import MkId ( voidArgId, realWorldPrimId )
import FiniteMap
import Maybes ( catMaybes, isJust )
+import BasicTypes ( isNeverActive, inlinePragmaActivation )
import Bag
import Util
import Outputable
\begin{code}
specVar :: Subst -> Id -> CoreExpr
-specVar subst v = lookupIdSubst subst v
+specVar subst v = lookupIdSubst (text "specVar") subst v
specExpr :: Subst -> CoreExpr -> SpecM (CoreExpr, UsageDetails)
-- We carry a substitution down:
| rhs_tyvars `lengthIs` n_tyvars -- Rhs of fn's defn has right number of big lambdas
&& rhs_ids `lengthAtLeast` n_dicts -- and enough dict args
&& notNull calls_for_me -- And there are some calls to specialise
+ && not (isNeverActive (idInlineActivation fn))
+ -- Don't specialise NOINLINE things
+ -- See Note [Auto-specialisation and RULES]
-- && not (certainlyWillInline (idUnfolding fn)) -- And it's not small
-- See Note [Inline specialisation] for why we do not
(tyvars, theta, _) = tcSplitSigmaTy fn_type
n_tyvars = length tyvars
n_dicts = length theta
- inline_act = idInlineActivation fn
+ inl_act = inlinePragmaActivation (idInlinePragma fn)
-- Figure out whether the function has an INLINE pragma
-- See Note [Inline specialisations]
ty_args = mk_ty_args call_ts
rhs_subst = CoreSubst.extendTvSubstList subst spec_tv_binds
- ; (rhs_subst1, inst_dict_ids) <- cloneDictBndrs rhs_subst rhs_dict_ids
+ ; (rhs_subst1, inst_dict_ids) <- newDictBndrs rhs_subst rhs_dict_ids
-- Clone rhs_dicts, including instantiating their types
; let (rhs_subst2, dx_binds) = bindAuxiliaryDicts rhs_subst1 $
spec_id_ty = mkPiTypes lam_args body_ty
; spec_f <- newSpecIdSM fn spec_id_ty
- ; let spec_f_w_arity = setIdArity spec_f (max 0 (fn_arity - n_dicts))
- -- Adding arity information just propagates it a bit faster
- -- See Note [Arity decrease] in Simplify
-
; (spec_rhs, rhs_uds) <- specExpr rhs_subst2 (mkLams lam_args body)
; let
-- The rule to put in the function's specialisation is:
rule_name = mkFastString ("SPEC " ++ showSDoc (ppr fn <+> ppr spec_ty_args))
spec_env_rule = mkLocalRule
rule_name
- inline_act -- Note [Auto-specialisation and RULES]
+ inl_act -- Note [Auto-specialisation and RULES]
(idName fn)
(poly_tyvars ++ inst_dict_ids)
inst_args
- (mkVarApps (Var spec_f_w_arity) app_args)
+ (mkVarApps (Var spec_f) app_args)
-- Add the { d1' = dx1; d2' = dx2 } usage stuff
final_uds = foldr consDictBind rhs_uds dx_binds
+ -- Adding arity information just propagates it a bit faster
+ -- See Note [Arity decrease] in Simplify
+ -- Copy InlinePragma information from the parent Id.
+ -- So if f has INLINE[1] so does spec_f
+ spec_f_w_arity = spec_f `setIdArity` max 0 (fn_arity - n_dicts)
+ `setInlineActivation` inl_act
+
+ -- Add an InlineRule if the parent has one
-- See Note [Inline specialisations]
- final_spec_f | Just sat <- fn_has_inline_rule
- = spec_f_w_arity `setInlineActivation` inline_act
- `setIdUnfolding` mkInlineRule sat spec_rhs spec_arity
- -- I'm not sure this should be unconditionally InlSat
- | otherwise
- = spec_f_w_arity
+ final_spec_f
+ | Just sat <- fn_has_inline_rule
+ = let
+ mb_spec_arity = if sat then Just spec_arity else Nothing
+ in
+ spec_f_w_arity `setIdUnfolding` mkInlineRule spec_rhs mb_spec_arity
+ | otherwise
+ = spec_f_w_arity
+
; return (Just ((final_spec_f, spec_rhs), final_uds, spec_env_rule)) } }
where
my_zipEqual xs ys zs
go subst binds ((d, dx_id, dx) : pairs)
| exprIsTrivial dx = go (extendIdSubst subst d dx) binds pairs
-- No auxiliary binding necessary
+ -- Note that we bind the *original* dict in the substitution,
+ -- overriding any d->dx_id binding put there by substBndrs
+
| otherwise = go subst_w_unf (NonRec dx_id dx : binds) pairs
where
dx_id1 = dx_id `setIdUnfolding` mkUnfolding False False dx
-- a consequent call (g d') with an auxiliary definition
-- d' = df dNumInt
-- We want that consequent call to look interesting
+ --
+ -- Again, note that we bind the *original* dict in the substitution,
+ -- overriding any d->dx_id binding put there by substBndrs
\end{code}
Note [From non-recursive to recursive]
RULE f g_spec = 0
But that's a bit complicated. For now we ask the programmer's help,
-by *copying the INLINE activation pragma* to the auto-specialised rule.
-So if g says {-# NOINLINE[2] g #-}, then the auto-spec rule will also
-not be active until phase 2.
+by *copying the INLINE activation pragma* to the auto-specialised
+rule. So if g says {-# NOINLINE[2] g #-}, then the auto-spec rule
+will also not be active until phase 2. And that's what programmers
+should jolly well do anyway, even aside from specialisation, to ensure
+that g doesn't inline too early.
+This in turn means that the RULE would never fire for a NOINLINE
+thing so not much point in generating a specialisation at all.
Note [Specialisation shape]
~~~~~~~~~~~~~~~~~~~~~~~~~~~
where choose doesn't have any dict arguments. Thus far I have not
tried to fix this (wait till there's a real example).
-
Note [Inline specialisations]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We transfer to the specialised function any INLINE stuff from the
-original. This means (a) the Activation in the IdInfo, and (b) any
-InlineMe on the RHS. We do not, however, transfer the RuleMatchInfo
-since we do not expect the specialisation to occur in rewrite rules.
+original. This means
+ (a) the Activation for its inlining (from its InlinePragma)
+ (b) any InlineRule
This is a change (Jun06). Previously the idea is that the point of
inlining was precisely to specialise the function at its call site,
boring to trigger inlining), and it's certainly better to call the
specialised version.
-A case in point is dictionary functions, which are current marked
-INLINE, but which are worth specialising.
-
%************************************************************************
%* *
let (subst', bndrs') = cloneRecIdBndrs subst us (map fst pairs)
return (subst', subst', Rec (bndrs' `zip` map snd pairs))
-cloneDictBndrs :: Subst -> [CoreBndr] -> SpecM (Subst, [CoreBndr])
-cloneDictBndrs subst bndrs
- = do { us <- getUniqueSupplyM
- ; return (cloneIdBndrs subst us bndrs) }
+newDictBndrs :: Subst -> [CoreBndr] -> SpecM (Subst, [CoreBndr])
+-- Make up completely fresh binders for the dictionaries
+-- Their bindings are going to float outwards
+newDictBndrs subst bndrs
+ = do { bndrs' <- mapM new bndrs
+ ; let subst' = extendIdSubstList subst
+ [(d, Var d') | (d,d') <- bndrs `zip` bndrs']
+ ; return (subst', bndrs' ) }
+ where
+ new b = do { uniq <- getUniqueM
+ ; let n = idName b
+ ty' = CoreSubst.substTy subst (idType b)
+ ; return (mkUserLocal (nameOccName n) uniq ty' (getSrcSpan n)) }
newSpecIdSM :: Id -> Type -> SpecM Id
-- Give the new Id a similar occurrence name to the old one
newSpecIdSM old_id new_ty
= do { uniq <- getUniqueM
- ; let
- name = idName old_id
- new_occ = mkSpecOcc (nameOccName name)
- new_id = mkUserLocal new_occ uniq new_ty (getSrcSpan name)
+ ; let name = idName old_id
+ new_occ = mkSpecOcc (nameOccName name)
+ new_id = mkUserLocal new_occ uniq new_ty (getSrcSpan name)
; return new_id }
\end{code}
projects / ghc-hetmet.git / blobdiff