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Date: Fri, 1 Mar 2013 10:25:35 +0100
From: magnum <john.magnum@...hmail.com>
To: john-dev@...ts.openwall.com
Subject: Re: sizeof(unsigned long)

On 1 Mar, 2013, at 4:03 , Claudio André <claudioandre.br@...il.com> wrote:

> Em 28-02-2013 23:37, magnum escreveu:
>> Claudio,
>> 
>> In both opencl_sha256.h and opencl_sha512.h, you define uint64_t like this:
>> 
>> #define uint64_t unsigned long  //Tip: unsigned long long int failed on compile (AMD).
>> 
>> Unsigned long will fail on most 32-bit builds and even some 64-bit ones, because it will be just 32-bits. If you need a workaround, this is not sufficient. OTOH if uint32_t is enough, you should obviously use that instead.
>> 
>> Apparently some people are very fond of 32-bit builds so this must be fixed. Are you sure using long longs caused failures? Sounds weird to me.
> Well (it should be C99 compliant):
> Build log: "/tmp/OCLhwRn1e.cl", line 37: error: the type "long long" is nonstandard
> 
> I care about it only inside OpenCL code. I will try to think about it further.
> 
> Claudio
> 

Apparently long long is 128-bit in OpenCL, and long is always 64-bit. I did not know this, I just saw it in the reference. So on GPU side you should keep it as unsigned long but on CPU side it should better be ARCH_WORD_64 (or better, include "stdint.h" for a proper definition of uint64_t)

magnum

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