diff options
Diffstat (limited to 'third_party/bazel/rules_haskell/examples/vector/benchmarks/Algo/Leaffix.hs')
-rw-r--r-- | third_party/bazel/rules_haskell/examples/vector/benchmarks/Algo/Leaffix.hs | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/third_party/bazel/rules_haskell/examples/vector/benchmarks/Algo/Leaffix.hs b/third_party/bazel/rules_haskell/examples/vector/benchmarks/Algo/Leaffix.hs new file mode 100644 index 000000000000..40ec517556fe --- /dev/null +++ b/third_party/bazel/rules_haskell/examples/vector/benchmarks/Algo/Leaffix.hs @@ -0,0 +1,16 @@ +module Algo.Leaffix where + +import Data.Vector.Unboxed as V + +leaffix :: (Vector Int, Vector Int) -> Vector Int +{-# NOINLINE leaffix #-} +leaffix (ls,rs) + = leaffix (V.replicate (V.length ls) 1) ls rs + where + leaffix xs ls rs + = let zs = V.replicate (V.length ls * 2) 0 + vs = V.update_ zs ls xs + sums = V.prescanl' (+) 0 vs + in + V.zipWith (-) (V.backpermute sums ls) (V.backpermute sums rs) + |