[project @ 2001-05-04 09:37:13 by qrczak]

Since overlapping rules (when one is more specific than the other)
seem to be handled well, add remaining fromIntegral rules to have
optimal conversions in all cases (given available primops).

diff --git a/ghc/lib/std/PrelInt.lhs b/ghc/lib/std/PrelInt.lhs
index c7ecd75..a413e05 100644 (file)
--- a/ghc/lib/std/PrelInt.lhs
+++ b/ghc/lib/std/PrelInt.lhs
@@ -120,9 +120,10 @@ instance Bits Int8 where
     isSigned _                = True
 
 {-# RULES
-"fromIntegral/a->Int8" fromIntegral = \x -> case fromIntegral x of I# x# -> I8# (intToInt8# x#)
-"fromIntegral/Int8->a" fromIntegral = \(I8# x#) -> fromIntegral (I# x#)
-    #-}
+"fromIntegral/Int8->Int8" fromIntegral = id :: Int8 -> Int8
+"fromIntegral/a->Int8"    fromIntegral = \x -> case fromIntegral x of I# x# -> I8# (intToInt8# x#)
+"fromIntegral/Int8->a"    fromIntegral = \(I8# x#) -> fromIntegral (I# x#)
+  #-}
 
 ------------------------------------------------------------------------
 -- type Int16
@@ -225,9 +226,12 @@ instance Bits Int16 where
     isSigned _                 = True
 
 {-# RULES
-"fromIntegral/a->Int16" fromIntegral = \x -> case fromIntegral x of I# x# -> I16# (intToInt16# x#)
-"fromIntegral/Int16->a" fromIntegral = \(I16# x#) -> fromIntegral (I# x#)
-    #-}
+"fromIntegral/Word8->Int16"  fromIntegral = \(W8# x#) -> I16# (word2Int# x#)
+"fromIntegral/Int8->Int16"   fromIntegral = \(I8# x#) -> I16# x#
+"fromIntegral/Int16->Int16"  fromIntegral = id :: Int16 -> Int16
+"fromIntegral/a->Int16"      fromIntegral = \x -> case fromIntegral x of I# x# -> I16# (intToInt16# x#)
+"fromIntegral/Int16->a"      fromIntegral = \(I16# x#) -> fromIntegral (I# x#)
+  #-}
 
 ------------------------------------------------------------------------
 -- type Int32
@@ -337,9 +341,14 @@ instance Bits Int32 where
     isSigned _                 = True
 
 {-# RULES
-"fromIntegral/a->Int32" fromIntegral = \x -> case fromIntegral x of I# x# -> I32# (intToInt32# x#)
-"fromIntegral/Int32->a" fromIntegral = \(I32# x#) -> fromIntegral (I# x#)
-    #-}
+"fromIntegral/Word8->Int32"  fromIntegral = \(W8# x#) -> I32# (word2Int# x#)
+"fromIntegral/Word16->Int32" fromIntegral = \(W16# x#) -> I32# (word2Int# x#)
+"fromIntegral/Int8->Int32"   fromIntegral = \(I8# x#) -> I32# x#
+"fromIntegral/Int16->Int32"  fromIntegral = \(I16# x#) -> I32# x#
+"fromIntegral/Int32->Int32"  fromIntegral = id :: Int32 -> Int32
+"fromIntegral/a->Int32"      fromIntegral = \x -> case fromIntegral x of I# x# -> I32# (intToInt32# x#)
+"fromIntegral/Int32->a"      fromIntegral = \(I32# x#) -> fromIntegral (I# x#)
+  #-}
 
 ------------------------------------------------------------------------
 -- type Int64
@@ -485,7 +494,7 @@ foreign import "stg_shiftRL64"     unsafe shiftRL64#     :: Word64# -> Int# -> W
 "fromIntegral/Int64->Word"   fromIntegral = \(I64# x#) -> W#   (int2Word# (int64ToInt# x#))
 "fromIntegral/Int64->Word64" fromIntegral = \(I64# x#) -> W64# (int64ToWord64# x#)
 "fromIntegral/Int64->Int64"  fromIntegral = id :: Int64 -> Int64
-    #-}
+  #-}
 
 #else
 
@@ -563,7 +572,7 @@ instance Bits Int64 where
 {-# RULES
 "fromIntegral/a->Int64" fromIntegral = \x -> case fromIntegral x of I# x# -> I64# (intToInt64# x#)
 "fromIntegral/Int64->a" fromIntegral = \(I64# x#) -> fromIntegral (I# x#)
-    #-}
+  #-}
 
 #endif
 

diff --git a/ghc/lib/std/PrelWord.lhs b/ghc/lib/std/PrelWord.lhs
index 63d8cc8..7848de2 100644 (file)
--- a/ghc/lib/std/PrelWord.lhs
+++ b/ghc/lib/std/PrelWord.lhs
@@ -168,7 +168,7 @@ instance Bits Word where
 "fromIntegral/Int->Word"  fromIntegral = \(I# x#) -> W# (int2Word# x#)
 "fromIntegral/Word->Int"  fromIntegral = \(W# x#) -> I# (word2Int# x#)
 "fromIntegral/Word->Word" fromIntegral = id :: Word -> Word
-    #-}
+  #-}
 
 ------------------------------------------------------------------------
 -- type Word8
@@ -265,9 +265,11 @@ instance Bits Word8 where
     isSigned _                = False
 
 {-# RULES
-"fromIntegral/a->Word8" fromIntegral = \x -> case fromIntegral x of W# x# -> W8# (wordToWord8# x#)
-"fromIntegral/Word8->a" fromIntegral = \(W8# x#) -> fromIntegral (W# x#)
-    #-}
+"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# (wordToWord8# x#)
+"fromIntegral/Word8->a"       fromIntegral = \(W8# x#) -> fromIntegral (W# x#)
+  #-}
 
 ------------------------------------------------------------------------
 -- type Word16
@@ -364,9 +366,12 @@ instance Bits Word16 where
     isSigned _                = False
 
 {-# RULES
-"fromIntegral/a->Word16" fromIntegral = \x -> case fromIntegral x of W# x# -> W16# (wordToWord16# x#)
-"fromIntegral/Word16->a" fromIntegral = \(W16# x#) -> fromIntegral (W# x#)
-    #-}
+"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# (wordToWord16# x#)
+"fromIntegral/Word16->a"       fromIntegral = \(W16# x#) -> fromIntegral (W# x#)
+  #-}
 
 ------------------------------------------------------------------------
 -- type Word32
@@ -496,9 +501,13 @@ instance Bits Word32 where
     isSigned _                = False
 
 {-# RULES
-"fromIntegral/a->Word32" fromIntegral = \x -> case fromIntegral x of W# x# -> W32# (wordToWord32# x#)
-"fromIntegral/Word32->a" fromIntegral = \(W32# x#) -> fromIntegral (W# x#)
-    #-}
+"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# (wordToWord32# x#)
+"fromIntegral/Word32->a"       fromIntegral = \(W32# x#) -> fromIntegral (W# x#)
+  #-}
 
 ------------------------------------------------------------------------
 -- type Word64
@@ -616,7 +625,7 @@ foreign import "stg_shiftRL64"     unsafe shiftRL64#     :: Word64# -> Int# -> W
 "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
 
@@ -695,7 +704,7 @@ instance Bits Word64 where
 {-# RULES
 "fromIntegral/a->Word64" fromIntegral = \x -> case fromIntegral x of W# x# -> W64# x#
 "fromIntegral/Word64->a" fromIntegral = \(W64# x#) -> fromIntegral (W# x#)
-    #-}
+  #-}
 
 #endif