--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/test/CodeGen/enum-bool.cpp	Tue Jun 08 06:07:14 2021 +0900
@@ -0,0 +1,49 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -S -emit-llvm -o - %s | FileCheck %s
+
+namespace dr2338 {
+namespace A {
+enum E { Zero, One };
+E a(int x) { return static_cast<E>(x); }
+// CHECK-LABEL: define{{.*}} i32 @_ZN6dr23381A1aEi
+// CHECK: ret i32 %0
+
+E b(int x) { return (E)x; }
+// CHECK-LABEL: define{{.*}} i32 @_ZN6dr23381A1bEi
+// CHECK: ret i32 %0
+
+} // namespace A
+namespace B {
+enum E : bool { Zero, One };
+E a(int x) { return static_cast<E>(x); }
+// CHECK-LABEL: define{{.*}} zeroext i1 @_ZN6dr23381B1aEi
+// CHECK: ret i1 %tobool
+
+E b(int x) { return (E)x; }
+// CHECK-LABEL: define{{.*}} zeroext i1 @_ZN6dr23381B1bEi
+// CHECK: ret i1 %tobool
+
+} // namespace B
+namespace C {
+enum class E { Zero, One };
+E a(int x) { return static_cast<E>(x); }
+// CHECK-LABEL: define{{.*}} i32 @_ZN6dr23381C1aEi
+// CHECK: ret i32 %0
+
+E b(int x) { return (E)x; }
+// CHECK-LABEL: define{{.*}} i32 @_ZN6dr23381C1bEi
+// CHECK: ret i32 %0
+
+} // namespace C
+namespace D {
+enum class E : bool { Zero, One };
+E a(int x) { return static_cast<E>(x); }
+// CHECK-LABEL: define{{.*}} zeroext i1 @_ZN6dr23381D1aEi
+// CHECK: ret i1 %tobool
+
+E b(int x) { return (E)x; }
+
+// CHECK-LABEL: define{{.*}} zeroext i1 @_ZN6dr23381D1bEi
+// CHECK: ret i1 %tobool
+
+} // namespace D
+} // namespace dr2338