Re: cpow

In reply to: Paul Zimmermann : "cpow"
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From: Steve Kargl <kargls_at_comcast.net>
Date: Wed, 10 Sep 2025 15:13:55 UTC

On 9/9/25 23:45, Paul Zimmermann wrote:
>         Hi,
> 
> we noticed that in FreeBSD 14.3, cpow(x,y) for x = y = (+0,+0) yields (+0,+0),
> whereas GNU MPC yields (1,+0), which matches the real case, where IEEE 754
> requires x^+0 = 1 when x is not a signaling NaN.
> 
> Is there any reason for the choice (+0,+0)?
> 

It seems that FreeBSD's cpow was imported from OpenBSD.
Looking at the Copyright, it was written by Stephen L.
Moshier, which means the code ultimately comes from
CEPHES.

-- 
steve