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Diffstat (limited to 'crates/hir-ty/src/layout.rs')
| -rw-r--r-- | crates/hir-ty/src/layout.rs | 85 |
1 files changed, 83 insertions, 2 deletions
diff --git a/crates/hir-ty/src/layout.rs b/crates/hir-ty/src/layout.rs index a566c06a54..2a9b2debd4 100644 --- a/crates/hir-ty/src/layout.rs +++ b/crates/hir-ty/src/layout.rs @@ -7,7 +7,7 @@ use hir_def::{ Abi, FieldsShape, Integer, LayoutCalculator, LayoutS, Primitive, ReprOptions, Scalar, Size, StructKind, TargetDataLayout, WrappingRange, }, - LocalEnumVariantId, LocalFieldId, + LocalEnumVariantId, LocalFieldId, StructId, }; use la_arena::{Idx, RawIdx}; use stdx::never; @@ -77,6 +77,78 @@ impl<'a> LayoutCalculator for LayoutCx<'a> { } } +// FIXME: move this to the `rustc_abi`. +fn layout_of_simd_ty( + db: &dyn HirDatabase, + id: StructId, + subst: &Substitution, + krate: CrateId, + dl: &TargetDataLayout, +) -> Result<Arc<Layout>, LayoutError> { + let fields = db.field_types(id.into()); + + // Supported SIMD vectors are homogeneous ADTs with at least one field: + // + // * #[repr(simd)] struct S(T, T, T, T); + // * #[repr(simd)] struct S { x: T, y: T, z: T, w: T } + // * #[repr(simd)] struct S([T; 4]) + // + // where T is a primitive scalar (integer/float/pointer). + + let f0_ty = match fields.iter().next() { + Some(x) => x.1.clone().substitute(Interner, subst), + None => { + user_error!("simd type with zero fields"); + } + }; + + // The element type and number of elements of the SIMD vector + // are obtained from: + // + // * the element type and length of the single array field, if + // the first field is of array type, or + // + // * the homogeneous field type and the number of fields. + let (e_ty, e_len, is_array) = if let TyKind::Array(e_ty, _) = f0_ty.kind(Interner) { + // Extract the number of elements from the layout of the array field: + let FieldsShape::Array { count, .. } = db.layout_of_ty(f0_ty.clone(), krate)?.fields else { + user_error!("Array with non array layout"); + }; + + (e_ty.clone(), count, true) + } else { + // First ADT field is not an array: + (f0_ty, fields.iter().count() as u64, false) + }; + + // Compute the ABI of the element type: + let e_ly = db.layout_of_ty(e_ty, krate)?; + let Abi::Scalar(e_abi) = e_ly.abi else { + user_error!("simd type with inner non scalar type"); + }; + + // Compute the size and alignment of the vector: + let size = e_ly.size.checked_mul(e_len, dl).ok_or(LayoutError::SizeOverflow)?; + let align = dl.vector_align(size); + let size = size.align_to(align.abi); + + // Compute the placement of the vector fields: + let fields = if is_array { + FieldsShape::Arbitrary { offsets: [Size::ZERO].into(), memory_index: [0].into() } + } else { + FieldsShape::Array { stride: e_ly.size, count: e_len } + }; + + Ok(Arc::new(Layout { + variants: Variants::Single { index: struct_variant_idx() }, + fields, + abi: Abi::Vector { element: e_abi, count: e_len }, + largest_niche: e_ly.largest_niche, + size, + align, + })) +} + pub fn layout_of_ty_query( db: &dyn HirDatabase, ty: Ty, @@ -88,7 +160,16 @@ pub fn layout_of_ty_query( let trait_env = Arc::new(TraitEnvironment::empty(krate)); let ty = normalize(db, trait_env, ty.clone()); let result = match ty.kind(Interner) { - TyKind::Adt(AdtId(def), subst) => return db.layout_of_adt(*def, subst.clone(), krate), + TyKind::Adt(AdtId(def), subst) => { + if let hir_def::AdtId::StructId(s) = def { + let data = db.struct_data(*s); + let repr = data.repr.unwrap_or_default(); + if repr.simd() { + return layout_of_simd_ty(db, *s, subst, krate, &target); + } + }; + return db.layout_of_adt(*def, subst.clone(), krate); + } TyKind::Scalar(s) => match s { chalk_ir::Scalar::Bool => Layout::scalar( dl, |