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From: cik@l.cc.purdue.edu (Herman Rubin)
Newsgroups: comp.arch
Subject: Re: Computer Architecture methodology
Summary: Users can also use odd instructions.
Keywords: A Series, B6700
Message-ID: <2322@l.cc.purdue.edu>
Date: 8 Jul 90 12:35:41 GMT
References: <8533@canterbury.ac.nz> <14279@burdvax.PRC.Unisys.COM> <844@tredysvr.Tredydev.Unisys.COM>
Distribution: comp.arch
Organization: Purdue University Statistics Department
Lines: 28

In article <844@tredysvr.Tredydev.Unisys.COM>, barry@tredysvr.Tredydev.Unisys.COM (Barry Traylor) writes:
> In article <3329@goanna.cs.rmit.oz.au> ok@goanna.cs.rmit.oz.au (Richard A. O'Keefe) writes:
> >
> >I would love to hear about which of the hardware instructions are now
> >regarded as obsolescent and ill conceived.  Are LLLU and SRCH on the way
> >out?

			............................

> LLLU (linked list lookup, pronounced lulu), has been deimplemented for all
> recent and future machines;  it was an operating systems instruction that
> fell out of use.  SRCH (Masked Search) and BMS (bounded masked search, a
> new op) are alive, healthy and heavily used in the OS.

			...........................

Users can make use of weird instructions.  Instead of insisting that they 
use the ill-conceived limitations of HLLs, encourage them to use the power
of these instructions that the HLL producers do not know how to use.  You
will find that there are good applications uses of most of them.

Mr. Taylor goes on to say that some instructions were eliminated because
they could be done faster under certain conditions.  It was not clear if
these conditions were universal, or depended on the type of program.
-- 
Herman Rubin, Dept. of Statistics, Purdue Univ., West Lafayette IN47907
Phone: (317)494-6054
hrubin@l.cc.purdue.edu (Internet, bitnet)	{purdue,pur-ee}!l.cc!cik(UUCP)