Rollup merge of #142185 - saethlin:refprop-moves, r=cjgillot

Convert moves of references to copies in ReferencePropagation

This is a fix for https://github.com/rust-lang/rust/issues/141101.

The root cause of this miscompile is that the SsaLocals analysis that MIR transforms use is supposed to detect locals that are only written to once, in their single assignment. But that analysis is subtly wrong; it does not consider `Operand::Move` to be a write even though the meaning ascribed to `Operand::Move` (at least as a function parameter) by Miri is that the callee may have done arbitrary writes to the caller's Local that the Operand wraps (because `Move` is pass-by-pointer). So Miri conwiders `Operand::Move` to be a write but both the MIR visitor system considers it a read, and so does SsaLocals.

I have tried fixing this by changing the `PlaceContext` that is ascribed to an `Operand::Move` to a `MutatingUseContext` but that seems to have borrow checker implications, and changing SsaLocals seems to have wide-ranging regressions in MIR optimizations.

So instead of doing those, this PR adds a new kludge to ReferencePropagation, which follows the same line of thinking as the kludge in CopyProp that solves this same problem inside that pass: https://github.com/rust-lang/rust/blob/a5584a8fe16037dc01782064fa41424a6dbe9987/compiler/rustc_mir_transform/src/copy_prop.rs#L65-L98

28 files changed, 194 insertions, 88 deletions

diff --git a/compiler/rustc_mir_transform/src/ref_prop.rs b/compiler/rustc_mir_transform/src/ref_prop.rs
index d1c2d6b508f..6f61215cee2 100644
--- a/compiler/rustc_mir_transform/src/ref_prop.rs
+++ b/compiler/rustc_mir_transform/src/ref_prop.rs
@@ -79,6 +79,7 @@ impl<'tcx> crate::MirPass<'tcx> for ReferencePropagation {
     #[instrument(level = "trace", skip(self, tcx, body))]
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         debug!(def_id = ?body.source.def_id());
+        move_to_copy_pointers(tcx, body);
         while propagate_ssa(tcx, body) {}
     }
 
@@ -87,11 +88,43 @@ impl<'tcx> crate::MirPass<'tcx> for ReferencePropagation {
     }
 }
 
+/// The SSA analysis done by [`SsaLocals`] treats [`Operand::Move`] as a read, even though in
+/// general [`Operand::Move`] represents pass-by-pointer where the callee can overwrite the
+/// pointee (Miri always considers the place deinitialized). CopyProp has a similar trick to
+/// turn [`Operand::Move`] into [`Operand::Copy`] when required for an optimization, but in this
+/// pass we just turn all moves of pointers into copies because pointers should be by-value anyway.
+fn move_to_copy_pointers<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
+    let mut visitor = MoveToCopyVisitor { tcx, local_decls: &body.local_decls };
+    for (bb, data) in body.basic_blocks.as_mut_preserves_cfg().iter_enumerated_mut() {
+        visitor.visit_basic_block_data(bb, data);
+    }
+
+    struct MoveToCopyVisitor<'a, 'tcx> {
+        tcx: TyCtxt<'tcx>,
+        local_decls: &'a IndexVec<Local, LocalDecl<'tcx>>,
+    }
+
+    impl<'a, 'tcx> MutVisitor<'tcx> for MoveToCopyVisitor<'a, 'tcx> {
+        fn tcx(&self) -> TyCtxt<'tcx> {
+            self.tcx
+        }
+
+        fn visit_operand(&mut self, operand: &mut Operand<'tcx>, loc: Location) {
+            if let Operand::Move(place) = *operand {
+                if place.ty(self.local_decls, self.tcx).ty.is_any_ptr() {
+                    *operand = Operand::Copy(place);
+                }
+            }
+            self.super_operand(operand, loc);
+        }
+    }
+}
+
 fn propagate_ssa<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) -> bool {
     let typing_env = body.typing_env(tcx);
     let ssa = SsaLocals::new(tcx, body, typing_env);
 
-    let mut replacer = compute_replacement(tcx, body, &ssa);
+    let mut replacer = compute_replacement(tcx, body, ssa);
     debug!(?replacer.targets);
     debug!(?replacer.allowed_replacements);
     debug!(?replacer.storage_to_remove);
@@ -119,7 +152,7 @@ enum Value<'tcx> {
 fn compute_replacement<'tcx>(
     tcx: TyCtxt<'tcx>,
     body: &Body<'tcx>,
-    ssa: &SsaLocals,
+    ssa: SsaLocals,
 ) -> Replacer<'tcx> {
     let always_live_locals = always_storage_live_locals(body);
 
@@ -138,7 +171,7 @@ fn compute_replacement<'tcx>(
     // reborrowed references.
     let mut storage_to_remove = DenseBitSet::new_empty(body.local_decls.len());
 
-    let fully_replaceable_locals = fully_replaceable_locals(ssa);
+    let fully_replaceable_locals = fully_replaceable_locals(&ssa);
 
     // Returns true iff we can use `place` as a pointee.
     //
diff --git a/tests/mir-opt/building/index_array_and_slice.rs b/tests/mir-opt/building/index_array_and_slice.rs
index f91b37567f7..42ede66d92b 100644
--- a/tests/mir-opt/building/index_array_and_slice.rs
+++ b/tests/mir-opt/building/index_array_and_slice.rs
@@ -55,7 +55,7 @@ struct WithSliceTail(f64, [i32]);
 fn index_custom(custom: &WithSliceTail, index: usize) -> &i32 {
     // CHECK: bb0:
     // CHECK: [[PTR:_.+]] = &raw const (fake) ((*_1).1: [i32]);
-    // CHECK: [[LEN:_.+]] = PtrMetadata(move [[PTR]]);
+    // CHECK: [[LEN:_.+]] = PtrMetadata(copy [[PTR]]);
     // CHECK: [[LT:_.+]] = Lt(copy _2, copy [[LEN]]);
     // CHECK: assert(move [[LT]], "index out of bounds{{.+}}", move [[LEN]], copy _2) -> [success: bb1,
 
diff --git a/tests/mir-opt/dont_reset_cast_kind_without_updating_operand.test.GVN.32bit.panic-abort.diff b/tests/mir-opt/dont_reset_cast_kind_without_updating_operand.test.GVN.32bit.panic-abort.diff
index 25ffff619e6..f203b80e477 100644
--- a/tests/mir-opt/dont_reset_cast_kind_without_updating_operand.test.GVN.32bit.panic-abort.diff
+++ b/tests/mir-opt/dont_reset_cast_kind_without_updating_operand.test.GVN.32bit.panic-abort.diff
@@ -112,7 +112,7 @@
           StorageDead(_17);
           StorageDead(_16);
           StorageDead(_14);
-          _3 = ShallowInitBox(move _13, ());
+          _3 = ShallowInitBox(copy _13, ());
           StorageDead(_13);
           StorageDead(_12);
           StorageDead(_11);
diff --git a/tests/mir-opt/dont_reset_cast_kind_without_updating_operand.test.GVN.64bit.panic-abort.diff b/tests/mir-opt/dont_reset_cast_kind_without_updating_operand.test.GVN.64bit.panic-abort.diff
index 839b53e3b0b..f072eb6ef8b 100644
--- a/tests/mir-opt/dont_reset_cast_kind_without_updating_operand.test.GVN.64bit.panic-abort.diff
+++ b/tests/mir-opt/dont_reset_cast_kind_without_updating_operand.test.GVN.64bit.panic-abort.diff
@@ -112,7 +112,7 @@
           StorageDead(_17);
           StorageDead(_16);
           StorageDead(_14);
-          _3 = ShallowInitBox(move _13, ());
+          _3 = ShallowInitBox(copy _13, ());
           StorageDead(_13);
           StorageDead(_12);
           StorageDead(_11);
diff --git a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-abort.diff b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-abort.diff
index c2d144c98c3..3f854b6cbcf 100644
--- a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-abort.diff
+++ b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-abort.diff
@@ -103,7 +103,7 @@
           StorageDead(_6);
           _4 = copy _5 as *mut [u8] (Transmute);
           StorageDead(_5);
-          _3 = move _4 as *mut u8 (PtrToPtr);
+          _3 = copy _4 as *mut u8 (PtrToPtr);
           StorageDead(_4);
           StorageDead(_3);
 -         StorageDead(_1);
diff --git a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-unwind.diff b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-unwind.diff
index 88bd4628c29..15a9d9e39c4 100644
--- a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-unwind.diff
+++ b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-unwind.diff
@@ -46,7 +46,7 @@
           StorageDead(_6);
           _4 = copy _5 as *mut [u8] (Transmute);
           StorageDead(_5);
-          _3 = move _4 as *mut u8 (PtrToPtr);
+          _3 = copy _4 as *mut u8 (PtrToPtr);
           StorageDead(_4);
           StorageDead(_3);
 -         StorageDead(_1);
diff --git a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-abort.diff b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-abort.diff
index 8641d2d6fa8..1dbe9394e70 100644
--- a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-abort.diff
+++ b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-abort.diff
@@ -103,7 +103,7 @@
           StorageDead(_6);
           _4 = copy _5 as *mut [u8] (Transmute);
           StorageDead(_5);
-          _3 = move _4 as *mut u8 (PtrToPtr);
+          _3 = copy _4 as *mut u8 (PtrToPtr);
           StorageDead(_4);
           StorageDead(_3);
 -         StorageDead(_1);
diff --git a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-unwind.diff b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-unwind.diff
index 0c52f1e0583..df008ececae 100644
--- a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-unwind.diff
+++ b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-unwind.diff
@@ -46,7 +46,7 @@
           StorageDead(_6);
           _4 = copy _5 as *mut [u8] (Transmute);
           StorageDead(_5);
-          _3 = move _4 as *mut u8 (PtrToPtr);
+          _3 = copy _4 as *mut u8 (PtrToPtr);
           StorageDead(_4);
           StorageDead(_3);
 -         StorageDead(_1);
diff --git a/tests/mir-opt/pre-codegen/slice_index.slice_get_mut_usize.PreCodegen.after.panic-abort.mir b/tests/mir-opt/pre-codegen/slice_index.slice_get_mut_usize.PreCodegen.after.panic-abort.mir
index d1b1e3d7dd7..ebe8b23354b 100644
--- a/tests/mir-opt/pre-codegen/slice_index.slice_get_mut_usize.PreCodegen.after.panic-abort.mir
+++ b/tests/mir-opt/pre-codegen/slice_index.slice_get_mut_usize.PreCodegen.after.panic-abort.mir
@@ -30,7 +30,7 @@ fn slice_get_mut_usize(_1: &mut [u32], _2: usize) -> Option<&mut u32> {
         StorageDead(_3);
         StorageLive(_5);
         _5 = &mut (*_1)[_2];
-        _0 = Option::<&mut u32>::Some(move _5);
+        _0 = Option::<&mut u32>::Some(copy _5);
         StorageDead(_5);
         goto -> bb3;
     }
diff --git a/tests/mir-opt/pre-codegen/slice_index.slice_get_mut_usize.PreCodegen.after.panic-unwind.mir b/tests/mir-opt/pre-codegen/slice_index.slice_get_mut_usize.PreCodegen.after.panic-unwind.mir
index d1b1e3d7dd7..ebe8b23354b 100644
--- a/tests/mir-opt/pre-codegen/slice_index.slice_get_mut_usize.PreCodegen.after.panic-unwind.mir
+++ b/tests/mir-opt/pre-codegen/slice_index.slice_get_mut_usize.PreCodegen.after.panic-unwind.mir
@@ -30,7 +30,7 @@ fn slice_get_mut_usize(_1: &mut [u32], _2: usize) -> Option<&mut u32> {
         StorageDead(_3);
         StorageLive(_5);
         _5 = &mut (*_1)[_2];
-        _0 = Option::<&mut u32>::Some(move _5);
+        _0 = Option::<&mut u32>::Some(copy _5);
         StorageDead(_5);
         goto -> bb3;
     }
diff --git a/tests/mir-opt/pre-codegen/slice_iter.enumerated_loop.PreCodegen.after.panic-abort.mir b/tests/mir-opt/pre-codegen/slice_iter.enumerated_loop.PreCodegen.after.panic-abort.mir
index d389e4069d0..72b39a7f6a8 100644
--- a/tests/mir-opt/pre-codegen/slice_iter.enumerated_loop.PreCodegen.after.panic-abort.mir
+++ b/tests/mir-opt/pre-codegen/slice_iter.enumerated_loop.PreCodegen.after.panic-abort.mir
@@ -143,7 +143,7 @@ fn enumerated_loop(_1: &[T], _2: impl Fn(usize, &T)) -> () {
         _4 = &raw const (*_1);
         StorageLive(_5);
         _5 = copy _4 as *const T (PtrToPtr);
-        _6 = NonNull::<T> { pointer: move _5 };
+        _6 = NonNull::<T> { pointer: copy _5 };
         StorageDead(_5);
         StorageLive(_9);
         switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb1, otherwise: bb2];
@@ -155,7 +155,7 @@ fn enumerated_loop(_1: &[T], _2: impl Fn(usize, &T)) -> () {
         _7 = copy _4 as *mut T (PtrToPtr);
         _8 = Offset(copy _7, copy _3);
         StorageDead(_7);
-        _9 = move _8 as *const T (PtrToPtr);
+        _9 = copy _8 as *const T (PtrToPtr);
         StorageDead(_8);
         goto -> bb3;
     }
@@ -202,7 +202,7 @@ fn enumerated_loop(_1: &[T], _2: impl Fn(usize, &T)) -> () {
         _17 = copy _14 as *mut T (Transmute);
         StorageLive(_18);
         _18 = copy _16 as *mut T (Transmute);
-        _19 = Eq(move _17, move _18);
+        _19 = Eq(copy _17, copy _18);
         StorageDead(_18);
         StorageDead(_17);
         switchInt(move _19) -> [0: bb6, otherwise: bb7];
@@ -214,9 +214,9 @@ fn enumerated_loop(_1: &[T], _2: impl Fn(usize, &T)) -> () {
         StorageLive(_21);
         StorageLive(_20);
         _20 = copy _14 as *const T (Transmute);
-        _21 = Offset(move _20, const 1_usize);
+        _21 = Offset(copy _20, const 1_usize);
         StorageDead(_20);
-        _22 = NonNull::<T> { pointer: move _21 };
+        _22 = NonNull::<T> { pointer: copy _21 };
         StorageDead(_21);
         _11 = move _22;
         StorageDead(_22);
@@ -282,7 +282,7 @@ fn enumerated_loop(_1: &[T], _2: impl Fn(usize, &T)) -> () {
         StorageDead(_23);
         StorageDead(_15);
         StorageDead(_14);
-        _28 = move ((_27 as Some).0: &T);
+        _28 = copy ((_27 as Some).0: &T);
         StorageDead(_27);
         _29 = copy _13;
         _30 = AddWithOverflow(copy _13, const 1_usize);
diff --git a/tests/mir-opt/pre-codegen/slice_iter.enumerated_loop.PreCodegen.after.panic-unwind.mir b/tests/mir-opt/pre-codegen/slice_iter.enumerated_loop.PreCodegen.after.panic-unwind.mir
index 8c5fbda6392..42aa152ec99 100644
--- a/tests/mir-opt/pre-codegen/slice_iter.enumerated_loop.PreCodegen.after.panic-unwind.mir
+++ b/tests/mir-opt/pre-codegen/slice_iter.enumerated_loop.PreCodegen.after.panic-unwind.mir
@@ -70,7 +70,7 @@ fn enumerated_loop(_1: &[T], _2: impl Fn(usize, &T)) -> () {
         _4 = &raw const (*_1);
         StorageLive(_5);
         _5 = copy _4 as *const T (PtrToPtr);
-        _6 = NonNull::<T> { pointer: move _5 };
+        _6 = NonNull::<T> { pointer: copy _5 };
         StorageDead(_5);
         StorageLive(_9);
         switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb1, otherwise: bb2];
@@ -82,7 +82,7 @@ fn enumerated_loop(_1: &[T], _2: impl Fn(usize, &T)) -> () {
         _7 = copy _4 as *mut T (PtrToPtr);
         _8 = Offset(copy _7, copy _3);
         StorageDead(_7);
-        _9 = move _8 as *const T (PtrToPtr);
+        _9 = copy _8 as *const T (PtrToPtr);
         StorageDead(_8);
         goto -> bb3;
     }
@@ -95,7 +95,7 @@ fn enumerated_loop(_1: &[T], _2: impl Fn(usize, &T)) -> () {
     bb3: {
         StorageLive(_10);
         _10 = copy _9;
-        _11 = std::slice::Iter::<'_, T> { ptr: copy _6, end_or_len: move _10, _marker: const ZeroSized: PhantomData<&T> };
+        _11 = std::slice::Iter::<'_, T> { ptr: copy _6, end_or_len: copy _10, _marker: const ZeroSized: PhantomData<&T> };
         StorageDead(_10);
         StorageDead(_9);
         StorageDead(_4);
diff --git a/tests/mir-opt/pre-codegen/slice_iter.forward_loop.PreCodegen.after.panic-abort.mir b/tests/mir-opt/pre-codegen/slice_iter.forward_loop.PreCodegen.after.panic-abort.mir
index 216e05ec5b7..0d65640ec9b 100644
--- a/tests/mir-opt/pre-codegen/slice_iter.forward_loop.PreCodegen.after.panic-abort.mir
+++ b/tests/mir-opt/pre-codegen/slice_iter.forward_loop.PreCodegen.after.panic-abort.mir
@@ -110,7 +110,7 @@ fn forward_loop(_1: &[T], _2: impl Fn(&T)) -> () {
         _4 = &raw const (*_1);
         StorageLive(_5);
         _5 = copy _4 as *const T (PtrToPtr);
-        _6 = NonNull::<T> { pointer: move _5 };
+        _6 = NonNull::<T> { pointer: copy _5 };
         StorageDead(_5);
         StorageLive(_9);
         switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb1, otherwise: bb2];
@@ -122,7 +122,7 @@ fn forward_loop(_1: &[T], _2: impl Fn(&T)) -> () {
         _7 = copy _4 as *mut T (PtrToPtr);
         _8 = Offset(copy _7, copy _3);
         StorageDead(_7);
-        _9 = move _8 as *const T (PtrToPtr);
+        _9 = copy _8 as *const T (PtrToPtr);
         StorageDead(_8);
         goto -> bb3;
     }
@@ -164,7 +164,7 @@ fn forward_loop(_1: &[T], _2: impl Fn(&T)) -> () {
         _16 = copy _13 as *mut T (Transmute);
         StorageLive(_17);
         _17 = copy _15 as *mut T (Transmute);
-        _18 = Eq(move _16, move _17);
+        _18 = Eq(copy _16, copy _17);
         StorageDead(_17);
         StorageDead(_16);
         switchInt(move _18) -> [0: bb6, otherwise: bb7];
@@ -176,9 +176,9 @@ fn forward_loop(_1: &[T], _2: impl Fn(&T)) -> () {
         StorageLive(_20);
         StorageLive(_19);
         _19 = copy _13 as *const T (Transmute);
-        _20 = Offset(move _19, const 1_usize);
+        _20 = Offset(copy _19, const 1_usize);
         StorageDead(_19);
-        _21 = NonNull::<T> { pointer: move _20 };
+        _21 = NonNull::<T> { pointer: copy _20 };
         StorageDead(_20);
         _11 = move _21;
         StorageDead(_21);
diff --git a/tests/mir-opt/pre-codegen/slice_iter.forward_loop.PreCodegen.after.panic-unwind.mir b/tests/mir-opt/pre-codegen/slice_iter.forward_loop.PreCodegen.after.panic-unwind.mir
index 00102391980..02efb193474 100644
--- a/tests/mir-opt/pre-codegen/slice_iter.forward_loop.PreCodegen.after.panic-unwind.mir
+++ b/tests/mir-opt/pre-codegen/slice_iter.forward_loop.PreCodegen.after.panic-unwind.mir
@@ -110,7 +110,7 @@ fn forward_loop(_1: &[T], _2: impl Fn(&T)) -> () {
         _4 = &raw const (*_1);
         StorageLive(_5);
         _5 = copy _4 as *const T (PtrToPtr);
-        _6 = NonNull::<T> { pointer: move _5 };
+        _6 = NonNull::<T> { pointer: copy _5 };
         StorageDead(_5);
         StorageLive(_9);
         switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb1, otherwise: bb2];
@@ -122,7 +122,7 @@ fn forward_loop(_1: &[T], _2: impl Fn(&T)) -> () {
         _7 = copy _4 as *mut T (PtrToPtr);
         _8 = Offset(copy _7, copy _3);
         StorageDead(_7);
-        _9 = move _8 as *const T (PtrToPtr);
+        _9 = copy _8 as *const T (PtrToPtr);
         StorageDead(_8);
         goto -> bb3;
     }
@@ -164,7 +164,7 @@ fn forward_loop(_1: &[T], _2: impl Fn(&T)) -> () {
         _16 = copy _13 as *mut T (Transmute);
         StorageLive(_17);
         _17 = copy _15 as *mut T (Transmute);
-        _18 = Eq(move _16, move _17);
+        _18 = Eq(copy _16, copy _17);
         StorageDead(_17);
         StorageDead(_16);
         switchInt(move _18) -> [0: bb6, otherwise: bb7];
@@ -176,9 +176,9 @@ fn forward_loop(_1: &[T], _2: impl Fn(&T)) -> () {
         StorageLive(_20);
         StorageLive(_19);
         _19 = copy _13 as *const T (Transmute);
-        _20 = Offset(move _19, const 1_usize);
+        _20 = Offset(copy _19, const 1_usize);
         StorageDead(_19);
-        _21 = NonNull::<T> { pointer: move _20 };
+        _21 = NonNull::<T> { pointer: copy _20 };
         StorageDead(_20);
         _11 = move _21;
         StorageDead(_21);
diff --git a/tests/mir-opt/pre-codegen/slice_iter.reverse_loop.PreCodegen.after.panic-abort.mir b/tests/mir-opt/pre-codegen/slice_iter.reverse_loop.PreCodegen.after.panic-abort.mir
index b09e3622344..ee638be7d7a 100644
--- a/tests/mir-opt/pre-codegen/slice_iter.reverse_loop.PreCodegen.after.panic-abort.mir
+++ b/tests/mir-opt/pre-codegen/slice_iter.reverse_loop.PreCodegen.after.panic-abort.mir
@@ -70,7 +70,7 @@ fn reverse_loop(_1: &[T], _2: impl Fn(&T)) -> () {
         _4 = &raw const (*_1);
         StorageLive(_5);
         _5 = copy _4 as *const T (PtrToPtr);
-        _6 = NonNull::<T> { pointer: move _5 };
+        _6 = NonNull::<T> { pointer: copy _5 };
         StorageDead(_5);
         StorageLive(_9);
         switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb1, otherwise: bb2];
@@ -82,7 +82,7 @@ fn reverse_loop(_1: &[T], _2: impl Fn(&T)) -> () {
         _7 = copy _4 as *mut T (PtrToPtr);
         _8 = Offset(copy _7, copy _3);
         StorageDead(_7);
-        _9 = move _8 as *const T (PtrToPtr);
+        _9 = copy _8 as *const T (PtrToPtr);
         StorageDead(_8);
         goto -> bb3;
     }
@@ -95,7 +95,7 @@ fn reverse_loop(_1: &[T], _2: impl Fn(&T)) -> () {
     bb3: {
         StorageLive(_10);
         _10 = copy _9;
-        _11 = std::slice::Iter::<'_, T> { ptr: copy _6, end_or_len: move _10, _marker: const ZeroSized: PhantomData<&T> };
+        _11 = std::slice::Iter::<'_, T> { ptr: copy _6, end_or_len: copy _10, _marker: const ZeroSized: PhantomData<&T> };
         StorageDead(_10);
         StorageDead(_9);
         StorageDead(_4);
diff --git a/tests/mir-opt/pre-codegen/slice_iter.reverse_loop.PreCodegen.after.panic-unwind.mir b/tests/mir-opt/pre-codegen/slice_iter.reverse_loop.PreCodegen.after.panic-unwind.mir
index 12b54b57b84..aee29d4d4fe 100644
--- a/tests/mir-opt/pre-codegen/slice_iter.reverse_loop.PreCodegen.after.panic-unwind.mir
+++ b/tests/mir-opt/pre-codegen/slice_iter.reverse_loop.PreCodegen.after.panic-unwind.mir
@@ -70,7 +70,7 @@ fn reverse_loop(_1: &[T], _2: impl Fn(&T)) -> () {
         _4 = &raw const (*_1);
         StorageLive(_5);
         _5 = copy _4 as *const T (PtrToPtr);
-        _6 = NonNull::<T> { pointer: move _5 };
+        _6 = NonNull::<T> { pointer: copy _5 };
         StorageDead(_5);
         StorageLive(_9);
         switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb1, otherwise: bb2];
@@ -82,7 +82,7 @@ fn reverse_loop(_1: &[T], _2: impl Fn(&T)) -> () {
         _7 = copy _4 as *mut T (PtrToPtr);
         _8 = Offset(copy _7, copy _3);
         StorageDead(_7);
-        _9 = move _8 as *const T (PtrToPtr);
+        _9 = copy _8 as *const T (PtrToPtr);
         StorageDead(_8);
         goto -> bb3;
     }
@@ -95,7 +95,7 @@ fn reverse_loop(_1: &[T], _2: impl Fn(&T)) -> () {
     bb3: {
         StorageLive(_10);
         _10 = copy _9;
-        _11 = std::slice::Iter::<'_, T> { ptr: copy _6, end_or_len: move _10, _marker: const ZeroSized: PhantomData<&T> };
+        _11 = std::slice::Iter::<'_, T> { ptr: copy _6, end_or_len: copy _10, _marker: const ZeroSized: PhantomData<&T> };
         StorageDead(_10);
         StorageDead(_9);
         StorageDead(_4);
diff --git a/tests/mir-opt/pre-codegen/slice_iter.slice_iter_generic_is_empty.PreCodegen.after.panic-abort.mir b/tests/mir-opt/pre-codegen/slice_iter.slice_iter_generic_is_empty.PreCodegen.after.panic-abort.mir
index 38d00cfbabd..9b510380b10 100644
--- a/tests/mir-opt/pre-codegen/slice_iter.slice_iter_generic_is_empty.PreCodegen.after.panic-abort.mir
+++ b/tests/mir-opt/pre-codegen/slice_iter.slice_iter_generic_is_empty.PreCodegen.after.panic-abort.mir
@@ -39,7 +39,7 @@ fn slice_iter_generic_is_empty(_1: &std::slice::Iter<'_, T>) -> bool {
     bb1: {
         StorageLive(_2);
         _2 = copy ((*_1).1: *const T);
-        _3 = move _2 as std::ptr::NonNull<T> (Transmute);
+        _3 = copy _2 as std::ptr::NonNull<T> (Transmute);
         StorageDead(_2);
         StorageLive(_5);
         StorageLive(_4);
@@ -48,7 +48,7 @@ fn slice_iter_generic_is_empty(_1: &std::slice::Iter<'_, T>) -> bool {
         StorageDead(_4);
         StorageLive(_6);
         _6 = copy _3 as *mut T (Transmute);
-        _0 = Eq(move _5, move _6);
+        _0 = Eq(copy _5, copy _6);
         StorageDead(_6);
         StorageDead(_5);
         goto -> bb3;
diff --git a/tests/mir-opt/pre-codegen/slice_iter.slice_iter_generic_is_empty.PreCodegen.after.panic-unwind.mir b/tests/mir-opt/pre-codegen/slice_iter.slice_iter_generic_is_empty.PreCodegen.after.panic-unwind.mir
index 38d00cfbabd..9b510380b10 100644
--- a/tests/mir-opt/pre-codegen/slice_iter.slice_iter_generic_is_empty.PreCodegen.after.panic-unwind.mir
+++ b/tests/mir-opt/pre-codegen/slice_iter.slice_iter_generic_is_empty.PreCodegen.after.panic-unwind.mir
@@ -39,7 +39,7 @@ fn slice_iter_generic_is_empty(_1: &std::slice::Iter<'_, T>) -> bool {
     bb1: {
         StorageLive(_2);
         _2 = copy ((*_1).1: *const T);
-        _3 = move _2 as std::ptr::NonNull<T> (Transmute);
+        _3 = copy _2 as std::ptr::NonNull<T> (Transmute);
         StorageDead(_2);
         StorageLive(_5);
         StorageLive(_4);
@@ -48,7 +48,7 @@ fn slice_iter_generic_is_empty(_1: &std::slice::Iter<'_, T>) -> bool {
         StorageDead(_4);
         StorageLive(_6);
         _6 = copy _3 as *mut T (Transmute);
-        _0 = Eq(move _5, move _6);
+        _0 = Eq(copy _5, copy _6);
         StorageDead(_6);
         StorageDead(_5);
         goto -> bb3;
diff --git a/tests/mir-opt/pre-codegen/slice_iter.slice_iter_next.PreCodegen.after.panic-abort.mir b/tests/mir-opt/pre-codegen/slice_iter.slice_iter_next.PreCodegen.after.panic-abort.mir
index c0ed0aea1e2..cc0fce26149 100644
--- a/tests/mir-opt/pre-codegen/slice_iter.slice_iter_next.PreCodegen.after.panic-abort.mir
+++ b/tests/mir-opt/pre-codegen/slice_iter.slice_iter_next.PreCodegen.after.panic-abort.mir
@@ -72,7 +72,7 @@ fn slice_iter_next(_1: &mut std::slice::Iter<'_, T>) -> Option<&T> {
         _5 = copy _2 as *mut T (Transmute);
         StorageLive(_6);
         _6 = copy _4 as *mut T (Transmute);
-        _7 = Eq(move _5, move _6);
+        _7 = Eq(copy _5, copy _6);
         StorageDead(_6);
         StorageDead(_5);
         switchInt(move _7) -> [0: bb2, otherwise: bb3];
@@ -84,9 +84,9 @@ fn slice_iter_next(_1: &mut std::slice::Iter<'_, T>) -> Option<&T> {
         StorageLive(_9);
         StorageLive(_8);
         _8 = copy _2 as *const T (Transmute);
-        _9 = Offset(move _8, const 1_usize);
+        _9 = Offset(copy _8, const 1_usize);
         StorageDead(_8);
-        _10 = NonNull::<T> { pointer: move _9 };
+        _10 = NonNull::<T> { pointer: copy _9 };
         StorageDead(_9);
         ((*_1).0: std::ptr::NonNull<T>) = move _10;
         StorageDead(_10);
diff --git a/tests/mir-opt/pre-codegen/slice_iter.slice_iter_next.PreCodegen.after.panic-unwind.mir b/tests/mir-opt/pre-codegen/slice_iter.slice_iter_next.PreCodegen.after.panic-unwind.mir
index c0ed0aea1e2..cc0fce26149 100644
--- a/tests/mir-opt/pre-codegen/slice_iter.slice_iter_next.PreCodegen.after.panic-unwind.mir
+++ b/tests/mir-opt/pre-codegen/slice_iter.slice_iter_next.PreCodegen.after.panic-unwind.mir
@@ -72,7 +72,7 @@ fn slice_iter_next(_1: &mut std::slice::Iter<'_, T>) -> Option<&T> {
         _5 = copy _2 as *mut T (Transmute);
         StorageLive(_6);
         _6 = copy _4 as *mut T (Transmute);
-        _7 = Eq(move _5, move _6);
+        _7 = Eq(copy _5, copy _6);
         StorageDead(_6);
         StorageDead(_5);
         switchInt(move _7) -> [0: bb2, otherwise: bb3];
@@ -84,9 +84,9 @@ fn slice_iter_next(_1: &mut std::slice::Iter<'_, T>) -> Option<&T> {
         StorageLive(_9);
         StorageLive(_8);
         _8 = copy _2 as *const T (Transmute);
-        _9 = Offset(move _8, const 1_usize);
+        _9 = Offset(copy _8, const 1_usize);
         StorageDead(_8);
-        _10 = NonNull::<T> { pointer: move _9 };
+        _10 = NonNull::<T> { pointer: copy _9 };
         StorageDead(_9);
         ((*_1).0: std::ptr::NonNull<T>) = move _10;
         StorageDead(_10);
diff --git a/tests/mir-opt/reference_prop.debuginfo.ReferencePropagation.diff b/tests/mir-opt/reference_prop.debuginfo.ReferencePropagation.diff
index 05ad9dbf3cc..3da795b61f9 100644
--- a/tests/mir-opt/reference_prop.debuginfo.ReferencePropagation.diff
+++ b/tests/mir-opt/reference_prop.debuginfo.ReferencePropagation.diff
@@ -99,7 +99,8 @@
           _13 = &(*_26);
           StorageLive(_15);
           _15 = RangeFull;
-          _12 = <[i32; 10] as Index<RangeFull>>::index(move _13, move _15) -> [return: bb5, unwind continue];
+-         _12 = <[i32; 10] as Index<RangeFull>>::index(move _13, move _15) -> [return: bb5, unwind continue];
++         _12 = <[i32; 10] as Index<RangeFull>>::index(copy _13, move _15) -> [return: bb5, unwind continue];
       }
   
       bb5: {
diff --git a/tests/mir-opt/reference_prop.reference_propagation.ReferencePropagation.diff b/tests/mir-opt/reference_prop.reference_propagation.ReferencePropagation.diff
index 3c6a9a9614c..0f90cc40a3d 100644
--- a/tests/mir-opt/reference_prop.reference_propagation.ReferencePropagation.diff
+++ b/tests/mir-opt/reference_prop.reference_propagation.ReferencePropagation.diff
@@ -218,8 +218,9 @@
 -         StorageLive(_14);
 -         _14 = &_11;
 -         _13 = &(*_14);
+-         _12 = move _13;
 +         _13 = &_11;
-          _12 = move _13;
++         _12 = copy _13;
           StorageDead(_13);
 -         StorageDead(_14);
           StorageLive(_15);
@@ -252,7 +253,8 @@
           StorageLive(_23);
           StorageLive(_24);
           _24 = copy _21;
-          _23 = opaque::<&&usize>(move _24) -> [return: bb3, unwind continue];
+-         _23 = opaque::<&&usize>(move _24) -> [return: bb3, unwind continue];
++         _23 = opaque::<&&usize>(copy _24) -> [return: bb3, unwind continue];
       }
   
       bb3: {
@@ -276,7 +278,8 @@
           StorageLive(_30);
           StorageLive(_31);
           _31 = copy _28;
-          _30 = opaque::<*mut &usize>(move _31) -> [return: bb4, unwind continue];
+-         _30 = opaque::<*mut &usize>(move _31) -> [return: bb4, unwind continue];
++         _30 = opaque::<*mut &usize>(copy _31) -> [return: bb4, unwind continue];
       }
   
       bb4: {
@@ -299,7 +302,8 @@
           StorageLive(_36);
           StorageLive(_37);
           _37 = copy _34;
-          _36 = opaque::<&usize>(move _37) -> [return: bb5, unwind continue];
+-         _36 = opaque::<&usize>(move _37) -> [return: bb5, unwind continue];
++         _36 = opaque::<&usize>(copy _37) -> [return: bb5, unwind continue];
       }
   
       bb5: {
@@ -328,7 +332,8 @@
           StorageLive(_45);
           StorageLive(_46);
           _46 = copy _44;
-          _45 = opaque::<&usize>(move _46) -> [return: bb6, unwind continue];
+-         _45 = opaque::<&usize>(move _46) -> [return: bb6, unwind continue];
++         _45 = opaque::<&usize>(copy _46) -> [return: bb6, unwind continue];
       }
   
       bb6: {
@@ -368,8 +373,9 @@
 -         StorageLive(_55);
 -         _55 = &(*_1);
 -         _54 = &(*_55);
+-         _2 = move _54;
 +         _54 = &(*_1);
-          _2 = move _54;
++         _2 = copy _54;
           StorageDead(_54);
 -         StorageDead(_55);
           StorageLive(_56);
diff --git a/tests/mir-opt/reference_prop.reference_propagation_const_ptr.ReferencePropagation.diff b/tests/mir-opt/reference_prop.reference_propagation_const_ptr.ReferencePropagation.diff
index 75fe99de938..99ef07a212c 100644
--- a/tests/mir-opt/reference_prop.reference_propagation_const_ptr.ReferencePropagation.diff
+++ b/tests/mir-opt/reference_prop.reference_propagation_const_ptr.ReferencePropagation.diff
@@ -233,7 +233,8 @@
           _12 = &raw const _10;
           StorageLive(_13);
           _13 = &raw const _11;
-          _12 = move _13;
+-         _12 = move _13;
++         _12 = copy _13;
           StorageDead(_13);
           StorageLive(_14);
           _14 = copy (*_12);
@@ -265,7 +266,8 @@
           StorageLive(_22);
           StorageLive(_23);
           _23 = copy _20;
-          _22 = opaque::<&*const usize>(move _23) -> [return: bb3, unwind continue];
+-         _22 = opaque::<&*const usize>(move _23) -> [return: bb3, unwind continue];
++         _22 = opaque::<&*const usize>(copy _23) -> [return: bb3, unwind continue];
       }
   
       bb3: {
@@ -289,7 +291,8 @@
           StorageLive(_29);
           StorageLive(_30);
           _30 = copy _27;
-          _29 = opaque::<*mut *const usize>(move _30) -> [return: bb4, unwind continue];
+-         _29 = opaque::<*mut *const usize>(move _30) -> [return: bb4, unwind continue];
++         _29 = opaque::<*mut *const usize>(copy _30) -> [return: bb4, unwind continue];
       }
   
       bb4: {
@@ -312,7 +315,8 @@
           StorageLive(_35);
           StorageLive(_36);
           _36 = copy _33;
-          _35 = opaque::<*const usize>(move _36) -> [return: bb5, unwind continue];
+-         _35 = opaque::<*const usize>(move _36) -> [return: bb5, unwind continue];
++         _35 = opaque::<*const usize>(copy _36) -> [return: bb5, unwind continue];
       }
   
       bb5: {
@@ -341,7 +345,8 @@
           StorageLive(_44);
           StorageLive(_45);
           _45 = copy _43;
-          _44 = opaque::<*const usize>(move _45) -> [return: bb6, unwind continue];
+-         _44 = opaque::<*const usize>(move _45) -> [return: bb6, unwind continue];
++         _44 = opaque::<*const usize>(copy _45) -> [return: bb6, unwind continue];
       }
   
       bb6: {
@@ -379,7 +384,8 @@
           _52 = &raw const (*_2);
           StorageLive(_53);
           _53 = &raw const (*_1);
-          _2 = move _53;
+-         _2 = move _53;
++         _2 = copy _53;
           StorageDead(_53);
           StorageLive(_54);
           _54 = copy (*_52);
diff --git a/tests/mir-opt/reference_prop.reference_propagation_mut.ReferencePropagation.diff b/tests/mir-opt/reference_prop.reference_propagation_mut.ReferencePropagation.diff
index f35b4974d6e..e2fab8a5f2e 100644
--- a/tests/mir-opt/reference_prop.reference_propagation_mut.ReferencePropagation.diff
+++ b/tests/mir-opt/reference_prop.reference_propagation_mut.ReferencePropagation.diff
@@ -218,8 +218,9 @@
 -         StorageLive(_14);
 -         _14 = &mut _11;
 -         _13 = &mut (*_14);
+-         _12 = move _13;
 +         _13 = &mut _11;
-          _12 = move _13;
++         _12 = copy _13;
           StorageDead(_13);
 -         StorageDead(_14);
           StorageLive(_15);
@@ -251,7 +252,8 @@
           StorageLive(_23);
           StorageLive(_24);
           _24 = copy _21;
-          _23 = opaque::<&&mut usize>(move _24) -> [return: bb3, unwind continue];
+-         _23 = opaque::<&&mut usize>(move _24) -> [return: bb3, unwind continue];
++         _23 = opaque::<&&mut usize>(copy _24) -> [return: bb3, unwind continue];
       }
   
       bb3: {
@@ -275,7 +277,8 @@
           StorageLive(_30);
           StorageLive(_31);
           _31 = copy _28;
-          _30 = opaque::<*mut &mut usize>(move _31) -> [return: bb4, unwind continue];
+-         _30 = opaque::<*mut &mut usize>(move _31) -> [return: bb4, unwind continue];
++         _30 = opaque::<*mut &mut usize>(copy _31) -> [return: bb4, unwind continue];
       }
   
       bb4: {
@@ -296,8 +299,10 @@
           _35 = copy (*_34);
           StorageLive(_36);
           StorageLive(_37);
-          _37 = move _34;
-          _36 = opaque::<&mut usize>(move _37) -> [return: bb5, unwind continue];
+-         _37 = move _34;
+-         _36 = opaque::<&mut usize>(move _37) -> [return: bb5, unwind continue];
++         _37 = copy _34;
++         _36 = opaque::<&mut usize>(copy _37) -> [return: bb5, unwind continue];
       }
   
       bb5: {
@@ -316,15 +321,19 @@
           StorageLive(_41);
           _41 = copy (*_40);
           StorageLive(_42);
-          _42 = move _40;
+-         _42 = move _40;
++         _42 = copy _40;
           StorageLive(_43);
           _43 = copy (*_42);
           StorageLive(_44);
-          _44 = move _42;
+-         _44 = move _42;
++         _44 = copy _42;
           StorageLive(_45);
           StorageLive(_46);
-          _46 = move _44;
-          _45 = opaque::<&mut usize>(move _46) -> [return: bb6, unwind continue];
+-         _46 = move _44;
+-         _45 = opaque::<&mut usize>(move _46) -> [return: bb6, unwind continue];
++         _46 = copy _44;
++         _45 = opaque::<&mut usize>(copy _46) -> [return: bb6, unwind continue];
       }
   
       bb6: {
@@ -364,8 +373,9 @@
 -         StorageLive(_55);
 -         _55 = &mut (*_1);
 -         _54 = &mut (*_55);
+-         _2 = move _54;
 +         _54 = &mut (*_1);
-          _2 = move _54;
++         _2 = copy _54;
           StorageDead(_54);
 -         StorageDead(_55);
           StorageLive(_56);
diff --git a/tests/mir-opt/reference_prop.reference_propagation_mut_ptr.ReferencePropagation.diff b/tests/mir-opt/reference_prop.reference_propagation_mut_ptr.ReferencePropagation.diff
index 21b322b7218..c49254ee6c6 100644
--- a/tests/mir-opt/reference_prop.reference_propagation_mut_ptr.ReferencePropagation.diff
+++ b/tests/mir-opt/reference_prop.reference_propagation_mut_ptr.ReferencePropagation.diff
@@ -214,7 +214,8 @@
           _12 = &raw mut _10;
           StorageLive(_13);
           _13 = &raw mut _11;
-          _12 = move _13;
+-         _12 = move _13;
++         _12 = copy _13;
           StorageDead(_13);
           StorageLive(_14);
           _14 = copy (*_12);
@@ -245,7 +246,8 @@
           StorageLive(_22);
           StorageLive(_23);
           _23 = copy _20;
-          _22 = opaque::<&*mut usize>(move _23) -> [return: bb3, unwind continue];
+-         _22 = opaque::<&*mut usize>(move _23) -> [return: bb3, unwind continue];
++         _22 = opaque::<&*mut usize>(copy _23) -> [return: bb3, unwind continue];
       }
   
       bb3: {
@@ -269,7 +271,8 @@
           StorageLive(_29);
           StorageLive(_30);
           _30 = copy _27;
-          _29 = opaque::<*mut *mut usize>(move _30) -> [return: bb4, unwind continue];
+-         _29 = opaque::<*mut *mut usize>(move _30) -> [return: bb4, unwind continue];
++         _29 = opaque::<*mut *mut usize>(copy _30) -> [return: bb4, unwind continue];
       }
   
       bb4: {
@@ -291,7 +294,8 @@
           StorageLive(_35);
           StorageLive(_36);
           _36 = copy _33;
-          _35 = opaque::<*mut usize>(move _36) -> [return: bb5, unwind continue];
+-         _35 = opaque::<*mut usize>(move _36) -> [return: bb5, unwind continue];
++         _35 = opaque::<*mut usize>(copy _36) -> [return: bb5, unwind continue];
       }
   
       bb5: {
@@ -318,7 +322,8 @@
           StorageLive(_44);
           StorageLive(_45);
           _45 = copy _43;
-          _44 = opaque::<*mut usize>(move _45) -> [return: bb6, unwind continue];
+-         _44 = opaque::<*mut usize>(move _45) -> [return: bb6, unwind continue];
++         _44 = opaque::<*mut usize>(copy _45) -> [return: bb6, unwind continue];
       }
   
       bb6: {
@@ -356,7 +361,8 @@
           _52 = &raw mut (*_2);
           StorageLive(_53);
           _53 = &raw mut (*_1);
-          _2 = move _53;
+-         _2 = move _53;
++         _2 = copy _53;
           StorageDead(_53);
           StorageLive(_54);
           _54 = copy (*_52);
diff --git a/tests/mir-opt/reference_prop.rs b/tests/mir-opt/reference_prop.rs
index 00d48938071..c4b63b6313c 100644
--- a/tests/mir-opt/reference_prop.rs
+++ b/tests/mir-opt/reference_prop.rs
@@ -30,7 +30,7 @@ fn reference_propagation<'a, T: Copy>(single: &'a T, mut multiple: &'a T) {
         // CHECK: [[a2:_.*]] = const 7_usize;
         // CHECK: [[b:_.*]] = &[[a]];
         // CHECK: [[btmp:_.*]] = &[[a2]];
-        // CHECK: [[b]] = move [[btmp]];
+        // CHECK: [[b]] = copy [[btmp]];
         // CHECK: [[c:_.*]] = copy (*[[b]]);
 
         let a = 5_usize;
@@ -122,7 +122,7 @@ fn reference_propagation<'a, T: Copy>(single: &'a T, mut multiple: &'a T) {
         // CHECK: bb7: {
         // CHECK: [[a:_.*]] = &(*_2);
         // CHECK: [[tmp:_.*]] = &(*_1);
-        // CHECK: _2 = move [[tmp]];
+        // CHECK: _2 = copy [[tmp]];
         // CHECK: [[b:_.*]] = copy (*[[a]]);
 
         let a = &*multiple;
@@ -186,7 +186,7 @@ fn reference_propagation_mut<'a, T: Copy>(single: &'a mut T, mut multiple: &'a m
         // CHECK: [[a2:_.*]] = const 7_usize;
         // CHECK: [[b:_.*]] = &mut [[a]];
         // CHECK: [[btmp:_.*]] = &mut [[a2]];
-        // CHECK: [[b]] = move [[btmp]];
+        // CHECK: [[b]] = copy [[btmp]];
         // CHECK: [[c:_.*]] = copy (*[[b]]);
 
         let mut a = 5_usize;
@@ -247,9 +247,9 @@ fn reference_propagation_mut<'a, T: Copy>(single: &'a mut T, mut multiple: &'a m
         // CHECK: [[a:_.*]] = const 7_usize;
         // CHECK: [[b1:_.*]] = &mut [[a]];
         // CHECK: [[c:_.*]] = copy (*[[b1]]);
-        // CHECK: [[b2:_.*]] = move [[b1]];
+        // CHECK: [[b2:_.*]] = copy [[b1]];
         // CHECK: [[c2:_.*]] = copy (*[[b2]]);
-        // CHECK: [[b3:_.*]] = move [[b2]];
+        // CHECK: [[b3:_.*]] = copy [[b2]];
 
         let mut a = 7_usize;
         let b1 = &mut a;
@@ -278,7 +278,7 @@ fn reference_propagation_mut<'a, T: Copy>(single: &'a mut T, mut multiple: &'a m
         // CHECK: bb7: {
         // CHECK: [[a:_.*]] = &mut (*_2);
         // CHECK: [[tmp:_.*]] = &mut (*_1);
-        // CHECK: _2 = move [[tmp]];
+        // CHECK: _2 = copy [[tmp]];
         // CHECK: [[b:_.*]] = copy (*[[a]]);
 
         let a = &mut *multiple;
@@ -343,7 +343,7 @@ fn reference_propagation_const_ptr<T: Copy>(single: *const T, mut multiple: *con
         // CHECK: [[a2:_.*]] = const 7_usize;
         // CHECK: [[b:_.*]] = &raw const [[a]];
         // CHECK: [[btmp:_.*]] = &raw const [[a2]];
-        // CHECK: [[b]] = move [[btmp]];
+        // CHECK: [[b]] = copy [[btmp]];
         // CHECK: [[c:_.*]] = copy (*[[b]]);
 
         let a = 5_usize;
@@ -435,7 +435,7 @@ fn reference_propagation_const_ptr<T: Copy>(single: *const T, mut multiple: *con
         // CHECK: bb7: {
         // CHECK: [[a:_.*]] = &raw const (*_2);
         // CHECK: [[tmp:_.*]] = &raw const (*_1);
-        // CHECK: _2 = move [[tmp]];
+        // CHECK: _2 = copy [[tmp]];
         // CHECK: [[b:_.*]] = copy (*[[a]]);
 
         let a = &raw const *multiple;
@@ -514,7 +514,7 @@ fn reference_propagation_mut_ptr<T: Copy>(single: *mut T, mut multiple: *mut T)
         // CHECK: [[a2:_.*]] = const 7_usize;
         // CHECK: [[b:_.*]] = &raw mut [[a]];
         // CHECK: [[btmp:_.*]] = &raw mut [[a2]];
-        // CHECK: [[b]] = move [[btmp]];
+        // CHECK: [[b]] = copy [[btmp]];
         // CHECK: [[c:_.*]] = copy (*[[b]]);
 
         let mut a = 5_usize;
@@ -606,7 +606,7 @@ fn reference_propagation_mut_ptr<T: Copy>(single: *mut T, mut multiple: *mut T)
         // CHECK: bb7: {
         // CHECK: [[a:_.*]] = &raw mut (*_2);
         // CHECK: [[tmp:_.*]] = &raw mut (*_1);
-        // CHECK: _2 = move [[tmp]];
+        // CHECK: _2 = copy [[tmp]];
         // CHECK: [[b:_.*]] = copy (*[[a]]);
 
         let a = &raw mut *multiple;
diff --git a/tests/mir-opt/reference_prop_do_not_reuse_move.rs b/tests/mir-opt/reference_prop_do_not_reuse_move.rs
new file mode 100644
index 00000000000..8859d30aed1
--- /dev/null
+++ b/tests/mir-opt/reference_prop_do_not_reuse_move.rs
@@ -0,0 +1,44 @@
+//@ test-mir-pass: ReferencePropagation
+
+#![feature(custom_mir, core_intrinsics)]
+#![allow(internal_features)]
+#![crate_type = "lib"]
+
+use std::intrinsics::mir::*;
+
+#[inline(never)]
+fn opaque(_: impl Sized, _: impl Sized) {}
+
+#[custom_mir(dialect = "runtime")]
+pub fn fn0() {
+    // CHECK-LABEL: fn0
+    // CHECK: _9 = opaque::<&u8, &u64>(copy (_2.1: &u8), copy _6) -> [return: bb1, unwind unreachable];
+    mir! {
+        let _1: (u8, u8);
+        let _2: (u64, &u8);
+        let _3: (u8, &&u64);
+        let _4: u64;
+        let _5: &u64;
+        let _6: &u64;
+        let _7: &u64;
+        let _8: u64;
+        let n: ();
+        {
+            _3.0 = 0;
+            _1 = (0, _3.0);
+            _4 = 0;
+            _2.1 = &_1.0;
+            _8 = 0;
+            _5 = &_8;
+            _5 = &_4;
+            _6 = _5;
+            _7 = _6;
+            _3.1 = &_6;
+            Call(n = opaque(_2.1, Move(_6)), ReturnTo(bb1), UnwindUnreachable())
+        }
+        bb1 = {
+            _2.0 = *_7;
+            Return()
+        }
+    }
+}
diff --git a/tests/mir-opt/uninhabited_not_read.main.SimplifyLocals-final.after.mir b/tests/mir-opt/uninhabited_not_read.main.SimplifyLocals-final.after.mir
index 6bf4be652be..89f4cbc2ede 100644
--- a/tests/mir-opt/uninhabited_not_read.main.SimplifyLocals-final.after.mir
+++ b/tests/mir-opt/uninhabited_not_read.main.SimplifyLocals-final.after.mir
@@ -31,7 +31,7 @@ fn main() -> () {
         StorageLive(_2);
         StorageLive(_3);
         _3 = &raw const _1;
-        _2 = move _3 as *const ! (PtrToPtr);
+        _2 = copy _3 as *const ! (PtrToPtr);
         StorageDead(_3);
         StorageDead(_2);
         StorageDead(_1);
@@ -40,7 +40,7 @@ fn main() -> () {
         StorageLive(_5);
         StorageLive(_6);
         _6 = &raw const _4;
-        _5 = move _6 as *const ! (PtrToPtr);
+        _5 = copy _6 as *const ! (PtrToPtr);
         StorageDead(_6);
         StorageDead(_5);
         StorageDead(_4);