26 lines
655 B
Rust
26 lines
655 B
Rust
|
//@ compile-flags: -Copt-level=0
|
||
|
|
|
||
|
|
// Test to make sure that `<Box<T>>::default` does not create too many copies of `T` on the stack.
|
||
|
|
// in debug mode. This regressed in dd0620b86721ae8cae86736443acd3f72ba6fc32 to
|
||
|
|
// four `T` allocas.
|
||
|
|
//
|
||
|
|
// See https://github.com/rust-lang/rust/issues/136043 for more context.
|
||
|
|
|
||
|
|
#![crate_type = "lib"]
|
||
|
|
|
||
|
|
#[allow(dead_code)]
|
||
|
|
pub struct Thing([u8; 1000000]);
|
||
|
|
|
||
|
|
impl Default for Thing {
|
||
|
|
fn default() -> Self {
|
||
|
|
Thing([0; 1000000])
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// CHECK-COUNT-4: %{{.*}} = alloca {{.*}}1000000
|
||
|
|
// CHECK-NOT: %{{.*}} = alloca {{.*}}1000000
|
||
|
|
#[no_mangle]
|
||
|
|
pub fn box_default_single_copy() -> Box<Thing> {
|
||
|
|
Box::default()
|
||
|
|
}
|