Benchmark with haskell num ops via mutable vectorsexper-hs-numops

Conclusions:
- orthotope zipWith (+) -> zipWithT: 26.9 ms ± 1.6 ms
- Data.Vector.Storable.zipWith (+): 10.1 ms ± 945 μs
- hsaddDoubleVV (this commit): 1.52 ms ± 49 μs
- cbits/arith.c: 1.29 ms ± 116 μs
- hmatrix: 1.25 ms ± 49 μs

1 files changed, 21 insertions, 2 deletions

diff --git a/src/Data/Array/Nested/Internal/Arith.hs b/src/Data/Array/Nested/Internal/Arith.hs
index 07d5d8a..042c9d0 100644
--- a/src/Data/Array/Nested/Internal/Arith.hs
+++ b/src/Data/Array/Nested/Internal/Arith.hs
@@ -6,9 +6,10 @@
 {-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE ViewPatterns #-}
 {-# OPTIONS_GHC -fplugin GHC.TypeLits.KnownNat.Solver #-}
+-- {-# OPTIONS_GHC -ddump-simpl -ddump-to-file -ddump-file-prefix=Arith #-}
 module Data.Array.Nested.Internal.Arith where
 
-import Control.Monad (forM, guard)
+import Control.Monad (forM, forM_, guard)
 import qualified Data.Array.Internal as OI
 import qualified Data.Array.Internal.RankedG as RG
 import qualified Data.Array.Internal.RankedS as RS
@@ -309,8 +310,26 @@ instance NumElt Float where
   numEltSum1Inner = sum1VectorFloat
   numEltProduct1Inner = product1VectorFloat
 
+hsaddDoubleSV :: Double -> VS.Vector Double -> VS.Vector Double
+hsaddDoubleSV = error "unimplemented"
+
+{-# NOINLINE hsaddDoubleVV #-}
+hsaddDoubleVV :: VS.Vector Double -> VS.Vector Double -> VS.Vector Double
+-- hsaddDoubleVV = VS.zipWith (+)
+hsaddDoubleVV v1 v2 = unsafePerformIO $ do
+  let n = min (VS.length v1) (VS.length v2)
+  dest <- VSM.unsafeNew n
+  forM_ [0 .. n - 1] $ \i -> do
+    VSM.write dest i (v1 VS.! i + v2 VS.! i)
+  VS.unsafeFreeze dest
+
 instance NumElt Double where
-  numEltAdd = addVectorDouble
+  numEltAdd = \sn -> liftVEltwise2 sn $ \cases
+    (Left x) (Left y) -> VS.singleton (x + y)
+    (Left x) (Right vy) -> hsaddDoubleSV x vy
+    (Right vx) (Left y) -> hsaddDoubleSV y vx
+    (Right vx) (Right vy) -> hsaddDoubleVV vx vy
+  -- numEltAdd = addVectorDouble
   numEltSub = subVectorDouble
   numEltMul = mulVectorDouble
   numEltNeg = negVectorDouble