Re: [eigen] Re: SSE square root |

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*To*: eigen@xxxxxxxxxxxxxxxxxxx*Subject*: Re: [eigen] Re: SSE square root*From*: Rohit Garg <rpg.314@xxxxxxxxx>*Date*: Fri, 27 Mar 2009 14:55:00 +0530*Dkim-signature*: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type :content-transfer-encoding; bh=Up6r9tKgnAhNe/zMiyZT8cnsad/Mu1319l9NoFAjTnw=; b=rlLk6oCk/dD/t+lK76N68p1ntG4nOqXCBSYiw2K8XfTU2glRUB+ciHsPTPyQvPMifM PUUg7sHoei8KZFY4JHaYHSAvQ8jfKYtKOlbjICJxbTNYaaxTeVbd6C5/HwQakqG2R2K0 asPocuocl6mQL+W4V1DxR4HXURiXG1DOlVYug=*Domainkey-signature*: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; b=TE/pkXRSJvuTKrnsOPFeZj7qpxyYhTVDsOiqPBYVGvHyt87its5tQoBFfVQ9v8KObe dN2iex0rd+MZJj3VK/Yr2vayxwPih1b7mmflR/pli56eTTYkxn+oFt46jrVwnV+Z/TEV dmyARhOzjiIw4Tk2sePWM5klHb5Rc/armZdhg=

It could be, but I wrote the scaffolding to test the errors. I was under the impression that only the ei_psqrt will make into the trnscendental functions.h file On Fri, Mar 27, 2009 at 2:50 PM, Christian Mayer <mail@xxxxxxxxxxxxxxxxx> wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA256 > > This looks lika candidate for a templated version that takes the number > of iterations as the template parameter... > > Rohit Garg schrieb: >> I compared the absolute accuracy in the [0,1] interval and I found >> that only one iteration is enough for accuracy purposes, which seems >> about right. >> >> On Fri, Mar 27, 2009 at 1:02 PM, Rohit Garg <rpg.314@xxxxxxxxx> wrote: >>> This file has my sse float implementation for square root. The SSE >>> square root instruction has only 12 bits of precision so extra >>> iterations of Newton Raphson may be neccessary. How many of the are >>> neccessary, I don't know. the max error I was getting was O(1e-8) in >>> [0,1]. The cephes implementation has square root only for limited >>> range. They do some other hacks to take care of range. I'll look into >>> implementing those later. For now, this should be an acceptable for >>> the fast implementations of square root atleast. >>> >>> Regards, >>> >>> -- >>> Rohit Garg >>> >>> http://rpg-314.blogspot.com/ >>> >>> Senior Undergraduate >>> Department of Physics >>> Indian Institute of Technology >>> Bombay >>> >> >> >> > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.9 (GNU/Linux) > > iEYEAREIAAYFAknMml8ACgkQoWM1JLkHou368gCfb8zF8tx8rTExdofW24Z6Xe/m > S/YAnj71fu2J7LWyaqB7tOOglY15E4Ng > =kTgD > -----END PGP SIGNATURE----- > > > -- Rohit Garg http://rpg-314.blogspot.com/ Senior Undergraduate Department of Physics Indian Institute of Technology Bombay

**References**:**[eigen] SSE square root***From:*Rohit Garg

**[eigen] Re: SSE square root***From:*Rohit Garg

**Re: [eigen] Re: SSE square root***From:*Christian Mayer

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