[Bug tree-optimization/82355] New: [8 Regression] ICE in outermost_loop_in_sese, at sese.c:301

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82355

            Bug ID: 82355
           Summary: [8 Regression] ICE in outermost_loop_in_sese, at
                    sese.c:301
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---

gcc-8.0.0-alpha20170924 snapshot (r253127) ICEs when compiling the following
snippet w/ -O1 (-O2, -O3, -Ofast) -floop-nest-optimize -funswitch-loops:

int dc, at;

void
tv (int *ld, int jl)
{
  for (;;)
    {
      if (dc != 0)
        for (;;)
          {
            *ld = !!(*ld) + 1;
            for (dc = 0; dc < 3; ++dc)
              at = (jl != 0) ? *ld : 0;
          }

      while (at != 0)
        {
        }
    }
}

% gcc-8.0.0-alpha20170924 -O1 -floop-nest-optimize -funswitch-loops -c
cdenm4r6.c
during GIMPLE pass: graphite
cdenm4r6.c: In function 'tv':
cdenm4r6.c:4:1: internal compiler error: in outermost_loop_in_sese, at
sese.c:301
 tv (int *ld, int jl)
 ^~