8dcc676c92
We already did `Transmute`-then-`PtrToPtr`; this adds the nearly-identical `PtrToPtr`-then-`Transmute`.
It also adds `transmute(Foo(x))` → `transmute(x)`, when `Foo` is a single-field transparent type. That's useful for things like `NonNull { pointer: p }.as_ptr()`.
Found these as I was looking at MCP807-related changes.
72 lines
2.7 KiB
Rust
72 lines
2.7 KiB
Rust
// MIR for `vec_deref_to_slice` after PreCodegen
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fn vec_deref_to_slice(_1: &Vec<u8>) -> &[u8] {
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debug v => _1;
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let mut _0: &[u8];
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scope 1 (inlined <Vec<u8> as Deref>::deref) {
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debug self => _1;
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scope 2 (inlined Vec::<u8>::as_slice) {
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debug self => _1;
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let mut _3: *const u8;
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let mut _4: usize;
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scope 3 (inlined Vec::<u8>::as_ptr) {
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debug self => _1;
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scope 4 (inlined alloc::raw_vec::RawVec::<u8>::ptr) {
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scope 5 (inlined alloc::raw_vec::RawVecInner::ptr::<u8>) {
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scope 6 (inlined alloc::raw_vec::RawVecInner::non_null::<u8>) {
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let mut _2: std::ptr::NonNull<u8>;
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scope 7 (inlined Unique::<u8>::cast::<u8>) {
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scope 8 (inlined NonNull::<u8>::cast::<u8>) {
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scope 9 (inlined NonNull::<u8>::as_ptr) {
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}
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}
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}
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scope 10 (inlined Unique::<u8>::as_non_null_ptr) {
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}
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}
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scope 11 (inlined NonNull::<u8>::as_ptr) {
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}
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}
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}
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}
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scope 12 (inlined std::slice::from_raw_parts::<'_, u8>) {
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debug data => _3;
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debug len => _4;
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let _5: *const [u8];
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scope 13 (inlined core::ub_checks::check_language_ub) {
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scope 14 (inlined core::ub_checks::check_language_ub::runtime) {
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}
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}
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scope 15 (inlined std::mem::size_of::<u8>) {
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}
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scope 16 (inlined align_of::<u8>) {
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}
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scope 17 (inlined slice_from_raw_parts::<u8>) {
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debug data => _3;
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debug len => _4;
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scope 18 (inlined std::ptr::from_raw_parts::<[u8], u8>) {
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debug data_pointer => _3;
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}
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}
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}
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}
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}
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bb0: {
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StorageLive(_2);
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StorageLive(_3);
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_2 = copy (((((*_1).0: alloc::raw_vec::RawVec<u8>).0: alloc::raw_vec::RawVecInner).0: std::ptr::Unique<u8>).0: std::ptr::NonNull<u8>);
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_3 = copy _2 as *const u8 (Transmute);
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StorageLive(_4);
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_4 = copy ((*_1).1: usize);
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StorageLive(_5);
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_5 = *const [u8] from (copy _3, copy _4);
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_0 = &(*_5);
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StorageDead(_5);
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StorageDead(_4);
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StorageDead(_3);
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StorageDead(_2);
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return;
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}
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}
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