[PATCH] D152577: Part 2 of Fine tune MachineFunctionSplitPass (MFS) for FSAFDO.

[Rong Xu via Phabricator via llvm-commits]

xur added inline comments.


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Comment at: llvm/lib/CodeGen/TargetPassConfig.cpp:1228
 
-  if (EnableFSDiscriminator && !FSNoFinalDiscrim)
-    // Add FS discriminators here so that all the instruction duplicates
----------------
wenlei wrote:
> Is this `FSNoFinalDiscrim` cl flag still used anywhere? Remove `fs-no-final-discrim` to cleanup?
Good catch. I don't think there is a use for the var. We should remove that option.


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Comment at: llvm/lib/CodeGen/TargetPassConfig.cpp:1280
+        // enabled, this may result in performance degradation.
+        report_fatal_error("Must use AutoFDO with FSDiscriminator for MFS.");
+      }
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wenlei wrote:
> hoy wrote:
> > A fatal error seems too strong to me. Can we do a warning instead so that we can still experiment with non-FS AutoFDO profile?
> Agree. There is no correctness issue, and sub-optimal performance doesn't justify a fatal.  
I'm fine with a warning too.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D152577/new/

https://reviews.llvm.org/D152577