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Date: Sun, 17 Jun 2012 22:14:27 +0400
From: Solar Designer <solar@...nwall.com>
To: john-dev@...ts.openwall.com
Subject: Re: [patch] optional new raw sha1 implemetation

On Sun, Jun 17, 2012 at 06:54:44PM +0200, magnum wrote:
> On 2012-06-17 17:51, Solar Designer wrote:
> >On Sun, Jun 17, 2012 at 05:38:01PM +0200, magnum wrote:
> >>I built with the -native target so I should have got the same speed as
> >>you for Simon's format. But 22600K is the best I get from the
> >>fluctuations. Any idea why?
> >
> >No.
> >
> >>Is an -xop build different in some way?
> >
> >It should be the same, but you could want to check the binary.
> 
> I checked the code and the behavior of gcc and from what I can see there 
> should be absolutely no difference with the #ifdefs so this must be 
> something with the gcc optimizer. But we do get a different 
> taviso_fmt.o. Maybe I'll dissect them some rainy day.

Oh, I totally forgot that -march=native enables not only the instruction
set, but also tuning for the specific CPU.  Of course, the resulting
code should be different.  Apparently, gcc's tuning for Bulldozer
actually hurts in this case.

Alexander

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