1993-02-23 - Re: Trapdoors

Header Data

From: Phiber Optik <phiber@eff.org>
To: honey@citi.umich.edu (peter honeyman)
Message Hash: d2f69ba7618645cf9fadd75e72586a682766659ad9ef48b0a614dc09461500a2
Message ID: <199302230459.AA27220@eff.org>
Reply To: <9302230338.AA00441@toad.com>
UTC Datetime: 1993-02-23 05:00:43 UTC
Raw Date: Mon, 22 Feb 93 21:00:43 PST

Raw message

From: Phiber Optik <phiber@eff.org>
Date: Mon, 22 Feb 93 21:00:43 PST
To: honey@citi.umich.edu (peter honeyman)
Subject: Re: Trapdoors
In-Reply-To: <9302230338.AA00441@toad.com>
Message-ID: <199302230459.AA27220@eff.org>
MIME-Version: 1.0
Content-Type: text/plain


> 
> > Interestingly enough, there seems to be no such instruction in the
> > VAX ...
> 
> but i believe the vax has ffs (find first set) instruction, which seems
> to have similar uses (whatever they may be).
> 
> 	peter
> 
But that's not a population count (all bits set count) instruction.
In the Motorola 68020/30/40, there's BFFFO, for Bit Field Find First One,
if anyone was curious about 'find first set' instructions.  Might as well
mention that the 386/486 have BSF and BSR, Bit Scan Forward and Reverse,
but now we're just getting into run-of-the-mill bit manipulation.






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