ignore arrays in operands

Author: tesuji

compiler/rustc_mir_transform/src/gvn.rs

@@ -816,6 +816,10 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
             }
             Operand::Copy(ref mut place) | Operand::Move(ref mut place) => {
                 let value = self.simplify_place_value(place, location)?;
+                // Ignore arrays in operand.
+                if let Value::Aggregate(AggregateTy::Array, ..) = self.get(value) {
+                    return None;
+                }
                 if let Some(const_) = self.try_as_constant(value) {
                     *operand = Operand::Constant(Box::new(const_));
                 }

tests/mir-opt/const_array_locals.main.GVN.diff

@@ -74,9 +74,8 @@
           StorageLive(_11);
           StorageLive(_12);
 -         _12 = [const 1f32, const 2f32, const 3f32, const 1f32, const 1f32, const 1f32, const 1f32, const 42f32];
--         _11 = F32x8(move _12);
 +         _12 = const [1f32, 2f32, 3f32, 1f32, 1f32, 1f32, 1f32, 42f32];
-+         _11 = F32x8(const [1f32, 2f32, 3f32, 1f32, 1f32, 1f32, 1f32, 42f32]);
+          _11 = F32x8(move _12);
           StorageDead(_12);
           StorageLive(_13);
           StorageLive(_14);