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| author | David Feuer <David.Feuer@gmail.com> | 2014-10-01 15:57:27 +0200 |
|---|---|---|
| committer | Joachim Breitner <mail@joachim-breitner.de> | 2014-10-01 18:20:26 +0200 |
| commit | 789321098f86fd3c4483b24372f8938f89b12312 (patch) | |
| tree | 6ca281bb51fda372bbedc281c73c749ecd947272 | |
| parent | d41dd03fdf0ef723ca31f5a11f07a54a15d2cbc0 (diff) | |
| download | haskell-789321098f86fd3c4483b24372f8938f89b12312.tar.gz | |
Fusion rule for "foldr k z (x:build g)"
There seem to be various issues with general fold/cons and even
cons/build rules, but it seems pretty clear to me that the simple
fold/cons/build rule is a good idea. It doesn't do much for nofib
allocation, but it seems to improve some other analyses and speed
several benchmarks up. Implements #9536.
| -rw-r--r-- | libraries/base/GHC/Base.lhs | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/libraries/base/GHC/Base.lhs b/libraries/base/GHC/Base.lhs index 8b51c07645..f9d01b5269 100644 --- a/libraries/base/GHC/Base.lhs +++ b/libraries/base/GHC/Base.lhs @@ -788,6 +788,9 @@ augment g xs = g (:) xs "foldr/single" forall k z x. foldr k z [x] = k x z "foldr/nil" forall k z. foldr k z [] = z +"foldr/cons/build" forall k z x (g::forall b. (a->b->b) -> b -> b) . + foldr k z (x:build g) = k x (g k z) + "augment/build" forall (g::forall b. (a->b->b) -> b -> b) (h::forall b. (a->b->b) -> b -> b) . augment g (build h) = build (\c n -> g c (h c n)) |