X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Futils%2FDigraph.lhs;h=d8f6220658945fa5a24cb2acf846f7096a802563;hb=abbc5a0be1df84a33015470319062ed7a3aa3153;hp=b904fff79373831d251e4fbf7ac545176c49442e;hpb=be33dbc967b4915cfdb0307ae1b7ae3cee651b8c;p=ghc-hetmet.git

diff --git a/ghc/compiler/utils/Digraph.lhs b/ghc/compiler/utils/Digraph.lhs
index b904fff..d8f6220 100644
--- a/ghc/compiler/utils/Digraph.lhs
+++ b/ghc/compiler/utils/Digraph.lhs
@@ -2,7 +2,7 @@
 module Digraph(
 
 	-- At present the only one with a "nice" external interface
-	stronglyConnComp, stronglyConnCompR, SCC(..),
+	stronglyConnComp, stronglyConnCompR, SCC(..), flattenSCC, flattenSCCs,
 
 	Graph, Vertex, 
 	graphFromEdges, buildG, transposeG, reverseE, outdegree, indegree,
@@ -36,14 +36,20 @@ module Digraph(
 
 import Util	( sortLt )
 
--- GHC extensions
-import ST
-import MutableArray
+-- Extensions
+import MONAD_ST
 
 -- std interfaces
 import Maybe
 import Array
 import List
+import Outputable
+
+#if __GLASGOW_HASKELL__ >= 504
+import Data.Array.ST  hiding ( indices, bounds )
+#else
+import ST
+#endif
 \end{code}
 
 
@@ -57,6 +63,18 @@ import List
 data SCC vertex = AcyclicSCC vertex
 	        | CyclicSCC  [vertex]
 
+flattenSCCs :: [SCC a] -> [a]
+flattenSCCs = concatMap flattenSCC
+
+flattenSCC (AcyclicSCC v) = [v]
+flattenSCC (CyclicSCC vs) = vs
+
+instance Outputable a => Outputable (SCC a) where
+   ppr (AcyclicSCC v) = text "NONREC" $$ (nest 3 (ppr v))
+   ppr (CyclicSCC vs) = text "REC" $$ (nest 3 (vcat (map ppr vs)))
+\end{code}
+
+\begin{code}
 stronglyConnComp
 	:: Ord key
 	=> [(node, key, [key])]		-- The graph; its ok for the
@@ -77,7 +95,7 @@ stronglyConnCompR
 	=> [(node, key, [key])]		-- The graph; its ok for the
 					-- out-list to contain keys which arent
 					-- a vertex key, they are ignored
-	-> [SCC (node, key, [key])]
+	-> [SCC (node, key, [key])]	-- Topologically sorted
 
 stronglyConnCompR [] = []  -- added to avoid creating empty array in graphFromEdges -- SOF
 stronglyConnCompR edges
@@ -119,11 +137,7 @@ mapT    :: (Vertex -> a -> b) -> Table a -> Table b
 mapT f t = array (bounds t) [ (,) v (f v (t!v)) | v <- indices t ]
 
 buildG :: Bounds -> [Edge] -> Graph
-#ifdef REALLY_HASKELL_1_3
 buildG bounds edges = accumArray (flip (:)) [] bounds edges
-#else
-buildG bounds edges = accumArray (flip (:)) [] bounds [(,) k v | (k,v) <- edges]
-#endif
 
 transposeG  :: Graph -> Graph
 transposeG g = buildG (bounds g) (reverseE g)
@@ -154,7 +168,7 @@ graphFromEdges edges
     edges1	    = zipWith (,) [0..] sorted_edges
 
     graph	    = array bounds [(,) v (mapMaybe key_vertex ks) | (,) v (_,    _, ks) <- edges1]
-    key_map	    = array bounds [(,) v k			       | (,) v (_,    k, _ ) <- edges1]
+    key_map	    = array bounds [(,) v k			   | (,) v (_,    k, _ ) <- edges1]
     vertex_map	    = array bounds edges1
 
     (_,k1,_) `lt` (_,k2,_) = case k1 `compare` k2 of { LT -> True; other -> False }
@@ -203,7 +217,7 @@ drawTree         = unlines . draw
 draw (Node x ts) = grp this (space (length this)) (stLoop ts)
  where this          = s1 ++ x ++ " "
 
-       space n       = take n (repeat ' ')
+       space n       = replicate n ' '
 
        stLoop []     = [""]
        stLoop [t]    = grp s2 "  " (draw t)
@@ -225,16 +239,27 @@ draw (Node x ts) = grp this (space (length this)) (stLoop ts)
 %************************************************************************
 
 \begin{code}
-type Set s    = MutableArray s Vertex Bool
+#if __GLASGOW_HASKELL__ >= 504
+newSTArray :: Ix i => (i,i) -> e -> ST s (STArray s i e)
+newSTArray = newArray
+
+readSTArray :: Ix i => STArray s i e -> i -> ST s e
+readSTArray = readArray
+
+writeSTArray :: Ix i => STArray s i e -> i -> e -> ST s ()
+writeSTArray = writeArray
+#endif
+
+type Set s    = STArray s Vertex Bool
 
 mkEmpty      :: Bounds -> ST s (Set s)
-mkEmpty bnds  = newArray bnds False
+mkEmpty bnds  = newSTArray bnds False
 
 contains     :: Set s -> Vertex -> ST s Bool
-contains m v  = readArray m v
+contains m v  = readSTArray m v
 
 include      :: Set s -> Vertex -> ST s ()
-include m v   = writeArray m v True
+include m v   = writeSTArray m v True
 \end{code}
 
 \begin{code}
@@ -377,13 +402,13 @@ path g v w    = w `elem` (reachable g v)
 
 \begin{code}
 bcc :: Graph -> Forest [Vertex]
-bcc g = (concat . map bicomps . map (label g dnum)) forest
+bcc g = (concat . map bicomps . map (do_label g dnum)) forest
  where forest = dff g
        dnum   = preArr (bounds g) forest
 
-label :: Graph -> Table Int -> Tree Vertex -> Tree (Vertex,Int,Int)
-label g dnum (Node v ts) = Node (v,dnum!v,lv) us
- where us = map (label g dnum) ts
+do_label :: Graph -> Table Int -> Tree Vertex -> Tree (Vertex,Int,Int)
+do_label g dnum (Node v ts) = Node (v,dnum!v,lv) us
+ where us = map (do_label g dnum) ts
        lv = minimum ([dnum!v] ++ [dnum!w | w <- g!v]
                      ++ [lu | Node (u,du,lu) xs <- us])