| [eigen] Re: SSE square root |
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- To: eigen@xxxxxxxxxxxxxxxxxxx
- Subject: [eigen] Re: SSE square root
- From: Rohit Garg <rpg.314@xxxxxxxxx>
- Date: Fri, 27 Mar 2009 14:07:07 +0530
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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
>
--
Rohit Garg
http://rpg-314.blogspot.com/
Senior Undergraduate
Department of Physics
Indian Institute of Technology
Bombay