Article View: comp.sys.nsc.32k
Article #58Re: Timing question
From: Karl Swartz
Date: Thu, 31 Aug 1989 08:14
Date: Thu, 31 Aug 1989 08:14
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1257 bytes
In article <13223@reed.UUCP> bob@reed.UUCP (Bob Ankeney) writes:
>
> A quick question: Which (if either) is faster in execution:
According to my (ancient) manuals, for a 32032 ...
movw foo(r1),bar(r1) ; 19 cycles
movw foo[r1:b],bar[r1:b] ; 27 cycles
This assumes the source and destination words are aligned and there
are MMU delays (subtract 2 cycles from each case for no MMU). Plus
there's the time to fetch an extra two bytes of instruction for the
the indexed case.
In other words, index mode is a loser where a simpler addressing
mode can be used, certainly in this case, and probably in all cases.
--
Karl Swartz |UUCP uunet!lll-winken!ames!hc!rt1!ditka!kls
1-505/667-7777 (work) |Internet kls@rt1.lanl.gov
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"I never let my schooling get in the way of my education." (Twain)
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Path: arc1-ca.pugleaf.net!utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!sun-barr!decwrl!decvax!zinn!ditka!kls From: kls@ditka.UUCP (Karl Swartz) Newsgroups: comp.sys.nsc.32k Subject: Re: Timing question Message-ID: <3878@ditka.UUCP> Date: 31 Aug 89 08:14:50 GMT References: <13223@reed.UUCP> Reply-To: kls@ditka.UUCP (Karl Swartz) Organization: Inaction Central, Los Alamos, New Mexico Lines: 22