javac: debug vs. optimized classes?

[Markus Dehmann]

The external library I am using is compiled with debug info, and it's
pretty slow.

Could I expect it to be much faster if it were compiled with
-debug:none? What about javac -O? Does that still exist?

Are there speed comparisons between debug and optimized classes?

Thanks!
Markus

 

[Thomas Fritsch]

The external library I am using is compiled with debug info, and it's
pretty slow.

Could I expect it to be much faster if it were compiled with -debug:none?

No, it will have exactly the same execution speed. The only things you can
expect are
(1) a smaller file size (by a few percent), and hence slightly shorter
download times
(2) less error information (due to missing line numbers in exception stack
traces)

 

[Roedy Green]

Are there speed comparisons between debug and optimized classes?

There is an fairly way to find out and on your particular program
where it matters most:

use the -g:none option on Javac and execute with the public JRE
java.exe to try without debug.

use the -g option on javac and execute with the private JRE java.exe
in the JDK to try with debug.

 

[Roedy Green]

No, it will have exactly the same execution speed.

Actually it would be slightly slower since some of your ram is chewed
up with line number offset tables and the like.