interpret: make write functions generic over the place type

26 files changed, 240 insertions, 210 deletions

diff --git a/compiler/rustc_const_eval/src/const_eval/valtrees.rs b/compiler/rustc_const_eval/src/const_eval/valtrees.rs
index b519bcdf4a3..61aace8d3ea 100644
--- a/compiler/rustc_const_eval/src/const_eval/valtrees.rs
+++ b/compiler/rustc_const_eval/src/const_eval/valtrees.rs
@@ -345,7 +345,7 @@ fn valtree_into_mplace<'tcx>(
         ty::Bool | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Char => {
             let scalar_int = valtree.unwrap_leaf();
             debug!("writing trivial valtree {:?} to place {:?}", scalar_int, place);
-            ecx.write_immediate(Immediate::Scalar(scalar_int.into()), &place.into()).unwrap();
+            ecx.write_immediate(Immediate::Scalar(scalar_int.into()), place).unwrap();
         }
         ty::Ref(_, inner_ty, _) => {
             let mut pointee_place = create_pointee_place(ecx, *inner_ty, valtree);
@@ -369,7 +369,7 @@ fn valtree_into_mplace<'tcx>(
             };
             debug!(?imm);
 
-            ecx.write_immediate(imm, &place.into()).unwrap();
+            ecx.write_immediate(imm, place).unwrap();
         }
         ty::Adt(_, _) | ty::Tuple(_) | ty::Array(_, _) | ty::Str | ty::Slice(_) => {
             let branches = valtree.unwrap_branch();
@@ -452,11 +452,11 @@ fn valtree_into_mplace<'tcx>(
 
             if let Some(variant_idx) = variant_idx {
                 // don't forget filling the place with the discriminant of the enum
-                ecx.write_discriminant(variant_idx, &place.into()).unwrap();
+                ecx.write_discriminant(variant_idx, place).unwrap();
             }
 
             debug!("dump of place after writing discriminant:");
-            dump_place(ecx, place.into());
+            dump_place(ecx, place.clone().into());
         }
         _ => bug!("shouldn't have created a ValTree for {:?}", ty),
     }
diff --git a/compiler/rustc_const_eval/src/interpret/discriminant.rs b/compiler/rustc_const_eval/src/interpret/discriminant.rs
index aff86d5f486..b6584daf23d 100644
--- a/compiler/rustc_const_eval/src/interpret/discriminant.rs
+++ b/compiler/rustc_const_eval/src/interpret/discriminant.rs
@@ -5,7 +5,8 @@ use rustc_middle::{mir, ty};
 use rustc_target::abi::{self, TagEncoding};
 use rustc_target::abi::{VariantIdx, Variants};
 
-use super::{ImmTy, InterpCx, InterpResult, Machine, OpTy, PlaceTy, Scalar};
+use super::place::Writeable;
+use super::{ImmTy, InterpCx, InterpResult, Machine, OpTy, Scalar};
 
 impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
     /// Writes the discriminant of the given variant.
@@ -13,7 +14,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
     pub fn write_discriminant(
         &mut self,
         variant_index: VariantIdx,
-        dest: &PlaceTy<'tcx, M::Provenance>,
+        dest: &impl Writeable<'tcx, M::Provenance>,
     ) -> InterpResult<'tcx> {
         // Layout computation excludes uninhabited variants from consideration
         // therefore there's no way to represent those variants in the given layout.
@@ -21,11 +22,11 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         // discriminant, so we cannot do anything here.
         // When evaluating we will always error before even getting here, but ConstProp 'executes'
         // dead code, so we cannot ICE here.
-        if dest.layout.for_variant(self, variant_index).abi.is_uninhabited() {
+        if dest.layout().for_variant(self, variant_index).abi.is_uninhabited() {
             throw_ub!(UninhabitedEnumVariantWritten(variant_index))
         }
 
-        match dest.layout.variants {
+        match dest.layout().variants {
             abi::Variants::Single { index } => {
                 assert_eq!(index, variant_index);
             }
@@ -38,8 +39,12 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 // No need to validate that the discriminant here because the
                 // `TyAndLayout::for_variant()` call earlier already checks the variant is valid.
 
-                let discr_val =
-                    dest.layout.ty.discriminant_for_variant(*self.tcx, variant_index).unwrap().val;
+                let discr_val = dest
+                    .layout()
+                    .ty
+                    .discriminant_for_variant(*self.tcx, variant_index)
+                    .unwrap()
+                    .val;
 
                 // raw discriminants for enums are isize or bigger during
                 // their computation, but the in-memory tag is the smallest possible
diff --git a/compiler/rustc_const_eval/src/interpret/intrinsics.rs b/compiler/rustc_const_eval/src/interpret/intrinsics.rs
index 3f697168280..9eb4c290495 100644
--- a/compiler/rustc_const_eval/src/interpret/intrinsics.rs
+++ b/compiler/rustc_const_eval/src/interpret/intrinsics.rs
@@ -432,7 +432,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                     } else {
                         self.project_index(&input, i)?.into()
                     };
-                    self.copy_op(&value, &place.into(), /*allow_transmute*/ false)?;
+                    self.copy_op(&value, &place, /*allow_transmute*/ false)?;
                 }
             }
             sym::simd_extract => {
diff --git a/compiler/rustc_const_eval/src/interpret/intrinsics/caller_location.rs b/compiler/rustc_const_eval/src/interpret/intrinsics/caller_location.rs
index 44a12751743..948bec7464a 100644
--- a/compiler/rustc_const_eval/src/interpret/intrinsics/caller_location.rs
+++ b/compiler/rustc_const_eval/src/interpret/intrinsics/caller_location.rs
@@ -101,11 +101,11 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         let location = self.allocate(loc_layout, MemoryKind::CallerLocation).unwrap();
 
         // Initialize fields.
-        self.write_immediate(file.to_ref(self), &self.project_field(&location, 0).unwrap().into())
+        self.write_immediate(file.to_ref(self), &self.project_field(&location, 0).unwrap())
             .expect("writing to memory we just allocated cannot fail");
-        self.write_scalar(line, &self.project_field(&location, 1).unwrap().into())
+        self.write_scalar(line, &self.project_field(&location, 1).unwrap())
             .expect("writing to memory we just allocated cannot fail");
-        self.write_scalar(col, &self.project_field(&location, 2).unwrap().into())
+        self.write_scalar(col, &self.project_field(&location, 2).unwrap())
             .expect("writing to memory we just allocated cannot fail");
 
         location
diff --git a/compiler/rustc_const_eval/src/interpret/mod.rs b/compiler/rustc_const_eval/src/interpret/mod.rs
index 7974920bc14..de5c6358963 100644
--- a/compiler/rustc_const_eval/src/interpret/mod.rs
+++ b/compiler/rustc_const_eval/src/interpret/mod.rs
@@ -25,7 +25,7 @@ pub use self::intern::{intern_const_alloc_recursive, InternKind};
 pub use self::machine::{compile_time_machine, AllocMap, Machine, MayLeak, StackPopJump};
 pub use self::memory::{AllocKind, AllocRef, AllocRefMut, FnVal, Memory, MemoryKind};
 pub use self::operand::{ImmTy, Immediate, OpTy, Operand};
-pub use self::place::{MPlaceTy, MemPlace, MemPlaceMeta, Place, PlaceTy};
+pub use self::place::{MPlaceTy, MemPlace, MemPlaceMeta, Place, PlaceTy, Writeable};
 pub use self::projection::Projectable;
 pub use self::terminator::FnArg;
 pub use self::validity::{CtfeValidationMode, RefTracking};
diff --git a/compiler/rustc_const_eval/src/interpret/operand.rs b/compiler/rustc_const_eval/src/interpret/operand.rs
index be39e63ab4f..828f9e019af 100644
--- a/compiler/rustc_const_eval/src/interpret/operand.rs
+++ b/compiler/rustc_const_eval/src/interpret/operand.rs
@@ -312,13 +312,13 @@ impl<'tcx, Prov: Provenance> ImmTy<'tcx, Prov> {
     }
 }
 
-impl<'mir, 'tcx: 'mir, Prov: Provenance> Projectable<'mir, 'tcx, Prov> for ImmTy<'tcx, Prov> {
+impl<'tcx, Prov: Provenance> Projectable<'tcx, Prov> for ImmTy<'tcx, Prov> {
     #[inline(always)]
     fn layout(&self) -> TyAndLayout<'tcx> {
         self.layout
     }
 
-    fn meta<M: Machine<'mir, 'tcx, Provenance = Prov>>(
+    fn meta<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>(
         &self,
         _ecx: &InterpCx<'mir, 'tcx, M>,
     ) -> InterpResult<'tcx, MemPlaceMeta<M::Provenance>> {
@@ -337,7 +337,7 @@ impl<'mir, 'tcx: 'mir, Prov: Provenance> Projectable<'mir, 'tcx, Prov> for ImmTy
         Ok(self.offset_(offset, layout, cx))
     }
 
-    fn to_op<M: Machine<'mir, 'tcx, Provenance = Prov>>(
+    fn to_op<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>(
         &self,
         _ecx: &InterpCx<'mir, 'tcx, M>,
     ) -> InterpResult<'tcx, OpTy<'tcx, M::Provenance>> {
@@ -362,15 +362,13 @@ impl<'tcx, Prov: Provenance> OpTy<'tcx, Prov> {
     }
 }
 
-impl<'mir, 'tcx: 'mir, Prov: Provenance + 'static> Projectable<'mir, 'tcx, Prov>
-    for OpTy<'tcx, Prov>
-{
+impl<'tcx, Prov: Provenance + 'static> Projectable<'tcx, Prov> for OpTy<'tcx, Prov> {
     #[inline(always)]
     fn layout(&self) -> TyAndLayout<'tcx> {
         self.layout
     }
 
-    fn meta<M: Machine<'mir, 'tcx, Provenance = Prov>>(
+    fn meta<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>(
         &self,
         _ecx: &InterpCx<'mir, 'tcx, M>,
     ) -> InterpResult<'tcx, MemPlaceMeta<M::Provenance>> {
@@ -394,7 +392,7 @@ impl<'mir, 'tcx: 'mir, Prov: Provenance + 'static> Projectable<'mir, 'tcx, Prov>
         }
     }
 
-    fn to_op<M: Machine<'mir, 'tcx, Provenance = Prov>>(
+    fn to_op<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>(
         &self,
         _ecx: &InterpCx<'mir, 'tcx, M>,
     ) -> InterpResult<'tcx, OpTy<'tcx, M::Provenance>> {
diff --git a/compiler/rustc_const_eval/src/interpret/place.rs b/compiler/rustc_const_eval/src/interpret/place.rs
index db1239c7136..407b7296c72 100644
--- a/compiler/rustc_const_eval/src/interpret/place.rs
+++ b/compiler/rustc_const_eval/src/interpret/place.rs
@@ -92,6 +92,14 @@ pub struct MPlaceTy<'tcx, Prov: Provenance = AllocId> {
     pub align: Align,
 }
 
+impl<'tcx, Prov: Provenance> std::ops::Deref for MPlaceTy<'tcx, Prov> {
+    type Target = MemPlace<Prov>;
+    #[inline(always)]
+    fn deref(&self) -> &MemPlace<Prov> {
+        &self.mplace
+    }
+}
+
 #[derive(Copy, Clone, Debug)]
 pub enum Place<Prov: Provenance = AllocId> {
     /// A place referring to a value allocated in the `Memory` system.
@@ -125,14 +133,6 @@ impl<'tcx, Prov: Provenance> std::ops::Deref for PlaceTy<'tcx, Prov> {
     }
 }
 
-impl<'tcx, Prov: Provenance> std::ops::Deref for MPlaceTy<'tcx, Prov> {
-    type Target = MemPlace<Prov>;
-    #[inline(always)]
-    fn deref(&self) -> &MemPlace<Prov> {
-        &self.mplace
-    }
-}
-
 impl<'tcx, Prov: Provenance> From<MPlaceTy<'tcx, Prov>> for PlaceTy<'tcx, Prov> {
     #[inline(always)]
     fn from(mplace: MPlaceTy<'tcx, Prov>) -> Self {
@@ -140,20 +140,6 @@ impl<'tcx, Prov: Provenance> From<MPlaceTy<'tcx, Prov>> for PlaceTy<'tcx, Prov>
     }
 }
 
-impl<'tcx, Prov: Provenance> From<&'_ MPlaceTy<'tcx, Prov>> for PlaceTy<'tcx, Prov> {
-    #[inline(always)]
-    fn from(mplace: &MPlaceTy<'tcx, Prov>) -> Self {
-        PlaceTy { place: Place::Ptr(**mplace), layout: mplace.layout, align: mplace.align }
-    }
-}
-
-impl<'tcx, Prov: Provenance> From<&'_ mut MPlaceTy<'tcx, Prov>> for PlaceTy<'tcx, Prov> {
-    #[inline(always)]
-    fn from(mplace: &mut MPlaceTy<'tcx, Prov>) -> Self {
-        PlaceTy { place: Place::Ptr(**mplace), layout: mplace.layout, align: mplace.align }
-    }
-}
-
 impl<Prov: Provenance> MemPlace<Prov> {
     #[inline(always)]
     pub fn from_ptr(ptr: Pointer<Option<Prov>>) -> Self {
@@ -229,15 +215,13 @@ impl<'tcx, Prov: Provenance> MPlaceTy<'tcx, Prov> {
     }
 }
 
-impl<'mir, 'tcx: 'mir, Prov: Provenance + 'static> Projectable<'mir, 'tcx, Prov>
-    for MPlaceTy<'tcx, Prov>
-{
+impl<'tcx, Prov: Provenance + 'static> Projectable<'tcx, Prov> for MPlaceTy<'tcx, Prov> {
     #[inline(always)]
     fn layout(&self) -> TyAndLayout<'tcx> {
         self.layout
     }
 
-    fn meta<M: Machine<'mir, 'tcx, Provenance = Prov>>(
+    fn meta<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>(
         &self,
         _ecx: &InterpCx<'mir, 'tcx, M>,
     ) -> InterpResult<'tcx, MemPlaceMeta<M::Provenance>> {
@@ -258,7 +242,7 @@ impl<'mir, 'tcx: 'mir, Prov: Provenance + 'static> Projectable<'mir, 'tcx, Prov>
         })
     }
 
-    fn to_op<M: Machine<'mir, 'tcx, Provenance = Prov>>(
+    fn to_op<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>(
         &self,
         _ecx: &InterpCx<'mir, 'tcx, M>,
     ) -> InterpResult<'tcx, OpTy<'tcx, M::Provenance>> {
@@ -266,6 +250,54 @@ impl<'mir, 'tcx: 'mir, Prov: Provenance + 'static> Projectable<'mir, 'tcx, Prov>
     }
 }
 
+impl<'tcx, Prov: Provenance + 'static> Projectable<'tcx, Prov> for PlaceTy<'tcx, Prov> {
+    #[inline(always)]
+    fn layout(&self) -> TyAndLayout<'tcx> {
+        self.layout
+    }
+
+    fn meta<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>(
+        &self,
+        ecx: &InterpCx<'mir, 'tcx, M>,
+    ) -> InterpResult<'tcx, MemPlaceMeta<M::Provenance>> {
+        ecx.place_meta(self)
+    }
+
+    fn offset_with_meta(
+        &self,
+        offset: Size,
+        meta: MemPlaceMeta<Prov>,
+        layout: TyAndLayout<'tcx>,
+        cx: &impl HasDataLayout,
+    ) -> InterpResult<'tcx, Self> {
+        Ok(match self.as_mplace_or_local() {
+            Left(mplace) => mplace.offset_with_meta(offset, meta, layout, cx)?.into(),
+            Right((frame, local, old_offset)) => {
+                assert_matches!(meta, MemPlaceMeta::None); // we couldn't store it anyway...
+                let new_offset = cx
+                    .data_layout()
+                    .offset(old_offset.unwrap_or(Size::ZERO).bytes(), offset.bytes())?;
+                PlaceTy {
+                    place: Place::Local {
+                        frame,
+                        local,
+                        offset: Some(Size::from_bytes(new_offset)),
+                    },
+                    align: self.align.restrict_for_offset(offset),
+                    layout,
+                }
+            }
+        })
+    }
+
+    fn to_op<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>(
+        &self,
+        ecx: &InterpCx<'mir, 'tcx, M>,
+    ) -> InterpResult<'tcx, OpTy<'tcx, M::Provenance>> {
+        ecx.place_to_op(self)
+    }
+}
+
 // These are defined here because they produce a place.
 impl<'tcx, Prov: Provenance> OpTy<'tcx, Prov> {
     #[inline(always)]
@@ -314,53 +346,51 @@ impl<'tcx, Prov: Provenance + 'static> PlaceTy<'tcx, Prov> {
     }
 }
 
-impl<'mir, 'tcx: 'mir, Prov: Provenance + 'static> Projectable<'mir, 'tcx, Prov>
-    for PlaceTy<'tcx, Prov>
-{
+pub trait Writeable<'tcx, Prov: Provenance>: Projectable<'tcx, Prov> {
+    fn as_mplace_or_local(
+        &self,
+    ) -> Either<MPlaceTy<'tcx, Prov>, (usize, mir::Local, Option<Size>, Align, TyAndLayout<'tcx>)>;
+
+    fn force_mplace<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>(
+        &self,
+        ecx: &mut InterpCx<'mir, 'tcx, M>,
+    ) -> InterpResult<'tcx, MPlaceTy<'tcx, Prov>>;
+}
+
+impl<'tcx, Prov: Provenance + 'static> Writeable<'tcx, Prov> for PlaceTy<'tcx, Prov> {
     #[inline(always)]
-    fn layout(&self) -> TyAndLayout<'tcx> {
-        self.layout
+    fn as_mplace_or_local(
+        &self,
+    ) -> Either<MPlaceTy<'tcx, Prov>, (usize, mir::Local, Option<Size>, Align, TyAndLayout<'tcx>)>
+    {
+        self.as_mplace_or_local()
+            .map_right(|(frame, local, offset)| (frame, local, offset, self.align, self.layout))
     }
 
-    fn meta<M: Machine<'mir, 'tcx, Provenance = Prov>>(
+    #[inline(always)]
+    fn force_mplace<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>(
         &self,
-        ecx: &InterpCx<'mir, 'tcx, M>,
-    ) -> InterpResult<'tcx, MemPlaceMeta<M::Provenance>> {
-        ecx.place_meta(self)
+        ecx: &mut InterpCx<'mir, 'tcx, M>,
+    ) -> InterpResult<'tcx, MPlaceTy<'tcx, Prov>> {
+        ecx.force_allocation(self)
     }
+}
 
-    fn offset_with_meta(
+impl<'tcx, Prov: Provenance + 'static> Writeable<'tcx, Prov> for MPlaceTy<'tcx, Prov> {
+    #[inline(always)]
+    fn as_mplace_or_local(
         &self,
-        offset: Size,
-        meta: MemPlaceMeta<Prov>,
-        layout: TyAndLayout<'tcx>,
-        cx: &impl HasDataLayout,
-    ) -> InterpResult<'tcx, Self> {
-        Ok(match self.as_mplace_or_local() {
-            Left(mplace) => mplace.offset_with_meta(offset, meta, layout, cx)?.into(),
-            Right((frame, local, old_offset)) => {
-                assert_matches!(meta, MemPlaceMeta::None); // we couldn't store it anyway...
-                let new_offset = cx
-                    .data_layout()
-                    .offset(old_offset.unwrap_or(Size::ZERO).bytes(), offset.bytes())?;
-                PlaceTy {
-                    place: Place::Local {
-                        frame,
-                        local,
-                        offset: Some(Size::from_bytes(new_offset)),
-                    },
-                    align: self.align.restrict_for_offset(offset),
-                    layout,
-                }
-            }
-        })
+    ) -> Either<MPlaceTy<'tcx, Prov>, (usize, mir::Local, Option<Size>, Align, TyAndLayout<'tcx>)>
+    {
+        Left(self.clone())
     }
 
-    fn to_op<M: Machine<'mir, 'tcx, Provenance = Prov>>(
+    #[inline(always)]
+    fn force_mplace<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>(
         &self,
-        ecx: &InterpCx<'mir, 'tcx, M>,
-    ) -> InterpResult<'tcx, OpTy<'tcx, M::Provenance>> {
-        ecx.place_to_op(self)
+        _ecx: &mut InterpCx<'mir, 'tcx, M>,
+    ) -> InterpResult<'tcx, MPlaceTy<'tcx, Prov>> {
+        Ok(self.clone())
     }
 }
 
@@ -537,13 +567,13 @@ where
     pub fn write_immediate(
         &mut self,
         src: Immediate<M::Provenance>,
-        dest: &PlaceTy<'tcx, M::Provenance>,
+        dest: &impl Writeable<'tcx, M::Provenance>,
     ) -> InterpResult<'tcx> {
         self.write_immediate_no_validate(src, dest)?;
 
-        if M::enforce_validity(self, dest.layout) {
+        if M::enforce_validity(self, dest.layout()) {
             // Data got changed, better make sure it matches the type!
-            self.validate_operand(&self.place_to_op(dest)?)?;
+            self.validate_operand(&dest.to_op(self)?)?;
         }
 
         Ok(())
@@ -554,7 +584,7 @@ where
     pub fn write_scalar(
         &mut self,
         val: impl Into<Scalar<M::Provenance>>,
-        dest: &PlaceTy<'tcx, M::Provenance>,
+        dest: &impl Writeable<'tcx, M::Provenance>,
     ) -> InterpResult<'tcx> {
         self.write_immediate(Immediate::Scalar(val.into()), dest)
     }
@@ -564,7 +594,7 @@ where
     pub fn write_pointer(
         &mut self,
         ptr: impl Into<Pointer<Option<M::Provenance>>>,
-        dest: &PlaceTy<'tcx, M::Provenance>,
+        dest: &impl Writeable<'tcx, M::Provenance>,
     ) -> InterpResult<'tcx> {
         self.write_scalar(Scalar::from_maybe_pointer(ptr.into(), self), dest)
     }
@@ -575,20 +605,19 @@ where
     fn write_immediate_no_validate(
         &mut self,
         src: Immediate<M::Provenance>,
-        dest: &PlaceTy<'tcx, M::Provenance>,
+        dest: &impl Writeable<'tcx, M::Provenance>,
     ) -> InterpResult<'tcx> {
-        assert!(dest.layout.is_sized(), "Cannot write unsized immediate data");
-        trace!("write_immediate: {:?} <- {:?}: {}", *dest, src, dest.layout.ty);
+        assert!(dest.layout().is_sized(), "Cannot write unsized immediate data");
 
         // See if we can avoid an allocation. This is the counterpart to `read_immediate_raw`,
         // but not factored as a separate function.
-        let mplace = match dest.place {
-            Place::Local { frame, local, offset } => {
+        let mplace = match dest.as_mplace_or_local() {
+            Right((frame, local, offset, align, layout)) => {
                 if offset.is_some() {
                     // This has been projected to a part of this local. We could have complicated
                     // logic to still keep this local as an `Operand`... but it's much easier to
                     // just fall back to the indirect path.
-                    *self.force_allocation(dest)?
+                    dest.force_mplace(self)?
                 } else {
                     match M::access_local_mut(self, frame, local)? {
                         Operand::Immediate(local_val) => {
@@ -623,16 +652,16 @@ where
                         }
                         Operand::Indirect(mplace) => {
                             // The local is in memory, go on below.
-                            *mplace
+                            MPlaceTy { mplace: *mplace, align, layout }
                         }
                     }
                 }
             }
-            Place::Ptr(mplace) => mplace, // already referring to memory
+            Left(mplace) => mplace, // already referring to memory
         };
 
         // This is already in memory, write there.
-        self.write_immediate_to_mplace_no_validate(src, dest.layout, dest.align, mplace)
+        self.write_immediate_to_mplace_no_validate(src, mplace.layout, mplace.align, mplace.mplace)
     }
 
     /// Write an immediate to memory.
@@ -696,16 +725,19 @@ where
         }
     }
 
-    pub fn write_uninit(&mut self, dest: &PlaceTy<'tcx, M::Provenance>) -> InterpResult<'tcx> {
+    pub fn write_uninit(
+        &mut self,
+        dest: &impl Writeable<'tcx, M::Provenance>,
+    ) -> InterpResult<'tcx> {
         let mplace = match dest.as_mplace_or_local() {
             Left(mplace) => mplace,
-            Right((frame, local, offset)) => {
+            Right((frame, local, offset, align, layout)) => {
                 if offset.is_some() {
                     // This has been projected to a part of this local. We could have complicated
                     // logic to still keep this local as an `Operand`... but it's much easier to
                     // just fall back to the indirect path.
                     // FIXME: share the logic with `write_immediate_no_validate`.
-                    self.force_allocation(dest)?
+                    dest.force_mplace(self)?
                 } else {
                     match M::access_local_mut(self, frame, local)? {
                         Operand::Immediate(local) => {
@@ -714,7 +746,7 @@ where
                         }
                         Operand::Indirect(mplace) => {
                             // The local is in memory, go on below.
-                            MPlaceTy { mplace: *mplace, layout: dest.layout, align: dest.align }
+                            MPlaceTy { mplace: *mplace, layout, align }
                         }
                     }
                 }
@@ -735,14 +767,14 @@ where
     pub fn copy_op(
         &mut self,
         src: &OpTy<'tcx, M::Provenance>,
-        dest: &PlaceTy<'tcx, M::Provenance>,
+        dest: &impl Writeable<'tcx, M::Provenance>,
         allow_transmute: bool,
     ) -> InterpResult<'tcx> {
         self.copy_op_no_validate(src, dest, allow_transmute)?;
 
-        if M::enforce_validity(self, dest.layout) {
+        if M::enforce_validity(self, dest.layout()) {
             // Data got changed, better make sure it matches the type!
-            self.validate_operand(&self.place_to_op(dest)?)?;
+            self.validate_operand(&dest.to_op(self)?)?;
         }
 
         Ok(())
@@ -756,19 +788,19 @@ where
     fn copy_op_no_validate(
         &mut self,
         src: &OpTy<'tcx, M::Provenance>,
-        dest: &PlaceTy<'tcx, M::Provenance>,
+        dest: &impl Writeable<'tcx, M::Provenance>,
         allow_transmute: bool,
     ) -> InterpResult<'tcx> {
         // We do NOT compare the types for equality, because well-typed code can
         // actually "transmute" `&mut T` to `&T` in an assignment without a cast.
         let layout_compat =
-            mir_assign_valid_types(*self.tcx, self.param_env, src.layout, dest.layout);
+            mir_assign_valid_types(*self.tcx, self.param_env, src.layout, dest.layout());
         if !allow_transmute && !layout_compat {
             span_bug!(
                 self.cur_span(),
                 "type mismatch when copying!\nsrc: {:?},\ndest: {:?}",
                 src.layout.ty,
-                dest.layout.ty,
+                dest.layout().ty,
             );
         }
 
@@ -784,10 +816,10 @@ where
                 if src.layout.is_unsized() {
                     throw_inval!(SizeOfUnsizedType(src.layout.ty));
                 }
-                if dest.layout.is_unsized() {
-                    throw_inval!(SizeOfUnsizedType(dest.layout.ty));
+                if dest.layout().is_unsized() {
+                    throw_inval!(SizeOfUnsizedType(dest.layout().ty));
                 }
-                assert_eq!(src.layout.size, dest.layout.size);
+                assert_eq!(src.layout.size, dest.layout().size);
                 // Yay, we got a value that we can write directly.
                 return if layout_compat {
                     self.write_immediate_no_validate(*src_val, dest)
@@ -796,7 +828,7 @@ where
                     // loaded using the offsets defined by `src.layout`. When we put this back into
                     // the destination, we have to use the same offsets! So (a) we make sure we
                     // write back to memory, and (b) we use `dest` *with the source layout*.
-                    let dest_mem = self.force_allocation(dest)?;
+                    let dest_mem = dest.force_mplace(self)?;
                     self.write_immediate_to_mplace_no_validate(
                         *src_val,
                         src.layout,
@@ -808,9 +840,9 @@ where
             Left(mplace) => mplace,
         };
         // Slow path, this does not fit into an immediate. Just memcpy.
-        trace!("copy_op: {:?} <- {:?}: {}", *dest, src, dest.layout.ty);
+        trace!("copy_op: {:?} <- {:?}: {}", *dest, src, dest.layout().ty);
 
-        let dest = self.force_allocation(&dest)?;
+        let dest = dest.force_mplace(self)?;
         let Some((dest_size, _)) = self.size_and_align_of_mplace(&dest)? else {
             span_bug!(self.cur_span(), "copy_op needs (dynamically) sized values")
         };
@@ -928,7 +960,7 @@ where
         operands: &IndexSlice<FieldIdx, mir::Operand<'tcx>>,
         dest: &PlaceTy<'tcx, M::Provenance>,
     ) -> InterpResult<'tcx> {
-        self.write_uninit(&dest)?;
+        self.write_uninit(dest)?;
         let (variant_index, variant_dest, active_field_index) = match *kind {
             mir::AggregateKind::Adt(_, variant_index, _, _, active_field_index) => {
                 let variant_dest = self.project_downcast(dest, variant_index)?;
@@ -945,7 +977,7 @@ where
             let op = self.eval_operand(operand, Some(field_dest.layout))?;
             self.copy_op(&op, &field_dest, /*allow_transmute*/ false)?;
         }
-        self.write_discriminant(variant_index, &dest)
+        self.write_discriminant(variant_index, dest)
     }
 
     pub fn raw_const_to_mplace(
@@ -983,7 +1015,7 @@ where
 
     /// Turn a `dyn* Trait` type into an value with the actual dynamic type.
     /// Also returns the vtable.
-    pub(super) fn unpack_dyn_star<P: Projectable<'mir, 'tcx, M::Provenance>>(
+    pub(super) fn unpack_dyn_star<P: Projectable<'tcx, M::Provenance>>(
         &self,
         val: &P,
     ) -> InterpResult<'tcx, (P, Pointer<Option<M::Provenance>>)> {
diff --git a/compiler/rustc_const_eval/src/interpret/projection.rs b/compiler/rustc_const_eval/src/interpret/projection.rs
index ddcbc8350aa..bce43aedb69 100644
--- a/compiler/rustc_const_eval/src/interpret/projection.rs
+++ b/compiler/rustc_const_eval/src/interpret/projection.rs
@@ -16,21 +16,20 @@ use rustc_target::abi::HasDataLayout;
 use rustc_target::abi::Size;
 use rustc_target::abi::{self, VariantIdx};
 
-use super::MPlaceTy;
-use super::{InterpCx, InterpResult, Machine, MemPlaceMeta, OpTy, Provenance, Scalar};
+use super::{InterpCx, InterpResult, MPlaceTy, Machine, MemPlaceMeta, OpTy, Provenance, Scalar};
 
 /// A thing that we can project into, and that has a layout.
-pub trait Projectable<'mir, 'tcx: 'mir, Prov: Provenance>: Sized {
+pub trait Projectable<'tcx, Prov: Provenance>: Sized + std::fmt::Debug {
     /// Get the layout.
     fn layout(&self) -> TyAndLayout<'tcx>;
 
     /// Get the metadata of a wide value.
-    fn meta<M: Machine<'mir, 'tcx, Provenance = Prov>>(
+    fn meta<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>(
         &self,
         ecx: &InterpCx<'mir, 'tcx, M>,
     ) -> InterpResult<'tcx, MemPlaceMeta<M::Provenance>>;
 
-    fn len<M: Machine<'mir, 'tcx, Provenance = Prov>>(
+    fn len<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>(
         &self,
         ecx: &InterpCx<'mir, 'tcx, M>,
     ) -> InterpResult<'tcx, u64> {
@@ -67,7 +66,7 @@ pub trait Projectable<'mir, 'tcx: 'mir, Prov: Provenance>: Sized {
 
     /// Convert this to an `OpTy`. This might be an irreversible transformation, but is useful for
     /// reading from this thing.
-    fn to_op<M: Machine<'mir, 'tcx, Provenance = Prov>>(
+    fn to_op<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>(
         &self,
         ecx: &InterpCx<'mir, 'tcx, M>,
     ) -> InterpResult<'tcx, OpTy<'tcx, M::Provenance>>;
@@ -85,7 +84,7 @@ where
     ///
     /// This also works for arrays, but then the `usize` index type is restricting.
     /// For indexing into arrays, use `mplace_index`.
-    pub fn project_field<P: Projectable<'mir, 'tcx, M::Provenance>>(
+    pub fn project_field<P: Projectable<'tcx, M::Provenance>>(
         &self,
         base: &P,
         field: usize,
@@ -128,7 +127,7 @@ where
     }
 
     /// Downcasting to an enum variant.
-    pub fn project_downcast<P: Projectable<'mir, 'tcx, M::Provenance>>(
+    pub fn project_downcast<P: Projectable<'tcx, M::Provenance>>(
         &self,
         base: &P,
         variant: VariantIdx,
@@ -149,7 +148,7 @@ where
     }
 
     /// Compute the offset and field layout for accessing the given index.
-    pub fn project_index<P: Projectable<'mir, 'tcx, M::Provenance>>(
+    pub fn project_index<P: Projectable<'tcx, M::Provenance>>(
         &self,
         base: &P,
         index: u64,
@@ -178,7 +177,7 @@ where
         base.offset(offset, field_layout, self)
     }
 
-    fn project_constant_index<P: Projectable<'mir, 'tcx, M::Provenance>>(
+    fn project_constant_index<P: Projectable<'tcx, M::Provenance>>(
         &self,
         base: &P,
         offset: u64,
@@ -204,7 +203,7 @@ where
 
     /// Iterates over all fields of an array. Much more efficient than doing the
     /// same by repeatedly calling `operand_index`.
-    pub fn project_array_fields<'a, P: Projectable<'mir, 'tcx, M::Provenance>>(
+    pub fn project_array_fields<'a, P: Projectable<'tcx, M::Provenance>>(
         &self,
         base: &'a P,
     ) -> InterpResult<'tcx, impl Iterator<Item = InterpResult<'tcx, P>> + 'a>
@@ -224,7 +223,7 @@ where
     }
 
     /// Subslicing
-    fn project_subslice<P: Projectable<'mir, 'tcx, M::Provenance>>(
+    fn project_subslice<P: Projectable<'tcx, M::Provenance>>(
         &self,
         base: &P,
         from: u64,
@@ -284,9 +283,7 @@ where
     #[instrument(skip(self), level = "trace")]
     pub fn project<P>(&self, base: &P, proj_elem: mir::PlaceElem<'tcx>) -> InterpResult<'tcx, P>
     where
-        P: Projectable<'mir, 'tcx, M::Provenance>
-            + From<MPlaceTy<'tcx, M::Provenance>>
-            + std::fmt::Debug,
+        P: Projectable<'tcx, M::Provenance> + From<MPlaceTy<'tcx, M::Provenance>> + std::fmt::Debug,
     {
         use rustc_middle::mir::ProjectionElem::*;
         Ok(match proj_elem {
diff --git a/compiler/rustc_const_eval/src/interpret/step.rs b/compiler/rustc_const_eval/src/interpret/step.rs
index 9182d23128f..1f2d04f4008 100644
--- a/compiler/rustc_const_eval/src/interpret/step.rs
+++ b/compiler/rustc_const_eval/src/interpret/step.rs
@@ -198,7 +198,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 } else {
                     // Write the src to the first element.
                     let first = self.project_index(&dest, 0)?;
-                    self.copy_op(&src, &first.into(), /*allow_transmute*/ false)?;
+                    self.copy_op(&src, &first, /*allow_transmute*/ false)?;
 
                     // This is performance-sensitive code for big static/const arrays! So we
                     // avoid writing each operand individually and instead just make many copies
diff --git a/compiler/rustc_const_eval/src/interpret/visitor.rs b/compiler/rustc_const_eval/src/interpret/visitor.rs
index 4ec19d9e655..531e2bd3ee0 100644
--- a/compiler/rustc_const_eval/src/interpret/visitor.rs
+++ b/compiler/rustc_const_eval/src/interpret/visitor.rs
@@ -13,9 +13,7 @@ use super::{InterpCx, MPlaceTy, Machine, Projectable};
 
 /// How to traverse a value and what to do when we are at the leaves.
 pub trait ValueVisitor<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>>: Sized {
-    type V: Projectable<'mir, 'tcx, M::Provenance>
-        + From<MPlaceTy<'tcx, M::Provenance>>
-        + std::fmt::Debug;
+    type V: Projectable<'tcx, M::Provenance> + From<MPlaceTy<'tcx, M::Provenance>>;
 
     /// The visitor must have an `InterpCx` in it.
     fn ecx(&self) -> &InterpCx<'mir, 'tcx, M>;
diff --git a/src/tools/miri/src/concurrency/data_race.rs b/src/tools/miri/src/concurrency/data_race.rs
index 84ef27f7365..4db55abd232 100644
--- a/src/tools/miri/src/concurrency/data_race.rs
+++ b/src/tools/miri/src/concurrency/data_race.rs
@@ -490,7 +490,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: MiriInterpCxExt<'mir, 'tcx> {
         this.atomic_access_check(dest)?;
 
         this.validate_overlapping_atomic(dest)?;
-        this.allow_data_races_mut(move |this| this.write_scalar(val, &dest.into()))?;
+        this.allow_data_races_mut(move |this| this.write_scalar(val, dest))?;
         this.validate_atomic_store(dest, atomic)?;
         // FIXME: it's not possible to get the value before write_scalar. A read_scalar will cause
         // side effects from a read the program did not perform. So we have to initialise
@@ -518,7 +518,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: MiriInterpCxExt<'mir, 'tcx> {
         // Atomics wrap around on overflow.
         let val = this.binary_op(op, &old, rhs)?;
         let val = if neg { this.unary_op(mir::UnOp::Not, &val)? } else { val };
-        this.allow_data_races_mut(|this| this.write_immediate(*val, &place.into()))?;
+        this.allow_data_races_mut(|this| this.write_immediate(*val, place))?;
 
         this.validate_atomic_rmw(place, atomic)?;
 
@@ -539,7 +539,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: MiriInterpCxExt<'mir, 'tcx> {
 
         this.validate_overlapping_atomic(place)?;
         let old = this.allow_data_races_mut(|this| this.read_scalar(&place.into()))?;
-        this.allow_data_races_mut(|this| this.write_scalar(new, &place.into()))?;
+        this.allow_data_races_mut(|this| this.write_scalar(new, place))?;
 
         this.validate_atomic_rmw(place, atomic)?;
 
@@ -569,7 +569,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: MiriInterpCxExt<'mir, 'tcx> {
             if lt { &rhs } else { &old }
         };
 
-        this.allow_data_races_mut(|this| this.write_immediate(**new_val, &place.into()))?;
+        this.allow_data_races_mut(|this| this.write_immediate(**new_val, place))?;
 
         this.validate_atomic_rmw(place, atomic)?;
 
@@ -621,7 +621,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: MiriInterpCxExt<'mir, 'tcx> {
         // if successful, perform a full rw-atomic validation
         // otherwise treat this as an atomic load with the fail ordering.
         if cmpxchg_success {
-            this.allow_data_races_mut(|this| this.write_scalar(new, &place.into()))?;
+            this.allow_data_races_mut(|this| this.write_scalar(new, place))?;
             this.validate_atomic_rmw(place, success)?;
             this.buffered_atomic_rmw(new, place, success, old.to_scalar())?;
         } else {
diff --git a/src/tools/miri/src/concurrency/thread.rs b/src/tools/miri/src/concurrency/thread.rs
index 25c8df43ee2..9c11ad85aef 100644
--- a/src/tools/miri/src/concurrency/thread.rs
+++ b/src/tools/miri/src/concurrency/thread.rs
@@ -834,7 +834,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         if let Some(thread_info_place) = thread {
             this.write_scalar(
                 Scalar::from_uint(new_thread_id.to_u32(), thread_info_place.layout.size),
-                &thread_info_place.into(),
+                &thread_info_place,
             )?;
         }
 
diff --git a/src/tools/miri/src/eval.rs b/src/tools/miri/src/eval.rs
index 4f7b70649a9..36c43053648 100644
--- a/src/tools/miri/src/eval.rs
+++ b/src/tools/miri/src/eval.rs
@@ -321,7 +321,7 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
         let argvs_place = ecx.allocate(argvs_layout, MiriMemoryKind::Machine.into())?;
         for (idx, arg) in argvs.into_iter().enumerate() {
             let place = ecx.project_field(&argvs_place, idx)?;
-            ecx.write_immediate(arg, &place.into())?;
+            ecx.write_immediate(arg, &place)?;
         }
         ecx.mark_immutable(&argvs_place);
         // A pointer to that place is the 3rd argument for main.
@@ -330,7 +330,7 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
         {
             let argc_place =
                 ecx.allocate(ecx.machine.layouts.isize, MiriMemoryKind::Machine.into())?;
-            ecx.write_scalar(argc, &argc_place.into())?;
+            ecx.write_scalar(argc, &argc_place)?;
             ecx.mark_immutable(&argc_place);
             ecx.machine.argc = Some(*argc_place);
 
@@ -338,7 +338,7 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
                 ecx.layout_of(Ty::new_imm_ptr(tcx, tcx.types.unit))?,
                 MiriMemoryKind::Machine.into(),
             )?;
-            ecx.write_immediate(argv, &argv_place.into())?;
+            ecx.write_immediate(argv, &argv_place)?;
             ecx.mark_immutable(&argv_place);
             ecx.machine.argv = Some(*argv_place);
         }
@@ -355,7 +355,7 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
             // Store the UTF-16 string. We just allocated so we know the bounds are fine.
             for (idx, &c) in cmd_utf16.iter().enumerate() {
                 let place = ecx.project_field(&cmd_place, idx)?;
-                ecx.write_scalar(Scalar::from_u16(c), &place.into())?;
+                ecx.write_scalar(Scalar::from_u16(c), &place)?;
             }
             ecx.mark_immutable(&cmd_place);
         }
diff --git a/src/tools/miri/src/helpers.rs b/src/tools/miri/src/helpers.rs
index f6a438f5d62..7e9f9c05c0c 100644
--- a/src/tools/miri/src/helpers.rs
+++ b/src/tools/miri/src/helpers.rs
@@ -231,7 +231,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
     }
 
     /// Project to the given *named* field (which must be a struct or union type).
-    fn project_field_named<P: Projectable<'mir, 'tcx, Provenance>>(
+    fn project_field_named<P: Projectable<'tcx, Provenance>>(
         &self,
         base: &P,
         name: &str,
@@ -252,13 +252,13 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
     fn write_int(
         &mut self,
         i: impl Into<i128>,
-        dest: &PlaceTy<'tcx, Provenance>,
+        dest: &impl Writeable<'tcx, Provenance>,
     ) -> InterpResult<'tcx> {
-        assert!(dest.layout.abi.is_scalar(), "write_int on non-scalar type {}", dest.layout.ty);
-        let val = if dest.layout.abi.is_signed() {
-            Scalar::from_int(i, dest.layout.size)
+        assert!(dest.layout().abi.is_scalar(), "write_int on non-scalar type {}", dest.layout().ty);
+        let val = if dest.layout().abi.is_signed() {
+            Scalar::from_int(i, dest.layout().size)
         } else {
-            Scalar::from_uint(u64::try_from(i.into()).unwrap(), dest.layout.size)
+            Scalar::from_uint(u64::try_from(i.into()).unwrap(), dest.layout().size)
         };
         self.eval_context_mut().write_scalar(val, dest)
     }
@@ -267,12 +267,12 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
     fn write_int_fields(
         &mut self,
         values: &[i128],
-        dest: &MPlaceTy<'tcx, Provenance>,
+        dest: &impl Writeable<'tcx, Provenance>,
     ) -> InterpResult<'tcx> {
         let this = self.eval_context_mut();
         for (idx, &val) in values.iter().enumerate() {
             let field = this.project_field(dest, idx)?;
-            this.write_int(val, &field.into())?;
+            this.write_int(val, &field)?;
         }
         Ok(())
     }
@@ -281,18 +281,18 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
     fn write_int_fields_named(
         &mut self,
         values: &[(&str, i128)],
-        dest: &MPlaceTy<'tcx, Provenance>,
+        dest: &impl Writeable<'tcx, Provenance>,
     ) -> InterpResult<'tcx> {
         let this = self.eval_context_mut();
         for &(name, val) in values.iter() {
             let field = this.project_field_named(dest, name)?;
-            this.write_int(val, &field.into())?;
+            this.write_int(val, &field)?;
         }
         Ok(())
     }
 
     /// Write a 0 of the appropriate size to `dest`.
-    fn write_null(&mut self, dest: &PlaceTy<'tcx, Provenance>) -> InterpResult<'tcx> {
+    fn write_null(&mut self, dest: &impl Writeable<'tcx, Provenance>) -> InterpResult<'tcx> {
         self.write_int(0, dest)
     }
 
@@ -606,7 +606,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
             // Allocate new place, set initial value to 0.
             let errno_layout = this.machine.layouts.u32;
             let errno_place = this.allocate(errno_layout, MiriMemoryKind::Machine.into())?;
-            this.write_scalar(Scalar::from_u32(0), &errno_place.into())?;
+            this.write_scalar(Scalar::from_u32(0), &errno_place)?;
             this.active_thread_mut().last_error = Some(errno_place);
             Ok(errno_place)
         }
@@ -616,7 +616,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
     fn set_last_error(&mut self, scalar: Scalar<Provenance>) -> InterpResult<'tcx> {
         let this = self.eval_context_mut();
         let errno_place = this.last_error_place()?;
-        this.write_scalar(scalar, &errno_place.into())
+        this.write_scalar(scalar, &errno_place)
     }
 
     /// Gets the last error variable.
@@ -785,7 +785,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
     ) -> InterpResult<'tcx, ()> {
         let this = self.eval_context_mut();
         let value_place = this.deref_operand_and_offset(op, offset, base_layout, value_layout)?;
-        this.write_scalar(value, &value_place.into())
+        this.write_scalar(value, &value_place)
     }
 
     /// Parse a `timespec` struct and return it as a `std::time::Duration`. It returns `None`
diff --git a/src/tools/miri/src/machine.rs b/src/tools/miri/src/machine.rs
index a8f89d56f6d..8d24d9748bf 100644
--- a/src/tools/miri/src/machine.rs
+++ b/src/tools/miri/src/machine.rs
@@ -651,7 +651,7 @@ impl<'mir, 'tcx> MiriMachine<'mir, 'tcx> {
         val: ImmTy<'tcx, Provenance>,
     ) -> InterpResult<'tcx> {
         let place = this.allocate(val.layout, MiriMemoryKind::ExternStatic.into())?;
-        this.write_immediate(*val, &place.into())?;
+        this.write_immediate(*val, &place)?;
         Self::add_extern_static(this, name, place.ptr);
         Ok(())
     }
diff --git a/src/tools/miri/src/shims/backtrace.rs b/src/tools/miri/src/shims/backtrace.rs
index e4aa7467cbe..e89b2e01a39 100644
--- a/src/tools/miri/src/shims/backtrace.rs
+++ b/src/tools/miri/src/shims/backtrace.rs
@@ -85,7 +85,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 for (i, ptr) in ptrs.into_iter().enumerate() {
                     let place = this.project_index(&alloc, i as u64)?;
 
-                    this.write_pointer(ptr, &place.into())?;
+                    this.write_pointer(ptr, &place)?;
                 }
 
                 this.write_immediate(
@@ -106,7 +106,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
                     let op_place = buf_place.offset(offset, ptr_layout, this)?;
 
-                    this.write_pointer(ptr, &op_place.into())?;
+                    this.write_pointer(ptr, &op_place)?;
                 }
             }
             _ => throw_unsup_format!("unknown `miri_get_backtrace` flags {}", flags),
@@ -196,33 +196,33 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
                 this.write_immediate(
                     name_alloc.to_ref(this),
-                    &this.project_field(&dest, 0)?.into(),
+                    &this.project_field(&dest, 0)?,
                 )?;
                 this.write_immediate(
                     filename_alloc.to_ref(this),
-                    &this.project_field(&dest, 1)?.into(),
+                    &this.project_field(&dest, 1)?,
                 )?;
             }
             1 => {
                 this.write_scalar(
                     Scalar::from_target_usize(name.len().try_into().unwrap(), this),
-                    &this.project_field(&dest, 0)?.into(),
+                    &this.project_field(&dest, 0)?,
                 )?;
                 this.write_scalar(
                     Scalar::from_target_usize(filename.len().try_into().unwrap(), this),
-                    &this.project_field(&dest, 1)?.into(),
+                    &this.project_field(&dest, 1)?,
                 )?;
             }
             _ => throw_unsup_format!("unknown `miri_resolve_frame` flags {}", flags),
         }
 
-        this.write_scalar(Scalar::from_u32(lineno), &this.project_field(&dest, 2)?.into())?;
-        this.write_scalar(Scalar::from_u32(colno), &this.project_field(&dest, 3)?.into())?;
+        this.write_scalar(Scalar::from_u32(lineno), &this.project_field(&dest, 2)?)?;
+        this.write_scalar(Scalar::from_u32(colno), &this.project_field(&dest, 3)?)?;
 
         // Support a 4-field struct for now - this is deprecated
         // and slated for removal.
         if num_fields == 5 {
-            this.write_pointer(fn_ptr, &this.project_field(&dest, 4)?.into())?;
+            this.write_pointer(fn_ptr, &this.project_field(&dest, 4)?)?;
         }
 
         Ok(())
diff --git a/src/tools/miri/src/shims/env.rs b/src/tools/miri/src/shims/env.rs
index f98fd0431ae..8c72c4d3a42 100644
--- a/src/tools/miri/src/shims/env.rs
+++ b/src/tools/miri/src/shims/env.rs
@@ -457,9 +457,9 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         let vars_place = this.allocate(vars_layout, MiriMemoryKind::Runtime.into())?;
         for (idx, var) in vars.into_iter().enumerate() {
             let place = this.project_field(&vars_place, idx)?;
-            this.write_pointer(var, &place.into())?;
+            this.write_pointer(var, &place)?;
         }
-        this.write_pointer(vars_place.ptr, &this.machine.env_vars.environ.unwrap().into())?;
+        this.write_pointer(vars_place.ptr, &this.machine.env_vars.environ.unwrap())?;
 
         Ok(())
     }
diff --git a/src/tools/miri/src/shims/intrinsics/mod.rs b/src/tools/miri/src/shims/intrinsics/mod.rs
index ca2c1652dc1..cb8e7c14710 100644
--- a/src/tools/miri/src/shims/intrinsics/mod.rs
+++ b/src/tools/miri/src/shims/intrinsics/mod.rs
@@ -102,7 +102,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
             "volatile_store" => {
                 let [place, dest] = check_arg_count(args)?;
                 let place = this.deref_operand(place)?;
-                this.copy_op(dest, &place.into(), /*allow_transmute*/ false)?;
+                this.copy_op(dest, &place, /*allow_transmute*/ false)?;
             }
 
             "write_bytes" | "volatile_set_memory" => {
diff --git a/src/tools/miri/src/shims/intrinsics/simd.rs b/src/tools/miri/src/shims/intrinsics/simd.rs
index 3afe5214f08..ed997bad1ef 100644
--- a/src/tools/miri/src/shims/intrinsics/simd.rs
+++ b/src/tools/miri/src/shims/intrinsics/simd.rs
@@ -104,7 +104,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
                         }
                     };
-                    this.write_scalar(val, &dest.into())?;
+                    this.write_scalar(val, &dest)?;
                 }
             }
             #[rustfmt::skip]
@@ -217,7 +217,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                             fmin_op(&left, &right)?
                         }
                     };
-                    this.write_scalar(val, &dest.into())?;
+                    this.write_scalar(val, &dest)?;
                 }
             }
             "fma" => {
@@ -258,7 +258,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                             Scalar::from_u64(res.to_bits())
                         }
                     };
-                    this.write_scalar(val, &dest.into())?;
+                    this.write_scalar(val, &dest)?;
                 }
             }
             #[rustfmt::skip]
@@ -378,7 +378,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                     let dest = this.project_index(&dest, i)?;
 
                     let val = if simd_element_to_bool(mask)? { yes } else { no };
-                    this.write_immediate(*val, &dest.into())?;
+                    this.write_immediate(*val, &dest)?;
                 }
             }
             "select_bitmask" => {
@@ -408,7 +408,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                     let dest = this.project_index(&dest, i.into())?;
 
                     let val = if mask != 0 { yes } else { no };
-                    this.write_immediate(*val, &dest.into())?;
+                    this.write_immediate(*val, &dest)?;
                 }
                 for i in dest_len..bitmask_len {
                     // If the mask is "padded", ensure that padding is all-zero.
@@ -472,7 +472,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                                 to_ty = dest.layout.ty,
                             ),
                     };
-                    this.write_immediate(val, &dest.into())?;
+                    this.write_immediate(val, &dest)?;
                 }
             }
             "shuffle" => {
@@ -513,7 +513,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                             "simd_shuffle index {src_index} is out of bounds for 2 vectors of size {left_len}",
                         );
                     };
-                    this.write_immediate(*val, &dest.into())?;
+                    this.write_immediate(*val, &dest)?;
                 }
             }
             "gather" => {
@@ -539,7 +539,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                     } else {
                         passthru
                     };
-                    this.write_immediate(*val, &dest.into())?;
+                    this.write_immediate(*val, &dest)?;
                 }
             }
             "scatter" => {
@@ -558,7 +558,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
                     if simd_element_to_bool(mask)? {
                         let place = this.deref_operand(&ptr.into())?;
-                        this.write_immediate(*value, &place.into())?;
+                        this.write_immediate(*value, &place)?;
                     }
                 }
             }
@@ -588,7 +588,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 // We have to force the place type to be an int so that we can write `res` into it.
                 let mut dest = this.force_allocation(dest)?;
                 dest.layout = this.machine.layouts.uint(dest.layout.size).unwrap();
-                this.write_int(res, &dest.into())?;
+                this.write_int(res, &dest)?;
             }
 
             name => throw_unsup_format!("unimplemented intrinsic: `simd_{name}`"),
diff --git a/src/tools/miri/src/shims/time.rs b/src/tools/miri/src/shims/time.rs
index c761c45a5a1..6667c4d751f 100644
--- a/src/tools/miri/src/shims/time.rs
+++ b/src/tools/miri/src/shims/time.rs
@@ -158,7 +158,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         })?;
         this.write_scalar(
             Scalar::from_i64(qpc),
-            &this.deref_operand(lpPerformanceCount_op)?.into(),
+            &this.deref_operand(lpPerformanceCount_op)?,
         )?;
         Ok(Scalar::from_i32(-1)) // return non-zero on success
     }
@@ -179,7 +179,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         // and thus 10^9 counts per second.
         this.write_scalar(
             Scalar::from_i64(1_000_000_000),
-            &this.deref_operand_as(lpFrequency_op, this.machine.layouts.u64)?.into(),
+            &this.deref_operand_as(lpFrequency_op, this.machine.layouts.u64)?,
         )?;
         Ok(Scalar::from_i32(-1)) // Return non-zero on success
     }
diff --git a/src/tools/miri/src/shims/unix/foreign_items.rs b/src/tools/miri/src/shims/unix/foreign_items.rs
index 14297845d3d..5f3c15c5874 100644
--- a/src/tools/miri/src/shims/unix/foreign_items.rs
+++ b/src/tools/miri/src/shims/unix/foreign_items.rs
@@ -201,14 +201,14 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                     this.write_int(einval, dest)?;
                 } else {
                     if size == 0 {
-                        this.write_null(&ret.into())?;
+                        this.write_null(&ret)?;
                     } else {
                         let ptr = this.allocate_ptr(
                             Size::from_bytes(size),
                             Align::from_bytes(align).unwrap(),
                             MiriMemoryKind::C.into(),
                         )?;
-                        this.write_pointer(ptr, &ret.into())?;
+                        this.write_pointer(ptr, &ret)?;
                     }
                     this.write_null(dest)?;
                 }
@@ -293,7 +293,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
                 // Create key and write it into the memory where `key_ptr` wants it.
                 let key = this.machine.tls.create_tls_key(dtor, key_layout.size)?;
-                this.write_scalar(Scalar::from_uint(key, key_layout.size), &key_place.into())?;
+                this.write_scalar(Scalar::from_uint(key, key_layout.size), &key_place)?;
 
                 // Return success (`0`).
                 this.write_null(dest)?;
@@ -508,7 +508,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 let [_attr, guard_size] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
                 let guard_size = this.deref_operand(guard_size)?;
                 let guard_size_layout = this.libc_ty_layout("size_t");
-                this.write_scalar(Scalar::from_uint(this.machine.page_size, guard_size_layout.size), &guard_size.into())?;
+                this.write_scalar(Scalar::from_uint(this.machine.page_size, guard_size_layout.size), &guard_size)?;
 
                 // Return success (`0`).
                 this.write_null(dest)?;
@@ -538,11 +538,11 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
                 this.write_scalar(
                     Scalar::from_uint(this.machine.stack_addr, this.pointer_size()),
-                    &addr_place.into(),
+                    &addr_place,
                 )?;
                 this.write_scalar(
                     Scalar::from_uint(this.machine.stack_size, this.pointer_size()),
-                    &size_place.into(),
+                    &size_place,
                 )?;
 
                 // Return success (`0`).
@@ -587,20 +587,20 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
                 // Reset all fields to `uninit` to make sure nobody reads them.
                 // (This is a std-only shim so we are okay with such hacks.)
-                this.write_uninit(&pwd.into())?;
+                this.write_uninit(&pwd)?;
 
                 // We only set the home_dir field.
                 #[allow(deprecated)]
                 let home_dir = std::env::home_dir().unwrap();
                 let (written, _) = this.write_path_to_c_str(&home_dir, buf, buflen)?;
                 let pw_dir = this.project_field_named(&pwd, "pw_dir")?;
-                this.write_pointer(buf, &pw_dir.into())?;
+                this.write_pointer(buf, &pw_dir)?;
 
                 if written {
-                    this.write_pointer(pwd.ptr, &result.into())?;
+                    this.write_pointer(pwd.ptr, &result)?;
                     this.write_null(dest)?;
                 } else {
-                    this.write_null(&result.into())?;
+                    this.write_null(&result)?;
                     this.write_scalar(this.eval_libc("ERANGE"), dest)?;
                 }
             }
diff --git a/src/tools/miri/src/shims/unix/fs.rs b/src/tools/miri/src/shims/unix/fs.rs
index 3da6c17f3b0..fe5b01e7610 100644
--- a/src/tools/miri/src/shims/unix/fs.rs
+++ b/src/tools/miri/src/shims/unix/fs.rs
@@ -1457,13 +1457,13 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 )?;
 
                 let result_place = this.deref_operand(result_op)?;
-                this.write_scalar(this.read_scalar(entry_op)?, &result_place.into())?;
+                this.write_scalar(this.read_scalar(entry_op)?, &result_place)?;
 
                 0
             }
             None => {
                 // end of stream: return 0, assign *result=NULL
-                this.write_null(&this.deref_operand(result_op)?.into())?;
+                this.write_null(&this.deref_operand(result_op)?)?;
                 0
             }
             Some(Err(e)) =>
diff --git a/src/tools/miri/src/shims/unix/linux/fd.rs b/src/tools/miri/src/shims/unix/linux/fd.rs
index 9c43651132b..2855157f49d 100644
--- a/src/tools/miri/src/shims/unix/linux/fd.rs
+++ b/src/tools/miri/src/shims/unix/linux/fd.rs
@@ -248,8 +248,8 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         let sv1 = fh.insert_fd(Box::new(SocketPair));
         let sv1 = ScalarInt::try_from_int(sv1, sv.layout.size).unwrap();
 
-        this.write_scalar(sv0, &sv.into())?;
-        this.write_scalar(sv1, &sv.offset(sv.layout.size, sv.layout, this)?.into())?;
+        this.write_scalar(sv0, &sv)?;
+        this.write_scalar(sv1, &sv.offset(sv.layout.size, sv.layout, this)?)?;
 
         Ok(Scalar::from_i32(0))
     }
diff --git a/src/tools/miri/src/shims/unix/macos/foreign_items.rs b/src/tools/miri/src/shims/unix/macos/foreign_items.rs
index 85b950da4fe..f42f3f90684 100644
--- a/src/tools/miri/src/shims/unix/macos/foreign_items.rs
+++ b/src/tools/miri/src/shims/unix/macos/foreign_items.rs
@@ -141,7 +141,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 } else {
                     this.write_scalar(
                         Scalar::from_u32(size_needed.try_into().unwrap()),
-                        &bufsize.into(),
+                        &bufsize,
                     )?;
                     this.write_int(-1, dest)?;
                 }
diff --git a/src/tools/miri/src/shims/unix/sync.rs b/src/tools/miri/src/shims/unix/sync.rs
index 1fa0ffd8ee7..428581801d9 100644
--- a/src/tools/miri/src/shims/unix/sync.rs
+++ b/src/tools/miri/src/shims/unix/sync.rs
@@ -346,7 +346,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         // This can always be revisited to have some external state to catch double-destroys
         // but not complain about the above code. See https://github.com/rust-lang/miri/pull/1933
         this.write_uninit(
-            &this.deref_operand_as(attr_op, this.libc_ty_layout("pthread_mutexattr_t"))?.into(),
+            &this.deref_operand_as(attr_op, this.libc_ty_layout("pthread_mutexattr_t"))?,
         )?;
 
         Ok(0)
@@ -500,7 +500,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
         // This might lead to false positives, see comment in pthread_mutexattr_destroy
         this.write_uninit(
-            &this.deref_operand_as(mutex_op, this.libc_ty_layout("pthread_mutex_t"))?.into(),
+            &this.deref_operand_as(mutex_op, this.libc_ty_layout("pthread_mutex_t"))?,
         )?;
         // FIXME: delete interpreter state associated with this mutex.
 
@@ -625,7 +625,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
         // This might lead to false positives, see comment in pthread_mutexattr_destroy
         this.write_uninit(
-            &this.deref_operand_as(rwlock_op, this.libc_ty_layout("pthread_rwlock_t"))?.into(),
+            &this.deref_operand_as(rwlock_op, this.libc_ty_layout("pthread_rwlock_t"))?,
         )?;
         // FIXME: delete interpreter state associated with this rwlock.
 
@@ -675,7 +675,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         let this = self.eval_context_mut();
 
         let clock_id = condattr_get_clock_id(this, attr_op)?;
-        this.write_scalar(Scalar::from_i32(clock_id), &this.deref_operand(clk_id_op)?.into())?;
+        this.write_scalar(Scalar::from_i32(clock_id), &this.deref_operand(clk_id_op)?)?;
 
         Ok(Scalar::from_i32(0))
     }
@@ -691,7 +691,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
         // This might lead to false positives, see comment in pthread_mutexattr_destroy
         this.write_uninit(
-            &this.deref_operand_as(attr_op, this.libc_ty_layout("pthread_condattr_t"))?.into(),
+            &this.deref_operand_as(attr_op, this.libc_ty_layout("pthread_condattr_t"))?,
         )?;
 
         Ok(0)
@@ -868,7 +868,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
         // This might lead to false positives, see comment in pthread_mutexattr_destroy
         this.write_uninit(
-            &this.deref_operand_as(cond_op, this.libc_ty_layout("pthread_cond_t"))?.into(),
+            &this.deref_operand_as(cond_op, this.libc_ty_layout("pthread_cond_t"))?,
         )?;
         // FIXME: delete interpreter state associated with this condvar.
 
diff --git a/src/tools/miri/src/shims/windows/foreign_items.rs b/src/tools/miri/src/shims/windows/foreign_items.rs
index d64aa53ed95..2f95cfb8bab 100644
--- a/src/tools/miri/src/shims/windows/foreign_items.rs
+++ b/src/tools/miri/src/shims/windows/foreign_items.rs
@@ -125,7 +125,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                         this.project_field_named(&io_status_block, "Information")?;
                     this.write_scalar(
                         Scalar::from_target_usize(n.into(), this),
-                        &io_status_information.into(),
+                        &io_status_information,
                     )?;
                 }
                 // Return whether this was a success. >= 0 is success.