| From: | Rudi Chiarito |
| Date: | 22 Aug 2000 at 15:49:32 |
| Subject: | Re: AMIOPEN: Retooling existing applications |
On Mon, Aug 21, 2000 at 04:04:38PM -0700, Jesse McClusky wrote:
> > Also the Quick Reference Guide (P32) says "Do not .. modify special
> > registers."
> It does say it's possible to do though.
The VP Reference Manual also says (in 2.2.4, emphasis is mine): "The gp
pointer points to a *kernel maintained* block of data global to the
thread [...] The global pointer *should not be altered by the application
programmer*."
In other words: don't touch it, or you will get in big trouble with the
kernel. And you DON'T want to be enemies with the kernel... *wink*
> From a bit of testing, it appears you're pretty much in the clear if you
> save the former value first, and restore it again *before* returning *or*
> making any calls. That doesn't, however, mean this will still be true in
> future revisions, so I highly advise against it unless you're doing
It's a good thing that in the end you do not recommend it. ;)