SEGV in do_simple_structure_copy

[Olivier Hainque]

Daniel Berlin wrote:
> >    <field_decl 0xb7429398 x type <integer_type 0xb7429450>
> >       size <integer_cst 0xb742fd98 constant invariant 3>

> >    <integer_type 0xb7429450 sizes-gimplified public QI
> >       size <integer_cst constant invariant 8>
> >       precision 3 min <integer_cst -4> max <integer_cst 3>>
> 
> You'll note we actually created a new type for this :)

 Indeed, and I think we also have that in Ada, my confusion. The
 TYPE_SIZE is still larger than the DECL_SIZE above, and the field 
 really doesn't occupy a slot as large as what TYPE_SIZE says.

> Thinking harder about it, you might be better off then making  
> everything based on TYPE_SIZE then, since we don't always have the  
> FIELD_DECL's handy.

 I'm not sure we can.

 I think we must have an integral mode (and size)  for the type to be
 able to place the field on a non-byte-aligned boundary.