[PATCH] D21405: [PGO] IRPGO pre-cleanup pass changes

[Mehdi AMINI via llvm-commits]

mehdi_amini added a comment.

In https://reviews.llvm.org/D21405#501428, @chandlerc wrote:

> I would be much more in favor of a design which instead of changing the pipeline to optimize differently (and thus having PGO vs. normal divergence) either:
>
> - Teaches the instrumentation pass to do the necessary (possibly interprocedural) analysis to instrument only in places it will be cheap, or
> - Teach the existing pipeline to actually optimize and transform the instrumentation code to remove the overhead as necessary.


I totally agree that this would be much better, however there is something that was mentioned that I don't know how to address: the counters can get actually more precise due to the split context after inlining.


Repository:
  rL LLVM

https://reviews.llvm.org/D21405