module VectUtils (
collectAnnTypeBinders, collectAnnTypeArgs, isAnnTypeArg,
+ collectAnnValBinders,
+ mkDataConTag,
splitClosureTy,
- mkPADictType, mkPArrayType,
- paDictArgType, paDictOfType,
- paMethod, lengthPA, replicatePA, emptyPA,
- polyAbstract, polyApply,
- lookupPArrayFamInst,
- hoistExpr, takeHoisted
+ mkPRepr, mkToPRepr, mkFromPRepr,
+ mkPADictType, mkPArrayType, mkPReprType,
+ parrayReprTyCon, parrayReprDataCon, mkVScrut,
+ prDictOfType, prCoerce,
+ paDictArgType, paDictOfType, paDFunType,
+ paMethod, lengthPA, replicatePA, emptyPA, liftPA,
+ polyAbstract, polyApply, polyVApply,
+ hoistBinding, hoistExpr, hoistPolyVExpr, takeHoisted,
+ buildClosure, buildClosures,
+ mkClosureApp
) where
#include "HsVersions.h"
+import VectCore
import VectMonad
import DsUtils
import CoreSyn
import CoreUtils
+import Coercion
import Type
import TypeRep
import TyCon
-import DataCon ( dataConWrapId )
+import DataCon ( DataCon, dataConWrapId, dataConTag )
import Var
import Id ( mkWildId )
import MkId ( unwrapFamInstScrut )
+import Name ( Name )
import PrelNames
import TysWiredIn
import BasicTypes ( Boxity(..) )
import Outputable
import FastString
-import Control.Monad ( liftM, zipWithM_ )
+import Control.Monad ( liftM, liftM2, zipWithM_ )
collectAnnTypeArgs :: AnnExpr b ann -> (AnnExpr b ann, [Type])
collectAnnTypeArgs expr = go expr []
go bs (_, AnnLam b e) | isTyVar b = go (b:bs) e
go bs e = (reverse bs, e)
+collectAnnValBinders :: AnnExpr Var ann -> ([Var], AnnExpr Var ann)
+collectAnnValBinders expr = go [] expr
+ where
+ go bs (_, AnnLam b e) | isId b = go (b:bs) e
+ go bs e = (reverse bs, e)
+
isAnnTypeArg :: AnnExpr b ann -> Bool
isAnnTypeArg (_, AnnType t) = True
isAnnTypeArg _ = False
-isClosureTyCon :: TyCon -> Bool
-isClosureTyCon tc = tyConName tc == closureTyConName
+mkDataConTag :: DataCon -> CoreExpr
+mkDataConTag dc = mkConApp intDataCon [mkIntLitInt $ dataConTag dc]
-splitClosureTy :: Type -> (Type, Type)
-splitClosureTy ty
- | Just (tc, [arg_ty, res_ty]) <- splitTyConApp_maybe ty
- , isClosureTyCon tc
- = (arg_ty, res_ty)
+splitUnTy :: String -> Name -> Type -> Type
+splitUnTy s name ty
+ | Just (tc, [ty']) <- splitTyConApp_maybe ty
+ , tyConName tc == name
+ = ty'
+
+ | otherwise = pprPanic s (ppr ty)
+
+splitBinTy :: String -> Name -> Type -> (Type, Type)
+splitBinTy s name ty
+ | Just (tc, [ty1, ty2]) <- splitTyConApp_maybe ty
+ , tyConName tc == name
+ = (ty1, ty2)
- | otherwise = pprPanic "splitClosureTy" (ppr ty)
+ | otherwise = pprPanic s (ppr ty)
-isPArrayTyCon :: TyCon -> Bool
-isPArrayTyCon tc = tyConName tc == parrayTyConName
+splitCrossTy :: Type -> (Type, Type)
+splitCrossTy = splitBinTy "splitCrossTy" ndpCrossTyConName
+
+splitPlusTy :: Type -> (Type, Type)
+splitPlusTy = splitBinTy "splitSumTy" ndpPlusTyConName
+
+splitEmbedTy :: Type -> Type
+splitEmbedTy = splitUnTy "splitEmbedTy" embedTyConName
+
+splitClosureTy :: Type -> (Type, Type)
+splitClosureTy = splitBinTy "splitClosureTy" closureTyConName
splitPArrayTy :: Type -> Type
-splitPArrayTy ty
- | Just (tc, [arg_ty]) <- splitTyConApp_maybe ty
- , isPArrayTyCon tc
- = arg_ty
+splitPArrayTy = splitUnTy "splitPArrayTy" parrayTyConName
- | otherwise = pprPanic "splitPArrayTy" (ppr ty)
+mkBuiltinTyConApp :: (Builtins -> TyCon) -> [Type] -> VM Type
+mkBuiltinTyConApp get_tc tys
+ = do
+ tc <- builtin get_tc
+ return $ mkTyConApp tc tys
-mkPADictType :: Type -> VM Type
-mkPADictType ty
+mkBuiltinTyConApps :: (Builtins -> TyCon) -> [Type] -> Type -> VM Type
+mkBuiltinTyConApps get_tc tys ty
+ = do
+ tc <- builtin get_tc
+ return $ foldr (mk tc) ty tys
+ where
+ mk tc ty1 ty2 = mkTyConApp tc [ty1,ty2]
+
+mkBuiltinTyConApps1 :: (Builtins -> TyCon) -> Type -> [Type] -> VM Type
+mkBuiltinTyConApps1 get_tc dft [] = return dft
+mkBuiltinTyConApps1 get_tc dft tys
+ = do
+ tc <- builtin get_tc
+ case tys of
+ [] -> pprPanic "mkBuiltinTyConApps1" (ppr tc)
+ _ -> return $ foldr1 (mk tc) tys
+ where
+ mk tc ty1 ty2 = mkTyConApp tc [ty1,ty2]
+
+mkPRepr :: [[Type]] -> VM Type
+mkPRepr [] = return unitTy
+mkPRepr tys
+ = do
+ embed <- builtin embedTyCon
+ cross <- builtin crossTyCon
+ plus <- builtin plusTyCon
+
+ let mk_embed ty = mkTyConApp embed [ty]
+ mk_cross ty1 ty2 = mkTyConApp cross [ty1, ty2]
+ mk_plus ty1 ty2 = mkTyConApp plus [ty1, ty2]
+
+ mk_tup [] = unitTy
+ mk_tup tys = foldr1 mk_cross tys
+
+ mk_sum [] = unitTy
+ mk_sum tys = foldr1 mk_plus tys
+
+ return . mk_sum
+ . map (mk_tup . map mk_embed)
+ $ tys
+
+mkToPRepr :: [[CoreExpr]] -> VM ([CoreExpr], Type)
+mkToPRepr ess
= do
- tc <- builtin paDictTyCon
- return $ TyConApp tc [ty]
+ embed_tc <- builtin embedTyCon
+ embed_dc <- builtin embedDataCon
+ cross_tc <- builtin crossTyCon
+ cross_dc <- builtin crossDataCon
+ plus_tc <- builtin plusTyCon
+ left_dc <- builtin leftDataCon
+ right_dc <- builtin rightDataCon
+
+ let mk_embed expr
+ = (mkConApp embed_dc [Type ty, expr],
+ mkTyConApp embed_tc [ty])
+ where ty = exprType expr
+
+ mk_cross (expr1, ty1) (expr2, ty2)
+ = (mkConApp cross_dc [Type ty1, Type ty2, expr1, expr2],
+ mkTyConApp cross_tc [ty1, ty2])
+
+ mk_tup [] = (Var unitDataConId, unitTy)
+ mk_tup es = foldr1 mk_cross es
+
+ mk_sum [] = ([Var unitDataConId], unitTy)
+ mk_sum [(expr, ty)] = ([expr], ty)
+ mk_sum ((expr, lty) : es)
+ = let (alts, rty) = mk_sum es
+ in
+ (mkConApp left_dc [Type lty, Type rty, expr]
+ : [mkConApp right_dc [Type lty, Type rty, alt] | alt <- alts],
+ mkTyConApp plus_tc [lty, rty])
+
+ return . mk_sum $ map (mk_tup . map mk_embed) ess
+
+mkFromPRepr :: CoreExpr -> Type -> [([Var], CoreExpr)] -> VM CoreExpr
+mkFromPRepr scrut res_ty alts
+ = do
+ embed_dc <- builtin embedDataCon
+ cross_dc <- builtin crossDataCon
+ left_dc <- builtin leftDataCon
+ right_dc <- builtin rightDataCon
+ pa_tc <- builtin paTyCon
+
+ let un_embed expr ty var res
+ = Case expr (mkWildId ty) res_ty
+ [(DataAlt embed_dc, [var], res)]
+
+ un_cross expr ty var1 var2 res
+ = Case expr (mkWildId ty) res_ty
+ [(DataAlt cross_dc, [var1, var2], res)]
+
+ un_tup expr ty [] res = return res
+ un_tup expr ty [var] res = return $ un_embed expr ty var res
+ un_tup expr ty (var : vars) res
+ = do
+ lv <- newLocalVar FSLIT("x") lty
+ rv <- newLocalVar FSLIT("y") rty
+ liftM (un_cross expr ty lv rv
+ . un_embed (Var lv) lty var)
+ (un_tup (Var rv) rty vars res)
+ where
+ (lty, rty) = splitCrossTy ty
+
+ un_plus expr ty var1 var2 res1 res2
+ = Case expr (mkWildId ty) res_ty
+ [(DataAlt left_dc, [var1], res1),
+ (DataAlt right_dc, [var2], res2)]
+
+ un_sum expr ty [(vars, res)] = un_tup expr ty vars res
+ un_sum expr ty ((vars, res) : alts)
+ = do
+ lv <- newLocalVar FSLIT("l") lty
+ rv <- newLocalVar FSLIT("r") rty
+ liftM2 (un_plus expr ty lv rv)
+ (un_tup (Var lv) lty vars res)
+ (un_sum (Var rv) rty alts)
+ where
+ (lty, rty) = splitPlusTy ty
+
+ un_sum scrut (exprType scrut) alts
+
+mkClosureType :: Type -> Type -> VM Type
+mkClosureType arg_ty res_ty = mkBuiltinTyConApp closureTyCon [arg_ty, res_ty]
+
+mkClosureTypes :: [Type] -> Type -> VM Type
+mkClosureTypes = mkBuiltinTyConApps closureTyCon
+
+mkPReprType :: Type -> VM Type
+mkPReprType ty = mkBuiltinTyConApp preprTyCon [ty]
+
+mkPADictType :: Type -> VM Type
+mkPADictType ty = mkBuiltinTyConApp paTyCon [ty]
mkPArrayType :: Type -> VM Type
-mkPArrayType ty
+mkPArrayType ty = mkBuiltinTyConApp parrayTyCon [ty]
+
+parrayReprTyCon :: Type -> VM (TyCon, [Type])
+parrayReprTyCon ty = builtin parrayTyCon >>= (`lookupFamInst` [ty])
+
+parrayReprDataCon :: Type -> VM (DataCon, [Type])
+parrayReprDataCon ty
+ = do
+ (tc, arg_tys) <- parrayReprTyCon ty
+ let [dc] = tyConDataCons tc
+ return (dc, arg_tys)
+
+mkVScrut :: VExpr -> VM (VExpr, TyCon, [Type])
+mkVScrut (ve, le)
+ = do
+ (tc, arg_tys) <- parrayReprTyCon (exprType ve)
+ return ((ve, unwrapFamInstScrut tc arg_tys le), tc, arg_tys)
+
+prDictOfType :: Type -> VM CoreExpr
+prDictOfType orig_ty
+ | Just (tycon, ty_args) <- splitTyConApp_maybe orig_ty
+ = do
+ dfun <- traceMaybeV "prDictOfType" (ppr tycon) (lookupTyConPR tycon)
+ prDFunApply (Var dfun) ty_args
+
+prDFunApply :: CoreExpr -> [Type] -> VM CoreExpr
+prDFunApply dfun tys
+ = do
+ args <- mapM mkDFunArg arg_tys
+ return $ mkApps mono_dfun args
+ where
+ mono_dfun = mkTyApps dfun tys
+ (arg_tys, _) = splitFunTys (exprType mono_dfun)
+
+mkDFunArg :: Type -> VM CoreExpr
+mkDFunArg ty
+ | Just (tycon, [arg]) <- splitTyConApp_maybe ty
+
+ = let name = tyConName tycon
+
+ get_dict | name == paTyConName = paDictOfType
+ | name == prTyConName = prDictOfType
+ | otherwise = pprPanic "mkDFunArg" (ppr ty)
+
+ in get_dict arg
+
+mkDFunArg ty = pprPanic "mkDFunArg" (ppr ty)
+
+prCoerce :: TyCon -> [Type] -> CoreExpr -> VM CoreExpr
+prCoerce repr_tc args expr
+ | Just arg_co <- tyConFamilyCoercion_maybe repr_tc
= do
- tc <- builtin parrayTyCon
- return $ TyConApp tc [ty]
+ pr_tc <- builtin prTyCon
+
+ let co = mkAppCoercion (mkTyConApp pr_tc [])
+ (mkSymCoercion (mkTyConApp arg_co args))
+
+ return $ mkCoerce co expr
paDictArgType :: TyVar -> VM (Maybe Type)
paDictArgType tv = go (TyVarTy tv) (tyVarKind tv)
paDFunApply dfun ty_args
paDictOfTyApp (TyConApp tc _) ty_args
= do
- pa_class <- builtin paClass
- (dfun, ty_args') <- lookupInst pa_class [TyConApp tc ty_args]
- paDFunApply (Var dfun) ty_args'
+ dfun <- traceMaybeV "paDictOfTyApp" (ppr tc) (lookupTyConPA tc)
+ paDFunApply (Var dfun) ty_args
paDictOfTyApp ty ty_args = pprPanic "paDictOfTyApp" (ppr ty)
+paDFunType :: TyCon -> VM Type
+paDFunType tc
+ = do
+ margs <- mapM paDictArgType tvs
+ res <- mkPADictType (mkTyConApp tc arg_tys)
+ return . mkForAllTys tvs
+ $ mkFunTys [arg | Just arg <- margs] res
+ where
+ tvs = tyConTyVars tc
+ arg_tys = mkTyVarTys tvs
+
paDFunApply :: CoreExpr -> [Type] -> VM CoreExpr
paDFunApply dfun tys
= do
emptyPA :: Type -> VM CoreExpr
emptyPA = paMethod emptyPAVar
+liftPA :: CoreExpr -> VM CoreExpr
+liftPA x
+ = do
+ lc <- builtin liftingContext
+ replicatePA (Var lc) x
+
+newLocalVVar :: FastString -> Type -> VM VVar
+newLocalVVar fs vty
+ = do
+ lty <- mkPArrayType vty
+ vv <- newLocalVar fs vty
+ lv <- newLocalVar fs lty
+ return (vv,lv)
+
polyAbstract :: [TyVar] -> ((CoreExpr -> CoreExpr) -> VM a) -> VM a
polyAbstract tvs p
= localV
dicts <- mapM paDictOfType tys
return $ expr `mkTyApps` tys `mkApps` dicts
-lookupPArrayFamInst :: Type -> VM (TyCon, [Type])
-lookupPArrayFamInst ty = builtin parrayTyCon >>= (`lookupFamInst` [ty])
+polyVApply :: VExpr -> [Type] -> VM VExpr
+polyVApply expr tys
+ = do
+ dicts <- mapM paDictOfType tys
+ return $ mapVect (\e -> e `mkTyApps` tys `mkApps` dicts) expr
+
+hoistBinding :: Var -> CoreExpr -> VM ()
+hoistBinding v e = updGEnv $ \env ->
+ env { global_bindings = (v,e) : global_bindings env }
hoistExpr :: FastString -> CoreExpr -> VM Var
hoistExpr fs expr
= do
var <- newLocalVar fs (exprType expr)
- updGEnv $ \env ->
- env { global_bindings = (var, expr) : global_bindings env }
+ hoistBinding var expr
return var
-hoistPolyExpr :: FastString -> [TyVar] -> CoreExpr -> VM CoreExpr
-hoistPolyExpr fs tvs expr
+hoistVExpr :: VExpr -> VM VVar
+hoistVExpr (ve, le)
= do
- poly_expr <- closedV . polyAbstract tvs $ \abstract -> return (abstract expr)
- fn <- hoistExpr fs poly_expr
- polyApply (Var fn) (mkTyVarTys tvs)
+ fs <- getBindName
+ vv <- hoistExpr ('v' `consFS` fs) ve
+ lv <- hoistExpr ('l' `consFS` fs) le
+ return (vv, lv)
+
+hoistPolyVExpr :: [TyVar] -> VM VExpr -> VM VExpr
+hoistPolyVExpr tvs p
+ = do
+ expr <- closedV . polyAbstract tvs $ \abstract ->
+ liftM (mapVect abstract) p
+ fn <- hoistVExpr expr
+ polyVApply (vVar fn) (mkTyVarTys tvs)
takeHoisted :: VM [(Var, CoreExpr)]
takeHoisted
setGEnv $ env { global_bindings = [] }
return $ global_bindings env
-
-mkClosure :: Type -> Type -> Type -> CoreExpr -> CoreExpr -> CoreExpr -> CoreExpr -> VM CoreExpr
-mkClosure arg_ty res_ty env_ty pa_dict vfn lfn env
+mkClosure :: Type -> Type -> Type -> VExpr -> VExpr -> VM VExpr
+mkClosure arg_ty res_ty env_ty (vfn,lfn) (venv,lenv)
= do
- mk <- builtin mkClosureVar
- return $ Var mk `mkTyApps` [arg_ty, res_ty, env_ty] `mkApps` [pa_dict, vfn, lfn, env]
-
-mkClosureP :: Type -> Type -> Type -> CoreExpr -> CoreExpr -> CoreExpr -> CoreExpr -> VM CoreExpr
-mkClosureP arg_ty res_ty env_ty pa_dict vfn lfn env
+ dict <- paDictOfType env_ty
+ mkv <- builtin mkClosureVar
+ mkl <- builtin mkClosurePVar
+ return (Var mkv `mkTyApps` [arg_ty, res_ty, env_ty] `mkApps` [dict, vfn, lfn, venv],
+ Var mkl `mkTyApps` [arg_ty, res_ty, env_ty] `mkApps` [dict, vfn, lfn, lenv])
+
+mkClosureApp :: VExpr -> VExpr -> VM VExpr
+mkClosureApp (vclo, lclo) (varg, larg)
= do
- mk <- builtin mkClosurePVar
- return $ Var mk `mkTyApps` [arg_ty, res_ty, env_ty] `mkApps` [pa_dict, vfn, lfn, env]
+ vapply <- builtin applyClosureVar
+ lapply <- builtin applyClosurePVar
+ return (Var vapply `mkTyApps` [arg_ty, res_ty] `mkApps` [vclo, varg],
+ Var lapply `mkTyApps` [arg_ty, res_ty] `mkApps` [lclo, larg])
+ where
+ (arg_ty, res_ty) = splitClosureTy (exprType vclo)
+
+buildClosures :: [TyVar] -> [VVar] -> [Type] -> Type -> VM VExpr -> VM VExpr
+buildClosures tvs vars [] res_ty mk_body
+ = mk_body
+buildClosures tvs vars [arg_ty] res_ty mk_body
+ = buildClosure tvs vars arg_ty res_ty mk_body
+buildClosures tvs vars (arg_ty : arg_tys) res_ty mk_body
+ = do
+ res_ty' <- mkClosureTypes arg_tys res_ty
+ arg <- newLocalVVar FSLIT("x") arg_ty
+ buildClosure tvs vars arg_ty res_ty'
+ . hoistPolyVExpr tvs
+ $ do
+ lc <- builtin liftingContext
+ clo <- buildClosures tvs (vars ++ [arg]) arg_tys res_ty mk_body
+ return $ vLams lc (vars ++ [arg]) clo
-- (clo <x1,...,xn> <f,f^>, aclo (Arr lc xs1 ... xsn) <f,f^>)
-- where
-- f = \env v -> case env of <x1,...,xn> -> e x1 ... xn v
-- f^ = \env v -> case env of Arr l xs1 ... xsn -> e^ l x1 ... xn v
-
-buildClosure :: [TyVar] -> [(Var,Var)] -> (Var,Var) -> Var -> CoreExpr -> CoreExpr -> VM (CoreExpr, CoreExpr)
-buildClosure tvs env (varg, larg) lv vbody lbody
+--
+buildClosure :: [TyVar] -> [VVar] -> Type -> Type -> VM VExpr -> VM VExpr
+buildClosure tvs vars arg_ty res_ty mk_body
= do
- let (venv_ty, venv, bind_venv) = mkVectEnv tys vs
- (lenv, bind_lenv) <- mkLiftEnv (Var lv) tys ls
- lenv_ty <- mkPArrayType venv_ty
-
- venv_bndr <- newLocalVar FSLIT("env") venv_ty
- lenv_bndr <- newLocalVar FSLIT("env") lenv_ty
-
- let mono_vfn = mkLams [venv_bndr, varg]
- . bind_venv (Var venv_bndr)
- $ vbody `mkVarApps` vs `mkVarApps` [varg]
- mono_lfn = mkLams [lenv_bndr, larg]
- . bind_lenv (Var lenv_bndr) lv
- $ lbody `mkVarApps` (lv:ls) `mkVarApps` [larg]
-
- vfn <- hoistPolyExpr FSLIT("vfn") tvs mono_vfn
- lfn <- hoistPolyExpr FSLIT("lfn") tvs mono_lfn
-
- pa_dict <- paDictOfType venv_ty
-
- vclo <- mkClosure arg_ty res_ty venv_ty pa_dict vfn lfn venv
- lclo <- mkClosureP arg_ty res_ty venv_ty pa_dict vfn lfn lenv
-
- return (vclo, lclo)
-
+ (env_ty, env, bind) <- buildEnv vars
+ env_bndr <- newLocalVVar FSLIT("env") env_ty
+ arg_bndr <- newLocalVVar FSLIT("arg") arg_ty
+
+ fn <- hoistPolyVExpr tvs
+ $ do
+ lc <- builtin liftingContext
+ body <- mk_body
+ body' <- bind (vVar env_bndr)
+ (vVarApps lc body (vars ++ [arg_bndr]))
+ return (vLamsWithoutLC [env_bndr, arg_bndr] body')
+
+ mkClosure arg_ty res_ty env_ty fn env
+
+buildEnv :: [VVar] -> VM (Type, VExpr, VExpr -> VExpr -> VM VExpr)
+buildEnv vvs
+ = do
+ lc <- builtin liftingContext
+ let (ty, venv, vbind) = mkVectEnv tys vs
+ (lenv, lbind) <- mkLiftEnv lc tys ls
+ return (ty, (venv, lenv),
+ \(venv,lenv) (vbody,lbody) ->
+ do
+ let vbody' = vbind venv vbody
+ lbody' <- lbind lenv lbody
+ return (vbody', lbody'))
where
- vs = map fst env
- ls = map snd env
- tys = map idType vs
+ (vs,ls) = unzip vvs
+ tys = map idType vs
- arg_ty = idType varg
- res_ty = exprType vbody
-
mkVectEnv :: [Type] -> [Var] -> (Type, CoreExpr, CoreExpr -> CoreExpr -> CoreExpr)
mkVectEnv [] [] = (unitTy, Var unitDataConId, \env body -> body)
mkVectEnv [ty] [v] = (ty, Var v, \env body -> Let (NonRec v env) body)
where
ty = mkCoreTupTy tys
-mkLiftEnv :: CoreExpr -> [Type] -> [Var]
- -> VM (CoreExpr, CoreExpr -> Var -> CoreExpr -> CoreExpr)
+mkLiftEnv :: Var -> [Type] -> [Var] -> VM (CoreExpr, CoreExpr -> CoreExpr -> VM CoreExpr)
mkLiftEnv lc [ty] [v]
- = do
- len <- lengthPA (Var v)
- return (Var v, \env lv body -> Let (NonRec v env)
- $ Case len lv (exprType body) [(DEFAULT, [], body)])
+ = return (Var v, \env body ->
+ do
+ len <- lengthPA (Var v)
+ return . Let (NonRec v env)
+ $ Case len lc (exprType body) [(DEFAULT, [], body)])
-- NOTE: this transparently deals with empty environments
mkLiftEnv lc tys vs
= do
- (env_tc, env_tyargs) <- lookupPArrayFamInst vty
+ (env_tc, env_tyargs) <- parrayReprTyCon vty
let [env_con] = tyConDataCons env_tc
env = Var (dataConWrapId env_con)
- `mkTyApps` env_tyargs
- `mkApps` (lc : map Var vs)
-
- bind env lv body = let scrut = unwrapFamInstScrut env_tc env_tyargs env
- in
- Case scrut (mkWildId (exprType scrut)) (exprType body)
- [(DataAlt env_con, lv : vs, body)]
+ `mkTyApps` env_tyargs
+ `mkVarApps` (lc : vs)
+
+ bind env body = let scrut = unwrapFamInstScrut env_tc env_tyargs env
+ in
+ return $ Case scrut (mkWildId (exprType scrut))
+ (exprType body)
+ [(DataAlt env_con, lc : bndrs, body)]
return (env, bind)
where
vty = mkCoreTupTy tys
+ bndrs | null vs = [mkWildId unitTy]
+ | otherwise = vs
+