[hoopl] refactor the passes, add helper mapE and insnToGraph functions

hoopl/ConstProp.hs

@@ -57,15 +57,13 @@ constPropPass = FwdPass
 initFact :: ConstFact
 initFact = Map.fromList []
 
--- Rewriting: replace constant variables
-  
+singleInsn = return . Just . insnToGraph
+
 constProp :: FuelMonad m => FwdRewrite m Insn ConstFact
 constProp = mkFRewrite cp
  where
-    cp :: (Monad m) => Insn e x -> Map.Map Int (WithTop Expr) -> m (Maybe (Graph Insn e x))
-    cp (BifPlus reg a b) f = return $ Just $ mkMiddle (BifPlus reg (lookup f a) (lookup f b))
-    cp (Subcall reg args) f = return $ Just $ mkMiddle (Subcall reg (map (lookup f) args))
-    cp _ _ = return Nothing
+    cp :: (Monad m) => Insn e x -> ConstFact -> m (Maybe (Graph Insn e x))
+    cp insn f = singleInsn $ mapE (lookup f) insn
     lookup f reg@(Reg r)  = case Map.lookup r f of
         Just (PElem c) -> c 
         _ -> reg
@@ -79,7 +77,7 @@ simplify :: FuelMonad m => FwdRewrite m Insn ConstFact
 simplify = mkFRewrite s
  where
     s :: (Monad m) => Insn e x -> a -> m (Maybe (Graph Insn e x))
-    s (BifPlus reg (Double a) (Double b)) _ = return $ Just $ mkMiddle $ RegSet reg (Double (a+b))
+    s (BifPlus reg (Double a) (Double b)) _ = singleInsn $ RegSet reg (Double (a+b))
     s _ _ = return Nothing
 
 

hoopl/Insn.hs

@@ -1,5 +1,5 @@
 {-# LANGUAGE ViewPatterns,GADTs,StandaloneDeriving,NoMonomorphismRestriction #-}
-module Insn (Insn(..),Expr(..)) where
+module Insn (Insn(..),Expr(..),mapE,insnToGraph) where
 import Compiler.Hoopl
 -- a side effect free expression
 -- FIXME handle Box and Ann smartly
@@ -11,3 +11,15 @@ data Insn e x where
     Subcall :: Int -> [Expr] -> Insn O O
     BifPlus :: Int -> Expr -> Expr -> Insn O O
     RegSet  :: Int -> Expr -> Insn O O
+
+mapE :: (Expr -> Expr) -> Insn e x -> Insn e x
+mapE func (BifPlus reg a b) = BifPlus reg (func a) (func b)
+mapE func (Subcall reg args)   = Subcall reg (map func args)
+mapE func (RegSet reg a) = RegSet reg (func a) 
+mapE func (Fetch reg a) = Fetch reg (func a)
+
+insnToGraph :: Insn e x -> Graph Insn e x
+insnToGraph n@(Fetch _ _)   = mkMiddle n
+insnToGraph n@(Subcall _ _)    = mkMiddle n
+insnToGraph n@(BifPlus _ _ _)    = mkMiddle n
+insnToGraph n@(RegSet _ _)    = mkMiddle n