This was also a learning experience for me.
I have often heard students say they were told that ++x is more
efficient than x++. From looking at gcc-generated assembly language, I
knew this is not always true. It's been pointed out here that the
situation is more "interesting" than I realized.
By the way, I don't like complicated expressions because I find them
more difficult to read and change. I would've written this example as
#include <stdio.h>
int main()
{
volatile int x = 20,y = 35;
x = y + x;
x += 2;
y += 2;
y = y + x;
printf("x=%d y=%d\n" ,x,y);
return 0;
}
Now the volatile type qualifier works independently from the algorithm,
the way god intended. (Of course, "volatile" implies we should expect
the unexpected.)
