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

Florian Weimer fweimer@redhat.com
Wed Aug 29 15:41:00 GMT 2018


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



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