compiler: de-lhs utils/

Signed-off-by: Austin Seipp <austin@well-typed.com>

1 files changed, 46 insertions, 0 deletions

diff --git a/compiler/utils/FastFunctions.hs b/compiler/utils/FastFunctions.hs
new file mode 100644
index 0000000000..140e42949a
--- /dev/null
+++ b/compiler/utils/FastFunctions.hs
@@ -0,0 +1,46 @@
+{-
+Z%
+(c) The University of Glasgow, 2000-2006
+
+\section{Fast functions}
+-}
+
+{-# LANGUAGE CPP, MagicHash, UnboxedTuples #-}
+
+module FastFunctions (
+    unsafeChr, inlinePerformIO, unsafeDupableInterleaveIO,
+    indexWord8OffFastPtr,
+    indexWord8OffFastPtrAsFastChar, indexWord8OffFastPtrAsFastInt,
+    global, Global
+  ) where
+
+#include "HsVersions.h"
+
+import FastTypes
+import Data.IORef
+import System.IO.Unsafe
+
+import GHC.Exts
+import GHC.Word
+import GHC.Base (unsafeChr)
+
+import GHC.IO   (IO(..), unsafeDupableInterleaveIO)
+
+-- Just like unsafePerformIO, but we inline it.
+{-# INLINE inlinePerformIO #-}
+inlinePerformIO :: IO a -> a
+inlinePerformIO (IO m) = case m realWorld# of (# _, r #)   -> r
+
+indexWord8OffFastPtr p i = W8# (indexWord8OffAddr# p i)
+indexWord8OffFastPtrAsFastChar p i = indexCharOffAddr# p i
+indexWord8OffFastPtrAsFastInt p i = word2Int# (indexWord8OffAddr# p i)
+-- or ord# (indexCharOffAddr# p i)
+
+--just so we can refer to the type clearly in a macro
+type Global a = IORef a
+global :: a -> Global a
+global a = unsafePerformIO (newIORef a)
+
+indexWord8OffFastPtr :: FastPtr Word8 -> FastInt -> Word8
+indexWord8OffFastPtrAsFastChar :: FastPtr Word8 -> FastInt -> FastChar
+indexWord8OffFastPtrAsFastInt :: FastPtr Word8 -> FastInt -> FastInt