X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Fspecialise%2FSpecialise.lhs;h=006e06d15e99605149e8463bec211c4137f20b67;hb=e6834cad29914f123edb32c20d42b16e3308e667;hp=081393a6ac61c7dd1981d95ee92cdf020eaa1566;hpb=18976e614fd90a8d81ced2c3e9cd8e38d72a1f40;p=ghc-hetmet.git diff --git a/ghc/compiler/specialise/Specialise.lhs b/ghc/compiler/specialise/Specialise.lhs index 081393a..006e06d 100644 --- a/ghc/compiler/specialise/Specialise.lhs +++ b/ghc/compiler/specialise/Specialise.lhs @@ -8,41 +8,42 @@ module Specialise ( specProgram ) where #include "HsVersions.h" -import CmdLineOpts ( opt_D_verbose_core2core, opt_D_dump_spec ) -import Id ( Id, idName, idType, mkTemplateLocals, mkUserLocal, - getIdSpecialisation, setIdSpecialisation, - isSpecPragmaId, +import CmdLineOpts ( DynFlags, DynFlag(..) ) +import Id ( Id, idName, idType, mkUserLocal ) +import TcType ( Type, mkTyVarTy, tcSplitSigmaTy, + tyVarsOfTypes, tyVarsOfTheta, isClassPred, + mkForAllTys, tcCmpType ) -import VarSet -import VarEnv - -import Type ( Type, TyVarSubst, mkTyVarTy, splitSigmaTy, substTy, - fullSubstTy, tyVarsOfType, tyVarsOfTypes, - mkForAllTys, boxedTypeKind - ) -import Var ( TyVar, mkSysTyVar, setVarUnique ) +import Subst ( Subst, mkSubst, substTy, mkSubst, extendSubstList, mkInScopeSet, + simplBndr, simplBndrs, + substAndCloneId, substAndCloneIds, substAndCloneRecIds, + lookupIdSubst, substInScope + ) +import Var ( zapSpecPragmaId ) import VarSet import VarEnv import CoreSyn -import CoreUtils ( IdSubst, SubstCoreExpr(..), exprFreeVars, - substExpr, substId, substIds, coreExprType - ) -import CoreLint ( beginPass, endPass ) -import PprCore () -- Instances -import SpecEnv ( addToSpecEnv ) +import CoreUtils ( applyTypeToArgs ) +import CoreFVs ( exprFreeVars, exprsFreeVars ) +import CoreTidy ( pprTidyIdRules ) +import CoreLint ( showPass, endPass ) +import Rules ( addIdSpecialisations, lookupRule ) import UniqSupply ( UniqSupply, - UniqSM, initUs, thenUs, thenUs_, returnUs, getUniqueUs, - getUs, setUs, uniqFromSupply, splitUniqSupply, mapUs + UniqSM, initUs_, thenUs, returnUs, getUniqueUs, + getUs, mapUs ) import Name ( nameOccName, mkSpecOcc, getSrcLoc ) import FiniteMap -import Maybes ( MaybeErr(..), catMaybes ) +import Maybes ( catMaybes, maybeToBool ) +import ErrUtils ( dumpIfSet_dyn ) +import BasicTypes ( Activation( AlwaysActive ) ) import Bag import List ( partition ) -import Util ( zipEqual, mapAccumL ) +import Util ( zipEqual, zipWithEqual, cmpList, lengthIs, + equalLength, lengthAtLeast, notNull ) import Outputable - +import FastString infixr 9 `thenSM` \end{code} @@ -574,20 +575,31 @@ Hence, the invariant is this: %************************************************************************ \begin{code} -specProgram :: UniqSupply -> [CoreBind] -> IO [CoreBind] -specProgram us binds +specProgram :: DynFlags -> UniqSupply -> [CoreBind] -> IO [CoreBind] +specProgram dflags us binds = do - beginPass "Specialise" + showPass dflags "Specialise" let binds' = initSM us (go binds `thenSM` \ (binds', uds') -> returnSM (dumpAllDictBinds uds' binds')) - endPass "Specialise" (opt_D_dump_spec || opt_D_verbose_core2core) binds' + endPass dflags "Specialise" Opt_D_dump_spec binds' + dumpIfSet_dyn dflags Opt_D_dump_rules "Top-level specialisations" + (vcat (map pprTidyIdRules (concat (map bindersOf binds')))) + + return binds' where + -- We need to start with a Subst that knows all the things + -- that are in scope, so that the substitution engine doesn't + -- accidentally re-use a unique that's already in use + -- Easiest thing is to do it all at once, as if all the top-level + -- decls were mutually recursive + top_subst = mkSubst (mkInScopeSet (mkVarSet (bindersOfBinds binds))) emptySubstEnv + go [] = returnSM ([], emptyUDs) - go (bind:binds) = go binds `thenSM` \ (binds', uds) -> - specBind bind uds `thenSM` \ (bind', uds') -> + go (bind:binds) = go binds `thenSM` \ (binds', uds) -> + specBind top_subst bind uds `thenSM` \ (bind', uds') -> returnSM (bind' ++ binds', uds') \end{code} @@ -598,70 +610,88 @@ specProgram us binds %************************************************************************ \begin{code} -specExpr :: CoreExpr -> SpecM (CoreExpr, UsageDetails) +specVar :: Subst -> Id -> CoreExpr +specVar subst v = case lookupIdSubst subst v of + DoneEx e -> e + DoneId v _ -> Var v + +specExpr :: Subst -> CoreExpr -> SpecM (CoreExpr, UsageDetails) +-- We carry a substitution down: +-- a) we must clone any binding that might flaot outwards, +-- to avoid name clashes +-- b) we carry a type substitution to use when analysing +-- the RHS of specialised bindings (no type-let!) ---------------- First the easy cases -------------------- -specExpr e@(Type _) = returnSM (e, emptyUDs) -specExpr e@(Var _) = returnSM (e, emptyUDs) +specExpr subst (Type ty) = returnSM (Type (substTy subst ty), emptyUDs) +specExpr subst (Var v) = returnSM (specVar subst v, emptyUDs) +specExpr subst (Lit lit) = returnSM (Lit lit, emptyUDs) -specExpr e@(Con con args) - = mapAndCombineSM specExpr args `thenSM` \ (args', uds) -> - returnSM (Con con args', uds) - -specExpr (Note note body) - = specExpr body `thenSM` \ (body', uds) -> - returnSM (Note note body', uds) +specExpr subst (Note note body) + = specExpr subst body `thenSM` \ (body', uds) -> + returnSM (Note (specNote subst note) body', uds) ---------------- Applications might generate a call instance -------------------- -specExpr expr@(App fun arg) +specExpr subst expr@(App fun arg) = go expr [] where - go (App fun arg) args = specExpr arg `thenSM` \ (arg', uds_arg) -> + go (App fun arg) args = specExpr subst arg `thenSM` \ (arg', uds_arg) -> go fun (arg':args) `thenSM` \ (fun', uds_app) -> returnSM (App fun' arg', uds_arg `plusUDs` uds_app) - go (Var f) args = returnSM (Var f, mkCallUDs f args) - go other args = specExpr other + go (Var f) args = case specVar subst f of + Var f' -> returnSM (Var f', mkCallUDs subst f' args) + e' -> returnSM (e', emptyUDs) -- I don't expect this! + go other args = specExpr subst other ---------------- Lambda/case require dumping of usage details -------------------- -specExpr e@(Lam _ _) - = specExpr body `thenSM` \ (body', uds) -> +specExpr subst e@(Lam _ _) + = specExpr subst' body `thenSM` \ (body', uds) -> let - (filtered_uds, body'') = dumpUDs bndrs uds body' + (filtered_uds, body'') = dumpUDs bndrs' uds body' in - returnSM (mkLams bndrs body'', filtered_uds) + returnSM (mkLams bndrs' body'', filtered_uds) where - (bndrs, body) = go [] e - + (bndrs, body) = collectBinders e + (subst', bndrs') = simplBndrs subst bndrs -- More efficient to collect a group of binders together all at once -- and we don't want to split a lambda group with dumped bindings - go bndrs (Lam bndr e) = go (bndr:bndrs) e - go bndrs e = (reverse bndrs, e) - -specExpr (Case scrut case_bndr alts) - = specExpr scrut `thenSM` \ (scrut', uds_scrut) -> +specExpr subst (Case scrut case_bndr alts) + = specExpr subst scrut `thenSM` \ (scrut', uds_scrut) -> mapAndCombineSM spec_alt alts `thenSM` \ (alts', uds_alts) -> - returnSM (Case scrut' case_bndr alts', uds_scrut `plusUDs` uds_alts) + returnSM (Case scrut' case_bndr' alts', uds_scrut `plusUDs` uds_alts) where + (subst_alt, case_bndr') = simplBndr subst case_bndr + -- No need to clone case binder; it can't float like a let(rec) + spec_alt (con, args, rhs) - = specExpr rhs `thenSM` \ (rhs', uds) -> + = specExpr subst_rhs rhs `thenSM` \ (rhs', uds) -> let (uds', rhs'') = dumpUDs args uds rhs' in - returnSM ((con, args, rhs''), uds') + returnSM ((con, args', rhs''), uds') + where + (subst_rhs, args') = simplBndrs subst_alt args ---------------- Finally, let is the interesting case -------------------- -specExpr (Let bind body) - = -- Deal with the body - specExpr body `thenSM` \ (body', body_uds) -> +specExpr subst (Let bind body) + = -- Clone binders + cloneBindSM subst bind `thenSM` \ (rhs_subst, body_subst, bind') -> + + -- Deal with the body + specExpr body_subst body `thenSM` \ (body', body_uds) -> -- Deal with the bindings - specBind bind body_uds `thenSM` \ (binds', uds) -> + specBind rhs_subst bind' body_uds `thenSM` \ (binds', uds) -> -- All done returnSM (foldr Let body' binds', uds) + +-- Must apply the type substitution to coerceions +specNote subst (Coerce t1 t2) = Coerce (substTy subst t1) (substTy subst t2) +specNote subst note = note \end{code} %************************************************************************ @@ -671,20 +701,14 @@ specExpr (Let bind body) %************************************************************************ \begin{code} -specBind :: CoreBind +specBind :: Subst -- Use this for RHSs + -> CoreBind -> UsageDetails -- Info on how the scope of the binding -> SpecM ([CoreBind], -- New bindings UsageDetails) -- And info to pass upstream -specBind bind@(NonRec bndr rhs) body_uds - | isSpecPragmaId bndr -- Aha! A spec-pragma Id. Collect UDs from - -- its RHS and discard it! - = specExpr rhs `thenSM` \ (rhs', rhs_uds) -> - returnSM ([], rhs_uds `plusUDs` body_uds) - - -specBind bind body_uds - = specBindItself bind (calls body_uds) `thenSM` \ (bind', bind_uds) -> +specBind rhs_subst bind body_uds + = specBindItself rhs_subst bind (calls body_uds) `thenSM` \ (bind', bind_uds) -> let bndrs = bindersOf bind all_uds = zapCalls bndrs (body_uds `plusUDs` bind_uds) @@ -728,8 +752,8 @@ mkBigUD bind dbs calls -- specBindItself deals with the RHS, specialising it according -- to the calls found in the body (if any) -specBindItself (NonRec bndr rhs) call_info - = specDefn call_info (bndr,rhs) `thenSM` \ ((bndr',rhs'), spec_defns, spec_uds) -> +specBindItself rhs_subst (NonRec bndr rhs) call_info + = specDefn rhs_subst call_info (bndr,rhs) `thenSM` \ ((bndr',rhs'), spec_defns, spec_uds) -> let new_bind | null spec_defns = NonRec bndr' rhs' | otherwise = Rec ((bndr',rhs'):spec_defns) @@ -738,8 +762,8 @@ specBindItself (NonRec bndr rhs) call_info in returnSM (new_bind, spec_uds) -specBindItself (Rec pairs) call_info - = mapSM (specDefn call_info) pairs `thenSM` \ stuff -> +specBindItself rhs_subst (Rec pairs) call_info + = mapSM (specDefn rhs_subst call_info) pairs `thenSM` \ stuff -> let (pairs', spec_defns_s, spec_uds_s) = unzip3 stuff spec_defns = concat spec_defns_s @@ -749,7 +773,8 @@ specBindItself (Rec pairs) call_info returnSM (new_bind, spec_uds) -specDefn :: CallDetails -- Info on how it is used in its scope +specDefn :: Subst -- Subst to use for RHS + -> CallDetails -- Info on how it is used in its scope -> (Id, CoreExpr) -- The thing being bound and its un-processed RHS -> SpecM ((Id, CoreExpr), -- The thing and its processed RHS -- the Id may now have specialisations attached @@ -757,40 +782,53 @@ specDefn :: CallDetails -- Info on how it is used in its scope UsageDetails -- Stuff to fling upwards from the RHS and its ) -- specialised versions -specDefn calls (fn, rhs) +specDefn subst calls (fn, rhs) -- The first case is the interesting one - | n_tyvars == length rhs_tyvars -- Rhs of fn's defn has right number of big lambdas - && n_dicts <= length rhs_bndrs -- and enough dict args - && not (null calls_for_me) -- And there are some calls to specialise + | rhs_tyvars `lengthIs` n_tyvars -- Rhs of fn's defn has right number of big lambdas + && rhs_bndrs `lengthAtLeast` n_dicts -- and enough dict args + && notNull calls_for_me -- And there are some calls to specialise + +-- At one time I tried not specialising small functions +-- but sometimes there are big functions marked INLINE +-- that we'd like to specialise. In particular, dictionary +-- functions, which Marcin is keen to inline +-- && not (certainlyWillInline fn) -- And it's not small + -- If it's small, it's better just to inline + -- it than to construct lots of specialisations = -- Specialise the body of the function - specExpr body `thenSM` \ (body', body_uds) -> - let - (float_uds, bound_uds@(dict_binds,_)) = splitUDs rhs_bndrs body_uds - in + specExpr subst rhs `thenSM` \ (rhs', rhs_uds) -> -- Make a specialised version for each call in calls_for_me - mapSM (spec_call bound_uds) calls_for_me `thenSM` \ stuff -> + mapSM spec_call calls_for_me `thenSM` \ stuff -> let - (spec_defns, spec_uds, spec_env_stuff) = unzip3 stuff + (spec_defns, spec_uds, spec_rules) = unzip3 stuff - fn' = addIdSpecialisations fn spec_env_stuff - rhs' = mkLams rhs_bndrs (mkDictLets dict_binds body') + fn' = addIdSpecialisations zapped_fn spec_rules in returnSM ((fn',rhs'), spec_defns, - float_uds `plusUDs` plusUDList spec_uds) + rhs_uds `plusUDs` plusUDList spec_uds) | otherwise -- No calls or RHS doesn't fit our preconceptions - = specExpr rhs `thenSM` \ (rhs', rhs_uds) -> - returnSM ((fn, rhs'), [], rhs_uds) + = specExpr subst rhs `thenSM` \ (rhs', rhs_uds) -> + returnSM ((zapped_fn, rhs'), [], rhs_uds) where - fn_type = idType fn - (tyvars, theta, tau) = splitSigmaTy fn_type - n_tyvars = length tyvars - n_dicts = length theta + zapped_fn = zapSpecPragmaId fn + -- If the fn is a SpecPragmaId, make it discardable + -- It's role as a holder for a call instance is o'er + -- But it might be alive for some other reason by now. + + fn_type = idType fn + (tyvars, theta, _) = tcSplitSigmaTy fn_type + n_tyvars = length tyvars + n_dicts = length theta + + -- It's important that we "see past" any INLINE pragma + -- else we'll fail to specialise an INLINE thing + (inline_me, rhs') = dropInline rhs + (rhs_tyvars, rhs_ids, rhs_body) = collectTyAndValBinders rhs' - (rhs_tyvars, rhs_ids, rhs_body) = collectTyAndValBinders rhs rhs_dicts = take n_dicts rhs_ids rhs_bndrs = rhs_tyvars ++ rhs_dicts body = mkLams (drop n_dicts rhs_ids) rhs_body @@ -802,70 +840,79 @@ specDefn calls (fn, rhs) ---------------------------------------------------------- -- Specialise to one particular call pattern - spec_call :: ProtoUsageDetails -- From the original body, captured by - -- the dictionary lambdas - -> ([Maybe Type], ([DictExpr], IdOrTyVarSet)) -- Call instance - -> SpecM ((Id,CoreExpr), -- Specialised definition - UsageDetails, -- Usage details from specialised body - ([TyVar], [Type], CoreExpr)) -- Info for the Id's SpecEnv - spec_call bound_uds (call_ts, (call_ds, _)) - = ASSERT( length call_ts == n_tyvars && length call_ds == n_dicts ) + spec_call :: (CallKey, ([DictExpr], VarSet)) -- Call instance + -> SpecM ((Id,CoreExpr), -- Specialised definition + UsageDetails, -- Usage details from specialised body + CoreRule) -- Info for the Id's SpecEnv + spec_call (CallKey call_ts, (call_ds, call_fvs)) + = ASSERT( call_ts `lengthIs` n_tyvars && call_ds `lengthIs` n_dicts ) -- Calls are only recorded for properly-saturated applications - -- Supppose the call is for f [Just t1, Nothing, Just t3, Nothing] [d1, d2] - - -- Construct the new binding - -- f1 = /\ b d -> (..rhs of f..) t1 b t3 d d1 d2 - -- and the type of this binder - let - mk_spec_ty Nothing = newTyVarSM `thenSM` \ tyvar -> - returnSM (Just tyvar, mkTyVarTy tyvar) - mk_spec_ty (Just ty) = returnSM (Nothing, ty) - in - mapSM mk_spec_ty call_ts `thenSM` \ stuff -> + -- Suppose f's defn is f = /\ a b c d -> \ d1 d2 -> rhs + -- Supppose the call is for f [Just t1, Nothing, Just t3, Nothing] [dx1, dx2] + + -- Construct the new binding + -- f1 = SUBST[a->t1,c->t3, d1->d1', d2->d2'] (/\ b d -> rhs) + -- PLUS the usage-details + -- { d1' = dx1; d2' = dx2 } + -- where d1', d2' are cloned versions of d1,d2, with the type substitution applied. + -- + -- Note that the substitution is applied to the whole thing. + -- This is convenient, but just slightly fragile. Notably: + -- * There had better be no name clashes in a/b/c/d + -- let - (maybe_spec_tyvars, spec_tys) = unzip stuff - spec_tyvars = catMaybes maybe_spec_tyvars - spec_rhs = mkLams spec_tyvars $ - mkApps rhs (map Type spec_tys ++ call_ds) - spec_id_ty = mkForAllTys spec_tyvars (substTy ty_env tau) - ty_env = zipVarEnv tyvars spec_tys + -- poly_tyvars = [b,d] in the example above + -- spec_tyvars = [a,c] + -- ty_args = [t1,b,t3,d] + poly_tyvars = [tv | (tv, Nothing) <- rhs_tyvars `zip` call_ts] + spec_tyvars = [tv | (tv, Just _) <- rhs_tyvars `zip` call_ts] + ty_args = zipWithEqual "spec_call" mk_ty_arg rhs_tyvars call_ts + where + mk_ty_arg rhs_tyvar Nothing = Type (mkTyVarTy rhs_tyvar) + mk_ty_arg rhs_tyvar (Just ty) = Type ty + rhs_subst = extendSubstList subst spec_tyvars [DoneTy ty | Just ty <- call_ts] in - - newIdSM fn spec_id_ty `thenSM` \ spec_f -> - - - -- Construct the stuff for f's spec env - -- [b,d] [t1,b,t3,d] |-> \d1 d2 -> f1 b d - -- The only awkward bit is that d1,d2 might well be global - -- dictionaries, so it's tidier to make new local variables - -- for the lambdas in the RHS, rather than lambda-bind the - -- dictionaries themselves. - -- - -- In fact we use the standard template locals, so that the - -- they don't need to be "tidied" before putting in interface files + cloneBinders rhs_subst rhs_dicts `thenSM` \ (rhs_subst', rhs_dicts') -> let - arg_ds = mkTemplateLocals (map coreExprType call_ds) - spec_env_rhs = mkLams arg_ds $ - mkTyApps (Var spec_f) $ - map mkTyVarTy spec_tyvars - spec_env_info = (spec_tyvars, spec_tys, spec_env_rhs) - in - - -- Specialise the UDs from f's RHS - let - -- Only the overloaded tyvars should be free in the uds - ty_env = mkVarEnv [ (rhs_tyvar, ty) - | (rhs_tyvar, Just ty) <- zipEqual "specUDs1" rhs_tyvars call_ts - ] - dict_env = zipVarEnv rhs_dicts (map Done call_ds) + inst_args = ty_args ++ map Var rhs_dicts' + + -- Figure out the type of the specialised function + spec_id_ty = mkForAllTys poly_tyvars (applyTypeToArgs rhs fn_type inst_args) in - specUDs ty_env dict_env bound_uds `thenSM` \ spec_uds -> + newIdSM fn spec_id_ty `thenSM` \ spec_f -> + specExpr rhs_subst' (mkLams poly_tyvars body) `thenSM` \ (spec_rhs, rhs_uds) -> + let + -- The rule to put in the function's specialisation is: + -- forall b,d, d1',d2'. f t1 b t3 d d1' d2' = f1 b d + spec_env_rule = Rule (mkFastString ("SPEC " ++ showSDoc (ppr fn))) + AlwaysActive + (poly_tyvars ++ rhs_dicts') + inst_args + (mkTyApps (Var spec_f) (map mkTyVarTy poly_tyvars)) + + -- Add the { d1' = dx1; d2' = dx2 } usage stuff + final_uds = foldr addDictBind rhs_uds (my_zipEqual "spec_call" rhs_dicts' call_ds) + + -- NOTE: we don't add back in any INLINE pragma on the RHS, so even if + -- the original function said INLINE, the specialised copies won't. + -- The idea is that the point of inlining was precisely to specialise + -- the function at its call site, and that's not so important for the + -- specialised copies. But it still smells like an ad hoc decision. - returnSM ((spec_f, spec_rhs), - spec_uds, - spec_env_info - ) + in + returnSM ((spec_f, spec_rhs), + final_uds, + spec_env_rule) + + where + my_zipEqual doc xs ys + | not (equalLength xs ys) = pprPanic "my_zipEqual" (ppr xs $$ ppr ys $$ (ppr fn <+> ppr call_ts) $$ ppr rhs) + | otherwise = zipEqual doc xs ys + +dropInline :: CoreExpr -> (Bool, CoreExpr) +dropInline (Note InlineMe rhs) = (True, rhs) +dropInline rhs = (False, rhs) \end{code} %************************************************************************ @@ -875,8 +922,6 @@ specDefn calls (fn, rhs) %************************************************************************ \begin{code} -type FreeDicts = IdSet - data UsageDetails = MkUD { dict_binds :: !(Bag DictBind), @@ -884,12 +929,11 @@ data UsageDetails -- The order is important; -- in ds1 `union` ds2, bindings in ds2 can depend on those in ds1 -- (Remember, Bags preserve order in GHC.) - -- The FreeDicts is the free vars of the RHS calls :: !CallDetails } -type DictBind = (CoreBind, IdOrTyVarSet) +type DictBind = (CoreBind, VarSet) -- The set is the free vars of the binding -- both tyvars and dicts @@ -898,31 +942,49 @@ type DictExpr = CoreExpr emptyUDs = MkUD { dict_binds = emptyBag, calls = emptyFM } type ProtoUsageDetails = ([DictBind], - [(Id, [Maybe Type], ([DictExpr], IdOrTyVarSet))] + [(Id, CallKey, ([DictExpr], VarSet))] ) ------------------------------------------------------------ type CallDetails = FiniteMap Id CallInfo -type CallInfo = FiniteMap [Maybe Type] -- Nothing => unconstrained type argument - ([DictExpr], IdSet) -- Dict args and the free dicts - -- free dicts does *not* include the main id itself +newtype CallKey = CallKey [Maybe Type] -- Nothing => unconstrained type argument +type CallInfo = FiniteMap CallKey + ([DictExpr], VarSet) -- Dict args and the vars of the whole + -- call (including tyvars) + -- [*not* include the main id itself, of course] -- The finite maps eliminate duplicates -- The list of types and dictionaries is guaranteed to -- match the type of f +-- Type isn't an instance of Ord, so that we can control which +-- instance we use. That's tiresome here. Oh well +instance Eq CallKey where + k1 == k2 = case k1 `compare` k2 of { EQ -> True; other -> False } + +instance Ord CallKey where + compare (CallKey k1) (CallKey k2) = cmpList cmp k1 k2 + where + cmp Nothing Nothing = EQ + cmp Nothing (Just t2) = LT + cmp (Just t1) Nothing = GT + cmp (Just t1) (Just t2) = tcCmpType t1 t2 + unionCalls :: CallDetails -> CallDetails -> CallDetails unionCalls c1 c2 = plusFM_C plusFM c1 c2 -singleCall (id, tys, dicts) - = unitFM id (unitFM tys (dicts, dict_fvs)) +singleCall :: Id -> [Maybe Type] -> [DictExpr] -> CallDetails +singleCall id tys dicts + = unitFM id (unitFM (CallKey tys) (dicts, call_fvs)) where - dict_fvs = foldr (unionVarSet . exprFreeVars) emptyVarSet dicts + call_fvs = exprsFreeVars dicts `unionVarSet` tys_fvs + tys_fvs = tyVarsOfTypes (catMaybes tys) -- The type args (tys) are guaranteed to be part of the dictionary -- types, because they are just the constrained types, -- and the dictionary is therefore sure to be bound -- inside the binding for any type variables free in the type; -- hence it's safe to neglect tyvars free in tys when making -- the free-var set for this call + -- BUT I don't trust this reasoning; play safe and include tys_fvs -- -- We don't include the 'id' itself. @@ -934,32 +996,40 @@ listToCallDetails calls callDetailsToList calls = [ (id,tys,dicts) | (id,fm) <- fmToList calls, - (tys,dicts) <- fmToList fm + (tys, dicts) <- fmToList fm ] -mkCallUDs f args +mkCallUDs subst f args | null theta - || length spec_tys /= n_tyvars - || length dicts /= n_dicts - = emptyUDs -- Not overloaded + || not (all isClassPred theta) + -- Only specialise if all overloading is on class params. + -- In ptic, with implicit params, the type args + -- *don't* say what the value of the implicit param is! + || not (spec_tys `lengthIs` n_tyvars) + || not ( dicts `lengthIs` n_dicts) + || maybeToBool (lookupRule (\act -> True) (substInScope subst) f args) + -- There's already a rule covering this call. A typical case + -- is where there's an explicit user-provided rule. Then + -- we don't want to create a specialised version + -- of the function that overlaps. + = emptyUDs -- Not overloaded, or no specialisation wanted | otherwise = MkUD {dict_binds = emptyBag, - calls = singleCall (f, spec_tys, dicts) + calls = singleCall f spec_tys dicts } where - (tyvars, theta, tau) = splitSigmaTy (idType f) - constrained_tyvars = foldr (unionVarSet . tyVarsOfTypes . snd) emptyVarSet theta - n_tyvars = length tyvars - n_dicts = length theta + (tyvars, theta, _) = tcSplitSigmaTy (idType f) + constrained_tyvars = tyVarsOfTheta theta + n_tyvars = length tyvars + n_dicts = length theta spec_tys = [mk_spec_ty tv ty | (tv, Type ty) <- tyvars `zip` args] dicts = [dict_expr | (_, dict_expr) <- theta `zip` (drop n_tyvars args)] - mk_spec_ty tyvar ty | tyvar `elemVarSet` constrained_tyvars - = Just ty - | otherwise - = Nothing + mk_spec_ty tyvar ty + | tyvar `elemVarSet` constrained_tyvars = Just ty + | otherwise = Nothing ------------------------------------------------------------ plusUDs :: UsageDetails -> UsageDetails -> UsageDetails @@ -978,32 +1048,26 @@ zapCalls ids uds = uds {calls = delListFromFM (calls uds) ids} mkDB bind = (bind, bind_fvs bind) bind_fvs (NonRec bndr rhs) = exprFreeVars rhs -bind_fvs (Rec prs) = foldl delVarSet rhs_fvs (map fst prs) +bind_fvs (Rec prs) = foldl delVarSet rhs_fvs bndrs where - rhs_fvs = foldr (unionVarSet . exprFreeVars . snd) emptyVarSet prs + bndrs = map fst prs + rhs_fvs = unionVarSets [exprFreeVars rhs | (bndr,rhs) <- prs] -addDictBind uds bind = uds { dict_binds = mkDB bind `consBag` dict_binds uds } +addDictBind (dict,rhs) uds = uds { dict_binds = mkDB (NonRec dict rhs) `consBag` dict_binds uds } dumpAllDictBinds (MkUD {dict_binds = dbs}) binds = foldrBag add binds dbs where add (bind,_) binds = bind : binds -mkDictBinds :: [DictBind] -> [CoreBind] -mkDictBinds = map fst - -mkDictLets :: [DictBind] -> CoreExpr -> CoreExpr -mkDictLets dbs body = foldr mk body dbs - where - mk (bind,_) e = Let bind e - dumpUDs :: [CoreBndr] -> UsageDetails -> CoreExpr -> (UsageDetails, CoreExpr) dumpUDs bndrs uds body - = (free_uds, mkDictLets dict_binds body) + = (free_uds, foldr add_let body dict_binds) where (free_uds, (dict_binds, _)) = splitUDs bndrs uds + add_let (bind,_) body = Let bind body splitUDs :: [CoreBndr] -> UsageDetails @@ -1047,44 +1111,6 @@ splitUDs bndrs uds@(MkUD {dict_binds = orig_dbs, = (free_dbs `snocBag` db, dump_dbs, dump_idset) \end{code} -Given a type and value substitution, specUDs creates a specialised copy of -the given UDs - -\begin{code} -specUDs :: TyVarSubst -> IdSubst -> ProtoUsageDetails -> SpecM UsageDetails -specUDs tv_env dict_env (dbs, calls) - = getUniqSupplySM `thenSM` \ us -> - let - ((us', dict_env'), dbs') = mapAccumL specDB (us, dict_env) dbs - in - setUniqSupplySM us' `thenSM_` - returnSM (MkUD { dict_binds = listToBag dbs', - calls = foldr (unionCalls . singleCall . inst_call dict_env') - emptyFM calls - }) - where - inst_call dict_env (id, tys, (dicts,fvs)) = (id, map (inst_maybe_ty fvs) tys, - map (substExpr tv_env dict_env fvs) dicts) - - inst_maybe_ty fvs Nothing = Nothing - inst_maybe_ty fvs (Just ty) = Just (fullSubstTy tv_env fvs ty) - - specDB (us, dict_env) (NonRec bndr rhs, fvs) - = ((us', dict_env'), mkDB (NonRec bndr' (substExpr tv_env dict_env fvs rhs))) - where - (dict_env', _, us', bndr') = substId clone_fn tv_env dict_env fvs us bndr - -- Fudge the in_scope set a bit by using the free vars of - -- the binding, and ignoring the one that comes back - - specDB (us, dict_env) (Rec prs, fvs) - = ((us', dict_env'), mkDB (Rec (bndrs' `zip` rhss'))) - where - (dict_env', _, us', bndrs') = substIds clone_fn tv_env dict_env fvs us (map fst prs) - rhss' = [substExpr tv_env dict_env' fvs rhs | (_, rhs) <- prs] - - clone_fn _ us id = case splitUniqSupply us of - (us1, us2) -> Just (us1, setVarUnique id (uniqFromSupply us2)) -\end{code} %************************************************************************ %* * @@ -1093,54 +1119,48 @@ specUDs tv_env dict_env (dbs, calls) %************************************************************************ \begin{code} -lookupId:: IdEnv Id -> Id -> Id -lookupId env id = case lookupVarEnv env id of - Nothing -> id - Just id' -> id' - -addIdSpecialisations id spec_stuff - = (if not (null errs) then - pprTrace "Duplicate specialisations" (vcat (map ppr errs)) - else \x -> x - ) - setIdSpecialisation id new_spec_env - where - (new_spec_env, errs) = foldr add (getIdSpecialisation id, []) spec_stuff - - add (tyvars, tys, template) (spec_env, errs) - = case addToSpecEnv True spec_env tyvars tys template of - Succeeded spec_env' -> (spec_env', errs) - Failed err -> (spec_env, err:errs) - ----------------------------------------- type SpecM a = UniqSM a thenSM = thenUs -thenSM_ = thenUs_ returnSM = returnUs getUniqSM = getUniqueUs -getUniqSupplySM = getUs -setUniqSupplySM = setUs mapSM = mapUs -initSM = initUs +initSM = initUs_ mapAndCombineSM f [] = returnSM ([], emptyUDs) mapAndCombineSM f (x:xs) = f x `thenSM` \ (y, uds1) -> mapAndCombineSM f xs `thenSM` \ (ys, uds2) -> returnSM (y:ys, uds1 `plusUDs` uds2) +cloneBindSM :: Subst -> CoreBind -> SpecM (Subst, Subst, CoreBind) +-- Clone the binders of the bind; return new bind with the cloned binders +-- Return the substitution to use for RHSs, and the one to use for the body +cloneBindSM subst (NonRec bndr rhs) + = getUs `thenUs` \ us -> + let + (subst', bndr') = substAndCloneId subst us bndr + in + returnUs (subst, subst', NonRec bndr' rhs) + +cloneBindSM subst (Rec pairs) + = getUs `thenUs` \ us -> + let + (subst', bndrs') = substAndCloneRecIds subst us (map fst pairs) + in + returnUs (subst', subst', Rec (bndrs' `zip` map snd pairs)) + +cloneBinders subst bndrs + = getUs `thenUs` \ us -> + returnUs (substAndCloneIds subst us bndrs) + newIdSM old_id new_ty = getUniqSM `thenSM` \ uniq -> let -- Give the new Id a similar occurrence name to the old one - new_id = mkUserLocal (mkSpecOcc (nameOccName name)) uniq new_ty (getSrcLoc name) name = idName old_id + new_id = mkUserLocal (mkSpecOcc (nameOccName name)) uniq new_ty (getSrcLoc name) in returnSM new_id - -newTyVarSM - = getUniqSM `thenSM` \ uniq -> - returnSM (mkSysTyVar uniq boxedTypeKind) \end{code}