[LLVMdev] RFC: Exception Handling Rewrite

[Bill Wendling]

On Jul 23, 2011, at 5:00 PM, Jakob Stoklund Olesen wrote:

> It would certainly make many things easier, but I don't think we properly understand the code size impact of doing that. Low-frequency blocks without critical edges are like catnip to the splitter. It will put all the spill code in there, and we may not be able to merge those landing pads again.
> 
> I would like to keep the option, but I don't think we should aggressively duplicate landing pads.
> 
> I want to be able to split and duplicate landing pads on demand in IR and in MI. That is just as good as splitting critical edges. It sounds like your proposal allows this. We can discuss the MI representation when the time comes.
> 
It should be possible to manually break the critical edges, split the landing pad, dup the landingpad instruction, etc. So yes, this is a happy medium. Sorry for the initial confusion. :-)

-bw