__pixel_format_cmp_bitfield
__pixel_format_cmp_bitfield(lhs, rhs, index);
__pixel_format_cmp_bitfield(lhs, rhs, alpha);
__pixel_format_cmp_bitfield(lhs, rhs, red);
__pixel_format_cmp_bitfield(lhs, rhs, green);
__pixel_format_cmp_bitfield(lhs, rhs, blue);