+ -> FlattenState ([SignalMap], SignalMap)
+
+flattenExpr binds lam@(Lam b expr) = do
+ -- Find the type of the binder
+ let (arg_ty, _) = Type.splitFunTy (CoreUtils.exprType lam)
+ -- Create signal names for the binder
+ defs <- genSignals arg_ty
+ -- Add name hints to the generated signals
+ let binder_name = Name.getOccString b
+ Traversable.mapM (addNameHint binder_name) defs
+ let binds' = (b, Left defs):binds
+ (args, res) <- flattenExpr binds' expr
+ return (defs : args, res)
+
+flattenExpr binds var@(Var id) =
+ case Var.globalIdVarDetails id of
+ IdInfo.NotGlobalId ->
+ let
+ bind = Maybe.fromMaybe
+ (error $ "Local value " ++ Name.getOccString id ++ " is unknown")
+ (lookup id binds)
+ in
+ case bind of
+ Left sig_use -> return ([], sig_use)
+ Right _ -> error "Higher order functions not supported."
+ IdInfo.DataConWorkId datacon -> do
+ if DataCon.isTupleCon datacon && (null $ DataCon.dataConAllTyVars datacon)
+ then do
+ -- Empty tuple construction
+ return ([], Tuple [])
+ else do
+ lit <- dataConToLiteral datacon
+ let ty = CoreUtils.exprType var
+ sig_id <- genSignalId SigInternal ty
+ -- Add a name hint to the signal
+ addNameHint (Name.getOccString id) sig_id
+ addDef (UncondDef (Right $ Literal lit) sig_id)
+ return ([], Single sig_id)
+ otherwise ->
+ error $ "Ids other than local vars and dataconstructors not supported: " ++ (showSDoc $ ppr id)
+
+flattenExpr 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
+ flattenBuildTupleExpr binds (dataConAppArgs dc args)
+ else
+ error $ "Data constructors other than tuples not supported: " ++ (showSDoc $ ppr app)
+ otherwise ->
+ -- Normal function application
+ let ((Var f), args) = collectArgs app in
+ let fname = Name.getOccString f in
+ if fname == "fst" || fname == "snd" then do
+ (args', Tuple [a, b]) <- flattenExpr binds (last args)
+ return (args', if fname == "fst" then a else b)
+ else if fname == "patError" then do
+ -- This is essentially don't care, since the program will error out
+ -- here. We'll just define undriven signals here.
+ let (argtys, resty) = Type.splitFunTys $ CoreUtils.exprType app
+ args <- mapM genSignals argtys
+ res <- genSignals resty
+ mapM (Traversable.mapM (addNameHint "NC")) args
+ Traversable.mapM (addNameHint "NC") res
+ return (args, res)
+ else if fname == "==" then do
+ -- Flatten the last two arguments (this skips the type arguments)
+ ([], a) <- flattenExpr binds (last $ init args)
+ ([], b) <- flattenExpr binds (last args)
+ res <- mkEqComparisons a b
+ return ([], res)
+ else
+ flattenApplicationExpr binds (CoreUtils.exprType app) f args
+ where
+ mkEqComparisons :: SignalMap -> SignalMap -> FlattenState SignalMap
+ mkEqComparisons a b = do
+ let zipped = zipValueMaps a b
+ Traversable.mapM mkEqComparison zipped
+
+ mkEqComparison :: (SignalId, SignalId) -> FlattenState SignalId
+ mkEqComparison (a, b) = do
+ -- Generate a signal to hold our result
+ res <- genSignalId SigInternal TysWiredIn.boolTy
+ -- Add a name hint to the signal
+ addNameHint ("s" ++ show a ++ "_eq_s" ++ show b) res
+ addDef (UncondDef (Right $ Eq a b) res)
+ return res
+
+ flattenBuildTupleExpr binds args = do
+ -- Flatten each of our args
+ flat_args <- (State.mapM (flattenExpr binds) args)
+ -- Check and split each of the arguments
+ let (_, arg_ress) = unzip (zipWith checkArg args flat_args)
+ let res = Tuple arg_ress
+ return ([], res)
+
+ -- | Flatten a normal application expression
+ flattenApplicationExpr binds ty f args = do
+ -- Find the function to call
+ let func = appToHsFunction ty f args
+ -- Flatten each of our args
+ flat_args <- (State.mapM (flattenExpr binds) args)
+ -- Check and split each of the arguments
+ let (_, arg_ress) = unzip (zipWith checkArg args flat_args)
+ -- Generate signals for our result
+ res <- genSignals ty
+ -- Add name hints to the generated signals
+ let resname = Name.getOccString f ++ "_res"
+ Traversable.mapM (addNameHint resname) res
+ -- Create the function application
+ let app = FApp {
+ appFunc = func,
+ appArgs = arg_ress,
+ appRes = res
+ }
+ addDef app
+ return ([], res)
+ -- | Check a flattened expression to see if it is valid to use as a
+ -- function argument. The first argument is the original expression for
+ -- use in the error message.
+ checkArg arg flat =
+ let (args, res) = flat in
+ if not (null args)
+ then error $ "Passing lambda expression or function as a function argument not supported: " ++ (showSDoc $ ppr arg)
+ else flat
+
+flattenExpr binds l@(Let (NonRec b bexpr) expr) = do
+ (b_args, b_res) <- flattenExpr binds bexpr
+ if not (null b_args)
+ then
+ error $ "Higher order functions not supported in let expression: " ++ (showSDoc $ ppr l)
+ else do
+ let binds' = (b, Left b_res) : binds
+ -- Add name hints to the generated signals
+ let binder_name = Name.getOccString b
+ Traversable.mapM (addNameHint binder_name) b_res
+ flattenExpr binds' expr
+
+flattenExpr binds l@(Let (Rec _) _) = error $ "Recursive let definitions not supported: " ++ (showSDoc $ ppr l)
+
+flattenExpr binds expr@(Case scrut b _ alts) = do
+ -- TODO: Special casing for higher order functions
+ -- Flatten the scrutinee
+ (_, res) <- flattenExpr binds scrut
+ case alts of
+ -- TODO include b in the binds list
+ [alt] -> flattenSingleAltCaseExpr binds res b alt
+ -- Reverse the alternatives, so the __DEFAULT alternative ends up last
+ otherwise -> flattenMultipleAltCaseExpr binds res b (reverse alts)
+ where
+ flattenSingleAltCaseExpr ::
+ BindMap
+ -- A list of bindings in effect
+ -> SignalMap -- The scrutinee
+ -> CoreBndr -- The binder to bind the scrutinee to
+ -> CoreAlt -- The single alternative
+ -> FlattenState ( [SignalMap], SignalMap) -- See expandExpr
+
+ flattenSingleAltCaseExpr binds scrut b alt@(DataAlt datacon, bind_vars, expr) =
+ if DataCon.isTupleCon datacon
+ then do
+ -- Unpack 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.
+ let Tuple tuple_sigs = scrut
+ -- Add name hints to the returned signals
+ let binder_name = Name.getOccString b
+ Monad.zipWithM (\name sigs -> Traversable.mapM (addNameHint $ Name.getOccString name) sigs) bind_vars tuple_sigs
+ -- Merge our existing binds with the new binds.
+ let binds' = (zip bind_vars (map Left tuple_sigs)) ++ binds
+ -- Expand the expression with the new binds list
+ flattenExpr binds' expr
+ else
+ if null bind_vars
+ then
+ -- DataAlts without arguments don't need processing
+ -- (flattenMultipleAltCaseExpr will have done this already).
+ flattenExpr binds expr
+ else
+ error $ "Dataconstructors other than tuple constructors cannot have binder arguments in case pattern of alternative: " ++ (showSDoc $ ppr alt)