File: FastMutInt.hs

package info (click to toggle)
ghc 9.10.3-3
  • links: PTS, VCS
  • area: main
  • in suites: sid
  • size: 169,076 kB
  • sloc: haskell: 713,554; ansic: 84,184; cpp: 30,255; javascript: 9,003; sh: 7,870; fortran: 3,527; python: 3,228; asm: 2,523; makefile: 2,324; yacc: 1,570; lisp: 532; xml: 196; perl: 111; csh: 2
file content (46 lines) | stat: -rw-r--r-- 1,268 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
{-# LANGUAGE MagicHash, UnboxedTuples #-}
{-# OPTIONS_GHC -O2 #-}
-- We always optimise this, otherwise performance of a non-optimised
-- compiler is severely affected
--
-- (c) The University of Glasgow 2002-2006
--
-- Unboxed mutable Ints

module GHC.Data.FastMutInt(
        FastMutInt, newFastMutInt,
        readFastMutInt, writeFastMutInt,
        atomicFetchAddFastMut
  ) where

import GHC.Prelude.Basic

import GHC.Base

data FastMutInt = FastMutInt !(MutableByteArray# RealWorld)

newFastMutInt :: Int -> IO FastMutInt
newFastMutInt n = do
    x <- create
    writeFastMutInt x n
    return x
  where
    !(I# size) = finiteBitSize (0 :: Int) `unsafeShiftR` 3
    create = IO $ \s ->
      case newByteArray# size s of
        (# s, arr #) -> (# s, FastMutInt arr #)

readFastMutInt :: FastMutInt -> IO Int
readFastMutInt (FastMutInt arr) = IO $ \s ->
  case readIntArray# arr 0# s of
    (# s, i #) -> (# s, I# i #)

writeFastMutInt :: FastMutInt -> Int -> IO ()
writeFastMutInt (FastMutInt arr) (I# i) = IO $ \s ->
  case writeIntArray# arr 0# i s of
    s -> (# s, () #)

atomicFetchAddFastMut :: FastMutInt -> Int -> IO Int
atomicFetchAddFastMut (FastMutInt arr) (I# i) = IO $ \s ->
  case fetchAddIntArray# arr 0# i s of
    (# s, n #) -> (# s, I# n #)