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-rw-r--r--clang/lib/CodeGen/CGCXX.cpp12
-rw-r--r--clang/lib/CodeGen/CGClass.cpp2
-rw-r--r--clang/lib/CodeGen/CGOpenMPRuntime.cpp2
-rw-r--r--clang/lib/CodeGen/CodeGenModule.cpp105
-rw-r--r--clang/lib/CodeGen/CodeGenModule.h10
-rw-r--r--clang/lib/CodeGen/ItaniumCXXABI.cpp3
6 files changed, 123 insertions, 11 deletions
diff --git a/clang/lib/CodeGen/CGCXX.cpp b/clang/lib/CodeGen/CGCXX.cpp
index ad303649867..07eb91582af 100644
--- a/clang/lib/CodeGen/CGCXX.cpp
+++ b/clang/lib/CodeGen/CGCXX.cpp
@@ -109,6 +109,9 @@ bool CodeGenModule::TryEmitBaseDestructorAsAlias(const CXXDestructorDecl *D) {
D->getType()->getAs<FunctionType>()->getCallConv())
return true;
+ if (BaseD->hasAttr<AlwaysInlineAttr>())
+ return true;
+
return TryEmitDefinitionAsAlias(GlobalDecl(D, Dtor_Base),
GlobalDecl(BaseD, Dtor_Base),
false);
@@ -161,14 +164,7 @@ bool CodeGenModule::TryEmitDefinitionAsAlias(GlobalDecl AliasDecl,
// Instead of creating as alias to a linkonce_odr, replace all of the uses
// of the aliasee.
- if (llvm::GlobalValue::isDiscardableIfUnused(Linkage) &&
- (TargetLinkage != llvm::GlobalValue::AvailableExternallyLinkage ||
- !TargetDecl.getDecl()->hasAttr<AlwaysInlineAttr>())) {
- // FIXME: An extern template instantiation will create functions with
- // linkage "AvailableExternally". In libc++, some classes also define
- // members with attribute "AlwaysInline" and expect no reference to
- // be generated. It is desirable to reenable this optimisation after
- // corresponding LLVM changes.
+ if (llvm::GlobalValue::isDiscardableIfUnused(Linkage)) {
Replacements[MangledName] = Aliasee;
return false;
}
diff --git a/clang/lib/CodeGen/CGClass.cpp b/clang/lib/CodeGen/CGClass.cpp
index b11814f21e1..b0916ed3dcb 100644
--- a/clang/lib/CodeGen/CGClass.cpp
+++ b/clang/lib/CodeGen/CGClass.cpp
@@ -1557,7 +1557,7 @@ void CodeGenFunction::EmitDestructorBody(FunctionArgList &Args) {
// -fapple-kext must inline any call to this dtor into
// the caller's body.
if (getLangOpts().AppleKext)
- CurFn->addFnAttr(llvm::Attribute::AlwaysInline);
+ CGM.AddAlwaysInlineFunction(CurFn);
break;
}
diff --git a/clang/lib/CodeGen/CGOpenMPRuntime.cpp b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
index a9e7a9c5552..f85f66bd134 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -2114,7 +2114,7 @@ emitTaskPrivateMappingFunction(CodeGenModule &CGM, SourceLocation Loc,
".omp_task_privates_map.", &CGM.getModule());
CGM.SetLLVMFunctionAttributes(/*D=*/nullptr, TaskPrivatesMapFnInfo,
TaskPrivatesMap);
- TaskPrivatesMap->addFnAttr(llvm::Attribute::AlwaysInline);
+ CGM.AddAlwaysInlineFunction(TaskPrivatesMap);
CodeGenFunction CGF(CGM);
CGF.disableDebugInfo();
CGF.StartFunction(GlobalDecl(), C.VoidTy, TaskPrivatesMap,
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index bbc01cba633..4fe25ff3f31 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -448,6 +448,109 @@ void CodeGenModule::Release() {
EmitVersionIdentMetadata();
EmitTargetMetadata();
+
+ RewriteAlwaysInlineFunctions();
+}
+
+void CodeGenModule::AddAlwaysInlineFunction(llvm::Function *Fn) {
+ AlwaysInlineFunctions.push_back(Fn);
+}
+
+/// Find all uses of GV that are not direct calls or invokes.
+static void FindNonDirectCallUses(llvm::GlobalValue *GV,
+ llvm::SmallVectorImpl<llvm::Use *> *Uses) {
+ llvm::GlobalValue::use_iterator UI = GV->use_begin(), E = GV->use_end();
+ for (; UI != E;) {
+ llvm::Use &U = *UI;
+ ++UI;
+
+ llvm::CallSite CS(U.getUser());
+ bool isDirectCall = (CS.isCall() || CS.isInvoke()) && CS.isCallee(&U);
+ if (!isDirectCall)
+ Uses->push_back(&U);
+ }
+}
+
+/// Replace a list of uses.
+static void ReplaceUsesWith(const llvm::SmallVectorImpl<llvm::Use *> &Uses,
+ llvm::GlobalValue *V,
+ llvm::GlobalValue *Replacement) {
+ for (llvm::Use *U : Uses) {
+ auto *C = dyn_cast<llvm::Constant>(U->getUser());
+ if (C && !isa<llvm::GlobalValue>(C))
+ C->handleOperandChange(V, Replacement, U);
+ else
+ U->set(Replacement);
+ }
+}
+
+void CodeGenModule::RewriteAlwaysInlineFunction(llvm::Function *Fn) {
+ std::string Name = Fn->getName();
+ std::string InlineName = Name + ".alwaysinline";
+ Fn->setName(InlineName);
+
+ llvm::SmallVector<llvm::Use *, 8> NonDirectCallUses;
+ Fn->removeDeadConstantUsers();
+ FindNonDirectCallUses(Fn, &NonDirectCallUses);
+ // Do not create the wrapper if there are no non-direct call uses, and we are
+ // not required to emit an external definition.
+ if (NonDirectCallUses.empty() && Fn->isDiscardableIfUnused())
+ return;
+
+ llvm::FunctionType *FT = Fn->getFunctionType();
+ llvm::LLVMContext &Ctx = getModule().getContext();
+ llvm::Function *StubFn =
+ llvm::Function::Create(FT, Fn->getLinkage(), Name, &getModule());
+ assert(StubFn->getName() == Name && "name was uniqued!");
+
+ // Insert the stub immediately after the original function. Helps with the
+ // fragile tests, among other things.
+ StubFn->removeFromParent();
+ TheModule.getFunctionList().insertAfter(Fn, StubFn);
+
+ StubFn->copyAttributesFrom(Fn);
+ StubFn->setPersonalityFn(nullptr);
+
+ // AvailableExternally functions are replaced with a declaration.
+ // Everyone else gets a wrapper that musttail-calls the original function.
+ if (Fn->hasAvailableExternallyLinkage()) {
+ StubFn->setLinkage(llvm::GlobalValue::ExternalLinkage);
+ } else {
+ llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", StubFn);
+ std::vector<llvm::Value *> Args;
+ for (llvm::Function::arg_iterator ai = StubFn->arg_begin();
+ ai != StubFn->arg_end(); ++ai)
+ Args.push_back(&*ai);
+ llvm::CallInst *CI = llvm::CallInst::Create(Fn, Args, "", BB);
+ CI->setCallingConv(Fn->getCallingConv());
+ CI->setTailCallKind(llvm::CallInst::TCK_MustTail);
+ CI->setAttributes(Fn->getAttributes());
+ if (FT->getReturnType()->isVoidTy())
+ llvm::ReturnInst::Create(Ctx, BB);
+ else
+ llvm::ReturnInst::Create(Ctx, CI, BB);
+ }
+
+ if (Fn->hasComdat())
+ StubFn->setComdat(Fn->getComdat());
+
+ ReplaceUsesWith(NonDirectCallUses, Fn, StubFn);
+
+ // Replace all metadata uses with the stub. This is primarily to reattach
+ // DISubprogram metadata to the stub, because that's what will be emitted in
+ // the object file.
+ if (Fn->isUsedByMetadata())
+ llvm::ValueAsMetadata::handleRAUW(Fn, StubFn);
+}
+
+void CodeGenModule::RewriteAlwaysInlineFunctions() {
+ for (llvm::Function *Fn : AlwaysInlineFunctions) {
+ RewriteAlwaysInlineFunction(Fn);
+ Fn->setLinkage(llvm::GlobalValue::InternalLinkage);
+ Fn->addFnAttr(llvm::Attribute::AlwaysInline);
+ Fn->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
+ Fn->setVisibility(llvm::GlobalValue::DefaultVisibility);
+ }
}
void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
@@ -772,7 +875,7 @@ void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
!F->getAttributes().hasAttribute(llvm::AttributeSet::FunctionIndex,
llvm::Attribute::NoInline)) {
// (noinline wins over always_inline, and we can't specify both in IR)
- B.addAttribute(llvm::Attribute::AlwaysInline);
+ AddAlwaysInlineFunction(F);
}
if (D->hasAttr<ColdAttr>()) {
diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
index 754e3d1d29f..e579f8bd5ec 100644
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -489,6 +489,8 @@ private:
/// MDNodes.
llvm::DenseMap<QualType, llvm::Metadata *> MetadataIdMap;
+ llvm::SmallVector<llvm::Function*, 8> AlwaysInlineFunctions;
+
public:
CodeGenModule(ASTContext &C, const HeaderSearchOptions &headersearchopts,
const PreprocessorOptions &ppopts,
@@ -1131,6 +1133,8 @@ public:
/// \breif Get the declaration of std::terminate for the platform.
llvm::Constant *getTerminateFn();
+ void AddAlwaysInlineFunction(llvm::Function *Fn);
+
private:
llvm::Constant *
GetOrCreateLLVMFunction(StringRef MangledName, llvm::Type *Ty, GlobalDecl D,
@@ -1226,6 +1230,12 @@ private:
/// Emits target specific Metadata for global declarations.
void EmitTargetMetadata();
+ /// Replaces alwaysinline functions with a pair of internal xxx.inlinefunction
+ /// for direct calls, and a stub for indirect calls, and rewrites all uses of
+ /// those.
+ void RewriteAlwaysInlineFunctions();
+ void RewriteAlwaysInlineFunction(llvm::Function *Fn);
+
/// Emit the llvm.gcov metadata used to tell LLVM where to emit the .gcno and
/// .gcda files in a way that persists in .bc files.
void EmitCoverageFile();
diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index 0c6a6d751c7..fa714d7ddc7 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -3311,6 +3311,9 @@ static StructorCodegen getCodegenToUse(CodeGenModule &CGM,
if (MD->getParent()->getNumVBases())
return StructorCodegen::Emit;
+ if (MD->hasAttr<AlwaysInlineAttr>())
+ return StructorCodegen::Emit;
+
GlobalDecl AliasDecl;
if (const auto *DD = dyn_cast<CXXDestructorDecl>(MD)) {
AliasDecl = GlobalDecl(DD, Dtor_Complete);
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