Why is the state of action subsystem checked in generated code

Hello,

I just worte a matlab level-2 function and created a simple simulink model, refer the figures.

The code generator creates the following code:

The "if statements" at line 43 and 47 are absolutely unnecessary. They just compares the logic state differen between the current and previous function call.

I am sure there is something wrong configed within my matlab level-2 function. But I don't know what.

please help me to eliminate the unnecessary code lines