X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Fspecialise%2FSpecialise.lhs;h=0e66b0bc7820d7cd4dfa1d7ac42e6f7f83727416;hb=df85c4b4a403c1e17d3f79fe91109ffbe6ba60b7;hp=52eae0436b30b4f4bc94bff114c472f2e6519704;hpb=d069cec2bd92d4156aeab80f7eb1f222a82e4103;p=ghc-hetmet.git diff --git a/ghc/compiler/specialise/Specialise.lhs b/ghc/compiler/specialise/Specialise.lhs index 52eae04..0e66b0b 100644 --- a/ghc/compiler/specialise/Specialise.lhs +++ b/ghc/compiler/specialise/Specialise.lhs @@ -8,43 +8,41 @@ module Specialise ( specProgram ) where #include "HsVersions.h" -import CmdLineOpts ( DynFlags, DynFlag(..) ) -import Id ( Id, idName, idType, mkUserLocal, - idSpecialisation, modifyIdInfo - ) +import DynFlags ( DynFlags, DynFlag(..) ) +import Id ( Id, idName, idType, mkUserLocal ) import TcType ( Type, mkTyVarTy, tcSplitSigmaTy, - tyVarsOfTypes, tyVarsOfTheta, - mkForAllTys, tcCmpType + tyVarsOfTypes, tyVarsOfTheta, isClassPred, + tcCmpType, isUnLiftedType ) -import Subst ( Subst, mkSubst, substTy, mkSubst, extendSubstList, mkInScopeSet, - simplBndr, simplBndrs, - substAndCloneId, substAndCloneIds, substAndCloneRecIds, - lookupIdSubst, substInScope +import CoreSubst ( Subst, mkEmptySubst, extendTvSubstList, lookupIdSubst, + substBndr, substBndrs, substTy, substInScope, + cloneIdBndr, cloneIdBndrs, cloneRecIdBndrs ) -import Var ( zapSpecPragmaId ) import VarSet import VarEnv import CoreSyn -import CoreUtils ( applyTypeToArgs ) -import CoreUnfold ( certainlyWillInline ) -import CoreFVs ( exprFreeVars, exprsFreeVars ) +import CoreUtils ( applyTypeToArgs, mkPiTypes ) +import CoreFVs ( exprFreeVars, exprsFreeVars, idRuleVars ) +import CoreTidy ( tidyRules ) import CoreLint ( showPass, endPass ) -import PprCore ( pprCoreRules ) -import Rules ( addIdSpecialisations, lookupRule ) - +import Rules ( addIdSpecialisations, mkLocalRule, lookupRule, emptyRuleBase, rulesOfBinds ) +import PprCore ( pprRules ) import UniqSupply ( UniqSupply, UniqSM, initUs_, thenUs, returnUs, getUniqueUs, getUs, mapUs ) import Name ( nameOccName, mkSpecOcc, getSrcLoc ) +import MkId ( voidArgId, realWorldPrimId ) import FiniteMap import Maybes ( catMaybes, maybeToBool ) import ErrUtils ( dumpIfSet_dyn ) +import BasicTypes ( Activation( AlwaysActive ) ) import Bag import List ( partition ) -import Util ( zipEqual, zipWithEqual, cmpList ) +import Util ( zipEqual, zipWithEqual, cmpList, lengthIs, + equalLength, lengthAtLeast, notNull ) import Outputable - +import FastString infixr 9 `thenSM` \end{code} @@ -587,7 +585,7 @@ specProgram dflags us binds endPass dflags "Specialise" Opt_D_dump_spec binds' dumpIfSet_dyn dflags Opt_D_dump_rules "Top-level specialisations" - (vcat (map dump_specs (concat (map bindersOf binds')))) + (pprRules (tidyRules emptyTidyEnv (rulesOfBinds binds'))) return binds' where @@ -596,14 +594,12 @@ specProgram dflags us binds -- 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 + top_subst = mkEmptySubst (mkInScopeSet (mkVarSet (bindersOfBinds binds))) go [] = returnSM ([], emptyUDs) go (bind:binds) = go binds `thenSM` \ (binds', uds) -> specBind top_subst bind uds `thenSM` \ (bind', uds') -> returnSM (bind' ++ binds', uds') - -dump_specs var = pprCoreRules var (idSpecialisation var) \end{code} %************************************************************************ @@ -614,9 +610,7 @@ dump_specs var = pprCoreRules var (idSpecialisation var) \begin{code} specVar :: Subst -> Id -> CoreExpr -specVar subst v = case lookupIdSubst subst v of - DoneEx e -> e - DoneId v _ -> Var v +specVar subst v = lookupIdSubst subst v specExpr :: Subst -> CoreExpr -> SpecM (CoreExpr, UsageDetails) -- We carry a substitution down: @@ -657,16 +651,16 @@ specExpr subst e@(Lam _ _) returnSM (mkLams bndrs' body'', filtered_uds) where (bndrs, body) = collectBinders e - (subst', bndrs') = simplBndrs subst bndrs + (subst', bndrs') = substBndrs 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 -specExpr subst (Case scrut case_bndr alts) - = specExpr subst scrut `thenSM` \ (scrut', uds_scrut) -> +specExpr subst (Case scrut case_bndr ty 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' (substTy subst ty) alts', uds_scrut `plusUDs` uds_alts) where - (subst_alt, case_bndr') = simplBndr subst case_bndr + (subst_alt, case_bndr') = substBndr subst case_bndr -- No need to clone case binder; it can't float like a let(rec) spec_alt (con, args, rhs) @@ -676,7 +670,7 @@ specExpr subst (Case scrut case_bndr alts) in returnSM ((con, args', rhs''), uds') where - (subst_rhs, args') = simplBndrs subst_alt args + (subst_rhs, args') = substBndrs subst_alt args ---------------- Finally, let is the interesting case -------------------- specExpr subst (Let bind body) @@ -787,10 +781,15 @@ specDefn :: Subst -- Subst to use for 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 - && not (certainlyWillInline fn) -- And it's not small + | 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 @@ -801,7 +800,7 @@ specDefn subst calls (fn, rhs) let (spec_defns, spec_uds, spec_rules) = unzip3 stuff - fn' = addIdSpecialisations zapped_fn spec_rules + fn' = addIdSpecialisations fn spec_rules in returnSM ((fn',rhs'), spec_defns, @@ -809,20 +808,19 @@ specDefn subst calls (fn, rhs) | otherwise -- No calls or RHS doesn't fit our preconceptions = specExpr subst rhs `thenSM` \ (rhs', rhs_uds) -> - returnSM ((zapped_fn, rhs'), [], rhs_uds) + returnSM ((fn, rhs'), [], rhs_uds) where - 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 - (rhs_tyvars, rhs_ids, rhs_body) = collectTyAndValBinders rhs + (rhs_tyvars, rhs_ids, rhs_body) + = collectTyAndValBinders (dropInline rhs) + -- It's important that we "see past" any INLINE pragma + -- else we'll fail to specialise an INLINE thing + rhs_dicts = take n_dicts rhs_ids rhs_bndrs = rhs_tyvars ++ rhs_dicts body = mkLams (drop n_dicts rhs_ids) rhs_body @@ -839,7 +837,7 @@ specDefn subst calls (fn, rhs) UsageDetails, -- Usage details from specialised body CoreRule) -- Info for the Id's SpecEnv spec_call (CallKey call_ts, (call_ds, call_fvs)) - = ASSERT( length call_ts == n_tyvars && length call_ds == n_dicts ) + = ASSERT( call_ts `lengthIs` n_tyvars && call_ds `lengthIs` n_dicts ) -- Calls are only recorded for properly-saturated applications -- Suppose f's defn is f = /\ a b c d -> \ d1 d2 -> rhs @@ -865,36 +863,53 @@ specDefn subst calls (fn, rhs) 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] + rhs_subst = extendTvSubstList subst (spec_tyvars `zip` [ty | Just ty <- call_ts]) in cloneBinders rhs_subst rhs_dicts `thenSM` \ (rhs_subst', rhs_dicts') -> let 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) + body_ty = applyTypeToArgs rhs fn_type inst_args + (lam_args, app_args) -- Add a dummy argument if body_ty is unlifted + | isUnLiftedType body_ty -- C.f. WwLib.mkWorkerArgs + = (poly_tyvars ++ [voidArgId], poly_tyvars ++ [realWorldPrimId]) + | otherwise = (poly_tyvars, poly_tyvars) + spec_id_ty = mkPiTypes lam_args body_ty in newIdSM fn spec_id_ty `thenSM` \ spec_f -> - specExpr rhs_subst' (mkLams poly_tyvars body) `thenSM` \ (spec_rhs, rhs_uds) -> + specExpr rhs_subst' (mkLams lam_args 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 (_PK_ ("SPEC " ++ showSDoc (ppr fn))) + spec_env_rule = mkLocalRule (mkFastString ("SPEC " ++ showSDoc (ppr fn))) + AlwaysActive (idName fn) (poly_tyvars ++ rhs_dicts') inst_args - (mkTyApps (Var spec_f) (map mkTyVarTy poly_tyvars)) + (mkVarApps (Var spec_f) app_args) -- 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. + in - returnSM ((spec_f, spec_rhs), + returnSM ((spec_f, spec_rhs), final_uds, spec_env_rule) where my_zipEqual doc xs ys - | length xs /= length ys = pprPanic "my_zipEqual" (ppr xs $$ ppr ys $$ (ppr fn <+> ppr call_ts) $$ ppr rhs) - | otherwise = zipEqual doc xs ys + | not (equalLength xs ys) = pprPanic "my_zipEqual" (ppr xs $$ ppr ys $$ (ppr fn <+> ppr call_ts) $$ ppr rhs) + | otherwise = zipEqual doc xs ys + +dropInline :: CoreExpr -> CoreExpr +dropInline (Note InlineMe rhs) = rhs +dropInline rhs = rhs \end{code} %************************************************************************ @@ -983,9 +998,13 @@ callDetailsToList calls = [ (id,tys,dicts) mkCallUDs subst f args | null theta - || length spec_tys /= n_tyvars - || length dicts /= n_dicts - || maybeToBool (lookupRule (substInScope subst) f args) + || 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) emptyRuleBase 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 @@ -1005,10 +1024,9 @@ mkCallUDs subst f args 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 @@ -1026,11 +1044,16 @@ zapCalls ids uds = uds {calls = delListFromFM (calls uds) ids} mkDB bind = (bind, bind_fvs bind) -bind_fvs (NonRec bndr rhs) = exprFreeVars rhs +bind_fvs (NonRec bndr rhs) = pair_fvs (bndr,rhs) bind_fvs (Rec prs) = foldl delVarSet rhs_fvs bndrs where bndrs = map fst prs - rhs_fvs = unionVarSets [exprFreeVars rhs | (bndr,rhs) <- prs] + rhs_fvs = unionVarSets (map pair_fvs prs) + +pair_fvs (bndr, rhs) = exprFreeVars rhs `unionVarSet` idRuleVars bndr + -- Don't forget variables mentioned in the + -- rules of the bndr. C.f. OccAnal.addRuleUsage + addDictBind (dict,rhs) uds = uds { dict_binds = mkDB (NonRec dict rhs) `consBag` dict_binds uds } @@ -1084,7 +1107,7 @@ splitUDs bndrs uds@(MkUD {dict_binds = orig_dbs, dump_db (free_dbs, dump_dbs, dump_idset) db@(bind, fvs) | dump_idset `intersectsVarSet` fvs -- Dump it = (free_dbs, dump_dbs `snocBag` db, - dump_idset `unionVarSet` mkVarSet (bindersOf bind)) + extendVarSetList dump_idset (bindersOf bind)) | otherwise -- Don't dump it = (free_dbs `snocBag` db, dump_dbs, dump_idset) @@ -1098,12 +1121,6 @@ splitUDs bndrs uds@(MkUD {dict_binds = orig_dbs, %************************************************************************ \begin{code} -lookupId:: IdEnv Id -> Id -> Id -lookupId env id = case lookupVarEnv env id of - Nothing -> id - Just id' -> id' - ----------------------------------------- type SpecM a = UniqSM a thenSM = thenUs @@ -1123,20 +1140,20 @@ cloneBindSM :: Subst -> CoreBind -> SpecM (Subst, Subst, CoreBind) cloneBindSM subst (NonRec bndr rhs) = getUs `thenUs` \ us -> let - (subst', bndr') = substAndCloneId subst us bndr + (subst', bndr') = cloneIdBndr 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) + (subst', bndrs') = cloneRecIdBndrs 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) + returnUs (cloneIdBndrs subst us bndrs) newIdSM old_id new_ty = getUniqSM `thenSM` \ uniq ->