use rustc crates instead of copy paste

13 files changed, 288 insertions, 2080 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 84dda206db2..589e9322279 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -510,6 +510,8 @@ dependencies = [
  "fst",
  "hashbrown",
  "hir-expand",
+ "hkalbasi-rustc-ap-rustc_abi",
+ "hkalbasi-rustc-ap-rustc_index",
  "indexmap",
  "itertools",
  "la-arena",
@@ -564,6 +566,7 @@ dependencies = [
  "expect-test",
  "hir-def",
  "hir-expand",
+ "hkalbasi-rustc-ap-rustc_index",
  "itertools",
  "la-arena",
  "limit",
@@ -582,6 +585,27 @@ dependencies = [
 ]
 
 [[package]]
+name = "hkalbasi-rustc-ap-rustc_abi"
+version = "0.0.20221125"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29c8368a30e518c0102d670d8515f7d424d875ee615ec7a7b6d29217b57a0371"
+dependencies = [
+ "bitflags",
+ "hkalbasi-rustc-ap-rustc_index",
+ "tracing",
+]
+
+[[package]]
+name = "hkalbasi-rustc-ap-rustc_index"
+version = "0.0.20221125"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c07bba80d7f6a8e1efb0f3e2115ef1eecbf97292dc8cad84e4982226b9aa12e2"
+dependencies = [
+ "arrayvec",
+ "smallvec",
+]
+
+[[package]]
 name = "home"
 version = "0.5.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/crates/hir-def/Cargo.toml b/crates/hir-def/Cargo.toml
index 22f98ea7cd4..9ecce46601b 100644
--- a/crates/hir-def/Cargo.toml
+++ b/crates/hir-def/Cargo.toml
@@ -33,6 +33,8 @@ base-db = { path = "../base-db", version = "0.0.0" }
 syntax = { path = "../syntax", version = "0.0.0" }
 profile = { path = "../profile", version = "0.0.0" }
 hir-expand = { path = "../hir-expand", version = "0.0.0" }
+rustc_abi = { version = "0.0.20221125", package = "hkalbasi-rustc-ap-rustc_abi", default-features = false }
+rustc_index = { version = "0.0.20221125", package = "hkalbasi-rustc-ap-rustc_index", default-features = false }
 mbe = { path = "../mbe", version = "0.0.0" }
 cfg = { path = "../cfg", version = "0.0.0" }
 tt = { path = "../tt", version = "0.0.0" }
diff --git a/crates/hir-def/src/adt.rs b/crates/hir-def/src/adt.rs
index 62efc409868..feed4321489 100644
--- a/crates/hir-def/src/adt.rs
+++ b/crates/hir-def/src/adt.rs
@@ -9,6 +9,7 @@ use hir_expand::{
     HirFileId, InFile,
 };
 use la_arena::{Arena, ArenaMap};
+use rustc_abi::{Integer, IntegerType};
 use syntax::ast::{self, HasName, HasVisibility};
 use tt::{Delimiter, DelimiterKind, Leaf, Subtree, TokenTree};
 
@@ -127,7 +128,24 @@ fn parse_repr_tt(tt: &Subtree) -> Option<ReprOptions> {
                         .map(Either::Left)
                         .or_else(|| BuiltinUint::from_suffix(repr).map(Either::Right))
                     {
-                        int = Some(builtin);
+                        int = Some(match builtin {
+                            Either::Left(bi) => match bi {
+                                BuiltinInt::Isize => IntegerType::Pointer(true),
+                                BuiltinInt::I8 => IntegerType::Fixed(Integer::I8, true),
+                                BuiltinInt::I16 => IntegerType::Fixed(Integer::I16, true),
+                                BuiltinInt::I32 => IntegerType::Fixed(Integer::I32, true),
+                                BuiltinInt::I64 => IntegerType::Fixed(Integer::I64, true),
+                                BuiltinInt::I128 => IntegerType::Fixed(Integer::I128, true),
+                            },
+                            Either::Right(bu) => match bu {
+                                BuiltinUint::Usize => IntegerType::Pointer(false),
+                                BuiltinUint::U8 => IntegerType::Fixed(Integer::I8, false),
+                                BuiltinUint::U16 => IntegerType::Fixed(Integer::I16, false),
+                                BuiltinUint::U32 => IntegerType::Fixed(Integer::I32, false),
+                                BuiltinUint::U64 => IntegerType::Fixed(Integer::I64, false),
+                                BuiltinUint::U128 => IntegerType::Fixed(Integer::I128, false),
+                            },
+                        });
                     }
                     ReprFlags::empty()
                 }
@@ -135,7 +153,7 @@ fn parse_repr_tt(tt: &Subtree) -> Option<ReprOptions> {
         }
     }
 
-    Some(ReprOptions { int, align: max_align, pack: min_pack, flags })
+    Some(ReprOptions { int, align: max_align, pack: min_pack, flags, field_shuffle_seed: 0 })
 }
 
 impl StructData {
@@ -276,10 +294,10 @@ impl EnumData {
         Some(id)
     }
 
-    pub fn variant_body_type(&self) -> Either<BuiltinInt, BuiltinUint> {
+    pub fn variant_body_type(&self) -> IntegerType {
         match self.repr {
             Some(ReprOptions { int: Some(builtin), .. }) => builtin,
-            _ => Either::Left(BuiltinInt::Isize),
+            _ => IntegerType::Pointer(true),
         }
     }
 }
diff --git a/crates/hir-def/src/layout.rs b/crates/hir-def/src/layout.rs
index cc8177376f7..a427c464bc0 100644
--- a/crates/hir-def/src/layout.rs
+++ b/crates/hir-def/src/layout.rs
@@ -1,419 +1,48 @@
-//! Definitions related to binary representations of types
+//! Definitions needed for computing data layout of types.
 
-use bitflags::bitflags;
-use either::Either;
-use std::{
-    cmp, fmt,
-    num::NonZeroUsize,
-    ops::{Add, AddAssign, Mul, Sub},
-};
+use std::cmp;
 
-use crate::{
-    builtin_type::{BuiltinInt, BuiltinUint},
-    LocalEnumVariantId,
+use la_arena::{Idx, RawIdx};
+pub use rustc_abi::{
+    Abi, AbiAndPrefAlign, AddressSpace, Align, Endian, FieldsShape, Integer, IntegerType,
+    LayoutCalculator, Niche, Primitive, ReprFlags, ReprOptions, Scalar, Size, StructKind,
+    TargetDataLayout, WrappingRange,
 };
-use la_arena::ArenaMap;
-
-/// Size of a type in bytes.
-#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-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.raw)
-    }
-}
-
-// 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;
-    }
-}
-
-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 checked_add(self, offset: Size, dl: &TargetDataLayout) -> Option<Size> {
-        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(self, count: u64, dl: &TargetDataLayout) -> Option<Size> {
-        let bytes = self.bytes().checked_mul(count)?;
-        if bytes < dl.obj_size_bound() {
-            Some(Size::from_bytes(bytes))
-        } else {
-            None
-        }
-    }
-
-    #[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
-    }
-
-    /// 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
-    }
+use crate::LocalEnumVariantId;
 
-    #[inline]
-    pub fn signed_int_min(&self) -> i128 {
-        self.sign_extend(1_u128 << (self.bits() - 1)) as i128
-    }
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct RustcEnumVariantIdx(pub LocalEnumVariantId);
 
-    #[inline]
-    pub fn signed_int_max(&self) -> i128 {
-        i128::MAX >> (128 - self.bits())
+impl rustc_index::vec::Idx for RustcEnumVariantIdx {
+    fn new(idx: usize) -> Self {
+        RustcEnumVariantIdx(Idx::from_raw(RawIdx::from(idx as u32)))
     }
 
-    #[inline]
-    pub fn unsigned_int_max(&self) -> u128 {
-        u128::MAX >> (128 - self.bits())
+    fn index(self) -> usize {
+        u32::from(self.0.into_raw()) as usize
     }
 }
 
-#[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),
-}
-
-/// Describes how the fields of a type are located in memory.
-#[derive(PartialEq, Eq, Hash, Debug, Clone)]
-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, dl: &TargetDataLayout) -> 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.checked_mul(i, dl).unwrap()
-            }
-            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();
+pub type Layout = rustc_abi::LayoutS<RustcEnumVariantIdx>;
+pub type TagEncoding = rustc_abi::TagEncoding<RustcEnumVariantIdx>;
+pub type Variants = rustc_abi::Variants<RustcEnumVariantIdx>;
 
-        // 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
-                }
-            }
-        })
-    }
-}
-
-/// Integers, also used for enum discriminants.
-#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
-pub enum Integer {
-    I8,
-    I16,
-    I32,
-    I64,
-    I128,
+pub trait IntegerExt {
+    fn repr_discr(
+        dl: &TargetDataLayout,
+        repr: &ReprOptions,
+        min: i128,
+        max: i128,
+    ) -> Result<(Integer, bool), LayoutError>;
 }
 
-impl Integer {
-    #[inline]
-    pub fn size(self) -> Size {
-        match self {
-            Integer::I8 => Size::from_bytes(1),
-            Integer::I16 => Size::from_bytes(2),
-            Integer::I32 => Size::from_bytes(4),
-            Integer::I64 => Size::from_bytes(8),
-            Integer::I128 => Size::from_bytes(16),
-        }
-    }
-
-    pub fn align(self, dl: &TargetDataLayout) -> AbiAndPrefAlign {
-        match self {
-            Integer::I8 => dl.i8_align,
-            Integer::I16 => dl.i16_align,
-            Integer::I32 => dl.i32_align,
-            Integer::I64 => dl.i64_align,
-            Integer::I128 => dl.i128_align,
-        }
-    }
-
-    /// Finds the smallest integer with the given alignment.
-    pub fn for_align(dl: &TargetDataLayout, wanted: Align) -> Option<Integer> {
-        use Integer::*;
-        for candidate in [I8, I16, I32, I64, I128] {
-            if wanted == candidate.align(dl).abi && wanted.bytes() == candidate.size().bytes() {
-                return Some(candidate);
-            }
-        }
-        None
-    }
-
-    /// 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 => Integer::I8,
-            -0x0000_0000_0000_8000..=0x0000_0000_0000_7fff => Integer::I16,
-            -0x0000_0000_8000_0000..=0x0000_0000_7fff_ffff => Integer::I32,
-            -0x8000_0000_0000_0000..=0x7fff_ffff_ffff_ffff => Integer::I64,
-            _ => Integer::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 => Integer::I8,
-            0..=0x0000_0000_0000_ffff => Integer::I16,
-            0..=0x0000_0000_ffff_ffff => Integer::I32,
-            0..=0xffff_ffff_ffff_ffff => Integer::I64,
-            _ => Integer::I128,
-        }
-    }
-
-    /// Gets the Integer type from an attr::IntType.
-    pub fn from_attr(dl: &TargetDataLayout, ity: Either<BuiltinInt, BuiltinUint>) -> Integer {
-        match ity {
-            Either::Left(BuiltinInt::I8) | Either::Right(BuiltinUint::U8) => Integer::I8,
-            Either::Left(BuiltinInt::I16) | Either::Right(BuiltinUint::U16) => Integer::I16,
-            Either::Left(BuiltinInt::I32) | Either::Right(BuiltinUint::U32) => Integer::I32,
-            Either::Left(BuiltinInt::I64) | Either::Right(BuiltinUint::U64) => Integer::I64,
-            Either::Left(BuiltinInt::I128) | Either::Right(BuiltinUint::U128) => Integer::I128,
-            Either::Left(BuiltinInt::Isize) | Either::Right(BuiltinUint::Usize) => {
-                dl.ptr_sized_integer()
-            }
-        }
-    }
-
+impl IntegerExt for Integer {
     /// Finds the appropriate Integer type and signedness for the given
     /// signed discriminant range and `#[repr]` attribute.
     /// N.B.: `u128` values above `i128::MAX` will be treated as signed, but
     /// that shouldn't affect anything, other than maybe debuginfo.
-    pub fn repr_discr(
+    fn repr_discr(
         dl: &TargetDataLayout,
         repr: &ReprOptions,
         min: i128,
@@ -428,7 +57,7 @@ impl Integer {
 
         if let Some(ity) = repr.int {
             let discr = Integer::from_attr(dl, ity);
-            let fit = if ity.is_left() { signed_fit } else { unsigned_fit };
+            let fit = if ity.is_signed() { signed_fit } else { unsigned_fit };
             if discr < fit {
                 return Err(LayoutError::UserError(
                     "Integer::repr_discr: `#[repr]` hint too small for \
@@ -436,7 +65,7 @@ impl Integer {
                         .to_string(),
                 ));
             }
-            return Ok((discr, ity.is_left()));
+            return Ok((discr, ity.is_signed()));
         }
 
         let at_least = if repr.c() {
@@ -457,717 +86,11 @@ impl Integer {
     }
 }
 
-/// 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())
-    }
-}
-
-/// 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);
-
-/// 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 TargetDataLayout {
-    /// 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 => Integer::I16,
-            32 => Integer::I32,
-            64 => Integer::I64,
-            bits => panic!("ptr_sized_integer: unknown pointer bit size {}", bits),
-        }
-    }
-}
-
-/// Fundamental unit of memory access and layout.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
-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(self, dl: &TargetDataLayout) -> Size {
-        match self {
-            Primitive::Int(i, _) => i.size(),
-            Primitive::F32 => Size::from_bits(32),
-            Primitive::F64 => Size::from_bits(64),
-            Primitive::Pointer => dl.pointer_size,
-        }
-    }
-
-    pub fn align(self, dl: &TargetDataLayout) -> AbiAndPrefAlign {
-        match self {
-            Primitive::Int(i, _) => i.align(dl),
-            Primitive::F32 => dl.f32_align,
-            Primitive::F64 => dl.f64_align,
-            Primitive::Pointer => dl.pointer_align,
-        }
-    }
-}
-
-/// 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)]
-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)]
-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: Primitive::Int(Integer::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: &TargetDataLayout) -> AbiAndPrefAlign {
-        self.primitive().align(cx)
-    }
-
-    pub fn size(self, cx: &TargetDataLayout) -> Size {
-        self.primitive().size(cx)
-    }
-
-    #[inline]
-    pub fn to_union(&self) -> Self {
-        Self::Union { value: self.primitive() }
-    }
-
-    #[inline]
-    pub fn valid_range(&self, cx: &TargetDataLayout) -> 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(&self, cx: &TargetDataLayout) -> 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 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)]
-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,
-        }
-    }
-
-    /// 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(_))
-    }
-}
-
-/// Alignment of a type in bytes (always a power of two).
-#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-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_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)]
-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) }
-    }
-}
-
-#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
-pub struct Niche {
-    pub offset: Size,
-    pub value: Primitive,
-    pub valid_range: WrappingRange,
-}
-
-impl Niche {
-    pub fn from_scalar(cx: &TargetDataLayout, offset: Size, scalar: Scalar) -> Option<Self> {
-        let (value, valid_range) = match scalar {
-            Scalar::Initialized { value, valid_range } => (value, valid_range),
-            _ => return None,
-        };
-        let niche = Niche { offset, value, valid_range };
-        if niche.available(cx) > 0 {
-            Some(niche)
-        } else {
-            None
-        }
-    }
-
-    pub fn available(&self, cx: &TargetDataLayout) -> 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(&self, cx: &TargetDataLayout, 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, Debug, Clone)]
-pub enum TagEncoding {
-    /// 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: LocalEnumVariantId, niche_start: u128 },
-}
-
-#[derive(PartialEq, Eq, Hash, Debug, Clone)]
-pub enum Variants {
-    /// Single enum variants, structs/tuples, unions, and all non-ADTs.
-    Single,
-
-    /// 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,
-        tag_field: usize,
-        variants: ArenaMap<LocalEnumVariantId, Layout>,
-    },
-}
-
-bitflags! {
-    #[derive(Default)]
-    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;
-        // 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;
-    }
-}
-
-/// Represents the repr options provided by the user,
-#[derive(Copy, Clone, Debug, Eq, PartialEq, Default)]
-pub struct ReprOptions {
-    pub int: Option<Either<BuiltinInt, BuiltinUint>>,
-    pub align: Option<Align>,
-    pub pack: Option<Align>,
-    pub flags: ReprFlags,
-}
-
-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) -> Either<BuiltinInt, BuiltinUint> {
-        self.int.unwrap_or(Either::Left(BuiltinInt::Isize))
-    }
-
-    /// 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 `#[repr()]` should inhibit union ABI optimisations.
-    pub fn inhibit_union_abi_opt(&self) -> bool {
-        self.c()
-    }
-}
-
-#[derive(PartialEq, Eq, Hash, Clone)]
-pub struct Layout {
-    /// 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,
-
-    /// 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 Layout {
-    pub fn scalar(dl: &TargetDataLayout, scalar: Scalar) -> Self {
-        let largest_niche = Niche::from_scalar(dl, Size::ZERO, scalar);
-        let size = scalar.size(dl);
-        let align = scalar.align(dl);
-        Layout {
-            variants: Variants::Single,
-            fields: FieldsShape::Primitive,
-            abi: Abi::Scalar(scalar),
-            largest_niche,
-            size,
-            align,
-        }
-    }
-}
-
-impl fmt::Debug for Layout {
-    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 Layout { 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()
-    }
-}
-
-impl Layout {
-    pub fn is_unsized(&self) -> bool {
-        self.abi.is_unsized()
-    }
-
-    /// Returns `true` if the type is a ZST and not unsized.
-    pub fn is_zst(&self) -> bool {
-        match self.abi {
-            Abi::Scalar(_) | Abi::ScalarPair(..) | Abi::Vector { .. } => false,
-            Abi::Uninhabited => self.size.bytes() == 0,
-            Abi::Aggregate { sized } => sized && self.size.bytes() == 0,
-        }
-    }
-}
-
 #[derive(Debug, PartialEq, Eq, Clone)]
 pub enum LayoutError {
     UserError(String),
     SizeOverflow,
     HasPlaceholder,
     NotImplemented,
+    Unknown,
 }
diff --git a/crates/hir-ty/Cargo.toml b/crates/hir-ty/Cargo.toml
index 802face8524..87a206e30fb 100644
--- a/crates/hir-ty/Cargo.toml
+++ b/crates/hir-ty/Cargo.toml
@@ -25,6 +25,7 @@ chalk-derive = "0.87.0"
 la-arena = { version = "0.3.0", path = "../../lib/la-arena" }
 once_cell = "1.15.0"
 typed-arena = "2.0.1"
+rustc_index = { version = "0.0.20221125", package = "hkalbasi-rustc-ap-rustc_index", default-features = false }
 
 stdx = { path = "../stdx", version = "0.0.0" }
 hir-def = { path = "../hir-def", version = "0.0.0" }
diff --git a/crates/hir-ty/src/infer.rs b/crates/hir-ty/src/infer.rs
index 112eb5bd84c..874a54fc3ee 100644
--- a/crates/hir-ty/src/infer.rs
+++ b/crates/hir-ty/src/infer.rs
@@ -19,10 +19,11 @@ use std::sync::Arc;
 use chalk_ir::{cast::Cast, ConstValue, DebruijnIndex, Mutability, Safety, Scalar, TypeFlags};
 use hir_def::{
     body::Body,
-    builtin_type::BuiltinType,
+    builtin_type::{BuiltinInt, BuiltinType, BuiltinUint},
     data::{ConstData, StaticData},
     expr::{BindingAnnotation, ExprId, PatId},
     lang_item::LangItemTarget,
+    layout::Integer,
     path::{path, Path},
     resolver::{HasResolver, ResolveValueResult, Resolver, TypeNs, ValueNs},
     type_ref::TypeRef,
@@ -70,8 +71,26 @@ pub(crate) fn infer_query(db: &dyn HirDatabase, def: DefWithBodyId) -> Arc<Infer
         DefWithBodyId::StaticId(s) => ctx.collect_static(&db.static_data(s)),
         DefWithBodyId::VariantId(v) => {
             ctx.return_ty = TyBuilder::builtin(match db.enum_data(v.parent).variant_body_type() {
-                Either::Left(builtin) => BuiltinType::Int(builtin),
-                Either::Right(builtin) => BuiltinType::Uint(builtin),
+                hir_def::layout::IntegerType::Pointer(signed) => match signed {
+                    true => BuiltinType::Int(BuiltinInt::Isize),
+                    false => BuiltinType::Uint(BuiltinUint::Usize),
+                },
+                hir_def::layout::IntegerType::Fixed(size, signed) => match signed {
+                    true => BuiltinType::Int(match size {
+                        Integer::I8 => BuiltinInt::I8,
+                        Integer::I16 => BuiltinInt::I16,
+                        Integer::I32 => BuiltinInt::I32,
+                        Integer::I64 => BuiltinInt::I64,
+                        Integer::I128 => BuiltinInt::I128,
+                    }),
+                    false => BuiltinType::Uint(match size {
+                        Integer::I8 => BuiltinUint::U8,
+                        Integer::I16 => BuiltinUint::U16,
+                        Integer::I32 => BuiltinUint::U32,
+                        Integer::I64 => BuiltinUint::U64,
+                        Integer::I128 => BuiltinUint::U128,
+                    }),
+                },
             });
         }
     }
diff --git a/crates/hir-ty/src/layout.rs b/crates/hir-ty/src/layout.rs
index ca39fde1189..3c6489fa97b 100644
--- a/crates/hir-ty/src/layout.rs
+++ b/crates/hir-ty/src/layout.rs
@@ -1,12 +1,15 @@
 //! Compute the binary representation of a type
 
+use std::sync::Arc;
+
 use chalk_ir::{AdtId, TyKind};
 pub(self) use hir_def::layout::*;
 use hir_def::LocalFieldId;
+use stdx::never;
 
 use crate::{db::HirDatabase, Interner, Substitution, Ty};
 
-use self::adt::univariant;
+use self::adt::struct_variant_idx;
 pub use self::{
     adt::{layout_of_adt_query, layout_of_adt_recover},
     target::current_target_data_layout_query,
@@ -21,6 +24,22 @@ macro_rules! user_error {
 mod adt;
 mod target;
 
+struct LayoutCx<'a> {
+    db: &'a dyn HirDatabase,
+}
+
+impl LayoutCalculator for LayoutCx<'_> {
+    type TargetDataLayoutRef = Arc<TargetDataLayout>;
+
+    fn delay_bug(&self, txt: &str) {
+        never!("{}", txt);
+    }
+
+    fn current_data_layout(&self) -> Arc<TargetDataLayout> {
+        self.db.current_target_data_layout()
+    }
+}
+
 fn scalar_unit(dl: &TargetDataLayout, value: Primitive) -> Scalar {
     Scalar::Initialized { value, valid_range: WrappingRange::full(value.size(dl)) }
 }
@@ -29,34 +48,9 @@ fn scalar(dl: &TargetDataLayout, value: Primitive) -> Layout {
     Layout::scalar(dl, scalar_unit(dl, value))
 }
 
-fn scalar_pair(dl: &TargetDataLayout, a: Scalar, b: Scalar) -> Layout {
-    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.checked_add(b.size(dl), dl).unwrap().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));
-
-    Layout {
-        variants: Variants::Single,
-        fields: FieldsShape::Arbitrary {
-            offsets: vec![Size::ZERO, b_offset],
-            memory_index: vec![0, 1],
-        },
-        abi: Abi::ScalarPair(a, b),
-        largest_niche,
-        align,
-        size,
-    }
-}
-
 pub fn layout_of_ty(db: &dyn HirDatabase, ty: &Ty) -> Result<Layout, LayoutError> {
     let dl = &*db.current_target_data_layout();
+    let cx = LayoutCx { db };
     Ok(match ty.kind(Interner) {
         TyKind::Adt(AdtId(def), subst) => db.layout_of_adt(*def, subst.clone())?,
         TyKind::Scalar(s) => match s {
@@ -113,14 +107,13 @@ pub fn layout_of_ty(db: &dyn HirDatabase, ty: &Ty) -> Result<Layout, LayoutError
         TyKind::Tuple(len, tys) => {
             let kind = if *len == 0 { StructKind::AlwaysSized } else { StructKind::MaybeUnsized };
 
-            univariant(
-                dl,
-                &tys.iter(Interner)
-                    .map(|k| layout_of_ty(db, k.assert_ty_ref(Interner)))
-                    .collect::<Result<Vec<_>, _>>()?,
-                &ReprOptions::default(),
-                kind,
-            )?
+            let fields = tys
+                .iter(Interner)
+                .map(|k| layout_of_ty(db, k.assert_ty_ref(Interner)))
+                .collect::<Result<Vec<_>, _>>()?;
+            let fields = fields.iter().collect::<Vec<_>>();
+            let fields = fields.iter().collect::<Vec<_>>();
+            cx.univariant(dl, &fields, &ReprOptions::default(), kind).ok_or(LayoutError::Unknown)?
         }
         TyKind::Array(element, count) => {
             let count = match count.data(Interner).value {
@@ -146,7 +139,7 @@ pub fn layout_of_ty(db: &dyn HirDatabase, ty: &Ty) -> Result<Layout, LayoutError
             let largest_niche = if count != 0 { element.largest_niche } else { None };
 
             Layout {
-                variants: Variants::Single,
+                variants: Variants::Single { index: struct_variant_idx() },
                 fields: FieldsShape::Array { stride: element.size, count },
                 abi,
                 largest_niche,
@@ -157,7 +150,7 @@ pub fn layout_of_ty(db: &dyn HirDatabase, ty: &Ty) -> Result<Layout, LayoutError
         TyKind::Slice(element) => {
             let element = layout_of_ty(db, element)?;
             Layout {
-                variants: Variants::Single,
+                variants: Variants::Single { index: struct_variant_idx() },
                 fields: FieldsShape::Array { stride: element.size, count: 0 },
                 abi: Abi::Aggregate { sized: false },
                 largest_niche: None,
@@ -194,13 +187,11 @@ pub fn layout_of_ty(db: &dyn HirDatabase, ty: &Ty) -> Result<Layout, LayoutError
             };
 
             // Effectively a (ptr, meta) tuple.
-            scalar_pair(dl, data_ptr, metadata)
-        }
-        TyKind::FnDef(_, _) => {
-            univariant(dl, &[], &ReprOptions::default(), StructKind::AlwaysSized)?
+            cx.scalar_pair(data_ptr, metadata)
         }
+        TyKind::FnDef(_, _) => layout_of_unit(&cx, dl)?,
         TyKind::Str => Layout {
-            variants: Variants::Single,
+            variants: Variants::Single { index: struct_variant_idx() },
             fields: FieldsShape::Array { stride: Size::from_bytes(1), count: 0 },
             abi: Abi::Aggregate { sized: false },
             largest_niche: None,
@@ -208,7 +199,7 @@ pub fn layout_of_ty(db: &dyn HirDatabase, ty: &Ty) -> Result<Layout, LayoutError
             size: Size::ZERO,
         },
         TyKind::Never => Layout {
-            variants: Variants::Single,
+            variants: Variants::Single { index: struct_variant_idx() },
             fields: FieldsShape::Primitive,
             abi: Abi::Uninhabited,
             largest_niche: None,
@@ -216,7 +207,7 @@ pub fn layout_of_ty(db: &dyn HirDatabase, ty: &Ty) -> Result<Layout, LayoutError
             size: Size::ZERO,
         },
         TyKind::Dyn(_) | TyKind::Foreign(_) => {
-            let mut unit = univariant(dl, &[], &ReprOptions::default(), StructKind::AlwaysSized)?;
+            let mut unit = layout_of_unit(&cx, dl)?;
             match unit.abi {
                 Abi::Aggregate { ref mut sized } => *sized = false,
                 _ => user_error!("bug"),
@@ -241,6 +232,16 @@ pub fn layout_of_ty(db: &dyn HirDatabase, ty: &Ty) -> Result<Layout, LayoutError
     })
 }
 
+fn layout_of_unit(cx: &LayoutCx<'_>, dl: &TargetDataLayout) -> Result<Layout, LayoutError> {
+    cx.univariant::<RustcEnumVariantIdx, &&Layout>(
+        &dl,
+        &[],
+        &ReprOptions::default(),
+        StructKind::AlwaysSized,
+    )
+    .ok_or(LayoutError::Unknown)
+}
+
 fn struct_tail_erasing_lifetimes(db: &dyn HirDatabase, pointee: Ty) -> Ty {
     match pointee.kind(Interner) {
         TyKind::Adt(AdtId(adt), subst) => match adt {
diff --git a/crates/hir-ty/src/layout/adt.rs b/crates/hir-ty/src/layout/adt.rs
index 9244353f3ae..d9791a4b630 100644
--- a/crates/hir-ty/src/layout/adt.rs
+++ b/crates/hir-ty/src/layout/adt.rs
@@ -1,628 +1,110 @@
 //! Compute the binary representation of structs, unions and enums
 
-use std::{
-    cmp::{self, Ordering},
-    iter,
-    num::NonZeroUsize,
-    ops::Bound,
-};
+use std::ops::Bound;
 
-use chalk_ir::TyKind;
 use hir_def::{
     adt::VariantData,
-    layout::{
-        Abi, AbiAndPrefAlign, Align, FieldsShape, Integer, Layout, LayoutError, Niche, Primitive,
-        ReprOptions, Scalar, Size, StructKind, TagEncoding, TargetDataLayout, Variants,
-        WrappingRange,
-    },
-    AdtId, EnumVariantId, LocalEnumVariantId, UnionId, VariantId,
+    layout::{Integer, IntegerExt, Layout, LayoutCalculator, LayoutError, RustcEnumVariantIdx},
+    AdtId, EnumVariantId, LocalEnumVariantId, VariantId,
 };
-use la_arena::{ArenaMap, RawIdx};
+use la_arena::RawIdx;
+use rustc_index::vec::IndexVec;
 
-struct X(Option<NonZeroUsize>);
+use crate::{db::HirDatabase, lang_items::is_unsafe_cell, layout::field_ty, Substitution};
 
-use crate::{
-    db::HirDatabase,
-    lang_items::is_unsafe_cell,
-    layout::{field_ty, scalar_unit},
-    Interner, Substitution,
-};
+use super::{layout_of_ty, LayoutCx};
 
-use super::layout_of_ty;
+pub(crate) fn struct_variant_idx() -> RustcEnumVariantIdx {
+    RustcEnumVariantIdx(LocalEnumVariantId::from_raw(RawIdx::from(0)))
+}
 
 pub fn layout_of_adt_query(
     db: &dyn HirDatabase,
     def: AdtId,
     subst: Substitution,
 ) -> Result<Layout, LayoutError> {
+    let dl = db.current_target_data_layout();
+    let cx = LayoutCx { db };
     let handle_variant = |def: VariantId, var: &VariantData| {
         var.fields()
             .iter()
             .map(|(fd, _)| layout_of_ty(db, &field_ty(db, def, fd, &subst)))
             .collect::<Result<Vec<_>, _>>()
     };
-    fn struct_variant_idx() -> LocalEnumVariantId {
-        LocalEnumVariantId::from_raw(RawIdx::from(0))
-    }
-    let (variants, is_enum, repr) = match def {
+    let (variants, is_enum, is_union, repr) = match def {
         AdtId::StructId(s) => {
             let data = db.struct_data(s);
-            let mut r = ArenaMap::new();
-            r.insert(struct_variant_idx(), handle_variant(s.into(), &data.variant_data)?);
-            (r, false, data.repr.unwrap_or_default())
+            let mut r = IndexVec::new();
+            r.push(handle_variant(s.into(), &data.variant_data)?);
+            (r, false, false, data.repr.unwrap_or_default())
+        }
+        AdtId::UnionId(id) => {
+            let data = db.union_data(id);
+            let mut r = IndexVec::new();
+            r.push(handle_variant(id.into(), &data.variant_data)?);
+            (r, false, true, data.repr.unwrap_or_default())
         }
-        AdtId::UnionId(id) => return layout_of_union(db, id, &subst),
         AdtId::EnumId(e) => {
             let data = db.enum_data(e);
             let r = data
                 .variants
                 .iter()
                 .map(|(idx, v)| {
-                    Ok((
-                        idx,
-                        handle_variant(
-                            EnumVariantId { parent: e, local_id: idx }.into(),
-                            &v.variant_data,
-                        )?,
-                    ))
+                    handle_variant(
+                        EnumVariantId { parent: e, local_id: idx }.into(),
+                        &v.variant_data,
+                    )
                 })
-                .collect::<Result<_, _>>()?;
-            (r, true, data.repr.unwrap_or_default())
-        }
-    };
-
-    // 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: &[Layout]| {
-        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().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 layout_of_ty(db, &TyKind::Never.intern(Interner)),
-        // If it's a struct, still compute a layout so that we can still compute the
-        // field offsets.
-        None => struct_variant_idx(),
-    };
-
-    let is_univariant = !is_enum ||
-                    // Only one variant is present.
-                    (present_second.is_none() &&
-                        // Representation optimizations are allowed.
-                        !repr.inhibit_enum_layout_opt());
-    let dl = &*db.current_target_data_layout();
-
-    if is_univariant {
-        // 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 {
-            let always_sized = !variants[v].last().unwrap().is_unsized();
-            if !always_sized {
-                StructKind::MaybeUnsized
-            } else {
-                StructKind::AlwaysSized
-            }
-        };
-
-        let mut st = univariant(dl, &variants[v], &repr, kind)?;
-        st.variants = Variants::Single;
-
-        if is_unsafe_cell(def, db) {
-            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 Ok(st);
-        }
-
-        let (start, end) = layout_scalar_valid_range(db, def);
-        match st.abi {
-            Abi::Scalar(ref mut scalar) | Abi::ScalarPair(ref mut scalar, _) => {
-                if let Bound::Included(start) = start {
-                    let valid_range = scalar.valid_range_mut();
-                    valid_range.start = start;
-                }
-                if let Bound::Included(end) = end {
-                    let valid_range = scalar.valid_range_mut();
-                    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),
-                    }
-                }
-            }
-            _ => user_error!("nonscalar layout for layout_scalar_valid_range"),
-        }
-
-        return Ok(st);
-    }
-
-    // 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 {
-        layout: Layout,
-        variants: ArenaMap<LocalEnumVariantId, Layout>,
-    }
-
-    let calculate_niche_filling_layout = || -> Result<Option<TmpLayout>, LayoutError> {
-        // The current code for niche-filling relies on variant indices
-        // instead of actual discriminants, so enums with
-        // explicit discriminants (RFC #2363) would misbehave.
-        if repr.inhibit_enum_layout_opt()
-        // FIXME: bring these codes back
-        // || def
-        //     .variants()
-        //     .iter_enumerated()
-        //     .any(|(i, v)| v.discr != ty::VariantDiscr::Relative(i.as_u32()))
-        {
-            return Ok(None);
-        }
-
-        if variants.iter().count() < 2 {
-            return Ok(None);
-        }
-
-        let mut align = dl.aggregate_align;
-        let mut variant_layouts = variants
-            .iter()
-            .map(|(j, v)| {
-                let mut st = univariant(dl, v, &repr, StructKind::AlwaysSized)?;
-                st.variants = Variants::Single;
-
-                align = align.max(st.align);
-
-                Ok((j, st))
-            })
-            .collect::<Result<ArenaMap<_, _>, _>>()?;
-
-        let largest_variant_index = match variant_layouts
-            .iter()
-            .max_by_key(|(_i, layout)| layout.size.bytes())
-            .map(|(i, _layout)| i)
-        {
-            None => return Ok(None),
-            Some(i) => i,
-        };
-
-        let count = variants
-            .iter()
-            .map(|(i, _)| i)
-            .filter(|x| *x != largest_variant_index && !absent(&variants[*x]))
-            .count() as u128;
-
-        // Find the field with the largest niche
-        let (field_index, niche, (niche_start, niche_scalar)) = match 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)?)))
-        {
-            None => return Ok(None),
-            Some(x) => x,
-        };
-
-        let niche_offset =
-            niche.offset + variant_layouts[largest_variant_index].fields.offset(field_index, dl);
-        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_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 Ok(None);
-        }
-
-        let largest_niche = Niche::from_scalar(dl, niche_offset, niche_scalar);
-
-        let others_zst = variant_layouts
-            .iter()
-            .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 = Layout {
-            variants: Variants::Multiple {
-                tag: niche_scalar,
-                tag_encoding: TagEncoding::Niche {
-                    untagged_variant: largest_variant_index,
-                    niche_start,
-                },
-                tag_field: 0,
-                variants: ArenaMap::new(),
-            },
-            fields: FieldsShape::Arbitrary { offsets: vec![niche_offset], memory_index: vec![0] },
-            abi,
-            largest_niche,
-            size,
-            align,
-        };
-
-        Ok(Some(TmpLayout { layout, variants: variant_layouts }))
-    };
-
-    let niche_filling_layout = calculate_niche_filling_layout()?;
-
-    let (mut min, mut max) = (i128::MAX, i128::MIN);
-    // FIXME: bring these back
-    // let discr_type = repr.discr_type();
-    // let bits = Integer::from_attr(dl, discr_type).size().bits();
-    // for (i, discr) in def.discriminants(tcx) {
-    //     if variants[i].iter().any(|f| f.abi.is_uninhabited()) {
-    //         continue;
-    //     }
-    //     let mut x = discr.val as i128;
-    //     if discr_type.is_signed() {
-    //         // sign extend the raw representation to be an i128
-    //         x = (x << (128 - bits)) >> (128 - bits);
-    //     }
-    //     if x < min {
-    //         min = x;
-    //     }
-    //     if x > max {
-    //         max = x;
-    //     }
-    // }
-    // 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) = Integer::repr_discr(dl, &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.iter() {
-            for field in fields {
-                prefix_align = prefix_align.max(field.align.abi);
-            }
+                .collect::<Result<IndexVec<RustcEnumVariantIdx, _>, _>>()?;
+            (r, true, false, data.repr.unwrap_or_default())
         }
-    }
-
-    // Create the set of structs that represent each variant.
-    let mut layout_variants = variants
-        .iter()
-        .map(|(i, field_layouts)| {
-            let mut st = univariant(
-                dl,
-                &field_layouts,
-                &repr,
-                StructKind::Prefixed(min_ity.size(), prefix_align),
-            )?;
-            st.variants = Variants::Single;
-            // 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);
-            Ok((i, st))
-        })
-        .collect::<Result<ArenaMap<_, _>, _>>()?;
-
-    // Align the maximum variant size to the largest alignment.
-    size = size.align_to(align.abi);
-
-    if size.bytes() >= dl.obj_size_bound() {
-        return Err(LayoutError::SizeOverflow);
-    }
-
-    // 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.
-        // Patch up the variants' first few fields.
-        let old_ity_size = min_ity.size();
-        let new_ity_size = ity.size();
-        for (_, variant) in layout_variants.iter_mut() {
-            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;
-                    }
-                }
-                _ => user_error!("bug"),
-            }
-        }
-    }
-
-    let tag_mask = ity.size().unsigned_int_max();
-    let tag = Scalar::Initialized {
-        value: Primitive::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);
+    let variants = variants.iter().map(|x| x.iter().collect::<Vec<_>>()).collect::<Vec<_>>();
+    let variants = variants.iter().map(|x| x.iter().collect()).collect();
+    if is_union {
+        cx.layout_of_union(&repr, &variants).ok_or(LayoutError::Unknown)
     } 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.iter(), layout_variants.iter())
-        {
-            let offsets = match layout_variant.fields {
-                FieldsShape::Arbitrary { ref offsets, .. } => offsets,
-                _ => user_error!("bug"),
-            };
-            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(dl, prim)
-            } else {
-                // Common prim might be uninit.
-                Scalar::Union { value: prim }
-            };
-            let pair = scalar_pair(dl, tag, prim_scalar);
-            let pair_offsets = match pair.fields {
-                FieldsShape::Arbitrary { ref offsets, ref memory_index } => {
-                    assert_eq!(memory_index, &[0, 1]);
-                    offsets
-                }
-                _ => user_error!("bug"),
-            };
-            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 layout_variants.iter_mut() {
-            // 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);
-            }
-        }
+        cx.layout_of_struct_or_enum(
+            &repr,
+            &variants,
+            is_enum,
+            is_unsafe_cell(def, db),
+            layout_scalar_valid_range(db, def),
+            |min, max| Integer::repr_discr(&dl, &repr, min, max).unwrap_or((Integer::I8, false)),
+            variants.iter_enumerated().filter_map(|(id, _)| {
+                let AdtId::EnumId(e) = def else { return None };
+                let d = match db
+                    .const_eval_variant(EnumVariantId { parent: e, local_id: id.0 })
+                    .ok()?
+                {
+                    crate::consteval::ComputedExpr::Literal(l) => match l {
+                        hir_def::expr::Literal::Int(i, _) => i,
+                        hir_def::expr::Literal::Uint(i, _) => i as i128,
+                        _ => return None,
+                    },
+                    _ => return None,
+                };
+                Some((id, d))
+            }),
+            // FIXME: The current code for niche-filling relies on variant indices
+            // instead of actual discriminants, so enums with
+            // explicit discriminants (RFC #2363) would misbehave and we should disable
+            // niche optimization for them.
+            // The code that do it in rustc:
+            // repr.inhibit_enum_layout_opt() || def
+            //     .variants()
+            //     .iter_enumerated()
+            //     .any(|(i, v)| v.discr != ty::VariantDiscr::Relative(i.as_u32()))
+            repr.inhibit_enum_layout_opt(),
+            !is_enum
+                && variants
+                    .iter()
+                    .next()
+                    .and_then(|x| x.last().map(|x| x.is_unsized()))
+                    .unwrap_or(true),
+        )
+        .ok_or(LayoutError::SizeOverflow)
     }
-
-    let largest_niche = Niche::from_scalar(dl, Size::ZERO, tag);
-
-    let tagged_layout = Layout {
-        variants: Variants::Multiple {
-            tag,
-            tag_encoding: TagEncoding::Direct,
-            tag_field: 0,
-            variants: ArenaMap::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 Ordering::*;
-            let niche_size =
-                |tmp_l: &TmpLayout| 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 }
-        }
-        _ => user_error!("bug"),
-    };
-
-    Ok(best_layout.layout)
 }
 
 fn layout_scalar_valid_range(db: &dyn HirDatabase, def: AdtId) -> (Bound<u128>, Bound<u128>) {
@@ -649,302 +131,3 @@ pub fn layout_of_adt_recover(
 ) -> Result<Layout, LayoutError> {
     user_error!("infinite sized recursive type");
 }
-
-pub(crate) fn univariant(
-    dl: &TargetDataLayout,
-    fields: &[Layout],
-    repr: &ReprOptions,
-    kind: StructKind,
-) -> Result<Layout, LayoutError> {
-    let pack = repr.pack;
-    if pack.is_some() && repr.align.is_some() {
-        user_error!("Struct can not be packed and aligned");
-    }
-
-    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 field_align = |f: &Layout| {
-            if let Some(pack) = pack {
-                f.align.abi.min(pack)
-            } else {
-                f.align.abi
-            }
-        };
-
-        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.
-                    let f = &fields[x as usize];
-                    (!f.is_zst(), cmp::Reverse(field_align(f)))
-                });
-            }
-
-            StructKind::Prefixed(..) => {
-                // Sort in ascending alignment so that the layout stays optimal
-                // regardless of the prefix
-                optimizing.sort_by_key(|&x| field_align(&fields[x as usize]));
-            }
-        }
-    }
-
-    // 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 {
-            user_error!("Unsized field is not last field");
-        }
-
-        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);
-
-        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 =
-                    niche.offset.checked_add(offset, dl).ok_or(LayoutError::SizeOverflow)?;
-                largest_niche = Some(niche);
-            }
-        }
-
-        offset = offset.checked_add(field.size, dl).ok_or(LayoutError::SizeOverflow)?;
-    }
-
-    if let Some(repr_align) = repr.align {
-        align = align.max(AbiAndPrefAlign::new(repr_align));
-    }
-
-    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 = scalar_pair(dl, a, b);
-                        let pair_offsets = match pair.fields {
-                            FieldsShape::Arbitrary { ref offsets, .. } => offsets,
-                            _ => unreachable!(),
-                        };
-                        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;
-    }
-
-    Ok(Layout {
-        variants: Variants::Single,
-        fields: FieldsShape::Arbitrary { offsets, memory_index },
-        abi,
-        largest_niche,
-        align,
-        size,
-    })
-}
-
-fn layout_of_union(
-    db: &dyn HirDatabase,
-    id: UnionId,
-    subst: &Substitution,
-) -> Result<Layout, LayoutError> {
-    let dl = &*db.current_target_data_layout();
-
-    let union_data = db.union_data(id);
-
-    let repr = union_data.repr.unwrap_or_default();
-    let fields = union_data.variant_data.fields();
-
-    if repr.pack.is_some() && repr.align.is_some() {
-        user_error!("union cannot be packed and aligned");
-    }
-
-    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 };
-    for (fd, _) in fields.iter() {
-        let field_ty = field_ty(db, id.into(), fd, subst);
-        let field = layout_of_ty(db, &field_ty)?;
-        if field.is_unsized() {
-            user_error!("unsized union field");
-        }
-        // 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));
-    }
-
-    Ok(Layout {
-        variants: Variants::Single,
-        fields: FieldsShape::Union(
-            NonZeroUsize::new(fields.len())
-                .ok_or(LayoutError::UserError("union with zero fields".to_string()))?,
-        ),
-        abi,
-        largest_niche: None,
-        align,
-        size: size.align_to(align.abi),
-    })
-}
-
-// 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
-}
-
-fn scalar_pair(dl: &TargetDataLayout, a: Scalar, b: Scalar) -> Layout {
-    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.checked_add(b.size(dl), dl).unwrap().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));
-
-    Layout {
-        variants: Variants::Single,
-        fields: FieldsShape::Arbitrary {
-            offsets: vec![Size::ZERO, b_offset],
-            memory_index: vec![0, 1],
-        },
-        abi: Abi::ScalarPair(a, b),
-        largest_niche,
-        align,
-        size,
-    }
-}
diff --git a/crates/hir-ty/src/layout/target.rs b/crates/hir-ty/src/layout/target.rs
index ba810b12b1f..48b1a68d51b 100644
--- a/crates/hir-ty/src/layout/target.rs
+++ b/crates/hir-ty/src/layout/target.rs
@@ -35,7 +35,7 @@ pub fn current_target_data_layout_query(db: &dyn HirDatabase) -> Arc<TargetDataL
         f32_align: AbiAndPrefAlign::new(Align::from_bytes(4).unwrap()),
         f64_align: AbiAndPrefAlign::new(Align::from_bytes(8).unwrap()),
         pointer_size,
-        pointer_align: AbiAndPrefAlign::new(Align::from_bytes(8).unwrap()),
+        pointer_align: AbiAndPrefAlign::new(Align::from_bytes(pointer_size.bytes()).unwrap()),
         aggregate_align: AbiAndPrefAlign::new(Align::from_bytes(1).unwrap()),
         vector_align: vec![],
         instruction_address_space: AddressSpace(0),
diff --git a/crates/hir-ty/src/layout/tests.rs b/crates/hir-ty/src/layout/tests.rs
index 1cd6d4eae24..5d97a69501f 100644
--- a/crates/hir-ty/src/layout/tests.rs
+++ b/crates/hir-ty/src/layout/tests.rs
@@ -49,6 +49,17 @@ fn check_fail(ra_fixture: &str, e: LayoutError) {
 }
 
 macro_rules! size_and_align {
+    (minicore: $($x:tt),*;$($t:tt)*) => {
+        {
+            #[allow(dead_code)]
+            $($t)*
+            check_size_and_align(
+                &format!("//- minicore: {}\n{}", stringify!($($x),*), stringify!($($t)*)),
+                ::std::mem::size_of::<Goal>() as u64,
+                ::std::mem::align_of::<Goal>() as u64,
+            );
+        }
+    };
     ($($t:tt)*) => {
         {
             #[allow(dead_code)]
@@ -67,7 +78,6 @@ fn hello_world() {
     size_and_align! {
         struct Goal(i32);
     }
-    //check_size_and_align(r#"struct Goal(i32)"#, 4, 4);
 }
 
 #[test]
@@ -148,33 +158,39 @@ fn tuple() {
 
 #[test]
 fn non_zero() {
-    check_size_and_align(
-        r#"
-    //- minicore: non_zero, option
-    use core::num::NonZeroU8;
-    struct Goal(Option<NonZeroU8>);
-    "#,
-        1,
-        1,
-    );
+    size_and_align! {
+        minicore: non_zero, option;
+        use core::num::NonZeroU8;
+        struct Goal(Option<NonZeroU8>);
+    }
 }
 
 #[test]
 fn niche_optimization() {
-    check_size_and_align(
-        r#"
-    //- minicore: option
-    struct Goal(Option<&i32>);
-    "#,
-        8,
-        8,
-    );
-    check_size_and_align(
-        r#"
-    //- minicore: option
-    struct Goal(Option<Option<bool>>);
-    "#,
-        1,
-        1,
-    );
+    size_and_align! {
+        minicore: option;
+        struct Goal(Option<&'static i32>);
+    }
+    size_and_align! {
+        minicore: option;
+        struct Goal(Option<Option<bool>>);
+    }
+}
+
+#[test]
+fn enums_with_discriminants() {
+    size_and_align! {
+        enum Goal {
+            A = 1000,
+            B = 2000,
+            C = 3000,
+        }
+    }
+    size_and_align! {
+        enum Goal {
+            A = 254,
+            B,
+            C, // implicitly becomes 256, so we need two bytes
+        }
+    }
 }
diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index 42b7c0781bf..1b540915395 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -994,8 +994,30 @@ impl Enum {
         Type::new_for_crate(
             self.id.lookup(db.upcast()).container.krate(),
             TyBuilder::builtin(match db.enum_data(self.id).variant_body_type() {
-                Either::Left(builtin) => hir_def::builtin_type::BuiltinType::Int(builtin),
-                Either::Right(builtin) => hir_def::builtin_type::BuiltinType::Uint(builtin),
+                hir_def::layout::IntegerType::Pointer(sign) => match sign {
+                    true => hir_def::builtin_type::BuiltinType::Int(
+                        hir_def::builtin_type::BuiltinInt::Isize,
+                    ),
+                    false => hir_def::builtin_type::BuiltinType::Uint(
+                        hir_def::builtin_type::BuiltinUint::Usize,
+                    ),
+                },
+                hir_def::layout::IntegerType::Fixed(i, sign) => match sign {
+                    true => hir_def::builtin_type::BuiltinType::Int(match i {
+                        hir_def::layout::Integer::I8 => hir_def::builtin_type::BuiltinInt::I8,
+                        hir_def::layout::Integer::I16 => hir_def::builtin_type::BuiltinInt::I16,
+                        hir_def::layout::Integer::I32 => hir_def::builtin_type::BuiltinInt::I32,
+                        hir_def::layout::Integer::I64 => hir_def::builtin_type::BuiltinInt::I64,
+                        hir_def::layout::Integer::I128 => hir_def::builtin_type::BuiltinInt::I128,
+                    }),
+                    false => hir_def::builtin_type::BuiltinType::Uint(match i {
+                        hir_def::layout::Integer::I8 => hir_def::builtin_type::BuiltinUint::U8,
+                        hir_def::layout::Integer::I16 => hir_def::builtin_type::BuiltinUint::U16,
+                        hir_def::layout::Integer::I32 => hir_def::builtin_type::BuiltinUint::U32,
+                        hir_def::layout::Integer::I64 => hir_def::builtin_type::BuiltinUint::U64,
+                        hir_def::layout::Integer::I128 => hir_def::builtin_type::BuiltinUint::U128,
+                    }),
+                },
             }),
         )
     }
diff --git a/crates/ide/src/hover/render.rs b/crates/ide/src/hover/render.rs
index 470c6626f9d..f37c9f4a6d5 100644
--- a/crates/ide/src/hover/render.rs
+++ b/crates/ide/src/hover/render.rs
@@ -3,8 +3,7 @@ use std::fmt::Display;
 
 use either::Either;
 use hir::{
-    db::HirDatabase, Adt, AsAssocItem, AttributeTemplate, HasAttrs, HasSource, HirDisplay,
-    Semantics, TypeInfo,
+    Adt, AsAssocItem, AttributeTemplate, HasAttrs, HasSource, HirDisplay, Semantics, TypeInfo,
 };
 use ide_db::{
     base_db::SourceDatabase,
@@ -398,7 +397,7 @@ pub(super) fn definition(
             let offset = match var_def {
                 hir::VariantDef::Struct(s) => {
                     let layout = Adt::from(s).layout(db).ok()?;
-                    layout.fields.offset(id, &db.current_target_data_layout())
+                    layout.fields.offset(id)
                 }
                 _ => return None,
             };
diff --git a/crates/ide/src/hover/tests.rs b/crates/ide/src/hover/tests.rs
index f630c3b36dc..f82fd6d0289 100644
--- a/crates/ide/src/hover/tests.rs
+++ b/crates/ide/src/hover/tests.rs
@@ -537,7 +537,7 @@ struct Foo { fiel$0d_a: u8, field_b: i32, field_c: i16 }
             ```
 
             ```rust
-            field_a: u8 // size = 1, align = 1, offset = 6
+            field_a: u8 // size = 1, align = 1, offset = 4
             ```
         "#]],
     );