solver: swap catas with recursion, fuse travs #7519
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
phadej
reviewed
Aug 6, 2021
|
|
||
| go (PChoiceF qpn rdm gr ts) = PChoice qpn rdm gr <$> sequence (W.mapWithKey (goP qpn) ts) | ||
| go (FChoiceF qfn rdm gr b m d ts) = | ||
| go (PChoice qpn rdm gr ts) = PChoice qpn rdm gr <$> sequence (W.mapWithKey (goP qpn) (fmap go ts)) |
There was a problem hiding this comment.
sequence . map seems bad idea. Should we add traverseWithKey to WeightedPSQ (separately)? Maybe it fuses, but I'm somewhat sceptical about that.
There was a problem hiding this comment.
Sure. I take it you don't consider that a blocker for this PR, as its about changing a different thing than this PR currently does. Are you ok with approving this pr as is?
There was a problem hiding this comment.
I can fix it up with traverseWithKey in the follow up #7533
There was a problem hiding this comment.
Added it first, then pushed to this branch.
emilypi
approved these changes
Aug 11, 2021
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
|
@Mergifyio backport 3.6 |
mergify bot
pushed a commit
that referenced
this pull request
Aug 12, 2021
* solver: swap catas with recursion, fuse travs * whoops * add traverseWithKey to cabal-install-solver (#7533) Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com> * replace sequence . mapWithKey with traverseWithKey * more sequence -> traverse * Update Preference.hs fix bad merge * Update Solver.hs Co-authored-by: Gershom Bazerman <[email protected]> Co-authored-by: Emily Pillmore <[email protected]> Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com> (cherry picked from commit 67c440a) # Conflicts: # cabal-install/cabal-install-solver/src/Distribution/Solver/Modular/Preference.hs # cabal-install/cabal-install-solver/src/Distribution/Solver/Modular/Solver.hs
|
Command
|
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This is the last refactor I had in mind to address the general performance issues discussed in #7466
It attains some modest but real improvement (mainly in allocations) from eliminating the intermediate
catacalls in favor of explicit recursion in the solver tree.For
travcalls, rather than eliminate them entirely, it lifts out their intermediate functions to the top level and explicitly fuses them in the solver pipeline, which yields somewhat more significant improvements.Overall not the huge win I hoped, but nonetheless given the straightforward nature of the changes to the code, still worth it I think.