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From: dd@mips.com ("BOB requires a human host!  He feeds on fear... and the pleasures.")
Newsgroups: comp.arch
Subject: Re: skip instructions
Message-ID: <3027@spim.mips.COM>
Date: 3 May 91 21:32:47 GMT
References: <1182@opus.NMSU.Edu>
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In article <1182@opus.NMSU.Edu> jthomas@nmsu.edu (James Thomas) writes:
>Is there a reference (or more) describing why SKIP instructions have mostly
>disappeared from instruction sets?  The 704x and 709x had them, so the
>PDP-6 had them (and maybe therefore the PDP-8 inherited them).  Now the
>HP-PA has them hiding in the guise of the nullify bit.  Are conditional
>branches generically more useful?

SPARC also has them, in the guise of annulled branches.  In current
implementations they're no faster than any other branch, and I don't think
the Sun compilers make an effort to use them.

--
David DiGiacomo, MIPS Computer Systems, Sunnyvale, CA  dd@mips.com