Proposal: Performance improvements for Data.Set
Following on from ticket #4277 here is a similar patch for Data.Set.
This proposal provides a patch that improves performance for many parts of the API. Three standard techniques are applied to the code:
* Worker/Wrapper transformations of recursive functions with constant arguments (aka. the static argument transformation).
* Explicit inlining of wrapper functions.
* Explicit strictness of keys to functions.
Three complementary, but orthogonal patches are provided.
* Add a testsuite, with coverage data (currently 51% of top level functions, and all core functions).
* Add a micro-benchmark suite based on Criterion, for empirical evidence of improvements to each function.
* The optimization patch itself.
All 3 patches should be applied, under this proposal.
The benchmark results are relatively clear:
32% faster on OS X 10.5.8 on 2 GHz Core 2 Duo
The consideration period is 3 weeks (before ICFP).
Work carried out over 28/29th August, 2010 in Utrecht, NL, by Johan Tibell and Don Stewart.