remove conflicting import for nhc98

[haskell-directory.git] / GHC / Float.lhs

diff --git a/GHC/Float.lhs b/GHC/Float.lhs
index 9831ec9..cac8c0a 100644 (file)
--- a/GHC/Float.lhs
+++ b/GHC/Float.lhs
@@ -16,6 +16,7 @@
 
 #include "ieee-flpt.h"
 
+-- #hide
 module GHC.Float( module GHC.Float, Float#, Double# )  where
 
 import Data.Maybe
@@ -188,10 +189,13 @@ instance  Num Float  where
             | otherwise = negate 1
 
     {-# INLINE fromInteger #-}
-    fromInteger n      =  encodeFloat n 0
-       -- It's important that encodeFloat inlines here, and that 
-       -- fromInteger in turn inlines,
-       -- so that if fromInteger is applied to an (S# i) the right thing happens
+    fromInteger (S# i#)    = case (int2Float# i#) of { d# -> F# d# }
+    fromInteger (J# s# d#) = encodeFloat# s# d# 0
+       -- previous code: fromInteger n = encodeFloat n 0
+       -- doesn't work too well, because encodeFloat is defined in
+       -- terms of ccalls which can never be simplified away.  We
+       -- want simple literals like (fromInteger 3 :: Float) to turn
+       -- into (F# 3.0), hence the special case for S# here.
 
 instance  Real Float  where
     toRational x       =  (m%1)*(b%1)^^n