move things from rustc_target::abi to rustc_abi

6 files changed, 138 insertions, 2485 deletions

diff --git a/compiler/rustc_target/src/abi/call/mod.rs b/compiler/rustc_target/src/abi/call/mod.rs
index 0c559ec04a4..a5ffaebea0b 100644
--- a/compiler/rustc_target/src/abi/call/mod.rs
+++ b/compiler/rustc_target/src/abi/call/mod.rs
@@ -262,7 +262,7 @@ impl CastTarget {
         let mut size = self.rest.total;
         for i in 0..self.prefix.iter().count() {
             match self.prefix[i] {
-                Some(v) => size += Size { raw: v.size.bytes() },
+                Some(v) => size += v.size,
                 None => {}
             }
         }
diff --git a/compiler/rustc_target/src/abi/call/sparc64.rs b/compiler/rustc_target/src/abi/call/sparc64.rs
index 1b74959ad17..ec8f20fe692 100644
--- a/compiler/rustc_target/src/abi/call/sparc64.rs
+++ b/compiler/rustc_target/src/abi/call/sparc64.rs
@@ -87,8 +87,8 @@ where
         _ => {}
     }
 
-    if (offset.raw % 4) != 0 && scalar2.primitive().is_float() {
-        offset.raw += 4 - (offset.raw % 4);
+    if (offset.bytes() % 4) != 0 && scalar2.primitive().is_float() {
+        offset += Size::from_bytes(4 - (offset.bytes() % 4));
     }
     data = arg_scalar(cx, &scalar2, offset, data);
     return data;
@@ -169,14 +169,14 @@ where
                     has_float: false,
                     arg_attribute: ArgAttribute::default(),
                 },
-                Size { raw: 0 },
+                Size::ZERO,
             );
 
             if data.has_float {
                 // Structure { float, int, int } doesn't like to be handled like
                 // { float, long int }. Other way around it doesn't mind.
                 if data.last_offset < arg.layout.size
-                    && (data.last_offset.raw % 8) != 0
+                    && (data.last_offset.bytes() % 8) != 0
                     && data.prefix_index < data.prefix.len()
                 {
                     data.prefix[data.prefix_index] = Some(Reg::i32());
@@ -185,7 +185,7 @@ where
                 }
 
                 let mut rest_size = arg.layout.size - data.last_offset;
-                if (rest_size.raw % 8) != 0 && data.prefix_index < data.prefix.len() {
+                if (rest_size.bytes() % 8) != 0 && data.prefix_index < data.prefix.len() {
                     data.prefix[data.prefix_index] = Some(Reg::i32());
                     rest_size = rest_size - Reg::i32().size;
                 }
@@ -214,13 +214,13 @@ where
     C: HasDataLayout,
 {
     if !fn_abi.ret.is_ignore() {
-        classify_arg(cx, &mut fn_abi.ret, Size { raw: 32 });
+        classify_arg(cx, &mut fn_abi.ret, Size::from_bytes(32));
     }
 
     for arg in fn_abi.args.iter_mut() {
         if arg.is_ignore() {
             continue;
         }
-        classify_arg(cx, arg, Size { raw: 16 });
+        classify_arg(cx, arg, Size::from_bytes(16));
     }
 }
diff --git a/compiler/rustc_target/src/abi/layout.rs b/compiler/rustc_target/src/abi/layout.rs
deleted file mode 100644
index cf4843e9d6c..00000000000
--- a/compiler/rustc_target/src/abi/layout.rs
+++ /dev/null
@@ -1,943 +0,0 @@
-use super::*;
-use std::{
-    borrow::Borrow,
-    cmp,
-    fmt::Debug,
-    iter,
-    ops::{Bound, Deref},
-};
-
-use rand::{seq::SliceRandom, SeedableRng};
-use rand_xoshiro::Xoshiro128StarStar;
-
-use tracing::debug;
-
-// Invert a bijective mapping, i.e. `invert(map)[y] = x` if `map[x] = y`.
-// This is used to go between `memory_index` (source field order to memory order)
-// and `inverse_memory_index` (memory order to source field order).
-// See also `FieldsShape::Arbitrary::memory_index` for more details.
-// FIXME(eddyb) build a better abstraction for permutations, if possible.
-fn invert_mapping(map: &[u32]) -> Vec<u32> {
-    let mut inverse = vec![0; map.len()];
-    for i in 0..map.len() {
-        inverse[map[i] as usize] = i as u32;
-    }
-    inverse
-}
-
-pub trait LayoutCalculator {
-    type TargetDataLayoutRef: Borrow<TargetDataLayout>;
-
-    fn delay_bug(&self, txt: &str);
-    fn current_data_layout(&self) -> Self::TargetDataLayoutRef;
-
-    fn scalar_pair<V: Idx>(&self, a: Scalar, b: Scalar) -> LayoutS<V> {
-        let dl = self.current_data_layout();
-        let dl = dl.borrow();
-        let b_align = b.align(dl);
-        let align = a.align(dl).max(b_align).max(dl.aggregate_align);
-        let b_offset = a.size(dl).align_to(b_align.abi);
-        let size = (b_offset + b.size(dl)).align_to(align.abi);
-
-        // HACK(nox): We iter on `b` and then `a` because `max_by_key`
-        // returns the last maximum.
-        let largest_niche = Niche::from_scalar(dl, b_offset, b)
-            .into_iter()
-            .chain(Niche::from_scalar(dl, Size::ZERO, a))
-            .max_by_key(|niche| niche.available(dl));
-
-        LayoutS {
-            variants: Variants::Single { index: V::new(0) },
-            fields: FieldsShape::Arbitrary {
-                offsets: vec![Size::ZERO, b_offset],
-                memory_index: vec![0, 1],
-            },
-            abi: Abi::ScalarPair(a, b),
-            largest_niche,
-            align,
-            size,
-        }
-    }
-
-    fn univariant<'a, V: Idx, F: Deref<Target = &'a LayoutS<V>> + Debug>(
-        &self,
-        dl: &TargetDataLayout,
-        fields: &[F],
-        repr: &ReprOptions,
-        kind: StructKind,
-    ) -> Option<LayoutS<V>> {
-        let pack = repr.pack;
-        let mut align = if pack.is_some() { dl.i8_align } else { dl.aggregate_align };
-        let mut inverse_memory_index: Vec<u32> = (0..fields.len() as u32).collect();
-        let optimize = !repr.inhibit_struct_field_reordering_opt();
-        if optimize {
-            let end =
-                if let StructKind::MaybeUnsized = kind { fields.len() - 1 } else { fields.len() };
-            let optimizing = &mut inverse_memory_index[..end];
-            let effective_field_align = |f: &F| {
-                if let Some(pack) = pack {
-                    // return the packed alignment in bytes
-                    f.align.abi.min(pack).bytes()
-                } else {
-                    // returns log2(effective-align).
-                    // This is ok since `pack` applies to all fields equally.
-                    // The calculation assumes that size is an integer multiple of align, except for ZSTs.
-                    //
-                    // group [u8; 4] with align-4 or [u8; 6] with align-2 fields
-                    f.align.abi.bytes().max(f.size.bytes()).trailing_zeros() as u64
-                }
-            };
-
-            // If `-Z randomize-layout` was enabled for the type definition we can shuffle
-            // the field ordering to try and catch some code making assumptions about layouts
-            // we don't guarantee
-            if repr.can_randomize_type_layout() {
-                // `ReprOptions.layout_seed` is a deterministic seed that we can use to
-                // randomize field ordering with
-                let mut rng = Xoshiro128StarStar::seed_from_u64(repr.field_shuffle_seed);
-
-                // Shuffle the ordering of the fields
-                optimizing.shuffle(&mut rng);
-
-                // Otherwise we just leave things alone and actually optimize the type's fields
-            } else {
-                match kind {
-                    StructKind::AlwaysSized | StructKind::MaybeUnsized => {
-                        optimizing.sort_by_key(|&x| {
-                            // Place ZSTs first to avoid "interesting offsets",
-                            // especially with only one or two non-ZST fields.
-                            // Then place largest alignments first, largest niches within an alignment group last
-                            let f = &fields[x as usize];
-                            let niche_size = f.largest_niche.map_or(0, |n| n.available(dl));
-                            (!f.is_zst(), cmp::Reverse(effective_field_align(f)), niche_size)
-                        });
-                    }
-
-                    StructKind::Prefixed(..) => {
-                        // Sort in ascending alignment so that the layout stays optimal
-                        // regardless of the prefix.
-                        // And put the largest niche in an alignment group at the end
-                        // so it can be used as discriminant in jagged enums
-                        optimizing.sort_by_key(|&x| {
-                            let f = &fields[x as usize];
-                            let niche_size = f.largest_niche.map_or(0, |n| n.available(dl));
-                            (effective_field_align(f), niche_size)
-                        });
-                    }
-                }
-
-                // FIXME(Kixiron): We can always shuffle fields within a given alignment class
-                //                 regardless of the status of `-Z randomize-layout`
-            }
-        }
-        // inverse_memory_index holds field indices by increasing memory offset.
-        // That is, if field 5 has offset 0, the first element of inverse_memory_index is 5.
-        // We now write field offsets to the corresponding offset slot;
-        // field 5 with offset 0 puts 0 in offsets[5].
-        // At the bottom of this function, we invert `inverse_memory_index` to
-        // produce `memory_index` (see `invert_mapping`).
-        let mut sized = true;
-        let mut offsets = vec![Size::ZERO; fields.len()];
-        let mut offset = Size::ZERO;
-        let mut largest_niche = None;
-        let mut largest_niche_available = 0;
-        if let StructKind::Prefixed(prefix_size, prefix_align) = kind {
-            let prefix_align =
-                if let Some(pack) = pack { prefix_align.min(pack) } else { prefix_align };
-            align = align.max(AbiAndPrefAlign::new(prefix_align));
-            offset = prefix_size.align_to(prefix_align);
-        }
-        for &i in &inverse_memory_index {
-            let field = &fields[i as usize];
-            if !sized {
-                self.delay_bug(&format!(
-                    "univariant: field #{} comes after unsized field",
-                    offsets.len(),
-                ));
-            }
-
-            if field.is_unsized() {
-                sized = false;
-            }
-
-            // Invariant: offset < dl.obj_size_bound() <= 1<<61
-            let field_align = if let Some(pack) = pack {
-                field.align.min(AbiAndPrefAlign::new(pack))
-            } else {
-                field.align
-            };
-            offset = offset.align_to(field_align.abi);
-            align = align.max(field_align);
-
-            debug!("univariant offset: {:?} field: {:#?}", offset, field);
-            offsets[i as usize] = offset;
-
-            if let Some(mut niche) = field.largest_niche {
-                let available = niche.available(dl);
-                if available > largest_niche_available {
-                    largest_niche_available = available;
-                    niche.offset += offset;
-                    largest_niche = Some(niche);
-                }
-            }
-
-            offset = offset.checked_add(field.size, dl)?;
-        }
-        if let Some(repr_align) = repr.align {
-            align = align.max(AbiAndPrefAlign::new(repr_align));
-        }
-        debug!("univariant min_size: {:?}", offset);
-        let min_size = offset;
-        // As stated above, inverse_memory_index holds field indices by increasing offset.
-        // This makes it an already-sorted view of the offsets vec.
-        // To invert it, consider:
-        // If field 5 has offset 0, offsets[0] is 5, and memory_index[5] should be 0.
-        // Field 5 would be the first element, so memory_index is i:
-        // Note: if we didn't optimize, it's already right.
-        let memory_index =
-            if optimize { invert_mapping(&inverse_memory_index) } else { inverse_memory_index };
-        let size = min_size.align_to(align.abi);
-        let mut abi = Abi::Aggregate { sized };
-        // Unpack newtype ABIs and find scalar pairs.
-        if sized && size.bytes() > 0 {
-            // All other fields must be ZSTs.
-            let mut non_zst_fields = fields.iter().enumerate().filter(|&(_, f)| !f.is_zst());
-
-            match (non_zst_fields.next(), non_zst_fields.next(), non_zst_fields.next()) {
-                // We have exactly one non-ZST field.
-                (Some((i, field)), None, None) => {
-                    // Field fills the struct and it has a scalar or scalar pair ABI.
-                    if offsets[i].bytes() == 0 && align.abi == field.align.abi && size == field.size
-                    {
-                        match field.abi {
-                            // For plain scalars, or vectors of them, we can't unpack
-                            // newtypes for `#[repr(C)]`, as that affects C ABIs.
-                            Abi::Scalar(_) | Abi::Vector { .. } if optimize => {
-                                abi = field.abi;
-                            }
-                            // But scalar pairs are Rust-specific and get
-                            // treated as aggregates by C ABIs anyway.
-                            Abi::ScalarPair(..) => {
-                                abi = field.abi;
-                            }
-                            _ => {}
-                        }
-                    }
-                }
-
-                // Two non-ZST fields, and they're both scalars.
-                (Some((i, a)), Some((j, b)), None) => {
-                    match (a.abi, b.abi) {
-                        (Abi::Scalar(a), Abi::Scalar(b)) => {
-                            // Order by the memory placement, not source order.
-                            let ((i, a), (j, b)) = if offsets[i] < offsets[j] {
-                                ((i, a), (j, b))
-                            } else {
-                                ((j, b), (i, a))
-                            };
-                            let pair = self.scalar_pair::<V>(a, b);
-                            let pair_offsets = match pair.fields {
-                                FieldsShape::Arbitrary { ref offsets, ref memory_index } => {
-                                    assert_eq!(memory_index, &[0, 1]);
-                                    offsets
-                                }
-                                _ => panic!(),
-                            };
-                            if offsets[i] == pair_offsets[0]
-                                && offsets[j] == pair_offsets[1]
-                                && align == pair.align
-                                && size == pair.size
-                            {
-                                // We can use `ScalarPair` only when it matches our
-                                // already computed layout (including `#[repr(C)]`).
-                                abi = pair.abi;
-                            }
-                        }
-                        _ => {}
-                    }
-                }
-
-                _ => {}
-            }
-        }
-        if fields.iter().any(|f| f.abi.is_uninhabited()) {
-            abi = Abi::Uninhabited;
-        }
-        Some(LayoutS {
-            variants: Variants::Single { index: V::new(0) },
-            fields: FieldsShape::Arbitrary { offsets, memory_index },
-            abi,
-            largest_niche,
-            align,
-            size,
-        })
-    }
-
-    fn layout_of_never_type<V: Idx>(&self) -> LayoutS<V> {
-        let dl = self.current_data_layout();
-        let dl = dl.borrow();
-        LayoutS {
-            variants: Variants::Single { index: V::new(0) },
-            fields: FieldsShape::Primitive,
-            abi: Abi::Uninhabited,
-            largest_niche: None,
-            align: dl.i8_align,
-            size: Size::ZERO,
-        }
-    }
-
-    fn layout_of_struct_or_enum<'a, V: Idx, F: Deref<Target = &'a LayoutS<V>> + Debug>(
-        &self,
-        repr: &ReprOptions,
-        variants: &IndexVec<V, Vec<F>>,
-        is_enum: bool,
-        is_unsafe_cell: bool,
-        scalar_valid_range: (Bound<u128>, Bound<u128>),
-        discr_range_of_repr: impl Fn(i128, i128) -> (Integer, bool),
-        discriminants: impl Iterator<Item = (V, i128)>,
-        niche_optimize_enum: bool,
-        always_sized: bool,
-    ) -> Option<LayoutS<V>> {
-        let dl = self.current_data_layout();
-        let dl = dl.borrow();
-
-        let scalar_unit = |value: Primitive| {
-            let size = value.size(dl);
-            assert!(size.bits() <= 128);
-            Scalar::Initialized { value, valid_range: WrappingRange::full(size) }
-        };
-
-        // A variant is absent if it's uninhabited and only has ZST fields.
-        // Present uninhabited variants only require space for their fields,
-        // but *not* an encoding of the discriminant (e.g., a tag value).
-        // See issue #49298 for more details on the need to leave space
-        // for non-ZST uninhabited data (mostly partial initialization).
-        let absent = |fields: &[F]| {
-            let uninhabited = fields.iter().any(|f| f.abi.is_uninhabited());
-            let is_zst = fields.iter().all(|f| f.is_zst());
-            uninhabited && is_zst
-        };
-        let (present_first, present_second) = {
-            let mut present_variants = variants
-                .iter_enumerated()
-                .filter_map(|(i, v)| if absent(v) { None } else { Some(i) });
-            (present_variants.next(), present_variants.next())
-        };
-        let present_first = match present_first {
-            Some(present_first) => present_first,
-            // Uninhabited because it has no variants, or only absent ones.
-            None if is_enum => {
-                return Some(self.layout_of_never_type());
-            }
-            // If it's a struct, still compute a layout so that we can still compute the
-            // field offsets.
-            None => V::new(0),
-        };
-
-        let is_struct = !is_enum ||
-                    // Only one variant is present.
-                    (present_second.is_none() &&
-                        // Representation optimizations are allowed.
-                        !repr.inhibit_enum_layout_opt());
-        if is_struct {
-            // Struct, or univariant enum equivalent to a struct.
-            // (Typechecking will reject discriminant-sizing attrs.)
-
-            let v = present_first;
-            let kind = if is_enum || variants[v].is_empty() {
-                StructKind::AlwaysSized
-            } else {
-                if !always_sized { StructKind::MaybeUnsized } else { StructKind::AlwaysSized }
-            };
-
-            let mut st = self.univariant(dl, &variants[v], &repr, kind)?;
-            st.variants = Variants::Single { index: v };
-
-            if is_unsafe_cell {
-                let hide_niches = |scalar: &mut _| match scalar {
-                    Scalar::Initialized { value, valid_range } => {
-                        *valid_range = WrappingRange::full(value.size(dl))
-                    }
-                    // Already doesn't have any niches
-                    Scalar::Union { .. } => {}
-                };
-                match &mut st.abi {
-                    Abi::Uninhabited => {}
-                    Abi::Scalar(scalar) => hide_niches(scalar),
-                    Abi::ScalarPair(a, b) => {
-                        hide_niches(a);
-                        hide_niches(b);
-                    }
-                    Abi::Vector { element, count: _ } => hide_niches(element),
-                    Abi::Aggregate { sized: _ } => {}
-                }
-                st.largest_niche = None;
-                return Some(st);
-            }
-
-            let (start, end) = scalar_valid_range;
-            match st.abi {
-                Abi::Scalar(ref mut scalar) | Abi::ScalarPair(ref mut scalar, _) => {
-                    // the asserts ensure that we are not using the
-                    // `#[rustc_layout_scalar_valid_range(n)]`
-                    // attribute to widen the range of anything as that would probably
-                    // result in UB somewhere
-                    // FIXME(eddyb) the asserts are probably not needed,
-                    // as larger validity ranges would result in missed
-                    // optimizations, *not* wrongly assuming the inner
-                    // value is valid. e.g. unions enlarge validity ranges,
-                    // because the values may be uninitialized.
-                    if let Bound::Included(start) = start {
-                        // FIXME(eddyb) this might be incorrect - it doesn't
-                        // account for wrap-around (end < start) ranges.
-                        let valid_range = scalar.valid_range_mut();
-                        assert!(valid_range.start <= start);
-                        valid_range.start = start;
-                    }
-                    if let Bound::Included(end) = end {
-                        // FIXME(eddyb) this might be incorrect - it doesn't
-                        // account for wrap-around (end < start) ranges.
-                        let valid_range = scalar.valid_range_mut();
-                        assert!(valid_range.end >= end);
-                        valid_range.end = end;
-                    }
-
-                    // Update `largest_niche` if we have introduced a larger niche.
-                    let niche = Niche::from_scalar(dl, Size::ZERO, *scalar);
-                    if let Some(niche) = niche {
-                        match st.largest_niche {
-                            Some(largest_niche) => {
-                                // Replace the existing niche even if they're equal,
-                                // because this one is at a lower offset.
-                                if largest_niche.available(dl) <= niche.available(dl) {
-                                    st.largest_niche = Some(niche);
-                                }
-                            }
-                            None => st.largest_niche = Some(niche),
-                        }
-                    }
-                }
-                _ => assert!(
-                    start == Bound::Unbounded && end == Bound::Unbounded,
-                    "nonscalar layout for layout_scalar_valid_range type: {:#?}",
-                    st,
-                ),
-            }
-
-            return Some(st);
-        }
-
-        // At this point, we have handled all unions and
-        // structs. (We have also handled univariant enums
-        // that allow representation optimization.)
-        assert!(is_enum);
-
-        // Until we've decided whether to use the tagged or
-        // niche filling LayoutS, we don't want to intern the
-        // variant layouts, so we can't store them in the
-        // overall LayoutS. Store the overall LayoutS
-        // and the variant LayoutSs here until then.
-        struct TmpLayout<V: Idx> {
-            layout: LayoutS<V>,
-            variants: IndexVec<V, LayoutS<V>>,
-        }
-
-        let calculate_niche_filling_layout = || -> Option<TmpLayout<V>> {
-            if niche_optimize_enum {
-                return None;
-            }
-
-            if variants.len() < 2 {
-                return None;
-            }
-
-            let mut align = dl.aggregate_align;
-            let mut variant_layouts = variants
-                .iter_enumerated()
-                .map(|(j, v)| {
-                    let mut st = self.univariant(dl, v, &repr, StructKind::AlwaysSized)?;
-                    st.variants = Variants::Single { index: j };
-
-                    align = align.max(st.align);
-
-                    Some(st)
-                })
-                .collect::<Option<IndexVec<V, _>>>()?;
-
-            let largest_variant_index = variant_layouts
-                .iter_enumerated()
-                .max_by_key(|(_i, layout)| layout.size.bytes())
-                .map(|(i, _layout)| i)?;
-
-            let all_indices = (0..=variants.len() - 1).map(V::new);
-            let needs_disc = |index: V| index != largest_variant_index && !absent(&variants[index]);
-            let niche_variants = all_indices.clone().find(|v| needs_disc(*v)).unwrap().index()
-                ..=all_indices.rev().find(|v| needs_disc(*v)).unwrap().index();
-
-            let count = niche_variants.size_hint().1.unwrap() as u128;
-
-            // Find the field with the largest niche
-            let (field_index, niche, (niche_start, niche_scalar)) = variants[largest_variant_index]
-                .iter()
-                .enumerate()
-                .filter_map(|(j, field)| Some((j, field.largest_niche?)))
-                .max_by_key(|(_, niche)| niche.available(dl))
-                .and_then(|(j, niche)| Some((j, niche, niche.reserve(dl, count)?)))?;
-            let niche_offset =
-                niche.offset + variant_layouts[largest_variant_index].fields.offset(field_index);
-            let niche_size = niche.value.size(dl);
-            let size = variant_layouts[largest_variant_index].size.align_to(align.abi);
-
-            let all_variants_fit = variant_layouts.iter_enumerated_mut().all(|(i, layout)| {
-                if i == largest_variant_index {
-                    return true;
-                }
-
-                layout.largest_niche = None;
-
-                if layout.size <= niche_offset {
-                    // This variant will fit before the niche.
-                    return true;
-                }
-
-                // Determine if it'll fit after the niche.
-                let this_align = layout.align.abi;
-                let this_offset = (niche_offset + niche_size).align_to(this_align);
-
-                if this_offset + layout.size > size {
-                    return false;
-                }
-
-                // It'll fit, but we need to make some adjustments.
-                match layout.fields {
-                    FieldsShape::Arbitrary { ref mut offsets, .. } => {
-                        for (j, offset) in offsets.iter_mut().enumerate() {
-                            if !variants[i][j].is_zst() {
-                                *offset += this_offset;
-                            }
-                        }
-                    }
-                    _ => {
-                        panic!("Layout of fields should be Arbitrary for variants")
-                    }
-                }
-
-                // It can't be a Scalar or ScalarPair because the offset isn't 0.
-                if !layout.abi.is_uninhabited() {
-                    layout.abi = Abi::Aggregate { sized: true };
-                }
-                layout.size += this_offset;
-
-                true
-            });
-
-            if !all_variants_fit {
-                return None;
-            }
-
-            let largest_niche = Niche::from_scalar(dl, niche_offset, niche_scalar);
-
-            let others_zst = variant_layouts
-                .iter_enumerated()
-                .all(|(i, layout)| i == largest_variant_index || layout.size == Size::ZERO);
-            let same_size = size == variant_layouts[largest_variant_index].size;
-            let same_align = align == variant_layouts[largest_variant_index].align;
-
-            let abi = if variant_layouts.iter().all(|v| v.abi.is_uninhabited()) {
-                Abi::Uninhabited
-            } else if same_size && same_align && others_zst {
-                match variant_layouts[largest_variant_index].abi {
-                    // When the total alignment and size match, we can use the
-                    // same ABI as the scalar variant with the reserved niche.
-                    Abi::Scalar(_) => Abi::Scalar(niche_scalar),
-                    Abi::ScalarPair(first, second) => {
-                        // Only the niche is guaranteed to be initialised,
-                        // so use union layouts for the other primitive.
-                        if niche_offset == Size::ZERO {
-                            Abi::ScalarPair(niche_scalar, second.to_union())
-                        } else {
-                            Abi::ScalarPair(first.to_union(), niche_scalar)
-                        }
-                    }
-                    _ => Abi::Aggregate { sized: true },
-                }
-            } else {
-                Abi::Aggregate { sized: true }
-            };
-
-            let layout = LayoutS {
-                variants: Variants::Multiple {
-                    tag: niche_scalar,
-                    tag_encoding: TagEncoding::Niche {
-                        untagged_variant: largest_variant_index,
-                        niche_variants: (V::new(*niche_variants.start())
-                            ..=V::new(*niche_variants.end())),
-                        niche_start,
-                    },
-                    tag_field: 0,
-                    variants: IndexVec::new(),
-                },
-                fields: FieldsShape::Arbitrary {
-                    offsets: vec![niche_offset],
-                    memory_index: vec![0],
-                },
-                abi,
-                largest_niche,
-                size,
-                align,
-            };
-
-            Some(TmpLayout { layout, variants: variant_layouts })
-        };
-
-        let niche_filling_layout = calculate_niche_filling_layout();
-
-        let (mut min, mut max) = (i128::MAX, i128::MIN);
-        let discr_type = repr.discr_type();
-        let bits = Integer::from_attr(dl, discr_type).size().bits();
-        for (i, mut val) in discriminants {
-            if variants[i].iter().any(|f| f.abi.is_uninhabited()) {
-                continue;
-            }
-            if discr_type.is_signed() {
-                // sign extend the raw representation to be an i128
-                val = (val << (128 - bits)) >> (128 - bits);
-            }
-            if val < min {
-                min = val;
-            }
-            if val > max {
-                max = val;
-            }
-        }
-        // We might have no inhabited variants, so pretend there's at least one.
-        if (min, max) == (i128::MAX, i128::MIN) {
-            min = 0;
-            max = 0;
-        }
-        assert!(min <= max, "discriminant range is {}...{}", min, max);
-        let (min_ity, signed) = discr_range_of_repr(min, max); //Integer::repr_discr(tcx, ty, &repr, min, max);
-
-        let mut align = dl.aggregate_align;
-        let mut size = Size::ZERO;
-
-        // We're interested in the smallest alignment, so start large.
-        let mut start_align = Align::from_bytes(256).unwrap();
-        assert_eq!(Integer::for_align(dl, start_align), None);
-
-        // repr(C) on an enum tells us to make a (tag, union) layout,
-        // so we need to grow the prefix alignment to be at least
-        // the alignment of the union. (This value is used both for
-        // determining the alignment of the overall enum, and the
-        // determining the alignment of the payload after the tag.)
-        let mut prefix_align = min_ity.align(dl).abi;
-        if repr.c() {
-            for fields in variants {
-                for field in fields {
-                    prefix_align = prefix_align.max(field.align.abi);
-                }
-            }
-        }
-
-        // Create the set of structs that represent each variant.
-        let mut layout_variants = variants
-            .iter_enumerated()
-            .map(|(i, field_layouts)| {
-                let mut st = self.univariant(
-                    dl,
-                    &field_layouts,
-                    &repr,
-                    StructKind::Prefixed(min_ity.size(), prefix_align),
-                )?;
-                st.variants = Variants::Single { index: i };
-                // Find the first field we can't move later
-                // to make room for a larger discriminant.
-                for field in st.fields.index_by_increasing_offset().map(|j| &field_layouts[j]) {
-                    if !field.is_zst() || field.align.abi.bytes() != 1 {
-                        start_align = start_align.min(field.align.abi);
-                        break;
-                    }
-                }
-                size = cmp::max(size, st.size);
-                align = align.max(st.align);
-                Some(st)
-            })
-            .collect::<Option<IndexVec<V, _>>>()?;
-
-        // Align the maximum variant size to the largest alignment.
-        size = size.align_to(align.abi);
-
-        if size.bytes() >= dl.obj_size_bound() {
-            return None;
-        }
-
-        let typeck_ity = Integer::from_attr(dl, repr.discr_type());
-        if typeck_ity < min_ity {
-            // It is a bug if Layout decided on a greater discriminant size than typeck for
-            // some reason at this point (based on values discriminant can take on). Mostly
-            // because this discriminant will be loaded, and then stored into variable of
-            // type calculated by typeck. Consider such case (a bug): typeck decided on
-            // byte-sized discriminant, but layout thinks we need a 16-bit to store all
-            // discriminant values. That would be a bug, because then, in codegen, in order
-            // to store this 16-bit discriminant into 8-bit sized temporary some of the
-            // space necessary to represent would have to be discarded (or layout is wrong
-            // on thinking it needs 16 bits)
-            panic!(
-                "layout decided on a larger discriminant type ({:?}) than typeck ({:?})",
-                min_ity, typeck_ity
-            );
-            // However, it is fine to make discr type however large (as an optimisation)
-            // after this point – we’ll just truncate the value we load in codegen.
-        }
-
-        // Check to see if we should use a different type for the
-        // discriminant. We can safely use a type with the same size
-        // as the alignment of the first field of each variant.
-        // We increase the size of the discriminant to avoid LLVM copying
-        // padding when it doesn't need to. This normally causes unaligned
-        // load/stores and excessive memcpy/memset operations. By using a
-        // bigger integer size, LLVM can be sure about its contents and
-        // won't be so conservative.
-
-        // Use the initial field alignment
-        let mut ity = if repr.c() || repr.int.is_some() {
-            min_ity
-        } else {
-            Integer::for_align(dl, start_align).unwrap_or(min_ity)
-        };
-
-        // If the alignment is not larger than the chosen discriminant size,
-        // don't use the alignment as the final size.
-        if ity <= min_ity {
-            ity = min_ity;
-        } else {
-            // Patch up the variants' first few fields.
-            let old_ity_size = min_ity.size();
-            let new_ity_size = ity.size();
-            for variant in &mut layout_variants {
-                match variant.fields {
-                    FieldsShape::Arbitrary { ref mut offsets, .. } => {
-                        for i in offsets {
-                            if *i <= old_ity_size {
-                                assert_eq!(*i, old_ity_size);
-                                *i = new_ity_size;
-                            }
-                        }
-                        // We might be making the struct larger.
-                        if variant.size <= old_ity_size {
-                            variant.size = new_ity_size;
-                        }
-                    }
-                    _ => panic!(),
-                }
-            }
-        }
-
-        let tag_mask = ity.size().unsigned_int_max();
-        let tag = Scalar::Initialized {
-            value: Int(ity, signed),
-            valid_range: WrappingRange {
-                start: (min as u128 & tag_mask),
-                end: (max as u128 & tag_mask),
-            },
-        };
-        let mut abi = Abi::Aggregate { sized: true };
-
-        if layout_variants.iter().all(|v| v.abi.is_uninhabited()) {
-            abi = Abi::Uninhabited;
-        } else if tag.size(dl) == size {
-            // Make sure we only use scalar layout when the enum is entirely its
-            // own tag (i.e. it has no padding nor any non-ZST variant fields).
-            abi = Abi::Scalar(tag);
-        } else {
-            // Try to use a ScalarPair for all tagged enums.
-            let mut common_prim = None;
-            let mut common_prim_initialized_in_all_variants = true;
-            for (field_layouts, layout_variant) in iter::zip(&*variants, &layout_variants) {
-                let FieldsShape::Arbitrary { ref offsets, .. } = layout_variant.fields else {
-                    panic!();
-                };
-                let mut fields = iter::zip(field_layouts, offsets).filter(|p| !p.0.is_zst());
-                let (field, offset) = match (fields.next(), fields.next()) {
-                    (None, None) => {
-                        common_prim_initialized_in_all_variants = false;
-                        continue;
-                    }
-                    (Some(pair), None) => pair,
-                    _ => {
-                        common_prim = None;
-                        break;
-                    }
-                };
-                let prim = match field.abi {
-                    Abi::Scalar(scalar) => {
-                        common_prim_initialized_in_all_variants &=
-                            matches!(scalar, Scalar::Initialized { .. });
-                        scalar.primitive()
-                    }
-                    _ => {
-                        common_prim = None;
-                        break;
-                    }
-                };
-                if let Some(pair) = common_prim {
-                    // This is pretty conservative. We could go fancier
-                    // by conflating things like i32 and u32, or even
-                    // realising that (u8, u8) could just cohabit with
-                    // u16 or even u32.
-                    if pair != (prim, offset) {
-                        common_prim = None;
-                        break;
-                    }
-                } else {
-                    common_prim = Some((prim, offset));
-                }
-            }
-            if let Some((prim, offset)) = common_prim {
-                let prim_scalar = if common_prim_initialized_in_all_variants {
-                    scalar_unit(prim)
-                } else {
-                    // Common prim might be uninit.
-                    Scalar::Union { value: prim }
-                };
-                let pair = self.scalar_pair::<V>(tag, prim_scalar);
-                let pair_offsets = match pair.fields {
-                    FieldsShape::Arbitrary { ref offsets, ref memory_index } => {
-                        assert_eq!(memory_index, &[0, 1]);
-                        offsets
-                    }
-                    _ => panic!(),
-                };
-                if pair_offsets[0] == Size::ZERO
-                    && pair_offsets[1] == *offset
-                    && align == pair.align
-                    && size == pair.size
-                {
-                    // We can use `ScalarPair` only when it matches our
-                    // already computed layout (including `#[repr(C)]`).
-                    abi = pair.abi;
-                }
-            }
-        }
-
-        // If we pick a "clever" (by-value) ABI, we might have to adjust the ABI of the
-        // variants to ensure they are consistent. This is because a downcast is
-        // semantically a NOP, and thus should not affect layout.
-        if matches!(abi, Abi::Scalar(..) | Abi::ScalarPair(..)) {
-            for variant in &mut layout_variants {
-                // We only do this for variants with fields; the others are not accessed anyway.
-                // Also do not overwrite any already existing "clever" ABIs.
-                if variant.fields.count() > 0 && matches!(variant.abi, Abi::Aggregate { .. }) {
-                    variant.abi = abi;
-                    // Also need to bump up the size and alignment, so that the entire value fits in here.
-                    variant.size = cmp::max(variant.size, size);
-                    variant.align.abi = cmp::max(variant.align.abi, align.abi);
-                }
-            }
-        }
-
-        let largest_niche = Niche::from_scalar(dl, Size::ZERO, tag);
-
-        let tagged_layout = LayoutS {
-            variants: Variants::Multiple {
-                tag,
-                tag_encoding: TagEncoding::Direct,
-                tag_field: 0,
-                variants: IndexVec::new(),
-            },
-            fields: FieldsShape::Arbitrary { offsets: vec![Size::ZERO], memory_index: vec![0] },
-            largest_niche,
-            abi,
-            align,
-            size,
-        };
-
-        let tagged_layout = TmpLayout { layout: tagged_layout, variants: layout_variants };
-
-        let mut best_layout = match (tagged_layout, niche_filling_layout) {
-            (tl, Some(nl)) => {
-                // Pick the smaller layout; otherwise,
-                // pick the layout with the larger niche; otherwise,
-                // pick tagged as it has simpler codegen.
-                use cmp::Ordering::*;
-                let niche_size = |tmp_l: &TmpLayout<V>| {
-                    tmp_l.layout.largest_niche.map_or(0, |n| n.available(dl))
-                };
-                match (tl.layout.size.cmp(&nl.layout.size), niche_size(&tl).cmp(&niche_size(&nl))) {
-                    (Greater, _) => nl,
-                    (Equal, Less) => nl,
-                    _ => tl,
-                }
-            }
-            (tl, None) => tl,
-        };
-
-        // Now we can intern the variant layouts and store them in the enum layout.
-        best_layout.layout.variants = match best_layout.layout.variants {
-            Variants::Multiple { tag, tag_encoding, tag_field, .. } => {
-                Variants::Multiple { tag, tag_encoding, tag_field, variants: best_layout.variants }
-            }
-            _ => panic!(),
-        };
-        Some(best_layout.layout)
-    }
-
-    fn layout_of_union<'a, V: Idx, F: Deref<Target = &'a LayoutS<V>> + Debug>(
-        &self,
-        repr: &ReprOptions,
-        variants: &IndexVec<V, Vec<F>>,
-    ) -> Option<LayoutS<V>> {
-        let dl = self.current_data_layout();
-        let dl = dl.borrow();
-        let mut align = if repr.pack.is_some() { dl.i8_align } else { dl.aggregate_align };
-
-        if let Some(repr_align) = repr.align {
-            align = align.max(AbiAndPrefAlign::new(repr_align));
-        }
-
-        let optimize = !repr.inhibit_union_abi_opt();
-        let mut size = Size::ZERO;
-        let mut abi = Abi::Aggregate { sized: true };
-        let index = V::new(0);
-        for field in &variants[index] {
-            assert!(!field.is_unsized());
-            align = align.max(field.align);
-
-            // If all non-ZST fields have the same ABI, forward this ABI
-            if optimize && !field.is_zst() {
-                // Discard valid range information and allow undef
-                let field_abi = match field.abi {
-                    Abi::Scalar(x) => Abi::Scalar(x.to_union()),
-                    Abi::ScalarPair(x, y) => Abi::ScalarPair(x.to_union(), y.to_union()),
-                    Abi::Vector { element: x, count } => {
-                        Abi::Vector { element: x.to_union(), count }
-                    }
-                    Abi::Uninhabited | Abi::Aggregate { .. } => Abi::Aggregate { sized: true },
-                };
-
-                if size == Size::ZERO {
-                    // first non ZST: initialize 'abi'
-                    abi = field_abi;
-                } else if abi != field_abi {
-                    // different fields have different ABI: reset to Aggregate
-                    abi = Abi::Aggregate { sized: true };
-                }
-            }
-
-            size = cmp::max(size, field.size);
-        }
-
-        if let Some(pack) = repr.pack {
-            align = align.min(AbiAndPrefAlign::new(pack));
-        }
-
-        Some(LayoutS {
-            variants: Variants::Single { index },
-            fields: FieldsShape::Union(NonZeroUsize::new(variants[index].len())?),
-            abi,
-            largest_niche: None,
-            align,
-            size: size.align_to(align.abi),
-        })
-    }
-}
diff --git a/compiler/rustc_target/src/abi/mod.rs b/compiler/rustc_target/src/abi/mod.rs
index b6972d914a0..53c9878ab87 100644
--- a/compiler/rustc_target/src/abi/mod.rs
+++ b/compiler/rustc_target/src/abi/mod.rs
@@ -2,413 +2,16 @@ pub use Integer::*;
 pub use Primitive::*;
 
 use crate::json::{Json, ToJson};
-#[cfg(feature = "nightly")]
-use crate::spec::Target;
 
-use std::convert::{TryFrom, TryInto};
 use std::fmt;
-#[cfg(feature = "nightly")]
-use std::iter::Step;
-use std::num::{NonZeroUsize, ParseIntError};
-use std::ops::{Add, AddAssign, Deref, Mul, RangeInclusive, Sub};
-use std::str::FromStr;
+use std::ops::Deref;
 
-use bitflags::bitflags;
-#[cfg(feature = "nightly")]
 use rustc_data_structures::intern::Interned;
-use rustc_index::vec::{Idx, IndexVec};
-#[cfg(feature = "nightly")]
 use rustc_macros::HashStable_Generic;
 
-#[cfg(feature = "nightly")]
 pub mod call;
 
-mod layout;
-
-pub use layout::LayoutCalculator;
-
-bitflags! {
-    #[derive(Default)]
-    #[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))]
-    pub struct ReprFlags: u8 {
-        const IS_C               = 1 << 0;
-        const IS_SIMD            = 1 << 1;
-        const IS_TRANSPARENT     = 1 << 2;
-        // Internal only for now. If true, don't reorder fields.
-        const IS_LINEAR          = 1 << 3;
-        // If true, the type's layout can be randomized using
-        // the seed stored in `ReprOptions.layout_seed`
-        const RANDOMIZE_LAYOUT   = 1 << 4;
-        // Any of these flags being set prevent field reordering optimisation.
-        const IS_UNOPTIMISABLE   = ReprFlags::IS_C.bits
-                                 | ReprFlags::IS_SIMD.bits
-                                 | ReprFlags::IS_LINEAR.bits;
-    }
-}
-
-#[derive(Copy, Clone, Debug, Eq, PartialEq)]
-#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))]
-pub enum IntegerType {
-    Pointer(bool),
-    Fixed(Integer, bool),
-}
-
-impl IntegerType {
-    pub fn is_signed(&self) -> bool {
-        match self {
-            IntegerType::Pointer(b) => *b,
-            IntegerType::Fixed(_, b) => *b,
-        }
-    }
-}
-
-/// Represents the repr options provided by the user,
-#[derive(Copy, Clone, Debug, Eq, PartialEq, Default)]
-#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))]
-pub struct ReprOptions {
-    pub int: Option<IntegerType>,
-    pub align: Option<Align>,
-    pub pack: Option<Align>,
-    pub flags: ReprFlags,
-    /// The seed to be used for randomizing a type's layout
-    ///
-    /// Note: This could technically be a `[u8; 16]` (a `u128`) which would
-    /// be the "most accurate" hash as it'd encompass the item and crate
-    /// hash without loss, but it does pay the price of being larger.
-    /// Everything's a tradeoff, a `u64` seed should be sufficient for our
-    /// purposes (primarily `-Z randomize-layout`)
-    pub field_shuffle_seed: u64,
-}
-
-impl ReprOptions {
-    #[inline]
-    pub fn simd(&self) -> bool {
-        self.flags.contains(ReprFlags::IS_SIMD)
-    }
-
-    #[inline]
-    pub fn c(&self) -> bool {
-        self.flags.contains(ReprFlags::IS_C)
-    }
-
-    #[inline]
-    pub fn packed(&self) -> bool {
-        self.pack.is_some()
-    }
-
-    #[inline]
-    pub fn transparent(&self) -> bool {
-        self.flags.contains(ReprFlags::IS_TRANSPARENT)
-    }
-
-    #[inline]
-    pub fn linear(&self) -> bool {
-        self.flags.contains(ReprFlags::IS_LINEAR)
-    }
-
-    /// Returns the discriminant type, given these `repr` options.
-    /// This must only be called on enums!
-    pub fn discr_type(&self) -> IntegerType {
-        self.int.unwrap_or(IntegerType::Pointer(true))
-    }
-
-    /// Returns `true` if this `#[repr()]` should inhabit "smart enum
-    /// layout" optimizations, such as representing `Foo<&T>` as a
-    /// single pointer.
-    pub fn inhibit_enum_layout_opt(&self) -> bool {
-        self.c() || self.int.is_some()
-    }
-
-    /// Returns `true` if this `#[repr()]` should inhibit struct field reordering
-    /// optimizations, such as with `repr(C)`, `repr(packed(1))`, or `repr(<int>)`.
-    pub fn inhibit_struct_field_reordering_opt(&self) -> bool {
-        if let Some(pack) = self.pack {
-            if pack.bytes() == 1 {
-                return true;
-            }
-        }
-
-        self.flags.intersects(ReprFlags::IS_UNOPTIMISABLE) || self.int.is_some()
-    }
-
-    /// Returns `true` if this type is valid for reordering and `-Z randomize-layout`
-    /// was enabled for its declaration crate
-    pub fn can_randomize_type_layout(&self) -> bool {
-        !self.inhibit_struct_field_reordering_opt()
-            && self.flags.contains(ReprFlags::RANDOMIZE_LAYOUT)
-    }
-
-    /// Returns `true` if this `#[repr()]` should inhibit union ABI optimisations.
-    pub fn inhibit_union_abi_opt(&self) -> bool {
-        self.c()
-    }
-}
-
-/// Parsed [Data layout](https://llvm.org/docs/LangRef.html#data-layout)
-/// for a target, which contains everything needed to compute layouts.
-#[derive(Debug, PartialEq, Eq)]
-pub struct TargetDataLayout {
-    pub endian: Endian,
-    pub i1_align: AbiAndPrefAlign,
-    pub i8_align: AbiAndPrefAlign,
-    pub i16_align: AbiAndPrefAlign,
-    pub i32_align: AbiAndPrefAlign,
-    pub i64_align: AbiAndPrefAlign,
-    pub i128_align: AbiAndPrefAlign,
-    pub f32_align: AbiAndPrefAlign,
-    pub f64_align: AbiAndPrefAlign,
-    pub pointer_size: Size,
-    pub pointer_align: AbiAndPrefAlign,
-    pub aggregate_align: AbiAndPrefAlign,
-
-    /// Alignments for vector types.
-    pub vector_align: Vec<(Size, AbiAndPrefAlign)>,
-
-    pub instruction_address_space: AddressSpace,
-
-    /// Minimum size of #[repr(C)] enums (default I32 bits)
-    pub c_enum_min_size: Integer,
-}
-
-impl Default for TargetDataLayout {
-    /// Creates an instance of `TargetDataLayout`.
-    fn default() -> TargetDataLayout {
-        let align = |bits| Align::from_bits(bits).unwrap();
-        TargetDataLayout {
-            endian: Endian::Big,
-            i1_align: AbiAndPrefAlign::new(align(8)),
-            i8_align: AbiAndPrefAlign::new(align(8)),
-            i16_align: AbiAndPrefAlign::new(align(16)),
-            i32_align: AbiAndPrefAlign::new(align(32)),
-            i64_align: AbiAndPrefAlign { abi: align(32), pref: align(64) },
-            i128_align: AbiAndPrefAlign { abi: align(32), pref: align(64) },
-            f32_align: AbiAndPrefAlign::new(align(32)),
-            f64_align: AbiAndPrefAlign::new(align(64)),
-            pointer_size: Size::from_bits(64),
-            pointer_align: AbiAndPrefAlign::new(align(64)),
-            aggregate_align: AbiAndPrefAlign { abi: align(0), pref: align(64) },
-            vector_align: vec![
-                (Size::from_bits(64), AbiAndPrefAlign::new(align(64))),
-                (Size::from_bits(128), AbiAndPrefAlign::new(align(128))),
-            ],
-            instruction_address_space: AddressSpace::DATA,
-            c_enum_min_size: Integer::I32,
-        }
-    }
-}
-
-pub enum TargetDataLayoutErrors<'a> {
-    InvalidAddressSpace { addr_space: &'a str, cause: &'a str, err: ParseIntError },
-    InvalidBits { kind: &'a str, bit: &'a str, cause: &'a str, err: ParseIntError },
-    MissingAlignment { cause: &'a str },
-    InvalidAlignment { cause: &'a str, err: String },
-    InconsistentTargetArchitecture { dl: &'a str, target: &'a str },
-    InconsistentTargetPointerWidth { pointer_size: u64, target: u32 },
-    InvalidBitsSize { err: String },
-}
-
-impl TargetDataLayout {
-    #[cfg(feature = "nightly")]
-    pub fn parse<'a>(target: &'a Target) -> Result<TargetDataLayout, TargetDataLayoutErrors<'a>> {
-        // Parse an address space index from a string.
-        let parse_address_space = |s: &'a str, cause: &'a str| {
-            s.parse::<u32>().map(AddressSpace).map_err(|err| {
-                TargetDataLayoutErrors::InvalidAddressSpace { addr_space: s, cause, err }
-            })
-        };
-
-        // Parse a bit count from a string.
-        let parse_bits = |s: &'a str, kind: &'a str, cause: &'a str| {
-            s.parse::<u64>().map_err(|err| TargetDataLayoutErrors::InvalidBits {
-                kind,
-                bit: s,
-                cause,
-                err,
-            })
-        };
-
-        // Parse a size string.
-        let size = |s: &'a str, cause: &'a str| parse_bits(s, "size", cause).map(Size::from_bits);
-
-        // Parse an alignment string.
-        let align = |s: &[&'a str], cause: &'a str| {
-            if s.is_empty() {
-                return Err(TargetDataLayoutErrors::MissingAlignment { cause });
-            }
-            let align_from_bits = |bits| {
-                Align::from_bits(bits)
-                    .map_err(|err| TargetDataLayoutErrors::InvalidAlignment { cause, err })
-            };
-            let abi = parse_bits(s[0], "alignment", cause)?;
-            let pref = s.get(1).map_or(Ok(abi), |pref| parse_bits(pref, "alignment", cause))?;
-            Ok(AbiAndPrefAlign { abi: align_from_bits(abi)?, pref: align_from_bits(pref)? })
-        };
-
-        let mut dl = TargetDataLayout::default();
-        let mut i128_align_src = 64;
-        for spec in target.data_layout.split('-') {
-            let spec_parts = spec.split(':').collect::<Vec<_>>();
-
-            match &*spec_parts {
-                ["e"] => dl.endian = Endian::Little,
-                ["E"] => dl.endian = Endian::Big,
-                [p] if p.starts_with('P') => {
-                    dl.instruction_address_space = parse_address_space(&p[1..], "P")?
-                }
-                ["a", ref a @ ..] => dl.aggregate_align = align(a, "a")?,
-                ["f32", ref a @ ..] => dl.f32_align = align(a, "f32")?,
-                ["f64", ref a @ ..] => dl.f64_align = align(a, "f64")?,
-                [p @ "p", s, ref a @ ..] | [p @ "p0", s, ref a @ ..] => {
-                    dl.pointer_size = size(s, p)?;
-                    dl.pointer_align = align(a, p)?;
-                }
-                [s, ref a @ ..] if s.starts_with('i') => {
-                    let Ok(bits) = s[1..].parse::<u64>() else {
-                        size(&s[1..], "i")?; // For the user error.
-                        continue;
-                    };
-                    let a = align(a, s)?;
-                    match bits {
-                        1 => dl.i1_align = a,
-                        8 => dl.i8_align = a,
-                        16 => dl.i16_align = a,
-                        32 => dl.i32_align = a,
-                        64 => dl.i64_align = a,
-                        _ => {}
-                    }
-                    if bits >= i128_align_src && bits <= 128 {
-                        // Default alignment for i128 is decided by taking the alignment of
-                        // largest-sized i{64..=128}.
-                        i128_align_src = bits;
-                        dl.i128_align = a;
-                    }
-                }
-                [s, ref a @ ..] if s.starts_with('v') => {
-                    let v_size = size(&s[1..], "v")?;
-                    let a = align(a, s)?;
-                    if let Some(v) = dl.vector_align.iter_mut().find(|v| v.0 == v_size) {
-                        v.1 = a;
-                        continue;
-                    }
-                    // No existing entry, add a new one.
-                    dl.vector_align.push((v_size, a));
-                }
-                _ => {} // Ignore everything else.
-            }
-        }
-
-        // Perform consistency checks against the Target information.
-        if dl.endian != target.endian {
-            return Err(TargetDataLayoutErrors::InconsistentTargetArchitecture {
-                dl: dl.endian.as_str(),
-                target: target.endian.as_str(),
-            });
-        }
-
-        let target_pointer_width: u64 = target.pointer_width.into();
-        if dl.pointer_size.bits() != target_pointer_width {
-            return Err(TargetDataLayoutErrors::InconsistentTargetPointerWidth {
-                pointer_size: dl.pointer_size.bits(),
-                target: target.pointer_width,
-            });
-        }
-
-        dl.c_enum_min_size = match Integer::from_size(Size::from_bits(target.c_enum_min_bits)) {
-            Ok(bits) => bits,
-            Err(err) => return Err(TargetDataLayoutErrors::InvalidBitsSize { err }),
-        };
-
-        Ok(dl)
-    }
-
-    /// Returns exclusive upper bound on object size.
-    ///
-    /// The theoretical maximum object size is defined as the maximum positive `isize` value.
-    /// This ensures that the `offset` semantics remain well-defined by allowing it to correctly
-    /// index every address within an object along with one byte past the end, along with allowing
-    /// `isize` to store the difference between any two pointers into an object.
-    ///
-    /// The upper bound on 64-bit currently needs to be lower because LLVM uses a 64-bit integer
-    /// to represent object size in bits. It would need to be 1 << 61 to account for this, but is
-    /// currently conservatively bounded to 1 << 47 as that is enough to cover the current usable
-    /// address space on 64-bit ARMv8 and x86_64.
-    #[inline]
-    pub fn obj_size_bound(&self) -> u64 {
-        match self.pointer_size.bits() {
-            16 => 1 << 15,
-            32 => 1 << 31,
-            64 => 1 << 47,
-            bits => panic!("obj_size_bound: unknown pointer bit size {}", bits),
-        }
-    }
-
-    #[inline]
-    pub fn ptr_sized_integer(&self) -> Integer {
-        match self.pointer_size.bits() {
-            16 => I16,
-            32 => I32,
-            64 => I64,
-            bits => panic!("ptr_sized_integer: unknown pointer bit size {}", bits),
-        }
-    }
-
-    #[inline]
-    pub fn vector_align(&self, vec_size: Size) -> AbiAndPrefAlign {
-        for &(size, align) in &self.vector_align {
-            if size == vec_size {
-                return align;
-            }
-        }
-        // Default to natural alignment, which is what LLVM does.
-        // That is, use the size, rounded up to a power of 2.
-        AbiAndPrefAlign::new(Align::from_bytes(vec_size.bytes().next_power_of_two()).unwrap())
-    }
-}
-
-pub trait HasDataLayout {
-    fn data_layout(&self) -> &TargetDataLayout;
-}
-
-impl HasDataLayout for TargetDataLayout {
-    #[inline]
-    fn data_layout(&self) -> &TargetDataLayout {
-        self
-    }
-}
-
-/// Endianness of the target, which must match cfg(target-endian).
-#[derive(Copy, Clone, PartialEq, Eq)]
-pub enum Endian {
-    Little,
-    Big,
-}
-
-impl Endian {
-    pub fn as_str(&self) -> &'static str {
-        match self {
-            Self::Little => "little",
-            Self::Big => "big",
-        }
-    }
-}
-
-impl fmt::Debug for Endian {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.write_str(self.as_str())
-    }
-}
-
-impl FromStr for Endian {
-    type Err = String;
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        match s {
-            "little" => Ok(Self::Little),
-            "big" => Ok(Self::Big),
-            _ => Err(format!(r#"unknown endian: "{}""#, s)),
-        }
-    }
-}
+pub use rustc_abi::*;
 
 impl ToJson for Endian {
     fn to_json(&self) -> Json {
@@ -416,1082 +19,16 @@ impl ToJson for Endian {
     }
 }
 
-/// Size of a type in bytes.
-#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))]
-pub struct Size {
-    raw: u64,
-}
-
-// This is debug-printed a lot in larger structs, don't waste too much space there
-impl fmt::Debug for Size {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "Size({} bytes)", self.bytes())
-    }
-}
-
-impl Size {
-    pub const ZERO: Size = Size { raw: 0 };
-
-    /// Rounds `bits` up to the next-higher byte boundary, if `bits` is
-    /// not a multiple of 8.
-    pub fn from_bits(bits: impl TryInto<u64>) -> Size {
-        let bits = bits.try_into().ok().unwrap();
-        // Avoid potential overflow from `bits + 7`.
-        Size { raw: bits / 8 + ((bits % 8) + 7) / 8 }
-    }
-
-    #[inline]
-    pub fn from_bytes(bytes: impl TryInto<u64>) -> Size {
-        let bytes: u64 = bytes.try_into().ok().unwrap();
-        Size { raw: bytes }
-    }
-
-    #[inline]
-    pub fn bytes(self) -> u64 {
-        self.raw
-    }
-
-    #[inline]
-    pub fn bytes_usize(self) -> usize {
-        self.bytes().try_into().unwrap()
-    }
-
-    #[inline]
-    pub fn bits(self) -> u64 {
-        #[cold]
-        fn overflow(bytes: u64) -> ! {
-            panic!("Size::bits: {} bytes in bits doesn't fit in u64", bytes)
-        }
-
-        self.bytes().checked_mul(8).unwrap_or_else(|| overflow(self.bytes()))
-    }
-
-    #[inline]
-    pub fn bits_usize(self) -> usize {
-        self.bits().try_into().unwrap()
-    }
-
-    #[inline]
-    pub fn align_to(self, align: Align) -> Size {
-        let mask = align.bytes() - 1;
-        Size::from_bytes((self.bytes() + mask) & !mask)
-    }
-
-    #[inline]
-    pub fn is_aligned(self, align: Align) -> bool {
-        let mask = align.bytes() - 1;
-        self.bytes() & mask == 0
-    }
-
-    #[inline]
-    pub fn checked_add<C: HasDataLayout>(self, offset: Size, cx: &C) -> Option<Size> {
-        let dl = cx.data_layout();
-
-        let bytes = self.bytes().checked_add(offset.bytes())?;
-
-        if bytes < dl.obj_size_bound() { Some(Size::from_bytes(bytes)) } else { None }
-    }
-
-    #[inline]
-    pub fn checked_mul<C: HasDataLayout>(self, count: u64, cx: &C) -> Option<Size> {
-        let dl = cx.data_layout();
-
-        let bytes = self.bytes().checked_mul(count)?;
-        if bytes < dl.obj_size_bound() { Some(Size::from_bytes(bytes)) } else { None }
-    }
-
-    /// Truncates `value` to `self` bits and then sign-extends it to 128 bits
-    /// (i.e., if it is negative, fill with 1's on the left).
-    #[inline]
-    pub fn sign_extend(self, value: u128) -> u128 {
-        let size = self.bits();
-        if size == 0 {
-            // Truncated until nothing is left.
-            return 0;
-        }
-        // Sign-extend it.
-        let shift = 128 - size;
-        // Shift the unsigned value to the left, then shift back to the right as signed
-        // (essentially fills with sign bit on the left).
-        (((value << shift) as i128) >> shift) as u128
-    }
-
-    /// Truncates `value` to `self` bits.
-    #[inline]
-    pub fn truncate(self, value: u128) -> u128 {
-        let size = self.bits();
-        if size == 0 {
-            // Truncated until nothing is left.
-            return 0;
-        }
-        let shift = 128 - size;
-        // Truncate (shift left to drop out leftover values, shift right to fill with zeroes).
-        (value << shift) >> shift
-    }
-
-    #[inline]
-    pub fn signed_int_min(&self) -> i128 {
-        self.sign_extend(1_u128 << (self.bits() - 1)) as i128
-    }
-
-    #[inline]
-    pub fn signed_int_max(&self) -> i128 {
-        i128::MAX >> (128 - self.bits())
-    }
-
-    #[inline]
-    pub fn unsigned_int_max(&self) -> u128 {
-        u128::MAX >> (128 - self.bits())
-    }
-}
-
-// Panicking addition, subtraction and multiplication for convenience.
-// Avoid during layout computation, return `LayoutError` instead.
-
-impl Add for Size {
-    type Output = Size;
-    #[inline]
-    fn add(self, other: Size) -> Size {
-        Size::from_bytes(self.bytes().checked_add(other.bytes()).unwrap_or_else(|| {
-            panic!("Size::add: {} + {} doesn't fit in u64", self.bytes(), other.bytes())
-        }))
-    }
-}
-
-impl Sub for Size {
-    type Output = Size;
-    #[inline]
-    fn sub(self, other: Size) -> Size {
-        Size::from_bytes(self.bytes().checked_sub(other.bytes()).unwrap_or_else(|| {
-            panic!("Size::sub: {} - {} would result in negative size", self.bytes(), other.bytes())
-        }))
-    }
-}
-
-impl Mul<Size> for u64 {
-    type Output = Size;
-    #[inline]
-    fn mul(self, size: Size) -> Size {
-        size * self
-    }
-}
-
-impl Mul<u64> for Size {
-    type Output = Size;
-    #[inline]
-    fn mul(self, count: u64) -> Size {
-        match self.bytes().checked_mul(count) {
-            Some(bytes) => Size::from_bytes(bytes),
-            None => panic!("Size::mul: {} * {} doesn't fit in u64", self.bytes(), count),
-        }
-    }
-}
-
-impl AddAssign for Size {
-    #[inline]
-    fn add_assign(&mut self, other: Size) {
-        *self = *self + other;
-    }
-}
-
-#[cfg(feature = "nightly")]
-impl Step for Size {
-    #[inline]
-    fn steps_between(start: &Self, end: &Self) -> Option<usize> {
-        u64::steps_between(&start.bytes(), &end.bytes())
-    }
-
-    #[inline]
-    fn forward_checked(start: Self, count: usize) -> Option<Self> {
-        u64::forward_checked(start.bytes(), count).map(Self::from_bytes)
-    }
-
-    #[inline]
-    fn forward(start: Self, count: usize) -> Self {
-        Self::from_bytes(u64::forward(start.bytes(), count))
-    }
-
-    #[inline]
-    unsafe fn forward_unchecked(start: Self, count: usize) -> Self {
-        Self::from_bytes(u64::forward_unchecked(start.bytes(), count))
-    }
-
-    #[inline]
-    fn backward_checked(start: Self, count: usize) -> Option<Self> {
-        u64::backward_checked(start.bytes(), count).map(Self::from_bytes)
-    }
-
-    #[inline]
-    fn backward(start: Self, count: usize) -> Self {
-        Self::from_bytes(u64::backward(start.bytes(), count))
-    }
-
-    #[inline]
-    unsafe fn backward_unchecked(start: Self, count: usize) -> Self {
-        Self::from_bytes(u64::backward_unchecked(start.bytes(), count))
-    }
-}
-
-/// Alignment of a type in bytes (always a power of two).
-#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))]
-pub struct Align {
-    pow2: u8,
-}
-
-// This is debug-printed a lot in larger structs, don't waste too much space there
-impl fmt::Debug for Align {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "Align({} bytes)", self.bytes())
-    }
-}
-
-impl Align {
-    pub const ONE: Align = Align { pow2: 0 };
-    pub const MAX: Align = Align { pow2: 29 };
-
-    #[inline]
-    pub fn from_bits(bits: u64) -> Result<Align, String> {
-        Align::from_bytes(Size::from_bits(bits).bytes())
-    }
-
-    #[inline]
-    pub fn from_bytes(align: u64) -> Result<Align, String> {
-        // Treat an alignment of 0 bytes like 1-byte alignment.
-        if align == 0 {
-            return Ok(Align::ONE);
-        }
-
-        #[cold]
-        fn not_power_of_2(align: u64) -> String {
-            format!("`{}` is not a power of 2", align)
-        }
-
-        #[cold]
-        fn too_large(align: u64) -> String {
-            format!("`{}` is too large", align)
-        }
-
-        let mut bytes = align;
-        let mut pow2: u8 = 0;
-        while (bytes & 1) == 0 {
-            pow2 += 1;
-            bytes >>= 1;
-        }
-        if bytes != 1 {
-            return Err(not_power_of_2(align));
-        }
-        if pow2 > Self::MAX.pow2 {
-            return Err(too_large(align));
-        }
-
-        Ok(Align { pow2 })
-    }
-
-    #[inline]
-    pub fn bytes(self) -> u64 {
-        1 << self.pow2
-    }
-
-    #[inline]
-    pub fn bits(self) -> u64 {
-        self.bytes() * 8
-    }
-
-    /// Computes the best alignment possible for the given offset
-    /// (the largest power of two that the offset is a multiple of).
-    ///
-    /// N.B., for an offset of `0`, this happens to return `2^64`.
-    #[inline]
-    pub fn max_for_offset(offset: Size) -> Align {
-        Align { pow2: offset.bytes().trailing_zeros() as u8 }
-    }
-
-    /// Lower the alignment, if necessary, such that the given offset
-    /// is aligned to it (the offset is a multiple of the alignment).
-    #[inline]
-    pub fn restrict_for_offset(self, offset: Size) -> Align {
-        self.min(Align::max_for_offset(offset))
-    }
-}
-
-/// A pair of alignments, ABI-mandated and preferred.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
-#[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
-
-pub struct AbiAndPrefAlign {
-    pub abi: Align,
-    pub pref: Align,
-}
-
-impl AbiAndPrefAlign {
-    #[inline]
-    pub fn new(align: Align) -> AbiAndPrefAlign {
-        AbiAndPrefAlign { abi: align, pref: align }
-    }
-
-    #[inline]
-    pub fn min(self, other: AbiAndPrefAlign) -> AbiAndPrefAlign {
-        AbiAndPrefAlign { abi: self.abi.min(other.abi), pref: self.pref.min(other.pref) }
-    }
-
-    #[inline]
-    pub fn max(self, other: AbiAndPrefAlign) -> AbiAndPrefAlign {
-        AbiAndPrefAlign { abi: self.abi.max(other.abi), pref: self.pref.max(other.pref) }
-    }
-}
-
-/// Integers, also used for enum discriminants.
-#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
-#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))]
-
-pub enum Integer {
-    I8,
-    I16,
-    I32,
-    I64,
-    I128,
-}
-
-impl Integer {
-    #[inline]
-    pub fn size(self) -> Size {
-        match self {
-            I8 => Size::from_bytes(1),
-            I16 => Size::from_bytes(2),
-            I32 => Size::from_bytes(4),
-            I64 => Size::from_bytes(8),
-            I128 => Size::from_bytes(16),
-        }
-    }
-
-    /// Gets the Integer type from an attr::IntType.
-    pub fn from_attr<C: HasDataLayout>(cx: &C, ity: IntegerType) -> Integer {
-        let dl = cx.data_layout();
-
-        match ity {
-            IntegerType::Pointer(_) => dl.ptr_sized_integer(),
-            IntegerType::Fixed(x, _) => x,
-        }
-    }
-
-    pub fn align<C: HasDataLayout>(self, cx: &C) -> AbiAndPrefAlign {
-        let dl = cx.data_layout();
-
-        match self {
-            I8 => dl.i8_align,
-            I16 => dl.i16_align,
-            I32 => dl.i32_align,
-            I64 => dl.i64_align,
-            I128 => dl.i128_align,
-        }
-    }
-
-    /// Finds the smallest Integer type which can represent the signed value.
-    #[inline]
-    pub fn fit_signed(x: i128) -> Integer {
-        match x {
-            -0x0000_0000_0000_0080..=0x0000_0000_0000_007f => I8,
-            -0x0000_0000_0000_8000..=0x0000_0000_0000_7fff => I16,
-            -0x0000_0000_8000_0000..=0x0000_0000_7fff_ffff => I32,
-            -0x8000_0000_0000_0000..=0x7fff_ffff_ffff_ffff => I64,
-            _ => I128,
-        }
-    }
-
-    /// Finds the smallest Integer type which can represent the unsigned value.
-    #[inline]
-    pub fn fit_unsigned(x: u128) -> Integer {
-        match x {
-            0..=0x0000_0000_0000_00ff => I8,
-            0..=0x0000_0000_0000_ffff => I16,
-            0..=0x0000_0000_ffff_ffff => I32,
-            0..=0xffff_ffff_ffff_ffff => I64,
-            _ => I128,
-        }
-    }
-
-    /// Finds the smallest integer with the given alignment.
-    pub fn for_align<C: HasDataLayout>(cx: &C, wanted: Align) -> Option<Integer> {
-        let dl = cx.data_layout();
-
-        for candidate in [I8, I16, I32, I64, I128] {
-            if wanted == candidate.align(dl).abi && wanted.bytes() == candidate.size().bytes() {
-                return Some(candidate);
-            }
-        }
-        None
-    }
-
-    /// Find the largest integer with the given alignment or less.
-    pub fn approximate_align<C: HasDataLayout>(cx: &C, wanted: Align) -> Integer {
-        let dl = cx.data_layout();
-
-        // FIXME(eddyb) maybe include I128 in the future, when it works everywhere.
-        for candidate in [I64, I32, I16] {
-            if wanted >= candidate.align(dl).abi && wanted.bytes() >= candidate.size().bytes() {
-                return candidate;
-            }
-        }
-        I8
-    }
-
-    // FIXME(eddyb) consolidate this and other methods that find the appropriate
-    // `Integer` given some requirements.
-    #[inline]
-    fn from_size(size: Size) -> Result<Self, String> {
-        match size.bits() {
-            8 => Ok(Integer::I8),
-            16 => Ok(Integer::I16),
-            32 => Ok(Integer::I32),
-            64 => Ok(Integer::I64),
-            128 => Ok(Integer::I128),
-            _ => Err(format!("rust does not support integers with {} bits", size.bits())),
-        }
-    }
-}
-
-/// Fundamental unit of memory access and layout.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
-#[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
-pub enum Primitive {
-    /// The `bool` is the signedness of the `Integer` type.
-    ///
-    /// One would think we would not care about such details this low down,
-    /// but some ABIs are described in terms of C types and ISAs where the
-    /// integer arithmetic is done on {sign,zero}-extended registers, e.g.
-    /// a negative integer passed by zero-extension will appear positive in
-    /// the callee, and most operations on it will produce the wrong values.
-    Int(Integer, bool),
-    F32,
-    F64,
-    Pointer,
-}
-
-impl Primitive {
-    pub fn size<C: HasDataLayout>(self, cx: &C) -> Size {
-        let dl = cx.data_layout();
-
-        match self {
-            Int(i, _) => i.size(),
-            F32 => Size::from_bits(32),
-            F64 => Size::from_bits(64),
-            Pointer => dl.pointer_size,
-        }
-    }
-
-    pub fn align<C: HasDataLayout>(self, cx: &C) -> AbiAndPrefAlign {
-        let dl = cx.data_layout();
-
-        match self {
-            Int(i, _) => i.align(dl),
-            F32 => dl.f32_align,
-            F64 => dl.f64_align,
-            Pointer => dl.pointer_align,
-        }
-    }
-
-    // FIXME(eddyb) remove, it's trivial thanks to `matches!`.
-    #[inline]
-    pub fn is_float(self) -> bool {
-        matches!(self, F32 | F64)
-    }
-
-    // FIXME(eddyb) remove, it's completely unused.
-    #[inline]
-    pub fn is_int(self) -> bool {
-        matches!(self, Int(..))
-    }
-
-    #[inline]
-    pub fn is_ptr(self) -> bool {
-        matches!(self, Pointer)
-    }
-}
-
-/// Inclusive wrap-around range of valid values, that is, if
-/// start > end, it represents `start..=MAX`,
-/// followed by `0..=end`.
-///
-/// That is, for an i8 primitive, a range of `254..=2` means following
-/// sequence:
-///
-///    254 (-2), 255 (-1), 0, 1, 2
-///
-/// This is intended specifically to mirror LLVM’s `!range` metadata semantics.
-#[derive(Clone, Copy, PartialEq, Eq, Hash)]
-#[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
-pub struct WrappingRange {
-    pub start: u128,
-    pub end: u128,
-}
-
-impl WrappingRange {
-    pub fn full(size: Size) -> Self {
-        Self { start: 0, end: size.unsigned_int_max() }
-    }
-
-    /// Returns `true` if `v` is contained in the range.
-    #[inline(always)]
-    pub fn contains(&self, v: u128) -> bool {
-        if self.start <= self.end {
-            self.start <= v && v <= self.end
-        } else {
-            self.start <= v || v <= self.end
-        }
-    }
-
-    /// Returns `self` with replaced `start`
-    #[inline(always)]
-    pub fn with_start(mut self, start: u128) -> Self {
-        self.start = start;
-        self
-    }
-
-    /// Returns `self` with replaced `end`
-    #[inline(always)]
-    pub fn with_end(mut self, end: u128) -> Self {
-        self.end = end;
-        self
-    }
-
-    /// Returns `true` if `size` completely fills the range.
-    #[inline]
-    pub fn is_full_for(&self, size: Size) -> bool {
-        let max_value = size.unsigned_int_max();
-        debug_assert!(self.start <= max_value && self.end <= max_value);
-        self.start == (self.end.wrapping_add(1) & max_value)
-    }
-}
-
-impl fmt::Debug for WrappingRange {
-    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
-        if self.start > self.end {
-            write!(fmt, "(..={}) | ({}..)", self.end, self.start)?;
-        } else {
-            write!(fmt, "{}..={}", self.start, self.end)?;
-        }
-        Ok(())
-    }
-}
-
-/// Information about one scalar component of a Rust type.
-#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
-#[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
-pub enum Scalar {
-    Initialized {
-        value: Primitive,
-
-        // FIXME(eddyb) always use the shortest range, e.g., by finding
-        // the largest space between two consecutive valid values and
-        // taking everything else as the (shortest) valid range.
-        valid_range: WrappingRange,
-    },
-    Union {
-        /// Even for unions, we need to use the correct registers for the kind of
-        /// values inside the union, so we keep the `Primitive` type around. We
-        /// also use it to compute the size of the scalar.
-        /// However, unions never have niches and even allow undef,
-        /// so there is no `valid_range`.
-        value: Primitive,
-    },
-}
-
-impl Scalar {
-    #[inline]
-    pub fn is_bool(&self) -> bool {
-        matches!(
-            self,
-            Scalar::Initialized {
-                value: Int(I8, false),
-                valid_range: WrappingRange { start: 0, end: 1 }
-            }
-        )
-    }
-
-    /// Get the primitive representation of this type, ignoring the valid range and whether the
-    /// value is allowed to be undefined (due to being a union).
-    pub fn primitive(&self) -> Primitive {
-        match *self {
-            Scalar::Initialized { value, .. } | Scalar::Union { value } => value,
-        }
-    }
-
-    pub fn align(self, cx: &impl HasDataLayout) -> AbiAndPrefAlign {
-        self.primitive().align(cx)
-    }
-
-    pub fn size(self, cx: &impl HasDataLayout) -> Size {
-        self.primitive().size(cx)
-    }
-
-    #[inline]
-    pub fn to_union(&self) -> Self {
-        Self::Union { value: self.primitive() }
-    }
-
-    #[inline]
-    pub fn valid_range(&self, cx: &impl HasDataLayout) -> WrappingRange {
-        match *self {
-            Scalar::Initialized { valid_range, .. } => valid_range,
-            Scalar::Union { value } => WrappingRange::full(value.size(cx)),
-        }
-    }
-
-    #[inline]
-    /// Allows the caller to mutate the valid range. This operation will panic if attempted on a union.
-    pub fn valid_range_mut(&mut self) -> &mut WrappingRange {
-        match self {
-            Scalar::Initialized { valid_range, .. } => valid_range,
-            Scalar::Union { .. } => panic!("cannot change the valid range of a union"),
-        }
-    }
-
-    /// Returns `true` if all possible numbers are valid, i.e `valid_range` covers the whole layout
-    #[inline]
-    pub fn is_always_valid<C: HasDataLayout>(&self, cx: &C) -> bool {
-        match *self {
-            Scalar::Initialized { valid_range, .. } => valid_range.is_full_for(self.size(cx)),
-            Scalar::Union { .. } => true,
-        }
-    }
-
-    /// Returns `true` if this type can be left uninit.
-    #[inline]
-    pub fn is_uninit_valid(&self) -> bool {
-        match *self {
-            Scalar::Initialized { .. } => false,
-            Scalar::Union { .. } => true,
-        }
-    }
-}
-
-/// Describes how the fields of a type are located in memory.
-#[derive(PartialEq, Eq, Hash, Clone, Debug)]
-#[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
-pub enum FieldsShape {
-    /// Scalar primitives and `!`, which never have fields.
-    Primitive,
-
-    /// All fields start at no offset. The `usize` is the field count.
-    Union(NonZeroUsize),
-
-    /// Array/vector-like placement, with all fields of identical types.
-    Array { stride: Size, count: u64 },
-
-    /// Struct-like placement, with precomputed offsets.
-    ///
-    /// Fields are guaranteed to not overlap, but note that gaps
-    /// before, between and after all the fields are NOT always
-    /// padding, and as such their contents may not be discarded.
-    /// For example, enum variants leave a gap at the start,
-    /// where the discriminant field in the enum layout goes.
-    Arbitrary {
-        /// Offsets for the first byte of each field,
-        /// ordered to match the source definition order.
-        /// This vector does not go in increasing order.
-        // FIXME(eddyb) use small vector optimization for the common case.
-        offsets: Vec<Size>,
-
-        /// Maps source order field indices to memory order indices,
-        /// depending on how the fields were reordered (if at all).
-        /// This is a permutation, with both the source order and the
-        /// memory order using the same (0..n) index ranges.
-        ///
-        /// Note that during computation of `memory_index`, sometimes
-        /// it is easier to operate on the inverse mapping (that is,
-        /// from memory order to source order), and that is usually
-        /// named `inverse_memory_index`.
-        ///
-        // FIXME(eddyb) build a better abstraction for permutations, if possible.
-        // FIXME(camlorn) also consider small vector  optimization here.
-        memory_index: Vec<u32>,
-    },
-}
-
-impl FieldsShape {
-    #[inline]
-    pub fn count(&self) -> usize {
-        match *self {
-            FieldsShape::Primitive => 0,
-            FieldsShape::Union(count) => count.get(),
-            FieldsShape::Array { count, .. } => count.try_into().unwrap(),
-            FieldsShape::Arbitrary { ref offsets, .. } => offsets.len(),
-        }
-    }
-
-    #[inline]
-    pub fn offset(&self, i: usize) -> Size {
-        match *self {
-            FieldsShape::Primitive => {
-                unreachable!("FieldsShape::offset: `Primitive`s have no fields")
-            }
-            FieldsShape::Union(count) => {
-                assert!(
-                    i < count.get(),
-                    "tried to access field {} of union with {} fields",
-                    i,
-                    count
-                );
-                Size::ZERO
-            }
-            FieldsShape::Array { stride, count } => {
-                let i = u64::try_from(i).unwrap();
-                assert!(i < count);
-                stride * i
-            }
-            FieldsShape::Arbitrary { ref offsets, .. } => offsets[i],
-        }
-    }
-
-    #[inline]
-    pub fn memory_index(&self, i: usize) -> usize {
-        match *self {
-            FieldsShape::Primitive => {
-                unreachable!("FieldsShape::memory_index: `Primitive`s have no fields")
-            }
-            FieldsShape::Union(_) | FieldsShape::Array { .. } => i,
-            FieldsShape::Arbitrary { ref memory_index, .. } => memory_index[i].try_into().unwrap(),
-        }
-    }
-
-    /// Gets source indices of the fields by increasing offsets.
-    #[inline]
-    pub fn index_by_increasing_offset<'a>(&'a self) -> impl Iterator<Item = usize> + 'a {
-        let mut inverse_small = [0u8; 64];
-        let mut inverse_big = vec![];
-        let use_small = self.count() <= inverse_small.len();
-
-        // We have to write this logic twice in order to keep the array small.
-        if let FieldsShape::Arbitrary { ref memory_index, .. } = *self {
-            if use_small {
-                for i in 0..self.count() {
-                    inverse_small[memory_index[i] as usize] = i as u8;
-                }
-            } else {
-                inverse_big = vec![0; self.count()];
-                for i in 0..self.count() {
-                    inverse_big[memory_index[i] as usize] = i as u32;
-                }
-            }
-        }
-
-        (0..self.count()).map(move |i| match *self {
-            FieldsShape::Primitive | FieldsShape::Union(_) | FieldsShape::Array { .. } => i,
-            FieldsShape::Arbitrary { .. } => {
-                if use_small {
-                    inverse_small[i] as usize
-                } else {
-                    inverse_big[i] as usize
-                }
-            }
-        })
-    }
-}
-
-/// An identifier that specifies the address space that some operation
-/// should operate on. Special address spaces have an effect on code generation,
-/// depending on the target and the address spaces it implements.
-#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
-pub struct AddressSpace(pub u32);
-
-impl AddressSpace {
-    /// The default address space, corresponding to data space.
-    pub const DATA: Self = AddressSpace(0);
-}
-
-/// Describes how values of the type are passed by target ABIs,
-/// in terms of categories of C types there are ABI rules for.
-#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
-#[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
-
-pub enum Abi {
-    Uninhabited,
-    Scalar(Scalar),
-    ScalarPair(Scalar, Scalar),
-    Vector {
-        element: Scalar,
-        count: u64,
-    },
-    Aggregate {
-        /// If true, the size is exact, otherwise it's only a lower bound.
-        sized: bool,
-    },
-}
-
-impl Abi {
-    /// Returns `true` if the layout corresponds to an unsized type.
-    #[inline]
-    pub fn is_unsized(&self) -> bool {
-        match *self {
-            Abi::Uninhabited | Abi::Scalar(_) | Abi::ScalarPair(..) | Abi::Vector { .. } => false,
-            Abi::Aggregate { sized } => !sized,
-        }
-    }
-
-    #[inline]
-    pub fn is_sized(&self) -> bool {
-        !self.is_unsized()
-    }
-
-    /// Returns `true` if this is a single signed integer scalar
-    #[inline]
-    pub fn is_signed(&self) -> bool {
-        match self {
-            Abi::Scalar(scal) => match scal.primitive() {
-                Primitive::Int(_, signed) => signed,
-                _ => false,
-            },
-            _ => panic!("`is_signed` on non-scalar ABI {:?}", self),
-        }
-    }
-
-    /// Returns `true` if this is an uninhabited type
-    #[inline]
-    pub fn is_uninhabited(&self) -> bool {
-        matches!(*self, Abi::Uninhabited)
-    }
-
-    /// Returns `true` is this is a scalar type
-    #[inline]
-    pub fn is_scalar(&self) -> bool {
-        matches!(*self, Abi::Scalar(_))
-    }
-}
-
-#[cfg(feature = "nightly")]
 rustc_index::newtype_index! {
     pub struct VariantIdx {
         derive [HashStable_Generic]
     }
 }
 
-#[derive(PartialEq, Eq, Hash, Clone, Debug)]
-#[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
-pub enum Variants<V: Idx> {
-    /// Single enum variants, structs/tuples, unions, and all non-ADTs.
-    Single { index: V },
-
-    /// Enum-likes with more than one inhabited variant: each variant comes with
-    /// a *discriminant* (usually the same as the variant index but the user can
-    /// assign explicit discriminant values).  That discriminant is encoded
-    /// as a *tag* on the machine.  The layout of each variant is
-    /// a struct, and they all have space reserved for the tag.
-    /// For enums, the tag is the sole field of the layout.
-    Multiple {
-        tag: Scalar,
-        tag_encoding: TagEncoding<V>,
-        tag_field: usize,
-        variants: IndexVec<V, LayoutS<V>>,
-    },
-}
-
-#[derive(PartialEq, Eq, Hash, Clone, Debug)]
-#[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
-pub enum TagEncoding<V: Idx> {
-    /// The tag directly stores the discriminant, but possibly with a smaller layout
-    /// (so converting the tag to the discriminant can require sign extension).
-    Direct,
-
-    /// Niche (values invalid for a type) encoding the discriminant:
-    /// Discriminant and variant index coincide.
-    /// The variant `untagged_variant` contains a niche at an arbitrary
-    /// offset (field `tag_field` of the enum), which for a variant with
-    /// discriminant `d` is set to
-    /// `(d - niche_variants.start).wrapping_add(niche_start)`.
-    ///
-    /// For example, `Option<(usize, &T)>`  is represented such that
-    /// `None` has a null pointer for the second tuple field, and
-    /// `Some` is the identity function (with a non-null reference).
-    Niche { untagged_variant: V, niche_variants: RangeInclusive<V>, niche_start: u128 },
-}
-
-#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
-#[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
-pub struct Niche {
-    pub offset: Size,
-    pub value: Primitive,
-    pub valid_range: WrappingRange,
-}
-
-impl Niche {
-    pub fn from_scalar<C: HasDataLayout>(cx: &C, offset: Size, scalar: Scalar) -> Option<Self> {
-        let Scalar::Initialized { value, valid_range } = scalar else { return None };
-        let niche = Niche { offset, value, valid_range };
-        if niche.available(cx) > 0 { Some(niche) } else { None }
-    }
-
-    pub fn available<C: HasDataLayout>(&self, cx: &C) -> u128 {
-        let Self { value, valid_range: v, .. } = *self;
-        let size = value.size(cx);
-        assert!(size.bits() <= 128);
-        let max_value = size.unsigned_int_max();
-
-        // Find out how many values are outside the valid range.
-        let niche = v.end.wrapping_add(1)..v.start;
-        niche.end.wrapping_sub(niche.start) & max_value
-    }
-
-    pub fn reserve<C: HasDataLayout>(&self, cx: &C, count: u128) -> Option<(u128, Scalar)> {
-        assert!(count > 0);
-
-        let Self { value, valid_range: v, .. } = *self;
-        let size = value.size(cx);
-        assert!(size.bits() <= 128);
-        let max_value = size.unsigned_int_max();
-
-        let niche = v.end.wrapping_add(1)..v.start;
-        let available = niche.end.wrapping_sub(niche.start) & max_value;
-        if count > available {
-            return None;
-        }
-
-        // Extend the range of valid values being reserved by moving either `v.start` or `v.end` bound.
-        // Given an eventual `Option<T>`, we try to maximize the chance for `None` to occupy the niche of zero.
-        // This is accomplished by preferring enums with 2 variants(`count==1`) and always taking the shortest path to niche zero.
-        // Having `None` in niche zero can enable some special optimizations.
-        //
-        // Bound selection criteria:
-        // 1. Select closest to zero given wrapping semantics.
-        // 2. Avoid moving past zero if possible.
-        //
-        // In practice this means that enums with `count > 1` are unlikely to claim niche zero, since they have to fit perfectly.
-        // If niche zero is already reserved, the selection of bounds are of little interest.
-        let move_start = |v: WrappingRange| {
-            let start = v.start.wrapping_sub(count) & max_value;
-            Some((start, Scalar::Initialized { value, valid_range: v.with_start(start) }))
-        };
-        let move_end = |v: WrappingRange| {
-            let start = v.end.wrapping_add(1) & max_value;
-            let end = v.end.wrapping_add(count) & max_value;
-            Some((start, Scalar::Initialized { value, valid_range: v.with_end(end) }))
-        };
-        let distance_end_zero = max_value - v.end;
-        if v.start > v.end {
-            // zero is unavailable because wrapping occurs
-            move_end(v)
-        } else if v.start <= distance_end_zero {
-            if count <= v.start {
-                move_start(v)
-            } else {
-                // moved past zero, use other bound
-                move_end(v)
-            }
-        } else {
-            let end = v.end.wrapping_add(count) & max_value;
-            let overshot_zero = (1..=v.end).contains(&end);
-            if overshot_zero {
-                // moved past zero, use other bound
-                move_start(v)
-            } else {
-                move_end(v)
-            }
-        }
-    }
-}
-
-#[derive(PartialEq, Eq, Hash, Clone)]
-#[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
-pub struct LayoutS<V: Idx> {
-    /// Says where the fields are located within the layout.
-    pub fields: FieldsShape,
-
-    /// Encodes information about multi-variant layouts.
-    /// Even with `Multiple` variants, a layout still has its own fields! Those are then
-    /// shared between all variants. One of them will be the discriminant,
-    /// but e.g. generators can have more.
-    ///
-    /// To access all fields of this layout, both `fields` and the fields of the active variant
-    /// must be taken into account.
-    pub variants: Variants<V>,
-
-    /// The `abi` defines how this data is passed between functions, and it defines
-    /// value restrictions via `valid_range`.
-    ///
-    /// Note that this is entirely orthogonal to the recursive structure defined by
-    /// `variants` and `fields`; for example, `ManuallyDrop<Result<isize, isize>>` has
-    /// `Abi::ScalarPair`! So, even with non-`Aggregate` `abi`, `fields` and `variants`
-    /// have to be taken into account to find all fields of this layout.
-    pub abi: Abi,
-
-    /// The leaf scalar with the largest number of invalid values
-    /// (i.e. outside of its `valid_range`), if it exists.
-    pub largest_niche: Option<Niche>,
-
-    pub align: AbiAndPrefAlign,
-    pub size: Size,
-}
-
-impl<V: Idx> LayoutS<V> {
-    pub fn scalar<C: HasDataLayout>(cx: &C, scalar: Scalar) -> Self {
-        let largest_niche = Niche::from_scalar(cx, Size::ZERO, scalar);
-        let size = scalar.size(cx);
-        let align = scalar.align(cx);
-        LayoutS {
-            variants: Variants::Single { index: V::new(0) },
-            fields: FieldsShape::Primitive,
-            abi: Abi::Scalar(scalar),
-            largest_niche,
-            size,
-            align,
-        }
-    }
-
-    #[inline]
-    pub fn fields(&self) -> &FieldsShape {
-        &self.fields
-    }
-
-    #[inline]
-    pub fn variants(&self) -> &Variants<V> {
-        &self.variants
-    }
-
-    #[inline]
-    pub fn abi(&self) -> Abi {
-        self.abi
-    }
-
-    #[inline]
-    pub fn largest_niche(&self) -> Option<Niche> {
-        self.largest_niche
-    }
-
-    #[inline]
-    pub fn align(&self) -> AbiAndPrefAlign {
-        self.align
-    }
-
-    #[inline]
-    pub fn size(&self) -> Size {
-        self.size
-    }
-}
-
-impl<V: Idx> fmt::Debug for LayoutS<V> {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        // This is how `Layout` used to print before it become
-        // `Interned<LayoutS>`. We print it like this to avoid having to update
-        // expected output in a lot of tests.
-        let LayoutS { size, align, abi, fields, largest_niche, variants } = self;
-        f.debug_struct("Layout")
-            .field("size", size)
-            .field("align", align)
-            .field("abi", abi)
-            .field("fields", fields)
-            .field("largest_niche", largest_niche)
-            .field("variants", variants)
-            .finish()
-    }
-}
-
-#[cfg(feature = "nightly")]
 #[derive(Copy, Clone, PartialEq, Eq, Hash, HashStable_Generic)]
 #[rustc_pass_by_value]
 pub struct Layout<'a>(pub Interned<'a, LayoutS<VariantIdx>>);
 
-#[cfg(feature = "nightly")]
 impl<'a> fmt::Debug for Layout<'a> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         // See comment on `<LayoutS as Debug>::fmt` above.
@@ -1499,7 +36,6 @@ impl<'a> fmt::Debug for Layout<'a> {
     }
 }
 
-#[cfg(feature = "nightly")]
 impl<'a> Layout<'a> {
     pub fn fields(self) -> &'a FieldsShape {
         &self.0.0.fields
@@ -1533,15 +69,12 @@ impl<'a> Layout<'a> {
 /// to that obtained from `layout_of(ty)`, as we need to produce
 /// layouts for which Rust types do not exist, such as enum variants
 /// or synthetic fields of enums (i.e., discriminants) and fat pointers.
-#[cfg(feature = "nightly")]
-#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
-#[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, HashStable_Generic)]
 pub struct TyAndLayout<'a, Ty> {
     pub ty: Ty,
     pub layout: Layout<'a>,
 }
 
-#[cfg(feature = "nightly")]
 impl<'a, Ty> Deref for TyAndLayout<'a, Ty> {
     type Target = &'a LayoutS<VariantIdx>;
     fn deref(&self) -> &&'a LayoutS<VariantIdx> {
@@ -1549,44 +82,8 @@ impl<'a, Ty> Deref for TyAndLayout<'a, Ty> {
     }
 }
 
-#[derive(Copy, Clone, PartialEq, Eq, Debug)]
-pub enum PointerKind {
-    /// Most general case, we know no restrictions to tell LLVM.
-    SharedMutable,
-
-    /// `&T` where `T` contains no `UnsafeCell`, is `dereferenceable`, `noalias` and `readonly`.
-    Frozen,
-
-    /// `&mut T` which is `dereferenceable` and `noalias` but not `readonly`.
-    UniqueBorrowed,
-
-    /// `&mut !Unpin`, which is `dereferenceable` but neither `noalias` nor `readonly`.
-    UniqueBorrowedPinned,
-
-    /// `Box<T>`, which is `noalias` (even on return types, unlike the above) but neither `readonly`
-    /// nor `dereferenceable`.
-    UniqueOwned,
-}
-
-#[derive(Copy, Clone, Debug)]
-pub struct PointeeInfo {
-    pub size: Size,
-    pub align: Align,
-    pub safe: Option<PointerKind>,
-    pub address_space: AddressSpace,
-}
-
-/// Used in `might_permit_raw_init` to indicate the kind of initialisation
-/// that is checked to be valid
-#[derive(Copy, Clone, Debug, PartialEq, Eq)]
-pub enum InitKind {
-    Zero,
-    UninitMitigated0x01Fill,
-}
-
 /// Trait that needs to be implemented by the higher-level type representation
 /// (e.g. `rustc_middle::ty::Ty`), to provide `rustc_target::abi` functionality.
-#[cfg(feature = "nightly")]
 pub trait TyAbiInterface<'a, C>: Sized {
     fn ty_and_layout_for_variant(
         this: TyAndLayout<'a, Self>,
@@ -1605,7 +102,6 @@ pub trait TyAbiInterface<'a, C>: Sized {
     fn is_unit(this: TyAndLayout<'a, Self>) -> bool;
 }
 
-#[cfg(feature = "nightly")]
 impl<'a, Ty> TyAndLayout<'a, Ty> {
     pub fn for_variant<C>(self, cx: &C, variant_index: VariantIdx) -> Self
     where
@@ -1675,7 +171,7 @@ impl<'a, Ty> TyAndLayout<'a, Ty> {
     }
 }
 
-impl<V: Idx> LayoutS<V> {
+impl<'a, Ty> TyAndLayout<'a, Ty> {
     /// Returns `true` if the layout corresponds to an unsized type.
     pub fn is_unsized(&self) -> bool {
         self.abi.is_unsized()
@@ -1695,13 +191,3 @@ impl<V: Idx> LayoutS<V> {
         }
     }
 }
-
-#[derive(Copy, Clone, Debug)]
-pub enum StructKind {
-    /// A tuple, closure, or univariant which cannot be coerced to unsized.
-    AlwaysSized,
-    /// A univariant, the last field of which may be coerced to unsized.
-    MaybeUnsized,
-    /// A univariant, but with a prefix of an arbitrary size & alignment (e.g., enum tag).
-    Prefixed(Size, Align),
-}
diff --git a/compiler/rustc_target/src/lib.rs b/compiler/rustc_target/src/lib.rs
index 1065980a26a..b69a0a645a4 100644
--- a/compiler/rustc_target/src/lib.rs
+++ b/compiler/rustc_target/src/lib.rs
@@ -8,13 +8,13 @@
 //! LLVM.
 
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
-#![cfg_attr(feature = "nightly", feature(assert_matches))]
-#![cfg_attr(feature = "nightly", feature(associated_type_bounds))]
-#![cfg_attr(feature = "nightly", feature(exhaustive_patterns))]
-#![cfg_attr(feature = "nightly", feature(min_specialization))]
-#![cfg_attr(feature = "nightly", feature(never_type))]
-#![cfg_attr(feature = "nightly", feature(rustc_attrs))]
-#![cfg_attr(feature = "nightly", feature(step_trait))]
+#![feature(assert_matches)]
+#![feature(associated_type_bounds)]
+#![feature(exhaustive_patterns)]
+#![feature(min_specialization)]
+#![feature(never_type)]
+#![feature(rustc_attrs)]
+#![feature(step_trait)]
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]
 
@@ -22,27 +22,20 @@ use std::iter::FromIterator;
 use std::path::{Path, PathBuf};
 
 #[macro_use]
-#[cfg(feature = "nightly")]
 extern crate rustc_macros;
 
 #[macro_use]
-#[cfg(feature = "nightly")]
 extern crate tracing;
 
 pub mod abi;
-#[cfg(feature = "nightly")]
 pub mod asm;
 pub mod json;
-#[cfg(feature = "nightly")]
 pub mod spec;
 
 #[cfg(test)]
 mod tests;
 
-/// Requirements for a `StableHashingContext` to be used in this crate.
-/// This is a hack to allow using the `HashStable_Generic` derive macro
-/// instead of implementing everything in `rustc_middle`.
-pub trait HashStableContext {}
+pub use rustc_abi::HashStableContext;
 
 /// The name of rustc's own place to organize libraries.
 ///
diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs
index c633ef1e761..bd5b10d6aa7 100644
--- a/compiler/rustc_target/src/spec/mod.rs
+++ b/compiler/rustc_target/src/spec/mod.rs
@@ -35,7 +35,10 @@
 //! to the list specified by the target, rather than replace.
 
 use crate::abi::call::Conv;
-use crate::abi::Endian;
+use crate::abi::{
+    AbiAndPrefAlign, AddressSpace, Align, Endian, Integer, Size, TargetDataLayout,
+    TargetDataLayoutErrors,
+};
 use crate::json::{Json, ToJson};
 use crate::spec::abi::{lookup as lookup_abi, Abi};
 use crate::spec::crt_objects::{CrtObjects, LinkSelfContainedDefault};
@@ -1317,6 +1320,120 @@ pub struct Target {
     pub options: TargetOptions,
 }
 
+impl Target {
+    pub fn parse_data_layout<'a>(&'a self) -> Result<TargetDataLayout, TargetDataLayoutErrors<'a>> {
+        // Parse an address space index from a string.
+        let parse_address_space = |s: &'a str, cause: &'a str| {
+            s.parse::<u32>().map(AddressSpace).map_err(|err| {
+                TargetDataLayoutErrors::InvalidAddressSpace { addr_space: s, cause, err }
+            })
+        };
+
+        // Parse a bit count from a string.
+        let parse_bits = |s: &'a str, kind: &'a str, cause: &'a str| {
+            s.parse::<u64>().map_err(|err| TargetDataLayoutErrors::InvalidBits {
+                kind,
+                bit: s,
+                cause,
+                err,
+            })
+        };
+
+        // Parse a size string.
+        let size = |s: &'a str, cause: &'a str| parse_bits(s, "size", cause).map(Size::from_bits);
+
+        // Parse an alignment string.
+        let align = |s: &[&'a str], cause: &'a str| {
+            if s.is_empty() {
+                return Err(TargetDataLayoutErrors::MissingAlignment { cause });
+            }
+            let align_from_bits = |bits| {
+                Align::from_bits(bits)
+                    .map_err(|err| TargetDataLayoutErrors::InvalidAlignment { cause, err })
+            };
+            let abi = parse_bits(s[0], "alignment", cause)?;
+            let pref = s.get(1).map_or(Ok(abi), |pref| parse_bits(pref, "alignment", cause))?;
+            Ok(AbiAndPrefAlign { abi: align_from_bits(abi)?, pref: align_from_bits(pref)? })
+        };
+
+        let mut dl = TargetDataLayout::default();
+        let mut i128_align_src = 64;
+        for spec in self.data_layout.split('-') {
+            let spec_parts = spec.split(':').collect::<Vec<_>>();
+
+            match &*spec_parts {
+                ["e"] => dl.endian = Endian::Little,
+                ["E"] => dl.endian = Endian::Big,
+                [p] if p.starts_with('P') => {
+                    dl.instruction_address_space = parse_address_space(&p[1..], "P")?
+                }
+                ["a", ref a @ ..] => dl.aggregate_align = align(a, "a")?,
+                ["f32", ref a @ ..] => dl.f32_align = align(a, "f32")?,
+                ["f64", ref a @ ..] => dl.f64_align = align(a, "f64")?,
+                [p @ "p", s, ref a @ ..] | [p @ "p0", s, ref a @ ..] => {
+                    dl.pointer_size = size(s, p)?;
+                    dl.pointer_align = align(a, p)?;
+                }
+                [s, ref a @ ..] if s.starts_with('i') => {
+                    let Ok(bits) = s[1..].parse::<u64>() else {
+                        size(&s[1..], "i")?; // For the user error.
+                        continue;
+                    };
+                    let a = align(a, s)?;
+                    match bits {
+                        1 => dl.i1_align = a,
+                        8 => dl.i8_align = a,
+                        16 => dl.i16_align = a,
+                        32 => dl.i32_align = a,
+                        64 => dl.i64_align = a,
+                        _ => {}
+                    }
+                    if bits >= i128_align_src && bits <= 128 {
+                        // Default alignment for i128 is decided by taking the alignment of
+                        // largest-sized i{64..=128}.
+                        i128_align_src = bits;
+                        dl.i128_align = a;
+                    }
+                }
+                [s, ref a @ ..] if s.starts_with('v') => {
+                    let v_size = size(&s[1..], "v")?;
+                    let a = align(a, s)?;
+                    if let Some(v) = dl.vector_align.iter_mut().find(|v| v.0 == v_size) {
+                        v.1 = a;
+                        continue;
+                    }
+                    // No existing entry, add a new one.
+                    dl.vector_align.push((v_size, a));
+                }
+                _ => {} // Ignore everything else.
+            }
+        }
+
+        // Perform consistency checks against the Target information.
+        if dl.endian != self.endian {
+            return Err(TargetDataLayoutErrors::InconsistentTargetArchitecture {
+                dl: dl.endian.as_str(),
+                target: self.endian.as_str(),
+            });
+        }
+
+        let target_pointer_width: u64 = self.pointer_width.into();
+        if dl.pointer_size.bits() != target_pointer_width {
+            return Err(TargetDataLayoutErrors::InconsistentTargetPointerWidth {
+                pointer_size: dl.pointer_size.bits(),
+                target: self.pointer_width,
+            });
+        }
+
+        dl.c_enum_min_size = match Integer::from_size(Size::from_bits(self.c_enum_min_bits)) {
+            Ok(bits) => bits,
+            Err(err) => return Err(TargetDataLayoutErrors::InvalidBitsSize { err }),
+        };
+
+        Ok(dl)
+    }
+}
+
 pub trait HasTargetSpec {
     fn target_spec(&self) -> &Target;
 }