On Fri, 11 Mar 2016, Eric Botcazou wrote:
> > The following teaches phiprop to handle the case of aggregate copies
> > where the aggregate has non-BLKmode which means it is very likely
> > expanded as reg-reg moves (any better test for that apart from
> > checking for non-BLKmode?).
>
> !aggregate_value_p comes to mind, but non-BLKmode is the definitive test to
> distinguish the register from the non-register case at the RTL level.
It looks like it might catch a few extra cases where the address of the
decl is required. But it also looks like it's somewhat overly broad like
/* Function types that are TREE_ADDRESSABLE force return in memory. */
if (fntype && TREE_ADDRESSABLE (fntype))
return 1;
without actually testing 'exp' is the return slot. In fact most of
the function cares about function return values and some about
parameters. I guess the predicate should be split up (a quick grep
shows most callers care about the return value case).
Richard.
