X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fcmm%2FCmmCPS.hs;h=17c11ce2646c1a17de576c4642beac417508a725;hb=7fc01c4671980ea3c66d549c0ece4d82fd3f5ade;hp=88d2585c575919203a7774434649dead7872a3f1;hpb=b4fd46494dc922a8e1134c9396cada1f10e74e55;p=ghc-hetmet.git diff --git a/compiler/cmm/CmmCPS.hs b/compiler/cmm/CmmCPS.hs index 88d2585..17c11ce 100644 --- a/compiler/cmm/CmmCPS.hs +++ b/compiler/cmm/CmmCPS.hs @@ -1,15 +1,24 @@ -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" +import BlockId import Cmm import CmmLint import PprCmm -import Dataflow -- (fixedpoint, cmmLivenessComment, cmmLiveness, CmmLive) +import CmmLive +import CmmBrokenBlock +import CmmProcPoint +import CmmCallConv +import CmmCPSGen +import CmmUtils -import MachOp -import ForeignCall +import ClosureInfo import CLabel import SMRep import Constants @@ -19,471 +28,385 @@ import ErrUtils import Maybes import Outputable import UniqSupply -import UniqFM import UniqSet import Unique -import Monad -import IO +import Control.Monad + +----------------------------------------------------------------------------- +-- |Top level driver for the CPS pass +----------------------------------------------------------------------------- +cmmCPS :: DynFlags -- ^ Dynamic flags: -dcmm-lint -ddump-cps-cmm + -> [Cmm] -- ^ Input C-- with Proceedures + -> IO [Cmm] -- ^ Output CPS transformed C-- +cmmCPS dflags cmm_with_calls + = do { when (dopt Opt_DoCmmLinting dflags) $ + do showPass dflags "CmmLint" + case firstJust $ map cmmLint cmm_with_calls 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 cpsd_cmm = zipWith doCpsProc supplies cmm_with_calls + + ; dumpIfSet_dyn dflags Opt_D_dump_cps_cmm "CPS Cmm" (pprCmms cpsd_cmm) --------------------------------------------------------------------------------- --- Monad for the CPSer --- Contains: --- * State for the uniqSupply - -data CPSState = CPSState { cps_uniqs :: UniqSupply } - -data CPS a = CPS { runCPS :: CPSState -> (CPSState, a) } - -instance Monad CPS where - return a = CPS $ \s -> (s, a) - (CPS m) >>= f = CPS $ \s -> - let (s', m') = m s - in runCPS (f m') s' - --------------------------------------------------------------------------------- --- Utility functions - -getState = CPS $ \s -> (s, s) -putState s = CPS $ \_ -> (s, ()) - -newLabelCPS = do - state <- getState - let (us1, us2) = splitUniqSupply (cps_uniqs state) - putState $ state { cps_uniqs = us1 } - return $ BlockId (uniqFromSupply us2) - -mapMCmmTop :: (Monad m) => (CmmTop -> m [CmmTop]) -> Cmm -> m Cmm -mapMCmmTop f (Cmm xs) = liftM Cmm $ liftM concat $ mapM f xs - --------------------------------------------------------------------------------- - --- The format for the call to a continuation --- The fst is the arguments that must be passed to the continuation --- by the continuation's caller. --- The snd is the live values that must be saved on stack. --- A Nothing indicates an ignored slot. --- The head of each list is the stack top or the first parameter. - --- The format for live values for a particular continuation --- All on stack for now. --- Head element is the top of the stack (or just under the header). --- Nothing means an empty slot. --- Future possibilities include callee save registers (i.e. passing slots in register) --- and heap memory (not sure if that's usefull at all though, but it may --- be worth exploring the design space). - -data BrokenBlock - = BrokenBlock - BlockId -- Like a CmmBasicBlock - BlockEntryInfo -- How this block can be entered - [CmmStmt] -- Like a CmmBasicBlock (but without - -- the last statement) - BlockExitInfo -- How the block can be left - -data BlockEntryInfo - = FunctionEntry -- Beginning of function - - | ContinuationEntry -- Return point of a call - CmmFormals {- return values -} - -- TODO | ProcPointEntry {- no return values, but some live might end up as params -} - - | ControlEntry -- A label in the input - -data BlockExitInfo - = ControlExit [BlockId] -- blocks branched to conditionally - BlockId -- next block (must be a ControlEntry) - - | ReturnExit [BlockId] -- blocks branched to conditionally - CmmActuals -- return values - - | TailCallExit [BlockId] -- blocks branched to conditionally - CmmExpr -- the function to call - CmmActuals -- arguments to call - - | CallExit [BlockId] -- blocks branched to conditionally - 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) - -- TODO: | ProcPointExit (needed?) - -data CPSBlockInfo - = ControlBlock -- Consider whether a proc-point might want arguments on stack - | ContinuationBlock [(CmmReg,MachHint)] {- params -} - | EntryBlock - ---type StackFormat = [Maybe LocalReg] -- TODO: consider params as part of format -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 -} - --- 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 + -- TODO: add option to dump Cmm to file --------------------------------------------------------------------------------- --- For now just select the continuation orders in the order they are in the set with no gaps --- TODO: select a format that keeps blocks that can jump to each other the same --- Assumed that jumps, calls -selectStackFormat :: UniqFM {-BlockId-} CmmFormals -> UniqFM {-BlockId-} CmmLive -> UniqFM {-BlockId-} [(CPSBlockInfo, CmmBasicBlock)] -> UniqFM {-BlockId-} StackFormat -selectStackFormat = undefined -{- -selectStackFormat param live blocks = fixedpoint -listToUFM $ map live_to_format $ ufmToList live + ; return cpsd_cmm } + + +----------------------------------------------------------------------------- +-- |CPS a single CmmTop (proceedure) +-- Only 'CmmProc' are transformed 'CmmData' will be left alone. +----------------------------------------------------------------------------- + +doCpsProc :: UniqSupply -> Cmm -> Cmm +doCpsProc s (Cmm c) + = Cmm $ concat $ zipWith cpsProc (listSplitUniqSupply s) c + +cpsProc :: UniqSupply + -> CmmTop -- ^Input procedure + -> [CmmTop] -- ^Output procedures; + -- a single input procedure is converted to + -- multiple output procedures + +-- Data blocks don't need to be CPS transformed +cpsProc _ proc@(CmmData _ _) = [proc] + +-- Empty functions just don't work with the CPS algorithm, but +-- they don't need the transformation anyway so just output them directly +cpsProc _ proc@(CmmProc _ _ _ (ListGraph [])) + = pprTrace "cpsProc: unexpected empty proc" (ppr proc) [proc] + +-- CPS transform for those procs that actually need it +-- The plan is this: +-- +-- * Introduce a stack-check block as the first block +-- * The first blocks gets a FunctionEntry; the rest are ControlEntry +-- * Now break each block into a bunch of blocks (at call sites); +-- all but the first will be ContinuationEntry +-- +cpsProc uniqSupply (CmmProc info ident params (ListGraph blocks)) = cps_procs + where + -- We need to be generating uniques for several things. + -- We could make this function monadic to handle that + -- but since there is no other reason to make it monadic, + -- we instead will just split them all up right here. + (uniqSupply1, uniqSupply2) = splitUniqSupply uniqSupply + uniques :: [[Unique]] + uniques = map uniqsFromSupply $ listSplitUniqSupply uniqSupply1 + (stack_check_block_unique:stack_use_unique:adaptor_uniques) : + block_uniques = uniques + proc_uniques = map (map (map uniqsFromSupply . listSplitUniqSupply) . listSplitUniqSupply) $ listSplitUniqSupply uniqSupply2 + + stack_use = CmmLocal (LocalReg stack_use_unique (cmmRegType spReg)) + stack_check_block_id = BlockId stack_check_block_unique + stack_check_block = make_stack_check stack_check_block_id info stack_use (blockId $ head blocks) + + forced_blocks = stack_check_block : blocks + + CmmInfo maybe_gc_block_id update_frame _ = info + + -- 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 (maybeToList maybe_gc_block_id)) + block_uniques + forced_blocks + (FunctionEntry 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 = map (gatherBlocksIntoContinuation live proc_points block_env) + (uniqSetToList proc_points) + + -- 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, WordOff, [(CLabel, ContinuationFormat)]) + formats'@(_, _, format_list) = processFormats formats update_frame continuations + + -- Update the info table data on the continuations with + -- the selected stack formats. + continuations' :: [Continuation CmmInfo] + continuations' = map (applyContinuationFormat format_list) continuations + + -- Do the actual CPS transform. + cps_procs :: [CmmTop] + cps_procs = zipWith (continuationToProc formats' stack_use) proc_uniques continuations' + +make_stack_check :: BlockId -> CmmInfo -> CmmReg -> BlockId + -> GenBasicBlock CmmStmt +make_stack_check stack_check_block_id info stack_use next_block_id = + BasicBlock stack_check_block_id $ + check_stmts ++ [CmmBranch next_block_id] where - live_to_format (unique, live) = (unique, format) where - format = foldl extend_format - (StackFormat (BlockId unique) 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 :: UniqFM {-BlockId-} CmmLive -> [BrokenBlock] -> UniqFM {-BlockId-} StackFormat -selectStackFormat2 live blocks = fixedpoint dependants update (map brokenBlockId blocks) emptyUFM where - blocks_ufm = listToUFM $ map (\b -> (brokenBlockId b, b)) blocks - dependants ident = - case lookupWithDefaultUFM blocks_ufm (panic "TODO") ident of - (BrokenBlock _ _ _ (ControlExit exits next)) -> next:exits - (BrokenBlock _ _ _ (ReturnExit exits _)) -> exits - (BrokenBlock _ _ _ (TailCallExit exits _ _)) -> exits - (BrokenBlock _ _ _ (CallExit exits _ _ _ _ _)) -> exits - update ident cause formats = - let BrokenBlock _ entry _ _ = lookupWithDefaultUFM blocks_ufm (panic "unknown BlockId in selectStackFormat:live") ident in - case cause of - -- Propagate only to blocks entered by branches (not function entry blocks or continuation entry blocks) - Just cause_name -> - let cause_format = lookupWithDefaultUFM formats (panic "update signaled for block not in format") cause_name - in case entry of - ControlEntry -> Just $ addToUFM formats ident cause_format - FunctionEntry -> Nothing - ContinuationEntry _ -> Nothing - -- Do initial calculates for function blocks - Nothing -> - case entry of - ControlEntry -> Nothing - FunctionEntry -> Just $ addToUFM formats ident $ StackFormat ident 0 [] - ContinuationEntry _ -> Just $ addToUFM formats ident $ live_to_format ident $ lookupWithDefaultUFM live (panic "TODO") ident - 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) - -slot_size reg = ((machRepByteWidth (localRegRep reg) - 1) `div` wORD_SIZE) + 1 - -transformReturn :: UniqFM {-BlockId-} CPSBlockInfo -> UniqFM {-BlockId-} StackFormat -> CmmBasicBlock -> CmmBasicBlock -transformReturn block_infos formats (BasicBlock ident stmts) = - -- NOTE: assumes that return/jump can *only* appear at end of block - case last stmts of - CmmReturn arguments -> - BasicBlock ident $ - (init stmts) ++ - exit_function curr_format (CmmLoad (CmmReg spReg) wordRep) arguments - CmmJump target arguments -> - BasicBlock ident $ - (init stmts) ++ - exit_function curr_format target arguments - _ -> BasicBlock ident stmts - where - curr_format = lookupWithDefaultUFM formats (panic $ "format: unknown block " ++ (showSDoc $ ppr $ getUnique ident)) ident - -destructContinuation :: UniqFM {-BlockId-} CPSBlockInfo -> UniqFM {-BlockId-} StackFormat -> CmmBasicBlock -> CmmBasicBlock -destructContinuation block_infos formats (BasicBlock ident stmts) = - case info of - ControlBlock -> BasicBlock ident stmts - ContinuationBlock _ -> BasicBlock ident (unpack_continuation curr_format ++ stmts) - where - info = lookupWithDefaultUFM block_infos (panic $ "info: unknown block " ++ (showSDoc $ ppr $ getUnique ident)) ident - curr_format = lookupWithDefaultUFM formats (panic $ "format: unknown block " ++ (showSDoc $ ppr $ getUnique ident)) ident - -constructContinuation2 :: UniqFM {-BlockId-} StackFormat -> BrokenBlock -> CmmBasicBlock -constructContinuation2 formats (BrokenBlock ident entry stmts exit) = - BasicBlock ident (prefix++stmts++postfix) + check_stmts = + case info of + -- If we are given a stack check handler, + -- then great, well check the stack. + CmmInfo (Just gc_block) _ _ + -> [CmmCondBranch + (CmmMachOp (MO_U_Lt (typeWidth (cmmRegType spReg))) + [CmmReg stack_use, CmmReg spLimReg]) + gc_block] + -- If we aren't given a stack check handler, + -- then humph! we just won't check the stack for them. + CmmInfo Nothing _ _ + -> [] +----------------------------------------------------------------------------- + +collectNonProcPointTargets :: + UniqSet BlockId -> BlockEnv BrokenBlock + -> 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 + (map (:[]) targets) where - curr_format = lookupWithDefaultUFM formats (panic $ "format: unknown block " ++ (showSDoc $ ppr $ getUnique ident)) ident - prefix = case entry of - ControlEntry -> [] - FunctionEntry -> [] - ContinuationEntry formals -> unpack_continuation curr_format - postfix = case exit of - ControlExit _ next -> [CmmBranch next] - ReturnExit _ arguments -> exit_function curr_format (CmmLoad (CmmReg spReg) wordRep) arguments - TailCallExit _ target arguments -> exit_function curr_format target arguments - -- TODO: do something about global saves - CallExit _ next (CmmForeignCall target CmmCallConv) results arguments saves -> - let cont_format = lookupWithDefaultUFM formats (panic $ "format: unknown block " ++ (showSDoc $ ppr $ getUnique next)) next - in pack_continuation curr_format cont_format ++ - [CmmJump target arguments] - CallExit _ next _ results arguments saves -> panic "unimplemented CmmCall" - -constructContinuation :: UniqFM {-BlockId-} CPSBlockInfo -> UniqFM {-BlockId-} StackFormat -> CmmBasicBlock -> CmmBasicBlock -constructContinuation block_infos formats (BasicBlock ident stmts) = - case last $ init stmts of - -- TODO: global_saves - --CmmCall (CmmForeignCall target CmmCallConv) results arguments (Just []) -> --TODO: handle globals - CmmCall (CmmForeignCall target CmmCallConv) results arguments _ -> - BasicBlock ident $ - init (init stmts) ++ - pack_continuation curr_format cont_format ++ - [CmmJump target arguments] - CmmCall target results arguments _ -> panic "unimplemented CmmCall" - -- TODO: branches for proc-points - -- _ -> BasicBlock ident $ (init stmts) ++ build_block_branch - _ -> BasicBlock ident stmts - where - info = lookupWithDefaultUFM block_infos (panic $ "info: unknown block " ++ (showSDoc $ ppr $ getUnique next_block)) next_block - cont_format = lookupWithDefaultUFM formats (panic $ "format: unknown block " ++ (showSDoc $ ppr $ getUnique next_block)) next_block - curr_format = lookupWithDefaultUFM formats (panic $ "format: unknown block " ++ (showSDoc $ ppr $ getUnique next_block)) ident - next_block = case last stmts of - CmmBranch next -> next - -- TODO: blocks with jump at end - -- TODO: blocks with return at end - _ -> panic $ "basic block without a branch at the end (unimplemented) " ++ (showSDoc $ ppr $ stmts) - next_block_as_proc_expr = CmmLit $ CmmLabel $ mkReturnPtLabel $ getUnique next_block - block_needs_call = True -- TODO: use a table (i.e. proc-point) - build_block_branch = - if block_needs_call - then [CmmJump next_block_as_proc_expr [] {- TODO: pass live -}] {- NOTE: a block can never be both a continuation and a controll block -} - else [CmmBranch next_block] + blocks' = map (lookupWithDefaultBEnv 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) + +-- 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 -> Continuation (Either C_SRT CmmInfo) +gatherBlocksIntoContinuation live proc_points blocks start = + Continuation info_table clabel params is_gc_cont body + where + children = (collectNonProcPointTargets proc_points blocks (unitUniqSet start) [start]) `minusUniqSet` (unitUniqSet start) + start_block = lookupWithDefaultBEnv blocks unknown_block start + children_blocks = map (lookupWithDefaultBEnv blocks unknown_block) (uniqSetToList children) + unknown_block :: a -- Used at more than one type + unknown_block = panic "unknown block in gatherBlocksIntoContinuation" + body = start_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 (CmmInfo Nothing Nothing CmmNonInfoTable) + + is_gc_cont = case start_block_entry of + FunctionEntry _ _ _ -> False + ContinuationEntry _ _ gc_cont -> gc_cont + ControlEntry -> False + + start_block_entry = brokenBlockEntry start_block + clabel = case start_block_entry of + FunctionEntry _ label _ -> label + _ -> mkReturnPtLabel $ getUnique start + params = case start_block_entry of + FunctionEntry _ _ args -> args + ContinuationEntry args _ _ -> args + ControlEntry -> + uniqSetToList $ + lookupWithDefaultBEnv live unknown_block start + -- it's a proc-point, pass lives in parameter registers -------------------------------------------------------------------------------- --- 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))] - jump = [CmmJump target arguments] - -enter_function :: WordOff -> [CmmStmt] -enter_function max_frame_size - = check_stack_limit where - check_stack_limit = [ - CmmCondBranch - (CmmMachOp (MO_U_Lt $ cmmRegRep spReg) - [CmmRegOff spReg max_frame_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: only save variables when actually needed - save_live_values = - [CmmStore - (CmmRegOff - spReg (wORD_SIZE*(curr_frame_size - cont_frame_size + offset))) - (CmmReg reg) - | (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 $ 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))] - --- 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 - -- TODO: only save variables when actually needed - load_live_values = - [CmmAssign - reg - (CmmLoad (CmmRegOff spReg (wORD_SIZE*offset)) (cmmRegRep reg)) - | (reg, offset) <- curr_offsets] - --- TODO: TBD when to adjust the stack - -cpsProc :: CmmTop -> CPS [CmmTop] -cpsProc x@(CmmData _ _) = return [x] -cpsProc x@(CmmProc info_table ident params blocks) = do - - broken_blocks <- liftM concat $ mapM breakBlock blocks - broken_blocks2 <- liftM concat (zipWithM breakBlock2 blocks (FunctionEntry:repeat ControlEntry)) - -- broken_blocks :: [BrokenBlock] - - let live = cmmLiveness (map snd broken_blocks) - let live2 :: BlockEntryLiveness - live2 = cmmLiveness2 broken_blocks2 - - let blocks_with_live = map (cmmLivenessComment live . snd) broken_blocks - - let formats = selectStackFormat (panic "params to selectStackFormat" {-TODO-}) live (undefined) - let formats2 :: BlockEnv StackFormat -- Stack format on entry - formats2 = selectStackFormat2 live2 broken_blocks2 - - let block_infos = listToUFM $ map (\(info, block) -> (blockId block, info)) broken_blocks - --let blocks_with_live' = map (constructContinuation block_infos formats) blocks_with_live - --let blocks_with_live'' = map (destructContinuation block_infos formats) blocks_with_live' - --let blocks_with_live''' = map (transformReturn block_infos formats) blocks_with_live'' - - return $ [CmmProc info_table ident params $ map (constructContinuation2 formats2) broken_blocks2] -{- - return $ [CmmProc info_table ident params $ - map (constructContinuation block_infos formats . - destructContinuation block_infos formats . - transformReturn block_infos formats) - blocks_with_live] --} +-- For now just select the continuation orders in the order they are in the set with no gaps --------------------------------------------------------------------------------- --- 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. - -cmmBlockifyCalls :: [CmmBasicBlock] -> CPS [(CPSBlockInfo, CmmBasicBlock)] -cmmBlockifyCalls blocks = liftM concat $ mapM breakBlock blocks - --- [(CmmReg,MachHint)] is the results from the previous block that are expected as parameters ---breakBlock :: CmmBasicBlock -> CPS [(Maybe BlockId, CmmBasicBlock)] -breakBlock :: CmmBasicBlock -> CPS [(CPSBlockInfo, CmmBasicBlock)] -breakBlock (BasicBlock ident stmts) = breakBlock' ident ControlBlock [] stmts - -breakBlock' current_id block_info accum_stmts [] = - return [(block_info, BasicBlock current_id accum_stmts)] --- TODO: notice a call just before a branch, jump, call, etc. -breakBlock' current_id block_info accum_stmts (stmt@(CmmCall _ results _ _):stmts) = do - new_id <- newLabelCPS - let new_block = (block_info, BasicBlock current_id (accum_stmts ++ [stmt, CmmBranch new_id])) - rest <- breakBlock' new_id (ContinuationBlock results) [] stmts - return $ (new_block:rest) -breakBlock' current_id arguments accum_stmts (stmt:stmts) = - breakBlock' current_id arguments (accum_stmts ++ [stmt]) stmts - -breakBlock2 (BasicBlock ident stmts) entry = breakBlock2' ident entry [] [] stmts - -breakBlock2' current_id block_info exits accum_stmts [] = - panic "block doesn't end in jump, goto or return" -breakBlock2' current_id entry exits accum_stmts [CmmJump target arguments] = - return [BrokenBlock current_id entry accum_stmts (TailCallExit exits target arguments)] -breakBlock2' current_id entry exits accum_stmts [CmmReturn arguments] = - return [BrokenBlock current_id entry accum_stmts (ReturnExit exits arguments)] -breakBlock2' current_id entry exits accum_stmts [CmmBranch target] = - return [BrokenBlock current_id entry accum_stmts (ControlExit exits target)] -breakBlock2' _ _ _ _ (CmmJump _ _:_) = panic "jump in middle of block" -breakBlock2' _ _ _ _ (CmmReturn _:_) = panic "return in middle of block" -breakBlock2' _ _ _ _ (CmmBranch _:_) = panic "branch in middle of block" -breakBlock2' _ _ _ _ (CmmSwitch _ _:_) = panic "switch in block not implemented" -breakBlock2' current_id entry exits accum_stmts (CmmCall target results arguments saves:stmts) = do - new_id <- newLabelCPS - rest <- breakBlock2' new_id (ContinuationEntry results) [] [] stmts - return $ BrokenBlock current_id entry accum_stmts (CallExit exits new_id target results arguments saves) : rest -breakBlock2' current_id entry exits accum_stmts (s@(CmmCondBranch test target):stmts) = - breakBlock2' current_id entry (target:exits) (accum_stmts++[s]) stmts -breakBlock2' current_id entry exits accum_stmts (s:stmts) = - breakBlock2' current_id entry exits (accum_stmts++[s]) stmts - -brokenBlockTargets (BrokenBlock _ _ _ (TailCallExit exits _ _)) = exits -brokenBlockTargets (BrokenBlock _ _ _ (ReturnExit exits _)) = exits -brokenBlockTargets (BrokenBlock _ _ _ (ControlExit exits target)) = target:exits -brokenBlockTargets (BrokenBlock _ _ _ (CallExit exits next _ _ _ _)) = next:exits - -brokenBlockId (BrokenBlock ident _ _ _) = ident - -cmmBrokenBlockSources :: - [BrokenBlock] -> UniqFM {-BlockId-} (UniqSet BlockId) -cmmBrokenBlockSources blocks = foldr aux emptyUFM blocks where - aux block sourcesUFM = - foldr add_source_edges sourcesUFM targets where - add_source_edges t ufm = - addToUFM_Acc (flip addOneToUniqSet) unitUniqSet ufm t ident - targets = brokenBlockTargets block - ident = brokenBlockId block - -cmmBrokenBlockNames :: [BrokenBlock] -> UniqFM {-BlockId-} BrokenBlock -cmmBrokenBlockNames blocks = listToUFM $ map block_name blocks where - block_name b = (brokenBlockId b, b) - -cmmBrokenBlockDependants :: UniqFM {-BlockId-} (UniqSet BlockId) -> BlockId -> [BlockId] -cmmBrokenBlockDependants sources ident = - uniqSetToList $ lookupWithDefaultUFM sources emptyUniqSet ident - -cmmBrokenBlockLive :: UniqFM {-BlockId-} CmmLive -> BrokenBlock -> CmmLive -cmmBrokenBlockLive other_live (BrokenBlock _ _ stmts exit) = - foldr ((.) . (cmmStmtLive other_live)) id stmts live_at_end +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 - live_at_end = - case exit of - ControlExit _ _ -> emptyUniqSet - ReturnExit _ actuals -> foldr ((.) . cmmExprLive) id (map fst actuals) emptyUniqSet - TailCallExit _ target actuals -> - cmmExprLive target $ foldr ((.) . cmmExprLive) id (map fst actuals) $ emptyUniqSet - CallExit _ _ target _ actuals live -> - target_liveness $ - foldr ((.) . cmmExprLive) id (map fst actuals) $ - emptyUniqSet - where - only_local_regs [] = [] - only_local_regs ((CmmGlobal _,_):args) = only_local_regs args - only_local_regs ((CmmLocal r,_):args) = r:only_local_regs args - target_liveness = - case target of - (CmmForeignCall target _) -> cmmExprLive target - (CmmPrim _) -> id - - -cmmBrokenBlockUpdate :: - UniqFM {-BlockId-} BrokenBlock - -> BlockId - -> Maybe BlockId - -> UniqFM {-BlockId-} CmmLive - -> Maybe (UniqFM {-BlockId-} CmmLive) -cmmBrokenBlockUpdate blocks node _ state = - let old_live = lookupWithDefaultUFM state (panic "unknown block id during liveness analysis") node - block = lookupWithDefaultUFM blocks (panic "unknown block id during liveness analysis") node - new_live = cmmBrokenBlockLive state block - in if (sizeUniqSet old_live) == (sizeUniqSet new_live) - then Nothing - else Just $ addToUFM state node new_live - - -cmmLiveness2 :: [BrokenBlock] -> UniqFM {-BlockId-} CmmLive -cmmLiveness2 blocks = - fixedpoint (cmmBrokenBlockDependants sources) (cmmBrokenBlockUpdate blocks') - (map brokenBlockId blocks) (listToUFM [(brokenBlockId b, emptyUniqSet) | b <- blocks]) where - sources = cmmBrokenBlockSources blocks - blocks' = cmmBrokenBlockNames blocks + -- User written continuations + selectContinuationFormat' (Continuation + (Right (CmmInfo _ _ (CmmInfoTable _ _ _ (ContInfo format _)))) + 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 _) 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 (formals, + Just label, + map Just $ uniqSetToList $ + lookupWithDefaultBEnv live unknown_block ident) + + unknown_block = panic "unknown BlockId in selectContinuationFormat" + +processFormats :: [(CLabel, (CmmFormals, Maybe CLabel, [Maybe LocalReg]))] + -> Maybe UpdateFrame + -> [Continuation (Either C_SRT CmmInfo)] + -> (WordOff, WordOff, [(CLabel, ContinuationFormat)]) +processFormats formats update_frame continuations = + (max_size + update_frame_size, update_frame_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 }) + + update_frame_size = case update_frame of + Nothing -> 0 + (Just (UpdateFrame _ args)) + -> label_size + update_size args + + update_size [] = 0 + update_size (expr:exprs) = width + update_size exprs + where + width = (widthInBytes $ typeWidth $ cmmExprType expr) `quot` wORD_SIZE + -- TODO: it would be better if we had a machRepWordWidth + + -- 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 = (widthInBytes $ typeWidth $ localRegType 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 (cmmExprType . hintlessCmm) args + final_arg_size (FinalJump _ args) = + argumentsSize (cmmExprType . hintlessCmm) args + final_arg_size (FinalCall _ _ _ _ _ _ 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 (cmmExprType . hintlessCmm) 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 (cmmExprType . hintlessCmm) args + stmt_arg_size (CmmCall _ _ _ (CmmSafe _) _) = + panic "Safe call in processFormats" + stmt_arg_size (CmmReturn _) = + panic "CmmReturn in processFormats" + stmt_arg_size _ = 0 + +----------------------------------------------------------------------------- +applyContinuationFormat :: [(CLabel, ContinuationFormat)] + -> Continuation (Either C_SRT CmmInfo) + -> Continuation CmmInfo + +-- User written continuations +applyContinuationFormat formats + (Continuation (Right (CmmInfo gc update_frame + (CmmInfoTable clos prof tag (ContInfo _ srt)))) + label formals is_gc blocks) = + Continuation (CmmInfo gc update_frame (CmmInfoTable clos prof tag (ContInfo format srt))) + label formals is_gc blocks + where + 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 _ (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 gc Nothing (CmmInfoTable undefined prof tag (ContInfo (continuation_stack $ format) srt))) + label formals is_gc blocks + where + 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" --------------------------------------------------------------------------------- -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. - -- continuationC <- return abstractC - -- TODO: find out if it is valid to create a new unique source like this - uniqSupply <- mkSplitUniqSupply 'p' - let (_, continuationC) = runCPS (mapM (mapMCmmTop cpsProc) abstractC) (CPSState uniqSupply) - - dumpIfSet_dyn dflags Opt_D_dump_cps_cmm "CPS Cmm" (pprCmms continuationC) - -- TODO: add option to dump Cmm to file - return continuationC