1 % ------------------------------------------------------------------------------
2 % $Id: Float.lhs,v 1.1 2001/06/28 14:15:03 simonmar Exp $
4 % (c) The University of Glasgow, 1994-2000
7 \section[GHC.Num]{Module @GHC.Num@}
20 {-# OPTIONS -fno-implicit-prelude #-}
22 #include "ieee-flpt.h"
24 module GHC.Float( module GHC.Float, Float#, Double# ) where
38 %*********************************************************
40 \subsection{Standard numeric classes}
42 %*********************************************************
45 class (Fractional a) => Floating a where
47 exp, log, sqrt :: a -> a
48 (**), logBase :: a -> a -> a
49 sin, cos, tan :: a -> a
50 asin, acos, atan :: a -> a
51 sinh, cosh, tanh :: a -> a
52 asinh, acosh, atanh :: a -> a
54 x ** y = exp (log x * y)
55 logBase x y = log y / log x
58 tanh x = sinh x / cosh x
60 class (RealFrac a, Floating a) => RealFloat a where
61 floatRadix :: a -> Integer
62 floatDigits :: a -> Int
63 floatRange :: a -> (Int,Int)
64 decodeFloat :: a -> (Integer,Int)
65 encodeFloat :: Integer -> Int -> a
68 scaleFloat :: Int -> a -> a
69 isNaN, isInfinite, isDenormalized, isNegativeZero, isIEEE
74 exponent x = if m == 0 then 0 else n + floatDigits x
75 where (m,n) = decodeFloat x
77 significand x = encodeFloat m (negate (floatDigits x))
78 where (m,_) = decodeFloat x
80 scaleFloat k x = encodeFloat m (n+k)
81 where (m,n) = decodeFloat x
85 | x == 0 && y > 0 = pi/2
86 | x < 0 && y > 0 = pi + atan (y/x)
88 (x < 0 && isNegativeZero y) ||
89 (isNegativeZero x && isNegativeZero y)
91 | y == 0 && (x < 0 || isNegativeZero x)
92 = pi -- must be after the previous test on zero y
93 | x==0 && y==0 = y -- must be after the other double zero tests
94 | otherwise = x + y -- x or y is a NaN, return a NaN (via +)
98 %*********************************************************
100 \subsection{Type @Integer@, @Float@, @Double@}
102 %*********************************************************
105 data Float = F# Float#
106 data Double = D# Double#
108 instance CCallable Float
109 instance CReturnable Float
111 instance CCallable Double
112 instance CReturnable Double
116 %*********************************************************
118 \subsection{Type @Float@}
120 %*********************************************************
123 instance Eq Float where
124 (F# x) == (F# y) = x `eqFloat#` y
126 instance Ord Float where
127 (F# x) `compare` (F# y) | x `ltFloat#` y = LT
128 | x `eqFloat#` y = EQ
131 (F# x) < (F# y) = x `ltFloat#` y
132 (F# x) <= (F# y) = x `leFloat#` y
133 (F# x) >= (F# y) = x `geFloat#` y
134 (F# x) > (F# y) = x `gtFloat#` y
136 instance Num Float where
137 (+) x y = plusFloat x y
138 (-) x y = minusFloat x y
139 negate x = negateFloat x
140 (*) x y = timesFloat x y
142 | otherwise = negateFloat x
143 signum x | x == 0.0 = 0
145 | otherwise = negate 1
147 {-# INLINE fromInteger #-}
148 fromInteger n = encodeFloat n 0
149 -- It's important that encodeFloat inlines here, and that
150 -- fromInteger in turn inlines,
151 -- so that if fromInteger is applied to an (S# i) the right thing happens
153 instance Real Float where
154 toRational x = (m%1)*(b%1)^^n
155 where (m,n) = decodeFloat x
158 instance Fractional Float where
159 (/) x y = divideFloat x y
160 fromRational x = fromRat x
163 {-# RULES "truncate/Float->Int" truncate = float2Int #-}
164 instance RealFrac Float where
166 {-# SPECIALIZE properFraction :: Float -> (Int, Float) #-}
167 {-# SPECIALIZE round :: Float -> Int #-}
168 {-# SPECIALIZE ceiling :: Float -> Int #-}
169 {-# SPECIALIZE floor :: Float -> Int #-}
171 {-# SPECIALIZE properFraction :: Float -> (Integer, Float) #-}
172 {-# SPECIALIZE truncate :: Float -> Integer #-}
173 {-# SPECIALIZE round :: Float -> Integer #-}
174 {-# SPECIALIZE ceiling :: Float -> Integer #-}
175 {-# SPECIALIZE floor :: Float -> Integer #-}
178 = case (decodeFloat x) of { (m,n) ->
179 let b = floatRadix x in
181 (fromInteger m * fromInteger b ^ n, 0.0)
183 case (quotRem m (b^(negate n))) of { (w,r) ->
184 (fromInteger w, encodeFloat r n)
188 truncate x = case properFraction x of
191 round x = case properFraction x of
193 m = if r < 0.0 then n - 1 else n + 1
194 half_down = abs r - 0.5
196 case (compare half_down 0.0) of
198 EQ -> if even n then n else m
201 ceiling x = case properFraction x of
202 (n,r) -> if r > 0.0 then n + 1 else n
204 floor x = case properFraction x of
205 (n,r) -> if r < 0.0 then n - 1 else n
207 instance Floating Float where
208 pi = 3.141592653589793238
221 (**) x y = powerFloat x y
222 logBase x y = log y / log x
224 asinh x = log (x + sqrt (1.0+x*x))
225 acosh x = log (x + (x+1.0) * sqrt ((x-1.0)/(x+1.0)))
226 atanh x = log ((x+1.0) / sqrt (1.0-x*x))
228 instance RealFloat Float where
229 floatRadix _ = FLT_RADIX -- from float.h
230 floatDigits _ = FLT_MANT_DIG -- ditto
231 floatRange _ = (FLT_MIN_EXP, FLT_MAX_EXP) -- ditto
234 = case decodeFloat# f# of
235 (# exp#, s#, d# #) -> (J# s# d#, I# exp#)
237 encodeFloat (S# i) j = int_encodeFloat# i j
238 encodeFloat (J# s# d#) e = encodeFloat# s# d# e
240 exponent x = case decodeFloat x of
241 (m,n) -> if m == 0 then 0 else n + floatDigits x
243 significand x = case decodeFloat x of
244 (m,_) -> encodeFloat m (negate (floatDigits x))
246 scaleFloat k x = case decodeFloat x of
247 (m,n) -> encodeFloat m (n+k)
248 isNaN x = 0 /= isFloatNaN x
249 isInfinite x = 0 /= isFloatInfinite x
250 isDenormalized x = 0 /= isFloatDenormalized x
251 isNegativeZero x = 0 /= isFloatNegativeZero x
254 instance Show Float where
255 showsPrec x = showSigned showFloat x
256 showList = showList__ (showsPrec 0)
259 %*********************************************************
261 \subsection{Type @Double@}
263 %*********************************************************
266 instance Eq Double where
267 (D# x) == (D# y) = x ==## y
269 instance Ord Double where
270 (D# x) `compare` (D# y) | x <## y = LT
274 (D# x) < (D# y) = x <## y
275 (D# x) <= (D# y) = x <=## y
276 (D# x) >= (D# y) = x >=## y
277 (D# x) > (D# y) = x >## y
279 instance Num Double where
280 (+) x y = plusDouble x y
281 (-) x y = minusDouble x y
282 negate x = negateDouble x
283 (*) x y = timesDouble x y
285 | otherwise = negateDouble x
286 signum x | x == 0.0 = 0
288 | otherwise = negate 1
290 {-# INLINE fromInteger #-}
291 -- See comments with Num Float
292 fromInteger (S# i#) = case (int2Double# i#) of { d# -> D# d# }
293 fromInteger (J# s# d#) = encodeDouble# s# d# 0
296 instance Real Double where
297 toRational x = (m%1)*(b%1)^^n
298 where (m,n) = decodeFloat x
301 instance Fractional Double where
302 (/) x y = divideDouble x y
303 fromRational x = fromRat x
306 instance Floating Double where
307 pi = 3.141592653589793238
310 sqrt x = sqrtDouble x
314 asin x = asinDouble x
315 acos x = acosDouble x
316 atan x = atanDouble x
317 sinh x = sinhDouble x
318 cosh x = coshDouble x
319 tanh x = tanhDouble x
320 (**) x y = powerDouble x y
321 logBase x y = log y / log x
323 asinh x = log (x + sqrt (1.0+x*x))
324 acosh x = log (x + (x+1.0) * sqrt ((x-1.0)/(x+1.0)))
325 atanh x = log ((x+1.0) / sqrt (1.0-x*x))
327 {-# RULES "truncate/Double->Int" truncate = double2Int #-}
328 instance RealFrac Double where
330 {-# SPECIALIZE properFraction :: Double -> (Int, Double) #-}
331 {-# SPECIALIZE round :: Double -> Int #-}
332 {-# SPECIALIZE ceiling :: Double -> Int #-}
333 {-# SPECIALIZE floor :: Double -> Int #-}
335 {-# SPECIALIZE properFraction :: Double -> (Integer, Double) #-}
336 {-# SPECIALIZE truncate :: Double -> Integer #-}
337 {-# SPECIALIZE round :: Double -> Integer #-}
338 {-# SPECIALIZE ceiling :: Double -> Integer #-}
339 {-# SPECIALIZE floor :: Double -> Integer #-}
342 = case (decodeFloat x) of { (m,n) ->
343 let b = floatRadix x in
345 (fromInteger m * fromInteger b ^ n, 0.0)
347 case (quotRem m (b^(negate n))) of { (w,r) ->
348 (fromInteger w, encodeFloat r n)
352 truncate x = case properFraction x of
355 round x = case properFraction x of
357 m = if r < 0.0 then n - 1 else n + 1
358 half_down = abs r - 0.5
360 case (compare half_down 0.0) of
362 EQ -> if even n then n else m
365 ceiling x = case properFraction x of
366 (n,r) -> if r > 0.0 then n + 1 else n
368 floor x = case properFraction x of
369 (n,r) -> if r < 0.0 then n - 1 else n
371 instance RealFloat Double where
372 floatRadix _ = FLT_RADIX -- from float.h
373 floatDigits _ = DBL_MANT_DIG -- ditto
374 floatRange _ = (DBL_MIN_EXP, DBL_MAX_EXP) -- ditto
377 = case decodeDouble# x# of
378 (# exp#, s#, d# #) -> (J# s# d#, I# exp#)
380 encodeFloat (S# i) j = int_encodeDouble# i j
381 encodeFloat (J# s# d#) e = encodeDouble# s# d# e
383 exponent x = case decodeFloat x of
384 (m,n) -> if m == 0 then 0 else n + floatDigits x
386 significand x = case decodeFloat x of
387 (m,_) -> encodeFloat m (negate (floatDigits x))
389 scaleFloat k x = case decodeFloat x of
390 (m,n) -> encodeFloat m (n+k)
392 isNaN x = 0 /= isDoubleNaN x
393 isInfinite x = 0 /= isDoubleInfinite x
394 isDenormalized x = 0 /= isDoubleDenormalized x
395 isNegativeZero x = 0 /= isDoubleNegativeZero x
398 instance Show Double where
399 showsPrec x = showSigned showFloat x
400 showList = showList__ (showsPrec 0)
403 %*********************************************************
405 \subsection{@Enum@ instances}
407 %*********************************************************
409 The @Enum@ instances for Floats and Doubles are slightly unusual.
410 The @toEnum@ function truncates numbers to Int. The definitions
411 of @enumFrom@ and @enumFromThen@ allow floats to be used in arithmetic
412 series: [0,0.1 .. 1.0]. However, roundoff errors make these somewhat
413 dubious. This example may have either 10 or 11 elements, depending on
414 how 0.1 is represented.
416 NOTE: The instances for Float and Double do not make use of the default
417 methods for @enumFromTo@ and @enumFromThenTo@, as these rely on there being
418 a `non-lossy' conversion to and from Ints. Instead we make use of the
419 1.2 default methods (back in the days when Enum had Ord as a superclass)
420 for these (@numericEnumFromTo@ and @numericEnumFromThenTo@ below.)
423 instance Enum Float where
427 fromEnum = fromInteger . truncate -- may overflow
428 enumFrom = numericEnumFrom
429 enumFromTo = numericEnumFromTo
430 enumFromThen = numericEnumFromThen
431 enumFromThenTo = numericEnumFromThenTo
433 instance Enum Double where
437 fromEnum = fromInteger . truncate -- may overflow
438 enumFrom = numericEnumFrom
439 enumFromTo = numericEnumFromTo
440 enumFromThen = numericEnumFromThen
441 enumFromThenTo = numericEnumFromThenTo
445 %*********************************************************
447 \subsection{Printing floating point}
449 %*********************************************************
453 showFloat :: (RealFloat a) => a -> ShowS
454 showFloat x = showString (formatRealFloat FFGeneric Nothing x)
456 -- These are the format types. This type is not exported.
458 data FFFormat = FFExponent | FFFixed | FFGeneric
460 formatRealFloat :: (RealFloat a) => FFFormat -> Maybe Int -> a -> String
461 formatRealFloat fmt decs x
463 | isInfinite x = if x < 0 then "-Infinity" else "Infinity"
464 | x < 0 || isNegativeZero x = '-':doFmt fmt (floatToDigits (toInteger base) (-x))
465 | otherwise = doFmt fmt (floatToDigits (toInteger base) x)
469 doFmt format (is, e) =
470 let ds = map intToDigit is in
473 doFmt (if e < 0 || e > 7 then FFExponent else FFFixed)
478 let show_e' = show (e-1) in
481 [d] -> d : ".0e" ++ show_e'
482 (d:ds') -> d : '.' : ds' ++ "e" ++ show_e'
484 let dec' = max dec 1 in
486 [0] -> '0' :'.' : take dec' (repeat '0') ++ "e0"
489 (ei,is') = roundTo base (dec'+1) is
490 (d:ds') = map intToDigit (if ei > 0 then init is' else is')
492 d:'.':ds' ++ 'e':show (e-1+ei)
495 mk0 ls = case ls of { "" -> "0" ; _ -> ls}
500 f 0 s rs = mk0 (reverse s) ++ '.':mk0 rs
501 f n s "" = f (n-1) ('0':s) ""
502 f n s (r:rs) = f (n-1) (r:s) rs
506 let dec' = max dec 0 in
509 (ei,is') = roundTo base (dec' + e) is
510 (ls,rs) = splitAt (e+ei) (map intToDigit is')
512 mk0 ls ++ (if null rs then "" else '.':rs)
515 (ei,is') = roundTo base dec' (replicate (-e) 0 ++ is)
516 d:ds' = map intToDigit (if ei > 0 then is' else 0:is')
521 roundTo :: Int -> Int -> [Int] -> (Int,[Int])
529 f n [] = (0, replicate n 0)
530 f 0 (x:_) = (if x >= b2 then 1 else 0, [])
532 | i' == base = (1,0:ds)
533 | otherwise = (0,i':ds)
539 -- Based on "Printing Floating-Point Numbers Quickly and Accurately"
540 -- by R.G. Burger and R.K. Dybvig in PLDI 96.
541 -- This version uses a much slower logarithm estimator. It should be improved.
543 -- This function returns a list of digits (Ints in [0..base-1]) and an
546 floatToDigits :: (RealFloat a) => Integer -> a -> ([Int], Int)
547 floatToDigits _ 0 = ([0], 0)
548 floatToDigits base x =
550 (f0, e0) = decodeFloat x
551 (minExp0, _) = floatRange x
554 minExp = minExp0 - p -- the real minimum exponent
555 -- Haskell requires that f be adjusted so denormalized numbers
556 -- will have an impossibly low exponent. Adjust for this.
558 let n = minExp - e0 in
559 if n > 0 then (f0 `div` (b^n), e0+n) else (f0, e0)
564 (f*be*b*2, 2*b, be*b, b)
568 if e > minExp && f == b^(p-1) then
569 (f*b*2, b^(-e+1)*2, b, 1)
571 (f*2, b^(-e)*2, 1, 1)
575 if b == 2 && base == 10 then
576 -- logBase 10 2 is slightly bigger than 3/10 so
577 -- the following will err on the low side. Ignoring
578 -- the fraction will make it err even more.
579 -- Haskell promises that p-1 <= logBase b f < p.
580 (p - 1 + e0) * 3 `div` 10
582 ceiling ((log (fromInteger (f+1)) +
583 fromInteger (int2Integer e) * log (fromInteger b)) /
584 log (fromInteger base))
585 --WAS: fromInt e * log (fromInteger b))
589 if r + mUp <= expt base n * s then n else fixup (n+1)
591 if expt base (-n) * (r + mUp) <= s then n else fixup (n+1)
595 gen ds rn sN mUpN mDnN =
597 (dn, rn') = (rn * base) `divMod` sN
601 case (rn' < mDnN', rn' + mUpN' > sN) of
602 (True, False) -> dn : ds
603 (False, True) -> dn+1 : ds
604 (True, True) -> if rn' * 2 < sN then dn : ds else dn+1 : ds
605 (False, False) -> gen (dn:ds) rn' sN mUpN' mDnN'
609 gen [] r (s * expt base k) mUp mDn
611 let bk = expt base (-k) in
612 gen [] (r * bk) s (mUp * bk) (mDn * bk)
614 (map fromIntegral (reverse rds), k)
619 %*********************************************************
621 \subsection{Converting from a Rational to a RealFloat
623 %*********************************************************
625 [In response to a request for documentation of how fromRational works,
626 Joe Fasel writes:] A quite reasonable request! This code was added to
627 the Prelude just before the 1.2 release, when Lennart, working with an
628 early version of hbi, noticed that (read . show) was not the identity
629 for floating-point numbers. (There was a one-bit error about half the
630 time.) The original version of the conversion function was in fact
631 simply a floating-point divide, as you suggest above. The new version
632 is, I grant you, somewhat denser.
634 Unfortunately, Joe's code doesn't work! Here's an example:
636 main = putStr (shows (1.82173691287639817263897126389712638972163e-300::Double) "\n")
641 1.8217369128763981e-300
646 fromRat :: (RealFloat a) => Rational -> a
650 -- If the exponent of the nearest floating-point number to x
651 -- is e, then the significand is the integer nearest xb^(-e),
652 -- where b is the floating-point radix. We start with a good
653 -- guess for e, and if it is correct, the exponent of the
654 -- floating-point number we construct will again be e. If
655 -- not, one more iteration is needed.
657 f e = if e' == e then y else f e'
658 where y = encodeFloat (round (x * (1 % b)^^e)) e
659 (_,e') = decodeFloat y
662 -- We obtain a trial exponent by doing a floating-point
663 -- division of x's numerator by its denominator. The
664 -- result of this division may not itself be the ultimate
665 -- result, because of an accumulation of three rounding
668 (s,e) = decodeFloat (fromInteger (numerator x) `asTypeOf` x'
669 / fromInteger (denominator x))
672 Now, here's Lennart's code (which works)
675 {-# SPECIALISE fromRat ::
677 Rational -> Float #-}
678 fromRat :: (RealFloat a) => Rational -> a
680 | x == 0 = encodeFloat 0 0 -- Handle exceptional cases
681 | x < 0 = - fromRat' (-x) -- first.
682 | otherwise = fromRat' x
684 -- Conversion process:
685 -- Scale the rational number by the RealFloat base until
686 -- it lies in the range of the mantissa (as used by decodeFloat/encodeFloat).
687 -- Then round the rational to an Integer and encode it with the exponent
688 -- that we got from the scaling.
689 -- To speed up the scaling process we compute the log2 of the number to get
690 -- a first guess of the exponent.
692 fromRat' :: (RealFloat a) => Rational -> a
694 where b = floatRadix r
696 (minExp0, _) = floatRange r
697 minExp = minExp0 - p -- the real minimum exponent
698 xMin = toRational (expt b (p-1))
699 xMax = toRational (expt b p)
700 p0 = (integerLogBase b (numerator x) - integerLogBase b (denominator x) - p) `max` minExp
701 f = if p0 < 0 then 1 % expt b (-p0) else expt b p0 % 1
702 (x', p') = scaleRat (toRational b) minExp xMin xMax p0 (x / f)
703 r = encodeFloat (round x') p'
705 -- Scale x until xMin <= x < xMax, or p (the exponent) <= minExp.
706 scaleRat :: Rational -> Int -> Rational -> Rational -> Int -> Rational -> (Rational, Int)
707 scaleRat b minExp xMin xMax p x
708 | p <= minExp = (x, p)
709 | x >= xMax = scaleRat b minExp xMin xMax (p+1) (x/b)
710 | x < xMin = scaleRat b minExp xMin xMax (p-1) (x*b)
713 -- Exponentiation with a cache for the most common numbers.
714 minExpt, maxExpt :: Int
718 expt :: Integer -> Int -> Integer
720 if base == 2 && n >= minExpt && n <= maxExpt then
725 expts :: Array Int Integer
726 expts = array (minExpt,maxExpt) [(n,2^n) | n <- [minExpt .. maxExpt]]
728 -- Compute the (floor of the) log of i in base b.
729 -- Simplest way would be just divide i by b until it's smaller then b, but that would
730 -- be very slow! We are just slightly more clever.
731 integerLogBase :: Integer -> Integer -> Int
734 | otherwise = doDiv (i `div` (b^l)) l
736 -- Try squaring the base first to cut down the number of divisions.
737 l = 2 * integerLogBase (b*b) i
739 doDiv :: Integer -> Int -> Int
742 | otherwise = doDiv (x `div` b) (y+1)
747 %*********************************************************
749 \subsection{Floating point numeric primops}
751 %*********************************************************
753 Definitions of the boxed PrimOps; these will be
754 used in the case of partial applications, etc.
757 plusFloat, minusFloat, timesFloat, divideFloat :: Float -> Float -> Float
758 plusFloat (F# x) (F# y) = F# (plusFloat# x y)
759 minusFloat (F# x) (F# y) = F# (minusFloat# x y)
760 timesFloat (F# x) (F# y) = F# (timesFloat# x y)
761 divideFloat (F# x) (F# y) = F# (divideFloat# x y)
763 negateFloat :: Float -> Float
764 negateFloat (F# x) = F# (negateFloat# x)
766 gtFloat, geFloat, eqFloat, neFloat, ltFloat, leFloat :: Float -> Float -> Bool
767 gtFloat (F# x) (F# y) = gtFloat# x y
768 geFloat (F# x) (F# y) = geFloat# x y
769 eqFloat (F# x) (F# y) = eqFloat# x y
770 neFloat (F# x) (F# y) = neFloat# x y
771 ltFloat (F# x) (F# y) = ltFloat# x y
772 leFloat (F# x) (F# y) = leFloat# x y
774 float2Int :: Float -> Int
775 float2Int (F# x) = I# (float2Int# x)
777 int2Float :: Int -> Float
778 int2Float (I# x) = F# (int2Float# x)
780 expFloat, logFloat, sqrtFloat :: Float -> Float
781 sinFloat, cosFloat, tanFloat :: Float -> Float
782 asinFloat, acosFloat, atanFloat :: Float -> Float
783 sinhFloat, coshFloat, tanhFloat :: Float -> Float
784 expFloat (F# x) = F# (expFloat# x)
785 logFloat (F# x) = F# (logFloat# x)
786 sqrtFloat (F# x) = F# (sqrtFloat# x)
787 sinFloat (F# x) = F# (sinFloat# x)
788 cosFloat (F# x) = F# (cosFloat# x)
789 tanFloat (F# x) = F# (tanFloat# x)
790 asinFloat (F# x) = F# (asinFloat# x)
791 acosFloat (F# x) = F# (acosFloat# x)
792 atanFloat (F# x) = F# (atanFloat# x)
793 sinhFloat (F# x) = F# (sinhFloat# x)
794 coshFloat (F# x) = F# (coshFloat# x)
795 tanhFloat (F# x) = F# (tanhFloat# x)
797 powerFloat :: Float -> Float -> Float
798 powerFloat (F# x) (F# y) = F# (powerFloat# x y)
800 -- definitions of the boxed PrimOps; these will be
801 -- used in the case of partial applications, etc.
803 plusDouble, minusDouble, timesDouble, divideDouble :: Double -> Double -> Double
804 plusDouble (D# x) (D# y) = D# (x +## y)
805 minusDouble (D# x) (D# y) = D# (x -## y)
806 timesDouble (D# x) (D# y) = D# (x *## y)
807 divideDouble (D# x) (D# y) = D# (x /## y)
809 negateDouble :: Double -> Double
810 negateDouble (D# x) = D# (negateDouble# x)
812 gtDouble, geDouble, eqDouble, neDouble, leDouble, ltDouble :: Double -> Double -> Bool
813 gtDouble (D# x) (D# y) = x >## y
814 geDouble (D# x) (D# y) = x >=## y
815 eqDouble (D# x) (D# y) = x ==## y
816 neDouble (D# x) (D# y) = x /=## y
817 ltDouble (D# x) (D# y) = x <## y
818 leDouble (D# x) (D# y) = x <=## y
820 double2Int :: Double -> Int
821 double2Int (D# x) = I# (double2Int# x)
823 int2Double :: Int -> Double
824 int2Double (I# x) = D# (int2Double# x)
826 double2Float :: Double -> Float
827 double2Float (D# x) = F# (double2Float# x)
829 float2Double :: Float -> Double
830 float2Double (F# x) = D# (float2Double# x)
832 expDouble, logDouble, sqrtDouble :: Double -> Double
833 sinDouble, cosDouble, tanDouble :: Double -> Double
834 asinDouble, acosDouble, atanDouble :: Double -> Double
835 sinhDouble, coshDouble, tanhDouble :: Double -> Double
836 expDouble (D# x) = D# (expDouble# x)
837 logDouble (D# x) = D# (logDouble# x)
838 sqrtDouble (D# x) = D# (sqrtDouble# x)
839 sinDouble (D# x) = D# (sinDouble# x)
840 cosDouble (D# x) = D# (cosDouble# x)
841 tanDouble (D# x) = D# (tanDouble# x)
842 asinDouble (D# x) = D# (asinDouble# x)
843 acosDouble (D# x) = D# (acosDouble# x)
844 atanDouble (D# x) = D# (atanDouble# x)
845 sinhDouble (D# x) = D# (sinhDouble# x)
846 coshDouble (D# x) = D# (coshDouble# x)
847 tanhDouble (D# x) = D# (tanhDouble# x)
849 powerDouble :: Double -> Double -> Double
850 powerDouble (D# x) (D# y) = D# (x **## y)
854 foreign import ccall "__encodeFloat" unsafe
855 encodeFloat# :: Int# -> ByteArray# -> Int -> Float
856 foreign import ccall "__int_encodeFloat" unsafe
857 int_encodeFloat# :: Int# -> Int -> Float
860 foreign import ccall "isFloatNaN" unsafe isFloatNaN :: Float -> Int
861 foreign import ccall "isFloatInfinite" unsafe isFloatInfinite :: Float -> Int
862 foreign import ccall "isFloatDenormalized" unsafe isFloatDenormalized :: Float -> Int
863 foreign import ccall "isFloatNegativeZero" unsafe isFloatNegativeZero :: Float -> Int
866 foreign import ccall "__encodeDouble" unsafe
867 encodeDouble# :: Int# -> ByteArray# -> Int -> Double
868 foreign import ccall "__int_encodeDouble" unsafe
869 int_encodeDouble# :: Int# -> Int -> Double
871 foreign import ccall "isDoubleNaN" unsafe isDoubleNaN :: Double -> Int
872 foreign import ccall "isDoubleInfinite" unsafe isDoubleInfinite :: Double -> Int
873 foreign import ccall "isDoubleDenormalized" unsafe isDoubleDenormalized :: Double -> Int
874 foreign import ccall "isDoubleNegativeZero" unsafe isDoubleNegativeZero :: Double -> Int
877 %*********************************************************
879 \subsection{Coercion rules}
881 %*********************************************************
885 "fromIntegral/Int->Float" fromIntegral = int2Float
886 "fromIntegral/Int->Double" fromIntegral = int2Double
887 "realToFrac/Float->Float" realToFrac = id :: Float -> Float
888 "realToFrac/Float->Double" realToFrac = float2Double
889 "realToFrac/Double->Float" realToFrac = double2Float
890 "realToFrac/Double->Double" realToFrac = id :: Double -> Double