Add an empty let before starting normalization.

[matthijs/master-project/cλash.git] / NormalizeTools.hs

diff --git a/NormalizeTools.hs b/NormalizeTools.hs
index 58432d3eae50f40816c09d5385fc62a33d5de798..25c9273d8fb38ef4810f6207925aa8e109251e73 100644 (file)
--- a/NormalizeTools.hs
+++ b/NormalizeTools.hs
@@ -43,6 +43,30 @@ mkInternalVar str ty = do
   let name = Name.mkInternalName uniq occname SrcLoc.noSrcSpan
   return $ Var.mkLocalIdVar name ty IdInfo.vanillaIdInfo
 
+-- Create a new type variable with the given name and kind. A Unique is
+-- appended to the given name, to ensure uniqueness (not strictly neccesary,
+-- since the Unique is also stored in the name, but this ensures variable
+-- names are unique in the output).
+mkTypeVar :: String -> Type.Kind -> TransformMonad Var.Var
+mkTypeVar str kind = do
+  uniq <- mkUnique
+  let occname = OccName.mkVarOcc (str ++ show uniq)
+  let name = Name.mkInternalName uniq occname SrcLoc.noSrcSpan
+  return $ Var.mkTyVar name kind
+
+-- Creates a binder for the given expression with the given name. This
+-- works for both value and type level expressions, so it can return a Var or
+-- TyVar (which is just an alias for Var).
+mkBinderFor :: CoreExpr -> String -> TransformMonad Var.Var
+mkBinderFor (Type ty) string = mkTypeVar string (Type.typeKind ty)
+mkBinderFor expr string = mkInternalVar string (CoreUtils.exprType expr)
+
+-- Creates a reference to the given variable. This works for both a normal
+-- variable as well as a type variable
+mkReferenceTo :: Var.Var -> CoreExpr
+mkReferenceTo var | Var.isTyVar var = (Type $ Type.mkTyVarTy var)
+                  | otherwise       = (Var var)
+
 cloneVar :: Var.Var -> TransformMonad Var.Var
 cloneVar v = do
   uniq <- mkUnique
@@ -50,6 +74,17 @@ cloneVar v = do
   -- contains, but vannillaIdInfo is always correct, since it means "no info").
   return $ Var.lazySetVarIdInfo (Var.setVarUnique v uniq) IdInfo.vanillaIdInfo
 
+-- Creates a new function with the same name as the given binder (but with a
+-- new unique) and with the given function body. Returns the new binder for
+-- this function.
+mkFunction :: CoreBndr -> CoreExpr -> TransformMonad CoreBndr
+mkFunction bndr body = do
+  let ty = CoreUtils.exprType body
+  id <- cloneVar bndr
+  let newid = Var.setVarType id ty
+  Trans.lift $ addGlobalBind newid body
+  return newid
+
 -- Apply the given transformation to all expressions in the given expression,
 -- including the expression itself.
 everywhere :: (String, Transform) -> Transform
@@ -168,7 +203,7 @@ mkUnique = Trans.lift $ do
 -- given expression.
 substitute :: [(CoreBndr, CoreExpr)] -> CoreExpr -> CoreExpr
 substitute replace expr = CoreSubst.substExpr subs expr
-    where subs = foldl (\s (b, e) -> CoreSubst.extendIdSubst s b e) CoreSubst.emptySubst replace
+    where subs = foldl (\s (b, e) -> CoreSubst.extendSubst s b e) CoreSubst.emptySubst replace
 
 -- Run a given TransformSession. Used mostly to setup the right calls and
 -- an initial state.