1 files changed, 24 insertions, 0 deletions
diff --git a/tests/codegen-llvm/vec_pop_push_noop.rs b/tests/codegen-llvm/vec_pop_push_noop.rs
new file mode 100644
index 00000000000..3e375219fe0
--- /dev/null
+++ b/tests/codegen-llvm/vec_pop_push_noop.rs
@@ -0,0 +1,24 @@
+//@ compile-flags: -Copt-level=3
+
+#![crate_type = "lib"]
+
+#[no_mangle]
+// CHECK-LABEL: @noop(
+pub fn noop(v: &mut Vec<u8>) {
+    // CHECK-NOT: grow_one
+    // CHECK-NOT: call
+    // CHECK: tail call void @llvm.assume
+    // CHECK-NOT: grow_one
+    // CHECK-NOT: call
+    // CHECK: {{ret|[}]}}
+    if let Some(x) = v.pop() {
+        v.push(x)
+    }
+}
+
+#[no_mangle]
+// CHECK-LABEL: @push_byte(
+pub fn push_byte(v: &mut Vec<u8>) {
+    // CHECK: call {{.*}}grow_one
+    v.push(3);
+}