john-users - Re: DES with OpenMP

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Date: Fri, 3 Feb 2012 23:59:29 +0400
From: Solar Designer <solar@...nwall.com>
To: john-users@...ts.openwall.com
Subject: Re: DES with OpenMP

On Fri, Feb 03, 2012 at 03:33:28PM +0000, Alex Sicamiotis wrote:
> > An easy thing to check is "size DES_bs_b.o".
> 
> Given my lack of ability to discern asm differences, I just
> did the easy thing, heh. I checked the sizes out of curiosity for GCC
> 4.6.2 and ICC 12.1 (.o files from plain compilation and -fopenmp
> copilation) ... there were huge differences in size (over than 10X)
> which is counter-intuitive relative to the 32kb of a l1 cache. Then I
> tried with GCC 4.3.2 which was fast in the non-omp version. Indeed
> this had differences too. Anyway I gathered most* benchmarks + file
> sizes in one spreadsheet:
> http://imageshack.us/f/217/resultsarein2.png/

I was literally referring to the output of command:

size DES_bs_b.o

Specifically, the number it reports for the .text section.  It should be
around 30 KB, but will vary slightly between the builds.

File sizes do not matter - they mostly reflect debugging info and the
like, which does not affect performance.

I'm sorry that I did not state this more clearly.

Alexander