[Bug tree-optimization/81455] New: [7/8 Regression] Compile-time hog w/ -O1 -funswitch-loops

["asolokha at gmx dot com" <gcc-bugzilla at gcc dot gnu dot org>]

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

            Bug ID: 81455
           Summary: [7/8 Regression] Compile-time hog w/ -O1
                    -funswitch-loops
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Keywords: compile-time-hog
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---

gcc 7.1, as well as gcc-8.0.0-alpha20170709 snapshot, takes indefinite time
when compiling the following snippet w/ -O1 -funswitch-loops:

void
jh (unsigned int aw, int sn)
{
  int xs;

  for (xs = 0; xs < 1; ++xs)
    aw &= 1;

  while (aw < 1 || ++sn < 1)
    {
    }
}