cmm/Hoopl/Dataflow: remove unused code
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Authored by michalt on Oct 18 2016, 1:59 PM.

Details

Summary

We had *a lot* of code copied from Hoopl that is for rewriting. But
GHC doesn't use it (it only uses some forked Hoopl code for analysis).

So we can safely kill all this code and make it much easier to
refactor and improve the parts that we do use.

Signed-off-by: Michal Terepeta <michal.terepeta@gmail.com>

Test Plan

./validate

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rGHC Glasgow Haskell Compiler
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michalt updated this revision to Diff 9060.Oct 18 2016, 1:59 PM
michalt retitled this revision from to cmm/Hoopl/Dataflow: remove unused code.
michalt updated this object.
michalt edited the test plan for this revision. (Show Details)
bgamari accepted this revision.Oct 18 2016, 7:27 PM
bgamari edited edge metadata.

Yay for code removal!

This revision is now accepted and ready to land.Oct 18 2016, 7:27 PM
This revision was automatically updated to reflect the committed changes.
simonmar edited edge metadata.Oct 19 2016, 7:28 AM

Well ok. The plan was to use this eventually, but I'm not sure it will ever happen.

Well ok. The plan was to use this eventually, but I'm not sure it will ever happen.

So my understanding is that this code was not used because any rewriting based on it was too slow. And that was after you spent some time optimizing it (e.g., forking from upstream Hoopl). So getting the right performance would probably require more invasive changes still..
That's why I went with simply removing it, which makes any subsequent work easier. And if we decide to have a generic framework for rewriting, I'd be happy to help with it.
(Also, most of this code was not touched since 2012..)