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{-# LANGUAGE BangPatterns, MagicHash, UnboxedTuples #-}
{-# OPTIONS_GHC -O #-}
-- 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 FastMutInt(
FastMutInt, newFastMutInt,
readFastMutInt, writeFastMutInt,
FastMutPtr, newFastMutPtr,
readFastMutPtr, writeFastMutPtr
) where
import Data.Bits
import GHC.Base
import GHC.Ptr
newFastMutInt :: IO FastMutInt
readFastMutInt :: FastMutInt -> IO Int
writeFastMutInt :: FastMutInt -> Int -> IO ()
newFastMutPtr :: IO FastMutPtr
readFastMutPtr :: FastMutPtr -> IO (Ptr a)
writeFastMutPtr :: FastMutPtr -> Ptr a -> IO ()
data FastMutInt = FastMutInt (MutableByteArray# RealWorld)
newFastMutInt = IO $ \s ->
case newByteArray# size s of { (# s, arr #) ->
(# s, FastMutInt arr #) }
where !(I# size) = finiteBitSize (0 :: Int)
readFastMutInt (FastMutInt arr) = IO $ \s ->
case readIntArray# arr 0# s of { (# s, i #) ->
(# s, I# i #) }
writeFastMutInt (FastMutInt arr) (I# i) = IO $ \s ->
case writeIntArray# arr 0# i s of { s ->
(# s, () #) }
data FastMutPtr = FastMutPtr (MutableByteArray# RealWorld)
newFastMutPtr = IO $ \s ->
case newByteArray# size s of { (# s, arr #) ->
(# s, FastMutPtr arr #) }
-- GHC assumes 'sizeof (Int) == sizeof (Ptr a)'
where !(I# size) = finiteBitSize (0 :: Int)
readFastMutPtr (FastMutPtr arr) = IO $ \s ->
case readAddrArray# arr 0# s of { (# s, i #) ->
(# s, Ptr i #) }
writeFastMutPtr (FastMutPtr arr) (Ptr i) = IO $ \s ->
case writeAddrArray# arr 0# i s of { s ->
(# s, () #) }
|
