+
+expandExpr binds l@(Let (NonRec b bexpr) expr) = do
+ (signal_decls, statements, arg_signals, res_signals) <- expandExpr binds bexpr
+ let binds' = (b, res_signals) : binds
+ (signal_decls', statements', arg_signals', res_signals') <- expandExpr binds' expr
+ return (
+ signal_decls ++ signal_decls',
+ statements ++ statements',
+ arg_signals',
+ res_signals')
+
+expandExpr binds app@(App _ _) = do
+ -- Is this a data constructor application?
+ case CoreUtils.exprIsConApp_maybe app of
+ -- Is this a tuple construction?
+ Just (dc, args) -> if DataCon.isTupleCon dc
+ then
+ expandBuildTupleExpr binds (dataConAppArgs dc args)
+ else
+ error "Data constructors other than tuples not supported"
+ otherise ->
+ -- Normal function application, should map to a component instantiation
+ let ((Var f), args) = collectArgs app in
+ expandApplicationExpr binds (CoreUtils.exprType app) f args
+
+expandExpr binds expr@(Case (Var v) b _ alts) =
+ case alts of
+ [alt] -> expandSingleAltCaseExpr binds v b alt
+ otherwise -> error $ "Multiple alternative case expression not supported: " ++ (showSDoc $ ppr expr)
+
+expandExpr binds expr@(Case _ b _ _) =
+ error $ "Case expression with non-variable scrutinee not supported: " ++ (showSDoc $ ppr expr)
+
+expandExpr binds expr =
+ error $ "Unsupported expression: " ++ (showSDoc $ ppr $ expr)
+
+-- Expands the construction of a tuple into VHDL
+expandBuildTupleExpr ::
+ [(CoreBndr, SignalNameMap)]
+ -- A list of bindings in effect
+ -> [CoreExpr] -- A list of expressions to put in the tuple
+ -> VHDLState ( [AST.SigDec], [AST.ConcSm], [SignalNameMap], SignalNameMap)
+ -- See expandExpr
+expandBuildTupleExpr binds args = do
+ -- Split the tuple constructor arguments into types and actual values.
+ -- Expand each of the values in the tuple
+ (signals_declss, statementss, arg_signalss, res_signals) <-
+ (Monad.liftM List.unzip4) $ mapM (expandExpr binds) args
+ if any (not . null) arg_signalss
+ then error "Putting high order functions in tuples not supported"
+ else
+ return (
+ concat signals_declss,
+ concat statementss,
+ [],
+ Tuple res_signals)
+
+-- Expands the most simple case expression that scrutinizes a plain variable
+-- and has a single alternative. This simple form currently allows only for
+-- unpacking tuple variables.
+expandSingleAltCaseExpr ::
+ [(CoreBndr, SignalNameMap)]
+ -- A list of bindings in effect
+ -> Var.Var -- The scrutinee
+ -> CoreBndr -- The binder to bind the scrutinee to
+ -> CoreAlt -- The single alternative
+ -> VHDLState ( [AST.SigDec], [AST.ConcSm], [SignalNameMap], SignalNameMap)
+ -- See expandExpr
+
+expandSingleAltCaseExpr binds v b alt@(DataAlt datacon, bind_vars, expr) =
+ if not (DataCon.isTupleCon datacon)
+ then
+ error $ "Dataconstructors other than tuple constructors not supported in case pattern of alternative: " ++ (showSDoc $ ppr alt)
+ else
+ let
+ -- Lookup the scrutinee (which must be a variable bound to a tuple) in
+ -- the existing bindings list and get the portname map for each of
+ -- it's elements.
+ Tuple tuple_ports = Maybe.fromMaybe
+ (error $ "Case expression uses unknown scrutinee " ++ getOccString v)
+ (lookup v binds)
+ -- TODO include b in the binds list
+ -- Merge our existing binds with the new binds.
+ binds' = (zip bind_vars tuple_ports) ++ binds
+ in
+ -- Expand the expression with the new binds list
+ expandExpr binds' expr
+
+expandSingleAltCaseExpr _ _ _ alt =
+ error $ "Case patterns other than data constructors not supported in case alternative: " ++ (showSDoc $ ppr alt)
+
+
+-- Expands the application of argument to a function into VHDL
+expandApplicationExpr ::
+ [(CoreBndr, SignalNameMap)]
+ -- A list of bindings in effect
+ -> Type -- The result type of the function call
+ -> Var.Var -- The function to call
+ -> [CoreExpr] -- A list of argumetns to apply to the function
+ -> VHDLState ( [AST.SigDec], [AST.ConcSm], [SignalNameMap], SignalNameMap)
+ -- See expandExpr
+expandApplicationExpr binds ty f args = do
+ let name = getOccString f
+ -- Generate a unique name for the application
+ appname <- uniqueName ("app_" ++ name)
+ -- Lookup the hwfunction to instantiate
+ HWFunction vhdl_id inports outport <- getHWFunc (appToHsFunction f args ty)
+ -- Expand each of the args, so each of them is reduced to output signals
+ (arg_signal_decls, arg_statements, arg_res_signals) <- expandArgs binds args
+ -- Bind each of the input ports to the expanded arguments
+ let inmaps = concat $ zipWith createAssocElems inports arg_res_signals
+ -- Create signal names for our result
+ -- TODO: We assume the result is a port here
+ let res_signal = getPortNameMapForTy (appname ++ "_out") ty (useAsPort ty)
+ -- Create the corresponding signal declarations
+ let signal_decls = mkSignalsFromMap res_signal
+ -- Bind each of the output ports to our output signals
+ let outmaps = mapOutputPorts outport res_signal
+ -- Instantiate the component
+ let component = AST.CSISm $ AST.CompInsSm
+ (AST.unsafeVHDLBasicId appname)
+ (AST.IUEntity (AST.NSimple vhdl_id))
+ (AST.PMapAspect (inmaps ++ outmaps))
+ -- Merge the generated declarations
+ return (
+ signal_decls ++ arg_signal_decls,
+ component : arg_statements,
+ [], -- We don't take any extra arguments; we don't support higher order functions yet
+ res_signal)