[Bug middle-end/70239] [6 Regression] ICE in ggc_set_mark

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70239

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2016-03-15
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org
   Target Milestone|---                         |6.0
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
I get

> ./cc1 -quiet t.c -Os -w
t.c: In function ‘d5’:
t.c:7:1: internal compiler error: Segmentation fault
 d5(void)
 ^~
0xe551b6 crash_signal
        /space/rguenther/src/svn/trunk3/gcc/toplev.c:335
0xe9de22 verify_gimple_assign_unary
        /space/rguenther/src/svn/trunk3/gcc/tree-cfg.c:3554
0xea0895 verify_gimple_assign
        /space/rguenther/src/svn/trunk3/gcc/tree-cfg.c:4333

which means we have a released SSA name in the IL.

(gdb) p debug_gimple_stmt (stmt)
_11005 = () hb.6_8035;

and _11005 is released.  (thus the odd cast to nothing)

Happens after FRE.  Thus mine for now.