Hi Vincent, > i would like to know if it is normal that long int and long long int are > 64 bits long on amd64 (I have thought that long long would have been 128 > bits long). Hmmmm. I'd have thought that on a 64-bit word-size architecture, int would be 64-bits big, long would be 128-bits big, and long long would be 256-bits big. After all, canonically, int is supposed to be the natural word size of the architecture. And long is twice that size, and long long is ... well, whatever long long is supposed to be. Good question. (I don't have an answer. Just my comment.) Sincerely, --Eljay