What is a pragma

Answer:# pragma preprocessor directive is use to allow the compiler to do the some specific operation of compiler.pragma has on and off command using them we can enable or disable some compiler operations.
Suppose, In our program loop does not perform his operation may be it happen because of pragma.
1.If we want to enable the operation of loop using pragma. Than we have to write like that,
#pragma loop_opt(on)

2.If we want to disable the operation of loop using pragma. Than we have to write like that,
#pragma loop_opt(off)