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| author | Joachim Breitner <mail@joachim-breitner.de> | 2015-02-22 10:36:15 +0100 |
|---|---|---|
| committer | Joachim Breitner <mail@joachim-breitner.de> | 2015-02-22 12:42:29 +0100 |
| commit | c76f59b6d6cdea0b1ae8449e13777f9b9bfae80e (patch) | |
| tree | 0ae409d229817843027c869aa036f9ea1820e8ae /compiler/basicTypes | |
| parent | e7420c731d0c307fcaf61c1a2ffd4daa64a8e7b1 (diff) | |
| download | haskell-wip/T9388.tar.gz | |
Introduce the new state hack in the demand analyzerwip/T9388
The new state hack, as proposed by SPJ in #9388, applies only to bound
expressions. It is implemented by constructing an artificial incoming demand that claims that it is called at most once.
(Currently, it also applies to non-top-level let-bound expressions. This
needs to be revisited.)
Diffstat (limited to 'compiler/basicTypes')
| -rw-r--r-- | compiler/basicTypes/Demand.hs | 5 | ||||
| -rw-r--r-- | compiler/basicTypes/Id.hs | 7 |
2 files changed, 10 insertions, 2 deletions
diff --git a/compiler/basicTypes/Demand.hs b/compiler/basicTypes/Demand.hs index ecf22bc51f..7b08a71cf0 100644 --- a/compiler/basicTypes/Demand.hs +++ b/compiler/basicTypes/Demand.hs @@ -37,7 +37,7 @@ module Demand ( seqDemand, seqDemandList, seqDmdType, seqStrictSig, - evalDmd, cleanEvalDmd, cleanEvalProdDmd, isStrictDmd, + evalDmd, cleanEvalDmd, cleanEvalProdDmd, cleanEvalStateHackDmd, isStrictDmd, splitDmdTy, splitFVs, deferAfterIO, postProcessUnsat, postProcessDmdTypeM, @@ -634,6 +634,9 @@ cleanEvalDmd = mkCleanDmd HeadStr Used cleanEvalProdDmd :: Arity -> CleanDemand cleanEvalProdDmd n = mkCleanDmd HeadStr (UProd (replicate n useTop)) +cleanEvalStateHackDmd :: CleanDemand +cleanEvalStateHackDmd = mkCleanDmd HeadStr (mkUCall One Used) + isSingleUsed :: JointDmd -> Bool isSingleUsed (JD {absd=a}) = is_used_once a where diff --git a/compiler/basicTypes/Id.hs b/compiler/basicTypes/Id.hs index 23d9c30066..7459cc1ba7 100644 --- a/compiler/basicTypes/Id.hs +++ b/compiler/basicTypes/Id.hs @@ -71,7 +71,7 @@ module Id ( isOneShotBndr, isOneShotLambda, isProbablyOneShotLambda, setOneShotLambda, clearOneShotLambda, updOneShotInfo, setIdOneShotInfo, - isStateHackType, + isStateHackType, isStateHackFunType, -- ** Reading 'IdInfo' fields idArity, @@ -674,6 +674,11 @@ isStateHackType ty -- Another good example is in fill_in in PrelPack.hs. We should be able to -- spot that fill_in has arity 2 (and when Keith is done, we will) but we can't yet. +isStateHackFunType :: Type -> Bool +isStateHackFunType ty + = case splitFunTy_maybe ty of + Just (arg_ty, _) -> isStateHackType arg_ty + Nothing -> False -- | Returns whether the lambda associated with the 'Id' is certainly applied at most once. -- You probably want to use 'isOneShotBndr' instead |