From: "H. Peter Anvin" <hpa@zytor.com>
To: for.poige+linux@gmail.com
Cc: linux-raid@vger.kernel.org
Subject: Re: raid6's using not the best bandwidth method && raid6 algo is significantly slower in x86_64.
Date: Fri, 21 Nov 2008 12:15:10 -0800 [thread overview]
Message-ID: <492716CE.8040900@zytor.com> (raw)
In-Reply-To: <43d009740811211133p7321bc39q1a1eccd9c53d6ca0@mail.gmail.com>
Igor Podlesny wrote:
> 2008/11/22 H. Peter Anvin <hpa@zytor.com>:
> [...]
>> It sort of makes sense that -Os would break this stuff. For newer gccs,
>> it would be better to use SSE2 intrinsics rather than inline assembly.
>> The problem is that it breaks older gcc.
>>
> Well, #ifdef could be helpful then, couldn't it? :-)
>
Yes, and that's probably the way to go.
I just tested a version using gcc intrinsics with gcc 4.3, and it is
almost 20% faster than the inline assembly version. That, plus the fact
that the code is actually readable, makes me really want to figure out
how best to deploy this.
-hpa
next prev parent reply other threads:[~2008-11-21 20:15 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-17 22:35 raid6's using not the best bandwidth method && raid6 algo is significantly slower in x86_64 H. Peter Anvin
2008-11-18 12:03 ` Igor Podlesny
2008-11-18 15:47 ` H. Peter Anvin
2008-11-21 19:22 ` Igor Podlesny
2008-11-21 19:31 ` H. Peter Anvin
2008-11-21 19:33 ` Igor Podlesny
2008-11-21 20:15 ` H. Peter Anvin [this message]
2008-11-22 5:40 ` Igor Podlesny
2008-11-22 5:42 ` H. Peter Anvin
2008-11-22 5:45 ` Igor Podlesny
2008-11-23 1:12 ` John Robinson
2008-12-05 13:36 ` Igor Podlesny
2008-12-05 17:34 ` H. Peter Anvin
-- strict thread matches above, loose matches on Subject: below --
2008-11-16 16:18 Igor Podlesny
2008-11-17 0:36 ` H. Peter Anvin
2008-11-17 20:56 ` Igor Podlesny
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