[Bug c/26004] [4.1/4.2 Regression] gcc errors on valid code [SVO]

["amylaar at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>]

------- 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.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26004