Correct me if I am wrong,
int is 4 bytes, with a range of values from -2,147,483,648 to 2,147,483,647 (2^31)
long is 4 bytes, with a range of values from -2,147,
When compiling for x64, the difference between int and long is somewhere between 0 and 4 bytes, depending on what compiler you use.
GCC uses the LP64 model, which means that ints are 32-bits but longs are 64-bits under 64-bit mode.
MSVC for example uses the LLP64 model, which means both ints and longs are 32-bits even in 64-bit mode.