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llvm-mirror/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
Reid Kleckner 3a59b4e3a9 [SEH] Implement GetExceptionCode in __except blocks 
This introduces an intrinsic called llvm.eh.exceptioncode. It is lowered
by copying the EAX value live into whatever basic block it is called
from. Obviously, this only works if you insert it late during codegen,
because otherwise mid-level passes might reschedule it.

llvm-svn: 235768
2015-04-24 20:25:05 +00:00

755 lines
28 KiB
C++
Raw Blame History

//===-- 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), NextState(0) {}
WinEHFuncInfo &FuncInfo;
int NextState;
SmallVector<ActionHandler *, 4> HandlerStack;
SmallPtrSet<const Function *, 4> VisitedHandlers;
int currentEHNumber() const {
return HandlerStack.empty() ? -1 : HandlerStack.back()->getEHState();
}
void createUnwindMapEntry(int ToState, ActionHandler *AH);
void createTryBlockMapEntry(int TryLow, int TryHigh,
ArrayRef<CatchHandler *> Handlers);
void processCallSite(ArrayRef<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<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;
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);
}
}
DeleteContainerPointers(Actions);
}
}
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(ArrayRef<ActionHandler *> Actions,
ImmutableCallSite CS) {
int FirstMismatch = 0;
for (int E = std::min(HandlerStack.size(), Actions.size()); FirstMismatch < E;
++FirstMismatch) {
if (HandlerStack[FirstMismatch]->getHandlerBlockOrFunc() !=
Actions[FirstMismatch]->getHandlerBlockOrFunc())
break;
delete Actions[FirstMismatch];
}
bool EnteringScope = (int)Actions.size() > FirstMismatch;
// 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) {
if (auto *CH = dyn_cast<CatchHandler>(HandlerStack.back())) {
PoppedCatches.push_back(CH);
} else {
// Delete cleanup handlers
delete HandlerStack.back();
}
HandlerStack.pop_back();
}
// We need to create a new state number if we are exiting a try scope and we
// will not push any more actions.
int TryHigh = NextState - 1;
if (!EnteringScope && !PoppedCatches.empty()) {
createUnwindMapEntry(currentEHNumber(), nullptr);
++NextState;
}
int LastTryLowIdx = 0;
for (int I = 0, E = PoppedCatches.size(); I != E; ++I) {
CatchHandler *CH = PoppedCatches[I];
if (I + 1 == E || CH->getEHState() != PoppedCatches[I + 1]->getEHState()) {
int TryLow = CH->getEHState();
auto Handlers =
makeArrayRef(&PoppedCatches[LastTryLowIdx], I - LastTryLowIdx + 1);
createTryBlockMapEntry(TryLow, TryHigh, Handlers);
LastTryLowIdx = I + 1;
}
}
for (CatchHandler *CH : PoppedCatches) {
if (auto *F = dyn_cast<Function>(CH->getHandlerBlockOrFunc()))
calculateStateNumbers(*F);
delete CH;
}
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]);
// FIXME: Reenable this optimization!
if (CurrActionIsCatch && LastActionWasCatch && false) {
Actions[I]->setEHState(currentEHNumber());
} else {
createUnwindMapEntry(currentEHNumber(), Actions[I]);
Actions[I]->setEHState(NextState);
NextState++;
DEBUG(dbgs() << "Creating unwind map entry for: (");
print_name(Actions[I]->getHandlerBlockOrFunc());
DEBUG(dbgs() << ", " << currentEHNumber() << ")\n");
}
HandlerStack.push_back(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.
DEBUG(dbgs() << "Calculating state numbers for: " << F.getName() << '\n');
SmallVector<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);
processCallSite(ActionList, II);
ActionList.clear();
FuncInfo.LandingPadStateMap[LPI] = currentEHNumber();
}
FuncInfo.CatchHandlerMaxState[&F] = NextState - 1;
}
/// 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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