Arm/bits2

From ASMBits

arm/bits1Previous

A signed (two's complement) number of n bits can represent values between -2n-1 and +(2n-1-1), inclusive. Write a function that returns how many bits are needed to represent a given number, in signed binary representation.

unsigned int bits(int num);


Expected solution length: Around 5 lines.

Sample Input

0x1000

Sample Output

r0=14

Think carefully about corner cases...

Write your solution here

x
 
1
// A test case to test your function with
2
.global _start
3
_start:
4
    ldr r0, =0x1000
5
    bl bits
6
    b _start        // End of testing code
7
8
// Return minimum number of bits to represent first parameter
9
bits:
10
    
11
    
Upload a source file...