This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: On alignment
Jason Merrill writes:
> On Sat, 22 Mar 2003 09:12:32 +0000 (GMT), Andrew Haley <aph at redhat dot com> wrote:
>
> > Jason Merrill writes:
> > > Can you give me an example of a case that needs an aligned attribute? What
> > > is the Java frontend doing that makes this necessary?
> >
> > http://gcc.gnu.org/ml/gcc-patches/2003-03/msg00429.html
>
> OK, you're trying to suppress the tail padding optimization. It occurred
> to me that another way to express that could be
>
> struct B : A {
> // force normal alignment
> char : 0 __attribute ((__aligned (__alignof (A))));
> short bs;
> };
>
> but of course that doesn't work properly either; user-specified
> alignment is currently ignored on a zero-length bitfield. But
> that's a one-line fix, and shouldn't create a compatibility
> problem, since there would have been no point in specifying such an
> alignment before. Would that work for you?
Excellent. That's all I need.
Andrew.