Write in ARM assembly language the following operations with

Write in ARM assembly language the following operations without using multiplication instruction

      3.1. A * 17

      3.2. A * 23

Solution

let value of R0 = A

and result is stored in R2

3.1

.text

.main:

ADD R2,R0,R0,LSL #4 // A * 17

3.2

.text

.main:

ADD R2,R0,R0,LSL #4 // A * 17

ADD R2,R2,R0 LSL #2 // A * 17 + A * 4 = A * 21

ADD R2,R2,R0 LSL #1 //A * 21 + A * 2 = A * 23