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Ban non-array SIMD

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Scott McMurray 2024-08-22 01:28:20 -07:00
parent 712463de61
commit d2309c2a9d
111 changed files with 814 additions and 1101 deletions
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38
compiler/rustc_middle/src/ty/sty.rs
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@ -1091,29 +1091,21 @@ impl<'tcx> Ty<'tcx> {
}
pub fn simd_size_and_type(self, tcx: TyCtxt<'tcx>) -> (u64, Ty<'tcx>) {
match self.kind() {
Adt(def, args) => {
assert!(def.repr().simd(), "`simd_size_and_type` called on non-SIMD type");
let variant = def.non_enum_variant();
let f0_ty = variant.fields[FieldIdx::ZERO].ty(tcx, args);
match f0_ty.kind() {
// If the first field is an array, we assume it is the only field and its
// elements are the SIMD components.
Array(f0_elem_ty, f0_len) => {
// FIXME(repr_simd): https://github.com/rust-lang/rust/pull/78863#discussion_r522784112
// The way we evaluate the `N` in `[T; N]` here only works since we use
// `simd_size_and_type` post-monomorphization. It will probably start to ICE
// if we use it in generic code. See the `simd-array-trait` ui test.
(f0_len.eval_target_usize(tcx, ParamEnv::empty()), *f0_elem_ty)
}
// Otherwise, the fields of this Adt are the SIMD components (and we assume they
// all have the same type).
_ => (variant.fields.len() as u64, f0_ty),
}
}
_ => bug!("`simd_size_and_type` called on invalid type"),
}
let Adt(def, args) = self.kind() else {
bug!("`simd_size_and_type` called on invalid type")
};
assert!(def.repr().simd(), "`simd_size_and_type` called on non-SIMD type");
let variant = def.non_enum_variant();
assert_eq!(variant.fields.len(), 1);
let field_ty = variant.fields[FieldIdx::ZERO].ty(tcx, args);
let Array(f0_elem_ty, f0_len) = field_ty.kind() else {
bug!("Simd type has non-array field type {field_ty:?}")
};
// FIXME(repr_simd): https://github.com/rust-lang/rust/pull/78863#discussion_r522784112
// The way we evaluate the `N` in `[T; N]` here only works since we use
// `simd_size_and_type` post-monomorphization. It will probably start to ICE
// if we use it in generic code. See the `simd-array-trait` ui test.
(f0_len.eval_target_usize(tcx, ParamEnv::empty()), *f0_elem_ty)
}
#[inline]