Drive-by-cleanup: Don't emit `thir::ExprKind::NeverToAny` for `! -> !`

16 files changed, 77 insertions, 135 deletions

diff --git a/compiler/rustc_mir_build/src/thir/cx/expr.rs b/compiler/rustc_mir_build/src/thir/cx/expr.rs
index f46eb5a0ce1..c8648224ac1 100644
--- a/compiler/rustc_mir_build/src/thir/cx/expr.rs
+++ b/compiler/rustc_mir_build/src/thir/cx/expr.rs
@@ -130,6 +130,7 @@ impl<'tcx> Cx<'tcx> {
                 ExprKind::Pointer { cast: PointerCast::Unsize, source: self.thir.exprs.push(expr) }
             }
             Adjust::Pointer(cast) => ExprKind::Pointer { cast, source: self.thir.exprs.push(expr) },
+            Adjust::NeverToAny if adjustment.target.is_never() => return expr,
             Adjust::NeverToAny => ExprKind::NeverToAny { source: self.thir.exprs.push(expr) },
             Adjust::Deref(None) => {
                 adjust_span(&mut expr);
diff --git a/src/tools/miri/tests/fail/never_say_never.rs b/src/tools/miri/tests/fail/never_say_never.rs
index f6d3dc790bf..fd082e367a8 100644
--- a/src/tools/miri/tests/fail/never_say_never.rs
+++ b/src/tools/miri/tests/fail/never_say_never.rs
@@ -6,10 +6,8 @@
 
 fn main() {
     let y = &5;
-    let x: ! = unsafe {
-        *(y as *const _ as *const !) //~ ERROR: entering unreachable code
-    };
-    f(x)
+    let x: ! = unsafe { *(y as *const _ as *const !) };
+    f(x) //~ ERROR: entering unreachable code
 }
 
 fn f(x: !) -> ! {
diff --git a/src/tools/miri/tests/fail/never_say_never.stderr b/src/tools/miri/tests/fail/never_say_never.stderr
index a2a63b8baf5..9d3a8df525a 100644
--- a/src/tools/miri/tests/fail/never_say_never.stderr
+++ b/src/tools/miri/tests/fail/never_say_never.stderr
@@ -1,8 +1,8 @@
 error: Undefined Behavior: entering unreachable code
   --> $DIR/never_say_never.rs:LL:CC
    |
-LL |         *(y as *const _ as *const !)
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ entering unreachable code
+LL |     f(x)
+   |     ^^^^ entering unreachable code
    |
    = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
    = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
diff --git a/tests/mir-opt/const_prop/transmute.unreachable_box.ConstProp.32bit.diff b/tests/mir-opt/const_prop/transmute.unreachable_box.ConstProp.32bit.diff
index bc41b5d0813..5258d75bdf7 100644
--- a/tests/mir-opt/const_prop/transmute.unreachable_box.ConstProp.32bit.diff
+++ b/tests/mir-opt/const_prop/transmute.unreachable_box.ConstProp.32bit.diff
@@ -3,24 +3,20 @@
   
   fn unreachable_box() -> ! {
       let mut _0: !;                       // return place in scope 0 at $DIR/transmute.rs:+0:36: +0:37
-      let mut _1: !;                       // in scope 0 at $DIR/transmute.rs:+0:38: +3:2
-      let _2: std::boxed::Box<Never>;      // in scope 0 at $DIR/transmute.rs:+1:9: +1:10
-      let mut _3: !;                       // in scope 0 at $DIR/transmute.rs:+2:5: +2:16
+      let _1: std::boxed::Box<Never>;      // in scope 0 at $DIR/transmute.rs:+1:9: +1:10
       scope 1 {
-          debug x => _2;                   // in scope 1 at $DIR/transmute.rs:+1:9: +1:10
+          debug x => _1;                   // in scope 1 at $DIR/transmute.rs:+1:9: +1:10
       }
       scope 2 {
       }
   
       bb0: {
-          StorageLive(_1);                 // scope 0 at $DIR/transmute.rs:+0:38: +3:2
-          StorageLive(_2);                 // scope 0 at $DIR/transmute.rs:+1:9: +1:10
--         _2 = const 1_usize as std::boxed::Box<Never> (Transmute); // scope 2 at $DIR/transmute.rs:+1:34: +1:52
-+         _2 = const Box::<Never>(Unique::<Never> {{ pointer: NonNull::<Never> {{ pointer: {0x1 as *const Never} }}, _marker: PhantomData::<Never> }}, std::alloc::Global); // scope 2 at $DIR/transmute.rs:+1:34: +1:52
+          StorageLive(_1);                 // scope 0 at $DIR/transmute.rs:+1:9: +1:10
+-         _1 = const 1_usize as std::boxed::Box<Never> (Transmute); // scope 2 at $DIR/transmute.rs:+1:34: +1:52
++         _1 = const Box::<Never>(Unique::<Never> {{ pointer: NonNull::<Never> {{ pointer: {0x1 as *const Never} }}, _marker: PhantomData::<Never> }}, std::alloc::Global); // scope 2 at $DIR/transmute.rs:+1:34: +1:52
 +                                          // mir::Constant
 +                                          // + span: no-location
 +                                          // + literal: Const { ty: Box<Never>, val: Value(Scalar(0x00000001)) }
-          StorageLive(_3);                 // scope 1 at $DIR/transmute.rs:+2:5: +2:16
           unreachable;                     // scope 1 at $DIR/transmute.rs:+2:11: +2:13
       }
   }
diff --git a/tests/mir-opt/const_prop/transmute.unreachable_box.ConstProp.64bit.diff b/tests/mir-opt/const_prop/transmute.unreachable_box.ConstProp.64bit.diff
index c4376e6e17a..7e57e06a5cf 100644
--- a/tests/mir-opt/const_prop/transmute.unreachable_box.ConstProp.64bit.diff
+++ b/tests/mir-opt/const_prop/transmute.unreachable_box.ConstProp.64bit.diff
@@ -3,24 +3,20 @@
   
   fn unreachable_box() -> ! {
       let mut _0: !;                       // return place in scope 0 at $DIR/transmute.rs:+0:36: +0:37
-      let mut _1: !;                       // in scope 0 at $DIR/transmute.rs:+0:38: +3:2
-      let _2: std::boxed::Box<Never>;      // in scope 0 at $DIR/transmute.rs:+1:9: +1:10
-      let mut _3: !;                       // in scope 0 at $DIR/transmute.rs:+2:5: +2:16
+      let _1: std::boxed::Box<Never>;      // in scope 0 at $DIR/transmute.rs:+1:9: +1:10
       scope 1 {
-          debug x => _2;                   // in scope 1 at $DIR/transmute.rs:+1:9: +1:10
+          debug x => _1;                   // in scope 1 at $DIR/transmute.rs:+1:9: +1:10
       }
       scope 2 {
       }
   
       bb0: {
-          StorageLive(_1);                 // scope 0 at $DIR/transmute.rs:+0:38: +3:2
-          StorageLive(_2);                 // scope 0 at $DIR/transmute.rs:+1:9: +1:10
--         _2 = const 1_usize as std::boxed::Box<Never> (Transmute); // scope 2 at $DIR/transmute.rs:+1:34: +1:52
-+         _2 = const Box::<Never>(Unique::<Never> {{ pointer: NonNull::<Never> {{ pointer: {0x1 as *const Never} }}, _marker: PhantomData::<Never> }}, std::alloc::Global); // scope 2 at $DIR/transmute.rs:+1:34: +1:52
+          StorageLive(_1);                 // scope 0 at $DIR/transmute.rs:+1:9: +1:10
+-         _1 = const 1_usize as std::boxed::Box<Never> (Transmute); // scope 2 at $DIR/transmute.rs:+1:34: +1:52
++         _1 = const Box::<Never>(Unique::<Never> {{ pointer: NonNull::<Never> {{ pointer: {0x1 as *const Never} }}, _marker: PhantomData::<Never> }}, std::alloc::Global); // scope 2 at $DIR/transmute.rs:+1:34: +1:52
 +                                          // mir::Constant
 +                                          // + span: no-location
 +                                          // + literal: Const { ty: Box<Never>, val: Value(Scalar(0x0000000000000001)) }
-          StorageLive(_3);                 // scope 1 at $DIR/transmute.rs:+2:5: +2:16
           unreachable;                     // scope 1 at $DIR/transmute.rs:+2:11: +2:13
       }
   }
diff --git a/tests/mir-opt/const_prop/transmute.unreachable_direct.ConstProp.32bit.diff b/tests/mir-opt/const_prop/transmute.unreachable_direct.ConstProp.32bit.diff
index 81b7b368993..032681f230b 100644
--- a/tests/mir-opt/const_prop/transmute.unreachable_direct.ConstProp.32bit.diff
+++ b/tests/mir-opt/const_prop/transmute.unreachable_direct.ConstProp.32bit.diff
@@ -3,22 +3,19 @@
   
   fn unreachable_direct() -> ! {
       let mut _0: !;                       // return place in scope 0 at $DIR/transmute.rs:+0:39: +0:40
-      let mut _1: !;                       // in scope 0 at $DIR/transmute.rs:+0:41: +3:2
-      let _2: Never;                       // in scope 0 at $DIR/transmute.rs:+1:9: +1:10
-      let mut _3: ();                      // in scope 0 at $DIR/transmute.rs:+1:39: +1:41
-      let mut _4: !;                       // in scope 0 at $DIR/transmute.rs:+2:5: +2:15
+      let _1: Never;                       // in scope 0 at $DIR/transmute.rs:+1:9: +1:10
+      let mut _2: ();                      // in scope 0 at $DIR/transmute.rs:+1:39: +1:41
       scope 1 {
-          debug x => _2;                   // in scope 1 at $DIR/transmute.rs:+1:9: +1:10
+          debug x => _1;                   // in scope 1 at $DIR/transmute.rs:+1:9: +1:10
       }
       scope 2 {
       }
   
       bb0: {
-          StorageLive(_1);                 // scope 0 at $DIR/transmute.rs:+0:41: +3:2
-          StorageLive(_2);                 // scope 0 at $DIR/transmute.rs:+1:9: +1:10
-          StorageLive(_3);                 // scope 2 at $DIR/transmute.rs:+1:39: +1:41
-          _3 = ();                         // scope 2 at $DIR/transmute.rs:+1:39: +1:41
-          _2 = move _3 as Never (Transmute); // scope 2 at $DIR/transmute.rs:+1:29: +1:42
+          StorageLive(_1);                 // scope 0 at $DIR/transmute.rs:+1:9: +1:10
+          StorageLive(_2);                 // scope 2 at $DIR/transmute.rs:+1:39: +1:41
+          _2 = ();                         // scope 2 at $DIR/transmute.rs:+1:39: +1:41
+          _1 = move _2 as Never (Transmute); // scope 2 at $DIR/transmute.rs:+1:29: +1:42
           unreachable;                     // scope 2 at $DIR/transmute.rs:+1:29: +1:42
       }
   }
diff --git a/tests/mir-opt/const_prop/transmute.unreachable_direct.ConstProp.64bit.diff b/tests/mir-opt/const_prop/transmute.unreachable_direct.ConstProp.64bit.diff
index 81b7b368993..032681f230b 100644
--- a/tests/mir-opt/const_prop/transmute.unreachable_direct.ConstProp.64bit.diff
+++ b/tests/mir-opt/const_prop/transmute.unreachable_direct.ConstProp.64bit.diff
@@ -3,22 +3,19 @@
   
   fn unreachable_direct() -> ! {
       let mut _0: !;                       // return place in scope 0 at $DIR/transmute.rs:+0:39: +0:40
-      let mut _1: !;                       // in scope 0 at $DIR/transmute.rs:+0:41: +3:2
-      let _2: Never;                       // in scope 0 at $DIR/transmute.rs:+1:9: +1:10
-      let mut _3: ();                      // in scope 0 at $DIR/transmute.rs:+1:39: +1:41
-      let mut _4: !;                       // in scope 0 at $DIR/transmute.rs:+2:5: +2:15
+      let _1: Never;                       // in scope 0 at $DIR/transmute.rs:+1:9: +1:10
+      let mut _2: ();                      // in scope 0 at $DIR/transmute.rs:+1:39: +1:41
       scope 1 {
-          debug x => _2;                   // in scope 1 at $DIR/transmute.rs:+1:9: +1:10
+          debug x => _1;                   // in scope 1 at $DIR/transmute.rs:+1:9: +1:10
       }
       scope 2 {
       }
   
       bb0: {
-          StorageLive(_1);                 // scope 0 at $DIR/transmute.rs:+0:41: +3:2
-          StorageLive(_2);                 // scope 0 at $DIR/transmute.rs:+1:9: +1:10
-          StorageLive(_3);                 // scope 2 at $DIR/transmute.rs:+1:39: +1:41
-          _3 = ();                         // scope 2 at $DIR/transmute.rs:+1:39: +1:41
-          _2 = move _3 as Never (Transmute); // scope 2 at $DIR/transmute.rs:+1:29: +1:42
+          StorageLive(_1);                 // scope 0 at $DIR/transmute.rs:+1:9: +1:10
+          StorageLive(_2);                 // scope 2 at $DIR/transmute.rs:+1:39: +1:41
+          _2 = ();                         // scope 2 at $DIR/transmute.rs:+1:39: +1:41
+          _1 = move _2 as Never (Transmute); // scope 2 at $DIR/transmute.rs:+1:29: +1:42
           unreachable;                     // scope 2 at $DIR/transmute.rs:+1:29: +1:42
       }
   }
diff --git a/tests/mir-opt/const_prop/transmute.unreachable_mut.ConstProp.32bit.diff b/tests/mir-opt/const_prop/transmute.unreachable_mut.ConstProp.32bit.diff
index 47f023cd93d..ec8a62bd62c 100644
--- a/tests/mir-opt/const_prop/transmute.unreachable_mut.ConstProp.32bit.diff
+++ b/tests/mir-opt/const_prop/transmute.unreachable_mut.ConstProp.32bit.diff
@@ -3,28 +3,24 @@
   
   fn unreachable_mut() -> ! {
       let mut _0: !;                       // return place in scope 0 at $DIR/transmute.rs:+0:36: +0:37
-      let mut _1: !;                       // in scope 0 at $DIR/transmute.rs:+0:38: +3:2
-      let _2: &mut Never;                  // in scope 0 at $DIR/transmute.rs:+1:9: +1:10
-      let mut _3: &mut Never;              // in scope 0 at $DIR/transmute.rs:+1:34: +1:52
-      let mut _4: !;                       // in scope 0 at $DIR/transmute.rs:+2:5: +2:16
+      let _1: &mut Never;                  // in scope 0 at $DIR/transmute.rs:+1:9: +1:10
+      let mut _2: &mut Never;              // in scope 0 at $DIR/transmute.rs:+1:34: +1:52
       scope 1 {
-          debug x => _2;                   // in scope 1 at $DIR/transmute.rs:+1:9: +1:10
+          debug x => _1;                   // in scope 1 at $DIR/transmute.rs:+1:9: +1:10
       }
       scope 2 {
       }
   
       bb0: {
-          StorageLive(_1);                 // scope 0 at $DIR/transmute.rs:+0:38: +3:2
-          StorageLive(_2);                 // scope 0 at $DIR/transmute.rs:+1:9: +1:10
-          StorageLive(_3);                 // scope 0 at $DIR/transmute.rs:+1:34: +1:52
--         _3 = const 1_usize as &mut Never (Transmute); // scope 2 at $DIR/transmute.rs:+1:34: +1:52
-+         _3 = const {0x1 as &mut Never};  // scope 2 at $DIR/transmute.rs:+1:34: +1:52
+          StorageLive(_1);                 // scope 0 at $DIR/transmute.rs:+1:9: +1:10
+          StorageLive(_2);                 // scope 0 at $DIR/transmute.rs:+1:34: +1:52
+-         _2 = const 1_usize as &mut Never (Transmute); // scope 2 at $DIR/transmute.rs:+1:34: +1:52
++         _2 = const {0x1 as &mut Never};  // scope 2 at $DIR/transmute.rs:+1:34: +1:52
 +                                          // mir::Constant
 +                                          // + span: no-location
 +                                          // + literal: Const { ty: &mut Never, val: Value(Scalar(0x00000001)) }
-          _2 = &mut (*_3);                 // scope 0 at $DIR/transmute.rs:+1:34: +1:52
-          StorageDead(_3);                 // scope 0 at $DIR/transmute.rs:+1:54: +1:55
-          StorageLive(_4);                 // scope 1 at $DIR/transmute.rs:+2:5: +2:16
+          _1 = &mut (*_2);                 // scope 0 at $DIR/transmute.rs:+1:34: +1:52
+          StorageDead(_2);                 // scope 0 at $DIR/transmute.rs:+1:54: +1:55
           unreachable;                     // scope 1 at $DIR/transmute.rs:+2:11: +2:13
       }
   }
diff --git a/tests/mir-opt/const_prop/transmute.unreachable_mut.ConstProp.64bit.diff b/tests/mir-opt/const_prop/transmute.unreachable_mut.ConstProp.64bit.diff
index 62300d2e313..288da6e56c5 100644
--- a/tests/mir-opt/const_prop/transmute.unreachable_mut.ConstProp.64bit.diff
+++ b/tests/mir-opt/const_prop/transmute.unreachable_mut.ConstProp.64bit.diff
@@ -3,28 +3,24 @@
   
   fn unreachable_mut() -> ! {
       let mut _0: !;                       // return place in scope 0 at $DIR/transmute.rs:+0:36: +0:37
-      let mut _1: !;                       // in scope 0 at $DIR/transmute.rs:+0:38: +3:2
-      let _2: &mut Never;                  // in scope 0 at $DIR/transmute.rs:+1:9: +1:10
-      let mut _3: &mut Never;              // in scope 0 at $DIR/transmute.rs:+1:34: +1:52
-      let mut _4: !;                       // in scope 0 at $DIR/transmute.rs:+2:5: +2:16
+      let _1: &mut Never;                  // in scope 0 at $DIR/transmute.rs:+1:9: +1:10
+      let mut _2: &mut Never;              // in scope 0 at $DIR/transmute.rs:+1:34: +1:52
       scope 1 {
-          debug x => _2;                   // in scope 1 at $DIR/transmute.rs:+1:9: +1:10
+          debug x => _1;                   // in scope 1 at $DIR/transmute.rs:+1:9: +1:10
       }
       scope 2 {
       }
   
       bb0: {
-          StorageLive(_1);                 // scope 0 at $DIR/transmute.rs:+0:38: +3:2
-          StorageLive(_2);                 // scope 0 at $DIR/transmute.rs:+1:9: +1:10
-          StorageLive(_3);                 // scope 0 at $DIR/transmute.rs:+1:34: +1:52
--         _3 = const 1_usize as &mut Never (Transmute); // scope 2 at $DIR/transmute.rs:+1:34: +1:52
-+         _3 = const {0x1 as &mut Never};  // scope 2 at $DIR/transmute.rs:+1:34: +1:52
+          StorageLive(_1);                 // scope 0 at $DIR/transmute.rs:+1:9: +1:10
+          StorageLive(_2);                 // scope 0 at $DIR/transmute.rs:+1:34: +1:52
+-         _2 = const 1_usize as &mut Never (Transmute); // scope 2 at $DIR/transmute.rs:+1:34: +1:52
++         _2 = const {0x1 as &mut Never};  // scope 2 at $DIR/transmute.rs:+1:34: +1:52
 +                                          // mir::Constant
 +                                          // + span: no-location
 +                                          // + literal: Const { ty: &mut Never, val: Value(Scalar(0x0000000000000001)) }
-          _2 = &mut (*_3);                 // scope 0 at $DIR/transmute.rs:+1:34: +1:52
-          StorageDead(_3);                 // scope 0 at $DIR/transmute.rs:+1:54: +1:55
-          StorageLive(_4);                 // scope 1 at $DIR/transmute.rs:+2:5: +2:16
+          _1 = &mut (*_2);                 // scope 0 at $DIR/transmute.rs:+1:34: +1:52
+          StorageDead(_2);                 // scope 0 at $DIR/transmute.rs:+1:54: +1:55
           unreachable;                     // scope 1 at $DIR/transmute.rs:+2:11: +2:13
       }
   }
diff --git a/tests/mir-opt/const_prop/transmute.unreachable_ref.ConstProp.32bit.diff b/tests/mir-opt/const_prop/transmute.unreachable_ref.ConstProp.32bit.diff
index 8578f898a7e..dcca0fca619 100644
--- a/tests/mir-opt/const_prop/transmute.unreachable_ref.ConstProp.32bit.diff
+++ b/tests/mir-opt/const_prop/transmute.unreachable_ref.ConstProp.32bit.diff
@@ -3,24 +3,20 @@
   
   fn unreachable_ref() -> ! {
       let mut _0: !;                       // return place in scope 0 at $DIR/transmute.rs:+0:36: +0:37
-      let mut _1: !;                       // in scope 0 at $DIR/transmute.rs:+0:38: +3:2
-      let _2: &Never;                      // in scope 0 at $DIR/transmute.rs:+1:9: +1:10
-      let mut _3: !;                       // in scope 0 at $DIR/transmute.rs:+2:5: +2:16
+      let _1: &Never;                      // in scope 0 at $DIR/transmute.rs:+1:9: +1:10
       scope 1 {
-          debug x => _2;                   // in scope 1 at $DIR/transmute.rs:+1:9: +1:10
+          debug x => _1;                   // in scope 1 at $DIR/transmute.rs:+1:9: +1:10
       }
       scope 2 {
       }
   
       bb0: {
-          StorageLive(_1);                 // scope 0 at $DIR/transmute.rs:+0:38: +3:2
-          StorageLive(_2);                 // scope 0 at $DIR/transmute.rs:+1:9: +1:10
--         _2 = const 1_usize as &Never (Transmute); // scope 2 at $DIR/transmute.rs:+1:30: +1:48
-+         _2 = const {0x1 as &Never};      // scope 2 at $DIR/transmute.rs:+1:30: +1:48
+          StorageLive(_1);                 // scope 0 at $DIR/transmute.rs:+1:9: +1:10
+-         _1 = const 1_usize as &Never (Transmute); // scope 2 at $DIR/transmute.rs:+1:30: +1:48
++         _1 = const {0x1 as &Never};      // scope 2 at $DIR/transmute.rs:+1:30: +1:48
 +                                          // mir::Constant
 +                                          // + span: no-location
 +                                          // + literal: Const { ty: &Never, val: Value(Scalar(0x00000001)) }
-          StorageLive(_3);                 // scope 1 at $DIR/transmute.rs:+2:5: +2:16
           unreachable;                     // scope 1 at $DIR/transmute.rs:+2:11: +2:13
       }
   }
diff --git a/tests/mir-opt/const_prop/transmute.unreachable_ref.ConstProp.64bit.diff b/tests/mir-opt/const_prop/transmute.unreachable_ref.ConstProp.64bit.diff
index 8b11cea9365..3a0b967e66f 100644
--- a/tests/mir-opt/const_prop/transmute.unreachable_ref.ConstProp.64bit.diff
+++ b/tests/mir-opt/const_prop/transmute.unreachable_ref.ConstProp.64bit.diff
@@ -3,24 +3,20 @@
   
   fn unreachable_ref() -> ! {
       let mut _0: !;                       // return place in scope 0 at $DIR/transmute.rs:+0:36: +0:37
-      let mut _1: !;                       // in scope 0 at $DIR/transmute.rs:+0:38: +3:2
-      let _2: &Never;                      // in scope 0 at $DIR/transmute.rs:+1:9: +1:10
-      let mut _3: !;                       // in scope 0 at $DIR/transmute.rs:+2:5: +2:16
+      let _1: &Never;                      // in scope 0 at $DIR/transmute.rs:+1:9: +1:10
       scope 1 {
-          debug x => _2;                   // in scope 1 at $DIR/transmute.rs:+1:9: +1:10
+          debug x => _1;                   // in scope 1 at $DIR/transmute.rs:+1:9: +1:10
       }
       scope 2 {
       }
   
       bb0: {
-          StorageLive(_1);                 // scope 0 at $DIR/transmute.rs:+0:38: +3:2
-          StorageLive(_2);                 // scope 0 at $DIR/transmute.rs:+1:9: +1:10
--         _2 = const 1_usize as &Never (Transmute); // scope 2 at $DIR/transmute.rs:+1:30: +1:48
-+         _2 = const {0x1 as &Never};      // scope 2 at $DIR/transmute.rs:+1:30: +1:48
+          StorageLive(_1);                 // scope 0 at $DIR/transmute.rs:+1:9: +1:10
+-         _1 = const 1_usize as &Never (Transmute); // scope 2 at $DIR/transmute.rs:+1:30: +1:48
++         _1 = const {0x1 as &Never};      // scope 2 at $DIR/transmute.rs:+1:30: +1:48
 +                                          // mir::Constant
 +                                          // + span: no-location
 +                                          // + literal: Const { ty: &Never, val: Value(Scalar(0x0000000000000001)) }
-          StorageLive(_3);                 // scope 1 at $DIR/transmute.rs:+2:5: +2:16
           unreachable;                     // scope 1 at $DIR/transmute.rs:+2:11: +2:13
       }
   }
diff --git a/tests/mir-opt/issue_72181_1.f.built.after.mir b/tests/mir-opt/issue_72181_1.f.built.after.mir
index 4086da52011..25f47225113 100644
--- a/tests/mir-opt/issue_72181_1.f.built.after.mir
+++ b/tests/mir-opt/issue_72181_1.f.built.after.mir
@@ -3,27 +3,13 @@
 fn f(_1: Void) -> ! {
     debug v => _1;                       // in scope 0 at $DIR/issue_72181_1.rs:+0:6: +0:7
     let mut _0: !;                       // return place in scope 0 at $DIR/issue_72181_1.rs:+0:18: +0:19
-    let mut _2: !;                       // in scope 0 at $DIR/issue_72181_1.rs:+0:20: +2:2
-    let mut _3: !;                       // in scope 0 at $DIR/issue_72181_1.rs:+1:5: +1:15
 
     bb0: {
-        StorageLive(_2);                 // scope 0 at $DIR/issue_72181_1.rs:+0:20: +2:2
-        StorageLive(_3);                 // scope 0 at $DIR/issue_72181_1.rs:+1:5: +1:15
         FakeRead(ForMatchedPlace(None), _1); // scope 0 at $DIR/issue_72181_1.rs:+1:11: +1:12
         unreachable;                     // scope 0 at $DIR/issue_72181_1.rs:+1:11: +1:12
     }
 
     bb1: {
-        unreachable;                     // scope 0 at $DIR/issue_72181_1.rs:+1:5: +1:15
-    }
-
-    bb2: {
-        StorageDead(_3);                 // scope 0 at $DIR/issue_72181_1.rs:+1:14: +1:15
-        unreachable;                     // scope 0 at $DIR/issue_72181_1.rs:+0:20: +2:2
-    }
-
-    bb3: {
-        StorageDead(_2);                 // scope 0 at $DIR/issue_72181_1.rs:+2:1: +2:2
         return;                          // scope 0 at $DIR/issue_72181_1.rs:+2:2: +2:2
     }
 }
diff --git a/tests/mir-opt/lower_intrinsics.transmute_to_box_uninhabited.LowerIntrinsics.diff b/tests/mir-opt/lower_intrinsics.transmute_to_box_uninhabited.LowerIntrinsics.diff
index 8735a750060..aa5d9619d10 100644
--- a/tests/mir-opt/lower_intrinsics.transmute_to_box_uninhabited.LowerIntrinsics.diff
+++ b/tests/mir-opt/lower_intrinsics.transmute_to_box_uninhabited.LowerIntrinsics.diff
@@ -3,26 +3,22 @@
   
   fn transmute_to_box_uninhabited() -> ! {
       let mut _0: !;                       // return place in scope 0 at $DIR/lower_intrinsics.rs:+0:49: +0:50
-      let mut _1: !;                       // in scope 0 at $DIR/lower_intrinsics.rs:+0:51: +3:2
-      let _2: std::boxed::Box<Never>;      // in scope 0 at $DIR/lower_intrinsics.rs:+1:9: +1:10
-      let mut _3: !;                       // in scope 0 at $DIR/lower_intrinsics.rs:+2:5: +2:16
+      let _1: std::boxed::Box<Never>;      // in scope 0 at $DIR/lower_intrinsics.rs:+1:9: +1:10
       scope 1 {
-          debug x => _2;                   // in scope 1 at $DIR/lower_intrinsics.rs:+1:9: +1:10
+          debug x => _1;                   // in scope 1 at $DIR/lower_intrinsics.rs:+1:9: +1:10
       }
   
       bb0: {
-          StorageLive(_1);                 // scope 0 at $DIR/lower_intrinsics.rs:+0:51: +3:2
-          StorageLive(_2);                 // scope 0 at $DIR/lower_intrinsics.rs:+1:9: +1:10
--         _2 = transmute::<usize, Box<Never>>(const 1_usize) -> [return: bb1, unwind unreachable]; // scope 0 at $DIR/lower_intrinsics.rs:+1:25: +1:52
+          StorageLive(_1);                 // scope 0 at $DIR/lower_intrinsics.rs:+1:9: +1:10
+-         _1 = transmute::<usize, Box<Never>>(const 1_usize) -> [return: bb1, unwind unreachable]; // scope 0 at $DIR/lower_intrinsics.rs:+1:25: +1:52
 -                                          // mir::Constant
 -                                          // + span: $DIR/lower_intrinsics.rs:70:25: 70:44
 -                                          // + literal: Const { ty: unsafe extern "rust-intrinsic" fn(usize) -> Box<Never> {transmute::<usize, Box<Never>>}, val: Value(<ZST>) }
-+         _2 = const 1_usize as std::boxed::Box<Never> (Transmute); // scope 0 at $DIR/lower_intrinsics.rs:+1:25: +1:52
++         _1 = const 1_usize as std::boxed::Box<Never> (Transmute); // scope 0 at $DIR/lower_intrinsics.rs:+1:25: +1:52
 +         goto -> bb1;                     // scope 0 at $DIR/lower_intrinsics.rs:+1:25: +1:52
       }
   
       bb1: {
-          StorageLive(_3);                 // scope 1 at $DIR/lower_intrinsics.rs:+2:5: +2:16
           unreachable;                     // scope 1 at $DIR/lower_intrinsics.rs:+2:11: +2:13
       }
   }
diff --git a/tests/mir-opt/lower_intrinsics.transmute_to_mut_uninhabited.LowerIntrinsics.diff b/tests/mir-opt/lower_intrinsics.transmute_to_mut_uninhabited.LowerIntrinsics.diff
index a772132770c..5fafd45fe85 100644
--- a/tests/mir-opt/lower_intrinsics.transmute_to_mut_uninhabited.LowerIntrinsics.diff
+++ b/tests/mir-opt/lower_intrinsics.transmute_to_mut_uninhabited.LowerIntrinsics.diff
@@ -3,26 +3,22 @@
   
   fn transmute_to_mut_uninhabited() -> ! {
       let mut _0: !;                       // return place in scope 0 at $DIR/lower_intrinsics.rs:+0:49: +0:50
-      let mut _1: !;                       // in scope 0 at $DIR/lower_intrinsics.rs:+0:51: +3:2
-      let _2: &mut Never;                  // in scope 0 at $DIR/lower_intrinsics.rs:+1:9: +1:10
-      let mut _3: !;                       // in scope 0 at $DIR/lower_intrinsics.rs:+2:5: +2:16
+      let _1: &mut Never;                  // in scope 0 at $DIR/lower_intrinsics.rs:+1:9: +1:10
       scope 1 {
-          debug x => _2;                   // in scope 1 at $DIR/lower_intrinsics.rs:+1:9: +1:10
+          debug x => _1;                   // in scope 1 at $DIR/lower_intrinsics.rs:+1:9: +1:10
       }
   
       bb0: {
-          StorageLive(_1);                 // scope 0 at $DIR/lower_intrinsics.rs:+0:51: +3:2
-          StorageLive(_2);                 // scope 0 at $DIR/lower_intrinsics.rs:+1:9: +1:10
--         _2 = transmute::<usize, &mut Never>(const 1_usize) -> [return: bb1, unwind unreachable]; // scope 0 at $DIR/lower_intrinsics.rs:+1:25: +1:52
+          StorageLive(_1);                 // scope 0 at $DIR/lower_intrinsics.rs:+1:9: +1:10
+-         _1 = transmute::<usize, &mut Never>(const 1_usize) -> [return: bb1, unwind unreachable]; // scope 0 at $DIR/lower_intrinsics.rs:+1:25: +1:52
 -                                          // mir::Constant
 -                                          // + span: $DIR/lower_intrinsics.rs:64:25: 64:44
 -                                          // + literal: Const { ty: unsafe extern "rust-intrinsic" fn(usize) -> &mut Never {transmute::<usize, &mut Never>}, val: Value(<ZST>) }
-+         _2 = const 1_usize as &mut Never (Transmute); // scope 0 at $DIR/lower_intrinsics.rs:+1:25: +1:52
++         _1 = const 1_usize as &mut Never (Transmute); // scope 0 at $DIR/lower_intrinsics.rs:+1:25: +1:52
 +         goto -> bb1;                     // scope 0 at $DIR/lower_intrinsics.rs:+1:25: +1:52
       }
   
       bb1: {
-          StorageLive(_3);                 // scope 1 at $DIR/lower_intrinsics.rs:+2:5: +2:16
           unreachable;                     // scope 1 at $DIR/lower_intrinsics.rs:+2:11: +2:13
       }
   }
diff --git a/tests/mir-opt/lower_intrinsics.transmute_to_ref_uninhabited.LowerIntrinsics.diff b/tests/mir-opt/lower_intrinsics.transmute_to_ref_uninhabited.LowerIntrinsics.diff
index c4d53d4e8c7..08dead13211 100644
--- a/tests/mir-opt/lower_intrinsics.transmute_to_ref_uninhabited.LowerIntrinsics.diff
+++ b/tests/mir-opt/lower_intrinsics.transmute_to_ref_uninhabited.LowerIntrinsics.diff
@@ -3,26 +3,22 @@
   
   fn transmute_to_ref_uninhabited() -> ! {
       let mut _0: !;                       // return place in scope 0 at $DIR/lower_intrinsics.rs:+0:49: +0:50
-      let mut _1: !;                       // in scope 0 at $DIR/lower_intrinsics.rs:+0:51: +3:2
-      let _2: &Never;                      // in scope 0 at $DIR/lower_intrinsics.rs:+1:9: +1:10
-      let mut _3: !;                       // in scope 0 at $DIR/lower_intrinsics.rs:+2:5: +2:16
+      let _1: &Never;                      // in scope 0 at $DIR/lower_intrinsics.rs:+1:9: +1:10
       scope 1 {
-          debug x => _2;                   // in scope 1 at $DIR/lower_intrinsics.rs:+1:9: +1:10
+          debug x => _1;                   // in scope 1 at $DIR/lower_intrinsics.rs:+1:9: +1:10
       }
   
       bb0: {
-          StorageLive(_1);                 // scope 0 at $DIR/lower_intrinsics.rs:+0:51: +3:2
-          StorageLive(_2);                 // scope 0 at $DIR/lower_intrinsics.rs:+1:9: +1:10
--         _2 = transmute::<usize, &Never>(const 1_usize) -> [return: bb1, unwind unreachable]; // scope 0 at $DIR/lower_intrinsics.rs:+1:21: +1:48
+          StorageLive(_1);                 // scope 0 at $DIR/lower_intrinsics.rs:+1:9: +1:10
+-         _1 = transmute::<usize, &Never>(const 1_usize) -> [return: bb1, unwind unreachable]; // scope 0 at $DIR/lower_intrinsics.rs:+1:21: +1:48
 -                                          // mir::Constant
 -                                          // + span: $DIR/lower_intrinsics.rs:58:21: 58:40
 -                                          // + literal: Const { ty: unsafe extern "rust-intrinsic" fn(usize) -> &Never {transmute::<usize, &Never>}, val: Value(<ZST>) }
-+         _2 = const 1_usize as &Never (Transmute); // scope 0 at $DIR/lower_intrinsics.rs:+1:21: +1:48
++         _1 = const 1_usize as &Never (Transmute); // scope 0 at $DIR/lower_intrinsics.rs:+1:21: +1:48
 +         goto -> bb1;                     // scope 0 at $DIR/lower_intrinsics.rs:+1:21: +1:48
       }
   
       bb1: {
-          StorageLive(_3);                 // scope 1 at $DIR/lower_intrinsics.rs:+2:5: +2:16
           unreachable;                     // scope 1 at $DIR/lower_intrinsics.rs:+2:11: +2:13
       }
   }
diff --git a/tests/mir-opt/lower_intrinsics.unreachable.LowerIntrinsics.diff b/tests/mir-opt/lower_intrinsics.unreachable.LowerIntrinsics.diff
index c0cc698c481..28e45909c33 100644
--- a/tests/mir-opt/lower_intrinsics.unreachable.LowerIntrinsics.diff
+++ b/tests/mir-opt/lower_intrinsics.unreachable.LowerIntrinsics.diff
@@ -3,16 +3,15 @@
   
   fn unreachable() -> ! {
       let mut _0: !;                       // return place in scope 0 at $DIR/lower_intrinsics.rs:+0:25: +0:26
-      let mut _1: !;                       // in scope 0 at $DIR/lower_intrinsics.rs:+0:27: +2:2
-      let _2: ();                          // in scope 0 at $DIR/lower_intrinsics.rs:+1:14: +1:45
-      let mut _3: !;                       // in scope 0 at $DIR/lower_intrinsics.rs:+1:14: +1:45
+      let _1: ();                          // in scope 0 at $DIR/lower_intrinsics.rs:+1:14: +1:45
+      let mut _2: !;                       // in scope 0 at $DIR/lower_intrinsics.rs:+1:14: +1:45
       scope 1 {
       }
   
       bb0: {
-          StorageLive(_2);                 // scope 0 at $DIR/lower_intrinsics.rs:+1:5: +1:47
-          StorageLive(_3);                 // scope 1 at $DIR/lower_intrinsics.rs:+1:14: +1:45
--         _3 = std::intrinsics::unreachable() -> unwind unreachable; // scope 1 at $DIR/lower_intrinsics.rs:+1:14: +1:45
+          StorageLive(_1);                 // scope 0 at $DIR/lower_intrinsics.rs:+1:5: +1:47
+          StorageLive(_2);                 // scope 1 at $DIR/lower_intrinsics.rs:+1:14: +1:45
+-         _2 = std::intrinsics::unreachable() -> unwind unreachable; // scope 1 at $DIR/lower_intrinsics.rs:+1:14: +1:45
 -                                          // mir::Constant
 -                                          // + span: $DIR/lower_intrinsics.rs:31:14: 31:43
 -                                          // + literal: Const { ty: unsafe extern "rust-intrinsic" fn() -> ! {std::intrinsics::unreachable}, val: Value(<ZST>) }