An inline function is expanded in any context in which it is called. This avoids the normal performance overhead associated with the branching for a function call, and it allows functions to be included in basic blocks. The XL C/C++ and Fortran compilers provide several options for inlining.
The following options instruct the compiler to automatically inline all functions it deems appropriate:
The following options allow you to select or name functions to be inlined:
In C/C++, you can also use the standard inline function specifier or the __attribute__(always_inline) extension in your code to mark a function for inlining.
For more information about the various compiler options for controlling function inlining, see the XL Fortran Optimization and Programming and XL C/C++ Programming Guide. For information on the different variations of the inline keyword supported by XL C/ C++, as well as the inlining function attribute extensions, see the XL C/C++ Language Reference .