[Bug middle-end/51895] [4.7 Regression] ICE in simplify_subreg

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51895

--- Comment #15 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-01-20 
14:40:09 UTC ---
Testing

@@ -3891,6 +3853,8 @@ decide_one_param_reduction (struct acces
     {
       by_ref = false;
       agg_size = cur_parm_size;
+      if (DECL_MODE (parm) != BLKmode)
+    return 0;
     }

   if (dump_file)

as passing a parameter by value in non-BLKmode (on the PARM_DECL) should
be good evidence to not split it down further (in this case we have
TYPE_SIZE != MODE_SIZE as well, but that's another story).

Hopefully DECL_MODE on the PARM_DECL is good enough and reflects actual
argument passing closely enough ... ?