X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FbasicTypes%2FMkId.lhs;h=97adb9454569d2a8b6f7c2713f3061f0d6decd86;hb=c01030fe3c628d2be3250e309dd8e933f2011e3a;hp=761eef8248bde76d8ddd801bb9ae52df7159aa8e;hpb=729046306d0a028ebfc01d29006e3aa35e9d1bab;p=ghc-hetmet.git diff --git a/ghc/compiler/basicTypes/MkId.lhs b/ghc/compiler/basicTypes/MkId.lhs index 761eef8..97adb94 100644 --- a/ghc/compiler/basicTypes/MkId.lhs +++ b/ghc/compiler/basicTypes/MkId.lhs @@ -22,7 +22,7 @@ module MkId ( -- And some particular Ids; see below for why they are wired in wiredInIds, - unsafeCoerceId, realWorldPrimId, + unsafeCoerceId, realWorldPrimId, nullAddrId, eRROR_ID, eRROR_CSTRING_ID, rEC_SEL_ERROR_ID, pAT_ERROR_ID, rEC_CON_ERROR_ID, rEC_UPD_ERROR_ID, iRREFUT_PAT_ERROR_ID, nON_EXHAUSTIVE_GUARDS_ERROR_ID, nO_METHOD_BINDING_ERROR_ID, aBSENT_ERROR_ID, pAR_ERROR_ID @@ -32,11 +32,11 @@ module MkId ( import BasicTypes ( Arity, StrictnessMark(..), isMarkedUnboxed, isMarkedStrict ) -import TysPrim ( openAlphaTyVars, alphaTyVar, alphaTy, +import TysPrim ( openAlphaTyVars, alphaTyVar, alphaTy, betaTyVar, betaTy, intPrimTy, realWorldStatePrimTy, addrPrimTy ) import TysWiredIn ( charTy, mkListTy ) -import PrelRules ( primOpRule ) +import PrelRules ( primOpRules ) import Rules ( addRule ) import TcType ( Type, ThetaType, mkDictTy, mkPredTys, mkTyConApp, mkTyVarTys, mkClassPred, tcEqPred, @@ -45,9 +45,9 @@ import TcType ( Type, ThetaType, mkDictTy, mkPredTys, mkTyConApp, tcSplitFunTys, tcSplitForAllTys, mkPredTy ) import Module ( Module ) -import CoreUtils ( exprType, mkInlineMe ) +import CoreUtils ( mkInlineMe, exprType ) import CoreUnfold ( mkTopUnfolding, mkCompulsoryUnfolding, mkOtherCon ) -import Literal ( Literal(..) ) +import Literal ( Literal(..), nullAddrLit ) import TyCon ( TyCon, isNewTyCon, tyConTyVars, tyConDataCons, tyConTheta, isProductTyCon, isDataTyCon, isRecursiveTyCon ) import Class ( Class, classTyCon, classTyVars, classSelIds ) @@ -59,34 +59,35 @@ import PrimOp ( PrimOp(DataToTagOp), primOpSig, mkPrimOpIdName ) import ForeignCall ( ForeignCall ) import DataCon ( DataCon, dataConFieldLabels, dataConRepArity, dataConTyCon, - dataConArgTys, dataConRepType, dataConRepStrictness, + dataConArgTys, dataConRepType, dataConInstOrigArgTys, dataConName, dataConTheta, dataConSig, dataConStrictMarks, dataConId, splitProductType ) import Id ( idType, mkGlobalId, mkVanillaGlobal, mkSysLocal, - mkLocalIdWithInfo, setIdNoDiscard, mkTemplateLocals, mkTemplateLocalsNum, mkTemplateLocal, idNewStrictness, idName ) import IdInfo ( IdInfo, noCafNoTyGenIdInfo, - exactArity, setUnfoldingInfo, setCprInfo, - setArityInfo, setSpecInfo, setCgInfo, + setUnfoldingInfo, + setArityInfo, setSpecInfo, setCgInfo, setCafInfo, mkNewStrictnessInfo, setNewStrictnessInfo, GlobalIdDetails(..), CafInfo(..), CprInfo(..), - CgInfo(..), setCgArity + CgInfo ) import NewDemand ( mkStrictSig, strictSigResInfo, DmdResult(..), - mkTopDmdType, topDmd, evalDmd ) + mkTopDmdType, topDmd, evalDmd, Demand(..), Keepity(..) ) import FieldLabel ( mkFieldLabel, fieldLabelName, firstFieldLabelTag, allFieldLabelTags, fieldLabelType ) +import DmdAnal ( dmdAnalTopRhs ) import CoreSyn import Unique ( mkBuiltinUnique ) import Maybes import PrelNames import Maybe ( isJust ) +import Util ( dropList, isSingleton ) import Outputable import ListSetOps ( assoc, assocMaybe ) import UnicodeUtil ( stringToUtf8 ) @@ -107,8 +108,8 @@ wiredInIds -- -- [The interface file format now carry such information, but there's -- no way yet of expressing at the definition site for these - -- error-reporting - -- functions that they have an 'open' result type. -- sof 1/99] + -- error-reporting functions that they have an 'open' + -- result type. -- sof 1/99] aBSENT_ERROR_ID , eRROR_ID @@ -121,10 +122,13 @@ wiredInIds , rEC_CON_ERROR_ID , rEC_UPD_ERROR_ID - -- These three can't be defined in Haskell + -- These can't be defined in Haskell, but they have + -- perfectly reasonable unfoldings in Core , realWorldPrimId , unsafeCoerceId + , nullAddrId , getTagId + , seqId ] \end{code} @@ -139,16 +143,30 @@ mkDataConId :: Name -> DataCon -> Id -- Makes the *worker* for the data constructor; that is, the function -- that takes the reprsentation arguments and builds the constructor. mkDataConId work_name data_con - = id + = mkGlobalId (DataConId data_con) work_name (dataConRepType data_con) info where - id = mkGlobalId (DataConId data_con) work_name (dataConRepType data_con) info info = noCafNoTyGenIdInfo - `setCgArity` arity `setArityInfo` arity `setNewStrictnessInfo` Just strict_sig - arity = dataConRepArity data_con - strict_sig = mkStrictSig id arity (mkTopDmdType (dataConRepStrictness data_con) cpr_info) + arity = dataConRepArity data_con + + strict_sig = mkStrictSig (mkTopDmdType (replicate arity topDmd) cpr_info) + -- Notice that we do *not* say the worker is strict + -- even if the data constructor is declared strict + -- e.g. data T = MkT !(Int,Int) + -- Why? Because the *wrapper* is strict (and its unfolding has case + -- expresssions that do the evals) but the *worker* itself is not. + -- If we pretend it is strict then when we see + -- case x of y -> $wMkT y + -- the simplifier thinks that y is "sure to be evaluated" (because + -- $wMkT is strict) and drops the case. No, $wMkT is not strict. + -- + -- When the simplifer sees a pattern + -- case e of MkT x -> ... + -- it uses the dataConRepStrictness of MkT to mark x as evaluated; + -- but that's fine... dataConRepStrictness comes from the data con + -- not from the worker Id. tycon = dataConTyCon data_con cpr_info | isProductTyCon tycon && @@ -210,59 +228,64 @@ Notice that \begin{code} mkDataConWrapId data_con - = wrap_id + = mkGlobalId (DataConWrapId data_con) (dataConName data_con) wrap_ty info where - wrap_id = mkGlobalId (DataConWrapId data_con) (dataConName data_con) wrap_ty info work_id = dataConId data_con info = noCafNoTyGenIdInfo - `setUnfoldingInfo` mkTopUnfolding (mkInlineMe wrap_rhs) - `setCgArity` arity + `setUnfoldingInfo` wrap_unf -- The NoCaf-ness is set by noCafNoTyGenIdInfo `setArityInfo` arity -- It's important to specify the arity, so that partial -- applications are treated as values `setNewStrictnessInfo` Just wrap_sig - wrap_ty = mkForAllTys all_tyvars $ - mkFunTys all_arg_tys - result_ty + wrap_ty = mkForAllTys all_tyvars (mkFunTys all_arg_tys result_ty) + wrap_sig = mkStrictSig (mkTopDmdType arg_dmds res_info) res_info = strictSigResInfo (idNewStrictness work_id) - wrap_sig = mkStrictSig wrap_id arity (mkTopDmdType (replicate arity topDmd) res_info) + arg_dmds = [Abs | d <- dict_args] ++ map mk_dmd strict_marks + mk_dmd str | isMarkedStrict str = Eval + | otherwise = Lazy -- The Cpr info can be important inside INLINE rhss, where the - -- wrapper constructor isn't inlined - -- But we are sloppy about the argument demands, because we expect - -- to inline the constructor very vigorously. - - wrap_rhs | isNewTyCon tycon - = ASSERT( null ex_tyvars && null ex_dict_args && length orig_arg_tys == 1 ) + -- wrapper constructor isn't inlined. + -- And the argument strictness can be important too; we + -- may not inline a contructor when it is partially applied. + -- For example: + -- data W = C !Int !Int !Int + -- ...(let w = C x in ...(w p q)...)... + -- we want to see that w is strict in its two arguments + + wrap_unf | isNewTyCon tycon + = ASSERT( null ex_tyvars && null ex_dict_args && isSingleton orig_arg_tys ) -- No existentials on a newtype, but it can have a context -- e.g. newtype Eq a => T a = MkT (...) + mkTopUnfolding $ Note InlineMe $ mkLams tyvars $ mkLams dict_args $ Lam id_arg1 $ - mkNewTypeBody tycon result_ty id_arg1 + mkNewTypeBody tycon result_ty (Var id_arg1) | null dict_args && not (any isMarkedStrict strict_marks) - = Var work_id -- The common case. Not only is this efficient, - -- but it also ensures that the wrapper is replaced - -- by the worker even when there are no args. - -- f (:) x - -- becomes - -- f $w: x - -- This is really important in rule matching, - -- (We could match on the wrappers, - -- but that makes it less likely that rules will match - -- when we bring bits of unfoldings together.) + = mkCompulsoryUnfolding (Var work_id) + -- The common case. Not only is this efficient, + -- but it also ensures that the wrapper is replaced + -- by the worker even when there are no args. + -- f (:) x + -- becomes + -- f $w: x + -- This is really important in rule matching, + -- (We could match on the wrappers, + -- but that makes it less likely that rules will match + -- when we bring bits of unfoldings together.) -- -- NB: because of this special case, (map (:) ys) turns into - -- (map $w: ys), and thence into (map (\x xs. $w: x xs) ys) - -- in core-to-stg. The top-level defn for (:) is never used. + -- (map $w: ys). The top-level defn for (:) is never used. -- This is somewhat of a bore, but I'm currently leaving it -- as is, so that there still is a top level curried (:) for -- the interpreter to call. | otherwise - = mkLams all_tyvars $ mkLams dict_args $ + = mkTopUnfolding $ Note InlineMe $ + mkLams all_tyvars $ mkLams dict_args $ mkLams ex_dict_args $ mkLams id_args $ foldr mk_case con_app (zip (ex_dict_args++id_args) strict_marks) i3 [] @@ -412,13 +435,16 @@ mkRecordSelId tycon field_label unpack_id unpackUtf8_id mkFunTy data_ty field_tau arity = 1 + n_dict_tys + n_field_dict_tys - info = noCafNoTyGenIdInfo - `setCgInfo` (CgInfo arity caf_info) - `setArityInfo` arity - `setUnfoldingInfo` unfolding - -- ToDo: consider adding further IdInfo - unfolding = mkTopUnfolding sel_rhs + (strict_sig, rhs_w_str) = dmdAnalTopRhs sel_rhs + -- Use the demand analyser to work out strictness. + -- With all this unpackery it's not easy! + + info = noCafNoTyGenIdInfo + `setCafInfo` caf_info + `setArityInfo` arity + `setUnfoldingInfo` mkTopUnfolding rhs_w_str + `setNewStrictnessInfo` Just strict_sig -- Allocate Ids. We do it a funny way round because field_dict_tys is -- almost always empty. Also note that we use length_tycon_theta @@ -447,15 +473,23 @@ mkRecordSelId tycon field_label unpack_id unpackUtf8_id mkLams dict_ids $ mkLams field_dict_ids $ Lam data_id $ sel_body - sel_body | isNewTyCon tycon = mkNewTypeBody tycon field_tau data_id + sel_body | isNewTyCon tycon = mkNewTypeBody tycon field_tau (mk_result data_id) | otherwise = Case (Var data_id) data_id (default_alt ++ the_alts) + mk_result result_id = mkVarApps (mkVarApps (Var result_id) field_tyvars) field_dict_ids + -- We pull the field lambdas to the top, so we need to + -- apply them in the body. For example: + -- data T = MkT { foo :: forall a. a->a } + -- + -- foo :: forall a. T -> a -> a + -- foo = /\a. \t:T. case t of { MkT f -> f a } + mk_maybe_alt data_con = case maybe_the_arg_id of Nothing -> Nothing Just the_arg_id -> Just (DataAlt data_con, real_args, mkLets binds body) where - body = mkVarApps (mkVarApps (Var the_arg_id) field_tyvars) field_dict_ids + body = mk_result the_arg_id strict_marks = dataConStrictMarks data_con (binds, real_args) = rebuildConArgs arg_ids strict_marks (map mkBuiltinUnique [unpack_base..]) @@ -514,7 +548,7 @@ rebuildConArgs (arg:args) (str:stricts) us = splitProductType "rebuildConArgs" arg_ty unpacked_args = zipWith (mkSysLocal SLIT("rb")) us con_arg_tys - (binds, args') = rebuildConArgs args stricts (drop (length con_arg_tys) us) + (binds, args') = rebuildConArgs args stricts (dropList con_arg_tys us) con_app = mkConApp pack_con (map Type tycon_args ++ map Var unpacked_args) in (NonRec arg con_app : binds, unpacked_args ++ args') @@ -552,14 +586,21 @@ mkDictSelId name clas tag = assoc "MkId.mkDictSelId" (map idName (classSelIds clas) `zip` allFieldLabelTags) name info = noCafNoTyGenIdInfo - `setCgArity` 1 - `setArityInfo` 1 - `setUnfoldingInfo` unfolding - + `setArityInfo` 1 + `setUnfoldingInfo` mkTopUnfolding rhs + `setNewStrictnessInfo` Just strict_sig + -- We no longer use 'must-inline' on record selectors. They'll -- inline like crazy if they scrutinise a constructor - unfolding = mkTopUnfolding rhs + -- The strictness signature is of the form U(AAAVAAAA) -> T + -- where the V depends on which item we are selecting + -- It's worth giving one, so that absence info etc is generated + -- even if the selector isn't inlined + strict_sig = mkStrictSig (mkTopDmdType [arg_dmd] TopRes) + arg_dmd | isNewTyCon tycon = Eval + | otherwise = Seq Drop [ if the_arg_id == id then Eval else Abs + | id <- arg_ids ] tyvars = classTyVars clas @@ -573,16 +614,18 @@ mkDictSelId name clas (dict_id:arg_ids) = mkTemplateLocals (mkPredTy pred : arg_tys) rhs | isNewTyCon tycon = mkLams tyvars $ Lam dict_id $ - mkNewTypeBody tycon (head arg_tys) dict_id + mkNewTypeBody tycon (head arg_tys) (Var dict_id) | otherwise = mkLams tyvars $ Lam dict_id $ Case (Var dict_id) dict_id [(DataAlt data_con, arg_ids, Var the_arg_id)] -mkNewTypeBody tycon result_ty result_id +mkNewTypeBody tycon result_ty result_expr + -- Adds a coerce where necessary + -- Used for both wrapping and unwrapping | isRecursiveTyCon tycon -- Recursive case; use a coerce - = Note (Coerce result_ty (idType result_id)) (Var result_id) + = Note (Coerce result_ty (exprType result_expr)) result_expr | otherwise -- Normal case - = Var result_id + = result_expr \end{code} @@ -604,13 +647,11 @@ mkPrimOpId prim_op info = noCafNoTyGenIdInfo `setSpecInfo` rules - `setCgArity` arity `setArityInfo` arity `setNewStrictnessInfo` Just (mkNewStrictnessInfo id arity strict_info NoCPRInfo) -- Until we modify the primop generation code - rules = maybe emptyCoreRules (addRule emptyCoreRules id) - (primOpRule prim_op) + rules = foldl (addRule id) emptyCoreRules (primOpRules prim_op) -- For each ccall we manufacture a separate CCallOpId, giving it @@ -627,9 +668,8 @@ mkFCallId uniq fcall ty = ASSERT( isEmptyVarSet (tyVarsOfType ty) ) -- A CCallOpId should have no free type variables; -- when doing substitutions won't substitute over it - id + mkGlobalId (FCallId fcall) name ty info where - id = mkGlobalId (FCallId fcall) name ty info occ_str = showSDocIface (braces (ppr fcall <+> ppr ty)) -- The "occurrence name" of a ccall is the full info about the -- ccall; it is encoded, but may have embedded spaces etc! @@ -637,14 +677,13 @@ mkFCallId uniq fcall ty name = mkFCallName uniq occ_str info = noCafNoTyGenIdInfo - `setCgArity` arity `setArityInfo` arity `setNewStrictnessInfo` Just strict_sig (_, tau) = tcSplitForAllTys ty (arg_tys, _) = tcSplitFunTys tau arity = length arg_tys - strict_sig = mkStrictSig id arity (mkTopDmdType (replicate arity evalDmd) TopRes) + strict_sig = mkStrictSig (mkTopDmdType (replicate arity evalDmd) TopRes) \end{code} @@ -654,9 +693,34 @@ mkFCallId uniq fcall ty %* * %************************************************************************ +Important notes about dict funs and default methods +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Dict funs and default methods are *not* ImplicitIds. Their definition +involves user-written code, so we can't figure out their strictness etc +based on fixed info, as we can for constructors and record selectors (say). + +We build them as GlobalIds, but when in the module where they are +bound, we turn the Id at the *binding site* into an exported LocalId. +This ensures that they are taken to account by free-variable finding +and dependency analysis (e.g. CoreFVs.exprFreeVars). The simplifier +will propagate the LocalId to all occurrence sites. + +Why shouldn't they be bound as GlobalIds? Because, in particular, if +they are globals, the specialiser floats dict uses above their defns, +which prevents good simplifications happening. Also the strictness +analyser treats a occurrence of a GlobalId as imported and assumes it +contains strictness in its IdInfo, which isn't true if the thing is +bound in the same module as the occurrence. + +It's OK for dfuns to be LocalIds, because we form the instance-env to +pass on to the next module (md_insts) in CoreTidy, afer tidying +and globalising the top-level Ids. + +BUT make sure they are *exported* LocalIds (setIdLocalExported) so +that they aren't discarded by the occurrence analyser. + \begin{code} -mkDefaultMethodId dm_name ty - = mkVanillaGlobal dm_name ty noCafNoTyGenIdInfo +mkDefaultMethodId dm_name ty = mkVanillaGlobal dm_name ty noCafNoTyGenIdInfo mkDictFunId :: Name -- Name to use for the dict fun; -> Class @@ -666,19 +730,7 @@ mkDictFunId :: Name -- Name to use for the dict fun; -> Id mkDictFunId dfun_name clas inst_tyvars inst_tys dfun_theta - = setIdNoDiscard (mkLocalIdWithInfo dfun_name dfun_ty noCafNoTyGenIdInfo) - -- NB: It's important that dict funs are *local* Ids - -- This ensures that they are taken to account by free-variable finding - -- and dependency analysis (e.g. CoreFVs.exprFreeVars). - -- In particular, if they are globals, the - -- specialiser floats dict uses above their defns, which prevents - -- good simplifications happening. - -- - -- It's OK for them to be locals, because we form the instance-env to - -- pass on to the next module (md_insts) in CoreTidy, afer tdying - -- and globalising the top-level Ids. - -- - -- BUT Make sure it's an exported Id (setIdNoDiscard) so that it's not dropped! + = mkVanillaGlobal dfun_name dfun_ty noCafNoTyGenIdInfo where dfun_ty = mkSigmaTy inst_tyvars dfun_theta (mkDictTy clas inst_tys) @@ -718,7 +770,12 @@ mkDictFunId dfun_name clas inst_tyvars inst_tys dfun_theta %* * %************************************************************************ -These two can't be defined in Haskell. +These Ids can't be defined in Haskell. They could be defined in +unfoldings in PrelGHC.hi-boot, but we'd have to ensure that they +were definitely, definitely inlined, because there is no curried +identifier for them. That's what mkCompulsoryUnfolding does. +If we had a way to get a compulsory unfolding from an interface file, +we could do that, but we don't right now. unsafeCoerce# isn't so much a PrimOp as a phantom identifier, that just gets expanded into a type coercion wherever it occurs. Hence we @@ -729,6 +786,7 @@ they can unify with both unlifted and lifted types. Hence we provide another gun with which to shoot yourself in the foot. \begin{code} +-- unsafeCoerce# :: forall a b. a -> b unsafeCoerceId = pcMiscPrelId unsafeCoerceIdKey pREL_GHC SLIT("unsafeCoerce#") ty info where @@ -740,8 +798,27 @@ unsafeCoerceId [x] = mkTemplateLocals [openAlphaTy] rhs = mkLams [openAlphaTyVar,openBetaTyVar,x] $ Note (Coerce openBetaTy openAlphaTy) (Var x) -\end{code} +-- nullAddr# :: Addr# +-- The reason is is here is because we don't provide +-- a way to write this literal in Haskell. +nullAddrId + = pcMiscPrelId nullAddrIdKey pREL_GHC SLIT("nullAddr#") addrPrimTy info + where + info = noCafNoTyGenIdInfo `setUnfoldingInfo` + mkCompulsoryUnfolding (Lit nullAddrLit) + +seqId + = pcMiscPrelId seqIdKey pREL_GHC SLIT("seq") ty info + where + info = noCafNoTyGenIdInfo `setUnfoldingInfo` mkCompulsoryUnfolding rhs + + + ty = mkForAllTys [alphaTyVar,betaTyVar] + (mkFunTy alphaTy (mkFunTy betaTy betaTy)) + [x,y] = mkTemplateLocals [alphaTy, betaTy] + rhs = mkLams [alphaTyVar,betaTyVar,x,y] (Case (Var x) x [(DEFAULT, [], Var y)]) +\end{code} @getTag#@ is another function which can't be defined in Haskell. It needs to evaluate its argument and call the dataToTag# primitive. @@ -849,11 +926,9 @@ pcMiscPrelId key mod str ty info -- will be in "the right place" to be in scope. pc_bottoming_Id key mod name ty - = id + = pcMiscPrelId key mod name ty bottoming_info where - id = pcMiscPrelId key mod name ty bottoming_info - arity = 1 - strict_sig = mkStrictSig id arity (mkTopDmdType [evalDmd] BotRes) + strict_sig = mkStrictSig (mkTopDmdType [evalDmd] BotRes) bottoming_info = noCafNoTyGenIdInfo `setNewStrictnessInfo` Just strict_sig -- these "bottom" out, no matter what their arguments