https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95731
Wilco <wilco at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2020-08-04
CC| |wilco at gcc dot gnu.org
Ever confirmed|0 |1
--- Comment #3 from Wilco <wilco at gcc dot gnu.org> ---
(In reply to Gabriel Ravier from comment #0)
> bool f(int a, int b)
> {
> return a >= 0 && b >= 0;
> }
>
> This can be optimized to `return (a | b) >= 0;`. LLVM does this
> transformation, but GCC does not.
For orthogonality you also want:
a < 0 && b < 0 -> (a & b) < 0
a >= 0 || b >= 0 -> (a & b) >= 0
a < 0 || b < 0 -> (a | b) < 0
