Difference between g_register and register?

Neither am I, but until it gets out of the pretend world of a simulator and whatever compiler is being used (if it isn't the Arduino IDE), I think it's out of scope for this forum.

I am making a counter to count the amount of cable production...
the counter display is 3 lines of 7segment...each lines contain 4 7seg,means maximum to 9999...

It's not like it would need a lot of hardware to try it out.