X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fcmm%2FCmmCPS.hs;h=4394fb595e8e8f8faed34c99e7dec3eba1e88170;hb=af452780391355f7008fe97e556ced25a3dd2d21;hp=60493fc3643eb5a97fda51a3e6eb172721591254;hpb=c150d2f6eed70f548d9094378eff602a94ca1fb8;p=ghc-hetmet.git diff --git a/compiler/cmm/CmmCPS.hs b/compiler/cmm/CmmCPS.hs index 60493fc..4394fb5 100644 --- a/compiler/cmm/CmmCPS.hs +++ b/compiler/cmm/CmmCPS.hs @@ -1,4 +1,8 @@ -module CmmCPS (cmmCPS) where +module CmmCPS ( + -- | Converts C-- with full proceedures and parameters + -- to a CPS transformed C-- with the stack made manifest. + cmmCPS +) where #include "HsVersions.h" @@ -6,15 +10,24 @@ import Cmm import CmmLint import PprCmm -import Dataflow (fixedpoint) import CmmLive - +import CmmBrokenBlock +import CmmProcPoint +import CmmCallConv +import CmmInfo +import CmmUtils + +import CgProf (curCCS, curCCSAddr) +import CgUtils (cmmOffsetW) +import Bitmap +import ClosureInfo import MachOp import ForeignCall import CLabel import SMRep import Constants +import StaticFlags import DynFlags import ErrUtils import Maybes @@ -28,6 +41,184 @@ import Monad import IO import Data.List +import MachRegs (callerSaveVolatileRegs) + -- HACK: this is part of the NCG so we shouldn't use this, but we need + -- it for now to eliminate the need for saved regs to be in CmmCall. + -- The long term solution is to factor callerSaveVolatileRegs + -- from nativeGen into CPS + +----------------------------------------------------------------------------- +-- |Top level driver for the CPS pass +----------------------------------------------------------------------------- +cmmCPS :: DynFlags -- ^ Dynamic flags: -dcmm-lint -ddump-cps-cmm + -> [GenCmm CmmStatic CmmInfo CmmStmt] -- ^ Input C-- with Proceedures + -> IO [GenCmm CmmStatic [CmmStatic] CmmStmt] -- ^ Output CPS transformed C-- +cmmCPS dflags abstractC = do + when (dopt Opt_DoCmmLinting dflags) $ + do showPass dflags "CmmLint" + case firstJust $ map cmmLint abstractC of + Just err -> do printDump err + ghcExit dflags 1 + Nothing -> return () + showPass dflags "CPS" + + -- TODO: more lint checking + -- check for use of branches to non-existant blocks + -- check for use of Sp, SpLim, R1, R2, etc. + + uniqSupply <- mkSplitUniqSupply 'p' + let supplies = listSplitUniqSupply uniqSupply + let doCpsProc s (Cmm c) = + Cmm $ concat $ zipWith cpsProc (listSplitUniqSupply s) c + let continuationC = zipWith doCpsProc supplies abstractC + + dumpIfSet_dyn dflags Opt_D_dump_cps_cmm "CPS Cmm" (pprCmms continuationC) + + -- TODO: add option to dump Cmm to file + + return continuationC + +stg_gc_gen = mkRtsApFastLabel SLIT("gen_cg_TODO") --panic "Need the label for gc" +make_gc_block block_id fun_label formals safety = BasicBlock block_id stmts + where + stmts = [CmmCall stg_gc_gen_target [] [] safety, + CmmJump fun_expr actuals] + stg_gc_gen_target = + CmmForeignCall (CmmLit (CmmLabel stg_gc_gen)) CmmCallConv + actuals = map (\x -> (CmmReg (CmmLocal x), NoHint)) formals + fun_expr = CmmLit (CmmLabel fun_label) + +make_gc_check stack_use gc_block = + [CmmCondBranch + (CmmMachOp (MO_U_Lt $ cmmRegRep spReg) + [CmmReg stack_use, CmmReg spLimReg]) + gc_block] + +force_gc_block old_info stack_use block_id fun_label formals = + case old_info of + CmmNonInfo (Just existing) -> (old_info, [], make_gc_check stack_use existing) + CmmInfo _ (Just existing) _ _ -> (old_info, [], make_gc_check stack_use existing) + CmmNonInfo Nothing + -> (CmmNonInfo (Just block_id), + [make_gc_block block_id fun_label formals (CmmSafe NoC_SRT)], + make_gc_check stack_use block_id) + CmmInfo prof Nothing type_tag type_info + -> (CmmInfo prof (Just block_id) type_tag type_info, + [make_gc_block block_id fun_label formals (CmmSafe srt)], + make_gc_check stack_use block_id) + where + srt = case type_info of + ConstrInfo _ _ _ -> NoC_SRT + FunInfo _ srt' _ _ _ _ -> srt' + ThunkInfo _ srt' -> srt' + ThunkSelectorInfo _ srt' -> srt' + ContInfo _ srt' -> srt' + +----------------------------------------------------------------------------- +-- |CPS a single CmmTop (proceedure) +-- Only 'CmmProc' are transformed 'CmmData' will be left alone. +----------------------------------------------------------------------------- + +cpsProc :: UniqSupply + -> GenCmmTop CmmStatic CmmInfo CmmStmt -- ^Input proceedure + -> [GenCmmTop CmmStatic [CmmStatic] CmmStmt] -- ^Output proceedure and continuations +cpsProc uniqSupply (CmmData sec dat) = [CmmData sec dat] +cpsProc uniqSupply (CmmProc info ident params blocks) = info_procs + where + (uniqSupply1, uniqSupply2) = splitUniqSupply uniqSupply + uniques :: [[Unique]] + uniques = map uniqsFromSupply $ listSplitUniqSupply uniqSupply1 + (gc_unique:stack_use_unique:info_uniques):adaptor_uniques:block_uniques = uniques + proc_uniques = map (map uniqsFromSupply . listSplitUniqSupply) $ listSplitUniqSupply uniqSupply2 + + stack_use = CmmLocal (LocalReg stack_use_unique (cmmRegRep spReg) KindPtr) + + -- TODO: doc + forced_gc :: (CmmInfo, [CmmBasicBlock], [CmmStmt]) + forced_gc = force_gc_block info stack_use (BlockId gc_unique) ident params + (forced_info, gc_blocks, check_stmts) = forced_gc + + forced_blocks = + case blocks of + (BasicBlock id stmts) : bs -> + (BasicBlock id (check_stmts ++ stmts)) : (bs ++ gc_blocks) + [] -> [] -- If there is no code then we don't need a stack check + + forced_gc_id = case forced_info of + CmmNonInfo (Just x) -> x + CmmInfo _ (Just x) _ _ -> x + + -- Break the block at each function call. + -- The part after the function call will have to become a continuation. + broken_blocks :: ([(BlockId, ContFormat)], [BrokenBlock]) + broken_blocks = + (\x -> (concatMap fst x, concatMap snd x)) $ + zipWith3 (breakBlock [forced_gc_id]) + block_uniques + forced_blocks + (FunctionEntry forced_info ident params : + repeat ControlEntry) + + f' = selectContinuations (fst broken_blocks) + broken_blocks' = map (makeContinuationEntries f') $ + concat $ + zipWith (adaptBlockToFormat f') + adaptor_uniques + (snd broken_blocks) + + -- Calculate live variables for each broken block. + -- + -- Nothing can be live on entry to the first block + -- so we could take the tail, but for now we wont + -- to help future proof the code. + live :: BlockEntryLiveness + live = cmmLiveness $ map cmmBlockFromBrokenBlock broken_blocks' + + -- Calculate which blocks must be made into full fledged procedures. + proc_points :: UniqSet BlockId + proc_points = calculateProcPoints broken_blocks' + + -- Construct a map so we can lookup a broken block by its 'BlockId'. + block_env :: BlockEnv BrokenBlock + block_env = blocksToBlockEnv broken_blocks' + + -- Group the blocks into continuations based on the set of proc-points. + continuations :: [Continuation (Either C_SRT CmmInfo)] + continuations = zipWith + (gatherBlocksIntoContinuation live proc_points block_env) + (uniqSetToList proc_points) + (Just forced_gc_id : repeat Nothing) {-dead-} + + -- Select the stack format on entry to each continuation. + -- Return the max stack offset and an association list + -- + -- This is an association list instead of a UniqFM because + -- CLabel's don't have a 'Uniqueable' instance. + formats :: [(CLabel, -- key + (CmmFormals, -- arguments + Maybe CLabel, -- label in top slot + [Maybe LocalReg]))] -- slots + formats = selectContinuationFormat live continuations + + -- Do a little meta-processing on the stack formats such as + -- getting the individual frame sizes and the maximum frame size + formats' :: (WordOff, [(CLabel, ContinuationFormat)]) + formats' = processFormats formats continuations + + -- Update the info table data on the continuations with + -- the selected stack formats. + continuations' :: [Continuation CmmInfo] + continuations' = map (applyContinuationFormat (snd formats')) continuations + + -- Do the actual CPS transform. + cps_procs :: [CmmTop] + cps_procs = zipWith (continuationToProc formats' stack_use) proc_uniques continuations' + + -- Convert the info tables from CmmInfo to [CmmStatic] + -- We might want to put this in another pass eventually + info_procs :: [RawCmmTop] + info_procs = concat (zipWith mkInfoTable info_uniques cps_procs) + -------------------------------------------------------------------------------- -- The format for the call to a continuation @@ -45,33 +236,15 @@ import Data.List -- and heap memory (not sure if that's usefull at all though, but it may -- be worth exploring the design space). -data BrokenBlock - = BrokenBlock { - brokenBlockId :: BlockId, -- Like a CmmBasicBlock - brokenBlockEntry :: BlockEntryInfo, - -- How this block can be entered - - brokenBlockStmts :: [CmmStmt], - -- Like a CmmBasicBlock - -- (but without the last statement) - - brokenBlockTargets :: [BlockId], - -- Blocks that this block could - -- branch to one either by conditional - -- branches or via the last statement - - brokenBlockExit :: FinalStmt - -- How the block can be left - } - -continuationLabel (Continuation _ _ l _ _) = l -data Continuation = +continuationLabel (Continuation _ l _ _ _) = l +data Continuation info = Continuation - Bool -- True => Function entry, False => Continuation/return point - [CmmStatic] -- Info table, may be empty + info -- Left <=> Continuation created by the CPS + -- Right <=> Function or Proc point CLabel -- Used to generate both info & entry labels CmmFormals -- Argument locals live on entry (C-- procedure params) - [BrokenBlock] -- Code, may be empty. The first block is + Bool -- ^ True <=> GC block so ignore stack size + [BrokenBlock] -- Code, may be empty. The first block is -- the entry point. The order is otherwise initially -- unimportant, but at some point the code gen will -- fix the order. @@ -80,552 +253,613 @@ data Continuation = -- to a label. To jump to the first block in a Proc, -- use the appropriate CLabel. -data BlockEntryInfo - = FunctionEntry -- Beginning of a function - CLabel -- The function name - CmmFormals -- Aguments to function - - | ContinuationEntry -- Return point of a call - CmmFormals -- return values (argument to continuation) - -- TODO: - -- | ProcPointEntry -- no return values, but some live might end up as params or possibly in the frame - - | ControlEntry -- A label in the input - --- Final statement in a BlokenBlock --- Constructors and arguments match those in Cmm, --- but are restricted to branches, returns, jumps, calls and switches -data FinalStmt - = FinalBranch - BlockId -- next block (must be a ControlEntry) - - | FinalReturn - CmmActuals -- return values - - | FinalJump - CmmExpr -- the function to call - CmmActuals -- arguments to call - - | FinalCall - BlockId -- next block after call (must be a ContinuationEntry) - CmmCallTarget -- the function to call - CmmFormals -- results from call (redundant with ContinuationEntry) - CmmActuals -- arguments to call - (Maybe [GlobalReg]) -- registers that must be saved (TODO) - - | FinalSwitch - CmmExpr [Maybe BlockId] -- Table branch - - -- TODO: | ProcPointExit (needed?) - -data StackFormat - = StackFormat - BlockId {- block that is the start of the continuation. may or may not be the current block -} - WordOff {- total frame size -} - [(CmmReg, WordOff)] {- local reg offsets from stack top -} +data ContinuationFormat + = ContinuationFormat { + continuation_formals :: CmmFormals, + continuation_label :: Maybe CLabel, -- The label occupying the top slot + continuation_frame_size :: WordOff, -- Total frame size in words (not including arguments) + continuation_stack :: [Maybe LocalReg] -- local reg offsets from stack top + } -- A block can be a continuation of a call -- A block can be a continuation of another block (w/ or w/o joins) -- A block can be an entry to a function -blocksToBlockEnv :: [BrokenBlock] -> BlockEnv BrokenBlock -blocksToBlockEnv blocks = listToUFM $ map (\b -> (brokenBlockId b, b)) blocks - ----------------------------------------------------------------------------- -calculateOwnership :: UniqSet BlockId -> [BrokenBlock] -> BlockEnv (UniqSet BlockId) -calculateOwnership proc_points blocks = - fixedpoint dependants update (map brokenBlockId blocks) emptyUFM - where - blocks_ufm :: BlockEnv BrokenBlock - blocks_ufm = blocksToBlockEnv blocks - - dependants :: BlockId -> [BlockId] - dependants ident = - brokenBlockTargets $ lookupWithDefaultUFM - blocks_ufm unknown_block ident - - update :: BlockId -> Maybe BlockId - -> BlockEnv (UniqSet BlockId) -> Maybe (BlockEnv (UniqSet BlockId)) - update ident cause owners = - case (cause, ident `elementOfUniqSet` proc_points) of - (Nothing, True) -> Just $ addToUFM owners ident (unitUniqSet ident) - (Nothing, False) -> Nothing - (Just cause', True) -> Nothing - (Just cause', False) -> - if (sizeUniqSet old) == (sizeUniqSet new) - then Nothing - else Just $ addToUFM owners ident new - where - old = lookupWithDefaultUFM owners emptyUniqSet ident - new = old `unionUniqSets` lookupWithDefaultUFM owners emptyUniqSet cause' - - unknown_block = panic "unknown BlockId in selectStackFormat" - -calculateProcPoints :: [BrokenBlock] -> UniqSet BlockId -calculateProcPoints blocks = calculateProcPoints' init_proc_points blocks - where - init_proc_points = mkUniqSet $ - map brokenBlockId $ - filter always_proc_point blocks - always_proc_point BrokenBlock { - brokenBlockEntry = FunctionEntry _ _ } = True - always_proc_point BrokenBlock { - brokenBlockEntry = ContinuationEntry _ } = True - always_proc_point _ = False - -calculateProcPoints' :: UniqSet BlockId -> [BrokenBlock] -> UniqSet BlockId -calculateProcPoints' old_proc_points blocks = - if sizeUniqSet old_proc_points == sizeUniqSet new_proc_points - then old_proc_points - else calculateProcPoints' new_proc_points blocks - where - owners = calculateOwnership old_proc_points blocks - new_proc_points = unionManyUniqSets (old_proc_points:(map (calculateProcPoints'' owners) blocks)) - -calculateProcPoints'' :: BlockEnv (UniqSet BlockId) -> BrokenBlock -> UniqSet BlockId -calculateProcPoints'' owners block = - unionManyUniqSets (map (f parent_id) child_ids) - where - parent_id = brokenBlockId block - child_ids = brokenBlockTargets block - f parent_id child_id = - if needs_proc_point - then unitUniqSet child_id - else emptyUniqSet - where - parent_owners = lookupWithDefaultUFM owners emptyUniqSet parent_id - child_owners = lookupWithDefaultUFM owners emptyUniqSet child_id - needs_proc_point = not $ isEmptyUniqSet $ child_owners `minusUniqSet` parent_owners - --needs_proc_point = sizeUniqSet (parent_owners `unionUniqSets` child_owners) /= sizeUniqSet parent_owners - -cmmCondBranchTargets (CmmCondBranch _ target) = [target] -cmmCondBranchTargets _ = [] - -finalBranchOrSwitchTargets (FinalBranch target) = [target] -finalBranchOrSwitchTargets (FinalSwitch _ targets) = mapCatMaybes id targets -finalBranchOrSwitchTargets _ = [] collectNonProcPointTargets :: UniqSet BlockId -> BlockEnv BrokenBlock - -> UniqSet BlockId -> BlockId -> UniqSet BlockId -collectNonProcPointTargets proc_points blocks current_targets block = + -> UniqSet BlockId -> [BlockId] -> UniqSet BlockId +collectNonProcPointTargets proc_points blocks current_targets new_blocks = if sizeUniqSet current_targets == sizeUniqSet new_targets then current_targets - else foldl (collectNonProcPointTargets proc_points blocks) new_targets targets + else foldl + (collectNonProcPointTargets proc_points blocks) + new_targets + (map (:[]) targets) where - block' = lookupWithDefaultUFM blocks (panic "TODO") block - targets = -- We can't use the brokenBlockTargets b/c we don't want to follow the final goto after a call -- brokenBlockTargets block' - --finalBranchOrSwitchTargets (brokenBlockExit block') ++ concatMap cmmCondBranchTargets (brokenBlockStmts block') - uniqSetToList $ (mkUniqSet $ brokenBlockTargets block') `minusUniqSet` proc_points + blocks' = map (lookupWithDefaultUFM blocks (panic "TODO")) new_blocks + targets = + -- Note the subtlety that since the extra branch after a call + -- will always be to a block that is a proc-point, + -- this subtraction will always remove that case + uniqSetToList $ (unionManyUniqSets $ map (mkUniqSet . brokenBlockTargets) blocks') + `minusUniqSet` proc_points -- TODO: remove redundant uniqSetToList new_targets = current_targets `unionUniqSets` (mkUniqSet targets) -buildContinuation :: - UniqSet BlockId -> BlockEnv BrokenBlock - -> BlockId -> Continuation -buildContinuation proc_points blocks start = - Continuation is_entry info_table clabel params body +-- TODO: insert proc point code here +-- * Branches and switches to proc points may cause new blocks to be created +-- (or proc points could leave behind phantom blocks that just jump to them) +-- * Proc points might get some live variables passed as arguments + +gatherBlocksIntoContinuation :: + BlockEntryLiveness -> UniqSet BlockId -> BlockEnv BrokenBlock + -> BlockId -> Maybe BlockId -> Continuation (Either C_SRT CmmInfo) +gatherBlocksIntoContinuation live proc_points blocks start gc = + Continuation info_table clabel params is_gc_cont body where - children = (collectNonProcPointTargets proc_points blocks (unitUniqSet start) start) `delOneFromUniqSet` start + --start_and_gc = [start] -- : maybeToList gc + --children = (collectNonProcPointTargets proc_points blocks (mkUniqSet start_and_gc) start_and_gc) `minusUniqSet` (mkUniqSet start_and_gc) + children = (collectNonProcPointTargets proc_points blocks (unitUniqSet start) [start]) `minusUniqSet` (unitUniqSet start) start_block = lookupWithDefaultUFM blocks (panic "TODO") start + unknown_block = panic "unknown block in gatherBlocksIntoContinuation" + --gc_block = map (lookupWithDefaultUFM blocks (panic "TODO)")) + -- (maybeToList gc) children_blocks = map (lookupWithDefaultUFM blocks (panic "TODO")) (uniqSetToList children) - body = start_block : children_blocks - info_table = [] -- TODO + body = start_block : {-gc_block ++ -} children_blocks + + -- We can't properly annotate the continuation's stack parameters + -- at this point because this is before stack selection + -- but we want to keep the C_SRT around so we use 'Either'. + info_table = case start_block_entry of + FunctionEntry info _ _ -> Right info + ContinuationEntry _ srt _ -> Left srt + ControlEntry -> Right (CmmNonInfo Nothing) + + is_gc_cont = case start_block_entry of + FunctionEntry _ _ _ -> False + ContinuationEntry _ _ gc_cont -> gc_cont + ControlEntry -> False + start_block_entry = brokenBlockEntry start_block - is_entry = case start_block_entry of - FunctionEntry _ _ -> True - _ -> False clabel = case start_block_entry of - FunctionEntry label _ -> label + FunctionEntry _ label _ -> label _ -> mkReturnPtLabel $ getUnique start params = case start_block_entry of - FunctionEntry _ args -> args - ContinuationEntry args -> args - ControlEntry -> [] -- TODO: it's a proc-point, we could pass lives in parameter registers + FunctionEntry _ _ args -> args + ContinuationEntry args _ _ -> args + ControlEntry -> + uniqSetToList $ + lookupWithDefaultUFM live unknown_block start + -- it's a proc-point, pass lives in parameter registers -------------------------------------------------------------------------------- -- For now just select the continuation orders in the order they are in the set with no gaps -selectStackFormat :: BlockEnv CmmLive -> [BrokenBlock] -> BlockEnv StackFormat -selectStackFormat live blocks = - fixedpoint dependants update (map brokenBlockId blocks) emptyUFM - where - blocks_ufm :: BlockEnv BrokenBlock - blocks_ufm = listToUFM $ map (\b -> (brokenBlockId b, b)) blocks - - dependants :: BlockId -> [BlockId] - dependants ident = - brokenBlockTargets $ lookupWithDefaultUFM - blocks_ufm unknown_block ident - - update :: BlockId -> Maybe BlockId - -> BlockEnv StackFormat -> Maybe (BlockEnv StackFormat) - update ident cause formats = - if ident `elemUFM` formats - then Nothing -- Blocks only need to be updated once - else case (cause, - brokenBlockEntry $ lookupWithDefaultUFM blocks_ufm - unknown_block ident) of - -- Propagate only to blocks entered by branches - -- (not function entry blocks or continuation entry blocks) - (Just cause_name, ControlEntry) -> - Just $ addToUFM formats ident cause_format - where cause_format = lookupWithDefaultUFM - formats unknown_block - cause_name - -- Do initial calculates for function blocks - (Nothing, FunctionEntry _ _) -> - Just $ - addToUFM formats ident $ - StackFormat ident 0 [] - -- Do initial calculates for continuation blocks - (Nothing, ContinuationEntry _) -> - Just $ - addToUFM formats ident $ - live_to_format ident $ - lookupWithDefaultUFM live unknown_block ident - _ -> Nothing - - unknown_block = panic "unknown BlockId in selectStackFormat" - - live_to_format :: BlockId -> CmmLive -> StackFormat - live_to_format label live = - foldl extend_format - (StackFormat label retAddrSizeW []) - (uniqSetToList live) - - extend_format :: StackFormat -> LocalReg -> StackFormat - extend_format (StackFormat block size offsets) reg = - StackFormat block (slot_size reg + size) ((CmmLocal reg, size) : offsets) - -selectStackFormat2 :: BlockEnv CmmLive -> [Continuation] -> [(CLabel, StackFormat)] -selectStackFormat2 live continuations = - map (\c -> (continuationLabel c, selectStackFormat' c)) continuations +selectContinuationFormat :: BlockEnv CmmLive + -> [Continuation (Either C_SRT CmmInfo)] + -> [(CLabel, (CmmFormals, Maybe CLabel, [Maybe LocalReg]))] +selectContinuationFormat live continuations = + map (\c -> (continuationLabel c, selectContinuationFormat' c)) continuations where - selectStackFormat' (Continuation True info_table label formals blocks) = - let ident = brokenBlockId $ head blocks -- TODO: CLabel isn't a uniquable, but we need a better way than this - in StackFormat ident 0 [] - selectStackFormat' (Continuation False info_table label formals blocks) = + -- User written continuations + selectContinuationFormat' (Continuation + (Right (CmmInfo _ _ _ (ContInfo format srt))) + label formals _ _) = + (formals, Just label, format) + -- Either user written non-continuation code + -- or CPS generated proc-points + selectContinuationFormat' (Continuation (Right _) _ formals _ _) = + (formals, Nothing, []) + -- CPS generated continuations + selectContinuationFormat' (Continuation (Left srt) label formals _ blocks) = + -- TODO: assumes the first block is the entry block let ident = brokenBlockId $ head blocks -- TODO: CLabel isn't a uniquable, but we need a better way than this - in live_to_format ident $ lookupWithDefaultUFM live unknown_block ident + in (formals, + Just label, + map Just $ uniqSetToList $ + lookupWithDefaultUFM live unknown_block ident) - live_to_format :: BlockId -> CmmLive -> StackFormat - live_to_format label live = - foldl extend_format - (StackFormat label retAddrSizeW []) - (uniqSetToList live) + unknown_block = panic "unknown BlockId in selectContinuationFormat" - extend_format :: StackFormat -> LocalReg -> StackFormat - extend_format (StackFormat block size offsets) reg = - StackFormat block (slot_size reg + size) ((CmmLocal reg, size) : offsets) - - unknown_block = panic "unknown BlockId in selectStackFormat" - -slot_size reg = ((machRepByteWidth (localRegRep reg) - 1) `div` wORD_SIZE) + 1 - -constructContinuation :: [(CLabel, StackFormat)] -> Continuation -> CmmTop -constructContinuation formats (Continuation is_entry info label formals blocks) = - CmmProc info label formals (map (constructContinuation2' label formats) blocks) +processFormats :: [(CLabel, (CmmFormals, Maybe CLabel, [Maybe LocalReg]))] + -> [Continuation (Either C_SRT CmmInfo)] + -> (WordOff, [(CLabel, ContinuationFormat)]) +processFormats formats continuations = (max_size, formats') + where + max_size = maximum $ + 0 : map (continuationMaxStack formats') continuations + formats' = map make_format formats + make_format (label, (formals, top, stack)) = + (label, + ContinuationFormat { + continuation_formals = formals, + continuation_label = top, + continuation_frame_size = stack_size stack + + if isJust top + then label_size + else 0, + continuation_stack = stack }) + + -- TODO: get rid of "+ 1" etc. + label_size = 1 :: WordOff + + stack_size [] = 0 + stack_size (Nothing:formats) = 1 + stack_size formats -- one dead word + stack_size (Just reg:formats) = width + stack_size formats + where + width = machRepByteWidth (localRegRep reg) `quot` wORD_SIZE + -- TODO: it would be better if we had a machRepWordWidth + +continuationMaxStack :: [(CLabel, ContinuationFormat)] + -> Continuation a + -> WordOff +continuationMaxStack _ (Continuation _ _ _ True _) = 0 +continuationMaxStack formats (Continuation _ label _ False blocks) = + max_arg_size + continuation_frame_size stack_format + where + stack_format = maybe unknown_format id $ lookup label formats + unknown_format = panic "Unknown format in continuationMaxStack" + + max_arg_size = maximum $ 0 : map block_max_arg_size blocks + + block_max_arg_size block = + maximum (final_arg_size (brokenBlockExit block) : + map stmt_arg_size (brokenBlockStmts block)) + + final_arg_size (FinalReturn args) = + argumentsSize (cmmExprRep . fst) args + final_arg_size (FinalJump _ args) = + argumentsSize (cmmExprRep . fst) args + final_arg_size (FinalCall next _ _ args _ True) = 0 + final_arg_size (FinalCall next _ _ args _ False) = + -- We have to account for the stack used when we build a frame + -- for the *next* continuation from *this* continuation + argumentsSize (cmmExprRep . fst) args + + continuation_frame_size next_format + where + next_format = maybe unknown_format id $ lookup next' formats + next' = mkReturnPtLabel $ getUnique next + + final_arg_size _ = 0 + + stmt_arg_size (CmmJump _ args) = + argumentsSize (cmmExprRep . fst) args + stmt_arg_size (CmmCall _ _ _ (CmmSafe _)) = + panic "Safe call in processFormats" + stmt_arg_size (CmmReturn _) = + panic "CmmReturn in processFormats" + stmt_arg_size _ = 0 -{- - BasicBlock ident (prefix++stmts++postfix) +----------------------------------------------------------------------------- +applyContinuationFormat :: [(CLabel, ContinuationFormat)] + -> Continuation (Either C_SRT CmmInfo) + -> Continuation CmmInfo + +-- User written continuations +applyContinuationFormat formats (Continuation + (Right (CmmInfo prof gc tag (ContInfo _ srt))) + label formals is_gc blocks) = + Continuation (CmmInfo prof gc tag (ContInfo format srt)) + label formals is_gc blocks where - - curr_format = lookupWithDefaultUFM formats unknown_block ident - unknown_block = panic "unknown BlockId in constructContinuation" - prefix = case entry of - ControlEntry -> [] - FunctionEntry _ -> [] - ContinuationEntry formals -> - unpack_continuation curr_format - postfix = case exit of - FinalBranch next -> [CmmBranch next] - FinalSwitch expr targets -> [CmmSwitch expr targets] - FinalReturn arguments -> - exit_function curr_format - (CmmLoad (CmmReg spReg) wordRep) - arguments - FinalJump target arguments -> - exit_function curr_format target arguments - -- TODO: do something about global saves - FinalCall next (CmmForeignCall target CmmCallConv) - results arguments saves -> - pack_continuation curr_format cont_format ++ - [CmmJump target arguments] - where - cont_format = lookupWithDefaultUFM formats - unknown_block next - FinalCall next _ results arguments saves -> panic "unimplemented CmmCall" --} - -constructContinuation2' :: CLabel -> [(CLabel, StackFormat)] -> BrokenBlock - -> CmmBasicBlock -constructContinuation2' curr_ident formats (BrokenBlock ident entry stmts _ exit) = - BasicBlock ident (prefix++stmts++postfix) + format = continuation_stack $ maybe unknown_block id $ lookup label formats + unknown_block = panic "unknown BlockId in applyContinuationFormat" + +-- Either user written non-continuation code or CPS generated proc-point +applyContinuationFormat formats (Continuation + (Right info) label formals is_gc blocks) = + Continuation info label formals is_gc blocks + +-- CPS generated continuations +applyContinuationFormat formats (Continuation + (Left srt) label formals is_gc blocks) = + Continuation (CmmInfo prof gc tag (ContInfo (continuation_stack $ format) srt)) + label formals is_gc blocks where - curr_format = maybe unknown_block id $ lookup curr_ident formats - unknown_block = panic "unknown BlockId in constructContinuation" - prefix = case entry of - ControlEntry -> [] - FunctionEntry _ _ -> [] - ContinuationEntry formals -> - unpack_continuation curr_format - postfix = case exit of - FinalBranch next -> [CmmBranch next] - FinalSwitch expr targets -> [CmmSwitch expr targets] - FinalReturn arguments -> - exit_function curr_format - (CmmLoad (CmmReg spReg) wordRep) - arguments - FinalJump target arguments -> - exit_function curr_format target arguments - -- TODO: do something about global saves - FinalCall next (CmmForeignCall target CmmCallConv) - results arguments saves -> - pack_continuation curr_format cont_format ++ - [CmmJump target arguments] + gc = Nothing -- Generated continuations never need a stack check + -- TODO prof: this is the same as the current implementation + -- but I think it could be improved + prof = ProfilingInfo zeroCLit zeroCLit + tag = rET_SMALL -- cmmToRawCmm may convert it to rET_BIG + format = maybe unknown_block id $ lookup label formats + unknown_block = panic "unknown BlockId in applyContinuationFormat" + +----------------------------------------------------------------------------- +continuationToProc :: (WordOff, [(CLabel, ContinuationFormat)]) + -> CmmReg + -> [[Unique]] + -> Continuation CmmInfo + -> CmmTop +continuationToProc (max_stack, formats) stack_use uniques + (Continuation info label formals _ blocks) = + CmmProc info label formals (concat $ zipWith3 continuationToProc' uniques blocks (True : repeat False)) + where + curr_format = maybe unknown_block id $ lookup label formats + unknown_block = panic "unknown BlockId in continuationToProc" + curr_stack = continuation_frame_size curr_format + arg_stack = argumentsSize localRegRep formals + + param_stmts :: [CmmStmt] + param_stmts = function_entry curr_format + + gc_stmts :: [CmmStmt] + gc_stmts = + case info of + CmmInfo _ (Just gc_block) _ _ -> + gc_stack_check' stack_use arg_stack (max_stack - curr_stack) + CmmInfo _ Nothing _ _ -> + panic "continuationToProc: missing GC block" + CmmNonInfo (Just gc_block) -> + gc_stack_check' stack_use arg_stack (max_stack - curr_stack) + CmmNonInfo Nothing -> + panic "continuationToProc: missing non-info GC block" + +-- At present neither the Cmm parser nor the code generator +-- produce code that will allow the target of a CmmCondBranch +-- or a CmmSwitch to become a continuation or a proc-point. +-- If future revisions, might allow these to happen +-- then special care will have to be take to allow for that case. + continuationToProc' :: [Unique] + -> BrokenBlock + -> Bool + -> [CmmBasicBlock] + continuationToProc' uniques (BrokenBlock ident entry stmts _ exit) is_entry = + prefix_blocks ++ [main_block] + where + prefix_blocks = + case gc_prefix ++ param_prefix of + [] -> [] + entry_stmts -> [BasicBlock prefix_id + (entry_stmts ++ [CmmBranch ident])] + + prefix_unique : call_uniques = uniques + toCLabel = mkReturnPtLabel . getUnique + + block_for_branch unique next + | (Just cont_format) <- lookup (toCLabel next) formats + = let + new_next = BlockId unique + cont_stack = continuation_frame_size cont_format + arguments = map formal_to_actual (continuation_formals cont_format) + in (new_next, + [BasicBlock new_next $ + pack_continuation False curr_format cont_format ++ + tail_call (curr_stack - cont_stack) + (CmmLit $ CmmLabel $ toCLabel next) + arguments]) + | otherwise + = (next, []) + + block_for_branch' :: Unique -> Maybe BlockId -> (Maybe BlockId, [CmmBasicBlock]) + block_for_branch' _ Nothing = (Nothing, []) + block_for_branch' unique (Just next) = (Just new_next, new_blocks) + where (new_next, new_blocks) = block_for_branch unique next + + main_block = BasicBlock ident (stmts ++ postfix_stmts) + prefix_id = BlockId prefix_unique + gc_prefix = case entry of + FunctionEntry _ _ _ -> gc_stmts + ControlEntry -> [] + ContinuationEntry _ _ _ -> [] + param_prefix = if is_entry + then param_stmts + else [] + postfix_stmts = case exit of + FinalBranch next -> + if (mkReturnPtLabel $ getUnique next) == label + then [CmmBranch next] + else case lookup (mkReturnPtLabel $ getUnique next) formats of + Nothing -> [CmmBranch next] + Just cont_format -> + pack_continuation False curr_format cont_format ++ + tail_call (curr_stack - cont_stack) + (CmmLit $ CmmLabel $ mkReturnPtLabel $ getUnique next) + arguments + where + cont_stack = continuation_frame_size cont_format + arguments = map formal_to_actual (continuation_formals cont_format) + FinalSwitch expr targets -> [CmmSwitch expr targets] + FinalReturn arguments -> + tail_call curr_stack + (CmmLoad (CmmReg spReg) wordRep) + arguments + FinalJump target arguments -> + tail_call curr_stack target arguments + + -- A regular Cmm function call + FinalCall next (CmmForeignCall target CmmCallConv) + results arguments _ _ -> + pack_continuation True curr_format cont_format ++ + tail_call (curr_stack - cont_stack) + target arguments where cont_format = maybe unknown_block id $ lookup (mkReturnPtLabel $ getUnique next) formats - FinalCall next _ results arguments saves -> panic "unimplemented CmmCall" - -constructContinuation2 :: BlockEnv StackFormat -> BrokenBlock - -> CmmBasicBlock -constructContinuation2 formats (BrokenBlock ident entry stmts _ exit) = - BasicBlock ident (prefix++stmts++postfix) - where - curr_format = lookupWithDefaultUFM formats unknown_block ident - unknown_block = panic "unknown BlockId in constructContinuation" - prefix = case entry of - ControlEntry -> [] - FunctionEntry _ -> [] - ContinuationEntry formals -> - unpack_continuation curr_format - postfix = case exit of - FinalBranch next -> [CmmBranch next] - FinalSwitch expr targets -> [CmmSwitch expr targets] - FinalReturn arguments -> - exit_function curr_format - (CmmLoad (CmmReg spReg) wordRep) - arguments - FinalJump target arguments -> - exit_function curr_format target arguments - -- TODO: do something about global saves - FinalCall next (CmmForeignCall target CmmCallConv) - results arguments saves -> - pack_continuation curr_format cont_format ++ - [CmmJump target arguments] + cont_stack = continuation_frame_size cont_format + + -- A safe foreign call + FinalCall next (CmmForeignCall target conv) + results arguments _ _ -> + target_stmts ++ + foreignCall call_uniques' (CmmForeignCall new_target conv) + results arguments where - cont_format = lookupWithDefaultUFM formats - unknown_block next - FinalCall next _ results arguments saves -> panic "unimplemented CmmCall" + (call_uniques', target_stmts, new_target) = + maybeAssignTemp call_uniques target + + -- A safe prim call + FinalCall next (CmmPrim target) + results arguments _ _ -> + foreignCall call_uniques (CmmPrim target) + results arguments + +formal_to_actual reg = (CmmReg (CmmLocal reg), NoHint) + +foreignCall :: [Unique] -> CmmCallTarget -> CmmHintFormals -> CmmActuals -> [CmmStmt] +foreignCall uniques call results arguments = + arg_stmts ++ + saveThreadState ++ + caller_save ++ + [CmmCall (CmmForeignCall suspendThread CCallConv) + [ (id,PtrHint) ] + [ (CmmReg (CmmGlobal BaseReg), PtrHint) ] + CmmUnsafe, + CmmCall call results new_args CmmUnsafe, + CmmCall (CmmForeignCall resumeThread CCallConv) + [ (new_base, PtrHint) ] + [ (CmmReg (CmmLocal id), PtrHint) ] + CmmUnsafe, + -- Assign the result to BaseReg: we + -- might now have a different Capability! + CmmAssign (CmmGlobal BaseReg) (CmmReg (CmmLocal new_base))] ++ + caller_load ++ + loadThreadState tso_unique ++ + [CmmJump (CmmReg spReg) (map (formal_to_actual . fst) results)] + where + (_, arg_stmts, new_args) = + loadArgsIntoTemps argument_uniques arguments + (caller_save, caller_load) = + callerSaveVolatileRegs (Just [{-only system regs-}]) + new_base = LocalReg base_unique (cmmRegRep (CmmGlobal BaseReg)) KindNonPtr + id = LocalReg id_unique wordRep KindNonPtr + tso_unique : base_unique : id_unique : argument_uniques = uniques + +-- ----------------------------------------------------------------------------- +-- Save/restore the thread state in the TSO + +suspendThread = CmmLit (CmmLabel (mkRtsCodeLabel SLIT("suspendThread"))) +resumeThread = CmmLit (CmmLabel (mkRtsCodeLabel SLIT("resumeThread"))) + +-- This stuff can't be done in suspendThread/resumeThread, because it +-- refers to global registers which aren't available in the C world. + +saveThreadState = + -- CurrentTSO->sp = Sp; + [CmmStore (cmmOffset stgCurrentTSO tso_SP) stgSp, + closeNursery] ++ + -- and save the current cost centre stack in the TSO when profiling: + if opt_SccProfilingOn + then [CmmStore (cmmOffset stgCurrentTSO tso_CCCS) curCCS] + else [] + + -- CurrentNursery->free = Hp+1; +closeNursery = CmmStore nursery_bdescr_free (cmmOffsetW stgHp 1) + +loadThreadState tso_unique = + [ + -- tso = CurrentTSO; + CmmAssign (CmmLocal tso) stgCurrentTSO, + -- Sp = tso->sp; + CmmAssign sp (CmmLoad (cmmOffset (CmmReg (CmmLocal tso)) tso_SP) + wordRep), + -- SpLim = tso->stack + RESERVED_STACK_WORDS; + CmmAssign spLim (cmmOffsetW (cmmOffset (CmmReg (CmmLocal tso)) tso_STACK) + rESERVED_STACK_WORDS) + ] ++ + openNursery ++ + -- and load the current cost centre stack from the TSO when profiling: + if opt_SccProfilingOn + then [CmmStore curCCSAddr + (CmmLoad (cmmOffset (CmmReg (CmmLocal tso)) tso_CCCS) wordRep)] + else [] + where tso = LocalReg tso_unique wordRep KindNonPtr -- TODO FIXME NOW + + +openNursery = [ + -- Hp = CurrentNursery->free - 1; + CmmAssign hp (cmmOffsetW (CmmLoad nursery_bdescr_free wordRep) (-1)), + + -- HpLim = CurrentNursery->start + + -- CurrentNursery->blocks*BLOCK_SIZE_W - 1; + CmmAssign hpLim + (cmmOffsetExpr + (CmmLoad nursery_bdescr_start wordRep) + (cmmOffset + (CmmMachOp mo_wordMul [ + CmmMachOp (MO_S_Conv I32 wordRep) + [CmmLoad nursery_bdescr_blocks I32], + CmmLit (mkIntCLit bLOCK_SIZE) + ]) + (-1) + ) + ) + ] + + +nursery_bdescr_free = cmmOffset stgCurrentNursery oFFSET_bdescr_free +nursery_bdescr_start = cmmOffset stgCurrentNursery oFFSET_bdescr_start +nursery_bdescr_blocks = cmmOffset stgCurrentNursery oFFSET_bdescr_blocks + +tso_SP = tsoFieldB oFFSET_StgTSO_sp +tso_STACK = tsoFieldB oFFSET_StgTSO_stack +tso_CCCS = tsoProfFieldB oFFSET_StgTSO_CCCS + +-- The TSO struct has a variable header, and an optional StgTSOProfInfo in +-- the middle. The fields we're interested in are after the StgTSOProfInfo. +tsoFieldB :: ByteOff -> ByteOff +tsoFieldB off + | opt_SccProfilingOn = off + sIZEOF_StgTSOProfInfo + fixedHdrSize * wORD_SIZE + | otherwise = off + fixedHdrSize * wORD_SIZE + +tsoProfFieldB :: ByteOff -> ByteOff +tsoProfFieldB off = off + fixedHdrSize * wORD_SIZE + +stgSp = CmmReg sp +stgHp = CmmReg hp +stgCurrentTSO = CmmReg currentTSO +stgCurrentNursery = CmmReg currentNursery + +sp = CmmGlobal Sp +spLim = CmmGlobal SpLim +hp = CmmGlobal Hp +hpLim = CmmGlobal HpLim +currentTSO = CmmGlobal CurrentTSO +currentNursery = CmmGlobal CurrentNursery --------------------------------------------------------------------------------- +----------------------------------------------------------------------------- -- Functions that generate CmmStmt sequences -- for packing/unpacking continuations -- and entering/exiting functions -exit_function :: StackFormat -> CmmExpr -> CmmActuals -> [CmmStmt] -exit_function (StackFormat curr_id curr_frame_size curr_offsets) target arguments - = adjust_spReg ++ jump where - adjust_spReg = [ - CmmAssign spReg - (CmmRegOff spReg (curr_frame_size*wORD_SIZE))] +tail_call :: WordOff -> CmmExpr -> CmmActuals -> [CmmStmt] +tail_call spRel target arguments + = store_arguments ++ adjust_spReg ++ jump where + store_arguments = + [stack_put spRel expr offset + | ((expr, _), StackParam offset) <- argument_formats] ++ + [global_put expr global + | ((expr, _), RegisterParam global) <- argument_formats] + adjust_spReg = + if spRel == 0 + then [] + else [CmmAssign spReg (CmmRegOff spReg (spRel*wORD_SIZE))] jump = [CmmJump target arguments] -enter_function :: WordOff -> [CmmStmt] -enter_function max_frame_size + argument_formats = assignArguments (cmmExprRep . fst) arguments + +gc_stack_check' stack_use arg_stack max_frame_size = + if max_frame_size > arg_stack + then [CmmAssign stack_use (CmmRegOff spReg (-max_frame_size*wORD_SIZE))] + else [CmmAssign stack_use (CmmReg spLimReg)] + -- Trick the optimizer into eliminating the branch for us + +gc_stack_check :: BlockId -> WordOff -> [CmmStmt] +gc_stack_check gc_block max_frame_size = check_stack_limit where check_stack_limit = [ CmmCondBranch (CmmMachOp (MO_U_Lt $ cmmRegRep spReg) - [CmmRegOff spReg max_frame_size, CmmReg spLimReg]) + [CmmRegOff spReg (-max_frame_size*wORD_SIZE), + CmmReg spLimReg]) gc_block] - gc_block = undefined -- TODO: get stack and heap checks to go to same --- TODO: fix branches to proc point (we have to insert a new block to marshel the continuation) -pack_continuation :: StackFormat -> StackFormat -> [CmmStmt] -pack_continuation (StackFormat curr_id curr_frame_size curr_offsets) - (StackFormat cont_id cont_frame_size cont_offsets) - = save_live_values ++ set_stack_header ++ adjust_spReg where + +-- TODO: fix branches to proc point +-- (we have to insert a new block to marshel the continuation) + + +pack_continuation :: Bool -- ^ Whether to set the top/header + -- of the stack. We only need to + -- set it if we are calling down + -- as opposed to continuation + -- adaptors. + -> ContinuationFormat -- ^ The current format + -> ContinuationFormat -- ^ The return point format + -> [CmmStmt] +pack_continuation allow_header_set + (ContinuationFormat _ curr_id curr_frame_size _) + (ContinuationFormat _ cont_id cont_frame_size live_regs) + = store_live_values ++ set_stack_header where -- TODO: only save variables when actually needed - save_live_values = - [CmmStore - (CmmRegOff - spReg (wORD_SIZE*(curr_frame_size - cont_frame_size + offset))) - (CmmReg reg) + -- (may be handled by latter pass) + store_live_values = + [stack_put spRel (CmmReg (CmmLocal reg)) offset | (reg, offset) <- cont_offsets] - set_stack_header = -- TODO: only set when needed - [CmmStore (CmmRegOff spReg (wORD_SIZE*(curr_frame_size - cont_frame_size))) continuation_function] - continuation_function = CmmLit $ CmmLabel $ mkReturnPtLabel {-TODO: use the correct function -} $ getUnique cont_id - adjust_spReg = - if curr_frame_size == cont_frame_size - then [] - else [CmmAssign spReg (CmmRegOff spReg ((curr_frame_size - cont_frame_size)*wORD_SIZE))] + set_stack_header = + if needs_header_set && allow_header_set + then [stack_put spRel continuation_function 0] + else [] + + -- TODO: factor with function_entry and CmmInfo.hs(?) + cont_offsets = mkOffsets label_size live_regs + + label_size = 1 :: WordOff + + mkOffsets size [] = [] + mkOffsets size (Nothing:regs) = mkOffsets (size+1) regs + mkOffsets size (Just reg:regs) = (reg, size):mkOffsets (size + width) regs + where + width = machRepByteWidth (localRegRep reg) `quot` wORD_SIZE + -- TODO: it would be better if we had a machRepWordWidth + + spRel = curr_frame_size - cont_frame_size + continuation_function = CmmLit $ CmmLabel $ fromJust cont_id + needs_header_set = + case (curr_id, cont_id) of + (Just x, Just y) -> x /= y + _ -> isJust cont_id -- Lazy adjustment of stack headers assumes all blocks -- that could branch to eachother (i.e. control blocks) -- have the same stack format (this causes a problem -- only for proc-point). -unpack_continuation :: StackFormat -> [CmmStmt] -unpack_continuation (StackFormat curr_id curr_frame_size curr_offsets) - = load_live_values where +function_entry :: ContinuationFormat -> [CmmStmt] +function_entry (ContinuationFormat formals _ _ live_regs) + = load_live_values ++ load_args where -- TODO: only save variables when actually needed + -- (may be handled by latter pass) load_live_values = - [CmmAssign - reg - (CmmLoad (CmmRegOff spReg (wORD_SIZE*offset)) (cmmRegRep reg)) + [stack_get 0 reg offset | (reg, offset) <- curr_offsets] + load_args = + [stack_get 0 reg offset + | (reg, StackParam offset) <- argument_formats] ++ + [global_get reg global + | (reg, RegisterParam global) <- argument_formats] ------------------------------------------------------------------------------ --- Breaking basic blocks on function calls ------------------------------------------------------------------------------ + argument_formats = assignArguments (localRegRep) formals ------------------------------------------------------------------------------ --- Takes a basic block and breaks it up into a list of broken blocks --- --- Takes a basic block and returns a list of basic blocks that --- each have at most 1 CmmCall in them which must occur at the end. --- Also returns with each basic block, the variables that will --- be arguments to the continuation of the block once the call (if any) --- returns. - -breakBlock :: [Unique] -> CmmBasicBlock -> BlockEntryInfo -> [BrokenBlock] -breakBlock uniques (BasicBlock ident stmts) entry = - breakBlock' uniques ident entry [] [] stmts where - breakBlock' uniques current_id entry exits accum_stmts stmts = - case stmts of - [] -> panic "block doesn't end in jump, goto or return" - [CmmJump target arguments] -> - [BrokenBlock current_id entry accum_stmts - exits - (FinalJump target arguments)] - [CmmReturn arguments] -> - [BrokenBlock current_id entry accum_stmts - exits - (FinalReturn arguments)] - [CmmBranch target] -> - [BrokenBlock current_id entry accum_stmts - (target:exits) - (FinalBranch target)] - [CmmSwitch expr targets] -> - [BrokenBlock current_id entry accum_stmts - (mapMaybe id targets ++ exits) - (FinalSwitch expr targets)] - (CmmJump _ _:_) -> - panic "jump in middle of block" - (CmmReturn _:_) -> - panic "return in middle of block" - (CmmBranch _:_) -> - panic "branch in middle of block" - (CmmSwitch _ _:_) -> - panic ("switch in middle of block" ++ (showSDoc $ ppr stmts)) - (CmmCall target results arguments saves:stmts) -> block : rest - where - new_id = BlockId $ head uniques - block = BrokenBlock current_id entry accum_stmts - (new_id:exits) - (FinalCall new_id target results arguments saves) - rest = breakBlock' (tail uniques) new_id - (ContinuationEntry results) [] [] stmts - (s@(CmmCondBranch test target):stmts) -> - breakBlock' uniques current_id entry - (target:exits) (accum_stmts++[s]) stmts - (s:stmts) -> - breakBlock' uniques current_id entry - exits (accum_stmts++[s]) stmts + -- TODO: eliminate copy/paste with pack_continuation + curr_offsets = mkOffsets label_size live_regs --------------------------------- --- Convert from a BrokenBlock --- to a CmmBasicBlock so the --- liveness analysis can run --- on it. --------------------------------- -cmmBlockFromBrokenBlock :: BrokenBlock -> CmmBasicBlock -cmmBlockFromBrokenBlock (BrokenBlock ident _ stmts _ exit) = - BasicBlock ident (stmts++exit_stmt) - where - exit_stmt = - case exit of - FinalBranch target -> [CmmBranch target] - FinalReturn arguments -> [CmmReturn arguments] - FinalJump target arguments -> [CmmJump target arguments] - FinalSwitch expr targets -> [CmmSwitch expr targets] - FinalCall branch_target call_target results arguments saves -> - [CmmCall call_target results arguments saves, - CmmBranch branch_target] + label_size = 1 :: WordOff + + mkOffsets size [] = [] + mkOffsets size (Nothing:regs) = mkOffsets (size+1) regs + mkOffsets size (Just reg:regs) = (reg, size):mkOffsets (size + width) regs + where + width = machRepByteWidth (localRegRep reg) `quot` wORD_SIZE + -- TODO: it would be better if we had a machRepWordWidth ----------------------------------------------------------------------------- --- CPS a single CmmTop (proceedure) +-- Section: Stack and argument register puts and gets ----------------------------------------------------------------------------- +-- TODO: document + +-- |Construct a 'CmmStmt' that will save a value on the stack +stack_put :: WordOff -- ^ Offset from the real 'Sp' that 'offset' + -- is relative to (added to offset) + -> CmmExpr -- ^ What to store onto the stack + -> WordOff -- ^ Where on the stack to store it + -- (positive <=> higher addresses) + -> CmmStmt +stack_put spRel expr offset = + CmmStore (CmmRegOff spReg (wORD_SIZE*(spRel + offset))) expr -cpsProc :: UniqSupply -> CmmTop -> [CmmTop] -cpsProc uniqSupply x@(CmmData _ _) = [x] -cpsProc uniqSupply x@(CmmProc info_table ident params blocks) = - --[CmmProc info_table ident params cps_blocks] - cps_continuations - where - uniqes :: [[Unique]] - uniqes = map uniqsFromSupply $ listSplitUniqSupply uniqSupply - - -- Break the block at each function call - broken_blocks :: [BrokenBlock] - broken_blocks = concat $ zipWith3 breakBlock uniqes blocks - (FunctionEntry ident params:repeat ControlEntry) - - -- Calculate live variables for each broken block - live :: BlockEntryLiveness - live = cmmLiveness $ map cmmBlockFromBrokenBlock broken_blocks - - proc_points :: UniqSet BlockId - proc_points = calculateProcPoints broken_blocks - - continuations :: [Continuation] - continuations = map (buildContinuation proc_points (blocksToBlockEnv broken_blocks)) (uniqSetToList proc_points) - - -- TODO: insert proc point code here - -- * Branches and switches to proc points may cause new blocks to be created - -- (or proc points could leave behind phantom blocks that just jump to them) - -- * Proc points might get some live variables passed as arguments - - -- TODO: let blocks_with_live = map (cmmLivenessComment live . snd) broken_blocks - - --procs = groupBlocksIntoContinuations live broken_blocks - - -- Select the stack format on entry to each block - formats :: BlockEnv StackFormat - formats = selectStackFormat live broken_blocks - - formats2 :: [(CLabel, StackFormat)] - formats2 = selectStackFormat2 live continuations - - -- Do the actual CPS transform - cps_blocks :: [CmmBasicBlock] - cps_blocks = map (constructContinuation2 formats) broken_blocks - - cps_continuations :: [CmmTop] - cps_continuations = map (constructContinuation formats2) continuations - --------------------------------------------------------------------------------- -cmmCPS :: DynFlags - -> [Cmm] -- C-- with Proceedures - -> IO [Cmm] -- Output: CPS transformed C-- - -cmmCPS dflags abstractC = do - when (dopt Opt_DoCmmLinting dflags) $ - do showPass dflags "CmmLint" - case firstJust $ map cmmLint abstractC of - Just err -> do printDump err - ghcExit dflags 1 - Nothing -> return () - showPass dflags "CPS" - -- TODO: check for use of branches to non-existant blocks - -- TODO: check for use of Sp, SpLim, R1, R2, etc. - -- TODO: find out if it is valid to create a new unique source like this - uniqSupply <- mkSplitUniqSupply 'p' - let supplies = listSplitUniqSupply uniqSupply - let continuationC = zipWith (\s (Cmm c) -> Cmm $ concat $ zipWith (cpsProc) (listSplitUniqSupply s) c) supplies abstractC +-------------------------------- +-- |Construct a +stack_get :: WordOff + -> LocalReg + -> WordOff + -> CmmStmt +stack_get spRel reg offset = + CmmAssign (CmmLocal reg) + (CmmLoad (CmmRegOff spReg (wORD_SIZE*(spRel + offset))) + (localRegRep reg)) +global_put :: CmmExpr -> GlobalReg -> CmmStmt +global_put expr global = CmmAssign (CmmGlobal global) expr +global_get :: LocalReg -> GlobalReg -> CmmStmt +global_get reg global = CmmAssign (CmmLocal reg) (CmmReg (CmmGlobal global)) - dumpIfSet_dyn dflags Opt_D_dump_cps_cmm "CPS Cmm" (pprCmms continuationC) - -- TODO: add option to dump Cmm to file - return continuationC