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SubjectRe: Use of C99 int types
Stephen Rothwell wrote:

>On Sun, 03 Apr 2005 13:55:39 +0200 Dag Arne Osvik <da@osvik.no> wrote:
>
>
>>I've been working on a new DES implementation for Linux, and ran into
>>the problem of how to get access to C99 types like uint_fast32_t for
>>internal (not interface) use. In my tests, key setup on Athlon 64 slows
>>down by 40% when using u32 instead of uint_fast32_t.
>>
>>
>
>If you look in stdint.h you may find that uint_fast32_t is actually
>64 bits on Athlon 64 ... so does it help if you use u64?
>
>
>

Yes, but wouldn't it be much better to avoid code like the following,
which may also be wrong (in terms of speed)?

#ifdef CONFIG_64BIT // or maybe CONFIG_X86_64?
#define fast_u32 u64
#else
#define fast_u32 u32
#endif

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