On AMD64, some types differ in size from x86:
Type 	        x86 (ILP32) 	amd64 (LP64)
char          	1 byte          1 byte
short       	2 bytes         2 bytes
int 	        4 bytes         4 bytes
long 	        4 bytes         8 bytes
long long 	8 bytes         8 bytes
pointer 	4 bytes         8 bytes
float 	        4 bytes         4 bytes
double    	8 bytes         8 bytes
long double 	16 bytes        16 bytes