Remove special casing for BiSignalOut

clash-lib/prims/systemverilog/Clash_Signal_BiSignal.json

@@ -1,6 +1,7 @@
 [ { "BlackBox" :
     { "name" : "Clash.Signal.BiSignal.writeToBiSignal#",
       "kind" : "Declaration",
+      "renderVoid": "RenderVoid",
       "type" :
 "writeToBiSignal#
   :: HasCallStack                   -- ARG[0]

clash-lib/prims/verilog/Clash_Signal_BiSignal.json

@@ -1,6 +1,7 @@
 [ { "BlackBox" :
     { "name" : "Clash.Signal.BiSignal.writeToBiSignal#",
       "kind" : "Declaration",
+      "renderVoid": "RenderVoid",
       "type" :
 "writeToBiSignal#
   :: HasCallStack                   -- ARG[0]

clash-lib/prims/vhdl/Clash_Signal_BiSignal.json

@@ -1,6 +1,7 @@
 [ { "BlackBox" :
     { "name" : "Clash.Signal.BiSignal.writeToBiSignal#",
       "kind" : "Declaration",
+      "renderVoid": "RenderVoid",
       "type" :
 "writeToBiSignal#
   :: HasCallStack                   -- ARG[0]

clash-lib/src/Clash/Netlist.hs

@@ -331,39 +331,19 @@ mkNetDecl (id_,tm) = preserveVarEnv $ do
       go _ _ = return Nothing
 
 
-isWriteToBiSignalPrimitive :: Term -> Bool
-isWriteToBiSignalPrimitive e = case collectArgs e of
-  (Prim nm _,_) -> nm == StrictText.pack "Clash.Signal.BiSignal.writeToBiSignal#"
-  _             -> False
-
--- | Generate a list of Declarations for a let-binder, return an empty list
--- if the bound expression is a BiSignalOut
-mkDeclarations
-  :: HasCallStack
-  => Id
-  -- ^ LHS of the let-binder
-  -> Term
-  -- ^ RHS of the let-binder
-  -> NetlistMonad [Declaration]
-mkDeclarations bndr e = do
-  hty <- unsafeCoreTypeToHWTypeM' $(curLoc) (varType bndr)
-  if isBiSignalOut hty
-     then return []
-     else mkDeclarations' bndr e
-
 -- | Generate a list of Declarations for a let-binder
-mkDeclarations'
+mkDeclarations
   :: HasCallStack
   => Id
   -- ^ LHS of the let-binder
   -> Term
   -- ^ RHS of the let-binder
   -> NetlistMonad [Declaration]
-mkDeclarations' bndr (collectTicks -> (Var v,ticks)) =
+mkDeclarations bndr (collectTicks -> (Var v,ticks)) =
   withTicks ticks $ \tickDecls -> do
   mkFunApp (id2identifier bndr) v [] tickDecls
 
-mkDeclarations' _ e@(collectTicks -> (Case _ _ [],_)) = do
+mkDeclarations _ e@(collectTicks -> (Case _ _ [],_)) = do
   (_,sp) <- Lens.use curCompNm
   throw $ ClashException
           sp
@@ -374,11 +354,11 @@ mkDeclarations' _ e@(collectTicks -> (Case _ _ [],_)) = do
                     ])
           Nothing
 
-mkDeclarations' bndr (collectTicks -> (Case scrut altTy alts@(_:_:_),ticks)) =
+mkDeclarations bndr (collectTicks -> (Case scrut altTy alts@(_:_:_),ticks)) =
   withTicks ticks $ \tickDecls -> do
   mkSelection (Right bndr) scrut altTy alts tickDecls
 
-mkDeclarations' bndr app = do
+mkDeclarations bndr app = do
   let (appF,args0,ticks) = collectArgsTicks app
       (args,tyArgs) = partitionEithers args0
   case appF of
@@ -387,39 +367,28 @@ mkDeclarations' bndr app = do
       | otherwise   -> do
         (_,sp) <- Lens.use curCompNm
         throw (ClashException sp ($(curLoc) ++ "Not in normal form: Var-application with Type arguments:\n\n" ++ showPpr app) Nothing)
-    -- Do not generate any assignments writing to a BiSignalOut, as these
-    -- do not have any significance in a HDL. The single exception occurs
-    -- when writing to a BiSignal using the primitive 'writeToBiSignal'. In
-    -- the generate HDL it will write to an inout port, NOT the variable
-    -- having the actual type BiSignalOut.
-    -- _ | isBiSignalOut (id2type bndr) && (not $ isWriteToBiSignalPrimitive app) ->
-    --     return []
     _ -> do
-      hwTy <- unsafeCoreTypeToHWTypeM' $(curLoc) (id2type bndr)
-      if isBiSignalOut hwTy && not (isWriteToBiSignalPrimitive app)
-         then return []
-         else do
-          (exprApp,declsApp0) <- mkExpr False (Right bndr) (varType bndr) app
-          let dstId = id2identifier bndr
-              assn  =
-                case exprApp of
-                  Identifier _ Nothing ->
-                    -- Supplied 'bndr' was used to assign a result to, so we
-                    -- don't have to manually turn it into a declaration
-                    []
-                  Noop ->
-                    -- Rendered expression rendered a "noop" - a list of
-                    -- declarations without a result. Used for things like
-                    -- mealy IO / inline assertions.
-                    []
-                  _ ->
-                    -- Turn returned expression into declaration by assigning
-                    -- it to 'dstId'
-                    [Assignment dstId exprApp]
-          declsApp1 <- if null declsApp0
-                       then withTicks ticks return
-                       else pure declsApp0
-          return (declsApp1 ++ assn)
+      (exprApp,declsApp0) <- mkExpr False (Right bndr) (varType bndr) app
+      let dstId = id2identifier bndr
+          assn  =
+            case exprApp of
+              Identifier _ Nothing ->
+                -- Supplied 'bndr' was used to assign a result to, so we
+                -- don't have to manually turn it into a declaration
+                []
+              Noop ->
+                -- Rendered expression rendered a "noop" - a list of
+                -- declarations without a result. Used for things like
+                -- mealy IO / inline assertions.
+                []
+              _ ->
+                -- Turn returned expression into declaration by assigning
+                -- it to 'dstId'
+                [Assignment dstId exprApp]
+      declsApp1 <- if null declsApp0
+                   then withTicks ticks return
+                   else pure declsApp0
+      return (declsApp1 ++ assn)
 
 -- | Generate a declaration that selects an alternative based on the value of
 -- the scrutinee

clash-lib/src/Clash/Netlist/Util.hs

@@ -106,12 +106,6 @@ isVoidHwType _       = False
 isFilteredVoid :: FilteredHWType -> Bool
 isFilteredVoid = isVoidHwType . stripFiltered
 
-isBiSignalOut :: HWType -> Bool
-isBiSignalOut (Void (Just (BiDirectional Out _))) = True
-isBiSignalOut (Vector n ty) | n /= 0              = isBiSignalOut ty
-isBiSignalOut (RTree _ ty)                        = isBiSignalOut ty
-isBiSignalOut _                                   = False
-
 mkIdentifier :: IdType -> Identifier -> NetlistMonad Identifier
 mkIdentifier typ nm = Lens.use mkIdentifierFn <*> pure typ <*> pure nm