[Bug tree-optimization/81455] [7 Regression] Compile-time hog w/ -O1 -funswitch-loops

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81455

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |8.0
            Summary|[7/8 Regression]            |[7 Regression] Compile-time
                   |Compile-time hog w/ -O1     |hog w/ -O1 -funswitch-loops
                   |-funswitch-loops            |

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Tue Jul 25 13:24:51 2017
New Revision: 250518

URL: https://gcc.gnu.org/viewcvs?rev=250518&root=gcc&view=rev
Log:
2017-07-25  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/81455
        * tree-ssa-loop-unswitch.c (find_loop_guard): Make sure to
        not walk in cycles when looking for guards.

        * gcc.dg/pr81455.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/pr81455.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-loop-unswitch.c