[Bug c/117266] RFE: builtins for N*N -> 2N multiplication and 2N/N -> N div/mod

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117266

--- Comment #8 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I don't think we want to introduce div2 because it will also introduce an extra
undefined behavior. Plus it is only 86 which has that instruction.