lower levels it is preserved with @let@/@letrec@s).
\begin{code}
-module DsBinds ( dsMonoBinds ) where
+module DsBinds ( dsTopLHsBinds, dsLHsBinds, decomposeRuleLhs,
+ dsCoercion,
+ AutoScc(..)
+ ) where
#include "HsVersions.h"
-import {-# SOURCE #-} DsExpr( dsExpr )
+import {-# SOURCE #-} DsExpr( dsLExpr, dsExpr )
+import {-# SOURCE #-} Match( matchWrapper )
-import HsSyn -- lots of things
-import CoreSyn -- lots of things
-import CoreUtils ( coreExprType )
-import TcHsSyn ( TypecheckedMonoBinds )
import DsMonad
import DsGRHSs ( dsGuarded )
import DsUtils
-import Match ( matchWrapper )
-
-import BasicTypes ( RecFlag(..) )
-import CmdLineOpts ( opt_SccProfilingOn, opt_AutoSccsOnAllToplevs,
- opt_AutoSccsOnExportedToplevs
- )
-import CostCentre ( mkAutoCC, IsCafCC(..), mkAllDictsCC )
-import Id ( idType, Id )
+
+import HsSyn -- lots of things
+import CoreSyn -- lots of things
+import CoreUtils ( exprType, mkInlineMe, mkSCC )
+
+import StaticFlags ( opt_AutoSccsOnAllToplevs,
+ opt_AutoSccsOnExportedToplevs )
+import OccurAnal ( occurAnalyseExpr )
+import CostCentre ( mkAutoCC, IsCafCC(..) )
+import Id ( Id, DictId, idType, idName, isExportedId, mkLocalId, setInlinePragma )
+import Rules ( addIdSpecialisations, mkLocalRule )
+import Var ( TyVar, Var, isGlobalId, setIdNotExported )
import VarEnv
-import Name ( isExported )
-import Type ( mkTyVarTy, isDictTy, substTy
- )
+import Type ( mkTyVarTy, substTyWith )
import TysWiredIn ( voidTy )
import Outputable
+import SrcLoc ( Located(..) )
+import Maybes ( isJust, catMaybes, orElse )
+import Bag ( bagToList )
+import BasicTypes ( Activation(..), InlineSpec(..), isAlwaysActive, defaultInlineSpec )
+import Monad ( foldM )
+import FastString ( mkFastString )
+import List ( (\\) )
+import Util ( mapSnd )
\end{code}
%************************************************************************
%************************************************************************
\begin{code}
-dsMonoBinds :: Bool -- False => don't (auto-)annotate scc on toplevs.
- -> TypecheckedMonoBinds
- -> [(Id,CoreExpr)] -- Put this on the end (avoid quadratic append)
- -> DsM [(Id,CoreExpr)] -- Result
+dsTopLHsBinds :: AutoScc -> LHsBinds Id -> DsM [(Id,CoreExpr)]
+dsTopLHsBinds auto_scc binds = ds_lhs_binds auto_scc binds
+
+dsLHsBinds :: LHsBinds Id -> DsM [(Id,CoreExpr)]
+dsLHsBinds binds = ds_lhs_binds NoSccs binds
+
-dsMonoBinds _ EmptyMonoBinds rest = returnDs rest
+------------------------
+ds_lhs_binds :: AutoScc -> LHsBinds Id -> DsM [(Id,CoreExpr)]
+ -- scc annotation policy (see below)
+ds_lhs_binds auto_scc binds = foldM (dsLHsBind auto_scc) [] (bagToList binds)
-dsMonoBinds auto_scc (AndMonoBinds binds_1 binds_2) rest
- = dsMonoBinds auto_scc binds_2 rest `thenDs` \ rest' ->
- dsMonoBinds auto_scc binds_1 rest'
+dsLHsBind :: AutoScc
+ -> [(Id,CoreExpr)] -- Put this on the end (avoid quadratic append)
+ -> LHsBind Id
+ -> DsM [(Id,CoreExpr)] -- Result
+dsLHsBind auto_scc rest (L loc bind)
+ = putSrcSpanDs loc $ dsHsBind auto_scc rest bind
-dsMonoBinds _ (CoreMonoBind var core_expr) rest
- = returnDs ((var, core_expr) : rest)
+dsHsBind :: AutoScc
+ -> [(Id,CoreExpr)] -- Put this on the end (avoid quadratic append)
+ -> HsBind Id
+ -> DsM [(Id,CoreExpr)] -- Result
-dsMonoBinds _ (VarMonoBind var expr) rest
- = dsExpr expr `thenDs` \ core_expr ->
+dsHsBind auto_scc rest (VarBind var expr)
+ = dsLExpr expr `thenDs` \ core_expr ->
-- Dictionary bindings are always VarMonoBinds, so
-- we only need do this here
addDictScc var core_expr `thenDs` \ core_expr' ->
-
returnDs ((var, core_expr') : rest)
-dsMonoBinds auto_scc (FunMonoBind fun _ matches locn) rest
- = putSrcLocDs locn $
- matchWrapper (FunMatch fun) matches error_string `thenDs` \ (args, body) ->
- addAutoScc auto_scc (fun, mkLams args body) `thenDs` \ pair ->
+dsHsBind auto_scc rest (FunBind { fun_id = L _ fun, fun_matches = matches, fun_co_fn = co_fn })
+ = matchWrapper (FunRhs (idName fun)) matches `thenDs` \ (args, body) ->
+ dsCoercion co_fn (return (mkLams args body)) `thenDs` \ rhs ->
+ addAutoScc auto_scc (fun, rhs) `thenDs` \ pair ->
returnDs (pair : rest)
- where
- error_string = "function " ++ showSDoc (ppr fun)
-dsMonoBinds _ (PatMonoBind pat grhss locn) rest
- = putSrcLocDs locn $
- dsGuarded grhss `thenDs` \ body_expr ->
- mkSelectorBinds pat body_expr `thenDs` \ sel_binds ->
+dsHsBind auto_scc rest (PatBind { pat_lhs = pat, pat_rhs = grhss, pat_rhs_ty = ty })
+ = dsGuarded grhss ty `thenDs` \ body_expr ->
+ mkSelectorBinds pat body_expr `thenDs` \ sel_binds ->
+ mappM (addAutoScc auto_scc) sel_binds `thenDs` \ sel_binds ->
returnDs (sel_binds ++ rest)
-- Common special case: no type or dictionary abstraction
-dsMonoBinds auto_scc (AbsBinds [] [] exports binds) rest
- = mapDs (addAutoScc auto_scc) [(global, Var local) | (_, global, local) <- exports] `thenDs` \ exports' ->
- dsMonoBinds False binds (exports' ++ rest)
+ -- For the (rare) case when there are some mixed-up
+ -- dictionary bindings (for which a Rec is convenient)
+ -- we reply on the enclosing dsBind to wrap a Rec around.
+dsHsBind auto_scc rest (AbsBinds [] [] exports binds)
+ = ds_lhs_binds (addSccs auto_scc exports) binds `thenDs` \ core_prs ->
+ let
+ core_prs' = addLocalInlines exports core_prs
+ exports' = [(global, Var local) | (_, global, local, _) <- exports]
+ in
+ returnDs (core_prs' ++ exports' ++ rest)
-- Another common case: one exported variable
- -- All non-recursive bindings come through this way
-dsMonoBinds auto_scc (AbsBinds all_tyvars dicts [(tyvars, global, local)] binds) rest
+ -- Non-recursive bindings come through this way
+dsHsBind auto_scc rest
+ (AbsBinds all_tyvars dicts exports@[(tyvars, global, local, prags)] binds)
= ASSERT( all (`elem` tyvars) all_tyvars )
- dsMonoBinds False binds [] `thenDs` \ core_prs ->
+ ds_lhs_binds (addSccs auto_scc exports) binds `thenDs` \ core_prs ->
let
-- Always treat the binds as recursive, because the typechecker
-- makes rather mixed-up dictionary bindings
- core_binds = [Rec core_prs]
+ core_bind = Rec core_prs
in
- addAutoScc auto_scc (global, mkLams tyvars $ mkLams dicts $
- mkLets core_binds (Var local)) `thenDs` \ global' ->
- returnDs (global' : rest)
+ mappM (dsSpec all_tyvars dicts tyvars global local core_bind)
+ prags `thenDs` \ mb_specs ->
+ let
+ (spec_binds, rules) = unzip (catMaybes mb_specs)
+ global' = addIdSpecialisations global rules
+ rhs' = mkLams tyvars $ mkLams dicts $ Let core_bind (Var local)
+ inl = case [inl | InlinePrag inl <- prags] of
+ [] -> defaultInlineSpec
+ (inl:_) -> inl
+ in
+ returnDs (addInlineInfo inl global' rhs' : spec_binds ++ rest)
-dsMonoBinds auto_scc (AbsBinds all_tyvars dicts exports binds) rest
- = dsMonoBinds False binds [] `thenDs` \ core_prs ->
- let
- core_binds = [Rec core_prs]
+dsHsBind auto_scc rest (AbsBinds all_tyvars dicts exports binds)
+ = ds_lhs_binds (addSccs auto_scc exports) binds `thenDs` \ core_prs ->
+ let
+ -- Rec because of mixed-up dictionary bindings
+ core_bind = Rec (addLocalInlines exports core_prs)
tup_expr = mkTupleExpr locals
- tup_ty = coreExprType tup_expr
+ tup_ty = exprType tup_expr
poly_tup_expr = mkLams all_tyvars $ mkLams dicts $
- mkLets core_binds tup_expr
- locals = [local | (_, _, local) <- exports]
+ Let core_bind tup_expr
+ locals = [local | (_, _, local, _) <- exports]
local_tys = map idType locals
in
- newSysLocalDs (coreExprType poly_tup_expr) `thenDs` \ poly_tup_id ->
+ newSysLocalDs (exprType poly_tup_expr) `thenDs` \ poly_tup_id ->
let
dict_args = map Var dicts
- mk_bind (tyvars, global, local) n -- locals !! n == local
+ mk_bind ((tyvars, global, local, prags), n) -- locals !! n == local
= -- Need to make fresh locals to bind in the selector, because
-- some of the tyvars will be bound to voidTy
- newSysLocalsDs (map (substTy env) local_tys) `thenDs` \ locals' ->
- newSysLocalDs (substTy env tup_ty) `thenDs` \ tup_id ->
- addAutoScc auto_scc
- (global, mkLams tyvars $ mkLams dicts $
- mkTupleSelector locals' (locals' !! n) tup_id $
- mkApps (mkTyApps (Var poly_tup_id) ty_args) dict_args)
+ newSysLocalsDs (map substitute local_tys) `thenDs` \ locals' ->
+ newSysLocalDs (substitute tup_ty) `thenDs` \ tup_id ->
+ mapM (dsSpec all_tyvars dicts tyvars global local core_bind)
+ prags `thenDs` \ mb_specs ->
+ let
+ (spec_binds, rules) = unzip (catMaybes mb_specs)
+ global' = addIdSpecialisations global rules
+ rhs = mkLams tyvars $ mkLams dicts $
+ mkTupleSelector locals' (locals' !! n) tup_id $
+ mkApps (mkTyApps (Var poly_tup_id) ty_args) dict_args
+ in
+ returnDs ((global', rhs) : spec_binds)
where
mk_ty_arg all_tyvar | all_tyvar `elem` tyvars = mkTyVarTy all_tyvar
| otherwise = voidTy
- ty_args = map mk_ty_arg all_tyvars
- env = all_tyvars `zipVarEnv` ty_args
+ ty_args = map mk_ty_arg all_tyvars
+ substitute = substTyWith all_tyvars ty_args
in
- zipWithDs mk_bind exports [0..] `thenDs` \ export_binds ->
+ mappM mk_bind (exports `zip` [0..]) `thenDs` \ export_binds_s ->
-- don't scc (auto-)annotate the tuple itself.
- returnDs ((poly_tup_id, poly_tup_expr) : (export_binds ++ rest))
+
+ returnDs ((poly_tup_id, poly_tup_expr) : (concat export_binds_s ++ rest))
+
+dsSpec :: [TyVar] -> [DictId] -> [TyVar]
+ -> Id -> Id -- Global, local
+ -> CoreBind -> Prag
+ -> DsM (Maybe ((Id,CoreExpr), -- Binding for specialised Id
+ CoreRule)) -- Rule for the Global Id
+
+-- Example:
+-- f :: (Eq a, Ix b) => a -> b -> b
+-- {-# SPECIALISE f :: Ix b => Int -> b -> b #-}
+--
+-- AbsBinds [ab] [d1,d2] [([ab], f, f_mono, prags)] binds
+--
+-- SpecPrag (/\b.\(d:Ix b). f Int b dInt d)
+-- (forall b. Ix b => Int -> b -> b)
+--
+-- Rule: forall b,(d:Ix b). f Int b dInt d = f_spec b d
+--
+-- Spec bind: f_spec = Let f = /\ab \(d1:Eq a)(d2:Ix b). let binds in f_mono
+-- /\b.\(d:Ix b). in f Int b dInt d
+-- The idea is that f occurs just once, so it'll be
+-- inlined and specialised
+
+dsSpec all_tvs dicts tvs poly_id mono_id mono_bind (InlinePrag {})
+ = return Nothing
+
+dsSpec all_tvs dicts tvs poly_id mono_id mono_bind
+ (SpecPrag spec_expr spec_ty const_dicts inl)
+ = do { let poly_name = idName poly_id
+ ; spec_name <- newLocalName poly_name
+ ; ds_spec_expr <- dsExpr spec_expr
+ ; let (bndrs, body) = collectBinders ds_spec_expr
+ mb_lhs = decomposeRuleLhs (bndrs ++ const_dicts) body
+
+ ; case mb_lhs of
+ Nothing -> do { dsWarn msg; return Nothing }
+
+ Just (bndrs', var, args) -> return (Just (addInlineInfo inl spec_id spec_rhs, rule))
+ where
+ local_poly = setIdNotExported poly_id
+ -- Very important to make the 'f' non-exported,
+ -- else it won't be inlined!
+ spec_id = mkLocalId spec_name spec_ty
+ spec_rhs = Let (NonRec local_poly poly_f_body) ds_spec_expr
+ poly_f_body = mkLams (tvs ++ dicts) $
+ fix_up (Let mono_bind (Var mono_id))
+
+ -- Quantify over constant dicts on the LHS, since
+ -- their value depends only on their type
+ -- The ones we are interested in may even be imported
+ -- e.g. GHC.Base.dEqInt
+
+ rule = mkLocalRule (mkFastString ("SPEC " ++ showSDoc (ppr poly_name)))
+ AlwaysActive poly_name
+ bndrs' -- Includes constant dicts
+ args
+ (mkVarApps (Var spec_id) bndrs)
+ }
+ where
+ -- Bind to voidTy any of all_ptvs that aren't
+ -- relevant for this particular function
+ fix_up body | null void_tvs = body
+ | otherwise = mkTyApps (mkLams void_tvs body)
+ (map (const voidTy) void_tvs)
+ void_tvs = all_tvs \\ tvs
+
+ msg = hang (ptext SLIT("Specialisation too complicated to desugar; ignored"))
+ 2 (ppr spec_expr)
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsection{Adding inline pragmas}
+%* *
+%************************************************************************
+
+\begin{code}
+decomposeRuleLhs :: [Var] -> CoreExpr -> Maybe ([Var], Id, [CoreExpr])
+-- Returns Nothing if the LHS isn't of the expected shape
+-- The argument 'all_bndrs' includes the "constant dicts" of the LHS,
+-- and they may be GlobalIds, which we can't forall-ify.
+-- So we substitute them out instead
+decomposeRuleLhs all_bndrs lhs
+ = go init_env (occurAnalyseExpr lhs) -- Occurrence analysis sorts out the dict
+ -- bindings so we know if they are recursive
+ where
+
+ -- all_bndrs may include top-level imported dicts,
+ -- imported things with a for-all.
+ -- So we localise them and subtitute them out
+ bndr_prs = [ (id, Var (localise id)) | id <- all_bndrs, isGlobalId id ]
+ localise d = mkLocalId (idName d) (idType d)
+
+ init_env = mkVarEnv bndr_prs
+ all_bndrs' = map subst_bndr all_bndrs
+ subst_bndr bndr = case lookupVarEnv init_env bndr of
+ Just (Var bndr') -> bndr'
+ Just other -> panic "decomposeRuleLhs"
+ Nothing -> bndr
+
+ -- Substitute dicts in the LHS args, so that there
+ -- aren't any lets getting in the way
+ -- Note that we substitute the function too; we might have this as
+ -- a LHS: let f71 = M.f Int in f71
+ go env (Let (NonRec dict rhs) body)
+ = go (extendVarEnv env dict (simpleSubst env rhs)) body
+ go env body
+ = case collectArgs (simpleSubst env body) of
+ (Var fn, args) -> Just (all_bndrs', fn, args)
+ other -> Nothing
+
+simpleSubst :: IdEnv CoreExpr -> CoreExpr -> CoreExpr
+-- Similar to CoreSubst.substExpr, except that
+-- (a) takes no account of capture; dictionary bindings use new names
+-- (b) can have a GlobalId (imported) in its domain
+-- (c) Ids only; no types are substituted
+
+simpleSubst subst expr
+ = go expr
+ where
+ go (Var v) = lookupVarEnv subst v `orElse` Var v
+ go (Type ty) = Type ty
+ go (Lit lit) = Lit lit
+ go (App fun arg) = App (go fun) (go arg)
+ go (Note note e) = Note note (go e)
+ go (Lam bndr body) = Lam bndr (go body)
+ go (Let (NonRec bndr rhs) body) = Let (NonRec bndr (go rhs)) (go body)
+ go (Let (Rec pairs) body) = Let (Rec (mapSnd go pairs)) (go body)
+ go (Case scrut bndr ty alts) = Case (go scrut) bndr ty
+ [(c,bs,go r) | (c,bs,r) <- alts]
+
+addLocalInlines exports core_prs
+ = map add_inline core_prs
+ where
+ add_inline (bndr,rhs) | Just inl <- lookupVarEnv inline_env bndr
+ = addInlineInfo inl bndr rhs
+ | otherwise
+ = (bndr,rhs)
+ inline_env = mkVarEnv [(mono_id, prag)
+ | (_, _, mono_id, prags) <- exports,
+ InlinePrag prag <- prags]
+
+addInlineInfo :: InlineSpec -> Id -> CoreExpr -> (Id,CoreExpr)
+addInlineInfo (Inline phase is_inline) bndr rhs
+ = (attach_phase bndr phase, wrap_inline is_inline rhs)
+ where
+ attach_phase bndr phase
+ | isAlwaysActive phase = bndr -- Default phase
+ | otherwise = bndr `setInlinePragma` phase
+
+ wrap_inline True body = mkInlineMe body
+ wrap_inline False body = body
\end{code}
%************************************************************************
\begin{code}
-addAutoScc :: Bool -- if needs be, decorate toplevs?
+data AutoScc
+ = TopLevel
+ | TopLevelAddSccs (Id -> Maybe Id)
+ | NoSccs
+
+addSccs :: AutoScc -> [(a,Id,Id,[Prag])] -> AutoScc
+addSccs auto_scc@(TopLevelAddSccs _) exports = auto_scc
+addSccs NoSccs exports = NoSccs
+addSccs TopLevel exports
+ = TopLevelAddSccs (\id -> case [ exp | (_,exp,loc,_) <- exports, loc == id ] of
+ (exp:_) | opt_AutoSccsOnAllToplevs ||
+ (isExportedId exp &&
+ opt_AutoSccsOnExportedToplevs)
+ -> Just exp
+ _ -> Nothing)
+
+addAutoScc :: AutoScc -- if needs be, decorate toplevs?
-> (Id, CoreExpr)
-> DsM (Id, CoreExpr)
-addAutoScc auto_scc_candidate pair@(bndr, core_expr)
- | auto_scc_candidate && worthSCC core_expr &&
- (opt_AutoSccsOnAllToplevs || (isExported bndr && opt_AutoSccsOnExportedToplevs))
- = getModuleAndGroupDs `thenDs` \ (mod,grp) ->
- returnDs (bndr, Note (SCC (mkAutoCC bndr mod grp NotCafCC)) core_expr)
- | otherwise
- = returnDs pair
+addAutoScc (TopLevelAddSccs auto_scc_fn) pair@(bndr, core_expr)
+ | do_auto_scc
+ = getModuleDs `thenDs` \ mod ->
+ returnDs (bndr, mkSCC (mkAutoCC top_bndr mod NotCafCC) core_expr)
+ where do_auto_scc = isJust maybe_auto_scc
+ maybe_auto_scc = auto_scc_fn bndr
+ (Just top_bndr) = maybe_auto_scc
-worthSCC (Note (SCC _) _) = False
-worthSCC (Con _ _) = False
-worthSCC core_expr = True
+addAutoScc _ pair
+ = returnDs pair
\end{code}
-If profiling and dealing with a dict binding, wrap the dict in "_scc_ DICT <dict>":
+If profiling and dealing with a dict binding,
+wrap the dict in @_scc_ DICT <dict>@:
\begin{code}
-addDictScc var rhs
- | not ( opt_SccProfilingOn || opt_AutoSccsOnAllToplevs)
- -- the latter is so that -unprof-auto-scc-all adds dict sccs
- || not (isDictTy (idType var))
+addDictScc var rhs = returnDs rhs
+
+{- DISABLED for now (need to somehow make up a name for the scc) -- SDM
+ | not ( opt_SccProfilingOn && opt_AutoSccsOnDicts)
+ || not (isDictId var)
= returnDs rhs -- That's easy: do nothing
| otherwise
= getModuleAndGroupDs `thenDs` \ (mod, grp) ->
-
-- ToDo: do -dicts-all flag (mark dict things with individual CCs)
returnDs (Note (SCC (mkAllDictsCC mod grp False)) rhs)
+-}
+\end{code}
+
+
+%************************************************************************
+%* *
+ Desugaring coercions
+%* *
+%************************************************************************
+
+
+\begin{code}
+dsCoercion :: ExprCoFn -> DsM CoreExpr -> DsM CoreExpr
+dsCoercion CoHole thing_inside = thing_inside
+dsCoercion (CoCompose c1 c2) thing_inside = dsCoercion c1 (dsCoercion c2 thing_inside)
+dsCoercion (CoLams ids c) thing_inside = do { expr <- dsCoercion c thing_inside
+ ; return (mkLams ids expr) }
+dsCoercion (CoTyLams tvs c) thing_inside = do { expr <- dsCoercion c thing_inside
+ ; return (mkLams tvs expr) }
+dsCoercion (CoApps c ids) thing_inside = do { expr <- dsCoercion c thing_inside
+ ; return (mkVarApps expr ids) }
+dsCoercion (CoTyApps c tys) thing_inside = do { expr <- dsCoercion c thing_inside
+ ; return (mkTyApps expr tys) }
+dsCoercion (CoLet bs c) thing_inside = do { prs <- dsLHsBinds bs
+ ; expr <- dsCoercion c thing_inside
+ ; return (Let (Rec prs) expr) }
\end{code}
+
+
projects / ghc-hetmet.git / blobdiff