Also turn moves into copies even if through projections.

Author: cjgillot

compiler/rustc_mir_transform/src/gvn.rs

@@ -1228,8 +1228,8 @@ impl<'tcx> MutVisitor<'tcx> for StorageRemover<'tcx> {
 
     fn visit_operand(&mut self, operand: &mut Operand<'tcx>, _: Location) {
         if let Operand::Move(place) = *operand
-            && let Some(local) = place.as_local()
-            && self.reused_locals.contains(local)
+            && !place.is_indirect_first_projection()
+            && self.reused_locals.contains(place.local)
         {
             *operand = Operand::Copy(place);
         }

tests/mir-opt/gvn_copy_moves.fn0.GVN.diff

@@ -17,7 +17,7 @@
           _3 = (_2,);
           _4 = _3;
 -         _5 = fn1(move (_3.0: [u128; 6]), _4) -> [return: bb1, unwind unreachable];
-+         _5 = fn1(move (_3.0: [u128; 6]), _3) -> [return: bb1, unwind unreachable];
++         _5 = fn1((_3.0: [u128; 6]), _3) -> [return: bb1, unwind unreachable];
       }
 
       bb1: {

tests/mir-opt/separate_const_switch.identity.SeparateConstSwitch.diff

@@ -66,7 +66,7 @@
           _5 = ((_2 as Break).0: std::result::Result<std::convert::Infallible, i32>);
           StorageLive(_6);
           _6 = _5;
-          _12 = move ((_5 as Err).0: i32);
+          _12 = ((_5 as Err).0: i32);
           _0 = Result::<i32, i32>::Err(_12);
           StorageDead(_6);
           StorageDead(_2);
@@ -83,7 +83,7 @@
       }
 
       bb4: {
-          _10 = move ((_1 as Err).0: i32);
+          _10 = ((_1 as Err).0: i32);
           StorageLive(_11);
           _11 = Result::<Infallible, i32>::Err(_10);
           _2 = ControlFlow::<Result<Infallible, i32>, i32>::Break(move _11);
@@ -92,7 +92,7 @@
       }
 
       bb5: {
-          _9 = move ((_1 as Ok).0: i32);
+          _9 = ((_1 as Ok).0: i32);
           _2 = ControlFlow::<Result<Infallible, i32>, i32>::Continue(_9);
           goto -> bb3;
       }