> I got a problem on Jikes RVM instruction formats. I'm trying to add
> extra optional operand for instruction formats. Everything were going ok
> except Call.


One thing that might be useful is to try to build an ExtremeAssertionsOptAdaptiveCopyMS configuration.  One of the things we do in the "Extreme" variants is inject assertion checking on all uses of instruction formats.

It might also be worth looking at the generated Call class to make sure that it is doing what you think it is.