| // ignore-debug: the debug assertions get in the way |
| // compile-flags: -O -Z merge-functions=disabled |
| #![crate_type = "lib"] |
| |
| // Ensure that trivial casts of vec elements are O(1) |
| |
| pub struct Wrapper<T>(T); |
| |
| #[repr(C)] |
| pub struct Foo { |
| a: u64, |
| b: u64, |
| c: u64, |
| d: u64, |
| } |
| |
| // Going from an aggregate struct to another type currently requires Copy to |
| // enable the TrustedRandomAccess specialization. Without it optimizations do not yet |
| // reliably recognize the loops as noop for repr(C) or non-Copy structs. |
| #[derive(Copy, Clone)] |
| pub struct Bar { |
| a: u64, |
| b: u64, |
| c: u64, |
| d: u64, |
| } |
| |
| // CHECK-LABEL: @vec_iterator_cast_primitive |
| #[no_mangle] |
| pub fn vec_iterator_cast_primitive(vec: Vec<i8>) -> Vec<u8> { |
| // CHECK-NOT: loop |
| // CHECK-NOT: call |
| vec.into_iter().map(|e| e as u8).collect() |
| } |
| |
| // CHECK-LABEL: @vec_iterator_cast_wrapper |
| #[no_mangle] |
| pub fn vec_iterator_cast_wrapper(vec: Vec<u8>) -> Vec<Wrapper<u8>> { |
| // CHECK-NOT: loop |
| // CHECK-NOT: call |
| vec.into_iter().map(|e| Wrapper(e)).collect() |
| } |
| |
| // CHECK-LABEL: @vec_iterator_cast_unwrap |
| #[no_mangle] |
| pub fn vec_iterator_cast_unwrap(vec: Vec<Wrapper<u8>>) -> Vec<u8> { |
| // CHECK-NOT: loop |
| // CHECK-NOT: call |
| vec.into_iter().map(|e| e.0).collect() |
| } |
| |
| // CHECK-LABEL: @vec_iterator_cast_aggregate |
| #[no_mangle] |
| pub fn vec_iterator_cast_aggregate(vec: Vec<[u64; 4]>) -> Vec<Foo> { |
| // FIXME These checks should be the same as other functions. |
| // CHECK-NOT: @__rust_alloc |
| // CHECK-NOT: @__rust_alloc |
| vec.into_iter().map(|e| unsafe { std::mem::transmute(e) }).collect() |
| } |
| |
| // CHECK-LABEL: @vec_iterator_cast_deaggregate |
| #[no_mangle] |
| pub fn vec_iterator_cast_deaggregate(vec: Vec<Bar>) -> Vec<[u64; 4]> { |
| // FIXME These checks should be the same as other functions. |
| // CHECK-NOT: @__rust_alloc |
| // CHECK-NOT: @__rust_alloc |
| |
| // Safety: For the purpose of this test we assume that Bar layout matches [u64; 4]. |
| // This currently is not guaranteed for repr(Rust) types, but it happens to work here and |
| // the UCG may add additional guarantees for homogenous types in the future that would make this |
| // correct. |
| vec.into_iter().map(|e| unsafe { std::mem::transmute(e) }).collect() |
| } |