[Bug tree-optimization/61607] DOM missed jump threading and destroyed loops

["rguenth at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61607

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Thu Jun 26 11:29:34 2014
New Revision: 212026

URL: https://gcc.gnu.org/viewcvs?rev=212026&root=gcc&view=rev
Log:
2014-06-26  Richard Biener  <rguenther@suse.de>

    PR tree-optimization/61607
    * tree-ssa-copy.c (copy_prop_visit_phi_node): Adjust comment
    explaining why we restrict copies on loop depth.
    * tree-ssa-dom.c (cprop_operand): Remove restriction on
    on loop depth.
    (record_equivalences_from_phis): Instead add it here.

    * gcc.dg/tree-ssa/ssa-dom-thread-5.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-5.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-copy.c
    trunk/gcc/tree-ssa-dom.c