Merge remote-tracking branch 'origin/master' into wip/new-flatten-skolems-Aug14

5 files changed, 25 insertions, 19 deletions

diff --git a/libraries/base/Data/Bool.hs b/libraries/base/Data/Bool.hs
index ace5acf447..15371982ea 100644
--- a/libraries/base/Data/Bool.hs
+++ b/libraries/base/Data/Bool.hs
@@ -37,7 +37,7 @@ import GHC.Base
 --
 --   /Since: 4.7.0.0/
 --
---   __Examples__:
+--   ==== __Examples__
 --
 --   Basic usage:
 --
diff --git a/libraries/base/Data/Functor.hs b/libraries/base/Data/Functor.hs
index 010ab502e6..0896947417 100644
--- a/libraries/base/Data/Functor.hs
+++ b/libraries/base/Data/Functor.hs
@@ -33,7 +33,7 @@ infixl 4 <$>
 
 -- | An infix synonym for 'fmap'.
 --
---   __Examples__:
+--   ==== __Examples__
 --
 --   Convert from a 'Maybe' 'Int' to a 'Maybe' 'String' using 'show':
 --
@@ -70,7 +70,7 @@ infixl 4 $>
 --
 --   /Since: 4.7.0.0/
 --
---   __Examples__:
+--   ==== __Examples__
 --
 --   Replace the contents of a 'Maybe' 'Int' with a constant 'String':
 --
@@ -103,7 +103,7 @@ infixl 4 $>
 -- | @'void' value@ discards or ignores the result of evaluation, such
 --   as the return value of an 'IO' action.
 --
---   __Examples__:
+--   ==== __Examples__
 --
 --   Replace the contents of a 'Maybe' 'Int' with unit:
 --
diff --git a/libraries/base/GHC/List.lhs b/libraries/base/GHC/List.lhs
index 89c33d66f2..6a930333e0 100644
--- a/libraries/base/GHC/List.lhs
+++ b/libraries/base/GHC/List.lhs
@@ -533,23 +533,29 @@ take n _      | n <= 0 =  []
 take _ []              =  []
 take n (x:xs)          =  x : take (n-1) xs
 #else
--- We always want to inline this to take advantage of a known
--- length argument sign.
-{-# INLINE take #-}
+
+{- We always want to inline this to take advantage of a known length argument
+sign. Note, however, that it's important for the RULES to grab take, rather
+than trying to INLINE take immediately and then letting the RULES grab
+unsafeTake. Presumably the latter approach doesn't grab it early enough; it led
+to an allocation regression in nofib/fft2. -}
+{-# INLINE [1] take #-}
 take n xs | 0 < n     = unsafeTake n xs
           | otherwise = []
 
 -- A version of take that takes the whole list if it's given an argument less
--- than 1. This does the same thing as the fold version.
+-- than 1.
 {-# NOINLINE [1] unsafeTake #-}
 unsafeTake :: Int -> [a] -> [a]
-unsafeTake _  []     = []
-unsafeTake 1  (x: _) = [x]
-unsafeTake m  (x:xs) = x : unsafeTake (m - 1) xs
+unsafeTake !_  []     = []
+unsafeTake 1   (x: _) = [x]
+unsafeTake m   (x:xs) = x : unsafeTake (m - 1) xs
 
 {-# RULES
-"unsafeTake"     [~1] forall n xs . unsafeTake n xs =
-  build (\c nil -> foldr (takeFB c nil) (flipSeqTake nil) xs n)
+"take"     [~1] forall n xs . take n xs =
+  build (\c nil -> if 0 < n
+                   then foldr (takeFB c nil) (flipSeqTake nil) xs n
+                   else nil)
 "unsafeTakeList"  [1] forall n xs . foldr (takeFB (:) []) (flipSeqTake []) xs n
                                         = unsafeTake n xs
  #-}
@@ -558,8 +564,8 @@ unsafeTake m  (x:xs) = x : unsafeTake (m - 1) xs
 -- Just flip seq, specialized to Int, but not inlined too early.
 -- It's important to force the numeric argument here, even though
 -- it's not used. Otherwise, take n [] doesn't force n. This is
--- bad for strictness analysis and unboxing, and leads to test suite
--- performance regressions.
+-- bad for strictness analysis and unboxing, and leads to increased
+-- allocation in T7257.
 flipSeqTake :: a -> Int -> a
 flipSeqTake x !_n = x
 
@@ -602,9 +608,9 @@ drop n ls
     -- A version of drop that drops the whole list if given an argument
     -- less than 1
     unsafeDrop :: Int -> [a] -> [a]
-    unsafeDrop _ []     = []
-    unsafeDrop 1 (_:xs) = xs
-    unsafeDrop m (_:xs) = unsafeDrop (m - 1) xs
+    unsafeDrop !_ []     = []
+    unsafeDrop 1  (_:xs) = xs
+    unsafeDrop m  (_:xs) = unsafeDrop (m - 1) xs
 #endif
 
 -- | 'splitAt' @n xs@ returns a tuple where first element is @xs@ prefix of
diff --git a/libraries/base/Text/Printf.hs b/libraries/base/Text/Printf.hs
index d20e077b95..7cf4204e50 100644
--- a/libraries/base/Text/Printf.hs
+++ b/libraries/base/Text/Printf.hs
@@ -246,7 +246,7 @@ import System.IO
 -- * Haskell 'printf' will place a zero after a decimal point when
 --   possible.
 --
--- Examples:
+-- ==== __Examples__
 --
 -- >   > printf "%d\n" (23::Int)
 -- >   23
diff --git a/utils/haddock b/utils/haddock
-Subproject c3f27a96bd2a1ec14f441c72a2df95c16c2c540
+Subproject 3fb325a2ca6b6397905116024922d079447a2e0