in my lcd program im not using infinity loop still data on lcd is repeating im writing program in c using c8051f120
"[...] im not using infinity loop [...]"
This is embedded development.
Your application should contain an infinite loop. What do you think your application will do if you continue past the end brace of main()? There is no magic operating system that will end the application and start waiting for a new application to be started.
The compiler wendor are free to decide if they should add an infinite loop of their own, or if they should reset the processor and try to reach main() again or possibly invent some other magic action.
It is your job to make sure that you do not need to know what decision the compiler vendor has taken.