X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FsimplCore%2FFloatIn.lhs;h=0dd318b4209cc856c0250f271d6f46ef54a4438c;hb=24b1e13657c3e06e7c97eeab9a6c4f2a0cdd9193;hp=4c39336777fb308135e35189bdad757fa247b3f3;hpb=17b297d97d327620ed6bfab942f8992b2446f1bf;p=ghc-hetmet.git diff --git a/compiler/simplCore/FloatIn.lhs b/compiler/simplCore/FloatIn.lhs index 4c39336..0dd318b 100644 --- a/compiler/simplCore/FloatIn.lhs +++ b/compiler/simplCore/FloatIn.lhs @@ -12,13 +12,6 @@ case, so that we don't allocate things, save them on the stack, and then discover that they aren't needed in the chosen branch. \begin{code} -{-# OPTIONS_GHC -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/WorkingConventions#Warnings --- for details - module FloatIn ( floatInwards ) where #include "HsVersions.h" @@ -28,11 +21,12 @@ import CoreSyn import CoreUtils ( exprIsHNF, exprIsDupable ) import CoreLint ( showPass, endPass ) import CoreFVs ( CoreExprWithFVs, freeVars, freeVarsOf, idRuleVars ) -import Id ( isOneShotBndr ) -import Var ( Id, idType ) +import Id ( isOneShotBndr, idType ) +import Var import Type ( isUnLiftedType ) import VarSet import Util ( zipEqual, zipWithEqual, count ) +import UniqFM import Outputable \end{code} @@ -149,7 +143,7 @@ fiExpr to_drop (_, AnnType ty) = ASSERT( null to_drop ) fiExpr to_drop (_, AnnCast expr co) = Cast (fiExpr to_drop expr) co -- Just float in past coercion -fiExpr to_drop (_, AnnLit lit) = Lit lit +fiExpr _ (_, AnnLit lit) = Lit lit \end{code} Applications: we do float inside applications, mainly because we @@ -213,7 +207,7 @@ We don't float lets inwards past an SCC. cc, change current cc to the new one and float binds into expr. \begin{code} -fiExpr to_drop (_, AnnNote note@(SCC cc) expr) +fiExpr to_drop (_, AnnNote note@(SCC _) expr) = -- Wimp out for now mkCoLets' to_drop (Note note (fiExpr [] expr)) @@ -297,21 +291,21 @@ fiExpr to_drop (_,AnnLet (AnnNonRec id rhs@(rhs_fvs, ann_rhs)) body) -- Push rhs_binds into the right hand side of the binding rhs' = fiExpr rhs_binds rhs - rhs_fvs' = rhs_fvs `unionVarSet` floatedBindsFVs rhs_binds + rhs_fvs' = rhs_fvs `unionVarSet` floatedBindsFVs rhs_binds `unionVarSet` rule_fvs + -- Don't forget the rule_fvs; the binding mentions them! fiExpr to_drop (_,AnnLet (AnnRec bindings) body) = fiExpr new_to_drop body where - rhss = map snd bindings - + (ids, rhss) = unzip bindings rhss_fvs = map freeVarsOf rhss body_fvs = freeVarsOf body -- See Note [extra_fvs (1,2)] - extra_fvs = foldr (unionVarSet . get_extras) emptyVarSet bindings - get_extras (id, (rhs_fvs, rhs)) - | noFloatIntoRhs rhs = idRuleVars id `unionVarSet` rhs_fvs - | otherwise = idRuleVars id + rule_fvs = foldr (unionVarSet . idRuleVars) emptyVarSet ids + extra_fvs = rule_fvs `unionVarSet` + unionVarSets [ fvs | (fvs, rhs) <- rhss + , noFloatIntoRhs rhs ] (shared_binds:extra_binds:body_binds:rhss_binds) = sepBindsByDropPoint False (extra_fvs:body_fvs:rhss_fvs) to_drop @@ -322,8 +316,9 @@ fiExpr to_drop (_,AnnLet (AnnRec bindings) body) extra_binds ++ -- Note [extra_fvs (1,2)] shared_binds -- Used in more than one place - rhs_fvs' = unionVarSet (unionVarSets rhss_fvs) - (unionVarSets (map floatedBindsFVs rhss_binds)) + rhs_fvs' = unionVarSets rhss_fvs `unionVarSet` + unionVarSets (map floatedBindsFVs rhss_binds) `unionVarSet` + rule_fvs -- Don't forget the rule variables! -- Push rhs_binds into the right hand side of the binding fi_bind :: [FloatingBinds] -- one per "drop pt" conjured w/ fvs_of_rhss @@ -355,12 +350,13 @@ fiExpr to_drop (_, AnnCase scrut case_bndr ty alts) scrut_fvs = freeVarsOf scrut alts_fvs = map alt_fvs alts all_alts_fvs = unionVarSets alts_fvs - alt_fvs (con, args, rhs) = foldl delVarSet (freeVarsOf rhs) (case_bndr:args) + alt_fvs (_con, args, rhs) = foldl delVarSet (freeVarsOf rhs) (case_bndr:args) -- Delete case_bndr and args from free vars of rhs -- to get free vars of alt fi_alt to_drop (con, args, rhs) = (con, args, fiExpr to_drop rhs) +noFloatIntoRhs :: AnnExpr' Var (UniqFM Var) -> Bool noFloatIntoRhs (AnnNote InlineMe _) = True noFloatIntoRhs (AnnLam b _) = not (is_one_shot b) -- IMPORTANT: don't say 'True' for a RHS with a one-shot lambda at the top. @@ -374,7 +370,8 @@ noFloatIntoRhs (AnnLam b _) = not (is_one_shot b) noFloatIntoRhs rhs = exprIsHNF (deAnnotate' rhs) -- We'd just float right back out again... -is_one_shot b = isId b && isOneShotBndr b +is_one_shot :: Var -> Bool +is_one_shot b = isIdVar b && isOneShotBndr b \end{code} @@ -416,8 +413,8 @@ sepBindsByDropPoint type DropBox = (FreeVarsSet, FloatingBinds) -sepBindsByDropPoint is_case drop_pts [] - = [] : [[] | p <- drop_pts] -- cut to the chase scene; it happens +sepBindsByDropPoint _is_case drop_pts [] + = [] : [[] | _ <- drop_pts] -- cut to the chase scene; it happens sepBindsByDropPoint is_case drop_pts floaters = go floaters (map (\fvs -> (fvs, [])) (emptyVarSet : drop_pts)) @@ -435,7 +432,7 @@ sepBindsByDropPoint is_case drop_pts floaters -- "here" means the group of bindings dropped at the top of the fork (used_here : used_in_flags) = [ any (`elemVarSet` fvs) (bindersOf bind) - | (fvs, drops) <- drop_boxes] + | (fvs, _) <- drop_boxes] drop_here = used_here || not can_push @@ -468,6 +465,8 @@ sepBindsByDropPoint is_case drop_pts floaters insert_maybe box True = insert box insert_maybe box False = box + go _ _ = panic "sepBindsByDropPoint/go" + floatedBindsFVs :: FloatingBinds -> FreeVarsSet floatedBindsFVs binds = unionVarSets (map snd binds) @@ -476,6 +475,7 @@ mkCoLets' :: FloatingBinds -> CoreExpr -> CoreExpr mkCoLets' to_drop e = foldl (flip (Let . fst)) e to_drop -- Remember to_drop is in *reverse* dependency order +bindIsDupable :: Bind CoreBndr -> Bool bindIsDupable (Rec prs) = all (exprIsDupable . snd) prs -bindIsDupable (NonRec b r) = exprIsDupable r +bindIsDupable (NonRec _ r) = exprIsDupable r \end{code}