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Message-ID: <4FB940F8.8060102@gmail.com>
Date: Sun, 20 May 2012 16:07:36 -0300
From: Claudio André <claudioandre.br@...il.com>
To: john-dev@...ts.openwall.com
Subject: Re: OpenCL SWAP64 on 7970
Em 05-05-2012 22:55, myrice escreveu:
> Claudio, all
>
> It seems that 7970 has some strange behaviors when we perform bitwise
> operation with ulong type. SWAP64 didn't work correctly.
> xsha512-opencl and cryptsha512-opencl are all influenced. Here is what
> I get from my debugging.
>
> With a 64bit variable n, if we do (n)<< 56, no problem. However, if
> we do (n)& 0xff00<< 24 or<< 32 or<< 40, the result will be 0. It
> seems that the& operation converts the result to a 32bit variable. So
> the<< 24 or above will make the result to be 0.
>
> Thanks
> myrice
Sorry for the late answer, in 7970 you can't use the regular bitwise
operations on SWAP64. Another crazy bug??
You got good answers already about vector usage (#define SWAP64(n)
(as_ulong(as_uchar8(n).s76543210)))
For NVIDIA and CPU keep your bitwise SWAP64 version (for better
performance).
Claudio
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