Merge in new code generator branch.

[ghc-hetmet.git] / compiler / cmm / CmmZipUtil.hs

diff --git a/compiler/cmm/CmmZipUtil.hs b/compiler/cmm/CmmZipUtil.hs
deleted file mode 100644 (file)
index a91d76f..0000000
--- a/compiler/cmm/CmmZipUtil.hs
+++ /dev/null
@@ -1,39 +0,0 @@
-
-module CmmZipUtil
-  ( zipPreds
-  , givesUniquePredecessorTo
-  )
-where
-import BlockId
-import Prelude hiding (last, unzip)
-import ZipCfg
-
-import Maybes
-
--- | Compute the predecessors of each /reachable/ block
-zipPreds :: LastNode l => LGraph m l -> BlockEnv BlockSet
-zipPreds g = foldl add emptyBlockEnv (postorder_dfs g)
-    where add env block@(Block id _) =
-            foldl (\env sid ->
-                       let preds = lookupBlockEnv env sid `orElse` emptyBlockSet
-                       in  extendBlockEnv env sid (extendBlockSet preds id))
-            env (succs block)
-
--- | Tell if a graph gives a block a unique predecessor.  For
--- efficiency, this function is designed to be partially applied.
-
-givesUniquePredecessorTo :: LastNode l => LGraph m l -> BlockId -> Bool
-givesUniquePredecessorTo g = \id -> elemBlockSet id singlePreds
-    -- accumulates a pair of sets: the set of all blocks containing a single
-    -- predecessor, and the set of all blocks containing at least two predecessors
-    where (singlePreds, _) = fold_blocks add (emptyBlockSet, emptyBlockSet) g
-          add b (single, multi) = foldl add_pred (single, multi) (succs b)
-          add_pred pair@(single, multi) id =
-              if elemBlockSet id multi then pair
-              else if elemBlockSet id single then
-                       (removeBlockSet single id, extendBlockSet multi id)
-                   else
-                       (extendBlockSet single id, multi)
-              
-    
-