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Message-ID: <mpro.mayz3x0al1ulc02iz.taviso@cmpxchg8b.com>
Date: Wed, 26 Sep 2012 20:23:57 +0200
From: Tavis Ormandy <taviso@...xchg8b.com>
To: john-dev@...ts.openwall.com
Subject: Re: choosing code optimisations

magnum <john.magnum@...hmail.com> wrote:

> On 26 Sep, 2012, at 13:45 , Tavis Ormandy
> <taviso@...xchg8b.com> wrote:
> 
> > Hey, just in case anybody else wants to try it with their formats, here
> > is a quick note on finding low hanging performance wins for gcc. I've
> > been using the attached script to benchmark different options, it turns
> > out
> ...
> 
> That's curious. I'll play a little with it. How many of those are there?
> Ideally I guess you'd want to test combinations of two or more of these
> too, but that might end up in a truckload of combinations.

Quite a few, and there are also some non-optimiser options that can be quite
beneficial, like -minline-all-stringops (seems like a minor win for
raw-sha1-ng, but maybe not worth a patch).

> 
> > $ ../run/john --test --format=nt Benchmarking: NT MD4 [128/128 X2
> > SSE2-16]... DONE Raw:    37253K c/s real, 37253K c/s virtual
> > 
> > $ bash ~/chooseopts.sh linux-x86-64-native nt2_fmt_plug.c nt | sort -g |
> > tail
> 
> Not sure if that was just some kind of cosmetic error in your mail but
> just FYI, NT (source file NT_fmt_plug.c) is one thing, and nt2 (source
> file nt2_fmt_plug.c) are completely different implementations of the same
> format. With today's naming the latter would be called nt-ng I suppose.
> 

Oops, yes, I was typing from memory.

Tavis.


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