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solved: {un}likely macros?

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On Thursday 01 July 2004 09:35, Borislav Petkov wrote:
> Hi there people,
> first of all i would like to thank everybody for their help in figuring out
> the yesterday's asm oneliner. I have another q, though :)
> The kernel extensively uses these macros.
<snip>

Forget it, i found it in the gcc manual. It uses a builtin function in gcc to 
do better branch prediction, so when we do likely(x), we actually do 
__builtin_expect(!!(x),1) which means that it is likely that x is true, i.e., 
x == 1 and the code after it is (more :)) likely to get executed so that the 
branch prediction algorithm in the processor runs faster.

However, what's with the double negation of x - !!(x)?

Regards,
Boris.
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