https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54571
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #1)
> Confirmed. The natural place to optimize this is the tree level phiopt pass.
>
> <bb 2>:
> _3 = x_2(D) & 2;
> if (_3 != 0)
> goto <bb 3>;
> else
> goto <bb 4>;
>
> <bb 3>:
> y_5 = y_4(D) | 1;
>
> <bb 4>:
> # y_1 = PHI <y_4(D)(2), y_5(3)>
>
> where we should handle
>
> int f1(int x, int y, int d) { int tem; if ((tem = x & d)) y |= tem; return
> y; }
>
> as well. Yes, that's just y |= x & d, but it falls out naturally if the
> transform is implemented in a generic enough way.
This one should be easy to add to match.pd:
(simplify
(cond @1 (ior @2 INTEGER_CST@3) @2)
(ior @2 (bit_and (negate (convert @1)) @3)))
(bit_and (negate (convert thurth_value@1)) integer_onep)
should be just converted to:
@1
Which is not done right now, I fill that as a bug.
