X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FnativeGen%2FRegAlloc%2FGraph%2FSpillClean.hs;h=4f129c468a99bfbfaccb7db0eb99da4c6ba8fae3;hb=b04a210e26ca57242fd052f2aa91011a80b76299;hp=ac46b99892f520ed143cb1cfb6e40e3938174881;hpb=a12e845684c10955bc594cdb20d1f13fae14873d;p=ghc-hetmet.git diff --git a/compiler/nativeGen/RegAlloc/Graph/SpillClean.hs b/compiler/nativeGen/RegAlloc/Graph/SpillClean.hs index ac46b99..4f129c4 100644 --- a/compiler/nativeGen/RegAlloc/Graph/SpillClean.hs +++ b/compiler/nativeGen/RegAlloc/Graph/SpillClean.hs @@ -29,13 +29,12 @@ module RegAlloc.Graph.SpillClean ( ) where +import RegAlloc.Liveness +import Instruction +import Reg + import BlockId -import RegLiveness -import RegAllocInfo -import Regs -import Instrs import Cmm - import UniqSet import UniqFM import Unique @@ -51,12 +50,19 @@ type Slot = Int -- | Clean out unneeded spill\/reloads from this top level thing. -cleanSpills :: LiveCmmTop -> LiveCmmTop +cleanSpills + :: Instruction instr + => LiveCmmTop instr -> LiveCmmTop instr + cleanSpills cmm = evalState (cleanSpin 0 cmm) initCleanS -- | do one pass of cleaning -cleanSpin :: Int -> LiveCmmTop -> CleanM LiveCmmTop +cleanSpin + :: Instruction instr + => Int + -> LiveCmmTop instr + -> CleanM (LiveCmmTop instr) {- cleanSpin spinCount code @@ -103,7 +109,11 @@ cleanSpin spinCount code -- | Clean one basic block -cleanBlockForward :: LiveBasicBlock -> CleanM LiveBasicBlock +cleanBlockForward + :: Instruction instr + => LiveBasicBlock instr + -> CleanM (LiveBasicBlock instr) + cleanBlockForward (BasicBlock blockId instrs) = do -- see if we have a valid association for the entry to this block @@ -116,7 +126,11 @@ cleanBlockForward (BasicBlock blockId instrs) return $ BasicBlock blockId instrs_reload -cleanBlockBackward :: LiveBasicBlock -> CleanM LiveBasicBlock +cleanBlockBackward + :: Instruction instr + => LiveBasicBlock instr + -> CleanM (LiveBasicBlock instr) + cleanBlockBackward (BasicBlock blockId instrs) = do instrs_spill <- cleanBackward emptyUniqSet [] instrs return $ BasicBlock blockId instrs_spill @@ -130,11 +144,12 @@ cleanBlockBackward (BasicBlock blockId instrs) -- then we don't need to do the reload. -- cleanForward - :: BlockId -- ^ the block that we're currently in - -> Assoc Store -- ^ two store locations are associated if they have the same value - -> [LiveInstr] -- ^ acc - -> [LiveInstr] -- ^ instrs to clean (in backwards order) - -> CleanM [LiveInstr] -- ^ cleaned instrs (in forward order) + :: Instruction instr + => BlockId -- ^ the block that we're currently in + -> Assoc Store -- ^ two store locations are associated if they have the same value + -> [LiveInstr instr] -- ^ acc + -> [LiveInstr instr] -- ^ instrs to clean (in backwards order) + -> CleanM [LiveInstr instr] -- ^ cleaned instrs (in forward order) cleanForward _ _ acc [] = return acc @@ -142,19 +157,19 @@ cleanForward _ _ acc [] -- write out live range joins via spill slots to just a spill and a reg-reg move -- hopefully the spill will be also be cleaned in the next pass -- -cleanForward blockId assoc acc (Instr i1 live1 : Instr i2 _ : instrs) +cleanForward blockId assoc acc (li1 : li2 : instrs) - | SPILL reg1 slot1 <- i1 - , RELOAD slot2 reg2 <- i2 + | SPILL reg1 slot1 <- li1 + , RELOAD slot2 reg2 <- li2 , slot1 == slot2 = do modify $ \s -> s { sCleanedReloadsAcc = sCleanedReloadsAcc s + 1 } cleanForward blockId assoc acc - (Instr i1 live1 : Instr (mkRegRegMoveInstr reg1 reg2) Nothing : instrs) + (li1 : Instr (mkRegRegMoveInstr reg1 reg2) Nothing : instrs) cleanForward blockId assoc acc (li@(Instr i1 _) : instrs) - | Just (r1, r2) <- isRegRegMove i1 + | Just (r1, r2) <- takeRegRegMoveInstr i1 = if r1 == r2 -- erase any left over nop reg reg moves while we're here -- this will also catch any nop moves that the "write out live range joins" case above @@ -170,38 +185,50 @@ cleanForward blockId assoc acc (li@(Instr i1 _) : instrs) cleanForward blockId assoc' (li : acc) instrs -cleanForward blockId assoc acc (li@(Instr instr _) : instrs) +cleanForward blockId assoc acc (li : instrs) -- update association due to the spill - | SPILL reg slot <- instr + | SPILL reg slot <- li = let assoc' = addAssoc (SReg reg) (SSlot slot) $ delAssoc (SSlot slot) $ assoc in cleanForward blockId assoc' (li : acc) instrs -- clean a reload instr - | RELOAD{} <- instr + | RELOAD{} <- li = do (assoc', mli) <- cleanReload blockId assoc li case mli of Nothing -> cleanForward blockId assoc' acc instrs Just li' -> cleanForward blockId assoc' (li' : acc) instrs -- remember the association over a jump - | targets <- jumpDests instr [] + | Instr instr _ <- li + , targets <- jumpDestsOfInstr instr , not $ null targets = do mapM_ (accJumpValid assoc) targets cleanForward blockId assoc (li : acc) instrs -- writing to a reg changes its value. - | RU _ written <- regUsage instr + | Instr instr _ <- li + , RU _ written <- regUsageOfInstr instr = let assoc' = foldr delAssoc assoc (map SReg $ nub written) in cleanForward blockId assoc' (li : acc) instrs +-- bogus, to stop pattern match warning +cleanForward _ _ _ _ + = panic "RegAlloc.Graph.SpillClean.cleanForward: no match" + -- | Try and rewrite a reload instruction to something more pleasing -- -cleanReload :: BlockId -> Assoc Store -> LiveInstr -> CleanM (Assoc Store, Maybe LiveInstr) -cleanReload blockId assoc li@(Instr (RELOAD slot reg) _) +cleanReload + :: Instruction instr + => BlockId + -> Assoc Store + -> LiveInstr instr + -> CleanM (Assoc Store, Maybe (LiveInstr instr)) + +cleanReload blockId assoc li@(RELOAD slot reg) -- if the reg we're reloading already has the same value as the slot -- then we can erase the instruction outright @@ -264,10 +291,10 @@ cleanReload _ _ _ -- we should really be updating the noReloads set as we cross jumps also. -- cleanBackward - :: UniqSet Int -- ^ slots that have been spilled, but not reloaded from - -> [LiveInstr] -- ^ acc - -> [LiveInstr] -- ^ instrs to clean (in forwards order) - -> CleanM [LiveInstr] -- ^ cleaned instrs (in backwards order) + :: UniqSet Int -- ^ slots that have been spilled, but not reloaded from + -> [LiveInstr instr] -- ^ acc + -> [LiveInstr instr] -- ^ instrs to clean (in forwards order) + -> CleanM [LiveInstr instr] -- ^ cleaned instrs (in backwards order) cleanBackward noReloads acc lis @@ -277,15 +304,15 @@ cleanBackward noReloads acc lis cleanBackward' _ _ acc [] = return acc -cleanBackward' reloadedBy noReloads acc (li@(Instr instr _) : instrs) +cleanBackward' reloadedBy noReloads acc (li : instrs) -- if nothing ever reloads from this slot then we don't need the spill - | SPILL _ slot <- instr + | SPILL _ slot <- li , Nothing <- lookupUFM reloadedBy (SSlot slot) = do modify $ \s -> s { sCleanedSpillsAcc = sCleanedSpillsAcc s + 1 } cleanBackward noReloads acc instrs - | SPILL _ slot <- instr + | SPILL _ slot <- li = if elementOfUniqSet slot noReloads -- we can erase this spill because the slot won't be read until after the next one @@ -299,7 +326,7 @@ cleanBackward' reloadedBy noReloads acc (li@(Instr instr _) : instrs) cleanBackward noReloads' (li : acc) instrs -- if we reload from a slot then it's no longer unused - | RELOAD slot _ <- instr + | RELOAD slot _ <- li , noReloads' <- delOneFromUniqSet noReloads slot = cleanBackward noReloads' (li : acc) instrs