Index: test/profile/instrprof-override-filename-then-reset-default.c
===================================================================
--- /dev/null
+++ test/profile/instrprof-override-filename-then-reset-default.c
@@ -0,0 +1,19 @@
+// RUN: rm -rf %t.d
+// RUN: mkdir -p %t.d
+// RUN: cd %t.d
+// RUN: %clang_profgen -O3 %s
+// RUN: %run a.out %t.d/bad.profraw
+// RUN: llvm-profdata merge -o %t.d/default.profdata %t.d/default.profraw
+// RUN: %clang_profuse=%t.d/default.profdata -o - -S -emit-llvm %s | FileCheck %s
+
+
+void __llvm_profile_override_default_filename(const char *);
+int main(int argc, const char *argv[]) {
+  // CHECK: br i1 %{{.*}}, label %{{.*}}, label %{{.*}}, !prof ![[PD1:[0-9]+]]
+  if (argc < 2)
+    return 1;
+  __llvm_profile_override_default_filename(argv[1]);
+  __llvm_profile_override_default_filename(0);
+  return 0;
+}
+// CHECK: ![[PD1]] = !{!"branch_weights", i32 1, i32 2}
Index: test/profile/instrprof-set-filename-then-reset-default.c
===================================================================
--- /dev/null
+++ test/profile/instrprof-set-filename-then-reset-default.c
@@ -0,0 +1,18 @@
+// RUN: rm -rf %t.d
+// RUN: mkdir -p %t.d
+// RUN: cd %t.d
+// RUN: %clang_profgen -O3 %s
+// RUN: %run a.out %t.d/bad.profraw
+// RUN: llvm-profdata merge -o %t.d/default.profdata %t.d/default.profraw
+// RUN: %clang_profuse=%t.d/default.profdata -o - -S -emit-llvm %s | FileCheck %s
+
+void __llvm_profile_set_filename(const char *);
+int main(int argc, const char *argv[]) {
+  // CHECK: br i1 %{{.*}}, label %{{.*}}, label %{{.*}}, !prof ![[PD1:[0-9]+]]
+  if (argc < 2)
+    return 1;
+  __llvm_profile_set_filename(argv[1]);
+  __llvm_profile_set_filename(0);
+  return 0;
+}
+// CHECK: ![[PD1]] = !{!"branch_weights", i32 1, i32 2}