#pragma does_not_write_global_data (funcname [, funcname])
This pragma asserts that the specified list of routines do not write global data directly or indirectly. This allows for better optimization of code around calls to such routines. In particular, assignment statements or stores could be moved around such calls.
The specified functions must be declared with a prototype or empty parameter list prior to this pragma. If the assertion about global access is not true, then the behavior of the program is undefined.