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From: kenton@abyss.zk3.dec.com (Jeff Kenton OSG/UEG)
Newsgroups: comp.arch
Subject: Re: Bitfield instructions--a good idea?
Message-ID: <1991Apr15.145856.4437@decvax.dec.com>
Date: 15 Apr 91 14:58:56 GMT
References: <1991Apr15.193425.3436@waikato.ac.nz>
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Reply-To: kenton@abyss.zk3.dec.com (Jeff Kenton OSG/UEG)
Organization: Digital Equipment Corporation - Nashua, NH
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In article <1991Apr15.193425.3436@waikato.ac.nz>, ldo@waikato.ac.nz
(Lawrence D'Oliveiro, Waikato University) writes:
|> What do RISC designers think of bitfield instructions? (A la
|> the VAX and 680x0 [x >= 2] processors: extract so many bits at
|> a certain offset, insert so many bits at a certain offset, etc.)
|> 
|> Do other people find these instructions useful?
|> 

The Motorola 88000 has bitfield instructions which execute in one cycle.  I
found them useful for stuff I did, and I miss them on other machines which
don't have them.

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==	jeff kenton		Consulting at kenton@decvax.dec.com        ==
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