Index: test/CodeGen/Inputs/thinlto_backend.ll
===================================================================
--- /dev/null
+++ test/CodeGen/Inputs/thinlto_backend.ll
@@ -0,0 +1,6 @@
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @f2() {
+  ret void
+}
Index: test/CodeGen/thinlto_backend.c
===================================================================
--- test/CodeGen/thinlto_backend.c
+++ /dev/null
@@ -1,14 +0,0 @@
-// RUN: %clang -O2 %s -flto=thin -c -o %t.o
-// RUN: llvm-lto -thinlto -o %t %t.o
-
-// Ensure clang -cc1 give expected error for incorrect input type
-// RUN: not %clang_cc1 -O2 -o %t1.o %s -c -fthinlto-index=%t.thinlto.bc 2>&1 | FileCheck %s -check-prefix=CHECK-WARNING
-// CHECK-WARNING: error: invalid argument '-fthinlto-index={{.*}}' only allowed with '-x ir'
-
-// Ensure we get expected error for missing index file
-// RUN: %clang -O2 -o %t1.o -x ir %t.o -c -fthinlto-index=bad.thinlto.bc 2>&1 | FileCheck %s -check-prefix=CHECK-ERROR
-// CHECK-ERROR: Error loading index file 'bad.thinlto.bc'
-
-// Ensure Function Importing pass added
-// RUN: %clang -O2 -o %t1.o -x ir %t.o -c -fthinlto-index=%t.thinlto.bc -mllvm -debug-pass=Structure 2>&1 | FileCheck %s -check-prefix=CHECK-PASS
-// CHECK-PASS: Function Importing
Index: test/CodeGen/thinlto_backend.ll
===================================================================
--- /dev/null
+++ test/CodeGen/thinlto_backend.ll
@@ -0,0 +1,27 @@
+; RUN: opt -module-summary -o %t1.o %s
+; RUN: opt -module-summary -o %t2.o %S/Inputs/thinlto_backend.ll
+; RUN: llvm-lto -thinlto -o %t %t1.o %t2.o
+
+; Ensure clang -cc1 give expected error for incorrect input type
+; RUN: not %clang_cc1 -O2 -o %t1.o -x c %s -c -fthinlto-index=%t.thinlto.bc 2>&1 | FileCheck %s -check-prefix=CHECK-WARNING
+; CHECK-WARNING: error: invalid argument '-fthinlto-index={{.*}}' only allowed with '-x ir'
+
+; Ensure we get expected error for missing index file
+; RUN: %clang -O2 -o %t3.o -x ir %t1.o -c -fthinlto-index=bad.thinlto.bc 2>&1 | FileCheck %s -check-prefix=CHECK-ERROR
+; CHECK-ERROR: Error loading index file 'bad.thinlto.bc'
+
+; Ensure f2 was imported
+; RUN: %clang -O2 -o %t3.o -x ir %t1.o -c -fthinlto-index=%t.thinlto.bc
+; RUN: llvm-nm %t3.o | FileCheck --check-prefix=CHECK-OBJ %s
+; CHECK-OBJ: T f1
+; CHECK-OBJ-NOT: U f2
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+declare void @f2()
+
+define void @f1() {
+  call void @f2()
+  ret void
+}