[Mesa-dev] [PATCH] softpipe: Do round-to-even, not round-up.

Olivier Galibert galibert at pobox.com
Fri May 18 09:38:53 PDT 2012


On Fri, May 18, 2012 at 08:55:39AM -0600, Brian Paul wrote:
> Doesn't the rint() function do the same thing as round-to-even?
> Though, I'm not sure if rint() is available on Windows so we might 
> need your ieee754_fp32_round_half_to_even() function anyway.  I'll try 
> to look into that.

I kinda sorta tend not to care about windows :-)

But as to rint/nearbyint, what they do depend on the current rounding
mode, and given that's eventually in a library I consider mucking with
fpu mode risky, especially for a reference software renderer.  On the
gpu the problem is different, but that code is not used anyway (but I
should check const folding now that I think of it).

  OG.


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