changes from last revision:

* changed the condition for early exit
* assert that the first lookup returned null if you are at the fallthrough

Author: labrinea

clang/lib/CodeGen/CodeGenModule.cpp

@@ -4554,15 +4554,17 @@ llvm::Constant *CodeGenModule::GetOrCreateMultiVersionResolver(GlobalDecl GD) {
     ResolverName += ".resolver";
   }
 
+  bool ShouldReturnIFunc =
+      getTarget().supportsIFunc() && !FD->isCPUSpecificMultiVersion();
+
   // If the resolver has already been created, just return it. This lookup may
   // yield a function declaration instead of a resolver on AArch64. That is
   // because we didn't know whether a resolver will be generated when we first
   // encountered a use of the symbol named after this resolver. Therefore,
   // targets which support ifuncs should not return here unless we actually
   // found an ifunc.
   llvm::GlobalValue *ResolverGV = GetGlobalValue(ResolverName);
-  if (ResolverGV &&
-      (isa<llvm::GlobalIFunc>(ResolverGV) || !getTarget().supportsIFunc()))
+  if (ResolverGV && (isa<llvm::GlobalIFunc>(ResolverGV) || !ShouldReturnIFunc))
     return ResolverGV;
 
   const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
@@ -4575,7 +4577,7 @@ llvm::Constant *CodeGenModule::GetOrCreateMultiVersionResolver(GlobalDecl GD) {
 
   // For cpu_specific, don't create an ifunc yet because we don't know if the
   // cpu_dispatch will be emitted in this translation unit.
-  if (getTarget().supportsIFunc() && !FD->isCPUSpecificMultiVersion()) {
+  if (ShouldReturnIFunc) {
     unsigned AS = getTypes().getTargetAddressSpace(FD->getType());
     llvm::Type *ResolverType =
         llvm::FunctionType::get(llvm::PointerType::get(DeclTy, AS), false);
@@ -4594,7 +4596,7 @@ llvm::Constant *CodeGenModule::GetOrCreateMultiVersionResolver(GlobalDecl GD) {
 
   llvm::Constant *Resolver = GetOrCreateLLVMFunction(
       ResolverName, DeclTy, GlobalDecl{}, /*ForVTable=*/false);
-  assert(isa<llvm::GlobalValue>(Resolver) &&
+  assert(isa<llvm::GlobalValue>(Resolver) && !ResolverGV &&
          "Resolver should be created for the first time");
   SetCommonAttributes(FD, cast<llvm::GlobalValue>(Resolver));
   return Resolver;