Use unchecked shifts to implement Data.Bits.rotate

This should get rid of those cases, maybe lower the size enough that the inliner will like it?

diff --git a/Data/Bits.hs b/Data/Bits.hs
index eb8ace1..4564bce 100644 (file)
--- a/Data/Bits.hs
+++ b/Data/Bits.hs
@@ -203,8 +203,8 @@ instance Bits Int where
         | i# >=# 0#        = I# (x# `iShiftL#` i#)
         | otherwise        = I# (x# `iShiftRA#` negateInt# i#)
     (I# x#) `rotate` (I# i#) =
-        I# (word2Int# ((x'# `shiftL#` i'#) `or#`
-                       (x'# `shiftRL#` (wsib -# i'#))))
+        I# (word2Int# ((x'# `uncheckedShiftL#` i'#) `or#`
+                       (x'# `uncheckedShiftRL#` (wsib -# i'#))))
         where
         x'# = int2Word# x#
         i'# = word2Int# (int2Word# i# `and#` int2Word# (wsib -# 1#))

diff --git a/GHC/Int.hs b/GHC/Int.hs
index 3fff7dd..7ee7b1b 100644 (file)
--- a/GHC/Int.hs
+++ b/GHC/Int.hs
@@ -125,8 +125,8 @@ instance Bits Int8 where
         | i'# ==# 0# 
         = I8# x#
         | otherwise
-        = I8# (narrow8Int# (word2Int# ((x'# `shiftL#` i'#) `or#`
-                                       (x'# `shiftRL#` (8# -# i'#)))))
+        = I8# (narrow8Int# (word2Int# ((x'# `uncheckedShiftL#` i'#) `or#`
+                                       (x'# `uncheckedShiftRL#` (8# -# i'#)))))
         where
         x'# = narrow8Word# (int2Word# x#)
         i'# = word2Int# (int2Word# i# `and#` int2Word# 7#)
@@ -232,8 +232,8 @@ instance Bits Int16 where
         | i'# ==# 0# 
         = I16# x#
         | otherwise
-        = I16# (narrow16Int# (word2Int# ((x'# `shiftL#` i'#) `or#`
-                                         (x'# `shiftRL#` (16# -# i'#)))))
+        = I16# (narrow16Int# (word2Int# ((x'# `uncheckedShiftL#` i'#) `or#`
+                                         (x'# `uncheckedShiftRL#` (16# -# i'#)))))
         where
         x'# = narrow16Word# (int2Word# x#)
         i'# = word2Int# (int2Word# i# `and#` int2Word# 15#)
@@ -486,8 +486,8 @@ instance Bits Int32 where
         | i'# ==# 0# 
         = I32# x#
         | otherwise
-        = I32# (narrow32Int# (word2Int# ((x'# `shiftL#` i'#) `or#`
-                                        (x'# `shiftRL#` (32# -# i'#)))))
+        = I32# (narrow32Int# (word2Int# ((x'# `uncheckedShiftL#` i'#) `or#`
+                                         (x'# `uncheckedShiftRL#` (32# -# i'#)))))
         where
         x'# = narrow32Word# (int2Word# x#)
         i'# = word2Int# (int2Word# i# `and#` int2Word# 31#)
@@ -765,8 +765,8 @@ instance Bits Int64 where
         | i'# ==# 0# 
         = I64# x#
         | otherwise
-        = I64# (word2Int# ((x'# `shiftL#` i'#) `or#`
-                           (x'# `shiftRL#` (64# -# i'#))))
+        = I64# (word2Int# ((x'# `uncheckedShiftL#` i'#) `or#`
+                           (x'# `uncheckedShiftRL#` (64# -# i'#))))
         where
         x'# = int2Word# x#
         i'# = word2Int# (int2Word# i# `and#` int2Word# 63#)

diff --git a/GHC/Word.hs b/GHC/Word.hs
index 87b6e63..694a9df 100644 (file)
--- a/GHC/Word.hs
+++ b/GHC/Word.hs
@@ -164,7 +164,7 @@ instance Bits Word where
         | otherwise          = W# (x# `shiftRL#` negateInt# i#)
     (W# x#) `rotate` (I# i#)
         | i'# ==# 0# = W# x#
-        | otherwise  = W# ((x# `shiftL#` i'#) `or#` (x# `shiftRL#` (wsib -# i'#)))
+        | otherwise  = W# ((x# `uncheckedShiftL#` i'#) `or#` (x# `uncheckedShiftRL#` (wsib -# i'#)))
         where
         i'# = word2Int# (int2Word# i# `and#` int2Word# (wsib -# 1#))
        wsib = WORD_SIZE_IN_BITS#  {- work around preprocessor problem (??) -}
@@ -264,8 +264,8 @@ instance Bits Word8 where
         | otherwise           = W8# (x# `shiftRL#` negateInt# i#)
     (W8# x#) `rotate` (I# i#)
         | i'# ==# 0# = W8# x#
-        | otherwise  = W8# (narrow8Word# ((x# `shiftL#` i'#) `or#`
-                                          (x# `shiftRL#` (8# -# i'#))))
+        | otherwise  = W8# (narrow8Word# ((x# `uncheckedShiftL#` i'#) `or#`
+                                          (x# `uncheckedShiftRL#` (8# -# i'#))))
         where
         i'# = word2Int# (int2Word# i# `and#` int2Word# 7#)
     bitSize  _                = 8
@@ -365,8 +365,8 @@ instance Bits Word16 where
         | otherwise            = W16# (x# `shiftRL#` negateInt# i#)
     (W16# x#) `rotate` (I# i#)
         | i'# ==# 0# = W16# x#
-        | otherwise  = W16# (narrow16Word# ((x# `shiftL#` i'#) `or#`
-                                            (x# `shiftRL#` (16# -# i'#))))
+        | otherwise  = W16# (narrow16Word# ((x# `uncheckedShiftL#` i'#) `or#`
+                                            (x# `uncheckedShiftRL#` (16# -# i'#))))
         where
         i'# = word2Int# (int2Word# i# `and#` int2Word# 15#)
     bitSize  _                = 16
@@ -595,8 +595,8 @@ instance Bits Word32 where
         | otherwise            = W32# (x# `shiftRL#` negateInt# i#)
     (W32# x#) `rotate` (I# i#)
         | i'# ==# 0# = W32# x#
-        | otherwise  = W32# (narrow32Word# ((x# `shiftL#` i'#) `or#`
-                                            (x# `shiftRL#` (32# -# i'#))))
+        | otherwise  = W32# (narrow32Word# ((x# `uncheckedShiftL#` i'#) `or#`
+                                            (x# `uncheckedShiftRL#` (32# -# i'#))))
         where
         i'# = word2Int# (int2Word# i# `and#` int2Word# 31#)
     bitSize  _                = 32
@@ -856,8 +856,8 @@ instance Bits Word64 where
         | otherwise            = W64# (x# `shiftRL#` negateInt# i#)
     (W64# x#) `rotate` (I# i#)
         | i'# ==# 0# = W64# x#
-        | otherwise  = W64# ((x# `shiftL#` i'#) `or#`
-                             (x# `shiftRL#` (64# -# i'#)))
+        | otherwise  = W64# ((x# `uncheckedShiftL#` i'#) `or#`
+                             (x# `uncheckedShiftRL#` (64# -# i'#)))
         where
         i'# = word2Int# (int2Word# i# `and#` int2Word# 63#)
     bitSize  _                = 64