rust/tests/mir-opt/pre-codegen/vec_deref.vec_deref_to_slice.PreCodegen.after.panic-abort.mir
DianQK c16c22cc9c
Simplify the canonical clone method to copy
The optimized clone method ends up as the following MIR:

```
_2 = copy ((*_1).0: i32);
_3 = copy ((*_1).1: u64);
_4 = copy ((*_1).2: [i8; 3]);
_0 = Foo { a: move _2, b: move _3, c: move _4 };
```

We can transform this to:

```
_0 = copy (*_1);
```
2024-09-14 13:30:35 +08:00

92 lines
4.1 KiB
Rust

// MIR for `vec_deref_to_slice` after PreCodegen
fn vec_deref_to_slice(_1: &Vec<u8>) -> &[u8] {
debug v => _1;
let mut _0: &[u8];
scope 1 (inlined <Vec<u8> as Deref>::deref) {
debug self => _1;
let mut _6: usize;
scope 2 (inlined Vec::<u8>::as_ptr) {
debug self => _1;
let mut _2: &alloc::raw_vec::RawVec<u8>;
scope 3 (inlined alloc::raw_vec::RawVec::<u8>::ptr) {
debug self => _2;
let mut _3: &alloc::raw_vec::RawVecInner;
scope 4 (inlined alloc::raw_vec::RawVecInner::ptr::<u8>) {
debug self => _3;
scope 5 (inlined alloc::raw_vec::RawVecInner::non_null::<u8>) {
debug self => _3;
let mut _4: std::ptr::NonNull<u8>;
scope 6 (inlined Unique::<u8>::cast::<u8>) {
debug ((self: Unique<u8>).0: std::ptr::NonNull<u8>) => _4;
debug ((self: Unique<u8>).1: std::marker::PhantomData<u8>) => const PhantomData::<u8>;
scope 7 (inlined NonNull::<u8>::cast::<u8>) {
debug self => _4;
scope 8 (inlined NonNull::<u8>::as_ptr) {
debug self => _4;
let mut _5: *const u8;
}
}
}
scope 9 (inlined #[track_caller] <Unique<u8> as Into<NonNull<u8>>>::into) {
debug ((self: Unique<u8>).0: std::ptr::NonNull<u8>) => _4;
debug ((self: Unique<u8>).1: std::marker::PhantomData<u8>) => const PhantomData::<u8>;
scope 10 (inlined <NonNull<u8> as From<Unique<u8>>>::from) {
debug ((unique: Unique<u8>).0: std::ptr::NonNull<u8>) => _4;
debug ((unique: Unique<u8>).1: std::marker::PhantomData<u8>) => const PhantomData::<u8>;
scope 11 (inlined Unique::<u8>::as_non_null_ptr) {
debug ((self: Unique<u8>).0: std::ptr::NonNull<u8>) => _4;
debug ((self: Unique<u8>).1: std::marker::PhantomData<u8>) => const PhantomData::<u8>;
}
}
}
}
scope 12 (inlined NonNull::<u8>::as_ptr) {
debug self => _4;
}
}
}
}
scope 13 (inlined std::slice::from_raw_parts::<'_, u8>) {
debug data => _5;
debug len => _6;
let _7: *const [u8];
scope 14 (inlined core::ub_checks::check_language_ub) {
scope 15 (inlined core::ub_checks::check_language_ub::runtime) {
}
}
scope 16 (inlined std::mem::size_of::<u8>) {
}
scope 17 (inlined align_of::<u8>) {
}
scope 18 (inlined slice_from_raw_parts::<u8>) {
debug data => _5;
debug len => _6;
scope 19 (inlined std::ptr::from_raw_parts::<[u8], u8>) {
debug data_pointer => _5;
debug metadata => _6;
}
}
}
}
bb0: {
StorageLive(_2);
_2 = &((*_1).0: alloc::raw_vec::RawVec<u8>);
StorageLive(_3);
_3 = &(((*_1).0: alloc::raw_vec::RawVec<u8>).0: alloc::raw_vec::RawVecInner);
_4 = copy (((((*_1).0: alloc::raw_vec::RawVec<u8>).0: alloc::raw_vec::RawVecInner).0: std::ptr::Unique<u8>).0: std::ptr::NonNull<u8>);
_5 = copy (_4.0: *const u8);
StorageDead(_3);
StorageDead(_2);
StorageLive(_6);
_6 = copy ((*_1).1: usize);
StorageLive(_7);
_7 = *const [u8] from (copy _5, copy _6);
_0 = &(*_7);
StorageDead(_7);
StorageDead(_6);
return;
}
}