#define DEBUG_TYPE "jit"
#include "JIT.h"
#include "JITDwarfEmitter.h"
#include "llvm/Constants.h"
#include "llvm/Module.h"
#include "llvm/DerivedTypes.h"
#include "llvm/CodeGen/MachineCodeEmitter.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRelocation.h"
#include "llvm/ExecutionEngine/JITMemoryManager.h"
#include "llvm/ExecutionEngine/GenericValue.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetJITInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/MutexGuard.h"
#include "llvm/Support/ValueHandle.h"
#include "llvm/System/Disassembler.h"
#include "llvm/System/Memory.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include <algorithm>
#ifndef NDEBUG
#include <iomanip>
#endif
using namespace llvm;
STATISTIC(NumBytes, "Number of bytes of machine code compiled");
STATISTIC(NumRelos, "Number of relocations applied");
static JIT *TheJIT = 0;
namespace {
class JITResolverState {
private:
std::map<AssertingVH<Function>, void*> FunctionToStubMap;
std::map<void*, AssertingVH<Function> > StubToFunctionMap;
std::map<GlobalValue*, void*> GlobalToIndirectSymMap;
public:
std::map<AssertingVH<Function>, void*>& getFunctionToStubMap(const MutexGuard& locked) {
assert(locked.holds(TheJIT->lock));
return FunctionToStubMap;
}
std::map<void*, AssertingVH<Function> >& getStubToFunctionMap(const MutexGuard& locked) {
assert(locked.holds(TheJIT->lock));
return StubToFunctionMap;
}
std::map<GlobalValue*, void*>&
getGlobalToIndirectSymMap(const MutexGuard& locked) {
assert(locked.holds(TheJIT->lock));
return GlobalToIndirectSymMap;
}
};
class JITResolver {
TargetJITInfo::LazyResolverFn LazyResolverFn;
JITResolverState state;
std::map<void*, void*> ExternalFnToStubMap;
std::map<void*, unsigned> revGOTMap;
unsigned nextGOTIndex;
static JITResolver *TheJITResolver;
public:
explicit JITResolver(JIT &jit) : nextGOTIndex(0) {
TheJIT = &jit;
LazyResolverFn = jit.getJITInfo().getLazyResolverFunction(JITCompilerFn);
assert(TheJITResolver == 0 && "Multiple JIT resolvers?");
TheJITResolver = this;
}
~JITResolver() {
TheJITResolver = 0;
}
void *getFunctionStubIfAvailable(Function *F);
void *getFunctionStub(Function *F);
void *getExternalFunctionStub(void *FnAddr);
void *getGlobalValueIndirectSym(GlobalValue *V, void *GVAddress);
void *AddCallbackAtLocation(Function *F, void *Location) {
MutexGuard locked(TheJIT->lock);
state.getStubToFunctionMap(locked)[Location] = F;
return (void*)(intptr_t)LazyResolverFn;
}
void getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs,
SmallVectorImpl<void*> &Ptrs);
GlobalValue *invalidateStub(void *Stub);
unsigned getGOTIndexForAddr(void *addr);
static void *JITCompilerFn(void *Stub);
};
}
JITResolver *JITResolver::TheJITResolver = 0;
void *JITResolver::getFunctionStubIfAvailable(Function *F) {
MutexGuard locked(TheJIT->lock);
void *&Stub = state.getFunctionToStubMap(locked)[F];
return Stub;
}
void *JITResolver::getFunctionStub(Function *F) {
MutexGuard locked(TheJIT->lock);
void *&Stub = state.getFunctionToStubMap(locked)[F];
if (Stub) return Stub;
void *Actual = TheJIT->isLazyCompilationDisabled()
? (void *)0 : (void *)(intptr_t)LazyResolverFn;
if (F->isDeclaration() && !F->hasNotBeenReadFromBitcode()) {
Actual = TheJIT->getPointerToFunction(F);
if (!Actual && !TheJIT->areDlsymStubsEnabled()) return 0;
}
Stub = TheJIT->getJITInfo().emitFunctionStub(F, Actual,
*TheJIT->getCodeEmitter());
if (Actual != (void*)(intptr_t)LazyResolverFn) {
TheJIT->updateGlobalMapping(F, Stub);
}
DOUT << "JIT: Stub emitted at [" << Stub << "] for function '"
<< F->getName() << "'\n";
state.getStubToFunctionMap(locked)[Stub] = F;
if (!Actual && TheJIT->isLazyCompilationDisabled())
if (!F->isDeclaration() || F->hasNotBeenReadFromBitcode())
TheJIT->addPendingFunction(F);
return Stub;
}
void *JITResolver::getGlobalValueIndirectSym(GlobalValue *GV, void *GVAddress) {
MutexGuard locked(TheJIT->lock);
void *&IndirectSym = state.getGlobalToIndirectSymMap(locked)[GV];
if (IndirectSym) return IndirectSym;
IndirectSym = TheJIT->getJITInfo().emitGlobalValueIndirectSym(GV, GVAddress,
*TheJIT->getCodeEmitter());
DOUT << "JIT: Indirect symbol emitted at [" << IndirectSym << "] for GV '"
<< GV->getName() << "'\n";
return IndirectSym;
}
void *JITResolver::getExternalFunctionStub(void *FnAddr) {
void *&Stub = ExternalFnToStubMap[FnAddr];
if (Stub) return Stub;
Stub = TheJIT->getJITInfo().emitFunctionStub(0, FnAddr,
*TheJIT->getCodeEmitter());
DOUT << "JIT: Stub emitted at [" << Stub
<< "] for external function at '" << FnAddr << "'\n";
return Stub;
}
unsigned JITResolver::getGOTIndexForAddr(void* addr) {
unsigned idx = revGOTMap[addr];
if (!idx) {
idx = ++nextGOTIndex;
revGOTMap[addr] = idx;
DOUT << "JIT: Adding GOT entry " << idx << " for addr [" << addr << "]\n";
}
return idx;
}
void JITResolver::getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs,
SmallVectorImpl<void*> &Ptrs) {
MutexGuard locked(TheJIT->lock);
std::map<AssertingVH<Function>,void*> &FM =state.getFunctionToStubMap(locked);
std::map<GlobalValue*,void*> &GM = state.getGlobalToIndirectSymMap(locked);
for (std::map<AssertingVH<Function>,void*>::iterator i = FM.begin(),
e = FM.end(); i != e; ++i) {
Function *F = i->first;
if (F->isDeclaration() && F->hasExternalLinkage()) {
GVs.push_back(i->first);
Ptrs.push_back(i->second);
}
}
for (std::map<GlobalValue*,void*>::iterator i = GM.begin(), e = GM.end();
i != e; ++i) {
GVs.push_back(i->first);
Ptrs.push_back(i->second);
}
}
GlobalValue *JITResolver::invalidateStub(void *Stub) {
MutexGuard locked(TheJIT->lock);
std::map<AssertingVH<Function>,void*> &FM =state.getFunctionToStubMap(locked);
std::map<void*,AssertingVH<Function> > &SM=state.getStubToFunctionMap(locked);
std::map<GlobalValue*,void*> &GM = state.getGlobalToIndirectSymMap(locked);
if (SM.find(Stub) != SM.end()) {
Function *F = SM[Stub];
SM.erase(Stub);
FM.erase(F);
return F;
}
for (std::map<GlobalValue*,void*>::iterator i = GM.begin(), e = GM.end();
i != e; ++i) {
if (i->second != Stub)
continue;
GlobalValue *GV = i->first;
GM.erase(i);
return GV;
}
for (std::map<void *, void *>::iterator i = ExternalFnToStubMap.begin(),
e = ExternalFnToStubMap.end(); i != e; ++i) {
if (i->second != Stub)
continue;
ExternalFnToStubMap.erase(i);
break;
}
return 0;
}
void *JITResolver::JITCompilerFn(void *Stub) {
JITResolver &JR = *TheJITResolver;
Function* F = 0;
void* ActualPtr = 0;
{
MutexGuard locked(TheJIT->lock);
std::map<void*, AssertingVH<Function> >::iterator I =
JR.state.getStubToFunctionMap(locked).upper_bound(Stub);
assert(I != JR.state.getStubToFunctionMap(locked).begin() &&
"This is not a known stub!");
F = (--I)->second;
ActualPtr = I->first;
}
void *Result = TheJIT->getPointerToGlobalIfAvailable(F);
if (!Result) {
if (TheJIT->isLazyCompilationDisabled()) {
cerr << "LLVM JIT requested to do lazy compilation of function '"
<< F->getName() << "' when lazy compiles are disabled!\n";
abort();
}
DOUT << "JIT: Lazily resolving function '" << F->getName()
<< "' In stub ptr = " << Stub << " actual ptr = "
<< ActualPtr << "\n";
Result = TheJIT->getPointerToFunction(F);
}
MutexGuard locked(TheJIT->lock);
JR.state.getFunctionToStubMap(locked).erase(F);
if(JR.revGOTMap.find(Stub) != JR.revGOTMap.end())
JR.revGOTMap[Result] = JR.revGOTMap[Stub];
return Result;
}
#ifdef __APPLE__
#define ENABLE_JIT_SYMBOL_TABLE 0
#endif
struct JitSymbolEntry {
const char *FnName; void *FnStart;
intptr_t FnSize;
};
struct JitSymbolTable {
JitSymbolTable *NextPtr;
JitSymbolEntry *Symbols;
unsigned NumSymbols;
unsigned NumAllocated;
};
#if ENABLE_JIT_SYMBOL_TABLE
JitSymbolTable *__jitSymbolTable;
#endif
static void AddFunctionToSymbolTable(const char *FnName,
void *FnStart, intptr_t FnSize) {
assert(FnName != 0 && FnStart != 0 && "Bad symbol to add");
JitSymbolTable **SymTabPtrPtr = 0;
#if !ENABLE_JIT_SYMBOL_TABLE
return;
#else
SymTabPtrPtr = &__jitSymbolTable;
#endif
if (*SymTabPtrPtr == 0) {
JitSymbolTable *New = new JitSymbolTable();
New->NextPtr = 0;
New->Symbols = 0;
New->NumSymbols = 0;
New->NumAllocated = 0;
*SymTabPtrPtr = New;
}
JitSymbolTable *SymTabPtr = *SymTabPtrPtr;
if (SymTabPtr->NumSymbols >= SymTabPtr->NumAllocated) {
unsigned NewSize = std::max(64U, SymTabPtr->NumAllocated*2);
JitSymbolEntry *NewSymbols = new JitSymbolEntry[NewSize];
JitSymbolEntry *OldSymbols = SymTabPtr->Symbols;
memcpy(NewSymbols, OldSymbols, SymTabPtr->NumSymbols*sizeof(OldSymbols[0]));
SymTabPtr->Symbols = NewSymbols;
SymTabPtr->NumAllocated = NewSize;
delete [] OldSymbols;
}
JitSymbolEntry &Entry = SymTabPtr->Symbols[SymTabPtr->NumSymbols];
Entry.FnName = strdup(FnName);
Entry.FnStart = FnStart;
Entry.FnSize = FnSize;
++SymTabPtr->NumSymbols;
}
static void RemoveFunctionFromSymbolTable(void *FnStart) {
assert(FnStart && "Invalid function pointer");
JitSymbolTable **SymTabPtrPtr = 0;
#if !ENABLE_JIT_SYMBOL_TABLE
return;
#else
SymTabPtrPtr = &__jitSymbolTable;
#endif
JitSymbolTable *SymTabPtr = *SymTabPtrPtr;
JitSymbolEntry *Symbols = SymTabPtr->Symbols;
unsigned Index;
for (Index = 0; Symbols[Index].FnStart != FnStart; ++Index)
assert(Index != SymTabPtr->NumSymbols && "Didn't find function!");
const char *OldName = Symbols[Index].FnName;
Symbols[Index] = Symbols[SymTabPtr->NumSymbols-1];
free((void*)OldName);
--SymTabPtr->NumSymbols;
if (SymTabPtr->NumSymbols != 0)
return;
*SymTabPtrPtr = 0;
delete [] Symbols;
delete SymTabPtr;
}
namespace {
class JITEmitter : public MachineCodeEmitter {
JITMemoryManager *MemMgr;
unsigned char *SavedBufferBegin, *SavedBufferEnd, *SavedCurBufferPtr;
std::vector<MachineRelocation> Relocations;
std::vector<uintptr_t> MBBLocations;
MachineConstantPool *ConstantPool;
void *ConstantPoolBase;
SmallVector<uintptr_t, 8> ConstPoolAddresses;
MachineJumpTableInfo *JumpTable;
void *JumpTableBase;
JITResolver Resolver;
JITDwarfEmitter *DE;
std::vector<uintptr_t> LabelLocations;
MachineModuleInfo* MMI;
SmallPtrSet<const GlobalVariable*, 8> GVSet;
const Function *CurFn;
DenseMap<const Function *, SmallVector<void*, 1> > CurFnStubUses;
DenseMap<void *, SmallPtrSet<const Function*, 1> > StubFnRefs;
StringMap<void *> ExtFnStubs;
public:
JITEmitter(JIT &jit, JITMemoryManager *JMM) : Resolver(jit), CurFn(0) {
MemMgr = JMM ? JMM : JITMemoryManager::CreateDefaultMemManager();
if (jit.getJITInfo().needsGOT()) {
MemMgr->AllocateGOT();
DOUT << "JIT is managing a GOT\n";
}
if (ExceptionHandling) DE = new JITDwarfEmitter(jit);
}
~JITEmitter() {
delete MemMgr;
if (ExceptionHandling) delete DE;
}
static inline bool classof(const JITEmitter*) { return true; }
static inline bool classof(const MachineCodeEmitter*) { return true; }
JITResolver &getJITResolver() { return Resolver; }
virtual void startFunction(MachineFunction &F);
virtual bool finishFunction(MachineFunction &F);
void emitConstantPool(MachineConstantPool *MCP);
void initJumpTableInfo(MachineJumpTableInfo *MJTI);
void emitJumpTableInfo(MachineJumpTableInfo *MJTI);
virtual void startGVStub(const GlobalValue* GV, unsigned StubSize,
unsigned Alignment = 1);
virtual void startGVStub(const GlobalValue* GV, void *Buffer,
unsigned StubSize);
virtual void* finishGVStub(const GlobalValue *GV);
virtual void *allocateSpace(uintptr_t Size, unsigned Alignment);
virtual void addRelocation(const MachineRelocation &MR) {
Relocations.push_back(MR);
}
virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) {
if (MBBLocations.size() <= (unsigned)MBB->getNumber())
MBBLocations.resize((MBB->getNumber()+1)*2);
MBBLocations[MBB->getNumber()] = getCurrentPCValue();
DOUT << "JIT: Emitting BB" << MBB->getNumber() << " at ["
<< (void*) getCurrentPCValue() << "]\n";
}
virtual uintptr_t getConstantPoolEntryAddress(unsigned Entry) const;
virtual uintptr_t getJumpTableEntryAddress(unsigned Entry) const;
virtual uintptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const {
assert(MBBLocations.size() > (unsigned)MBB->getNumber() &&
MBBLocations[MBB->getNumber()] && "MBB not emitted!");
return MBBLocations[MBB->getNumber()];
}
void deallocateMemForFunction(Function *F);
void AddStubToCurrentFunction(void *Stub);
const StringMap<void*> &getExternalFnStubs() const { return ExtFnStubs; }
virtual void emitLabel(uint64_t LabelID) {
if (LabelLocations.size() <= LabelID)
LabelLocations.resize((LabelID+1)*2);
LabelLocations[LabelID] = getCurrentPCValue();
}
virtual uintptr_t getLabelAddress(uint64_t LabelID) const {
assert(LabelLocations.size() > (unsigned)LabelID &&
LabelLocations[LabelID] && "Label not emitted!");
return LabelLocations[LabelID];
}
virtual void setModuleInfo(MachineModuleInfo* Info) {
MMI = Info;
if (ExceptionHandling) DE->setModuleInfo(Info);
}
void setMemoryExecutable(void) {
MemMgr->setMemoryExecutable();
}
JITMemoryManager *getMemMgr(void) const { return MemMgr; }
private:
void *getPointerToGlobal(GlobalValue *GV, void *Reference, bool NoNeedStub);
void *getPointerToGVIndirectSym(GlobalValue *V, void *Reference,
bool NoNeedStub);
unsigned addSizeOfGlobal(const GlobalVariable *GV, unsigned Size);
unsigned addSizeOfGlobalsInConstantVal(const Constant *C, unsigned Size);
unsigned addSizeOfGlobalsInInitializer(const Constant *Init, unsigned Size);
unsigned GetSizeOfGlobalsInBytes(MachineFunction &MF);
};
}
void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference,
bool DoesntNeedStub) {
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
return TheJIT->getOrEmitGlobalVariable(GV);
if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V))
return TheJIT->getPointerToGlobal(GA->resolveAliasedGlobal(false));
Function *F = cast<Function>(V);
void *ResultPtr;
if (!DoesntNeedStub && !TheJIT->isLazyCompilationDisabled()) {
ResultPtr = Resolver.getFunctionStubIfAvailable(F);
if (ResultPtr)
AddStubToCurrentFunction(ResultPtr);
} else {
ResultPtr = TheJIT->getPointerToGlobalIfAvailable(F);
}
if (ResultPtr) return ResultPtr;
if (F->isDeclaration() && !F->hasNotBeenReadFromBitcode() &&
DoesntNeedStub && !TheJIT->areDlsymStubsEnabled())
return TheJIT->getPointerToFunction(F);
if (DoesntNeedStub && !TheJIT->isLazyCompilationDisabled())
return Resolver.AddCallbackAtLocation(F, Reference);
void *StubAddr = Resolver.getFunctionStub(F);
if (StubAddr)
AddStubToCurrentFunction(StubAddr);
return StubAddr;
}
void *JITEmitter::getPointerToGVIndirectSym(GlobalValue *V, void *Reference,
bool NoNeedStub) {
void *GVAddress = getPointerToGlobal(V, Reference, true);
void *StubAddr = Resolver.getGlobalValueIndirectSym(V, GVAddress);
AddStubToCurrentFunction(StubAddr);
return StubAddr;
}
void JITEmitter::AddStubToCurrentFunction(void *StubAddr) {
if (!TheJIT->areDlsymStubsEnabled())
return;
assert(CurFn && "Stub added to current function, but current function is 0!");
SmallVectorImpl<void*> &StubsUsed = CurFnStubUses[CurFn];
StubsUsed.push_back(StubAddr);
SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[StubAddr];
FnRefs.insert(CurFn);
}
static unsigned GetConstantPoolSizeInBytes(MachineConstantPool *MCP,
const TargetData *TD) {
const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
if (Constants.empty()) return 0;
unsigned Size = 0;
for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
MachineConstantPoolEntry CPE = Constants[i];
unsigned AlignMask = CPE.getAlignment() - 1;
Size = (Size + AlignMask) & ~AlignMask;
const Type *Ty = CPE.getType();
Size += TD->getTypePaddedSize(Ty);
}
return Size;
}
static unsigned GetJumpTableSizeInBytes(MachineJumpTableInfo *MJTI) {
const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
if (JT.empty()) return 0;
unsigned NumEntries = 0;
for (unsigned i = 0, e = JT.size(); i != e; ++i)
NumEntries += JT[i].MBBs.size();
unsigned EntrySize = MJTI->getEntrySize();
return NumEntries * EntrySize;
}
static uintptr_t RoundUpToAlign(uintptr_t Size, unsigned Alignment) {
if (Alignment == 0) Alignment = 1;
return Size + Alignment;
}
unsigned JITEmitter::addSizeOfGlobal(const GlobalVariable *GV, unsigned Size) {
const Type *ElTy = GV->getType()->getElementType();
size_t GVSize = (size_t)TheJIT->getTargetData()->getTypePaddedSize(ElTy);
size_t GVAlign =
(size_t)TheJIT->getTargetData()->getPreferredAlignment(GV);
DOUT << "JIT: Adding in size " << GVSize << " alignment " << GVAlign;
DEBUG(GV->dump());
if (Size==0)
Size = 1;
Size = ((Size+GVAlign-1)/GVAlign)*GVAlign;
Size += GVSize;
return Size;
}
unsigned JITEmitter::addSizeOfGlobalsInConstantVal(const Constant *C,
unsigned Size) {
if (isa<UndefValue>(C))
return Size;
if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
Constant *Op0 = CE->getOperand(0);
switch (CE->getOpcode()) {
case Instruction::GetElementPtr:
case Instruction::Trunc:
case Instruction::ZExt:
case Instruction::SExt:
case Instruction::FPTrunc:
case Instruction::FPExt:
case Instruction::UIToFP:
case Instruction::SIToFP:
case Instruction::FPToUI:
case Instruction::FPToSI:
case Instruction::PtrToInt:
case Instruction::IntToPtr:
case Instruction::BitCast: {
Size = addSizeOfGlobalsInConstantVal(Op0, Size);
break;
}
case Instruction::Add:
case Instruction::Sub:
case Instruction::Mul:
case Instruction::UDiv:
case Instruction::SDiv:
case Instruction::URem:
case Instruction::SRem:
case Instruction::And:
case Instruction::Or:
case Instruction::Xor: {
Size = addSizeOfGlobalsInConstantVal(Op0, Size);
Size = addSizeOfGlobalsInConstantVal(CE->getOperand(1), Size);
break;
}
default: {
cerr << "ConstantExpr not handled: " << *CE << "\n";
abort();
}
}
}
if (C->getType()->getTypeID() == Type::PointerTyID)
if (const GlobalVariable* GV = dyn_cast<GlobalVariable>(C))
if (GVSet.insert(GV))
Size = addSizeOfGlobal(GV, Size);
return Size;
}
unsigned JITEmitter::addSizeOfGlobalsInInitializer(const Constant *Init,
unsigned Size) {
if (!isa<UndefValue>(Init) &&
!isa<ConstantVector>(Init) &&
!isa<ConstantAggregateZero>(Init) &&
!isa<ConstantArray>(Init) &&
!isa<ConstantStruct>(Init) &&
Init->getType()->isFirstClassType())
Size = addSizeOfGlobalsInConstantVal(Init, Size);
return Size;
}
unsigned JITEmitter::GetSizeOfGlobalsInBytes(MachineFunction &MF) {
unsigned Size = 0;
GVSet.clear();
for (MachineFunction::iterator MBB = MF.begin(), E = MF.end();
MBB != E; ++MBB) {
for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
I != E; ++I) {
const TargetInstrDesc &Desc = I->getDesc();
const MachineInstr &MI = *I;
unsigned NumOps = Desc.getNumOperands();
for (unsigned CurOp = 0; CurOp < NumOps; CurOp++) {
const MachineOperand &MO = MI.getOperand(CurOp);
if (MO.isGlobal()) {
GlobalValue* V = MO.getGlobal();
const GlobalVariable *GV = dyn_cast<const GlobalVariable>(V);
if (!GV)
continue;
if (TheJIT->getPointerToGlobalIfAvailable(GV))
continue;
if (GVSet.insert(GV))
Size = addSizeOfGlobal(GV, Size);
}
}
}
}
DOUT << "JIT: About to look through initializers\n";
for (SmallPtrSet<const GlobalVariable *, 8>::iterator I = GVSet.begin();
I != GVSet.end(); I++) {
const GlobalVariable* GV = *I;
if (GV->hasInitializer())
Size = addSizeOfGlobalsInInitializer(GV->getInitializer(), Size);
}
return Size;
}
void JITEmitter::startFunction(MachineFunction &F) {
DOUT << "JIT: Starting CodeGen of Function "
<< F.getFunction()->getName() << "\n";
uintptr_t ActualSize = 0;
MemMgr->setMemoryWritable();
if (MemMgr->NeedsExactSize()) {
DOUT << "JIT: ExactSize\n";
const TargetInstrInfo* TII = F.getTarget().getInstrInfo();
MachineJumpTableInfo *MJTI = F.getJumpTableInfo();
MachineConstantPool *MCP = F.getConstantPool();
ActualSize = RoundUpToAlign(ActualSize, 16);
ActualSize = RoundUpToAlign(ActualSize, MCP->getConstantPoolAlignment());
ActualSize += GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
ActualSize = RoundUpToAlign(ActualSize, MJTI->getAlignment());
ActualSize += GetJumpTableSizeInBytes(MJTI);
ActualSize = RoundUpToAlign(ActualSize,
std::max(F.getFunction()->getAlignment(), 8U));
ActualSize += TII->GetFunctionSizeInBytes(F);
DOUT << "JIT: ActualSize before globals " << ActualSize << "\n";
ActualSize += GetSizeOfGlobalsInBytes(F);
DOUT << "JIT: ActualSize after globals " << ActualSize << "\n";
}
BufferBegin = CurBufferPtr = MemMgr->startFunctionBody(F.getFunction(),
ActualSize);
BufferEnd = BufferBegin+ActualSize;
emitAlignment(16);
emitConstantPool(F.getConstantPool());
initJumpTableInfo(F.getJumpTableInfo());
emitAlignment(std::max(F.getFunction()->getAlignment(), 8U));
TheJIT->updateGlobalMapping(F.getFunction(), CurBufferPtr);
MBBLocations.clear();
}
bool JITEmitter::finishFunction(MachineFunction &F) {
if (CurBufferPtr == BufferEnd) {
cerr << "JIT: Ran out of space for generated machine code!\n";
abort();
}
emitJumpTableInfo(F.getJumpTableInfo());
unsigned char *FnStart =
(unsigned char *)TheJIT->getPointerToGlobalIfAvailable(F.getFunction());
if (!Relocations.empty()) {
CurFn = F.getFunction();
NumRelos += Relocations.size();
for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
MachineRelocation &MR = Relocations[i];
void *ResultPtr = 0;
if (!MR.letTargetResolve()) {
if (MR.isExternalSymbol()) {
ResultPtr = TheJIT->getPointerToNamedFunction(MR.getExternalSymbol(),
false);
DOUT << "JIT: Map \'" << MR.getExternalSymbol() << "\' to ["
<< ResultPtr << "]\n";
if (!MR.doesntNeedStub()) {
if (!TheJIT->areDlsymStubsEnabled()) {
ResultPtr = Resolver.getExternalFunctionStub(ResultPtr);
} else {
void *&Stub = ExtFnStubs[MR.getExternalSymbol()];
if (!Stub) {
Stub = Resolver.getExternalFunctionStub((void *)&Stub);
AddStubToCurrentFunction(Stub);
}
ResultPtr = Stub;
}
}
} else if (MR.isGlobalValue()) {
ResultPtr = getPointerToGlobal(MR.getGlobalValue(),
BufferBegin+MR.getMachineCodeOffset(),
MR.doesntNeedStub());
} else if (MR.isIndirectSymbol()) {
ResultPtr = getPointerToGVIndirectSym(MR.getGlobalValue(),
BufferBegin+MR.getMachineCodeOffset(),
MR.doesntNeedStub());
} else if (MR.isBasicBlock()) {
ResultPtr = (void*)getMachineBasicBlockAddress(MR.getBasicBlock());
} else if (MR.isConstantPoolIndex()) {
ResultPtr = (void*)getConstantPoolEntryAddress(MR.getConstantPoolIndex());
} else {
assert(MR.isJumpTableIndex());
ResultPtr=(void*)getJumpTableEntryAddress(MR.getJumpTableIndex());
}
MR.setResultPointer(ResultPtr);
}
if (MR.isGOTRelative() && MemMgr->isManagingGOT()) {
unsigned idx = Resolver.getGOTIndexForAddr(ResultPtr);
MR.setGOTIndex(idx);
if (((void**)MemMgr->getGOTBase())[idx] != ResultPtr) {
DOUT << "JIT: GOT was out of date for " << ResultPtr
<< " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
<< "\n";
((void**)MemMgr->getGOTBase())[idx] = ResultPtr;
}
}
}
CurFn = 0;
TheJIT->getJITInfo().relocate(BufferBegin, &Relocations[0],
Relocations.size(), MemMgr->getGOTBase());
}
if (MemMgr->isManagingGOT()) {
unsigned idx = Resolver.getGOTIndexForAddr((void*)BufferBegin);
if (((void**)MemMgr->getGOTBase())[idx] != (void*)BufferBegin) {
DOUT << "JIT: GOT was out of date for " << (void*)BufferBegin
<< " pointing at " << ((void**)MemMgr->getGOTBase())[idx] << "\n";
((void**)MemMgr->getGOTBase())[idx] = (void*)BufferBegin;
}
}
unsigned char *FnEnd = CurBufferPtr;
MemMgr->endFunctionBody(F.getFunction(), BufferBegin, FnEnd);
if (CurBufferPtr == BufferEnd) {
cerr << "JIT: Ran out of space for generated machine code!\n";
abort();
}
BufferBegin = CurBufferPtr = 0;
NumBytes += FnEnd-FnStart;
sys::Memory::InvalidateInstructionCache(FnStart, FnEnd-FnStart);
AddFunctionToSymbolTable(F.getFunction()->getNameStart(),
FnStart, FnEnd-FnStart);
DOUT << "JIT: Finished CodeGen of [" << (void*)FnStart
<< "] Function: " << F.getFunction()->getName()
<< ": " << (FnEnd-FnStart) << " bytes of text, "
<< Relocations.size() << " relocations\n";
Relocations.clear();
ConstPoolAddresses.clear();
MemMgr->setMemoryExecutable();
#ifndef NDEBUG
{
if (sys::hasDisassembler()) {
DOUT << "JIT: Disassembled code:\n";
DOUT << sys::disassembleBuffer(FnStart, FnEnd-FnStart, (uintptr_t)FnStart);
} else {
DOUT << "JIT: Binary code:\n";
DOUT << std::hex;
unsigned char* q = FnStart;
for (int i = 0; q < FnEnd; q += 4, ++i) {
if (i == 4)
i = 0;
if (i == 0)
DOUT << "JIT: " << std::setw(8) << std::setfill('0')
<< (long)(q - FnStart) << ": ";
bool Done = false;
for (int j = 3; j >= 0; --j) {
if (q + j >= FnEnd)
Done = true;
else
DOUT << std::setw(2) << std::setfill('0') << (unsigned short)q[j];
}
if (Done)
break;
DOUT << ' ';
if (i == 3)
DOUT << '\n';
}
DOUT << std::dec;
DOUT<< '\n';
}
}
#endif
if (ExceptionHandling) {
uintptr_t ActualSize = 0;
SavedBufferBegin = BufferBegin;
SavedBufferEnd = BufferEnd;
SavedCurBufferPtr = CurBufferPtr;
if (MemMgr->NeedsExactSize()) {
ActualSize = DE->GetDwarfTableSizeInBytes(F, *this, FnStart, FnEnd);
}
BufferBegin = CurBufferPtr = MemMgr->startExceptionTable(F.getFunction(),
ActualSize);
BufferEnd = BufferBegin+ActualSize;
unsigned char* FrameRegister = DE->EmitDwarfTable(F, *this, FnStart, FnEnd);
MemMgr->endExceptionTable(F.getFunction(), BufferBegin, CurBufferPtr,
FrameRegister);
BufferBegin = SavedBufferBegin;
BufferEnd = SavedBufferEnd;
CurBufferPtr = SavedCurBufferPtr;
TheJIT->RegisterTable(FrameRegister);
}
if (MMI)
MMI->EndFunction();
return false;
}
void JITEmitter::deallocateMemForFunction(Function *F) {
MemMgr->deallocateMemForFunction(F);
if (CurFnStubUses.find(F) == CurFnStubUses.end())
return;
SmallVectorImpl<void *> &StubList = CurFnStubUses[F];
for (unsigned i = 0, e = StubList.size(); i != e; ++i) {
void *Stub = StubList[i];
if (StubFnRefs.count(Stub) == 0)
continue;
SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[Stub];
FnRefs.erase(F);
if (FnRefs.empty()) {
DOUT << "\nJIT: Invalidated Stub at [" << Stub << "]\n";
StubFnRefs.erase(Stub);
GlobalValue *GV = Resolver.invalidateStub(Stub);
if (GV) {
TheJIT->updateGlobalMapping(GV, 0);
} else {
for (StringMapIterator<void*> i = ExtFnStubs.begin(),
e = ExtFnStubs.end(); i != e; ++i) {
if (i->second == Stub) {
ExtFnStubs.erase(i);
break;
}
}
}
}
}
CurFnStubUses.erase(F);
}
void* JITEmitter::allocateSpace(uintptr_t Size, unsigned Alignment) {
if (BufferBegin)
return MachineCodeEmitter::allocateSpace(Size, Alignment);
BufferBegin = CurBufferPtr = MemMgr->allocateSpace(Size, Alignment);
BufferEnd = BufferBegin+Size;
return CurBufferPtr;
}
void JITEmitter::emitConstantPool(MachineConstantPool *MCP) {
if (TheJIT->getJITInfo().hasCustomConstantPool())
return;
const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
if (Constants.empty()) return;
unsigned Size = GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
unsigned Align = MCP->getConstantPoolAlignment();
ConstantPoolBase = allocateSpace(Size, Align);
ConstantPool = MCP;
if (ConstantPoolBase == 0) return;
DOUT << "JIT: Emitted constant pool at [" << ConstantPoolBase
<< "] (size: " << Size << ", alignment: " << Align << ")\n";
unsigned Offset = 0;
for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
MachineConstantPoolEntry CPE = Constants[i];
unsigned AlignMask = CPE.getAlignment() - 1;
Offset = (Offset + AlignMask) & ~AlignMask;
uintptr_t CAddr = (uintptr_t)ConstantPoolBase + Offset;
ConstPoolAddresses.push_back(CAddr);
if (CPE.isMachineConstantPoolEntry()) {
cerr << "Initialize memory with machine specific constant pool entry"
<< " has not been implemented!\n";
abort();
}
TheJIT->InitializeMemory(CPE.Val.ConstVal, (void*)CAddr);
DOUT << "JIT: CP" << i << " at [0x"
<< std::hex << CAddr << std::dec << "]\n";
const Type *Ty = CPE.Val.ConstVal->getType();
Offset += TheJIT->getTargetData()->getTypePaddedSize(Ty);
}
}
void JITEmitter::initJumpTableInfo(MachineJumpTableInfo *MJTI) {
if (TheJIT->getJITInfo().hasCustomJumpTables())
return;
const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
if (JT.empty()) return;
unsigned NumEntries = 0;
for (unsigned i = 0, e = JT.size(); i != e; ++i)
NumEntries += JT[i].MBBs.size();
unsigned EntrySize = MJTI->getEntrySize();
JumpTable = MJTI;
JumpTableBase = allocateSpace(NumEntries * EntrySize, MJTI->getAlignment());
}
void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) {
if (TheJIT->getJITInfo().hasCustomJumpTables())
return;
const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
if (JT.empty() || JumpTableBase == 0) return;
if (TargetMachine::getRelocationModel() == Reloc::PIC_) {
assert(MJTI->getEntrySize() == 4 && "Cross JIT'ing?");
int *SlotPtr = (int*)JumpTableBase;
for (unsigned i = 0, e = JT.size(); i != e; ++i) {
const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
uintptr_t Base = (uintptr_t)SlotPtr;
for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi) {
uintptr_t MBBAddr = getMachineBasicBlockAddress(MBBs[mi]);
*SlotPtr++ = TheJIT->getJITInfo().getPICJumpTableEntry(MBBAddr, Base);
}
}
} else {
assert(MJTI->getEntrySize() == sizeof(void*) && "Cross JIT'ing?");
intptr_t *SlotPtr = (intptr_t*)JumpTableBase;
for (unsigned i = 0, e = JT.size(); i != e; ++i) {
const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi)
*SlotPtr++ = getMachineBasicBlockAddress(MBBs[mi]);
}
}
}
void JITEmitter::startGVStub(const GlobalValue* GV, unsigned StubSize,
unsigned Alignment) {
SavedBufferBegin = BufferBegin;
SavedBufferEnd = BufferEnd;
SavedCurBufferPtr = CurBufferPtr;
BufferBegin = CurBufferPtr = MemMgr->allocateStub(GV, StubSize, Alignment);
BufferEnd = BufferBegin+StubSize+1;
}
void JITEmitter::startGVStub(const GlobalValue* GV, void *Buffer,
unsigned StubSize) {
SavedBufferBegin = BufferBegin;
SavedBufferEnd = BufferEnd;
SavedCurBufferPtr = CurBufferPtr;
BufferBegin = CurBufferPtr = (unsigned char *)Buffer;
BufferEnd = BufferBegin+StubSize+1;
}
void *JITEmitter::finishGVStub(const GlobalValue* GV) {
NumBytes += getCurrentPCOffset();
std::swap(SavedBufferBegin, BufferBegin);
BufferEnd = SavedBufferEnd;
CurBufferPtr = SavedCurBufferPtr;
return SavedBufferBegin;
}
uintptr_t JITEmitter::getConstantPoolEntryAddress(unsigned ConstantNum) const {
assert(ConstantNum < ConstantPool->getConstants().size() &&
"Invalid ConstantPoolIndex!");
return ConstPoolAddresses[ConstantNum];
}
uintptr_t JITEmitter::getJumpTableEntryAddress(unsigned Index) const {
const std::vector<MachineJumpTableEntry> &JT = JumpTable->getJumpTables();
assert(Index < JT.size() && "Invalid jump table index!");
unsigned Offset = 0;
unsigned EntrySize = JumpTable->getEntrySize();
for (unsigned i = 0; i < Index; ++i)
Offset += JT[i].MBBs.size();
Offset *= EntrySize;
return (uintptr_t)((char *)JumpTableBase + Offset);
}
MachineCodeEmitter *JIT::createEmitter(JIT &jit, JITMemoryManager *JMM) {
return new JITEmitter(jit, JMM);
}
extern "C" {
void *getPointerToNamedFunction(const char *Name) {
if (Function *F = TheJIT->FindFunctionNamed(Name))
return TheJIT->getPointerToFunction(F);
return TheJIT->getPointerToNamedFunction(Name);
}
}
void *JIT::getPointerToFunctionOrStub(Function *F) {
if (void *Addr = getPointerToGlobalIfAvailable(F))
return Addr;
assert(isa<JITEmitter>(MCE) && "Unexpected MCE?");
JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
return JE->getJITResolver().getFunctionStub(F);
}
void JIT::updateFunctionStub(Function *F) {
assert(isa<JITEmitter>(MCE) && "Unexpected MCE?");
JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
void *Stub = JE->getJITResolver().getFunctionStub(F);
void *Addr = getPointerToGlobalIfAvailable(F);
getJITInfo().emitFunctionStubAtAddr(F, Addr, Stub, *getCodeEmitter());
}
void JIT::updateDlsymStubTable() {
assert(isa<JITEmitter>(MCE) && "Unexpected MCE?");
JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
SmallVector<GlobalValue*, 8> GVs;
SmallVector<void*, 8> Ptrs;
const StringMap<void *> &ExtFns = JE->getExternalFnStubs();
JE->getJITResolver().getRelocatableGVs(GVs, Ptrs);
unsigned nStubs = GVs.size() + ExtFns.size();
if (nStubs == 0)
return;
void *CurTable = JE->getMemMgr()->getDlsymTable();
if (CurTable && (*(unsigned *)CurTable == nStubs))
return;
unsigned offset = 4 + 4 * nStubs + sizeof(intptr_t) * nStubs;
SmallVector<unsigned, 8> Offsets;
for (unsigned i = 0; i != GVs.size(); ++i) {
Offsets.push_back(offset);
offset += GVs[i]->getName().length() + 1;
}
for (StringMapConstIterator<void*> i = ExtFns.begin(), e = ExtFns.end();
i != e; ++i) {
Offsets.push_back(offset);
offset += strlen(i->first()) + 1;
}
JE->startGVStub(0, offset, 4);
MCE->emitInt32(nStubs);
for (unsigned i = 0; i != nStubs; ++i)
MCE->emitInt32(Offsets[i]);
for (unsigned i = 0; i != GVs.size(); ++i) {
intptr_t Ptr = (intptr_t)Ptrs[i];
assert((Ptr & 1) == 0 && "Stub pointers must be at least 2-byte aligned!");
if (isa<Function>(GVs[i]))
Ptr |= (intptr_t)1;
if (sizeof(Ptr) == 8)
MCE->emitInt64(Ptr);
else
MCE->emitInt32(Ptr);
}
for (StringMapConstIterator<void*> i = ExtFns.begin(), e = ExtFns.end();
i != e; ++i) {
intptr_t Ptr = (intptr_t)i->second | 1;
if (sizeof(Ptr) == 8)
MCE->emitInt64(Ptr);
else
MCE->emitInt32(Ptr);
}
for (unsigned i = 0; i != GVs.size(); ++i)
MCE->emitString(GVs[i]->getName());
for (StringMapConstIterator<void*> i = ExtFns.begin(), e = ExtFns.end();
i != e; ++i)
MCE->emitString(i->first());
JE->getMemMgr()->SetDlsymTable(JE->finishGVStub(0));
}
void JIT::freeMachineCodeForFunction(Function *F) {
void *OldPtr = updateGlobalMapping(F, 0);
if (OldPtr)
RemoveFunctionFromSymbolTable(OldPtr);
assert(isa<JITEmitter>(MCE) && "Unexpected MCE?");
cast<JITEmitter>(MCE)->deallocateMemForFunction(F);
}