Re: [boost] [Review Request] Multiprecision Arithmetic Library

Subject: Re: [boost] [Review Request] Multiprecision Arithmetic Library
From: John Maddock (boost.regex_at_[hidden])
Date: 2012-04-15 13:40:29

> Both sin and mysin(pi/4) output
> 7.0710678118654752440084436210484903928483593768847403658833986900e-01 for
> me - and my calculator agrees :-)

>I guess I'm merely talking about the HTML documentation shown in
>the link below. But maybe it's already been fixed elsewhere:
>https://svn.boost.org/svn/boost/sandbox/big_number/libs/multiprecision/doc/html/boost_multiprecision/tut/floats/fp_eg/poly_eg.html
>
>The example code in the HTML documentation uses mysin(1).
>*Emphasize*: The argument is 1.

Doh! My bad, looking in the wrong place and forgot to change the argument to 
pi/4, will correct shortly.

>By the way, I looked at the compiler-generated assembly for
>that polynomial expansion using template expressions
>under x64 with VisualStudio2010. My jaw dropped to the floor!
>It's baffling what the compiler does with expression templates
>in combination with inlining, loop unrolling, constant folding, etc.
>I would like to to take a closer look at this and really comprehend
>the optimization potential.
>The state of C++ compiler technology today is truly impressive!
>I can hardly wait for VS2012 support for some of the new stuff.

Nod, getting all those one-line expression templates expanded inline is key 
here, and yes, compilers are getting pretty impressive at handling this 
stuff!

Cheers, John.