[commit: base] master: Fix bug in popCountDefault. Fixes #5872 (f4cc96c)

[Johan Tibell]

Repository : ssh://darcs.haskell.org//srv/darcs/packages/base

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/f4cc96cd1a9d78ee250c8f26797e0b72a8008a1c

>---------------------------------------------------------------

commit f4cc96cd1a9d78ee250c8f26797e0b72a8008a1c
Author: Johan Tibell <johan.tibell at gmail.com>
Date:   Tue Feb 14 09:38:19 2012 -0800

    Fix bug in popCountDefault. Fixes #5872
    
    Also add an INLINABLE pragma so that the function can be specialized at
    the call site.

>---------------------------------------------------------------

 Data/Bits.hs |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/Data/Bits.hs b/Data/Bits.hs
index cac9128..496f592 100644
--- a/Data/Bits.hs
+++ b/Data/Bits.hs
@@ -257,7 +257,8 @@ popCountDefault :: (Bits a, Num a) => a -> Int
 popCountDefault = go 0
  where
    go !c 0 = c
-   go c w = go (c+1) (w .&. w - 1) -- clear the least significant
+   go c w = go (c+1) (w .&. (w - 1)) -- clear the least significant
+{-# INLINABLE popCountDefault #-}
 
 instance Bits Int where
     {-# INLINE shift #-}