[PATCH] D59722: [ScheduleDAG] Avoid unnecessary recomputation of topological order.

Sun May 31 03:11:49 PDT 2020

fhahn added a comment.

In D59722#1451350 <https://reviews.llvm.org/D59722#1451350>, @fhahn wrote:

> After a bit more benchmarking, I think this patch makes things slightly worse in the general case. I've put up a patch that updates ScheduleDAGRRList to update the topological order on demand, D60125 <https://reviews.llvm.org/D60125>, which gives small, but stable improvements on CTMark. I have to revisit this patch and see how we can deal with extreme cases, without making things worse in the general case.

Just benchmark again, it looks like currently there are a few clear improvements and no real regressions: http://llvm-compile-time-tracker.com/compare.php?from=7873376bb36b4f9646fbc26d6da88e2edbf796e4&to=d44cb1460dd6ccad74ea96ce295d804f9e291bf3&stat=instructions

I'll land the patch shortly.

Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D59722/new/

https://reviews.llvm.org/D59722