1 files changed, 24 insertions, 3 deletions
diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index eedf70b8d5..be7dfc97a9 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -2836,11 +2836,13 @@ void CodeGenModule::emitMultiVersionFunctions() {
     llvm::Function *ResolverFunc;
     const TargetInfo &TI = getTarget();
 
-    if (TI.supportsIFunc() || FD->isTargetMultiVersion())
+    if (TI.supportsIFunc() || FD->isTargetMultiVersion()) {
       ResolverFunc = cast<llvm::Function>(
           GetGlobalValue((getMangledName(GD) + ".resolver").str()));
-    else
+      ResolverFunc->setLinkage(llvm::Function::WeakODRLinkage);
+    } else {
       ResolverFunc = cast<llvm::Function>(GetGlobalValue(getMangledName(GD)));
+    }
 
     if (supportsCOMDAT())
       ResolverFunc->setComdat(
@@ -2884,6 +2886,10 @@ void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
 
   auto *ResolverFunc = cast<llvm::Function>(GetOrCreateLLVMFunction(
       ResolverName, ResolverType, ResolverGD, /*ForVTable=*/false));
+  ResolverFunc->setLinkage(llvm::Function::WeakODRLinkage);
+  if (supportsCOMDAT())
+    ResolverFunc->setComdat(
+        getModule().getOrInsertComdat(ResolverFunc->getName()));
 
   SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
   const TargetInfo &Target = getTarget();
@@ -2948,6 +2954,21 @@ void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
 
   CodeGenFunction CGF(*this);
   CGF.EmitMultiVersionResolver(ResolverFunc, Options);
+
+  if (getTarget().supportsIFunc()) {
+    std::string AliasName = getMangledNameImpl(
+        *this, GD, FD, /*OmitMultiVersionMangling=*/true);
+    llvm::Constant *AliasFunc = GetGlobalValue(AliasName);
+    if (!AliasFunc) {
+      auto *IFunc = cast<llvm::GlobalIFunc>(GetOrCreateLLVMFunction(
+          AliasName, DeclTy, GD, /*ForVTable=*/false, /*DontDefer=*/true,
+          /*IsThunk=*/false, llvm::AttributeList(), NotForDefinition));
+      auto *GA = llvm::GlobalAlias::create(
+         DeclTy, 0, getFunctionLinkage(GD), AliasName, IFunc, &getModule());
+      GA->setLinkage(llvm::Function::WeakODRLinkage);
+      SetCommonAttributes(GD, GA);
+    }
+  }
 }
 
 /// If a dispatcher for the specified mangled name is not in the module, create
@@ -2984,7 +3005,7 @@ llvm::Constant *CodeGenModule::GetOrCreateMultiVersionResolver(
         MangledName + ".resolver", ResolverType, GlobalDecl{},
         /*ForVTable=*/false);
     llvm::GlobalIFunc *GIF = llvm::GlobalIFunc::create(
-        DeclTy, 0, llvm::Function::ExternalLinkage, "", Resolver, &getModule());
+        DeclTy, 0, llvm::Function::WeakODRLinkage, "", Resolver, &getModule());
     GIF->setName(ResolverName);
     SetCommonAttributes(FD, GIF);