Arm/pow2

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Write a function that will return whether its parameter is a power of 2. The parameter is an unsigned integer and will not be 0. 

int pow2(unsigned int num);

Expected solution length: Around 5 lines.

Sample Input

pow2(4)

Sample Output

r0=1

It is possible to do this without a loop. Consider the binary representations of (2n) and (2n-1).

Write your solution here

​x
 
1
.global _start
2
_start:
3
    ldr r0, =4
4
    bl pow2
5
1:  b 1b    // Done
6
​
7
pow2:
8
9
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