[Bug tree-optimization/87776] [9 Regression] Compile time hog during RPO VN

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87776

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Fri Nov  2 07:53:48 2018
New Revision: 265739

URL: https://gcc.gnu.org/viewcvs?rev=265739&root=gcc&view=rev
Log:
2018-11-02  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/87776
        * tree-ssa-sccvn.c (do_rpo_vn): Do not mark backedges
        executable when iterating but running into rpo-vn-max-loop-depth
        and not eliding the iteration.

        * gcc.dg/torture/pr87776.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/torture/pr87776.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-sccvn.c