Help with performance issues.

[Andrew Haley <aph at cambridge dot redhat dot com>]

Bill Bland writes:

 > 	We were having problems with the performance of our java
 > application under sun's jdk1.3 (using Mandrake linux 8 on an i686).
 > I decided to try gcj to see if it would run faster.  I got the
 > source for gcc 3.0 and followed the installation instructions, and
 > after a few tweeks (took out some awt stuff) it compiled our
 > application.
 > 
 > Unfortunately it now runs slower :-(

How much slower is it?  

It's possible that jdk generates near-optimal code for simple loops
and that we're missing some optimization tricks.  An important issue
might be, as Hans said, that we're suffering from redundant calls to
_Jv_InitClass and null pointer checkes.

If we can get a small test case that represents your code and runs
slower under gcj than jdk we might well be able to fix it.  However,
we need something real -- otherwise we're just speculating.

Do you suppose that you could create case that we could look at?

Andrew.