[Bug rtl-optimization/71275] [7 regression] Performance drop after r235660 on x86-64 in 32-bit mode.

amodra at gmail dot com gcc-bugzilla@gcc.gnu.org
Thu May 26 06:19:00 GMT 2016


https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71275

Alan Modra <amodra at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2016-05-26
                 CC|                            |amodra at gmail dot com
           Assignee|unassigned at gcc dot gnu.org      |amodra at gmail dot com
     Ever confirmed|0                           |1

--- Comment #2 from Alan Modra <amodra at gmail dot com> ---
Confirmed.  combine_and_move_insns is moving an insn into the innermost loop,
which it shouldn't do due to
      if (bb_loop_depth (use_bb) > bb_loop_depth (def_bb))
        continue;

However, it appears that the loop info isn't set up and bb_loop_depth is
therefore returning 0 for both basic blocks.


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