1 files changed, 24 insertions, 0 deletions
diff --git a/tests/codegen/enum-bounds-check-derived-idx.rs b/tests/codegen/enum-bounds-check-derived-idx.rs
new file mode 100644
index 000000000..aa66c2ed0
--- /dev/null
+++ b/tests/codegen/enum-bounds-check-derived-idx.rs
@@ -0,0 +1,24 @@
+// This test checks an optimization that is not guaranteed to work. This test case should not block
+// a future LLVM update.
+// compile-flags: -O
+
+#![crate_type = "lib"]
+
+pub enum Bar {
+    A = 1,
+    B = 3,
+}
+
+// CHECK-LABEL: @lookup_inc
+#[no_mangle]
+pub fn lookup_inc(buf: &[u8; 5], f: Bar) -> u8 {
+    // CHECK-NOT: panic_bounds_check
+    buf[f as usize + 1]
+}
+
+// CHECK-LABEL: @lookup_dec
+#[no_mangle]
+pub fn lookup_dec(buf: &[u8; 5], f: Bar) -> u8 {
+    // CHECK-NOT: panic_bounds_check
+    buf[f as usize - 1]
+}