Andreas Klebinger pushed to branch wip/andreask/occ_anal_tuning at Glasgow Haskell Compiler / GHC Commits: 2076be78 by Andreas Klebinger at 2025-10-08T09:13:36+02:00 OccAnal: Be stricter when combining usageDetails. In combineUsageDetails when combining the underlying adds we compute a new `LocalOcc` for each entry by combining the two existing ones. Rather than wait for those entries to be forced down the road we now force them immediately. Speeding up T26425 by about 10% with little effect on the common case. ------------------------- Metric Decrease: T26425 ------------------------- - - - - - 4 changed files: - compiler/GHC/Core/Opt/OccurAnal.hs - compiler/GHC/Data/Graph/UnVar.hs - compiler/GHC/Types/Unique/FM.hs - compiler/GHC/Types/Var/Env.hs Changes: ===================================== compiler/GHC/Core/Opt/OccurAnal.hs ===================================== @@ -9,6 +9,8 @@ -- many /other/ arguments the function has. Inconsistent unboxing is very -- bad for performance, so I increased the limit to allow it to unbox -- consistently. +-- AK: Seems we no longer unbox OccEnv now anyway so it might be redundant. + {- (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 @@ -62,6 +64,7 @@ import GHC.Utils.Misc import GHC.Builtin.Names( runRWKey ) import GHC.Unit.Module( Module ) +import GHC.Data.Graph.UnVar as UnVar import Data.List (mapAccumL) import Data.List.NonEmpty (NonEmpty (..)) @@ -984,7 +987,7 @@ occAnalBind !env lvl ire (NonRec bndr rhs) thing_inside combine = -- Analyse the RHS and /then/ the body let -- Analyse the rhs first, generating rhs_uds !(rhs_uds_s, bndr', rhs') = occAnalNonRecRhs env lvl ire mb_join bndr rhs - rhs_uds = foldr1 orUDs rhs_uds_s -- NB: orUDs. See (W4) of + rhs_uds = foldl1' orUDs rhs_uds_s -- NB: orUDs. See (W4) of -- Note [Occurrence analysis for join points] -- Now analyse the body, adding the join point @@ -3610,6 +3613,7 @@ localTailCallInfo :: LocalOcc -> TailCallInfo localTailCallInfo (OneOccL { lo_tail = tci }) = tci localTailCallInfo (ManyOccL tci) = tci +-- type ZappedSet = UnVar.UnVarSet -- Values are ignored type ZappedSet = OccInfoEnv -- Values are ignored data UsageDetails @@ -3650,8 +3654,8 @@ data WithTailUsageDetails a = WTUD !TailUsageDetails !a ------------------- -- UsageDetails API -andUDs, orUDs - :: UsageDetails -> UsageDetails -> UsageDetails +andUDs:: UsageDetails -> UsageDetails -> UsageDetails +orUDs :: UsageDetails -> UsageDetails -> UsageDetails andUDs = combineUsageDetailsWith andLocalOcc orUDs = combineUsageDetailsWith orLocalOcc @@ -3760,16 +3764,20 @@ restrictFreeVars bndrs fvs = restrictUniqSetToUFM bndrs fvs combineUsageDetailsWith :: (LocalOcc -> LocalOcc -> LocalOcc) -> UsageDetails -> UsageDetails -> UsageDetails {-# INLINE combineUsageDetailsWith #-} +{-# SCC combineUsageDetailsWith #-} combineUsageDetailsWith plus_occ_info uds1@(UD { ud_env = env1, ud_z_many = z_many1, ud_z_in_lam = z_in_lam1, ud_z_tail = z_tail1 }) uds2@(UD { ud_env = env2, ud_z_many = z_many2, ud_z_in_lam = z_in_lam2, ud_z_tail = z_tail2 }) | isEmptyVarEnv env1 = uds2 | isEmptyVarEnv env2 = uds1 | otherwise - = UD { ud_env = plusVarEnv_C plus_occ_info env1 env2 - , ud_z_many = plusVarEnv z_many1 z_many2 - , ud_z_in_lam = plusVarEnv z_in_lam1 z_in_lam2 - , ud_z_tail = plusVarEnv z_tail1 z_tail2 } + -- Typically we end up forcing those values later anyway. So we can avoid storking thunks retaining + -- the original LocalOcc by using a strict combination function here. The fields themselves are already + -- strict so no need to force those explicitly. + = UD { ud_env = {-# SCC ud_env #-} strictPlusVarEnv_C plus_occ_info env1 env2 + , ud_z_many = {-# SCC ud_z_many #-} strictPlusVarEnv z_many1 z_many2 + , ud_z_in_lam = {-# SCC ud_z_in_lam #-} strictPlusVarEnv z_in_lam1 z_in_lam2 + , ud_z_tail = {-# SCC ud_z_tail #-} strictPlusVarEnv z_tail1 z_tail2 } lookupLetOccInfo :: UsageDetails -> Id -> OccInfo -- Don't use locally-generated occ_info for exported (visible-elsewhere) ===================================== compiler/GHC/Data/Graph/UnVar.hs ===================================== @@ -17,8 +17,8 @@ equal to g, but twice as expensive and large. module GHC.Data.Graph.UnVar ( UnVarSet , emptyUnVarSet, mkUnVarSet, unionUnVarSet, unionUnVarSets - , extendUnVarSet, extendUnVarSetList, delUnVarSet, delUnVarSetList - , elemUnVarSet, isEmptyUnVarSet + , extendUnVarSet, extendUnVarSet_Directly, extendUnVarSetList, delUnVarSet, delUnVarSetList + , elemUnVarSet, elemUnVarSet_Directly, isEmptyUnVarSet , UnVarGraph , emptyUnVarGraph , unionUnVarGraph, unionUnVarGraphs @@ -60,6 +60,9 @@ emptyUnVarSet = UnVarSet S.empty elemUnVarSet :: Var -> UnVarSet -> Bool elemUnVarSet v (UnVarSet s) = k v `S.member` s +{-# INLINE elemUnVarSet_Directly #-} +elemUnVarSet_Directly :: Uniquable key => key -> UnVarSet -> Bool +elemUnVarSet_Directly v (UnVarSet s) = (getKey $ getUnique v) `S.member` s isEmptyUnVarSet :: UnVarSet -> Bool isEmptyUnVarSet (UnVarSet s) = S.null s @@ -82,6 +85,10 @@ mkUnVarSet vs = UnVarSet $ S.fromList $ map k vs extendUnVarSet :: Var -> UnVarSet -> UnVarSet extendUnVarSet v (UnVarSet s) = UnVarSet $ S.insert (k v) s +{-# INLINE extendUnVarSet_Directly #-} +extendUnVarSet_Directly :: Uniquable key => key -> UnVarSet -> UnVarSet +extendUnVarSet_Directly u (UnVarSet s) = UnVarSet $ S.insert (getKey $ getUnique u) s + extendUnVarSetList :: [Var] -> UnVarSet -> UnVarSet extendUnVarSetList vs s = s `unionUnVarSet` mkUnVarSet vs ===================================== compiler/GHC/Types/Unique/FM.hs ===================================== @@ -51,7 +51,9 @@ module GHC.Types.Unique.FM ( delListFromUFM, delListFromUFM_Directly, plusUFM, + strictPlusUFM, plusUFM_C, + strictPlusUFM_C, plusUFM_CD, plusUFM_CD2, mergeUFM, @@ -251,16 +253,24 @@ delListFromUFM_Directly = foldl' delFromUFM_Directly delFromUFM_Directly :: UniqFM key elt -> Unique -> UniqFM key elt delFromUFM_Directly (UFM m) u = UFM (M.delete (getKey u) m) --- Bindings in right argument shadow those in the left +-- | Bindings in right argument shadow those in the left. +-- +-- Unlike containers this union is right-biased for historic reasons. plusUFM :: UniqFM key elt -> UniqFM key elt -> UniqFM key elt --- M.union is left-biased, plusUFM should be right-biased. plusUFM (UFM x) (UFM y) = UFM (M.union y x) -- Note (M.union y x), with arguments flipped -- M.union is left-biased, plusUFM should be right-biased. +-- | Right biased +strictPlusUFM :: UniqFM key elt -> UniqFM key elt -> UniqFM key elt +strictPlusUFM (UFM x) (UFM y) = UFM (MS.union y x) + plusUFM_C :: (elt -> elt -> elt) -> UniqFM key elt -> UniqFM key elt -> UniqFM key elt plusUFM_C f (UFM x) (UFM y) = UFM (M.unionWith f x y) +strictPlusUFM_C :: (elt -> elt -> elt) -> UniqFM key elt -> UniqFM key elt -> UniqFM key elt +strictPlusUFM_C f (UFM x) (UFM y) = UFM (MS.unionWith f x y) + -- | `plusUFM_CD f m1 d1 m2 d2` merges the maps using `f` as the -- combinding function and `d1` resp. `d2` as the default value if -- there is no entry in `m1` reps. `m2`. The domain is the union of ===================================== compiler/GHC/Types/Var/Env.hs ===================================== @@ -12,7 +12,8 @@ module GHC.Types.Var.Env ( elemVarEnv, disjointVarEnv, anyVarEnv, extendVarEnv, extendVarEnv_C, extendVarEnv_Acc, extendVarEnvList, - plusVarEnv, plusVarEnv_C, plusVarEnv_CD, plusMaybeVarEnv_C, + strictPlusVarEnv, plusVarEnv, plusVarEnv_C, strictPlusVarEnv_C, + plusVarEnv_CD, plusMaybeVarEnv_C, plusVarEnvList, alterVarEnv, delVarEnvList, delVarEnv, minusVarEnv, @@ -511,6 +512,7 @@ extendVarEnv :: VarEnv a -> Var -> a -> VarEnv a extendVarEnv_C :: (a->a->a) -> VarEnv a -> Var -> a -> VarEnv a extendVarEnv_Acc :: (a->b->b) -> (a->b) -> VarEnv b -> Var -> a -> VarEnv b plusVarEnv :: VarEnv a -> VarEnv a -> VarEnv a +strictPlusVarEnv :: VarEnv a -> VarEnv a -> VarEnv a plusVarEnvList :: [VarEnv a] -> VarEnv a extendVarEnvList :: VarEnv a -> [(Var, a)] -> VarEnv a varEnvDomain :: VarEnv elt -> UnVarSet @@ -522,6 +524,7 @@ delVarEnvList :: Foldable f => VarEnv a -> f Var -> VarEnv a delVarEnv :: VarEnv a -> Var -> VarEnv a minusVarEnv :: VarEnv a -> VarEnv b -> VarEnv a plusVarEnv_C :: (a -> a -> a) -> VarEnv a -> VarEnv a -> VarEnv a +strictPlusVarEnv_C :: (a -> a -> a) -> VarEnv a -> VarEnv a -> VarEnv a plusVarEnv_CD :: (a -> a -> a) -> VarEnv a -> a -> VarEnv a -> a -> VarEnv a plusMaybeVarEnv_C :: (a -> a -> Maybe a) -> VarEnv a -> VarEnv a -> VarEnv a mapVarEnv :: (a -> b) -> VarEnv a -> VarEnv b @@ -548,6 +551,7 @@ extendVarEnv_C = addToUFM_C extendVarEnv_Acc = addToUFM_Acc extendVarEnvList = addListToUFM plusVarEnv_C = plusUFM_C +strictPlusVarEnv_C = strictPlusUFM_C plusVarEnv_CD = plusUFM_CD plusMaybeVarEnv_C = plusMaybeUFM_C delVarEnvList = delListFromUFM @@ -556,6 +560,7 @@ delVarEnvList = delListFromUFM delVarEnv = delFromUFM minusVarEnv = minusUFM plusVarEnv = plusUFM +strictPlusVarEnv = strictPlusUFM plusVarEnvList = plusUFMList -- lookupVarEnv is very hot (in part due to being called by substTyVar), -- if it's not inlined than the mere allocation of the Just constructor causes View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/2076be78cec3f31fac74492e63922ecc... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/2076be78cec3f31fac74492e63922ecc... 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