1 files changed, 19 insertions, 9 deletions

diff --git a/compiler/rustc_const_eval/src/interpret/operand.rs b/compiler/rustc_const_eval/src/interpret/operand.rs
index 221e359d24a..fcc6f8ea852 100644
--- a/compiler/rustc_const_eval/src/interpret/operand.rs
+++ b/compiler/rustc_const_eval/src/interpret/operand.rs
@@ -39,7 +39,7 @@ pub enum Immediate<Prov: Provenance = AllocId> {
 impl<Prov: Provenance> From<Scalar<Prov>> for Immediate<Prov> {
     #[inline(always)]
     fn from(val: Scalar<Prov>) -> Self {
-        Immediate::Scalar(val.into())
+        Immediate::Scalar(val)
     }
 }
 
@@ -53,7 +53,7 @@ impl<Prov: Provenance> Immediate<Prov> {
     }
 
     pub fn new_slice(val: Scalar<Prov>, len: u64, cx: &impl HasDataLayout) -> Self {
-        Immediate::ScalarPair(val.into(), Scalar::from_machine_usize(len, cx).into())
+        Immediate::ScalarPair(val, Scalar::from_machine_usize(len, cx))
     }
 
     pub fn new_dyn_trait(
@@ -61,7 +61,7 @@ impl<Prov: Provenance> Immediate<Prov> {
         vtable: Pointer<Option<Prov>>,
         cx: &impl HasDataLayout,
     ) -> Self {
-        Immediate::ScalarPair(val.into(), Scalar::from_maybe_pointer(vtable, cx))
+        Immediate::ScalarPair(val, Scalar::from_maybe_pointer(vtable, cx))
     }
 
     #[inline]
@@ -341,10 +341,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                     alloc_range(b_offset, b_size),
                     /*read_provenance*/ b.is_ptr(),
                 )?;
-                Some(ImmTy {
-                    imm: Immediate::ScalarPair(a_val.into(), b_val.into()),
-                    layout: mplace.layout,
-                })
+                Some(ImmTy { imm: Immediate::ScalarPair(a_val, b_val), layout: mplace.layout })
             }
             _ => {
                 // Neither a scalar nor scalar pair.
@@ -407,6 +404,9 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         Ok(self.read_immediate(op)?.to_scalar())
     }
 
+    // Pointer-sized reads are fairly common and need target layout access, so we wrap them in
+    // convenience functions.
+
     /// Read a pointer from a place.
     pub fn read_pointer(
         &self,
@@ -414,6 +414,14 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
     ) -> InterpResult<'tcx, Pointer<Option<M::Provenance>>> {
         self.read_scalar(op)?.to_pointer(self)
     }
+    /// Read a pointer-sized unsigned integer from a place.
+    pub fn read_machine_usize(&self, op: &OpTy<'tcx, M::Provenance>) -> InterpResult<'tcx, u64> {
+        self.read_scalar(op)?.to_machine_usize(self)
+    }
+    /// Read a pointer-sized signed integer from a place.
+    pub fn read_machine_isize(&self, op: &OpTy<'tcx, M::Provenance>) -> InterpResult<'tcx, i64> {
+        self.read_scalar(op)?.to_machine_isize(self)
+    }
 
     /// Turn the wide MPlace into a string (must already be dereferenced!)
     pub fn read_str(&self, mplace: &MPlaceTy<'tcx, M::Provenance>) -> InterpResult<'tcx, &str> {
@@ -569,8 +577,10 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             ty::ConstKind::Unevaluated(uv) => {
                 let instance = self.resolve(uv.def, uv.substs)?;
                 let cid = GlobalId { instance, promoted: None };
-                self.ctfe_query(span, |tcx| tcx.eval_to_valtree(self.param_env.and(cid)))?
-                    .unwrap_or_else(|| bug!("unable to create ValTree for {uv:?}"))
+                self.ctfe_query(span, |tcx| {
+                    tcx.eval_to_valtree(self.param_env.with_const().and(cid))
+                })?
+                .unwrap_or_else(|| bug!("unable to create ValTree for {uv:?}"))
             }
             ty::ConstKind::Bound(..) | ty::ConstKind::Infer(..) => {
                 span_bug!(self.cur_span(), "unexpected ConstKind in ctfe: {val:?}")