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Move SIMD layout logic to rustc_abi

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Moulins
2025-03-07 21:17:16 +01:00
parent 9917173575
commit e69491ac60
5 changed files with 117 additions and 79 deletions
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79
compiler/rustc_ty_utils/src/layout.rs
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@@ -5,9 +5,9 @@ use hir::def_id::DefId;
use rustc_abi::Integer::{I8, I32};
use rustc_abi::Primitive::{self, Float, Int, Pointer};
use rustc_abi::{
AbiAndPrefAlign, AddressSpace, Align, BackendRepr, FIRST_VARIANT, FieldIdx, FieldsShape,
HasDataLayout, Layout, LayoutCalculatorError, LayoutData, Niche, ReprOptions, Scalar, Size,
StructKind, TagEncoding, VariantIdx, Variants, WrappingRange,
AddressSpace, BackendRepr, FIRST_VARIANT, FieldIdx, FieldsShape, HasDataLayout, Layout,
LayoutCalculatorError, LayoutData, Niche, ReprOptions, Scalar, Size, StructKind, TagEncoding,
VariantIdx, Variants, WrappingRange,
};
use rustc_hashes::Hash64;
use rustc_index::bit_set::DenseBitSet;
@@ -16,7 +16,7 @@ use rustc_middle::bug;
use rustc_middle::mir::{CoroutineLayout, CoroutineSavedLocal};
use rustc_middle::query::Providers;
use rustc_middle::ty::layout::{
FloatExt, HasTyCtxt, IntegerExt, LayoutCx, LayoutError, LayoutOf, MAX_SIMD_LANES, TyAndLayout,
FloatExt, HasTyCtxt, IntegerExt, LayoutCx, LayoutError, LayoutOf, TyAndLayout,
};
use rustc_middle::ty::print::with_no_trimmed_paths;
use rustc_middle::ty::{
@@ -124,6 +124,19 @@ fn map_error<'tcx>(
.delayed_bug(format!("computed impossible repr (packed enum?): {ty:?}"));
LayoutError::ReferencesError(guar)
}
LayoutCalculatorError::ZeroLengthSimdType => {
// Can't be caught in typeck if the array length is generic.
cx.tcx().dcx().emit_fatal(ZeroLengthSimdType { ty })
}
LayoutCalculatorError::OversizedSimdType { max_lanes } => {
// Can't be caught in typeck if the array length is generic.
cx.tcx().dcx().emit_fatal(OversizedSimdType { ty, max_lanes })
}
LayoutCalculatorError::NonPrimitiveSimdType(field) => {
// This error isn't caught in typeck, e.g., if
// the element type of the vector is generic.
cx.tcx().dcx().emit_fatal(NonPrimitiveSimdType { ty, e_ty: field.ty })
}
};
error(cx, err)
}
@@ -423,65 +436,9 @@ fn layout_of_uncached<'tcx>(
.try_to_target_usize(tcx)
.ok_or_else(|| error(cx, LayoutError::Unknown(ty)))?;
// SIMD vectors of zero length are not supported.
// Additionally, lengths are capped at 2^16 as a fixed maximum backends must
// support.
//
// Can't be caught in typeck if the array length is generic.
if e_len == 0 {
tcx.dcx().emit_fatal(ZeroLengthSimdType { ty });
} else if e_len > MAX_SIMD_LANES {
tcx.dcx().emit_fatal(OversizedSimdType { ty, max_lanes: MAX_SIMD_LANES });
}
// Compute the ABI of the element type:
let e_ly = cx.layout_of(e_ty)?;
let BackendRepr::Scalar(e_abi) = e_ly.backend_repr else {
// This error isn't caught in typeck, e.g., if
// the element type of the vector is generic.
tcx.dcx().emit_fatal(NonPrimitiveSimdType { ty, e_ty });
};
// Compute the size and alignment of the vector:
let size = e_ly
.size
.checked_mul(e_len, dl)
.ok_or_else(|| error(cx, LayoutError::SizeOverflow(ty)))?;
let (abi, align) = if def.repr().packed() && !e_len.is_power_of_two() {
// Non-power-of-two vectors have padding up to the next power-of-two.
// If we're a packed repr, remove the padding while keeping the alignment as close
// to a vector as possible.
(
BackendRepr::Memory { sized: true },
AbiAndPrefAlign {
abi: Align::max_aligned_factor(size),
pref: dl.llvmlike_vector_align(size).pref,
},
)
} else {
(
BackendRepr::SimdVector { element: e_abi, count: e_len },
dl.llvmlike_vector_align(size),
)
};
let size = size.align_to(align.abi);
tcx.mk_layout(LayoutData {
variants: Variants::Single { index: FIRST_VARIANT },
fields: FieldsShape::Arbitrary {
offsets: [Size::ZERO].into(),
memory_index: [0].into(),
},
backend_repr: abi,
largest_niche: e_ly.largest_niche,
uninhabited: false,
size,
align,
max_repr_align: None,
unadjusted_abi_align: align.abi,
randomization_seed: e_ly.randomization_seed.wrapping_add(Hash64::new(e_len)),
})
map_layout(cx.calc.simd_type(e_ly, e_len, def.repr().packed()))?
}
// ADTs.