Date: Wed, 7 Mar 2018 14:00:44 +0100
From: Joerg Sonnenberger <jo...@bec.de>
| This is a transformation typically done already.
I thought it might be with modern compilers - but it probably was not when
atan2() was originally written, But demonstrating that cannot hurt.
And if we want to be more sure then perhaps:
if(((hx^0x3ff00000)|lx)==0) return atan(y); /* x=1.0 */
would be a suitable replacement (probably formatted in a more KNF compat