> >Index: gimple-fold.c
> >===================================================================
> >--- gimple-fold.c (revision 221170)
> >+++ gimple-fold.c (working copy)
> >@@ -263,7 +263,16 @@ get_symbol_constant_value (tree sym)
> > {
> > val = canonicalize_constructor_val (unshare_expr (val), sym);
> > if (val && is_gimple_min_invariant (val))
> >- return val;
> >+ {
> >+ if (!useless_type_conversion_p (TREE_TYPE (sym),
> >TREE_TYPE (val)))
> >+ {
> >+ if (operand_equal_p (TYPE_SIZE (TREE_TYPE (sym)),
> >+ TYPE_SIZE (TREE_TYPE (val)), 0))
> >+ return NULL_TREE;
>
> And no, I don't think this is sane. Callers need to handle mismatches IIRC.
OK, I am little bit confused about your MEM_REF suggestion. So you mean that
MEM_REF should be added around all references to symbol that is an alias?
Where it is done? Is there a reason why we do not add MEM_REF always? I would
like to keep optimization passes (like ipa-visibility or ICF) to turn symbol
into an alias without having to update underlying IL.
Concerning callers handling mismatches, the VIEW_CONVERT_EXPR thing seems valid
thing to do for all uses except for fold_const_aggregate_ref_1. So perhaps
we can just inline rest of get_symbol_constant_value in there and document that
get_symbol_constant_value returns value in correct type.
Or am I missing something obvious?
Thanks!
Honza
>
> >+ val = fold_unary (VIEW_CONVERT_EXPR, TREE_TYPE (sym), val);
> >+ }
> >+ return val;
> >+ }
> > else
> > return NULL_TREE;
> > }
>
