软件逆向除法学习

钱老师曾经讲过的：

https://bbs.pediy.com/thread-116974.htm

除法转乘法:

除以2的情况:

Release

libnative_lib.so:F3504F10 00 EB D0 70 ADD.W           R0, R0, R0,LSR#31 //r0右移３１位得到1　r0=r0+1
libnative_lib.so:F3504F14 40 10       ASRS            R0, R0, #1   //算术右移1位，效果等同于 /2
libnative_lib.so:F3504F16 70 47       BX              LR

imul    rsi, uNum, 613566757  //除以7的情况
shr     rsi, 20h.   //2^32 /613566757 = 6.99 =7所以这里是除以7