+% ------------------------------------------------------------------------------
+% $Id: PrelNum.lhs,v 1.46 2002/01/29 09:58:21 simonpj Exp $
%
-% (c) The AQUA Project, Glasgow University, 1994-1996
+% (c) The University of Glasgow, 1994-2000
%
\section[PrelNum]{Module @PrelNum@}
\begin{code}
-{-# OPTIONS -fcompiling-prelude -fno-implicit-prelude #-}
+{-# OPTIONS -fno-implicit-prelude #-}
+
+#include "MachDeps.h"
+#if SIZEOF_HSWORD == 4
+#define LEFTMOST_BIT 2147483648
+#elif SIZEOF_HSWORD == 8
+#define LEFTMOST_BIT 9223372036854775808
+#else
+#error Please define LEFTMOST_BIT to be 2^(SIZEOF_HSWORD*8-1)
+#endif
module PrelNum where
negate :: a -> a
abs, signum :: a -> a
fromInteger :: Integer -> a
- fromInt :: Int -> a -- partain: Glasgow extension
x - y = x + negate y
negate x = 0 - x
- fromInt (I# i#) = fromInteger (S# i#)
- -- Go via the standard class-op if the
- -- non-standard one ain't provided
-\end{code}
-
-A few small numeric functions
-\begin{code}
-subtract :: (Num a) => a -> a -> a
{-# INLINE subtract #-}
-subtract x y = y - x
-
-ord_0 :: Num a => a
-ord_0 = fromInt (ord '0')
+subtract :: (Num a) => a -> a -> a
+subtract x y = y - x
\end{code}
\begin{code}
instance Num Int where
- (+) x y = plusInt x y
- (-) x y = minusInt x y
- negate x = negateInt x
- (*) x y = timesInt x y
- abs n = if n `geInt` 0 then n else (negateInt n)
+ (+) = plusInt
+ (-) = minusInt
+ negate = negateInt
+ (*) = timesInt
+ abs n = if n `geInt` 0 then n else negateInt n
signum n | n `ltInt` 0 = negateInt 1
| n `eqInt` 0 = 0
| otherwise = 1
- fromInteger n = integer2Int n
- fromInt n = n
+ fromInteger = integer2Int
\end{code}
\begin{code}
data Integer
= S# Int# -- small integers
+#ifndef ILX
| J# Int# ByteArray# -- large integers
+#else
+ | J# Void BigInteger -- .NET big ints
+
+foreign type dotnet "BigInteger" BigInteger
+#endif
\end{code}
Convenient boxed Integer PrimOps.
integer2Int (S# i) = I# i
integer2Int (J# s d) = case (integer2Int# s d) of { n# -> I# n# }
-addr2Integer :: Addr# -> Integer
-{-# INLINE addr2Integer #-}
-addr2Integer x = case addr2Integer# x of (# s, d #) -> J# s d
-
toBig (S# i) = case int2Integer# i of { (# s, d #) -> J# s d }
toBig i@(J# _ _) = i
\end{code}
\begin{code}
quotRemInteger :: Integer -> Integer -> (Integer, Integer)
-quotRemInteger a@(S# (-2147483648#)) b = quotRemInteger (toBig a) b
+quotRemInteger a@(S# (-LEFTMOST_BIT#)) b = quotRemInteger (toBig a) b
quotRemInteger (S# i) (S# j)
= case quotRemInt (I# i) (I# j) of ( I# i, I# j ) -> ( S# i, S# j )
quotRemInteger i1@(J# _ _) i2@(S# _) = quotRemInteger i1 (toBig i2)
(# s3, d3, s4, d4 #)
-> (J# s3 d3, J# s4 d4)
-divModInteger a@(S# (-2147483648#)) b = divModInteger (toBig a) b
+divModInteger a@(S# (-LEFTMOST_BIT#)) b = divModInteger (toBig a) b
divModInteger (S# i) (S# j)
= case divModInt (I# i) (I# j) of ( I# i, I# j ) -> ( S# i, S# j)
divModInteger i1@(J# _ _) i2@(S# _) = divModInteger i1 (toBig i2)
remInteger :: Integer -> Integer -> Integer
remInteger ia 0
= error "Prelude.Integral.rem{Integer}: divide by 0"
-remInteger a@(S# (-2147483648#)) b = remInteger (toBig a) b
+remInteger a@(S# (-LEFTMOST_BIT#)) b = remInteger (toBig a) b
remInteger (S# a) (S# b) = S# (remInt# a b)
{- Special case doesn't work, because a 1-element J# has the range
-(2^32-1) -- 2^32-1, whereas S# has the range -2^31 -- (2^31-1)
remInteger (J# sa a) (S# b)
= case int2Integer# b of { (# sb, b #) ->
case remInteger# sa a sb b of { (# sr, r #) ->
- S# (sr *# (word2Int# (integer2Word# sr r))) }}
+ S# (integer2Int# sr r) }}
remInteger (J# sa a) (J# sb b)
= case remInteger# sa a sb b of (# sr, r #) -> J# sr r
quotInteger :: Integer -> Integer -> Integer
quotInteger ia 0
= error "Prelude.Integral.quot{Integer}: divide by 0"
-quotInteger a@(S# (-2147483648#)) b = quotInteger (toBig a) b
+quotInteger a@(S# (-LEFTMOST_BIT#)) b = quotInteger (toBig a) b
quotInteger (S# a) (S# b) = S# (quotInt# a b)
{- Special case disabled, see remInteger above
quotInteger (S# a) (J# sb b)
\begin{code}
gcdInteger :: Integer -> Integer -> Integer
-gcdInteger a@(S# (-2147483648#)) b = gcdInteger (toBig a) b
-gcdInteger a b@(S# (-2147483648#)) = gcdInteger a (toBig b)
-gcdInteger (S# a) (S# b) = S# (gcdInt# a b)
-gcdInteger ia@(S# a) ib@(J# sb b)
+-- SUP: Do we really need the first two cases?
+gcdInteger a@(S# (-LEFTMOST_BIT#)) b = gcdInteger (toBig a) b
+gcdInteger a b@(S# (-LEFTMOST_BIT#)) = gcdInteger a (toBig b)
+gcdInteger (S# a) (S# b) = case gcdInt (I# a) (I# b) of { I# c -> S# c }
+gcdInteger ia@(S# 0#) ib@(J# 0# _) = error "PrelNum.gcdInteger: gcd 0 0 is undefined"
+gcdInteger ia@(S# a) ib@(J# sb b)
| a ==# 0# = abs ib
| sb ==# 0# = abs ia
- | otherwise = S# (gcdIntegerInt# sb b a)
-gcdInteger ia@(J# sa a) ib@(S# b)
- | sa ==# 0# = abs ib
- | b ==# 0# = abs ia
- | otherwise = S# (gcdIntegerInt# sa a b)
+ | otherwise = S# (gcdIntegerInt# absSb b absA)
+ where absA = if a <# 0# then negateInt# a else a
+ absSb = if sb <# 0# then negateInt# sb else sb
+gcdInteger ia@(J# _ _) ib@(S# _) = gcdInteger ib ia
+gcdInteger (J# 0# _) (J# 0# _) = error "PrelNum.gcdInteger: gcd 0 0 is undefined"
gcdInteger (J# sa a) (J# sb b)
= case gcdInteger# sa a sb b of (# sg, g #) -> J# sg g
ab = abs b
divExact :: Integer -> Integer -> Integer
-divExact a@(S# (-2147483648#)) b = divExact (toBig a) b
+divExact a@(S# (-LEFTMOST_BIT#)) b = divExact (toBig a) b
divExact (S# a) (S# b) = S# (quotInt# a b)
divExact (S# a) (J# sb b)
- = S# (quotInt# a (sb *# (word2Int# (integer2Word# sb b))))
+ = S# (quotInt# a (integer2Int# sb b))
divExact (J# sa a) (S# b)
= case int2Integer# b of
(# sb, b #) -> case divExactInteger# sa a sb b of (# sd, d #) -> J# sd d
\begin{code}
instance Num Integer where
- (+) i1@(S# i) i2@(S# j)
- = case addIntC# i j of { (# r, c #) ->
- if c ==# 0# then S# r
- else toBig i1 + toBig i2 }
- (+) i1@(J# _ _) i2@(S# _) = i1 + toBig i2
- (+) i1@(S# _) i2@(J# _ _) = toBig i1 + i2
- (+) (J# s1 d1) (J# s2 d2)
- = case plusInteger# s1 d1 s2 d2 of (# s, d #) -> J# s d
-
- (-) i1@(S# i) i2@(S# j)
- = case subIntC# i j of { (# r, c #) ->
- if c ==# 0# then S# r
- else toBig i1 - toBig i2 }
- (-) i1@(J# _ _) i2@(S# _) = i1 - toBig i2
- (-) i1@(S# _) i2@(J# _ _) = toBig i1 - i2
- (-) (J# s1 d1) (J# s2 d2)
- = case minusInteger# s1 d1 s2 d2 of (# s, d #) -> J# s d
-
- (*) i1@(S# i) i2@(S# j)
- = case mulIntC# i j of { (# r, c #) ->
- if c ==# 0# then S# r
- else toBig i1 * toBig i2 }
- (*) i1@(J# _ _) i2@(S# _) = i1 * toBig i2
- (*) i1@(S# _) i2@(J# _ _) = toBig i1 * i2
- (*) (J# s1 d1) (J# s2 d2)
- = case timesInteger# s1 d1 s2 d2 of (# s, d #) -> J# s d
-
- negate (S# (-2147483648#)) = 2147483648
- negate (S# i) = S# (negateInt# i)
- negate (J# s d) = J# (negateInt# s) d
+ (+) = plusInteger
+ (-) = minusInteger
+ (*) = timesInteger
+ negate = negateInteger
+ fromInteger x = x
-- ORIG: abs n = if n >= 0 then n else -n
-
- abs (S# (-2147483648#)) = 2147483648
+ abs (S# (-LEFTMOST_BIT#)) = LEFTMOST_BIT
abs (S# i) = case abs (I# i) of I# j -> S# j
abs n@(J# s d) = if (s >=# 0#) then n else J# (negateInt# s) d
else if cmp ==# 0# then S# 0#
else S# (negateInt# 1#)
- fromInteger x = x
-
- fromInt (I# i) = S# i
+plusInteger i1@(S# i) i2@(S# j) = case addIntC# i j of { (# r, c #) ->
+ if c ==# 0# then S# r
+ else toBig i1 + toBig i2 }
+plusInteger i1@(J# _ _) i2@(S# _) = i1 + toBig i2
+plusInteger i1@(S# _) i2@(J# _ _) = toBig i1 + i2
+plusInteger (J# s1 d1) (J# s2 d2) = case plusInteger# s1 d1 s2 d2 of (# s, d #) -> J# s d
+
+minusInteger i1@(S# i) i2@(S# j) = case subIntC# i j of { (# r, c #) ->
+ if c ==# 0# then S# r
+ else toBig i1 - toBig i2 }
+minusInteger i1@(J# _ _) i2@(S# _) = i1 - toBig i2
+minusInteger i1@(S# _) i2@(J# _ _) = toBig i1 - i2
+minusInteger (J# s1 d1) (J# s2 d2) = case minusInteger# s1 d1 s2 d2 of (# s, d #) -> J# s d
+
+timesInteger i1@(S# i) i2@(S# j) = if mulIntMayOflo# i j ==# 0#
+ then S# (i *# j)
+ else toBig i1 * toBig i2
+timesInteger i1@(J# _ _) i2@(S# _) = i1 * toBig i2
+timesInteger i1@(S# _) i2@(J# _ _) = toBig i1 * i2
+timesInteger (J# s1 d1) (J# s2 d2) = case timesInteger# s1 d1 s2 d2 of (# s, d #) -> J# s d
+
+negateInteger (S# (-LEFTMOST_BIT#)) = LEFTMOST_BIT
+negateInteger (S# i) = S# (negateInt# i)
+negateInteger (J# s d) = J# (negateInt# s) d
\end{code}
{-# INLINE enumFromThen #-}
{-# INLINE enumFromTo #-}
{-# INLINE enumFromThenTo #-}
- enumFrom x = efdInteger x 1
- enumFromThen x y = efdInteger x (y-x)
- enumFromTo x lim = efdtInteger x 1 lim
- enumFromThenTo x y lim = efdtInteger x (y-x) lim
-
-
-efdInteger = enumDeltaIntegerList
-efdtInteger = enumDeltaToIntegerList
+ enumFrom x = enumDeltaInteger x 1
+ enumFromThen x y = enumDeltaInteger x (y-x)
+ enumFromTo x lim = enumDeltaToInteger x 1 lim
+ enumFromThenTo x y lim = enumDeltaToInteger x (y-x) lim
{-# RULES
-"efdInteger" forall x y. efdInteger x y = build (\c _ -> enumDeltaIntegerFB c x y)
-"efdtInteger" forall x y l.efdtInteger x y l = build (\c n -> enumDeltaToIntegerFB c n x y l)
-"enumDeltaInteger" enumDeltaIntegerFB (:) = enumDeltaIntegerList
-"enumDeltaToInteger" enumDeltaToIntegerFB (:) [] = enumDeltaToIntegerList
+"enumDeltaInteger" [~1] forall x y. enumDeltaInteger x y = build (\c _ -> enumDeltaIntegerFB c x y)
+"efdtInteger" [~1] forall x y l.enumDeltaToInteger x y l = build (\c n -> enumDeltaToIntegerFB c n x y l)
+"enumDeltaInteger" [1] enumDeltaIntegerFB (:) = enumDeltaInteger
+"enumDeltaToInteger" [1] enumDeltaToIntegerFB (:) [] = enumDeltaToInteger
#-}
enumDeltaIntegerFB :: (Integer -> b -> b) -> Integer -> Integer -> b
enumDeltaIntegerFB c x d = x `c` enumDeltaIntegerFB c (x+d) d
-enumDeltaIntegerList :: Integer -> Integer -> [Integer]
-enumDeltaIntegerList x d = x : enumDeltaIntegerList (x+d) d
+enumDeltaInteger :: Integer -> Integer -> [Integer]
+enumDeltaInteger x d = x : enumDeltaInteger (x+d) d
enumDeltaToIntegerFB c n x delta lim
| delta >= 0 = up_fb c n x delta lim
| otherwise = dn_fb c n x delta lim
-enumDeltaToIntegerList x delta lim
+enumDeltaToInteger x delta lim
| delta >= 0 = up_list x delta lim
| otherwise = dn_list x delta lim
%*********************************************************
\begin{code}
-instance Show Integer where
- showsPrec x = showSignedInteger x
- showList = showList__ (showsPrec 0)
-
-showSignedInteger :: Int -> Integer -> ShowS
-showSignedInteger p n r
- | n < 0 && p > 6 = '(':jtos n (')':r)
- | otherwise = jtos n r
+instance Show Integer where
+ showsPrec p n r
+ | p > 6 && n < 0 = '(' : jtos n (')' : r)
+ -- Minor point: testing p first gives better code
+ -- in the not-uncommon case where the p argument
+ -- is a constant
+ | otherwise = jtos n r
+ showList = showList__ (showsPrec 0)
jtos :: Integer -> String -> String
-jtos i rs
- | i < 0 = '-' : jtos' (-i) rs
- | otherwise = jtos' i rs
- where
- jtos' :: Integer -> String -> String
- jtos' n cs
- | n < 10 = chr (fromInteger n + (ord_0::Int)) : cs
- | otherwise = jtos' q (chr (integer2Int r + (ord_0::Int)) : cs)
+jtos n cs
+ | n < 0 = '-' : jtos' (-n) cs
+ | otherwise = jtos' n cs
where
- (q,r) = n `quotRemInteger` 10
+ jtos' :: Integer -> String -> String
+ jtos' n' cs'
+ | n' < 10 = case unsafeChr (ord '0' + fromInteger n') of
+ c@(C# _) -> c:cs'
+ | otherwise = case unsafeChr (ord '0' + fromInteger r) of
+ c@(C# _) -> jtos' q (c:cs')
+ where
+ (q,r) = n' `quotRemInteger` 10
\end{code}