Michael Sung <mys@xxxxxxxxx> writes: There is no reason to send one e-mail to both gcc-help@xxxxxxxxxxx and gcc@xxxxxxxxxxxx This message is more appropriate for gcc-help. Thanks. > a) What is the default for gcc regarding "pack" or "unpack" data structures? If I understand your question correctly, the answer is that gcc normally does not pack data structures. It normally aligns members of data structures on their natural alignment, which leads to more efficient code. > b) Is there a compiler flag for gcc compiler that will pack all data > structures? Yes, -fpack-struct. Ian
