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Subject: Re: BitScan with reset - not so impressive with 3DNow!

Author: Dieter Buerssner

Date: 15:06:30 12/06/02

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>My point is that the particular trick "b & -b" is portable for signed types but
>the problems can come later (or before!). I am assuming that we are talking
>about signed and unsigned int. Please correct me if I am wrong.

Standard C does not enforce two complement encoding of signed integer types (it
does enforce "this" for unsigned type). Even then, I think -(INT_MIN) is
undefined behaviour. But I will admit, that I could not find it at the moment in
the Standard text. Perhaps my memory is betraying me ...

Cheers,
Dieter




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