From: Andreas Krebbel <krebbel@linux.vnet.ibm.com>
To: Richard Henderson <rth@twiddle.net>
Cc: "Ryan S. Arnold" <ryan.arnold@gmail.com>,
libc-alpha@sourceware.org, libc-ports@sourceware.org
Subject: Re: Include hwcap as ifunc argument
Date: Fri, 08 Jun 2012 14:01:00 -0000 [thread overview]
Message-ID: <4FD2056E.3060704@linux.vnet.ibm.com> (raw)
In-Reply-To: <4FCD333E.3090107@twiddle.net>
On 06/05/2012 12:14 AM, Richard Henderson wrote:
> On 06/04/2012 02:21 PM, Ryan S. Arnold wrote:
>> Peter Bergner reminded me today that on PowerPC the IFUNC resolver
>> will most likely/often use the value in AT_PLATFORM rather than
>> AT_HWCAP to determine which optimized function to use. I suppose this
>> would diminish the necessity of passing the hwcap to the ifunc
>> resolver.
>
> It depends on what's being tested, I suppose.
>
> Within glibc itself you've got lots of platform-specific tuning, so
> you may well use AT_PLATFORM more.
>
> Outside glibc, it might just be a test for Altivec or VDX or whatever.
From a S/390 perspective AT_PLATFORM would also be more helpful. We do not add every new
machine feature to the hwcaps vector so it is not possible to deduce the cpu level just
from the hwcaps vector.
I'm working on the S/390 ifunc support and hope to be able to come up with a patch soon.
Bye,
-Andreas-
next prev parent reply other threads:[~2012-06-08 14:01 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <4FBA744A.6000702@twiddle.net>
2012-05-24 14:40 ` [ppc] " Richard Henderson
2012-05-24 14:45 ` Joseph S. Myers
2012-05-24 19:47 ` David Miller
2012-05-25 17:44 ` Richard Henderson
2012-06-04 21:22 ` Ryan S. Arnold
2012-06-04 22:14 ` Richard Henderson
2012-06-08 14:01 ` Andreas Krebbel [this message]
2012-06-08 14:49 ` Richard Henderson
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