fix dist slice op (#47980)

python/paddle/distributed/auto_parallel/operators/dist_slice.py

@@ -40,8 +40,8 @@ class DistributedSliceImpl(DistributedOperatorImpl):
         op_dist_attr = dist_op.dist_attr
         in_name = op_desc.input('Input')[0]
         out_name = op_desc.output('Out')[0]
-        in_var = dist_op.serial_op.block.var(in_name)
-        out_var = dist_op.serial_op.block.var(out_name)
+        in_var = dist_op.serial_op.block._var_recursive(in_name)
+        out_var = dist_op.serial_op.block._var_recursive(out_name)
         axes = op_desc.attr('axes')
         in_dims_mapping = op_dist_attr.get_input_dims_mapping(in_name)
         for axis in axes:
@@ -57,8 +57,8 @@ class DistributedSliceImpl(DistributedOperatorImpl):
         op_dist_attr = dist_op.dist_attr
         in_name = op_desc.input('Input')[0]
         out_name = op_desc.output('Out')[0]
-        in_var = dist_op.serial_op.block.var(in_name)
-        out_var = dist_op.serial_op.block.var(out_name)
+        in_var = dist_op.serial_op.block._var_recursive(in_name)
+        out_var = dist_op.serial_op.block._var_recursive(out_name)
         axes = op_desc.attr('axes')
         decrease_axis = op_desc.attr('decrease_axis')
         in_dims_mapping = op_dist_attr.get_input_dims_mapping(in_name)