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{-# LANGUAGE BangPatterns, 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
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 #)
|
