Compute Greatest Common Divisor using Euclid's Algorithm

gcd_asm.c

#include <stdio.h>

int gcd( int a, int b ) {
    int result ;
    /* Compute Greatest Common Divisor using Euclid's Algorithm */
    __asm__ __volatile__ ( "movl %1, %%eax;"
                          "movl %2, %%ebx;"
                          "CONTD: cmpl $0, %%ebx;"
                          "je DONE;"
                          "xorl %%edx, %%edx;"
                          "idivl %%ebx;"
                          "movl %%ebx, %%eax;"
                          "movl %%edx, %%ebx;"
                          "jmp CONTD;"
                          "DONE: movl %%eax, %0;" : "=g" (result) : "g" (a), "g" (b)
                          );
    
    return result ;
}

int main(int argc, const char * argv[])
{
    printf("%d \n", gcd(30, 50));
    return 0;
}