Re: Question on PowerPC setjmp/longjmp ABI

[Geoff Keating <geoffk at geoffk dot org>]

> Date: Sat, 17 Feb 2001 16:09:57 -0500
> From: Daniel Jacobowitz <dmj+@andrew.cmu.edu>
> Cc: libc-alpha@sourceware.cygnus.com

> > What do you plan to do to have glibc still work on systems where
> > there's no altivec support?
> 
> Require a glibc to only be configured with altivec support on systems
> where it exists.  This isn't optimal, of course; in my hat as a Debian
> developer, I loathe it.  We can work something out, though, once the
> ABI change has been figured out - the Linux kernel emulates user reads
> of the PVR, if I recall correctly, for just this sort of circumstance. 
> We'll have to waste the space in jmp_buf, obviously, but no big deal. 
> We can offer --with-altivec, --without-altivec, --with-altivec=runtime
> or some such; Debian can ship glibc configured --with-altivec=runtime.
> 
> Do you think such a patch would be acceptable?  I can try to work out
> the details of it now, possibly barring the --with-altivec=runtime code.

It seems like a good first step, so yes, I'm happy with it.

(Of course, eventually you'll want to have --with-altivec choose
optimised versions of certain routines, like memcpy()...)

-- 
- Geoffrey Keating <geoffk@geoffk.org>