X-Git-Url: https://git.stderr.nl/gitweb?a=blobdiff_plain;f=c%CE%BBash%2FCLasH%2FNormalize.hs;h=17143ffb6d857d555f2f52a30d9d99ab7eb4752b;hb=f3951a1376fc7d7f8addbe9e9fed071320502100;hp=e69db2c4421c0f018bfab8a1aac78fc0a4c91ac3;hpb=4b87be0b9d499155084a6240b016afd57b4b30cd;p=matthijs%2Fmaster-project%2Fc%CE%BBash.git diff --git "a/c\316\273ash/CLasH/Normalize.hs" "b/c\316\273ash/CLasH/Normalize.hs" index e69db2c..17143ff 100644 --- "a/c\316\273ash/CLasH/Normalize.hs" +++ "b/c\316\273ash/CLasH/Normalize.hs" @@ -4,39 +4,35 @@ -- top level function "normalize", and defines the actual transformation passes that -- are performed. -- -module CLasH.Normalize (normalizeModule) where +module CLasH.Normalize (getNormalized, normalizeExpr, splitNormalized) where -- Standard modules import Debug.Trace import qualified Maybe +import qualified List import qualified "transformers" Control.Monad.Trans as Trans import qualified Control.Monad as Monad import qualified Control.Monad.Trans.Writer as Writer -import qualified Data.Map as Map import qualified Data.Monoid as Monoid -import Data.Accessor -- GHC API import CoreSyn -import qualified UniqSupply import qualified CoreUtils import qualified Type -import qualified TcType import qualified Id import qualified Var import qualified VarSet -import qualified NameSet import qualified CoreFVs -import qualified CoreUtils import qualified MkCore -import qualified HscTypes import Outputable ( showSDoc, ppr, nest ) -- Local imports import CLasH.Normalize.NormalizeTypes +import CLasH.Translator.TranslatorTypes import CLasH.Normalize.NormalizeTools -import CLasH.VHDL.VHDLTypes +import qualified CLasH.Utils as Utils import CLasH.Utils.Core.CoreTools +import CLasH.Utils.Core.BinderTools import CLasH.Utils.Pretty -------------------------------- @@ -49,7 +45,7 @@ import CLasH.Utils.Pretty eta, etatop :: Transform eta expr | is_fun expr && not (is_lam expr) = do let arg_ty = (fst . Type.splitFunTy . CoreUtils.exprType) expr - id <- mkInternalVar "param" arg_ty + id <- Trans.lift $ mkInternalVar "param" arg_ty change (Lam id (App expr (Var id))) -- Leave all other expressions unchanged eta e = return e @@ -59,8 +55,10 @@ etatop = notappargs ("eta", eta) -- β-reduction -------------------------------- beta, betatop :: Transform --- Substitute arg for x in expr -beta (App (Lam x expr) arg) = change $ substitute [(x, arg)] expr +-- Substitute arg for x in expr. For value lambda's, also clone before +-- substitution. +beta (App (Lam x expr) arg) | CoreSyn.isTyVar x = setChanged >> substitute x arg expr + | otherwise = setChanged >> substitute_clone x arg expr -- Propagate the application into the let beta (App (Let binds expr) arg) = change $ Let binds (App expr arg) -- Propagate the application into each of the alternatives @@ -88,31 +86,101 @@ castprop expr = return expr castproptop = everywhere ("castprop", castprop) -------------------------------- --- let recursification +-- Cast simplification. Mostly useful for state packing and unpacking, but +-- perhaps for others as well. +-------------------------------- +castsimpl, castsimpltop :: Transform +castsimpl expr@(Cast val ty) = do + -- Don't extract values that are already simpl + local_var <- Trans.lift $ is_local_var val + -- Don't extract values that are not representable, to prevent loops with + -- inlinenonrep + repr <- isRepr val + if (not local_var) && repr + then do + -- Generate a binder for the expression + id <- Trans.lift $ mkBinderFor val "castval" + -- Extract the expression + change $ Let (NonRec id val) (Cast (Var id) ty) + else + return expr +-- Leave all other expressions unchanged +castsimpl expr = return expr +-- Perform this transform everywhere +castsimpltop = everywhere ("castsimpl", castsimpl) + + -------------------------------- -letrec, letrectop :: Transform -letrec (Let (NonRec b expr) res) = change $ Let (Rec [(b, expr)]) res +-- Lambda simplication +-------------------------------- +-- Ensure that a lambda always evaluates to a let expressions or a simple +-- variable reference. +lambdasimpl, lambdasimpltop :: Transform +-- Don't simplify a lambda that evaluates to let, since this is already +-- normal form (and would cause infinite loops). +lambdasimpl expr@(Lam _ (Let _ _)) = return expr +-- Put the of a lambda in its own binding, but not when the expression is +-- already a local variable, or not representable (to prevent loops with +-- inlinenonrep). +lambdasimpl expr@(Lam bndr res) = do + repr <- isRepr res + local_var <- Trans.lift $ is_local_var res + if not local_var && repr + then do + id <- Trans.lift $ mkBinderFor res "res" + change $ Lam bndr (Let (NonRec id res) (Var id)) + else + -- If the result is already a local var or not representable, don't + -- extract it. + return expr + -- Leave all other expressions unchanged -letrec expr = return expr +lambdasimpl expr = return expr -- Perform this transform everywhere -letrectop = everywhere ("letrec", letrec) +lambdasimpltop = everywhere ("lambdasimpl", lambdasimpl) + +-------------------------------- +-- let derecursification +-------------------------------- +letderec, letderectop :: Transform +letderec expr@(Let (Rec binds) res) = case liftable of + -- Nothing is liftable, just return + [] -> return expr + -- Something can be lifted, generate a new let expression + _ -> change $ mkNonRecLets liftable (Let (Rec nonliftable) res) + where + -- Make a list of all the binders bound in this recursive let + bndrs = map fst binds + -- See which bindings are liftable + (liftable, nonliftable) = List.partition canlift binds + -- Any expression that does not use any of the binders in this recursive let + -- can be lifted into a nonrec let. It can't use its own binder either, + -- since that would mean the binding is self-recursive and should be in a + -- single bind recursive let. + canlift (bndr, e) = not $ expr_uses_binders bndrs e +-- Leave all other expressions unchanged +letderec expr = return expr +-- Perform this transform everywhere +letderectop = everywhere ("letderec", letderec) -------------------------------- -- let simplification -------------------------------- letsimpl, letsimpltop :: Transform +-- Don't simplify a let that evaluates to another let, since this is already +-- normal form (and would cause infinite loops with letflat below). +letsimpl expr@(Let _ (Let _ _)) = return expr -- Put the "in ..." value of a let in its own binding, but not when the -- expression is already a local variable, or not representable (to prevent loops with inlinenonrep). -letsimpl expr@(Let (Rec binds) res) = do +letsimpl expr@(Let binds res) = do repr <- isRepr res local_var <- Trans.lift $ is_local_var res if not local_var && repr then do -- If the result is not a local var already (to prevent loops with -- ourselves), extract it. - id <- mkInternalVar "foo" (CoreUtils.exprType res) - let bind = (id, res) - change $ Let (Rec (bind:binds)) (Var id) + id <- Trans.lift $ mkBinderFor res "foo" + change $ Let binds (Let (NonRec id res) (Var id)) else -- If the result is already a local var, don't extract it. return expr @@ -125,13 +193,18 @@ letsimpltop = everywhere ("letsimpl", letsimpl) -------------------------------- -- let flattening -------------------------------- +-- Takes a let that binds another let, and turns that into two nested lets. +-- e.g., from: +-- let b = (let b' = expr' in res') in res +-- to: +-- let b' = expr' in (let b = res' in res) letflat, letflattop :: Transform +-- Turn a nonrec let that binds a let into two nested lets. +letflat (Let (NonRec b (Let binds res')) res) = + change $ Let binds (Let (NonRec b res') res) letflat (Let (Rec binds) expr) = do - -- Turn each binding into a list of bindings (possibly containing just one - -- element, of course) - bindss <- Monad.mapM flatbind binds - -- Concat all the bindings - let binds' = concat bindss + -- Flatten each binding. + binds' <- Utils.concatM $ Monad.mapM flatbind binds -- Return the new let. We don't use change here, since possibly nothing has -- changed. If anything has changed, flatbind has already flagged that -- change. @@ -141,37 +214,158 @@ letflat (Let (Rec binds) expr) = do -- into a list with just that binding flatbind :: (CoreBndr, CoreExpr) -> TransformMonad [(CoreBndr, CoreExpr)] flatbind (b, Let (Rec binds) expr) = change ((b, expr):binds) + flatbind (b, Let (NonRec b' expr') expr) = change [(b, expr), (b', expr')] flatbind (b, expr) = return [(b, expr)] -- Leave all other expressions unchanged letflat expr = return expr -- Perform this transform everywhere letflattop = everywhere ("letflat", letflat) +-------------------------------- +-- empty let removal +-------------------------------- +-- Remove empty (recursive) lets +letremove, letremovetop :: Transform +letremove (Let (Rec []) res) = change res +-- Leave all other expressions unchanged +letremove expr = return expr +-- Perform this transform everywhere +letremovetop = everywhere ("letremove", letremove) + -------------------------------- -- Simple let binding removal -------------------------------- -- Remove a = b bindings from let expressions everywhere -letremovetop :: Transform -letremovetop = everywhere ("letremove", inlinebind (\(b, e) -> Trans.lift $ is_local_var e)) +letremovesimpletop :: Transform +letremovesimpletop = everywhere ("letremovesimple", inlinebind (\(b, e) -> Trans.lift $ is_local_var e)) + +-------------------------------- +-- Unused let binding removal +-------------------------------- +letremoveunused, letremoveunusedtop :: Transform +letremoveunused expr@(Let (NonRec b bound) res) = do + let used = expr_uses_binders [b] res + if used + then return expr + else change res +letremoveunused expr@(Let (Rec binds) res) = do + -- Filter out all unused binds. + let binds' = filter dobind binds + -- Only set the changed flag if binds got removed + changeif (length binds' /= length binds) (Let (Rec binds') res) + where + bound_exprs = map snd binds + -- For each bind check if the bind is used by res or any of the bound + -- expressions + dobind (bndr, _) = any (expr_uses_binders [bndr]) (res:bound_exprs) +-- Leave all other expressions unchanged +letremoveunused expr = return expr +letremoveunusedtop = everywhere ("letremoveunused", letremoveunused) + +{- +-------------------------------- +-- Identical let binding merging +-------------------------------- +-- Merge two bindings in a let if they are identical +-- TODO: We would very much like to use GHC's CSE module for this, but that +-- doesn't track if something changed or not, so we can't use it properly. +letmerge, letmergetop :: Transform +letmerge expr@(Let _ _) = do + let (binds, res) = flattenLets expr + binds' <- domerge binds + return $ mkNonRecLets binds' res + where + domerge :: [(CoreBndr, CoreExpr)] -> TransformMonad [(CoreBndr, CoreExpr)] + domerge [] = return [] + domerge (e:es) = do + es' <- mapM (mergebinds e) es + es'' <- domerge es' + return (e:es'') + + -- Uses the second bind to simplify the second bind, if applicable. + mergebinds :: (CoreBndr, CoreExpr) -> (CoreBndr, CoreExpr) -> TransformMonad (CoreBndr, CoreExpr) + mergebinds (b1, e1) (b2, e2) + -- Identical expressions? Replace the second binding with a reference to + -- the first binder. + | CoreUtils.cheapEqExpr e1 e2 = change $ (b2, Var b1) + -- Different expressions? Don't change + | otherwise = return (b2, e2) +-- Leave all other expressions unchanged +letmerge expr = return expr +letmergetop = everywhere ("letmerge", letmerge) +-} -------------------------------- --- Function inlining +-- Non-representable binding inlining -------------------------------- --- Remove a = B bindings, with B :: a -> b, or B :: forall x . T, from let --- expressions everywhere. This means that any value that still needs to be --- applied to something else (polymorphic values need to be applied to a --- Type) will be inlined, and will eventually be applied to all their --- arguments. +-- Remove a = B bindings, with B of a non-representable type, from let +-- expressions everywhere. This means that any value that we can't generate a +-- signal for, will be inlined and hopefully turned into something we can +-- represent. -- -- This is a tricky function, which is prone to create loops in the -- transformations. To fix this, we make sure that no transformation will --- create a new let binding with a function type. These other transformations --- will just not work on those function-typed values at first, but the other --- transformations (in particular β-reduction) should make sure that the type --- of those values eventually becomes primitive. +-- create a new let binding with a non-representable type. These other +-- transformations will just not work on those function-typed values at first, +-- but the other transformations (in particular β-reduction) should make sure +-- that the type of those values eventually becomes representable. inlinenonreptop :: Transform inlinenonreptop = everywhere ("inlinenonrep", inlinebind ((Monad.liftM not) . isRepr . snd)) +-------------------------------- +-- Top level function inlining +-------------------------------- +-- This transformation inlines top level bindings that have been generated by +-- the compiler and are really simple. Really simple currently means that the +-- normalized form only contains a single binding, which catches most of the +-- cases where a top level function is created that simply calls a type class +-- method with a type and dictionary argument, e.g. +-- fromInteger = GHC.Num.fromInteger (SizedWord D8) $dNum +-- which is later called using simply +-- fromInteger (smallInteger 10) +-- By inlining such calls to simple, compiler generated functions, we prevent +-- huge amounts of trivial components in the VHDL output, which the user never +-- wanted. We never inline user-defined functions, since we want to preserve +-- all structure defined by the user. Currently this includes all functions +-- that were created by funextract, since we would get loops otherwise. +-- +-- Note that "defined by the compiler" isn't completely watertight, since GHC +-- doesn't seem to set all those names as "system names", we apply some +-- guessing here. +inlinetoplevel, inlinetopleveltop :: Transform +-- Any system name is candidate for inlining. Never inline user-defined +-- functions, to preserve structure. +inlinetoplevel expr@(Var f) | not $ isUserDefined f = do + norm <- isNormalizeable f + -- See if this is a top level binding for which we have a body + body_maybe <- Trans.lift $ getGlobalBind f + if norm && Maybe.isJust body_maybe + then do + -- Get the normalized version + norm <- Trans.lift $ getNormalized f + if needsInline norm + then do + -- Regenerate all uniques in the to-be-inlined expression + norm_uniqued <- Trans.lift $ genUniques norm + change norm_uniqued + else + return expr + else + -- No body or not normalizeable. + return expr +-- Leave all other expressions unchanged +inlinetoplevel expr = return expr +inlinetopleveltop = everywhere ("inlinetoplevel", inlinetoplevel) + +needsInline :: CoreExpr -> Bool +needsInline expr = case splitNormalized expr of + -- Inline any function that only has a single definition, it is probably + -- simple enough. This might inline some stuff that it shouldn't though it + -- will never inline user-defined functions (inlinetoplevel only tries + -- system names) and inlining should never break things. + (args, [bind], res) -> True + _ -> False + -------------------------------- -- Scrutinee simplification -------------------------------- @@ -179,12 +373,17 @@ scrutsimpl,scrutsimpltop :: Transform -- Don't touch scrutinees that are already simple scrutsimpl expr@(Case (Var _) _ _ _) = return expr -- Replace all other cases with a let that binds the scrutinee and a new --- simple scrutinee, but not when the scrutinee is applicable (to prevent --- loops with inlinefun, though I don't think a scrutinee can be --- applicable...) -scrutsimpl (Case scrut b ty alts) | not $ is_applicable scrut = do - id <- mkInternalVar "scrut" (CoreUtils.exprType scrut) - change $ Let (Rec [(id, scrut)]) (Case (Var id) b ty alts) +-- simple scrutinee, but only when the scrutinee is representable (to prevent +-- loops with inlinenonrep, though I don't think a non-representable scrutinee +-- will be supported anyway...) +scrutsimpl expr@(Case scrut b ty alts) = do + repr <- isRepr scrut + if repr + then do + id <- Trans.lift $ mkBinderFor scrut "scrut" + change $ Let (NonRec id scrut) (Case (Var id) b ty alts) + else + return expr -- Leave all other expressions unchanged scrutsimpl expr = return expr -- Perform this transform everywhere @@ -193,17 +392,27 @@ scrutsimpltop = everywhere ("scrutsimpl", scrutsimpl) -------------------------------- -- Case binder wildening -------------------------------- -casewild, casewildtop :: Transform -casewild expr@(Case scrut b ty alts) = do +casesimpl, casesimpltop :: Transform +-- This is already a selector case (or, if x does not appear in bndrs, a very +-- simple case statement that will be removed by caseremove below). Just leave +-- it be. +casesimpl expr@(Case scrut b ty [(con, bndrs, Var x)]) = return expr +-- Make sure that all case alternatives have only wild binders and simple +-- expressions. +-- This is done by creating a new let binding for each non-wild binder, which +-- is bound to a new simple selector case statement and for each complex +-- expression. We do this only for representable types, to prevent loops with +-- inlinenonrep. +casesimpl expr@(Case scrut b ty alts) = do (bindingss, alts') <- (Monad.liftM unzip) $ mapM doalt alts let bindings = concat bindingss -- Replace the case with a let with bindings and a case - let newlet = (Let (Rec bindings) (Case scrut b ty alts')) + let newlet = mkNonRecLets bindings (Case scrut b ty alts') -- If there are no non-wild binders, or this case is already a simple -- selector (i.e., a single alt with exactly one binding), already a simple -- selector altan no bindings (i.e., no wild binders in the original case), -- don't change anything, otherwise, replace the case. - if null bindings || length alts == 1 && length bindings == 1 then return expr else change newlet + if null bindings then return expr else change newlet where -- Generate a single wild binder, since they are all the same wild = MkCore.mkWildBinder @@ -211,77 +420,71 @@ casewild expr@(Case scrut b ty alts) = do -- sideeffect. doalt :: CoreAlt -> TransformMonad ([(CoreBndr, CoreExpr)], CoreAlt) doalt (con, bndrs, expr) = do - bindings_maybe <- Monad.zipWithM mkextracts bndrs [0..] - let bindings = Maybe.catMaybes bindings_maybe - -- We replace the binders with wild binders only. We can leave expr - -- unchanged, since the new bindings bind the same vars as the original - -- did. - let newalt = (con, wildbndrs, expr) + -- Make each binder wild, if possible + bndrs_res <- Monad.zipWithM dobndr bndrs [0..] + let (newbndrs, bindings_maybe) = unzip bndrs_res + -- Extract a complex expression, if possible. For this we check if any of + -- the new list of bndrs are used by expr. We can't use free_vars here, + -- since that looks at the old bndrs. + let uses_bndrs = not $ VarSet.isEmptyVarSet $ CoreFVs.exprSomeFreeVars (`elem` newbndrs) expr + (exprbinding_maybe, expr') <- doexpr expr uses_bndrs + -- Create a new alternative + let newalt = (con, newbndrs, expr') + let bindings = Maybe.catMaybes (bindings_maybe ++ [exprbinding_maybe]) return (bindings, newalt) where - -- Make all binders wild + -- Make wild alternatives for each binder wildbndrs = map (\bndr -> MkCore.mkWildBinder (Id.idType bndr)) bndrs -- A set of all the binders that are used by the expression free_vars = CoreFVs.exprSomeFreeVars (`elem` bndrs) expr - -- Creates a case statement to retrieve the ith element from the scrutinee - -- and binds that to b. - mkextracts :: CoreBndr -> Int -> TransformMonad (Maybe (CoreBndr, CoreExpr)) - mkextracts b i = - if not (VarSet.elemVarSet b free_vars) || Type.isFunTy (Id.idType b) - -- Don't create extra bindings for binders that are already wild - -- (e.g. not in the free variables of expr, so unused), or for - -- binders that bind function types (to prevent loops with - -- inlinefun). - then return Nothing - else do + -- Look at the ith binder in the case alternative. Return a new binder + -- for it (either the same one, or a wild one) and optionally a let + -- binding containing a case expression. + dobndr :: CoreBndr -> Int -> TransformMonad (CoreBndr, Maybe (CoreBndr, CoreExpr)) + dobndr b i = do + repr <- isRepr b + -- Is b wild (e.g., not a free var of expr. Since b is only in scope + -- in expr, this means that b is unused if expr does not use it.) + let wild = not (VarSet.elemVarSet b free_vars) + -- Create a new binding for any representable binder that is not + -- already wild and is representable (to prevent loops with + -- inlinenonrep). + if (not wild) && repr + then do -- Create on new binder that will actually capture a value in this - -- case statement, and return it + -- case statement, and return it. let bty = (Id.idType b) - id <- mkInternalVar "sel" bty + id <- Trans.lift $ mkInternalVar "sel" bty let binders = take i wildbndrs ++ [id] ++ drop (i+1) wildbndrs - return $ Just (b, Case scrut b bty [(con, binders, Var id)]) + let caseexpr = Case scrut b bty [(con, binders, Var id)] + return (wildbndrs!!i, Just (b, caseexpr)) + else + -- Just leave the original binder in place, and don't generate an + -- extra selector case. + return (b, Nothing) + -- Process the expression of a case alternative. Accepts an expression + -- and whether this expression uses any of the binders in the + -- alternative. Returns an optional new binding and a new expression. + doexpr :: CoreExpr -> Bool -> TransformMonad (Maybe (CoreBndr, CoreExpr), CoreExpr) + doexpr expr uses_bndrs = do + local_var <- Trans.lift $ is_local_var expr + repr <- isRepr expr + -- Extract any expressions that do not use any binders from this + -- alternative, is not a local var already and is representable (to + -- prevent loops with inlinenonrep). + if (not uses_bndrs) && (not local_var) && repr + then do + id <- Trans.lift $ mkBinderFor expr "caseval" + -- We don't flag a change here, since casevalsimpl will do that above + -- based on Just we return here. + return (Just (id, expr), Var id) + else + -- Don't simplify anything else + return (Nothing, expr) -- Leave all other expressions unchanged -casewild expr = return expr +casesimpl expr = return expr -- Perform this transform everywhere -casewildtop = everywhere ("casewild", casewild) - --------------------------------- --- Case value simplification --------------------------------- -casevalsimpl, casevalsimpltop :: Transform -casevalsimpl expr@(Case scrut b ty alts) = do - -- Try to simplify each alternative, resulting in an optional binding and a - -- new alternative. - (bindings_maybe, alts') <- (Monad.liftM unzip) $ mapM doalt alts - let bindings = Maybe.catMaybes bindings_maybe - -- Create a new let around the case, that binds of the cases values. - let newlet = Let (Rec bindings) (Case scrut b ty alts') - -- If there were no values that needed and allowed simplification, don't - -- change the case. - if null bindings then return expr else change newlet - where - doalt :: CoreAlt -> TransformMonad (Maybe (CoreBndr, CoreExpr), CoreAlt) - -- Don't simplify values that are already simple - doalt alt@(con, bndrs, Var _) = return (Nothing, alt) - -- Simplify each alt by creating a new id, binding the case value to it and - -- replacing the case value with that id. Only do this when the case value - -- does not use any of the binders bound by this alternative, for that would - -- cause those binders to become unbound when moving the value outside of - -- the case statement. Also, don't create a binding for applicable - -- expressions, to prevent loops with inlinefun. - doalt (con, bndrs, expr) | (not usesvars) && (not $ is_applicable expr) = do - id <- mkInternalVar "caseval" (CoreUtils.exprType expr) - -- We don't flag a change here, since casevalsimpl will do that above - -- based on Just we return here. - return $ (Just (id, expr), (con, bndrs, Var id)) - -- Find if any of the binders are used by expr - where usesvars = (not . VarSet.isEmptyVarSet . (CoreFVs.exprSomeFreeVars (`elem` bndrs))) expr - -- Don't simplify anything else - doalt alt = return (Nothing, alt) --- Leave all other expressions unchanged -casevalsimpl expr = return expr --- Perform this transform everywhere -casevalsimpltop = everywhere ("casevalsimpl", casevalsimpl) +casesimpltop = everywhere ("casesimpl", casesimpl) -------------------------------- -- Case removal @@ -311,8 +514,8 @@ appsimpl expr@(App f arg) = do local_var <- Trans.lift $ is_local_var arg if repr && not local_var then do -- Extract representable arguments - id <- mkInternalVar "arg" (CoreUtils.exprType arg) - change $ Let (Rec [(id, arg)]) (App f (Var id)) + id <- Trans.lift $ mkBinderFor arg "arg" + change $ Let (NonRec id arg) (App f (Var id)) else -- Leave non-representable arguments unchanged return expr -- Leave all other expressions unchanged @@ -347,7 +550,7 @@ argprop expr@(App _ _) | is_var fexpr = do -- the old body applied to some arguments. let newbody = MkCore.mkCoreLams newparams (MkCore.mkCoreApps body oldargs) -- Create a new function with the same name but a new body - newf <- mkFunction f newbody + newf <- Trans.lift $ mkFunction f newbody -- Replace the original application with one of the new function to the -- new arguments. change $ MkCore.mkCoreApps (Var newf) newargs @@ -372,7 +575,7 @@ argprop expr@(App _ _) | is_var fexpr = do doarg arg = do repr <- isRepr arg bndrs <- Trans.lift getGlobalBinders - let interesting var = Var.isLocalVar var && (not $ var `elem` bndrs) + let interesting var = Var.isLocalVar var && (var `notElem` bndrs) if not repr && not (is_var arg && interesting (exprToVar arg)) && not (has_free_tyvars arg) then do -- Propagate all complex arguments that are not representable, but not @@ -393,7 +596,7 @@ argprop expr@(App _ _) | is_var fexpr = do -- Representable types will not be propagated, and arguments with free -- type variables will be propagated later. -- TODO: preserve original naming? - id <- mkBinderFor arg "param" + id <- Trans.lift $ mkBinderFor arg "param" -- Just pass the original argument to the new function, which binds it -- to a new id and just pass that new id to the old function body. return ([arg], [id], mkReferenceTo id) @@ -408,7 +611,7 @@ argproptop = everywhere ("argprop", argprop) -- This transform takes any function-typed argument that cannot be propagated -- (because the function that is applied to it is a builtin function), and -- puts it in a brand new top level binder. This allows us to for example --- apply map to a lambda expression This will not conflict with inlinefun, +-- apply map to a lambda expression This will not conflict with inlinenonrep, -- since that only inlines local let bindings, not top level bindings. funextract, funextracttop :: Transform funextract expr@(App _ _) | is_var fexpr = do @@ -440,7 +643,7 @@ funextract expr@(App _ _) | is_var fexpr = do -- by the argument expression. let free_vars = VarSet.varSetElems $ CoreFVs.exprFreeVars arg let body = MkCore.mkCoreLams free_vars arg - id <- mkBinderFor body "fun" + id <- Trans.lift $ mkBinderFor body "fun" Trans.lift $ addGlobalBind id body -- Replace the argument with a reference to the new function, applied to -- all vars it uses. @@ -453,6 +656,25 @@ funextract expr = return expr -- Perform this transform everywhere funextracttop = everywhere ("funextract", funextract) +-------------------------------- +-- Ensure that a function that just returns another function (or rather, +-- another top-level binder) is still properly normalized. This is a temporary +-- solution, we should probably integrate this pass with lambdasimpl and +-- letsimpl instead. +-------------------------------- +simplrestop expr@(Lam _ _) = return expr +simplrestop expr@(Let _ _) = return expr +simplrestop expr = do + local_var <- Trans.lift $ is_local_var expr + -- Don't extract values that are not representable, to prevent loops with + -- inlinenonrep + repr <- isRepr expr + if local_var || not repr + then + return expr + else do + id <- Trans.lift $ mkBinderFor expr "res" + change $ Let (NonRec id expr) (Var id) -------------------------------- -- End of transformations -------------------------------- @@ -461,80 +683,57 @@ funextracttop = everywhere ("funextract", funextract) -- What transforms to run? -transforms = [argproptop, funextracttop, etatop, betatop, castproptop, letremovetop, letrectop, letsimpltop, letflattop, casewildtop, scrutsimpltop, casevalsimpltop, caseremovetop, inlinenonreptop, appsimpltop] - --- Turns the given bind into VHDL -normalizeModule :: - HscTypes.HscEnv - -> UniqSupply.UniqSupply -- ^ A UniqSupply we can use - -> [(CoreBndr, CoreExpr)] -- ^ All bindings we know (i.e., in the current module) - -> [CoreExpr] - -> [CoreBndr] -- ^ The bindings to generate VHDL for (i.e., the top level bindings) - -> [Bool] -- ^ For each of the bindings to generate VHDL for, if it is stateful - -> ([(CoreBndr, CoreExpr)], [(CoreBndr, CoreExpr)], TypeState) -- ^ The resulting VHDL - -normalizeModule env uniqsupply bindings testexprs generate_for statefuls = runTransformSession env uniqsupply $ do - testbinds <- mapM (\x -> do { v <- mkBinderFor' x "test" ; return (v,x) } ) testexprs - let testbinders = (map fst testbinds) - -- Put all the bindings in this module in the tsBindings map - putA tsBindings (Map.fromList (bindings ++ testbinds)) - -- (Recursively) normalize each of the requested bindings - mapM normalizeBind (generate_for ++ testbinders) - -- Get all initial bindings and the ones we produced - bindings_map <- getA tsBindings - let bindings = Map.assocs bindings_map - normalized_binders' <- getA tsNormalized - let normalized_binders = VarSet.delVarSetList normalized_binders' testbinders - let ret_testbinds = zip testbinders (Maybe.catMaybes $ map (\x -> lookup x bindings) testbinders) - let ret_binds = filter ((`VarSet.elemVarSet` normalized_binders) . fst) bindings - typestate <- getA tsType - -- But return only the normalized bindings - return $ (ret_binds, ret_testbinds, typestate) - -normalizeBind :: CoreBndr -> TransformSession () -normalizeBind bndr = - -- Don't normalize global variables, these should be either builtin - -- functions or data constructors. - Monad.when (Var.isLocalId bndr) $ do - -- Skip binders that have a polymorphic type, since it's impossible to - -- create polymorphic hardware. - if is_poly (Var bndr) - then - -- This should really only happen at the top level... TODO: Give - -- a different error if this happens down in the recursion. - error $ "\nNormalize.normalizeBind: Function " ++ show bndr ++ " is polymorphic, can't normalize" - else do - normalized_funcs <- getA tsNormalized - -- See if this function was normalized already - if VarSet.elemVarSet bndr normalized_funcs - then - -- Yup, don't do it again - return () - else do - -- Nope, note that it has been and do it. - modA tsNormalized (flip VarSet.extendVarSet bndr) - expr_maybe <- getGlobalBind bndr - case expr_maybe of - Just expr -> do - -- Introduce an empty Let at the top level, so there will always be - -- a let in the expression (none of the transformations will remove - -- the last let). - let expr' = Let (Rec []) expr - -- Normalize this expression - trace ("Transforming " ++ (show bndr) ++ "\nBefore:\n\n" ++ showSDoc ( ppr expr' ) ++ "\n") $ return () - expr' <- dotransforms transforms expr' - trace ("\nAfter:\n\n" ++ showSDoc ( ppr expr')) $ return () - -- And store the normalized version in the session - modA tsBindings (Map.insert bndr expr') - -- Find all vars used with a function type. All of these should be global - -- binders (i.e., functions used), since any local binders with a function - -- type should have been inlined already. - bndrs <- getGlobalBinders - let used_funcs_set = CoreFVs.exprSomeFreeVars (\v -> not (Id.isDictId v) && v `elem` bndrs) expr' - let used_funcs = VarSet.varSetElems used_funcs_set - -- Process each of the used functions recursively - mapM normalizeBind used_funcs - return () - -- We don't have a value for this binder. This really shouldn't - -- happen for local id's... - Nothing -> error $ "\nNormalize.normalizeBind: No value found for binder " ++ pprString bndr ++ "? This should not happen!" +transforms = [inlinetopleveltop, argproptop, funextracttop, etatop, betatop, castproptop, letremovesimpletop, letderectop, letremovetop, letsimpltop, letflattop, scrutsimpltop, casesimpltop, caseremovetop, inlinenonreptop, appsimpltop, letremoveunusedtop, castsimpltop, lambdasimpltop, simplrestop] + +-- | Returns the normalized version of the given function. +getNormalized :: + CoreBndr -- ^ The function to get + -> TranslatorSession CoreExpr -- The normalized function body + +getNormalized bndr = Utils.makeCached bndr tsNormalized $ + if is_poly (Var bndr) + then + -- This should really only happen at the top level... TODO: Give + -- a different error if this happens down in the recursion. + error $ "\nNormalize.normalizeBind: Function " ++ show bndr ++ " is polymorphic, can't normalize" + else do + expr <- getBinding bndr + normalizeExpr (show bndr) expr + +-- | Normalize an expression +normalizeExpr :: + String -- ^ What are we normalizing? For debug output only. + -> CoreSyn.CoreExpr -- ^ The expression to normalize + -> TranslatorSession CoreSyn.CoreExpr -- ^ The normalized expression + +normalizeExpr what expr = do + expr_uniqued <- genUniques expr + -- Normalize this expression + trace (what ++ " before normalization:\n\n" ++ showSDoc ( ppr expr_uniqued ) ++ "\n") $ return () + expr' <- dotransforms transforms expr_uniqued + trace ("\n" ++ what ++ " after normalization:\n\n" ++ showSDoc ( ppr expr')) $ return () + return expr' + +-- | Get the value that is bound to the given binder at top level. Fails when +-- there is no such binding. +getBinding :: + CoreBndr -- ^ The binder to get the expression for + -> TranslatorSession CoreExpr -- ^ The value bound to the binder + +getBinding bndr = Utils.makeCached bndr tsBindings $ + -- If the binding isn't in the "cache" (bindings map), then we can't create + -- it out of thin air, so return an error. + error $ "Normalize.getBinding: Unknown function requested: " ++ show bndr + +-- | Split a normalized expression into the argument binders, top level +-- bindings and the result binder. +splitNormalized :: + CoreExpr -- ^ The normalized expression + -> ([CoreBndr], [Binding], CoreBndr) +splitNormalized expr = (args, binds, res) + where + (args, letexpr) = CoreSyn.collectBinders expr + (binds, resexpr) = flattenLets letexpr + res = case resexpr of + (Var x) -> x + _ -> error $ "Normalize.splitNormalized: Not in normal form: " ++ pprString expr ++ "\n"