[Javabdd-devel] slowdown from javabdd-1.0b2 to javabdd-2.0?

[Mayur N. <mh...@cs...>]

Hi,

I was using javabdd-1.0b2 for a long time and decided to switch to
javabdd-2.0 recently but noticed a significant slowdown in the new version.
There seems to be a significant change in the source code (e.g. a lot of
functionality moved from class BDD to BDDVarSet).  Perhaps that's the reason
for the slowdown?  I'm attaching two testcases which illustrate the
slowdown; each of them creates a BDD factory and then adds 5000 random
tuples to an empty bdd.  To observe the slowdown, run:

$ javac -classpath javabdd-1.0b2.jar OldTest.java
$ javac -classpath javabdd-2.0.jar NewTest.java

$ time java -classpath javabdd-2.0.jar:. NewTest
...
1.80s user 0.03s system 98% cpu 1.857 total

$ time java -classpath javabdd-1.0b2.jar:. OldTest
...
0.34s user 0.03s system 91% cpu 0.404 total

Is there some problem with the way I'm creating the BDD factory, or the way
I'm adding tuples to the bdd being constructed?  If you cannot observe the
slowdown, try replacing the number 5000 in both test cases by say 50000
(i.e. add 50000 random tuples instead of 5000).

Thanks,

-- Mayur