Memory allocation benchmark

bench.hs

import Control.Exception
import Data.Functor (void)
import Foreign hiding (void)

import Criterion.Main

main :: IO ()
main = defaultMain
  [ bench "alloca" $ nfIO benchAlloca
  , bench "malloc" $ nfIO benchMalloc
  , bench "malloc/free" $ nfIO benchMallocFree
  , bench "mallocForeignPtr" $ nfIO benchMallocForeignPtr
  , bench "mallocForeignPtr/touchForeignPtr" $ nfIO benchMallocForeignPtrTouch
  ]

benchAlloca :: IO ()
benchAlloca = allocaBytes 16 $ \_ -> return ()

benchMalloc :: IO ()
benchMalloc = void $ mallocBytes 16

benchMallocFree :: IO ()
benchMallocFree = do
  ptr <- mallocBytes 16
  free ptr

benchMallocForeignPtr :: IO ()
benchMallocForeignPtr =
  void $ mallocForeignPtrBytes 16

benchMallocForeignPtrTouch :: IO ()
benchMallocForeignPtrTouch =
  bracket (mallocForeignPtrBytes 16) touchForeignPtr $ \_ -> return ()

{-
% ./bench -o bench.html --resamples 10000
benchmarking alloca
time                 6.601 ns   (6.523 ns .. 6.683 ns)
                     0.999 R²   (0.997 R² .. 0.999 R²)
mean                 6.608 ns   (6.525 ns .. 6.725 ns)
std dev              322.5 ps   (242.6 ps .. 482.4 ps)
variance introduced by outliers: 74% (severely inflated)

benchmarking malloc
time                 33.21 ns   (33.04 ns .. 33.40 ns)
                     1.000 R²   (0.999 R² .. 1.000 R²)
mean                 33.36 ns   (33.15 ns .. 33.66 ns)
std dev              828.6 ps   (620.8 ps .. 1.119 ns)
variance introduced by outliers: 39% (moderately inflated)

benchmarking malloc/free
time                 46.04 ns   (45.44 ns .. 46.76 ns)
                     0.999 R²   (0.998 R² .. 0.999 R²)
mean                 46.74 ns   (46.17 ns .. 47.56 ns)
std dev              2.298 ns   (1.632 ns .. 3.287 ns)
variance introduced by outliers: 71% (severely inflated)

benchmarking mallocForeignPtr
time                 8.438 ns   (8.388 ns .. 8.497 ns)
                     0.999 R²   (0.999 R² .. 1.000 R²)
mean                 8.532 ns   (8.436 ns .. 8.677 ns)
std dev              395.6 ps   (275.2 ps .. 516.3 ps)
variance introduced by outliers: 71% (severely inflated)

benchmarking mallocForeignPtr/touchForeignPtr
time                 24.11 ns   (23.87 ns .. 24.34 ns)
                     0.999 R²   (0.998 R² .. 1.000 R²)
mean                 24.23 ns   (23.96 ns .. 24.75 ns)
std dev              1.216 ns   (724.6 ps .. 1.967 ns)
variance introduced by outliers: 73% (severely inflated)
-}