| // 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 {{(dso_local )?}}noalias{{.*}} @__rust_alloc(i{{[0-9]+}} noundef, i{{[0-9]+.*}} noundef) |
