-{-# OPTIONS -w #-}
--- The above warning supression flag is a temporary kludge.
--- While working on this module you are encouraged to remove it and fix
--- any warnings in the module. See
--- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
--- for details
module Vectorise( vectorise )
where
-#include "HsVersions.h"
-
import VectMonad
import VectUtils
import VectType
import VectCore
-import DynFlags
-import HscTypes
+import HscTypes hiding ( MonadThings(..) )
-import CoreLint ( showPass, endPass )
+import Module ( PackageId )
import CoreSyn
import CoreUtils
+import CoreUnfold ( mkInlineRule )
+import MkCore ( mkWildCase )
import CoreFVs
-import SimplMonad ( SimplCount, zeroSimplCount )
-import Rules ( RuleBase )
+import CoreMonad ( CoreM, getHscEnv )
import DataCon
import TyCon
import Type
import FamInstEnv ( extendFamInstEnvList )
-import InstEnv ( extendInstEnvList )
import Var
import VarEnv
import VarSet
-import Name ( Name, mkSysTvName, getName )
-import NameEnv
import Id
-import MkId ( unwrapFamInstScrut )
import OccName
-import Module ( Module )
-
-import DsMonad hiding (mapAndUnzipM)
-import DsUtils ( mkCoreTup, mkCoreTupTy )
+import BasicTypes ( isLoopBreaker )
-import Literal ( Literal )
-import PrelNames
+import Literal ( Literal, mkMachInt )
import TysWiredIn
import TysPrim ( intPrimTy )
-import BasicTypes ( Boxity(..) )
import Outputable
import FastString
-import Control.Monad ( liftM, liftM2, zipWithM, mapAndUnzipM )
+import Util ( zipLazy )
+import Control.Monad
import Data.List ( sortBy, unzip4 )
-vectorise :: HscEnv -> UniqSupply -> RuleBase -> ModGuts
- -> IO (SimplCount, ModGuts)
-vectorise hsc_env _ _ guts
+vectorise :: PackageId -> ModGuts -> CoreM ModGuts
+vectorise backend guts = do
+ hsc_env <- getHscEnv
+ liftIO $ vectoriseIO backend hsc_env guts
+
+vectoriseIO :: PackageId -> HscEnv -> ModGuts -> IO ModGuts
+vectoriseIO backend hsc_env guts
= do
- showPass dflags "Vectorisation"
eps <- hscEPS hsc_env
let info = hptVectInfo hsc_env `plusVectInfo` eps_vect_info eps
- Just (info', guts') <- initV hsc_env guts info (vectModule guts)
- endPass dflags "Vectorisation" Opt_D_dump_vect (mg_binds guts')
- return (zeroSimplCount dflags, guts' { mg_vect_info = info' })
- where
- dflags = hsc_dflags hsc_env
+ Just (info', guts') <- initV backend hsc_env guts info (vectModule guts)
+ return (guts' { mg_vect_info = info' })
vectModule :: ModGuts -> VM ModGuts
vectModule guts
= do
(types', fam_insts, tc_binds) <- vectTypeEnv (mg_types guts)
-
+
let fam_inst_env' = extendFamInstEnvList (mg_fam_inst_env guts) fam_insts
updGEnv (setFamInstEnv fam_inst_env')
-
+
-- dicts <- mapM buildPADict pa_insts
-- workers <- mapM vectDataConWorkers pa_insts
binds' <- mapM vectTopBind (mg_binds guts)
vectTopBind :: CoreBind -> VM CoreBind
vectTopBind b@(NonRec var expr)
= do
- var' <- vectTopBinder var
- expr' <- vectTopRhs var expr
+ (inline, expr') <- vectTopRhs var expr
+ var' <- vectTopBinder var inline expr'
hs <- takeHoisted
cexpr <- tryConvert var var' expr
return . Rec $ (var, cexpr) : (var', expr') : hs
vectTopBind b@(Rec bs)
= do
- vars' <- mapM vectTopBinder vars
- exprs' <- zipWithM vectTopRhs vars exprs
+ (vars', _, exprs') <- fixV $ \ ~(_, inlines, rhss) ->
+ do
+ vars' <- sequence [vectTopBinder var inline rhs
+ | (var, ~(inline, rhs))
+ <- zipLazy vars (zip inlines rhss)]
+ (inlines', exprs') <- mapAndUnzipM (uncurry vectTopRhs) bs
+ return (vars', inlines', exprs')
hs <- takeHoisted
cexprs <- sequence $ zipWith3 tryConvert vars vars' exprs
return . Rec $ zip vars cexprs ++ zip vars' exprs' ++ hs
where
(vars, exprs) = unzip bs
-vectTopBinder :: Var -> VM Var
-vectTopBinder var
+-- NOTE: vectTopBinder *MUST* be lazy in inline and expr because of how it is
+-- used inside of fixV in vectTopBind
+vectTopBinder :: Var -> Inline -> CoreExpr -> VM Var
+vectTopBinder var inline expr
= do
vty <- vectType (idType var)
- var' <- cloneId mkVectOcc var vty
+ var' <- liftM (`setIdUnfolding` unfolding) $ cloneId mkVectOcc var vty
defGlobalVar var var'
return var'
-
-vectTopRhs :: Var -> CoreExpr -> VM CoreExpr
+ where
+ unfolding = case inline of
+ Inline arity -> mkInlineRule expr (Just arity)
+ DontInline -> noUnfolding
+
+vectTopRhs :: Var -> CoreExpr -> VM (Inline, CoreExpr)
vectTopRhs var expr
- = do
- closedV . liftM vectorised
- . inBind var
- $ vectPolyExpr (freeVars expr)
+ = closedV
+ $ do
+ (inline, vexpr) <- inBind var
+ $ vectPolyExpr (isLoopBreaker $ idOccInfo var)
+ (freeVars expr)
+ return (inline, vectorised vexpr)
tryConvert :: Var -> Var -> CoreExpr -> VM CoreExpr
tryConvert var vect_var rhs
vectBndr :: Var -> VM VVar
vectBndr v
= do
- vty <- vectType (idType v)
- lty <- mkPArrayType vty
+ (vty, lty) <- vectAndLiftType (idType v)
let vv = v `Id.setIdType` vty
lv = v `Id.setIdType` lty
updLEnv (mapTo vv lv)
x <- p
return (vv, x)
-vectBndrIn' :: Var -> (VVar -> VM a) -> VM (VVar, a)
-vectBndrIn' v p
- = localV
- $ do
- vv <- vectBndr v
- x <- p vv
- return (vv, x)
-
vectBndrsIn :: [Var] -> VM a -> VM ([VVar], a)
vectBndrsIn vs p
= localV
Local (vv,lv) -> return (Var vv, Var lv)
Global vv -> do
let vexpr = Var vv
- lexpr <- liftPA vexpr
+ lexpr <- liftPD vexpr
return (vexpr, lexpr)
vectPolyVar :: Var -> [Type] -> VM VExpr
(polyApply (Var lv) vtys)
Global poly -> do
vexpr <- polyApply (Var poly) vtys
- lexpr <- liftPA vexpr
+ lexpr <- liftPD vexpr
return (vexpr, lexpr)
vectLiteral :: Literal -> VM VExpr
vectLiteral lit
= do
- lexpr <- liftPA (Lit lit)
+ lexpr <- liftPD (Lit lit)
return (Lit lit, lexpr)
-vectPolyExpr :: CoreExprWithFVs -> VM VExpr
-vectPolyExpr expr
- = polyAbstract tvs $ \abstract ->
- do
- mono' <- vectExpr mono
- return $ mapVect abstract mono'
+vectPolyExpr :: Bool -> CoreExprWithFVs -> VM (Inline, VExpr)
+vectPolyExpr loop_breaker (_, AnnNote note expr)
+ = do
+ (inline, expr') <- vectPolyExpr loop_breaker expr
+ return (inline, vNote note expr')
+vectPolyExpr loop_breaker expr
+ = do
+ arity <- polyArity tvs
+ polyAbstract tvs $ \args ->
+ do
+ (inline, mono') <- vectFnExpr False loop_breaker mono
+ return (addInlineArity inline arity,
+ mapVect (mkLams $ tvs ++ args) mono')
where
- (tvs, mono) = collectAnnTypeBinders expr
-
+ (tvs, mono) = collectAnnTypeBinders expr
+
vectExpr :: CoreExprWithFVs -> VM VExpr
vectExpr (_, AnnType ty)
= liftM vType (vectType ty)
where
(fn, tys) = collectAnnTypeArgs e
+vectExpr (_, AnnApp (_, AnnVar v) (_, AnnLit lit))
+ | Just con <- isDataConId_maybe v
+ , is_special_con con
+ = do
+ let vexpr = App (Var v) (Lit lit)
+ lexpr <- liftPD vexpr
+ return (vexpr, lexpr)
+ where
+ is_special_con con = con `elem` [intDataCon, floatDataCon, doubleDataCon]
+
+
vectExpr (_, AnnApp fn arg)
= do
arg_ty' <- vectType arg_ty
where
scrut_ty = exprType (deAnnotate scrut)
-vectExpr (_, AnnCase expr bndr ty alts)
- = panic "vectExpr: case"
-
vectExpr (_, AnnLet (AnnNonRec bndr rhs) body)
= do
- vrhs <- localV . inBind bndr $ vectPolyExpr rhs
+ vrhs <- localV . inBind bndr . liftM snd $ vectPolyExpr False rhs
(vbndr, vbody) <- vectBndrIn bndr (vectExpr body)
return $ vLet (vNonRec vbndr vrhs) vbody
(vbndrs, (vrhss, vbody)) <- vectBndrsIn bndrs
$ liftM2 (,)
(zipWithM vect_rhs bndrs rhss)
- (vectPolyExpr body)
+ (vectExpr body)
return $ vLet (vRec vbndrs vrhss) vbody
where
(bndrs, rhss) = unzip bs
vect_rhs bndr rhs = localV
. inBind bndr
- $ vectExpr rhs
+ . liftM snd
+ $ vectPolyExpr (isLoopBreaker $ idOccInfo bndr) rhs
+
+vectExpr e@(_, AnnLam bndr _)
+ | isId bndr = liftM snd $ vectFnExpr True False e
+{-
+onlyIfV (isEmptyVarSet fvs) (vectScalarLam bs $ deAnnotate body)
+ `orElseV` vectLam True fvs bs body
+ where
+ (bs,body) = collectAnnValBinders e
+-}
-vectExpr e@(fvs, AnnLam bndr _)
- | not (isId bndr) = pprPanic "vectExpr" (ppr $ deAnnotate e)
- | otherwise = vectLam fvs bs body
+vectExpr e = cantVectorise "Can't vectorise expression" (ppr $ deAnnotate e)
+
+vectFnExpr :: Bool -> Bool -> CoreExprWithFVs -> VM (Inline, VExpr)
+vectFnExpr inline loop_breaker e@(fvs, AnnLam bndr _)
+ | isId bndr = onlyIfV (isEmptyVarSet fvs)
+ (mark DontInline . vectScalarLam bs $ deAnnotate body)
+ `orElseV` mark inlineMe (vectLam inline loop_breaker fvs bs body)
where
(bs,body) = collectAnnValBinders e
+vectFnExpr _ _ e = mark DontInline $ vectExpr e
+
+mark :: Inline -> VM a -> VM (Inline, a)
+mark b p = do { x <- p; return (b,x) }
-vectLam :: VarSet -> [Var] -> CoreExprWithFVs -> VM VExpr
-vectLam fvs bs body
+vectScalarLam :: [Var] -> CoreExpr -> VM VExpr
+vectScalarLam args body
+ = do
+ scalars <- globalScalars
+ onlyIfV (all is_scalar_ty arg_tys
+ && is_scalar_ty res_ty
+ && is_scalar (extendVarSetList scalars args) body)
+ $ do
+ fn_var <- hoistExpr (fsLit "fn") (mkLams args body) DontInline
+ zipf <- zipScalars arg_tys res_ty
+ clo <- scalarClosure arg_tys res_ty (Var fn_var)
+ (zipf `App` Var fn_var)
+ clo_var <- hoistExpr (fsLit "clo") clo DontInline
+ lclo <- liftPD (Var clo_var)
+ return (Var clo_var, lclo)
+ where
+ arg_tys = map idType args
+ res_ty = exprType body
+
+ is_scalar_ty ty | Just (tycon, []) <- splitTyConApp_maybe ty
+ = tycon == intTyCon
+ || tycon == floatTyCon
+ || tycon == doubleTyCon
+
+ | otherwise = False
+
+ is_scalar vs (Var v) = v `elemVarSet` vs
+ is_scalar _ e@(Lit _) = is_scalar_ty $ exprType e
+ is_scalar vs (App e1 e2) = is_scalar vs e1 && is_scalar vs e2
+ is_scalar _ _ = False
+
+vectLam :: Bool -> Bool -> VarSet -> [Var] -> CoreExprWithFVs -> VM VExpr
+vectLam inline loop_breaker fvs bs body
= do
tyvars <- localTyVars
(vs, vvs) <- readLEnv $ \env ->
res_ty <- vectType (exprType $ deAnnotate body)
buildClosures tyvars vvs arg_tys res_ty
- . hoistPolyVExpr tyvars
+ . hoistPolyVExpr tyvars (maybe_inline (length vs + length bs))
$ do
lc <- builtin liftingContext
(vbndrs, vbody) <- vectBndrsIn (vs ++ bs)
(vectExpr body)
- return $ vLams lc vbndrs vbody
-
+ vbody' <- break_loop lc res_ty vbody
+ return $ vLams lc vbndrs vbody'
+ where
+ maybe_inline n | inline = Inline n
+ | otherwise = DontInline
+
+ break_loop lc ty (ve, le)
+ | loop_breaker
+ = do
+ empty <- emptyPD ty
+ lty <- mkPDataType ty
+ return (ve, mkWildCase (Var lc) intPrimTy lty
+ [(DEFAULT, [], le),
+ (LitAlt (mkMachInt 0), [], empty)])
+
+ | otherwise = return (ve, le)
+
+
vectTyAppExpr :: CoreExprWithFVs -> [Type] -> VM VExpr
vectTyAppExpr (_, AnnVar v) tys = vectPolyVar v tys
-vectTyAppExpr e tys = pprPanic "vectTyAppExpr" (ppr $ deAnnotate e)
-
-type CoreAltWithFVs = AnnAlt Id VarSet
+vectTyAppExpr e tys = cantVectorise "Can't vectorise expression"
+ (ppr $ deAnnotate e `mkTyApps` tys)
-- We convert
--
-- When lifting, we have to do it this way because v must have the type
-- [:V(T):] but the scrutinee must be cast to the representation type. We also
-- have to handle the case where v is a wild var correctly.
---
+--
-- FIXME: this is too lazy
-vectAlgCase tycon ty_args scrut bndr ty [(DEFAULT, [], body)]
+vectAlgCase :: TyCon -> [Type] -> CoreExprWithFVs -> Var -> Type
+ -> [(AltCon, [Var], CoreExprWithFVs)]
+ -> VM VExpr
+vectAlgCase _tycon _ty_args scrut bndr ty [(DEFAULT, [], body)]
= do
- vscrut <- vectExpr scrut
- vty <- vectType ty
- lty <- mkPArrayType vty
+ vscrut <- vectExpr scrut
+ (vty, lty) <- vectAndLiftType ty
(vbndr, vbody) <- vectBndrIn bndr (vectExpr body)
return $ vCaseDEFAULT vscrut vbndr vty lty vbody
-vectAlgCase tycon ty_args scrut bndr ty [(DataAlt dc, bndrs, body)]
+vectAlgCase _tycon _ty_args scrut bndr ty [(DataAlt _, [], body)]
= do
- vect_tc <- maybeV (lookupTyCon tycon)
- vty <- vectType ty
- lty <- mkPArrayType vty
- vexpr <- vectExpr scrut
- (vbndr, (vbndrs, vbody)) <- vect_scrut_bndr
- . vectBndrsIn bndrs
- $ vectExpr body
+ vscrut <- vectExpr scrut
+ (vty, lty) <- vectAndLiftType ty
+ (vbndr, vbody) <- vectBndrIn bndr (vectExpr body)
+ return $ vCaseDEFAULT vscrut vbndr vty lty vbody
- (vscrut, arr_tc, arg_tys) <- mkVScrut (vVar vbndr)
+vectAlgCase _tycon _ty_args scrut bndr ty [(DataAlt dc, bndrs, body)]
+ = do
+ (vty, lty) <- vectAndLiftType ty
+ vexpr <- vectExpr scrut
+ (vbndr, (vbndrs, (vect_body, lift_body)))
+ <- vect_scrut_bndr
+ . vectBndrsIn bndrs
+ $ vectExpr body
+ let (vect_bndrs, lift_bndrs) = unzip vbndrs
+ (vscrut, lscrut, pdata_tc, _arg_tys) <- mkVScrut (vVar vbndr)
vect_dc <- maybeV (lookupDataCon dc)
- let [arr_dc] = tyConDataCons arr_tc
- repr <- mkRepr vect_tc
- shape_bndrs <- arrShapeVars repr
- return . vLet (vNonRec vbndr vexpr)
- $ vCaseProd vscrut vty lty vect_dc arr_dc shape_bndrs vbndrs vbody
+ let [pdata_dc] = tyConDataCons pdata_tc
+
+ let vcase = mk_wild_case vscrut vty vect_dc vect_bndrs vect_body
+ lcase = mk_wild_case lscrut lty pdata_dc lift_bndrs lift_body
+
+ return $ vLet (vNonRec vbndr vexpr) (vcase, lcase)
where
- vect_scrut_bndr | isDeadBinder bndr = vectBndrNewIn bndr FSLIT("scrut")
+ vect_scrut_bndr | isDeadBinder bndr = vectBndrNewIn bndr (fsLit "scrut")
| otherwise = vectBndrIn bndr
-vectAlgCase tycon ty_args scrut bndr ty alts
+ mk_wild_case expr ty dc bndrs body
+ = mkWildCase expr (exprType expr) ty [(DataAlt dc, bndrs, body)]
+
+vectAlgCase tycon _ty_args scrut bndr ty alts
= do
- vect_tc <- maybeV (lookupTyCon tycon)
- vty <- vectType ty
- lty <- mkPArrayType vty
+ vect_tc <- maybeV (lookupTyCon tycon)
+ (vty, lty) <- vectAndLiftType ty
- repr <- mkRepr vect_tc
- shape_bndrs <- arrShapeVars repr
- (len, sel, indices) <- arrSelector repr (map Var shape_bndrs)
+ let arity = length (tyConDataCons vect_tc)
+ sel_ty <- builtin (selTy arity)
+ sel_bndr <- newLocalVar (fsLit "sel") sel_ty
+ let sel = Var sel_bndr
- (vbndr, valts) <- vect_scrut_bndr $ mapM (proc_alt sel lty) alts'
+ (vbndr, valts) <- vect_scrut_bndr
+ $ mapM (proc_alt arity sel vty lty) alts'
let (vect_dcs, vect_bndrss, lift_bndrss, vbodies) = unzip4 valts
vexpr <- vectExpr scrut
- (vscrut, arr_tc, arg_tys) <- mkVScrut (vVar vbndr)
- let [arr_dc] = tyConDataCons arr_tc
+ (vect_scrut, lift_scrut, pdata_tc, _arg_tys) <- mkVScrut (vVar vbndr)
+ let [pdata_dc] = tyConDataCons pdata_tc
- let (vect_scrut, lift_scrut) = vscrut
- (vect_bodies, lift_bodies) = unzip vbodies
+ let (vect_bodies, lift_bodies) = unzip vbodies
- let vect_case = Case vect_scrut (mkWildId (exprType vect_scrut)) vty
+ vdummy <- newDummyVar (exprType vect_scrut)
+ ldummy <- newDummyVar (exprType lift_scrut)
+ let vect_case = Case vect_scrut vdummy vty
(zipWith3 mk_vect_alt vect_dcs vect_bndrss vect_bodies)
- lbody <- combinePA vty len sel indices lift_bodies
- let lift_case = Case lift_scrut (mkWildId (exprType lift_scrut)) lty
- [(DataAlt arr_dc, shape_bndrs ++ concat lift_bndrss,
+ lc <- builtin liftingContext
+ lbody <- combinePD vty (Var lc) sel lift_bodies
+ let lift_case = Case lift_scrut ldummy lty
+ [(DataAlt pdata_dc, sel_bndr : concat lift_bndrss,
lbody)]
return . vLet (vNonRec vbndr vexpr)
$ (vect_case, lift_case)
where
- vect_scrut_bndr | isDeadBinder bndr = vectBndrNewIn bndr FSLIT("scrut")
+ vect_scrut_bndr | isDeadBinder bndr = vectBndrNewIn bndr (fsLit "scrut")
| otherwise = vectBndrIn bndr
alts' = sortBy (\(alt1, _, _) (alt2, _, _) -> cmp alt1 alt2) alts
cmp DEFAULT DEFAULT = EQ
cmp DEFAULT _ = LT
cmp _ DEFAULT = GT
+ cmp _ _ = panic "vectAlgCase/cmp"
- proc_alt sel lty (DataAlt dc, bndrs, body)
+ proc_alt arity sel _ lty (DataAlt dc, bndrs, body)
= do
vect_dc <- maybeV (lookupDataCon dc)
- let tag = mkDataConTag vect_dc
- fvs = freeVarsOf body `delVarSetList` bndrs
- (vect_bndrs, lift_bndrs, vbody)
- <- vect_alt_bndrs bndrs
- $ \len -> packLiftingContext len sel tag fvs lty
- $ vectExpr body
-
+ let ntag = dataConTagZ vect_dc
+ tag = mkDataConTag vect_dc
+ fvs = freeVarsOf body `delVarSetList` bndrs
+
+ sel_tags <- liftM (`App` sel) (builtin (selTags arity))
+ lc <- builtin liftingContext
+ elems <- builtin (selElements arity ntag)
+
+ (vbndrs, vbody)
+ <- vectBndrsIn bndrs
+ . localV
+ $ do
+ binds <- mapM (pack_var (Var lc) sel_tags tag)
+ . filter isLocalId
+ $ varSetElems fvs
+ (ve, le) <- vectExpr body
+ return (ve, Case (elems `App` sel) lc lty
+ [(DEFAULT, [], (mkLets (concat binds) le))])
+ -- empty <- emptyPD vty
+ -- return (ve, Case (elems `App` sel) lc lty
+ -- [(DEFAULT, [], Let (NonRec flags_var flags_expr)
+ -- $ mkLets (concat binds) le),
+ -- (LitAlt (mkMachInt 0), [], empty)])
+ let (vect_bndrs, lift_bndrs) = unzip vbndrs
return (vect_dc, vect_bndrs, lift_bndrs, vbody)
- vect_alt_bndrs [] p
- = do
- void_tc <- builtin voidTyCon
- let void_ty = mkTyConApp void_tc []
- arr_ty <- mkPArrayType void_ty
- bndr <- newLocalVar FSLIT("voids") arr_ty
- len <- lengthPA void_ty (Var bndr)
- e <- p len
- return ([], [bndr], e)
-
- vect_alt_bndrs bndrs p
- = localV
- $ do
- vbndrs <- mapM vectBndr bndrs
- let (vect_bndrs, lift_bndrs) = unzip vbndrs
- vv : _ = vect_bndrs
- lv : _ = lift_bndrs
- len <- lengthPA (idType vv) (Var lv)
- e <- p len
- return (vect_bndrs, lift_bndrs, e)
+ proc_alt _ _ _ _ _ = panic "vectAlgCase/proc_alt"
mk_vect_alt vect_dc bndrs body = (DataAlt vect_dc, bndrs, body)
-packLiftingContext :: CoreExpr -> CoreExpr -> CoreExpr -> VarSet -> Type -> VM VExpr -> VM VExpr
-packLiftingContext len shape tag fvs res_ty p
- = do
- select <- builtin selectPAIntPrimVar
- let sel_expr = mkApps (Var select) [shape, tag]
- sel_var <- newLocalVar FSLIT("sel#") (exprType sel_expr)
- lc_var <- builtin liftingContext
- localV $
- do
- bnds <- mapM (packFreeVar (Var lc_var) (Var sel_var))
- . filter isLocalId
- $ varSetElems fvs
- (vexpr, lexpr) <- p
- return (vexpr, Let (NonRec sel_var sel_expr)
- . mkLets (concat bnds)
- $ Case len lc_var res_ty [(DEFAULT, [], lexpr)])
-
-packFreeVar :: CoreExpr -> CoreExpr -> Var -> VM [CoreBind]
-packFreeVar len sel v
- = do
- r <- lookupVar v
- case r of
- Local (vv,lv) ->
- do
- lv' <- cloneVar lv
- expr <- packPA (idType vv) (Var lv) len sel
- updLEnv (upd vv lv')
- return [(NonRec lv' expr)]
-
- _ -> return []
- where
- upd vv lv' env = env { local_vars = extendVarEnv (local_vars env) v (vv, lv') }
+ pack_var len tags t v
+ = do
+ r <- lookupVar v
+ case r of
+ Local (vv, lv) ->
+ do
+ lv' <- cloneVar lv
+ expr <- packByTagPD (idType vv) (Var lv) len tags t
+ updLEnv (\env -> env { local_vars = extendVarEnv
+ (local_vars env) v (vv, lv') })
+ return [(NonRec lv' expr)]
+
+ _ -> return []