Auto merge of #116270 - cjgillot:gvn-aggregate, r=oli-obk,RalfJung

See through aggregates in GVN

This PR is extracted from https://github.com/rust-lang/rust/pull/111344

The first 2 commit are cleanups to avoid repeated work. I propose to stop removing useless assignments as part of this pass, and let a later `SimplifyLocals` do it. This makes tests easier to read (among others).

The next 3 commits add a constant folding mechanism to the GVN pass, presented in https://github.com/rust-lang/rust/pull/116012. ~This pass is designed to only use global allocations, to avoid any risk of accidental modification of the stored state.~

The following commits implement opportunistic simplifications, in particular:
- projections of aggregates: `MyStruct { x: a }.x` gets replaced by `a`, works with enums too;
- projections of arrays: `[a, b][0]` becomes `a`;
- projections of repeat expressions: `[a; N][x]` becomes `a`;
- transform arrays of equal operands into a repeat rvalue.

Fixes https://github.com/rust-lang/miri/issues/3090

r? `@oli-obk`

compiler/rustc_const_eval/src/interpret/discriminant.rs

@@ -1,7 +1,8 @@
 //! Functions for reading and writing discriminants of multi-variant layouts (enums and coroutines).
 
-use rustc_middle::ty::layout::{LayoutOf, PrimitiveExt, TyAndLayout};
-use rustc_middle::{mir, ty};
+use rustc_middle::mir;
+use rustc_middle::ty::layout::{LayoutOf, PrimitiveExt};
+use rustc_middle::ty::{self, Ty};
 use rustc_target::abi::{self, TagEncoding};
 use rustc_target::abi::{VariantIdx, Variants};
 
@@ -244,11 +245,11 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
 
     pub fn discriminant_for_variant(
         &self,
-        layout: TyAndLayout<'tcx>,
+        ty: Ty<'tcx>,
         variant: VariantIdx,
     ) -> InterpResult<'tcx, ImmTy<'tcx, M::Provenance>> {
-        let discr_layout = self.layout_of(layout.ty.discriminant_ty(*self.tcx))?;
-        let discr_value = match layout.ty.discriminant_for_variant(*self.tcx, variant) {
+        let discr_layout = self.layout_of(ty.discriminant_ty(*self.tcx))?;
+        let discr_value = match ty.discriminant_for_variant(*self.tcx, variant) {
             Some(discr) => {
                 // This type actually has discriminants.
                 assert_eq!(discr.ty, discr_layout.ty);

compiler/rustc_const_eval/src/interpret/intern.rs

@@ -450,6 +450,42 @@ pub fn intern_const_alloc_recursive<
     Ok(())
 }
 
+/// Intern `ret`. This function assumes that `ret` references no other allocation.
+#[instrument(level = "debug", skip(ecx))]
+pub fn intern_const_alloc_for_constprop<
+    'mir,
+    'tcx: 'mir,
+    T,
+    M: CompileTimeMachine<'mir, 'tcx, T>,
+>(
+    ecx: &mut InterpCx<'mir, 'tcx, M>,
+    alloc_id: AllocId,
+) -> InterpResult<'tcx, ()> {
+    // Move allocation to `tcx`.
+    let Some((_, mut alloc)) = ecx.memory.alloc_map.remove(&alloc_id) else {
+        // Pointer not found in local memory map. It is either a pointer to the global
+        // map, or dangling.
+        if ecx.tcx.try_get_global_alloc(alloc_id).is_none() {
+            throw_ub!(DeadLocal)
+        }
+        // The constant is already in global memory. Do nothing.
+        return Ok(());
+    };
+
+    alloc.mutability = Mutability::Not;
+
+    // We are not doing recursive interning, so we don't currently support provenance.
+    // (If this assertion ever triggers, we should just implement a
+    // proper recursive interning loop.)
+    assert!(alloc.provenance().ptrs().is_empty());
+
+    // Link the alloc id to the actual allocation
+    let alloc = ecx.tcx.mk_const_alloc(alloc);
+    ecx.tcx.set_alloc_id_memory(alloc_id, alloc);
+
+    Ok(())
+}
+
 impl<'mir, 'tcx: 'mir, M: super::intern::CompileTimeMachine<'mir, 'tcx, !>>
     InterpCx<'mir, 'tcx, M>
 {

compiler/rustc_const_eval/src/interpret/intrinsics.rs

@@ -218,7 +218,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             sym::discriminant_value => {
                 let place = self.deref_pointer(&args[0])?;
                 let variant = self.read_discriminant(&place)?;
-                let discr = self.discriminant_for_variant(place.layout, variant)?;
+                let discr = self.discriminant_for_variant(place.layout.ty, variant)?;
                 self.write_immediate(*discr, dest)?;
             }
             sym::exact_div => {

compiler/rustc_const_eval/src/interpret/memory.rs

@@ -1011,7 +1011,7 @@ impl<'tcx, 'a, Prov: Provenance, Extra, Bytes: AllocBytes> AllocRef<'a, 'tcx, Pr
     }
 
     /// Returns whether the allocation has provenance anywhere in the range of the `AllocRef`.
-    pub(crate) fn has_provenance(&self) -> bool {
+    pub fn has_provenance(&self) -> bool {
         !self.alloc.provenance().range_empty(self.range, &self.tcx)
     }
 }

compiler/rustc_const_eval/src/interpret/mod.rs

@@ -21,7 +21,9 @@ mod visitor;
 pub use rustc_middle::mir::interpret::*; // have all the `interpret` symbols in one place: here
 
 pub use self::eval_context::{Frame, FrameInfo, InterpCx, StackPopCleanup};
-pub use self::intern::{intern_const_alloc_recursive, InternKind};
+pub use self::intern::{
+    intern_const_alloc_for_constprop, 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, Readable};

compiler/rustc_const_eval/src/interpret/operand.rs

@@ -169,6 +169,16 @@ impl<'tcx, Prov: Provenance> ImmTy<'tcx, Prov> {
         ImmTy { imm: val.into(), layout }
     }
 
+    #[inline]
+    pub fn from_scalar_pair(a: Scalar<Prov>, b: Scalar<Prov>, layout: TyAndLayout<'tcx>) -> Self {
+        debug_assert!(
+            matches!(layout.abi, Abi::ScalarPair(..)),
+            "`ImmTy::from_scalar_pair` on non-scalar-pair layout"
+        );
+        let imm = Immediate::ScalarPair(a, b);
+        ImmTy { imm, layout }
+    }
+
     #[inline(always)]
     pub fn from_immediate(imm: Immediate<Prov>, layout: TyAndLayout<'tcx>) -> Self {
         debug_assert!(

compiler/rustc_const_eval/src/interpret/step.rs

@@ -297,7 +297,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             Discriminant(place) => {
                 let op = self.eval_place_to_op(place, None)?;
                 let variant = self.read_discriminant(&op)?;
-                let discr = self.discriminant_for_variant(op.layout, variant)?;
+                let discr = self.discriminant_for_variant(op.layout.ty, variant)?;
                 self.write_immediate(*discr, &dest)?;
             }
         }

compiler/rustc_middle/src/mir/consts.rs

@@ -172,6 +172,24 @@ impl<'tcx> ConstValue<'tcx> {
         let end = end.try_into().unwrap();
         Some(data.inner().inspect_with_uninit_and_ptr_outside_interpreter(start..end))
     }
+
+    /// Check if a constant may contain provenance information. This is used by MIR opts.
+    /// Can return `true` even if there is no provenance.
+    pub fn may_have_provenance(&self, tcx: TyCtxt<'tcx>, size: Size) -> bool {
+        match *self {
+            ConstValue::ZeroSized | ConstValue::Scalar(Scalar::Int(_)) => return false,
+            ConstValue::Scalar(Scalar::Ptr(..)) => return true,
+            // It's hard to find out the part of the allocation we point to;
+            // just conservatively check everything.
+            ConstValue::Slice { data, meta: _ } => !data.inner().provenance().ptrs().is_empty(),
+            ConstValue::Indirect { alloc_id, offset } => !tcx
+                .global_alloc(alloc_id)
+                .unwrap_memory()
+                .inner()
+                .provenance()
+                .range_empty(super::AllocRange::from(offset..offset + size), &tcx),
+        }
+    }
 }
 
 ///////////////////////////////////////////////////////////////////////////
@@ -485,6 +503,38 @@ impl<'tcx> Const<'tcx> {
             _ => Self::Ty(c),
         }
     }
+
+    /// Return true if any evaluation of this constant always returns the same value,
+    /// taking into account even pointer identity tests.
+    pub fn is_deterministic(&self) -> bool {
+        // Some constants may generate fresh allocations for pointers they contain,
+        // so using the same constant twice can yield two different results:
+        // - valtrees purposefully generate new allocations
+        // - ConstValue::Slice also generate new allocations
+        match self {
+            Const::Ty(c) => match c.kind() {
+                ty::ConstKind::Param(..) => true,
+                // A valtree may be a reference. Valtree references correspond to a
+                // different allocation each time they are evaluated. Valtrees for primitive
+                // types are fine though.
+                ty::ConstKind::Value(_) => c.ty().is_primitive(),
+                ty::ConstKind::Unevaluated(..) | ty::ConstKind::Expr(..) => false,
+                // Should not appear in runtime MIR.
+                ty::ConstKind::Infer(..)
+                | ty::ConstKind::Bound(..)
+                | ty::ConstKind::Placeholder(..)
+                | ty::ConstKind::Error(..) => bug!(),
+            },
+            Const::Unevaluated(..) => false,
+            // If the same slice appears twice in the MIR, we cannot guarantee that we will
+            // give the same `AllocId` to the data.
+            Const::Val(ConstValue::Slice { .. }, _) => false,
+            Const::Val(
+                ConstValue::ZeroSized | ConstValue::Scalar(_) | ConstValue::Indirect { .. },
+                _,
+            ) => true,
+        }
+    }
 }
 
 /// An unevaluated (potentially generic) constant used in MIR.

compiler/rustc_mir_transform/src/dataflow_const_prop.rs

@@ -406,7 +406,8 @@ impl<'a, 'tcx> ConstAnalysis<'a, 'tcx> {
                 TrackElem::Variant(idx) => self.ecx.project_downcast(op, idx).ok(),
                 TrackElem::Discriminant => {
                     let variant = self.ecx.read_discriminant(op).ok()?;
-                    let discr_value = self.ecx.discriminant_for_variant(op.layout, variant).ok()?;
+                    let discr_value =
+                        self.ecx.discriminant_for_variant(op.layout.ty, variant).ok()?;
                     Some(discr_value.into())
                 }
                 TrackElem::DerefLen => {
@@ -507,7 +508,8 @@ impl<'a, 'tcx> ConstAnalysis<'a, 'tcx> {
             return None;
         }
         let enum_ty_layout = self.tcx.layout_of(self.param_env.and(enum_ty)).ok()?;
-        let discr_value = self.ecx.discriminant_for_variant(enum_ty_layout, variant_index).ok()?;
+        let discr_value =
+            self.ecx.discriminant_for_variant(enum_ty_layout.ty, variant_index).ok()?;
         Some(discr_value.to_scalar())
     }
 
@@ -854,7 +856,7 @@ impl<'tcx> Visitor<'tcx> for OperandCollector<'tcx, '_, '_, '_> {
     }
 }
 
-struct DummyMachine;
+pub(crate) struct DummyMachine;
 
 impl<'mir, 'tcx: 'mir> rustc_const_eval::interpret::Machine<'mir, 'tcx> for DummyMachine {
     rustc_const_eval::interpret::compile_time_machine!(<'mir, 'tcx>);

compiler/rustc_mir_transform/src/gvn.rs

@@ -52,19 +52,59 @@
 //! _a = *_b // _b is &Freeze
 //! _c = *_b // replaced by _c = _a
 //! ```
+//!
+//! # Determinism of constant propagation
+//!
+//! When registering a new `Value`, we attempt to opportunistically evaluate it as a constant.
+//! The evaluated form is inserted in `evaluated` as an `OpTy` or `None` if evaluation failed.
+//!
+//! The difficulty is non-deterministic evaluation of MIR constants. Some `Const` can have
+//! different runtime values each time they are evaluated. This is the case with
+//! `Const::Slice` which have a new pointer each time they are evaluated, and constants that
+//! contain a fn pointer (`AllocId` pointing to a `GlobalAlloc::Function`) pointing to a different
+//! symbol in each codegen unit.
+//!
+//! Meanwhile, we want to be able to read indirect constants. For instance:
+//! ```
+//! static A: &'static &'static u8 = &&63;
+//! fn foo() -> u8 {
+//!     **A // We want to replace by 63.
+//! }
+//! fn bar() -> u8 {
+//!     b"abc"[1] // We want to replace by 'b'.
+//! }
+//! ```
+//!
+//! The `Value::Constant` variant stores a possibly unevaluated constant. Evaluating that constant
+//! may be non-deterministic. When that happens, we assign a disambiguator to ensure that we do not
+//! merge the constants. See `duplicate_slice` test in `gvn.rs`.
+//!
+//! Second, when writing constants in MIR, we do not write `Const::Slice` or `Const`
+//! that contain `AllocId`s.
 
+use rustc_const_eval::interpret::{intern_const_alloc_for_constprop, MemoryKind};
+use rustc_const_eval::interpret::{ImmTy, InterpCx, OpTy, Projectable, Scalar};
 use rustc_data_structures::fx::{FxHashMap, FxIndexSet};
 use rustc_data_structures::graph::dominators::Dominators;
+use rustc_hir::def::DefKind;
 use rustc_index::bit_set::BitSet;
 use rustc_index::IndexVec;
 use rustc_macros::newtype_index;
+use rustc_middle::mir::interpret::GlobalAlloc;
 use rustc_middle::mir::visit::*;
 use rustc_middle::mir::*;
-use rustc_middle::ty::{self, Ty, TyCtxt};
-use rustc_target::abi::{VariantIdx, FIRST_VARIANT};
+use rustc_middle::ty::adjustment::PointerCoercion;
+use rustc_middle::ty::layout::LayoutOf;
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeAndMut};
+use rustc_span::def_id::DefId;
+use rustc_span::DUMMY_SP;
+use rustc_target::abi::{self, Abi, Size, VariantIdx, FIRST_VARIANT};
+use std::borrow::Cow;
 
+use crate::dataflow_const_prop::DummyMachine;
 use crate::ssa::{AssignedValue, SsaLocals};
 use crate::MirPass;
+use either::Either;
 
 pub struct GVN;
 
@@ -118,22 +158,33 @@ fn propagate_ssa<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         let data = &mut body.basic_blocks.as_mut_preserves_cfg()[bb];
         state.visit_basic_block_data(bb, data);
     }
-    let any_replacement = state.any_replacement;
 
     // For each local that is reused (`y` above), we remove its storage statements do avoid any
     // difficulty. Those locals are SSA, so should be easy to optimize by LLVM without storage
     // statements.
     StorageRemover { tcx, reused_locals: state.reused_locals }.visit_body_preserves_cfg(body);
-
-    if any_replacement {
-        crate::simplify::remove_unused_definitions(body);
-    }
 }
 
 newtype_index! {
     struct VnIndex {}
 }
 
+/// Computing the aggregate's type can be quite slow, so we only keep the minimal amount of
+/// information to reconstruct it when needed.
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+enum AggregateTy<'tcx> {
+    /// Invariant: this must not be used for an empty array.
+    Array,
+    Tuple,
+    Def(DefId, ty::GenericArgsRef<'tcx>),
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+enum AddressKind {
+    Ref(BorrowKind),
+    Address(Mutability),
+}
+
 #[derive(Debug, PartialEq, Eq, Hash)]
 enum Value<'tcx> {
     // Root values.
@@ -141,15 +192,21 @@ enum Value<'tcx> {
     /// The `usize` is a counter incremented by `new_opaque`.
     Opaque(usize),
     /// Evaluated or unevaluated constant value.
-    Constant(Const<'tcx>),
+    Constant {
+        value: Const<'tcx>,
+        /// Some constants do not have a deterministic value. To avoid merging two instances of the
+        /// same `Const`, we assign them an additional integer index.
+        disambiguator: usize,
+    },
     /// An aggregate value, either tuple/closure/struct/enum.
     /// This does not contain unions, as we cannot reason with the value.
-    Aggregate(Ty<'tcx>, VariantIdx, Vec<VnIndex>),
+    Aggregate(AggregateTy<'tcx>, VariantIdx, Vec<VnIndex>),
     /// This corresponds to a `[value; count]` expression.
     Repeat(VnIndex, ty::Const<'tcx>),
     /// The address of a place.
     Address {
         place: Place<'tcx>,
+        kind: AddressKind,
         /// Give each borrow and pointer a different provenance, so we don't merge them.
         provenance: usize,
     },
@@ -177,6 +234,7 @@ enum Value<'tcx> {
 
 struct VnState<'body, 'tcx> {
     tcx: TyCtxt<'tcx>,
+    ecx: InterpCx<'tcx, 'tcx, DummyMachine>,
     param_env: ty::ParamEnv<'tcx>,
     local_decls: &'body LocalDecls<'tcx>,
     /// Value stored in each local.
@@ -184,13 +242,14 @@ struct VnState<'body, 'tcx> {
     /// First local to be assigned that value.
     rev_locals: FxHashMap<VnIndex, Vec<Local>>,
     values: FxIndexSet<Value<'tcx>>,
+    /// Values evaluated as constants if possible.
+    evaluated: IndexVec<VnIndex, Option<OpTy<'tcx>>>,
     /// Counter to generate different values.
     /// This is an option to stop creating opaques during replacement.
     next_opaque: Option<usize>,
     ssa: &'body SsaLocals,
     dominators: &'body Dominators<BasicBlock>,
     reused_locals: BitSet<Local>,
-    any_replacement: bool,
 }
 
 impl<'body, 'tcx> VnState<'body, 'tcx> {
@@ -203,23 +262,30 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
     ) -> Self {
         VnState {
             tcx,
+            ecx: InterpCx::new(tcx, DUMMY_SP, param_env, DummyMachine),
             param_env,
             local_decls,
             locals: IndexVec::from_elem(None, local_decls),
             rev_locals: FxHashMap::default(),
             values: FxIndexSet::default(),
+            evaluated: IndexVec::new(),
             next_opaque: Some(0),
             ssa,
             dominators,
             reused_locals: BitSet::new_empty(local_decls.len()),
-            any_replacement: false,
         }
     }
 
     #[instrument(level = "trace", skip(self), ret)]
     fn insert(&mut self, value: Value<'tcx>) -> VnIndex {
-        let (index, _) = self.values.insert_full(value);
-        VnIndex::from_usize(index)
+        let (index, new) = self.values.insert_full(value);
+        let index = VnIndex::from_usize(index);
+        if new {
+            let evaluated = self.eval_to_const(index);
+            let _index = self.evaluated.push(evaluated);
+            debug_assert_eq!(index, _index);
+        }
+        index
     }
 
     /// Create a new `Value` for which we have no information at all, except that it is distinct
@@ -234,9 +300,9 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
 
     /// Create a new `Value::Address` distinct from all the others.
     #[instrument(level = "trace", skip(self), ret)]
-    fn new_pointer(&mut self, place: Place<'tcx>) -> Option<VnIndex> {
+    fn new_pointer(&mut self, place: Place<'tcx>, kind: AddressKind) -> Option<VnIndex> {
         let next_opaque = self.next_opaque.as_mut()?;
-        let value = Value::Address { place, provenance: *next_opaque };
+        let value = Value::Address { place, kind, provenance: *next_opaque };
         *next_opaque += 1;
         Some(self.insert(value))
     }
@@ -258,6 +324,343 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
         }
     }
 
+    fn insert_constant(&mut self, value: Const<'tcx>) -> Option<VnIndex> {
+        let disambiguator = if value.is_deterministic() {
+            // The constant is deterministic, no need to disambiguate.
+            0
+        } else {
+            // Multiple mentions of this constant will yield different values,
+            // so assign a different `disambiguator` to ensure they do not get the same `VnIndex`.
+            let next_opaque = self.next_opaque.as_mut()?;
+            let disambiguator = *next_opaque;
+            *next_opaque += 1;
+            disambiguator
+        };
+        Some(self.insert(Value::Constant { value, disambiguator }))
+    }
+
+    fn insert_scalar(&mut self, scalar: Scalar, ty: Ty<'tcx>) -> VnIndex {
+        self.insert_constant(Const::from_scalar(self.tcx, scalar, ty))
+            .expect("scalars are deterministic")
+    }
+
+    #[instrument(level = "trace", skip(self), ret)]
+    fn eval_to_const(&mut self, value: VnIndex) -> Option<OpTy<'tcx>> {
+        use Value::*;
+        let op = match *self.get(value) {
+            Opaque(_) => return None,
+            // Do not bother evaluating repeat expressions. This would uselessly consume memory.
+            Repeat(..) => return None,
+
+            Constant { ref value, disambiguator: _ } => {
+                self.ecx.eval_mir_constant(value, None, None).ok()?
+            }
+            Aggregate(kind, variant, ref fields) => {
+                let fields = fields
+                    .iter()
+                    .map(|&f| self.evaluated[f].as_ref())
+                    .collect::<Option<Vec<_>>>()?;
+                let ty = match kind {
+                    AggregateTy::Array => {
+                        assert!(fields.len() > 0);
+                        Ty::new_array(self.tcx, fields[0].layout.ty, fields.len() as u64)
+                    }
+                    AggregateTy::Tuple => {
+                        Ty::new_tup_from_iter(self.tcx, fields.iter().map(|f| f.layout.ty))
+                    }
+                    AggregateTy::Def(def_id, args) => {
+                        self.tcx.type_of(def_id).instantiate(self.tcx, args)
+                    }
+                };
+                let variant = if ty.is_enum() { Some(variant) } else { None };
+                let ty = self.ecx.layout_of(ty).ok()?;
+                if ty.is_zst() {
+                    ImmTy::uninit(ty).into()
+                } else if matches!(ty.abi, Abi::Scalar(..) | Abi::ScalarPair(..)) {
+                    let dest = self.ecx.allocate(ty, MemoryKind::Stack).ok()?;
+                    let variant_dest = if let Some(variant) = variant {
+                        self.ecx.project_downcast(&dest, variant).ok()?
+                    } else {
+                        dest.clone()
+                    };
+                    for (field_index, op) in fields.into_iter().enumerate() {
+                        let field_dest = self.ecx.project_field(&variant_dest, field_index).ok()?;
+                        self.ecx.copy_op(op, &field_dest, /*allow_transmute*/ false).ok()?;
+                    }
+                    self.ecx.write_discriminant(variant.unwrap_or(FIRST_VARIANT), &dest).ok()?;
+                    self.ecx.alloc_mark_immutable(dest.ptr().provenance.unwrap()).ok()?;
+                    dest.into()
+                } else {
+                    return None;
+                }
+            }
+
+            Projection(base, elem) => {
+                let value = self.evaluated[base].as_ref()?;
+                let elem = match elem {
+                    ProjectionElem::Deref => ProjectionElem::Deref,
+                    ProjectionElem::Downcast(name, read_variant) => {
+                        ProjectionElem::Downcast(name, read_variant)
+                    }
+                    ProjectionElem::Field(f, ty) => ProjectionElem::Field(f, ty),
+                    ProjectionElem::ConstantIndex { offset, min_length, from_end } => {
+                        ProjectionElem::ConstantIndex { offset, min_length, from_end }
+                    }
+                    ProjectionElem::Subslice { from, to, from_end } => {
+                        ProjectionElem::Subslice { from, to, from_end }
+                    }
+                    ProjectionElem::OpaqueCast(ty) => ProjectionElem::OpaqueCast(ty),
+                    ProjectionElem::Subtype(ty) => ProjectionElem::Subtype(ty),
+                    // This should have been replaced by a `ConstantIndex` earlier.
+                    ProjectionElem::Index(_) => return None,
+                };
+                self.ecx.project(value, elem).ok()?
+            }
+            Address { place, kind, provenance: _ } => {
+                if !place.is_indirect_first_projection() {
+                    return None;
+                }
+                let local = self.locals[place.local]?;
+                let pointer = self.evaluated[local].as_ref()?;
+                let mut mplace = self.ecx.deref_pointer(pointer).ok()?;
+                for proj in place.projection.iter().skip(1) {
+                    // We have no call stack to associate a local with a value, so we cannot interpret indexing.
+                    if matches!(proj, ProjectionElem::Index(_)) {
+                        return None;
+                    }
+                    mplace = self.ecx.project(&mplace, proj).ok()?;
+                }
+                let pointer = mplace.to_ref(&self.ecx);
+                let ty = match kind {
+                    AddressKind::Ref(bk) => Ty::new_ref(
+                        self.tcx,
+                        self.tcx.lifetimes.re_erased,
+                        ty::TypeAndMut { ty: mplace.layout.ty, mutbl: bk.to_mutbl_lossy() },
+                    ),
+                    AddressKind::Address(mutbl) => {
+                        Ty::new_ptr(self.tcx, TypeAndMut { ty: mplace.layout.ty, mutbl })
+                    }
+                };
+                let layout = self.ecx.layout_of(ty).ok()?;
+                ImmTy::from_immediate(pointer, layout).into()
+            }
+
+            Discriminant(base) => {
+                let base = self.evaluated[base].as_ref()?;
+                let variant = self.ecx.read_discriminant(base).ok()?;
+                let discr_value =
+                    self.ecx.discriminant_for_variant(base.layout.ty, variant).ok()?;
+                discr_value.into()
+            }
+            Len(slice) => {
+                let slice = self.evaluated[slice].as_ref()?;
+                let usize_layout = self.ecx.layout_of(self.tcx.types.usize).unwrap();
+                let len = slice.len(&self.ecx).ok()?;
+                let imm = ImmTy::try_from_uint(len, usize_layout)?;
+                imm.into()
+            }
+            NullaryOp(null_op, ty) => {
+                let layout = self.ecx.layout_of(ty).ok()?;
+                if let NullOp::SizeOf | NullOp::AlignOf = null_op && layout.is_unsized() {
+                    return None;
+                }
+                let val = match null_op {
+                    NullOp::SizeOf => layout.size.bytes(),
+                    NullOp::AlignOf => layout.align.abi.bytes(),
+                    NullOp::OffsetOf(fields) => layout
+                        .offset_of_subfield(&self.ecx, fields.iter().map(|f| f.index()))
+                        .bytes(),
+                };
+                let usize_layout = self.ecx.layout_of(self.tcx.types.usize).unwrap();
+                let imm = ImmTy::try_from_uint(val, usize_layout)?;
+                imm.into()
+            }
+            UnaryOp(un_op, operand) => {
+                let operand = self.evaluated[operand].as_ref()?;
+                let operand = self.ecx.read_immediate(operand).ok()?;
+                let (val, _) = self.ecx.overflowing_unary_op(un_op, &operand).ok()?;
+                val.into()
+            }
+            BinaryOp(bin_op, lhs, rhs) => {
+                let lhs = self.evaluated[lhs].as_ref()?;
+                let lhs = self.ecx.read_immediate(lhs).ok()?;
+                let rhs = self.evaluated[rhs].as_ref()?;
+                let rhs = self.ecx.read_immediate(rhs).ok()?;
+                let (val, _) = self.ecx.overflowing_binary_op(bin_op, &lhs, &rhs).ok()?;
+                val.into()
+            }
+            CheckedBinaryOp(bin_op, lhs, rhs) => {
+                let lhs = self.evaluated[lhs].as_ref()?;
+                let lhs = self.ecx.read_immediate(lhs).ok()?;
+                let rhs = self.evaluated[rhs].as_ref()?;
+                let rhs = self.ecx.read_immediate(rhs).ok()?;
+                let (val, overflowed) = self.ecx.overflowing_binary_op(bin_op, &lhs, &rhs).ok()?;
+                let tuple = Ty::new_tup_from_iter(
+                    self.tcx,
+                    [val.layout.ty, self.tcx.types.bool].into_iter(),
+                );
+                let tuple = self.ecx.layout_of(tuple).ok()?;
+                ImmTy::from_scalar_pair(val.to_scalar(), Scalar::from_bool(overflowed), tuple)
+                    .into()
+            }
+            Cast { kind, value, from: _, to } => match kind {
+                CastKind::IntToInt | CastKind::IntToFloat => {
+                    let value = self.evaluated[value].as_ref()?;
+                    let value = self.ecx.read_immediate(value).ok()?;
+                    let to = self.ecx.layout_of(to).ok()?;
+                    let res = self.ecx.int_to_int_or_float(&value, to).ok()?;
+                    res.into()
+                }
+                CastKind::FloatToFloat | CastKind::FloatToInt => {
+                    let value = self.evaluated[value].as_ref()?;
+                    let value = self.ecx.read_immediate(value).ok()?;
+                    let to = self.ecx.layout_of(to).ok()?;
+                    let res = self.ecx.float_to_float_or_int(&value, to).ok()?;
+                    res.into()
+                }
+                CastKind::Transmute => {
+                    let value = self.evaluated[value].as_ref()?;
+                    let to = self.ecx.layout_of(to).ok()?;
+                    // `offset` for immediates only supports scalar/scalar-pair ABIs,
+                    // so bail out if the target is not one.
+                    if value.as_mplace_or_imm().is_right() {
+                        match (value.layout.abi, to.abi) {
+                            (Abi::Scalar(..), Abi::Scalar(..)) => {}
+                            (Abi::ScalarPair(..), Abi::ScalarPair(..)) => {}
+                            _ => return None,
+                        }
+                    }
+                    value.offset(Size::ZERO, to, &self.ecx).ok()?
+                }
+                _ => return None,
+            },
+        };
+        Some(op)
+    }
+
+    fn project(
+        &mut self,
+        place: PlaceRef<'tcx>,
+        value: VnIndex,
+        proj: PlaceElem<'tcx>,
+    ) -> Option<VnIndex> {
+        let proj = match proj {
+            ProjectionElem::Deref => {
+                let ty = place.ty(self.local_decls, self.tcx).ty;
+                if let Some(Mutability::Not) = ty.ref_mutability()
+                    && let Some(pointee_ty) = ty.builtin_deref(true)
+                    && pointee_ty.ty.is_freeze(self.tcx, self.param_env)
+                {
+                    // An immutable borrow `_x` always points to the same value for the
+                    // lifetime of the borrow, so we can merge all instances of `*_x`.
+                    ProjectionElem::Deref
+                } else {
+                    return None;
+                }
+            }
+            ProjectionElem::Downcast(name, index) => ProjectionElem::Downcast(name, index),
+            ProjectionElem::Field(f, ty) => {
+                if let Value::Aggregate(_, _, fields) = self.get(value) {
+                    return Some(fields[f.as_usize()]);
+                } else if let Value::Projection(outer_value, ProjectionElem::Downcast(_, read_variant)) = self.get(value)
+                    && let Value::Aggregate(_, written_variant, fields) = self.get(*outer_value)
+                    // This pass is not aware of control-flow, so we do not know whether the
+                    // replacement we are doing is actually reachable. We could be in any arm of
+                    // ```
+                    // match Some(x) {
+                    //     Some(y) => /* stuff */,
+                    //     None => /* other */,
+                    // }
+                    // ```
+                    //
+                    // In surface rust, the current statement would be unreachable.
+                    //
+                    // However, from the reference chapter on enums and RFC 2195,
+                    // accessing the wrong variant is not UB if the enum has repr.
+                    // So it's not impossible for a series of MIR opts to generate
+                    // a downcast to an inactive variant.
+                    && written_variant == read_variant
+                {
+                    return Some(fields[f.as_usize()]);
+                }
+                ProjectionElem::Field(f, ty)
+            }
+            ProjectionElem::Index(idx) => {
+                if let Value::Repeat(inner, _) = self.get(value) {
+                    return Some(*inner);
+                }
+                let idx = self.locals[idx]?;
+                ProjectionElem::Index(idx)
+            }
+            ProjectionElem::ConstantIndex { offset, min_length, from_end } => {
+                match self.get(value) {
+                    Value::Repeat(inner, _) => {
+                        return Some(*inner);
+                    }
+                    Value::Aggregate(AggregateTy::Array, _, operands) => {
+                        let offset = if from_end {
+                            operands.len() - offset as usize
+                        } else {
+                            offset as usize
+                        };
+                        return operands.get(offset).copied();
+                    }
+                    _ => {}
+                };
+                ProjectionElem::ConstantIndex { offset, min_length, from_end }
+            }
+            ProjectionElem::Subslice { from, to, from_end } => {
+                ProjectionElem::Subslice { from, to, from_end }
+            }
+            ProjectionElem::OpaqueCast(ty) => ProjectionElem::OpaqueCast(ty),
+            ProjectionElem::Subtype(ty) => ProjectionElem::Subtype(ty),
+        };
+
+        Some(self.insert(Value::Projection(value, proj)))
+    }
+
+    /// Simplify the projection chain if we know better.
+    #[instrument(level = "trace", skip(self))]
+    fn simplify_place_projection(&mut self, place: &mut Place<'tcx>, location: Location) {
+        // If the projection is indirect, we treat the local as a value, so can replace it with
+        // another local.
+        if place.is_indirect()
+            && let Some(base) = self.locals[place.local]
+            && let Some(new_local) = self.try_as_local(base, location)
+        {
+            place.local = new_local;
+            self.reused_locals.insert(new_local);
+        }
+
+        let mut projection = Cow::Borrowed(&place.projection[..]);
+
+        for i in 0..projection.len() {
+            let elem = projection[i];
+            if let ProjectionElem::Index(idx) = elem
+                && let Some(idx) = self.locals[idx]
+            {
+                if let Some(offset) = self.evaluated[idx].as_ref()
+                    && let Ok(offset) = self.ecx.read_target_usize(offset)
+                {
+                    projection.to_mut()[i] = ProjectionElem::ConstantIndex {
+                        offset,
+                        min_length: offset + 1,
+                        from_end: false,
+                    };
+                } else if let Some(new_idx) = self.try_as_local(idx, location) {
+                    projection.to_mut()[i] = ProjectionElem::Index(new_idx);
+                    self.reused_locals.insert(new_idx);
+                }
+            }
+        }
+
+        if projection.is_owned() {
+            place.projection = self.tcx.mk_place_elems(&projection);
+        }
+
+        trace!(?place);
+    }
+
     /// Represent the *value* which would be read from `place`, and point `place` to a preexisting
     /// place with the same value (if that already exists).
     #[instrument(level = "trace", skip(self), ret)]
@@ -266,6 +669,8 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
         place: &mut Place<'tcx>,
         location: Location,
     ) -> Option<VnIndex> {
+        self.simplify_place_projection(place, location);
+
         // Invariant: `place` and `place_ref` point to the same value, even if they point to
         // different memory locations.
         let mut place_ref = place.as_ref();
@@ -280,58 +685,18 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
                 place_ref = PlaceRef { local, projection: &place.projection[index..] };
             }
 
-            let proj = match proj {
-                ProjectionElem::Deref => {
-                    let ty = Place::ty_from(
-                        place.local,
-                        &place.projection[..index],
-                        self.local_decls,
-                        self.tcx,
-                    )
-                    .ty;
-                    if let Some(Mutability::Not) = ty.ref_mutability()
-                        && let Some(pointee_ty) = ty.builtin_deref(true)
-                        && pointee_ty.ty.is_freeze(self.tcx, self.param_env)
-                    {
-                        // An immutable borrow `_x` always points to the same value for the
-                        // lifetime of the borrow, so we can merge all instances of `*_x`.
-                        ProjectionElem::Deref
-                    } else {
-                        return None;
-                    }
-                }
-                ProjectionElem::Field(f, ty) => ProjectionElem::Field(f, ty),
-                ProjectionElem::Index(idx) => {
-                    let idx = self.locals[idx]?;
-                    ProjectionElem::Index(idx)
-                }
-                ProjectionElem::ConstantIndex { offset, min_length, from_end } => {
-                    ProjectionElem::ConstantIndex { offset, min_length, from_end }
-                }
-                ProjectionElem::Subslice { from, to, from_end } => {
-                    ProjectionElem::Subslice { from, to, from_end }
-                }
-                ProjectionElem::Downcast(name, index) => ProjectionElem::Downcast(name, index),
-                ProjectionElem::OpaqueCast(ty) => ProjectionElem::OpaqueCast(ty),
-                ProjectionElem::Subtype(ty) => ProjectionElem::Subtype(ty),
-            };
-            value = self.insert(Value::Projection(value, proj));
+            let base = PlaceRef { local: place.local, projection: &place.projection[..index] };
+            value = self.project(base, value, proj)?;
         }
 
-        if let Some(local) = self.try_as_local(value, location)
-            && local != place.local
-        // in case we had no projection to begin with.
-        {
-            *place = local.into();
-            self.reused_locals.insert(local);
-            self.any_replacement = true;
-        } else if place_ref.local != place.local
-            || place_ref.projection.len() < place.projection.len()
-        {
+        if let Some(new_local) = self.try_as_local(value, location) {
+            place_ref = PlaceRef { local: new_local, projection: &[] };
+        }
+
+        if place_ref.local != place.local || place_ref.projection.len() < place.projection.len() {
             // By the invariant on `place_ref`.
             *place = place_ref.project_deeper(&[], self.tcx);
             self.reused_locals.insert(place_ref.local);
-            self.any_replacement = true;
         }
 
         Some(value)
@@ -344,12 +709,14 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
         location: Location,
     ) -> Option<VnIndex> {
         match *operand {
-            Operand::Constant(ref constant) => Some(self.insert(Value::Constant(constant.const_))),
+            Operand::Constant(ref mut constant) => {
+                let const_ = constant.const_.normalize(self.tcx, self.param_env);
+                self.insert_constant(const_)
+            }
             Operand::Copy(ref mut place) | Operand::Move(ref mut place) => {
                 let value = self.simplify_place_value(place, location)?;
                 if let Some(const_) = self.try_as_constant(value) {
                     *operand = Operand::Constant(Box::new(const_));
-                    self.any_replacement = true;
                 }
                 Some(value)
             }
@@ -378,24 +745,15 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
                 Value::Repeat(op, amount)
             }
             Rvalue::NullaryOp(op, ty) => Value::NullaryOp(op, ty),
-            Rvalue::Aggregate(box ref kind, ref mut fields) => {
-                let variant_index = match *kind {
-                    AggregateKind::Array(..)
-                    | AggregateKind::Tuple
-                    | AggregateKind::Closure(..)
-                    | AggregateKind::Coroutine(..) => FIRST_VARIANT,
-                    AggregateKind::Adt(_, variant_index, _, _, None) => variant_index,
-                    // Do not track unions.
-                    AggregateKind::Adt(_, _, _, _, Some(_)) => return None,
-                };
-                let fields: Option<Vec<_>> = fields
-                    .iter_mut()
-                    .map(|op| self.simplify_operand(op, location).or_else(|| self.new_opaque()))
-                    .collect();
-                let ty = rvalue.ty(self.local_decls, self.tcx);
-                Value::Aggregate(ty, variant_index, fields?)
+            Rvalue::Aggregate(..) => return self.simplify_aggregate(rvalue, location),
+            Rvalue::Ref(_, borrow_kind, ref mut place) => {
+                self.simplify_place_projection(place, location);
+                return self.new_pointer(*place, AddressKind::Ref(borrow_kind));
+            }
+            Rvalue::AddressOf(mutbl, ref mut place) => {
+                self.simplify_place_projection(place, location);
+                return self.new_pointer(*place, AddressKind::Address(mutbl));
             }
-            Rvalue::Ref(.., place) | Rvalue::AddressOf(_, place) => return self.new_pointer(place),
 
             // Operations.
             Rvalue::Len(ref mut place) => {
@@ -405,6 +763,14 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
             Rvalue::Cast(kind, ref mut value, to) => {
                 let from = value.ty(self.local_decls, self.tcx);
                 let value = self.simplify_operand(value, location)?;
+                if let CastKind::PointerCoercion(
+                    PointerCoercion::ReifyFnPointer | PointerCoercion::ClosureFnPointer(_),
+                ) = kind
+                {
+                    // Each reification of a generic fn may get a different pointer.
+                    // Do not try to merge them.
+                    return self.new_opaque();
+                }
                 Value::Cast { kind, value, from, to }
             }
             Rvalue::BinaryOp(op, box (ref mut lhs, ref mut rhs)) => {
@@ -423,6 +789,9 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
             }
             Rvalue::Discriminant(ref mut place) => {
                 let place = self.simplify_place_value(place, location)?;
+                if let Some(discr) = self.simplify_discriminant(place) {
+                    return Some(discr);
+                }
                 Value::Discriminant(place)
             }
 
@@ -432,45 +801,182 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
         debug!(?value);
         Some(self.insert(value))
     }
+
+    fn simplify_discriminant(&mut self, place: VnIndex) -> Option<VnIndex> {
+        if let Value::Aggregate(enum_ty, variant, _) = *self.get(place)
+            && let AggregateTy::Def(enum_did, enum_substs) = enum_ty
+            && let DefKind::Enum = self.tcx.def_kind(enum_did)
+        {
+            let enum_ty = self.tcx.type_of(enum_did).instantiate(self.tcx, enum_substs);
+            let discr = self.ecx.discriminant_for_variant(enum_ty, variant).ok()?;
+            return Some(self.insert_scalar(discr.to_scalar(), discr.layout.ty));
+        }
+
+        None
+    }
+
+    fn simplify_aggregate(
+        &mut self,
+        rvalue: &mut Rvalue<'tcx>,
+        location: Location,
+    ) -> Option<VnIndex> {
+        let Rvalue::Aggregate(box ref kind, ref mut fields) = *rvalue else { bug!() };
+
+        let tcx = self.tcx;
+        if fields.is_empty() {
+            let is_zst = match *kind {
+                AggregateKind::Array(..) | AggregateKind::Tuple | AggregateKind::Closure(..) => {
+                    true
+                }
+                // Only enums can be non-ZST.
+                AggregateKind::Adt(did, ..) => tcx.def_kind(did) != DefKind::Enum,
+                // Coroutines are never ZST, as they at least contain the implicit states.
+                AggregateKind::Coroutine(..) => false,
+            };
+
+            if is_zst {
+                let ty = rvalue.ty(self.local_decls, tcx);
+                return self.insert_constant(Const::zero_sized(ty));
+            }
+        }
+
+        let (ty, variant_index) = match *kind {
+            AggregateKind::Array(..) => {
+                assert!(!fields.is_empty());
+                (AggregateTy::Array, FIRST_VARIANT)
+            }
+            AggregateKind::Tuple => {
+                assert!(!fields.is_empty());
+                (AggregateTy::Tuple, FIRST_VARIANT)
+            }
+            AggregateKind::Closure(did, substs) | AggregateKind::Coroutine(did, substs, _) => {
+                (AggregateTy::Def(did, substs), FIRST_VARIANT)
+            }
+            AggregateKind::Adt(did, variant_index, substs, _, None) => {
+                (AggregateTy::Def(did, substs), variant_index)
+            }
+            // Do not track unions.
+            AggregateKind::Adt(_, _, _, _, Some(_)) => return None,
+        };
+
+        let fields: Option<Vec<_>> = fields
+            .iter_mut()
+            .map(|op| self.simplify_operand(op, location).or_else(|| self.new_opaque()))
+            .collect();
+        let fields = fields?;
+
+        if let AggregateTy::Array = ty && fields.len() > 4 {
+            let first = fields[0];
+            if fields.iter().all(|&v| v == first) {
+                let len = ty::Const::from_target_usize(self.tcx, fields.len().try_into().unwrap());
+                if let Some(const_) = self.try_as_constant(first) {
+                    *rvalue = Rvalue::Repeat(Operand::Constant(Box::new(const_)), len);
+                } else if let Some(local) = self.try_as_local(first, location) {
+                    *rvalue = Rvalue::Repeat(Operand::Copy(local.into()), len);
+                    self.reused_locals.insert(local);
+                }
+                return Some(self.insert(Value::Repeat(first, len)));
+            }
+        }
+
+        Some(self.insert(Value::Aggregate(ty, variant_index, fields)))
+    }
+}
+
+fn op_to_prop_const<'tcx>(
+    ecx: &mut InterpCx<'_, 'tcx, DummyMachine>,
+    op: &OpTy<'tcx>,
+) -> Option<ConstValue<'tcx>> {
+    // Do not attempt to propagate unsized locals.
+    if op.layout.is_unsized() {
+        return None;
+    }
+
+    // This constant is a ZST, just return an empty value.
+    if op.layout.is_zst() {
+        return Some(ConstValue::ZeroSized);
+    }
+
+    // Do not synthetize too large constants. Codegen will just memcpy them, which we'd like to avoid.
+    if !matches!(op.layout.abi, Abi::Scalar(..) | Abi::ScalarPair(..)) {
+        return None;
+    }
+
+    // If this constant has scalar ABI, return it as a `ConstValue::Scalar`.
+    if let Abi::Scalar(abi::Scalar::Initialized { .. }) = op.layout.abi
+        && let Ok(scalar) = ecx.read_scalar(op)
+        && scalar.try_to_int().is_ok()
+    {
+        return Some(ConstValue::Scalar(scalar));
+    }
+
+    // If this constant is already represented as an `Allocation`,
+    // try putting it into global memory to return it.
+    if let Either::Left(mplace) = op.as_mplace_or_imm() {
+        let (size, _align) = ecx.size_and_align_of_mplace(&mplace).ok()??;
+
+        // Do not try interning a value that contains provenance.
+        // Due to https://github.com/rust-lang/rust/issues/79738, doing so could lead to bugs.
+        // FIXME: remove this hack once that issue is fixed.
+        let alloc_ref = ecx.get_ptr_alloc(mplace.ptr(), size).ok()??;
+        if alloc_ref.has_provenance() {
+            return None;
+        }
+
+        let pointer = mplace.ptr().into_pointer_or_addr().ok()?;
+        let (alloc_id, offset) = pointer.into_parts();
+        intern_const_alloc_for_constprop(ecx, alloc_id).ok()?;
+        if matches!(ecx.tcx.global_alloc(alloc_id), GlobalAlloc::Memory(_)) {
+            // `alloc_id` may point to a static. Codegen will choke on an `Indirect` with anything
+            // by `GlobalAlloc::Memory`, so do fall through to copying if needed.
+            // FIXME: find a way to treat this more uniformly
+            // (probably by fixing codegen)
+            return Some(ConstValue::Indirect { alloc_id, offset });
+        }
+    }
+
+    // Everything failed: create a new allocation to hold the data.
+    let alloc_id =
+        ecx.intern_with_temp_alloc(op.layout, |ecx, dest| ecx.copy_op(op, dest, false)).ok()?;
+    let value = ConstValue::Indirect { alloc_id, offset: Size::ZERO };
+
+    // Check that we do not leak a pointer.
+    // Those pointers may lose part of their identity in codegen.
+    // FIXME: remove this hack once https://github.com/rust-lang/rust/issues/79738 is fixed.
+    if ecx.tcx.global_alloc(alloc_id).unwrap_memory().inner().provenance().ptrs().is_empty() {
+        return Some(value);
+    }
+
+    None
 }
 
 impl<'tcx> VnState<'_, 'tcx> {
     /// If `index` is a `Value::Constant`, return the `Constant` to be put in the MIR.
     fn try_as_constant(&mut self, index: VnIndex) -> Option<ConstOperand<'tcx>> {
-        if let Value::Constant(const_) = *self.get(index) {
-            // Some constants may contain pointers. We need to preserve the provenance of these
-            // pointers, but not all constants guarantee this:
-            // - valtrees purposefully do not;
-            // - ConstValue::Slice does not either.
-            match const_ {
-                Const::Ty(c) => match c.kind() {
-                    ty::ConstKind::Value(valtree) => match valtree {
-                        // This is just an integer, keep it.
-                        ty::ValTree::Leaf(_) => {}
-                        ty::ValTree::Branch(_) => return None,
-                    },
-                    ty::ConstKind::Param(..)
-                    | ty::ConstKind::Unevaluated(..)
-                    | ty::ConstKind::Expr(..) => {}
-                    // Should not appear in runtime MIR.
-                    ty::ConstKind::Infer(..)
-                    | ty::ConstKind::Bound(..)
-                    | ty::ConstKind::Placeholder(..)
-                    | ty::ConstKind::Error(..) => bug!(),
-                },
-                Const::Unevaluated(..) => {}
-                // If the same slice appears twice in the MIR, we cannot guarantee that we will
-                // give the same `AllocId` to the data.
-                Const::Val(ConstValue::Slice { .. }, _) => return None,
-                Const::Val(
-                    ConstValue::ZeroSized | ConstValue::Scalar(_) | ConstValue::Indirect { .. },
-                    _,
-                ) => {}
-            }
-            Some(ConstOperand { span: rustc_span::DUMMY_SP, user_ty: None, const_ })
-        } else {
-            None
+        // This was already constant in MIR, do not change it.
+        if let Value::Constant { value, disambiguator: _ } = *self.get(index)
+            // If the constant is not deterministic, adding an additional mention of it in MIR will
+            // not give the same value as the former mention.
+            && value.is_deterministic()
+        {
+            return Some(ConstOperand { span: rustc_span::DUMMY_SP, user_ty: None, const_: value });
         }
+
+        let op = self.evaluated[index].as_ref()?;
+        if op.layout.is_unsized() {
+            // Do not attempt to propagate unsized locals.
+            return None;
+        }
+
+        let value = op_to_prop_const(&mut self.ecx, op)?;
+
+        // Check that we do not leak a pointer.
+        // Those pointers may lose part of their identity in codegen.
+        // FIXME: remove this hack once https://github.com/rust-lang/rust/issues/79738 is fixed.
+        assert!(!value.may_have_provenance(self.tcx, op.layout.size));
+
+        let const_ = Const::Val(value, op.layout.ty);
+        Some(ConstOperand { span: rustc_span::DUMMY_SP, user_ty: None, const_ })
     }
 
     /// If there is a local which is assigned `index`, and its assignment strictly dominates `loc`,
@@ -489,27 +995,32 @@ impl<'tcx> MutVisitor<'tcx> for VnState<'_, 'tcx> {
         self.tcx
     }
 
+    fn visit_place(&mut self, place: &mut Place<'tcx>, _: PlaceContext, location: Location) {
+        self.simplify_place_projection(place, location);
+    }
+
     fn visit_operand(&mut self, operand: &mut Operand<'tcx>, location: Location) {
         self.simplify_operand(operand, location);
     }
 
     fn visit_statement(&mut self, stmt: &mut Statement<'tcx>, location: Location) {
-        self.super_statement(stmt, location);
         if let StatementKind::Assign(box (_, ref mut rvalue)) = stmt.kind
             // Do not try to simplify a constant, it's already in canonical shape.
             && !matches!(rvalue, Rvalue::Use(Operand::Constant(_)))
-            && let Some(value) = self.simplify_rvalue(rvalue, location)
         {
-            if let Some(const_) = self.try_as_constant(value) {
-                *rvalue = Rvalue::Use(Operand::Constant(Box::new(const_)));
-                self.any_replacement = true;
-            } else if let Some(local) = self.try_as_local(value, location)
-                && *rvalue != Rvalue::Use(Operand::Move(local.into()))
+            if let Some(value) = self.simplify_rvalue(rvalue, location)
             {
-                *rvalue = Rvalue::Use(Operand::Copy(local.into()));
-                self.reused_locals.insert(local);
-                self.any_replacement = true;
+                if let Some(const_) = self.try_as_constant(value) {
+                    *rvalue = Rvalue::Use(Operand::Constant(Box::new(const_)));
+                } else if let Some(local) = self.try_as_local(value, location)
+                    && *rvalue != Rvalue::Use(Operand::Move(local.into()))
+                {
+                    *rvalue = Rvalue::Use(Operand::Copy(local.into()));
+                    self.reused_locals.insert(local);
+                }
             }
+        } else {
+            self.super_statement(stmt, location);
         }
     }
 }

compiler/rustc_mir_transform/src/lib.rs

@@ -2,6 +2,7 @@
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]
 #![feature(box_patterns)]
+#![feature(cow_is_borrowed)]
 #![feature(decl_macro)]
 #![feature(is_sorted)]
 #![feature(let_chains)]
@@ -590,6 +591,7 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
             &separate_const_switch::SeparateConstSwitch,
             &const_prop::ConstProp,
             &gvn::GVN,
+            &simplify::SimplifyLocals::AfterGVN,
             &dataflow_const_prop::DataflowConstProp,
             &const_debuginfo::ConstDebugInfo,
             &o1(simplify_branches::SimplifyConstCondition::AfterConstProp),

compiler/rustc_mir_transform/src/simplify.rs

@@ -366,6 +366,7 @@ pub fn remove_dead_blocks(body: &mut Body<'_>) {
 
 pub enum SimplifyLocals {
     BeforeConstProp,
+    AfterGVN,
     Final,
 }
 
@@ -373,6 +374,7 @@ impl<'tcx> MirPass<'tcx> for SimplifyLocals {
     fn name(&self) -> &'static str {
         match &self {
             SimplifyLocals::BeforeConstProp => "SimplifyLocals-before-const-prop",
+            SimplifyLocals::AfterGVN => "SimplifyLocals-after-value-numbering",
             SimplifyLocals::Final => "SimplifyLocals-final",
         }
     }

src/tools/miri/tests/pass/function_pointers.rs

@@ -80,9 +80,8 @@ fn main() {
     // but Miri currently uses a fixed address for monomorphic functions.
     assert!(return_fn_ptr(i) == i);
     assert!(return_fn_ptr(i) as unsafe fn() -> i32 == i as fn() -> i32 as unsafe fn() -> i32);
-    // We don't check anything for `f`. Miri gives it many different addresses
-    // but mir-opts can turn them into the same address.
-    let _val = return_fn_ptr(f) != f;
+    // Miri gives different addresses to different reifications of a generic function.
+    assert!(return_fn_ptr(f) != f);
     // However, if we only turn `f` into a function pointer and use that pointer,
     // it is equal to itself.
     let f2 = f as fn() -> i32;

tests/mir-opt/const_debuginfo.main.ConstDebugInfo.diff

@@ -4,12 +4,6 @@
   fn main() -> () {
       let mut _0: ();
       let _1: u8;
-      let mut _5: u8;
-      let mut _6: u8;
-      let mut _7: u8;
-      let mut _8: u8;
-      let mut _12: u32;
-      let mut _13: u32;
       scope 1 {
 -         debug x => _1;
 +         debug x => const 1_u8;
@@ -25,34 +19,34 @@
                   scope 4 {
 -                     debug sum => _4;
 +                     debug sum => const 6_u8;
-                      let _9: &str;
+                      let _5: &str;
                       scope 5 {
--                         debug s => _9;
+-                         debug s => _5;
 +                         debug s => const "hello, world!";
-                          let _14: bool;
-                          let _15: bool;
-                          let _16: u32;
+                          let _8: bool;
+                          let _9: bool;
+                          let _10: u32;
                           scope 6 {
--                             debug ((f: (bool, bool, u32)).0: bool) => _14;
--                             debug ((f: (bool, bool, u32)).1: bool) => _15;
--                             debug ((f: (bool, bool, u32)).2: u32) => _16;
+-                             debug ((f: (bool, bool, u32)).0: bool) => _8;
+-                             debug ((f: (bool, bool, u32)).1: bool) => _9;
+-                             debug ((f: (bool, bool, u32)).2: u32) => _10;
 +                             debug ((f: (bool, bool, u32)).0: bool) => const true;
 +                             debug ((f: (bool, bool, u32)).1: bool) => const false;
 +                             debug ((f: (bool, bool, u32)).2: u32) => const 123_u32;
-                              let _10: std::option::Option<u16>;
+                              let _6: std::option::Option<u16>;
                               scope 7 {
--                                 debug o => _10;
+-                                 debug o => _6;
 +                                 debug o => const Option::<u16>::Some(99_u16);
-                                  let _17: u32;
-                                  let _18: u32;
+                                  let _11: u32;
+                                  let _12: u32;
                                   scope 8 {
--                                     debug ((p: Point).0: u32) => _17;
--                                     debug ((p: Point).1: u32) => _18;
+-                                     debug ((p: Point).0: u32) => _11;
+-                                     debug ((p: Point).1: u32) => _12;
 +                                     debug ((p: Point).0: u32) => const 32_u32;
 +                                     debug ((p: Point).1: u32) => const 32_u32;
-                                      let _11: u32;
+                                      let _7: u32;
                                       scope 9 {
--                                         debug a => _11;
+-                                         debug a => _7;
 +                                         debug a => const 64_u32;
                                       }
                                   }
@@ -69,30 +63,27 @@
           _2 = const 2_u8;
           _3 = const 3_u8;
           StorageLive(_4);
-          StorageLive(_5);
-          _5 = const 3_u8;
           _4 = const 6_u8;
-          StorageDead(_5);
+          StorageLive(_5);
+          _5 = const "hello, world!";
+          StorageLive(_8);
           StorageLive(_9);
-          _9 = const "hello, world!";
-          StorageLive(_14);
-          StorageLive(_15);
-          StorageLive(_16);
-          _14 = const true;
-          _15 = const false;
-          _16 = const 123_u32;
           StorageLive(_10);
-          _10 = const Option::<u16>::Some(99_u16);
-          _17 = const 32_u32;
-          _18 = const 32_u32;
-          StorageLive(_11);
-          _11 = const 64_u32;
-          StorageDead(_11);
-          StorageDead(_10);
-          StorageDead(_14);
-          StorageDead(_15);
-          StorageDead(_16);
+          _8 = const true;
+          _9 = const false;
+          _10 = const 123_u32;
+          StorageLive(_6);
+          _6 = const Option::<u16>::Some(99_u16);
+          _11 = const 32_u32;
+          _12 = const 32_u32;
+          StorageLive(_7);
+          _7 = const 64_u32;
+          StorageDead(_7);
+          StorageDead(_6);
+          StorageDead(_8);
           StorageDead(_9);
+          StorageDead(_10);
+          StorageDead(_5);
           StorageDead(_4);
           return;
       }

tests/mir-opt/gvn.arithmetic.GVN.panic-abort.diff

@@ -67,11 +67,11 @@
       bb0: {
           StorageLive(_2);
           StorageLive(_3);
--         StorageLive(_4);
--         _4 = _1;
+          StorageLive(_4);
+          _4 = _1;
 -         _3 = Add(move _4, const 0_u64);
--         StorageDead(_4);
 +         _3 = Add(_1, const 0_u64);
+          StorageDead(_4);
           _2 = opaque::<u64>(move _3) -> [return: bb1, unwind unreachable];
       }
   
@@ -80,11 +80,11 @@
           StorageDead(_2);
           StorageLive(_5);
           StorageLive(_6);
--         StorageLive(_7);
--         _7 = _1;
+          StorageLive(_7);
+          _7 = _1;
 -         _6 = Sub(move _7, const 0_u64);
--         StorageDead(_7);
 +         _6 = Sub(_1, const 0_u64);
+          StorageDead(_7);
           _5 = opaque::<u64>(move _6) -> [return: bb2, unwind unreachable];
       }
   
@@ -93,11 +93,11 @@
           StorageDead(_5);
           StorageLive(_8);
           StorageLive(_9);
--         StorageLive(_10);
--         _10 = _1;
+          StorageLive(_10);
+          _10 = _1;
 -         _9 = Mul(move _10, const 0_u64);
--         StorageDead(_10);
 +         _9 = Mul(_1, const 0_u64);
+          StorageDead(_10);
           _8 = opaque::<u64>(move _9) -> [return: bb3, unwind unreachable];
       }
   
@@ -106,11 +106,11 @@
           StorageDead(_8);
           StorageLive(_11);
           StorageLive(_12);
--         StorageLive(_13);
--         _13 = _1;
+          StorageLive(_13);
+          _13 = _1;
 -         _12 = Mul(move _13, const 1_u64);
--         StorageDead(_13);
 +         _12 = Mul(_1, const 1_u64);
+          StorageDead(_13);
           _11 = opaque::<u64>(move _12) -> [return: bb4, unwind unreachable];
       }
   
@@ -119,17 +119,18 @@
           StorageDead(_11);
           StorageLive(_14);
           StorageLive(_15);
--         StorageLive(_16);
--         _16 = _1;
-          _17 = Eq(const 0_u64, const 0_u64);
+          StorageLive(_16);
+          _16 = _1;
+-         _17 = Eq(const 0_u64, const 0_u64);
 -         assert(!move _17, "attempt to divide `{}` by zero", _16) -> [success: bb5, unwind unreachable];
-+         assert(!_17, "attempt to divide `{}` by zero", _1) -> [success: bb5, unwind unreachable];
++         _17 = const true;
++         assert(!const true, "attempt to divide `{}` by zero", _1) -> [success: bb5, unwind unreachable];
       }
   
       bb5: {
 -         _15 = Div(move _16, const 0_u64);
--         StorageDead(_16);
 +         _15 = Div(_1, const 0_u64);
+          StorageDead(_16);
           _14 = opaque::<u64>(move _15) -> [return: bb6, unwind unreachable];
       }
   
@@ -138,17 +139,18 @@
           StorageDead(_14);
           StorageLive(_18);
           StorageLive(_19);
--         StorageLive(_20);
--         _20 = _1;
-          _21 = Eq(const 1_u64, const 0_u64);
+          StorageLive(_20);
+          _20 = _1;
+-         _21 = Eq(const 1_u64, const 0_u64);
 -         assert(!move _21, "attempt to divide `{}` by zero", _20) -> [success: bb7, unwind unreachable];
-+         assert(!_21, "attempt to divide `{}` by zero", _1) -> [success: bb7, unwind unreachable];
++         _21 = const false;
++         assert(!const false, "attempt to divide `{}` by zero", _1) -> [success: bb7, unwind unreachable];
       }
   
       bb7: {
 -         _19 = Div(move _20, const 1_u64);
--         StorageDead(_20);
 +         _19 = Div(_1, const 1_u64);
+          StorageDead(_20);
           _18 = opaque::<u64>(move _19) -> [return: bb8, unwind unreachable];
       }
   
@@ -157,8 +159,8 @@
           StorageDead(_18);
           StorageLive(_22);
           StorageLive(_23);
--         StorageLive(_24);
--         _24 = _1;
+          StorageLive(_24);
+          _24 = _1;
 -         _25 = Eq(_24, const 0_u64);
 -         assert(!move _25, "attempt to divide `{}` by zero", const 0_u64) -> [success: bb9, unwind unreachable];
 +         _25 = Eq(_1, const 0_u64);
@@ -167,8 +169,8 @@
   
       bb9: {
 -         _23 = Div(const 0_u64, move _24);
--         StorageDead(_24);
 +         _23 = Div(const 0_u64, _1);
+          StorageDead(_24);
           _22 = opaque::<u64>(move _23) -> [return: bb10, unwind unreachable];
       }
   
@@ -177,17 +179,18 @@
           StorageDead(_22);
           StorageLive(_26);
           StorageLive(_27);
--         StorageLive(_28);
--         _28 = _1;
+          StorageLive(_28);
+          _28 = _1;
 -         _29 = Eq(_28, const 0_u64);
 -         assert(!move _29, "attempt to divide `{}` by zero", const 1_u64) -> [success: bb11, unwind unreachable];
++         _29 = _25;
 +         assert(!_25, "attempt to divide `{}` by zero", const 1_u64) -> [success: bb11, unwind unreachable];
       }
   
       bb11: {
 -         _27 = Div(const 1_u64, move _28);
--         StorageDead(_28);
 +         _27 = Div(const 1_u64, _1);
+          StorageDead(_28);
           _26 = opaque::<u64>(move _27) -> [return: bb12, unwind unreachable];
       }
   
@@ -196,17 +199,18 @@
           StorageDead(_26);
           StorageLive(_30);
           StorageLive(_31);
--         StorageLive(_32);
--         _32 = _1;
+          StorageLive(_32);
+          _32 = _1;
 -         _33 = Eq(const 0_u64, const 0_u64);
 -         assert(!move _33, "attempt to calculate the remainder of `{}` with a divisor of zero", _32) -> [success: bb13, unwind unreachable];
-+         assert(!_17, "attempt to calculate the remainder of `{}` with a divisor of zero", _1) -> [success: bb13, unwind unreachable];
++         _33 = const true;
++         assert(!const true, "attempt to calculate the remainder of `{}` with a divisor of zero", _1) -> [success: bb13, unwind unreachable];
       }
   
       bb13: {
 -         _31 = Rem(move _32, const 0_u64);
--         StorageDead(_32);
 +         _31 = Rem(_1, const 0_u64);
+          StorageDead(_32);
           _30 = opaque::<u64>(move _31) -> [return: bb14, unwind unreachable];
       }
   
@@ -215,17 +219,18 @@
           StorageDead(_30);
           StorageLive(_34);
           StorageLive(_35);
--         StorageLive(_36);
--         _36 = _1;
+          StorageLive(_36);
+          _36 = _1;
 -         _37 = Eq(const 1_u64, const 0_u64);
 -         assert(!move _37, "attempt to calculate the remainder of `{}` with a divisor of zero", _36) -> [success: bb15, unwind unreachable];
-+         assert(!_21, "attempt to calculate the remainder of `{}` with a divisor of zero", _1) -> [success: bb15, unwind unreachable];
++         _37 = const false;
++         assert(!const false, "attempt to calculate the remainder of `{}` with a divisor of zero", _1) -> [success: bb15, unwind unreachable];
       }
   
       bb15: {
 -         _35 = Rem(move _36, const 1_u64);
--         StorageDead(_36);
 +         _35 = Rem(_1, const 1_u64);
+          StorageDead(_36);
           _34 = opaque::<u64>(move _35) -> [return: bb16, unwind unreachable];
       }
   
@@ -234,17 +239,18 @@
           StorageDead(_34);
           StorageLive(_38);
           StorageLive(_39);
--         StorageLive(_40);
--         _40 = _1;
+          StorageLive(_40);
+          _40 = _1;
 -         _41 = Eq(_40, const 0_u64);
 -         assert(!move _41, "attempt to calculate the remainder of `{}` with a divisor of zero", const 0_u64) -> [success: bb17, unwind unreachable];
++         _41 = _25;
 +         assert(!_25, "attempt to calculate the remainder of `{}` with a divisor of zero", const 0_u64) -> [success: bb17, unwind unreachable];
       }
   
       bb17: {
 -         _39 = Rem(const 0_u64, move _40);
--         StorageDead(_40);
 +         _39 = Rem(const 0_u64, _1);
+          StorageDead(_40);
           _38 = opaque::<u64>(move _39) -> [return: bb18, unwind unreachable];
       }
   
@@ -253,17 +259,18 @@
           StorageDead(_38);
           StorageLive(_42);
           StorageLive(_43);
--         StorageLive(_44);
--         _44 = _1;
+          StorageLive(_44);
+          _44 = _1;
 -         _45 = Eq(_44, const 0_u64);
 -         assert(!move _45, "attempt to calculate the remainder of `{}` with a divisor of zero", const 1_u64) -> [success: bb19, unwind unreachable];
++         _45 = _25;
 +         assert(!_25, "attempt to calculate the remainder of `{}` with a divisor of zero", const 1_u64) -> [success: bb19, unwind unreachable];
       }
   
       bb19: {
 -         _43 = Rem(const 1_u64, move _44);
--         StorageDead(_44);
 +         _43 = Rem(const 1_u64, _1);
+          StorageDead(_44);
           _42 = opaque::<u64>(move _43) -> [return: bb20, unwind unreachable];
       }
   
@@ -272,11 +279,11 @@
           StorageDead(_42);
           StorageLive(_46);
           StorageLive(_47);
--         StorageLive(_48);
--         _48 = _1;
+          StorageLive(_48);
+          _48 = _1;
 -         _47 = BitAnd(move _48, const 0_u64);
--         StorageDead(_48);
 +         _47 = BitAnd(_1, const 0_u64);
+          StorageDead(_48);
           _46 = opaque::<u64>(move _47) -> [return: bb21, unwind unreachable];
       }
   
@@ -285,11 +292,11 @@
           StorageDead(_46);
           StorageLive(_49);
           StorageLive(_50);
--         StorageLive(_51);
--         _51 = _1;
+          StorageLive(_51);
+          _51 = _1;
 -         _50 = BitOr(move _51, const 0_u64);
--         StorageDead(_51);
 +         _50 = BitOr(_1, const 0_u64);
+          StorageDead(_51);
           _49 = opaque::<u64>(move _50) -> [return: bb22, unwind unreachable];
       }
   
@@ -298,11 +305,11 @@
           StorageDead(_49);
           StorageLive(_52);
           StorageLive(_53);
--         StorageLive(_54);
--         _54 = _1;
+          StorageLive(_54);
+          _54 = _1;
 -         _53 = BitXor(move _54, const 0_u64);
--         StorageDead(_54);
 +         _53 = BitXor(_1, const 0_u64);
+          StorageDead(_54);
           _52 = opaque::<u64>(move _53) -> [return: bb23, unwind unreachable];
       }
   
@@ -311,11 +318,11 @@
           StorageDead(_52);
           StorageLive(_55);
           StorageLive(_56);
--         StorageLive(_57);
--         _57 = _1;
+          StorageLive(_57);
+          _57 = _1;
 -         _56 = Shr(move _57, const 0_i32);
--         StorageDead(_57);
 +         _56 = Shr(_1, const 0_i32);
+          StorageDead(_57);
           _55 = opaque::<u64>(move _56) -> [return: bb24, unwind unreachable];
       }
   
@@ -324,11 +331,11 @@
           StorageDead(_55);
           StorageLive(_58);
           StorageLive(_59);
--         StorageLive(_60);
--         _60 = _1;
+          StorageLive(_60);
+          _60 = _1;
 -         _59 = Shl(move _60, const 0_i32);
--         StorageDead(_60);
 +         _59 = Shl(_1, const 0_i32);
+          StorageDead(_60);
           _58 = opaque::<u64>(move _59) -> [return: bb25, unwind unreachable];
       }
   

tests/mir-opt/gvn.arithmetic.GVN.panic-unwind.diff

@@ -67,11 +67,11 @@
       bb0: {
           StorageLive(_2);
           StorageLive(_3);
--         StorageLive(_4);
--         _4 = _1;
+          StorageLive(_4);
+          _4 = _1;
 -         _3 = Add(move _4, const 0_u64);
--         StorageDead(_4);
 +         _3 = Add(_1, const 0_u64);
+          StorageDead(_4);
           _2 = opaque::<u64>(move _3) -> [return: bb1, unwind continue];
       }
   
@@ -80,11 +80,11 @@
           StorageDead(_2);
           StorageLive(_5);
           StorageLive(_6);
--         StorageLive(_7);
--         _7 = _1;
+          StorageLive(_7);
+          _7 = _1;
 -         _6 = Sub(move _7, const 0_u64);
--         StorageDead(_7);
 +         _6 = Sub(_1, const 0_u64);
+          StorageDead(_7);
           _5 = opaque::<u64>(move _6) -> [return: bb2, unwind continue];
       }
   
@@ -93,11 +93,11 @@
           StorageDead(_5);
           StorageLive(_8);
           StorageLive(_9);
--         StorageLive(_10);
--         _10 = _1;
+          StorageLive(_10);
+          _10 = _1;
 -         _9 = Mul(move _10, const 0_u64);
--         StorageDead(_10);
 +         _9 = Mul(_1, const 0_u64);
+          StorageDead(_10);
           _8 = opaque::<u64>(move _9) -> [return: bb3, unwind continue];
       }
   
@@ -106,11 +106,11 @@
           StorageDead(_8);
           StorageLive(_11);
           StorageLive(_12);
--         StorageLive(_13);
--         _13 = _1;
+          StorageLive(_13);
+          _13 = _1;
 -         _12 = Mul(move _13, const 1_u64);
--         StorageDead(_13);
 +         _12 = Mul(_1, const 1_u64);
+          StorageDead(_13);
           _11 = opaque::<u64>(move _12) -> [return: bb4, unwind continue];
       }
   
@@ -119,17 +119,18 @@
           StorageDead(_11);
           StorageLive(_14);
           StorageLive(_15);
--         StorageLive(_16);
--         _16 = _1;
-          _17 = Eq(const 0_u64, const 0_u64);
+          StorageLive(_16);
+          _16 = _1;
+-         _17 = Eq(const 0_u64, const 0_u64);
 -         assert(!move _17, "attempt to divide `{}` by zero", _16) -> [success: bb5, unwind continue];
-+         assert(!_17, "attempt to divide `{}` by zero", _1) -> [success: bb5, unwind continue];
++         _17 = const true;
++         assert(!const true, "attempt to divide `{}` by zero", _1) -> [success: bb5, unwind continue];
       }
   
       bb5: {
 -         _15 = Div(move _16, const 0_u64);
--         StorageDead(_16);
 +         _15 = Div(_1, const 0_u64);
+          StorageDead(_16);
           _14 = opaque::<u64>(move _15) -> [return: bb6, unwind continue];
       }
   
@@ -138,17 +139,18 @@
           StorageDead(_14);
           StorageLive(_18);
           StorageLive(_19);
--         StorageLive(_20);
--         _20 = _1;
-          _21 = Eq(const 1_u64, const 0_u64);
+          StorageLive(_20);
+          _20 = _1;
+-         _21 = Eq(const 1_u64, const 0_u64);
 -         assert(!move _21, "attempt to divide `{}` by zero", _20) -> [success: bb7, unwind continue];
-+         assert(!_21, "attempt to divide `{}` by zero", _1) -> [success: bb7, unwind continue];
++         _21 = const false;
++         assert(!const false, "attempt to divide `{}` by zero", _1) -> [success: bb7, unwind continue];
       }
   
       bb7: {
 -         _19 = Div(move _20, const 1_u64);
--         StorageDead(_20);
 +         _19 = Div(_1, const 1_u64);
+          StorageDead(_20);
           _18 = opaque::<u64>(move _19) -> [return: bb8, unwind continue];
       }
   
@@ -157,8 +159,8 @@
           StorageDead(_18);
           StorageLive(_22);
           StorageLive(_23);
--         StorageLive(_24);
--         _24 = _1;
+          StorageLive(_24);
+          _24 = _1;
 -         _25 = Eq(_24, const 0_u64);
 -         assert(!move _25, "attempt to divide `{}` by zero", const 0_u64) -> [success: bb9, unwind continue];
 +         _25 = Eq(_1, const 0_u64);
@@ -167,8 +169,8 @@
   
       bb9: {
 -         _23 = Div(const 0_u64, move _24);
--         StorageDead(_24);
 +         _23 = Div(const 0_u64, _1);
+          StorageDead(_24);
           _22 = opaque::<u64>(move _23) -> [return: bb10, unwind continue];
       }
   
@@ -177,17 +179,18 @@
           StorageDead(_22);
           StorageLive(_26);
           StorageLive(_27);
--         StorageLive(_28);
--         _28 = _1;
+          StorageLive(_28);
+          _28 = _1;
 -         _29 = Eq(_28, const 0_u64);
 -         assert(!move _29, "attempt to divide `{}` by zero", const 1_u64) -> [success: bb11, unwind continue];
++         _29 = _25;
 +         assert(!_25, "attempt to divide `{}` by zero", const 1_u64) -> [success: bb11, unwind continue];
       }
   
       bb11: {
 -         _27 = Div(const 1_u64, move _28);
--         StorageDead(_28);
 +         _27 = Div(const 1_u64, _1);
+          StorageDead(_28);
           _26 = opaque::<u64>(move _27) -> [return: bb12, unwind continue];
       }
   
@@ -196,17 +199,18 @@
           StorageDead(_26);
           StorageLive(_30);
           StorageLive(_31);
--         StorageLive(_32);
--         _32 = _1;
+          StorageLive(_32);
+          _32 = _1;
 -         _33 = Eq(const 0_u64, const 0_u64);
 -         assert(!move _33, "attempt to calculate the remainder of `{}` with a divisor of zero", _32) -> [success: bb13, unwind continue];
-+         assert(!_17, "attempt to calculate the remainder of `{}` with a divisor of zero", _1) -> [success: bb13, unwind continue];
++         _33 = const true;
++         assert(!const true, "attempt to calculate the remainder of `{}` with a divisor of zero", _1) -> [success: bb13, unwind continue];
       }
   
       bb13: {
 -         _31 = Rem(move _32, const 0_u64);
--         StorageDead(_32);
 +         _31 = Rem(_1, const 0_u64);
+          StorageDead(_32);
           _30 = opaque::<u64>(move _31) -> [return: bb14, unwind continue];
       }
   
@@ -215,17 +219,18 @@
           StorageDead(_30);
           StorageLive(_34);
           StorageLive(_35);
--         StorageLive(_36);
--         _36 = _1;
+          StorageLive(_36);
+          _36 = _1;
 -         _37 = Eq(const 1_u64, const 0_u64);
 -         assert(!move _37, "attempt to calculate the remainder of `{}` with a divisor of zero", _36) -> [success: bb15, unwind continue];
-+         assert(!_21, "attempt to calculate the remainder of `{}` with a divisor of zero", _1) -> [success: bb15, unwind continue];
++         _37 = const false;
++         assert(!const false, "attempt to calculate the remainder of `{}` with a divisor of zero", _1) -> [success: bb15, unwind continue];
       }
   
       bb15: {
 -         _35 = Rem(move _36, const 1_u64);
--         StorageDead(_36);
 +         _35 = Rem(_1, const 1_u64);
+          StorageDead(_36);
           _34 = opaque::<u64>(move _35) -> [return: bb16, unwind continue];
       }
   
@@ -234,17 +239,18 @@
           StorageDead(_34);
           StorageLive(_38);
           StorageLive(_39);
--         StorageLive(_40);
--         _40 = _1;
+          StorageLive(_40);
+          _40 = _1;
 -         _41 = Eq(_40, const 0_u64);
 -         assert(!move _41, "attempt to calculate the remainder of `{}` with a divisor of zero", const 0_u64) -> [success: bb17, unwind continue];
++         _41 = _25;
 +         assert(!_25, "attempt to calculate the remainder of `{}` with a divisor of zero", const 0_u64) -> [success: bb17, unwind continue];
       }
   
       bb17: {
 -         _39 = Rem(const 0_u64, move _40);
--         StorageDead(_40);
 +         _39 = Rem(const 0_u64, _1);
+          StorageDead(_40);
           _38 = opaque::<u64>(move _39) -> [return: bb18, unwind continue];
       }
   
@@ -253,17 +259,18 @@
           StorageDead(_38);
           StorageLive(_42);
           StorageLive(_43);
--         StorageLive(_44);
--         _44 = _1;
+          StorageLive(_44);
+          _44 = _1;
 -         _45 = Eq(_44, const 0_u64);
 -         assert(!move _45, "attempt to calculate the remainder of `{}` with a divisor of zero", const 1_u64) -> [success: bb19, unwind continue];
++         _45 = _25;
 +         assert(!_25, "attempt to calculate the remainder of `{}` with a divisor of zero", const 1_u64) -> [success: bb19, unwind continue];
       }
   
       bb19: {
 -         _43 = Rem(const 1_u64, move _44);
--         StorageDead(_44);
 +         _43 = Rem(const 1_u64, _1);
+          StorageDead(_44);
           _42 = opaque::<u64>(move _43) -> [return: bb20, unwind continue];
       }
   
@@ -272,11 +279,11 @@
           StorageDead(_42);
           StorageLive(_46);
           StorageLive(_47);
--         StorageLive(_48);
--         _48 = _1;
+          StorageLive(_48);
+          _48 = _1;
 -         _47 = BitAnd(move _48, const 0_u64);
--         StorageDead(_48);
 +         _47 = BitAnd(_1, const 0_u64);
+          StorageDead(_48);
           _46 = opaque::<u64>(move _47) -> [return: bb21, unwind continue];
       }
   
@@ -285,11 +292,11 @@
           StorageDead(_46);
           StorageLive(_49);
           StorageLive(_50);
--         StorageLive(_51);
--         _51 = _1;
+          StorageLive(_51);
+          _51 = _1;
 -         _50 = BitOr(move _51, const 0_u64);
--         StorageDead(_51);
 +         _50 = BitOr(_1, const 0_u64);
+          StorageDead(_51);
           _49 = opaque::<u64>(move _50) -> [return: bb22, unwind continue];
       }
   
@@ -298,11 +305,11 @@
           StorageDead(_49);
           StorageLive(_52);
           StorageLive(_53);
--         StorageLive(_54);
--         _54 = _1;
+          StorageLive(_54);
+          _54 = _1;
 -         _53 = BitXor(move _54, const 0_u64);
--         StorageDead(_54);
 +         _53 = BitXor(_1, const 0_u64);
+          StorageDead(_54);
           _52 = opaque::<u64>(move _53) -> [return: bb23, unwind continue];
       }
   
@@ -311,11 +318,11 @@
           StorageDead(_52);
           StorageLive(_55);
           StorageLive(_56);
--         StorageLive(_57);
--         _57 = _1;
+          StorageLive(_57);
+          _57 = _1;
 -         _56 = Shr(move _57, const 0_i32);
--         StorageDead(_57);
 +         _56 = Shr(_1, const 0_i32);
+          StorageDead(_57);
           _55 = opaque::<u64>(move _56) -> [return: bb24, unwind continue];
       }
   
@@ -324,11 +331,11 @@
           StorageDead(_55);
           StorageLive(_58);
           StorageLive(_59);
--         StorageLive(_60);
--         _60 = _1;
+          StorageLive(_60);
+          _60 = _1;
 -         _59 = Shl(move _60, const 0_i32);
--         StorageDead(_60);
 +         _59 = Shl(_1, const 0_i32);
+          StorageDead(_60);
           _58 = opaque::<u64>(move _59) -> [return: bb25, unwind continue];
       }
   

tests/mir-opt/gvn.arithmetic_checked.GVN.panic-abort.diff

@@ -20,63 +20,12 @@
       let mut _15: u64;
       let mut _16: u64;
       let mut _17: (u64, bool);
-      let _18: ();
-      let mut _19: u64;
-      let mut _20: u64;
-      let mut _21: bool;
-      let _22: ();
-      let mut _23: u64;
-      let mut _24: u64;
-      let mut _25: bool;
-      let _26: ();
-      let mut _27: u64;
-      let mut _28: u64;
-      let mut _29: bool;
-      let _30: ();
-      let mut _31: u64;
-      let mut _32: u64;
-      let mut _33: bool;
-      let _34: ();
-      let mut _35: u64;
-      let mut _36: u64;
-      let mut _37: bool;
-      let _38: ();
-      let mut _39: u64;
-      let mut _40: u64;
-      let mut _41: bool;
-      let _42: ();
-      let mut _43: u64;
-      let mut _44: u64;
-      let mut _45: bool;
-      let _46: ();
-      let mut _47: u64;
-      let mut _48: u64;
-      let mut _49: bool;
-      let _50: ();
-      let mut _51: u64;
-      let mut _52: u64;
-      let _53: ();
-      let mut _54: u64;
-      let mut _55: u64;
-      let _56: ();
-      let mut _57: u64;
-      let mut _58: u64;
-      let _59: ();
-      let mut _60: u64;
-      let mut _61: u64;
-      let mut _62: u32;
-      let mut _63: bool;
-      let _64: ();
-      let mut _65: u64;
-      let mut _66: u64;
-      let mut _67: u32;
-      let mut _68: bool;
   
       bb0: {
           StorageLive(_2);
           StorageLive(_3);
--         StorageLive(_4);
--         _4 = _1;
+          StorageLive(_4);
+          _4 = _1;
 -         _5 = CheckedAdd(_4, const 0_u64);
 -         assert(!move (_5.1: bool), "attempt to compute `{} + {}`, which would overflow", move _4, const 0_u64) -> [success: bb1, unwind unreachable];
 +         _5 = CheckedAdd(_1, const 0_u64);
@@ -85,7 +34,7 @@
   
       bb1: {
           _3 = move (_5.0: u64);
--         StorageDead(_4);
+          StorageDead(_4);
           _2 = opaque::<u64>(move _3) -> [return: bb2, unwind unreachable];
       }
   
@@ -94,8 +43,8 @@
           StorageDead(_2);
           StorageLive(_6);
           StorageLive(_7);
--         StorageLive(_8);
--         _8 = _1;
+          StorageLive(_8);
+          _8 = _1;
 -         _9 = CheckedSub(_8, const 0_u64);
 -         assert(!move (_9.1: bool), "attempt to compute `{} - {}`, which would overflow", move _8, const 0_u64) -> [success: bb3, unwind unreachable];
 +         _9 = CheckedSub(_1, const 0_u64);
@@ -104,7 +53,7 @@
   
       bb3: {
           _7 = move (_9.0: u64);
--         StorageDead(_8);
+          StorageDead(_8);
           _6 = opaque::<u64>(move _7) -> [return: bb4, unwind unreachable];
       }
   
@@ -113,8 +62,8 @@
           StorageDead(_6);
           StorageLive(_10);
           StorageLive(_11);
--         StorageLive(_12);
--         _12 = _1;
+          StorageLive(_12);
+          _12 = _1;
 -         _13 = CheckedMul(_12, const 0_u64);
 -         assert(!move (_13.1: bool), "attempt to compute `{} * {}`, which would overflow", move _12, const 0_u64) -> [success: bb5, unwind unreachable];
 +         _13 = CheckedMul(_1, const 0_u64);
@@ -123,7 +72,7 @@
   
       bb5: {
           _11 = move (_13.0: u64);
--         StorageDead(_12);
+          StorageDead(_12);
           _10 = opaque::<u64>(move _11) -> [return: bb6, unwind unreachable];
       }
   
@@ -132,8 +81,8 @@
           StorageDead(_10);
           StorageLive(_14);
           StorageLive(_15);
--         StorageLive(_16);
--         _16 = _1;
+          StorageLive(_16);
+          _16 = _1;
 -         _17 = CheckedMul(_16, const 1_u64);
 -         assert(!move (_17.1: bool), "attempt to compute `{} * {}`, which would overflow", move _16, const 1_u64) -> [success: bb7, unwind unreachable];
 +         _17 = CheckedMul(_1, const 1_u64);
@@ -142,246 +91,13 @@
   
       bb7: {
           _15 = move (_17.0: u64);
--         StorageDead(_16);
+          StorageDead(_16);
           _14 = opaque::<u64>(move _15) -> [return: bb8, unwind unreachable];
       }
   
       bb8: {
           StorageDead(_15);
           StorageDead(_14);
-          StorageLive(_18);
-          StorageLive(_19);
--         StorageLive(_20);
--         _20 = _1;
-          _21 = Eq(const 0_u64, const 0_u64);
--         assert(!move _21, "attempt to divide `{}` by zero", _20) -> [success: bb9, unwind unreachable];
-+         assert(!_21, "attempt to divide `{}` by zero", _1) -> [success: bb9, unwind unreachable];
-      }
-  
-      bb9: {
--         _19 = Div(move _20, const 0_u64);
--         StorageDead(_20);
-+         _19 = Div(_1, const 0_u64);
-          _18 = opaque::<u64>(move _19) -> [return: bb10, unwind unreachable];
-      }
-  
-      bb10: {
-          StorageDead(_19);
-          StorageDead(_18);
-          StorageLive(_22);
-          StorageLive(_23);
--         StorageLive(_24);
--         _24 = _1;
-          _25 = Eq(const 1_u64, const 0_u64);
--         assert(!move _25, "attempt to divide `{}` by zero", _24) -> [success: bb11, unwind unreachable];
-+         assert(!_25, "attempt to divide `{}` by zero", _1) -> [success: bb11, unwind unreachable];
-      }
-  
-      bb11: {
--         _23 = Div(move _24, const 1_u64);
--         StorageDead(_24);
-+         _23 = Div(_1, const 1_u64);
-          _22 = opaque::<u64>(move _23) -> [return: bb12, unwind unreachable];
-      }
-  
-      bb12: {
-          StorageDead(_23);
-          StorageDead(_22);
-          StorageLive(_26);
-          StorageLive(_27);
--         StorageLive(_28);
--         _28 = _1;
--         _29 = Eq(_28, const 0_u64);
--         assert(!move _29, "attempt to divide `{}` by zero", const 0_u64) -> [success: bb13, unwind unreachable];
-+         _29 = Eq(_1, const 0_u64);
-+         assert(!_29, "attempt to divide `{}` by zero", const 0_u64) -> [success: bb13, unwind unreachable];
-      }
-  
-      bb13: {
--         _27 = Div(const 0_u64, move _28);
--         StorageDead(_28);
-+         _27 = Div(const 0_u64, _1);
-          _26 = opaque::<u64>(move _27) -> [return: bb14, unwind unreachable];
-      }
-  
-      bb14: {
-          StorageDead(_27);
-          StorageDead(_26);
-          StorageLive(_30);
-          StorageLive(_31);
--         StorageLive(_32);
--         _32 = _1;
--         _33 = Eq(_32, const 0_u64);
--         assert(!move _33, "attempt to divide `{}` by zero", const 1_u64) -> [success: bb15, unwind unreachable];
-+         assert(!_29, "attempt to divide `{}` by zero", const 1_u64) -> [success: bb15, unwind unreachable];
-      }
-  
-      bb15: {
--         _31 = Div(const 1_u64, move _32);
--         StorageDead(_32);
-+         _31 = Div(const 1_u64, _1);
-          _30 = opaque::<u64>(move _31) -> [return: bb16, unwind unreachable];
-      }
-  
-      bb16: {
-          StorageDead(_31);
-          StorageDead(_30);
-          StorageLive(_34);
-          StorageLive(_35);
--         StorageLive(_36);
--         _36 = _1;
--         _37 = Eq(const 0_u64, const 0_u64);
--         assert(!move _37, "attempt to calculate the remainder of `{}` with a divisor of zero", _36) -> [success: bb17, unwind unreachable];
-+         assert(!_21, "attempt to calculate the remainder of `{}` with a divisor of zero", _1) -> [success: bb17, unwind unreachable];
-      }
-  
-      bb17: {
--         _35 = Rem(move _36, const 0_u64);
--         StorageDead(_36);
-+         _35 = Rem(_1, const 0_u64);
-          _34 = opaque::<u64>(move _35) -> [return: bb18, unwind unreachable];
-      }
-  
-      bb18: {
-          StorageDead(_35);
-          StorageDead(_34);
-          StorageLive(_38);
-          StorageLive(_39);
--         StorageLive(_40);
--         _40 = _1;
--         _41 = Eq(const 1_u64, const 0_u64);
--         assert(!move _41, "attempt to calculate the remainder of `{}` with a divisor of zero", _40) -> [success: bb19, unwind unreachable];
-+         assert(!_25, "attempt to calculate the remainder of `{}` with a divisor of zero", _1) -> [success: bb19, unwind unreachable];
-      }
-  
-      bb19: {
--         _39 = Rem(move _40, const 1_u64);
--         StorageDead(_40);
-+         _39 = Rem(_1, const 1_u64);
-          _38 = opaque::<u64>(move _39) -> [return: bb20, unwind unreachable];
-      }
-  
-      bb20: {
-          StorageDead(_39);
-          StorageDead(_38);
-          StorageLive(_42);
-          StorageLive(_43);
--         StorageLive(_44);
--         _44 = _1;
--         _45 = Eq(_44, const 0_u64);
--         assert(!move _45, "attempt to calculate the remainder of `{}` with a divisor of zero", const 0_u64) -> [success: bb21, unwind unreachable];
-+         assert(!_29, "attempt to calculate the remainder of `{}` with a divisor of zero", const 0_u64) -> [success: bb21, unwind unreachable];
-      }
-  
-      bb21: {
--         _43 = Rem(const 0_u64, move _44);
--         StorageDead(_44);
-+         _43 = Rem(const 0_u64, _1);
-          _42 = opaque::<u64>(move _43) -> [return: bb22, unwind unreachable];
-      }
-  
-      bb22: {
-          StorageDead(_43);
-          StorageDead(_42);
-          StorageLive(_46);
-          StorageLive(_47);
--         StorageLive(_48);
--         _48 = _1;
--         _49 = Eq(_48, const 0_u64);
--         assert(!move _49, "attempt to calculate the remainder of `{}` with a divisor of zero", const 1_u64) -> [success: bb23, unwind unreachable];
-+         assert(!_29, "attempt to calculate the remainder of `{}` with a divisor of zero", const 1_u64) -> [success: bb23, unwind unreachable];
-      }
-  
-      bb23: {
--         _47 = Rem(const 1_u64, move _48);
--         StorageDead(_48);
-+         _47 = Rem(const 1_u64, _1);
-          _46 = opaque::<u64>(move _47) -> [return: bb24, unwind unreachable];
-      }
-  
-      bb24: {
-          StorageDead(_47);
-          StorageDead(_46);
-          StorageLive(_50);
-          StorageLive(_51);
--         StorageLive(_52);
--         _52 = _1;
--         _51 = BitAnd(move _52, const 0_u64);
--         StorageDead(_52);
-+         _51 = BitAnd(_1, const 0_u64);
-          _50 = opaque::<u64>(move _51) -> [return: bb25, unwind unreachable];
-      }
-  
-      bb25: {
-          StorageDead(_51);
-          StorageDead(_50);
-          StorageLive(_53);
-          StorageLive(_54);
--         StorageLive(_55);
--         _55 = _1;
--         _54 = BitOr(move _55, const 0_u64);
--         StorageDead(_55);
-+         _54 = BitOr(_1, const 0_u64);
-          _53 = opaque::<u64>(move _54) -> [return: bb26, unwind unreachable];
-      }
-  
-      bb26: {
-          StorageDead(_54);
-          StorageDead(_53);
-          StorageLive(_56);
-          StorageLive(_57);
--         StorageLive(_58);
--         _58 = _1;
--         _57 = BitXor(move _58, const 0_u64);
--         StorageDead(_58);
-+         _57 = BitXor(_1, const 0_u64);
-          _56 = opaque::<u64>(move _57) -> [return: bb27, unwind unreachable];
-      }
-  
-      bb27: {
-          StorageDead(_57);
-          StorageDead(_56);
-          StorageLive(_59);
-          StorageLive(_60);
--         StorageLive(_61);
--         _61 = _1;
-          _62 = const 0_i32 as u32 (IntToInt);
--         _63 = Lt(move _62, const 64_u32);
--         assert(move _63, "attempt to shift right by `{}`, which would overflow", const 0_i32) -> [success: bb28, unwind unreachable];
-+         _63 = Lt(_62, const 64_u32);
-+         assert(_63, "attempt to shift right by `{}`, which would overflow", const 0_i32) -> [success: bb28, unwind unreachable];
-      }
-  
-      bb28: {
--         _60 = Shr(move _61, const 0_i32);
--         StorageDead(_61);
-+         _60 = Shr(_1, const 0_i32);
-          _59 = opaque::<u64>(move _60) -> [return: bb29, unwind unreachable];
-      }
-  
-      bb29: {
-          StorageDead(_60);
-          StorageDead(_59);
-          StorageLive(_64);
-          StorageLive(_65);
--         StorageLive(_66);
--         _66 = _1;
--         _67 = const 0_i32 as u32 (IntToInt);
--         _68 = Lt(move _67, const 64_u32);
--         assert(move _68, "attempt to shift left by `{}`, which would overflow", const 0_i32) -> [success: bb30, unwind unreachable];
-+         assert(_63, "attempt to shift left by `{}`, which would overflow", const 0_i32) -> [success: bb30, unwind unreachable];
-      }
-  
-      bb30: {
--         _65 = Shl(move _66, const 0_i32);
--         StorageDead(_66);
-+         _65 = Shl(_1, const 0_i32);
-          _64 = opaque::<u64>(move _65) -> [return: bb31, unwind unreachable];
-      }
-  
-      bb31: {
-          StorageDead(_65);
-          StorageDead(_64);
           _0 = const ();
           return;
       }

tests/mir-opt/gvn.arithmetic_checked.GVN.panic-unwind.diff

@@ -20,63 +20,12 @@
       let mut _15: u64;
       let mut _16: u64;
       let mut _17: (u64, bool);
-      let _18: ();
-      let mut _19: u64;
-      let mut _20: u64;
-      let mut _21: bool;
-      let _22: ();
-      let mut _23: u64;
-      let mut _24: u64;
-      let mut _25: bool;
-      let _26: ();
-      let mut _27: u64;
-      let mut _28: u64;
-      let mut _29: bool;
-      let _30: ();
-      let mut _31: u64;
-      let mut _32: u64;
-      let mut _33: bool;
-      let _34: ();
-      let mut _35: u64;
-      let mut _36: u64;
-      let mut _37: bool;
-      let _38: ();
-      let mut _39: u64;
-      let mut _40: u64;
-      let mut _41: bool;
-      let _42: ();
-      let mut _43: u64;
-      let mut _44: u64;
-      let mut _45: bool;
-      let _46: ();
-      let mut _47: u64;
-      let mut _48: u64;
-      let mut _49: bool;
-      let _50: ();
-      let mut _51: u64;
-      let mut _52: u64;
-      let _53: ();
-      let mut _54: u64;
-      let mut _55: u64;
-      let _56: ();
-      let mut _57: u64;
-      let mut _58: u64;
-      let _59: ();
-      let mut _60: u64;
-      let mut _61: u64;
-      let mut _62: u32;
-      let mut _63: bool;
-      let _64: ();
-      let mut _65: u64;
-      let mut _66: u64;
-      let mut _67: u32;
-      let mut _68: bool;
   
       bb0: {
           StorageLive(_2);
           StorageLive(_3);
--         StorageLive(_4);
--         _4 = _1;
+          StorageLive(_4);
+          _4 = _1;
 -         _5 = CheckedAdd(_4, const 0_u64);
 -         assert(!move (_5.1: bool), "attempt to compute `{} + {}`, which would overflow", move _4, const 0_u64) -> [success: bb1, unwind continue];
 +         _5 = CheckedAdd(_1, const 0_u64);
@@ -85,7 +34,7 @@
   
       bb1: {
           _3 = move (_5.0: u64);
--         StorageDead(_4);
+          StorageDead(_4);
           _2 = opaque::<u64>(move _3) -> [return: bb2, unwind continue];
       }
   
@@ -94,8 +43,8 @@
           StorageDead(_2);
           StorageLive(_6);
           StorageLive(_7);
--         StorageLive(_8);
--         _8 = _1;
+          StorageLive(_8);
+          _8 = _1;
 -         _9 = CheckedSub(_8, const 0_u64);
 -         assert(!move (_9.1: bool), "attempt to compute `{} - {}`, which would overflow", move _8, const 0_u64) -> [success: bb3, unwind continue];
 +         _9 = CheckedSub(_1, const 0_u64);
@@ -104,7 +53,7 @@
   
       bb3: {
           _7 = move (_9.0: u64);
--         StorageDead(_8);
+          StorageDead(_8);
           _6 = opaque::<u64>(move _7) -> [return: bb4, unwind continue];
       }
   
@@ -113,8 +62,8 @@
           StorageDead(_6);
           StorageLive(_10);
           StorageLive(_11);
--         StorageLive(_12);
--         _12 = _1;
+          StorageLive(_12);
+          _12 = _1;
 -         _13 = CheckedMul(_12, const 0_u64);
 -         assert(!move (_13.1: bool), "attempt to compute `{} * {}`, which would overflow", move _12, const 0_u64) -> [success: bb5, unwind continue];
 +         _13 = CheckedMul(_1, const 0_u64);
@@ -123,7 +72,7 @@
   
       bb5: {
           _11 = move (_13.0: u64);
--         StorageDead(_12);
+          StorageDead(_12);
           _10 = opaque::<u64>(move _11) -> [return: bb6, unwind continue];
       }
   
@@ -132,8 +81,8 @@
           StorageDead(_10);
           StorageLive(_14);
           StorageLive(_15);
--         StorageLive(_16);
--         _16 = _1;
+          StorageLive(_16);
+          _16 = _1;
 -         _17 = CheckedMul(_16, const 1_u64);
 -         assert(!move (_17.1: bool), "attempt to compute `{} * {}`, which would overflow", move _16, const 1_u64) -> [success: bb7, unwind continue];
 +         _17 = CheckedMul(_1, const 1_u64);
@@ -142,246 +91,13 @@
   
       bb7: {
           _15 = move (_17.0: u64);
--         StorageDead(_16);
+          StorageDead(_16);
           _14 = opaque::<u64>(move _15) -> [return: bb8, unwind continue];
       }
   
       bb8: {
           StorageDead(_15);
           StorageDead(_14);
-          StorageLive(_18);
-          StorageLive(_19);
--         StorageLive(_20);
--         _20 = _1;
-          _21 = Eq(const 0_u64, const 0_u64);
--         assert(!move _21, "attempt to divide `{}` by zero", _20) -> [success: bb9, unwind continue];
-+         assert(!_21, "attempt to divide `{}` by zero", _1) -> [success: bb9, unwind continue];
-      }
-  
-      bb9: {
--         _19 = Div(move _20, const 0_u64);
--         StorageDead(_20);
-+         _19 = Div(_1, const 0_u64);
-          _18 = opaque::<u64>(move _19) -> [return: bb10, unwind continue];
-      }
-  
-      bb10: {
-          StorageDead(_19);
-          StorageDead(_18);
-          StorageLive(_22);
-          StorageLive(_23);
--         StorageLive(_24);
--         _24 = _1;
-          _25 = Eq(const 1_u64, const 0_u64);
--         assert(!move _25, "attempt to divide `{}` by zero", _24) -> [success: bb11, unwind continue];
-+         assert(!_25, "attempt to divide `{}` by zero", _1) -> [success: bb11, unwind continue];
-      }
-  
-      bb11: {
--         _23 = Div(move _24, const 1_u64);
--         StorageDead(_24);
-+         _23 = Div(_1, const 1_u64);
-          _22 = opaque::<u64>(move _23) -> [return: bb12, unwind continue];
-      }
-  
-      bb12: {
-          StorageDead(_23);
-          StorageDead(_22);
-          StorageLive(_26);
-          StorageLive(_27);
--         StorageLive(_28);
--         _28 = _1;
--         _29 = Eq(_28, const 0_u64);
--         assert(!move _29, "attempt to divide `{}` by zero", const 0_u64) -> [success: bb13, unwind continue];
-+         _29 = Eq(_1, const 0_u64);
-+         assert(!_29, "attempt to divide `{}` by zero", const 0_u64) -> [success: bb13, unwind continue];
-      }
-  
-      bb13: {
--         _27 = Div(const 0_u64, move _28);
--         StorageDead(_28);
-+         _27 = Div(const 0_u64, _1);
-          _26 = opaque::<u64>(move _27) -> [return: bb14, unwind continue];
-      }
-  
-      bb14: {
-          StorageDead(_27);
-          StorageDead(_26);
-          StorageLive(_30);
-          StorageLive(_31);
--         StorageLive(_32);
--         _32 = _1;
--         _33 = Eq(_32, const 0_u64);
--         assert(!move _33, "attempt to divide `{}` by zero", const 1_u64) -> [success: bb15, unwind continue];
-+         assert(!_29, "attempt to divide `{}` by zero", const 1_u64) -> [success: bb15, unwind continue];
-      }
-  
-      bb15: {
--         _31 = Div(const 1_u64, move _32);
--         StorageDead(_32);
-+         _31 = Div(const 1_u64, _1);
-          _30 = opaque::<u64>(move _31) -> [return: bb16, unwind continue];
-      }
-  
-      bb16: {
-          StorageDead(_31);
-          StorageDead(_30);
-          StorageLive(_34);
-          StorageLive(_35);
--         StorageLive(_36);
--         _36 = _1;
--         _37 = Eq(const 0_u64, const 0_u64);
--         assert(!move _37, "attempt to calculate the remainder of `{}` with a divisor of zero", _36) -> [success: bb17, unwind continue];
-+         assert(!_21, "attempt to calculate the remainder of `{}` with a divisor of zero", _1) -> [success: bb17, unwind continue];
-      }
-  
-      bb17: {
--         _35 = Rem(move _36, const 0_u64);
--         StorageDead(_36);
-+         _35 = Rem(_1, const 0_u64);
-          _34 = opaque::<u64>(move _35) -> [return: bb18, unwind continue];
-      }
-  
-      bb18: {
-          StorageDead(_35);
-          StorageDead(_34);
-          StorageLive(_38);
-          StorageLive(_39);
--         StorageLive(_40);
--         _40 = _1;
--         _41 = Eq(const 1_u64, const 0_u64);
--         assert(!move _41, "attempt to calculate the remainder of `{}` with a divisor of zero", _40) -> [success: bb19, unwind continue];
-+         assert(!_25, "attempt to calculate the remainder of `{}` with a divisor of zero", _1) -> [success: bb19, unwind continue];
-      }
-  
-      bb19: {
--         _39 = Rem(move _40, const 1_u64);
--         StorageDead(_40);
-+         _39 = Rem(_1, const 1_u64);
-          _38 = opaque::<u64>(move _39) -> [return: bb20, unwind continue];
-      }
-  
-      bb20: {
-          StorageDead(_39);
-          StorageDead(_38);
-          StorageLive(_42);
-          StorageLive(_43);
--         StorageLive(_44);
--         _44 = _1;
--         _45 = Eq(_44, const 0_u64);
--         assert(!move _45, "attempt to calculate the remainder of `{}` with a divisor of zero", const 0_u64) -> [success: bb21, unwind continue];
-+         assert(!_29, "attempt to calculate the remainder of `{}` with a divisor of zero", const 0_u64) -> [success: bb21, unwind continue];
-      }
-  
-      bb21: {
--         _43 = Rem(const 0_u64, move _44);
--         StorageDead(_44);
-+         _43 = Rem(const 0_u64, _1);
-          _42 = opaque::<u64>(move _43) -> [return: bb22, unwind continue];
-      }
-  
-      bb22: {
-          StorageDead(_43);
-          StorageDead(_42);
-          StorageLive(_46);
-          StorageLive(_47);
--         StorageLive(_48);
--         _48 = _1;
--         _49 = Eq(_48, const 0_u64);
--         assert(!move _49, "attempt to calculate the remainder of `{}` with a divisor of zero", const 1_u64) -> [success: bb23, unwind continue];
-+         assert(!_29, "attempt to calculate the remainder of `{}` with a divisor of zero", const 1_u64) -> [success: bb23, unwind continue];
-      }
-  
-      bb23: {
--         _47 = Rem(const 1_u64, move _48);
--         StorageDead(_48);
-+         _47 = Rem(const 1_u64, _1);
-          _46 = opaque::<u64>(move _47) -> [return: bb24, unwind continue];
-      }
-  
-      bb24: {
-          StorageDead(_47);
-          StorageDead(_46);
-          StorageLive(_50);
-          StorageLive(_51);
--         StorageLive(_52);
--         _52 = _1;
--         _51 = BitAnd(move _52, const 0_u64);
--         StorageDead(_52);
-+         _51 = BitAnd(_1, const 0_u64);
-          _50 = opaque::<u64>(move _51) -> [return: bb25, unwind continue];
-      }
-  
-      bb25: {
-          StorageDead(_51);
-          StorageDead(_50);
-          StorageLive(_53);
-          StorageLive(_54);
--         StorageLive(_55);
--         _55 = _1;
--         _54 = BitOr(move _55, const 0_u64);
--         StorageDead(_55);
-+         _54 = BitOr(_1, const 0_u64);
-          _53 = opaque::<u64>(move _54) -> [return: bb26, unwind continue];
-      }
-  
-      bb26: {
-          StorageDead(_54);
-          StorageDead(_53);
-          StorageLive(_56);
-          StorageLive(_57);
--         StorageLive(_58);
--         _58 = _1;
--         _57 = BitXor(move _58, const 0_u64);
--         StorageDead(_58);
-+         _57 = BitXor(_1, const 0_u64);
-          _56 = opaque::<u64>(move _57) -> [return: bb27, unwind continue];
-      }
-  
-      bb27: {
-          StorageDead(_57);
-          StorageDead(_56);
-          StorageLive(_59);
-          StorageLive(_60);
--         StorageLive(_61);
--         _61 = _1;
-          _62 = const 0_i32 as u32 (IntToInt);
--         _63 = Lt(move _62, const 64_u32);
--         assert(move _63, "attempt to shift right by `{}`, which would overflow", const 0_i32) -> [success: bb28, unwind continue];
-+         _63 = Lt(_62, const 64_u32);
-+         assert(_63, "attempt to shift right by `{}`, which would overflow", const 0_i32) -> [success: bb28, unwind continue];
-      }
-  
-      bb28: {
--         _60 = Shr(move _61, const 0_i32);
--         StorageDead(_61);
-+         _60 = Shr(_1, const 0_i32);
-          _59 = opaque::<u64>(move _60) -> [return: bb29, unwind continue];
-      }
-  
-      bb29: {
-          StorageDead(_60);
-          StorageDead(_59);
-          StorageLive(_64);
-          StorageLive(_65);
--         StorageLive(_66);
--         _66 = _1;
--         _67 = const 0_i32 as u32 (IntToInt);
--         _68 = Lt(move _67, const 64_u32);
--         assert(move _68, "attempt to shift left by `{}`, which would overflow", const 0_i32) -> [success: bb30, unwind continue];
-+         assert(_63, "attempt to shift left by `{}`, which would overflow", const 0_i32) -> [success: bb30, unwind continue];
-      }
-  
-      bb30: {
--         _65 = Shl(move _66, const 0_i32);
--         StorageDead(_66);
-+         _65 = Shl(_1, const 0_i32);
-          _64 = opaque::<u64>(move _65) -> [return: bb31, unwind continue];
-      }
-  
-      bb31: {
-          StorageDead(_65);
-          StorageDead(_64);
           _0 = const ();
           return;
       }

tests/mir-opt/gvn.arithmetic_float.GVN.panic-abort.diff

@@ -37,11 +37,11 @@
       bb0: {
           StorageLive(_2);
           StorageLive(_3);
--         StorageLive(_4);
--         _4 = _1;
+          StorageLive(_4);
+          _4 = _1;
 -         _3 = Add(move _4, const 0f64);
--         StorageDead(_4);
 +         _3 = Add(_1, const 0f64);
+          StorageDead(_4);
           _2 = opaque::<f64>(move _3) -> [return: bb1, unwind unreachable];
       }
   
@@ -50,11 +50,11 @@
           StorageDead(_2);
           StorageLive(_5);
           StorageLive(_6);
--         StorageLive(_7);
--         _7 = _1;
+          StorageLive(_7);
+          _7 = _1;
 -         _6 = Sub(move _7, const 0f64);
--         StorageDead(_7);
 +         _6 = Sub(_1, const 0f64);
+          StorageDead(_7);
           _5 = opaque::<f64>(move _6) -> [return: bb2, unwind unreachable];
       }
   
@@ -63,11 +63,11 @@
           StorageDead(_5);
           StorageLive(_8);
           StorageLive(_9);
--         StorageLive(_10);
--         _10 = _1;
+          StorageLive(_10);
+          _10 = _1;
 -         _9 = Mul(move _10, const 0f64);
--         StorageDead(_10);
 +         _9 = Mul(_1, const 0f64);
+          StorageDead(_10);
           _8 = opaque::<f64>(move _9) -> [return: bb3, unwind unreachable];
       }
   
@@ -76,11 +76,11 @@
           StorageDead(_8);
           StorageLive(_11);
           StorageLive(_12);
--         StorageLive(_13);
--         _13 = _1;
+          StorageLive(_13);
+          _13 = _1;
 -         _12 = Div(move _13, const 0f64);
--         StorageDead(_13);
 +         _12 = Div(_1, const 0f64);
+          StorageDead(_13);
           _11 = opaque::<f64>(move _12) -> [return: bb4, unwind unreachable];
       }
   
@@ -89,11 +89,11 @@
           StorageDead(_11);
           StorageLive(_14);
           StorageLive(_15);
--         StorageLive(_16);
--         _16 = _1;
+          StorageLive(_16);
+          _16 = _1;
 -         _15 = Div(const 0f64, move _16);
--         StorageDead(_16);
 +         _15 = Div(const 0f64, _1);
+          StorageDead(_16);
           _14 = opaque::<f64>(move _15) -> [return: bb5, unwind unreachable];
       }
   
@@ -102,11 +102,11 @@
           StorageDead(_14);
           StorageLive(_17);
           StorageLive(_18);
--         StorageLive(_19);
--         _19 = _1;
+          StorageLive(_19);
+          _19 = _1;
 -         _18 = Rem(move _19, const 0f64);
--         StorageDead(_19);
 +         _18 = Rem(_1, const 0f64);
+          StorageDead(_19);
           _17 = opaque::<f64>(move _18) -> [return: bb6, unwind unreachable];
       }
   
@@ -115,11 +115,11 @@
           StorageDead(_17);
           StorageLive(_20);
           StorageLive(_21);
--         StorageLive(_22);
--         _22 = _1;
+          StorageLive(_22);
+          _22 = _1;
 -         _21 = Rem(const 0f64, move _22);
--         StorageDead(_22);
 +         _21 = Rem(const 0f64, _1);
+          StorageDead(_22);
           _20 = opaque::<f64>(move _21) -> [return: bb7, unwind unreachable];
       }
   
@@ -128,14 +128,14 @@
           StorageDead(_20);
           StorageLive(_23);
           StorageLive(_24);
--         StorageLive(_25);
--         _25 = _1;
--         StorageLive(_26);
--         _26 = _1;
+          StorageLive(_25);
+          _25 = _1;
+          StorageLive(_26);
+          _26 = _1;
 -         _24 = Eq(move _25, move _26);
--         StorageDead(_26);
--         StorageDead(_25);
 +         _24 = Eq(_1, _1);
+          StorageDead(_26);
+          StorageDead(_25);
           _23 = opaque::<bool>(move _24) -> [return: bb8, unwind unreachable];
       }
   
@@ -144,14 +144,14 @@
           StorageDead(_23);
           StorageLive(_27);
           StorageLive(_28);
--         StorageLive(_29);
--         _29 = _1;
--         StorageLive(_30);
--         _30 = _1;
+          StorageLive(_29);
+          _29 = _1;
+          StorageLive(_30);
+          _30 = _1;
 -         _28 = Ne(move _29, move _30);
--         StorageDead(_30);
--         StorageDead(_29);
 +         _28 = Ne(_1, _1);
+          StorageDead(_30);
+          StorageDead(_29);
           _27 = opaque::<bool>(move _28) -> [return: bb9, unwind unreachable];
       }
   

tests/mir-opt/gvn.arithmetic_float.GVN.panic-unwind.diff

@@ -37,11 +37,11 @@
       bb0: {
           StorageLive(_2);
           StorageLive(_3);
--         StorageLive(_4);
--         _4 = _1;
+          StorageLive(_4);
+          _4 = _1;
 -         _3 = Add(move _4, const 0f64);
--         StorageDead(_4);
 +         _3 = Add(_1, const 0f64);
+          StorageDead(_4);
           _2 = opaque::<f64>(move _3) -> [return: bb1, unwind continue];
       }
   
@@ -50,11 +50,11 @@
           StorageDead(_2);
           StorageLive(_5);
           StorageLive(_6);
--         StorageLive(_7);
--         _7 = _1;
+          StorageLive(_7);
+          _7 = _1;
 -         _6 = Sub(move _7, const 0f64);
--         StorageDead(_7);
 +         _6 = Sub(_1, const 0f64);
+          StorageDead(_7);
           _5 = opaque::<f64>(move _6) -> [return: bb2, unwind continue];
       }
   
@@ -63,11 +63,11 @@
           StorageDead(_5);
           StorageLive(_8);
           StorageLive(_9);
--         StorageLive(_10);
--         _10 = _1;
+          StorageLive(_10);
+          _10 = _1;
 -         _9 = Mul(move _10, const 0f64);
--         StorageDead(_10);
 +         _9 = Mul(_1, const 0f64);
+          StorageDead(_10);
           _8 = opaque::<f64>(move _9) -> [return: bb3, unwind continue];
       }
   
@@ -76,11 +76,11 @@
           StorageDead(_8);
           StorageLive(_11);
           StorageLive(_12);
--         StorageLive(_13);
--         _13 = _1;
+          StorageLive(_13);
+          _13 = _1;
 -         _12 = Div(move _13, const 0f64);
--         StorageDead(_13);
 +         _12 = Div(_1, const 0f64);
+          StorageDead(_13);
           _11 = opaque::<f64>(move _12) -> [return: bb4, unwind continue];
       }
   
@@ -89,11 +89,11 @@
           StorageDead(_11);
           StorageLive(_14);
           StorageLive(_15);
--         StorageLive(_16);
--         _16 = _1;
+          StorageLive(_16);
+          _16 = _1;
 -         _15 = Div(const 0f64, move _16);
--         StorageDead(_16);
 +         _15 = Div(const 0f64, _1);
+          StorageDead(_16);
           _14 = opaque::<f64>(move _15) -> [return: bb5, unwind continue];
       }
   
@@ -102,11 +102,11 @@
           StorageDead(_14);
           StorageLive(_17);
           StorageLive(_18);
--         StorageLive(_19);
--         _19 = _1;
+          StorageLive(_19);
+          _19 = _1;
 -         _18 = Rem(move _19, const 0f64);
--         StorageDead(_19);
 +         _18 = Rem(_1, const 0f64);
+          StorageDead(_19);
           _17 = opaque::<f64>(move _18) -> [return: bb6, unwind continue];
       }
   
@@ -115,11 +115,11 @@
           StorageDead(_17);
           StorageLive(_20);
           StorageLive(_21);
--         StorageLive(_22);
--         _22 = _1;
+          StorageLive(_22);
+          _22 = _1;
 -         _21 = Rem(const 0f64, move _22);
--         StorageDead(_22);
 +         _21 = Rem(const 0f64, _1);
+          StorageDead(_22);
           _20 = opaque::<f64>(move _21) -> [return: bb7, unwind continue];
       }
   
@@ -128,14 +128,14 @@
           StorageDead(_20);
           StorageLive(_23);
           StorageLive(_24);
--         StorageLive(_25);
--         _25 = _1;
--         StorageLive(_26);
--         _26 = _1;
+          StorageLive(_25);
+          _25 = _1;
+          StorageLive(_26);
+          _26 = _1;
 -         _24 = Eq(move _25, move _26);
--         StorageDead(_26);
--         StorageDead(_25);
 +         _24 = Eq(_1, _1);
+          StorageDead(_26);
+          StorageDead(_25);
           _23 = opaque::<bool>(move _24) -> [return: bb8, unwind continue];
       }
   
@@ -144,14 +144,14 @@
           StorageDead(_23);
           StorageLive(_27);
           StorageLive(_28);
--         StorageLive(_29);
--         _29 = _1;
--         StorageLive(_30);
--         _30 = _1;
+          StorageLive(_29);
+          _29 = _1;
+          StorageLive(_30);
+          _30 = _1;
 -         _28 = Ne(move _29, move _30);
--         StorageDead(_30);
--         StorageDead(_29);
 +         _28 = Ne(_1, _1);
+          StorageDead(_30);
+          StorageDead(_29);
           _27 = opaque::<bool>(move _28) -> [return: bb9, unwind continue];
       }
   

tests/mir-opt/gvn.cast.GVN.panic-abort.diff

@@ -105,19 +105,24 @@
   
       bb0: {
 -         StorageLive(_1);
++         nop;
           _1 = const 1_i64;
 -         StorageLive(_2);
++         nop;
           _2 = const 1_u64;
 -         StorageLive(_3);
++         nop;
           _3 = const 1f64;
           StorageLive(_4);
           StorageLive(_5);
--         StorageLive(_6);
+          StorageLive(_6);
 -         _6 = _1;
 -         _5 = move _6 as u8 (IntToInt);
--         StorageDead(_6);
-+         _5 = const 1_i64 as u8 (IntToInt);
-          _4 = opaque::<u8>(move _5) -> [return: bb1, unwind unreachable];
++         _6 = const 1_i64;
++         _5 = const 1_u8;
+          StorageDead(_6);
+-         _4 = opaque::<u8>(move _5) -> [return: bb1, unwind unreachable];
++         _4 = opaque::<u8>(const 1_u8) -> [return: bb1, unwind unreachable];
       }
   
       bb1: {
@@ -125,12 +130,14 @@
           StorageDead(_4);
           StorageLive(_7);
           StorageLive(_8);
--         StorageLive(_9);
+          StorageLive(_9);
 -         _9 = _1;
 -         _8 = move _9 as u16 (IntToInt);
--         StorageDead(_9);
-+         _8 = const 1_i64 as u16 (IntToInt);
-          _7 = opaque::<u16>(move _8) -> [return: bb2, unwind unreachable];
++         _9 = const 1_i64;
++         _8 = const 1_u16;
+          StorageDead(_9);
+-         _7 = opaque::<u16>(move _8) -> [return: bb2, unwind unreachable];
++         _7 = opaque::<u16>(const 1_u16) -> [return: bb2, unwind unreachable];
       }
   
       bb2: {
@@ -138,12 +145,14 @@
           StorageDead(_7);
           StorageLive(_10);
           StorageLive(_11);
--         StorageLive(_12);
+          StorageLive(_12);
 -         _12 = _1;
 -         _11 = move _12 as u32 (IntToInt);
--         StorageDead(_12);
-+         _11 = const 1_i64 as u32 (IntToInt);
-          _10 = opaque::<u32>(move _11) -> [return: bb3, unwind unreachable];
++         _12 = const 1_i64;
++         _11 = const 1_u32;
+          StorageDead(_12);
+-         _10 = opaque::<u32>(move _11) -> [return: bb3, unwind unreachable];
++         _10 = opaque::<u32>(const 1_u32) -> [return: bb3, unwind unreachable];
       }
   
       bb3: {
@@ -151,12 +160,14 @@
           StorageDead(_10);
           StorageLive(_13);
           StorageLive(_14);
--         StorageLive(_15);
+          StorageLive(_15);
 -         _15 = _1;
 -         _14 = move _15 as u64 (IntToInt);
--         StorageDead(_15);
-+         _14 = const 1_i64 as u64 (IntToInt);
-          _13 = opaque::<u64>(move _14) -> [return: bb4, unwind unreachable];
++         _15 = const 1_i64;
++         _14 = const 1_u64;
+          StorageDead(_15);
+-         _13 = opaque::<u64>(move _14) -> [return: bb4, unwind unreachable];
++         _13 = opaque::<u64>(const 1_u64) -> [return: bb4, unwind unreachable];
       }
   
       bb4: {
@@ -164,12 +175,14 @@
           StorageDead(_13);
           StorageLive(_16);
           StorageLive(_17);
--         StorageLive(_18);
+          StorageLive(_18);
 -         _18 = _1;
 -         _17 = move _18 as i8 (IntToInt);
--         StorageDead(_18);
-+         _17 = const 1_i64 as i8 (IntToInt);
-          _16 = opaque::<i8>(move _17) -> [return: bb5, unwind unreachable];
++         _18 = const 1_i64;
++         _17 = const 1_i8;
+          StorageDead(_18);
+-         _16 = opaque::<i8>(move _17) -> [return: bb5, unwind unreachable];
++         _16 = opaque::<i8>(const 1_i8) -> [return: bb5, unwind unreachable];
       }
   
       bb5: {
@@ -177,12 +190,14 @@
           StorageDead(_16);
           StorageLive(_19);
           StorageLive(_20);
--         StorageLive(_21);
+          StorageLive(_21);
 -         _21 = _1;
 -         _20 = move _21 as i16 (IntToInt);
--         StorageDead(_21);
-+         _20 = const 1_i64 as i16 (IntToInt);
-          _19 = opaque::<i16>(move _20) -> [return: bb6, unwind unreachable];
++         _21 = const 1_i64;
++         _20 = const 1_i16;
+          StorageDead(_21);
+-         _19 = opaque::<i16>(move _20) -> [return: bb6, unwind unreachable];
++         _19 = opaque::<i16>(const 1_i16) -> [return: bb6, unwind unreachable];
       }
   
       bb6: {
@@ -190,35 +205,40 @@
           StorageDead(_19);
           StorageLive(_22);
           StorageLive(_23);
--         StorageLive(_24);
+          StorageLive(_24);
 -         _24 = _1;
 -         _23 = move _24 as i32 (IntToInt);
--         StorageDead(_24);
-+         _23 = const 1_i64 as i32 (IntToInt);
-          _22 = opaque::<i32>(move _23) -> [return: bb7, unwind unreachable];
++         _24 = const 1_i64;
++         _23 = const 1_i32;
+          StorageDead(_24);
+-         _22 = opaque::<i32>(move _23) -> [return: bb7, unwind unreachable];
++         _22 = opaque::<i32>(const 1_i32) -> [return: bb7, unwind unreachable];
       }
   
       bb7: {
           StorageDead(_23);
           StorageDead(_22);
           StorageLive(_25);
--         StorageLive(_26);
+          StorageLive(_26);
 -         _26 = _1;
 -         _25 = opaque::<i64>(move _26) -> [return: bb8, unwind unreachable];
++         _26 = const 1_i64;
 +         _25 = opaque::<i64>(const 1_i64) -> [return: bb8, unwind unreachable];
       }
   
       bb8: {
--         StorageDead(_26);
+          StorageDead(_26);
           StorageDead(_25);
           StorageLive(_27);
           StorageLive(_28);
--         StorageLive(_29);
+          StorageLive(_29);
 -         _29 = _1;
 -         _28 = move _29 as f32 (IntToFloat);
--         StorageDead(_29);
-+         _28 = const 1_i64 as f32 (IntToFloat);
-          _27 = opaque::<f32>(move _28) -> [return: bb9, unwind unreachable];
++         _29 = const 1_i64;
++         _28 = const 1f32;
+          StorageDead(_29);
+-         _27 = opaque::<f32>(move _28) -> [return: bb9, unwind unreachable];
++         _27 = opaque::<f32>(const 1f32) -> [return: bb9, unwind unreachable];
       }
   
       bb9: {
@@ -226,12 +246,14 @@
           StorageDead(_27);
           StorageLive(_30);
           StorageLive(_31);
--         StorageLive(_32);
+          StorageLive(_32);
 -         _32 = _1;
 -         _31 = move _32 as f64 (IntToFloat);
--         StorageDead(_32);
-+         _31 = const 1_i64 as f64 (IntToFloat);
-          _30 = opaque::<f64>(move _31) -> [return: bb10, unwind unreachable];
++         _32 = const 1_i64;
++         _31 = const 1f64;
+          StorageDead(_32);
+-         _30 = opaque::<f64>(move _31) -> [return: bb10, unwind unreachable];
++         _30 = opaque::<f64>(const 1f64) -> [return: bb10, unwind unreachable];
       }
   
       bb10: {
@@ -239,12 +261,14 @@
           StorageDead(_30);
           StorageLive(_33);
           StorageLive(_34);
--         StorageLive(_35);
+          StorageLive(_35);
 -         _35 = _2;
 -         _34 = move _35 as u8 (IntToInt);
--         StorageDead(_35);
-+         _34 = const 1_u64 as u8 (IntToInt);
-          _33 = opaque::<u8>(move _34) -> [return: bb11, unwind unreachable];
++         _35 = const 1_u64;
++         _34 = const 1_u8;
+          StorageDead(_35);
+-         _33 = opaque::<u8>(move _34) -> [return: bb11, unwind unreachable];
++         _33 = opaque::<u8>(const 1_u8) -> [return: bb11, unwind unreachable];
       }
   
       bb11: {
@@ -252,12 +276,14 @@
           StorageDead(_33);
           StorageLive(_36);
           StorageLive(_37);
--         StorageLive(_38);
+          StorageLive(_38);
 -         _38 = _2;
 -         _37 = move _38 as u16 (IntToInt);
--         StorageDead(_38);
-+         _37 = const 1_u64 as u16 (IntToInt);
-          _36 = opaque::<u16>(move _37) -> [return: bb12, unwind unreachable];
++         _38 = const 1_u64;
++         _37 = const 1_u16;
+          StorageDead(_38);
+-         _36 = opaque::<u16>(move _37) -> [return: bb12, unwind unreachable];
++         _36 = opaque::<u16>(const 1_u16) -> [return: bb12, unwind unreachable];
       }
   
       bb12: {
@@ -265,35 +291,40 @@
           StorageDead(_36);
           StorageLive(_39);
           StorageLive(_40);
--         StorageLive(_41);
+          StorageLive(_41);
 -         _41 = _2;
 -         _40 = move _41 as u32 (IntToInt);
--         StorageDead(_41);
-+         _40 = const 1_u64 as u32 (IntToInt);
-          _39 = opaque::<u32>(move _40) -> [return: bb13, unwind unreachable];
++         _41 = const 1_u64;
++         _40 = const 1_u32;
+          StorageDead(_41);
+-         _39 = opaque::<u32>(move _40) -> [return: bb13, unwind unreachable];
++         _39 = opaque::<u32>(const 1_u32) -> [return: bb13, unwind unreachable];
       }
   
       bb13: {
           StorageDead(_40);
           StorageDead(_39);
           StorageLive(_42);
--         StorageLive(_43);
+          StorageLive(_43);
 -         _43 = _2;
 -         _42 = opaque::<u64>(move _43) -> [return: bb14, unwind unreachable];
++         _43 = const 1_u64;
 +         _42 = opaque::<u64>(const 1_u64) -> [return: bb14, unwind unreachable];
       }
   
       bb14: {
--         StorageDead(_43);
+          StorageDead(_43);
           StorageDead(_42);
           StorageLive(_44);
           StorageLive(_45);
--         StorageLive(_46);
+          StorageLive(_46);
 -         _46 = _2;
 -         _45 = move _46 as i8 (IntToInt);
--         StorageDead(_46);
-+         _45 = const 1_u64 as i8 (IntToInt);
-          _44 = opaque::<i8>(move _45) -> [return: bb15, unwind unreachable];
++         _46 = const 1_u64;
++         _45 = const 1_i8;
+          StorageDead(_46);
+-         _44 = opaque::<i8>(move _45) -> [return: bb15, unwind unreachable];
++         _44 = opaque::<i8>(const 1_i8) -> [return: bb15, unwind unreachable];
       }
   
       bb15: {
@@ -301,12 +332,14 @@
           StorageDead(_44);
           StorageLive(_47);
           StorageLive(_48);
--         StorageLive(_49);
+          StorageLive(_49);
 -         _49 = _2;
 -         _48 = move _49 as i16 (IntToInt);
--         StorageDead(_49);
-+         _48 = const 1_u64 as i16 (IntToInt);
-          _47 = opaque::<i16>(move _48) -> [return: bb16, unwind unreachable];
++         _49 = const 1_u64;
++         _48 = const 1_i16;
+          StorageDead(_49);
+-         _47 = opaque::<i16>(move _48) -> [return: bb16, unwind unreachable];
++         _47 = opaque::<i16>(const 1_i16) -> [return: bb16, unwind unreachable];
       }
   
       bb16: {
@@ -314,12 +347,14 @@
           StorageDead(_47);
           StorageLive(_50);
           StorageLive(_51);
--         StorageLive(_52);
+          StorageLive(_52);
 -         _52 = _2;
 -         _51 = move _52 as i32 (IntToInt);
--         StorageDead(_52);
-+         _51 = const 1_u64 as i32 (IntToInt);
-          _50 = opaque::<i32>(move _51) -> [return: bb17, unwind unreachable];
++         _52 = const 1_u64;
++         _51 = const 1_i32;
+          StorageDead(_52);
+-         _50 = opaque::<i32>(move _51) -> [return: bb17, unwind unreachable];
++         _50 = opaque::<i32>(const 1_i32) -> [return: bb17, unwind unreachable];
       }
   
       bb17: {
@@ -327,12 +362,14 @@
           StorageDead(_50);
           StorageLive(_53);
           StorageLive(_54);
--         StorageLive(_55);
+          StorageLive(_55);
 -         _55 = _2;
 -         _54 = move _55 as i64 (IntToInt);
--         StorageDead(_55);
-+         _54 = const 1_u64 as i64 (IntToInt);
-          _53 = opaque::<i64>(move _54) -> [return: bb18, unwind unreachable];
++         _55 = const 1_u64;
++         _54 = const 1_i64;
+          StorageDead(_55);
+-         _53 = opaque::<i64>(move _54) -> [return: bb18, unwind unreachable];
++         _53 = opaque::<i64>(const 1_i64) -> [return: bb18, unwind unreachable];
       }
   
       bb18: {
@@ -340,12 +377,14 @@
           StorageDead(_53);
           StorageLive(_56);
           StorageLive(_57);
--         StorageLive(_58);
+          StorageLive(_58);
 -         _58 = _2;
 -         _57 = move _58 as f32 (IntToFloat);
--         StorageDead(_58);
-+         _57 = const 1_u64 as f32 (IntToFloat);
-          _56 = opaque::<f32>(move _57) -> [return: bb19, unwind unreachable];
++         _58 = const 1_u64;
++         _57 = const 1f32;
+          StorageDead(_58);
+-         _56 = opaque::<f32>(move _57) -> [return: bb19, unwind unreachable];
++         _56 = opaque::<f32>(const 1f32) -> [return: bb19, unwind unreachable];
       }
   
       bb19: {
@@ -353,12 +392,14 @@
           StorageDead(_56);
           StorageLive(_59);
           StorageLive(_60);
--         StorageLive(_61);
+          StorageLive(_61);
 -         _61 = _2;
 -         _60 = move _61 as f64 (IntToFloat);
--         StorageDead(_61);
-+         _60 = const 1_u64 as f64 (IntToFloat);
-          _59 = opaque::<f64>(move _60) -> [return: bb20, unwind unreachable];
++         _61 = const 1_u64;
++         _60 = const 1f64;
+          StorageDead(_61);
+-         _59 = opaque::<f64>(move _60) -> [return: bb20, unwind unreachable];
++         _59 = opaque::<f64>(const 1f64) -> [return: bb20, unwind unreachable];
       }
   
       bb20: {
@@ -366,12 +407,14 @@
           StorageDead(_59);
           StorageLive(_62);
           StorageLive(_63);
--         StorageLive(_64);
+          StorageLive(_64);
 -         _64 = _3;
 -         _63 = move _64 as u8 (FloatToInt);
--         StorageDead(_64);
-+         _63 = const 1f64 as u8 (FloatToInt);
-          _62 = opaque::<u8>(move _63) -> [return: bb21, unwind unreachable];
++         _64 = const 1f64;
++         _63 = const 1_u8;
+          StorageDead(_64);
+-         _62 = opaque::<u8>(move _63) -> [return: bb21, unwind unreachable];
++         _62 = opaque::<u8>(const 1_u8) -> [return: bb21, unwind unreachable];
       }
   
       bb21: {
@@ -379,12 +422,14 @@
           StorageDead(_62);
           StorageLive(_65);
           StorageLive(_66);
--         StorageLive(_67);
+          StorageLive(_67);
 -         _67 = _3;
 -         _66 = move _67 as u16 (FloatToInt);
--         StorageDead(_67);
-+         _66 = const 1f64 as u16 (FloatToInt);
-          _65 = opaque::<u16>(move _66) -> [return: bb22, unwind unreachable];
++         _67 = const 1f64;
++         _66 = const 1_u16;
+          StorageDead(_67);
+-         _65 = opaque::<u16>(move _66) -> [return: bb22, unwind unreachable];
++         _65 = opaque::<u16>(const 1_u16) -> [return: bb22, unwind unreachable];
       }
   
       bb22: {
@@ -392,12 +437,14 @@
           StorageDead(_65);
           StorageLive(_68);
           StorageLive(_69);
--         StorageLive(_70);
+          StorageLive(_70);
 -         _70 = _3;
 -         _69 = move _70 as u32 (FloatToInt);
--         StorageDead(_70);
-+         _69 = const 1f64 as u32 (FloatToInt);
-          _68 = opaque::<u32>(move _69) -> [return: bb23, unwind unreachable];
++         _70 = const 1f64;
++         _69 = const 1_u32;
+          StorageDead(_70);
+-         _68 = opaque::<u32>(move _69) -> [return: bb23, unwind unreachable];
++         _68 = opaque::<u32>(const 1_u32) -> [return: bb23, unwind unreachable];
       }
   
       bb23: {
@@ -405,12 +452,14 @@
           StorageDead(_68);
           StorageLive(_71);
           StorageLive(_72);
--         StorageLive(_73);
+          StorageLive(_73);
 -         _73 = _3;
 -         _72 = move _73 as u64 (FloatToInt);
--         StorageDead(_73);
-+         _72 = const 1f64 as u64 (FloatToInt);
-          _71 = opaque::<u64>(move _72) -> [return: bb24, unwind unreachable];
++         _73 = const 1f64;
++         _72 = const 1_u64;
+          StorageDead(_73);
+-         _71 = opaque::<u64>(move _72) -> [return: bb24, unwind unreachable];
++         _71 = opaque::<u64>(const 1_u64) -> [return: bb24, unwind unreachable];
       }
   
       bb24: {
@@ -418,12 +467,14 @@
           StorageDead(_71);
           StorageLive(_74);
           StorageLive(_75);
--         StorageLive(_76);
+          StorageLive(_76);
 -         _76 = _3;
 -         _75 = move _76 as i8 (FloatToInt);
--         StorageDead(_76);
-+         _75 = const 1f64 as i8 (FloatToInt);
-          _74 = opaque::<i8>(move _75) -> [return: bb25, unwind unreachable];
++         _76 = const 1f64;
++         _75 = const 1_i8;
+          StorageDead(_76);
+-         _74 = opaque::<i8>(move _75) -> [return: bb25, unwind unreachable];
++         _74 = opaque::<i8>(const 1_i8) -> [return: bb25, unwind unreachable];
       }
   
       bb25: {
@@ -431,12 +482,14 @@
           StorageDead(_74);
           StorageLive(_77);
           StorageLive(_78);
--         StorageLive(_79);
+          StorageLive(_79);
 -         _79 = _3;
 -         _78 = move _79 as i16 (FloatToInt);
--         StorageDead(_79);
-+         _78 = const 1f64 as i16 (FloatToInt);
-          _77 = opaque::<i16>(move _78) -> [return: bb26, unwind unreachable];
++         _79 = const 1f64;
++         _78 = const 1_i16;
+          StorageDead(_79);
+-         _77 = opaque::<i16>(move _78) -> [return: bb26, unwind unreachable];
++         _77 = opaque::<i16>(const 1_i16) -> [return: bb26, unwind unreachable];
       }
   
       bb26: {
@@ -444,12 +497,14 @@
           StorageDead(_77);
           StorageLive(_80);
           StorageLive(_81);
--         StorageLive(_82);
+          StorageLive(_82);
 -         _82 = _3;
 -         _81 = move _82 as i32 (FloatToInt);
--         StorageDead(_82);
-+         _81 = const 1f64 as i32 (FloatToInt);
-          _80 = opaque::<i32>(move _81) -> [return: bb27, unwind unreachable];
++         _82 = const 1f64;
++         _81 = const 1_i32;
+          StorageDead(_82);
+-         _80 = opaque::<i32>(move _81) -> [return: bb27, unwind unreachable];
++         _80 = opaque::<i32>(const 1_i32) -> [return: bb27, unwind unreachable];
       }
   
       bb27: {
@@ -457,12 +512,14 @@
           StorageDead(_80);
           StorageLive(_83);
           StorageLive(_84);
--         StorageLive(_85);
+          StorageLive(_85);
 -         _85 = _3;
 -         _84 = move _85 as i64 (FloatToInt);
--         StorageDead(_85);
-+         _84 = const 1f64 as i64 (FloatToInt);
-          _83 = opaque::<i64>(move _84) -> [return: bb28, unwind unreachable];
++         _85 = const 1f64;
++         _84 = const 1_i64;
+          StorageDead(_85);
+-         _83 = opaque::<i64>(move _84) -> [return: bb28, unwind unreachable];
++         _83 = opaque::<i64>(const 1_i64) -> [return: bb28, unwind unreachable];
       }
   
       bb28: {
@@ -470,31 +527,37 @@
           StorageDead(_83);
           StorageLive(_86);
           StorageLive(_87);
--         StorageLive(_88);
+          StorageLive(_88);
 -         _88 = _3;
 -         _87 = move _88 as f32 (FloatToFloat);
--         StorageDead(_88);
-+         _87 = const 1f64 as f32 (FloatToFloat);
-          _86 = opaque::<f32>(move _87) -> [return: bb29, unwind unreachable];
++         _88 = const 1f64;
++         _87 = const 1f32;
+          StorageDead(_88);
+-         _86 = opaque::<f32>(move _87) -> [return: bb29, unwind unreachable];
++         _86 = opaque::<f32>(const 1f32) -> [return: bb29, unwind unreachable];
       }
   
       bb29: {
           StorageDead(_87);
           StorageDead(_86);
           StorageLive(_89);
--         StorageLive(_90);
+          StorageLive(_90);
 -         _90 = _3;
 -         _89 = opaque::<f64>(move _90) -> [return: bb30, unwind unreachable];
++         _90 = const 1f64;
 +         _89 = opaque::<f64>(const 1f64) -> [return: bb30, unwind unreachable];
       }
   
       bb30: {
--         StorageDead(_90);
+          StorageDead(_90);
           StorageDead(_89);
           _0 = const ();
 -         StorageDead(_3);
 -         StorageDead(_2);
 -         StorageDead(_1);
++         nop;
++         nop;
++         nop;
           return;
       }
   }

tests/mir-opt/gvn.cast.GVN.panic-unwind.diff

@@ -105,19 +105,24 @@
   
       bb0: {
 -         StorageLive(_1);
++         nop;
           _1 = const 1_i64;
 -         StorageLive(_2);
++         nop;
           _2 = const 1_u64;
 -         StorageLive(_3);
++         nop;
           _3 = const 1f64;
           StorageLive(_4);
           StorageLive(_5);
--         StorageLive(_6);
+          StorageLive(_6);
 -         _6 = _1;
 -         _5 = move _6 as u8 (IntToInt);
--         StorageDead(_6);
-+         _5 = const 1_i64 as u8 (IntToInt);
-          _4 = opaque::<u8>(move _5) -> [return: bb1, unwind continue];
++         _6 = const 1_i64;
++         _5 = const 1_u8;
+          StorageDead(_6);
+-         _4 = opaque::<u8>(move _5) -> [return: bb1, unwind continue];
++         _4 = opaque::<u8>(const 1_u8) -> [return: bb1, unwind continue];
       }
   
       bb1: {
@@ -125,12 +130,14 @@
           StorageDead(_4);
           StorageLive(_7);
           StorageLive(_8);
--         StorageLive(_9);
+          StorageLive(_9);
 -         _9 = _1;
 -         _8 = move _9 as u16 (IntToInt);
--         StorageDead(_9);
-+         _8 = const 1_i64 as u16 (IntToInt);
-          _7 = opaque::<u16>(move _8) -> [return: bb2, unwind continue];
++         _9 = const 1_i64;
++         _8 = const 1_u16;
+          StorageDead(_9);
+-         _7 = opaque::<u16>(move _8) -> [return: bb2, unwind continue];
++         _7 = opaque::<u16>(const 1_u16) -> [return: bb2, unwind continue];
       }
   
       bb2: {
@@ -138,12 +145,14 @@
           StorageDead(_7);
           StorageLive(_10);
           StorageLive(_11);
--         StorageLive(_12);
+          StorageLive(_12);
 -         _12 = _1;
 -         _11 = move _12 as u32 (IntToInt);
--         StorageDead(_12);
-+         _11 = const 1_i64 as u32 (IntToInt);
-          _10 = opaque::<u32>(move _11) -> [return: bb3, unwind continue];
++         _12 = const 1_i64;
++         _11 = const 1_u32;
+          StorageDead(_12);
+-         _10 = opaque::<u32>(move _11) -> [return: bb3, unwind continue];
++         _10 = opaque::<u32>(const 1_u32) -> [return: bb3, unwind continue];
       }
   
       bb3: {
@@ -151,12 +160,14 @@
           StorageDead(_10);
           StorageLive(_13);
           StorageLive(_14);
--         StorageLive(_15);
+          StorageLive(_15);
 -         _15 = _1;
 -         _14 = move _15 as u64 (IntToInt);
--         StorageDead(_15);
-+         _14 = const 1_i64 as u64 (IntToInt);
-          _13 = opaque::<u64>(move _14) -> [return: bb4, unwind continue];
++         _15 = const 1_i64;
++         _14 = const 1_u64;
+          StorageDead(_15);
+-         _13 = opaque::<u64>(move _14) -> [return: bb4, unwind continue];
++         _13 = opaque::<u64>(const 1_u64) -> [return: bb4, unwind continue];
       }
   
       bb4: {
@@ -164,12 +175,14 @@
           StorageDead(_13);
           StorageLive(_16);
           StorageLive(_17);
--         StorageLive(_18);
+          StorageLive(_18);
 -         _18 = _1;
 -         _17 = move _18 as i8 (IntToInt);
--         StorageDead(_18);
-+         _17 = const 1_i64 as i8 (IntToInt);
-          _16 = opaque::<i8>(move _17) -> [return: bb5, unwind continue];
++         _18 = const 1_i64;
++         _17 = const 1_i8;
+          StorageDead(_18);
+-         _16 = opaque::<i8>(move _17) -> [return: bb5, unwind continue];
++         _16 = opaque::<i8>(const 1_i8) -> [return: bb5, unwind continue];
       }
   
       bb5: {
@@ -177,12 +190,14 @@
           StorageDead(_16);
           StorageLive(_19);
           StorageLive(_20);
--         StorageLive(_21);
+          StorageLive(_21);
 -         _21 = _1;
 -         _20 = move _21 as i16 (IntToInt);
--         StorageDead(_21);
-+         _20 = const 1_i64 as i16 (IntToInt);
-          _19 = opaque::<i16>(move _20) -> [return: bb6, unwind continue];
++         _21 = const 1_i64;
++         _20 = const 1_i16;
+          StorageDead(_21);
+-         _19 = opaque::<i16>(move _20) -> [return: bb6, unwind continue];
++         _19 = opaque::<i16>(const 1_i16) -> [return: bb6, unwind continue];
       }
   
       bb6: {
@@ -190,35 +205,40 @@
           StorageDead(_19);
           StorageLive(_22);
           StorageLive(_23);
--         StorageLive(_24);
+          StorageLive(_24);
 -         _24 = _1;
 -         _23 = move _24 as i32 (IntToInt);
--         StorageDead(_24);
-+         _23 = const 1_i64 as i32 (IntToInt);
-          _22 = opaque::<i32>(move _23) -> [return: bb7, unwind continue];
++         _24 = const 1_i64;
++         _23 = const 1_i32;
+          StorageDead(_24);
+-         _22 = opaque::<i32>(move _23) -> [return: bb7, unwind continue];
++         _22 = opaque::<i32>(const 1_i32) -> [return: bb7, unwind continue];
       }
   
       bb7: {
           StorageDead(_23);
           StorageDead(_22);
           StorageLive(_25);
--         StorageLive(_26);
+          StorageLive(_26);
 -         _26 = _1;
 -         _25 = opaque::<i64>(move _26) -> [return: bb8, unwind continue];
++         _26 = const 1_i64;
 +         _25 = opaque::<i64>(const 1_i64) -> [return: bb8, unwind continue];
       }
   
       bb8: {
--         StorageDead(_26);
+          StorageDead(_26);
           StorageDead(_25);
           StorageLive(_27);
           StorageLive(_28);
--         StorageLive(_29);
+          StorageLive(_29);
 -         _29 = _1;
 -         _28 = move _29 as f32 (IntToFloat);
--         StorageDead(_29);
-+         _28 = const 1_i64 as f32 (IntToFloat);
-          _27 = opaque::<f32>(move _28) -> [return: bb9, unwind continue];
++         _29 = const 1_i64;
++         _28 = const 1f32;
+          StorageDead(_29);
+-         _27 = opaque::<f32>(move _28) -> [return: bb9, unwind continue];
++         _27 = opaque::<f32>(const 1f32) -> [return: bb9, unwind continue];
       }
   
       bb9: {
@@ -226,12 +246,14 @@
           StorageDead(_27);
           StorageLive(_30);
           StorageLive(_31);
--         StorageLive(_32);
+          StorageLive(_32);
 -         _32 = _1;
 -         _31 = move _32 as f64 (IntToFloat);
--         StorageDead(_32);
-+         _31 = const 1_i64 as f64 (IntToFloat);
-          _30 = opaque::<f64>(move _31) -> [return: bb10, unwind continue];
++         _32 = const 1_i64;
++         _31 = const 1f64;
+          StorageDead(_32);
+-         _30 = opaque::<f64>(move _31) -> [return: bb10, unwind continue];
++         _30 = opaque::<f64>(const 1f64) -> [return: bb10, unwind continue];
       }
   
       bb10: {
@@ -239,12 +261,14 @@
           StorageDead(_30);
           StorageLive(_33);
           StorageLive(_34);
--         StorageLive(_35);
+          StorageLive(_35);
 -         _35 = _2;
 -         _34 = move _35 as u8 (IntToInt);
--         StorageDead(_35);
-+         _34 = const 1_u64 as u8 (IntToInt);
-          _33 = opaque::<u8>(move _34) -> [return: bb11, unwind continue];
++         _35 = const 1_u64;
++         _34 = const 1_u8;
+          StorageDead(_35);
+-         _33 = opaque::<u8>(move _34) -> [return: bb11, unwind continue];
++         _33 = opaque::<u8>(const 1_u8) -> [return: bb11, unwind continue];
       }
   
       bb11: {
@@ -252,12 +276,14 @@
           StorageDead(_33);
           StorageLive(_36);
           StorageLive(_37);
--         StorageLive(_38);
+          StorageLive(_38);
 -         _38 = _2;
 -         _37 = move _38 as u16 (IntToInt);
--         StorageDead(_38);
-+         _37 = const 1_u64 as u16 (IntToInt);
-          _36 = opaque::<u16>(move _37) -> [return: bb12, unwind continue];
++         _38 = const 1_u64;
++         _37 = const 1_u16;
+          StorageDead(_38);
+-         _36 = opaque::<u16>(move _37) -> [return: bb12, unwind continue];
++         _36 = opaque::<u16>(const 1_u16) -> [return: bb12, unwind continue];
       }
   
       bb12: {
@@ -265,35 +291,40 @@
           StorageDead(_36);
           StorageLive(_39);
           StorageLive(_40);
--         StorageLive(_41);
+          StorageLive(_41);
 -         _41 = _2;
 -         _40 = move _41 as u32 (IntToInt);
--         StorageDead(_41);
-+         _40 = const 1_u64 as u32 (IntToInt);
-          _39 = opaque::<u32>(move _40) -> [return: bb13, unwind continue];
++         _41 = const 1_u64;
++         _40 = const 1_u32;
+          StorageDead(_41);
+-         _39 = opaque::<u32>(move _40) -> [return: bb13, unwind continue];
++         _39 = opaque::<u32>(const 1_u32) -> [return: bb13, unwind continue];
       }
   
       bb13: {
           StorageDead(_40);
           StorageDead(_39);
           StorageLive(_42);
--         StorageLive(_43);
+          StorageLive(_43);
 -         _43 = _2;
 -         _42 = opaque::<u64>(move _43) -> [return: bb14, unwind continue];
++         _43 = const 1_u64;
 +         _42 = opaque::<u64>(const 1_u64) -> [return: bb14, unwind continue];
       }
   
       bb14: {
--         StorageDead(_43);
+          StorageDead(_43);
           StorageDead(_42);
           StorageLive(_44);
           StorageLive(_45);
--         StorageLive(_46);
+          StorageLive(_46);
 -         _46 = _2;
 -         _45 = move _46 as i8 (IntToInt);
--         StorageDead(_46);
-+         _45 = const 1_u64 as i8 (IntToInt);
-          _44 = opaque::<i8>(move _45) -> [return: bb15, unwind continue];
++         _46 = const 1_u64;
++         _45 = const 1_i8;
+          StorageDead(_46);
+-         _44 = opaque::<i8>(move _45) -> [return: bb15, unwind continue];
++         _44 = opaque::<i8>(const 1_i8) -> [return: bb15, unwind continue];
       }
   
       bb15: {
@@ -301,12 +332,14 @@
           StorageDead(_44);
           StorageLive(_47);
           StorageLive(_48);
--         StorageLive(_49);
+          StorageLive(_49);
 -         _49 = _2;
 -         _48 = move _49 as i16 (IntToInt);
--         StorageDead(_49);
-+         _48 = const 1_u64 as i16 (IntToInt);
-          _47 = opaque::<i16>(move _48) -> [return: bb16, unwind continue];
++         _49 = const 1_u64;
++         _48 = const 1_i16;
+          StorageDead(_49);
+-         _47 = opaque::<i16>(move _48) -> [return: bb16, unwind continue];
++         _47 = opaque::<i16>(const 1_i16) -> [return: bb16, unwind continue];
       }
   
       bb16: {
@@ -314,12 +347,14 @@
           StorageDead(_47);
           StorageLive(_50);
           StorageLive(_51);
--         StorageLive(_52);
+          StorageLive(_52);
 -         _52 = _2;
 -         _51 = move _52 as i32 (IntToInt);
--         StorageDead(_52);
-+         _51 = const 1_u64 as i32 (IntToInt);
-          _50 = opaque::<i32>(move _51) -> [return: bb17, unwind continue];
++         _52 = const 1_u64;
++         _51 = const 1_i32;
+          StorageDead(_52);
+-         _50 = opaque::<i32>(move _51) -> [return: bb17, unwind continue];
++         _50 = opaque::<i32>(const 1_i32) -> [return: bb17, unwind continue];
       }
   
       bb17: {
@@ -327,12 +362,14 @@
           StorageDead(_50);
           StorageLive(_53);
           StorageLive(_54);
--         StorageLive(_55);
+          StorageLive(_55);
 -         _55 = _2;
 -         _54 = move _55 as i64 (IntToInt);
--         StorageDead(_55);
-+         _54 = const 1_u64 as i64 (IntToInt);
-          _53 = opaque::<i64>(move _54) -> [return: bb18, unwind continue];
++         _55 = const 1_u64;
++         _54 = const 1_i64;
+          StorageDead(_55);
+-         _53 = opaque::<i64>(move _54) -> [return: bb18, unwind continue];
++         _53 = opaque::<i64>(const 1_i64) -> [return: bb18, unwind continue];
       }
   
       bb18: {
@@ -340,12 +377,14 @@
           StorageDead(_53);
           StorageLive(_56);
           StorageLive(_57);
--         StorageLive(_58);
+          StorageLive(_58);
 -         _58 = _2;
 -         _57 = move _58 as f32 (IntToFloat);
--         StorageDead(_58);
-+         _57 = const 1_u64 as f32 (IntToFloat);
-          _56 = opaque::<f32>(move _57) -> [return: bb19, unwind continue];
++         _58 = const 1_u64;
++         _57 = const 1f32;
+          StorageDead(_58);
+-         _56 = opaque::<f32>(move _57) -> [return: bb19, unwind continue];
++         _56 = opaque::<f32>(const 1f32) -> [return: bb19, unwind continue];
       }
   
       bb19: {
@@ -353,12 +392,14 @@
           StorageDead(_56);
           StorageLive(_59);
           StorageLive(_60);
--         StorageLive(_61);
+          StorageLive(_61);
 -         _61 = _2;
 -         _60 = move _61 as f64 (IntToFloat);
--         StorageDead(_61);
-+         _60 = const 1_u64 as f64 (IntToFloat);
-          _59 = opaque::<f64>(move _60) -> [return: bb20, unwind continue];
++         _61 = const 1_u64;
++         _60 = const 1f64;
+          StorageDead(_61);
+-         _59 = opaque::<f64>(move _60) -> [return: bb20, unwind continue];
++         _59 = opaque::<f64>(const 1f64) -> [return: bb20, unwind continue];
       }
   
       bb20: {
@@ -366,12 +407,14 @@
           StorageDead(_59);
           StorageLive(_62);
           StorageLive(_63);
--         StorageLive(_64);
+          StorageLive(_64);
 -         _64 = _3;
 -         _63 = move _64 as u8 (FloatToInt);
--         StorageDead(_64);
-+         _63 = const 1f64 as u8 (FloatToInt);
-          _62 = opaque::<u8>(move _63) -> [return: bb21, unwind continue];
++         _64 = const 1f64;
++         _63 = const 1_u8;
+          StorageDead(_64);
+-         _62 = opaque::<u8>(move _63) -> [return: bb21, unwind continue];
++         _62 = opaque::<u8>(const 1_u8) -> [return: bb21, unwind continue];
       }
   
       bb21: {
@@ -379,12 +422,14 @@
           StorageDead(_62);
           StorageLive(_65);
           StorageLive(_66);
--         StorageLive(_67);
+          StorageLive(_67);
 -         _67 = _3;
 -         _66 = move _67 as u16 (FloatToInt);
--         StorageDead(_67);
-+         _66 = const 1f64 as u16 (FloatToInt);
-          _65 = opaque::<u16>(move _66) -> [return: bb22, unwind continue];
++         _67 = const 1f64;
++         _66 = const 1_u16;
+          StorageDead(_67);
+-         _65 = opaque::<u16>(move _66) -> [return: bb22, unwind continue];
++         _65 = opaque::<u16>(const 1_u16) -> [return: bb22, unwind continue];
       }
   
       bb22: {
@@ -392,12 +437,14 @@
           StorageDead(_65);
           StorageLive(_68);
           StorageLive(_69);
--         StorageLive(_70);
+          StorageLive(_70);
 -         _70 = _3;
 -         _69 = move _70 as u32 (FloatToInt);
--         StorageDead(_70);
-+         _69 = const 1f64 as u32 (FloatToInt);
-          _68 = opaque::<u32>(move _69) -> [return: bb23, unwind continue];
++         _70 = const 1f64;
++         _69 = const 1_u32;
+          StorageDead(_70);
+-         _68 = opaque::<u32>(move _69) -> [return: bb23, unwind continue];
++         _68 = opaque::<u32>(const 1_u32) -> [return: bb23, unwind continue];
       }
   
       bb23: {
@@ -405,12 +452,14 @@
           StorageDead(_68);
           StorageLive(_71);
           StorageLive(_72);
--         StorageLive(_73);
+          StorageLive(_73);
 -         _73 = _3;
 -         _72 = move _73 as u64 (FloatToInt);
--         StorageDead(_73);
-+         _72 = const 1f64 as u64 (FloatToInt);
-          _71 = opaque::<u64>(move _72) -> [return: bb24, unwind continue];
++         _73 = const 1f64;
++         _72 = const 1_u64;
+          StorageDead(_73);
+-         _71 = opaque::<u64>(move _72) -> [return: bb24, unwind continue];
++         _71 = opaque::<u64>(const 1_u64) -> [return: bb24, unwind continue];
       }
   
       bb24: {
@@ -418,12 +467,14 @@
           StorageDead(_71);
           StorageLive(_74);
           StorageLive(_75);
--         StorageLive(_76);
+          StorageLive(_76);
 -         _76 = _3;
 -         _75 = move _76 as i8 (FloatToInt);
--         StorageDead(_76);
-+         _75 = const 1f64 as i8 (FloatToInt);
-          _74 = opaque::<i8>(move _75) -> [return: bb25, unwind continue];
++         _76 = const 1f64;
++         _75 = const 1_i8;
+          StorageDead(_76);
+-         _74 = opaque::<i8>(move _75) -> [return: bb25, unwind continue];
++         _74 = opaque::<i8>(const 1_i8) -> [return: bb25, unwind continue];
       }
   
       bb25: {
@@ -431,12 +482,14 @@
           StorageDead(_74);
           StorageLive(_77);
           StorageLive(_78);
--         StorageLive(_79);
+          StorageLive(_79);
 -         _79 = _3;
 -         _78 = move _79 as i16 (FloatToInt);
--         StorageDead(_79);
-+         _78 = const 1f64 as i16 (FloatToInt);
-          _77 = opaque::<i16>(move _78) -> [return: bb26, unwind continue];
++         _79 = const 1f64;
++         _78 = const 1_i16;
+          StorageDead(_79);
+-         _77 = opaque::<i16>(move _78) -> [return: bb26, unwind continue];
++         _77 = opaque::<i16>(const 1_i16) -> [return: bb26, unwind continue];
       }
   
       bb26: {
@@ -444,12 +497,14 @@
           StorageDead(_77);
           StorageLive(_80);
           StorageLive(_81);
--         StorageLive(_82);
+          StorageLive(_82);
 -         _82 = _3;
 -         _81 = move _82 as i32 (FloatToInt);
--         StorageDead(_82);
-+         _81 = const 1f64 as i32 (FloatToInt);
-          _80 = opaque::<i32>(move _81) -> [return: bb27, unwind continue];
++         _82 = const 1f64;
++         _81 = const 1_i32;
+          StorageDead(_82);
+-         _80 = opaque::<i32>(move _81) -> [return: bb27, unwind continue];
++         _80 = opaque::<i32>(const 1_i32) -> [return: bb27, unwind continue];
       }
   
       bb27: {
@@ -457,12 +512,14 @@
           StorageDead(_80);
           StorageLive(_83);
           StorageLive(_84);
--         StorageLive(_85);
+          StorageLive(_85);
 -         _85 = _3;
 -         _84 = move _85 as i64 (FloatToInt);
--         StorageDead(_85);
-+         _84 = const 1f64 as i64 (FloatToInt);
-          _83 = opaque::<i64>(move _84) -> [return: bb28, unwind continue];
++         _85 = const 1f64;
++         _84 = const 1_i64;
+          StorageDead(_85);
+-         _83 = opaque::<i64>(move _84) -> [return: bb28, unwind continue];
++         _83 = opaque::<i64>(const 1_i64) -> [return: bb28, unwind continue];
       }
   
       bb28: {
@@ -470,31 +527,37 @@
           StorageDead(_83);
           StorageLive(_86);
           StorageLive(_87);
--         StorageLive(_88);
+          StorageLive(_88);
 -         _88 = _3;
 -         _87 = move _88 as f32 (FloatToFloat);
--         StorageDead(_88);
-+         _87 = const 1f64 as f32 (FloatToFloat);
-          _86 = opaque::<f32>(move _87) -> [return: bb29, unwind continue];
++         _88 = const 1f64;
++         _87 = const 1f32;
+          StorageDead(_88);
+-         _86 = opaque::<f32>(move _87) -> [return: bb29, unwind continue];
++         _86 = opaque::<f32>(const 1f32) -> [return: bb29, unwind continue];
       }
   
       bb29: {
           StorageDead(_87);
           StorageDead(_86);
           StorageLive(_89);
--         StorageLive(_90);
+          StorageLive(_90);
 -         _90 = _3;
 -         _89 = opaque::<f64>(move _90) -> [return: bb30, unwind continue];
++         _90 = const 1f64;
 +         _89 = opaque::<f64>(const 1f64) -> [return: bb30, unwind continue];
       }
   
       bb30: {
--         StorageDead(_90);
+          StorageDead(_90);
           StorageDead(_89);
           _0 = const ();
 -         StorageDead(_3);
 -         StorageDead(_2);
 -         StorageDead(_1);
++         nop;
++         nop;
++         nop;
           return;
       }
   }

tests/mir-opt/gvn.comparison.GVN.panic-abort.diff

@@ -0,0 +1,94 @@
+- // MIR for `comparison` before GVN
++ // MIR for `comparison` after GVN
+  
+  fn comparison(_1: u64, _2: u64) -> () {
+      debug x => _1;
+      debug y => _2;
+      let mut _0: ();
+      let _3: ();
+      let mut _4: bool;
+      let mut _5: u64;
+      let mut _6: u64;
+      let _7: ();
+      let mut _8: bool;
+      let mut _9: u64;
+      let mut _10: u64;
+      let _11: ();
+      let mut _12: bool;
+      let mut _13: u64;
+      let mut _14: u64;
+      let _15: ();
+      let mut _16: bool;
+      let mut _17: u64;
+      let mut _18: u64;
+  
+      bb0: {
+          StorageLive(_3);
+          StorageLive(_4);
+          StorageLive(_5);
+          _5 = _1;
+          StorageLive(_6);
+          _6 = _1;
+-         _4 = Eq(move _5, move _6);
++         _4 = Eq(_1, _1);
+          StorageDead(_6);
+          StorageDead(_5);
+          _3 = opaque::<bool>(move _4) -> [return: bb1, unwind unreachable];
+      }
+  
+      bb1: {
+          StorageDead(_4);
+          StorageDead(_3);
+          StorageLive(_7);
+          StorageLive(_8);
+          StorageLive(_9);
+          _9 = _1;
+          StorageLive(_10);
+          _10 = _1;
+-         _8 = Ne(move _9, move _10);
++         _8 = Ne(_1, _1);
+          StorageDead(_10);
+          StorageDead(_9);
+          _7 = opaque::<bool>(move _8) -> [return: bb2, unwind unreachable];
+      }
+  
+      bb2: {
+          StorageDead(_8);
+          StorageDead(_7);
+          StorageLive(_11);
+          StorageLive(_12);
+          StorageLive(_13);
+          _13 = _1;
+          StorageLive(_14);
+          _14 = _2;
+-         _12 = Eq(move _13, move _14);
++         _12 = Eq(_1, _2);
+          StorageDead(_14);
+          StorageDead(_13);
+          _11 = opaque::<bool>(move _12) -> [return: bb3, unwind unreachable];
+      }
+  
+      bb3: {
+          StorageDead(_12);
+          StorageDead(_11);
+          StorageLive(_15);
+          StorageLive(_16);
+          StorageLive(_17);
+          _17 = _1;
+          StorageLive(_18);
+          _18 = _2;
+-         _16 = Ne(move _17, move _18);
++         _16 = Ne(_1, _2);
+          StorageDead(_18);
+          StorageDead(_17);
+          _15 = opaque::<bool>(move _16) -> [return: bb4, unwind unreachable];
+      }
+  
+      bb4: {
+          StorageDead(_16);
+          StorageDead(_15);
+          _0 = const ();
+          return;
+      }
+  }
+  

tests/mir-opt/gvn.comparison.GVN.panic-unwind.diff

@@ -0,0 +1,94 @@
+- // MIR for `comparison` before GVN
++ // MIR for `comparison` after GVN
+  
+  fn comparison(_1: u64, _2: u64) -> () {
+      debug x => _1;
+      debug y => _2;
+      let mut _0: ();
+      let _3: ();
+      let mut _4: bool;
+      let mut _5: u64;
+      let mut _6: u64;
+      let _7: ();
+      let mut _8: bool;
+      let mut _9: u64;
+      let mut _10: u64;
+      let _11: ();
+      let mut _12: bool;
+      let mut _13: u64;
+      let mut _14: u64;
+      let _15: ();
+      let mut _16: bool;
+      let mut _17: u64;
+      let mut _18: u64;
+  
+      bb0: {
+          StorageLive(_3);
+          StorageLive(_4);
+          StorageLive(_5);
+          _5 = _1;
+          StorageLive(_6);
+          _6 = _1;
+-         _4 = Eq(move _5, move _6);
++         _4 = Eq(_1, _1);
+          StorageDead(_6);
+          StorageDead(_5);
+          _3 = opaque::<bool>(move _4) -> [return: bb1, unwind continue];
+      }
+  
+      bb1: {
+          StorageDead(_4);
+          StorageDead(_3);
+          StorageLive(_7);
+          StorageLive(_8);
+          StorageLive(_9);
+          _9 = _1;
+          StorageLive(_10);
+          _10 = _1;
+-         _8 = Ne(move _9, move _10);
++         _8 = Ne(_1, _1);
+          StorageDead(_10);
+          StorageDead(_9);
+          _7 = opaque::<bool>(move _8) -> [return: bb2, unwind continue];
+      }
+  
+      bb2: {
+          StorageDead(_8);
+          StorageDead(_7);
+          StorageLive(_11);
+          StorageLive(_12);
+          StorageLive(_13);
+          _13 = _1;
+          StorageLive(_14);
+          _14 = _2;
+-         _12 = Eq(move _13, move _14);
++         _12 = Eq(_1, _2);
+          StorageDead(_14);
+          StorageDead(_13);
+          _11 = opaque::<bool>(move _12) -> [return: bb3, unwind continue];
+      }
+  
+      bb3: {
+          StorageDead(_12);
+          StorageDead(_11);
+          StorageLive(_15);
+          StorageLive(_16);
+          StorageLive(_17);
+          _17 = _1;
+          StorageLive(_18);
+          _18 = _2;
+-         _16 = Ne(move _17, move _18);
++         _16 = Ne(_1, _2);
+          StorageDead(_18);
+          StorageDead(_17);
+          _15 = opaque::<bool>(move _16) -> [return: bb4, unwind continue];
+      }
+  
+      bb4: {
+          StorageDead(_16);
+          StorageDead(_15);
+          _0 = const ();
+          return;
+      }
+  }
+  

tests/mir-opt/gvn.dereferences.GVN.panic-abort.diff

@@ -72,7 +72,8 @@
       bb2: {
           StorageDead(_7);
           StorageDead(_6);
-          StorageLive(_8);
+-         StorageLive(_8);
++         nop;
           _8 = &raw const (*_1);
           StorageLive(_9);
           StorageLive(_10);
@@ -92,7 +93,8 @@
       bb4: {
           StorageDead(_12);
           StorageDead(_11);
-          StorageLive(_13);
+-         StorageLive(_13);
++         nop;
           _13 = &raw mut (*_1);
           StorageLive(_14);
           StorageLive(_15);
@@ -112,10 +114,12 @@
       bb6: {
           StorageDead(_17);
           StorageDead(_16);
-          StorageLive(_18);
+-         StorageLive(_18);
++         nop;
           _18 = &(*_1);
           StorageLive(_19);
 -         StorageLive(_20);
++         nop;
           _20 = (*_18);
 -         _19 = opaque::<u32>(move _20) -> [return: bb7, unwind unreachable];
 +         _19 = opaque::<u32>(_20) -> [return: bb7, unwind unreachable];
@@ -123,16 +127,18 @@
   
       bb7: {
 -         StorageDead(_20);
++         nop;
           StorageDead(_19);
           StorageLive(_21);
--         StorageLive(_22);
+          StorageLive(_22);
 -         _22 = (*_18);
 -         _21 = opaque::<u32>(move _22) -> [return: bb8, unwind unreachable];
++         _22 = _20;
 +         _21 = opaque::<u32>(_20) -> [return: bb8, unwind unreachable];
       }
   
       bb8: {
--         StorageDead(_22);
+          StorageDead(_22);
           StorageDead(_21);
           StorageLive(_23);
           StorageLive(_24);
@@ -163,6 +169,7 @@
           StorageDead(_27);
           StorageLive(_29);
 -         StorageLive(_30);
++         nop;
           _30 = ((*_3).0: u32);
 -         _29 = opaque::<u32>(move _30) -> [return: bb12, unwind unreachable];
 +         _29 = opaque::<u32>(_30) -> [return: bb12, unwind unreachable];
@@ -170,21 +177,26 @@
   
       bb12: {
 -         StorageDead(_30);
++         nop;
           StorageDead(_29);
           StorageLive(_31);
--         StorageLive(_32);
+          StorageLive(_32);
 -         _32 = ((*_3).0: u32);
 -         _31 = opaque::<u32>(move _32) -> [return: bb13, unwind unreachable];
++         _32 = _30;
 +         _31 = opaque::<u32>(_30) -> [return: bb13, unwind unreachable];
       }
   
       bb13: {
--         StorageDead(_32);
+          StorageDead(_32);
           StorageDead(_31);
           _0 = const ();
-          StorageDead(_18);
-          StorageDead(_13);
-          StorageDead(_8);
+-         StorageDead(_18);
+-         StorageDead(_13);
+-         StorageDead(_8);
++         nop;
++         nop;
++         nop;
           return;
       }
   }

tests/mir-opt/gvn.dereferences.GVN.panic-unwind.diff

@@ -72,7 +72,8 @@
       bb2: {
           StorageDead(_7);
           StorageDead(_6);
-          StorageLive(_8);
+-         StorageLive(_8);
++         nop;
           _8 = &raw const (*_1);
           StorageLive(_9);
           StorageLive(_10);
@@ -92,7 +93,8 @@
       bb4: {
           StorageDead(_12);
           StorageDead(_11);
-          StorageLive(_13);
+-         StorageLive(_13);
++         nop;
           _13 = &raw mut (*_1);
           StorageLive(_14);
           StorageLive(_15);
@@ -112,10 +114,12 @@
       bb6: {
           StorageDead(_17);
           StorageDead(_16);
-          StorageLive(_18);
+-         StorageLive(_18);
++         nop;
           _18 = &(*_1);
           StorageLive(_19);
 -         StorageLive(_20);
++         nop;
           _20 = (*_18);
 -         _19 = opaque::<u32>(move _20) -> [return: bb7, unwind continue];
 +         _19 = opaque::<u32>(_20) -> [return: bb7, unwind continue];
@@ -123,16 +127,18 @@
   
       bb7: {
 -         StorageDead(_20);
++         nop;
           StorageDead(_19);
           StorageLive(_21);
--         StorageLive(_22);
+          StorageLive(_22);
 -         _22 = (*_18);
 -         _21 = opaque::<u32>(move _22) -> [return: bb8, unwind continue];
++         _22 = _20;
 +         _21 = opaque::<u32>(_20) -> [return: bb8, unwind continue];
       }
   
       bb8: {
--         StorageDead(_22);
+          StorageDead(_22);
           StorageDead(_21);
           StorageLive(_23);
           StorageLive(_24);
@@ -163,6 +169,7 @@
           StorageDead(_27);
           StorageLive(_29);
 -         StorageLive(_30);
++         nop;
           _30 = ((*_3).0: u32);
 -         _29 = opaque::<u32>(move _30) -> [return: bb12, unwind continue];
 +         _29 = opaque::<u32>(_30) -> [return: bb12, unwind continue];
@@ -170,21 +177,26 @@
   
       bb12: {
 -         StorageDead(_30);
++         nop;
           StorageDead(_29);
           StorageLive(_31);
--         StorageLive(_32);
+          StorageLive(_32);
 -         _32 = ((*_3).0: u32);
 -         _31 = opaque::<u32>(move _32) -> [return: bb13, unwind continue];
++         _32 = _30;
 +         _31 = opaque::<u32>(_30) -> [return: bb13, unwind continue];
       }
   
       bb13: {
--         StorageDead(_32);
+          StorageDead(_32);
           StorageDead(_31);
           _0 = const ();
-          StorageDead(_18);
-          StorageDead(_13);
-          StorageDead(_8);
+-         StorageDead(_18);
+-         StorageDead(_13);
+-         StorageDead(_8);
++         nop;
++         nop;
++         nop;
           return;
       }
   }

tests/mir-opt/gvn.duplicate_slice.GVN.panic-abort.diff

@@ -0,0 +1,38 @@
+- // MIR for `duplicate_slice` before GVN
++ // MIR for `duplicate_slice` after GVN
+  
+  fn duplicate_slice() -> (bool, bool) {
+      let mut _0: (bool, bool);
+      let mut _1: u128;
+      let mut _2: u128;
+      let mut _3: u128;
+      let mut _4: u128;
+      let mut _5: &str;
+      let mut _6: &str;
+      let mut _7: (&str,);
+      let mut _8: &str;
+      let mut _9: bool;
+      let mut _10: bool;
+  
+      bb0: {
+          _7 = (const "a",);
+          _1 = (_7.0: &str) as u128 (Transmute);
+          _5 = identity::<&str>((_7.0: &str)) -> [return: bb1, unwind unreachable];
+      }
+  
+      bb1: {
+          _3 = _5 as u128 (Transmute);
+          _8 = const "a";
+          _2 = _8 as u128 (Transmute);
+          _6 = identity::<&str>(_8) -> [return: bb2, unwind unreachable];
+      }
+  
+      bb2: {
+          _4 = _6 as u128 (Transmute);
+          _9 = Eq(_1, _2);
+          _10 = Eq(_3, _4);
+          _0 = (_9, _10);
+          return;
+      }
+  }
+  

tests/mir-opt/gvn.duplicate_slice.GVN.panic-unwind.diff

@@ -0,0 +1,38 @@
+- // MIR for `duplicate_slice` before GVN
++ // MIR for `duplicate_slice` after GVN
+  
+  fn duplicate_slice() -> (bool, bool) {
+      let mut _0: (bool, bool);
+      let mut _1: u128;
+      let mut _2: u128;
+      let mut _3: u128;
+      let mut _4: u128;
+      let mut _5: &str;
+      let mut _6: &str;
+      let mut _7: (&str,);
+      let mut _8: &str;
+      let mut _9: bool;
+      let mut _10: bool;
+  
+      bb0: {
+          _7 = (const "a",);
+          _1 = (_7.0: &str) as u128 (Transmute);
+          _5 = identity::<&str>((_7.0: &str)) -> [return: bb1, unwind continue];
+      }
+  
+      bb1: {
+          _3 = _5 as u128 (Transmute);
+          _8 = const "a";
+          _2 = _8 as u128 (Transmute);
+          _6 = identity::<&str>(_8) -> [return: bb2, unwind continue];
+      }
+  
+      bb2: {
+          _4 = _6 as u128 (Transmute);
+          _9 = Eq(_1, _2);
+          _10 = Eq(_3, _4);
+          _0 = (_9, _10);
+          return;
+      }
+  }
+  

tests/mir-opt/gvn.fn_pointers.GVN.panic-abort.diff

@@ -0,0 +1,118 @@
+- // MIR for `fn_pointers` before GVN
++ // MIR for `fn_pointers` after GVN
+  
+  fn fn_pointers() -> () {
+      let mut _0: ();
+      let _1: fn(u8) -> u8;
+      let _2: ();
+      let mut _3: fn(u8) -> u8;
+      let _5: ();
+      let mut _6: fn(u8) -> u8;
+      let mut _9: {closure@$DIR/gvn.rs:591:19: 591:21};
+      let _10: ();
+      let mut _11: fn();
+      let mut _13: {closure@$DIR/gvn.rs:591:19: 591:21};
+      let _14: ();
+      let mut _15: fn();
+      scope 1 {
+          debug f => _1;
+          let _4: fn(u8) -> u8;
+          scope 2 {
+              debug g => _4;
+              let _7: {closure@$DIR/gvn.rs:591:19: 591:21};
+              scope 3 {
+                  debug closure => _7;
+                  let _8: fn();
+                  scope 4 {
+                      debug cf => _8;
+                      let _12: fn();
+                      scope 5 {
+                          debug cg => _12;
+                      }
+                  }
+              }
+          }
+      }
+  
+      bb0: {
+-         StorageLive(_1);
++         nop;
+          _1 = identity::<u8> as fn(u8) -> u8 (PointerCoercion(ReifyFnPointer));
+          StorageLive(_2);
+          StorageLive(_3);
+          _3 = _1;
+-         _2 = opaque::<fn(u8) -> u8>(move _3) -> [return: bb1, unwind unreachable];
++         _2 = opaque::<fn(u8) -> u8>(_1) -> [return: bb1, unwind unreachable];
+      }
+  
+      bb1: {
+          StorageDead(_3);
+          StorageDead(_2);
+-         StorageLive(_4);
++         nop;
+          _4 = identity::<u8> as fn(u8) -> u8 (PointerCoercion(ReifyFnPointer));
+          StorageLive(_5);
+          StorageLive(_6);
+          _6 = _4;
+-         _5 = opaque::<fn(u8) -> u8>(move _6) -> [return: bb2, unwind unreachable];
++         _5 = opaque::<fn(u8) -> u8>(_4) -> [return: bb2, unwind unreachable];
+      }
+  
+      bb2: {
+          StorageDead(_6);
+          StorageDead(_5);
+-         StorageLive(_7);
+-         _7 = {closure@$DIR/gvn.rs:591:19: 591:21};
+-         StorageLive(_8);
++         nop;
++         _7 = const ZeroSized: {closure@$DIR/gvn.rs:591:19: 591:21};
++         nop;
+          StorageLive(_9);
+-         _9 = _7;
+-         _8 = move _9 as fn() (PointerCoercion(ClosureFnPointer(Normal)));
++         _9 = const ZeroSized: {closure@$DIR/gvn.rs:591:19: 591:21};
++         _8 = const ZeroSized: {closure@$DIR/gvn.rs:591:19: 591:21} as fn() (PointerCoercion(ClosureFnPointer(Normal)));
+          StorageDead(_9);
+          StorageLive(_10);
+          StorageLive(_11);
+          _11 = _8;
+-         _10 = opaque::<fn()>(move _11) -> [return: bb3, unwind unreachable];
++         _10 = opaque::<fn()>(_8) -> [return: bb3, unwind unreachable];
+      }
+  
+      bb3: {
+          StorageDead(_11);
+          StorageDead(_10);
+-         StorageLive(_12);
++         nop;
+          StorageLive(_13);
+-         _13 = _7;
+-         _12 = move _13 as fn() (PointerCoercion(ClosureFnPointer(Normal)));
++         _13 = const ZeroSized: {closure@$DIR/gvn.rs:591:19: 591:21};
++         _12 = const ZeroSized: {closure@$DIR/gvn.rs:591:19: 591:21} as fn() (PointerCoercion(ClosureFnPointer(Normal)));
+          StorageDead(_13);
+          StorageLive(_14);
+          StorageLive(_15);
+          _15 = _12;
+-         _14 = opaque::<fn()>(move _15) -> [return: bb4, unwind unreachable];
++         _14 = opaque::<fn()>(_12) -> [return: bb4, unwind unreachable];
+      }
+  
+      bb4: {
+          StorageDead(_15);
+          StorageDead(_14);
+          _0 = const ();
+-         StorageDead(_12);
+-         StorageDead(_8);
+-         StorageDead(_7);
+-         StorageDead(_4);
+-         StorageDead(_1);
++         nop;
++         nop;
++         nop;
++         nop;
++         nop;
+          return;
+      }
+  }
+  

tests/mir-opt/gvn.fn_pointers.GVN.panic-unwind.diff

@@ -0,0 +1,118 @@
+- // MIR for `fn_pointers` before GVN
++ // MIR for `fn_pointers` after GVN
+  
+  fn fn_pointers() -> () {
+      let mut _0: ();
+      let _1: fn(u8) -> u8;
+      let _2: ();
+      let mut _3: fn(u8) -> u8;
+      let _5: ();
+      let mut _6: fn(u8) -> u8;
+      let mut _9: {closure@$DIR/gvn.rs:591:19: 591:21};
+      let _10: ();
+      let mut _11: fn();
+      let mut _13: {closure@$DIR/gvn.rs:591:19: 591:21};
+      let _14: ();
+      let mut _15: fn();
+      scope 1 {
+          debug f => _1;
+          let _4: fn(u8) -> u8;
+          scope 2 {
+              debug g => _4;
+              let _7: {closure@$DIR/gvn.rs:591:19: 591:21};
+              scope 3 {
+                  debug closure => _7;
+                  let _8: fn();
+                  scope 4 {
+                      debug cf => _8;
+                      let _12: fn();
+                      scope 5 {
+                          debug cg => _12;
+                      }
+                  }
+              }
+          }
+      }
+  
+      bb0: {
+-         StorageLive(_1);
++         nop;
+          _1 = identity::<u8> as fn(u8) -> u8 (PointerCoercion(ReifyFnPointer));
+          StorageLive(_2);
+          StorageLive(_3);
+          _3 = _1;
+-         _2 = opaque::<fn(u8) -> u8>(move _3) -> [return: bb1, unwind continue];
++         _2 = opaque::<fn(u8) -> u8>(_1) -> [return: bb1, unwind continue];
+      }
+  
+      bb1: {
+          StorageDead(_3);
+          StorageDead(_2);
+-         StorageLive(_4);
++         nop;
+          _4 = identity::<u8> as fn(u8) -> u8 (PointerCoercion(ReifyFnPointer));
+          StorageLive(_5);
+          StorageLive(_6);
+          _6 = _4;
+-         _5 = opaque::<fn(u8) -> u8>(move _6) -> [return: bb2, unwind continue];
++         _5 = opaque::<fn(u8) -> u8>(_4) -> [return: bb2, unwind continue];
+      }
+  
+      bb2: {
+          StorageDead(_6);
+          StorageDead(_5);
+-         StorageLive(_7);
+-         _7 = {closure@$DIR/gvn.rs:591:19: 591:21};
+-         StorageLive(_8);
++         nop;
++         _7 = const ZeroSized: {closure@$DIR/gvn.rs:591:19: 591:21};
++         nop;
+          StorageLive(_9);
+-         _9 = _7;
+-         _8 = move _9 as fn() (PointerCoercion(ClosureFnPointer(Normal)));
++         _9 = const ZeroSized: {closure@$DIR/gvn.rs:591:19: 591:21};
++         _8 = const ZeroSized: {closure@$DIR/gvn.rs:591:19: 591:21} as fn() (PointerCoercion(ClosureFnPointer(Normal)));
+          StorageDead(_9);
+          StorageLive(_10);
+          StorageLive(_11);
+          _11 = _8;
+-         _10 = opaque::<fn()>(move _11) -> [return: bb3, unwind continue];
++         _10 = opaque::<fn()>(_8) -> [return: bb3, unwind continue];
+      }
+  
+      bb3: {
+          StorageDead(_11);
+          StorageDead(_10);
+-         StorageLive(_12);
++         nop;
+          StorageLive(_13);
+-         _13 = _7;
+-         _12 = move _13 as fn() (PointerCoercion(ClosureFnPointer(Normal)));
++         _13 = const ZeroSized: {closure@$DIR/gvn.rs:591:19: 591:21};
++         _12 = const ZeroSized: {closure@$DIR/gvn.rs:591:19: 591:21} as fn() (PointerCoercion(ClosureFnPointer(Normal)));
+          StorageDead(_13);
+          StorageLive(_14);
+          StorageLive(_15);
+          _15 = _12;
+-         _14 = opaque::<fn()>(move _15) -> [return: bb4, unwind continue];
++         _14 = opaque::<fn()>(_12) -> [return: bb4, unwind continue];
+      }
+  
+      bb4: {
+          StorageDead(_15);
+          StorageDead(_14);
+          _0 = const ();
+-         StorageDead(_12);
+-         StorageDead(_8);
+-         StorageDead(_7);
+-         StorageDead(_4);
+-         StorageDead(_1);
++         nop;
++         nop;
++         nop;
++         nop;
++         nop;
+          return;
+      }
+  }
+  

tests/mir-opt/gvn.indirect_static.GVN.panic-abort.diff

@@ -0,0 +1,19 @@
+- // MIR for `indirect_static` before GVN
++ // MIR for `indirect_static` after GVN
+  
+  fn indirect_static() -> () {
+      let mut _0: ();
+      let mut _1: &std::option::Option<u8>;
+      let mut _2: u8;
+  
+      bb0: {
+          _1 = const {ALLOC0: &Option<u8>};
+          _2 = (((*_1) as variant#1).0: u8);
+          return;
+      }
+  }
+  
+  ALLOC0 (static: A, size: 2, align: 1) {
+      00 __                                           │ .░
+  }
+  

tests/mir-opt/gvn.indirect_static.GVN.panic-unwind.diff

@@ -0,0 +1,19 @@
+- // MIR for `indirect_static` before GVN
++ // MIR for `indirect_static` after GVN
+  
+  fn indirect_static() -> () {
+      let mut _0: ();
+      let mut _1: &std::option::Option<u8>;
+      let mut _2: u8;
+  
+      bb0: {
+          _1 = const {ALLOC0: &Option<u8>};
+          _2 = (((*_1) as variant#1).0: u8);
+          return;
+      }
+  }
+  
+  ALLOC0 (static: A, size: 2, align: 1) {
+      00 __                                           │ .░
+  }
+  

tests/mir-opt/gvn.multiple_branches.GVN.panic-abort.diff

@@ -39,9 +39,9 @@
       let mut _34: u8;
   
       bb0: {
--         StorageLive(_4);
--         StorageLive(_5);
--         _5 = _1;
+          StorageLive(_4);
+          StorageLive(_5);
+          _5 = _1;
 -         switchInt(move _5) -> [0: bb4, otherwise: bb1];
 +         switchInt(_1) -> [0: bb4, otherwise: bb1];
       }
@@ -49,121 +49,130 @@
       bb1: {
           StorageLive(_6);
 -         StorageLive(_7);
--         StorageLive(_8);
--         _8 = _2;
--         StorageLive(_9);
--         _9 = _3;
++         nop;
+          StorageLive(_8);
+          _8 = _2;
+          StorageLive(_9);
+          _9 = _3;
 -         _7 = Add(move _8, move _9);
--         StorageDead(_9);
--         StorageDead(_8);
--         _6 = opaque::<u8>(move _7) -> [return: bb2, unwind unreachable];
 +         _7 = Add(_2, _3);
+          StorageDead(_9);
+          StorageDead(_8);
+-         _6 = opaque::<u8>(move _7) -> [return: bb2, unwind unreachable];
 +         _6 = opaque::<u8>(_7) -> [return: bb2, unwind unreachable];
       }
   
       bb2: {
 -         StorageDead(_7);
++         nop;
           StorageDead(_6);
           StorageLive(_10);
--         StorageLive(_11);
--         StorageLive(_12);
--         _12 = _2;
--         StorageLive(_13);
--         _13 = _3;
+          StorageLive(_11);
+          StorageLive(_12);
+          _12 = _2;
+          StorageLive(_13);
+          _13 = _3;
 -         _11 = Add(move _12, move _13);
--         StorageDead(_13);
--         StorageDead(_12);
++         _11 = _7;
+          StorageDead(_13);
+          StorageDead(_12);
 -         _10 = opaque::<u8>(move _11) -> [return: bb3, unwind unreachable];
 +         _10 = opaque::<u8>(_7) -> [return: bb3, unwind unreachable];
       }
   
       bb3: {
--         StorageDead(_11);
+          StorageDead(_11);
           StorageDead(_10);
--         _4 = const ();
+          _4 = const ();
           goto -> bb7;
       }
   
       bb4: {
           StorageLive(_14);
 -         StorageLive(_15);
--         StorageLive(_16);
--         _16 = _2;
--         StorageLive(_17);
--         _17 = _3;
++         nop;
+          StorageLive(_16);
+          _16 = _2;
+          StorageLive(_17);
+          _17 = _3;
 -         _15 = Add(move _16, move _17);
--         StorageDead(_17);
--         StorageDead(_16);
--         _14 = opaque::<u8>(move _15) -> [return: bb5, unwind unreachable];
 +         _15 = Add(_2, _3);
+          StorageDead(_17);
+          StorageDead(_16);
+-         _14 = opaque::<u8>(move _15) -> [return: bb5, unwind unreachable];
 +         _14 = opaque::<u8>(_15) -> [return: bb5, unwind unreachable];
       }
   
       bb5: {
 -         StorageDead(_15);
++         nop;
           StorageDead(_14);
           StorageLive(_18);
--         StorageLive(_19);
--         StorageLive(_20);
--         _20 = _2;
--         StorageLive(_21);
--         _21 = _3;
+          StorageLive(_19);
+          StorageLive(_20);
+          _20 = _2;
+          StorageLive(_21);
+          _21 = _3;
 -         _19 = Add(move _20, move _21);
--         StorageDead(_21);
--         StorageDead(_20);
++         _19 = _15;
+          StorageDead(_21);
+          StorageDead(_20);
 -         _18 = opaque::<u8>(move _19) -> [return: bb6, unwind unreachable];
 +         _18 = opaque::<u8>(_15) -> [return: bb6, unwind unreachable];
       }
   
       bb6: {
--         StorageDead(_19);
+          StorageDead(_19);
           StorageDead(_18);
--         _4 = const ();
+          _4 = const ();
           goto -> bb7;
       }
   
       bb7: {
--         StorageDead(_5);
--         StorageDead(_4);
+          StorageDead(_5);
+          StorageDead(_4);
           StorageLive(_22);
 -         StorageLive(_23);
--         StorageLive(_24);
--         _24 = _2;
--         StorageLive(_25);
--         _25 = _3;
++         nop;
+          StorageLive(_24);
+          _24 = _2;
+          StorageLive(_25);
+          _25 = _3;
 -         _23 = Add(move _24, move _25);
--         StorageDead(_25);
--         StorageDead(_24);
--         _22 = opaque::<u8>(move _23) -> [return: bb8, unwind unreachable];
 +         _23 = Add(_2, _3);
+          StorageDead(_25);
+          StorageDead(_24);
+-         _22 = opaque::<u8>(move _23) -> [return: bb8, unwind unreachable];
 +         _22 = opaque::<u8>(_23) -> [return: bb8, unwind unreachable];
       }
   
       bb8: {
 -         StorageDead(_23);
++         nop;
           StorageDead(_22);
--         StorageLive(_26);
--         _26 = _1;
+          StorageLive(_26);
+          _26 = _1;
 -         switchInt(move _26) -> [0: bb11, otherwise: bb9];
 +         switchInt(_1) -> [0: bb11, otherwise: bb9];
       }
   
       bb9: {
           StorageLive(_27);
--         StorageLive(_28);
--         StorageLive(_29);
--         _29 = _2;
--         StorageLive(_30);
--         _30 = _3;
+          StorageLive(_28);
+          StorageLive(_29);
+          _29 = _2;
+          StorageLive(_30);
+          _30 = _3;
 -         _28 = Add(move _29, move _30);
--         StorageDead(_30);
--         StorageDead(_29);
++         _28 = _23;
+          StorageDead(_30);
+          StorageDead(_29);
 -         _27 = opaque::<u8>(move _28) -> [return: bb10, unwind unreachable];
 +         _27 = opaque::<u8>(_23) -> [return: bb10, unwind unreachable];
       }
   
       bb10: {
--         StorageDead(_28);
+          StorageDead(_28);
           StorageDead(_27);
           _0 = const ();
           goto -> bb13;
@@ -171,27 +180,28 @@
   
       bb11: {
           StorageLive(_31);
--         StorageLive(_32);
--         StorageLive(_33);
--         _33 = _2;
--         StorageLive(_34);
--         _34 = _3;
+          StorageLive(_32);
+          StorageLive(_33);
+          _33 = _2;
+          StorageLive(_34);
+          _34 = _3;
 -         _32 = Add(move _33, move _34);
--         StorageDead(_34);
--         StorageDead(_33);
++         _32 = _23;
+          StorageDead(_34);
+          StorageDead(_33);
 -         _31 = opaque::<u8>(move _32) -> [return: bb12, unwind unreachable];
 +         _31 = opaque::<u8>(_23) -> [return: bb12, unwind unreachable];
       }
   
       bb12: {
--         StorageDead(_32);
+          StorageDead(_32);
           StorageDead(_31);
           _0 = const ();
           goto -> bb13;
       }
   
       bb13: {
--         StorageDead(_26);
+          StorageDead(_26);
           return;
       }
   }

tests/mir-opt/gvn.multiple_branches.GVN.panic-unwind.diff

@@ -39,9 +39,9 @@
       let mut _34: u8;
   
       bb0: {
--         StorageLive(_4);
--         StorageLive(_5);
--         _5 = _1;
+          StorageLive(_4);
+          StorageLive(_5);
+          _5 = _1;
 -         switchInt(move _5) -> [0: bb4, otherwise: bb1];
 +         switchInt(_1) -> [0: bb4, otherwise: bb1];
       }
@@ -49,121 +49,130 @@
       bb1: {
           StorageLive(_6);
 -         StorageLive(_7);
--         StorageLive(_8);
--         _8 = _2;
--         StorageLive(_9);
--         _9 = _3;
++         nop;
+          StorageLive(_8);
+          _8 = _2;
+          StorageLive(_9);
+          _9 = _3;
 -         _7 = Add(move _8, move _9);
--         StorageDead(_9);
--         StorageDead(_8);
--         _6 = opaque::<u8>(move _7) -> [return: bb2, unwind continue];
 +         _7 = Add(_2, _3);
+          StorageDead(_9);
+          StorageDead(_8);
+-         _6 = opaque::<u8>(move _7) -> [return: bb2, unwind continue];
 +         _6 = opaque::<u8>(_7) -> [return: bb2, unwind continue];
       }
   
       bb2: {
 -         StorageDead(_7);
++         nop;
           StorageDead(_6);
           StorageLive(_10);
--         StorageLive(_11);
--         StorageLive(_12);
--         _12 = _2;
--         StorageLive(_13);
--         _13 = _3;
+          StorageLive(_11);
+          StorageLive(_12);
+          _12 = _2;
+          StorageLive(_13);
+          _13 = _3;
 -         _11 = Add(move _12, move _13);
--         StorageDead(_13);
--         StorageDead(_12);
++         _11 = _7;
+          StorageDead(_13);
+          StorageDead(_12);
 -         _10 = opaque::<u8>(move _11) -> [return: bb3, unwind continue];
 +         _10 = opaque::<u8>(_7) -> [return: bb3, unwind continue];
       }
   
       bb3: {
--         StorageDead(_11);
+          StorageDead(_11);
           StorageDead(_10);
--         _4 = const ();
+          _4 = const ();
           goto -> bb7;
       }
   
       bb4: {
           StorageLive(_14);
 -         StorageLive(_15);
--         StorageLive(_16);
--         _16 = _2;
--         StorageLive(_17);
--         _17 = _3;
++         nop;
+          StorageLive(_16);
+          _16 = _2;
+          StorageLive(_17);
+          _17 = _3;
 -         _15 = Add(move _16, move _17);
--         StorageDead(_17);
--         StorageDead(_16);
--         _14 = opaque::<u8>(move _15) -> [return: bb5, unwind continue];
 +         _15 = Add(_2, _3);
+          StorageDead(_17);
+          StorageDead(_16);
+-         _14 = opaque::<u8>(move _15) -> [return: bb5, unwind continue];
 +         _14 = opaque::<u8>(_15) -> [return: bb5, unwind continue];
       }
   
       bb5: {
 -         StorageDead(_15);
++         nop;
           StorageDead(_14);
           StorageLive(_18);
--         StorageLive(_19);
--         StorageLive(_20);
--         _20 = _2;
--         StorageLive(_21);
--         _21 = _3;
+          StorageLive(_19);
+          StorageLive(_20);
+          _20 = _2;
+          StorageLive(_21);
+          _21 = _3;
 -         _19 = Add(move _20, move _21);
--         StorageDead(_21);
--         StorageDead(_20);
++         _19 = _15;
+          StorageDead(_21);
+          StorageDead(_20);
 -         _18 = opaque::<u8>(move _19) -> [return: bb6, unwind continue];
 +         _18 = opaque::<u8>(_15) -> [return: bb6, unwind continue];
       }
   
       bb6: {
--         StorageDead(_19);
+          StorageDead(_19);
           StorageDead(_18);
--         _4 = const ();
+          _4 = const ();
           goto -> bb7;
       }
   
       bb7: {
--         StorageDead(_5);
--         StorageDead(_4);
+          StorageDead(_5);
+          StorageDead(_4);
           StorageLive(_22);
 -         StorageLive(_23);
--         StorageLive(_24);
--         _24 = _2;
--         StorageLive(_25);
--         _25 = _3;
++         nop;
+          StorageLive(_24);
+          _24 = _2;
+          StorageLive(_25);
+          _25 = _3;
 -         _23 = Add(move _24, move _25);
--         StorageDead(_25);
--         StorageDead(_24);
--         _22 = opaque::<u8>(move _23) -> [return: bb8, unwind continue];
 +         _23 = Add(_2, _3);
+          StorageDead(_25);
+          StorageDead(_24);
+-         _22 = opaque::<u8>(move _23) -> [return: bb8, unwind continue];
 +         _22 = opaque::<u8>(_23) -> [return: bb8, unwind continue];
       }
   
       bb8: {
 -         StorageDead(_23);
++         nop;
           StorageDead(_22);
--         StorageLive(_26);
--         _26 = _1;
+          StorageLive(_26);
+          _26 = _1;
 -         switchInt(move _26) -> [0: bb11, otherwise: bb9];
 +         switchInt(_1) -> [0: bb11, otherwise: bb9];
       }
   
       bb9: {
           StorageLive(_27);
--         StorageLive(_28);
--         StorageLive(_29);
--         _29 = _2;
--         StorageLive(_30);
--         _30 = _3;
+          StorageLive(_28);
+          StorageLive(_29);
+          _29 = _2;
+          StorageLive(_30);
+          _30 = _3;
 -         _28 = Add(move _29, move _30);
--         StorageDead(_30);
--         StorageDead(_29);
++         _28 = _23;
+          StorageDead(_30);
+          StorageDead(_29);
 -         _27 = opaque::<u8>(move _28) -> [return: bb10, unwind continue];
 +         _27 = opaque::<u8>(_23) -> [return: bb10, unwind continue];
       }
   
       bb10: {
--         StorageDead(_28);
+          StorageDead(_28);
           StorageDead(_27);
           _0 = const ();
           goto -> bb13;
@@ -171,27 +180,28 @@
   
       bb11: {
           StorageLive(_31);
--         StorageLive(_32);
--         StorageLive(_33);
--         _33 = _2;
--         StorageLive(_34);
--         _34 = _3;
+          StorageLive(_32);
+          StorageLive(_33);
+          _33 = _2;
+          StorageLive(_34);
+          _34 = _3;
 -         _32 = Add(move _33, move _34);
--         StorageDead(_34);
--         StorageDead(_33);
++         _32 = _23;
+          StorageDead(_34);
+          StorageDead(_33);
 -         _31 = opaque::<u8>(move _32) -> [return: bb12, unwind continue];
 +         _31 = opaque::<u8>(_23) -> [return: bb12, unwind continue];
       }
   
       bb12: {
--         StorageDead(_32);
+          StorageDead(_32);
           StorageDead(_31);
           _0 = const ();
           goto -> bb13;
       }
   
       bb13: {
--         StorageDead(_26);
+          StorageDead(_26);
           return;
       }
   }

tests/mir-opt/gvn.references.GVN.panic-abort.diff

@@ -20,6 +20,24 @@
       let mut _15: *mut impl Sized;
       let _16: ();
       let mut _17: *mut impl Sized;
+      let _18: &mut impl Sized;
+      let mut _20: S<&mut impl Sized>;
+      let mut _21: &mut impl Sized;
+      let _22: ();
+      let mut _23: &impl Sized;
+      let _24: ();
+      let mut _25: &mut impl Sized;
+      let _26: ();
+      let mut _27: *const impl Sized;
+      let _28: ();
+      let mut _29: *mut impl Sized;
+      scope 1 {
+          debug r => _18;
+          let _19: &mut impl Sized;
+          scope 2 {
+              debug s => _19;
+          }
+      }
   
       bb0: {
           StorageLive(_2);
@@ -94,11 +112,68 @@
       bb8: {
           StorageDead(_17);
           StorageDead(_16);
-          _0 = const ();
-          drop(_1) -> [return: bb9, unwind unreachable];
+-         StorageLive(_18);
++         nop;
+          _18 = &mut _1;
+          StorageLive(_19);
+          StorageLive(_20);
+          StorageLive(_21);
+-         _21 = move _18;
+-         _20 = S::<&mut impl Sized>(move _21);
++         _21 = _18;
++         _20 = S::<&mut impl Sized>(_18);
+          StorageDead(_21);
+-         _19 = move (_20.0: &mut impl Sized);
++         _19 = _18;
+          StorageDead(_20);
+          StorageLive(_22);
+          StorageLive(_23);
+-         _23 = &(*_19);
++         _23 = &(*_18);
+          _22 = opaque::<&impl Sized>(move _23) -> [return: bb9, unwind unreachable];
       }
   
       bb9: {
+          StorageDead(_23);
+          StorageDead(_22);
+          StorageLive(_24);
+          StorageLive(_25);
+-         _25 = &mut (*_19);
++         _25 = &mut (*_18);
+          _24 = opaque::<&mut impl Sized>(move _25) -> [return: bb10, unwind unreachable];
+      }
+  
+      bb10: {
+          StorageDead(_25);
+          StorageDead(_24);
+          StorageLive(_26);
+          StorageLive(_27);
+-         _27 = &raw const (*_19);
++         _27 = &raw const (*_18);
+          _26 = opaque::<*const impl Sized>(move _27) -> [return: bb11, unwind unreachable];
+      }
+  
+      bb11: {
+          StorageDead(_27);
+          StorageDead(_26);
+          StorageLive(_28);
+          StorageLive(_29);
+-         _29 = &raw mut (*_19);
++         _29 = &raw mut (*_18);
+          _28 = opaque::<*mut impl Sized>(move _29) -> [return: bb12, unwind unreachable];
+      }
+  
+      bb12: {
+          StorageDead(_29);
+          StorageDead(_28);
+          _0 = const ();
+          StorageDead(_19);
+-         StorageDead(_18);
++         nop;
+          drop(_1) -> [return: bb13, unwind unreachable];
+      }
+  
+      bb13: {
           return;
       }
   }

tests/mir-opt/gvn.references.GVN.panic-unwind.diff

@@ -20,12 +20,30 @@
       let mut _15: *mut impl Sized;
       let _16: ();
       let mut _17: *mut impl Sized;
+      let _18: &mut impl Sized;
+      let mut _20: S<&mut impl Sized>;
+      let mut _21: &mut impl Sized;
+      let _22: ();
+      let mut _23: &impl Sized;
+      let _24: ();
+      let mut _25: &mut impl Sized;
+      let _26: ();
+      let mut _27: *const impl Sized;
+      let _28: ();
+      let mut _29: *mut impl Sized;
+      scope 1 {
+          debug r => _18;
+          let _19: &mut impl Sized;
+          scope 2 {
+              debug s => _19;
+          }
+      }
   
       bb0: {
           StorageLive(_2);
           StorageLive(_3);
           _3 = &_1;
-          _2 = opaque::<&impl Sized>(move _3) -> [return: bb1, unwind: bb10];
+          _2 = opaque::<&impl Sized>(move _3) -> [return: bb1, unwind: bb14];
       }
   
       bb1: {
@@ -34,7 +52,7 @@
           StorageLive(_4);
           StorageLive(_5);
           _5 = &_1;
-          _4 = opaque::<&impl Sized>(move _5) -> [return: bb2, unwind: bb10];
+          _4 = opaque::<&impl Sized>(move _5) -> [return: bb2, unwind: bb14];
       }
   
       bb2: {
@@ -43,7 +61,7 @@
           StorageLive(_6);
           StorageLive(_7);
           _7 = &mut _1;
-          _6 = opaque::<&mut impl Sized>(move _7) -> [return: bb3, unwind: bb10];
+          _6 = opaque::<&mut impl Sized>(move _7) -> [return: bb3, unwind: bb14];
       }
   
       bb3: {
@@ -52,7 +70,7 @@
           StorageLive(_8);
           StorageLive(_9);
           _9 = &mut _1;
-          _8 = opaque::<&mut impl Sized>(move _9) -> [return: bb4, unwind: bb10];
+          _8 = opaque::<&mut impl Sized>(move _9) -> [return: bb4, unwind: bb14];
       }
   
       bb4: {
@@ -61,7 +79,7 @@
           StorageLive(_10);
           StorageLive(_11);
           _11 = &raw const _1;
-          _10 = opaque::<*const impl Sized>(move _11) -> [return: bb5, unwind: bb10];
+          _10 = opaque::<*const impl Sized>(move _11) -> [return: bb5, unwind: bb14];
       }
   
       bb5: {
@@ -70,7 +88,7 @@
           StorageLive(_12);
           StorageLive(_13);
           _13 = &raw const _1;
-          _12 = opaque::<*const impl Sized>(move _13) -> [return: bb6, unwind: bb10];
+          _12 = opaque::<*const impl Sized>(move _13) -> [return: bb6, unwind: bb14];
       }
   
       bb6: {
@@ -79,7 +97,7 @@
           StorageLive(_14);
           StorageLive(_15);
           _15 = &raw mut _1;
-          _14 = opaque::<*mut impl Sized>(move _15) -> [return: bb7, unwind: bb10];
+          _14 = opaque::<*mut impl Sized>(move _15) -> [return: bb7, unwind: bb14];
       }
   
       bb7: {
@@ -88,25 +106,82 @@
           StorageLive(_16);
           StorageLive(_17);
           _17 = &raw mut _1;
-          _16 = opaque::<*mut impl Sized>(move _17) -> [return: bb8, unwind: bb10];
+          _16 = opaque::<*mut impl Sized>(move _17) -> [return: bb8, unwind: bb14];
       }
   
       bb8: {
           StorageDead(_17);
           StorageDead(_16);
-          _0 = const ();
-          drop(_1) -> [return: bb9, unwind: bb11];
+-         StorageLive(_18);
++         nop;
+          _18 = &mut _1;
+          StorageLive(_19);
+          StorageLive(_20);
+          StorageLive(_21);
+-         _21 = move _18;
+-         _20 = S::<&mut impl Sized>(move _21);
++         _21 = _18;
++         _20 = S::<&mut impl Sized>(_18);
+          StorageDead(_21);
+-         _19 = move (_20.0: &mut impl Sized);
++         _19 = _18;
+          StorageDead(_20);
+          StorageLive(_22);
+          StorageLive(_23);
+-         _23 = &(*_19);
++         _23 = &(*_18);
+          _22 = opaque::<&impl Sized>(move _23) -> [return: bb9, unwind: bb14];
       }
   
       bb9: {
+          StorageDead(_23);
+          StorageDead(_22);
+          StorageLive(_24);
+          StorageLive(_25);
+-         _25 = &mut (*_19);
++         _25 = &mut (*_18);
+          _24 = opaque::<&mut impl Sized>(move _25) -> [return: bb10, unwind: bb14];
+      }
+  
+      bb10: {
+          StorageDead(_25);
+          StorageDead(_24);
+          StorageLive(_26);
+          StorageLive(_27);
+-         _27 = &raw const (*_19);
++         _27 = &raw const (*_18);
+          _26 = opaque::<*const impl Sized>(move _27) -> [return: bb11, unwind: bb14];
+      }
+  
+      bb11: {
+          StorageDead(_27);
+          StorageDead(_26);
+          StorageLive(_28);
+          StorageLive(_29);
+-         _29 = &raw mut (*_19);
++         _29 = &raw mut (*_18);
+          _28 = opaque::<*mut impl Sized>(move _29) -> [return: bb12, unwind: bb14];
+      }
+  
+      bb12: {
+          StorageDead(_29);
+          StorageDead(_28);
+          _0 = const ();
+          StorageDead(_19);
+-         StorageDead(_18);
++         nop;
+          drop(_1) -> [return: bb13, unwind: bb15];
+      }
+  
+      bb13: {
           return;
       }
   
-      bb10 (cleanup): {
-          drop(_1) -> [return: bb11, unwind terminate(cleanup)];
+      bb14 (cleanup): {
+          drop(_1) -> [return: bb15, unwind terminate(cleanup)];
       }
   
-      bb11 (cleanup): {
+      bb15 (cleanup): {
           resume;
       }
   }

tests/mir-opt/gvn.repeat.GVN.panic-abort.diff

@@ -0,0 +1,79 @@
+- // MIR for `repeat` before GVN
++ // MIR for `repeat` after GVN
+  
+  fn repeat() -> () {
+      let mut _0: ();
+      let _1: i32;
+      let mut _3: i32;
+      let mut _4: i32;
+      let mut _5: i32;
+      let mut _6: i32;
+      let mut _7: i32;
+      let mut _8: i32;
+      let mut _9: i32;
+      let mut _10: i32;
+      let mut _11: i32;
+      let mut _12: i32;
+      scope 1 {
+          debug val => _1;
+          let _2: [i32; 10];
+          scope 2 {
+              debug array => _2;
+          }
+      }
+  
+      bb0: {
+-         StorageLive(_1);
++         nop;
+          _1 = const 5_i32;
+          StorageLive(_2);
+          StorageLive(_3);
+-         _3 = _1;
++         _3 = const 5_i32;
+          StorageLive(_4);
+-         _4 = _1;
++         _4 = const 5_i32;
+          StorageLive(_5);
+-         _5 = _1;
++         _5 = const 5_i32;
+          StorageLive(_6);
+-         _6 = _1;
++         _6 = const 5_i32;
+          StorageLive(_7);
+-         _7 = _1;
++         _7 = const 5_i32;
+          StorageLive(_8);
+-         _8 = _1;
++         _8 = const 5_i32;
+          StorageLive(_9);
+-         _9 = _1;
++         _9 = const 5_i32;
+          StorageLive(_10);
+-         _10 = _1;
++         _10 = const 5_i32;
+          StorageLive(_11);
+-         _11 = _1;
++         _11 = const 5_i32;
+          StorageLive(_12);
+-         _12 = _1;
+-         _2 = [move _3, move _4, move _5, move _6, move _7, move _8, move _9, move _10, move _11, move _12];
++         _12 = const 5_i32;
++         _2 = [const 5_i32; 10];
+          StorageDead(_12);
+          StorageDead(_11);
+          StorageDead(_10);
+          StorageDead(_9);
+          StorageDead(_8);
+          StorageDead(_7);
+          StorageDead(_6);
+          StorageDead(_5);
+          StorageDead(_4);
+          StorageDead(_3);
+          _0 = const ();
+          StorageDead(_2);
+-         StorageDead(_1);
++         nop;
+          return;
+      }
+  }
+  

tests/mir-opt/gvn.repeat.GVN.panic-unwind.diff

@@ -0,0 +1,79 @@
+- // MIR for `repeat` before GVN
++ // MIR for `repeat` after GVN
+  
+  fn repeat() -> () {
+      let mut _0: ();
+      let _1: i32;
+      let mut _3: i32;
+      let mut _4: i32;
+      let mut _5: i32;
+      let mut _6: i32;
+      let mut _7: i32;
+      let mut _8: i32;
+      let mut _9: i32;
+      let mut _10: i32;
+      let mut _11: i32;
+      let mut _12: i32;
+      scope 1 {
+          debug val => _1;
+          let _2: [i32; 10];
+          scope 2 {
+              debug array => _2;
+          }
+      }
+  
+      bb0: {
+-         StorageLive(_1);
++         nop;
+          _1 = const 5_i32;
+          StorageLive(_2);
+          StorageLive(_3);
+-         _3 = _1;
++         _3 = const 5_i32;
+          StorageLive(_4);
+-         _4 = _1;
++         _4 = const 5_i32;
+          StorageLive(_5);
+-         _5 = _1;
++         _5 = const 5_i32;
+          StorageLive(_6);
+-         _6 = _1;
++         _6 = const 5_i32;
+          StorageLive(_7);
+-         _7 = _1;
++         _7 = const 5_i32;
+          StorageLive(_8);
+-         _8 = _1;
++         _8 = const 5_i32;
+          StorageLive(_9);
+-         _9 = _1;
++         _9 = const 5_i32;
+          StorageLive(_10);
+-         _10 = _1;
++         _10 = const 5_i32;
+          StorageLive(_11);
+-         _11 = _1;
++         _11 = const 5_i32;
+          StorageLive(_12);
+-         _12 = _1;
+-         _2 = [move _3, move _4, move _5, move _6, move _7, move _8, move _9, move _10, move _11, move _12];
++         _12 = const 5_i32;
++         _2 = [const 5_i32; 10];
+          StorageDead(_12);
+          StorageDead(_11);
+          StorageDead(_10);
+          StorageDead(_9);
+          StorageDead(_8);
+          StorageDead(_7);
+          StorageDead(_6);
+          StorageDead(_5);
+          StorageDead(_4);
+          StorageDead(_3);
+          _0 = const ();
+          StorageDead(_2);
+-         StorageDead(_1);
++         nop;
+          return;
+      }
+  }
+  

tests/mir-opt/gvn.repeated_index.GVN.panic-abort.diff

@@ -23,11 +23,11 @@
   
       bb0: {
           StorageLive(_3);
--         StorageLive(_4);
--         _4 = _1;
+          StorageLive(_4);
+          _4 = _1;
 -         _3 = [move _4; N];
--         StorageDead(_4);
 +         _3 = [_1; N];
+          StorageDead(_4);
           StorageLive(_5);
           StorageLive(_6);
           StorageLive(_7);
@@ -40,8 +40,10 @@
       }
   
       bb1: {
-          _6 = _3[_7];
-          _5 = opaque::<T>(move _6) -> [return: bb2, unwind unreachable];
+-         _6 = _3[_7];
+-         _5 = opaque::<T>(move _6) -> [return: bb2, unwind unreachable];
++         _6 = _1;
++         _5 = opaque::<T>(_1) -> [return: bb2, unwind unreachable];
       }
   
       bb2: {
@@ -55,13 +57,16 @@
 -         _13 = Len(_3);
 -         _14 = Lt(_12, _13);
 -         assert(move _14, "index out of bounds: the length is {} but the index is {}", move _13, _12) -> [success: bb3, unwind unreachable];
++         _13 = _8;
 +         _14 = Lt(_2, _8);
 +         assert(move _14, "index out of bounds: the length is {} but the index is {}", _8, _2) -> [success: bb3, unwind unreachable];
       }
   
       bb3: {
-          _11 = _3[_12];
-          _10 = opaque::<T>(move _11) -> [return: bb4, unwind unreachable];
+-         _11 = _3[_12];
+-         _10 = opaque::<T>(move _11) -> [return: bb4, unwind unreachable];
++         _11 = _1;
++         _10 = opaque::<T>(_1) -> [return: bb4, unwind unreachable];
       }
   
       bb4: {

tests/mir-opt/gvn.repeated_index.GVN.panic-unwind.diff

@@ -23,11 +23,11 @@
   
       bb0: {
           StorageLive(_3);
--         StorageLive(_4);
--         _4 = _1;
+          StorageLive(_4);
+          _4 = _1;
 -         _3 = [move _4; N];
--         StorageDead(_4);
 +         _3 = [_1; N];
+          StorageDead(_4);
           StorageLive(_5);
           StorageLive(_6);
           StorageLive(_7);
@@ -40,8 +40,10 @@
       }
   
       bb1: {
-          _6 = _3[_7];
-          _5 = opaque::<T>(move _6) -> [return: bb2, unwind continue];
+-         _6 = _3[_7];
+-         _5 = opaque::<T>(move _6) -> [return: bb2, unwind continue];
++         _6 = _1;
++         _5 = opaque::<T>(_1) -> [return: bb2, unwind continue];
       }
   
       bb2: {
@@ -55,13 +57,16 @@
 -         _13 = Len(_3);
 -         _14 = Lt(_12, _13);
 -         assert(move _14, "index out of bounds: the length is {} but the index is {}", move _13, _12) -> [success: bb3, unwind continue];
++         _13 = _8;
 +         _14 = Lt(_2, _8);
 +         assert(move _14, "index out of bounds: the length is {} but the index is {}", _8, _2) -> [success: bb3, unwind continue];
       }
   
       bb3: {
-          _11 = _3[_12];
-          _10 = opaque::<T>(move _11) -> [return: bb4, unwind continue];
+-         _11 = _3[_12];
+-         _10 = opaque::<T>(move _11) -> [return: bb4, unwind continue];
++         _11 = _1;
++         _10 = opaque::<T>(_1) -> [return: bb4, unwind continue];
       }
   
       bb4: {

tests/mir-opt/gvn.rs

@@ -1,56 +1,133 @@
-// skip-filecheck
 // unit-test: GVN
 // EMIT_MIR_FOR_EACH_PANIC_STRATEGY
+// only-64bit
 
 #![feature(raw_ref_op)]
 #![feature(rustc_attrs)]
+#![feature(custom_mir)]
+#![feature(core_intrinsics)]
 #![allow(unconditional_panic)]
 
+use std::intrinsics::mir::*;
+use std::mem::transmute;
+
 struct S<T>(T);
 
 fn subexpression_elimination(x: u64, y: u64, mut z: u64) {
+    // CHECK-LABEL: fn subexpression_elimination(
+
+    // CHECK: [[add:_.*]] = Add(_1, _2);
+    // CHECK: opaque::<u64>([[add]])
     opaque(x + y);
+    // CHECK: [[mul:_.*]] = Mul(_1, _2);
+    // CHECK: opaque::<u64>([[mul]])
     opaque(x * y);
+    // CHECK: [[sub:_.*]] = Sub(_1, _2);
+    // CHECK: opaque::<u64>([[sub]])
     opaque(x - y);
+    // CHECK: [[div:_.*]] = Div(_1, _2);
+    // CHECK: opaque::<u64>([[div]])
     opaque(x / y);
+    // CHECK: [[rem:_.*]] = Rem(_1, _2);
+    // CHECK: opaque::<u64>([[rem]])
     opaque(x % y);
+    // CHECK: [[and:_.*]] = BitAnd(_1, _2);
+    // CHECK: opaque::<u64>([[and]])
     opaque(x & y);
+    // CHECK: [[or:_.*]] = BitOr(_1, _2);
+    // CHECK: opaque::<u64>([[or]])
     opaque(x | y);
+    // CHECK: [[xor:_.*]] = BitXor(_1, _2);
+    // CHECK: opaque::<u64>([[xor]])
     opaque(x ^ y);
+    // CHECK: [[shl:_.*]] = Shl(_1, _2);
+    // CHECK: opaque::<u64>([[shl]])
     opaque(x << y);
+    // CHECK: [[shr:_.*]] = Shr(_1, _2);
+    // CHECK: opaque::<u64>([[shr]])
     opaque(x >> y);
+    // CHECK: [[int:_.*]] = _1 as u32 (IntToInt);
+    // CHECK: opaque::<u32>([[int]])
     opaque(x as u32);
+    // CHECK: [[float:_.*]] = _1 as f32 (IntToFloat);
+    // CHECK: opaque::<f32>([[float]])
     opaque(x as f32);
+    // CHECK: [[wrap:_.*]] = S::<u64>(_1);
+    // CHECK: opaque::<S<u64>>([[wrap]])
     opaque(S(x));
+    // CHECK: opaque::<u64>(_1)
     opaque(S(x).0);
 
     // Those are duplicates to substitute somehow.
-    opaque((x + y) + z);
-    opaque((x * y) + z);
-    opaque((x - y) + z);
-    opaque((x / y) + z);
-    opaque((x % y) + z);
-    opaque((x & y) + z);
-    opaque((x | y) + z);
-    opaque((x ^ y) + z);
-    opaque((x << y) + z);
-    opaque((x >> y) + z);
+    // CHECK: opaque::<u64>([[add]])
+    opaque(x + y);
+    // CHECK: opaque::<u64>([[mul]])
+    opaque(x * y);
+    // CHECK: opaque::<u64>([[sub]])
+    opaque(x - y);
+    // CHECK: opaque::<u64>([[div]])
+    opaque(x / y);
+    // CHECK: opaque::<u64>([[rem]])
+    opaque(x % y);
+    // CHECK: opaque::<u64>([[and]])
+    opaque(x & y);
+    // CHECK: opaque::<u64>([[or]])
+    opaque(x | y);
+    // CHECK: opaque::<u64>([[xor]])
+    opaque(x ^ y);
+    // CHECK: opaque::<u64>([[shl]])
+    opaque(x << y);
+    // CHECK: opaque::<u64>([[shr]])
+    opaque(x >> y);
+    // CHECK: opaque::<u32>([[int]])
+    opaque(x as u32);
+    // CHECK: opaque::<f32>([[float]])
+    opaque(x as f32);
+    // CHECK: opaque::<S<u64>>([[wrap]])
     opaque(S(x));
+    // CHECK: opaque::<u64>(_1)
     opaque(S(x).0);
 
+    // We can substitute through a complex expression.
+    // CHECK: [[compound:_.*]] = Sub([[mul]], _2);
+    // CHECK: opaque::<u64>([[compound]])
+    // CHECK: opaque::<u64>([[compound]])
+    opaque((x * y) - y);
+    opaque((x * y) - y);
+
     // We can substitute through an immutable reference too.
+    // CHECK: [[ref:_.*]] = &_3;
+    // CHECK: [[deref:_.*]] = (*[[ref]]);
+    // CHECK: [[addref:_.*]] = Add([[deref]], _1);
+    // CHECK: opaque::<u64>([[addref]])
+    // CHECK: opaque::<u64>([[addref]])
     let a = &z;
     opaque(*a + x);
     opaque(*a + x);
 
     // But not through a mutable reference or a pointer.
+    // CHECK: [[mut:_.*]] = &mut _3;
+    // CHECK: [[addmut:_.*]] = Add(
+    // CHECK: opaque::<u64>(move [[addmut]])
+    // CHECK: [[addmut2:_.*]] = Add(
+    // CHECK: opaque::<u64>(move [[addmut2]])
     let b = &mut z;
     opaque(*b + x);
     opaque(*b + x);
     unsafe {
+        // CHECK: [[raw:_.*]] = &raw const _3;
+        // CHECK: [[addraw:_.*]] = Add(
+        // CHECK: opaque::<u64>(move [[addraw]])
+        // CHECK: [[addraw2:_.*]] = Add(
+        // CHECK: opaque::<u64>(move [[addraw2]])
         let c = &raw const z;
         opaque(*c + x);
         opaque(*c + x);
+        // CHECK: [[ptr:_.*]] = &raw mut _3;
+        // CHECK: [[addptr:_.*]] = Add(
+        // CHECK: opaque::<u64>(move [[addptr]])
+        // CHECK: [[addptr2:_.*]] = Add(
+        // CHECK: opaque::<u64>(move [[addptr2]])
         let d = &raw mut z;
         opaque(*d + x);
         opaque(*d + x);
@@ -58,13 +135,21 @@ fn subexpression_elimination(x: u64, y: u64, mut z: u64) {
 
     // We can substitute again, but not with the earlier computations.
     // Important: `e` is not `a`!
+    // CHECK: [[ref2:_.*]] = &_3;
+    // CHECK: [[deref2:_.*]] = (*[[ref2]]);
+    // CHECK: [[addref2:_.*]] = Add([[deref2]], _1);
+    // CHECK: opaque::<u64>([[addref2]])
+    // CHECK: opaque::<u64>([[addref2]])
     let e = &z;
     opaque(*e + x);
     opaque(*e + x);
-
 }
 
 fn wrap_unwrap<T: Copy>(x: T) -> T {
+    // CHECK-LABEL: fn wrap_unwrap(
+    // CHECK: [[some:_.*]] = Option::<T>::Some(_1);
+    // CHECK: switchInt(const 1_isize)
+    // CHECK: _0 = _1;
     match Some(x) {
         Some(y) => y,
         None => panic!(),
@@ -72,163 +157,464 @@ fn wrap_unwrap<T: Copy>(x: T) -> T {
 }
 
 fn repeated_index<T: Copy, const N: usize>(x: T, idx: usize) {
+    // CHECK-LABEL: fn repeated_index(
+    // CHECK: [[a:_.*]] = [_1; N];
     let a = [x; N];
+    // CHECK: opaque::<T>(_1)
     opaque(a[0]);
+    // CHECK: opaque::<T>(_1)
     opaque(a[idx]);
 }
 
+/// Verify symbolic integer arithmetic simplifications.
 fn arithmetic(x: u64) {
+    // CHECK-LABEL: fn arithmetic(
+    // CHECK: [[add:_.*]] = Add(_1, const 0_u64);
+    // CHECK: opaque::<u64>(move [[add]])
     opaque(x + 0);
+    // CHECK: [[sub:_.*]] = Sub(_1, const 0_u64);
+    // CHECK: opaque::<u64>(move [[sub]])
     opaque(x - 0);
+    // CHECK: [[mul0:_.*]] = Mul(_1, const 0_u64);
+    // CHECK: opaque::<u64>(move [[mul0]])
     opaque(x * 0);
+    // CHECK: [[mul1:_.*]] = Mul(_1, const 1_u64);
+    // CHECK: opaque::<u64>(move [[mul1]])
     opaque(x * 1);
+    // CHECK: [[div0:_.*]] = Div(_1, const 0_u64);
+    // CHECK: opaque::<u64>(move [[div0]])
     opaque(x / 0);
+    // CHECK: [[div1:_.*]] = Div(_1, const 1_u64);
+    // CHECK: opaque::<u64>(move [[div1]])
     opaque(x / 1);
+    // CHECK: [[zdiv:_.*]] = Div(const 0_u64, _1);
+    // CHECK: opaque::<u64>(move [[zdiv]])
     opaque(0 / x);
+    // CHECK: [[odiv:_.*]] = Div(const 1_u64, _1);
+    // CHECK: opaque::<u64>(move [[odiv]])
     opaque(1 / x);
+    // CHECK: [[rem0:_.*]] = Rem(_1, const 0_u64);
+    // CHECK: opaque::<u64>(move [[rem0]])
     opaque(x % 0);
+    // CHECK: [[rem1:_.*]] = Rem(_1, const 1_u64);
+    // CHECK: opaque::<u64>(move [[rem1]])
     opaque(x % 1);
+    // CHECK: [[zrem:_.*]] = Rem(const 0_u64, _1);
+    // CHECK: opaque::<u64>(move [[zrem]])
     opaque(0 % x);
+    // CHECK: [[orem:_.*]] = Rem(const 1_u64, _1);
+    // CHECK: opaque::<u64>(move [[orem]])
     opaque(1 % x);
+    // CHECK: [[and:_.*]] = BitAnd(_1, const 0_u64);
+    // CHECK: opaque::<u64>(move [[and]])
     opaque(x & 0);
+    // CHECK: [[or:_.*]] = BitOr(_1, const 0_u64);
+    // CHECK: opaque::<u64>(move [[or]])
     opaque(x | 0);
+    // CHECK: [[xor:_.*]] = BitXor(_1, const 0_u64);
+    // CHECK: opaque::<u64>(move [[xor]])
     opaque(x ^ 0);
+    // CHECK: [[shr:_.*]] = Shr(_1, const 0_i32);
+    // CHECK: opaque::<u64>(move [[shr]])
     opaque(x >> 0);
+    // CHECK: [[shl:_.*]] = Shl(_1, const 0_i32);
+    // CHECK: opaque::<u64>(move [[shl]])
     opaque(x << 0);
 }
 
+fn comparison(x: u64, y: u64) {
+    // CHECK-LABEL: fn comparison(
+    // CHECK: [[eqxx:_.*]] = Eq(_1, _1);
+    // CHECK: opaque::<bool>(move [[eqxx]])
+    opaque(x == x);
+    // CHECK: [[nexx:_.*]] = Ne(_1, _1);
+    // CHECK: opaque::<bool>(move [[nexx]])
+    opaque(x != x);
+    // CHECK: [[eqxy:_.*]] = Eq(_1, _2);
+    // CHECK: opaque::<bool>(move [[eqxy]])
+    opaque(x == y);
+    // CHECK: [[nexy:_.*]] = Ne(_1, _2);
+    // CHECK: opaque::<bool>(move [[nexy]])
+    opaque(x != y);
+}
+
+/// Verify symbolic integer arithmetic simplifications on checked ops.
 #[rustc_inherit_overflow_checks]
 fn arithmetic_checked(x: u64) {
+    // CHECK-LABEL: fn arithmetic_checked(
+    // CHECK: [[cadd:_.*]] = CheckedAdd(_1, const 0_u64);
+    // CHECK: [[add:_.*]] = move ([[cadd]].0: u64);
+    // CHECK: opaque::<u64>(move [[add]])
     opaque(x + 0);
+    // CHECK: [[csub:_.*]] = CheckedSub(_1, const 0_u64);
+    // CHECK: [[sub:_.*]] = move ([[csub]].0: u64);
+    // CHECK: opaque::<u64>(move [[sub]])
     opaque(x - 0);
+    // CHECK: [[cmul0:_.*]] = CheckedMul(_1, const 0_u64);
+    // CHECK: [[mul0:_.*]] = move ([[cmul0]].0: u64);
+    // CHECK: opaque::<u64>(move [[mul0]])
     opaque(x * 0);
+    // CHECK: [[cmul1:_.*]] = CheckedMul(_1, const 1_u64);
+    // CHECK: [[mul1:_.*]] = move ([[cmul1]].0: u64);
+    // CHECK: opaque::<u64>(move [[mul1]])
     opaque(x * 1);
-    opaque(x / 0);
-    opaque(x / 1);
-    opaque(0 / x);
-    opaque(1 / x);
-    opaque(x % 0);
-    opaque(x % 1);
-    opaque(0 % x);
-    opaque(1 % x);
-    opaque(x & 0);
-    opaque(x | 0);
-    opaque(x ^ 0);
-    opaque(x >> 0);
-    opaque(x << 0);
 }
 
+/// Verify that we do not apply arithmetic simplifications on floats.
 fn arithmetic_float(x: f64) {
+    // CHECK-LABEL: fn arithmetic_float(
+    // CHECK: [[add:_.*]] = Add(_1, const 0f64);
+    // CHECK: opaque::<f64>(move [[add]])
     opaque(x + 0.);
+    // CHECK: [[sub:_.*]] = Sub(_1, const 0f64);
+    // CHECK: opaque::<f64>(move [[sub]])
     opaque(x - 0.);
+    // CHECK: [[mul:_.*]] = Mul(_1, const 0f64);
+    // CHECK: opaque::<f64>(move [[mul]])
     opaque(x * 0.);
+    // CHECK: [[div0:_.*]] = Div(_1, const 0f64);
+    // CHECK: opaque::<f64>(move [[div0]])
     opaque(x / 0.);
+    // CHECK: [[zdiv:_.*]] = Div(const 0f64, _1);
+    // CHECK: opaque::<f64>(move [[zdiv]])
     opaque(0. / x);
+    // CHECK: [[rem0:_.*]] = Rem(_1, const 0f64);
+    // CHECK: opaque::<f64>(move [[rem0]])
     opaque(x % 0.);
+    // CHECK: [[zrem:_.*]] = Rem(const 0f64, _1);
+    // CHECK: opaque::<f64>(move [[zrem]])
     opaque(0. % x);
     // Those are not simplifiable to `true`/`false`, thanks to NaNs.
+    // CHECK: [[eq:_.*]] = Eq(_1, _1);
+    // CHECK: opaque::<bool>(move [[eq]])
     opaque(x == x);
+    // CHECK: [[ne:_.*]] = Ne(_1, _1);
+    // CHECK: opaque::<bool>(move [[ne]])
     opaque(x != x);
 }
 
 fn cast() {
+    // CHECK-LABEL: fn cast(
     let i = 1_i64;
     let u = 1_u64;
     let f = 1_f64;
+    // CHECK: opaque::<u8>(const 1_u8)
     opaque(i as u8);
+    // CHECK: opaque::<u16>(const 1_u16)
     opaque(i as u16);
+    // CHECK: opaque::<u32>(const 1_u32)
     opaque(i as u32);
+    // CHECK: opaque::<u64>(const 1_u64)
     opaque(i as u64);
+    // CHECK: opaque::<i8>(const 1_i8)
     opaque(i as i8);
+    // CHECK: opaque::<i16>(const 1_i16)
     opaque(i as i16);
+    // CHECK: opaque::<i32>(const 1_i32)
     opaque(i as i32);
+    // CHECK: opaque::<i64>(const 1_i64)
     opaque(i as i64);
+    // CHECK: opaque::<f32>(const 1f32)
     opaque(i as f32);
+    // CHECK: opaque::<f64>(const 1f64)
     opaque(i as f64);
+    // CHECK: opaque::<u8>(const 1_u8)
     opaque(u as u8);
+    // CHECK: opaque::<u16>(const 1_u16)
     opaque(u as u16);
+    // CHECK: opaque::<u32>(const 1_u32)
     opaque(u as u32);
+    // CHECK: opaque::<u64>(const 1_u64)
     opaque(u as u64);
+    // CHECK: opaque::<i8>(const 1_i8)
     opaque(u as i8);
+    // CHECK: opaque::<i16>(const 1_i16)
     opaque(u as i16);
+    // CHECK: opaque::<i32>(const 1_i32)
     opaque(u as i32);
+    // CHECK: opaque::<i64>(const 1_i64)
     opaque(u as i64);
+    // CHECK: opaque::<f32>(const 1f32)
     opaque(u as f32);
+    // CHECK: opaque::<f64>(const 1f64)
     opaque(u as f64);
+    // CHECK: opaque::<u8>(const 1_u8)
     opaque(f as u8);
+    // CHECK: opaque::<u16>(const 1_u16)
     opaque(f as u16);
+    // CHECK: opaque::<u32>(const 1_u32)
     opaque(f as u32);
+    // CHECK: opaque::<u64>(const 1_u64)
     opaque(f as u64);
+    // CHECK: opaque::<i8>(const 1_i8)
     opaque(f as i8);
+    // CHECK: opaque::<i16>(const 1_i16)
     opaque(f as i16);
+    // CHECK: opaque::<i32>(const 1_i32)
     opaque(f as i32);
+    // CHECK: opaque::<i64>(const 1_i64)
     opaque(f as i64);
+    // CHECK: opaque::<f32>(const 1f32)
     opaque(f as f32);
+    // CHECK: opaque::<f64>(const 1f64)
     opaque(f as f64);
 }
 
 fn multiple_branches(t: bool, x: u8, y: u8) {
+    // CHECK-LABEL: fn multiple_branches(
+    // CHECK: switchInt(_1) -> [0: [[bbf:bb.*]], otherwise: [[bbt:bb.*]]];
     if t {
-        opaque(x + y); // a
-        opaque(x + y); // should reuse a
+        // CHECK: [[bbt]]: {
+        // CHECK: [[a:_.*]] = Add(_2, _3);
+        // CHECK: opaque::<u8>([[a]])
+        // CHECK: opaque::<u8>([[a]])
+        // CHECK: goto -> [[bbc:bb.*]];
+        opaque(x + y);
+        opaque(x + y);
     } else {
-        opaque(x + y); // b
-        opaque(x + y); // shoud reuse b
+        // CHECK: [[bbf]]: {
+        // CHECK: [[b:_.*]] = Add(_2, _3);
+        // CHECK: opaque::<u8>([[b]])
+        // CHECK: opaque::<u8>([[b]])
+        // CHECK: goto -> [[bbc:bb.*]];
+        opaque(x + y);
+        opaque(x + y);
     }
-    opaque(x + y); // c
+    // Neither `a` nor `b` dominate `c`, so we cannot reuse any of them.
+    // CHECK: [[bbc]]: {
+    // CHECK: [[c:_.*]] = Add(_2, _3);
+    // CHECK: opaque::<u8>([[c]])
+    opaque(x + y);
+
+    // `c` dominates both calls, so we can reuse it.
     if t {
-        opaque(x + y); // should reuse c
+        // CHECK: opaque::<u8>([[c]])
+        opaque(x + y);
     } else {
-        opaque(x + y); // should reuse c
+        // CHECK: opaque::<u8>([[c]])
+        opaque(x + y);
     }
 }
 
+/// Verify that we do not reuse a `&raw? mut?` rvalue.
 fn references(mut x: impl Sized) {
+    // CHECK-LABEL: fn references(
+    // CHECK: [[ref1:_.*]] = &_1;
+    // CHECK: opaque::<&impl Sized>(move [[ref1]])
     opaque(&x);
-    opaque(&x); // should not reuse a
+    // CHECK: [[ref2:_.*]] = &_1;
+    // CHECK: opaque::<&impl Sized>(move [[ref2]])
+    opaque(&x);
+    // CHECK: [[ref3:_.*]] = &mut _1;
+    // CHECK: opaque::<&mut impl Sized>(move [[ref3]])
     opaque(&mut x);
-    opaque(&mut x); // should not reuse a
+    // CHECK: [[ref4:_.*]] = &mut _1;
+    // CHECK: opaque::<&mut impl Sized>(move [[ref4]])
+    opaque(&mut x);
+    // CHECK: [[ref5:_.*]] = &raw const _1;
+    // CHECK: opaque::<*const impl Sized>(move [[ref5]])
     opaque(&raw const x);
-    opaque(&raw const x); // should not reuse a
+    // CHECK: [[ref6:_.*]] = &raw const _1;
+    // CHECK: opaque::<*const impl Sized>(move [[ref6]])
+    opaque(&raw const x);
+    // CHECK: [[ref7:_.*]] = &raw mut _1;
+    // CHECK: opaque::<*mut impl Sized>(move [[ref7]])
     opaque(&raw mut x);
-    opaque(&raw mut x); // should not reuse a
+    // CHECK: [[ref8:_.*]] = &raw mut _1;
+    // CHECK: opaque::<*mut impl Sized>(move [[ref8]])
+    opaque(&raw mut x);
+
+    let r = &mut x;
+    let s = S(r).0; // Obfuscate `r`. Following lines should still reborrow `r`.
+    // CHECK: [[ref9:_.*]] = &mut _1;
+    // CHECK: [[ref10:_.*]] = &(*[[ref9]]);
+    // CHECK: opaque::<&impl Sized>(move [[ref10]])
+    opaque(&*s);
+    // CHECK: [[ref11:_.*]] = &mut (*[[ref9]]);
+    // CHECK: opaque::<&mut impl Sized>(move [[ref11]])
+    opaque(&mut *s);
+    // CHECK: [[ref12:_.*]] = &raw const (*[[ref9]]);
+    // CHECK: opaque::<*const impl Sized>(move [[ref12]])
+    opaque(&raw const *s);
+    // CHECK: [[ref12:_.*]] = &raw mut (*[[ref9]]);
+    // CHECK: opaque::<*mut impl Sized>(move [[ref12]])
+    opaque(&raw mut *s);
 }
 
 fn dereferences(t: &mut u32, u: &impl Copy, s: &S<u32>) {
+    // CHECK-LABEL: fn dereferences(
+
+    // Do not reuse dereferences of `&mut`.
+    // CHECK: [[st1:_.*]] = (*_1);
+    // CHECK: opaque::<u32>(move [[st1]])
+    // CHECK: [[st2:_.*]] = (*_1);
+    // CHECK: opaque::<u32>(move [[st2]])
     opaque(*t);
-    opaque(*t); // this cannot reuse a, as x is &mut.
+    opaque(*t);
+
+    // Do not reuse dereferences of `*const`.
+    // CHECK: [[raw:_.*]] = &raw const (*_1);
+    // CHECK: [[st3:_.*]] = (*[[raw]]);
+    // CHECK: opaque::<u32>(move [[st3]])
+    // CHECK: [[st4:_.*]] = (*[[raw]]);
+    // CHECK: opaque::<u32>(move [[st4]])
     let z = &raw const *t;
     unsafe { opaque(*z) };
-    unsafe { opaque(*z) }; // this cannot reuse a, as x is *const.
+    unsafe { opaque(*z) };
+
+    // Do not reuse dereferences of `*mut`.
+    // CHECK: [[ptr:_.*]] = &raw mut (*_1);
+    // CHECK: [[st5:_.*]] = (*[[ptr]]);
+    // CHECK: opaque::<u32>(move [[st5]])
+    // CHECK: [[st6:_.*]] = (*[[ptr]]);
+    // CHECK: opaque::<u32>(move [[st6]])
     let z = &raw mut *t;
     unsafe { opaque(*z) };
-    unsafe { opaque(*z) }; // this cannot reuse a, as x is *mut.
+    unsafe { opaque(*z) };
+
+    // We can reuse dereferences of `&Freeze`.
+    // CHECK: [[ref:_.*]] = &(*_1);
+    // CHECK: [[st7:_.*]] = (*[[ref]]);
+    // CHECK: opaque::<u32>([[st7]])
+    // CHECK: opaque::<u32>([[st7]])
     let z = &*t;
     opaque(*z);
-    opaque(*z); // this can reuse, as `z` is immutable ref, Freeze and Copy.
-    opaque(&*z); // but not for a reborrow.
+    opaque(*z);
+    // But not in reborrows.
+    // CHECK: [[reborrow:_.*]] = &(*[[ref]]);
+    // CHECK: opaque::<&u32>(move [[reborrow]])
+    opaque(&*z);
+
+    // `*u` is not Freeze, so we cannot reuse.
+    // CHECK: [[st8:_.*]] = (*_2);
+    // CHECK: opaque::<impl Copy>(move [[st8]])
+    // CHECK: [[st9:_.*]] = (*_2);
+    // CHECK: opaque::<impl Copy>(move [[st9]])
     opaque(*u);
-    opaque(*u); // this cannot reuse, as `z` is not Freeze.
+    opaque(*u);
+
+    // `*s` is not Copy, by `(*s).0` is, so we can reuse.
+    // CHECK: [[st10:_.*]] = ((*_3).0: u32);
+    // CHECK: opaque::<u32>([[st10]])
+    // CHECK: opaque::<u32>([[st10]])
+    opaque(s.0);
     opaque(s.0);
-    opaque(s.0); // *s is not Copy, by (*s).0 is, so we can reuse.
 }
 
 fn slices() {
+    // CHECK-LABEL: fn slices(
+    // CHECK: {{_.*}} = const "
+    // CHECK-NOT: {{_.*}} = const "
     let s = "my favourite slice"; // This is a `Const::Slice` in MIR.
     opaque(s);
     let t = s; // This should be the same pointer, so cannot be a `Const::Slice`.
     opaque(t);
     assert_eq!(s.as_ptr(), t.as_ptr());
-    let u = unsafe { std::mem::transmute::<&str, &[u8]>(s) };
+    let u = unsafe { transmute::<&str, &[u8]>(s) };
     opaque(u);
     assert_eq!(s.as_ptr(), u.as_ptr());
 }
 
+#[custom_mir(dialect = "analysis")]
+fn duplicate_slice() -> (bool, bool) {
+    // CHECK-LABEL: fn duplicate_slice(
+    mir!(
+        let au: u128;
+        let bu: u128;
+        let cu: u128;
+        let du: u128;
+        let c: &str;
+        let d: &str;
+        {
+            // CHECK: [[a:_.*]] = (const "a",);
+            // CHECK: [[au:_.*]] = ([[a]].0: &str) as u128 (Transmute);
+            let a = ("a",);
+            Call(au = transmute::<_, u128>(a.0), bb1)
+        }
+        bb1 = {
+            // CHECK: [[c:_.*]] = identity::<&str>(([[a]].0: &str))
+            Call(c = identity(a.0), bb2)
+        }
+        bb2 = {
+            // CHECK: [[cu:_.*]] = [[c]] as u128 (Transmute);
+            Call(cu = transmute::<_, u128>(c), bb3)
+        }
+        bb3 = {
+            // This slice is different from `a.0`. Hence `bu` is not `au`.
+            // CHECK: [[b:_.*]] = const "a";
+            // CHECK: [[bu:_.*]] = [[b]] as u128 (Transmute);
+            let b = "a";
+            Call(bu = transmute::<_, u128>(b), bb4)
+        }
+        bb4 = {
+            // This returns a copy of `b`, which is not `a`.
+            // CHECK: [[d:_.*]] = identity::<&str>([[b]])
+            Call(d = identity(b), bb5)
+        }
+        bb5 = {
+            // CHECK: [[du:_.*]] = [[d]] as u128 (Transmute);
+            Call(du = transmute::<_, u128>(d), bb6)
+        }
+        bb6 = {
+            // `direct` must not fold to `true`, as `indirect` will not.
+            // CHECK: = Eq([[au]], [[bu]]);
+            // CHECK: = Eq([[cu]], [[du]]);
+            let direct = au == bu;
+            let indirect = cu == du;
+            RET = (direct, indirect);
+            Return()
+        }
+    )
+}
+
+fn repeat() {
+    // CHECK-LABEL: fn repeat(
+    // CHECK: = [const 5_i32; 10];
+    let val = 5;
+    let array = [val, val, val, val, val, val, val, val, val, val];
+}
+
+/// Verify that we do not merge fn pointers created by casts.
+fn fn_pointers() {
+    // CHECK-LABEL: fn fn_pointers(
+    // CHECK: [[f:_.*]] = identity::<u8> as fn(u8) -> u8 (PointerCoercion(ReifyFnPointer
+    // CHECK: opaque::<fn(u8) -> u8>([[f]])
+    let f = identity as fn(u8) -> u8;
+    opaque(f);
+    // CHECK: [[g:_.*]] = identity::<u8> as fn(u8) -> u8 (PointerCoercion(ReifyFnPointer
+    // CHECK: opaque::<fn(u8) -> u8>([[g]])
+    let g = identity as fn(u8) -> u8;
+    opaque(g);
+
+    // CHECK: [[cf:_.*]] = const {{.*}} as fn() (PointerCoercion(ClosureFnPointer
+    // CHECK: opaque::<fn()>([[cf]])
+    let closure = || {};
+    let cf = closure as fn();
+    opaque(cf);
+    // CHECK: [[cg:_.*]] = const {{.*}} as fn() (PointerCoercion(ClosureFnPointer
+    // CHECK: opaque::<fn()>([[cg]])
+    let cg = closure as fn();
+    opaque(cg);
+}
+
+/// Verify that we do not create a `ConstValue::Indirect` backed by a static's AllocId.
+#[custom_mir(dialect = "analysis")]
+fn indirect_static() {
+    static A: Option<u8> = None;
+
+    mir!({
+        let ptr = Static(A);
+        let out = Field::<u8>(Variant(*ptr, 1), 0);
+        Return()
+    })
+}
+
 fn main() {
     subexpression_elimination(2, 4, 5);
     wrap_unwrap(5);
     repeated_index::<u32, 7>(5, 3);
     arithmetic(5);
+    comparison(5, 6);
     arithmetic_checked(5);
     arithmetic_float(5.);
     cast();
@@ -236,15 +622,26 @@ fn main() {
     references(5);
     dereferences(&mut 5, &6, &S(7));
     slices();
+    let (direct, indirect) = duplicate_slice();
+    assert_eq!(direct, indirect);
+    repeat();
+    fn_pointers();
+    indirect_static();
 }
 
 #[inline(never)]
 fn opaque(_: impl Sized) {}
 
+#[inline(never)]
+fn identity<T>(x: T) -> T {
+    x
+}
+
 // EMIT_MIR gvn.subexpression_elimination.GVN.diff
 // EMIT_MIR gvn.wrap_unwrap.GVN.diff
 // EMIT_MIR gvn.repeated_index.GVN.diff
 // EMIT_MIR gvn.arithmetic.GVN.diff
+// EMIT_MIR gvn.comparison.GVN.diff
 // EMIT_MIR gvn.arithmetic_checked.GVN.diff
 // EMIT_MIR gvn.arithmetic_float.GVN.diff
 // EMIT_MIR gvn.cast.GVN.diff
@@ -252,3 +649,7 @@ fn opaque(_: impl Sized) {}
 // EMIT_MIR gvn.references.GVN.diff
 // EMIT_MIR gvn.dereferences.GVN.diff
 // EMIT_MIR gvn.slices.GVN.diff
+// EMIT_MIR gvn.duplicate_slice.GVN.diff
+// EMIT_MIR gvn.repeat.GVN.diff
+// EMIT_MIR gvn.fn_pointers.GVN.diff
+// EMIT_MIR gvn.indirect_static.GVN.diff

tests/mir-opt/gvn.slices.GVN.panic-abort.diff

@@ -85,32 +85,35 @@
   
       bb0: {
 -         StorageLive(_1);
++         nop;
           _1 = const "my favourite slice";
           StorageLive(_2);
--         StorageLive(_3);
--         _3 = _1;
+          StorageLive(_3);
+          _3 = _1;
 -         _2 = opaque::<&str>(move _3) -> [return: bb1, unwind unreachable];
 +         _2 = opaque::<&str>(_1) -> [return: bb1, unwind unreachable];
       }
   
       bb1: {
--         StorageDead(_3);
+          StorageDead(_3);
           StorageDead(_2);
           StorageLive(_4);
           _4 = _1;
           StorageLive(_5);
--         StorageLive(_6);
+          StorageLive(_6);
 -         _6 = _4;
 -         _5 = opaque::<&str>(move _6) -> [return: bb2, unwind unreachable];
++         _6 = _1;
 +         _5 = opaque::<&str>(_1) -> [return: bb2, unwind unreachable];
       }
   
       bb2: {
--         StorageDead(_6);
+          StorageDead(_6);
           StorageDead(_5);
--         StorageLive(_7);
+          StorageLive(_7);
           StorageLive(_8);
-          StorageLive(_9);
+-         StorageLive(_9);
++         nop;
           StorageLive(_10);
           StorageLive(_11);
           _11 = &(*_1);
@@ -120,28 +123,37 @@
       bb3: {
           StorageDead(_11);
           _9 = &_10;
-          StorageLive(_12);
+-         StorageLive(_12);
++         nop;
           StorageLive(_13);
           StorageLive(_14);
-          _14 = &(*_4);
+-         _14 = &(*_4);
++         _14 = &(*_1);
           _13 = core::str::<impl str>::as_ptr(move _14) -> [return: bb4, unwind unreachable];
       }
   
       bb4: {
           StorageDead(_14);
           _12 = &_13;
-          _8 = (move _9, move _12);
-          StorageDead(_12);
-          StorageDead(_9);
+-         _8 = (move _9, move _12);
+-         StorageDead(_12);
+-         StorageDead(_9);
++         _8 = (_9, _12);
++         nop;
++         nop;
           StorageLive(_15);
-          _15 = (_8.0: &*const u8);
+-         _15 = (_8.0: &*const u8);
++         _15 = _9;
           StorageLive(_16);
-          _16 = (_8.1: &*const u8);
+-         _16 = (_8.1: &*const u8);
++         _16 = _12;
           StorageLive(_17);
           StorageLive(_18);
-          _18 = (*_15);
+-         _18 = (*_15);
++         _18 = (*_9);
           StorageLive(_19);
-          _19 = (*_16);
+-         _19 = (*_16);
++         _19 = (*_12);
           _17 = Eq(move _18, move _19);
           switchInt(move _17) -> [0: bb6, otherwise: bb5];
       }
@@ -149,22 +161,23 @@
       bb5: {
           StorageDead(_19);
           StorageDead(_18);
--         _7 = const ();
+          _7 = const ();
           StorageDead(_17);
           StorageDead(_16);
           StorageDead(_15);
           StorageDead(_13);
           StorageDead(_10);
           StorageDead(_8);
--         StorageDead(_7);
+          StorageDead(_7);
 -         StorageLive(_29);
++         nop;
           StorageLive(_30);
           _30 = &(*_1);
           _29 = move _30 as &[u8] (Transmute);
           StorageDead(_30);
           StorageLive(_31);
--         StorageLive(_32);
--         _32 = _29;
+          StorageLive(_32);
+          _32 = _29;
 -         _31 = opaque::<&[u8]>(move _32) -> [return: bb7, unwind unreachable];
 +         _31 = opaque::<&[u8]>(_29) -> [return: bb7, unwind unreachable];
       }
@@ -173,30 +186,38 @@
           StorageDead(_19);
           StorageDead(_18);
 -         StorageLive(_21);
-          _21 = core::panicking::AssertKind::Eq;
+-         _21 = core::panicking::AssertKind::Eq;
++         nop;
++         _21 = const core::panicking::AssertKind::Eq;
           StorageLive(_22);
--         StorageLive(_23);
+          StorageLive(_23);
 -         _23 = move _21;
++         _23 = const core::panicking::AssertKind::Eq;
           StorageLive(_24);
-          StorageLive(_25);
-          _25 = &(*_15);
+-         StorageLive(_25);
+-         _25 = &(*_15);
++         nop;
++         _25 = &(*_9);
           _24 = &(*_25);
           StorageLive(_26);
-          StorageLive(_27);
-          _27 = &(*_16);
+-         StorageLive(_27);
+-         _27 = &(*_16);
++         nop;
++         _27 = &(*_12);
           _26 = &(*_27);
           StorageLive(_28);
           _28 = Option::<Arguments<'_>>::None;
--         _22 = core::panicking::assert_failed::<*const u8, *const u8>(move _23, move _24, move _26, move _28) -> unwind unreachable;
-+         _22 = core::panicking::assert_failed::<*const u8, *const u8>(_21, move _24, move _26, move _28) -> unwind unreachable;
+-         _22 = assert_failed::<*const u8, *const u8>(move _23, move _24, move _26, move _28) -> unwind unreachable;
++         _22 = assert_failed::<*const u8, *const u8>(const core::panicking::AssertKind::Eq, move _24, move _26, move _28) -> unwind unreachable;
       }
   
       bb7: {
--         StorageDead(_32);
+          StorageDead(_32);
           StorageDead(_31);
--         StorageLive(_33);
+          StorageLive(_33);
           StorageLive(_34);
-          StorageLive(_35);
+-         StorageLive(_35);
++         nop;
           StorageLive(_36);
           StorageLive(_37);
           _37 = &(*_1);
@@ -206,7 +227,8 @@
       bb8: {
           StorageDead(_37);
           _35 = &_36;
-          StorageLive(_38);
+-         StorageLive(_38);
++         nop;
           StorageLive(_39);
           StorageLive(_40);
           _40 = &(*_29);
@@ -216,18 +238,25 @@
       bb9: {
           StorageDead(_40);
           _38 = &_39;
-          _34 = (move _35, move _38);
-          StorageDead(_38);
-          StorageDead(_35);
+-         _34 = (move _35, move _38);
+-         StorageDead(_38);
+-         StorageDead(_35);
++         _34 = (_35, _38);
++         nop;
++         nop;
           StorageLive(_41);
-          _41 = (_34.0: &*const u8);
+-         _41 = (_34.0: &*const u8);
++         _41 = _35;
           StorageLive(_42);
-          _42 = (_34.1: &*const u8);
+-         _42 = (_34.1: &*const u8);
++         _42 = _38;
           StorageLive(_43);
           StorageLive(_44);
-          _44 = (*_41);
+-         _44 = (*_41);
++         _44 = (*_35);
           StorageLive(_45);
-          _45 = (*_42);
+-         _45 = (*_42);
++         _45 = (*_38);
           _43 = Eq(move _44, move _45);
           switchInt(move _43) -> [0: bb11, otherwise: bb10];
       }
@@ -235,18 +264,20 @@
       bb10: {
           StorageDead(_45);
           StorageDead(_44);
--         _33 = const ();
+          _33 = const ();
           StorageDead(_43);
           StorageDead(_42);
           StorageDead(_41);
           StorageDead(_39);
           StorageDead(_36);
           StorageDead(_34);
--         StorageDead(_33);
+          StorageDead(_33);
           _0 = const ();
 -         StorageDead(_29);
++         nop;
           StorageDead(_4);
 -         StorageDead(_1);
++         nop;
           return;
       }
   
@@ -254,22 +285,29 @@
           StorageDead(_45);
           StorageDead(_44);
 -         StorageLive(_47);
-          _47 = core::panicking::AssertKind::Eq;
+-         _47 = core::panicking::AssertKind::Eq;
++         nop;
++         _47 = const core::panicking::AssertKind::Eq;
           StorageLive(_48);
--         StorageLive(_49);
+          StorageLive(_49);
 -         _49 = move _47;
++         _49 = const core::panicking::AssertKind::Eq;
           StorageLive(_50);
-          StorageLive(_51);
-          _51 = &(*_41);
+-         StorageLive(_51);
+-         _51 = &(*_41);
++         nop;
++         _51 = &(*_35);
           _50 = &(*_51);
           StorageLive(_52);
-          StorageLive(_53);
-          _53 = &(*_42);
+-         StorageLive(_53);
+-         _53 = &(*_42);
++         nop;
++         _53 = &(*_38);
           _52 = &(*_53);
           StorageLive(_54);
           _54 = Option::<Arguments<'_>>::None;
--         _48 = core::panicking::assert_failed::<*const u8, *const u8>(move _49, move _50, move _52, move _54) -> unwind unreachable;
-+         _48 = core::panicking::assert_failed::<*const u8, *const u8>(_47, move _50, move _52, move _54) -> unwind unreachable;
+-         _48 = assert_failed::<*const u8, *const u8>(move _49, move _50, move _52, move _54) -> unwind unreachable;
++         _48 = assert_failed::<*const u8, *const u8>(const core::panicking::AssertKind::Eq, move _50, move _52, move _54) -> unwind unreachable;
       }
   }
   

tests/mir-opt/gvn.slices.GVN.panic-unwind.diff

@@ -85,32 +85,35 @@
   
       bb0: {
 -         StorageLive(_1);
++         nop;
           _1 = const "my favourite slice";
           StorageLive(_2);
--         StorageLive(_3);
--         _3 = _1;
+          StorageLive(_3);
+          _3 = _1;
 -         _2 = opaque::<&str>(move _3) -> [return: bb1, unwind continue];
 +         _2 = opaque::<&str>(_1) -> [return: bb1, unwind continue];
       }
   
       bb1: {
--         StorageDead(_3);
+          StorageDead(_3);
           StorageDead(_2);
           StorageLive(_4);
           _4 = _1;
           StorageLive(_5);
--         StorageLive(_6);
+          StorageLive(_6);
 -         _6 = _4;
 -         _5 = opaque::<&str>(move _6) -> [return: bb2, unwind continue];
++         _6 = _1;
 +         _5 = opaque::<&str>(_1) -> [return: bb2, unwind continue];
       }
   
       bb2: {
--         StorageDead(_6);
+          StorageDead(_6);
           StorageDead(_5);
--         StorageLive(_7);
+          StorageLive(_7);
           StorageLive(_8);
-          StorageLive(_9);
+-         StorageLive(_9);
++         nop;
           StorageLive(_10);
           StorageLive(_11);
           _11 = &(*_1);
@@ -120,28 +123,37 @@
       bb3: {
           StorageDead(_11);
           _9 = &_10;
-          StorageLive(_12);
+-         StorageLive(_12);
++         nop;
           StorageLive(_13);
           StorageLive(_14);
-          _14 = &(*_4);
+-         _14 = &(*_4);
++         _14 = &(*_1);
           _13 = core::str::<impl str>::as_ptr(move _14) -> [return: bb4, unwind continue];
       }
   
       bb4: {
           StorageDead(_14);
           _12 = &_13;
-          _8 = (move _9, move _12);
-          StorageDead(_12);
-          StorageDead(_9);
+-         _8 = (move _9, move _12);
+-         StorageDead(_12);
+-         StorageDead(_9);
++         _8 = (_9, _12);
++         nop;
++         nop;
           StorageLive(_15);
-          _15 = (_8.0: &*const u8);
+-         _15 = (_8.0: &*const u8);
++         _15 = _9;
           StorageLive(_16);
-          _16 = (_8.1: &*const u8);
+-         _16 = (_8.1: &*const u8);
++         _16 = _12;
           StorageLive(_17);
           StorageLive(_18);
-          _18 = (*_15);
+-         _18 = (*_15);
++         _18 = (*_9);
           StorageLive(_19);
-          _19 = (*_16);
+-         _19 = (*_16);
++         _19 = (*_12);
           _17 = Eq(move _18, move _19);
           switchInt(move _17) -> [0: bb6, otherwise: bb5];
       }
@@ -149,22 +161,23 @@
       bb5: {
           StorageDead(_19);
           StorageDead(_18);
--         _7 = const ();
+          _7 = const ();
           StorageDead(_17);
           StorageDead(_16);
           StorageDead(_15);
           StorageDead(_13);
           StorageDead(_10);
           StorageDead(_8);
--         StorageDead(_7);
+          StorageDead(_7);
 -         StorageLive(_29);
++         nop;
           StorageLive(_30);
           _30 = &(*_1);
           _29 = move _30 as &[u8] (Transmute);
           StorageDead(_30);
           StorageLive(_31);
--         StorageLive(_32);
--         _32 = _29;
+          StorageLive(_32);
+          _32 = _29;
 -         _31 = opaque::<&[u8]>(move _32) -> [return: bb7, unwind continue];
 +         _31 = opaque::<&[u8]>(_29) -> [return: bb7, unwind continue];
       }
@@ -173,30 +186,38 @@
           StorageDead(_19);
           StorageDead(_18);
 -         StorageLive(_21);
-          _21 = core::panicking::AssertKind::Eq;
+-         _21 = core::panicking::AssertKind::Eq;
++         nop;
++         _21 = const core::panicking::AssertKind::Eq;
           StorageLive(_22);
--         StorageLive(_23);
+          StorageLive(_23);
 -         _23 = move _21;
++         _23 = const core::panicking::AssertKind::Eq;
           StorageLive(_24);
-          StorageLive(_25);
-          _25 = &(*_15);
+-         StorageLive(_25);
+-         _25 = &(*_15);
++         nop;
++         _25 = &(*_9);
           _24 = &(*_25);
           StorageLive(_26);
-          StorageLive(_27);
-          _27 = &(*_16);
+-         StorageLive(_27);
+-         _27 = &(*_16);
++         nop;
++         _27 = &(*_12);
           _26 = &(*_27);
           StorageLive(_28);
           _28 = Option::<Arguments<'_>>::None;
--         _22 = core::panicking::assert_failed::<*const u8, *const u8>(move _23, move _24, move _26, move _28) -> unwind continue;
-+         _22 = core::panicking::assert_failed::<*const u8, *const u8>(_21, move _24, move _26, move _28) -> unwind continue;
+-         _22 = assert_failed::<*const u8, *const u8>(move _23, move _24, move _26, move _28) -> unwind continue;
++         _22 = assert_failed::<*const u8, *const u8>(const core::panicking::AssertKind::Eq, move _24, move _26, move _28) -> unwind continue;
       }
   
       bb7: {
--         StorageDead(_32);
+          StorageDead(_32);
           StorageDead(_31);
--         StorageLive(_33);
+          StorageLive(_33);
           StorageLive(_34);
-          StorageLive(_35);
+-         StorageLive(_35);
++         nop;
           StorageLive(_36);
           StorageLive(_37);
           _37 = &(*_1);
@@ -206,7 +227,8 @@
       bb8: {
           StorageDead(_37);
           _35 = &_36;
-          StorageLive(_38);
+-         StorageLive(_38);
++         nop;
           StorageLive(_39);
           StorageLive(_40);
           _40 = &(*_29);
@@ -216,18 +238,25 @@
       bb9: {
           StorageDead(_40);
           _38 = &_39;
-          _34 = (move _35, move _38);
-          StorageDead(_38);
-          StorageDead(_35);
+-         _34 = (move _35, move _38);
+-         StorageDead(_38);
+-         StorageDead(_35);
++         _34 = (_35, _38);
++         nop;
++         nop;
           StorageLive(_41);
-          _41 = (_34.0: &*const u8);
+-         _41 = (_34.0: &*const u8);
++         _41 = _35;
           StorageLive(_42);
-          _42 = (_34.1: &*const u8);
+-         _42 = (_34.1: &*const u8);
++         _42 = _38;
           StorageLive(_43);
           StorageLive(_44);
-          _44 = (*_41);
+-         _44 = (*_41);
++         _44 = (*_35);
           StorageLive(_45);
-          _45 = (*_42);
+-         _45 = (*_42);
++         _45 = (*_38);
           _43 = Eq(move _44, move _45);
           switchInt(move _43) -> [0: bb11, otherwise: bb10];
       }
@@ -235,18 +264,20 @@
       bb10: {
           StorageDead(_45);
           StorageDead(_44);
--         _33 = const ();
+          _33 = const ();
           StorageDead(_43);
           StorageDead(_42);
           StorageDead(_41);
           StorageDead(_39);
           StorageDead(_36);
           StorageDead(_34);
--         StorageDead(_33);
+          StorageDead(_33);
           _0 = const ();
 -         StorageDead(_29);
++         nop;
           StorageDead(_4);
 -         StorageDead(_1);
++         nop;
           return;
       }
   
@@ -254,22 +285,29 @@
           StorageDead(_45);
           StorageDead(_44);
 -         StorageLive(_47);
-          _47 = core::panicking::AssertKind::Eq;
+-         _47 = core::panicking::AssertKind::Eq;
++         nop;
++         _47 = const core::panicking::AssertKind::Eq;
           StorageLive(_48);
--         StorageLive(_49);
+          StorageLive(_49);
 -         _49 = move _47;
++         _49 = const core::panicking::AssertKind::Eq;
           StorageLive(_50);
-          StorageLive(_51);
-          _51 = &(*_41);
+-         StorageLive(_51);
+-         _51 = &(*_41);
++         nop;
++         _51 = &(*_35);
           _50 = &(*_51);
           StorageLive(_52);
-          StorageLive(_53);
-          _53 = &(*_42);
+-         StorageLive(_53);
+-         _53 = &(*_42);
++         nop;
++         _53 = &(*_38);
           _52 = &(*_53);
           StorageLive(_54);
           _54 = Option::<Arguments<'_>>::None;
--         _48 = core::panicking::assert_failed::<*const u8, *const u8>(move _49, move _50, move _52, move _54) -> unwind continue;
-+         _48 = core::panicking::assert_failed::<*const u8, *const u8>(_47, move _50, move _52, move _54) -> unwind continue;
+-         _48 = assert_failed::<*const u8, *const u8>(move _49, move _50, move _52, move _54) -> unwind continue;
++         _48 = assert_failed::<*const u8, *const u8>(const core::panicking::AssertKind::Eq, move _50, move _52, move _54) -> unwind continue;
       }
   }
   

tests/mir-opt/gvn.wrap_unwrap.GVN.panic-abort.diff

@@ -15,13 +15,15 @@
   
       bb0: {
           StorageLive(_2);
--         StorageLive(_3);
--         _3 = _1;
+          StorageLive(_3);
+          _3 = _1;
 -         _2 = Option::<T>::Some(move _3);
--         StorageDead(_3);
 +         _2 = Option::<T>::Some(_1);
-          _4 = discriminant(_2);
-          switchInt(move _4) -> [0: bb1, 1: bb3, otherwise: bb2];
+          StorageDead(_3);
+-         _4 = discriminant(_2);
+-         switchInt(move _4) -> [0: bb1, 1: bb3, otherwise: bb2];
++         _4 = const 1_isize;
++         switchInt(const 1_isize) -> [0: bb1, 1: bb3, otherwise: bb2];
       }
   
       bb1: {
@@ -34,10 +36,12 @@
       }
   
       bb3: {
--         StorageLive(_5);
-          _5 = ((_2 as Some).0: T);
-          _0 = _5;
--         StorageDead(_5);
+          StorageLive(_5);
+-         _5 = ((_2 as Some).0: T);
+-         _0 = _5;
++         _5 = _1;
++         _0 = _1;
+          StorageDead(_5);
           StorageDead(_2);
           return;
       }

tests/mir-opt/gvn.wrap_unwrap.GVN.panic-unwind.diff

@@ -15,13 +15,15 @@
   
       bb0: {
           StorageLive(_2);
--         StorageLive(_3);
--         _3 = _1;
+          StorageLive(_3);
+          _3 = _1;
 -         _2 = Option::<T>::Some(move _3);
--         StorageDead(_3);
 +         _2 = Option::<T>::Some(_1);
-          _4 = discriminant(_2);
-          switchInt(move _4) -> [0: bb1, 1: bb3, otherwise: bb2];
+          StorageDead(_3);
+-         _4 = discriminant(_2);
+-         switchInt(move _4) -> [0: bb1, 1: bb3, otherwise: bb2];
++         _4 = const 1_isize;
++         switchInt(const 1_isize) -> [0: bb1, 1: bb3, otherwise: bb2];
       }
   
       bb1: {
@@ -34,10 +36,12 @@
       }
   
       bb3: {
--         StorageLive(_5);
-          _5 = ((_2 as Some).0: T);
-          _0 = _5;
--         StorageDead(_5);
+          StorageLive(_5);
+-         _5 = ((_2 as Some).0: T);
+-         _0 = _5;
++         _5 = _1;
++         _0 = _1;
+          StorageDead(_5);
           StorageDead(_2);
           return;
       }

tests/mir-opt/issue_76432.test.SimplifyComparisonIntegral.panic-abort.diff

@@ -7,22 +7,18 @@
       let _2: &[T];
       let mut _3: &[T; 3];
       let _4: [T; 3];
-      let mut _5: T;
-      let mut _6: T;
-      let mut _7: T;
-      let mut _8: usize;
-      let mut _9: usize;
-      let mut _10: bool;
-      let mut _14: !;
+      let mut _5: usize;
+      let mut _6: bool;
+      let mut _10: !;
       scope 1 {
           debug v => _2;
-          let _11: &T;
-          let _12: &T;
-          let _13: &T;
+          let _7: &T;
+          let _8: &T;
+          let _9: &T;
           scope 2 {
-              debug v1 => _11;
-              debug v2 => _12;
-              debug v3 => _13;
+              debug v1 => _7;
+              debug v2 => _8;
+              debug v3 => _9;
           }
       }
   
@@ -33,26 +29,25 @@
           _3 = &_4;
           _2 = move _3 as &[T] (PointerCoercion(Unsize));
           StorageDead(_3);
-          _8 = const 3_usize;
-          _9 = const 3_usize;
-          _10 = const true;
+          _5 = const 3_usize;
+          _6 = const true;
           goto -> bb2;
       }
   
       bb1: {
-          _14 = core::panicking::panic(const "internal error: entered unreachable code") -> unwind unreachable;
+          _10 = core::panicking::panic(const "internal error: entered unreachable code") -> unwind unreachable;
       }
   
       bb2: {
-          StorageLive(_11);
-          _11 = &(*_2)[0 of 3];
-          StorageLive(_12);
-          _12 = &(*_2)[1 of 3];
-          StorageLive(_13);
-          _13 = &(*_2)[2 of 3];
-          StorageDead(_13);
-          StorageDead(_12);
-          StorageDead(_11);
+          StorageLive(_7);
+          _7 = &(*_2)[0 of 3];
+          StorageLive(_8);
+          _8 = &(*_2)[1 of 3];
+          StorageLive(_9);
+          _9 = &(*_2)[2 of 3];
+          StorageDead(_9);
+          StorageDead(_8);
+          StorageDead(_7);
           StorageDead(_4);
           return;
       }

tests/mir-opt/issue_76432.test.SimplifyComparisonIntegral.panic-unwind.diff

@@ -7,22 +7,18 @@
       let _2: &[T];
       let mut _3: &[T; 3];
       let _4: [T; 3];
-      let mut _5: T;
-      let mut _6: T;
-      let mut _7: T;
-      let mut _8: usize;
-      let mut _9: usize;
-      let mut _10: bool;
-      let mut _14: !;
+      let mut _5: usize;
+      let mut _6: bool;
+      let mut _10: !;
       scope 1 {
           debug v => _2;
-          let _11: &T;
-          let _12: &T;
-          let _13: &T;
+          let _7: &T;
+          let _8: &T;
+          let _9: &T;
           scope 2 {
-              debug v1 => _11;
-              debug v2 => _12;
-              debug v3 => _13;
+              debug v1 => _7;
+              debug v2 => _8;
+              debug v3 => _9;
           }
       }
   
@@ -33,26 +29,25 @@
           _3 = &_4;
           _2 = move _3 as &[T] (PointerCoercion(Unsize));
           StorageDead(_3);
-          _8 = const 3_usize;
-          _9 = const 3_usize;
-          _10 = const true;
+          _5 = const 3_usize;
+          _6 = const true;
           goto -> bb2;
       }
   
       bb1: {
-          _14 = core::panicking::panic(const "internal error: entered unreachable code") -> unwind continue;
+          _10 = core::panicking::panic(const "internal error: entered unreachable code") -> unwind continue;
       }
   
       bb2: {
-          StorageLive(_11);
-          _11 = &(*_2)[0 of 3];
-          StorageLive(_12);
-          _12 = &(*_2)[1 of 3];
-          StorageLive(_13);
-          _13 = &(*_2)[2 of 3];
-          StorageDead(_13);
-          StorageDead(_12);
-          StorageDead(_11);
+          StorageLive(_7);
+          _7 = &(*_2)[0 of 3];
+          StorageLive(_8);
+          _8 = &(*_2)[1 of 3];
+          StorageLive(_9);
+          _9 = &(*_2)[2 of 3];
+          StorageDead(_9);
+          StorageDead(_8);
+          StorageDead(_7);
           StorageDead(_4);
           return;
       }

tests/mir-opt/simplify_if.main.SimplifyConstCondition-after-const-prop.panic-abort.diff

@@ -3,18 +3,15 @@
   
   fn main() -> () {
       let mut _0: ();
-      let mut _1: bool;
-      let _2: ();
+      let _1: ();
   
       bb0: {
-          StorageLive(_1);
-          _1 = const false;
 -         switchInt(const false) -> [0: bb3, otherwise: bb1];
 +         goto -> bb3;
       }
   
       bb1: {
-          _2 = noop() -> [return: bb2, unwind unreachable];
+          _1 = noop() -> [return: bb2, unwind unreachable];
       }
   
       bb2: {
@@ -26,7 +23,6 @@
       }
   
       bb4: {
-          StorageDead(_1);
           return;
       }
   }

tests/mir-opt/simplify_if.main.SimplifyConstCondition-after-const-prop.panic-unwind.diff

@@ -3,18 +3,15 @@
   
   fn main() -> () {
       let mut _0: ();
-      let mut _1: bool;
-      let _2: ();
+      let _1: ();
   
       bb0: {
-          StorageLive(_1);
-          _1 = const false;
 -         switchInt(const false) -> [0: bb3, otherwise: bb1];
 +         goto -> bb3;
       }
   
       bb1: {
-          _2 = noop() -> [return: bb2, unwind continue];
+          _1 = noop() -> [return: bb2, unwind continue];
       }
   
       bb2: {
@@ -26,7 +23,6 @@
       }
   
       bb4: {
-          StorageDead(_1);
           return;
       }
   }