%
-% (c) The GRASP/AQUA Project, Glasgow University, 1993-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1993-1998
%
\section[WorkWrap]{Worker/wrapper-generating back-end of strictness analyser}
\begin{code}
-#include "HsVersions.h"
-
-module WorkWrap ( workersAndWrappers ) where
+module WorkWrap ( workersAndWrappers, getWorkerIdAndCons ) where
-import Ubiq{-uitous-}
+#include "HsVersions.h"
import CoreSyn
-import CoreUnfold ( UnfoldingGuidance(..) )
+import CoreUnfold ( Unfolding, certainlySmallEnoughToInline, calcUnfoldingGuidance )
+import CmdLineOpts ( opt_UnfoldingCreationThreshold )
+
import CoreUtils ( coreExprType )
-import Id ( idWantsToBeINLINEd, getIdStrictness, mkWorkerId,
- getIdInfo
- )
-import IdInfo ( noIdInfo, addInfo_UF, indicatesWorker,
- mkStrictnessInfo, StrictnessInfo(..)
+import Const ( Con(..) )
+import DataCon ( DataCon )
+import MkId ( mkWorkerId )
+import Id ( Id, getIdStrictness,
+ setIdStrictness, setInlinePragma, idWantsToBeINLINEd,
)
+import VarSet
+import Type ( splitAlgTyConApp_maybe )
+import IdInfo ( mkStrictnessInfo, StrictnessInfo(..),
+ InlinePragInfo(..) )
import SaLib
-import UniqSupply ( returnUs, thenUs, mapUs, getUnique, UniqSM(..) )
+import UniqSupply ( UniqSupply, initUs, returnUs, thenUs, mapUs, getUniqueUs, UniqSM )
+import UniqSet
import WwLib
-import Util ( panic{-ToDo:rm-} )
-
-replaceIdInfo = panic "WorkWrap.replaceIdInfo (ToDo)"
-iWantToBeINLINEd = panic "WorkWrap.iWantToBeINLINEd (ToDo)"
+import Outputable
\end{code}
We take Core bindings whose binders have their strictness attached (by
\end{enumerate}
\begin{code}
-workersAndWrappers :: [CoreBinding] -> UniqSM [CoreBinding]
+workersAndWrappers :: UniqSupply -> [CoreBind] -> [CoreBind]
-workersAndWrappers top_binds
- = mapUs (wwBind True{-top-level-}) top_binds `thenUs` \ top_binds2 ->
+workersAndWrappers us top_binds
+ = initUs us $
+ mapUs (wwBind True{-top-level-}) top_binds `thenUs` \ top_binds2 ->
let
top_binds3 = map make_top_binding top_binds2
in
returnUs (concat top_binds3)
where
- make_top_binding :: WwBinding -> [CoreBinding]
+ make_top_binding :: WwBinding -> [CoreBind]
make_top_binding (WwLet binds) = binds
\end{code}
\begin{code}
wwBind :: Bool -- True <=> top-level binding
- -> CoreBinding
+ -> CoreBind
-> UniqSM WwBinding -- returns a WwBinding intermediate form;
-- the caller will convert to Expr/Binding,
-- as appropriate.
wwBind top_level (NonRec binder rhs)
- = wwExpr rhs `thenUs` \ new_rhs ->
- tryWW binder new_rhs `thenUs` \ new_pairs ->
+ = wwExpr rhs `thenUs` \ new_rhs ->
+ tryWW True {- non-recursive -} binder new_rhs `thenUs` \ new_pairs ->
returnUs (WwLet [NonRec b e | (b,e) <- new_pairs])
-- Generated bindings must be non-recursive
-- because the original binding was.
returnUs (WwLet [Rec (concat new_pairs)])
where
do_one (binder, rhs) = wwExpr rhs `thenUs` \ new_rhs ->
- tryWW binder new_rhs
+ tryWW False {- recursive -} binder new_rhs
\end{code}
@wwExpr@ basically just walks the tree, looking for appropriate
\begin{code}
wwExpr :: CoreExpr -> UniqSM CoreExpr
+wwExpr e@(Type _) = returnUs e
wwExpr e@(Var _) = returnUs e
-wwExpr e@(Lit _) = returnUs e
-wwExpr e@(Con _ _) = returnUs e
-wwExpr e@(Prim _ _) = returnUs e
+
+wwExpr e@(Con con args)
+ = mapUs wwExpr args `thenUs` \ args' ->
+ returnUs (Con con args')
wwExpr (Lam binder expr)
= wwExpr expr `thenUs` \ new_expr ->
wwExpr (App f a)
= wwExpr f `thenUs` \ new_f ->
- returnUs (App new_f a)
-
-wwExpr (SCC cc expr)
- = wwExpr expr `thenUs` \ new_expr ->
- returnUs (SCC cc new_expr)
+ wwExpr a `thenUs` \ new_a ->
+ returnUs (App new_f new_a)
-wwExpr (Coerce c ty expr)
+wwExpr (Note note expr)
= wwExpr expr `thenUs` \ new_expr ->
- returnUs (Coerce c ty new_expr)
+ returnUs (Note note new_expr)
wwExpr (Let bind expr)
= wwBind False{-not top-level-} bind `thenUs` \ intermediate_bind ->
wwExpr expr `thenUs` \ new_expr ->
returnUs (mash_ww_bind intermediate_bind new_expr)
where
- mash_ww_bind (WwLet binds) body = mkCoLetsNoUnboxed binds body
+ mash_ww_bind (WwLet binds) body = mkLets binds body
mash_ww_bind (WwCase case_fn) body = case_fn body
-wwExpr (Case expr alts)
+wwExpr (Case expr binder alts)
= wwExpr expr `thenUs` \ new_expr ->
- ww_alts alts `thenUs` \ new_alts ->
- returnUs (Case new_expr new_alts)
+ mapUs ww_alt alts `thenUs` \ new_alts ->
+ returnUs (Case new_expr binder new_alts)
where
- ww_alts (AlgAlts alts deflt)
- = mapUs ww_alg_alt alts `thenUs` \ new_alts ->
- ww_deflt deflt `thenUs` \ new_deflt ->
- returnUs (AlgAlts new_alts new_deflt)
-
- ww_alts (PrimAlts alts deflt)
- = mapUs ww_prim_alt alts `thenUs` \ new_alts ->
- ww_deflt deflt `thenUs` \ new_deflt ->
- returnUs (PrimAlts new_alts new_deflt)
-
- ww_alg_alt (con, binders, rhs)
+ ww_alt (con, binders, rhs)
= wwExpr rhs `thenUs` \ new_rhs ->
returnUs (con, binders, new_rhs)
-
- ww_prim_alt (lit, rhs)
- = wwExpr rhs `thenUs` \ new_rhs ->
- returnUs (lit, new_rhs)
-
- ww_deflt NoDefault
- = returnUs NoDefault
-
- ww_deflt (BindDefault binder rhs)
- = wwExpr rhs `thenUs` \ new_rhs ->
- returnUs (BindDefault binder new_rhs)
\end{code}
%************************************************************************
The only reason this is monadised is for the unique supply.
\begin{code}
-tryWW :: Id -- the fn binder
- -> CoreExpr -- the bound rhs; its innards
+tryWW :: Bool -- True <=> a non-recursive binding
+ -> Id -- The fn binder
+ -> CoreExpr -- The bound rhs; its innards
-- are already ww'd
-> UniqSM [(Id, CoreExpr)] -- either *one* or *two* pairs;
-- if one, then no worker (only
-- the orig "wrapper" lives on);
-- if two, then a worker and a
-- wrapper.
-tryWW fn_id rhs
- | idWantsToBeINLINEd fn_id
- -- No point in worker/wrappering something that is going to be
- -- INLINEd wholesale anyway. If the strictness analyser is run
- -- twice, this test also prevents wrappers (which are INLINEd)
- -- from being re-done.
- = do_nothing
-
- | otherwise
- = case (getIdStrictness fn_id) of
-
- NoStrictnessInfo -> do_nothing
- BottomGuaranteed -> do_nothing
- StrictnessInfo [] _ -> do_nothing -- V weird (but possible?)
-
- StrictnessInfo args_info _ ->
- if not (indicatesWorker args_info) then
- do_nothing
- else
-
- -- OK, it looks as if a worker is worth a try
- let
- (uvars, tyvars, args, body) = collectBinders rhs
- body_ty = coreExprType body
- in
- mkWwBodies body_ty tyvars args args_info `thenUs` \ result ->
- case result of
-
- Nothing -> -- Very peculiar. This can only happen if we hit an
- -- abstract type, which we shouldn't have since we've
- -- constructed the args_info in this module!
-
- -- False. We might hit the all-args-absent-and-the-
- -- body-is-unboxed case. A Nothing is legit. (WDP 94/10)
- do_nothing
-
- Just (wrapper_w_hole, worker_w_hole, worker_strictness, worker_ty_w_hole) ->
-
- -- Terrific! It worked!
- getUnique `thenUs` \ worker_uniq ->
- let
- worker_ty = worker_ty_w_hole body_ty
-
- worker_id = mkWorkerId worker_uniq fn_id worker_ty
- (noIdInfo `addInfo` worker_strictness)
-
- wrapper_rhs = wrapper_w_hole worker_id
- worker_rhs = worker_w_hole body
-
- revised_strictness_info
- = -- We know the basic strictness info already, but
- -- we need to slam in the exact identity of the
- -- worker Id:
- mkStrictnessInfo args_info (Just worker_id)
-
- wrapper_id = fn_id `replaceIdInfo`
- (getIdInfo fn_id `addInfo`
- revised_strictness_info `addInfo_UF`
- iWantToBeINLINEd UnfoldAlways)
- -- NB! the "iWantToBeINLINEd" part adds an INLINE pragma to
- -- the wrapper, which is of course what we want.
- in
- returnUs [ (worker_id, worker_rhs), -- worker comes first
- (wrapper_id, wrapper_rhs) ] -- because wrapper mentions it
+tryWW non_rec fn_id rhs
+ | idWantsToBeINLINEd fn_id
+ || (non_rec && -- Don't split if its non-recursive and small
+ certainlySmallEnoughToInline fn_id unfold_guidance
+ )
+ -- No point in worker/wrappering something that is going to be
+ -- INLINEd wholesale anyway. If the strictness analyser is run
+ -- twice, this test also prevents wrappers (which are INLINEd)
+ -- from being re-done.
+
+ || not has_strictness_info
+ || not (worthSplitting revised_wrap_args_info)
+ = returnUs [ (fn_id, rhs) ]
+
+ | otherwise -- Do w/w split
+ = let
+ (tyvars, wrap_args, body) = collectTyAndValBinders rhs
+ in
+ mkWwBodies tyvars wrap_args
+ (coreExprType body)
+ revised_wrap_args_info `thenUs` \ (wrap_fn, work_fn, work_demands) ->
+ getUniqueUs `thenUs` \ work_uniq ->
+ let
+ work_rhs = work_fn body
+ work_id = mkWorkerId work_uniq fn_id (coreExprType work_rhs) `setIdStrictness`
+ mkStrictnessInfo work_demands False
+
+ wrap_rhs = wrap_fn work_id
+ wrap_id = fn_id `setIdStrictness` mkStrictnessInfo revised_wrap_args_info True
+ `setInlinePragma` IWantToBeINLINEd
+ -- Add info to the wrapper:
+ -- (a) we want to inline it everywhere
+ -- (b) we want to pin on its revised stricteness info
+ -- (c) we pin on its worker id and the list of constructors mentioned in the wrapper
+ in
+ returnUs ([(work_id, work_rhs), (wrap_id, wrap_rhs)])
+ -- Worker first, because wrapper mentions it
+ where
+ strictness_info = getIdStrictness fn_id
+ has_strictness_info = case strictness_info of
+ StrictnessInfo _ _ -> True
+ other -> False
+
+ wrap_args_info = case strictness_info of
+ StrictnessInfo args_info _ -> args_info
+ revised_wrap_args_info = setUnpackStrategy wrap_args_info
+
+ unfold_guidance = calcUnfoldingGuidance opt_UnfoldingCreationThreshold rhs
+
+-- This rather (nay! extremely!) crude function looks at a wrapper function, and
+-- snaffles out (a) the worker Id and (b) constructors needed to
+-- make the wrapper.
+-- These are needed when we write an interface file.
+getWorkerIdAndCons :: Id -> CoreExpr -> (Id, UniqSet DataCon)
+getWorkerIdAndCons wrap_id wrapper_fn
+ = (get_work_id wrapper_fn, get_cons wrapper_fn)
where
- do_nothing = returnUs [ (fn_id, rhs) ]
+ get_work_id (Lam _ body) = get_work_id body
+ get_work_id (Case _ _ [(_,_,rhs)]) = get_work_id rhs
+ get_work_id (Note _ body) = get_work_id body
+ get_work_id (Let _ body) = get_work_id body
+ get_work_id (App fn _) = get_work_id fn
+ get_work_id (Var work_id) = work_id
+ get_work_id other = pprPanic "getWorkerIdAndCons" (ppr wrap_id)
+
+
+ get_cons (Lam _ body) = get_cons body
+ get_cons (Let (NonRec _ rhs) body) = get_cons rhs `unionUniqSets` get_cons body
+
+ get_cons (Case e _ [(DataCon dc,_,rhs)]) = (get_cons e `unionUniqSets` get_cons rhs)
+ `addOneToUniqSet` dc
+
+ -- Coercions don't mention the construtor now,
+ -- but we must still put the constructor in the interface
+ -- file so that the RHS of the newtype decl is imported
+ get_cons (Note (Coerce to_ty from_ty) body)
+ = get_cons body `addOneToUniqSet` con
+ where
+ con = case splitAlgTyConApp_maybe from_ty of
+ Just (_, _, [con]) -> con
+ other -> pprPanic "getWorkerIdAndCons" (ppr to_ty)
+
+ get_cons other = emptyUniqSet
\end{code}
projects / ghc-hetmet.git / blobdiff