Help with performance issues.

Tue Jul 31 06:31:00 GMT 2001

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.