    {-# LANGUAGE Trustworthy #-}
    {-# LANGUAGE CPP, NoImplicitPrelude, BangPatterns, MagicHash, UnboxedTuples #-}
    {-# OPTIONS_HADDOCK hide #-}

    -----------------------------------------------------------------------------
    -- |
    -- Module      :  GHC.Word
    -- Copyright   :  (c) The University of Glasgow, 1997-2002
    -- License     :  see libraries/base/LICENSE
    --
    -- Maintainer  :  cvs-ghc@haskell.org
    -- Stability   :  internal
    -- Portability :  non-portable (GHC Extensions)
    --
    -- Sized unsigned integral types: 'Word', 'Word8', 'Word16', 'Word32', and
    -- 'Word64'.
    --
    -----------------------------------------------------------------------------

    #include "MachDeps.h"

    module GHC.Word (
        Word(..), Word8(..), Word16(..), Word32(..), Word64(..),
        uncheckedShiftL64#,
        uncheckedShiftRL64#,
        byteSwap16,
        byteSwap32,
        byteSwap64
        ) where

    import Data.Bits
    import Data.Maybe

    #if WORD_SIZE_IN_BITS < 64
    import GHC.IntWord64
    #endif

    import GHC.Base
    import GHC.Enum
    import GHC.Num
    import GHC.Real
    import GHC.Read
    import GHC.Arr
    import GHC.Show

    ------------------------------------------------------------------------
    -- type Word8
    ------------------------------------------------------------------------

    -- Word8 is represented in the same way as Word. Operations may assume
    -- and must ensure that it holds only values from its logical range.

    data {-# CTYPE "HsWord8" #-} Word8 = W8# Word# deriving (Eq, Ord)
    -- ^ 8-bit unsigned integer type

    instance Show Word8 where
        showsPrec p x = showsPrec p (fromIntegral x :: Int)

    instance Num Word8 where
        (W8# x#) + (W8# y#)    = W8# (narrow8Word# (x# `plusWord#` y#))
        (W8# x#) - (W8# y#)    = W8# (narrow8Word# (x# `minusWord#` y#))
        (W8# x#) * (W8# y#)    = W8# (narrow8Word# (x# `timesWord#` y#))
        negate (W8# x#)        = W8# (narrow8Word# (int2Word# (negateInt# (word2Int# x#))))
        abs x                  = x
        signum 0               = 0
        signum _               = 1
        fromInteger i          = W8# (narrow8Word# (integerToWord i))

    instance Real Word8 where
        toRational x = toInteger x % 1

    instance Enum Word8 where
        succ x
            | x /= maxBound = x + 1
            | otherwise     = succError "Word8"
        pred x
            | x /= minBound = x - 1
            | otherwise     = predError "Word8"
        toEnum i@(I# i#)
            | i >= 0 && i <= fromIntegral (maxBound::Word8)
                            = W8# (int2Word# i#)
            | otherwise     = toEnumError "Word8" i (minBound::Word8, maxBound::Word8)
        fromEnum (W8# x#)   = I# (word2Int# x#)
        enumFrom            = boundedEnumFrom
        enumFromThen        = boundedEnumFromThen

    instance Integral Word8 where
        quot    (W8# x#) y@(W8# y#)
            | y /= 0                  = W8# (x# `quotWord#` y#)
            | otherwise               = divZeroError
        rem     (W8# x#) y@(W8# y#)
            | y /= 0                  = W8# (x# `remWord#` y#)
            | otherwise               = divZeroError
        div     (W8# x#) y@(W8# y#)
            | y /= 0                  = W8# (x# `quotWord#` y#)
            | otherwise               = divZeroError
        mod     (W8# x#) y@(W8# y#)
            | y /= 0                  = W8# (x# `remWord#` y#)
            | otherwise               = divZeroError
        quotRem (W8# x#) y@(W8# y#)
            | y /= 0                  = case x# `quotRemWord#` y# of
                                        (# q, r #) ->
                                            (W8# q, W8# r)
            | otherwise               = divZeroError
        divMod  (W8# x#) y@(W8# y#)
            | y /= 0                  = (W8# (x# `quotWord#` y#), W8# (x# `remWord#` y#))
            | otherwise               = divZeroError
        toInteger (W8# x#)            = smallInteger (word2Int# x#)

    instance Bounded Word8 where
        minBound = 0
        maxBound = 0xFF

    instance Ix Word8 where
        range (m,n)         = [m..n]
        unsafeIndex (m,_) i = fromIntegral (i - m)
        inRange (m,n) i     = m <= i && i <= n

    instance Read Word8 where
        readsPrec p s = [(fromIntegral (x::Int), r) | (x, r) <- readsPrec p s]

    instance Bits Word8 where
        {-# INLINE shift #-}
        {-# INLINE bit #-}
        {-# INLINE testBit #-}

        (W8# x#) .&.   (W8# y#)   = W8# (x# `and#` y#)
        (W8# x#) .|.   (W8# y#)   = W8# (x# `or#`  y#)
        (W8# x#) `xor` (W8# y#)   = W8# (x# `xor#` y#)
        complement (W8# x#)       = W8# (x# `xor#` mb#)
            where !(W8# mb#) = maxBound
        (W8# x#) `shift` (I# i#)
            | isTrue# (i# >=# 0#) = W8# (narrow8Word# (x# `shiftL#` i#))
            | otherwise           = W8# (x# `shiftRL#` negateInt# i#)
        (W8# x#) `shiftL`       (I# i#) = W8# (narrow8Word# (x# `shiftL#` i#))
        (W8# x#) `unsafeShiftL` (I# i#) =
            W8# (narrow8Word# (x# `uncheckedShiftL#` i#))
        (W8# x#) `shiftR`       (I# i#) = W8# (x# `shiftRL#` i#)
        (W8# x#) `unsafeShiftR` (I# i#) = W8# (x# `uncheckedShiftRL#` i#)
        (W8# x#) `rotate`       (I# i#)
            | isTrue# (i'# ==# 0#) = W8# x#
            | otherwise  = W8# (narrow8Word# ((x# `uncheckedShiftL#` i'#) `or#`
                                              (x# `uncheckedShiftRL#` (8# -# i'#))))
            where
            !i'# = word2Int# (int2Word# i# `and#` 7##)
        bitSizeMaybe i            = Just (finiteBitSize i)
        bitSize i                 = finiteBitSize i
        isSigned _                = False
        popCount (W8# x#)         = I# (word2Int# (popCnt8# x#))
        bit                       = bitDefault
        testBit                   = testBitDefault

    instance FiniteBits Word8 where
        finiteBitSize _ = 8
        countLeadingZeros  (W8# x#) = I# (word2Int# (clz8# x#))
        countTrailingZeros (W8# x#) = I# (word2Int# (ctz8# x#))

    {-# RULES
    "fromIntegral/Word8->Word8"   fromIntegral = id :: Word8 -> Word8
    "fromIntegral/Word8->Integer" fromIntegral = toInteger :: Word8 -> Integer
    "fromIntegral/a->Word8"       fromIntegral = \x -> case fromIntegral x of W# x# -> W8# (narrow8Word# x#)
    "fromIntegral/Word8->a"       fromIntegral = \(W8# x#) -> fromIntegral (W# x#)
      #-}

    {-# RULES
    "properFraction/Float->(Word8,Float)"
        properFraction = \x ->
                          case properFraction x of {
                            (n, y) -> ((fromIntegral :: Int -> Word8) n, y :: Float) }
    "truncate/Float->Word8"
        truncate = (fromIntegral :: Int -> Word8) . (truncate :: Float -> Int)
    "floor/Float->Word8"
        floor    = (fromIntegral :: Int -> Word8) . (floor :: Float -> Int)
    "ceiling/Float->Word8"
        ceiling  = (fromIntegral :: Int -> Word8) . (ceiling :: Float -> Int)
    "round/Float->Word8"
        round    = (fromIntegral :: Int -> Word8) . (round  :: Float -> Int)
      #-}

    {-# RULES
    "properFraction/Double->(Word8,Double)"
        properFraction = \x ->
                          case properFraction x of {
                            (n, y) -> ((fromIntegral :: Int -> Word8) n, y :: Double) }
    "truncate/Double->Word8"
        truncate = (fromIntegral :: Int -> Word8) . (truncate :: Double -> Int)
    "floor/Double->Word8"
        floor    = (fromIntegral :: Int -> Word8) . (floor :: Double -> Int)
    "ceiling/Double->Word8"
        ceiling  = (fromIntegral :: Int -> Word8) . (ceiling :: Double -> Int)
    "round/Double->Word8"
        round    = (fromIntegral :: Int -> Word8) . (round  :: Double -> Int)
      #-}

    ------------------------------------------------------------------------
    -- type Word16
    ------------------------------------------------------------------------

    -- Word16 is represented in the same way as Word. Operations may assume
    -- and must ensure that it holds only values from its logical range.

    data {-# CTYPE "HsWord16" #-} Word16 = W16# Word# deriving (Eq, Ord)
    -- ^ 16-bit unsigned integer type

    instance Show Word16 where
        showsPrec p x = showsPrec p (fromIntegral x :: Int)

    instance Num Word16 where
        (W16# x#) + (W16# y#)  = W16# (narrow16Word# (x# `plusWord#` y#))
        (W16# x#) - (W16# y#)  = W16# (narrow16Word# (x# `minusWord#` y#))
        (W16# x#) * (W16# y#)  = W16# (narrow16Word# (x# `timesWord#` y#))
        negate (W16# x#)       = W16# (narrow16Word# (int2Word# (negateInt# (word2Int# x#))))
        abs x                  = x
        signum 0               = 0
        signum _               = 1
        fromInteger i          = W16# (narrow16Word# (integerToWord i))

    instance Real Word16 where
        toRational x = toInteger x % 1

    instance Enum Word16 where
        succ x
            | x /= maxBound = x + 1
            | otherwise     = succError "Word16"
        pred x
            | x /= minBound = x - 1
            | otherwise     = predError "Word16"
        toEnum i@(I# i#)
            | i >= 0 && i <= fromIntegral (maxBound::Word16)
                            = W16# (int2Word# i#)
            | otherwise     = toEnumError "Word16" i (minBound::Word16, maxBound::Word16)
        fromEnum (W16# x#)  = I# (word2Int# x#)
        enumFrom            = boundedEnumFrom
        enumFromThen        = boundedEnumFromThen

    instance Integral Word16 where
        quot    (W16# x#) y@(W16# y#)
            | y /= 0                    = W16# (x# `quotWord#` y#)
            | otherwise                 = divZeroError
        rem     (W16# x#) y@(W16# y#)
            | y /= 0                    = W16# (x# `remWord#` y#)
            | otherwise                 = divZeroError
        div     (W16# x#) y@(W16# y#)
            | y /= 0                    = W16# (x# `quotWord#` y#)
            | otherwise                 = divZeroError
        mod     (W16# x#) y@(W16# y#)
            | y /= 0                    = W16# (x# `remWord#` y#)
            | otherwise                 = divZeroError
        quotRem (W16# x#) y@(W16# y#)
            | y /= 0                  = case x# `quotRemWord#` y# of
                                        (# q, r #) ->
                                            (W16# q, W16# r)
            | otherwise                 = divZeroError
        divMod  (W16# x#) y@(W16# y#)
            | y /= 0                    = (W16# (x# `quotWord#` y#), W16# (x# `remWord#` y#))
            | otherwise                 = divZeroError
        toInteger (W16# x#)             = smallInteger (word2Int# x#)

    instance Bounded Word16 where
        minBound = 0
        maxBound = 0xFFFF

    instance Ix Word16 where
        range (m,n)         = [m..n]
        unsafeIndex (m,_) i = fromIntegral (i - m)
        inRange (m,n) i     = m <= i && i <= n

    instance Read Word16 where
        readsPrec p s = [(fromIntegral (x::Int), r) | (x, r) <- readsPrec p s]

    instance Bits Word16 where
        {-# INLINE shift #-}
        {-# INLINE bit #-}
        {-# INLINE testBit #-}

        (W16# x#) .&.   (W16# y#)  = W16# (x# `and#` y#)
        (W16# x#) .|.   (W16# y#)  = W16# (x# `or#`  y#)
        (W16# x#) `xor` (W16# y#)  = W16# (x# `xor#` y#)
        complement (W16# x#)       = W16# (x# `xor#` mb#)
            where !(W16# mb#) = maxBound
        (W16# x#) `shift` (I# i#)
            | isTrue# (i# >=# 0#)  = W16# (narrow16Word# (x# `shiftL#` i#))
            | otherwise            = W16# (x# `shiftRL#` negateInt# i#)
        (W16# x#) `shiftL` (I# i#)       = W16# (narrow16Word# (x# `shiftL#` i#))
        (W16# x#) `unsafeShiftL` (I# i#) =
            W16# (narrow16Word# (x# `uncheckedShiftL#` i#))
        (W16# x#) `shiftR`       (I# i#) = W16# (x# `shiftRL#` i#)
        (W16# x#) `unsafeShiftR` (I# i#) = W16# (x# `uncheckedShiftRL#` i#)
        (W16# x#) `rotate`       (I# i#)
            | isTrue# (i'# ==# 0#) = W16# x#
            | otherwise  = W16# (narrow16Word# ((x# `uncheckedShiftL#` i'#) `or#`
                                                (x# `uncheckedShiftRL#` (16# -# i'#))))
            where
            !i'# = word2Int# (int2Word# i# `and#` 15##)
        bitSizeMaybe i            = Just (finiteBitSize i)
        bitSize i                 = finiteBitSize i
        isSigned _                = False
        popCount (W16# x#)        = I# (word2Int# (popCnt16# x#))
        bit                       = bitDefault
        testBit                   = testBitDefault

    instance FiniteBits Word16 where
        finiteBitSize _ = 16
        countLeadingZeros  (W16# x#) = I# (word2Int# (clz16# x#))
        countTrailingZeros (W16# x#) = I# (word2Int# (ctz16# x#))

    -- | Swap bytes in 'Word16'.
    --
    -- @since 4.7.0.0
    byteSwap16 :: Word16 -> Word16
    byteSwap16 (W16# w#) = W16# (narrow16Word# (byteSwap16# w#))

    {-# RULES
    "fromIntegral/Word8->Word16"   fromIntegral = \(W8# x#) -> W16# x#
    "fromIntegral/Word16->Word16"  fromIntegral = id :: Word16 -> Word16
    "fromIntegral/Word16->Integer" fromIntegral = toInteger :: Word16 -> Integer
    "fromIntegral/a->Word16"       fromIntegral = \x -> case fromIntegral x of W# x# -> W16# (narrow16Word# x#)
    "fromIntegral/Word16->a"       fromIntegral = \(W16# x#) -> fromIntegral (W# x#)
      #-}

    {-# RULES
    "properFraction/Float->(Word16,Float)"
        properFraction = \x ->
                          case properFraction x of {
                            (n, y) -> ((fromIntegral :: Int -> Word16) n, y :: Float) }
    "truncate/Float->Word16"
        truncate = (fromIntegral :: Int -> Word16) . (truncate :: Float -> Int)
    "floor/Float->Word16"
        floor    = (fromIntegral :: Int -> Word16) . (floor :: Float -> Int)
    "ceiling/Float->Word16"
        ceiling  = (fromIntegral :: Int -> Word16) . (ceiling :: Float -> Int)
    "round/Float->Word16"
        round    = (fromIntegral :: Int -> Word16) . (round  :: Float -> Int)
      #-}

    {-# RULES
    "properFraction/Double->(Word16,Double)"
        properFraction = \x ->
                          case properFraction x of {
                            (n, y) -> ((fromIntegral :: Int -> Word16) n, y :: Double) }
    "truncate/Double->Word16"
        truncate = (fromIntegral :: Int -> Word16) . (truncate :: Double -> Int)
    "floor/Double->Word16"
        floor    = (fromIntegral :: Int -> Word16) . (floor :: Double -> Int)
    "ceiling/Double->Word16"
        ceiling  = (fromIntegral :: Int -> Word16) . (ceiling :: Double -> Int)
    "round/Double->Word16"
        round    = (fromIntegral :: Int -> Word16) . (round  :: Double -> Int)
      #-}

    ------------------------------------------------------------------------
    -- type Word32
    ------------------------------------------------------------------------

    -- Word32 is represented in the same way as Word.
    #if WORD_SIZE_IN_BITS > 32
    -- Operations may assume and must ensure that it holds only values
    -- from its logical range.

    -- We can use rewrite rules for the RealFrac methods

    {-# RULES
    "properFraction/Float->(Word32,Float)"
        properFraction = \x ->
                          case properFraction x of {
                            (n, y) -> ((fromIntegral :: Int -> Word32) n, y :: Float) }
    "truncate/Float->Word32"
        truncate = (fromIntegral :: Int -> Word32) . (truncate :: Float -> Int)
    "floor/Float->Word32"
        floor    = (fromIntegral :: Int -> Word32) . (floor :: Float -> Int)
    "ceiling/Float->Word32"
        ceiling  = (fromIntegral :: Int -> Word32) . (ceiling :: Float -> Int)
    "round/Float->Word32"
        round    = (fromIntegral :: Int -> Word32) . (round  :: Float -> Int)
      #-}

    {-# RULES
    "properFraction/Double->(Word32,Double)"
        properFraction = \x ->
                          case properFraction x of {
                            (n, y) -> ((fromIntegral :: Int -> Word32) n, y :: Double) }
    "truncate/Double->Word32"
        truncate = (fromIntegral :: Int -> Word32) . (truncate :: Double -> Int)
    "floor/Double->Word32"
        floor    = (fromIntegral :: Int -> Word32) . (floor :: Double -> Int)
    "ceiling/Double->Word32"
        ceiling  = (fromIntegral :: Int -> Word32) . (ceiling :: Double -> Int)
    "round/Double->Word32"
        round    = (fromIntegral :: Int -> Word32) . (round  :: Double -> Int)
      #-}

    #endif

    data {-# CTYPE "HsWord32" #-} Word32 = W32# Word# deriving (Eq, Ord)
    -- ^ 32-bit unsigned integer type

    instance Num Word32 where
        (W32# x#) + (W32# y#)  = W32# (narrow32Word# (x# `plusWord#` y#))
        (W32# x#) - (W32# y#)  = W32# (narrow32Word# (x# `minusWord#` y#))
        (W32# x#) * (W32# y#)  = W32# (narrow32Word# (x# `timesWord#` y#))
        negate (W32# x#)       = W32# (narrow32Word# (int2Word# (negateInt# (word2Int# x#))))
        abs x                  = x
        signum 0               = 0
        signum _               = 1
        fromInteger i          = W32# (narrow32Word# (integerToWord i))

    instance Enum Word32 where
        succ x
            | x /= maxBound = x + 1
            | otherwise     = succError "Word32"
        pred x
            | x /= minBound = x - 1
            | otherwise     = predError "Word32"
        toEnum i@(I# i#)
            | i >= 0
    #if WORD_SIZE_IN_BITS > 32
              && i <= fromIntegral (maxBound::Word32)
    #endif
                            = W32# (int2Word# i#)
            | otherwise     = toEnumError "Word32" i (minBound::Word32, maxBound::Word32)
    #if WORD_SIZE_IN_BITS == 32
        fromEnum x@(W32# x#)
            | x <= fromIntegral (maxBound::Int)
                            = I# (word2Int# x#)
            | otherwise     = fromEnumError "Word32" x
        enumFrom            = integralEnumFrom
        enumFromThen        = integralEnumFromThen
        enumFromTo          = integralEnumFromTo
        enumFromThenTo      = integralEnumFromThenTo
    #else
        fromEnum (W32# x#)  = I# (word2Int# x#)
        enumFrom            = boundedEnumFrom
        enumFromThen        = boundedEnumFromThen
    #endif

    instance Integral Word32 where
        quot    (W32# x#) y@(W32# y#)
            | y /= 0                    = W32# (x# `quotWord#` y#)
            | otherwise                 = divZeroError
        rem     (W32# x#) y@(W32# y#)
            | y /= 0                    = W32# (x# `remWord#` y#)
            | otherwise                 = divZeroError
        div     (W32# x#) y@(W32# y#)
            | y /= 0                    = W32# (x# `quotWord#` y#)
            | otherwise                 = divZeroError
        mod     (W32# x#) y@(W32# y#)
            | y /= 0                    = W32# (x# `remWord#` y#)
            | otherwise                 = divZeroError
        quotRem (W32# x#) y@(W32# y#)
            | y /= 0                  = case x# `quotRemWord#` y# of
                                        (# q, r #) ->
                                            (W32# q, W32# r)
            | otherwise                 = divZeroError
        divMod  (W32# x#) y@(W32# y#)
            | y /= 0                    = (W32# (x# `quotWord#` y#), W32# (x# `remWord#` y#))
            | otherwise                 = divZeroError
        toInteger (W32# x#)
    #if WORD_SIZE_IN_BITS == 32
            | isTrue# (i# >=# 0#)       = smallInteger i#
            | otherwise                 = wordToInteger x#
            where
            !i# = word2Int# x#
    #else
                                        = smallInteger (word2Int# x#)
    #endif

    instance Bits Word32 where
        {-# INLINE shift #-}
        {-# INLINE bit #-}
        {-# INLINE testBit #-}

        (W32# x#) .&.   (W32# y#)  = W32# (x# `and#` y#)
        (W32# x#) .|.   (W32# y#)  = W32# (x# `or#`  y#)
        (W32# x#) `xor` (W32# y#)  = W32# (x# `xor#` y#)
        complement (W32# x#)       = W32# (x# `xor#` mb#)
            where !(W32# mb#) = maxBound
        (W32# x#) `shift` (I# i#)
            | isTrue# (i# >=# 0#)  = W32# (narrow32Word# (x# `shiftL#` i#))
            | otherwise            = W32# (x# `shiftRL#` negateInt# i#)
        (W32# x#) `shiftL`       (I# i#) = W32# (narrow32Word# (x# `shiftL#` i#))
        (W32# x#) `unsafeShiftL` (I# i#) =
            W32# (narrow32Word# (x# `uncheckedShiftL#` i#))
        (W32# x#) `shiftR`       (I# i#) = W32# (x# `shiftRL#` i#)
        (W32# x#) `unsafeShiftR` (I# i#) = W32# (x# `uncheckedShiftRL#` i#)
        (W32# x#) `rotate`       (I# i#)
            | isTrue# (i'# ==# 0#) = W32# x#
            | otherwise   = W32# (narrow32Word# ((x# `uncheckedShiftL#` i'#) `or#`
                                                (x# `uncheckedShiftRL#` (32# -# i'#))))
            where
            !i'# = word2Int# (int2Word# i# `and#` 31##)
        bitSizeMaybe i            = Just (finiteBitSize i)
        bitSize i                 = finiteBitSize i
        isSigned _                = False
        popCount (W32# x#)        = I# (word2Int# (popCnt32# x#))
        bit                       = bitDefault
        testBit                   = testBitDefault

    instance FiniteBits Word32 where
        finiteBitSize _ = 32
        countLeadingZeros  (W32# x#) = I# (word2Int# (clz32# x#))
        countTrailingZeros (W32# x#) = I# (word2Int# (ctz32# x#))

    {-# RULES
    "fromIntegral/Word8->Word32"   fromIntegral = \(W8# x#) -> W32# x#
    "fromIntegral/Word16->Word32"  fromIntegral = \(W16# x#) -> W32# x#
    "fromIntegral/Word32->Word32"  fromIntegral = id :: Word32 -> Word32
    "fromIntegral/Word32->Integer" fromIntegral = toInteger :: Word32 -> Integer
    "fromIntegral/a->Word32"       fromIntegral = \x -> case fromIntegral x of W# x# -> W32# (narrow32Word# x#)
    "fromIntegral/Word32->a"       fromIntegral = \(W32# x#) -> fromIntegral (W# x#)
      #-}

    instance Show Word32 where
    #if WORD_SIZE_IN_BITS < 33
        showsPrec p x = showsPrec p (toInteger x)
    #else
        showsPrec p x = showsPrec p (fromIntegral x :: Int)
    #endif

    instance Real Word32 where
        toRational x = toInteger x % 1

    instance Bounded Word32 where
        minBound = 0
        maxBound = 0xFFFFFFFF

    instance Ix Word32 where
        range (m,n)         = [m..n]
        unsafeIndex (m,_) i = fromIntegral (i - m)
        inRange (m,n) i     = m <= i && i <= n

    instance Read Word32 where
    #if WORD_SIZE_IN_BITS < 33
        readsPrec p s = [(fromInteger x, r) | (x, r) <- readsPrec p s]
    #else
        readsPrec p s = [(fromIntegral (x::Int), r) | (x, r) <- readsPrec p s]
    #endif

    -- | Reverse order of bytes in 'Word32'.
    --
    -- @since 4.7.0.0
    byteSwap32 :: Word32 -> Word32
    byteSwap32 (W32# w#) = W32# (narrow32Word# (byteSwap32# w#))

    ------------------------------------------------------------------------
    -- type Word64
    ------------------------------------------------------------------------

    #if WORD_SIZE_IN_BITS < 64

    data {-# CTYPE "HsWord64" #-} Word64 = W64# Word64#
    -- ^ 64-bit unsigned integer type

    instance Eq Word64 where
        (W64# x#) == (W64# y#) = isTrue# (x# `eqWord64#` y#)
        (W64# x#) /= (W64# y#) = isTrue# (x# `neWord64#` y#)

    instance Ord Word64 where
        (W64# x#) <  (W64# y#) = isTrue# (x# `ltWord64#` y#)
        (W64# x#) <= (W64# y#) = isTrue# (x# `leWord64#` y#)
        (W64# x#) >  (W64# y#) = isTrue# (x# `gtWord64#` y#)
        (W64# x#) >= (W64# y#) = isTrue# (x# `geWord64#` y#)

    instance Num Word64 where
        (W64# x#) + (W64# y#)  = W64# (int64ToWord64# (word64ToInt64# x# `plusInt64#` word64ToInt64# y#))
        (W64# x#) - (W64# y#)  = W64# (int64ToWord64# (word64ToInt64# x# `minusInt64#` word64ToInt64# y#))
        (W64# x#) * (W64# y#)  = W64# (int64ToWord64# (word64ToInt64# x# `timesInt64#` word64ToInt64# y#))
        negate (W64# x#)       = W64# (int64ToWord64# (negateInt64# (word64ToInt64# x#)))
        abs x                  = x
        signum 0               = 0
        signum _               = 1
        fromInteger i          = W64# (integerToWord64 i)

    instance Enum Word64 where
        succ x
            | x /= maxBound = x + 1
            | otherwise     = succError "Word64"
        pred x
            | x /= minBound = x - 1
            | otherwise     = predError "Word64"
        toEnum i@(I# i#)
            | i >= 0        = W64# (wordToWord64# (int2Word# i#))
            | otherwise     = toEnumError "Word64" i (minBound::Word64, maxBound::Word64)
        fromEnum x@(W64# x#)
            | x <= fromIntegral (maxBound::Int)
                            = I# (word2Int# (word64ToWord# x#))
            | otherwise     = fromEnumError "Word64" x
        enumFrom            = integralEnumFrom
        enumFromThen        = integralEnumFromThen
        enumFromTo          = integralEnumFromTo
        enumFromThenTo      = integralEnumFromThenTo

    instance Integral Word64 where
        quot    (W64# x#) y@(W64# y#)
            | y /= 0                    = W64# (x# `quotWord64#` y#)
            | otherwise                 = divZeroError
        rem     (W64# x#) y@(W64# y#)
            | y /= 0                    = W64# (x# `remWord64#` y#)
            | otherwise                 = divZeroError
        div     (W64# x#) y@(W64# y#)
            | y /= 0                    = W64# (x# `quotWord64#` y#)
            | otherwise                 = divZeroError
        mod     (W64# x#) y@(W64# y#)
            | y /= 0                    = W64# (x# `remWord64#` y#)
            | otherwise                 = divZeroError
        quotRem (W64# x#) y@(W64# y#)
            | y /= 0                    = (W64# (x# `quotWord64#` y#), W64# (x# `remWord64#` y#))
            | otherwise                 = divZeroError
        divMod  (W64# x#) y@(W64# y#)
            | y /= 0                    = (W64# (x# `quotWord64#` y#), W64# (x# `remWord64#` y#))
            | otherwise                 = divZeroError
        toInteger (W64# x#)             = word64ToInteger x#

    instance Bits Word64 where
        {-# INLINE shift #-}
        {-# INLINE bit #-}
        {-# INLINE testBit #-}

        (W64# x#) .&.   (W64# y#)  = W64# (x# `and64#` y#)
        (W64# x#) .|.   (W64# y#)  = W64# (x# `or64#`  y#)
        (W64# x#) `xor` (W64# y#)  = W64# (x# `xor64#` y#)
        complement (W64# x#)       = W64# (not64# x#)
        (W64# x#) `shift` (I# i#)
            | isTrue# (i# >=# 0#)  = W64# (x# `shiftL64#` i#)
            | otherwise            = W64# (x# `shiftRL64#` negateInt# i#)
        (W64# x#) `shiftL`       (I# i#) = W64# (x# `shiftL64#` i#)
        (W64# x#) `unsafeShiftL` (I# i#) = W64# (x# `uncheckedShiftL64#` i#)
        (W64# x#) `shiftR`       (I# i#) = W64# (x# `shiftRL64#` i#)
        (W64# x#) `unsafeShiftR` (I# i#) = W64# (x# `uncheckedShiftRL64#` i#)
        (W64# x#) `rotate` (I# i#)
            | isTrue# (i'# ==# 0#) = W64# x#
            | otherwise            = W64# ((x# `uncheckedShiftL64#` i'#) `or64#`
                                           (x# `uncheckedShiftRL64#` (64# -# i'#)))
            where
            !i'# = word2Int# (int2Word# i# `and#` 63##)
        bitSizeMaybe i            = Just (finiteBitSize i)
        bitSize i                 = finiteBitSize i
        isSigned _                = False
        popCount (W64# x#)        = I# (word2Int# (popCnt64# x#))
        bit                       = bitDefault
        testBit                   = testBitDefault

    -- give the 64-bit shift operations the same treatment as the 32-bit
    -- ones (see GHC.Base), namely we wrap them in tests to catch the
    -- cases when we're shifting more than 64 bits to avoid unspecified
    -- behaviour in the C shift operations.

    shiftL64#, shiftRL64# :: Word64# -> Int# -> Word64#

    a `shiftL64#` b  | isTrue# (b >=# 64#) = wordToWord64# 0##
                     | otherwise           = a `uncheckedShiftL64#` b

    a `shiftRL64#` b | isTrue# (b >=# 64#) = wordToWord64# 0##
                     | otherwise           = a `uncheckedShiftRL64#` b

    {-# RULES
    "fromIntegral/Int->Word64"    fromIntegral = \(I#   x#) -> W64# (int64ToWord64# (intToInt64# x#))
    "fromIntegral/Word->Word64"   fromIntegral = \(W#   x#) -> W64# (wordToWord64# x#)
    "fromIntegral/Word64->Int"    fromIntegral = \(W64# x#) -> I#   (word2Int# (word64ToWord# x#))
    "fromIntegral/Word64->Word"   fromIntegral = \(W64# x#) -> W#   (word64ToWord# x#)
    "fromIntegral/Word64->Word64" fromIntegral = id :: Word64 -> Word64
      #-}

    #else

    -- Word64 is represented in the same way as Word.
    -- Operations may assume and must ensure that it holds only values
    -- from its logical range.

    data {-# CTYPE "HsWord64" #-} Word64 = W64# Word# deriving (Eq, Ord)
    -- ^ 64-bit unsigned integer type

    instance Num Word64 where
        (W64# x#) + (W64# y#)  = W64# (x# `plusWord#` y#)
        (W64# x#) - (W64# y#)  = W64# (x# `minusWord#` y#)
        (W64# x#) * (W64# y#)  = W64# (x# `timesWord#` y#)
        negate (W64# x#)       = W64# (int2Word# (negateInt# (word2Int# x#)))
        abs x                  = x
        signum 0               = 0
        signum _               = 1
        fromInteger i          = W64# (integerToWord i)

    instance Enum Word64 where
        succ x
            | x /= maxBound = x + 1
            | otherwise     = succError "Word64"
        pred x
            | x /= minBound = x - 1
            | otherwise     = predError "Word64"
        toEnum i@(I# i#)
            | i >= 0        = W64# (int2Word# i#)
            | otherwise     = toEnumError "Word64" i (minBound::Word64, maxBound::Word64)
        fromEnum x@(W64# x#)
            | x <= fromIntegral (maxBound::Int)
                            = I# (word2Int# x#)
            | otherwise     = fromEnumError "Word64" x
        enumFrom            = integralEnumFrom
        enumFromThen        = integralEnumFromThen
        enumFromTo          = integralEnumFromTo
        enumFromThenTo      = integralEnumFromThenTo

    instance Integral Word64 where
        quot    (W64# x#) y@(W64# y#)
            | y /= 0                    = W64# (x# `quotWord#` y#)
            | otherwise                 = divZeroError
        rem     (W64# x#) y@(W64# y#)
            | y /= 0                    = W64# (x# `remWord#` y#)
            | otherwise                 = divZeroError
        div     (W64# x#) y@(W64# y#)
            | y /= 0                    = W64# (x# `quotWord#` y#)
            | otherwise                 = divZeroError
        mod     (W64# x#) y@(W64# y#)
            | y /= 0                    = W64# (x# `remWord#` y#)
            | otherwise                 = divZeroError
        quotRem (W64# x#) y@(W64# y#)
            | y /= 0                  = case x# `quotRemWord#` y# of
                                        (# q, r #) ->
                                            (W64# q, W64# r)
            | otherwise                 = divZeroError
        divMod  (W64# x#) y@(W64# y#)
            | y /= 0                    = (W64# (x# `quotWord#` y#), W64# (x# `remWord#` y#))
            | otherwise                 = divZeroError
        toInteger (W64# x#)
            | isTrue# (i# >=# 0#)       = smallInteger i#
            | otherwise                 = wordToInteger x#
            where
            !i# = word2Int# x#

    instance Bits Word64 where
        {-# INLINE shift #-}
        {-# INLINE bit #-}
        {-# INLINE testBit #-}

        (W64# x#) .&.   (W64# y#)  = W64# (x# `and#` y#)
        (W64# x#) .|.   (W64# y#)  = W64# (x# `or#`  y#)
        (W64# x#) `xor` (W64# y#)  = W64# (x# `xor#` y#)
        complement (W64# x#)       = W64# (x# `xor#` mb#)
            where !(W64# mb#) = maxBound
        (W64# x#) `shift` (I# i#)
            | isTrue# (i# >=# 0#)  = W64# (x# `shiftL#` i#)
            | otherwise            = W64# (x# `shiftRL#` negateInt# i#)
        (W64# x#) `shiftL`       (I# i#) = W64# (x# `shiftL#` i#)
        (W64# x#) `unsafeShiftL` (I# i#) = W64# (x# `uncheckedShiftL#` i#)
        (W64# x#) `shiftR`       (I# i#) = W64# (x# `shiftRL#` i#)
        (W64# x#) `unsafeShiftR` (I# i#) = W64# (x# `uncheckedShiftRL#` i#)
        (W64# x#) `rotate` (I# i#)
            | isTrue# (i'# ==# 0#) = W64# x#
            | otherwise            = W64# ((x# `uncheckedShiftL#` i'#) `or#`
                                           (x# `uncheckedShiftRL#` (64# -# i'#)))
            where
            !i'# = word2Int# (int2Word# i# `and#` 63##)
        bitSizeMaybe i            = Just (finiteBitSize i)
        bitSize i                 = finiteBitSize i
        isSigned _                = False
        popCount (W64# x#)        = I# (word2Int# (popCnt64# x#))
        bit                       = bitDefault
        testBit                   = testBitDefault

    {-# RULES
    "fromIntegral/a->Word64" fromIntegral = \x -> case fromIntegral x of W# x# -> W64# x#
    "fromIntegral/Word64->a" fromIntegral = \(W64# x#) -> fromIntegral (W# x#)
      #-}

    uncheckedShiftL64# :: Word# -> Int# -> Word#
    uncheckedShiftL64#  = uncheckedShiftL#

    uncheckedShiftRL64# :: Word# -> Int# -> Word#
    uncheckedShiftRL64# = uncheckedShiftRL#

    #endif

    instance FiniteBits Word64 where
        finiteBitSize _ = 64
        countLeadingZeros  (W64# x#) = I# (word2Int# (clz64# x#))
        countTrailingZeros (W64# x#) = I# (word2Int# (ctz64# x#))

    instance Show Word64 where
        showsPrec p x = showsPrec p (toInteger x)

    instance Real Word64 where
        toRational x = toInteger x % 1

    instance Bounded Word64 where
        minBound = 0
        maxBound = 0xFFFFFFFFFFFFFFFF

    instance Ix Word64 where
        range (m,n)         = [m..n]
        unsafeIndex (m,_) i = fromIntegral (i - m)
        inRange (m,n) i     = m <= i && i <= n

    instance Read Word64 where
        readsPrec p s = [(fromInteger x, r) | (x, r) <- readsPrec p s]

    -- | Reverse order of bytes in 'Word64'.
    --
    -- @since 4.7.0.0
    #if WORD_SIZE_IN_BITS < 64
    byteSwap64 :: Word64 -> Word64
    byteSwap64 (W64# w#) = W64# (byteSwap64# w#)
    #else
    byteSwap64 :: Word64 -> Word64
    byteSwap64 (W64# w#) = W64# (byteSwap# w#)
    #endif