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Allow cross-process JIT to handle MachineRelocations of the ExternalSymbol 

variety.  For example, an i64 div might turn into a call to __divdi3 during
legalization.

llvm-svn: 66646
This commit is contained in:
Nate Begeman 2009-03-11 07:03:43 +00:00
parent ce6a26cb1a
commit 664cf27602
1 changed files with 82 additions and 13 deletions
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95
llvm/lib/ExecutionEngine/JIT/JITEmitter.cpp
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@ -309,7 +309,7 @@ GlobalValue *JITResolver::invalidateStub(void *Stub) {
return F;
}
// Otherwise, it must be an indirect symbol stub. Find it and remove it.
// Otherwise, it might be an indirect symbol stub. Find it and remove it.
for (std::map<GlobalValue*,void*>::iterator i = GM.begin(), e = GM.end();
i != e; ++i) {
if (i->second != Stub)
@ -319,6 +319,15 @@ GlobalValue *JITResolver::invalidateStub(void *Stub) {
return GV;
}
// Lastly, check to see if it's in the ExternalFnToStubMap.
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;
}
@ -591,6 +600,10 @@ namespace {
// the stub is unused.
DenseMap<void *, SmallPtrSet<const Function*, 1> > StubFnRefs;
// ExtFnStubs - A map of external function names to stubs which have entries
// in the JITResolver's ExternalFnToStubMap.
StringMap<void *> ExtFnStubs;
public:
JITEmitter(JIT &jit, JITMemoryManager *JMM) : Resolver(jit), CurFn(0) {
MemMgr = JMM ? JMM : JITMemoryManager::CreateDefaultMemManager();
@ -652,11 +665,18 @@ namespace {
return MBBLocations[MBB->getNumber()];
}
void AddStubToCurrentFunction(void *Stub);
/// deallocateMemForFunction - Deallocate all memory for the specified
/// function body.
void deallocateMemForFunction(Function *F);
/// AddStubToCurrentFunction - Mark the current function being JIT'd as
/// using the stub at the specified address. Allows
/// deallocateMemForFunction to also remove stubs no longer referenced.
void AddStubToCurrentFunction(void *Stub);
/// getExternalFnStubs - Accessor for the JIT to find stubs emitted for
/// MachineRelocations that reference external functions by name.
const StringMap<void*> &getExternalFnStubs() const { return ExtFnStubs; }
virtual void emitLabel(uint64_t LabelID) {
if (LabelLocations.size() <= LabelID)
@ -1033,8 +1053,18 @@ bool JITEmitter::finishFunction(MachineFunction &F) {
<< ResultPtr << "]\n";
// If the target REALLY wants a stub for this function, emit it now.
if (!MR.doesntNeedStub())
ResultPtr = Resolver.getExternalFunctionStub(ResultPtr);
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(),
@ -1189,6 +1219,11 @@ void JITEmitter::deallocateMemForFunction(Function *F) {
SmallVectorImpl<void *> &StubList = CurFnStubUses[F];
for (unsigned i = 0, e = StubList.size(); i != e; ++i) {
void *Stub = StubList[i];
// If we already invalidated this stub for this function, continue.
if (StubFnRefs.count(Stub) == 0)
continue;
SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[Stub];
FnRefs.erase(F);
@ -1197,9 +1232,23 @@ void JITEmitter::deallocateMemForFunction(Function *F) {
// we could call that at this point too.
if (FnRefs.empty()) {
DOUT << "\nJIT: Invalidated Stub at [" << Stub << "]\n";
StubFnRefs.erase(Stub);
// Invalidate the stub. If it is a GV stub, update the JIT's global
// mapping for that GV to zero, otherwise, search the string map of
// external function names to stubs and remove the entry for this stub.
GlobalValue *GV = Resolver.invalidateStub(Stub);
TheJIT->updateGlobalMapping(GV, 0);
StubFnRefs.erase(F);
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);
@ -1428,35 +1477,43 @@ void JIT::updateDlsymStubTable() {
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 there are no relocatable stubs, return.
if (GVs.empty())
if (nStubs == 0)
return;
// If there are no new relocatable stubs, return.
void *CurTable = JE->getMemMgr()->getDlsymTable();
if (CurTable && (*(unsigned *)CurTable == GVs.size()))
if (CurTable && (*(unsigned *)CurTable == nStubs))
return;
// Calculate the size of the stub info
unsigned offset = 4 + 4 * GVs.size() + sizeof(intptr_t) * GVs.size();
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;
}
// Allocate space for the new "stub", which contains the dlsym table.
JE->startGVStub(0, offset, 4);
// Emit the number of records
MCE->emitInt32(GVs.size());
MCE->emitInt32(nStubs);
// Emit the string offsets
for (unsigned i = 0; i != GVs.size(); ++i)
for (unsigned i = 0; i != nStubs; ++i)
MCE->emitInt32(Offsets[i]);
// Emit the pointers. Verify that they are at least 2-byte aligned, and set
@ -1470,7 +1527,16 @@ void JIT::updateDlsymStubTable() {
if (isa<Function>(GVs[i]))
Ptr |= (intptr_t)1;
if (sizeof(void *) == 8)
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);
@ -1479,6 +1545,9 @@ void JIT::updateDlsymStubTable() {
// Emit the strings.
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());
// Tell the JIT memory manager where it is. The JIT Memory Manager will
// deallocate space for the old one, if one existed.