Article View: comp.arch
Article #11039Re: integer distance or sqrt
From: David Magagnosc
Date: Tue, 17 Nov 1992 14:39
Date: Tue, 17 Nov 1992 14:39
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1737 bytes
This reminds me of something I came up with not long after the Midatlantic ACM Region Programming Contest last year. One of the problems involved computing square roots by the long division-like method (which they claimed we all learned in elementary school). I translated it to binary, applied the techniques used for division, and came up with a sort of non-restoring square root. Now, the convergence is linear (2 bits of input for 1 bit of output per iteration), but it uses only elementary operations like shifts and adds, so its run time should be comparable to a single division. Newton's method, on the other hand, typically uses division on every iteration. So, the real question is, has someone done something like this before? How does it really compare for smallish (under 32 or maybe even 64 bit) square roots? Oh yes, it can also be extended very easily to compute fixed point square roots of integers -- as many bits as you like. D. Magagnosc -- 496620796F752063616E207265616420746869732C20796F752063616E206265636F6D65206120 636F6D70757465722070726F6772616D6D657220616E6420676574206120676F6F64206A6F622E
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Path: arc1-ca.pugleaf.net!sparky!uunet!pmafire!mica.inel.gov!ux1!news.byu.edu!hamblin.math.byu.edu!sol.ctr.columbia.edu!usc!cs.utexas.edu!qt.cs.utexas.edu!yale.edu!jvnc.net!netnews.upenn.edu!netnews.noc.drexel.edu!king.mcs.drexel.edu!dmagagno From: dmagagno@mcs.drexel.edu (David Magagnosc) Newsgroups: comp.arch Subject: Re: integer distance or sqrt Message-ID: <1992Nov17.143914.19700@mcs.drexel.edu> Date: 17 Nov 92 14:39:14 GMT References: <55F0TB1w165w@tsoft.sf-bay.org> <CLIFFC.92Nov15184340@miranda.rice.edu> <MOSS.92Nov16094710@CRAFTY.cs.cmu.edu> Organization: Drexel University Lines: 24