diff --git a/tests/codegen/maybeuninit-rvo.rs b/tests/codegen/maybeuninit-rvo.rs new file mode 100644 index 00000000000..feed513e1fb --- /dev/null +++ b/tests/codegen/maybeuninit-rvo.rs @@ -0,0 +1,33 @@ +// compile-flags: -O +#![feature(c_unwind)] +#![crate_type = "lib"] + +pub struct Foo([u8; 1000]); + +extern "C" { + fn init(p: *mut Foo); +} + +pub fn new_from_uninit() -> Foo { + // CHECK-LABEL: new_from_uninit + // CHECK-NOT: call void @llvm.memcpy. + let mut x = std::mem::MaybeUninit::uninit(); + unsafe { + init(x.as_mut_ptr()); + x.assume_init() + } +} + +extern "C-unwind" { + fn init_unwind(p: *mut Foo); +} + +pub fn new_from_uninit_unwind() -> Foo { + // CHECK-LABEL: new_from_uninit + // CHECK: call void @llvm.memcpy. + let mut x = std::mem::MaybeUninit::uninit(); + unsafe { + init_unwind(x.as_mut_ptr()); + x.assume_init() + } +}