[cfp-interest 3662] Re: ISO 60559 6.3 and C2Y F3.3#7

[Fred J. Tydeman]

On Thu, 16 Oct 2025 19:23:20 +1100 (AEDT) Damian McGuckin wrote:
>
>
>The former says
>
>       When either an input or result is a NaN, this standard does not
>       interpret the sign of a NaN.
>
>The latter qualifies this with
>
>       ... NaNs whose sign bit is not generally interpreted by
>       ISO/IEC 60559
>
>The former uses "not interpret".
>
>So should "generally" be deleted in C2Y or is generally meant to handle those cases where a NaN is neither input nor 
>result?

I believe that copysign is one function that cares about the
sign of the input NaN.  And also an output NaN.

Assuming NAN is the same as +NAN:

copysign( NAN, -1.0 )  should end up as -NAN
copysign( 1.0, -NAN ) should end up as -1.0


---
Fred J. Tydeman        Tydeman Consulting
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