/* regtest3.c - An example of using placeholders for a common value */#include <stdio.h>int main(){   int data1 = 10;   int data2 = 20;   asm ("imull %1, %0"        : "=r"(data2)        : "r"(data1), "0"(data2));   printf("The result is %d\n", data2);   return 0;}