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Re: Question on hwcaps

From: "Carlos O'Donell" <carlos at systemhalted dot org>
To: Narayan Subramanian <nsubrama at gmail dot com>
Cc: libc-help at sourceware dot org
Date: Wed, 1 Apr 2009 22:58:31 -0400
Subject: Re: Question on hwcaps
References: <8f9209c60904011115h2c4eecf8vfb37488cf182ba58@mail.gmail.com>

On Wed, Apr 1, 2009 at 2:15 PM, Narayan Subramanian <nsubrama@gmail.com> wrote:
> On my debian 5.0 system using glibc-2.7, the set of important hwcaps
> identified by the system (apart from "tls" and i686) are sse2 and cmov
> respectively. I can see this with LD_DEBUG=all.
>
> However by examining the source code for glibc-2.7, the only default
> hwcaps mask should be sse2. So from where did the cmov mask come from?
>
> Any insight into this would be very helpful.

The linux kernel passes it to userspace via AT_HWCAP (see fs/binfmt_elf.c).

Cheers,
Carlos.

References:
- Question on hwcaps
  - From: Narayan Subramanian

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