Repository : ssh://darcs.haskell.org//srv/darcs/ghc On branch : new-demand-to-merge
http://hackage.haskell.org/trac/ghc/changeset/195a1a312abf01420b6956c9293a0d3a40bdfc88 >--------------------------------------------------------------- commit 195a1a312abf01420b6956c9293a0d3a40bdfc88 Author: Ilya Sergey <ilya.ser...@cs.kuleuven.be> Date: Wed Nov 7 16:29:12 2012 +0100 necessary comments added >--------------------------------------------------------------- compiler/stranal/WwLib.lhs | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-) diff --git a/compiler/stranal/WwLib.lhs b/compiler/stranal/WwLib.lhs index f471410..5874251 100644 --- a/compiler/stranal/WwLib.lhs +++ b/compiler/stranal/WwLib.lhs @@ -194,11 +194,21 @@ mkWorkerArgs args all_one_shot res_ty | otherwise = (args ++ [newArg], args ++ [realWorldPrimId]) where + -- see Note [All One-Shot Arguments of a Worker] newArg = if all_one_shot then setOneShotLambda voidArgId else voidArgId \end{code} +Note [All One-Shot Arguments of a Worker] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Sometimes, derived joint-points are just lambda-lifted thunks, whose +only argument is of the unit type and is never used. This might +interfere with the absence analysis, basing on which results these +never-used arguments are eliminated in the worker. The additional +argument `all_one_shot` of `mkWorkerArgs` is to prevent this. + %************************************************************************ %* * _______________________________________________ Cvs-ghc mailing list Cvs-ghc@haskell.org http://www.haskell.org/mailman/listinfo/cvs-ghc
