X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fcmm%2FCmmSpillReload.hs;h=1cdafa9baa335446cb5ce693f0d51980859db6e8;hb=c6206fd81612e51e257a650390646421c7c1d1cb;hp=67cf8d31df38b7a31740a8af08f5874cae596851;hpb=176fa33f17dd78355cc572e006d2ab26898e2c69;p=ghc-hetmet.git diff --git a/compiler/cmm/CmmSpillReload.hs b/compiler/cmm/CmmSpillReload.hs index 67cf8d3..1cdafa9 100644 --- a/compiler/cmm/CmmSpillReload.hs +++ b/compiler/cmm/CmmSpillReload.hs @@ -8,7 +8,6 @@ module CmmSpillReload , availRegsLattice , cmmAvailableReloads , insertLateReloads - , insertLateReloads' , removeDeadAssignmentsAndReloads ) where @@ -19,20 +18,17 @@ import CmmTx import CmmLiveZ import DFMonad import MkZipCfg -import OptimizationFuel import PprCmm() import ZipCfg import ZipCfgCmmRep import ZipDataflow -import Maybes -import Monad +import Control.Monad import Outputable hiding (empty) import qualified Outputable as PP -import Panic import UniqSet -import Maybe +import Data.Maybe import Prelude hiding (zip) -- The point of this module is to insert spills and reloads to @@ -63,12 +59,12 @@ dualUnionList ls = DualLive ss rs changeStack, changeRegs :: (RegSet -> RegSet) -> DualLive -> DualLive changeStack f live = live { on_stack = f (on_stack live) } -changeRegs f live = live { in_regs = f (in_regs live) } +changeRegs f live = live { in_regs = f (in_regs live) } dualLiveLattice :: DataflowLattice DualLive dualLiveLattice = - DataflowLattice "variables live in registers and on stack" empty add True + DataflowLattice "variables live in registers and on stack" empty add False where empty = DualLive emptyRegSet emptyRegSet -- | compute in the Tx monad to track whether anything has changed add new old = do stack <- add1 (on_stack new) (on_stack old) @@ -79,33 +75,37 @@ dualLiveLattice = type LiveReloadFix a = FuelMonad (BackwardFixedPoint Middle Last DualLive a) dualLivenessWithInsertion :: BlockSet -> (LGraph Middle Last) -> FuelMonad (LGraph Middle Last) -dualLivenessWithInsertion procPoints g = +dualLivenessWithInsertion procPoints g@(LGraph entry _) = liftM zdfFpContents $ (res :: LiveReloadFix (LGraph Middle Last)) where res = zdfBRewriteFromL RewriteDeep emptyBlockEnv "dual liveness with insertion" - dualLiveLattice (dualLiveTransfers procPoints) - (insertSpillAndReloadRewrites procPoints) empty g + dualLiveLattice (dualLiveTransfers entry procPoints) + (insertSpillAndReloadRewrites entry procPoints) empty g empty = fact_bot dualLiveLattice dualLiveness :: BlockSet -> LGraph Middle Last -> FuelMonad (BlockEnv DualLive) -dualLiveness procPoints g = liftM zdfFpFacts $ (res :: LiveReloadFix ()) +dualLiveness procPoints g@(LGraph entry _) = + liftM zdfFpFacts $ (res :: LiveReloadFix ()) where res = zdfSolveFromL emptyBlockEnv "dual liveness" dualLiveLattice - (dualLiveTransfers procPoints) empty g + (dualLiveTransfers entry procPoints) empty g empty = fact_bot dualLiveLattice -dualLiveTransfers :: BlockSet -> BackwardTransfers Middle Last DualLive -dualLiveTransfers procPoints = BackwardTransfers first middle last +dualLiveTransfers :: BlockId -> BlockSet -> BackwardTransfers Middle Last DualLive +dualLiveTransfers entry procPoints = BackwardTransfers first middle last where last = lastDualLiveness middle = middleDualLiveness - first live _id = - if elemBlockSet _id procPoints then -- live at procPoint => spill + first id live = check live id $ -- live at procPoint => spill + if id /= entry && elemBlockSet id procPoints then DualLive { on_stack = on_stack live `plusRegSet` in_regs live , in_regs = emptyRegSet } else live + check live id x = if id == entry then noLiveOnEntry id (in_regs live) x else x -middleDualLiveness :: DualLive -> Middle -> DualLive -middleDualLiveness live m = - changeStack updSlots $ changeRegs (middleLiveness m) live - where updSlots live = foldSlotsUsed reload (foldSlotsDefd spill live m) m +middleDualLiveness :: Middle -> DualLive -> DualLive +middleDualLiveness m live = + changeStack updSlots $ changeRegs (middleLiveness m) (changeRegs regs_in live) + where regs_in live = case m of MidForeignCall {} -> emptyRegSet + _ -> live + updSlots live = foldSlotsUsed reload (foldSlotsDefd spill live m) m spill live s@(RegSlot r, _, _) = check s $ deleteFromRegSet live r spill live _ = live reload live s@(RegSlot r, _, _) = check s $ extendRegSet live r @@ -114,42 +114,44 @@ middleDualLiveness live m = | o == w && w == widthInBytes (typeWidth ty) = x check _ _ = panic "middleDualLiveness unsupported: slices" -lastDualLiveness :: (BlockId -> DualLive) -> Last -> DualLive -lastDualLiveness env l = last l - where last (LastReturn _) = empty - last (LastJump e _) = changeRegs (gen e) empty - last (LastBranch id) = env id - last (LastCall tgt Nothing _) = changeRegs (gen tgt) empty - last (LastCall tgt (Just k) _) = - -- nothing can be live in registers at this point - let live = env k in - if isEmptyUniqSet (in_regs live) then - DualLive (on_stack live) (gen tgt emptyRegSet) - else - pprTrace "Offending party:" (ppr k <+> ppr live) $ - panic "live values in registers at call continuation" - last (LastCondBranch e t f) = changeRegs (gen e) $ dualUnion (env t) (env f) - last (LastSwitch e tbl) = changeRegs (gen e) $ dualUnionList $ +lastDualLiveness :: Last -> (BlockId -> DualLive) -> DualLive +lastDualLiveness l env = last l + where last (LastBranch id) = env id + last l@(LastCall _ Nothing _ _ _) = changeRegs (gen l . kill l) empty + last l@(LastCall _ (Just k) _ _ _) = + -- nothing can be live in registers at this point, unless safe foreign call + let live = env k + live_in = DualLive (on_stack live) (gen l emptyRegSet) + in if isEmptyUniqSet (in_regs live) then live_in + else pprTrace "Offending party:" (ppr k <+> ppr live) $ + panic "live values in registers at call continuation" + last l@(LastCondBranch _ t f) = + changeRegs (gen l . kill l) $ dualUnion (env t) (env f) + last l@(LastSwitch _ tbl) = changeRegs (gen l . kill l) $ dualUnionList $ map env (catMaybes tbl) empty = fact_bot dualLiveLattice -gen :: UserOfLocalRegs a => a -> RegSet -> RegSet -gen a live = foldRegsUsed extendRegSet live a - -insertSpillAndReloadRewrites :: BlockSet -> BackwardRewrites Middle Last DualLive -insertSpillAndReloadRewrites procPoints = BackwardRewrites first middle last exit +gen :: UserOfLocalRegs a => a -> RegSet -> RegSet +gen a live = foldRegsUsed extendRegSet live a +kill :: DefinerOfLocalRegs a => a -> RegSet -> RegSet +kill a live = foldRegsDefd deleteFromRegSet live a + +insertSpillAndReloadRewrites :: + BlockId -> BlockSet -> BackwardRewrites Middle Last DualLive +insertSpillAndReloadRewrites entry procPoints = + BackwardRewrites first middle last exit where middle = middleInsertSpillsAndReloads - last = \_ _ -> Nothing - exit = Nothing - first live id = - if elemBlockSet id procPoints && not (isEmptyUniqSet reloads) then - Just $ mkMiddles $ map reload $ uniqSetToList reloads + last _ _ = Nothing + exit = Nothing + first id live = + if id /= entry && elemBlockSet id procPoints then + case map reload (uniqSetToList (in_regs live)) of + [] -> Nothing + is -> Just (mkMiddles is) else Nothing - where reloads = in_regs live - -middleInsertSpillsAndReloads :: DualLive -> Middle -> Maybe (AGraph Middle Last) -middleInsertSpillsAndReloads live m = middle m +middleInsertSpillsAndReloads :: Middle -> DualLive -> Maybe (AGraph Middle Last) +middleInsertSpillsAndReloads m live = middle m where middle (MidAssign (CmmLocal reg) (CmmLoad (CmmStackSlot (RegSlot reg') _) _)) | reg == reg' = Nothing middle (MidAssign (CmmLocal reg) _) = @@ -158,6 +160,11 @@ middleInsertSpillsAndReloads live m = middle m text "after", ppr m]) $ Just $ mkMiddles $ [m, spill reg] else Nothing + middle (MidForeignCall _ _ fs _) = + case map spill (filter (flip elemRegSet (on_stack live)) fs) ++ + map reload (uniqSetToList (kill fs (in_regs live))) of + [] -> Nothing + reloads -> Just (mkMiddles (m : reloads)) middle _ = Nothing -- Generating spill and reload code @@ -168,13 +175,6 @@ spill, reload :: LocalReg -> Middle spill r = MidStore (regSlot r) (CmmReg $ CmmLocal r) reload r = MidAssign (CmmLocal r) (CmmLoad (regSlot r) $ localRegType r) -spillHead :: ZHead Middle -> RegSet -> ZHead Middle -reloadTail :: RegSet -> ZTail Middle Last -> ZTail Middle Last -spillHead h regset = foldl spl h $ uniqSetToList regset - where spl h r = ZHead h $ spill r -reloadTail regset t = foldl rel t $ uniqSetToList regset - where rel t r = ZTail (reload r) t - ---------------------------------------------------------------- --- sinking reloads @@ -190,7 +190,6 @@ data AvailRegs = UniverseMinus RegSet availRegsLattice :: DataflowLattice AvailRegs availRegsLattice = DataflowLattice "register gotten from reloads" empty add False - -- last True <==> debugging on where empty = UniverseMinus emptyRegSet -- | compute in the Tx monad to track whether anything has changed add new old = @@ -210,110 +209,79 @@ smallerAvail (UniverseMinus _) (AvailRegs _) = False smallerAvail (AvailRegs s) (AvailRegs s') = sizeUniqSet s < sizeUniqSet s' smallerAvail (UniverseMinus s) (UniverseMinus s') = sizeUniqSet s > sizeUniqSet s' ---extendAvail :: AvailRegs -> LocalReg -> AvailRegs ---extendAvail (UniverseMinus s) r = UniverseMinus (deleteFromRegSet s r) ---extendAvail (AvailRegs s) r = AvailRegs (extendRegSet s r) +extendAvail :: AvailRegs -> LocalReg -> AvailRegs +extendAvail (UniverseMinus s) r = UniverseMinus (deleteFromRegSet s r) +extendAvail (AvailRegs s) r = AvailRegs (extendRegSet s r) -deleteFromAvail :: AvailRegs -> LocalReg -> AvailRegs -deleteFromAvail (UniverseMinus s) r = UniverseMinus (extendRegSet s r) -deleteFromAvail (AvailRegs s) r = AvailRegs (deleteFromRegSet s r) +delFromAvail :: AvailRegs -> LocalReg -> AvailRegs +delFromAvail (UniverseMinus s) r = UniverseMinus (extendRegSet s r) +delFromAvail (AvailRegs s) r = AvailRegs (deleteFromRegSet s r) elemAvail :: AvailRegs -> LocalReg -> Bool elemAvail (UniverseMinus s) r = not $ elemRegSet r s elemAvail (AvailRegs s) r = elemRegSet r s -type CmmAvail = BlockEnv AvailRegs type AvailFix = FuelMonad (ForwardFixedPoint Middle Last AvailRegs ()) -cmmAvailableReloads :: LGraph Middle Last -> FuelMonad CmmAvail +cmmAvailableReloads :: LGraph Middle Last -> FuelMonad (BlockEnv AvailRegs) cmmAvailableReloads g = liftM zdfFpFacts $ (res :: AvailFix) where res = zdfSolveFromL emptyBlockEnv "available reloads" availRegsLattice avail_reloads_transfer empty g - empty = (fact_bot availRegsLattice) + empty = fact_bot availRegsLattice avail_reloads_transfer :: ForwardTransfers Middle Last AvailRegs -avail_reloads_transfer = ForwardTransfers first middle last id - where first avail _ = avail - middle = flip middleAvail - last = lastAvail - --- | The transfer equations use the traditional 'gen' and 'kill' --- notations, which should be familiar from the dragon book. ---agen, -akill :: UserOfLocalRegs a => a -> AvailRegs -> AvailRegs ---agen a live = foldRegsUsed extendAvail live a -akill a live = foldRegsUsed deleteFromAvail live a - --- Note: you can't sink the reload past a use. +avail_reloads_transfer = ForwardTransfers (flip const) middleAvail lastAvail id + middleAvail :: Middle -> AvailRegs -> AvailRegs -middleAvail m = middle m - where middle m live = middle' m $ foldRegsUsed deleteFromAvail live m - middle' (MidComment {}) = id - middle' (MidAssign lhs _expr) = akill lhs - middle' (MidStore {}) = id - middle' (MidUnsafeCall _tgt ress _args) = akill ress - middle' (MidAddToContext {}) = id - -lastAvail :: AvailRegs -> Last -> LastOutFacts AvailRegs -lastAvail _ (LastCall _ (Just k) _) = LastOutFacts [(k, AvailRegs emptyRegSet)] -lastAvail avail l = LastOutFacts $ map (\id -> (id, avail)) $ succs l - -insertLateReloads :: LGraph Middle Last -> FuelMonad (LGraph Middle Last) -insertLateReloads g = - do env <- cmmAvailableReloads g - mapM_blocks (insertM env) g - where insertM env b = fuelConsumingPass "late reloads" (insert b) - where avail id = lookupBlockEnv env id `orElse` AvailRegs emptyRegSet - insert (Block id off tail) fuel = - propagate (ZFirst id off) (avail id) tail fuel - propagate h avail (ZTail m t) fuel = - let (h', fuel') = maybe_add_reload h avail m fuel in - propagate (ZHead h' m) (middleAvail m avail) t fuel' - propagate h avail (ZLast l) fuel = - let (h', fuel') = maybe_add_reload h avail l fuel in - (zipht h' (ZLast l), fuel') - maybe_add_reload h avail node fuel = - let used = filterRegsUsed (elemAvail avail) node - in if not (canRewriteWithFuel fuel) || isEmptyUniqSet used - then (h,fuel) - else (spillHead h used, oneLessFuel fuel) - -type LateReloadFix = FuelMonad (ForwardFixedPoint Middle Last AvailRegs (LGraph Middle Last)) - -insertLateReloads' :: (LGraph Middle Last) -> FuelMonad (LGraph Middle Last) -insertLateReloads' g = liftM zdfFpContents $ (res :: LateReloadFix) +middleAvail (MidAssign (CmmLocal r) (CmmLoad l _)) avail + | l `isStackSlotOf` r = extendAvail avail r +middleAvail (MidAssign lhs _) avail = foldRegsDefd delFromAvail avail lhs +middleAvail (MidStore l (CmmReg (CmmLocal r))) avail + | l `isStackSlotOf` r = avail +middleAvail (MidStore (CmmStackSlot (RegSlot r) _) _) avail = delFromAvail avail r +middleAvail (MidStore {}) avail = avail +middleAvail (MidForeignCall {}) _ = AvailRegs emptyRegSet +middleAvail (MidComment {}) avail = avail + +lastAvail :: Last -> AvailRegs -> LastOutFacts AvailRegs +lastAvail (LastCall _ (Just k) _ _ _) _ = LastOutFacts [(k, AvailRegs emptyRegSet)] +lastAvail l avail = LastOutFacts $ map (\id -> (id, avail)) $ succs l + +type LateReloadFix = FuelMonad (ForwardFixedPoint Middle Last AvailRegs CmmGraph) + +availRewrites :: ForwardRewrites Middle Last AvailRegs +availRewrites = ForwardRewrites first middle last exit + where first _ _ = Nothing + middle m avail = maybe_reload_before avail m (mkMiddle m) + last l avail = maybe_reload_before avail l (mkLast l) + exit _ = Nothing + maybe_reload_before avail node tail = + let used = filterRegsUsed (elemAvail avail) node + in if isEmptyUniqSet used then Nothing + else Just $ reloadTail used tail + reloadTail regset t = foldl rel t $ uniqSetToList regset + where rel t r = mkMiddle (reload r) <*> t + + +insertLateReloads :: (LGraph Middle Last) -> FuelMonad (LGraph Middle Last) +insertLateReloads g = liftM zdfFpContents $ (res :: LateReloadFix) where res = zdfFRewriteFromL RewriteShallow emptyBlockEnv "insert late reloads" - availRegsLattice avail_reloads_transfer rewrites bot g + availRegsLattice avail_reloads_transfer availRewrites bot g bot = fact_bot availRegsLattice - rewrites = ForwardRewrites first middle last exit - first _ _ = Nothing - middle :: AvailRegs -> Middle -> Maybe (AGraph Middle Last) - last :: AvailRegs -> Last -> Maybe (AGraph Middle Last) - middle avail m = maybe_reload_before avail m (ZTail m (ZLast LastExit)) - last avail l = maybe_reload_before avail l (ZLast (LastOther l)) - exit _ = Nothing - maybe_reload_before avail node tail = - let used = filterRegsUsed (elemAvail avail) node - in if isEmptyUniqSet used then Nothing - else Just $ mkZTail $ reloadTail used tail removeDeadAssignmentsAndReloads :: BlockSet -> (LGraph Middle Last) -> FuelMonad (LGraph Middle Last) -removeDeadAssignmentsAndReloads procPoints g = +removeDeadAssignmentsAndReloads procPoints g@(LGraph entry _) = liftM zdfFpContents $ (res :: LiveReloadFix (LGraph Middle Last)) where res = zdfBRewriteFromL RewriteDeep emptyBlockEnv "dead-assignment & -reload elim" - dualLiveLattice (dualLiveTransfers procPoints) + dualLiveLattice (dualLiveTransfers entry procPoints) rewrites (fact_bot dualLiveLattice) g - rewrites = BackwardRewrites first middle last exit - exit = Nothing - last = \_ _ -> Nothing - middle = middleRemoveDeads - first _ _ = Nothing - -middleRemoveDeads :: DualLive -> Middle -> Maybe (AGraph Middle Last) -middleRemoveDeads live m = middle m - where middle (MidAssign (CmmLocal reg') _) - | not (reg' `elemRegSet` in_regs live) = Just emptyAGraph - middle _ = Nothing + rewrites = BackwardRewrites nothing middleRemoveDeads nothing Nothing + nothing _ _ = Nothing + +middleRemoveDeads :: Middle -> DualLive -> Maybe (AGraph Middle Last) +middleRemoveDeads (MidAssign (CmmLocal reg') _) live + | not (reg' `elemRegSet` in_regs live) = Just emptyAGraph +middleRemoveDeads _ _ = Nothing