[PATCH] D147557: [SCEV] Improve AddRecs' range computation

Wed Apr 5 02:08:44 PDT 2023

nikic requested changes to this revision.
nikic added a comment.
This revision now requires changes to proceed.

This is too expensive in terms of compile-time: http://llvm-compile-time-tracker.com/compare.php?from=712dfec1781db8aa92782b98cac5517db548b7f9&to=2a04edbcecc77f3d80597662a4ba19f521874d62&stat=instructions:u You're probably forcing an extra invalidation cycle here or something.

I'm also not sure whether the overall approach really makes sense. We shouldn't really get more information from the exit value than we already get from the addrec and the BE count. From what I can tell based on the test changes, the primary benefit here seems to be that we now take into account guard information on the addrec start value -- so a possible alternative would be to apply guards to the start value when calculating addrec ranges, or something along those lines?

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D147557/new/

https://reviews.llvm.org/D147557