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Date: Sun, 6 May 2012 09:55:31 +0800
From: myrice <>
Subject: OpenCL SWAP64 on 7970

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.


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