Index: lib/CodeGen/TargetInfo.cpp
===================================================================
--- lib/CodeGen/TargetInfo.cpp
+++ lib/CodeGen/TargetInfo.cpp
@@ -4260,6 +4260,11 @@
 public:
   AArch64ABIInfo(CodeGenTypes &CGT, ABIKind Kind) : ABIInfo(CGT), Kind(Kind) {}
 
+  bool isAndroid() const {
+    return (getTarget().getTriple().getEnvironment() ==
+            llvm::Triple::Android);
+  }
+
 private:
   ABIKind getABIKind() const { return Kind; }
   bool isDarwinPCS() const { return Kind == DarwinPCS; }
@@ -4316,6 +4321,11 @@
   // Handle illegal vector types here.
   if (isIllegalVectorType(Ty)) {
     uint64_t Size = getContext().getTypeSize(Ty);
+    // Android promotes <2 x i8> to i16, not i32
+    if(AArch64ABIInfo::isAndroid() && (Size <= 16)) {
+      llvm::Type *ResType = llvm::Type::getInt16Ty(getVMContext());
+      return ABIArgInfo::getDirect(ResType);
+    }
     if (Size <= 32) {
       llvm::Type *ResType = llvm::Type::getInt32Ty(getVMContext());
       return ABIArgInfo::getDirect(ResType);
Index: test/CodeGen/aarch64-abi-vector.c
===================================================================
--- /dev/null
+++ test/CodeGen/aarch64-abi-vector.c
@@ -0,0 +1,25 @@
+// RUN: %clang_cc1 -triple aarch64-linux-android -emit-llvm -o - %s | tee /tmp/testout | FileCheck -check-prefix=ANDROID %s
+
+#include <stdarg.h>
+
+typedef __attribute__(( ext_vector_type(2) ))  char __char2;
+
+// Passing legal vector types as varargs. Check that we've allocated the appropriate size
+double varargs_vec_2c(int fixed, ...) {
+// ANDROID: varargs_vec_2c
+// ANDROID: [[VAR:%.*]] = alloca <2 x i8>, align 2
+// ANDROID: [[AP_NEXT:%.*]] = getelementptr inbounds i8, i8* [[AP_CUR:%.*]], i64 8
+// ANDROID: bitcast i8* [[AP_CUR]] to <2 x i8>*
+  va_list ap;
+  double sum = fixed;
+  va_start(ap, fixed);
+  __char2 c3 = va_arg(ap, __char2);
+  sum = sum + c3.x + c3.y;
+  va_end(ap);
+  return sum;
+}
+
+double test_2c(__char2 *in) {
+// ANDROID: call double (i32, ...) @varargs_vec_2c(i32 3, i16 {{%.*}})
+  return varargs_vec_2c(3, *in);
+}