DATA_ALIGNMENT vs. DECL_USER_ALIGNMENT

[Alexandre Oliva]

On Apr 22, 2003, kenner@vlsi1.ultra.nyu.edu (Richard Kenner) wrote:

>     But the compiler can't tell whether, when you specify alignment for a
>     type, you mean for interface or for efficiency, so I think it
>     shouldn't make an assumption that it's to be used only for the former
>     case like you seem to believe it should do.

> No, I don't believe that, but it's not relevant.  Because it *might*
> have been meant for interface, the compiler is not allowed to change
> the alignment of types.

The point is that you're saying it could increase the alignment of an
object in spite of a user-specified alignment for its type.  You can't
tell whether the alignment was defined for interface, space or
performance, so a user-specified alignment for a type should be
obeyed.

-- 
Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Red Hat GCC Developer                 aoliva@{redhat.com, gcc.gnu.org}
CS PhD student at IC-Unicamp        oliva@{lsd.ic.unicamp.br, gnu.org}
Free Software Evangelist                Professional serial bug killer