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Re: std::norm improvement


On Wed, Mar 4, 2009 at 9:22 AM, Andrew Pinski <pinskia@gmail.com> wrote:
> " Still, I think
> gcc is pointlessly (is that an English word?) decreasing performance
> if ffast-math is not on (it's not on even with -O3).
> "
>
> No it is not, this is the problem here. That is from the thread you
> wrote in.

Yes, I've learned afterwards in the same thread that it is not pointless.

> You did not test every single input to figure out if your
> implementation is better or worse. ?I think it might be best if you
> tested every input include NaNs and infs. ?That is where some problems
> come into play also I think.
>

You mean like every pair of real numbers? Isn't there about 2^128 of
them (for double)? Even if a single test took a mere picosecond, that
would still eat up a trillion years...

I can certainly test all combinations of Infs and NaNs, if that's what
you meant. I'll report back with the results.

cheers


-- 
RNDr. Jaroslav Hajek
computing expert & GNU Octave developer
Aeronautical Research and Test Institute (VZLU)
Prague, Czech Republic
url: www.highegg.matfyz.cz


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