Re: Any pointer to Byte Alignment & Structure Padding?

[Steve Graegert <graegerts@gmail.com>]

On 8/5/05, Amit Dang <amit_dang@intersolutions.stpn.soft.net> wrote:
> Hi Steve,
>    Thanks for your prompt response and the valuable information. But I
> tried following on Linux 32-bit gcc 2.96
> struct temp {
>    long long i;
>    char c;
> } and sizeof(struct temp) gave 12 not 16.

Hmm, I have no access to a 32-bit machine right now, but I am running
GCC 3.4.2 on SPARC and sizeof(temp) gives 16 as expected.

One thing a could think of is that on 32-bit machines it makes no
sense to pad to 16 bytes since the natural word size (size of internal
registers) is 4 bytes resulting in an unnecessary read operation to
fetch the rest of the structure that is useless anyway.

Regards

	\Steve

PS: I am going to investigate this issue when I return to my lab and
will mail you the results privately if you don't mind.

--

Steve Graegert <graegerts@gmail.com>
Software Consultancy {C/C++ && Java && .NET}
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