = MBBMap[BB];
}
if (EHInfo.EHRegNode && EHInfo.EHRegNode->getParent()->getParent() == Fn) {
assert(StaticAllocaMap.count(EHInfo.EHRegNode));
EHInfo.EHRegNodeFrameIndex = StaticAllocaMap[EHInfo.EHRegNode];
}
if (Personality == EHPersonality::MSVC_CXX ||
Personality == EHPersonality::MSVC_X86SEH) {
for (const LandingPadInst *LP : LPads) {
MachineBasicBlock *LPadMBB = MBBMap[LP->getParent()];
MMI.addWinEHState(LPadMBB, EHInfo.EHPadStateMap[LP]);
}
}
}
void FunctionLoweringInfo::clear() {
MBBMap.clear();
ValueMap.clear();
StaticAllocaMap.clear();
LiveOutRegInfo.clear();
VisitedBBs.clear();
ArgDbgValues.clear();
ByValArgFrameIndexMap.clear();
RegFixups.clear();
StatepointStackSlots.clear();
StatepointRelocatedValues.clear();
PreferredExtendType.clear();
}
unsigned FunctionLoweringInfo::CreateReg(MVT VT) {
return RegInfo->createVirtualRegister(
MF->getSubtarget().getTargetLowering()->getRegClassFor(VT));
}
unsigned FunctionLoweringInfo::CreateRegs(Type *Ty) {
const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(*TLI, MF->getDataLayout(), Ty, ValueVTs);
unsigned FirstReg = 0;
for (unsigned Value = 0, e = ValueVTs.size(); Value != e; ++Value) {
EVT ValueVT = ValueVTs[Value];
MVT RegisterVT = TLI->getRegisterType(Ty->getContext(), ValueVT);
unsigned NumRegs = TLI->getNumRegisters(Ty->getContext(), ValueVT);
for (unsigned i = 0; i != NumRegs; ++i) {
unsigned R = CreateReg(RegisterVT);
if (!FirstReg) FirstReg = R;
}
}
return FirstReg;
}
const FunctionLoweringInfo::LiveOutInfo *
FunctionLoweringInfo::GetLiveOutRegInfo(unsigned Reg, unsigned BitWidth) {
if (!LiveOutRegInfo.inBounds(Reg))
return nullptr;
LiveOutInfo *LOI = &LiveOutRegInfo[Reg];
if (!LOI->IsValid)
return nullptr;
if (BitWidth > LOI->KnownZero.getBitWidth()) {
LOI->NumSignBits = 1;
LOI->KnownZero = LOI->KnownZero.zextOrTrunc(BitWidth);
LOI->KnownOne = LOI->KnownOne.zextOrTrunc(BitWidth);
}
return LOI;
}
void FunctionLoweringInfo::ComputePHILiveOutRegInfo(const PHINode *PN) {
Type *Ty = PN->getType();
if (!Ty->isIntegerTy() || Ty->isVectorTy())
return;
SmallVector<EVT, 1> ValueVTs;
ComputeValueVTs(*TLI, MF->getDataLayout(), Ty, ValueVTs);
assert(ValueVTs.size() == 1 &&
"PHIs with non-vector integer types should have a single VT.");
EVT IntVT = ValueVTs[0];
if (TLI->getNumRegisters(PN->getContext(), IntVT) != 1)
return;
IntVT = TLI->getTypeToTransformTo(PN->getContext(), IntVT);
unsigned BitWidth = IntVT.getSizeInBits();
unsigned DestReg = ValueMap[PN];
if (!TargetRegisterInfo::isVirtualRegister(DestReg))
return;
LiveOutRegInfo.grow(DestReg);
LiveOutInfo &DestLOI = LiveOutRegInfo[DestReg];
Value *V = PN->getIncomingValue(0);
if (isa<UndefValue>(V) || isa<ConstantExpr>(V)) {
DestLOI.NumSignBits = 1;
APInt Zero(BitWidth, 0);
DestLOI.KnownZero = Zero;
DestLOI.KnownOne = Zero;
return;
}
if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
APInt Val = CI->getValue().zextOrTrunc(BitWidth);
DestLOI.NumSignBits = Val.getNumSignBits();
DestLOI.KnownZero = ~Val;
DestLOI.KnownOne = Val;
} else {
assert(ValueMap.count(V) && "V should have been placed in ValueMap when its"
"CopyToReg node was created.");
unsigned SrcReg = ValueMap[V];
if (!TargetRegisterInfo::isVirtualRegister(SrcReg)) {
DestLOI.IsValid = false;
return;
}
const LiveOutInfo *SrcLOI = GetLiveOutRegInfo(SrcReg, BitWidth);
if (!SrcLOI) {
DestLOI.IsValid = false;
return;
}
DestLOI = *SrcLOI;
}
assert(DestLOI.KnownZero.getBitWidth() == BitWidth &&
DestLOI.KnownOne.getBitWidth() == BitWidth &&
"Masks should have the same bit width as the type.");
for (unsigned i = 1, e = PN->getNumIncomingValues(); i != e; ++i) {
Value *V = PN->getIncomingValue(i);
if (isa<UndefValue>(V) || isa<ConstantExpr>(V)) {
DestLOI.NumSignBits = 1;
APInt Zero(BitWidth, 0);
DestLOI.KnownZero = Zero;
DestLOI.KnownOne = Zero;
return;
}
if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
APInt Val = CI->getValue().zextOrTrunc(BitWidth);
DestLOI.NumSignBits = std::min(DestLOI.NumSignBits, Val.getNumSignBits());
DestLOI.KnownZero &= ~Val;
DestLOI.KnownOne &= Val;
continue;
}
assert(ValueMap.count(V) && "V should have been placed in ValueMap when "
"its CopyToReg node was created.");
unsigned SrcReg = ValueMap[V];
if (!TargetRegisterInfo::isVirtualRegister(SrcReg)) {
DestLOI.IsValid = false;
return;
}
const LiveOutInfo *SrcLOI = GetLiveOutRegInfo(SrcReg, BitWidth);
if (!SrcLOI) {
DestLOI.IsValid = false;
return;
}
DestLOI.NumSignBits = std::min(DestLOI.NumSignBits, SrcLOI->NumSignBits);
DestLOI.KnownZero &= SrcLOI->KnownZero;
DestLOI.KnownOne &= SrcLOI->KnownOne;
}
}
void FunctionLoweringInfo::setArgumentFrameIndex(const Argument *A,
int FI) {
ByValArgFrameIndexMap[A] = FI;
}
int FunctionLoweringInfo::getArgumentFrameIndex(const Argument *A) {
DenseMap<const Argument *, int>::iterator I =
ByValArgFrameIndexMap.find(A);
if (I != ByValArgFrameIndexMap.end())
return I->second;
DEBUG(dbgs() << "Argument does not have assigned frame index!\n");
return 0;
}
unsigned FunctionLoweringInfo::getCatchPadExceptionPointerVReg(
const Value *CPI, const TargetRegisterClass *RC) {
MachineRegisterInfo &MRI = MF->getRegInfo();
auto I = CatchPadExceptionPointers.insert({CPI, 0});
unsigned &VReg = I.first->second;
if (I.second)
VReg = MRI.createVirtualRegister(RC);
assert(VReg && "null vreg in exception pointer table!");
return VReg;
}
void llvm::ComputeUsesVAFloatArgument(const CallInst &I,
MachineModuleInfo *MMI)
{
FunctionType *FT = cast<FunctionType>(
I.getCalledValue()->getType()->getContainedType(0));
if (FT->isVarArg() && !MMI->usesVAFloatArgument()) {
for (unsigned i = 0, e = I.getNumArgOperands(); i != e; ++i) {
Type* T = I.getArgOperand(i)->getType();
for (auto i : post_order(T)) {
if (i->isFloatingPointTy()) {
MMI->setUsesVAFloatArgument(true);
return;
}
}
}
}
}
void llvm::AddLandingPadInfo(const LandingPadInst &I, MachineModuleInfo &MMI,
MachineBasicBlock *MBB) {
if (const auto *PF = dyn_cast<Function>(
I.getParent()->getParent()->getPersonalityFn()->stripPointerCasts()))
MMI.addPersonality(PF);
if (I.isCleanup())
MMI.addCleanup(MBB);
for (unsigned i = I.getNumClauses(); i != 0; --i) {
Value *Val = I.getClause(i - 1);
if (I.isCatch(i - 1)) {
MMI.addCatchTypeInfo(MBB,
dyn_cast<GlobalValue>(Val->stripPointerCasts()));
} else {
Constant *CVal = cast<Constant>(Val);
SmallVector<const GlobalValue*, 4> FilterList;
for (User::op_iterator
II = CVal->op_begin(), IE = CVal->op_end(); II != IE; ++II)
FilterList.push_back(cast<GlobalValue>((*II)->stripPointerCasts()));
MMI.addFilterTypeInfo(MBB, FilterList);
}
}
}
unsigned FunctionLoweringInfo::findSwiftErrorVReg(const MachineBasicBlock *MBB,
const Value* Val) const {
unsigned End = SwiftErrorVals.size();
unsigned Index = End;
for (unsigned I = 0; I < End; I++)
if (SwiftErrorVals[I] == Val) {
Index = I;
break;
}
assert(Index < End && "Can't find value in SwiftErrorVals");
return SwiftErrorMap.lookup(MBB)[Index];
}
void FunctionLoweringInfo::setSwiftErrorVReg(const MachineBasicBlock *MBB,
const Value* Val, unsigned VReg) {
unsigned End = SwiftErrorVals.size();
unsigned Index = End;
for (unsigned I = 0, E = SwiftErrorVals.size(); I < E; I++)
if (SwiftErrorVals[I] == Val) {
Index = I;
break;
}
assert(Index < End && "Can't find value in SwiftErrorVals");
SwiftErrorMap[MBB][Index] = VReg;
}