Optimization trouble

[Christopher Weth]

Hi,

when compiling the litte program below without optimization (-O or -O2),
it prints the right results; when optimization is turned on, the results
become funny...

This happens with egcs-2.91.57 on a  Linux 2.0.33 system as well as the 
gcc 2.7.2.1, Linux 2.0.33, and egcs-2.90.29 980515 (egcs-1.0.3 release) on 
IRIX  5.3 11091811 IP20; I did not try on more systems than those.

Best regards,

       Chriss

----------------------------

#include <math.h>
#include <iostream.h>

int main() {

  double ttab[3], *t1 = ttab;
  double tstep = M_PI/3;
  double th=tstep;

  *(t1++)= sin(th);

  for (int i=1; i<3; i++) {
    th+=tstep;
    *(t1++) = *(t1-1)+sin(th);
  }

  for (int j=0; j<3; j++)
    cout << ttab[j] << endl;

  return 0;
}



------------------------------------------------------------------
Christopher Weth
Institut fuer theoretische Astrophysik, Tuebingen
Tel.: (07071) / 29-78653

EMail: weth@tat.physik.uni-tuebingen.de
------------------------------------------------------------------