@@ -4,7 +4,6 @@
44-- |
55-- Module : Data.Binary.Bits.Get
66-- Copyright : (c) Lennart Kolmodin 2010-2011
7−-- (c) Sylvain Henry 2015
87-- License : BSD3-style (see LICENSE)
98--
109-- Maintainer : kolmodin@gmail.com
@@ -60,19 +59,11 @@ module Data.Binary.Bits.Get
6059
6160 -- ** Get bytes
6261 , getBool
63− , getBool#
6462 , getWord8
65− , getWord16
66− , getWord32
67− , getWord64
6863 , getWord16be
6964 , getWord32be
7065 , getWord64be
7166
72− -- ** Skip bits
73− , skipBits
74− , alignByte
75−
7667 -- * Blocks
7768
7869 -- $blocks
@@ -82,41 +73,32 @@ module Data.Binary.Bits.Get
8273 -- ** Read in Blocks
8374 , bool
8475 , word8
85− , word16
86− , word32
87− , word64
8876 , word16be
8977 , word32be
9078 , word64be
9179 , byteString
9280 , Data.Binary.Bits.Get.getByteString
93− , Data.Binary.Bits.Get.getLazyByteString
94− , Data.Binary.Bits.Get.isEmpty
9581
9682 ) where
9783
98−import Data.Binary.Get as B ( Get, getLazyByteString, isEmpty )
84+import Data.Binary.Get as B ( runGet, Get, getByteString )
9985import Data.Binary.Get.Internal as B ( get, put, ensureN )
100−import Data.Binary.Bits.BitOrder
101−import Data.Binary.Bits.Internal
102−import Data.Binary.Bits.Alignment
10386
10487import Data.ByteString as B
105−import qualified Data.ByteString.Lazy as L
10688import Data.ByteString.Unsafe
107−import Foreign.Marshal.Alloc (mallocBytes)
108−import Foreign.Ptr
109−import Foreign.Storable (poke)
110−import System.IO.Unsafe (unsafePerformIO)
11189
11290import Data.Bits
11391import Data.Word
92+
11493import Control.Applicative
115−import Control.Monad (when,foldM_)
11694
11795import Prelude as P
96+
97+#if defined(__GLASGOW_HASKELL__) && !defined(__HADDOCK__)
98+import GHC.Base
11899import GHC.Word
119−import GHC.Base (uncheckedShiftLWord8#, wordToWord8#, Int (..), andWord8#, Word8#, (-#), Int#, xorI#, eqWord8#, TYPE)
100+#endif
101+
120102
121103-- $bitget
122104-- Parse bits using a monad.
@@ -165,120 +147,191 @@ import GHC.Base (uncheckedShiftLWord8#, wordToWord8#, Int (..), andWord8#, Word8
165147-- @
166148
167149data S = S {-# UNPACK #-} !ByteString -- Input
168− {-# UNPACK #-} !Int -- Bit offset (0-7)
169− !BitOrder -- Bit order
150+ {-# UNPACK #-} !Int -- Bit offset (0-7)
170151 deriving (Show)
171152
172−-- | Increment the current bit offset
153+-- | A block that will be read with only one boundry check. Needs to know the
154+-- number of bits in advance.
155+data Block a = Block Int (S -> a)
156+
157+instance Functor Block where
158+ fmap f (Block i p) = Block i (\s -> f (p s))
159+
160+instance Applicative Block where
161+ pure a = Block 0 (\_ -> a)
162+ (Block i p) <*> (Block j q) = Block (i+j) (\s -> p s $ q (incS i s))
163+ (Block i _) *> (Block j q) = Block (i+j) (q . incS i)
164+ (Block i p) <* (Block j _) = Block (i+j) p
165+
166+-- | Get a block. Will be read with one single boundry check, and
167+-- therefore requires a statically known number of bits.
168+-- Build blocks using 'bool', 'word8', 'word16be', 'word32be', 'word64be',
169+-- 'byteString' and 'Applicative'.
170+block :: Block a -> BitGet a
171+block (Block i p) = do
172+ ensureBits i
173+ s <- getState
174+ putState $! (incS i s)
175+ return $! p s
176+
173177incS :: Int -> S -> S
174−incS o (S bs n bo) = S (unsafeDrop d bs) n' bo
175− where
176− !o' = (n+o)
177− !d = byte_offset o'
178− !n' = bit_offset o'
178+incS o (S bs n) =
179+ let !o' = (n+o)
180+ !d = o' `shiftR` 3
181+ !n' = o' .&. make_mask 3
182+ in S (unsafeDrop d bs) n'
183+
184+-- | make_mask 3 = 00000111
185+make_mask :: (Bits a, Num a) => Int -> a
186+make_mask n = (1 `shiftL` fromIntegral n) - 1
187+{-# SPECIALIZE make_mask :: Int -> Int #-}
188+{-# SPECIALIZE make_mask :: Int -> Word #-}
189+{-# SPECIALIZE make_mask :: Int -> Word8 #-}
190+{-# SPECIALIZE make_mask :: Int -> Word16 #-}
191+{-# SPECIALIZE make_mask :: Int -> Word32 #-}
192+{-# SPECIALIZE make_mask :: Int -> Word64 #-}
193+
194+bit_offset :: Int -> Int
195+bit_offset n = make_mask 3 .&. n
196+
197+byte_offset :: Int -> Int
198+byte_offset n = n `shiftR` 3
179199
180−-- | Read a single bit
181200readBool :: S -> Bool
182−readBool (S bs o bo) = case bo of
183− BB -> testBit (unsafeHead bs) (7-o)
184− BL -> testBit (unsafeHead bs) (7-o)
185− LL -> testBit (unsafeHead bs) o
186− LB -> testBit (unsafeHead bs) o
187−
188−-- | Read a single bit
189−readBool# :: S -> Int
190−readBool# (S bs (I# o) bo) = case bo of
191− BB -> testBit# (7# -# o)
192− BL -> testBit# (7# -# o)
193− LL -> testBit# o
194− LB -> testBit# o
195− where
196− !(W8# w) = unsafeHead bs
197− testBit# n = I# (((w `andWord8#` (wordToWord8# 1## `uncheckedShiftLWord8#` n)) `eqWord8#` wordToWord8# 0##) `xorI#` 1#)
198−
199−
200−-- | Extract a range of bits from (ws :: ByteString)
201−--
202−-- Constraint: 8 * (length ws -1 ) < o+n <= 8 * length ws
203−extract :: (Num a, FastBits a) => BitOrder -> ByteString -> Int -> Int -> a
204−extract bo bs o n
205− | n == 0 = 0
206− | B.length bs == 0 = error "Empty ByteString"
207− | otherwise = rev . mask n . foldlWithIndex' f 0 $ bs
208− where
209− -- B.foldl' with index
210− foldlWithIndex' op b = fst . B.foldl' g (b,0)
211− where g (b',i) w = (op b' w i, (i+1))
212−
213− -- 'or' correctly shifted words
214− f b w i = b .|. (fromIntegral w `fastShift` off i)
215−
216− -- co-offset
217− r = B.length bs * 8 - (o + n)
218−
219− -- shift offset depending on the byte position (0..B.length-1)
220− off i = case bo of
221− LL -> 8*i - o
222− LB -> 8*i - o
223− BB -> (B.length bs -1 - i) * 8 - r
224− BL -> (B.length bs -1 - i) * 8 - r
225−
226− -- reverse bits if necessary
227− rev = case bo of
228− LB -> reverseBits n
229− BL -> reverseBits n
230− BB -> id
231− LL -> id
232−
233−
234−-- | Generic readWord
235−readWord :: (Num a, FastBits a) => Int -> S -> a
236−readWord n (S bs o bo)
237− | n == 0 = 0
238− | otherwise = extract bo (unsafeTake nbytes bs) o n
239− where nbytes = byte_offset (o+n+7)
240−
241−-- | Check that the number of bits to read is not greater than the first parameter
242−{-# INLINE readWordChecked #-}
243−readWordChecked :: (Num a, FastBits a) => Int -> Int -> S -> a
244−readWordChecked m n s
245− | n > m = error $ "Tried to read more than " ++ show m ++ " bits (" ++ show n ++")"
246− | otherwise = readWord n s
247−
248−-- | Read the given number of bytes and return them in Big-Endian order
249−--
250−-- Examples:
251−-- BB: xxxABCDE FGHIJKLM NOPxxxxx -> ABCDEFGH IJKLMNOP
252−-- LL: LMNOPxxx DEFGHIJK xxxxxABC -> ABCDEFGH IJKLMNOP
253−-- BL: xxxPONML KJIHGFED CBAxxxxx -> ABCDEFGH IJKLMNOP
254−-- LB: EDCBAxxx MLKJIHGF xxxxxPON -> ABCDEFGH IJKLMNOP
201+readBool (S bs n) = testBit (unsafeHead bs) (7-n)
202+
203+{-# INLINE readWord8 #-}
204+readWord8 :: Int -> S -> Word8
205+readWord8 n (S bs o)
206+ -- no bits at all, return 0
207+ | n == 0 = 0
208+
209+ -- all bits are in the same byte
210+ -- we just need to shift and mask them right
211+ | n <= 8 - o = let w = unsafeHead bs
212+ m = make_mask n
213+ w' = (w `shiftr_w8` (8 - o - n)) .&. m
214+ in w'
215+
216+ -- the bits are in two different bytes
217+ -- make a word16 using both bytes, and then shift and mask
218+ | n <= 8 = let w = (fromIntegral (unsafeHead bs) `shiftl_w16` 8) .|.
219+ (fromIntegral (unsafeIndex bs 1))
220+ m = make_mask n
221+ w' = (w `shiftr_w16` (16 - o - n)) .&. m
222+ in fromIntegral w'
223+
224+{-# INLINE readWord16be #-}
225+readWord16be :: Int -> S -> Word16
226+readWord16be n s@(S bs o)
227+
228+ -- 8 or fewer bits, use readWord8
229+ | n <= 8 = fromIntegral (readWord8 n s)
230+
231+ -- handle 9 or more bits, stored in two bytes
232+
233+ -- no offset, plain and simple 16 bytes
234+ | o == 0 && n == 16 = let msb = fromIntegral (unsafeHead bs)
235+ lsb = fromIntegral (unsafeIndex bs 1)
236+ w = (msb `shiftl_w16` 8) .|. lsb
237+ in w
238+
239+ -- no offset, but not full 16 bytes
240+ | o == 0 = let msb = fromIntegral (unsafeHead bs)
241+ lsb = fromIntegral (unsafeIndex bs 1)
242+ w = (msb `shiftl_w16` (n-8)) .|. (lsb `shiftr_w16` (16-n))
243+ in w
244+
245+ -- with offset, and n=9-16
246+ | n <= 16 = readWithOffset s shiftl_w16 shiftr_w16 n
247+
248+ | otherwise = error "readWord16be: tried to read more than 16 bits"
249+
250+{-# INLINE readWord32be #-}
251+readWord32be :: Int -> S -> Word32
252+readWord32be n s@(S _ o)
253+ -- 8 or fewer bits, use readWord8
254+ | n <= 8 = fromIntegral (readWord8 n s)
255+
256+ -- 16 or fewer bits, use readWord16be
257+ | n <= 16 = fromIntegral (readWord16be n s)
258+
259+ | o == 0 = readWithoutOffset s shiftl_w32 shiftr_w32 n
260+
261+ | n <= 32 = readWithOffset s shiftl_w32 shiftr_w32 n
262+
263+ | otherwise = error "readWord32be: tried to read more than 32 bits"
264+
265+
266+{-# INLINE readWord64be #-}
267+readWord64be :: Int -> S -> Word64
268+readWord64be n s@(S _ o)
269+ -- 8 or fewer bits, use readWord8
270+ | n <= 8 = fromIntegral (readWord8 n s)
271+
272+ -- 16 or fewer bits, use readWord16be
273+ | n <= 16 = fromIntegral (readWord16be n s)
274+
275+ | o == 0 = readWithoutOffset s shiftl_w64 shiftr_w64 n
276+
277+ | n <= 64 = readWithOffset s shiftl_w64 shiftr_w64 n
278+
279+ | otherwise = error "readWord64be: tried to read more than 64 bits"
280+
281+
255282readByteString :: Int -> S -> ByteString
256−readByteString n (S bs o bo) =
257− let
258− bs' = unsafeTake (n+1) bs
259− bs'' = unsafeTake n bs
260− rev = B.map (reverseBits 8)
261− in case (o,bo) of
262− (0,BB) -> bs''
263− (0,LL) -> B.reverse bs''
264− (0,LB) -> rev bs''
265− (0,BL) -> rev . B.reverse $ bs''
266− (_,LL) -> readByteString n (S (B.reverse bs') (8-o) BB)
267− (_,BL) -> rev . B.reverse $ readByteString n (S bs' o BB)
268− (_,LB) -> rev . B.reverse $ readByteString n (S bs' o LL)
269− (_,BB) -> unsafePerformIO $ do
270− let len = n+1
271− ptr <- mallocBytes len
272− let f r i = do
273− let
274− w = unsafeIndex bs (len-i)
275− w' = (w `fastShiftL` o) .|. r
276− r' = w `fastShiftR` (8-o)
277− poke (ptr `plusPtr` (len-i)) w'
278− return r'
279− foldM_ f 0 [1..len]
280− unsafeInit <$> unsafePackMallocCStringLen (ptr,len)
283+readByteString n s@(S bs o)
284+ -- no offset, easy.
285+ | o == 0 = unsafeTake n bs
286+ -- offset. ugg. this is really naive and slow. but also pretty easy :)
287+ | otherwise = B.pack (P.map (readWord8 8) (P.take n (iterate (incS 8) s)))
288+
289+readWithoutOffset :: (Bits a, Num a)
290+ => S -> (a -> Int -> a) -> (a -> Int -> a) -> Int -> a
291+readWithoutOffset (S bs o) shifterL shifterR n
292+ | o /= 0 = error "readWithoutOffset: there is an offset"
293+
294+ | bit_offset n == 0 && byte_offset n <= 4 =
295+ let segs = byte_offset n
296+ bn 0 = fromIntegral (unsafeHead bs)
297+ bn n = (bn (n-1) `shifterL` 8) .|. fromIntegral (unsafeIndex bs n)
298+
299+ in bn (segs-1)
300+
301+ | n <= 64 = let segs = byte_offset n
302+ o' = bit_offset (n - 8 + o)
281303
304+ bn 0 = fromIntegral (unsafeHead bs)
305+ bn n = (bn (n-1) `shifterL` 8) .|. fromIntegral (unsafeIndex bs n)
306+
307+ msegs = bn (segs-1) `shifterL` o'
308+
309+ last = (fromIntegral (unsafeIndex bs segs)) `shifterR` (8 - o')
310+
311+ w = msegs .|. last
312+ in w
313+
314+readWithOffset :: (Bits a, Num a)
315+ => S -> (a -> Int -> a) -> (a -> Int -> a) -> Int -> a
316+readWithOffset (S bs o) shifterL shifterR n
317+ | n <= 64 = let bits_in_msb = 8 - o
318+ (n',top) = (n - bits_in_msb
319+ , (fromIntegral (unsafeHead bs) .&. make_mask bits_in_msb) `shifterL` n')
320+
321+ segs = byte_offset n'
322+
323+ bn 0 = 0
324+ bn n = (bn (n-1) `shifterL` 8) .|. fromIntegral (unsafeIndex bs n)
325+
326+ o' = bit_offset n'
327+
328+ mseg = bn segs `shifterL` o'
329+
330+ last | o' > 0 = (fromIntegral (unsafeIndex bs (segs + 1))) `shifterR` (8 - o')
331+ | otherwise = 0
332+
333+ w = top .|. mseg .|. last
334+ in w
282335
283336------------------------------------------------------------------------
284337-- | 'BitGet' is a monad, applicative and a functor. See 'runBitGet'
@@ -287,6 +340,7 @@ newtype BitGet a = B { runState :: S -> Get (S,a) }
287340
288341instance Monad BitGet where
289342 return x = B $ \s -> return (s,x)
343+ fail str = B $ \(S inp n) -> putBackState inp n >> fail str
290344 (B f) >>= g = B $ \s -> do (s',a) <- f s
291345 runState (g a) s'
292346
@@ -297,51 +351,25 @@ instance Applicative BitGet where
297351 pure x = return x
298352 fm <*> m = fm >>= \f -> m >>= \v -> return (f v)
299353
300−instance BitOrderable BitGet where
301− setBitOrder bo = do
302− (S bs o _) <- getState
303− putState (S bs o bo)
304−
305− getBitOrder = do
306− (S _ _ bo) <- getState
307− return bo
308−
309−instance Alignable BitGet where
310− -- | Skip the given number of bits
311− skipBits n = do
312− ensureBits n
313− withState (incS n)
314−
315− -- | Skip bits if necessary to align to the next byte
316− alignByte = do
317− (S _ o _) <- getState
318− when (o /= 0) $
319− skipBits (8-o)
320−
321−
322−
323354-- | Run a 'BitGet' within the Binary packages 'Get' monad. If a byte has
324355-- been partially consumed it will be discarded once 'runBitGet' is finished.
325356runBitGet :: BitGet a -> Get a
326357runBitGet bg = do
327358 s <- mkInitState
328− (s',a) <- runState bg s
329− putBackState s'
359+ ((S str' n),a) <- runState bg s
360+ putBackState str' n
330361 return a
331362
332363mkInitState :: Get S
333364mkInitState = do
334− bs <- get
365+ str <- get
335366 put B.empty
336− return (S bs 0 BB)
367+ return (S str 0)
337368
338−putBackState :: S -> Get ()
339−putBackState (S bs o _) = do
369+putBackState :: B.ByteString -> Int -> Get ()
370+putBackState bs n = do
340371 remaining <- get
341− let bs' = case o of
342− 0 -> bs
343− _ -> unsafeDrop 1 bs
344− put (bs' `B.append` remaining)
372+ put (B.drop (if n==0 then 0 else 1) bs `B.append` remaining)
345373
346374getState :: BitGet S
347375getState = B $ \s -> return (s,s)
@@ -349,148 +377,110 @@ getState = B $ \s -> return (s,s)
349377putState :: S -> BitGet ()
350378putState s = B $ \_ -> return (s,())
351379
352−withState :: (S -> S) -> BitGet ()
353−withState f = do
354− s <- getState
355− putState $! f s
356−
357380-- | Make sure there are at least @n@ bits.
358381ensureBits :: Int -> BitGet ()
359382ensureBits n = do
360− (S bs o bo) <- getState
383+ (S bs o) <- getState
361384 if n <= (B.length bs * 8 - o)
362385 then return ()
363386 else do let currentBits = B.length bs * 8 - o
364− let byteCount = byte_offset (n - currentBits + 7)
387+ let byteCount = (n - currentBits + 7) `div` 8
365388 B $ \_ -> do B.ensureN byteCount
366389 bs' <- B.get
367390 put B.empty
368− return (S (bs`append`bs') o bo, ())
369−
370−-- | Test whether all input has been consumed, i.e. there are no remaining
371−-- undecoded bytes.
372−isEmpty :: BitGet Bool
373−isEmpty = B $ \ (S bs o bo) -> if B.null bs
374− then B.isEmpty >>= \e -> return (S bs o bo, e)
375− else return (S bs o bo, False)
391+ return (S (bs`append`bs') o, ())
376392
377393-- | Get 1 bit as a 'Bool'.
378394getBool :: BitGet Bool
379395getBool = block bool
380396
381−-- | Get 1 bit as a 'Bool'.
382−getBool# :: BitGet Int
383−getBool# = block bool#
384−
385397-- | Get @n@ bits as a 'Word8'. @n@ must be within @[0..8]@.
386398getWord8 :: Int -> BitGet Word8
387399getWord8 n = block (word8 n)
388400
389401-- | Get @n@ bits as a 'Word16'. @n@ must be within @[0..16]@.
390−getWord16 :: Int -> BitGet Word16
391−getWord16 n = block (word16 n)
392−
393402getWord16be :: Int -> BitGet Word16
394−getWord16be = getWord16
395−{-# DEPRECATED getWord16be "Use 'getWord16' instead" #-}
403+getWord16be n = block (word16be n)
396404
397405-- | Get @n@ bits as a 'Word32'. @n@ must be within @[0..32]@.
398−getWord32 :: Int -> BitGet Word32
399−getWord32 n = block (word32 n)
400−
401406getWord32be :: Int -> BitGet Word32
402−getWord32be = getWord32
403−{-# DEPRECATED getWord32be "Use 'getWord32' instead" #-}
407+getWord32be n = block (word32be n)
404408
405409-- | Get @n@ bits as a 'Word64'. @n@ must be within @[0..64]@.
406−getWord64 :: Int -> BitGet Word64
407−getWord64 n = block (word64 n)
408−
409410getWord64be :: Int -> BitGet Word64
410−getWord64be = getWord64
411−{-# DEPRECATED getWord64be "Use 'getWord64' instead" #-}
411+getWord64be n = block (word64be n)
412412
413413-- | Get @n@ bytes as a 'ByteString'.
414414getByteString :: Int -> BitGet ByteString
415415getByteString n = block (byteString n)
416416
417−-- | Get @n@ bytes as a lazy ByteString.
418−getLazyByteString :: Int -> BitGet L.ByteString
419−getLazyByteString n = do
420− (S _ o bo) <- getState
421− case o of
422− 0 -> B $ \s -> do
423− putBackState s
424− lbs <- B.getLazyByteString (fromIntegral n)
425− return (S B.empty 0 bo, lbs)
426− _ -> L.fromChunks . (:[]) <$> Data.Binary.Bits.Get.getByteString n
427−
428−
429−
430−
431−
432−-- | A block that will be read with only one boundary check. Needs to know the
433−-- number of bits in advance.
434−data Block a = Block Int (S -> a)
435−
436−instance Functor Block where
437− fmap f (Block i p) = Block i (\s -> f (p s))
438−
439−instance Applicative Block where
440− pure a = Block 0 (\_ -> a)
441− (Block i p) <*> (Block j q) = Block (i+j) (\s -> p s $ q (incS i s))
442− (Block i _) *> (Block j q) = Block (i+j) (q . incS i)
443− (Block i p) <* (Block j _) = Block (i+j) p
444−
445−-- | Get a block. Will be read with one single boundry check, and
446−-- therefore requires a statically known number of bits.
447−-- Build blocks using 'bool', 'word8', 'word16be', 'word32be', 'word64be',
448−-- 'byteString' and 'Applicative'.
449−block :: Block a -> BitGet a
450−block (Block i p) = do
451− ensureBits i
452− s <- getState
453− putState $! (incS i s)
454− return $! p s
455−
456417-- | Read a 1 bit 'Bool'.
457418bool :: Block Bool
458419bool = Block 1 readBool
459420
460−-- | Read a 1 bit 'Bool'.
461−bool# :: Block Int
462−bool# = Block 1 readBool#
463−
464421-- | Read @n@ bits as a 'Word8'. @n@ must be within @[0..8]@.
465422word8 :: Int -> Block Word8
466−word8 n = Block n (readWordChecked 8 n)
423+word8 n = Block n (readWord8 n)
467424
468425-- | Read @n@ bits as a 'Word16'. @n@ must be within @[0..16]@.
469−word16 :: Int -> Block Word16
470−word16 n = Block n (readWordChecked 16 n)
471−
472426word16be :: Int -> Block Word16
473−word16be = word16
474−{-# DEPRECATED word16be "Use 'word16' instead" #-}
427+word16be n = Block n (readWord16be n)
475428
476429-- | Read @n@ bits as a 'Word32'. @n@ must be within @[0..32]@.
477−word32 :: Int -> Block Word32
478−word32 n = Block n (readWordChecked 32 n)
479−
480430word32be :: Int -> Block Word32
481−word32be = word32
482−{-# DEPRECATED word32be "Use 'word32' instead" #-}
431+word32be n = Block n (readWord32be n)
483432
484433-- | Read @n@ bits as a 'Word64'. @n@ must be within @[0..64]@.
485−word64 :: Int -> Block Word64
486−word64 n = Block n (readWordChecked 64 n)
487−
488434word64be :: Int -> Block Word64
489−word64be = word64
490−{-# DEPRECATED word64be "Use 'word64' instead" #-}
435+word64be n = Block n (readWord64be n)
491436
492437-- | Read @n@ bytes as a 'ByteString'.
493438byteString :: Int -> Block ByteString
494439byteString n | n > 0 = Block (n*8) (readByteString n)
495440 | otherwise = Block 0 (\_ -> B.empty)
496441
442+------------------------------------------------------------------------
443+-- Unchecked shifts, from the package binary
444+
445+shiftl_w16 :: Word16 -> Int -> Word16
446+shiftl_w32 :: Word32 -> Int -> Word32
447+shiftl_w64 :: Word64 -> Int -> Word64
448+
449+#if defined(__GLASGOW_HASKELL__) && !defined(__HADDOCK__)
450+shiftl_w8 (W8# w) (I# i) = W8# (w `uncheckedShiftL#` i)
451+shiftl_w16 (W16# w) (I# i) = W16# (w `uncheckedShiftL#` i)
452+shiftl_w32 (W32# w) (I# i) = W32# (w `uncheckedShiftL#` i)
453+
454+shiftr_w8 (W8# w) (I# i) = W8# (w `uncheckedShiftRL#` i)
455+shiftr_w16 (W16# w) (I# i) = W16# (w `uncheckedShiftRL#` i)
456+shiftr_w32 (W32# w) (I# i) = W32# (w `uncheckedShiftRL#` i)
457+
458+
459+#if WORD_SIZE_IN_BITS < 64
460+shiftl_w64 (W64# w) (I# i) = W64# (w `uncheckedShiftL64#` i)
461+shiftr_w64 (W64# w) (I# i) = W64# (w `uncheckedShiftRL64#` i)
462+
463+#if __GLASGOW_HASKELL__ <= 606
464+-- Exported by GHC.Word in GHC 6.8 and higher
465+foreign import ccall unsafe "stg_uncheckedShiftL64"
466+ uncheckedShiftL64# :: Word64# -> Int# -> Word64#
467+foreign import ccall unsafe "stg_uncheckedShiftRL64"
468+ uncheckedShiftRL64# :: Word64# -> Int# -> Word64#
469+#endif
470+
471+#else
472+shiftl_w64 (W64# w) (I# i) = W64# (w `uncheckedShiftL#` i)
473+shiftr_w64 (W64# w) (I# i) = W64# (w `uncheckedShiftRL#` i)
474+#endif
475+
476+#else
477+shiftl_w8 = shiftL
478+shiftl_w16 = shiftL
479+shiftl_w32 = shiftL
480+shiftl_w64 = shiftL
481+
482+shiftr_w8 = shiftR
483+shiftr_w16 = shiftR
484+shiftr_w32 = shiftR
485+shiftr_w64 = shiftR
486+#endif