JUMP3
# define JUMP3(FUNC, THIS, X1,X2,X3) _IO_JUMPS_FUNC(THIS)->FUNC.pfn (THIS, X1,X2,X3)
#define JUMP3(FUNC, THIS, X1,X2,X3) (_IO_JUMPS_FUNC(THIS)->FUNC) (THIS, X1,X2, X3)
