X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=GHC%2FReal.lhs;h=fdce8b94361b7b91cd5836853eb94e69a783ea2d;hb=c72dc997c63a629f6a2a9f82168ac93dda9ee09e;hp=da6053eb73c2e69db43f9c141c7fa2373b88cb66;hpb=8827985d7ce902bfc916e4168049c9a46a1d7fe8;p=ghc-base.git

diff --git a/GHC/Real.lhs b/GHC/Real.lhs
index da6053e..fdce8b9 100644
--- a/GHC/Real.lhs
+++ b/GHC/Real.lhs
@@ -4,7 +4,7 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  GHC.Real
--- Copyright   :  (c) The FFI Task Force, 1994-2002
+-- Copyright   :  (c) The University of Glasgow, 1994-2002
 -- License     :  see libraries/base/LICENSE
 -- 
 -- Maintainer  :  cvs-ghc@haskell.org
@@ -24,6 +24,7 @@ import GHC.Num
 import GHC.List
 import GHC.Enum
 import GHC.Show
+import GHC.Err
 
 infixr 8  ^, ^^
 infixl 7  /, `quot`, `rem`, `div`, `mod`
@@ -173,7 +174,8 @@ class  (Real a, Fractional a) => RealFrac a  where
     properFraction      :: (Integral b) => a -> (b,a)
     -- | @'truncate' x@ returns the integer nearest @x@ between zero and @x@
     truncate            :: (Integral b) => a -> b
-    -- | @'round' x@ returns the nearest integer to @x@
+    -- | @'round' x@ returns the nearest integer to @x@;
+    --   the even integer if @x@ is equidistant between two integers
     round               :: (Integral b) => a -> b
     -- | @'ceiling' x@ returns the least integer not less than @x@
     ceiling             :: (Integral b) => a -> b
@@ -447,6 +449,7 @@ lcm _ 0         =  0
 lcm 0 _         =  0
 lcm x y         =  abs ((x `quot` (gcd x y)) * y)
 
+#ifdef OPTIMISE_INTEGER_GCD_LCM
 {-# RULES
 "gcd/Int->Int->Int"             gcd = gcdInt
 "gcd/Integer->Integer->Integer" gcd = gcdInteger'
@@ -460,6 +463,11 @@ gcdInteger' :: Integer -> Integer -> Integer
 gcdInteger' 0 0 = error "GHC.Real.gcdInteger': gcd 0 0 is undefined"
 gcdInteger' a b = gcdInteger a b
 
+gcdInt :: Int -> Int -> Int
+gcdInt 0 0 = error "GHC.Real.gcdInt: gcd 0 0 is undefined"
+gcdInt a b = fromIntegral (gcdInteger (fromIntegral a) (fromIntegral b))
+#endif
+
 integralEnumFrom :: (Integral a, Bounded a) => a -> [a]
 integralEnumFrom n = map fromInteger [toInteger n .. toInteger (maxBound `asTypeOf` n)]