https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42117
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
So I think VRP is almost there on the trunk, it just needs to know if you have
a range of a and that a is defined by b|c, then b and c ranges can be just the
same as a.
That is:
_10 = x_5(D) | y_6(D);
_11 = (unsigned int) _10;
if (_11 <= 1)
goto <bb 3>; [57.43%]
else
goto <bb 4>; [42.57%]
2->3 (T) _10 : [irange] int [0, 1] NONZERO 0x1
2->3 (T) _11 : [irange] unsigned int [0, 1] NONZERO 0x1
2->4 (F) _10 : [irange] int [-INF, -1][2, +INF]
2->4 (F) _11 : [irange] unsigned int [2, +INF]
We should have done:
2->3 (T) x_5(D) : [irange] int [0, 1] NONZERO 0x1
2->3 (T) y_6(D) : [irange] int [0, 1] NONZERO 0x1
...
This is only true for bit_ior.
