[Bug optimization/14109] New: Can not compile correctly with -O1 option on IA64.

["wf_cs at yahoo dot com" <gcc-bugzilla at gcc dot gnu dot org>]

On ia64 with -O1 the compiler runs into dead cycle compiling this C code:

void
fft (double fxr[], int m)
{
  int l;
  int le;
  double u1 = 1.0;
  double w1;

  l = 1;
  while (1)
    {
      if (l > m)
        break; 
      {
        int count_12;
        int vaI_11;

        le = 1;
        vaI_11 = 2;
        count_12 = l;
        while (1)
          {
            if ((count_12 & 1) == 1)
              {
                le = le * vaI_11;
              }
            count_12 = count_12 / 2;
            if (count_12 == 0)
	      break;
            vaI_11 = vaI_11 * vaI_11;
          }
      }
      u1 = 1.0;
      w1 = cos (3.1415926 / 0.5);
      {
        int count_14;
        count_14 = le;
        while (1)
          {
            if (count_14 <= 0)
	      break;
            {
              int count_16;
              count_16 = le;
              while (1)
                {
                  if (count_16 <= 0)
		    break;
                  fxr[count_16] = fxr[count_16] + u1;
                  count_16 = count_16 - 1;
                }
            }
            u1 = u1 * w1;
            count_14 = count_14 - 1;
          }
      }
      l = l + 1;
    }
}

-- 
           Summary: Can not compile correctly with -O1 option on IA64.
           Product: gcc
           Version: tree-ssa
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: wf_cs at yahoo dot com
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14109