// doInitialization - Initializes the vector of functions that have not
// been annotated with the "always inline" attribute.
bool AlwaysInliner::doInitialization(CallGraph &CG) {
Module &M = CG.getModule();
for (Module::iterator I = M.begin(), E = M.end();
I != E; ++I)
if (!I->isDeclaration() && !I->hasFnAttr(Attribute::AlwaysInline))
NeverInline.insert(I);
return false;
}
/// Finalize CG
bool CGPassManager::doFinalization(CallGraph &CG) {
bool Changed = false;
for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
Pass *P = getContainedPass(Index);
if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P)) {
Changed |= CGSP->doFinalization(CG);
} else {
FPPassManager *FP = dynamic_cast<FPPassManager *>(P);
assert (FP && "Invalid CGPassManager member");
Changed |= FP->doFinalization(CG.getModule());
}
}
return Changed;
}
// doInitialization - Initializes the vector of functions that have been
// annotated with the noinline attribute.
bool SimpleInliner::doInitialization(CallGraph &CG) {
CA.setTargetData(getAnalysisIfAvailable<TargetData>());
Module &M = CG.getModule();
for (Module::iterator I = M.begin(), E = M.end();
I != E; ++I)
if (!I->isDeclaration() && I->hasFnAttr(Attribute::NoInline))
NeverInline.insert(I);
// Get llvm.noinline
GlobalVariable *GV = M.getNamedGlobal("llvm.noinline");
if (GV == 0)
return false;
// Don't crash on invalid code
if (!GV->hasDefinitiveInitializer())
return false;
const ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
if (InitList == 0)
return false;
// Iterate over each element and add to the NeverInline set
for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
// Get Source
const Constant *Elt = InitList->getOperand(i);
if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(Elt))
if (CE->getOpcode() == Instruction::BitCast)
Elt = CE->getOperand(0);
// Insert into set of functions to never inline
if (const Function *F = dyn_cast<Function>(Elt))
NeverInline.insert(F);
}
return false;
}
// Make sure that there is a devirtualization trigger function that CoroSplit
// pass uses the force restart CGSCC pipeline. If devirt trigger function is not
// found, we will create one and add it to the current SCC.
static void createDevirtTriggerFunc(CallGraph &CG, CallGraphSCC &SCC) {
Module &M = CG.getModule();
if (M.getFunction(CORO_DEVIRT_TRIGGER_FN))
return;
LLVMContext &C = M.getContext();
auto *FnTy = FunctionType::get(Type::getVoidTy(C), Type::getInt8PtrTy(C),
/*IsVarArgs=*/false);
Function *DevirtFn =
Function::Create(FnTy, GlobalValue::LinkageTypes::PrivateLinkage,
CORO_DEVIRT_TRIGGER_FN, &M);
DevirtFn->addFnAttr(Attribute::AlwaysInline);
auto *Entry = BasicBlock::Create(C, "entry", DevirtFn);
ReturnInst::Create(C, Entry);
auto *Node = CG.getOrInsertFunction(DevirtFn);
SmallVector<CallGraphNode *, 8> Nodes(SCC.begin(), SCC.end());
Nodes.push_back(Node);
SCC.initialize(Nodes);
}
/// Remove dead functions that are not included in DNR (Do Not Remove) list.
bool Inliner::removeDeadFunctions(CallGraph &CG, bool AlwaysInlineOnly) {
SmallVector<CallGraphNode*, 16> FunctionsToRemove;
SmallVector<CallGraphNode *, 16> DeadFunctionsInComdats;
SmallDenseMap<const Comdat *, int, 16> ComdatEntriesAlive;
auto RemoveCGN = [&](CallGraphNode *CGN) {
// Remove any call graph edges from the function to its callees.
CGN->removeAllCalledFunctions();
// Remove any edges from the external node to the function's call graph
// node. These edges might have been made irrelegant due to
// optimization of the program.
CG.getExternalCallingNode()->removeAnyCallEdgeTo(CGN);
// Removing the node for callee from the call graph and delete it.
FunctionsToRemove.push_back(CGN);
};
// Scan for all of the functions, looking for ones that should now be removed
// from the program. Insert the dead ones in the FunctionsToRemove set.
for (CallGraph::iterator I = CG.begin(), E = CG.end(); I != E; ++I) {
CallGraphNode *CGN = I->second;
Function *F = CGN->getFunction();
if (!F || F->isDeclaration())
continue;
// Handle the case when this function is called and we only want to care
// about always-inline functions. This is a bit of a hack to share code
// between here and the InlineAlways pass.
if (AlwaysInlineOnly && !F->hasFnAttribute(Attribute::AlwaysInline))
continue;
// If the only remaining users of the function are dead constants, remove
// them.
F->removeDeadConstantUsers();
if (!F->isDefTriviallyDead())
continue;
// It is unsafe to drop a function with discardable linkage from a COMDAT
// without also dropping the other members of the COMDAT.
// The inliner doesn't visit non-function entities which are in COMDAT
// groups so it is unsafe to do so *unless* the linkage is local.
if (!F->hasLocalLinkage()) {
if (const Comdat *C = F->getComdat()) {
--ComdatEntriesAlive[C];
DeadFunctionsInComdats.push_back(CGN);
continue;
}
}
RemoveCGN(CGN);
}
if (!DeadFunctionsInComdats.empty()) {
// Count up all the entities in COMDAT groups
auto ComdatGroupReferenced = [&](const Comdat *C) {
auto I = ComdatEntriesAlive.find(C);
if (I != ComdatEntriesAlive.end())
++(I->getSecond());
};
for (const Function &F : CG.getModule())
if (const Comdat *C = F.getComdat())
ComdatGroupReferenced(C);
for (const GlobalVariable &GV : CG.getModule().globals())
if (const Comdat *C = GV.getComdat())
ComdatGroupReferenced(C);
for (const GlobalAlias &GA : CG.getModule().aliases())
if (const Comdat *C = GA.getComdat())
ComdatGroupReferenced(C);
for (CallGraphNode *CGN : DeadFunctionsInComdats) {
Function *F = CGN->getFunction();
const Comdat *C = F->getComdat();
int NumAlive = ComdatEntriesAlive[C];
// We can remove functions in a COMDAT group if the entire group is dead.
assert(NumAlive >= 0);
if (NumAlive > 0)
continue;
RemoveCGN(CGN);
}
}
if (FunctionsToRemove.empty())
return false;
// Now that we know which functions to delete, do so. We didn't want to do
// this inline, because that would invalidate our CallGraph::iterator
// objects. :(
//
// Note that it doesn't matter that we are iterating over a non-stable order
// here to do this, it doesn't matter which order the functions are deleted
// in.
array_pod_sort(FunctionsToRemove.begin(), FunctionsToRemove.end());
FunctionsToRemove.erase(std::unique(FunctionsToRemove.begin(),
FunctionsToRemove.end()),
FunctionsToRemove.end());
for (SmallVectorImpl<CallGraphNode *>::iterator I = FunctionsToRemove.begin(),
E = FunctionsToRemove.end();
I != E; ++I) {
delete CG.removeFunctionFromModule(*I);
++NumDeleted;
}
return true;
}
bool ArgPromotion::doInitialization(CallGraph &CG) {
FunctionDIs = makeSubprogramMap(CG.getModule());
return CallGraphSCCPass::doInitialization(CG);
}
bool CGPassManager::RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC,
CallGraph &CG, bool &CallGraphUpToDate,
bool &DevirtualizedCall) {
bool Changed = false;
PMDataManager *PM = P->getAsPMDataManager();
Module &M = CG.getModule();
if (!PM) {
CallGraphSCCPass *CGSP = (CallGraphSCCPass *)P;
if (!CallGraphUpToDate) {
DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false);
CallGraphUpToDate = true;
}
{
unsigned InstrCount, SCCCount = 0;
bool EmitICRemark = M.shouldEmitInstrCountChangedRemark();
TimeRegion PassTimer(getPassTimer(CGSP));
if (EmitICRemark)
InstrCount = initSizeRemarkInfo(M);
Changed = CGSP->runOnSCC(CurSCC);
if (EmitICRemark) {
// FIXME: Add getInstructionCount to CallGraphSCC.
SCCCount = M.getInstructionCount();
// Is there a difference in the number of instructions in the module?
if (SCCCount != InstrCount) {
// Yep. Emit a remark and update InstrCount.
int64_t Delta =
static_cast<int64_t>(SCCCount) - static_cast<int64_t>(InstrCount);
emitInstrCountChangedRemark(P, M, Delta, InstrCount);
InstrCount = SCCCount;
}
}
}
// After the CGSCCPass is done, when assertions are enabled, use
// RefreshCallGraph to verify that the callgraph was correctly updated.
#ifndef NDEBUG
if (Changed)
RefreshCallGraph(CurSCC, CG, true);
#endif
return Changed;
}
assert(PM->getPassManagerType() == PMT_FunctionPassManager &&
"Invalid CGPassManager member");
FPPassManager *FPP = (FPPassManager*)P;
// Run pass P on all functions in the current SCC.
for (CallGraphNode *CGN : CurSCC) {
if (Function *F = CGN->getFunction()) {
dumpPassInfo(P, EXECUTION_MSG, ON_FUNCTION_MSG, F->getName());
{
TimeRegion PassTimer(getPassTimer(FPP));
Changed |= FPP->runOnFunction(*F);
}
F->getContext().yield();
}
}
// The function pass(es) modified the IR, they may have clobbered the
// callgraph.
if (Changed && CallGraphUpToDate) {
LLVM_DEBUG(dbgs() << "CGSCCPASSMGR: Pass Dirtied SCC: " << P->getPassName()
<< '\n');
CallGraphUpToDate = false;
}
return Changed;
}
/// Remove dead functions that are not included in DNR (Do Not Remove) list.
bool LegacyInlinerBase::removeDeadFunctions(CallGraph &CG,
bool AlwaysInlineOnly) {
SmallVector<CallGraphNode *, 16> FunctionsToRemove;
SmallVector<Function *, 16> DeadFunctionsInComdats;
auto RemoveCGN = [&](CallGraphNode *CGN) {
// Remove any call graph edges from the function to its callees.
CGN->removeAllCalledFunctions();
// Remove any edges from the external node to the function's call graph
// node. These edges might have been made irrelegant due to
// optimization of the program.
CG.getExternalCallingNode()->removeAnyCallEdgeTo(CGN);
// Removing the node for callee from the call graph and delete it.
FunctionsToRemove.push_back(CGN);
};
// Scan for all of the functions, looking for ones that should now be removed
// from the program. Insert the dead ones in the FunctionsToRemove set.
for (const auto &I : CG) {
CallGraphNode *CGN = I.second.get();
Function *F = CGN->getFunction();
if (!F || F->isDeclaration())
continue;
// Handle the case when this function is called and we only want to care
// about always-inline functions. This is a bit of a hack to share code
// between here and the InlineAlways pass.
if (AlwaysInlineOnly && !F->hasFnAttribute(Attribute::AlwaysInline))
continue;
// If the only remaining users of the function are dead constants, remove
// them.
F->removeDeadConstantUsers();
if (!F->isDefTriviallyDead())
continue;
// It is unsafe to drop a function with discardable linkage from a COMDAT
// without also dropping the other members of the COMDAT.
// The inliner doesn't visit non-function entities which are in COMDAT
// groups so it is unsafe to do so *unless* the linkage is local.
if (!F->hasLocalLinkage()) {
if (F->hasComdat()) {
DeadFunctionsInComdats.push_back(F);
continue;
}
}
RemoveCGN(CGN);
}
if (!DeadFunctionsInComdats.empty()) {
// Filter out the functions whose comdats remain alive.
filterDeadComdatFunctions(CG.getModule(), DeadFunctionsInComdats);
// Remove the rest.
for (Function *F : DeadFunctionsInComdats)
RemoveCGN(CG[F]);
}
if (FunctionsToRemove.empty())
return false;
// Now that we know which functions to delete, do so. We didn't want to do
// this inline, because that would invalidate our CallGraph::iterator
// objects. :(
//
// Note that it doesn't matter that we are iterating over a non-stable order
// here to do this, it doesn't matter which order the functions are deleted
// in.
array_pod_sort(FunctionsToRemove.begin(), FunctionsToRemove.end());
FunctionsToRemove.erase(
std::unique(FunctionsToRemove.begin(), FunctionsToRemove.end()),
FunctionsToRemove.end());
for (CallGraphNode *CGN : FunctionsToRemove) {
delete CG.removeFunctionFromModule(CGN);
++NumDeleted;
}
return true;
}
bool LegacyInlinerBase::doInitialization(CallGraph &CG) {
if (InlinerFunctionImportStats != InlinerFunctionImportStatsOpts::No)
ImportedFunctionsStats.setModuleInfo(CG.getModule());
return false; // No changes to CallGraph.
}
