[Cfp-interest 1865] Re: copysign(x,-NAN)

[Jim Thomas]

> On Nov 25, 2020, at 10:36 AM, Fred J. Tydeman <tydeman at tybor.com> wrote:
> 
> In looking more at IEEE-754-2019, I see that there are two definitions
> of copysign() and that I was looking at the wrong one during our teleconference.
> 
> For arithmetic interchange formats, NaNs have a sign bit and it is set or copied
> by copysign.  I missed this one on my quick read.
> 
> For non-interchange formats, NaN has an unspecified sign.  This is what I was
> looking at during the call.

Right. That’s in IEEE 754-2019 5.5.1.

- Jim Thomas
> 
> 
> ---
> Fred J. Tydeman        Tydeman Consulting
> tydeman at tybor.com      Testing, numerics, programming
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