Re: V2 [PATCH] x86: Add <sys/platform/x86.h>

[Florian Weimer <fweimer at redhat dot com>]

On 08/29/2018 04:38 PM, H.J. Lu wrote:
> On Mon, Aug 20, 2018 at 1:54 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> > On Mon, Aug 6, 2018 at 2:10 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> > > Add <sys/platform/x86.h> to provide an API to access x86 specific platform
> > > features:
> >
> > Here is the updated patch to rename x86  specific functions to x86_XXX.
>
> If there are no comments nor objections:
>
> https://sourceware.org/ml/libc-alpha/2018-08/msg00435.html
>
> I will check it in this Friday,

I'm still concerned that the intended use of this facility is 
incompatible with BIND_NOW and other things that disable lazy binding.

The manual also needs to explain how to use these facilities for feature 
detection.  I assume that just looking at (for example) HAS_CPU_FEATURE 
(AVX512F) will give wrong results.  If this is true, this seriously 
questions why we should expose these tests in a public header file.

Thanks,
Florian