ALT_FLAG_DIRECT_CALL
#define ALT_DIRECT_CALL(feature) ((ALT_FLAG_DIRECT_CALL << ALT_FLAGS_SHIFT) | (feature))
if (alt->flags & ALT_FLAG_DIRECT_CALL)
if (flags & ~(ALT_FLAG_NOT | ALT_FLAG_DIRECT_CALL))
if (flags & ALT_FLAG_DIRECT_CALL)