If you enclose in parentheses the argument you pass from a PL/I routine to a C routine, the argument is passed by value. C should receive the parameter as the equivalent C type. The XL C compiler generates the appropriate addressing code required to access the parameter values.

You can write your PL/I-callable function as if it were in a C-only environment; you can move it to a C-only environment by removing the #pragma directive.