On Wed, 19 Jul 2017, Jan Hubicka wrote: > > On Wed, 19 Jul 2017, Jan Hubicka wrote: > > > > > > > I think we could just output from generic code - I think it can be > > > > > done by > > > > > final_scan_insn. I don't know however if we have a way to tell if the > > > > > section > > > > > starts with a landing pad? > > > > > > > > Not sure either -- some insn note / bb note? Some flag on the label? > > > > At least the latter should be easy to add if it's not there already. > > > > > > > > Richard. > > > > > > Hi, > > > this is updated patch. I am now adding NOP_EXPR into the instruction > > > stream. > > > This is done before shorten branches so alignment tracking works there as > > > expected. > > > Landing pads are having PRESERVE flag set, but that is also true about > > > named > > > labels etc. So I think only safe way is to look them up from the EH > > > tables > > > which is not that hard. first_in_partition is now called on every landing > > > pad in the cold section and it walks backward looking if it can be first. > > > I added > > > visited set to be sure it runs in linear time. > > > > > > Boostrapped/regtested x86_64-linux, OK? > > > > It looks sensible. You leak the hash_set and I wonder if you can hook > > Hmm, isn't the hash_set supposed to destruct itself at the end of scope?
Hmm, you are probably right ;) > > it in pass_convert_to_eh_region_ranges instead which runs before > > rest_of_handle_shorten_branches which means things can be entirely > > contained in except.c? > > Yep, that is a good idea. I did not look into pass.def, just searched > for convenient place to do it before branch relaxation (it probably ought > to run after mdep reorg because no one knows what those will do with the > nop :) > > Will re-test updated patch and commit. Thanks a lot! Did you see the inline comments? Thanks, Richard.
