Subject: Re: AltiVec and *jmp.
To: Jason R Thorpe <firstname.lastname@example.org>
From: Matt Thomas <email@example.com>
Date: 07/02/2002 08:06:46
At 08:01 AM 7/2/2002, Jason R Thorpe wrote:
>On Tue, Jul 02, 2002 at 12:44:47AM -0700, Matt Thomas wrote:
> > When AltiVec is present (__VEC__ is defined), the jmp_buf is
> > extended by 48 bytes and vector registers are saved starting
> > at offset 256 and the contents of VRSAVE are at offset 248.
> > This requires a different setjmp/longjmp, etal so perform the
> > optional altivec instructions.
>Actually, I'd say that you simply should not do this at all. These
>routines don't save/restore FP state either, for example.
Except that the SVR4 ABI extentions for AltiVec mandate saving the
caller-saved AltiVec registers. The question comes down to whether
we want to ABI-compliant.
Matt Thomas Internet: firstname.lastname@example.org
3am Software Foundry WWW URL: http://www.3am-software.com/bio/matt/
Cupertino, CA Disclaimer: I avow all knowledge of this message