Reorganisation of the source tree

Most of the other users of the fptools build system have migrated to
Cabal, and with the move to darcs we can now flatten the source tree
without losing history, so here goes.

The main change is that the ghc/ subdir is gone, and most of what it
contained is now at the top level.  The build system now makes no
pretense at being multi-project, it is just the GHC build system.

No doubt this will break many things, and there will be a period of
instability while we fix the dependencies.  A straightforward build
should work, but I haven't yet fixed binary/source distributions.
Changes to the Building Guide will follow, too.

1 files changed, 205 insertions, 0 deletions

diff --git a/compiler/utils/BitSet.lhs b/compiler/utils/BitSet.lhs
new file mode 100644
index 0000000000..a108136af3
--- /dev/null
+++ b/compiler/utils/BitSet.lhs
@@ -0,0 +1,205 @@
+%
+% (c) The GRASP Project, Glasgow University, 1994-1998
+%
+\section[BitSet]{An implementation of very small sets}
+
+Bit sets are a fast implementation of sets of integers ranging from 0
+to one less than the number of bits in a machine word (typically 31).
+If any element exceeds the maximum value for a particular machine
+architecture, the results of these operations are undefined.  You have
+been warned.  If you put any safety checks in this code, I will have
+to kill you.
+
+Note: the Yale Haskell implementation won't provide a full 32 bits.
+However, if you can handle the performance loss, you could change to
+Integer and get virtually unlimited sets.
+
+\begin{code}
+
+module BitSet (
+	BitSet,		-- abstract type
+	mkBS, listBS, emptyBS, unitBS,
+	unionBS, minusBS, intBS
+    ) where
+
+#include "HsVersions.h"
+
+#ifdef __GLASGOW_HASKELL__
+import GLAEXTS
+-- nothing to import
+#elif defined(__YALE_HASKELL__)
+{-hide import from mkdependHS-}
+import
+	LogOpPrims
+#else
+{-hide import from mkdependHS-}
+import
+	Word
+#endif
+
+#ifdef __GLASGOW_HASKELL__
+
+data BitSet = MkBS Word#
+
+emptyBS :: BitSet
+emptyBS = MkBS (int2Word# 0#)
+
+mkBS :: [Int] -> BitSet
+mkBS xs = foldr (unionBS . unitBS) emptyBS xs
+
+unitBS :: Int -> BitSet
+unitBS x = case x of
+#if __GLASGOW_HASKELL__ >= 503
+    I# i# -> MkBS ((int2Word# 1#) `uncheckedShiftL#` i#)
+#else
+    I# i# -> MkBS ((int2Word# 1#) `shiftL#` i#)
+#endif
+
+unionBS :: BitSet -> BitSet -> BitSet
+unionBS (MkBS x#) (MkBS y#) = MkBS (x# `or#` y#)
+
+minusBS :: BitSet -> BitSet -> BitSet
+minusBS (MkBS x#) (MkBS y#) = MkBS (x# `and#` (not# y#))
+
+#if 0
+-- not used in GHC
+isEmptyBS :: BitSet -> Bool
+isEmptyBS (MkBS s#)
+  = case word2Int# s# of
+    	0# -> True
+    	_  -> False
+
+intersectBS :: BitSet -> BitSet -> BitSet
+intersectBS (MkBS x#) (MkBS y#) = MkBS (x# `and#` y#)
+
+elementBS :: Int -> BitSet -> Bool
+elementBS x (MkBS s#) = case x of
+    I# i# -> case word2Int# (((int2Word# 1#) `shiftL#` i#) `and#` s#) of
+    	    	    0# -> False
+    	    	    _  -> True
+#endif
+
+listBS :: BitSet -> [Int]
+listBS s = listify s 0
+    where listify (MkBS s#) n =
+    	    case word2Int# s# of
+    	        0# -> []
+    	        _  -> let s' = (MkBS (s# `shiftr` 1#))
+    	    	    	  more = listify s' (n + 1)
+    	    	      in case word2Int# (s# `and#` (int2Word# 1#)) of
+    	    	    	  0# -> more
+    	    	    	  _  -> n : more
+#if __GLASGOW_HASKELL__ >= 503
+	  shiftr x y = uncheckedShiftRL# x y
+#else
+	  shiftr x y = shiftRL# x y
+#endif
+
+-- intBS is a bit naughty.
+intBS :: BitSet -> Int
+intBS (MkBS w#) = I# (word2Int# w#)
+
+#elif defined(__YALE_HASKELL__)
+
+data BitSet = MkBS Int
+
+emptyBS :: BitSet
+emptyBS = MkBS 0
+
+mkBS :: [Int] -> BitSet
+mkBS xs = foldr (unionBS . unitBS) emptyBS xs
+
+unitBS :: Int -> BitSet
+unitBS x = MkBS (1 `ashInt` x)
+
+unionBS :: BitSet -> BitSet -> BitSet
+unionBS (MkBS x) (MkBS y) = MkBS (x `logiorInt` y)
+
+#if 0
+-- not used in GHC
+isEmptyBS :: BitSet -> Bool
+isEmptyBS (MkBS s)
+  = case s of
+    	0 -> True
+    	_ -> False
+
+intersectBS :: BitSet -> BitSet -> BitSet
+intersectBS (MkBS x) (MkBS y) = MkBS (x `logandInt` y)
+
+elementBS :: Int -> BitSet -> Bool
+elementBS x (MkBS s)
+  = case logbitpInt x s of
+    	0 -> False
+    	_ -> True
+#endif
+
+minusBS :: BitSet -> BitSet -> BitSet
+minusBS (MkBS x) (MkBS y) = MkBS (x `logandc2Int` y)
+
+-- rewritten to avoid right shifts (which would give nonsense on negative
+-- values.
+listBS :: BitSet -> [Int]
+listBS (MkBS s) = listify s 0 1
+    where listify s n m =
+    	    case s of
+    	        0 -> []
+    	        _ -> let n' = n+1; m' = m+m in
+		     case logbitpInt s m of
+		     0 -> listify s n' m'
+		     _ -> n : listify (s `logandc2Int` m) n' m'
+
+#else	/* HBC, perhaps? */
+
+data BitSet = MkBS Word
+
+emptyBS :: BitSet
+emptyBS = MkBS 0
+
+mkBS :: [Int] -> BitSet
+mkBS xs = foldr (unionBS . unitBS) emptyBS xs
+
+unitBS :: Int -> BitSet
+unitBS x = MkBS (1 `bitLsh` x)
+
+unionBS :: BitSet -> BitSet -> BitSet
+unionBS (MkBS x) (MkBS y) = MkBS (x `bitOr` y)
+
+#if 0
+-- not used in GHC
+isEmptyBS :: BitSet -> Bool
+isEmptyBS (MkBS s)
+  = case s of
+    	0 -> True
+    	_ -> False
+
+intersectBS :: BitSet -> BitSet -> BitSet
+intersectBS (MkBS x) (MkBS y) = MkBS (x `bitAnd` y)
+
+elementBS :: Int -> BitSet -> Bool
+elementBS x (MkBS s)
+  = case (1 `bitLsh` x) `bitAnd` s of
+    	0 -> False
+    	_ -> True
+#endif
+
+minusBS :: BitSet -> BitSet -> BitSet
+minusBS (MkBS x) (MkBS y) = MkBS (x `bitAnd` (bitCompl y))
+
+listBS :: BitSet -> [Int]
+listBS (MkBS s) = listify s 0
+    where listify s n =
+    	    case s of
+    	        0 -> []
+    	        _ -> let s' = s `bitRsh` 1
+    	    	         more = listify s' (n + 1)
+    	    	     in case (s `bitAnd` 1) of
+    	    	    	    0 -> more
+    	    	    	    _ -> n : more
+
+#endif
+
+\end{code}
+
+
+
+