gcj slower than JVM on RedHat/s390?

Tom Tromey tromey@redhat.com
Wed Apr 2 18:04:00 GMT 2003


>>>>> "Andy" == Andy Faibishenko <AFAIBIS@transunion.com> writes:

Andy> I have a small test program which I use as a benchmarking tool.
Andy> It doesn't use threads/jdbc/etc.. - i.e. plain vanilla java
Andy> code.  When I compiled it with GCJ I was surprised to find that
Andy> it takes up almost TWICE as much CPU time as the JVM version (as
Andy> reported by the time command).  I am trying to figure out why
Andy> this is.

Andy> Any suggestions would be greatly appreciated.

Your best bet would be to try to look at the generated assembly and
see what is happening.  We'd be interested in the results.

I'm not super surprised by your finding.  The IBM JIT is excellent.
Also, we haven't put a lot of time into optimizations.  There are
still improvements we could make...

Tom



More information about the Java mailing list