1 files changed, 36 insertions, 0 deletions
diff --git a/Stackify.hs b/Stackify.hs
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--- /dev/null
+++ b/Stackify.hs
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+module Stackify (
+    stackify
+) where
+
+import qualified Data.Map.Strict as Map
+import qualified Data.Set as Set
+
+import Intermediate
+
+
+data Funcinfo =
+    FuncInfo { fiGFD :: GlobFuncDef
+             , fiBBs :: [BB]
+             , fiTemps :: [Int] }
+
+stackify :: IRProgram -> IRProgram
+stackify (IRProgram origbbs gfds datas) =
+    let infos = [FuncInfo gfd bbs [i | RTemp i <- allRefs bbs]
+                | (gfd, bbs) <- partitionFunctions gfds origbbs]
+    -- LIVENESS ANALYSIS within the function!
+
+partitionFunctions :: Map.Map Name GlobFuncDef -> [BB] -> [(GlobFuncDef, [BB])]
+partitionFunctions gfds bbs =
+    let bbmap = Map.fromList [(bidOf bb, bb) | bb <- bbs]
+        pairs = [(gfd, floodFill bbmap bid) | gfd@(GlobFuncDef bid _ _) <- Map.elems gfds]
+        accums = scanl (<>) Set.empty (map snd pairs)
+        triples = zip3 accums pairs (tail accums)
+    in if all (\(from, (_, bbset), to) -> Set.size from + Set.size bbset == Set.size to) triples
+            && Set.size (last accums) == length bbs
+           then [(gfd, map (bbmap Map.!) (Set.toList bbset)) | (gfd, bbset) <- pairs]
+           else error "Non-partitionable BBs in partitionFunctions"
+  where
+    floodFill bbmap origin = go Set.empty origin
+      where
+        go seen at = let newseen = seen <> Set.fromList (outEdges (bbmap Map.! at))
+                     in foldl go newseen (Set.toList (newseen Set.\\ seen))