#include<stdio.h>

int main(){
	register int x = 40;
	int y = 92;
	printf("x = %d, y = %d\n", x, y);
/*	asm("add %ebx, %ebx"); */ // Works, kind of
/*	asm("mov %0, %1; add %1, %1; mov $27, %0  "
		: "=r"(x),"=r"(y)
		: "r"(x)
		);
*/  /* Evidence suggests you shouldn't re-order x and y */
	asm("mov %%eax, %%ebx; add %%ebx, %%ebx; mov $27, %%eax"
		: "=a"(x), "=b"(y)
		: "a"(x), "b"(y)
		);

	printf("x = %d, y = %d\n", x, y);
	return 0;
}