Rollup merge of #135748 - compiler-errors:len-2, r=RalfJung,oli-obk

Lower index bounds checking to `PtrMetadata`, this time with the right fake borrow semantics 😸

Change `Rvalue::RawRef` to take a `RawRefKind` instead of just a `Mutability`. Then introduce `RawRefKind::FakeForPtrMetadata` and use that for lowering index bounds checking to a `PtrMetadata`. This new `RawRefKind::FakeForPtrMetadata` acts like a shallow fake borrow in borrowck, which mimics the semantics of the old `Rvalue::Len` operation we're replacing.

We can then use this `RawRefKind` instead of using a span desugaring hack in CTFE.

cc ``@scottmcm`` ``@RalfJung``

compiler/rustc_borrowck/src/lib.rs

@@ -1284,15 +1284,18 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
                 );
             }
 
-            &Rvalue::RawPtr(mutability, place) => {
-                let access_kind = match mutability {
-                    Mutability::Mut => (
+            &Rvalue::RawPtr(kind, place) => {
+                let access_kind = match kind {
+                    RawPtrKind::Mut => (
                         Deep,
                         Write(WriteKind::MutableBorrow(BorrowKind::Mut {
                             kind: MutBorrowKind::Default,
                         })),
                     ),
-                    Mutability::Not => (Deep, Read(ReadKind::Borrow(BorrowKind::Shared))),
+                    RawPtrKind::Const => (Deep, Read(ReadKind::Borrow(BorrowKind::Shared))),
+                    RawPtrKind::FakeForPtrMetadata => {
+                        (Shallow(Some(ArtificialField::ArrayLength)), Read(ReadKind::Copy))
+                    }
                 };
 
                 self.access_place(

compiler/rustc_borrowck/src/polonius/legacy/loan_invalidations.rs

@@ -3,11 +3,7 @@ use std::ops::ControlFlow;
 use rustc_data_structures::graph::dominators::Dominators;
 use rustc_middle::bug;
 use rustc_middle::mir::visit::Visitor;
-use rustc_middle::mir::{
-    self, BasicBlock, Body, BorrowKind, FakeBorrowKind, InlineAsmOperand, Location, Mutability,
-    NonDivergingIntrinsic, Operand, Place, Rvalue, Statement, StatementKind, Terminator,
-    TerminatorKind,
-};
+use rustc_middle::mir::*;
 use rustc_middle::ty::TyCtxt;
 use tracing::debug;
 
@@ -60,7 +56,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LoanInvalidationsGenerator<'a, 'tcx> {
             StatementKind::Intrinsic(box NonDivergingIntrinsic::Assume(op)) => {
                 self.consume_operand(location, op);
             }
-            StatementKind::Intrinsic(box NonDivergingIntrinsic::CopyNonOverlapping(mir::CopyNonOverlapping {
+            StatementKind::Intrinsic(box NonDivergingIntrinsic::CopyNonOverlapping(CopyNonOverlapping {
                 src,
                 dst,
                 count,
@@ -273,15 +269,18 @@ impl<'a, 'tcx> LoanInvalidationsGenerator<'a, 'tcx> {
                 self.access_place(location, place, access_kind, LocalMutationIsAllowed::No);
             }
 
-            &Rvalue::RawPtr(mutability, place) => {
-                let access_kind = match mutability {
-                    Mutability::Mut => (
+            &Rvalue::RawPtr(kind, place) => {
+                let access_kind = match kind {
+                    RawPtrKind::Mut => (
                         Deep,
                         Write(WriteKind::MutableBorrow(BorrowKind::Mut {
-                            kind: mir::MutBorrowKind::Default,
+                            kind: MutBorrowKind::Default,
                         })),
                     ),
-                    Mutability::Not => (Deep, Read(ReadKind::Borrow(BorrowKind::Shared))),
+                    RawPtrKind::Const => (Deep, Read(ReadKind::Borrow(BorrowKind::Shared))),
+                    RawPtrKind::FakeForPtrMetadata => {
+                        (Shallow(Some(ArtificialField::ArrayLength)), Read(ReadKind::Copy))
+                    }
                 };
 
                 self.access_place(location, place, access_kind, LocalMutationIsAllowed::No);

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -349,8 +349,8 @@ impl<'a, 'b, 'tcx> Visitor<'tcx> for TypeVerifier<'a, 'b, 'tcx> {
             let tcx = self.tcx();
             let maybe_uneval = match constant.const_ {
                 Const::Ty(_, ct) => match ct.kind() {
-                    ty::ConstKind::Unevaluated(_) => {
-                        bug!("should not encounter unevaluated Const::Ty here, got {:?}", ct)
+                    ty::ConstKind::Unevaluated(uv) => {
+                        Some(UnevaluatedConst { def: uv.def, args: uv.args, promoted: None })
                     }
                     _ => None,
                 },

compiler/rustc_codegen_ssa/src/mir/rvalue.rs

@@ -612,9 +612,10 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             mir::Rvalue::CopyForDeref(place) => {
                 self.codegen_operand(bx, &mir::Operand::Copy(place))
             }
-            mir::Rvalue::RawPtr(mutability, place) => {
-                let mk_ptr =
-                    move |tcx: TyCtxt<'tcx>, ty: Ty<'tcx>| Ty::new_ptr(tcx, ty, mutability);
+            mir::Rvalue::RawPtr(kind, place) => {
+                let mk_ptr = move |tcx: TyCtxt<'tcx>, ty: Ty<'tcx>| {
+                    Ty::new_ptr(tcx, ty, kind.to_mutbl_lossy())
+                };
                 self.codegen_place_to_pointer(bx, place, mk_ptr)
             }
 

compiler/rustc_const_eval/src/check_consts/check.rs

@@ -518,7 +518,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
             }
 
             Rvalue::Ref(_, BorrowKind::Mut { .. }, place)
-            | Rvalue::RawPtr(Mutability::Mut, place) => {
+            | Rvalue::RawPtr(RawPtrKind::Mut, place) => {
                 // Inside mutable statics, we allow arbitrary mutable references.
                 // We've allowed `static mut FOO = &mut [elements];` for a long time (the exact
                 // reasons why are lost to history), and there is no reason to restrict that to
@@ -536,7 +536,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
             }
 
             Rvalue::Ref(_, BorrowKind::Shared | BorrowKind::Fake(_), place)
-            | Rvalue::RawPtr(Mutability::Not, place) => {
+            | Rvalue::RawPtr(RawPtrKind::Const, place) => {
                 let borrowed_place_has_mut_interior = qualifs::in_place::<HasMutInterior, _>(
                     self.ccx,
                     &mut |local| self.qualifs.has_mut_interior(self.ccx, local, location),
@@ -548,6 +548,12 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                 }
             }
 
+            Rvalue::RawPtr(RawPtrKind::FakeForPtrMetadata, place) => {
+                // These are only inserted for slice length, so the place must already be indirect.
+                // This implies we do not have to worry about whether the borrow escapes.
+                assert!(place.is_indirect(), "fake borrows are always indirect");
+            }
+
             Rvalue::Cast(
                 CastKind::PointerCoercion(
                     PointerCoercion::MutToConstPointer
@@ -586,12 +592,23 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
             ) => {}
             Rvalue::ShallowInitBox(_, _) => {}
 
-            Rvalue::UnaryOp(_, operand) => {
+            Rvalue::UnaryOp(op, operand) => {
                 let ty = operand.ty(self.body, self.tcx);
-                if is_int_bool_float_or_char(ty) {
-                    // Int, bool, float, and char operations are fine.
-                } else {
-                    span_bug!(self.span, "non-primitive type in `Rvalue::UnaryOp`: {:?}", ty);
+                match op {
+                    UnOp::Not | UnOp::Neg => {
+                        if is_int_bool_float_or_char(ty) {
+                            // Int, bool, float, and char operations are fine.
+                        } else {
+                            span_bug!(
+                                self.span,
+                                "non-primitive type in `Rvalue::UnaryOp{op:?}`: {ty:?}",
+                            );
+                        }
+                    }
+                    UnOp::PtrMetadata => {
+                        // Getting the metadata from a pointer is always const.
+                        // We already validated the type is valid in the validator.
+                    }
                 }
             }
 

compiler/rustc_const_eval/src/interpret/step.rs

@@ -237,7 +237,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 self.write_immediate(*val, &dest)?;
             }
 
-            RawPtr(_, place) => {
+            RawPtr(kind, place) => {
                 // Figure out whether this is an addr_of of an already raw place.
                 let place_base_raw = if place.is_indirect_first_projection() {
                     let ty = self.frame().body.local_decls[place.local].ty;
@@ -250,8 +250,9 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 let src = self.eval_place(place)?;
                 let place = self.force_allocation(&src)?;
                 let mut val = ImmTy::from_immediate(place.to_ref(self), dest.layout);
-                if !place_base_raw {
-                    // If this was not already raw, it needs retagging.
+                if !place_base_raw && !kind.is_fake() {
+                    // If this was not already raw, it needs retagging -- except for "fake"
+                    // raw borrows whose defining property is that they do not get retagged.
                     val = M::retag_ptr_value(self, mir::RetagKind::Raw, &val)?;
                 }
                 self.write_immediate(*val, &dest)?;

compiler/rustc_middle/src/mir/syntax.rs

@@ -180,6 +180,59 @@ pub enum BorrowKind {
     Mut { kind: MutBorrowKind },
 }
 
+#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, TyEncodable, TyDecodable)]
+#[derive(Hash, HashStable)]
+pub enum RawPtrKind {
+    Mut,
+    Const,
+    /// Creates a raw pointer to a place that will only be used to access its metadata,
+    /// not the data behind the pointer. Note that this limitation is *not* enforced
+    /// by the validator.
+    ///
+    /// The borrow checker allows overlap of these raw pointers with references to the
+    /// data. This is sound even if the pointer is "misused" since any such use is anyway
+    /// unsafe. In terms of the operational semantics (i.e., Miri), this is equivalent
+    /// to `RawPtrKind::Mut`, but will never incur a retag.
+    FakeForPtrMetadata,
+}
+
+impl From<Mutability> for RawPtrKind {
+    fn from(other: Mutability) -> Self {
+        match other {
+            Mutability::Mut => RawPtrKind::Mut,
+            Mutability::Not => RawPtrKind::Const,
+        }
+    }
+}
+
+impl RawPtrKind {
+    pub fn is_fake(self) -> bool {
+        match self {
+            RawPtrKind::Mut | RawPtrKind::Const => false,
+            RawPtrKind::FakeForPtrMetadata => true,
+        }
+    }
+
+    pub fn to_mutbl_lossy(self) -> Mutability {
+        match self {
+            RawPtrKind::Mut => Mutability::Mut,
+            RawPtrKind::Const => Mutability::Not,
+
+            // We have no type corresponding to a fake borrow, so use
+            // `*const` as an approximation.
+            RawPtrKind::FakeForPtrMetadata => Mutability::Not,
+        }
+    }
+
+    pub fn ptr_str(self) -> &'static str {
+        match self {
+            RawPtrKind::Mut => "mut",
+            RawPtrKind::Const => "const",
+            RawPtrKind::FakeForPtrMetadata => "const (fake)",
+        }
+    }
+}
+
 #[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, TyEncodable, TyDecodable)]
 #[derive(Hash, HashStable)]
 pub enum MutBorrowKind {
@@ -1356,7 +1409,7 @@ pub enum Rvalue<'tcx> {
     ///
     /// Like with references, the semantics of this operation are heavily dependent on the aliasing
     /// model.
-    RawPtr(Mutability, Place<'tcx>),
+    RawPtr(RawPtrKind, Place<'tcx>),
 
     /// Yields the length of the place, as a `usize`.
     ///

compiler/rustc_middle/src/mir/tcx.rs

@@ -206,9 +206,9 @@ impl<'tcx> Rvalue<'tcx> {
                 let place_ty = place.ty(local_decls, tcx).ty;
                 Ty::new_ref(tcx, reg, place_ty, bk.to_mutbl_lossy())
             }
-            Rvalue::RawPtr(mutability, ref place) => {
+            Rvalue::RawPtr(kind, ref place) => {
                 let place_ty = place.ty(local_decls, tcx).ty;
-                Ty::new_ptr(tcx, place_ty, mutability)
+                Ty::new_ptr(tcx, place_ty, kind.to_mutbl_lossy())
             }
             Rvalue::Len(..) => tcx.types.usize,
             Rvalue::Cast(.., ty) => ty,

compiler/rustc_middle/src/mir/type_foldable.rs

@@ -15,6 +15,7 @@ TrivialTypeTraversalImpls! {
     SourceScopeLocalData,
     UserTypeAnnotationIndex,
     BorrowKind,
+    RawPtrKind,
     CastKind,
     BasicBlock,
     SwitchTargets,

compiler/rustc_middle/src/mir/visit.rs

@@ -685,12 +685,15 @@ macro_rules! make_mir_visitor {
 
                     Rvalue::RawPtr(m, path) => {
                         let ctx = match m {
-                            Mutability::Mut => PlaceContext::MutatingUse(
+                            RawPtrKind::Mut => PlaceContext::MutatingUse(
                                 MutatingUseContext::RawBorrow
                             ),
-                            Mutability::Not => PlaceContext::NonMutatingUse(
+                            RawPtrKind::Const => PlaceContext::NonMutatingUse(
                                 NonMutatingUseContext::RawBorrow
                             ),
+                            RawPtrKind::FakeForPtrMetadata => PlaceContext::NonMutatingUse(
+                                NonMutatingUseContext::Inspect
+                            ),
                         };
                         self.visit_place(path, ctx, location);
                     }

compiler/rustc_mir_build/src/builder/custom/parse/instruction.rs

@@ -253,7 +253,7 @@ impl<'a, 'tcx> ParseCtxt<'a, 'tcx> {
                 Rvalue::Ref(self.tcx.lifetimes.re_erased, *borrow_kind, self.parse_place(*arg)?)
             ),
             ExprKind::RawBorrow { mutability, arg } => Ok(
-                Rvalue::RawPtr(*mutability, self.parse_place(*arg)?)
+                Rvalue::RawPtr((*mutability).into(), self.parse_place(*arg)?)
             ),
             ExprKind::Binary { op, lhs, rhs } =>  Ok(
                 Rvalue::BinaryOp(*op, Box::new((self.parse_operand(*lhs)?, self.parse_operand(*rhs)?)))

compiler/rustc_mir_build/src/builder/expr/as_place.rs

@@ -630,6 +630,69 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         block.and(base_place.index(idx))
     }
 
+    /// Given a place that's either an array or a slice, returns an operand
+    /// with the length of the array/slice.
+    ///
+    /// For arrays it'll be `Operand::Constant` with the actual length;
+    /// For slices it'll be `Operand::Move` of a local using `PtrMetadata`.
+    fn len_of_slice_or_array(
+        &mut self,
+        block: BasicBlock,
+        place: Place<'tcx>,
+        span: Span,
+        source_info: SourceInfo,
+    ) -> Operand<'tcx> {
+        let place_ty = place.ty(&self.local_decls, self.tcx).ty;
+        match place_ty.kind() {
+            ty::Array(_elem_ty, len_const) => {
+                // We know how long an array is, so just use that as a constant
+                // directly -- no locals needed. We do need one statement so
+                // that borrow- and initialization-checking consider it used,
+                // though. FIXME: Do we really *need* to count this as a use?
+                // Could partial array tracking work off something else instead?
+                self.cfg.push_fake_read(block, source_info, FakeReadCause::ForIndex, place);
+                let const_ = Const::Ty(self.tcx.types.usize, *len_const);
+                Operand::Constant(Box::new(ConstOperand { span, user_ty: None, const_ }))
+            }
+            ty::Slice(_elem_ty) => {
+                let ptr_or_ref = if let [PlaceElem::Deref] = place.projection[..]
+                    && let local_ty = self.local_decls[place.local].ty
+                    && local_ty.is_trivially_pure_clone_copy()
+                {
+                    // It's extremely common that we have something that can be
+                    // directly passed to `PtrMetadata`, so avoid an unnecessary
+                    // temporary and statement in those cases. Note that we can
+                    // only do that for `Copy` types -- not `&mut [_]` -- because
+                    // the MIR we're building here needs to pass NLL later.
+                    Operand::Copy(Place::from(place.local))
+                } else {
+                    let ptr_ty = Ty::new_imm_ptr(self.tcx, place_ty);
+                    let slice_ptr = self.temp(ptr_ty, span);
+                    self.cfg.push_assign(
+                        block,
+                        source_info,
+                        slice_ptr,
+                        Rvalue::RawPtr(RawPtrKind::FakeForPtrMetadata, place),
+                    );
+                    Operand::Move(slice_ptr)
+                };
+
+                let len = self.temp(self.tcx.types.usize, span);
+                self.cfg.push_assign(
+                    block,
+                    source_info,
+                    len,
+                    Rvalue::UnaryOp(UnOp::PtrMetadata, ptr_or_ref),
+                );
+
+                Operand::Move(len)
+            }
+            _ => {
+                span_bug!(span, "len called on place of type {place_ty:?}")
+            }
+        }
+    }
+
     fn bounds_check(
         &mut self,
         block: BasicBlock,
@@ -638,25 +701,25 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         expr_span: Span,
         source_info: SourceInfo,
     ) -> BasicBlock {
-        let usize_ty = self.tcx.types.usize;
-        let bool_ty = self.tcx.types.bool;
-        // bounds check:
-        let len = self.temp(usize_ty, expr_span);
-        let lt = self.temp(bool_ty, expr_span);
+        let slice = slice.to_place(self);
 
         // len = len(slice)
-        self.cfg.push_assign(block, source_info, len, Rvalue::Len(slice.to_place(self)));
+        let len = self.len_of_slice_or_array(block, slice, expr_span, source_info);
+
         // lt = idx < len
+        let bool_ty = self.tcx.types.bool;
+        let lt = self.temp(bool_ty, expr_span);
         self.cfg.push_assign(
             block,
             source_info,
             lt,
             Rvalue::BinaryOp(
                 BinOp::Lt,
-                Box::new((Operand::Copy(Place::from(index)), Operand::Copy(len))),
+                Box::new((Operand::Copy(Place::from(index)), len.to_copy())),
             ),
         );
-        let msg = BoundsCheck { len: Operand::Move(len), index: Operand::Copy(Place::from(index)) };
+        let msg = BoundsCheck { len, index: Operand::Copy(Place::from(index)) };
+
         // assert!(lt, "...")
         self.assert(block, Operand::Move(lt), true, msg, expr_span)
     }

compiler/rustc_mir_build/src/builder/expr/into.rs

@@ -303,7 +303,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     hir::Mutability::Not => this.as_read_only_place(block, arg),
                     hir::Mutability::Mut => this.as_place(block, arg),
                 };
-                let address_of = Rvalue::RawPtr(mutability, unpack!(block = place));
+                let address_of = Rvalue::RawPtr(mutability.into(), unpack!(block = place));
                 this.cfg.push_assign(block, source_info, destination, address_of);
                 block.unit()
             }

compiler/rustc_mir_dataflow/src/elaborate_drops.rs

@@ -700,7 +700,7 @@ where
             statements: vec![
                 self.assign(
                     ptr,
-                    Rvalue::RawPtr(Mutability::Mut, tcx.mk_place_index(self.place, cur)),
+                    Rvalue::RawPtr(RawPtrKind::Mut, tcx.mk_place_index(self.place, cur)),
                 ),
                 self.assign(
                     cur.into(),
@@ -816,7 +816,7 @@ where
 
         let mut delegate_block = BasicBlockData {
             statements: vec![
-                self.assign(Place::from(array_ptr), Rvalue::RawPtr(Mutability::Mut, self.place)),
+                self.assign(Place::from(array_ptr), Rvalue::RawPtr(RawPtrKind::Mut, self.place)),
                 self.assign(
                     Place::from(slice_ptr),
                     Rvalue::Cast(

compiler/rustc_mir_transform/src/gvn.rs

@@ -192,7 +192,7 @@ enum AggregateTy<'tcx> {
 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
 enum AddressKind {
     Ref(BorrowKind),
-    Address(Mutability),
+    Address(RawPtrKind),
 }
 
 #[derive(Debug, PartialEq, Eq, Hash)]
@@ -504,7 +504,9 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
                         mplace.layout.ty,
                         bk.to_mutbl_lossy(),
                     ),
-                    AddressKind::Address(mutbl) => Ty::new_ptr(self.tcx, mplace.layout.ty, mutbl),
+                    AddressKind::Address(mutbl) => {
+                        Ty::new_ptr(self.tcx, mplace.layout.ty, mutbl.to_mutbl_lossy())
+                    }
                 };
                 let layout = self.ecx.layout_of(ty).ok()?;
                 ImmTy::from_immediate(pointer, layout).into()

compiler/rustc_mir_transform/src/instsimplify.rs

@@ -46,7 +46,6 @@ impl<'tcx> crate::MirPass<'tcx> for InstSimplify {
                         }
                         ctx.simplify_bool_cmp(rvalue);
                         ctx.simplify_ref_deref(rvalue);
-                        ctx.simplify_len(rvalue);
                         ctx.simplify_ptr_aggregate(rvalue);
                         ctx.simplify_cast(rvalue);
                         ctx.simplify_repeated_aggregate(rvalue);
@@ -166,18 +165,6 @@ impl<'tcx> InstSimplifyContext<'_, 'tcx> {
         }
     }
 
-    /// Transform `Len([_; N])` ==> `N`.
-    fn simplify_len(&self, rvalue: &mut Rvalue<'tcx>) {
-        if let Rvalue::Len(ref place) = *rvalue {
-            let place_ty = place.ty(self.local_decls, self.tcx).ty;
-            if let ty::Array(_, len) = *place_ty.kind() {
-                let const_ = Const::Ty(self.tcx.types.usize, len);
-                let constant = ConstOperand { span: DUMMY_SP, const_, user_ty: None };
-                *rvalue = Rvalue::Use(Operand::Constant(Box::new(constant)));
-            }
-        }
-    }
-
     /// Transform `Aggregate(RawPtr, [p, ()])` ==> `Cast(PtrToPtr, p)`.
     fn simplify_ptr_aggregate(&self, rvalue: &mut Rvalue<'tcx>) {
         if let Rvalue::Aggregate(box AggregateKind::RawPtr(pointee_ty, mutability), fields) = rvalue

compiler/rustc_mir_transform/src/large_enums.rs

@@ -125,7 +125,7 @@ impl<'tcx> crate::MirPass<'tcx> for EnumSizeOpt {
                     source_info,
                     kind: StatementKind::Assign(Box::new((
                         dst,
-                        Rvalue::RawPtr(Mutability::Mut, *lhs),
+                        Rvalue::RawPtr(RawPtrKind::Mut, *lhs),
                     ))),
                 };
 
@@ -146,7 +146,7 @@ impl<'tcx> crate::MirPass<'tcx> for EnumSizeOpt {
                     source_info,
                     kind: StatementKind::Assign(Box::new((
                         src,
-                        Rvalue::RawPtr(Mutability::Not, *rhs),
+                        Rvalue::RawPtr(RawPtrKind::Const, *rhs),
                     ))),
                 };
 

compiler/rustc_mir_transform/src/shim/async_destructor_ctor.rs

@@ -2,17 +2,11 @@ use std::iter;
 
 use itertools::Itertools;
 use rustc_abi::{FieldIdx, VariantIdx};
-use rustc_ast::Mutability;
 use rustc_const_eval::interpret;
 use rustc_hir::def_id::DefId;
 use rustc_hir::lang_items::LangItem;
 use rustc_index::{Idx, IndexVec};
-use rustc_middle::mir::{
-    BasicBlock, BasicBlockData, Body, CallSource, CastKind, CoercionSource, Const, ConstOperand,
-    ConstValue, Local, LocalDecl, MirSource, Operand, Place, PlaceElem, RETURN_PLACE, Rvalue,
-    SourceInfo, Statement, StatementKind, Terminator, TerminatorKind, UnwindAction,
-    UnwindTerminateReason,
-};
+use rustc_middle::mir::*;
 use rustc_middle::ty::adjustment::PointerCoercion;
 use rustc_middle::ty::util::{AsyncDropGlueMorphology, Discr};
 use rustc_middle::ty::{self, Ty, TyCtxt};
@@ -345,7 +339,7 @@ impl<'tcx> AsyncDestructorCtorShimBuilder<'tcx> {
                 .tcx
                 .mk_place_elems(&[PlaceElem::Deref, PlaceElem::Field(field, field_ty)]),
         };
-        self.put_temp_rvalue(Rvalue::RawPtr(Mutability::Mut, place))
+        self.put_temp_rvalue(Rvalue::RawPtr(RawPtrKind::Mut, place))
     }
 
     /// If given Self is an enum puts `to_drop: *mut FieldTy` on top of
@@ -365,7 +359,7 @@ impl<'tcx> AsyncDestructorCtorShimBuilder<'tcx> {
                 PlaceElem::Field(field, field_ty),
             ]),
         };
-        self.put_temp_rvalue(Rvalue::RawPtr(Mutability::Mut, place))
+        self.put_temp_rvalue(Rvalue::RawPtr(RawPtrKind::Mut, place))
     }
 
     /// If given Self is an enum puts `to_drop: *mut FieldTy` on top of

compiler/rustc_mir_transform/src/validate.rs

@@ -1128,14 +1128,6 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                         );
                     }
                     UnOp::PtrMetadata => {
-                        if !matches!(self.body.phase, MirPhase::Runtime(_)) {
-                            // It would probably be fine to support this in earlier phases, but at
-                            // the time of writing it's only ever introduced from intrinsic
-                            // lowering or other runtime-phase optimization passes, so earlier
-                            // things can just `bug!` on it.
-                            self.fail(location, "PtrMetadata should be in runtime MIR only");
-                        }
-
                         check_kinds!(
                             a,
                             "Cannot PtrMetadata non-pointer non-reference type {:?}",

compiler/rustc_smir/src/rustc_smir/convert/mir.rs

@@ -232,6 +232,18 @@ impl<'tcx> Stable<'tcx> for mir::Mutability {
     }
 }
 
+impl<'tcx> Stable<'tcx> for mir::RawPtrKind {
+    type T = stable_mir::mir::RawPtrKind;
+    fn stable(&self, _: &mut Tables<'_>) -> Self::T {
+        use mir::RawPtrKind::*;
+        match *self {
+            Const => stable_mir::mir::RawPtrKind::Const,
+            Mut => stable_mir::mir::RawPtrKind::Mut,
+            FakeForPtrMetadata => stable_mir::mir::RawPtrKind::FakeForPtrMetadata,
+        }
+    }
+}
+
 impl<'tcx> Stable<'tcx> for mir::BorrowKind {
     type T = stable_mir::mir::BorrowKind;
     fn stable(&self, tables: &mut Tables<'_>) -> Self::T {

compiler/stable_mir/src/mir/body.rs

@@ -457,7 +457,7 @@ pub enum Rvalue {
     ///
     /// This is generated by pointer casts like `&v as *const _` or raw address of expressions like
     /// `&raw v` or `addr_of!(v)`.
-    AddressOf(Mutability, Place),
+    AddressOf(RawPtrKind, Place),
 
     /// Creates an aggregate value, like a tuple or struct.
     ///
@@ -577,7 +577,7 @@ impl Rvalue {
             }
             Rvalue::AddressOf(mutability, place) => {
                 let place_ty = place.ty(locals)?;
-                Ok(Ty::new_ptr(place_ty, *mutability))
+                Ok(Ty::new_ptr(place_ty, mutability.to_mutable_lossy()))
             }
             Rvalue::Len(..) => Ok(Ty::usize_ty()),
             Rvalue::Cast(.., ty) => Ok(*ty),
@@ -903,6 +903,24 @@ impl BorrowKind {
     }
 }
 
+#[derive(Copy, Clone, Debug, Eq, PartialEq, Serialize)]
+pub enum RawPtrKind {
+    Mut,
+    Const,
+    FakeForPtrMetadata,
+}
+
+impl RawPtrKind {
+    pub fn to_mutable_lossy(self) -> Mutability {
+        match self {
+            RawPtrKind::Mut { .. } => Mutability::Mut,
+            RawPtrKind::Const => Mutability::Not,
+            // FIXME: There's no type corresponding to a shallow borrow, so use `&` as an approximation.
+            RawPtrKind::FakeForPtrMetadata => Mutability::Not,
+        }
+    }
+}
+
 #[derive(Copy, Clone, Debug, Eq, PartialEq, Serialize)]
 pub enum MutBorrowKind {
     Default,

compiler/stable_mir/src/mir/pretty.rs

@@ -6,7 +6,9 @@ use std::{fmt, io, iter};
 use fmt::{Display, Formatter};
 
 use super::{AggregateKind, AssertMessage, BinOp, BorrowKind, FakeBorrowKind, TerminatorKind};
-use crate::mir::{Operand, Place, Rvalue, StatementKind, UnwindAction, VarDebugInfoContents};
+use crate::mir::{
+    Operand, Place, RawPtrKind, Rvalue, StatementKind, UnwindAction, VarDebugInfoContents,
+};
 use crate::ty::{AdtKind, IndexedVal, MirConst, Ty, TyConst};
 use crate::{Body, CrateDef, Mutability, with};
 
@@ -325,7 +327,7 @@ fn pretty_ty_const(ct: &TyConst) -> String {
 fn pretty_rvalue<W: Write>(writer: &mut W, rval: &Rvalue) -> io::Result<()> {
     match rval {
         Rvalue::AddressOf(mutability, place) => {
-            write!(writer, "&raw {} {:?}", pretty_mut(*mutability), place)
+            write!(writer, "&raw {} {:?}", pretty_raw_ptr_kind(*mutability), place)
         }
         Rvalue::Aggregate(aggregate_kind, operands) => {
             // FIXME: Add pretty_aggregate function that returns a pretty string
@@ -437,3 +439,11 @@ fn pretty_mut(mutability: Mutability) -> &'static str {
         Mutability::Mut => "mut ",
     }
 }
+
+fn pretty_raw_ptr_kind(kind: RawPtrKind) -> &'static str {
+    match kind {
+        RawPtrKind::Const => "const",
+        RawPtrKind::Mut => "mut",
+        RawPtrKind::FakeForPtrMetadata => "const (fake)",
+    }
+}

compiler/stable_mir/src/mir/visit.rs

@@ -308,7 +308,7 @@ pub trait MirVisitor {
     fn super_rvalue(&mut self, rvalue: &Rvalue, location: Location) {
         match rvalue {
             Rvalue::AddressOf(mutability, place) => {
-                let pcx = PlaceContext { is_mut: *mutability == Mutability::Mut };
+                let pcx = PlaceContext { is_mut: *mutability == RawPtrKind::Mut };
                 self.visit_place(place, pcx, location);
             }
             Rvalue::Aggregate(_, operands) => {

src/tools/miri/tests/pass/disjoint-array-accesses.rs

@@ -0,0 +1,35 @@
+// This is a regression test for issue #135671 where a MIR refactor about arrays and their lengths
+// unexpectedly caused borrowck errors for disjoint borrows of array elements, for which we had no
+// tests. This is a collection of a few code samples from that issue.
+
+//@revisions: stack tree
+//@[tree]compile-flags: -Zmiri-tree-borrows
+
+struct Test {
+    a: i32,
+    b: i32,
+}
+
+fn one() {
+    let inputs: &mut [_] = &mut [Test { a: 0, b: 0 }];
+    let a = &mut inputs[0].a;
+    let b = &mut inputs[0].b;
+
+    *a = 0;
+    *b = 1;
+}
+
+fn two() {
+    let slice = &mut [(0, 0)][..];
+    std::mem::swap(&mut slice[0].0, &mut slice[0].1);
+}
+
+fn three(a: &mut [(i32, i32)], i: usize, j: usize) -> (&mut i32, &mut i32) {
+    (&mut a[i].0, &mut a[j].1)
+}
+
+fn main() {
+    one();
+    two();
+    three(&mut [(1, 2), (3, 4)], 0, 1);
+}

tests/mir-opt/array_index_is_temporary.main.SimplifyCfg-pre-optimizations.after.panic-abort.mir

@@ -7,8 +7,7 @@ fn main() -> () {
     let mut _5: u32;
     let mut _6: *mut usize;
     let _7: usize;
-    let mut _8: usize;
-    let mut _9: bool;
+    let mut _8: bool;
     scope 1 {
         debug x => _1;
         let mut _2: usize;
@@ -41,9 +40,8 @@ fn main() -> () {
         StorageDead(_6);
         StorageLive(_7);
         _7 = copy _2;
-        _8 = Len(_1);
-        _9 = Lt(copy _7, copy _8);
-        assert(move _9, "index out of bounds: the length is {} but the index is {}", move _8, copy _7) -> [success: bb2, unwind unreachable];
+        _8 = Lt(copy _7, const 3_usize);
+        assert(move _8, "index out of bounds: the length is {} but the index is {}", const 3_usize, copy _7) -> [success: bb2, unwind unreachable];
     }
 
     bb2: {

tests/mir-opt/array_index_is_temporary.main.SimplifyCfg-pre-optimizations.after.panic-unwind.mir

@@ -7,8 +7,7 @@ fn main() -> () {
     let mut _5: u32;
     let mut _6: *mut usize;
     let _7: usize;
-    let mut _8: usize;
-    let mut _9: bool;
+    let mut _8: bool;
     scope 1 {
         debug x => _1;
         let mut _2: usize;
@@ -41,9 +40,8 @@ fn main() -> () {
         StorageDead(_6);
         StorageLive(_7);
         _7 = copy _2;
-        _8 = Len(_1);
-        _9 = Lt(copy _7, copy _8);
-        assert(move _9, "index out of bounds: the length is {} but the index is {}", move _8, copy _7) -> [success: bb2, unwind continue];
+        _8 = Lt(copy _7, const 3_usize);
+        assert(move _8, "index out of bounds: the length is {} but the index is {}", const 3_usize, copy _7) -> [success: bb2, unwind continue];
     }
 
     bb2: {

tests/mir-opt/building/index_array_and_slice.index_array.built.after.mir

@@ -0,0 +1,31 @@
+// MIR for `index_array` after built
+
+fn index_array(_1: &[i32; 7], _2: usize) -> &i32 {
+    debug array => _1;
+    debug index => _2;
+    let mut _0: &i32;
+    let _3: &i32;
+    let _4: usize;
+    let mut _5: bool;
+
+    bb0: {
+        StorageLive(_3);
+        StorageLive(_4);
+        _4 = copy _2;
+        FakeRead(ForIndex, (*_1));
+        _5 = Lt(copy _4, const 7_usize);
+        assert(move _5, "index out of bounds: the length is {} but the index is {}", const 7_usize, copy _4) -> [success: bb1, unwind: bb2];
+    }
+
+    bb1: {
+        _3 = &(*_1)[_4];
+        _0 = &(*_3);
+        StorageDead(_4);
+        StorageDead(_3);
+        return;
+    }
+
+    bb2 (cleanup): {
+        resume;
+    }
+}

tests/mir-opt/building/index_array_and_slice.index_const_generic_array.built.after.mir

@@ -0,0 +1,31 @@
+// MIR for `index_const_generic_array` after built
+
+fn index_const_generic_array(_1: &[i32; N], _2: usize) -> &i32 {
+    debug array => _1;
+    debug index => _2;
+    let mut _0: &i32;
+    let _3: &i32;
+    let _4: usize;
+    let mut _5: bool;
+
+    bb0: {
+        StorageLive(_3);
+        StorageLive(_4);
+        _4 = copy _2;
+        FakeRead(ForIndex, (*_1));
+        _5 = Lt(copy _4, const N);
+        assert(move _5, "index out of bounds: the length is {} but the index is {}", const N, copy _4) -> [success: bb1, unwind: bb2];
+    }
+
+    bb1: {
+        _3 = &(*_1)[_4];
+        _0 = &(*_3);
+        StorageDead(_4);
+        StorageDead(_3);
+        return;
+    }
+
+    bb2 (cleanup): {
+        resume;
+    }
+}

tests/mir-opt/building/index_array_and_slice.index_custom.built.after.mir

@@ -0,0 +1,34 @@
+// MIR for `index_custom` after built
+
+fn index_custom(_1: &WithSliceTail, _2: usize) -> &i32 {
+    debug custom => _1;
+    debug index => _2;
+    let mut _0: &i32;
+    let _3: &i32;
+    let _4: usize;
+    let mut _5: *const [i32];
+    let mut _6: usize;
+    let mut _7: bool;
+
+    bb0: {
+        StorageLive(_3);
+        StorageLive(_4);
+        _4 = copy _2;
+        _5 = &raw const (fake) ((*_1).1: [i32]);
+        _6 = PtrMetadata(move _5);
+        _7 = Lt(copy _4, copy _6);
+        assert(move _7, "index out of bounds: the length is {} but the index is {}", move _6, copy _4) -> [success: bb1, unwind: bb2];
+    }
+
+    bb1: {
+        _3 = &((*_1).1: [i32])[_4];
+        _0 = &(*_3);
+        StorageDead(_4);
+        StorageDead(_3);
+        return;
+    }
+
+    bb2 (cleanup): {
+        resume;
+    }
+}

tests/mir-opt/building/index_array_and_slice.index_mut_slice.built.after.mir

@@ -0,0 +1,34 @@
+// MIR for `index_mut_slice` after built
+
+fn index_mut_slice(_1: &mut [i32], _2: usize) -> &i32 {
+    debug slice => _1;
+    debug index => _2;
+    let mut _0: &i32;
+    let _3: &i32;
+    let _4: usize;
+    let mut _5: *const [i32];
+    let mut _6: usize;
+    let mut _7: bool;
+
+    bb0: {
+        StorageLive(_3);
+        StorageLive(_4);
+        _4 = copy _2;
+        _5 = &raw const (fake) (*_1);
+        _6 = PtrMetadata(move _5);
+        _7 = Lt(copy _4, copy _6);
+        assert(move _7, "index out of bounds: the length is {} but the index is {}", move _6, copy _4) -> [success: bb1, unwind: bb2];
+    }
+
+    bb1: {
+        _3 = &(*_1)[_4];
+        _0 = &(*_3);
+        StorageDead(_4);
+        StorageDead(_3);
+        return;
+    }
+
+    bb2 (cleanup): {
+        resume;
+    }
+}

tests/mir-opt/building/index_array_and_slice.index_slice.built.after.mir

@@ -0,0 +1,32 @@
+// MIR for `index_slice` after built
+
+fn index_slice(_1: &[i32], _2: usize) -> &i32 {
+    debug slice => _1;
+    debug index => _2;
+    let mut _0: &i32;
+    let _3: &i32;
+    let _4: usize;
+    let mut _5: usize;
+    let mut _6: bool;
+
+    bb0: {
+        StorageLive(_3);
+        StorageLive(_4);
+        _4 = copy _2;
+        _5 = PtrMetadata(copy _1);
+        _6 = Lt(copy _4, copy _5);
+        assert(move _6, "index out of bounds: the length is {} but the index is {}", move _5, copy _4) -> [success: bb1, unwind: bb2];
+    }
+
+    bb1: {
+        _3 = &(*_1)[_4];
+        _0 = &(*_3);
+        StorageDead(_4);
+        StorageDead(_3);
+        return;
+    }
+
+    bb2 (cleanup): {
+        resume;
+    }
+}

tests/mir-opt/building/index_array_and_slice.rs

@@ -0,0 +1,71 @@
+//@ compile-flags: -C opt-level=0
+
+// EMIT_MIR index_array_and_slice.index_array.built.after.mir
+fn index_array(array: &[i32; 7], index: usize) -> &i32 {
+    // CHECK: bb0:
+    // CHECK: [[LT:_.+]] = Lt(copy _2, const 7_usize);
+    // CHECK: assert(move [[LT]], "index out of bounds{{.+}}", const 7_usize, copy _2) -> [success: bb1, unwind
+
+    // CHECK: bb1:
+    // CHECK: _0 = &(*_1)[_2];
+    &array[index]
+}
+
+// EMIT_MIR index_array_and_slice.index_const_generic_array.built.after.mir
+fn index_const_generic_array<const N: usize>(array: &[i32; N], index: usize) -> &i32 {
+    // CHECK: bb0:
+    // CHECK: [[LT:_.+]] = Lt(copy _2, const N);
+    // CHECK: assert(move [[LT]], "index out of bounds{{.+}}", const N, copy _2) -> [success: bb1, unwind
+
+    // CHECK: bb1:
+    // CHECK: _0 = &(*_1)[_2];
+    &array[index]
+}
+
+// EMIT_MIR index_array_and_slice.index_slice.built.after.mir
+fn index_slice(slice: &[i32], index: usize) -> &i32 {
+    // CHECK: bb0:
+    // CHECK: [[LEN:_.+]] = PtrMetadata(copy _1);
+    // CHECK: [[LT:_.+]] = Lt(copy _2, copy [[LEN]]);
+    // CHECK: assert(move [[LT]], "index out of bounds{{.+}}", move [[LEN]], copy _2) -> [success: bb1,
+
+    // CHECK: bb1:
+    // CHECK: _0 = &(*_1)[_2];
+    &slice[index]
+}
+
+// EMIT_MIR index_array_and_slice.index_mut_slice.built.after.mir
+fn index_mut_slice(slice: &mut [i32], index: usize) -> &i32 {
+    // While the filecheck here is identical to the above test, the emitted MIR is different.
+    // This cannot `copy _1` in the *built* MIR, only in the *runtime* MIR.
+
+    // CHECK: bb0:
+    // CHECK: [[LEN:_.+]] = PtrMetadata(copy _1);
+    // CHECK: [[LT:_.+]] = Lt(copy _2, copy [[LEN]]);
+    // CHECK: assert(move [[LT]], "index out of bounds{{.+}}", move [[LEN]], copy _2) -> [success: bb1,
+
+    // CHECK: bb1:
+    // CHECK: _0 = &(*_1)[_2];
+    &slice[index]
+}
+
+struct WithSliceTail(f64, [i32]);
+
+// EMIT_MIR index_array_and_slice.index_custom.built.after.mir
+fn index_custom(custom: &WithSliceTail, index: usize) -> &i32 {
+    // CHECK: bb0:
+    // CHECK: [[PTR:_.+]] = &raw const (fake) ((*_1).1: [i32]);
+    // CHECK: [[LEN:_.+]] = PtrMetadata(move [[PTR]]);
+    // CHECK: [[LT:_.+]] = Lt(copy _2, copy [[LEN]]);
+    // CHECK: assert(move [[LT]], "index out of bounds{{.+}}", move [[LEN]], copy _2) -> [success: bb1,
+
+    // CHECK: bb1:
+    // CHECK: _0 = &((*_1).1: [i32])[_2];
+    &custom.1[index]
+}
+
+fn main() {
+    index_array(&[1, 2, 3, 4, 5, 6, 7], 3);
+    index_slice(&[1, 2, 3, 4, 5, 6, 7][..], 3);
+    _ = index_custom;
+}

tests/mir-opt/const_prop/array_index.main.GVN.32bit.panic-abort.diff

@@ -6,8 +6,7 @@
       let _1: u32;
       let mut _2: [u32; 4];
       let _3: usize;
-      let mut _4: usize;
-      let mut _5: bool;
+      let mut _4: bool;
       scope 1 {
           debug x => _1;
       }
@@ -18,11 +17,9 @@
           _2 = [const 0_u32, const 1_u32, const 2_u32, const 3_u32];
           StorageLive(_3);
           _3 = const 2_usize;
--         _4 = Len(_2);
--         _5 = Lt(copy _3, copy _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind unreachable];
-+         _4 = const 4_usize;
-+         _5 = const true;
+-         _4 = Lt(copy _3, const 4_usize);
+-         assert(move _4, "index out of bounds: the length is {} but the index is {}", const 4_usize, copy _3) -> [success: bb1, unwind unreachable];
++         _4 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 4_usize, const 2_usize) -> [success: bb1, unwind unreachable];
       }
   

tests/mir-opt/const_prop/array_index.main.GVN.32bit.panic-unwind.diff

@@ -6,8 +6,7 @@
       let _1: u32;
       let mut _2: [u32; 4];
       let _3: usize;
-      let mut _4: usize;
-      let mut _5: bool;
+      let mut _4: bool;
       scope 1 {
           debug x => _1;
       }
@@ -18,11 +17,9 @@
           _2 = [const 0_u32, const 1_u32, const 2_u32, const 3_u32];
           StorageLive(_3);
           _3 = const 2_usize;
--         _4 = Len(_2);
--         _5 = Lt(copy _3, copy _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind continue];
-+         _4 = const 4_usize;
-+         _5 = const true;
+-         _4 = Lt(copy _3, const 4_usize);
+-         assert(move _4, "index out of bounds: the length is {} but the index is {}", const 4_usize, copy _3) -> [success: bb1, unwind continue];
++         _4 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 4_usize, const 2_usize) -> [success: bb1, unwind continue];
       }
   

tests/mir-opt/const_prop/array_index.main.GVN.64bit.panic-abort.diff

@@ -6,8 +6,7 @@
       let _1: u32;
       let mut _2: [u32; 4];
       let _3: usize;
-      let mut _4: usize;
-      let mut _5: bool;
+      let mut _4: bool;
       scope 1 {
           debug x => _1;
       }
@@ -18,11 +17,9 @@
           _2 = [const 0_u32, const 1_u32, const 2_u32, const 3_u32];
           StorageLive(_3);
           _3 = const 2_usize;
--         _4 = Len(_2);
--         _5 = Lt(copy _3, copy _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind unreachable];
-+         _4 = const 4_usize;
-+         _5 = const true;
+-         _4 = Lt(copy _3, const 4_usize);
+-         assert(move _4, "index out of bounds: the length is {} but the index is {}", const 4_usize, copy _3) -> [success: bb1, unwind unreachable];
++         _4 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 4_usize, const 2_usize) -> [success: bb1, unwind unreachable];
       }
   

tests/mir-opt/const_prop/array_index.main.GVN.64bit.panic-unwind.diff

@@ -6,8 +6,7 @@
       let _1: u32;
       let mut _2: [u32; 4];
       let _3: usize;
-      let mut _4: usize;
-      let mut _5: bool;
+      let mut _4: bool;
       scope 1 {
           debug x => _1;
       }
@@ -18,11 +17,9 @@
           _2 = [const 0_u32, const 1_u32, const 2_u32, const 3_u32];
           StorageLive(_3);
           _3 = const 2_usize;
--         _4 = Len(_2);
--         _5 = Lt(copy _3, copy _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind continue];
-+         _4 = const 4_usize;
-+         _5 = const true;
+-         _4 = Lt(copy _3, const 4_usize);
+-         assert(move _4, "index out of bounds: the length is {} but the index is {}", const 4_usize, copy _3) -> [success: bb1, unwind continue];
++         _4 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 4_usize, const 2_usize) -> [success: bb1, unwind continue];
       }
   

tests/mir-opt/const_prop/bad_op_unsafe_oob_for_slices.main.GVN.32bit.panic-abort.diff

@@ -32,11 +32,12 @@
           StorageLive(_5);
           StorageLive(_6);
           _6 = const 3_usize;
-          _7 = Len((*_1));
+-         _7 = PtrMetadata(copy _1);
 -         _8 = Lt(copy _6, copy _7);
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind unreachable];
-+         _8 = Lt(const 3_usize, copy _7);
-+         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, const 3_usize) -> [success: bb1, unwind unreachable];
++         _7 = const 3_usize;
++         _8 = const false;
++         assert(const false, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 3_usize) -> [success: bb1, unwind unreachable];
       }
   
       bb1: {

tests/mir-opt/const_prop/bad_op_unsafe_oob_for_slices.main.GVN.32bit.panic-unwind.diff

@@ -32,11 +32,12 @@
           StorageLive(_5);
           StorageLive(_6);
           _6 = const 3_usize;
-          _7 = Len((*_1));
+-         _7 = PtrMetadata(copy _1);
 -         _8 = Lt(copy _6, copy _7);
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind continue];
-+         _8 = Lt(const 3_usize, copy _7);
-+         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, const 3_usize) -> [success: bb1, unwind continue];
++         _7 = const 3_usize;
++         _8 = const false;
++         assert(const false, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 3_usize) -> [success: bb1, unwind continue];
       }
   
       bb1: {

tests/mir-opt/const_prop/bad_op_unsafe_oob_for_slices.main.GVN.64bit.panic-abort.diff

@@ -32,11 +32,12 @@
           StorageLive(_5);
           StorageLive(_6);
           _6 = const 3_usize;
-          _7 = Len((*_1));
+-         _7 = PtrMetadata(copy _1);
 -         _8 = Lt(copy _6, copy _7);
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind unreachable];
-+         _8 = Lt(const 3_usize, copy _7);
-+         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, const 3_usize) -> [success: bb1, unwind unreachable];
++         _7 = const 3_usize;
++         _8 = const false;
++         assert(const false, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 3_usize) -> [success: bb1, unwind unreachable];
       }
   
       bb1: {

tests/mir-opt/const_prop/bad_op_unsafe_oob_for_slices.main.GVN.64bit.panic-unwind.diff

@@ -32,11 +32,12 @@
           StorageLive(_5);
           StorageLive(_6);
           _6 = const 3_usize;
-          _7 = Len((*_1));
+-         _7 = PtrMetadata(copy _1);
 -         _8 = Lt(copy _6, copy _7);
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind continue];
-+         _8 = Lt(const 3_usize, copy _7);
-+         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, const 3_usize) -> [success: bb1, unwind continue];
++         _7 = const 3_usize;
++         _8 = const false;
++         assert(const false, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 3_usize) -> [success: bb1, unwind continue];
       }
   
       bb1: {

tests/mir-opt/const_prop/large_array_index.main.GVN.32bit.panic-abort.diff

@@ -6,8 +6,7 @@
       let _1: u8;
       let mut _2: [u8; 5000];
       let _3: usize;
-      let mut _4: usize;
-      let mut _5: bool;
+      let mut _4: bool;
       scope 1 {
           debug x => _1;
       }
@@ -18,11 +17,9 @@
           _2 = [const 0_u8; 5000];
           StorageLive(_3);
           _3 = const 2_usize;
--         _4 = Len(_2);
--         _5 = Lt(copy _3, copy _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind unreachable];
-+         _4 = const 5000_usize;
-+         _5 = const true;
+-         _4 = Lt(copy _3, const 5000_usize);
+-         assert(move _4, "index out of bounds: the length is {} but the index is {}", const 5000_usize, copy _3) -> [success: bb1, unwind unreachable];
++         _4 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 5000_usize, const 2_usize) -> [success: bb1, unwind unreachable];
       }
   

tests/mir-opt/const_prop/large_array_index.main.GVN.32bit.panic-unwind.diff

@@ -6,8 +6,7 @@
       let _1: u8;
       let mut _2: [u8; 5000];
       let _3: usize;
-      let mut _4: usize;
-      let mut _5: bool;
+      let mut _4: bool;
       scope 1 {
           debug x => _1;
       }
@@ -18,11 +17,9 @@
           _2 = [const 0_u8; 5000];
           StorageLive(_3);
           _3 = const 2_usize;
--         _4 = Len(_2);
--         _5 = Lt(copy _3, copy _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind continue];
-+         _4 = const 5000_usize;
-+         _5 = const true;
+-         _4 = Lt(copy _3, const 5000_usize);
+-         assert(move _4, "index out of bounds: the length is {} but the index is {}", const 5000_usize, copy _3) -> [success: bb1, unwind continue];
++         _4 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 5000_usize, const 2_usize) -> [success: bb1, unwind continue];
       }
   

tests/mir-opt/const_prop/large_array_index.main.GVN.64bit.panic-abort.diff

@@ -6,8 +6,7 @@
       let _1: u8;
       let mut _2: [u8; 5000];
       let _3: usize;
-      let mut _4: usize;
-      let mut _5: bool;
+      let mut _4: bool;
       scope 1 {
           debug x => _1;
       }
@@ -18,11 +17,9 @@
           _2 = [const 0_u8; 5000];
           StorageLive(_3);
           _3 = const 2_usize;
--         _4 = Len(_2);
--         _5 = Lt(copy _3, copy _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind unreachable];
-+         _4 = const 5000_usize;
-+         _5 = const true;
+-         _4 = Lt(copy _3, const 5000_usize);
+-         assert(move _4, "index out of bounds: the length is {} but the index is {}", const 5000_usize, copy _3) -> [success: bb1, unwind unreachable];
++         _4 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 5000_usize, const 2_usize) -> [success: bb1, unwind unreachable];
       }
   

tests/mir-opt/const_prop/large_array_index.main.GVN.64bit.panic-unwind.diff

@@ -6,8 +6,7 @@
       let _1: u8;
       let mut _2: [u8; 5000];
       let _3: usize;
-      let mut _4: usize;
-      let mut _5: bool;
+      let mut _4: bool;
       scope 1 {
           debug x => _1;
       }
@@ -18,11 +17,9 @@
           _2 = [const 0_u8; 5000];
           StorageLive(_3);
           _3 = const 2_usize;
--         _4 = Len(_2);
--         _5 = Lt(copy _3, copy _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind continue];
-+         _4 = const 5000_usize;
-+         _5 = const true;
+-         _4 = Lt(copy _3, const 5000_usize);
+-         assert(move _4, "index out of bounds: the length is {} but the index is {}", const 5000_usize, copy _3) -> [success: bb1, unwind continue];
++         _4 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 5000_usize, const 2_usize) -> [success: bb1, unwind continue];
       }
   

tests/mir-opt/const_prop/repeat.main.GVN.32bit.panic-abort.diff

@@ -7,8 +7,7 @@
       let mut _2: u32;
       let mut _3: [u32; 8];
       let _4: usize;
-      let mut _5: usize;
-      let mut _6: bool;
+      let mut _5: bool;
       scope 1 {
           debug x => _1;
       }
@@ -20,11 +19,9 @@
           _3 = [const 42_u32; 8];
           StorageLive(_4);
           _4 = const 2_usize;
--         _5 = Len(_3);
--         _6 = Lt(copy _4, copy _5);
--         assert(move _6, "index out of bounds: the length is {} but the index is {}", move _5, copy _4) -> [success: bb1, unwind unreachable];
-+         _5 = const 8_usize;
-+         _6 = const true;
+-         _5 = Lt(copy _4, const 8_usize);
+-         assert(move _5, "index out of bounds: the length is {} but the index is {}", const 8_usize, copy _4) -> [success: bb1, unwind unreachable];
++         _5 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 8_usize, const 2_usize) -> [success: bb1, unwind unreachable];
       }
   

tests/mir-opt/const_prop/repeat.main.GVN.32bit.panic-unwind.diff

@@ -7,8 +7,7 @@
       let mut _2: u32;
       let mut _3: [u32; 8];
       let _4: usize;
-      let mut _5: usize;
-      let mut _6: bool;
+      let mut _5: bool;
       scope 1 {
           debug x => _1;
       }
@@ -20,11 +19,9 @@
           _3 = [const 42_u32; 8];
           StorageLive(_4);
           _4 = const 2_usize;
--         _5 = Len(_3);
--         _6 = Lt(copy _4, copy _5);
--         assert(move _6, "index out of bounds: the length is {} but the index is {}", move _5, copy _4) -> [success: bb1, unwind continue];
-+         _5 = const 8_usize;
-+         _6 = const true;
+-         _5 = Lt(copy _4, const 8_usize);
+-         assert(move _5, "index out of bounds: the length is {} but the index is {}", const 8_usize, copy _4) -> [success: bb1, unwind continue];
++         _5 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 8_usize, const 2_usize) -> [success: bb1, unwind continue];
       }
   

tests/mir-opt/const_prop/repeat.main.GVN.64bit.panic-abort.diff

@@ -7,8 +7,7 @@
       let mut _2: u32;
       let mut _3: [u32; 8];
       let _4: usize;
-      let mut _5: usize;
-      let mut _6: bool;
+      let mut _5: bool;
       scope 1 {
           debug x => _1;
       }
@@ -20,11 +19,9 @@
           _3 = [const 42_u32; 8];
           StorageLive(_4);
           _4 = const 2_usize;
--         _5 = Len(_3);
--         _6 = Lt(copy _4, copy _5);
--         assert(move _6, "index out of bounds: the length is {} but the index is {}", move _5, copy _4) -> [success: bb1, unwind unreachable];
-+         _5 = const 8_usize;
-+         _6 = const true;
+-         _5 = Lt(copy _4, const 8_usize);
+-         assert(move _5, "index out of bounds: the length is {} but the index is {}", const 8_usize, copy _4) -> [success: bb1, unwind unreachable];
++         _5 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 8_usize, const 2_usize) -> [success: bb1, unwind unreachable];
       }
   

tests/mir-opt/const_prop/repeat.main.GVN.64bit.panic-unwind.diff

@@ -7,8 +7,7 @@
       let mut _2: u32;
       let mut _3: [u32; 8];
       let _4: usize;
-      let mut _5: usize;
-      let mut _6: bool;
+      let mut _5: bool;
       scope 1 {
           debug x => _1;
       }
@@ -20,11 +19,9 @@
           _3 = [const 42_u32; 8];
           StorageLive(_4);
           _4 = const 2_usize;
--         _5 = Len(_3);
--         _6 = Lt(copy _4, copy _5);
--         assert(move _6, "index out of bounds: the length is {} but the index is {}", move _5, copy _4) -> [success: bb1, unwind continue];
-+         _5 = const 8_usize;
-+         _6 = const true;
+-         _5 = Lt(copy _4, const 8_usize);
+-         assert(move _5, "index out of bounds: the length is {} but the index is {}", const 8_usize, copy _4) -> [success: bb1, unwind continue];
++         _5 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 8_usize, const 2_usize) -> [success: bb1, unwind continue];
       }
   

tests/mir-opt/const_prop/slice_len.main.GVN.32bit.panic-abort.diff

@@ -30,11 +30,12 @@
           StorageDead(_3);
           StorageLive(_6);
           _6 = const 1_usize;
-          _7 = Len((*_2));
+-         _7 = PtrMetadata(copy _2);
 -         _8 = Lt(copy _6, copy _7);
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind unreachable];
-+         _8 = Lt(const 1_usize, copy _7);
-+         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, const 1_usize) -> [success: bb1, unwind unreachable];
++         _7 = const 3_usize;
++         _8 = const true;
++         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb1, unwind unreachable];
       }
   
       bb1: {

tests/mir-opt/const_prop/slice_len.main.GVN.32bit.panic-unwind.diff

@@ -30,11 +30,12 @@
           StorageDead(_3);
           StorageLive(_6);
           _6 = const 1_usize;
-          _7 = Len((*_2));
+-         _7 = PtrMetadata(copy _2);
 -         _8 = Lt(copy _6, copy _7);
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind continue];
-+         _8 = Lt(const 1_usize, copy _7);
-+         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, const 1_usize) -> [success: bb1, unwind continue];
++         _7 = const 3_usize;
++         _8 = const true;
++         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb1, unwind continue];
       }
   
       bb1: {

tests/mir-opt/const_prop/slice_len.main.GVN.64bit.panic-abort.diff

@@ -30,11 +30,12 @@
           StorageDead(_3);
           StorageLive(_6);
           _6 = const 1_usize;
-          _7 = Len((*_2));
+-         _7 = PtrMetadata(copy _2);
 -         _8 = Lt(copy _6, copy _7);
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind unreachable];
-+         _8 = Lt(const 1_usize, copy _7);
-+         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, const 1_usize) -> [success: bb1, unwind unreachable];
++         _7 = const 3_usize;
++         _8 = const true;
++         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb1, unwind unreachable];
       }
   
       bb1: {

tests/mir-opt/const_prop/slice_len.main.GVN.64bit.panic-unwind.diff

@@ -30,11 +30,12 @@
           StorageDead(_3);
           StorageLive(_6);
           _6 = const 1_usize;
-          _7 = Len((*_2));
+-         _7 = PtrMetadata(copy _2);
 -         _8 = Lt(copy _6, copy _7);
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind continue];
-+         _8 = Lt(const 1_usize, copy _7);
-+         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, const 1_usize) -> [success: bb1, unwind continue];
++         _7 = const 3_usize;
++         _8 = const true;
++         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb1, unwind continue];
       }
   
       bb1: {

tests/mir-opt/copy-prop/issue_107511.main.CopyProp.panic-abort.diff

@@ -18,8 +18,7 @@
       let mut _15: !;
       let mut _17: i32;
       let _18: usize;
-      let mut _19: usize;
-      let mut _20: bool;
+      let mut _19: bool;
       scope 1 {
           debug sum => _1;
           let _2: [i32; 4];
@@ -92,11 +91,10 @@
           StorageLive(_17);
 -         StorageLive(_18);
 -         _18 = copy _16;
-          _19 = Len(_2);
--         _20 = Lt(copy _18, copy _19);
--         assert(move _20, "index out of bounds: the length is {} but the index is {}", move _19, copy _18) -> [success: bb8, unwind unreachable];
-+         _20 = Lt(copy _16, copy _19);
-+         assert(move _20, "index out of bounds: the length is {} but the index is {}", move _19, copy _16) -> [success: bb8, unwind unreachable];
+-         _19 = Lt(copy _18, const 4_usize);
+-         assert(move _19, "index out of bounds: the length is {} but the index is {}", const 4_usize, copy _18) -> [success: bb8, unwind unreachable];
++         _19 = Lt(copy _16, const 4_usize);
++         assert(move _19, "index out of bounds: the length is {} but the index is {}", const 4_usize, copy _16) -> [success: bb8, unwind unreachable];
       }
   
       bb7: {

tests/mir-opt/copy-prop/issue_107511.main.CopyProp.panic-unwind.diff

@@ -18,8 +18,7 @@
       let mut _15: !;
       let mut _17: i32;
       let _18: usize;
-      let mut _19: usize;
-      let mut _20: bool;
+      let mut _19: bool;
       scope 1 {
           debug sum => _1;
           let _2: [i32; 4];
@@ -92,11 +91,10 @@
           StorageLive(_17);
 -         StorageLive(_18);
 -         _18 = copy _16;
-          _19 = Len(_2);
--         _20 = Lt(copy _18, copy _19);
--         assert(move _20, "index out of bounds: the length is {} but the index is {}", move _19, copy _18) -> [success: bb8, unwind continue];
-+         _20 = Lt(copy _16, copy _19);
-+         assert(move _20, "index out of bounds: the length is {} but the index is {}", move _19, copy _16) -> [success: bb8, unwind continue];
+-         _19 = Lt(copy _18, const 4_usize);
+-         assert(move _19, "index out of bounds: the length is {} but the index is {}", const 4_usize, copy _18) -> [success: bb8, unwind continue];
++         _19 = Lt(copy _16, const 4_usize);
++         assert(move _19, "index out of bounds: the length is {} but the index is {}", const 4_usize, copy _16) -> [success: bb8, unwind continue];
       }
   
       bb7: {

tests/mir-opt/dataflow-const-prop/array_index.main.DataflowConstProp.32bit.panic-abort.diff

@@ -6,8 +6,7 @@
       let _1: u32;
       let mut _2: [u32; 4];
       let _3: usize;
-      let mut _4: usize;
-      let mut _5: bool;
+      let mut _4: bool;
       scope 1 {
           debug x => _1;
       }
@@ -18,11 +17,9 @@
           _2 = [const 0_u32, const 1_u32, const 2_u32, const 3_u32];
           StorageLive(_3);
           _3 = const 2_usize;
--         _4 = Len(_2);
--         _5 = Lt(copy _3, copy _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind unreachable];
-+         _4 = const 4_usize;
-+         _5 = const true;
+-         _4 = Lt(copy _3, const 4_usize);
+-         assert(move _4, "index out of bounds: the length is {} but the index is {}", const 4_usize, copy _3) -> [success: bb1, unwind unreachable];
++         _4 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 4_usize, const 2_usize) -> [success: bb1, unwind unreachable];
       }
   

tests/mir-opt/dataflow-const-prop/array_index.main.DataflowConstProp.32bit.panic-unwind.diff

@@ -6,8 +6,7 @@
       let _1: u32;
       let mut _2: [u32; 4];
       let _3: usize;
-      let mut _4: usize;
-      let mut _5: bool;
+      let mut _4: bool;
       scope 1 {
           debug x => _1;
       }
@@ -18,11 +17,9 @@
           _2 = [const 0_u32, const 1_u32, const 2_u32, const 3_u32];
           StorageLive(_3);
           _3 = const 2_usize;
--         _4 = Len(_2);
--         _5 = Lt(copy _3, copy _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind continue];
-+         _4 = const 4_usize;
-+         _5 = const true;
+-         _4 = Lt(copy _3, const 4_usize);
+-         assert(move _4, "index out of bounds: the length is {} but the index is {}", const 4_usize, copy _3) -> [success: bb1, unwind continue];
++         _4 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 4_usize, const 2_usize) -> [success: bb1, unwind continue];
       }
   

tests/mir-opt/dataflow-const-prop/array_index.main.DataflowConstProp.64bit.panic-abort.diff

@@ -6,8 +6,7 @@
       let _1: u32;
       let mut _2: [u32; 4];
       let _3: usize;
-      let mut _4: usize;
-      let mut _5: bool;
+      let mut _4: bool;
       scope 1 {
           debug x => _1;
       }
@@ -18,11 +17,9 @@
           _2 = [const 0_u32, const 1_u32, const 2_u32, const 3_u32];
           StorageLive(_3);
           _3 = const 2_usize;
--         _4 = Len(_2);
--         _5 = Lt(copy _3, copy _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind unreachable];
-+         _4 = const 4_usize;
-+         _5 = const true;
+-         _4 = Lt(copy _3, const 4_usize);
+-         assert(move _4, "index out of bounds: the length is {} but the index is {}", const 4_usize, copy _3) -> [success: bb1, unwind unreachable];
++         _4 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 4_usize, const 2_usize) -> [success: bb1, unwind unreachable];
       }
   

tests/mir-opt/dataflow-const-prop/array_index.main.DataflowConstProp.64bit.panic-unwind.diff

@@ -6,8 +6,7 @@
       let _1: u32;
       let mut _2: [u32; 4];
       let _3: usize;
-      let mut _4: usize;
-      let mut _5: bool;
+      let mut _4: bool;
       scope 1 {
           debug x => _1;
       }
@@ -18,11 +17,9 @@
           _2 = [const 0_u32, const 1_u32, const 2_u32, const 3_u32];
           StorageLive(_3);
           _3 = const 2_usize;
--         _4 = Len(_2);
--         _5 = Lt(copy _3, copy _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind continue];
-+         _4 = const 4_usize;
-+         _5 = const true;
+-         _4 = Lt(copy _3, const 4_usize);
+-         assert(move _4, "index out of bounds: the length is {} but the index is {}", const 4_usize, copy _3) -> [success: bb1, unwind continue];
++         _4 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 4_usize, const 2_usize) -> [success: bb1, unwind continue];
       }
   

tests/mir-opt/dataflow-const-prop/array_index.rs

@@ -11,9 +11,10 @@ fn main() {
 
     // CHECK:       [[array_lit]] = [const 0_u32, const 1_u32, const 2_u32, const 3_u32];
     // CHECK-NOT:   {{_.*}} = Len(
+    // CHECK-NOT:   {{_.*}} = PtrMetadata(
     // CHECK-NOT:   {{_.*}} = Lt(
     // CHECK-NOT:   assert(move _
-    // CHECK:       {{_.*}} = const 4_usize;
+    // CHECK:       {{_.*}} = const 2_usize;
     // CHECK:       {{_.*}} = const true;
     // CHECK:       assert(const true
     // CHECK:       [[x]] = copy [[array_lit]][2 of 3];

tests/mir-opt/dataflow-const-prop/large_array_index.main.DataflowConstProp.32bit.panic-abort.diff

@@ -6,8 +6,7 @@
       let _1: u8;
       let mut _2: [u8; 5000];
       let _3: usize;
-      let mut _4: usize;
-      let mut _5: bool;
+      let mut _4: bool;
       scope 1 {
           debug x => _1;
       }
@@ -18,11 +17,9 @@
           _2 = [const 0_u8; 5000];
           StorageLive(_3);
           _3 = const 2_usize;
--         _4 = Len(_2);
--         _5 = Lt(copy _3, copy _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind unreachable];
-+         _4 = const 5000_usize;
-+         _5 = const true;
+-         _4 = Lt(copy _3, const 5000_usize);
+-         assert(move _4, "index out of bounds: the length is {} but the index is {}", const 5000_usize, copy _3) -> [success: bb1, unwind unreachable];
++         _4 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 5000_usize, const 2_usize) -> [success: bb1, unwind unreachable];
       }
   

tests/mir-opt/dataflow-const-prop/large_array_index.main.DataflowConstProp.32bit.panic-unwind.diff

@@ -6,8 +6,7 @@
       let _1: u8;
       let mut _2: [u8; 5000];
       let _3: usize;
-      let mut _4: usize;
-      let mut _5: bool;
+      let mut _4: bool;
       scope 1 {
           debug x => _1;
       }
@@ -18,11 +17,9 @@
           _2 = [const 0_u8; 5000];
           StorageLive(_3);
           _3 = const 2_usize;
--         _4 = Len(_2);
--         _5 = Lt(copy _3, copy _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind continue];
-+         _4 = const 5000_usize;
-+         _5 = const true;
+-         _4 = Lt(copy _3, const 5000_usize);
+-         assert(move _4, "index out of bounds: the length is {} but the index is {}", const 5000_usize, copy _3) -> [success: bb1, unwind continue];
++         _4 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 5000_usize, const 2_usize) -> [success: bb1, unwind continue];
       }
   

tests/mir-opt/dataflow-const-prop/large_array_index.main.DataflowConstProp.64bit.panic-abort.diff

@@ -6,8 +6,7 @@
       let _1: u8;
       let mut _2: [u8; 5000];
       let _3: usize;
-      let mut _4: usize;
-      let mut _5: bool;
+      let mut _4: bool;
       scope 1 {
           debug x => _1;
       }
@@ -18,11 +17,9 @@
           _2 = [const 0_u8; 5000];
           StorageLive(_3);
           _3 = const 2_usize;
--         _4 = Len(_2);
--         _5 = Lt(copy _3, copy _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind unreachable];
-+         _4 = const 5000_usize;
-+         _5 = const true;
+-         _4 = Lt(copy _3, const 5000_usize);
+-         assert(move _4, "index out of bounds: the length is {} but the index is {}", const 5000_usize, copy _3) -> [success: bb1, unwind unreachable];
++         _4 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 5000_usize, const 2_usize) -> [success: bb1, unwind unreachable];
       }
   

tests/mir-opt/dataflow-const-prop/large_array_index.main.DataflowConstProp.64bit.panic-unwind.diff

@@ -6,8 +6,7 @@
       let _1: u8;
       let mut _2: [u8; 5000];
       let _3: usize;
-      let mut _4: usize;
-      let mut _5: bool;
+      let mut _4: bool;
       scope 1 {
           debug x => _1;
       }
@@ -18,11 +17,9 @@
           _2 = [const 0_u8; 5000];
           StorageLive(_3);
           _3 = const 2_usize;
--         _4 = Len(_2);
--         _5 = Lt(copy _3, copy _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind continue];
-+         _4 = const 5000_usize;
-+         _5 = const true;
+-         _4 = Lt(copy _3, const 5000_usize);
+-         assert(move _4, "index out of bounds: the length is {} but the index is {}", const 5000_usize, copy _3) -> [success: bb1, unwind continue];
++         _4 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 5000_usize, const 2_usize) -> [success: bb1, unwind continue];
       }
   

tests/mir-opt/dataflow-const-prop/large_array_index.rs

@@ -10,7 +10,7 @@ fn main() {
 
     // CHECK: debug x => [[x:_.*]];
     // CHECK: [[array_lit:_.*]] = [const 0_u8; 5000];
-    // CHECK: {{_.*}} = const 5000_usize;
+    // CHECK: {{_.*}} = const 2_usize;
     // CHECK: {{_.*}} = const true;
     // CHECK: assert(const true
     // CHECK: [[x]] = copy [[array_lit]][2 of 3];

tests/mir-opt/dataflow-const-prop/repeat.main.DataflowConstProp.32bit.panic-abort.diff

@@ -7,8 +7,7 @@
       let mut _2: u32;
       let mut _3: [u32; 8];
       let _4: usize;
-      let mut _5: usize;
-      let mut _6: bool;
+      let mut _5: bool;
       scope 1 {
           debug x => _1;
       }
@@ -20,11 +19,9 @@
           _3 = [const 42_u32; 8];
           StorageLive(_4);
           _4 = const 2_usize;
--         _5 = Len(_3);
--         _6 = Lt(copy _4, copy _5);
--         assert(move _6, "index out of bounds: the length is {} but the index is {}", move _5, copy _4) -> [success: bb1, unwind unreachable];
-+         _5 = const 8_usize;
-+         _6 = const true;
+-         _5 = Lt(copy _4, const 8_usize);
+-         assert(move _5, "index out of bounds: the length is {} but the index is {}", const 8_usize, copy _4) -> [success: bb1, unwind unreachable];
++         _5 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 8_usize, const 2_usize) -> [success: bb1, unwind unreachable];
       }
   

tests/mir-opt/dataflow-const-prop/repeat.main.DataflowConstProp.32bit.panic-unwind.diff

@@ -7,8 +7,7 @@
       let mut _2: u32;
       let mut _3: [u32; 8];
       let _4: usize;
-      let mut _5: usize;
-      let mut _6: bool;
+      let mut _5: bool;
       scope 1 {
           debug x => _1;
       }
@@ -20,11 +19,9 @@
           _3 = [const 42_u32; 8];
           StorageLive(_4);
           _4 = const 2_usize;
--         _5 = Len(_3);
--         _6 = Lt(copy _4, copy _5);
--         assert(move _6, "index out of bounds: the length is {} but the index is {}", move _5, copy _4) -> [success: bb1, unwind continue];
-+         _5 = const 8_usize;
-+         _6 = const true;
+-         _5 = Lt(copy _4, const 8_usize);
+-         assert(move _5, "index out of bounds: the length is {} but the index is {}", const 8_usize, copy _4) -> [success: bb1, unwind continue];
++         _5 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 8_usize, const 2_usize) -> [success: bb1, unwind continue];
       }
   

tests/mir-opt/dataflow-const-prop/repeat.main.DataflowConstProp.64bit.panic-abort.diff

@@ -7,8 +7,7 @@
       let mut _2: u32;
       let mut _3: [u32; 8];
       let _4: usize;
-      let mut _5: usize;
-      let mut _6: bool;
+      let mut _5: bool;
       scope 1 {
           debug x => _1;
       }
@@ -20,11 +19,9 @@
           _3 = [const 42_u32; 8];
           StorageLive(_4);
           _4 = const 2_usize;
--         _5 = Len(_3);
--         _6 = Lt(copy _4, copy _5);
--         assert(move _6, "index out of bounds: the length is {} but the index is {}", move _5, copy _4) -> [success: bb1, unwind unreachable];
-+         _5 = const 8_usize;
-+         _6 = const true;
+-         _5 = Lt(copy _4, const 8_usize);
+-         assert(move _5, "index out of bounds: the length is {} but the index is {}", const 8_usize, copy _4) -> [success: bb1, unwind unreachable];
++         _5 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 8_usize, const 2_usize) -> [success: bb1, unwind unreachable];
       }
   

tests/mir-opt/dataflow-const-prop/repeat.main.DataflowConstProp.64bit.panic-unwind.diff

@@ -7,8 +7,7 @@
       let mut _2: u32;
       let mut _3: [u32; 8];
       let _4: usize;
-      let mut _5: usize;
-      let mut _6: bool;
+      let mut _5: bool;
       scope 1 {
           debug x => _1;
       }
@@ -20,11 +19,9 @@
           _3 = [const 42_u32; 8];
           StorageLive(_4);
           _4 = const 2_usize;
--         _5 = Len(_3);
--         _6 = Lt(copy _4, copy _5);
--         assert(move _6, "index out of bounds: the length is {} but the index is {}", move _5, copy _4) -> [success: bb1, unwind continue];
-+         _5 = const 8_usize;
-+         _6 = const true;
+-         _5 = Lt(copy _4, const 8_usize);
+-         assert(move _5, "index out of bounds: the length is {} but the index is {}", const 8_usize, copy _4) -> [success: bb1, unwind continue];
++         _5 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 8_usize, const 2_usize) -> [success: bb1, unwind continue];
       }
   

tests/mir-opt/dataflow-const-prop/repeat.rs

@@ -9,8 +9,9 @@ fn main() {
 
     // CHECK: [[array_lit:_.*]] = [const 42_u32; 8];
     // CHECK-NOT: {{_.*}} = Len(
+    // CHECK-NOT: {{_.*}} = PtrMetadata(
     // CHECK-NOT: {{_.*}} = Lt(
-    // CHECK: {{_.*}} = const 8_usize;
+    // CHECK: {{_.*}} = const 2_usize;
     // CHECK: {{_.*}} = const true;
     // CHECK: assert(const true
 

tests/mir-opt/dataflow-const-prop/slice_len.main.DataflowConstProp.32bit.panic-abort.diff

@@ -1,77 +0,0 @@
-- // MIR for `main` before DataflowConstProp
-+ // MIR for `main` after DataflowConstProp
-  
-  fn main() -> () {
-      let mut _0: ();
-      let _1: u32;
-      let mut _2: &[u32];
-      let mut _3: &[u32; 3];
-      let _4: &[u32; 3];
-      let _5: [u32; 3];
-      let _6: usize;
-      let mut _7: usize;
-      let mut _8: bool;
-      let mut _10: &[u32];
-      let _11: usize;
-      let mut _12: usize;
-      let mut _13: bool;
-      let mut _14: &[u32; 3];
-      scope 1 {
-          debug local => _1;
-          let _9: u32;
-          scope 2 {
-              debug constant => _9;
-          }
-      }
-  
-      bb0: {
-          StorageLive(_1);
-          StorageLive(_2);
-          StorageLive(_3);
-          StorageLive(_4);
-          _14 = const main::promoted[0];
-          _4 = copy _14;
-          _3 = copy _4;
-          _2 = move _3 as &[u32] (PointerCoercion(Unsize, AsCast));
-          StorageDead(_3);
-          StorageLive(_6);
-          _6 = const 1_usize;
--         _7 = Len((*_2));
--         _8 = Lt(copy _6, copy _7);
--         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind unreachable];
-+         _7 = const 3_usize;
-+         _8 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb1, unwind unreachable];
-      }
-  
-      bb1: {
--         _1 = copy (*_2)[_6];
-+         _1 = copy (*_2)[1 of 2];
-          StorageDead(_6);
-          StorageDead(_4);
-          StorageDead(_2);
-          StorageLive(_9);
-          StorageLive(_10);
-          _10 = const main::SLICE;
-          StorageLive(_11);
-          _11 = const 1_usize;
--         _12 = Len((*_10));
--         _13 = Lt(copy _11, copy _12);
--         assert(move _13, "index out of bounds: the length is {} but the index is {}", move _12, copy _11) -> [success: bb2, unwind unreachable];
-+         _12 = const 3_usize;
-+         _13 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb2, unwind unreachable];
-      }
-  
-      bb2: {
--         _9 = copy (*_10)[_11];
-+         _9 = copy (*_10)[1 of 2];
-          StorageDead(_11);
-          StorageDead(_10);
-          _0 = const ();
-          StorageDead(_9);
-          StorageDead(_1);
-          return;
-      }
-  }
-  

tests/mir-opt/dataflow-const-prop/slice_len.main.DataflowConstProp.32bit.panic-unwind.diff

@@ -1,77 +0,0 @@
-- // MIR for `main` before DataflowConstProp
-+ // MIR for `main` after DataflowConstProp
-  
-  fn main() -> () {
-      let mut _0: ();
-      let _1: u32;
-      let mut _2: &[u32];
-      let mut _3: &[u32; 3];
-      let _4: &[u32; 3];
-      let _5: [u32; 3];
-      let _6: usize;
-      let mut _7: usize;
-      let mut _8: bool;
-      let mut _10: &[u32];
-      let _11: usize;
-      let mut _12: usize;
-      let mut _13: bool;
-      let mut _14: &[u32; 3];
-      scope 1 {
-          debug local => _1;
-          let _9: u32;
-          scope 2 {
-              debug constant => _9;
-          }
-      }
-  
-      bb0: {
-          StorageLive(_1);
-          StorageLive(_2);
-          StorageLive(_3);
-          StorageLive(_4);
-          _14 = const main::promoted[0];
-          _4 = copy _14;
-          _3 = copy _4;
-          _2 = move _3 as &[u32] (PointerCoercion(Unsize, AsCast));
-          StorageDead(_3);
-          StorageLive(_6);
-          _6 = const 1_usize;
--         _7 = Len((*_2));
--         _8 = Lt(copy _6, copy _7);
--         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind continue];
-+         _7 = const 3_usize;
-+         _8 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb1, unwind continue];
-      }
-  
-      bb1: {
--         _1 = copy (*_2)[_6];
-+         _1 = copy (*_2)[1 of 2];
-          StorageDead(_6);
-          StorageDead(_4);
-          StorageDead(_2);
-          StorageLive(_9);
-          StorageLive(_10);
-          _10 = const main::SLICE;
-          StorageLive(_11);
-          _11 = const 1_usize;
--         _12 = Len((*_10));
--         _13 = Lt(copy _11, copy _12);
--         assert(move _13, "index out of bounds: the length is {} but the index is {}", move _12, copy _11) -> [success: bb2, unwind continue];
-+         _12 = const 3_usize;
-+         _13 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb2, unwind continue];
-      }
-  
-      bb2: {
--         _9 = copy (*_10)[_11];
-+         _9 = copy (*_10)[1 of 2];
-          StorageDead(_11);
-          StorageDead(_10);
-          _0 = const ();
-          StorageDead(_9);
-          StorageDead(_1);
-          return;
-      }
-  }
-  

tests/mir-opt/dataflow-const-prop/slice_len.main.DataflowConstProp.64bit.panic-abort.diff

@@ -1,77 +0,0 @@
-- // MIR for `main` before DataflowConstProp
-+ // MIR for `main` after DataflowConstProp
-  
-  fn main() -> () {
-      let mut _0: ();
-      let _1: u32;
-      let mut _2: &[u32];
-      let mut _3: &[u32; 3];
-      let _4: &[u32; 3];
-      let _5: [u32; 3];
-      let _6: usize;
-      let mut _7: usize;
-      let mut _8: bool;
-      let mut _10: &[u32];
-      let _11: usize;
-      let mut _12: usize;
-      let mut _13: bool;
-      let mut _14: &[u32; 3];
-      scope 1 {
-          debug local => _1;
-          let _9: u32;
-          scope 2 {
-              debug constant => _9;
-          }
-      }
-  
-      bb0: {
-          StorageLive(_1);
-          StorageLive(_2);
-          StorageLive(_3);
-          StorageLive(_4);
-          _14 = const main::promoted[0];
-          _4 = copy _14;
-          _3 = copy _4;
-          _2 = move _3 as &[u32] (PointerCoercion(Unsize, AsCast));
-          StorageDead(_3);
-          StorageLive(_6);
-          _6 = const 1_usize;
--         _7 = Len((*_2));
--         _8 = Lt(copy _6, copy _7);
--         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind unreachable];
-+         _7 = const 3_usize;
-+         _8 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb1, unwind unreachable];
-      }
-  
-      bb1: {
--         _1 = copy (*_2)[_6];
-+         _1 = copy (*_2)[1 of 2];
-          StorageDead(_6);
-          StorageDead(_4);
-          StorageDead(_2);
-          StorageLive(_9);
-          StorageLive(_10);
-          _10 = const main::SLICE;
-          StorageLive(_11);
-          _11 = const 1_usize;
--         _12 = Len((*_10));
--         _13 = Lt(copy _11, copy _12);
--         assert(move _13, "index out of bounds: the length is {} but the index is {}", move _12, copy _11) -> [success: bb2, unwind unreachable];
-+         _12 = const 3_usize;
-+         _13 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb2, unwind unreachable];
-      }
-  
-      bb2: {
--         _9 = copy (*_10)[_11];
-+         _9 = copy (*_10)[1 of 2];
-          StorageDead(_11);
-          StorageDead(_10);
-          _0 = const ();
-          StorageDead(_9);
-          StorageDead(_1);
-          return;
-      }
-  }
-  

tests/mir-opt/dataflow-const-prop/slice_len.main.DataflowConstProp.64bit.panic-unwind.diff

@@ -1,77 +0,0 @@
-- // MIR for `main` before DataflowConstProp
-+ // MIR for `main` after DataflowConstProp
-  
-  fn main() -> () {
-      let mut _0: ();
-      let _1: u32;
-      let mut _2: &[u32];
-      let mut _3: &[u32; 3];
-      let _4: &[u32; 3];
-      let _5: [u32; 3];
-      let _6: usize;
-      let mut _7: usize;
-      let mut _8: bool;
-      let mut _10: &[u32];
-      let _11: usize;
-      let mut _12: usize;
-      let mut _13: bool;
-      let mut _14: &[u32; 3];
-      scope 1 {
-          debug local => _1;
-          let _9: u32;
-          scope 2 {
-              debug constant => _9;
-          }
-      }
-  
-      bb0: {
-          StorageLive(_1);
-          StorageLive(_2);
-          StorageLive(_3);
-          StorageLive(_4);
-          _14 = const main::promoted[0];
-          _4 = copy _14;
-          _3 = copy _4;
-          _2 = move _3 as &[u32] (PointerCoercion(Unsize, AsCast));
-          StorageDead(_3);
-          StorageLive(_6);
-          _6 = const 1_usize;
--         _7 = Len((*_2));
--         _8 = Lt(copy _6, copy _7);
--         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind continue];
-+         _7 = const 3_usize;
-+         _8 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb1, unwind continue];
-      }
-  
-      bb1: {
--         _1 = copy (*_2)[_6];
-+         _1 = copy (*_2)[1 of 2];
-          StorageDead(_6);
-          StorageDead(_4);
-          StorageDead(_2);
-          StorageLive(_9);
-          StorageLive(_10);
-          _10 = const main::SLICE;
-          StorageLive(_11);
-          _11 = const 1_usize;
--         _12 = Len((*_10));
--         _13 = Lt(copy _11, copy _12);
--         assert(move _13, "index out of bounds: the length is {} but the index is {}", move _12, copy _11) -> [success: bb2, unwind continue];
-+         _12 = const 3_usize;
-+         _13 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb2, unwind continue];
-      }
-  
-      bb2: {
--         _9 = copy (*_10)[_11];
-+         _9 = copy (*_10)[1 of 2];
-          StorageDead(_11);
-          StorageDead(_10);
-          _0 = const ();
-          StorageDead(_9);
-          StorageDead(_1);
-          return;
-      }
-  }
-  

tests/mir-opt/dataflow-const-prop/slice_len.rs

@@ -1,34 +0,0 @@
-// EMIT_MIR_FOR_EACH_PANIC_STRATEGY
-//@ test-mir-pass: DataflowConstProp
-//@ compile-flags: -Zmir-enable-passes=+InstSimplify-after-simplifycfg
-// EMIT_MIR_FOR_EACH_BIT_WIDTH
-
-// EMIT_MIR slice_len.main.DataflowConstProp.diff
-
-// CHECK-LABEL: fn main(
-fn main() {
-    // CHECK: debug local => [[local:_.*]];
-    // CHECK: debug constant => [[constant:_.*]];
-
-    // CHECK-NOT: {{_.*}} = Len(
-    // CHECK-NOT: {{_.*}} = Lt(
-    // CHECK-NOT: assert(move _
-    // CHECK: {{_.*}} = const 3_usize;
-    // CHECK: {{_.*}} = const true;
-    // CHECK: assert(const true,
-
-    // CHECK: [[local]] = copy (*{{_.*}})[1 of 2];
-    let local = (&[1u32, 2, 3] as &[u32])[1];
-
-    // CHECK-NOT: {{_.*}} = Len(
-    // CHECK-NOT: {{_.*}} = Lt(
-    // CHECK-NOT: assert(move _
-    const SLICE: &[u32] = &[1, 2, 3];
-    // CHECK: {{_.*}} = const 3_usize;
-    // CHECK: {{_.*}} = const true;
-    // CHECK: assert(const true,
-
-    // CHECK-NOT: [[constant]] = {{copy|move}} (*{{_.*}})[_
-    // CHECK: [[constant]] = copy (*{{_.*}})[1 of 2];
-    let constant = SLICE[1];
-}

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

@@ -53,7 +53,7 @@
           StorageLive(_8);
 -         _8 = copy _2;
 +         _8 = const usize::MAX;
-          _9 = Len((*_1));
+          _9 = PtrMetadata(copy _1);
 -         _10 = Lt(copy _8, copy _9);
 -         assert(move _10, "index out of bounds: the length is {} but the index is {}", move _9, copy _8) -> [success: bb3, unwind unreachable];
 +         _10 = Lt(const usize::MAX, copy _9);
@@ -72,7 +72,7 @@
           StorageDead(_5);
           StorageLive(_11);
           _11 = const 0_usize;
-          _12 = Len((*_1));
+          _12 = PtrMetadata(copy _1);
 -         _13 = Lt(copy _11, copy _12);
 -         assert(move _13, "index out of bounds: the length is {} but the index is {}", move _12, copy _11) -> [success: bb5, unwind unreachable];
 +         _13 = Lt(const 0_usize, copy _12);

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

@@ -53,7 +53,7 @@
           StorageLive(_8);
 -         _8 = copy _2;
 +         _8 = const usize::MAX;
-          _9 = Len((*_1));
+          _9 = PtrMetadata(copy _1);
 -         _10 = Lt(copy _8, copy _9);
 -         assert(move _10, "index out of bounds: the length is {} but the index is {}", move _9, copy _8) -> [success: bb3, unwind continue];
 +         _10 = Lt(const usize::MAX, copy _9);
@@ -72,7 +72,7 @@
           StorageDead(_5);
           StorageLive(_11);
           _11 = const 0_usize;
-          _12 = Len((*_1));
+          _12 = PtrMetadata(copy _1);
 -         _13 = Lt(copy _11, copy _12);
 -         assert(move _13, "index out of bounds: the length is {} but the index is {}", move _12, copy _11) -> [success: bb5, unwind continue];
 +         _13 = Lt(const 0_usize, copy _12);

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

@@ -0,0 +1,72 @@
+- // MIR for `dedup_multiple_bounds_checks_lengths` before GVN
++ // MIR for `dedup_multiple_bounds_checks_lengths` after GVN
+  
+  fn dedup_multiple_bounds_checks_lengths(_1: &[i32]) -> [i32; 3] {
+      debug x => _1;
+      let mut _0: [i32; 3];
+      let mut _2: i32;
+      let _3: usize;
+      let mut _4: usize;
+      let mut _5: bool;
+      let mut _6: i32;
+      let _7: usize;
+      let mut _8: usize;
+      let mut _9: bool;
+      let mut _10: i32;
+      let _11: usize;
+      let mut _12: usize;
+      let mut _13: bool;
+  
+      bb0: {
+          StorageLive(_2);
+          StorageLive(_3);
+          _3 = const 42_usize;
+          _4 = PtrMetadata(copy _1);
+-         _5 = Lt(copy _3, copy _4);
+-         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind unreachable];
++         _5 = Lt(const 42_usize, copy _4);
++         assert(move _5, "index out of bounds: the length is {} but the index is {}", copy _4, const 42_usize) -> [success: bb1, unwind unreachable];
+      }
+  
+      bb1: {
+-         _2 = copy (*_1)[_3];
++         _2 = copy (*_1)[42 of 43];
+          StorageLive(_6);
+          StorageLive(_7);
+          _7 = const 13_usize;
+-         _8 = PtrMetadata(copy _1);
+-         _9 = Lt(copy _7, copy _8);
+-         assert(move _9, "index out of bounds: the length is {} but the index is {}", move _8, copy _7) -> [success: bb2, unwind unreachable];
++         _8 = copy _4;
++         _9 = Lt(const 13_usize, copy _4);
++         assert(move _9, "index out of bounds: the length is {} but the index is {}", copy _4, const 13_usize) -> [success: bb2, unwind unreachable];
+      }
+  
+      bb2: {
+-         _6 = copy (*_1)[_7];
++         _6 = copy (*_1)[13 of 14];
+          StorageLive(_10);
+          StorageLive(_11);
+          _11 = const 7_usize;
+-         _12 = PtrMetadata(copy _1);
+-         _13 = Lt(copy _11, copy _12);
+-         assert(move _13, "index out of bounds: the length is {} but the index is {}", move _12, copy _11) -> [success: bb3, unwind unreachable];
++         _12 = copy _4;
++         _13 = Lt(const 7_usize, copy _4);
++         assert(move _13, "index out of bounds: the length is {} but the index is {}", copy _4, const 7_usize) -> [success: bb3, unwind unreachable];
+      }
+  
+      bb3: {
+-         _10 = copy (*_1)[_11];
++         _10 = copy (*_1)[7 of 8];
+          _0 = [move _2, move _6, move _10];
+          StorageDead(_10);
+          StorageDead(_6);
+          StorageDead(_2);
+          StorageDead(_11);
+          StorageDead(_7);
+          StorageDead(_3);
+          return;
+      }
+  }
+  

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

@@ -0,0 +1,72 @@
+- // MIR for `dedup_multiple_bounds_checks_lengths` before GVN
++ // MIR for `dedup_multiple_bounds_checks_lengths` after GVN
+  
+  fn dedup_multiple_bounds_checks_lengths(_1: &[i32]) -> [i32; 3] {
+      debug x => _1;
+      let mut _0: [i32; 3];
+      let mut _2: i32;
+      let _3: usize;
+      let mut _4: usize;
+      let mut _5: bool;
+      let mut _6: i32;
+      let _7: usize;
+      let mut _8: usize;
+      let mut _9: bool;
+      let mut _10: i32;
+      let _11: usize;
+      let mut _12: usize;
+      let mut _13: bool;
+  
+      bb0: {
+          StorageLive(_2);
+          StorageLive(_3);
+          _3 = const 42_usize;
+          _4 = PtrMetadata(copy _1);
+-         _5 = Lt(copy _3, copy _4);
+-         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind continue];
++         _5 = Lt(const 42_usize, copy _4);
++         assert(move _5, "index out of bounds: the length is {} but the index is {}", copy _4, const 42_usize) -> [success: bb1, unwind continue];
+      }
+  
+      bb1: {
+-         _2 = copy (*_1)[_3];
++         _2 = copy (*_1)[42 of 43];
+          StorageLive(_6);
+          StorageLive(_7);
+          _7 = const 13_usize;
+-         _8 = PtrMetadata(copy _1);
+-         _9 = Lt(copy _7, copy _8);
+-         assert(move _9, "index out of bounds: the length is {} but the index is {}", move _8, copy _7) -> [success: bb2, unwind continue];
++         _8 = copy _4;
++         _9 = Lt(const 13_usize, copy _4);
++         assert(move _9, "index out of bounds: the length is {} but the index is {}", copy _4, const 13_usize) -> [success: bb2, unwind continue];
+      }
+  
+      bb2: {
+-         _6 = copy (*_1)[_7];
++         _6 = copy (*_1)[13 of 14];
+          StorageLive(_10);
+          StorageLive(_11);
+          _11 = const 7_usize;
+-         _12 = PtrMetadata(copy _1);
+-         _13 = Lt(copy _11, copy _12);
+-         assert(move _13, "index out of bounds: the length is {} but the index is {}", move _12, copy _11) -> [success: bb3, unwind continue];
++         _12 = copy _4;
++         _13 = Lt(const 7_usize, copy _4);
++         assert(move _13, "index out of bounds: the length is {} but the index is {}", copy _4, const 7_usize) -> [success: bb3, unwind continue];
+      }
+  
+      bb3: {
+-         _10 = copy (*_1)[_11];
++         _10 = copy (*_1)[7 of 8];
+          _0 = [move _2, move _6, move _10];
+          StorageDead(_10);
+          StorageDead(_6);
+          StorageDead(_2);
+          StorageDead(_11);
+          StorageDead(_7);
+          StorageDead(_3);
+          return;
+      }
+  }
+  

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

@@ -10,13 +10,11 @@
       let _5: ();
       let mut _6: T;
       let _7: usize;
-      let mut _8: usize;
-      let mut _9: bool;
-      let _10: ();
-      let mut _11: T;
-      let _12: usize;
-      let mut _13: usize;
-      let mut _14: bool;
+      let mut _8: bool;
+      let _9: ();
+      let mut _10: T;
+      let _11: usize;
+      let mut _12: bool;
       scope 1 {
           debug a => _3;
       }
@@ -32,12 +30,10 @@
           StorageLive(_6);
           StorageLive(_7);
           _7 = const 0_usize;
--         _8 = Len(_3);
--         _9 = Lt(copy _7, copy _8);
--         assert(move _9, "index out of bounds: the length is {} but the index is {}", move _8, copy _7) -> [success: bb1, unwind unreachable];
-+         _8 = const N;
-+         _9 = Lt(const 0_usize, const N);
-+         assert(move _9, "index out of bounds: the length is {} but the index is {}", const N, const 0_usize) -> [success: bb1, unwind unreachable];
+-         _8 = Lt(copy _7, const N);
+-         assert(move _8, "index out of bounds: the length is {} but the index is {}", const N, copy _7) -> [success: bb1, unwind unreachable];
++         _8 = Lt(const 0_usize, const N);
++         assert(move _8, "index out of bounds: the length is {} but the index is {}", const N, const 0_usize) -> [success: bb1, unwind unreachable];
       }
   
       bb1: {
@@ -51,29 +47,27 @@
           StorageDead(_6);
           StorageDead(_7);
           StorageDead(_5);
+          StorageLive(_9);
           StorageLive(_10);
           StorageLive(_11);
-          StorageLive(_12);
-          _12 = copy _2;
--         _13 = Len(_3);
--         _14 = Lt(copy _12, copy _13);
--         assert(move _14, "index out of bounds: the length is {} but the index is {}", move _13, copy _12) -> [success: bb3, unwind unreachable];
-+         _13 = const N;
-+         _14 = Lt(copy _2, const N);
-+         assert(move _14, "index out of bounds: the length is {} but the index is {}", const N, copy _2) -> [success: bb3, unwind unreachable];
+          _11 = copy _2;
+-         _12 = Lt(copy _11, const N);
+-         assert(move _12, "index out of bounds: the length is {} but the index is {}", const N, copy _11) -> [success: bb3, unwind unreachable];
++         _12 = Lt(copy _2, const N);
++         assert(move _12, "index out of bounds: the length is {} but the index is {}", const N, copy _2) -> [success: bb3, unwind unreachable];
       }
   
       bb3: {
--         _11 = copy _3[_12];
--         _10 = opaque::<T>(move _11) -> [return: bb4, unwind unreachable];
-+         _11 = copy _1;
-+         _10 = opaque::<T>(copy _1) -> [return: bb4, unwind unreachable];
+-         _10 = copy _3[_11];
+-         _9 = opaque::<T>(move _10) -> [return: bb4, unwind unreachable];
++         _10 = copy _1;
++         _9 = opaque::<T>(copy _1) -> [return: bb4, unwind unreachable];
       }
   
       bb4: {
-          StorageDead(_11);
-          StorageDead(_12);
           StorageDead(_10);
+          StorageDead(_11);
+          StorageDead(_9);
           _0 = const ();
           StorageDead(_3);
           return;

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

@@ -10,13 +10,11 @@
       let _5: ();
       let mut _6: T;
       let _7: usize;
-      let mut _8: usize;
-      let mut _9: bool;
-      let _10: ();
-      let mut _11: T;
-      let _12: usize;
-      let mut _13: usize;
-      let mut _14: bool;
+      let mut _8: bool;
+      let _9: ();
+      let mut _10: T;
+      let _11: usize;
+      let mut _12: bool;
       scope 1 {
           debug a => _3;
       }
@@ -32,12 +30,10 @@
           StorageLive(_6);
           StorageLive(_7);
           _7 = const 0_usize;
--         _8 = Len(_3);
--         _9 = Lt(copy _7, copy _8);
--         assert(move _9, "index out of bounds: the length is {} but the index is {}", move _8, copy _7) -> [success: bb1, unwind continue];
-+         _8 = const N;
-+         _9 = Lt(const 0_usize, const N);
-+         assert(move _9, "index out of bounds: the length is {} but the index is {}", const N, const 0_usize) -> [success: bb1, unwind continue];
+-         _8 = Lt(copy _7, const N);
+-         assert(move _8, "index out of bounds: the length is {} but the index is {}", const N, copy _7) -> [success: bb1, unwind continue];
++         _8 = Lt(const 0_usize, const N);
++         assert(move _8, "index out of bounds: the length is {} but the index is {}", const N, const 0_usize) -> [success: bb1, unwind continue];
       }
   
       bb1: {
@@ -51,29 +47,27 @@
           StorageDead(_6);
           StorageDead(_7);
           StorageDead(_5);
+          StorageLive(_9);
           StorageLive(_10);
           StorageLive(_11);
-          StorageLive(_12);
-          _12 = copy _2;
--         _13 = Len(_3);
--         _14 = Lt(copy _12, copy _13);
--         assert(move _14, "index out of bounds: the length is {} but the index is {}", move _13, copy _12) -> [success: bb3, unwind continue];
-+         _13 = const N;
-+         _14 = Lt(copy _2, const N);
-+         assert(move _14, "index out of bounds: the length is {} but the index is {}", const N, copy _2) -> [success: bb3, unwind continue];
+          _11 = copy _2;
+-         _12 = Lt(copy _11, const N);
+-         assert(move _12, "index out of bounds: the length is {} but the index is {}", const N, copy _11) -> [success: bb3, unwind continue];
++         _12 = Lt(copy _2, const N);
++         assert(move _12, "index out of bounds: the length is {} but the index is {}", const N, copy _2) -> [success: bb3, unwind continue];
       }
   
       bb3: {
--         _11 = copy _3[_12];
--         _10 = opaque::<T>(move _11) -> [return: bb4, unwind continue];
-+         _11 = copy _1;
-+         _10 = opaque::<T>(copy _1) -> [return: bb4, unwind continue];
+-         _10 = copy _3[_11];
+-         _9 = opaque::<T>(move _10) -> [return: bb4, unwind continue];
++         _10 = copy _1;
++         _9 = opaque::<T>(copy _1) -> [return: bb4, unwind continue];
       }
   
       bb4: {
-          StorageDead(_11);
-          StorageDead(_12);
           StorageDead(_10);
+          StorageDead(_11);
+          StorageDead(_9);
           _0 = const ();
           StorageDead(_3);
           return;

tests/mir-opt/gvn.rs

@@ -835,6 +835,25 @@ fn array_len(x: &mut [i32; 42]) -> usize {
     std::intrinsics::ptr_metadata(x)
 }
 
+// Check that we only load the length once, rather than all 3 times.
+fn dedup_multiple_bounds_checks_lengths(x: &[i32]) -> [i32; 3] {
+    // CHECK-LABEL: fn dedup_multiple_bounds_checks_lengths
+    // CHECK: [[LEN:_.+]] = PtrMetadata(copy _1);
+    // CHECK: Lt(const 42_usize, copy [[LEN]]);
+    // CHECK: assert{{.+}}copy [[LEN]]
+    // CHECK: [[A:_.+]] = copy (*_1)[42 of 43];
+    // CHECK-NOT: PtrMetadata
+    // CHECK: Lt(const 13_usize, copy [[LEN]]);
+    // CHECK: assert{{.+}}copy [[LEN]]
+    // CHECK: [[B:_.+]] = copy (*_1)[13 of 14];
+    // CHECK-NOT: PtrMetadata
+    // CHECK: Lt(const 7_usize, copy [[LEN]]);
+    // CHECK: assert{{.+}}copy [[LEN]]
+    // CHECK: [[C:_.+]] = copy (*_1)[7 of 8];
+    // CHECK: _0 = [move [[A]], move [[B]], move [[C]]]
+    [x[42], x[13], x[7]]
+}
+
 #[custom_mir(dialect = "runtime")]
 fn generic_cast_metadata<T, A: ?Sized, B: ?Sized>(ps: *const [T], pa: *const A, pb: *const B) {
     // CHECK-LABEL: fn generic_cast_metadata
@@ -1109,6 +1128,7 @@ enum Never {}
 // EMIT_MIR gvn.casts_before_aggregate_raw_ptr.GVN.diff
 // EMIT_MIR gvn.manual_slice_mut_len.GVN.diff
 // EMIT_MIR gvn.array_len.GVN.diff
+// EMIT_MIR gvn.dedup_multiple_bounds_checks_lengths.GVN.diff
 // EMIT_MIR gvn.generic_cast_metadata.GVN.diff
 // EMIT_MIR gvn.cast_pointer_eq.GVN.diff
 // EMIT_MIR gvn.aggregate_struct_then_transmute.GVN.diff

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

@@ -10,62 +10,60 @@
       let mut _6: &i32;
       let _7: &i32;
       let _8: usize;
-      let mut _9: usize;
-      let mut _10: bool;
-      let mut _12: *const dyn std::marker::Send;
-      let _13: &dyn std::marker::Send;
-      let mut _14: &i32;
-      let _15: &i32;
-      let _16: usize;
-      let mut _17: usize;
+      let mut _9: bool;
+      let mut _11: *const dyn std::marker::Send;
+      let _12: &dyn std::marker::Send;
+      let mut _13: &i32;
+      let _14: &i32;
+      let _15: usize;
+      let mut _16: bool;
+      let _17: ();
       let mut _18: bool;
-      let _19: ();
-      let mut _20: bool;
+      let mut _19: *const dyn std::marker::Send;
+      let mut _20: *const dyn std::marker::Send;
       let mut _21: *const dyn std::marker::Send;
-      let mut _22: *const dyn std::marker::Send;
-      let mut _23: *const dyn std::marker::Send;
-      let _24: ();
-      let mut _25: bool;
+      let _22: ();
+      let mut _23: bool;
+      let mut _24: *const dyn std::marker::Send;
+      let mut _25: *const dyn std::marker::Send;
       let mut _26: *const dyn std::marker::Send;
-      let mut _27: *const dyn std::marker::Send;
-      let mut _28: *const dyn std::marker::Send;
-      let _29: ();
-      let mut _30: bool;
+      let _27: ();
+      let mut _28: bool;
+      let mut _29: *const dyn std::marker::Send;
+      let mut _30: *const dyn std::marker::Send;
       let mut _31: *const dyn std::marker::Send;
-      let mut _32: *const dyn std::marker::Send;
-      let mut _33: *const dyn std::marker::Send;
-      let _34: ();
-      let mut _35: bool;
+      let _32: ();
+      let mut _33: bool;
+      let mut _34: *const dyn std::marker::Send;
+      let mut _35: *const dyn std::marker::Send;
       let mut _36: *const dyn std::marker::Send;
-      let mut _37: *const dyn std::marker::Send;
-      let mut _38: *const dyn std::marker::Send;
-      let _39: ();
-      let mut _40: bool;
+      let _37: ();
+      let mut _38: bool;
+      let mut _39: *const dyn std::marker::Send;
+      let mut _40: *const dyn std::marker::Send;
       let mut _41: *const dyn std::marker::Send;
-      let mut _42: *const dyn std::marker::Send;
-      let mut _43: *const dyn std::marker::Send;
-      let _44: ();
-      let mut _45: bool;
+      let _42: ();
+      let mut _43: bool;
+      let mut _44: *const dyn std::marker::Send;
+      let mut _45: *const dyn std::marker::Send;
       let mut _46: *const dyn std::marker::Send;
-      let mut _47: *const dyn std::marker::Send;
-      let mut _48: *const dyn std::marker::Send;
-      let mut _49: &[i32; 2];
+      let mut _47: &[i32; 2];
       scope 1 {
           debug slice => _1;
           let _3: *const dyn std::marker::Send;
           scope 2 {
               debug a => _3;
-              let _11: *const dyn std::marker::Send;
+              let _10: *const dyn std::marker::Send;
               scope 3 {
-                  debug b => _11;
+                  debug b => _10;
               }
           }
       }
   
       bb0: {
           StorageLive(_1);
-          _49 = const wide_ptr_same_provenance::promoted[0];
-          _1 = &(*_49);
+          _47 = const wide_ptr_same_provenance::promoted[0];
+          _1 = &(*_47);
           StorageLive(_3);
 -         StorageLive(_4);
 +         nop;
@@ -74,11 +72,9 @@
           StorageLive(_7);
           StorageLive(_8);
           _8 = const 0_usize;
--         _9 = Len((*_1));
--         _10 = Lt(copy _8, copy _9);
--         assert(move _10, "index out of bounds: the length is {} but the index is {}", move _9, copy _8) -> [success: bb1, unwind unreachable];
-+         _9 = const 2_usize;
-+         _10 = const true;
+-         _9 = Lt(copy _8, const 2_usize);
+-         assert(move _9, "index out of bounds: the length is {} but the index is {}", const 2_usize, copy _8) -> [success: bb1, unwind unreachable];
++         _9 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 2_usize, const 0_usize) -> [success: bb1, unwind unreachable];
       }
   
@@ -95,170 +91,168 @@
 +         nop;
           StorageDead(_7);
           StorageDead(_5);
-          StorageLive(_11);
--         StorageLive(_12);
+          StorageLive(_10);
+-         StorageLive(_11);
 +         nop;
+          StorageLive(_12);
           StorageLive(_13);
           StorageLive(_14);
           StorageLive(_15);
-          StorageLive(_16);
-          _16 = const 1_usize;
--         _17 = Len((*_1));
--         _18 = Lt(copy _16, copy _17);
--         assert(move _18, "index out of bounds: the length is {} but the index is {}", move _17, copy _16) -> [success: bb2, unwind unreachable];
-+         _17 = const 2_usize;
-+         _18 = const true;
+          _15 = const 1_usize;
+-         _16 = Lt(copy _15, const 2_usize);
+-         assert(move _16, "index out of bounds: the length is {} but the index is {}", const 2_usize, copy _15) -> [success: bb2, unwind unreachable];
++         _16 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 2_usize, const 1_usize) -> [success: bb2, unwind unreachable];
       }
   
       bb2: {
--         _15 = &(*_1)[_16];
-+         _15 = &(*_1)[1 of 2];
-          _14 = &(*_15);
-          _13 = move _14 as &dyn std::marker::Send (PointerCoercion(Unsize, AsCast));
-          StorageDead(_14);
-          _12 = &raw const (*_13);
--         _11 = move _12 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
--         StorageDead(_12);
-+         _11 = copy _12;
-+         nop;
-          StorageDead(_15);
+-         _14 = &(*_1)[_15];
++         _14 = &(*_1)[1 of 2];
+          _13 = &(*_14);
+          _12 = move _13 as &dyn std::marker::Send (PointerCoercion(Unsize, AsCast));
           StorageDead(_13);
+          _11 = &raw const (*_12);
+-         _10 = move _11 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
+-         StorageDead(_11);
++         _10 = copy _11;
++         nop;
+          StorageDead(_14);
+          StorageDead(_12);
+          StorageLive(_17);
+          StorageLive(_18);
           StorageLive(_19);
+-         _19 = copy _3;
++         _19 = copy _4;
           StorageLive(_20);
           StorageLive(_21);
--         _21 = copy _3;
-+         _21 = copy _4;
-          StorageLive(_22);
-          StorageLive(_23);
--         _23 = copy _11;
--         _22 = move _23 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
-+         _23 = copy _12;
-+         _22 = copy _12;
-          StorageDead(_23);
--         _20 = Eq(move _21, move _22);
-+         _20 = Eq(copy _4, copy _12);
-          StorageDead(_22);
+-         _21 = copy _10;
+-         _20 = move _21 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
++         _21 = copy _11;
++         _20 = copy _11;
           StorageDead(_21);
-          _19 = opaque::<bool>(move _20) -> [return: bb3, unwind unreachable];
+-         _18 = Eq(move _19, move _20);
++         _18 = Eq(copy _4, copy _11);
+          StorageDead(_20);
+          StorageDead(_19);
+          _17 = opaque::<bool>(move _18) -> [return: bb3, unwind unreachable];
       }
   
       bb3: {
-          StorageDead(_20);
-          StorageDead(_19);
+          StorageDead(_18);
+          StorageDead(_17);
+          StorageLive(_22);
+          StorageLive(_23);
           StorageLive(_24);
+-         _24 = copy _3;
++         _24 = copy _4;
           StorageLive(_25);
           StorageLive(_26);
--         _26 = copy _3;
-+         _26 = copy _4;
-          StorageLive(_27);
-          StorageLive(_28);
--         _28 = copy _11;
--         _27 = move _28 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
-+         _28 = copy _12;
-+         _27 = copy _12;
-          StorageDead(_28);
--         _25 = Ne(move _26, move _27);
-+         _25 = Ne(copy _4, copy _12);
-          StorageDead(_27);
+-         _26 = copy _10;
+-         _25 = move _26 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
++         _26 = copy _11;
++         _25 = copy _11;
           StorageDead(_26);
-          _24 = opaque::<bool>(move _25) -> [return: bb4, unwind unreachable];
+-         _23 = Ne(move _24, move _25);
++         _23 = Ne(copy _4, copy _11);
+          StorageDead(_25);
+          StorageDead(_24);
+          _22 = opaque::<bool>(move _23) -> [return: bb4, unwind unreachable];
       }
   
       bb4: {
-          StorageDead(_25);
-          StorageDead(_24);
+          StorageDead(_23);
+          StorageDead(_22);
+          StorageLive(_27);
+          StorageLive(_28);
           StorageLive(_29);
+-         _29 = copy _3;
++         _29 = copy _4;
           StorageLive(_30);
           StorageLive(_31);
--         _31 = copy _3;
-+         _31 = copy _4;
-          StorageLive(_32);
-          StorageLive(_33);
--         _33 = copy _11;
--         _32 = move _33 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
-+         _33 = copy _12;
-+         _32 = copy _12;
-          StorageDead(_33);
--         _30 = Lt(move _31, move _32);
-+         _30 = Lt(copy _4, copy _12);
-          StorageDead(_32);
+-         _31 = copy _10;
+-         _30 = move _31 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
++         _31 = copy _11;
++         _30 = copy _11;
           StorageDead(_31);
-          _29 = opaque::<bool>(move _30) -> [return: bb5, unwind unreachable];
+-         _28 = Lt(move _29, move _30);
++         _28 = Lt(copy _4, copy _11);
+          StorageDead(_30);
+          StorageDead(_29);
+          _27 = opaque::<bool>(move _28) -> [return: bb5, unwind unreachable];
       }
   
       bb5: {
-          StorageDead(_30);
-          StorageDead(_29);
+          StorageDead(_28);
+          StorageDead(_27);
+          StorageLive(_32);
+          StorageLive(_33);
           StorageLive(_34);
+-         _34 = copy _3;
++         _34 = copy _4;
           StorageLive(_35);
           StorageLive(_36);
--         _36 = copy _3;
-+         _36 = copy _4;
-          StorageLive(_37);
-          StorageLive(_38);
--         _38 = copy _11;
--         _37 = move _38 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
-+         _38 = copy _12;
-+         _37 = copy _12;
-          StorageDead(_38);
--         _35 = Le(move _36, move _37);
-+         _35 = Le(copy _4, copy _12);
-          StorageDead(_37);
+-         _36 = copy _10;
+-         _35 = move _36 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
++         _36 = copy _11;
++         _35 = copy _11;
           StorageDead(_36);
-          _34 = opaque::<bool>(move _35) -> [return: bb6, unwind unreachable];
+-         _33 = Le(move _34, move _35);
++         _33 = Le(copy _4, copy _11);
+          StorageDead(_35);
+          StorageDead(_34);
+          _32 = opaque::<bool>(move _33) -> [return: bb6, unwind unreachable];
       }
   
       bb6: {
-          StorageDead(_35);
-          StorageDead(_34);
+          StorageDead(_33);
+          StorageDead(_32);
+          StorageLive(_37);
+          StorageLive(_38);
           StorageLive(_39);
+-         _39 = copy _3;
++         _39 = copy _4;
           StorageLive(_40);
           StorageLive(_41);
--         _41 = copy _3;
-+         _41 = copy _4;
-          StorageLive(_42);
-          StorageLive(_43);
--         _43 = copy _11;
--         _42 = move _43 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
-+         _43 = copy _12;
-+         _42 = copy _12;
-          StorageDead(_43);
--         _40 = Gt(move _41, move _42);
-+         _40 = Gt(copy _4, copy _12);
-          StorageDead(_42);
+-         _41 = copy _10;
+-         _40 = move _41 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
++         _41 = copy _11;
++         _40 = copy _11;
           StorageDead(_41);
-          _39 = opaque::<bool>(move _40) -> [return: bb7, unwind unreachable];
+-         _38 = Gt(move _39, move _40);
++         _38 = Gt(copy _4, copy _11);
+          StorageDead(_40);
+          StorageDead(_39);
+          _37 = opaque::<bool>(move _38) -> [return: bb7, unwind unreachable];
       }
   
       bb7: {
-          StorageDead(_40);
-          StorageDead(_39);
+          StorageDead(_38);
+          StorageDead(_37);
+          StorageLive(_42);
+          StorageLive(_43);
           StorageLive(_44);
+-         _44 = copy _3;
++         _44 = copy _4;
           StorageLive(_45);
           StorageLive(_46);
--         _46 = copy _3;
-+         _46 = copy _4;
-          StorageLive(_47);
-          StorageLive(_48);
--         _48 = copy _11;
--         _47 = move _48 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
-+         _48 = copy _12;
-+         _47 = copy _12;
-          StorageDead(_48);
--         _45 = Ge(move _46, move _47);
-+         _45 = Ge(copy _4, copy _12);
-          StorageDead(_47);
+-         _46 = copy _10;
+-         _45 = move _46 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
++         _46 = copy _11;
++         _45 = copy _11;
           StorageDead(_46);
-          _44 = opaque::<bool>(move _45) -> [return: bb8, unwind unreachable];
+-         _43 = Ge(move _44, move _45);
++         _43 = Ge(copy _4, copy _11);
+          StorageDead(_45);
+          StorageDead(_44);
+          _42 = opaque::<bool>(move _43) -> [return: bb8, unwind unreachable];
       }
   
       bb8: {
-          StorageDead(_45);
-          StorageDead(_44);
+          StorageDead(_43);
+          StorageDead(_42);
           _0 = const ();
-          StorageDead(_16);
-          StorageDead(_11);
+          StorageDead(_15);
+          StorageDead(_10);
           StorageDead(_8);
           StorageDead(_3);
           StorageDead(_1);

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

@@ -10,62 +10,60 @@
       let mut _6: &i32;
       let _7: &i32;
       let _8: usize;
-      let mut _9: usize;
-      let mut _10: bool;
-      let mut _12: *const dyn std::marker::Send;
-      let _13: &dyn std::marker::Send;
-      let mut _14: &i32;
-      let _15: &i32;
-      let _16: usize;
-      let mut _17: usize;
+      let mut _9: bool;
+      let mut _11: *const dyn std::marker::Send;
+      let _12: &dyn std::marker::Send;
+      let mut _13: &i32;
+      let _14: &i32;
+      let _15: usize;
+      let mut _16: bool;
+      let _17: ();
       let mut _18: bool;
-      let _19: ();
-      let mut _20: bool;
+      let mut _19: *const dyn std::marker::Send;
+      let mut _20: *const dyn std::marker::Send;
       let mut _21: *const dyn std::marker::Send;
-      let mut _22: *const dyn std::marker::Send;
-      let mut _23: *const dyn std::marker::Send;
-      let _24: ();
-      let mut _25: bool;
+      let _22: ();
+      let mut _23: bool;
+      let mut _24: *const dyn std::marker::Send;
+      let mut _25: *const dyn std::marker::Send;
       let mut _26: *const dyn std::marker::Send;
-      let mut _27: *const dyn std::marker::Send;
-      let mut _28: *const dyn std::marker::Send;
-      let _29: ();
-      let mut _30: bool;
+      let _27: ();
+      let mut _28: bool;
+      let mut _29: *const dyn std::marker::Send;
+      let mut _30: *const dyn std::marker::Send;
       let mut _31: *const dyn std::marker::Send;
-      let mut _32: *const dyn std::marker::Send;
-      let mut _33: *const dyn std::marker::Send;
-      let _34: ();
-      let mut _35: bool;
+      let _32: ();
+      let mut _33: bool;
+      let mut _34: *const dyn std::marker::Send;
+      let mut _35: *const dyn std::marker::Send;
       let mut _36: *const dyn std::marker::Send;
-      let mut _37: *const dyn std::marker::Send;
-      let mut _38: *const dyn std::marker::Send;
-      let _39: ();
-      let mut _40: bool;
+      let _37: ();
+      let mut _38: bool;
+      let mut _39: *const dyn std::marker::Send;
+      let mut _40: *const dyn std::marker::Send;
       let mut _41: *const dyn std::marker::Send;
-      let mut _42: *const dyn std::marker::Send;
-      let mut _43: *const dyn std::marker::Send;
-      let _44: ();
-      let mut _45: bool;
+      let _42: ();
+      let mut _43: bool;
+      let mut _44: *const dyn std::marker::Send;
+      let mut _45: *const dyn std::marker::Send;
       let mut _46: *const dyn std::marker::Send;
-      let mut _47: *const dyn std::marker::Send;
-      let mut _48: *const dyn std::marker::Send;
-      let mut _49: &[i32; 2];
+      let mut _47: &[i32; 2];
       scope 1 {
           debug slice => _1;
           let _3: *const dyn std::marker::Send;
           scope 2 {
               debug a => _3;
-              let _11: *const dyn std::marker::Send;
+              let _10: *const dyn std::marker::Send;
               scope 3 {
-                  debug b => _11;
+                  debug b => _10;
               }
           }
       }
   
       bb0: {
           StorageLive(_1);
-          _49 = const wide_ptr_same_provenance::promoted[0];
-          _1 = &(*_49);
+          _47 = const wide_ptr_same_provenance::promoted[0];
+          _1 = &(*_47);
           StorageLive(_3);
 -         StorageLive(_4);
 +         nop;
@@ -74,11 +72,9 @@
           StorageLive(_7);
           StorageLive(_8);
           _8 = const 0_usize;
--         _9 = Len((*_1));
--         _10 = Lt(copy _8, copy _9);
--         assert(move _10, "index out of bounds: the length is {} but the index is {}", move _9, copy _8) -> [success: bb1, unwind continue];
-+         _9 = const 2_usize;
-+         _10 = const true;
+-         _9 = Lt(copy _8, const 2_usize);
+-         assert(move _9, "index out of bounds: the length is {} but the index is {}", const 2_usize, copy _8) -> [success: bb1, unwind continue];
++         _9 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 2_usize, const 0_usize) -> [success: bb1, unwind continue];
       }
   
@@ -95,170 +91,168 @@
 +         nop;
           StorageDead(_7);
           StorageDead(_5);
-          StorageLive(_11);
--         StorageLive(_12);
+          StorageLive(_10);
+-         StorageLive(_11);
 +         nop;
+          StorageLive(_12);
           StorageLive(_13);
           StorageLive(_14);
           StorageLive(_15);
-          StorageLive(_16);
-          _16 = const 1_usize;
--         _17 = Len((*_1));
--         _18 = Lt(copy _16, copy _17);
--         assert(move _18, "index out of bounds: the length is {} but the index is {}", move _17, copy _16) -> [success: bb2, unwind continue];
-+         _17 = const 2_usize;
-+         _18 = const true;
+          _15 = const 1_usize;
+-         _16 = Lt(copy _15, const 2_usize);
+-         assert(move _16, "index out of bounds: the length is {} but the index is {}", const 2_usize, copy _15) -> [success: bb2, unwind continue];
++         _16 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 2_usize, const 1_usize) -> [success: bb2, unwind continue];
       }
   
       bb2: {
--         _15 = &(*_1)[_16];
-+         _15 = &(*_1)[1 of 2];
-          _14 = &(*_15);
-          _13 = move _14 as &dyn std::marker::Send (PointerCoercion(Unsize, AsCast));
-          StorageDead(_14);
-          _12 = &raw const (*_13);
--         _11 = move _12 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
--         StorageDead(_12);
-+         _11 = copy _12;
-+         nop;
-          StorageDead(_15);
+-         _14 = &(*_1)[_15];
++         _14 = &(*_1)[1 of 2];
+          _13 = &(*_14);
+          _12 = move _13 as &dyn std::marker::Send (PointerCoercion(Unsize, AsCast));
           StorageDead(_13);
+          _11 = &raw const (*_12);
+-         _10 = move _11 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
+-         StorageDead(_11);
++         _10 = copy _11;
++         nop;
+          StorageDead(_14);
+          StorageDead(_12);
+          StorageLive(_17);
+          StorageLive(_18);
           StorageLive(_19);
+-         _19 = copy _3;
++         _19 = copy _4;
           StorageLive(_20);
           StorageLive(_21);
--         _21 = copy _3;
-+         _21 = copy _4;
-          StorageLive(_22);
-          StorageLive(_23);
--         _23 = copy _11;
--         _22 = move _23 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
-+         _23 = copy _12;
-+         _22 = copy _12;
-          StorageDead(_23);
--         _20 = Eq(move _21, move _22);
-+         _20 = Eq(copy _4, copy _12);
-          StorageDead(_22);
+-         _21 = copy _10;
+-         _20 = move _21 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
++         _21 = copy _11;
++         _20 = copy _11;
           StorageDead(_21);
-          _19 = opaque::<bool>(move _20) -> [return: bb3, unwind continue];
+-         _18 = Eq(move _19, move _20);
++         _18 = Eq(copy _4, copy _11);
+          StorageDead(_20);
+          StorageDead(_19);
+          _17 = opaque::<bool>(move _18) -> [return: bb3, unwind continue];
       }
   
       bb3: {
-          StorageDead(_20);
-          StorageDead(_19);
+          StorageDead(_18);
+          StorageDead(_17);
+          StorageLive(_22);
+          StorageLive(_23);
           StorageLive(_24);
+-         _24 = copy _3;
++         _24 = copy _4;
           StorageLive(_25);
           StorageLive(_26);
--         _26 = copy _3;
-+         _26 = copy _4;
-          StorageLive(_27);
-          StorageLive(_28);
--         _28 = copy _11;
--         _27 = move _28 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
-+         _28 = copy _12;
-+         _27 = copy _12;
-          StorageDead(_28);
--         _25 = Ne(move _26, move _27);
-+         _25 = Ne(copy _4, copy _12);
-          StorageDead(_27);
+-         _26 = copy _10;
+-         _25 = move _26 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
++         _26 = copy _11;
++         _25 = copy _11;
           StorageDead(_26);
-          _24 = opaque::<bool>(move _25) -> [return: bb4, unwind continue];
+-         _23 = Ne(move _24, move _25);
++         _23 = Ne(copy _4, copy _11);
+          StorageDead(_25);
+          StorageDead(_24);
+          _22 = opaque::<bool>(move _23) -> [return: bb4, unwind continue];
       }
   
       bb4: {
-          StorageDead(_25);
-          StorageDead(_24);
+          StorageDead(_23);
+          StorageDead(_22);
+          StorageLive(_27);
+          StorageLive(_28);
           StorageLive(_29);
+-         _29 = copy _3;
++         _29 = copy _4;
           StorageLive(_30);
           StorageLive(_31);
--         _31 = copy _3;
-+         _31 = copy _4;
-          StorageLive(_32);
-          StorageLive(_33);
--         _33 = copy _11;
--         _32 = move _33 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
-+         _33 = copy _12;
-+         _32 = copy _12;
-          StorageDead(_33);
--         _30 = Lt(move _31, move _32);
-+         _30 = Lt(copy _4, copy _12);
-          StorageDead(_32);
+-         _31 = copy _10;
+-         _30 = move _31 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
++         _31 = copy _11;
++         _30 = copy _11;
           StorageDead(_31);
-          _29 = opaque::<bool>(move _30) -> [return: bb5, unwind continue];
+-         _28 = Lt(move _29, move _30);
++         _28 = Lt(copy _4, copy _11);
+          StorageDead(_30);
+          StorageDead(_29);
+          _27 = opaque::<bool>(move _28) -> [return: bb5, unwind continue];
       }
   
       bb5: {
-          StorageDead(_30);
-          StorageDead(_29);
+          StorageDead(_28);
+          StorageDead(_27);
+          StorageLive(_32);
+          StorageLive(_33);
           StorageLive(_34);
+-         _34 = copy _3;
++         _34 = copy _4;
           StorageLive(_35);
           StorageLive(_36);
--         _36 = copy _3;
-+         _36 = copy _4;
-          StorageLive(_37);
-          StorageLive(_38);
--         _38 = copy _11;
--         _37 = move _38 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
-+         _38 = copy _12;
-+         _37 = copy _12;
-          StorageDead(_38);
--         _35 = Le(move _36, move _37);
-+         _35 = Le(copy _4, copy _12);
-          StorageDead(_37);
+-         _36 = copy _10;
+-         _35 = move _36 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
++         _36 = copy _11;
++         _35 = copy _11;
           StorageDead(_36);
-          _34 = opaque::<bool>(move _35) -> [return: bb6, unwind continue];
+-         _33 = Le(move _34, move _35);
++         _33 = Le(copy _4, copy _11);
+          StorageDead(_35);
+          StorageDead(_34);
+          _32 = opaque::<bool>(move _33) -> [return: bb6, unwind continue];
       }
   
       bb6: {
-          StorageDead(_35);
-          StorageDead(_34);
+          StorageDead(_33);
+          StorageDead(_32);
+          StorageLive(_37);
+          StorageLive(_38);
           StorageLive(_39);
+-         _39 = copy _3;
++         _39 = copy _4;
           StorageLive(_40);
           StorageLive(_41);
--         _41 = copy _3;
-+         _41 = copy _4;
-          StorageLive(_42);
-          StorageLive(_43);
--         _43 = copy _11;
--         _42 = move _43 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
-+         _43 = copy _12;
-+         _42 = copy _12;
-          StorageDead(_43);
--         _40 = Gt(move _41, move _42);
-+         _40 = Gt(copy _4, copy _12);
-          StorageDead(_42);
+-         _41 = copy _10;
+-         _40 = move _41 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
++         _41 = copy _11;
++         _40 = copy _11;
           StorageDead(_41);
-          _39 = opaque::<bool>(move _40) -> [return: bb7, unwind continue];
+-         _38 = Gt(move _39, move _40);
++         _38 = Gt(copy _4, copy _11);
+          StorageDead(_40);
+          StorageDead(_39);
+          _37 = opaque::<bool>(move _38) -> [return: bb7, unwind continue];
       }
   
       bb7: {
-          StorageDead(_40);
-          StorageDead(_39);
+          StorageDead(_38);
+          StorageDead(_37);
+          StorageLive(_42);
+          StorageLive(_43);
           StorageLive(_44);
+-         _44 = copy _3;
++         _44 = copy _4;
           StorageLive(_45);
           StorageLive(_46);
--         _46 = copy _3;
-+         _46 = copy _4;
-          StorageLive(_47);
-          StorageLive(_48);
--         _48 = copy _11;
--         _47 = move _48 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
-+         _48 = copy _12;
-+         _47 = copy _12;
-          StorageDead(_48);
--         _45 = Ge(move _46, move _47);
-+         _45 = Ge(copy _4, copy _12);
-          StorageDead(_47);
+-         _46 = copy _10;
+-         _45 = move _46 as *const dyn std::marker::Send (PointerCoercion(Unsize, Implicit));
++         _46 = copy _11;
++         _45 = copy _11;
           StorageDead(_46);
-          _44 = opaque::<bool>(move _45) -> [return: bb8, unwind continue];
+-         _43 = Ge(move _44, move _45);
++         _43 = Ge(copy _4, copy _11);
+          StorageDead(_45);
+          StorageDead(_44);
+          _42 = opaque::<bool>(move _43) -> [return: bb8, unwind continue];
       }
   
       bb8: {
-          StorageDead(_45);
-          StorageDead(_44);
+          StorageDead(_43);
+          StorageDead(_42);
           _0 = const ();
-          StorageDead(_16);
-          StorageDead(_11);
+          StorageDead(_15);
+          StorageDead(_10);
           StorageDead(_8);
           StorageDead(_3);
           StorageDead(_1);

tests/mir-opt/instsimplify/combine_array_len.norm2.InstSimplify-after-simplifycfg.panic-abort.diff

@@ -1,77 +0,0 @@
-- // MIR for `norm2` before InstSimplify-after-simplifycfg
-+ // MIR for `norm2` after InstSimplify-after-simplifycfg
-  
-  fn norm2(_1: [f32; 2]) -> f32 {
-      debug x => _1;
-      let mut _0: f32;
-      let _2: f32;
-      let _3: usize;
-      let mut _4: usize;
-      let mut _5: bool;
-      let _7: usize;
-      let mut _8: usize;
-      let mut _9: bool;
-      let mut _10: f32;
-      let mut _11: f32;
-      let mut _12: f32;
-      let mut _13: f32;
-      let mut _14: f32;
-      let mut _15: f32;
-      scope 1 {
-          debug a => _2;
-          let _6: f32;
-          scope 2 {
-              debug b => _6;
-          }
-      }
-  
-      bb0: {
-          StorageLive(_2);
-          StorageLive(_3);
-          _3 = const 0_usize;
--         _4 = Len(_1);
-+         _4 = const 2_usize;
-          _5 = Lt(copy _3, copy _4);
-          assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind unreachable];
-      }
-  
-      bb1: {
-          _2 = copy _1[_3];
-          StorageDead(_3);
-          StorageLive(_6);
-          StorageLive(_7);
-          _7 = const 1_usize;
--         _8 = Len(_1);
-+         _8 = const 2_usize;
-          _9 = Lt(copy _7, copy _8);
-          assert(move _9, "index out of bounds: the length is {} but the index is {}", move _8, copy _7) -> [success: bb2, unwind unreachable];
-      }
-  
-      bb2: {
-          _6 = copy _1[_7];
-          StorageDead(_7);
-          StorageLive(_10);
-          StorageLive(_11);
-          _11 = copy _2;
-          StorageLive(_12);
-          _12 = copy _2;
-          _10 = Mul(move _11, move _12);
-          StorageDead(_12);
-          StorageDead(_11);
-          StorageLive(_13);
-          StorageLive(_14);
-          _14 = copy _6;
-          StorageLive(_15);
-          _15 = copy _6;
-          _13 = Mul(move _14, move _15);
-          StorageDead(_15);
-          StorageDead(_14);
-          _0 = Add(move _10, move _13);
-          StorageDead(_13);
-          StorageDead(_10);
-          StorageDead(_6);
-          StorageDead(_2);
-          return;
-      }
-  }
-  

tests/mir-opt/instsimplify/combine_array_len.norm2.InstSimplify-after-simplifycfg.panic-unwind.diff

@@ -1,77 +0,0 @@
-- // MIR for `norm2` before InstSimplify-after-simplifycfg
-+ // MIR for `norm2` after InstSimplify-after-simplifycfg
-  
-  fn norm2(_1: [f32; 2]) -> f32 {
-      debug x => _1;
-      let mut _0: f32;
-      let _2: f32;
-      let _3: usize;
-      let mut _4: usize;
-      let mut _5: bool;
-      let _7: usize;
-      let mut _8: usize;
-      let mut _9: bool;
-      let mut _10: f32;
-      let mut _11: f32;
-      let mut _12: f32;
-      let mut _13: f32;
-      let mut _14: f32;
-      let mut _15: f32;
-      scope 1 {
-          debug a => _2;
-          let _6: f32;
-          scope 2 {
-              debug b => _6;
-          }
-      }
-  
-      bb0: {
-          StorageLive(_2);
-          StorageLive(_3);
-          _3 = const 0_usize;
--         _4 = Len(_1);
-+         _4 = const 2_usize;
-          _5 = Lt(copy _3, copy _4);
-          assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind continue];
-      }
-  
-      bb1: {
-          _2 = copy _1[_3];
-          StorageDead(_3);
-          StorageLive(_6);
-          StorageLive(_7);
-          _7 = const 1_usize;
--         _8 = Len(_1);
-+         _8 = const 2_usize;
-          _9 = Lt(copy _7, copy _8);
-          assert(move _9, "index out of bounds: the length is {} but the index is {}", move _8, copy _7) -> [success: bb2, unwind continue];
-      }
-  
-      bb2: {
-          _6 = copy _1[_7];
-          StorageDead(_7);
-          StorageLive(_10);
-          StorageLive(_11);
-          _11 = copy _2;
-          StorageLive(_12);
-          _12 = copy _2;
-          _10 = Mul(move _11, move _12);
-          StorageDead(_12);
-          StorageDead(_11);
-          StorageLive(_13);
-          StorageLive(_14);
-          _14 = copy _6;
-          StorageLive(_15);
-          _15 = copy _6;
-          _13 = Mul(move _14, move _15);
-          StorageDead(_15);
-          StorageDead(_14);
-          _0 = Add(move _10, move _13);
-          StorageDead(_13);
-          StorageDead(_10);
-          StorageDead(_6);
-          StorageDead(_2);
-          return;
-      }
-  }
-  

tests/mir-opt/instsimplify/combine_array_len.rs

@@ -1,15 +0,0 @@
-// EMIT_MIR_FOR_EACH_PANIC_STRATEGY
-//@ test-mir-pass: InstSimplify-after-simplifycfg
-
-// EMIT_MIR combine_array_len.norm2.InstSimplify-after-simplifycfg.diff
-fn norm2(x: [f32; 2]) -> f32 {
-    // CHECK-LABEL: fn norm2(
-    // CHECK-NOT: Len(
-    let a = x[0];
-    let b = x[1];
-    a * a + b * b
-}
-
-fn main() {
-    assert_eq!(norm2([3.0, 4.0]), 5.0 * 5.0);
-}

tests/mir-opt/issue_72181.foo.built.after.mir

@@ -4,15 +4,14 @@ fn foo(_1: [(Never, u32); 1]) -> u32 {
     debug xs => _1;
     let mut _0: u32;
     let _2: usize;
-    let mut _3: usize;
-    let mut _4: bool;
+    let mut _3: bool;
 
     bb0: {
         StorageLive(_2);
         _2 = const 0_usize;
-        _3 = Len(_1);
-        _4 = Lt(copy _2, copy _3);
-        assert(move _4, "index out of bounds: the length is {} but the index is {}", move _3, copy _2) -> [success: bb1, unwind: bb2];
+        FakeRead(ForIndex, _1);
+        _3 = Lt(copy _2, const 1_usize);
+        assert(move _3, "index out of bounds: the length is {} but the index is {}", const 1_usize, copy _2) -> [success: bb1, unwind: bb2];
     }
 
     bb1: {

tests/mir-opt/issue_72181.main.built.after.mir

@@ -7,8 +7,7 @@ fn main() -> () {
     let mut _4: Foo;
     let mut _5: u64;
     let _6: usize;
-    let mut _7: usize;
-    let mut _8: bool;
+    let mut _7: bool;
     scope 1 {
         let _2: [Foo; 2];
         scope 2 {
@@ -38,9 +37,9 @@ fn main() -> () {
         StorageLive(_5);
         StorageLive(_6);
         _6 = const 0_usize;
-        _7 = Len(_2);
-        _8 = Lt(copy _6, copy _7);
-        assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb3, unwind: bb5];
+        FakeRead(ForIndex, _2);
+        _7 = Lt(copy _6, const 2_usize);
+        assert(move _7, "index out of bounds: the length is {} but the index is {}", const 2_usize, copy _6) -> [success: bb3, unwind: bb5];
     }
 
     bb2: {

tests/mir-opt/issue_91633.foo.built.after.mir

@@ -6,8 +6,9 @@ fn foo(_1: Box<[T]>) -> T {
     let _2: T;
     let mut _3: &T;
     let _4: usize;
-    let mut _5: usize;
-    let mut _6: bool;
+    let mut _5: *const [T];
+    let mut _6: usize;
+    let mut _7: bool;
     scope 1 {
         debug f => _2;
     }
@@ -17,9 +18,10 @@ fn foo(_1: Box<[T]>) -> T {
         StorageLive(_3);
         StorageLive(_4);
         _4 = const 0_usize;
-        _5 = Len((*_1));
-        _6 = Lt(copy _4, copy _5);
-        assert(move _6, "index out of bounds: the length is {} but the index is {}", move _5, copy _4) -> [success: bb1, unwind: bb5];
+        _5 = &raw const (fake) (*_1);
+        _6 = PtrMetadata(move _5);
+        _7 = Lt(copy _4, copy _6);
+        assert(move _7, "index out of bounds: the length is {} but the index is {}", move _6, copy _4) -> [success: bb1, unwind: bb5];
     }
 
     bb1: {

tests/mir-opt/issue_91633.fun.built.after.mir

@@ -15,7 +15,7 @@ fn fun(_1: &[T]) -> &T {
         StorageLive(_2);
         StorageLive(_3);
         _3 = const 0_usize;
-        _4 = Len((*_1));
+        _4 = PtrMetadata(copy _1);
         _5 = Lt(copy _3, copy _4);
         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind: bb2];
     }

tests/mir-opt/lower_array_len.array_bound.GVN.panic-abort.diff

@@ -11,16 +11,14 @@
       let mut _6: &[u8];
       let mut _7: &[u8; N];
       let _8: usize;
-      let mut _9: usize;
-      let mut _10: bool;
+      let mut _9: bool;
   
       bb0: {
 -         StorageLive(_3);
 +         nop;
           StorageLive(_4);
           _4 = copy _1;
--         StorageLive(_5);
-+         nop;
+          StorageLive(_5);
           StorageLive(_6);
           StorageLive(_7);
           _7 = &(*_2);
@@ -40,16 +38,13 @@
       }
   
       bb2: {
--         StorageDead(_5);
-+         nop;
+          StorageDead(_5);
           StorageDead(_4);
           StorageLive(_8);
           _8 = copy _1;
--         _9 = Len((*_2));
--         _10 = Lt(copy _8, copy _9);
--         assert(move _10, "index out of bounds: the length is {} but the index is {}", move _9, copy _8) -> [success: bb3, unwind unreachable];
-+         _9 = const N;
-+         _10 = copy _3;
+-         _9 = Lt(copy _8, const N);
+-         assert(move _9, "index out of bounds: the length is {} but the index is {}", const N, copy _8) -> [success: bb3, unwind unreachable];
++         _9 = copy _3;
 +         assert(copy _3, "index out of bounds: the length is {} but the index is {}", const N, copy _1) -> [success: bb3, unwind unreachable];
       }
   
@@ -61,8 +56,7 @@
       }
   
       bb4: {
--         StorageDead(_5);
-+         nop;
+          StorageDead(_5);
           StorageDead(_4);
           _0 = const 42_u8;
           goto -> bb5;

tests/mir-opt/lower_array_len.array_bound.GVN.panic-unwind.diff

@@ -11,16 +11,14 @@
       let mut _6: &[u8];
       let mut _7: &[u8; N];
       let _8: usize;
-      let mut _9: usize;
-      let mut _10: bool;
+      let mut _9: bool;
   
       bb0: {
 -         StorageLive(_3);
 +         nop;
           StorageLive(_4);
           _4 = copy _1;
--         StorageLive(_5);
-+         nop;
+          StorageLive(_5);
           StorageLive(_6);
           StorageLive(_7);
           _7 = &(*_2);
@@ -40,16 +38,13 @@
       }
   
       bb2: {
--         StorageDead(_5);
-+         nop;
+          StorageDead(_5);
           StorageDead(_4);
           StorageLive(_8);
           _8 = copy _1;
--         _9 = Len((*_2));
--         _10 = Lt(copy _8, copy _9);
--         assert(move _10, "index out of bounds: the length is {} but the index is {}", move _9, copy _8) -> [success: bb3, unwind continue];
-+         _9 = const N;
-+         _10 = copy _3;
+-         _9 = Lt(copy _8, const N);
+-         assert(move _9, "index out of bounds: the length is {} but the index is {}", const N, copy _8) -> [success: bb3, unwind continue];
++         _9 = copy _3;
 +         assert(copy _3, "index out of bounds: the length is {} but the index is {}", const N, copy _1) -> [success: bb3, unwind continue];
       }
   
@@ -61,8 +56,7 @@
       }
   
       bb4: {
--         StorageDead(_5);
-+         nop;
+          StorageDead(_5);
           StorageDead(_4);
           _0 = const 42_u8;
           goto -> bb5;

tests/mir-opt/lower_array_len.array_bound_mut.GVN.panic-abort.diff

@@ -11,19 +11,16 @@
       let mut _6: &[u8];
       let mut _7: &[u8; N];
       let _8: usize;
-      let mut _9: usize;
-      let mut _10: bool;
-      let _11: usize;
-      let mut _12: usize;
-      let mut _13: bool;
+      let mut _9: bool;
+      let _10: usize;
+      let mut _11: bool;
   
       bb0: {
 -         StorageLive(_3);
 +         nop;
           StorageLive(_4);
           _4 = copy _1;
--         StorageLive(_5);
-+         nop;
+          StorageLive(_5);
           StorageLive(_6);
           StorageLive(_7);
           _7 = &(*_2);
@@ -43,16 +40,13 @@
       }
   
       bb2: {
--         StorageDead(_5);
-+         nop;
+          StorageDead(_5);
           StorageDead(_4);
           StorageLive(_8);
           _8 = copy _1;
--         _9 = Len((*_2));
--         _10 = Lt(copy _8, copy _9);
--         assert(move _10, "index out of bounds: the length is {} but the index is {}", move _9, copy _8) -> [success: bb3, unwind unreachable];
-+         _9 = const N;
-+         _10 = copy _3;
+-         _9 = Lt(copy _8, const N);
+-         assert(move _9, "index out of bounds: the length is {} but the index is {}", const N, copy _8) -> [success: bb3, unwind unreachable];
++         _9 = copy _3;
 +         assert(copy _3, "index out of bounds: the length is {} but the index is {}", const N, copy _1) -> [success: bb3, unwind unreachable];
       }
   
@@ -64,23 +58,20 @@
       }
   
       bb4: {
--         StorageDead(_5);
-+         nop;
+          StorageDead(_5);
           StorageDead(_4);
-          StorageLive(_11);
-          _11 = const 0_usize;
--         _12 = Len((*_2));
--         _13 = Lt(copy _11, copy _12);
--         assert(move _13, "index out of bounds: the length is {} but the index is {}", move _12, copy _11) -> [success: bb5, unwind unreachable];
-+         _12 = const N;
-+         _13 = Lt(const 0_usize, const N);
-+         assert(move _13, "index out of bounds: the length is {} but the index is {}", const N, const 0_usize) -> [success: bb5, unwind unreachable];
+          StorageLive(_10);
+          _10 = const 0_usize;
+-         _11 = Lt(copy _10, const N);
+-         assert(move _11, "index out of bounds: the length is {} but the index is {}", const N, copy _10) -> [success: bb5, unwind unreachable];
++         _11 = Lt(const 0_usize, const N);
++         assert(move _11, "index out of bounds: the length is {} but the index is {}", const N, const 0_usize) -> [success: bb5, unwind unreachable];
       }
   
       bb5: {
--         (*_2)[_11] = const 42_u8;
+-         (*_2)[_10] = const 42_u8;
 +         (*_2)[0 of 1] = const 42_u8;
-          StorageDead(_11);
+          StorageDead(_10);
           _0 = const 42_u8;
           goto -> bb6;
       }

tests/mir-opt/lower_array_len.array_bound_mut.GVN.panic-unwind.diff

@@ -11,19 +11,16 @@
       let mut _6: &[u8];
       let mut _7: &[u8; N];
       let _8: usize;
-      let mut _9: usize;
-      let mut _10: bool;
-      let _11: usize;
-      let mut _12: usize;
-      let mut _13: bool;
+      let mut _9: bool;
+      let _10: usize;
+      let mut _11: bool;
   
       bb0: {
 -         StorageLive(_3);
 +         nop;
           StorageLive(_4);
           _4 = copy _1;
--         StorageLive(_5);
-+         nop;
+          StorageLive(_5);
           StorageLive(_6);
           StorageLive(_7);
           _7 = &(*_2);
@@ -43,16 +40,13 @@
       }
   
       bb2: {
--         StorageDead(_5);
-+         nop;
+          StorageDead(_5);
           StorageDead(_4);
           StorageLive(_8);
           _8 = copy _1;
--         _9 = Len((*_2));
--         _10 = Lt(copy _8, copy _9);
--         assert(move _10, "index out of bounds: the length is {} but the index is {}", move _9, copy _8) -> [success: bb3, unwind continue];
-+         _9 = const N;
-+         _10 = copy _3;
+-         _9 = Lt(copy _8, const N);
+-         assert(move _9, "index out of bounds: the length is {} but the index is {}", const N, copy _8) -> [success: bb3, unwind continue];
++         _9 = copy _3;
 +         assert(copy _3, "index out of bounds: the length is {} but the index is {}", const N, copy _1) -> [success: bb3, unwind continue];
       }
   
@@ -64,23 +58,20 @@
       }
   
       bb4: {
--         StorageDead(_5);
-+         nop;
+          StorageDead(_5);
           StorageDead(_4);
-          StorageLive(_11);
-          _11 = const 0_usize;
--         _12 = Len((*_2));
--         _13 = Lt(copy _11, copy _12);
--         assert(move _13, "index out of bounds: the length is {} but the index is {}", move _12, copy _11) -> [success: bb5, unwind continue];
-+         _12 = const N;
-+         _13 = Lt(const 0_usize, const N);
-+         assert(move _13, "index out of bounds: the length is {} but the index is {}", const N, const 0_usize) -> [success: bb5, unwind continue];
+          StorageLive(_10);
+          _10 = const 0_usize;
+-         _11 = Lt(copy _10, const N);
+-         assert(move _11, "index out of bounds: the length is {} but the index is {}", const N, copy _10) -> [success: bb5, unwind continue];
++         _11 = Lt(const 0_usize, const N);
++         assert(move _11, "index out of bounds: the length is {} but the index is {}", const N, const 0_usize) -> [success: bb5, unwind continue];
       }
   
       bb5: {
--         (*_2)[_11] = const 42_u8;
+-         (*_2)[_10] = const 42_u8;
 +         (*_2)[0 of 1] = const 42_u8;
-          StorageDead(_11);
+          StorageDead(_10);
           _0 = const 42_u8;
           goto -> bb6;
       }

tests/mir-opt/lower_slice_len.bound.LowerSliceLenCalls.panic-abort.diff

@@ -36,7 +36,7 @@
           StorageDead(_4);
           StorageLive(_7);
           _7 = copy _1;
-          _8 = Len((*_2));
+          _8 = PtrMetadata(copy _2);
           _9 = Lt(copy _7, copy _8);
           assert(move _9, "index out of bounds: the length is {} but the index is {}", move _8, copy _7) -> [success: bb3, unwind unreachable];
       }

tests/mir-opt/lower_slice_len.bound.LowerSliceLenCalls.panic-unwind.diff

@@ -36,7 +36,7 @@
           StorageDead(_4);
           StorageLive(_7);
           _7 = copy _1;
-          _8 = Len((*_2));
+          _8 = PtrMetadata(copy _2);
           _9 = Lt(copy _7, copy _8);
           assert(move _9, "index out of bounds: the length is {} but the index is {}", move _8, copy _7) -> [success: bb3, unwind continue];
       }

tests/mir-opt/nll/region_subtyping_basic.main.nll.0.32bit.mir

@@ -27,20 +27,19 @@ fn main() -> () {
     let mut _0: ();
     let mut _1: [usize; ValTree(Leaf(0x00000003): usize)];
     let _3: usize;
-    let mut _4: usize;
-    let mut _5: bool;
-    let mut _7: bool;
-    let _8: bool;
-    let mut _9: usize;
-    let _10: bool;
+    let mut _4: bool;
+    let mut _6: bool;
+    let _7: bool;
+    let mut _8: usize;
+    let _9: bool;
     scope 1 {
         debug v => _1;
         let _2: &'?3 usize;
         scope 2 {
             debug p => _2;
-            let _6: &'?4 usize;
+            let _5: &'?4 usize;
             scope 3 {
-                debug q => _6;
+                debug q => _5;
             }
         }
     }
@@ -52,50 +51,50 @@ fn main() -> () {
         StorageLive(_2);
         StorageLive(_3);
         _3 = const ConstValue(Scalar(0x00000000): usize);
-        _4 = Len(_1);
-        _5 = Lt(copy _3, copy _4);
-        assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind: bb7];
+        FakeRead(ForIndex, _1);
+        _4 = Lt(copy _3, const ValTree(Leaf(0x00000003): usize));
+        assert(move _4, "index out of bounds: the length is {} but the index is {}", const ValTree(Leaf(0x00000003): usize), copy _3) -> [success: bb1, unwind: bb7];
     }
 
     bb1: {
         _2 = &'?2 _1[_3];
         FakeRead(ForLet(None), _2);
+        StorageLive(_5);
+        _5 = copy _2;
+        FakeRead(ForLet(None), _5);
         StorageLive(_6);
-        _6 = copy _2;
-        FakeRead(ForLet(None), _6);
-        StorageLive(_7);
-        _7 = const ConstValue(Scalar(0x01): bool);
-        switchInt(move _7) -> [0: bb4, otherwise: bb2];
+        _6 = const ConstValue(Scalar(0x01): bool);
+        switchInt(move _6) -> [0: bb4, otherwise: bb2];
     }
 
     bb2: {
+        StorageLive(_7);
         StorageLive(_8);
-        StorageLive(_9);
-        _9 = copy (*_6);
-        _8 = ConstValue(ZeroSized: fn(usize) -> bool {use_x})(move _9) -> [return: bb3, unwind: bb7];
+        _8 = copy (*_5);
+        _7 = ConstValue(ZeroSized: fn(usize) -> bool {use_x})(move _8) -> [return: bb3, unwind: bb7];
     }
 
     bb3: {
-        StorageDead(_9);
         StorageDead(_8);
+        StorageDead(_7);
         _0 = const ConstValue(ZeroSized: ());
         goto -> bb6;
     }
 
     bb4: {
-        StorageLive(_10);
-        _10 = ConstValue(ZeroSized: fn(usize) -> bool {use_x})(const ConstValue(Scalar(0x00000016): usize)) -> [return: bb5, unwind: bb7];
+        StorageLive(_9);
+        _9 = ConstValue(ZeroSized: fn(usize) -> bool {use_x})(const ConstValue(Scalar(0x00000016): usize)) -> [return: bb5, unwind: bb7];
     }
 
     bb5: {
-        StorageDead(_10);
+        StorageDead(_9);
         _0 = const ConstValue(ZeroSized: ());
         goto -> bb6;
     }
 
     bb6: {
-        StorageDead(_7);
         StorageDead(_6);
+        StorageDead(_5);
         StorageDead(_3);
         StorageDead(_2);
         StorageDead(_1);

tests/mir-opt/nll/region_subtyping_basic.main.nll.0.64bit.mir

@@ -27,20 +27,19 @@ fn main() -> () {
     let mut _0: ();
     let mut _1: [usize; ValTree(Leaf(0x0000000000000003): usize)];
     let _3: usize;
-    let mut _4: usize;
-    let mut _5: bool;
-    let mut _7: bool;
-    let _8: bool;
-    let mut _9: usize;
-    let _10: bool;
+    let mut _4: bool;
+    let mut _6: bool;
+    let _7: bool;
+    let mut _8: usize;
+    let _9: bool;
     scope 1 {
         debug v => _1;
         let _2: &'?3 usize;
         scope 2 {
             debug p => _2;
-            let _6: &'?4 usize;
+            let _5: &'?4 usize;
             scope 3 {
-                debug q => _6;
+                debug q => _5;
             }
         }
     }
@@ -52,50 +51,50 @@ fn main() -> () {
         StorageLive(_2);
         StorageLive(_3);
         _3 = const ConstValue(Scalar(0x0000000000000000): usize);
-        _4 = Len(_1);
-        _5 = Lt(copy _3, copy _4);
-        assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, copy _3) -> [success: bb1, unwind: bb7];
+        FakeRead(ForIndex, _1);
+        _4 = Lt(copy _3, const ValTree(Leaf(0x0000000000000003): usize));
+        assert(move _4, "index out of bounds: the length is {} but the index is {}", const ValTree(Leaf(0x0000000000000003): usize), copy _3) -> [success: bb1, unwind: bb7];
     }
 
     bb1: {
         _2 = &'?2 _1[_3];
         FakeRead(ForLet(None), _2);
+        StorageLive(_5);
+        _5 = copy _2;
+        FakeRead(ForLet(None), _5);
         StorageLive(_6);
-        _6 = copy _2;
-        FakeRead(ForLet(None), _6);
-        StorageLive(_7);
-        _7 = const ConstValue(Scalar(0x01): bool);
-        switchInt(move _7) -> [0: bb4, otherwise: bb2];
+        _6 = const ConstValue(Scalar(0x01): bool);
+        switchInt(move _6) -> [0: bb4, otherwise: bb2];
     }
 
     bb2: {
+        StorageLive(_7);
         StorageLive(_8);
-        StorageLive(_9);
-        _9 = copy (*_6);
-        _8 = ConstValue(ZeroSized: fn(usize) -> bool {use_x})(move _9) -> [return: bb3, unwind: bb7];
+        _8 = copy (*_5);
+        _7 = ConstValue(ZeroSized: fn(usize) -> bool {use_x})(move _8) -> [return: bb3, unwind: bb7];
     }
 
     bb3: {
-        StorageDead(_9);
         StorageDead(_8);
+        StorageDead(_7);
         _0 = const ConstValue(ZeroSized: ());
         goto -> bb6;
     }
 
     bb4: {
-        StorageLive(_10);
-        _10 = ConstValue(ZeroSized: fn(usize) -> bool {use_x})(const ConstValue(Scalar(0x0000000000000016): usize)) -> [return: bb5, unwind: bb7];
+        StorageLive(_9);
+        _9 = ConstValue(ZeroSized: fn(usize) -> bool {use_x})(const ConstValue(Scalar(0x0000000000000016): usize)) -> [return: bb5, unwind: bb7];
     }
 
     bb5: {
-        StorageDead(_10);
+        StorageDead(_9);
         _0 = const ConstValue(ZeroSized: ());
         goto -> bb6;
     }
 
     bb6: {
-        StorageDead(_7);
         StorageDead(_6);
+        StorageDead(_5);
         StorageDead(_3);
         StorageDead(_2);
         StorageDead(_1);

tests/mir-opt/pre-codegen/optimizes_into_variable.main.GVN.32bit.panic-abort.diff

@@ -7,17 +7,16 @@
       let mut _2: (i32, bool);
       let mut _4: [i32; 6];
       let _5: usize;
-      let mut _6: usize;
-      let mut _7: bool;
-      let mut _9: u32;
+      let mut _6: bool;
+      let mut _8: u32;
       scope 1 {
           debug x => _1;
           let _3: i32;
           scope 2 {
               debug y => _3;
-              let _8: u32;
+              let _7: u32;
               scope 3 {
-                  debug z => _8;
+                  debug z => _7;
               }
           }
       }
@@ -38,10 +37,9 @@
           _4 = [const 0_i32, const 1_i32, const 2_i32, const 3_i32, const 4_i32, const 5_i32];
           StorageLive(_5);
           _5 = const 3_usize;
-          _6 = const 6_usize;
--         _7 = Lt(copy _5, copy _6);
--         assert(move _7, "index out of bounds: the length is {} but the index is {}", move _6, copy _5) -> [success: bb2, unwind unreachable];
-+         _7 = const true;
+-         _6 = Lt(copy _5, const 6_usize);
+-         assert(move _6, "index out of bounds: the length is {} but the index is {}", const 6_usize, copy _5) -> [success: bb2, unwind unreachable];
++         _6 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 6_usize, const 3_usize) -> [success: bb2, unwind unreachable];
       }
   
@@ -50,13 +48,13 @@
 +         _3 = const 3_i32;
           StorageDead(_5);
           StorageDead(_4);
+          StorageLive(_7);
           StorageLive(_8);
-          StorageLive(_9);
-          _9 = const 42_u32;
--         _8 = copy _9;
-+         _8 = const 42_u32;
-          StorageDead(_9);
+          _8 = const 42_u32;
+-         _7 = copy _8;
++         _7 = const 42_u32;
           StorageDead(_8);
+          StorageDead(_7);
           StorageDead(_3);
           StorageDead(_1);
           return;

tests/mir-opt/pre-codegen/optimizes_into_variable.main.GVN.32bit.panic-unwind.diff

@@ -7,17 +7,16 @@
       let mut _2: (i32, bool);
       let mut _4: [i32; 6];
       let _5: usize;
-      let mut _6: usize;
-      let mut _7: bool;
-      let mut _9: u32;
+      let mut _6: bool;
+      let mut _8: u32;
       scope 1 {
           debug x => _1;
           let _3: i32;
           scope 2 {
               debug y => _3;
-              let _8: u32;
+              let _7: u32;
               scope 3 {
-                  debug z => _8;
+                  debug z => _7;
               }
           }
       }
@@ -38,10 +37,9 @@
           _4 = [const 0_i32, const 1_i32, const 2_i32, const 3_i32, const 4_i32, const 5_i32];
           StorageLive(_5);
           _5 = const 3_usize;
-          _6 = const 6_usize;
--         _7 = Lt(copy _5, copy _6);
--         assert(move _7, "index out of bounds: the length is {} but the index is {}", move _6, copy _5) -> [success: bb2, unwind continue];
-+         _7 = const true;
+-         _6 = Lt(copy _5, const 6_usize);
+-         assert(move _6, "index out of bounds: the length is {} but the index is {}", const 6_usize, copy _5) -> [success: bb2, unwind continue];
++         _6 = const true;
 +         assert(const true, "index out of bounds: the length is {} but the index is {}", const 6_usize, const 3_usize) -> [success: bb2, unwind continue];
       }
   
@@ -50,13 +48,13 @@
 +         _3 = const 3_i32;
           StorageDead(_5);
           StorageDead(_4);
+          StorageLive(_7);
           StorageLive(_8);
-          StorageLive(_9);
-          _9 = const 42_u32;
--         _8 = copy _9;
-+         _8 = const 42_u32;
-          StorageDead(_9);
+          _8 = const 42_u32;
+-         _7 = copy _8;
++         _7 = const 42_u32;
           StorageDead(_8);
+          StorageDead(_7);
           StorageDead(_3);
           StorageDead(_1);
           return;