1 files changed, 34 insertions, 0 deletions
diff --git a/tests/codegen/box-maybe-uninit-llvm14.rs b/tests/codegen/box-maybe-uninit-llvm14.rs
new file mode 100644
index 000000000..b0c88f76c
--- /dev/null
+++ b/tests/codegen/box-maybe-uninit-llvm14.rs
@@ -0,0 +1,34 @@
+// compile-flags: -O
+
+// Once we're done with llvm 14 and earlier, this test can be deleted.
+
+#![crate_type = "lib"]
+
+use std::mem::MaybeUninit;
+
+// Boxing a `MaybeUninit` value should not copy junk from the stack
+#[no_mangle]
+pub fn box_uninitialized() -> Box<MaybeUninit<usize>> {
+    // CHECK-LABEL: @box_uninitialized
+    // CHECK-NOT: store
+    // CHECK-NOT: alloca
+    // CHECK-NOT: memcpy
+    // CHECK-NOT: memset
+    Box::new(MaybeUninit::uninit())
+}
+
+// https://github.com/rust-lang/rust/issues/58201
+#[no_mangle]
+pub fn box_uninitialized2() -> Box<MaybeUninit<[usize; 1024 * 1024]>> {
+    // CHECK-LABEL: @box_uninitialized2
+    // CHECK-NOT: store
+    // CHECK-NOT: alloca
+    // CHECK-NOT: memcpy
+    // CHECK-NOT: memset
+    Box::new(MaybeUninit::uninit())
+}
+
+// Hide the LLVM 15+ `allocalign` attribute in the declaration of __rust_alloc
+// from the CHECK-NOT above. We don't check the attributes here because we can't rely
+// on all of them being set until LLVM 15.
+// CHECK: declare noalias{{.*}} @__rust_alloc(i{{[0-9]+}} noundef, i{{[0-9]+.*}} noundef)