implement 64-bit arithmetic on a 32-bit machine

Question

The following code computes the product of x and y and stores the result in memory. Data type ll_t is defined to be equivalent to long long.

typedef long lon         


        

Answer 1

What imul does is multiplies the contents of eax with ecx and saves the lower 32 bits in eax and higher 32 bits in edx.

addl as far as I remember adds the two registers and saves it on the first one so in this case ebx. (I am not sure if it does anything else and the l after addl stands for long)