[Bug middle-end/54838] [4.8 Regression] ICE: in merge_latch_edges, at cfgloop.c:678 with -ftracer

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54838



--- Comment #18 from Richard Biener <rguenth at gcc dot gnu.org> 2012-12-18 
14:39:55 UTC ---

Author: rguenth

Date: Tue Dec 18 14:39:49 2012

New Revision: 194582



URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=194582

Log:

2012-12-18  Richard Biener  <rguent...@suse.de>



    PR middle-end/54838

    * cfgloopmanip.c (fix_loop_structure): Re-discover latch

    edges first and mark loops for removal if no latch edges remain.

    Properly re-create LOOPS_HAVE_FALLTHRU_PREHEADERS.

    * loop-init.c (loop_optimizer_finalize): Set

    LOOPS_MAY_HAVE_MULTIPLE_LATCHES.



    * g++.dg/torture/pr54838.C: New testcase.



Added:

    trunk/gcc/testsuite/g++.dg/torture/pr54838.C

Modified:

    trunk/gcc/ChangeLog

    trunk/gcc/cfgloopmanip.c

    trunk/gcc/loop-init.c

    trunk/gcc/testsuite/ChangeLog