Re: RFC: GC allocating everything with a type, part 1

[Jan Hubicka <hubicka at ucw dot cz>]

> Steven Bosscher <stevenb@suse.de> writes:
> 
> > There are at least two types that need to be special-cased (perhaps more,
> > but I haven't found them yet -- but probably not many).  These are the
> > types that do not have a fixed size, such as our core types, the unions 
> > rtx_def and tree_node.  The macros for these types accept an extra SIZE
> > argument as follows:
> >
> > #define ggc_alloc_tree_node(SIZE) \
> >   ggc_alloc_typed(gt_ggc_e_9tree_node, SIZE)
> >
> > and
> >
> > #define ggc_alloc_rtx_def(SIZE) \
> >   ggc_alloc_typed(gt_ggc_e_7rtx_def, SIZE)
> >
> > I want these defines to be generated automatically, and the only way I
> > could think of to tell gengtype about these special cases is by adding
> > an extra GTY parameter, "size_not_fixed".  That's a bit ugly, if people
> > have other suggestions then let me know please.
> 
> Would it not be appropriate to have separate type codes for every rtx
> and tree code?  This suffices to dispose of many, although not all, of
> the cases where the type doesn't determine the size.

We sometimes change codes in place, like converting reg to mem,
CODE_LAEBL to note and such.  Not sure whether it is stopper here :)

Honza
> 
> zw