From: Matthijs Kooijman <m.kooijman@student.utwente.nl>
Date: Tue, 23 Jun 2009 12:54:54 +0000 (+0200)
Subject: Merge git://github.com/darchon/clash into cλash
X-Git-Url: https://git.stderr.nl/gitweb?a=commitdiff_plain;h=3ad8feb4ca1eecfb53bed973d7e0f1c3b4145d0f;hp=ff02403f76778ebab3e61a6d7a62827c6fb0a3de;p=matthijs%2Fmaster-project%2Fc%CE%BBash.git

Merge git://github.com/darchon/clash into cλash

* git://github.com/darchon/clash:
  Added builtin function 'empty'
---

diff --git a/Normalize.hs b/Normalize.hs
index 9aedb4b..747a95b 100644
--- a/Normalize.hs
+++ b/Normalize.hs
@@ -49,7 +49,7 @@ eta expr | is_fun expr && not (is_lam expr) = do
   change (Lam id (App expr (Var id)))
 -- Leave all other expressions unchanged
 eta e = return e
-etatop = notapplied ("eta", eta)
+etatop = notappargs ("eta", eta)
 
 --------------------------------
 -- β-reduction
@@ -69,6 +69,20 @@ beta expr = return expr
 -- Perform this transform everywhere
 betatop = everywhere ("beta", beta)
 
+--------------------------------
+-- Cast propagation
+--------------------------------
+-- Try to move casts as much downward as possible.
+castprop, castproptop :: Transform
+castprop (Cast (Let binds expr) ty) = change $ Let binds (Cast expr ty)
+castprop expr@(Cast (Case scrut b _ alts) ty) = change (Case scrut b ty alts')
+  where
+    alts' = map (\(con, bndrs, expr) -> (con, bndrs, (Cast expr ty))) alts
+-- Leave all other expressions unchanged
+castprop expr = return expr
+-- Perform this transform everywhere
+castproptop = everywhere ("castprop", castprop)
+
 --------------------------------
 -- let recursification
 --------------------------------
@@ -407,7 +421,7 @@ funproptop = everywhere ("funprop", funprop)
 
 
 -- What transforms to run?
-transforms = [typeproptop, funproptop, etatop, betatop, letremovetop, letrectop, letsimpltop, letflattop, casewildtop, scrutsimpltop, casevalsimpltop, caseremovetop, inlinefuntop, appsimpltop]
+transforms = [typeproptop, funproptop, etatop, betatop, castproptop, letremovetop, letrectop, letsimpltop, letflattop, casewildtop, scrutsimpltop, casevalsimpltop, caseremovetop, inlinefuntop, appsimpltop]
 
 -- Turns the given bind into VHDL
 normalizeModule :: 
diff --git a/NormalizeTools.hs b/NormalizeTools.hs
index 14e3fac..8e57ba8 100644
--- a/NormalizeTools.hs
+++ b/NormalizeTools.hs
@@ -142,26 +142,33 @@ subeverywhere trans (Case scrut b t alts) = do
     transalt (con, binders, expr) = do
       expr' <- trans expr
       return (con, binders, expr')
-      
 
-subeverywhere trans expr = return expr
+subeverywhere trans (Var x) = return $ Var x
+subeverywhere trans (Lit x) = return $ Lit x
+subeverywhere trans (Type x) = return $ Type x
 
--- Apply the given transformation to all expressions, except for every first
--- argument of an application.
-notapplied :: (String, Transform) -> Transform
-notapplied trans = applyboth (subnotapplied trans) trans
+subeverywhere trans (Cast expr ty) = do
+  expr' <- trans expr
+  return $ Cast expr' ty
+
+subeverywhere trans expr = error $ "NormalizeTools.subeverywhere Unsupported expression: " ++ show expr
+
+-- Apply the given transformation to all expressions, except for direct
+-- arguments of an application
+notappargs :: (String, Transform) -> Transform
+notappargs trans = applyboth (subnotappargs trans) trans
 
 -- Apply the given transformation to all (direct and indirect) subexpressions
--- (but not the expression itself), except for the first argument of an
--- applicfirst argument of an application
-subnotapplied :: (String, Transform) -> Transform
-subnotapplied trans (App a b) = do
-  a' <- subnotapplied trans a
-  b' <- notapplied trans b
+-- (but not the expression itself), except for direct arguments of an
+-- application
+subnotappargs :: (String, Transform) -> Transform
+subnotappargs trans (App a b) = do
+  a' <- subnotappargs trans a
+  b' <- subnotappargs trans b
   return $ App a' b'
 
 -- Let subeverywhere handle all other expressions
-subnotapplied trans expr = subeverywhere (notapplied trans) expr
+subnotappargs trans expr = subeverywhere (notappargs trans) expr
 
 -- Runs each of the transforms repeatedly inside the State monad.
 dotransforms :: [Transform] -> CoreExpr -> TransformSession CoreExpr
diff --git a/VHDL.hs b/VHDL.hs
index eb45420..b2d5b30 100644
--- a/VHDL.hs
+++ b/VHDL.hs
@@ -264,6 +264,11 @@ mkConcSm ::
   (CoreSyn.CoreBndr, CoreSyn.CoreExpr) -- ^ The binding to process
   -> VHDLState [AST.ConcSm] -- ^ The corresponding VHDL component instantiations.
 
+
+-- Ignore Cast expressions, they should not longer have any meaning as long as
+-- the type works out.
+mkConcSm (bndr, Cast expr ty) = mkConcSm (bndr, expr)
+
 mkConcSm (bndr, app@(CoreSyn.App _ _))= do
   let (CoreSyn.Var f, args) = CoreSyn.collectArgs app
   let valargs' = filter isValArg args