From: "Campbell, Rolf [SKY:1U32:EXCH]" <cp1v45 AT americasm01 DOT nt DOT com>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Bit counting?
Date: Fri, 13 Aug 1999 14:50:28 -0400
Organization: Nortel Networks
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Anders David Skarin wrote:

> Hi,
>
> What is the fastest way (or just a damn fast way) to
> count the nr of binary 1's in a byte/word/dword ?
>
> Is there any assembler instruction for this ?
> (there should be, considering the nr of instructions
> in the sisc processors)

    There are instructions for bsf (bit scan forward), but I don't think
for bitcount.

    Here some good C code for it. [Untested!]

int count=0;
int data=whatever;

while(data&=(data-1)) count++;


-
     -Rolf Campbell (39)3-6318