1 files changed, 18 insertions, 0 deletions
diff --git a/tests/codegen-llvm/become-musttail.rs b/tests/codegen-llvm/become-musttail.rs
new file mode 100644
index 00000000000..07f33571910
--- /dev/null
+++ b/tests/codegen-llvm/become-musttail.rs
@@ -0,0 +1,18 @@
+//@ compile-flags: -C opt-level=0 -Cpanic=abort -C no-prepopulate-passes
+//@ needs-unwind
+
+#![crate_type = "lib"]
+#![feature(explicit_tail_calls)]
+
+// CHECK-LABEL: define {{.*}}@fibonacci(
+#[no_mangle]
+#[inline(never)]
+pub fn fibonacci(n: u64, a: u64, b: u64) -> u64 {
+    // CHECK: musttail call {{.*}}@fibonacci(
+    // CHECK-NEXT: ret i64
+    match n {
+        0 => a,
+        1 => b,
+        _ => become fibonacci(n - 1, b, a + b),
+    }
+}