| // in Rust 1.73, -O and opt-level=3 optimizes differently | |
| //@ compile-flags: -C opt-level=3 | |
| #![crate_type = "lib"] | |
| use std::cmp::max; | |
| // CHECK-LABEL: @foo | |
| // CHECK-NOT: slice_start_index_len_fail | |
| // CHECK-NOT: unreachable | |
| #[no_mangle] | |
| pub fn foo(v: &mut Vec<u8>, size: usize) -> Option<&mut [u8]> { | |
| if v.len() > max(1, size) { | |
| let start = v.len() - size; | |
| Some(&mut v[start..]) | |
| } else { | |
| None | |
| } | |
| } |