Re: [Libunwind-devel] libunwind x86-64 optimisations?

[Richard Henderson]

On 07/06/2009 09:34 AM, Lassi Tuura wrote:
> Hey,
>
> > This could also be a dynamic stack realignment (for support of
> > vectorization). I didn't think x86-64 needed that, though.
>
> Basically I guess I worry about use of DW_CFA_def_cfa_expression. From
> what I can tell it's little used on x86-64 (linux) except for syscall
> page and a few glibc exceptions.
>
> Does anyone know any real-life uses of these?

There will be some with i686 and use of SSE arguments in parameters;
on x86-64 and use of AVX arguments in parameters.

Since AVX hardware isn't released yet, you'll not yet see any real-life
uses on x86-64, but it's coming.


r~