rust/tests/codegen/maybeuninit-rvo.rs

34 lines
678 B
Rust

//@ 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()
}
}