Which IR are you trying to look at, the LLVM IR or the octave linear IR?
There is not any easy way to disable checking for interrupts. The interrupt checking code inserts a branch at the start of each loop that exits the function if the user has pressed cntrl-c.
I'm glad to see that you are making progress. I know Jordi set you up with hg, can I have the link to your repository? I would like to look over your do-until implementation. Also, I'm adding the octave-maintainers list, that way we keep everyone else in the loop (we don't want them thinking you have disapeared).