[Bug c/21380] New: ICE compiling with -O

["trt at acm dot org" <gcc-bugzilla at gcc dot gnu dot org>]

When compiling the program below, gcc 4.0.0 dies with an ICE.
This also happens with gcc version 4.0.1 20050430 (prerelease)

gcc400 -v
Using built-in specs.
Target: i686-pc-linux-gnu
Configured with: ../gcc-4.0.0/configure --prefix=/opt/gcc400
Thread model: posix
gcc version 4.0.0


command line:
gcc400 -O -c foo.c

program:

void bar (void);
                                                                                
void
foo (int *diff)
{
  double deltay = 0.0;
  int Stangent = 0;
  int mindiff;
  int Sflipped = 0;
  int i;
  int Sturn, Snofit;
                                                                                
  Sturn = 1;
  if (Sturn)
    Stangent = 1;
  if (Sturn)
    {
      Sflipped = 0;
      Snofit = 1;
      while (Snofit)
        {
          Snofit = 0;
          mindiff = 0;
          for (i = 0; i < 4; i++)
            mindiff = diff[i];
          while (!Snofit && (mindiff < 0.0))
            {
              deltay = (Stangent ? deltay : 0.0);
              if (deltay < 0.0)
                Snofit = 1;
              for (i = 0; i < 4; i++)
                {
                }
            }
          if (Snofit)
            if (Sflipped)
              break;
        }
      if (Snofit)
        bar ();
    }
}

-- 
           Summary: ICE compiling with -O
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: trt at acm dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21380