Bartosz Why not just cache the #datacons in the TyCon (in the DataTyCon constructor). That seems simple, direct, and fast.
And simpler than the stuff you are forced into here. Simon | -----Original Message----- | From: ghc-commits [mailto:ghc-commits-boun...@haskell.org] On Behalf Of | g...@git.haskell.org | Sent: 27 October 2017 23:03 | To: ghc-comm...@haskell.org | Subject: [commit: ghc] master: Make tagForCon non-linear (faf60e8) | | Repository : ssh://g...@git.haskell.org/ghc | | On branch : master | Link : | https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fghc.haske | ll.org%2Ftrac%2Fghc%2Fchangeset%2Ffaf60e858a293affca463043c830e1edb568500 | 3%2Fghc&data=02%7C01%7Csimonpj%40microsoft.com%7C677da6a867674476306508d5 | 1d869247%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636447386176303711& | sdata=tp4PTSkN5iBwKkWgZdT%2BcHKK8EKz8NQZeE%2FegVdx%2FIM%3D&reserved=0 | | >--------------------------------------------------------------- | | commit faf60e858a293affca463043c830e1edb5685003 | Author: Bartosz Nitka <bni...@fb.com> | Date: Fri Oct 20 20:30:52 2017 +0100 | | Make tagForCon non-linear | | Computing the number of constructors for TyCon is linear | in the number of constructors. | That's wasteful if all you want to check is if that | number is smaller than what fits in tag bits | (usually 8 things). | | What this change does is to use a function that can | determine the ineqaulity without computing the size. | | This improves compile time on a module with a | data type that has 10k constructors. | The variance in total time is (suspiciously) high, | but going by the best of 3 the numbers are 8.186s vs 7.511s. | For 1000 constructors the difference isn't noticeable: | 0.646s vs 0.624s. | The hot spots were cgDataCon and cgEnumerationTyCon | where tagForCon is called in a loop. | | One alternative would be to pass down the size. | | Test Plan: harbormaster | | Reviewers: bgamari, simonmar, austin | | Reviewed By: simonmar | | Subscribers: rwbarton, thomie | | Differential Revision: https://phabricator.haskell.org/D4116 | | | >--------------------------------------------------------------- | | faf60e858a293affca463043c830e1edb5685003 | compiler/codeGen/StgCmmClosure.hs | 11 ++++++++--- | compiler/types/TyCon.hs | 16 +++++++++++++++- | 2 files changed, 23 insertions(+), 4 deletions(-) | | diff --git a/compiler/codeGen/StgCmmClosure.hs | b/compiler/codeGen/StgCmmClosure.hs | index 1da1f70..2501ec9 100644 | --- a/compiler/codeGen/StgCmmClosure.hs | +++ b/compiler/codeGen/StgCmmClosure.hs | @@ -361,13 +361,18 @@ type DynTag = Int -- The tag on a *pointer* | isSmallFamily :: DynFlags -> Int -> Bool isSmallFamily dflags fam_size | = fam_size <= mAX_PTR_TAG dflags | | +-- | Faster version of isSmallFamily if you haven't computed the size | yet. | +isSmallFamilyTyCon :: DynFlags -> TyCon -> Bool isSmallFamilyTyCon | +dflags tycon = | + tyConFamilySizeAtMost tycon (mAX_PTR_TAG dflags) | + | tagForCon :: DynFlags -> DataCon -> DynTag tagForCon dflags con | - | isSmallFamily dflags fam_size = con_tag | - | otherwise = 1 | + | isSmallFamilyTyCon dflags tycon = con_tag | + | otherwise = 1 | where | con_tag = dataConTag con -- NB: 1-indexed | - fam_size = tyConFamilySize (dataConTyCon con) | + tycon = dataConTyCon con | | tagForArity :: DynFlags -> RepArity -> DynTag tagForArity dflags arity | diff --git a/compiler/types/TyCon.hs b/compiler/types/TyCon.hs index | 39d2e9b..103c824 100644 | --- a/compiler/types/TyCon.hs | +++ b/compiler/types/TyCon.hs | @@ -78,7 +78,7 @@ module TyCon( | tyConDataCons, tyConDataCons_maybe, | tyConSingleDataCon_maybe, tyConSingleDataCon, | tyConSingleAlgDataCon_maybe, | - tyConFamilySize, | + tyConFamilySize, tyConFamilySizeAtMost, | tyConStupidTheta, | tyConArity, | tyConRoles, | @@ -2205,6 +2205,20 @@ tyConFamilySize tc@(AlgTyCon { algTcRhs = rhs }) | _ -> pprPanic "tyConFamilySize 1" | (ppr tc) | tyConFamilySize tc = pprPanic "tyConFamilySize 2" (ppr tc) | | +-- | Determine if number of value constructors a 'TyCon' has is smaller | +-- than n. Faster than tyConFamilySize tc <= n. | +-- Panics if the 'TyCon' is not algebraic or a tuple | +tyConFamilySizeAtMost :: TyCon -> Int -> Bool tyConFamilySizeAtMost | +tc@(AlgTyCon { algTcRhs = rhs }) n | + = case rhs of | + DataTyCon { data_cons = cons } -> lengthAtMost cons n | + NewTyCon {} -> 1 <= n | + TupleTyCon {} -> 1 <= n | + SumTyCon { data_cons = cons } -> lengthAtMost cons n | + _ -> pprPanic "tyConFamilySizeAtMost | 1" | + (ppr tc) | +tyConFamilySizeAtMost tc _ = pprPanic "tyConFamilySizeAtMost 2" (ppr | +tc) | + | -- | Extract an 'AlgTyConRhs' with information about data constructors | from an | -- algebraic or tuple 'TyCon'. Panics for any other sort of 'TyCon' | algTyConRhs :: TyCon -> AlgTyConRhs | | _______________________________________________ | ghc-commits mailing list | ghc-comm...@haskell.org | https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fmail.hask | ell.org%2Fcgi-bin%2Fmailman%2Flistinfo%2Fghc- | commits&data=02%7C01%7Csimonpj%40microsoft.com%7C677da6a867674476306508d5 | 1d869247%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636447386176313720& | sdata=NfTqei3XryWnCiNRgOZDT6XfMRMfAST7EKFBSi%2FCXa8%3D&reserved=0 _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
