Const-prop pointers.

compiler/rustc_mir_transform/src/gvn.rs

@@ -561,6 +561,19 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
                         .ok()?;
                     dest.into()
                 }
+                CastKind::FnPtrToPtr
+                | CastKind::PtrToPtr
+                | CastKind::PointerCoercion(
+                    ty::adjustment::PointerCoercion::MutToConstPointer
+                    | ty::adjustment::PointerCoercion::ArrayToPointer
+                    | ty::adjustment::PointerCoercion::UnsafeFnPointer,
+                ) => {
+                    let src = self.evaluated[value].as_ref()?;
+                    let src = self.ecx.read_immediate(src).ok()?;
+                    let to = self.ecx.layout_of(to).ok()?;
+                    let ret = self.ecx.ptr_to_ptr(&src, to).ok()?;
+                    ret.into()
+                }
                 _ => return None,
             },
         };

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

@@ -69,28 +69,40 @@
       }
   
       bb2: {
-          _10 = const {0x1 as *mut [bool; 0]} as *mut () (PtrToPtr);
+          _10 = const {0x1 as *mut ()};
-          _9 = NonNull::<T>::new_unchecked::precondition_check(move _10) -> [return: bb3, unwind unreachable];
+          _9 = NonNull::<T>::new_unchecked::precondition_check(const {0x1 as *mut ()}) -> [return: bb3, unwind unreachable];
       }
   
       bb3: {
           StorageDead(_8);
-          _11 = const {0x1 as *mut [bool; 0]} as *const [bool; 0] (PointerCoercion(MutToConstPointer));
+          _11 = const {0x1 as *const [bool; 0]};
-          _5 = NonNull::<[bool; 0]> { pointer: _11 };
+          _5 = const NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }};
           StorageDead(_11);
           StorageDead(_10);
           StorageDead(_6);
-          _4 = Unique::<[bool; 0]> { pointer: move _5, _marker: const PhantomData::<[bool; 0]> };
+          _4 = const Unique::<[bool; 0]> {{ pointer: NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }}, _marker: PhantomData::<[bool; 0]> }};
           StorageDead(_5);
-          _3 = move _4 as std::ptr::Unique<[bool]> (PointerCoercion(Unsize));
+          _3 = const Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC0, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }};
           StorageDead(_4);
-          _2 = Box::<[bool]>(_3, const std::alloc::Global);
+          _2 = const Box::<[bool]>(Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC1, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }}, std::alloc::Global);
           StorageDead(_9);
           StorageDead(_3);
-          _1 = A { foo: move _2 };
+          _1 = const A {{ foo: Box::<[bool]>(Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC2, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }}, std::alloc::Global) }};
           StorageDead(_2);
           _0 = const ();
           drop(_1) -> [return: bb1, unwind unreachable];
       }
   }
   
+  ALLOC2 (size: 8, align: 4) {
+      01 00 00 00 00 00 00 00                         │ ........
+  }
+  
+  ALLOC1 (size: 8, align: 4) {
+      01 00 00 00 00 00 00 00                         │ ........
+  }
+  
+  ALLOC0 (size: 8, align: 4) {
+      01 00 00 00 00 00 00 00                         │ ........
+  }
+  

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

@@ -73,28 +73,40 @@
       }
   
       bb3: {
-          _10 = const {0x1 as *mut [bool; 0]} as *mut () (PtrToPtr);
+          _10 = const {0x1 as *mut ()};
-          _9 = NonNull::<T>::new_unchecked::precondition_check(move _10) -> [return: bb4, unwind unreachable];
+          _9 = NonNull::<T>::new_unchecked::precondition_check(const {0x1 as *mut ()}) -> [return: bb4, unwind unreachable];
       }
   
       bb4: {
           StorageDead(_8);
-          _11 = const {0x1 as *mut [bool; 0]} as *const [bool; 0] (PointerCoercion(MutToConstPointer));
+          _11 = const {0x1 as *const [bool; 0]};
-          _5 = NonNull::<[bool; 0]> { pointer: _11 };
+          _5 = const NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }};
           StorageDead(_11);
           StorageDead(_10);
           StorageDead(_6);
-          _4 = Unique::<[bool; 0]> { pointer: move _5, _marker: const PhantomData::<[bool; 0]> };
+          _4 = const Unique::<[bool; 0]> {{ pointer: NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }}, _marker: PhantomData::<[bool; 0]> }};
           StorageDead(_5);
-          _3 = move _4 as std::ptr::Unique<[bool]> (PointerCoercion(Unsize));
+          _3 = const Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC0, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }};
           StorageDead(_4);
-          _2 = Box::<[bool]>(_3, const std::alloc::Global);
+          _2 = const Box::<[bool]>(Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC1, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }}, std::alloc::Global);
           StorageDead(_9);
           StorageDead(_3);
-          _1 = A { foo: move _2 };
+          _1 = const A {{ foo: Box::<[bool]>(Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC2, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }}, std::alloc::Global) }};
           StorageDead(_2);
           _0 = const ();
           drop(_1) -> [return: bb1, unwind: bb2];
       }
   }
   
+  ALLOC2 (size: 8, align: 4) {
+      01 00 00 00 00 00 00 00                         │ ........
+  }
+  
+  ALLOC1 (size: 8, align: 4) {
+      01 00 00 00 00 00 00 00                         │ ........
+  }
+  
+  ALLOC0 (size: 8, align: 4) {
+      01 00 00 00 00 00 00 00                         │ ........
+  }
+  

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

@@ -69,28 +69,40 @@
       }
   
       bb2: {
-          _10 = const {0x1 as *mut [bool; 0]} as *mut () (PtrToPtr);
+          _10 = const {0x1 as *mut ()};
-          _9 = NonNull::<T>::new_unchecked::precondition_check(move _10) -> [return: bb3, unwind unreachable];
+          _9 = NonNull::<T>::new_unchecked::precondition_check(const {0x1 as *mut ()}) -> [return: bb3, unwind unreachable];
       }
   
       bb3: {
           StorageDead(_8);
-          _11 = const {0x1 as *mut [bool; 0]} as *const [bool; 0] (PointerCoercion(MutToConstPointer));
+          _11 = const {0x1 as *const [bool; 0]};
-          _5 = NonNull::<[bool; 0]> { pointer: _11 };
+          _5 = const NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }};
           StorageDead(_11);
           StorageDead(_10);
           StorageDead(_6);
-          _4 = Unique::<[bool; 0]> { pointer: move _5, _marker: const PhantomData::<[bool; 0]> };
+          _4 = const Unique::<[bool; 0]> {{ pointer: NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }}, _marker: PhantomData::<[bool; 0]> }};
           StorageDead(_5);
-          _3 = move _4 as std::ptr::Unique<[bool]> (PointerCoercion(Unsize));
+          _3 = const Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC0, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }};
           StorageDead(_4);
-          _2 = Box::<[bool]>(_3, const std::alloc::Global);
+          _2 = const Box::<[bool]>(Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC1, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }}, std::alloc::Global);
           StorageDead(_9);
           StorageDead(_3);
-          _1 = A { foo: move _2 };
+          _1 = const A {{ foo: Box::<[bool]>(Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC2, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }}, std::alloc::Global) }};
           StorageDead(_2);
           _0 = const ();
           drop(_1) -> [return: bb1, unwind unreachable];
       }
   }
   
+  ALLOC2 (size: 16, align: 8) {
+      01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
+  }
+  
+  ALLOC1 (size: 16, align: 8) {
+      01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
+  }
+  
+  ALLOC0 (size: 16, align: 8) {
+      01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
+  }
+  

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

@@ -73,28 +73,40 @@
       }
   
       bb3: {
-          _10 = const {0x1 as *mut [bool; 0]} as *mut () (PtrToPtr);
+          _10 = const {0x1 as *mut ()};
-          _9 = NonNull::<T>::new_unchecked::precondition_check(move _10) -> [return: bb4, unwind unreachable];
+          _9 = NonNull::<T>::new_unchecked::precondition_check(const {0x1 as *mut ()}) -> [return: bb4, unwind unreachable];
       }
   
       bb4: {
           StorageDead(_8);
-          _11 = const {0x1 as *mut [bool; 0]} as *const [bool; 0] (PointerCoercion(MutToConstPointer));
+          _11 = const {0x1 as *const [bool; 0]};
-          _5 = NonNull::<[bool; 0]> { pointer: _11 };
+          _5 = const NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }};
           StorageDead(_11);
           StorageDead(_10);
           StorageDead(_6);
-          _4 = Unique::<[bool; 0]> { pointer: move _5, _marker: const PhantomData::<[bool; 0]> };
+          _4 = const Unique::<[bool; 0]> {{ pointer: NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }}, _marker: PhantomData::<[bool; 0]> }};
           StorageDead(_5);
-          _3 = move _4 as std::ptr::Unique<[bool]> (PointerCoercion(Unsize));
+          _3 = const Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC0, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }};
           StorageDead(_4);
-          _2 = Box::<[bool]>(_3, const std::alloc::Global);
+          _2 = const Box::<[bool]>(Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC1, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }}, std::alloc::Global);
           StorageDead(_9);
           StorageDead(_3);
-          _1 = A { foo: move _2 };
+          _1 = const A {{ foo: Box::<[bool]>(Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC2, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }}, std::alloc::Global) }};
           StorageDead(_2);
           _0 = const ();
           drop(_1) -> [return: bb1, unwind: bb2];
       }
   }
   
+  ALLOC2 (size: 16, align: 8) {
+      01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
+  }
+  
+  ALLOC1 (size: 16, align: 8) {
+      01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
+  }
+  
+  ALLOC0 (size: 16, align: 8) {
+      01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
+  }
+  

tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.GVN.32bit.panic-abort.diff

@@ -72,29 +72,47 @@
   
       bb2: {
 -         _10 = _6 as *mut () (PtrToPtr);
-+         _10 = const {0x1 as *mut [bool; 0]} as *mut () (PtrToPtr);
+-         _9 = NonNull::<T>::new_unchecked::precondition_check(move _10) -> [return: bb3, unwind unreachable];
-          _9 = NonNull::<T>::new_unchecked::precondition_check(move _10) -> [return: bb3, unwind unreachable];
++         _10 = const {0x1 as *mut ()};
++         _9 = NonNull::<T>::new_unchecked::precondition_check(const {0x1 as *mut ()}) -> [return: bb3, unwind unreachable];
       }
   
       bb3: {
           StorageDead(_8);
 -         _11 = _6 as *const [bool; 0] (PointerCoercion(MutToConstPointer));
-+         _11 = const {0x1 as *mut [bool; 0]} as *const [bool; 0] (PointerCoercion(MutToConstPointer));
+-         _5 = NonNull::<[bool; 0]> { pointer: _11 };
-          _5 = NonNull::<[bool; 0]> { pointer: _11 };
++         _11 = const {0x1 as *const [bool; 0]};
++         _5 = const NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }};
           StorageDead(_11);
           StorageDead(_10);
           StorageDead(_6);
-          _4 = Unique::<[bool; 0]> { pointer: move _5, _marker: const PhantomData::<[bool; 0]> };
+-         _4 = Unique::<[bool; 0]> { pointer: move _5, _marker: const PhantomData::<[bool; 0]> };
++         _4 = const Unique::<[bool; 0]> {{ pointer: NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }}, _marker: PhantomData::<[bool; 0]> }};
           StorageDead(_5);
-          _3 = move _4 as std::ptr::Unique<[bool]> (PointerCoercion(Unsize));
+-         _3 = move _4 as std::ptr::Unique<[bool]> (PointerCoercion(Unsize));
++         _3 = const Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC0, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }};
           StorageDead(_4);
-          _2 = Box::<[bool]>(_3, const std::alloc::Global);
+-         _2 = Box::<[bool]>(_3, const std::alloc::Global);
++         _2 = const Box::<[bool]>(Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC1, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }}, std::alloc::Global);
           StorageDead(_9);
           StorageDead(_3);
-          _1 = A { foo: move _2 };
+-         _1 = A { foo: move _2 };
++         _1 = const A {{ foo: Box::<[bool]>(Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC2, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }}, std::alloc::Global) }};
           StorageDead(_2);
           _0 = const ();
           drop(_1) -> [return: bb1, unwind unreachable];
       }
++ }
++ 
++ ALLOC2 (size: 8, align: 4) {
++     01 00 00 00 00 00 00 00                         │ ........
++ }
++ 
++ ALLOC1 (size: 8, align: 4) {
++     01 00 00 00 00 00 00 00                         │ ........
++ }
++ 
++ ALLOC0 (size: 8, align: 4) {
++     01 00 00 00 00 00 00 00                         │ ........
   }
   

tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.GVN.32bit.panic-unwind.diff

@@ -76,29 +76,47 @@
   
       bb3: {
 -         _10 = _6 as *mut () (PtrToPtr);
-+         _10 = const {0x1 as *mut [bool; 0]} as *mut () (PtrToPtr);
+-         _9 = NonNull::<T>::new_unchecked::precondition_check(move _10) -> [return: bb4, unwind unreachable];
-          _9 = NonNull::<T>::new_unchecked::precondition_check(move _10) -> [return: bb4, unwind unreachable];
++         _10 = const {0x1 as *mut ()};
++         _9 = NonNull::<T>::new_unchecked::precondition_check(const {0x1 as *mut ()}) -> [return: bb4, unwind unreachable];
       }
   
       bb4: {
           StorageDead(_8);
 -         _11 = _6 as *const [bool; 0] (PointerCoercion(MutToConstPointer));
-+         _11 = const {0x1 as *mut [bool; 0]} as *const [bool; 0] (PointerCoercion(MutToConstPointer));
+-         _5 = NonNull::<[bool; 0]> { pointer: _11 };
-          _5 = NonNull::<[bool; 0]> { pointer: _11 };
++         _11 = const {0x1 as *const [bool; 0]};
++         _5 = const NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }};
           StorageDead(_11);
           StorageDead(_10);
           StorageDead(_6);
-          _4 = Unique::<[bool; 0]> { pointer: move _5, _marker: const PhantomData::<[bool; 0]> };
+-         _4 = Unique::<[bool; 0]> { pointer: move _5, _marker: const PhantomData::<[bool; 0]> };
++         _4 = const Unique::<[bool; 0]> {{ pointer: NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }}, _marker: PhantomData::<[bool; 0]> }};
           StorageDead(_5);
-          _3 = move _4 as std::ptr::Unique<[bool]> (PointerCoercion(Unsize));
+-         _3 = move _4 as std::ptr::Unique<[bool]> (PointerCoercion(Unsize));
++         _3 = const Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC0, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }};
           StorageDead(_4);
-          _2 = Box::<[bool]>(_3, const std::alloc::Global);
+-         _2 = Box::<[bool]>(_3, const std::alloc::Global);
++         _2 = const Box::<[bool]>(Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC1, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }}, std::alloc::Global);
           StorageDead(_9);
           StorageDead(_3);
-          _1 = A { foo: move _2 };
+-         _1 = A { foo: move _2 };
++         _1 = const A {{ foo: Box::<[bool]>(Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC2, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }}, std::alloc::Global) }};
           StorageDead(_2);
           _0 = const ();
           drop(_1) -> [return: bb1, unwind: bb2];
       }
++ }
++ 
++ ALLOC2 (size: 8, align: 4) {
++     01 00 00 00 00 00 00 00                         │ ........
++ }
++ 
++ ALLOC1 (size: 8, align: 4) {
++     01 00 00 00 00 00 00 00                         │ ........
++ }
++ 
++ ALLOC0 (size: 8, align: 4) {
++     01 00 00 00 00 00 00 00                         │ ........
   }
   

tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.GVN.64bit.panic-abort.diff

@@ -72,29 +72,47 @@
   
       bb2: {
 -         _10 = _6 as *mut () (PtrToPtr);
-+         _10 = const {0x1 as *mut [bool; 0]} as *mut () (PtrToPtr);
+-         _9 = NonNull::<T>::new_unchecked::precondition_check(move _10) -> [return: bb3, unwind unreachable];
-          _9 = NonNull::<T>::new_unchecked::precondition_check(move _10) -> [return: bb3, unwind unreachable];
++         _10 = const {0x1 as *mut ()};
++         _9 = NonNull::<T>::new_unchecked::precondition_check(const {0x1 as *mut ()}) -> [return: bb3, unwind unreachable];
       }
   
       bb3: {
           StorageDead(_8);
 -         _11 = _6 as *const [bool; 0] (PointerCoercion(MutToConstPointer));
-+         _11 = const {0x1 as *mut [bool; 0]} as *const [bool; 0] (PointerCoercion(MutToConstPointer));
+-         _5 = NonNull::<[bool; 0]> { pointer: _11 };
-          _5 = NonNull::<[bool; 0]> { pointer: _11 };
++         _11 = const {0x1 as *const [bool; 0]};
++         _5 = const NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }};
           StorageDead(_11);
           StorageDead(_10);
           StorageDead(_6);
-          _4 = Unique::<[bool; 0]> { pointer: move _5, _marker: const PhantomData::<[bool; 0]> };
+-         _4 = Unique::<[bool; 0]> { pointer: move _5, _marker: const PhantomData::<[bool; 0]> };
++         _4 = const Unique::<[bool; 0]> {{ pointer: NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }}, _marker: PhantomData::<[bool; 0]> }};
           StorageDead(_5);
-          _3 = move _4 as std::ptr::Unique<[bool]> (PointerCoercion(Unsize));
+-         _3 = move _4 as std::ptr::Unique<[bool]> (PointerCoercion(Unsize));
++         _3 = const Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC0, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }};
           StorageDead(_4);
-          _2 = Box::<[bool]>(_3, const std::alloc::Global);
+-         _2 = Box::<[bool]>(_3, const std::alloc::Global);
++         _2 = const Box::<[bool]>(Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC1, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }}, std::alloc::Global);
           StorageDead(_9);
           StorageDead(_3);
-          _1 = A { foo: move _2 };
+-         _1 = A { foo: move _2 };
++         _1 = const A {{ foo: Box::<[bool]>(Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC2, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }}, std::alloc::Global) }};
           StorageDead(_2);
           _0 = const ();
           drop(_1) -> [return: bb1, unwind unreachable];
       }
++ }
++ 
++ ALLOC2 (size: 16, align: 8) {
++     01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
++ }
++ 
++ ALLOC1 (size: 16, align: 8) {
++     01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
++ }
++ 
++ ALLOC0 (size: 16, align: 8) {
++     01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
   }
   

tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.GVN.64bit.panic-unwind.diff

@@ -76,29 +76,47 @@
   
       bb3: {
 -         _10 = _6 as *mut () (PtrToPtr);
-+         _10 = const {0x1 as *mut [bool; 0]} as *mut () (PtrToPtr);
+-         _9 = NonNull::<T>::new_unchecked::precondition_check(move _10) -> [return: bb4, unwind unreachable];
-          _9 = NonNull::<T>::new_unchecked::precondition_check(move _10) -> [return: bb4, unwind unreachable];
++         _10 = const {0x1 as *mut ()};
++         _9 = NonNull::<T>::new_unchecked::precondition_check(const {0x1 as *mut ()}) -> [return: bb4, unwind unreachable];
       }
   
       bb4: {
           StorageDead(_8);
 -         _11 = _6 as *const [bool; 0] (PointerCoercion(MutToConstPointer));
-+         _11 = const {0x1 as *mut [bool; 0]} as *const [bool; 0] (PointerCoercion(MutToConstPointer));
+-         _5 = NonNull::<[bool; 0]> { pointer: _11 };
-          _5 = NonNull::<[bool; 0]> { pointer: _11 };
++         _11 = const {0x1 as *const [bool; 0]};
++         _5 = const NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }};
           StorageDead(_11);
           StorageDead(_10);
           StorageDead(_6);
-          _4 = Unique::<[bool; 0]> { pointer: move _5, _marker: const PhantomData::<[bool; 0]> };
+-         _4 = Unique::<[bool; 0]> { pointer: move _5, _marker: const PhantomData::<[bool; 0]> };
++         _4 = const Unique::<[bool; 0]> {{ pointer: NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }}, _marker: PhantomData::<[bool; 0]> }};
           StorageDead(_5);
-          _3 = move _4 as std::ptr::Unique<[bool]> (PointerCoercion(Unsize));
+-         _3 = move _4 as std::ptr::Unique<[bool]> (PointerCoercion(Unsize));
++         _3 = const Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC0, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }};
           StorageDead(_4);
-          _2 = Box::<[bool]>(_3, const std::alloc::Global);
+-         _2 = Box::<[bool]>(_3, const std::alloc::Global);
++         _2 = const Box::<[bool]>(Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC1, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }}, std::alloc::Global);
           StorageDead(_9);
           StorageDead(_3);
-          _1 = A { foo: move _2 };
+-         _1 = A { foo: move _2 };
++         _1 = const A {{ foo: Box::<[bool]>(Unique::<[bool]> {{ pointer: NonNull::<[bool]> {{ pointer: Indirect { alloc_id: ALLOC2, offset: Size(0 bytes) }: *const [bool] }}, _marker: PhantomData::<[bool]> }}, std::alloc::Global) }};
           StorageDead(_2);
           _0 = const ();
           drop(_1) -> [return: bb1, unwind: bb2];
       }
++ }
++ 
++ ALLOC2 (size: 16, align: 8) {
++     01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
++ }
++ 
++ ALLOC1 (size: 16, align: 8) {
++     01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
++ }
++ 
++ ALLOC0 (size: 16, align: 8) {
++     01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 │ ................
   }
   

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

@@ -16,14 +16,11 @@ struct A {
 // CHECK-LABEL: fn main(
 fn main() {
     // ConstProp will create a constant of type `Box<[bool]>`.
-    // FIXME: it is not yet a constant.
-
     // Verify that `DataflowConstProp` does not ICE trying to dereference it directly.
 
     // CHECK: debug a => [[a:_.*]];
     // We may check other inlined functions as well...
 
-    // CHECK: {{_.*}} = Box::<[bool]>(
+    // CHECK: {{_.*}} = const Box::<[bool]>(
-    // FIXME: should be `{{_.*}} = const Box::<[bool]>`
     let a: A = A { foo: Box::default() };
 }