Merge branch 'cλash' of http://git.stderr.nl/matthijs/projects/master-project

[matthijs/master-project/cλash.git] / cλash / CLasH / Normalize.hs

diff --git a/cλash/CLasH/Normalize.hs b/cλash/CLasH/Normalize.hs
index f3a9d2e4662ca2e204d761fa1c80fc4272628a73..1d40f92d52f7b94989fc9215bcfd15723a9001e0 100644 (file)
--- a/cλash/CLasH/Normalize.hs
+++ b/cλash/CLasH/Normalize.hs
@@ -4,7 +4,7 @@
 -- top level function "normalize", and defines the actual transformation passes that
 -- are performed.
 --
-module CLasH.Normalize (getNormalized, normalizeExpr) where
+module CLasH.Normalize (getNormalized, normalizeExpr, splitNormalized) where
 
 -- Standard modules
 import Debug.Trace
@@ -574,9 +574,9 @@ normalizeExpr what expr = do
       -- the last let).
       let expr' = Let (Rec []) expr
       -- Normalize this expression
-      trace ("Transforming " ++ what ++ "\nBefore:\n\n" ++ showSDoc ( ppr expr' ) ++ "\n") $ return ()
+      trace (what ++ " before normalization:\n\n" ++ showSDoc ( ppr expr' ) ++ "\n") $ return ()
       expr'' <- dotransforms transforms expr'
-      trace ("\nAfter:\n\n" ++ showSDoc ( ppr expr'')) $ return ()
+      trace ("\n" ++ what ++ " after normalization:\n\n" ++ showSDoc ( ppr expr'')) $ return ()
       return expr''
 
 -- | Get the value that is bound to the given binder at top level. Fails when
@@ -589,3 +589,31 @@ getBinding bndr = Utils.makeCached bndr tsBindings $ do
   -- If the binding isn't in the "cache" (bindings map), then we can't create
   -- it out of thin air, so return an error.
   error $ "Normalize.getBinding: Unknown function requested: " ++ show bndr
+
+-- | Split a normalized expression into the argument binders, top level
+--   bindings and the result binder.
+splitNormalized ::
+  CoreExpr -- ^ The normalized expression
+  -> ([CoreBndr], [Binding], CoreBndr)
+splitNormalized expr = (args, binds, res)
+  where
+    (args, letexpr) = CoreSyn.collectBinders expr
+    (binds, resexpr) = flattenLets letexpr
+    res = case resexpr of 
+      (Var x) -> x
+      _ -> error $ "Normalize.splitNormalized: Not in normal form: " ++ pprString expr ++ "\n"
+
+-- | Flattens nested lets into a single list of bindings. The expression
+--   passed does not have to be a let expression, if it isn't an empty list of
+--   bindings is returned.
+flattenLets ::
+  CoreExpr -- ^ The expression to flatten.
+  -> ([Binding], CoreExpr) -- ^ The bindings and resulting expression.
+flattenLets (Let binds expr) = 
+  (bindings ++ bindings', expr')
+  where
+    -- Recursively flatten the contained expression
+    (bindings', expr') =flattenLets expr
+    -- Flatten our own bindings to remove the Rec / NonRec constructors
+    bindings = CoreSyn.flattenBinds [binds]
+flattenLets expr = ([], expr)