gcc 3.3 / i386 / -O2 question

[Beschorner Daniel]

Thank you!
The unused array Q seems to trigger somewhat, if I remove it O2 works fine.
Strange... 

Daniel

-----Ursprüngliche Nachricht-----
Von: Andrew Haley [mailto:aph@redhat.com] 
Gesendet: Dienstag, 16. November 2004 13:14
An: Beschorner Daniel
Cc: 'gcc@gcc.gnu.org'
Betreff: gcc 3.3 / i386 / -O2 question

Beschorner Daniel writes:
 > Sorry, if this is the wrong list, but why differ the results in this
simple  > example when compiled with -O and -O2 while GCC 2.95 is working
fine?
 > -fno-strict-aliasing makes no difference, but -fno-gcse-(sm) helps.
 >
 > outputs are
 > -O: -1343238496
 > -O2: -1474736480
 >
 > Thanks Daniel
 >
 >
 > int A,B,C;
 > int i;
 > int Q[1];
 > int H(int X, int Y)
 > {
 >         return X*Y;
 > }
 > int main()
 > {
 >         A=B=C=100000;
 >         A+=H(B,C);

Integer overflow.  All bets are off.

Andrew.