[Bug tree-optimization/68465] pass_lim doesn't detect identical loop entry conditions

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68465

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Mon Nov 23 15:21:32 2015
New Revision: 230764

URL: https://gcc.gnu.org/viewcvs?rev=230764&root=gcc&view=rev
Log:
2015-11-23  Richard Biener  <rguent...@suse.de>

        PR tree-optimization/68465
        * tree-ssa-sccvn.c (sccvn_dom_walker::before_dom_children):
        Also record equalities from multiple predecessor blocks if
        only one non-backedge exists.

        * gcc.dg/tree-ssa/ssa-fre-52.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-52.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-sccvn.c