\section[WwLib]{A library for the ``worker/wrapper'' back-end to the strictness analyser}
\begin{code}
-{-# OPTIONS -w #-}
--- The above warning supression flag is a temporary kludge.
--- While working on this module you are encouraged to remove it and fix
--- any warnings in the module. See
--- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
--- for details
-
module WwLib ( mkWwBodies, mkWWstr, mkWorkerArgs ) where
#include "HsVersions.h"
setIdInfo
)
import IdInfo ( vanillaIdInfo )
-import DataCon ( deepSplitProductType_maybe, deepSplitProductType )
+import DataCon
import NewDemand ( Demand(..), DmdResult(..), Demands(..) )
import MkId ( realWorldPrimId, voidArgId, mkRuntimeErrorApp, rUNTIME_ERROR_ID,
mkUnpackCase, mkProductBox )
import TysWiredIn ( tupleCon )
-import Type ( Type, isUnLiftedType, mkFunTys,
- splitForAllTys, splitFunTys, isAlgType
- )
+import Type
import Coercion ( mkSymCoercion, splitNewTypeRepCo_maybe )
import BasicTypes ( Boxity(..) )
import Var ( Var, isId )
import UniqSupply ( returnUs, thenUs, getUniquesUs, UniqSM )
+import Unique
import Util ( zipWithEqual, notNull )
import Outputable
import List ( zipWith4 )
applyToVars :: [Var] -> CoreExpr -> CoreExpr
applyToVars vars fn = mkVarApps fn vars
+mk_wrap_arg :: Unique -> Type -> NewDemand.Demand -> Bool -> Id
mk_wrap_arg uniq ty dmd one_shot
= set_one_shot one_shot (setIdNewDemandInfo (mkSysLocal FSLIT("w") uniq ty) dmd)
where
CoreExpr -> CoreExpr) -- Worker body, lacking the original body of the function,
-- and lacking its lambdas.
-- This fn does the reboxing
-
-----------------------
-nop_fn body = body
-
-----------------------
mkWWstr []
= returnUs ([], nop_fn, nop_fn)
mkWWstr args `thenUs` \ (args2, wrap_fn2, work_fn2) ->
returnUs (args1 ++ args2, wrap_fn1 . wrap_fn2, work_fn1 . work_fn2)
-
----------------------
-- mkWWstr_one wrap_arg = (work_args, wrap_fn, work_fn)
-- * wrap_fn assumes wrap_arg is in scope,
-- brings into scope work_args (via cases)
-- * work_fn assumes work_args are in scope, a
-- brings into scope wrap_arg (via lets)
-
+mkWWstr_one :: Var -> UniqSM ([Var], CoreExpr -> CoreExpr, CoreExpr -> CoreExpr)
mkWWstr_one arg
| isTyVar arg
= returnUs ([arg], nop_fn, nop_fn)
-- during simplification, so for now I've just nuked this whole case
-- Other cases
- other_demand -> returnUs ([arg], nop_fn, nop_fn)
+ _other_demand -> returnUs ([arg], nop_fn, nop_fn)
where
-- If the wrapper argument is a one-shot lambda, then
set_one_shot | isOneShotLambda arg = setOneShotLambda
| otherwise = \x -> x
+
+----------------------
+nop_fn :: CoreExpr -> CoreExpr
+nop_fn body = body
\end{code}
Type) -- Type of worker's body
mkWWcpr body_ty RetCPR
- | not (isAlgType body_ty)
- = WARN( True, text "mkWWcpr: non-algebraic body type" <+> ppr body_ty )
+ | not (isClosedAlgType body_ty)
+ = WARN( True,
+ text "mkWWcpr: non-algebraic or open body type" <+> ppr body_ty )
returnUs (id, id, body_ty)
| n_con_args == 1 && isUnLiftedType con_arg_ty1
n_con_args = length con_arg_tys
con_arg_ty1 = head con_arg_tys
-mkWWcpr body_ty other -- No CPR info
+mkWWcpr body_ty _other -- No CPR info
= returnUs (id, id, body_ty)
-- If the original function looked like
--
-- This transform doesn't move work or allocation
-- from one cost centre to another
-
+workerCase :: Id -> CoreExpr -> [Id] -> DataCon -> CoreExpr -> CoreExpr
workerCase bndr (Note (SCC cc) e) args con body = Note (SCC cc) (mkUnpackCase bndr e args con body)
workerCase bndr e args con body = mkUnpackCase bndr e args con body
\end{code}
\begin{code}
+mk_absent_let :: Id -> CoreExpr -> CoreExpr
mk_absent_let arg body
| not (isUnLiftedType arg_ty)
= Let (NonRec arg abs_rhs) body
abs_rhs = mkRuntimeErrorApp rUNTIME_ERROR_ID arg_ty msg
msg = "Oops! Entered absent arg " ++ showSDocDebug (ppr arg <+> ppr (idType arg))
+mk_seq_case :: Id -> CoreExpr -> CoreExpr
mk_seq_case arg body = Case (Var arg) (sanitiseCaseBndr arg) (exprType body) [(DEFAULT, [], body)]
sanitiseCaseBndr :: Id -> Id
-- like (x+y) `seq` ....
sanitiseCaseBndr id = id `setIdInfo` vanillaIdInfo
+mk_ww_local :: Unique -> Type -> Id
mk_ww_local uniq ty = mkSysLocal FSLIT("ww") uniq ty
\end{code}