结合上图解读源码:
--指令格式里的大小和位置
#define SIZE_C 9
#define SIZE_B 9
#define SIZE_Bx (SIZE_C + SIZE_B)
#define SIZE_A 8
#define SIZE_OP 6
#define POS_OP 0
#define POS_A (POS_OP + SIZE_OP)
#define POS_C (POS_A + SIZE_A)
#define POS_B (POS_C + SIZE_C)
#define POS_Bx POS_C
原文:https://www.cnblogs.com/Jaysonhome/p/13414005.html