Add inreg attributes to reference arguments.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@145189 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/CGCall.cpp

@@ -831,7 +831,8 @@ void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI,
       // FALL THROUGH
     case ABIArgInfo::Direct:
       if (RegParm > 0 &&
-          (ParamType->isIntegerType() || ParamType->isPointerType())) {
+          (ParamType->isIntegerType() || ParamType->isPointerType() ||
+           ParamType->isReferenceType())) {
         RegParm -=
         (Context.getTypeSize(ParamType) + PointerWidth - 1) / PointerWidth;
         if (RegParm >= 0)

test/CodeGenCXX/regparm.cpp

@@ -0,0 +1,6 @@
+// RUN: %clang_cc1 -triple i386-unknown-unknown %s -emit-llvm -o - | FileCheck %s
+
+
+// CHECK: _Z3fooRi(i32* inreg
+void __attribute__ ((regparm (1)))  foo(int &a) {
+}