c/10176: Broken nested Do loop: simple example. gcc 3.2 redhat

[bangerth@dealii.org]

Synopsis: Broken nested Do loop: simple example. gcc 3.2 redhat

State-Changed-From-To: open->feedback
State-Changed-By: bangerth
State-Changed-When: Fri Mar 21 01:51:28 2003
State-Changed-Why:
    Your program 4x.c is essentially equivalent to this one:
    --------------------------
    int main(void)
    {
      unsigned int count = 1;
      do {
        if( count % 3 ) { count *= 4; count += 2; }
        else            { count /= 3; }
        
        if( count == 1 ) break;
        if( count == 3 ) break;
      } while(1);
      return(0);
    }
    ----------------------
    What happens is that you never jump out of the inner loop.
    Unfortunately, I don't see right away why the loop should
    terminate at all. gcc seems to have the same problem, as
    does icc. Can you give a simple argument why it should?
    
    Thanks
      Wolfgang

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10176