[FFmpeg-devel] [PATCH] Yet more ALAC cleanup (#define removal)

Michael Niedermayer michaelni
Wed Aug 15 22:31:25 CEST 2007


Hi

On Wed, Aug 15, 2007 at 08:50:05PM +0200, Vitor Sessak wrote:
> Hi
>
> Reimar D?ffinger wrote:
>> Hello,
>> On Wed, Aug 15, 2007 at 08:22:59PM +0200, Vitor Sessak wrote:
>>> -#define SIGN_ONLY(v) \
>>> -                     ((v < 0) ? (-1) : \
>>> -                                ((v > 0) ? (1) : \
>>> -                                           (0)))
>>> +static inline int sign_only(int v)
>>> +{
>>> +    if (v < 0)
>>> +        return -1;
>>> +    else if (v > 0)
>>> +        return 1;
>>> +    else
>>> +        return 0;
>>> +}
>> Since you change it anyway, I'd suggest
>> if (v == 0) return 0;
>> return FFSIGN(v);
>> Though benchmarking it might be a good idea unless it is really
>> uncritical.
>> Greetings,
>> Reimar D?ffinger
>
> Nice suggestion, but I don't think it is worth benchmarking. Unless the 
> compiler is very stupid, 

anyone did a IQ test with gcc lately?

anyway, if you benchmark it, also try
(v>>31)-((-v)>>31)

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Complexity theory is the science of finding the exact solution to an
approximation. Benchmarking OTOH is finding an approximation of the exact
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