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Re: floor on i386


On Wed, Sep 26, 2001 at 01:14:36PM +0200, Jan Hubicka wrote:
> > Note, that this optimization is necessary if gcc don't want to have 4% of
> > the performance of icc for Intel iA32. For example a MPEG-2 Layer 2 decoder
> > spends 65% of the execution time in rounding floats to integers (Athlon).
> > This is not a joke, it's a flaw of the compiler.
>
> Can't it just use rint function, as disucssed earlier?
> 
No.

1st:  rint() is faster, but also very slow (14x slower than optimum)
2nd:  There's no subset of function to select another standard rounding
      model.

-- 
Frank Klemm


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