[PATCH] D63626: [clang][NewPM] Remove exception handling before loading pgo sample profile data

Thu Jun 20 19:39:16 PDT 2019

chandlerc added reviewers: davidxl, tejohnson.
chandlerc added a comment.

See inline comment, but I think we should just drop the testing of the function attribute bit here rather than adjusting the pipeline.

================
Comment at: llvm/lib/Passes/PassBuilder.cpp:665-668
+    // We must also remove exception handling before attaching sample profile
+    // data.
+    MPM.addPass(
+        createModuleToPostOrderCGSCCPassAdaptor(PostOrderFunctionAttrsPass()));
----------------
Does the this need to go before the EarlyFPM as well as before the sample profile loader?

Also, this is ... a pretty expensive thing to do... Do we really need this? We've been using ThinLTO and sample PGO with the new PM for a long time and haven't seen any real issue. I think we can probably just leave this difference between the two pass managers and remove the test for this pass running rather than adding it.

CC-ing some others just to double check, but I'm not aware of any issues we've seen with PGO that were because of this discrepancy.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D63626/new/

https://reviews.llvm.org/D63626