search for: endchanges

...nsider hoisting chained instructions out of a loop one at a time. The live ranges of the intermediate steps look completely different from the final result. So for a future automatic liveness API, I imagine something like: LIS.beginChanges(); .. Move multiple instructions around. .. LIS.endChanges(); [Or it could use RAII, that's not important] MachineFunction would provide observer hooks that LIS can use to collect a set of changed instructions. The call to LIS.endChanges() would then recompute the invalid live ranges. /jakob

Jakob, Seems like an easy solution for this case... But let me ask you a more general question. The reason I kept on hanging on to the MBB->splice was (probably outdated) assumption that it will one day properly update liveness for instructions it moves... That is a serious matter for what I am trying to do (global code motion in presence of bundles). What is the current thinking? Will

...use LIS does not work that late)... which is something I do not want to carry forward for too long if I can avoid it. In short, I do need a version of "move instruction" (or handleMove) that would produce accurate global liveness after its use. If LIS.beginChanges(); // change // LIS.endChanges(); will work as fast and efficiently, no problem then, but I have this feeling that incremental liveness update (when possible) will be easier and cheaper than full scan. You have asked me before - when we are going to upstream the code that does the global code motion - I can tell now that we...