Add inreg attributes to reference arguments.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@145189 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGCall.cpp b/lib/CodeGen/CGCall.cpp
index 7ff16dd..4f2210f 100644
--- a/lib/CodeGen/CGCall.cpp
+++ b/lib/CodeGen/CGCall.cpp
@@ -831,7 +831,8 @@
       // 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)
diff --git a/test/CodeGenCXX/regparm.cpp b/test/CodeGenCXX/regparm.cpp
new file mode 100644
index 0000000..f0ebd2b
--- /dev/null
+++ b/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) {
+}