X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Flib%2FglaExts%2FWord.lhs;fp=ghc%2Flib%2FglaExts%2FWord.lhs;h=9e4f7dd56451c5ba1bad05d3814e28bf334b3c52;hb=e84b92ee647e749ea48fecf3ad1f4f328f667a70;hp=f5cecf7320edc779626659238c25e8fe90fab8ec;hpb=c66ff15f613e4844f8a8f041eb3a0b2faf1da09b;p=ghc-hetmet.git

diff --git a/ghc/lib/glaExts/Word.lhs b/ghc/lib/glaExts/Word.lhs
index f5cecf7..9e4f7dd 100644
--- a/ghc/lib/glaExts/Word.lhs
+++ b/ghc/lib/glaExts/Word.lhs
@@ -1,19 +1,23 @@
 %
-% (c) The AQUA Project, Glasgow University, 1994-1996
+% (c) The AQUA Project, Glasgow University, 1997
 %
-
 \section[Word]{Module @Word@}
 
-This code is largely copied from the Hugs library of the same name.
+GHC implementation of the standard Hugs/GHC @Word@
+interface, types and operations over unsigned, sized
+quantities.
 
 \begin{code}
 {-# OPTIONS -fno-implicit-prelude #-}
-
 module Word
-	( Word8
-	, Word16
-	, Word32
-	, Word64
+	( Word8		 -- all abstract.
+	, Word16         -- instances: Eq, Ord
+	, Word32         --  Num, Bounded, Real,
+	, Word64         --  Integral, Ix, Enum,
+	                 --  Read, Show, Bits,
+			 --  CCallable, CReturnable
+			 --  (last two 
+
 	, word8ToWord32  -- :: Word8  -> Word32
 	, word32ToWord8  -- :: Word32 -> Word8
 	, word16ToWord32 -- :: Word16 -> Word32
@@ -30,9 +34,10 @@ import PrelBase
 import PrelNum
 import PrelRead
 import Ix
-import Error
+import GHCerr  ( error )
 import Bits
 import GHC
+import CCall
 
 -----------------------------------------------------------------------------
 -- The "official" coercion functions
@@ -55,56 +60,105 @@ intToWord16 = word32ToWord16 . intToWord32
 
 intToWord32 (I# x)   = W32# (int2Word# x)
 word32ToInt (W32# x) = I#   (word2Int# x)
+\end{code}
 
------------------------------------------------------------------------------
--- Word8
------------------------------------------------------------------------------
-
-newtype Word8  = W8 Word32
+\subsection[Word8]{The @Word8@ interface}
 
-word8ToWord32 (W8 x) = x .&. 0xff
-word32ToWord8 = W8
+The byte type @Word8@ is represented in the Haskell
+heap by boxing up a 32-bit quantity, @Word#@. An invariant
+for this representation is that the higher 24 bits are
+*always* zeroed out. A consequence of this is that
+operations that could possibly overflow have to mask
+out the top three bytes before building the resulting @Word8@.
 
-instance Eq  Word8     where (==)    = binop (==)
-instance Ord Word8     where compare = binop compare
+\begin{code}
+data Word8  = W8# Word#
+
+instance CCallable Word8
+instance CReturnable Word8
+
+word8ToWord32 (W8#  x) = W32# x
+word32ToWord8 (W32# x) = W8# (wordToWord8# x)
+
+-- mask out upper three bytes.
+intToWord8# :: Int# -> Word#
+intToWord8# i# = (int2Word# i#) `and#` (int2Word# 0xff#)
+
+wordToWord8# :: Word# -> Word#
+wordToWord8# w# = w# `and#` (int2Word# 0xff#)
+
+instance Eq  Word8     where 
+  (W8# x) == (W8# y) = x `eqWord#` y
+  (W8# x) /= (W8# y) = x `neWord#` y
+
+instance Ord Word8     where 
+  compare (W8# x#) (W8# y#) = compareWord# x# y#
+  (<)  (W8# x) (W8# y)      = x `ltWord#` y
+  (<=) (W8# x) (W8# y)      = x `leWord#` y
+  (>=) (W8# x) (W8# y)      = x `geWord#` y
+  (>)  (W8# x) (W8# y)      = x `gtWord#` y
+  max x@(W8# x#) y@(W8# y#) = 
+     case (compareWord# x# y#) of { LT -> y ; EQ -> x ; GT -> x }
+  min x@(W8# x#) y@(W8# y#) =
+     case (compareWord# x# y#) of { LT -> x ; EQ -> x ; GT -> y }
+
+-- Helper function, used by Ord Word* instances.
+compareWord# :: Word# -> Word# -> Ordering
+compareWord# x# y# 
+ | x# `ltWord#` y# = LT
+ | x# `eqWord#` y# = EQ
+ | otherwise       = GT
 
 instance Num Word8 where
-    x + y         = to (binop (+) x y)
-    x - y         = to (binop (-) x y)
-    negate        = to . negate . from
-    x * y         = to (binop (*) x y)
-    abs x         = x
-    signum        = signumReal
-    fromInteger   = to . integer2Word
-    fromInt       = intToWord8
+  (W8# x) + (W8# y) = 
+      W8# (intToWord8# (word2Int# x +# word2Int# y))
+  (W8# x) - (W8# y) = 
+      W8# (intToWord8# (word2Int# x -# word2Int# y))
+  (W8# x) * (W8# y) = 
+      W8# (intToWord8# (word2Int# x *# word2Int# y))
+  negate w@(W8# x)  = 
+     if x' ==# 0# 
+      then w
+      else W8# (int2Word# (0x100# -# x'))
+     where
+      x' = word2Int# x
+  abs x         = x
+  signum        = signumReal
+  fromInteger (J# a# s# d#) = W8# (intToWord8# (integer2Int# a# s# d#))
+  fromInt       = intToWord8
 
 instance Bounded Word8 where
-    minBound = 0
-    maxBound = 0xff
+  minBound = 0
+  maxBound = 0xff
 
 instance Real Word8 where
-    toRational x = toInteger x % 1
+  toRational x = toInteger x % 1
 
+-- Note: no need to mask results here 
+-- as they cannot overflow.
 instance Integral Word8 where
-    x `div` y     = to  (binop div x y)
-    x `quot` y    = to  (binop quot x y)
-    x `rem` y     = to  (binop rem x y)
-    x `mod` y     = to  (binop mod x y)
-    x `quotRem` y = to2 (binop quotRem x y)
-    divMod        = quotRem
-    toInteger     = toInteger . from
-    toInt         = word8ToInt
+  div  (W8# x)  (W8# y)   = W8# (x `quotWord#` y)
+  quot (W8# x)  (W8# y)   = W8# (x `quotWord#` y)
+  rem  (W8# x)  (W8# y)   = W8# (x `remWord#` y)
+  mod  (W8# x)  (W8# y)   = W8# (x `remWord#` y)
+  quotRem (W8# x) (W8# y) = (W8# (x `quotWord#` y), W8# (x `remWord#` y))
+  divMod  (W8# x) (W8# y) = (W8# (x `quotWord#` y), W8# (x `remWord#` y))
+  toInteger (W8# x)       = word2Integer# x
+  toInt x                 = word8ToInt x
 
 instance Ix Word8 where
     range (m,n)          = [m..n]
     index b@(m,n) i
-	   | inRange b i = word32ToInt (from (i - m))
-	   | otherwise   = error "index: Index out of range"
+	   | inRange b i = word8ToInt (i-m)
+	   | otherwise   = error (showString "Ix{Word8}.index: Index " .
+				  showParen True (showsPrec 0 i) .
+                                  showString " out of range " $
+				  showParen True (showsPrec 0 b) "")
     inRange (m,n) i      = m <= i && i <= n
 
 instance Enum Word8 where
-    toEnum         = to . intToWord32
-    fromEnum       = word32ToInt . from
+    toEnum    (I# i)  = W8# (intToWord8# i)
+    fromEnum  (W8# w) = I# (word2Int# w)
     enumFrom c       = map toEnum [fromEnum c .. fromEnum (maxBound::Word8)]
     enumFromThen c d = map toEnum [fromEnum c, fromEnum d .. fromEnum (last::Word8)]
 		       where last = if d < c then minBound else maxBound
@@ -115,70 +169,137 @@ instance Read Word8 where
 instance Show Word8 where
     showsPrec p = showInt
 
+--
+-- Word8s are represented by an (unboxed) 32-bit Word.
+-- The invariant is that the upper 24 bits are always zeroed out.
+--
 instance Bits Word8 where
-  x .&. y       = to (binop (.&.) x y)
-  x .|. y       = to (binop (.|.) x y)
-  x `xor` y     = to (binop xor x y)
-  complement    = to . complement . from
-  x `shift` i   = to (from x `shift` i)
---  rotate      
-  bit           = to . bit
-  setBit x i    = to (setBit (from x) i)
-  clearBit x i  = to (clearBit (from x) i)
-  complementBit x i = to (complementBit (from x) i)
-  testBit x i   = testBit (from x) i
+  (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#` int2Word# 0xff#)
+  shift (W8# x#) i@(I# i#)
+	| i > 0     = W8# (wordToWord8# (shiftL# x# i#))
+	| otherwise = W8# (wordToWord8# (shiftRL# x# (negateInt# i#)))
+  w@(W8# x)  `rotate` (I# i)
+        | i ==# 0#    = w
+	| i ># 0#     = W8# ((wordToWord8# (shiftL# x i')) `or#`
+	                     (shiftRL# (x `and#` 
+			                (int2Word# (0x100# -# pow2# i2)))
+			               i2))
+	| otherwise = rotate w (I# (8# +# i))
+          where
+           i' = word2Int# (int2Word# i `and#` int2Word# 7#)
+           i2 = 8# -# i'
+
+  bit (I# i#)
+	| i# >=# 0# && i# <=# 7# = W8# (wordToWord8# (shiftL# (int2Word# 1#) i#))
+	| otherwise = 0 -- We'll be overbearing, for now..
+
+  setBit x i    = x .|. bit i
+  clearBit x i  = x .&. complement (bit i)
+  complementBit x i = x `xor` bit i
+
+  testBit (W8# x#) (I# i#)
+    | i# <# 8# && i# >=# 0# = (word2Int# (x# `and#` (shiftL# (int2Word# 1#) i#))) /=# 0#
+    | otherwise             = False -- for now, this is really an error.
+
   bitSize  _    = 8
   isSigned _    = False
 
------------------------------------------------------------------------------
--- Word16
------------------------------------------------------------------------------
+pow2# :: Int# -> Int#
+pow2# x# = word2Int# (shiftL# (int2Word# 1#) x#)
 
-newtype Word16 = W16 Word32
+\end{code}
+
+\subsection[Word16]{The @Word16@ interface}
 
-word16ToWord32 (W16 x) = x .&. 0xffff
-word32ToWord16 = W16
+The double byte type @Word16@ is represented in the Haskell
+heap by boxing up a machine word, @Word#@. An invariant
+for this representation is that only the lower 16 bits are
+`active', any bits above are {\em always} zeroed out.
+A consequence of this is that operations that could possibly
+overflow have to mask out anything above the lower two bytes
+before putting together the resulting @Word16@.
 
-instance Eq  Word16     where (==)    = binop (==)
-instance Ord Word16     where compare = binop compare
+\begin{code}
+data Word16 = W16# Word#
+instance CCallable Word16
+instance CReturnable Word16
+
+word16ToWord32 (W16# x) = W32# x
+word32ToWord16 (W32# x) = W16# (wordToWord16# x)
+
+-- mask out upper 16 bits.
+intToWord16# :: Int# -> Word#
+intToWord16# i# = ((int2Word# i#) `and#` (int2Word# 0xffff#))
+
+wordToWord16# :: Word# -> Word#
+wordToWord16# w# = w# `and#` (int2Word# 0xffff#)
+
+instance Eq  Word16    where 
+  (W16# x) == (W16# y) = x `eqWord#` y
+  (W16# x) /= (W16# y) = x `neWord#` y
+
+instance Ord Word16     where
+  compare (W16# x#) (W16# y#) = compareWord# x# y#
+  (<)  (W16# x) (W16# y)      = x `ltWord#` y
+  (<=) (W16# x) (W16# y)      = x `leWord#` y
+  (>=) (W16# x) (W16# y)      = x `geWord#` y
+  (>)  (W16# x) (W16# y)      = x `gtWord#` y
+  max x@(W16# x#) y@(W16# y#) = 
+     case (compareWord# x# y#) of { LT -> y ; EQ -> x ; GT -> x }
+  min x@(W16# x#) y@(W16# y#) =
+     case (compareWord# x# y#) of { LT -> x ; EQ -> x ; GT -> y }
 
 instance Num Word16 where
-    x + y         = to (binop (+) x y)
-    x - y         = to (binop (-) x y)
-    negate        = to . negate . from
-    x * y         = to (binop (*) x y)
-    abs x         = x
-    signum        = signumReal
-    fromInteger   = to . integer2Word
-    fromInt       = intToWord16
+  (W16# x) + (W16# y) = 
+       W16# (intToWord16# (word2Int# x +# word2Int# y))
+  (W16# x) - (W16# y) = 
+       W16# (intToWord16# (word2Int# x -# word2Int# y))
+  (W16# x) * (W16# y) = 
+       W16# (intToWord16# (word2Int# x *# word2Int# y))
+  negate w@(W16# x)  = 
+       if x' ==# 0# 
+        then w
+        else W16# (int2Word# (0x10000# -# x'))
+       where
+        x' = word2Int# x
+  abs x         = x
+  signum        = signumReal
+  fromInteger (J# a# s# d#) = W16# (intToWord16# (integer2Int# a# s# d#))
+  fromInt       = intToWord16
 
 instance Bounded Word16 where
-    minBound = 0
-    maxBound = 0xffff
+  minBound = 0
+  maxBound = 0xffff
 
 instance Real Word16 where
   toRational x = toInteger x % 1
 
 instance Integral Word16 where
-  x `div` y     = to  (binop div x y)
-  x `quot` y    = to  (binop quot x y)
-  x `rem` y     = to  (binop rem x y)
-  x `mod` y     = to  (binop mod x y)
-  x `quotRem` y = to2 (binop quotRem x y)
-  divMod        = quotRem
-  toInteger     = toInteger . from
-  toInt         = word16ToInt
+  div  (W16# x)  (W16# y)   = W16# (x `quotWord#` y)
+  quot (W16# x)  (W16# y)   = W16# (x `quotWord#` y)
+  rem  (W16# x)  (W16# y)   = W16# (x `remWord#` y)
+  mod  (W16# x)  (W16# y)   = W16# (x `remWord#` y)
+  quotRem (W16# x) (W16# y) = (W16# (x `quotWord#` y), W16# (x `remWord#` y))
+  divMod  (W16# x) (W16# y) = (W16# (x `quotWord#` y), W16# (x `remWord#` y))
+  toInteger (W16# x)        = word2Integer# x
+  toInt x                   = word16ToInt x
 
 instance Ix Word16 where
   range (m,n)          = [m..n]
   index b@(m,n) i
-         | inRange b i = word32ToInt (from (i - m))
-         | otherwise   = error "index: Index out of range"
+         | inRange b i = word16ToInt (i - m)
+         | otherwise   = error (showString "Ix{Word16}.index: Index " .
+				showParen True (showsPrec 0 i) .
+                                showString " out of range " $
+				showParen True (showsPrec 0 b) "")
   inRange (m,n) i      = m <= i && i <= n
 
 instance Enum Word16 where
-  toEnum         = to . intToWord32
-  fromEnum       = word32ToInt . from
+  toEnum    (I# i)   = W16# (intToWord16# i)
+  fromEnum  (W16# w) = I# (word2Int# w)
   enumFrom c       = map toEnum [fromEnum c .. fromEnum (maxBound::Word16)]
   enumFromThen c d = map toEnum [fromEnum c, fromEnum d .. fromEnum (last::Word16)]
 		       where last = if d < c then minBound else maxBound
@@ -190,75 +311,137 @@ instance Show Word16 where
   showsPrec p = showInt
 
 instance Bits Word16 where
-  x .&. y       = to (binop (.&.) x y)
-  x .|. y       = to (binop (.|.) x y)
-  x `xor` y     = to (binop xor x y)
-  complement    = to . complement . from
-  x `shift` i   = to (from x `shift` i)
---  rotate      
-  bit           = to . bit
-  setBit x i    = to (setBit (from x) i)
-  clearBit x i  = to (clearBit (from x) i)
-  complementBit x i = to (complementBit (from x) i)
-  testBit x i   = testBit (from x) i
+  (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#` int2Word# 0xffff#)
+  shift (W16# x#) i@(I# i#)
+	| i > 0     = W16# (wordToWord16# (shiftL# x# i#))
+	| otherwise = W16# (shiftRL# x# (negateInt# i#))
+  w@(W16# x)  `rotate` (I# i)
+        | i ==# 0#    = w
+	| i ># 0#     = W16# ((wordToWord16# (shiftL# x i')) `or#`
+	                      (shiftRL# (x `and#` 
+			                 (int2Word# (0x10000# -# pow2# i2)))
+			                i2))
+	| otherwise = rotate w (I# (16# +# i'))
+          where
+           i' = word2Int# (int2Word# i `and#` int2Word# 15#)
+           i2 = 16# -# i'
+  bit (I# i#)
+	| i# >=# 0# && i# <=# 15# = W16# (shiftL# (int2Word# 1#) i#)
+	| otherwise = 0 -- We'll be overbearing, for now..
+
+  setBit x i    = x .|. bit i
+  clearBit x i  = x .&. complement (bit i)
+  complementBit x i = x `xor` bit i
+
+  testBit (W16# x#) (I# i#)
+    | i# <# 16# && i# >=# 0# = (word2Int# (x# `and#` (shiftL# (int2Word# 1#) i#))) /=# 0#
+    | otherwise             = False -- for now, this is really an error.
+
   bitSize  _    = 16
   isSigned _    = False
 
------------------------------------------------------------------------------
--- Word32
---
--- This code assumes that Word# is 32-bits - which is true on a 32-bit
--- architecture, but will need to be updated for 64-bit architectures.
------------------------------------------------------------------------------
+\end{code}
+
+\subsection[Word32]{The @Word32@ interface}
 
-data Word32 = W32# Word# deriving (Eq, Ord)
+The quad byte type @Word32@ is represented in the Haskell
+heap by boxing up a machine word, @Word#@. An invariant
+for this representation is that any bits above the lower
+32 are {\em always} zeroed out. A consequence of this is that
+operations that could possibly overflow have to mask
+the result before building the resulting @Word16@.
+
+\begin{code}
+data Word32 = W32# Word#
+instance CCallable Word32
+instance CReturnable Word32
+
+instance Eq  Word32    where 
+  (W32# x) == (W32# y) = x `eqWord#` y
+  (W32# x) /= (W32# y) = x `neWord#` y
+
+instance Ord Word32    where
+  compare (W32# x#) (W32# y#) = compareWord# x# y#
+  (<)  (W32# x) (W32# y)      = x `ltWord#` y
+  (<=) (W32# x) (W32# y)      = x `leWord#` y
+  (>=) (W32# x) (W32# y)      = x `geWord#` y
+  (>)  (W32# x) (W32# y)      = x `gtWord#` y
+  max x@(W32# x#) y@(W32# y#) = 
+     case (compareWord# x# y#) of { LT -> y ; EQ -> x ; GT -> x }
+  min x@(W32# x#) y@(W32# y#) =
+     case (compareWord# x# y#) of { LT -> x ; EQ -> x ; GT -> y }
 
 instance Num Word32 where
-    (+) = intop (+)
-    (-) = intop (-)
-    (*) = intop (*)
-    negate (W32# x) = W32# (int2Word# (negateInt# (word2Int# x)))
-    abs x           = x
-    signum          = signumReal
-    fromInteger     = integer2Word
-    fromInt (I# x)  = W32# (int2Word# x)
-
-{-# INLINE intop #-}
-intop op x y = intToWord32 (word32ToInt x `op` word32ToInt y)
+  (W32# x) + (W32# y) = 
+       W32# (intToWord32# (word2Int# x +# word2Int# y))
+  (W32# x) - (W32# y) =
+       W32# (intToWord32# (word2Int# x -# word2Int# y))
+  (W32# x) * (W32# y) = 
+       W32# (intToWord32# (word2Int# x *# word2Int# y))
+#if WORD_SIZE_IN_BYTES > 4
+  negate w@(W32# x)  = 
+      if x' ==# 0#
+       then w
+       else W32# (intToWord32# (0x100000000# -# x'))
+       where
+        x' = word2Int# x
+#else
+  negate (W32# x)  = W32# (intToWord32# (negateInt# (word2Int# x)))
+#endif
+  abs x           = x
+  signum          = signumReal
+  fromInteger (J# a# s# d#) = W32# (intToWord32# (integer2Int# a# s# d#))
+  fromInt (I# x)  = W32# (intToWord32# x)
+    -- ToDo: restrict fromInt{eger} range.
+
+intToWord32#  :: Int#  -> Word#
+wordToWord32# :: Word# -> Word#
+
+#if WORD_SIZE_IN_BYTES > 4
+intToWord32#  i# = (int2Word# i#) `and#` (int2Word# 0xffffffff)
+wordToWord32# w# = w# `and#` (int2Word# 0xffffffff)
+#else
+intToWord32#  i# = int2Word# i#
+wordToWord32# w# = w#
+#endif
 
 instance Bounded Word32 where
     minBound = 0
+#if WORD_SIZE_IN_BYTES > 4
+    maxBound = 0xffffffff
+#else
     maxBound = minBound - 1
+#endif
 
 instance Real Word32 where
     toRational x = toInteger x % 1
 
 instance Integral Word32 where
-    x `div` y   = if x > 0 && y < 0	then quotWord (x-y-1) y
-		  else if x < 0 && y > 0	then quotWord (x-y+1) y
-		  else quotWord x y
-    quot	=  quotWord
-    rem		=  remWord
-    x `mod` y = if x > 0 && y < 0 || x < 0 && y > 0 then
-		    if r/=0 then r+y else 0
-	    	else
-		    r
-	      where r = remWord x y
-    a `quotRem` b    = (a `quot` b, a `rem` b)
-    divMod x y       = (x `div` y,  x `mod` y)
-    toInteger (W32# x) = int2Integer# (word2Int# x)
+    div  x y           =  quotWord32 x y
+    quot x y           =  quotWord32 x y
+    rem	 x y           =  remWord32 x y
+    mod  x y           =  remWord32 x y
+    quotRem a b        = (a `quotWord32` b, a `remWord32` b)
+    divMod x y         = quotRem x y
+    toInteger (W32# x) = word2Integer# x
     toInt     (W32# x) = I# (word2Int# x)
 
-{-# INLINE quotWord #-}
-{-# INLINE remWord  #-}
-(W32# x) `quotWord` (W32# y) = W32# (x `quotWord#` y)
-(W32# x) `remWord`  (W32# y) = W32# (x `remWord#`  y)
+{-# INLINE quotWord32 #-}
+{-# INLINE remWord32  #-}
+(W32# x) `quotWord32` (W32# y) = W32# (x `quotWord#` y)
+(W32# x) `remWord32`  (W32# y) = W32# (x `remWord#`  y)
 
 instance Ix Word32 where
     range (m,n)          = [m..n]
     index b@(m,n) i
 	   | inRange b i = word32ToInt (i - m)
-	   | otherwise   = error "index: Index out of range"
+	   | otherwise   = error (showString "Ix{Word32}.index: Index " .
+				  showParen True (showsPrec 0 i) .
+                                  showString " out of range " $
+				  showParen True (showsPrec 0 b) "")
     inRange (m,n) i      = m <= i && i <= n
 
 instance Enum Word32 where
@@ -275,29 +458,44 @@ instance Show Word32 where
     showsPrec p = showInt
 
 instance Bits Word32 where
-  (.&.)         = wordop and#
-  (.|.)         = wordop or#
-  xor           = wordop xor#
-  complement x  = x `xor` maxBound
+  (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
   shift (W32# x) i@(I# i#)
-	| i > 0     = W32# (shiftL# x i#)
-	| otherwise = W32# (shiftRA# x (negateInt# i#))
-  --rotate
-  bit i             = 1 `shift` i
+	| i > 0     = W32# (wordToWord32# (shiftL# x i#))
+	| otherwise = W32# (shiftRL# x (negateInt# i#))
+  w@(W32# x)  `rotate` (I# i)
+        | i ==# 0#    = w
+	| i ># 0#     = W32# ((wordToWord32# (shiftL# x i')) `or#`
+	                      (shiftRL# (x `and#` 
+			                (int2Word# (word2Int# maxBound# -# pow2# i2 +# 1#)))
+			             i2))
+	| otherwise = rotate w (I# (32# +# i))
+          where
+           i' = word2Int# (int2Word# i `and#` int2Word# 31#)
+           i2 = 32# -# i'
+           (W32# maxBound#) = maxBound
+
+  bit (I# i#)
+	| i# >=# 0# && i# <=# 31# = W32# (shiftL# (int2Word# 1#) i#)
+	| otherwise = 0 -- We'll be overbearing, for now..
+
   setBit x i        = x .|. bit i
   clearBit x i      = x .&. complement (bit i)
   complementBit x i = x `xor` bit i
-  testBit x i       = (x .&. bit i) /= 0
+
+  testBit (W32# x#) (I# i#)
+    | i# <# 32# && i# >=# 0# = (word2Int# (x# `and#` (shiftL# (int2Word# 1#) i#))) /=# 0#
+    | otherwise             = False -- for now, this is really an error.
   bitSize  _        = 32
   isSigned _        = False
 
-{-# INLINE wordop #-}
-wordop op (W32# x) (W32# y) = W32# (x `op` y)
+\end{code}
 
------------------------------------------------------------------------------
--- Word64
------------------------------------------------------------------------------
+\subsection[Word64]{The @Word64@ interface}
 
+\begin{code}
 data Word64 = W64 {lo,hi::Word32} deriving (Eq, Ord, Bounded)
 
 w64ToInteger W64{lo,hi} = toInteger lo + 0x100000000 * toInteger hi 
@@ -318,30 +516,6 @@ instance Read Word64 where
 -----------------------------------------------------------------------------
 
 -----------------------------------------------------------------------------
--- Coercions - used to make the instance declarations more uniform
------------------------------------------------------------------------------
-
-class Coerce a where
-  to   :: Word32 -> a
-  from :: a -> Word32
-
-instance Coerce Word8 where
-  from = word8ToWord32
-  to   = word32ToWord8
-
-instance Coerce Word16 where
-  from = word16ToWord32
-  to   = word32ToWord16
-
-binop :: Coerce word => (Word32 -> Word32 -> a) -> (word -> word -> a)
-binop op x y = from x `op` from y
-
-to2 :: Coerce word => (Word32, Word32) -> (word, word)
-to2 (x,y) = (to x, to y)
-
-integer2Word (J# a# s# d#) = W32# (int2Word# (integer2Int# a# s# d#))
-
------------------------------------------------------------------------------
 -- Code copied from the Prelude
 -----------------------------------------------------------------------------