module CLaSH.Normalize.Transformations
( appProp
, bindNonRep
, liftNonRep
, caseLet
, caseCon
, caseCase
, inlineNonRep
, typeSpec
, nonRepSpec
, etaExpansionTL
, nonRepANF
, bindConstantVar
, constantSpec
, makeANF
, deadCode
, topLet
, recToLetRec
, inlineClosed
, inlineHO
, inlineSmall
, simpleCSE
, reduceConst
)
where
import qualified Control.Lens as Lens
import qualified Control.Monad as Monad
import Control.Monad.Writer (WriterT (..), lift, tell)
import qualified Data.Either as Either
import qualified Data.HashMap.Lazy as HashMap
import qualified Data.List as List
import qualified Data.Maybe as Maybe
import Unbound.Generics.LocallyNameless (Bind, Embed (..), bind, embed,
rec, unbind, unembed, unrebind,
unrec, name2String)
import Unbound.Generics.LocallyNameless.Unsafe (unsafeUnbind)
import CLaSH.Core.DataCon (DataCon, dcName, dcTag,
dcUnivTyVars)
import CLaSH.Core.FreeVars (termFreeIds, termFreeTyVars,
typeFreeVars)
import CLaSH.Core.Pretty (showDoc)
import CLaSH.Core.Subst (substTm, substTms, substTyInTm,
substTysinTm)
import CLaSH.Core.Term (LetBinding, Pat (..), Term (..))
import CLaSH.Core.Type (TypeView (..), applyFunTy,
applyTy, splitFunTy, typeKind, tyView)
import CLaSH.Core.Util (collectArgs, idToVar, isCon,
isFun, isLet, isPolyFun, isPrim,
isVar, mkApps, mkLams, mkTmApps,
termSize,termType)
import CLaSH.Core.Var (Id, Var (..))
import CLaSH.Netlist.Util (representableType,
splitNormalized)
import CLaSH.Normalize.Types
import CLaSH.Normalize.Util
import CLaSH.Rewrite.Combinators
import CLaSH.Rewrite.Types
import CLaSH.Rewrite.Util
import CLaSH.Util
bindNonRep :: NormRewrite
bindNonRep = inlineBinders nonRepTest
where
nonRepTest (Id idName tyE, exprE)
= (&&) <$> (not <$> (representableType <$> Lens.use typeTranslator <*> Lens.use tcCache <*> pure (unembed tyE)))
<*> (notElem idName <$> (Lens.toListOf <$> localFreeIds <*> pure (unembed exprE)))
nonRepTest _ = return False
liftNonRep :: NormRewrite
liftNonRep = liftBinders nonRepTest
where
nonRepTest (Id idName tyE, exprE)
= (&&) <$> (not <$> (representableType <$> Lens.use typeTranslator <*> Lens.use tcCache <*> pure (unembed tyE)))
<*> (elem idName <$> (Lens.toListOf <$> localFreeIds <*> pure (unembed exprE)))
nonRepTest _ = return False
typeSpec :: NormRewrite
typeSpec ctx e@(TyApp e1 ty)
| (Var _ _, args) <- collectArgs e1
, null $ Lens.toListOf typeFreeVars ty
, (_, []) <- Either.partitionEithers args
= specializeNorm False ctx e
typeSpec _ e = return e
nonRepSpec :: NormRewrite
nonRepSpec ctx e@(App e1 e2)
| (Var _ _, args) <- collectArgs e1
, (_, []) <- Either.partitionEithers args
, null $ Lens.toListOf termFreeTyVars e2
= R $ do tcm <- Lens.use tcCache
e2Ty <- termType tcm e2
localVar <- isLocalVar e2
nonRepE2 <- not <$> (representableType <$> Lens.use typeTranslator <*> Lens.use tcCache <*> pure e2Ty)
if nonRepE2 && not localVar
then runR $ specializeNorm True ctx e
else return e
nonRepSpec _ e = return e
caseLet :: NormRewrite
caseLet _ (Case (Letrec b) ty alts) = R $ do
(xes,e) <- unbind b
changed . Letrec $ bind xes (Case e ty alts)
caseLet _ e = return e
caseCase :: NormRewrite
caseCase _ e@(Case (Case scrut alts1Ty alts1) alts2Ty alts2)
= R $ do
ty1Rep <- representableType <$> Lens.use typeTranslator <*> Lens.use tcCache <*> pure alts1Ty
if not ty1Rep
then do newAlts <- mapM ( return
. uncurry bind
. second (\altE -> Case altE alts2Ty alts2)
<=< unbind
) alts1
changed $ Case scrut alts2Ty newAlts
else return e
caseCase _ e = return e
inlineNonRep :: NormRewrite
inlineNonRep _ e@(Case scrut altsTy alts)
| (Var _ f, args) <- collectArgs scrut
= R $ do
isInlined <- liftR $ alreadyInlined f
limit <- liftR $ Lens.use inlineLimit
tcm <- Lens.use tcCache
scrutTy <- termType tcm scrut
let noException = not (exception tcm scrutTy)
if noException && (Maybe.fromMaybe 0 isInlined) > limit
then do
cf <- liftR $ Lens.use curFun
ty <- termType tcm scrut
traceIf True (concat [$(curLoc) ++ "InlineNonRep: " ++ show f
," already inlined " ++ show limit ++ " times in:"
, show cf
, "\nType of the subject is: " ++ showDoc ty
, "\nFunction " ++ show cf
, "will not reach a normal form, and compilation"
, "might fail."
, "\nRun with '-clash-inline-limit=N' to increase"
, "the inlining limit to N."
])
(return e)
else do
bodyMaybe <- fmap (HashMap.lookup f) $ Lens.use bindings
nonRepScrut <- not <$> (representableType <$> Lens.use typeTranslator <*> Lens.use tcCache <*> pure scrutTy)
case (nonRepScrut, bodyMaybe) of
(True,Just (_, scrutBody)) -> do
Monad.when noException (liftR $ addNewInline f)
changed $ Case (mkApps scrutBody args) altsTy alts
_ -> return e
where
exception tcm ((tyView . typeKind tcm) -> TyConApp (name2String -> "GHC.Prim.Constraint") _) = True
exception _ _ = False
inlineNonRep _ e = return e
caseCon :: NormRewrite
caseCon _ c@(Case scrut _ alts)
| (Data dc, args) <- collectArgs scrut
= R $ do
alts' <- mapM unbind alts
let dcAltM = List.find (equalCon dc . fst) alts'
case dcAltM of
Just (DataPat _ pxs, e) ->
let (tvs,xs) = unrebind pxs
fvs = Lens.toListOf termFreeIds e
(binds,_) = List.partition ((`elem` fvs) . varName . fst)
$ zip xs (Either.lefts args)
e' = case binds of
[] -> e
_ -> Letrec $ bind (rec $ map (second embed) binds) e
substTyMap = zip (map varName tvs) (drop (length $ dcUnivTyVars dc) (Either.rights args))
in changed (substTysinTm substTyMap e')
_ -> case alts' of
((DefaultPat,e):_) -> changed e
_ -> error $ $(curLoc) ++ "Report as bug: caseCon error: " ++ showDoc c
where
equalCon dc (DataPat dc' _) = dcTag dc == dcTag (unembed dc')
equalCon _ _ = False
caseCon _ c@(Case (Literal l) _ alts) = R $ do
alts' <- mapM unbind alts
let ltAltsM = List.find (equalLit . fst) alts'
case ltAltsM of
Just (LitPat _,e) -> changed e
_ -> case alts' of
((DefaultPat,e):_) -> changed e
_ -> error $ $(curLoc) ++ "Report as bug: caseCon error: " ++ showDoc c
where
equalLit (LitPat l') = l == (unembed l')
equalLit _ = False
caseCon ctx e@(Case subj ty alts)
| isConstant subj = do
tcm <- Lens.use tcCache
lvl <- Lens.view dbgLevel
reduceConstant <- Lens.use evaluator
case reduceConstant tcm subj of
Literal l -> caseCon ctx (Case (Literal l) ty alts)
subj'@(collectArgs -> (Data _,_)) -> caseCon ctx (Case subj' ty alts)
subj' -> traceIf (lvl > DebugNone) ("Irreducible constant as case subject: " ++ showDoc subj ++ "\nCan be reduced to: " ++ showDoc subj') (caseOneAlt e)
caseCon _ e = caseOneAlt e
caseOneAlt :: Monad m => Term -> R m Term
caseOneAlt e@(Case _ _ [alt]) = R $ do
(pat,altE) <- unbind alt
case pat of
DefaultPat -> changed altE
LitPat _ -> changed altE
DataPat _ pxs -> let (tvs,xs) = unrebind pxs
ftvs = Lens.toListOf termFreeTyVars altE
fvs = Lens.toListOf termFreeIds altE
usedTvs = filter ((`elem` ftvs) . varName) tvs
usedXs = filter ((`elem` fvs) . varName) xs
in case (usedTvs,usedXs) of
([],[]) -> changed altE
_ -> return e
caseOneAlt e = return e
nonRepANF :: NormRewrite
nonRepANF ctx e@(App appConPrim arg)
| (conPrim, _) <- collectArgs e
, isCon conPrim || isPrim conPrim
= R $ do
untranslatable <- isUntranslatable arg
case (untranslatable,arg) of
(True,Letrec b) -> do (binds,body) <- unbind b
changed . Letrec $ bind binds (App appConPrim body)
(True,Case {}) -> runR $ specializeNorm True ctx e
(True,Lam _) -> runR $ specializeNorm True ctx e
_ -> return e
nonRepANF _ e = return e
topLet :: NormRewrite
topLet ctx e
| all isLambdaBodyCtx ctx && not (isLet e)
= R $ do
untranslatable <- isUntranslatable e
if untranslatable
then return e
else do tcm <- Lens.use tcCache
(argId,argVar) <- mkTmBinderFor tcm "topLet" e
changed . Letrec $ bind (rec [(argId,embed e)]) argVar
topLet ctx e@(Letrec b)
| all isLambdaBodyCtx ctx
= R $ do
(binds,body) <- unbind b
localVar <- isLocalVar body
untranslatable <- isUntranslatable body
if localVar || untranslatable
then return e
else do tcm <- Lens.use tcCache
(argId,argVar) <- mkTmBinderFor tcm "topLet" body
changed . Letrec $ bind (rec $ unrec binds ++ [(argId,embed body)]) argVar
topLet _ e = return e
deadCode :: NormRewrite
deadCode _ e@(Letrec binds) = R $ do
(xes, body) <- fmap (first unrec) $ unbind binds
let bodyFVs = Lens.toListOf termFreeIds body
(xesUsed,xesOther) = List.partition
( (`elem` bodyFVs )
. varName
. fst
) xes
xesUsed' = findUsedBndrs [] xesUsed xesOther
if length xesUsed' /= length xes
then changed . Letrec $ bind (rec xesUsed') body
else return e
where
findUsedBndrs used [] _ = used
findUsedBndrs used explore other =
let fvsUsed = concatMap (Lens.toListOf termFreeIds . unembed . snd) explore
(explore',other') = List.partition
( (`elem` fvsUsed)
. varName
. fst
) other
in findUsedBndrs (used ++ explore) explore' other'
deadCode _ e = return e
bindConstantVar :: NormRewrite
bindConstantVar = inlineBinders test
where
test (_,Embed e) = (||) <$> isLocalVar e <*> pure (isConstant e)
inlineClosed :: NormRewrite
inlineClosed _ e@(collectArgs -> (Var _ f,args))
| all (either isConstant (const True)) args
= R $ do
untranslatable <- isUntranslatable e
if untranslatable
then return e
else do
bndrs <- Lens.use bindings
case HashMap.lookup f bndrs of
Just (_,body) -> let cg = callGraph [] bndrs f
in if null (recursiveComponents cg)
then changed (mkApps body args)
else return e
_ -> return e
inlineClosed _ e@(Var _ f) = R $ do
tcm <- Lens.use tcCache
closed <- isClosed tcm e
untranslatable <- isUntranslatable e
if closed && not untranslatable
then do
bndrs <- Lens.use bindings
case HashMap.lookup f bndrs of
Just (_,body) -> let cg = callGraph [] bndrs f
in if null (recursiveComponents cg)
then changed body
else return e
_ -> return e
else return e
inlineClosed _ e = return e
inlineSmall :: NormRewrite
inlineSmall _ e@(collectArgs -> (Var _ f,args)) = R $ do
untranslatable <- isUntranslatable e
if untranslatable
then return e
else do
bndrs <- Lens.use bindings
sizeLimit <- liftR $ Lens.use inlineBelow
case HashMap.lookup f bndrs of
Just (_,body) -> let cg = callGraph [] bndrs f
in if null (recursiveComponents cg) &&
termSize body < sizeLimit
then changed (mkApps body args)
else return e
_ -> return e
inlineSmall _ e = return e
constantSpec :: NormRewrite
constantSpec ctx e@(App e1 e2)
| (Var _ _, args) <- collectArgs e1
, (_, []) <- Either.partitionEithers args
, null $ Lens.toListOf termFreeTyVars e2
, isConstant e2
= specializeNorm False ctx e
constantSpec _ e = return e
appProp :: NormRewrite
appProp _ (App (Lam b) arg) = R $ do
(v,e) <- unbind b
if isConstant arg || isVar arg
then changed $ substTm (varName v) arg e
else changed . Letrec $ bind (rec [(v,embed arg)]) e
appProp _ (App (Letrec b) arg) = R $ do
(v,e) <- unbind b
changed . Letrec $ bind v (App e arg)
appProp _ (App (Case scrut ty alts) arg) = R $ do
tcm <- Lens.use tcCache
argTy <- termType tcm arg
let ty' = applyFunTy tcm ty argTy
if isConstant arg || isVar arg
then do
alts' <- mapM ( return
. uncurry bind
. second (`App` arg)
<=< unbind
) alts
changed $ Case scrut ty' alts'
else do
(boundArg,argVar) <- mkTmBinderFor tcm "caseApp" arg
alts' <- mapM ( return
. uncurry bind
. second (`App` argVar)
<=< unbind
) alts
changed . Letrec $ bind (rec [(boundArg,embed arg)]) (Case scrut ty' alts')
appProp _ (TyApp (TyLam b) t) = R $ do
(tv,e) <- unbind b
changed $ substTyInTm (varName tv) t e
appProp _ (TyApp (Letrec b) t) = R $ do
(v,e) <- unbind b
changed . Letrec $ bind v (TyApp e t)
appProp _ (TyApp (Case scrut altsTy alts) ty) = R $ do
alts' <- mapM ( return
. uncurry bind
. second (`TyApp` ty)
<=< unbind
) alts
tcm <- Lens.use tcCache
ty' <- applyTy tcm altsTy ty
changed $ Case scrut ty' alts'
appProp _ e = return e
type NormRewriteW = Transform (WriterT [LetBinding] (R NormalizeMonad))
liftNormR :: RewriteMonad NormalizeMonad a
-> WriterT [LetBinding] (R NormalizeMonad) a
liftNormR = lift . R
makeANF :: NormRewrite
makeANF ctx (Lam b) = do
let (bndr,e) = unsafeUnbind b
e' <- makeANF (LamBody bndr:ctx) e
return $ Lam (bind bndr e')
makeANF _ (TyLam b) = return (TyLam b)
makeANF ctx e
= R $ do
(e',bndrs) <- runR $ runWriterT $ bottomupR collectANF ctx e
case bndrs of
[] -> return e
_ -> changed . Letrec $ bind (rec bndrs) e'
collectANF :: NormRewriteW
collectANF _ e@(App appf arg)
| (conVarPrim, _) <- collectArgs e
, isCon conVarPrim || isPrim conVarPrim || isVar conVarPrim
= do
untranslatable <- liftNormR $ isUntranslatable arg
localVar <- liftNormR $ isLocalVar arg
case (untranslatable,localVar || isConstant arg,arg) of
(False,False,_) -> do tcm <- Lens.use tcCache
(argId,argVar) <- liftNormR $ mkTmBinderFor tcm "repANF" arg
tell [(argId,embed arg)]
return (App appf argVar)
(True,False,Letrec b) -> do (binds,body) <- unbind b
tell (unrec binds)
return (App appf body)
_ -> return e
collectANF _ (Letrec b) = do
let (binds,body) = unsafeUnbind b
tell (unrec binds)
untranslatable <- liftNormR $ isUntranslatable body
localVar <- liftNormR $ isLocalVar body
if localVar || untranslatable
then return body
else do
tcm <- Lens.use tcCache
(argId,argVar) <- liftNormR $ mkTmBinderFor tcm "bodyVar" body
tell [(argId,embed body)]
return argVar
collectANF _ e@(Case _ _ [unsafeUnbind -> (DataPat dc _,_)])
| name2String (dcName $ unembed dc) == "CLaSH.Signal.Internal.:-" = return e
collectANF ctx (Case subj ty alts) = do
localVar <- liftNormR $ isLocalVar subj
(bndr,subj') <- if localVar || isConstant subj
then return ([],subj)
else do tcm <- Lens.use tcCache
(argId,argVar) <- liftNormR $ mkTmBinderFor tcm "subjLet" subj
return ([(argId,embed subj)],argVar)
(binds,alts') <- fmap (first concat . unzip) $ liftNormR $ mapM (doAlt subj') alts
tell (bndr ++ binds)
return (Case subj' ty alts')
where
doAlt :: Term -> Bind Pat Term -> RewriteMonad NormalizeMonad ([LetBinding],Bind Pat Term)
doAlt subj' = fmap (second (uncurry bind)) . doAlt' subj' . unsafeUnbind
doAlt' :: Term -> (Pat,Term) -> RewriteMonad NormalizeMonad ([LetBinding],(Pat,Term))
doAlt' subj' alt@(DataPat dc pxs@(unrebind -> ([],xs)),altExpr) = do
lv <- isLocalVar altExpr
patSels <- Monad.zipWithM (doPatBndr subj' (unembed dc)) xs [0..]
let usesXs (Var _ n) = any ((== n) . varName) xs
usesXs _ = False
if (lv && not (usesXs altExpr)) || isConstant altExpr
then return (patSels,alt)
else do tcm <- Lens.use tcCache
(altId,altVar) <- mkTmBinderFor tcm "altLet" altExpr
return ((altId,embed altExpr):patSels,(DataPat dc pxs,altVar))
doAlt' _ alt@(DataPat _ _, _) = return ([],alt)
doAlt' _ alt@(pat,altExpr) = do
lv <- isLocalVar altExpr
if lv || isConstant altExpr
then return ([],alt)
else do tcm <- Lens.use tcCache
(altId,altVar) <- mkTmBinderFor tcm "altLet" altExpr
return ([(altId,embed altExpr)],(pat,altVar))
doPatBndr :: Term -> DataCon -> Id -> Int -> RewriteMonad NormalizeMonad LetBinding
doPatBndr subj' dc pId i
= do tcm <- Lens.use tcCache
patExpr <- mkSelectorCase ($(curLoc) ++ "doPatBndr") tcm ctx subj' (dcTag dc) i
return (pId,embed patExpr)
collectANF _ e = return e
etaExpansionTL :: NormRewrite
etaExpansionTL ctx (Lam b) = do
(bndr,e) <- unbind b
e' <- etaExpansionTL (LamBody bndr:ctx) e
return $ Lam (bind bndr e')
etaExpansionTL ctx e
= R $ do
tcm <- Lens.use tcCache
isF <- isFun tcm e
if isF
then do
argTy <- ( return
. fst
. Maybe.fromMaybe (error $ $(curLoc) ++ "etaExpansion splitFunTy")
. splitFunTy tcm
<=< termType tcm
) e
(newIdB,newIdV) <- mkInternalVar "eta" argTy
e' <- runR $ etaExpansionTL (LamBody newIdB:ctx) (App e newIdV)
changed . Lam $ bind newIdB e'
else return e
recToLetRec :: NormRewrite
recToLetRec [] e = R $ do
fn <- liftR $ Lens.use curFun
bodyM <- fmap (HashMap.lookup fn) $ Lens.use bindings
tcm <- Lens.use tcCache
normalizedE <- splitNormalized tcm e
case (normalizedE,bodyM) of
(Right (args,bndrs,res), Just (bodyTy,_)) -> do
let appF = mkTmApps (Var bodyTy fn) (map idToVar args)
(toInline,others) = List.partition ((==) appF . unembed . snd) bndrs
resV = idToVar res
case (toInline,others) of
(_:_,_:_) -> do
let substsInline = map (\(id_,_) -> (varName id_,resV)) toInline
others' = map (second (embed . substTms substsInline . unembed)) others
changed $ mkLams (Letrec $ bind (rec others') resV) args
_ -> return e
_ -> return e
recToLetRec _ e = return e
inlineHO :: NormRewrite
inlineHO _ e@(App _ _)
| (Var _ f, args) <- collectArgs e
= R $ do
tcm <- Lens.use tcCache
hasPolyFunArgs <- or <$> mapM (either (isPolyFun tcm) (const (return False))) args
if hasPolyFunArgs
then do isInlined <- liftR $ alreadyInlined f
limit <- liftR $ Lens.use inlineLimit
if (Maybe.fromMaybe 0 isInlined) > limit
then do
cf <- liftR $ Lens.use curFun
lvl <- Lens.view dbgLevel
traceIf (lvl > DebugNone) ($(curLoc) ++ "InlineHO: " ++ show f ++ " already inlined " ++ show limit ++ " times in:" ++ show cf) (return e)
else do
bodyMaybe <- fmap (HashMap.lookup f) $ Lens.use bindings
case bodyMaybe of
Just (_, body) -> do
liftR $ addNewInline f
changed $ mkApps body args
_ -> return e
else return e
inlineHO _ e = return e
simpleCSE :: NormRewrite
simpleCSE _ e@(Letrec b) = R $ do
(binders,body) <- first unrec <$> unbind b
let (reducedBindings,body') = reduceBindersFix binders body
if length binders /= length reducedBindings
then changed (Letrec (bind (rec reducedBindings) body'))
else return e
simpleCSE _ e = return e
reduceBindersFix :: [LetBinding]
-> Term
-> ([LetBinding],Term)
reduceBindersFix binders body = if length binders /= length reduced
then reduceBindersFix reduced body'
else (binders,body)
where
(reduced,body') = reduceBinders [] body binders
reduceBinders :: [LetBinding]
-> Term
-> [LetBinding]
-> ([LetBinding],Term)
reduceBinders processed body [] = (processed,body)
reduceBinders processed body ((id_,expr):binders) = case List.find ((== expr) . snd) processed of
Just (id2,_) ->
let var = Var (unembed (varType id2)) (varName id2)
idName = varName id_
processed' = map (second (Embed . (substTm idName var) . unembed)) processed
binders' = map (second (Embed . (substTm idName var) . unembed)) binders
body' = substTm idName var body
in reduceBinders processed' body' binders'
Nothing -> reduceBinders ((id_,expr):processed) body binders
reduceConst :: NormRewrite
reduceConst _ e@(App _ _)
| isConstant e
, (conPrim, _) <- collectArgs e
, isPrim conPrim
= R $ do
tcm <- Lens.use tcCache
reduceConstant <- Lens.use evaluator
case reduceConstant tcm e of
e'@(Data _) -> changed e'
e'@(Literal _) -> changed e'
_ -> return e
reduceConst _ e = return e