SIZE_C
#define GETARG_C(i) getarg(i, POS_C, SIZE_C)
#define SETARG_C(i,v) setarg(i, v, POS_C, SIZE_C)
#define SIZE_Bx (SIZE_C + SIZE_B)
#define SIZE_Ax (SIZE_C + SIZE_B + SIZE_A)
#define POS_B (POS_C + SIZE_C)
#define MAXARG_C ((1<<SIZE_C)-1)