X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FnativeGen%2FRegLiveness.hs;h=fc8749c286207cf40c449dc6123357976d64cad6;hb=8480018a7f5f1cd961f3bd8ae758cc01910d5e6a;hp=98aefb09521dc7fa578f8544a238be5a7769c4a4;hpb=fd8d04119e849f9c713d3e697228846d93c5ca69;p=ghc-hetmet.git diff --git a/compiler/nativeGen/RegLiveness.hs b/compiler/nativeGen/RegLiveness.hs index 98aefb0..fc8749c 100644 --- a/compiler/nativeGen/RegLiveness.hs +++ b/compiler/nativeGen/RegLiveness.hs @@ -22,7 +22,7 @@ module RegLiveness ( stripLive, spillNatBlock, slurpConflicts, - lifetimeCount, + slurpReloadCoalesce, eraseDeltasLive, patchEraseLive, patchRegsLiveInstr, @@ -30,8 +30,7 @@ module RegLiveness ( ) where -#include "HsVersions.h" - +import BlockId import MachRegs import MachInstrs import PprMach @@ -46,6 +45,7 @@ import UniqFM import UniqSupply import Bag import State +import FastString import Data.List import Data.Maybe @@ -58,10 +58,10 @@ type RegMap a = UniqFM a emptyRegMap :: UniqFM a emptyRegMap = emptyUFM -type BlockMap a = UniqFM a +type BlockMap a = BlockEnv a -emptyBlockMap :: UniqFM a -emptyBlockMap = emptyUFM +emptyBlockMap :: BlockEnv a +emptyBlockMap = emptyBlockEnv -- | A top level thing which carries liveness information. @@ -112,9 +112,9 @@ instance Outputable LiveInstr where = ppr instr $$ (nest 8 $ vcat - [ pprRegs (ptext SLIT("# born: ")) (liveBorn live) - , pprRegs (ptext SLIT("# r_dying: ")) (liveDieRead live) - , pprRegs (ptext SLIT("# w_dying: ")) (liveDieWrite live) ] + [ pprRegs (ptext (sLit "# born: ")) (liveBorn live) + , pprRegs (ptext (sLit "# r_dying: ")) (liveDieRead live) + , pprRegs (ptext (sLit "# w_dying: ")) (liveDieWrite live) ] $+$ space) where pprRegs :: SDoc -> RegSet -> SDoc @@ -200,12 +200,12 @@ slurpConflicts live slurpBlock info rs (BasicBlock blockId instrs) | LiveInfo _ _ blockLive <- info - , Just rsLiveEntry <- lookupUFM blockLive blockId + , Just rsLiveEntry <- lookupBlockEnv blockLive blockId , (conflicts, moves) <- slurpLIs rsLiveEntry rs instrs = (consBag rsLiveEntry conflicts, moves) | otherwise - = error "RegLiveness.slurpBlock: bad block" + = panic "RegLiveness.slurpBlock: bad block" slurpLIs rsLive (conflicts, moves) [] = (consBag rsLive conflicts, moves) @@ -244,6 +244,100 @@ slurpConflicts live , moves) lis +-- | For spill\/reloads +-- +-- SPILL v1, slot1 +-- ... +-- RELOAD slot1, v2 +-- +-- If we can arrange that v1 and v2 are allocated to the same hreg it's more likely +-- the spill\/reload instrs can be cleaned and replaced by a nop reg-reg move. +-- +-- +slurpReloadCoalesce :: LiveCmmTop -> Bag (Reg, Reg) +slurpReloadCoalesce live + = slurpCmm emptyBag live + + where slurpCmm cs CmmData{} = cs + slurpCmm cs (CmmProc _ _ _ (ListGraph blocks)) + = foldl' slurpComp cs blocks + + slurpComp cs comp + = let (moveBags, _) = runState (slurpCompM comp) emptyUFM + in unionManyBags (cs : moveBags) + + slurpCompM (BasicBlock _ blocks) + = do -- run the analysis once to record the mapping across jumps. + mapM_ (slurpBlock False) blocks + + -- run it a second time while using the information from the last pass. + -- We /could/ run this many more times to deal with graphical control + -- flow and propagating info across multiple jumps, but it's probably + -- not worth the trouble. + mapM (slurpBlock True) blocks + + slurpBlock propagate (BasicBlock blockId instrs) + = do -- grab the slot map for entry to this block + slotMap <- if propagate + then getSlotMap blockId + else return emptyUFM + + (_, mMoves) <- mapAccumLM slurpLI slotMap instrs + return $ listToBag $ catMaybes mMoves + + slurpLI :: UniqFM Reg -- current slotMap + -> LiveInstr + -> State (UniqFM [UniqFM Reg]) -- blockId -> [slot -> reg] + -- for tracking slotMaps across jumps + + ( UniqFM Reg -- new slotMap + , Maybe (Reg, Reg)) -- maybe a new coalesce edge + + slurpLI slotMap (Instr instr _) + + -- remember what reg was stored into the slot + | SPILL reg slot <- instr + , slotMap' <- addToUFM slotMap slot reg + = return (slotMap', Nothing) + + -- add an edge betwen the this reg and the last one stored into the slot + | RELOAD slot reg <- instr + = case lookupUFM slotMap slot of + Just reg2 + | reg /= reg2 -> return (slotMap, Just (reg, reg2)) + | otherwise -> return (slotMap, Nothing) + + Nothing -> return (slotMap, Nothing) + + -- if we hit a jump, remember the current slotMap + | targets <- jumpDests instr [] + , not $ null targets + = do mapM_ (accSlotMap slotMap) targets + return (slotMap, Nothing) + + | otherwise + = return (slotMap, Nothing) + + -- record a slotmap for an in edge to this block + accSlotMap slotMap blockId + = modify (\s -> addToUFM_C (++) s blockId [slotMap]) + + -- work out the slot map on entry to this block + -- if we have slot maps for multiple in-edges then we need to merge them. + getSlotMap blockId + = do map <- get + let slotMaps = fromMaybe [] (lookupUFM map blockId) + return $ foldr mergeSlotMaps emptyUFM slotMaps + + mergeSlotMaps :: UniqFM Reg -> UniqFM Reg -> UniqFM Reg + mergeSlotMaps map1 map2 + = listToUFM + $ [ (k, r1) | (k, r1) <- ufmToList map1 + , case lookupUFM map2 k of + Nothing -> False + Just r2 -> r1 == r2 ] + + -- | Strip away liveness information, yielding NatCmmTop stripLive :: LiveCmmTop -> NatCmmTop @@ -252,7 +346,8 @@ stripLive live where stripCmm (CmmData sec ds) = CmmData sec ds stripCmm (CmmProc (LiveInfo info _ _) label params (ListGraph comps)) - = CmmProc info label params (ListGraph $ concatMap stripComp comps) + = CmmProc info label params + (ListGraph $ concatMap stripComp comps) stripComp (BasicBlock _ blocks) = map stripBlock blocks stripBlock (BasicBlock i instrs) = BasicBlock i (map stripLI instrs) @@ -286,48 +381,6 @@ spillNatBlock (BasicBlock i is) = spillNat (instr : acc) instrs --- | Slurp out a map of how many times each register was live upon entry to an instruction. - -lifetimeCount - :: LiveCmmTop - -> UniqFM (Reg, Int) -- ^ reg -> (reg, count) - -lifetimeCount cmm - = countCmm emptyUFM cmm - where - countCmm fm CmmData{} = fm - countCmm fm (CmmProc info _ _ (ListGraph blocks)) - = foldl' (countComp info) fm blocks - - countComp info fm (BasicBlock _ blocks) - = foldl' (countBlock info) fm blocks - - countBlock info fm (BasicBlock blockId instrs) - | LiveInfo _ _ blockLive <- info - , Just rsLiveEntry <- lookupUFM blockLive blockId - = countLIs rsLiveEntry fm instrs - - | otherwise - = error "RegLiveness.countBlock: bad block" - - countLIs _ fm [] = fm - countLIs rsLive fm (Instr _ Nothing : lis) = countLIs rsLive fm lis - - countLIs rsLiveEntry fm (Instr _ (Just live) : lis) - = let - rsLiveAcross = rsLiveEntry `minusUniqSet` (liveDieRead live) - - rsLiveNext = (rsLiveAcross `unionUniqSets` (liveBorn live)) - `minusUniqSet` (liveDieWrite live) - - add r fm = addToUFM_C - (\(r1, l1) (_, l2) -> (r1, l1 + l2)) - fm r (r, 1) - - fm' = foldUniqSet add fm rsLiveEntry - in countLIs rsLiveNext fm' lis - - -- | Erase Delta instructions. eraseDeltasLive :: LiveCmmTop -> LiveCmmTop @@ -359,7 +412,7 @@ patchEraseLive patchF cmm patchCmm (CmmProc info label params (ListGraph comps)) | LiveInfo static id blockMap <- info = let patchRegSet set = mkUniqSet $ map patchF $ uniqSetToList set - blockMap' = mapUFM patchRegSet blockMap + blockMap' = mapBlockEnv patchRegSet blockMap info' = LiveInfo static id blockMap' in CmmProc info' label params $ ListGraph $ map patchComp comps @@ -428,7 +481,7 @@ regLiveness (CmmData i d) regLiveness (CmmProc info lbl params (ListGraph [])) = returnUs $ CmmProc - (LiveInfo info Nothing emptyUFM) + (LiveInfo info Nothing emptyBlockEnv) lbl params (ListGraph []) regLiveness (CmmProc info lbl params (ListGraph blocks@(first : _))) @@ -444,13 +497,12 @@ regLiveness (CmmProc info lbl params (ListGraph blocks@(first : _))) -> panic "RegLiveness.regLiveness: no blocks in scc list") $ ann_sccs - in returnUs $ CmmProc - (LiveInfo info (Just first_id) block_live) - lbl params (ListGraph liveBlocks) + in returnUs $ CmmProc (LiveInfo info (Just first_id) block_live) + lbl params (ListGraph liveBlocks) sccBlocks :: [NatBasicBlock] -> [SCC NatBasicBlock] -sccBlocks blocks = stronglyConnComp graph +sccBlocks blocks = stronglyConnCompFromEdgedVertices graph where getOutEdges :: [Instr] -> [BlockId] getOutEdges instrs = foldl' (\a x -> jumpDests x a) [] instrs @@ -506,7 +558,7 @@ livenessSCCs blockmap done concatMap tail $ groupBy (\(a1, _) (a2, _) -> eq a1 a2) $ iterate (\(a, _) -> f a b) $ - (a, error "RegisterAlloc.livenessSCCs") + (a, panic "RegLiveness.livenessSCCs") linearLiveness :: BlockMap RegSet -> [NatBasicBlock] @@ -517,8 +569,8 @@ livenessSCCs blockmap done -- BlockMaps for equality. equalBlockMaps a b = a' == b' - where a' = map f $ ufmToList a - b' = map f $ ufmToList b + where a' = map f $ blockEnvToList a + b' = map f $ blockEnvToList b f (key,elt) = (key, uniqSetToList elt) @@ -534,7 +586,7 @@ livenessBlock blockmap (BasicBlock block_id instrs) = let (regsLiveOnEntry, instrs1) = livenessBack emptyUniqSet blockmap [] (reverse instrs) - blockmap' = addToUFM blockmap block_id regsLiveOnEntry + blockmap' = extendBlockEnv blockmap block_id regsLiveOnEntry instrs2 = livenessForward regsLiveOnEntry instrs1 @@ -634,9 +686,9 @@ liveness1 liveregs blockmap instr not_a_branch = null targets targetLiveRegs target - = case lookupUFM blockmap target of + = case lookupBlockEnv blockmap target of Just ra -> ra - Nothing -> emptyBlockMap + Nothing -> emptyRegMap live_from_branch = unionManyUniqSets (map targetLiveRegs targets)