[Bug middle-end/37316] [4.4 Regression] Small structs are not passed correctly on hppa64-*-*

[jakub at gcc dot gnu dot org]

------- Comment #7 from jakub at gcc dot gnu dot org  2008-10-22 15:37 -------
Was the "I am reasonably sure it will only affect only E500" comment in
http://gcc.gnu.org/ml/gcc-patches/2008-06/msg00255.html
meant for this patch or the other one?
Clearly it makes a big difference.
I think the bug is that emit_group_store is called with NULL_TREE third
argument (the type) in the new assign_parm_remove_parallels function, while
previously
it has been called sometimes with NULL_TREE (if nominal_mode != passed_mode) or
nominal_type (if the modes are the same) or with passed_type in another part of
the routine.  And on PA BLOCK_REG_PASSING depends on the type, particularly has
different results if type is non-NULL and aggregate vs. NULL or non-aggregate.

--- function.c.jj10     2008-09-30 16:57:11.000000000 +0200
+++ function.c  2008-10-22 17:32:26.000000000 +0200
@@ -2436,7 +2436,9 @@ assign_parm_remove_parallels (struct ass
   if (GET_CODE (entry_parm) == PARALLEL && GET_MODE (entry_parm) != BLKmode)
     {
       rtx parmreg = gen_reg_rtx (GET_MODE (entry_parm));
-      emit_group_store (parmreg, entry_parm, NULL_TREE,
+      emit_group_store (parmreg, entry_parm,
+                       data->nominal_mode == data->passed_mode
+                       ? data->passed_type : NULL_TREE,
                        GET_MODE_SIZE (GET_MODE (entry_parm)));
       entry_parm = parmreg;
     }
patch fixes this for me (at least, from eyeballing assembly and/or RTL from a
cross compiler), though I'm not sure if data->passed_type or data->nominal_type
should be used and whether the data->nominal_mode == data->passed_mode guard is
needed or not.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37316