[Bug tree-optimization/82129] New: [8 Regression] ICE in compute_antic, at tree-ssa-pre.c:2447

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82129

            Bug ID: 82129
           Summary: [8 Regression] ICE in compute_antic, at
                    tree-ssa-pre.c:2447
           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-alpha20170903 snapshot (r251628) ICEs when compiling the following
snippet w/ -O2, -O3, or -Ofast:

int pj;

void
g4 (unsigned long int *bc, unsigned long int *h5)
{
  if (pj != 0)
    {
      int ib = 0;

      while (bc != 0)
        {
 m6:
          for (pj = 0; pj < 2; ++pj)
            pj = 0;

          while (pj != 0)
            {
              for (;;)
                {
                }

              while (ib != 0)
                {
                  unsigned long int tv = *bc;
                  unsigned long int n7;

                  *bc = 1;
                  while (*bc != 0)
                    {
                    }

 ut:
                  if (pj == 0)
                    n7 = *h5 > 0;
                  else
                    {
                      *h5 = tv;
                      n7 = *h5;
                    }
                  ib += n7;
                }
            }
        }

      goto ut;
    }

  goto m6;
}

% gcc-8.0.0-alpha20170903 -O2 -c vbgefb2z.c                         
during GIMPLE pass: pre
vbgefb2z.c: In function 'g4':
vbgefb2z.c:4:1: internal compiler error: in compute_antic, at
tree-ssa-pre.c:2447
 g4 (unsigned long int *bc, unsigned long int *h5)
 ^~