diff --git a/src/base.rs b/src/base.rs
index 4af4b39cc5b9..8839829e2f5c 100644
--- a/src/base.rs
+++ b/src/base.rs
@@ -785,8 +785,10 @@ fn codegen_stmt<'tcx>(
                 }
                 Rvalue::Repeat(ref operand, times) => {
                     let operand = codegen_operand(fx, operand);
-                    let times =
-                        fx.monomorphize(times).eval_target_usize(fx.tcx, ParamEnv::reveal_all());
+                    let times = fx
+                        .monomorphize(times)
+                        .try_to_target_usize(fx.tcx)
+                        .expect("expected monomorphic const in codegen");
                     if operand.layout().size.bytes() == 0 {
                         // Do nothing for ZST's
                     } else if fx.clif_type(operand.layout().ty) == Some(types::I8) {
@@ -944,7 +946,10 @@ fn codegen_stmt<'tcx>(
 fn codegen_array_len<'tcx>(fx: &mut FunctionCx<'_, '_, 'tcx>, place: CPlace<'tcx>) -> Value {
     match *place.layout().ty.kind() {
         ty::Array(_elem_ty, len) => {
-            let len = fx.monomorphize(len).eval_target_usize(fx.tcx, ParamEnv::reveal_all()) as i64;
+            let len = fx
+                .monomorphize(len)
+                .try_to_target_usize(fx.tcx)
+                .expect("expected monomorphic const in codegen") as i64;
             fx.bcx.ins().iconst(fx.pointer_type, len)
         }
         ty::Slice(_elem_ty) => place.to_ptr_unsized().1,
diff --git a/src/common.rs b/src/common.rs
index b9000a3874f5..22ca2070715d 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -309,8 +309,6 @@ pub(crate) struct FunctionCx<'m, 'clif, 'tcx: 'm> {
 }
 
 impl<'tcx> LayoutOfHelpers<'tcx> for FunctionCx<'_, '_, 'tcx> {
-    type LayoutOfResult = TyAndLayout<'tcx>;
-
     #[inline]
     fn handle_layout_err(&self, err: LayoutError<'tcx>, span: Span, ty: Ty<'tcx>) -> ! {
         RevealAllLayoutCx(self.tcx).handle_layout_err(err, span, ty)
@@ -318,8 +316,6 @@ impl<'tcx> LayoutOfHelpers<'tcx> for FunctionCx<'_, '_, 'tcx> {
 }
 
 impl<'tcx> FnAbiOfHelpers<'tcx> for FunctionCx<'_, '_, 'tcx> {
-    type FnAbiOfResult = &'tcx FnAbi<'tcx, Ty<'tcx>>;
-
     #[inline]
     fn handle_fn_abi_err(
         &self,
@@ -450,8 +446,6 @@ impl<'tcx> FunctionCx<'_, '_, 'tcx> {
 pub(crate) struct RevealAllLayoutCx<'tcx>(pub(crate) TyCtxt<'tcx>);
 
 impl<'tcx> LayoutOfHelpers<'tcx> for RevealAllLayoutCx<'tcx> {
-    type LayoutOfResult = TyAndLayout<'tcx>;
-
     #[inline]
     fn handle_layout_err(&self, err: LayoutError<'tcx>, span: Span, ty: Ty<'tcx>) -> ! {
         if let LayoutError::SizeOverflow(_) | LayoutError::ReferencesError(_) = err {
@@ -466,8 +460,6 @@ impl<'tcx> LayoutOfHelpers<'tcx> for RevealAllLayoutCx<'tcx> {
 }
 
 impl<'tcx> FnAbiOfHelpers<'tcx> for RevealAllLayoutCx<'tcx> {
-    type FnAbiOfResult = &'tcx FnAbi<'tcx, Ty<'tcx>>;
-
     #[inline]
     fn handle_fn_abi_err(
         &self,
diff --git a/src/debuginfo/types.rs b/src/debuginfo/types.rs
index 7baf0a3868d2..8a55a23128db 100644
--- a/src/debuginfo/types.rs
+++ b/src/debuginfo/types.rs
@@ -44,7 +44,7 @@ impl DebugContext {
                 type_dbg,
                 ty,
                 *elem_ty,
-                len.eval_target_usize(tcx, ty::ParamEnv::reveal_all()),
+                len.try_to_target_usize(tcx).expect("expected monomorphic const in codegen"),
             ),
             // ty::Slice(_) | ty::Str
             // ty::Dynamic
diff --git a/src/intrinsics/simd.rs b/src/intrinsics/simd.rs
index 0d5410c1351a..ff4b0e847af6 100644
--- a/src/intrinsics/simd.rs
+++ b/src/intrinsics/simd.rs
@@ -131,9 +131,8 @@ pub(super) fn codegen_simd_intrinsic_call<'tcx>(
 
             let idx = generic_args[2]
                 .expect_const()
-                .eval(fx.tcx, ty::ParamEnv::reveal_all(), span)
-                .unwrap()
-                .1
+                .try_to_valtree()
+                .expect("expected monomorphic const in codegen")
                 .unwrap_branch();
 
             assert_eq!(x.layout(), y.layout());
diff --git a/src/unsize.rs b/src/unsize.rs
index e09cd16e89a6..8cfe93b4d9c9 100644
--- a/src/unsize.rs
+++ b/src/unsize.rs
@@ -24,10 +24,10 @@ pub(crate) fn unsized_info<'tcx>(
     let (source, target) =
         fx.tcx.struct_lockstep_tails_for_codegen(source, target, ParamEnv::reveal_all());
     match (&source.kind(), &target.kind()) {
-        (&ty::Array(_, len), &ty::Slice(_)) => fx
-            .bcx
-            .ins()
-            .iconst(fx.pointer_type, len.eval_target_usize(fx.tcx, ParamEnv::reveal_all()) as i64),
+        (&ty::Array(_, len), &ty::Slice(_)) => fx.bcx.ins().iconst(
+            fx.pointer_type,
+            len.try_to_target_usize(fx.tcx).expect("expected monomorphic const in codegen") as i64,
+        ),
         (&ty::Dynamic(data_a, _, src_dyn_kind), &ty::Dynamic(data_b, _, target_dyn_kind))
             if src_dyn_kind == target_dyn_kind =>
         {