[Bug debug/60381] [4.9 Regression] ICE: in vt_expand_var_loc_chain, at var-tracking.c:8245

[aoliva at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60381

Alexandre Oliva <aoliva at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2014-03-05
          Component|middle-end                  |debug
           Assignee|unassigned at gcc dot gnu.org      |aoliva at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #4 from Alexandre Oliva <aoliva at gcc dot gnu.org> ---
Mine.  Wow, I didn't see that one coming.  I thought we only have links from
preserved values to other preserved values, but this proves this is not the
case.  A reversal of 208220 will certainly fix that, but I'm assessing the
impact of that on the pr59992 fix, and looking into combining the two table
cleanups at cselib_reset_table into a single pass.  I have a hunch there's some
remaining complexity from back when we actually visited each insn twice and had
to roll back cselib table changes.