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llvm-6502/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
Benjamin Kramer 11ba91f321 [WinEH] Push unique_ptr through the Action interface. 
This was the source of many leaks in the past, this should fix them once and
for all.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237524 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-16 15:40:03 +00:00

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//===-- FunctionLoweringInfo.cpp ------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This implements routines for translating functions from LLVM IR into
// Machine IR.
//
//===----------------------------------------------------------------------===//
#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"
/// isUsedOutsideOfDefiningBlock - Return true if this instruction is used by
/// PHI nodes or outside of the basic block that defines it, or used by a
/// switch or atomic instruction, which may expand to multiple basic blocks.
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) {
// For the users of the source value being used for compare instruction, if
// the number of signed predicate is greater than unsigned predicate, we
// prefer to use SIGN_EXTEND.
//
// With this optimization, we would be able to reduce some redundant sign or
// zero extension instruction, and eventually more machine CSE opportunities
// can be exposed.
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;
}
namespace {
struct WinEHNumbering {
WinEHNumbering(WinEHFuncInfo &FuncInfo) : FuncInfo(FuncInfo),
CurrentBaseState(-1), NextState(0) {}
WinEHFuncInfo &FuncInfo;
int CurrentBaseState;
int NextState;
SmallVector<std::unique_ptr<ActionHandler>, 4> HandlerStack;
SmallPtrSet<const Function *, 4> VisitedHandlers;
int currentEHNumber() const {
return HandlerStack.empty() ? CurrentBaseState : HandlerStack.back()->getEHState();
}
void createUnwindMapEntry(int ToState, ActionHandler *AH);
void createTryBlockMapEntry(int TryLow, int TryHigh,
ArrayRef<CatchHandler *> Handlers);
void processCallSite(MutableArrayRef<std::unique_ptr<ActionHandler>> Actions,
ImmutableCallSite CS);
void calculateStateNumbers(const Function &F);
};
}
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();
// Check whether the function can return without sret-demotion.
SmallVector<ISD::OutputArg, 4> Outs;
GetReturnInfo(Fn->getReturnType(), Fn->getAttributes(), Outs, *TLI);
CanLowerReturn = TLI->CanLowerReturn(Fn->getCallingConv(), *MF,
Fn->isVarArg(), Outs, Fn->getContext());
// Initialize the mapping of values to registers. This is only set up for
// instruction values that are used outside of the block that defines
// them.
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)) {
// Static allocas can be folded into the initial stack frame adjustment.
if (AI->isStaticAlloca()) {
const ConstantInt *CUI = cast<ConstantInt>(AI->getArraySize());
Type *Ty = AI->getAllocatedType();
uint64_t TySize = TLI->getDataLayout()->getTypeAllocSize(Ty);
unsigned Align =
std::max((unsigned)TLI->getDataLayout()->getPrefTypeAlignment(Ty),
AI->getAlignment());
TySize *= CUI->getZExtValue(); // Get total allocated size.
if (TySize == 0) TySize = 1; // Don't create zero-sized stack objects.
StaticAllocaMap[AI] =
MF->getFrameInfo()->CreateStackObject(TySize, Align, false, AI);
} else {
unsigned Align = std::max(
(unsigned)TLI->getDataLayout()->getPrefTypeAlignment(
AI->getAllocatedType()),
AI->getAlignment());
unsigned StackAlign =
MF->getSubtarget().getFrameLowering()->getStackAlignment();
if (Align <= StackAlign)
Align = 0;
// Inform the Frame Information that we have variable-sized objects.
MF->getFrameInfo()->CreateVariableSizedObject(Align ? Align : 1, AI);
}
}
// Look for inline asm that clobbers the SP register.
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(TRI, CS);
for (size_t I = 0, E = Ops.size(); I != E; ++I) {
TargetLowering::AsmOperandInfo &Op = Ops[I];
if (Op.Type == InlineAsm::isClobber) {
// Clobbers don't have SDValue operands, hence SDValue().
TLI->ComputeConstraintToUse(Op, SDValue(), DAG);
std::pair<unsigned, const TargetRegisterClass *> PhysReg =
TLI->getRegForInlineAsmConstraint(TRI, Op.ConstraintCode,
Op.ConstraintVT);
if (PhysReg.first == SP)
MF->getFrameInfo()->setHasInlineAsmWithSPAdjust(true);
}
}
}
}
// Look for calls to the @llvm.va_start intrinsic. We can omit some
// prologue boilerplate for variadic functions that don't examine their
// arguments.
if (const auto *II = dyn_cast<IntrinsicInst>(I)) {
if (II->getIntrinsicID() == Intrinsic::vastart)
MF->getFrameInfo()->setHasVAStart(true);
}
// If we have a musttail call in a variadic funciton, we need to ensure we
// forward implicit register parameters.
if (const auto *CI = dyn_cast<CallInst>(I)) {
if (CI->isMustTailCall() && Fn->isVarArg())
MF->getFrameInfo()->setHasMustTailInVarArgFunc(true);
}
// Mark values used outside their block as exported, by allocating
// a virtual register for them.
if (isUsedOutsideOfDefiningBlock(I))
if (!isa<AllocaInst>(I) ||
!StaticAllocaMap.count(cast<AllocaInst>(I)))
InitializeRegForValue(I);
// Collect llvm.dbg.declare information. This is done now instead of
// during the initial isel pass through the IR so that it is done
// in a predictable order.
if (const DbgDeclareInst *DI = dyn_cast<DbgDeclareInst>(I)) {
assert(DI->getVariable() && "Missing variable");
assert(DI->getDebugLoc() && "Missing location");
if (MMI.hasDebugInfo()) {
// Don't handle byval struct arguments or VLAs, for example.
// Non-byval arguments are handled here (they refer to the stack
// temporary alloca at this point).
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()) { // Check for VLAs.
int FI = SI->second;
MMI.setVariableDbgInfo(DI->getVariable(), DI->getExpression(),
FI, DI->getDebugLoc());
}
}
}
}
}
// Decide the preferred extend type for a value.
PreferredExtendType[I] = getPreferredExtendForValue(I);
}
// Create an initial MachineBasicBlock for each LLVM BasicBlock in F. This
// also creates the initial PHI MachineInstrs, though none of the input
// operands are populated.
for (BB = Fn->begin(); BB != EB; ++BB) {
MachineBasicBlock *MBB = mf.CreateMachineBasicBlock(BB);
MBBMap[BB] = MBB;
MF->push_back(MBB);
// Transfer the address-taken flag. This is necessary because there could
// be multiple MachineBasicBlocks corresponding to one BasicBlock, and only
// the first one should be marked.
if (BB->hasAddressTaken())
MBB->setHasAddressTaken();
// Create Machine PHI nodes for LLVM PHI nodes, lowering them as
// appropriate.
for (BasicBlock::const_iterator I = BB->begin();
const PHINode *PN = dyn_cast<PHINode>(I); ++I) {
if (PN->use_empty()) continue;
// Skip empty types
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, 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;
}
}
}
// Mark landing pad blocks.
SmallVector<const LandingPadInst *, 4> LPads;
for (BB = Fn->begin(); BB != EB; ++BB) {
if (const auto *Invoke = dyn_cast<InvokeInst>(BB->getTerminator()))
MBBMap[Invoke->getSuccessor(1)]->setIsLandingPad();
if (BB->isLandingPad())
LPads.push_back(BB->getLandingPadInst());
}
// If this is an MSVC EH personality, we need to do a bit more work.
EHPersonality Personality = EHPersonality::Unknown;
if (!LPads.empty())
Personality = classifyEHPersonality(LPads.back()->getPersonalityFn());
if (!isMSVCEHPersonality(Personality))
return;
WinEHFuncInfo *EHInfo = nullptr;
if (Personality == EHPersonality::MSVC_Win64SEH) {
addSEHHandlersForLPads(LPads);
} else if (Personality == EHPersonality::MSVC_CXX) {
const Function *WinEHParentFn = MMI.getWinEHParent(&fn);
EHInfo = &MMI.getWinEHFuncInfo(WinEHParentFn);
if (EHInfo->LandingPadStateMap.empty()) {
WinEHNumbering Num(*EHInfo);
Num.calculateStateNumbers(*WinEHParentFn);
// Pop everything on the handler stack.
Num.processCallSite(None, ImmutableCallSite());
}
// Copy the state numbers to LandingPadInfo for the current function, which
// could be a handler or the parent.
for (const LandingPadInst *LP : LPads) {
MachineBasicBlock *LPadMBB = MBBMap[LP->getParent()];
MMI.addWinEHState(LPadMBB, EHInfo->LandingPadStateMap[LP]);
}
}
}
void FunctionLoweringInfo::addSEHHandlersForLPads(
ArrayRef<const LandingPadInst *> LPads) {
MachineModuleInfo &MMI = MF->getMMI();
// Iterate over all landing pads with llvm.eh.actions calls.
for (const LandingPadInst *LP : LPads) {
const IntrinsicInst *ActionsCall =
dyn_cast<IntrinsicInst>(LP->getNextNode());
if (!ActionsCall ||
ActionsCall->getIntrinsicID() != Intrinsic::eh_actions)
continue;
// Parse the llvm.eh.actions call we found.
MachineBasicBlock *LPadMBB = MBBMap[LP->getParent()];
SmallVector<std::unique_ptr<ActionHandler>, 4> Actions;
parseEHActions(ActionsCall, Actions);
// Iterate EH actions from most to least precedence, which means
// iterating in reverse.
for (auto I = Actions.rbegin(), E = Actions.rend(); I != E; ++I) {
ActionHandler *Action = I->get();
if (auto *CH = dyn_cast<CatchHandler>(Action)) {
const auto *Filter =
dyn_cast<Function>(CH->getSelector()->stripPointerCasts());
assert((Filter || CH->getSelector()->isNullValue()) &&
"expected function or catch-all");
const auto *RecoverBA =
cast<BlockAddress>(CH->getHandlerBlockOrFunc());
MMI.addSEHCatchHandler(LPadMBB, Filter, RecoverBA);
} else {
assert(isa<CleanupHandler>(Action));
const auto *Fini = cast<Function>(Action->getHandlerBlockOrFunc());
MMI.addSEHCleanupHandler(LPadMBB, Fini);
}
}
}
}
void WinEHNumbering::createUnwindMapEntry(int ToState, ActionHandler *AH) {
WinEHUnwindMapEntry UME;
UME.ToState = ToState;
if (auto *CH = dyn_cast_or_null<CleanupHandler>(AH))
UME.Cleanup = cast<Function>(CH->getHandlerBlockOrFunc());
else
UME.Cleanup = nullptr;
FuncInfo.UnwindMap.push_back(UME);
}
void WinEHNumbering::createTryBlockMapEntry(int TryLow, int TryHigh,
ArrayRef<CatchHandler *> Handlers) {
WinEHTryBlockMapEntry TBME;
TBME.TryLow = TryLow;
TBME.TryHigh = TryHigh;
assert(TBME.TryLow <= TBME.TryHigh);
for (CatchHandler *CH : Handlers) {
WinEHHandlerType HT;
if (CH->getSelector()->isNullValue()) {
HT.Adjectives = 0x40;
HT.TypeDescriptor = nullptr;
} else {
auto *GV = cast<GlobalVariable>(CH->getSelector()->stripPointerCasts());
// Selectors are always pointers to GlobalVariables with 'struct' type.
// The struct has two fields, adjectives and a type descriptor.
auto *CS = cast<ConstantStruct>(GV->getInitializer());
HT.Adjectives =
cast<ConstantInt>(CS->getAggregateElement(0U))->getZExtValue();
HT.TypeDescriptor =
cast<GlobalVariable>(CS->getAggregateElement(1)->stripPointerCasts());
}
HT.Handler = cast<Function>(CH->getHandlerBlockOrFunc());
HT.CatchObjRecoverIdx = CH->getExceptionVarIndex();
TBME.HandlerArray.push_back(HT);
}
FuncInfo.TryBlockMap.push_back(TBME);
}
static void print_name(const Value *V) {
#ifndef NDEBUG
if (!V) {
DEBUG(dbgs() << "null");
return;
}
if (const auto *F = dyn_cast<Function>(V))
DEBUG(dbgs() << F->getName());
else
DEBUG(V->dump());
#endif
}
void WinEHNumbering::processCallSite(
MutableArrayRef<std::unique_ptr<ActionHandler>> Actions,
ImmutableCallSite CS) {
DEBUG(dbgs() << "processCallSite (EH state = " << currentEHNumber()
<< ") for: ");
print_name(CS ? CS.getCalledValue() : nullptr);
DEBUG(dbgs() << '\n');
DEBUG(dbgs() << "HandlerStack: \n");
for (int I = 0, E = HandlerStack.size(); I < E; ++I) {
DEBUG(dbgs() << " ");
print_name(HandlerStack[I]->getHandlerBlockOrFunc());
DEBUG(dbgs() << '\n');
}
DEBUG(dbgs() << "Actions: \n");
for (int I = 0, E = Actions.size(); I < E; ++I) {
DEBUG(dbgs() << " ");
print_name(Actions[I]->getHandlerBlockOrFunc());
DEBUG(dbgs() << '\n');
}
int FirstMismatch = 0;
for (int E = std::min(HandlerStack.size(), Actions.size()); FirstMismatch < E;
++FirstMismatch) {
if (HandlerStack[FirstMismatch]->getHandlerBlockOrFunc() !=
Actions[FirstMismatch]->getHandlerBlockOrFunc())
break;
}
// Don't recurse while we are looping over the handler stack. Instead, defer
// the numbering of the catch handlers until we are done popping.
SmallVector<CatchHandler *, 4> PoppedCatches;
for (int I = HandlerStack.size() - 1; I >= FirstMismatch; --I) {
std::unique_ptr<ActionHandler> Handler = HandlerStack.pop_back_val();
if (isa<CatchHandler>(Handler.get()))
PoppedCatches.push_back(cast<CatchHandler>(Handler.release()));
}
int TryHigh = NextState - 1;
int LastTryLowIdx = 0;
for (int I = 0, E = PoppedCatches.size(); I != E; ++I) {
CatchHandler *CH = PoppedCatches[I];
DEBUG(dbgs() << "Popped handler with state " << CH->getEHState() << "\n");
if (I + 1 == E || CH->getEHState() != PoppedCatches[I + 1]->getEHState()) {
int TryLow = CH->getEHState();
auto Handlers =
makeArrayRef(&PoppedCatches[LastTryLowIdx], I - LastTryLowIdx + 1);
DEBUG(dbgs() << "createTryBlockMapEntry(" << TryLow << ", " << TryHigh);
for (size_t J = 0; J < Handlers.size(); ++J) {
DEBUG(dbgs() << ", ");
print_name(Handlers[J]->getHandlerBlockOrFunc());
}
DEBUG(dbgs() << ")\n");
createTryBlockMapEntry(TryLow, TryHigh, Handlers);
LastTryLowIdx = I + 1;
}
}
for (CatchHandler *CH : PoppedCatches) {
if (auto *F = dyn_cast<Function>(CH->getHandlerBlockOrFunc())) {
DEBUG(dbgs() << "Assigning base state " << NextState << " to ");
print_name(F);
DEBUG(dbgs() << '\n');
FuncInfo.HandlerBaseState[F] = NextState;
DEBUG(dbgs() << "createUnwindMapEntry(" << currentEHNumber()
<< ", null)\n");
createUnwindMapEntry(currentEHNumber(), nullptr);
++NextState;
calculateStateNumbers(*F);
}
delete CH;
}
// The handler functions may have pushed actions onto the handler stack
// that we expected to push here. Compare the handler stack to our
// actions again to check for that possibility.
if (HandlerStack.size() > (size_t)FirstMismatch) {
for (int E = std::min(HandlerStack.size(), Actions.size());
FirstMismatch < E; ++FirstMismatch) {
if (HandlerStack[FirstMismatch]->getHandlerBlockOrFunc() !=
Actions[FirstMismatch]->getHandlerBlockOrFunc())
break;
}
}
DEBUG(dbgs() << "Pushing actions for CallSite: ");
print_name(CS ? CS.getCalledValue() : nullptr);
DEBUG(dbgs() << '\n');
bool LastActionWasCatch = false;
for (size_t I = FirstMismatch; I != Actions.size(); ++I) {
// We can reuse eh states when pushing two catches for the same invoke.
bool CurrActionIsCatch = isa<CatchHandler>(Actions[I].get());
// FIXME: Reenable this optimization!
if (CurrActionIsCatch && LastActionWasCatch && false) {
DEBUG(dbgs() << "setEHState for handler to " << currentEHNumber()
<< "\n");
Actions[I]->setEHState(currentEHNumber());
} else {
DEBUG(dbgs() << "createUnwindMapEntry(" << currentEHNumber() << ", ");
print_name(Actions[I]->getHandlerBlockOrFunc());
DEBUG(dbgs() << ")\n");
createUnwindMapEntry(currentEHNumber(), Actions[I].get());
DEBUG(dbgs() << "setEHState for handler to " << NextState << "\n");
Actions[I]->setEHState(NextState);
NextState++;
}
HandlerStack.push_back(std::move(Actions[I]));
LastActionWasCatch = CurrActionIsCatch;
}
DEBUG(dbgs() << "In EHState " << currentEHNumber() << " for CallSite: ");
print_name(CS ? CS.getCalledValue() : nullptr);
DEBUG(dbgs() << '\n');
}
void WinEHNumbering::calculateStateNumbers(const Function &F) {
auto I = VisitedHandlers.insert(&F);
if (!I.second)
return; // We've already visited this handler, don't renumber it.
int OldBaseState = CurrentBaseState;
if (FuncInfo.HandlerBaseState.count(&F)) {
CurrentBaseState = FuncInfo.HandlerBaseState[&F];
}
DEBUG(dbgs() << "Calculating state numbers for: " << F.getName() << '\n');
SmallVector<std::unique_ptr<ActionHandler>, 4> ActionList;
for (const BasicBlock &BB : F) {
for (const Instruction &I : BB) {
const auto *CI = dyn_cast<CallInst>(&I);
if (!CI || CI->doesNotThrow())
continue;
processCallSite(None, CI);
}
const auto *II = dyn_cast<InvokeInst>(BB.getTerminator());
if (!II)
continue;
const LandingPadInst *LPI = II->getLandingPadInst();
auto *ActionsCall = dyn_cast<IntrinsicInst>(LPI->getNextNode());
if (!ActionsCall)
continue;
assert(ActionsCall->getIntrinsicID() == Intrinsic::eh_actions);
parseEHActions(ActionsCall, ActionList);
if (ActionList.empty())
continue;
processCallSite(ActionList, II);
ActionList.clear();
FuncInfo.LandingPadStateMap[LPI] = currentEHNumber();
DEBUG(dbgs() << "Assigning state " << currentEHNumber()
<< " to landing pad at " << LPI->getParent()->getName()
<< '\n');
}
FuncInfo.CatchHandlerMaxState[&F] = NextState - 1;
CurrentBaseState = OldBaseState;
}
/// clear - Clear out all the function-specific state. This returns this
/// FunctionLoweringInfo to an empty state, ready to be used for a
/// different function.
void FunctionLoweringInfo::clear() {
assert(CatchInfoFound.size() == CatchInfoLost.size() &&
"Not all catch info was assigned to a landing pad!");
MBBMap.clear();
ValueMap.clear();
StaticAllocaMap.clear();
#ifndef NDEBUG
CatchInfoLost.clear();
CatchInfoFound.clear();
#endif
LiveOutRegInfo.clear();
VisitedBBs.clear();
ArgDbgValues.clear();
ByValArgFrameIndexMap.clear();
RegFixups.clear();
StatepointStackSlots.clear();
PreferredExtendType.clear();
}
/// CreateReg - Allocate a single virtual register for the given type.
unsigned FunctionLoweringInfo::CreateReg(MVT VT) {
return RegInfo->createVirtualRegister(
MF->getSubtarget().getTargetLowering()->getRegClassFor(VT));
}
/// CreateRegs - Allocate the appropriate number of virtual registers of
/// the correctly promoted or expanded types. Assign these registers
/// consecutive vreg numbers and return the first assigned number.
///
/// In the case that the given value has struct or array type, this function
/// will assign registers for each member or element.
///
unsigned FunctionLoweringInfo::CreateRegs(Type *Ty) {
const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(*TLI, 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;
}
/// GetLiveOutRegInfo - Gets LiveOutInfo for a register, returning NULL if the
/// register is a PHI destination and the PHI's LiveOutInfo is not valid. If
/// the register's LiveOutInfo is for a smaller bit width, it is extended to
/// the larger bit width by zero extension. The bit width must be no smaller
/// than the LiveOutInfo's existing bit width.
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;
}
/// ComputePHILiveOutRegInfo - Compute LiveOutInfo for a PHI's destination
/// register based on the LiveOutInfo of its operands.
void FunctionLoweringInfo::ComputePHILiveOutRegInfo(const PHINode *PN) {
Type *Ty = PN->getType();
if (!Ty->isIntegerTy() || Ty->isVectorTy())
return;
SmallVector<EVT, 1> ValueVTs;
ComputeValueVTs(*TLI, 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;
}
}
/// setArgumentFrameIndex - Record frame index for the byval
/// argument. This overrides previous frame index entry for this argument,
/// if any.
void FunctionLoweringInfo::setArgumentFrameIndex(const Argument *A,
int FI) {
ByValArgFrameIndexMap[A] = FI;
}
/// getArgumentFrameIndex - Get frame index for the byval argument.
/// If the argument does not have any assigned frame index then 0 is
/// returned.
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;
}
/// ComputeUsesVAFloatArgument - Determine if any floating-point values are
/// being passed to this variadic function, and set the MachineModuleInfo's
/// usesVAFloatArgument flag if so. This flag is used to emit an undefined
/// reference to _fltused on Windows, which will link in MSVCRT's
/// floating-point support.
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;
}
}
}
}
}
/// AddLandingPadInfo - Extract the exception handling information from the
/// landingpad instruction and add them to the specified machine module info.
void llvm::AddLandingPadInfo(const LandingPadInst &I, MachineModuleInfo &MMI,
MachineBasicBlock *MBB) {
MMI.addPersonality(MBB,
cast<Function>(I.getPersonalityFn()->stripPointerCasts()));
if (I.isCleanup())
MMI.addCleanup(MBB);
// FIXME: New EH - Add the clauses in reverse order. This isn't 100% correct,
// but we need to do it this way because of how the DWARF EH emitter
// processes the clauses.
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 {
// Add filters in a list.
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);
}
}
}
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