[PATCH] [Refactor] Replace RegionPasses by FunctionPasses

[Johannes Doerfert]

Hey Tobias,

I attached 2 lnt reports to this mail. The first (report_region.json)
was created using the current polly/master. The second
(report_function.json) was created with the region->function pass patch.
Note that this patch is not yet at its full capacity, however over the 3
runs I measured I got:

  Performance Regressions  16
  Performance Improvements  159
  Unchanged Tests   817
  Total Tests   992

Where as the execution time changes (only 8 in total) should be jitter.

The point I try to make here is, 3 runs with the region pass manager take

  2:35:27 (3 runs region passes)

but 3 runs with the function pass manager only

  2:07:48 (3 runs function passes)

hence we save ~18% of the lnt time (if I didn't do a stupid math mistake).

To be precise, we save compile time "only" for larger functions with small SCoP
coverage but we do not pay for it in any other case.

Does this convince you that region passes have a bad impact on compile time?

Best regards,

  Johannes

- F413414: report_function.json <http://reviews.llvm.org/F413414>
- F413416: msg-7066-192.dat <http://reviews.llvm.org/F413416>
- F413415: report_region.json <http://reviews.llvm.org/F413415>


http://reviews.llvm.org/D7986

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