Message-ID: <37B57FBB.710B3456@unb.ca>
From: Endlisnis <s257m AT unb DOT ca>
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Newsgroups: comp.os.msdos.djgpp
Subject: Re: Bit counting?
References: <37B45836 DOT EAD7C82D AT swipnet DOT se> <37B48ABE DOT 110D2C13 AT intel DOT com> <37B4D8BC DOT 6465 AT ns DOT sympatico DOT ca>
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Date: Sat, 14 Aug 1999 14:41:01 GMT
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To: djgpp AT delorie DOT com
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Reply-To: djgpp AT delorie DOT com

Klaas wrote:

> > int
> > Ones(unsigned long mask)
> > {
> >   register unsigned long y;
> >
> >   y = (mask >> 1) & 033333333333;
> >   y = mask - y - ((y >>1) & 033333333333);
> >   return (int) (((y + (y >> 3)) & 030707070707) % 077);
> > }
> >
> > Regards,
> > Kurt Alstrup
> Doesn't the modulo make it rather slow?

    Hopefully, the compiler would replace that with "& ~077", but it probably
should be changed to that just in case...


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