Bad code for ia64 with function pointer

[Neil Booth]

Jim Wilson wrote:-

> On IA-64, and some other targets, function pointers are represented
> differently than pointers to objects.  On IA-64, a function pointer is a double
> word descriptor that holds the function address and the function GP value.
> Thus you can't get a valid function pointer by casting a char * pointer to a
> function pointer type.

Hi Jim,

What is GP?  I see it written everywhere, but only as "GP".

Neil.