I just stumbled over some IRBuilder behaviour which I'm not sure about. 1) Jump/Target Pairs As far as I understood each jump target can only be used by one jump. So if multiple jumps need to jump to the same location I have to create multiple targets (one per jump) pointing to the same location. I can work with this behavior just fine - I'm just wondering what's the rationale behind this restriction? IMHO the bytecode itself does not impose that restriction. 2) IR -> AST I created some IR sequences which works perfectly fine as expected. However trying to get the compiled method's AST results in an endless loop. I assume this is expected behavior as the process IR -> AST only works for a subset of instruction sequences normally generated by Smalltalk code. But I just wanted to be sure. Thanks, Udo