------- Comment #4 from amylaar at gcc dot gnu dot org 2006-01-30 18:29 -------
(In reply to comment #3)
> This is caused by the following code in gimplifier:
> 3297 if (use_target)
> 3298 {
> 3299 CALL_EXPR_RETURN_SLOT_OPT (*from_p) = 1;
> 3300 lang_hooks.mark_addressable (*to_p);
> 3301 }
>
>
> Should we really be calling lang_hooks.mark_addressable, here?
>
I think the problem is actually not testing properly if the value is a
register variable first.
A few lines before in gimplify.c:gimplify_modify_expr_rhs, we have:
else if (is_gimple_reg_type (TREE_TYPE (*to_p)))
/* Also don't force regs into memory. */
use_target = false;
However, is_gimple_reg_type merely looks if the type is an aggregate.
The test that c-typeck.c:c_mark_addressable uses tests C_DECL_REGISTER .
It appears we actually don't have any way to query from the
frontend-indenpendent code if we can mark something as
safely.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26004
