CPU-Dispatch- Fix type of a member function, prevent deferrals

The member type creation for a cpu-dispatch function was not correctly
including the 'this' parameter, so ensure that the type is properly
determined. Also, disable defer in the cases of emitting the functoins,
as it can end up resulting in the wrong version being emitted.

Change-Id: I0b8fc5e0b0d1ae1a9d98fd54f35f27f6e5d5d083
llvm-svn: 345838

2 files changed, 31 insertions, 2 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 227b8833342..f55fa3f1bcb 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -2538,7 +2538,13 @@ void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
   assert(FD && "Not a FunctionDecl?");
   const auto *DD = FD->getAttr<CPUDispatchAttr>();
   assert(DD && "Not a cpu_dispatch Function?");
-  llvm::Type *DeclTy = getTypes().ConvertTypeForMem(FD->getType());
+  QualType CanonTy = Context.getCanonicalType(FD->getType());
+  llvm::Type *DeclTy = getTypes().ConvertFunctionType(CanonTy, FD);
+
+  if (const auto *CXXFD = dyn_cast<CXXMethodDecl>(FD)) {
+    const CGFunctionInfo &FInfo = getTypes().arrangeCXXMethodDeclaration(CXXFD);
+    DeclTy = getTypes().GetFunctionType(FInfo);
+  }
 
   StringRef ResolverName = getMangledName(GD);
 
@@ -2564,7 +2570,7 @@ void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
     std::string MangledName = getMangledNameImpl(*this, GD, FD, true) +
                               getCPUSpecificMangling(*this, II->getName());
     llvm::Constant *Func = GetOrCreateLLVMFunction(
-        MangledName, DeclTy, GD, /*ForVTable=*/false, /*DontDefer=*/false,
+        MangledName, DeclTy, GD, /*ForVTable=*/false, /*DontDefer=*/true,
         /*IsThunk=*/false, llvm::AttributeList(), ForDefinition);
     llvm::SmallVector<StringRef, 32> Features;
     Target.getCPUSpecificCPUDispatchFeatures(II->getName(), Features);
diff --git a/clang/test/CodeGenCXX/attr-cpuspecific.cpp b/clang/test/CodeGenCXX/attr-cpuspecific.cpp
new file mode 100644
index 00000000000..57b45e1da2e
--- /dev/null
+++ b/clang/test/CodeGenCXX/attr-cpuspecific.cpp
@@ -0,0 +1,23 @@
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -emit-llvm -o - %s | FileCheck %s --check-prefixes=CHECK,LINUX
+// RUN: %clang_cc1 -triple x86_64-windows-pc -fms-compatibility -emit-llvm -o - %s | FileCheck %s --check-prefixes=CHECK,WINDOWS
+
+struct S {
+  __attribute__((cpu_specific(atom)))
+  void Func(){}
+  __attribute__((cpu_dispatch(ivybridge,atom)))
+  void Func(){}
+};
+
+void foo() {
+  S s;
+  s.Func();
+}
+
+// LINUX: define void (%struct.S*)* @_ZN1S4FuncEv.resolver
+// LINUX: ret void (%struct.S*)* @_ZN1S4FuncEv.S
+// LINUX: ret void (%struct.S*)* @_ZN1S4FuncEv.O
+
+// WINDOWS: define dso_local void @"?Func@S@@QEAAXXZ"(%struct.S*)
+// WINDOWS: musttail call void @"?Func@S@@QEAAXXZ.S"(%struct.S* %0)
+// WINDOWS: musttail call void @"?Func@S@@QEAAXXZ.O"(%struct.S* %0)
+