[Bug middle-end/126883] inline ilogb if the argument is normal

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126883

--- Comment #1 from Drea Pinski <pinskia at gcc dot gnu.org> ---
Just a huge hint here, there is a method of frange for this: known_isnormal .