9 files changed, 20 insertions, 23 deletions
diff --git a/compiler/rustc_mir_transform/src/const_debuginfo.rs b/compiler/rustc_mir_transform/src/const_debuginfo.rs
index 3577b3d2d80..8944ebed9a7 100644
--- a/compiler/rustc_mir_transform/src/const_debuginfo.rs
+++ b/compiler/rustc_mir_transform/src/const_debuginfo.rs
@@ -19,7 +19,7 @@ impl<'tcx> MirPass<'tcx> for ConstDebugInfo {
         sess.opts.debugging_opts.unsound_mir_opts && sess.mir_opt_level() > 0
     }
 
-    fn run_pass(&self, _: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
+    fn run_pass(&self, _tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         trace!("running ConstDebugInfo on {:?}", body.source);
 
         for (local, constant) in find_optimization_oportunities(body) {
diff --git a/compiler/rustc_mir_transform/src/const_prop.rs b/compiler/rustc_mir_transform/src/const_prop.rs
index 2529a7c4232..412a5b4fc91 100644
--- a/compiler/rustc_mir_transform/src/const_prop.rs
+++ b/compiler/rustc_mir_transform/src/const_prop.rs
@@ -67,6 +67,7 @@ impl<'tcx> MirPass<'tcx> for ConstProp {
         true
     }
 
+    #[instrument(skip(self, tcx), level = "debug")]
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         // will be evaluated by miri and produce its errors there
         if body.source.promoted.is_some() {
@@ -687,7 +688,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
         Operand::Constant(Box::new(Constant {
             span,
             user_ty: None,
-            literal: ty::Const::from_scalar(self.tcx, scalar, ty).into(),
+            literal: ConstantKind::from_scalar(self.tcx, scalar, ty),
         }))
     }
 
@@ -765,20 +766,12 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
                             if let Some(Some(alloc)) = alloc {
                                 // Assign entire constant in a single statement.
                                 // We can't use aggregates, as we run after the aggregate-lowering `MirPhase`.
+                                let const_val = ConstValue::ByRef { alloc, offset: Size::ZERO };
+                                let literal = ConstantKind::Val(const_val, ty);
                                 *rval = Rvalue::Use(Operand::Constant(Box::new(Constant {
                                     span: source_info.span,
                                     user_ty: None,
-                                    literal: self
-                                        .ecx
-                                        .tcx
-                                        .mk_const(ty::ConstS {
-                                            ty,
-                                            kind: ty::ConstKind::Value(ConstValue::ByRef {
-                                                alloc,
-                                                offset: Size::ZERO,
-                                            }),
-                                        })
-                                        .into(),
+                                    literal,
                                 })));
                             }
                         }
diff --git a/compiler/rustc_mir_transform/src/elaborate_drops.rs b/compiler/rustc_mir_transform/src/elaborate_drops.rs
index 8a9f2107316..e0e27c53f18 100644
--- a/compiler/rustc_mir_transform/src/elaborate_drops.rs
+++ b/compiler/rustc_mir_transform/src/elaborate_drops.rs
@@ -470,7 +470,7 @@ impl<'b, 'tcx> ElaborateDropsCtxt<'b, 'tcx> {
         Rvalue::Use(Operand::Constant(Box::new(Constant {
             span,
             user_ty: None,
-            literal: ty::Const::from_bool(self.tcx, val).into(),
+            literal: ConstantKind::from_bool(self.tcx, val),
         })))
     }
 
diff --git a/compiler/rustc_mir_transform/src/generator.rs b/compiler/rustc_mir_transform/src/generator.rs
index 89895fddd0c..f3c67319596 100644
--- a/compiler/rustc_mir_transform/src/generator.rs
+++ b/compiler/rustc_mir_transform/src/generator.rs
@@ -991,7 +991,7 @@ fn insert_panic_block<'tcx>(
         cond: Operand::Constant(Box::new(Constant {
             span: body.span,
             user_ty: None,
-            literal: ty::Const::from_bool(tcx, false).into(),
+            literal: ConstantKind::from_bool(tcx, false),
         })),
         expected: true,
         msg: message,
diff --git a/compiler/rustc_mir_transform/src/instcombine.rs b/compiler/rustc_mir_transform/src/instcombine.rs
index 4fbb7643378..ea10ec5f25c 100644
--- a/compiler/rustc_mir_transform/src/instcombine.rs
+++ b/compiler/rustc_mir_transform/src/instcombine.rs
@@ -3,8 +3,8 @@
 use crate::MirPass;
 use rustc_hir::Mutability;
 use rustc_middle::mir::{
-    BinOp, Body, Constant, LocalDecls, Operand, Place, ProjectionElem, Rvalue, SourceInfo,
-    Statement, StatementKind, Terminator, TerminatorKind, UnOp,
+    BinOp, Body, Constant, ConstantKind, LocalDecls, Operand, Place, ProjectionElem, Rvalue,
+    SourceInfo, Statement, StatementKind, Terminator, TerminatorKind, UnOp,
 };
 use rustc_middle::ty::{self, TyCtxt};
 
@@ -129,8 +129,8 @@ impl<'tcx> InstCombineContext<'tcx, '_> {
                     return;
                 }
 
-                let constant =
-                    Constant { span: source_info.span, literal: len.into(), user_ty: None };
+                let literal = ConstantKind::from_const(len, self.tcx);
+                let constant = Constant { span: source_info.span, literal, user_ty: None };
                 *rvalue = Rvalue::Use(Operand::Constant(Box::new(constant)));
             }
         }
diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs
index 0e52da57e60..b8932251465 100644
--- a/compiler/rustc_mir_transform/src/lib.rs
+++ b/compiler/rustc_mir_transform/src/lib.rs
@@ -531,8 +531,10 @@ fn inner_optimized_mir(tcx: TyCtxt<'_>, did: LocalDefId) -> Body<'_> {
         None => {}
         Some(other) => panic!("do not use `optimized_mir` for constants: {:?}", other),
     }
+    debug!("about to call mir_drops_elaborated...");
     let mut body =
         tcx.mir_drops_elaborated_and_const_checked(ty::WithOptConstParam::unknown(did)).steal();
+    debug!("body: {:#?}", body);
     run_optimization_passes(tcx, &mut body);
 
     debug_assert!(!body.has_free_regions(), "Free regions in optimized MIR");
diff --git a/compiler/rustc_mir_transform/src/lower_intrinsics.rs b/compiler/rustc_mir_transform/src/lower_intrinsics.rs
index 65801069560..989b94b68c1 100644
--- a/compiler/rustc_mir_transform/src/lower_intrinsics.rs
+++ b/compiler/rustc_mir_transform/src/lower_intrinsics.rs
@@ -34,7 +34,7 @@ impl<'tcx> MirPass<'tcx> for LowerIntrinsics {
                                     Rvalue::Use(Operand::Constant(Box::new(Constant {
                                         span: terminator.source_info.span,
                                         user_ty: None,
-                                        literal: ty::Const::zero_sized(tcx, tcx.types.unit).into(),
+                                        literal: ConstantKind::zero_sized(tcx.types.unit),
                                     }))),
                                 ))),
                             });
diff --git a/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs b/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs
index f925d13b2fb..89808d3d4cd 100644
--- a/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs
+++ b/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs
@@ -15,7 +15,7 @@ impl<'tcx> MirPass<'tcx> for RemoveNoopLandingPads {
         sess.panic_strategy() != PanicStrategy::Abort
     }
 
-    fn run_pass(&self, _: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
+    fn run_pass(&self, _tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         debug!("remove_noop_landing_pads({:?})", body);
         self.remove_nop_landing_pads(body)
     }
@@ -81,6 +81,8 @@ impl RemoveNoopLandingPads {
     }
 
     fn remove_nop_landing_pads(&self, body: &mut Body<'_>) {
+        debug!("body: {:#?}", body);
+
         // make sure there's a single resume block
         let resume_block = {
             let patch = MirPatch::new(body);
diff --git a/compiler/rustc_mir_transform/src/shim.rs b/compiler/rustc_mir_transform/src/shim.rs
index 78a4ece2ecb..3be1783ae33 100644
--- a/compiler/rustc_mir_transform/src/shim.rs
+++ b/compiler/rustc_mir_transform/src/shim.rs
@@ -430,7 +430,7 @@ impl<'tcx> CloneShimBuilder<'tcx> {
         let func = Operand::Constant(Box::new(Constant {
             span: self.span,
             user_ty: None,
-            literal: ty::Const::zero_sized(tcx, func_ty).into(),
+            literal: ConstantKind::zero_sized(func_ty),
         }));
 
         let ref_loc = self.make_place(
@@ -630,7 +630,7 @@ fn build_call_shim<'tcx>(
                 Operand::Constant(Box::new(Constant {
                     span,
                     user_ty: None,
-                    literal: ty::Const::zero_sized(tcx, ty).into(),
+                    literal: ConstantKind::zero_sized(ty),
                 })),
                 rcvr.into_iter().collect::<Vec<_>>(),
             )