[Bug target/83210] __builtin_mul_overflow() generates suboptimal code when exactly one argument is the constant 2

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83210

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(res >> 3) != src;

Why not just (src>>(sizeof (res)*8-3))!=0.

Seems shorter and might be faster.