lower levels it is preserved with @let@/@letrec@s).
\begin{code}
-module DsBinds ( dsTopLHsBinds, dsLHsBinds, decomposeRuleLhs,
+module DsBinds ( dsTopLHsBinds, dsLHsBinds, decomposeRuleLhs, dsSpec,
dsHsWrapper, dsTcEvBinds, dsEvBinds, wrapDsEvBinds,
DsEvBind(..), AutoScc(..)
) where
%************************************************************************
\begin{code}
-dsTopLHsBinds :: AutoScc -> LHsBinds Id -> DsM [(Id,CoreExpr)]
-dsTopLHsBinds auto_scc binds = do { binds' <- ds_lhs_binds auto_scc binds
- ; return (fromOL binds') }
+dsTopLHsBinds :: AutoScc -> LHsBinds Id -> DsM (OrdList (Id,CoreExpr))
+dsTopLHsBinds auto_scc binds = ds_lhs_binds auto_scc binds
dsLHsBinds :: LHsBinds Id -> DsM [(Id,CoreExpr)]
dsLHsBinds binds = do { binds' <- ds_lhs_binds NoSccs binds
= do { (args, body) <- matchWrapper (FunRhs (idName fun) inf) matches
; body' <- mkOptTickBox tick body
; wrap_fn' <- dsHsWrapper co_fn
- ; return (unitOL (fun, wrap_fn' (mkLams args body'))) }
+ ; let rhs = wrap_fn' (mkLams args body')
+ ; return (unitOL (makeCorePair fun False 0 rhs)) }
dsHsBind _ (PatBind { pat_lhs = pat, pat_rhs = grhss, pat_rhs_ty = ty })
= do { body_expr <- dsGuarded grhss ty
; sel_binds <- mkSelectorBinds pat body_expr
+ -- We silently ignore inline pragmas; no makeCorePair
+ -- Not so cool, but really doesn't matter
; return (toOL sel_binds) }
-{-
-dsHsBind auto_scc (AbsBinds { abs_tvs = [], abs_ev_vars = []
- , abs_exports = exports, abs_ev_binds = ev_binds
- , abs_binds = binds })
- = do { bind_prs <- ds_lhs_binds NoSccs binds
- ; ds_ev_binds <- dsTcEvBinds ev_binds
-
- ; let core_prs = addEvPairs ds_ev_binds bind_prs
- env = mkABEnv exports
- do_one (lcl_id, rhs)
- | Just (_, gbl_id, _, spec_prags) <- lookupVarEnv env lcl_id
- = do { let rhs' = addAutoScc auto_scc gbl_id rhs
- ; (spec_binds, rules) <- dsSpecs gbl_id (Let (Rec core_prs) rhs') spec_prags
- -- See Note [Specialising in no-dict case]
- ; let gbl_id' = addIdSpecialisations gbl_id rules
- main_bind = makeCorePair gbl_id' False 0 rhs'
- ; return (main_bind : spec_binds) }
-
- | otherwise = return [(lcl_id, rhs)]
-
- locals' = [(lcl_id, Var gbl_id) | (_, gbl_id, lcl_id, _) <- exports]
- -- Note [Rules and inlining]
- ; export_binds <- mapM do_one core_prs
- ; return (concat export_binds ++ locals' ++ rest) }
- -- No Rec needed here (contrast the other AbsBinds cases)
- -- because we can rely on the enclosing dsBind to wrap in Rec
-
-
-dsHsBind auto_scc rest (AbsBinds { abs_tvs = tyvars, abs_ev_vars = []
- , abs_exports = exports, abs_ev_binds = ev_binds
- , abs_binds = binds })
- | opt_DsMultiTyVar -- This (static) debug flag just lets us
- -- switch on and off this optimisation to
- -- see if it has any impact; it is on by default
- , allOL isLazyEvBind ev_binds
- = -- Note [Abstracting over tyvars only]
- do { bind_prs <- ds_lhs_binds NoSccs binds
- ; ds_ev_binds <- dsTcEvBinds ev_binds
-
- ; let core_prs = addEvPairs ds_ev_binds bind_prs
- arby_env = mkArbitraryTypeEnv tyvars exports
- bndrs = mkVarSet (map fst core_prs)
-
- add_lets | core_prs `lengthExceeds` 10 = add_some
- | otherwise = mkLets
- add_some lg_binds rhs = mkLets [ NonRec b r | NonRec b r <- lg_binds
- , b `elemVarSet` fvs] rhs
- where
- fvs = exprSomeFreeVars (`elemVarSet` bndrs) rhs
-
- env = mkABEnv exports
- mk_lg_bind lcl_id gbl_id tyvars
- = NonRec (setIdInfo lcl_id vanillaIdInfo)
- -- Nuke the IdInfo so that no old unfoldings
- -- confuse use (it might mention something not
- -- even in scope at the new site
- (mkTyApps (Var gbl_id) (mkTyVarTys tyvars))
-
- do_one lg_binds (lcl_id, rhs)
- | Just (id_tvs, gbl_id, _, spec_prags) <- lookupVarEnv env lcl_id
- = do { let rhs' = addAutoScc auto_scc gbl_id $
- mkLams id_tvs $
- mkLets [ NonRec tv (Type (lookupVarEnv_NF arby_env tv))
- | tv <- tyvars, not (tv `elem` id_tvs)] $
- add_lets lg_binds rhs
- ; (spec_binds, rules) <- dsSpecs gbl_id rhs' spec_prags
- ; let gbl_id' = addIdSpecialisations gbl_id rules
- main_bind = makeCorePair gbl_id' False 0 rhs'
- ; return (mk_lg_bind lcl_id gbl_id' id_tvs, main_bind : spec_binds) }
- | otherwise
- = do { non_exp_gbl_id <- newUniqueId lcl_id (mkForAllTys tyvars (idType lcl_id))
- ; return (mk_lg_bind lcl_id non_exp_gbl_id tyvars,
- [(non_exp_gbl_id, mkLams tyvars (add_lets lg_binds rhs))]) }
-
- ; (_, core_prs') <- fixDs (\ ~(lg_binds, _) -> mapAndUnzipM (do_one lg_binds) core_prs)
- ; return (concat core_prs' ++ rest) }
--}
-
-- A common case: one exported variable
-- Non-recursive bindings come through this way
-- So do self-recursive bindings, and recursive bindings
Let core_bind $
Var local
- ; (spec_binds, rules) <- dsSpecs global rhs prags
+ ; (spec_binds, rules) <- dsSpecs rhs prags
; let global' = addIdSpecialisations global rules
main_bind = makeCorePair global' (isDefaultMethod prags)
mkTupleSelector locals' (locals' !! n) tup_id $
mkVarApps (mkTyApps (Var poly_tup_id) ty_args)
dicts
- ; (spec_binds, rules) <- dsSpecs global
- (Let (NonRec poly_tup_id poly_tup_rhs) rhs)
- spec_prags
+ full_rhs = Let (NonRec poly_tup_id poly_tup_rhs) rhs
+ ; (spec_binds, rules) <- dsSpecs full_rhs spec_prags
+
; let global' = addIdSpecialisations global rules
; return ((global', rhs) `consOL` spec_binds) }
where
| is_default_method -- Default methods are *always* inlined
= (gbl_id `setIdUnfolding` mkCompulsoryUnfolding rhs, rhs)
- | not (isInlinePragma inline_prag)
- = (gbl_id, rhs)
+ | otherwise
+ = case inlinePragmaSpec inline_prag of
+ EmptyInlineSpec -> (gbl_id, rhs)
+ NoInline -> (gbl_id, rhs)
+ Inlinable -> (gbl_id `setIdUnfolding` inlinable_unf, rhs)
+ Inline -> inline_pair
- | Just arity <- inlinePragmaSat inline_prag
+ where
+ inline_prag = idInlinePragma gbl_id
+ inlinable_unf = mkInlinableUnfolding rhs
+ inline_pair
+ | Just arity <- inlinePragmaSat inline_prag
-- Add an Unfolding for an INLINE (but not for NOINLINE)
-- And eta-expand the RHS; see Note [Eta-expanding INLINE things]
- , let real_arity = dict_arity + arity
+ , let real_arity = dict_arity + arity
-- NB: The arity in the InlineRule takes account of the dictionaries
- = (gbl_id `setIdUnfolding` mkInlineRule rhs (Just real_arity),
- etaExpand real_arity rhs)
+ = ( gbl_id `setIdUnfolding` mkInlineUnfolding (Just real_arity) rhs
+ , etaExpand real_arity rhs)
+
+ | otherwise
+ = pprTrace "makeCorePair: arity missing" (ppr gbl_id) $
+ (gbl_id `setIdUnfolding` mkInlineUnfolding Nothing rhs, rhs)
- | otherwise
- = (gbl_id `setIdUnfolding` mkInlineRule rhs Nothing, rhs)
- where
- inline_prag = idInlinePragma gbl_id
dictArity :: [Var] -> Arity
-- Don't count coercion variables in arity
because they desugar to
M.f = /\a. let f_lcl = ...f_lcl... in f_lcl
Although I'm a bit worried about whether full laziness might
-float the f_lcl binding out and then inline M.f at its call site -}
+float the f_lcl binding out and then inline M.f at its call site
Note [Specialising in no-dict case]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
\begin{code}
------------------------
-dsSpecs :: Id -- The polymorphic Id
- -> CoreExpr -- Its rhs
+dsSpecs :: CoreExpr -- Its rhs
-> TcSpecPrags
-> DsM ( OrdList (Id,CoreExpr) -- Binding for specialised Ids
, [CoreRule] ) -- Rules for the Global Ids
-- See Note [Implementing SPECIALISE pragmas]
-dsSpecs poly_id poly_rhs prags
- = case prags of
- IsDefaultMethod -> return (nilOL, [])
- SpecPrags sps -> do { pairs <- mapMaybeM spec_one sps
- ; let (spec_binds_s, rules) = unzip pairs
- ; return (concatOL spec_binds_s, rules) }
- where
- spec_one :: Located TcSpecPrag -> DsM (Maybe (OrdList (Id,CoreExpr), CoreRule))
- spec_one (L loc (SpecPrag spec_co spec_inl))
- = putSrcSpanDs loc $
- do { let poly_name = idName poly_id
- ; spec_name <- newLocalName poly_name
- ; wrap_fn <- dsHsWrapper spec_co
- ; let (bndrs, ds_lhs) = collectBinders (wrap_fn (Var poly_id))
- spec_ty = mkPiTypes bndrs (exprType ds_lhs)
- ; case decomposeRuleLhs ds_lhs of {
- Nothing -> do { warnDs (decomp_msg spec_co)
- ; return Nothing } ;
-
- Just (_fn, args) ->
-
- -- Check for dead binders: Note [Unused spec binders]
- let arg_fvs = exprsFreeVars args
- bad_bndrs = filterOut (`elemVarSet` arg_fvs) bndrs
- in if not (null bad_bndrs)
- then do { warnDs (dead_msg bad_bndrs); return Nothing }
- else do
-
- { (spec_unf, unf_pairs) <- specUnfolding wrap_fn spec_ty (realIdUnfolding poly_id)
-
- ; let spec_id = mkLocalId spec_name spec_ty
- `setInlinePragma` inl_prag
- `setIdUnfolding` spec_unf
- inl_prag | isDefaultInlinePragma spec_inl = idInlinePragma poly_id
- | otherwise = spec_inl
- -- Get the INLINE pragma from SPECIALISE declaration, or,
- -- failing that, from the original Id
-
- extra_dict_bndrs = [ mkLocalId (localiseName (idName d)) (idType d)
- -- See Note [Constant rule dicts]
- | d <- varSetElems (arg_fvs `delVarSetList` bndrs)
- , isDictId d]
-
- rule = mkLocalRule (mkFastString ("SPEC " ++ showSDoc (ppr poly_name)))
- AlwaysActive poly_name
- (extra_dict_bndrs ++ bndrs) args
- (mkVarApps (Var spec_id) bndrs)
-
- spec_rhs = wrap_fn poly_rhs
- spec_pair = makeCorePair spec_id False (dictArity bndrs) spec_rhs
-
- ; return (Just (spec_pair `consOL` unf_pairs, rule))
- } } }
-
+dsSpecs _ IsDefaultMethod = return (nilOL, [])
+dsSpecs poly_rhs (SpecPrags sps)
+ = do { pairs <- mapMaybeM (dsSpec (Just poly_rhs)) sps
+ ; let (spec_binds_s, rules) = unzip pairs
+ ; return (concatOL spec_binds_s, rules) }
+
+dsSpec :: Maybe CoreExpr -- Just rhs => RULE is for a local binding
+ -- Nothing => RULE is for an imported Id
+ -- rhs is in the Id's unfolding
+ -> Located TcSpecPrag
+ -> DsM (Maybe (OrdList (Id,CoreExpr), CoreRule))
+dsSpec mb_poly_rhs (L loc (SpecPrag poly_id spec_co spec_inl))
+ = putSrcSpanDs loc $
+ do { let poly_name = idName poly_id
+ ; spec_name <- newLocalName poly_name
+ ; wrap_fn <- dsHsWrapper spec_co
+ ; let (bndrs, ds_lhs) = collectBinders (wrap_fn (Var poly_id))
+ spec_ty = mkPiTypes bndrs (exprType ds_lhs)
+ ; case decomposeRuleLhs ds_lhs of {
+ Nothing -> do { warnDs (decomp_msg spec_co)
+ ; return Nothing } ;
+
+ Just (_fn, args) ->
+
+ -- Check for dead binders: Note [Unused spec binders]
+ let arg_fvs = exprsFreeVars args
+ bad_bndrs = filterOut (`elemVarSet` arg_fvs) bndrs
+ in if not (null bad_bndrs)
+ then do { warnDs (dead_msg bad_bndrs); return Nothing }
+ else do
+
+ { (spec_unf, unf_pairs) <- specUnfolding wrap_fn spec_ty (realIdUnfolding poly_id)
+
+ ; let spec_id = mkLocalId spec_name spec_ty
+ `setInlinePragma` inl_prag
+ `setIdUnfolding` spec_unf
+ inl_prag | isDefaultInlinePragma spec_inl = idInlinePragma poly_id
+ | otherwise = spec_inl
+ -- Get the INLINE pragma from SPECIALISE declaration, or,
+ -- failing that, from the original Id
+
+ extra_dict_bndrs = [ mkLocalId (localiseName (idName d)) (idType d)
+ -- See Note [Constant rule dicts]
+ | d <- varSetElems (arg_fvs `delVarSetList` bndrs)
+ , isDictId d]
+
+ rule = mkRule False {- Not auto -} is_local_id
+ (mkFastString ("SPEC " ++ showSDoc (ppr poly_name)))
+ AlwaysActive poly_name
+ (extra_dict_bndrs ++ bndrs) args
+ (mkVarApps (Var spec_id) bndrs)
+
+ spec_rhs = wrap_fn poly_rhs
+ spec_pair = makeCorePair spec_id False (dictArity bndrs) spec_rhs
+
+ ; return (Just (spec_pair `consOL` unf_pairs, rule))
+ } } }
+ where
dead_msg bs = vcat [ sep [ptext (sLit "Useless constraint") <> plural bs
<+> ptext (sLit "in specialied type:"),
nest 2 (pprTheta (map get_pred bs))]
= hang (ptext (sLit "Specialisation too complicated to desugar; ignored"))
2 (pprHsWrapper (ppr poly_id) spec_co)
+ is_local_id = isJust mb_poly_rhs
+ poly_rhs | Just rhs <- mb_poly_rhs
+ = rhs
+ | Just unfolding <- maybeUnfoldingTemplate (idUnfolding poly_id)
+ = unfolding
+ | otherwise = pprPanic "dsImpSpecs" (ppr poly_id)
+ -- In the Nothing case the specialisation is for an imported Id
+ -- whose unfolding gives the RHS to be specialised
+ -- The type checker has checked that it has an unfolding
specUnfolding :: (CoreExpr -> CoreExpr) -> Type
-> Unfolding -> DsM (Unfolding, OrdList (Id,CoreExpr))
projects / ghc-hetmet.git / blobdiff