When x and y are both unsigned int (x*y) is also an unsigned int.
(long int)(x*y) means first compute the unsigned in (x*y) then promote
it to long int.
To get the answer you want, you need to promote one of the arguments of
the multiply before multiplying. I don't know whether the optimizer
will figure out to do the 32 bit multiply you want and store the 64 bit
result or whether it would do a 64 bit multiply.
Also, are you sure (long int) is 64 bit? I thought it was just 32.
Bob Plantz wrote:
I wrote some C code to multiply two unsigned (32-bit) ints and store the
result in a 64-bit unsigned int.
int main(void)
{
unsigned int x, y;
unsigned long int z;
printf("Enter two integers: ");
scanf("%u %u", &x, &y);
z = (long int)(x * y);
