%
-% (c) The GRASP/AQUA Project, Glasgow University, 1993-1995
+% (c) The GRASP/AQUA Project, Glasgow University, 1993-1996
%
\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_Trace
-import Outputable
-import Pretty
+IMP_Ubiq(){-uitous-}
-import Id ( idType, addIdStrictness, getIdStrictness,
- getIdUnfolding, mkWorkerId,
- replaceIdInfo, getIdInfo, idWantsToBeINLINEd
+import CoreSyn
+import CoreUnfold ( Unfolding, certainlySmallEnoughToInline, calcUnfoldingGuidance )
+import CmdLineOpts ( opt_UnfoldingCreationThreshold )
+
+import CoreUtils ( coreExprType )
+import Id ( getInlinePragma, getIdStrictness, mkWorkerId,
+ addIdStrictness, addInlinePragma,
+ SYN_IE(IdSet), emptyIdSet, addOneToIdSet,
+ GenId, SYN_IE(Id)
+ )
+import IdInfo ( noIdInfo, addUnfoldInfo,
+ mkStrictnessInfo, addStrictnessInfo, StrictnessInfo(..)
)
-import IdInfo -- bits and pieces
-import Maybes ( maybeToBool, Maybe(..) )
import SaLib
-import SrcLoc ( mkUnknownSrcLoc, SrcLoc )
-import Util
+import UniqSupply ( returnUs, thenUs, mapUs, getUnique, SYN_IE(UniqSM) )
import WwLib
+import Pretty ( Doc )
+import Outputable ( ppr, PprStyle(..) )
+import Util ( pprPanic )
\end{code}
We take Core bindings whose binders have their strictness attached (by
\end{enumerate}
\begin{code}
-workersAndWrappers :: [CoreBinding] -> WwM [CoreBinding]
+workersAndWrappers :: [CoreBinding] -> UniqSM [CoreBinding]
workersAndWrappers top_binds
- = mapWw (wwBind True{-top-level-}) top_binds `thenWw` \ top_binds2 ->
+ = mapUs (wwBind True{-top-level-}) top_binds `thenUs` \ top_binds2 ->
let
top_binds3 = map make_top_binding top_binds2
in
- returnWw (concat top_binds3)
+ returnUs (concat top_binds3)
where
make_top_binding :: WwBinding -> [CoreBinding]
\begin{code}
wwBind :: Bool -- True <=> top-level binding
-> CoreBinding
- -> WwM WwBinding -- returns a WwBinding intermediate form;
+ -> UniqSM WwBinding -- returns a WwBinding intermediate form;
-- the caller will convert to Expr/Binding,
-- as appropriate.
wwBind top_level (NonRec binder rhs)
- = wwExpr rhs `thenWw` \ new_rhs ->
- tryWW binder new_rhs `thenWw` \ new_pairs ->
- returnWw (WwLet [NonRec b e | (b,e) <- new_pairs])
+ = wwExpr rhs `thenUs` \ new_rhs ->
+ tryWW 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.
------------------------------
wwBind top_level (Rec pairs)
- = mapWw do_one pairs `thenWw` \ new_pairs ->
- returnWw (WwLet [Rec (concat new_pairs)])
+ = mapUs do_one pairs `thenUs` \ new_pairs ->
+ returnUs (WwLet [Rec (concat new_pairs)])
where
- do_one (binder, rhs) = wwExpr rhs `thenWw` \ new_rhs ->
+ do_one (binder, rhs) = wwExpr rhs `thenUs` \ new_rhs ->
tryWW binder new_rhs
\end{code}
???????????????? ToDo
\begin{code}
-wwExpr :: CoreExpr -> WwM CoreExpr
-
-wwExpr e@(Var _) = returnWw e
-wwExpr e@(Lit _) = returnWw e
-wwExpr e@(Con _ _ _) = returnWw e
-wwExpr e@(Prim _ _ _) = returnWw e
+wwExpr :: CoreExpr -> UniqSM CoreExpr
-wwExpr (Lam binders expr)
- = wwExpr expr `thenWw` \ new_expr ->
- returnWw (Lam binders new_expr)
+wwExpr e@(Var _) = returnUs e
+wwExpr e@(Lit _) = returnUs e
+wwExpr e@(Con _ _) = returnUs e
+wwExpr e@(Prim _ _) = returnUs e
-wwExpr (CoTyLam ty expr)
- = wwExpr expr `thenWw` \ new_expr ->
- returnWw (CoTyLam ty new_expr)
+wwExpr (Lam binder expr)
+ = wwExpr expr `thenUs` \ new_expr ->
+ returnUs (Lam binder new_expr)
-wwExpr (App e1 e2)
- = wwExpr e1 `thenWw` \ new_e1 ->
- returnWw (App new_e1 e2)
-
-wwExpr (CoTyApp expr ty)
- = wwExpr expr `thenWw` \ new_expr ->
- returnWw (CoTyApp new_expr ty)
+wwExpr (App f a)
+ = wwExpr f `thenUs` \ new_f ->
+ returnUs (App new_f a)
wwExpr (SCC cc expr)
- = wwExpr expr `thenWw` \ new_expr ->
- returnWw (SCC cc new_expr)
+ = wwExpr expr `thenUs` \ new_expr ->
+ returnUs (SCC cc new_expr)
+
+wwExpr (Coerce c ty expr)
+ = wwExpr expr `thenUs` \ new_expr ->
+ returnUs (Coerce c ty new_expr)
wwExpr (Let bind expr)
- = wwBind False{-not top-level-} bind `thenWw` \ intermediate_bind ->
- wwExpr expr `thenWw` \ new_expr ->
- returnWw (mash_ww_bind intermediate_bind new_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 (WwCase case_fn) body = case_fn body
wwExpr (Case expr alts)
- = wwExpr expr `thenWw` \ new_expr ->
- ww_alts alts `thenWw` \ new_alts ->
- returnWw (Case new_expr new_alts)
+ = wwExpr expr `thenUs` \ new_expr ->
+ ww_alts alts `thenUs` \ new_alts ->
+ returnUs (Case new_expr new_alts)
where
ww_alts (AlgAlts alts deflt)
- = mapWw ww_alg_alt alts `thenWw` \ new_alts ->
- ww_deflt deflt `thenWw` \ new_deflt ->
- returnWw (AlgAlts new_alts new_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)
- = mapWw ww_prim_alt alts `thenWw` \ new_alts ->
- ww_deflt deflt `thenWw` \ new_deflt ->
- returnWw (PrimAlts new_alts new_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)
- = wwExpr rhs `thenWw` \ new_rhs ->
- returnWw (con, binders, new_rhs)
+ = wwExpr rhs `thenUs` \ new_rhs ->
+ returnUs (con, binders, new_rhs)
ww_prim_alt (lit, rhs)
- = wwExpr rhs `thenWw` \ new_rhs ->
- returnWw (lit, new_rhs)
+ = wwExpr rhs `thenUs` \ new_rhs ->
+ returnUs (lit, new_rhs)
ww_deflt NoDefault
- = returnWw NoDefault
+ = returnUs NoDefault
ww_deflt (BindDefault binder rhs)
- = wwExpr rhs `thenWw` \ new_rhs ->
- returnWw (BindDefault binder new_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 :: Id -- The fn binder
+ -> CoreExpr -- The bound rhs; its innards
-- are already ww'd
- -> WwM [(Id, CoreExpr)] -- either *one* or *two* pairs;
+ -> 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) = digForLambdas rhs
- body_ty = coreExprType body
- in
- uniqSMtoWwM (mkWwBodies body_ty tyvars args args_info) `thenWw` \ 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!
- getUniqueWw `thenWw` \ 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
- returnWw [ (worker_id, worker_rhs), -- worker comes first
- (wrapper_id, wrapper_rhs) ] -- because wrapper mentions it
+ | (certainlySmallEnoughToInline $
+ calcUnfoldingGuidance (getInlinePragma fn_id)
+ opt_UnfoldingCreationThreshold
+ rhs
+ )
+ -- 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
+ (uvars, tyvars, wrap_args, body) = collectBinders rhs
+ in
+ mkWwBodies tyvars wrap_args
+ (coreExprType body)
+ revised_wrap_args_info `thenUs` \ (wrap_fn, work_fn, work_demands) ->
+ getUnique `thenUs` \ work_uniq ->
+ let
+ work_rhs = work_fn body
+ work_id = mkWorkerId work_uniq fn_id (coreExprType work_rhs) work_info
+ work_info = noIdInfo `addStrictnessInfo` mkStrictnessInfo work_demands False
+
+ wrap_rhs = wrap_fn work_id
+ wrap_id = addInlinePragma (fn_id `addIdStrictness`
+ mkStrictnessInfo revised_wrap_args_info True)
+ -- 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
+
+-- This rather 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 wrap_id wrapper_fn
+ = go wrapper_fn
where
- do_nothing = returnWw [ (fn_id, rhs) ]
+ go (Lam _ body) = go body
+ go (Case _ (AlgAlts [(con,_,rhs)] _)) = let (wrap_id, cons) = go rhs
+ in (wrap_id, cons `addOneToIdSet` con)
+ go other = (get_work_id other, emptyIdSet)
+
+ get_work_id (App fn _) = get_work_id fn
+ get_work_id (Var work_id) = work_id
+ get_work_id other = pprPanic "getWorkerIdAndCons" (ppr PprDebug wrap_id)
\end{code}
projects / ghc-hetmet.git / blobdiff