Data/Floating/Instances.hs

   1 {-# LANGUAGE ForeignFunctionInterface, MagicHash #-}
   2 module Data.Floating.Instances () where
   3
   4 import Prelude hiding (Ord(..), Double)
   5 import Foreign.C
   6
   7 import Data.Floating.Classes
   8 import Data.Floating.Double
   9 import Data.Floating.Types
  10 import Data.Floating.CMath
  11
  12 import Data.Poset
  13 import GHC.Prim
  14
  15 foreign import ccall unsafe "double_compare"
  16     double_compare :: CDouble -> CDouble -> CInt
  17
  18 instance Poset Double where
  19     compare a b = toEnum . fromIntegral $ double_compare a' b' where
  20         a' = toFloating a
  21         b' = toFloating b
  22     D# x <  D# y = x <##  y
  23     D# x <= D# y = x <=## y
  24     D# x >= D# y = x >=## y
  25     D# x >  D# y = x >##  y
  26
  27 instance Sortable Double where
  28     isSignificant = not . ((== FPNaN) . classify)
  29     max = libmDouble2 c_fmax
  30     min = libmDouble2 c_fmin