minwin-gcc-5-2/libjava/sysdep/pa/descriptor-pa64-hpux.h

// Given a function pointer, return the code address.
// If the plabel bit is set, mask it off and return the code from the
// first word of the function descriptor.  Otherwise, the function
// pointer is the code address.

#define UNWRAP_FUNCTION_DESCRIPTOR(X) *(void **)((unsigned long) (X) + 16)