Writing Assembly Code

#include <stdio.h>
int square(int i);
int main(void)
{
  int i;
  for (i=0; i<10; i++)
    {  
       printf("Square of %d is %d\n", i, square(i));
    }
 }
int square(int i)
{
return i*i;

}

C as ARM code

    AREA |.text|, CODE, READONLY
    EXPORT square
    ; int square(int i)
square
    MUL r1, r0, r0    ; r1 = r0 * r0
    MOV r0, r1         ; r0 = r1
    MOV pc, lr          ; return r0

    END

C as Thumb code

    AREA |.text|, CODE, READONLY
    EXPORT square
    ; int square(int i)
square
    MUL r1, r0, r0    ; r1 = r0 * r0
    MOV r0, r1         ; r0 = r1
    BX lr                    ; return r0

    END