@@ -4,6 +4,7 @@
44-- |
55-- Module : Data.Binary.Bits.Get
66-- Copyright : (c) Lennart Kolmodin 2010-2011
7+-- (c) Sylvain Henry 2015
78-- License : BSD3-style (see LICENSE)
89--
910-- Maintainer : kolmodin@gmail.com
@@ -59,11 +60,19 @@ module Data.Binary.Bits.Get
5960
6061 -- ** Get bytes
6162 , getBool
63+ , getBool#
6264 , getWord8
65+ , getWord16
66+ , getWord32
67+ , getWord64
6368 , getWord16be
6469 , getWord32be
6570 , getWord64be
6671
72+ -- ** Skip bits
73+ , skipBits
74+ , alignByte
75+
6776 -- * Blocks
6877
6978 -- $blocks
@@ -73,32 +82,41 @@ module Data.Binary.Bits.Get
7382 -- ** Read in Blocks
7483 , bool
7584 , word8
85+ , word16
86+ , word32
87+ , word64
7688 , word16be
7789 , word32be
7890 , word64be
7991 , byteString
8092 , Data.Binary.Bits.Get.getByteString
93+ , Data.Binary.Bits.Get.getLazyByteString
94+ , Data.Binary.Bits.Get.isEmpty
8195
8296 ) where
8397
84−import Data.Binary.Get as B ( runGet, Get, getByteString )
98+import Data.Binary.Get as B ( Get, getLazyByteString, isEmpty )
8599import 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
86103
87104import Data.ByteString as B
105+import qualified Data.ByteString.Lazy as L
88106import Data.ByteString.Unsafe
107+import Foreign.Marshal.Alloc (mallocBytes)
108+import Foreign.Ptr
109+import Foreign.Storable (poke)
110+import System.IO.Unsafe (unsafePerformIO)
89111
90112import Data.Bits
91113import Data.Word
92−
93114import Control.Applicative
115+import Control.Monad (when,foldM_)
94116
95117import Prelude as P
96−
97−#if defined(__GLASGOW_HASKELL__) && !defined(__HADDOCK__)
98−import GHC.Base
99118import GHC.Word
100−#endif
101−
119+import GHC.Base (uncheckedShiftLWord8#, wordToWord8#, Int (..), andWord8#, Word8#, (-#), Int#, xorI#, eqWord8#, TYPE)
102120
103121-- $bitget
104122-- Parse bits using a monad.
@@ -147,188 +165,120 @@ import GHC.Word
147165-- @
148166
149167data S = S {-# UNPACK #-} !ByteString -- Input
150− {-# UNPACK #-} !Int -- Bit offset (0-7)
168+ {-# UNPACK #-} !Int -- Bit offset (0-7)
169+ !BitOrder -- Bit order
151170 deriving (Show)
152171
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−
172+-- | Increment the current bit offset
177173incS :: Int -> S -> S
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 => 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
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'
199179
180+-- | Read a single bit
200181readBool :: S -> Bool
201−readBool (S bs n) = testBit (unsafeHead bs) (7-n)
202−
203−readWord8 :: Int -> S -> Word8
204−readWord8 n (S bs o)
205− -- no bits at all, return 0
206− | n == 0 = 0
207−
208− -- all bits are in the same byte
209− -- we just need to shift and mask them right
210− | n <= 8 - o = let w = unsafeHead bs
211− m = make_mask n
212− w' = (w `shiftr_w8` (8 - o - n)) .&. m
213− in w'
214−
215− -- the bits are in two different bytes
216− -- make a word16 using both bytes, and then shift and mask
217− | n <= 8 = let w = (fromIntegral (unsafeHead bs) `shiftl_w16` 8) .|.
218− (fromIntegral (unsafeIndex bs 1))
219− m = make_mask n
220− w' = (w `shiftr_w16` (16 - o - n)) .&. m
221− in fromIntegral w'
222−
223−
224−readWord16be :: Int -> S -> Word16
225−readWord16be n s@(S bs o)
226−
227− -- 8 or fewer bits, use readWord8
228− | n <= 8 = fromIntegral (readWord8 n s)
229−
230− -- handle 9 or more bits, stored in two bytes
231−
232− -- no offset, plain and simple 16 bytes
233− | o == 0 && n == 16 = let msb = fromIntegral (unsafeHead bs)
234− lsb = fromIntegral (unsafeIndex bs 1)
235− w = (msb `shiftl_w16` 8) .|. lsb
236− in w
237−
238− -- no offset, but not full 16 bytes
239− | o == 0 = let msb = fromIntegral (unsafeHead bs)
240− lsb = fromIntegral (unsafeIndex bs 1)
241− w = (msb `shiftl_w16` (n-8)) .|. (lsb `shiftr_w16` (16-n))
242− in w
243−
244− -- with offset, and n=9-16
245− | n <= 16 = readWithOffset s shiftl_w16 shiftr_w16 n
246−
247− | otherwise = error "readWord16be: tried to read more than 16 bits"
248−
249−readWord32be :: Int -> S -> Word32
250−readWord32be n s@(S _ o)
251− -- 8 or fewer bits, use readWord8
252− | n <= 8 = fromIntegral (readWord8 n s)
253−
254− -- 16 or fewer bits, use readWord16be
255− | n <= 16 = fromIntegral (readWord16be n s)
256−
257− | o == 0 = readWithoutOffset s shiftl_w32 shiftr_w32 n
258−
259− | n <= 32 = readWithOffset s shiftl_w32 shiftr_w32 n
260−
261− | otherwise = error "readWord32be: tried to read more than 32 bits"
262−
263−
264−readWord64be :: Int -> S -> Word64
265−readWord64be n s@(S _ o)
266− -- 8 or fewer bits, use readWord8
267− | n <= 8 = fromIntegral (readWord8 n s)
268−
269− -- 16 or fewer bits, use readWord16be
270− | n <= 16 = fromIntegral (readWord16be n s)
271−
272− | o == 0 = readWithoutOffset s shiftl_w64 shiftr_w64 n
273−
274− | n <= 64 = readWithOffset s shiftl_w64 shiftr_w64 n
275−
276− | otherwise = error "readWord64be: tried to read more than 64 bits"
277−
278−
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
279255readByteString :: Int -> S -> ByteString
280−readByteString n s@(S bs o)
281− -- no offset, easy.
282− | o == 0 = unsafeTake n bs
283− -- offset. ugg. this is really naive and slow. but also pretty easy :)
284− | otherwise = B.pack (P.map (readWord8 8) (P.take n (iterate (incS 8) s)))
285−
286−readWithoutOffset :: (Bits a, Num a)
287− => S -> (a -> Int -> a) -> (a -> Int -> a) -> Int -> a
288−readWithoutOffset (S bs o) shifterL shifterR n
289− | o /= 0 = error "readWithoutOffset: there is an offset"
290−
291− | bit_offset n == 0 && byte_offset n <= 4 =
292− let segs = byte_offset n
293− bn 0 = fromIntegral (unsafeHead bs)
294− bn n = (bn (n-1) `shifterL` 8) .|. fromIntegral (unsafeIndex bs n)
295−
296− in bn (segs-1)
297−
298− | n <= 64 = let segs = byte_offset n
299− o' = bit_offset (n - 8 + o)
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)
300281
301− bn 0 = fromIntegral (unsafeHead bs)
302− bn n = (bn (n-1) `shifterL` 8) .|. fromIntegral (unsafeIndex bs n)
303−
304− msegs = bn (segs-1) `shifterL` o'
305−
306− last = (fromIntegral (unsafeIndex bs segs)) `shifterR` (8 - o')
307−
308− w = msegs .|. last
309− in w
310−
311−readWithOffset :: (Bits a, Num a)
312− => S -> (a -> Int -> a) -> (a -> Int -> a) -> Int -> a
313−readWithOffset (S bs o) shifterL shifterR n
314− | n <= 64 = let bits_in_msb = 8 - o
315− (n',top) = (n - bits_in_msb
316− , (fromIntegral (unsafeHead bs) .&. make_mask bits_in_msb) `shifterL` n')
317−
318− segs = byte_offset n'
319−
320− bn 0 = 0
321− bn n = (bn (n-1) `shifterL` 8) .|. fromIntegral (unsafeIndex bs n)
322−
323− o' = bit_offset n'
324−
325− mseg = bn segs `shifterL` o'
326−
327− last | o' > 0 = (fromIntegral (unsafeIndex bs (segs + 1))) `shifterR` (8 - o')
328− | otherwise = 0
329−
330− w = top .|. mseg .|. last
331− in w
332282
333283------------------------------------------------------------------------
334284-- | 'BitGet' is a monad, applicative and a functor. See 'runBitGet'
@@ -337,7 +287,6 @@ newtype BitGet a = B { runState :: S -> Get (S,a) }
337287
338288instance Monad BitGet where
339289 return x = B $ \s -> return (s,x)
340− fail str = B $ \(S inp n) -> putBackState inp n >> fail str
341290 (B f) >>= g = B $ \s -> do (s',a) <- f s
342291 runState (g a) s'
343292
@@ -348,25 +297,51 @@ instance Applicative BitGet where
348297 pure x = return x
349298 fm <*> m = fm >>= \f -> m >>= \v -> return (f v)
350299
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+
351323-- | Run a 'BitGet' within the Binary packages 'Get' monad. If a byte has
352324-- been partially consumed it will be discarded once 'runBitGet' is finished.
353325runBitGet :: BitGet a -> Get a
354326runBitGet bg = do
355327 s <- mkInitState
356− ((S str' n),a) <- runState bg s
357− putBackState str' n
328+ (s',a) <- runState bg s
329+ putBackState s'
358330 return a
359331
360332mkInitState :: Get S
361333mkInitState = do
362− str <- get
334+ bs <- get
363335 put B.empty
364− return (S str 0)
336+ return (S bs 0 BB)
365337
366−putBackState :: B.ByteString -> Int -> Get ()
367−putBackState bs n = do
338+putBackState :: S -> Get ()
339+putBackState (S bs o _) = do
368340 remaining <- get
369− put (B.drop (if n==0 then 0 else 1) bs `B.append` remaining)
341+ let bs' = case o of
342+ 0 -> bs
343+ _ -> unsafeDrop 1 bs
344+ put (bs' `B.append` remaining)
370345
371346getState :: BitGet S
372347getState = B $ \s -> return (s,s)
@@ -374,110 +349,148 @@ getState = B $ \s -> return (s,s)
374349putState :: S -> BitGet ()
375350putState s = B $ \_ -> return (s,())
376351
352+withState :: (S -> S) -> BitGet ()
353+withState f = do
354+ s <- getState
355+ putState $! f s
356+
377357-- | Make sure there are at least @n@ bits.
378358ensureBits :: Int -> BitGet ()
379359ensureBits n = do
380− (S bs o) <- getState
360+ (S bs o bo) <- getState
381361 if n <= (B.length bs * 8 - o)
382362 then return ()
383363 else do let currentBits = B.length bs * 8 - o
384− let byteCount = (n - currentBits + 7) `div` 8
364+ let byteCount = byte_offset (n - currentBits + 7)
385365 B $ \_ -> do B.ensureN byteCount
386366 bs' <- B.get
387367 put B.empty
388− return (S (bs`append`bs') o, ())
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)
389376
390377-- | Get 1 bit as a 'Bool'.
391378getBool :: BitGet Bool
392379getBool = block bool
393380
381+-- | Get 1 bit as a 'Bool'.
382+getBool# :: BitGet Int
383+getBool# = block bool#
384+
394385-- | Get @n@ bits as a 'Word8'. @n@ must be within @[0..8]@.
395386getWord8 :: Int -> BitGet Word8
396387getWord8 n = block (word8 n)
397388
398389-- | Get @n@ bits as a 'Word16'. @n@ must be within @[0..16]@.
390+getWord16 :: Int -> BitGet Word16
391+getWord16 n = block (word16 n)
392+
399393getWord16be :: Int -> BitGet Word16
400−getWord16be n = block (word16be n)
394+getWord16be = getWord16
395+{-# DEPRECATED getWord16be "Use 'getWord16' instead" #-}
401396
402397-- | Get @n@ bits as a 'Word32'. @n@ must be within @[0..32]@.
398+getWord32 :: Int -> BitGet Word32
399+getWord32 n = block (word32 n)
400+
403401getWord32be :: Int -> BitGet Word32
404−getWord32be n = block (word32be n)
402+getWord32be = getWord32
403+{-# DEPRECATED getWord32be "Use 'getWord32' instead" #-}
405404
406405-- | Get @n@ bits as a 'Word64'. @n@ must be within @[0..64]@.
406+getWord64 :: Int -> BitGet Word64
407+getWord64 n = block (word64 n)
408+
407409getWord64be :: Int -> BitGet Word64
408−getWord64be n = block (word64be n)
410+getWord64be = getWord64
411+{-# DEPRECATED getWord64be "Use 'getWord64' instead" #-}
409412
410413-- | Get @n@ bytes as a 'ByteString'.
411414getByteString :: Int -> BitGet ByteString
412415getByteString n = block (byteString n)
413416
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+
414456-- | Read a 1 bit 'Bool'.
415457bool :: Block Bool
416458bool = Block 1 readBool
417459
460+-- | Read a 1 bit 'Bool'.
461+bool# :: Block Int
462+bool# = Block 1 readBool#
463+
418464-- | Read @n@ bits as a 'Word8'. @n@ must be within @[0..8]@.
419465word8 :: Int -> Block Word8
420−word8 n = Block n (readWord8 n)
466+word8 n = Block n (readWordChecked 8 n)
421467
422468-- | 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+
423472word16be :: Int -> Block Word16
424−word16be n = Block n (readWord16be n)
473+word16be = word16
474+{-# DEPRECATED word16be "Use 'word16' instead" #-}
425475
426476-- | 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+
427480word32be :: Int -> Block Word32
428−word32be n = Block n (readWord32be n)
481+word32be = word32
482+{-# DEPRECATED word32be "Use 'word32' instead" #-}
429483
430484-- | 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+
431488word64be :: Int -> Block Word64
432−word64be n = Block n (readWord64be n)
489+word64be = word64
490+{-# DEPRECATED word64be "Use 'word64' instead" #-}
433491
434492-- | Read @n@ bytes as a 'ByteString'.
435493byteString :: Int -> Block ByteString
436494byteString n | n > 0 = Block (n*8) (readByteString n)
437495 | otherwise = Block 0 (\_ -> B.empty)
438496
439−------------------------------------------------------------------------
440−-- Unchecked shifts, from the package binary
441−
442−shiftl_w16 :: Word16 -> Int -> Word16
443−shiftl_w32 :: Word32 -> Int -> Word32
444−shiftl_w64 :: Word64 -> Int -> Word64
445−
446−#if defined(__GLASGOW_HASKELL__) && !defined(__HADDOCK__)
447−shiftl_w8 (W8# w) (I# i) = W8# (w `uncheckedShiftL#` i)
448−shiftl_w16 (W16# w) (I# i) = W16# (w `uncheckedShiftL#` i)
449−shiftl_w32 (W32# w) (I# i) = W32# (w `uncheckedShiftL#` i)
450−
451−shiftr_w8 (W8# w) (I# i) = W8# (w `uncheckedShiftRL#` i)
452−shiftr_w16 (W16# w) (I# i) = W16# (w `uncheckedShiftRL#` i)
453−shiftr_w32 (W32# w) (I# i) = W32# (w `uncheckedShiftRL#` i)
454−
455−
456−#if WORD_SIZE_IN_BITS < 64
457−shiftl_w64 (W64# w) (I# i) = W64# (w `uncheckedShiftL64#` i)
458−shiftr_w64 (W64# w) (I# i) = W64# (w `uncheckedShiftRL64#` i)
459−
460−#if __GLASGOW_HASKELL__ <= 606
461−-- Exported by GHC.Word in GHC 6.8 and higher
462−foreign import ccall unsafe "stg_uncheckedShiftL64"
463− uncheckedShiftL64# :: Word64# -> Int# -> Word64#
464−foreign import ccall unsafe "stg_uncheckedShiftRL64"
465− uncheckedShiftRL64# :: Word64# -> Int# -> Word64#
466−#endif
467−
468−#else
469−shiftl_w64 (W64# w) (I# i) = W64# (w `uncheckedShiftL#` i)
470−shiftr_w64 (W64# w) (I# i) = W64# (w `uncheckedShiftRL#` i)
471−#endif
472−
473−#else
474−shiftl_w8 = shiftL
475−shiftl_w16 = shiftL
476−shiftl_w32 = shiftL
477−shiftl_w64 = shiftL
478−
479−shiftr_w8 = shiftR
480−shiftr_w16 = shiftR
481−shiftr_w32 = shiftR
482−shiftr_w64 = shiftR
483−#endif