The result from the optmisation shows that Soot can reduce the file size by 8.5%. This number is expected to be large when we apply the optimisation to the whole program.
This is an updated result when applying the more complex optimisation to two of Groovy packages, groovy.lang and groovy.xml.
> soot.Main -O -via-shimple -process-dir groovy-1.1
Please note that not all Groovy classes were used in this experiment. Just two mentioned packages resides in the "groovy-1.1" folder. This experiment has done by performing optimisation package that requires Static Single Assignment (SSA) representation of Java classes. Soot supports this through Shimple format. The "-via-shimple" option shown in the command line is to enable this kind of optimisation. The result is better than using only Jimple optimsation. Size of Groovy classes in the two packages is reduced by 16.34%.